treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

59 files changed, 56685 insertions, 0 deletions

diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
new file mode 100644
index 000000000..ffb76761d
--- /dev/null
+++ b/fs/nfsd/Kconfig
@@ -0,0 +1,197 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NFSD
+	tristate "NFS server support"
+	depends on INET
+	depends on FILE_LOCKING
+	depends on FSNOTIFY
+	select CRC32
+	select CRYPTO_LIB_MD5 if NFSD_LEGACY_CLIENT_TRACKING
+	select CRYPTO_LIB_SHA256 if NFSD_V4
+	select CRYPTO # required by RPCSEC_GSS_KRB5 and signed filehandles
+	select LOCKD
+	select SUNRPC
+	select EXPORTFS
+	select NFS_COMMON
+	select NFS_ACL_SUPPORT if NFSD_V2_ACL
+	select NFS_ACL_SUPPORT if NFSD_V3_ACL
+	depends on MULTIUSER
+	help
+	  Choose Y here if you want to allow other computers to access
+	  files residing on this system using Sun's Network File System
+	  protocol.  To compile the NFS server support as a module,
+	  choose M here: the module will be called nfsd.
+
+	  You may choose to use a user-space NFS server instead, in which
+	  case you can choose N here.
+
+	  To export local file systems using NFS, you also need to install
+	  user space programs which can be found in the Linux nfs-utils
+	  package, available from http://linux-nfs.org/.  More detail about
+	  the Linux NFS server implementation is available via the
+	  exports(5) man page.
+
+	  Below you can choose which versions of the NFS protocol are
+	  available to clients mounting the NFS server on this system.
+	  Support for NFS version 3 (RFC 1813) is always available when
+	  CONFIG_NFSD is selected.
+
+	  If unsure, say N.
+
+config NFSD_V2
+	bool "NFS server support for NFS version 2 (DEPRECATED)"
+	depends on NFSD
+	default n
+	help
+	  NFSv2 (RFC 1094) was the first publicly-released version of NFS.
+	  Unless you are hosting ancient (1990's era) NFS clients, you don't
+	  need this.
+
+	  If unsure, say N.
+
+config NFSD_V2_ACL
+	bool "NFS server support for the NFSv2 ACL protocol extension"
+	depends on NFSD_V2
+
+config NFSD_V3_ACL
+	bool "NFS server support for the NFSv3 ACL protocol extension"
+	depends on NFSD
+	help
+	  Solaris NFS servers support an auxiliary NFSv3 ACL protocol that
+	  never became an official part of the NFS version 3 protocol.
+	  This protocol extension allows applications on NFS clients to
+	  manipulate POSIX Access Control Lists on files residing on NFS
+	  servers.  NFS servers enforce POSIX ACLs on local files whether
+	  this protocol is available or not.
+
+	  This option enables support in your system's NFS server for the
+	  NFSv3 ACL protocol extension allowing NFS clients to manipulate
+	  POSIX ACLs on files exported by your system's NFS server.  NFS
+	  clients which support the Solaris NFSv3 ACL protocol can then
+	  access and modify ACLs on your NFS server.
+
+	  To store ACLs on your NFS server, you also need to enable ACL-
+	  related CONFIG options for your local file systems of choice.
+
+	  If unsure, say N.
+
+config NFSD_V4
+	bool "NFS server support for NFS version 4"
+	depends on NFSD && PROC_FS
+	select FS_POSIX_ACL
+	select RPCSEC_GSS_KRB5
+	select GRACE_PERIOD
+	select NFS_V4_2_SSC_HELPER if NFS_V4_2
+	help
+	  This option enables support in your system's NFS server for
+	  version 4 of the NFS protocol (RFC 3530).
+
+	  To export files using NFSv4, you need to install additional user
+	  space programs which can be found in the Linux nfs-utils package,
+	  available from http://linux-nfs.org/.
+
+	  If unsure, say N.
+
+config NFSD_PNFS
+	bool
+
+config NFSD_BLOCKLAYOUT
+	bool "NFSv4.1 server support for pNFS block layouts"
+	depends on NFSD_V4 && BLOCK
+	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
+	help
+	  This option enables support for the exporting pNFS block layouts
+	  in the kernel's NFS server. The pNFS block layout enables NFS
+	  clients to directly perform I/O to block devices accessible to both
+	  the server and the clients.  See RFC 5663 for more details.
+
+	  If unsure, say N.
+
+config NFSD_SCSILAYOUT
+	bool "NFSv4.1 server support for pNFS SCSI layouts"
+	depends on NFSD_V4 && BLOCK
+	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
+	help
+	  This option enables support for the exporting pNFS SCSI layouts
+	  in the kernel's NFS server. The pNFS SCSI layout enables NFS
+	  clients to directly perform I/O to SCSI devices accessible to both
+	  the server and the clients.  See draft-ietf-nfsv4-scsi-layout for
+	  more details.
+
+	  If unsure, say N.
+
+config NFSD_FLEXFILELAYOUT
+	bool "NFSv4.1 server support for pNFS Flex File layouts"
+	depends on NFSD_V4
+	select NFSD_PNFS
+	help
+	  This option enables support for the exporting pNFS Flex File
+	  layouts in the kernel's NFS server. The pNFS Flex File  layout
+	  enables NFS clients to directly perform I/O to NFSv3 devices
+	  accessible to both the server and the clients.  See
+	  draft-ietf-nfsv4-flex-files for more details.
+
+	  Warning, this server implements the bare minimum functionality
+	  to be a flex file server - it is for testing the client,
+	  not for use in production.
+
+	  If unsure, say N.
+
+config NFSD_V4_2_INTER_SSC
+	bool "NFSv4.2 inter server to server COPY"
+	depends on NFSD_V4 && NFS_V4_2
+	help
+	  This option enables support for NFSv4.2 inter server to
+	  server copy where the destination server calls the NFSv4.2
+	  client to read the data to copy from the source server.
+
+	  If unsure, say N.
+
+config NFSD_V4_SECURITY_LABEL
+	bool "Provide Security Label support for NFSv4 server"
+	depends on NFSD_V4 && SECURITY
+	help
+
+	Say Y here if you want enable fine-grained security label attribute
+	support for NFS version 4.  Security labels allow security modules like
+	SELinux and Smack to label files to facilitate enforcement of their policies.
+	Without this an NFSv4 mount will have the same label on each file.
+
+	If you do not wish to enable fine-grained security labels SELinux or
+	Smack policies on NFSv4 files, say N.
+
+config NFSD_LEGACY_CLIENT_TRACKING
+	bool "Support legacy NFSv4 client tracking methods (DEPRECATED)"
+	depends on NFSD_V4
+	default n
+	help
+	  The NFSv4 server needs to store a small amount of information on
+	  stable storage in order to handle state recovery after reboot. Most
+	  modern deployments upcall to a userland daemon for this (nfsdcld),
+	  but older NFS servers may store information directly in a
+	  recoverydir, or spawn a process directly using a usermodehelper
+	  upcall.
+
+	  These legacy client tracking methods have proven to be problematic
+	  and will be removed in the future. Say Y here if you need support
+	  for them in the interim.
+
+config NFSD_V4_POSIX_ACLS
+	bool "Support NFSv4 POSIX draft ACLs"
+	depends on NFSD_V4
+	default n
+	help
+	  Include experimental support for POSIX Access Control Lists
+	  (ACLs) in NFSv4 as specified in the IETF draft
+	  draft-ietf-nfsv4-posix-acls. This protocol extension enables
+	  NFSv4 clients to retrieve and modify POSIX ACLs on exported
+	  filesystems that support them.
+
+	  This feature is based on an unratified IETF draft
+	  specification that may change in ways that impact
+	  interoperability with existing clients. Enable only for
+	  testing environments or when interoperability with specific
+	  clients that implement this draft is required.
+
+	  If unsure, say N.
diff --git a/fs/nfsd/Makefile b/fs/nfsd/Makefile
new file mode 100644
index 000000000..f0da4d69d
--- /dev/null
+++ b/fs/nfsd/Makefile
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux nfs server
+#
+
+ccflags-y += -I$(src)			# needed for trace events
+
+obj-$(CONFIG_NFSD)	+= nfsd.o
+
+# this one should be compiled first, as the tracing macros can easily blow up
+nfsd-y			+= trace.o
+
+nfsd-y 			+= nfssvc.o nfsctl.o nfsfh.o vfs.o \
+			   export.o auth.o lockd.o nfscache.o \
+			   stats.o filecache.o nfs3proc.o nfs3xdr.o \
+			   netlink.o
+nfsd-$(CONFIG_NFSD_V2) += nfsproc.o nfsxdr.o
+nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
+nfsd-$(CONFIG_NFSD_V3_ACL) += nfs3acl.o
+nfsd-$(CONFIG_NFSD_V4)	+= nfs4proc.o nfs4xdr.o nfs4state.o nfs4idmap.o \
+			   nfs4acl.o nfs4callback.o nfs4recover.o nfs4xdr_gen.o
+nfsd-$(CONFIG_NFSD_PNFS) += nfs4layouts.o
+nfsd-$(CONFIG_NFSD_BLOCKLAYOUT) += blocklayout.o blocklayoutxdr.o
+nfsd-$(CONFIG_NFSD_SCSILAYOUT) += blocklayout.o blocklayoutxdr.o
+nfsd-$(CONFIG_NFSD_FLEXFILELAYOUT) += flexfilelayout.o flexfilelayoutxdr.o
+nfsd-$(CONFIG_NFS_LOCALIO) += localio.o
+nfsd-$(CONFIG_DEBUG_FS) += debugfs.o
+
+#
+# XDR code generation (requires Python and additional packages)
+#
+# The generated *xdr_gen.{h,c} files are checked into git. Normal kernel
+# builds do not require the xdrgen tool or its Python dependencies.
+#
+# Developers modifying .x files in Documentation/sunrpc/xdr/ should run
+# "make xdrgen" to regenerate the affected files.
+#
+.PHONY: xdrgen
+
+xdrgen: ../../include/linux/sunrpc/xdrgen/nfs4_1.h nfs4xdr_gen.h nfs4xdr_gen.c
+
+../../include/linux/sunrpc/xdrgen/nfs4_1.h: ../../Documentation/sunrpc/xdr/nfs4_1.x
+	../../tools/net/sunrpc/xdrgen/xdrgen definitions $< > $@
+
+nfs4xdr_gen.h: ../../Documentation/sunrpc/xdr/nfs4_1.x
+	../../tools/net/sunrpc/xdrgen/xdrgen declarations $< > $@
+
+nfs4xdr_gen.c: ../../Documentation/sunrpc/xdr/nfs4_1.x
+	../../tools/net/sunrpc/xdrgen/xdrgen source $< > $@
diff --git a/fs/nfsd/acl.h b/fs/nfsd/acl.h
new file mode 100644
index 000000000..2003523d0
--- /dev/null
+++ b/fs/nfsd/acl.h
@@ -0,0 +1,54 @@
+/*
+ *  Common NFSv4 ACL handling definitions.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LINUX_NFS4_ACL_H
+#define LINUX_NFS4_ACL_H
+
+struct nfs4_acl;
+struct svc_fh;
+struct svc_rqst;
+struct nfsd_attrs;
+enum nfs_ftype4;
+
+int nfs4_acl_bytes(int entries);
+int nfs4_acl_get_whotype(char *, u32);
+__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who);
+
+int nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
+		struct nfs4_acl **acl);
+__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
+			 struct nfsd_attrs *attr);
+void sort_pacl_range(struct posix_acl *pacl, int start, int end);
+
+#endif /* LINUX_NFS4_ACL_H */
diff --git a/fs/nfsd/attr4.h b/fs/nfsd/attr4.h
new file mode 100644
index 000000000..f0b51f805
--- /dev/null
+++ b/fs/nfsd/attr4.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NFSv4 file attributes supported by this implementation
+ */
+
+#ifndef _LINUX_NFSD_ATTR4_H
+#define _LINUX_NFSD_ATTR4_H
+
+#include <linux/types.h>
+#include <linux/nfs4.h>
+
+/*
+ * The following attributes are not implemented by NFSD:
+ *    ARCHIVE       (deprecated anyway)
+ *    HIDDEN        (unlikely to be supported any time soon)
+ *    MIMETYPE      (unlikely to be supported any time soon)
+ *    QUOTA_*       (unlikely to be supported any time soon)
+ *    SYSTEM        (unlikely to be supported any time soon)
+ *    TIME_BACKUP   (unlikely to be supported any time soon)
+ */
+#define NFSD4_SUPPORTED_ATTRS_WORD0                                                         \
+(FATTR4_WORD0_SUPPORTED_ATTRS   | FATTR4_WORD0_TYPE         | FATTR4_WORD0_FH_EXPIRE_TYPE   \
+ | FATTR4_WORD0_CHANGE          | FATTR4_WORD0_SIZE         | FATTR4_WORD0_LINK_SUPPORT     \
+ | FATTR4_WORD0_SYMLINK_SUPPORT | FATTR4_WORD0_NAMED_ATTR   | FATTR4_WORD0_FSID             \
+ | FATTR4_WORD0_UNIQUE_HANDLES  | FATTR4_WORD0_LEASE_TIME   | FATTR4_WORD0_RDATTR_ERROR     \
+ | FATTR4_WORD0_ACLSUPPORT      | FATTR4_WORD0_CANSETTIME   | FATTR4_WORD0_CASE_INSENSITIVE \
+ | FATTR4_WORD0_CASE_PRESERVING | FATTR4_WORD0_CHOWN_RESTRICTED                             \
+ | FATTR4_WORD0_FILEHANDLE      | FATTR4_WORD0_FILEID       | FATTR4_WORD0_FILES_AVAIL      \
+ | FATTR4_WORD0_FILES_FREE      | FATTR4_WORD0_FILES_TOTAL  | FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_HOMOGENEOUS      \
+ | FATTR4_WORD0_MAXFILESIZE     | FATTR4_WORD0_MAXLINK      | FATTR4_WORD0_MAXNAME          \
+ | FATTR4_WORD0_MAXREAD         | FATTR4_WORD0_MAXWRITE     | FATTR4_WORD0_ACL)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD1                                                         \
+(FATTR4_WORD1_MODE              | FATTR4_WORD1_NO_TRUNC     | FATTR4_WORD1_NUMLINKS         \
+ | FATTR4_WORD1_OWNER	        | FATTR4_WORD1_OWNER_GROUP  | FATTR4_WORD1_RAWDEV           \
+ | FATTR4_WORD1_SPACE_AVAIL     | FATTR4_WORD1_SPACE_FREE   | FATTR4_WORD1_SPACE_TOTAL      \
+ | FATTR4_WORD1_SPACE_USED      | FATTR4_WORD1_TIME_ACCESS  | FATTR4_WORD1_TIME_ACCESS_SET  \
+ | FATTR4_WORD1_TIME_DELTA      | FATTR4_WORD1_TIME_METADATA   | FATTR4_WORD1_TIME_CREATE      \
+ | FATTR4_WORD1_TIME_MODIFY     | FATTR4_WORD1_TIME_MODIFY_SET | FATTR4_WORD1_MOUNTED_ON_FILEID)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD2 0
+
+/* 4.1 */
+#ifdef CONFIG_NFSD_PNFS
+#define PNFSD_SUPPORTED_ATTRS_WORD1	FATTR4_WORD1_FS_LAYOUT_TYPES
+#define PNFSD_SUPPORTED_ATTRS_WORD2 \
+(FATTR4_WORD2_LAYOUT_BLKSIZE	| FATTR4_WORD2_LAYOUT_TYPES)
+#else
+#define PNFSD_SUPPORTED_ATTRS_WORD1	0
+#define PNFSD_SUPPORTED_ATTRS_WORD2	0
+#endif /* CONFIG_NFSD_PNFS */
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD0 \
+	NFSD4_SUPPORTED_ATTRS_WORD0
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD1 \
+	(NFSD4_SUPPORTED_ATTRS_WORD1	| PNFSD_SUPPORTED_ATTRS_WORD1)
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_SUPPORTED_ATTRS_WORD2	| PNFSD_SUPPORTED_ATTRS_WORD2 | \
+	 FATTR4_WORD2_SUPPATTR_EXCLCREAT)
+
+/* 4.2 */
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define NFSD4_2_SECURITY_ATTRS		FATTR4_WORD2_SECURITY_LABEL
+#else
+#define NFSD4_2_SECURITY_ATTRS		0
+#endif
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+#define NFSD4_2_POSIX_ACL_ATTRS \
+	(FATTR4_WORD2_ACL_TRUEFORM | \
+	FATTR4_WORD2_ACL_TRUEFORM_SCOPE | \
+	FATTR4_WORD2_POSIX_DEFAULT_ACL | \
+	FATTR4_WORD2_POSIX_ACCESS_ACL)
+#else
+#define NFSD4_2_POSIX_ACL_ATTRS		0
+#endif
+
+#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+	FATTR4_WORD2_MODE_UMASK | \
+	FATTR4_WORD2_CLONE_BLKSIZE | \
+	NFSD4_2_SECURITY_ATTRS | \
+	FATTR4_WORD2_XATTR_SUPPORT | \
+	FATTR4_WORD2_TIME_DELEG_ACCESS | \
+	FATTR4_WORD2_TIME_DELEG_MODIFY | \
+	FATTR4_WORD2_OPEN_ARGUMENTS | \
+	NFSD4_2_POSIX_ACL_ATTRS)
+
+/* These will return ERR_INVAL if specified in GETATTR or READDIR. */
+#define NFSD_WRITEONLY_ATTRS_WORD1 \
+	(FATTR4_WORD1_TIME_ACCESS_SET   | FATTR4_WORD1_TIME_MODIFY_SET)
+
+/*
+ * These are the only attrs allowed in CREATE/OPEN/SETATTR. Don't add
+ * a writeable attribute here without also adding code to parse it to
+ * nfsd4_decode_fattr4().
+ */
+#define NFSD_WRITEABLE_ATTRS_WORD0 \
+	(FATTR4_WORD0_SIZE | FATTR4_WORD0_ACL)
+#define NFSD_WRITEABLE_ATTRS_WORD1 \
+	(FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \
+	| FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_CREATE \
+	| FATTR4_WORD1_TIME_MODIFY_SET)
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+	FATTR4_WORD2_SECURITY_LABEL
+#else
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL 0
+#endif
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+#define MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS \
+	FATTR4_WORD2_POSIX_DEFAULT_ACL | FATTR4_WORD2_POSIX_ACCESS_ACL
+#else
+#define MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS 0
+#endif
+#define NFSD_WRITEABLE_ATTRS_WORD2 \
+	(FATTR4_WORD2_MODE_UMASK \
+	| MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+	| FATTR4_WORD2_TIME_DELEG_ACCESS \
+	| FATTR4_WORD2_TIME_DELEG_MODIFY \
+	| MAYBE_FATTR4_WORD2_POSIX_ACL_ATTRS \
+	)
+
+#define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
+	NFSD_WRITEABLE_ATTRS_WORD0
+/*
+ * we currently store the exclusive create verifier in the v_{a,m}time
+ * attributes so the client can't set these at create time using EXCLUSIVE4_1
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD1 \
+	(NFSD_WRITEABLE_ATTRS_WORD1 & \
+	 ~(FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET))
+/*
+ * The FATTR4_WORD2_TIME_DELEG attributes are not to be allowed for
+ * OPEN(create) with EXCLUSIVE4_1. It doesn't make sense to set a
+ * delegated timestamp on a new file.
+ *
+ * This mask includes NFSv4.2-only attributes (e.g., POSIX ACLs).
+ * Version filtering occurs via nfsd_suppattrs[] before this mask
+ * is applied, so pre-4.2 clients never see unsupported attributes.
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD2 \
+	(NFSD_WRITEABLE_ATTRS_WORD2 & \
+	~(FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY))
+
+extern const u32 nfsd_suppattrs[3][3];
+
+static inline bool bmval_is_subset(const u32 *bm1, const u32 *bm2)
+{
+	return !((bm1[0] & ~bm2[0]) ||
+	         (bm1[1] & ~bm2[1]) ||
+		 (bm1[2] & ~bm2[2]));
+}
+
+static inline bool nfsd_attrs_supported(u32 minorversion, const u32 *bmval)
+{
+	return bmval_is_subset(bmval, nfsd_suppattrs[minorversion]);
+}
+
+#endif /* _LINUX_NFSD_ATTR4_H */
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
new file mode 100644
index 000000000..5ef9a0466
--- /dev/null
+++ b/fs/nfsd/auth.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
+
+#include <linux/sched.h>
+#include "nfsd.h"
+#include "export.h"
+#include "auth.h"
+
+int nfsexp_flags(struct svc_cred *cred, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+
+	for (f = exp->ex_flavors; f < end; f++) {
+		if (f->pseudoflavor == cred->cr_flavor)
+			return f->flags;
+	}
+	return exp->ex_flags;
+
+}
+
+int nfsd_setuser(struct svc_cred *cred, struct svc_export *exp)
+{
+	struct group_info *rqgi;
+	struct group_info *gi;
+	struct cred *new;
+	int i;
+	int flags = nfsexp_flags(cred, exp);
+
+	/* discard any old override before preparing the new set */
+	put_cred(revert_creds(get_cred(current_real_cred())));
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	new->fsuid = cred->cr_uid;
+	new->fsgid = cred->cr_gid;
+
+	rqgi = cred->cr_group_info;
+
+	if (flags & NFSEXP_ALLSQUASH) {
+		new->fsuid = exp->ex_anon_uid;
+		new->fsgid = exp->ex_anon_gid;
+		gi = groups_alloc(0);
+		if (!gi)
+			goto oom;
+	} else if (flags & NFSEXP_ROOTSQUASH) {
+		if (uid_eq(new->fsuid, GLOBAL_ROOT_UID))
+			new->fsuid = exp->ex_anon_uid;
+		if (gid_eq(new->fsgid, GLOBAL_ROOT_GID))
+			new->fsgid = exp->ex_anon_gid;
+
+		gi = groups_alloc(rqgi->ngroups);
+		if (!gi)
+			goto oom;
+
+		for (i = 0; i < rqgi->ngroups; i++) {
+			if (gid_eq(GLOBAL_ROOT_GID, rqgi->gid[i]))
+				gi->gid[i] = exp->ex_anon_gid;
+			else
+				gi->gid[i] = rqgi->gid[i];
+		}
+
+		/* Each thread allocates its own gi, no race */
+		groups_sort(gi);
+	} else {
+		gi = get_group_info(rqgi);
+	}
+
+	if (uid_eq(new->fsuid, INVALID_UID))
+		new->fsuid = exp->ex_anon_uid;
+	if (gid_eq(new->fsgid, INVALID_GID))
+		new->fsgid = exp->ex_anon_gid;
+
+	set_groups(new, gi);
+	put_group_info(gi);
+
+	if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
+		new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
+	else
+		new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
+							new->cap_permitted);
+	put_cred(override_creds(new));
+	return 0;
+
+oom:
+	abort_creds(new);
+	return -ENOMEM;
+}
+
+/**
+ * nfsd_user_namespace - Get user_namespace in effect for an RPC request
+ * @rqstp: RPC execution context
+ *
+ * xpt_cred is set once at transport creation and never modified. The
+ * transport itself is reference-counted during request processing, so
+ * no explicit reference on the namespace is necessary.
+ *
+ * Return: the user_namespace from the transport credential, or
+ * init_user_ns if no credential was set. The returned namespace pointer
+ * is valid for the duration of the RPC request.
+ */
+struct user_namespace *nfsd_user_namespace(const struct svc_rqst *rqstp)
+{
+	const struct cred *cred = rqstp->rq_xprt->xpt_cred;
+
+	return cred ? cred->user_ns : &init_user_ns;
+}
diff --git a/fs/nfsd/auth.h b/fs/nfsd/auth.h
new file mode 100644
index 000000000..832bc9579
--- /dev/null
+++ b/fs/nfsd/auth.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * nfsd-specific authentication stuff.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_AUTH_H
+#define LINUX_NFSD_AUTH_H
+
+struct user_namespace;
+struct svc_export;
+struct svc_rqst;
+
+/*
+ * Set the current process's fsuid/fsgid etc to those of the NFS
+ * client user
+ */
+int nfsd_setuser(struct svc_cred *cred, struct svc_export *exp);
+
+struct user_namespace *nfsd_user_namespace(const struct svc_rqst *rqstp);
+
+#endif /* LINUX_NFSD_AUTH_H */
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
new file mode 100644
index 000000000..5be7721c2
--- /dev/null
+++ b/fs/nfsd/blocklayout.c
@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+#include <linux/exportfs_block.h>
+#include <linux/iomap.h>
+#include <linux/slab.h>
+#include <linux/pr.h>
+
+#include <linux/nfsd/debug.h>
+
+#include "blocklayoutxdr.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "vfs.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+
+/*
+ * Get an extent from the file system that starts at offset or below
+ * and may be shorter than the requested length.
+ */
+static __be32
+nfsd4_block_map_extent(struct inode *inode, const struct svc_fh *fhp,
+		u64 offset, u64 length, u32 iomode, u64 minlength,
+		struct pnfs_block_extent *bex)
+{
+	struct super_block *sb = inode->i_sb;
+	struct iomap iomap;
+	u32 device_generation = 0;
+	int error;
+
+	error = sb->s_export_op->block_ops->map_blocks(inode, offset, length,
+			&iomap, iomode != IOMODE_READ, &device_generation);
+	if (error) {
+		if (error == -ENXIO)
+			return nfserr_layoutunavailable;
+		return nfserrno(error);
+	}
+
+	switch (iomap.type) {
+	case IOMAP_MAPPED:
+		if (iomode == IOMODE_READ)
+			bex->es = PNFS_BLOCK_READ_DATA;
+		else
+			bex->es = PNFS_BLOCK_READWRITE_DATA;
+		bex->soff = iomap.addr;
+		break;
+	case IOMAP_UNWRITTEN:
+		if (iomode & IOMODE_RW) {
+			/*
+			 * Crack monkey special case from section 2.3.1.
+			 */
+			if (minlength == 0) {
+				dprintk("pnfsd: no soup for you!\n");
+				return nfserr_layoutunavailable;
+			}
+
+			bex->es = PNFS_BLOCK_INVALID_DATA;
+			bex->soff = iomap.addr;
+			break;
+		}
+		fallthrough;
+	case IOMAP_HOLE:
+		if (iomode == IOMODE_READ) {
+			bex->es = PNFS_BLOCK_NONE_DATA;
+			break;
+		}
+		fallthrough;
+	case IOMAP_DELALLOC:
+	default:
+		WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
+		return nfserr_layoutunavailable;
+	}
+
+	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
+	if (error)
+		return nfserrno(error);
+
+	bex->foff = iomap.offset;
+	bex->len = iomap.length;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_block_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode,
+		const struct svc_fh *fhp, struct nfsd4_layoutget *args)
+{
+	struct nfsd4_layout_seg *seg = &args->lg_seg;
+	struct pnfs_block_layout *bl;
+	struct pnfs_block_extent *first_bex, *last_bex;
+	u64 offset = seg->offset, length = seg->length;
+	u32 i, nr_extents_max, block_size = i_blocksize(inode);
+	__be32 nfserr;
+
+	if (locks_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	nfserr = nfserr_layoutunavailable;
+	if (seg->offset & (block_size - 1)) {
+		dprintk("pnfsd: I/O misaligned\n");
+		goto out_error;
+	}
+
+	/*
+	 * RFC 8881, section 3.3.17:
+	 *   The layout4 data type defines a layout for a file.
+	 *
+	 * RFC 8881, section 18.43.3:
+	 *   The loga_maxcount field specifies the maximum layout size
+	 *   (in bytes) that the client can handle. If the size of the
+	 *   layout structure exceeds the size specified by maxcount,
+	 *   the metadata server will return the NFS4ERR_TOOSMALL error.
+	 */
+	nfserr = nfserr_toosmall;
+	if (args->lg_maxcount < PNFS_BLOCK_LAYOUT4_SIZE +
+				PNFS_BLOCK_EXTENT_SIZE)
+		goto out_error;
+
+	/*
+	 * Limit the maximum layout size to avoid allocating
+	 * a large buffer on the server for each layout request.
+	 */
+	nr_extents_max = (min(args->lg_maxcount, PAGE_SIZE) -
+			  PNFS_BLOCK_LAYOUT4_SIZE) / PNFS_BLOCK_EXTENT_SIZE;
+
+	/*
+	 * Some clients barf on non-zero block numbers for NONE or INVALID
+	 * layouts, so make sure to zero the whole structure.
+	 */
+	nfserr = nfserrno(-ENOMEM);
+	bl = kzalloc_flex(*bl, extents, nr_extents_max);
+	if (!bl)
+		goto out_error;
+	bl->nr_extents = nr_extents_max;
+	args->lg_content = bl;
+
+	for (i = 0; i < bl->nr_extents; i++) {
+		struct pnfs_block_extent *bex = bl->extents + i;
+		u64 bex_length;
+
+		nfserr = nfsd4_block_map_extent(inode, fhp, offset, length,
+				seg->iomode, args->lg_minlength, bex);
+		if (nfserr != nfs_ok)
+			goto out_error;
+
+		bex_length = bex->len - (offset - bex->foff);
+		if (bex_length >= length) {
+			bl->nr_extents = i + 1;
+			break;
+		}
+
+		offset = bex->foff + bex->len;
+		length -= bex_length;
+	}
+
+	first_bex = bl->extents;
+	last_bex = bl->extents + bl->nr_extents - 1;
+
+	nfserr = nfserr_layoutunavailable;
+	length = last_bex->foff + last_bex->len - seg->offset;
+	if (length < args->lg_minlength) {
+		dprintk("pnfsd: extent smaller than minlength\n");
+		goto out_error;
+	}
+
+	seg->offset = first_bex->foff;
+	seg->length = last_bex->foff - first_bex->foff + last_bex->len;
+	return nfs_ok;
+
+out_error:
+	seg->length = 0;
+	return nfserr;
+}
+
+static __be32
+nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
+		struct iomap *iomaps, int nr_iomaps)
+{
+	int error;
+
+	/*
+	 * This ignores the client provided mtime in loca_time_modify, as a
+	 * fully client specified mtime doesn't really fit into the Linux
+	 * multi-grain timestamp architecture.
+	 *
+	 * RFC 8881 Section 18.42 makes it clear that the client provided
+	 * timestamp is a "may" condition, and clients that want to force a
+	 * specific timestamp should send a separate SETATTR in the compound.
+	 */
+	error = inode->i_sb->s_export_op->block_ops->commit_blocks(inode,
+			iomaps, nr_iomaps,
+			lcp->lc_size_chg ? lcp->lc_newsize : 0);
+	kfree(iomaps);
+	return nfserrno(error);
+}
+
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+static int
+nfsd4_block_get_device_info_simple(struct super_block *sb,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev;
+	struct pnfs_block_volume *b;
+
+	dev = kzalloc_flex(*dev, volumes, 1);
+	if (!dev)
+		return -ENOMEM;
+	gdp->gd_device = dev;
+
+	dev->nr_volumes = 1;
+	b = &dev->volumes[0];
+
+	b->type = PNFS_BLOCK_VOLUME_SIMPLE;
+	b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
+	return sb->s_export_op->block_ops->get_uuid(sb, b->simple.sig,
+			&b->simple.sig_len, &b->simple.offset);
+}
+
+static __be32
+nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
+		struct svc_rqst *rqstp,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	if (bdev_is_partition(sb->s_bdev))
+		return nfserr_inval;
+	return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
+}
+
+static __be32
+nfsd4_block_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp,
+		struct nfsd4_layoutcommit *lcp)
+{
+	struct iomap *iomaps;
+	int nr_iomaps;
+	__be32 nfserr;
+
+	rqstp->rq_arg = lcp->lc_up_layout;
+	svcxdr_init_decode(rqstp);
+
+	nfserr = nfsd4_block_decode_layoutupdate(&rqstp->rq_arg_stream,
+			&iomaps, &nr_iomaps, i_blocksize(inode));
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
+}
+
+const struct nfsd4_layout_ops bl_layout_ops = {
+	/*
+	 * Pretend that we send notification to the client.  This is a blatant
+	 * lie to force recent Linux clients to cache our device IDs.
+	 * We rarely ever change the device ID, so the harm of leaking deviceids
+	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
+	 * in this regard, but I filed errata 4119 for this a while ago, and
+	 * hopefully the Linux client will eventually start caching deviceids
+	 * without this again.
+	 */
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.proc_getdeviceinfo	= nfsd4_block_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_block_proc_layoutget,
+	.encode_layoutget	= nfsd4_block_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_block_proc_layoutcommit,
+};
+#endif /* CONFIG_NFSD_BLOCKLAYOUT */
+
+#ifdef CONFIG_NFSD_SCSILAYOUT
+
+#define NFSD_MDS_PR_FENCED	XA_MARK_0
+
+/*
+ * Clear the fence flag if the device already has an entry. This occurs
+ * when a client re-registers after a previous fence, allowing new
+ * layouts for this device.
+ *
+ * Insert only on first registration. This bounds cl_dev_fences to the
+ * count of devices this client has accessed, preventing unbounded growth.
+ */
+static inline int nfsd4_scsi_fence_insert(struct nfs4_client *clp,
+					  dev_t device)
+{
+	struct xarray *xa = &clp->cl_dev_fences;
+	int ret;
+
+	xa_lock(xa);
+	ret = __xa_insert(xa, device, XA_ZERO_ENTRY, GFP_KERNEL);
+	if (ret == -EBUSY) {
+		__xa_clear_mark(xa, device, NFSD_MDS_PR_FENCED);
+		ret = 0;
+	}
+	xa_unlock(xa);
+	clp->cl_fence_retry_warn = false;
+	return ret;
+}
+
+static inline bool nfsd4_scsi_fence_set(struct nfs4_client *clp, dev_t device)
+{
+	struct xarray *xa = &clp->cl_dev_fences;
+	bool skip;
+
+	xa_lock(xa);
+	skip = xa_get_mark(xa, device, NFSD_MDS_PR_FENCED);
+	if (!skip)
+		__xa_set_mark(xa, device, NFSD_MDS_PR_FENCED);
+	xa_unlock(xa);
+	return skip;
+}
+
+static inline void nfsd4_scsi_fence_clear(struct nfs4_client *clp, dev_t device)
+{
+	xa_clear_mark(&clp->cl_dev_fences, device, NFSD_MDS_PR_FENCED);
+}
+
+#define NFSD_MDS_PR_KEY		0x0100000000000000ULL
+
+/*
+ * We use the client ID as a unique key for the reservations.
+ * This allows us to easily fence a client when recalls fail.
+ */
+static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
+{
+	return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id;
+}
+
+static const u8 designator_types[] = {
+	PS_DESIGNATOR_EUI64,
+	PS_DESIGNATOR_NAA,
+};
+
+static int
+nfsd4_block_get_unique_id(struct gendisk *disk, struct pnfs_block_volume *b)
+{
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(designator_types); i++) {
+		u8 type = designator_types[i];
+
+		ret = disk->fops->get_unique_id(disk, b->scsi.designator, type);
+		if (ret > 0) {
+			b->scsi.code_set = PS_CODE_SET_BINARY;
+			b->scsi.designator_type = type;
+			b->scsi.designator_len = ret;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int
+nfsd4_block_get_device_info_scsi(struct super_block *sb,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev;
+	struct pnfs_block_volume *b;
+	const struct pr_ops *ops;
+	int ret;
+
+	dev = kzalloc_flex(*dev, volumes, 1);
+	if (!dev)
+		return -ENOMEM;
+	gdp->gd_device = dev;
+
+	dev->nr_volumes = 1;
+	b = &dev->volumes[0];
+
+	b->type = PNFS_BLOCK_VOLUME_SCSI;
+	b->scsi.pr_key = nfsd4_scsi_pr_key(clp);
+
+	ret = nfsd4_block_get_unique_id(sb->s_bdev->bd_disk, b);
+	if (ret < 0)
+		goto out_free_dev;
+
+	ret = -EINVAL;
+	ops = sb->s_bdev->bd_disk->fops->pr_ops;
+	if (!ops) {
+		pr_err("pNFS: device %s does not support PRs.\n",
+			sb->s_id);
+		goto out_free_dev;
+	}
+
+	ret = nfsd4_scsi_fence_insert(clp, sb->s_bdev->bd_dev);
+	if (ret < 0)
+		goto out_free_dev;
+
+	ret = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
+	if (ret) {
+		pr_err("pNFS: failed to register key for device %s.\n",
+			sb->s_id);
+		goto out_free_dev;
+	}
+
+	ret = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
+			PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
+	if (ret) {
+		pr_err("pNFS: failed to reserve device %s.\n",
+			sb->s_id);
+		goto out_free_dev;
+	}
+
+	return 0;
+
+out_free_dev:
+	kfree(dev);
+	gdp->gd_device = NULL;
+	return ret;
+}
+
+static __be32
+nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
+		struct svc_rqst *rqstp,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	if (bdev_is_partition(sb->s_bdev))
+		return nfserr_inval;
+	return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
+}
+static __be32
+nfsd4_scsi_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp,
+		struct nfsd4_layoutcommit *lcp)
+{
+	struct iomap *iomaps;
+	int nr_iomaps;
+	__be32 nfserr;
+
+	rqstp->rq_arg = lcp->lc_up_layout;
+	svcxdr_init_decode(rqstp);
+
+	nfserr = nfsd4_scsi_decode_layoutupdate(&rqstp->rq_arg_stream,
+			&iomaps, &nr_iomaps, i_blocksize(inode));
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
+}
+
+/*
+ * Perform the fence operation to prevent the client from accessing the
+ * block device. If a fence operation is already in progress, wait for
+ * it to complete before checking the NFSD_MDS_PR_FENCED flag. Once the
+ * operation is complete, check the flag. If NFSD_MDS_PR_FENCED is set,
+ * update the layout stateid by setting the ls_fenced flag to indicate
+ * that the client has been fenced.
+ *
+ * The cl_fence_mutex ensures that the fence operation has been fully
+ * completed, rather than just in progress, when returning from this
+ * function.
+ *
+ * Return true if client was fenced otherwise return false.
+ */
+static bool
+nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls, struct nfsd_file *file)
+{
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	struct block_device *bdev = file->nf_file->f_path.mnt->mnt_sb->s_bdev;
+	int status;
+	bool ret;
+
+	mutex_lock(&clp->cl_fence_mutex);
+	if (nfsd4_scsi_fence_set(clp, bdev->bd_dev)) {
+		mutex_unlock(&clp->cl_fence_mutex);
+		return true;
+	}
+
+	status = bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
+			nfsd4_scsi_pr_key(clp),
+			PR_EXCLUSIVE_ACCESS_REG_ONLY, true);
+	/*
+	 * Reset to allow retry only when the command could not have
+	 * reached the device. Negative status means a local error
+	 * (e.g., -ENOMEM) prevented the command from being sent.
+	 * PR_STS_PATH_FAILED, PR_STS_PATH_FAST_FAILED, and
+	 * PR_STS_RETRY_PATH_FAILURE indicate transport path failures
+	 * before device delivery.
+	 *
+	 * For all other errors, the command may have reached the device
+	 * and the preempt may have succeeded. Avoid resetting, since
+	 * retrying a successful preempt returns PR_STS_IOERR or
+	 * PR_STS_RESERVATION_CONFLICT, which would cause an infinite
+	 * retry loop.
+	 */
+	switch (status) {
+	case 0:
+	case PR_STS_IOERR:
+	case PR_STS_RESERVATION_CONFLICT:
+		ret = true;
+		break;
+	default:
+		/* retry-able and other errors */
+		ret = false;
+		nfsd4_scsi_fence_clear(clp, bdev->bd_dev);
+		break;
+	}
+	mutex_unlock(&clp->cl_fence_mutex);
+
+	trace_nfsd_pnfs_fence(clp, bdev->bd_disk->disk_name, status);
+	return ret;
+}
+
+const struct nfsd4_layout_ops scsi_layout_ops = {
+	/*
+	 * Pretend that we send notification to the client.  This is a blatant
+	 * lie to force recent Linux clients to cache our device IDs.
+	 * We rarely ever change the device ID, so the harm of leaking deviceids
+	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
+	 * in this regard, but I filed errata 4119 for this a while ago, and
+	 * hopefully the Linux client will eventually start caching deviceids
+	 * without this again.
+	 */
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.proc_getdeviceinfo	= nfsd4_scsi_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_block_proc_layoutget,
+	.encode_layoutget	= nfsd4_block_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_scsi_proc_layoutcommit,
+	.fence_client		= nfsd4_scsi_fence_client,
+};
+#endif /* CONFIG_NFSD_SCSILAYOUT */
diff --git a/fs/nfsd/blocklayoutxdr.c b/fs/nfsd/blocklayoutxdr.c
new file mode 100644
index 000000000..f80dbc41f
--- /dev/null
+++ b/fs/nfsd/blocklayoutxdr.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+#include <linux/sunrpc/svc.h>
+#include <linux/exportfs.h>
+#include <linux/iomap.h>
+#include <linux/nfs4.h>
+
+#include "nfsd.h"
+#include "blocklayoutxdr.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+
+/**
+ * nfsd4_block_encode_layoutget - encode block/scsi layout extent array
+ * @xdr: stream for data encoding
+ * @lgp: layoutget content, actually an array of extents to encode
+ *
+ * Encode the opaque loc_body field in the layoutget response. Since the
+ * pnfs_block_layout4 and pnfs_scsi_layout4 structures on the wire are
+ * the same, this function is used by both layout drivers.
+ *
+ * Return values:
+ *   %nfs_ok: Success, all extents encoded into @xdr
+ *   %nfserr_toosmall: Not enough space in @xdr to encode all the data
+ */
+__be32
+nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
+		const struct nfsd4_layoutget *lgp)
+{
+	const struct pnfs_block_layout *bl = lgp->lg_content;
+	u32 i, len = sizeof(__be32) + bl->nr_extents * PNFS_BLOCK_EXTENT_SIZE;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
+	if (!p)
+		return nfserr_toosmall;
+
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(bl->nr_extents);
+
+	for (i = 0; i < bl->nr_extents; i++) {
+		const struct pnfs_block_extent *bex = bl->extents + i;
+
+		p = svcxdr_encode_deviceid4(p, &bex->vol_id);
+		p = xdr_encode_hyper(p, bex->foff);
+		p = xdr_encode_hyper(p, bex->len);
+		p = xdr_encode_hyper(p, bex->soff);
+		*p++ = cpu_to_be32(bex->es);
+	}
+
+	return nfs_ok;
+}
+
+static int
+nfsd4_block_encode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
+{
+	__be32 *p;
+	int len;
+
+	switch (b->type) {
+	case PNFS_BLOCK_VOLUME_SIMPLE:
+		len = 4 + 4 + 8 + 4 + (XDR_QUADLEN(b->simple.sig_len) << 2);
+		p = xdr_reserve_space(xdr, len);
+		if (!p)
+			return -ETOOSMALL;
+
+		*p++ = cpu_to_be32(b->type);
+		*p++ = cpu_to_be32(1);	/* single signature */
+		p = xdr_encode_hyper(p, b->simple.offset);
+		p = xdr_encode_opaque(p, b->simple.sig, b->simple.sig_len);
+		break;
+	case PNFS_BLOCK_VOLUME_SCSI:
+		len = 4 + 4 + 4 + 4 + (XDR_QUADLEN(b->scsi.designator_len) << 2) + 8;
+		p = xdr_reserve_space(xdr, len);
+		if (!p)
+			return -ETOOSMALL;
+
+		*p++ = cpu_to_be32(b->type);
+		*p++ = cpu_to_be32(b->scsi.code_set);
+		*p++ = cpu_to_be32(b->scsi.designator_type);
+		p = xdr_encode_opaque(p, b->scsi.designator, b->scsi.designator_len);
+		p = xdr_encode_hyper(p, b->scsi.pr_key);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return len;
+}
+
+__be32
+nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
+		const struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev = gdp->gd_device;
+	int len = sizeof(__be32), ret, i;
+	__be32 *p;
+
+	/*
+	 * See paragraph 5 of RFC 8881 S18.40.3.
+	 */
+	if (!gdp->gd_maxcount) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+
+	p = xdr_reserve_space(xdr, len + sizeof(__be32));
+	if (!p)
+		return nfserr_resource;
+
+	for (i = 0; i < dev->nr_volumes; i++) {
+		ret = nfsd4_block_encode_volume(xdr, &dev->volumes[i]);
+		if (ret < 0)
+			return nfserrno(ret);
+		len += ret;
+	}
+
+	/*
+	 * Fill in the overall length and number of volumes at the beginning
+	 * of the layout.
+	 */
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(dev->nr_volumes);
+	return 0;
+}
+
+/**
+ * nfsd4_block_decode_layoutupdate - decode the block layout extent array
+ * @xdr: subbuf set to the encoded array
+ * @iomapp: pointer to store the decoded extent array
+ * @nr_iomapsp: pointer to store the number of extents
+ * @block_size: alignment of extent offset and length
+ *
+ * This function decodes the opaque field of the layoutupdate4 structure
+ * in a layoutcommit request for the block layout driver. The field is
+ * actually an array of extents sent by the client. It also checks that
+ * the file offset, storage offset and length of each extent are aligned
+ * by @block_size.
+ *
+ * Return values:
+ *   %nfs_ok: Successful decoding, @iomapp and @nr_iomapsp are valid
+ *   %nfserr_bad_xdr: The encoded array in @xdr is invalid
+ *   %nfserr_inval: An unaligned extent found
+ *   %nfserr_delay: Failed to allocate memory for @iomapp
+ */
+__be32
+nfsd4_block_decode_layoutupdate(struct xdr_stream *xdr, struct iomap **iomapp,
+		int *nr_iomapsp, u32 block_size)
+{
+	struct iomap *iomaps;
+	u32 nr_iomaps, expected, len, i;
+	__be32 nfserr;
+
+	if (xdr_stream_decode_u32(xdr, &nr_iomaps))
+		return nfserr_bad_xdr;
+
+	len = sizeof(__be32) + xdr_stream_remaining(xdr);
+	expected = sizeof(__be32) + nr_iomaps * PNFS_BLOCK_EXTENT_SIZE;
+	if (len != expected)
+		return nfserr_bad_xdr;
+
+	iomaps = kzalloc_objs(*iomaps, nr_iomaps);
+	if (!iomaps)
+		return nfserr_delay;
+
+	for (i = 0; i < nr_iomaps; i++) {
+		struct pnfs_block_extent bex;
+
+		if (nfsd4_decode_deviceid4(xdr, &bex.vol_id)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+
+		if (xdr_stream_decode_u64(xdr, &bex.foff)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (bex.foff & (block_size - 1)) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+
+		if (xdr_stream_decode_u64(xdr, &bex.len)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (bex.len & (block_size - 1)) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+
+		if (xdr_stream_decode_u64(xdr, &bex.soff)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (bex.soff & (block_size - 1)) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+
+		if (xdr_stream_decode_u32(xdr, &bex.es)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (bex.es != PNFS_BLOCK_READWRITE_DATA) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+
+		iomaps[i].offset = bex.foff;
+		iomaps[i].length = bex.len;
+	}
+
+	*iomapp = iomaps;
+	*nr_iomapsp = nr_iomaps;
+	return nfs_ok;
+fail:
+	kfree(iomaps);
+	return nfserr;
+}
+
+/**
+ * nfsd4_scsi_decode_layoutupdate - decode the scsi layout extent array
+ * @xdr: subbuf set to the encoded array
+ * @iomapp: pointer to store the decoded extent array
+ * @nr_iomapsp: pointer to store the number of extents
+ * @block_size: alignment of extent offset and length
+ *
+ * This function decodes the opaque field of the layoutupdate4 structure
+ * in a layoutcommit request for the scsi layout driver. The field is
+ * actually an array of extents sent by the client. It also checks that
+ * the offset and length of each extent are aligned by @block_size.
+ *
+ * Return values:
+ *   %nfs_ok: Successful decoding, @iomapp and @nr_iomapsp are valid
+ *   %nfserr_bad_xdr: The encoded array in @xdr is invalid
+ *   %nfserr_inval: An unaligned extent found
+ *   %nfserr_delay: Failed to allocate memory for @iomapp
+ */
+__be32
+nfsd4_scsi_decode_layoutupdate(struct xdr_stream *xdr, struct iomap **iomapp,
+		int *nr_iomapsp, u32 block_size)
+{
+	struct iomap *iomaps;
+	u32 nr_iomaps, expected, len, i;
+	__be32 nfserr;
+
+	if (xdr_stream_decode_u32(xdr, &nr_iomaps))
+		return nfserr_bad_xdr;
+
+	len = sizeof(__be32) + xdr_stream_remaining(xdr);
+	expected = sizeof(__be32) + nr_iomaps * PNFS_SCSI_RANGE_SIZE;
+	if (len != expected)
+		return nfserr_bad_xdr;
+
+	iomaps = kzalloc_objs(*iomaps, nr_iomaps);
+	if (!iomaps)
+		return nfserr_delay;
+
+	for (i = 0; i < nr_iomaps; i++) {
+		u64 val;
+
+		if (xdr_stream_decode_u64(xdr, &val)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (val & (block_size - 1)) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+		iomaps[i].offset = val;
+
+		if (xdr_stream_decode_u64(xdr, &val)) {
+			nfserr = nfserr_bad_xdr;
+			goto fail;
+		}
+		if (val & (block_size - 1)) {
+			nfserr = nfserr_inval;
+			goto fail;
+		}
+		iomaps[i].length = val;
+	}
+
+	*iomapp = iomaps;
+	*nr_iomapsp = nr_iomaps;
+	return nfs_ok;
+fail:
+	kfree(iomaps);
+	return nfserr;
+}
diff --git a/fs/nfsd/blocklayoutxdr.h b/fs/nfsd/blocklayoutxdr.h
new file mode 100644
index 000000000..2e0c6c7d2
--- /dev/null
+++ b/fs/nfsd/blocklayoutxdr.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NFSD_BLOCKLAYOUTXDR_H
+#define _NFSD_BLOCKLAYOUTXDR_H 1
+
+#include <linux/blkdev.h>
+#include "xdr4.h"
+
+struct iomap;
+struct xdr_stream;
+
+/* On the wire size of the layout4 struct with zero number of extents */
+#define PNFS_BLOCK_LAYOUT4_SIZE \
+	(sizeof(__be32) * 2 +	/* offset4 */ \
+	 sizeof(__be32) * 2 +	/* length4 */ \
+	 sizeof(__be32) +	/* layoutiomode4 */ \
+	 sizeof(__be32) +	/* layouttype4 */ \
+	 sizeof(__be32) +	/* number of bytes */ \
+	 sizeof(__be32))	/* number of extents */
+
+struct pnfs_block_extent {
+	struct nfsd4_deviceid		vol_id;
+	u64				foff;
+	u64				len;
+	u64				soff;
+	enum pnfs_block_extent_state	es;
+};
+
+struct pnfs_block_range {
+	u64				foff;
+	u64				len;
+};
+
+struct pnfs_block_layout {
+	u32				nr_extents;
+	struct pnfs_block_extent	extents[] __counted_by(nr_extents);
+};
+
+/*
+ * Random upper cap for the uuid length to avoid unbounded allocation.
+ * Not actually limited by the protocol.
+ */
+#define PNFS_BLOCK_UUID_LEN	128
+
+struct pnfs_block_volume {
+	enum pnfs_block_volume_type	type;
+	union {
+		struct {
+			u64		offset;
+			u32		sig_len;
+			u8		sig[PNFS_BLOCK_UUID_LEN];
+		} simple;
+		struct {
+			enum scsi_code_set		code_set;
+			enum scsi_designator_type	designator_type;
+			int				designator_len;
+			u8				designator[256];
+			u64				pr_key;
+		} scsi;
+	};
+};
+
+struct pnfs_block_deviceaddr {
+	u32				nr_volumes;
+	struct pnfs_block_volume	volumes[] __counted_by(nr_volumes);
+};
+
+__be32 nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
+		const struct nfsd4_getdeviceinfo *gdp);
+__be32 nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
+		const struct nfsd4_layoutget *lgp);
+__be32 nfsd4_block_decode_layoutupdate(struct xdr_stream *xdr,
+		struct iomap **iomapp, int *nr_iomapsp, u32 block_size);
+__be32 nfsd4_scsi_decode_layoutupdate(struct xdr_stream *xdr,
+		struct iomap **iomapp, int *nr_iomapsp, u32 block_size);
+
+#endif /* _NFSD_BLOCKLAYOUTXDR_H */
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
new file mode 100644
index 000000000..3bc4856e3
--- /dev/null
+++ b/fs/nfsd/cache.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Request reply cache. This was heavily inspired by the
+ * implementation in 4.3BSD/4.4BSD.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef NFSCACHE_H
+#define NFSCACHE_H
+
+#include <linux/sunrpc/svc.h>
+
+struct nfsd_net;
+
+/*
+ * Representation of a reply cache entry.
+ *
+ * Note that we use a sockaddr_in6 to hold the address instead of the more
+ * typical sockaddr_storage. This is for space reasons, since sockaddr_storage
+ * is much larger than a sockaddr_in6.
+ */
+struct nfsd_cacherep {
+	struct {
+		/* Keep often-read xid, csum in the same cache line: */
+		__be32			k_xid;
+		__wsum			k_csum;
+		u32			k_proc;
+		u32			k_prot;
+		u32			k_vers;
+		unsigned int		k_len;
+		struct sockaddr_in6	k_addr;
+	} c_key;
+
+	struct rb_node		c_node;
+	struct list_head	c_lru;
+	unsigned char		c_state,	/* unused, inprog, done */
+				c_type,		/* status, buffer */
+				c_secure : 1;	/* req came from port < 1024 */
+	unsigned long		c_timestamp;
+	union {
+		struct kvec	u_vec;
+		__be32		u_status;
+	}			c_u;
+};
+
+#define c_replvec		c_u.u_vec
+#define c_replstat		c_u.u_status
+
+/* cache entry states */
+enum {
+	RC_UNUSED,
+	RC_INPROG,
+	RC_DONE
+};
+
+/* return values */
+enum {
+	RC_DROPIT,
+	RC_REPLY,
+	RC_DOIT
+};
+
+/*
+ * Cache types.
+ * We may want to add more types one day, e.g. for diropres and
+ * attrstat replies. Using cache entries with fixed length instead
+ * of buffer pointers may be more efficient.
+ */
+enum {
+	RC_NOCACHE,
+	RC_REPLSTAT,
+	RC_REPLBUFF,
+};
+
+/* Cache entries expire after this time period */
+#define RC_EXPIRE		(120 * HZ)
+
+/* Checksum this amount of the request */
+#define RC_CSUMLEN		(256U)
+
+int	nfsd_drc_slab_create(void);
+void	nfsd_drc_slab_free(void);
+int	nfsd_reply_cache_init(struct nfsd_net *);
+void	nfsd_reply_cache_shutdown(struct nfsd_net *);
+int	nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
+			  unsigned int len, struct nfsd_cacherep **cacherep);
+void	nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
+			  int cachetype, __be32 *statp);
+int	nfsd_reply_cache_stats_show(struct seq_file *m, void *v);
+
+#endif /* NFSCACHE_H */
diff --git a/fs/nfsd/current_stateid.h b/fs/nfsd/current_stateid.h
new file mode 100644
index 000000000..c28540d86
--- /dev/null
+++ b/fs/nfsd/current_stateid.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NFSD4_CURRENT_STATE_H
+#define _NFSD4_CURRENT_STATE_H
+
+#include "state.h"
+#include "xdr4.h"
+
+extern void clear_current_stateid(struct nfsd4_compound_state *cstate);
+/*
+ * functions to set current state id
+ */
+extern void nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_openstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_lockstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_closestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+
+/*
+ * functions to consume current state id
+ */
+extern void nfsd4_get_opendowngradestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_delegreturnstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_freestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_setattrstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_closestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_lockustateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_readstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_writestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+
+#endif   /* _NFSD4_CURRENT_STATE_H */
diff --git a/fs/nfsd/debugfs.c b/fs/nfsd/debugfs.c
new file mode 100644
index 000000000..386fd1c54
--- /dev/null
+++ b/fs/nfsd/debugfs.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/debugfs.h>
+
+#include "nfsd.h"
+
+static struct dentry *nfsd_top_dir __read_mostly;
+
+/*
+ * /sys/kernel/debug/nfsd/disable-splice-read
+ *
+ * Contents:
+ *   %0: NFS READ is allowed to use page splicing
+ *   %1: NFS READ uses only iov iter read
+ *
+ * The default value of this setting is zero (page splicing is
+ * allowed). This setting takes immediate effect for all NFS
+ * versions, all exports, and in all NFSD net namespaces.
+ */
+
+static int nfsd_dsr_get(void *data, u64 *val)
+{
+	*val = nfsd_disable_splice_read ? 1 : 0;
+	return 0;
+}
+
+static int nfsd_dsr_set(void *data, u64 val)
+{
+	nfsd_disable_splice_read = (val > 0);
+	if (!nfsd_disable_splice_read) {
+		/*
+		 * Must use buffered I/O if splice_read is enabled.
+		 */
+		nfsd_io_cache_read = NFSD_IO_BUFFERED;
+	}
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(nfsd_dsr_fops, nfsd_dsr_get, nfsd_dsr_set, "%llu\n");
+
+/*
+ * /sys/kernel/debug/nfsd/io_cache_read
+ *
+ * Contents:
+ *   %0: NFS READ will use buffered IO
+ *   %1: NFS READ will use dontcache (buffered IO w/ dropbehind)
+ *   %2: NFS READ will use direct IO
+ *
+ * This setting takes immediate effect for all NFS versions,
+ * all exports, and in all NFSD net namespaces.
+ */
+
+static int nfsd_io_cache_read_get(void *data, u64 *val)
+{
+	*val = nfsd_io_cache_read;
+	return 0;
+}
+
+static int nfsd_io_cache_read_set(void *data, u64 val)
+{
+	int ret = 0;
+
+	switch (val) {
+	case NFSD_IO_BUFFERED:
+		nfsd_io_cache_read = NFSD_IO_BUFFERED;
+		break;
+	case NFSD_IO_DONTCACHE:
+	case NFSD_IO_DIRECT:
+		/*
+		 * Must disable splice_read when enabling
+		 * NFSD_IO_DONTCACHE.
+		 */
+		nfsd_disable_splice_read = true;
+		nfsd_io_cache_read = val;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(nfsd_io_cache_read_fops, nfsd_io_cache_read_get,
+			 nfsd_io_cache_read_set, "%llu\n");
+
+/*
+ * /sys/kernel/debug/nfsd/io_cache_write
+ *
+ * Contents:
+ *   %0: NFS WRITE will use buffered IO
+ *   %1: NFS WRITE will use dontcache (buffered IO w/ dropbehind)
+ *
+ * This setting takes immediate effect for all NFS versions,
+ * all exports, and in all NFSD net namespaces.
+ */
+
+static int nfsd_io_cache_write_get(void *data, u64 *val)
+{
+	*val = nfsd_io_cache_write;
+	return 0;
+}
+
+static int nfsd_io_cache_write_set(void *data, u64 val)
+{
+	int ret = 0;
+
+	switch (val) {
+	case NFSD_IO_BUFFERED:
+	case NFSD_IO_DONTCACHE:
+	case NFSD_IO_DIRECT:
+		nfsd_io_cache_write = val;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(nfsd_io_cache_write_fops, nfsd_io_cache_write_get,
+			 nfsd_io_cache_write_set, "%llu\n");
+
+void nfsd_debugfs_exit(void)
+{
+	debugfs_remove_recursive(nfsd_top_dir);
+	nfsd_top_dir = NULL;
+}
+
+void nfsd_debugfs_init(void)
+{
+	nfsd_top_dir = debugfs_create_dir("nfsd", NULL);
+
+	debugfs_create_file("disable-splice-read", S_IWUSR | S_IRUGO,
+			    nfsd_top_dir, NULL, &nfsd_dsr_fops);
+
+	debugfs_create_file("io_cache_read", 0644, nfsd_top_dir, NULL,
+			    &nfsd_io_cache_read_fops);
+
+	debugfs_create_file("io_cache_write", 0644, nfsd_top_dir, NULL,
+			    &nfsd_io_cache_write_fops);
+#ifdef CONFIG_NFSD_V4
+	debugfs_create_bool("delegated_timestamps", 0644, nfsd_top_dir,
+			    &nfsd_delegts_enabled);
+#endif
+}
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
new file mode 100644
index 000000000..a7ebce53f
--- /dev/null
+++ b/fs/nfsd/export.c
@@ -0,0 +1,2251 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NFS exporting and validation.
+ *
+ * We maintain a list of clients, each of which has a list of
+ * exports. To export an fs to a given client, you first have
+ * to create the client entry with NFSCTL_ADDCLIENT, which
+ * creates a client control block and adds it to the hash
+ * table. Then, you call NFSCTL_EXPORT for each fs.
+ *
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/module.h>
+#include <linux/exportfs.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <net/genetlink.h>
+#include <uapi/linux/nfsd_netlink.h>
+
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "trace.h"
+#include "netlink.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_EXPORT
+
+/*
+ * We have two caches.
+ * One maps client+vfsmnt+dentry to export options - the export map
+ * The other maps client+filehandle-fragment to export options. - the expkey map
+ *
+ * The export options are actually stored in the first map, and the
+ * second map contains a reference to the entry in the first map.
+ */
+
+#define	EXPKEY_HASHBITS		8
+#define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
+#define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
+
+static void expkey_put(struct kref *ref)
+{
+	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
+
+	if (test_bit(CACHE_VALID, &key->h.flags) &&
+	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
+		path_put(&key->ek_path);
+	auth_domain_put(key->ek_client);
+	kfree_rcu(key, ek_rcu);
+}
+
+static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_upcall(cd, h);
+}
+
+static void expkey_request(struct cache_detail *cd,
+			   struct cache_head *h,
+			   char **bpp, int *blen)
+{
+	/* client fsidtype \xfsid */
+	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
+	char type[5];
+
+	qword_add(bpp, blen, ek->ek_client->name);
+	snprintf(type, 5, "%d", ek->ek_fsidtype);
+	qword_add(bpp, blen, type);
+	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
+	(*bpp)[-1] = '\n';
+}
+
+static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+					    struct svc_expkey *old);
+static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
+
+static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client fsidtype fsid expiry [path] */
+	char *buf;
+	int len;
+	struct auth_domain *dom = NULL;
+	int err;
+	u8 fsidtype;
+	struct svc_expkey key;
+	struct svc_expkey *ek = NULL;
+
+	if (mesg[mlen - 1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	err = -ENOMEM;
+	if (!buf)
+		goto out;
+
+	err = -EINVAL;
+	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
+		goto out;
+
+	err = -ENOENT;
+	dom = auth_domain_find(buf);
+	if (!dom)
+		goto out;
+	dprintk("found domain %s\n", buf);
+
+	err = -EINVAL;
+	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
+		goto out;
+	if (kstrtou8(buf, 10, &fsidtype))
+		goto out;
+	dprintk("found fsidtype %u\n", fsidtype);
+	if (key_len(fsidtype)==0) /* invalid type */
+		goto out;
+	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+		goto out;
+	dprintk("found fsid length %d\n", len);
+	if (len != key_len(fsidtype))
+		goto out;
+
+	/* OK, we seem to have a valid key */
+	key.h.flags = 0;
+	err = get_expiry(&mesg, &key.h.expiry_time);
+	if (err)
+		goto out;
+
+	key.ek_client = dom;
+	key.ek_fsidtype = fsidtype;
+	memcpy(key.ek_fsid, buf, len);
+
+	ek = svc_expkey_lookup(cd, &key);
+	err = -ENOMEM;
+	if (!ek)
+		goto out;
+
+	/* now we want a pathname, or empty meaning NEGATIVE  */
+	err = -EINVAL;
+	len = qword_get(&mesg, buf, PAGE_SIZE);
+	if (len < 0)
+		goto out;
+	dprintk("Path seems to be <%s>\n", buf);
+	err = 0;
+	if (len == 0) {
+		set_bit(CACHE_NEGATIVE, &key.h.flags);
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, NULL);
+		else
+			err = -ENOMEM;
+	} else {
+		err = kern_path(buf, 0, &key.ek_path);
+		if (err)
+			goto out;
+
+		dprintk("Found the path %s\n", buf);
+
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, buf);
+		else
+			err = -ENOMEM;
+		path_put(&key.ek_path);
+	}
+	cache_flush();
+ out:
+	if (ek)
+		cache_put(&ek->h, cd);
+	if (dom)
+		auth_domain_put(dom);
+	kfree(buf);
+	return err;
+}
+
+static int expkey_show(struct seq_file *m,
+		       struct cache_detail *cd,
+		       struct cache_head *h)
+{
+	struct svc_expkey *ek ;
+	int i;
+
+	if (h ==NULL) {
+		seq_puts(m, "#domain fsidtype fsid [path]\n");
+		return 0;
+	}
+	ek = container_of(h, struct svc_expkey, h);
+	seq_printf(m, "%s %d 0x", ek->ek_client->name,
+		   ek->ek_fsidtype);
+	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
+		seq_printf(m, "%08x", ek->ek_fsid[i]);
+	if (test_bit(CACHE_VALID, &h->flags) && 
+	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
+		seq_printf(m, " ");
+		seq_path(m, &ek->ek_path, "\\ \t\n");
+	}
+	seq_printf(m, "\n");
+	return 0;
+}
+
+static inline int expkey_match (struct cache_head *a, struct cache_head *b)
+{
+	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
+	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
+
+	if (orig->ek_fsidtype != new->ek_fsidtype ||
+	    orig->ek_client != new->ek_client ||
+	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
+		return 0;
+	return 1;
+}
+
+static inline void expkey_init(struct cache_head *cnew,
+				   struct cache_head *citem)
+{
+	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
+	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
+
+	kref_get(&item->ek_client->ref);
+	new->ek_client = item->ek_client;
+	new->ek_fsidtype = item->ek_fsidtype;
+
+	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
+}
+
+static inline void expkey_update(struct cache_head *cnew,
+				   struct cache_head *citem)
+{
+	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
+	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
+
+	new->ek_path = item->ek_path;
+	path_get(&item->ek_path);
+}
+
+static struct cache_head *expkey_alloc(void)
+{
+	struct svc_expkey *i = kmalloc_obj(*i);
+	if (i)
+		return &i->h;
+	else
+		return NULL;
+}
+
+static void expkey_flush(void)
+{
+	/*
+	 * Take the nfsd_mutex here to ensure that the file cache is not
+	 * destroyed while we're in the middle of flushing.
+	 */
+	mutex_lock(&nfsd_mutex);
+	nfsd_file_cache_purge(current->nsproxy->net_ns);
+	mutex_unlock(&nfsd_mutex);
+}
+
+static int expkey_notify(struct cache_detail *cd, struct cache_head *h)
+{
+	return nfsd_cache_notify(cd, h, NFSD_CACHE_TYPE_EXPKEY);
+}
+
+static const struct cache_detail svc_expkey_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPKEY_HASHMAX,
+	.name		= "nfsd.fh",
+	.cache_put	= expkey_put,
+	.cache_upcall	= expkey_upcall,
+	.cache_notify	= expkey_notify,
+	.cache_request	= expkey_request,
+	.cache_parse	= expkey_parse,
+	.cache_show	= expkey_show,
+	.match		= expkey_match,
+	.init		= expkey_init,
+	.update       	= expkey_update,
+	.alloc		= expkey_alloc,
+	.flush		= expkey_flush,
+};
+
+static int
+svc_expkey_hash(struct svc_expkey *item)
+{
+	int hash = item->ek_fsidtype;
+	char * cp = (char*)item->ek_fsid;
+	int len = key_len(item->ek_fsidtype);
+
+	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
+	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
+	hash &= EXPKEY_HASHMASK;
+	return hash;
+}
+
+static struct svc_expkey *
+svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(item);
+
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_expkey, h);
+	else
+		return NULL;
+}
+
+static struct svc_expkey *
+svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+		  struct svc_expkey *old)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(new);
+
+	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_expkey, h);
+	else
+		return NULL;
+}
+
+/**
+ * nfsd_nl_expkey_get_reqs_dumpit - dump pending expkey requests
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Walk the expkey cache's pending request list and create a netlink
+ * message with a nested entry for each cache_request, containing the
+ * seqno, client string, fsidtype and fsid.
+ *
+ * Uses cb->args[0] as a seqno cursor for dump continuation across
+ * multiple netlink messages.
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_expkey_get_reqs_dumpit(struct sk_buff *skb,
+				   struct netlink_callback *cb)
+{
+	struct nfsd_net *nn;
+	struct cache_detail *cd;
+	struct cache_head **items;
+	u64 *seqnos;
+	int cnt, i, emitted;
+	void *hdr;
+	int ret;
+
+	nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+
+	cd = nn->svc_expkey_cache;
+	if (!cd) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	cnt = sunrpc_cache_requests_count(cd);
+	if (!cnt) {
+		ret = 0;
+		goto out_unlock;
+	}
+
+	items = kzalloc_objs(*items, cnt);
+	seqnos = kcalloc(cnt, sizeof(*seqnos), GFP_KERNEL);
+	if (!items || !seqnos) {
+		ret = -ENOMEM;
+		goto out_alloc;
+	}
+
+	cnt = sunrpc_cache_requests_snapshot(cd, items, seqnos, cnt,
+					     cb->args[0]);
+	if (!cnt) {
+		ret = 0;
+		goto out_alloc;
+	}
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+			  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+			  NLM_F_MULTI, NFSD_CMD_EXPKEY_GET_REQS);
+	if (!hdr) {
+		ret = -ENOBUFS;
+		goto out_put;
+	}
+
+	emitted = 0;
+	for (i = 0; i < cnt; i++) {
+		struct svc_expkey *ek;
+		struct nlattr *nest;
+
+		ek = container_of(items[i], struct svc_expkey, h);
+
+		nest = nla_nest_start(skb, NFSD_A_EXPKEY_REQS_REQUESTS);
+		if (!nest)
+			break;
+
+		if (nla_put_u64_64bit(skb, NFSD_A_EXPKEY_SEQNO,
+				      seqnos[i], 0) ||
+		    nla_put_string(skb, NFSD_A_EXPKEY_CLIENT,
+				   ek->ek_client->name) ||
+		    nla_put_u8(skb, NFSD_A_EXPKEY_FSIDTYPE,
+			       ek->ek_fsidtype) ||
+		    nla_put(skb, NFSD_A_EXPKEY_FSID,
+			    key_len(ek->ek_fsidtype), ek->ek_fsid)) {
+			nla_nest_cancel(skb, nest);
+			break;
+		}
+
+		nla_nest_end(skb, nest);
+		cb->args[0] = seqnos[i];
+		emitted++;
+	}
+
+	if (!emitted) {
+		genlmsg_cancel(skb, hdr);
+		ret = -EMSGSIZE;
+		goto out_put;
+	}
+
+	genlmsg_end(skb, hdr);
+	ret = skb->len;
+out_put:
+	for (i = 0; i < cnt; i++)
+		cache_put(items[i], cd);
+out_alloc:
+	kfree(seqnos);
+	kfree(items);
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
+
+/**
+ * nfsd_nl_parse_one_expkey - parse one expkey entry from netlink
+ * @cd: cache_detail for the expkey cache
+ * @attr: nested attribute containing expkey fields
+ *
+ * Parses one expkey entry from a netlink message and updates the
+ * cache. Mirrors the logic in expkey_parse().
+ *
+ * Returns 0 on success or a negative errno.
+ */
+static int nfsd_nl_parse_one_expkey(struct cache_detail *cd,
+				    struct nlattr *attr)
+{
+	struct nlattr *tb[NFSD_A_EXPKEY_PATH + 1];
+	struct auth_domain *dom = NULL;
+	struct svc_expkey key;
+	struct svc_expkey *ek = NULL;
+	struct timespec64 boot;
+	int err;
+	u8 fsidtype;
+	int fsid_len;
+
+	err = nla_parse_nested(tb, NFSD_A_EXPKEY_PATH, attr,
+			       nfsd_expkey_nl_policy, NULL);
+	if (err)
+		return err;
+
+	/* client (required) */
+	if (!tb[NFSD_A_EXPKEY_CLIENT])
+		return -EINVAL;
+
+	dom = auth_domain_find(nla_data(tb[NFSD_A_EXPKEY_CLIENT]));
+	if (!dom)
+		return -ENOENT;
+
+	/* fsidtype (required) */
+	if (!tb[NFSD_A_EXPKEY_FSIDTYPE]) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+	fsidtype = nla_get_u8(tb[NFSD_A_EXPKEY_FSIDTYPE]);
+	if (key_len(fsidtype) == 0) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+
+	/* fsid (required) */
+	if (!tb[NFSD_A_EXPKEY_FSID]) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+	fsid_len = nla_len(tb[NFSD_A_EXPKEY_FSID]);
+	if (fsid_len != key_len(fsidtype)) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+
+	/* expiry (required, wallclock seconds) */
+	if (!tb[NFSD_A_EXPKEY_EXPIRY]) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+
+	key.h.flags = 0;
+	getboottime64(&boot);
+	key.h.expiry_time = nla_get_u64(tb[NFSD_A_EXPKEY_EXPIRY]) -
+			    boot.tv_sec;
+	key.ek_client = dom;
+	key.ek_fsidtype = fsidtype;
+	memcpy(key.ek_fsid, nla_data(tb[NFSD_A_EXPKEY_FSID]), fsid_len);
+
+	ek = svc_expkey_lookup(cd, &key);
+	if (!ek) {
+		err = -ENOMEM;
+		goto out_dom;
+	}
+
+	if (tb[NFSD_A_EXPKEY_NEGATIVE]) {
+		set_bit(CACHE_NEGATIVE, &key.h.flags);
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, NULL);
+		else
+			err = -ENOMEM;
+	} else if (tb[NFSD_A_EXPKEY_PATH]) {
+		err = kern_path(nla_data(tb[NFSD_A_EXPKEY_PATH]), 0,
+				&key.ek_path);
+		if (err)
+			goto out_ek;
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek,
+					nla_data(tb[NFSD_A_EXPKEY_PATH]));
+		else
+			err = -ENOMEM;
+		path_put(&key.ek_path);
+	} else {
+		err = -EINVAL;
+		goto out_ek;
+	}
+
+	cache_flush();
+
+out_ek:
+	if (ek)
+		cache_put(&ek->h, cd);
+out_dom:
+	auth_domain_put(dom);
+	return err;
+}
+
+/**
+ * nfsd_nl_expkey_set_reqs_doit - respond to expkey requests
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Parse one or more expkey cache responses from userspace and
+ * update the expkey cache accordingly.
+ *
+ * Returns 0 on success or a negative errno.
+ */
+int nfsd_nl_expkey_set_reqs_doit(struct sk_buff *skb,
+				 struct genl_info *info)
+{
+	struct nfsd_net *nn;
+	struct cache_detail *cd;
+	const struct nlattr *attr;
+	int rem, ret = 0;
+
+	nn = net_generic(genl_info_net(info), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+
+	cd = nn->svc_expkey_cache;
+	if (!cd) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	nlmsg_for_each_attr_type(attr, NFSD_A_EXPKEY_REQS_REQUESTS,
+				 info->nlhdr, GENL_HDRLEN, rem) {
+		ret = nfsd_nl_parse_one_expkey(cd, (struct nlattr *)attr);
+		if (ret)
+			break;
+	}
+
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
+
+#define	EXPORT_HASHBITS		8
+#define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
+
+static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
+{
+	struct nfsd4_fs_location *locations = fsloc->locations;
+	int i;
+
+	if (!locations)
+		return;
+
+	for (i = 0; i < fsloc->locations_count; i++) {
+		kfree(locations[i].path);
+		kfree(locations[i].hosts);
+	}
+
+	kfree(locations);
+	fsloc->locations = NULL;
+}
+
+static int export_stats_init(struct export_stats *stats)
+{
+	stats->start_time = ktime_get_seconds();
+	return percpu_counter_init_many(stats->counter, 0, GFP_KERNEL,
+					EXP_STATS_COUNTERS_NUM);
+}
+
+static void export_stats_reset(struct export_stats *stats)
+{
+	if (stats) {
+		int i;
+
+		for (i = 0; i < EXP_STATS_COUNTERS_NUM; i++)
+			percpu_counter_set(&stats->counter[i], 0);
+	}
+}
+
+static void export_stats_destroy(struct export_stats *stats)
+{
+	if (stats)
+		percpu_counter_destroy_many(stats->counter,
+					    EXP_STATS_COUNTERS_NUM);
+}
+
+static void svc_export_release(struct rcu_head *rcu_head)
+{
+	struct svc_export *exp = container_of(rcu_head, struct svc_export,
+			ex_rcu);
+
+	nfsd4_fslocs_free(&exp->ex_fslocs);
+	export_stats_destroy(exp->ex_stats);
+	kfree(exp->ex_stats);
+	kfree(exp->ex_uuid);
+	kfree(exp);
+}
+
+static void svc_export_put(struct kref *ref)
+{
+	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
+
+	path_put(&exp->ex_path);
+	auth_domain_put(exp->ex_client);
+	call_rcu(&exp->ex_rcu, svc_export_release);
+}
+
+/**
+ * nfsd_nl_svc_export_get_reqs_dumpit - dump pending svc_export requests
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Walk the svc_export cache's pending request list and create a netlink
+ * message with a nested entry for each cache_request, containing the
+ * seqno, client string, and path.
+ *
+ * Uses cb->args[0] as a seqno cursor for dump continuation across
+ * multiple netlink messages.
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_svc_export_get_reqs_dumpit(struct sk_buff *skb,
+				       struct netlink_callback *cb)
+{
+	struct nfsd_net *nn;
+	struct cache_detail *cd;
+	struct cache_head **items;
+	u64 *seqnos;
+	int cnt, i, emitted;
+	char *pathbuf;
+	void *hdr;
+	int ret;
+
+	nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+
+	cd = nn->svc_export_cache;
+	if (!cd) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	cnt = sunrpc_cache_requests_count(cd);
+	if (!cnt) {
+		ret = 0;
+		goto out_unlock;
+	}
+
+	items = kzalloc_objs(*items, cnt);
+	seqnos = kcalloc(cnt, sizeof(*seqnos), GFP_KERNEL);
+	pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!items || !seqnos || !pathbuf) {
+		ret = -ENOMEM;
+		goto out_alloc;
+	}
+
+	cnt = sunrpc_cache_requests_snapshot(cd, items, seqnos, cnt,
+					     cb->args[0]);
+	if (!cnt) {
+		ret = 0;
+		goto out_alloc;
+	}
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+			  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+			  NLM_F_MULTI, NFSD_CMD_SVC_EXPORT_GET_REQS);
+	if (!hdr) {
+		ret = -ENOBUFS;
+		goto out_put;
+	}
+
+	emitted = 0;
+	for (i = 0; i < cnt; i++) {
+		struct svc_export *exp;
+		struct nlattr *nest;
+		char *pth;
+
+		exp = container_of(items[i], struct svc_export, h);
+
+		pth = d_path(&exp->ex_path, pathbuf, PATH_MAX);
+		if (IS_ERR(pth))
+			continue;
+
+		nest = nla_nest_start(skb,
+				      NFSD_A_SVC_EXPORT_REQS_REQUESTS);
+		if (!nest)
+			break;
+
+		if (nla_put_u64_64bit(skb, NFSD_A_SVC_EXPORT_SEQNO,
+				      seqnos[i], 0) ||
+		    nla_put_string(skb, NFSD_A_SVC_EXPORT_CLIENT,
+				   exp->ex_client->name) ||
+		    nla_put_string(skb, NFSD_A_SVC_EXPORT_PATH, pth)) {
+			nla_nest_cancel(skb, nest);
+			break;
+		}
+
+		nla_nest_end(skb, nest);
+		cb->args[0] = seqnos[i];
+		emitted++;
+	}
+
+	if (!emitted) {
+		genlmsg_cancel(skb, hdr);
+		ret = -EMSGSIZE;
+		goto out_put;
+	}
+
+	genlmsg_end(skb, hdr);
+	ret = skb->len;
+out_put:
+	for (i = 0; i < cnt; i++)
+		cache_put(items[i], cd);
+out_alloc:
+	kfree(pathbuf);
+	kfree(seqnos);
+	kfree(items);
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
+
+/**
+ * nfsd_nl_parse_fslocations - parse fslocations from netlink
+ * @attr: NFSD_A_SVC_EXPORT_FSLOCATIONS nested attribute
+ * @fsloc: fslocations struct to fill in
+ *
+ * Returns 0 on success or a negative errno.
+ */
+static int nfsd_nl_parse_fslocations(struct nlattr *attr,
+				     struct nfsd4_fs_locations *fsloc)
+{
+	struct nlattr *loc_attr;
+	int rem, count = 0;
+	int err;
+
+	if (fsloc->locations)
+		return -EINVAL;
+
+	/* Count locations first */
+	nla_for_each_nested_type(loc_attr, NFSD_A_FSLOCATIONS_LOCATION,
+				 attr, rem)
+		count++;
+
+	if (count > MAX_FS_LOCATIONS)
+		return -EINVAL;
+	if (!count)
+		return 0;
+
+	fsloc->locations = kzalloc_objs(struct nfsd4_fs_location, count);
+	if (!fsloc->locations)
+		return -ENOMEM;
+
+	nla_for_each_nested_type(loc_attr, NFSD_A_FSLOCATIONS_LOCATION,
+				 attr, rem) {
+		struct nlattr *tb[NFSD_A_FSLOCATION_PATH + 1];
+		struct nfsd4_fs_location *loc;
+
+		err = nla_parse_nested(tb, NFSD_A_FSLOCATION_PATH, loc_attr,
+				       nfsd_fslocation_nl_policy, NULL);
+		if (err)
+			goto out_free;
+
+		if (!tb[NFSD_A_FSLOCATION_HOST] ||
+		    !tb[NFSD_A_FSLOCATION_PATH]) {
+			err = -EINVAL;
+			goto out_free;
+		}
+
+		loc = &fsloc->locations[fsloc->locations_count++];
+		loc->hosts = kstrdup(nla_data(tb[NFSD_A_FSLOCATION_HOST]),
+				     GFP_KERNEL);
+		loc->path = kstrdup(nla_data(tb[NFSD_A_FSLOCATION_PATH]),
+				    GFP_KERNEL);
+		if (!loc->hosts || !loc->path) {
+			err = -ENOMEM;
+			goto out_free;
+		}
+	}
+
+	return 0;
+out_free:
+	nfsd4_fslocs_free(fsloc);
+	return err;
+}
+
+static struct svc_export *svc_export_update(struct svc_export *new,
+					    struct svc_export *old);
+static struct svc_export *svc_export_lookup(struct svc_export *);
+static int check_export(const struct path *path, int *flags,
+			unsigned char *uuid);
+
+/**
+ * nfsd_nl_parse_one_export - parse one svc_export entry from a netlink message
+ * @cd: cache_detail for the svc_export cache
+ * @attr: nested attribute containing svc-export fields
+ *
+ * Parses one svc-export entry from a netlink message and updates the
+ * cache. Mirrors the logic in svc_export_parse().
+ *
+ * Returns 0 on success or a negative errno.
+ */
+static int nfsd_nl_parse_one_export(struct cache_detail *cd,
+				    struct nlattr *attr)
+{
+	struct nlattr *tb[NFSD_A_SVC_EXPORT_FSID + 1];
+	struct auth_domain *dom = NULL;
+	struct svc_export exp = {}, *expp;
+	struct nlattr *secinfo_attr;
+	struct timespec64 boot;
+	int err, rem;
+
+	err = nla_parse_nested(tb, NFSD_A_SVC_EXPORT_FSID, attr,
+			       nfsd_svc_export_nl_policy, NULL);
+	if (err)
+		return err;
+
+	/* client (required) */
+	if (!tb[NFSD_A_SVC_EXPORT_CLIENT])
+		return -EINVAL;
+
+	dom = auth_domain_find(nla_data(tb[NFSD_A_SVC_EXPORT_CLIENT]));
+	if (!dom)
+		return -ENOENT;
+
+	/* path (required) */
+	if (!tb[NFSD_A_SVC_EXPORT_PATH]) {
+		err = -EINVAL;
+		goto out_dom;
+	}
+
+	err = kern_path(nla_data(tb[NFSD_A_SVC_EXPORT_PATH]), 0,
+			&exp.ex_path);
+	if (err)
+		goto out_dom;
+
+	exp.ex_client = dom;
+	exp.cd = cd;
+	exp.ex_devid_map = NULL;
+	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
+
+	/* expiry (required, wallclock seconds) */
+	if (!tb[NFSD_A_SVC_EXPORT_EXPIRY]) {
+		err = -EINVAL;
+		goto out_path;
+	}
+	getboottime64(&boot);
+	exp.h.expiry_time = nla_get_u64(tb[NFSD_A_SVC_EXPORT_EXPIRY]) -
+			    boot.tv_sec;
+
+	if (tb[NFSD_A_SVC_EXPORT_NEGATIVE]) {
+		set_bit(CACHE_NEGATIVE, &exp.h.flags);
+	} else {
+		/* flags */
+		if (tb[NFSD_A_SVC_EXPORT_FLAGS])
+			exp.ex_flags = nla_get_u32(tb[NFSD_A_SVC_EXPORT_FLAGS]);
+
+		/* anon uid */
+		if (tb[NFSD_A_SVC_EXPORT_ANON_UID]) {
+			u32 uid = nla_get_u32(tb[NFSD_A_SVC_EXPORT_ANON_UID]);
+
+			exp.ex_anon_uid = make_kuid(current_user_ns(), uid);
+		}
+
+		/* anon gid */
+		if (tb[NFSD_A_SVC_EXPORT_ANON_GID]) {
+			u32 gid = nla_get_u32(tb[NFSD_A_SVC_EXPORT_ANON_GID]);
+
+			exp.ex_anon_gid = make_kgid(current_user_ns(), gid);
+		}
+
+		/* fsid */
+		if (tb[NFSD_A_SVC_EXPORT_FSID])
+			exp.ex_fsid = nla_get_s32(tb[NFSD_A_SVC_EXPORT_FSID]);
+
+		/* fslocations */
+		if (tb[NFSD_A_SVC_EXPORT_FSLOCATIONS]) {
+			struct nlattr *fsl = tb[NFSD_A_SVC_EXPORT_FSLOCATIONS];
+
+			err = nfsd_nl_parse_fslocations(fsl,
+							&exp.ex_fslocs);
+			if (err)
+				goto out_path;
+		}
+
+		/* uuid */
+		if (tb[NFSD_A_SVC_EXPORT_UUID]) {
+			if (nla_len(tb[NFSD_A_SVC_EXPORT_UUID]) !=
+			    EX_UUID_LEN) {
+				err = -EINVAL;
+				goto out_fslocs;
+			}
+			exp.ex_uuid = kmemdup(nla_data(tb[NFSD_A_SVC_EXPORT_UUID]),
+					      EX_UUID_LEN, GFP_KERNEL);
+			if (!exp.ex_uuid) {
+				err = -ENOMEM;
+				goto out_fslocs;
+			}
+		}
+
+		/* secinfo (multi-attr) */
+		nla_for_each_nested_type(secinfo_attr,
+					 NFSD_A_SVC_EXPORT_SECINFO,
+					 attr, rem) {
+			struct nlattr *ftb[NFSD_A_AUTH_FLAVOR_FLAGS + 1];
+			struct exp_flavor_info *f;
+
+			if (exp.ex_nflavors >= MAX_SECINFO_LIST) {
+				err = -EINVAL;
+				goto out_uuid;
+			}
+
+			err = nla_parse_nested(ftb,
+					       NFSD_A_AUTH_FLAVOR_FLAGS,
+					       secinfo_attr,
+					       nfsd_auth_flavor_nl_policy,
+					       NULL);
+			if (err)
+				goto out_uuid;
+
+			f = &exp.ex_flavors[exp.ex_nflavors++];
+
+			if (ftb[NFSD_A_AUTH_FLAVOR_PSEUDOFLAVOR])
+				f->pseudoflavor = nla_get_u32(ftb[NFSD_A_AUTH_FLAVOR_PSEUDOFLAVOR]);
+
+			if (ftb[NFSD_A_AUTH_FLAVOR_FLAGS])
+				f->flags = nla_get_u32(ftb[NFSD_A_AUTH_FLAVOR_FLAGS]);
+
+			/* Only some flags are allowed to differ between flavors: */
+			if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp.ex_flags)) {
+				err = -EINVAL;
+				goto out_uuid;
+			}
+		}
+
+		/* xprtsec (multi-attr u32) */
+		if (tb[NFSD_A_SVC_EXPORT_XPRTSEC]) {
+			struct nlattr *xp_attr;
+
+			exp.ex_xprtsec_modes = 0;
+			nla_for_each_nested_type(xp_attr,
+						 NFSD_A_SVC_EXPORT_XPRTSEC,
+						 attr, rem) {
+				u32 mode = nla_get_u32(xp_attr);
+
+				if (mode > NFSEXP_XPRTSEC_MTLS) {
+					err = -EINVAL;
+					goto out_uuid;
+				}
+				exp.ex_xprtsec_modes |= mode;
+			}
+		}
+
+		err = check_export(&exp.ex_path, &exp.ex_flags,
+				   exp.ex_uuid);
+		if (err)
+			goto out_uuid;
+
+		if (exp.h.expiry_time < seconds_since_boot())
+			goto out_uuid;
+
+		err = -EINVAL;
+		if (!uid_valid(exp.ex_anon_uid))
+			goto out_uuid;
+		if (!gid_valid(exp.ex_anon_gid))
+			goto out_uuid;
+		err = 0;
+
+		nfsd4_setup_layout_type(&exp);
+	}
+
+	expp = svc_export_lookup(&exp);
+	if (!expp) {
+		err = -ENOMEM;
+		goto out_uuid;
+	}
+	expp = svc_export_update(&exp, expp);
+	if (expp) {
+		trace_nfsd_export_update(expp);
+		cache_flush();
+		exp_put(expp);
+	} else {
+		err = -ENOMEM;
+	}
+
+out_uuid:
+	kfree(exp.ex_uuid);
+out_fslocs:
+	nfsd4_fslocs_free(&exp.ex_fslocs);
+out_path:
+	path_put(&exp.ex_path);
+out_dom:
+	auth_domain_put(dom);
+	return err;
+}
+
+/**
+ * nfsd_nl_svc_export_set_reqs_doit - respond to svc_export requests
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Parse one or more svc_export cache responses from userspace and
+ * update the export cache accordingly.
+ *
+ * Returns 0 on success or a negative errno.
+ */
+int nfsd_nl_svc_export_set_reqs_doit(struct sk_buff *skb,
+				     struct genl_info *info)
+{
+	struct nfsd_net *nn;
+	struct cache_detail *cd;
+	const struct nlattr *attr;
+	int rem, ret = 0;
+
+	nn = net_generic(genl_info_net(info), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+
+	cd = nn->svc_export_cache;
+	if (!cd) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	nlmsg_for_each_attr_type(attr, NFSD_A_SVC_EXPORT_REQS_REQUESTS,
+				 info->nlhdr, GENL_HDRLEN, rem) {
+		ret = nfsd_nl_parse_one_export(cd, (struct nlattr *)attr);
+		if (ret)
+			break;
+	}
+
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
+
+static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_upcall(cd, h);
+}
+
+static int svc_export_notify(struct cache_detail *cd, struct cache_head *h)
+{
+	return nfsd_cache_notify(cd, h, NFSD_CACHE_TYPE_SVC_EXPORT);
+}
+
+static void svc_export_request(struct cache_detail *cd,
+			       struct cache_head *h,
+			       char **bpp, int *blen)
+{
+	/*  client path */
+	struct svc_export *exp = container_of(h, struct svc_export, h);
+	char *pth;
+
+	qword_add(bpp, blen, exp->ex_client->name);
+	pth = d_path(&exp->ex_path, *bpp, *blen);
+	if (IS_ERR(pth)) {
+		/* is this correct? */
+		(*bpp)[0] = '\n';
+		return;
+	}
+	qword_add(bpp, blen, pth);
+	(*bpp)[-1] = '\n';
+}
+
+static int check_export(const struct path *path, int *flags, unsigned char *uuid)
+{
+	struct inode *inode = d_inode(path->dentry);
+
+	/*
+	 * We currently export only dirs, regular files, and (for v4
+	 * pseudoroot) symlinks.
+	 */
+	if (!S_ISDIR(inode->i_mode) &&
+	    !S_ISLNK(inode->i_mode) &&
+	    !S_ISREG(inode->i_mode))
+		return -ENOTDIR;
+
+	/*
+	 * Mountd should never pass down a writeable V4ROOT export, but,
+	 * just to make sure:
+	 */
+	if (*flags & NFSEXP_V4ROOT)
+		*flags |= NFSEXP_READONLY;
+
+	/* There are two requirements on a filesystem to be exportable.
+	 * 1:  We must be able to identify the filesystem from a number.
+	 *       either a device number (so FS_REQUIRES_DEV needed)
+	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
+	 * 2:  We must be able to find an inode from a filehandle.
+	 *       This means that s_export_op must be set and comply with
+	 *       the requirements for remote filesystem export.
+	 * 3: We must not currently be on an idmapped mount.
+	 */
+	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
+	    !(*flags & NFSEXP_FSID) &&
+	    uuid == NULL) {
+		dprintk("exp_export: export of non-dev fs without fsid\n");
+		return -EINVAL;
+	}
+
+	if (!exportfs_may_export(inode->i_sb->s_export_op)) {
+		dprintk("exp_export: export of invalid fs type (%s).\n",
+			inode->i_sb->s_type->name);
+		return -EINVAL;
+	}
+
+	if (is_idmapped_mnt(path->mnt)) {
+		dprintk("exp_export: export of idmapped mounts not yet supported.\n");
+		return -EINVAL;
+	}
+
+	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
+	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
+		dprintk("%s: %s does not support subtree checking!\n",
+			__func__, inode->i_sb->s_type->name);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_NFSD_V4
+
+static int
+fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
+{
+	int len;
+	int migrated, i, err;
+
+	/* more than one fsloc */
+	if (fsloc->locations)
+		return -EINVAL;
+
+	/* listsize */
+	err = get_uint(mesg, &fsloc->locations_count);
+	if (err)
+		return err;
+	if (fsloc->locations_count > MAX_FS_LOCATIONS)
+		return -EINVAL;
+	if (fsloc->locations_count == 0)
+		return 0;
+
+	fsloc->locations = kzalloc_objs(struct nfsd4_fs_location,
+					fsloc->locations_count);
+	if (!fsloc->locations)
+		return -ENOMEM;
+	for (i=0; i < fsloc->locations_count; i++) {
+		/* colon separated host list */
+		err = -EINVAL;
+		len = qword_get(mesg, buf, PAGE_SIZE);
+		if (len <= 0)
+			goto out_free_all;
+		err = -ENOMEM;
+		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
+		if (!fsloc->locations[i].hosts)
+			goto out_free_all;
+		err = -EINVAL;
+		/* slash separated path component list */
+		len = qword_get(mesg, buf, PAGE_SIZE);
+		if (len <= 0)
+			goto out_free_all;
+		err = -ENOMEM;
+		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
+		if (!fsloc->locations[i].path)
+			goto out_free_all;
+	}
+	/* migrated */
+	err = get_int(mesg, &migrated);
+	if (err)
+		goto out_free_all;
+	err = -EINVAL;
+	if (migrated < 0 || migrated > 1)
+		goto out_free_all;
+	fsloc->migrated = migrated;
+	return 0;
+out_free_all:
+	nfsd4_fslocs_free(fsloc);
+	return err;
+}
+
+static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	u32 listsize;
+	int err;
+
+	/* more than one secinfo */
+	if (exp->ex_nflavors)
+		return -EINVAL;
+
+	err = get_uint(mesg, &listsize);
+	if (err)
+		return err;
+	if (listsize > MAX_SECINFO_LIST)
+		return -EINVAL;
+
+	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
+		err = get_uint(mesg, &f->pseudoflavor);
+		if (err)
+			return err;
+		/*
+		 * XXX: It would be nice to also check whether this
+		 * pseudoflavor is supported, so we can discover the
+		 * problem at export time instead of when a client fails
+		 * to authenticate.
+		 */
+		err = get_uint(mesg, &f->flags);
+		if (err)
+			return err;
+		/* Only some flags are allowed to differ between flavors: */
+		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
+			return -EINVAL;
+	}
+	exp->ex_nflavors = listsize;
+	return 0;
+}
+
+#else /* CONFIG_NFSD_V4 */
+static inline int
+fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
+static inline int
+secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
+#endif
+
+static int xprtsec_parse(char **mesg, char *buf, struct svc_export *exp)
+{
+	unsigned int i, mode, listsize;
+	int err;
+
+	err = get_uint(mesg, &listsize);
+	if (err)
+		return err;
+	if (listsize > NFSEXP_XPRTSEC_NUM)
+		return -EINVAL;
+
+	exp->ex_xprtsec_modes = 0;
+	for (i = 0; i < listsize; i++) {
+		err = get_uint(mesg, &mode);
+		if (err)
+			return err;
+		if (mode > NFSEXP_XPRTSEC_MTLS)
+			return -EINVAL;
+		exp->ex_xprtsec_modes |= mode;
+	}
+	return 0;
+}
+
+static inline int
+nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
+{
+	int len;
+
+	/* more than one uuid */
+	if (*puuid)
+		return -EINVAL;
+
+	/* expect a 16 byte uuid encoded as \xXXXX... */
+	len = qword_get(mesg, buf, PAGE_SIZE);
+	if (len != EX_UUID_LEN)
+		return -EINVAL;
+
+	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
+	if (*puuid == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client path expiry [flags anonuid anongid fsid] */
+	char *buf;
+	int err;
+	struct auth_domain *dom = NULL;
+	struct svc_export exp = {}, *expp;
+	int an_int;
+
+	if (mesg[mlen-1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* client */
+	err = -EINVAL;
+	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
+		goto out;
+
+	err = -ENOENT;
+	dom = auth_domain_find(buf);
+	if (!dom)
+		goto out;
+
+	/* path */
+	err = -EINVAL;
+	if (qword_get(&mesg, buf, PAGE_SIZE) <= 0)
+		goto out1;
+
+	err = kern_path(buf, 0, &exp.ex_path);
+	if (err)
+		goto out1;
+
+	exp.ex_client = dom;
+	exp.cd = cd;
+	exp.ex_devid_map = NULL;
+	exp.ex_xprtsec_modes = NFSEXP_XPRTSEC_ALL;
+
+	/* expiry */
+	err = get_expiry(&mesg, &exp.h.expiry_time);
+	if (err)
+		goto out3;
+
+	/* flags */
+	err = get_int(&mesg, &an_int);
+	if (err == -ENOENT) {
+		err = 0;
+		set_bit(CACHE_NEGATIVE, &exp.h.flags);
+	} else {
+		if (err || an_int < 0)
+			goto out3;
+		exp.ex_flags= an_int;
+
+		/* anon uid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
+
+		/* anon gid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
+
+		/* fsid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_fsid = an_int;
+
+		while (qword_get(&mesg, buf, PAGE_SIZE) > 0) {
+			if (strcmp(buf, "fsloc") == 0)
+				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
+			else if (strcmp(buf, "uuid") == 0)
+				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
+			else if (strcmp(buf, "secinfo") == 0)
+				err = secinfo_parse(&mesg, buf, &exp);
+			else if (strcmp(buf, "xprtsec") == 0)
+				err = xprtsec_parse(&mesg, buf, &exp);
+			else
+				/* quietly ignore unknown words and anything
+				 * following. Newer user-space can try to set
+				 * new values, then see what the result was.
+				 */
+				break;
+			if (err)
+				goto out4;
+		}
+
+		err = check_export(&exp.ex_path, &exp.ex_flags, exp.ex_uuid);
+		if (err)
+			goto out4;
+
+		/*
+		 * No point caching this if it would immediately expire.
+		 * Also, this protects exportfs's dummy export from the
+		 * anon_uid/anon_gid checks:
+		 */
+		if (exp.h.expiry_time < seconds_since_boot())
+			goto out4;
+		/*
+		 * For some reason exportfs has been passing down an
+		 * invalid (-1) uid & gid on the "dummy" export which it
+		 * uses to test export support.  To make sure exportfs
+		 * sees errors from check_export we therefore need to
+		 * delay these checks till after check_export:
+		 */
+		err = -EINVAL;
+		if (!uid_valid(exp.ex_anon_uid))
+			goto out4;
+		if (!gid_valid(exp.ex_anon_gid))
+			goto out4;
+		err = 0;
+
+		if (exp.ex_flags & NFSEXP_PNFS)
+			nfsd4_setup_layout_type(&exp);
+	}
+
+	expp = svc_export_lookup(&exp);
+	if (!expp) {
+		err = -ENOMEM;
+		goto out4;
+	}
+	expp = svc_export_update(&exp, expp);
+	if (expp) {
+		trace_nfsd_export_update(expp);
+		cache_flush();
+		exp_put(expp);
+	} else
+		err = -ENOMEM;
+out4:
+	nfsd4_fslocs_free(&exp.ex_fslocs);
+	kfree(exp.ex_uuid);
+out3:
+	path_put(&exp.ex_path);
+out1:
+	auth_domain_put(dom);
+out:
+	kfree(buf);
+	return err;
+}
+
+static void exp_flags(struct seq_file *m, int flag, int fsid,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
+static void show_secinfo(struct seq_file *m, struct svc_export *exp);
+
+static int is_export_stats_file(struct seq_file *m)
+{
+	/*
+	 * The export_stats file uses the same ops as the exports file.
+	 * We use the file's name to determine the reported info per export.
+	 * There is no rename in nsfdfs, so d_name.name is stable.
+	 */
+	return !strcmp(m->file->f_path.dentry->d_name.name, "export_stats");
+}
+
+static int svc_export_show(struct seq_file *m,
+			   struct cache_detail *cd,
+			   struct cache_head *h)
+{
+	struct svc_export *exp;
+	bool export_stats = is_export_stats_file(m);
+
+	if (h == NULL) {
+		if (export_stats)
+			seq_puts(m, "#path domain start-time\n#\tstats\n");
+		else
+			seq_puts(m, "#path domain(flags)\n");
+		return 0;
+	}
+	exp = container_of(h, struct svc_export, h);
+	seq_path(m, &exp->ex_path, " \t\n\\");
+	seq_putc(m, '\t');
+	seq_escape(m, exp->ex_client->name, " \t\n\\");
+	if (export_stats) {
+		struct percpu_counter *counter = exp->ex_stats->counter;
+
+		seq_printf(m, "\t%lld\n", exp->ex_stats->start_time);
+		seq_printf(m, "\tfh_stale: %lld\n",
+			   percpu_counter_sum_positive(&counter[EXP_STATS_FH_STALE]));
+		seq_printf(m, "\tio_read: %lld\n",
+			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_READ]));
+		seq_printf(m, "\tio_write: %lld\n",
+			   percpu_counter_sum_positive(&counter[EXP_STATS_IO_WRITE]));
+		seq_putc(m, '\n');
+		return 0;
+	}
+	seq_putc(m, '(');
+	if (test_bit(CACHE_VALID, &h->flags) &&
+	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
+		exp_flags(m, exp->ex_flags, exp->ex_fsid,
+			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
+		if (exp->ex_uuid) {
+			int i;
+			seq_puts(m, ",uuid=");
+			for (i = 0; i < EX_UUID_LEN; i++) {
+				if ((i&3) == 0 && i)
+					seq_putc(m, ':');
+				seq_printf(m, "%02x", exp->ex_uuid[i]);
+			}
+		}
+		show_secinfo(m, exp);
+	}
+	seq_puts(m, ")\n");
+	return 0;
+}
+static int svc_export_match(struct cache_head *a, struct cache_head *b)
+{
+	struct svc_export *orig = container_of(a, struct svc_export, h);
+	struct svc_export *new = container_of(b, struct svc_export, h);
+	return orig->ex_client == new->ex_client &&
+		path_equal(&orig->ex_path, &new->ex_path);
+}
+
+static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct svc_export *new = container_of(cnew, struct svc_export, h);
+	struct svc_export *item = container_of(citem, struct svc_export, h);
+
+	kref_get(&item->ex_client->ref);
+	new->ex_client = item->ex_client;
+	new->ex_path = item->ex_path;
+	path_get(&item->ex_path);
+	new->ex_fslocs.locations = NULL;
+	new->ex_fslocs.locations_count = 0;
+	new->ex_fslocs.migrated = 0;
+	new->ex_layout_types = 0;
+	new->ex_uuid = NULL;
+	new->cd = item->cd;
+	export_stats_reset(new->ex_stats);
+}
+
+static void export_update(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct svc_export *new = container_of(cnew, struct svc_export, h);
+	struct svc_export *item = container_of(citem, struct svc_export, h);
+	int i;
+
+	new->ex_flags = item->ex_flags;
+	new->ex_anon_uid = item->ex_anon_uid;
+	new->ex_anon_gid = item->ex_anon_gid;
+	new->ex_fsid = item->ex_fsid;
+	new->ex_devid_map = item->ex_devid_map;
+	item->ex_devid_map = NULL;
+	new->ex_uuid = item->ex_uuid;
+	item->ex_uuid = NULL;
+	new->ex_fslocs.locations = item->ex_fslocs.locations;
+	item->ex_fslocs.locations = NULL;
+	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
+	item->ex_fslocs.locations_count = 0;
+	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
+	item->ex_fslocs.migrated = 0;
+	new->ex_layout_types = item->ex_layout_types;
+	new->ex_nflavors = item->ex_nflavors;
+	for (i = 0; i < MAX_SECINFO_LIST; i++) {
+		new->ex_flavors[i] = item->ex_flavors[i];
+	}
+	new->ex_xprtsec_modes = item->ex_xprtsec_modes;
+}
+
+static struct cache_head *svc_export_alloc(void)
+{
+	struct svc_export *i = kmalloc_obj(*i);
+	if (!i)
+		return NULL;
+
+	i->ex_stats = kmalloc_obj(*(i->ex_stats));
+	if (!i->ex_stats) {
+		kfree(i);
+		return NULL;
+	}
+
+	if (export_stats_init(i->ex_stats)) {
+		kfree(i->ex_stats);
+		kfree(i);
+		return NULL;
+	}
+
+	return &i->h;
+}
+
+static const struct cache_detail svc_export_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPORT_HASHMAX,
+	.name		= "nfsd.export",
+	.cache_put	= svc_export_put,
+	.cache_upcall	= svc_export_upcall,
+	.cache_notify	= svc_export_notify,
+	.cache_request	= svc_export_request,
+	.cache_parse	= svc_export_parse,
+	.cache_show	= svc_export_show,
+	.match		= svc_export_match,
+	.init		= svc_export_init,
+	.update		= export_update,
+	.alloc		= svc_export_alloc,
+};
+
+static int
+svc_export_hash(struct svc_export *exp)
+{
+	int hash;
+
+	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
+	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
+	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
+	return hash;
+}
+
+static struct svc_export *
+svc_export_lookup(struct svc_export *exp)
+{
+	struct cache_head *ch;
+	int hash = svc_export_hash(exp);
+
+	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_export, h);
+	else
+		return NULL;
+}
+
+static struct svc_export *
+svc_export_update(struct svc_export *new, struct svc_export *old)
+{
+	struct cache_head *ch;
+	int hash = svc_export_hash(old);
+
+	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_export, h);
+	else
+		return NULL;
+}
+
+
+static struct svc_expkey *
+exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
+	     u32 *fsidv, struct cache_req *reqp)
+{
+	struct svc_expkey key, *ek;
+	int err;
+	
+	if (!clp)
+		return ERR_PTR(-ENOENT);
+
+	key.ek_client = clp;
+	key.ek_fsidtype = fsid_type;
+	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
+
+	ek = svc_expkey_lookup(cd, &key);
+	if (ek == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &ek->h, reqp);
+	if (err) {
+		trace_nfsd_exp_find_key(&key, err);
+		return ERR_PTR(err);
+	}
+	return ek;
+}
+
+static struct svc_export *
+exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
+		const struct path *path, struct cache_req *reqp)
+{
+	struct svc_export *exp, key;
+	int err;
+
+	if (!clp)
+		return ERR_PTR(-ENOENT);
+
+	key.ex_client = clp;
+	key.ex_path = *path;
+	key.cd = cd;
+
+	exp = svc_export_lookup(&key);
+	if (exp == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &exp->h, reqp);
+	if (err) {
+		trace_nfsd_exp_get_by_name(&key, err);
+		return ERR_PTR(err);
+	}
+	return exp;
+}
+
+/*
+ * Find the export entry for a given dentry.
+ */
+static struct svc_export *
+exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
+{
+	struct dentry *saved = dget(path->dentry);
+	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
+
+	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
+		struct dentry *parent = dget_parent(path->dentry);
+		dput(path->dentry);
+		path->dentry = parent;
+		exp = exp_get_by_name(cd, clp, path, NULL);
+	}
+	dput(path->dentry);
+	path->dentry = saved;
+	return exp;
+}
+
+
+
+/*
+ * Obtain the root fh on behalf of a client.
+ * This could be done in user space, but I feel that it adds some safety
+ * since its harder to fool a kernel module than a user space program.
+ */
+int
+exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
+	   struct knfsd_fh *f, int maxsize)
+{
+	struct svc_export	*exp;
+	struct path		path;
+	struct inode		*inode __maybe_unused;
+	struct svc_fh		fh;
+	int			err;
+	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
+	struct cache_detail	*cd = nn->svc_export_cache;
+
+	err = -EPERM;
+	/* NB: we probably ought to check that it's NUL-terminated */
+	if (kern_path(name, 0, &path)) {
+		printk("nfsd: exp_rootfh path not found %s", name);
+		return err;
+	}
+	inode = d_inode(path.dentry);
+
+	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%llu)\n",
+		 name, path.dentry, clp->name,
+		 inode->i_sb->s_id, inode->i_ino);
+	exp = exp_parent(cd, clp, &path);
+	if (IS_ERR(exp)) {
+		err = PTR_ERR(exp);
+		goto out;
+	}
+
+	/*
+	 * fh must be initialized before calling fh_compose
+	 */
+	fh_init(&fh, maxsize);
+	if (fh_compose(&fh, exp, path.dentry, NULL))
+		err = -EINVAL;
+	else
+		err = 0;
+	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
+	fh_put(&fh);
+	exp_put(exp);
+out:
+	path_put(&path);
+	return err;
+}
+
+static struct svc_export *exp_find(struct cache_detail *cd,
+				   struct auth_domain *clp, int fsid_type,
+				   u32 *fsidv, struct cache_req *reqp)
+{
+	struct svc_export *exp;
+	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
+	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
+	if (IS_ERR(ek))
+		return ERR_CAST(ek);
+
+	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
+	cache_put(&ek->h, nn->svc_expkey_cache);
+
+	if (IS_ERR(exp))
+		return ERR_CAST(exp);
+	return exp;
+}
+
+/**
+ * check_xprtsec_policy - check if access to export is allowed by the
+ *			  xprtsec policy
+ * @exp: svc_export that is being accessed.
+ * @rqstp: svc_rqst attempting to access @exp.
+ *
+ * Helper function for check_nfsd_access().  Note that callers should be
+ * using check_nfsd_access() instead of calling this function directly.  The
+ * one exception is __fh_verify() since it has logic that may result in one
+ * or both of the helpers being skipped.
+ *
+ * Return values:
+ *   %nfs_ok if access is granted, or
+ *   %nfserr_wrongsec if access is denied
+ */
+__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp)
+{
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_NONE) {
+		if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags))
+			return nfs_ok;
+	}
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_TLS) {
+		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
+		    !test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
+			return nfs_ok;
+	}
+	if (exp->ex_xprtsec_modes & NFSEXP_XPRTSEC_MTLS) {
+		if (test_bit(XPT_TLS_SESSION, &xprt->xpt_flags) &&
+		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
+			return nfs_ok;
+	}
+	return nfserr_wrongsec;
+}
+
+/**
+ * check_security_flavor - check if access to export is allowed by the
+ *			   security flavor
+ * @exp: svc_export that is being accessed.
+ * @rqstp: svc_rqst attempting to access @exp.
+ * @may_bypass_gss: reduce strictness of authorization check
+ *
+ * Helper function for check_nfsd_access().  Note that callers should be
+ * using check_nfsd_access() instead of calling this function directly.  The
+ * one exception is __fh_verify() since it has logic that may result in one
+ * or both of the helpers being skipped.
+ *
+ * Return values:
+ *   %nfs_ok if access is granted, or
+ *   %nfserr_wrongsec if access is denied
+ */
+__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
+			     bool may_bypass_gss)
+{
+	struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
+
+	/* legacy gss-only clients are always OK: */
+	if (exp->ex_client == rqstp->rq_gssclient)
+		return nfs_ok;
+	/* ip-address based client; check sec= export option: */
+	for (f = exp->ex_flavors; f < end; f++) {
+		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
+			return nfs_ok;
+	}
+	/* defaults in absence of sec= options: */
+	if (exp->ex_nflavors == 0) {
+		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
+		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
+			return nfs_ok;
+	}
+
+	/* If the compound op contains a spo_must_allowed op,
+	 * it will be sent with integrity/protection which
+	 * will have to be expressly allowed on mounts that
+	 * don't support it
+	 */
+
+	if (nfsd4_spo_must_allow(rqstp))
+		return nfs_ok;
+
+	/* Some calls may be processed without authentication
+	 * on GSS exports. For example NFS2/3 calls on root
+	 * directory, see section 2.3.2 of rfc 2623.
+	 * For "may_bypass_gss" check that export has really
+	 * enabled some flavor with authentication (GSS or any
+	 * other) and also check that the used auth flavor is
+	 * without authentication (none or sys).
+	 */
+	if (may_bypass_gss && (
+	     rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
+	     rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)) {
+		for (f = exp->ex_flavors; f < end; f++) {
+			if (f->pseudoflavor >= RPC_AUTH_DES)
+				return 0;
+		}
+	}
+
+	return nfserr_wrongsec;
+}
+
+/**
+ * check_nfsd_access - check if access to export is allowed.
+ * @exp: svc_export that is being accessed.
+ * @rqstp: svc_rqst attempting to access @exp.
+ * @may_bypass_gss: reduce strictness of authorization check
+ *
+ * Return values:
+ *   %nfs_ok if access is granted, or
+ *   %nfserr_wrongsec if access is denied
+ */
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
+			 bool may_bypass_gss)
+{
+	__be32 status;
+
+	status = check_xprtsec_policy(exp, rqstp);
+	if (status != nfs_ok)
+		return status;
+	return check_security_flavor(exp, rqstp, may_bypass_gss);
+}
+
+/*
+ * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
+ * auth_unix client) if it's available and has secinfo information;
+ * otherwise, will try to use rq_gssclient.
+ *
+ * Called from functions that handle requests; functions that do work on
+ * behalf of mountd are passed a single client name to use, and should
+ * use exp_get_by_name() or exp_find().
+ */
+struct svc_export *
+rqst_exp_get_by_name(struct svc_rqst *rqstp, const struct path *path)
+{
+	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (rqstp->rq_client == NULL)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
+	if (PTR_ERR(exp) == -ENOENT)
+		goto gss;
+	if (IS_ERR(exp))
+		return exp;
+	/* If it has secinfo, assume there are no gss/... clients */
+	if (exp->ex_nflavors > 0)
+		return exp;
+gss:
+	/* Otherwise, try falling back on gss client */
+	if (rqstp->rq_gssclient == NULL)
+		return exp;
+	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
+	if (PTR_ERR(gssexp) == -ENOENT)
+		return exp;
+	if (!IS_ERR(exp))
+		exp_put(exp);
+	return gssexp;
+}
+
+/**
+ * rqst_exp_find - Find an svc_export in the context of a rqst or similar
+ * @reqp:	The handle to be used to suspend the request if a cache-upcall is needed
+ *		If NULL, missing in-cache information will result in failure.
+ * @net:	The network namespace in which the request exists
+ * @cl:		default auth_domain to use for looking up the export
+ * @gsscl:	an alternate auth_domain defined using deprecated gss/krb5 format.
+ * @fsid_type:	The type of fsid to look for
+ * @fsidv:	The actual fsid to look up in the context of either client.
+ *
+ * Perform a lookup for @cl/@fsidv in the given @net for an export.  If
+ * none found and @gsscl specified, repeat the lookup.
+ *
+ * Returns an export, or an error pointer.
+ */
+struct svc_export *
+rqst_exp_find(struct cache_req *reqp, struct net *net,
+	      struct auth_domain *cl, struct auth_domain *gsscl,
+	      int fsid_type, u32 *fsidv)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (!cl)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_find(cd, cl, fsid_type, fsidv, reqp);
+	if (PTR_ERR(exp) == -ENOENT)
+		goto gss;
+	if (IS_ERR(exp))
+		return exp;
+	/* If it has secinfo, assume there are no gss/... clients */
+	if (exp->ex_nflavors > 0)
+		return exp;
+gss:
+	/* Otherwise, try falling back on gss client */
+	if (!gsscl)
+		return exp;
+	gssexp = exp_find(cd, gsscl, fsid_type, fsidv, reqp);
+	if (PTR_ERR(gssexp) == -ENOENT)
+		return exp;
+	if (!IS_ERR(exp))
+		exp_put(exp);
+	return gssexp;
+}
+
+struct svc_export *
+rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
+{
+	struct dentry *saved = dget(path->dentry);
+	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
+
+	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
+		struct dentry *parent = dget_parent(path->dentry);
+		dput(path->dentry);
+		path->dentry = parent;
+		exp = rqst_exp_get_by_name(rqstp, path);
+	}
+	dput(path->dentry);
+	path->dentry = saved;
+	return exp;
+}
+
+struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
+{
+	u32 fsidv[2];
+
+	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
+
+	return rqst_exp_find(&rqstp->rq_chandle, SVC_NET(rqstp),
+			     rqstp->rq_client, rqstp->rq_gssclient,
+			     FSID_NUM, fsidv);
+}
+
+/*
+ * Called when we need the filehandle for the root of the pseudofs,
+ * for a given NFSv4 client.   The root is defined to be the
+ * export point with fsid==0
+ */
+__be32
+exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+	struct svc_export *exp;
+	__be32 rv;
+
+	exp = rqst_find_fsidzero_export(rqstp);
+	if (IS_ERR(exp))
+		return nfserrno(PTR_ERR(exp));
+	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
+	exp_put(exp);
+	return rv;
+}
+
+static struct flags {
+	int flag;
+	char *name[2];
+} expflags[] = {
+	{ NFSEXP_READONLY, {"ro", "rw"}},
+	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
+	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
+	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
+	{ NFSEXP_ASYNC, {"async", "sync"}},
+	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
+	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
+	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
+	{ NFSEXP_SIGN_FH, {"sign_fh", ""}},
+	{ NFSEXP_NOHIDE, {"nohide", ""}},
+	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
+	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
+	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
+	{ NFSEXP_V4ROOT, {"v4root", ""}},
+	{ NFSEXP_PNFS, {"pnfs", ""}},
+	{ 0, {"", ""}}
+};
+
+static void show_expflags(struct seq_file *m, int flags, int mask)
+{
+	struct flags *flg;
+	int state, first = 0;
+
+	for (flg = expflags; flg->flag; flg++) {
+		if (flg->flag & ~mask)
+			continue;
+		state = (flg->flag & flags) ? 0 : 1;
+		if (*flg->name[state])
+			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
+	}
+}
+
+static void show_secinfo_flags(struct seq_file *m, int flags)
+{
+	seq_printf(m, ",");
+	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
+}
+
+static bool secinfo_flags_equal(int f, int g)
+{
+	f &= NFSEXP_SECINFO_FLAGS;
+	g &= NFSEXP_SECINFO_FLAGS;
+	return f == g;
+}
+
+static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
+{
+	int flags;
+
+	flags = (*fp)->flags;
+	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
+	(*fp)++;
+	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
+		seq_printf(m, ":%d", (*fp)->pseudoflavor);
+		(*fp)++;
+	}
+	return flags;
+}
+
+static void show_secinfo(struct seq_file *m, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+	int flags;
+
+	if (exp->ex_nflavors == 0)
+		return;
+	f = exp->ex_flavors;
+	flags = show_secinfo_run(m, &f, end);
+	if (!secinfo_flags_equal(flags, exp->ex_flags))
+		show_secinfo_flags(m, flags);
+	while (f != end) {
+		flags = show_secinfo_run(m, &f, end);
+		show_secinfo_flags(m, flags);
+	}
+}
+
+static void exp_flags(struct seq_file *m, int flag, int fsid,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
+{
+	struct user_namespace *userns = m->file->f_cred->user_ns;
+
+	show_expflags(m, flag, NFSEXP_ALLFLAGS);
+	if (flag & NFSEXP_FSID)
+		seq_printf(m, ",fsid=%d", fsid);
+	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
+	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
+		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
+	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
+	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
+		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
+	if (fsloc && fsloc->locations_count > 0) {
+		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
+		int i;
+
+		seq_printf(m, ",%s=", loctype);
+		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
+		seq_putc(m, '@');
+		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
+		for (i = 1; i < fsloc->locations_count; i++) {
+			seq_putc(m, ';');
+			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
+			seq_putc(m, '@');
+			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
+		}
+	}
+}
+
+static int e_show(struct seq_file *m, void *p)
+{
+	struct cache_head *cp = p;
+	struct svc_export *exp = container_of(cp, struct svc_export, h);
+	struct cache_detail *cd = m->private;
+	bool export_stats = is_export_stats_file(m);
+
+	if (p == SEQ_START_TOKEN) {
+		seq_puts(m, "# Version 1.1\n");
+		if (export_stats)
+			seq_puts(m, "# Path Client Start-time\n#\tStats\n");
+		else
+			seq_puts(m, "# Path Client(Flags) # IPs\n");
+		return 0;
+	}
+
+	if (cache_check_rcu(cd, &exp->h, NULL))
+		return 0;
+
+	return svc_export_show(m, cd, cp);
+}
+
+const struct seq_operations nfs_exports_op = {
+	.start	= cache_seq_start_rcu,
+	.next	= cache_seq_next_rcu,
+	.stop	= cache_seq_stop_rcu,
+	.show	= e_show,
+};
+
+/*
+ * Initialize the exports module.
+ */
+int
+nfsd_export_init(struct net *net)
+{
+	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
+
+	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
+	if (IS_ERR(nn->svc_export_cache))
+		return PTR_ERR(nn->svc_export_cache);
+	rv = cache_register_net(nn->svc_export_cache, net);
+	if (rv)
+		goto destroy_export_cache;
+
+	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
+	if (IS_ERR(nn->svc_expkey_cache)) {
+		rv = PTR_ERR(nn->svc_expkey_cache);
+		goto unregister_export_cache;
+	}
+	rv = cache_register_net(nn->svc_expkey_cache, net);
+	if (rv)
+		goto destroy_expkey_cache;
+	return 0;
+
+destroy_expkey_cache:
+	cache_destroy_net(nn->svc_expkey_cache, net);
+unregister_export_cache:
+	cache_unregister_net(nn->svc_export_cache, net);
+destroy_export_cache:
+	cache_destroy_net(nn->svc_export_cache, net);
+	return rv;
+}
+
+/*
+ * Flush exports table - called when last nfsd thread is killed
+ */
+void
+nfsd_export_flush(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_purge(nn->svc_expkey_cache);
+	cache_purge(nn->svc_export_cache);
+}
+
+/*
+ * Shutdown the exports module.
+ */
+void
+nfsd_export_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
+
+	cache_unregister_net(nn->svc_expkey_cache, net);
+	cache_unregister_net(nn->svc_export_cache, net);
+	cache_destroy_net(nn->svc_expkey_cache, net);
+	cache_destroy_net(nn->svc_export_cache, net);
+	svcauth_unix_purge(net);
+
+	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
+}
diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h
new file mode 100644
index 000000000..d2b09cd76
--- /dev/null
+++ b/fs/nfsd/export.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+#ifndef NFSD_EXPORT_H
+#define NFSD_EXPORT_H
+
+#include <linux/sunrpc/cache.h>
+#include <linux/percpu_counter.h>
+#include <uapi/linux/nfsd/export.h>
+#include <linux/nfs4.h>
+
+struct knfsd_fh;
+struct svc_fh;
+struct svc_rqst;
+
+/*
+ * FS Locations
+ */
+
+#define MAX_FS_LOCATIONS	128
+
+struct nfsd4_fs_location {
+	char *hosts; /* colon separated list of hosts */
+	char *path;  /* slash separated list of path components */
+};
+
+struct nfsd4_fs_locations {
+	uint32_t locations_count;
+	struct nfsd4_fs_location *locations;
+/* If we're not actually serving this data ourselves (only providing a
+ * list of replicas that do serve it) then we set "migrated": */
+	int migrated;
+};
+
+/*
+ * We keep an array of pseudoflavors with the export, in order from most
+ * to least preferred.  For the foreseeable future, we don't expect more
+ * than the eight pseudoflavors null, unix, krb5, krb5i, krb5p, skpm3,
+ * spkm3i, and spkm3p (and using all 8 at once should be rare).
+ */
+#define MAX_SECINFO_LIST	8
+#define EX_UUID_LEN		16
+
+struct exp_flavor_info {
+	u32	pseudoflavor;
+	u32	flags;
+};
+
+/* Per-export stats */
+enum {
+	EXP_STATS_FH_STALE,
+	EXP_STATS_IO_READ,
+	EXP_STATS_IO_WRITE,
+	EXP_STATS_COUNTERS_NUM
+};
+
+struct export_stats {
+	time64_t		start_time;
+	struct percpu_counter	counter[EXP_STATS_COUNTERS_NUM];
+};
+
+struct svc_export {
+	struct cache_head	h;
+	struct auth_domain *	ex_client;
+	int			ex_flags;
+	int			ex_fsid;
+	struct path		ex_path;
+	kuid_t			ex_anon_uid;
+	kgid_t			ex_anon_gid;
+	unsigned char *		ex_uuid; /* 16 byte fsid */
+	struct nfsd4_fs_locations ex_fslocs;
+	uint32_t		ex_nflavors;
+	struct exp_flavor_info	ex_flavors[MAX_SECINFO_LIST];
+	u32			ex_layout_types;
+	struct nfsd4_deviceid_map *ex_devid_map;
+	struct cache_detail	*cd;
+	struct rcu_head		ex_rcu;
+	unsigned long		ex_xprtsec_modes;
+	struct export_stats	*ex_stats;
+};
+
+/* an "export key" (expkey) maps a filehandlefragement to an
+ * svc_export for a given client.  There can be several per export,
+ * for the different fsid types.
+ */
+struct svc_expkey {
+	struct cache_head	h;
+
+	struct auth_domain *	ek_client;
+	u8			ek_fsidtype;
+	u32			ek_fsid[6];
+
+	struct path		ek_path;
+	struct rcu_head		ek_rcu;
+};
+
+#define EX_ISSYNC(exp)		(!((exp)->ex_flags & NFSEXP_ASYNC))
+#define EX_NOHIDE(exp)		((exp)->ex_flags & NFSEXP_NOHIDE)
+#define EX_WGATHER(exp)		((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
+
+struct svc_cred;
+int nfsexp_flags(struct svc_cred *cred, struct svc_export *exp);
+__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp);
+__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
+			     bool may_bypass_gss);
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
+			 bool may_bypass_gss);
+
+/*
+ * Function declarations
+ */
+int			nfsd_export_init(struct net *);
+void			nfsd_export_shutdown(struct net *);
+void			nfsd_export_flush(struct net *);
+struct svc_export *	rqst_exp_get_by_name(struct svc_rqst *,
+					     const struct path *);
+struct svc_export *	rqst_exp_parent(struct svc_rqst *,
+					struct path *);
+struct svc_export *	rqst_find_fsidzero_export(struct svc_rqst *);
+int			exp_rootfh(struct net *, struct auth_domain *,
+					char *path, struct knfsd_fh *, int maxsize);
+__be32			exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
+
+static inline void exp_put(struct svc_export *exp)
+{
+	cache_put(&exp->h, exp->cd);
+}
+
+static inline struct svc_export *exp_get(struct svc_export *exp)
+{
+	cache_get(&exp->h);
+	return exp;
+}
+struct svc_export *rqst_exp_find(struct cache_req *reqp, struct net *net,
+				 struct auth_domain *cl, struct auth_domain *gsscl,
+				 int fsid_type, u32 *fsidv);
+
+#endif /* NFSD_EXPORT_H */
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
new file mode 100644
index 000000000..b9548eb17
--- /dev/null
+++ b/fs/nfsd/filecache.c
@@ -0,0 +1,1565 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The NFSD open file cache.
+ *
+ * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com>
+ *
+ * An nfsd_file object is a per-file collection of open state that binds
+ * together:
+ *   - a struct file *
+ *   - a user credential
+ *   - a network namespace
+ *   - a read-ahead context
+ *   - monitoring for writeback errors
+ *
+ * nfsd_file objects are reference-counted. Consumers acquire a new
+ * object via the nfsd_file_acquire API. They manage their interest in
+ * the acquired object, and hence the object's reference count, via
+ * nfsd_file_get and nfsd_file_put. There are two varieties of nfsd_file
+ * object:
+ *
+ *  * non-garbage-collected: When a consumer wants to precisely control
+ *    the lifetime of a file's open state, it acquires a non-garbage-
+ *    collected nfsd_file. The final nfsd_file_put releases the open
+ *    state immediately.
+ *
+ *  * garbage-collected: When a consumer does not control the lifetime
+ *    of open state, it acquires a garbage-collected nfsd_file. The
+ *    final nfsd_file_put allows the open state to linger for a period
+ *    during which it may be re-used.
+ */
+
+#include <linux/hash.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/list_lru.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/fsnotify.h>
+#include <linux/seq_file.h>
+#include <linux/rhashtable.h>
+#include <linux/nfslocalio.h>
+
+#include "vfs.h"
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "netns.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSD_LAUNDRETTE_DELAY		     (2 * HZ)
+
+#define NFSD_FILE_CACHE_UP		     (0)
+
+/* We only care about NFSD_MAY_READ/WRITE for this cache */
+#define NFSD_FILE_MAY_MASK	(NFSD_MAY_READ|NFSD_MAY_WRITE|NFSD_MAY_LOCALIO)
+
+/* If the shrinker runs between calls to list_lru_walk_node() in
+ * nfsd_file_gc(), the "remaining" count will be wrong.  This could
+ * result in premature freeing of some files.  This may not matter much
+ * but is easy to fix with this spinlock which temporarily disables
+ * the shrinker.
+ *
+ * It also serializes callers of nfsd_file_dispose_list_delayed()
+ * against per-net shutdown.
+ */
+static DEFINE_SPINLOCK(nfsd_gc_lock);
+
+static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_allocations);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_releases);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_total_age);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_evictions);
+
+static struct kmem_cache		*nfsd_file_slab;
+static struct kmem_cache		*nfsd_file_mark_slab;
+static struct list_lru			nfsd_file_lru;
+static unsigned long			nfsd_file_flags;
+static struct fsnotify_group		*nfsd_file_fsnotify_group;
+static struct fsnotify_group		*nfsd_dir_fsnotify_group;
+static struct delayed_work		nfsd_filecache_laundrette;
+static struct rhltable			nfsd_file_rhltable
+						____cacheline_aligned_in_smp;
+
+static bool
+nfsd_match_cred(const struct cred *c1, const struct cred *c2)
+{
+	int i;
+
+	if (!uid_eq(c1->fsuid, c2->fsuid))
+		return false;
+	if (!gid_eq(c1->fsgid, c2->fsgid))
+		return false;
+	if (c1->group_info == NULL || c2->group_info == NULL)
+		return c1->group_info == c2->group_info;
+	if (c1->group_info->ngroups != c2->group_info->ngroups)
+		return false;
+	for (i = 0; i < c1->group_info->ngroups; i++) {
+		if (!gid_eq(c1->group_info->gid[i], c2->group_info->gid[i]))
+			return false;
+	}
+	return true;
+}
+
+static const struct rhashtable_params nfsd_file_rhash_params = {
+	.key_len		= sizeof_field(struct nfsd_file, nf_inode),
+	.key_offset		= offsetof(struct nfsd_file, nf_inode),
+	.head_offset		= offsetof(struct nfsd_file, nf_rlist),
+
+	/*
+	 * Start with a single page hash table to reduce resizing churn
+	 * on light workloads.
+	 */
+	.min_size		= 256,
+	.automatic_shrinking	= true,
+};
+
+static void
+nfsd_file_schedule_laundrette(void)
+{
+	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags))
+		queue_delayed_work(system_dfl_wq, &nfsd_filecache_laundrette,
+				   NFSD_LAUNDRETTE_DELAY);
+}
+
+static void
+nfsd_file_slab_free(struct rcu_head *rcu)
+{
+	struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu);
+
+	put_cred(nf->nf_cred);
+	kmem_cache_free(nfsd_file_slab, nf);
+}
+
+static void
+nfsd_file_mark_free(struct fsnotify_mark *mark)
+{
+	struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark,
+						  nfm_mark);
+
+	kmem_cache_free(nfsd_file_mark_slab, nfm);
+}
+
+static struct nfsd_file_mark *
+nfsd_file_mark_get(struct nfsd_file_mark *nfm)
+{
+	if (!refcount_inc_not_zero(&nfm->nfm_ref))
+		return NULL;
+	return nfm;
+}
+
+static void
+nfsd_file_mark_put(struct nfsd_file_mark *nfm)
+{
+	if (refcount_dec_and_test(&nfm->nfm_ref)) {
+		fsnotify_destroy_mark(&nfm->nfm_mark, nfm->nfm_mark.group);
+		fsnotify_put_mark(&nfm->nfm_mark);
+	}
+}
+
+static struct nfsd_file_mark *
+nfsd_file_mark_find_or_create(struct inode *inode)
+{
+	struct nfsd_file_mark	*nfm = NULL, *new;
+	struct fsnotify_group	*group;
+	struct fsnotify_mark	*mark;
+	int			err;
+
+	group = S_ISDIR(inode->i_mode) ? nfsd_dir_fsnotify_group : nfsd_file_fsnotify_group;
+
+	do {
+		fsnotify_group_lock(group);
+		mark = fsnotify_find_inode_mark(inode, group);
+		if (mark) {
+			nfm = nfsd_file_mark_get(container_of(mark,
+						 struct nfsd_file_mark,
+						 nfm_mark));
+			fsnotify_group_unlock(group);
+			if (nfm) {
+				fsnotify_put_mark(mark);
+				break;
+			}
+			/* Avoid soft lockup race with nfsd_file_mark_put() */
+			fsnotify_destroy_mark(mark, group);
+			fsnotify_put_mark(mark);
+		} else {
+			fsnotify_group_unlock(group);
+		}
+
+		/* allocate a new nfm */
+		new = kmem_cache_alloc(nfsd_file_mark_slab, GFP_KERNEL);
+		if (!new)
+			return NULL;
+		fsnotify_init_mark(&new->nfm_mark, group);
+		new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF;
+		refcount_set(&new->nfm_ref, 1);
+		mutex_init(&new->nfm_recalc_mutex);
+
+		err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0);
+
+		/*
+		 * If the add was successful, then return the object.
+		 * Otherwise, we need to put the reference we hold on the
+		 * nfm_mark. The fsnotify code will take a reference and put
+		 * it on failure, so we can't just free it directly. It's also
+		 * not safe to call fsnotify_destroy_mark on it as the
+		 * mark->group will be NULL. Thus, we can't let the nfm_ref
+		 * counter drive the destruction at this point.
+		 */
+		if (likely(!err))
+			nfm = new;
+		else
+			fsnotify_put_mark(&new->nfm_mark);
+	} while (unlikely(err == -EEXIST));
+
+	return nfm;
+}
+
+static struct nfsd_file *
+nfsd_file_alloc(struct net *net, struct inode *inode, unsigned char need,
+		bool want_gc)
+{
+	struct nfsd_file *nf;
+
+	nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL);
+	if (unlikely(!nf))
+		return NULL;
+
+	this_cpu_inc(nfsd_file_allocations);
+	INIT_LIST_HEAD(&nf->nf_lru);
+	INIT_LIST_HEAD(&nf->nf_gc);
+	nf->nf_birthtime = ktime_get();
+	nf->nf_file = NULL;
+	nf->nf_cred = get_current_cred();
+	nf->nf_net = net;
+	nf->nf_flags = want_gc ?
+		BIT(NFSD_FILE_HASHED) | BIT(NFSD_FILE_PENDING) | BIT(NFSD_FILE_GC) :
+		BIT(NFSD_FILE_HASHED) | BIT(NFSD_FILE_PENDING);
+	nf->nf_inode = inode;
+	refcount_set(&nf->nf_ref, 1);
+	nf->nf_may = need;
+	nf->nf_mark = NULL;
+	nf->nf_dio_mem_align = 0;
+	nf->nf_dio_offset_align = 0;
+	nf->nf_dio_read_offset_align = 0;
+	return nf;
+}
+
+/**
+ * nfsd_file_check_write_error - check for writeback errors on a file
+ * @nf: nfsd_file to check for writeback errors
+ *
+ * Check whether a nfsd_file has an unseen error. Reset the write
+ * verifier if so.
+ */
+static void
+nfsd_file_check_write_error(struct nfsd_file *nf)
+{
+	struct file *file = nf->nf_file;
+
+	if ((file->f_mode & FMODE_WRITE) &&
+	    filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)))
+		nfsd_reset_write_verifier(net_generic(nf->nf_net, nfsd_net_id));
+}
+
+static void
+nfsd_file_hash_remove(struct nfsd_file *nf)
+{
+	trace_nfsd_file_unhash(nf);
+	rhltable_remove(&nfsd_file_rhltable, &nf->nf_rlist,
+			nfsd_file_rhash_params);
+}
+
+static bool
+nfsd_file_unhash(struct nfsd_file *nf)
+{
+	if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		nfsd_file_hash_remove(nf);
+		return true;
+	}
+	return false;
+}
+
+static void
+nfsd_file_free(struct nfsd_file *nf)
+{
+	s64 age = ktime_to_ms(ktime_sub(ktime_get(), nf->nf_birthtime));
+
+	trace_nfsd_file_free(nf);
+
+	this_cpu_inc(nfsd_file_releases);
+	this_cpu_add(nfsd_file_total_age, age);
+
+	nfsd_file_unhash(nf);
+	if (nf->nf_mark)
+		nfsd_file_mark_put(nf->nf_mark);
+	if (nf->nf_file) {
+		nfsd_file_check_write_error(nf);
+		nfsd_filp_close(nf->nf_file);
+	}
+
+	/*
+	 * If this item is still linked via nf_lru, that's a bug.
+	 * WARN and leak it to preserve system stability.
+	 */
+	if (WARN_ON_ONCE(!list_empty(&nf->nf_lru)))
+		return;
+
+	call_rcu(&nf->nf_rcu, nfsd_file_slab_free);
+}
+
+static bool
+nfsd_file_check_writeback(struct nfsd_file *nf)
+{
+	struct file *file = nf->nf_file;
+	struct address_space *mapping;
+
+	/* File not open for write? */
+	if (!(file->f_mode & FMODE_WRITE))
+		return false;
+
+	/*
+	 * Some filesystems (e.g. NFS) flush all dirty data on close.
+	 * On others, there is no need to wait for writeback.
+	 */
+	if (!(file_inode(file)->i_sb->s_export_op->flags & EXPORT_OP_FLUSH_ON_CLOSE))
+		return false;
+
+	mapping = file->f_mapping;
+	return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) ||
+		mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK);
+}
+
+static void nfsd_file_lru_add(struct nfsd_file *nf)
+{
+	refcount_inc(&nf->nf_ref);
+	if (list_lru_add_obj(&nfsd_file_lru, &nf->nf_lru))
+		trace_nfsd_file_lru_add(nf);
+	else {
+		refcount_dec(&nf->nf_ref);
+		WARN_ON_ONCE(1);
+		return;
+	}
+	nfsd_file_schedule_laundrette();
+}
+
+static bool nfsd_file_lru_remove(struct nfsd_file *nf)
+{
+	if (list_lru_del_obj(&nfsd_file_lru, &nf->nf_lru)) {
+		trace_nfsd_file_lru_del(nf);
+		return true;
+	}
+	return false;
+}
+
+struct nfsd_file *
+nfsd_file_get(struct nfsd_file *nf)
+{
+	if (nf && refcount_inc_not_zero(&nf->nf_ref))
+		return nf;
+	return NULL;
+}
+
+/**
+ * nfsd_file_put - put the reference to a nfsd_file
+ * @nf: nfsd_file of which to put the reference
+ *
+ * Put a reference to a nfsd_file. In the non-GC case, we just put the
+ * reference immediately. In the GC case, if the reference would be
+ * the last one, the put it on the LRU instead to be cleaned up later.
+ */
+void
+nfsd_file_put(struct nfsd_file *nf)
+{
+	might_sleep();
+	trace_nfsd_file_put(nf);
+
+	if (test_bit(NFSD_FILE_GC, &nf->nf_flags) &&
+	    test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
+		set_bit(NFSD_FILE_RECENT, &nf->nf_flags);
+	}
+
+	if (refcount_dec_and_test(&nf->nf_ref))
+		nfsd_file_free(nf);
+}
+
+/**
+ * nfsd_file_put_local - put nfsd_file reference and arm nfsd_net_put in caller
+ * @pnf: nfsd_file of which to put the reference
+ *
+ * First save the associated net to return to caller, then put
+ * the reference of the nfsd_file.
+ */
+struct net *
+nfsd_file_put_local(struct nfsd_file __rcu **pnf)
+{
+	struct nfsd_file *nf;
+	struct net *net = NULL;
+
+	nf = unrcu_pointer(xchg(pnf, NULL));
+	if (nf) {
+		net = nf->nf_net;
+		nfsd_file_put(nf);
+	}
+	return net;
+}
+
+/**
+ * nfsd_file_file - get the backing file of an nfsd_file
+ * @nf: nfsd_file of which to access the backing file.
+ *
+ * Return backing file for @nf.
+ */
+struct file *
+nfsd_file_file(struct nfsd_file *nf)
+{
+	return nf->nf_file;
+}
+
+static void
+nfsd_file_dispose_list(struct list_head *dispose)
+{
+	struct nfsd_file *nf;
+
+	while (!list_empty(dispose)) {
+		nf = list_first_entry(dispose, struct nfsd_file, nf_gc);
+		list_del_init(&nf->nf_gc);
+		nfsd_file_free(nf);
+	}
+}
+
+/**
+ * nfsd_file_dispose_list_delayed - queue dead files for nfsd thread disposal
+ * @dispose: list of nfsd_files to be disposed
+ *
+ * Transfers each file to the dispose list in its nfsd_net and wakes an nfsd
+ * thread to do the actual close.  This keeps the cost of fput() in the nfsd
+ * threads rather than in the shrinker or GC worker.
+ *
+ * All callers must hold nfsd_gc_lock, so that nfsd_file_cache_shutdown_net()
+ * can synchronize against them before draining the per-net dispose list.
+ * This guarantees nf_net is still live when we call net_generic().
+ */
+static void
+nfsd_file_dispose_list_delayed(struct list_head *dispose)
+{
+	lockdep_assert_held(&nfsd_gc_lock);
+
+	while (!list_empty(dispose)) {
+		struct nfsd_file *nf = list_first_entry(dispose,
+						struct nfsd_file, nf_gc);
+		struct nfsd_net *nn = net_generic(nf->nf_net, nfsd_net_id);
+		struct svc_serv *serv;
+
+		spin_lock(&nn->fcache_dispose_lock);
+		list_move_tail(&nf->nf_gc, &nn->fcache_dispose_list);
+		spin_unlock(&nn->fcache_dispose_lock);
+
+		/*
+		 * The filecache laundrette is shut down after the
+		 * nn->nfsd_serv pointer is cleared, but before the
+		 * svc_serv is freed.
+		 */
+		serv = nn->nfsd_serv;
+		if (serv)
+			svc_wake_up(serv);
+	}
+}
+
+/**
+ * nfsd_file_net_dispose - deal with nfsd_files waiting to be disposed.
+ * @nn: nfsd_net in which to find files to be disposed.
+ *
+ * When files held open for nfsv3 are removed from the filecache, whether
+ * due to memory pressure or garbage collection, they are queued to
+ * a per-net-ns queue.  This function completes the disposal, either
+ * directly or by waking another nfsd thread to help with the work.
+ */
+void nfsd_file_net_dispose(struct nfsd_net *nn)
+{
+	if (!list_empty(&nn->fcache_dispose_list)) {
+		LIST_HEAD(dispose);
+		int i;
+
+		spin_lock(&nn->fcache_dispose_lock);
+		for (i = 0; i < 8 && !list_empty(&nn->fcache_dispose_list); i++)
+			list_move(nn->fcache_dispose_list.next, &dispose);
+		spin_unlock(&nn->fcache_dispose_lock);
+		if (!list_empty(&nn->fcache_dispose_list)) {
+			/*
+			 * Wake up another thread to share the work
+			 * *before* doing any actual disposing.
+			 *
+			 * The filecache laundrette is shut down after
+			 * the nn->nfsd_serv pointer is cleared, but
+			 * before the svc_serv is freed.
+			 */
+			struct svc_serv *serv = nn->nfsd_serv;
+
+			if (serv)
+				svc_wake_up(serv);
+		}
+		nfsd_file_dispose_list(&dispose);
+	}
+}
+
+/**
+ * nfsd_file_lru_cb - Examine an entry on the LRU list
+ * @item: LRU entry to examine
+ * @lru: controlling LRU
+ * @arg: dispose list
+ *
+ * Return values:
+ *   %LRU_REMOVED: @item was removed from the LRU
+ *   %LRU_ROTATE: @item is to be moved to the LRU tail
+ *   %LRU_SKIP: @item cannot be evicted
+ */
+static enum lru_status
+nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
+		 void *arg)
+{
+	struct list_head *head = arg;
+	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);
+
+	/* We should only be dealing with GC entries here */
+	WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags));
+
+	/*
+	 * Don't throw out files that are still undergoing I/O or
+	 * that have uncleared errors pending.
+	 */
+	if (nfsd_file_check_writeback(nf)) {
+		trace_nfsd_file_gc_writeback(nf);
+		return LRU_SKIP;
+	}
+
+	/* If it was recently added to the list, skip it */
+	if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) {
+		trace_nfsd_file_gc_referenced(nf);
+		return LRU_ROTATE;
+	}
+
+	/*
+	 * Put the reference held on behalf of the LRU if it is the last
+	 * reference, else rotate.
+	 */
+	if (!refcount_dec_if_one(&nf->nf_ref)) {
+		trace_nfsd_file_gc_in_use(nf);
+		return LRU_ROTATE;
+	}
+
+	/* Refcount went to zero. Unhash it and queue it to the dispose list */
+	nfsd_file_unhash(nf);
+	list_lru_isolate(lru, &nf->nf_lru);
+	list_add(&nf->nf_gc, head);
+	this_cpu_inc(nfsd_file_evictions);
+	trace_nfsd_file_gc_disposed(nf);
+	return LRU_REMOVED;
+}
+
+static enum lru_status
+nfsd_file_gc_cb(struct list_head *item, struct list_lru_one *lru,
+		 void *arg)
+{
+	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);
+
+	if (test_and_clear_bit(NFSD_FILE_RECENT, &nf->nf_flags)) {
+		/*
+		 * "REFERENCED" really means "should be at the end of the
+		 * LRU. As we are putting it there we can clear the flag.
+		 */
+		clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
+		trace_nfsd_file_gc_aged(nf);
+		return LRU_ROTATE;
+	}
+	return nfsd_file_lru_cb(item, lru, arg);
+}
+
+static void
+nfsd_file_gc(void)
+{
+	unsigned long ret = 0;
+	LIST_HEAD(dispose);
+	int nid;
+
+	spin_lock(&nfsd_gc_lock);
+	for_each_node_state(nid, N_NORMAL_MEMORY) {
+		unsigned long remaining = list_lru_count_node(&nfsd_file_lru, nid);
+
+		while (remaining > 0) {
+			unsigned long nr = min(remaining, NFSD_FILE_GC_BATCH);
+
+			remaining -= nr;
+			ret += list_lru_walk_node(&nfsd_file_lru, nid, nfsd_file_gc_cb,
+						  &dispose, &nr);
+			if (nr)
+				/* walk aborted early */
+				remaining = 0;
+		}
+	}
+	nfsd_file_dispose_list_delayed(&dispose);
+	spin_unlock(&nfsd_gc_lock);
+	trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru));
+}
+
+static void
+nfsd_file_gc_worker(struct work_struct *work)
+{
+	if (list_lru_count(&nfsd_file_lru))
+		nfsd_file_gc();
+	nfsd_file_schedule_laundrette();
+}
+
+static unsigned long
+nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc)
+{
+	return list_lru_count(&nfsd_file_lru);
+}
+
+static unsigned long
+nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
+{
+	LIST_HEAD(dispose);
+	unsigned long ret;
+
+	if (!spin_trylock(&nfsd_gc_lock))
+		return SHRINK_STOP;
+
+	ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
+				   nfsd_file_lru_cb, &dispose);
+	nfsd_file_dispose_list_delayed(&dispose);
+	spin_unlock(&nfsd_gc_lock);
+	trace_nfsd_file_shrinker_removed(ret, list_lru_count(&nfsd_file_lru));
+	return ret;
+}
+
+static struct shrinker *nfsd_file_shrinker;
+
+/**
+ * nfsd_file_cond_queue - conditionally unhash and queue a nfsd_file
+ * @nf: nfsd_file to attempt to queue
+ * @dispose: private list to queue successfully-put objects
+ *
+ * Unhash an nfsd_file, try to get a reference to it, and then put that
+ * reference. If it's the last reference, queue it to the dispose list.
+ */
+static void
+nfsd_file_cond_queue(struct nfsd_file *nf, struct list_head *dispose)
+	__must_hold(RCU)
+{
+	int decrement = 1;
+
+	/* If we raced with someone else unhashing, ignore it */
+	if (!nfsd_file_unhash(nf))
+		return;
+
+	/* If we can't get a reference, ignore it */
+	if (!nfsd_file_get(nf))
+		return;
+
+	/* Extra decrement if we remove from the LRU */
+	if (nfsd_file_lru_remove(nf))
+		++decrement;
+
+	/* If refcount goes to 0, then put on the dispose list */
+	if (refcount_sub_and_test(decrement, &nf->nf_ref)) {
+		list_add(&nf->nf_gc, dispose);
+		trace_nfsd_file_closing(nf);
+	}
+}
+
+/**
+ * nfsd_file_queue_for_close: try to close out any open nfsd_files for an inode
+ * @inode:   inode on which to close out nfsd_files
+ * @dispose: list on which to gather nfsd_files to close out
+ *
+ * An nfsd_file represents a struct file being held open on behalf of nfsd.
+ * An open file however can block other activity (such as leases), or cause
+ * undesirable behavior (e.g. spurious silly-renames when reexporting NFS).
+ *
+ * This function is intended to find open nfsd_files when this sort of
+ * conflicting access occurs and then attempt to close those files out.
+ *
+ * Populates the dispose list with entries that have already had their
+ * refcounts go to zero. The actual free of an nfsd_file can be expensive,
+ * so we leave it up to the caller whether it wants to wait or not.
+ */
+static void
+nfsd_file_queue_for_close(struct inode *inode, struct list_head *dispose)
+{
+	struct rhlist_head *tmp, *list;
+	struct nfsd_file *nf;
+
+	rcu_read_lock();
+	list = rhltable_lookup(&nfsd_file_rhltable, &inode,
+			       nfsd_file_rhash_params);
+	rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist) {
+		if (!test_bit(NFSD_FILE_GC, &nf->nf_flags))
+			continue;
+		nfsd_file_cond_queue(nf, dispose);
+	}
+	rcu_read_unlock();
+}
+
+/**
+ * nfsd_file_close_inode - attempt a deferred close of a nfsd_file
+ * @inode: inode of the file to attempt to remove
+ *
+ * Close out any open nfsd_files that can be reaped for @inode. The
+ * actual freeing is deferred to the nfsd service threads.
+ *
+ * This is used by the fsnotify callbacks and setlease notifier.
+ */
+static void
+nfsd_file_close_inode(struct inode *inode)
+{
+	LIST_HEAD(dispose);
+
+	spin_lock(&nfsd_gc_lock);
+	nfsd_file_queue_for_close(inode, &dispose);
+	nfsd_file_dispose_list_delayed(&dispose);
+	spin_unlock(&nfsd_gc_lock);
+}
+
+/**
+ * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file
+ * @inode: inode of the file to attempt to remove
+ *
+ * Close out any open nfsd_files that can be reaped for @inode. The
+ * nfsd_files are closed out synchronously.
+ *
+ * This is called from nfsd_rename and nfsd_unlink to avoid silly-renames
+ * when reexporting NFS.
+ */
+void
+nfsd_file_close_inode_sync(struct inode *inode)
+{
+	LIST_HEAD(dispose);
+
+	trace_nfsd_file_close(inode);
+
+	nfsd_file_queue_for_close(inode, &dispose);
+	nfsd_file_dispose_list(&dispose);
+}
+
+/**
+ * nfsd_file_close_export - close cached file handles for an export
+ * @net: net namespace in which to operate
+ * @path: export path whose cached files should be closed
+ *
+ * Close out GC-managed nfsd_file entries whose underlying file is on
+ * the same filesystem as, and a descendant of, @path.  nfsd_file
+ * entries do not carry an export reference, so the check uses the
+ * file's dentry ancestry.  False positives (closing a cached handle
+ * that did not originate from the target export) are harmless -- the
+ * handle is simply reopened on the next access.
+ *
+ * Called from the NFSD_CMD_UNLOCK_EXPORT handler before revoking
+ * NFSv4 state, to ensure that cached file handles do not hold the
+ * filesystem busy.
+ */
+void nfsd_file_close_export(struct net *net, const struct path *path)
+{
+	struct rhashtable_iter iter;
+	struct nfsd_file *nf;
+	LIST_HEAD(dispose);
+
+	rhltable_walk_enter(&nfsd_file_rhltable, &iter);
+	do {
+		rhashtable_walk_start(&iter);
+
+		nf = rhashtable_walk_next(&iter);
+		while (!IS_ERR_OR_NULL(nf)) {
+			if (nf->nf_net == net &&
+			    test_bit(NFSD_FILE_GC, &nf->nf_flags) &&
+			    nf->nf_file &&
+			    file_inode(nf->nf_file)->i_sb ==
+					path->dentry->d_sb &&
+			    is_subdir(nf->nf_file->f_path.dentry,
+				      path->dentry))
+				nfsd_file_cond_queue(nf, &dispose);
+			nf = rhashtable_walk_next(&iter);
+		}
+
+		rhashtable_walk_stop(&iter);
+	} while (nf == ERR_PTR(-EAGAIN));
+	rhashtable_walk_exit(&iter);
+
+	nfsd_file_dispose_list(&dispose);
+}
+
+static int
+nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg,
+			    void *data)
+{
+	struct file_lease *fl = data;
+
+	/* Only close files for F_SETLEASE leases */
+	if (fl->c.flc_flags & FL_LEASE)
+		nfsd_file_close_inode(file_inode(fl->c.flc_file));
+	return 0;
+}
+
+static struct notifier_block nfsd_file_lease_notifier = {
+	.notifier_call = nfsd_file_lease_notifier_call,
+};
+
+static int
+nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask,
+				struct inode *inode, struct inode *dir,
+				const struct qstr *name, u32 cookie)
+{
+	if (WARN_ON_ONCE(!inode))
+		return 0;
+
+	trace_nfsd_file_fsnotify_handle_event(inode, mask);
+
+	/* Should be no marks on non-regular files */
+	if (!S_ISREG(inode->i_mode)) {
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+
+	/* don't close files if this was not the last link */
+	if (mask & FS_ATTRIB) {
+		if (inode->i_nlink)
+			return 0;
+	}
+
+	nfsd_file_close_inode(inode);
+	return 0;
+}
+
+#ifdef CONFIG_NFSD_V4
+static int
+nfsd_dir_fsnotify_handle_event(struct fsnotify_group *group, u32 mask,
+			       const void *data, int data_type, struct inode *dir,
+			       const struct qstr *name, u32 cookie,
+			       struct fsnotify_iter_info *iter_info)
+{
+	return nfsd_handle_dir_event(mask, dir, data, data_type, name);
+}
+#else
+static int
+nfsd_dir_fsnotify_handle_event(struct fsnotify_group *group, u32 mask,
+			       const void *data, int data_type, struct inode *dir,
+			       const struct qstr *name, u32 cookie,
+			       struct fsnotify_iter_info *iter_info)
+{
+	return 0;
+}
+#endif
+
+static const struct fsnotify_ops nfsd_file_fsnotify_ops = {
+	.handle_inode_event = nfsd_file_fsnotify_handle_event,
+	.free_mark = nfsd_file_mark_free,
+};
+
+static const struct fsnotify_ops nfsd_dir_fsnotify_ops = {
+	.handle_event = nfsd_dir_fsnotify_handle_event,
+	.free_mark = nfsd_file_mark_free,
+};
+
+int
+nfsd_file_cache_init(void)
+{
+	int ret;
+
+	lockdep_assert_held(&nfsd_mutex);
+	if (test_and_set_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1)
+		return 0;
+
+	ret = rhltable_init(&nfsd_file_rhltable, &nfsd_file_rhash_params);
+	if (ret)
+		goto out;
+
+	ret = -ENOMEM;
+	nfsd_file_slab = KMEM_CACHE(nfsd_file, 0);
+	if (!nfsd_file_slab) {
+		pr_err("nfsd: unable to create nfsd_file_slab\n");
+		goto out_err;
+	}
+
+	nfsd_file_mark_slab = KMEM_CACHE(nfsd_file_mark, 0);
+	if (!nfsd_file_mark_slab) {
+		pr_err("nfsd: unable to create nfsd_file_mark_slab\n");
+		goto out_err;
+	}
+
+	ret = list_lru_init(&nfsd_file_lru);
+	if (ret) {
+		pr_err("nfsd: failed to init nfsd_file_lru: %d\n", ret);
+		goto out_err;
+	}
+
+	nfsd_file_shrinker = shrinker_alloc(0, "nfsd-filecache");
+	if (!nfsd_file_shrinker) {
+		ret = -ENOMEM;
+		pr_err("nfsd: failed to allocate nfsd_file_shrinker\n");
+		goto out_lru;
+	}
+
+	nfsd_file_shrinker->count_objects = nfsd_file_lru_count;
+	nfsd_file_shrinker->scan_objects = nfsd_file_lru_scan;
+	nfsd_file_shrinker->seeks = 1;
+
+	shrinker_register(nfsd_file_shrinker);
+
+	ret = lease_register_notifier(&nfsd_file_lease_notifier);
+	if (ret) {
+		pr_err("nfsd: unable to register lease notifier: %d\n", ret);
+		goto out_shrinker;
+	}
+
+	nfsd_file_fsnotify_group = fsnotify_alloc_group(&nfsd_file_fsnotify_ops, 0);
+	if (IS_ERR(nfsd_file_fsnotify_group)) {
+		pr_err("nfsd: unable to create fsnotify group: %ld\n",
+			PTR_ERR(nfsd_file_fsnotify_group));
+		ret = PTR_ERR(nfsd_file_fsnotify_group);
+		nfsd_file_fsnotify_group = NULL;
+		goto out_notifier;
+	}
+
+	nfsd_dir_fsnotify_group = fsnotify_alloc_group(&nfsd_dir_fsnotify_ops, 0);
+	if (IS_ERR(nfsd_dir_fsnotify_group)) {
+		pr_err("nfsd: unable to create fsnotify group: %ld\n",
+			PTR_ERR(nfsd_dir_fsnotify_group));
+		ret = PTR_ERR(nfsd_dir_fsnotify_group);
+		nfsd_dir_fsnotify_group = NULL;
+		goto out_notify_group;
+	}
+
+	INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker);
+out:
+	if (ret)
+		clear_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags);
+	return ret;
+out_notify_group:
+	fsnotify_put_group(nfsd_file_fsnotify_group);
+	nfsd_file_fsnotify_group = NULL;
+out_notifier:
+	lease_unregister_notifier(&nfsd_file_lease_notifier);
+out_shrinker:
+	shrinker_free(nfsd_file_shrinker);
+out_lru:
+	list_lru_destroy(&nfsd_file_lru);
+out_err:
+	kmem_cache_destroy(nfsd_file_slab);
+	nfsd_file_slab = NULL;
+	kmem_cache_destroy(nfsd_file_mark_slab);
+	nfsd_file_mark_slab = NULL;
+	rhltable_destroy(&nfsd_file_rhltable);
+	goto out;
+}
+
+/**
+ * __nfsd_file_cache_purge: clean out the cache for shutdown
+ * @net: net-namespace to shut down the cache (may be NULL)
+ *
+ * Walk the nfsd_file cache and close out any that match @net. If @net is NULL,
+ * then close out everything. Called when an nfsd instance is being shut down,
+ * and when the exports table is flushed.
+ */
+static void
+__nfsd_file_cache_purge(struct net *net)
+{
+	struct rhashtable_iter iter;
+	struct nfsd_file *nf;
+	LIST_HEAD(dispose);
+
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	if (net) {
+		struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+		nfs_localio_invalidate_clients(&nn->local_clients,
+					       &nn->local_clients_lock);
+	}
+#endif
+
+	rhltable_walk_enter(&nfsd_file_rhltable, &iter);
+	do {
+		rhashtable_walk_start(&iter);
+
+		nf = rhashtable_walk_next(&iter);
+		while (!IS_ERR_OR_NULL(nf)) {
+			if (!net || nf->nf_net == net)
+				nfsd_file_cond_queue(nf, &dispose);
+			nf = rhashtable_walk_next(&iter);
+		}
+
+		rhashtable_walk_stop(&iter);
+	} while (nf == ERR_PTR(-EAGAIN));
+	rhashtable_walk_exit(&iter);
+
+	nfsd_file_dispose_list(&dispose);
+}
+
+int
+nfsd_file_cache_start_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	spin_lock_init(&nn->fcache_dispose_lock);
+	INIT_LIST_HEAD(&nn->fcache_dispose_list);
+	return 0;
+}
+
+/**
+ * nfsd_file_cache_purge - Remove all cache items associated with @net
+ * @net: target net namespace
+ *
+ */
+void
+nfsd_file_cache_purge(struct net *net)
+{
+	lockdep_assert_held(&nfsd_mutex);
+	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1)
+		__nfsd_file_cache_purge(net);
+}
+
+void
+nfsd_file_cache_shutdown_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfsd_file_cache_purge(net);
+	/*
+	 * Ensure any in-progress shrinker, GC, or fsnotify/lease callback
+	 * (all of which hold nfsd_gc_lock while calling
+	 * nfsd_file_dispose_list_delayed()) has fully completed before
+	 * draining the per-net dispose list.
+	 */
+	spin_lock(&nfsd_gc_lock);
+	spin_unlock(&nfsd_gc_lock);
+	nfsd_file_dispose_list(&nn->fcache_dispose_list);
+}
+
+void
+nfsd_file_cache_shutdown(void)
+{
+	int i;
+
+	lockdep_assert_held(&nfsd_mutex);
+	if (test_and_clear_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 0)
+		return;
+
+	lease_unregister_notifier(&nfsd_file_lease_notifier);
+	shrinker_free(nfsd_file_shrinker);
+	/*
+	 * make sure all callers of nfsd_file_lru_cb are done before
+	 * calling nfsd_file_cache_purge
+	 */
+	cancel_delayed_work_sync(&nfsd_filecache_laundrette);
+	__nfsd_file_cache_purge(NULL);
+	list_lru_destroy(&nfsd_file_lru);
+	rcu_barrier();
+	fsnotify_put_group(nfsd_file_fsnotify_group);
+	nfsd_file_fsnotify_group = NULL;
+	fsnotify_put_group(nfsd_dir_fsnotify_group);
+	nfsd_dir_fsnotify_group = NULL;
+	kmem_cache_destroy(nfsd_file_slab);
+	nfsd_file_slab = NULL;
+	fsnotify_wait_marks_destroyed();
+	kmem_cache_destroy(nfsd_file_mark_slab);
+	nfsd_file_mark_slab = NULL;
+	rhltable_destroy(&nfsd_file_rhltable);
+
+	for_each_possible_cpu(i) {
+		per_cpu(nfsd_file_cache_hits, i) = 0;
+		per_cpu(nfsd_file_acquisitions, i) = 0;
+		per_cpu(nfsd_file_allocations, i) = 0;
+		per_cpu(nfsd_file_releases, i) = 0;
+		per_cpu(nfsd_file_total_age, i) = 0;
+		per_cpu(nfsd_file_evictions, i) = 0;
+	}
+}
+
+static struct nfsd_file *
+nfsd_file_lookup_locked(const struct net *net, const struct cred *cred,
+			struct inode *inode, unsigned char need,
+			bool want_gc)
+{
+	struct rhlist_head *tmp, *list;
+	struct nfsd_file *nf;
+
+	list = rhltable_lookup(&nfsd_file_rhltable, &inode,
+			       nfsd_file_rhash_params);
+	rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist) {
+		if (nf->nf_may != need)
+			continue;
+		if (nf->nf_net != net)
+			continue;
+		if (!nfsd_match_cred(nf->nf_cred, cred))
+			continue;
+		if (test_bit(NFSD_FILE_GC, &nf->nf_flags) != want_gc)
+			continue;
+		if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags) == 0)
+			continue;
+
+		if (!nfsd_file_get(nf))
+			continue;
+		return nf;
+	}
+	return NULL;
+}
+
+/**
+ * nfsd_file_is_cached - are there any cached open files for this inode?
+ * @inode: inode to check
+ *
+ * The lookup matches inodes in all net namespaces and is atomic wrt
+ * nfsd_file_acquire().
+ *
+ * Return values:
+ *   %true: filecache contains at least one file matching this inode
+ *   %false: filecache contains no files matching this inode
+ */
+bool
+nfsd_file_is_cached(struct inode *inode)
+{
+	struct rhlist_head *tmp, *list;
+	struct nfsd_file *nf;
+	bool ret = false;
+
+	rcu_read_lock();
+	list = rhltable_lookup(&nfsd_file_rhltable, &inode,
+			       nfsd_file_rhash_params);
+	rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist)
+		if (test_bit(NFSD_FILE_GC, &nf->nf_flags)) {
+			ret = true;
+			break;
+		}
+	rcu_read_unlock();
+
+	trace_nfsd_file_is_cached(inode, (int)ret);
+	return ret;
+}
+
+static __be32
+nfsd_file_get_dio_attrs(const struct svc_fh *fhp, struct nfsd_file *nf)
+{
+	struct inode *inode = file_inode(nf->nf_file);
+	struct kstat stat;
+	__be32 status;
+
+	/* Currently only need to get DIO alignment info for regular files */
+	if (!S_ISREG(inode->i_mode))
+		return nfs_ok;
+
+	status = fh_getattr(fhp, &stat);
+	if (status != nfs_ok)
+		return status;
+
+	trace_nfsd_file_get_dio_attrs(inode, &stat);
+
+	if (stat.result_mask & STATX_DIOALIGN) {
+		nf->nf_dio_mem_align = stat.dio_mem_align;
+		nf->nf_dio_offset_align = stat.dio_offset_align;
+	}
+	if (stat.result_mask & STATX_DIO_READ_ALIGN)
+		nf->nf_dio_read_offset_align = stat.dio_read_offset_align;
+	else
+		nf->nf_dio_read_offset_align = nf->nf_dio_offset_align;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd_file_do_acquire(struct svc_rqst *rqstp, struct net *net,
+		     struct svc_cred *cred,
+		     struct auth_domain *client,
+		     struct svc_fh *fhp,
+		     unsigned int may_flags, struct file *file,
+		     umode_t type, bool want_gc, struct nfsd_file **pnf)
+{
+	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
+	struct nfsd_file *new, *nf;
+	bool stale_retry = true;
+	bool open_retry = true;
+	struct inode *inode;
+	__be32 status;
+	int ret;
+
+retry:
+	if (rqstp)
+		status = fh_verify(rqstp, fhp, type,
+				   may_flags|NFSD_MAY_OWNER_OVERRIDE);
+	else
+		status = fh_verify_local(net, cred, client, fhp, type,
+					 may_flags|NFSD_MAY_OWNER_OVERRIDE);
+
+	if (status != nfs_ok)
+		return status;
+	inode = d_inode(fhp->fh_dentry);
+
+	rcu_read_lock();
+	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
+	rcu_read_unlock();
+
+	if (nf)
+		goto wait_for_construction;
+
+	new = nfsd_file_alloc(net, inode, need, want_gc);
+	if (!new) {
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	rcu_read_lock();
+	spin_lock(&inode->i_lock);
+	nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc);
+	if (unlikely(nf)) {
+		spin_unlock(&inode->i_lock);
+		rcu_read_unlock();
+		nfsd_file_free(new);
+		goto wait_for_construction;
+	}
+	nf = new;
+	ret = rhltable_insert(&nfsd_file_rhltable, &nf->nf_rlist,
+			      nfsd_file_rhash_params);
+	spin_unlock(&inode->i_lock);
+	rcu_read_unlock();
+	if (likely(ret == 0))
+		goto open_file;
+
+	trace_nfsd_file_insert_err(rqstp, inode, may_flags, ret);
+	status = nfserr_jukebox;
+	goto construction_err;
+
+wait_for_construction:
+	wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE);
+
+	/* Did construction of this file fail? */
+	if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		trace_nfsd_file_cons_err(rqstp, inode, may_flags, nf);
+		if (!open_retry) {
+			status = nfserr_jukebox;
+			goto construction_err;
+		}
+		nfsd_file_put(nf);
+		open_retry = false;
+		fh_put(fhp);
+		goto retry;
+	}
+	this_cpu_inc(nfsd_file_cache_hits);
+
+	status = nfserrno(nfsd_open_break_lease(file_inode(nf->nf_file), may_flags));
+	if (status != nfs_ok) {
+		nfsd_file_put(nf);
+		nf = NULL;
+	}
+
+out:
+	if (status == nfs_ok) {
+		this_cpu_inc(nfsd_file_acquisitions);
+		nfsd_file_check_write_error(nf);
+		*pnf = nf;
+	}
+	trace_nfsd_file_acquire(rqstp, inode, may_flags, nf, status);
+	return status;
+
+open_file:
+	trace_nfsd_file_alloc(nf);
+
+	nf->nf_mark = nfsd_file_mark_find_or_create(inode);
+	if (nf->nf_mark) {
+		if (file && (file->f_mode & FMODE_OPENED)) {
+			get_file(file);
+			nf->nf_file = file;
+			status = nfs_ok;
+			trace_nfsd_file_opened(nf, status);
+		} else {
+			ret = nfsd_open_verified(fhp, type, may_flags, &nf->nf_file);
+			if (ret == -EOPENSTALE && stale_retry) {
+				stale_retry = false;
+				nfsd_file_unhash(nf);
+				clear_and_wake_up_bit(NFSD_FILE_PENDING,
+						      &nf->nf_flags);
+				if (refcount_dec_and_test(&nf->nf_ref))
+					nfsd_file_free(nf);
+				nf = NULL;
+				fh_put(fhp);
+				goto retry;
+			}
+			status = nfserrno(ret);
+			trace_nfsd_file_open(nf, status);
+			if (status == nfs_ok)
+				status = nfsd_file_get_dio_attrs(fhp, nf);
+		}
+	} else
+		status = nfserr_jukebox;
+	/*
+	 * If construction failed, or we raced with a call to unlink()
+	 * then unhash.
+	 */
+	if (status != nfs_ok || inode->i_nlink == 0)
+		nfsd_file_unhash(nf);
+	else if (want_gc)
+		nfsd_file_lru_add(nf);
+
+	clear_and_wake_up_bit(NFSD_FILE_PENDING, &nf->nf_flags);
+	if (status == nfs_ok)
+		goto out;
+
+construction_err:
+	if (refcount_dec_and_test(&nf->nf_ref))
+		nfsd_file_free(nf);
+	nf = NULL;
+	goto out;
+}
+
+/**
+ * nfsd_file_acquire_gc - Get a struct nfsd_file with an open file
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file to be opened
+ * @may_flags: NFSD_MAY_ settings for the file
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * The nfsd_file object returned by this API is reference-counted
+ * and garbage-collected. The object is retained for a few
+ * seconds after the final nfsd_file_put() in case the caller
+ * wants to re-use it.
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		     unsigned int may_flags, struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, NULL, S_IFREG, true, pnf);
+}
+
+/**
+ * nfsd_file_acquire - Get a struct nfsd_file with an open file
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file to be opened
+ * @may_flags: NFSD_MAY_ settings for the file
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put().
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, NULL, S_IFREG, false, pnf);
+}
+
+/**
+ * nfsd_file_acquire_local - Get a struct nfsd_file with an open file for localio
+ * @net: The network namespace in which to perform a lookup
+ * @cred: the user credential with which to validate access
+ * @client: the auth_domain for LOCALIO lookup
+ * @fhp: the NFS filehandle of the file to be opened
+ * @may_flags: NFSD_MAY_ settings for the file
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * This file lookup interface provide access to a file given the
+ * filehandle and credential.  No connection-based authorisation
+ * is performed and in that way it is quite different to other
+ * file access mediated by nfsd.  It allows a kernel module such as the NFS
+ * client to reach across network and filesystem namespaces to access
+ * a file.  The security implications of this should be carefully
+ * considered before use.
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put().
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
+			struct auth_domain *client, struct svc_fh *fhp,
+			unsigned int may_flags, struct nfsd_file **pnf)
+{
+	/*
+	 * Save creds before calling nfsd_file_do_acquire() (which calls
+	 * nfsd_setuser). Important because caller (LOCALIO) is from
+	 * client context.
+	 */
+	const struct cred *save_cred = get_current_cred();
+	__be32 beres;
+
+	beres = nfsd_file_do_acquire(NULL, net, cred, client, fhp, may_flags,
+				     NULL, S_IFREG, false, pnf);
+	put_cred(revert_creds(save_cred));
+	return beres;
+}
+
+/**
+ * nfsd_file_acquire_opened - Get a struct nfsd_file using existing open file
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file just created
+ * @may_flags: NFSD_MAY_ settings for the file
+ * @file: cached, already-open file (may be NULL or not yet opened)
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * Acquire a nfsd_file object that is not GC'ed. If one doesn't already exist,
+ * and @file has FMODE_OPENED set, use it to instantiate a new nfsd_file
+ * instead of opening a new one.
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			 unsigned int may_flags, struct file *file,
+			 struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL,
+				    fhp, may_flags, file, S_IFREG, false, pnf);
+}
+
+/**
+ * nfsd_file_acquire_dir - Get a struct nfsd_file with an open directory
+ * @rqstp: the RPC transaction being executed
+ * @fhp: the NFS filehandle of the file to be opened
+ * @pnf: OUT: new or found "struct nfsd_file" object
+ *
+ * The nfsd_file_object returned by this API is reference-counted
+ * but not garbage-collected. The object is unhashed after the
+ * final nfsd_file_put(). This opens directories only, and only
+ * in O_RDONLY mode.
+ *
+ * Return values:
+ *   %nfs_ok - @pnf points to an nfsd_file with its reference
+ *   count boosted.
+ *
+ * On error, an nfsstat value in network byte order is returned.
+ */
+__be32
+nfsd_file_acquire_dir(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		      struct nfsd_file **pnf)
+{
+	return nfsd_file_do_acquire(rqstp, SVC_NET(rqstp), NULL, NULL, fhp,
+				    NFSD_MAY_READ|NFSD_MAY_64BIT_COOKIE,
+				    NULL, S_IFDIR, false, pnf);
+}
+
+/*
+ * Note that fields may be added, removed or reordered in the future. Programs
+ * scraping this file for info should test the labels to ensure they're
+ * getting the correct field.
+ */
+int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
+{
+	unsigned long allocations = 0, releases = 0, evictions = 0;
+	unsigned long hits = 0, acquisitions = 0;
+	unsigned int i, count = 0, buckets = 0;
+	unsigned long lru = 0, total_age = 0;
+
+	/* Serialize with server shutdown */
+	mutex_lock(&nfsd_mutex);
+	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1) {
+		struct bucket_table *tbl;
+		struct rhashtable *ht;
+
+		lru = list_lru_count(&nfsd_file_lru);
+
+		rcu_read_lock();
+		ht = &nfsd_file_rhltable.ht;
+		count = atomic_read(&ht->nelems);
+		tbl = rht_dereference_rcu(ht->tbl, ht);
+		buckets = tbl->size;
+		rcu_read_unlock();
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	for_each_possible_cpu(i) {
+		hits += per_cpu(nfsd_file_cache_hits, i);
+		acquisitions += per_cpu(nfsd_file_acquisitions, i);
+		allocations += per_cpu(nfsd_file_allocations, i);
+		releases += per_cpu(nfsd_file_releases, i);
+		total_age += per_cpu(nfsd_file_total_age, i);
+		evictions += per_cpu(nfsd_file_evictions, i);
+	}
+
+	seq_printf(m, "total inodes:  %u\n", count);
+	seq_printf(m, "hash buckets:  %u\n", buckets);
+	seq_printf(m, "lru entries:   %lu\n", lru);
+	seq_printf(m, "cache hits:    %lu\n", hits);
+	seq_printf(m, "acquisitions:  %lu\n", acquisitions);
+	seq_printf(m, "allocations:   %lu\n", allocations);
+	seq_printf(m, "releases:      %lu\n", releases);
+	seq_printf(m, "evictions:     %lu\n", evictions);
+	if (releases)
+		seq_printf(m, "mean age (ms): %ld\n", total_age / releases);
+	else
+		seq_printf(m, "mean age (ms): -\n");
+	return 0;
+}
+
+/**
+ * nfsd_fsnotify_recalc_mask - recalculate the fsnotify mask for a nfsd_file
+ * @nf: nfsd_file to recalculate the mask on
+ *
+ * When a directory nfsd_file has a delegation added or removed, that may
+ * change the events that nfsd requires from the VFS layer. This function
+ * recalculates the fsnotify mask based on the leases present.
+ */
+void nfsd_fsnotify_recalc_mask(struct nfsd_file *nf)
+{
+	struct inode *inode = file_inode(nf->nf_file);
+	u32 lease_mask, set = 0, clear = 0;
+	struct fsnotify_mark *mark;
+
+	/* This is only needed when adding or removing dir delegs */
+	if (!S_ISDIR(inode->i_mode) || !nf->nf_mark)
+		return;
+
+	mark = &nf->nf_mark->nfm_mark;
+
+	/*
+	 * The mark is shared by every nfsd_file on this inode, so concurrent
+	 * delegation add/remove on the same directory can recalc it in
+	 * parallel. Serialize the read of the lease state and the update of
+	 * the mark so that a recalc working from a stale snapshot of the
+	 * lease list can't clobber a concurrent recalc's update.
+	 */
+	mutex_lock(&nf->nf_mark->nfm_recalc_mutex);
+
+	/* Set up notifications for any ignored delegation events */
+	lease_mask = inode_lease_ignore_mask(inode);
+
+	if (lease_mask & FL_IGN_DIR_CREATE)
+		set |= FS_CREATE | FS_MOVED_TO;
+	else
+		clear |= FS_CREATE | FS_MOVED_TO;
+
+	if (lease_mask & FL_IGN_DIR_DELETE)
+		set |= FS_DELETE | FS_MOVED_FROM;
+	else
+		clear |= FS_DELETE | FS_MOVED_FROM;
+
+	if (lease_mask & FL_IGN_DIR_RENAME)
+		set |= FS_RENAME;
+	else
+		clear |= FS_RENAME;
+
+	fsnotify_modify_mark_mask(mark, set, clear);
+	mutex_unlock(&nf->nf_mark->nfm_recalc_mutex);
+}
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
new file mode 100644
index 000000000..b224902b4
--- /dev/null
+++ b/fs/nfsd/filecache.h
@@ -0,0 +1,92 @@
+#ifndef _FS_NFSD_FILECACHE_H
+#define _FS_NFSD_FILECACHE_H
+
+#include <linux/fsnotify_backend.h>
+
+/*
+ * Limit the time that the list_lru_one lock is held during
+ * an LRU scan.
+ */
+#define NFSD_FILE_GC_BATCH     (16UL)
+
+/*
+ * This is the fsnotify_mark container that nfsd attaches to the files that it
+ * is holding open. Note that we have a separate refcount here aside from the
+ * one in the fsnotify_mark. We only want a single fsnotify_mark attached to
+ * the inode, and for each nfsd_file to hold a reference to it.
+ *
+ * The fsnotify_mark is itself refcounted, but that's not sufficient to tell us
+ * how to put that reference. If there are still outstanding nfsd_files that
+ * reference the mark, then we would want to call fsnotify_put_mark on it.
+ * If there were not, then we'd need to call fsnotify_destroy_mark. Since we
+ * can't really tell the difference, we use the nfm_mark to keep track of how
+ * many nfsd_files hold references to the mark. When that counter goes to zero
+ * then we know to call fsnotify_destroy_mark on it.
+ */
+struct nfsd_file_mark {
+	struct fsnotify_mark	nfm_mark;
+	refcount_t		nfm_ref;
+	/* serializes nfsd_fsnotify_recalc_mask() against itself */
+	struct mutex		nfm_recalc_mutex;
+};
+
+/*
+ * A representation of a file that has been opened by knfsd. These are hashed
+ * in the hashtable by inode pointer value. Note that this object doesn't
+ * hold a reference to the inode by itself, so the nf_inode pointer should
+ * never be dereferenced, only used for comparison.
+ */
+struct nfsd_file {
+	struct rhlist_head	nf_rlist;
+	void			*nf_inode;
+	struct file		*nf_file;
+	const struct cred	*nf_cred;
+	struct net		*nf_net;
+#define NFSD_FILE_HASHED	(0)
+#define NFSD_FILE_PENDING	(1)
+#define NFSD_FILE_REFERENCED	(2)
+#define NFSD_FILE_GC		(3)
+#define NFSD_FILE_RECENT	(4)
+	unsigned long		nf_flags;
+	refcount_t		nf_ref;
+	unsigned char		nf_may;
+
+	struct nfsd_file_mark	*nf_mark;
+	struct list_head	nf_lru;
+	struct list_head	nf_gc;
+	struct rcu_head		nf_rcu;
+	ktime_t			nf_birthtime;
+
+	u32			nf_dio_mem_align;
+	u32			nf_dio_offset_align;
+	u32			nf_dio_read_offset_align;
+};
+
+int nfsd_file_cache_init(void);
+void nfsd_file_cache_purge(struct net *);
+void nfsd_file_cache_shutdown(void);
+int nfsd_file_cache_start_net(struct net *net);
+void nfsd_file_cache_shutdown_net(struct net *net);
+void nfsd_file_put(struct nfsd_file *nf);
+struct net *nfsd_file_put_local(struct nfsd_file __rcu **nf);
+struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
+struct file *nfsd_file_file(struct nfsd_file *nf);
+void nfsd_file_close_inode_sync(struct inode *inode);
+void nfsd_file_close_export(struct net *net, const struct path *path);
+void nfsd_file_net_dispose(struct nfsd_net *nn);
+bool nfsd_file_is_cached(struct inode *inode);
+__be32 nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct nfsd_file **nfp);
+__be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct nfsd_file **nfp);
+__be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct file *file,
+		  struct nfsd_file **nfp);
+__be32 nfsd_file_acquire_local(struct net *net, struct svc_cred *cred,
+			       struct auth_domain *client, struct svc_fh *fhp,
+			       unsigned int may_flags, struct nfsd_file **pnf);
+__be32 nfsd_file_acquire_dir(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct nfsd_file **pnf);
+int nfsd_file_cache_stats_show(struct seq_file *m, void *v);
+void nfsd_fsnotify_recalc_mask(struct nfsd_file *nf);
+#endif /* _FS_NFSD_FILECACHE_H */
diff --git a/fs/nfsd/flexfilelayout.c b/fs/nfsd/flexfilelayout.c
new file mode 100644
index 000000000..6d531285a
--- /dev/null
+++ b/fs/nfsd/flexfilelayout.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ *
+ * The following implements a super-simple flex-file server
+ * where the NFSv4.1 mds is also the ds. And the storage is
+ * the same. I.e., writing to the mds via a NFSv4.1 WRITE
+ * goes to the same location as the NFSv3 WRITE.
+ */
+#include <linux/slab.h>
+
+#include <linux/nfsd/debug.h>
+
+#include <linux/sunrpc/addr.h>
+
+#include "flexfilelayoutxdr.h"
+#include "pnfs.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+static __be32
+nfsd4_ff_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode,
+		const struct svc_fh *fhp, struct nfsd4_layoutget *args)
+{
+	struct nfsd4_layout_seg *seg = &args->lg_seg;
+	u32 device_generation = 0;
+	int error;
+	uid_t u;
+
+	struct pnfs_ff_layout *fl;
+
+	/*
+	 * The super simple flex file server has 1 mirror, 1 data server,
+	 * and 1 file handle. So instead of 4 allocs, do 1 for now.
+	 * Zero it out for the stateid - don't want junk in there!
+	 */
+	error = -ENOMEM;
+	fl = kzalloc_obj(*fl);
+	if (!fl)
+		goto out_error;
+	args->lg_content = fl;
+
+	/*
+	 * Avoid layout commit, try to force the I/O to the DS,
+	 * and for fun, cause all IOMODE_RW layout segments to
+	 * effectively be WRITE only.
+	 */
+	fl->flags = FF_FLAGS_NO_LAYOUTCOMMIT | FF_FLAGS_NO_IO_THRU_MDS |
+		    FF_FLAGS_NO_READ_IO;
+
+	/* Do not allow a IOMODE_READ segment to have write pemissions */
+	if (seg->iomode == IOMODE_READ) {
+		u = from_kuid(&init_user_ns, inode->i_uid) + 1;
+		fl->uid = make_kuid(&init_user_ns, u);
+	} else
+		fl->uid = inode->i_uid;
+	fl->gid = inode->i_gid;
+
+	error = nfsd4_set_deviceid(&fl->deviceid, fhp, device_generation);
+	if (error)
+		goto out_error;
+
+	fl->fh.size = fhp->fh_handle.fh_size;
+	memcpy(fl->fh.data, &fhp->fh_handle.fh_raw, fl->fh.size);
+
+	/* Give whole file layout segments */
+	seg->offset = 0;
+	seg->length = NFS4_MAX_UINT64;
+
+	dprintk("GET: 0x%llx:0x%llx %d\n", seg->offset, seg->length,
+		seg->iomode);
+	return 0;
+
+out_error:
+	seg->length = 0;
+	return nfserrno(error);
+}
+
+static __be32
+nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
+		struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_ff_device_addr *da;
+
+	u16 port;
+	char addr[INET6_ADDRSTRLEN];
+
+	da = kzalloc_obj(struct pnfs_ff_device_addr);
+	if (!da)
+		return nfserrno(-ENOMEM);
+
+	gdp->gd_device = da;
+
+	da->version = 3;
+	da->minor_version = 0;
+
+	da->rsize = svc_max_payload(rqstp);
+	da->wsize = da->rsize;
+
+	rpc_ntop((struct sockaddr *)&rqstp->rq_daddr,
+		 addr, INET6_ADDRSTRLEN);
+	if (rqstp->rq_daddr.ss_family == AF_INET) {
+		struct sockaddr_in *sin;
+
+		sin = (struct sockaddr_in *)&rqstp->rq_daddr;
+		port = ntohs(sin->sin_port);
+		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp");
+		da->netaddr.netid_len = 3;
+	} else {
+		struct sockaddr_in6 *sin6;
+
+		sin6 = (struct sockaddr_in6 *)&rqstp->rq_daddr;
+		port = ntohs(sin6->sin6_port);
+		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp6");
+		da->netaddr.netid_len = 4;
+	}
+
+	da->netaddr.addr_len =
+		snprintf(da->netaddr.addr, FF_ADDR_LEN + 1,
+			 "%s.%d.%d", addr, port >> 8, port & 0xff);
+
+	da->tightly_coupled = false;
+
+	return 0;
+}
+
+static __be32
+nfsd4_ff_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp,
+		struct nfsd4_layoutcommit *lcp)
+{
+	return nfs_ok;
+}
+
+const struct nfsd4_layout_ops ff_layout_ops = {
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.disable_recalls	= true,
+	.proc_getdeviceinfo	= nfsd4_ff_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_ff_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_ff_proc_layoutget,
+	.encode_layoutget	= nfsd4_ff_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_ff_proc_layoutcommit,
+};
diff --git a/fs/nfsd/flexfilelayoutxdr.c b/fs/nfsd/flexfilelayoutxdr.c
new file mode 100644
index 000000000..374e52d30
--- /dev/null
+++ b/fs/nfsd/flexfilelayoutxdr.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ */
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs4.h>
+
+#include "nfsd.h"
+#include "flexfilelayoutxdr.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+struct ff_idmap {
+	char buf[11];
+	int len;
+};
+
+__be32
+nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
+		const struct nfsd4_layoutget *lgp)
+{
+	const struct pnfs_ff_layout *fl = lgp->lg_content;
+	int len, mirror_len, ds_len, fh_len;
+	__be32 *p;
+
+	/*
+	 * Unlike nfsd4_encode_user, we know these will
+	 * always be stringified.
+	 */
+	struct ff_idmap uid;
+	struct ff_idmap gid;
+
+	fh_len = 4 + xdr_align_size(fl->fh.size);
+
+	uid.len = sprintf(uid.buf, "%u", from_kuid(&init_user_ns, fl->uid));
+	gid.len = sprintf(gid.buf, "%u", from_kgid(&init_user_ns, fl->gid));
+
+	/* data server entry: deviceid + efficiency + stateid + fh list +
+	 * user + group + flags + stats_collect_hint
+	 */
+	ds_len = 16 + 4 + 4 + sizeof(stateid_opaque_t) + 4 + fh_len +
+		 4 + xdr_align_size(uid.len) +
+		 4 + xdr_align_size(gid.len) +
+		 4 + 4;
+
+	/* mirror: ds_count + ds */
+	mirror_len = 4 + ds_len;
+
+	/* stripe_unit + mirror_count + mirror */
+	len = 12 + mirror_len;
+
+	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
+	if (!p)
+		return nfserr_toosmall;
+
+	*p++ = cpu_to_be32(len);
+	p = xdr_encode_hyper(p, 0);		/* stripe unit of 1 */
+
+	*p++ = cpu_to_be32(1);			/* single mirror */
+	*p++ = cpu_to_be32(1);			/* single data server */
+
+	p = svcxdr_encode_deviceid4(p, &fl->deviceid);
+
+	*p++ = cpu_to_be32(1);			/* efficiency */
+
+	*p++ = cpu_to_be32(fl->stateid.si_generation);
+	p = xdr_encode_opaque_fixed(p, &fl->stateid.si_opaque,
+				    sizeof(stateid_opaque_t));
+
+	*p++ = cpu_to_be32(1);			/* single file handle */
+	p = xdr_encode_opaque(p, fl->fh.data, fl->fh.size);
+
+	p = xdr_encode_opaque(p, uid.buf, uid.len);
+	p = xdr_encode_opaque(p, gid.buf, gid.len);
+
+	*p++ = cpu_to_be32(fl->flags);
+	*p++ = cpu_to_be32(0);			/* No stats collect hint */
+
+	return 0;
+}
+
+__be32
+nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
+		const struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_ff_device_addr *da = gdp->gd_device;
+	int len;
+	int ver_len;
+	int addr_len;
+	__be32 *p;
+
+	/*
+	 * See paragraph 5 of RFC 8881 S18.40.3.
+	 */
+	if (!gdp->gd_maxcount) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+
+	/* len + padding for two strings */
+	addr_len = 8 + xdr_align_size(da->netaddr.netid_len) +
+		   xdr_align_size(da->netaddr.addr_len);
+	ver_len = 20;
+
+	len = 4 + ver_len + 4 + addr_len;
+
+	p = xdr_reserve_space(xdr, len + sizeof(__be32));
+	if (!p)
+		return nfserr_resource;
+
+	/*
+	 * Fill in the overall length and number of volumes at the beginning
+	 * of the layout.
+	 */
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(1);			/* 1 netaddr */
+	p = xdr_encode_opaque(p, da->netaddr.netid, da->netaddr.netid_len);
+	p = xdr_encode_opaque(p, da->netaddr.addr, da->netaddr.addr_len);
+
+	*p++ = cpu_to_be32(1);			/* 1 versions */
+
+	*p++ = cpu_to_be32(da->version);
+	*p++ = cpu_to_be32(da->minor_version);
+	*p++ = cpu_to_be32(da->rsize);
+	*p++ = cpu_to_be32(da->wsize);
+	*p++ = cpu_to_be32(da->tightly_coupled);
+
+	return 0;
+}
diff --git a/fs/nfsd/flexfilelayoutxdr.h b/fs/nfsd/flexfilelayoutxdr.h
new file mode 100644
index 000000000..6d5a1066a
--- /dev/null
+++ b/fs/nfsd/flexfilelayoutxdr.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ */
+#ifndef _NFSD_FLEXFILELAYOUTXDR_H
+#define _NFSD_FLEXFILELAYOUTXDR_H 1
+
+#include <linux/inet.h>
+#include "xdr4.h"
+
+#define FF_FLAGS_NO_LAYOUTCOMMIT 1
+#define FF_FLAGS_NO_IO_THRU_MDS  2
+#define FF_FLAGS_NO_READ_IO      4
+
+struct xdr_stream;
+
+#define FF_NETID_LEN		(4)
+#define FF_ADDR_LEN		(INET6_ADDRSTRLEN + 8)
+struct pnfs_ff_netaddr {
+	char				netid[FF_NETID_LEN + 1];
+	char				addr[FF_ADDR_LEN + 1];
+	u32				netid_len;
+	u32				addr_len;
+};
+
+struct pnfs_ff_device_addr {
+	struct pnfs_ff_netaddr		netaddr;
+	u32				version;
+	u32				minor_version;
+	u32				rsize;
+	u32				wsize;
+	bool				tightly_coupled;
+};
+
+struct pnfs_ff_layout {
+	u32				flags;
+	u32				stats_collect_hint;
+	kuid_t				uid;
+	kgid_t				gid;
+	struct nfsd4_deviceid		deviceid;
+	stateid_t			stateid;
+	struct nfs_fh			fh;
+};
+
+__be32 nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
+		const struct nfsd4_getdeviceinfo *gdp);
+__be32 nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
+		const struct nfsd4_layoutget *lgp);
+
+#endif /* _NFSD_FLEXFILELAYOUTXDR_H */
diff --git a/fs/nfsd/idmap.h b/fs/nfsd/idmap.h
new file mode 100644
index 000000000..23cc85d1e
--- /dev/null
+++ b/fs/nfsd/idmap.h
@@ -0,0 +1,60 @@
+/*
+ *  Mapping of UID to name and vice versa.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of
+ *  Michigan.  All rights reserved.
+> *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LINUX_NFSD_IDMAP_H
+#define LINUX_NFSD_IDMAP_H
+
+#include <linux/in.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs_idmap.h>
+
+#ifdef CONFIG_NFSD_V4
+int nfsd_idmap_init(struct net *);
+void nfsd_idmap_shutdown(struct net *);
+#else
+static inline int nfsd_idmap_init(struct net *net)
+{
+	return 0;
+}
+static inline void nfsd_idmap_shutdown(struct net *net)
+{
+}
+#endif
+
+__be32 nfsd_map_name_to_uid(struct svc_rqst *, const char *, size_t, kuid_t *);
+__be32 nfsd_map_name_to_gid(struct svc_rqst *, const char *, size_t, kgid_t *);
+__be32 nfsd4_encode_user(struct xdr_stream *, struct svc_rqst *, kuid_t);
+__be32 nfsd4_encode_group(struct xdr_stream *, struct svc_rqst *, kgid_t);
+
+#endif /* LINUX_NFSD_IDMAP_H */
diff --git a/fs/nfsd/localio.c b/fs/nfsd/localio.c
new file mode 100644
index 000000000..c458c01e9
--- /dev/null
+++ b/fs/nfsd/localio.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NFS server support for local clients to bypass network stack
+ *
+ * Copyright (C) 2014 Weston Andros Adamson <dros@primarydata.com>
+ * Copyright (C) 2019 Trond Myklebust <trond.myklebust@hammerspace.com>
+ * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
+ * Copyright (C) 2024 NeilBrown <neilb@suse.de>
+ */
+
+#include <linux/exportfs.h>
+#include <linux/sunrpc/svcauth.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs_common.h>
+#include <linux/nfslocalio.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_xdr.h>
+#include <linux/string.h>
+
+#include "nfsd.h"
+#include "vfs.h"
+#include "netns.h"
+#include "filecache.h"
+#include "cache.h"
+
+/**
+ * nfsd_open_local_fh - lookup a local filehandle @nfs_fh and map to nfsd_file
+ *
+ * @net: 'struct net' to get the proper nfsd_net required for LOCALIO access
+ * @dom: 'struct auth_domain' required for LOCALIO access
+ * @rpc_clnt: rpc_clnt that the client established
+ * @cred: cred that the client established
+ * @nfs_fh: filehandle to lookup
+ * @pnf: place to find the nfsd_file, or store it if it was non-NULL
+ * @fmode: fmode_t to use for open
+ *
+ * This function maps a local fh to a path on a local filesystem.
+ * This is useful when the nfs client has the local server mounted - it can
+ * avoid all the NFS overhead with reads, writes and commits.
+ *
+ * On successful return, returned nfsd_file will have its nf_net member
+ * set. Caller (NFS client) is responsible for calling nfsd_net_put and
+ * nfsd_file_put (via nfs_to_nfsd_file_put_local).
+ */
+static struct nfsd_file *
+nfsd_open_local_fh(struct net *net, struct auth_domain *dom,
+		   struct rpc_clnt *rpc_clnt, const struct cred *cred,
+		   const struct nfs_fh *nfs_fh, struct nfsd_file __rcu **pnf,
+		   const fmode_t fmode)
+{
+	int mayflags = NFSD_MAY_LOCALIO;
+	struct svc_cred rq_cred;
+	struct svc_fh fh;
+	struct nfsd_file *localio;
+	__be32 beres;
+
+	if (nfs_fh->size > NFS4_FHSIZE)
+		return ERR_PTR(-EINVAL);
+
+	if (!nfsd_net_try_get(net))
+		return ERR_PTR(-ENXIO);
+
+	rcu_read_lock();
+	localio = nfsd_file_get(rcu_dereference(*pnf));
+	rcu_read_unlock();
+	if (localio)
+		return localio;
+
+	/* nfs_fh -> svc_fh */
+	fh_init(&fh, NFS4_FHSIZE);
+	fh.fh_handle.fh_size = nfs_fh->size;
+	memcpy(fh.fh_handle.fh_raw, nfs_fh->data, nfs_fh->size);
+
+	if (fmode & FMODE_READ)
+		mayflags |= NFSD_MAY_READ;
+	if (fmode & FMODE_WRITE)
+		mayflags |= NFSD_MAY_WRITE;
+
+	svcauth_map_clnt_to_svc_cred_local(rpc_clnt, cred, &rq_cred);
+
+	beres = nfsd_file_acquire_local(net, &rq_cred, dom,
+					&fh, mayflags, &localio);
+	if (beres)
+		localio = ERR_PTR(nfs_stat_to_errno(be32_to_cpu(beres)));
+
+	fh_put(&fh);
+	if (rq_cred.cr_group_info)
+		put_group_info(rq_cred.cr_group_info);
+
+	if (!IS_ERR(localio)) {
+		struct nfsd_file *new;
+		if (!nfsd_net_try_get(net)) {
+			nfsd_file_put(localio);
+			nfsd_net_put(net);
+			return ERR_PTR(-ENXIO);
+		}
+		nfsd_file_get(localio);
+	again:
+		rcu_read_lock();
+		new = unrcu_pointer(cmpxchg(pnf, NULL, RCU_INITIALIZER(localio)));
+		if (new) {
+			/* Some other thread installed an nfsd_file */
+			if (nfsd_file_get(new) == NULL) {
+				rcu_read_unlock();
+				goto again;
+			}
+			rcu_read_unlock();
+			/*
+			 * Drop the ref we were going to install (both file and
+			 * net) and the one we were going to return (only file).
+			 */
+			nfsd_file_put(localio);
+			nfsd_net_put(net);
+			nfsd_file_put(localio);
+			localio = new;
+		} else {
+			rcu_read_unlock();
+		}
+	} else
+		nfsd_net_put(net);
+
+	return localio;
+}
+
+static void nfsd_file_dio_alignment(struct nfsd_file *nf,
+				    u32 *nf_dio_mem_align,
+				    u32 *nf_dio_offset_align,
+				    u32 *nf_dio_read_offset_align)
+{
+	*nf_dio_mem_align = nf->nf_dio_mem_align;
+	*nf_dio_offset_align = nf->nf_dio_offset_align;
+	*nf_dio_read_offset_align = nf->nf_dio_read_offset_align;
+}
+
+static const struct nfsd_localio_operations nfsd_localio_ops = {
+	.nfsd_net_try_get  = nfsd_net_try_get,
+	.nfsd_net_put  = nfsd_net_put,
+	.nfsd_open_local_fh = nfsd_open_local_fh,
+	.nfsd_file_put_local = nfsd_file_put_local,
+	.nfsd_file_file = nfsd_file_file,
+	.nfsd_file_dio_alignment = nfsd_file_dio_alignment,
+};
+
+void nfsd_localio_ops_init(void)
+{
+	nfs_to = &nfsd_localio_ops;
+}
+
+/*
+ * UUID_IS_LOCAL XDR functions
+ */
+
+static __be32 localio_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+struct localio_uuidarg {
+	uuid_t			uuid;
+};
+
+static __be32 localio_proc_uuid_is_local(struct svc_rqst *rqstp)
+{
+	struct localio_uuidarg *argp = rqstp->rq_argp;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs_uuid_is_local(&argp->uuid, &nn->local_clients,
+			  &nn->local_clients_lock,
+			  net, rqstp->rq_client, THIS_MODULE);
+
+	return rpc_success;
+}
+
+static bool localio_decode_uuidarg(struct svc_rqst *rqstp,
+				   struct xdr_stream *xdr)
+{
+	struct localio_uuidarg *argp = rqstp->rq_argp;
+	u8 uuid[UUID_SIZE];
+
+	if (decode_opaque_fixed(xdr, uuid, UUID_SIZE))
+		return false;
+	import_uuid(&argp->uuid, uuid);
+
+	return true;
+}
+
+static const struct svc_procedure localio_procedures1[] = {
+	[LOCALIOPROC_NULL] = {
+		.pc_func = localio_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+		.pc_name = "NULL",
+	},
+	[LOCALIOPROC_UUID_IS_LOCAL] = {
+		.pc_func = localio_proc_uuid_is_local,
+		.pc_decode = localio_decode_uuidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct localio_uuidarg),
+		.pc_argzero = sizeof(struct localio_uuidarg),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_name = "UUID_IS_LOCAL",
+	},
+};
+
+#define LOCALIO_NR_PROCEDURES ARRAY_SIZE(localio_procedures1)
+const struct svc_version localio_version1 = {
+	.vs_vers	= 1,
+	.vs_nproc	= LOCALIO_NR_PROCEDURES,
+	.vs_proc	= localio_procedures1,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= XDR_QUADLEN(UUID_SIZE),
+	.vs_hidden	= true,
+};
diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c
new file mode 100644
index 000000000..72a5b4998
--- /dev/null
+++ b/fs/nfsd/lockd.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains all the stubs needed when communicating with lockd.
+ * This level of indirection is necessary so we can run nfsd+lockd without
+ * requiring the nfs client to be compiled in/loaded, and vice versa.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/file.h>
+#include <linux/lockd/bind.h>
+#include "nfsd.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_LOCKD
+
+/**
+ * nlm_fopen - Open an NFSD file
+ * @rqstp: NLM RPC procedure execution context
+ * @f: NFS file handle to be opened
+ * @filp: OUT: an opened struct file
+ * @flags: the POSIX open flags to use
+ *
+ * nlm_fopen() holds the dentry reference until nlm_fclose() releases it.
+ *
+ * Returns zero on success or a negative errno value if the file
+ * cannot be opened.
+ */
+static int nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f,
+		     struct file **filp, int flags)
+{
+	__be32		nfserr;
+	int		access;
+	struct svc_fh	fh;
+
+	/* must initialize before using! but maxsize doesn't matter */
+	fh_init(&fh,0);
+	fh.fh_handle.fh_size = f->size;
+	memcpy(&fh.fh_handle.fh_raw, f->data, f->size);
+	fh.fh_export = NULL;
+
+	/*
+	 * Allow BYPASS_GSS as some client implementations use AUTH_SYS
+	 * for NLM even when GSS is used for NFS.
+	 * Allow OWNER_OVERRIDE as permission might have been changed
+	 * after the file was opened.
+	 * Pass MAY_NLM so that authentication can be completely bypassed
+	 * if NFSEXP_NOAUTHNLM is set.  Some older clients use AUTH_NULL
+	 * for NLM requests.
+	 */
+	access = (flags == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ;
+	access |= NFSD_MAY_NLM | NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_BYPASS_GSS;
+	nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp);
+	fh_put(&fh);
+
+	switch (nfserr) {
+	case nfs_ok:
+		break;
+	case nfserr_jukebox:
+		/*
+		 * This error can indicate a presence of a conflicting
+		 * delegation to an NLM lock request. Options are:
+		 * (1) For now, drop this request and make the client
+		 * retry. When delegation is returned, client's lock retry
+		 * will complete.
+		 * (2) NLM4_DENIED as per "spec" signals to the client
+		 * that the lock is unavailable now but client can retry.
+		 * Linux client implementation does not. It treats
+		 * NLM4_DENIED same as NLM4_FAILED and fails the request.
+		 * (3) For the future, treat this as blocked lock and try
+		 * to callback when the delegation is returned but might
+		 * not have a proper lock request to block on.
+		 */
+		return -EWOULDBLOCK;
+	case nfserr_stale:
+		return -ESTALE;
+	default:
+		return -ENOLCK;
+	}
+
+	return 0;
+}
+
+/**
+ * nlm_fclose - Close an NFSD file
+ * @filp: a struct file that was opened by nlm_fopen()
+ */
+static void
+nlm_fclose(struct file *filp)
+{
+	fput(filp);
+}
+
+static const struct nlmsvc_binding nfsd_nlm_ops = {
+	.owner		= THIS_MODULE,
+	.fopen		= nlm_fopen,		/* open file for locking */
+	.fclose		= nlm_fclose,		/* close file */
+};
+
+void
+nfsd_lockd_init(void)
+{
+	dprintk("nfsd: initializing lockd\n");
+	rcu_assign_pointer(nlmsvc_ops, &nfsd_nlm_ops);
+}
+
+void
+nfsd_lockd_shutdown(void)
+{
+	RCU_INIT_POINTER(nlmsvc_ops, NULL);
+	synchronize_rcu();
+}
diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c
new file mode 100644
index 000000000..eba8b353f
--- /dev/null
+++ b/fs/nfsd/netlink.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/nfsd.yaml */
+/* YNL-GEN kernel source */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "netlink.h"
+
+#include <uapi/linux/nfsd_netlink.h>
+
+/* Common nested types */
+const struct nla_policy nfsd_auth_flavor_nl_policy[NFSD_A_AUTH_FLAVOR_FLAGS + 1] = {
+	[NFSD_A_AUTH_FLAVOR_PSEUDOFLAVOR] = { .type = NLA_U32, },
+	[NFSD_A_AUTH_FLAVOR_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0x3ffff),
+};
+
+const struct nla_policy nfsd_expkey_nl_policy[NFSD_A_EXPKEY_PATH + 1] = {
+	[NFSD_A_EXPKEY_SEQNO] = { .type = NLA_U64, },
+	[NFSD_A_EXPKEY_CLIENT] = { .type = NLA_NUL_STRING, },
+	[NFSD_A_EXPKEY_FSIDTYPE] = { .type = NLA_U8, },
+	[NFSD_A_EXPKEY_FSID] = { .type = NLA_BINARY, },
+	[NFSD_A_EXPKEY_NEGATIVE] = { .type = NLA_FLAG, },
+	[NFSD_A_EXPKEY_EXPIRY] = { .type = NLA_U64, },
+	[NFSD_A_EXPKEY_PATH] = { .type = NLA_NUL_STRING, },
+};
+
+const struct nla_policy nfsd_fslocation_nl_policy[NFSD_A_FSLOCATION_PATH + 1] = {
+	[NFSD_A_FSLOCATION_HOST] = { .type = NLA_NUL_STRING, },
+	[NFSD_A_FSLOCATION_PATH] = { .type = NLA_NUL_STRING, },
+};
+
+const struct nla_policy nfsd_fslocations_nl_policy[NFSD_A_FSLOCATIONS_LOCATION + 1] = {
+	[NFSD_A_FSLOCATIONS_LOCATION] = NLA_POLICY_NESTED(nfsd_fslocation_nl_policy),
+};
+
+const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1] = {
+	[NFSD_A_SOCK_ADDR] = { .type = NLA_BINARY, },
+	[NFSD_A_SOCK_TRANSPORT_NAME] = { .type = NLA_NUL_STRING, },
+};
+
+const struct nla_policy nfsd_svc_export_nl_policy[NFSD_A_SVC_EXPORT_FSID + 1] = {
+	[NFSD_A_SVC_EXPORT_SEQNO] = { .type = NLA_U64, },
+	[NFSD_A_SVC_EXPORT_CLIENT] = { .type = NLA_NUL_STRING, },
+	[NFSD_A_SVC_EXPORT_PATH] = { .type = NLA_NUL_STRING, },
+	[NFSD_A_SVC_EXPORT_NEGATIVE] = { .type = NLA_FLAG, },
+	[NFSD_A_SVC_EXPORT_EXPIRY] = { .type = NLA_U64, },
+	[NFSD_A_SVC_EXPORT_ANON_UID] = { .type = NLA_U32, },
+	[NFSD_A_SVC_EXPORT_ANON_GID] = { .type = NLA_U32, },
+	[NFSD_A_SVC_EXPORT_FSLOCATIONS] = NLA_POLICY_NESTED(nfsd_fslocations_nl_policy),
+	[NFSD_A_SVC_EXPORT_UUID] = { .type = NLA_BINARY, },
+	[NFSD_A_SVC_EXPORT_SECINFO] = NLA_POLICY_NESTED(nfsd_auth_flavor_nl_policy),
+	[NFSD_A_SVC_EXPORT_XPRTSEC] = NLA_POLICY_MASK(NLA_U32, 0x7),
+	[NFSD_A_SVC_EXPORT_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0x3ffff),
+	[NFSD_A_SVC_EXPORT_FSID] = { .type = NLA_S32, },
+};
+
+const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1] = {
+	[NFSD_A_VERSION_MAJOR] = { .type = NLA_U32, },
+	[NFSD_A_VERSION_MINOR] = { .type = NLA_U32, },
+	[NFSD_A_VERSION_ENABLED] = { .type = NLA_FLAG, },
+};
+
+/* NFSD_CMD_THREADS_SET - do */
+static const struct nla_policy nfsd_threads_set_nl_policy[NFSD_A_SERVER_FH_KEY + 1] = {
+	[NFSD_A_SERVER_THREADS] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_GRACETIME] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_LEASETIME] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_SCOPE] = { .type = NLA_NUL_STRING, },
+	[NFSD_A_SERVER_MIN_THREADS] = { .type = NLA_U32, },
+	[NFSD_A_SERVER_FH_KEY] = NLA_POLICY_EXACT_LEN(16),
+};
+
+/* NFSD_CMD_VERSION_SET - do */
+static const struct nla_policy nfsd_version_set_nl_policy[NFSD_A_SERVER_PROTO_VERSION + 1] = {
+	[NFSD_A_SERVER_PROTO_VERSION] = NLA_POLICY_NESTED(nfsd_version_nl_policy),
+};
+
+/* NFSD_CMD_LISTENER_SET - do */
+static const struct nla_policy nfsd_listener_set_nl_policy[NFSD_A_SERVER_SOCK_ADDR + 1] = {
+	[NFSD_A_SERVER_SOCK_ADDR] = NLA_POLICY_NESTED(nfsd_sock_nl_policy),
+};
+
+/* NFSD_CMD_POOL_MODE_SET - do */
+static const struct nla_policy nfsd_pool_mode_set_nl_policy[NFSD_A_POOL_MODE_MODE + 1] = {
+	[NFSD_A_POOL_MODE_MODE] = { .type = NLA_NUL_STRING, },
+};
+
+/* NFSD_CMD_SVC_EXPORT_SET_REQS - do */
+static const struct nla_policy nfsd_svc_export_set_reqs_nl_policy[NFSD_A_SVC_EXPORT_REQS_REQUESTS + 1] = {
+	[NFSD_A_SVC_EXPORT_REQS_REQUESTS] = NLA_POLICY_NESTED(nfsd_svc_export_nl_policy),
+};
+
+/* NFSD_CMD_EXPKEY_SET_REQS - do */
+static const struct nla_policy nfsd_expkey_set_reqs_nl_policy[NFSD_A_EXPKEY_REQS_REQUESTS + 1] = {
+	[NFSD_A_EXPKEY_REQS_REQUESTS] = NLA_POLICY_NESTED(nfsd_expkey_nl_policy),
+};
+
+/* NFSD_CMD_CACHE_FLUSH - do */
+static const struct nla_policy nfsd_cache_flush_nl_policy[NFSD_A_CACHE_FLUSH_MASK + 1] = {
+	[NFSD_A_CACHE_FLUSH_MASK] = NLA_POLICY_MASK(NLA_U32, 0x3),
+};
+
+/* NFSD_CMD_UNLOCK_IP - do */
+static const struct nla_policy nfsd_unlock_ip_nl_policy[NFSD_A_UNLOCK_IP_ADDRESS + 1] = {
+	[NFSD_A_UNLOCK_IP_ADDRESS] = NLA_POLICY_MIN_LEN(16),
+};
+
+/* NFSD_CMD_UNLOCK_FILESYSTEM - do */
+static const struct nla_policy nfsd_unlock_filesystem_nl_policy[NFSD_A_UNLOCK_FILESYSTEM_PATH + 1] = {
+	[NFSD_A_UNLOCK_FILESYSTEM_PATH] = { .type = NLA_NUL_STRING, },
+};
+
+/* NFSD_CMD_UNLOCK_EXPORT - do */
+static const struct nla_policy nfsd_unlock_export_nl_policy[NFSD_A_UNLOCK_EXPORT_PATH + 1] = {
+	[NFSD_A_UNLOCK_EXPORT_PATH] = { .type = NLA_NUL_STRING, },
+};
+
+/* Ops table for nfsd */
+static const struct genl_split_ops nfsd_nl_ops[] = {
+	{
+		.cmd	= NFSD_CMD_RPC_STATUS_GET,
+		.dumpit	= nfsd_nl_rpc_status_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
+	{
+		.cmd		= NFSD_CMD_THREADS_SET,
+		.doit		= nfsd_nl_threads_set_doit,
+		.policy		= nfsd_threads_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_FH_KEY,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_THREADS_GET,
+		.doit	= nfsd_nl_threads_get_doit,
+		.flags	= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_VERSION_SET,
+		.doit		= nfsd_nl_version_set_doit,
+		.policy		= nfsd_version_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_PROTO_VERSION,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_VERSION_GET,
+		.doit	= nfsd_nl_version_get_doit,
+		.flags	= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_LISTENER_SET,
+		.doit		= nfsd_nl_listener_set_doit,
+		.policy		= nfsd_listener_set_nl_policy,
+		.maxattr	= NFSD_A_SERVER_SOCK_ADDR,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_LISTENER_GET,
+		.doit	= nfsd_nl_listener_get_doit,
+		.flags	= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_POOL_MODE_SET,
+		.doit		= nfsd_nl_pool_mode_set_doit,
+		.policy		= nfsd_pool_mode_set_nl_policy,
+		.maxattr	= NFSD_A_POOL_MODE_MODE,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_POOL_MODE_GET,
+		.doit	= nfsd_nl_pool_mode_get_doit,
+		.flags	= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_SVC_EXPORT_GET_REQS,
+		.dumpit	= nfsd_nl_svc_export_get_reqs_dumpit,
+		.flags	= GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
+	},
+	{
+		.cmd		= NFSD_CMD_SVC_EXPORT_SET_REQS,
+		.doit		= nfsd_nl_svc_export_set_reqs_doit,
+		.policy		= nfsd_svc_export_set_reqs_nl_policy,
+		.maxattr	= NFSD_A_SVC_EXPORT_REQS_REQUESTS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_EXPKEY_GET_REQS,
+		.dumpit	= nfsd_nl_expkey_get_reqs_dumpit,
+		.flags	= GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
+	},
+	{
+		.cmd		= NFSD_CMD_EXPKEY_SET_REQS,
+		.doit		= nfsd_nl_expkey_set_reqs_doit,
+		.policy		= nfsd_expkey_set_reqs_nl_policy,
+		.maxattr	= NFSD_A_EXPKEY_REQS_REQUESTS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_CACHE_FLUSH,
+		.doit		= nfsd_nl_cache_flush_doit,
+		.policy		= nfsd_cache_flush_nl_policy,
+		.maxattr	= NFSD_A_CACHE_FLUSH_MASK,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_UNLOCK_IP,
+		.doit		= nfsd_nl_unlock_ip_doit,
+		.policy		= nfsd_unlock_ip_nl_policy,
+		.maxattr	= NFSD_A_UNLOCK_IP_ADDRESS,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_UNLOCK_FILESYSTEM,
+		.doit		= nfsd_nl_unlock_filesystem_doit,
+		.policy		= nfsd_unlock_filesystem_nl_policy,
+		.maxattr	= NFSD_A_UNLOCK_FILESYSTEM_PATH,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd		= NFSD_CMD_UNLOCK_EXPORT,
+		.doit		= nfsd_nl_unlock_export_doit,
+		.policy		= nfsd_unlock_export_nl_policy,
+		.maxattr	= NFSD_A_UNLOCK_EXPORT_PATH,
+		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NFSD_CMD_SERVER_STATS_GET,
+		.dumpit	= nfsd_nl_server_stats_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
+};
+
+static const struct genl_multicast_group nfsd_nl_mcgrps[] = {
+	[NFSD_NLGRP_NONE] = { "none", },
+	[NFSD_NLGRP_EXPORTD] = { "exportd", },
+};
+
+struct genl_family nfsd_nl_family __ro_after_init = {
+	.name		= NFSD_FAMILY_NAME,
+	.version	= NFSD_FAMILY_VERSION,
+	.netnsok	= true,
+	.parallel_ops	= true,
+	.module		= THIS_MODULE,
+	.split_ops	= nfsd_nl_ops,
+	.n_split_ops	= ARRAY_SIZE(nfsd_nl_ops),
+	.mcgrps		= nfsd_nl_mcgrps,
+	.n_mcgrps	= ARRAY_SIZE(nfsd_nl_mcgrps),
+};
diff --git a/fs/nfsd/netlink.h b/fs/nfsd/netlink.h
new file mode 100644
index 000000000..027e2953d
--- /dev/null
+++ b/fs/nfsd/netlink.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/nfsd.yaml */
+/* YNL-GEN kernel header */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#ifndef _LINUX_NFSD_GEN_H
+#define _LINUX_NFSD_GEN_H
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include <uapi/linux/nfsd_netlink.h>
+
+/* Common nested types */
+extern const struct nla_policy nfsd_auth_flavor_nl_policy[NFSD_A_AUTH_FLAVOR_FLAGS + 1];
+extern const struct nla_policy nfsd_expkey_nl_policy[NFSD_A_EXPKEY_PATH + 1];
+extern const struct nla_policy nfsd_fslocation_nl_policy[NFSD_A_FSLOCATION_PATH + 1];
+extern const struct nla_policy nfsd_fslocations_nl_policy[NFSD_A_FSLOCATIONS_LOCATION + 1];
+extern const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1];
+extern const struct nla_policy nfsd_svc_export_nl_policy[NFSD_A_SVC_EXPORT_FSID + 1];
+extern const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1];
+
+int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
+				  struct netlink_callback *cb);
+int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_pool_mode_set_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_svc_export_get_reqs_dumpit(struct sk_buff *skb,
+				       struct netlink_callback *cb);
+int nfsd_nl_svc_export_set_reqs_doit(struct sk_buff *skb,
+				     struct genl_info *info);
+int nfsd_nl_expkey_get_reqs_dumpit(struct sk_buff *skb,
+				   struct netlink_callback *cb);
+int nfsd_nl_expkey_set_reqs_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_cache_flush_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_unlock_ip_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_unlock_filesystem_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_unlock_export_doit(struct sk_buff *skb, struct genl_info *info);
+int nfsd_nl_server_stats_get_dumpit(struct sk_buff *skb,
+				    struct netlink_callback *cb);
+
+enum {
+	NFSD_NLGRP_NONE,
+	NFSD_NLGRP_EXPORTD,
+};
+
+extern struct genl_family nfsd_nl_family;
+
+#endif /* _LINUX_NFSD_GEN_H */
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
new file mode 100644
index 000000000..71eebfea0
--- /dev/null
+++ b/fs/nfsd/netns.h
@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * per net namespace data structures for nfsd
+ *
+ * Copyright (C) 2012, Jeff Layton <jlayton@redhat.com>
+ */
+
+#ifndef __NFSD_NETNS_H__
+#define __NFSD_NETNS_H__
+
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <linux/filelock.h>
+#include <linux/nfs4.h>
+#include <linux/percpu_counter.h>
+#include <linux/percpu-refcount.h>
+#include <linux/siphash.h>
+#include <linux/sunrpc/stats.h>
+
+/* Hash tables for nfs4_clientid state */
+#define CLIENT_HASH_BITS                 4
+#define CLIENT_HASH_SIZE                (1 << CLIENT_HASH_BITS)
+#define CLIENT_HASH_MASK                (CLIENT_HASH_SIZE - 1)
+
+#define SESSION_HASH_SIZE	512
+
+struct cld_net;
+struct nfsd_net_cb;
+struct nfsd4_client_tracking_ops;
+
+enum nfsd_net_flag {
+	NFSD_NET_GRACE_ENDED,
+	NFSD_NET_GRACE_END_FORCED,
+	NFSD_NET_IN_GRACE,
+	NFSD_NET_SOMEBODY_RECLAIMED,
+	NFSD_NET_TRACK_RECLAIM_COMPLETES,
+	NFSD_NET_UP,
+	NFSD_NET_LOCKD_UP,
+};
+
+enum {
+	/* cache misses due only to checksum comparison failures */
+	NFSD_STATS_PAYLOAD_MISSES,
+	/* amount of memory (in bytes) currently consumed by the DRC */
+	NFSD_STATS_DRC_MEM_USAGE,
+	NFSD_STATS_RC_HITS,		/* repcache hits */
+	NFSD_STATS_RC_MISSES,		/* repcache misses */
+	NFSD_STATS_RC_NOCACHE,		/* uncached reqs */
+	NFSD_STATS_FH_STALE,		/* FH stale error */
+	NFSD_STATS_IO_READ,		/* bytes returned to read requests */
+	NFSD_STATS_IO_WRITE,		/* bytes passed in write requests */
+#ifdef CONFIG_NFSD_V4
+	NFSD_STATS_FIRST_NFS4_OP,	/* count of individual nfsv4 operations */
+	NFSD_STATS_LAST_NFS4_OP = NFSD_STATS_FIRST_NFS4_OP + LAST_NFS4_OP,
+#define NFSD_STATS_NFS4_OP(op)	(NFSD_STATS_FIRST_NFS4_OP + (op))
+#endif
+	NFSD_STATS_COUNTERS_NUM
+};
+
+/*
+ * Per-netns NFSv4 callback (backchannel) per-operation counters, indexed
+ * directly by RFC 8881 callback opcode (OP_CB_GETATTR..OP_CB_OFFLOAD).
+ */
+#define NFSD_STATS_CB_OPS_NUM	(OP_CB_OFFLOAD + 1)
+
+/*
+ * Represents a nfsd "container". With respect to nfsv4 state tracking, the
+ * fields of interest are the *_id_hashtbls and the *_name_tree. These track
+ * the nfs4_client objects by either short or long form clientid.
+ *
+ * Each nfsd_net runs a nfs4_laundromat workqueue job when necessary to clean
+ * up expired clients and delegations within the container.
+ */
+struct nfsd_net {
+	struct cld_net *cld_net;
+
+	struct cache_detail *svc_expkey_cache;
+	struct cache_detail *svc_export_cache;
+
+	struct cache_detail *idtoname_cache;
+	struct cache_detail *nametoid_cache;
+
+	struct lock_manager nfsd4_manager;
+	unsigned long flags;
+	time64_t boot_time;
+	time64_t boot_time_bt;	/* same instant in CLOCK_BOOTTIME */
+
+	struct dentry *nfsd_client_dir;
+
+	/*
+	 * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
+	 * used in reboot/reset lease grace period processing
+	 *
+	 * conf_id_hashtbl[], and conf_name_tree hold confirmed
+	 * setclientid_confirmed info.
+	 *
+	 * unconf_str_hastbl[] and unconf_name_tree hold unconfirmed
+	 * setclientid info.
+	 */
+	struct list_head *reclaim_str_hashtbl;
+	int reclaim_str_hashtbl_size;
+	struct rw_semaphore reclaim_str_hashtbl_lock;
+	struct list_head *conf_id_hashtbl;
+	struct rb_root conf_name_tree;
+	struct list_head *unconf_id_hashtbl;
+	struct rb_root unconf_name_tree;
+	struct list_head *sessionid_hashtbl;
+	/*
+	 * client_lru holds client queue ordered by nfs4_client.cl_time
+	 * for lease renewal.
+	 *
+	 * close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
+	 * for last close replay.
+	 *
+	 * reclaim_str_hashtbl[], reclaim_str_hashtbl_size are protected by
+	 * reclaim_str_hashtbl_lock.
+	 *
+	 * All of the remaining fields are protected by the client_lock.
+	 */
+	struct list_head client_lru;
+	struct list_head close_lru;
+
+	/* protects del_recall_lru and delegation hash/unhash;
+	 * nests outside client_lock */
+	spinlock_t deleg_lock ____cacheline_aligned;
+	struct list_head del_recall_lru;
+
+	/* protected by blocked_locks_lock */
+	struct list_head blocked_locks_lru;
+
+	struct delayed_work laundromat_work;
+
+	/* client_lock protects the client lru list and session hash
+	 * table; nests inside deleg_lock */
+	spinlock_t client_lock;
+
+	/* protects blocked_locks_lru */
+	spinlock_t blocked_locks_lock;
+
+	struct file *rec_file;
+	const struct nfsd4_client_tracking_ops *client_tracking_ops;
+
+	time64_t nfsd4_lease;
+	time64_t nfsd4_grace;
+
+	atomic_t nr_reclaim_complete;
+
+	seqlock_t writeverf_lock;
+	unsigned char writeverf[8];
+
+	/*
+	 * Minimum number of threads to run per pool.  If 0 then the
+	 * min == max requested number of threads.
+	 */
+	unsigned int min_threads;
+
+	u32 clientid_base;
+	u32 clientid_counter;
+	u32 clverifier_counter;
+
+	struct svc_info nfsd_info;
+#define nfsd_serv nfsd_info.serv
+
+	struct percpu_ref nfsd_net_ref;
+	struct completion nfsd_net_confirm_done;
+	struct completion nfsd_net_free_done;
+
+	/*
+	 * clientid and stateid data for construction of net unique COPY
+	 * stateids.
+	 */
+	u32		s2s_cp_cl_id;
+	struct idr	s2s_cp_stateids;
+	spinlock_t	s2s_cp_lock;
+	atomic_t	pending_async_copies;
+
+	/*
+	 * Version information
+	 */
+	bool nfsd_versions[NFSD_MAXVERS + 1];
+	bool nfsd4_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1];
+
+	/*
+	 * Duplicate reply cache
+	 */
+	struct nfsd_drc_bucket   *drc_hashtbl;
+
+	/* max number of entries allowed in the cache */
+	unsigned int             max_drc_entries;
+
+	/* number of significant bits in the hash value */
+	unsigned int             maskbits;
+	unsigned int             drc_hashsize;
+
+	/*
+	 * Stats and other tracking of on the duplicate reply cache.
+	 * The longest_chain* fields are modified with only the per-bucket
+	 * cache lock, which isn't really safe and should be fixed if we want
+	 * these statistics to be completely accurate.
+	 */
+
+	/* total number of entries */
+	atomic_t                 num_drc_entries;
+
+	/* Per-netns stats counters */
+	struct percpu_counter    counter[NFSD_STATS_COUNTERS_NUM];
+
+#ifdef CONFIG_NFSD_V4
+	/* Per-netns NFSv4 callback (backchannel) per-operation counters */
+	struct percpu_counter    cb_counter[NFSD_STATS_CB_OPS_NUM];
+#endif
+
+	/* sunrpc svc stats */
+	struct svc_stat          nfsd_svcstats;
+
+	/* longest hash chain seen */
+	unsigned int             longest_chain;
+
+	/* size of cache when we saw the longest hash chain */
+	unsigned int             longest_chain_cachesize;
+
+	struct shrinker		*nfsd_reply_cache_shrinker;
+
+	/* tracking server-to-server copy mounts */
+	spinlock_t              nfsd_ssc_lock;
+	struct list_head        nfsd_ssc_mount_list;
+	wait_queue_head_t       nfsd_ssc_waitq;
+
+	/* utsname taken from the process that starts the server */
+	char			nfsd_name[UNX_MAXNODENAME+1];
+
+	spinlock_t		fcache_dispose_lock;
+	struct list_head	fcache_dispose_list;
+
+	siphash_key_t		siphash_key;
+
+	atomic_t		nfs4_client_count;
+	int			nfs4_max_clients;
+
+	atomic_t		nfsd_courtesy_clients;
+	struct shrinker		*nfsd_client_shrinker;
+	struct work_struct	nfsd_shrinker_work;
+
+	/* last time an admin-revoke happened for NFSv4.0 */
+	time64_t		nfs40_last_revoke;
+
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	/* Local clients to be invalidated when net is shut down */
+	spinlock_t              local_clients_lock;
+	struct list_head	local_clients;
+#endif
+	siphash_key_t		*fh_key;
+
+	struct nfsd_net_cb	*nfsd_cb;
+};
+
+/* Simple check to find out if a given net was properly initialized */
+#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
+
+extern bool nfsd_support_version(int vers);
+extern unsigned int nfsd_net_id;
+
+bool nfsd_net_try_get(struct net *net);
+void nfsd_net_put(struct net *net);
+
+void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn);
+void nfsd_reset_write_verifier(struct nfsd_net *nn);
+#endif /* __NFSD_NETNS_H__ */
diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
new file mode 100644
index 000000000..190f5a001
--- /dev/null
+++ b/fs/nfsd/nfs2acl.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 2 NFSACL requests.
+ *
+ * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+#include "nfsd.h"
+/* FIXME: nfsacl.h is a broken header */
+#include <linux/nfsacl.h>
+#include <linux/gfp.h>
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsacld_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get the Access and/or Default ACL of a file.
+ */
+static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct posix_acl *acl;
+	struct inode *inode;
+	svc_fh *fh;
+
+	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	if (argp->mask & ~NFS_ACL_MASK) {
+		resp->status = nfserr_io;
+		goto out;
+	}
+	resp->mask = argp->mask;
+
+	resp->status = fh_getattr(fh, &resp->stat);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
+		acl = get_inode_acl(inode, ACL_TYPE_ACCESS);
+		if (acl == NULL) {
+			/* Solaris returns the inode's minimum ACL. */
+			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		}
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_access = acl;
+	}
+	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
+		/* Check how Solaris handles requests for the Default ACL
+		   of a non-directory! */
+		acl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_default = acl;
+	}
+
+	/* resp->acl_{access,default} are released in nfssvc_release_getacl. */
+out:
+	return rpc_success;
+
+fail:
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+	resp->acl_access = NULL;
+	resp->acl_default = NULL;
+	goto out;
+}
+
+/*
+ * Set the Access and/or Default ACL of a file.
+ */
+static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	struct inode *inode;
+	svc_fh *fh;
+	int error;
+
+	dprintk("nfsd: SETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	error = fh_want_write(fh);
+	if (error)
+		goto out_errno;
+
+	inode_lock(inode);
+
+	error = 0;
+	if (argp->mask & NFS_ACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_ACCESS, argp->acl_access);
+		if (error)
+			goto out_drop_lock;
+	}
+	if (argp->mask & NFS_DFACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_DEFAULT, argp->acl_default);
+		if (error)
+			goto out_drop_lock;
+	}
+
+	inode_unlock(inode);
+
+	fh_drop_write(fh);
+
+	resp->status = fh_getattr(fh, &resp->stat);
+
+out:
+	/* argp->acl_{access,default} are released in nfsaclsvc_release_setacl. */
+	return rpc_success;
+
+out_drop_lock:
+	inode_unlock(inode);
+	fh_drop_write(fh);
+out_errno:
+	resp->status = nfserrno(error);
+	goto out;
+}
+
+/*
+ * Check file attributes
+ */
+static __be32 nfsacld_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Check file access
+ */
+static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessargs *argp = rqstp->rq_argp;
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
+			SVCFH_fmt(&argp->fh),
+			argp->access);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->access = argp->access;
+	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * XDR decode functions
+ */
+
+static bool
+nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_fhandle(xdr, &argp->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->mask) < 0)
+		return false;
+
+	return true;
+}
+
+static bool
+nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_fhandle(xdr, &argp->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->mask) < 0)
+		return false;
+	if (argp->mask & ~NFS_ACL_MASK)
+		return false;
+	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_ACL) ?
+				   &argp->acl_access : NULL))
+		return false;
+	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_DFACL) ?
+				   &argp->acl_default : NULL))
+		return false;
+
+	return true;
+}
+
+static bool
+nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_accessargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->access) < 0)
+		return false;
+
+	return true;
+}
+
+/*
+ * XDR encode functions
+ */
+
+/* GETACL */
+static bool
+nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct dentry *dentry = resp->fh.fh_dentry;
+	struct inode *inode;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		inode = d_inode(dentry);
+		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->mask) < 0)
+			return false;
+		if (!nfs_stream_encode_acl(xdr, inode, resp->acl_access,
+					   resp->mask & NFS_ACL, 0))
+			return false;
+		if (!nfs_stream_encode_acl(xdr, inode, resp->acl_default,
+					   resp->mask & NFS_DFACL, NFS_ACL_DEFAULT))
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+/* ACCESS */
+static bool
+nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->access) < 0)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+/*
+ * XDR release functions
+ */
+static void nfsaclsvc_release_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+}
+
+static void nfsaclsvc_release_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+static void nfsaclsvc_release_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(argp->acl_access);
+	posix_acl_release(argp->acl_default);
+}
+
+#define ST 1		/* status*/
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
+
+static const struct svc_procedure nfsd_acl_procedures2[5] = {
+	[ACLPROC2_NULL] = {
+		.pc_func = nfsacld_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+		.pc_name = "NULL",
+	},
+	[ACLPROC2_GETACL] = {
+		.pc_func = nfsacld_proc_getacl,
+		.pc_decode = nfsaclsvc_decode_getaclargs,
+		.pc_encode = nfsaclsvc_encode_getaclres,
+		.pc_release = nfsaclsvc_release_getacl,
+		.pc_argsize = sizeof(struct nfsd3_getaclargs),
+		.pc_argzero = sizeof(struct nfsd3_getaclargs),
+		.pc_ressize = sizeof(struct nfsd3_getaclres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+2*(1+ACL),
+		.pc_name = "GETACL",
+	},
+	[ACLPROC2_SETACL] = {
+		.pc_func = nfsacld_proc_setacl,
+		.pc_decode = nfsaclsvc_decode_setaclargs,
+		.pc_encode = nfssvc_encode_attrstatres,
+		.pc_release = nfsaclsvc_release_setacl,
+		.pc_argsize = sizeof(struct nfsd3_setaclargs),
+		.pc_argzero = sizeof(struct nfsd3_setaclargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "SETACL",
+	},
+	[ACLPROC2_GETATTR] = {
+		.pc_func = nfsacld_proc_getattr,
+		.pc_decode = nfssvc_decode_fhandleargs,
+		.pc_encode = nfssvc_encode_attrstatres,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "GETATTR",
+	},
+	[ACLPROC2_ACCESS] = {
+		.pc_func = nfsacld_proc_access,
+		.pc_decode = nfsaclsvc_decode_accessargs,
+		.pc_encode = nfsaclsvc_encode_accessres,
+		.pc_release = nfsaclsvc_release_access,
+		.pc_argsize = sizeof(struct nfsd3_accessargs),
+		.pc_argzero = sizeof(struct nfsd3_accessargs),
+		.pc_ressize = sizeof(struct nfsd3_accessres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT+1,
+		.pc_name = "SETATTR",
+	},
+};
+
+const struct svc_version nfsd_acl_version2 = {
+	.vs_vers	= 2,
+	.vs_nproc	= ARRAY_SIZE(nfsd_acl_procedures2),
+	.vs_proc	= nfsd_acl_procedures2,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c
new file mode 100644
index 000000000..6b6b289db
--- /dev/null
+++ b/fs/nfsd/nfs3acl.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 3 NFSACL requests.
+ *
+ * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+#include "nfsd.h"
+/* FIXME: nfsacl.h is a broken header */
+#include <linux/nfsacl.h>
+#include <linux/gfp.h>
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd3_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get the Access and/or Default ACL of a file.
+ */
+static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct posix_acl *acl;
+	struct inode *inode;
+	svc_fh *fh;
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	if (argp->mask & ~NFS_ACL_MASK) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	resp->mask = argp->mask;
+
+	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
+		acl = get_inode_acl(inode, ACL_TYPE_ACCESS);
+		if (acl == NULL) {
+			/* Solaris returns the inode's minimum ACL. */
+			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		}
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_access = acl;
+	}
+	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
+		/* Check how Solaris handles requests for the Default ACL
+		   of a non-directory! */
+		acl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_default = acl;
+	}
+
+	/* resp->acl_{access,default} are released in nfs3svc_release_getacl. */
+out:
+	return rpc_success;
+
+fail:
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+	resp->acl_access = NULL;
+	resp->acl_default = NULL;
+	goto out;
+}
+
+/*
+ * Set the Access and/or Default ACL of a file.
+ */
+static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+	struct inode *inode;
+	svc_fh *fh;
+	int error;
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	error = fh_want_write(fh);
+	if (error)
+		goto out_errno;
+
+	inode_lock(inode);
+
+	error = 0;
+	if (argp->mask & NFS_ACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_ACCESS, argp->acl_access);
+		if (error)
+			goto out_drop_lock;
+	}
+	if (argp->mask & NFS_DFACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_DEFAULT, argp->acl_default);
+	}
+
+out_drop_lock:
+	inode_unlock(inode);
+	fh_drop_write(fh);
+out_errno:
+	resp->status = nfserrno(error);
+out:
+	/* argp->acl_{access,default} are released in nfs3svc_release_setacl. */
+	return rpc_success;
+}
+
+/*
+ * XDR decode functions
+ */
+
+static bool
+nfs3svc_decode_getaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_getaclargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->mask) < 0)
+		return false;
+
+	return true;
+}
+
+static bool
+nfs3svc_decode_setaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &argp->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &argp->mask) < 0)
+		return false;
+	if (argp->mask & ~NFS_ACL_MASK)
+		return false;
+	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_ACL) ?
+				   &argp->acl_access : NULL))
+		return false;
+	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_DFACL) ?
+				   &argp->acl_default : NULL))
+		return false;
+
+	return true;
+}
+
+/*
+ * XDR encode functions
+ */
+
+/* GETACL */
+static bool
+nfs3svc_encode_getaclres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct dentry *dentry = resp->fh.fh_dentry;
+	struct inode *inode;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		inode = d_inode(dentry);
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->mask) < 0)
+			return false;
+
+		if (!nfs_stream_encode_acl(xdr, inode, resp->acl_access,
+					   resp->mask & NFS_ACL, 0))
+			return false;
+		if (!nfs_stream_encode_acl(xdr, inode, resp->acl_default,
+					   resp->mask & NFS_DFACL,
+					   NFS_ACL_DEFAULT))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* SETACL */
+static bool
+nfs3svc_encode_setaclres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
+		svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh);
+}
+
+/*
+ * XDR release functions
+ */
+static void nfs3svc_release_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+}
+
+static void nfs3svc_release_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(argp->acl_access);
+	posix_acl_release(argp->acl_default);
+}
+
+#define ST 1		/* status*/
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
+
+static const struct svc_procedure nfsd_acl_procedures3[3] = {
+	[ACLPROC3_NULL] = {
+		.pc_func = nfsd3_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+		.pc_name = "NULL",
+	},
+	[ACLPROC3_GETACL] = {
+		.pc_func = nfsd3_proc_getacl,
+		.pc_decode = nfs3svc_decode_getaclargs,
+		.pc_encode = nfs3svc_encode_getaclres,
+		.pc_release = nfs3svc_release_getacl,
+		.pc_argsize = sizeof(struct nfsd3_getaclargs),
+		.pc_argzero = sizeof(struct nfsd3_getaclargs),
+		.pc_ressize = sizeof(struct nfsd3_getaclres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+2*(1+ACL),
+		.pc_name = "GETACL",
+	},
+	[ACLPROC3_SETACL] = {
+		.pc_func = nfsd3_proc_setacl,
+		.pc_decode = nfs3svc_decode_setaclargs,
+		.pc_encode = nfs3svc_encode_setaclres,
+		.pc_release = nfs3svc_release_setacl,
+		.pc_argsize = sizeof(struct nfsd3_setaclargs),
+		.pc_argzero = sizeof(struct nfsd3_setaclargs),
+		.pc_ressize = sizeof(struct nfsd3_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT,
+		.pc_name = "SETACL",
+	},
+};
+
+const struct svc_version nfsd_acl_version3 = {
+	.vs_vers	= 3,
+	.vs_nproc	= ARRAY_SIZE(nfsd_acl_procedures3),
+	.vs_proc	= nfsd_acl_procedures3,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
+
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
new file mode 100644
index 000000000..0904d953d
--- /dev/null
+++ b/fs/nfsd/nfs3proc.c
@@ -0,0 +1,1117 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 3 NFS requests.
+ *
+ * Copyright (C) 1996, 1997, 1998 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/magic.h>
+#include <linux/namei.h>
+
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static int	nfs3_ftypes[] = {
+	0,			/* NF3NON */
+	S_IFREG,		/* NF3REG */
+	S_IFDIR,		/* NF3DIR */
+	S_IFBLK,		/* NF3BLK */
+	S_IFCHR,		/* NF3CHR */
+	S_IFLNK,		/* NF3LNK */
+	S_IFSOCK,		/* NF3SOCK */
+	S_IFIFO,		/* NF3FIFO */
+};
+
+/*
+ * Reject a client-supplied atime or mtime whose nanoseconds field is out
+ * of range. Such a value is well-formed on the wire but is not a valid
+ * timespec64, and storing it verbatim can corrupt on-disk timestamps.
+ * tv_nsec is a long, so it is cast to unsigned long (the same width) to
+ * catch both an over-large value and one that became negative when an
+ * out-of-range u32 wire nseconds was assigned to a 32-bit long.
+ */
+static bool nfsd3_time_in_range(const struct iattr *iap)
+{
+	if ((iap->ia_valid & ATTR_ATIME_SET) &&
+	    (unsigned long)iap->ia_atime.tv_nsec >= NSEC_PER_SEC)
+		return false;
+	if ((iap->ia_valid & ATTR_MTIME_SET) &&
+	    (unsigned long)iap->ia_mtime.tv_nsec >= NSEC_PER_SEC)
+		return false;
+	return true;
+}
+
+static __be32 nfsd3_map_status(__be32 status)
+{
+	switch (status) {
+	case nfs_ok:
+		break;
+	case nfserr_nofilehandle:
+		status = nfserr_badhandle;
+		break;
+	case nfserr_wrongsec:
+	case nfserr_file_open:
+		status = nfserr_acces;
+		break;
+	case nfserr_symlink_not_dir:
+		status = nfserr_notdir;
+		break;
+	case nfserr_symlink:
+	case nfserr_wrong_type:
+		status = nfserr_inval;
+		break;
+	}
+	return status;
+}
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd3_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get a file's attributes
+ */
+static __be32
+nfsd3_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	trace_nfsd_vfs_getattr(rqstp, &argp->fh);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Set a file's attributes
+ */
+static __be32
+nfsd3_proc_setattr(struct svc_rqst *rqstp)
+{
+	struct nfsd3_sattrargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+	const struct timespec64 *guardtime = NULL;
+
+	dprintk("nfsd: SETATTR(3)  %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	if (argp->check_guard)
+		guardtime = &argp->guardtime;
+	resp->status = nfsd_setattr(rqstp, &resp->fh, &attrs, guardtime);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Look up a path name component
+ */
+static __be32
+nfsd3_proc_lookup(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres  *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LOOKUP(3)   %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+
+	resp->status = nfsd_lookup(rqstp, &resp->dirfh,
+				   argp->name, argp->len,
+				   &resp->fh);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Check file access
+ */
+static __be32
+nfsd3_proc_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessargs *argp = rqstp->rq_argp;
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: ACCESS(3)   %s 0x%x\n",
+				SVCFH_fmt(&argp->fh),
+				argp->access);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->access = argp->access;
+	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Read a symlink.
+ */
+static __be32
+nfsd3_proc_readlink(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: READLINK(3) %s\n", SVCFH_fmt(&argp->fh));
+
+	/* Read the symlink. */
+	fh_copy(&resp->fh, &argp->fh);
+	resp->len = NFS3_MAXPATHLEN;
+	resp->pages = rqstp->rq_next_page++;
+	resp->status = nfsd_readlink(rqstp, &resp->fh,
+				     page_address(*resp->pages), &resp->len);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a file.
+ */
+static __be32
+nfsd3_proc_read(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readargs *argp = rqstp->rq_argp;
+	struct nfsd3_readres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: READ(3) %s %lu bytes at %Lu\n",
+				SVCFH_fmt(&argp->fh),
+				(unsigned long) argp->count,
+				(unsigned long long) argp->offset);
+
+	argp->count = min_t(u32, argp->count, svc_max_payload(rqstp));
+	argp->count = min_t(u32, argp->count, rqstp->rq_res.buflen);
+	if (argp->offset > (u64)OFFSET_MAX)
+		argp->offset = (u64)OFFSET_MAX;
+	if (argp->offset + argp->count > (u64)OFFSET_MAX)
+		argp->count = (u64)OFFSET_MAX - argp->offset;
+
+	resp->pages = rqstp->rq_next_page;
+
+	/* Obtain buffer pointer for payload.
+	 * 1 (status) + 22 (post_op_attr) + 1 (count) + 1 (eof)
+	 * + 1 (xdr opaque byte count) = 26
+	 */
+	resp->count = argp->count;
+	svc_reserve_auth(rqstp, ((1 + NFS3_POST_OP_ATTR_WORDS + 3) << 2) +
+			 resp->count + 4);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
+				 &resp->count, &resp->eof);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Write data to a file
+ */
+static __be32
+nfsd3_proc_write(struct svc_rqst *rqstp)
+{
+	struct nfsd3_writeargs *argp = rqstp->rq_argp;
+	struct nfsd3_writeres *resp = rqstp->rq_resp;
+	unsigned long cnt = argp->len;
+
+	dprintk("nfsd: WRITE(3)    %s %d bytes at %Lu%s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				(unsigned long long) argp->offset,
+				argp->stable ? " stable" : "");
+
+	resp->status = nfserr_fbig;
+	if (argp->offset > (u64)OFFSET_MAX ||
+	    argp->offset + argp->len > (u64)OFFSET_MAX)
+		return rpc_success;
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->committed = argp->stable;
+	resp->status = nfsd_write(rqstp, &resp->fh, argp->offset,
+				  &argp->payload, &cnt,
+				  resp->committed, resp->verf);
+	resp->count = cnt;
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Implement NFSv3's unchecked, guarded, and exclusive CREATE
+ * semantics for regular files. Except for the created file,
+ * this operation is stateless on the server.
+ *
+ * Upon return, caller must release @fhp and @resfhp.
+ */
+static __be32
+nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct svc_fh *resfhp, struct nfsd3_createargs *argp)
+{
+	struct iattr *iap = &argp->attrs;
+	struct dentry *parent, *child;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= iap,
+	};
+	__u32 v_mtime, v_atime;
+	struct inode *inode;
+	__be32 status;
+	int host_err;
+
+	trace_nfsd_vfs_create(rqstp, fhp, S_IFREG, argp->name, argp->len);
+
+	if (!nfsd3_time_in_range(iap))
+		return nfserr_inval;
+	if (name_is_dot_dotdot(argp->name, argp->len))
+		return nfserr_exist;
+	if (!(iap->ia_valid & ATTR_MODE))
+		iap->ia_mode = 0;
+
+	status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (status != nfs_ok)
+		return status;
+
+	parent = fhp->fh_dentry;
+	inode = d_inode(parent);
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		return nfserrno(host_err);
+
+	child = start_creating(&nop_mnt_idmap, parent,
+			       &QSTR_LEN(argp->name, argp->len));
+	if (IS_ERR(child)) {
+		status = nfserrno(PTR_ERR(child));
+		goto out_write;
+	}
+
+	if (d_really_is_negative(child)) {
+		status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+		if (status != nfs_ok)
+			goto out;
+	}
+
+	status = fh_compose(resfhp, fhp->fh_export, child, fhp);
+	if (status != nfs_ok)
+		goto out;
+
+	v_mtime = 0;
+	v_atime = 0;
+	if (argp->createmode == NFS3_CREATE_EXCLUSIVE) {
+		u32 *verifier = (u32 *)argp->verf;
+
+		/*
+		 * Solaris 7 gets confused (bugid 4218508) if these have
+		 * the high bit set, as do xfs filesystems without the
+		 * "bigtime" feature. So just clear the high bits.
+		 */
+		v_mtime = verifier[0] & 0x7fffffff;
+		v_atime = verifier[1] & 0x7fffffff;
+	}
+
+	if (d_really_is_positive(child)) {
+		status = nfs_ok;
+
+		switch (argp->createmode) {
+		case NFS3_CREATE_UNCHECKED:
+			if (!d_is_reg(child))
+				break;
+			iap->ia_valid &= ATTR_SIZE;
+			goto set_attr;
+		case NFS3_CREATE_GUARDED:
+			status = nfserr_exist;
+			break;
+		case NFS3_CREATE_EXCLUSIVE:
+			if (inode_get_mtime_sec(d_inode(child)) == v_mtime &&
+			    inode_get_atime_sec(d_inode(child)) == v_atime &&
+			    d_inode(child)->i_size == 0) {
+				break;
+			}
+			status = nfserr_exist;
+		}
+		goto out;
+	}
+
+	if (!IS_POSIXACL(inode))
+		iap->ia_mode &= ~current_umask();
+
+	status = fh_fill_pre_attrs(fhp);
+	if (status != nfs_ok)
+		goto out;
+	host_err = vfs_create(&nop_mnt_idmap, child, iap->ia_mode, NULL);
+	if (host_err < 0) {
+		status = nfserrno(host_err);
+		goto out;
+	}
+	fh_fill_post_attrs(fhp);
+
+	/* A newly created file already has a file size of zero. */
+	if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+		iap->ia_valid &= ~ATTR_SIZE;
+	if (argp->createmode == NFS3_CREATE_EXCLUSIVE) {
+		iap->ia_valid = ATTR_MTIME | ATTR_ATIME |
+				ATTR_MTIME_SET | ATTR_ATIME_SET;
+		iap->ia_mtime.tv_sec = v_mtime;
+		iap->ia_atime.tv_sec = v_atime;
+		iap->ia_mtime.tv_nsec = 0;
+		iap->ia_atime.tv_nsec = 0;
+	}
+
+set_attr:
+	status = nfsd_create_setattr(rqstp, fhp, resfhp, &attrs);
+
+out:
+	end_creating(child);
+out_write:
+	fh_drop_write(fhp);
+	return status;
+}
+
+static __be32
+nfsd3_proc_create(struct svc_rqst *rqstp)
+{
+	struct nfsd3_createargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+	svc_fh *dirfhp, *newfhp;
+
+	dirfhp = fh_copy(&resp->dirfh, &argp->fh);
+	newfhp = fh_init(&resp->fh, NFS3_FHSIZE);
+
+	resp->status = nfsd3_create_file(rqstp, dirfhp, newfhp, argp);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Make directory. This operation is not idempotent.
+ */
+static __be32
+nfsd3_proc_mkdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_createargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+
+	argp->attrs.ia_valid &= ~ATTR_SIZE;
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
+				   &attrs, S_IFDIR, 0, &resp->fh);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_symlink(struct svc_rqst *rqstp)
+{
+	struct nfsd3_symlinkargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	if (argp->tlen == 0) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	if (argp->tlen > NFS3_MAXPATHLEN) {
+		resp->status = nfserr_nametoolong;
+		goto out;
+	}
+
+	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
+						page_address(rqstp->rq_arg.pages[0]),
+						argp->tlen);
+	if (IS_ERR(argp->tname)) {
+		resp->status = nfserrno(PTR_ERR(argp->tname));
+		goto out;
+	}
+
+	fh_copy(&resp->dirfh, &argp->ffh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+	resp->status = nfsd_symlink(rqstp, &resp->dirfh, argp->fname,
+				    argp->flen, argp->tname, &attrs, &resp->fh);
+	kfree(argp->tname);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Make socket/fifo/device.
+ */
+static __be32
+nfsd3_proc_mknod(struct svc_rqst *rqstp)
+{
+	struct nfsd3_mknodargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres  *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+	int type;
+	dev_t	rdev = 0;
+
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+
+	if (argp->ftype == NF3CHR || argp->ftype == NF3BLK) {
+		rdev = MKDEV(argp->major, argp->minor);
+		if (MAJOR(rdev) != argp->major ||
+		    MINOR(rdev) != argp->minor) {
+			resp->status = nfserr_inval;
+			goto out;
+		}
+	} else if (argp->ftype != NF3SOCK && argp->ftype != NF3FIFO) {
+		resp->status = nfserr_badtype;
+		goto out;
+	}
+
+	if (!nfsd3_time_in_range(&argp->attrs)) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+
+	type = nfs3_ftypes[argp->ftype];
+	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
+				   &attrs, type, rdev, &resp->fh);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Remove file/fifo/socket etc.
+ */
+static __be32
+nfsd3_proc_remove(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	/* Unlink. -S_IFDIR means file must not be a directory */
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_unlink(rqstp, &resp->fh, -S_IFDIR,
+				   argp->name, argp->len);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Remove a directory
+ */
+static __be32
+nfsd3_proc_rmdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_unlink(rqstp, &resp->fh, S_IFDIR,
+				   argp->name, argp->len);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_rename(struct svc_rqst *rqstp)
+{
+	struct nfsd3_renameargs *argp = rqstp->rq_argp;
+	struct nfsd3_renameres *resp = rqstp->rq_resp;
+
+	fh_copy(&resp->ffh, &argp->ffh);
+	fh_copy(&resp->tfh, &argp->tfh);
+	resp->status = nfsd_rename(rqstp, &resp->ffh, argp->fname, argp->flen,
+				   &resp->tfh, argp->tname, argp->tlen);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_link(struct svc_rqst *rqstp)
+{
+	struct nfsd3_linkargs *argp = rqstp->rq_argp;
+	struct nfsd3_linkres  *resp = rqstp->rq_resp;
+
+	fh_copy(&resp->fh,  &argp->ffh);
+	fh_copy(&resp->tfh, &argp->tfh);
+	resp->status = nfsd_link(rqstp, &resp->tfh, argp->tname, argp->tlen,
+				 &resp->fh);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+static void nfsd3_init_dirlist_pages(struct svc_rqst *rqstp,
+				     struct nfsd3_readdirres *resp,
+				     u32 count)
+{
+	struct xdr_buf *buf = &resp->dirlist;
+	struct xdr_stream *xdr = &resp->xdr;
+	unsigned int sendbuf = min_t(unsigned int, rqstp->rq_res.buflen,
+				     svc_max_payload(rqstp));
+
+	memset(buf, 0, sizeof(*buf));
+
+	/* Reserve room for the NULL ptr & eof flag (-2 words) */
+	buf->buflen = clamp(count, (u32)(XDR_UNIT * 2), sendbuf);
+	buf->buflen -= XDR_UNIT * 2;
+	buf->pages = rqstp->rq_next_page;
+	rqstp->rq_next_page += (buf->buflen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+	xdr_init_encode_pages(xdr, buf);
+}
+
+/*
+ * Read a portion of a directory.
+ */
+static __be32
+nfsd3_proc_readdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
+	loff_t		offset;
+
+	trace_nfsd_vfs_readdir(rqstp, &argp->fh, argp->count, argp->cookie);
+
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->common.err = nfs_ok;
+	resp->cookie_offset = 0;
+	resp->rqstp = rqstp;
+	offset = argp->cookie;
+	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
+				    &resp->common, nfs3svc_encode_entry3);
+	memcpy(resp->verf, argp->verf, 8);
+	nfs3svc_encode_cookie3(resp, offset);
+
+	/* Recycle only pages that were part of the reply */
+	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
+
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a directory, including file handles and attrs.
+ * For now, we choose to ignore the dircount parameter.
+ */
+static __be32
+nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
+	loff_t	offset;
+
+	trace_nfsd_vfs_readdir(rqstp, &argp->fh, argp->count, argp->cookie);
+
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->common.err = nfs_ok;
+	resp->cookie_offset = 0;
+	resp->rqstp = rqstp;
+	offset = argp->cookie;
+
+	resp->status = fh_verify(rqstp, &resp->fh, S_IFDIR, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	if (resp->fh.fh_export->ex_flags & NFSEXP_NOREADDIRPLUS) {
+		resp->status = nfserr_notsupp;
+		goto out;
+	}
+
+	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
+				    &resp->common, nfs3svc_encode_entryplus3);
+	memcpy(resp->verf, argp->verf, 8);
+	nfs3svc_encode_cookie3(resp, offset);
+
+	/* Recycle only pages that were part of the reply */
+	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
+
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Get file system stats
+ */
+static __be32
+nfsd3_proc_fsstat(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
+
+	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats, 0);
+	fh_put(&argp->fh);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Get file system info
+ */
+static __be32
+nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
+	u32	max_blocksize = svc_max_payload(rqstp);
+
+	dprintk("nfsd: FSINFO(3)   %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	resp->f_rtmax  = max_blocksize;
+	resp->f_rtpref = max_blocksize;
+	resp->f_rtmult = PAGE_SIZE;
+	resp->f_wtmax  = max_blocksize;
+	resp->f_wtpref = max_blocksize;
+	resp->f_wtmult = PAGE_SIZE;
+	resp->f_dtpref = max_blocksize;
+	resp->f_maxfilesize = ~(u32) 0;
+	resp->f_properties = NFS3_FSF_DEFAULT;
+
+	resp->status = fh_verify(rqstp, &argp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+
+	/* Check special features of the file system. May request
+	 * different read/write sizes for file systems known to have
+	 * problems with large blocks */
+	if (resp->status == nfs_ok) {
+		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+
+		/* Note that we don't care for remote fs's here */
+		if (sb->s_magic == MSDOS_SUPER_MAGIC) {
+			resp->f_properties = NFS3_FSF_BILLYBOY;
+		}
+		resp->f_maxfilesize = sb->s_maxbytes;
+	}
+
+	fh_put(&argp->fh);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Get pathconf info for the specified file
+ */
+static __be32
+nfsd3_proc_pathconf(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: PATHCONF(3) %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	/* Set default pathconf */
+	resp->p_link_max = 255;		/* at least */
+	resp->p_name_max = 255;		/* at least */
+	resp->p_no_trunc = 0;
+	resp->p_chown_restricted = 1;
+	resp->p_case_insensitive = false;
+	resp->p_case_preserving = true;
+
+	resp->status = fh_verify(rqstp, &argp->fh, 0, NFSD_MAY_NOP);
+
+	if (resp->status == nfs_ok) {
+		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+		int err;
+
+		if (sb->s_magic == EXT2_SUPER_MAGIC) {
+			resp->p_link_max = EXT2_LINK_MAX;
+			resp->p_name_max = EXT2_NAME_LEN;
+		}
+
+		err = nfsd_get_case_info(argp->fh.fh_dentry,
+					 &resp->p_case_insensitive,
+					 &resp->p_case_preserving);
+		/*
+		 * RFC 1813 lists NFS3ERR_STALE, NFS3ERR_BADHANDLE, and
+		 * NFS3ERR_SERVERFAULT as the only PATHCONF errors.
+		 */
+		switch (err) {
+		case 0:
+		case -EOPNOTSUPP:
+			/* Both arms leave the output booleans valid. */
+			break;
+		case -EACCES:
+		case -EPERM:
+			/*
+			 * Policy denied the query. Report STALE so the
+			 * handle is unusable without implying a server
+			 * malfunction.
+			 */
+			resp->status = nfserr_stale;
+			break;
+		case -ESTALE:
+			resp->status = nfserr_stale;
+			break;
+		default:
+			resp->status = nfserr_serverfault;
+			break;
+		}
+	}
+
+	fh_put(&argp->fh);
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Commit a file (range) to stable storage.
+ */
+static __be32
+nfsd3_proc_commit(struct svc_rqst *rqstp)
+{
+	struct nfsd3_commitargs *argp = rqstp->rq_argp;
+	struct nfsd3_commitres *resp = rqstp->rq_resp;
+	struct nfsd_file *nf;
+
+	dprintk("nfsd: COMMIT(3)   %s %u@%Lu\n",
+				SVCFH_fmt(&argp->fh),
+				argp->count,
+				(unsigned long long) argp->offset);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_file_acquire_gc(rqstp, &resp->fh, NFSD_MAY_WRITE |
+					    NFSD_MAY_NOT_BREAK_LEASE, &nf);
+	if (resp->status)
+		goto out;
+	resp->status = nfsd_commit(rqstp, &resp->fh, nf, argp->offset,
+				   argp->count, resp->verf);
+	nfsd_file_put(nf);
+out:
+	resp->status = nfsd3_map_status(resp->status);
+	return rpc_success;
+}
+
+
+/*
+ * NFSv3 Server procedures.
+ * Only the results of non-idempotent operations are cached.
+ */
+#define nfs3svc_encode_attrstatres	nfs3svc_encode_attrstat
+#define nfs3svc_encode_wccstatres	nfs3svc_encode_wccstat
+#define nfsd3_mkdirargs			nfsd3_createargs
+#define nfsd3_readdirplusargs		nfsd3_readdirargs
+#define nfsd3_fhandleargs		nfsd_fhandle
+#define nfsd3_attrstatres		nfsd3_attrstat
+#define nfsd3_wccstatres		nfsd3_attrstat
+#define nfsd3_createres			nfsd3_diropres
+
+#define ST 1		/* status*/
+#define FH 17		/* filehandle with length */
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define WC (7+pAT)	/* WCC attributes */
+
+static const struct svc_procedure nfsd_procedures3[22] = {
+	[NFS3PROC_NULL] = {
+		.pc_func = nfsd3_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+		.pc_name = "NULL",
+	},
+	[NFS3PROC_GETATTR] = {
+		.pc_func = nfsd3_proc_getattr,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_getattrres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd3_attrstatres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "GETATTR",
+	},
+	[NFS3PROC_SETATTR] = {
+		.pc_func = nfsd3_proc_setattr,
+		.pc_decode = nfs3svc_decode_sattrargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_sattrargs),
+		.pc_argzero = sizeof(struct nfsd3_sattrargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+		.pc_name = "SETATTR",
+	},
+	[NFS3PROC_LOOKUP] = {
+		.pc_func = nfsd3_proc_lookup,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_lookupres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_argzero = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_diropres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+FH+pAT+pAT,
+		.pc_name = "LOOKUP",
+	},
+	[NFS3PROC_ACCESS] = {
+		.pc_func = nfsd3_proc_access,
+		.pc_decode = nfs3svc_decode_accessargs,
+		.pc_encode = nfs3svc_encode_accessres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_accessargs),
+		.pc_argzero = sizeof(struct nfsd3_accessargs),
+		.pc_ressize = sizeof(struct nfsd3_accessres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+1,
+		.pc_name = "ACCESS",
+	},
+	[NFS3PROC_READLINK] = {
+		.pc_func = nfsd3_proc_readlink,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_readlinkres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd3_readlinkres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+1+NFS3_MAXPATHLEN/4,
+		.pc_name = "READLINK",
+	},
+	[NFS3PROC_READ] = {
+		.pc_func = nfsd3_proc_read,
+		.pc_decode = nfs3svc_decode_readargs,
+		.pc_encode = nfs3svc_encode_readres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readargs),
+		.pc_argzero = sizeof(struct nfsd3_readargs),
+		.pc_ressize = sizeof(struct nfsd3_readres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+4+NFSSVC_MAXBLKSIZE/4,
+		.pc_name = "READ",
+	},
+	[NFS3PROC_WRITE] = {
+		.pc_func = nfsd3_proc_write,
+		.pc_decode = nfs3svc_decode_writeargs,
+		.pc_encode = nfs3svc_encode_writeres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_writeargs),
+		.pc_argzero = sizeof(struct nfsd3_writeargs),
+		.pc_ressize = sizeof(struct nfsd3_writeres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC+4,
+		.pc_name = "WRITE",
+	},
+	[NFS3PROC_CREATE] = {
+		.pc_func = nfsd3_proc_create,
+		.pc_decode = nfs3svc_decode_createargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_createargs),
+		.pc_argzero = sizeof(struct nfsd3_createargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+		.pc_name = "CREATE",
+	},
+	[NFS3PROC_MKDIR] = {
+		.pc_func = nfsd3_proc_mkdir,
+		.pc_decode = nfs3svc_decode_mkdirargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_mkdirargs),
+		.pc_argzero = sizeof(struct nfsd3_mkdirargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+		.pc_name = "MKDIR",
+	},
+	[NFS3PROC_SYMLINK] = {
+		.pc_func = nfsd3_proc_symlink,
+		.pc_decode = nfs3svc_decode_symlinkargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_symlinkargs),
+		.pc_argzero = sizeof(struct nfsd3_symlinkargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+		.pc_name = "SYMLINK",
+	},
+	[NFS3PROC_MKNOD] = {
+		.pc_func = nfsd3_proc_mknod,
+		.pc_decode = nfs3svc_decode_mknodargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_mknodargs),
+		.pc_argzero = sizeof(struct nfsd3_mknodargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+		.pc_name = "MKNOD",
+	},
+	[NFS3PROC_REMOVE] = {
+		.pc_func = nfsd3_proc_remove,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_argzero = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+		.pc_name = "REMOVE",
+	},
+	[NFS3PROC_RMDIR] = {
+		.pc_func = nfsd3_proc_rmdir,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_argzero = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+		.pc_name = "RMDIR",
+	},
+	[NFS3PROC_RENAME] = {
+		.pc_func = nfsd3_proc_rename,
+		.pc_decode = nfs3svc_decode_renameargs,
+		.pc_encode = nfs3svc_encode_renameres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_renameargs),
+		.pc_argzero = sizeof(struct nfsd3_renameargs),
+		.pc_ressize = sizeof(struct nfsd3_renameres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC+WC,
+		.pc_name = "RENAME",
+	},
+	[NFS3PROC_LINK] = {
+		.pc_func = nfsd3_proc_link,
+		.pc_decode = nfs3svc_decode_linkargs,
+		.pc_encode = nfs3svc_encode_linkres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_linkargs),
+		.pc_argzero = sizeof(struct nfsd3_linkargs),
+		.pc_ressize = sizeof(struct nfsd3_linkres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+pAT+WC,
+		.pc_name = "LINK",
+	},
+	[NFS3PROC_READDIR] = {
+		.pc_func = nfsd3_proc_readdir,
+		.pc_decode = nfs3svc_decode_readdirargs,
+		.pc_encode = nfs3svc_encode_readdirres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readdirargs),
+		.pc_argzero = sizeof(struct nfsd3_readdirargs),
+		.pc_ressize = sizeof(struct nfsd3_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_name = "READDIR",
+	},
+	[NFS3PROC_READDIRPLUS] = {
+		.pc_func = nfsd3_proc_readdirplus,
+		.pc_decode = nfs3svc_decode_readdirplusargs,
+		.pc_encode = nfs3svc_encode_readdirres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readdirplusargs),
+		.pc_argzero = sizeof(struct nfsd3_readdirplusargs),
+		.pc_ressize = sizeof(struct nfsd3_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_name = "READDIRPLUS",
+	},
+	[NFS3PROC_FSSTAT] = {
+		.pc_func = nfsd3_proc_fsstat,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_fsstatres,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_fsstatres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+2*6+1,
+		.pc_name = "FSSTAT",
+	},
+	[NFS3PROC_FSINFO] = {
+		.pc_func = nfsd3_proc_fsinfo,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_fsinfores,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_fsinfores),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+12,
+		.pc_name = "FSINFO",
+	},
+	[NFS3PROC_PATHCONF] = {
+		.pc_func = nfsd3_proc_pathconf,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_pathconfres,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_argzero = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_pathconfres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+6,
+		.pc_name = "PATHCONF",
+	},
+	[NFS3PROC_COMMIT] = {
+		.pc_func = nfsd3_proc_commit,
+		.pc_decode = nfs3svc_decode_commitargs,
+		.pc_encode = nfs3svc_encode_commitres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_commitargs),
+		.pc_argzero = sizeof(struct nfsd3_commitargs),
+		.pc_ressize = sizeof(struct nfsd3_commitres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+WC+2,
+		.pc_name = "COMMIT",
+	},
+};
+
+const struct svc_version nfsd_version3 = {
+	.vs_vers	= 3,
+	.vs_nproc	= ARRAY_SIZE(nfsd_procedures3),
+	.vs_proc	= nfsd_procedures3,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
new file mode 100644
index 000000000..e481804bb
--- /dev/null
+++ b/fs/nfsd/nfs3xdr.c
@@ -0,0 +1,1356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XDR support for nfsd/protocol version 3.
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ *
+ * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
+ */
+
+#include <linux/namei.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include "xdr3.h"
+#include "auth.h"
+#include "netns.h"
+#include "vfs.h"
+
+/*
+ * Force construction of an empty post-op attr
+ */
+static const struct svc_fh nfs3svc_null_fh = {
+	.fh_no_wcc	= true,
+};
+
+/*
+ * time_delta. {1, 0} means the server is accurate only
+ * to the nearest second.
+ */
+static const struct timespec64 nfs3svc_time_delta = {
+	.tv_sec		= 1,
+	.tv_nsec	= 0,
+};
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static const u32 nfs3_ftypes[] = {
+	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
+	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
+	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
+	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
+};
+
+
+/*
+ * Basic NFSv3 data types (RFC 1813 Sections 2.5 and 2.6)
+ */
+
+static __be32 *
+encode_nfstime3(__be32 *p, const struct timespec64 *time)
+{
+	*p++ = cpu_to_be32((u32)time->tv_sec);
+	*p++ = cpu_to_be32(time->tv_nsec);
+
+	return p;
+}
+
+static bool
+svcxdr_decode_nfstime3(struct xdr_stream *xdr, struct timespec64 *timep)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT * 2);
+	if (!p)
+		return false;
+	timep->tv_sec = be32_to_cpup(p++);
+	timep->tv_nsec = be32_to_cpup(p);
+
+	return true;
+}
+
+/**
+ * svcxdr_decode_nfs_fh3 - Decode an NFSv3 file handle
+ * @xdr: XDR stream positioned at an undecoded NFSv3 FH
+ * @fhp: OUT: filled-in server file handle
+ *
+ * Return values:
+ *  %false: The encoded file handle was not valid
+ *  %true: @fhp has been initialized
+ */
+bool
+svcxdr_decode_nfs_fh3(struct xdr_stream *xdr, struct svc_fh *fhp)
+{
+	__be32 *p;
+	u32 size;
+
+	if (xdr_stream_decode_u32(xdr, &size) < 0)
+		return false;
+	if (size == 0 || size > NFS3_FHSIZE)
+		return false;
+	p = xdr_inline_decode(xdr, size);
+	if (!p)
+		return false;
+	fh_init(fhp, NFS3_FHSIZE);
+	fhp->fh_handle.fh_size = size;
+	memcpy(&fhp->fh_handle.fh_raw, p, size);
+
+	return true;
+}
+
+/**
+ * svcxdr_encode_nfsstat3 - Encode an NFSv3 status code
+ * @xdr: XDR stream
+ * @status: status value to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
+svcxdr_encode_nfsstat3(struct xdr_stream *xdr, __be32 status)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(status));
+	if (!p)
+		return false;
+	*p = status;
+
+	return true;
+}
+
+static bool
+svcxdr_encode_nfs_fh3(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+	u32 size = fhp->fh_handle.fh_size;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT + size);
+	if (!p)
+		return false;
+	*p++ = cpu_to_be32(size);
+	if (size)
+		p[XDR_QUADLEN(size) - 1] = 0;
+	memcpy(p, &fhp->fh_handle.fh_raw, size);
+
+	return true;
+}
+
+static bool
+svcxdr_encode_post_op_fh3(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	if (!svcxdr_encode_nfs_fh3(xdr, fhp))
+		return false;
+
+	return true;
+}
+
+static bool
+svcxdr_encode_cookieverf3(struct xdr_stream *xdr, const __be32 *verf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS3_COOKIEVERFSIZE);
+	if (!p)
+		return false;
+	memcpy(p, verf, NFS3_COOKIEVERFSIZE);
+
+	return true;
+}
+
+static bool
+svcxdr_encode_writeverf3(struct xdr_stream *xdr, const __be32 *verf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS3_WRITEVERFSIZE);
+	if (!p)
+		return false;
+	memcpy(p, verf, NFS3_WRITEVERFSIZE);
+
+	return true;
+}
+
+static bool
+svcxdr_decode_filename3(struct xdr_stream *xdr, char **name, unsigned int *len)
+{
+	u32 size, i;
+	__be32 *p;
+	char *c;
+
+	if (xdr_stream_decode_u32(xdr, &size) < 0)
+		return false;
+	if (size == 0 || size > NFS3_MAXNAMLEN)
+		return false;
+	p = xdr_inline_decode(xdr, size);
+	if (!p)
+		return false;
+
+	*len = size;
+	*name = (char *)p;
+	for (i = 0, c = *name; i < size; i++, c++) {
+		if (*c == '\0' || *c == '/')
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+svcxdr_decode_diropargs3(struct xdr_stream *xdr, struct svc_fh *fhp,
+			 char **name, unsigned int *len)
+{
+	return svcxdr_decode_nfs_fh3(xdr, fhp) &&
+		svcxdr_decode_filename3(xdr, name, len);
+}
+
+static bool
+svcxdr_decode_sattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		     struct iattr *iap)
+{
+	u32 set_it;
+
+	iap->ia_valid = 0;
+
+	if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+		return false;
+	if (set_it) {
+		u32 mode;
+
+		if (xdr_stream_decode_u32(xdr, &mode) < 0)
+			return false;
+		iap->ia_valid |= ATTR_MODE;
+		iap->ia_mode = mode;
+	}
+	if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+		return false;
+	if (set_it) {
+		u32 uid;
+
+		if (xdr_stream_decode_u32(xdr, &uid) < 0)
+			return false;
+		iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), uid);
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
+	}
+	if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+		return false;
+	if (set_it) {
+		u32 gid;
+
+		if (xdr_stream_decode_u32(xdr, &gid) < 0)
+			return false;
+		iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), gid);
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
+	}
+	if (xdr_stream_decode_bool(xdr, &set_it) < 0)
+		return false;
+	if (set_it) {
+		u64 newsize;
+
+		if (xdr_stream_decode_u64(xdr, &newsize) < 0)
+			return false;
+		iap->ia_valid |= ATTR_SIZE;
+		iap->ia_size = newsize;
+	}
+	if (xdr_stream_decode_u32(xdr, &set_it) < 0)
+		return false;
+	switch (set_it) {
+	case DONT_CHANGE:
+		break;
+	case SET_TO_SERVER_TIME:
+		iap->ia_valid |= ATTR_ATIME;
+		break;
+	case SET_TO_CLIENT_TIME:
+		if (!svcxdr_decode_nfstime3(xdr, &iap->ia_atime))
+			return false;
+		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+		break;
+	default:
+		return false;
+	}
+	if (xdr_stream_decode_u32(xdr, &set_it) < 0)
+		return false;
+	switch (set_it) {
+	case DONT_CHANGE:
+		break;
+	case SET_TO_SERVER_TIME:
+		iap->ia_valid |= ATTR_MTIME;
+		break;
+	case SET_TO_CLIENT_TIME:
+		if (!svcxdr_decode_nfstime3(xdr, &iap->ia_mtime))
+			return false;
+		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+svcxdr_decode_sattrguard3(struct xdr_stream *xdr, struct nfsd3_sattrargs *args)
+{
+	u32 check;
+
+	if (xdr_stream_decode_bool(xdr, &check) < 0)
+		return false;
+	if (check) {
+		if (!svcxdr_decode_nfstime3(xdr, &args->guardtime))
+			return false;
+		args->check_guard = 1;
+	} else
+		args->check_guard = 0;
+
+	return true;
+}
+
+static bool
+svcxdr_decode_specdata3(struct xdr_stream *xdr, struct nfsd3_mknodargs *args)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT * 2);
+	if (!p)
+		return false;
+	args->major = be32_to_cpup(p++);
+	args->minor = be32_to_cpup(p);
+
+	return true;
+}
+
+static bool
+svcxdr_decode_devicedata3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			  struct nfsd3_mknodargs *args)
+{
+	return svcxdr_decode_sattr3(rqstp, xdr, &args->attrs) &&
+		svcxdr_decode_specdata3(xdr, args);
+}
+
+static bool
+svcxdr_encode_fattr3(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		     const struct svc_fh *fhp, const struct kstat *stat)
+{
+	struct user_namespace *userns = nfsd_user_namespace(rqstp);
+	__be32 *p;
+	u64 fsid;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 21);
+	if (!p)
+		return false;
+
+	*p++ = cpu_to_be32(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
+	*p++ = cpu_to_be32((u32)(stat->mode & S_IALLUGO));
+	*p++ = cpu_to_be32((u32)stat->nlink);
+	*p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
+	*p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));
+	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN)
+		p = xdr_encode_hyper(p, (u64)NFS3_MAXPATHLEN);
+	else
+		p = xdr_encode_hyper(p, (u64)stat->size);
+
+	/* used */
+	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
+
+	/* rdev */
+	*p++ = cpu_to_be32((u32)MAJOR(stat->rdev));
+	*p++ = cpu_to_be32((u32)MINOR(stat->rdev));
+
+	switch(fsid_source(fhp)) {
+	case FSIDSOURCE_FSID:
+		fsid = (u64)fhp->fh_export->ex_fsid;
+		break;
+	case FSIDSOURCE_UUID:
+		fsid = ((u64 *)fhp->fh_export->ex_uuid)[0];
+		fsid ^= ((u64 *)fhp->fh_export->ex_uuid)[1];
+		break;
+	default:
+		fsid = (u64)huge_encode_dev(fhp->fh_dentry->d_sb->s_dev);
+	}
+	p = xdr_encode_hyper(p, fsid);
+
+	/* fileid */
+	p = xdr_encode_hyper(p, stat->ino);
+
+	p = encode_nfstime3(p, &stat->atime);
+	p = encode_nfstime3(p, &stat->mtime);
+	encode_nfstime3(p, &stat->ctime);
+
+	return true;
+}
+
+static bool
+svcxdr_encode_wcc_attr(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 6);
+	if (!p)
+		return false;
+	p = xdr_encode_hyper(p, (u64)fhp->fh_pre_size);
+	p = encode_nfstime3(p, &fhp->fh_pre_mtime);
+	encode_nfstime3(p, &fhp->fh_pre_ctime);
+
+	return true;
+}
+
+static bool
+svcxdr_encode_pre_op_attr(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+	if (!fhp->fh_pre_saved) {
+		if (xdr_stream_encode_item_absent(xdr) < 0)
+			return false;
+		return true;
+	}
+
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	return svcxdr_encode_wcc_attr(xdr, fhp);
+}
+
+/**
+ * svcxdr_encode_post_op_attr - Encode NFSv3 post-op attributes
+ * @rqstp: Context of a completed RPC transaction
+ * @xdr: XDR stream
+ * @fhp: File handle to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
+svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			   const struct svc_fh *fhp)
+{
+	struct dentry *dentry = fhp->fh_dentry;
+	struct kstat stat;
+
+	/*
+	 * The inode may be NULL if the call failed because of a
+	 * stale file handle. In this case, no attributes are
+	 * returned.
+	 */
+	if (fhp->fh_no_wcc || !dentry || !d_really_is_positive(dentry))
+		goto no_post_op_attrs;
+	if (fh_getattr(fhp, &stat) != nfs_ok)
+		goto no_post_op_attrs;
+
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	lease_get_mtime(d_inode(dentry), &stat.mtime);
+	if (!svcxdr_encode_fattr3(rqstp, xdr, fhp, &stat))
+		return false;
+
+	return true;
+
+no_post_op_attrs:
+	return xdr_stream_encode_item_absent(xdr) > 0;
+}
+
+/*
+ * Encode weak cache consistency data
+ */
+static bool
+svcxdr_encode_wcc_data(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		       const struct svc_fh *fhp)
+{
+	struct dentry *dentry = fhp->fh_dentry;
+
+	if (!dentry || !d_really_is_positive(dentry) || !fhp->fh_post_saved)
+		goto neither;
+
+	/* before */
+	if (!svcxdr_encode_pre_op_attr(xdr, fhp))
+		return false;
+
+	/* after */
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	if (!svcxdr_encode_fattr3(rqstp, xdr, fhp, &fhp->fh_post_attr))
+		return false;
+
+	return true;
+
+neither:
+	if (xdr_stream_encode_item_absent(xdr) < 0)
+		return false;
+	if (!svcxdr_encode_post_op_attr(rqstp, xdr, fhp))
+		return false;
+
+	return true;
+}
+
+/*
+ * XDR decode functions
+ */
+
+bool
+nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_fhandle *args = rqstp->rq_argp;
+
+	return svcxdr_decode_nfs_fh3(xdr, &args->fh);
+}
+
+bool
+nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_sattrargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_nfs_fh3(xdr, &args->fh) &&
+		svcxdr_decode_sattr3(rqstp, xdr, &args->attrs) &&
+		svcxdr_decode_sattrguard3(xdr, args);
+}
+
+bool
+nfs3svc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_diropargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs3(xdr, &args->fh, &args->name, &args->len);
+}
+
+bool
+nfs3svc_decode_accessargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_accessargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->access) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nfs3svc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u64(xdr, &args->offset) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nfs3svc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_writeargs *args = rqstp->rq_argp;
+	u32 max_blocksize = svc_max_payload(rqstp);
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u64(xdr, &args->offset) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->stable) < 0)
+		return false;
+
+	/* opaque data */
+	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
+		return false;
+
+	/* request sanity */
+	if (args->count != args->len)
+		return false;
+	if (args->count > max_blocksize) {
+		args->count = max_blocksize;
+		args->len = max_blocksize;
+	}
+
+	return xdr_stream_subsegment(xdr, &args->payload, args->count);
+}
+
+bool
+nfs3svc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_createargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_diropargs3(xdr, &args->fh, &args->name, &args->len))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->createmode) < 0)
+		return false;
+	switch (args->createmode) {
+	case NFS3_CREATE_UNCHECKED:
+	case NFS3_CREATE_GUARDED:
+		return svcxdr_decode_sattr3(rqstp, xdr, &args->attrs);
+	case NFS3_CREATE_EXCLUSIVE:
+		args->verf = xdr_inline_decode(xdr, NFS3_CREATEVERFSIZE);
+		if (!args->verf)
+			return false;
+		break;
+	default:
+		return false;
+	}
+	return true;
+}
+
+bool
+nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_createargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs3(xdr, &args->fh,
+					&args->name, &args->len) &&
+		svcxdr_decode_sattr3(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_symlinkargs *args = rqstp->rq_argp;
+	struct kvec *head = rqstp->rq_arg.head;
+
+	if (!svcxdr_decode_diropargs3(xdr, &args->ffh, &args->fname, &args->flen))
+		return false;
+	if (!svcxdr_decode_sattr3(rqstp, xdr, &args->attrs))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
+		return false;
+
+	/* symlink_data */
+	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
+	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
+	return args->first.iov_base != NULL;
+}
+
+bool
+nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_mknodargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_diropargs3(xdr, &args->fh, &args->name, &args->len))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->ftype) < 0)
+		return false;
+	switch (args->ftype) {
+	case NF3CHR:
+	case NF3BLK:
+		return svcxdr_decode_devicedata3(rqstp, xdr, args);
+	case NF3SOCK:
+	case NF3FIFO:
+		return svcxdr_decode_sattr3(rqstp, xdr, &args->attrs);
+	case NF3REG:
+	case NF3DIR:
+	case NF3LNK:
+		/* Valid XDR but illegal file types */
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+bool
+nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_renameargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs3(xdr, &args->ffh,
+					&args->fname, &args->flen) &&
+		svcxdr_decode_diropargs3(xdr, &args->tfh,
+					 &args->tname, &args->tlen);
+}
+
+bool
+nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_linkargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_nfs_fh3(xdr, &args->ffh) &&
+		svcxdr_decode_diropargs3(xdr, &args->tfh,
+					 &args->tname, &args->tlen);
+}
+
+bool
+nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readdirargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u64(xdr, &args->cookie) < 0)
+		return false;
+	args->verf = xdr_inline_decode(xdr, NFS3_COOKIEVERFSIZE);
+	if (!args->verf)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readdirargs *args = rqstp->rq_argp;
+	u32 dircount;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u64(xdr, &args->cookie) < 0)
+		return false;
+	args->verf = xdr_inline_decode(xdr, NFS3_COOKIEVERFSIZE);
+	if (!args->verf)
+		return false;
+	/* dircount is ignored */
+	if (xdr_stream_decode_u32(xdr, &dircount) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_commitargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u64(xdr, &args->offset) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+
+	return true;
+}
+
+/*
+ * XDR encode functions
+ */
+
+/* GETATTR */
+bool
+nfs3svc_encode_getattrres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		lease_get_mtime(d_inode(resp->fh.fh_dentry), &resp->stat.mtime);
+		if (!svcxdr_encode_fattr3(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+/* SETATTR, REMOVE, RMDIR */
+bool
+nfs3svc_encode_wccstat(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
+		svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh);
+}
+
+/* LOOKUP */
+bool
+nfs3svc_encode_lookupres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_nfs_fh3(xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->dirfh))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->dirfh))
+			return false;
+	}
+
+	return true;
+}
+
+/* ACCESS */
+bool
+nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->access) < 0)
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* READLINK */
+bool
+nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
+	struct kvec *head = rqstp->rq_res.head;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
+			return false;
+		svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages, 0,
+					   resp->len);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* READ */
+bool
+nfs3svc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readres *resp = rqstp->rq_resp;
+	struct kvec *head = rqstp->rq_res.head;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return false;
+		if (xdr_stream_encode_bool(xdr, resp->eof) < 0)
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return false;
+		svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages,
+					   rqstp->rq_res.page_base,
+					   resp->count);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* WRITE */
+bool
+nfs3svc_encode_writeres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_writeres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->committed) < 0)
+			return false;
+		if (!svcxdr_encode_writeverf3(xdr, resp->verf))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* CREATE, MKDIR, SYMLINK, MKNOD */
+bool
+nfs3svc_encode_createres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_fh3(xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->dirfh))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->dirfh))
+			return false;
+	}
+
+	return true;
+}
+
+/* RENAME */
+bool
+nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_renameres *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
+		svcxdr_encode_wcc_data(rqstp, xdr, &resp->ffh) &&
+		svcxdr_encode_wcc_data(rqstp, xdr, &resp->tfh);
+}
+
+/* LINK */
+bool
+nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_linkres *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
+		svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh) &&
+		svcxdr_encode_wcc_data(rqstp, xdr, &resp->tfh);
+}
+
+/* READDIR */
+bool
+nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_readdirres *resp = rqstp->rq_resp;
+	struct xdr_buf *dirlist = &resp->dirlist;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_cookieverf3(xdr, resp->verf))
+			return false;
+		svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0,
+					   dirlist->len);
+		/* no more entries */
+		if (xdr_stream_encode_item_absent(xdr) < 0)
+			return false;
+		if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+static __be32
+compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
+		 const char *name, int namlen, u64 ino)
+{
+	struct svc_export	*exp;
+	struct dentry		*dparent, *dchild;
+	__be32 rv = nfserr_noent;
+
+	dparent = cd->fh.fh_dentry;
+	exp  = cd->fh.fh_export;
+
+	if (name_is_dot_dotdot(name, namlen)) {
+		if (namlen == 2) {
+			dchild = dget_parent(dparent);
+			/*
+			 * Don't return filehandle for ".." if we're at
+			 * the filesystem or export root:
+			 */
+			if (dchild == dparent)
+				goto out;
+			if (dparent == exp->ex_path.dentry)
+				goto out;
+		} else
+			dchild = dget(dparent);
+	} else
+		dchild = lookup_one_positive_unlocked(&nop_mnt_idmap,
+						      &QSTR_LEN(name, namlen),
+						      dparent);
+	if (IS_ERR(dchild))
+		return rv;
+	if (d_mountpoint(dchild))
+		goto out;
+	if (dchild->d_inode->i_ino != ino)
+		goto out;
+	rv = fh_compose(fhp, exp, dchild, &cd->fh);
+out:
+	dput(dchild);
+	return rv;
+}
+
+/**
+ * nfs3svc_encode_cookie3 - Encode a directory offset cookie
+ * @resp: readdir result context
+ * @offset: offset cookie to encode
+ *
+ * The buffer space for the offset cookie has already been reserved
+ * by svcxdr_encode_entry3_common().
+ */
+void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset)
+{
+	__be64 cookie = cpu_to_be64(offset);
+
+	if (!resp->cookie_offset)
+		return;
+	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
+			       sizeof(cookie));
+	resp->cookie_offset = 0;
+}
+
+static bool
+svcxdr_encode_entry3_common(struct nfsd3_readdirres *resp, const char *name,
+			    int namlen, loff_t offset, u64 ino)
+{
+	struct xdr_buf *dirlist = &resp->dirlist;
+	struct xdr_stream *xdr = &resp->xdr;
+
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	/* fileid */
+	if (xdr_stream_encode_u64(xdr, ino) < 0)
+		return false;
+	/* name */
+	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS3_MAXNAMLEN)) < 0)
+		return false;
+	/* cookie */
+	resp->cookie_offset = dirlist->len;
+	if (xdr_stream_encode_u64(xdr, OFFSET_MAX) < 0)
+		return false;
+
+	return true;
+}
+
+/**
+ * nfs3svc_encode_entry3 - encode one NFSv3 READDIR entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ *   %0: Entry was successfully encoded.
+ *   %-EINVAL: An encoding problem occurred, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ *   - resp->xdr
+ *   - resp->common.err
+ *   - resp->cookie_offset
+ */
+int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
+			  loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = data;
+	struct nfsd3_readdirres *resp = container_of(ccd,
+						     struct nfsd3_readdirres,
+						     common);
+	unsigned int starting_length = resp->dirlist.len;
+
+	/* The offset cookie for the previous entry */
+	nfs3svc_encode_cookie3(resp, offset);
+
+	if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
+		goto out_toosmall;
+
+	xdr_commit_encode(&resp->xdr);
+	resp->common.err = nfs_ok;
+	return 0;
+
+out_toosmall:
+	resp->cookie_offset = 0;
+	resp->common.err = nfserr_toosmall;
+	resp->dirlist.len = starting_length;
+	return -EINVAL;
+}
+
+static bool
+svcxdr_encode_entry3_plus(struct nfsd3_readdirres *resp, const char *name,
+			  int namlen, u64 ino)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct svc_fh *fhp = &resp->scratch;
+	bool result;
+
+	result = false;
+	fh_init(fhp, NFS3_FHSIZE);
+	if (compose_entry_fh(resp, fhp, name, namlen, ino) != nfs_ok)
+		goto out_noattrs;
+
+	if (!svcxdr_encode_post_op_attr(resp->rqstp, xdr, fhp))
+		goto out;
+	if (!svcxdr_encode_post_op_fh3(xdr, fhp))
+		goto out;
+	result = true;
+
+out:
+	fh_put(fhp);
+	return result;
+
+out_noattrs:
+	if (xdr_stream_encode_item_absent(xdr) < 0)
+		return false;
+	if (xdr_stream_encode_item_absent(xdr) < 0)
+		return false;
+	return true;
+}
+
+/**
+ * nfs3svc_encode_entryplus3 - encode one NFSv3 READDIRPLUS entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ *   %0: Entry was successfully encoded.
+ *   %-EINVAL: An encoding problem occurred, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ *   - resp->xdr
+ *   - resp->common.err
+ *   - resp->cookie_offset
+ */
+int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
+			      loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = data;
+	struct nfsd3_readdirres *resp = container_of(ccd,
+						     struct nfsd3_readdirres,
+						     common);
+	unsigned int starting_length = resp->dirlist.len;
+
+	/* The offset cookie for the previous entry */
+	nfs3svc_encode_cookie3(resp, offset);
+
+	if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
+		goto out_toosmall;
+	if (!svcxdr_encode_entry3_plus(resp, name, namlen, ino))
+		goto out_toosmall;
+
+	xdr_commit_encode(&resp->xdr);
+	resp->common.err = nfs_ok;
+	return 0;
+
+out_toosmall:
+	resp->cookie_offset = 0;
+	resp->common.err = nfserr_toosmall;
+	resp->dirlist.len = starting_length;
+	return -EINVAL;
+}
+
+static bool
+svcxdr_encode_fsstat3resok(struct xdr_stream *xdr,
+			   const struct nfsd3_fsstatres *resp)
+{
+	const struct kstatfs *s = &resp->stats;
+	u64 bs = s->f_bsize;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 13);
+	if (!p)
+		return false;
+	p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
+	p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
+	p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
+	p = xdr_encode_hyper(p, s->f_files);		/* total inodes */
+	p = xdr_encode_hyper(p, s->f_ffree);		/* free inodes */
+	p = xdr_encode_hyper(p, s->f_ffree);		/* user available inodes */
+	*p = cpu_to_be32(resp->invarsec);		/* mean unchanged time */
+
+	return true;
+}
+
+/* FSSTAT */
+bool
+nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+		if (!svcxdr_encode_fsstat3resok(xdr, resp))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+svcxdr_encode_fsinfo3resok(struct xdr_stream *xdr,
+			   const struct nfsd3_fsinfores *resp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 12);
+	if (!p)
+		return false;
+	*p++ = cpu_to_be32(resp->f_rtmax);
+	*p++ = cpu_to_be32(resp->f_rtpref);
+	*p++ = cpu_to_be32(resp->f_rtmult);
+	*p++ = cpu_to_be32(resp->f_wtmax);
+	*p++ = cpu_to_be32(resp->f_wtpref);
+	*p++ = cpu_to_be32(resp->f_wtmult);
+	*p++ = cpu_to_be32(resp->f_dtpref);
+	p = xdr_encode_hyper(p, resp->f_maxfilesize);
+	p = encode_nfstime3(p, &nfs3svc_time_delta);
+	*p = cpu_to_be32(resp->f_properties);
+
+	return true;
+}
+
+/* FSINFO */
+bool
+nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+		if (!svcxdr_encode_fsinfo3resok(xdr, resp))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+svcxdr_encode_pathconf3resok(struct xdr_stream *xdr,
+			     const struct nfsd3_pathconfres *resp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 6);
+	if (!p)
+		return false;
+	*p++ = cpu_to_be32(resp->p_link_max);
+	*p++ = cpu_to_be32(resp->p_name_max);
+	p = xdr_encode_bool(p, resp->p_no_trunc);
+	p = xdr_encode_bool(p, resp->p_chown_restricted);
+	p = xdr_encode_bool(p, resp->p_case_insensitive);
+	xdr_encode_bool(p, resp->p_case_preserving);
+
+	return true;
+}
+
+/* PATHCONF */
+bool
+nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+		if (!svcxdr_encode_pathconf3resok(xdr, resp))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return false;
+	}
+
+	return true;
+}
+
+/* COMMIT */
+bool
+nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd3_commitres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_writeverf3(xdr, resp->verf))
+			return false;
+		break;
+	default:
+		if (!svcxdr_encode_wcc_data(rqstp, xdr, &resp->fh))
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * XDR release functions
+ */
+void
+nfs3svc_release_fhandle(struct svc_rqst *rqstp)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void
+nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
+{
+	struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh1);
+	fh_put(&resp->fh2);
+}
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
new file mode 100644
index 000000000..2c2f2fd89
--- /dev/null
+++ b/fs/nfsd/nfs4acl.c
@@ -0,0 +1,884 @@
+/*
+ *  Common NFSv4 ACL handling code.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *  Jeff Sedlak <jsedlak@umich.edu>
+ *  J. Bruce Fields <bfields@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/posix_acl.h>
+
+#include "nfsfh.h"
+#include "nfsd.h"
+#include "acl.h"
+#include "vfs.h"
+
+#define NFS4_ACL_TYPE_DEFAULT	0x01
+#define NFS4_ACL_DIR		0x02
+#define NFS4_ACL_OWNER		0x04
+
+/* mode bit translations: */
+#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
+#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
+#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
+#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
+#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
+
+/* flags used to simulate posix default ACLs */
+#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
+		| NFS4_ACE_DIRECTORY_INHERIT_ACE)
+
+#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
+		| NFS4_ACE_INHERIT_ONLY_ACE \
+		| NFS4_ACE_IDENTIFIER_GROUP)
+
+static u32
+mask_from_posix(unsigned short perm, unsigned int flags)
+{
+	int mask = NFS4_ANYONE_MODE;
+
+	if (flags & NFS4_ACL_OWNER)
+		mask |= NFS4_OWNER_MODE;
+	if (perm & ACL_READ)
+		mask |= NFS4_READ_MODE;
+	if (perm & ACL_WRITE)
+		mask |= NFS4_WRITE_MODE;
+	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
+		mask |= NFS4_ACE_DELETE_CHILD;
+	if (perm & ACL_EXECUTE)
+		mask |= NFS4_EXECUTE_MODE;
+	return mask;
+}
+
+static u32
+deny_mask_from_posix(unsigned short perm, u32 flags)
+{
+	u32 mask = 0;
+
+	if (perm & ACL_READ)
+		mask |= NFS4_READ_MODE;
+	if (perm & ACL_WRITE)
+		mask |= NFS4_WRITE_MODE;
+	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
+		mask |= NFS4_ACE_DELETE_CHILD;
+	if (perm & ACL_EXECUTE)
+		mask |= NFS4_EXECUTE_MODE;
+	return mask;
+}
+
+/* XXX: modify functions to return NFS errors; they're only ever
+ * used by nfs code, after all.... */
+
+/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
+ * side of being more restrictive, so the mode bit mapping below is
+ * pessimistic.  An optimistic version would be needed to handle DENY's,
+ * but we expect to coalesce all ALLOWs and DENYs before mapping to mode
+ * bits. */
+
+static void
+low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
+{
+	u32 write_mode = NFS4_WRITE_MODE;
+
+	if (flags & NFS4_ACL_DIR)
+		write_mode |= NFS4_ACE_DELETE_CHILD;
+	*mode = 0;
+	if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
+		*mode |= ACL_READ;
+	if ((perm & write_mode) == write_mode)
+		*mode |= ACL_WRITE;
+	if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
+		*mode |= ACL_EXECUTE;
+}
+
+static short ace2type(struct nfs4_ace *);
+static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
+				unsigned int);
+
+int
+nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
+		struct nfs4_acl **acl)
+{
+	struct inode *inode = d_inode(dentry);
+	int error = 0;
+	struct posix_acl *pacl = NULL, *dpacl = NULL;
+	unsigned int flags = 0;
+	int size = 0;
+
+	pacl = get_inode_acl(inode, ACL_TYPE_ACCESS);
+	if (!pacl)
+		pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+
+	if (IS_ERR(pacl))
+		return PTR_ERR(pacl);
+
+	/* allocate for worst case: one (deny, allow) pair each: */
+	size += 2 * pacl->a_count;
+
+	if (S_ISDIR(inode->i_mode)) {
+		flags = NFS4_ACL_DIR;
+		dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(dpacl)) {
+			error = PTR_ERR(dpacl);
+			goto rel_pacl;
+		}
+
+		if (dpacl)
+			size += 2 * dpacl->a_count;
+	}
+
+	*acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
+	if (*acl == NULL) {
+		error = -ENOMEM;
+		goto out;
+	}
+	(*acl)->naces = 0;
+
+	_posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
+
+	if (dpacl)
+		_posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
+
+out:
+	posix_acl_release(dpacl);
+rel_pacl:
+	posix_acl_release(pacl);
+	return error;
+}
+
+struct posix_acl_summary {
+	unsigned short owner;
+	unsigned short users;
+	unsigned short group;
+	unsigned short groups;
+	unsigned short other;
+	unsigned short mask;
+};
+
+static void
+summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
+{
+	struct posix_acl_entry *pa, *pe;
+
+	/*
+	 * Only pas.users and pas.groups need initialization; previous
+	 * posix_acl_valid() calls ensure that the other fields will be
+	 * initialized in the following loop.  But, just to placate gcc:
+	 */
+	memset(pas, 0, sizeof(*pas));
+	pas->mask = 07;
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch (pa->e_tag) {
+			case ACL_USER_OBJ:
+				pas->owner = pa->e_perm;
+				break;
+			case ACL_GROUP_OBJ:
+				pas->group = pa->e_perm;
+				break;
+			case ACL_USER:
+				pas->users |= pa->e_perm;
+				break;
+			case ACL_GROUP:
+				pas->groups |= pa->e_perm;
+				break;
+			case ACL_OTHER:
+				pas->other = pa->e_perm;
+				break;
+			case ACL_MASK:
+				pas->mask = pa->e_perm;
+				break;
+		}
+	}
+	/* We'll only care about effective permissions: */
+	pas->users &= pas->mask;
+	pas->group &= pas->mask;
+	pas->groups &= pas->mask;
+}
+
+/* We assume the acl has been verified with posix_acl_valid. */
+static void
+_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
+						unsigned int flags)
+{
+	struct posix_acl_entry *pa, *group_owner_entry;
+	struct nfs4_ace *ace;
+	struct posix_acl_summary pas;
+	unsigned short deny;
+	int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
+		NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
+
+	BUG_ON(pacl->a_count < 3);
+	summarize_posix_acl(pacl, &pas);
+
+	pa = pacl->a_entries;
+	ace = acl->aces + acl->naces;
+
+	/* We could deny everything not granted by the owner: */
+	deny = ~pas.owner;
+	/*
+	 * but it is equivalent (and simpler) to deny only what is not
+	 * granted by later entries:
+	 */
+	deny &= pas.users | pas.group | pas.groups | pas.other;
+	if (deny) {
+		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = deny_mask_from_posix(deny, flags);
+		ace->whotype = NFS4_ACL_WHO_OWNER;
+		ace++;
+		acl->naces++;
+	}
+
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
+	ace->whotype = NFS4_ACL_WHO_OWNER;
+	ace++;
+	acl->naces++;
+	pa++;
+
+	while (pa->e_tag == ACL_USER) {
+		deny = ~(pa->e_perm & pas.mask);
+		deny &= pas.groups | pas.group | pas.other;
+		if (deny) {
+			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+			ace->flag = eflag;
+			ace->access_mask = deny_mask_from_posix(deny, flags);
+			ace->whotype = NFS4_ACL_WHO_NAMED;
+			ace->who_uid = pa->e_uid;
+			ace++;
+			acl->naces++;
+		}
+		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
+						   flags);
+		ace->whotype = NFS4_ACL_WHO_NAMED;
+		ace->who_uid = pa->e_uid;
+		ace++;
+		acl->naces++;
+		pa++;
+	}
+
+	/* In the case of groups, we apply allow ACEs first, then deny ACEs,
+	 * since a user can be in more than one group.  */
+
+	/* allow ACEs */
+
+	group_owner_entry = pa;
+
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pas.group, flags);
+	ace->whotype = NFS4_ACL_WHO_GROUP;
+	ace++;
+	acl->naces++;
+	pa++;
+
+	while (pa->e_tag == ACL_GROUP) {
+		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+		ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
+		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
+						   flags);
+		ace->whotype = NFS4_ACL_WHO_NAMED;
+		ace->who_gid = pa->e_gid;
+		ace++;
+		acl->naces++;
+		pa++;
+	}
+
+	/* deny ACEs */
+
+	pa = group_owner_entry;
+
+	deny = ~pas.group & pas.other;
+	if (deny) {
+		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = deny_mask_from_posix(deny, flags);
+		ace->whotype = NFS4_ACL_WHO_GROUP;
+		ace++;
+		acl->naces++;
+	}
+	pa++;
+
+	while (pa->e_tag == ACL_GROUP) {
+		deny = ~(pa->e_perm & pas.mask);
+		deny &= pas.other;
+		if (deny) {
+			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+			ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
+			ace->access_mask = deny_mask_from_posix(deny, flags);
+			ace->whotype = NFS4_ACL_WHO_NAMED;
+			ace->who_gid = pa->e_gid;
+			ace++;
+			acl->naces++;
+		}
+		pa++;
+	}
+
+	if (pa->e_tag == ACL_MASK)
+		pa++;
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pa->e_perm, flags);
+	ace->whotype = NFS4_ACL_WHO_EVERYONE;
+	acl->naces++;
+}
+
+static bool
+pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
+{
+	if (pace1->e_tag != pace2->e_tag)
+		return pace1->e_tag > pace2->e_tag;
+	if (pace1->e_tag == ACL_USER)
+		return uid_gt(pace1->e_uid, pace2->e_uid);
+	if (pace1->e_tag == ACL_GROUP)
+		return gid_gt(pace1->e_gid, pace2->e_gid);
+	return false;
+}
+
+/**
+ * sort_pacl_range - sort a range of POSIX ACL entries by tag and id
+ * @pacl: POSIX ACL containing entries to sort
+ * @start: starting index of range to sort
+ * @end: ending index of range to sort (inclusive)
+ *
+ * Sorts ACL entries in place so that USER entries are ordered by UID
+ * and GROUP entries are ordered by GID. Required before calling
+ * posix_acl_valid().
+ */
+void sort_pacl_range(struct posix_acl *pacl, int start, int end)
+{
+	int sorted = 0, i;
+
+	/* Bubble sort: acceptable here because ACLs are typically short. */
+	while (!sorted) {
+		sorted = 1;
+		for (i = start; i < end; i++) {
+			if (pace_gt(&pacl->a_entries[i],
+				    &pacl->a_entries[i+1])) {
+				sorted = 0;
+				swap(pacl->a_entries[i],
+				     pacl->a_entries[i + 1]);
+			}
+		}
+	}
+}
+
+static void
+sort_pacl(struct posix_acl *pacl)
+{
+	/* posix_acl_valid requires that users and groups be in order
+	 * by uid/gid. */
+	int i, j;
+
+	/* no users or groups */
+	if (!pacl || pacl->a_count <= 4)
+		return;
+
+	i = 1;
+	while (pacl->a_entries[i].e_tag == ACL_USER)
+		i++;
+	sort_pacl_range(pacl, 1, i-1);
+
+	BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
+	j = ++i;
+	while (pacl->a_entries[j].e_tag == ACL_GROUP)
+		j++;
+	sort_pacl_range(pacl, i, j-1);
+	return;
+}
+
+/*
+ * While processing the NFSv4 ACE, this maintains bitmasks representing
+ * which permission bits have been allowed and which denied to a given
+ * entity: */
+struct posix_ace_state {
+	u32 allow;
+	u32 deny;
+};
+
+struct posix_user_ace_state {
+	union {
+		kuid_t uid;
+		kgid_t gid;
+	};
+	struct posix_ace_state perms;
+};
+
+struct posix_ace_state_array {
+	int n;
+	struct posix_user_ace_state aces[];
+};
+
+/*
+ * While processing the NFSv4 ACE, this maintains the partial permissions
+ * calculated so far: */
+
+struct posix_acl_state {
+	unsigned char valid;
+	struct posix_ace_state owner;
+	struct posix_ace_state group;
+	struct posix_ace_state other;
+	struct posix_ace_state everyone;
+	struct posix_ace_state mask; /* Deny unused in this case */
+	struct posix_ace_state_array *users;
+	struct posix_ace_state_array *groups;
+};
+
+static int
+init_state(struct posix_acl_state *state, int cnt)
+{
+	int alloc;
+
+	memset(state, 0, sizeof(struct posix_acl_state));
+	/*
+	 * In the worst case, each individual acl could be for a distinct
+	 * named user or group, but we don't know which, so we allocate
+	 * enough space for either:
+	 */
+	alloc = sizeof(struct posix_ace_state_array)
+		+ cnt*sizeof(struct posix_user_ace_state);
+	state->users = kzalloc(alloc, GFP_KERNEL);
+	if (!state->users)
+		return -ENOMEM;
+	state->groups = kzalloc(alloc, GFP_KERNEL);
+	if (!state->groups) {
+		kfree(state->users);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static void
+free_state(struct posix_acl_state *state) {
+	kfree(state->users);
+	kfree(state->groups);
+}
+
+static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
+{
+	state->mask.allow |= astate->allow;
+}
+
+static struct posix_acl *
+posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
+{
+	struct posix_acl_entry *pace;
+	struct posix_acl *pacl;
+	int nace;
+	int i;
+
+	/*
+	 * ACLs with no ACEs are treated differently in the inheritable
+	 * and effective cases: when there are no inheritable ACEs,
+	 * calls ->set_acl with a NULL ACL structure.
+	 */
+	if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT))
+		return NULL;
+
+	/*
+	 * When there are no effective ACEs, the following will end
+	 * up setting a 3-element effective posix ACL with all
+	 * permissions zero.
+	 */
+	if (!state->users->n && !state->groups->n)
+		nace = 3;
+	else /* Note we also include a MASK ACE in this case: */
+		nace = 4 + state->users->n + state->groups->n;
+	pacl = posix_acl_alloc(nace, GFP_KERNEL);
+	if (!pacl)
+		return ERR_PTR(-ENOMEM);
+
+	pace = pacl->a_entries;
+	pace->e_tag = ACL_USER_OBJ;
+	low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
+
+	for (i=0; i < state->users->n; i++) {
+		pace++;
+		pace->e_tag = ACL_USER;
+		low_mode_from_nfs4(state->users->aces[i].perms.allow,
+					&pace->e_perm, flags);
+		pace->e_uid = state->users->aces[i].uid;
+		add_to_mask(state, &state->users->aces[i].perms);
+	}
+
+	pace++;
+	pace->e_tag = ACL_GROUP_OBJ;
+	low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
+	add_to_mask(state, &state->group);
+
+	for (i=0; i < state->groups->n; i++) {
+		pace++;
+		pace->e_tag = ACL_GROUP;
+		low_mode_from_nfs4(state->groups->aces[i].perms.allow,
+					&pace->e_perm, flags);
+		pace->e_gid = state->groups->aces[i].gid;
+		add_to_mask(state, &state->groups->aces[i].perms);
+	}
+
+	if (state->users->n || state->groups->n) {
+		pace++;
+		pace->e_tag = ACL_MASK;
+		low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
+	}
+
+	pace++;
+	pace->e_tag = ACL_OTHER;
+	low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
+
+	return pacl;
+}
+
+static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
+{
+	/* Allow all bits in the mask not already denied: */
+	astate->allow |= mask & ~astate->deny;
+}
+
+static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
+{
+	/* Deny all bits in the mask not already allowed: */
+	astate->deny |= mask & ~astate->allow;
+}
+
+static int find_uid(struct posix_acl_state *state, kuid_t uid)
+{
+	struct posix_ace_state_array *a = state->users;
+	int i;
+
+	for (i = 0; i < a->n; i++)
+		if (uid_eq(a->aces[i].uid, uid))
+			return i;
+	/* Not found: */
+	a->n++;
+	a->aces[i].uid = uid;
+	a->aces[i].perms.allow = state->everyone.allow;
+	a->aces[i].perms.deny  = state->everyone.deny;
+
+	return i;
+}
+
+static int find_gid(struct posix_acl_state *state, kgid_t gid)
+{
+	struct posix_ace_state_array *a = state->groups;
+	int i;
+
+	for (i = 0; i < a->n; i++)
+		if (gid_eq(a->aces[i].gid, gid))
+			return i;
+	/* Not found: */
+	a->n++;
+	a->aces[i].gid = gid;
+	a->aces[i].perms.allow = state->everyone.allow;
+	a->aces[i].perms.deny  = state->everyone.deny;
+
+	return i;
+}
+
+static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
+{
+	int i;
+
+	for (i=0; i < a->n; i++)
+		deny_bits(&a->aces[i].perms, mask);
+}
+
+static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
+{
+	int i;
+
+	for (i=0; i < a->n; i++)
+		allow_bits(&a->aces[i].perms, mask);
+}
+
+static void process_one_v4_ace(struct posix_acl_state *state,
+				struct nfs4_ace *ace)
+{
+	u32 mask = ace->access_mask;
+	short type = ace2type(ace);
+	int i;
+
+	state->valid |= type;
+
+	switch (type) {
+	case ACL_USER_OBJ:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->owner, mask);
+		} else {
+			deny_bits(&state->owner, mask);
+		}
+		break;
+	case ACL_USER:
+		i = find_uid(state, ace->who_uid);
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->users->aces[i].perms, mask);
+		} else {
+			deny_bits(&state->users->aces[i].perms, mask);
+			mask = state->users->aces[i].perms.deny;
+			deny_bits(&state->owner, mask);
+		}
+		break;
+	case ACL_GROUP_OBJ:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->group, mask);
+		} else {
+			deny_bits(&state->group, mask);
+			mask = state->group.deny;
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+		break;
+	case ACL_GROUP:
+		i = find_gid(state, ace->who_gid);
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->groups->aces[i].perms, mask);
+		} else {
+			deny_bits(&state->groups->aces[i].perms, mask);
+			mask = state->groups->aces[i].perms.deny;
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->group, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+		break;
+	case ACL_OTHER:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->owner, mask);
+			allow_bits(&state->group, mask);
+			allow_bits(&state->other, mask);
+			allow_bits(&state->everyone, mask);
+			allow_bits_array(state->users, mask);
+			allow_bits_array(state->groups, mask);
+		} else {
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->group, mask);
+			deny_bits(&state->other, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+	}
+}
+
+static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
+		struct posix_acl **pacl, struct posix_acl **dpacl,
+		unsigned int flags)
+{
+	struct posix_acl_state effective_acl_state, default_acl_state;
+	struct nfs4_ace *ace;
+	int ret;
+
+	ret = init_state(&effective_acl_state, acl->naces);
+	if (ret)
+		return ret;
+	ret = init_state(&default_acl_state, acl->naces);
+	if (ret)
+		goto out_estate;
+	ret = -EINVAL;
+	for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
+		if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
+		    ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
+			goto out_dstate;
+		if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
+			goto out_dstate;
+		if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
+			process_one_v4_ace(&effective_acl_state, ace);
+			continue;
+		}
+		if (!(flags & NFS4_ACL_DIR))
+			goto out_dstate;
+		/*
+		 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
+		 * is set, we're effectively turning on the other.  That's OK,
+		 * according to rfc 3530.
+		 */
+		process_one_v4_ace(&default_acl_state, ace);
+
+		if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
+			process_one_v4_ace(&effective_acl_state, ace);
+	}
+
+	/*
+	 * At this point, the default ACL may have zeroed-out entries for owner,
+	 * group and other. That usually results in a non-sensical resulting ACL
+	 * that denies all access except to any ACE that was explicitly added.
+	 *
+	 * The setfacl command solves a similar problem with this logic:
+	 *
+	 * "If  a  Default  ACL  entry is created, and the Default ACL contains
+	 *  no owner, owning group, or others entry,  a  copy of  the  ACL
+	 *  owner, owning group, or others entry is added to the Default ACL."
+	 *
+	 * Copy any missing ACEs from the effective set, if any ACEs were
+	 * explicitly set.
+	 */
+	if (default_acl_state.valid) {
+		if (!(default_acl_state.valid & ACL_USER_OBJ))
+			default_acl_state.owner = effective_acl_state.owner;
+		if (!(default_acl_state.valid & ACL_GROUP_OBJ))
+			default_acl_state.group = effective_acl_state.group;
+		if (!(default_acl_state.valid & ACL_OTHER))
+			default_acl_state.other = effective_acl_state.other;
+	}
+
+	*pacl = posix_state_to_acl(&effective_acl_state, flags);
+	if (IS_ERR(*pacl)) {
+		ret = PTR_ERR(*pacl);
+		*pacl = NULL;
+		goto out_dstate;
+	}
+	*dpacl = posix_state_to_acl(&default_acl_state,
+						flags | NFS4_ACL_TYPE_DEFAULT);
+	if (IS_ERR(*dpacl)) {
+		ret = PTR_ERR(*dpacl);
+		*dpacl = NULL;
+		posix_acl_release(*pacl);
+		*pacl = NULL;
+		goto out_dstate;
+	}
+	sort_pacl(*pacl);
+	sort_pacl(*dpacl);
+	ret = 0;
+out_dstate:
+	free_state(&default_acl_state);
+out_estate:
+	free_state(&effective_acl_state);
+	return ret;
+}
+
+__be32 nfsd4_acl_to_attr(enum nfs_ftype4 type, struct nfs4_acl *acl,
+			 struct nfsd_attrs *attr)
+{
+	int host_error;
+	unsigned int flags = 0;
+
+	if (!acl)
+		return nfs_ok;
+
+	if (type == NF4DIR)
+		flags = NFS4_ACL_DIR;
+
+	host_error = nfs4_acl_nfsv4_to_posix(acl, &attr->na_pacl,
+					     &attr->na_dpacl, flags);
+	if (host_error == -EINVAL)
+		return nfserr_attrnotsupp;
+	else
+		return nfserrno(host_error);
+}
+
+static short
+ace2type(struct nfs4_ace *ace)
+{
+	switch (ace->whotype) {
+		case NFS4_ACL_WHO_NAMED:
+			return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
+					ACL_GROUP : ACL_USER);
+		case NFS4_ACL_WHO_OWNER:
+			return ACL_USER_OBJ;
+		case NFS4_ACL_WHO_GROUP:
+			return ACL_GROUP_OBJ;
+		case NFS4_ACL_WHO_EVERYONE:
+			return ACL_OTHER;
+	}
+	BUG();
+	return -1;
+}
+
+/*
+ * return the size of the struct nfs4_acl required to represent an acl
+ * with @entries entries.
+ */
+int nfs4_acl_bytes(int entries)
+{
+	return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
+}
+
+static struct {
+	char *string;
+	int   stringlen;
+	int type;
+} s2t_map[] = {
+	{
+		.string    = "OWNER@",
+		.stringlen = sizeof("OWNER@") - 1,
+		.type      = NFS4_ACL_WHO_OWNER,
+	},
+	{
+		.string    = "GROUP@",
+		.stringlen = sizeof("GROUP@") - 1,
+		.type      = NFS4_ACL_WHO_GROUP,
+	},
+	{
+		.string    = "EVERYONE@",
+		.stringlen = sizeof("EVERYONE@") - 1,
+		.type      = NFS4_ACL_WHO_EVERYONE,
+	},
+};
+
+int
+nfs4_acl_get_whotype(char *p, u32 len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
+		if (s2t_map[i].stringlen == len &&
+				0 == memcmp(s2t_map[i].string, p, len))
+			return s2t_map[i].type;
+	}
+	return NFS4_ACL_WHO_NAMED;
+}
+
+__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
+{
+	__be32 *p;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
+		if (s2t_map[i].type != who)
+			continue;
+		p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
+		if (!p)
+			return nfserr_resource;
+		p = xdr_encode_opaque(p, s2t_map[i].string,
+					s2t_map[i].stringlen);
+		return 0;
+	}
+	WARN_ON_ONCE(1);
+	return nfserr_serverfault;
+}
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
new file mode 100644
index 000000000..19dc33750
--- /dev/null
+++ b/fs/nfsd/nfs4callback.c
@@ -0,0 +1,2018 @@
+/*
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/nfs4.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/slab.h>
+#include "nfsd.h"
+#include "state.h"
+#include "netns.h"
+#include "stats.h"
+#include "trace.h"
+#include "xdr4cb.h"
+#include "xdr4.h"
+#include "nfs4xdr_gen.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+#define NFSPROC4_CB_NULL 0
+#define NFSPROC4_CB_COMPOUND 1
+
+/* Index of predefined Linux callback client operations */
+
+struct nfs4_cb_compound_hdr {
+	/* args */
+	u32		ident;	/* minorversion 0 only */
+	u32		nops;
+	__be32		*nops_p;
+	u32		minorversion;
+	/* res */
+	int		status;
+};
+
+static __be32 *xdr_encode_empty_array(__be32 *p)
+{
+	*p++ = xdr_zero;
+	return p;
+}
+
+/*
+ * Encode/decode NFSv4 CB basic data types
+ *
+ * Basic NFSv4 callback data types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section
+ * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
+ * 1 Protocol"
+ */
+
+static void encode_uint32(struct xdr_stream *xdr, u32 n)
+{
+	WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
+}
+
+static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
+			   size_t len)
+{
+	xdr_stream_encode_uint32_array(xdr, bitmap, len);
+}
+
+static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
+				struct nfs4_cb_fattr *fattr)
+{
+	fattr->ncf_cb_change = 0;
+	fattr->ncf_cb_fsize = 0;
+	fattr->ncf_cb_atime.tv_sec = 0;
+	fattr->ncf_cb_atime.tv_nsec = 0;
+	fattr->ncf_cb_mtime.tv_sec = 0;
+	fattr->ncf_cb_mtime.tv_nsec = 0;
+
+	if (bitmap[0] & FATTR4_WORD0_CHANGE)
+		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
+			return -EIO;
+	if (bitmap[0] & FATTR4_WORD0_SIZE)
+		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
+			return -EIO;
+	if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
+		fattr4_time_deleg_access access;
+
+		if (!xdrgen_decode_fattr4_time_deleg_access(xdr, &access))
+			return -EIO;
+		if (access.nseconds >= NSEC_PER_SEC)
+			return -EIO;
+		fattr->ncf_cb_atime.tv_sec = access.seconds;
+		fattr->ncf_cb_atime.tv_nsec = access.nseconds;
+
+	}
+	if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
+		fattr4_time_deleg_modify modify;
+
+		if (!xdrgen_decode_fattr4_time_deleg_modify(xdr, &modify))
+			return -EIO;
+		if (modify.nseconds >= NSEC_PER_SEC)
+			return -EIO;
+		fattr->ncf_cb_mtime.tv_sec = modify.seconds;
+		fattr->ncf_cb_mtime.tv_nsec = modify.nseconds;
+
+	}
+	return 0;
+}
+
+static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(op);
+}
+
+/*
+ * nfs_fh4
+ *
+ *	typedef opaque nfs_fh4<NFS4_FHSIZE>;
+ */
+static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
+{
+	u32 length = fh->fh_size;
+	__be32 *p;
+
+	BUG_ON(length > NFS4_FHSIZE);
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, &fh->fh_raw, length);
+}
+
+/*
+ * stateid4
+ *
+ *	struct stateid4 {
+ *		uint32_t	seqid;
+ *		opaque		other[12];
+ *	};
+ */
+static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
+	*p++ = cpu_to_be32(sid->si_generation);
+	xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
+}
+
+/*
+ * sessionid4
+ *
+ *	typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
+ */
+static void encode_sessionid4(struct xdr_stream *xdr,
+			      const struct nfsd4_session *session)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
+	xdr_encode_opaque_fixed(p, session->se_sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+}
+
+/*
+ * nfsstat4
+ */
+static const struct {
+	int stat;
+	int errno;
+} nfs_cb_errtbl[] = {
+	{ NFS4_OK,		0		},
+	{ NFS4ERR_PERM,		-EPERM		},
+	{ NFS4ERR_NOENT,	-ENOENT		},
+	{ NFS4ERR_IO,		-EIO		},
+	{ NFS4ERR_NXIO,		-ENXIO		},
+	{ NFS4ERR_ACCESS,	-EACCES		},
+	{ NFS4ERR_EXIST,	-EEXIST		},
+	{ NFS4ERR_XDEV,		-EXDEV		},
+	{ NFS4ERR_NOTDIR,	-ENOTDIR	},
+	{ NFS4ERR_ISDIR,	-EISDIR		},
+	{ NFS4ERR_INVAL,	-EINVAL		},
+	{ NFS4ERR_FBIG,		-EFBIG		},
+	{ NFS4ERR_NOSPC,	-ENOSPC		},
+	{ NFS4ERR_ROFS,		-EROFS		},
+	{ NFS4ERR_MLINK,	-EMLINK		},
+	{ NFS4ERR_NAMETOOLONG,	-ENAMETOOLONG	},
+	{ NFS4ERR_NOTEMPTY,	-ENOTEMPTY	},
+	{ NFS4ERR_DQUOT,	-EDQUOT		},
+	{ NFS4ERR_STALE,	-ESTALE		},
+	{ NFS4ERR_BADHANDLE,	-EBADHANDLE	},
+	{ NFS4ERR_BAD_COOKIE,	-EBADCOOKIE	},
+	{ NFS4ERR_NOTSUPP,	-ENOTSUPP	},
+	{ NFS4ERR_TOOSMALL,	-ETOOSMALL	},
+	{ NFS4ERR_SERVERFAULT,	-ESERVERFAULT	},
+	{ NFS4ERR_BADTYPE,	-EBADTYPE	},
+	{ NFS4ERR_LOCKED,	-EAGAIN		},
+	{ NFS4ERR_RESOURCE,	-EREMOTEIO	},
+	{ NFS4ERR_SYMLINK,	-ELOOP		},
+	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
+	{ NFS4ERR_DEADLOCK,	-EDEADLK	},
+	{ -1,			-EIO		}
+};
+
+/*
+ * If we cannot translate the error, the recovery routines should
+ * handle it.
+ *
+ * Note: remaining NFSv4 error codes have values > 10000, so should
+ * not conflict with native Linux error codes.
+ */
+static int nfs_cb_stat_to_errno(int status)
+{
+	int i;
+
+	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
+		if (nfs_cb_errtbl[i].stat == status)
+			return nfs_cb_errtbl[i].errno;
+	}
+
+	dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
+	return -status;
+}
+
+static int decode_cb_op_status(struct xdr_stream *xdr,
+			       enum nfs_cb_opnum4 expected, int *status)
+{
+	__be32 *p;
+	u32 op;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	op = be32_to_cpup(p++);
+	if (unlikely(op != expected))
+		goto out_unexpected;
+	*status = nfs_cb_stat_to_errno(be32_to_cpup(p));
+	return 0;
+out_overflow:
+	return -EIO;
+out_unexpected:
+	dprintk("NFSD: Callback server returned operation %d but "
+		"we issued a request for %d\n", op, expected);
+	return -EIO;
+}
+
+/*
+ * CB_COMPOUND4args
+ *
+ *	struct CB_COMPOUND4args {
+ *		utf8str_cs	tag;
+ *		uint32_t	minorversion;
+ *		uint32_t	callback_ident;
+ *		nfs_cb_argop4	argarray<>;
+ *	};
+*/
+static void encode_cb_compound4args(struct xdr_stream *xdr,
+				    struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 * p;
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
+	p = xdr_encode_empty_array(p);		/* empty tag */
+	*p++ = cpu_to_be32(hdr->minorversion);
+	*p++ = cpu_to_be32(hdr->ident);
+
+	hdr->nops_p = p;
+	*p = cpu_to_be32(hdr->nops);		/* argarray element count */
+}
+
+/*
+ * Update argarray element count
+ */
+static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
+{
+	BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
+	*hdr->nops_p = cpu_to_be32(hdr->nops);
+}
+
+/*
+ * CB_COMPOUND4res
+ *
+ *	struct CB_COMPOUND4res {
+ *		nfsstat4	status;
+ *		utf8str_cs	tag;
+ *		nfs_cb_resop4	resarray<>;
+ *	};
+ */
+static int decode_cb_compound4res(struct xdr_stream *xdr,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	hdr->status = be32_to_cpup(p);
+	/* Ignore the tag */
+	if (xdr_stream_decode_u32(xdr, &length) < 0)
+		goto out_overflow;
+	if (xdr_inline_decode(xdr, length) == NULL)
+		goto out_overflow;
+	if (xdr_stream_decode_u32(xdr, &hdr->nops) < 0)
+		goto out_overflow;
+	return 0;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ * CB_RECALL4args
+ *
+ *	struct CB_RECALL4args {
+ *		stateid4	stateid;
+ *		bool		truncate;
+ *		nfs_fh4		fh;
+ *	};
+ */
+static void encode_cb_recall4args(struct xdr_stream *xdr,
+				  const struct nfs4_delegation *dp,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
+	encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = xdr_zero;			/* truncate */
+
+	encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
+
+	hdr->nops++;
+}
+
+/*
+ * CB_RECALLANY4args
+ *
+ *	struct CB_RECALLANY4args {
+ *		uint32_t	craa_objects_to_keep;
+ *		bitmap4		craa_type_mask;
+ *	};
+ */
+static void
+encode_cb_recallany4args(struct xdr_stream *xdr,
+	struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
+{
+	encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
+	encode_uint32(xdr, ra->ra_keep);
+	encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
+	hdr->nops++;
+}
+
+/*
+ * CB_GETATTR4args
+ *	struct CB_GETATTR4args {
+ *	   nfs_fh4 fh;
+ *	   bitmap4 attr_request;
+ *	};
+ *
+ * The size and change attributes are the only one
+ * guaranteed to be serviced by the client.
+ */
+static void
+encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
+			struct nfs4_cb_fattr *fattr)
+{
+	struct nfs4_delegation *dp = container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
+	struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
+	struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
+	u32 bmap_size = 1;
+	u32 bmap[3];
+
+	bmap[0] = FATTR4_WORD0_SIZE;
+	if (!ncf->ncf_file_modified)
+		bmap[0] |= FATTR4_WORD0_CHANGE;
+
+	if (deleg_attrs_deleg(dp->dl_type)) {
+		bmap[1] = 0;
+		bmap[2] = FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY;
+		bmap_size = 3;
+	}
+	encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR);
+	encode_nfs_fh4(xdr, fh);
+	encode_bitmap4(xdr, bmap, bmap_size);
+	hdr->nops++;
+}
+
+static u32 highest_slotid(struct nfsd4_session *ses)
+{
+	u32 idx;
+
+	spin_lock(&ses->se_lock);
+	idx = fls(~ses->se_cb_slot_avail);
+	if (idx > 0)
+		--idx;
+	idx = max(idx, ses->se_cb_highest_slot);
+	spin_unlock(&ses->se_lock);
+	return idx;
+}
+
+static void
+encode_referring_call4(struct xdr_stream *xdr,
+		       const struct nfsd4_referring_call *rc)
+{
+	encode_uint32(xdr, rc->rc_sequenceid);
+	encode_uint32(xdr, rc->rc_slotid);
+}
+
+static void
+encode_referring_call_list4(struct xdr_stream *xdr,
+			    const struct nfsd4_referring_call_list *rcl)
+{
+	struct nfsd4_referring_call *rc;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
+	xdr_encode_opaque_fixed(p, rcl->rcl_sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	encode_uint32(xdr, rcl->__nr_referring_calls);
+	list_for_each_entry(rc, &rcl->rcl_referring_calls, __list)
+		encode_referring_call4(xdr, rc);
+}
+
+/*
+ * CB_SEQUENCE4args
+ *
+ *	struct CB_SEQUENCE4args {
+ *		sessionid4		csa_sessionid;
+ *		sequenceid4		csa_sequenceid;
+ *		slotid4			csa_slotid;
+ *		slotid4			csa_highest_slotid;
+ *		bool			csa_cachethis;
+ *		referring_call_list4	csa_referring_call_lists<>;
+ *	};
+ */
+static void encode_cb_sequence4args(struct xdr_stream *xdr,
+				    const struct nfsd4_callback *cb,
+				    struct nfs4_cb_compound_hdr *hdr)
+{
+	struct nfsd4_session *session;
+	struct nfsd4_referring_call_list *rcl;
+	__be32 *p;
+
+	if (hdr->minorversion == 0)
+		return;
+
+	rcu_read_lock();
+	session = rcu_dereference(cb->cb_clp->cl_cb_session);
+	if (!session) {
+		rcu_read_unlock();
+		return;
+	}
+
+	encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
+	encode_sessionid4(xdr, session);
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 4);
+	*p++ = cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]);	/* csa_sequenceid */
+	*p++ = cpu_to_be32(cb->cb_held_slot);		/* csa_slotid */
+	*p++ = cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */
+	*p++ = xdr_zero;			/* csa_cachethis */
+
+	/* csa_referring_call_lists */
+	encode_uint32(xdr, cb->cb_nr_referring_call_list);
+	list_for_each_entry(rcl, &cb->cb_referring_call_list, __list)
+		encode_referring_call_list4(xdr, rcl);
+
+	hdr->nops++;
+	rcu_read_unlock();
+}
+
+static void update_cb_slot_table(struct nfsd4_session *ses, u32 target)
+{
+	/* No need to do anything if nothing changed */
+	if (likely(target == READ_ONCE(ses->se_cb_highest_slot)))
+		return;
+
+	spin_lock(&ses->se_lock);
+	if (target > ses->se_cb_highest_slot) {
+		int i;
+
+		target = min(target, NFSD_BC_SLOT_TABLE_SIZE - 1);
+
+		/*
+		 * Growing the slot table. Reset any new sequences to 1.
+		 *
+		 * NB: There is some debate about whether the RFC requires this,
+		 *     but the Linux client expects it.
+		 */
+		for (i = ses->se_cb_highest_slot + 1; i <= target; ++i)
+			ses->se_cb_seq_nr[i] = 1;
+	}
+	ses->se_cb_highest_slot = target;
+	spin_unlock(&ses->se_lock);
+}
+
+/*
+ * CB_SEQUENCE4resok
+ *
+ *	struct CB_SEQUENCE4resok {
+ *		sessionid4	csr_sessionid;
+ *		sequenceid4	csr_sequenceid;
+ *		slotid4		csr_slotid;
+ *		slotid4		csr_highest_slotid;
+ *		slotid4		csr_target_highest_slotid;
+ *	};
+ *
+ *	union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
+ *	case NFS4_OK:
+ *		CB_SEQUENCE4resok	csr_resok4;
+ *	default:
+ *		void;
+ *	};
+ *
+ * Our current back channel implmentation supports a single backchannel
+ * with a single slot.
+ */
+static int decode_cb_sequence4resok(struct xdr_stream *xdr,
+				    struct nfsd4_callback *cb)
+{
+	struct nfsd4_session *session;
+	int status = -ESERVERFAULT;
+	__be32 *p;
+	u32 seqid, slotid, target;
+
+	rcu_read_lock();
+	session = rcu_dereference(cb->cb_clp->cl_cb_session);
+	if (!session) {
+		rcu_read_unlock();
+		cb->cb_seq_status = -NFS4ERR_BADSESSION;
+		return -NFS4ERR_BADSESSION;
+	}
+
+	/*
+	 * If the server returns different values for sessionID, slotID or
+	 * sequence number, the server is looney tunes.
+	 */
+	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
+	if (unlikely(p == NULL)) {
+		rcu_read_unlock();
+		goto out_overflow;
+	}
+
+	if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
+		dprintk("NFS: %s Invalid session id\n", __func__);
+		rcu_read_unlock();
+		goto out;
+	}
+	p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
+
+	seqid = be32_to_cpup(p++);
+	if (seqid != session->se_cb_seq_nr[cb->cb_held_slot]) {
+		dprintk("NFS: %s Invalid sequence number\n", __func__);
+		rcu_read_unlock();
+		goto out;
+	}
+
+	slotid = be32_to_cpup(p++);
+	if (slotid != cb->cb_held_slot) {
+		dprintk("NFS: %s Invalid slotid\n", __func__);
+		rcu_read_unlock();
+		goto out;
+	}
+
+	p++; // ignore current highest slot value
+
+	target = be32_to_cpup(p++);
+	update_cb_slot_table(session, target);
+	rcu_read_unlock();
+	status = 0;
+out:
+	cb->cb_seq_status = status;
+	return status;
+out_overflow:
+	status = -EIO;
+	goto out;
+}
+
+static int decode_cb_sequence4res(struct xdr_stream *xdr,
+				  struct nfsd4_callback *cb)
+{
+	int status;
+
+	if (cb->cb_clp->cl_minorversion == 0)
+		return 0;
+
+	status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_sequence4resok(xdr, cb);
+}
+
+/*
+ * NFSv4.0 and NFSv4.1 XDR encode functions
+ *
+ * NFSv4.0 callback argument types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section 20
+ * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
+ * Protocol".
+ */
+
+/*
+ * NB: Without this zero space reservation, callbacks over krb5p fail
+ */
+static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *__unused)
+{
+	xdr_reserve_space(xdr, 0);
+}
+
+/*
+ * 20.1.  Operation 3: CB_GETATTR - Get Attributes
+ */
+static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
+		struct xdr_stream *xdr, const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	struct nfs4_cb_fattr *ncf =
+		container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = cb->cb_clp->cl_cb_ident,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_getattr4args(xdr, &hdr, ncf);
+	encode_cb_nops(&hdr);
+}
+
+/*
+ * 20.2. Operation 4: CB_RECALL - Recall a Delegation
+ */
+static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfs4_delegation *dp = cb_to_delegation(cb);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = cb->cb_clp->cl_cb_ident,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_recall4args(xdr, dp, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+/*
+ * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
+ */
+static void
+nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
+		struct xdr_stream *xdr, const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	struct nfsd4_cb_recall_any *ra;
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = cb->cb_clp->cl_cb_ident,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_recallany4args(xdr, &hdr, ra);
+	encode_cb_nops(&hdr);
+}
+
+/*
+ * NFSv4.0 and NFSv4.1 XDR decode functions
+ *
+ * NFSv4.0 callback result types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section 20
+ * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
+ * Protocol".
+ */
+
+static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
+				void *__unused)
+{
+	return 0;
+}
+
+/*
+ * 20.1.  Operation 3: CB_GETATTR - Get Attributes
+ */
+static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+	u32 bitmap[3] = {0};
+	u32 attrlen, maxlen;
+	struct nfs4_cb_fattr *ncf =
+		container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status);
+	if (unlikely(status || cb->cb_status))
+		return status;
+	if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
+		return -EIO;
+	if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
+		return -EIO;
+	maxlen = sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize);
+	if (bitmap[2] != 0)
+		maxlen += (sizeof(ncf->ncf_cb_mtime.tv_sec) +
+			   sizeof(ncf->ncf_cb_mtime.tv_nsec)) * 2;
+	if (attrlen > maxlen)
+		return -EIO;
+	status = decode_cb_fattr4(xdr, bitmap, ncf);
+	return status;
+}
+
+/*
+ * 20.2. Operation 4: CB_RECALL - Recall a Delegation
+ */
+static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
+}
+
+/*
+ * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
+ */
+static int
+nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+	status =  decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
+	return status;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+/*
+ * CB_LAYOUTRECALL4args
+ *
+ *	struct layoutrecall_file4 {
+ *		nfs_fh4         lor_fh;
+ *		offset4         lor_offset;
+ *		length4         lor_length;
+ *		stateid4        lor_stateid;
+ *	};
+ *
+ *	union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
+ *	case LAYOUTRECALL4_FILE:
+ *		layoutrecall_file4 lor_layout;
+ *	case LAYOUTRECALL4_FSID:
+ *		fsid4              lor_fsid;
+ *	case LAYOUTRECALL4_ALL:
+ *		void;
+ *	};
+ *
+ *	struct CB_LAYOUTRECALL4args {
+ *		layouttype4             clora_type;
+ *		layoutiomode4           clora_iomode;
+ *		bool                    clora_changed;
+ *		layoutrecall4           clora_recall;
+ *	};
+ */
+static void encode_cb_layout4args(struct xdr_stream *xdr,
+				  const struct nfs4_layout_stateid *ls,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	BUG_ON(hdr->minorversion == 0);
+
+	p = xdr_reserve_space(xdr, 5 * 4);
+	*p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
+	*p++ = cpu_to_be32(ls->ls_layout_type);
+	*p++ = cpu_to_be32(IOMODE_ANY);
+	*p++ = cpu_to_be32(1);
+	*p = cpu_to_be32(RETURN_FILE);
+
+	encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
+
+	p = xdr_reserve_space(xdr, 2 * 8);
+	p = xdr_encode_hyper(p, 0);
+	xdr_encode_hyper(p, NFS4_MAX_UINT64);
+
+	encode_stateid4(xdr, &ls->ls_recall_sid);
+
+	hdr->nops++;
+}
+
+static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_layout4args(xdr, ls, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
+{
+	__be32	*p;
+
+	p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
+	p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
+	xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
+}
+
+static void nfs4_xdr_enc_cb_notify(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb);
+	struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+	struct CB_NOTIFY4args args;
+	unsigned int start;
+
+	WARN_ON_ONCE(hdr.minorversion == 0);
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+
+	/*
+	 * nfsd4_cb_notify_prepare() sized the payload against a single page,
+	 * but did not account for the compound, sequence, stateid, and
+	 * filehandle encoded here. If the variable-length encode overflows the
+	 * backchannel send buffer, roll back to before the operation so that a
+	 * truncated CB_NOTIFY is never placed on the wire.
+	 */
+	start = xdr_stream_pos(xdr);
+
+	if (xdr_stream_encode_u32(xdr, OP_CB_NOTIFY) < 0)
+		goto out_err;
+
+	args.cna_stateid.seqid = dp->dl_stid.sc_stateid.si_generation;
+	memcpy(&args.cna_stateid.other, &dp->dl_stid.sc_stateid.si_opaque,
+	       ARRAY_SIZE(args.cna_stateid.other));
+	args.cna_fh.len = dp->dl_stid.sc_file->fi_fhandle.fh_size;
+	args.cna_fh.data = dp->dl_stid.sc_file->fi_fhandle.fh_raw;
+	args.cna_changes.count = ncn->ncn_nf_cnt;
+	args.cna_changes.element = ncn->ncn_nf;
+	if (!xdrgen_encode_CB_NOTIFY4args(xdr, &args))
+		goto out_err;
+
+	hdr.nops++;
+	encode_cb_nops(&hdr);
+	return;
+
+out_err:
+	/*
+	 * Drop the CB_NOTIFY op and emit a valid CB_SEQUENCE-only compound so
+	 * the client still advances its slot. Flag the failure so the done
+	 * handler recalls the delegation and the missed notification is not
+	 * silently lost. The flag is written here in the transmit path and read
+	 * in the done handler; the two are serialized phases of the same
+	 * rpc_task, so no additional barrier is needed.
+	 */
+	ncn->ncn_encode_err = true;
+	xdr_truncate_encode(xdr, start);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_notify(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_NOTIFY, &cb->cb_status);
+}
+
+static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfsd4_blocked_lock *nbl =
+		container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.c.flc_owner;
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	__be32 *p;
+
+	BUG_ON(hdr.minorversion == 0);
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
+	encode_nfs_fh4(xdr, &nbl->nbl_fh);
+	encode_stateowner(xdr, &lo->lo_owner);
+	hdr.nops++;
+
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
+}
+
+/*
+ * struct write_response4 {
+ *	stateid4	wr_callback_id<1>;
+ *	length4		wr_count;
+ *	stable_how4	wr_committed;
+ *	verifier4	wr_writeverf;
+ * };
+ * union offload_info4 switch (nfsstat4 coa_status) {
+ *	case NFS4_OK:
+ *		write_response4	coa_resok4;
+ *	default:
+ *		length4		coa_bytes_copied;
+ * };
+ * struct CB_OFFLOAD4args {
+ *	nfs_fh4		coa_fh;
+ *	stateid4	coa_stateid;
+ *	offload_info4	coa_offload_info;
+ * };
+ */
+static void encode_offload_info4(struct xdr_stream *xdr,
+				 const struct nfsd4_cb_offload *cbo)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cbo->co_nfserr;
+	switch (cbo->co_nfserr) {
+	case nfs_ok:
+		p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
+		p = xdr_encode_empty_array(p);
+		p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
+		*p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
+		p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
+					    NFS4_VERIFIER_SIZE);
+		break;
+	default:
+		p = xdr_reserve_space(xdr, 8);
+		/* We always return success if bytes were written */
+		p = xdr_encode_hyper(p, 0);
+	}
+}
+
+static void encode_cb_offload4args(struct xdr_stream *xdr,
+				   const struct nfsd4_cb_offload *cbo,
+				   struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(OP_CB_OFFLOAD);
+	encode_nfs_fh4(xdr, &cbo->co_fh);
+	encode_stateid4(xdr, &cbo->co_res.cb_stateid);
+	encode_offload_info4(xdr, cbo);
+
+	hdr->nops++;
+}
+
+static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfsd4_cb_offload *cbo =
+		container_of(cb, struct nfsd4_cb_offload, co_cb);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_offload4args(xdr, cbo, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
+}
+/*
+ * RPC procedure tables
+ */
+#define PROC(proc, call, argtype, restype)				\
+[NFSPROC4_CLNT_##proc] = {						\
+	.p_proc    = NFSPROC4_CB_##call,				\
+	.p_encode  = nfs4_xdr_enc_##argtype,		\
+	.p_decode  = nfs4_xdr_dec_##restype,				\
+	.p_arglen  = NFS4_enc_##argtype##_sz,				\
+	.p_replen  = NFS4_dec_##restype##_sz,				\
+	.p_statidx = NFSPROC4_CLNT_##proc,				\
+	.p_name    = #proc,						\
+}
+
+static const struct rpc_procinfo nfs4_cb_procedures[] = {
+	PROC(CB_NULL,	NULL,		cb_null,	cb_null),
+	PROC(CB_RECALL,	COMPOUND,	cb_recall,	cb_recall),
+#ifdef CONFIG_NFSD_PNFS
+	PROC(CB_LAYOUT,	COMPOUND,	cb_layout,	cb_layout),
+#endif
+	PROC(CB_NOTIFY,		COMPOUND,	cb_notify,	cb_notify),
+	PROC(CB_NOTIFY_LOCK,	COMPOUND,	cb_notify_lock,	cb_notify_lock),
+	PROC(CB_OFFLOAD,	COMPOUND,	cb_offload,	cb_offload),
+	PROC(CB_RECALL_ANY,	COMPOUND,	cb_recall_any,	cb_recall_any),
+	PROC(CB_GETATTR,	COMPOUND,	cb_getattr,	cb_getattr),
+};
+
+#define NFS4_CB_PROGRAM	0x40000000
+#define NFS4_CB_VERSION	1
+
+struct nfsd_net_cb {
+	struct rpc_version	version4;
+	const struct rpc_version *versions[NFS4_CB_VERSION + 1];
+	struct rpc_program	program;
+	struct rpc_stat		stat;
+};
+
+static int max_cb_time(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	/*
+	 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
+	 * so we can use 32-bit math on it. Warn if that assumption
+	 * ever stops being true.
+	 */
+	if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
+		return 360 * HZ;
+
+	return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
+}
+
+static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	trace_nfsd_cb_queue(clp, cb);
+	return queue_work(clp->cl_callback_wq, &cb->cb_work);
+}
+
+static void nfsd4_requeue_cb(struct rpc_task *task, struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
+		trace_nfsd_cb_restart(clp, cb);
+		task->tk_status = 0;
+		set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags);
+	}
+}
+
+static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
+{
+	atomic_inc(&clp->cl_cb_inflight);
+}
+
+static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
+{
+
+	atomic_dec_and_wake_up(&clp->cl_cb_inflight);
+}
+
+static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
+{
+	wait_var_event(&clp->cl_cb_inflight,
+			!atomic_read(&clp->cl_cb_inflight));
+}
+
+static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
+{
+	if (clp->cl_minorversion == 0) {
+		client->cl_principal = clp->cl_cred.cr_targ_princ ?
+			clp->cl_cred.cr_targ_princ : "nfs";
+
+		return get_cred(rpc_machine_cred());
+	} else {
+		struct cred *kcred;
+
+		kcred = prepare_kernel_cred(&init_task);
+		if (!kcred)
+			return NULL;
+
+		kcred->fsuid = ses->se_cb_sec.uid;
+		kcred->fsgid = ses->se_cb_sec.gid;
+		return kcred;
+	}
+}
+
+static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	int maxtime = max_cb_time(clp->net);
+	struct rpc_timeout	timeparms = {
+		.to_initval	= maxtime,
+		.to_retries	= 0,
+		.to_maxval	= maxtime,
+	};
+	struct rpc_create_args args = {
+		.net		= clp->net,
+		.address	= (struct sockaddr *) &conn->cb_addr,
+		.addrsize	= conn->cb_addrlen,
+		.saddress	= (struct sockaddr *) &conn->cb_saddr,
+		.timeout	= &timeparms,
+		.version	= NFS4_CB_VERSION,
+		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
+		.cred		= current_cred(),
+	};
+	struct rpc_clnt *client;
+	const struct cred *cred;
+
+	args.program = &nn->nfsd_cb->program;
+	if (clp->cl_minorversion == 0) {
+		if (!clp->cl_cred.cr_principal &&
+		    (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
+			trace_nfsd_cb_setup_err(clp, -EINVAL);
+			return -EINVAL;
+		}
+		args.client_name = clp->cl_cred.cr_principal;
+		args.prognumber	= conn->cb_prog;
+		args.protocol = XPRT_TRANSPORT_TCP;
+		args.authflavor = clp->cl_cred.cr_flavor;
+		clp->cl_cb_ident = conn->cb_ident;
+	} else {
+		if (!conn->cb_xprt || !ses)
+			return -EINVAL;
+		args.bc_xprt = conn->cb_xprt;
+		args.prognumber = ses->se_cb_prog;
+		args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
+				XPRT_TRANSPORT_BC;
+		args.authflavor = ses->se_cb_sec.flavor;
+	}
+	/* Create RPC client */
+	client = rpc_create(&args);
+	if (IS_ERR(client)) {
+		trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
+		return PTR_ERR(client);
+	}
+	cred = get_backchannel_cred(clp, client, ses);
+	if (!cred) {
+		trace_nfsd_cb_setup_err(clp, -ENOMEM);
+		rpc_shutdown_client(client);
+		return -ENOMEM;
+	}
+
+	if (clp->cl_minorversion != 0) {
+		clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
+		rcu_assign_pointer(clp->cl_cb_session, ses);
+	}
+	clp->cl_cb_client = client;
+	clp->cl_cb_cred = cred;
+	rcu_read_lock();
+	trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
+			    args.authflavor);
+	rcu_read_unlock();
+	return 0;
+}
+
+static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
+{
+	if (clp->cl_cb_state != newstate) {
+		clp->cl_cb_state = newstate;
+		trace_nfsd_cb_new_state(clp);
+	}
+}
+
+static void nfsd4_mark_cb_down(struct nfs4_client *clp)
+{
+	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
+		return;
+	nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
+}
+
+static void nfsd4_mark_cb_fault(struct nfs4_client *clp)
+{
+	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
+		return;
+	nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
+}
+
+static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
+
+	if (task->tk_status)
+		nfsd4_mark_cb_down(clp);
+	else
+		nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
+}
+
+static void nfsd4_cb_probe_release(void *calldata)
+{
+	struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
+
+	nfsd41_cb_inflight_end(clp);
+
+}
+
+static const struct rpc_call_ops nfsd4_cb_probe_ops = {
+	/* XXX: release method to ensure we set the cb channel down if
+	 * necessary on early failure? */
+	.rpc_call_done = nfsd4_cb_probe_done,
+	.rpc_release = nfsd4_cb_probe_release,
+};
+
+/*
+ * Poke the callback thread to process any updates to the callback
+ * parameters, and send a null probe.
+ */
+void nfsd4_probe_callback(struct nfs4_client *clp)
+{
+	trace_nfsd_cb_probe(clp);
+	nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
+	set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
+	nfsd4_run_cb(&clp->cl_cb_null);
+}
+
+void nfsd4_probe_callback_sync(struct nfs4_client *clp)
+{
+	nfsd4_probe_callback(clp);
+	flush_workqueue(clp->cl_callback_wq);
+}
+
+void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
+{
+	nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
+	spin_lock(&clp->cl_lock);
+	memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
+	spin_unlock(&clp->cl_lock);
+}
+
+static int grab_slot(struct nfsd4_session *ses)
+{
+	int idx;
+
+	spin_lock(&ses->se_lock);
+	idx = ffs(ses->se_cb_slot_avail) - 1;
+	if (idx < 0 || idx > ses->se_cb_highest_slot) {
+		spin_unlock(&ses->se_lock);
+		return -1;
+	}
+	/* clear the bit for the slot */
+	ses->se_cb_slot_avail &= ~BIT(idx);
+	spin_unlock(&ses->se_lock);
+	return idx;
+}
+
+/*
+ * There's currently a single callback channel slot.
+ * If the slot is available, then mark it busy.  Otherwise, set the
+ * thread for sleeping on the callback RPC wait queue.
+ */
+static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd4_session *ses;
+
+	if (cb->cb_held_slot >= 0)
+		return true;
+
+	rcu_read_lock();
+	ses = rcu_dereference(clp->cl_cb_session);
+	if (!ses) {
+		rcu_read_unlock();
+		rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
+		return false;
+	}
+	cb->cb_held_slot = grab_slot(ses);
+	if (cb->cb_held_slot < 0) {
+		rcu_read_unlock();
+		rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
+		/* Race breaker */
+		rcu_read_lock();
+		ses = rcu_dereference(clp->cl_cb_session);
+		if (ses)
+			cb->cb_held_slot = grab_slot(ses);
+		rcu_read_unlock();
+		if (cb->cb_held_slot < 0)
+			return false;
+		rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
+	} else {
+		rcu_read_unlock();
+	}
+	return true;
+}
+
+static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd4_session *ses;
+
+	if (cb->cb_held_slot >= 0) {
+		rcu_read_lock();
+		ses = rcu_dereference(clp->cl_cb_session);
+		if (ses) {
+			spin_lock(&ses->se_lock);
+			ses->se_cb_slot_avail |= BIT(cb->cb_held_slot);
+			spin_unlock(&ses->se_lock);
+		}
+		rcu_read_unlock();
+		cb->cb_held_slot = -1;
+		rpc_wake_up_next(&clp->cl_cb_waitq);
+	}
+}
+
+static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	trace_nfsd_cb_destroy(clp, cb);
+	nfsd41_cb_release_slot(cb);
+	if (test_bit(NFSD4_CALLBACK_WAKE, &cb->cb_flags))
+		clear_and_wake_up_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags);
+	else
+		clear_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags);
+
+	/*
+	 * Order the clear of NFSD4_CALLBACK_RUNNING above before the ->release()
+	 * callback below. A release op may re-check producer-side state to decide
+	 * whether to requeue itself (see nfsd4_cb_notify_release()), and that
+	 * check must not be reordered ahead of the clear. The plain clear_bit()
+	 * path carries no ordering; clear_and_wake_up_bit() already issues this
+	 * barrier internally, so the extra one is harmless there.
+	 */
+	smp_mb__after_atomic();
+
+	if (cb->cb_ops && cb->cb_ops->release)
+		cb->cb_ops->release(cb);
+	nfsd41_cb_inflight_end(clp);
+}
+
+/**
+ * nfsd41_cb_referring_call - add a referring call to a callback operation
+ * @cb: context of callback to add the rc to
+ * @sessionid: referring call's session ID
+ * @slotid: referring call's session slot index
+ * @seqno: referring call's slot sequence number
+ *
+ * Caller serializes access to @cb.
+ *
+ * NB: If memory allocation fails, the referring call is not added.
+ */
+void nfsd41_cb_referring_call(struct nfsd4_callback *cb,
+			      struct nfs4_sessionid *sessionid,
+			      u32 slotid, u32 seqno)
+{
+	struct nfsd4_referring_call_list *rcl;
+	struct nfsd4_referring_call *rc;
+	bool found;
+
+	might_sleep();
+
+	found = false;
+	list_for_each_entry(rcl, &cb->cb_referring_call_list, __list) {
+		if (!memcmp(rcl->rcl_sessionid.data, sessionid->data,
+			   NFS4_MAX_SESSIONID_LEN)) {
+			found = true;
+			break;
+		}
+	}
+	if (!found) {
+		rcl = kmalloc_obj(*rcl);
+		if (!rcl)
+			return;
+		memcpy(rcl->rcl_sessionid.data, sessionid->data,
+		       NFS4_MAX_SESSIONID_LEN);
+		rcl->__nr_referring_calls = 0;
+		INIT_LIST_HEAD(&rcl->rcl_referring_calls);
+		list_add(&rcl->__list, &cb->cb_referring_call_list);
+		cb->cb_nr_referring_call_list++;
+	}
+
+	found = false;
+	list_for_each_entry(rc, &rcl->rcl_referring_calls, __list) {
+		if (rc->rc_sequenceid == seqno && rc->rc_slotid == slotid) {
+			found = true;
+			break;
+		}
+	}
+	if (!found) {
+		rc = kmalloc_obj(*rc);
+		if (!rc)
+			goto out;
+		rc->rc_sequenceid = seqno;
+		rc->rc_slotid = slotid;
+		rcl->__nr_referring_calls++;
+		list_add(&rc->__list, &rcl->rcl_referring_calls);
+	}
+
+out:
+	if (!rcl->__nr_referring_calls) {
+		cb->cb_nr_referring_call_list--;
+		list_del(&rcl->__list);
+		kfree(rcl);
+	}
+}
+
+/**
+ * nfsd41_cb_destroy_referring_call_list - release referring call info
+ * @cb: context of a callback that has completed
+ *
+ * Callers who allocate referring calls using nfsd41_cb_referring_call() must
+ * release those resources by calling nfsd41_cb_destroy_referring_call_list.
+ *
+ * Caller serializes access to @cb.
+ */
+void nfsd41_cb_destroy_referring_call_list(struct nfsd4_callback *cb)
+{
+	struct nfsd4_referring_call_list *rcl;
+	struct nfsd4_referring_call *rc;
+
+	while (!list_empty(&cb->cb_referring_call_list)) {
+		rcl = list_first_entry(&cb->cb_referring_call_list,
+				       struct nfsd4_referring_call_list,
+				       __list);
+
+		while (!list_empty(&rcl->rcl_referring_calls)) {
+			rc = list_first_entry(&rcl->rcl_referring_calls,
+					      struct nfsd4_referring_call,
+					      __list);
+			list_del(&rc->__list);
+			kfree(rc);
+		}
+		list_del(&rcl->__list);
+		kfree(rcl);
+	}
+}
+
+static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+	struct nfs4_client *clp = cb->cb_clp;
+	u32 minorversion = clp->cl_minorversion;
+
+	/*
+	 * cb_seq_status is only set in decode_cb_sequence4res,
+	 * and so will remain 1 if an rpc level failure occurs.
+	 */
+	trace_nfsd_cb_rpc_prepare(clp);
+	cb->cb_seq_status = 1;
+	cb->cb_status = 0;
+	if (minorversion) {
+		if (!rcu_access_pointer(clp->cl_cb_session)) {
+			rpc_exit(task, -EIO);
+			return;
+		}
+		if (!nfsd41_cb_get_slot(cb, task))
+			return;
+	}
+	rpc_call_start(task);
+}
+
+/* Returns true if CB_COMPOUND processing should continue */
+static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
+{
+	struct nfsd4_session *session;
+	bool ret = false;
+
+	if (cb->cb_held_slot < 0)
+		goto requeue;
+
+	rcu_read_lock();
+	session = rcu_dereference(cb->cb_clp->cl_cb_session);
+	if (!session) {
+		rcu_read_unlock();
+		goto requeue;
+	}
+
+	/* This is the operation status code for CB_SEQUENCE */
+	trace_nfsd_cb_seq_status(task, cb, session);
+	switch (cb->cb_seq_status) {
+	case 0:
+		/*
+		 * No need for lock, access serialized in nfsd4_cb_prepare
+		 *
+		 * RFC5661 20.9.3
+		 * If CB_SEQUENCE returns an error, then the state of the slot
+		 * (sequence ID, cached reply) MUST NOT change.
+		 */
+		++session->se_cb_seq_nr[cb->cb_held_slot];
+		ret = true;
+		break;
+	case -ESERVERFAULT:
+		/*
+		 * Call succeeded, but the session, slot index, or slot
+		 * sequence number in the response do not match the same
+		 * in the server's call. The sequence information is thus
+		 * untrustworthy.
+		 */
+		nfsd4_mark_cb_fault(cb->cb_clp);
+		break;
+	case 1:
+		/*
+		 * cb_seq_status remains 1 if an RPC Reply was never
+		 * received. NFSD can't know if the client processed
+		 * the CB_SEQUENCE operation. Ask the client to send a
+		 * DESTROY_SESSION to recover.
+		 */
+		fallthrough;
+	case -NFS4ERR_BADSESSION:
+		nfsd4_mark_cb_fault(cb->cb_clp);
+		rcu_read_unlock();
+		goto requeue;
+	case -NFS4ERR_DELAY:
+		cb->cb_seq_status = 1;
+		if (RPC_SIGNALLED(task) || !rpc_restart_call(task)) {
+			rcu_read_unlock();
+			goto requeue;
+		}
+		rpc_delay(task, 2 * HZ);
+		rcu_read_unlock();
+		return false;
+	case -NFS4ERR_SEQ_MISORDERED:
+	case -NFS4ERR_BADSLOT:
+		/*
+		 * A SEQ_MISORDERED or BADSLOT error means that the client and
+		 * server are out of sync as to the backchannel parameters. Mark
+		 * the backchannel faulty and restart the RPC, but leak the slot
+		 * so that it's no longer used.
+		 */
+		nfsd4_mark_cb_fault(cb->cb_clp);
+		cb->cb_held_slot = -1;
+		rcu_read_unlock();
+		goto retry_nowait;
+	default:
+		nfsd4_mark_cb_fault(cb->cb_clp);
+	}
+	trace_nfsd_cb_free_slot(task, cb, session);
+	rcu_read_unlock();
+	nfsd41_cb_release_slot(cb);
+	return ret;
+retry_nowait:
+	/*
+	 * RPC_SIGNALLED() means that the rpc_client is being torn down and
+	 * (possibly) recreated. Requeue the call in that case.
+	 */
+	if (!RPC_SIGNALLED(task)) {
+		if (rpc_restart_call_prepare(task))
+			return false;
+	}
+requeue:
+	nfsd41_cb_release_slot(cb);
+	nfsd4_requeue_cb(task, cb);
+	return false;
+}
+
+static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+	struct nfs4_client *clp = cb->cb_clp;
+
+	trace_nfsd_cb_rpc_done(clp);
+
+	if (!clp->cl_minorversion) {
+		/*
+		 * If the backchannel connection was shut down while this
+		 * task was queued, we need to resubmit it after setting up
+		 * a new backchannel connection.
+		 *
+		 * Note that if we lost our callback connection permanently
+		 * the submission code will error out, so we don't need to
+		 * handle that case here.
+		 */
+		if (RPC_SIGNALLED(task))
+			nfsd4_requeue_cb(task, cb);
+	} else if (!nfsd4_cb_sequence_done(task, cb)) {
+		return;
+	}
+
+	if (cb->cb_status) {
+		WARN_ONCE(task->tk_status,
+			  "cb_status=%d tk_status=%d cb_opcode=%d",
+			  cb->cb_status, task->tk_status, cb->cb_ops->opcode);
+		task->tk_status = cb->cb_status;
+	}
+
+	switch (cb->cb_ops->done(cb, task)) {
+	case 0:
+		task->tk_status = 0;
+		rpc_restart_call_prepare(task);
+		return;
+	case 1:
+		switch (task->tk_status) {
+		case -EIO:
+		case -ETIMEDOUT:
+		case -EACCES:
+			nfsd4_mark_cb_down(clp);
+		}
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void nfsd4_cb_release(void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+
+	trace_nfsd_cb_rpc_release(cb->cb_clp);
+
+	if (test_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags))
+		nfsd4_queue_cb(cb);
+	else
+		nfsd41_destroy_cb(cb);
+
+}
+
+static const struct rpc_call_ops nfsd4_cb_ops = {
+	.rpc_call_prepare = nfsd4_cb_prepare,
+	.rpc_call_done = nfsd4_cb_done,
+	.rpc_release = nfsd4_cb_release,
+};
+
+/* must be called under the state lock */
+void nfsd4_shutdown_callback(struct nfs4_client *clp)
+{
+	if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
+		trace_nfsd_cb_shutdown(clp);
+
+	set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
+	/*
+	 * Note this won't actually result in a null callback;
+	 * instead, nfsd4_run_cb_null() will detect the killed
+	 * client, destroy the rpc client, and stop:
+	 */
+	nfsd4_run_cb(&clp->cl_cb_null);
+	flush_workqueue(clp->cl_callback_wq);
+	nfsd41_cb_inflight_wait_complete(clp);
+}
+
+static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
+{
+	struct nfsd4_session *s;
+	struct nfsd4_conn *c;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
+		list_for_each_entry(c, &s->se_conns, cn_persession) {
+			if (c->cn_flags & NFS4_CDFC4_BACK)
+				return c;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Note there isn't a lot of locking in this code; instead we depend on
+ * the fact that it is run from clp->cl_callback_wq, which won't run two
+ * work items at once.  So, for example, clp->cl_callback_wq handles all
+ * access of cl_cb_client, and all calls to rpc_create or
+ * rpc_shutdown_client.
+ *
+ * cl_cb_session is written only from cl_callback_wq (via
+ * rcu_assign_pointer) and read from rpciod under rcu_read_lock (via
+ * rcu_dereference) by encode_cb_sequence4args(), decode_cb_sequence4resok(),
+ * nfsd4_cb_sequence_done(), and the cb-slot helpers.  Sessions are freed
+ * with kfree_rcu() so that rpciod readers in an RCU read-side critical
+ * section never dereference a freed session.
+ */
+static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
+{
+	struct nfs4_cb_conn conn;
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd4_session *ses = NULL;
+	struct nfsd4_conn *c;
+	int err;
+
+	trace_nfsd_cb_bc_update(clp, cb);
+
+	/*
+	 * This is either an update, or the client dying; in either case,
+	 * kill the old client:
+	 */
+	if (clp->cl_cb_client) {
+		trace_nfsd_cb_bc_shutdown(clp, cb);
+		rpc_shutdown_client(clp->cl_cb_client);
+		clp->cl_cb_client = NULL;
+		put_cred(clp->cl_cb_cred);
+		clp->cl_cb_cred = NULL;
+	}
+	if (clp->cl_cb_conn.cb_xprt) {
+		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
+		clp->cl_cb_conn.cb_xprt = NULL;
+	}
+	if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
+		return;
+
+	spin_lock(&clp->cl_lock);
+	/*
+	 * Only serialized callback code is allowed to clear these
+	 * flags; main nfsd code can only set them:
+	 */
+	WARN_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
+	clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
+
+	memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
+	c = __nfsd4_find_backchannel(clp);
+	if (c) {
+		svc_xprt_get(c->cn_xprt);
+		conn.cb_xprt = c->cn_xprt;
+		ses = c->cn_session;
+	}
+	spin_unlock(&clp->cl_lock);
+
+	err = setup_callback_client(clp, &conn, ses);
+	if (err) {
+		nfsd4_mark_cb_down(clp);
+		if (c)
+			svc_xprt_put(c->cn_xprt);
+		rcu_assign_pointer(clp->cl_cb_session, ses);
+		return;
+	}
+}
+
+static void
+nfsd4_run_cb_work(struct work_struct *work)
+{
+	struct nfsd4_callback *cb =
+		container_of(work, struct nfsd4_callback, cb_work);
+	struct nfs4_client *clp = cb->cb_clp;
+	struct rpc_clnt *clnt;
+	int flags, ret;
+
+	trace_nfsd_cb_start(clp);
+
+	if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
+		nfsd4_process_cb_update(cb);
+
+	clnt = clp->cl_cb_client;
+	if (!clnt || clp->cl_state == NFSD4_COURTESY) {
+		/*
+		 * Callback channel broken, client killed or
+		 * nfs4_client in courtesy state; give up.
+		 */
+		nfsd41_destroy_cb(cb);
+		return;
+	}
+
+	/*
+	 * Don't send probe messages for 4.1 or later.
+	 */
+	if (!cb->cb_ops && clp->cl_minorversion) {
+		nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
+		nfsd41_destroy_cb(cb);
+		return;
+	}
+
+	if (!test_and_clear_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags)) {
+		if (cb->cb_ops && cb->cb_ops->prepare)
+			if (!cb->cb_ops->prepare(cb)) {
+				nfsd41_destroy_cb(cb);
+				return;
+			}
+	}
+
+	cb->cb_msg.rpc_cred = clp->cl_cb_cred;
+	flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
+	ret = rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
+			     cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
+	if (ret != 0) {
+		set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags);
+		nfsd4_queue_cb(cb);
+	}
+}
+
+void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
+		const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
+{
+	cb->cb_clp = clp;
+	cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
+	cb->cb_msg.rpc_argp = cb;
+	cb->cb_msg.rpc_resp = cb;
+	cb->cb_flags = 0;
+	cb->cb_ops = ops;
+	INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
+	cb->cb_status = 0;
+	cb->cb_held_slot = -1;
+	cb->cb_nr_referring_call_list = 0;
+	INIT_LIST_HEAD(&cb->cb_referring_call_list);
+}
+
+/**
+ * nfsd4_run_cb - queue up a callback job to run
+ * @cb: callback to queue
+ *
+ * Kick off a callback to do its thing. Returns false if it was already
+ * on a queue, true otherwise.
+ */
+bool nfsd4_run_cb(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	const struct nfsd4_callback_ops *ops = cb->cb_ops;
+	u32 minorversion = clp->cl_minorversion;
+	bool queued;
+
+	nfsd41_cb_inflight_begin(clp);
+	queued = nfsd4_queue_cb(cb);
+	if (queued) {
+		if (ops) {
+			nfsd_stats_cb_op_inc(nn, ops->opcode);
+			/*
+			 * Minorversion > 0 callbacks prepend a CB_SEQUENCE op
+			 * (see encode_cb_sequence4args()); count it like the
+			 * forechannel counts SEQUENCE, so it isn't perpetually
+			 * reported as zero.  CB_NULL probes (ops == NULL) carry
+			 * no CB_SEQUENCE -- and on 4.1+ they are dropped without
+			 * sending any RPC (see nfsd4_run_cb_work()) -- so they
+			 * must not be counted here.
+			 */
+			if (minorversion > 0)
+				nfsd_stats_cb_op_inc(nn, OP_CB_SEQUENCE);
+		}
+	} else {
+		nfsd41_cb_inflight_end(clp);
+	}
+	return queued;
+}
+
+/**
+ * nfsd_net_cb_shutdown - release per-netns callback RPC program resources
+ * @nn: NFS server network namespace
+ *
+ * Frees resources allocated by nfsd_net_cb_init().
+ */
+void nfsd_net_cb_shutdown(struct nfsd_net *nn)
+{
+	struct nfsd_net_cb *cb = nn->nfsd_cb;
+
+	if (cb) {
+		kfree(cb->version4.counts);
+		kfree(cb);
+		nn->nfsd_cb = NULL;
+	}
+}
+
+/**
+ * nfsd_net_cb_init - initialize per-netns callback RPC program
+ * @nn: NFS server network namespace
+ *
+ * Sets up the callback RPC program, version table, procedure
+ * counts, and statistics structure for @nn. Caller must release
+ * these resources using nfsd_net_cb_shutdown().
+ *
+ * Return: 0 on success, or -ENOMEM if allocation fails.
+ */
+int nfsd_net_cb_init(struct nfsd_net *nn)
+{
+	struct nfsd_net_cb *cb;
+
+	cb = kzalloc_obj(*cb);
+	if (!cb)
+		return -ENOMEM;
+
+	cb->version4.counts = kzalloc_objs(unsigned int,
+			ARRAY_SIZE(nfs4_cb_procedures));
+	if (!cb->version4.counts) {
+		kfree(cb);
+		return -ENOMEM;
+	}
+	/*
+	 * Note on the callback rpc program version number: despite language
+	 * in rfc 5661 section 18.36.3 requiring servers to use 4 in this
+	 * field, the official xdr descriptions for both 4.0 and 4.1 specify
+	 * version 1, and in practice that appears to be what implementations
+	 * use. The section 18.36.3 language is expected to be fixed in an
+	 * erratum.
+	 */
+	cb->version4.number = NFS4_CB_VERSION;
+	cb->version4.nrprocs = ARRAY_SIZE(nfs4_cb_procedures);
+	cb->version4.procs = nfs4_cb_procedures;
+	cb->versions[NFS4_CB_VERSION] = &cb->version4;
+
+	cb->program.name = "nfs4_cb";
+	cb->program.number = NFS4_CB_PROGRAM;
+	cb->program.nrvers = ARRAY_SIZE(cb->versions);
+	cb->program.version = &cb->versions[0];
+	cb->program.pipe_dir_name = "nfsd4_cb";
+	cb->program.stats = &cb->stat;
+	cb->stat.program = &cb->program;
+
+	nn->nfsd_cb = cb;
+
+	return 0;
+}
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
new file mode 100644
index 000000000..e9faf8b78
--- /dev/null
+++ b/fs/nfsd/nfs4idmap.c
@@ -0,0 +1,733 @@
+/*
+ *  Mapping of UID/GIDs to name and vice versa.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of
+ *  Michigan.  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <net/net_namespace.h>
+#include "auth.h"
+#include "idmap.h"
+#include "nfsd.h"
+#include "netns.h"
+#include "vfs.h"
+
+/*
+ * Turn off idmapping when using AUTH_SYS.
+ */
+static bool nfs4_disable_idmapping = true;
+module_param(nfs4_disable_idmapping, bool, 0644);
+MODULE_PARM_DESC(nfs4_disable_idmapping,
+		"Turn off server's NFSv4 idmapping when using 'sec=sys'");
+
+/*
+ * Cache entry
+ */
+
+/*
+ * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
+ * that.
+ */
+
+struct ent {
+	struct cache_head h;
+	int               type;		       /* User / Group */
+	u32               id;
+	char              name[IDMAP_NAMESZ];
+	char              authname[IDMAP_NAMESZ];
+	struct rcu_head	  rcu_head;
+};
+
+/* Common entry handling */
+
+#define ENT_HASHBITS          8
+#define ENT_HASHMAX           (1 << ENT_HASHBITS)
+
+static void
+ent_init(struct cache_head *cnew, struct cache_head *citm)
+{
+	struct ent *new = container_of(cnew, struct ent, h);
+	struct ent *itm = container_of(citm, struct ent, h);
+
+	new->id = itm->id;
+	new->type = itm->type;
+
+	strscpy(new->name, itm->name, sizeof(new->name));
+	strscpy(new->authname, itm->authname, sizeof(new->authname));
+}
+
+static void
+ent_put(struct kref *ref)
+{
+	struct ent *map = container_of(ref, struct ent, h.ref);
+	kfree_rcu(map, rcu_head);
+}
+
+static struct cache_head *
+ent_alloc(void)
+{
+	struct ent *e = kmalloc_obj(*e);
+	if (e)
+		return &e->h;
+	else
+		return NULL;
+}
+
+/*
+ * ID -> Name cache
+ */
+
+static uint32_t
+idtoname_hash(struct ent *ent)
+{
+	uint32_t hash;
+
+	hash = hash_str(ent->authname, ENT_HASHBITS);
+	hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
+
+	/* Flip LSB for user/group */
+	if (ent->type == IDMAP_TYPE_GROUP)
+		hash ^= 1;
+
+	return hash;
+}
+
+static int
+idtoname_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_upcall_warn(cd, h);
+}
+
+static void
+idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
+    int *blen)
+{
+ 	struct ent *ent = container_of(ch, struct ent, h);
+	char idstr[11];
+
+	qword_add(bpp, blen, ent->authname);
+	snprintf(idstr, sizeof(idstr), "%u", ent->id);
+	qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
+	qword_add(bpp, blen, idstr);
+
+	(*bpp)[-1] = '\n';
+}
+
+static int
+idtoname_match(struct cache_head *ca, struct cache_head *cb)
+{
+	struct ent *a = container_of(ca, struct ent, h);
+	struct ent *b = container_of(cb, struct ent, h);
+
+	return (a->id == b->id && a->type == b->type &&
+	    strcmp(a->authname, b->authname) == 0);
+}
+
+static int
+idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
+{
+	struct ent *ent;
+
+	if (h == NULL) {
+		seq_puts(m, "#domain type id [name]\n");
+		return 0;
+	}
+	ent = container_of(h, struct ent, h);
+	seq_printf(m, "%s %s %u", ent->authname,
+			ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
+			ent->id);
+	if (test_bit(CACHE_VALID, &h->flags))
+		seq_printf(m, " %s", ent->name);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static void
+warn_no_idmapd(struct cache_detail *detail, int has_died)
+{
+	printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
+			has_died ? "died" : "not been started");
+}
+
+
+static int         idtoname_parse(struct cache_detail *, char *, int);
+static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
+static struct ent *idtoname_update(struct cache_detail *, struct ent *,
+				   struct ent *);
+
+static const struct cache_detail idtoname_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= ENT_HASHMAX,
+	.name		= "nfs4.idtoname",
+	.cache_put	= ent_put,
+	.cache_upcall	= idtoname_upcall,
+	.cache_request	= idtoname_request,
+	.cache_parse	= idtoname_parse,
+	.cache_show	= idtoname_show,
+	.warn_no_listener = warn_no_idmapd,
+	.match		= idtoname_match,
+	.init		= ent_init,
+	.update		= ent_init,
+	.alloc		= ent_alloc,
+};
+
+static int
+idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
+{
+	struct ent ent, *res;
+	char *buf1, *bp;
+	int len;
+	int error = -EINVAL;
+
+	if (buf[buflen - 1] != '\n')
+		return (-EINVAL);
+	buf[buflen - 1]= '\0';
+
+	buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (buf1 == NULL)
+		return (-ENOMEM);
+
+	memset(&ent, 0, sizeof(ent));
+
+	/* Authentication name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.authname, buf1, sizeof(ent.authname));
+
+	/* Type */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.type = strcmp(buf1, "user") == 0 ?
+		IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
+
+	/* ID */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.id = simple_strtoul(buf1, &bp, 10);
+	if (bp == buf1)
+		goto out;
+
+	/* expiry */
+	error = get_expiry(&buf, &ent.h.expiry_time);
+	if (error)
+		goto out;
+
+	error = -ENOMEM;
+	res = idtoname_lookup(cd, &ent);
+	if (!res)
+		goto out;
+
+	/* Name */
+	error = -EINVAL;
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len < 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	if (len == 0)
+		set_bit(CACHE_NEGATIVE, &ent.h.flags);
+	else
+		memcpy(ent.name, buf1, sizeof(ent.name));
+	error = -ENOMEM;
+	res = idtoname_update(cd, &ent, res);
+	if (res == NULL)
+		goto out;
+
+	cache_put(&res->h, cd);
+	error = 0;
+out:
+	kfree(buf1);
+	return error;
+}
+
+static struct ent *
+idtoname_lookup(struct cache_detail *cd, struct ent *item)
+{
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							idtoname_hash(item));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+static struct ent *
+idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
+{
+	struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
+						    idtoname_hash(new));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+
+/*
+ * Name -> ID cache
+ */
+
+static inline int
+nametoid_hash(struct ent *ent)
+{
+	return hash_str(ent->name, ENT_HASHBITS);
+}
+
+static int
+nametoid_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_upcall_warn(cd, h);
+}
+
+static void
+nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
+    int *blen)
+{
+ 	struct ent *ent = container_of(ch, struct ent, h);
+
+	qword_add(bpp, blen, ent->authname);
+	qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
+	qword_add(bpp, blen, ent->name);
+
+	(*bpp)[-1] = '\n';
+}
+
+static int
+nametoid_match(struct cache_head *ca, struct cache_head *cb)
+{
+	struct ent *a = container_of(ca, struct ent, h);
+	struct ent *b = container_of(cb, struct ent, h);
+
+	return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
+	    strcmp(a->authname, b->authname) == 0);
+}
+
+static int
+nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
+{
+	struct ent *ent;
+
+	if (h == NULL) {
+		seq_puts(m, "#domain type name [id]\n");
+		return 0;
+	}
+	ent = container_of(h, struct ent, h);
+	seq_printf(m, "%s %s %s", ent->authname,
+			ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
+			ent->name);
+	if (test_bit(CACHE_VALID, &h->flags))
+		seq_printf(m, " %u", ent->id);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
+static struct ent *nametoid_update(struct cache_detail *, struct ent *,
+				   struct ent *);
+static int         nametoid_parse(struct cache_detail *, char *, int);
+
+static const struct cache_detail nametoid_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= ENT_HASHMAX,
+	.name		= "nfs4.nametoid",
+	.cache_put	= ent_put,
+	.cache_upcall	= nametoid_upcall,
+	.cache_request	= nametoid_request,
+	.cache_parse	= nametoid_parse,
+	.cache_show	= nametoid_show,
+	.warn_no_listener = warn_no_idmapd,
+	.match		= nametoid_match,
+	.init		= ent_init,
+	.update		= ent_init,
+	.alloc		= ent_alloc,
+};
+
+static int
+nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
+{
+	struct ent ent, *res;
+	char *buf1;
+	int len, error = -EINVAL;
+
+	if (buf[buflen - 1] != '\n')
+		return (-EINVAL);
+	buf[buflen - 1]= '\0';
+
+	buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (buf1 == NULL)
+		return (-ENOMEM);
+
+	memset(&ent, 0, sizeof(ent));
+
+	/* Authentication name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.authname, buf1, sizeof(ent.authname));
+
+	/* Type */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.type = strcmp(buf1, "user") == 0 ?
+		IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
+
+	/* Name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.name, buf1, sizeof(ent.name));
+
+	/* expiry */
+	error = get_expiry(&buf, &ent.h.expiry_time);
+	if (error)
+		goto out;
+
+	/* ID */
+	error = get_int(&buf, &ent.id);
+	if (error == -EINVAL)
+		goto out;
+	if (error == -ENOENT)
+		set_bit(CACHE_NEGATIVE, &ent.h.flags);
+
+	error = -ENOMEM;
+	res = nametoid_lookup(cd, &ent);
+	if (res == NULL)
+		goto out;
+	res = nametoid_update(cd, &ent, res);
+	if (res == NULL)
+		goto out;
+
+	cache_put(&res->h, cd);
+	error = 0;
+out:
+	kfree(buf1);
+	return (error);
+}
+
+
+static struct ent *
+nametoid_lookup(struct cache_detail *cd, struct ent *item)
+{
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							nametoid_hash(item));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+static struct ent *
+nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
+{
+	struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
+						    nametoid_hash(new));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+/*
+ * Exported API
+ */
+
+int
+nfsd_idmap_init(struct net *net)
+{
+	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
+	if (IS_ERR(nn->idtoname_cache))
+		return PTR_ERR(nn->idtoname_cache);
+	rv = cache_register_net(nn->idtoname_cache, net);
+	if (rv)
+		goto destroy_idtoname_cache;
+	nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
+	if (IS_ERR(nn->nametoid_cache)) {
+		rv = PTR_ERR(nn->nametoid_cache);
+		goto unregister_idtoname_cache;
+	}
+	rv = cache_register_net(nn->nametoid_cache, net);
+	if (rv)
+		goto destroy_nametoid_cache;
+	return 0;
+
+destroy_nametoid_cache:
+	cache_destroy_net(nn->nametoid_cache, net);
+unregister_idtoname_cache:
+	cache_unregister_net(nn->idtoname_cache, net);
+destroy_idtoname_cache:
+	cache_destroy_net(nn->idtoname_cache, net);
+	return rv;
+}
+
+void
+nfsd_idmap_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_unregister_net(nn->idtoname_cache, net);
+	cache_unregister_net(nn->nametoid_cache, net);
+	cache_destroy_net(nn->idtoname_cache, net);
+	cache_destroy_net(nn->nametoid_cache, net);
+}
+
+static int
+idmap_lookup(struct svc_rqst *rqstp,
+		struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
+		struct ent *key, struct cache_detail *detail, struct ent **item)
+{
+	int ret;
+
+	*item = lookup_fn(detail, key);
+	if (!*item)
+		return -ENOMEM;
+ retry:
+	ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
+
+	if (ret == -ETIMEDOUT) {
+		struct ent *prev_item = *item;
+		*item = lookup_fn(detail, key);
+		if (*item != prev_item)
+			goto retry;
+		cache_put(&(*item)->h, detail);
+	}
+	return ret;
+}
+
+static char *
+rqst_authname(struct svc_rqst *rqstp)
+{
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
+	return clp->name;
+}
+
+static __be32
+idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
+		u32 *id)
+{
+	struct ent *item, key = {
+		.type = type,
+	};
+	int ret;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (namelen + 1 > sizeof(key.name))
+		return nfserr_badowner;
+	memcpy(key.name, name, namelen);
+	key.name[namelen] = '\0';
+	strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
+	ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
+	if (ret == -ENOENT)
+		return nfserr_badowner;
+	if (ret)
+		return nfserrno(ret);
+	*id = item->id;
+	cache_put(&item->h, nn->nametoid_cache);
+	return 0;
+}
+
+static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
+{
+	char buf[11];
+	int len;
+	__be32 *p;
+
+	len = sprintf(buf, "%u", id);
+	p = xdr_reserve_space(xdr, len + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, buf, len);
+	return 0;
+}
+
+static __be32 idmap_id_to_name(struct xdr_stream *xdr,
+			       struct svc_rqst *rqstp, int type, u32 id)
+{
+	struct ent *item, key = {
+		.id = id,
+		.type = type,
+	};
+	__be32 status = nfs_ok;
+	__be32 *p;
+	int ret;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
+	ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
+	if (ret == -ENOENT)
+		return encode_ascii_id(xdr, id);
+	if (ret)
+		return nfserrno(ret);
+	ret = strlen(item->name);
+	WARN_ON_ONCE(ret > IDMAP_NAMESZ);
+
+	p = xdr_reserve_space(xdr, ret + 4);
+	if (unlikely(!p)) {
+		status = nfserr_resource;
+		goto out_put;
+	}
+	xdr_encode_opaque(p, item->name, ret);
+out_put:
+	cache_put(&item->h, nn->idtoname_cache);
+	return status;
+}
+
+static bool
+numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
+{
+	int ret;
+	char buf[11];
+
+	if (namelen + 1 > sizeof(buf))
+		/* too long to represent a 32-bit id: */
+		return false;
+	/* Just to make sure it's null-terminated: */
+	memcpy(buf, name, namelen);
+	buf[namelen] = '\0';
+	ret = kstrtouint(buf, 10, id);
+	return ret == 0;
+}
+
+static __be32
+do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
+{
+	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
+		if (numeric_name_to_id(rqstp, type, name, namelen, id))
+			return 0;
+		/*
+		 * otherwise, fall through and try idmapping, for
+		 * backwards compatibility with clients sending names:
+		 */
+	return idmap_name_to_id(rqstp, type, name, namelen, id);
+}
+
+static __be32 encode_name_from_id(struct xdr_stream *xdr,
+				  struct svc_rqst *rqstp, int type, u32 id)
+{
+	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
+		return encode_ascii_id(xdr, id);
+	return idmap_id_to_name(xdr, rqstp, type, id);
+}
+
+/**
+ * nfsd_map_name_to_uid - Map user@domain to local UID
+ * @rqstp: RPC execution context
+ * @name: user@domain name to be mapped
+ * @namelen: length of name, in bytes
+ * @uid: OUT: mapped local UID value
+ *
+ * Returns nfs_ok on success or an NFSv4 status code on failure.
+ */
+__be32 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name,
+			    size_t namelen, kuid_t *uid)
+{
+	__be32 status;
+	u32 id = -1;
+
+	/*
+	 * The idmap lookup below triggers an upcall that invokes
+	 * cache_check(). RQ_USEDEFERRAL must be clear to prevent
+	 * cache_check() from setting RQ_DROPME via svc_defer().
+	 * NFSv4 servers are not permitted to drop requests. Also
+	 * RQ_DROPME will force NFSv4.1 session slot processing to
+	 * be skipped.
+	 */
+	WARN_ON_ONCE(test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags));
+
+	if (name == NULL || namelen == 0)
+		return nfserr_inval;
+
+	status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
+	if (status)
+		return status;
+	*uid = make_kuid(nfsd_user_namespace(rqstp), id);
+	if (!uid_valid(*uid))
+		status = nfserr_badowner;
+	return status;
+}
+
+/**
+ * nfsd_map_name_to_gid - Map user@domain to local GID
+ * @rqstp: RPC execution context
+ * @name: user@domain name to be mapped
+ * @namelen: length of name, in bytes
+ * @gid: OUT: mapped local GID value
+ *
+ * Returns nfs_ok on success or an NFSv4 status code on failure.
+ */
+__be32 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name,
+			    size_t namelen, kgid_t *gid)
+{
+	__be32 status;
+	u32 id = -1;
+
+	/*
+	 * The idmap lookup below triggers an upcall that invokes
+	 * cache_check(). RQ_USEDEFERRAL must be clear to prevent
+	 * cache_check() from setting RQ_DROPME via svc_defer().
+	 * NFSv4 servers are not permitted to drop requests. Also
+	 * RQ_DROPME will force NFSv4.1 session slot processing to
+	 * be skipped.
+	 */
+	WARN_ON_ONCE(test_bit(RQ_USEDEFERRAL, &rqstp->rq_flags));
+
+	if (name == NULL || namelen == 0)
+		return nfserr_inval;
+
+	status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
+	if (status)
+		return status;
+	*gid = make_kgid(nfsd_user_namespace(rqstp), id);
+	if (!gid_valid(*gid))
+		status = nfserr_badowner;
+	return status;
+}
+
+__be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			 kuid_t uid)
+{
+	u32 id = from_kuid_munged(nfsd_user_namespace(rqstp), uid);
+	return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
+}
+
+__be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			  kgid_t gid)
+{
+	u32 id = from_kgid_munged(nfsd_user_namespace(rqstp), gid);
+	return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
+}
diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
new file mode 100644
index 000000000..22bcb6d09
--- /dev/null
+++ b/fs/nfsd/nfs4layouts.c
@@ -0,0 +1,967 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ */
+#include <linux/exportfs_block.h>
+#include <linux/kmod.h>
+#include <linux/file.h>
+#include <linux/jhash.h>
+#include <linux/sched.h>
+#include <linux/sunrpc/addr.h>
+
+#include "pnfs.h"
+#include "netns.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PNFS
+
+struct nfs4_layout {
+	struct list_head		lo_perstate;
+	struct nfs4_layout_stateid	*lo_state;
+	struct nfsd4_layout_seg		lo_seg;
+};
+
+static struct kmem_cache *nfs4_layout_cache;
+static struct kmem_cache *nfs4_layout_stateid_cache;
+
+static const struct nfsd4_callback_ops nfsd4_cb_layout_ops;
+static const struct lease_manager_operations nfsd4_layouts_lm_ops;
+
+static void nfsd4_layout_fence_worker(struct work_struct *work);
+
+const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
+#ifdef CONFIG_NFSD_FLEXFILELAYOUT
+	[LAYOUT_FLEX_FILES]	= &ff_layout_ops,
+#endif
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+	[LAYOUT_BLOCK_VOLUME]	= &bl_layout_ops,
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	[LAYOUT_SCSI]		= &scsi_layout_ops,
+#endif
+};
+
+/* pNFS device ID to export fsid mapping */
+#define DEVID_HASH_BITS	8
+#define DEVID_HASH_SIZE	(1 << DEVID_HASH_BITS)
+#define DEVID_HASH_MASK	(DEVID_HASH_SIZE - 1)
+static u64 nfsd_devid_seq = 1;
+static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
+static DEFINE_SPINLOCK(nfsd_devid_lock);
+
+static inline u32 devid_hashfn(u64 idx)
+{
+	return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
+}
+
+static void
+nfsd4_alloc_devid_map(const struct svc_fh *fhp)
+{
+	const struct knfsd_fh *fh = &fhp->fh_handle;
+	size_t fsid_len = key_len(fh->fh_fsid_type);
+	struct nfsd4_deviceid_map *map, *old;
+	int i;
+
+	map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
+	if (!map)
+		return;
+
+	map->fsid_type = fh->fh_fsid_type;
+	memcpy(&map->fsid, fh_fsid(fh), fsid_len);
+
+	spin_lock(&nfsd_devid_lock);
+	if (fhp->fh_export->ex_devid_map)
+		goto out_unlock;
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++) {
+		list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
+			if (old->fsid_type != fh->fh_fsid_type)
+				continue;
+			if (memcmp(old->fsid, fh_fsid(fh),
+					key_len(old->fsid_type)))
+				continue;
+
+			fhp->fh_export->ex_devid_map = old;
+			goto out_unlock;
+		}
+	}
+
+	map->idx = nfsd_devid_seq++;
+	list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
+	fhp->fh_export->ex_devid_map = map;
+	map = NULL;
+
+out_unlock:
+	spin_unlock(&nfsd_devid_lock);
+	kfree(map);
+}
+
+struct nfsd4_deviceid_map *
+nfsd4_find_devid_map(int idx)
+{
+	struct nfsd4_deviceid_map *map, *ret = NULL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
+		if (map->idx == idx)
+			ret = map;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int
+nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
+		u32 device_generation)
+{
+	if (!fhp->fh_export->ex_devid_map) {
+		nfsd4_alloc_devid_map(fhp);
+		if (!fhp->fh_export->ex_devid_map)
+			return -ENOMEM;
+	}
+
+	id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
+	id->generation = device_generation;
+	return 0;
+}
+
+void nfsd4_setup_layout_type(struct svc_export *exp)
+{
+	struct super_block *sb = exp->ex_path.mnt->mnt_sb;
+	expfs_block_layouts_t block_supported = exportfs_layouts_supported(sb);
+
+	if (IS_ENABLED(CONFIG_NFSD_FLEXFILELAYOUT))
+		exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES;
+	if (IS_ENABLED(CONFIG_NFSD_BLOCKLAYOUT) &&
+	    (block_supported & EXPFS_BLOCK_IN_BAND_ID))
+		exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME;
+	if (IS_ENABLED(CONFIG_NFSD_SCSILAYOUT) &&
+	    (block_supported & EXPFS_BLOCK_OUT_OF_BAND_ID))
+		exp->ex_layout_types |= 1 << LAYOUT_SCSI;
+}
+
+void nfsd4_close_layout(struct nfs4_layout_stateid *ls)
+{
+	struct nfsd_file *fl;
+
+	spin_lock(&ls->ls_stid.sc_file->fi_lock);
+	fl = ls->ls_file;
+	ls->ls_file = NULL;
+	spin_unlock(&ls->ls_stid.sc_file->fi_lock);
+
+	if (fl) {
+		if (!nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
+			kernel_setlease(fl->nf_file, F_UNLCK, NULL,
+					(void **)&ls);
+		nfsd_file_put(fl);
+	}
+}
+
+static void
+nfsd4_free_layout_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_layout_stateid *ls = layoutstateid(stid);
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+
+	trace_nfsd_layoutstate_free(&ls->ls_stid.sc_stateid);
+
+	spin_lock(&ls->ls_lock);
+	if (delayed_work_pending(&ls->ls_fence_work)) {
+		spin_unlock(&ls->ls_lock);
+		cancel_delayed_work_sync(&ls->ls_fence_work);
+	} else
+		spin_unlock(&ls->ls_lock);
+
+	spin_lock(&clp->cl_lock);
+	list_del_init(&ls->ls_perclnt);
+	spin_unlock(&clp->cl_lock);
+
+	spin_lock(&fp->fi_lock);
+	list_del_init(&ls->ls_perfile);
+	spin_unlock(&fp->fi_lock);
+
+	nfsd4_close_layout(ls);
+
+	if (ls->ls_recalled)
+		atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
+
+	kmem_cache_free(nfs4_layout_stateid_cache, ls);
+}
+
+static int
+nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
+{
+	struct file_lease *fl;
+	int status;
+
+	if (nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
+		return 0;
+
+	fl = locks_alloc_lease();
+	if (!fl)
+		return -ENOMEM;
+	locks_init_lease(fl);
+	fl->fl_lmops = &nfsd4_layouts_lm_ops;
+	fl->c.flc_flags = FL_LAYOUT;
+	fl->c.flc_type = F_RDLCK;
+	fl->c.flc_owner = ls;
+	fl->c.flc_pid = current->tgid;
+	fl->c.flc_file = ls->ls_file->nf_file;
+
+	status = kernel_setlease(fl->c.flc_file, fl->c.flc_type, &fl, NULL);
+	if (status) {
+		locks_free_lease(fl);
+		return status;
+	}
+	BUG_ON(fl != NULL);
+	return 0;
+}
+
+static struct nfs4_layout_stateid *
+nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
+		struct nfs4_stid *parent, u32 layout_type)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_file *fp = parent->sc_file;
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_stid *stp;
+
+	stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache,
+					nfsd4_free_layout_stateid);
+	if (!stp)
+		return NULL;
+
+	get_nfs4_file(fp);
+	stp->sc_file = fp;
+	if (parent->sc_export)
+		stp->sc_export = exp_get(parent->sc_export);
+
+	ls = layoutstateid(stp);
+	INIT_LIST_HEAD(&ls->ls_perclnt);
+	INIT_LIST_HEAD(&ls->ls_perfile);
+	spin_lock_init(&ls->ls_lock);
+	INIT_LIST_HEAD(&ls->ls_layouts);
+	mutex_init(&ls->ls_mutex);
+	ls->ls_layout_type = layout_type;
+	nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
+			NFSPROC4_CLNT_CB_LAYOUT);
+
+	if (parent->sc_type == SC_TYPE_DELEG) {
+		rcu_read_lock();
+		ls->ls_file = nfsd_file_get(rcu_dereference(fp->fi_deleg_file));
+		rcu_read_unlock();
+	} else {
+		ls->ls_file = find_any_file(fp);
+	}
+
+	if (!ls->ls_file) {
+		nfs4_put_stid(stp);
+		return NULL;
+	}
+
+	ls->ls_fenced = false;
+	ls->ls_fence_inflight = false;
+	ls->ls_fence_delay = 0;
+	INIT_DELAYED_WORK(&ls->ls_fence_work, nfsd4_layout_fence_worker);
+
+	if (nfsd4_layout_setlease(ls)) {
+		nfs4_put_stid(stp);
+		return NULL;
+	}
+
+	spin_lock(&clp->cl_lock);
+	stp->sc_type = SC_TYPE_LAYOUT;
+	list_add(&ls->ls_perclnt, &clp->cl_lo_states);
+	spin_unlock(&clp->cl_lock);
+
+	spin_lock(&fp->fi_lock);
+	list_add(&ls->ls_perfile, &fp->fi_lo_states);
+	spin_unlock(&fp->fi_lock);
+
+	trace_nfsd_layoutstate_alloc(&ls->ls_stid.sc_stateid);
+	return ls;
+}
+
+__be32
+nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, stateid_t *stateid,
+		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_stid *stid;
+	unsigned short typemask = SC_TYPE_LAYOUT;
+	__be32 status;
+
+	if (create)
+		typemask |= (SC_TYPE_OPEN | SC_TYPE_LOCK | SC_TYPE_DELEG);
+
+	status = nfsd4_lookup_stateid(cstate, stateid, typemask, 0, &stid,
+			net_generic(SVC_NET(rqstp), nfsd_net_id));
+	if (status)
+		goto out;
+
+	if (!fh_match(&cstate->current_fh.fh_handle,
+		      &stid->sc_file->fi_fhandle)) {
+		status = nfserr_bad_stateid;
+		goto out_put_stid;
+	}
+
+	if (stid->sc_type != SC_TYPE_LAYOUT) {
+		ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
+		nfs4_put_stid(stid);
+
+		status = nfserr_jukebox;
+		if (!ls)
+			goto out;
+		mutex_lock(&ls->ls_mutex);
+	} else {
+		ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
+
+		status = nfserr_bad_stateid;
+		mutex_lock(&ls->ls_mutex);
+		if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
+			goto out_unlock_stid;
+		if (layout_type != ls->ls_layout_type)
+			goto out_unlock_stid;
+	}
+
+	*lsp = ls;
+	return 0;
+
+out_unlock_stid:
+	mutex_unlock(&ls->ls_mutex);
+out_put_stid:
+	nfs4_put_stid(stid);
+out:
+	return status;
+}
+
+static void
+nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
+{
+	spin_lock(&ls->ls_lock);
+	if (ls->ls_recalled)
+		goto out_unlock;
+
+	if (list_empty(&ls->ls_layouts))
+		goto out_unlock;
+
+	ls->ls_recalled = true;
+	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
+	trace_nfsd_layout_recall(&ls->ls_stid.sc_stateid);
+
+	if (!test_and_set_bit(NFSD4_CALLBACK_RUNNING, &ls->ls_recall.cb_flags)) {
+		refcount_inc(&ls->ls_stid.sc_count);
+		nfsd4_run_cb(&ls->ls_recall);
+	}
+out_unlock:
+	spin_unlock(&ls->ls_lock);
+}
+
+static inline u64
+layout_end(struct nfsd4_layout_seg *seg)
+{
+	u64 end = seg->offset + seg->length;
+	return end >= seg->offset ? end : NFS4_MAX_UINT64;
+}
+
+static void
+layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
+{
+	if (end == NFS4_MAX_UINT64)
+		lo->length = NFS4_MAX_UINT64;
+	else
+		lo->length = end - lo->offset;
+}
+
+static bool
+layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
+{
+	if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
+		return false;
+	if (layout_end(&lo->lo_seg) <= s->offset)
+		return false;
+	if (layout_end(s) <= lo->lo_seg.offset)
+		return false;
+	return true;
+}
+
+static bool
+layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
+{
+	if (lo->iomode != new->iomode)
+		return false;
+	if (layout_end(new) < lo->offset)
+		return false;
+	if (layout_end(lo) < new->offset)
+		return false;
+
+	lo->offset = min(lo->offset, new->offset);
+	layout_update_len(lo, max(layout_end(lo), layout_end(new)));
+	return true;
+}
+
+static __be32
+nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
+{
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+	struct nfs4_layout_stateid *l, *n;
+	__be32 nfserr = nfs_ok;
+
+	assert_spin_locked(&fp->fi_lock);
+
+	list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
+		if (l != ls) {
+			nfsd4_recall_file_layout(l);
+			nfserr = nfserr_recallconflict;
+		}
+	}
+
+	return nfserr;
+}
+
+__be32
+nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
+{
+	struct nfsd4_layout_seg *seg = &lgp->lg_seg;
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+	struct nfs4_layout *lp, *new = NULL;
+	__be32 nfserr;
+
+	spin_lock(&fp->fi_lock);
+	nfserr = nfsd4_recall_conflict(ls);
+	if (nfserr)
+		goto out;
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
+		if (layouts_try_merge(&lp->lo_seg, seg))
+			goto done;
+	}
+	spin_unlock(&ls->ls_lock);
+	spin_unlock(&fp->fi_lock);
+
+	new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
+	if (!new)
+		return nfserr_jukebox;
+	memcpy(&new->lo_seg, seg, sizeof(new->lo_seg));
+	new->lo_state = ls;
+
+	spin_lock(&fp->fi_lock);
+	nfserr = nfsd4_recall_conflict(ls);
+	if (nfserr)
+		goto out;
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
+		if (layouts_try_merge(&lp->lo_seg, seg))
+			goto done;
+	}
+
+	refcount_inc(&ls->ls_stid.sc_count);
+	list_add_tail(&new->lo_perstate, &ls->ls_layouts);
+	new = NULL;
+done:
+	nfs4_inc_and_copy_stateid(&lgp->lg_sid, &ls->ls_stid);
+	spin_unlock(&ls->ls_lock);
+out:
+	spin_unlock(&fp->fi_lock);
+	if (new)
+		kmem_cache_free(nfs4_layout_cache, new);
+	return nfserr;
+}
+
+static void
+nfsd4_free_layouts(struct list_head *reaplist)
+{
+	while (!list_empty(reaplist)) {
+		struct nfs4_layout *lp = list_first_entry(reaplist,
+				struct nfs4_layout, lo_perstate);
+
+		list_del(&lp->lo_perstate);
+		nfs4_put_stid(&lp->lo_state->ls_stid);
+		kmem_cache_free(nfs4_layout_cache, lp);
+	}
+}
+
+static void
+nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
+		struct list_head *reaplist)
+{
+	struct nfsd4_layout_seg *lo = &lp->lo_seg;
+	u64 end = layout_end(lo);
+
+	if (seg->offset <= lo->offset) {
+		if (layout_end(seg) >= end) {
+			list_move_tail(&lp->lo_perstate, reaplist);
+			return;
+		}
+		lo->offset = layout_end(seg);
+	} else {
+		/* retain the whole layout segment on a split. */
+		if (layout_end(seg) < end) {
+			dprintk("%s: split not supported\n", __func__);
+			return;
+		}
+		end = seg->offset;
+	}
+
+	layout_update_len(lo, end);
+}
+
+__be32
+nfsd4_return_file_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_layout *lp, *n;
+	LIST_HEAD(reaplist);
+	__be32 nfserr;
+	int found = 0;
+
+	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
+						false, lrp->lr_layout_type,
+						&ls);
+	if (nfserr) {
+		trace_nfsd_layout_return_lookup_fail(&lrp->lr_sid);
+		return nfserr;
+	}
+
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
+		if (layouts_overlapping(lp, &lrp->lr_seg)) {
+			nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
+			found++;
+		}
+	}
+	if (!list_empty(&ls->ls_layouts)) {
+		if (found)
+			nfs4_inc_and_copy_stateid(&lrp->lr_sid, &ls->ls_stid);
+		lrp->lrs_present = true;
+	} else {
+		trace_nfsd_layoutstate_unhash(&ls->ls_stid.sc_stateid);
+		ls->ls_stid.sc_status |= SC_STATUS_CLOSED;
+		lrp->lrs_present = false;
+	}
+	spin_unlock(&ls->ls_lock);
+
+	mutex_unlock(&ls->ls_mutex);
+	nfs4_put_stid(&ls->ls_stid);
+	nfsd4_free_layouts(&reaplist);
+	return nfs_ok;
+}
+
+__be32
+nfsd4_return_client_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_layout *lp, *t;
+	LIST_HEAD(reaplist);
+
+	lrp->lrs_present = false;
+
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
+		if (ls->ls_layout_type != lrp->lr_layout_type)
+			continue;
+
+		if (lrp->lr_return_type == RETURN_FSID &&
+		    !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
+				   &cstate->current_fh.fh_handle))
+			continue;
+
+		spin_lock(&ls->ls_lock);
+		list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
+			if (lrp->lr_seg.iomode == IOMODE_ANY ||
+			    lrp->lr_seg.iomode == lp->lo_seg.iomode)
+				list_move_tail(&lp->lo_perstate, &reaplist);
+		}
+		spin_unlock(&ls->ls_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+
+	nfsd4_free_layouts(&reaplist);
+	return 0;
+}
+
+static void
+nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
+		struct list_head *reaplist)
+{
+	spin_lock(&ls->ls_lock);
+	list_splice_init(&ls->ls_layouts, reaplist);
+	spin_unlock(&ls->ls_lock);
+}
+
+void
+nfsd4_return_all_client_layouts(struct nfs4_client *clp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
+		nfsd4_return_all_layouts(ls, &reaplist);
+	spin_unlock(&clp->cl_lock);
+
+	nfsd4_free_layouts(&reaplist);
+}
+
+void
+nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&fp->fi_lock);
+	list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
+		if (ls->ls_stid.sc_client == clp)
+			nfsd4_return_all_layouts(ls, &reaplist);
+	}
+	spin_unlock(&fp->fi_lock);
+
+	nfsd4_free_layouts(&reaplist);
+}
+
+static void
+nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls, struct nfsd_file *file)
+{
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	char addr_str[INET6_ADDRSTRLEN];
+	static char const nfsd_recall_failed[] = "/sbin/nfsd-recall-failed";
+	static char *envp[] = {
+		"HOME=/",
+		"TERM=linux",
+		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+		NULL
+	};
+	char *argv[8];
+	int error;
+
+	rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
+
+	printk(KERN_WARNING
+		"nfsd: client %s failed to respond to layout recall. "
+		"  Fencing..\n", addr_str);
+
+	argv[0] = (char *)nfsd_recall_failed;
+	argv[1] = addr_str;
+	argv[2] = file->nf_file->f_path.mnt->mnt_sb->s_id;
+	argv[3] = NULL;
+
+	error = call_usermodehelper(nfsd_recall_failed, argv, envp,
+				    UMH_WAIT_PROC);
+	if (error) {
+		printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
+			addr_str, error);
+	}
+}
+
+static bool
+nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+
+	mutex_lock(&ls->ls_mutex);
+	nfs4_inc_and_copy_stateid(&ls->ls_recall_sid, &ls->ls_stid);
+	mutex_unlock(&ls->ls_mutex);
+	return true;
+}
+
+static int
+nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	struct nfsd_net *nn;
+	ktime_t now, cutoff;
+	const struct nfsd4_layout_ops *ops;
+	struct nfsd_file *fl;
+
+	trace_nfsd_cb_layout_done(&ls->ls_stid.sc_stateid, task);
+	switch (task->tk_status) {
+	case 0:
+	case -NFS4ERR_DELAY:
+		/*
+		 * Anything left? If not, then call it done. Note that we don't
+		 * take the spinlock since this is an optimization and nothing
+		 * should get added until the cb counter goes to zero.
+		 */
+		if (list_empty(&ls->ls_layouts))
+			return 1;
+
+		/* Poll the client until it's done with the layout */
+		now = ktime_get();
+		nn = net_generic(ls->ls_stid.sc_client->net, nfsd_net_id);
+
+		/* Client gets 2 lease periods to return it */
+		cutoff = ktime_add_ns(task->tk_start,
+					 (u64)nn->nfsd4_lease * NSEC_PER_SEC * 2);
+
+		if (ktime_before(now, cutoff)) {
+			rpc_delay(task, HZ/100); /* 10 mili-seconds */
+			return 0;
+		}
+		fallthrough;
+	default:
+		/*
+		 * Unknown error or non-responding client, we'll need to fence.
+		 */
+		trace_nfsd_layout_recall_fail(&ls->ls_stid.sc_stateid);
+		rcu_read_lock();
+		fl = nfsd_file_get(ls->ls_file);
+		rcu_read_unlock();
+		if (fl) {
+			ops = nfsd4_layout_ops[ls->ls_layout_type];
+			if (ops->fence_client)
+				ops->fence_client(ls, fl);
+			else
+				nfsd4_cb_layout_fail(ls, fl);
+			nfsd_file_put(fl);
+		}
+		return 1;
+	case -NFS4ERR_NOMATCHING_LAYOUT:
+		trace_nfsd_layout_recall_done(&ls->ls_stid.sc_stateid);
+		task->tk_status = 0;
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_layout_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	LIST_HEAD(reaplist);
+
+	trace_nfsd_layout_recall_release(&ls->ls_stid.sc_stateid);
+
+	nfsd4_return_all_layouts(ls, &reaplist);
+	nfsd4_free_layouts(&reaplist);
+	nfs4_put_stid(&ls->ls_stid);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
+	.prepare	= nfsd4_cb_layout_prepare,
+	.done		= nfsd4_cb_layout_done,
+	.release	= nfsd4_cb_layout_release,
+	.opcode		= OP_CB_LAYOUTRECALL,
+};
+
+static bool
+nfsd4_layout_lm_break(struct file_lease *fl)
+{
+	/*
+	 * Enforce break lease timeout to prevent NFSD
+	 * thread from hanging in __break_lease.
+	 */
+	nfsd4_recall_file_layout(fl->c.flc_owner);
+	return false;
+}
+
+static int
+nfsd4_layout_lm_change(struct file_lease *onlist, int arg,
+		struct list_head *dispose)
+{
+	BUG_ON(!(arg & F_UNLCK));
+	return lease_modify(onlist, arg, dispose);
+}
+
+/**
+ *  nfsd4_layout_lm_open_conflict - see if the given file points to an inode that has
+ *				    an existing open that would conflict with the
+ *				    desired lease.
+ * @filp:	file to check
+ * @arg:	type of lease that we're trying to acquire
+ *
+ * The kernel will call into this operation to determine whether there
+ * are conflicting opens that may prevent the layout from being granted.
+ * For nfsd, that check is done at a higher level, so this trivially
+ * returns 0.
+ */
+static int
+nfsd4_layout_lm_open_conflict(struct file *filp, int arg)
+{
+	return 0;
+}
+
+static void
+nfsd4_layout_fence_worker(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct nfs4_layout_stateid *ls = container_of(dwork,
+			struct nfs4_layout_stateid, ls_fence_work);
+	struct nfsd_file *nf;
+	struct block_device *bdev;
+	struct nfs4_client *clp;
+	struct nfsd_net *nn;
+
+	spin_lock(&ls->ls_lock);
+	if (list_empty(&ls->ls_layouts)) {
+		spin_unlock(&ls->ls_lock);
+dispose:
+		cancel_delayed_work(&ls->ls_fence_work);
+		/* unlock the lease so that tasks waiting on it can proceed */
+		nfsd4_close_layout(ls);
+
+		ls->ls_fenced = true;
+		spin_lock(&ls->ls_lock);
+		ls->ls_fence_inflight = false;
+		spin_unlock(&ls->ls_lock);
+		nfs4_put_stid(&ls->ls_stid);
+		return;
+	}
+	spin_unlock(&ls->ls_lock);
+
+	rcu_read_lock();
+	nf = nfsd_file_get(ls->ls_file);
+	rcu_read_unlock();
+	if (!nf)
+		goto dispose;
+
+	clp = ls->ls_stid.sc_client;
+	nn = net_generic(clp->net, nfsd_net_id);
+	bdev = nf->nf_file->f_path.mnt->mnt_sb->s_bdev;
+	if (nfsd4_layout_ops[ls->ls_layout_type]->fence_client(ls, nf)) {
+		/* fenced ok */
+		nfsd_file_put(nf);
+		pr_warn("%s: FENCED client[%pISpc] clid[%d] to device[%s]\n",
+			__func__, (struct sockaddr *)&clp->cl_addr,
+			clp->cl_clientid.cl_id - nn->clientid_base,
+			bdev->bd_disk->disk_name);
+		goto dispose;
+	}
+	/* fence failed */
+	nfsd_file_put(nf);
+
+	if (!clp->cl_fence_retry_warn) {
+		pr_warn("%s: FENCE failed client[%pISpc] clid[%d] device[%s]\n",
+			__func__, (struct sockaddr *)&clp->cl_addr,
+			clp->cl_clientid.cl_id - nn->clientid_base,
+			bdev->bd_disk->disk_name);
+		clp->cl_fence_retry_warn = true;
+	}
+	/*
+	 * The fence worker retries the fencing operation indefinitely to
+	 * prevent data corruption. The admin needs to take the following
+	 * actions to restore access to the file for other clients:
+	 *
+	 *  . shutdown or power off the client being fenced.
+	 *  . manually expire the client to release all its state on the server;
+	 *    echo 'expire' > /proc/fs/nfsd/clients/clid/ctl'.
+	 *
+	 *    Where:
+	 *
+	 *    clid: is the unique client identifier displayed in
+	 *          the warning message above.
+	 */
+	if (!ls->ls_fence_delay)
+		ls->ls_fence_delay = HZ;
+	else
+		ls->ls_fence_delay = min(ls->ls_fence_delay << 1,
+					 MAX_FENCE_DELAY);
+	mod_delayed_work(system_dfl_wq, &ls->ls_fence_work, ls->ls_fence_delay);
+}
+
+/**
+ * nfsd4_layout_lm_breaker_timedout - The layout recall has timed out.
+ * @fl: file to check
+ *
+ * If the layout type supports a fence operation, schedule a worker to
+ * fence the client from accessing the block device.
+ *
+ * This function runs under the protection of the spin_lock flc_lock.
+ * At this time, the file_lease associated with the layout stateid is
+ * on the flc_list. A reference count is incremented on the layout
+ * stateid to prevent it from being freed while the fence worker is
+ * executing. Once the fence worker finishes its operation, it releases
+ * this reference.
+ *
+ * The fence worker continues to run until either the client has been
+ * fenced or the layout becomes invalid. The layout can become invalid
+ * as a result of a LAYOUTRETURN or when the CB_LAYOUT recall callback
+ * has completed.
+ *
+ * Return true if the file_lease should be disposed of by the caller;
+ * otherwise, return false.
+ */
+static bool
+nfsd4_layout_lm_breaker_timedout(struct file_lease *fl)
+{
+	struct nfs4_layout_stateid *ls = fl->c.flc_owner;
+
+	if ((!nfsd4_layout_ops[ls->ls_layout_type]->fence_client) ||
+			ls->ls_fenced)
+		return true;
+	/*
+	 * Make sure layout has not been returned yet before
+	 * taking a reference count on the layout stateid. The
+	 * ls_fence_inflight flag is set together with the sc_count
+	 * increment under ls_lock so that a fence worker invocation
+	 * already in progress (which has cleared WORK_STRUCT_PENDING
+	 * but not yet reached dispose:) cannot be coalesced with a
+	 * fresh schedule that takes an extra unmatched reference.
+	 */
+	spin_lock(&ls->ls_lock);
+	if (ls->ls_fence_inflight) {
+		spin_unlock(&ls->ls_lock);
+		return false;
+	}
+	if (list_empty(&ls->ls_layouts) ||
+			!refcount_inc_not_zero(&ls->ls_stid.sc_count)) {
+		spin_unlock(&ls->ls_lock);
+		return true;
+	}
+	ls->ls_fence_inflight = true;
+	spin_unlock(&ls->ls_lock);
+
+	mod_delayed_work(system_dfl_wq, &ls->ls_fence_work, 0);
+	return false;
+}
+
+static const struct lease_manager_operations nfsd4_layouts_lm_ops = {
+	.lm_break		= nfsd4_layout_lm_break,
+	.lm_change		= nfsd4_layout_lm_change,
+	.lm_open_conflict	= nfsd4_layout_lm_open_conflict,
+	.lm_breaker_timedout	= nfsd4_layout_lm_breaker_timedout,
+};
+
+int
+nfsd4_init_pnfs(void)
+{
+	int i;
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nfsd_devid_hash[i]);
+
+	nfs4_layout_cache = KMEM_CACHE(nfs4_layout, 0);
+	if (!nfs4_layout_cache)
+		return -ENOMEM;
+
+	nfs4_layout_stateid_cache = KMEM_CACHE(nfs4_layout_stateid, 0);
+	if (!nfs4_layout_stateid_cache) {
+		kmem_cache_destroy(nfs4_layout_cache);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void
+nfsd4_exit_pnfs(void)
+{
+	int i;
+
+	kmem_cache_destroy(nfs4_layout_cache);
+	kmem_cache_destroy(nfs4_layout_stateid_cache);
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++) {
+		struct nfsd4_deviceid_map *map, *n;
+
+		list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
+			kfree(map);
+	}
+}
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
new file mode 100644
index 000000000..50c07561e
--- /dev/null
+++ b/fs/nfsd/nfs4proc.c
@@ -0,0 +1,4273 @@
+/*
+ *  Server-side procedures for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/fs_struct.h>
+#include <linux/file.h>
+#include <linux/falloc.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/namei.h>
+
+#include <linux/sunrpc/addr.h>
+#include <linux/nfs_ssc.h>
+
+#include "attr4.h"
+#include "idmap.h"
+#include "cache.h"
+#include "xdr4.h"
+#include "vfs.h"
+#include "current_stateid.h"
+#include "netns.h"
+#include "acl.h"
+#include "pnfs.h"
+#include "trace.h"
+
+static bool inter_copy_offload_enable;
+module_param(inter_copy_offload_enable, bool, 0644);
+MODULE_PARM_DESC(inter_copy_offload_enable,
+		 "Enable inter server to server copy offload. Default: false");
+
+static void cleanup_async_copy(struct nfsd4_async_copy *copy);
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+static int nfsd4_ssc_umount_timeout = 900000;		/* default to 15 mins */
+module_param(nfsd4_ssc_umount_timeout, int, 0644);
+MODULE_PARM_DESC(nfsd4_ssc_umount_timeout,
+		"idle msecs before unmount export from source server");
+#endif
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static u32 nfsd_attrmask[] = {
+	NFSD_WRITEABLE_ATTRS_WORD0,
+	NFSD_WRITEABLE_ATTRS_WORD1,
+	NFSD_WRITEABLE_ATTRS_WORD2
+};
+
+static u32 nfsd41_ex_attrmask[] = {
+	NFSD_SUPPATTR_EXCLCREAT_WORD0,
+	NFSD_SUPPATTR_EXCLCREAT_WORD1,
+	NFSD_SUPPATTR_EXCLCREAT_WORD2
+};
+
+static __be32
+check_attr_support(struct nfsd4_compound_state *cstate, u32 *bmval,
+		   u32 *writable)
+{
+	struct dentry *dentry = cstate->current_fh.fh_dentry;
+	struct svc_export *exp = cstate->current_fh.fh_export;
+
+	if (!nfsd_attrs_supported(cstate->minorversion, bmval))
+		return nfserr_attrnotsupp;
+	if ((bmval[0] & FATTR4_WORD0_ACL) && !IS_POSIXACL(d_inode(dentry)))
+		return nfserr_attrnotsupp;
+	if ((bmval[2] & (FATTR4_WORD2_POSIX_DEFAULT_ACL |
+					FATTR4_WORD2_POSIX_ACCESS_ACL)) &&
+					!IS_POSIXACL(d_inode(dentry)))
+		return nfserr_attrnotsupp;
+	if ((bmval[2] & FATTR4_WORD2_SECURITY_LABEL) &&
+			!(exp->ex_flags & NFSEXP_SECURITY_LABEL))
+		return nfserr_attrnotsupp;
+	if (writable && !bmval_is_subset(bmval, writable))
+		return nfserr_inval;
+	if (writable && (bmval[2] & FATTR4_WORD2_MODE_UMASK) &&
+			(bmval[1] & FATTR4_WORD1_MODE))
+		return nfserr_inval;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_check_open_attributes(struct nfsd4_compound_state *cstate,
+			    struct nfsd4_open *open)
+{
+	__be32 status = nfs_ok;
+
+	if (open->op_create != NFS4_OPEN_CREATE)
+		return status;
+
+	switch (open->op_createmode) {
+	case NFS4_CREATE_UNCHECKED:
+	case NFS4_CREATE_GUARDED:
+		status = check_attr_support(cstate, open->op_bmval,
+					    nfsd_attrmask);
+		break;
+	case NFS4_CREATE_EXCLUSIVE4_1:
+		status = check_attr_support(cstate, open->op_bmval,
+					    nfsd41_ex_attrmask);
+		break;
+	}
+	return status;
+}
+
+static int
+is_create_with_attrs(struct nfsd4_open *open)
+{
+	return open->op_create == NFS4_OPEN_CREATE
+		&& (open->op_createmode == NFS4_CREATE_UNCHECKED
+		    || open->op_createmode == NFS4_CREATE_GUARDED
+		    || open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1);
+}
+
+static inline void
+fh_dup2(struct svc_fh *dst, struct svc_fh *src)
+{
+	fh_put(dst);
+	dget(src->fh_dentry);
+	if (src->fh_export)
+		exp_get(src->fh_export);
+	*dst = *src;
+}
+
+static __be32
+do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open, int accmode)
+{
+
+	if (open->op_truncate &&
+		!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
+		return nfserr_inval;
+
+	accmode |= NFSD_MAY_READ_IF_EXEC;
+
+	if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
+		accmode |= NFSD_MAY_READ;
+	if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
+		accmode |= (NFSD_MAY_WRITE | NFSD_MAY_TRUNC);
+	if (open->op_share_deny & NFS4_SHARE_DENY_READ)
+		accmode |= NFSD_MAY_WRITE;
+
+	return fh_verify(rqstp, current_fh, S_IFREG, accmode);
+}
+
+static __be32 nfsd_check_obj_isreg(struct svc_fh *fh, u32 minor_version)
+{
+	umode_t mode = d_inode(fh->fh_dentry)->i_mode;
+
+	if (S_ISREG(mode))
+		return nfs_ok;
+	if (S_ISDIR(mode))
+		return nfserr_isdir;
+	if (S_ISLNK(mode))
+		return nfserr_symlink;
+
+	/* RFC 7530 - 16.16.6 */
+	if (minor_version == 0)
+		return nfserr_symlink;
+	else
+		return nfserr_wrong_type;
+
+}
+
+static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
+{
+	if (nfsd4_has_session(cstate))
+		return;
+	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
+			&resfh->fh_handle);
+}
+
+static inline bool nfsd4_create_is_exclusive(int createmode)
+{
+	return createmode == NFS4_CREATE_EXCLUSIVE ||
+		createmode == NFS4_CREATE_EXCLUSIVE4_1;
+}
+
+static __be32
+nfsd4_vfs_create(struct svc_fh *fhp, struct dentry **child,
+		 struct nfsd4_open *open)
+{
+	struct file *filp;
+	struct path path;
+	int oflags;
+
+	oflags = O_CREAT | O_LARGEFILE;
+	if (nfsd4_create_is_exclusive(open->op_createmode))
+		oflags |= O_EXCL;
+
+	switch (open->op_share_access & NFS4_SHARE_ACCESS_BOTH) {
+	case NFS4_SHARE_ACCESS_WRITE:
+		oflags |= O_WRONLY;
+		break;
+	case NFS4_SHARE_ACCESS_BOTH:
+		oflags |= O_RDWR;
+		break;
+	default:
+		oflags |= O_RDONLY;
+	}
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = *child;
+	filp = dentry_create(&path, oflags, open->op_iattr.ia_mode,
+			     current_cred());
+	*child = path.dentry;
+
+	if (IS_ERR(filp))
+		return nfserrno(PTR_ERR(filp));
+
+	open->op_filp = filp;
+	return nfs_ok;
+}
+
+/*
+ * Implement NFSv4's unchecked, guarded, and exclusive create
+ * semantics for regular files. Open state for this new file is
+ * subsequently fabricated in nfsd4_process_open2().
+ *
+ * Upon return, caller must release @fhp and @resfhp.
+ */
+static __be32
+nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct svc_fh *resfhp, struct nfsd4_open *open)
+{
+	struct iattr *iap = &open->op_iattr;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= iap,
+		.na_seclabel	= &open->op_label,
+	};
+	struct dentry *parent, *child = ERR_PTR(-EINVAL);
+	__u32 v_mtime, v_atime;
+	struct inode *inode;
+	__be32 status;
+	int host_err;
+
+	if (name_is_dot_dotdot(open->op_fname, open->op_fnamelen))
+		return nfserr_exist;
+	if (!(iap->ia_valid & ATTR_MODE))
+		iap->ia_mode = 0;
+
+	status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (status != nfs_ok)
+		return status;
+	parent = fhp->fh_dentry;
+	inode = d_inode(parent);
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		return nfserrno(host_err);
+
+	if (open->op_acl) {
+		if (open->op_dpacl || open->op_pacl) {
+			status = nfserr_inval;
+			goto out;
+		}
+		if (is_create_with_attrs(open)) {
+			status = nfsd4_acl_to_attr(NF4REG, open->op_acl,
+						   &attrs);
+			if (status)
+				goto out;
+		}
+	} else if (is_create_with_attrs(open)) {
+		/* The dpacl and pacl will get released by nfsd_attrs_free(). */
+		attrs.na_dpacl = open->op_dpacl;
+		attrs.na_pacl = open->op_pacl;
+		open->op_dpacl = NULL;
+		open->op_pacl = NULL;
+	}
+
+	child = start_creating(&nop_mnt_idmap, parent,
+			       &QSTR_LEN(open->op_fname, open->op_fnamelen));
+	if (IS_ERR(child)) {
+		status = nfserrno(PTR_ERR(child));
+		goto out;
+	}
+
+	if (d_really_is_negative(child)) {
+		status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+		if (status != nfs_ok)
+			goto out;
+	}
+
+	v_mtime = 0;
+	v_atime = 0;
+	if (nfsd4_create_is_exclusive(open->op_createmode)) {
+		u32 *verifier = (u32 *)open->op_verf.data;
+
+		/*
+		 * Solaris 7 gets confused (bugid 4218508) if these have
+		 * the high bit set, as do xfs filesystems without the
+		 * "bigtime" feature. So just clear the high bits. If this
+		 * is ever changed to use different attrs for storing the
+		 * verifier, then do_open_lookup() will also need to be
+		 * fixed accordingly.
+		 */
+		v_mtime = verifier[0] & 0x7fffffff;
+		v_atime = verifier[1] & 0x7fffffff;
+	}
+
+	if (d_really_is_positive(child)) {
+		/* NFSv4 protocol requires change attributes even though
+		 * no change happened.
+		 */
+		status = fh_fill_both_attrs(fhp);
+		if (status != nfs_ok)
+			goto out;
+
+		status = fh_compose(resfhp, fhp->fh_export, child, fhp);
+		if (status != nfs_ok)
+			goto out;
+
+		switch (open->op_createmode) {
+		case NFS4_CREATE_UNCHECKED:
+			if (!d_is_reg(child))
+				break;
+
+			/*
+			 * In NFSv4, we don't want to truncate the file
+			 * now. This would be wrong if the OPEN fails for
+			 * some other reason. Furthermore, if the size is
+			 * nonzero, we should ignore it according to spec!
+			 */
+			open->op_truncate = (iap->ia_valid & ATTR_SIZE) &&
+						!iap->ia_size;
+			break;
+		case NFS4_CREATE_GUARDED:
+			status = nfserr_exist;
+			break;
+		case NFS4_CREATE_EXCLUSIVE:
+			if (inode_get_mtime_sec(d_inode(child)) == v_mtime &&
+			    inode_get_atime_sec(d_inode(child)) == v_atime &&
+			    d_inode(child)->i_size == 0) {
+				open->op_created = true;
+				break;		/* subtle */
+			}
+			status = nfserr_exist;
+			break;
+		case NFS4_CREATE_EXCLUSIVE4_1:
+			if (inode_get_mtime_sec(d_inode(child)) == v_mtime &&
+			    inode_get_atime_sec(d_inode(child)) == v_atime &&
+			    d_inode(child)->i_size == 0) {
+				open->op_created = true;
+				goto set_attr;	/* subtle */
+			}
+			status = nfserr_exist;
+		}
+		goto out;
+	}
+
+	if (!IS_POSIXACL(inode))
+		iap->ia_mode &= ~current_umask();
+
+	status = fh_fill_pre_attrs(fhp);
+	if (status != nfs_ok)
+		goto out;
+	status = nfsd4_vfs_create(fhp, &child, open);
+	if (status != nfs_ok)
+		goto out;
+	open->op_created = true;
+	fh_fill_post_attrs(fhp);
+
+	status = fh_compose(resfhp, fhp->fh_export, child, fhp);
+	if (status != nfs_ok)
+		goto out;
+
+	/* A newly created file already has a file size of zero. */
+	if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+		iap->ia_valid &= ~ATTR_SIZE;
+	if (nfsd4_create_is_exclusive(open->op_createmode)) {
+		iap->ia_valid = ATTR_MTIME | ATTR_ATIME |
+				ATTR_MTIME_SET|ATTR_ATIME_SET;
+		iap->ia_mtime.tv_sec = v_mtime;
+		iap->ia_atime.tv_sec = v_atime;
+		iap->ia_mtime.tv_nsec = 0;
+		iap->ia_atime.tv_nsec = 0;
+	}
+
+set_attr:
+	status = nfsd_create_setattr(rqstp, fhp, resfhp, &attrs);
+
+	if (attrs.na_labelerr)
+		open->op_bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+	if (attrs.na_paclerr || attrs.na_dpaclerr)
+		open->op_bmval[0] &= ~FATTR4_WORD0_ACL;
+	if (attrs.na_dpaclerr)
+		open->op_bmval[2] &= ~FATTR4_WORD2_POSIX_DEFAULT_ACL;
+	if (attrs.na_paclerr)
+		open->op_bmval[2] &= ~FATTR4_WORD2_POSIX_ACCESS_ACL;
+out:
+	end_creating(child);
+	nfsd_attrs_free(&attrs);
+	fh_drop_write(fhp);
+	return status;
+}
+
+/**
+ * set_change_info - set up the change_info4 for a reply
+ * @cinfo: pointer to nfsd4_change_info to be populated
+ * @fhp: pointer to svc_fh to use as source
+ *
+ * Many operations in NFSv4 require change_info4 in the reply. This function
+ * populates that from the info that we (should!) have already collected. In
+ * the event that we didn't get any pre-attrs, just zero out both.
+ */
+static void
+set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
+{
+	cinfo->atomic = (u32)(fhp->fh_pre_saved && fhp->fh_post_saved && !fhp->fh_no_atomic_attr);
+	cinfo->before_change = fhp->fh_pre_change;
+	cinfo->after_change = fhp->fh_post_change;
+
+	/*
+	 * If fetching the pre-change attributes failed, then we should
+	 * have already failed the whole operation. We could have still
+	 * failed to fetch post-change attributes however.
+	 *
+	 * If we didn't get post-op attrs, just zero-out the after
+	 * field since we don't know what it should be. If the pre_saved
+	 * field isn't set for some reason, throw warning and just copy
+	 * whatever is in the after field.
+	 */
+	if (WARN_ON_ONCE(!fhp->fh_pre_saved))
+		cinfo->before_change = 0;
+	if (!fhp->fh_post_saved)
+		cinfo->after_change = cinfo->before_change + 1;
+}
+
+static __be32
+do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh **resfh)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	int accmode;
+	__be32 status;
+
+	*resfh = kmalloc_obj(struct svc_fh);
+	if (!*resfh)
+		return nfserr_jukebox;
+	fh_init(*resfh, NFS4_FHSIZE);
+	open->op_truncate = false;
+
+	if (open->op_create) {
+		/* FIXME: check session persistence and pnfs flags.
+		 * The nfsv4.1 spec requires the following semantics:
+		 *
+		 * Persistent   | pNFS   | Server REQUIRED | Client Allowed
+		 * Reply Cache  | server |                 |
+		 * -------------+--------+-----------------+--------------------
+		 * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
+		 *              |        |                 | (SHOULD)
+		 *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
+		 *              |        |                 | (SHOULD NOT)
+		 * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
+		 * yes          | no     | GUARDED4        | GUARDED4
+		 * yes          | yes    | GUARDED4        | GUARDED4
+		 */
+
+		current->fs->umask = open->op_umask;
+		status = nfsd4_create_file(rqstp, current_fh, *resfh, open);
+		current->fs->umask = 0;
+
+		/*
+		 * Following rfc 3530 14.2.16, and rfc 5661 18.16.4
+		 * use the returned bitmask to indicate which attributes
+		 * we used to store the verifier:
+		 */
+		if (nfsd4_create_is_exclusive(open->op_createmode) && status == 0)
+			open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
+						FATTR4_WORD1_TIME_MODIFY);
+	} else {
+		status = nfsd_lookup(rqstp, current_fh,
+				     open->op_fname, open->op_fnamelen, *resfh);
+		if (status == nfs_ok)
+			/* NFSv4 protocol requires change attributes even though
+			 * no change happened.
+			 */
+			status = fh_fill_both_attrs(current_fh);
+	}
+	if (status)
+		goto out;
+	status = nfsd_check_obj_isreg(*resfh, cstate->minorversion);
+	if (status)
+		goto out;
+
+	nfsd4_set_open_owner_reply_cache(cstate, open, *resfh);
+	accmode = NFSD_MAY_NOP;
+	if (open->op_created ||
+			open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
+		accmode |= NFSD_MAY_OWNER_OVERRIDE;
+	status = do_open_permission(rqstp, *resfh, open, accmode);
+	set_change_info(&open->op_cinfo, current_fh);
+out:
+	return status;
+}
+
+static __be32
+do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	int accmode = 0;
+
+	/* We don't know the target directory, and therefore can not
+	* set the change info
+	*/
+
+	memset(&open->op_cinfo, 0, sizeof(struct nfsd4_change_info));
+
+	nfsd4_set_open_owner_reply_cache(cstate, open, current_fh);
+
+	open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
+		(open->op_iattr.ia_size == 0);
+	/*
+	 * In the delegation case, the client is telling us about an
+	 * open that it *already* performed locally, some time ago.  We
+	 * should let it succeed now if possible.
+	 *
+	 * In the case of a CLAIM_FH open, on the other hand, the client
+	 * may be counting on us to enforce permissions (the Linux 4.1
+	 * client uses this for normal opens, for example).
+	 */
+	if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH)
+		accmode = NFSD_MAY_OWNER_OVERRIDE;
+
+	return do_open_permission(rqstp, current_fh, open, accmode);
+}
+
+static void
+copy_clientid(clientid_t *clid, struct nfsd4_session *session)
+{
+	struct nfsd4_sessionid *sid =
+			(struct nfsd4_sessionid *)session->se_sessionid.data;
+
+	clid->cl_boot = sid->clientid.cl_boot;
+	clid->cl_id = sid->clientid.cl_id;
+}
+
+static __be32
+nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	__be32 status;
+	struct svc_fh *resfh = NULL;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	bool reclaim = false;
+
+	dprintk("NFSD: nfsd4_open filename %.*s op_openowner %p\n",
+		(int)open->op_fnamelen, open->op_fname,
+		open->op_openowner);
+
+	open->op_filp = NULL;
+	open->op_rqstp = rqstp;
+
+	/* This check required by spec. */
+	if (open->op_create && open->op_claim_type != NFS4_OPEN_CLAIM_NULL) {
+		status = nfserr_inval;
+		goto out_err;
+	}
+
+	open->op_created = false;
+	/*
+	 * RFC5661 18.51.3
+	 * Before RECLAIM_COMPLETE done, server should deny new lock
+	 */
+	if (nfsd4_has_session(cstate) &&
+	    !test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &cstate->clp->cl_flags) &&
+	    open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS) {
+		status = nfserr_grace;
+		goto out_err;
+	}
+
+	if (nfsd4_has_session(cstate))
+		copy_clientid(&open->op_clientid, cstate->session);
+
+	/* check seqid for replay. set nfs4_owner */
+	status = nfsd4_process_open1(cstate, open, nn);
+	if (status == nfserr_replay_me) {
+		struct nfs4_replay *rp = &open->op_openowner->oo_owner.so_replay;
+		fh_put(&cstate->current_fh);
+		fh_copy_shallow(&cstate->current_fh.fh_handle,
+				&rp->rp_openfh);
+		status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+		if (status)
+			dprintk("nfsd4_open: replay failed"
+				" restoring previous filehandle\n");
+		else
+			status = nfserr_replay_me;
+	}
+	if (status)
+		goto out;
+	if (open->op_xdr_error) {
+		status = open->op_xdr_error;
+		goto out;
+	}
+
+	status = nfsd4_check_open_attributes(cstate, open);
+	if (status)
+		goto out;
+
+	/* Openowner is now set, so sequence id will get bumped.  Now we need
+	 * these checks before we do any creates: */
+	status = nfserr_grace;
+	if (opens_in_grace(net) && open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
+		goto out;
+	status = nfserr_no_grace;
+	if (!opens_in_grace(net) && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
+		goto out;
+
+	switch (open->op_claim_type) {
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+	case NFS4_OPEN_CLAIM_NULL:
+		status = do_open_lookup(rqstp, cstate, open, &resfh);
+		if (status)
+			goto out;
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		status = nfs4_check_open_reclaim(cstate->clp);
+		if (status)
+			goto out;
+		open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+		reclaim = true;
+		fallthrough;
+	case NFS4_OPEN_CLAIM_FH:
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		status = do_open_fhandle(rqstp, cstate, open);
+		if (status)
+			goto out;
+		resfh = &cstate->current_fh;
+		break;
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		status = nfserr_notsupp;
+		goto out;
+	default:
+		status = nfserr_inval;
+		goto out;
+	}
+
+	status = nfsd4_process_open2(rqstp, resfh, open);
+	if (status && open->op_created)
+		pr_warn("nfsd4_process_open2 failed to open newly-created file: status=%u\n",
+			be32_to_cpu(status));
+	if (reclaim && !status)
+		set_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags);
+out:
+	if (open->op_filp) {
+		fput(open->op_filp);
+		open->op_filp = NULL;
+	}
+	if (resfh && resfh != &cstate->current_fh) {
+		fh_dup2(&cstate->current_fh, resfh);
+		fh_put(resfh);
+		kfree(resfh);
+	}
+	nfsd4_cleanup_open_state(cstate, open);
+	nfsd4_bump_seqid(cstate, status);
+out_err:
+	return status;
+}
+
+/*
+ * OPEN is the only seqid-mutating operation whose decoding can fail
+ * with a seqid-mutating error (specifically, decoding of user names in
+ * the attributes).  Therefore we have to do some processing to look up
+ * the stateowner so that we can bump the seqid.
+ */
+static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
+{
+	struct nfsd4_open *open = &op->u.open;
+
+	if (!seqid_mutating_err(ntohl(op->status)))
+		return op->status;
+	if (nfsd4_has_session(cstate))
+		return op->status;
+	open->op_xdr_error = op->status;
+	return nfsd4_open(rqstp, cstate, &op->u);
+}
+
+static void
+nfsd4_open_release(union nfsd4_op_u *u)
+{
+	posix_acl_release(u->open.op_dpacl);
+	posix_acl_release(u->open.op_pacl);
+}
+
+/*
+ * filehandle-manipulating ops.
+ */
+static __be32
+nfsd4_getfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	u->getfh = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_putfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_putfh *putfh = &u->putfh;
+	__be32 ret;
+
+	fh_put(&cstate->current_fh);
+	cstate->current_fh.fh_handle.fh_size = putfh->pf_fhlen;
+	memcpy(&cstate->current_fh.fh_handle.fh_raw, putfh->pf_fhval,
+	       putfh->pf_fhlen);
+	ret = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+	if (ret == nfserr_stale && putfh->no_verify) {
+		SET_FH_FLAG(&cstate->current_fh, NFSD4_FH_FOREIGN);
+		ret = 0;
+	}
+#endif
+	return ret;
+}
+
+static __be32
+nfsd4_putrootfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	fh_put(&cstate->current_fh);
+
+	return exp_pseudoroot(rqstp, &cstate->current_fh);
+}
+
+static __be32
+nfsd4_restorefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	if (!cstate->save_fh.fh_dentry)
+		return nfserr_restorefh;
+
+	fh_dup2(&cstate->current_fh, &cstate->save_fh);
+	if (HAS_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG)) {
+		memcpy(&cstate->current_stateid, &cstate->save_stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+	}
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	fh_dup2(&cstate->save_fh, &cstate->current_fh);
+	if (HAS_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG)) {
+		memcpy(&cstate->save_stateid, &cstate->current_stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG);
+	}
+	return nfs_ok;
+}
+
+/*
+ * misc nfsv4 ops
+ */
+static __be32
+nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	u32 access_full;
+
+	access_full = NFS3_ACCESS_FULL;
+	if (cstate->minorversion >= 2)
+		access_full |= NFS4_ACCESS_XALIST | NFS4_ACCESS_XAREAD |
+			       NFS4_ACCESS_XAWRITE;
+
+	if (access->ac_req_access & ~access_full)
+		return nfserr_inval;
+
+	access->ac_resp_access = access->ac_req_access;
+	return nfsd_access(rqstp, &cstate->current_fh, &access->ac_resp_access,
+			   &access->ac_supported);
+}
+
+static __be32
+nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+	struct nfsd_file *nf;
+	__be32 status;
+
+	status = nfsd_file_acquire(rqstp, &cstate->current_fh, NFSD_MAY_WRITE |
+				   NFSD_MAY_NOT_BREAK_LEASE, &nf);
+	if (status != nfs_ok)
+		return status;
+
+	status = nfsd_commit(rqstp, &cstate->current_fh, nf, commit->co_offset,
+			     commit->co_count,
+			     (__be32 *)commit->co_verf.data);
+	nfsd_file_put(nf);
+	return status;
+}
+
+static __be32
+nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &create->cr_iattr,
+		.na_seclabel	= &create->cr_label,
+		.na_dpacl	= create->cr_dpacl,
+		.na_pacl	= create->cr_pacl,
+	};
+	struct svc_fh resfh;
+	__be32 status;
+	dev_t rdev;
+
+	create->cr_dpacl = NULL;
+	create->cr_pacl = NULL;
+
+	fh_init(&resfh, NFS4_FHSIZE);
+
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_NOP);
+	if (status)
+		goto out_aftermask;
+
+	status = check_attr_support(cstate, create->cr_bmval, nfsd_attrmask);
+	if (status)
+		goto out_aftermask;
+
+	/* Sanitize cr_type to avoid returning ATTRNOTSUPP. */
+	switch (create->cr_type) {
+	case NF4LNK:
+	case NF4BLK:
+	case NF4CHR:
+	case NF4SOCK:
+	case NF4FIFO:
+	case NF4DIR:
+		break;
+	default:
+		status = nfserr_badtype;
+		goto out_aftermask;
+	}
+
+	if (create->cr_acl) {
+		if (attrs.na_dpacl || attrs.na_pacl) {
+			status = nfserr_inval;
+			goto out_aftermask;
+		}
+		status = nfsd4_acl_to_attr(create->cr_type, create->cr_acl,
+								&attrs);
+		if (status != nfs_ok)
+			goto out_aftermask;
+	}
+	current->fs->umask = create->cr_umask;
+	switch (create->cr_type) {
+	case NF4LNK:
+		status = nfsd_symlink(rqstp, &cstate->current_fh,
+				      create->cr_name, create->cr_namelen,
+				      create->cr_data, &attrs, &resfh);
+		break;
+
+	case NF4BLK:
+		status = nfserr_inval;
+		rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
+		if (MAJOR(rdev) != create->cr_specdata1 ||
+		    MINOR(rdev) != create->cr_specdata2)
+			goto out_umask;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &attrs, S_IFBLK, rdev, &resfh);
+		break;
+
+	case NF4CHR:
+		status = nfserr_inval;
+		rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
+		if (MAJOR(rdev) != create->cr_specdata1 ||
+		    MINOR(rdev) != create->cr_specdata2)
+			goto out_umask;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &attrs, S_IFCHR, rdev, &resfh);
+		break;
+
+	case NF4SOCK:
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &attrs, S_IFSOCK, 0, &resfh);
+		break;
+
+	case NF4FIFO:
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &attrs, S_IFIFO, 0, &resfh);
+		break;
+
+	case NF4DIR:
+		create->cr_iattr.ia_valid &= ~ATTR_SIZE;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &attrs, S_IFDIR, 0, &resfh);
+		break;
+
+	default:
+		status = nfserr_badtype;
+	}
+
+	if (status)
+		goto out;
+
+	if (attrs.na_labelerr)
+		create->cr_bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+	if (attrs.na_paclerr || attrs.na_dpaclerr)
+		create->cr_bmval[0] &= ~FATTR4_WORD0_ACL;
+	if (attrs.na_dpaclerr)
+		create->cr_bmval[2] &= ~FATTR4_WORD2_POSIX_DEFAULT_ACL;
+	if (attrs.na_paclerr)
+		create->cr_bmval[2] &= ~FATTR4_WORD2_POSIX_ACCESS_ACL;
+	set_change_info(&create->cr_cinfo, &cstate->current_fh);
+	fh_dup2(&cstate->current_fh, &resfh);
+out:
+	fh_put(&resfh);
+out_umask:
+	current->fs->umask = 0;
+out_aftermask:
+	nfsd_attrs_free(&attrs);
+	return status;
+}
+
+static __be32
+nfsd4_getattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	__be32 status;
+
+	trace_nfsd_vfs_getattr(rqstp, &cstate->current_fh);
+
+	status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+	if (status)
+		return status;
+
+	if (getattr->ga_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
+		return nfserr_inval;
+
+	getattr->ga_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
+	getattr->ga_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
+	getattr->ga_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
+
+	getattr->ga_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_link(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	__be32 status;
+
+	status = nfsd_link(rqstp, &cstate->current_fh,
+			   link->li_name, link->li_namelen, &cstate->save_fh);
+	if (!status)
+		set_change_info(&link->li_cinfo, &cstate->current_fh);
+	return status;
+}
+
+static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
+{
+	struct svc_fh tmp_fh;
+	__be32 ret;
+
+	fh_init(&tmp_fh, NFS4_FHSIZE);
+	ret = exp_pseudoroot(rqstp, &tmp_fh);
+	if (ret)
+		return ret;
+	if (tmp_fh.fh_dentry == fh->fh_dentry) {
+		fh_put(&tmp_fh);
+		return nfserr_noent;
+	}
+	fh_put(&tmp_fh);
+	return nfsd_lookup(rqstp, fh, "..", 2, fh);
+}
+
+static __be32
+nfsd4_lookupp(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	return nfsd4_do_lookupp(rqstp, &cstate->current_fh);
+}
+
+static __be32
+nfsd4_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	return nfsd_lookup(rqstp, &cstate->current_fh,
+			   u->lookup.lo_name, u->lookup.lo_len,
+			   &cstate->current_fh);
+}
+
+static __be32
+nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	__be32 status;
+
+	read->rd_nf = NULL;
+
+	trace_nfsd_read_start(rqstp, &cstate->current_fh,
+			      read->rd_offset, read->rd_length);
+
+	read->rd_length = min_t(u32, read->rd_length, svc_max_payload(rqstp));
+	if (read->rd_offset > (u64)OFFSET_MAX)
+		read->rd_offset = (u64)OFFSET_MAX;
+	if (read->rd_offset + read->rd_length > (u64)OFFSET_MAX)
+		read->rd_length = (u64)OFFSET_MAX - read->rd_offset;
+
+	/*
+	 * If we do a zero copy read, then a client will see read data
+	 * that reflects the state of the file *after* performing the
+	 * following compound.
+	 *
+	 * To ensure proper ordering, we therefore turn off zero copy if
+	 * the client wants us to do more in this compound:
+	 */
+	if (!nfsd4_last_compound_op(rqstp)) {
+		struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+		argp->splice_ok = false;
+	}
+
+	/* check stateid */
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					&read->rd_stateid, RD_STATE,
+					&read->rd_nf, NULL);
+
+	read->rd_rqstp = rqstp;
+	read->rd_fhp = &cstate->current_fh;
+	return status;
+}
+
+
+static void
+nfsd4_read_release(union nfsd4_op_u *u)
+{
+	if (u->read.rd_nf) {
+		trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
+				     u->read.rd_offset, u->read.rd_length);
+		nfsd_file_put(u->read.rd_nf);
+	}
+}
+
+static __be32
+nfsd4_readdir(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	u64 cookie = readdir->rd_cookie;
+	static const nfs4_verifier zeroverf;
+
+	trace_nfsd_vfs_readdir(rqstp, &cstate->current_fh,
+			       readdir->rd_maxcount, readdir->rd_cookie);
+
+	/* no need to check permission - this will be done in nfsd_readdir() */
+
+	if (readdir->rd_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
+		return nfserr_inval;
+
+	readdir->rd_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
+	readdir->rd_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
+	readdir->rd_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
+
+	if ((cookie == 1) || (cookie == 2) ||
+	    (cookie == 0 && memcmp(readdir->rd_verf.data, zeroverf.data, NFS4_VERIFIER_SIZE)))
+		return nfserr_bad_cookie;
+
+	readdir->rd_rqstp = rqstp;
+	readdir->rd_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_readlink(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	u->readlink.rl_rqstp = rqstp;
+	u->readlink.rl_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_remove(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	__be32 status;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+	status = nfsd_unlink(rqstp, &cstate->current_fh, 0,
+			     remove->rm_name, remove->rm_namelen);
+	if (!status)
+		set_change_info(&remove->rm_cinfo, &cstate->current_fh);
+	return status;
+}
+
+static __be32
+nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	__be32 status;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+	status = nfsd_rename(rqstp, &cstate->save_fh, rename->rn_sname,
+			     rename->rn_snamelen, &cstate->current_fh,
+			     rename->rn_tname, rename->rn_tnamelen);
+	if (status)
+		return status;
+	set_change_info(&rename->rn_sinfo, &cstate->save_fh);
+	set_change_info(&rename->rn_tinfo, &cstate->current_fh);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	struct svc_export *exp;
+	struct dentry *dentry;
+	__be32 err;
+
+	err = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		return err;
+	err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
+				    secinfo->si_name, secinfo->si_namelen,
+				    &exp, &dentry);
+	if (err)
+		return err;
+	if (d_really_is_negative(dentry)) {
+		exp_put(exp);
+		err = nfserr_noent;
+	} else
+		secinfo->si_exp = exp;
+	dput(dentry);
+	if (cstate->minorversion)
+		/* See rfc 5661 section 2.6.3.1.1.8 */
+		fh_put(&cstate->current_fh);
+	return err;
+}
+
+static __be32
+nfsd4_secinfo_no_name(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	__be32 err;
+
+	switch (u->secinfo_no_name.sin_style) {
+	case NFS4_SECINFO_STYLE4_CURRENT_FH:
+		break;
+	case NFS4_SECINFO_STYLE4_PARENT:
+		err = nfsd4_do_lookupp(rqstp, &cstate->current_fh);
+		if (err)
+			return err;
+		break;
+	default:
+		return nfserr_inval;
+	}
+
+	u->secinfo_no_name.sin_exp = exp_get(cstate->current_fh.fh_export);
+	fh_put(&cstate->current_fh);
+	return nfs_ok;
+}
+
+static void
+nfsd4_secinfo_release(union nfsd4_op_u *u)
+{
+	if (u->secinfo.si_exp)
+		exp_put(u->secinfo.si_exp);
+}
+
+static void
+nfsd4_secinfo_no_name_release(union nfsd4_op_u *u)
+{
+	if (u->secinfo_no_name.sin_exp)
+		exp_put(u->secinfo_no_name.sin_exp);
+}
+
+/*
+ * Validate that the requested timestamps are within the acceptable range. If
+ * timestamp appears to be in the future, then it will be clamped to
+ * current_time().
+ */
+static void
+vet_deleg_attrs(struct nfsd4_setattr *setattr, struct nfs4_delegation *dp)
+{
+	struct timespec64 now = current_time(dp->dl_stid.sc_file->fi_inode);
+	struct iattr *iattr = &setattr->sa_iattr;
+
+	if ((setattr->sa_bmval[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) &&
+	    !nfsd4_vet_deleg_time(&iattr->ia_atime, &dp->dl_atime, &now))
+		iattr->ia_valid &= ~(ATTR_ATIME | ATTR_ATIME_SET);
+
+	if (setattr->sa_bmval[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
+		if (nfsd4_vet_deleg_time(&iattr->ia_mtime, &dp->dl_mtime, &now)) {
+			iattr->ia_ctime = iattr->ia_mtime;
+			if (nfsd4_vet_deleg_time(&iattr->ia_ctime, &dp->dl_ctime, &now))
+				dp->dl_setattr = true;
+			else
+				iattr->ia_valid &= ~(ATTR_CTIME | ATTR_CTIME_SET);
+		} else {
+			iattr->ia_valid &= ~(ATTR_CTIME | ATTR_CTIME_SET |
+					     ATTR_MTIME | ATTR_MTIME_SET);
+		}
+	}
+}
+
+static __be32
+nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &setattr->sa_iattr,
+		.na_seclabel	= &setattr->sa_label,
+		.na_pacl	= setattr->sa_pacl,
+		.na_dpacl	= setattr->sa_dpacl,
+	};
+	bool save_no_wcc, deleg_attrs;
+	struct nfs4_stid *st = NULL;
+	struct inode *inode;
+	__be32 status = nfs_ok;
+	int err;
+
+	/* Transfer ownership to attrs for cleanup via nfsd_attrs_free() */
+	setattr->sa_pacl = NULL;
+	setattr->sa_dpacl = NULL;
+
+	deleg_attrs = setattr->sa_bmval[2] & (FATTR4_WORD2_TIME_DELEG_ACCESS |
+					      FATTR4_WORD2_TIME_DELEG_MODIFY);
+
+	if (deleg_attrs || (setattr->sa_iattr.ia_valid & ATTR_SIZE)) {
+		int flags = WR_STATE;
+
+		if (setattr->sa_bmval[2] & FATTR4_WORD2_TIME_DELEG_ACCESS)
+			flags |= RD_STATE;
+
+		status = nfs4_preprocess_stateid_op(rqstp, cstate,
+				&cstate->current_fh, &setattr->sa_stateid,
+				flags, NULL, &st);
+		if (status)
+			goto out_err;
+	}
+
+	if (deleg_attrs) {
+		status = nfserr_bad_stateid;
+		if (st && (st->sc_type & SC_TYPE_DELEG)) {
+			struct nfs4_delegation *dp = delegstateid(st);
+
+			/* Only for *_ATTRS_DELEG flavors */
+			if (deleg_attrs_deleg(dp->dl_type)) {
+				vet_deleg_attrs(setattr, dp);
+				status = nfs_ok;
+			}
+		}
+	}
+	if (st)
+		nfs4_put_stid(st);
+	if (status)
+		goto out_err;
+
+	err = fh_want_write(&cstate->current_fh);
+	if (err) {
+		status = nfserrno(err);
+		goto out_err;
+	}
+	status = nfs_ok;
+
+	status = check_attr_support(cstate, setattr->sa_bmval, nfsd_attrmask);
+	if (status)
+		goto out;
+
+	if (setattr->sa_acl && (attrs.na_dpacl || attrs.na_pacl)) {
+		status = nfserr_inval;
+		goto out;
+	}
+
+	inode = cstate->current_fh.fh_dentry->d_inode;
+	status = nfsd4_acl_to_attr(S_ISDIR(inode->i_mode) ? NF4DIR : NF4REG,
+				   setattr->sa_acl, &attrs);
+
+	if (status)
+		goto out;
+	save_no_wcc = cstate->current_fh.fh_no_wcc;
+	cstate->current_fh.fh_no_wcc = true;
+	status = nfsd_setattr(rqstp, &cstate->current_fh, &attrs, NULL);
+	cstate->current_fh.fh_no_wcc = save_no_wcc;
+	if (!status)
+		status = nfserrno(attrs.na_labelerr);
+	if (!status)
+		status = nfserrno(attrs.na_dpaclerr);
+	if (!status)
+		status = nfserrno(attrs.na_paclerr);
+out:
+	fh_drop_write(&cstate->current_fh);
+out_err:
+	nfsd_attrs_free(&attrs);
+	return status;
+}
+
+static void nfsd4_file_mark_deleg_written(struct nfs4_file *fi)
+{
+	spin_lock(&fi->fi_lock);
+	if (!list_empty(&fi->fi_delegations)) {
+		struct nfs4_delegation *dp = list_first_entry(&fi->fi_delegations,
+							      struct nfs4_delegation, dl_perfile);
+
+		if (dp->dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG)
+			dp->dl_written = true;
+	}
+	spin_unlock(&fi->fi_lock);
+}
+
+static __be32
+nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+	stateid_t *stateid = &write->wr_stateid;
+	struct nfs4_stid *stid = NULL;
+	struct nfsd_file *nf = NULL;
+	__be32 status = nfs_ok;
+	unsigned long cnt;
+
+	if (write->wr_offset > (u64)OFFSET_MAX ||
+	    write->wr_offset + write->wr_buflen > (u64)OFFSET_MAX)
+		return nfserr_fbig;
+
+	cnt = write->wr_buflen;
+	trace_nfsd_write_start(rqstp, &cstate->current_fh,
+			       write->wr_offset, cnt);
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+						stateid, WR_STATE, &nf, &stid);
+	if (status)
+		return status;
+
+	if (stid) {
+		nfsd4_file_mark_deleg_written(stid->sc_file);
+		nfs4_put_stid(stid);
+	}
+
+	write->wr_how_written = write->wr_stable_how;
+	status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
+				write->wr_offset, &write->wr_payload,
+				&cnt, write->wr_how_written,
+				(__be32 *)write->wr_verifier.data);
+	nfsd_file_put(nf);
+
+	write->wr_bytes_written = cnt;
+	trace_nfsd_write_done(rqstp, &cstate->current_fh,
+			      write->wr_offset, cnt);
+	return status;
+}
+
+static __be32
+nfsd4_verify_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  stateid_t *src_stateid, struct nfsd_file **src,
+		  stateid_t *dst_stateid, struct nfsd_file **dst)
+{
+	__be32 status;
+
+	if (!cstate->save_fh.fh_dentry)
+		return nfserr_nofilehandle;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->save_fh,
+					    src_stateid, RD_STATE, src, NULL);
+	if (status)
+		goto out;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    dst_stateid, WR_STATE, dst, NULL);
+	if (status)
+		goto out_put_src;
+
+	/* fix up for NFS-specific error code */
+	if (!S_ISREG(file_inode((*src)->nf_file)->i_mode) ||
+	    !S_ISREG(file_inode((*dst)->nf_file)->i_mode)) {
+		status = nfserr_wrong_type;
+		goto out_put_dst;
+	}
+
+out:
+	return status;
+out_put_dst:
+	nfsd_file_put(*dst);
+	*dst = NULL;
+out_put_src:
+	nfsd_file_put(*src);
+	*src = NULL;
+	goto out;
+}
+
+static __be32
+nfsd4_clone(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_clone *clone = &u->clone;
+	struct nfsd_file *src, *dst;
+	__be32 status;
+
+	status = nfsd4_verify_copy(rqstp, cstate, &clone->cl_src_stateid, &src,
+				   &clone->cl_dst_stateid, &dst);
+	if (status)
+		goto out;
+
+	status = nfsd4_clone_file_range(rqstp, src, clone->cl_src_pos,
+			dst, clone->cl_dst_pos, clone->cl_count,
+			EX_ISSYNC(cstate->current_fh.fh_export));
+
+	if (!status && (READ_ONCE(dst->nf_file->f_mode) & FMODE_NOCMTIME) != 0)
+		nfsd_update_cmtime_attr(dst->nf_file, 0);
+
+	nfsd_file_put(dst);
+	nfsd_file_put(src);
+out:
+	return status;
+}
+
+/**
+ * nfsd4_has_active_async_copies - Check for ongoing copy operations
+ * @clp: Client to be checked
+ *
+ * NFSD maintains state for async COPY operations after they complete,
+ * and this state remains in the nfs4_client's async_copies list.
+ * Ongoing copies should block the destruction of the nfs4_client, but
+ * completed copies should not.
+ *
+ * Return values:
+ *   %true: At least one active async COPY is ongoing
+ *   %false: No active async COPY operations were found
+ */
+bool nfsd4_has_active_async_copies(struct nfs4_client *clp)
+{
+	struct nfsd4_async_copy *copy;
+	bool result = false;
+
+	spin_lock(&clp->async_lock);
+	list_for_each_entry(copy, &clp->async_copies, copies) {
+		if (!test_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_copy.cp_flags) &&
+		    !test_bit(NFSD4_COPY_F_STOPPED, &copy->cp_copy.cp_flags)) {
+			result = true;
+			break;
+		}
+	}
+	spin_unlock(&clp->async_lock);
+	return result;
+}
+
+/**
+ * nfsd4_async_copy_reaper - Purge completed copies
+ * @nn: Network namespace with possible active copy information
+ */
+void nfsd4_async_copy_reaper(struct nfsd_net *nn)
+{
+	struct nfs4_client *clp;
+	struct nfsd4_async_copy *copy;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&nn->client_lock);
+	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
+		struct list_head *pos, *next;
+
+		spin_lock(&clp->async_lock);
+		list_for_each_safe(pos, next, &clp->async_copies) {
+			copy = list_entry(pos, struct nfsd4_async_copy, copies);
+			if (test_bit(NFSD4_COPY_F_OFFLOAD_DONE,
+				     &copy->cp_copy.cp_flags)) {
+				if (!--copy->cp_ttl) {
+					list_del_init(&copy->copies);
+					list_add(&copy->copies, &reaplist);
+				}
+			}
+		}
+		spin_unlock(&clp->async_lock);
+	}
+	spin_unlock(&nn->client_lock);
+
+	while (!list_empty(&reaplist)) {
+		copy = list_first_entry(&reaplist, struct nfsd4_async_copy,
+					copies);
+		list_del_init(&copy->copies);
+		cleanup_async_copy(copy);
+	}
+}
+
+static void nfs4_put_copy(struct nfsd4_async_copy *copy)
+{
+	if (!refcount_dec_and_test(&copy->refcount))
+		return;
+	/*
+	 * Drop the copy offload stateid's sole reference: removes it from
+	 * cl_stateids and frees the async_copy via nfsd4_free_async_copy_stid().
+	 */
+	nfs4_put_stid(&copy->cp_stid);
+}
+
+static void release_copy_files(struct nfsd4_copy *copy);
+
+static void nfsd4_stop_copy(struct nfsd4_async_copy *copy)
+{
+	trace_nfsd_copy_async_cancel(&copy->cp_copy);
+	/*
+	 * Join the kthread before releasing its resources. The task_struct is
+	 * pinned in nfsd4_copy(), so kthread_stop() is safe even after the
+	 * one-shot kthread has exited. The caller already unlinked the copy,
+	 * so this runs once per copy.
+	 */
+	set_bit(NFSD4_COPY_F_STOPPED, &copy->cp_copy.cp_flags);
+	kthread_stop(copy->copy_task);
+	if (!test_bit(NFSD4_COPY_F_CB_ERROR, &copy->cp_copy.cp_flags))
+		copy->cp_copy.nfserr = nfs_ok;
+	set_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_copy.cp_flags);
+
+	release_copy_files(&copy->cp_copy);
+	nfs4_put_copy(copy);
+}
+
+static struct nfsd4_async_copy *nfsd4_unhash_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_async_copy *copy = NULL;
+
+	spin_lock(&clp->async_lock);
+	if (!list_empty(&clp->async_copies)) {
+		copy = list_first_entry(&clp->async_copies,
+					struct nfsd4_async_copy, copies);
+		refcount_inc(&copy->refcount);
+		/* Pairs with smp_load_acquire() in nfsd4_send_cb_offload(). */
+		smp_store_release(&copy->cp_copy.cp_clp, NULL);
+		if (!list_empty(&copy->copies))
+			list_del_init(&copy->copies);
+	}
+	spin_unlock(&clp->async_lock);
+	return copy;
+}
+
+void nfsd4_shutdown_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_async_copy *copy;
+
+	while ((copy = nfsd4_unhash_copy(clp)) != NULL) {
+		nfsd4_stop_copy(copy);
+		/* Reaper can't reach the unhashed copy; drop its membership ref. */
+		nfs4_put_copy(copy);
+	}
+}
+
+static bool nfsd4_copy_on_sb(const struct nfsd4_copy *copy,
+			     const struct super_block *sb)
+{
+	if (copy->nf_src &&
+	    file_inode(copy->nf_src->nf_file)->i_sb == sb)
+		return true;
+	if (copy->nf_dst &&
+	    file_inode(copy->nf_dst->nf_file)->i_sb == sb)
+		return true;
+	return false;
+}
+
+/**
+ * nfsd4_cancel_copy_by_sb - cancel async copy operations on @sb
+ * @net: net namespace containing the copy operations
+ * @sb: targeted superblock
+ *
+ * Context: Caller must hold nfsd_mutex with NFSD_NET_UP set.  Outside
+ *          that window nn->conf_id_hashtbl is unallocated or freed,
+ *          so the walk would dereference a NULL or dangling pointer.
+ */
+void nfsd4_cancel_copy_by_sb(struct net *net, struct super_block *sb)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfsd4_async_copy *copy, *tmp;
+	struct nfs4_client *clp;
+	unsigned int idhashval;
+	LIST_HEAD(to_cancel);
+
+	lockdep_assert_held(&nfsd_mutex);
+	spin_lock(&nn->client_lock);
+	for (idhashval = 0; idhashval < CLIENT_HASH_SIZE; idhashval++) {
+		struct list_head *head = &nn->conf_id_hashtbl[idhashval];
+
+		list_for_each_entry(clp, head, cl_idhash) {
+			spin_lock(&clp->async_lock);
+			list_for_each_entry_safe(copy, tmp,
+						 &clp->async_copies, copies) {
+				if (nfsd4_copy_on_sb(&copy->cp_copy, sb)) {
+					refcount_inc(&copy->refcount);
+					/*
+					 * Hold a reference on the client while
+					 * nfsd4_stop_copy() runs. Unlike
+					 * nfsd4_unhash_copy(), cp_clp is not
+					 * NULLed here because nfsd4_send_cb_offload()
+					 * needs a valid client to send CB_OFFLOAD.
+					 * That function takes its own reference to
+					 * survive callback flight.
+					 */
+					kref_get(&clp->cl_nfsdfs.cl_ref);
+					copy->cp_copy.nfserr = nfserr_admin_revoked;
+					set_bit(NFSD4_COPY_F_CB_ERROR,
+						&copy->cp_copy.cp_flags);
+					list_move(&copy->copies, &to_cancel);
+				}
+			}
+			spin_unlock(&clp->async_lock);
+		}
+	}
+	spin_unlock(&nn->client_lock);
+
+	list_for_each_entry_safe(copy, tmp, &to_cancel, copies) {
+		struct nfs4_client *clp = copy->cp_copy.cp_clp;
+
+		list_del_init(&copy->copies);
+		nfsd4_stop_copy(copy);
+		/* Reaper can't reach the unlinked copy; drop the membership ref here. */
+		nfs4_put_copy(copy);
+		nfsd4_put_client(clp);
+	}
+}
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+
+extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
+				   struct nfs_fh *src_fh,
+				   nfs4_stateid *stateid);
+extern void nfs42_ssc_close(struct file *filep);
+
+extern void nfs_sb_deactive(struct super_block *sb);
+
+#define NFSD42_INTERSSC_MOUNTOPS "vers=4.2,addr=%s,sec=sys"
+
+/*
+ * setup a work entry in the ssc delayed unmount list.
+ */
+static __be32 nfsd4_ssc_setup_dul(struct nfsd_net *nn, char *ipaddr,
+				  struct nfsd4_ssc_umount_item **nsui,
+				  struct svc_rqst *rqstp)
+{
+	struct nfsd4_ssc_umount_item *ni = NULL;
+	struct nfsd4_ssc_umount_item *work = NULL;
+	struct nfsd4_ssc_umount_item *tmp;
+	DEFINE_WAIT(wait);
+	__be32 status = 0;
+
+	*nsui = NULL;
+	work = kzalloc_obj(*work);
+try_again:
+	spin_lock(&nn->nfsd_ssc_lock);
+	list_for_each_entry_safe(ni, tmp, &nn->nfsd_ssc_mount_list, nsui_list) {
+		if (strncmp(ni->nsui_ipaddr, ipaddr, sizeof(ni->nsui_ipaddr)))
+			continue;
+		/* found a match */
+		if (ni->nsui_busy) {
+			/*  wait - and try again */
+			prepare_to_wait(&nn->nfsd_ssc_waitq, &wait, TASK_IDLE);
+			spin_unlock(&nn->nfsd_ssc_lock);
+
+			/* allow 20secs for mount/unmount for now - revisit */
+			if (svc_thread_should_stop(rqstp) ||
+					(schedule_timeout(20*HZ) == 0)) {
+				finish_wait(&nn->nfsd_ssc_waitq, &wait);
+				kfree(work);
+				return nfserr_jukebox;
+			}
+			finish_wait(&nn->nfsd_ssc_waitq, &wait);
+			goto try_again;
+		}
+		*nsui = ni;
+		refcount_inc(&ni->nsui_refcnt);
+		spin_unlock(&nn->nfsd_ssc_lock);
+		kfree(work);
+
+		/* return vfsmount in (*nsui)->nsui_vfsmount */
+		return 0;
+	}
+	if (work) {
+		strscpy(work->nsui_ipaddr, ipaddr, sizeof(work->nsui_ipaddr));
+		refcount_set(&work->nsui_refcnt, 2);
+		work->nsui_busy = true;
+		list_add_tail(&work->nsui_list, &nn->nfsd_ssc_mount_list);
+		*nsui = work;
+	} else
+		status = nfserr_resource;
+	spin_unlock(&nn->nfsd_ssc_lock);
+	return status;
+}
+
+static void nfsd4_ssc_update_dul(struct nfsd_net *nn,
+				 struct nfsd4_ssc_umount_item *nsui,
+				 struct vfsmount *ss_mnt)
+{
+	spin_lock(&nn->nfsd_ssc_lock);
+	nsui->nsui_vfsmount = ss_mnt;
+	nsui->nsui_busy = false;
+	wake_up_all(&nn->nfsd_ssc_waitq);
+	spin_unlock(&nn->nfsd_ssc_lock);
+}
+
+static void nfsd4_ssc_cancel_dul(struct nfsd_net *nn,
+				 struct nfsd4_ssc_umount_item *nsui)
+{
+	spin_lock(&nn->nfsd_ssc_lock);
+	list_del(&nsui->nsui_list);
+	wake_up_all(&nn->nfsd_ssc_waitq);
+	spin_unlock(&nn->nfsd_ssc_lock);
+	kfree(nsui);
+}
+
+/*
+ * Support one copy source server for now.
+ */
+static __be32
+nfsd4_interssc_connect(struct nl4_server *nss, struct svc_rqst *rqstp,
+		       struct nfsd4_ssc_umount_item **nsui)
+{
+	struct file_system_type *type;
+	struct vfsmount *ss_mnt;
+	struct nfs42_netaddr *naddr;
+	struct sockaddr_storage tmp_addr;
+	size_t tmp_addrlen, match_netid_len = 3;
+	char *startsep = "", *endsep = "", *match_netid = "tcp";
+	char *ipaddr, *dev_name, *raw_data;
+	int len, raw_len;
+	__be32 status = nfserr_inval;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	naddr = &nss->u.nl4_addr;
+	tmp_addrlen = rpc_uaddr2sockaddr(SVC_NET(rqstp), naddr->addr,
+					 naddr->addr_len,
+					 (struct sockaddr *)&tmp_addr,
+					 sizeof(tmp_addr));
+	*nsui = NULL;
+	if (tmp_addrlen == 0)
+		goto out_err;
+
+	if (tmp_addr.ss_family == AF_INET6) {
+		startsep = "[";
+		endsep = "]";
+		match_netid = "tcp6";
+		match_netid_len = 4;
+	}
+
+	if (naddr->netid_len != match_netid_len ||
+		strncmp(naddr->netid, match_netid, naddr->netid_len))
+		goto out_err;
+
+	/* Construct the raw data for the vfs_kern_mount call */
+	len = RPC_MAX_ADDRBUFLEN + 1;
+	ipaddr = kzalloc(len, GFP_KERNEL);
+	if (!ipaddr)
+		goto out_err;
+
+	rpc_ntop((struct sockaddr *)&tmp_addr, ipaddr, len);
+
+	/* 2 for ipv6 endsep and startsep. 3 for ":/" and trailing '/0'*/
+
+	raw_len = strlen(NFSD42_INTERSSC_MOUNTOPS) + strlen(ipaddr);
+	raw_data = kzalloc(raw_len, GFP_KERNEL);
+	if (!raw_data)
+		goto out_free_ipaddr;
+
+	snprintf(raw_data, raw_len, NFSD42_INTERSSC_MOUNTOPS, ipaddr);
+
+	status = nfserr_nodev;
+	type = get_fs_type("nfs");
+	if (!type)
+		goto out_free_rawdata;
+
+	/* Set the server:<export> for the vfs_kern_mount call */
+	dev_name = kzalloc(len + 5, GFP_KERNEL);
+	if (!dev_name)
+		goto out_free_rawdata;
+	snprintf(dev_name, len + 5, "%s%s%s:/", startsep, ipaddr, endsep);
+
+	status = nfsd4_ssc_setup_dul(nn, ipaddr, nsui, rqstp);
+	if (status)
+		goto out_free_devname;
+	if ((*nsui)->nsui_vfsmount)
+		goto out_done;
+
+	/* Use an 'internal' mount: SB_KERNMOUNT -> MNT_INTERNAL */
+	ss_mnt = vfs_kern_mount(type, SB_KERNMOUNT, dev_name, raw_data);
+	module_put(type->owner);
+	if (IS_ERR(ss_mnt)) {
+		status = nfserr_nodev;
+		nfsd4_ssc_cancel_dul(nn, *nsui);
+		goto out_free_devname;
+	}
+	nfsd4_ssc_update_dul(nn, *nsui, ss_mnt);
+out_done:
+	status = 0;
+
+out_free_devname:
+	kfree(dev_name);
+out_free_rawdata:
+	kfree(raw_data);
+out_free_ipaddr:
+	kfree(ipaddr);
+out_err:
+	return status;
+}
+
+/*
+ * Verify COPY destination stateid.
+ *
+ * Connect to the source server with NFSv4.1.
+ * Create the source struct file for nfsd_copy_range.
+ * Called with COPY cstate:
+ *    SAVED_FH: source filehandle
+ *    CURRENT_FH: destination filehandle
+ */
+static __be32
+nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy)
+{
+	struct svc_fh *s_fh = NULL;
+	stateid_t *s_stid = &copy->cp_src_stateid;
+	__be32 status = nfserr_inval;
+
+	/* Verify the destination stateid and set dst struct file*/
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &copy->cp_dst_stateid,
+					    WR_STATE, &copy->nf_dst, NULL);
+	if (status)
+		goto out;
+
+	status = nfsd4_interssc_connect(copy->cp_src, rqstp, &copy->ss_nsui);
+	if (status)
+		goto out;
+
+	s_fh = &cstate->save_fh;
+
+	copy->c_fh.size = s_fh->fh_handle.fh_size;
+	memcpy(copy->c_fh.data, &s_fh->fh_handle.fh_raw, copy->c_fh.size);
+	copy->stateid.seqid = cpu_to_be32(s_stid->si_generation);
+	memcpy(copy->stateid.other, (void *)&s_stid->si_opaque,
+	       sizeof(stateid_opaque_t));
+
+	status = 0;
+out:
+	return status;
+}
+
+static void
+nfsd4_cleanup_inter_ssc(struct nfsd4_ssc_umount_item *nsui, struct file *filp,
+			struct nfsd_file *dst)
+{
+	struct nfsd_net *nn = net_generic(dst->nf_net, nfsd_net_id);
+	long timeout = msecs_to_jiffies(nfsd4_ssc_umount_timeout);
+
+	nfs42_ssc_close(filp);
+	fput(filp);
+
+	spin_lock(&nn->nfsd_ssc_lock);
+	list_del(&nsui->nsui_list);
+	/*
+	 * vfsmount can be shared by multiple exports,
+	 * decrement refcnt. If the count drops to 1 it
+	 * will be unmounted when nsui_expire expires.
+	 */
+	refcount_dec(&nsui->nsui_refcnt);
+	nsui->nsui_expire = jiffies + timeout;
+	list_add_tail(&nsui->nsui_list, &nn->nfsd_ssc_mount_list);
+	spin_unlock(&nn->nfsd_ssc_lock);
+}
+
+#else /* CONFIG_NFSD_V4_2_INTER_SSC */
+
+static __be32
+nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy)
+{
+	return nfserr_inval;
+}
+
+static void
+nfsd4_cleanup_inter_ssc(struct nfsd4_ssc_umount_item *nsui, struct file *filp,
+			struct nfsd_file *dst)
+{
+}
+
+static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
+				   struct nfs_fh *src_fh,
+				   nfs4_stateid *stateid)
+{
+	return NULL;
+}
+#endif /* CONFIG_NFSD_V4_2_INTER_SSC */
+
+static __be32
+nfsd4_setup_intra_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy)
+{
+	return nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
+				 &copy->nf_src, &copy->cp_dst_stateid,
+				 &copy->nf_dst);
+}
+
+static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_cb_offload *cbo =
+		container_of(cb, struct nfsd4_cb_offload, co_cb);
+	struct nfsd4_async_copy *copy =
+		container_of(cbo, struct nfsd4_async_copy, cp_cb_offload);
+
+	set_bit(NFSD4_COPY_F_OFFLOAD_DONE, &copy->cp_copy.cp_flags);
+	/* nfs4_put_copy needs clp; cl_cb_inflight defers free_client. */
+	nfsd4_put_client(cb->cb_clp);
+	/* Drop the copy reference taken in nfsd4_send_cb_offload(). */
+	nfs4_put_copy(copy);
+}
+
+static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
+				 struct rpc_task *task)
+{
+	struct nfsd4_cb_offload *cbo =
+		container_of(cb, struct nfsd4_cb_offload, co_cb);
+
+	trace_nfsd_cb_offload_done(&cbo->co_res.cb_stateid, task);
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		if (cbo->co_retries--) {
+			rpc_delay(task, HZ / 5);
+			return 0;
+		}
+	}
+	nfsd41_cb_destroy_referring_call_list(cb);
+	return 1;
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = {
+	.release = nfsd4_cb_offload_release,
+	.done = nfsd4_cb_offload_done,
+	.opcode = OP_CB_OFFLOAD,
+};
+
+static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
+{
+	copy->cp_res.wr_stable_how =
+		test_bit(NFSD4_COPY_F_COMMITTED, &copy->cp_flags) ?
+			NFS_FILE_SYNC : NFS_UNSTABLE;
+	nfsd4_copy_set_sync(copy, sync);
+}
+
+static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy,
+				     struct file *dst,
+				     struct file *src)
+{
+	errseq_t since;
+	ssize_t bytes_copied = 0;
+	u64 bytes_total = copy->cp_count;
+	u64 src_pos = copy->cp_src_pos;
+	u64 dst_pos = copy->cp_dst_pos;
+	int status;
+	loff_t end;
+
+	/* See RFC 7862 p.67: */
+	if (bytes_total == 0)
+		bytes_total = ULLONG_MAX;
+	since = READ_ONCE(dst->f_wb_err);
+	do {
+		/* Only async copies can be stopped here */
+		if (kthread_should_stop())
+			break;
+		bytes_copied = nfsd_copy_file_range(src, src_pos, dst, dst_pos,
+						    bytes_total);
+		if (bytes_copied <= 0)
+			break;
+		bytes_total -= bytes_copied;
+		copy->cp_res.wr_bytes_written += bytes_copied;
+		src_pos += bytes_copied;
+		dst_pos += bytes_copied;
+	} while (bytes_total > 0 && nfsd4_copy_is_async(copy));
+	/* for a non-zero asynchronous copy do a commit of data */
+	if (nfsd4_copy_is_async(copy) && copy->cp_res.wr_bytes_written > 0) {
+		end = copy->cp_dst_pos + copy->cp_res.wr_bytes_written - 1;
+		status = vfs_fsync_range(dst, copy->cp_dst_pos, end, 0);
+		if (!status)
+			status = filemap_check_wb_err(dst->f_mapping, since);
+		if (!status)
+			set_bit(NFSD4_COPY_F_COMMITTED, &copy->cp_flags);
+		else if (status != -EAGAIN && status != -ESTALE)
+			nfsd_reset_write_verifier(copy->cp_nn);
+	}
+	return bytes_copied;
+}
+
+static __be32 nfsd4_do_copy(struct nfsd4_copy *copy,
+			    struct file *src, struct file *dst,
+			    bool sync)
+{
+	__be32 status;
+	ssize_t bytes;
+
+	bytes = _nfsd_copy_file_range(copy, dst, src);
+
+	/* for async copy, we ignore the error, client can always retry
+	 * to get the error
+	 */
+	if (bytes < 0 && !copy->cp_res.wr_bytes_written)
+		status = nfserrno(bytes);
+	else {
+		nfsd4_init_copy_res(copy, sync);
+		status = nfs_ok;
+	}
+	return status;
+}
+
+static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
+{
+	dst->cp_src_pos = src->cp_src_pos;
+	dst->cp_dst_pos = src->cp_dst_pos;
+	dst->cp_count = src->cp_count;
+	dst->cp_flags = src->cp_flags;
+	memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res));
+	memcpy(&dst->fh, &src->fh, sizeof(src->fh));
+	dst->cp_clp = src->cp_clp;
+	dst->nf_dst = nfsd_file_get(src->nf_dst);
+	/* for inter, nf_src doesn't exist yet */
+	if (!nfsd4_ssc_is_inter(src))
+		dst->nf_src = nfsd_file_get(src->nf_src);
+
+	memcpy(dst->cp_src, src->cp_src, sizeof(struct nl4_server));
+	memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
+	memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
+	dst->ss_nsui = src->ss_nsui;
+}
+
+static void release_copy_files(struct nfsd4_copy *copy)
+{
+	if (copy->nf_src) {
+		nfsd_file_put(copy->nf_src);
+		copy->nf_src = NULL;
+	}
+	if (copy->nf_dst) {
+		nfsd_file_put(copy->nf_dst);
+		copy->nf_dst = NULL;
+	}
+}
+
+/*
+ * Called from the reaper and from nfsd4_copy()'s error path; in both
+ * cases the copy is already unreachable from clp->async_copies.
+ */
+static void cleanup_async_copy(struct nfsd4_async_copy *copy)
+{
+	release_copy_files(&copy->cp_copy);
+	nfs4_put_copy(copy);
+}
+
+static void nfsd4_send_cb_offload(struct nfsd4_async_copy *copy)
+{
+	struct nfsd4_cb_offload *cbo = &copy->cp_cb_offload;
+	struct nfs4_client *clp;
+
+	/*
+	 * Pairs with smp_store_release(&cp_clp) in find_async_copy() and
+	 * nfsd4_unhash_copy(); the set_bit/clear_bit writers are unordered.
+	 * cp_clp is NULL once the copy was canceled; skip the callback, the
+	 * canceling path owns the notification.
+	 */
+	clp = smp_load_acquire(&copy->cp_copy.cp_clp);
+	if (!clp) {
+		set_bit(NFSD4_COPY_F_OFFLOAD_DONE, &copy->cp_copy.cp_flags);
+		return;
+	}
+
+	memcpy(&cbo->co_res, &copy->cp_copy.cp_res, sizeof(copy->cp_copy.cp_res));
+	memcpy(&cbo->co_fh, &copy->cp_copy.fh, sizeof(copy->cp_copy.fh));
+	cbo->co_nfserr = copy->cp_copy.nfserr;
+	cbo->co_retries = 5;
+
+	/*
+	 * Hold the client and the copy across the in-flight callback; co_cb is
+	 * embedded in the copy, so it must outlive the callback. Both are
+	 * dropped in nfsd4_cb_offload_release().
+	 */
+	kref_get(&clp->cl_nfsdfs.cl_ref);
+	refcount_inc(&copy->refcount);
+
+	nfsd4_init_cb(&cbo->co_cb, clp, &nfsd4_cb_offload_ops,
+		      NFSPROC4_CLNT_CB_OFFLOAD);
+	nfsd41_cb_referring_call(&cbo->co_cb, &cbo->co_referring_sessionid,
+				 cbo->co_referring_slotid,
+				 cbo->co_referring_seqno);
+	trace_nfsd_cb_offload(clp, &cbo->co_res.cb_stateid,
+			      &cbo->co_fh, copy->cp_copy.cp_count,
+			      copy->cp_copy.nfserr);
+	nfsd4_try_run_cb(&cbo->co_cb);
+}
+
+/**
+ * nfsd4_do_async_copy - kthread function for background server-side COPY
+ * @data: arguments for COPY operation
+ *
+ * Return values:
+ *   %0: Copy operation is done.
+ */
+static int nfsd4_do_async_copy(void *data)
+{
+	struct nfsd4_async_copy *async = data;
+	struct nfsd4_copy *copy = &async->cp_copy;
+	__be32 nfserr = nfs_ok;
+
+	trace_nfsd_copy_async(copy);
+	if (nfsd4_ssc_is_inter(copy)) {
+		struct file *filp;
+
+		filp = nfs42_ssc_open(copy->ss_nsui->nsui_vfsmount,
+				      &copy->c_fh, &copy->stateid);
+		if (IS_ERR(filp)) {
+			switch (PTR_ERR(filp)) {
+			case -EBADF:
+				nfserr = nfserr_wrong_type;
+				break;
+			default:
+				nfserr = nfserr_offload_denied;
+			}
+			/* ss_mnt will be unmounted by the laundromat */
+			goto do_callback;
+		}
+		nfserr = nfsd4_do_copy(copy, filp, copy->nf_dst->nf_file,
+				       false);
+		nfsd4_cleanup_inter_ssc(copy->ss_nsui, filp, copy->nf_dst);
+	} else {
+		nfserr = nfsd4_do_copy(copy, copy->nf_src->nf_file,
+				       copy->nf_dst->nf_file, false);
+	}
+
+do_callback:
+	if (!test_bit(NFSD4_COPY_F_CB_ERROR, &copy->cp_flags))
+		copy->nfserr = nfserr;
+	/*
+	 * Don't set NFSD4_COPY_F_STOPPED here: it tells a teardown caller it
+	 * may skip kthread_stop(), which would then release nf_dst and the
+	 * client while still in use. Only nfsd4_stop_copy() sets it, after
+	 * joining.
+	 */
+	set_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_flags);
+	trace_nfsd_copy_async_done(copy);
+	atomic_dec(&copy->cp_nn->pending_async_copies);
+	if (copy->cp_res.wr_bytes_written > 0 && copy->attr_update)
+		nfsd_update_cmtime_attr(copy->nf_dst->nf_file, 0);
+	nfsd4_send_cb_offload(async);
+	/* Drop the kthread's reference (taken in nfsd4_copy()); copy may be freed after this. */
+	nfs4_put_copy(async);
+	return 0;
+}
+
+static __be32
+nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfsd4_async_copy *async_copy = NULL;
+	struct nfsd4_copy *copy = &u->copy;
+	struct nfsd42_write_res *result;
+	__be32 status;
+
+	result = &copy->cp_res;
+	nfsd_copy_write_verifier((__be32 *)&result->wr_verifier.data, nn);
+
+	copy->cp_clp = cstate->clp;
+	if (nfsd4_ssc_is_inter(copy)) {
+		trace_nfsd_copy_inter(copy);
+		if (!inter_copy_offload_enable || nfsd4_copy_is_sync(copy)) {
+			status = nfserr_notsupp;
+			goto out;
+		}
+		status = nfsd4_setup_inter_ssc(rqstp, cstate, copy);
+		if (status) {
+			status = nfserr_offload_denied;
+			goto out;
+		}
+	} else {
+		trace_nfsd_copy_intra(copy);
+		status = nfsd4_setup_intra_ssc(rqstp, cstate, copy);
+		if (status)
+			goto out;
+	}
+
+	memcpy(&copy->fh, &cstate->current_fh.fh_handle,
+		sizeof(struct knfsd_fh));
+	if (nfsd4_copy_is_async(copy)) {
+		struct task_struct *task;
+
+		/*
+		 * Allocate the durable async copy. Its offload stateid is a
+		 * first-class nfs4_stid in clp->cl_stateids, returned to the
+		 * client and freed only when the background copy is torn down.
+		 */
+		async_copy = nfs4_alloc_copy_stid(cstate->clp);
+		if (!async_copy)
+			goto out_err;
+		async_copy->cp_copy.cp_nn = nn;
+		INIT_LIST_HEAD(&async_copy->copies);
+		refcount_set(&async_copy->refcount, 1);
+		async_copy->cp_ttl = NFSD_COPY_INITIAL_TTL;
+		/* Arbitrary cap on number of pending async copy operations */
+		if (atomic_inc_return(&nn->pending_async_copies) >
+				(int)rqstp->rq_pool->sp_nrthreads)
+			goto out_dec_async_copy_err;
+		async_copy->cp_copy.cp_src = kmalloc_obj(*async_copy->cp_copy.cp_src);
+		if (!async_copy->cp_copy.cp_src)
+			goto out_dec_async_copy_err;
+		memcpy(&result->cb_stateid, &async_copy->cp_stid.sc_stateid,
+			sizeof(result->cb_stateid));
+		/*
+		 * dup after writing cb_stateid; duplicating first would leave
+		 * the callback stateid zeroed.
+		 */
+		dup_copy_fields(copy, &async_copy->cp_copy);
+		if ((READ_ONCE(copy->nf_dst->nf_file->f_mode) &
+			       FMODE_NOCMTIME) != 0)
+			async_copy->cp_copy.attr_update = true;
+		memcpy(async_copy->cp_cb_offload.co_referring_sessionid.data,
+		       cstate->session->se_sessionid.data,
+		       NFS4_MAX_SESSIONID_LEN);
+		async_copy->cp_cb_offload.co_referring_slotid = cstate->slot->sl_index;
+		async_copy->cp_cb_offload.co_referring_seqno = cstate->slot->sl_seqid;
+		task = kthread_create(nfsd4_do_async_copy, async_copy,
+				      "%s", "copy thread");
+		if (IS_ERR(task))
+			goto out_dec_async_copy_err;
+		/*
+		 * Pin the task_struct so kthread_stop() is safe after this
+		 * one-shot kthread exits. Released by nfs4_put_copy().
+		 */
+		get_task_struct(task);
+		async_copy->copy_task = task;
+		/*
+		 * Take the kthread's ref and wake it before publishing, so the
+		 * publisher touches async_copy no further and teardown can
+		 * drain it.
+		 */
+		refcount_inc(&async_copy->refcount);
+		wake_up_process(async_copy->copy_task);
+		spin_lock(&async_copy->cp_copy.cp_clp->async_lock);
+		list_add(&async_copy->copies,
+				&async_copy->cp_copy.cp_clp->async_copies);
+		spin_unlock(&async_copy->cp_copy.cp_clp->async_lock);
+		status = nfs_ok;
+	} else {
+		status = nfsd4_do_copy(copy, copy->nf_src->nf_file,
+				       copy->nf_dst->nf_file, true);
+		if ((READ_ONCE(copy->nf_dst->nf_file->f_mode) &
+			       FMODE_NOCMTIME) != 0 &&
+				copy->cp_res.wr_bytes_written > 0)
+			nfsd_update_cmtime_attr(copy->nf_dst->nf_file, 0);
+	}
+out:
+	trace_nfsd_copy_done(copy, status);
+	release_copy_files(copy);
+	return status;
+out_dec_async_copy_err:
+	if (async_copy)
+		atomic_dec(&nn->pending_async_copies);
+out_err:
+	if (nfsd4_ssc_is_inter(copy)) {
+		/*
+		 * Source's vfsmount of inter-copy will be unmounted
+		 * by the laundromat. Use copy instead of async_copy
+		 * since async_copy->ss_nsui might not be set yet.
+		 */
+		refcount_dec(&copy->ss_nsui->nsui_refcnt);
+	}
+	if (async_copy)
+		cleanup_async_copy(async_copy);
+	status = nfserr_jukebox;
+	goto out;
+}
+
+static struct nfsd4_async_copy *
+find_async_copy_locked(struct nfs4_client *clp, stateid_t *stateid)
+{
+	struct nfsd4_async_copy *copy;
+
+	lockdep_assert_held(&clp->async_lock);
+
+	list_for_each_entry(copy, &clp->async_copies, copies) {
+		if (memcmp(&copy->cp_stid.sc_stateid, stateid, NFS4_STATEID_SIZE))
+			continue;
+		return copy;
+	}
+	return NULL;
+}
+
+static struct nfsd4_async_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
+{
+	struct nfsd4_async_copy *copy;
+
+	spin_lock(&clp->async_lock);
+	copy = find_async_copy_locked(clp, stateid);
+	if (copy) {
+		refcount_inc(&copy->refcount);
+		/*
+		 * Mirror nfsd4_unhash_copy(): unlink and clear cp_clp under
+		 * async_lock so the reaper can't reach it. Caller drops the
+		 * membership ref after nfsd4_stop_copy().
+		 */
+		smp_store_release(&copy->cp_copy.cp_clp, NULL);
+		if (!list_empty(&copy->copies))
+			list_del_init(&copy->copies);
+	}
+	spin_unlock(&clp->async_lock);
+	return copy;
+}
+
+static __be32
+nfsd4_offload_cancel(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	struct nfsd4_async_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	copy = find_async_copy(clp, &os->stateid);
+	if (!copy) {
+		struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+		return manage_cpntf_state(nn, &os->stateid, clp, NULL);
+	} else {
+		nfsd4_stop_copy(copy);
+		/* find_async_copy() unlinked it from the reaper; drop the membership ref. */
+		nfs4_put_copy(copy);
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_set_netaddr(struct sockaddr *addr, struct nfs42_netaddr *netaddr)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)addr;
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr;
+	unsigned int port;
+	size_t ret_addr, ret_port;
+
+	switch (addr->sa_family) {
+	case AF_INET:
+		port = ntohs(sin->sin_port);
+		sprintf(netaddr->netid, "tcp");
+		netaddr->netid_len = 3;
+		break;
+	case AF_INET6:
+		port = ntohs(sin6->sin6_port);
+		sprintf(netaddr->netid, "tcp6");
+		netaddr->netid_len = 4;
+		break;
+	default:
+		return nfserr_inval;
+	}
+	ret_addr = rpc_ntop(addr, netaddr->addr, sizeof(netaddr->addr));
+	ret_port = snprintf(netaddr->addr + ret_addr,
+			    RPCBIND_MAXUADDRLEN + 1 - ret_addr,
+			    ".%u.%u", port >> 8, port & 0xff);
+	WARN_ON(ret_port >= RPCBIND_MAXUADDRLEN + 1 - ret_addr);
+	netaddr->addr_len = ret_addr + ret_port;
+	return 0;
+}
+
+static __be32
+nfsd4_copy_notify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfs4_stid *stid = NULL;
+	struct nfs4_cpntf_state *cps;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					&cn->cpn_src_stateid, RD_STATE, NULL,
+					&stid);
+	if (status)
+		return status;
+	if (!stid)
+		return nfserr_bad_stateid;
+
+	cn->cpn_lease_time.tv_sec = nn->nfsd4_lease;
+	cn->cpn_lease_time.tv_nsec = 0;
+
+	status = nfserrno(-ENOMEM);
+	/*
+	 * The returned cps is published and fully initialized, and carries an
+	 * extra reference for us; drop it once we are done with it.
+	 */
+	cps = nfs4_alloc_init_cpntf_state(nn, stid);
+	if (!cps)
+		goto out;
+	memcpy(&cn->cpn_cnr_stateid, &cps->cp_stateid.cs_stid, sizeof(stateid_t));
+
+	/* For now, only return one server address in cpn_src, the
+	 * address used by the client to connect to this server.
+	 */
+	cn->cpn_src->nl4_type = NL4_NETADDR;
+	status = nfsd4_set_netaddr((struct sockaddr *)&rqstp->rq_daddr,
+				 &cn->cpn_src->u.nl4_addr);
+	WARN_ON_ONCE(status);
+	/*
+	 * Drop our extra reference. The membership reference keeps the entry
+	 * alive for a later inter-server READ, or until the laundromat reaps it.
+	 */
+	nfs4_put_cpntf_state(nn, cps);
+out:
+	nfs4_put_stid(stid);
+	return status;
+}
+
+static __be32
+nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		struct nfsd4_fallocate *fallocate, int flags)
+{
+	__be32 status;
+	struct nfsd_file *nf;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &fallocate->falloc_stateid,
+					    WR_STATE, &nf, NULL);
+	if (status != nfs_ok)
+		return status;
+
+	status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, nf->nf_file,
+				     fallocate->falloc_offset,
+				     fallocate->falloc_length,
+				     flags);
+	nfsd_file_put(nf);
+	return status;
+}
+
+static __be32
+nfsd4_offload_status(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	__be32 status = nfs_ok;
+	struct nfsd4_async_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	os->completed = false;
+	spin_lock(&clp->async_lock);
+	copy = find_async_copy_locked(clp, &os->stateid);
+	if (copy) {
+		os->count = copy->cp_copy.cp_res.wr_bytes_written;
+		if (test_bit(NFSD4_COPY_F_COMPLETED, &copy->cp_copy.cp_flags)) {
+			os->completed = true;
+			os->status = copy->cp_copy.nfserr;
+		}
+	} else
+		status = nfserr_bad_stateid;
+	spin_unlock(&clp->async_lock);
+
+	return status;
+}
+
+static __be32
+nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	return nfsd4_fallocate(rqstp, cstate, &u->allocate, 0);
+}
+
+static __be32
+nfsd4_deallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		 union nfsd4_op_u *u)
+{
+	return nfsd4_fallocate(rqstp, cstate, &u->deallocate,
+			       FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
+}
+
+static __be32
+nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	int whence;
+	__be32 status;
+	struct nfsd_file *nf;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &seek->seek_stateid,
+					    RD_STATE, &nf, NULL);
+	if (status)
+		return status;
+
+	switch (seek->seek_whence) {
+	case NFS4_CONTENT_DATA:
+		whence = SEEK_DATA;
+		break;
+	case NFS4_CONTENT_HOLE:
+		whence = SEEK_HOLE;
+		break;
+	default:
+		status = nfserr_union_notsupp;
+		goto out;
+	}
+
+	/*
+	 * Note:  This call does change file->f_pos, but nothing in NFSD
+	 *        should ever file->f_pos.
+	 */
+	seek->seek_pos = vfs_llseek(nf->nf_file, seek->seek_offset, whence);
+	if (seek->seek_pos < 0)
+		status = nfserrno(seek->seek_pos);
+	else if (seek->seek_pos >= i_size_read(file_inode(nf->nf_file)))
+		seek->seek_eof = true;
+
+out:
+	nfsd_file_put(nf);
+	return status;
+}
+
+/* This routine never returns NFS_OK!  If there are no other errors, it
+ * will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the
+ * attributes matched.  VERIFY is implemented by mapping NFSERR_SAME
+ * to NFS_OK after the call; NVERIFY by mapping NFSERR_NOT_SAME to NFS_OK.
+ */
+static __be32
+_nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     struct nfsd4_verify *verify)
+{
+	__be32 *buf, *p;
+	int count;
+	__be32 status;
+
+	status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+	if (status)
+		return status;
+
+	status = check_attr_support(cstate, verify->ve_bmval, NULL);
+	if (status)
+		return status;
+
+	if ((verify->ve_bmval[0] & FATTR4_WORD0_RDATTR_ERROR)
+	    || (verify->ve_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1))
+		return nfserr_inval;
+	if (verify->ve_attrlen & 3)
+		return nfserr_inval;
+
+	/* The POSIX draft ACLs cannot be tested via (N)VERIFY. */
+	if (verify->ve_bmval[2] & (FATTR4_WORD2_POSIX_DEFAULT_ACL |
+					FATTR4_WORD2_POSIX_ACCESS_ACL))
+		return nfserr_inval;
+
+	/* count in words:
+	 *   bitmap_len(1) + bitmap(2) + attr_len(1) = 4
+	 */
+	count = 4 + (verify->ve_attrlen >> 2);
+	buf = kmalloc(count << 2, GFP_KERNEL);
+	if (!buf)
+		return nfserr_jukebox;
+
+	p = buf;
+	status = nfsd4_encode_fattr_to_buf(&p, count, &cstate->current_fh,
+				    cstate->current_fh.fh_export,
+				    cstate->current_fh.fh_dentry,
+				    verify->ve_bmval,
+				    rqstp, 0);
+	/*
+	 * If nfsd4_encode_fattr() ran out of space, assume that's because
+	 * the attributes are longer (hence different) than those given:
+	 */
+	if (status == nfserr_resource)
+		status = nfserr_not_same;
+	if (status)
+		goto out_kfree;
+
+	/* skip bitmap */
+	p = buf + 1 + ntohl(buf[0]);
+	status = nfserr_not_same;
+	if (ntohl(*p++) != verify->ve_attrlen)
+		goto out_kfree;
+	if (!memcmp(p, verify->ve_attrval, verify->ve_attrlen))
+		status = nfserr_same;
+
+out_kfree:
+	kfree(buf);
+	return status;
+}
+
+static __be32
+nfsd4_nverify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	__be32 status;
+
+	status = _nfsd4_verify(rqstp, cstate, &u->verify);
+	return status == nfserr_not_same ? nfs_ok : status;
+}
+
+static __be32
+nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	__be32 status;
+
+	status = _nfsd4_verify(rqstp, cstate, &u->nverify);
+	return status == nfserr_same ? nfs_ok : status;
+}
+
+#define SUPPORTED_NOTIFY_MASK	(BIT(NOTIFY4_CHANGE_DIR_ATTRS) |	\
+				 BIT(NOTIFY4_REMOVE_ENTRY) |		\
+				 BIT(NOTIFY4_ADD_ENTRY) |		\
+				 BIT(NOTIFY4_RENAME_ENTRY) |		\
+				 BIT(NOTIFY4_GFLAG_EXTEND))
+
+static __be32
+nfsd4_get_dir_delegation(struct svc_rqst *rqstp,
+			 struct nfsd4_compound_state *cstate,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	u32 requested = gdd->gdda_notification_types[0];
+	struct nfs4_delegation *dd;
+	struct nfsd_file *nf;
+	__be32 status;
+
+	status = nfsd_file_acquire_dir(rqstp, &cstate->current_fh, &nf);
+	if (status != nfs_ok)
+		return status;
+
+	/*
+	 * Offer no notifications to an order-aware client. RFC8881bis section
+	 * 16.2.13 defines order-aware as NOTIFY4_CFLAG_ORDER being set or
+	 * NOTIFY4_GFLAG_EXTEND being reset. Such a client expects cookie and
+	 * previous-entry information with its notifications (e.g. 27.4.5), and
+	 * nfsd does not track or emit directory offset information. Per
+	 * 16.2.11.3 the alternative would be to recall the delegation, so it's
+	 * simpler to just decline the notifications here.
+	 */
+	if (!(requested & BIT(NOTIFY4_GFLAG_EXTEND)) ||
+	    (requested & BIT(NOTIFY4_CFLAG_ORDER)))
+		requested = 0;
+
+	gdd->gddr_notification[0] = requested & SUPPORTED_NOTIFY_MASK;
+
+	/*
+	 * RFC 8881, section 18.39.3 says:
+	 *
+	 * "The server may refuse to grant the delegation. In that case, the
+	 *  server will return NFS4ERR_DIRDELEG_UNAVAIL."
+	 *
+	 * This is sub-optimal, since it means that the server would need to
+	 * abort compound processing just because the delegation wasn't
+	 * available. RFC8881bis should change this to allow the server to
+	 * return NFS4_OK with a non-fatal status of GDD4_UNAVAIL in this
+	 * situation.
+	 */
+	dd = nfsd_get_dir_deleg(cstate, gdd, nf);
+	nfsd_file_put(nf);
+	if (IS_ERR(dd)) {
+		gdd->gddrnf_status = GDD4_UNAVAIL;
+		return nfs_ok;
+	}
+
+	gdd->gddrnf_status = GDD4_OK;
+	memcpy(&gdd->gddr_stateid, &dd->dl_stid.sc_stateid, sizeof(gdd->gddr_stateid));
+	gdd->gddr_child_attributes[0] = dd->dl_child_attrs[0];
+	gdd->gddr_child_attributes[1] = dd->dl_child_attrs[1];
+	gdd->gddr_dir_attributes[0] = dd->dl_dir_attrs[0];
+	gdd->gddr_dir_attributes[1] = dd->dl_dir_attrs[1];
+	nfs4_put_stid(&dd->dl_stid);
+	return nfs_ok;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static const struct nfsd4_layout_ops *
+nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)
+{
+	if (!exp->ex_layout_types) {
+		dprintk("%s: export does not support pNFS\n", __func__);
+		return NULL;
+	}
+
+	if (layout_type >= LAYOUT_TYPE_MAX ||
+	    !(exp->ex_layout_types & (1 << layout_type))) {
+		dprintk("%s: layout type %d not supported\n",
+			__func__, layout_type);
+		return NULL;
+	}
+
+	return nfsd4_layout_ops[layout_type];
+}
+
+static __be32
+nfsd4_getdeviceinfo(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdp = &u->getdeviceinfo;
+	const struct nfsd4_layout_ops *ops;
+	struct nfsd4_deviceid_map *map;
+	struct svc_export *exp;
+	__be32 nfserr;
+
+	dprintk("%s: layout_type %u dev_id [0x%llx:0x%x] maxcnt %u\n",
+	       __func__,
+	       gdp->gd_layout_type,
+	       gdp->gd_devid.fsid_idx, gdp->gd_devid.generation,
+	       gdp->gd_maxcount);
+
+	map = nfsd4_find_devid_map(gdp->gd_devid.fsid_idx);
+	if (!map) {
+		dprintk("%s: couldn't find device ID to export mapping!\n",
+			__func__);
+		return nfserr_noent;
+	}
+
+	exp = rqst_exp_find(&rqstp->rq_chandle, SVC_NET(rqstp),
+			    rqstp->rq_client, rqstp->rq_gssclient,
+			    map->fsid_type, map->fsid);
+	if (IS_ERR(exp)) {
+		dprintk("%s: could not find device id\n", __func__);
+		return nfserr_noent;
+	}
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(exp, gdp->gd_layout_type);
+	if (!ops)
+		goto out;
+
+	nfserr = nfs_ok;
+	if (gdp->gd_maxcount != 0) {
+		nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb,
+				rqstp, cstate->clp, gdp);
+	}
+
+	gdp->gd_notify_types &= ops->notify_types;
+out:
+	exp_put(exp);
+	return nfserr;
+}
+
+static void
+nfsd4_getdeviceinfo_release(union nfsd4_op_u *u)
+{
+	kfree(u->getdeviceinfo.gd_device);
+}
+
+static __be32
+nfsd4_layoutget(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	const struct nfsd4_layout_ops *ops;
+	struct nfs4_layout_stateid *ls;
+	__be32 nfserr;
+	int accmode = NFSD_MAY_READ_IF_EXEC | NFSD_MAY_OWNER_OVERRIDE;
+
+	switch (lgp->lg_seg.iomode) {
+	case IOMODE_READ:
+		accmode |= NFSD_MAY_READ;
+		break;
+	case IOMODE_RW:
+		accmode |= NFSD_MAY_READ | NFSD_MAY_WRITE;
+		break;
+	default:
+		dprintk("%s: invalid iomode %d\n",
+			__func__, lgp->lg_seg.iomode);
+		nfserr = nfserr_badiomode;
+		goto out;
+	}
+
+	nfserr = fh_verify(rqstp, current_fh, 0, accmode);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(current_fh->fh_export, lgp->lg_layout_type);
+	if (!ops)
+		goto out;
+
+	/*
+	 * Verify minlength and range as per RFC5661:
+	 *  o  If loga_length is less than loga_minlength,
+	 *     the metadata server MUST return NFS4ERR_INVAL.
+	 *  o  If the sum of loga_offset and loga_minlength exceeds
+	 *     NFS4_UINT64_MAX, and loga_minlength is not
+	 *     NFS4_UINT64_MAX, the error NFS4ERR_INVAL MUST result.
+	 *  o  If the sum of loga_offset and loga_length exceeds
+	 *     NFS4_UINT64_MAX, and loga_length is not NFS4_UINT64_MAX,
+	 *     the error NFS4ERR_INVAL MUST result.
+	 */
+	nfserr = nfserr_inval;
+	if (lgp->lg_seg.length < lgp->lg_minlength ||
+	    (lgp->lg_minlength != NFS4_MAX_UINT64 &&
+	     lgp->lg_minlength > NFS4_MAX_UINT64 - lgp->lg_seg.offset) ||
+	    (lgp->lg_seg.length != NFS4_MAX_UINT64 &&
+	     lgp->lg_seg.length > NFS4_MAX_UINT64 - lgp->lg_seg.offset))
+		goto out;
+	if (lgp->lg_seg.length == 0)
+		goto out;
+
+	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lgp->lg_sid,
+						true, lgp->lg_layout_type, &ls);
+	if (nfserr) {
+		trace_nfsd_layout_get_lookup_fail(&lgp->lg_sid);
+		goto out;
+	}
+
+	nfserr = nfserr_recallconflict;
+	if (atomic_read(&ls->ls_stid.sc_file->fi_lo_recalls))
+		goto out_put_stid;
+
+	nfserr = ops->proc_layoutget(rqstp, d_inode(current_fh->fh_dentry),
+				     current_fh, lgp);
+	if (nfserr)
+		goto out_put_stid;
+
+	nfserr = nfsd4_insert_layout(lgp, ls);
+
+out_put_stid:
+	mutex_unlock(&ls->ls_mutex);
+	nfs4_put_stid(&ls->ls_stid);
+out:
+	return nfserr;
+}
+
+static void
+nfsd4_layoutget_release(union nfsd4_op_u *u)
+{
+	kfree(u->layoutget.lg_content);
+}
+
+static __be32
+nfsd4_layoutcommit(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	const struct nfsd4_layout_seg *seg = &lcp->lc_seg;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	const struct nfsd4_layout_ops *ops;
+	struct inode *inode;
+	struct nfs4_layout_stateid *ls;
+	__be32 nfserr;
+
+	nfserr = fh_verify(rqstp, current_fh, 0,
+			   NFSD_MAY_WRITE | NFSD_MAY_OWNER_OVERRIDE);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(current_fh->fh_export, lcp->lc_layout_type);
+	if (!ops)
+		goto out;
+	inode = d_inode(current_fh->fh_dentry);
+
+	lcp->lc_size_chg = false;
+	if (lcp->lc_newoffset) {
+		loff_t new_size = lcp->lc_last_wr + 1;
+
+		nfserr = nfserr_inval;
+		if (new_size <= seg->offset)
+			goto out;
+		if (new_size > seg->offset + seg->length)
+			goto out;
+
+		if (new_size > i_size_read(inode)) {
+			lcp->lc_size_chg = true;
+			lcp->lc_newsize = new_size;
+		}
+	}
+
+	nfserr = nfserr_grace;
+	if (locks_in_grace(net) && !lcp->lc_reclaim)
+		goto out;
+	nfserr = nfserr_no_grace;
+	if (!locks_in_grace(net) && lcp->lc_reclaim)
+		goto out;
+
+	if (!lcp->lc_reclaim) {
+		nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate,
+				&lcp->lc_sid, false, lcp->lc_layout_type, &ls);
+		if (nfserr) {
+			trace_nfsd_layout_commit_lookup_fail(&lcp->lc_sid);
+			/* fixup error code as per RFC5661 */
+			if (nfserr == nfserr_bad_stateid)
+				nfserr = nfserr_badlayout;
+			goto out;
+		}
+
+		/* LAYOUTCOMMIT does not require any serialization */
+		mutex_unlock(&ls->ls_mutex);
+	}
+
+	nfserr = ops->proc_layoutcommit(inode, rqstp, lcp);
+
+	if (!lcp->lc_reclaim) {
+		nfsd4_file_mark_deleg_written(ls->ls_stid.sc_file);
+		nfs4_put_stid(&ls->ls_stid);
+	}
+out:
+	return nfserr;
+}
+
+static __be32
+nfsd4_layoutreturn(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	__be32 nfserr;
+
+	nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_NOP);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	if (!nfsd4_layout_verify(current_fh->fh_export, lrp->lr_layout_type))
+		goto out;
+
+	switch (lrp->lr_seg.iomode) {
+	case IOMODE_READ:
+	case IOMODE_RW:
+	case IOMODE_ANY:
+		break;
+	default:
+		dprintk("%s: invalid iomode %d\n", __func__,
+			lrp->lr_seg.iomode);
+		nfserr = nfserr_inval;
+		goto out;
+	}
+
+	switch (lrp->lr_return_type) {
+	case RETURN_FILE:
+		nfserr = nfsd4_return_file_layouts(rqstp, cstate, lrp);
+		break;
+	case RETURN_FSID:
+	case RETURN_ALL:
+		nfserr = nfsd4_return_client_layouts(rqstp, cstate, lrp);
+		break;
+	default:
+		dprintk("%s: invalid return_type %d\n", __func__,
+			lrp->lr_return_type);
+		nfserr = nfserr_inval;
+		break;
+	}
+out:
+	return nfserr;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_getxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+
+	return nfsd_getxattr(rqstp, &cstate->current_fh,
+			     getxattr->getxa_name, &getxattr->getxa_buf,
+			     &getxattr->getxa_len);
+}
+
+static __be32
+nfsd4_setxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	__be32 ret;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	ret = nfsd_setxattr(rqstp, &cstate->current_fh, setxattr->setxa_name,
+			    setxattr->setxa_buf, setxattr->setxa_len,
+			    setxattr->setxa_flags);
+
+	if (!ret)
+		set_change_info(&setxattr->setxa_cinfo, &cstate->current_fh);
+
+	return ret;
+}
+
+static __be32
+nfsd4_listxattrs(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	/*
+	 * Get the entire list, then copy out only the user attributes
+	 * in the encode function.
+	 */
+	return nfsd_listxattr(rqstp, &cstate->current_fh,
+			     &u->listxattrs.lsxa_buf, &u->listxattrs.lsxa_len);
+}
+
+static __be32
+nfsd4_removexattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	__be32 ret;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	ret = nfsd_removexattr(rqstp, &cstate->current_fh,
+	    removexattr->rmxa_name);
+
+	if (!ret)
+		set_change_info(&removexattr->rmxa_cinfo, &cstate->current_fh);
+
+	return ret;
+}
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd4_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+static inline void nfsd4_increment_op_stats(struct nfsd_net *nn, u32 opnum)
+{
+	if (opnum >= FIRST_NFS4_OP && opnum <= LAST_NFS4_OP)
+		percpu_counter_inc(&nn->counter[NFSD_STATS_NFS4_OP(opnum)]);
+}
+
+static const struct nfsd4_operation nfsd4_ops[];
+
+static const char *nfsd4_op_name(unsigned opnum);
+
+/*
+ * Enforce NFSv4.1 COMPOUND ordering rules:
+ *
+ * Also note, enforced elsewhere:
+ *	- SEQUENCE other than as first op results in
+ *	  NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
+ *	- BIND_CONN_TO_SESSION must be the only op in its compound.
+ *	  (Enforced in nfsd4_bind_conn_to_session().)
+ *	- DESTROY_SESSION must be the final operation in a compound, if
+ *	  sessionid's in SEQUENCE and DESTROY_SESSION are the same.
+ *	  (Enforced in nfsd4_destroy_session().)
+ */
+static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
+{
+	struct nfsd4_op *first_op = &args->ops[0];
+
+	/* These ordering requirements don't apply to NFSv4.0: */
+	if (args->minorversion == 0)
+		return nfs_ok;
+	/* This is weird, but OK, not our problem: */
+	if (args->opcnt == 0)
+		return nfs_ok;
+	if (first_op->status == nfserr_op_illegal)
+		return nfs_ok;
+	if (!(nfsd4_ops[first_op->opnum].op_flags & ALLOWED_AS_FIRST_OP))
+		return nfserr_op_not_in_session;
+	if (first_op->opnum == OP_SEQUENCE)
+		return nfs_ok;
+	/*
+	 * So first_op is something allowed outside a session, like
+	 * EXCHANGE_ID; but then it has to be the only op in the
+	 * compound:
+	 */
+	if (args->opcnt != 1)
+		return nfserr_not_only_op;
+	return nfs_ok;
+}
+
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
+{
+	return &nfsd4_ops[op->opnum];
+}
+
+bool nfsd4_cache_this_op(struct nfsd4_op *op)
+{
+	if (op->opnum == OP_ILLEGAL)
+		return false;
+	return OPDESC(op)->op_flags & OP_CACHEME;
+}
+
+static bool need_wrongsec_check(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+	struct nfsd4_op *this = &argp->ops[resp->opcnt - 1];
+	struct nfsd4_op *next = &argp->ops[resp->opcnt];
+	const struct nfsd4_operation *thisd = OPDESC(this);
+	const struct nfsd4_operation *nextd;
+
+	/*
+	 * Most ops check wronsec on our own; only the putfh-like ops
+	 * have special rules.
+	 */
+	if (!(thisd->op_flags & OP_IS_PUTFH_LIKE))
+		return false;
+	/*
+	 * rfc 5661 2.6.3.1.1.6: don't bother erroring out a
+	 * put-filehandle operation if we're not going to use the
+	 * result:
+	 */
+	if (argp->opcnt == resp->opcnt)
+		return false;
+	if (next->opnum == OP_ILLEGAL)
+		return false;
+	nextd = OPDESC(next);
+	/*
+	 * Rest of 2.6.3.1.1: certain operations will return WRONGSEC
+	 * errors themselves as necessary; others should check for them
+	 * now:
+	 */
+	return !(nextd->op_flags & OP_HANDLES_WRONGSEC);
+}
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+static void
+check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
+{
+	struct nfsd4_op	*op, *current_op = NULL, *saved_op = NULL;
+	struct nfsd4_copy *copy;
+	struct nfsd4_putfh *putfh;
+	int i;
+
+	/* traverse all operation and if it's a COPY compound, mark the
+	 * source filehandle to skip verification
+	 */
+	for (i = 0; i < args->opcnt; i++) {
+		op = &args->ops[i];
+		if (op->opnum == OP_PUTFH)
+			current_op = op;
+		else if (op->opnum == OP_SAVEFH)
+			saved_op = current_op;
+		else if (op->opnum == OP_RESTOREFH)
+			current_op = saved_op;
+		else if (op->opnum == OP_COPY) {
+			copy = (struct nfsd4_copy *)&op->u;
+			if (!saved_op) {
+				op->status = nfserr_nofilehandle;
+				return;
+			}
+			putfh = (struct nfsd4_putfh *)&saved_op->u;
+			if (nfsd4_ssc_is_inter(copy))
+				putfh->no_verify = true;
+		}
+	}
+}
+#else
+static void
+check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
+{
+}
+#endif
+
+/*
+ * COMPOUND call.
+ */
+static __be32
+nfsd4_proc_compound(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_op	*op;
+	struct nfsd4_compound_state *cstate = &resp->cstate;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	struct svc_fh *save_fh = &cstate->save_fh;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfsd_thread_local_info *ntli = rqstp->rq_private;
+	__be32		status;
+
+	resp->xdr = &rqstp->rq_res_stream;
+	resp->statusp = resp->xdr->p;
+
+	/* reserve space for: NFS status code */
+	xdr_reserve_space(resp->xdr, XDR_UNIT);
+
+	/* reserve space for: taglen, tag, and opcnt */
+	xdr_reserve_space(resp->xdr, XDR_UNIT * 2 + args->taglen);
+	resp->taglen = args->taglen;
+	resp->tag = args->tag;
+	resp->rqstp = rqstp;
+	cstate->minorversion = args->minorversion;
+	fh_init(current_fh, NFS4_FHSIZE);
+	fh_init(save_fh, NFS4_FHSIZE);
+	/*
+	 * Don't use the deferral mechanism for NFSv4; compounds make it
+	 * too hard to avoid non-idempotency problems.
+	 */
+	clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+
+	/*
+	 * According to RFC3010, this takes precedence over all other errors.
+	 */
+	status = nfserr_minor_vers_mismatch;
+	if (nfsd_minorversion(nn, args->minorversion, NFSD_TEST) <= 0)
+		goto out;
+
+	status = nfs41_check_op_ordering(args);
+	if (status) {
+		op = &args->ops[0];
+		op->status = status;
+		resp->opcnt = 1;
+		goto encode_op;
+	}
+	check_if_stalefh_allowed(args);
+
+	ntli->ntli_lease_breaker = &cstate->clp;
+
+	trace_nfsd_compound(rqstp, args->tag, args->taglen, args->client_opcnt);
+	while (!status && resp->opcnt < args->opcnt) {
+		op = &args->ops[resp->opcnt++];
+
+		if (unlikely(resp->opcnt == NFSD_MAX_OPS_PER_COMPOUND)) {
+			/* If there are still more operations to process,
+			 * stop here and report NFS4ERR_RESOURCE. */
+			if (cstate->minorversion == 0 &&
+			    args->client_opcnt > resp->opcnt) {
+				op->status = nfserr_resource;
+				goto encode_op;
+			}
+		}
+
+		/*
+		 * The XDR decode routines may have pre-set op->status;
+		 * for example, if there is a miscellaneous XDR error
+		 * it will be set to nfserr_bad_xdr.
+		 */
+		if (op->status) {
+			if (op->opnum == OP_OPEN)
+				op->status = nfsd4_open_omfg(rqstp, cstate, op);
+			goto encode_op;
+		}
+		if (!current_fh->fh_dentry) {
+			if (HAS_FH_FLAG(current_fh, NFSD4_FH_FOREIGN)) {
+				/*
+				 * FOREIGN fh from inter-SSC PUTFH: only
+				 * SAVEFH may proceed with a NULL fh_dentry.
+				 * Per RFC 7862 S15.2.3, validation of a
+				 * foreign fh is deferred to the operation
+				 * that consumes it, and NFS4ERR_STALE is
+				 * returned at that point.
+				 */
+				if (op->opnum != OP_SAVEFH &&
+				    !(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
+					op->status = nfserr_stale;
+					goto encode_op;
+				}
+			} else if (!(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
+				op->status = nfserr_nofilehandle;
+				goto encode_op;
+			}
+		} else if (current_fh->fh_export &&
+			   current_fh->fh_export->ex_fslocs.migrated &&
+			  !(op->opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
+			op->status = nfserr_moved;
+			goto encode_op;
+		}
+
+		fh_clear_pre_post_attrs(current_fh);
+
+		/* If op is non-idempotent */
+		if (op->opdesc->op_flags & OP_MODIFIES_SOMETHING) {
+			/*
+			 * Don't execute this op if we couldn't encode a
+			 * successful reply:
+			 */
+			u32 plen = op->opdesc->op_rsize_bop(rqstp, op);
+			/*
+			 * Plus if there's another operation, make sure
+			 * we'll have space to at least encode an error:
+			 */
+			if (resp->opcnt < args->opcnt)
+				plen += COMPOUND_ERR_SLACK_SPACE;
+			op->status = nfsd4_check_resp_size(resp, plen);
+		}
+
+		if (op->status)
+			goto encode_op;
+
+		if (op->opdesc->op_get_currentstateid)
+			op->opdesc->op_get_currentstateid(cstate, &op->u);
+		op->status = op->opdesc->op_func(rqstp, cstate, &op->u);
+		trace_nfsd_compound_op_err(rqstp, op->opnum, op->status);
+
+		/* Only from SEQUENCE */
+		if (cstate->status == nfserr_replay_cache) {
+			dprintk("%s NFS4.1 replay from cache\n", __func__);
+			status = op->status;
+			goto out;
+		}
+		if (!op->status) {
+			if (op->opdesc->op_set_currentstateid)
+				op->opdesc->op_set_currentstateid(cstate, &op->u);
+
+			if (op->opdesc->op_flags & OP_CLEAR_STATEID)
+				clear_current_stateid(cstate);
+
+			if (current_fh->fh_export &&
+					need_wrongsec_check(rqstp))
+				op->status = check_nfsd_access(current_fh->fh_export, rqstp, false);
+		}
+encode_op:
+		if (op->status == nfserr_replay_me) {
+			op->replay = &cstate->replay_owner->so_replay;
+			nfsd4_encode_replay(resp->xdr, op);
+			status = op->status = op->replay->rp_status;
+		} else {
+			nfsd4_encode_operation(resp, op);
+			status = op->status;
+		}
+
+		if (op->opdesc && op->opdesc->op_release)
+			op->opdesc->op_release(&op->u);
+
+		trace_nfsd_compound_status(args->client_opcnt, resp->opcnt,
+					   status, nfsd4_op_name(op->opnum));
+
+		nfsd4_cstate_clear_replay(cstate);
+		nfsd4_increment_op_stats(nn, op->opnum);
+	}
+
+	fh_put(current_fh);
+	fh_put(save_fh);
+	BUG_ON(cstate->replay_owner);
+out:
+	cstate->status = status;
+	return rpc_success;
+}
+
+#define op_encode_hdr_size		(2)
+#define op_encode_stateid_maxsz		(XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define op_encode_verifier_maxsz	(XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define op_encode_change_info_maxsz	(5)
+#define nfs4_fattr_bitmap_maxsz		(4)
+
+/* We'll fall back on returning no lockowner if run out of space: */
+#define op_encode_lockowner_maxsz	(0)
+#define op_encode_lock_denied_maxsz	(8 + op_encode_lockowner_maxsz)
+
+#define nfs4_owner_maxsz		(1 + XDR_QUADLEN(IDMAP_NAMESZ))
+
+#define op_encode_ace_maxsz		(3 + nfs4_owner_maxsz)
+#define op_encode_delegation_maxsz	(1 + op_encode_stateid_maxsz + 1 + \
+					 op_encode_ace_maxsz)
+
+#define op_encode_channel_attrs_maxsz	(6 + 1 + 1)
+
+/*
+ * The _rsize() helpers are invoked by the NFSv4 COMPOUND decoder, which
+ * is called before sunrpc sets rq_res.buflen. Thus we have to compute
+ * the maximum payload size here, based on transport limits and the size
+ * of the remaining space in the rq_pages array.
+ */
+static u32 nfsd4_max_payload(const struct svc_rqst *rqstp)
+{
+	u32 buflen;
+
+	buflen = (rqstp->rq_page_end - rqstp->rq_next_page) * PAGE_SIZE;
+	buflen -= rqstp->rq_auth_slack;
+	buflen -= rqstp->rq_res.head[0].iov_len;
+	return min_t(u32, buflen, svc_max_payload(rqstp));
+}
+
+static u32 nfsd4_only_status_rsize(const struct svc_rqst *rqstp,
+				   const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size) * sizeof(__be32);
+}
+
+static u32 nfsd4_status_stateid_rsize(const struct svc_rqst *rqstp,
+				      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_stateid_maxsz)* sizeof(__be32);
+}
+
+static u32 nfsd4_access_rsize(const struct svc_rqst *rqstp,
+			      const struct nfsd4_op *op)
+{
+	/* ac_supported, ac_resp_access */
+	return (op_encode_hdr_size + 2)* sizeof(__be32);
+}
+
+static u32 nfsd4_commit_rsize(const struct svc_rqst *rqstp,
+			      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_create_rsize(const struct svc_rqst *rqstp,
+			      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz
+		+ nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+/*
+ * Note since this is an idempotent operation we won't insist on failing
+ * the op prematurely if the estimate is too large.  We may turn off splice
+ * reads unnecessarily.
+ */
+static u32 nfsd4_getattr_rsize(const struct svc_rqst *rqstp,
+			       const struct nfsd4_op *op)
+{
+	const u32 *bmap = op->u.getattr.ga_bmval;
+	u32 bmap0 = bmap[0], bmap1 = bmap[1], bmap2 = bmap[2];
+	u32 ret = 0;
+
+	if (bmap0 & FATTR4_WORD0_ACL)
+		return nfsd4_max_payload(rqstp);
+	if (bmap0 & FATTR4_WORD0_FS_LOCATIONS)
+		return nfsd4_max_payload(rqstp);
+
+	if (bmap1 & FATTR4_WORD1_OWNER) {
+		ret += IDMAP_NAMESZ + 4;
+		bmap1 &= ~FATTR4_WORD1_OWNER;
+	}
+	if (bmap1 & FATTR4_WORD1_OWNER_GROUP) {
+		ret += IDMAP_NAMESZ + 4;
+		bmap1 &= ~FATTR4_WORD1_OWNER_GROUP;
+	}
+	if (bmap0 & FATTR4_WORD0_FILEHANDLE) {
+		ret += NFS4_FHSIZE + 4;
+		bmap0 &= ~FATTR4_WORD0_FILEHANDLE;
+	}
+	if (bmap2 & FATTR4_WORD2_SECURITY_LABEL) {
+		ret += NFS4_MAXLABELLEN + 12;
+		bmap2 &= ~FATTR4_WORD2_SECURITY_LABEL;
+	}
+	/*
+	 * Largest of remaining attributes are 16 bytes (e.g.,
+	 * supported_attributes)
+	 */
+	ret += 16 * (hweight32(bmap0) + hweight32(bmap1) + hweight32(bmap2));
+	/* bitmask, length */
+	ret += 20;
+	return ret;
+}
+
+static u32 nfsd4_getfh_rsize(const struct svc_rqst *rqstp,
+			     const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1) * sizeof(__be32) + NFS4_FHSIZE;
+}
+
+static u32 nfsd4_link_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+static u32 nfsd4_lock_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_lock_denied_maxsz)
+		* sizeof(__be32);
+}
+
+static u32 nfsd4_open_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_stateid_maxsz
+		+ op_encode_change_info_maxsz + 1
+		+ nfs4_fattr_bitmap_maxsz
+		+ op_encode_delegation_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_read_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp));
+
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static u32 nfsd4_read_plus_rsize(const struct svc_rqst *rqstp,
+				 const struct nfsd4_op *op)
+{
+	u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp));
+	/*
+	 * If we detect that the file changed during hole encoding, then we
+	 * recover by encoding the remaining reply as data. This means we need
+	 * to set aside enough room to encode two data segments.
+	 */
+	u32 seg_len = 2 * (1 + 2 + 1);
+
+	return (op_encode_hdr_size + 2 + seg_len + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static u32 nfsd4_readdir_rsize(const struct svc_rqst *rqstp,
+			       const struct nfsd4_op *op)
+{
+	u32 rlen = min(op->u.readdir.rd_maxcount, nfsd4_max_payload(rqstp));
+
+	return (op_encode_hdr_size + op_encode_verifier_maxsz +
+		XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static u32 nfsd4_readlink_rsize(const struct svc_rqst *rqstp,
+				const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1) * sizeof(__be32) + PAGE_SIZE;
+}
+
+static u32 nfsd4_remove_rsize(const struct svc_rqst *rqstp,
+			      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+static u32 nfsd4_rename_rsize(const struct svc_rqst *rqstp,
+			      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz
+		+ op_encode_change_info_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_sequence_rsize(const struct svc_rqst *rqstp,
+				const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size
+		+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5) * sizeof(__be32);
+}
+
+static u32 nfsd4_test_stateid_rsize(const struct svc_rqst *rqstp,
+				    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1 + op->u.test_stateid.ts_num_ids)
+		* sizeof(__be32);
+}
+
+static u32 nfsd4_setattr_rsize(const struct svc_rqst *rqstp,
+			       const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_secinfo_rsize(const struct svc_rqst *rqstp,
+			       const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + RPC_AUTH_MAXFLAVOR *
+		(4 + XDR_QUADLEN(GSS_OID_MAX_LEN))) * sizeof(__be32);
+}
+
+static u32 nfsd4_setclientid_rsize(const struct svc_rqst *rqstp,
+				   const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(NFS4_VERIFIER_SIZE)) *
+								sizeof(__be32);
+}
+
+static u32 nfsd4_write_rsize(const struct svc_rqst *rqstp,
+			     const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_exchange_id_rsize(const struct svc_rqst *rqstp,
+				   const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
+		1 + 1 + /* eir_flags, spr_how */\
+		4 + /* spo_must_enforce & _allow with bitmap */\
+		2 + /*eir_server_owner.so_minor_id */\
+		/* eir_server_owner.so_major_id<> */\
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+		/* eir_server_scope<> */\
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+		1 + /* eir_server_impl_id array length */\
+		0 /* ignored eir_server_impl_id contents */) * sizeof(__be32);
+}
+
+static u32 nfsd4_bind_conn_to_session_rsize(const struct svc_rqst *rqstp,
+					    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + \
+		XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* bctsr_sessid */\
+		2 /* bctsr_dir, use_conn_in_rdma_mode */) * sizeof(__be32);
+}
+
+static u32 nfsd4_create_session_rsize(const struct svc_rqst *rqstp,
+				      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + \
+		XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* sessionid */\
+		2 + /* csr_sequence, csr_flags */\
+		op_encode_channel_attrs_maxsz + \
+		op_encode_channel_attrs_maxsz) * sizeof(__be32);
+}
+
+static u32 nfsd4_copy_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* wr_callback */ +
+		op_encode_stateid_maxsz /* wr_callback */ +
+		2 /* wr_count */ +
+		1 /* wr_committed */ +
+		op_encode_verifier_maxsz +
+		1 /* cr_consecutive */ +
+		1 /* cr_synchronous */) * sizeof(__be32);
+}
+
+static u32 nfsd4_offload_status_rsize(const struct svc_rqst *rqstp,
+				      const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		2 /* osr_count */ +
+		1 /* osr_complete<1> optional 0 for now */) * sizeof(__be32);
+}
+
+static u32 nfsd4_copy_notify_rsize(const struct svc_rqst *rqstp,
+				   const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		3 /* cnr_lease_time */ +
+		1 /* We support one cnr_source_server */ +
+		1 /* cnr_stateid seq */ +
+		op_encode_stateid_maxsz /* cnr_stateid */ +
+		1 /* num cnr_source_server*/ +
+		1 /* nl4_type */ +
+		1 /* nl4 size */ +
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) /*nl4_loc + nl4_loc_sz */)
+		* sizeof(__be32);
+}
+
+static u32 nfsd4_get_dir_delegation_rsize(const struct svc_rqst *rqstp,
+					  const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* gddr_status */ +
+		op_encode_verifier_maxsz +
+		op_encode_stateid_maxsz +
+		2 /* gddr_notification */ +
+		3 /* gddr_child_attributes */ +
+		3 /* gddr_dir_attributes */) * sizeof(__be32);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static u32 nfsd4_getdeviceinfo_rsize(const struct svc_rqst *rqstp,
+				     const struct nfsd4_op *op)
+{
+	u32 rlen = min(op->u.getdeviceinfo.gd_maxcount, nfsd4_max_payload(rqstp));
+
+	return (op_encode_hdr_size +
+		1 /* gd_layout_type*/ +
+		XDR_QUADLEN(rlen) +
+		2 /* gd_notify_types */) * sizeof(__be32);
+}
+
+/*
+ * At this stage we don't really know what layout driver will handle the request,
+ * so we need to define an arbitrary upper bound here.
+ */
+#define MAX_LAYOUT_SIZE		128
+static u32 nfsd4_layoutget_rsize(const struct svc_rqst *rqstp,
+				 const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* logr_return_on_close */ +
+		op_encode_stateid_maxsz +
+		1 /* nr of layouts */ +
+		MAX_LAYOUT_SIZE) * sizeof(__be32);
+}
+
+static u32 nfsd4_layoutcommit_rsize(const struct svc_rqst *rqstp,
+				    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* locr_newsize */ +
+		2 /* ns_size */) * sizeof(__be32);
+}
+
+static u32 nfsd4_layoutreturn_rsize(const struct svc_rqst *rqstp,
+				    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* lrs_stateid */ +
+		op_encode_stateid_maxsz) * sizeof(__be32);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+
+static u32 nfsd4_seek_rsize(const struct svc_rqst *rqstp,
+			    const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 3) * sizeof(__be32);
+}
+
+static u32 nfsd4_getxattr_rsize(const struct svc_rqst *rqstp,
+				const struct nfsd4_op *op)
+{
+	u32 rlen = min_t(u32, XATTR_SIZE_MAX, nfsd4_max_payload(rqstp));
+
+	return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static u32 nfsd4_setxattr_rsize(const struct svc_rqst *rqstp,
+				const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+static u32 nfsd4_listxattrs_rsize(const struct svc_rqst *rqstp,
+				  const struct nfsd4_op *op)
+{
+	u32 rlen = min(op->u.listxattrs.lsxa_maxcount, nfsd4_max_payload(rqstp));
+
+	return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static u32 nfsd4_removexattr_rsize(const struct svc_rqst *rqstp,
+				   const struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+
+static const struct nfsd4_operation nfsd4_ops[] = {
+	[OP_ACCESS] = {
+		.op_func = nfsd4_access,
+		.op_name = "OP_ACCESS",
+		.op_rsize_bop = nfsd4_access_rsize,
+	},
+	[OP_CLOSE] = {
+		.op_func = nfsd4_close,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CLOSE",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_closestateid,
+		.op_set_currentstateid = nfsd4_set_closestateid,
+	},
+	[OP_COMMIT] = {
+		.op_func = nfsd4_commit,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COMMIT",
+		.op_rsize_bop = nfsd4_commit_rsize,
+	},
+	[OP_CREATE] = {
+		.op_func = nfsd4_create,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME | OP_CLEAR_STATEID,
+		.op_name = "OP_CREATE",
+		.op_rsize_bop = nfsd4_create_rsize,
+	},
+	[OP_DELEGRETURN] = {
+		.op_func = nfsd4_delegreturn,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DELEGRETURN",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+		.op_get_currentstateid = nfsd4_get_delegreturnstateid,
+	},
+	[OP_GETATTR] = {
+		.op_func = nfsd4_getattr,
+		.op_flags = ALLOWED_ON_ABSENT_FS,
+		.op_rsize_bop = nfsd4_getattr_rsize,
+		.op_name = "OP_GETATTR",
+	},
+	[OP_GETFH] = {
+		.op_func = nfsd4_getfh,
+		.op_name = "OP_GETFH",
+		.op_rsize_bop = nfsd4_getfh_rsize,
+	},
+	[OP_LINK] = {
+		.op_func = nfsd4_link,
+		.op_flags = ALLOWED_ON_ABSENT_FS | OP_MODIFIES_SOMETHING
+				| OP_CACHEME,
+		.op_name = "OP_LINK",
+		.op_rsize_bop = nfsd4_link_rsize,
+	},
+	[OP_LOCK] = {
+		.op_func = nfsd4_lock,
+		.op_release = nfsd4_lock_release,
+		.op_flags = OP_MODIFIES_SOMETHING |
+				OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_LOCK",
+		.op_rsize_bop = nfsd4_lock_rsize,
+		.op_set_currentstateid = nfsd4_set_lockstateid,
+	},
+	[OP_LOCKT] = {
+		.op_func = nfsd4_lockt,
+		.op_release = nfsd4_lockt_release,
+		.op_flags = OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_LOCKT",
+		.op_rsize_bop = nfsd4_lock_rsize,
+	},
+	[OP_LOCKU] = {
+		.op_func = nfsd4_locku,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LOCKU",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_lockustateid,
+	},
+	[OP_LOOKUP] = {
+		.op_func = nfsd4_lookup,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
+		.op_name = "OP_LOOKUP",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_LOOKUPP] = {
+		.op_func = nfsd4_lookupp,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
+		.op_name = "OP_LOOKUPP",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_NVERIFY] = {
+		.op_func = nfsd4_nverify,
+		.op_name = "OP_NVERIFY",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_OPEN] = {
+		.op_func = nfsd4_open,
+		.op_release = nfsd4_open_release,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN",
+		.op_rsize_bop = nfsd4_open_rsize,
+		.op_set_currentstateid = nfsd4_set_openstateid,
+	},
+	[OP_OPEN_CONFIRM] = {
+		.op_func = nfsd4_open_confirm,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN_CONFIRM",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+	},
+	[OP_OPEN_DOWNGRADE] = {
+		.op_func = nfsd4_open_downgrade,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN_DOWNGRADE",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_opendowngradestateid,
+		.op_set_currentstateid = nfsd4_set_opendowngradestateid,
+	},
+	[OP_PUTFH] = {
+		.op_func = nfsd4_putfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_PUTPUBFH] = {
+		.op_func = nfsd4_putrootfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTPUBFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_PUTROOTFH] = {
+		.op_func = nfsd4_putrootfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTROOTFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_READ] = {
+		.op_func = nfsd4_read,
+		.op_release = nfsd4_read_release,
+		.op_name = "OP_READ",
+		.op_rsize_bop = nfsd4_read_rsize,
+		.op_get_currentstateid = nfsd4_get_readstateid,
+	},
+	[OP_READDIR] = {
+		.op_func = nfsd4_readdir,
+		.op_name = "OP_READDIR",
+		.op_rsize_bop = nfsd4_readdir_rsize,
+	},
+	[OP_READLINK] = {
+		.op_func = nfsd4_readlink,
+		.op_name = "OP_READLINK",
+		.op_rsize_bop = nfsd4_readlink_rsize,
+	},
+	[OP_REMOVE] = {
+		.op_func = nfsd4_remove,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_REMOVE",
+		.op_rsize_bop = nfsd4_remove_rsize,
+	},
+	[OP_RENAME] = {
+		.op_func = nfsd4_rename,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_RENAME",
+		.op_rsize_bop = nfsd4_rename_rsize,
+	},
+	[OP_RENEW] = {
+		.op_func = nfsd4_renew,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RENEW",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+
+	},
+	[OP_RESTOREFH] = {
+		.op_func = nfsd4_restorefh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RESTOREFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SAVEFH] = {
+		.op_func = nfsd4_savefh,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_SAVEFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SECINFO] = {
+		.op_func = nfsd4_secinfo,
+		.op_release = nfsd4_secinfo_release,
+		.op_flags = OP_HANDLES_WRONGSEC,
+		.op_name = "OP_SECINFO",
+		.op_rsize_bop = nfsd4_secinfo_rsize,
+	},
+	[OP_SETATTR] = {
+		.op_func = nfsd4_setattr,
+		.op_name = "OP_SETATTR",
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_rsize_bop = nfsd4_setattr_rsize,
+		.op_get_currentstateid = nfsd4_get_setattrstateid,
+	},
+	[OP_SETCLIENTID] = {
+		.op_func = nfsd4_setclientid,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_SETCLIENTID",
+		.op_rsize_bop = nfsd4_setclientid_rsize,
+	},
+	[OP_SETCLIENTID_CONFIRM] = {
+		.op_func = nfsd4_setclientid_confirm,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_SETCLIENTID_CONFIRM",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_VERIFY] = {
+		.op_func = nfsd4_verify,
+		.op_name = "OP_VERIFY",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_WRITE] = {
+		.op_func = nfsd4_write,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_WRITE",
+		.op_rsize_bop = nfsd4_write_rsize,
+		.op_get_currentstateid = nfsd4_get_writestateid,
+	},
+	[OP_RELEASE_LOCKOWNER] = {
+		.op_func = nfsd4_release_lockowner,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RELEASE_LOCKOWNER",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+
+	/* NFSv4.1 operations */
+	[OP_EXCHANGE_ID] = {
+		.op_func = nfsd4_exchange_id,
+		.op_release = nfsd4_exchange_id_release,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_EXCHANGE_ID",
+		.op_rsize_bop = nfsd4_exchange_id_rsize,
+	},
+	[OP_BACKCHANNEL_CTL] = {
+		.op_func = nfsd4_backchannel_ctl,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_BACKCHANNEL_CTL",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_BIND_CONN_TO_SESSION] = {
+		.op_func = nfsd4_bind_conn_to_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_BIND_CONN_TO_SESSION",
+		.op_rsize_bop = nfsd4_bind_conn_to_session_rsize,
+	},
+	[OP_CREATE_SESSION] = {
+		.op_func = nfsd4_create_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CREATE_SESSION",
+		.op_rsize_bop = nfsd4_create_session_rsize,
+	},
+	[OP_DESTROY_SESSION] = {
+		.op_func = nfsd4_destroy_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DESTROY_SESSION",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SEQUENCE] = {
+		.op_func = nfsd4_sequence,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+		.op_name = "OP_SEQUENCE",
+		.op_rsize_bop = nfsd4_sequence_rsize,
+	},
+	[OP_DESTROY_CLIENTID] = {
+		.op_func = nfsd4_destroy_clientid,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DESTROY_CLIENTID",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_RECLAIM_COMPLETE] = {
+		.op_func = nfsd4_reclaim_complete,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RECLAIM_COMPLETE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SECINFO_NO_NAME] = {
+		.op_func = nfsd4_secinfo_no_name,
+		.op_release = nfsd4_secinfo_no_name_release,
+		.op_flags = OP_HANDLES_WRONGSEC,
+		.op_name = "OP_SECINFO_NO_NAME",
+		.op_rsize_bop = nfsd4_secinfo_rsize,
+	},
+	[OP_TEST_STATEID] = {
+		.op_func = nfsd4_test_stateid,
+		.op_flags = ALLOWED_WITHOUT_FH,
+		.op_name = "OP_TEST_STATEID",
+		.op_rsize_bop = nfsd4_test_stateid_rsize,
+	},
+	[OP_FREE_STATEID] = {
+		.op_func = nfsd4_free_stateid,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_FREE_STATEID",
+		.op_get_currentstateid = nfsd4_get_freestateid,
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_GET_DIR_DELEGATION] = {
+		.op_func = nfsd4_get_dir_delegation,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_GET_DIR_DELEGATION",
+		.op_rsize_bop = nfsd4_get_dir_delegation_rsize,
+	},
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO] = {
+		.op_func = nfsd4_getdeviceinfo,
+		.op_release = nfsd4_getdeviceinfo_release,
+		.op_flags = ALLOWED_WITHOUT_FH,
+		.op_name = "OP_GETDEVICEINFO",
+		.op_rsize_bop = nfsd4_getdeviceinfo_rsize,
+	},
+	[OP_LAYOUTGET] = {
+		.op_func = nfsd4_layoutget,
+		.op_release = nfsd4_layoutget_release,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTGET",
+		.op_rsize_bop = nfsd4_layoutget_rsize,
+	},
+	[OP_LAYOUTCOMMIT] = {
+		.op_func = nfsd4_layoutcommit,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTCOMMIT",
+		.op_rsize_bop = nfsd4_layoutcommit_rsize,
+	},
+	[OP_LAYOUTRETURN] = {
+		.op_func = nfsd4_layoutreturn,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTRETURN",
+		.op_rsize_bop = nfsd4_layoutreturn_rsize,
+	},
+#endif /* CONFIG_NFSD_PNFS */
+
+	/* NFSv4.2 operations */
+	[OP_ALLOCATE] = {
+		.op_func = nfsd4_allocate,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_ALLOCATE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_DEALLOCATE] = {
+		.op_func = nfsd4_deallocate,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DEALLOCATE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_CLONE] = {
+		.op_func = nfsd4_clone,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CLONE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_COPY] = {
+		.op_func = nfsd4_copy,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COPY",
+		.op_rsize_bop = nfsd4_copy_rsize,
+	},
+	[OP_READ_PLUS] = {
+		.op_func = nfsd4_read,
+		.op_release = nfsd4_read_release,
+		.op_name = "OP_READ_PLUS",
+		.op_rsize_bop = nfsd4_read_plus_rsize,
+		.op_get_currentstateid = nfsd4_get_readstateid,
+	},
+	[OP_SEEK] = {
+		.op_func = nfsd4_seek,
+		.op_name = "OP_SEEK",
+		.op_rsize_bop = nfsd4_seek_rsize,
+	},
+	[OP_OFFLOAD_STATUS] = {
+		.op_func = nfsd4_offload_status,
+		.op_name = "OP_OFFLOAD_STATUS",
+		.op_rsize_bop = nfsd4_offload_status_rsize,
+	},
+	[OP_OFFLOAD_CANCEL] = {
+		.op_func = nfsd4_offload_cancel,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OFFLOAD_CANCEL",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_COPY_NOTIFY] = {
+		.op_func = nfsd4_copy_notify,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COPY_NOTIFY",
+		.op_rsize_bop = nfsd4_copy_notify_rsize,
+	},
+	[OP_GETXATTR] = {
+		.op_func = nfsd4_getxattr,
+		.op_name = "OP_GETXATTR",
+		.op_rsize_bop = nfsd4_getxattr_rsize,
+	},
+	[OP_SETXATTR] = {
+		.op_func = nfsd4_setxattr,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_SETXATTR",
+		.op_rsize_bop = nfsd4_setxattr_rsize,
+	},
+	[OP_LISTXATTRS] = {
+		.op_func = nfsd4_listxattrs,
+		.op_name = "OP_LISTXATTRS",
+		.op_rsize_bop = nfsd4_listxattrs_rsize,
+	},
+	[OP_REMOVEXATTR] = {
+		.op_func = nfsd4_removexattr,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_REMOVEXATTR",
+		.op_rsize_bop = nfsd4_removexattr_rsize,
+	},
+};
+
+/**
+ * nfsd4_spo_must_allow - Determine if the compound op contains an
+ * operation that is allowed to be sent with machine credentials
+ *
+ * @rqstp: a pointer to the struct svc_rqst
+ *
+ * Checks to see if the compound contains a spo_must_allow op
+ * and confirms that it was sent with the proper machine creds.
+ */
+
+bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+	struct nfsd4_op *this;
+	struct nfsd4_compound_state *cstate = &resp->cstate;
+	struct nfs4_op_map *allow = &cstate->clp->cl_spo_must_allow;
+	u32 opiter;
+
+	if (rqstp->rq_procinfo != &nfsd_version4.vs_proc[NFSPROC4_COMPOUND] ||
+	    cstate->minorversion == 0)
+		return false;
+
+	if (cstate->spo_must_allowed)
+		return true;
+
+	opiter = resp->opcnt;
+	while (opiter < argp->opcnt) {
+		this = &argp->ops[opiter++];
+		if (test_bit(this->opnum, allow->u.longs) &&
+			cstate->clp->cl_mach_cred &&
+			nfsd4_mach_creds_match(cstate->clp, rqstp)) {
+			cstate->spo_must_allowed = true;
+			return true;
+		}
+	}
+	cstate->spo_must_allowed = false;
+	return false;
+}
+
+int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	if (op->opnum == OP_ILLEGAL || op->status == nfserr_notsupp)
+		return op_encode_hdr_size * sizeof(__be32);
+
+	BUG_ON(OPDESC(op)->op_rsize_bop == NULL);
+	return OPDESC(op)->op_rsize_bop(rqstp, op);
+}
+
+void warn_on_nonidempotent_op(struct nfsd4_op *op)
+{
+	if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {
+		pr_err("unable to encode reply to nonidempotent op %u (%s)\n",
+			op->opnum, nfsd4_op_name(op->opnum));
+		WARN_ON_ONCE(1);
+	}
+}
+
+static const char *nfsd4_op_name(unsigned opnum)
+{
+	if (opnum < ARRAY_SIZE(nfsd4_ops))
+		return nfsd4_ops[opnum].op_name;
+	return "unknown_operation";
+}
+
+static const struct svc_procedure nfsd_procedures4[2] = {
+	[NFSPROC4_NULL] = {
+		.pc_func = nfsd4_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 1,
+		.pc_name = "NULL",
+	},
+	[NFSPROC4_COMPOUND] = {
+		.pc_func = nfsd4_proc_compound,
+		.pc_decode = nfs4svc_decode_compoundargs,
+		.pc_encode = nfs4svc_encode_compoundres,
+		.pc_argsize = sizeof(struct nfsd4_compoundargs),
+		.pc_argzero = offsetof(struct nfsd4_compoundargs, iops),
+		.pc_ressize = sizeof(struct nfsd4_compoundres),
+		.pc_release = nfsd4_release_compoundargs,
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 3+NFSSVC_MAXBLKSIZE/4,
+		.pc_name = "COMPOUND",
+	},
+};
+
+const struct svc_version nfsd_version4 = {
+	.vs_vers		= 4,
+	.vs_nproc		= ARRAY_SIZE(nfsd_procedures4),
+	.vs_proc		= nfsd_procedures4,
+	.vs_dispatch		= nfsd_dispatch,
+	.vs_xdrsize		= NFS4_SVC_XDRSIZE,
+	.vs_rpcb_optnl		= true,
+	.vs_need_cong_ctrl	= true,
+};
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
new file mode 100644
index 000000000..d513971fb
--- /dev/null
+++ b/fs/nfsd/nfs4recover.c
@@ -0,0 +1,2060 @@
+/*
+*  Copyright (c) 2004 The Regents of the University of Michigan.
+*  Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
+*  All rights reserved.
+*
+*  Andy Adamson <andros@citi.umich.edu>
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions
+*  are met:
+*
+*  1. Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*  2. Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in the
+*     documentation and/or other materials provided with the distribution.
+*  3. Neither the name of the University nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+*/
+
+#include <crypto/md5.h>
+#include <crypto/sha2.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/hex.h>
+#include <linux/module.h>
+#include <net/net_namespace.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfsd/cld.h>
+
+#include "nfsd.h"
+#include "state.h"
+#include "vfs.h"
+#include "netns.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+/* Declarations */
+struct nfsd4_client_tracking_ops {
+	int (*init)(struct net *);
+	void (*exit)(struct net *);
+	void (*create)(struct nfs4_client *);
+	void (*remove)(struct nfs4_client *);
+	int (*check)(struct nfs4_client *);
+	void (*grace_done)(struct nfsd_net *);
+	uint8_t version;
+	size_t msglen;
+};
+
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+/* Globals */
+static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
+
+static int
+nfs4_save_creds(const struct cred **original_creds)
+{
+	struct cred *new;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	new->fsuid = GLOBAL_ROOT_UID;
+	new->fsgid = GLOBAL_ROOT_GID;
+	*original_creds = override_creds(new);
+	return 0;
+}
+
+static void
+nfs4_reset_creds(const struct cred *original)
+{
+	put_cred(revert_creds(original));
+}
+
+static void
+nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
+{
+	u8 digest[MD5_DIGEST_SIZE];
+
+	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
+			clname->len, clname->data);
+
+	md5(clname->data, clname->len, digest);
+
+	static_assert(HEXDIR_LEN == 2 * MD5_DIGEST_SIZE + 1);
+	sprintf(dname, "%*phN", MD5_DIGEST_SIZE, digest);
+}
+
+static void
+__nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
+				    char *dname, struct nfsd_net *nn)
+{
+	struct xdr_netobj name = { .len = strlen(dname), .data = dname };
+	struct xdr_netobj princhash = { .len = 0, .data = NULL };
+	struct nfs4_client_reclaim *crp;
+
+	crp = nfs4_client_to_reclaim(name, princhash, nn);
+	crp->cr_clp = clp;
+}
+
+static void
+nfsd4_create_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	char dname[HEXDIR_LEN];
+	struct dentry *dir, *dentry;
+	int status;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+	if (!nn->rec_file)
+		return;
+
+	nfs4_make_rec_clidname(dname, &clp->cl_name);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return;
+
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out_creds;
+
+	dir = nn->rec_file->f_path.dentry;
+
+	dentry = start_creating(&nop_mnt_idmap, dir, &QSTR(dname));
+	if (IS_ERR(dentry)) {
+		status = PTR_ERR(dentry);
+		goto out;
+	}
+	if (d_really_is_positive(dentry))
+		/*
+		 * In the 4.1 case, where we're called from
+		 * reclaim_complete(), records from the previous reboot
+		 * may still be left, so this is OK.
+		 *
+		 * In the 4.0 case, we should never get here; but we may
+		 * as well be forgiving and just succeed silently.
+		 */
+		goto out_end;
+	dentry = vfs_mkdir(&nop_mnt_idmap, d_inode(dir), dentry, 0700, NULL);
+	if (IS_ERR(dentry))
+		status = PTR_ERR(dentry);
+out_end:
+	end_creating(dentry);
+out:
+	if (status == 0) {
+		if (test_bit(NFSD_NET_IN_GRACE, &nn->flags))
+			__nfsd4_create_reclaim_record_grace(clp, dname, nn);
+		vfs_fsync(nn->rec_file, 0);
+	} else {
+		printk(KERN_ERR "NFSD: failed to write recovery record"
+				" (err %d); please check that %s exists"
+				" and is writeable", status,
+				user_recovery_dirname);
+	}
+	mnt_drop_write_file(nn->rec_file);
+out_creds:
+	nfs4_reset_creds(original_cred);
+}
+
+typedef int (recdir_func)(struct dentry *, char *, struct nfsd_net *);
+
+struct name_list {
+	char name[HEXDIR_LEN];
+	struct list_head list;
+};
+
+struct nfs4_dir_ctx {
+	struct dir_context ctx;
+	struct list_head names;
+};
+
+static bool
+nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
+		loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct nfs4_dir_ctx *ctx =
+		container_of(__ctx, struct nfs4_dir_ctx, ctx);
+	struct name_list *entry;
+
+	if (namlen != HEXDIR_LEN - 1)
+		return true;
+	entry = kmalloc_obj(struct name_list);
+	if (entry == NULL)
+		return false;
+	memcpy(entry->name, name, HEXDIR_LEN - 1);
+	entry->name[HEXDIR_LEN - 1] = '\0';
+	list_add(&entry->list, &ctx->names);
+	return true;
+}
+
+static int
+nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
+{
+	const struct cred *original_cred;
+	struct dentry *dir = nn->rec_file->f_path.dentry;
+	struct nfs4_dir_ctx ctx = {
+		.ctx.actor = nfsd4_build_namelist,
+		.names = LIST_HEAD_INIT(ctx.names)
+	};
+	struct name_list *entry, *tmp;
+	int status;
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return status;
+
+	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
+	if (status < 0) {
+		nfs4_reset_creds(original_cred);
+		return status;
+	}
+
+	status = iterate_dir(nn->rec_file, &ctx.ctx);
+
+	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
+		if (!status)
+			status = f(dir, entry->name, nn);
+
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	nfs4_reset_creds(original_cred);
+
+	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
+		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	return status;
+}
+
+static int
+nfsd4_unlink_clid_dir(char *name, struct nfsd_net *nn)
+{
+	struct dentry *dir, *dentry;
+	int status;
+
+	dprintk("NFSD: nfsd4_unlink_clid_dir. name %s\n", name);
+
+	dir = nn->rec_file->f_path.dentry;
+	dentry = start_removing(&nop_mnt_idmap, dir, &QSTR(name));
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	status = vfs_rmdir(&nop_mnt_idmap, d_inode(dir), dentry, NULL);
+	end_removing(dentry);
+	return status;
+}
+
+static void
+__nfsd4_remove_reclaim_record_grace(const char *dname, int len,
+		struct nfsd_net *nn)
+{
+	struct xdr_netobj name;
+	struct nfs4_client_reclaim *crp;
+
+	name.data = kmemdup(dname, len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		return;
+	}
+	name.len = len;
+	down_write(&nn->reclaim_str_hashtbl_lock);
+	crp = nfsd4_find_reclaim_client(name, nn);
+	if (crp)
+		nfs4_remove_reclaim_record(crp, nn);
+	up_write(&nn->reclaim_str_hashtbl_lock);
+	kfree(name.data);
+}
+
+static void
+nfsd4_remove_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	char dname[HEXDIR_LEN];
+	int status;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	nfs4_make_rec_clidname(dname, &clp->cl_name);
+
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out;
+	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		goto out_drop_write;
+
+	status = nfsd4_unlink_clid_dir(dname, nn);
+	nfs4_reset_creds(original_cred);
+	if (status == 0) {
+		vfs_fsync(nn->rec_file, 0);
+		if (test_bit(NFSD_NET_IN_GRACE, &nn->flags))
+			__nfsd4_remove_reclaim_record_grace(dname,
+					HEXDIR_LEN, nn);
+	}
+out_drop_write:
+	mnt_drop_write_file(nn->rec_file);
+out:
+	if (status)
+		printk("NFSD: Failed to remove expired client state directory"
+				" %.*s\n", HEXDIR_LEN, dname);
+}
+
+static int
+purge_old(struct dentry *parent, char *cname, struct nfsd_net *nn)
+{
+	int status;
+	struct dentry *child;
+	struct xdr_netobj name;
+
+	if (strlen(cname) != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %s in recovery directory\n",
+				__func__, cname);
+		/* Keep trying; maybe the others are OK: */
+		return 0;
+	}
+	name.data = kstrdup(cname, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		goto out;
+	}
+	name.len = HEXDIR_LEN;
+	if (nfs4_has_reclaimed_state(name, nn))
+		goto out_free;
+
+	child = start_removing_noperm(parent, &QSTR(cname));
+	if (!IS_ERR(child)) {
+		status = vfs_rmdir(&nop_mnt_idmap, d_inode(parent), child, NULL);
+		if (status)
+			printk("failed to remove client recovery directory %pd\n",
+			       child);
+	}
+	end_removing(child);
+
+out_free:
+	kfree(name.data);
+out:
+	/* Keep trying, success or failure: */
+	return 0;
+}
+
+static void
+nfsd4_recdir_purge_old(struct nfsd_net *nn)
+{
+	int status;
+
+	clear_bit(NFSD_NET_IN_GRACE, &nn->flags);
+	if (!nn->rec_file)
+		return;
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out;
+	status = nfsd4_list_rec_dir(purge_old, nn);
+	if (status == 0)
+		vfs_fsync(nn->rec_file, 0);
+	mnt_drop_write_file(nn->rec_file);
+out:
+	nfs4_release_reclaim(nn);
+	if (status)
+		printk("nfsd4: failed to purge old clients from recovery"
+			" directory %pD\n", nn->rec_file);
+}
+
+static int
+load_recdir(struct dentry *parent, char *cname, struct nfsd_net *nn)
+{
+	struct xdr_netobj name = { .len = HEXDIR_LEN, .data = cname };
+	struct xdr_netobj princhash = { .len = 0, .data = NULL };
+
+	if (strlen(cname) != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %s in recovery directory\n",
+				__func__, cname);
+		/* Keep trying; maybe the others are OK: */
+		return 0;
+	}
+	nfs4_client_to_reclaim(name, princhash, nn);
+	return 0;
+}
+
+static int
+nfsd4_recdir_load(struct net *net) {
+	int status;
+	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
+
+	if (!nn->rec_file)
+		return 0;
+
+	status = nfsd4_list_rec_dir(load_recdir, nn);
+	if (status)
+		printk("nfsd4: failed loading clients from recovery"
+			" directory %pD\n", nn->rec_file);
+	return status;
+}
+
+/*
+ * Hold reference to the recovery directory.
+ */
+
+static int
+nfsd4_init_recdir(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	const struct cred *original_cred;
+	int status;
+
+	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
+			user_recovery_dirname);
+
+	BUG_ON(nn->rec_file);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0) {
+		printk("NFSD: Unable to change credentials to find recovery"
+		       " directory: error %d\n",
+		       status);
+		return status;
+	}
+
+	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
+	if (IS_ERR(nn->rec_file)) {
+		printk("NFSD: unable to find recovery directory %s\n",
+				user_recovery_dirname);
+		status = PTR_ERR(nn->rec_file);
+		nn->rec_file = NULL;
+	}
+
+	nfs4_reset_creds(original_cred);
+	if (!status)
+		set_bit(NFSD_NET_IN_GRACE, &nn->flags);
+	return status;
+}
+
+static void
+nfsd4_shutdown_recdir(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (!nn->rec_file)
+		return;
+	fput(nn->rec_file);
+	nn->rec_file = NULL;
+}
+
+static int
+nfs4_legacy_state_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->reclaim_str_hashtbl = kmalloc_objs(struct list_head,
+					       CLIENT_HASH_SIZE);
+	if (!nn->reclaim_str_hashtbl)
+		return -ENOMEM;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
+	nn->reclaim_str_hashtbl_size = 0;
+	init_rwsem(&nn->reclaim_str_hashtbl_lock);
+
+	return 0;
+}
+
+static void
+nfs4_legacy_state_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	kfree(nn->reclaim_str_hashtbl);
+}
+
+static int
+nfsd4_load_reboot_recovery_data(struct net *net)
+{
+	int status;
+
+	status = nfsd4_init_recdir(net);
+	if (status)
+		return status;
+
+	status = nfsd4_recdir_load(net);
+	if (status)
+		nfsd4_shutdown_recdir(net);
+
+	return status;
+}
+
+static int
+nfsd4_legacy_tracking_init(struct net *net)
+{
+	int status;
+
+	/* XXX: The legacy code won't work in a container */
+	if (net != &init_net) {
+		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
+		return -EINVAL;
+	}
+
+	status = nfs4_legacy_state_init(net);
+	if (status)
+		return status;
+
+	status = nfsd4_load_reboot_recovery_data(net);
+	if (status)
+		goto err;
+	pr_info("NFSD: Using legacy client tracking operations.\n");
+	return 0;
+
+err:
+	nfs4_legacy_state_shutdown(net);
+	return status;
+}
+
+static void
+nfsd4_legacy_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs4_release_reclaim(nn);
+	nfsd4_shutdown_recdir(net);
+	nfs4_legacy_state_shutdown(net);
+}
+
+/*
+ * Change the NFSv4 recovery directory to recdir.
+ */
+int
+nfs4_reset_recoverydir(char *recdir)
+{
+	int status;
+	struct path path;
+
+	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
+	if (status)
+		return status;
+	status = -ENOTDIR;
+	if (d_is_dir(path.dentry)) {
+		strscpy(user_recovery_dirname, recdir,
+			sizeof(user_recovery_dirname));
+		status = 0;
+	}
+	path_put(&path);
+	return status;
+}
+
+char *
+nfs4_recoverydir(void)
+{
+	return user_recovery_dirname;
+}
+
+static int
+nfsd4_check_legacy_client(struct nfs4_client *clp)
+{
+	char dname[HEXDIR_LEN];
+	struct nfs4_client_reclaim *crp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct xdr_netobj name;
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	nfs4_make_rec_clidname(dname, &clp->cl_name);
+
+	/* look for it in the reclaim hashtable otherwise */
+	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		goto out_enoent;
+	}
+	name.len = HEXDIR_LEN;
+	down_read(&nn->reclaim_str_hashtbl_lock);
+	crp = nfsd4_find_reclaim_client(name, nn);
+	if (crp) {
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+		crp->cr_clp = clp;
+	}
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	kfree(name.data);
+	if (crp)
+		return 0;
+
+out_enoent:
+	return -ENOENT;
+}
+
+static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
+	.init		= nfsd4_legacy_tracking_init,
+	.exit		= nfsd4_legacy_tracking_exit,
+	.create		= nfsd4_create_clid_dir,
+	.remove		= nfsd4_remove_clid_dir,
+	.check		= nfsd4_check_legacy_client,
+	.grace_done	= nfsd4_recdir_purge_old,
+	.version	= 1,
+	.msglen		= 0,
+};
+#endif /* CONFIG_NFSD_LEGACY_CLIENT_TRACKING */
+
+/* Globals */
+#define NFSD_PIPE_DIR		"nfsd"
+#define NFSD_CLD_PIPE		"cld"
+
+/* per-net-ns structure for holding cld upcall info */
+struct cld_net {
+	struct rpc_pipe		*cn_pipe;
+	spinlock_t		 cn_lock;
+	struct list_head	 cn_list;
+	unsigned int		 cn_xid;
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	bool			 cn_has_legacy;
+#endif
+};
+
+struct cld_upcall {
+	struct list_head	 cu_list;
+	struct cld_net		*cu_net;
+	struct completion	 cu_done;
+	union {
+		struct cld_msg_hdr	 cu_hdr;
+		struct cld_msg		 cu_msg;
+		struct cld_msg_v2	 cu_msg_v2;
+	} cu_u;
+};
+
+static int
+__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
+{
+	int ret;
+	struct rpc_pipe_msg msg;
+	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
+
+	memset(&msg, 0, sizeof(msg));
+	msg.data = cmsg;
+	msg.len = nn->client_tracking_ops->msglen;
+
+	ret = rpc_queue_upcall(pipe, &msg);
+	if (ret < 0) {
+		goto out;
+	}
+
+	wait_for_completion(&cup->cu_done);
+
+	if (msg.errno < 0)
+		ret = msg.errno;
+out:
+	return ret;
+}
+
+static int
+cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
+{
+	int ret;
+
+	/*
+	 * -EAGAIN occurs when pipe is closed and reopened while there are
+	 *  upcalls queued.
+	 */
+	do {
+		ret = __cld_pipe_upcall(pipe, cmsg, nn);
+	} while (ret == -EAGAIN);
+
+	return ret;
+}
+
+static ssize_t
+__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
+		struct nfsd_net *nn)
+{
+	uint8_t cmd, princhashlen;
+	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
+	char *namecopy __free(kfree) = NULL;
+	char *princhashcopy __free(kfree) = NULL;
+	uint16_t namelen;
+
+	if (get_user(cmd, &cmsg->cm_cmd)) {
+		dprintk("%s: error when copying cmd from userspace", __func__);
+		return -EFAULT;
+	}
+	if (cmd == Cld_GraceStart) {
+		if (nn->client_tracking_ops->version >= 2) {
+			const struct cld_clntinfo __user *ci;
+
+			ci = &cmsg->cm_u.cm_clntinfo;
+			if (get_user(namelen, &ci->cc_name.cn_len))
+				return -EFAULT;
+			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
+				dprintk("%s: invalid namelen (%u)", __func__, namelen);
+				return -EINVAL;
+			}
+			namecopy = memdup_user(&ci->cc_name.cn_id, namelen);
+			if (IS_ERR(namecopy))
+				return PTR_ERR(namecopy);
+			name.data = namecopy;
+			name.len = namelen;
+			if (get_user(princhashlen, &ci->cc_princhash.cp_len))
+				return -EFAULT;
+			if (princhashlen > 0) {
+				princhashcopy = memdup_user(
+					&ci->cc_princhash.cp_data,
+					princhashlen);
+				if (IS_ERR(princhashcopy))
+					return PTR_ERR(princhashcopy);
+				princhash.data = princhashcopy;
+				princhash.len = princhashlen;
+			} else
+				princhash.len = 0;
+		} else {
+			const struct cld_name __user *cnm;
+
+			cnm = &cmsg->cm_u.cm_name;
+			if (get_user(namelen, &cnm->cn_len))
+				return -EFAULT;
+			if (namelen == 0 || namelen > NFS4_OPAQUE_LIMIT) {
+				dprintk("%s: invalid namelen (%u)", __func__, namelen);
+				return -EINVAL;
+			}
+			namecopy = memdup_user(&cnm->cn_id, namelen);
+			if (IS_ERR(namecopy))
+				return PTR_ERR(namecopy);
+			name.data = namecopy;
+			name.len = namelen;
+		}
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
+			struct cld_net *cn = nn->cld_net;
+
+			name.len = name.len - 5;
+			name.data = name.data + 5;
+			cn->cn_has_legacy = true;
+		}
+#endif
+		if (!nfs4_client_to_reclaim(name, princhash, nn))
+			return -EFAULT;
+		return nn->client_tracking_ops->msglen;
+	}
+	return -EFAULT;
+}
+
+static ssize_t
+cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
+{
+	struct cld_upcall *tmp, *cup;
+	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
+	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
+	uint32_t xid;
+	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
+						nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	int16_t status;
+
+	if (mlen != nn->client_tracking_ops->msglen) {
+		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
+			nn->client_tracking_ops->msglen);
+		return -EINVAL;
+	}
+
+	/* copy just the xid so we can try to find that */
+	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
+		dprintk("%s: error when copying xid from userspace", __func__);
+		return -EFAULT;
+	}
+
+	/*
+	 * copy the status so we know whether to remove the upcall from the
+	 * list (for -EINPROGRESS, we just want to make sure the xid is
+	 * valid, not remove the upcall from the list)
+	 */
+	if (get_user(status, &hdr->cm_status)) {
+		dprintk("%s: error when copying status from userspace", __func__);
+		return -EFAULT;
+	}
+
+	/* walk the list and find corresponding xid */
+	cup = NULL;
+	spin_lock(&cn->cn_lock);
+	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
+		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
+			cup = tmp;
+			if (status != -EINPROGRESS)
+				list_del_init(&cup->cu_list);
+			break;
+		}
+	}
+	spin_unlock(&cn->cn_lock);
+
+	/* couldn't find upcall? */
+	if (!cup) {
+		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
+		return -EINVAL;
+	}
+
+	if (status == -EINPROGRESS)
+		return __cld_pipe_inprogress_downcall(cmsg, nn);
+
+	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
+		return -EFAULT;
+
+	complete(&cup->cu_done);
+	return mlen;
+}
+
+static void
+cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct cld_msg *cmsg = msg->data;
+	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
+						 cu_u.cu_msg);
+
+	/* errno >= 0 means we got a downcall */
+	if (msg->errno >= 0)
+		return;
+
+	complete(&cup->cu_done);
+}
+
+static const struct rpc_pipe_ops cld_upcall_ops = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= cld_pipe_downcall,
+	.destroy_msg	= cld_pipe_destroy_msg,
+};
+
+static int
+nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
+{
+	struct dentry *dir;
+	int err;
+
+	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
+	if (dir == NULL)
+		return -ENOENT;
+	err = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
+	dput(dir);
+	return err;
+}
+
+static int
+nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
+{
+	struct super_block *sb;
+	int err;
+
+	sb = rpc_get_sb_net(net);
+	if (!sb)
+		return 0;
+	err = nfsd4_cld_register_sb(sb, pipe);
+	rpc_put_sb_net(net);
+	return err;
+}
+
+static void
+nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
+{
+	struct super_block *sb;
+
+	sb = rpc_get_sb_net(net);
+	if (sb) {
+		rpc_unlink(pipe);
+		rpc_put_sb_net(net);
+	}
+}
+
+/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
+static int
+__nfsd4_init_cld_pipe(struct net *net)
+{
+	int ret;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn;
+
+	if (nn->cld_net)
+		return 0;
+
+	cn = kzalloc_obj(*cn);
+	if (!cn) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(cn->cn_pipe)) {
+		ret = PTR_ERR(cn->cn_pipe);
+		goto err;
+	}
+	spin_lock_init(&cn->cn_lock);
+	INIT_LIST_HEAD(&cn->cn_list);
+
+	ret = nfsd4_cld_register_net(net, cn->cn_pipe);
+	if (unlikely(ret))
+		goto err_destroy_data;
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	cn->cn_has_legacy = false;
+#endif
+	nn->cld_net = cn;
+	return 0;
+
+err_destroy_data:
+	rpc_destroy_pipe_data(cn->cn_pipe);
+err:
+	kfree(cn);
+	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
+			ret);
+	return ret;
+}
+
+static int
+nfsd4_init_cld_pipe(struct net *net)
+{
+	int status;
+
+	status = __nfsd4_init_cld_pipe(net);
+	if (!status)
+		pr_info("NFSD: Using old nfsdcld client tracking operations.\n");
+	return status;
+}
+
+static void
+nfsd4_remove_cld_pipe(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	nfsd4_cld_unregister_net(net, cn->cn_pipe);
+	rpc_destroy_pipe_data(cn->cn_pipe);
+	kfree(nn->cld_net);
+	nn->cld_net = NULL;
+}
+
+static struct cld_upcall *
+alloc_cld_upcall(struct nfsd_net *nn)
+{
+	struct cld_upcall *new, *tmp;
+	struct cld_net *cn = nn->cld_net;
+
+	new = kzalloc_obj(*new);
+	if (!new)
+		return new;
+
+	/* FIXME: hard cap on number in flight? */
+restart_search:
+	spin_lock(&cn->cn_lock);
+	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
+		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
+			cn->cn_xid++;
+			spin_unlock(&cn->cn_lock);
+			goto restart_search;
+		}
+	}
+	init_completion(&new->cu_done);
+	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
+	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
+	new->cu_net = cn;
+	list_add(&new->cu_list, &cn->cn_list);
+	spin_unlock(&cn->cn_lock);
+
+	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
+
+	return new;
+}
+
+static void
+free_cld_upcall(struct cld_upcall *victim)
+{
+	struct cld_net *cn = victim->cu_net;
+
+	spin_lock(&cn->cn_lock);
+	list_del(&victim->cu_list);
+	spin_unlock(&cn->cn_lock);
+	kfree(victim);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_create(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if it's already stored */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to create client "
+				"record on stable storage: %d\n", ret);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_create_v2(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	struct cld_msg_v2 *cmsg;
+	char *principal = NULL;
+
+	/* Don't upcall if it's already stored */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cmsg = &cup->cu_u.cu_msg_v2;
+	cmsg->cm_cmd = Cld_Create;
+	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
+	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+	if (clp->cl_cred.cr_raw_principal)
+		principal = clp->cl_cred.cr_raw_principal;
+	else if (clp->cl_cred.cr_principal)
+		principal = clp->cl_cred.cr_principal;
+	if (principal) {
+		sha256(principal, strlen(principal),
+		       cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data);
+		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = SHA256_DIGEST_SIZE;
+	} else
+		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
+
+	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
+	if (!ret) {
+		ret = cmsg->cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
+				ret);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_remove(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if it's already removed */
+	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to remove client "
+				"record from stable storage: %d\n", ret);
+}
+
+/*
+ * For older nfsdcld's that do not allow us to "slurp" the clients
+ * from the tracking database during startup.
+ *
+ * Check for presence of a record, and update its timestamp
+ */
+static int
+nfsd4_cld_check_v0(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if one was already stored during this grace pd */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		printk(KERN_ERR "NFSD: Unable to check client record on "
+				"stable storage: %d\n", -ENOMEM);
+		return -ENOMEM;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+	return ret;
+}
+
+/*
+ * For newer nfsdcld's that allow us to "slurp" the clients
+ * from the tracking database during startup.
+ *
+ * Check for presence of a record in the reclaim_str_hashtbl
+ */
+static int
+nfsd4_cld_check(struct nfs4_client *clp)
+{
+	struct nfs4_client_reclaim *crp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	/* look for it in the reclaim hashtable otherwise */
+	down_read(&nn->reclaim_str_hashtbl_lock);
+	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
+	if (crp)
+		goto found;
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	if (nn->cld_net->cn_has_legacy) {
+		char dname[HEXDIR_LEN];
+		struct xdr_netobj name;
+
+		nfs4_make_rec_clidname(dname, &clp->cl_name);
+
+		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+		if (!name.data) {
+			dprintk("%s: failed to allocate memory for name.data!\n",
+				__func__);
+			up_read(&nn->reclaim_str_hashtbl_lock);
+			return -ENOENT;
+		}
+		name.len = HEXDIR_LEN;
+		crp = nfsd4_find_reclaim_client(name, nn);
+		kfree(name.data);
+		if (crp)
+			goto found;
+
+	}
+#endif
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	return -ENOENT;
+found:
+	crp->cr_clp = clp;
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	return 0;
+}
+
+static int
+nfsd4_cld_check_v2(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	struct cld_net *cn = nn->cld_net;
+#endif
+	struct nfs4_client_reclaim *crp;
+	unsigned int princhashlen;
+	char *principal = NULL;
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	/* look for it in the reclaim hashtable otherwise */
+	down_read(&nn->reclaim_str_hashtbl_lock);
+	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
+	if (crp)
+		goto found;
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	if (cn->cn_has_legacy) {
+		struct xdr_netobj name;
+		char dname[HEXDIR_LEN];
+
+		nfs4_make_rec_clidname(dname, &clp->cl_name);
+
+		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+		if (!name.data) {
+			dprintk("%s: failed to allocate memory for name.data\n",
+					__func__);
+			up_read(&nn->reclaim_str_hashtbl_lock);
+			return -ENOENT;
+		}
+		name.len = HEXDIR_LEN;
+		crp = nfsd4_find_reclaim_client(name, nn);
+		kfree(name.data);
+		if (crp)
+			goto found;
+
+	}
+#endif
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	return -ENOENT;
+found:
+	princhashlen = crp->cr_princhash.len;
+	if (princhashlen) {
+		u8 digest[SHA256_DIGEST_SIZE];
+		u8 *pdata;
+
+		if (clp->cl_cred.cr_raw_principal)
+			principal = clp->cl_cred.cr_raw_principal;
+		else if (clp->cl_cred.cr_principal)
+			principal = clp->cl_cred.cr_principal;
+		if (principal == NULL) {
+			up_read(&nn->reclaim_str_hashtbl_lock);
+			return -ENOENT;
+		}
+		sha256(principal, strlen(principal), digest);
+		pdata = crp->cr_princhash.data;
+		if (memcmp(pdata, digest, princhashlen)) {
+			up_read(&nn->reclaim_str_hashtbl_lock);
+			return -ENOENT;
+		}
+	}
+	crp->cr_clp = clp;
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	return 0;
+}
+
+static int
+nfsd4_cld_grace_start(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		dprintk("%s: Unable to get clients from userspace: %d\n",
+			__func__, ret);
+	return ret;
+}
+
+/* For older nfsdcld's that need cm_gracetime */
+static void
+nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
+}
+
+/*
+ * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
+ * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
+ */
+static void
+nfsd4_cld_grace_done(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	nfs4_release_reclaim(nn);
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
+}
+
+static int
+nfs4_cld_state_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->reclaim_str_hashtbl = kmalloc_objs(struct list_head,
+					       CLIENT_HASH_SIZE);
+	if (!nn->reclaim_str_hashtbl)
+		return -ENOMEM;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
+	nn->reclaim_str_hashtbl_size = 0;
+	init_rwsem(&nn->reclaim_str_hashtbl_lock);
+	set_bit(NFSD_NET_TRACK_RECLAIM_COMPLETES, &nn->flags);
+	atomic_set(&nn->nr_reclaim_complete, 0);
+
+	return 0;
+}
+
+static void
+nfs4_cld_state_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	clear_bit(NFSD_NET_TRACK_RECLAIM_COMPLETES, &nn->flags);
+	kfree(nn->reclaim_str_hashtbl);
+}
+
+static bool
+cld_running(struct nfsd_net *nn)
+{
+	struct cld_net *cn = nn->cld_net;
+	struct rpc_pipe *pipe = cn->cn_pipe;
+
+	return pipe->nreaders || pipe->nwriters;
+}
+
+static int
+nfsd4_cld_get_version(struct nfsd_net *nn)
+{
+	int ret = 0;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+	uint8_t version;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		if (ret)
+			goto out_free;
+		version = cup->cu_u.cu_msg.cm_u.cm_version;
+		dprintk("%s: userspace returned version %u\n",
+				__func__, version);
+		if (version < 1)
+			version = 1;
+		else if (version > CLD_UPCALL_VERSION)
+			version = CLD_UPCALL_VERSION;
+
+		switch (version) {
+		case 1:
+			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
+			break;
+		case 2:
+			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
+			break;
+		default:
+			break;
+		}
+	}
+out_free:
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		dprintk("%s: Unable to get version from userspace: %d\n",
+			__func__, ret);
+	return ret;
+}
+
+static int
+nfsd4_cld_tracking_init(struct net *net)
+{
+	int status;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	bool running;
+	int retries = 10;
+
+	status = nfs4_cld_state_init(net);
+	if (status)
+		return status;
+
+	status = __nfsd4_init_cld_pipe(net);
+	if (status)
+		goto err_shutdown;
+
+	/*
+	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
+	 * queue an upcall unless we know that nfsdcld is running (because we
+	 * want this to fail fast so that nfsd4_client_tracking_init() can try
+	 * the next client tracking method).  nfsdcld should already be running
+	 * before nfsd is started, so the wait here is for nfsdcld to open the
+	 * pipefs file we just created.
+	 */
+	while (!(running = cld_running(nn)) && retries--)
+		msleep(100);
+
+	if (!running) {
+		status = -ETIMEDOUT;
+		goto err_remove;
+	}
+
+	status = nfsd4_cld_get_version(nn);
+	if (status == -EOPNOTSUPP)
+		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
+
+	status = nfsd4_cld_grace_start(nn);
+	if (status) {
+		if (status == -EOPNOTSUPP)
+			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
+		nfs4_release_reclaim(nn);
+		goto err_remove;
+	} else
+		pr_info("NFSD: Using nfsdcld client tracking operations.\n");
+	return 0;
+
+err_remove:
+	nfsd4_remove_cld_pipe(net);
+err_shutdown:
+	nfs4_cld_state_shutdown(net);
+	return status;
+}
+
+static void
+nfsd4_cld_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs4_release_reclaim(nn);
+	nfsd4_remove_cld_pipe(net);
+	nfs4_cld_state_shutdown(net);
+}
+
+/* For older nfsdcld's */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
+	.init		= nfsd4_init_cld_pipe,
+	.exit		= nfsd4_remove_cld_pipe,
+	.create		= nfsd4_cld_create,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check_v0,
+	.grace_done	= nfsd4_cld_grace_done_v0,
+	.version	= 1,
+	.msglen		= sizeof(struct cld_msg),
+};
+
+/* For newer nfsdcld's */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
+	.init		= nfsd4_cld_tracking_init,
+	.exit		= nfsd4_cld_tracking_exit,
+	.create		= nfsd4_cld_create,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check,
+	.grace_done	= nfsd4_cld_grace_done,
+	.version	= 1,
+	.msglen		= sizeof(struct cld_msg),
+};
+
+/* v2 create/check ops include the principal, if available */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
+	.init		= nfsd4_cld_tracking_init,
+	.exit		= nfsd4_cld_tracking_exit,
+	.create		= nfsd4_cld_create_v2,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check_v2,
+	.grace_done	= nfsd4_cld_grace_done,
+	.version	= 2,
+	.msglen		= sizeof(struct cld_msg_v2),
+};
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+/* upcall via usermodehelper */
+static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
+module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
+			S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
+
+static bool cltrack_legacy_disable;
+module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cltrack_legacy_disable,
+		"Disable legacy recoverydir conversion. Default: false");
+
+#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
+#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
+#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
+#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
+
+static char *
+nfsd4_cltrack_legacy_topdir(void)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	if (cltrack_legacy_disable)
+		return NULL;
+
+	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
+		strlen(nfs4_recoverydir()) + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
+				nfs4_recoverydir());
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	if (cltrack_legacy_disable)
+		return NULL;
+
+	/* +1 is for '/' between "topdir" and "recdir" */
+	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
+		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
+				nfs4_recoverydir());
+	if (copied > (len - HEXDIR_LEN)) {
+		/* just return nothing if output will be truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	nfs4_make_rec_clidname(result + copied, name);
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	/* prefix + Y/N character + terminating NULL */
+	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
+				clp->cl_minorversion ? 'Y' : 'N');
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_grace_start(time64_t grace_start)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	/* prefix + max width of int64_t string + terminating NULL */
+	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
+				grace_start);
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static int
+nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
+{
+	char *envp[3];
+	char *argv[4];
+	int ret;
+
+	if (unlikely(!cltrack_prog[0])) {
+		dprintk("%s: cltrack_prog is disabled\n", __func__);
+		return -EACCES;
+	}
+
+	dprintk("%s: cmd: %s\n", __func__, cmd);
+	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
+	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
+	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
+
+	envp[0] = env0;
+	envp[1] = env1;
+	envp[2] = NULL;
+
+	argv[0] = (char *)cltrack_prog;
+	argv[1] = cmd;
+	argv[2] = arg;
+	argv[3] = NULL;
+
+	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+	/*
+	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
+	 * error. The admin can re-enable it on the fly by using sysfs
+	 * once the problem has been fixed.
+	 */
+	if (ret == -ENOENT || ret == -EACCES) {
+		dprintk("NFSD: %s was not found or isn't executable (%d). "
+			"Setting cltrack_prog to blank string!",
+			cltrack_prog, ret);
+		cltrack_prog[0] = '\0';
+	}
+	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
+
+	return ret;
+}
+
+static char *
+bin_to_hex_dup(const unsigned char *src, int srclen)
+{
+	char *buf;
+
+	/* +1 for terminating NULL */
+	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
+	if (!buf)
+		return buf;
+
+	bin2hex(buf, src, srclen);
+	return buf;
+}
+
+static int
+nfsd4_umh_cltrack_init(struct net *net)
+{
+	int ret;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
+
+	/* XXX: The usermode helper s not working in container yet. */
+	if (net != &init_net) {
+		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
+		kfree(grace_start);
+		return -EINVAL;
+	}
+
+	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
+	kfree(grace_start);
+	if (!ret)
+		pr_info("NFSD: Using UMH upcall client tracking operations.\n");
+	return ret;
+}
+
+static void
+nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
+{
+	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
+			 TASK_UNINTERRUPTIBLE);
+}
+
+static void
+nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
+{
+	clear_and_wake_up_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
+}
+
+static void
+nfsd4_umh_cltrack_create(struct nfs4_client *clp)
+{
+	char *hexid, *has_session, *grace_start;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	/*
+	 * With v4.0 clients, there's little difference in outcome between a
+	 * create and check operation, and we can end up calling into this
+	 * function multiple times per client (once for each openowner). So,
+	 * for v4.0 clients skip upcalling once the client has been recorded
+	 * on stable storage.
+	 *
+	 * For v4.1+ clients, the outcome of the two operations is different,
+	 * so we must ensure that we upcall for the create operation. v4.1+
+	 * clients call this on RECLAIM_COMPLETE though, so we should only end
+	 * up doing a single create upcall per client.
+	 */
+	if (clp->cl_minorversion == 0 &&
+	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return;
+	}
+
+	has_session = nfsd4_cltrack_client_has_session(clp);
+	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	nfsd4_cltrack_upcall_unlock(clp);
+
+	kfree(has_session);
+	kfree(grace_start);
+	kfree(hexid);
+}
+
+static void
+nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
+{
+	char *hexid;
+
+	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return;
+	}
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
+	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
+		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	nfsd4_cltrack_upcall_unlock(clp);
+
+	kfree(hexid);
+}
+
+static int
+nfsd4_umh_cltrack_check(struct nfs4_client *clp)
+{
+	int ret;
+	char *hexid, *has_session, *legacy;
+
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return -ENOMEM;
+	}
+
+	has_session = nfsd4_cltrack_client_has_session(clp);
+	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
+		ret = 0;
+	} else {
+		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
+		if (ret == 0)
+			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+	nfsd4_cltrack_upcall_unlock(clp);
+	kfree(has_session);
+	kfree(legacy);
+	kfree(hexid);
+
+	return ret;
+}
+
+static void
+nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
+{
+	char *legacy;
+	char timestr[22]; /* FIXME: better way to determine max size? */
+
+	sprintf(timestr, "%lld", nn->boot_time);
+	legacy = nfsd4_cltrack_legacy_topdir();
+	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
+	kfree(legacy);
+}
+
+static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
+	.init		= nfsd4_umh_cltrack_init,
+	.exit		= NULL,
+	.create		= nfsd4_umh_cltrack_create,
+	.remove		= nfsd4_umh_cltrack_remove,
+	.check		= nfsd4_umh_cltrack_check,
+	.grace_done	= nfsd4_umh_cltrack_grace_done,
+	.version	= 1,
+	.msglen		= 0,
+};
+
+static inline int check_for_legacy_methods(int status, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct path path;
+
+	/*
+	 * Next, try the UMH upcall.
+	 */
+	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
+	status = nn->client_tracking_ops->init(net);
+	if (!status)
+		return status;
+
+	/*
+	 * Finally, See if the recoverydir exists and is a directory.
+	 * If it is, then use the legacy ops.
+	 */
+	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
+	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
+	if (!status) {
+		status = !d_is_dir(path.dentry);
+		path_put(&path);
+		if (status)
+			return -ENOTDIR;
+	}
+	return status;
+}
+#else
+static inline int check_for_legacy_methods(int status, struct net *net)
+{
+	return status;
+}
+#endif /* CONFIG_LEGACY_NFSD_CLIENT_TRACKING */
+
+int
+nfsd4_client_tracking_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int status;
+
+	/* just run the init if it the method is already decided */
+	if (nn->client_tracking_ops)
+		goto do_init;
+
+	/* First, try to use nfsdcld */
+	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
+	status = nn->client_tracking_ops->init(net);
+	if (!status)
+		return status;
+	if (status != -ETIMEDOUT) {
+		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
+		status = nn->client_tracking_ops->init(net);
+		if (!status)
+			return status;
+	}
+
+	status = check_for_legacy_methods(status, net);
+	if (status)
+		goto out;
+do_init:
+	status = nn->client_tracking_ops->init(net);
+out:
+	if (status) {
+		pr_warn("NFSD: Unable to initialize client recovery tracking! (%d)\n", status);
+		pr_warn("NFSD: Is nfsdcld running? If not, enable CONFIG_NFSD_LEGACY_CLIENT_TRACKING.\n");
+		nn->client_tracking_ops = NULL;
+	}
+	return status;
+}
+
+void
+nfsd4_client_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->client_tracking_ops) {
+		if (nn->client_tracking_ops->exit)
+			nn->client_tracking_ops->exit(net);
+		nn->client_tracking_ops = NULL;
+	}
+}
+
+void
+nfsd4_client_record_create(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->create(clp);
+}
+
+void
+nfsd4_client_record_remove(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->remove(clp);
+}
+
+int
+nfsd4_client_record_check(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		return nn->client_tracking_ops->check(clp);
+
+	return -EOPNOTSUPP;
+}
+
+void
+nfsd4_record_grace_done(struct nfsd_net *nn)
+{
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->grace_done(nn);
+}
+
+static int
+rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	int ret = 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	if (!cn) {
+		module_put(THIS_MODULE);
+		return 0;
+	}
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		ret = nfsd4_cld_register_sb(sb, cn->cn_pipe);
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		rpc_unlink(cn->cn_pipe);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfsd4_cld_block = {
+	.notifier_call = rpc_pipefs_event,
+};
+
+int
+register_cld_notifier(void)
+{
+	WARN_ON(!nfsd_net_id);
+	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
+}
+
+void
+unregister_cld_notifier(void)
+{
+	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
+}
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
new file mode 100644
index 000000000..9c4adf311
--- /dev/null
+++ b/fs/nfsd/nfs4state.c
@@ -0,0 +1,10555 @@
+/*
+*  Copyright (c) 2001 The Regents of the University of Michigan.
+*  All rights reserved.
+*
+*  Kendrick Smith <kmsmith@umich.edu>
+*  Andy Adamson <kandros@umich.edu>
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions
+*  are met:
+*
+*  1. Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*  2. Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in the
+*     documentation and/or other materials provided with the distribution.
+*  3. Neither the name of the University nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+*/
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/ratelimit.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/jhash.h>
+#include <linux/string_helpers.h>
+#include <linux/fsnotify.h>
+#include <linux/rhashtable.h>
+#include <linux/nfs_ssc.h>
+
+#include "xdr4.h"
+#include "xdr4cb.h"
+#include "vfs.h"
+#include "current_stateid.h"
+#include "stats.h"
+
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "nfs4xdr_gen.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+#define all_ones {{ ~0, ~0}, ~0}
+static const stateid_t one_stateid = {
+	.si_generation = ~0,
+	.si_opaque = all_ones,
+};
+static const stateid_t zero_stateid = {
+	/* all fields zero */
+};
+static const stateid_t currentstateid = {
+	.si_generation = 1,
+};
+static const stateid_t close_stateid = {
+	.si_generation = 0xffffffffU,
+};
+
+static u64 current_sessionid = 1;
+
+bool nfsd_delegts_enabled __read_mostly = true;
+
+#define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(stateid_t)))
+#define ONE_STATEID(stateid)  (!memcmp((stateid), &one_stateid, sizeof(stateid_t)))
+#define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
+#define CLOSE_STATEID(stateid)  (!memcmp((stateid), &close_stateid, sizeof(stateid_t)))
+
+/* forward declarations */
+static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
+static void nfs4_free_ol_stateid(struct nfs4_stid *stid);
+static void nfsd4_end_grace(struct nfsd_net *nn);
+static void _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps);
+static void nfsd4_file_hash_remove(struct nfs4_file *fi);
+static void deleg_reaper(struct nfsd_net *nn);
+
+static const struct lease_manager_operations nfsd_lease_mng_ops;
+
+/* Locking: */
+
+enum nfsd4_st_mutex_lock_subclass {
+	OPEN_STATEID_MUTEX = 0,
+	LOCK_STATEID_MUTEX = 1,
+};
+
+/*
+ * A waitqueue for all in-progress 4.0 CLOSE operations that are waiting for
+ * the refcount on the open stateid to drop.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(close_wq);
+
+/*
+ * A waitqueue where a writer to clients/#/ctl destroying a client can
+ * wait for cl_rpc_users to drop to 0 and then for the client to be
+ * unhashed.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(expiry_wq);
+
+static struct kmem_cache *client_slab;
+static struct kmem_cache *openowner_slab;
+static struct kmem_cache *lockowner_slab;
+static struct kmem_cache *file_slab;
+static struct kmem_cache *stateid_slab;
+static struct kmem_cache *deleg_slab;
+static struct kmem_cache *odstate_slab;
+static struct kmem_cache *async_copy_slab;
+
+static void free_session(struct nfsd4_session *);
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_ops;
+static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops;
+static const struct nfsd4_callback_ops nfsd4_cb_getattr_ops;
+static const struct nfsd4_callback_ops nfsd4_cb_notify_ops;
+
+static struct workqueue_struct *laundry_wq;
+
+int nfsd4_create_laundry_wq(void)
+{
+	int rc = 0;
+
+	laundry_wq = alloc_workqueue("%s", WQ_UNBOUND, 0, "nfsd4");
+	if (laundry_wq == NULL)
+		rc = -ENOMEM;
+	return rc;
+}
+
+void nfsd4_destroy_laundry_wq(void)
+{
+	destroy_workqueue(laundry_wq);
+}
+
+static bool is_session_dead(struct nfsd4_session *ses)
+{
+	return ses->se_dead;
+}
+
+static __be32 mark_session_dead_locked(struct nfsd4_session *ses, int ref_held_by_me)
+{
+	if (atomic_read(&ses->se_ref) > ref_held_by_me)
+		return nfserr_jukebox;
+	ses->se_dead = true;
+	return nfs_ok;
+}
+
+static bool is_client_expired(struct nfs4_client *clp)
+{
+	return clp->cl_time == 0;
+}
+
+static void nfsd4_dec_courtesy_client_count(struct nfsd_net *nn,
+					struct nfs4_client *clp)
+{
+	if (clp->cl_state != NFSD4_ACTIVE)
+		atomic_add_unless(&nn->nfsd_courtesy_clients, -1, 0);
+}
+
+static __be32 get_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (is_client_expired(clp))
+		return nfserr_expired;
+	atomic_inc(&clp->cl_rpc_users);
+	nfsd4_dec_courtesy_client_count(nn, clp);
+	clp->cl_state = NFSD4_ACTIVE;
+	return nfs_ok;
+}
+
+/* must be called under the client_lock */
+static inline void
+renew_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (is_client_expired(clp)) {
+		WARN_ON(1);
+		printk("%s: client (clientid %08x/%08x) already expired\n",
+			__func__,
+			clp->cl_clientid.cl_boot,
+			clp->cl_clientid.cl_id);
+		return;
+	}
+
+	list_move_tail(&clp->cl_lru, &nn->client_lru);
+	clp->cl_time = ktime_get_boottime_seconds();
+	nfsd4_dec_courtesy_client_count(nn, clp);
+	clp->cl_state = NFSD4_ACTIVE;
+}
+
+/*
+ * Finish a cl_rpc_users unpin with the client_lock held. A
+ * revocation walk clears @renew so the client whose state it is
+ * revoking is not revived; every other caller renews the lease of
+ * a still-active client.
+ */
+static void __put_client_locked(struct nfs4_client *clp, bool renew)
+{
+	if (is_client_expired(clp))
+		wake_up_all(&expiry_wq);
+	else if (renew)
+		renew_client_locked(clp);
+}
+
+static void put_client_renew_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (atomic_dec_and_test(&clp->cl_rpc_users))
+		__put_client_locked(clp, true);
+}
+
+static void put_client_renew(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!atomic_dec_and_lock(&clp->cl_rpc_users, &nn->client_lock))
+		return;
+	__put_client_locked(clp, true);
+	spin_unlock(&nn->client_lock);
+}
+
+static void put_client_no_renew_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (atomic_dec_and_test(&clp->cl_rpc_users))
+		__put_client_locked(clp, false);
+}
+
+static void put_client_no_renew(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!atomic_dec_and_lock(&clp->cl_rpc_users, &nn->client_lock))
+		return;
+	__put_client_locked(clp, false);
+	spin_unlock(&nn->client_lock);
+}
+
+static __be32 nfsd4_get_session_locked(struct nfsd4_session *ses)
+{
+	__be32 status;
+
+	if (is_session_dead(ses))
+		return nfserr_badsession;
+	status = get_client_locked(ses->se_client);
+	if (status)
+		return status;
+	atomic_inc(&ses->se_ref);
+	return nfs_ok;
+}
+
+static void nfsd4_put_session_locked(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (atomic_dec_and_test(&ses->se_ref) && is_session_dead(ses))
+		free_session(ses);
+	put_client_renew_locked(clp);
+}
+
+static void nfsd4_put_session(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	nfsd4_put_session_locked(ses);
+	spin_unlock(&nn->client_lock);
+}
+
+static struct nfsd4_blocked_lock *
+find_blocked_lock(struct nfs4_lockowner *lo, struct knfsd_fh *fh,
+			struct nfsd_net *nn)
+{
+	struct nfsd4_blocked_lock *cur, *found = NULL;
+
+	spin_lock(&nn->blocked_locks_lock);
+	list_for_each_entry(cur, &lo->lo_blocked, nbl_list) {
+		if (fh_match(fh, &cur->nbl_fh)) {
+			list_del_init(&cur->nbl_list);
+			WARN_ON(list_empty(&cur->nbl_lru));
+			list_del_init(&cur->nbl_lru);
+			found = cur;
+			break;
+		}
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+	if (found)
+		locks_delete_block(&found->nbl_lock);
+	return found;
+}
+
+static struct nfsd4_blocked_lock *
+find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh,
+			struct nfsd_net *nn)
+{
+	struct nfsd4_blocked_lock *nbl;
+
+	nbl = find_blocked_lock(lo, fh, nn);
+	if (!nbl) {
+		nbl = kmalloc_obj(*nbl);
+		if (nbl) {
+			INIT_LIST_HEAD(&nbl->nbl_list);
+			INIT_LIST_HEAD(&nbl->nbl_lru);
+			fh_copy_shallow(&nbl->nbl_fh, fh);
+			locks_init_lock(&nbl->nbl_lock);
+			kref_init(&nbl->nbl_kref);
+			nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client,
+					&nfsd4_cb_notify_lock_ops,
+					NFSPROC4_CLNT_CB_NOTIFY_LOCK);
+		}
+	}
+	return nbl;
+}
+
+static void
+free_nbl(struct kref *kref)
+{
+	struct nfsd4_blocked_lock *nbl;
+
+	nbl = container_of(kref, struct nfsd4_blocked_lock, nbl_kref);
+	locks_release_private(&nbl->nbl_lock);
+	kfree(nbl);
+}
+
+static void
+free_blocked_lock(struct nfsd4_blocked_lock *nbl)
+{
+	locks_delete_block(&nbl->nbl_lock);
+	kref_put(&nbl->nbl_kref, free_nbl);
+}
+
+/* A blocked lock's flc_owner is its nfs4_lockowner. */
+static struct nfs4_client *
+nbl_client(struct nfsd4_blocked_lock *nbl)
+{
+	struct nfs4_lockowner *lo;
+
+	lo = (struct nfs4_lockowner *)nbl->nbl_lock.c.flc_owner;
+	return lo->lo_owner.so_client;
+}
+
+static void
+remove_blocked_locks(struct nfs4_lockowner *lo)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfsd4_blocked_lock *nbl;
+	LIST_HEAD(reaplist);
+
+	/* Dequeue all blocked locks */
+	spin_lock(&nn->blocked_locks_lock);
+	while (!list_empty(&lo->lo_blocked)) {
+		nbl = list_first_entry(&lo->lo_blocked,
+					struct nfsd4_blocked_lock,
+					nbl_list);
+		list_del_init(&nbl->nbl_list);
+		WARN_ON(list_empty(&nbl->nbl_lru));
+		list_move(&nbl->nbl_lru, &reaplist);
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+
+	/* Now free them */
+	while (!list_empty(&reaplist)) {
+		nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock,
+					nbl_lru);
+		list_del_init(&nbl->nbl_lru);
+		free_blocked_lock(nbl);
+	}
+}
+
+static bool
+nfsd4_cb_notify_lock_prepare(struct nfsd4_callback *cb)
+{
+	struct nfsd4_blocked_lock	*nbl = container_of(cb,
+						struct nfsd4_blocked_lock, nbl_cb);
+	locks_delete_block(&nbl->nbl_lock);
+	return true;
+}
+
+static int
+nfsd4_cb_notify_lock_done(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	trace_nfsd_cb_notify_lock_done(&zero_stateid, task);
+
+	/*
+	 * Since this is just an optimization, we don't try very hard if it
+	 * turns out not to succeed. We'll requeue it on NFS4ERR_DELAY, and
+	 * just quit trying on anything else.
+	 */
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 1 * HZ);
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_blocked_lock	*nbl = container_of(cb,
+						struct nfsd4_blocked_lock, nbl_cb);
+
+	free_blocked_lock(nbl);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = {
+	.prepare	= nfsd4_cb_notify_lock_prepare,
+	.done		= nfsd4_cb_notify_lock_done,
+	.release	= nfsd4_cb_notify_lock_release,
+	.opcode		= OP_CB_NOTIFY_LOCK,
+};
+
+/*
+ * We store the NONE, READ, WRITE, and BOTH bits separately in the
+ * st_{access,deny}_bmap field of the stateid, in order to track not
+ * only what share bits are currently in force, but also what
+ * combinations of share bits previous opens have used.  This allows us
+ * to enforce the recommendation in
+ * https://datatracker.ietf.org/doc/html/rfc7530#section-16.19.4 that
+ * the server return an error if the client attempt to downgrade to a
+ * combination of share bits not explicable by closing some of its
+ * previous opens.
+ *
+ * This enforcement is arguably incomplete, since we don't keep
+ * track of access/deny bit combinations; so, e.g., we allow:
+ *
+ *	OPEN allow read, deny write
+ *	OPEN allow both, deny none
+ *	DOWNGRADE allow read, deny none
+ *
+ * which we should reject.
+ *
+ * But you could also argue that our current code is already overkill,
+ * since it only exists to return NFS4ERR_INVAL on incorrect client
+ * behavior.
+ */
+static unsigned int
+bmap_to_share_mode(unsigned long bmap)
+{
+	int i;
+	unsigned int access = 0;
+
+	for (i = 1; i < 4; i++) {
+		if (test_bit(i, &bmap))
+			access |= i;
+	}
+	return access;
+}
+
+/* set share access for a given stateid */
+static inline void
+set_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
+	stp->st_access_bmap |= mask;
+}
+
+/* clear share access for a given stateid */
+static inline void
+clear_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
+	stp->st_access_bmap &= ~mask;
+}
+
+/* test whether a given stateid has access */
+static inline bool
+test_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	return (bool)(stp->st_access_bmap & mask);
+}
+
+/* set share deny for a given stateid */
+static inline void
+set_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
+	stp->st_deny_bmap |= mask;
+}
+
+/* clear share deny for a given stateid */
+static inline void
+clear_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
+	stp->st_deny_bmap &= ~mask;
+}
+
+/* test whether a given stateid is denying specific access */
+static inline bool
+test_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	return (bool)(stp->st_deny_bmap & mask);
+}
+
+static int nfs4_access_to_omode(u32 access)
+{
+	switch (access & NFS4_SHARE_ACCESS_BOTH) {
+	case NFS4_SHARE_ACCESS_READ:
+		return O_RDONLY;
+	case NFS4_SHARE_ACCESS_WRITE:
+		return O_WRONLY;
+	case NFS4_SHARE_ACCESS_BOTH:
+		return O_RDWR;
+	}
+	WARN_ON_ONCE(1);
+	return O_RDONLY;
+}
+
+static inline int
+access_permit_read(struct nfs4_ol_stateid *stp)
+{
+	return test_access(NFS4_SHARE_ACCESS_READ, stp) ||
+		test_access(NFS4_SHARE_ACCESS_BOTH, stp) ||
+		test_access(NFS4_SHARE_ACCESS_WRITE, stp);
+}
+
+static inline int
+access_permit_write(struct nfs4_ol_stateid *stp)
+{
+	return test_access(NFS4_SHARE_ACCESS_WRITE, stp) ||
+		test_access(NFS4_SHARE_ACCESS_BOTH, stp);
+}
+
+static inline struct nfs4_stateowner *
+nfs4_get_stateowner(struct nfs4_stateowner *sop)
+{
+	atomic_inc(&sop->so_count);
+	return sop;
+}
+
+static int
+same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner)
+{
+	return (sop->so_owner.len == owner->len) &&
+		0 == memcmp(sop->so_owner.data, owner->data, owner->len);
+}
+
+static struct nfs4_openowner *
+find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
+			struct nfs4_client *clp)
+{
+	struct nfs4_stateowner *so;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[hashval],
+			    so_strhash) {
+		if (!so->so_is_open_owner)
+			continue;
+		if (same_owner_str(so, &open->op_owner))
+			return openowner(nfs4_get_stateowner(so));
+	}
+	return NULL;
+}
+
+static inline u32
+opaque_hashval(const void *ptr, int nbytes)
+{
+	unsigned char *cptr = (unsigned char *) ptr;
+
+	u32 x = 0;
+	while (nbytes--) {
+		x *= 37;
+		x += *cptr++;
+	}
+	return x;
+}
+
+void
+put_nfs4_file(struct nfs4_file *fi)
+{
+	if (refcount_dec_and_test(&fi->fi_ref)) {
+		nfsd4_file_hash_remove(fi);
+		WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate));
+		WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
+		kfree_rcu(fi, fi_rcu);
+	}
+}
+
+static struct nfsd_file *
+find_writeable_file_locked(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	lockdep_assert_held(&f->fi_lock);
+
+	ret = nfsd_file_get(f->fi_fds[O_WRONLY]);
+	if (!ret)
+		ret = nfsd_file_get(f->fi_fds[O_RDWR]);
+	return ret;
+}
+
+static struct nfsd_file *
+find_writeable_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	spin_lock(&f->fi_lock);
+	ret = find_writeable_file_locked(f);
+	spin_unlock(&f->fi_lock);
+
+	return ret;
+}
+
+static struct nfsd_file *
+find_readable_file_locked(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	lockdep_assert_held(&f->fi_lock);
+
+	ret = nfsd_file_get(f->fi_fds[O_RDONLY]);
+	if (!ret)
+		ret = nfsd_file_get(f->fi_fds[O_RDWR]);
+	return ret;
+}
+
+static struct nfsd_file *
+find_readable_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	spin_lock(&f->fi_lock);
+	ret = find_readable_file_locked(f);
+	spin_unlock(&f->fi_lock);
+
+	return ret;
+}
+
+struct nfsd_file *
+find_any_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	if (!f)
+		return NULL;
+	spin_lock(&f->fi_lock);
+	ret = nfsd_file_get(f->fi_fds[O_RDWR]);
+	if (!ret) {
+		ret = nfsd_file_get(f->fi_fds[O_WRONLY]);
+		if (!ret)
+			ret = nfsd_file_get(f->fi_fds[O_RDONLY]);
+	}
+	spin_unlock(&f->fi_lock);
+	return ret;
+}
+
+static struct nfsd_file *find_any_file_locked(struct nfs4_file *f)
+{
+	lockdep_assert_held(&f->fi_lock);
+
+	if (f->fi_fds[O_RDWR])
+		return f->fi_fds[O_RDWR];
+	if (f->fi_fds[O_WRONLY])
+		return f->fi_fds[O_WRONLY];
+	if (f->fi_fds[O_RDONLY])
+		return f->fi_fds[O_RDONLY];
+	return NULL;
+}
+
+static atomic_long_t num_delegations;
+unsigned long max_delegations;
+
+/*
+ * Open owner state (share locks)
+ */
+
+/* hash tables for lock and open owners */
+#define OWNER_HASH_BITS              8
+#define OWNER_HASH_SIZE             (1 << OWNER_HASH_BITS)
+#define OWNER_HASH_MASK             (OWNER_HASH_SIZE - 1)
+
+static unsigned int ownerstr_hashval(struct xdr_netobj *ownername)
+{
+	unsigned int ret;
+
+	ret = opaque_hashval(ownername->data, ownername->len);
+	return ret & OWNER_HASH_MASK;
+}
+
+static struct rhltable nfs4_file_rhltable ____cacheline_aligned_in_smp;
+
+static const struct rhashtable_params nfs4_file_rhash_params = {
+	.key_len		= sizeof_field(struct nfs4_file, fi_inode),
+	.key_offset		= offsetof(struct nfs4_file, fi_inode),
+	.head_offset		= offsetof(struct nfs4_file, fi_rlist),
+
+	/*
+	 * Start with a single page hash table to reduce resizing churn
+	 * on light workloads.
+	 */
+	.min_size		= 256,
+	.automatic_shrinking	= true,
+};
+
+/*
+ * Check if courtesy clients have conflicting access and resolve it if possible
+ *
+ * access:  is op_share_access if share_access is true.
+ *	    Check if access mode, op_share_access, would conflict with
+ *	    the current deny mode of the file 'fp'.
+ * access:  is op_share_deny if share_access is false.
+ *	    Check if the deny mode, op_share_deny, would conflict with
+ *	    current access of the file 'fp'.
+ * stp:     skip checking this entry.
+ * new_stp: normal open, not open upgrade.
+ *
+ * Function returns:
+ *	false - access/deny mode conflict with normal client.
+ *	true  - no conflict or conflict with courtesy client(s) is resolved.
+ */
+static bool
+nfs4_resolve_deny_conflicts_locked(struct nfs4_file *fp, bool new_stp,
+		struct nfs4_ol_stateid *stp, u32 access, bool share_access)
+{
+	struct nfs4_ol_stateid *st;
+	bool resolvable = true;
+	unsigned char bmap;
+	struct nfsd_net *nn;
+	struct nfs4_client *clp;
+
+	lockdep_assert_held(&fp->fi_lock);
+	list_for_each_entry(st, &fp->fi_stateids, st_perfile) {
+		/* ignore lock stateid */
+		if (st->st_openstp)
+			continue;
+		if (st == stp && new_stp)
+			continue;
+		/* check file access against deny mode or vice versa */
+		bmap = share_access ? st->st_deny_bmap : st->st_access_bmap;
+		if (!(access & bmap_to_share_mode(bmap)))
+			continue;
+		clp = st->st_stid.sc_client;
+		if (try_to_expire_client(clp))
+			continue;
+		resolvable = false;
+		break;
+	}
+	if (resolvable) {
+		clp = stp->st_stid.sc_client;
+		nn = net_generic(clp->net, nfsd_net_id);
+		mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+	}
+	return resolvable;
+}
+
+static void
+__nfs4_file_get_access(struct nfs4_file *fp, u32 access)
+{
+	lockdep_assert_held(&fp->fi_lock);
+
+	if (access & NFS4_SHARE_ACCESS_WRITE)
+		atomic_inc(&fp->fi_access[O_WRONLY]);
+	if (access & NFS4_SHARE_ACCESS_READ)
+		atomic_inc(&fp->fi_access[O_RDONLY]);
+}
+
+static __be32
+nfs4_file_get_access(struct nfs4_file *fp, u32 access)
+{
+	lockdep_assert_held(&fp->fi_lock);
+
+	/* Does this access mode make sense? */
+	if (access & ~NFS4_SHARE_ACCESS_BOTH)
+		return nfserr_inval;
+
+	/* Does it conflict with a deny mode already set? */
+	if ((access & fp->fi_share_deny) != 0)
+		return nfserr_share_denied;
+
+	__nfs4_file_get_access(fp, access);
+	return nfs_ok;
+}
+
+static __be32 nfs4_file_check_deny(struct nfs4_file *fp, u32 deny)
+{
+	/* Common case is that there is no deny mode. */
+	if (deny) {
+		/* Does this deny mode make sense? */
+		if (deny & ~NFS4_SHARE_DENY_BOTH)
+			return nfserr_inval;
+
+		if ((deny & NFS4_SHARE_DENY_READ) &&
+		    atomic_read(&fp->fi_access[O_RDONLY]))
+			return nfserr_share_denied;
+
+		if ((deny & NFS4_SHARE_DENY_WRITE) &&
+		    atomic_read(&fp->fi_access[O_WRONLY]))
+			return nfserr_share_denied;
+	}
+	return nfs_ok;
+}
+
+static void __nfs4_file_put_access(struct nfs4_file *fp, int oflag)
+{
+	might_lock(&fp->fi_lock);
+
+	if (atomic_dec_and_lock(&fp->fi_access[oflag], &fp->fi_lock)) {
+		struct nfsd_file *f1 = NULL;
+		struct nfsd_file *f2 = NULL;
+
+		swap(f1, fp->fi_fds[oflag]);
+		if (atomic_read(&fp->fi_access[1 - oflag]) == 0)
+			swap(f2, fp->fi_fds[O_RDWR]);
+		spin_unlock(&fp->fi_lock);
+		if (f1)
+			nfsd_file_put(f1);
+		if (f2)
+			nfsd_file_put(f2);
+	}
+}
+
+static void nfs4_file_put_access(struct nfs4_file *fp, u32 access)
+{
+	WARN_ON_ONCE(access & ~NFS4_SHARE_ACCESS_BOTH);
+
+	if (access & NFS4_SHARE_ACCESS_WRITE)
+		__nfs4_file_put_access(fp, O_WRONLY);
+	if (access & NFS4_SHARE_ACCESS_READ)
+		__nfs4_file_put_access(fp, O_RDONLY);
+}
+
+/*
+ * Allocate a new open/delegation state counter. This is needed for
+ * pNFS for proper return on close semantics.
+ *
+ * Note that we only allocate it for pNFS-enabled exports, otherwise
+ * all pointers to struct nfs4_clnt_odstate are always NULL.
+ */
+static struct nfs4_clnt_odstate *
+alloc_clnt_odstate(struct nfs4_client *clp)
+{
+	struct nfs4_clnt_odstate *co;
+
+	co = kmem_cache_zalloc(odstate_slab, GFP_KERNEL);
+	if (co) {
+		co->co_client = clp;
+		refcount_set(&co->co_odcount, 1);
+	}
+	return co;
+}
+
+static void
+hash_clnt_odstate_locked(struct nfs4_clnt_odstate *co)
+{
+	struct nfs4_file *fp = co->co_file;
+
+	lockdep_assert_held(&fp->fi_lock);
+	list_add(&co->co_perfile, &fp->fi_clnt_odstate);
+}
+
+static inline void
+get_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+	if (co)
+		refcount_inc(&co->co_odcount);
+}
+
+static void
+put_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+	struct nfs4_file *fp;
+
+	if (!co)
+		return;
+
+	fp = co->co_file;
+	if (refcount_dec_and_lock(&co->co_odcount, &fp->fi_lock)) {
+		list_del(&co->co_perfile);
+		spin_unlock(&fp->fi_lock);
+
+		nfsd4_return_all_file_layouts(co->co_client, fp);
+		kmem_cache_free(odstate_slab, co);
+	}
+}
+
+static struct nfs4_clnt_odstate *
+find_or_hash_clnt_odstate(struct nfs4_file *fp, struct nfs4_clnt_odstate *new)
+{
+	struct nfs4_clnt_odstate *co;
+	struct nfs4_client *cl;
+
+	if (!new)
+		return NULL;
+
+	cl = new->co_client;
+
+	spin_lock(&fp->fi_lock);
+	list_for_each_entry(co, &fp->fi_clnt_odstate, co_perfile) {
+		if (co->co_client == cl) {
+			get_clnt_odstate(co);
+			goto out;
+		}
+	}
+	co = new;
+	co->co_file = fp;
+	hash_clnt_odstate_locked(new);
+out:
+	spin_unlock(&fp->fi_lock);
+	return co;
+}
+
+struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
+				  void (*sc_free)(struct nfs4_stid *))
+{
+	struct nfs4_stid *stid;
+	int new_id;
+
+	stid = kmem_cache_zalloc(slab, GFP_KERNEL);
+	if (!stid)
+		return NULL;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&cl->cl_lock);
+	/* Reserving 0 for start of file in nfsdfs "states" file: */
+	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 1, 0, GFP_NOWAIT);
+	spin_unlock(&cl->cl_lock);
+	idr_preload_end();
+	if (new_id < 0)
+		goto out_free;
+
+	stid->sc_free = sc_free;
+	stid->sc_client = cl;
+	stid->sc_stateid.si_opaque.so_id = new_id;
+	stid->sc_stateid.si_opaque.so_clid = cl->cl_clientid;
+	/* Will be incremented before return to client: */
+	refcount_set(&stid->sc_count, 1);
+	spin_lock_init(&stid->sc_lock);
+	INIT_LIST_HEAD(&stid->sc_cp_list);
+
+	return stid;
+out_free:
+	kmem_cache_free(slab, stid);
+	return NULL;
+}
+
+/*
+ * Publish a COPY_NOTIFY stateid in nn->s2s_cp_stateids and link it onto the
+ * parent's sc_cp_list. That IDR holds only COPY_NOTIFY stateids.
+ */
+static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
+			      struct nfs4_stid *p_stid)
+{
+	int new_id;
+
+	stid->cs_stid.si_opaque.so_clid.cl_boot = (u32)nn->boot_time;
+	stid->cs_stid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&nn->s2s_cp_lock);
+	new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, stid, 0, 0, GFP_NOWAIT);
+	if (new_id >= 0) {
+		struct nfs4_cpntf_state *cps =
+			container_of(stid, struct nfs4_cpntf_state, cp_stateid);
+
+		stid->cs_stid.si_opaque.so_id = new_id;
+		stid->cs_stid.si_generation = 1;
+		/*
+		 * Set cs_type and link onto sc_cp_list under the same lock
+		 * that installed the IDR entry, so a concurrent
+		 * manage_cpntf_state() sees either no entry or a fully
+		 * linked cp_list.
+		 */
+		stid->cs_type = NFS4_COPYNOTIFY_STID;
+		list_add(&cps->cp_list, &p_stid->sc_cp_list);
+	}
+	spin_unlock(&nn->s2s_cp_lock);
+	idr_preload_end();
+	if (new_id < 0)
+		return 0;
+	return 1;
+}
+
+/* sc_free for a copy offload stateid; runs from nfs4_put_stid(). */
+static void nfsd4_free_async_copy_stid(struct nfs4_stid *stid)
+{
+	struct nfsd4_async_copy *copy =
+		container_of(stid, struct nfsd4_async_copy, cp_stid);
+
+	if (copy->copy_task)
+		put_task_struct(copy->copy_task);
+	kfree(copy->cp_copy.cp_src);
+	kmem_cache_free(async_copy_slab, copy);
+}
+
+/*
+ * Allocate durable async COPY state. The offload stateid is a first-class
+ * nfs4_stid (SC_TYPE_COPY) in the client's cl_stateids, so it is per-client
+ * and uses the common refcounting/teardown. find_stateid_locked() hides it;
+ * OFFLOAD_CANCEL/OFFLOAD_STATUS find it via clp->async_copies.
+ */
+struct nfsd4_async_copy *nfs4_alloc_copy_stid(struct nfs4_client *clp)
+{
+	struct nfs4_stid *stid;
+
+	stid = nfs4_alloc_stid(clp, async_copy_slab, nfsd4_free_async_copy_stid);
+	if (!stid)
+		return NULL;
+	stid->sc_type = SC_TYPE_COPY;
+	/* RFC 7862 Section 4.8: a copy offload stateid's seqid MUST NOT be 0 */
+	stid->sc_stateid.si_generation = 1;
+	return container_of(stid, struct nfsd4_async_copy, cp_stid);
+}
+
+struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
+						     struct nfs4_stid *p_stid)
+{
+	struct nfs4_cpntf_state *cps;
+
+	cps = kzalloc_obj(struct nfs4_cpntf_state);
+	if (!cps)
+		return NULL;
+	/* So a stale list_del_init() before linking is a no-op. */
+	INIT_LIST_HEAD(&cps->cp_list);
+	cps->cpntf_time = ktime_get_boottime_seconds();
+	/*
+	 * Fully initialize the entry before nfs4_init_cp_state() publishes it,
+	 * since a concurrent OFFLOAD_CANCEL could then free it. Take an extra
+	 * reference for the caller (dropped with nfs4_put_cpntf_state()).
+	 */
+	memcpy(&cps->cp_p_stateid, &p_stid->sc_stateid, sizeof(stateid_t));
+	memcpy(&cps->cp_p_clid, &p_stid->sc_client->cl_clientid,
+	       sizeof(clientid_t));
+	refcount_set(&cps->cp_stateid.cs_count, 2);
+	if (!nfs4_init_cp_state(nn, &cps->cp_stateid, p_stid))
+		goto out_free;
+	return cps;
+out_free:
+	kfree(cps);
+	return NULL;
+}
+
+/*
+ * Drop the parent's reference on an already-unlinked cpntf entry. If a
+ * concurrent holder still owns a reference, its nfs4_put_cpntf_state() does
+ * the final free.
+ *
+ * nn->s2s_cp_lock must be held.
+ */
+static void put_cpntf_state_unlinked_locked(struct nfs4_cpntf_state *cps)
+{
+	WARN_ON_ONCE(cps->cp_stateid.cs_type != NFS4_COPYNOTIFY_STID);
+	WARN_ON_ONCE(!list_empty(&cps->cp_list));
+
+	if (refcount_dec_and_test(&cps->cp_stateid.cs_count))
+		kfree(cps);
+}
+
+/*
+ * Unhash from the IDR and sc_cp_list. Gated on list_empty() to avoid
+ * evicting a recycled so_id.
+ */
+static void nfsd4_unhash_cpntf_state(struct nfsd_net *nn, struct nfs4_cpntf_state *cps)
+{
+	lockdep_assert_held(&nn->s2s_cp_lock);
+
+	if (!list_empty(&cps->cp_list)) {
+		list_del_init(&cps->cp_list);
+		idr_remove(&nn->s2s_cp_stateids, cps->cp_stateid.cs_stid.si_opaque.so_id);
+	}
+}
+
+/*
+ * Revoke a copy-notify stateid: unlink it from the IDR and sc_cp_list first
+ * so no new finder can discover it, then drop the membership reference. Every
+ * revoke path (cancel, laundromat, drain) must use this rather than
+ * _free_cpntf_state_locked(), which unlinks only at refcount zero and so could
+ * let a second revoke free the entry under a concurrent reader.
+ *
+ * nn->s2s_cp_lock must be held.
+ */
+static void revoke_cpntf_state_locked(struct nfsd_net *nn,
+				      struct nfs4_cpntf_state *cps)
+{
+	nfsd4_unhash_cpntf_state(nn, cps);
+	put_cpntf_state_unlinked_locked(cps);
+}
+
+static void nfs4_free_cpntf_statelist(struct net *net, struct nfs4_stid *stid)
+{
+	struct nfs4_cpntf_state *cps, *tmp;
+	struct nfsd_net *nn;
+
+	nn = net_generic(net, nfsd_net_id);
+	spin_lock(&nn->s2s_cp_lock);
+	/*
+	 * Revoke unlinks each entry before dropping the parent's reference, so
+	 * the drain terminates in one pass per entry regardless of cs_count; a
+	 * concurrent holder does the final kfree via nfs4_put_cpntf_state().
+	 */
+	list_for_each_entry_safe(cps, tmp, &stid->sc_cp_list, cp_list)
+		revoke_cpntf_state_locked(nn, cps);
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
+static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp)
+{
+	struct nfs4_stid *stid;
+
+	stid = nfs4_alloc_stid(clp, stateid_slab, nfs4_free_ol_stateid);
+	if (!stid)
+		return NULL;
+
+	return openlockstateid(stid);
+}
+
+/*
+ * As the sc_free callback of deleg, this may be called by nfs4_put_stid
+ * in nfsd_break_one_deleg.
+ * Considering nfsd_break_one_deleg is called with the flc->flc_lock held,
+ * this function mustn't ever sleep.
+ */
+static void nfs4_free_deleg(struct nfs4_stid *stid)
+{
+	struct nfs4_delegation *dp = delegstateid(stid);
+
+	WARN_ON_ONCE(!list_empty(&stid->sc_cp_list));
+	WARN_ON_ONCE(!list_empty(&dp->dl_perfile));
+	WARN_ON_ONCE(!list_empty(&dp->dl_perclnt));
+	WARN_ON_ONCE(!list_empty(&dp->dl_recall_lru));
+	kmem_cache_free(deleg_slab, stid);
+	atomic_long_dec(&num_delegations);
+}
+
+/*
+ * When we recall a delegation, we should be careful not to hand it
+ * out again straight away.
+ * To ensure this we keep a pair of bloom filters ('new' and 'old')
+ * in which the filehandles of recalled delegations are "stored".
+ * If a filehandle appear in either filter, a delegation is blocked.
+ * When a delegation is recalled, the filehandle is stored in the "new"
+ * filter.
+ * Every 30 seconds we swap the filters and clear the "new" one,
+ * unless both are empty of course.  This results in delegations for a
+ * given filehandle being blocked for between 30 and 60 seconds.
+ *
+ * Each filter is 256 bits.  We hash the filehandle to 32bit and use the
+ * low 3 bytes as hash-table indices.
+ *
+ * 'blocked_delegations_lock', which is always taken in block_delegations(),
+ * is used to manage concurrent access.  Testing does not need the lock
+ * except when swapping the two filters.
+ */
+static DEFINE_SPINLOCK(blocked_delegations_lock);
+static struct bloom_pair {
+	int	entries, old_entries;
+	time64_t swap_time;
+	int	new; /* index into 'set' */
+	DECLARE_BITMAP(set[2], 256);
+} blocked_delegations;
+
+static int delegation_blocked(struct knfsd_fh *fh)
+{
+	u32 hash;
+	struct bloom_pair *bd = &blocked_delegations;
+
+	if (bd->entries == 0)
+		return 0;
+	if (ktime_get_seconds() - bd->swap_time > 30) {
+		spin_lock(&blocked_delegations_lock);
+		if (ktime_get_seconds() - bd->swap_time > 30) {
+			bd->entries -= bd->old_entries;
+			bd->old_entries = bd->entries;
+			bd->new = 1-bd->new;
+			memset(bd->set[bd->new], 0,
+			       sizeof(bd->set[0]));
+			bd->swap_time = ktime_get_seconds();
+		}
+		spin_unlock(&blocked_delegations_lock);
+	}
+	hash = jhash(&fh->fh_raw, fh->fh_size, 0);
+	if (test_bit(hash&255, bd->set[0]) &&
+	    test_bit((hash>>8)&255, bd->set[0]) &&
+	    test_bit((hash>>16)&255, bd->set[0]))
+		return 1;
+
+	if (test_bit(hash&255, bd->set[1]) &&
+	    test_bit((hash>>8)&255, bd->set[1]) &&
+	    test_bit((hash>>16)&255, bd->set[1]))
+		return 1;
+
+	return 0;
+}
+
+static void block_delegations(struct knfsd_fh *fh)
+{
+	u32 hash;
+	struct bloom_pair *bd = &blocked_delegations;
+
+	hash = jhash(&fh->fh_raw, fh->fh_size, 0);
+
+	spin_lock(&blocked_delegations_lock);
+	__set_bit(hash&255, bd->set[bd->new]);
+	__set_bit((hash>>8)&255, bd->set[bd->new]);
+	__set_bit((hash>>16)&255, bd->set[bd->new]);
+	if (bd->entries == 0)
+		bd->swap_time = ktime_get_seconds();
+	bd->entries += 1;
+	spin_unlock(&blocked_delegations_lock);
+}
+
+static struct nfs4_delegation *
+__alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
+		   struct nfs4_clnt_odstate *odstate, u32 dl_type,
+		   void (*sc_free)(struct nfs4_stid *))
+{
+	struct nfs4_delegation *dp;
+	struct nfs4_stid *stid;
+	long n;
+
+	if (delegation_blocked(&fp->fi_fhandle))
+		return NULL;
+
+	n = atomic_long_inc_return(&num_delegations);
+	if (n < 0 || n > max_delegations)
+		goto out_dec;
+
+	stid = nfs4_alloc_stid(clp, deleg_slab, sc_free);
+	if (stid == NULL)
+		goto out_dec;
+
+	/*
+	 * delegation seqid's are never incremented.  The 4.1 special
+	 * meaning of seqid 0 isn't meaningful, really, but let's avoid
+	 * 0 anyway just for consistency and use 1.
+	 */
+	dp = delegstateid(stid);
+	dp->dl_stid.sc_stateid.si_generation = 1;
+	INIT_LIST_HEAD(&dp->dl_perfile);
+	INIT_LIST_HEAD(&dp->dl_perclnt);
+	INIT_LIST_HEAD(&dp->dl_recall_lru);
+	dp->dl_clnt_odstate = odstate;
+	get_clnt_odstate(odstate);
+	dp->dl_type = dl_type;
+	dp->dl_retries = 1;
+	dp->dl_recalled = false;
+	get_nfs4_file(fp);
+	dp->dl_stid.sc_file = fp;
+	nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
+		      &nfsd4_cb_recall_ops, NFSPROC4_CLNT_CB_RECALL);
+	return dp;
+out_dec:
+	atomic_long_dec(&num_delegations);
+	return NULL;
+}
+
+static struct nfs4_delegation *
+alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
+		 struct nfs4_clnt_odstate *odstate, u32 dl_type)
+{
+	struct nfs4_delegation *dp;
+
+	dp = __alloc_init_deleg(clp, fp, odstate, dl_type, nfs4_free_deleg);
+	if (!dp)
+		return NULL;
+
+	nfsd4_init_cb(&dp->dl_cb_fattr.ncf_getattr, dp->dl_stid.sc_client,
+			&nfsd4_cb_getattr_ops, NFSPROC4_CLNT_CB_GETATTR);
+	dp->dl_cb_fattr.ncf_file_modified = false;
+	return dp;
+}
+
+static void nfs4_free_dir_deleg(struct nfs4_stid *stid)
+{
+	struct nfs4_delegation	*dp = delegstateid(stid);
+	struct nfsd4_cb_notify *ncn = &dp->dl_cb_notify;
+	int i;
+
+	for (i = 0; i < ncn->ncn_evt_cnt; ++i)
+		nfsd_notify_event_put(ncn->ncn_evt[i]);
+	kfree(ncn->ncn_nf);
+	for (i = 0; i < NOTIFY4_PAGE_ARRAY_SIZE; i++) {
+		if (!ncn->ncn_pages[i])
+			break;
+		put_page(ncn->ncn_pages[i]);
+	}
+	nfs4_free_deleg(stid);
+}
+
+static struct nfs4_delegation *
+alloc_init_dir_deleg(struct nfs4_client *clp, struct nfs4_file *fp)
+{
+	struct nfs4_delegation *dp;
+	struct nfsd4_cb_notify *ncn;
+	int npages;
+
+	dp = __alloc_init_deleg(clp, fp, NULL, NFS4_OPEN_DELEGATE_READ, nfs4_free_dir_deleg);
+	if (!dp)
+		return NULL;
+
+	ncn = &dp->dl_cb_notify;
+
+	npages = alloc_pages_bulk(GFP_KERNEL, NOTIFY4_PAGE_ARRAY_SIZE, ncn->ncn_pages);
+	if (npages != NOTIFY4_PAGE_ARRAY_SIZE) {
+		nfs4_put_stid(&dp->dl_stid);
+		return NULL;
+	}
+
+	ncn->ncn_nf = kzalloc_objs(*ncn->ncn_nf, NOTIFY4_EVENT_QUEUE_SIZE);
+	if (!ncn->ncn_nf) {
+		nfs4_put_stid(&dp->dl_stid);
+		return NULL;
+	}
+	spin_lock_init(&ncn->ncn_lock);
+	nfsd4_init_cb(&ncn->ncn_cb, dp->dl_stid.sc_client,
+			&nfsd4_cb_notify_ops, NFSPROC4_CLNT_CB_NOTIFY);
+	return dp;
+}
+
+void
+nfs4_put_stid(struct nfs4_stid *s)
+{
+	struct nfs4_file *fp = s->sc_file;
+	struct nfs4_client *clp = s->sc_client;
+	struct svc_export *exp;
+
+	might_lock(&clp->cl_lock);
+
+	if (!refcount_dec_and_lock(&s->sc_count, &clp->cl_lock)) {
+		wake_up_all(&close_wq);
+		return;
+	}
+	idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id);
+	if (s->sc_status & SC_STATUS_ADMIN_REVOKED)
+		atomic_dec(&s->sc_client->cl_admin_revoked);
+	/* Read under cl_lock to serialize with drop_stid_export(). */
+	exp = s->sc_export;
+	nfs4_free_cpntf_statelist(clp->net, s);
+	spin_unlock(&clp->cl_lock);
+	s->sc_free(s);
+	if (exp)
+		exp_put(exp);
+	if (fp)
+		put_nfs4_file(fp);
+}
+
+void
+nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid)
+{
+	stateid_t *src = &stid->sc_stateid;
+
+	spin_lock(&stid->sc_lock);
+	if (unlikely(++src->si_generation == 0))
+		src->si_generation = 1;
+	memcpy(dst, src, sizeof(*dst));
+	spin_unlock(&stid->sc_lock);
+}
+
+static void put_deleg_file(struct nfs4_file *fp)
+{
+	struct nfsd_file *rnf = NULL;
+	struct nfsd_file *nf = NULL;
+
+	spin_lock(&fp->fi_lock);
+	if (--fp->fi_delegees == 0) {
+		nf = rcu_dereference_protected(fp->fi_deleg_file,
+					       lockdep_is_held(&fp->fi_lock));
+		RCU_INIT_POINTER(fp->fi_deleg_file, NULL);
+		swap(rnf, fp->fi_rdeleg_file);
+	}
+	spin_unlock(&fp->fi_lock);
+
+	if (nf)
+		nfsd_file_put(nf);
+	if (rnf) {
+		nfsd_file_put(rnf);
+		nfs4_file_put_access(fp, NFS4_SHARE_ACCESS_READ);
+	}
+}
+
+static void nfsd4_finalize_deleg_timestamps(struct nfs4_delegation *dp, struct file *f)
+{
+	/* don't do anything if FMODE_NOCMTIME isn't set */
+	if ((READ_ONCE(f->f_mode) & FMODE_NOCMTIME) == 0)
+		return;
+
+	spin_lock(&f->f_lock);
+	f->f_mode &= ~FMODE_NOCMTIME;
+	spin_unlock(&f->f_lock);
+
+	/* was it never written? */
+	if (!dp->dl_written)
+		return;
+
+	/* did it get a setattr for the timestamps at some point? */
+	if (dp->dl_setattr)
+		return;
+
+	/* Stamp everything to "now" */
+	nfsd_update_cmtime_attr(f, ATTR_ATIME);
+}
+
+static void nfs4_unlock_deleg_lease(struct nfs4_delegation *dp)
+{
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+	struct nfsd_file *nf = rcu_dereference_protected(fp->fi_deleg_file, 1);
+
+	WARN_ON_ONCE(!fp->fi_delegees);
+
+	nfsd4_finalize_deleg_timestamps(dp, nf->nf_file);
+	kernel_setlease(nf->nf_file, F_UNLCK, NULL, (void **)&dp);
+	nfsd_fsnotify_recalc_mask(nf);
+	put_deleg_file(fp);
+}
+
+static void destroy_unhashed_deleg(struct nfs4_delegation *dp)
+{
+	put_clnt_odstate(dp->dl_clnt_odstate);
+	nfs4_unlock_deleg_lease(dp);
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+/**
+ * nfs4_delegation_exists - Discover if this delegation already exists
+ * @clp:     a pointer to the nfs4_client we're granting a delegation to
+ * @fp:      a pointer to the nfs4_file we're granting a delegation on
+ *
+ * Return:
+ *      On success: true iff an existing delegation is found
+ */
+
+static bool
+nfs4_delegation_exists(struct nfs4_client *clp, struct nfs4_file *fp)
+{
+	struct nfs4_delegation *searchdp = NULL;
+	struct nfs4_client *searchclp = NULL;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->deleg_lock);
+	lockdep_assert_held(&fp->fi_lock);
+
+	list_for_each_entry(searchdp, &fp->fi_delegations, dl_perfile) {
+		searchclp = searchdp->dl_stid.sc_client;
+		if (clp == searchclp) {
+			return true;
+		}
+	}
+	return false;
+}
+
+/**
+ * hash_delegation_locked - Add a delegation to the appropriate lists
+ * @dp:     a pointer to the nfs4_delegation we are adding.
+ * @fp:     a pointer to the nfs4_file we're granting a delegation on
+ *
+ * Return:
+ *      On success: NULL if the delegation was successfully hashed.
+ *
+ *      On error: -EAGAIN if one was previously granted to this
+ *                 nfs4_client for this nfs4_file. Delegation is not hashed.
+ *
+ */
+
+static int
+hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp)
+{
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->deleg_lock);
+	lockdep_assert_held(&fp->fi_lock);
+	lockdep_assert_held(&clp->cl_lock);
+
+	if (nfs4_delegation_exists(clp, fp))
+		return -EAGAIN;
+	refcount_inc(&dp->dl_stid.sc_count);
+	dp->dl_stid.sc_type = SC_TYPE_DELEG;
+	list_add(&dp->dl_perfile, &fp->fi_delegations);
+	list_add(&dp->dl_perclnt, &clp->cl_delegations);
+	return 0;
+}
+
+static bool delegation_hashed(struct nfs4_delegation *dp)
+{
+	return !(list_empty(&dp->dl_perfile));
+}
+
+static bool
+unhash_delegation_locked(struct nfs4_delegation *dp, unsigned short statusmask)
+{
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+	struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
+					  nfsd_net_id);
+
+	lockdep_assert_held(&nn->deleg_lock);
+
+	if (!delegation_hashed(dp))
+		return false;
+
+	if (statusmask == SC_STATUS_REVOKED &&
+	    dp->dl_stid.sc_client->cl_minorversion == 0)
+		statusmask = SC_STATUS_CLOSED;
+	dp->dl_stid.sc_status |= statusmask;
+	if (statusmask & SC_STATUS_ADMIN_REVOKED)
+		atomic_inc(&dp->dl_stid.sc_client->cl_admin_revoked);
+
+	/* Ensure that deleg break won't try to requeue it */
+	++dp->dl_time;
+	spin_lock(&fp->fi_lock);
+	list_del_init(&dp->dl_perclnt);
+	list_del_init(&dp->dl_recall_lru);
+	list_del_init(&dp->dl_perfile);
+	spin_unlock(&fp->fi_lock);
+	return true;
+}
+
+static void destroy_delegation(struct nfs4_delegation *dp)
+{
+	bool unhashed;
+	struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
+					  nfsd_net_id);
+
+	spin_lock(&nn->deleg_lock);
+	unhashed = unhash_delegation_locked(dp, SC_STATUS_CLOSED);
+	spin_unlock(&nn->deleg_lock);
+	if (unhashed)
+		destroy_unhashed_deleg(dp);
+}
+
+/**
+ * revoke_delegation - perform nfs4 delegation structure cleanup
+ * @dp: pointer to the delegation
+ *
+ * This function assumes that it's called either from the administrative
+ * interface (nfsd4_revoke_states()) that's revoking a specific delegation
+ * stateid or it's called from a laundromat thread (nfsd4_landromat()) that
+ * determined that this specific state has expired and needs to be revoked
+ * (both mark state with the appropriate stid sc_status mode). It is also
+ * assumed that a reference was taken on the @dp state. This function
+ * consumes that reference.
+ *
+ * If this function finds that the @dp state is SC_STATUS_FREED it means
+ * that a FREE_STATEID operation for this stateid has been processed and
+ * we can proceed to removing it from recalled list. However, if @dp state
+ * isn't marked SC_STATUS_FREED, it means we need place it on the cl_revoked
+ * list and wait for the FREE_STATEID to arrive from the client. At the same
+ * time, we need to mark it as SC_STATUS_FREEABLE to indicate to the
+ * nfsd4_free_stateid() function that this stateid has already been added
+ * to the cl_revoked list and that nfsd4_free_stateid() is now responsible
+ * for removing it from the list. Inspection of where the delegation state
+ * in the revocation process is protected by the clp->cl_lock.
+ */
+static void revoke_delegation(struct nfs4_delegation *dp)
+{
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+
+	WARN_ON(!list_empty(&dp->dl_recall_lru));
+	WARN_ON_ONCE(dp->dl_stid.sc_client->cl_minorversion > 0 &&
+		     !(dp->dl_stid.sc_status &
+		     (SC_STATUS_REVOKED | SC_STATUS_ADMIN_REVOKED)));
+
+	trace_nfsd_stid_revoke(&dp->dl_stid);
+
+	spin_lock(&clp->cl_lock);
+	if (dp->dl_stid.sc_status & SC_STATUS_FREED) {
+		list_del_init(&dp->dl_recall_lru);
+		goto out;
+	}
+	list_add(&dp->dl_recall_lru, &clp->cl_revoked);
+	dp->dl_stid.sc_status |= SC_STATUS_FREEABLE;
+out:
+	spin_unlock(&clp->cl_lock);
+	destroy_unhashed_deleg(dp);
+}
+
+/*
+ * SETCLIENTID state
+ */
+
+static unsigned int clientid_hashval(u32 id)
+{
+	return id & CLIENT_HASH_MASK;
+}
+
+static unsigned int clientstr_hashval(struct xdr_netobj name)
+{
+	return opaque_hashval(name.data, 8) & CLIENT_HASH_MASK;
+}
+
+/*
+ * A stateid that had a deny mode associated with it is being released
+ * or downgraded. Recalculate the deny mode on the file.
+ */
+static void
+recalculate_deny_mode(struct nfs4_file *fp)
+{
+	struct nfs4_ol_stateid *stp;
+	u32 old_deny;
+
+	spin_lock(&fp->fi_lock);
+	old_deny = fp->fi_share_deny;
+	fp->fi_share_deny = 0;
+	list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
+		fp->fi_share_deny |= bmap_to_share_mode(stp->st_deny_bmap);
+		if (fp->fi_share_deny == old_deny)
+			break;
+	}
+	spin_unlock(&fp->fi_lock);
+}
+
+static void
+reset_union_bmap_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	int i;
+	bool change = false;
+
+	for (i = 1; i < 4; i++) {
+		if ((i & deny) != i) {
+			change = true;
+			clear_deny(i, stp);
+		}
+	}
+
+	/* Recalculate per-file deny mode if there was a change */
+	if (change)
+		recalculate_deny_mode(stp->st_stid.sc_file);
+}
+
+/* release all access and file references for a given stateid */
+static void
+release_all_access(struct nfs4_ol_stateid *stp)
+{
+	int i;
+	struct nfs4_file *fp = stp->st_stid.sc_file;
+
+	if (fp && stp->st_deny_bmap != 0)
+		recalculate_deny_mode(fp);
+
+	for (i = 1; i < 4; i++) {
+		if (test_access(i, stp))
+			nfs4_file_put_access(stp->st_stid.sc_file, i);
+		clear_access(i, stp);
+	}
+}
+
+/**
+ * nfs4_replay_free_cache - release dynamically allocated replay buffer
+ * @rp: replay cache to reset
+ *
+ * If @rp->rp_buf points to a kmalloc'd buffer, free it and reset
+ * rp_buf to the inline rp_ibuf. Always zeroes rp_buflen.
+ */
+void nfs4_replay_free_cache(struct nfs4_replay *rp)
+{
+	if (rp->rp_buf != rp->rp_ibuf)
+		kfree(rp->rp_buf);
+	rp->rp_buf = rp->rp_ibuf;
+	rp->rp_buflen = 0;
+}
+
+static inline void nfs4_free_stateowner(struct nfs4_stateowner *sop)
+{
+	nfs4_replay_free_cache(&sop->so_replay);
+	kfree(sop->so_owner.data);
+	sop->so_ops->so_free(sop);
+}
+
+static void nfs4_put_stateowner(struct nfs4_stateowner *sop)
+{
+	struct nfs4_client *clp = sop->so_client;
+
+	might_lock(&clp->cl_lock);
+
+	if (!atomic_dec_and_lock(&sop->so_count, &clp->cl_lock))
+		return;
+	sop->so_ops->so_unhash(sop);
+	spin_unlock(&clp->cl_lock);
+	nfs4_free_stateowner(sop);
+}
+
+static bool
+nfs4_ol_stateid_unhashed(const struct nfs4_ol_stateid *stp)
+{
+	return list_empty(&stp->st_perfile);
+}
+
+static bool unhash_ol_stateid(struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_file *fp = stp->st_stid.sc_file;
+
+	lockdep_assert_held(&stp->st_stateowner->so_client->cl_lock);
+
+	if (list_empty(&stp->st_perfile))
+		return false;
+
+	spin_lock(&fp->fi_lock);
+	list_del_init(&stp->st_perfile);
+	spin_unlock(&fp->fi_lock);
+	list_del(&stp->st_perstateowner);
+	return true;
+}
+
+static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(stid);
+
+	put_clnt_odstate(stp->st_clnt_odstate);
+	release_all_access(stp);
+	if (stp->st_stateowner)
+		nfs4_put_stateowner(stp->st_stateowner);
+	if (!list_empty(&stid->sc_cp_list))
+		nfs4_free_cpntf_statelist(stid->sc_client->net, stid);
+	kmem_cache_free(stateid_slab, stid);
+}
+
+static void nfs4_free_lock_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(stid);
+	struct nfs4_lockowner *lo = lockowner(stp->st_stateowner);
+	struct nfsd_file *nf;
+
+	nf = find_any_file(stp->st_stid.sc_file);
+	if (nf) {
+		get_file(nf->nf_file);
+		filp_close(nf->nf_file, (fl_owner_t)lo);
+		nfsd_file_put(nf);
+	}
+	nfs4_free_ol_stateid(stid);
+}
+
+/*
+ * Put the persistent reference to an already unhashed generic stateid, while
+ * holding the cl_lock. If it's the last reference, then put it onto the
+ * reaplist for later destruction.
+ */
+static void put_ol_stateid_locked(struct nfs4_ol_stateid *stp,
+				       struct list_head *reaplist)
+{
+	struct nfs4_stid *s = &stp->st_stid;
+	struct nfs4_client *clp = s->sc_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	WARN_ON_ONCE(!list_empty(&stp->st_locks));
+
+	if (!refcount_dec_and_test(&s->sc_count)) {
+		wake_up_all(&close_wq);
+		return;
+	}
+
+	idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id);
+	if (s->sc_status & SC_STATUS_ADMIN_REVOKED)
+		atomic_dec(&s->sc_client->cl_admin_revoked);
+	list_add(&stp->st_locks, reaplist);
+}
+
+static bool unhash_lock_stateid(struct nfs4_ol_stateid *stp)
+{
+	lockdep_assert_held(&stp->st_stid.sc_client->cl_lock);
+
+	if (!unhash_ol_stateid(stp))
+		return false;
+	list_del_init(&stp->st_locks);
+	stp->st_stid.sc_status |= SC_STATUS_CLOSED;
+	return true;
+}
+
+static void release_lock_stateid(struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_client *clp = stp->st_stid.sc_client;
+	bool unhashed;
+
+	spin_lock(&clp->cl_lock);
+	unhashed = unhash_lock_stateid(stp);
+	spin_unlock(&clp->cl_lock);
+	if (unhashed)
+		nfs4_put_stid(&stp->st_stid);
+}
+
+static void unhash_lockowner_locked(struct nfs4_lockowner *lo)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_del_init(&lo->lo_owner.so_strhash);
+}
+
+/*
+ * Free a list of generic stateids that were collected earlier after being
+ * fully unhashed.
+ */
+static void
+free_ol_stateid_reaplist(struct list_head *reaplist)
+{
+	struct nfs4_ol_stateid *stp;
+	struct svc_export *exp;
+	struct nfs4_file *fp;
+
+	might_sleep();
+
+	while (!list_empty(reaplist)) {
+		stp = list_first_entry(reaplist, struct nfs4_ol_stateid,
+				       st_locks);
+		list_del(&stp->st_locks);
+		fp = stp->st_stid.sc_file;
+		exp = stp->st_stid.sc_export;
+		stp->st_stid.sc_free(&stp->st_stid);
+		if (exp)
+			exp_put(exp);
+		if (fp)
+			put_nfs4_file(fp);
+	}
+}
+
+static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp,
+				       struct list_head *reaplist)
+{
+	struct nfs4_ol_stateid *stp;
+
+	lockdep_assert_held(&open_stp->st_stid.sc_client->cl_lock);
+
+	while (!list_empty(&open_stp->st_locks)) {
+		stp = list_entry(open_stp->st_locks.next,
+				struct nfs4_ol_stateid, st_locks);
+		unhash_lock_stateid(stp);
+		put_ol_stateid_locked(stp, reaplist);
+	}
+}
+
+static bool unhash_open_stateid(struct nfs4_ol_stateid *stp,
+				struct list_head *reaplist)
+{
+	lockdep_assert_held(&stp->st_stid.sc_client->cl_lock);
+
+	if (!unhash_ol_stateid(stp))
+		return false;
+	release_open_stateid_locks(stp, reaplist);
+	return true;
+}
+
+static void release_open_stateid(struct nfs4_ol_stateid *stp)
+{
+	LIST_HEAD(reaplist);
+
+	spin_lock(&stp->st_stid.sc_client->cl_lock);
+	stp->st_stid.sc_status |= SC_STATUS_CLOSED;
+	if (unhash_open_stateid(stp, &reaplist))
+		put_ol_stateid_locked(stp, &reaplist);
+	spin_unlock(&stp->st_stid.sc_client->cl_lock);
+	free_ol_stateid_reaplist(&reaplist);
+}
+
+static bool nfs4_openowner_unhashed(struct nfs4_openowner *oo)
+{
+	lockdep_assert_held(&oo->oo_owner.so_client->cl_lock);
+
+	return list_empty(&oo->oo_owner.so_strhash) &&
+		list_empty(&oo->oo_perclient);
+}
+
+static void unhash_openowner_locked(struct nfs4_openowner *oo)
+{
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_del_init(&oo->oo_owner.so_strhash);
+	list_del_init(&oo->oo_perclient);
+}
+
+static void release_last_closed_stateid(struct nfs4_openowner *oo)
+{
+	struct nfsd_net *nn = net_generic(oo->oo_owner.so_client->net,
+					  nfsd_net_id);
+	struct nfs4_ol_stateid *s;
+
+	spin_lock(&nn->client_lock);
+	s = oo->oo_last_closed_stid;
+	if (s) {
+		list_del_init(&oo->oo_close_lru);
+		oo->oo_last_closed_stid = NULL;
+	}
+	spin_unlock(&nn->client_lock);
+	if (s)
+		nfs4_put_stid(&s->st_stid);
+}
+
+static void release_openowner(struct nfs4_openowner *oo)
+{
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&clp->cl_lock);
+	unhash_openowner_locked(oo);
+	while (!list_empty(&oo->oo_owner.so_stateids)) {
+		stp = list_first_entry(&oo->oo_owner.so_stateids,
+				struct nfs4_ol_stateid, st_perstateowner);
+		if (unhash_open_stateid(stp, &reaplist))
+			put_ol_stateid_locked(stp, &reaplist);
+	}
+	spin_unlock(&clp->cl_lock);
+	free_ol_stateid_reaplist(&reaplist);
+	release_last_closed_stateid(oo);
+	nfs4_put_stateowner(&oo->oo_owner);
+}
+
+static struct nfs4_stid *find_one_sb_stid(struct nfs4_client *clp,
+					  struct super_block *sb,
+					  unsigned int sc_types)
+{
+	unsigned long id = 0;
+	struct nfs4_stid *stid;
+
+	spin_lock(&clp->cl_lock);
+	while ((stid = idr_get_next_ul(&clp->cl_stateids, &id)) != NULL) {
+		if ((stid->sc_type & sc_types) &&
+		    stid->sc_status == 0 &&
+		    stid->sc_file->fi_inode->i_sb == sb) {
+			refcount_inc(&stid->sc_count);
+			break;
+		}
+		id++;
+	}
+	spin_unlock(&clp->cl_lock);
+	return stid;
+}
+
+/*
+ * Release the export reference an admin-revoked stateid holds,
+ * so the svc_export (and its vfsmount) is not pinned until the
+ * client issues FREE_STATEID.  sc_export is no longer consulted
+ * once SC_STATUS_ADMIN_REVOKED is set.
+ */
+static void drop_stid_export(struct nfs4_client *clp,
+			     struct nfs4_stid *stid)
+{
+	struct svc_export *exp;
+
+	spin_lock(&clp->cl_lock);
+	exp = stid->sc_export;
+	stid->sc_export = NULL;
+	spin_unlock(&clp->cl_lock);
+	if (exp)
+		exp_put(exp);
+}
+
+static void revoke_ol_stid(struct nfs4_client *clp,
+			   struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_stid *stid = &stp->st_stid;
+
+	lockdep_assert_held(&stp->st_mutex);
+	spin_lock(&clp->cl_lock);
+	if (stid->sc_status == 0) {
+		stid->sc_status |= SC_STATUS_ADMIN_REVOKED;
+		atomic_inc(&clp->cl_admin_revoked);
+		spin_unlock(&clp->cl_lock);
+		if (stid->sc_type == SC_TYPE_LOCK) {
+			struct nfs4_lockowner *lo =
+				lockowner(stp->st_stateowner);
+			struct nfsd_file *nf;
+
+			nf = find_any_file(stp->st_stid.sc_file);
+			if (nf) {
+				get_file(nf->nf_file);
+				filp_close(nf->nf_file, (fl_owner_t)lo);
+				nfsd_file_put(nf);
+			}
+		}
+		release_all_access(stp);
+		drop_stid_export(clp, stid);
+	} else
+		spin_unlock(&clp->cl_lock);
+}
+
+static void revoke_one_stid(struct nfsd_net *nn, struct nfs4_client *clp,
+			    struct nfs4_stid *stid)
+{
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_delegation *dp;
+
+	switch (stid->sc_type) {
+	case SC_TYPE_OPEN:
+		stp = openlockstateid(stid);
+		mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX);
+		revoke_ol_stid(clp, stp);
+		mutex_unlock(&stp->st_mutex);
+		break;
+	case SC_TYPE_LOCK:
+		stp = openlockstateid(stid);
+		mutex_lock_nested(&stp->st_mutex, LOCK_STATEID_MUTEX);
+		revoke_ol_stid(clp, stp);
+		mutex_unlock(&stp->st_mutex);
+		break;
+	case SC_TYPE_DELEG:
+		/*
+		 * Extra reference guards against concurrent FREE_STATEID.
+		 */
+		refcount_inc(&stid->sc_count);
+		dp = delegstateid(stid);
+		spin_lock(&nn->deleg_lock);
+		if (!unhash_delegation_locked(dp, SC_STATUS_ADMIN_REVOKED))
+			dp = NULL;
+		spin_unlock(&nn->deleg_lock);
+		if (dp) {
+			revoke_delegation(dp);
+			drop_stid_export(clp, stid);
+		} else
+			nfs4_put_stid(stid);
+		break;
+	case SC_TYPE_LAYOUT:
+		spin_lock(&clp->cl_lock);
+		if (stid->sc_status == 0) {
+			stid->sc_status |= SC_STATUS_ADMIN_REVOKED;
+			atomic_inc(&clp->cl_admin_revoked);
+		}
+		spin_unlock(&clp->cl_lock);
+		nfsd4_close_layout(layoutstateid(stid));
+		drop_stid_export(clp, stid);
+		break;
+	}
+}
+
+/**
+ * nfsd4_revoke_states - revoke all nfsv4 states associated with given filesystem
+ * @nn:   used to identify instance of nfsd (there is one per net namespace)
+ * @sb:   super_block used to identify target filesystem
+ *
+ * All nfs4 states (open, lock, delegation, layout) held by the server instance
+ * and associated with a file on the given filesystem will be revoked resulting
+ * in any files being closed and so all references from nfsd to the filesystem
+ * being released.  Thus nfsd will no longer prevent the filesystem from being
+ * unmounted.
+ *
+ * The clients which own the states will subsequently be notified that the
+ * states have been "admin-revoked".
+ *
+ * Context: Caller must hold nfsd_mutex with NFSD_NET_UP set.  Outside
+ *          that window nn->conf_id_hashtbl is unallocated or freed,
+ *          so the walk would dereference a NULL or dangling pointer.
+ */
+void nfsd4_revoke_states(struct nfsd_net *nn, struct super_block *sb)
+{
+	unsigned int idhashval;
+	unsigned int sc_types;
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	sc_types = SC_TYPE_OPEN | SC_TYPE_LOCK | SC_TYPE_DELEG | SC_TYPE_LAYOUT;
+
+	spin_lock(&nn->client_lock);
+	for (idhashval = 0; idhashval < CLIENT_HASH_SIZE; idhashval++) {
+		struct list_head *head = &nn->conf_id_hashtbl[idhashval];
+		struct nfs4_client *clp;
+	retry:
+		list_for_each_entry(clp, head, cl_idhash) {
+			struct nfs4_stid *stid;
+
+			/*
+			 * force_expire_client() ignores cl_rpc_users once
+			 * its wait_event() has passed, so pinning cannot
+			 * keep an already-expiring client alive; the
+			 * expiry path revokes its states instead.
+			 */
+			if (is_client_expired(clp))
+				continue;
+			stid = find_one_sb_stid(clp, sb, sc_types);
+			if (stid) {
+				atomic_inc(&clp->cl_rpc_users);
+				spin_unlock(&nn->client_lock);
+				revoke_one_stid(nn, clp, stid);
+				nfs4_put_stid(stid);
+				spin_lock(&nn->client_lock);
+				if (clp->cl_minorversion == 0)
+					/* Allow cleanup after a lease period.
+					 * store_release ensures cleanup will
+					 * see any newly revoked states if it
+					 * sees the time updated.
+					 */
+					nn->nfs40_last_revoke =
+						ktime_get_boottime_seconds();
+				put_client_no_renew_locked(clp);
+				goto retry;
+			}
+		}
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static struct nfs4_stid *find_one_export_stid(struct nfs4_client *clp,
+					     const struct path *path,
+					     unsigned int sc_types)
+{
+	unsigned long id = 0;
+	struct nfs4_stid *stid;
+
+	spin_lock(&clp->cl_lock);
+	while ((stid = idr_get_next_ul(&clp->cl_stateids, &id)) != NULL) {
+		if ((stid->sc_type & sc_types) &&
+		    stid->sc_status == 0 &&
+		    stid->sc_export &&
+		    path_equal(&stid->sc_export->ex_path, path)) {
+			refcount_inc(&stid->sc_count);
+			break;
+		}
+		id++;
+	}
+	spin_unlock(&clp->cl_lock);
+	return stid;
+}
+
+/**
+ * nfsd4_revoke_export_states - revoke nfsv4 states acquired through an export
+ * @nn:   used to identify instance of nfsd (there is one per net namespace)
+ * @path: export path whose states should be revoked
+ *
+ * All nfs4 states (open, lock, delegation, layout) acquired through any
+ * export matching @path are revoked, regardless of which client holds
+ * them.  Matching is by path identity (dentry + vfsmount), so multiple
+ * svc_export objects for the same path -- one per auth_domain -- are
+ * handled correctly.
+ *
+ * Userspace (exportfs -u) sends this after removing the last client
+ * for a path, enabling the underlying filesystem to be unmounted.
+ *
+ * Context: Caller must hold nfsd_mutex with NFSD_NET_UP set.  Outside
+ *          that window nn->conf_id_hashtbl is unallocated or freed,
+ *          so the walk would dereference a NULL or dangling pointer.
+ */
+void nfsd4_revoke_export_states(struct nfsd_net *nn, const struct path *path)
+{
+	unsigned int idhashval;
+	unsigned int sc_types;
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	sc_types = SC_TYPE_OPEN | SC_TYPE_LOCK | SC_TYPE_DELEG | SC_TYPE_LAYOUT;
+
+	spin_lock(&nn->client_lock);
+	for (idhashval = 0; idhashval < CLIENT_HASH_SIZE; idhashval++) {
+		struct list_head *head = &nn->conf_id_hashtbl[idhashval];
+		struct nfs4_client *clp;
+	retry:
+		list_for_each_entry(clp, head, cl_idhash) {
+			struct nfs4_stid *stid;
+
+			/* Skip or pin clp as in nfsd4_revoke_states(). */
+			if (is_client_expired(clp))
+				continue;
+			stid = find_one_export_stid(clp, path, sc_types);
+			if (stid) {
+				atomic_inc(&clp->cl_rpc_users);
+				spin_unlock(&nn->client_lock);
+				revoke_one_stid(nn, clp, stid);
+				nfs4_put_stid(stid);
+				spin_lock(&nn->client_lock);
+				if (clp->cl_minorversion == 0)
+					nn->nfs40_last_revoke =
+						ktime_get_boottime_seconds();
+				put_client_no_renew_locked(clp);
+				goto retry;
+			}
+		}
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static inline int
+hash_sessionid(struct nfs4_sessionid *sessionid)
+{
+	struct nfsd4_sessionid *sid = (struct nfsd4_sessionid *)sessionid;
+
+	return sid->sequence % SESSION_HASH_SIZE;
+}
+
+#ifdef CONFIG_SUNRPC_DEBUG
+static inline void
+dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
+{
+	u32 *ptr = (u32 *)(&sessionid->data[0]);
+	dprintk("%s: %u:%u:%u:%u\n", fn, ptr[0], ptr[1], ptr[2], ptr[3]);
+}
+#else
+static inline void
+dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
+{
+}
+#endif
+
+/*
+ * Bump the seqid on cstate->replay_owner, and clear replay_owner if it
+ * won't be used for replay.
+ */
+void nfsd4_bump_seqid(struct nfsd4_compound_state *cstate, __be32 nfserr)
+{
+	struct nfs4_stateowner *so = cstate->replay_owner;
+
+	if (nfserr == nfserr_replay_me)
+		return;
+
+	if (!seqid_mutating_err(ntohl(nfserr))) {
+		nfsd4_cstate_clear_replay(cstate);
+		return;
+	}
+	if (!so)
+		return;
+	if (so->so_is_open_owner)
+		release_last_closed_stateid(openowner(so));
+	so->so_seqid++;
+	return;
+}
+
+static void
+gen_sessionid(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd4_sessionid *sid;
+
+	sid = (struct nfsd4_sessionid *)ses->se_sessionid.data;
+	sid->clientid = clp->cl_clientid;
+	sid->sequence = current_sessionid++;
+	sid->reserved = 0;
+}
+
+/*
+ * The protocol defines ca_maxresponssize_cached to include the size of
+ * the rpc header, but all we need to cache is the data starting after
+ * the end of the initial SEQUENCE operation--the rest we regenerate
+ * each time.  Therefore we can advertise a ca_maxresponssize_cached
+ * value that is the number of bytes in our cache plus a few additional
+ * bytes.  In order to stay on the safe side, and not promise more than
+ * we can cache, those additional bytes must be the minimum possible: 24
+ * bytes of rpc header (xid through accept state, with AUTH_NULL
+ * verifier), 12 for the compound header (with zero-length tag), and 44
+ * for the SEQUENCE op response:
+ */
+#define NFSD_MIN_HDR_SEQ_SZ  (24 + 12 + 44)
+
+static struct shrinker *nfsd_slot_shrinker;
+static DEFINE_SPINLOCK(nfsd_session_list_lock);
+static LIST_HEAD(nfsd_session_list);
+/* The sum of "target_slots" on every session, slot 0 included. */
+static atomic_t nfsd_total_target_slots = ATOMIC_INIT(0);
+/* Session count, subtracted from the sum to exclude slot 0. */
+static atomic_t nfsd_total_sessions = ATOMIC_INIT(0);
+
+static void
+free_session_slots(struct nfsd4_session *ses, int from)
+{
+	int i;
+
+	if (from >= ses->se_fchannel.maxreqs)
+		return;
+
+	for (i = from; i < ses->se_fchannel.maxreqs; i++) {
+		struct nfsd4_slot *slot = xa_load(&ses->se_slots, i);
+
+		/*
+		 * Save the seqid in case we reactivate this slot.
+		 * This will never require a memory allocation so GFP
+		 * flag is irrelevant
+		 */
+		xa_store(&ses->se_slots, i, xa_mk_value(slot->sl_seqid), 0);
+		free_svc_cred(&slot->sl_cred);
+		kfree(slot);
+	}
+	ses->se_fchannel.maxreqs = from;
+	if (ses->se_target_maxslots > from) {
+		int delta = ses->se_target_maxslots - from;
+
+		atomic_sub(delta, &nfsd_total_target_slots);
+		/* Retain one slot so the session can make forward progress. */
+		ses->se_target_maxslots = from ?: 1;
+	}
+}
+
+/*
+ * This interface can be used by a shrinker to reduce the target max-slots
+ * for a session so that some slots can eventually be freed.
+ * It uses spin_trylock() as it may be called in a context where another
+ * spinlock is held that has a dependency on client_lock.  As shrinkers are
+ * best-effort, skipping a session with the client_lock already held has no
+ * great cost.
+ */
+static int
+reduce_session_slots(struct nfsd4_session *ses, int dec)
+{
+	struct nfsd_net *nn = net_generic(ses->se_client->net,
+					  nfsd_net_id);
+	int ret = 0;
+
+	if (ses->se_target_maxslots <= 1)
+		return ret;
+	if (!spin_trylock(&nn->client_lock))
+		return ret;
+	ret = min(dec, ses->se_target_maxslots-1);
+	ses->se_target_maxslots -= ret;
+	atomic_sub(ret, &nfsd_total_target_slots);
+	ses->se_slot_gen += 1;
+	if (ses->se_slot_gen == 0) {
+		int i;
+		ses->se_slot_gen = 1;
+		for (i = 0; i < ses->se_fchannel.maxreqs; i++) {
+			struct nfsd4_slot *slot = xa_load(&ses->se_slots, i);
+			slot->sl_generation = 0;
+		}
+	}
+	spin_unlock(&nn->client_lock);
+	return ret;
+}
+
+static struct nfsd4_slot *nfsd4_alloc_slot(struct nfsd4_channel_attrs *fattrs,
+					   int index, gfp_t gfp)
+{
+	struct nfsd4_slot *slot;
+	size_t size;
+
+	/*
+	 * The RPC and NFS session headers are never saved in
+	 * the slot reply cache buffer.
+	 */
+	size = fattrs->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ ?
+		0 : fattrs->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
+
+	slot = kzalloc_flex(*slot, sl_data, size, gfp);
+	if (!slot)
+		return NULL;
+	slot->sl_index = index;
+	return slot;
+}
+
+static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs,
+					   struct nfsd4_channel_attrs *battrs)
+{
+	int numslots = fattrs->maxreqs;
+	struct nfsd4_session *new;
+	struct nfsd4_slot *slot;
+	int i;
+
+	new = kzalloc_obj(*new);
+	if (!new)
+		return NULL;
+	xa_init(&new->se_slots);
+
+	slot = nfsd4_alloc_slot(fattrs, 0, GFP_KERNEL);
+	if (!slot || xa_is_err(xa_store(&new->se_slots, 0, slot, GFP_KERNEL)))
+		goto out_free;
+
+	for (i = 1; i < numslots; i++) {
+		const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
+		slot = nfsd4_alloc_slot(fattrs, i, gfp);
+		if (!slot)
+			break;
+		if (xa_is_err(xa_store(&new->se_slots, i, slot, gfp))) {
+			kfree(slot);
+			break;
+		}
+	}
+	fattrs->maxreqs = i;
+	memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs));
+	new->se_target_maxslots = i;
+	atomic_add(i, &nfsd_total_target_slots);
+	new->se_cb_slot_avail = ~0U;
+	new->se_cb_highest_slot = min(battrs->maxreqs - 1,
+				      NFSD_BC_SLOT_TABLE_SIZE - 1);
+	spin_lock_init(&new->se_lock);
+	return new;
+out_free:
+	kfree(slot);
+	xa_destroy(&new->se_slots);
+	kfree(new);
+	return NULL;
+}
+
+static void free_conn(struct nfsd4_conn *c)
+{
+	svc_xprt_put(c->cn_xprt);
+	kfree(c);
+}
+
+static void nfsd4_conn_lost(struct svc_xpt_user *u)
+{
+	struct nfsd4_conn *c = container_of(u, struct nfsd4_conn, cn_xpt_user);
+	struct nfs4_client *clp = c->cn_session->se_client;
+
+	trace_nfsd_cb_lost(clp);
+
+	spin_lock(&clp->cl_lock);
+	if (!list_empty(&c->cn_persession)) {
+		list_del(&c->cn_persession);
+		free_conn(c);
+	}
+	nfsd4_probe_callback(clp);
+	spin_unlock(&clp->cl_lock);
+}
+
+static struct nfsd4_conn *alloc_conn(struct svc_rqst *rqstp, u32 flags)
+{
+	struct nfsd4_conn *conn;
+
+	conn = kmalloc_obj(struct nfsd4_conn);
+	if (!conn)
+		return NULL;
+	svc_xprt_get(rqstp->rq_xprt);
+	conn->cn_xprt = rqstp->rq_xprt;
+	conn->cn_flags = flags;
+	INIT_LIST_HEAD(&conn->cn_xpt_user.list);
+	return conn;
+}
+
+static void __nfsd4_hash_conn(struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	conn->cn_session = ses;
+	list_add(&conn->cn_persession, &ses->se_conns);
+}
+
+static void nfsd4_hash_conn(struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+
+	spin_lock(&clp->cl_lock);
+	__nfsd4_hash_conn(conn, ses);
+	spin_unlock(&clp->cl_lock);
+}
+
+static int nfsd4_register_conn(struct nfsd4_conn *conn)
+{
+	conn->cn_xpt_user.callback = nfsd4_conn_lost;
+	return register_xpt_user(conn->cn_xprt, &conn->cn_xpt_user);
+}
+
+static void nfsd4_init_conn(struct svc_rqst *rqstp, struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	int ret;
+
+	nfsd4_hash_conn(conn, ses);
+	ret = nfsd4_register_conn(conn);
+	if (ret)
+		/* oops; xprt is already down: */
+		nfsd4_conn_lost(&conn->cn_xpt_user);
+	/* We may have gained or lost a callback channel: */
+	nfsd4_probe_callback_sync(ses->se_client);
+}
+
+static struct nfsd4_conn *alloc_conn_from_crses(struct svc_rqst *rqstp, struct nfsd4_create_session *cses)
+{
+	u32 dir = NFS4_CDFC4_FORE;
+
+	if (cses->flags & SESSION4_BACK_CHAN)
+		dir |= NFS4_CDFC4_BACK;
+	return alloc_conn(rqstp, dir);
+}
+
+/* must be called under client_lock */
+static void nfsd4_del_conns(struct nfsd4_session *s)
+{
+	struct nfs4_client *clp = s->se_client;
+	struct nfsd4_conn *c;
+
+	spin_lock(&clp->cl_lock);
+	while (!list_empty(&s->se_conns)) {
+		c = list_first_entry(&s->se_conns, struct nfsd4_conn, cn_persession);
+		list_del_init(&c->cn_persession);
+		spin_unlock(&clp->cl_lock);
+
+		unregister_xpt_user(c->cn_xprt, &c->cn_xpt_user);
+		free_conn(c);
+
+		spin_lock(&clp->cl_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static void __free_session(struct nfsd4_session *ses)
+{
+	free_session_slots(ses, 0);
+	xa_destroy(&ses->se_slots);
+	kfree_rcu(ses, rcu_head);
+}
+
+static void free_session(struct nfsd4_session *ses)
+{
+	nfsd4_del_conns(ses);
+	__free_session(ses);
+}
+
+/**
+ * nfsd_slot_shrinker_count - report reclaimable DRC slots
+ * @s: shrinker descriptor (unused)
+ * @sc: shrink control (unused)
+ *
+ * Return: a positive count of reclaimable slots, or SHRINK_EMPTY when
+ * there is nothing to reclaim.
+ */
+static unsigned long
+nfsd_slot_shrinker_count(struct shrinker *s, struct shrink_control *sc)
+{
+	int count;
+
+	/*
+	 * To prevent session deadlock, one slot of each session (slot 0)
+	 * is not reclaimable while the session is active. Thus the number
+	 * of sessions is subtracted from the total number of target slots.
+	 */
+	count = atomic_read(&nfsd_total_target_slots) -
+		atomic_read(&nfsd_total_sessions);
+
+	return count > 0 ? count : SHRINK_EMPTY;
+}
+
+/**
+ * nfsd_slot_shrinker_scan - reclaim DRC slots under memory pressure
+ * @s: shrinker descriptor (unused)
+ * @sc: shrink control; @sc->nr_to_scan bounds the sessions visited,
+ *      @sc->nr_scanned reports how many were visited
+ *
+ * Return: the number of session slots NFSD will release.
+ */
+static unsigned long
+nfsd_slot_shrinker_scan(struct shrinker *s, struct shrink_control *sc)
+{
+	struct nfsd4_session *ses;
+	unsigned long scanned = 0;
+	unsigned long freed = 0;
+
+	/*
+	 * Each visited session releases at most one slot. After
+	 * nr_to_scan sessions have been visited, the list head is
+	 * rotated past the last visited session so the next scan
+	 * resumes from there.
+	 */
+	spin_lock(&nfsd_session_list_lock);
+	list_for_each_entry(ses, &nfsd_session_list, se_all_sessions) {
+		freed += reduce_session_slots(ses, 1);
+		scanned += 1;
+		if (scanned >= sc->nr_to_scan) {
+			/* Move starting point for next scan */
+			list_move(&nfsd_session_list, &ses->se_all_sessions);
+			break;
+		}
+	}
+	spin_unlock(&nfsd_session_list_lock);
+	sc->nr_scanned = scanned;
+	return freed;
+}
+
+static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses)
+{
+	int idx;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	new->se_client = clp;
+	gen_sessionid(new);
+
+	INIT_LIST_HEAD(&new->se_conns);
+
+	atomic_set(&new->se_ref, 0);
+	new->se_dead = false;
+	new->se_cb_prog = cses->callback_prog;
+	new->se_cb_sec = cses->cb_sec;
+
+	for (idx = 0; idx < NFSD_BC_SLOT_TABLE_SIZE; ++idx)
+		new->se_cb_seq_nr[idx] = 1;
+
+	idx = hash_sessionid(&new->se_sessionid);
+	list_add(&new->se_hash, &nn->sessionid_hashtbl[idx]);
+	spin_lock(&clp->cl_lock);
+	list_add(&new->se_perclnt, &clp->cl_sessions);
+	spin_unlock(&clp->cl_lock);
+
+	spin_lock(&nfsd_session_list_lock);
+	list_add_tail(&new->se_all_sessions, &nfsd_session_list);
+	atomic_inc(&nfsd_total_sessions);
+	spin_unlock(&nfsd_session_list_lock);
+
+	{
+		struct sockaddr *sa = svc_addr(rqstp);
+		/*
+		 * This is a little silly; with sessions there's no real
+		 * use for the callback address.  Use the peer address
+		 * as a reasonable default for now, but consider fixing
+		 * the rpc client not to require an address in the
+		 * future:
+		 */
+		rpc_copy_addr((struct sockaddr *)&clp->cl_cb_conn.cb_addr, sa);
+		clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
+	}
+}
+
+/* caller must hold client_lock */
+static struct nfsd4_session *
+__find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid, struct net *net)
+{
+	struct nfsd4_session *elem;
+	int idx;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	dump_sessionid(__func__, sessionid);
+	idx = hash_sessionid(sessionid);
+	/* Search in the appropriate list */
+	list_for_each_entry(elem, &nn->sessionid_hashtbl[idx], se_hash) {
+		if (!memcmp(elem->se_sessionid.data, sessionid->data,
+			    NFS4_MAX_SESSIONID_LEN)) {
+			return elem;
+		}
+	}
+
+	dprintk("%s: session not found\n", __func__);
+	return NULL;
+}
+
+static struct nfsd4_session *
+find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid, struct net *net,
+		__be32 *ret)
+{
+	struct nfsd4_session *session;
+	__be32 status = nfserr_badsession;
+
+	session = __find_in_sessionid_hashtbl(sessionid, net);
+	if (!session)
+		goto out;
+	status = nfsd4_get_session_locked(session);
+	if (status)
+		session = NULL;
+out:
+	*ret = status;
+	return session;
+}
+
+/* caller must hold client_lock */
+static void
+unhash_session(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	list_del(&ses->se_hash);
+	spin_lock(&ses->se_client->cl_lock);
+	list_del(&ses->se_perclnt);
+	spin_unlock(&ses->se_client->cl_lock);
+	spin_lock(&nfsd_session_list_lock);
+	list_del(&ses->se_all_sessions);
+	atomic_dec(&nfsd_total_sessions);
+	spin_unlock(&nfsd_session_list_lock);
+}
+
+/* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */
+static int
+STALE_CLIENTID(clientid_t *clid, struct nfsd_net *nn)
+{
+	/*
+	 * We're assuming the clid was not given out from a boot
+	 * precisely 2^32 (about 136 years) before this one.  That seems
+	 * a safe assumption:
+	 */
+	if (clid->cl_boot == (u32)nn->boot_time)
+		return 0;
+	trace_nfsd_clid_stale(clid);
+	return 1;
+}
+
+static struct nfs4_client *alloc_client(struct xdr_netobj name,
+				struct nfsd_net *nn)
+{
+	struct nfs4_client *clp;
+	int i;
+
+	if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients &&
+	    atomic_read(&nn->nfsd_courtesy_clients) > 0)
+		mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+
+	clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
+	if (clp == NULL)
+		return NULL;
+	xdr_netobj_dup(&clp->cl_name, &name, GFP_KERNEL);
+	if (clp->cl_name.data == NULL)
+		goto err_no_name;
+	clp->cl_ownerstr_hashtbl = kmalloc_objs(struct list_head,
+						OWNER_HASH_SIZE);
+	if (!clp->cl_ownerstr_hashtbl)
+		goto err_no_hashtbl;
+	clp->cl_callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
+	if (!clp->cl_callback_wq)
+		goto err_no_callback_wq;
+
+	for (i = 0; i < OWNER_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&clp->cl_ownerstr_hashtbl[i]);
+	INIT_LIST_HEAD(&clp->cl_sessions);
+	idr_init(&clp->cl_stateids);
+	atomic_set(&clp->cl_rpc_users, 0);
+	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	clp->cl_state = NFSD4_ACTIVE;
+	atomic_inc(&nn->nfs4_client_count);
+	atomic_set(&clp->cl_delegs_in_recall, 0);
+	INIT_LIST_HEAD(&clp->cl_idhash);
+	INIT_LIST_HEAD(&clp->cl_openowners);
+	INIT_LIST_HEAD(&clp->cl_delegations);
+	INIT_LIST_HEAD(&clp->cl_lru);
+	INIT_LIST_HEAD(&clp->cl_revoked);
+#ifdef CONFIG_NFSD_PNFS
+	INIT_LIST_HEAD(&clp->cl_lo_states);
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	xa_init(&clp->cl_dev_fences);
+	mutex_init(&clp->cl_fence_mutex);
+#endif
+	INIT_LIST_HEAD(&clp->async_copies);
+	spin_lock_init(&clp->async_lock);
+	spin_lock_init(&clp->cl_lock);
+	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
+	return clp;
+err_no_callback_wq:
+	kfree(clp->cl_ownerstr_hashtbl);
+err_no_hashtbl:
+	kfree(clp->cl_name.data);
+err_no_name:
+	kmem_cache_free(client_slab, clp);
+	return NULL;
+}
+
+static void __free_client(struct kref *k)
+{
+	struct nfsdfs_client *c = container_of(k, struct nfsdfs_client, cl_ref);
+	struct nfs4_client *clp = container_of(c, struct nfs4_client, cl_nfsdfs);
+
+	free_svc_cred(&clp->cl_cred);
+	destroy_workqueue(clp->cl_callback_wq);
+	kfree(clp->cl_ownerstr_hashtbl);
+	kfree(clp->cl_name.data);
+	kfree(clp->cl_nii_domain.data);
+	kfree(clp->cl_nii_name.data);
+	idr_destroy(&clp->cl_stateids);
+	kfree(clp->cl_ra);
+	kmem_cache_free(client_slab, clp);
+}
+
+/**
+ * nfsd4_put_client - release a reference on an nfs4_client
+ * @clp: the client to be released
+ *
+ * When the last reference is released, the client is freed.
+ */
+void nfsd4_put_client(struct nfs4_client *clp)
+{
+	kref_put(&clp->cl_nfsdfs.cl_ref, __free_client);
+}
+
+static void
+free_client(struct nfs4_client *clp)
+{
+	while (!list_empty(&clp->cl_sessions)) {
+		struct nfsd4_session *ses;
+		ses = list_entry(clp->cl_sessions.next, struct nfsd4_session,
+				se_perclnt);
+		list_del(&ses->se_perclnt);
+		WARN_ON_ONCE(atomic_read(&ses->se_ref));
+		free_session(ses);
+	}
+	rpc_destroy_wait_queue(&clp->cl_cb_waitq);
+	if (clp->cl_nfsd_dentry) {
+		nfsd_client_rmdir(clp->cl_nfsd_dentry);
+		clp->cl_nfsd_dentry = NULL;
+		wake_up_all(&expiry_wq);
+	}
+	nfsd4_put_client(clp);
+}
+
+/* must be called under the client_lock */
+static void
+unhash_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfsd4_session *ses;
+
+	lockdep_assert_held(&nn->client_lock);
+
+	/* Mark the client as expired! */
+	clp->cl_time = 0;
+	/* Make it invisible */
+	if (!list_empty(&clp->cl_idhash)) {
+		list_del_init(&clp->cl_idhash);
+		if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
+			rb_erase(&clp->cl_namenode, &nn->conf_name_tree);
+		else
+			rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
+	}
+	list_del_init(&clp->cl_lru);
+	spin_lock(&clp->cl_lock);
+	spin_lock(&nfsd_session_list_lock);
+	list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) {
+		list_del_init(&ses->se_hash);
+		/*
+		 * unhash_client_locked() can run more than once for a
+		 * client; the session stays on cl_sessions across calls.
+		 * The first pass empties se_all_sessions via
+		 * list_del_init(), so skip the decrement on later passes
+		 * to keep nfsd_total_sessions from being double-counted.
+		 */
+		if (!list_empty(&ses->se_all_sessions)) {
+			list_del_init(&ses->se_all_sessions);
+			atomic_dec(&nfsd_total_sessions);
+		}
+	}
+	spin_unlock(&nfsd_session_list_lock);
+	spin_unlock(&clp->cl_lock);
+}
+
+static void
+unhash_client(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	unhash_client_locked(clp);
+	spin_unlock(&nn->client_lock);
+}
+
+static __be32 mark_client_expired_locked(struct nfs4_client *clp)
+{
+	int users = atomic_read(&clp->cl_rpc_users);
+
+	trace_nfsd_mark_client_expired(clp, users);
+
+	if (users)
+		return nfserr_jukebox;
+	unhash_client_locked(clp);
+	return nfs_ok;
+}
+
+static void
+__destroy_client(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	int i;
+	struct nfs4_openowner *oo;
+	struct nfs4_delegation *dp;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&nn->deleg_lock);
+	while (!list_empty(&clp->cl_delegations)) {
+		dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt);
+		unhash_delegation_locked(dp, SC_STATUS_CLOSED);
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&nn->deleg_lock);
+	while (!list_empty(&reaplist)) {
+		dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		destroy_unhashed_deleg(dp);
+	}
+	while (!list_empty(&clp->cl_revoked)) {
+		dp = list_entry(clp->cl_revoked.next, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		nfs4_put_stid(&dp->dl_stid);
+	}
+	while (!list_empty(&clp->cl_openowners)) {
+		oo = list_entry(clp->cl_openowners.next, struct nfs4_openowner, oo_perclient);
+		nfs4_get_stateowner(&oo->oo_owner);
+		release_openowner(oo);
+	}
+	for (i = 0; i < OWNER_HASH_SIZE; i++) {
+		struct nfs4_stateowner *so;
+
+		spin_lock(&clp->cl_lock);
+		while (!list_empty(&clp->cl_ownerstr_hashtbl[i])) {
+			so = list_first_entry(&clp->cl_ownerstr_hashtbl[i],
+					      struct nfs4_stateowner, so_strhash);
+			/* Should be no openowners at this point */
+			WARN_ON_ONCE(so->so_is_open_owner);
+			nfs4_get_stateowner(so);
+			unhash_lockowner_locked(lockowner(so));
+			spin_unlock(&clp->cl_lock);
+
+			remove_blocked_locks(lockowner(so));
+			nfs4_put_stateowner(so);
+
+			spin_lock(&clp->cl_lock);
+		}
+		spin_unlock(&clp->cl_lock);
+	}
+	nfsd4_return_all_client_layouts(clp);
+	nfsd4_shutdown_copy(clp);
+	nfsd4_shutdown_callback(clp);
+	if (clp->cl_cb_conn.cb_xprt)
+		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
+	atomic_add_unless(&nn->nfs4_client_count, -1, 0);
+	nfsd4_dec_courtesy_client_count(nn, clp);
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	xa_destroy(&clp->cl_dev_fences);
+#endif
+	free_client(clp);
+	wake_up_all(&expiry_wq);
+}
+
+static void
+destroy_client(struct nfs4_client *clp)
+{
+	unhash_client(clp);
+	__destroy_client(clp);
+}
+
+static void inc_reclaim_complete(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!test_bit(NFSD_NET_TRACK_RECLAIM_COMPLETES, &nn->flags))
+		return;
+
+	down_read(&nn->reclaim_str_hashtbl_lock);
+	if (!nfsd4_find_reclaim_client(clp->cl_name, nn)) {
+		up_read(&nn->reclaim_str_hashtbl_lock);
+		return;
+	}
+	if (atomic_inc_return(&nn->nr_reclaim_complete) ==
+			nn->reclaim_str_hashtbl_size) {
+		up_read(&nn->reclaim_str_hashtbl_lock);
+		printk(KERN_INFO "NFSD: all clients done reclaiming, ending NFSv4 grace period (net %x)\n",
+				clp->net->ns.inum);
+		nfsd4_end_grace(nn);
+		return;
+	}
+	up_read(&nn->reclaim_str_hashtbl_lock);
+}
+
+static void expire_client(struct nfs4_client *clp)
+{
+	unhash_client(clp);
+	nfsd4_client_record_remove(clp);
+	__destroy_client(clp);
+}
+
+static void copy_verf(struct nfs4_client *target, nfs4_verifier *source)
+{
+	memcpy(target->cl_verifier.data, source->data,
+			sizeof(target->cl_verifier.data));
+}
+
+static void copy_clid(struct nfs4_client *target, struct nfs4_client *source)
+{
+	target->cl_clientid.cl_boot = source->cl_clientid.cl_boot; 
+	target->cl_clientid.cl_id = source->cl_clientid.cl_id; 
+}
+
+static int copy_cred(struct svc_cred *target, struct svc_cred *source)
+{
+	target->cr_principal = kstrdup(source->cr_principal, GFP_KERNEL);
+	target->cr_raw_principal = kstrdup(source->cr_raw_principal,
+								GFP_KERNEL);
+	target->cr_targ_princ = kstrdup(source->cr_targ_princ, GFP_KERNEL);
+	if ((source->cr_principal && !target->cr_principal) ||
+	    (source->cr_raw_principal && !target->cr_raw_principal) ||
+	    (source->cr_targ_princ && !target->cr_targ_princ))
+		return -ENOMEM;
+
+	target->cr_flavor = source->cr_flavor;
+	target->cr_uid = source->cr_uid;
+	target->cr_gid = source->cr_gid;
+	target->cr_group_info = source->cr_group_info;
+	get_group_info(target->cr_group_info);
+	target->cr_gss_mech = source->cr_gss_mech;
+	if (source->cr_gss_mech)
+		gss_mech_get(source->cr_gss_mech);
+	return 0;
+}
+
+static int
+compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
+{
+	if (o1->len < o2->len)
+		return -1;
+	if (o1->len > o2->len)
+		return 1;
+	return memcmp(o1->data, o2->data, o1->len);
+}
+
+static int
+same_verf(nfs4_verifier *v1, nfs4_verifier *v2)
+{
+	return 0 == memcmp(v1->data, v2->data, sizeof(v1->data));
+}
+
+static int
+same_clid(clientid_t *cl1, clientid_t *cl2)
+{
+	return (cl1->cl_boot == cl2->cl_boot) && (cl1->cl_id == cl2->cl_id);
+}
+
+static bool groups_equal(struct group_info *g1, struct group_info *g2)
+{
+	int i;
+
+	if (g1->ngroups != g2->ngroups)
+		return false;
+	for (i=0; i<g1->ngroups; i++)
+		if (!gid_eq(g1->gid[i], g2->gid[i]))
+			return false;
+	return true;
+}
+
+/*
+ * RFC 3530 language requires clid_inuse be returned when the
+ * "principal" associated with a requests differs from that previously
+ * used.  We use uid, gid's, and gss principal string as our best
+ * approximation.  We also don't want to allow non-gss use of a client
+ * established using gss: in theory cr_principal should catch that
+ * change, but in practice cr_principal can be null even in the gss case
+ * since gssd doesn't always pass down a principal string.
+ */
+static bool is_gss_cred(struct svc_cred *cr)
+{
+	/* Is cr_flavor one of the gss "pseudoflavors"?: */
+	return (cr->cr_flavor > RPC_AUTH_MAXFLAVOR);
+}
+
+
+static bool
+same_creds(struct svc_cred *cr1, struct svc_cred *cr2)
+{
+	if ((is_gss_cred(cr1) != is_gss_cred(cr2))
+		|| (!uid_eq(cr1->cr_uid, cr2->cr_uid))
+		|| (!gid_eq(cr1->cr_gid, cr2->cr_gid))
+		|| !groups_equal(cr1->cr_group_info, cr2->cr_group_info))
+		return false;
+	/* XXX: check that cr_targ_princ fields match ? */
+	if (cr1->cr_principal == cr2->cr_principal)
+		return true;
+	if (!cr1->cr_principal || !cr2->cr_principal)
+		return false;
+	return 0 == strcmp(cr1->cr_principal, cr2->cr_principal);
+}
+
+static bool svc_rqst_integrity_protected(struct svc_rqst *rqstp)
+{
+	struct svc_cred *cr = &rqstp->rq_cred;
+	u32 service;
+
+	if (!cr->cr_gss_mech)
+		return false;
+	service = gss_pseudoflavor_to_service(cr->cr_gss_mech, cr->cr_flavor);
+	return service == RPC_GSS_SVC_INTEGRITY ||
+	       service == RPC_GSS_SVC_PRIVACY;
+}
+
+bool nfsd4_mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp)
+{
+	struct svc_cred *cr = &rqstp->rq_cred;
+
+	if (!cl->cl_mach_cred)
+		return true;
+	if (cl->cl_cred.cr_gss_mech != cr->cr_gss_mech)
+		return false;
+	if (!svc_rqst_integrity_protected(rqstp))
+		return false;
+	if (cl->cl_cred.cr_raw_principal)
+		return 0 == strcmp(cl->cl_cred.cr_raw_principal,
+						cr->cr_raw_principal);
+	if (!cr->cr_principal)
+		return false;
+	return 0 == strcmp(cl->cl_cred.cr_principal, cr->cr_principal);
+}
+
+static void gen_confirm(struct nfs4_client *clp, struct nfsd_net *nn)
+{
+	__be32 verf[2];
+
+	/*
+	 * This is opaque to client, so no need to byte-swap. Use
+	 * __force to keep sparse happy
+	 */
+	verf[0] = (__force __be32)(u32)ktime_get_real_seconds();
+	verf[1] = (__force __be32)nn->clverifier_counter++;
+	memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data));
+}
+
+static void gen_clid(struct nfs4_client *clp, struct nfsd_net *nn)
+{
+	clp->cl_clientid.cl_boot = (u32)nn->boot_time;
+	clp->cl_clientid.cl_id = nn->clientid_counter++;
+	gen_confirm(clp, nn);
+}
+
+static struct nfs4_stid *
+find_stateid_locked(struct nfs4_client *cl, stateid_t *t)
+{
+	struct nfs4_stid *ret;
+
+	ret = idr_find(&cl->cl_stateids, t->si_opaque.so_id);
+	if (!ret || !ret->sc_type)
+		return NULL;
+	/*
+	 * Copy offload stateids live in cl_stateids only for id allocation and
+	 * refcounting; per RFC 7862 they are not valid targets for generic
+	 * stateid ops (FREE_STATEID, TEST_STATEID, I/O). Hide them so those
+	 * paths return NFS4ERR_BAD_STATEID.
+	 */
+	if (ret->sc_type == SC_TYPE_COPY)
+		return NULL;
+	return ret;
+}
+
+static struct nfs4_stid *
+find_stateid_by_type(struct nfs4_client *cl, stateid_t *t,
+		     unsigned short typemask, unsigned short ok_states)
+{
+	struct nfs4_stid *s;
+
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, t);
+	if (s != NULL) {
+		if ((s->sc_status & ~ok_states) == 0 &&
+		    (typemask & s->sc_type))
+			refcount_inc(&s->sc_count);
+		else
+			s = NULL;
+	}
+	spin_unlock(&cl->cl_lock);
+	return s;
+}
+
+static struct nfs4_client *get_nfsdfs_clp(struct inode *inode)
+{
+	struct nfsdfs_client *nc;
+	nc = get_nfsdfs_client(inode);
+	if (!nc)
+		return NULL;
+	return container_of(nc, struct nfs4_client, cl_nfsdfs);
+}
+
+static void seq_quote_mem(struct seq_file *m, char *data, int len)
+{
+	seq_puts(m, "\"");
+	seq_escape_mem(m, data, len, ESCAPE_HEX | ESCAPE_NAP | ESCAPE_APPEND, "\"\\");
+	seq_puts(m, "\"");
+}
+
+static const char *cb_state2str(int state)
+{
+	switch (state) {
+	case NFSD4_CB_UP:
+		return "UP";
+	case NFSD4_CB_UNKNOWN:
+		return "UNKNOWN";
+	case NFSD4_CB_DOWN:
+		return "DOWN";
+	case NFSD4_CB_FAULT:
+		return "FAULT";
+	}
+	return "UNDEFINED";
+}
+
+static int client_info_show(struct seq_file *m, void *v)
+{
+	struct inode *inode = file_inode(m->file);
+	struct nfsd4_session *ses;
+	struct nfs4_client *clp;
+	u64 clid;
+
+	clp = get_nfsdfs_clp(inode);
+	if (!clp)
+		return -ENXIO;
+	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
+	seq_printf(m, "clientid: 0x%llx\n", clid);
+	seq_printf(m, "address: \"%pISpc\"\n", (struct sockaddr *)&clp->cl_addr);
+
+	if (clp->cl_state == NFSD4_COURTESY)
+		seq_puts(m, "status: courtesy\n");
+	else if (clp->cl_state == NFSD4_EXPIRABLE)
+		seq_puts(m, "status: expirable\n");
+	else if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
+		seq_puts(m, "status: confirmed\n");
+	else
+		seq_puts(m, "status: unconfirmed\n");
+	seq_printf(m, "seconds from last renew: %lld\n",
+		ktime_get_boottime_seconds() - clp->cl_time);
+	seq_puts(m, "name: ");
+	seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
+	seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
+	if (clp->cl_nii_domain.data) {
+		seq_puts(m, "Implementation domain: ");
+		seq_quote_mem(m, clp->cl_nii_domain.data,
+					clp->cl_nii_domain.len);
+		seq_puts(m, "\nImplementation name: ");
+		seq_quote_mem(m, clp->cl_nii_name.data, clp->cl_nii_name.len);
+		seq_printf(m, "\nImplementation time: [%lld, %ld]\n",
+			clp->cl_nii_time.tv_sec, clp->cl_nii_time.tv_nsec);
+	}
+	seq_printf(m, "callback state: %s\n", cb_state2str(clp->cl_cb_state));
+	seq_printf(m, "callback address: \"%pISpc\"\n", &clp->cl_cb_conn.cb_addr);
+	seq_printf(m, "admin-revoked states: %d\n",
+		   atomic_read(&clp->cl_admin_revoked));
+	spin_lock(&clp->cl_lock);
+	seq_printf(m, "session slots:");
+	list_for_each_entry(ses, &clp->cl_sessions, se_perclnt)
+		seq_printf(m, " %u", ses->se_fchannel.maxreqs);
+	seq_printf(m, "\nsession target slots:");
+	list_for_each_entry(ses, &clp->cl_sessions, se_perclnt)
+		seq_printf(m, " %u", ses->se_target_maxslots);
+	spin_unlock(&clp->cl_lock);
+	seq_puts(m, "\n");
+
+	nfsd4_put_client(clp);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(client_info);
+
+static void *states_start(struct seq_file *s, loff_t *pos)
+	__acquires(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	spin_lock(&clp->cl_lock);
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void *states_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	id = *pos;
+	id++;
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void states_stop(struct seq_file *s, void *v)
+	__releases(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+
+	spin_unlock(&clp->cl_lock);
+}
+
+static void nfs4_show_fname(struct seq_file *s, struct nfsd_file *f)
+{
+         seq_printf(s, "filename: \"%pD2\"", f->nf_file);
+}
+
+static void nfs4_show_superblock(struct seq_file *s, struct nfsd_file *f)
+{
+	struct inode *inode = file_inode(f->nf_file);
+
+	seq_printf(s, "superblock: \"%02x:%02x:%llu\"",
+					MAJOR(inode->i_sb->s_dev),
+					 MINOR(inode->i_sb->s_dev),
+					 inode->i_ino);
+}
+
+static void nfs4_show_owner(struct seq_file *s, struct nfs4_stateowner *oo)
+{
+	seq_puts(s, "owner: ");
+	seq_quote_mem(s, oo->so_owner.data, oo->so_owner.len);
+}
+
+static void nfs4_show_stateid(struct seq_file *s, stateid_t *stid)
+{
+	seq_printf(s, "0x%.8x", stid->si_generation);
+	seq_printf(s, "%12phN", &stid->si_opaque);
+}
+
+static int nfs4_show_open(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_ol_stateid *ols;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+	struct nfs4_stateowner *oo;
+	unsigned int access, deny;
+
+	ols = openlockstateid(st);
+	oo = ols->st_stateowner;
+	nf = st->sc_file;
+
+	seq_puts(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_puts(s, ": { type: open, ");
+
+	access = bmap_to_share_mode(ols->st_access_bmap);
+	deny   = bmap_to_share_mode(ols->st_deny_bmap);
+
+	seq_printf(s, "access: %s%s, ",
+		access & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		access & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+	seq_printf(s, "deny: %s%s, ",
+		deny & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		deny & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+
+	if (nf) {
+		spin_lock(&nf->fi_lock);
+		file = find_any_file_locked(nf);
+		if (file) {
+			nfs4_show_superblock(s, file);
+			seq_puts(s, ", ");
+			nfs4_show_fname(s, file);
+			seq_puts(s, ", ");
+		}
+		spin_unlock(&nf->fi_lock);
+	} else
+		seq_puts(s, "closed, ");
+	nfs4_show_owner(s, oo);
+	if (st->sc_status & SC_STATUS_ADMIN_REVOKED)
+		seq_puts(s, ", admin-revoked");
+	seq_puts(s, " }\n");
+	return 0;
+}
+
+static int nfs4_show_lock(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_ol_stateid *ols;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+	struct nfs4_stateowner *oo;
+
+	ols = openlockstateid(st);
+	oo = ols->st_stateowner;
+	nf = st->sc_file;
+
+	seq_puts(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_puts(s, ": { type: lock, ");
+
+	spin_lock(&nf->fi_lock);
+	file = find_any_file_locked(nf);
+	if (file) {
+		/*
+		 * Note: a lock stateid isn't really the same thing as a lock,
+		 * it's the locking state held by one owner on a file, and there
+		 * may be multiple (or no) lock ranges associated with it.
+		 * (Same for the matter is true of open stateids.)
+		 */
+
+		nfs4_show_superblock(s, file);
+		/* XXX: open stateid? */
+		seq_puts(s, ", ");
+		nfs4_show_fname(s, file);
+		seq_puts(s, ", ");
+	}
+	nfs4_show_owner(s, oo);
+	if (st->sc_status & SC_STATUS_ADMIN_REVOKED)
+		seq_puts(s, ", admin-revoked");
+	seq_puts(s, " }\n");
+	spin_unlock(&nf->fi_lock);
+	return 0;
+}
+
+static char *nfs4_show_deleg_type(u32 dl_type)
+{
+	switch (dl_type) {
+	case OPEN_DELEGATE_READ:
+		return "r";
+	case OPEN_DELEGATE_WRITE:
+		return "w";
+	case OPEN_DELEGATE_READ_ATTRS_DELEG:
+		return "ra";
+	case OPEN_DELEGATE_WRITE_ATTRS_DELEG:
+		return "wa";
+	}
+	return "?";
+}
+
+static int nfs4_show_deleg(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_delegation *ds;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+
+	ds = delegstateid(st);
+	nf = st->sc_file;
+
+	seq_puts(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_puts(s, ": { type: deleg, ");
+
+	seq_printf(s, "access: %s", nfs4_show_deleg_type(ds->dl_type));
+
+	/* XXX: lease time, whether it's being recalled. */
+
+	spin_lock(&nf->fi_lock);
+	file = rcu_dereference_protected(nf->fi_deleg_file,
+					 lockdep_is_held(&nf->fi_lock));
+	if (file) {
+		seq_puts(s, ", ");
+		nfs4_show_superblock(s, file);
+		seq_puts(s, ", ");
+		nfs4_show_fname(s, file);
+	}
+	spin_unlock(&nf->fi_lock);
+	if (st->sc_status & SC_STATUS_ADMIN_REVOKED)
+		seq_puts(s, ", admin-revoked");
+	seq_puts(s, " }\n");
+	return 0;
+}
+
+static int nfs4_show_layout(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfsd_file *file;
+
+	ls = container_of(st, struct nfs4_layout_stateid, ls_stid);
+
+	seq_puts(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_puts(s, ": { type: layout");
+
+	/* XXX: What else would be useful? */
+
+	spin_lock(&ls->ls_stid.sc_file->fi_lock);
+	file = ls->ls_file;
+	if (file) {
+		seq_puts(s, ", ");
+		nfs4_show_superblock(s, file);
+		seq_puts(s, ", ");
+		nfs4_show_fname(s, file);
+	}
+	spin_unlock(&ls->ls_stid.sc_file->fi_lock);
+	if (st->sc_status & SC_STATUS_ADMIN_REVOKED)
+		seq_puts(s, ", admin-revoked");
+	seq_puts(s, " }\n");
+
+	return 0;
+}
+
+static int states_show(struct seq_file *s, void *v)
+{
+	struct nfs4_stid *st = v;
+
+	switch (st->sc_type) {
+	case SC_TYPE_OPEN:
+		return nfs4_show_open(s, st);
+	case SC_TYPE_LOCK:
+		return nfs4_show_lock(s, st);
+	case SC_TYPE_DELEG:
+		return nfs4_show_deleg(s, st);
+	case SC_TYPE_LAYOUT:
+		return nfs4_show_layout(s, st);
+	default:
+		return 0; /* XXX: or SEQ_SKIP? */
+	}
+	/* XXX: copy stateids? */
+}
+
+static struct seq_operations states_seq_ops = {
+	.start = states_start,
+	.next = states_next,
+	.stop = states_stop,
+	.show = states_show
+};
+
+static int client_states_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *s;
+	struct nfs4_client *clp;
+	int ret;
+
+	clp = get_nfsdfs_clp(inode);
+	if (!clp)
+		return -ENXIO;
+
+	ret = seq_open(file, &states_seq_ops);
+	if (ret) {
+		nfsd4_put_client(clp);
+		return ret;
+	}
+	s = file->private_data;
+	s->private = clp;
+	return 0;
+}
+
+static int client_opens_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *m = file->private_data;
+	struct nfs4_client *clp = m->private;
+
+	/* XXX: alternatively, we could get/drop in seq start/stop */
+	nfsd4_put_client(clp);
+	return seq_release(inode, file);
+}
+
+static const struct file_operations client_states_fops = {
+	.open		= client_states_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= client_opens_release,
+};
+
+/*
+ * Normally we refuse to destroy clients that are in use, but here the
+ * administrator is telling us to just do it.  We also want to wait
+ * so the caller has a guarantee that the client's locks are gone by
+ * the time the write returns:
+ */
+static void force_expire_client(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	bool already_expired;
+
+	trace_nfsd_clid_admin_expired(&clp->cl_clientid);
+
+	/*
+	 * cl_time is cleared under client_lock before the wait so a
+	 * revocation walk pinning cl_rpc_users under it either skips
+	 * this client or is seen by this wait_event().
+	 */
+	spin_lock(&nn->client_lock);
+	clp->cl_time = 0;
+	spin_unlock(&nn->client_lock);
+
+	wait_event(expiry_wq, atomic_read(&clp->cl_rpc_users) == 0);
+	spin_lock(&nn->client_lock);
+	already_expired = list_empty(&clp->cl_lru);
+	if (!already_expired)
+		unhash_client_locked(clp);
+	spin_unlock(&nn->client_lock);
+
+	if (!already_expired)
+		expire_client(clp);
+	else
+		wait_event(expiry_wq, clp->cl_nfsd_dentry == NULL);
+}
+
+static ssize_t client_ctl_write(struct file *file, const char __user *buf,
+				   size_t size, loff_t *pos)
+{
+	char *data;
+	struct nfs4_client *clp;
+
+	data = simple_transaction_get(file, buf, size);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+	if (size != 7 || 0 != memcmp(data, "expire\n", 7))
+		return -EINVAL;
+	clp = get_nfsdfs_clp(file_inode(file));
+	if (!clp)
+		return -ENXIO;
+	force_expire_client(clp);
+	nfsd4_put_client(clp);
+	return 7;
+}
+
+static const struct file_operations client_ctl_fops = {
+	.write		= client_ctl_write,
+	.release	= simple_transaction_release,
+};
+
+static const struct tree_descr client_files[] = {
+	[0] = {"info", &client_info_fops, S_IRUSR},
+	[1] = {"states", &client_states_fops, S_IRUSR},
+	[2] = {"ctl", &client_ctl_fops, S_IWUSR},
+	[3] = {""},
+};
+
+static int
+nfsd4_cb_recall_any_done(struct nfsd4_callback *cb,
+				struct rpc_task *task)
+{
+	trace_nfsd_cb_recall_any_done(cb, task);
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_recall_any_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	nfsd4_put_client(clp);
+}
+
+static int
+nfsd4_cb_getattr_done(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	struct nfs4_cb_fattr *ncf =
+			container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+	struct nfs4_delegation *dp =
+			container_of(ncf, struct nfs4_delegation, dl_cb_fattr);
+
+	trace_nfsd_cb_getattr_done(&dp->dl_stid.sc_stateid, task);
+	ncf->ncf_cb_status = task->tk_status;
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_getattr_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_cb_fattr *ncf =
+			container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
+	struct nfs4_delegation *dp =
+			container_of(ncf, struct nfs4_delegation, dl_cb_fattr);
+
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
+{
+	bool queued;
+
+	if (test_and_set_bit(NFSD4_CALLBACK_RUNNING, &dp->dl_recall.cb_flags))
+		return;
+
+	/*
+	 * When called from the lease break (nfsd_break_deleg_cb()) the state
+	 * code is serialized by the flc_lock and the lease has not been
+	 * removed yet, so sc_count is known to be nonzero. The CB_NOTIFY
+	 * callback paths reach here from a workqueue without the flc_lock,
+	 * where the delegation may already be unhashed with sc_count at zero.
+	 * Use refcount_inc_not_zero() so both cases are safe, and bail if the
+	 * delegation is already being torn down.
+	 */
+	if (!refcount_inc_not_zero(&dp->dl_stid.sc_count)) {
+		clear_bit(NFSD4_CALLBACK_RUNNING, &dp->dl_recall.cb_flags);
+		return;
+	}
+	queued = nfsd4_run_cb(&dp->dl_recall);
+	WARN_ON_ONCE(!queued);
+	if (!queued) {
+		refcount_dec(&dp->dl_stid.sc_count);
+		clear_bit(NFSD4_CALLBACK_RUNNING, &dp->dl_recall.cb_flags);
+	}
+}
+
+static bool
+nfsd4_cb_notify_prepare(struct nfsd4_callback *cb)
+{
+	struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb);
+	struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
+	struct nfsd_notify_event *events[NOTIFY4_EVENT_QUEUE_SIZE];
+	struct xdr_buf xdr = { .buflen = PAGE_SIZE * NOTIFY4_PAGE_ARRAY_SIZE,
+			       .pages  = ncn->ncn_pages };
+	int limit = NOTIFY4_EVENT_QUEUE_SIZE;
+	struct xdr_stream stream;
+	struct nfsd_file *nf;
+	bool error = false;
+	int count, i;
+
+	/* Save a slot for dir attr update if requested */
+	if (dp->dl_notify_mask & BIT(NOTIFY4_CHANGE_DIR_ATTRS))
+		--limit;
+
+	/* Clear any failure recorded by a previous transmit. */
+	ncn->ncn_encode_err = false;
+
+	xdr_init_encode_pages(&stream, &xdr);
+
+	spin_lock(&ncn->ncn_lock);
+	count = ncn->ncn_evt_cnt;
+
+	/* spurious queueing? */
+	if (count == 0) {
+		spin_unlock(&ncn->ncn_lock);
+		return false;
+	}
+
+	memcpy(events, ncn->ncn_evt, sizeof(*events) * count);
+	ncn->ncn_evt_cnt = 0;
+	spin_unlock(&ncn->ncn_lock);
+
+	/*
+	 * We can't keep up! Drop the queued events and recall. The queue must
+	 * be drained here: out_recall leaves ncn_evt_cnt at 0, so the release
+	 * op won't see leftover events and requeue this callback forever.
+	 */
+	if (count > limit) {
+		for (i = 0; i < count; ++i)
+			nfsd_notify_event_put(events[i]);
+		goto out_recall;
+	}
+
+	rcu_read_lock();
+	nf = nfsd_file_get(rcu_dereference(dp->dl_stid.sc_file->fi_deleg_file));
+	rcu_read_unlock();
+	if (!nf) {
+		for (i = 0; i < count; ++i)
+			nfsd_notify_event_put(events[i]);
+		goto out_recall;
+	}
+
+	for (i = 0; i < count; ++i) {
+		struct nfsd_notify_event *nne = events[i];
+
+		if (!error) {
+			u32 *maskp = (u32 *)xdr_reserve_space(&stream, sizeof(*maskp));
+			u8 *p;
+
+			if (!maskp) {
+				error = true;
+				goto put_event;
+			}
+
+			p = nfsd4_encode_notify_event(&stream, nne, dp, nf, maskp);
+			if (!p) {
+				pr_notice("Could not generate CB_NOTIFY from fsnotify mask 0x%x\n",
+					  nne->ne_mask);
+				error = true;
+				goto put_event;
+			}
+
+			ncn->ncn_nf[i].notify_mask.count = 1;
+			ncn->ncn_nf[i].notify_mask.element = maskp;
+			ncn->ncn_nf[i].notify_vals.data = p;
+			ncn->ncn_nf[i].notify_vals.len = (u8 *)stream.p - p;
+		}
+put_event:
+		nfsd_notify_event_put(nne);
+	}
+	if (!error && (dp->dl_notify_mask & BIT(NOTIFY4_CHANGE_DIR_ATTRS))) {
+		u32 *maskp = (u32 *)xdr_reserve_space(&stream, sizeof(*maskp));
+		u8 *p;
+
+		if (maskp)
+			p = nfsd4_encode_dir_attr_change(&stream, dp, nf);
+		else
+			p = ERR_PTR(-ENOBUFS);
+
+		if (IS_ERR(p)) {
+			/*
+			 * The client asked to be told about dir attr changes
+			 * but the change could not be encoded. RFC 8881
+			 * s10.9.4 requires the server to recall the delegation
+			 * rather than drop a requested notification, so fall
+			 * through to recall. A NULL return instead means there
+			 * were no attributes to report, so omit the event in
+			 * that case.
+			 */
+			error = true;
+		} else if (p) {
+			*maskp = BIT(NOTIFY4_CHANGE_DIR_ATTRS);
+			ncn->ncn_nf[count].notify_mask.count = 1;
+			ncn->ncn_nf[count].notify_mask.element = maskp;
+			ncn->ncn_nf[count].notify_vals.data = p;
+			ncn->ncn_nf[count].notify_vals.len = (u8 *)stream.p - p;
+			++count;
+		}
+	}
+	if (!error) {
+		ncn->ncn_nf_cnt = count;
+		nfsd_file_put(nf);
+		return true;
+	}
+	nfsd_file_put(nf);
+out_recall:
+	nfsd_break_one_deleg(dp);
+	return false;
+}
+
+static int
+nfsd4_cb_notify_done(struct nfsd4_callback *cb,
+				struct rpc_task *task)
+{
+	struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb);
+	struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
+
+	if (dp->dl_stid.sc_status)
+		return 1;
+
+	/*
+	 * The CB_NOTIFY op overflowed the send buffer and was dropped from the
+	 * compound. The notification is lost, so recall the delegation rather
+	 * than leaving the client unaware of the directory change.
+	 */
+	if (ncn->ncn_encode_err) {
+		nfsd_break_one_deleg(dp);
+		return 1;
+	}
+
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	default:
+		/* For any other hard error, recall the deleg */
+		nfsd_break_one_deleg(dp);
+		fallthrough;
+	case 0:
+		return 1;
+	}
+}
+
+static void nfsd4_run_cb_notify(struct nfsd4_cb_notify *ncn);
+
+static void
+nfsd4_cb_notify_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_cb_notify *ncn =
+			container_of(cb, struct nfsd4_cb_notify, ncn_cb);
+	struct nfs4_delegation *dp =
+			container_of(ncn, struct nfs4_delegation, dl_cb_notify);
+
+	/*
+	 * Drain events that arrived while this callback was in flight, but
+	 * don't requeue against a revoked delegation: there's no point in
+	 * notifying a client that no longer holds it, and doing so can pin the
+	 * stid and spin the workqueue.
+	 */
+	if (!dp->dl_stid.sc_status && READ_ONCE(ncn->ncn_evt_cnt) > 0)
+		nfsd4_run_cb_notify(ncn);
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_any_ops = {
+	.done		= nfsd4_cb_recall_any_done,
+	.release	= nfsd4_cb_recall_any_release,
+	.opcode		= OP_CB_RECALL_ANY,
+};
+
+static const struct nfsd4_callback_ops nfsd4_cb_getattr_ops = {
+	.done		= nfsd4_cb_getattr_done,
+	.release	= nfsd4_cb_getattr_release,
+	.opcode		= OP_CB_GETATTR,
+};
+
+static const struct nfsd4_callback_ops nfsd4_cb_notify_ops = {
+	.prepare	= nfsd4_cb_notify_prepare,
+	.done		= nfsd4_cb_notify_done,
+	.release	= nfsd4_cb_notify_release,
+	.opcode		= OP_CB_NOTIFY,
+};
+
+static void nfs4_cb_getattr(struct nfs4_cb_fattr *ncf)
+{
+	struct nfs4_delegation *dp =
+			container_of(ncf, struct nfs4_delegation, dl_cb_fattr);
+
+	if (test_and_set_bit(NFSD4_CALLBACK_RUNNING, &ncf->ncf_getattr.cb_flags))
+		return;
+
+	/* set to proper status when nfsd4_cb_getattr_done runs */
+	ncf->ncf_cb_status = NFS4ERR_IO;
+
+	/* ensure that wake_bit is done when RUNNING is cleared */
+	set_bit(NFSD4_CALLBACK_WAKE, &ncf->ncf_getattr.cb_flags);
+
+	refcount_inc(&dp->dl_stid.sc_count);
+	nfsd4_run_cb(&ncf->ncf_getattr);
+}
+
+static struct nfs4_client *create_client(struct xdr_netobj name,
+		struct svc_rqst *rqstp, nfs4_verifier *verf)
+{
+	struct nfs4_client *clp;
+	struct sockaddr *sa = svc_addr(rqstp);
+	int ret;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct dentry *dentries[ARRAY_SIZE(client_files)];
+
+	clp = alloc_client(name, nn);
+	if (clp == NULL)
+		return NULL;
+
+	ret = copy_cred(&clp->cl_cred, &rqstp->rq_cred);
+	if (ret) {
+		free_client(clp);
+		return NULL;
+	}
+	gen_clid(clp, nn);
+	kref_init(&clp->cl_nfsdfs.cl_ref);
+	nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
+	clp->cl_time = ktime_get_boottime_seconds();
+	copy_verf(clp, verf);
+	memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage));
+	RCU_INIT_POINTER(clp->cl_cb_session, NULL);
+	clp->net = net;
+	clp->cl_nfsd_dentry = nfsd_client_mkdir(
+		nn, &clp->cl_nfsdfs,
+		clp->cl_clientid.cl_id - nn->clientid_base,
+		client_files, dentries);
+	clp->cl_nfsd_info_dentry = dentries[0];
+	if (!clp->cl_nfsd_dentry) {
+		free_client(clp);
+		return NULL;
+	}
+	clp->cl_ra = kzalloc_obj(*clp->cl_ra);
+	if (!clp->cl_ra) {
+		free_client(clp);
+		return NULL;
+	}
+	clp->cl_ra_time = 0;
+	nfsd4_init_cb(&clp->cl_ra->ra_cb, clp, &nfsd4_cb_recall_any_ops,
+			NFSPROC4_CLNT_CB_RECALL_ANY);
+	return clp;
+}
+
+static void
+add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
+{
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+	struct nfs4_client *clp;
+
+	while (*new) {
+		clp = rb_entry(*new, struct nfs4_client, cl_namenode);
+		parent = *new;
+
+		if (compare_blob(&clp->cl_name, &new_clp->cl_name) > 0)
+			new = &((*new)->rb_left);
+		else
+			new = &((*new)->rb_right);
+	}
+
+	rb_link_node(&new_clp->cl_namenode, parent, new);
+	rb_insert_color(&new_clp->cl_namenode, root);
+}
+
+static struct nfs4_client *
+find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
+{
+	int cmp;
+	struct rb_node *node = root->rb_node;
+	struct nfs4_client *clp;
+
+	while (node) {
+		clp = rb_entry(node, struct nfs4_client, cl_namenode);
+		cmp = compare_blob(&clp->cl_name, name);
+		if (cmp > 0)
+			node = node->rb_left;
+		else if (cmp < 0)
+			node = node->rb_right;
+		else
+			return clp;
+	}
+	return NULL;
+}
+
+static void
+add_to_unconfirmed(struct nfs4_client *clp)
+{
+	unsigned int idhashval;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	clear_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+	add_clp_to_name_tree(clp, &nn->unconf_name_tree);
+	idhashval = clientid_hashval(clp->cl_clientid.cl_id);
+	list_add(&clp->cl_idhash, &nn->unconf_id_hashtbl[idhashval]);
+	renew_client_locked(clp);
+}
+
+static void
+move_to_confirmed(struct nfs4_client *clp)
+{
+	unsigned int idhashval = clientid_hashval(clp->cl_clientid.cl_id);
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	list_move(&clp->cl_idhash, &nn->conf_id_hashtbl[idhashval]);
+	rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
+	add_clp_to_name_tree(clp, &nn->conf_name_tree);
+	set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+	trace_nfsd_clid_confirmed(&clp->cl_clientid);
+	renew_client_locked(clp);
+}
+
+static struct nfs4_client *
+find_client_in_id_table(struct list_head *tbl, clientid_t *clid, bool sessions)
+{
+	struct nfs4_client *clp;
+	unsigned int idhashval = clientid_hashval(clid->cl_id);
+
+	list_for_each_entry(clp, &tbl[idhashval], cl_idhash) {
+		if (same_clid(&clp->cl_clientid, clid)) {
+			if ((bool)clp->cl_minorversion != sessions)
+				return NULL;
+			renew_client_locked(clp);
+			return clp;
+		}
+	}
+	return NULL;
+}
+
+static struct nfs4_client *
+find_confirmed_client(clientid_t *clid, bool sessions, struct nfsd_net *nn)
+{
+	struct list_head *tbl = nn->conf_id_hashtbl;
+
+	lockdep_assert_held(&nn->client_lock);
+	return find_client_in_id_table(tbl, clid, sessions);
+}
+
+static struct nfs4_client *
+find_unconfirmed_client(clientid_t *clid, bool sessions, struct nfsd_net *nn)
+{
+	struct list_head *tbl = nn->unconf_id_hashtbl;
+
+	lockdep_assert_held(&nn->client_lock);
+	return find_client_in_id_table(tbl, clid, sessions);
+}
+
+static bool clp_used_exchangeid(struct nfs4_client *clp)
+{
+	return clp->cl_exchange_flags != 0;
+} 
+
+static struct nfs4_client *
+find_confirmed_client_by_name(struct xdr_netobj *name, struct nfsd_net *nn)
+{
+	lockdep_assert_held(&nn->client_lock);
+	return find_clp_in_name_tree(name, &nn->conf_name_tree);
+}
+
+static struct nfs4_client *
+find_unconfirmed_client_by_name(struct xdr_netobj *name, struct nfsd_net *nn)
+{
+	lockdep_assert_held(&nn->client_lock);
+	return find_clp_in_name_tree(name, &nn->unconf_name_tree);
+}
+
+static void
+gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se, struct svc_rqst *rqstp)
+{
+	struct nfs4_cb_conn *conn = &clp->cl_cb_conn;
+	struct sockaddr	*sa = svc_addr(rqstp);
+	u32 scopeid = rpc_get_scope_id(sa);
+	unsigned short expected_family;
+
+	/* Currently, we only support tcp and tcp6 for the callback channel */
+	if (se->se_callback_netid_len == 3 &&
+	    !memcmp(se->se_callback_netid_val, "tcp", 3))
+		expected_family = AF_INET;
+	else if (se->se_callback_netid_len == 4 &&
+		 !memcmp(se->se_callback_netid_val, "tcp6", 4))
+		expected_family = AF_INET6;
+	else
+		goto out_err;
+
+	conn->cb_addrlen = rpc_uaddr2sockaddr(clp->net, se->se_callback_addr_val,
+					    se->se_callback_addr_len,
+					    (struct sockaddr *)&conn->cb_addr,
+					    sizeof(conn->cb_addr));
+
+	if (!conn->cb_addrlen || conn->cb_addr.ss_family != expected_family)
+		goto out_err;
+
+	if (conn->cb_addr.ss_family == AF_INET6)
+		((struct sockaddr_in6 *)&conn->cb_addr)->sin6_scope_id = scopeid;
+
+	conn->cb_prog = se->se_callback_prog;
+	conn->cb_ident = se->se_callback_ident;
+	memcpy(&conn->cb_saddr, &rqstp->rq_daddr, rqstp->rq_daddrlen);
+	trace_nfsd_cb_args(clp, conn);
+	return;
+out_err:
+	conn->cb_addr.ss_family = AF_UNSPEC;
+	conn->cb_addrlen = 0;
+	trace_nfsd_cb_nodelegs(clp);
+	return;
+}
+
+/*
+ * Cache a reply. nfsd4_check_resp_size() has bounded the cache size.
+ */
+static void
+nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
+{
+	struct xdr_buf *buf = resp->xdr->buf;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+	unsigned int base;
+
+	/*
+	 * RFC 5661 Section 2.10.6.1.2:
+	 *
+	 * Any time SEQUENCE ... returns an error ... [t]he replier MUST NOT
+	 * modify the reply cache entry for the slot whenever an error is
+	 * returned from SEQUENCE ...
+	 *
+	 * Because nfsd4_store_cache_entry is called only by
+	 * nfsd4_sequence_done(), nfsd4_store_cache_entry() is called only
+	 * when a SEQUENCE operation was part of the COMPOUND.
+	 * nfs41_check_op_ordering() ensures SEQUENCE is the first op.
+	 */
+	if (resp->opcnt == 1 && resp->cstate.status != nfs_ok)
+		return;
+
+	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
+	slot->sl_opcnt = resp->opcnt;
+	slot->sl_status = resp->cstate.status;
+	free_svc_cred(&slot->sl_cred);
+	copy_cred(&slot->sl_cred, &resp->rqstp->rq_cred);
+
+	if (!(resp->cstate.slot->sl_flags & NFSD4_SLOT_CACHETHIS)) {
+		slot->sl_flags &= ~NFSD4_SLOT_CACHED;
+		return;
+	}
+	slot->sl_flags |= NFSD4_SLOT_CACHED;
+
+	base = resp->cstate.data_offset;
+	slot->sl_datalen = buf->len - base;
+	if (read_bytes_from_xdr_buf(buf, base, slot->sl_data, slot->sl_datalen))
+		WARN(1, "%s: sessions DRC could not cache compound\n",
+		     __func__);
+	return;
+}
+
+/*
+ * The sequence operation is not cached because we can use the slot and
+ * session values.
+ */
+static __be32
+nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
+			 struct nfsd4_sequence *seq)
+{
+	struct nfsd4_compoundargs *args = resp->rqstp->rq_argp;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	dprintk("--> %s slot %p\n", __func__, slot);
+
+	/* Always encode the SEQUENCE response. */
+	nfsd4_encode_operation(resp, &args->ops[0]);
+	if (args->opcnt == 1)
+		/* A solo SEQUENCE - nothing was cached */
+		return args->ops[0].status;
+
+	if (!(slot->sl_flags & NFSD4_SLOT_CACHED)) {
+		/* We weren't asked to cache this. */
+		struct nfsd4_op *op;
+
+		op = &args->ops[resp->opcnt++];
+		op->status = nfserr_retry_uncached_rep;
+		nfsd4_encode_operation(resp, op);
+		return op->status;
+	}
+
+	/* return reply from cache */
+	p = xdr_reserve_space(xdr, slot->sl_datalen);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		return nfserr_serverfault;
+	}
+	xdr_encode_opaque_fixed(p, slot->sl_data, slot->sl_datalen);
+	xdr_commit_encode(xdr);
+
+	resp->opcnt = slot->sl_opcnt;
+	return slot->sl_status;
+}
+
+/*
+ * Set the exchange_id flags returned by the server.
+ */
+static void
+nfsd4_set_ex_flags(struct nfs4_client *new, struct nfsd4_exchange_id *clid)
+{
+#ifdef CONFIG_NFSD_PNFS
+	new->cl_exchange_flags |= EXCHGID4_FLAG_USE_PNFS_MDS;
+#else
+	new->cl_exchange_flags |= EXCHGID4_FLAG_USE_NON_PNFS;
+#endif
+
+	/* Referrals are supported, Migration is not. */
+	new->cl_exchange_flags |= EXCHGID4_FLAG_SUPP_MOVED_REFER;
+
+	/* set the wire flags to return to client. */
+	clid->flags = new->cl_exchange_flags;
+}
+
+static bool client_has_openowners(struct nfs4_client *clp)
+{
+	struct nfs4_openowner *oo;
+
+	list_for_each_entry(oo, &clp->cl_openowners, oo_perclient) {
+		if (!list_empty(&oo->oo_owner.so_stateids))
+			return true;
+	}
+	return false;
+}
+
+static bool client_has_state(struct nfs4_client *clp)
+{
+	return client_has_openowners(clp)
+#ifdef CONFIG_NFSD_PNFS
+		|| !list_empty(&clp->cl_lo_states)
+#endif
+		|| !list_empty(&clp->cl_delegations)
+		|| !list_empty(&clp->cl_sessions)
+		|| nfsd4_has_active_async_copies(clp);
+}
+
+static __be32 copy_impl_id(struct nfs4_client *clp,
+				struct nfsd4_exchange_id *exid)
+{
+	if (!exid->nii_domain.data)
+		return 0;
+	xdr_netobj_dup(&clp->cl_nii_domain, &exid->nii_domain, GFP_KERNEL);
+	if (!clp->cl_nii_domain.data)
+		return nfserr_jukebox;
+	xdr_netobj_dup(&clp->cl_nii_name, &exid->nii_name, GFP_KERNEL);
+	if (!clp->cl_nii_name.data)
+		return nfserr_jukebox;
+	clp->cl_nii_time = exid->nii_time;
+	return 0;
+}
+
+__be32
+nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	struct nfs4_client *conf, *new;
+	struct nfs4_client *unconf = NULL;
+	__be32 status;
+	char			addr_str[INET6_ADDRSTRLEN];
+	nfs4_verifier		verf = exid->verifier;
+	struct sockaddr		*sa = svc_addr(rqstp);
+	bool	update = exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A;
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	rpc_ntop(sa, addr_str, sizeof(addr_str));
+	dprintk("%s rqstp=%p exid=%p clname.len=%u clname.data=%p "
+		"ip_addr=%s flags %x, spa_how %u\n",
+		__func__, rqstp, exid, exid->clname.len, exid->clname.data,
+		addr_str, exid->flags, exid->spa_how);
+
+	exid->server_impl_name = kasprintf(GFP_KERNEL, "%s %s %s %s",
+					   utsname()->sysname, utsname()->release,
+					   utsname()->version, utsname()->machine);
+	if (!exid->server_impl_name)
+		return nfserr_jukebox;
+
+	if (exid->flags & ~EXCHGID4_FLAG_MASK_A)
+		return nfserr_inval;
+
+	new = create_client(exid->clname, rqstp, &verf);
+	if (new == NULL)
+		return nfserr_jukebox;
+	status = copy_impl_id(new, exid);
+	if (status)
+		goto out_nolock;
+
+	switch (exid->spa_how) {
+	case SP4_MACH_CRED:
+		exid->spo_must_enforce[0] = 0;
+		exid->spo_must_enforce[1] = (
+			1 << (OP_BIND_CONN_TO_SESSION - 32) |
+			1 << (OP_EXCHANGE_ID - 32) |
+			1 << (OP_CREATE_SESSION - 32) |
+			1 << (OP_DESTROY_SESSION - 32) |
+			1 << (OP_DESTROY_CLIENTID - 32));
+
+		exid->spo_must_allow[0] &= (1 << (OP_CLOSE) |
+					1 << (OP_OPEN_DOWNGRADE) |
+					1 << (OP_LOCKU) |
+					1 << (OP_DELEGRETURN));
+
+		exid->spo_must_allow[1] &= (
+					1 << (OP_TEST_STATEID - 32) |
+					1 << (OP_FREE_STATEID - 32));
+		if (!svc_rqst_integrity_protected(rqstp)) {
+			status = nfserr_inval;
+			goto out_nolock;
+		}
+		/*
+		 * Sometimes userspace doesn't give us a principal.
+		 * Which is a bug, really.  Anyway, we can't enforce
+		 * MACH_CRED in that case, better to give up now:
+		 */
+		if (!new->cl_cred.cr_principal &&
+					!new->cl_cred.cr_raw_principal) {
+			status = nfserr_serverfault;
+			goto out_nolock;
+		}
+		new->cl_mach_cred = true;
+		break;
+	case SP4_NONE:
+		break;
+	default:				/* checked by xdr code */
+		WARN_ON_ONCE(1);
+		fallthrough;
+	case SP4_SSV:
+		status = nfserr_encr_alg_unsupp;
+		goto out_nolock;
+	}
+
+	/* Cases below refer to rfc 5661 section 18.35.4: */
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client_by_name(&exid->clname, nn);
+	if (conf) {
+		bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred);
+		bool verfs_match = same_verf(&verf, &conf->cl_verifier);
+
+		if (update) {
+			if (!clp_used_exchangeid(conf)) { /* buggy client */
+				status = nfserr_inval;
+				goto out;
+			}
+			if (!nfsd4_mach_creds_match(conf, rqstp)) {
+				status = nfserr_wrong_cred;
+				goto out;
+			}
+			if (!creds_match) { /* case 9 */
+				status = nfserr_perm;
+				goto out;
+			}
+			if (!verfs_match) { /* case 8 */
+				status = nfserr_not_same;
+				goto out;
+			}
+			/* case 6 */
+			exid->flags |= EXCHGID4_FLAG_CONFIRMED_R;
+			trace_nfsd_clid_confirmed_r(conf);
+			goto out_copy;
+		}
+		if (!creds_match) { /* case 3 */
+			if (client_has_state(conf)) {
+				status = nfserr_clid_inuse;
+				trace_nfsd_clid_cred_mismatch(conf, rqstp);
+				goto out;
+			}
+			goto out_new;
+		}
+		if (verfs_match) { /* case 2 */
+			conf->cl_exchange_flags |= EXCHGID4_FLAG_CONFIRMED_R;
+			trace_nfsd_clid_confirmed_r(conf);
+			goto out_copy;
+		}
+		/* case 5, client reboot */
+		trace_nfsd_clid_verf_mismatch(conf, rqstp, &verf);
+		conf = NULL;
+		goto out_new;
+	}
+
+	if (update) { /* case 7 */
+		status = nfserr_noent;
+		goto out;
+	}
+
+	unconf = find_unconfirmed_client_by_name(&exid->clname, nn);
+	if (unconf) /* case 4, possible retry or client restart */
+		unhash_client_locked(unconf);
+
+	/* case 1, new owner ID */
+	trace_nfsd_clid_fresh(new);
+
+out_new:
+	if (conf) {
+		status = mark_client_expired_locked(conf);
+		if (status)
+			goto out;
+		trace_nfsd_clid_replaced(&conf->cl_clientid);
+	}
+	new->cl_minorversion = cstate->minorversion;
+	new->cl_spo_must_allow.u.words[0] = exid->spo_must_allow[0];
+	new->cl_spo_must_allow.u.words[1] = exid->spo_must_allow[1];
+
+	/* Contrived initial CREATE_SESSION response */
+	new->cl_cs_slot.sl_status = nfserr_seq_misordered;
+
+	add_to_unconfirmed(new);
+	swap(new, conf);
+out_copy:
+	exid->clientid.cl_boot = conf->cl_clientid.cl_boot;
+	exid->clientid.cl_id = conf->cl_clientid.cl_id;
+
+	exid->seqid = conf->cl_cs_slot.sl_seqid + 1;
+	nfsd4_set_ex_flags(conf, exid);
+
+	exid->nii_domain.len = sizeof("kernel.org") - 1;
+	exid->nii_domain.data = "kernel.org";
+
+	/*
+	 * Note that RFC 8881 places no length limit on
+	 * nii_name, but this implementation permits no
+	 * more than NFS4_OPAQUE_LIMIT bytes.
+	 */
+	exid->nii_name.len = strlen(exid->server_impl_name);
+	if (exid->nii_name.len > NFS4_OPAQUE_LIMIT)
+		exid->nii_name.len = NFS4_OPAQUE_LIMIT;
+	exid->nii_name.data = exid->server_impl_name;
+
+	/* just send zeros - the date is in nii_name */
+	exid->nii_time.tv_sec = 0;
+	exid->nii_time.tv_nsec = 0;
+
+	dprintk("nfsd4_exchange_id seqid %d flags %x\n",
+		conf->cl_cs_slot.sl_seqid, conf->cl_exchange_flags);
+	status = nfs_ok;
+
+out:
+	spin_unlock(&nn->client_lock);
+out_nolock:
+	if (new)
+		expire_client(new);
+	if (unconf) {
+		trace_nfsd_clid_expire_unconf(&unconf->cl_clientid);
+		expire_client(unconf);
+	}
+	return status;
+}
+
+void
+nfsd4_exchange_id_release(union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+
+	kfree(exid->server_impl_name);
+}
+
+static __be32 check_slot_seqid(u32 seqid, u32 slot_seqid, u8 flags)
+{
+	/* The slot is in use, and no response has been sent. */
+	if (flags & NFSD4_SLOT_INUSE) {
+		if (seqid == slot_seqid)
+			return nfserr_jukebox;
+		else
+			return nfserr_seq_misordered;
+	}
+	/* Note unsigned 32-bit arithmetic handles wraparound: */
+	if (likely(seqid == slot_seqid + 1))
+		return nfs_ok;
+	if ((flags & NFSD4_SLOT_REUSED) && seqid == 1)
+		return nfs_ok;
+	if (seqid == slot_seqid)
+		return nfserr_replay_cache;
+	return nfserr_seq_misordered;
+}
+
+/*
+ * Cache the create session result into the create session single DRC
+ * slot cache by saving the xdr structure. sl_seqid has been set.
+ * Do this for solo or embedded create session operations.
+ */
+static void
+nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
+			   struct nfsd4_clid_slot *slot, __be32 nfserr)
+{
+	slot->sl_status = nfserr;
+	memcpy(&slot->sl_cr_ses, cr_ses, sizeof(*cr_ses));
+}
+
+static __be32
+nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses,
+			    struct nfsd4_clid_slot *slot)
+{
+	memcpy(cr_ses, &slot->sl_cr_ses, sizeof(*cr_ses));
+	return slot->sl_status;
+}
+
+#define NFSD_MIN_REQ_HDR_SEQ_SZ	((\
+			2 * 2 + /* credential,verifier: AUTH_NULL, length 0 */ \
+			1 +	/* MIN tag is length with zero, only length */ \
+			3 +	/* version, opcount, opcode */ \
+			XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				/* seqid, slotID, slotID, cache */ \
+			4 ) * sizeof(__be32))
+
+#define NFSD_MIN_RESP_HDR_SEQ_SZ ((\
+			2 +	/* verifier: AUTH_NULL, length 0 */\
+			1 +	/* status */ \
+			1 +	/* MIN tag is length with zero, only length */ \
+			3 +	/* opcount, opcode, opstatus*/ \
+			XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				/* seqid, slotID, slotID, slotID, status */ \
+			5 ) * sizeof(__be32))
+
+static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn)
+{
+	u32 maxrpc = nn->nfsd_serv->sv_max_mesg;
+
+	if (ca->maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ)
+		return nfserr_toosmall;
+	if (ca->maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ)
+		return nfserr_toosmall;
+	ca->headerpadsz = 0;
+	ca->maxreq_sz = min_t(u32, ca->maxreq_sz, maxrpc);
+	ca->maxresp_sz = min_t(u32, ca->maxresp_sz, maxrpc);
+	ca->maxops = min_t(u32, ca->maxops, NFSD_MAX_OPS_PER_COMPOUND);
+	ca->maxresp_cached = min_t(u32, ca->maxresp_cached,
+			NFSD_SLOT_CACHE_SIZE + NFSD_MIN_HDR_SEQ_SZ);
+	ca->maxreqs = min_t(u32, ca->maxreqs, NFSD_MAX_SLOTS_PER_SESSION);
+
+	return nfs_ok;
+}
+
+/*
+ * Server's NFSv4.1 backchannel support is AUTH_SYS-only for now.
+ * These are based on similar macros in linux/sunrpc/msg_prot.h .
+ */
+#define RPC_MAX_HEADER_WITH_AUTH_SYS \
+	(RPC_CALLHDRSIZE + 2 * (2 + UNX_CALLSLACK))
+
+#define RPC_MAX_REPHEADER_WITH_AUTH_SYS \
+	(RPC_REPHDRSIZE + (2 + NUL_REPLYSLACK))
+
+#define NFSD_CB_MAX_REQ_SZ	((NFS4_enc_cb_recall_sz + \
+				 RPC_MAX_HEADER_WITH_AUTH_SYS) * sizeof(__be32))
+#define NFSD_CB_MAX_RESP_SZ	((NFS4_dec_cb_recall_sz + \
+				 RPC_MAX_REPHEADER_WITH_AUTH_SYS) * \
+				 sizeof(__be32))
+
+static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs *ca)
+{
+	ca->headerpadsz = 0;
+
+	if (ca->maxreq_sz < NFSD_CB_MAX_REQ_SZ)
+		return nfserr_toosmall;
+	if (ca->maxresp_sz < NFSD_CB_MAX_RESP_SZ)
+		return nfserr_toosmall;
+	ca->maxresp_cached = 0;
+	if (ca->maxops < 2)
+		return nfserr_toosmall;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_check_cb_sec(struct nfsd4_cb_sec *cbs)
+{
+	switch (cbs->flavor) {
+	case RPC_AUTH_NULL:
+	case RPC_AUTH_UNIX:
+		return nfs_ok;
+	default:
+		/*
+		 * GSS case: the spec doesn't allow us to return this
+		 * error.  But it also doesn't allow us not to support
+		 * GSS.
+		 * I'd rather this fail hard than return some error the
+		 * client might think it can already handle:
+		 */
+		return nfserr_encr_alg_unsupp;
+	}
+}
+
+__be32
+nfsd4_create_session(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *cr_ses = &u->create_session;
+	struct sockaddr *sa = svc_addr(rqstp);
+	struct nfs4_client *conf, *unconf;
+	struct nfsd4_clid_slot *cs_slot;
+	struct nfs4_client *old = NULL;
+	struct nfsd4_session *new;
+	struct nfsd4_conn *conn;
+	__be32 status = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
+		return nfserr_inval;
+	status = nfsd4_check_cb_sec(&cr_ses->cb_sec);
+	if (status)
+		return status;
+	status = check_forechannel_attrs(&cr_ses->fore_channel, nn);
+	if (status)
+		return status;
+	status = check_backchannel_attrs(&cr_ses->back_channel);
+	if (status)
+		goto out_err;
+	status = nfserr_jukebox;
+	new = alloc_session(&cr_ses->fore_channel, &cr_ses->back_channel);
+	if (!new)
+		goto out_err;
+	conn = alloc_conn_from_crses(rqstp, cr_ses);
+	if (!conn)
+		goto out_free_session;
+
+	spin_lock(&nn->client_lock);
+
+	/* RFC 8881 Section 18.36.4 Phase 1: Client record look-up. */
+	unconf = find_unconfirmed_client(&cr_ses->clientid, true, nn);
+	conf = find_confirmed_client(&cr_ses->clientid, true, nn);
+	if (!conf && !unconf) {
+		status = nfserr_stale_clientid;
+		goto out_free_conn;
+	}
+
+	/* RFC 8881 Section 18.36.4 Phase 2: Sequence ID processing. */
+	if (conf) {
+		cs_slot = &conf->cl_cs_slot;
+		trace_nfsd_slot_seqid_conf(conf, cr_ses);
+	} else {
+		cs_slot = &unconf->cl_cs_slot;
+		trace_nfsd_slot_seqid_unconf(unconf, cr_ses);
+	}
+	status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
+	switch (status) {
+	case nfs_ok:
+		cs_slot->sl_seqid++;
+		cr_ses->seqid = cs_slot->sl_seqid;
+		break;
+	case nfserr_replay_cache:
+		status = nfsd4_replay_create_session(cr_ses, cs_slot);
+		fallthrough;
+	case nfserr_jukebox:
+		/* The server MUST NOT cache NFS4ERR_DELAY */
+		goto out_free_conn;
+	default:
+		goto out_cache_error;
+	}
+
+	/* RFC 8881 Section 18.36.4 Phase 3: Client ID confirmation. */
+	if (conf) {
+		status = nfserr_wrong_cred;
+		if (!nfsd4_mach_creds_match(conf, rqstp))
+			goto out_cache_error;
+	} else {
+		status = nfserr_clid_inuse;
+		if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
+		    !rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) {
+			trace_nfsd_clid_cred_mismatch(unconf, rqstp);
+			goto out_cache_error;
+		}
+		status = nfserr_wrong_cred;
+		if (!nfsd4_mach_creds_match(unconf, rqstp))
+			goto out_cache_error;
+		old = find_confirmed_client_by_name(&unconf->cl_name, nn);
+		if (old) {
+			status = mark_client_expired_locked(old);
+			if (status)
+				goto out_expired_error;
+			trace_nfsd_clid_replaced(&old->cl_clientid);
+		}
+		move_to_confirmed(unconf);
+		conf = unconf;
+	}
+
+	/* RFC 8881 Section 18.36.4 Phase 4: Session creation. */
+	status = nfs_ok;
+	/* Persistent sessions are not supported */
+	cr_ses->flags &= ~SESSION4_PERSIST;
+	/* Upshifting from TCP to RDMA is not supported */
+	cr_ses->flags &= ~SESSION4_RDMA;
+	/* Report the correct number of backchannel slots */
+	cr_ses->back_channel.maxreqs = new->se_cb_highest_slot + 1;
+
+	init_session(rqstp, new, conf, cr_ses);
+	nfsd4_get_session_locked(new);
+
+	memcpy(cr_ses->sessionid.data, new->se_sessionid.data,
+	       NFS4_MAX_SESSIONID_LEN);
+
+	/* cache solo and embedded create sessions under the client_lock */
+	nfsd4_cache_create_session(cr_ses, cs_slot, status);
+	spin_unlock(&nn->client_lock);
+	if (conf == unconf)
+		fsnotify_dentry(conf->cl_nfsd_info_dentry, FS_MODIFY);
+	/* init connection and backchannel */
+	nfsd4_init_conn(rqstp, conn, new);
+	nfsd4_put_session(new);
+	if (old)
+		expire_client(old);
+	return status;
+
+out_expired_error:
+	/*
+	 * Revert the slot seq_nr change so the server will process
+	 * the client's resend instead of returning a cached response.
+	 */
+	if (status == nfserr_jukebox) {
+		cs_slot->sl_seqid--;
+		cr_ses->seqid = cs_slot->sl_seqid;
+		goto out_free_conn;
+	}
+out_cache_error:
+	nfsd4_cache_create_session(cr_ses, cs_slot, status);
+out_free_conn:
+	spin_unlock(&nn->client_lock);
+	free_conn(conn);
+out_free_session:
+	__free_session(new);
+out_err:
+	return status;
+}
+
+static __be32 nfsd4_map_bcts_dir(u32 *dir)
+{
+	switch (*dir) {
+	case NFS4_CDFC4_FORE:
+	case NFS4_CDFC4_BACK:
+		return nfs_ok;
+	case NFS4_CDFC4_FORE_OR_BOTH:
+	case NFS4_CDFC4_BACK_OR_BOTH:
+		*dir = NFS4_CDFC4_BOTH;
+		return nfs_ok;
+	}
+	return nfserr_inval;
+}
+
+__be32 nfsd4_backchannel_ctl(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
+	struct nfsd4_session *session = cstate->session;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	__be32 status;
+
+	status = nfsd4_check_cb_sec(&bc->bc_cb_sec);
+	if (status)
+		return status;
+	spin_lock(&nn->client_lock);
+	session->se_cb_prog = bc->bc_cb_program;
+	session->se_cb_sec = bc->bc_cb_sec;
+	spin_unlock(&nn->client_lock);
+
+	nfsd4_probe_callback(session->se_client);
+
+	return nfs_ok;
+}
+
+static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_session *s)
+{
+	struct nfsd4_conn *c;
+
+	list_for_each_entry(c, &s->se_conns, cn_persession) {
+		if (c->cn_xprt == xpt) {
+			return c;
+		}
+	}
+	return NULL;
+}
+
+static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
+		struct nfsd4_session *session, u32 req, struct nfsd4_conn **conn)
+{
+	struct nfs4_client *clp = session->se_client;
+	struct svc_xprt *xpt = rqst->rq_xprt;
+	struct nfsd4_conn *c;
+	__be32 status;
+
+	/* Following the last paragraph of RFC 5661 Section 18.34.3: */
+	spin_lock(&clp->cl_lock);
+	c = __nfsd4_find_conn(xpt, session);
+	if (!c)
+		status = nfserr_noent;
+	else if (req == c->cn_flags)
+		status = nfs_ok;
+	else if (req == NFS4_CDFC4_FORE_OR_BOTH &&
+				c->cn_flags != NFS4_CDFC4_BACK)
+		status = nfs_ok;
+	else if (req == NFS4_CDFC4_BACK_OR_BOTH &&
+				c->cn_flags != NFS4_CDFC4_FORE)
+		status = nfs_ok;
+	else
+		status = nfserr_inval;
+	spin_unlock(&clp->cl_lock);
+	if (status == nfs_ok && conn)
+		*conn = c;
+	return status;
+}
+
+__be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	__be32 status;
+	struct nfsd4_conn *conn;
+	struct nfsd4_session *session;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (!nfsd4_last_compound_op(rqstp))
+		return nfserr_not_only_op;
+	spin_lock(&nn->client_lock);
+	session = find_in_sessionid_hashtbl(&bcts->sessionid, net, &status);
+	spin_unlock(&nn->client_lock);
+	if (!session)
+		goto out_no_session;
+	status = nfserr_wrong_cred;
+	if (!nfsd4_mach_creds_match(session->se_client, rqstp))
+		goto out;
+	status = nfsd4_match_existing_connection(rqstp, session,
+			bcts->dir, &conn);
+	if (status == nfs_ok) {
+		if (bcts->dir == NFS4_CDFC4_FORE_OR_BOTH ||
+				bcts->dir == NFS4_CDFC4_BACK)
+			conn->cn_flags |= NFS4_CDFC4_BACK;
+		nfsd4_probe_callback(session->se_client);
+		goto out;
+	}
+	if (status == nfserr_inval)
+		goto out;
+	status = nfsd4_map_bcts_dir(&bcts->dir);
+	if (status)
+		goto out;
+	conn = alloc_conn(rqstp, bcts->dir);
+	status = nfserr_jukebox;
+	if (!conn)
+		goto out;
+	nfsd4_init_conn(rqstp, conn, session);
+	status = nfs_ok;
+out:
+	nfsd4_put_session(session);
+out_no_session:
+	return status;
+}
+
+static bool nfsd4_compound_in_session(struct nfsd4_compound_state *cstate, struct nfs4_sessionid *sid)
+{
+	if (!cstate->session)
+		return false;
+	return !memcmp(sid, &cstate->session->se_sessionid, sizeof(*sid));
+}
+
+__be32
+nfsd4_destroy_session(struct svc_rqst *r, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfs4_sessionid *sessionid = &u->destroy_session.sessionid;
+	struct nfsd4_session *ses;
+	__be32 status;
+	int ref_held_by_me = 0;
+	struct net *net = SVC_NET(r);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	status = nfserr_not_only_op;
+	if (nfsd4_compound_in_session(cstate, sessionid)) {
+		if (!nfsd4_last_compound_op(r))
+			goto out;
+		ref_held_by_me++;
+	}
+	dump_sessionid(__func__, sessionid);
+	spin_lock(&nn->client_lock);
+	ses = find_in_sessionid_hashtbl(sessionid, net, &status);
+	if (!ses)
+		goto out_client_lock;
+	status = nfserr_wrong_cred;
+	if (!nfsd4_mach_creds_match(ses->se_client, r))
+		goto out_put_session;
+	status = mark_session_dead_locked(ses, 1 + ref_held_by_me);
+	if (status)
+		goto out_put_session;
+	unhash_session(ses);
+	spin_unlock(&nn->client_lock);
+
+	nfsd4_probe_callback_sync(ses->se_client);
+
+	spin_lock(&nn->client_lock);
+	status = nfs_ok;
+out_put_session:
+	nfsd4_put_session_locked(ses);
+out_client_lock:
+	spin_unlock(&nn->client_lock);
+out:
+	return status;
+}
+
+static __be32 nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd4_conn *c;
+	__be32 status = nfs_ok;
+	int ret;
+
+	spin_lock(&clp->cl_lock);
+	c = __nfsd4_find_conn(new->cn_xprt, ses);
+	if (c)
+		goto out_free;
+	status = nfserr_conn_not_bound_to_session;
+	if (clp->cl_mach_cred)
+		goto out_free;
+	__nfsd4_hash_conn(new, ses);
+	spin_unlock(&clp->cl_lock);
+	ret = nfsd4_register_conn(new);
+	if (ret)
+		/* oops; xprt is already down: */
+		nfsd4_conn_lost(&new->cn_xpt_user);
+	return nfs_ok;
+out_free:
+	spin_unlock(&clp->cl_lock);
+	free_conn(new);
+	return status;
+}
+
+static bool nfsd4_session_too_many_ops(struct svc_rqst *rqstp, struct nfsd4_session *session)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	return args->opcnt > session->se_fchannel.maxops;
+}
+
+static bool nfsd4_request_too_big(struct svc_rqst *rqstp,
+				  struct nfsd4_session *session)
+{
+	struct xdr_buf *xb = &rqstp->rq_arg;
+
+	return xb->len > session->se_fchannel.maxreq_sz;
+}
+
+static bool replay_matches_cache(struct svc_rqst *rqstp,
+		 struct nfsd4_sequence *seq, struct nfsd4_slot *slot)
+{
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	if ((bool)(slot->sl_flags & NFSD4_SLOT_CACHETHIS) !=
+	    (bool)seq->cachethis)
+		return false;
+	/*
+	 * If there's an error then the reply can have fewer ops than
+	 * the call.
+	 */
+	if (slot->sl_opcnt < argp->opcnt && !slot->sl_status)
+		return false;
+	/*
+	 * But if we cached a reply with *more* ops than the call you're
+	 * sending us now, then this new call is clearly not really a
+	 * replay of the old one:
+	 */
+	if (slot->sl_opcnt > argp->opcnt)
+		return false;
+	/* This is the only check explicitly called by spec: */
+	if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))
+		return false;
+	/*
+	 * There may be more comparisons we could actually do, but the
+	 * spec doesn't require us to catch every case where the calls
+	 * don't match (that would require caching the call as well as
+	 * the reply), so we don't bother.
+	 */
+	return true;
+}
+
+/*
+ * Note that the response is constructed here both for the case
+ * of a new SEQUENCE request and for a replayed SEQUENCE request.
+ * We do not cache SEQUENCE responses as SEQUENCE is idempotent.
+ */
+static void nfsd4_construct_sequence_response(struct nfsd4_session *session,
+					      struct nfsd4_sequence *seq)
+{
+	struct nfs4_client *clp = session->se_client;
+
+	seq->maxslots_response = max(session->se_target_maxslots,
+				     seq->maxslots);
+	seq->target_maxslots = session->se_target_maxslots;
+
+	switch (clp->cl_cb_state) {
+	case NFSD4_CB_DOWN:
+		seq->status_flags = SEQ4_STATUS_CB_PATH_DOWN;
+		break;
+	case NFSD4_CB_FAULT:
+		seq->status_flags = SEQ4_STATUS_BACKCHANNEL_FAULT;
+		break;
+	default:
+		seq->status_flags = 0;
+	}
+	if (!list_empty(&clp->cl_revoked))
+		seq->status_flags |= SEQ4_STATUS_RECALLABLE_STATE_REVOKED;
+	if (atomic_read(&clp->cl_admin_revoked))
+		seq->status_flags |= SEQ4_STATUS_ADMIN_STATE_REVOKED;
+}
+
+static bool nfsd4_slots_inuse(struct nfsd4_session *ses, int from)
+{
+	int i;
+
+	for (i = from; i < ses->se_fchannel.maxreqs; i++) {
+		struct nfsd4_slot *slot = xa_load(&ses->se_slots, i);
+
+		if (slot->sl_flags & NFSD4_SLOT_INUSE)
+			return true;
+	}
+	return false;
+}
+
+__be32
+nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct xdr_stream *xdr = resp->xdr;
+	struct nfsd4_session *session;
+	struct nfs4_client *clp;
+	struct nfsd4_slot *slot;
+	struct nfsd4_conn *conn;
+	__be32 status;
+	int buflen;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (resp->opcnt != 1)
+		return nfserr_sequence_pos;
+
+	/*
+	 * Will be either used or freed by nfsd4_sequence_check_conn
+	 * below.
+	 */
+	conn = alloc_conn(rqstp, NFS4_CDFC4_FORE);
+	if (!conn)
+		return nfserr_jukebox;
+
+	spin_lock(&nn->client_lock);
+	session = find_in_sessionid_hashtbl(&seq->sessionid, net, &status);
+	if (!session)
+		goto out_no_session;
+	clp = session->se_client;
+
+	status = nfserr_too_many_ops;
+	if (nfsd4_session_too_many_ops(rqstp, session))
+		goto out_put_session;
+
+	status = nfserr_req_too_big;
+	if (nfsd4_request_too_big(rqstp, session))
+		goto out_put_session;
+
+	status = nfserr_badslot;
+	if (seq->slotid >= session->se_fchannel.maxreqs)
+		goto out_put_session;
+
+	slot = xa_load(&session->se_slots, seq->slotid);
+	dprintk("%s: slotid %d\n", __func__, seq->slotid);
+
+	trace_nfsd_slot_seqid_sequence(clp, seq, slot);
+
+	nfsd4_construct_sequence_response(session, seq);
+
+	status = check_slot_seqid(seq->seqid, slot->sl_seqid, slot->sl_flags);
+	if (status == nfserr_replay_cache) {
+		status = nfserr_seq_misordered;
+		if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED))
+			goto out_put_session;
+		status = nfserr_seq_false_retry;
+		if (!replay_matches_cache(rqstp, seq, slot))
+			goto out_put_session;
+		cstate->slot = slot;
+		cstate->session = session;
+		cstate->clp = clp;
+		/* Return the cached reply status and set cstate->status
+		 * for nfsd4_proc_compound processing */
+		status = nfsd4_replay_cache_entry(resp, seq);
+		cstate->status = nfserr_replay_cache;
+		goto out;
+	}
+	if (status)
+		goto out_put_session;
+
+	status = nfsd4_sequence_check_conn(conn, session);
+	conn = NULL;
+	if (status)
+		goto out_put_session;
+
+	if (session->se_target_maxslots < session->se_fchannel.maxreqs &&
+	    slot->sl_generation == session->se_slot_gen &&
+	    seq->maxslots <= session->se_target_maxslots &&
+	    seq->slotid < session->se_target_maxslots &&
+	    !nfsd4_slots_inuse(session, session->se_target_maxslots))
+		/* Client acknowledged our reduce maxreqs */
+		free_session_slots(session, session->se_target_maxslots);
+
+	buflen = (seq->cachethis) ?
+			session->se_fchannel.maxresp_cached :
+			session->se_fchannel.maxresp_sz;
+	status = (seq->cachethis) ? nfserr_rep_too_big_to_cache :
+				    nfserr_rep_too_big;
+	if (xdr_restrict_buflen(xdr, buflen - rqstp->rq_auth_slack))
+		goto out_put_session;
+	svc_reserve_auth(rqstp, buflen);
+
+	status = nfs_ok;
+	/* Success! accept new slot seqid */
+	slot->sl_seqid = seq->seqid;
+	slot->sl_flags &= ~NFSD4_SLOT_REUSED;
+	slot->sl_flags |= NFSD4_SLOT_INUSE;
+	slot->sl_generation = session->se_slot_gen;
+	if (seq->cachethis)
+		slot->sl_flags |= NFSD4_SLOT_CACHETHIS;
+	else
+		slot->sl_flags &= ~NFSD4_SLOT_CACHETHIS;
+
+	cstate->slot = slot;
+	cstate->session = session;
+	cstate->clp = clp;
+
+	/*
+	 * If the client ever uses the highest available slot,
+	 * gently try to allocate another 20%.  This allows
+	 * fairly quick growth without grossly over-shooting what
+	 * the client might use.
+	 *
+	 * Bound that growth by the service's thread ceiling:
+	 * slots beyond the nfsd thread count cannot raise this
+	 * client's throughput, only deepen its backlog.  Cap each
+	 * session independently, since a session cannot use
+	 * another's slots; a shared budget would let idle sessions
+	 * pin an active client small.  Compare against the
+	 * configured maximum, not the running thread count, so a
+	 * client resuming from idle can grow back before the pool
+	 * scales up.
+	 */
+	if (seq->slotid == session->se_fchannel.maxreqs - 1 &&
+	    session->se_target_maxslots >= session->se_fchannel.maxreqs) {
+		int s = session->se_fchannel.maxreqs;
+		int ceiling = min_t(int, NFSD_MAX_SLOTS_PER_SESSION,
+				    svc_serv_maxthreads(rqstp->rq_server));
+		int cnt = min(DIV_ROUND_UP(s, 5), ceiling - s);
+		void *prev_slot;
+
+		while (cnt-- > 0) {
+			/*
+			 * GFP_NOWAIT both allows allocation under a
+			 * spinlock, and only succeeds if there is
+			 * plenty of memory.
+			 */
+			slot = nfsd4_alloc_slot(&session->se_fchannel, s,
+						GFP_NOWAIT);
+			if (!slot)
+				break;
+			prev_slot = xa_load(&session->se_slots, s);
+			if (xa_is_value(prev_slot)) {
+				slot->sl_seqid = xa_to_value(prev_slot);
+				slot->sl_flags |= NFSD4_SLOT_REUSED;
+			}
+			if (!xa_is_err(xa_store(&session->se_slots, s, slot,
+						GFP_NOWAIT))) {
+				s += 1;
+				session->se_fchannel.maxreqs = s;
+				atomic_add(s - session->se_target_maxslots,
+					   &nfsd_total_target_slots);
+				session->se_target_maxslots = s;
+			} else {
+				kfree(slot);
+				break;
+			}
+		}
+	}
+
+out:
+	trace_nfsd_seq4_status(rqstp, seq);
+out_no_session:
+	if (conn)
+		free_conn(conn);
+	spin_unlock(&nn->client_lock);
+	return status;
+out_put_session:
+	nfsd4_put_session_locked(session);
+	goto out_no_session;
+}
+
+void
+nfsd4_sequence_done(struct nfsd4_compoundres *resp)
+{
+	struct nfsd4_compound_state *cs = &resp->cstate;
+
+	if (nfsd4_has_session(cs)) {
+		if (cs->status != nfserr_replay_cache) {
+			nfsd4_store_cache_entry(resp);
+			cs->slot->sl_flags &= ~NFSD4_SLOT_INUSE;
+		}
+		/* Drop session reference that was taken in nfsd4_sequence() */
+		nfsd4_put_session(cs->session);
+	} else if (cs->clp)
+		put_client_renew(cs->clp);
+}
+
+__be32
+nfsd4_destroy_clientid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
+	struct nfs4_client *conf, *unconf;
+	struct nfs4_client *clp = NULL;
+	__be32 status = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	unconf = find_unconfirmed_client(&dc->clientid, true, nn);
+	conf = find_confirmed_client(&dc->clientid, true, nn);
+	WARN_ON_ONCE(conf && unconf);
+
+	if (conf) {
+		if (client_has_state(conf)) {
+			status = nfserr_clientid_busy;
+			goto out;
+		}
+		status = mark_client_expired_locked(conf);
+		if (status)
+			goto out;
+		clp = conf;
+	} else if (unconf)
+		clp = unconf;
+	else {
+		status = nfserr_stale_clientid;
+		goto out;
+	}
+	if (!nfsd4_mach_creds_match(clp, rqstp)) {
+		clp = NULL;
+		status = nfserr_wrong_cred;
+		goto out;
+	}
+	trace_nfsd_clid_destroyed(&clp->cl_clientid);
+	unhash_client_locked(clp);
+out:
+	spin_unlock(&nn->client_lock);
+	if (clp)
+		expire_client(clp);
+	return status;
+}
+
+__be32
+nfsd4_reclaim_complete(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
+	struct nfs4_client *clp = cstate->clp;
+	__be32 status = 0;
+
+	if (rc->rca_one_fs) {
+		if (!cstate->current_fh.fh_dentry)
+			return nfserr_nofilehandle;
+		/*
+		 * We don't take advantage of the rca_one_fs case.
+		 * That's OK, it's optional, we can safely ignore it.
+		 */
+		return nfs_ok;
+	}
+
+	status = nfserr_complete_already;
+	if (test_and_set_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &clp->cl_flags))
+		goto out;
+
+	status = nfserr_stale_clientid;
+	if (is_client_expired(clp))
+		/*
+		 * The following error isn't really legal.
+		 * But we only get here if the client just explicitly
+		 * destroyed the client.  Surely it no longer cares what
+		 * error it gets back on an operation for the dead
+		 * client.
+		 */
+		goto out;
+
+	status = nfs_ok;
+	trace_nfsd_clid_reclaim_complete(&clp->cl_clientid);
+	nfsd4_client_record_create(clp);
+	inc_reclaim_complete(clp);
+out:
+	return status;
+}
+
+__be32
+nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *setclid = &u->setclientid;
+	struct xdr_netobj 	clname = setclid->se_name;
+	nfs4_verifier		clverifier = setclid->se_verf;
+	struct nfs4_client	*conf, *new;
+	struct nfs4_client	*unconf = NULL;
+	__be32 			status;
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	new = create_client(clname, rqstp, &clverifier);
+	if (new == NULL)
+		return nfserr_jukebox;
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client_by_name(&clname, nn);
+	if (conf && client_has_state(conf)) {
+		status = nfserr_clid_inuse;
+		if (clp_used_exchangeid(conf))
+			goto out;
+		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
+			trace_nfsd_clid_cred_mismatch(conf, rqstp);
+			goto out;
+		}
+	}
+	unconf = find_unconfirmed_client_by_name(&clname, nn);
+	if (unconf)
+		unhash_client_locked(unconf);
+	if (conf) {
+		if (same_verf(&conf->cl_verifier, &clverifier)) {
+			copy_clid(new, conf);
+			gen_confirm(new, nn);
+		} else
+			trace_nfsd_clid_verf_mismatch(conf, rqstp,
+						      &clverifier);
+	} else
+		trace_nfsd_clid_fresh(new);
+	new->cl_minorversion = 0;
+	gen_callback(new, setclid, rqstp);
+	add_to_unconfirmed(new);
+	setclid->se_clientid.cl_boot = new->cl_clientid.cl_boot;
+	setclid->se_clientid.cl_id = new->cl_clientid.cl_id;
+	memcpy(setclid->se_confirm.data, new->cl_confirm.data, sizeof(setclid->se_confirm.data));
+	new = NULL;
+	status = nfs_ok;
+out:
+	spin_unlock(&nn->client_lock);
+	if (new)
+		free_client(new);
+	if (unconf) {
+		trace_nfsd_clid_expire_unconf(&unconf->cl_clientid);
+		expire_client(unconf);
+	}
+	return status;
+}
+
+__be32
+nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
+			struct nfsd4_compound_state *cstate,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid_confirm *setclientid_confirm =
+			&u->setclientid_confirm;
+	struct nfs4_client *conf, *unconf;
+	struct nfs4_client *old = NULL;
+	nfs4_verifier confirm = setclientid_confirm->sc_confirm; 
+	clientid_t * clid = &setclientid_confirm->sc_clientid;
+	__be32 status;
+	struct nfsd_net	*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (STALE_CLIENTID(clid, nn))
+		return nfserr_stale_clientid;
+
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client(clid, false, nn);
+	unconf = find_unconfirmed_client(clid, false, nn);
+	/*
+	 * We try hard to give out unique clientid's, so if we get an
+	 * attempt to confirm the same clientid with a different cred,
+	 * the client may be buggy; this should never happen.
+	 *
+	 * Nevertheless, RFC 7530 recommends INUSE for this case:
+	 */
+	status = nfserr_clid_inuse;
+	if (unconf && !same_creds(&unconf->cl_cred, &rqstp->rq_cred)) {
+		trace_nfsd_clid_cred_mismatch(unconf, rqstp);
+		goto out;
+	}
+	if (conf && !same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
+		trace_nfsd_clid_cred_mismatch(conf, rqstp);
+		goto out;
+	}
+	if (!unconf || !same_verf(&confirm, &unconf->cl_confirm)) {
+		if (conf && same_verf(&confirm, &conf->cl_confirm)) {
+			status = nfs_ok;
+		} else
+			status = nfserr_stale_clientid;
+		goto out;
+	}
+	status = nfs_ok;
+	if (conf) {
+		if (get_client_locked(conf) == nfs_ok) {
+			old = unconf;
+			unhash_client_locked(old);
+			nfsd4_change_callback(conf, &unconf->cl_cb_conn);
+		} else {
+			conf = NULL;
+		}
+	}
+
+	if (!conf) {
+		old = find_confirmed_client_by_name(&unconf->cl_name, nn);
+		if (old) {
+			status = nfserr_clid_inuse;
+			if (client_has_state(old)
+					&& !same_creds(&unconf->cl_cred,
+							&old->cl_cred)) {
+				old = NULL;
+				goto out;
+			}
+			status = mark_client_expired_locked(old);
+			if (status) {
+				old = NULL;
+				goto out;
+			}
+			trace_nfsd_clid_replaced(&old->cl_clientid);
+		}
+		status = get_client_locked(unconf);
+		if (status != nfs_ok) {
+			old = NULL;
+			goto out;
+		}
+		move_to_confirmed(unconf);
+		conf = unconf;
+	}
+	spin_unlock(&nn->client_lock);
+	if (conf == unconf)
+		fsnotify_dentry(conf->cl_nfsd_info_dentry, FS_MODIFY);
+	nfsd4_probe_callback(conf);
+	spin_lock(&nn->client_lock);
+	put_client_renew_locked(conf);
+out:
+	spin_unlock(&nn->client_lock);
+	if (old)
+		expire_client(old);
+	return status;
+}
+
+static struct nfs4_file *nfsd4_alloc_file(void)
+{
+	return kmem_cache_alloc(file_slab, GFP_KERNEL);
+}
+
+/* OPEN Share state helper functions */
+
+static void nfsd4_file_init(const struct svc_fh *fh, struct nfs4_file *fp)
+{
+	refcount_set(&fp->fi_ref, 1);
+	spin_lock_init(&fp->fi_lock);
+	INIT_LIST_HEAD(&fp->fi_stateids);
+	INIT_LIST_HEAD(&fp->fi_delegations);
+	INIT_LIST_HEAD(&fp->fi_clnt_odstate);
+	fh_copy_shallow(&fp->fi_fhandle, &fh->fh_handle);
+	RCU_INIT_POINTER(fp->fi_deleg_file, NULL);
+	fp->fi_rdeleg_file = NULL;
+	fp->fi_had_conflict = false;
+	fp->fi_share_deny = 0;
+	memset(fp->fi_fds, 0, sizeof(fp->fi_fds));
+	memset(fp->fi_access, 0, sizeof(fp->fi_access));
+	fp->fi_aliased = false;
+	fp->fi_inode = d_inode(fh->fh_dentry);
+#ifdef CONFIG_NFSD_PNFS
+	INIT_LIST_HEAD(&fp->fi_lo_states);
+	atomic_set(&fp->fi_lo_recalls, 0);
+#endif
+}
+
+void
+nfsd4_free_slabs(void)
+{
+	kmem_cache_destroy(client_slab);
+	kmem_cache_destroy(openowner_slab);
+	kmem_cache_destroy(lockowner_slab);
+	kmem_cache_destroy(file_slab);
+	kmem_cache_destroy(stateid_slab);
+	kmem_cache_destroy(deleg_slab);
+	kmem_cache_destroy(odstate_slab);
+	kmem_cache_destroy(async_copy_slab);
+}
+
+int
+nfsd4_init_slabs(void)
+{
+	client_slab = KMEM_CACHE(nfs4_client, 0);
+	if (client_slab == NULL)
+		goto out;
+	openowner_slab = KMEM_CACHE(nfs4_openowner, 0);
+	if (openowner_slab == NULL)
+		goto out_free_client_slab;
+	lockowner_slab = KMEM_CACHE(nfs4_lockowner, 0);
+	if (lockowner_slab == NULL)
+		goto out_free_openowner_slab;
+	file_slab = KMEM_CACHE(nfs4_file, 0);
+	if (file_slab == NULL)
+		goto out_free_lockowner_slab;
+	stateid_slab = KMEM_CACHE(nfs4_ol_stateid, 0);
+	if (stateid_slab == NULL)
+		goto out_free_file_slab;
+	deleg_slab = KMEM_CACHE(nfs4_delegation, 0);
+	if (deleg_slab == NULL)
+		goto out_free_stateid_slab;
+	odstate_slab = KMEM_CACHE(nfs4_clnt_odstate, 0);
+	if (odstate_slab == NULL)
+		goto out_free_deleg_slab;
+	async_copy_slab = KMEM_CACHE(nfsd4_async_copy, 0);
+	if (async_copy_slab == NULL)
+		goto out_free_odstate_slab;
+	return 0;
+
+out_free_odstate_slab:
+	kmem_cache_destroy(odstate_slab);
+out_free_deleg_slab:
+	kmem_cache_destroy(deleg_slab);
+out_free_stateid_slab:
+	kmem_cache_destroy(stateid_slab);
+out_free_file_slab:
+	kmem_cache_destroy(file_slab);
+out_free_lockowner_slab:
+	kmem_cache_destroy(lockowner_slab);
+out_free_openowner_slab:
+	kmem_cache_destroy(openowner_slab);
+out_free_client_slab:
+	kmem_cache_destroy(client_slab);
+out:
+	return -ENOMEM;
+}
+
+static unsigned long
+nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct nfsd_net *nn = shrink->private_data;
+	long count;
+
+	count = atomic_read(&nn->nfsd_courtesy_clients);
+	if (!count)
+		count = atomic_long_read(&num_delegations);
+	if (count)
+		queue_work(laundry_wq, &nn->nfsd_shrinker_work);
+	return (unsigned long)count;
+}
+
+static unsigned long
+nfsd4_state_shrinker_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	return SHRINK_STOP;
+}
+
+void
+nfsd4_init_leases_net(struct nfsd_net *nn)
+{
+	struct sysinfo si;
+	u64 max_clients;
+
+	nn->nfsd4_lease = 90;	/* default lease time */
+	nn->nfsd4_grace = 90;
+	nn->clverifier_counter = get_random_u32();
+	nn->clientid_base = get_random_u32();
+	nn->clientid_counter = nn->clientid_base + 1;
+	nn->s2s_cp_cl_id = nn->clientid_counter++;
+
+	atomic_set(&nn->nfs4_client_count, 0);
+	si_meminfo(&si);
+	max_clients = (u64)si.totalram * si.mem_unit / (1024 * 1024 * 1024);
+	max_clients *= NFS4_CLIENTS_PER_GB;
+	nn->nfs4_max_clients = max_t(int, max_clients, NFS4_CLIENTS_PER_GB);
+
+	atomic_set(&nn->nfsd_courtesy_clients, 0);
+}
+
+enum rp_lock {
+	RP_UNLOCKED,
+	RP_LOCKED,
+	RP_UNHASHED,
+};
+
+static void init_nfs4_replay(struct nfs4_replay *rp)
+{
+	rp->rp_status = nfserr_serverfault;
+	rp->rp_buflen = 0;
+	rp->rp_buf = rp->rp_ibuf;
+	rp->rp_locked = RP_UNLOCKED;
+}
+
+static int nfsd4_cstate_assign_replay(struct nfsd4_compound_state *cstate,
+				      struct nfs4_stateowner *so)
+{
+	if (!nfsd4_has_session(cstate)) {
+		wait_var_event(&so->so_replay.rp_locked,
+			       cmpxchg(&so->so_replay.rp_locked,
+				       RP_UNLOCKED, RP_LOCKED) != RP_LOCKED);
+		if (so->so_replay.rp_locked == RP_UNHASHED)
+			return -EAGAIN;
+		cstate->replay_owner = nfs4_get_stateowner(so);
+	}
+	return 0;
+}
+
+void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate)
+{
+	struct nfs4_stateowner *so = cstate->replay_owner;
+
+	if (so != NULL) {
+		cstate->replay_owner = NULL;
+		store_release_wake_up(&so->so_replay.rp_locked, RP_UNLOCKED);
+		nfs4_put_stateowner(so);
+	}
+}
+
+static inline void *alloc_stateowner(struct kmem_cache *slab, struct xdr_netobj *owner, struct nfs4_client *clp)
+{
+	struct nfs4_stateowner *sop;
+
+	sop = kmem_cache_alloc(slab, GFP_KERNEL);
+	if (!sop)
+		return NULL;
+
+	xdr_netobj_dup(&sop->so_owner, owner, GFP_KERNEL);
+	if (!sop->so_owner.data) {
+		kmem_cache_free(slab, sop);
+		return NULL;
+	}
+
+	INIT_LIST_HEAD(&sop->so_stateids);
+	sop->so_client = clp;
+	init_nfs4_replay(&sop->so_replay);
+	atomic_set(&sop->so_count, 1);
+	return sop;
+}
+
+static void hash_openowner(struct nfs4_openowner *oo, struct nfs4_client *clp, unsigned int strhashval)
+{
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_add(&oo->oo_owner.so_strhash,
+		 &clp->cl_ownerstr_hashtbl[strhashval]);
+	list_add(&oo->oo_perclient, &clp->cl_openowners);
+}
+
+static void nfs4_unhash_openowner(struct nfs4_stateowner *so)
+{
+	unhash_openowner_locked(openowner(so));
+}
+
+static void nfs4_free_openowner(struct nfs4_stateowner *so)
+{
+	struct nfs4_openowner *oo = openowner(so);
+
+	kmem_cache_free(openowner_slab, oo);
+}
+
+static const struct nfs4_stateowner_operations openowner_ops = {
+	.so_unhash =	nfs4_unhash_openowner,
+	.so_free =	nfs4_free_openowner,
+};
+
+static struct nfs4_ol_stateid *
+nfsd4_find_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+	struct nfs4_ol_stateid *local, *ret = NULL;
+	struct nfs4_openowner *oo = open->op_openowner;
+
+	lockdep_assert_held(&fp->fi_lock);
+
+	list_for_each_entry(local, &fp->fi_stateids, st_perfile) {
+		/* ignore lock owners */
+		if (local->st_stateowner->so_is_open_owner == 0)
+			continue;
+		if (local->st_stateowner != &oo->oo_owner)
+			continue;
+		if (local->st_stid.sc_type == SC_TYPE_OPEN &&
+		    !local->st_stid.sc_status) {
+			ret = local;
+			refcount_inc(&ret->st_stid.sc_count);
+			break;
+		}
+	}
+	return ret;
+}
+
+static void nfsd4_drop_revoked_stid(struct nfs4_stid *s)
+	__releases(&s->sc_client->cl_lock)
+{
+	struct nfs4_client *cl = s->sc_client;
+	LIST_HEAD(reaplist);
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_delegation *dp;
+	bool unhashed;
+
+	switch (s->sc_type) {
+	case SC_TYPE_OPEN:
+		stp = openlockstateid(s);
+		if (unhash_open_stateid(stp, &reaplist))
+			put_ol_stateid_locked(stp, &reaplist);
+		spin_unlock(&cl->cl_lock);
+		free_ol_stateid_reaplist(&reaplist);
+		break;
+	case SC_TYPE_LOCK:
+		stp = openlockstateid(s);
+		unhashed = unhash_lock_stateid(stp);
+		spin_unlock(&cl->cl_lock);
+		if (unhashed)
+			nfs4_put_stid(s);
+		break;
+	case SC_TYPE_DELEG:
+		dp = delegstateid(s);
+		list_del_init(&dp->dl_recall_lru);
+		s->sc_status |= SC_STATUS_FREED;
+		spin_unlock(&cl->cl_lock);
+		nfs4_put_stid(s);
+		break;
+	case SC_TYPE_LAYOUT:
+		ls = layoutstateid(s);
+		list_del_init(&ls->ls_perclnt);
+		spin_unlock(&cl->cl_lock);
+		nfs4_put_stid(s);
+		break;
+	default:
+		spin_unlock(&cl->cl_lock);
+	}
+}
+
+static void nfsd40_drop_revoked_stid(struct nfs4_client *cl,
+				    stateid_t *stid)
+{
+	/* NFSv4.0 has no way for the client to tell the server
+	 * that it can forget an admin-revoked stateid.
+	 * So we keep it around until the first time that the
+	 * client uses it, and drop it the first time
+	 * nfserr_admin_revoked is returned.
+	 * For v4.1 and later we wait until explicitly told
+	 * to free the stateid.
+	 */
+	if (cl->cl_minorversion == 0) {
+		struct nfs4_stid *st;
+
+		spin_lock(&cl->cl_lock);
+		st = find_stateid_locked(cl, stid);
+		if (st)
+			nfsd4_drop_revoked_stid(st);
+		else
+			spin_unlock(&cl->cl_lock);
+	}
+}
+
+static __be32
+nfsd4_verify_open_stid(struct nfs4_stid *s)
+{
+	__be32 ret = nfs_ok;
+
+	if (s->sc_status & SC_STATUS_ADMIN_REVOKED)
+		ret = nfserr_admin_revoked;
+	else if (s->sc_status & SC_STATUS_REVOKED)
+		ret = nfserr_deleg_revoked;
+	else if (s->sc_status & SC_STATUS_CLOSED)
+		ret = nfserr_bad_stateid;
+	return ret;
+}
+
+/* Lock the stateid st_mutex, and deal with races with CLOSE */
+static __be32
+nfsd4_lock_ol_stateid(struct nfs4_ol_stateid *stp)
+{
+	__be32 ret;
+
+	mutex_lock_nested(&stp->st_mutex, LOCK_STATEID_MUTEX);
+	ret = nfsd4_verify_open_stid(&stp->st_stid);
+	if (ret == nfserr_admin_revoked)
+		nfsd40_drop_revoked_stid(stp->st_stid.sc_client,
+					&stp->st_stid.sc_stateid);
+
+	if (ret != nfs_ok)
+		mutex_unlock(&stp->st_mutex);
+	return ret;
+}
+
+static struct nfs4_ol_stateid *
+nfsd4_find_and_lock_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+	struct nfs4_ol_stateid *stp;
+	for (;;) {
+		spin_lock(&fp->fi_lock);
+		stp = nfsd4_find_existing_open(fp, open);
+		spin_unlock(&fp->fi_lock);
+		if (!stp || nfsd4_lock_ol_stateid(stp) == nfs_ok)
+			break;
+		nfs4_put_stid(&stp->st_stid);
+	}
+	return stp;
+}
+
+static struct nfs4_openowner *
+find_or_alloc_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
+			      struct nfsd4_compound_state *cstate)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_openowner *oo, *new = NULL;
+
+retry:
+	spin_lock(&clp->cl_lock);
+	oo = find_openstateowner_str(strhashval, open, clp);
+	if (!oo && new) {
+		hash_openowner(new, clp, strhashval);
+		spin_unlock(&clp->cl_lock);
+		return new;
+	}
+	spin_unlock(&clp->cl_lock);
+
+	if (oo && !(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+		/* Replace unconfirmed owners without checking for replay. */
+		release_openowner(oo);
+		oo = NULL;
+		goto retry;
+	}
+	if (oo) {
+		if (new)
+			nfs4_free_stateowner(&new->oo_owner);
+		return oo;
+	}
+
+	new = alloc_stateowner(openowner_slab, &open->op_owner, clp);
+	if (!new)
+		return NULL;
+	new->oo_owner.so_ops = &openowner_ops;
+	new->oo_owner.so_is_open_owner = 1;
+	new->oo_owner.so_seqid = open->op_seqid;
+	new->oo_flags = 0;
+	if (nfsd4_has_session(cstate))
+		new->oo_flags |= NFS4_OO_CONFIRMED;
+	new->oo_time = 0;
+	new->oo_last_closed_stid = NULL;
+	INIT_LIST_HEAD(&new->oo_close_lru);
+	goto retry;
+}
+
+static struct nfs4_ol_stateid *
+init_open_stateid(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+
+	struct nfs4_openowner *oo = open->op_openowner;
+	struct nfs4_ol_stateid *retstp = NULL;
+	struct nfs4_ol_stateid *stp;
+
+	stp = open->op_stp;
+	/* We are moving these outside of the spinlocks to avoid the warnings */
+	mutex_init(&stp->st_mutex);
+	mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX);
+
+retry:
+	spin_lock(&oo->oo_owner.so_client->cl_lock);
+	spin_lock(&fp->fi_lock);
+
+	if (nfs4_openowner_unhashed(oo)) {
+		mutex_unlock(&stp->st_mutex);
+		stp = NULL;
+		goto out_unlock;
+	}
+
+	retstp = nfsd4_find_existing_open(fp, open);
+	if (retstp)
+		goto out_unlock;
+
+	open->op_stp = NULL;
+	refcount_inc(&stp->st_stid.sc_count);
+	stp->st_stid.sc_type = SC_TYPE_OPEN;
+	INIT_LIST_HEAD(&stp->st_locks);
+	stp->st_stateowner = nfs4_get_stateowner(&oo->oo_owner);
+	get_nfs4_file(fp);
+	stp->st_stid.sc_file = fp;
+	stp->st_access_bmap = 0;
+	stp->st_deny_bmap = 0;
+	stp->st_openstp = NULL;
+	list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids);
+	list_add(&stp->st_perfile, &fp->fi_stateids);
+
+out_unlock:
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&oo->oo_owner.so_client->cl_lock);
+	if (retstp) {
+		/* Handle races with CLOSE */
+		if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) {
+			nfs4_put_stid(&retstp->st_stid);
+			goto retry;
+		}
+		/* To keep mutex tracking happy */
+		mutex_unlock(&stp->st_mutex);
+		stp = retstp;
+	}
+	return stp;
+}
+
+/*
+ * In the 4.0 case we need to keep the owners around a little while to handle
+ * CLOSE replay. We still do need to release any file access that is held by
+ * them before returning however.
+ */
+static void
+move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
+{
+	struct nfs4_ol_stateid *last;
+	struct nfs4_openowner *oo = openowner(s->st_stateowner);
+	struct nfsd_net *nn = net_generic(s->st_stid.sc_client->net,
+						nfsd_net_id);
+
+	dprintk("NFSD: move_to_close_lru nfs4_openowner %p\n", oo);
+
+	/*
+	 * We know that we hold one reference via nfsd4_close, and another
+	 * "persistent" reference for the client. If the refcount is higher
+	 * than 2, then there are still calls in progress that are using this
+	 * stateid. We can't put the sc_file reference until they are finished.
+	 * Wait for the refcount to drop to 2. Since it has been unhashed,
+	 * there should be no danger of the refcount going back up again at
+	 * this point.
+	 * Some threads with a reference might be waiting for rp_locked,
+	 * so tell them to stop waiting.
+	 */
+	store_release_wake_up(&oo->oo_owner.so_replay.rp_locked, RP_UNHASHED);
+	wait_event(close_wq, refcount_read(&s->st_stid.sc_count) == 2);
+
+	release_all_access(s);
+	if (s->st_stid.sc_file) {
+		put_nfs4_file(s->st_stid.sc_file);
+		s->st_stid.sc_file = NULL;
+	}
+
+	spin_lock(&nn->client_lock);
+	last = oo->oo_last_closed_stid;
+	oo->oo_last_closed_stid = s;
+	list_move_tail(&oo->oo_close_lru, &nn->close_lru);
+	oo->oo_time = ktime_get_boottime_seconds();
+	spin_unlock(&nn->client_lock);
+	if (last)
+		nfs4_put_stid(&last->st_stid);
+}
+
+static noinline_for_stack struct nfs4_file *
+nfsd4_file_hash_lookup(const struct svc_fh *fhp)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+	struct rhlist_head *tmp, *list;
+	struct nfs4_file *fi;
+
+	rcu_read_lock();
+	list = rhltable_lookup(&nfs4_file_rhltable, &inode,
+			       nfs4_file_rhash_params);
+	rhl_for_each_entry_rcu(fi, tmp, list, fi_rlist) {
+		if (fh_match(&fi->fi_fhandle, &fhp->fh_handle)) {
+			if (refcount_inc_not_zero(&fi->fi_ref)) {
+				rcu_read_unlock();
+				return fi;
+			}
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
+}
+
+/*
+ * On hash insertion, identify entries with the same inode but
+ * distinct filehandles. They will all be on the list returned
+ * by rhltable_lookup().
+ *
+ * inode->i_lock prevents racing insertions from adding an entry
+ * for the same inode/fhp pair twice.
+ */
+static noinline_for_stack struct nfs4_file *
+nfsd4_file_hash_insert(struct nfs4_file *new, const struct svc_fh *fhp)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+	struct rhlist_head *tmp, *list;
+	struct nfs4_file *ret = NULL;
+	bool alias_found = false;
+	struct nfs4_file *fi;
+	int err;
+
+	rcu_read_lock();
+	spin_lock(&inode->i_lock);
+
+	list = rhltable_lookup(&nfs4_file_rhltable, &inode,
+			       nfs4_file_rhash_params);
+	rhl_for_each_entry_rcu(fi, tmp, list, fi_rlist) {
+		if (fh_match(&fi->fi_fhandle, &fhp->fh_handle)) {
+			if (refcount_inc_not_zero(&fi->fi_ref))
+				ret = fi;
+		} else
+			fi->fi_aliased = alias_found = true;
+	}
+	if (ret)
+		goto out_unlock;
+
+	nfsd4_file_init(fhp, new);
+	err = rhltable_insert(&nfs4_file_rhltable, &new->fi_rlist,
+			      nfs4_file_rhash_params);
+	if (err)
+		goto out_unlock;
+
+	new->fi_aliased = alias_found;
+	ret = new;
+
+out_unlock:
+	spin_unlock(&inode->i_lock);
+	rcu_read_unlock();
+	return ret;
+}
+
+static noinline_for_stack void nfsd4_file_hash_remove(struct nfs4_file *fi)
+{
+	rhltable_remove(&nfs4_file_rhltable, &fi->fi_rlist,
+			nfs4_file_rhash_params);
+}
+
+/*
+ * Called to check deny when READ with all zero stateid or
+ * WRITE with all zero or all one stateid
+ */
+static __be32
+nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
+{
+	struct nfs4_file *fp;
+	__be32 ret = nfs_ok;
+
+	fp = nfsd4_file_hash_lookup(current_fh);
+	if (!fp)
+		return ret;
+
+	/* Check for conflicting share reservations */
+	spin_lock(&fp->fi_lock);
+	if (fp->fi_share_deny & deny_type)
+		ret = nfserr_locked;
+	spin_unlock(&fp->fi_lock);
+	put_nfs4_file(fp);
+	return ret;
+}
+
+static bool nfsd4_deleg_present(const struct inode *inode)
+{
+	struct file_lock_context *ctx = locks_inode_context(inode);
+
+	return ctx && !list_empty_careful(&ctx->flc_lease);
+}
+
+/**
+ * nfsd_wait_for_delegreturn - wait for delegations to be returned
+ * @rqstp: the RPC transaction being executed
+ * @inode: in-core inode of the file being waited for
+ *
+ * The timeout prevents deadlock if all nfsd threads happen to be
+ * tied up waiting for returning delegations.
+ *
+ * Return values:
+ *   %true: delegation was returned
+ *   %false: timed out waiting for delegreturn
+ */
+bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp, struct inode *inode)
+{
+	long __maybe_unused timeo;
+
+	timeo = wait_var_event_timeout(inode, !nfsd4_deleg_present(inode),
+				       NFSD_DELEGRETURN_TIMEOUT);
+	trace_nfsd_delegret_wakeup(rqstp, inode, timeo);
+	return timeo > 0;
+}
+
+static bool nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+	struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
+					  nfsd_net_id);
+
+	block_delegations(&dp->dl_stid.sc_file->fi_fhandle);
+
+	/*
+	 * We can't do this in nfsd_break_deleg_cb because it is
+	 * already holding inode->i_lock.
+	 *
+	 * If the dl_time != 0, then we know that it has already been
+	 * queued for a lease break. Don't queue it again.
+	 */
+	spin_lock(&nn->deleg_lock);
+	if (delegation_hashed(dp) && dp->dl_time == 0) {
+		dp->dl_time = ktime_get_boottime_seconds();
+		list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru);
+	}
+	spin_unlock(&nn->deleg_lock);
+	return true;
+}
+
+static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
+		struct rpc_task *task)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+	trace_nfsd_cb_recall_done(&dp->dl_stid.sc_stateid, task);
+
+	if (dp->dl_stid.sc_status)
+		/* CLOSED or REVOKED */
+		return 1;
+
+	switch (task->tk_status) {
+	case 0:
+		return 1;
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	case -EBADHANDLE:
+	case -NFS4ERR_BAD_STATEID:
+		/*
+		 * Race: client probably got cb_recall before open reply
+		 * granting delegation.
+		 */
+		if (dp->dl_retries--) {
+			rpc_delay(task, 2 * HZ);
+			return 0;
+		}
+		fallthrough;
+	default:
+		return 1;
+	}
+}
+
+static void nfsd4_cb_recall_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_ops = {
+	.prepare	= nfsd4_cb_recall_prepare,
+	.done		= nfsd4_cb_recall_done,
+	.release	= nfsd4_cb_recall_release,
+	.opcode		= OP_CB_RECALL,
+};
+
+/* Called from break_lease() with flc_lock held. */
+static bool
+nfsd_break_deleg_cb(struct file_lease *fl)
+{
+	struct nfs4_delegation *dp = (struct nfs4_delegation *) fl->c.flc_owner;
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	struct nfsd_net *nn;
+
+	trace_nfsd_cb_recall(&dp->dl_stid);
+
+	dp->dl_recalled = true;
+	atomic_inc(&clp->cl_delegs_in_recall);
+	if (try_to_expire_client(clp)) {
+		nn = net_generic(clp->net, nfsd_net_id);
+		mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+	}
+
+	/*
+	 * We don't want the locks code to timeout the lease for us;
+	 * we'll remove it ourself if a delegation isn't returned
+	 * in time:
+	 */
+	fl->fl_break_time = 0;
+
+	fp->fi_had_conflict = true;
+	nfsd_break_one_deleg(dp);
+	return false;
+}
+
+/**
+ * nfsd_breaker_owns_lease - Check if lease conflict was resolved
+ * @fl: Lock state to check
+ *
+ * Return values:
+ *   %true: Lease conflict was resolved
+ *   %false: Lease conflict was not resolved.
+ */
+static bool nfsd_breaker_owns_lease(struct file_lease *fl)
+{
+	struct nfs4_delegation *dl = fl->c.flc_owner;
+	struct nfsd_thread_local_info *ntli;
+	struct svc_rqst *rqst;
+	struct nfs4_client *clp;
+
+	/* Only nfsd leases */
+	if (fl->fl_lmops != &nfsd_lease_mng_ops)
+		return false;
+
+	rqst = nfsd_current_rqst();
+	if (!nfsd_v4client(rqst))
+		return false;
+	ntli = rqst->rq_private;
+	clp = *ntli->ntli_lease_breaker;
+	return dl->dl_stid.sc_client == clp;
+}
+
+static int
+nfsd_change_deleg_cb(struct file_lease *onlist, int arg,
+		     struct list_head *dispose)
+{
+	struct nfs4_delegation *dp = (struct nfs4_delegation *) onlist->c.flc_owner;
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+
+	if (arg & F_UNLCK) {
+		if (dp->dl_recalled)
+			atomic_dec(&clp->cl_delegs_in_recall);
+		return lease_modify(onlist, arg, dispose);
+	} else
+		return -EAGAIN;
+}
+
+/**
+ *  nfsd4_deleg_lm_open_conflict - see if the given file points to an inode that has
+ *				   an existing open that would conflict with the
+ *				   desired lease.
+ * @filp:	file to check
+ * @arg:	type of lease that we're trying to acquire
+ *
+ * The kernel will call into this operation to determine whether there
+ * are conflicting opens that may prevent the deleg from being granted.
+ * For nfsd, that check is done at a higher level, so this trivially
+ * returns 0.
+ */
+static int
+nfsd4_deleg_lm_open_conflict(struct file *filp, int arg)
+{
+	return 0;
+}
+
+static const struct lease_manager_operations nfsd_lease_mng_ops = {
+	.lm_breaker_owns_lease = nfsd_breaker_owns_lease,
+	.lm_break = nfsd_break_deleg_cb,
+	.lm_change = nfsd_change_deleg_cb,
+	.lm_open_conflict = nfsd4_deleg_lm_open_conflict,
+};
+
+static __be32 nfsd4_check_seqid(struct nfsd4_compound_state *cstate, struct nfs4_stateowner *so, u32 seqid)
+{
+	if (nfsd4_has_session(cstate))
+		return nfs_ok;
+	if (seqid == so->so_seqid - 1)
+		return nfserr_replay_me;
+	if (seqid == so->so_seqid)
+		return nfs_ok;
+	return nfserr_bad_seqid;
+}
+
+static struct nfs4_client *lookup_clientid(clientid_t *clid, bool sessions,
+						struct nfsd_net *nn)
+{
+	struct nfs4_client *found;
+
+	spin_lock(&nn->client_lock);
+	found = find_confirmed_client(clid, sessions, nn);
+	if (found)
+		atomic_inc(&found->cl_rpc_users);
+	spin_unlock(&nn->client_lock);
+	return found;
+}
+
+static __be32 set_client(clientid_t *clid,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd_net *nn)
+{
+	if (cstate->clp) {
+		if (!same_clid(&cstate->clp->cl_clientid, clid))
+			return nfserr_stale_clientid;
+		return nfs_ok;
+	}
+	if (STALE_CLIENTID(clid, nn))
+		return nfserr_stale_clientid;
+	/*
+	 * We're in the 4.0 case (otherwise the SEQUENCE op would have
+	 * set cstate->clp), so session = false:
+	 */
+	cstate->clp = lookup_clientid(clid, false, nn);
+	if (!cstate->clp)
+		return nfserr_expired;
+	return nfs_ok;
+}
+
+__be32
+nfsd4_process_open1(struct nfsd4_compound_state *cstate,
+		    struct nfsd4_open *open, struct nfsd_net *nn)
+{
+	clientid_t *clientid = &open->op_clientid;
+	struct nfs4_client *clp = NULL;
+	unsigned int strhashval;
+	struct nfs4_openowner *oo = NULL;
+	__be32 status;
+
+	/*
+	 * In case we need it later, after we've already created the
+	 * file and don't want to risk a further failure:
+	 */
+	open->op_file = nfsd4_alloc_file();
+	if (open->op_file == NULL)
+		return nfserr_jukebox;
+
+	status = set_client(clientid, cstate, nn);
+	if (status)
+		return status;
+	clp = cstate->clp;
+
+	strhashval = ownerstr_hashval(&open->op_owner);
+retry:
+	oo = find_or_alloc_open_stateowner(strhashval, open, cstate);
+	open->op_openowner = oo;
+	if (!oo)
+		return nfserr_jukebox;
+	if (nfsd4_cstate_assign_replay(cstate, &oo->oo_owner) == -EAGAIN) {
+		nfs4_put_stateowner(&oo->oo_owner);
+		goto retry;
+	}
+	status = nfsd4_check_seqid(cstate, &oo->oo_owner, open->op_seqid);
+	if (status)
+		return status;
+
+	open->op_stp = nfs4_alloc_open_stateid(clp);
+	if (!open->op_stp)
+		return nfserr_jukebox;
+
+	if (nfsd4_has_session(cstate) &&
+	    (cstate->current_fh.fh_export->ex_flags & NFSEXP_PNFS)) {
+		open->op_odstate = alloc_clnt_odstate(clp);
+		if (!open->op_odstate)
+			return nfserr_jukebox;
+	}
+
+	return nfs_ok;
+}
+
+static inline __be32
+nfs4_check_delegmode(struct nfs4_delegation *dp, int flags)
+{
+	if (!(flags & RD_STATE) && deleg_is_read(dp->dl_type))
+		return nfserr_openmode;
+	else
+		return nfs_ok;
+}
+
+static int share_access_to_flags(u32 share_access)
+{
+	return share_access == NFS4_SHARE_ACCESS_READ ? RD_STATE : WR_STATE;
+}
+
+static struct nfs4_delegation *find_deleg_stateid(struct nfs4_client *cl,
+						  stateid_t *s)
+{
+	struct nfs4_stid *ret;
+
+	ret = find_stateid_by_type(cl, s, SC_TYPE_DELEG, SC_STATUS_REVOKED);
+	if (!ret)
+		return NULL;
+	return delegstateid(ret);
+}
+
+static bool nfsd4_is_deleg_cur(struct nfsd4_open *open)
+{
+	return open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR ||
+	       open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH;
+}
+
+static __be32
+nfs4_check_deleg(struct nfs4_client *cl, struct nfsd4_open *open,
+		struct nfs4_delegation **dp)
+{
+	int flags;
+	__be32 status = nfserr_bad_stateid;
+	struct nfs4_delegation *deleg;
+
+	deleg = find_deleg_stateid(cl, &open->op_delegate_stateid);
+	if (deleg == NULL)
+		goto out;
+	if (deleg->dl_stid.sc_status & SC_STATUS_ADMIN_REVOKED) {
+		nfs4_put_stid(&deleg->dl_stid);
+		status = nfserr_admin_revoked;
+		goto out;
+	}
+	if (deleg->dl_stid.sc_status & SC_STATUS_REVOKED) {
+		nfs4_put_stid(&deleg->dl_stid);
+		nfsd40_drop_revoked_stid(cl, &open->op_delegate_stateid);
+		status = nfserr_deleg_revoked;
+		goto out;
+	}
+	flags = share_access_to_flags(open->op_share_access);
+	status = nfs4_check_delegmode(deleg, flags);
+	if (status) {
+		nfs4_put_stid(&deleg->dl_stid);
+		goto out;
+	}
+	*dp = deleg;
+out:
+	if (!nfsd4_is_deleg_cur(open))
+		return nfs_ok;
+	if (status)
+		return status;
+	open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+	return nfs_ok;
+}
+
+static inline int nfs4_access_to_access(u32 nfs4_access)
+{
+	int flags = 0;
+
+	if (nfs4_access & NFS4_SHARE_ACCESS_READ)
+		flags |= NFSD_MAY_READ;
+	if (nfs4_access & NFS4_SHARE_ACCESS_WRITE)
+		flags |= NFSD_MAY_WRITE;
+	return flags;
+}
+
+static inline __be32
+nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
+		struct nfsd4_open *open)
+{
+	struct iattr iattr = {
+		.ia_valid = ATTR_SIZE,
+		.ia_size = 0,
+	};
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &iattr,
+	};
+	if (!open->op_truncate)
+		return 0;
+	if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
+		return nfserr_inval;
+	return nfsd_setattr(rqstp, fh, &attrs, NULL);
+}
+
+static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
+		struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
+		struct nfsd4_open *open, bool new_stp)
+{
+	struct nfsd_file *nf = NULL;
+	__be32 status;
+	int oflag = nfs4_access_to_omode(open->op_share_access);
+	int access = nfs4_access_to_access(open->op_share_access);
+	unsigned char old_access_bmap, old_deny_bmap;
+
+	spin_lock(&fp->fi_lock);
+
+	/*
+	 * Are we trying to set a deny mode that would conflict with
+	 * current access?
+	 */
+	status = nfs4_file_check_deny(fp, open->op_share_deny);
+	if (status != nfs_ok) {
+		if (status != nfserr_share_denied) {
+			spin_unlock(&fp->fi_lock);
+			goto out;
+		}
+		if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
+				stp, open->op_share_deny, false))
+			status = nfserr_jukebox;
+		spin_unlock(&fp->fi_lock);
+		goto out;
+	}
+
+	/* set access to the file */
+	status = nfs4_file_get_access(fp, open->op_share_access);
+	if (status != nfs_ok) {
+		if (status != nfserr_share_denied) {
+			spin_unlock(&fp->fi_lock);
+			goto out;
+		}
+		if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,
+				stp, open->op_share_access, true))
+			status = nfserr_jukebox;
+		spin_unlock(&fp->fi_lock);
+		goto out;
+	}
+
+	/* Set access bits in stateid */
+	old_access_bmap = stp->st_access_bmap;
+	set_access(open->op_share_access, stp);
+
+	/* Set new deny mask */
+	old_deny_bmap = stp->st_deny_bmap;
+	set_deny(open->op_share_deny, stp);
+	fp->fi_share_deny |= (open->op_share_deny & NFS4_SHARE_DENY_BOTH);
+
+	if (!fp->fi_fds[oflag]) {
+		spin_unlock(&fp->fi_lock);
+
+		status = nfsd_file_acquire_opened(rqstp, cur_fh, access,
+						  open->op_filp, &nf);
+		if (status != nfs_ok)
+			goto out_put_access;
+
+		spin_lock(&fp->fi_lock);
+		if (!fp->fi_fds[oflag]) {
+			fp->fi_fds[oflag] = nf;
+			nf = NULL;
+		}
+	}
+	spin_unlock(&fp->fi_lock);
+	if (nf)
+		nfsd_file_put(nf);
+
+	status = nfserrno(nfsd_open_break_lease(cur_fh->fh_dentry->d_inode,
+								access));
+	if (status)
+		goto out_put_access;
+
+	status = nfsd4_truncate(rqstp, cur_fh, open);
+	if (status)
+		goto out_put_access;
+out:
+	return status;
+out_put_access:
+	stp->st_access_bmap = old_access_bmap;
+	nfs4_file_put_access(fp, open->op_share_access);
+	reset_union_bmap_deny(bmap_to_share_mode(old_deny_bmap), stp);
+	goto out;
+}
+
+static __be32
+nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp,
+		struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
+		struct nfsd4_open *open)
+{
+	__be32 status;
+	unsigned char old_deny_bmap = stp->st_deny_bmap;
+
+	if (!test_access(open->op_share_access, stp))
+		return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open, false);
+
+	/* test and set deny mode */
+	spin_lock(&fp->fi_lock);
+	status = nfs4_file_check_deny(fp, open->op_share_deny);
+	switch (status) {
+	case nfs_ok:
+		set_deny(open->op_share_deny, stp);
+		fp->fi_share_deny |=
+			(open->op_share_deny & NFS4_SHARE_DENY_BOTH);
+		break;
+	case nfserr_share_denied:
+		if (nfs4_resolve_deny_conflicts_locked(fp, false,
+				stp, open->op_share_deny, false))
+			status = nfserr_jukebox;
+		break;
+	}
+	spin_unlock(&fp->fi_lock);
+
+	if (status != nfs_ok)
+		return status;
+
+	status = nfsd4_truncate(rqstp, cur_fh, open);
+	if (status != nfs_ok)
+		reset_union_bmap_deny(old_deny_bmap, stp);
+	return status;
+}
+
+/* Should we give out recallable state?: */
+static bool nfsd4_cb_channel_good(struct nfs4_client *clp)
+{
+	if (clp->cl_cb_state == NFSD4_CB_UP)
+		return true;
+	/*
+	 * In the sessions case, since we don't have to establish a
+	 * separate connection for callbacks, we assume it's OK
+	 * until we hear otherwise:
+	 */
+	return clp->cl_minorversion && clp->cl_cb_state == NFSD4_CB_UNKNOWN;
+}
+
+static unsigned int
+nfsd_notify_to_ignore(u32 notify)
+{
+	unsigned int mask = 0;
+
+	if (notify & BIT(NOTIFY4_REMOVE_ENTRY))
+		mask |= FL_IGN_DIR_DELETE;
+	if (notify & BIT(NOTIFY4_ADD_ENTRY))
+		mask |= FL_IGN_DIR_CREATE;
+	if (notify & BIT(NOTIFY4_RENAME_ENTRY))
+		mask |= FL_IGN_DIR_RENAME;
+
+	return mask;
+}
+
+static struct file_lease *nfs4_alloc_init_lease(struct nfs4_delegation *dp, u32 notify)
+{
+	struct file_lease *fl;
+
+	fl = locks_alloc_lease();
+	if (!fl)
+		return NULL;
+	fl->fl_lmops = &nfsd_lease_mng_ops;
+	fl->c.flc_flags = FL_DELEG | nfsd_notify_to_ignore(notify);
+	fl->c.flc_type = deleg_is_read(dp->dl_type) ? F_RDLCK : F_WRLCK;
+	fl->c.flc_owner = (fl_owner_t)dp;
+	fl->c.flc_pid = current->tgid;
+	fl->c.flc_file = rcu_dereference_protected(dp->dl_stid.sc_file->fi_deleg_file, 1)->nf_file;
+	return fl;
+}
+
+static int nfsd4_check_conflicting_opens(struct nfs4_client *clp,
+					 struct nfs4_file *fp)
+{
+	struct nfs4_ol_stateid *st;
+	struct file *f = rcu_dereference_protected(fp->fi_deleg_file, 1)->nf_file;
+	struct inode *ino = file_inode(f);
+	int writes;
+
+	writes = atomic_read(&ino->i_writecount);
+	if (!writes)
+		return 0;
+	/*
+	 * There could be multiple filehandles (hence multiple
+	 * nfs4_files) referencing this file, but that's not too
+	 * common; let's just give up in that case rather than
+	 * trying to go look up all the clients using that other
+	 * nfs4_file as well:
+	 */
+	if (fp->fi_aliased)
+		return -EAGAIN;
+	/*
+	 * If there's a close in progress, make sure that we see it
+	 * clear any fi_fds[] entries before we see it decrement
+	 * i_writecount:
+	 */
+	smp_mb__after_atomic();
+
+	if (fp->fi_fds[O_WRONLY])
+		writes--;
+	if (fp->fi_fds[O_RDWR])
+		writes--;
+	if (writes > 0)
+		return -EAGAIN; /* There may be non-NFSv4 writers */
+	/*
+	 * It's possible there are non-NFSv4 write opens in progress,
+	 * but if they haven't incremented i_writecount yet then they
+	 * also haven't called break lease yet; so, they'll break this
+	 * lease soon enough.  So, all that's left to check for is NFSv4
+	 * opens:
+	 */
+	spin_lock(&fp->fi_lock);
+	list_for_each_entry(st, &fp->fi_stateids, st_perfile) {
+		if (st->st_openstp == NULL /* it's an open */ &&
+		    access_permit_write(st) &&
+		    st->st_stid.sc_client != clp) {
+			spin_unlock(&fp->fi_lock);
+			return -EAGAIN;
+		}
+	}
+	spin_unlock(&fp->fi_lock);
+	/*
+	 * There's a small chance that we could be racing with another
+	 * NFSv4 open.  However, any open that hasn't added itself to
+	 * the fi_stateids list also hasn't called break_lease yet; so,
+	 * they'll break this lease soon enough.
+	 */
+	return 0;
+}
+
+/*
+ * It's possible that between opening the dentry and setting the delegation,
+ * that it has been renamed or unlinked. Redo the lookup to verify that this
+ * hasn't happened.
+ */
+static int
+nfsd4_verify_deleg_dentry(struct nfsd4_open *open, struct nfs4_file *fp,
+			  struct svc_fh *parent)
+{
+	struct svc_export *exp;
+	struct dentry *child;
+	__be32 err;
+
+	err = nfsd_lookup_dentry(open->op_rqstp, parent,
+				 open->op_fname, open->op_fnamelen,
+				 &exp, &child);
+
+	if (err)
+		return -EAGAIN;
+
+	exp_put(exp);
+	dput(child);
+	if (child != file_dentry(rcu_dereference_protected(fp->fi_deleg_file, 1)->nf_file))
+		return -EAGAIN;
+
+	return 0;
+}
+
+/*
+ * We avoid breaking delegations held by a client due to its own activity, but
+ * clearing setuid/setgid bits on a write is an implicit activity and the client
+ * may not notice and continue using the old mode. Avoid giving out a delegation
+ * on setuid/setgid files when the client is requesting an open for write.
+ */
+static int
+nfsd4_verify_setuid_write(struct nfsd4_open *open, struct nfsd_file *nf)
+{
+	struct inode *inode = file_inode(nf->nf_file);
+
+	if ((open->op_share_access & NFS4_SHARE_ACCESS_WRITE) &&
+	    (inode->i_mode & (S_ISUID|S_ISGID)))
+		return -EAGAIN;
+	return 0;
+}
+
+/*
+ * Timestamp delegation was introduced in RFC7862. Runtime switch for disabling
+ * this feature is /sys/kernel/debug/nfsd/delegated_timestamps.
+ */
+static bool nfsd4_want_deleg_timestamps(const struct nfsd4_open *open)
+{
+	if (!nfsd_delegts_enabled)
+		return false;
+	return open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS;
+}
+
+static struct nfs4_delegation *
+nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp,
+		    struct svc_fh *parent)
+{
+	bool deleg_ts = nfsd4_want_deleg_timestamps(open);
+	struct nfs4_client *clp = stp->st_stid.sc_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfs4_file *fp = stp->st_stid.sc_file;
+	struct nfs4_clnt_odstate *odstate = stp->st_clnt_odstate;
+	struct nfs4_delegation *dp;
+	struct nfsd_file *nf = NULL;
+	struct file_lease *fl;
+	int status = 0;
+	u32 dl_type;
+
+	/*
+	 * The fi_had_conflict and nfs_get_existing_delegation checks
+	 * here are just optimizations; we'll need to recheck them at
+	 * the end:
+	 */
+	if (fp->fi_had_conflict)
+		return ERR_PTR(-EAGAIN);
+
+	/*
+	 * Try for a write delegation first. RFC8881 section 10.4 says:
+	 *
+	 *  "An OPEN_DELEGATE_WRITE delegation allows the client to handle,
+	 *   on its own, all opens."
+	 *
+	 * Furthermore, section 9.1.2 says:
+	 *
+	 *  "In the case of READ, the server may perform the corresponding
+	 *  check on the access mode, or it may choose to allow READ for
+	 *  OPEN4_SHARE_ACCESS_WRITE, to accommodate clients whose WRITE
+	 *  implementation may unavoidably do reads (e.g., due to buffer
+	 *  cache constraints)."
+	 *
+	 *  We choose to offer a write delegation for OPEN with the
+	 *  OPEN4_SHARE_ACCESS_WRITE access mode to accommodate such clients.
+	 */
+	if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
+		nf = find_writeable_file(fp);
+		dl_type = deleg_ts ? OPEN_DELEGATE_WRITE_ATTRS_DELEG : OPEN_DELEGATE_WRITE;
+	}
+
+	/*
+	 * If the file is being opened O_RDONLY or we couldn't get a O_RDWR
+	 * file for some reason, then try for a read delegation instead.
+	 */
+	if (!nf && (open->op_share_access & NFS4_SHARE_ACCESS_READ)) {
+		nf = find_readable_file(fp);
+		dl_type = deleg_ts ? OPEN_DELEGATE_READ_ATTRS_DELEG : OPEN_DELEGATE_READ;
+	}
+
+	if (!nf)
+		return ERR_PTR(-EAGAIN);
+
+	/*
+	 * File delegations and associated locks cannot be recovered if the
+	 * export is from an NFS proxy server.
+	 */
+	if (exportfs_cannot_lock(nf->nf_file->f_path.mnt->mnt_sb->s_export_op)) {
+		nfsd_file_put(nf);
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
+	spin_lock(&nn->deleg_lock);
+	spin_lock(&fp->fi_lock);
+	if (nfs4_delegation_exists(clp, fp))
+		status = -EAGAIN;
+	else if (nfsd4_verify_setuid_write(open, nf))
+		status = -EAGAIN;
+	else if (!rcu_dereference_protected(fp->fi_deleg_file,
+					    lockdep_is_held(&fp->fi_lock))) {
+		rcu_assign_pointer(fp->fi_deleg_file, nf);
+		/* increment early to prevent fi_deleg_file from being
+		 * cleared */
+		fp->fi_delegees = 1;
+		nf = NULL;
+	} else
+		fp->fi_delegees++;
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&nn->deleg_lock);
+	if (nf)
+		nfsd_file_put(nf);
+	if (status)
+		return ERR_PTR(status);
+
+	status = -ENOMEM;
+	dp = alloc_init_deleg(clp, fp, odstate, dl_type);
+	if (!dp)
+		goto out_delegees;
+	if (stp->st_stid.sc_export)
+		dp->dl_stid.sc_export = exp_get(stp->st_stid.sc_export);
+
+	fl = nfs4_alloc_init_lease(dp, 0);
+	if (!fl)
+		goto out_clnt_odstate;
+
+	status = kernel_setlease(rcu_dereference_protected(fp->fi_deleg_file, 1)->nf_file,
+				      fl->c.flc_type, &fl, NULL);
+	if (fl)
+		locks_free_lease(fl);
+	if (status)
+		goto out_clnt_odstate;
+
+	if (parent) {
+		status = nfsd4_verify_deleg_dentry(open, fp, parent);
+		if (status)
+			goto out_unlock;
+	}
+
+	status = nfsd4_check_conflicting_opens(clp, fp);
+	if (status)
+		goto out_unlock;
+
+	/*
+	 * Now that the deleg is set, check again to ensure that nothing
+	 * raced in and changed the mode while we weren't looking.
+	 */
+	status = nfsd4_verify_setuid_write(open, rcu_dereference_protected(fp->fi_deleg_file, 1));
+	if (status)
+		goto out_unlock;
+
+	status = -EAGAIN;
+	if (fp->fi_had_conflict)
+		goto out_unlock;
+
+	spin_lock(&nn->deleg_lock);
+	spin_lock(&clp->cl_lock);
+	spin_lock(&fp->fi_lock);
+	status = hash_delegation_locked(dp, fp);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&clp->cl_lock);
+	spin_unlock(&nn->deleg_lock);
+
+	if (status)
+		goto out_unlock;
+
+	return dp;
+out_unlock:
+	kernel_setlease(rcu_dereference_protected(fp->fi_deleg_file, 1)->nf_file,
+			F_UNLCK, NULL, (void **)&dp);
+out_clnt_odstate:
+	put_clnt_odstate(dp->dl_clnt_odstate);
+	nfs4_put_stid(&dp->dl_stid);
+out_delegees:
+	put_deleg_file(fp);
+	return ERR_PTR(status);
+}
+
+static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
+{
+	open->op_delegate_type = OPEN_DELEGATE_NONE_EXT;
+	if (status == -EAGAIN)
+		open->op_why_no_deleg = WND4_CONTENTION;
+	else {
+		open->op_why_no_deleg = WND4_RESOURCE;
+		switch (open->op_deleg_want) {
+		case OPEN4_SHARE_ACCESS_WANT_READ_DELEG:
+		case OPEN4_SHARE_ACCESS_WANT_WRITE_DELEG:
+		case OPEN4_SHARE_ACCESS_WANT_ANY_DELEG:
+			break;
+		case OPEN4_SHARE_ACCESS_WANT_CANCEL:
+			open->op_why_no_deleg = WND4_CANCELLED;
+			break;
+		case OPEN4_SHARE_ACCESS_WANT_NO_DELEG:
+			WARN_ON_ONCE(1);
+		}
+	}
+}
+
+static bool
+nfs4_delegation_stat(struct nfs4_delegation *dp, struct svc_fh *currentfh,
+		     struct kstat *stat)
+{
+	struct nfsd_file *nf = find_writeable_file(dp->dl_stid.sc_file);
+	struct path path;
+	int rc;
+
+	if (!nf)
+		return false;
+
+	path.mnt = currentfh->fh_export->ex_path.mnt;
+	path.dentry = file_dentry(nf->nf_file);
+
+	rc = vfs_getattr(&path, stat,
+			 STATX_MODE | STATX_SIZE | STATX_ATIME |
+			 STATX_MTIME | STATX_CTIME | STATX_CHANGE_COOKIE,
+			 AT_STATX_SYNC_AS_STAT);
+
+	nfsd_file_put(nf);
+	return rc == 0;
+}
+
+/*
+ * Add NFS4_SHARE_ACCESS_READ to the write delegation granted on OPEN
+ * with NFS4_SHARE_ACCESS_WRITE by allocating separate nfsd_file and
+ * struct file to be used for read with delegation stateid.
+ *
+ */
+static bool
+nfsd4_add_rdaccess_to_wrdeleg(struct svc_rqst *rqstp, struct nfsd4_open *open,
+			      struct svc_fh *fh, struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_file *fp;
+	struct nfsd_file *nf = NULL;
+
+	if ((open->op_share_access & NFS4_SHARE_ACCESS_BOTH) ==
+			NFS4_SHARE_ACCESS_WRITE) {
+		if (nfsd_file_acquire_opened(rqstp, fh, NFSD_MAY_READ, NULL, &nf))
+			return (false);
+		fp = stp->st_stid.sc_file;
+		spin_lock(&fp->fi_lock);
+		if (!fp->fi_fds[O_RDONLY]) {
+			__nfs4_file_get_access(fp, NFS4_SHARE_ACCESS_READ);
+			fp->fi_fds[O_RDONLY] = nf;
+			fp->fi_rdeleg_file = nfsd_file_get(fp->fi_fds[O_RDONLY]);
+			nf = NULL;
+		}
+		spin_unlock(&fp->fi_lock);
+		if (nf)
+			nfsd_file_put(nf);
+	}
+	return true;
+}
+
+/*
+ * The Linux NFS server does not offer write delegations to NFSv4.0
+ * clients in order to avoid conflicts between write delegations and
+ * GETATTRs requesting CHANGE or SIZE attributes.
+ *
+ * With NFSv4.1 and later minorversions, the SEQUENCE operation that
+ * begins each COMPOUND contains a client ID. Delegation recall can
+ * be avoided when the server recognizes the client sending a
+ * GETATTR also holds write delegation it conflicts with.
+ *
+ * However, the NFSv4.0 protocol does not enable a server to
+ * determine that a GETATTR originated from the client holding the
+ * conflicting delegation versus coming from some other client. Per
+ * RFC 7530 Section 16.7.5, the server must recall or send a
+ * CB_GETATTR even when the GETATTR originates from the client that
+ * holds the conflicting delegation.
+ *
+ * An NFSv4.0 client can trigger a pathological situation if it
+ * always sends a DELEGRETURN preceded by a conflicting GETATTR in
+ * the same COMPOUND. COMPOUND execution will always stop at the
+ * GETATTR and the DELEGRETURN will never get executed. The server
+ * eventually revokes the delegation, which can result in loss of
+ * open or lock state.
+ */
+static void
+nfs4_open_delegation(struct svc_rqst *rqstp, struct nfsd4_open *open,
+		     struct nfs4_ol_stateid *stp, struct svc_fh *currentfh,
+		     struct svc_fh *fh)
+{
+	struct nfs4_openowner *oo = openowner(stp->st_stateowner);
+	bool deleg_ts = nfsd4_want_deleg_timestamps(open);
+	struct nfs4_client *clp = stp->st_stid.sc_client;
+	struct svc_fh *parent = NULL;
+	struct nfs4_delegation *dp;
+	struct kstat stat;
+	int status = 0;
+	int cb_up;
+
+	cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
+	open->op_recall = false;
+	switch (open->op_claim_type) {
+		case NFS4_OPEN_CLAIM_PREVIOUS:
+			if (!cb_up)
+				open->op_recall = true;
+			break;
+		case NFS4_OPEN_CLAIM_NULL:
+			parent = currentfh;
+			fallthrough;
+		case NFS4_OPEN_CLAIM_FH:
+			/*
+			 * Let's not give out any delegations till everyone's
+			 * had the chance to reclaim theirs, *and* until
+			 * NLM locks have all been reclaimed:
+			 */
+			if (locks_in_grace(clp->net))
+				goto out_no_deleg;
+			if (!cb_up || !(oo->oo_flags & NFS4_OO_CONFIRMED))
+				goto out_no_deleg;
+			if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE &&
+					!clp->cl_minorversion)
+				goto out_no_deleg;
+			break;
+		default:
+			goto out_no_deleg;
+	}
+	dp = nfs4_set_delegation(open, stp, parent);
+	if (IS_ERR(dp))
+		goto out_no_deleg;
+
+	memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));
+
+	if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) {
+		struct file *f;
+
+		f = rcu_dereference_protected(dp->dl_stid.sc_file->fi_deleg_file, 1)->nf_file;
+		if (!nfsd4_add_rdaccess_to_wrdeleg(rqstp, open, fh, stp) ||
+				!nfs4_delegation_stat(dp, currentfh, &stat)) {
+			nfs4_put_stid(&dp->dl_stid);
+			destroy_delegation(dp);
+			goto out_no_deleg;
+		}
+		open->op_delegate_type = deleg_ts ? OPEN_DELEGATE_WRITE_ATTRS_DELEG :
+						    OPEN_DELEGATE_WRITE;
+		dp->dl_cb_fattr.ncf_initial_cinfo = nfsd4_change_attribute(&stat);
+		dp->dl_atime = stat.atime;
+		dp->dl_ctime = stat.ctime;
+		dp->dl_mtime = stat.mtime;
+		spin_lock(&f->f_lock);
+		if (deleg_ts)
+			f->f_mode |= FMODE_NOCMTIME;
+		spin_unlock(&f->f_lock);
+		trace_nfsd_deleg_write(&dp->dl_stid.sc_stateid);
+	} else {
+		open->op_delegate_type = deleg_ts && nfs4_delegation_stat(dp, currentfh, &stat) ?
+					 OPEN_DELEGATE_READ_ATTRS_DELEG : OPEN_DELEGATE_READ;
+		dp->dl_atime = stat.atime;
+		trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid);
+	}
+	nfs4_put_stid(&dp->dl_stid);
+	return;
+out_no_deleg:
+	open->op_delegate_type = OPEN_DELEGATE_NONE;
+
+	/* 4.1 client asking for a delegation? */
+	if (open->op_deleg_want)
+		nfsd4_open_deleg_none_ext(open, status);
+	return;
+}
+
+static void nfsd4_deleg_xgrade_none_ext(struct nfsd4_open *open,
+					struct nfs4_delegation *dp)
+{
+	if (deleg_is_write(dp->dl_type)) {
+		if (open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_READ_DELEG) {
+			open->op_delegate_type = OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
+		} else if (open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_WRITE_DELEG) {
+			open->op_delegate_type = OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
+		}
+	}
+	/* Otherwise the client must be confused wanting a delegation
+	 * it already has, therefore we don't return
+	 * OPEN_DELEGATE_NONE_EXT and reason.
+	 */
+}
+
+/* Are we returning only a delegation stateid? */
+static bool open_xor_delegation(struct nfsd4_open *open)
+{
+	if (!(open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION))
+		return false;
+	/* Did we actually get a delegation? */
+	if (!deleg_is_read(open->op_delegate_type) && !deleg_is_write(open->op_delegate_type))
+		return false;
+	return true;
+}
+
+/**
+ * nfsd4_process_open2 - finish open processing
+ * @rqstp: the RPC transaction being executed
+ * @current_fh: NFSv4 COMPOUND's current filehandle
+ * @open: OPEN arguments
+ *
+ * If successful, (1) truncate the file if open->op_truncate was
+ * set, (2) set open->op_stateid, (3) set open->op_delegation.
+ *
+ * Returns %nfs_ok on success; otherwise an nfs4stat value in
+ * network byte order is returned.
+ */
+__be32
+nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfs4_client *cl = open->op_openowner->oo_owner.so_client;
+	struct nfs4_file *fp = NULL;
+	struct nfs4_ol_stateid *stp = NULL;
+	struct nfs4_delegation *dp = NULL;
+	__be32 status;
+	bool new_stp = false;
+
+	/*
+	 * Lookup file; if found, lookup stateid and check open request,
+	 * and check for delegations in the process of being recalled.
+	 * If not found, create the nfs4_file struct
+	 */
+	fp = nfsd4_file_hash_insert(open->op_file, current_fh);
+	if (unlikely(!fp))
+		return nfserr_jukebox;
+	if (fp != open->op_file) {
+		status = nfs4_check_deleg(cl, open, &dp);
+		if (status)
+			goto out;
+		if (dp && nfsd4_is_deleg_cur(open) &&
+				(dp->dl_stid.sc_file != fp)) {
+			/*
+			 * RFC8881 section 8.2.4 mandates the server to return
+			 * NFS4ERR_BAD_STATEID if the selected table entry does
+			 * not match the current filehandle. However returning
+			 * NFS4ERR_BAD_STATEID in the OPEN can cause the client
+			 * to repeatedly retry the operation with the same
+			 * stateid, since the stateid itself is valid. To avoid
+			 * this situation NFSD returns NFS4ERR_INVAL instead.
+			 */
+			status = nfserr_inval;
+			goto out;
+		}
+		stp = nfsd4_find_and_lock_existing_open(fp, open);
+	} else {
+		open->op_file = NULL;
+		status = nfserr_bad_stateid;
+		if (nfsd4_is_deleg_cur(open))
+			goto out;
+	}
+
+	if (!stp) {
+		stp = init_open_stateid(fp, open);
+		if (!stp) {
+			status = nfserr_jukebox;
+			goto out;
+		}
+
+		if (!open->op_stp) {
+			new_stp = true;
+			stp->st_stid.sc_export =
+				exp_get(current_fh->fh_export);
+		}
+	}
+
+	/*
+	 * OPEN the file, or upgrade an existing OPEN.
+	 * If truncate fails, the OPEN fails.
+	 *
+	 * stp is already locked.
+	 */
+	if (!new_stp) {
+		/* Stateid was found, this is an OPEN upgrade */
+		status = nfs4_upgrade_open(rqstp, fp, current_fh, stp, open);
+		if (status) {
+			mutex_unlock(&stp->st_mutex);
+			goto out;
+		}
+	} else {
+		status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open, true);
+		if (status) {
+			release_open_stateid(stp);
+			mutex_unlock(&stp->st_mutex);
+			goto out;
+		}
+
+		stp->st_clnt_odstate = find_or_hash_clnt_odstate(fp,
+							open->op_odstate);
+		if (stp->st_clnt_odstate == open->op_odstate)
+			open->op_odstate = NULL;
+	}
+
+	nfs4_inc_and_copy_stateid(&open->op_stateid, &stp->st_stid);
+	mutex_unlock(&stp->st_mutex);
+
+	if (nfsd4_has_session(&resp->cstate)) {
+		if (open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_NO_DELEG) {
+			open->op_delegate_type = OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_WANTED;
+			goto nodeleg;
+		}
+	}
+
+	/*
+	* Attempt to hand out a delegation. No error return, because the
+	* OPEN succeeds even if we fail.
+	*/
+	nfs4_open_delegation(rqstp, open, stp,
+		&resp->cstate.current_fh, current_fh);
+
+	/*
+	 * If there is an existing open stateid, it must be updated and
+	 * returned. Only respect WANT_OPEN_XOR_DELEGATION when a new
+	 * open stateid would have to be created.
+	 */
+	if (new_stp && open_xor_delegation(open)) {
+		memcpy(&open->op_stateid, &zero_stateid, sizeof(open->op_stateid));
+		open->op_rflags |= OPEN4_RESULT_NO_OPEN_STATEID;
+		release_open_stateid(stp);
+	}
+nodeleg:
+	status = nfs_ok;
+	trace_nfsd_open(&stp->st_stid.sc_stateid);
+out:
+	/* 4.1 client trying to upgrade/downgrade delegation? */
+	if (open->op_delegate_type == OPEN_DELEGATE_NONE && dp &&
+	    open->op_deleg_want)
+		nfsd4_deleg_xgrade_none_ext(open, dp);
+
+	if (fp)
+		put_nfs4_file(fp);
+	if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
+		open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+	/*
+	* To finish the open response, we just need to set the rflags.
+	*/
+	open->op_rflags |= NFS4_OPEN_RESULT_LOCKTYPE_POSIX;
+	if (nfsd4_has_session(&resp->cstate))
+		open->op_rflags |= NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK;
+	else if (!(open->op_openowner->oo_flags & NFS4_OO_CONFIRMED))
+		open->op_rflags |= NFS4_OPEN_RESULT_CONFIRM;
+
+	if (dp)
+		nfs4_put_stid(&dp->dl_stid);
+	if (stp)
+		nfs4_put_stid(&stp->st_stid);
+
+	return status;
+}
+
+void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+			      struct nfsd4_open *open)
+{
+	if (open->op_openowner)
+		nfs4_put_stateowner(&open->op_openowner->oo_owner);
+	if (open->op_file)
+		kmem_cache_free(file_slab, open->op_file);
+	if (open->op_stp)
+		nfs4_put_stid(&open->op_stp->st_stid);
+	if (open->op_odstate)
+		kmem_cache_free(odstate_slab, open->op_odstate);
+}
+
+__be32
+nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	clientid_t *clid = &u->renew;
+	struct nfs4_client *clp;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	trace_nfsd_clid_renew(clid);
+	status = set_client(clid, cstate, nn);
+	if (status)
+		return status;
+	clp = cstate->clp;
+	if (!list_empty(&clp->cl_delegations)
+			&& clp->cl_cb_state != NFSD4_CB_UP)
+		return nfserr_cb_path_down;
+	return nfs_ok;
+}
+
+static void
+nfsd4_end_grace(struct nfsd_net *nn)
+{
+	/*
+	 * nfsd4_end_grace() can be entered concurrently from the
+	 * laundromat workqueue and from an nfsd compound thread
+	 * handling RECLAIM_COMPLETE.  Without serialization, both
+	 * callers can observe NFSD_NET_GRACE_ENDED clear and proceed
+	 * into nfsd4_record_grace_done().  For tracking ops whose
+	 * grace_done drains reclaim_str_hashtbl, that results in
+	 * list corruption and a double free of every
+	 * nfs4_client_reclaim entry.  Use an atomic test-and-set so
+	 * exactly one caller proceeds.
+	 */
+	if (test_and_set_bit(NFSD_NET_GRACE_ENDED, &nn->flags))
+		return;
+
+	trace_nfsd_grace_complete(nn);
+	/*
+	 * If the server goes down again right now, an NFSv4
+	 * client will still be allowed to reclaim after it comes back up,
+	 * even if it hasn't yet had a chance to reclaim state this time.
+	 *
+	 */
+	nfsd4_record_grace_done(nn);
+	/*
+	 * At this point, NFSv4 clients can still reclaim.  But if the
+	 * server crashes, any that have not yet reclaimed will be out
+	 * of luck on the next boot.
+	 *
+	 * (NFSv4.1+ clients are considered to have reclaimed once they
+	 * call RECLAIM_COMPLETE.  NFSv4.0 clients are considered to
+	 * have reclaimed after their first OPEN.)
+	 */
+	locks_end_grace(&nn->nfsd4_manager);
+	/*
+	 * At this point, and once lockd and/or any other containers
+	 * exit their grace period, further reclaims will fail and
+	 * regular locking can resume.
+	 */
+}
+
+/**
+ * nfsd4_force_end_grace - forcibly end the NFSv4 grace period
+ * @nn: network namespace for the server instance to be updated
+ *
+ * Forces bypass of normal grace period completion, then schedules
+ * the laundromat to end the grace period immediately. Does not wait
+ * for the grace period to fully terminate before returning.
+ *
+ * Return values:
+ *   %true: Grace termination schedule
+ *   %false: No action was taken
+ */
+bool nfsd4_force_end_grace(struct nfsd_net *nn)
+{
+	if (!nn->client_tracking_ops)
+		return false;
+	if (test_bit(NFSD_NET_GRACE_ENDED, &nn->flags))
+		return false;
+	/* laundromat_work must be initialised now, though it might be disabled */
+	set_bit(NFSD_NET_GRACE_END_FORCED, &nn->flags);
+	/* mod_delayed_work() doesn't queue work after
+	 * nfs4_state_shutdown_net() has called disable_delayed_work_sync()
+	 */
+	mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+	return true;
+}
+
+/*
+ * If we've waited a lease period but there are still clients trying to
+ * reclaim, wait a little longer to give them a chance to finish.
+ */
+static bool clients_still_reclaiming(struct nfsd_net *nn)
+{
+	time64_t double_grace_period_end = nn->boot_time_bt +
+					   2 * nn->nfsd4_lease;
+
+	if (test_bit(NFSD_NET_GRACE_END_FORCED, &nn->flags))
+		return false;
+	if (test_bit(NFSD_NET_TRACK_RECLAIM_COMPLETES, &nn->flags)) {
+		int size;
+
+		down_read(&nn->reclaim_str_hashtbl_lock);
+		size = nn->reclaim_str_hashtbl_size;
+		up_read(&nn->reclaim_str_hashtbl_lock);
+		if (atomic_read(&nn->nr_reclaim_complete) == size)
+			return false;
+	}
+	if (!test_and_clear_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags))
+		return false;
+	/*
+	 * If we've given them *two* lease times to reclaim, and they're
+	 * still not done, give up:
+	 */
+	if (ktime_get_boottime_seconds() > double_grace_period_end)
+		return false;
+	return true;
+}
+
+struct laundry_time {
+	time64_t cutoff;
+	time64_t new_timeo;
+};
+
+static bool state_expired(struct laundry_time *lt, time64_t last_refresh)
+{
+	time64_t time_remaining;
+
+	if (last_refresh < lt->cutoff)
+		return true;
+	time_remaining = last_refresh - lt->cutoff;
+	lt->new_timeo = min(lt->new_timeo, time_remaining);
+	return false;
+}
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+void nfsd4_ssc_init_umount_work(struct nfsd_net *nn)
+{
+	spin_lock_init(&nn->nfsd_ssc_lock);
+	INIT_LIST_HEAD(&nn->nfsd_ssc_mount_list);
+	init_waitqueue_head(&nn->nfsd_ssc_waitq);
+}
+
+/*
+ * This is called when nfsd is being shutdown, after all inter_ssc
+ * cleanup were done, to destroy the ssc delayed unmount list.
+ */
+static void nfsd4_ssc_shutdown_umount(struct nfsd_net *nn)
+{
+	struct nfsd4_ssc_umount_item *ni = NULL;
+	struct nfsd4_ssc_umount_item *tmp;
+
+	spin_lock(&nn->nfsd_ssc_lock);
+	list_for_each_entry_safe(ni, tmp, &nn->nfsd_ssc_mount_list, nsui_list) {
+		list_del(&ni->nsui_list);
+		spin_unlock(&nn->nfsd_ssc_lock);
+		mntput(ni->nsui_vfsmount);
+		kfree(ni);
+		spin_lock(&nn->nfsd_ssc_lock);
+	}
+	spin_unlock(&nn->nfsd_ssc_lock);
+}
+
+static void nfsd4_ssc_expire_umount(struct nfsd_net *nn)
+{
+	bool do_wakeup = false;
+	struct nfsd4_ssc_umount_item *ni;
+
+restart:
+	spin_lock(&nn->nfsd_ssc_lock);
+	list_for_each_entry(ni, &nn->nfsd_ssc_mount_list, nsui_list) {
+		if (!time_after(jiffies, ni->nsui_expire))
+			break;
+		if (refcount_read(&ni->nsui_refcnt) > 1)
+			continue;
+
+		/* Prevent concurrent setup during unmount */
+		ni->nsui_busy = true;
+		spin_unlock(&nn->nfsd_ssc_lock);
+		mntput(ni->nsui_vfsmount);
+		spin_lock(&nn->nfsd_ssc_lock);
+
+		/* Force concurrent scanners to restart */
+		list_del(&ni->nsui_list);
+		kfree(ni);
+
+		/* wakeup ssc_connect waiters */
+		do_wakeup = true;
+		/*
+		 * Concurrent nfsd4_ssc_cancel_dul() can free any item
+		 * on the list under nfsd_ssc_lock while mntput() runs
+		 * above.  Restart from the head; the list is short and
+		 * the expire worker is periodic, so this is cheap.
+		 */
+		spin_unlock(&nn->nfsd_ssc_lock);
+		goto restart;
+	}
+	if (do_wakeup)
+		wake_up_all(&nn->nfsd_ssc_waitq);
+	spin_unlock(&nn->nfsd_ssc_lock);
+}
+#endif
+
+/* Check if any lock belonging to this lockowner has any blockers */
+static bool
+nfs4_lockowner_has_blockers(struct nfs4_lockowner *lo)
+{
+	struct file_lock_context *ctx;
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_file *nf;
+
+	list_for_each_entry(stp, &lo->lo_owner.so_stateids, st_perstateowner) {
+		nf = stp->st_stid.sc_file;
+		ctx = locks_inode_context(nf->fi_inode);
+		if (!ctx)
+			continue;
+		if (locks_owner_has_blockers(ctx, lo))
+			return true;
+	}
+	return false;
+}
+
+static bool
+nfs4_anylock_blockers(struct nfs4_client *clp)
+{
+	int i;
+	struct nfs4_stateowner *so;
+	struct nfs4_lockowner *lo;
+
+	if (atomic_read(&clp->cl_delegs_in_recall))
+		return true;
+	spin_lock(&clp->cl_lock);
+	for (i = 0; i < OWNER_HASH_SIZE; i++) {
+		list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i],
+				so_strhash) {
+			if (so->so_is_open_owner)
+				continue;
+			lo = lockowner(so);
+			if (nfs4_lockowner_has_blockers(lo)) {
+				spin_unlock(&clp->cl_lock);
+				return true;
+			}
+		}
+	}
+	spin_unlock(&clp->cl_lock);
+	return false;
+}
+
+static void
+nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
+				struct laundry_time *lt)
+{
+	unsigned int maxreap, reapcnt = 0;
+	struct list_head *pos, *next;
+	struct nfs4_client *clp;
+
+	maxreap = (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients) ?
+			NFSD_CLIENT_MAX_TRIM_PER_RUN : 0;
+	INIT_LIST_HEAD(reaplist);
+	spin_lock(&nn->client_lock);
+	list_for_each_safe(pos, next, &nn->client_lru) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+		if (clp->cl_state == NFSD4_EXPIRABLE)
+			goto exp_client;
+		if (!state_expired(lt, clp->cl_time))
+			break;
+		if (!atomic_read(&clp->cl_rpc_users)) {
+			if (clp->cl_state == NFSD4_ACTIVE)
+				atomic_inc(&nn->nfsd_courtesy_clients);
+			clp->cl_state = NFSD4_COURTESY;
+		}
+		if (!client_has_state(clp))
+			goto exp_client;
+		if (!nfs4_anylock_blockers(clp))
+			if (reapcnt >= maxreap)
+				continue;
+exp_client:
+		if (!mark_client_expired_locked(clp)) {
+			list_add(&clp->cl_lru, reaplist);
+			reapcnt++;
+		}
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static void
+nfs4_get_courtesy_client_reaplist(struct nfsd_net *nn,
+				struct list_head *reaplist)
+{
+	unsigned int maxreap = 0, reapcnt = 0;
+	struct list_head *pos, *next;
+	struct nfs4_client *clp;
+
+	maxreap = NFSD_CLIENT_MAX_TRIM_PER_RUN;
+	INIT_LIST_HEAD(reaplist);
+
+	spin_lock(&nn->client_lock);
+	list_for_each_safe(pos, next, &nn->client_lru) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+		if (clp->cl_state == NFSD4_ACTIVE)
+			break;
+		if (reapcnt >= maxreap)
+			break;
+		if (!mark_client_expired_locked(clp)) {
+			list_add(&clp->cl_lru, reaplist);
+			reapcnt++;
+		}
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static void
+nfs4_process_client_reaplist(struct list_head *reaplist)
+{
+	struct list_head *pos, *next;
+	struct nfs4_client *clp;
+
+	list_for_each_safe(pos, next, reaplist) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+		trace_nfsd_clid_purged(&clp->cl_clientid);
+		list_del_init(&clp->cl_lru);
+		expire_client(clp);
+	}
+}
+
+static void nfs40_clean_admin_revoked(struct nfsd_net *nn,
+				      struct laundry_time *lt)
+{
+	struct nfs4_client *clp;
+
+	spin_lock(&nn->client_lock);
+	if (nn->nfs40_last_revoke == 0 ||
+	    nn->nfs40_last_revoke > lt->cutoff) {
+		spin_unlock(&nn->client_lock);
+		return;
+	}
+	nn->nfs40_last_revoke = 0;
+
+retry:
+	list_for_each_entry(clp, &nn->client_lru, cl_lru) {
+		unsigned long id, tmp;
+		struct nfs4_stid *stid;
+
+		if (atomic_read(&clp->cl_admin_revoked) == 0)
+			continue;
+		if (is_client_expired(clp))
+			continue;
+
+		spin_lock(&clp->cl_lock);
+		idr_for_each_entry_ul(&clp->cl_stateids, stid, tmp, id)
+			if (stid->sc_status & SC_STATUS_ADMIN_REVOKED) {
+				refcount_inc(&stid->sc_count);
+				atomic_inc(&clp->cl_rpc_users);
+				spin_unlock(&nn->client_lock);
+				/* this function drops ->cl_lock */
+				nfsd4_drop_revoked_stid(stid);
+				nfs4_put_stid(stid);
+				spin_lock(&nn->client_lock);
+				put_client_no_renew_locked(clp);
+				goto retry;
+			}
+		spin_unlock(&clp->cl_lock);
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static time64_t
+nfs4_laundromat(struct nfsd_net *nn)
+{
+	struct nfs4_openowner *oo;
+	struct nfs4_delegation *dp;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd4_blocked_lock *nbl;
+	struct list_head *pos, *next, reaplist;
+	struct laundry_time lt = {
+		.cutoff = ktime_get_boottime_seconds() - nn->nfsd4_lease,
+		.new_timeo = nn->nfsd4_lease
+	};
+	struct nfs4_cpntf_state *cps;
+	struct nfs4_client *clp;
+	copy_stateid_t *cps_t;
+	int i;
+
+	if (clients_still_reclaiming(nn)) {
+		lt.new_timeo = 0;
+		goto out;
+	}
+	nfsd4_end_grace(nn);
+
+	spin_lock(&nn->s2s_cp_lock);
+	/* s2s_cp_stateids holds only COPY_NOTIFY stateids */
+	idr_for_each_entry(&nn->s2s_cp_stateids, cps_t, i) {
+		cps = container_of(cps_t, struct nfs4_cpntf_state, cp_stateid);
+		if (state_expired(&lt, cps->cpntf_time))
+			revoke_cpntf_state_locked(nn, cps);
+	}
+	spin_unlock(&nn->s2s_cp_lock);
+	nfsd4_async_copy_reaper(nn);
+	nfs4_get_client_reaplist(nn, &reaplist, &lt);
+	nfs4_process_client_reaplist(&reaplist);
+
+	nfs40_clean_admin_revoked(nn, &lt);
+
+	spin_lock(&nn->deleg_lock);
+	list_for_each_safe(pos, next, &nn->del_recall_lru) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		if (!state_expired(&lt, dp->dl_time))
+			break;
+		clp = dp->dl_stid.sc_client;
+		spin_lock(&nn->client_lock);
+		if (is_client_expired(clp)) {
+			spin_unlock(&nn->client_lock);
+			continue;
+		}
+		/*
+		 * Pin without reviving: get_client_locked() would
+		 * flip a courtesy client back to NFSD4_ACTIVE.
+		 */
+		atomic_inc(&clp->cl_rpc_users);
+		spin_unlock(&nn->client_lock);
+		refcount_inc(&dp->dl_stid.sc_count);
+		unhash_delegation_locked(dp, SC_STATUS_REVOKED);
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&nn->deleg_lock);
+	while (!list_empty(&reaplist)) {
+		dp = list_first_entry(&reaplist, struct nfs4_delegation,
+					dl_recall_lru);
+		clp = dp->dl_stid.sc_client;
+		list_del_init(&dp->dl_recall_lru);
+		revoke_delegation(dp);
+		put_client_no_renew(clp);
+	}
+
+	spin_lock(&nn->client_lock);
+	while (!list_empty(&nn->close_lru)) {
+		oo = list_first_entry(&nn->close_lru, struct nfs4_openowner,
+					oo_close_lru);
+		if (!state_expired(&lt, oo->oo_time))
+			break;
+		list_del_init(&oo->oo_close_lru);
+		clp = oo->oo_owner.so_client;
+		if (is_client_expired(clp))
+			continue;
+		stp = oo->oo_last_closed_stid;
+		oo->oo_last_closed_stid = NULL;
+		atomic_inc(&clp->cl_rpc_users);
+		spin_unlock(&nn->client_lock);
+		nfs4_put_stid(&stp->st_stid);
+		spin_lock(&nn->client_lock);
+		put_client_no_renew_locked(clp);
+	}
+	spin_unlock(&nn->client_lock);
+
+	/*
+	 * It's possible for a client to try and acquire an already held lock
+	 * that is being held for a long time, and then lose interest in it.
+	 * So, we clean out any un-revisited request after a lease period
+	 * under the assumption that the client is no longer interested.
+	 *
+	 * RFC5661, sec. 9.6 states that the client must not rely on getting
+	 * notifications and must continue to poll for locks, even when the
+	 * server supports them. Thus this shouldn't lead to clients blocking
+	 * indefinitely once the lock does become free.
+	 */
+	BUG_ON(!list_empty(&reaplist));
+	spin_lock(&nn->client_lock);
+	spin_lock(&nn->blocked_locks_lock);
+	list_for_each_safe(pos, next, &nn->blocked_locks_lru) {
+		nbl = list_entry(pos, struct nfsd4_blocked_lock, nbl_lru);
+		if (!state_expired(&lt, nbl->nbl_time))
+			break;
+		clp = nbl_client(nbl);
+		if (is_client_expired(clp))
+			continue;
+		atomic_inc(&clp->cl_rpc_users);
+		list_move(&nbl->nbl_lru, &reaplist);
+		list_del_init(&nbl->nbl_list);
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+	spin_unlock(&nn->client_lock);
+
+	while (!list_empty(&reaplist)) {
+		nbl = list_first_entry(&reaplist,
+					struct nfsd4_blocked_lock, nbl_lru);
+		clp = nbl_client(nbl);
+		list_del_init(&nbl->nbl_lru);
+		free_blocked_lock(nbl);
+		put_client_no_renew(clp);
+	}
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+	/* service the server-to-server copy delayed unmount list */
+	nfsd4_ssc_expire_umount(nn);
+#endif
+	if (atomic_long_read(&num_delegations) >= max_delegations)
+		deleg_reaper(nn);
+out:
+	return max_t(time64_t, lt.new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT);
+}
+
+static void laundromat_main(struct work_struct *);
+
+static void
+laundromat_main(struct work_struct *laundry)
+{
+	time64_t t;
+	struct delayed_work *dwork = to_delayed_work(laundry);
+	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
+					   laundromat_work);
+
+	t = nfs4_laundromat(nn);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, t*HZ);
+}
+
+static void
+courtesy_client_reaper(struct nfsd_net *nn)
+{
+	struct list_head reaplist;
+
+	nfs4_get_courtesy_client_reaplist(nn, &reaplist);
+	nfs4_process_client_reaplist(&reaplist);
+}
+
+static void
+deleg_reaper(struct nfsd_net *nn)
+{
+	struct list_head *pos, *next;
+	struct nfs4_client *clp;
+
+	spin_lock(&nn->client_lock);
+	list_for_each_safe(pos, next, &nn->client_lru) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+
+		if (clp->cl_state != NFSD4_ACTIVE)
+			continue;
+		if (list_empty(&clp->cl_delegations))
+			continue;
+		if (atomic_read(&clp->cl_delegs_in_recall))
+			continue;
+		if (ktime_get_boottime_seconds() - clp->cl_ra_time < 5)
+			continue;
+		if (clp->cl_cb_state != NFSD4_CB_UP)
+			continue;
+		if (test_and_set_bit(NFSD4_CALLBACK_RUNNING, &clp->cl_ra->ra_cb.cb_flags))
+			continue;
+
+		/* release in nfsd4_cb_recall_any_release */
+		kref_get(&clp->cl_nfsdfs.cl_ref);
+		clp->cl_ra_time = ktime_get_boottime_seconds();
+		clp->cl_ra->ra_keep = 0;
+		clp->cl_ra->ra_bmval[0] = BIT(RCA4_TYPE_MASK_RDATA_DLG) |
+						BIT(RCA4_TYPE_MASK_WDATA_DLG);
+		trace_nfsd_cb_recall_any(clp->cl_ra);
+		nfsd4_run_cb(&clp->cl_ra->ra_cb);
+	}
+	spin_unlock(&nn->client_lock);
+}
+
+static void
+nfsd4_state_shrinker_worker(struct work_struct *work)
+{
+	struct nfsd_net *nn = container_of(work, struct nfsd_net,
+				nfsd_shrinker_work);
+
+	courtesy_client_reaper(nn);
+	deleg_reaper(nn);
+}
+
+static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp)
+{
+	if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle))
+		return nfserr_bad_stateid;
+	return nfs_ok;
+}
+
+static
+__be32 nfs4_check_openmode(struct nfs4_ol_stateid *stp, int flags)
+{
+        __be32 status = nfserr_openmode;
+
+	/* For lock stateid's, we test the parent open, not the lock: */
+	if (stp->st_openstp)
+		stp = stp->st_openstp;
+	if ((flags & WR_STATE) && !access_permit_write(stp))
+                goto out;
+	if ((flags & RD_STATE) && !access_permit_read(stp))
+                goto out;
+	status = nfs_ok;
+out:
+	return status;
+}
+
+static inline __be32
+check_special_stateids(struct net *net, svc_fh *current_fh, stateid_t *stateid, int flags)
+{
+	if (ONE_STATEID(stateid) && (flags & RD_STATE))
+		return nfs_ok;
+	else if (opens_in_grace(net)) {
+		/* Answer in remaining cases depends on existence of
+		 * conflicting state; so we must wait out the grace period. */
+		return nfserr_grace;
+	} else if (flags & WR_STATE)
+		return nfs4_share_conflict(current_fh,
+				NFS4_SHARE_DENY_WRITE);
+	else /* (flags & RD_STATE) && ZERO_STATEID(stateid) */
+		return nfs4_share_conflict(current_fh,
+				NFS4_SHARE_DENY_READ);
+}
+
+static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
+{
+	/*
+	 * When sessions are used the stateid generation number is ignored
+	 * when it is zero.
+	 */
+	if (has_session && in->si_generation == 0)
+		return nfs_ok;
+
+	if (in->si_generation == ref->si_generation)
+		return nfs_ok;
+
+	/* If the client sends us a stateid from the future, it's buggy: */
+	if (nfsd4_stateid_generation_after(in, ref))
+		return nfserr_bad_stateid;
+	/*
+	 * However, we could see a stateid from the past, even from a
+	 * non-buggy client.  For example, if the client sends a lock
+	 * while some IO is outstanding, the lock may bump si_generation
+	 * while the IO is still in flight.  The client could avoid that
+	 * situation by waiting for responses on all the IO requests,
+	 * but better performance may result in retrying IO that
+	 * receives an old_stateid error if requests are rarely
+	 * reordered in flight:
+	 */
+	return nfserr_old_stateid;
+}
+
+static __be32 nfsd4_stid_check_stateid_generation(stateid_t *in, struct nfs4_stid *s, bool has_session)
+{
+	__be32 ret;
+
+	spin_lock(&s->sc_lock);
+	ret = nfsd4_verify_open_stid(s);
+	if (ret == nfs_ok)
+		ret = check_stateid_generation(in, &s->sc_stateid, has_session);
+	spin_unlock(&s->sc_lock);
+	if (ret == nfserr_admin_revoked)
+		nfsd40_drop_revoked_stid(s->sc_client,
+					&s->sc_stateid);
+	return ret;
+}
+
+static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols)
+{
+	if (ols->st_stateowner->so_is_open_owner &&
+	    !(openowner(ols->st_stateowner)->oo_flags & NFS4_OO_CONFIRMED))
+		return nfserr_bad_stateid;
+	return nfs_ok;
+}
+
+static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
+{
+	struct nfs4_stid *s;
+	__be32 status = nfserr_bad_stateid;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+		CLOSE_STATEID(stateid))
+		return status;
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, stateid);
+	if (!s)
+		goto out_unlock;
+	status = nfsd4_stid_check_stateid_generation(stateid, s, 1);
+	if (status)
+		goto out_unlock;
+	status = nfsd4_verify_open_stid(s);
+	if (status)
+		goto out_unlock;
+
+	switch (s->sc_type) {
+	case SC_TYPE_DELEG:
+		status = nfs_ok;
+		break;
+	case SC_TYPE_OPEN:
+	case SC_TYPE_LOCK:
+		status = nfsd4_check_openowner_confirmed(openlockstateid(s));
+		break;
+	default:
+		printk("unknown stateid type %x\n", s->sc_type);
+		status = nfserr_bad_stateid;
+	}
+out_unlock:
+	spin_unlock(&cl->cl_lock);
+	if (status == nfserr_admin_revoked)
+		nfsd40_drop_revoked_stid(cl, stateid);
+	return status;
+}
+
+__be32
+nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
+		     stateid_t *stateid,
+		     unsigned short typemask, unsigned short statusmask,
+		     struct nfs4_stid **s, struct nfsd_net *nn)
+{
+	__be32 status;
+	struct nfs4_stid *stid;
+	bool return_revoked = false;
+
+	/*
+	 *  only return revoked delegations if explicitly asked.
+	 *  otherwise we report revoked or bad_stateid status.
+	 */
+	if (statusmask & SC_STATUS_REVOKED)
+		return_revoked = true;
+	if (typemask & SC_TYPE_DELEG)
+		/* Always allow REVOKED for DELEG so we can
+		 * return the appropriate error.
+		 */
+		statusmask |= SC_STATUS_REVOKED;
+
+	statusmask |= SC_STATUS_ADMIN_REVOKED | SC_STATUS_FREEABLE;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+		CLOSE_STATEID(stateid))
+		return nfserr_bad_stateid;
+	status = set_client(&stateid->si_opaque.so_clid, cstate, nn);
+	if (status == nfserr_stale_clientid) {
+		if (cstate->session)
+			return nfserr_bad_stateid;
+		return nfserr_stale_stateid;
+	}
+	if (status)
+		return status;
+	stid = find_stateid_by_type(cstate->clp, stateid, typemask, statusmask);
+	if (!stid)
+		return nfserr_bad_stateid;
+	if ((stid->sc_status & SC_STATUS_REVOKED) && !return_revoked) {
+		nfs4_put_stid(stid);
+		return nfserr_deleg_revoked;
+	}
+	if (stid->sc_status & SC_STATUS_ADMIN_REVOKED) {
+		nfsd40_drop_revoked_stid(cstate->clp, stateid);
+		nfs4_put_stid(stid);
+		return nfserr_admin_revoked;
+	}
+	*s = stid;
+	return nfs_ok;
+}
+
+static struct nfsd_file *
+nfs4_find_file(struct nfs4_stid *s, int flags)
+{
+	struct nfsd_file *ret = NULL;
+
+	if (!s || s->sc_status)
+		return NULL;
+
+	switch (s->sc_type) {
+	case SC_TYPE_DELEG:
+	case SC_TYPE_OPEN:
+	case SC_TYPE_LOCK:
+		if (flags & RD_STATE)
+			ret = find_readable_file(s->sc_file);
+		else
+			ret = find_writeable_file(s->sc_file);
+	}
+
+	return ret;
+}
+
+static __be32
+nfs4_check_olstateid(struct nfs4_ol_stateid *ols, int flags)
+{
+	__be32 status;
+
+	status = nfsd4_check_openowner_confirmed(ols);
+	if (status)
+		return status;
+	return nfs4_check_openmode(ols, flags);
+}
+
+static __be32
+nfs4_check_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfs4_stid *s,
+		struct nfsd_file **nfp, int flags)
+{
+	int acc = (flags & RD_STATE) ? NFSD_MAY_READ : NFSD_MAY_WRITE;
+	struct nfsd_file *nf;
+	__be32 status;
+
+	nf = nfs4_find_file(s, flags);
+	if (nf) {
+		status = nfsd_permission(&rqstp->rq_cred,
+					 fhp->fh_export, fhp->fh_dentry,
+				acc | NFSD_MAY_OWNER_OVERRIDE);
+		if (status) {
+			nfsd_file_put(nf);
+			goto out;
+		}
+	} else {
+		status = nfsd_file_acquire(rqstp, fhp, acc, &nf);
+		if (status)
+			return status;
+	}
+	*nfp = nf;
+out:
+	return status;
+}
+
+static void _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps)
+{
+	WARN_ON_ONCE(cps->cp_stateid.cs_type != NFS4_COPYNOTIFY_STID);
+	if (refcount_dec_and_test(&cps->cp_stateid.cs_count)) {
+		nfsd4_unhash_cpntf_state(nn, cps);
+		kfree(cps);
+	}
+}
+/*
+ * A READ from an inter server to server COPY will have a
+ * copy stateid. Look up the copy notify stateid from the
+ * idr structure and take a reference on it.
+ */
+__be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+			  struct nfs4_client *clp,
+			  struct nfs4_cpntf_state **cps)
+{
+	copy_stateid_t *cps_t;
+	struct nfs4_cpntf_state *state = NULL;
+
+	if (st->si_opaque.so_clid.cl_id != nn->s2s_cp_cl_id)
+		return nfserr_bad_stateid;
+	spin_lock(&nn->s2s_cp_lock);
+	/* s2s_cp_stateids holds only COPY_NOTIFY stateids */
+	cps_t = idr_find(&nn->s2s_cp_stateids, st->si_opaque.so_id);
+	if (cps_t) {
+		state = container_of(cps_t, struct nfs4_cpntf_state,
+				     cp_stateid);
+		if (!clp) {
+			refcount_inc(&state->cp_stateid.cs_count);
+		} else if (memcmp(&clp->cl_clientid, &state->cp_p_clid,
+				  sizeof(clientid_t))) {
+			/*
+			 * OFFLOAD_CANCEL: only the creating client may cancel.
+			 * so_id is guessable, so without this check any client
+			 * could free another's cpntf state.
+			 */
+			state = NULL;
+			goto unlock;
+		} else {
+			revoke_cpntf_state_locked(nn, state);
+		}
+	}
+unlock:
+	spin_unlock(&nn->s2s_cp_lock);
+	if (!state)
+		return nfserr_bad_stateid;
+	if (!clp)
+		*cps = state;
+	return 0;
+}
+
+static __be32 find_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+			       struct nfs4_stid **stid)
+{
+	__be32 status;
+	struct nfs4_cpntf_state *cps = NULL;
+	struct nfs4_client *found;
+
+	status = manage_cpntf_state(nn, st, NULL, &cps);
+	if (status)
+		return status;
+
+	cps->cpntf_time = ktime_get_boottime_seconds();
+
+	status = nfserr_expired;
+	found = lookup_clientid(&cps->cp_p_clid, true, nn);
+	if (!found)
+		goto out;
+
+	*stid = find_stateid_by_type(found, &cps->cp_p_stateid,
+				     SC_TYPE_DELEG|SC_TYPE_OPEN|SC_TYPE_LOCK,
+				     0);
+	if (*stid)
+		status = nfs_ok;
+	else
+		status = nfserr_bad_stateid;
+
+	put_client_renew(found);
+out:
+	nfs4_put_cpntf_state(nn, cps);
+	return status;
+}
+
+void nfs4_put_cpntf_state(struct nfsd_net *nn, struct nfs4_cpntf_state *cps)
+{
+	spin_lock(&nn->s2s_cp_lock);
+	_free_cpntf_state_locked(nn, cps);
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
+/**
+ * nfs4_preprocess_stateid_op - find and prep stateid for an operation
+ * @rqstp: incoming request from client
+ * @cstate: current compound state
+ * @fhp: filehandle associated with requested stateid
+ * @stateid: stateid (provided by client)
+ * @flags: flags describing type of operation to be done
+ * @nfp: optional nfsd_file return pointer (may be NULL)
+ * @cstid: optional returned nfs4_stid pointer (may be NULL)
+ *
+ * Given info from the client, look up a nfs4_stid for the operation. On
+ * success, it returns a reference to the nfs4_stid and/or the nfsd_file
+ * associated with it.
+ */
+__be32
+nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
+		stateid_t *stateid, int flags, struct nfsd_file **nfp,
+		struct nfs4_stid **cstid)
+{
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfs4_stid *s = NULL;
+	__be32 status;
+
+	if (nfp)
+		*nfp = NULL;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
+		status = check_special_stateids(net, fhp, stateid, flags);
+		goto done;
+	}
+
+	status = nfsd4_lookup_stateid(cstate, stateid,
+				SC_TYPE_DELEG|SC_TYPE_OPEN|SC_TYPE_LOCK,
+				0, &s, nn);
+	if (status == nfserr_bad_stateid)
+		status = find_cpntf_state(nn, stateid, &s);
+	if (status)
+		return status;
+	status = nfsd4_stid_check_stateid_generation(stateid, s,
+			nfsd4_has_session(cstate));
+	if (status)
+		goto out;
+
+	switch (s->sc_type) {
+	case SC_TYPE_DELEG:
+		status = nfs4_check_delegmode(delegstateid(s), flags);
+		break;
+	case SC_TYPE_OPEN:
+	case SC_TYPE_LOCK:
+		status = nfs4_check_olstateid(openlockstateid(s), flags);
+		break;
+	}
+	if (status)
+		goto out;
+	status = nfs4_check_fh(fhp, s);
+
+done:
+	if (status == nfs_ok && nfp)
+		status = nfs4_check_file(rqstp, fhp, s, nfp, flags);
+out:
+	if (s) {
+		if (!status && cstid)
+			*cstid = s;
+		else
+			nfs4_put_stid(s);
+	}
+	return status;
+}
+
+/*
+ * Test if the stateid is valid
+ */
+__be32
+nfsd4_test_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct nfsd4_test_stateid_id *stateid;
+	struct nfs4_client *cl = cstate->clp;
+
+	list_for_each_entry(stateid, &test_stateid->ts_stateid_list, ts_id_list)
+		stateid->ts_id_status =
+			nfsd4_validate_stateid(cl, &stateid->ts_id_stateid);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_free_lock_stateid(stateid_t *stateid, struct nfs4_stid *s)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(s);
+	__be32 ret;
+
+	ret = nfsd4_lock_ol_stateid(stp);
+	if (ret)
+		goto out_put_stid;
+
+	ret = check_stateid_generation(stateid, &s->sc_stateid, 1);
+	if (ret)
+		goto out;
+
+	ret = nfserr_locks_held;
+	if (check_for_locks(stp->st_stid.sc_file,
+			    lockowner(stp->st_stateowner)))
+		goto out;
+
+	release_lock_stateid(stp);
+	ret = nfs_ok;
+
+out:
+	mutex_unlock(&stp->st_mutex);
+out_put_stid:
+	nfs4_put_stid(s);
+	return ret;
+}
+
+__be32
+nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
+	stateid_t *stateid = &free_stateid->fr_stateid;
+	struct nfs4_stid *s;
+	struct nfs4_delegation *dp;
+	struct nfs4_client *cl = cstate->clp;
+	__be32 ret = nfserr_bad_stateid;
+
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, stateid);
+	if (!s || s->sc_status & SC_STATUS_CLOSED)
+		goto out_unlock;
+	if (s->sc_status & SC_STATUS_ADMIN_REVOKED) {
+		nfsd4_drop_revoked_stid(s);
+		ret = nfs_ok;
+		goto out;
+	}
+	spin_lock(&s->sc_lock);
+	switch (s->sc_type) {
+	case SC_TYPE_DELEG:
+		if (s->sc_status & SC_STATUS_REVOKED) {
+			s->sc_status |= SC_STATUS_CLOSED;
+			spin_unlock(&s->sc_lock);
+			dp = delegstateid(s);
+			if (s->sc_status & SC_STATUS_FREEABLE)
+				list_del_init(&dp->dl_recall_lru);
+			s->sc_status |= SC_STATUS_FREED;
+			spin_unlock(&cl->cl_lock);
+			nfs4_put_stid(s);
+			ret = nfs_ok;
+			goto out;
+		}
+		ret = nfserr_locks_held;
+		break;
+	case SC_TYPE_OPEN:
+		ret = check_stateid_generation(stateid, &s->sc_stateid, 1);
+		if (ret)
+			break;
+		ret = nfserr_locks_held;
+		break;
+	case SC_TYPE_LOCK:
+		spin_unlock(&s->sc_lock);
+		refcount_inc(&s->sc_count);
+		spin_unlock(&cl->cl_lock);
+		ret = nfsd4_free_lock_stateid(stateid, s);
+		goto out;
+	}
+	spin_unlock(&s->sc_lock);
+out_unlock:
+	spin_unlock(&cl->cl_lock);
+out:
+	return ret;
+}
+
+static inline int
+setlkflg (int type)
+{
+	return (type == NFS4_READW_LT || type == NFS4_READ_LT) ?
+		RD_STATE : WR_STATE;
+}
+
+static __be32 nfs4_seqid_op_checks(struct nfsd4_compound_state *cstate, stateid_t *stateid, u32 seqid, struct nfs4_ol_stateid *stp)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	struct nfs4_stateowner *sop = stp->st_stateowner;
+	__be32 status;
+
+	status = nfsd4_check_seqid(cstate, sop, seqid);
+	if (status)
+		return status;
+	status = nfsd4_lock_ol_stateid(stp);
+	if (status != nfs_ok)
+		return status;
+	status = check_stateid_generation(stateid, &stp->st_stid.sc_stateid, nfsd4_has_session(cstate));
+	if (status == nfs_ok)
+		status = nfs4_check_fh(current_fh, &stp->st_stid);
+	if (status != nfs_ok)
+		mutex_unlock(&stp->st_mutex);
+	return status;
+}
+
+/**
+ * nfs4_preprocess_seqid_op - find and prep an ol_stateid for a seqid-morphing op
+ * @cstate: compund state
+ * @seqid: seqid (provided by client)
+ * @stateid: stateid (provided by client)
+ * @typemask: mask of allowable types for this operation
+ * @statusmask: mask of allowed states: 0 or STID_CLOSED
+ * @stpp: return pointer for the stateid found
+ * @nn: net namespace for request
+ *
+ * Given a stateid+seqid from a client, look up an nfs4_ol_stateid and
+ * return it in @stpp. On a nfs_ok return, the returned stateid will
+ * have its st_mutex locked.
+ */
+static __be32
+nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
+			 stateid_t *stateid,
+			 unsigned short typemask, unsigned short statusmask,
+			 struct nfs4_ol_stateid **stpp,
+			 struct nfsd_net *nn)
+{
+	__be32 status;
+	struct nfs4_stid *s;
+	struct nfs4_ol_stateid *stp = NULL;
+
+	trace_nfsd_preprocess(seqid, stateid);
+
+	*stpp = NULL;
+retry:
+	status = nfsd4_lookup_stateid(cstate, stateid,
+				      typemask, statusmask, &s, nn);
+	if (status)
+		return status;
+	stp = openlockstateid(s);
+	if (nfsd4_cstate_assign_replay(cstate, stp->st_stateowner) == -EAGAIN) {
+		nfs4_put_stid(&stp->st_stid);
+		goto retry;
+	}
+
+	status = nfs4_seqid_op_checks(cstate, stateid, seqid, stp);
+	if (!status)
+		*stpp = stp;
+	else
+		nfs4_put_stid(&stp->st_stid);
+	return status;
+}
+
+static __be32 nfs4_preprocess_confirmed_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
+						 stateid_t *stateid, struct nfs4_ol_stateid **stpp, struct nfsd_net *nn)
+{
+	__be32 status;
+	struct nfs4_openowner *oo;
+	struct nfs4_ol_stateid *stp;
+
+	status = nfs4_preprocess_seqid_op(cstate, seqid, stateid,
+					  SC_TYPE_OPEN, 0, &stp, nn);
+	if (status)
+		return status;
+	oo = openowner(stp->st_stateowner);
+	if (!(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+		mutex_unlock(&stp->st_mutex);
+		nfs4_put_stid(&stp->st_stid);
+		return nfserr_bad_stateid;
+	}
+	*stpp = stp;
+	return nfs_ok;
+}
+
+__be32
+nfsd4_open_confirm(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *oc = &u->open_confirm;
+	__be32 status;
+	struct nfs4_openowner *oo;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_open_confirm on file %pd\n",
+			cstate->current_fh.fh_dentry);
+
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0);
+	if (status)
+		return status;
+
+	status = nfs4_preprocess_seqid_op(cstate,
+					  oc->oc_seqid, &oc->oc_req_stateid,
+					  SC_TYPE_OPEN, 0, &stp, nn);
+	if (status)
+		goto out;
+	oo = openowner(stp->st_stateowner);
+	status = nfserr_bad_stateid;
+	if (oo->oo_flags & NFS4_OO_CONFIRMED) {
+		mutex_unlock(&stp->st_mutex);
+		goto put_stateid;
+	}
+	oo->oo_flags |= NFS4_OO_CONFIRMED;
+	nfs4_inc_and_copy_stateid(&oc->oc_resp_stateid, &stp->st_stid);
+	mutex_unlock(&stp->st_mutex);
+	trace_nfsd_open_confirm(oc->oc_seqid, &stp->st_stid.sc_stateid);
+	nfsd4_client_record_create(oo->oo_owner.so_client);
+	status = nfs_ok;
+put_stateid:
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	return status;
+}
+
+static inline void nfs4_stateid_downgrade_bit(struct nfs4_ol_stateid *stp, u32 access)
+{
+	if (!test_access(access, stp))
+		return;
+	nfs4_file_put_access(stp->st_stid.sc_file, access);
+	clear_access(access, stp);
+}
+
+static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_access)
+{
+	switch (to_access) {
+	case NFS4_SHARE_ACCESS_READ:
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_WRITE);
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+		break;
+	case NFS4_SHARE_ACCESS_WRITE:
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_READ);
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+		break;
+	case NFS4_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+}
+
+__be32
+nfsd4_open_downgrade(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *od = &u->open_downgrade;
+	__be32 status;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_open_downgrade on file %pd\n", 
+			cstate->current_fh.fh_dentry);
+
+	/* We don't yet support WANT bits: */
+	if (od->od_deleg_want)
+		dprintk("NFSD: %s: od_deleg_want=0x%x ignored\n", __func__,
+			od->od_deleg_want);
+
+	status = nfs4_preprocess_confirmed_seqid_op(cstate, od->od_seqid,
+					&od->od_stateid, &stp, nn);
+	if (status)
+		goto out; 
+	status = nfserr_inval;
+	if (!test_access(od->od_share_access, stp)) {
+		dprintk("NFSD: access not a subset of current bitmap: 0x%hhx, input access=%08x\n",
+			stp->st_access_bmap, od->od_share_access);
+		goto put_stateid;
+	}
+	if (!test_deny(od->od_share_deny, stp)) {
+		dprintk("NFSD: deny not a subset of current bitmap: 0x%hhx, input deny=%08x\n",
+			stp->st_deny_bmap, od->od_share_deny);
+		goto put_stateid;
+	}
+	nfs4_stateid_downgrade(stp, od->od_share_access);
+	reset_union_bmap_deny(od->od_share_deny, stp);
+	nfs4_inc_and_copy_stateid(&od->od_stateid, &stp->st_stid);
+	status = nfs_ok;
+put_stateid:
+	mutex_unlock(&stp->st_mutex);
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	return status;
+}
+
+static bool nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
+{
+	struct nfs4_client *clp = s->st_stid.sc_client;
+	bool unhashed;
+	LIST_HEAD(reaplist);
+	struct nfs4_ol_stateid *stp;
+
+	spin_lock(&clp->cl_lock);
+	unhashed = unhash_open_stateid(s, &reaplist);
+
+	if (clp->cl_minorversion) {
+		if (unhashed)
+			put_ol_stateid_locked(s, &reaplist);
+		spin_unlock(&clp->cl_lock);
+		list_for_each_entry(stp, &reaplist, st_locks)
+			nfs4_free_cpntf_statelist(clp->net, &stp->st_stid);
+		free_ol_stateid_reaplist(&reaplist);
+		return false;
+	} else {
+		spin_unlock(&clp->cl_lock);
+		free_ol_stateid_reaplist(&reaplist);
+		return unhashed;
+	}
+}
+
+/*
+ * nfs4_unlock_state() called after encode
+ */
+__be32
+nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	__be32 status;
+	struct nfs4_ol_stateid *stp;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	bool need_move_to_close_list;
+
+	dprintk("NFSD: nfsd4_close on file %pd\n",
+			cstate->current_fh.fh_dentry);
+
+	status = nfs4_preprocess_seqid_op(cstate, close->cl_seqid,
+					  &close->cl_stateid,
+					  SC_TYPE_OPEN, SC_STATUS_CLOSED,
+					  &stp, nn);
+	nfsd4_bump_seqid(cstate, status);
+	if (status)
+		goto out;
+
+	spin_lock(&stp->st_stid.sc_client->cl_lock);
+	stp->st_stid.sc_status |= SC_STATUS_CLOSED;
+	spin_unlock(&stp->st_stid.sc_client->cl_lock);
+
+	/*
+	 * Technically we don't _really_ have to increment or copy it, since
+	 * it should just be gone after this operation and we clobber the
+	 * copied value below, but we continue to do so here just to ensure
+	 * that racing ops see that there was a state change.
+	 */
+	nfs4_inc_and_copy_stateid(&close->cl_stateid, &stp->st_stid);
+
+	need_move_to_close_list = nfsd4_close_open_stateid(stp);
+	mutex_unlock(&stp->st_mutex);
+	if (need_move_to_close_list)
+		move_to_close_lru(stp, net);
+
+	/* v4.1+ suggests that we send a special stateid in here, since the
+	 * clients should just ignore this anyway. Since this is not useful
+	 * for v4.0 clients either, we set it to the special close_stateid
+	 * universally.
+	 *
+	 * See RFC5661 section 18.2.4, and RFC7530 section 16.2.5
+	 */
+	memcpy(&close->cl_stateid, &close_stateid, sizeof(close->cl_stateid));
+
+	/* put reference from nfs4_preprocess_seqid_op */
+	nfs4_put_stid(&stp->st_stid);
+out:
+	return status;
+}
+
+__be32
+nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_delegreturn *dr = &u->delegreturn;
+	struct nfs4_delegation *dp;
+	stateid_t *stateid = &dr->dr_stateid;
+	struct nfs4_stid *s;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	status = fh_verify(rqstp, &cstate->current_fh, 0, 0);
+	if (status)
+		return status;
+
+	status = nfsd4_lookup_stateid(cstate, stateid, SC_TYPE_DELEG, SC_STATUS_REVOKED, &s, nn);
+	if (status)
+		goto out;
+	dp = delegstateid(s);
+	status = nfsd4_stid_check_stateid_generation(stateid, &dp->dl_stid, nfsd4_has_session(cstate));
+	if (status)
+		goto put_stateid;
+
+	status = nfs4_check_fh(&cstate->current_fh, &dp->dl_stid);
+	if (status)
+		goto put_stateid;
+
+	trace_nfsd_deleg_return(stateid);
+	destroy_delegation(dp);
+	smp_mb__after_atomic();
+	wake_up_var(d_inode(cstate->current_fh.fh_dentry));
+put_stateid:
+	nfs4_put_stid(&dp->dl_stid);
+out:
+	return status;
+}
+
+/* last octet in a range */
+static inline u64
+last_byte_offset(u64 start, u64 len)
+{
+	u64 end;
+
+	WARN_ON_ONCE(!len);
+	end = start + len;
+	return end > start ? end - 1: NFS4_MAX_UINT64;
+}
+
+/*
+ * TODO: Linux file offsets are _signed_ 64-bit quantities, which means that
+ * we can't properly handle lock requests that go beyond the (2^63 - 1)-th
+ * byte, because of sign extension problems.  Since NFSv4 calls for 64-bit
+ * locking, this prevents us from being completely protocol-compliant.  The
+ * real solution to this problem is to start using unsigned file offsets in
+ * the VFS, but this is a very deep change!
+ */
+static inline void
+nfs4_transform_lock_offset(struct file_lock *lock)
+{
+	if (lock->fl_start < 0)
+		lock->fl_start = OFFSET_MAX;
+	if (lock->fl_end < 0)
+		lock->fl_end = OFFSET_MAX;
+}
+
+static fl_owner_t
+nfsd4_lm_get_owner(fl_owner_t owner)
+{
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)owner;
+
+	nfs4_get_stateowner(&lo->lo_owner);
+	return owner;
+}
+
+static void
+nfsd4_lm_put_owner(fl_owner_t owner)
+{
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)owner;
+
+	if (lo)
+		nfs4_put_stateowner(&lo->lo_owner);
+}
+
+/* return pointer to struct nfs4_client if client is expirable */
+static bool
+nfsd4_lm_lock_expirable(struct file_lock *cfl)
+{
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *) cfl->c.flc_owner;
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+	struct nfsd_net *nn;
+
+	if (try_to_expire_client(clp)) {
+		nn = net_generic(clp->net, nfsd_net_id);
+		mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+		return true;
+	}
+	return false;
+}
+
+/* schedule laundromat to run immediately and wait for it to complete */
+static void
+nfsd4_lm_expire_lock(void)
+{
+	flush_workqueue(laundry_wq);
+}
+
+static void
+nfsd4_lm_notify(struct file_lock *fl)
+{
+	struct nfs4_lockowner		*lo = (struct nfs4_lockowner *) fl->c.flc_owner;
+	struct net			*net = lo->lo_owner.so_client->net;
+	struct nfsd_net			*nn = net_generic(net, nfsd_net_id);
+	struct nfsd4_blocked_lock	*nbl = container_of(fl,
+						struct nfsd4_blocked_lock, nbl_lock);
+	bool queue = false;
+
+	/* An empty list means that something else is going to be using it */
+	spin_lock(&nn->blocked_locks_lock);
+	if (!list_empty(&nbl->nbl_list)) {
+		list_del_init(&nbl->nbl_list);
+		list_del_init(&nbl->nbl_lru);
+		queue = true;
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+
+	if (queue) {
+		trace_nfsd_cb_notify_lock(lo, nbl);
+		nfsd4_try_run_cb(&nbl->nbl_cb);
+	}
+}
+
+static const struct lock_manager_operations nfsd_posix_mng_ops  = {
+	.lm_mod_owner = THIS_MODULE,
+	.lm_notify = nfsd4_lm_notify,
+	.lm_get_owner = nfsd4_lm_get_owner,
+	.lm_put_owner = nfsd4_lm_put_owner,
+	.lm_lock_expirable = nfsd4_lm_lock_expirable,
+	.lm_expire_lock = nfsd4_lm_expire_lock,
+};
+
+static inline void
+nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
+{
+	struct nfs4_lockowner *lo;
+
+	if (fl->fl_lmops == &nfsd_posix_mng_ops) {
+		lo = (struct nfs4_lockowner *) fl->c.flc_owner;
+		xdr_netobj_dup(&deny->ld_owner, &lo->lo_owner.so_owner,
+						GFP_KERNEL);
+		if (!deny->ld_owner.data)
+			/* We just don't care that much */
+			goto nevermind;
+		deny->ld_clientid = lo->lo_owner.so_client->cl_clientid;
+	} else {
+nevermind:
+		deny->ld_owner.len = 0;
+		deny->ld_owner.data = NULL;
+		deny->ld_clientid.cl_boot = 0;
+		deny->ld_clientid.cl_id = 0;
+	}
+	deny->ld_start = fl->fl_start;
+	deny->ld_length = NFS4_MAX_UINT64;
+	if (fl->fl_end != NFS4_MAX_UINT64)
+		deny->ld_length = fl->fl_end - fl->fl_start + 1;        
+	deny->ld_type = NFS4_READ_LT;
+	if (fl->c.flc_type != F_RDLCK)
+		deny->ld_type = NFS4_WRITE_LT;
+}
+
+static struct nfs4_lockowner *
+find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
+{
+	unsigned int strhashval = ownerstr_hashval(owner);
+	struct nfs4_stateowner *so;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[strhashval],
+			    so_strhash) {
+		if (so->so_is_open_owner)
+			continue;
+		if (same_owner_str(so, owner))
+			return lockowner(nfs4_get_stateowner(so));
+	}
+	return NULL;
+}
+
+static struct nfs4_lockowner *
+find_lockowner_str(struct nfs4_client *clp, struct xdr_netobj *owner)
+{
+	struct nfs4_lockowner *lo;
+
+	spin_lock(&clp->cl_lock);
+	lo = find_lockowner_str_locked(clp, owner);
+	spin_unlock(&clp->cl_lock);
+	return lo;
+}
+
+static void nfs4_unhash_lockowner(struct nfs4_stateowner *sop)
+{
+	unhash_lockowner_locked(lockowner(sop));
+}
+
+static void nfs4_free_lockowner(struct nfs4_stateowner *sop)
+{
+	struct nfs4_lockowner *lo = lockowner(sop);
+
+	kmem_cache_free(lockowner_slab, lo);
+}
+
+static const struct nfs4_stateowner_operations lockowner_ops = {
+	.so_unhash =	nfs4_unhash_lockowner,
+	.so_free =	nfs4_free_lockowner,
+};
+
+/*
+ * Alloc a lock owner structure.
+ * Called in nfsd4_lock - therefore, OPEN and OPEN_CONFIRM (if needed) has 
+ * occurred. 
+ *
+ * strhashval = ownerstr_hashval
+ */
+static struct nfs4_lockowner *
+alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp,
+			   struct nfs4_ol_stateid *open_stp,
+			   struct nfsd4_lock *lock)
+{
+	struct nfs4_lockowner *lo, *ret;
+
+	lo = alloc_stateowner(lockowner_slab, &lock->lk_new_owner, clp);
+	if (!lo)
+		return NULL;
+	INIT_LIST_HEAD(&lo->lo_blocked);
+	INIT_LIST_HEAD(&lo->lo_owner.so_stateids);
+	lo->lo_owner.so_is_open_owner = 0;
+	lo->lo_owner.so_seqid = lock->lk_new_lock_seqid;
+	lo->lo_owner.so_ops = &lockowner_ops;
+	spin_lock(&clp->cl_lock);
+	ret = find_lockowner_str_locked(clp, &lock->lk_new_owner);
+	if (ret == NULL) {
+		list_add(&lo->lo_owner.so_strhash,
+			 &clp->cl_ownerstr_hashtbl[strhashval]);
+		ret = lo;
+	} else
+		nfs4_free_stateowner(&lo->lo_owner);
+
+	spin_unlock(&clp->cl_lock);
+	return ret;
+}
+
+static struct nfs4_ol_stateid *
+find_lock_stateid(const struct nfs4_lockowner *lo,
+		  const struct nfs4_ol_stateid *ost)
+{
+	struct nfs4_ol_stateid *lst;
+
+	lockdep_assert_held(&ost->st_stid.sc_client->cl_lock);
+
+	/* If ost is not hashed, ost->st_locks will not be valid */
+	if (!nfs4_ol_stateid_unhashed(ost))
+		list_for_each_entry(lst, &ost->st_locks, st_locks) {
+			if (lst->st_stateowner == &lo->lo_owner) {
+				refcount_inc(&lst->st_stid.sc_count);
+				return lst;
+			}
+		}
+	return NULL;
+}
+
+static struct nfs4_ol_stateid *
+init_lock_stateid(struct nfs4_ol_stateid *stp, struct nfs4_lockowner *lo,
+		  struct nfs4_file *fp, struct inode *inode,
+		  struct nfs4_ol_stateid *open_stp)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+	struct nfs4_ol_stateid *retstp;
+
+	mutex_init(&stp->st_mutex);
+	mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX);
+retry:
+	spin_lock(&clp->cl_lock);
+	if (nfs4_ol_stateid_unhashed(open_stp))
+		goto out_close;
+	retstp = find_lock_stateid(lo, open_stp);
+	if (retstp)
+		goto out_found;
+	refcount_inc(&stp->st_stid.sc_count);
+	stp->st_stid.sc_type = SC_TYPE_LOCK;
+	stp->st_stateowner = nfs4_get_stateowner(&lo->lo_owner);
+	get_nfs4_file(fp);
+	stp->st_stid.sc_file = fp;
+	if (open_stp->st_stid.sc_export)
+		stp->st_stid.sc_export =
+			exp_get(open_stp->st_stid.sc_export);
+	stp->st_access_bmap = 0;
+	stp->st_deny_bmap = open_stp->st_deny_bmap;
+	stp->st_openstp = open_stp;
+	spin_lock(&fp->fi_lock);
+	list_add(&stp->st_locks, &open_stp->st_locks);
+	list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids);
+	list_add(&stp->st_perfile, &fp->fi_stateids);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&clp->cl_lock);
+	return stp;
+out_found:
+	spin_unlock(&clp->cl_lock);
+	if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) {
+		nfs4_put_stid(&retstp->st_stid);
+		goto retry;
+	}
+	/* To keep mutex tracking happy */
+	mutex_unlock(&stp->st_mutex);
+	return retstp;
+out_close:
+	spin_unlock(&clp->cl_lock);
+	mutex_unlock(&stp->st_mutex);
+	return NULL;
+}
+
+static struct nfs4_ol_stateid *
+find_or_create_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fi,
+			    struct inode *inode, struct nfs4_ol_stateid *ost,
+			    bool *new)
+{
+	struct nfs4_stid *ns = NULL;
+	struct nfs4_ol_stateid *lst;
+	struct nfs4_openowner *oo = openowner(ost->st_stateowner);
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+
+	*new = false;
+	spin_lock(&clp->cl_lock);
+	lst = find_lock_stateid(lo, ost);
+	spin_unlock(&clp->cl_lock);
+	if (lst != NULL) {
+		if (nfsd4_lock_ol_stateid(lst) == nfs_ok)
+			goto out;
+		nfs4_put_stid(&lst->st_stid);
+	}
+	ns = nfs4_alloc_stid(clp, stateid_slab, nfs4_free_lock_stateid);
+	if (ns == NULL)
+		return NULL;
+
+	lst = init_lock_stateid(openlockstateid(ns), lo, fi, inode, ost);
+	if (lst == openlockstateid(ns))
+		*new = true;
+	else
+		nfs4_put_stid(ns);
+out:
+	return lst;
+}
+
+static int
+check_lock_length(u64 offset, u64 length)
+{
+	return ((length == 0) || ((length != NFS4_MAX_UINT64) &&
+		(length > ~offset)));
+}
+
+static void get_lock_access(struct nfs4_ol_stateid *lock_stp, u32 access)
+{
+	struct nfs4_file *fp = lock_stp->st_stid.sc_file;
+
+	lockdep_assert_held(&fp->fi_lock);
+
+	if (test_access(access, lock_stp))
+		return;
+	__nfs4_file_get_access(fp, access);
+	set_access(access, lock_stp);
+}
+
+static __be32
+lookup_or_create_lock_state(struct nfsd4_compound_state *cstate,
+			    struct nfs4_ol_stateid *ost,
+			    struct nfsd4_lock *lock,
+			    struct nfs4_ol_stateid **plst, bool *new)
+{
+	__be32 status;
+	struct nfs4_file *fi = ost->st_stid.sc_file;
+	struct nfs4_openowner *oo = openowner(ost->st_stateowner);
+	struct nfs4_client *cl = oo->oo_owner.so_client;
+	struct inode *inode = d_inode(cstate->current_fh.fh_dentry);
+	struct nfs4_lockowner *lo;
+	struct nfs4_ol_stateid *lst;
+	unsigned int strhashval;
+
+	lo = find_lockowner_str(cl, &lock->lk_new_owner);
+	if (!lo) {
+		strhashval = ownerstr_hashval(&lock->lk_new_owner);
+		lo = alloc_init_lock_stateowner(strhashval, cl, ost, lock);
+		if (lo == NULL)
+			return nfserr_jukebox;
+	} else {
+		/* with an existing lockowner, seqids must be the same */
+		status = nfserr_bad_seqid;
+		if (!cstate->minorversion &&
+		    lock->lk_new_lock_seqid != lo->lo_owner.so_seqid)
+			goto out;
+	}
+
+	lst = find_or_create_lock_stateid(lo, fi, inode, ost, new);
+	if (lst == NULL) {
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	status = nfs_ok;
+	*plst = lst;
+out:
+	nfs4_put_stateowner(&lo->lo_owner);
+	return status;
+}
+
+/*
+ *  LOCK operation 
+ */
+__be32
+nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	struct nfs4_openowner *open_sop = NULL;
+	struct nfs4_lockowner *lock_sop = NULL;
+	struct nfs4_ol_stateid *lock_stp = NULL;
+	struct nfs4_ol_stateid *open_stp = NULL;
+	struct nfs4_file *fp;
+	struct nfsd_file *nf = NULL;
+	struct nfsd4_blocked_lock *nbl = NULL;
+	struct file_lock *file_lock = NULL;
+	struct file_lock *conflock = NULL;
+	__be32 status = 0;
+	int lkflg;
+	int err;
+	bool new = false;
+	unsigned char type;
+	unsigned int flags = FL_POSIX;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
+		(long long) lock->lk_offset,
+		(long long) lock->lk_length);
+
+	if (check_lock_length(lock->lk_offset, lock->lk_length))
+		 return nfserr_inval;
+
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0);
+	if (status != nfs_ok)
+		return status;
+	if (exportfs_cannot_lock(cstate->current_fh.fh_dentry->d_sb->s_export_op)) {
+		status = nfserr_notsupp;
+		goto out;
+	}
+
+	if (lock->lk_is_new) {
+		if (nfsd4_has_session(cstate))
+			/* See rfc 5661 18.10.3: given clientid is ignored: */
+			memcpy(&lock->lk_new_clientid,
+				&cstate->clp->cl_clientid,
+				sizeof(clientid_t));
+
+		/* validate and update open stateid and open seqid */
+		status = nfs4_preprocess_confirmed_seqid_op(cstate,
+				        lock->lk_new_open_seqid,
+		                        &lock->lk_new_open_stateid,
+					&open_stp, nn);
+		if (status)
+			goto out;
+		mutex_unlock(&open_stp->st_mutex);
+		open_sop = openowner(open_stp->st_stateowner);
+		status = nfserr_bad_stateid;
+		if (!same_clid(&open_sop->oo_owner.so_client->cl_clientid,
+						&lock->lk_new_clientid))
+			goto out;
+		status = lookup_or_create_lock_state(cstate, open_stp, lock,
+							&lock_stp, &new);
+	} else {
+		status = nfs4_preprocess_seqid_op(cstate,
+						  lock->lk_old_lock_seqid,
+						  &lock->lk_old_lock_stateid,
+						  SC_TYPE_LOCK, 0, &lock_stp,
+						  nn);
+	}
+	if (status)
+		goto out;
+	lock_sop = lockowner(lock_stp->st_stateowner);
+
+	lkflg = setlkflg(lock->lk_type);
+	status = nfs4_check_openmode(lock_stp, lkflg);
+	if (status)
+		goto out;
+
+	status = nfserr_grace;
+	if (locks_in_grace(net) && !lock->lk_reclaim)
+		goto out;
+	status = nfserr_no_grace;
+	if (!locks_in_grace(net) && lock->lk_reclaim)
+		goto out;
+	if (lock->lk_reclaim &&
+	    test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &cstate->clp->cl_flags))
+		goto out;
+
+	if (lock->lk_reclaim)
+		flags |= FL_RECLAIM;
+
+	fp = lock_stp->st_stid.sc_file;
+	switch (lock->lk_type) {
+		case NFS4_READW_LT:
+			fallthrough;
+		case NFS4_READ_LT:
+			spin_lock(&fp->fi_lock);
+			nf = find_readable_file_locked(fp);
+			if (nf)
+				get_lock_access(lock_stp, NFS4_SHARE_ACCESS_READ);
+			spin_unlock(&fp->fi_lock);
+			type = F_RDLCK;
+			break;
+		case NFS4_WRITEW_LT:
+			fallthrough;
+		case NFS4_WRITE_LT:
+			spin_lock(&fp->fi_lock);
+			nf = find_writeable_file_locked(fp);
+			if (nf)
+				get_lock_access(lock_stp, NFS4_SHARE_ACCESS_WRITE);
+			spin_unlock(&fp->fi_lock);
+			type = F_WRLCK;
+			break;
+		default:
+			status = nfserr_inval;
+		goto out;
+	}
+
+	if (!nf) {
+		status = nfserr_openmode;
+		goto out;
+	}
+
+	if ((lock->lk_type == NFS4_READW_LT ||
+	     lock->lk_type == NFS4_WRITEW_LT) &&
+	    nfsd4_has_session(cstate) &&
+	    locks_can_async_lock(nf->nf_file->f_op))
+		flags |= FL_SLEEP;
+
+	nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn);
+	if (!nbl) {
+		dprintk("NFSD: %s: unable to allocate block!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	file_lock = &nbl->nbl_lock;
+	file_lock->c.flc_type = type;
+	file_lock->c.flc_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(&lock_sop->lo_owner));
+	file_lock->c.flc_pid = current->tgid;
+	file_lock->c.flc_file = nf->nf_file;
+	file_lock->c.flc_flags = flags;
+	file_lock->fl_lmops = &nfsd_posix_mng_ops;
+	file_lock->fl_start = lock->lk_offset;
+	file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
+	nfs4_transform_lock_offset(file_lock);
+
+	conflock = locks_alloc_lock();
+	if (!conflock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	if (flags & FL_SLEEP) {
+		nbl->nbl_time = ktime_get_boottime_seconds();
+		spin_lock(&nn->blocked_locks_lock);
+		list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked);
+		list_add_tail(&nbl->nbl_lru, &nn->blocked_locks_lru);
+		kref_get(&nbl->nbl_kref);
+		spin_unlock(&nn->blocked_locks_lock);
+	}
+
+	err = vfs_lock_file(nf->nf_file, F_SETLK, file_lock, conflock);
+	switch (err) {
+	case 0: /* success! */
+		nfs4_inc_and_copy_stateid(&lock->lk_resp_stateid, &lock_stp->st_stid);
+		status = 0;
+		if (lock->lk_reclaim)
+			set_bit(NFSD_NET_SOMEBODY_RECLAIMED, &nn->flags);
+		break;
+	case FILE_LOCK_DEFERRED:
+		kref_put(&nbl->nbl_kref, free_nbl);
+		nbl = NULL;
+		fallthrough;
+	case -EAGAIN:		/* conflock holds conflicting lock */
+		status = nfserr_denied;
+		dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
+		nfs4_set_lock_denied(conflock, &lock->lk_denied);
+		break;
+	case -EDEADLK:
+		status = nfserr_deadlock;
+		break;
+	default:
+		dprintk("NFSD: nfsd4_lock: vfs_lock_file() failed! status %d\n",err);
+		status = nfserrno(err);
+		break;
+	}
+out:
+	if (nbl) {
+		/* dequeue it if we queued it before */
+		if (flags & FL_SLEEP) {
+			spin_lock(&nn->blocked_locks_lock);
+			if (!list_empty(&nbl->nbl_list) &&
+			    !list_empty(&nbl->nbl_lru)) {
+				list_del_init(&nbl->nbl_list);
+				list_del_init(&nbl->nbl_lru);
+				kref_put(&nbl->nbl_kref, free_nbl);
+			}
+			/* nbl can use one of lists to be linked to reaplist */
+			spin_unlock(&nn->blocked_locks_lock);
+		}
+		free_blocked_lock(nbl);
+	}
+	if (nf)
+		nfsd_file_put(nf);
+	if (lock_stp) {
+		/* Bump seqid manually if the 4.0 replay owner is openowner */
+		if (cstate->replay_owner &&
+		    cstate->replay_owner != &lock_sop->lo_owner &&
+		    seqid_mutating_err(ntohl(status)))
+			lock_sop->lo_owner.so_seqid++;
+
+		/*
+		 * If this is a new, never-before-used stateid, and we are
+		 * returning an error, then just go ahead and release it.
+		 */
+		if (status && new)
+			release_lock_stateid(lock_stp);
+
+		mutex_unlock(&lock_stp->st_mutex);
+
+		nfs4_put_stid(&lock_stp->st_stid);
+	}
+	if (open_stp)
+		nfs4_put_stid(&open_stp->st_stid);
+	nfsd4_bump_seqid(cstate, status);
+	if (conflock)
+		locks_free_lock(conflock);
+	return status;
+}
+
+void nfsd4_lock_release(union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	struct nfsd4_lock_denied *deny = &lock->lk_denied;
+
+	kfree(deny->ld_owner.data);
+}
+
+/*
+ * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
+ * so we do a temporary open here just to get an open file to pass to
+ * vfs_test_lock.
+ */
+static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
+{
+	struct nfsd_file *nf;
+	struct inode *inode;
+	__be32 err;
+
+	err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
+	if (err)
+		return err;
+	inode = fhp->fh_dentry->d_inode;
+	inode_lock(inode); /* to block new leases till after test_lock: */
+	err = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
+	if (err)
+		goto out;
+	lock->c.flc_file = nf->nf_file;
+	err = nfserrno(vfs_test_lock(nf->nf_file, lock));
+	lock->c.flc_file = NULL;
+out:
+	inode_unlock(inode);
+	nfsd_file_put(nf);
+	return err;
+}
+
+/*
+ * LOCKT operation
+ */
+__be32
+nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	struct file_lock *file_lock = NULL;
+	struct nfs4_lockowner *lo = NULL;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (locks_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	if (check_lock_length(lockt->lt_offset, lockt->lt_length))
+		 return nfserr_inval;
+
+	if (!nfsd4_has_session(cstate)) {
+		status = set_client(&lockt->lt_clientid, cstate, nn);
+		if (status)
+			goto out;
+	}
+
+	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
+		goto out;
+
+	file_lock = locks_alloc_lock();
+	if (!file_lock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	switch (lockt->lt_type) {
+		case NFS4_READ_LT:
+		case NFS4_READW_LT:
+			file_lock->c.flc_type = F_RDLCK;
+			break;
+		case NFS4_WRITE_LT:
+		case NFS4_WRITEW_LT:
+			file_lock->c.flc_type = F_WRLCK;
+			break;
+		default:
+			dprintk("NFSD: nfs4_lockt: bad lock type!\n");
+			status = nfserr_inval;
+			goto out;
+	}
+
+	lo = find_lockowner_str(cstate->clp, &lockt->lt_owner);
+	if (lo)
+		file_lock->c.flc_owner = (fl_owner_t)lo;
+	file_lock->c.flc_pid = current->tgid;
+	file_lock->c.flc_flags = FL_POSIX;
+
+	file_lock->fl_start = lockt->lt_offset;
+	file_lock->fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
+
+	nfs4_transform_lock_offset(file_lock);
+
+	status = nfsd_test_lock(rqstp, &cstate->current_fh, file_lock);
+	if (status)
+		goto out;
+
+	if (file_lock->c.flc_type != F_UNLCK) {
+		status = nfserr_denied;
+		nfs4_set_lock_denied(file_lock, &lockt->lt_denied);
+	}
+out:
+	if (lo)
+		nfs4_put_stateowner(&lo->lo_owner);
+	if (file_lock)
+		locks_free_lock(file_lock);
+	return status;
+}
+
+void nfsd4_lockt_release(union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	struct nfsd4_lock_denied *deny = &lockt->lt_denied;
+
+	kfree(deny->ld_owner.data);
+}
+
+__be32
+nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_file *nf = NULL;
+	struct file_lock *file_lock = NULL;
+	__be32 status;
+	int err;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_locku: start=%Ld length=%Ld\n",
+		(long long) locku->lu_offset,
+		(long long) locku->lu_length);
+
+	if (check_lock_length(locku->lu_offset, locku->lu_length))
+		 return nfserr_inval;
+
+	status = nfs4_preprocess_seqid_op(cstate, locku->lu_seqid,
+					  &locku->lu_stateid, SC_TYPE_LOCK, 0,
+					  &stp, nn);
+	if (status)
+		goto out;
+	nf = find_any_file(stp->st_stid.sc_file);
+	if (!nf) {
+		status = nfserr_lock_range;
+		goto put_stateid;
+	}
+	if (exportfs_cannot_lock(nf->nf_file->f_path.mnt->mnt_sb->s_export_op)) {
+		status = nfserr_notsupp;
+		goto put_file;
+	}
+
+	file_lock = locks_alloc_lock();
+	if (!file_lock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto put_file;
+	}
+
+	file_lock->c.flc_type = F_UNLCK;
+	file_lock->c.flc_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(stp->st_stateowner));
+	file_lock->c.flc_pid = current->tgid;
+	file_lock->c.flc_file = nf->nf_file;
+	file_lock->c.flc_flags = FL_POSIX;
+	file_lock->fl_lmops = &nfsd_posix_mng_ops;
+	file_lock->fl_start = locku->lu_offset;
+
+	file_lock->fl_end = last_byte_offset(locku->lu_offset,
+						locku->lu_length);
+	nfs4_transform_lock_offset(file_lock);
+
+	err = vfs_lock_file(nf->nf_file, F_SETLK, file_lock, NULL);
+	if (err) {
+		dprintk("NFSD: nfs4_locku: vfs_lock_file failed!\n");
+		goto out_nfserr;
+	}
+	nfs4_inc_and_copy_stateid(&locku->lu_stateid, &stp->st_stid);
+put_file:
+	nfsd_file_put(nf);
+put_stateid:
+	mutex_unlock(&stp->st_mutex);
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	if (file_lock)
+		locks_free_lock(file_lock);
+	return status;
+
+out_nfserr:
+	status = nfserrno(err);
+	goto put_file;
+}
+
+/*
+ * returns
+ * 	true:  locks held by lockowner
+ * 	false: no locks held by lockowner
+ */
+static bool
+check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner)
+{
+	struct file_lock *fl;
+	int status = false;
+	struct nfsd_file *nf;
+	struct inode *inode;
+	struct file_lock_context *flctx;
+
+	spin_lock(&fp->fi_lock);
+	nf = find_any_file_locked(fp);
+	if (!nf) {
+		/* Any valid lock stateid should have some sort of access */
+		WARN_ON_ONCE(1);
+		goto out;
+	}
+
+	inode = file_inode(nf->nf_file);
+	flctx = locks_inode_context(inode);
+
+	if (flctx && !list_empty_careful(&flctx->flc_posix)) {
+		spin_lock(&flctx->flc_lock);
+		for_each_file_lock(fl, &flctx->flc_posix) {
+			if (fl->c.flc_owner == (fl_owner_t)lowner) {
+				status = true;
+				break;
+			}
+		}
+		spin_unlock(&flctx->flc_lock);
+	}
+out:
+	spin_unlock(&fp->fi_lock);
+	return status;
+}
+
+/**
+ * nfsd4_release_lockowner - process NFSv4.0 RELEASE_LOCKOWNER operations
+ * @rqstp: RPC transaction
+ * @cstate: NFSv4 COMPOUND state
+ * @u: RELEASE_LOCKOWNER arguments
+ *
+ * Check if there are any locks still held and if not, free the lockowner
+ * and any lock state that is owned.
+ *
+ * Return values:
+ *   %nfs_ok: lockowner released or not found
+ *   %nfserr_locks_held: lockowner still in use
+ *   %nfserr_stale_clientid: clientid no longer active
+ *   %nfserr_expired: clientid not recognized
+ */
+__be32
+nfsd4_release_lockowner(struct svc_rqst *rqstp,
+			struct nfsd4_compound_state *cstate,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	clientid_t *clid = &rlockowner->rl_clientid;
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_lockowner *lo;
+	struct nfs4_client *clp;
+	LIST_HEAD(reaplist);
+	__be32 status;
+
+	dprintk("nfsd4_release_lockowner clientid: (%08x/%08x):\n",
+		clid->cl_boot, clid->cl_id);
+
+	status = set_client(clid, cstate, nn);
+	if (status)
+		return status;
+	clp = cstate->clp;
+
+	spin_lock(&clp->cl_lock);
+	lo = find_lockowner_str_locked(clp, &rlockowner->rl_owner);
+	if (!lo) {
+		spin_unlock(&clp->cl_lock);
+		return nfs_ok;
+	}
+
+	list_for_each_entry(stp, &lo->lo_owner.so_stateids, st_perstateowner) {
+		if (check_for_locks(stp->st_stid.sc_file, lo)) {
+			spin_unlock(&clp->cl_lock);
+			nfs4_put_stateowner(&lo->lo_owner);
+			return nfserr_locks_held;
+		}
+	}
+	unhash_lockowner_locked(lo);
+	while (!list_empty(&lo->lo_owner.so_stateids)) {
+		stp = list_first_entry(&lo->lo_owner.so_stateids,
+				       struct nfs4_ol_stateid,
+				       st_perstateowner);
+		unhash_lock_stateid(stp);
+		put_ol_stateid_locked(stp, &reaplist);
+	}
+	spin_unlock(&clp->cl_lock);
+
+	free_ol_stateid_reaplist(&reaplist);
+	remove_blocked_locks(lo);
+	nfs4_put_stateowner(&lo->lo_owner);
+	return nfs_ok;
+}
+
+static inline struct nfs4_client_reclaim *
+alloc_reclaim(void)
+{
+	return kmalloc_obj(struct nfs4_client_reclaim);
+}
+
+bool
+nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn)
+{
+	struct nfs4_client_reclaim *crp;
+	bool found;
+
+	down_read(&nn->reclaim_str_hashtbl_lock);
+	crp = nfsd4_find_reclaim_client(name, nn);
+	found = (crp && crp->cr_clp);
+	up_read(&nn->reclaim_str_hashtbl_lock);
+	return found;
+}
+
+/*
+ * failure => all reset bets are off, nfserr_no_grace...
+ */
+struct nfs4_client_reclaim *
+nfs4_client_to_reclaim(struct xdr_netobj name, struct xdr_netobj princhash,
+		struct nfsd_net *nn)
+{
+	unsigned int strhashval;
+	struct nfs4_client_reclaim *crp;
+
+	down_write(&nn->reclaim_str_hashtbl_lock);
+
+	/*
+	 * A reclaim record for this client name may already exist (for
+	 * example, populated at boot from the recovery directory before
+	 * an in-grace RECLAIM_COMPLETE or an nfsdcld downcall delivers
+	 * the same name). Dedup here so reclaim_str_hashtbl_size stays
+	 * equal to the number of distinct client names; inc_reclaim_complete
+	 * relies on that equality to end the grace period via the fast path.
+	 */
+	crp = nfsd4_find_reclaim_client(name, nn);
+	if (crp) {
+		if (princhash.len && crp->cr_princhash.len == 0) {
+			void *pdata = kmemdup(princhash.data, princhash.len,
+					      GFP_KERNEL);
+			if (pdata) {
+				crp->cr_princhash.data = pdata;
+				crp->cr_princhash.len = princhash.len;
+			} else {
+				dprintk("%s: failed to allocate memory for princhash.data!\n",
+					__func__);
+				crp = NULL;
+			}
+		}
+		up_write(&nn->reclaim_str_hashtbl_lock);
+		return crp;
+	}
+
+	name.data = kmemdup(name.data, name.len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		up_write(&nn->reclaim_str_hashtbl_lock);
+		return NULL;
+	}
+	if (princhash.len) {
+		princhash.data = kmemdup(princhash.data, princhash.len, GFP_KERNEL);
+		if (!princhash.data) {
+			dprintk("%s: failed to allocate memory for princhash.data!\n",
+				__func__);
+			kfree(name.data);
+			up_write(&nn->reclaim_str_hashtbl_lock);
+			return NULL;
+		}
+	} else
+		princhash.data = NULL;
+	crp = alloc_reclaim();
+	if (crp) {
+		strhashval = clientstr_hashval(name);
+		INIT_LIST_HEAD(&crp->cr_strhash);
+		list_add(&crp->cr_strhash, &nn->reclaim_str_hashtbl[strhashval]);
+		crp->cr_name.data = name.data;
+		crp->cr_name.len = name.len;
+		crp->cr_princhash.data = princhash.data;
+		crp->cr_princhash.len = princhash.len;
+		crp->cr_clp = NULL;
+		nn->reclaim_str_hashtbl_size++;
+	} else {
+		kfree(name.data);
+		kfree(princhash.data);
+	}
+	up_write(&nn->reclaim_str_hashtbl_lock);
+	return crp;
+}
+
+void
+nfs4_remove_reclaim_record(struct nfs4_client_reclaim *crp, struct nfsd_net *nn)
+{
+	list_del(&crp->cr_strhash);
+	kfree(crp->cr_name.data);
+	kfree(crp->cr_princhash.data);
+	kfree(crp);
+	nn->reclaim_str_hashtbl_size--;
+}
+
+void
+nfs4_release_reclaim(struct nfsd_net *nn)
+{
+	struct nfs4_client_reclaim *crp = NULL;
+	int i;
+
+	down_write(&nn->reclaim_str_hashtbl_lock);
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->reclaim_str_hashtbl[i])) {
+			crp = list_entry(nn->reclaim_str_hashtbl[i].next,
+			                struct nfs4_client_reclaim, cr_strhash);
+			nfs4_remove_reclaim_record(crp, nn);
+		}
+	}
+	WARN_ON_ONCE(nn->reclaim_str_hashtbl_size);
+	up_write(&nn->reclaim_str_hashtbl_lock);
+}
+
+/*
+ * called from OPEN, CLAIM_PREVIOUS with a new clientid. */
+struct nfs4_client_reclaim *
+nfsd4_find_reclaim_client(struct xdr_netobj name, struct nfsd_net *nn)
+{
+	unsigned int strhashval;
+	struct nfs4_client_reclaim *crp = NULL;
+
+	strhashval = clientstr_hashval(name);
+	list_for_each_entry(crp, &nn->reclaim_str_hashtbl[strhashval], cr_strhash) {
+		if (compare_blob(&crp->cr_name, &name) == 0) {
+			return crp;
+		}
+	}
+	return NULL;
+}
+
+__be32
+nfs4_check_open_reclaim(struct nfs4_client *clp)
+{
+	if (test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &clp->cl_flags))
+		return nfserr_no_grace;
+
+	if (nfsd4_client_record_check(clp))
+		return nfserr_reclaim_bad;
+
+	return nfs_ok;
+}
+
+/*
+ * Since the lifetime of a delegation isn't limited to that of an open, a
+ * client may quite reasonably hang on to a delegation as long as it has
+ * the inode cached.  This becomes an obvious problem the first time a
+ * client's inode cache approaches the size of the server's total memory.
+ *
+ * For now we avoid this problem by imposing a hard limit on the number
+ * of delegations, which varies according to the server's memory size.
+ */
+static void
+set_max_delegations(void)
+{
+	/*
+	 * Allow at most 4 delegations per megabyte of RAM.  Quick
+	 * estimates suggest that in the worst case (where every delegation
+	 * is for a different inode), a delegation could take about 1.5K,
+	 * giving a worst case usage of about 6% of memory.
+	 */
+	max_delegations = nr_free_buffer_pages() >> (20 - 2 - PAGE_SHIFT);
+}
+
+static int nfs4_state_create_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->conf_id_hashtbl = kmalloc_objs(struct list_head, CLIENT_HASH_SIZE);
+	if (!nn->conf_id_hashtbl)
+		goto err;
+	nn->unconf_id_hashtbl = kmalloc_objs(struct list_head, CLIENT_HASH_SIZE);
+	if (!nn->unconf_id_hashtbl)
+		goto err_unconf_id;
+	nn->sessionid_hashtbl = kmalloc_objs(struct list_head,
+					     SESSION_HASH_SIZE);
+	if (!nn->sessionid_hashtbl)
+		goto err_sessionid;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		INIT_LIST_HEAD(&nn->conf_id_hashtbl[i]);
+		INIT_LIST_HEAD(&nn->unconf_id_hashtbl[i]);
+	}
+	for (i = 0; i < SESSION_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->sessionid_hashtbl[i]);
+	nn->conf_name_tree = RB_ROOT;
+	nn->unconf_name_tree = RB_ROOT;
+	nn->boot_time = ktime_get_real_seconds();
+	nn->boot_time_bt = ktime_get_boottime_seconds();
+	clear_bit(NFSD_NET_GRACE_ENDED, &nn->flags);
+	clear_bit(NFSD_NET_GRACE_END_FORCED, &nn->flags);
+	nn->nfsd4_manager.block_opens = true;
+	INIT_LIST_HEAD(&nn->nfsd4_manager.list);
+	INIT_LIST_HEAD(&nn->client_lru);
+	INIT_LIST_HEAD(&nn->close_lru);
+	INIT_LIST_HEAD(&nn->del_recall_lru);
+	spin_lock_init(&nn->deleg_lock);
+	spin_lock_init(&nn->client_lock);
+	spin_lock_init(&nn->s2s_cp_lock);
+	idr_init(&nn->s2s_cp_stateids);
+	atomic_set(&nn->pending_async_copies, 0);
+
+	spin_lock_init(&nn->blocked_locks_lock);
+	INIT_LIST_HEAD(&nn->blocked_locks_lru);
+
+	INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main);
+	/* Make sure this cannot run until client tracking is initialised */
+	disable_delayed_work(&nn->laundromat_work);
+	INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker);
+	get_net(net);
+
+	nn->nfsd_client_shrinker = shrinker_alloc(0, "nfsd-client");
+	if (!nn->nfsd_client_shrinker)
+		goto err_shrinker;
+
+	nn->nfsd_client_shrinker->scan_objects = nfsd4_state_shrinker_scan;
+	nn->nfsd_client_shrinker->count_objects = nfsd4_state_shrinker_count;
+	nn->nfsd_client_shrinker->private_data = nn;
+
+	shrinker_register(nn->nfsd_client_shrinker);
+
+	return 0;
+
+err_shrinker:
+	put_net(net);
+	kfree(nn->sessionid_hashtbl);
+err_sessionid:
+	kfree(nn->unconf_id_hashtbl);
+err_unconf_id:
+	kfree(nn->conf_id_hashtbl);
+err:
+	return -ENOMEM;
+}
+
+static void
+nfs4_state_destroy_net(struct net *net)
+{
+	int i;
+	struct nfs4_client *clp = NULL;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->conf_id_hashtbl[i])) {
+			clp = list_entry(nn->conf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
+			destroy_client(clp);
+		}
+	}
+
+	WARN_ON(!list_empty(&nn->blocked_locks_lru));
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->unconf_id_hashtbl[i])) {
+			clp = list_entry(nn->unconf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
+			destroy_client(clp);
+		}
+	}
+
+	kfree(nn->sessionid_hashtbl);
+	kfree(nn->unconf_id_hashtbl);
+	kfree(nn->conf_id_hashtbl);
+	put_net(net);
+}
+
+int
+nfs4_state_start_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int ret;
+
+	ret = nfs4_state_create_net(net);
+	if (ret)
+		return ret;
+	locks_start_grace(net, &nn->nfsd4_manager);
+	nfsd4_client_tracking_init(net);
+	/* safe for laundromat to run now */
+	enable_delayed_work(&nn->laundromat_work);
+	if (test_bit(NFSD_NET_TRACK_RECLAIM_COMPLETES, &nn->flags) &&
+	    nn->reclaim_str_hashtbl_size == 0)
+		goto skip_grace;
+	printk(KERN_INFO "NFSD: starting %lld-second grace period (net %x)\n",
+	       nn->nfsd4_grace, net->ns.inum);
+	trace_nfsd_grace_start(nn);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_grace * HZ);
+	return 0;
+
+skip_grace:
+	printk(KERN_INFO "NFSD: no clients to reclaim, skipping NFSv4 grace period (net %x)\n",
+			net->ns.inum);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_lease * HZ);
+	nfsd4_end_grace(nn);
+	return 0;
+}
+
+/* initialization to perform when the nfsd service is started: */
+int
+nfs4_state_start(void)
+{
+	int ret;
+
+	ret = rhltable_init(&nfs4_file_rhltable, &nfs4_file_rhash_params);
+	if (ret)
+		return ret;
+
+	nfsd_slot_shrinker = shrinker_alloc(0, "nfsd-DRC-slot");
+	if (!nfsd_slot_shrinker) {
+		rhltable_destroy(&nfs4_file_rhltable);
+		return -ENOMEM;
+	}
+	nfsd_slot_shrinker->count_objects = nfsd_slot_shrinker_count;
+	nfsd_slot_shrinker->scan_objects = nfsd_slot_shrinker_scan;
+	shrinker_register(nfsd_slot_shrinker);
+
+	set_max_delegations();
+	return 0;
+}
+
+void
+nfs4_state_shutdown_net(struct net *net)
+{
+	struct nfs4_delegation *dp = NULL;
+	struct list_head *pos, *next, reaplist;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	shrinker_free(nn->nfsd_client_shrinker);
+	cancel_work_sync(&nn->nfsd_shrinker_work);
+	disable_delayed_work_sync(&nn->laundromat_work);
+	locks_end_grace(&nn->nfsd4_manager);
+
+	INIT_LIST_HEAD(&reaplist);
+	spin_lock(&nn->deleg_lock);
+	list_for_each_safe(pos, next, &nn->del_recall_lru) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		unhash_delegation_locked(dp, SC_STATUS_CLOSED);
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&nn->deleg_lock);
+	list_for_each_safe(pos, next, &reaplist) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		destroy_unhashed_deleg(dp);
+	}
+
+	nfsd4_client_tracking_exit(net);
+	nfs4_state_destroy_net(net);
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+	nfsd4_ssc_shutdown_umount(nn);
+#endif
+}
+
+void
+nfs4_state_shutdown(void)
+{
+	rhltable_destroy(&nfs4_file_rhltable);
+	shrinker_free(nfsd_slot_shrinker);
+}
+
+static void
+get_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
+{
+	if (HAS_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG) &&
+	    CURRENT_STATEID(stateid))
+		memcpy(stateid, &cstate->current_stateid, sizeof(stateid_t));
+}
+
+static void
+put_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
+{
+	if (cstate->minorversion) {
+		memcpy(&cstate->current_stateid, stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+	}
+}
+
+void
+clear_current_stateid(struct nfsd4_compound_state *cstate)
+{
+	CLEAR_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+}
+
+/*
+ * functions to set current state id
+ */
+void
+nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->open_downgrade.od_stateid);
+}
+
+void
+nfsd4_set_openstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->open.op_stateid);
+}
+
+void
+nfsd4_set_closestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->close.cl_stateid);
+}
+
+void
+nfsd4_set_lockstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->lock.lk_resp_stateid);
+}
+
+/*
+ * functions to consume current state id
+ */
+
+void
+nfsd4_get_opendowngradestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->open_downgrade.od_stateid);
+}
+
+void
+nfsd4_get_delegreturnstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->delegreturn.dr_stateid);
+}
+
+void
+nfsd4_get_freestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->free_stateid.fr_stateid);
+}
+
+void
+nfsd4_get_setattrstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->setattr.sa_stateid);
+}
+
+void
+nfsd4_get_closestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->close.cl_stateid);
+}
+
+void
+nfsd4_get_lockustateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->locku.lu_stateid);
+}
+
+void
+nfsd4_get_readstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->read.rd_stateid);
+}
+
+void
+nfsd4_get_writestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->write.wr_stateid);
+}
+
+/**
+ * nfsd4_vet_deleg_time - vet and set the timespec for a delegated timestamp update
+ * @req: timestamp from the client
+ * @orig: original timestamp in the inode
+ * @now: current time
+ *
+ * Given a timestamp from the client response, check it against the
+ * current timestamp in the inode and the current time. Returns true
+ * if the inode's timestamp needs to be updated, and false otherwise.
+ * @req may also be changed if the timestamp needs to be clamped.
+ */
+bool nfsd4_vet_deleg_time(struct timespec64 *req, const struct timespec64 *orig,
+			  const struct timespec64 *now)
+{
+
+	/*
+	 * "When the time presented is before the original time, then the
+	 *  update is ignored." Also no need to update if there is no change.
+	 */
+	if (timespec64_compare(req, orig) <= 0)
+		return false;
+
+	/*
+	 * "When the time presented is in the future, the server can either
+	 *  clamp the new time to the current time, or it may
+	 *  return NFS4ERR_DELAY to the client, allowing it to retry."
+	 */
+	if (timespec64_compare(req, now) > 0)
+		*req = *now;
+
+	return true;
+}
+
+static int cb_getattr_update_times(struct dentry *dentry, struct nfs4_delegation *dp)
+{
+	struct inode *inode = d_inode(dentry);
+	struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
+	struct iattr attrs = { };
+	int ret;
+
+	if (deleg_attrs_deleg(dp->dl_type)) {
+		struct timespec64 now = current_time(inode);
+
+		attrs.ia_atime = ncf->ncf_cb_atime;
+		attrs.ia_mtime = ncf->ncf_cb_mtime;
+
+		if (nfsd4_vet_deleg_time(&attrs.ia_atime, &dp->dl_atime, &now))
+			attrs.ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+
+		if (nfsd4_vet_deleg_time(&attrs.ia_mtime, &dp->dl_mtime, &now)) {
+			attrs.ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+			attrs.ia_ctime = attrs.ia_mtime;
+			if (nfsd4_vet_deleg_time(&attrs.ia_ctime, &dp->dl_ctime, &now))
+				attrs.ia_valid |= ATTR_CTIME | ATTR_CTIME_SET;
+		}
+	} else {
+		attrs.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+	}
+
+	if (!attrs.ia_valid)
+		return 0;
+
+	attrs.ia_valid |= ATTR_DELEG;
+	inode_lock(inode);
+	ret = notify_change(&nop_mnt_idmap, dentry, &attrs, NULL);
+	inode_unlock(inode);
+	return ret;
+}
+
+/**
+ * nfsd4_deleg_getattr_conflict - Recall if GETATTR causes conflict
+ * @rqstp: RPC transaction context
+ * @dentry: dentry of inode to be checked for a conflict
+ * @pdp: returned WRITE delegation, if one was found
+ *
+ * This function is called when there is a conflict between a write
+ * delegation and a change/size GETATTR from another client. The server
+ * must either use the CB_GETATTR to get the current values of the
+ * attributes from the client that holds the delegation or recall the
+ * delegation before replying to the GETATTR. See RFC 8881 section
+ * 18.7.4.
+ *
+ * Returns 0 if there is no conflict; otherwise an nfs_stat
+ * code is returned. If @pdp is set to a non-NULL value, then the
+ * caller must put the reference.
+ */
+__be32
+nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry,
+			     struct nfs4_delegation **pdp)
+{
+	struct nfsd_thread_local_info *ntli = rqstp->rq_private;
+	struct file_lock_context *ctx;
+	struct nfs4_delegation *dp = NULL;
+	struct file_lease *fl;
+	struct nfs4_cb_fattr *ncf;
+	struct inode *inode = d_inode(dentry);
+	__be32 status;
+
+	ctx = locks_inode_context(inode);
+	if (!ctx)
+		return nfs_ok;
+
+#define NON_NFSD_LEASE ((void *)1)
+
+	spin_lock(&ctx->flc_lock);
+	for_each_file_lock(fl, &ctx->flc_lease) {
+		if (fl->c.flc_flags == FL_LAYOUT)
+			continue;
+		if (fl->c.flc_type == F_WRLCK) {
+			if (fl->fl_lmops == &nfsd_lease_mng_ops)
+				dp = fl->c.flc_owner;
+			else
+				dp = NON_NFSD_LEASE;
+		}
+		break;
+	}
+	if (dp == NULL || dp == NON_NFSD_LEASE ||
+	    dp->dl_recall.cb_clp == *(ntli->ntli_lease_breaker)) {
+		spin_unlock(&ctx->flc_lock);
+		if (dp == NON_NFSD_LEASE) {
+			status = nfserrno(nfsd_open_break_lease(inode,
+								NFSD_MAY_READ));
+			if (status != nfserr_jukebox ||
+			    !nfsd_wait_for_delegreturn(rqstp, inode))
+				return status;
+		}
+		return 0;
+	}
+
+	refcount_inc(&dp->dl_stid.sc_count);
+	ncf = &dp->dl_cb_fattr;
+	nfs4_cb_getattr(&dp->dl_cb_fattr);
+	spin_unlock(&ctx->flc_lock);
+
+	wait_on_bit_timeout(&ncf->ncf_getattr.cb_flags, NFSD4_CALLBACK_RUNNING,
+			    TASK_UNINTERRUPTIBLE, NFSD_CB_GETATTR_TIMEOUT);
+	if (ncf->ncf_cb_status) {
+		/* Recall delegation only if client didn't respond */
+		status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));
+		if (status != nfserr_jukebox ||
+		    !nfsd_wait_for_delegreturn(rqstp, inode))
+			goto out_status;
+		status = nfs_ok;
+		goto out_status;
+	}
+	if (!ncf->ncf_file_modified) {
+		if (ncf->ncf_initial_cinfo != ncf->ncf_cb_change)
+			ncf->ncf_file_modified = true;
+		else if (i_size_read(inode) != ncf->ncf_cb_fsize)
+			ncf->ncf_file_modified = true;
+	}
+	if (ncf->ncf_file_modified) {
+		int err;
+
+		/*
+		 * Per section 10.4.3 of RFC 8881, the server would
+		 * not update the file's metadata with the client's
+		 * modified size
+		 */
+		err = cb_getattr_update_times(dentry, dp);
+		if (err) {
+			status = nfserrno(err);
+			goto out_status;
+		}
+		ncf->ncf_cur_fsize = ncf->ncf_cb_fsize;
+		*pdp = dp;
+		return nfs_ok;
+	}
+	status = nfs_ok;
+out_status:
+	nfs4_put_stid(&dp->dl_stid);
+	return status;
+}
+
+#define GDD_WORD0_CHILD_ATTRS	(FATTR4_WORD0_TYPE |		\
+				 FATTR4_WORD0_CHANGE |		\
+				 FATTR4_WORD0_SIZE |		\
+				 FATTR4_WORD0_FILEID |		\
+				 FATTR4_WORD0_FILEHANDLE)
+
+#define GDD_WORD1_CHILD_ATTRS	(FATTR4_WORD1_MODE |		\
+				 FATTR4_WORD1_NUMLINKS |	\
+				 FATTR4_WORD1_RAWDEV |		\
+				 FATTR4_WORD1_SPACE_USED |	\
+				 FATTR4_WORD1_TIME_ACCESS |	\
+				 FATTR4_WORD1_TIME_METADATA |	\
+				 FATTR4_WORD1_TIME_MODIFY |	\
+				 FATTR4_WORD1_TIME_CREATE)
+
+#define GDD_WORD0_DIR_ATTRS	(FATTR4_WORD0_CHANGE |		\
+				 FATTR4_WORD0_SIZE)
+
+#define GDD_WORD1_DIR_ATTRS	(FATTR4_WORD1_NUMLINKS |	\
+				 FATTR4_WORD1_SPACE_USED |	\
+				 FATTR4_WORD1_TIME_ACCESS |	\
+				 FATTR4_WORD1_TIME_METADATA |	\
+				 FATTR4_WORD1_TIME_MODIFY)
+
+/**
+ * nfsd_get_dir_deleg - attempt to get a directory delegation
+ * @cstate: compound state
+ * @gdd: GET_DIR_DELEGATION arg/resp structure
+ * @nf: nfsd_file opened on the directory
+ *
+ * Given a GET_DIR_DELEGATION request @gdd, attempt to acquire a delegation
+ * on the directory to which @nf refers.
+ */
+struct nfs4_delegation *
+nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
+		   struct nfsd4_get_dir_delegation *gdd,
+		   struct nfsd_file *nf)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfs4_delegation *dp;
+	struct file_lease *fl;
+	struct nfs4_file *fp, *rfp;
+	int status = 0;
+
+	fp = nfsd4_alloc_file();
+	if (!fp)
+		return ERR_PTR(-ENOMEM);
+
+	nfsd4_file_init(&cstate->current_fh, fp);
+
+	rfp = nfsd4_file_hash_insert(fp, &cstate->current_fh);
+	if (unlikely(!rfp)) {
+		put_nfs4_file(fp);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	if (rfp != fp) {
+		put_nfs4_file(fp);
+		fp = rfp;
+	}
+
+	/* if this client already has one, return that it's unavailable */
+	spin_lock(&nn->deleg_lock);
+	spin_lock(&fp->fi_lock);
+	/* existing delegation? */
+	if (nfs4_delegation_exists(clp, fp)) {
+		status = -EAGAIN;
+	} else if (!rcu_dereference_protected(fp->fi_deleg_file,
+					      lockdep_is_held(&fp->fi_lock))) {
+		rcu_assign_pointer(fp->fi_deleg_file, nfsd_file_get(nf));
+		fp->fi_delegees = 1;
+	} else {
+		++fp->fi_delegees;
+	}
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&nn->deleg_lock);
+
+	if (status) {
+		put_nfs4_file(fp);
+		return ERR_PTR(status);
+	}
+
+	/* Try to set up the lease */
+	status = -ENOMEM;
+	dp = alloc_init_dir_deleg(clp, fp);
+	if (!dp)
+		goto out_delegees;
+	if (cstate->current_fh.fh_export)
+		dp->dl_stid.sc_export =
+			exp_get(cstate->current_fh.fh_export);
+
+	/*
+	 * NB: gddr_notification[0] represents the notifications that
+	 * will be granted to the client
+	 */
+	dp->dl_notify_mask = gdd->gddr_notification[0];
+	dp->dl_child_attrs[0] = gdd->gdda_child_attributes[0] & GDD_WORD0_CHILD_ATTRS;
+	dp->dl_child_attrs[1] = gdd->gdda_child_attributes[1] & GDD_WORD1_CHILD_ATTRS;
+	dp->dl_dir_attrs[0] = gdd->gdda_dir_attributes[0] & GDD_WORD0_DIR_ATTRS;
+	dp->dl_dir_attrs[1] = gdd->gdda_dir_attributes[1] & GDD_WORD1_DIR_ATTRS;
+
+	fl = nfs4_alloc_init_lease(dp, dp->dl_notify_mask);
+	if (!fl)
+		goto out_put_stid;
+
+	status = kernel_setlease(nf->nf_file,
+				 fl->c.flc_type, &fl, NULL);
+	if (fl)
+		locks_free_lease(fl);
+	if (status)
+		goto out_put_stid;
+
+	/*
+	 * Now, try to hash it. This can fail if we race another nfsd task
+	 * trying to set a delegation on the same file. If that happens,
+	 * then just say UNAVAIL.
+	 */
+	spin_lock(&nn->deleg_lock);
+	spin_lock(&clp->cl_lock);
+	spin_lock(&fp->fi_lock);
+	status = hash_delegation_locked(dp, fp);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&clp->cl_lock);
+	spin_unlock(&nn->deleg_lock);
+
+	if (!status) {
+		put_nfs4_file(fp);
+		nfsd_fsnotify_recalc_mask(nf);
+		return dp;
+	}
+
+	/*
+	 * Something failed after the lease was set. Drop the lease and clean
+	 * up the stid. The lease's flc_file is the fi_deleg_file (see
+	 * nfs4_alloc_init_lease()), which is not necessarily this client's
+	 * @nf when an earlier client already holds a delegation on @fp.
+	 * generic_delete_lease() matches on flc_file, so unlock against
+	 * fi_deleg_file or the lease will be leaked (and later freed with the
+	 * stid, leading to a use-after-free when it's eventually broken).
+	 */
+	kernel_setlease(rcu_dereference_protected(fp->fi_deleg_file, 1)->nf_file,
+			F_UNLCK, NULL, (void **)&dp);
+	nfsd_fsnotify_recalc_mask(nf);
+out_put_stid:
+	nfs4_put_stid(&dp->dl_stid);
+out_delegees:
+	put_deleg_file(fp);
+	put_nfs4_file(fp);
+	return ERR_PTR(status);
+}
+
+/**
+ * nfsd_update_cmtime_attr - update file's delegated ctime/mtime,
+ *                           and optionally other attributes (ie ATTR_ATIME).
+ * @f: pointer to an opened file
+ * @flags: any additional flags that should be updated
+ *
+ * Given upon opening a file delegated attributes were issues, update
+ * @f attributes to current times.
+ */
+void nfsd_update_cmtime_attr(struct file *f, unsigned int flags)
+{
+	int ret;
+	struct inode *inode = file_inode(f);
+	struct iattr attr = {
+		.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_DELEG | flags,
+	};
+
+	inode_lock(inode);
+	ret = notify_change(&nop_mnt_idmap, f->f_path.dentry, &attr, NULL);
+	inode_unlock(inode);
+	if (ret)
+		pr_notice_ratelimited("nfsd: Unable to update timestamps on "
+				      "inode %02x:%02x:%llu: %d\n",
+				      MAJOR(inode->i_sb->s_dev),
+				      MINOR(inode->i_sb->s_dev),
+				      inode->i_ino, ret);
+}
+
+static void
+nfsd4_run_cb_notify(struct nfsd4_cb_notify *ncn)
+{
+	struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
+
+	if (test_and_set_bit(NFSD4_CALLBACK_RUNNING, &ncn->ncn_cb.cb_flags))
+		return;
+
+	if (!refcount_inc_not_zero(&dp->dl_stid.sc_count))
+		clear_bit(NFSD4_CALLBACK_RUNNING, &ncn->ncn_cb.cb_flags);
+	else
+		nfsd4_run_cb(&ncn->ncn_cb);
+}
+
+static struct nfsd_notify_event *
+alloc_nfsd_notify_event(u32 mask, const struct qstr *q, struct dentry *dentry,
+			struct inode *target)
+{
+	struct nfsd_notify_event *ne;
+	struct name_snapshot newname;
+	u32 newnamelen = 0;
+
+	/*
+	 * For a rename, @q is the old name and the live dentry carries the new
+	 * name. Snapshot the new name now, while it is guaranteed to describe
+	 * this event: the dentry can be renamed again before the CB_NOTIFY work
+	 * runs, which would corrupt a late read in nfsd4_encode_notify_event().
+	 */
+	if (mask & FS_RENAME) {
+		take_dentry_name_snapshot(&newname, dentry);
+		newnamelen = newname.name.len;
+	}
+
+	ne = kmalloc_flex(*ne, ne_name,
+			  q->len + 1 + (newnamelen ? newnamelen + 1 : 0),
+			  GFP_NOFS);
+	if (!ne)
+		goto out;
+
+	memcpy(ne->ne_name, q->name, q->len);
+	ne->ne_name[q->len] = '\0';
+	ne->ne_namelen = q->len;
+
+	ne->ne_newnamelen = newnamelen;
+	if (newnamelen) {
+		char *p = nfsd_notify_event_newname(ne);
+
+		memcpy(p, newname.name.name, newnamelen);
+		p[newnamelen] = '\0';
+	}
+
+	refcount_set(&ne->ne_ref, 1);
+	ne->ne_mask = mask;
+	ne->ne_dentry = dget(dentry);
+	ne->ne_target = target;
+	if (ne->ne_target)
+		ihold(ne->ne_target);
+out:
+	if (mask & FS_RENAME)
+		release_dentry_name_snapshot(&newname);
+	return ne;
+}
+
+static bool
+should_notify_deleg(u32 mask, struct file_lease *fl)
+{
+	/* Don't notify the client generating the event */
+	if (nfsd_breaker_owns_lease(fl))
+		return false;
+
+	/* Skip if this event wasn't ignored by the lease */
+	if ((mask & FS_DELETE) && !(fl->c.flc_flags & FL_IGN_DIR_DELETE))
+		return false;
+	if ((mask & FS_CREATE) && !(fl->c.flc_flags & FL_IGN_DIR_CREATE))
+		return false;
+	if ((mask & FS_RENAME) && !(fl->c.flc_flags & FL_IGN_DIR_RENAME))
+		return false;
+
+	return true;
+}
+
+static void
+nfsd_recall_all_dir_delegs(const struct inode *dir)
+{
+	struct file_lock_context *ctx = locks_inode_context(dir);
+	struct file_lock_core *flc;
+
+	spin_lock(&ctx->flc_lock);
+	list_for_each_entry(flc, &ctx->flc_lease, flc_list) {
+		struct file_lease *fl = container_of(flc, struct file_lease, c);
+
+		if (fl->fl_lmops == &nfsd_lease_mng_ops)
+			nfsd_break_deleg_cb(fl);
+	}
+	spin_unlock(&ctx->flc_lock);
+}
+
+int
+nfsd_handle_dir_event(u32 mask, const struct inode *dir, const void *data,
+		      int data_type, const struct qstr *name)
+{
+	struct dentry *dentry = fsnotify_data_dentry(data, data_type);
+	struct inode *target = fsnotify_data_rename_target(data, data_type);
+	struct file_lock_context *ctx;
+	struct file_lock_core *flc;
+	struct nfsd_notify_event *evt;
+
+	trace_nfsd_handle_dir_event(mask, dir, name);
+
+	/* Normalize cross-dir rename events to create/delete */
+	if (mask & FS_MOVED_FROM) {
+		mask &= ~FS_MOVED_FROM;
+		mask |= FS_DELETE;
+	}
+	if (mask & FS_MOVED_TO) {
+		mask &= ~FS_MOVED_TO;
+		mask |= FS_CREATE;
+	}
+
+	/*
+	 * FS_RENAME fires on the source directory even for a cross-dir
+	 * rename, where the moved entry now lives under a different parent.
+	 * NOTIFY4_RENAME_ENTRY describes an in-place rename, so reporting it
+	 * here would advertise a name absent from this directory.
+	 */
+	if ((mask & FS_RENAME) && dentry && d_inode(dentry->d_parent) != dir)
+		mask &= ~FS_RENAME;
+
+	/* Don't do anything if this is not an expected event */
+	if (!(mask & (FS_CREATE|FS_DELETE|FS_RENAME)))
+		return 0;
+
+	ctx = locks_inode_context(dir);
+	if (!ctx || list_empty(&ctx->flc_lease))
+		return 0;
+
+	evt = alloc_nfsd_notify_event(mask, name, dentry, target);
+	if (!evt) {
+		nfsd_recall_all_dir_delegs(dir);
+		return 0;
+	}
+
+	spin_lock(&ctx->flc_lock);
+	list_for_each_entry(flc, &ctx->flc_lease, flc_list) {
+		struct file_lease *fl = container_of(flc, struct file_lease, c);
+		struct nfs4_delegation *dp = flc->flc_owner;
+		struct nfsd4_cb_notify *ncn = &dp->dl_cb_notify;
+
+		if (!should_notify_deleg(mask, fl))
+			continue;
+
+		spin_lock(&ncn->ncn_lock);
+		if (ncn->ncn_evt_cnt >= NOTIFY4_EVENT_QUEUE_SIZE) {
+			/* We're generating notifications too fast. Recall. */
+			spin_unlock(&ncn->ncn_lock);
+			nfsd_break_deleg_cb(fl);
+			continue;
+		}
+		ncn->ncn_evt[ncn->ncn_evt_cnt++] = nfsd_notify_event_get(evt);
+		spin_unlock(&ncn->ncn_lock);
+
+		nfsd4_run_cb_notify(ncn);
+	}
+	spin_unlock(&ctx->flc_lock);
+	nfsd_notify_event_put(evt);
+	return 0;
+}
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
new file mode 100644
index 000000000..606ddcb08
--- /dev/null
+++ b/fs/nfsd/nfs4xdr.c
@@ -0,0 +1,6810 @@
+/*
+ *  Server-side XDR for NFSv4
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/statfs.h>
+#include <linux/utsname.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/xattr.h>
+#include <linux/vmalloc.h>
+#include <linux/nfsacl.h>
+
+#include <uapi/linux/xattr.h>
+
+#include "attr4.h"
+#include "auth.h"
+#include "idmap.h"
+#include "acl.h"
+#include "xdr4.h"
+#include "vfs.h"
+#include "state.h"
+#include "cache.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "nfs4xdr_gen.h"
+
+#include "trace.h"
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+#endif
+
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+const u32 nfsd_suppattrs[3][3] = {
+	{NFSD4_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
+};
+
+/*
+ * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
+ * directory in order to indicate to the client that a filesystem boundary is present
+ * We use a fixed fsid for a referral
+ */
+#define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
+#define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
+
+static __be32
+check_filename(char *str, int len)
+{
+	int i;
+
+	if (len == 0)
+		return nfserr_inval;
+	if (len > NFS4_MAXNAMLEN)
+		return nfserr_nametoolong;
+	if (name_is_dot_dotdot(str, len))
+		return nfserr_badname;
+	for (i = 0; i < len; i++)
+		if (str[i] == '/')
+			return nfserr_badname;
+	return 0;
+}
+
+static int zero_clientid(clientid_t *clid)
+{
+	return (clid->cl_boot == 0) && (clid->cl_id == 0);
+}
+
+/**
+ * svcxdr_tmpalloc - allocate memory to be freed after compound processing
+ * @argp: NFSv4 compound argument structure
+ * @len: length of buffer to allocate
+ *
+ * Allocates a buffer of size @len to be freed when processing the compound
+ * operation described in @argp finishes.
+ */
+static void *
+svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, size_t len)
+{
+	struct svcxdr_tmpbuf *tb;
+
+	tb = kmalloc_flex(*tb, buf, len);
+	if (!tb)
+		return NULL;
+	tb->next = argp->to_free;
+	argp->to_free = tb;
+	return tb->buf;
+}
+
+/*
+ * For xdr strings that need to be passed to other kernel api's
+ * as null-terminated strings.
+ *
+ * Note null-terminating in place usually isn't safe since the
+ * buffer might end on a page boundary.
+ */
+static char *
+svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, size_t len)
+{
+	char *p = svcxdr_tmpalloc(argp, size_add(len, 1));
+
+	if (!p)
+		return NULL;
+	memcpy(p, buf, len);
+	p[len] = '\0';
+	return p;
+}
+
+static void *
+svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, size_t len)
+{
+	__be32 *tmp;
+
+	/*
+	 * The location of the decoded data item is stable,
+	 * so @p is OK to use. This is the common case.
+	 */
+	if (p != argp->xdr->scratch.iov_base)
+		return p;
+
+	tmp = svcxdr_tmpalloc(argp, len);
+	if (!tmp)
+		return NULL;
+	memcpy(tmp, p, len);
+	return tmp;
+}
+
+/*
+ * NFSv4 basic data type decoders
+ */
+
+/*
+ * This helper handles variable-length opaques which belong to protocol
+ * elements that this implementation does not support.
+ */
+static __be32
+nfsd4_decode_ignored_string(struct nfsd4_compoundargs *argp, u32 maxlen)
+{
+	u32 len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	if (maxlen && len > maxlen)
+		return nfserr_bad_xdr;
+	if (!xdr_inline_decode(argp->xdr, len))
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	if (len == 0 || len > NFS4_OPAQUE_LIMIT)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, len);
+	if (!p)
+		return nfserr_bad_xdr;
+	o->data = svcxdr_savemem(argp, p, len);
+	if (!o->data)
+		return nfserr_jukebox;
+	o->len = len;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
+{
+	__be32 *p, status;
+
+	if (xdr_stream_decode_u32(argp->xdr, lenp) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, *lenp);
+	if (!p)
+		return nfserr_bad_xdr;
+	status = check_filename((char *)p, *lenp);
+	if (status)
+		return status;
+	*namp = svcxdr_savemem(argp, p, *lenp);
+	if (!*namp)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
+	if (!p)
+		return nfserr_bad_xdr;
+	p = xdr_decode_hyper(p, &tv->tv_sec);
+	tv->tv_nsec = be32_to_cpup(p++);
+	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+		return nfserr_inval;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(verf->data, p, sizeof(verf->data));
+	return nfs_ok;
+}
+
+/**
+ * nfsd4_decode_bitmap4 - Decode an NFSv4 bitmap4
+ * @argp: NFSv4 compound argument structure
+ * @bmval: pointer to an array of u32's to decode into
+ * @bmlen: size of the @bmval array
+ *
+ * The server needs to return nfs_ok rather than nfserr_bad_xdr when
+ * encountering bitmaps containing bits it does not recognize. This
+ * includes bits in bitmap words past WORDn, where WORDn is the last
+ * bitmap WORD the implementation currently supports. Thus we are
+ * careful here to simply ignore bits in bitmap words that this
+ * implementation has yet to support explicitly.
+ *
+ * Return values:
+ *   %nfs_ok: @bmval populated successfully
+ *   %nfserr_bad_xdr: the encoded bitmap was invalid
+ */
+static __be32
+nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
+{
+	ssize_t status;
+
+	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
+	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
+{
+	__be32 *p, status;
+	u32 length;
+
+	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, length);
+	if (!p)
+		return nfserr_bad_xdr;
+	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
+	if (ace->whotype != NFS4_ACL_WHO_NAMED)
+		status = nfs_ok;
+	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+		status = nfsd_map_name_to_gid(argp->rqstp,
+				(char *)p, length, &ace->who_gid);
+	else
+		status = nfsd_map_name_to_uid(argp->rqstp,
+				(char *)p, length, &ace->who_uid);
+
+	return status;
+}
+
+/* A counted array of nfsace4's */
+static noinline __be32
+nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
+{
+	struct nfs4_ace *ace;
+	__be32 status;
+	u32 count;
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+
+	if (count > xdr_stream_remaining(argp->xdr) / 20)
+		/*
+		 * Even with 4-byte names there wouldn't be
+		 * space for that many aces; something fishy is
+		 * going on:
+		 */
+		return nfserr_fbig;
+
+	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
+	if (*acl == NULL)
+		return nfserr_jukebox;
+
+	(*acl)->naces = count;
+	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
+		status = nfsd4_decode_nfsace4(argp, ace);
+		if (status)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+static noinline __be32
+nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
+			    struct xdr_netobj *label)
+{
+	u32 lfs, pi, length;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+		return nfserr_bad_xdr;
+	if (length > NFS4_MAXLABELLEN)
+		return nfserr_badlabel;
+	p = xdr_inline_decode(argp->xdr, length);
+	if (!p)
+		return nfserr_bad_xdr;
+	label->len = length;
+	label->data = svcxdr_dupstr(argp, p, length);
+	if (!label->data)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+
+static short nfsd4_posixacetag4_to_tag(posixacetag4 tag)
+{
+	switch (tag) {
+	case POSIXACE4_TAG_USER_OBJ:	return ACL_USER_OBJ;
+	case POSIXACE4_TAG_GROUP_OBJ:	return ACL_GROUP_OBJ;
+	case POSIXACE4_TAG_USER:	return ACL_USER;
+	case POSIXACE4_TAG_GROUP:	return ACL_GROUP;
+	case POSIXACE4_TAG_MASK:	return ACL_MASK;
+	case POSIXACE4_TAG_OTHER:	return ACL_OTHER;
+	}
+	return ACL_OTHER;
+}
+
+static __be32
+nfsd4_decode_posixace4(struct nfsd4_compoundargs *argp,
+		       struct posix_acl_entry *ace)
+{
+	posixaceperm4 perm;
+	__be32 *p, status;
+	posixacetag4 tag;
+	u32 len;
+
+	if (!xdrgen_decode_posixacetag4(argp->xdr, &tag))
+		return nfserr_bad_xdr;
+	ace->e_tag = nfsd4_posixacetag4_to_tag(tag);
+
+	if (!xdrgen_decode_posixaceperm4(argp->xdr, &perm))
+		return nfserr_bad_xdr;
+	if (perm & ~S_IRWXO)
+		return nfserr_bad_xdr;
+	ace->e_perm = perm;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, len);
+	if (!p)
+		return nfserr_bad_xdr;
+	switch (tag) {
+	case POSIXACE4_TAG_USER:
+		if (len > 0)
+			status = nfsd_map_name_to_uid(argp->rqstp,
+					(char *)p, len, &ace->e_uid);
+		else
+			status = nfserr_bad_xdr;
+		break;
+	case POSIXACE4_TAG_GROUP:
+		if (len > 0)
+			status = nfsd_map_name_to_gid(argp->rqstp,
+					(char *)p, len, &ace->e_gid);
+		else
+			status = nfserr_bad_xdr;
+		break;
+	default:
+		status = nfs_ok;
+	}
+
+	return status;
+}
+
+static noinline __be32
+nfsd4_decode_posixacl(struct nfsd4_compoundargs *argp, struct posix_acl **acl)
+{
+	struct posix_acl_entry *ace;
+	__be32 status;
+	u32 count;
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+
+	/*
+	 * The NFSv4 POSIX ACL draft doesn't define a max number of ACE's, but
+	 * the NFSACL spec does. For NFSv4, cap the number of entries to the v3
+	 * limit, as we want to ensure that ACLs set via NFSv4 POSIX ACL
+	 * extensions are retrievable via NFSACL.
+	 */
+	if (count > NFS_ACL_MAX_ENTRIES)
+		return nfserr_inval;
+
+	*acl = posix_acl_alloc(count, GFP_KERNEL);
+	if (*acl == NULL)
+		return nfserr_jukebox;
+
+	(*acl)->a_count = count;
+	for (ace = (*acl)->a_entries; ace < (*acl)->a_entries + count; ace++) {
+		status = nfsd4_decode_posixace4(argp, ace);
+		if (status) {
+			posix_acl_release(*acl);
+			*acl = NULL;
+			return status;
+		}
+	}
+
+	/*
+	 * posix_acl_valid() requires the ACEs to be sorted.
+	 * If they are already sorted, sort_pacl_range() will return
+	 * after one pass through the ACEs, since it implements bubble sort.
+	 * Note that a count == 0 is used to delete a POSIX ACL and a count
+	 * of 1 or 2 will always be found invalid by posix_acl_valid().
+	 */
+	if (count >= 3)
+		sort_pacl_range(*acl, 0, count - 1);
+
+	return nfs_ok;
+}
+
+#endif /* CONFIG_NFSD_V4_POSIX_ACLS */
+
+static __be32
+nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
+		    struct iattr *iattr, struct nfs4_acl **acl,
+		    struct xdr_netobj *label, int *umask,
+		    struct posix_acl **dpaclp, struct posix_acl **paclp)
+{
+	unsigned int starting_pos;
+	u32 attrlist4_count;
+	__be32 *p, status;
+
+	iattr->ia_valid = 0;
+	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
+	if (status)
+		return nfserr_bad_xdr;
+
+	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
+	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
+	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
+		if (nfsd_attrs_supported(argp->minorversion, bmval))
+			return nfserr_inval;
+		return nfserr_attrnotsupp;
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
+		return nfserr_bad_xdr;
+	starting_pos = xdr_stream_pos(argp->xdr);
+
+	if (bmval[0] & FATTR4_WORD0_SIZE) {
+		u64 size;
+
+		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_size = size;
+		iattr->ia_valid |= ATTR_SIZE;
+	}
+	if (bmval[0] & FATTR4_WORD0_ACL) {
+		status = nfsd4_decode_acl(argp, acl);
+		if (status)
+			return status;
+	} else
+		*acl = NULL;
+	if (bmval[1] & FATTR4_WORD1_MODE) {
+		u32 mode;
+
+		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_mode = mode;
+		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
+		iattr->ia_valid |= ATTR_MODE;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER) {
+		u32 length;
+
+		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+			return nfserr_bad_xdr;
+		p = xdr_inline_decode(argp->xdr, length);
+		if (!p)
+			return nfserr_bad_xdr;
+		status = nfsd_map_name_to_uid(argp->rqstp, (char *)p, length,
+					      &iattr->ia_uid);
+		if (status)
+			return status;
+		iattr->ia_valid |= ATTR_UID;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
+		u32 length;
+
+		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+			return nfserr_bad_xdr;
+		p = xdr_inline_decode(argp->xdr, length);
+		if (!p)
+			return nfserr_bad_xdr;
+		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
+					      &iattr->ia_gid);
+		if (status)
+			return status;
+		iattr->ia_valid |= ATTR_GID;
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_ATIME;
+			break;
+		default:
+			return nfserr_bad_xdr;
+		}
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_CREATE) {
+		struct timespec64 ts;
+
+		/* No Linux filesystem supports setting this attribute. */
+		bmval[1] &= ~FATTR4_WORD1_TIME_CREATE;
+		status = nfsd4_decode_nfstime4(argp, &ts);
+		if (status)
+			return status;
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_MTIME;
+			break;
+		default:
+			return nfserr_bad_xdr;
+		}
+	}
+	label->len = 0;
+	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
+	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
+		status = nfsd4_decode_security_label(argp, label);
+		if (status)
+			return status;
+	}
+	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
+		u32 mode, mask;
+
+		if (!umask)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
+		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
+			return nfserr_bad_xdr;
+		*umask = mask & S_IRWXUGO;
+		iattr->ia_valid |= ATTR_MODE;
+	}
+	if (bmval[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
+		fattr4_time_deleg_access access;
+
+		if (!xdrgen_decode_fattr4_time_deleg_access(argp->xdr, &access))
+			return nfserr_bad_xdr;
+		if (access.nseconds >= NSEC_PER_SEC)
+			return nfserr_inval;
+		iattr->ia_atime.tv_sec = access.seconds;
+		iattr->ia_atime.tv_nsec = access.nseconds;
+		iattr->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET | ATTR_DELEG;
+	}
+	if (bmval[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
+		fattr4_time_deleg_modify modify;
+
+		if (!xdrgen_decode_fattr4_time_deleg_modify(argp->xdr, &modify))
+			return nfserr_bad_xdr;
+		if (modify.nseconds >= NSEC_PER_SEC)
+			return nfserr_inval;
+		iattr->ia_mtime.tv_sec = modify.seconds;
+		iattr->ia_mtime.tv_nsec = modify.nseconds;
+		iattr->ia_ctime.tv_sec = modify.seconds;
+		iattr->ia_ctime.tv_nsec = modify.nseconds;
+		iattr->ia_valid |= ATTR_CTIME | ATTR_CTIME_SET |
+				   ATTR_MTIME | ATTR_MTIME_SET | ATTR_DELEG;
+	}
+
+	*dpaclp = NULL;
+	*paclp = NULL;
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	if (bmval[2] & FATTR4_WORD2_POSIX_DEFAULT_ACL) {
+		struct posix_acl *dpacl;
+
+		status = nfsd4_decode_posixacl(argp, &dpacl);
+		if (status)
+			return status;
+		*dpaclp = dpacl;
+	}
+	if (bmval[2] & FATTR4_WORD2_POSIX_ACCESS_ACL) {
+		struct posix_acl *pacl;
+
+		status = nfsd4_decode_posixacl(argp, &pacl);
+		if (status) {
+			posix_acl_release(*dpaclp);
+			*dpaclp = NULL;
+			return status;
+		}
+		*paclp = pacl;
+	}
+#endif /* CONFIG_NFSD_V4_POSIX_ACLS */
+
+	/* request sanity: did attrlist4 contain the expected number of words? */
+	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos) {
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+		posix_acl_release(*dpaclp);
+		posix_acl_release(*paclp);
+		*dpaclp = NULL;
+		*paclp = NULL;
+#endif
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
+	if (!p)
+		return nfserr_bad_xdr;
+	sid->si_generation = be32_to_cpup(p++);
+	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(clientid, p, sizeof(*clientid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
+			  clientid_t *clientid, struct xdr_netobj *owner)
+{
+	__be32 status;
+
+	status = nfsd4_decode_clientid4(argp, clientid);
+	if (status)
+		return status;
+	return nfsd4_decode_opaque(argp, owner);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+
+static __be32
+nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_layoutcommit *lcp)
+{
+	u32 len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
+		return nfserr_bad_xdr;
+	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	if (!xdr_stream_subsegment(argp->xdr, &lcp->lc_up_layout, len))
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_layoutreturn *lrp)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
+		return nfserr_bad_xdr;
+	switch (lrp->lr_return_type) {
+	case RETURN_FILE:
+		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
+		if (status)
+			return status;
+		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
+			return nfserr_bad_xdr;
+		if (lrp->lrf_body_len > 0) {
+			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
+			if (!lrp->lrf_body)
+				return nfserr_bad_xdr;
+		}
+		break;
+	case RETURN_FSID:
+	case RETURN_ALL:
+		lrp->lr_seg.offset = 0;
+		lrp->lr_seg.length = NFS4_MAX_UINT64;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
+			struct nfs4_sessionid *sessionid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(sessionid->data, p, sizeof(sessionid->data));
+	return nfs_ok;
+}
+
+/* Defined in Appendix A of RFC 5531 */
+static __be32
+nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_cb_sec *cbs)
+{
+	u32 stamp, gidcount, uid, gid;
+	__be32 *p, status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
+		return nfserr_bad_xdr;
+	/* machine name */
+	status = nfsd4_decode_ignored_string(argp, 255);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
+		return nfserr_bad_xdr;
+	if (gidcount > 16)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, gidcount << 2);
+	if (!p)
+		return nfserr_bad_xdr;
+	if (cbs->flavor == (u32)(-1)) {
+		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
+
+		kuid_t kuid = make_kuid(userns, uid);
+		kgid_t kgid = make_kgid(userns, gid);
+		if (uid_valid(kuid) && gid_valid(kgid)) {
+			cbs->uid = kuid;
+			cbs->gid = kgid;
+			cbs->flavor = RPC_AUTH_UNIX;
+		} else {
+			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
+		}
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
+			     struct nfsd4_cb_sec *cbs)
+{
+	__be32 status;
+	u32 service;
+
+	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
+
+	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
+		return nfserr_bad_xdr;
+	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
+		return nfserr_bad_xdr;
+	/* gcbp_handle_from_server */
+	status = nfsd4_decode_ignored_string(argp, 0);
+	if (status)
+		return status;
+	/* gcbp_handle_from_client */
+	status = nfsd4_decode_ignored_string(argp, 0);
+	if (status)
+		return status;
+
+	return nfs_ok;
+}
+
+/* a counted array of callback_sec_parms4 items */
+static __be32
+nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
+{
+	u32 i, secflavor, nr_secflavs;
+	__be32 status;
+
+	/* callback_sec_params4 */
+	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
+		return nfserr_bad_xdr;
+	if (nr_secflavs)
+		cbs->flavor = (u32)(-1);
+	else
+		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
+		cbs->flavor = 0;
+
+	for (i = 0; i < nr_secflavs; ++i) {
+		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
+			return nfserr_bad_xdr;
+		switch (secflavor) {
+		case RPC_AUTH_NULL:
+			/* void */
+			if (cbs->flavor == (u32)(-1))
+				cbs->flavor = RPC_AUTH_NULL;
+			break;
+		case RPC_AUTH_UNIX:
+			status = nfsd4_decode_authsys_parms(argp, cbs);
+			if (status)
+				return status;
+			break;
+		case RPC_AUTH_GSS:
+			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
+			if (status)
+				return status;
+			break;
+		default:
+			return nfserr_inval;
+		}
+	}
+
+	return nfs_ok;
+}
+
+
+/*
+ * NFSv4 operation argument decoders
+ */
+
+static __be32
+nfsd4_decode_access(struct nfsd4_compoundargs *argp,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
+		return nfserr_bad_xdr;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_close(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
+}
+
+
+static __be32
+nfsd4_decode_commit(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
+		return nfserr_bad_xdr;
+	memset(&commit->co_verf, 0, sizeof(commit->co_verf));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_create(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	__be32 *p, status;
+
+	memset(create, 0, sizeof(*create));
+	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
+		return nfserr_bad_xdr;
+	switch (create->cr_type) {
+	case NF4LNK:
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
+			return nfserr_bad_xdr;
+		if (create->cr_datalen == 0)
+			return nfserr_inval;
+		if (create->cr_datalen > NFS4_MAXPATHLEN)
+			return nfserr_nametoolong;
+		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
+		if (!p)
+			return nfserr_bad_xdr;
+		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
+		if (!create->cr_data)
+			return nfserr_jukebox;
+		break;
+	case NF4BLK:
+	case NF4CHR:
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
+			return nfserr_bad_xdr;
+		break;
+	case NF4SOCK:
+	case NF4FIFO:
+	case NF4DIR:
+	default:
+		break;
+	}
+	status = nfsd4_decode_component4(argp, &create->cr_name,
+					 &create->cr_namelen);
+	if (status)
+		return status;
+	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
+				    ARRAY_SIZE(create->cr_bmval),
+				    &create->cr_iattr, &create->cr_acl,
+				    &create->cr_label, &create->cr_umask,
+				    &create->cr_dpacl, &create->cr_pacl);
+	if (status)
+		return status;
+
+	return nfs_ok;
+}
+
+static inline __be32
+nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_delegreturn *dr = &u->delegreturn;
+	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
+}
+
+static inline __be32
+nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	memset(getattr, 0, sizeof(*getattr));
+	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
+				    ARRAY_SIZE(getattr->ga_bmval));
+}
+
+static __be32
+nfsd4_decode_link(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	memset(link, 0, sizeof(*link));
+	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
+}
+
+static __be32
+nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
+				 struct nfsd4_lock *lock)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
+					 &lock->lk_new_owner);
+}
+
+static __be32
+nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
+			       struct nfsd4_lock *lock)
+{
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
+{
+	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
+		return nfserr_bad_xdr;
+	if (lock->lk_is_new)
+		return nfsd4_decode_open_to_lock_owner4(argp, lock);
+	return nfsd4_decode_exist_lock_owner4(argp, lock);
+}
+
+static __be32
+nfsd4_decode_lock(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	memset(lock, 0, sizeof(*lock));
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
+		return nfserr_bad_xdr;
+	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_locker4(argp, lock);
+}
+
+static __be32
+nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	memset(lockt, 0, sizeof(*lockt));
+	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
+		return nfserr_bad_xdr;
+	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
+					 &lockt->lt_owner);
+}
+
+static __be32
+nfsd4_decode_locku(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
+		return nfserr_bad_xdr;
+	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lookup *lookup = &u->lookup;
+	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
+}
+
+static __be32
+nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_createmode) {
+	case NFS4_CREATE_UNCHECKED:
+	case NFS4_CREATE_GUARDED:
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask,
+					     &open->op_dpacl, &open->op_pacl);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE:
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE4_1:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask,
+					     &open->op_dpacl, &open->op_pacl);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_create) {
+	case NFS4_OPEN_NOCREATE:
+		break;
+	case NFS4_OPEN_CREATE:
+		status = nfsd4_decode_createhow4(argp, open);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
+{
+	u32 w;
+
+	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
+		return nfserr_bad_xdr;
+	*share_access = w & NFS4_SHARE_ACCESS_MASK;
+	*deleg_want = w & NFS4_SHARE_WANT_MASK;
+	if (deleg_when)
+		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
+
+	switch (w & NFS4_SHARE_ACCESS_MASK) {
+	case NFS4_SHARE_ACCESS_READ:
+	case NFS4_SHARE_ACCESS_WRITE:
+	case NFS4_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_ACCESS_MASK;
+	if (!w)
+		return nfs_ok;
+	if (!argp->minorversion)
+		return nfserr_bad_xdr;
+	switch (w & NFS4_SHARE_WANT_TYPE_MASK) {
+	case OPEN4_SHARE_ACCESS_WANT_NO_PREFERENCE:
+	case OPEN4_SHARE_ACCESS_WANT_READ_DELEG:
+	case OPEN4_SHARE_ACCESS_WANT_WRITE_DELEG:
+	case OPEN4_SHARE_ACCESS_WANT_ANY_DELEG:
+	case OPEN4_SHARE_ACCESS_WANT_NO_DELEG:
+	case OPEN4_SHARE_ACCESS_WANT_CANCEL:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_WANT_MASK;
+	if (!w)
+		return nfs_ok;
+
+	if (!deleg_when)	/* open_downgrade */
+		return nfserr_inval;
+	switch (w) {
+	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
+	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
+	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
+	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
+		return nfs_ok;
+	}
+	return nfserr_bad_xdr;
+}
+
+static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
+{
+	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
+		return nfserr_bad_xdr;
+	/* Note: unlike access bits, deny bits may be zero. */
+	if (*x & ~NFS4_SHARE_DENY_BOTH)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_claim_type) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		status = nfsd4_decode_component4(argp, &open->op_fname,
+						 &open->op_fnamelen);
+		if (status)
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
+			return nfserr_bad_xdr;
+		break;
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		status = nfsd4_decode_component4(argp, &open->op_fname,
+						 &open->op_fnamelen);
+		if (status)
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_FH:
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		/* void */
+		break;
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	__be32 status;
+	u32 dummy;
+
+	memset(open, 0, sizeof(*open));
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
+		return nfserr_bad_xdr;
+	/* deleg_want is ignored */
+	status = nfsd4_decode_share_access(argp, &open->op_share_access,
+					   &open->op_deleg_want, &dummy);
+	if (status)
+		return status;
+	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
+	if (status)
+		return status;
+	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
+					   &open->op_owner);
+	if (status)
+		return status;
+	status = nfsd4_decode_openflag4(argp, open);
+	if (status)
+		return status;
+	return nfsd4_decode_open_claim4(argp, open);
+}
+
+static __be32
+nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *open_conf = &u->open_confirm;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
+		return nfserr_bad_xdr;
+
+	memset(&open_conf->oc_resp_stateid, 0,
+	       sizeof(open_conf->oc_resp_stateid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *open_down = &u->open_downgrade;
+	__be32 status;
+
+	memset(open_down, 0, sizeof(*open_down));
+	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
+		return nfserr_bad_xdr;
+	/* deleg_want is ignored */
+	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
+					   &open_down->od_deleg_want, NULL);
+	if (status)
+		return status;
+	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
+}
+
+static __be32
+nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_putfh *putfh = &u->putfh;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
+		return nfserr_bad_xdr;
+	if (putfh->pf_fhlen > NFS4_FHSIZE)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
+	if (!p)
+		return nfserr_bad_xdr;
+	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
+	if (!putfh->pf_fhval)
+		return nfserr_jukebox;
+
+	putfh->no_verify = false;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_read(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	__be32 status;
+
+	memset(read, 0, sizeof(*read));
+	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	__be32 status;
+
+	memset(readdir, 0, sizeof(*readdir));
+	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
+					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_remove(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	memset(&remove->rm_cinfo, 0, sizeof(remove->rm_cinfo));
+	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
+}
+
+static __be32
+nfsd4_decode_rename(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	__be32 status;
+
+	memset(rename, 0, sizeof(*rename));
+	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
+	if (status)
+		return status;
+	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
+}
+
+static __be32
+nfsd4_decode_renew(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	clientid_t *clientid = &u->renew;
+	return nfsd4_decode_clientid4(argp, clientid);
+}
+
+static __be32
+nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	secinfo->si_exp = NULL;
+	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
+}
+
+static __be32
+nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	__be32 status;
+
+	memset(setattr, 0, sizeof(*setattr));
+	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
+				   ARRAY_SIZE(setattr->sa_bmval),
+				   &setattr->sa_iattr, &setattr->sa_acl,
+				   &setattr->sa_label, NULL, &setattr->sa_dpacl,
+				   &setattr->sa_pacl);
+}
+
+static __be32
+nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *setclientid = &u->setclientid;
+	__be32 *p, status;
+
+	memset(setclientid, 0, sizeof(*setclientid));
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
+	if (status)
+		return status;
+	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
+	if (!p)
+		return nfserr_bad_xdr;
+	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
+						setclientid->se_callback_netid_len);
+	if (!setclientid->se_callback_netid_val)
+		return nfserr_jukebox;
+
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
+	if (!p)
+		return nfserr_bad_xdr;
+	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
+						setclientid->se_callback_addr_len);
+	if (!setclientid->se_callback_addr_val)
+		return nfserr_jukebox;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp,
+				 union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid_confirm *scd_c = &u->setclientid_confirm;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
+	if (status)
+		return status;
+	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
+}
+
+/* Also used for NVERIFY */
+static __be32
+nfsd4_decode_verify(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_verify *verify = &u->verify;
+	__be32 *p, status;
+
+	memset(verify, 0, sizeof(*verify));
+
+	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
+				      ARRAY_SIZE(verify->ve_bmval));
+	if (status)
+		return status;
+
+	/* For convenience's sake, we compare raw xdr'd attributes in
+	 * nfsd4_proc_verify */
+
+	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
+	if (!p)
+		return nfserr_bad_xdr;
+	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
+	if (!verify->ve_attrval)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_write(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
+		return nfserr_bad_xdr;
+	if (write->wr_stable_how > NFS_FILE_SYNC)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
+		return nfserr_bad_xdr;
+	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
+		return nfserr_bad_xdr;
+
+	write->wr_bytes_written = 0;
+	write->wr_how_written = 0;
+	memset(&write->wr_verifier, 0, sizeof(write->wr_verifier));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp,
+			       union nfsd4_op_u *u)
+{
+	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
+					   &rlockowner->rl_owner);
+	if (status)
+		return status;
+
+	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
+		return nfserr_inval;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp,
+					   union nfsd4_op_u *u)
+{
+	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
+	memset(bc, 0, sizeof(*bc));
+	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
+}
+
+static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp,
+						union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	u32 use_conn_in_rdma_mode;
+	__be32 status;
+
+	memset(bcts, 0, sizeof(*bcts));
+	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
+			       struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
+				      ARRAY_SIZE(exid->spo_must_enforce));
+	if (status)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
+				      ARRAY_SIZE(exid->spo_must_allow));
+	if (status)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+/*
+ * This implementation currently does not support SP4_SSV.
+ * This decoder simply skips over these arguments.
+ */
+static noinline __be32
+nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
+			  struct nfsd4_exchange_id *exid)
+{
+	u32 count, window, num_gss_handles;
+	__be32 status;
+
+	/* ssp_ops */
+	status = nfsd4_decode_state_protect_ops(argp, exid);
+	if (status)
+		return status;
+
+	/* ssp_hash_algs<> */
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	while (count--) {
+		status = nfsd4_decode_ignored_string(argp, 0);
+		if (status)
+			return status;
+	}
+
+	/* ssp_encr_algs<> */
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	while (count--) {
+		status = nfsd4_decode_ignored_string(argp, 0);
+		if (status)
+			return status;
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
+			      struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
+		return nfserr_bad_xdr;
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		status = nfsd4_decode_state_protect_ops(argp, exid);
+		if (status)
+			return status;
+		break;
+	case SP4_SSV:
+		status = nfsd4_decode_ssv_sp_parms(argp, exid);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
+			  struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+	u32 count;
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	switch (count) {
+	case 0:
+		break;
+	case 1:
+		/* Note that RFC 8881 places no length limit on
+		 * nii_domain, but this implementation permits no
+		 * more than NFS4_OPAQUE_LIMIT bytes */
+		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
+		if (status)
+			return status;
+		/* Note that RFC 8881 places no length limit on
+		 * nii_name, but this implementation permits no
+		 * more than NFS4_OPAQUE_LIMIT bytes */
+		status = nfsd4_decode_opaque(argp, &exid->nii_name);
+		if (status)
+			return status;
+		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	__be32 status;
+
+	memset(exid, 0, sizeof(*exid));
+	status = nfsd4_decode_verifier4(argp, &exid->verifier);
+	if (status)
+		return status;
+	status = nfsd4_decode_opaque(argp, &exid->clname);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_state_protect4_a(argp, exid);
+	if (status)
+		return status;
+	return nfsd4_decode_nfs_impl_id4(argp, exid);
+}
+
+static __be32
+nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
+			    struct nfsd4_channel_attrs *ca)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
+	if (!p)
+		return nfserr_bad_xdr;
+
+	/* headerpadsz is ignored */
+	p++;
+	ca->maxreq_sz = be32_to_cpup(p++);
+	ca->maxresp_sz = be32_to_cpup(p++);
+	ca->maxresp_cached = be32_to_cpup(p++);
+	ca->maxops = be32_to_cpup(p++);
+	ca->maxreqs = be32_to_cpup(p++);
+	ca->nr_rdma_attrs = be32_to_cpup(p);
+	switch (ca->nr_rdma_attrs) {
+	case 0:
+		break;
+	case 1:
+		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
+			return nfserr_bad_xdr;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *sess = &u->create_session;
+	__be32 status;
+
+	memset(sess, 0, sizeof(*sess));
+	status = nfsd4_decode_clientid4(argp, &sess->clientid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
+	if (status)
+		return status;
+	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_cb_sec(argp, &sess->cb_sec);
+}
+
+static __be32
+nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
+			     union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_session *destroy_session = &u->destroy_session;
+	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
+}
+
+static __be32
+nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
+	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
+}
+
+static __be32
+nfsd4_decode_get_dir_delegation(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	__be32 status;
+
+	memset(gdd, 0, sizeof(*gdd));
+
+	if (xdr_stream_decode_bool(argp->xdr, &gdd->gdda_signal_deleg_avail) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_bitmap4(argp, gdd->gdda_notification_types,
+				      ARRAY_SIZE(gdd->gdda_notification_types));
+	if (status)
+		return status;
+	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_child_attr_delay);
+	if (status)
+		return status;
+	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_dir_attr_delay);
+	if (status)
+		return status;
+	status = nfsd4_decode_bitmap4(argp, gdd->gdda_child_attributes,
+					ARRAY_SIZE(gdd->gdda_child_attributes));
+	if (status)
+		return status;
+	return nfsd4_decode_bitmap4(argp, gdd->gdda_dir_attributes,
+					ARRAY_SIZE(gdd->gdda_dir_attributes));
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
+	__be32 status;
+
+	memset(gdev, 0, sizeof(*gdev));
+	status = nfsd4_decode_deviceid4(argp->xdr, &gdev->gd_devid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_uint32_array(argp->xdr,
+					   &gdev->gd_notify_types, 1) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	__be32 *p, status;
+
+	memset(lcp, 0, sizeof(*lcp));
+	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_newoffset) < 0)
+		return nfserr_bad_xdr;
+	if (lcp->lc_newoffset) {
+		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
+			return nfserr_bad_xdr;
+	} else
+		lcp->lc_last_wr = 0;
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
+	if (!p)
+		return nfserr_bad_xdr;
+	if (xdr_item_is_present(p)) {
+		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
+		if (status)
+			return status;
+	} else {
+		lcp->lc_mtime.tv_nsec = UTIME_NOW;
+	}
+	return nfsd4_decode_layoutupdate4(argp, lcp);
+}
+
+static __be32
+nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	__be32 status;
+
+	memset(lgp, 0, sizeof(*lgp));
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	memset(lrp, 0, sizeof(*lrp));
+	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_layoutreturn4(argp, lrp);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
+					   union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name;
+
+	sin->sin_exp = NULL;
+	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	__be32 *p, status;
+
+	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
+	if (status)
+		return status;
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
+	if (!p)
+		return nfserr_bad_xdr;
+	seq->seqid = be32_to_cpup(p++);
+	seq->slotid = be32_to_cpup(p++);
+	/* sa_highest_slotid counts from 0 but maxslots  counts from 1 ... */
+	seq->maxslots = be32_to_cpup(p++) + 1;
+	seq->cachethis = be32_to_cpup(p);
+
+	seq->status_flags = 0;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct nfsd4_test_stateid_id *stateid;
+	__be32 status;
+	u32 i;
+
+	memset(test_stateid, 0, sizeof(*test_stateid));
+	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
+		return nfserr_bad_xdr;
+
+	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
+	for (i = 0; i < test_stateid->ts_num_ids; i++) {
+		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
+		if (!stateid)
+			return nfserr_jukebox;
+		INIT_LIST_HEAD(&stateid->ts_id_list);
+		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
+		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
+		if (status)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
+					    union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
+	return nfsd4_decode_clientid4(argp, &dc->clientid);
+}
+
+static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
+					    union nfsd4_op_u *u)
+{
+	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
+	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
+		return nfserr_bad_xdr;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
+		       union nfsd4_op_u *u)
+{
+	struct nfsd4_fallocate *fallocate = &u->allocate;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
+				      struct nl4_server *ns)
+{
+	struct nfs42_netaddr *naddr;
+	__be32 *p;
+	u32 str_len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
+		return nfserr_bad_xdr;
+
+	/* currently support for 1 inter-server source server */
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		naddr = &ns->u.nl4_addr;
+
+		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
+			return nfserr_bad_xdr;
+		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
+			return nfserr_bad_xdr;
+
+		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
+		if (!p)
+			return nfserr_bad_xdr;
+		memcpy(naddr->netid, p, naddr->netid_len);
+
+		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
+			return nfserr_bad_xdr;
+		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
+			return nfserr_bad_xdr;
+
+		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
+		if (!p)
+			return nfserr_bad_xdr;
+		memcpy(naddr->addr, p, naddr->addr_len);
+		break;
+	case NL4_NAME:
+	case NL4_URL:
+		/*
+		 * Well-formed XDR, but only NL4_NETADDR is supported. Consume
+		 * the utf8str_cis to keep the stream aligned, then return
+		 * NFS4ERR_NOTSUPP rather than the misleading NFS4ERR_BADXDR.
+		 */
+		if (xdr_stream_decode_u32(argp->xdr, &str_len) < 0)
+			return nfserr_bad_xdr;
+		if (!xdr_inline_decode(argp->xdr, str_len))
+			return nfserr_bad_xdr;
+		return nfserr_notsupp;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_copy(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_copy *copy = &u->copy;
+	u32 consecutive, i, count, sync;
+	struct nl4_server *ns_dummy;
+	__be32 status;
+
+	memset(copy, 0, sizeof(*copy));
+	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
+		return nfserr_bad_xdr;
+	/* ca_consecutive: we always do consecutive copies */
+	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
+		return nfserr_bad_xdr;
+	nfsd4_copy_set_sync(copy, sync);
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
+	if (copy->cp_src == NULL)
+		return nfserr_jukebox;
+	if (count == 0) { /* intra-server copy */
+		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+		return nfs_ok;
+	}
+
+	/* decode all the supplied server addresses but use only the first */
+	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
+	if (status)
+		return status;
+
+	ns_dummy = kmalloc_obj(struct nl4_server);
+	if (ns_dummy == NULL)
+		return nfserr_jukebox;
+	for (i = 0; i < count - 1; i++) {
+		status = nfsd4_decode_nl4_server(argp, ns_dummy);
+		if (status) {
+			kfree(ns_dummy);
+			return status;
+		}
+	}
+	kfree(ns_dummy);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	__be32 status;
+
+	memset(cn, 0, sizeof(*cn));
+	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
+	if (cn->cpn_src == NULL)
+		return nfserr_jukebox;
+	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
+	if (cn->cpn_dst == NULL)
+		return nfserr_jukebox;
+
+	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
+}
+
+static __be32
+nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	os->count = 0;
+	os->status = 0;
+	return nfsd4_decode_stateid4(argp, &os->stateid);
+}
+
+static __be32
+nfsd4_decode_seek(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
+		return nfserr_bad_xdr;
+
+	seek->seek_eof = 0;
+	seek->seek_pos = 0;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_clone(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_clone *clone = &u->clone;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+/*
+ * XDR data that is more than PAGE_SIZE in size is normally part of a
+ * read or write. However, the size of extended attributes is limited
+ * by the maximum request size, and then further limited by the underlying
+ * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
+ * is 64k). Since there is no kvec- or page-based interface to xattrs,
+ * and we're not dealing with contiguous pages, we need to do some copying.
+ */
+
+/*
+ * Decode data into buffer.
+ */
+static __be32
+nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
+		       char **bufp, size_t buflen)
+{
+	struct page **pages = xdr->pages;
+	struct kvec *head = xdr->head;
+	char *tmp, *dp;
+	u32 len;
+
+	if (buflen <= head->iov_len) {
+		/*
+		 * We're in luck, the head has enough space. Just return
+		 * the head, no need for copying.
+		 */
+		*bufp = head->iov_base;
+		return 0;
+	}
+
+	tmp = svcxdr_tmpalloc(argp, buflen);
+	if (tmp == NULL)
+		return nfserr_jukebox;
+
+	dp = tmp;
+	memcpy(dp, head->iov_base, head->iov_len);
+	buflen -= head->iov_len;
+	dp += head->iov_len;
+
+	while (buflen > 0) {
+		len = min_t(u32, buflen, PAGE_SIZE);
+		memcpy(dp, page_address(*pages), len);
+
+		buflen -= len;
+		dp += len;
+		pages++;
+	}
+
+	*bufp = tmp;
+	return 0;
+}
+
+/*
+ * Get a user extended attribute name from the XDR buffer.
+ * It will not have the "user." prefix, so prepend it.
+ * Lastly, check for nul characters in the name.
+ */
+static __be32
+nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
+{
+	char *name, *sp, *dp;
+	u32 namelen, cnt;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
+		return nfserr_bad_xdr;
+	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
+		return nfserr_nametoolong;
+	if (namelen == 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, namelen);
+	if (!p)
+		return nfserr_bad_xdr;
+	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
+	if (!name)
+		return nfserr_jukebox;
+	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+
+	/*
+	 * Copy the extended attribute name over while checking for 0
+	 * characters.
+	 */
+	sp = (char *)p;
+	dp = name + XATTR_USER_PREFIX_LEN;
+	cnt = namelen;
+
+	while (cnt-- > 0) {
+		if (*sp == '\0')
+			return nfserr_bad_xdr;
+		*dp++ = *sp++;
+	}
+	*dp = '\0';
+
+	*namep = name;
+
+	return nfs_ok;
+}
+
+/*
+ * A GETXATTR op request comes without a length specifier. We just set the
+ * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
+ * channel reply size. nfsd_getxattr will probe the length of the xattr,
+ * check it against getxa_len, and allocate + return the value.
+ */
+static __be32
+nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+	__be32 status;
+	u32 maxcount;
+
+	memset(getxattr, 0, sizeof(*getxattr));
+	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	getxattr->getxa_len = maxcount;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	u32 flags, maxcount, size;
+	__be32 status;
+
+	memset(setxattr, 0, sizeof(*setxattr));
+
+	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
+		return nfserr_bad_xdr;
+
+	if (flags > SETXATTR4_REPLACE)
+		return nfserr_inval;
+	setxattr->setxa_flags = flags;
+
+	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
+		return nfserr_bad_xdr;
+	if (size > maxcount)
+		return nfserr_xattr2big;
+
+	setxattr->setxa_len = size;
+	if (size > 0) {
+		struct xdr_buf payload;
+
+		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
+			return nfserr_bad_xdr;
+		status = nfsd4_vbuf_from_vector(argp, &payload,
+						&setxattr->setxa_buf, size);
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
+	u32 maxcount;
+
+	memset(listxattrs, 0, sizeof(*listxattrs));
+
+	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
+		return nfserr_bad_xdr;
+
+	/*
+	 * If the cookie  is too large to have even one user.x attribute
+	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
+	 */
+	if (listxattrs->lsxa_cookie >=
+	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
+		return nfserr_badcookie;
+
+	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (maxcount < 8)
+		/* Always need at least 2 words (length and one character) */
+		return nfserr_inval;
+
+	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
+	listxattrs->lsxa_maxcount = maxcount;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	memset(removexattr, 0, sizeof(*removexattr));
+	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
+}
+
+static __be32
+nfsd4_decode_noop(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
+{
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
+{
+	return nfserr_notsupp;
+}
+
+typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u);
+
+static const nfsd4_dec nfsd4_dec_ops[] = {
+	[OP_ACCESS]		= nfsd4_decode_access,
+	[OP_CLOSE]		= nfsd4_decode_close,
+	[OP_COMMIT]		= nfsd4_decode_commit,
+	[OP_CREATE]		= nfsd4_decode_create,
+	[OP_DELEGPURGE]		= nfsd4_decode_notsupp,
+	[OP_DELEGRETURN]	= nfsd4_decode_delegreturn,
+	[OP_GETATTR]		= nfsd4_decode_getattr,
+	[OP_GETFH]		= nfsd4_decode_noop,
+	[OP_LINK]		= nfsd4_decode_link,
+	[OP_LOCK]		= nfsd4_decode_lock,
+	[OP_LOCKT]		= nfsd4_decode_lockt,
+	[OP_LOCKU]		= nfsd4_decode_locku,
+	[OP_LOOKUP]		= nfsd4_decode_lookup,
+	[OP_LOOKUPP]		= nfsd4_decode_noop,
+	[OP_NVERIFY]		= nfsd4_decode_verify,
+	[OP_OPEN]		= nfsd4_decode_open,
+	[OP_OPENATTR]		= nfsd4_decode_notsupp,
+	[OP_OPEN_CONFIRM]	= nfsd4_decode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= nfsd4_decode_open_downgrade,
+	[OP_PUTFH]		= nfsd4_decode_putfh,
+	[OP_PUTPUBFH]		= nfsd4_decode_noop,
+	[OP_PUTROOTFH]		= nfsd4_decode_noop,
+	[OP_READ]		= nfsd4_decode_read,
+	[OP_READDIR]		= nfsd4_decode_readdir,
+	[OP_READLINK]		= nfsd4_decode_noop,
+	[OP_REMOVE]		= nfsd4_decode_remove,
+	[OP_RENAME]		= nfsd4_decode_rename,
+	[OP_RENEW]		= nfsd4_decode_renew,
+	[OP_RESTOREFH]		= nfsd4_decode_noop,
+	[OP_SAVEFH]		= nfsd4_decode_noop,
+	[OP_SECINFO]		= nfsd4_decode_secinfo,
+	[OP_SETATTR]		= nfsd4_decode_setattr,
+	[OP_SETCLIENTID]	= nfsd4_decode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = nfsd4_decode_setclientid_confirm,
+	[OP_VERIFY]		= nfsd4_decode_verify,
+	[OP_WRITE]		= nfsd4_decode_write,
+	[OP_RELEASE_LOCKOWNER]	= nfsd4_decode_release_lockowner,
+
+	/* new operations for NFSv4.1 */
+	[OP_BACKCHANNEL_CTL]	= nfsd4_decode_backchannel_ctl,
+	[OP_BIND_CONN_TO_SESSION] = nfsd4_decode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= nfsd4_decode_exchange_id,
+	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
+	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
+	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_get_dir_delegation,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= nfsd4_decode_layoutcommit,
+	[OP_LAYOUTGET]		= nfsd4_decode_layoutget,
+	[OP_LAYOUTRETURN]	= nfsd4_decode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= nfsd4_decode_notsupp,
+	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTGET]		= nfsd4_decode_notsupp,
+	[OP_LAYOUTRETURN]	= nfsd4_decode_notsupp,
+#endif
+	[OP_SECINFO_NO_NAME]	= nfsd4_decode_secinfo_no_name,
+	[OP_SEQUENCE]		= nfsd4_decode_sequence,
+	[OP_SET_SSV]		= nfsd4_decode_notsupp,
+	[OP_TEST_STATEID]	= nfsd4_decode_test_stateid,
+	[OP_WANT_DELEGATION]	= nfsd4_decode_notsupp,
+	[OP_DESTROY_CLIENTID]	= nfsd4_decode_destroy_clientid,
+	[OP_RECLAIM_COMPLETE]	= nfsd4_decode_reclaim_complete,
+
+	/* new operations for NFSv4.2 */
+	[OP_ALLOCATE]		= nfsd4_decode_fallocate,
+	[OP_COPY]		= nfsd4_decode_copy,
+	[OP_COPY_NOTIFY]	= nfsd4_decode_copy_notify,
+	[OP_DEALLOCATE]		= nfsd4_decode_fallocate,
+	[OP_IO_ADVISE]		= nfsd4_decode_notsupp,
+	[OP_LAYOUTERROR]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTSTATS]	= nfsd4_decode_notsupp,
+	[OP_OFFLOAD_CANCEL]	= nfsd4_decode_offload_status,
+	[OP_OFFLOAD_STATUS]	= nfsd4_decode_offload_status,
+	[OP_READ_PLUS]		= nfsd4_decode_read,
+	[OP_SEEK]		= nfsd4_decode_seek,
+	[OP_WRITE_SAME]		= nfsd4_decode_notsupp,
+	[OP_CLONE]		= nfsd4_decode_clone,
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= nfsd4_decode_getxattr,
+	[OP_SETXATTR]		= nfsd4_decode_setxattr,
+	[OP_LISTXATTRS]		= nfsd4_decode_listxattrs,
+	[OP_REMOVEXATTR]	= nfsd4_decode_removexattr,
+};
+
+static inline bool
+nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
+{
+	if (op->opnum < FIRST_NFS4_OP)
+		return false;
+	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
+		return false;
+	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
+		return false;
+	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
+		return false;
+	return true;
+}
+
+static bool
+nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
+{
+	struct nfsd_thread_local_info *ntli = argp->rqstp->rq_private;
+	struct nfsd4_op *op;
+	bool cachethis = false;
+	int auth_slack= argp->rqstp->rq_auth_slack;
+	int max_reply = auth_slack + 8; /* opcnt, status */
+	int readcount = 0;
+	int readbytes = 0;
+	__be32 *p;
+	int i;
+
+	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
+		return false;
+	max_reply += XDR_UNIT;
+	argp->tag = NULL;
+	if (unlikely(argp->taglen)) {
+		if (argp->taglen > NFSD4_MAX_TAGLEN)
+			return false;
+		p = xdr_inline_decode(argp->xdr, argp->taglen);
+		if (!p)
+			return false;
+		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
+		if (!argp->tag)
+			return false;
+		max_reply += xdr_align_size(argp->taglen);
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
+		return false;
+	if (xdr_stream_decode_u32(argp->xdr, &argp->client_opcnt) < 0)
+		return false;
+	argp->opcnt = min_t(u32, argp->client_opcnt,
+			    NFSD_MAX_OPS_PER_COMPOUND);
+
+	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
+		argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops));
+		if (!argp->ops) {
+			argp->ops = argp->iops;
+			return false;
+		}
+	}
+
+	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
+		argp->opcnt = 0;
+
+	for (i = 0; i < argp->opcnt; i++) {
+		op = &argp->ops[i];
+		op->replay = NULL;
+		op->opdesc = NULL;
+
+		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
+			return false;
+		if (nfsd4_opnum_in_range(argp, op)) {
+			op->opdesc = OPDESC(op);
+			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
+			if (op->status != nfs_ok)
+				trace_nfsd_compound_decode_err(argp->rqstp,
+							       argp->opcnt, i,
+							       op->opnum,
+							       op->status);
+		} else {
+			op->opnum = OP_ILLEGAL;
+			op->status = nfserr_op_illegal;
+		}
+
+		/*
+		 * We'll try to cache the result in the DRC if any one
+		 * op in the compound wants to be cached:
+		 */
+		cachethis |= nfsd4_cache_this_op(op);
+
+		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
+			readcount++;
+			readbytes += nfsd4_max_reply(argp->rqstp, op);
+		} else
+			max_reply += nfsd4_max_reply(argp->rqstp, op);
+		/*
+		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
+		 * (Special case because it will just skip encoding this
+		 * if it runs out of xdr buffer space, and it is the only
+		 * operation that behaves this way.)
+		 */
+		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
+			max_reply += NFS4_OPAQUE_LIMIT;
+
+		if (op->status) {
+			argp->opcnt = i+1;
+			break;
+		}
+	}
+	/* Sessions make the DRC unnecessary: */
+	if (argp->minorversion)
+		cachethis = false;
+	svc_reserve_auth(argp->rqstp, max_reply + readbytes);
+	ntli->ntli_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
+
+	argp->splice_ok = nfsd_read_splice_ok(argp->rqstp);
+	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
+		argp->splice_ok = false;
+
+	return true;
+}
+
+static __be32 nfsd4_encode_nfs_fh4(struct xdr_stream *xdr,
+				   const struct knfsd_fh *fh_handle)
+{
+	return nfsd4_encode_opaque(xdr, fh_handle->fh_raw, fh_handle->fh_size);
+}
+
+/* This is a frequently-encoded type; open-coded for speed */
+static __be32 nfsd4_encode_nfstime4(struct xdr_stream *xdr,
+				    const struct timespec64 *tv)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_hyper(p, tv->tv_sec);
+	*p = cpu_to_be32(tv->tv_nsec);
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_specdata4(struct xdr_stream *xdr,
+				     unsigned int major, unsigned int minor)
+{
+	__be32 status;
+
+	status = nfsd4_encode_uint32_t(xdr, major);
+	if (status != nfs_ok)
+		return status;
+	return nfsd4_encode_uint32_t(xdr, minor);
+}
+
+static __be32
+nfsd4_encode_change_info4(struct xdr_stream *xdr, const struct nfsd4_change_info *c)
+{
+	__be32 status;
+
+	status = nfsd4_encode_bool(xdr, c->atomic);
+	if (status != nfs_ok)
+		return status;
+	status = nfsd4_encode_changeid4(xdr, c->before_change);
+	if (status != nfs_ok)
+		return status;
+	return nfsd4_encode_changeid4(xdr, c->after_change);
+}
+
+static __be32 nfsd4_encode_netaddr4(struct xdr_stream *xdr,
+				    const struct nfs42_netaddr *addr)
+{
+	__be32 status;
+
+	/* na_r_netid */
+	status = nfsd4_encode_opaque(xdr, addr->netid, addr->netid_len);
+	if (status != nfs_ok)
+		return status;
+	/* na_r_addr */
+	return nfsd4_encode_opaque(xdr, addr->addr, addr->addr_len);
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep, escaped with esc_enter and esc_exit.
+ */
+static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
+					  char *components, char esc_enter,
+					  char esc_exit)
+{
+	__be32 *p;
+	__be32 pathlen;
+	int pathlen_offset;
+	char *str, *end, *next;
+	int count = 0;
+
+	pathlen_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	p++; /* We will fill this in with @count later */
+
+	end = str = components;
+	while (*end) {
+		bool found_esc = false;
+
+		/* try to parse as esc_start, ..., esc_end, sep */
+		if (*str == esc_enter) {
+			for (; *end && (*end != esc_exit); end++)
+				/* find esc_exit or end of string */;
+			next = end + 1;
+			if (*end && (!*next || *next == sep)) {
+				str++;
+				found_esc = true;
+			}
+		}
+
+		if (!found_esc)
+			for (; *end && (*end != sep); end++)
+				/* find sep or end of string */;
+
+		if (end > str) {
+			if (xdr_stream_encode_opaque(xdr, str, end - str) < 0)
+				return nfserr_resource;
+			count++;
+		} else
+			end++;
+		if (found_esc)
+			end = next;
+
+		str = end;
+	}
+	pathlen = htonl(count);
+	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
+	return 0;
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep.
+ */
+static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
+				      char *components)
+{
+	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
+}
+
+static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
+					struct nfsd4_fs_location *location)
+{
+	__be32 status;
+
+	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
+						'[', ']');
+	if (status)
+		return status;
+	status = nfsd4_encode_components(xdr, '/', location->path);
+	if (status)
+		return status;
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_pathname4(struct xdr_stream *xdr,
+				     const struct path *root,
+				     const struct path *path)
+{
+	struct path cur = *path;
+	struct dentry **components = NULL;
+	unsigned int ncomponents = 0;
+	__be32 err = nfserr_jukebox;
+
+	dprintk("nfsd4_encode_components(");
+
+	path_get(&cur);
+	/* First walk the path up to the nfsd root, and store the
+	 * dentries/path components in an array.
+	 */
+	for (;;) {
+		if (path_equal(&cur, root))
+			break;
+		if (cur.dentry == cur.mnt->mnt_root) {
+			if (follow_up(&cur))
+				continue;
+			goto out_free;
+		}
+		if ((ncomponents & 15) == 0) {
+			struct dentry **new;
+			new = krealloc(components,
+					sizeof(*new) * (ncomponents + 16),
+					GFP_KERNEL);
+			if (!new)
+				goto out_free;
+			components = new;
+		}
+		components[ncomponents++] = cur.dentry;
+		cur.dentry = dget_parent(cur.dentry);
+	}
+
+	err = nfserr_resource;
+	if (xdr_stream_encode_u32(xdr, ncomponents) != XDR_UNIT)
+		goto out_free;
+	while (ncomponents) {
+		struct dentry *dentry = components[ncomponents - 1];
+
+		spin_lock(&dentry->d_lock);
+		if (xdr_stream_encode_opaque(xdr, dentry->d_name.name,
+					     dentry->d_name.len) < 0) {
+			spin_unlock(&dentry->d_lock);
+			goto out_free;
+		}
+		dprintk("/%pd", dentry);
+		spin_unlock(&dentry->d_lock);
+		dput(dentry);
+		ncomponents--;
+	}
+
+	err = 0;
+out_free:
+	dprintk(")\n");
+	while (ncomponents)
+		dput(components[--ncomponents]);
+	kfree(components);
+	path_put(&cur);
+	return err;
+}
+
+static __be32 nfsd4_encode_fs_locations4(struct xdr_stream *xdr,
+					 struct svc_rqst *rqstp,
+					 struct svc_export *exp)
+{
+	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
+	struct svc_export *exp_ps;
+	unsigned int i;
+	__be32 status;
+
+	/* fs_root */
+	exp_ps = rqst_find_fsidzero_export(rqstp);
+	if (IS_ERR(exp_ps))
+		return nfserrno(PTR_ERR(exp_ps));
+	status = nfsd4_encode_pathname4(xdr, &exp_ps->ex_path, &exp->ex_path);
+	exp_put(exp_ps);
+	if (status != nfs_ok)
+		return status;
+
+	/* locations<> */
+	if (xdr_stream_encode_u32(xdr, fslocs->locations_count) != XDR_UNIT)
+		return nfserr_resource;
+	for (i = 0; i < fslocs->locations_count; i++) {
+		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
+		if (status != nfs_ok)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_nfsace4(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+				   struct nfs4_ace *ace)
+{
+	__be32 status;
+
+	/* type */
+	status = nfsd4_encode_acetype4(xdr, ace->type);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* flag */
+	status = nfsd4_encode_aceflag4(xdr, ace->flag);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* access mask */
+	status = nfsd4_encode_acemask4(xdr, ace->access_mask & NFS4_ACE_MASK_ALL);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* who */
+	if (ace->whotype != NFS4_ACL_WHO_NAMED)
+		return nfs4_acl_write_who(xdr, ace->whotype);
+	if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
+	return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
+}
+
+#define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
+			      FATTR4_WORD0_RDATTR_ERROR)
+#define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
+#define WORD2_ABSENT_FS_ATTRS 0
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    const struct lsm_context *context)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, context->len + 4 + 4 + 4);
+	if (!p)
+		return nfserr_resource;
+
+	/*
+	 * For now we use a 0 here to indicate the null translation; in
+	 * the future we may place a call to translation code here.
+	 */
+	*p++ = cpu_to_be32(0); /* lfs */
+	*p++ = cpu_to_be32(0); /* pi */
+	p = xdr_encode_opaque(p, context->context, context->len);
+	return 0;
+}
+#else
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    struct lsm_context *context)
+{ return 0; }
+#endif
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+
+static int nfsd4_posix_tagtotype(short tag)
+{
+	switch (tag) {
+	case ACL_USER_OBJ:	return POSIXACE4_TAG_USER_OBJ;
+	case ACL_GROUP_OBJ:	return POSIXACE4_TAG_GROUP_OBJ;
+	case ACL_USER:		return POSIXACE4_TAG_USER;
+	case ACL_GROUP:		return POSIXACE4_TAG_GROUP;
+	case ACL_MASK:		return POSIXACE4_TAG_MASK;
+	case ACL_OTHER:		return POSIXACE4_TAG_OTHER;
+	default:		return -EINVAL;
+	}
+}
+
+static __be32
+nfsd4_encode_posixace4(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+		       struct posix_acl_entry *acep)
+{
+	__be32 status;
+	int type;
+
+	type = nfsd4_posix_tagtotype(acep->e_tag);
+	if (type < 0)
+		return nfserr_resource;
+	if (!xdrgen_encode_posixacetag4(xdr, type))
+		return nfserr_resource;
+	if (!xdrgen_encode_posixaceperm4(xdr, acep->e_perm))
+		return nfserr_resource;
+
+	/* who */
+	switch (acep->e_tag) {
+	case ACL_USER_OBJ:
+	case ACL_GROUP_OBJ:
+	case ACL_MASK:
+	case ACL_OTHER:
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		break;
+	case ACL_USER:
+		status = nfsd4_encode_user(xdr, rqstp, acep->e_uid);
+		if (status != nfs_ok)
+			return status;
+		break;
+	case ACL_GROUP:
+		status = nfsd4_encode_group(xdr, rqstp, acep->e_gid);
+		if (status != nfs_ok)
+			return status;
+		break;
+	default:
+		return nfserr_resource;
+	}
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_posixacl(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+		      struct posix_acl *acl)
+{
+	__be32 status;
+	int i;
+
+	if (!acl) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+
+	if (acl->a_count > NFS_ACL_MAX_ENTRIES)
+		return nfserr_resource;
+	if (xdr_stream_encode_u32(xdr, acl->a_count) != XDR_UNIT)
+		return nfserr_resource;
+	for (i = 0; i < acl->a_count; i++) {
+		status = nfsd4_encode_posixace4(xdr, rqstp, &acl->a_entries[i]);
+		if (status != nfs_ok)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+#endif /* CONFIG_NFSD_V4_POSIX_ACL */
+
+static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
+{
+	/* As per referral draft:  */
+	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
+	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
+		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
+	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
+			*rdattr_err = NFSERR_MOVED;
+		else
+			return nfserr_moved;
+	}
+	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
+	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
+	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
+	return 0;
+}
+
+
+static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
+{
+	struct path path = exp->ex_path;
+	struct kstat stat;
+	int err;
+
+	path_get(&path);
+	while (follow_up(&path)) {
+		if (path.dentry != path.mnt->mnt_root)
+			break;
+	}
+	err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
+	path_put(&path);
+	if (!err)
+		*pino = stat.ino;
+	return err;
+}
+
+static __be32
+nfsd4_encode_bitmap4(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
+{
+	__be32 *p;
+
+	if (bmval2) {
+		p = xdr_reserve_space(xdr, XDR_UNIT * 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+		*p++ = cpu_to_be32(bmval2);
+	} else if (bmval1) {
+		p = xdr_reserve_space(xdr, XDR_UNIT * 3);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(2);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+	} else {
+		p = xdr_reserve_space(xdr, XDR_UNIT * 2);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+		*p++ = cpu_to_be32(bmval0);
+	}
+
+	return nfs_ok;
+out_resource:
+	return nfserr_resource;
+}
+
+struct nfsd4_fattr_args {
+	struct svc_rqst		*rqstp;
+	struct svc_export	*exp;
+	struct dentry		*dentry;
+	struct knfsd_fh		fhandle;
+	struct kstat		stat;
+	struct kstatfs		statfs;
+	struct nfs4_acl		*acl;
+	u64			change_attr;
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	struct lsm_context	context;
+#endif
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	struct posix_acl	*dpacl;
+	struct posix_acl	*pacl;
+#endif
+	u32			rdattr_err;
+	bool			contextsupport;
+	bool			ignore_crossmnt;
+	bool			case_insensitive;
+	bool			case_preserving;
+};
+
+typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr,
+				const struct nfsd4_fattr_args *args);
+
+static __be32 nfsd4_encode_fattr4__inval(struct xdr_stream *xdr,
+					 const struct nfsd4_fattr_args *args)
+{
+	return nfserr_inval;
+}
+
+static __be32 nfsd4_encode_fattr4__noop(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4__true(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, true);
+}
+
+static __be32 nfsd4_encode_fattr4__false(struct xdr_stream *xdr,
+					 const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, false);
+}
+
+static __be32 nfsd4_encode_fattr4_supported_attrs(struct xdr_stream *xdr,
+						  const struct nfsd4_fattr_args *args)
+{
+	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
+	u32 minorversion = resp->cstate.minorversion;
+	u32 supp[3];
+
+	memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
+	if (!IS_POSIXACL(d_inode(args->dentry)))
+		supp[0] &= ~FATTR4_WORD0_ACL;
+	if (!args->contextsupport)
+		supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
+	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
+}
+
+static __be32 nfsd4_encode_fattr4_type(struct xdr_stream *xdr,
+				       const struct nfsd4_fattr_args *args)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT);
+	if (!p)
+		return nfserr_resource;
+
+	switch (args->stat.mode & S_IFMT) {
+	case S_IFIFO:
+		*p = cpu_to_be32(NF4FIFO);
+		break;
+	case S_IFCHR:
+		*p = cpu_to_be32(NF4CHR);
+		break;
+	case S_IFDIR:
+		*p = cpu_to_be32(NF4DIR);
+		break;
+	case S_IFBLK:
+		*p = cpu_to_be32(NF4BLK);
+		break;
+	case S_IFLNK:
+		*p = cpu_to_be32(NF4LNK);
+		break;
+	case S_IFREG:
+		*p = cpu_to_be32(NF4REG);
+		break;
+	case S_IFSOCK:
+		*p = cpu_to_be32(NF4SOCK);
+		break;
+	default:
+		return nfserr_serverfault;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_fh_expire_type(struct xdr_stream *xdr,
+						 const struct nfsd4_fattr_args *args)
+{
+	u32 mask;
+
+	mask = NFS4_FH_PERSISTENT;
+	if (!(args->exp->ex_flags & NFSEXP_NOSUBTREECHECK))
+		mask |= NFS4_FH_VOL_RENAME;
+	return nfsd4_encode_uint32_t(xdr, mask);
+}
+
+static __be32 nfsd4_encode_fattr4_change(struct xdr_stream *xdr,
+					 const struct nfsd4_fattr_args *args)
+{
+	const struct svc_export *exp = args->exp;
+
+	if (exp && unlikely(exp->ex_flags & NFSEXP_V4ROOT)) {
+		u32 flush_time = convert_to_wallclock(exp->cd->flush_time);
+
+		if (xdr_stream_encode_u32(xdr, flush_time) != XDR_UNIT)
+			return nfserr_resource;
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+	return nfsd4_encode_changeid4(xdr, args->change_attr);
+}
+
+static __be32 nfsd4_encode_fattr4_size(struct xdr_stream *xdr,
+				       const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, args->stat.size);
+}
+
+static __be32 nfsd4_encode_fattr4_fsid(struct xdr_stream *xdr,
+				       const struct nfsd4_fattr_args *args)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 2 + XDR_UNIT * 2);
+	if (!p)
+		return nfserr_resource;
+
+	if (unlikely(args->exp->ex_fslocs.migrated)) {
+		p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
+		xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
+		return nfs_ok;
+	}
+	switch (fsid_source_fh(&args->fhandle, args->exp)) {
+	case FSIDSOURCE_FSID:
+		p = xdr_encode_hyper(p, (u64)args->exp->ex_fsid);
+		xdr_encode_hyper(p, (u64)0);
+		break;
+	case FSIDSOURCE_DEV:
+		*p++ = xdr_zero;
+		*p++ = cpu_to_be32(MAJOR(args->stat.dev));
+		*p++ = xdr_zero;
+		*p   = cpu_to_be32(MINOR(args->stat.dev));
+		break;
+	case FSIDSOURCE_UUID:
+		xdr_encode_opaque_fixed(p, args->exp->ex_uuid, EX_UUID_LEN);
+		break;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_lease_time(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(args->rqstp), nfsd_net_id);
+
+	return nfsd4_encode_nfs_lease4(xdr, nn->nfsd4_lease);
+}
+
+static __be32 nfsd4_encode_fattr4_rdattr_error(struct xdr_stream *xdr,
+					       const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint32_t(xdr, args->rdattr_err);
+}
+
+static __be32 nfsd4_encode_fattr4_aclsupport(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	u32 mask;
+
+	mask = 0;
+	if (IS_POSIXACL(d_inode(args->dentry)))
+		mask = ACL4_SUPPORT_ALLOW_ACL | ACL4_SUPPORT_DENY_ACL;
+	return nfsd4_encode_uint32_t(xdr, mask);
+}
+
+static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,
+				      const struct nfsd4_fattr_args *args)
+{
+	struct nfs4_acl *acl = args->acl;
+	struct nfs4_ace *ace;
+	__be32 status;
+
+	/* nfsace4<> */
+	if (!acl) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+	} else {
+		if (xdr_stream_encode_u32(xdr, acl->naces) != XDR_UNIT)
+			return nfserr_resource;
+		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
+			status = nfsd4_encode_nfsace4(xdr, args->rqstp, ace);
+			if (status != nfs_ok)
+				return status;
+		}
+	}
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_case_insensitive(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, args->case_insensitive);
+}
+
+static __be32 nfsd4_encode_fattr4_case_preserving(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, args->case_preserving);
+}
+
+static __be32 nfsd4_encode_fattr4_homogeneous(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	/*
+	 * Casefold-capable filesystems (e.g. ext4 or f2fs with the
+	 * casefold feature) attach a Unicode encoding at mount time
+	 * but apply case folding per directory.  The per-file-system
+	 * case_insensitive and case_preserving values can therefore
+	 * legitimately differ across objects that share the same fsid.
+	 * Report FATTR4_HOMOGENEOUS = FALSE on such filesystems to
+	 * keep that variation consistent with RFC 8881 Section 5.8.2.16.
+	 */
+	return nfsd4_encode_bool(xdr, !sb_has_encoding(args->dentry->d_sb));
+}
+
+static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_nfs_fh4(xdr, &args->fhandle);
+}
+
+static __be32 nfsd4_encode_fattr4_fileid(struct xdr_stream *xdr,
+					 const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, args->stat.ino);
+}
+
+static __be32 nfsd4_encode_fattr4_files_avail(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
+}
+
+static __be32 nfsd4_encode_fattr4_files_free(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
+}
+
+static __be32 nfsd4_encode_fattr4_files_total(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, args->statfs.f_files);
+}
+
+static __be32 nfsd4_encode_fattr4_fs_locations(struct xdr_stream *xdr,
+					       const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_fs_locations4(xdr, args->rqstp, args->exp);
+}
+
+static __be32 nfsd4_encode_fattr4_maxfilesize(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	struct super_block *sb = args->exp->ex_path.mnt->mnt_sb;
+
+	return nfsd4_encode_uint64_t(xdr, sb->s_maxbytes);
+}
+
+static __be32 nfsd4_encode_fattr4_maxlink(struct xdr_stream *xdr,
+					  const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint32_t(xdr, 255);
+}
+
+static __be32 nfsd4_encode_fattr4_maxname(struct xdr_stream *xdr,
+					  const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint32_t(xdr, args->statfs.f_namelen);
+}
+
+static __be32 nfsd4_encode_fattr4_maxread(struct xdr_stream *xdr,
+					  const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
+}
+
+static __be32 nfsd4_encode_fattr4_maxwrite(struct xdr_stream *xdr,
+					   const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
+}
+
+static __be32 nfsd4_encode_fattr4_mode(struct xdr_stream *xdr,
+				       const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_mode4(xdr, args->stat.mode & S_IALLUGO);
+}
+
+static __be32 nfsd4_encode_fattr4_numlinks(struct xdr_stream *xdr,
+					   const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint32_t(xdr, args->stat.nlink);
+}
+
+static __be32 nfsd4_encode_fattr4_owner(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_user(xdr, args->rqstp, args->stat.uid);
+}
+
+static __be32 nfsd4_encode_fattr4_owner_group(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_group(xdr, args->rqstp, args->stat.gid);
+}
+
+static __be32 nfsd4_encode_fattr4_rawdev(struct xdr_stream *xdr,
+					 const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_specdata4(xdr, MAJOR(args->stat.rdev),
+				      MINOR(args->stat.rdev));
+}
+
+static __be32 nfsd4_encode_fattr4_space_avail(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	u64 avail = (u64)args->statfs.f_bavail * (u64)args->statfs.f_bsize;
+
+	return nfsd4_encode_uint64_t(xdr, avail);
+}
+
+static __be32 nfsd4_encode_fattr4_space_free(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	u64 free = (u64)args->statfs.f_bfree * (u64)args->statfs.f_bsize;
+
+	return nfsd4_encode_uint64_t(xdr, free);
+}
+
+static __be32 nfsd4_encode_fattr4_space_total(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	u64 total = (u64)args->statfs.f_blocks * (u64)args->statfs.f_bsize;
+
+	return nfsd4_encode_uint64_t(xdr, total);
+}
+
+static __be32 nfsd4_encode_fattr4_space_used(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint64_t(xdr, (u64)args->stat.blocks << 9);
+}
+
+static __be32 nfsd4_encode_fattr4_time_access(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_nfstime4(xdr, &args->stat.atime);
+}
+
+static __be32 nfsd4_encode_fattr4_time_create(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_nfstime4(xdr, &args->stat.btime);
+}
+
+/*
+ * ctime (in NFSv4, time_metadata) is not writeable, and the client
+ * doesn't really care what resolution could theoretically be stored by
+ * the filesystem.
+ *
+ * The client cares how close together changes can be while still
+ * guaranteeing ctime changes.  For most filesystems (which have
+ * timestamps with nanosecond fields) that is limited by the resolution
+ * of the time returned from current_time() (which I'm assuming to be
+ * 1/HZ).
+ */
+static __be32 nfsd4_encode_fattr4_time_delta(struct xdr_stream *xdr,
+					     const struct nfsd4_fattr_args *args)
+{
+	const struct inode *inode = d_inode(args->dentry);
+	u32 ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
+	struct timespec64 ts = ns_to_timespec64(ns);
+
+	return nfsd4_encode_nfstime4(xdr, &ts);
+}
+
+static __be32 nfsd4_encode_fattr4_time_metadata(struct xdr_stream *xdr,
+						const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_nfstime4(xdr, &args->stat.ctime);
+}
+
+static __be32 nfsd4_encode_fattr4_time_modify(struct xdr_stream *xdr,
+					      const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_nfstime4(xdr, &args->stat.mtime);
+}
+
+static __be32 nfsd4_encode_fattr4_mounted_on_fileid(struct xdr_stream *xdr,
+						    const struct nfsd4_fattr_args *args)
+{
+	u64 ino;
+	int err;
+
+	if (!args->ignore_crossmnt &&
+	    args->dentry == args->exp->ex_path.mnt->mnt_root) {
+		err = nfsd4_get_mounted_on_ino(args->exp, &ino);
+		if (err)
+			return nfserrno(err);
+	} else
+		ino = args->stat.ino;
+
+	return nfsd4_encode_uint64_t(xdr, ino);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+
+static __be32 nfsd4_encode_fattr4_fs_layout_types(struct xdr_stream *xdr,
+						  const struct nfsd4_fattr_args *args)
+{
+	unsigned long mask = args->exp->ex_layout_types;
+	int i;
+
+	/* Hamming weight of @mask is the number of layout types to return */
+	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
+		return nfserr_resource;
+	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
+		if (mask & BIT(i)) {
+			/* layouttype4 */
+			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
+				return nfserr_resource;
+		}
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_layout_types(struct xdr_stream *xdr,
+					       const struct nfsd4_fattr_args *args)
+{
+	unsigned long mask = args->exp->ex_layout_types;
+	int i;
+
+	/* Hamming weight of @mask is the number of layout types to return */
+	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
+		return nfserr_resource;
+	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
+		if (mask & BIT(i)) {
+			/* layouttype4 */
+			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
+				return nfserr_resource;
+		}
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_layout_blksize(struct xdr_stream *xdr,
+						 const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_uint32_t(xdr, args->stat.blksize);
+}
+
+#endif
+
+static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr,
+						     const struct nfsd4_fattr_args *args)
+{
+	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
+	u32 supp[3];
+
+	memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp));
+	if (!IS_POSIXACL(d_inode(args->dentry)))
+		supp[0] &= ~FATTR4_WORD0_ACL;
+	if (!args->contextsupport)
+		supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
+	supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
+	supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
+	supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
+
+	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
+}
+
+/*
+ * Copied from generic_remap_checks/generic_remap_file_range_prep.
+ *
+ * These generic functions use the file system's s_blocksize, but
+ * individual file systems aren't required to use
+ * generic_remap_file_range_prep. Until there is a mechanism for
+ * determining a particular file system's (or file's) clone block
+ * size, this is the best NFSD can do.
+ */
+static __be32 nfsd4_encode_fattr4_clone_blksize(struct xdr_stream *xdr,
+						const struct nfsd4_fattr_args *args)
+{
+	struct inode *inode = d_inode(args->dentry);
+
+	return nfsd4_encode_uint32_t(xdr, inode->i_sb->s_blocksize);
+}
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static __be32 nfsd4_encode_fattr4_sec_label(struct xdr_stream *xdr,
+					    const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_security_label(xdr, args->rqstp, &args->context);
+}
+#endif
+
+static __be32 nfsd4_encode_fattr4_xattr_support(struct xdr_stream *xdr,
+						const struct nfsd4_fattr_args *args)
+{
+	int err = xattr_supports_user_prefix(d_inode(args->dentry));
+
+	return nfsd4_encode_bool(xdr, err == 0);
+}
+
+#define NFSD_OA_SHARE_ACCESS	(BIT(OPEN_ARGS_SHARE_ACCESS_READ)	| \
+				 BIT(OPEN_ARGS_SHARE_ACCESS_WRITE)	| \
+				 BIT(OPEN_ARGS_SHARE_ACCESS_BOTH))
+
+#define NFSD_OA_SHARE_DENY	(BIT(OPEN_ARGS_SHARE_DENY_NONE)		| \
+				 BIT(OPEN_ARGS_SHARE_DENY_READ)		| \
+				 BIT(OPEN_ARGS_SHARE_DENY_WRITE)	| \
+				 BIT(OPEN_ARGS_SHARE_DENY_BOTH))
+
+#define NFSD_OA_SHARE_ACCESS_WANT	(BIT(OPEN_ARGS_SHARE_ACCESS_WANT_ANY_DELEG)		| \
+					 BIT(OPEN_ARGS_SHARE_ACCESS_WANT_NO_DELEG)		| \
+					 BIT(OPEN_ARGS_SHARE_ACCESS_WANT_CANCEL)		| \
+					 BIT(OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS)	| \
+					 BIT(OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION))
+
+#define NFSD_OA_OPEN_CLAIM	(BIT(OPEN_ARGS_OPEN_CLAIM_NULL)		| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_PREVIOUS)	| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_DELEGATE_CUR)	| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_DELEGATE_PREV)| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_FH)		| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_DELEG_CUR_FH)	| \
+				 BIT(OPEN_ARGS_OPEN_CLAIM_DELEG_PREV_FH))
+
+#define NFSD_OA_CREATE_MODE	(BIT(OPEN_ARGS_CREATEMODE_UNCHECKED4)	| \
+				 BIT(OPEN_ARGS_CREATE_MODE_GUARDED)	| \
+				 BIT(OPEN_ARGS_CREATEMODE_EXCLUSIVE4)	| \
+				 BIT(OPEN_ARGS_CREATE_MODE_EXCLUSIVE4_1))
+
+static uint32_t oa_share_access = NFSD_OA_SHARE_ACCESS;
+static uint32_t oa_share_deny = NFSD_OA_SHARE_DENY;
+static uint32_t oa_share_access_want = NFSD_OA_SHARE_ACCESS_WANT;
+static uint32_t oa_open_claim = NFSD_OA_OPEN_CLAIM;
+static uint32_t oa_create_mode = NFSD_OA_CREATE_MODE;
+
+static const struct open_arguments4 nfsd_open_arguments = {
+	.oa_share_access = { .count = 1, .element = &oa_share_access },
+	.oa_share_deny = { .count = 1, .element = &oa_share_deny },
+	.oa_share_access_want = { .count = 1, .element = &oa_share_access_want },
+	.oa_open_claim = { .count = 1, .element = &oa_open_claim },
+	.oa_create_mode = { .count = 1, .element = &oa_create_mode },
+};
+
+static __be32 nfsd4_encode_fattr4_open_arguments(struct xdr_stream *xdr,
+						 const struct nfsd4_fattr_args *args)
+{
+	if (!xdrgen_encode_fattr4_open_arguments(xdr, &nfsd_open_arguments))
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+
+static __be32 nfsd4_encode_fattr4_acl_trueform(struct xdr_stream *xdr,
+					       const struct nfsd4_fattr_args *args)
+{
+	aclmodel4 trueform = ACL_MODEL_NONE;
+
+	if (IS_POSIXACL(d_inode(args->dentry)))
+		trueform = ACL_MODEL_POSIX_DRAFT;
+	if (!xdrgen_encode_aclmodel4(xdr, trueform))
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_acl_trueform_scope(struct xdr_stream *xdr,
+						     const struct nfsd4_fattr_args *args)
+{
+	if (!xdrgen_encode_aclscope4(xdr, ACL_SCOPE_FILE_SYSTEM))
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+static __be32 nfsd4_encode_fattr4_posix_default_acl(struct xdr_stream *xdr,
+						    const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_posixacl(xdr, args->rqstp, args->dpacl);
+}
+
+static __be32 nfsd4_encode_fattr4_posix_access_acl(struct xdr_stream *xdr,
+						   const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_posixacl(xdr, args->rqstp, args->pacl);
+}
+
+#endif /* CONFIG_NFSD_V4_POSIX_ACLS */
+
+static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {
+	[FATTR4_SUPPORTED_ATTRS]	= nfsd4_encode_fattr4_supported_attrs,
+	[FATTR4_TYPE]			= nfsd4_encode_fattr4_type,
+	[FATTR4_FH_EXPIRE_TYPE]		= nfsd4_encode_fattr4_fh_expire_type,
+	[FATTR4_CHANGE]			= nfsd4_encode_fattr4_change,
+	[FATTR4_SIZE]			= nfsd4_encode_fattr4_size,
+	[FATTR4_LINK_SUPPORT]		= nfsd4_encode_fattr4__true,
+	[FATTR4_SYMLINK_SUPPORT]	= nfsd4_encode_fattr4__true,
+	[FATTR4_NAMED_ATTR]		= nfsd4_encode_fattr4__false,
+	[FATTR4_FSID]			= nfsd4_encode_fattr4_fsid,
+	[FATTR4_UNIQUE_HANDLES]		= nfsd4_encode_fattr4__true,
+	[FATTR4_LEASE_TIME]		= nfsd4_encode_fattr4_lease_time,
+	[FATTR4_RDATTR_ERROR]		= nfsd4_encode_fattr4_rdattr_error,
+	[FATTR4_ACL]			= nfsd4_encode_fattr4_acl,
+	[FATTR4_ACLSUPPORT]		= nfsd4_encode_fattr4_aclsupport,
+	[FATTR4_ARCHIVE]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_CANSETTIME]		= nfsd4_encode_fattr4__true,
+	[FATTR4_CASE_INSENSITIVE]	= nfsd4_encode_fattr4_case_insensitive,
+	[FATTR4_CASE_PRESERVING]	= nfsd4_encode_fattr4_case_preserving,
+	[FATTR4_CHOWN_RESTRICTED]	= nfsd4_encode_fattr4__true,
+	[FATTR4_FILEHANDLE]		= nfsd4_encode_fattr4_filehandle,
+	[FATTR4_FILEID]			= nfsd4_encode_fattr4_fileid,
+	[FATTR4_FILES_AVAIL]		= nfsd4_encode_fattr4_files_avail,
+	[FATTR4_FILES_FREE]		= nfsd4_encode_fattr4_files_free,
+	[FATTR4_FILES_TOTAL]		= nfsd4_encode_fattr4_files_total,
+	[FATTR4_FS_LOCATIONS]		= nfsd4_encode_fattr4_fs_locations,
+	[FATTR4_HIDDEN]			= nfsd4_encode_fattr4__noop,
+	[FATTR4_HOMOGENEOUS]		= nfsd4_encode_fattr4_homogeneous,
+	[FATTR4_MAXFILESIZE]		= nfsd4_encode_fattr4_maxfilesize,
+	[FATTR4_MAXLINK]		= nfsd4_encode_fattr4_maxlink,
+	[FATTR4_MAXNAME]		= nfsd4_encode_fattr4_maxname,
+	[FATTR4_MAXREAD]		= nfsd4_encode_fattr4_maxread,
+	[FATTR4_MAXWRITE]		= nfsd4_encode_fattr4_maxwrite,
+	[FATTR4_MIMETYPE]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_MODE]			= nfsd4_encode_fattr4_mode,
+	[FATTR4_NO_TRUNC]		= nfsd4_encode_fattr4__true,
+	[FATTR4_NUMLINKS]		= nfsd4_encode_fattr4_numlinks,
+	[FATTR4_OWNER]			= nfsd4_encode_fattr4_owner,
+	[FATTR4_OWNER_GROUP]		= nfsd4_encode_fattr4_owner_group,
+	[FATTR4_QUOTA_AVAIL_HARD]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_QUOTA_AVAIL_SOFT]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_QUOTA_USED]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RAWDEV]			= nfsd4_encode_fattr4_rawdev,
+	[FATTR4_SPACE_AVAIL]		= nfsd4_encode_fattr4_space_avail,
+	[FATTR4_SPACE_FREE]		= nfsd4_encode_fattr4_space_free,
+	[FATTR4_SPACE_TOTAL]		= nfsd4_encode_fattr4_space_total,
+	[FATTR4_SPACE_USED]		= nfsd4_encode_fattr4_space_used,
+	[FATTR4_SYSTEM]			= nfsd4_encode_fattr4__noop,
+	[FATTR4_TIME_ACCESS]		= nfsd4_encode_fattr4_time_access,
+	[FATTR4_TIME_ACCESS_SET]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_TIME_BACKUP]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_TIME_CREATE]		= nfsd4_encode_fattr4_time_create,
+	[FATTR4_TIME_DELTA]		= nfsd4_encode_fattr4_time_delta,
+	[FATTR4_TIME_METADATA]		= nfsd4_encode_fattr4_time_metadata,
+	[FATTR4_TIME_MODIFY]		= nfsd4_encode_fattr4_time_modify,
+	[FATTR4_TIME_MODIFY_SET]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_MOUNTED_ON_FILEID]	= nfsd4_encode_fattr4_mounted_on_fileid,
+	[FATTR4_DIR_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_DIRENT_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_DACL]			= nfsd4_encode_fattr4__noop,
+	[FATTR4_SACL]			= nfsd4_encode_fattr4__noop,
+	[FATTR4_CHANGE_POLICY]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_FS_STATUS]		= nfsd4_encode_fattr4__noop,
+
+#ifdef CONFIG_NFSD_PNFS
+	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4_fs_layout_types,
+	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4_layout_types,
+	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4_layout_blksize,
+	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
+#else
+	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
+#endif
+
+	[FATTR4_FS_LOCATIONS_INFO]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_MDSTHRESHOLD]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RETENTION_GET]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RETENTION_SET]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RETENTEVT_GET]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RETENTEVT_SET]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_RETENTION_HOLD]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_MODE_SET_MASKED]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_SUPPATTR_EXCLCREAT]	= nfsd4_encode_fattr4_suppattr_exclcreat,
+	[FATTR4_FS_CHARSET_CAP]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_CLONE_BLKSIZE]		= nfsd4_encode_fattr4_clone_blksize,
+	[FATTR4_SPACE_FREED]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_CHANGE_ATTR_TYPE]	= nfsd4_encode_fattr4__noop,
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4_sec_label,
+#else
+	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4__noop,
+#endif
+
+	[FATTR4_MODE_UMASK]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_XATTR_SUPPORT]		= nfsd4_encode_fattr4_xattr_support,
+	[FATTR4_TIME_DELEG_ACCESS]	= nfsd4_encode_fattr4__inval,
+	[FATTR4_TIME_DELEG_MODIFY]	= nfsd4_encode_fattr4__inval,
+	[FATTR4_OPEN_ARGUMENTS]		= nfsd4_encode_fattr4_open_arguments,
+
+	/* Reserved */
+	[87]				= nfsd4_encode_fattr4__inval,
+	[88]				= nfsd4_encode_fattr4__inval,
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	[FATTR4_ACL_TRUEFORM]		= nfsd4_encode_fattr4_acl_trueform,
+	[FATTR4_ACL_TRUEFORM_SCOPE]	= nfsd4_encode_fattr4_acl_trueform_scope,
+	[FATTR4_POSIX_DEFAULT_ACL]	= nfsd4_encode_fattr4_posix_default_acl,
+	[FATTR4_POSIX_ACCESS_ACL]	= nfsd4_encode_fattr4_posix_access_acl,
+#else
+	[FATTR4_ACL_TRUEFORM]		= nfsd4_encode_fattr4__noop,
+	[FATTR4_ACL_TRUEFORM_SCOPE]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_POSIX_DEFAULT_ACL]	= nfsd4_encode_fattr4__noop,
+	[FATTR4_POSIX_ACCESS_ACL]	= nfsd4_encode_fattr4__noop,
+#endif
+};
+
+static __be32
+nfsd4_encode_attr_vals(struct xdr_stream *xdr, u32 *attrmask, struct nfsd4_fattr_args *args)
+{
+	DECLARE_BITMAP(attr_bitmap, ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops));
+	unsigned long bit;
+	__be32 status;
+
+	bitmap_from_arr32(attr_bitmap, attrmask, ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops));
+	for_each_set_bit(bit, attr_bitmap, ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops)) {
+		status = nfsd4_enc_fattr4_encode_ops[bit](xdr, args);
+		if (status != nfs_ok)
+			return status;
+	}
+	return nfs_ok;
+}
+
+/*
+ * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
+ * ourselves. @case_cache is NULL for callers that encode a single dentry
+ * (GETATTR, the buffer wrapper); READDIR passes a per-request cache so
+ * non-directory children share the parent's case-folding probe result.
+ */
+static __be32
+nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		    struct svc_fh *fhp, struct svc_export *exp,
+		    struct dentry *dentry, const u32 *bmval,
+		    int ignore_crossmnt,
+		    struct nfsd_case_attrs_cache *case_cache)
+{
+	struct nfs4_delegation *dp = NULL;
+	struct nfsd4_fattr_args args;
+	struct svc_fh *tempfh = NULL;
+	int starting_len = xdr->buf->len;
+	unsigned int attrlen_offset;
+	__be32 attrlen, status;
+	u32 attrmask[3];
+	int err;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	u32 minorversion = resp->cstate.minorversion;
+	struct path path = {
+		.mnt	= exp->ex_path.mnt,
+		.dentry	= dentry,
+	};
+
+	WARN_ON_ONCE(bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1);
+	WARN_ON_ONCE(!nfsd_attrs_supported(minorversion, bmval));
+
+	args.rqstp = rqstp;
+	args.exp = exp;
+	args.dentry = dentry;
+	args.ignore_crossmnt = (ignore_crossmnt != 0);
+	args.acl = NULL;
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	args.context.context = NULL;
+#endif
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	args.dpacl = NULL;
+	args.pacl = NULL;
+#endif
+
+	/*
+	 * Make a local copy of the attribute bitmap that can be modified.
+	 */
+	attrmask[0] = bmval[0];
+	attrmask[1] = bmval[1];
+	attrmask[2] = bmval[2];
+
+	args.rdattr_err = 0;
+	if (exp->ex_fslocs.migrated) {
+		status = fattr_handle_absent_fs(&attrmask[0], &attrmask[1],
+						&attrmask[2], &args.rdattr_err);
+		if (status)
+			goto out;
+	}
+	if ((attrmask[0] & (FATTR4_WORD0_CHANGE |
+			    FATTR4_WORD0_SIZE)) ||
+	    (attrmask[1] & (FATTR4_WORD1_TIME_ACCESS |
+			    FATTR4_WORD1_TIME_MODIFY |
+			    FATTR4_WORD1_TIME_METADATA))) {
+		status = nfsd4_deleg_getattr_conflict(rqstp, dentry, &dp);
+		if (status)
+			goto out;
+	}
+
+	err = vfs_getattr(&path, &args.stat,
+			  STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
+			  AT_STATX_SYNC_AS_STAT);
+	if (dp) {
+		struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
+
+		if (ncf->ncf_file_modified) {
+			++ncf->ncf_initial_cinfo;
+			args.stat.size = ncf->ncf_cur_fsize;
+			if (!timespec64_is_epoch(&ncf->ncf_cb_mtime))
+				args.stat.mtime = ncf->ncf_cb_mtime;
+		}
+		args.change_attr = ncf->ncf_initial_cinfo;
+
+		if (!timespec64_is_epoch(&ncf->ncf_cb_atime))
+			args.stat.atime = ncf->ncf_cb_atime;
+
+		nfs4_put_stid(&dp->dl_stid);
+	} else {
+		args.change_attr = nfsd4_change_attribute(&args.stat);
+	}
+
+	if (err)
+		goto out_nfserr;
+
+	if (!(args.stat.result_mask & STATX_BTIME))
+		/* underlying FS does not offer btime so we can't share it */
+		attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
+	if ((attrmask[0] & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
+			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
+	    (attrmask[1] & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
+		       FATTR4_WORD1_SPACE_TOTAL))) {
+		err = vfs_statfs(&path, &args.statfs);
+		if (err)
+			goto out_nfserr;
+	}
+
+	if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID))) {
+		if (!fhp) {
+			tempfh = kmalloc_obj(struct svc_fh);
+			status = nfserr_jukebox;
+			if (!tempfh)
+				goto out;
+			fh_init(tempfh, NFS4_FHSIZE);
+			status = fh_compose(tempfh, exp, dentry, NULL);
+			if (status)
+				goto out;
+			fhp = tempfh;
+		}
+		fh_copy_shallow(&args.fhandle, &fhp->fh_handle);
+	}
+
+	if (attrmask[0] & (FATTR4_WORD0_CASE_INSENSITIVE |
+			   FATTR4_WORD0_CASE_PRESERVING)) {
+		/*
+		 * In a batched encoder (READDIR) every non-directory
+		 * child shares the same case-folding answer, so the
+		 * directory being read is probed once and the result is
+		 * cached. The probe targets case_cache->dir, the held
+		 * readdir filehandle's dentry, instead of the child's
+		 * locklessly-acquired dentry, which a concurrent rename
+		 * could move under an unrelated parent. Directory
+		 * entries are queried directly because casefold-capable
+		 * filesystems answer per directory.
+		 *
+		 * Per RFC 8881 Section 18.7.3, an attribute advertised
+		 * in SUPPORTED_ATTRS must come back with a value or the
+		 * GETATTR must fail. nfsd_get_case_info() fills POSIX
+		 * defaults and returns -EOPNOTSUPP when the underlying
+		 * filesystem does not expose case state; encode those
+		 * defaults so the reply agrees with what SUPPORTED_ATTRS
+		 * advertises. Other errors fail the operation as the
+		 * spec requires.
+		 */
+		if (case_cache && !d_is_dir(dentry)) {
+			if (!case_cache->valid) {
+				err = nfsd_get_case_info(case_cache->dir,
+							 &case_cache->insensitive,
+							 &case_cache->preserving);
+				if (err && err != -EOPNOTSUPP)
+					goto out_nfserr;
+				case_cache->valid = true;
+			}
+			args.case_insensitive = case_cache->insensitive;
+			args.case_preserving = case_cache->preserving;
+		} else {
+			err = nfsd_get_case_info(dentry,
+						 &args.case_insensitive,
+						 &args.case_preserving);
+			if (err && err != -EOPNOTSUPP)
+				goto out_nfserr;
+		}
+	}
+
+	if (attrmask[0] & FATTR4_WORD0_ACL) {
+		err = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);
+		if (err == -EOPNOTSUPP)
+			attrmask[0] &= ~FATTR4_WORD0_ACL;
+		else if (err == -EINVAL) {
+			status = nfserr_attrnotsupp;
+			goto out;
+		} else if (err != 0)
+			goto out_nfserr;
+	}
+
+	args.contextsupport = false;
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if ((attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) ||
+	     attrmask[0] & FATTR4_WORD0_SUPPORTED_ATTRS) {
+		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
+			err = security_inode_getsecctx(d_inode(dentry),
+						&args.context);
+		else
+			err = -EOPNOTSUPP;
+		args.contextsupport = (err == 0);
+		if (attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) {
+			if (err == -EOPNOTSUPP)
+				attrmask[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+			else if (err)
+				goto out_nfserr;
+		}
+	}
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	if (attrmask[2] & FATTR4_WORD2_POSIX_DEFAULT_ACL) {
+		struct inode *inode = d_inode(dentry);
+		struct posix_acl *dpacl;
+
+		if (S_ISDIR(inode->i_mode)) {
+			dpacl = get_inode_acl(inode, ACL_TYPE_DEFAULT);
+			if (IS_ERR(dpacl)) {
+				switch (PTR_ERR(dpacl)) {
+				case -EOPNOTSUPP:
+					attrmask[2] &= ~FATTR4_WORD2_POSIX_DEFAULT_ACL;
+					break;
+				case -EINVAL:
+					status = nfserr_attrnotsupp;
+					goto out;
+				default:
+					err = PTR_ERR(dpacl);
+					goto out_nfserr;
+				}
+			} else {
+				args.dpacl = dpacl;
+			}
+		}
+	}
+	if (attrmask[2] & FATTR4_WORD2_POSIX_ACCESS_ACL) {
+		struct inode *inode = d_inode(dentry);
+		struct posix_acl *pacl;
+
+		pacl = get_inode_acl(inode, ACL_TYPE_ACCESS);
+		if (!pacl)
+			pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		if (IS_ERR(pacl)) {
+			switch (PTR_ERR(pacl)) {
+			case -EOPNOTSUPP:
+				attrmask[2] &= ~FATTR4_WORD2_POSIX_ACCESS_ACL;
+				break;
+			case -EINVAL:
+				status = nfserr_attrnotsupp;
+				goto out;
+			default:
+				err = PTR_ERR(pacl);
+				goto out_nfserr;
+			}
+		} else {
+			args.pacl = pacl;
+		}
+	}
+#endif /* CONFIG_NFSD_V4_POSIX_ACLS */
+
+	/* attrmask */
+	status = nfsd4_encode_bitmap4(xdr, attrmask[0], attrmask[1], attrmask[2]);
+	if (status)
+		goto out;
+
+	/* attr_vals */
+	attrlen_offset = xdr->buf->len;
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT))) {
+		status = nfserr_resource;
+		goto out;
+	}
+
+	status = nfsd4_encode_attr_vals(xdr, attrmask, &args);
+	if (status == nfs_ok) {
+		attrlen = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
+		write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, XDR_UNIT);
+	}
+out:
+#ifdef CONFIG_NFSD_V4_POSIX_ACLS
+	if (args.dpacl)
+		posix_acl_release(args.dpacl);
+	if (args.pacl)
+		posix_acl_release(args.pacl);
+#endif /* CONFIG_NFSD_V4_POSIX_ACLS */
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (args.context.context)
+		security_release_secctx(&args.context);
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+	kfree(args.acl);
+	if (tempfh) {
+		fh_put(tempfh);
+		kfree(tempfh);
+	}
+	if (status)
+		xdr_truncate_encode(xdr, starting_len);
+	return status;
+out_nfserr:
+	status = nfserrno(err);
+	goto out;
+}
+
+static bool
+setup_notify_fhandle(struct dentry *dentry, struct nfs4_delegation *dp,
+		     struct nfsd_file *nf, struct nfsd4_fattr_args *args)
+{
+	struct nfs4_file *fi = dp->dl_stid.sc_file;
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+	int fileid_type, fsid_len, maxsize, flags = 0;
+	struct knfsd_fh *fhp = &args->fhandle;
+	struct inode *inode = d_inode(dentry);
+	struct inode *parent = NULL;
+	struct svc_export *exp;
+	struct fid *fid;
+	bool ret = false;
+
+	/*
+	 * drop_stid_export() can clear sc_export under cl_lock and drop its
+	 * reference when the delegation is admin-revoked, concurrently with
+	 * this callback. Grab our own reference under cl_lock so the export
+	 * can be neither NULL-raced nor freed while we encode.
+	 */
+	spin_lock(&clp->cl_lock);
+	exp = dp->dl_stid.sc_export;
+	if (exp)
+		exp_get(exp);
+	spin_unlock(&clp->cl_lock);
+
+	fsid_len = key_len(fi->fi_fhandle.fh_fsid_type);
+	fhp->fh_size = 4 + fsid_len;
+
+	/* Copy first 4 bytes + fsid */
+	memcpy(&fhp->fh_raw, &fi->fi_fhandle.fh_raw, fhp->fh_size);
+
+	fid = (struct fid *)(fh_fsid(fhp) + fsid_len/4);
+	maxsize = (NFS4_FHSIZE - fhp->fh_size)/4;
+
+	/*
+	 * Subtree-checking exports need a connectable filehandle so the
+	 * parent can be resolved at decode time. Derive this from the
+	 * delegation's export rather than the shared nfs4_file, which may
+	 * have been initialized under a different export.
+	 */
+	if (exp && !(exp->ex_flags & NFSEXP_NOSUBTREECHECK) &&
+	    !S_ISDIR(inode->i_mode)) {
+		parent = d_inode(nf->nf_file->f_path.dentry);
+		flags = EXPORT_FH_CONNECTABLE;
+	}
+
+	fileid_type = exportfs_encode_inode_fh(inode, fid, &maxsize, parent, flags);
+	if (fileid_type < 0 || fileid_type == FILEID_INVALID)
+		goto out;
+
+	fhp->fh_fileid_type = fileid_type;
+	fhp->fh_size += maxsize * 4;
+
+	if (exp && (exp->ex_flags & NFSEXP_SIGN_FH))
+		if (!fh_append_mac(fhp, NFS4_FHSIZE, exp->cd->net))
+			goto out;
+
+	ret = true;
+out:
+	if (exp)
+		exp_put(exp);
+	return ret;
+}
+
+#define CB_NOTIFY_STATX_REQUEST_MASK (STATX_BASIC_STATS   | \
+				      STATX_BTIME	  | \
+				      STATX_CHANGE_COOKIE)
+
+static bool
+nfsd4_setup_notify_entry4(struct notify_entry4 *ne, struct xdr_stream *xdr,
+			  struct dentry *dentry, struct nfs4_delegation *dp,
+			  struct nfsd_file *nf, char *name, u32 namelen)
+{
+	struct path path = nf->nf_file->f_path;
+	struct nfsd4_fattr_args args = { };
+	const u32 *reqmask;
+	uint32_t *attrmask;
+	__be32 status;
+	bool parent;
+	int ret;
+
+	/* Reserve space for attrmask */
+	attrmask = xdr_reserve_space(xdr, 3 * sizeof(uint32_t));
+	if (!attrmask)
+		return false;
+
+	ne->ne_file.data = name;
+	ne->ne_file.len = namelen;
+	ne->ne_attrs.attrmask.element = attrmask;
+
+	parent = (dentry == path.dentry);
+	path.dentry = dentry;
+	reqmask = parent ? dp->dl_dir_attrs : dp->dl_child_attrs;
+
+	/*
+	 * A NULL or negative dentry has no attributes to report (expected,
+	 * e.g. for the old entry of a rename or an entry already removed).
+	 * The client may also have been granted the notification while
+	 * requesting no attributes for this entry. Both cases encode an
+	 * empty attribute set rather than failing: the vfs_getattr() and
+	 * nfsd4_encode_attr_vals() failures below recall the delegation, so
+	 * a case with nothing to fetch must short-circuit ahead of them.
+	 */
+	if (!path.dentry || !d_inode(path.dentry) ||
+	    (!reqmask[0] && !reqmask[1])) {
+		attrmask[0] = 0;
+		attrmask[1] = 0;
+		attrmask[2] = 0;
+		ne->ne_attrs.attr_vals.data = NULL;
+		ne->ne_attrs.attr_vals.len = 0;
+		ne->ne_attrs.attrmask.count = 1;
+		return true;
+	}
+
+	/*
+	 * It is possible that the client was granted a delegation when a file
+	 * was created. Note that we don't issue a CB_GETATTR here since stale
+	 * attributes are presumably ok.
+	 */
+	ret = vfs_getattr(&path, &args.stat, CB_NOTIFY_STATX_REQUEST_MASK, AT_STATX_SYNC_AS_STAT);
+	if (ret)
+		return false;
+
+	args.change_attr = nfsd4_change_attribute(&args.stat);
+
+	if (parent) {
+		attrmask[0] = dp->dl_dir_attrs[0];
+		attrmask[1] = dp->dl_dir_attrs[1];
+	} else {
+		attrmask[0] = dp->dl_child_attrs[0];
+		attrmask[1] = dp->dl_child_attrs[1];
+
+		if (!setup_notify_fhandle(dentry, dp, nf, &args))
+			attrmask[0] &= ~FATTR4_WORD0_FILEHANDLE;
+
+		if (!(args.stat.result_mask & STATX_BTIME))
+			attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
+	}
+	attrmask[2] = 0;
+
+	ne->ne_attrs.attrmask.count = 2;
+	ne->ne_attrs.attr_vals.data = (u8 *)xdr->p;
+
+	status = nfsd4_encode_attr_vals(xdr, attrmask, &args);
+	if (status != nfs_ok)
+		return false;
+
+	ne->ne_attrs.attr_vals.len = (u8 *)xdr->p - ne->ne_attrs.attr_vals.data;
+	return true;
+}
+
+/**
+ * nfsd4_encode_notify_event - encode a notify
+ * @xdr: stream to which to encode the fattr4
+ * @nne: nfsd_notify_event to encode
+ * @dp: delegation where the event occurred
+ * @nf: nfsd_file on which event occurred
+ * @notify_mask: pointer to word where notification mask should be set
+ *
+ * Encode @nne into @xdr. The matching bit in @notify_mask is set on
+ * success.
+ *
+ * Return: pointer to the start of the encoded event, or NULL if the
+ * event could not be encoded.
+ */
+u8 *nfsd4_encode_notify_event(struct xdr_stream *xdr, struct nfsd_notify_event *nne,
+			      struct nfs4_delegation *dp, struct nfsd_file *nf,
+			      u32 *notify_mask)
+{
+	u8 *p = NULL;
+
+	*notify_mask = 0;
+
+	if (nne->ne_mask & FS_DELETE) {
+		struct notify_remove4 nr = { };
+
+		if (!nfsd4_setup_notify_entry4(&nr.nrm_old_entry, xdr, nne->ne_dentry, dp,
+					       nf, nne->ne_name, nne->ne_namelen))
+			goto out_err;
+		p = (u8 *)xdr->p;
+		if (!xdrgen_encode_notify_remove4(xdr, &nr))
+			goto out_err;
+		*notify_mask |= BIT(NOTIFY4_REMOVE_ENTRY);
+	} else if (nne->ne_mask & FS_CREATE) {
+		struct notify_add4 na = { };
+		struct notify_remove4 old = { };
+
+		if (!nfsd4_setup_notify_entry4(&na.nad_new_entry, xdr, nne->ne_dentry, dp,
+					       nf, nne->ne_name, nne->ne_namelen))
+			goto out_err;
+
+		/* If a file was overwritten, report it in nad_old_entry */
+		if (nne->ne_target) {
+			if (!nfsd4_setup_notify_entry4(&old.nrm_old_entry, xdr,
+						       NULL, dp, nf,
+						       nne->ne_name, nne->ne_namelen))
+				goto out_err;
+			na.nad_old_entry.count = 1;
+			na.nad_old_entry.element = &old;
+		}
+
+		p = (u8 *)xdr->p;
+		if (!xdrgen_encode_notify_add4(xdr, &na))
+			goto out_err;
+
+		*notify_mask |= BIT(NOTIFY4_ADD_ENTRY);
+	} else if (nne->ne_mask & FS_RENAME) {
+		struct notify_rename4 nr = { };
+		struct notify_remove4 old = { };
+		char *newname = nfsd_notify_event_newname(nne);
+
+		/* Don't send any attributes in the old_entry since they're the same in new */
+		if (!nfsd4_setup_notify_entry4(&nr.nrn_old_entry.nrm_old_entry, xdr,
+					       NULL, dp, nf, nne->ne_name,
+					       nne->ne_namelen))
+			goto out_err;
+
+		if (!nfsd4_setup_notify_entry4(&nr.nrn_new_entry.nad_new_entry, xdr,
+					       nne->ne_dentry, dp, nf, newname,
+					       nne->ne_newnamelen))
+			goto out_err;
+
+		/* If a file was overwritten, report it in nad_old_entry */
+		if (nne->ne_target) {
+			if (!nfsd4_setup_notify_entry4(&old.nrm_old_entry, xdr,
+						       NULL, dp, nf, newname,
+						       nne->ne_newnamelen))
+				goto out_err;
+			nr.nrn_new_entry.nad_old_entry.count = 1;
+			nr.nrn_new_entry.nad_old_entry.element = &old;
+		}
+
+		p = (u8 *)xdr->p;
+		if (!xdrgen_encode_notify_rename4(xdr, &nr))
+			goto out_err;
+		*notify_mask |= BIT(NOTIFY4_RENAME_ENTRY);
+	}
+	return p;
+out_err:
+	pr_warn("nfsd: unable to marshal notify event to xdr stream\n");
+	return NULL;
+}
+
+/**
+ * nfsd4_encode_dir_attr_change
+ * @xdr: stream to which to encode the fattr4
+ * @dp: delegation where the event occurred
+ * @nf: nfsd_file opened on the directory
+ *
+ * Encode a dir attr change event.
+ *
+ * Return: a pointer to the start of the encoded event on success; NULL
+ * if there were no requested attributes to report, in which case the
+ * caller should omit the event; or an ERR_PTR if the event was requested
+ * but could not be marshalled into @xdr, in which case the caller should
+ * recall the delegation.
+ */
+u8 *nfsd4_encode_dir_attr_change(struct xdr_stream *xdr, struct nfs4_delegation *dp,
+				 struct nfsd_file *nf)
+{
+	struct dentry *dentry = nf->nf_file->f_path.dentry;
+	struct notify_attr4 na = { };
+	u8 *p;
+
+	/* RFC 8881 s10.4.3: ne_file must be a zero-length string for dir attrs */
+	if (!nfsd4_setup_notify_entry4(&na.na_changed_entry, xdr,
+				       dentry, dp, nf, "", 0))
+		return ERR_PTR(-ENOBUFS);
+
+	/* No requested attributes to report; omit the event */
+	if (!na.na_changed_entry.ne_attrs.attr_vals.len)
+		return NULL;
+
+	p = (u8 *)xdr->p;
+	if (!xdrgen_encode_notify_attr4(xdr, &na))
+		return ERR_PTR(-ENOBUFS);
+	return p;
+}
+
+static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
+				struct xdr_buf *buf, __be32 *p, int bytes)
+{
+	xdr->scratch.iov_len = 0;
+	memset(buf, 0, sizeof(struct xdr_buf));
+	buf->head[0].iov_base = p;
+	buf->head[0].iov_len = 0;
+	buf->len = 0;
+	xdr->buf = buf;
+	xdr->iov = buf->head;
+	xdr->p = p;
+	xdr->end = (void *)p + bytes;
+	buf->buflen = bytes;
+}
+
+__be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
+			struct svc_fh *fhp, struct svc_export *exp,
+			struct dentry *dentry, u32 *bmval,
+			struct svc_rqst *rqstp, int ignore_crossmnt)
+{
+	struct xdr_buf dummy;
+	struct xdr_stream xdr;
+	__be32 ret;
+
+	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
+	ret = nfsd4_encode_fattr4(rqstp, &xdr, fhp, exp, dentry, bmval,
+				  ignore_crossmnt, NULL);
+	*p = xdr.p;
+	return ret;
+}
+
+/*
+ * The buffer space for this field was reserved during a previous
+ * call to nfsd4_encode_entry4().
+ */
+static void nfsd4_encode_entry4_nfs_cookie4(const struct nfsd4_readdir *readdir,
+					    u64 offset)
+{
+	__be64 cookie = cpu_to_be64(offset);
+	struct xdr_stream *xdr = readdir->xdr;
+
+	if (!readdir->cookie_offset)
+		return;
+	write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset, &cookie,
+			       sizeof(cookie));
+}
+
+static inline int attributes_need_mount(u32 *bmval)
+{
+	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
+		return 1;
+	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
+		return 1;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_entry4_fattr(struct nfsd4_readdir *cd, const char *name,
+			  int namlen)
+{
+	struct svc_export *exp = cd->rd_fhp->fh_export;
+	struct dentry *dentry;
+	__be32 nfserr;
+	int ignore_crossmnt = 0;
+	bool crossed = false;
+
+	dentry = lookup_one_positive_unlocked(&nop_mnt_idmap,
+					      &QSTR_LEN(name, namlen),
+					      cd->rd_fhp->fh_dentry);
+	if (IS_ERR(dentry))
+		return nfserrno(PTR_ERR(dentry));
+
+	exp_get(exp);
+	/*
+	 * In the case of a mountpoint, the client may be asking for
+	 * attributes that are only properties of the underlying filesystem
+	 * as opposed to the cross-mounted file system. In such a case,
+	 * we will not follow the cross mount and will fill the attribtutes
+	 * directly from the mountpoint dentry.
+	 */
+	if (nfsd_mountpoint(dentry, exp)) {
+		int err;
+
+		if (!(exp->ex_flags & NFSEXP_V4ROOT)
+				&& !attributes_need_mount(cd->rd_bmval)) {
+			ignore_crossmnt = 1;
+			goto out_encode;
+		}
+		/*
+		 * Why the heck aren't we just using nfsd_lookup??
+		 * Different "."/".." handling?  Something else?
+		 * At least, add a comment here to explain....
+		 */
+		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
+		if (err) {
+			nfserr = nfserrno(err);
+			goto out_put;
+		}
+		nfserr = check_nfsd_access(exp, cd->rd_rqstp, false);
+		if (nfserr)
+			goto out_put;
+		crossed = true;
+
+	}
+out_encode:
+	/*
+	 * A crossed entry no longer shares a parent with the directory
+	 * being read, so it must neither consume nor populate the
+	 * per-readdir case-folding cache.
+	 */
+	nfserr = nfsd4_encode_fattr4(cd->rd_rqstp, cd->xdr, NULL, exp, dentry,
+				     cd->rd_bmval, ignore_crossmnt,
+				     crossed ? NULL : &cd->rd_case_cache);
+out_put:
+	dput(dentry);
+	exp_put(exp);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_entry4_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
+{
+	__be32 status;
+
+	/* attrmask */
+	status = nfsd4_encode_bitmap4(xdr, FATTR4_WORD0_RDATTR_ERROR, 0, 0);
+	if (status != nfs_ok)
+		return status;
+	/* attr_vals */
+	if (xdr_stream_encode_u32(xdr, XDR_UNIT) != XDR_UNIT)
+		return nfserr_resource;
+	/* rdattr_error */
+	if (xdr_stream_encode_be32(xdr, nfserr) != XDR_UNIT)
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+static int
+nfsd4_encode_entry4(void *ccdv, const char *name, int namlen,
+		    loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = ccdv;
+	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
+	struct xdr_stream *xdr = cd->xdr;
+	int start_offset = xdr->buf->len;
+	int cookie_offset;
+	u32 name_and_cookie;
+	int entry_bytes;
+	__be32 nfserr = nfserr_toosmall;
+
+	/* In nfsv4, "." and ".." never make it onto the wire.. */
+	if (name && name_is_dot_dotdot(name, namlen)) {
+		cd->common.err = nfs_ok;
+		return 0;
+	}
+
+	/* Encode the previous entry's cookie value */
+	nfsd4_encode_entry4_nfs_cookie4(cd, offset);
+
+	if (xdr_stream_encode_item_present(xdr) != XDR_UNIT)
+		goto fail;
+
+	/* Reserve send buffer space for this entry's cookie value. */
+	cookie_offset = xdr->buf->len;
+	if (nfsd4_encode_nfs_cookie4(xdr, OFFSET_MAX) != nfs_ok)
+		goto fail;
+	if (nfsd4_encode_component4(xdr, name, namlen) != nfs_ok)
+		goto fail;
+	nfserr = nfsd4_encode_entry4_fattr(cd, name, namlen);
+	switch (nfserr) {
+	case nfs_ok:
+		break;
+	case nfserr_resource:
+		nfserr = nfserr_toosmall;
+		goto fail;
+	case nfserr_noent:
+		xdr_truncate_encode(xdr, start_offset);
+		goto skip_entry;
+	case nfserr_jukebox:
+		/*
+		 * The pseudoroot should only display dentries that lead to
+		 * exports. If we get EJUKEBOX here, then we can't tell whether
+		 * this entry should be included. Just fail the whole READDIR
+		 * with NFS4ERR_DELAY in that case, and hope that the situation
+		 * will resolve itself by the client's next attempt.
+		 */
+		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
+			goto fail;
+		fallthrough;
+	default:
+		/*
+		 * If the client requested the RDATTR_ERROR attribute,
+		 * we stuff the error code into this attribute
+		 * and continue.  If this attribute was not requested,
+		 * then in accordance with the spec, we fail the
+		 * entire READDIR operation(!)
+		 */
+		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
+			goto fail;
+		if (nfsd4_encode_entry4_rdattr_error(xdr, nfserr)) {
+			nfserr = nfserr_toosmall;
+			goto fail;
+		}
+	}
+	nfserr = nfserr_toosmall;
+	entry_bytes = xdr->buf->len - start_offset;
+	if (entry_bytes > cd->rd_maxcount)
+		goto fail;
+	cd->rd_maxcount -= entry_bytes;
+	/*
+	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
+	 * notes that it could be zero. If it is zero, then the server
+	 * should enforce only the rd_maxcount value.
+	 */
+	if (cd->rd_dircount) {
+		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
+		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
+			goto fail;
+		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
+		if (!cd->rd_dircount)
+			cd->rd_maxcount = 0;
+	}
+
+	cd->cookie_offset = cookie_offset;
+skip_entry:
+	cd->common.err = nfs_ok;
+	return 0;
+fail:
+	xdr_truncate_encode(xdr, start_offset);
+	cd->common.err = nfserr;
+	return -EINVAL;
+}
+
+static __be32
+nfsd4_encode_verifier4(struct xdr_stream *xdr, const nfs4_verifier *verf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+	memcpy(p, verf->data, sizeof(verf->data));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_clientid4(struct xdr_stream *xdr, const clientid_t *clientid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(__be64));
+	if (!p)
+		return nfserr_resource;
+	memcpy(p, clientid, sizeof(*clientid));
+	return nfs_ok;
+}
+
+/* This is a frequently-encoded item; open-coded for speed */
+static __be32
+nfsd4_encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(sid->si_generation);
+	memcpy(p, &sid->si_opaque, sizeof(sid->si_opaque));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_sessionid4(struct xdr_stream *xdr,
+			const struct nfs4_sessionid *sessionid)
+{
+	return nfsd4_encode_opaque_fixed(xdr, sessionid->data,
+					 NFS4_MAX_SESSIONID_LEN);
+}
+
+static __be32
+nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 status;
+
+	/* supported */
+	status = nfsd4_encode_uint32_t(xdr, access->ac_supported);
+	if (status != nfs_ok)
+		return status;
+	/* access */
+	return nfsd4_encode_uint32_t(xdr, access->ac_resp_access);
+}
+
+static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr,
+						union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* bctsr_sessid */
+	nfserr = nfsd4_encode_sessionid4(xdr, &bcts->sessionid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* bctsr_dir */
+	if (xdr_stream_encode_u32(xdr, bcts->dir) != XDR_UNIT)
+		return nfserr_resource;
+	/* bctsr_use_conn_in_rdma_mode */
+	return nfsd4_encode_bool(xdr, false);
+}
+
+static __be32
+nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* open_stateid */
+	return nfsd4_encode_stateid4(xdr, &close->cl_stateid);
+}
+
+
+static __be32
+nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+
+	return nfsd4_encode_verifier4(resp->xdr, &commit->co_verf);
+}
+
+static __be32
+nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* cinfo */
+	nfserr = nfsd4_encode_change_info4(xdr, &create->cr_cinfo);
+	if (nfserr)
+		return nfserr;
+	/* attrset */
+	return nfsd4_encode_bitmap4(xdr, create->cr_bmval[0],
+				    create->cr_bmval[1], create->cr_bmval[2]);
+}
+
+static __be32
+nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	struct svc_fh *fhp = getattr->ga_fhp;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* obj_attributes */
+	return nfsd4_encode_fattr4(resp->rqstp, xdr, fhp, fhp->fh_export,
+				   fhp->fh_dentry, getattr->ga_bmval, 0, NULL);
+}
+
+static __be32
+nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct svc_fh *fhp = u->getfh;
+
+	/* object */
+	return nfsd4_encode_nfs_fh4(xdr, &fhp->fh_handle);
+}
+
+static __be32
+nfsd4_encode_lock_owner4(struct xdr_stream *xdr, const clientid_t *clientid,
+			 const struct xdr_netobj *owner)
+{
+	__be32 status;
+
+	/* clientid */
+	status = nfsd4_encode_clientid4(xdr, clientid);
+	if (status != nfs_ok)
+		return status;
+	/* owner */
+	return nfsd4_encode_opaque(xdr, owner->data, owner->len);
+}
+
+static __be32
+nfsd4_encode_lock4denied(struct xdr_stream *xdr,
+			 const struct nfsd4_lock_denied *ld)
+{
+	__be32 status;
+
+	/* offset */
+	status = nfsd4_encode_offset4(xdr, ld->ld_start);
+	if (status != nfs_ok)
+		return status;
+	/* length */
+	status = nfsd4_encode_length4(xdr, ld->ld_length);
+	if (status != nfs_ok)
+		return status;
+	/* locktype */
+	if (xdr_stream_encode_u32(xdr, ld->ld_type) != XDR_UNIT)
+		return nfserr_resource;
+	/* owner */
+	return nfsd4_encode_lock_owner4(xdr, &ld->ld_clientid,
+					&ld->ld_owner);
+}
+
+static __be32
+nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 status;
+
+	switch (nfserr) {
+	case nfs_ok:
+		/* resok4 */
+		status = nfsd4_encode_stateid4(xdr, &lock->lk_resp_stateid);
+		break;
+	case nfserr_denied:
+		/* denied */
+		status = nfsd4_encode_lock4denied(xdr, &lock->lk_denied);
+		break;
+	default:
+		return nfserr;
+	}
+	return status != nfs_ok ? status : nfserr;
+}
+
+static __be32
+nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 status;
+
+	if (nfserr == nfserr_denied) {
+		/* denied */
+		status = nfsd4_encode_lock4denied(xdr, &lockt->lt_denied);
+		if (status != nfs_ok)
+			return status;
+	}
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* lock_stateid */
+	return nfsd4_encode_stateid4(xdr, &locku->lu_stateid);
+}
+
+
+static __be32
+nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &link->li_cinfo);
+}
+
+/*
+ * This implementation does not yet support returning an ACE in an
+ * OPEN that offers a delegation.
+ */
+static __be32
+nfsd4_encode_open_nfsace4(struct xdr_stream *xdr)
+{
+	__be32 status;
+
+	/* type */
+	status = nfsd4_encode_acetype4(xdr, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* flag */
+	status = nfsd4_encode_aceflag4(xdr, 0);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* access mask */
+	status = nfsd4_encode_acemask4(xdr, 0);
+	if (status != nfs_ok)
+		return nfserr_resource;
+	/* who - empty for now */
+	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_open_read_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	/* stateid */
+	status = nfsd4_encode_stateid4(xdr, &open->op_delegate_stateid);
+	if (status != nfs_ok)
+		return status;
+	/* recall */
+	status = nfsd4_encode_bool(xdr, open->op_recall);
+	if (status != nfs_ok)
+		return status;
+	/* permissions */
+	return nfsd4_encode_open_nfsace4(xdr);
+}
+
+static __be32
+nfsd4_encode_nfs_space_limit4(struct xdr_stream *xdr, u64 filesize)
+{
+	/* limitby */
+	if (xdr_stream_encode_u32(xdr, NFS4_LIMIT_SIZE) != XDR_UNIT)
+		return nfserr_resource;
+	/* filesize */
+	return nfsd4_encode_uint64_t(xdr, filesize);
+}
+
+static __be32
+nfsd4_encode_open_write_delegation4(struct xdr_stream *xdr,
+				    struct nfsd4_open *open)
+{
+	__be32 status;
+
+	/* stateid */
+	status = nfsd4_encode_stateid4(xdr, &open->op_delegate_stateid);
+	if (status != nfs_ok)
+		return status;
+	/* recall */
+	status = nfsd4_encode_bool(xdr, open->op_recall);
+	if (status != nfs_ok)
+		return status;
+	/* space_limit */
+	status = nfsd4_encode_nfs_space_limit4(xdr, 0);
+	if (status != nfs_ok)
+		return status;
+	return nfsd4_encode_open_nfsace4(xdr);
+}
+
+static __be32
+nfsd4_encode_open_none_delegation4(struct xdr_stream *xdr,
+				   struct nfsd4_open *open)
+{
+	__be32 status = nfs_ok;
+
+	/* ond_why */
+	if (xdr_stream_encode_u32(xdr, open->op_why_no_deleg) != XDR_UNIT)
+		return nfserr_resource;
+	switch (open->op_why_no_deleg) {
+	case WND4_CONTENTION:
+		/* ond_server_will_push_deleg */
+		status = nfsd4_encode_bool(xdr, false);
+		break;
+	case WND4_RESOURCE:
+		/* ond_server_will_signal_avail */
+		status = nfsd4_encode_bool(xdr, false);
+	}
+	return status;
+}
+
+static __be32
+nfsd4_encode_open_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	/* delegation_type */
+	if (xdr_stream_encode_u32(xdr, open->op_delegate_type) != XDR_UNIT)
+		return nfserr_resource;
+	switch (open->op_delegate_type) {
+	case OPEN_DELEGATE_NONE:
+		status = nfs_ok;
+		break;
+	case OPEN_DELEGATE_READ:
+	case OPEN_DELEGATE_READ_ATTRS_DELEG:
+		/* read */
+		status = nfsd4_encode_open_read_delegation4(xdr, open);
+		break;
+	case OPEN_DELEGATE_WRITE:
+	case OPEN_DELEGATE_WRITE_ATTRS_DELEG:
+		/* write */
+		status = nfsd4_encode_open_write_delegation4(xdr, open);
+		break;
+	case OPEN_DELEGATE_NONE_EXT:
+		/* od_whynone */
+		status = nfsd4_encode_open_none_delegation4(xdr, open);
+		break;
+	default:
+		status = nfserr_serverfault;
+	}
+
+	return status;
+}
+
+static __be32
+nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* stateid */
+	nfserr = nfsd4_encode_stateid4(xdr, &open->op_stateid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* cinfo */
+	nfserr = nfsd4_encode_change_info4(xdr, &open->op_cinfo);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* rflags */
+	nfserr = nfsd4_encode_uint32_t(xdr, open->op_rflags);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* attrset */
+	nfserr = nfsd4_encode_bitmap4(xdr, open->op_bmval[0],
+				      open->op_bmval[1], open->op_bmval[2]);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* delegation */
+	return nfsd4_encode_open_delegation4(xdr, open);
+}
+
+static __be32
+nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *oc = &u->open_confirm;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* open_stateid */
+	return nfsd4_encode_stateid4(xdr, &oc->oc_resp_stateid);
+}
+
+static __be32
+nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *od = &u->open_downgrade;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* open_stateid */
+	return nfsd4_encode_stateid4(xdr, &od->od_stateid);
+}
+
+/*
+ * The operation of this function assumes that this is the only
+ * READ operation in the COMPOUND. If there are multiple READs,
+ * we use nfsd4_encode_readv().
+ */
+static __be32 nfsd4_encode_splice_read(
+				struct nfsd4_compoundres *resp,
+				struct nfsd4_read *read,
+				struct file *file, unsigned long maxcount)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct xdr_buf *buf = xdr->buf;
+	int status, space_left;
+	__be32 nfserr;
+
+	/*
+	 * Splice read doesn't work if encoding has already wandered
+	 * into the XDR buf's page array.
+	 */
+	if (unlikely(xdr->buf->page_len)) {
+		WARN_ON_ONCE(1);
+		return nfserr_serverfault;
+	}
+
+	/*
+	 * Make sure there is room at the end of buf->head for
+	 * svcxdr_encode_opaque_pages() to create a tail buffer
+	 * to XDR-pad the payload.
+	 */
+	if (xdr->iov != xdr->buf->head || xdr->end - xdr->p < 1)
+		return nfserr_resource;
+
+	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
+				  file, read->rd_offset, &maxcount,
+				  &read->rd_eof);
+	read->rd_length = maxcount;
+	if (nfserr)
+		goto out_err;
+	svcxdr_encode_opaque_pages(read->rd_rqstp, xdr, buf->pages,
+				   buf->page_base, maxcount);
+	status = svc_encode_result_payload(read->rd_rqstp,
+					   buf->head[0].iov_len, maxcount);
+	if (status) {
+		nfserr = nfserrno(status);
+		goto out_err;
+	}
+
+	/*
+	 * Prepare to encode subsequent operations.
+	 *
+	 * xdr_truncate_encode() is not safe to use after a successful
+	 * splice read has been done, so the following stream
+	 * manipulations are open-coded.
+	 */
+	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
+				buf->buflen - buf->len);
+	buf->buflen = buf->len + space_left;
+	xdr->end = (__be32 *)((void *)xdr->end + space_left);
+
+	return nfs_ok;
+
+out_err:
+	/*
+	 * nfsd_splice_actor may have already messed with the
+	 * page length; reset it so as not to confuse
+	 * xdr_truncate_encode in our caller.
+	 */
+	buf->page_len = 0;
+	return nfserr;
+}
+
+static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
+				 struct nfsd4_read *read,
+				 unsigned long maxcount)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	unsigned int base = xdr->buf->page_len & ~PAGE_MASK;
+	unsigned int starting_len = xdr->buf->len;
+	__be32 zero = xdr_zero;
+	__be32 nfserr;
+
+	nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, read->rd_nf,
+				read->rd_offset, &maxcount, base,
+				&read->rd_eof);
+	read->rd_length = maxcount;
+	if (nfserr)
+		return nfserr;
+
+	/*
+	 * svcxdr_encode_opaque_pages() is not used here because
+	 * we don't want to encode subsequent results in this
+	 * COMPOUND into the xdr->buf's tail, but rather those
+	 * results should follow the NFS READ payload in the
+	 * buf's pages.
+	 */
+	if (xdr_reserve_space_vec(xdr, maxcount) < 0)
+		return nfserr_resource;
+
+	/*
+	 * Mark the buffer location of the NFS READ payload so that
+	 * direct placement-capable transports send only the
+	 * payload bytes out-of-band.
+	 */
+	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
+		return nfserr_io;
+
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
+			       xdr_pad_size(maxcount));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
+	struct nfsd4_read *read = &u->read;
+	struct xdr_stream *xdr = resp->xdr;
+	bool splice_ok = argp->splice_ok;
+	unsigned int eof_offset;
+	unsigned long maxcount;
+	__be32 wire_data[2];
+	struct file *file;
+
+	if (nfserr)
+		return nfserr;
+
+	eof_offset = xdr->buf->len;
+	file = read->rd_nf->nf_file;
+
+	/* Reserve space for the eof flag and byte count */
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT * 2))) {
+		WARN_ON_ONCE(splice_ok);
+		return nfserr_resource;
+	}
+	xdr_commit_encode(xdr);
+
+	maxcount = min_t(unsigned long, read->rd_length,
+			 (xdr->buf->buflen - xdr->buf->len));
+
+	if (file->f_op->splice_read && splice_ok)
+		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+	else
+		nfserr = nfsd4_encode_readv(resp, read, maxcount);
+	if (nfserr) {
+		xdr_truncate_encode(xdr, eof_offset);
+		return nfserr;
+	}
+
+	wire_data[0] = read->rd_eof ? xdr_one : xdr_zero;
+	wire_data[1] = cpu_to_be32(read->rd_length);
+	write_bytes_to_xdr_buf(xdr->buf, eof_offset, &wire_data, XDR_UNIT * 2);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_readlink *readlink = &u->readlink;
+	__be32 *p, wire_count, zero = xdr_zero;
+	struct xdr_stream *xdr = resp->xdr;
+	unsigned int length_offset;
+	int maxcount, status;
+
+	/* linktext4.count */
+	length_offset = xdr->buf->len;
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT)))
+		return nfserr_resource;
+
+	/* linktext4.data */
+	maxcount = PAGE_SIZE;
+	p = xdr_reserve_space(xdr, maxcount);
+	if (!p)
+		return nfserr_resource;
+	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
+						(char *)p, &maxcount);
+	if (nfserr == nfserr_isdir)
+		nfserr = nfserr_inval;
+	if (nfserr)
+		goto out_err;
+	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
+					   maxcount);
+	if (status) {
+		nfserr = nfserrno(status);
+		goto out_err;
+	}
+
+	wire_count = cpu_to_be32(maxcount);
+	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, XDR_UNIT);
+	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
+	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
+			       xdr_pad_size(maxcount));
+	return nfs_ok;
+
+out_err:
+	xdr_truncate_encode(xdr, length_offset);
+	return nfserr;
+}
+
+static __be32 nfsd4_encode_dirlist4(struct xdr_stream *xdr,
+				    struct nfsd4_readdir *readdir,
+				    u32 max_payload)
+{
+	int bytes_left, maxcount, starting_len = xdr->buf->len;
+	loff_t offset;
+	__be32 status;
+
+	/*
+	 * Number of bytes left for directory entries allowing for the
+	 * final 8 bytes of the readdir and a following failed op.
+	 */
+	bytes_left = xdr->buf->buflen - xdr->buf->len -
+		COMPOUND_ERR_SLACK_SPACE - XDR_UNIT * 2;
+	if (bytes_left < 0)
+		return nfserr_resource;
+	maxcount = min_t(u32, readdir->rd_maxcount, max_payload);
+
+	/*
+	 * The RFC defines rd_maxcount as the size of the
+	 * READDIR4resok structure, which includes the verifier
+	 * and the 8 bytes encoded at the end of this function.
+	 */
+	if (maxcount < XDR_UNIT * 4)
+		return nfserr_toosmall;
+	maxcount = min_t(int, maxcount - XDR_UNIT * 4, bytes_left);
+
+	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0 */
+	if (!readdir->rd_dircount)
+		readdir->rd_dircount = max_payload;
+
+	/* *entries */
+	readdir->xdr = xdr;
+	readdir->rd_maxcount = maxcount;
+	readdir->common.err = 0;
+	readdir->cookie_offset = 0;
+	readdir->rd_case_cache.dir = readdir->rd_fhp->fh_dentry;
+	readdir->rd_case_cache.valid = false;
+	offset = readdir->rd_cookie;
+	status = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp, &offset,
+			      &readdir->common, nfsd4_encode_entry4);
+	if (status)
+		return status;
+	if (readdir->common.err == nfserr_toosmall &&
+	    xdr->buf->len == starting_len) {
+		/* No entries were encoded. Which limit did we hit? */
+		if (maxcount - XDR_UNIT * 4 < bytes_left)
+			/* It was the fault of rd_maxcount */
+			return nfserr_toosmall;
+		/* We ran out of buffer space */
+		return nfserr_resource;
+	}
+	/* Encode the final entry's cookie value */
+	nfsd4_encode_entry4_nfs_cookie4(readdir, offset);
+	/* No entries follow */
+	if (xdr_stream_encode_item_absent(xdr) != XDR_UNIT)
+		return nfserr_resource;
+
+	/* eof */
+	return nfsd4_encode_bool(xdr, readdir->common.err == nfserr_eof);
+}
+
+static __be32
+nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	struct xdr_stream *xdr = resp->xdr;
+	int starting_len = xdr->buf->len;
+
+	/* cookieverf */
+	nfserr = nfsd4_encode_verifier4(xdr, &readdir->rd_verf);
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	/* reply */
+	nfserr = nfsd4_encode_dirlist4(xdr, readdir, svc_max_payload(resp->rqstp));
+	if (nfserr != nfs_ok)
+		xdr_truncate_encode(xdr, starting_len);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &remove->rm_cinfo);
+}
+
+static __be32
+nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	struct xdr_stream *xdr = resp->xdr;
+
+	nfserr = nfsd4_encode_change_info4(xdr, &rename->rn_sinfo);
+	if (nfserr)
+		return nfserr;
+	return nfsd4_encode_change_info4(xdr, &rename->rn_tinfo);
+}
+
+static __be32
+nfsd4_encode_rpcsec_gss_info(struct xdr_stream *xdr,
+			     struct rpcsec_gss_info *info)
+{
+	__be32 status;
+
+	/* oid */
+	if (xdr_stream_encode_opaque(xdr, info->oid.data, info->oid.len) < 0)
+		return nfserr_resource;
+	/* qop */
+	status = nfsd4_encode_qop4(xdr, info->qop);
+	if (status != nfs_ok)
+		return status;
+	/* service */
+	if (xdr_stream_encode_u32(xdr, info->service) != XDR_UNIT)
+		return nfserr_resource;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_secinfo4(struct xdr_stream *xdr, rpc_authflavor_t pf,
+		      u32 *supported)
+{
+	struct rpcsec_gss_info info;
+	__be32 status;
+
+	if (rpcauth_get_gssinfo(pf, &info) == 0) {
+		(*supported)++;
+
+		/* flavor */
+		status = nfsd4_encode_uint32_t(xdr, RPC_AUTH_GSS);
+		if (status != nfs_ok)
+			return status;
+		/* flavor_info */
+		status = nfsd4_encode_rpcsec_gss_info(xdr, &info);
+		if (status != nfs_ok)
+			return status;
+	} else if (pf < RPC_AUTH_MAXFLAVOR) {
+		(*supported)++;
+
+		/* flavor */
+		status = nfsd4_encode_uint32_t(xdr, pf);
+		if (status != nfs_ok)
+			return status;
+	}
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_SECINFO4resok(struct xdr_stream *xdr, struct svc_export *exp)
+{
+	u32 i, nflavs, supported;
+	struct exp_flavor_info *flavs;
+	struct exp_flavor_info def_flavs[2];
+	unsigned int count_offset;
+	__be32 status, wire_count;
+
+	if (exp->ex_nflavors) {
+		flavs = exp->ex_flavors;
+		nflavs = exp->ex_nflavors;
+	} else { /* Handling of some defaults in absence of real secinfo: */
+		flavs = def_flavs;
+		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
+			nflavs = 2;
+			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
+			flavs[1].pseudoflavor = RPC_AUTH_NULL;
+		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= svcauth_gss_flavor(exp->ex_client);
+		} else {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= exp->ex_client->flavour->flavour;
+		}
+	}
+
+	count_offset = xdr->buf->len;
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT)))
+		return nfserr_resource;
+
+	for (i = 0, supported = 0; i < nflavs; i++) {
+		status = nfsd4_encode_secinfo4(xdr, flavs[i].pseudoflavor,
+					       &supported);
+		if (status != nfs_ok)
+			return status;
+	}
+
+	wire_count = cpu_to_be32(supported);
+	write_bytes_to_xdr_buf(xdr->buf, count_offset, &wire_count,
+			       XDR_UNIT);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_SECINFO4resok(xdr, secinfo->si_exp);
+}
+
+static __be32
+nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo_no_name *secinfo = &u->secinfo_no_name;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_SECINFO4resok(xdr, secinfo->sin_exp);
+}
+
+static __be32
+nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	__be32 status;
+
+	switch (nfserr) {
+	case nfs_ok:
+		/* attrsset */
+		status = nfsd4_encode_bitmap4(resp->xdr, setattr->sa_bmval[0],
+					      setattr->sa_bmval[1],
+					      setattr->sa_bmval[2]);
+		break;
+	default:
+		/* attrsset */
+		status = nfsd4_encode_bitmap4(resp->xdr, 0, 0, 0);
+	}
+	return status != nfs_ok ? status : nfserr;
+}
+
+static __be32
+nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *scd = &u->setclientid;
+	struct xdr_stream *xdr = resp->xdr;
+
+	if (!nfserr) {
+		nfserr = nfsd4_encode_clientid4(xdr, &scd->se_clientid);
+		if (nfserr != nfs_ok)
+			goto out;
+		nfserr = nfsd4_encode_verifier4(xdr, &scd->se_confirm);
+	} else if (nfserr == nfserr_clid_inuse) {
+		/* empty network id */
+		if (xdr_stream_encode_u32(xdr, 0) < 0) {
+			nfserr = nfserr_resource;
+			goto out;
+		}
+		/* empty universal address */
+		if (xdr_stream_encode_u32(xdr, 0) < 0) {
+			nfserr = nfserr_resource;
+			goto out;
+		}
+	}
+out:
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* count */
+	nfserr = nfsd4_encode_count4(xdr, write->wr_bytes_written);
+	if (nfserr)
+		return nfserr;
+	/* committed */
+	if (xdr_stream_encode_u32(xdr, write->wr_how_written) != XDR_UNIT)
+		return nfserr_resource;
+	/* writeverf */
+	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
+}
+
+static __be32
+nfsd4_encode_state_protect_ops4(struct xdr_stream *xdr,
+				struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	/* spo_must_enforce */
+	status = nfsd4_encode_bitmap4(xdr, exid->spo_must_enforce[0],
+				      exid->spo_must_enforce[1],
+				      exid->spo_must_enforce[2]);
+	if (status != nfs_ok)
+		return status;
+	/* spo_must_allow */
+	return nfsd4_encode_bitmap4(xdr, exid->spo_must_allow[0],
+				    exid->spo_must_allow[1],
+				    exid->spo_must_allow[2]);
+}
+
+static __be32
+nfsd4_encode_state_protect4_r(struct xdr_stream *xdr, struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	if (xdr_stream_encode_u32(xdr, exid->spa_how) != XDR_UNIT)
+		return nfserr_resource;
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		status = nfs_ok;
+		break;
+	case SP4_MACH_CRED:
+		/* spr_mach_ops */
+		status = nfsd4_encode_state_protect_ops4(xdr, exid);
+		break;
+	default:
+		status = nfserr_serverfault;
+	}
+	return status;
+}
+
+static __be32
+nfsd4_encode_server_owner4(struct xdr_stream *xdr, struct svc_rqst *rqstp)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	__be32 status;
+
+	/* so_minor_id */
+	status = nfsd4_encode_uint64_t(xdr, 0);
+	if (status != nfs_ok)
+		return status;
+	/* so_major_id */
+	return nfsd4_encode_opaque(xdr, nn->nfsd_name, strlen(nn->nfsd_name));
+}
+
+static __be32
+nfsd4_encode_nfs_impl_id4(struct xdr_stream *xdr, struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	/* nii_domain */
+	status = nfsd4_encode_opaque(xdr, exid->nii_domain.data,
+				     exid->nii_domain.len);
+	if (status != nfs_ok)
+		return status;
+	/* nii_name */
+	status = nfsd4_encode_opaque(xdr, exid->nii_name.data,
+				     exid->nii_name.len);
+	if (status != nfs_ok)
+		return status;
+	/* nii_time */
+	return nfsd4_encode_nfstime4(xdr, &exid->nii_time);
+}
+
+static __be32
+nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* eir_clientid */
+	nfserr = nfsd4_encode_clientid4(xdr, &exid->clientid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_sequenceid */
+	nfserr = nfsd4_encode_sequenceid4(xdr, exid->seqid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_flags */
+	nfserr = nfsd4_encode_uint32_t(xdr, exid->flags);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_state_protect */
+	nfserr = nfsd4_encode_state_protect4_r(xdr, exid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_server_owner */
+	nfserr = nfsd4_encode_server_owner4(xdr, resp->rqstp);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_server_scope */
+	nfserr = nfsd4_encode_opaque(xdr, nn->nfsd_name,
+				     strlen(nn->nfsd_name));
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* eir_server_impl_id<1> */
+	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
+		return nfserr_resource;
+	nfserr = nfsd4_encode_nfs_impl_id4(xdr, exid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_channel_attrs4(struct xdr_stream *xdr,
+			    const struct nfsd4_channel_attrs *attrs)
+{
+	__be32 status;
+
+	/* ca_headerpadsize */
+	status = nfsd4_encode_count4(xdr, 0);
+	if (status != nfs_ok)
+		return status;
+	/* ca_maxrequestsize */
+	status = nfsd4_encode_count4(xdr, attrs->maxreq_sz);
+	if (status != nfs_ok)
+		return status;
+	/* ca_maxresponsesize */
+	status = nfsd4_encode_count4(xdr, attrs->maxresp_sz);
+	if (status != nfs_ok)
+		return status;
+	/* ca_maxresponsesize_cached */
+	status = nfsd4_encode_count4(xdr, attrs->maxresp_cached);
+	if (status != nfs_ok)
+		return status;
+	/* ca_maxoperations */
+	status = nfsd4_encode_count4(xdr, attrs->maxops);
+	if (status != nfs_ok)
+		return status;
+	/* ca_maxrequests */
+	status = nfsd4_encode_count4(xdr, attrs->maxreqs);
+	if (status != nfs_ok)
+		return status;
+	/* ca_rdma_ird<1> */
+	if (xdr_stream_encode_u32(xdr, attrs->nr_rdma_attrs) != XDR_UNIT)
+		return nfserr_resource;
+	if (attrs->nr_rdma_attrs)
+		return nfsd4_encode_uint32_t(xdr, attrs->rdma_attrs);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *sess = &u->create_session;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* csr_sessionid */
+	nfserr = nfsd4_encode_sessionid4(xdr, &sess->sessionid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* csr_sequence */
+	nfserr = nfsd4_encode_sequenceid4(xdr, sess->seqid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* csr_flags */
+	nfserr = nfsd4_encode_uint32_t(xdr, sess->flags);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* csr_fore_chan_attrs */
+	nfserr = nfsd4_encode_channel_attrs4(xdr, &sess->fore_channel);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* csr_back_chan_attrs */
+	return nfsd4_encode_channel_attrs4(xdr, &sess->back_channel);
+}
+
+static __be32
+nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* sr_sessionid */
+	nfserr = nfsd4_encode_sessionid4(xdr, &seq->sessionid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* sr_sequenceid */
+	nfserr = nfsd4_encode_sequenceid4(xdr, seq->seqid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* sr_slotid */
+	nfserr = nfsd4_encode_slotid4(xdr, seq->slotid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* Note slotid's are numbered from zero: */
+	/* sr_highest_slotid */
+	nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots_response - 1);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* sr_target_highest_slotid */
+	nfserr = nfsd4_encode_slotid4(xdr, seq->target_maxslots - 1);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* sr_status_flags */
+	nfserr = nfsd4_encode_uint32_t(xdr, seq->status_flags);
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct nfsd4_test_stateid_id *stateid, *next;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* tsr_status_codes<> */
+	if (xdr_stream_encode_u32(xdr, test_stateid->ts_num_ids) != XDR_UNIT)
+		return nfserr_resource;
+	list_for_each_entry_safe(stateid, next,
+				 &test_stateid->ts_stateid_list, ts_id_list) {
+		if (xdr_stream_encode_be32(xdr, stateid->ts_id_status) != XDR_UNIT)
+			return nfserr_resource;
+	}
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_get_dir_delegation(struct nfsd4_compoundres *resp, __be32 nfserr,
+				union nfsd4_op_u *u)
+{
+	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 status = nfserr_resource;
+
+	switch(gdd->gddrnf_status) {
+	case GDD4_OK:
+		if (xdr_stream_encode_u32(xdr, GDD4_OK) != XDR_UNIT)
+			break;
+		status = nfsd4_encode_verifier4(xdr, &gdd->gddr_cookieverf);
+		if (status)
+			break;
+		status = nfsd4_encode_stateid4(xdr, &gdd->gddr_stateid);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_notification[0], 0, 0);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_child_attributes[0],
+						   gdd->gddr_child_attributes[1],
+						   gdd->gddr_child_attributes[2]);
+		if (status)
+			break;
+		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_dir_attributes[0],
+						   gdd->gddr_dir_attributes[1],
+						   gdd->gddr_dir_attributes[2]);
+		break;
+	default:
+		pr_warn("nfsd: bad gddrnf_status (%u)\n", gdd->gddrnf_status);
+		gdd->gddrnf_will_signal_deleg_avail = 0;
+		fallthrough;
+	case GDD4_UNAVAIL:
+		if (xdr_stream_encode_u32(xdr, GDD4_UNAVAIL) != XDR_UNIT)
+			break;
+		status = nfsd4_encode_bool(xdr, gdd->gddrnf_will_signal_deleg_avail);
+		break;
+	}
+	return status;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_encode_device_addr4(struct xdr_stream *xdr,
+			  const struct nfsd4_getdeviceinfo *gdev)
+{
+	u32 needed_len, starting_len = xdr->buf->len;
+	const struct nfsd4_layout_ops *ops;
+	__be32 status;
+
+	/* da_layout_type */
+	if (xdr_stream_encode_u32(xdr, gdev->gd_layout_type) != XDR_UNIT)
+		return nfserr_resource;
+	/* da_addr_body */
+	ops = nfsd4_layout_ops[gdev->gd_layout_type];
+	status = ops->encode_getdeviceinfo(xdr, gdev);
+	if (status != nfs_ok) {
+		/*
+		 * Don't burden the layout drivers with enforcing
+		 * gd_maxcount. Just tell the client to come back
+		 * with a bigger buffer if it's not enough.
+		 */
+		if (xdr->buf->len + XDR_UNIT > gdev->gd_maxcount)
+			goto toosmall;
+		return status;
+	}
+
+	return nfs_ok;
+
+toosmall:
+	needed_len = xdr->buf->len + XDR_UNIT;	/* notifications */
+	xdr_truncate_encode(xdr, starting_len);
+
+	status = nfsd4_encode_count4(xdr, needed_len);
+	if (status != nfs_ok)
+		return status;
+	return nfserr_toosmall;
+}
+
+static __be32
+nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* gdir_device_addr */
+	nfserr = nfsd4_encode_device_addr4(xdr, gdev);
+	if (nfserr)
+		return nfserr;
+	/* gdir_notification */
+	return nfsd4_encode_bitmap4(xdr, gdev->gd_notify_types, 0, 0);
+}
+
+static __be32
+nfsd4_encode_layout4(struct xdr_stream *xdr, const struct nfsd4_layoutget *lgp)
+{
+	const struct nfsd4_layout_ops *ops = nfsd4_layout_ops[lgp->lg_layout_type];
+	__be32 status;
+
+	/* lo_offset */
+	status = nfsd4_encode_offset4(xdr, lgp->lg_seg.offset);
+	if (status != nfs_ok)
+		return status;
+	/* lo_length */
+	status = nfsd4_encode_length4(xdr, lgp->lg_seg.length);
+	if (status != nfs_ok)
+		return status;
+	/* lo_iomode */
+	if (xdr_stream_encode_u32(xdr, lgp->lg_seg.iomode) != XDR_UNIT)
+		return nfserr_resource;
+	/* lo_content */
+	if (xdr_stream_encode_u32(xdr, lgp->lg_layout_type) != XDR_UNIT)
+		return nfserr_resource;
+	return ops->encode_layoutget(xdr, lgp);
+}
+
+static __be32
+nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* logr_return_on_close */
+	nfserr = nfsd4_encode_bool(xdr, true);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* logr_stateid */
+	nfserr = nfsd4_encode_stateid4(xdr, &lgp->lg_sid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* logr_layout<> */
+	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
+		return nfserr_resource;
+	return nfsd4_encode_layout4(xdr, lgp);
+}
+
+static __be32
+nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* ns_sizechanged */
+	nfserr = nfsd4_encode_bool(xdr, lcp->lc_size_chg);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	if (lcp->lc_size_chg)
+		/* ns_size */
+		return nfsd4_encode_length4(xdr, lcp->lc_newsize);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* lrs_present */
+	nfserr = nfsd4_encode_bool(xdr, lrp->lrs_present);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	if (lrp->lrs_present)
+		/* lrs_stateid */
+		return nfsd4_encode_stateid4(xdr, &lrp->lr_sid);
+	return nfs_ok;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_encode_write_response4(struct xdr_stream *xdr,
+			     const struct nfsd4_copy *copy)
+{
+	const struct nfsd42_write_res *write = &copy->cp_res;
+	u32 count = nfsd4_copy_is_sync(copy) ? 0 : 1;
+	__be32 status;
+
+	/* wr_callback_id<1> */
+	if (xdr_stream_encode_u32(xdr, count) != XDR_UNIT)
+		return nfserr_resource;
+	if (count) {
+		status = nfsd4_encode_stateid4(xdr, &write->cb_stateid);
+		if (status != nfs_ok)
+			return status;
+	}
+
+	/* wr_count */
+	status = nfsd4_encode_length4(xdr, write->wr_bytes_written);
+	if (status != nfs_ok)
+		return status;
+	/* wr_committed */
+	if (xdr_stream_encode_u32(xdr, write->wr_stable_how) != XDR_UNIT)
+		return nfserr_resource;
+	/* wr_writeverf */
+	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
+}
+
+static __be32 nfsd4_encode_copy_requirements4(struct xdr_stream *xdr,
+					      const struct nfsd4_copy *copy)
+{
+	__be32 status;
+
+	/* cr_consecutive */
+	status = nfsd4_encode_bool(xdr, true);
+	if (status != nfs_ok)
+		return status;
+	/* cr_synchronous */
+	return nfsd4_encode_bool(xdr, nfsd4_copy_is_sync(copy));
+}
+
+static __be32
+nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_copy *copy = &u->copy;
+
+	nfserr = nfsd4_encode_write_response4(resp->xdr, copy);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	return nfsd4_encode_copy_requirements4(resp->xdr, copy);
+}
+
+static __be32
+nfsd4_encode_netloc4(struct xdr_stream *xdr, const struct nl4_server *ns)
+{
+	__be32 status;
+
+	if (xdr_stream_encode_u32(xdr, ns->nl4_type) != XDR_UNIT)
+		return nfserr_resource;
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		/* nl_addr */
+		status = nfsd4_encode_netaddr4(xdr, &ns->u.nl4_addr);
+		break;
+	default:
+		status = nfserr_serverfault;
+	}
+	return status;
+}
+
+static __be32
+nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* cnr_lease_time */
+	nfserr = nfsd4_encode_nfstime4(xdr, &cn->cpn_lease_time);
+	if (nfserr)
+		return nfserr;
+	/* cnr_stateid */
+	nfserr = nfsd4_encode_stateid4(xdr, &cn->cpn_cnr_stateid);
+	if (nfserr)
+		return nfserr;
+	/* cnr_source_server<> */
+	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
+		return nfserr_resource;
+	return nfsd4_encode_netloc4(xdr, cn->cpn_src);
+}
+
+static __be32
+nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* osr_count */
+	nfserr = nfsd4_encode_length4(xdr, os->count);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* osr_complete<1> */
+	if (os->completed) {
+		if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
+			return nfserr_resource;
+		if (xdr_stream_encode_be32(xdr, os->status) != XDR_UNIT)
+			return nfserr_resource;
+	} else if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
+			    struct nfsd4_read *read)
+{
+	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
+	struct file *file = read->rd_nf->nf_file;
+	struct xdr_stream *xdr = resp->xdr;
+	bool splice_ok = argp->splice_ok;
+	unsigned int offset_offset;
+	__be32 nfserr, wire_count;
+	unsigned long maxcount;
+	__be64 wire_offset;
+
+	if (xdr_stream_encode_u32(xdr, NFS4_CONTENT_DATA) != XDR_UNIT)
+		return nfserr_io;
+
+	offset_offset = xdr->buf->len;
+
+	/* Reserve space for the byte offset and count */
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT * 3)))
+		return nfserr_io;
+	xdr_commit_encode(xdr);
+
+	maxcount = min_t(unsigned long, read->rd_length,
+			 (xdr->buf->buflen - xdr->buf->len));
+
+	if (file->f_op->splice_read && splice_ok)
+		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+	else
+		nfserr = nfsd4_encode_readv(resp, read, maxcount);
+	if (nfserr)
+		return nfserr;
+
+	wire_offset = cpu_to_be64(read->rd_offset);
+	write_bytes_to_xdr_buf(xdr->buf, offset_offset, &wire_offset,
+			       XDR_UNIT * 2);
+	wire_count = cpu_to_be32(read->rd_length);
+	write_bytes_to_xdr_buf(xdr->buf, offset_offset + XDR_UNIT * 2,
+			       &wire_count, XDR_UNIT);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
+		       union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	struct file *file = read->rd_nf->nf_file;
+	struct xdr_stream *xdr = resp->xdr;
+	unsigned int eof_offset;
+	__be32 wire_data[2];
+	u32 segments = 0;
+
+	if (nfserr)
+		return nfserr;
+
+	eof_offset = xdr->buf->len;
+
+	/* Reserve space for the eof flag and segment count */
+	if (unlikely(!xdr_reserve_space(xdr, XDR_UNIT * 2)))
+		return nfserr_io;
+	xdr_commit_encode(xdr);
+
+	read->rd_eof = read->rd_offset >= i_size_read(file_inode(file));
+	if (read->rd_eof)
+		goto out;
+
+	nfserr = nfsd4_encode_read_plus_data(resp, read);
+	if (nfserr) {
+		xdr_truncate_encode(xdr, eof_offset);
+		return nfserr;
+	}
+
+	segments++;
+
+out:
+	wire_data[0] = read->rd_eof ? xdr_one : xdr_zero;
+	wire_data[1] = cpu_to_be32(segments);
+	write_bytes_to_xdr_buf(xdr->buf, eof_offset, &wire_data, XDR_UNIT * 2);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	struct xdr_stream *xdr = resp->xdr;
+
+	/* sr_eof */
+	nfserr = nfsd4_encode_bool(xdr, seek->seek_eof);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* sr_offset */
+	return nfsd4_encode_offset4(xdr, seek->seek_pos);
+}
+
+static __be32
+nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *p)
+{
+	return nfserr;
+}
+
+/*
+ * Encode kmalloc-ed buffer in to XDR stream.
+ */
+static __be32
+nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
+{
+	u32 cplen;
+	__be32 *p;
+
+	cplen = min_t(unsigned long, buflen,
+		      ((void *)xdr->end - (void *)xdr->p));
+	p = xdr_reserve_space(xdr, cplen);
+	if (!p)
+		return nfserr_resource;
+
+	memcpy(p, buf, cplen);
+	buf += cplen;
+	buflen -= cplen;
+
+	while (buflen) {
+		cplen = min_t(u32, buflen, PAGE_SIZE);
+		p = xdr_reserve_space(xdr, cplen);
+		if (!p)
+			return nfserr_resource;
+
+		memcpy(p, buf, cplen);
+
+		if (cplen < PAGE_SIZE) {
+			/*
+			 * We're done, with a length that wasn't page
+			 * aligned, so possibly not word aligned. Pad
+			 * any trailing bytes with 0.
+			 */
+			xdr_encode_opaque_fixed(p, NULL, cplen);
+			break;
+		}
+
+		buflen -= PAGE_SIZE;
+		buf += PAGE_SIZE;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p, err;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p = cpu_to_be32(getxattr->getxa_len);
+
+	if (getxattr->getxa_len == 0)
+		return 0;
+
+	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
+				    getxattr->getxa_len);
+
+	kvfree(getxattr->getxa_buf);
+
+	return err;
+}
+
+static __be32
+nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &setxattr->setxa_cinfo);
+}
+
+/*
+ * See if there are cookie values that can be rejected outright.
+ */
+static __be32
+nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
+				u32 *offsetp)
+{
+	u64 cookie = listxattrs->lsxa_cookie;
+
+	/*
+	 * If the cookie is larger than the maximum number we can fit
+	 * in the buffer we just got back from vfs_listxattr, it's invalid.
+	 */
+	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
+		return nfserr_badcookie;
+
+	*offsetp = (u32)cookie;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
+	struct xdr_stream *xdr = resp->xdr;
+	u32 cookie_offset, count_offset, eof;
+	u32 left, xdrleft, slen, count;
+	u32 xdrlen, offset;
+	u64 cookie;
+	char *sp;
+	__be32 status, tmp;
+	__be64 wire_cookie;
+	__be32 *p;
+	u32 nuser;
+
+	eof = 1;
+
+	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
+	if (status)
+		goto out;
+
+	/*
+	 * Reserve space for the cookie and the name array count. Record
+	 * the offsets to save them later.
+	 */
+	cookie_offset = xdr->buf->len;
+	count_offset = cookie_offset + 8;
+	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+
+	count = 0;
+	left = listxattrs->lsxa_len;
+	sp = listxattrs->lsxa_buf;
+	nuser = 0;
+
+	/* Bytes left is maxcount - 8 (cookie) - 4 (array count) */
+	xdrleft = listxattrs->lsxa_maxcount - XDR_UNIT * 3;
+
+	while (left > 0 && xdrleft > 0) {
+		slen = strlen(sp);
+
+		/*
+		 * Check if this is a "user." attribute, skip it if not.
+		 */
+		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
+			goto contloop;
+
+		slen -= XATTR_USER_PREFIX_LEN;
+		xdrlen = 4 + ((slen + 3) & ~3);
+		/* Check if both entry and eof can fit in the XDR buffer */
+		if (xdrlen + XDR_UNIT > xdrleft) {
+			if (count == 0) {
+				/*
+				 * Can't even fit the first attribute name.
+				 */
+				status = nfserr_toosmall;
+				goto out;
+			}
+			eof = 0;
+			goto wreof;
+		}
+
+		left -= XATTR_USER_PREFIX_LEN;
+		sp += XATTR_USER_PREFIX_LEN;
+		if (nuser++ < offset)
+			goto contloop;
+
+
+		p = xdr_reserve_space(xdr, xdrlen);
+		if (!p) {
+			status = nfserr_resource;
+			goto out;
+		}
+
+		xdr_encode_opaque(p, sp, slen);
+
+		xdrleft -= xdrlen;
+		count++;
+contloop:
+		sp += slen + 1;
+		left -= slen + 1;
+	}
+
+	/*
+	 * If there were user attributes to copy, but we didn't copy
+	 * any, the offset was too large (e.g. the cookie was invalid).
+	 */
+	if (nuser > 0 && count == 0) {
+		status = nfserr_badcookie;
+		goto out;
+	}
+
+wreof:
+	p = xdr_reserve_space(xdr, 4);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+	*p = cpu_to_be32(eof);
+
+	cookie = offset + count;
+
+	wire_cookie = cpu_to_be64(cookie);
+	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &wire_cookie, 8);
+	tmp = cpu_to_be32(count);
+	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
+out:
+	if (listxattrs->lsxa_len)
+		kvfree(listxattrs->lsxa_buf);
+	return status;
+}
+
+static __be32
+nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &removexattr->rmxa_cinfo);
+}
+
+typedef __be32(*nfsd4_enc)(struct nfsd4_compoundres *, __be32, union nfsd4_op_u *u);
+
+/*
+ * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
+ * since we don't need to filter out obsolete ops as this is
+ * done in the decoding phase.
+ */
+static const nfsd4_enc nfsd4_enc_ops[] = {
+	[OP_ACCESS]		= nfsd4_encode_access,
+	[OP_CLOSE]		= nfsd4_encode_close,
+	[OP_COMMIT]		= nfsd4_encode_commit,
+	[OP_CREATE]		= nfsd4_encode_create,
+	[OP_DELEGPURGE]		= nfsd4_encode_noop,
+	[OP_DELEGRETURN]	= nfsd4_encode_noop,
+	[OP_GETATTR]		= nfsd4_encode_getattr,
+	[OP_GETFH]		= nfsd4_encode_getfh,
+	[OP_LINK]		= nfsd4_encode_link,
+	[OP_LOCK]		= nfsd4_encode_lock,
+	[OP_LOCKT]		= nfsd4_encode_lockt,
+	[OP_LOCKU]		= nfsd4_encode_locku,
+	[OP_LOOKUP]		= nfsd4_encode_noop,
+	[OP_LOOKUPP]		= nfsd4_encode_noop,
+	[OP_NVERIFY]		= nfsd4_encode_noop,
+	[OP_OPEN]		= nfsd4_encode_open,
+	[OP_OPENATTR]		= nfsd4_encode_noop,
+	[OP_OPEN_CONFIRM]	= nfsd4_encode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= nfsd4_encode_open_downgrade,
+	[OP_PUTFH]		= nfsd4_encode_noop,
+	[OP_PUTPUBFH]		= nfsd4_encode_noop,
+	[OP_PUTROOTFH]		= nfsd4_encode_noop,
+	[OP_READ]		= nfsd4_encode_read,
+	[OP_READDIR]		= nfsd4_encode_readdir,
+	[OP_READLINK]		= nfsd4_encode_readlink,
+	[OP_REMOVE]		= nfsd4_encode_remove,
+	[OP_RENAME]		= nfsd4_encode_rename,
+	[OP_RENEW]		= nfsd4_encode_noop,
+	[OP_RESTOREFH]		= nfsd4_encode_noop,
+	[OP_SAVEFH]		= nfsd4_encode_noop,
+	[OP_SECINFO]		= nfsd4_encode_secinfo,
+	[OP_SETATTR]		= nfsd4_encode_setattr,
+	[OP_SETCLIENTID]	= nfsd4_encode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = nfsd4_encode_noop,
+	[OP_VERIFY]		= nfsd4_encode_noop,
+	[OP_WRITE]		= nfsd4_encode_write,
+	[OP_RELEASE_LOCKOWNER]	= nfsd4_encode_noop,
+
+	/* NFSv4.1 operations */
+	[OP_BACKCHANNEL_CTL]	= nfsd4_encode_noop,
+	[OP_BIND_CONN_TO_SESSION] = nfsd4_encode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= nfsd4_encode_exchange_id,
+	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
+	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
+	[OP_FREE_STATEID]	= nfsd4_encode_noop,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_get_dir_delegation,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= nfsd4_encode_layoutcommit,
+	[OP_LAYOUTGET]		= nfsd4_encode_layoutget,
+	[OP_LAYOUTRETURN]	= nfsd4_encode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= nfsd4_encode_noop,
+	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= nfsd4_encode_noop,
+	[OP_LAYOUTGET]		= nfsd4_encode_noop,
+	[OP_LAYOUTRETURN]	= nfsd4_encode_noop,
+#endif
+	[OP_SECINFO_NO_NAME]	= nfsd4_encode_secinfo_no_name,
+	[OP_SEQUENCE]		= nfsd4_encode_sequence,
+	[OP_SET_SSV]		= nfsd4_encode_noop,
+	[OP_TEST_STATEID]	= nfsd4_encode_test_stateid,
+	[OP_WANT_DELEGATION]	= nfsd4_encode_noop,
+	[OP_DESTROY_CLIENTID]	= nfsd4_encode_noop,
+	[OP_RECLAIM_COMPLETE]	= nfsd4_encode_noop,
+
+	/* NFSv4.2 operations */
+	[OP_ALLOCATE]		= nfsd4_encode_noop,
+	[OP_COPY]		= nfsd4_encode_copy,
+	[OP_COPY_NOTIFY]	= nfsd4_encode_copy_notify,
+	[OP_DEALLOCATE]		= nfsd4_encode_noop,
+	[OP_IO_ADVISE]		= nfsd4_encode_noop,
+	[OP_LAYOUTERROR]	= nfsd4_encode_noop,
+	[OP_LAYOUTSTATS]	= nfsd4_encode_noop,
+	[OP_OFFLOAD_CANCEL]	= nfsd4_encode_noop,
+	[OP_OFFLOAD_STATUS]	= nfsd4_encode_offload_status,
+	[OP_READ_PLUS]		= nfsd4_encode_read_plus,
+	[OP_SEEK]		= nfsd4_encode_seek,
+	[OP_WRITE_SAME]		= nfsd4_encode_noop,
+	[OP_CLONE]		= nfsd4_encode_noop,
+
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= nfsd4_encode_getxattr,
+	[OP_SETXATTR]		= nfsd4_encode_setxattr,
+	[OP_LISTXATTRS]		= nfsd4_encode_listxattrs,
+	[OP_REMOVEXATTR]	= nfsd4_encode_removexattr,
+};
+
+/*
+ * Calculate whether we still have space to encode repsize bytes.
+ * There are two considerations:
+ *     - For NFS versions >=4.1, the size of the reply must stay within
+ *       session limits
+ *     - For all NFS versions, we must stay within limited preallocated
+ *       buffer space.
+ *
+ * This is called before the operation is processed, so can only provide
+ * an upper estimate.  For some nonidempotent operations (such as
+ * getattr), it's not necessarily a problem if that estimate is wrong,
+ * as we can fail it after processing without significant side effects.
+ */
+__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
+{
+	struct xdr_buf *buf = &resp->rqstp->rq_res;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+
+	if (buf->len + respsize <= buf->buflen)
+		return nfs_ok;
+	if (!nfsd4_has_session(&resp->cstate))
+		return nfserr_resource;
+	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
+		WARN_ON_ONCE(1);
+		return nfserr_rep_too_big_to_cache;
+	}
+	return nfserr_rep_too_big;
+}
+
+static __be32 nfsd4_map_status(__be32 status, u32 minor)
+{
+	switch (status) {
+	case nfs_ok:
+		break;
+	case nfserr_wrong_type:
+		/* RFC 8881 - 15.1.2.9 */
+		if (minor == 0)
+			status = nfserr_inval;
+		break;
+	case nfserr_symlink_not_dir:
+		status = nfserr_symlink;
+		break;
+	}
+	return status;
+}
+
+void
+nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct nfs4_stateowner *so = resp->cstate.replay_owner;
+	struct svc_rqst *rqstp = resp->rqstp;
+	const struct nfsd4_operation *opdesc = op->opdesc;
+	unsigned int op_status_offset;
+	nfsd4_enc encoder;
+
+	if (xdr_stream_encode_u32(xdr, op->opnum) != XDR_UNIT)
+		goto release;
+	op_status_offset = xdr->buf->len;
+	if (!xdr_reserve_space(xdr, XDR_UNIT))
+		goto release;
+
+	if (op->opnum == OP_ILLEGAL)
+		goto status;
+	if (op->status && opdesc &&
+			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
+		goto status;
+	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
+	       !nfsd4_enc_ops[op->opnum]);
+	encoder = nfsd4_enc_ops[op->opnum];
+	op->status = encoder(resp, op->status, &op->u);
+	if (op->status)
+		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
+	xdr_commit_encode(xdr);
+
+	/* nfsd4_check_resp_size guarantees enough room for error status */
+	if (!op->status) {
+		int space_needed = 0;
+		if (!nfsd4_last_compound_op(rqstp))
+			space_needed = COMPOUND_ERR_SLACK_SPACE;
+		op->status = nfsd4_check_resp_size(resp, space_needed);
+	}
+	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
+		struct nfsd4_slot *slot = resp->cstate.slot;
+
+		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
+			op->status = nfserr_rep_too_big_to_cache;
+		else
+			op->status = nfserr_rep_too_big;
+	}
+	if (op->status == nfserr_resource ||
+	    op->status == nfserr_rep_too_big ||
+	    op->status == nfserr_rep_too_big_to_cache) {
+		/*
+		 * The operation may have already been encoded or
+		 * partially encoded.  No op returns anything additional
+		 * in the case of one of these three errors, so we can
+		 * just truncate back to after the status.  But it's a
+		 * bug if we had to do this on a non-idempotent op:
+		 */
+		warn_on_nonidempotent_op(op);
+		xdr_truncate_encode(xdr, op_status_offset + XDR_UNIT);
+	} else if (so) {
+		int len = xdr->buf->len - (op_status_offset + XDR_UNIT);
+
+		so->so_replay.rp_status = op->status;
+		if (len > NFSD4_REPLAY_ISIZE) {
+			char *buf = kmalloc(len, GFP_KERNEL);
+
+			nfs4_replay_free_cache(&so->so_replay);
+			if (buf) {
+				so->so_replay.rp_buf = buf;
+			} else {
+				/* rp_buflen already zeroed; skip caching */
+				goto status;
+			}
+		} else if (so->so_replay.rp_buf != so->so_replay.rp_ibuf) {
+			nfs4_replay_free_cache(&so->so_replay);
+		}
+		so->so_replay.rp_buflen = len;
+		read_bytes_from_xdr_buf(xdr->buf,
+					op_status_offset + XDR_UNIT,
+					so->so_replay.rp_buf, len);
+	}
+status:
+	op->status = nfsd4_map_status(op->status,
+				      resp->cstate.minorversion);
+	write_bytes_to_xdr_buf(xdr->buf, op_status_offset,
+			       &op->status, XDR_UNIT);
+release:
+	/*
+	 * Account for pages consumed while encoding this operation.
+	 * The xdr_stream primitives don't manage rq_next_page.
+	 */
+	rqstp->rq_next_page = xdr->page_ptr + 1;
+}
+
+/**
+ * nfsd4_encode_replay - encode a result stored in the stateowner reply cache
+ * @xdr: send buffer's XDR stream
+ * @op: operation being replayed
+ *
+ * @op->replay->rp_buf contains the previously-sent already-encoded result.
+ */
+void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
+{
+	struct nfs4_replay *rp = op->replay;
+
+	trace_nfsd_stateowner_replay(op->opnum, rp);
+
+	if (xdr_stream_encode_u32(xdr, op->opnum) != XDR_UNIT)
+		return;
+	if (xdr_stream_encode_be32(xdr, rp->rp_status) != XDR_UNIT)
+		return;
+	xdr_stream_encode_opaque_fixed(xdr, rp->rp_buf, rp->rp_buflen);
+}
+
+void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	args->opcnt = 0;
+	if (args->ops != args->iops) {
+		void *old_ops = args->ops;
+
+		args->ops = args->iops;
+		kvfree_rcu_mightsleep(old_ops);
+	}
+	while (args->to_free) {
+		struct svcxdr_tmpbuf *tb = args->to_free;
+		args->to_free = tb->next;
+		kfree(tb);
+	}
+}
+
+bool
+nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	/* svcxdr_tmp_alloc */
+	args->to_free = NULL;
+
+	args->xdr = xdr;
+	args->ops = args->iops;
+	args->rqstp = rqstp;
+
+	/*
+	 * NFSv4 operation decoders can invoke svc cache lookups
+	 * that trigger svc_defer() when RQ_USEDEFERRAL is set,
+	 * setting RQ_DROPME. This creates two problems:
+	 *
+	 * 1. Non-idempotency: Compounds make it too hard to avoid
+	 *    problems if a request is deferred and replayed.
+	 *
+	 * 2. Session slot leakage (NFSv4.1+): If RQ_DROPME is set
+	 *    during decode but SEQUENCE executes successfully, the
+	 *    session slot will be marked INUSE. The request is then
+	 *    dropped before encoding, so the slot is never released,
+	 *    rendering it permanently unusable by the client.
+	 */
+	clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+
+	return nfsd4_decode_compound(args);
+}
+
+bool
+nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	__be32 *p;
+
+	/*
+	 * Send buffer space for the following items is reserved
+	 * at the top of nfsd4_proc_compound().
+	 */
+	p = resp->statusp;
+
+	*p++ = resp->cstate.status;
+	*p++ = htonl(resp->taglen);
+	memcpy(p, resp->tag, resp->taglen);
+	p += XDR_QUADLEN(resp->taglen);
+	*p++ = htonl(resp->opcnt);
+
+	nfsd4_sequence_done(resp);
+	return true;
+}
diff --git a/fs/nfsd/nfs4xdr_gen.c b/fs/nfsd/nfs4xdr_gen.c
new file mode 100644
index 000000000..d77835033
--- /dev/null
+++ b/fs/nfsd/nfs4xdr_gen.c
@@ -0,0 +1,1159 @@
+// SPDX-License-Identifier: GPL-2.0
+// Generated by xdrgen. Manual edits will be lost.
+// XDR specification file: ../../Documentation/sunrpc/xdr/nfs4_1.x
+// XDR specification modification time: Tue Jun 30 11:57:21 2026
+
+#include <linux/sunrpc/svc.h>
+
+#include "nfs4xdr_gen.h"
+
+static bool __maybe_unused
+xdrgen_decode_int32_t(struct xdr_stream *xdr, int32_t *ptr)
+{
+	return xdrgen_decode_int(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_uint32_t(struct xdr_stream *xdr, uint32_t *ptr)
+{
+	return xdrgen_decode_unsigned_int(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_int64_t(struct xdr_stream *xdr, int64_t *ptr)
+{
+	return xdrgen_decode_hyper(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_uint64_t(struct xdr_stream *xdr, uint64_t *ptr)
+{
+	return xdrgen_decode_unsigned_hyper(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_nfsstat4(struct xdr_stream *xdr, nfsstat4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case NFS4_OK:
+	case NFS4ERR_PERM:
+	case NFS4ERR_NOENT:
+	case NFS4ERR_IO:
+	case NFS4ERR_NXIO:
+	case NFS4ERR_ACCESS:
+	case NFS4ERR_EXIST:
+	case NFS4ERR_XDEV:
+	case NFS4ERR_NOTDIR:
+	case NFS4ERR_ISDIR:
+	case NFS4ERR_INVAL:
+	case NFS4ERR_FBIG:
+	case NFS4ERR_NOSPC:
+	case NFS4ERR_ROFS:
+	case NFS4ERR_MLINK:
+	case NFS4ERR_NAMETOOLONG:
+	case NFS4ERR_NOTEMPTY:
+	case NFS4ERR_DQUOT:
+	case NFS4ERR_STALE:
+	case NFS4ERR_BADHANDLE:
+	case NFS4ERR_BAD_COOKIE:
+	case NFS4ERR_NOTSUPP:
+	case NFS4ERR_TOOSMALL:
+	case NFS4ERR_SERVERFAULT:
+	case NFS4ERR_BADTYPE:
+	case NFS4ERR_DELAY:
+	case NFS4ERR_SAME:
+	case NFS4ERR_DENIED:
+	case NFS4ERR_EXPIRED:
+	case NFS4ERR_LOCKED:
+	case NFS4ERR_GRACE:
+	case NFS4ERR_FHEXPIRED:
+	case NFS4ERR_SHARE_DENIED:
+	case NFS4ERR_WRONGSEC:
+	case NFS4ERR_CLID_INUSE:
+	case NFS4ERR_RESOURCE:
+	case NFS4ERR_MOVED:
+	case NFS4ERR_NOFILEHANDLE:
+	case NFS4ERR_MINOR_VERS_MISMATCH:
+	case NFS4ERR_STALE_CLIENTID:
+	case NFS4ERR_STALE_STATEID:
+	case NFS4ERR_OLD_STATEID:
+	case NFS4ERR_BAD_STATEID:
+	case NFS4ERR_BAD_SEQID:
+	case NFS4ERR_NOT_SAME:
+	case NFS4ERR_LOCK_RANGE:
+	case NFS4ERR_SYMLINK:
+	case NFS4ERR_RESTOREFH:
+	case NFS4ERR_LEASE_MOVED:
+	case NFS4ERR_ATTRNOTSUPP:
+	case NFS4ERR_NO_GRACE:
+	case NFS4ERR_RECLAIM_BAD:
+	case NFS4ERR_RECLAIM_CONFLICT:
+	case NFS4ERR_BADXDR:
+	case NFS4ERR_LOCKS_HELD:
+	case NFS4ERR_OPENMODE:
+	case NFS4ERR_BADOWNER:
+	case NFS4ERR_BADCHAR:
+	case NFS4ERR_BADNAME:
+	case NFS4ERR_BAD_RANGE:
+	case NFS4ERR_LOCK_NOTSUPP:
+	case NFS4ERR_OP_ILLEGAL:
+	case NFS4ERR_DEADLOCK:
+	case NFS4ERR_FILE_OPEN:
+	case NFS4ERR_ADMIN_REVOKED:
+	case NFS4ERR_CB_PATH_DOWN:
+	case NFS4ERR_BADIOMODE:
+	case NFS4ERR_BADLAYOUT:
+	case NFS4ERR_BAD_SESSION_DIGEST:
+	case NFS4ERR_BADSESSION:
+	case NFS4ERR_BADSLOT:
+	case NFS4ERR_COMPLETE_ALREADY:
+	case NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case NFS4ERR_DELEG_ALREADY_WANTED:
+	case NFS4ERR_BACK_CHAN_BUSY:
+	case NFS4ERR_LAYOUTTRYLATER:
+	case NFS4ERR_LAYOUTUNAVAILABLE:
+	case NFS4ERR_NOMATCHING_LAYOUT:
+	case NFS4ERR_RECALLCONFLICT:
+	case NFS4ERR_UNKNOWN_LAYOUTTYPE:
+	case NFS4ERR_SEQ_MISORDERED:
+	case NFS4ERR_SEQUENCE_POS:
+	case NFS4ERR_REQ_TOO_BIG:
+	case NFS4ERR_REP_TOO_BIG:
+	case NFS4ERR_REP_TOO_BIG_TO_CACHE:
+	case NFS4ERR_RETRY_UNCACHED_REP:
+	case NFS4ERR_UNSAFE_COMPOUND:
+	case NFS4ERR_TOO_MANY_OPS:
+	case NFS4ERR_OP_NOT_IN_SESSION:
+	case NFS4ERR_HASH_ALG_UNSUPP:
+	case NFS4ERR_CLIENTID_BUSY:
+	case NFS4ERR_PNFS_IO_HOLE:
+	case NFS4ERR_SEQ_FALSE_RETRY:
+	case NFS4ERR_BAD_HIGH_SLOT:
+	case NFS4ERR_DEADSESSION:
+	case NFS4ERR_ENCR_ALG_UNSUPP:
+	case NFS4ERR_PNFS_NO_LAYOUT:
+	case NFS4ERR_NOT_ONLY_OP:
+	case NFS4ERR_WRONG_CRED:
+	case NFS4ERR_WRONG_TYPE:
+	case NFS4ERR_DIRDELEG_UNAVAIL:
+	case NFS4ERR_REJECT_DELEG:
+	case NFS4ERR_RETURNCONFLICT:
+	case NFS4ERR_DELEG_REVOKED:
+	case NFS4ERR_PARTNER_NOTSUPP:
+	case NFS4ERR_PARTNER_NO_AUTH:
+	case NFS4ERR_UNION_NOTSUPP:
+	case NFS4ERR_OFFLOAD_DENIED:
+	case NFS4ERR_WRONG_LFS:
+	case NFS4ERR_BADLABEL:
+	case NFS4ERR_OFFLOAD_NO_REQS:
+	case NFS4ERR_NOXATTR:
+	case NFS4ERR_XATTR2BIG:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_attrlist4(struct xdr_stream *xdr, attrlist4 *ptr)
+{
+	return xdrgen_decode_opaque(xdr, ptr, 0);
+}
+
+static bool __maybe_unused
+xdrgen_decode_bitmap4(struct xdr_stream *xdr, bitmap4 *ptr)
+{
+	if (xdr_stream_decode_u32(xdr, &ptr->count) < 0)
+		return false;
+	for (u32 i = 0; i < ptr->count; i++)
+		if (!xdrgen_decode_uint32_t(xdr, &ptr->element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_verifier4(struct xdr_stream *xdr, verifier4 *ptr)
+{
+	return xdr_stream_decode_opaque_fixed(xdr, ptr, NFS4_VERIFIER_SIZE) == 0;
+}
+
+static bool __maybe_unused
+xdrgen_decode_nfs_cookie4(struct xdr_stream *xdr, nfs_cookie4 *ptr)
+{
+	return xdrgen_decode_uint64_t(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_nfs_fh4(struct xdr_stream *xdr, nfs_fh4 *ptr)
+{
+	return xdrgen_decode_opaque(xdr, ptr, NFS4_FHSIZE);
+}
+
+static bool __maybe_unused
+xdrgen_decode_utf8string(struct xdr_stream *xdr, utf8string *ptr)
+{
+	return xdrgen_decode_opaque(xdr, ptr, 0);
+}
+
+static bool __maybe_unused
+xdrgen_decode_utf8str_cis(struct xdr_stream *xdr, utf8str_cis *ptr)
+{
+	return xdrgen_decode_utf8string(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_utf8str_cs(struct xdr_stream *xdr, utf8str_cs *ptr)
+{
+	return xdrgen_decode_utf8string(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_utf8str_mixed(struct xdr_stream *xdr, utf8str_mixed *ptr)
+{
+	return xdrgen_decode_utf8string(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_component4(struct xdr_stream *xdr, component4 *ptr)
+{
+	return xdrgen_decode_utf8str_cs(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_linktext4(struct xdr_stream *xdr, linktext4 *ptr)
+{
+	return xdrgen_decode_utf8str_cs(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_pathname4(struct xdr_stream *xdr, pathname4 *ptr)
+{
+	if (xdr_stream_decode_u32(xdr, &ptr->count) < 0)
+		return false;
+	for (u32 i = 0; i < ptr->count; i++)
+		if (!xdrgen_decode_component4(xdr, &ptr->element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_nfstime4(struct xdr_stream *xdr, struct nfstime4 *ptr)
+{
+	if (!xdrgen_decode_int64_t(xdr, &ptr->seconds))
+		return false;
+	if (!xdrgen_decode_uint32_t(xdr, &ptr->nseconds))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4(struct xdr_stream *xdr, struct fattr4 *ptr)
+{
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->attrmask))
+		return false;
+	if (!xdrgen_decode_attrlist4(xdr, &ptr->attr_vals))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_stateid4(struct xdr_stream *xdr, struct stateid4 *ptr)
+{
+	if (!xdrgen_decode_uint32_t(xdr, &ptr->seqid))
+		return false;
+	if (xdr_stream_decode_opaque_fixed(xdr, ptr->other, 12) < 0)
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4_offline(struct xdr_stream *xdr, fattr4_offline *ptr)
+{
+	return xdrgen_decode_bool(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_arguments4(struct xdr_stream *xdr, struct open_arguments4 *ptr)
+{
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->oa_share_access))
+		return false;
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->oa_share_deny))
+		return false;
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->oa_share_access_want))
+		return false;
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->oa_open_claim))
+		return false;
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->oa_create_mode))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_args_share_access4(struct xdr_stream *xdr, open_args_share_access4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_ARGS_SHARE_ACCESS_READ:
+	case OPEN_ARGS_SHARE_ACCESS_WRITE:
+	case OPEN_ARGS_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_args_share_deny4(struct xdr_stream *xdr, open_args_share_deny4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_ARGS_SHARE_DENY_NONE:
+	case OPEN_ARGS_SHARE_DENY_READ:
+	case OPEN_ARGS_SHARE_DENY_WRITE:
+	case OPEN_ARGS_SHARE_DENY_BOTH:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_args_share_access_want4(struct xdr_stream *xdr, open_args_share_access_want4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_ARGS_SHARE_ACCESS_WANT_ANY_DELEG:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_NO_DELEG:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_CANCEL:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_PUSH_DELEG_WHEN_UNCONTENDED:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS:
+	case OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_DELEGATION:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_args_open_claim4(struct xdr_stream *xdr, open_args_open_claim4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_ARGS_OPEN_CLAIM_NULL:
+	case OPEN_ARGS_OPEN_CLAIM_PREVIOUS:
+	case OPEN_ARGS_OPEN_CLAIM_DELEGATE_CUR:
+	case OPEN_ARGS_OPEN_CLAIM_DELEGATE_PREV:
+	case OPEN_ARGS_OPEN_CLAIM_FH:
+	case OPEN_ARGS_OPEN_CLAIM_DELEG_CUR_FH:
+	case OPEN_ARGS_OPEN_CLAIM_DELEG_PREV_FH:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_open_args_createmode4(struct xdr_stream *xdr, open_args_createmode4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_ARGS_CREATEMODE_UNCHECKED4:
+	case OPEN_ARGS_CREATE_MODE_GUARDED:
+	case OPEN_ARGS_CREATEMODE_EXCLUSIVE4:
+	case OPEN_ARGS_CREATE_MODE_EXCLUSIVE4_1:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+bool
+xdrgen_decode_fattr4_open_arguments(struct xdr_stream *xdr, fattr4_open_arguments *ptr)
+{
+	return xdrgen_decode_open_arguments4(xdr, ptr);
+}
+
+/*
+ * Determine what OPEN supports.
+ */
+
+bool
+xdrgen_decode_fattr4_time_deleg_access(struct xdr_stream *xdr, fattr4_time_deleg_access *ptr)
+{
+	return xdrgen_decode_nfstime4(xdr, ptr);
+}
+
+bool
+xdrgen_decode_fattr4_time_deleg_modify(struct xdr_stream *xdr, fattr4_time_deleg_modify *ptr)
+{
+	return xdrgen_decode_nfstime4(xdr, ptr);
+}
+
+/*
+ * New RECOMMENDED Attribute for
+ * delegation caching of times
+ */
+
+static bool __maybe_unused
+xdrgen_decode_open_delegation_type4(struct xdr_stream *xdr, open_delegation_type4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case OPEN_DELEGATE_NONE:
+	case OPEN_DELEGATE_READ:
+	case OPEN_DELEGATE_WRITE:
+	case OPEN_DELEGATE_NONE_EXT:
+	case OPEN_DELEGATE_READ_ATTRS_DELEG:
+	case OPEN_DELEGATE_WRITE_ATTRS_DELEG:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+bool
+xdrgen_decode_aclmodel4(struct xdr_stream *xdr, aclmodel4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case ACL_MODEL_NFS4:
+	case ACL_MODEL_POSIX_DRAFT:
+	case ACL_MODEL_NONE:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+bool
+xdrgen_decode_aclscope4(struct xdr_stream *xdr, aclscope4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case ACL_SCOPE_FILE_OBJECT:
+	case ACL_SCOPE_FILE_SYSTEM:
+	case ACL_SCOPE_SERVER:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+bool
+xdrgen_decode_posixacetag4(struct xdr_stream *xdr, posixacetag4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case POSIXACE4_TAG_USER_OBJ:
+	case POSIXACE4_TAG_USER:
+	case POSIXACE4_TAG_GROUP_OBJ:
+	case POSIXACE4_TAG_GROUP:
+	case POSIXACE4_TAG_MASK:
+	case POSIXACE4_TAG_OTHER:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+bool
+xdrgen_decode_posixaceperm4(struct xdr_stream *xdr, posixaceperm4 *ptr)
+{
+	return xdrgen_decode_uint32_t(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_posixace4(struct xdr_stream *xdr, struct posixace4 *ptr)
+{
+	if (!xdrgen_decode_posixacetag4(xdr, &ptr->tag))
+		return false;
+	if (!xdrgen_decode_posixaceperm4(xdr, &ptr->perm))
+		return false;
+	if (!xdrgen_decode_utf8str_mixed(xdr, &ptr->who))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4_acl_trueform(struct xdr_stream *xdr, fattr4_acl_trueform *ptr)
+{
+	return xdrgen_decode_aclmodel4(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4_acl_trueform_scope(struct xdr_stream *xdr, fattr4_acl_trueform_scope *ptr)
+{
+	return xdrgen_decode_aclscope4(xdr, ptr);
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4_posix_default_acl(struct xdr_stream *xdr, fattr4_posix_default_acl *ptr)
+{
+	if (xdr_stream_decode_u32(xdr, &ptr->count) < 0)
+		return false;
+	for (u32 i = 0; i < ptr->count; i++)
+		if (!xdrgen_decode_posixace4(xdr, &ptr->element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_fattr4_posix_access_acl(struct xdr_stream *xdr, fattr4_posix_access_acl *ptr)
+{
+	if (xdr_stream_decode_u32(xdr, &ptr->count) < 0)
+		return false;
+	for (u32 i = 0; i < ptr->count; i++)
+		if (!xdrgen_decode_posixace4(xdr, &ptr->element[i]))
+			return false;
+	return true;
+}
+
+/*
+ * New for POSIX ACL extension
+ */
+
+static bool __maybe_unused
+xdrgen_decode_notify_type4(struct xdr_stream *xdr, notify_type4 *ptr)
+{
+	u32 val;
+
+	if (xdr_stream_decode_u32(xdr, &val) < 0)
+		return false;
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+	case NOTIFY4_CHANGE_CHILD_ATTRS:
+	case NOTIFY4_CHANGE_DIR_ATTRS:
+	case NOTIFY4_REMOVE_ENTRY:
+	case NOTIFY4_ADD_ENTRY:
+	case NOTIFY4_RENAME_ENTRY:
+	case NOTIFY4_CHANGE_COOKIE_VERIFIER:
+	case NOTIFY4_GFLAG_EXTEND:
+	case NOTIFY4_AUFLAG_VALID:
+	case NOTIFY4_AUFLAG_USER:
+	case NOTIFY4_AUFLAG_GROUP:
+	case NOTIFY4_AUFLAG_OTHER:
+	case NOTIFY4_CHANGE_AUTH:
+	case NOTIFY4_CFLAG_ORDER:
+	case NOTIFY4_AUFLAG_GANOW:
+	case NOTIFY4_AUFLAG_GALATER:
+	case NOTIFY4_CHANGE_GA:
+	case NOTIFY4_CHANGE_AMASK:
+		break;
+	default:
+		return false;
+	}
+	*ptr = val;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_notify_entry4(struct xdr_stream *xdr, struct notify_entry4 *ptr)
+{
+	if (!xdrgen_decode_component4(xdr, &ptr->ne_file))
+		return false;
+	if (!xdrgen_decode_fattr4(xdr, &ptr->ne_attrs))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_prev_entry4(struct xdr_stream *xdr, struct prev_entry4 *ptr)
+{
+	if (!xdrgen_decode_notify_entry4(xdr, &ptr->pe_prev_entry))
+		return false;
+	if (!xdrgen_decode_nfs_cookie4(xdr, &ptr->pe_prev_entry_cookie))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_decode_notify_remove4(struct xdr_stream *xdr, struct notify_remove4 *ptr)
+{
+	if (!xdrgen_decode_notify_entry4(xdr, &ptr->nrm_old_entry))
+		return false;
+	if (!xdrgen_decode_nfs_cookie4(xdr, &ptr->nrm_old_entry_cookie))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_decode_notify_add4(struct xdr_stream *xdr, struct notify_add4 *ptr)
+{
+	if (xdr_stream_decode_u32(xdr, &ptr->nad_old_entry.count) < 0)
+		return false;
+	if (ptr->nad_old_entry.count > 1)
+		return false;
+	for (u32 i = 0; i < ptr->nad_old_entry.count; i++)
+		if (!xdrgen_decode_notify_remove4(xdr, &ptr->nad_old_entry.element[i]))
+			return false;
+	if (!xdrgen_decode_notify_entry4(xdr, &ptr->nad_new_entry))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &ptr->nad_new_entry_cookie.count) < 0)
+		return false;
+	if (ptr->nad_new_entry_cookie.count > 1)
+		return false;
+	for (u32 i = 0; i < ptr->nad_new_entry_cookie.count; i++)
+		if (!xdrgen_decode_nfs_cookie4(xdr, &ptr->nad_new_entry_cookie.element[i]))
+			return false;
+	if (xdr_stream_decode_u32(xdr, &ptr->nad_prev_entry.count) < 0)
+		return false;
+	if (ptr->nad_prev_entry.count > 1)
+		return false;
+	for (u32 i = 0; i < ptr->nad_prev_entry.count; i++)
+		if (!xdrgen_decode_prev_entry4(xdr, &ptr->nad_prev_entry.element[i]))
+			return false;
+	if (!xdrgen_decode_bool(xdr, &ptr->nad_last_entry))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_decode_notify_attr4(struct xdr_stream *xdr, struct notify_attr4 *ptr)
+{
+	if (!xdrgen_decode_notify_entry4(xdr, &ptr->na_changed_entry))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_decode_notify_rename4(struct xdr_stream *xdr, struct notify_rename4 *ptr)
+{
+	if (!xdrgen_decode_notify_remove4(xdr, &ptr->nrn_old_entry))
+		return false;
+	if (!xdrgen_decode_notify_add4(xdr, &ptr->nrn_new_entry))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_notify_verifier4(struct xdr_stream *xdr, struct notify_verifier4 *ptr)
+{
+	if (!xdrgen_decode_verifier4(xdr, &ptr->nv_old_cookieverf))
+		return false;
+	if (!xdrgen_decode_verifier4(xdr, &ptr->nv_new_cookieverf))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_notifylist4(struct xdr_stream *xdr, notifylist4 *ptr)
+{
+	return xdrgen_decode_opaque(xdr, ptr, 0);
+}
+
+static bool __maybe_unused
+xdrgen_decode_notify4(struct xdr_stream *xdr, struct notify4 *ptr)
+{
+	if (!xdrgen_decode_bitmap4(xdr, &ptr->notify_mask))
+		return false;
+	if (!xdrgen_decode_notifylist4(xdr, &ptr->notify_vals))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_decode_CB_NOTIFY4args(struct xdr_stream *xdr, struct CB_NOTIFY4args *ptr)
+{
+	if (!xdrgen_decode_stateid4(xdr, &ptr->cna_stateid))
+		return false;
+	if (!xdrgen_decode_nfs_fh4(xdr, &ptr->cna_fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &ptr->cna_changes.count) < 0)
+		return false;
+	for (u32 i = 0; i < ptr->cna_changes.count; i++)
+		if (!xdrgen_decode_notify4(xdr, &ptr->cna_changes.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_decode_CB_NOTIFY4res(struct xdr_stream *xdr, struct CB_NOTIFY4res *ptr)
+{
+	if (!xdrgen_decode_nfsstat4(xdr, &ptr->cnr_status))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_int32_t(struct xdr_stream *xdr, const int32_t value)
+{
+	return xdrgen_encode_int(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_uint32_t(struct xdr_stream *xdr, const uint32_t value)
+{
+	return xdrgen_encode_unsigned_int(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_int64_t(struct xdr_stream *xdr, const int64_t value)
+{
+	return xdrgen_encode_hyper(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_uint64_t(struct xdr_stream *xdr, const uint64_t value)
+{
+	return xdrgen_encode_unsigned_hyper(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_nfsstat4(struct xdr_stream *xdr, nfsstat4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_attrlist4(struct xdr_stream *xdr, const attrlist4 value)
+{
+	return xdr_stream_encode_opaque(xdr, value.data, value.len) >= 0;
+}
+
+static bool __maybe_unused
+xdrgen_encode_bitmap4(struct xdr_stream *xdr, const bitmap4 value)
+{
+	if (xdr_stream_encode_u32(xdr, value.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value.count; i++)
+		if (!xdrgen_encode_uint32_t(xdr, value.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_verifier4(struct xdr_stream *xdr, const verifier4 value)
+{
+	return xdr_stream_encode_opaque_fixed(xdr, value, NFS4_VERIFIER_SIZE) >= 0;
+}
+
+static bool __maybe_unused
+xdrgen_encode_nfs_cookie4(struct xdr_stream *xdr, const nfs_cookie4 value)
+{
+	return xdrgen_encode_uint64_t(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_nfs_fh4(struct xdr_stream *xdr, const nfs_fh4 value)
+{
+	return xdr_stream_encode_opaque(xdr, value.data, value.len) >= 0;
+}
+
+static bool __maybe_unused
+xdrgen_encode_utf8string(struct xdr_stream *xdr, const utf8string value)
+{
+	return xdr_stream_encode_opaque(xdr, value.data, value.len) >= 0;
+}
+
+static bool __maybe_unused
+xdrgen_encode_utf8str_cis(struct xdr_stream *xdr, const utf8str_cis value)
+{
+	return xdrgen_encode_utf8string(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_utf8str_cs(struct xdr_stream *xdr, const utf8str_cs value)
+{
+	return xdrgen_encode_utf8string(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_utf8str_mixed(struct xdr_stream *xdr, const utf8str_mixed value)
+{
+	return xdrgen_encode_utf8string(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_component4(struct xdr_stream *xdr, const component4 value)
+{
+	return xdrgen_encode_utf8str_cs(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_linktext4(struct xdr_stream *xdr, const linktext4 value)
+{
+	return xdrgen_encode_utf8str_cs(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_pathname4(struct xdr_stream *xdr, const pathname4 value)
+{
+	if (xdr_stream_encode_u32(xdr, value.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value.count; i++)
+		if (!xdrgen_encode_component4(xdr, value.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_nfstime4(struct xdr_stream *xdr, const struct nfstime4 *value)
+{
+	if (!xdrgen_encode_int64_t(xdr, value->seconds))
+		return false;
+	if (!xdrgen_encode_uint32_t(xdr, value->nseconds))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4(struct xdr_stream *xdr, const struct fattr4 *value)
+{
+	if (!xdrgen_encode_bitmap4(xdr, value->attrmask))
+		return false;
+	if (!xdrgen_encode_attrlist4(xdr, value->attr_vals))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_stateid4(struct xdr_stream *xdr, const struct stateid4 *value)
+{
+	if (!xdrgen_encode_uint32_t(xdr, value->seqid))
+		return false;
+	if (xdr_stream_encode_opaque_fixed(xdr, value->other, 12) < 0)
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4_offline(struct xdr_stream *xdr, const fattr4_offline value)
+{
+	return xdrgen_encode_bool(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_arguments4(struct xdr_stream *xdr, const struct open_arguments4 *value)
+{
+	if (!xdrgen_encode_bitmap4(xdr, value->oa_share_access))
+		return false;
+	if (!xdrgen_encode_bitmap4(xdr, value->oa_share_deny))
+		return false;
+	if (!xdrgen_encode_bitmap4(xdr, value->oa_share_access_want))
+		return false;
+	if (!xdrgen_encode_bitmap4(xdr, value->oa_open_claim))
+		return false;
+	if (!xdrgen_encode_bitmap4(xdr, value->oa_create_mode))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_args_share_access4(struct xdr_stream *xdr, open_args_share_access4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_args_share_deny4(struct xdr_stream *xdr, open_args_share_deny4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_args_share_access_want4(struct xdr_stream *xdr, open_args_share_access_want4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_args_open_claim4(struct xdr_stream *xdr, open_args_open_claim4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_args_createmode4(struct xdr_stream *xdr, open_args_createmode4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+bool
+xdrgen_encode_fattr4_open_arguments(struct xdr_stream *xdr, const fattr4_open_arguments *value)
+{
+	return xdrgen_encode_open_arguments4(xdr, value);
+}
+
+bool
+xdrgen_encode_fattr4_time_deleg_access(struct xdr_stream *xdr, const fattr4_time_deleg_access *value)
+{
+	return xdrgen_encode_nfstime4(xdr, value);
+}
+
+bool
+xdrgen_encode_fattr4_time_deleg_modify(struct xdr_stream *xdr, const fattr4_time_deleg_modify *value)
+{
+	return xdrgen_encode_nfstime4(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_open_delegation_type4(struct xdr_stream *xdr, open_delegation_type4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+bool
+xdrgen_encode_aclmodel4(struct xdr_stream *xdr, aclmodel4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+bool
+xdrgen_encode_aclscope4(struct xdr_stream *xdr, aclscope4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+bool
+xdrgen_encode_posixacetag4(struct xdr_stream *xdr, posixacetag4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+bool
+xdrgen_encode_posixaceperm4(struct xdr_stream *xdr, const posixaceperm4 value)
+{
+	return xdrgen_encode_uint32_t(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_posixace4(struct xdr_stream *xdr, const struct posixace4 *value)
+{
+	if (!xdrgen_encode_posixacetag4(xdr, value->tag))
+		return false;
+	if (!xdrgen_encode_posixaceperm4(xdr, value->perm))
+		return false;
+	if (!xdrgen_encode_utf8str_mixed(xdr, value->who))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4_acl_trueform(struct xdr_stream *xdr, const fattr4_acl_trueform value)
+{
+	return xdrgen_encode_aclmodel4(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4_acl_trueform_scope(struct xdr_stream *xdr, const fattr4_acl_trueform_scope value)
+{
+	return xdrgen_encode_aclscope4(xdr, value);
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4_posix_default_acl(struct xdr_stream *xdr, const fattr4_posix_default_acl value)
+{
+	if (xdr_stream_encode_u32(xdr, value.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value.count; i++)
+		if (!xdrgen_encode_posixace4(xdr, &value.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_fattr4_posix_access_acl(struct xdr_stream *xdr, const fattr4_posix_access_acl value)
+{
+	if (xdr_stream_encode_u32(xdr, value.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value.count; i++)
+		if (!xdrgen_encode_posixace4(xdr, &value.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_notify_type4(struct xdr_stream *xdr, notify_type4 value)
+{
+	return xdr_stream_encode_u32(xdr, value) == XDR_UNIT;
+}
+
+static bool __maybe_unused
+xdrgen_encode_notify_entry4(struct xdr_stream *xdr, const struct notify_entry4 *value)
+{
+	if (!xdrgen_encode_component4(xdr, value->ne_file))
+		return false;
+	if (!xdrgen_encode_fattr4(xdr, &value->ne_attrs))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_prev_entry4(struct xdr_stream *xdr, const struct prev_entry4 *value)
+{
+	if (!xdrgen_encode_notify_entry4(xdr, &value->pe_prev_entry))
+		return false;
+	if (!xdrgen_encode_nfs_cookie4(xdr, value->pe_prev_entry_cookie))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_encode_notify_remove4(struct xdr_stream *xdr, const struct notify_remove4 *value)
+{
+	if (!xdrgen_encode_notify_entry4(xdr, &value->nrm_old_entry))
+		return false;
+	if (!xdrgen_encode_nfs_cookie4(xdr, value->nrm_old_entry_cookie))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_encode_notify_add4(struct xdr_stream *xdr, const struct notify_add4 *value)
+{
+	if (value->nad_old_entry.count > 1)
+		return false;
+	if (xdr_stream_encode_u32(xdr, value->nad_old_entry.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value->nad_old_entry.count; i++)
+		if (!xdrgen_encode_notify_remove4(xdr, &value->nad_old_entry.element[i]))
+			return false;
+	if (!xdrgen_encode_notify_entry4(xdr, &value->nad_new_entry))
+		return false;
+	if (value->nad_new_entry_cookie.count > 1)
+		return false;
+	if (xdr_stream_encode_u32(xdr, value->nad_new_entry_cookie.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value->nad_new_entry_cookie.count; i++)
+		if (!xdrgen_encode_nfs_cookie4(xdr, value->nad_new_entry_cookie.element[i]))
+			return false;
+	if (value->nad_prev_entry.count > 1)
+		return false;
+	if (xdr_stream_encode_u32(xdr, value->nad_prev_entry.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value->nad_prev_entry.count; i++)
+		if (!xdrgen_encode_prev_entry4(xdr, &value->nad_prev_entry.element[i]))
+			return false;
+	if (!xdrgen_encode_bool(xdr, value->nad_last_entry))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_encode_notify_attr4(struct xdr_stream *xdr, const struct notify_attr4 *value)
+{
+	if (!xdrgen_encode_notify_entry4(xdr, &value->na_changed_entry))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_encode_notify_rename4(struct xdr_stream *xdr, const struct notify_rename4 *value)
+{
+	if (!xdrgen_encode_notify_remove4(xdr, &value->nrn_old_entry))
+		return false;
+	if (!xdrgen_encode_notify_add4(xdr, &value->nrn_new_entry))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_notify_verifier4(struct xdr_stream *xdr, const struct notify_verifier4 *value)
+{
+	if (!xdrgen_encode_verifier4(xdr, value->nv_old_cookieverf))
+		return false;
+	if (!xdrgen_encode_verifier4(xdr, value->nv_new_cookieverf))
+		return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_notifylist4(struct xdr_stream *xdr, const notifylist4 value)
+{
+	return xdr_stream_encode_opaque(xdr, value.data, value.len) >= 0;
+}
+
+static bool __maybe_unused
+xdrgen_encode_notify4(struct xdr_stream *xdr, const struct notify4 *value)
+{
+	if (!xdrgen_encode_bitmap4(xdr, value->notify_mask))
+		return false;
+	if (!xdrgen_encode_notifylist4(xdr, value->notify_vals))
+		return false;
+	return true;
+}
+
+bool
+xdrgen_encode_CB_NOTIFY4args(struct xdr_stream *xdr, const struct CB_NOTIFY4args *value)
+{
+	if (!xdrgen_encode_stateid4(xdr, &value->cna_stateid))
+		return false;
+	if (!xdrgen_encode_nfs_fh4(xdr, value->cna_fh))
+		return false;
+	if (xdr_stream_encode_u32(xdr, value->cna_changes.count) != XDR_UNIT)
+		return false;
+	for (u32 i = 0; i < value->cna_changes.count; i++)
+		if (!xdrgen_encode_notify4(xdr, &value->cna_changes.element[i]))
+			return false;
+	return true;
+}
+
+static bool __maybe_unused
+xdrgen_encode_CB_NOTIFY4res(struct xdr_stream *xdr, const struct CB_NOTIFY4res *value)
+{
+	if (!xdrgen_encode_nfsstat4(xdr, value->cnr_status))
+		return false;
+	return true;
+}
diff --git a/fs/nfsd/nfs4xdr_gen.h b/fs/nfsd/nfs4xdr_gen.h
new file mode 100644
index 000000000..21ca82078
--- /dev/null
+++ b/fs/nfsd/nfs4xdr_gen.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Generated by xdrgen. Manual edits will be lost. */
+/* XDR specification file: ../../Documentation/sunrpc/xdr/nfs4_1.x */
+/* XDR specification modification time: Tue Jun 30 11:57:21 2026 */
+
+#ifndef _LINUX_XDRGEN_NFS4_1_DECL_H
+#define _LINUX_XDRGEN_NFS4_1_DECL_H
+
+#include <linux/types.h>
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/xdrgen/_defs.h>
+#include <linux/sunrpc/xdrgen/_builtins.h>
+#include <linux/sunrpc/xdrgen/nfs4_1.h>
+
+bool xdrgen_decode_fattr4_open_arguments(struct xdr_stream *xdr, fattr4_open_arguments *ptr);
+bool xdrgen_encode_fattr4_open_arguments(struct xdr_stream *xdr, const fattr4_open_arguments *value);
+
+bool xdrgen_decode_fattr4_time_deleg_access(struct xdr_stream *xdr, fattr4_time_deleg_access *ptr);
+bool xdrgen_encode_fattr4_time_deleg_access(struct xdr_stream *xdr, const fattr4_time_deleg_access *value);
+
+bool xdrgen_decode_fattr4_time_deleg_modify(struct xdr_stream *xdr, fattr4_time_deleg_modify *ptr);
+bool xdrgen_encode_fattr4_time_deleg_modify(struct xdr_stream *xdr, const fattr4_time_deleg_modify *value);
+
+bool xdrgen_decode_aclmodel4(struct xdr_stream *xdr, aclmodel4 *ptr);
+bool xdrgen_encode_aclmodel4(struct xdr_stream *xdr, aclmodel4 value);
+
+bool xdrgen_decode_aclscope4(struct xdr_stream *xdr, aclscope4 *ptr);
+bool xdrgen_encode_aclscope4(struct xdr_stream *xdr, aclscope4 value);
+
+bool xdrgen_decode_posixacetag4(struct xdr_stream *xdr, posixacetag4 *ptr);
+bool xdrgen_encode_posixacetag4(struct xdr_stream *xdr, posixacetag4 value);
+
+bool xdrgen_decode_posixaceperm4(struct xdr_stream *xdr, posixaceperm4 *ptr);
+bool xdrgen_encode_posixaceperm4(struct xdr_stream *xdr, const posixaceperm4 value);
+
+
+bool xdrgen_decode_notify_remove4(struct xdr_stream *xdr, struct notify_remove4 *ptr);
+bool xdrgen_encode_notify_remove4(struct xdr_stream *xdr, const struct notify_remove4 *value);
+
+bool xdrgen_decode_notify_add4(struct xdr_stream *xdr, struct notify_add4 *ptr);
+bool xdrgen_encode_notify_add4(struct xdr_stream *xdr, const struct notify_add4 *value);
+
+bool xdrgen_decode_notify_attr4(struct xdr_stream *xdr, struct notify_attr4 *ptr);
+bool xdrgen_encode_notify_attr4(struct xdr_stream *xdr, const struct notify_attr4 *value);
+
+bool xdrgen_decode_notify_rename4(struct xdr_stream *xdr, struct notify_rename4 *ptr);
+bool xdrgen_encode_notify_rename4(struct xdr_stream *xdr, const struct notify_rename4 *value);
+
+bool xdrgen_decode_CB_NOTIFY4args(struct xdr_stream *xdr, struct CB_NOTIFY4args *ptr);
+bool xdrgen_encode_CB_NOTIFY4args(struct xdr_stream *xdr, const struct CB_NOTIFY4args *value);
+
+#endif /* _LINUX_XDRGEN_NFS4_1_DECL_H */
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
new file mode 100644
index 000000000..c7db532c8
--- /dev/null
+++ b/fs/nfsd/nfscache.c
@@ -0,0 +1,669 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Request reply cache. This is currently a global cache, but this may
+ * change in the future and be a per-client cache.
+ *
+ * This code is heavily inspired by the 44BSD implementation, although
+ * it does things a bit differently.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/highmem.h>
+#include <linux/log2.h>
+#include <linux/hash.h>
+#include <net/checksum.h>
+
+#include "nfsd.h"
+#include "netns.h"
+#include "stats.h"
+#include "cache.h"
+#include "trace.h"
+
+/*
+ * We use this value to determine the number of hash buckets from the max
+ * cache size, the idea being that when the cache is at its maximum number
+ * of entries, then this should be the average number of entries per bucket.
+ */
+#define TARGET_BUCKET_SIZE	8
+
+struct nfsd_drc_bucket {
+	struct rb_root rb_head;
+	struct list_head lru_head;
+	spinlock_t cache_lock;
+};
+
+static struct kmem_cache	*drc_slab;
+
+static int	nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
+static unsigned long nfsd_reply_cache_count(struct shrinker *shrink,
+					    struct shrink_control *sc);
+static unsigned long nfsd_reply_cache_scan(struct shrinker *shrink,
+					   struct shrink_control *sc);
+
+/*
+ * Put a cap on the size of the DRC based on the amount of available
+ * low memory in the machine.
+ *
+ *  64MB:    8192
+ * 128MB:   11585
+ * 256MB:   16384
+ * 512MB:   23170
+ *   1GB:   32768
+ *   2GB:   46340
+ *   4GB:   65536
+ *   8GB:   92681
+ *  16GB:  131072
+ *
+ * ...with a hard cap of 256k entries. In the worst case, each entry will be
+ * ~1k, so the above numbers should give a rough max of the amount of memory
+ * used in k.
+ *
+ * XXX: these limits are per-container, so memory used will increase
+ * linearly with number of containers.  Maybe that's OK.
+ */
+static unsigned int
+nfsd_cache_size_limit(void)
+{
+	unsigned int limit;
+	unsigned long low_pages = totalram_pages() - totalhigh_pages();
+
+	limit = (16 * int_sqrt(low_pages)) << (PAGE_SHIFT-10);
+	return min_t(unsigned int, limit, 256*1024);
+}
+
+/*
+ * Compute the number of hash buckets we need. Divide the max cachesize by
+ * the "target" max bucket size, and round up to next power of two.
+ */
+static unsigned int
+nfsd_hashsize(unsigned int limit)
+{
+	return roundup_pow_of_two(limit / TARGET_BUCKET_SIZE);
+}
+
+static struct nfsd_cacherep *
+nfsd_cacherep_alloc(struct svc_rqst *rqstp, __wsum csum,
+		    struct nfsd_net *nn)
+{
+	struct nfsd_cacherep *rp;
+
+	rp = kmem_cache_alloc(drc_slab, GFP_KERNEL);
+	if (rp) {
+		rp->c_state = RC_UNUSED;
+		rp->c_type = RC_NOCACHE;
+		RB_CLEAR_NODE(&rp->c_node);
+		INIT_LIST_HEAD(&rp->c_lru);
+
+		memset(&rp->c_key, 0, sizeof(rp->c_key));
+		rp->c_key.k_xid = rqstp->rq_xid;
+		rp->c_key.k_proc = rqstp->rq_proc;
+		rpc_copy_addr((struct sockaddr *)&rp->c_key.k_addr, svc_addr(rqstp));
+		rpc_set_port((struct sockaddr *)&rp->c_key.k_addr, rpc_get_port(svc_addr(rqstp)));
+		rp->c_key.k_prot = rqstp->rq_prot;
+		rp->c_key.k_vers = rqstp->rq_vers;
+		rp->c_key.k_len = rqstp->rq_arg.len;
+		rp->c_key.k_csum = csum;
+	}
+	return rp;
+}
+
+static void nfsd_cacherep_free(struct nfsd_cacherep *rp)
+{
+	if (rp->c_type == RC_REPLBUFF)
+		kfree(rp->c_replvec.iov_base);
+	kmem_cache_free(drc_slab, rp);
+}
+
+static unsigned long
+nfsd_cacherep_dispose(struct list_head *dispose)
+{
+	struct nfsd_cacherep *rp;
+	unsigned long freed = 0;
+
+	while (!list_empty(dispose)) {
+		rp = list_first_entry(dispose, struct nfsd_cacherep, c_lru);
+		list_del(&rp->c_lru);
+		nfsd_cacherep_free(rp);
+		freed++;
+	}
+	return freed;
+}
+
+static void
+nfsd_cacherep_unlink_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+			    struct nfsd_cacherep *rp)
+{
+	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base)
+		nfsd_stats_drc_mem_usage_sub(nn, rp->c_replvec.iov_len);
+	if (rp->c_state != RC_UNUSED) {
+		rb_erase(&rp->c_node, &b->rb_head);
+		list_del(&rp->c_lru);
+		atomic_dec(&nn->num_drc_entries);
+		nfsd_stats_drc_mem_usage_sub(nn, sizeof(*rp));
+	}
+}
+
+static void
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp,
+				struct nfsd_net *nn)
+{
+	nfsd_cacherep_unlink_locked(nn, b, rp);
+	nfsd_cacherep_free(rp);
+}
+
+static void
+nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp,
+			struct nfsd_net *nn)
+{
+	spin_lock(&b->cache_lock);
+	nfsd_cacherep_unlink_locked(nn, b, rp);
+	spin_unlock(&b->cache_lock);
+	nfsd_cacherep_free(rp);
+}
+
+int nfsd_drc_slab_create(void)
+{
+	drc_slab = KMEM_CACHE(nfsd_cacherep, 0);
+	return drc_slab ? 0: -ENOMEM;
+}
+
+void nfsd_drc_slab_free(void)
+{
+	kmem_cache_destroy(drc_slab);
+}
+
+int nfsd_reply_cache_init(struct nfsd_net *nn)
+{
+	unsigned int hashsize;
+	unsigned int i;
+
+	nn->max_drc_entries = nfsd_cache_size_limit();
+	atomic_set(&nn->num_drc_entries, 0);
+	hashsize = nfsd_hashsize(nn->max_drc_entries);
+	nn->maskbits = ilog2(hashsize);
+
+	nn->drc_hashtbl = kvzalloc(array_size(hashsize,
+				sizeof(*nn->drc_hashtbl)), GFP_KERNEL);
+	if (!nn->drc_hashtbl)
+		return -ENOMEM;
+
+	nn->nfsd_reply_cache_shrinker = shrinker_alloc(0, "nfsd-reply:%s",
+						       nn->nfsd_name);
+	if (!nn->nfsd_reply_cache_shrinker)
+		goto out_shrinker;
+
+	nn->nfsd_reply_cache_shrinker->scan_objects = nfsd_reply_cache_scan;
+	nn->nfsd_reply_cache_shrinker->count_objects = nfsd_reply_cache_count;
+	nn->nfsd_reply_cache_shrinker->seeks = 1;
+	nn->nfsd_reply_cache_shrinker->private_data = nn;
+
+	for (i = 0; i < hashsize; i++) {
+		INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head);
+		spin_lock_init(&nn->drc_hashtbl[i].cache_lock);
+	}
+	nn->drc_hashsize = hashsize;
+
+	shrinker_register(nn->nfsd_reply_cache_shrinker);
+
+	return 0;
+out_shrinker:
+	kvfree(nn->drc_hashtbl);
+	printk(KERN_ERR "nfsd: failed to allocate reply cache\n");
+	return -ENOMEM;
+}
+
+void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
+{
+	struct nfsd_cacherep *rp;
+	unsigned int i;
+
+	shrinker_free(nn->nfsd_reply_cache_shrinker);
+
+	for (i = 0; i < nn->drc_hashsize; i++) {
+		struct list_head *head = &nn->drc_hashtbl[i].lru_head;
+		while (!list_empty(head)) {
+			rp = list_first_entry(head, struct nfsd_cacherep, c_lru);
+			nfsd_reply_cache_free_locked(&nn->drc_hashtbl[i],
+									rp, nn);
+		}
+	}
+
+	kvfree(nn->drc_hashtbl);
+	nn->drc_hashtbl = NULL;
+	nn->drc_hashsize = 0;
+
+}
+
+static void
+lru_put_end(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp)
+{
+	rp->c_timestamp = jiffies;
+	list_move_tail(&rp->c_lru, &b->lru_head);
+}
+
+static noinline struct nfsd_drc_bucket *
+nfsd_cache_bucket_find(__be32 xid, struct nfsd_net *nn)
+{
+	unsigned int hash = hash_32((__force u32)xid, nn->maskbits);
+
+	return &nn->drc_hashtbl[hash];
+}
+
+/*
+ * Remove and return no more than @max expired entries in bucket @b.
+ * If @max is zero, do not limit the number of removed entries.
+ */
+static void
+nfsd_prune_bucket_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+			 unsigned int max, struct list_head *dispose)
+{
+	unsigned long expiry = jiffies - RC_EXPIRE;
+	struct nfsd_cacherep *rp, *tmp;
+	unsigned int freed = 0;
+
+	lockdep_assert_held(&b->cache_lock);
+
+	/* The bucket LRU is ordered oldest-first. */
+	list_for_each_entry_safe(rp, tmp, &b->lru_head, c_lru) {
+		if (atomic_read(&nn->num_drc_entries) <= nn->max_drc_entries &&
+		    time_before(expiry, rp->c_timestamp))
+			break;
+
+		nfsd_cacherep_unlink_locked(nn, b, rp);
+		list_add(&rp->c_lru, dispose);
+
+		if (max && ++freed >= max)
+			break;
+	}
+}
+
+/**
+ * nfsd_reply_cache_count - count_objects method for the DRC shrinker
+ * @shrink: our registered shrinker context
+ * @sc: garbage collection parameters
+ *
+ * Returns the total number of entries in the duplicate reply cache. To
+ * keep things simple and quick, this is not the number of expired entries
+ * in the cache (ie, the number that would be removed by a call to
+ * nfsd_reply_cache_scan).
+ */
+static unsigned long
+nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct nfsd_net *nn = shrink->private_data;
+
+	return atomic_read(&nn->num_drc_entries);
+}
+
+/**
+ * nfsd_reply_cache_scan - scan_objects method for the DRC shrinker
+ * @shrink: our registered shrinker context
+ * @sc: garbage collection parameters
+ *
+ * Free expired entries on each bucket's LRU list until we've released
+ * nr_to_scan freed objects. Nothing will be released if the cache
+ * has not exceeded it's max_drc_entries limit.
+ *
+ * Returns the number of entries released by this call.
+ */
+static unsigned long
+nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct nfsd_net *nn = shrink->private_data;
+	unsigned long freed = 0;
+	LIST_HEAD(dispose);
+	unsigned int i;
+
+	for (i = 0; i < nn->drc_hashsize; i++) {
+		struct nfsd_drc_bucket *b = &nn->drc_hashtbl[i];
+
+		if (list_empty(&b->lru_head))
+			continue;
+
+		spin_lock(&b->cache_lock);
+		nfsd_prune_bucket_locked(nn, b, 0, &dispose);
+		spin_unlock(&b->cache_lock);
+
+		freed += nfsd_cacherep_dispose(&dispose);
+		if (freed > sc->nr_to_scan)
+			break;
+	}
+	return freed;
+}
+
+/**
+ * nfsd_cache_csum - Checksum incoming NFS Call arguments
+ * @buf: buffer containing a whole RPC Call message
+ * @start: starting byte of the NFS Call header
+ * @remaining: size of the NFS Call header, in bytes
+ *
+ * Compute a weak checksum of the leading bytes of an NFS procedure
+ * call header to help verify that a retransmitted Call matches an
+ * entry in the duplicate reply cache.
+ *
+ * To avoid assumptions about how the RPC message is laid out in
+ * @buf and what else it might contain (eg, a GSS MIC suffix), the
+ * caller passes us the exact location and length of the NFS Call
+ * header.
+ *
+ * Returns a 32-bit checksum value, as defined in RFC 793.
+ */
+static __wsum nfsd_cache_csum(struct xdr_buf *buf, unsigned int start,
+			      unsigned int remaining)
+{
+	unsigned int base, len;
+	struct xdr_buf subbuf;
+	__wsum csum = 0;
+	void *p;
+	int idx;
+
+	if (remaining > RC_CSUMLEN)
+		remaining = RC_CSUMLEN;
+	if (xdr_buf_subsegment(buf, &subbuf, start, remaining))
+		return csum;
+
+	/* rq_arg.head first */
+	if (subbuf.head[0].iov_len) {
+		len = min_t(unsigned int, subbuf.head[0].iov_len, remaining);
+		csum = csum_partial(subbuf.head[0].iov_base, len, csum);
+		remaining -= len;
+	}
+
+	/* Continue into page array */
+	idx = subbuf.page_base / PAGE_SIZE;
+	base = subbuf.page_base & ~PAGE_MASK;
+	while (remaining) {
+		p = page_address(subbuf.pages[idx]) + base;
+		len = min_t(unsigned int, PAGE_SIZE - base, remaining);
+		csum = csum_partial(p, len, csum);
+		remaining -= len;
+		base = 0;
+		++idx;
+	}
+	return csum;
+}
+
+static int
+nfsd_cache_key_cmp(const struct nfsd_cacherep *key,
+		   const struct nfsd_cacherep *rp, struct nfsd_net *nn)
+{
+	if (key->c_key.k_xid == rp->c_key.k_xid &&
+	    key->c_key.k_csum != rp->c_key.k_csum) {
+		nfsd_stats_payload_misses_inc(nn);
+		trace_nfsd_drc_mismatch(nn, key, rp);
+	}
+
+	return memcmp(&key->c_key, &rp->c_key, sizeof(key->c_key));
+}
+
+/*
+ * Search the request hash for an entry that matches the given rqstp.
+ * Must be called with cache_lock held. Returns the found entry or
+ * inserts an empty key on failure.
+ */
+static struct nfsd_cacherep *
+nfsd_cache_insert(struct nfsd_drc_bucket *b, struct nfsd_cacherep *key,
+			struct nfsd_net *nn)
+{
+	struct nfsd_cacherep	*rp, *ret = key;
+	struct rb_node		**p = &b->rb_head.rb_node,
+				*parent = NULL;
+	unsigned int		entries = 0;
+	int cmp;
+
+	while (*p != NULL) {
+		++entries;
+		parent = *p;
+		rp = rb_entry(parent, struct nfsd_cacherep, c_node);
+
+		cmp = nfsd_cache_key_cmp(key, rp, nn);
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else {
+			ret = rp;
+			goto out;
+		}
+	}
+	rb_link_node(&key->c_node, parent, p);
+	rb_insert_color(&key->c_node, &b->rb_head);
+out:
+	/* tally hash chain length stats */
+	if (entries > nn->longest_chain) {
+		nn->longest_chain = entries;
+		nn->longest_chain_cachesize = atomic_read(&nn->num_drc_entries);
+	} else if (entries == nn->longest_chain) {
+		/* prefer to keep the smallest cachesize possible here */
+		nn->longest_chain_cachesize = min_t(unsigned int,
+				nn->longest_chain_cachesize,
+				atomic_read(&nn->num_drc_entries));
+	}
+	return ret;
+}
+
+/**
+ * nfsd_cache_lookup - Find an entry in the duplicate reply cache
+ * @rqstp: Incoming Call to find
+ * @start: starting byte in @rqstp->rq_arg of the NFS Call header
+ * @len: size of the NFS Call header, in bytes
+ * @cacherep: OUT: DRC entry for this request
+ *
+ * Try to find an entry matching the current call in the cache. When none
+ * is found, we try to grab the oldest expired entry off the LRU list. If
+ * a suitable one isn't there, then drop the cache_lock and allocate a
+ * new one, then search again in case one got inserted while this thread
+ * didn't hold the lock.
+ *
+ * Return values:
+ *   %RC_DOIT: Process the request normally
+ *   %RC_REPLY: Reply from cache
+ *   %RC_DROPIT: Do not process the request further
+ */
+int nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
+		      unsigned int len, struct nfsd_cacherep **cacherep)
+{
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfsd_thread_local_info *ntli = rqstp->rq_private;
+	struct nfsd_cacherep	*rp, *found;
+	__wsum			csum;
+	struct nfsd_drc_bucket	*b;
+	int type = ntli->ntli_cachetype;
+	LIST_HEAD(dispose);
+	int rtn = RC_DOIT;
+
+	if (type == RC_NOCACHE) {
+		nfsd_stats_rc_nocache_inc(nn);
+		goto out;
+	}
+
+	csum = nfsd_cache_csum(&rqstp->rq_arg, start, len);
+
+	/*
+	 * Since the common case is a cache miss followed by an insert,
+	 * preallocate an entry.
+	 */
+	rp = nfsd_cacherep_alloc(rqstp, csum, nn);
+	if (!rp)
+		goto out;
+
+	b = nfsd_cache_bucket_find(rqstp->rq_xid, nn);
+	spin_lock(&b->cache_lock);
+	found = nfsd_cache_insert(b, rp, nn);
+	if (found != rp)
+		goto found_entry;
+	*cacherep = rp;
+	rp->c_state = RC_INPROG;
+	nfsd_prune_bucket_locked(nn, b, 3, &dispose);
+	spin_unlock(&b->cache_lock);
+
+	nfsd_cacherep_dispose(&dispose);
+
+	nfsd_stats_rc_misses_inc(nn);
+	atomic_inc(&nn->num_drc_entries);
+	nfsd_stats_drc_mem_usage_add(nn, sizeof(*rp));
+	goto out;
+
+found_entry:
+	/* We found a matching entry which is either in progress or done. */
+	nfsd_reply_cache_free_locked(NULL, rp, nn);
+	nfsd_stats_rc_hits_inc(nn);
+	rtn = RC_DROPIT;
+	rp = found;
+
+	/* Request being processed */
+	if (rp->c_state == RC_INPROG)
+		goto out_trace;
+
+	/* From the hall of fame of impractical attacks:
+	 * Is this a user who tries to snoop on the cache? */
+	rtn = RC_DOIT;
+	if (!test_bit(RQ_SECURE, &rqstp->rq_flags) && rp->c_secure)
+		goto out_trace;
+
+	/* Compose RPC reply header */
+	switch (rp->c_type) {
+	case RC_NOCACHE:
+		break;
+	case RC_REPLSTAT:
+		xdr_stream_encode_be32(&rqstp->rq_res_stream, rp->c_replstat);
+		rtn = RC_REPLY;
+		break;
+	case RC_REPLBUFF:
+		if (!nfsd_cache_append(rqstp, &rp->c_replvec))
+			goto out_unlock; /* should not happen */
+		rtn = RC_REPLY;
+		break;
+	default:
+		WARN_ONCE(1, "nfsd: bad repcache type %d\n", rp->c_type);
+	}
+
+out_trace:
+	trace_nfsd_drc_found(nn, rqstp, rtn);
+out_unlock:
+	spin_unlock(&b->cache_lock);
+out:
+	return rtn;
+}
+
+/**
+ * nfsd_cache_update - Update an entry in the duplicate reply cache.
+ * @rqstp: svc_rqst with a finished Reply
+ * @rp: IN: DRC entry for this request
+ * @cachetype: which cache to update
+ * @statp: pointer to Reply's NFS status code, or NULL
+ *
+ * This is called from nfsd_dispatch when the procedure has been
+ * executed and the complete reply is in rqstp->rq_res.
+ *
+ * We're copying around data here rather than swapping buffers because
+ * the toplevel loop requires max-sized buffers, which would be a waste
+ * of memory for a cache with a max reply size of 100 bytes (diropokres).
+ *
+ * If we should start to use different types of cache entries tailored
+ * specifically for attrstat and fh's, we may save even more space.
+ *
+ * Also note that a cachetype of RC_NOCACHE can legally be passed when
+ * nfsd failed to encode a reply that otherwise would have been cached.
+ * In this case, nfsd_cache_update is called with statp == NULL.
+ */
+void nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
+		       int cachetype, __be32 *statp)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct kvec	*resv = &rqstp->rq_res.head[0], *cachv;
+	struct nfsd_drc_bucket *b;
+	int		len;
+	size_t		bufsize = 0;
+
+	if (!rp)
+		return;
+
+	b = nfsd_cache_bucket_find(rp->c_key.k_xid, nn);
+
+	len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
+	len >>= 2;
+
+	/* Don't cache excessive amounts of data and XDR failures */
+	if (!statp || len > (256 >> 2)) {
+		nfsd_reply_cache_free(b, rp, nn);
+		return;
+	}
+
+	switch (cachetype) {
+	case RC_REPLSTAT:
+		if (len != 1)
+			printk("nfsd: RC_REPLSTAT/reply len %d!\n",len);
+		rp->c_replstat = *statp;
+		break;
+	case RC_REPLBUFF:
+		cachv = &rp->c_replvec;
+		bufsize = len << 2;
+		cachv->iov_base = kmalloc(bufsize, GFP_KERNEL);
+		if (!cachv->iov_base) {
+			nfsd_reply_cache_free(b, rp, nn);
+			return;
+		}
+		cachv->iov_len = bufsize;
+		memcpy(cachv->iov_base, statp, bufsize);
+		break;
+	case RC_NOCACHE:
+		nfsd_reply_cache_free(b, rp, nn);
+		return;
+	}
+	spin_lock(&b->cache_lock);
+	nfsd_stats_drc_mem_usage_add(nn, bufsize);
+	lru_put_end(b, rp);
+	rp->c_secure = test_bit(RQ_SECURE, &rqstp->rq_flags);
+	rp->c_type = cachetype;
+	rp->c_state = RC_DONE;
+	spin_unlock(&b->cache_lock);
+	return;
+}
+
+static int
+nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(&rqstp->rq_res_stream, data->iov_len);
+	if (unlikely(!p))
+		return false;
+	memcpy(p, data->iov_base, data->iov_len);
+	xdr_commit_encode(&rqstp->rq_res_stream);
+	return true;
+}
+
+/*
+ * Note that fields may be added, removed or reordered in the future. Programs
+ * scraping this file for info should test the labels to ensure they're
+ * getting the correct field.
+ */
+int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
+{
+	struct nfsd_net *nn = net_generic(file_inode(m->file)->i_sb->s_fs_info,
+					  nfsd_net_id);
+
+	seq_printf(m, "max entries:           %u\n", nn->max_drc_entries);
+	seq_printf(m, "num entries:           %u\n",
+		   atomic_read(&nn->num_drc_entries));
+	seq_printf(m, "hash buckets:          %u\n", 1 << nn->maskbits);
+	seq_printf(m, "mem usage:             %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_DRC_MEM_USAGE]));
+	seq_printf(m, "cache hits:            %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_HITS]));
+	seq_printf(m, "cache misses:          %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_MISSES]));
+	seq_printf(m, "not cached:            %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_NOCACHE]));
+	seq_printf(m, "payload misses:        %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_PAYLOAD_MISSES]));
+	seq_printf(m, "longest chain len:     %u\n", nn->longest_chain);
+	seq_printf(m, "cachesize at longest:  %u\n", nn->longest_chain_cachesize);
+	return 0;
+}
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
new file mode 100644
index 000000000..5abb2d427
--- /dev/null
+++ b/fs/nfsd/nfsctl.c
@@ -0,0 +1,2942 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Syscall interface to knfsd.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/ctype.h>
+#include <linux/fs_context.h>
+
+#include <linux/sunrpc/cache.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/lockd/bind.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/module.h>
+#include <linux/fsnotify.h>
+#include <linux/nfslocalio.h>
+
+#include "idmap.h"
+#include "nfsd.h"
+#include "netns.h"
+#include "stats.h"
+#include "cache.h"
+#include "state.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "trace.h"
+#include "netlink.h"
+
+/*
+ *	We have a single directory with several nodes in it.
+ */
+enum {
+	NFSD_Root = 1,
+	NFSD_List,
+	NFSD_Export_Stats,
+	NFSD_Export_features,
+	NFSD_Fh,
+	NFSD_FO_UnlockIP,
+	NFSD_FO_UnlockFS,
+	NFSD_Threads,
+	NFSD_Pool_Threads,
+	NFSD_Pool_Stats,
+	NFSD_Reply_Cache_Stats,
+	NFSD_Versions,
+	NFSD_Ports,
+	NFSD_MaxBlkSize,
+	NFSD_Filecache,
+	NFSD_Leasetime,
+	NFSD_Gracetime,
+	NFSD_RecoveryDir,
+	NFSD_V4EndGrace,
+	NFSD_MaxReserved
+};
+
+/*
+ * write() for these nodes.
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size);
+static ssize_t write_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_versions(struct file *file, char *buf, size_t size);
+static ssize_t write_ports(struct file *file, char *buf, size_t size);
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
+#ifdef CONFIG_NFSD_V4
+static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
+#endif
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size);
+#endif
+
+static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
+	[NFSD_Fh] = write_filehandle,
+	[NFSD_FO_UnlockIP] = write_unlock_ip,
+	[NFSD_FO_UnlockFS] = write_unlock_fs,
+	[NFSD_Threads] = write_threads,
+	[NFSD_Pool_Threads] = write_pool_threads,
+	[NFSD_Versions] = write_versions,
+	[NFSD_Ports] = write_ports,
+	[NFSD_MaxBlkSize] = write_maxblksize,
+#ifdef CONFIG_NFSD_V4
+	[NFSD_Leasetime] = write_leasetime,
+	[NFSD_Gracetime] = write_gracetime,
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+	[NFSD_RecoveryDir] = write_recoverydir,
+#endif
+	[NFSD_V4EndGrace] = write_v4_end_grace,
+#endif
+};
+
+static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
+{
+	ino_t ino =  file_inode(file)->i_ino;
+	char *data;
+	ssize_t rv;
+
+	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
+		return -EINVAL;
+
+	data = simple_transaction_get(file, buf, size);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	rv = write_op[ino](file, data, size);
+	if (rv < 0)
+		return rv;
+
+	simple_transaction_set(file, rv);
+	return size;
+}
+
+static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+	if (! file->private_data) {
+		/* An attempt to read a transaction file without writing
+		 * causes a 0-byte write so that the file can return
+		 * state information
+		 */
+		ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
+		if (rv < 0)
+			return rv;
+	}
+	return simple_transaction_read(file, buf, size, pos);
+}
+
+static const struct file_operations transaction_ops = {
+	.write		= nfsctl_transaction_write,
+	.read		= nfsctl_transaction_read,
+	.release	= simple_transaction_release,
+	.llseek		= default_llseek,
+};
+
+static int exports_net_open(struct net *net, struct file *file)
+{
+	int err;
+	struct seq_file *seq;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	err = seq_open(file, &nfs_exports_op);
+	if (err)
+		return err;
+
+	seq = file->private_data;
+	seq->private = nn->svc_export_cache;
+	get_net(net);
+	return 0;
+}
+
+static int exports_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct cache_detail *cd = seq->private;
+
+	put_net(cd->net);
+	return seq_release(inode, file);
+}
+
+static int exports_nfsd_open(struct inode *inode, struct file *file)
+{
+	return exports_net_open(inode->i_sb->s_fs_info, file);
+}
+
+static const struct file_operations exports_nfsd_operations = {
+	.open		= exports_nfsd_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= exports_release,
+};
+
+static int export_features_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "0x%x 0x%x\n", NFSEXP_ALLFLAGS, NFSEXP_SECINFO_FLAGS);
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(export_features);
+
+static int nfsd_pool_stats_open(struct inode *inode, struct file *file)
+{
+	struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
+
+	return svc_pool_stats_open(&nn->nfsd_info, file);
+}
+
+static const struct file_operations pool_stats_operations = {
+	.open		= nfsd_pool_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+DEFINE_SHOW_ATTRIBUTE(nfsd_reply_cache_stats);
+
+DEFINE_SHOW_ATTRIBUTE(nfsd_file_cache_stats);
+
+/*----------------------------------------------------------------------------*/
+/*
+ * payload - write methods
+ */
+
+static inline struct net *netns(struct file *file)
+{
+	return file_inode(file)->i_sb->s_fs_info;
+}
+
+/*
+ * write_unlock_ip - Release all locks used by a client
+ *
+ * Experimental.
+ *
+ * Input:
+ *			buf:	'\n'-terminated C string containing a
+ *				presentation format IP address
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	returns zero if all specified locks were released;
+ *			returns one if one or more locks were not released
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
+{
+	struct sockaddr_storage address;
+	struct sockaddr *sap = (struct sockaddr *)&address;
+	size_t salen = sizeof(address);
+	char *fo_path;
+	struct net *net = netns(file);
+
+	/* sanity check */
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+
+	fo_path = buf;
+	if (qword_get(&buf, fo_path, size) < 0)
+		return -EINVAL;
+
+	if (rpc_pton(net, fo_path, size, sap, salen) == 0)
+		return -EINVAL;
+
+	trace_nfsd_ctl_unlock_ip(net, sap, svc_addr_len(sap));
+	return nlmsvc_unlock_all_by_ip(sap);
+}
+
+/*
+ * write_unlock_fs - Release all locks on a local file system
+ *
+ * Experimental.
+ *
+ * Input:
+ *			buf:	'\n'-terminated C string containing the
+ *				absolute pathname of a local file system
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	returns zero if all specified locks were released;
+ *			returns one if one or more locks were not released
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
+{
+	struct path path;
+	char *fo_path;
+	int error;
+	struct nfsd_net *nn;
+
+	/* sanity check */
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+
+	fo_path = buf;
+	if (qword_get(&buf, fo_path, size) < 0)
+		return -EINVAL;
+	trace_nfsd_ctl_unlock_fs(netns(file), fo_path);
+	error = kern_path(fo_path, 0, &path);
+	if (error)
+		return error;
+
+	/*
+	 * XXX: Needs better sanity checking.  Otherwise we could end up
+	 * releasing locks on the wrong file system.
+	 *
+	 * For example:
+	 * 1.  Does the path refer to a directory?
+	 * 2.  Is that directory a mount point, or
+	 * 3.  Is that directory the root of an exported file system?
+	 */
+	error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
+	mutex_lock(&nfsd_mutex);
+	nn = net_generic(netns(file), nfsd_net_id);
+	if (test_bit(NFSD_NET_UP, &nn->flags)) {
+		nfsd4_cancel_copy_by_sb(netns(file), path.dentry->d_sb);
+		nfsd4_revoke_states(nn, path.dentry->d_sb);
+	} else {
+		error = -EINVAL;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	path_put(&path);
+	return error;
+}
+
+/*
+ * write_filehandle - Get a variable-length NFS file handle by path
+ *
+ * On input, the buffer contains a '\n'-terminated C string comprised of
+ * three alphanumeric words separated by whitespace.  The string may
+ * contain escape sequences.
+ *
+ * Input:
+ *			buf:
+ *				domain:		client domain name
+ *				path:		export pathname
+ *				maxsize:	numeric maximum size of
+ *						@buf
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing a ASCII hex text version
+ *			of the NFS file handle;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
+{
+	char *dname, *path;
+	int maxsize;
+	char *mesg = buf;
+	int len;
+	struct auth_domain *dom;
+	struct knfsd_fh fh;
+
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+	buf[size-1] = 0;
+
+	dname = mesg;
+	len = qword_get(&mesg, dname, size);
+	if (len <= 0)
+		return -EINVAL;
+
+	path = dname+len+1;
+	len = qword_get(&mesg, path, size);
+	if (len <= 0)
+		return -EINVAL;
+
+	len = get_int(&mesg, &maxsize);
+	if (len)
+		return len;
+
+	if (maxsize < NFS_FHSIZE)
+		return -EINVAL;
+	maxsize = min(maxsize, NFS3_FHSIZE);
+
+	if (qword_get(&mesg, mesg, size) > 0)
+		return -EINVAL;
+
+	trace_nfsd_ctl_filehandle(netns(file), dname, path, maxsize);
+
+	/* we have all the words, they are in buf.. */
+	dom = unix_domain_find(dname);
+	if (!dom)
+		return -ENOMEM;
+
+	len = exp_rootfh(netns(file), dom, path, &fh, maxsize);
+	auth_domain_put(dom);
+	if (len)
+		return len;
+
+	mesg = buf;
+	len = SIMPLE_TRANSACTION_LIMIT;
+	qword_addhex(&mesg, &len, fh.fh_raw, fh.fh_size);
+	mesg[-1] = '\n';
+	return mesg - buf;
+}
+
+/*
+ * write_threads - Start NFSD, or report the configured number of threads
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string numeric value representing the configured
+ *			number of NFSD threads;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing the
+ *					number of NFSD threads to start
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	NFS service is started;
+ *			passed-in buffer filled with '\n'-terminated C
+ *			string numeric value representing the configured
+ *			number of NFSD threads;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_threads(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	int rv;
+	struct net *net = netns(file);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (size > 0) {
+		int newthreads;
+		rv = get_int(&mesg, &newthreads);
+		if (rv)
+			return rv;
+		if (newthreads < 0)
+			return -EINVAL;
+		trace_nfsd_ctl_threads(net, newthreads);
+		mutex_lock(&nfsd_mutex);
+		if (newthreads > 0 || nn->nfsd_serv != NULL)
+			rv = nfsd_svc(1, &newthreads, net, file->f_cred, NULL);
+		else
+			rv = 0;
+		mutex_unlock(&nfsd_mutex);
+		if (rv < 0)
+			return rv;
+	} else
+		rv = nfsd_nrthreads(net);
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n", rv);
+}
+
+/*
+ * write_pool_threads - Set or report the configured number of threads per pool
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing whitespace-
+ *					separated unsigned integer values
+ *					representing the number of NFSD
+ *					threads to start in each pool
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing integer values representing the
+ *			configured number of NFSD threads in each pool;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+{
+	/* if size > 0, look for an array of number of threads per node
+	 * and apply them  then write out number of threads per node as reply
+	 */
+	char *mesg = buf;
+	int i;
+	int rv;
+	int len;
+	int npools;
+	int *nthreads;
+	struct net *net = netns(file);
+
+	mutex_lock(&nfsd_mutex);
+	npools = nfsd_nrpools(net);
+	if (npools == 0) {
+		/*
+		 * NFS is shut down.  The admin can start it by
+		 * writing to the threads file but NOT the pool_threads
+		 * file, sorry.  Report zero threads.
+		 */
+		mutex_unlock(&nfsd_mutex);
+		strcpy(buf, "0\n");
+		return strlen(buf);
+	}
+
+	nthreads = kzalloc_objs(int, npools);
+	rv = -ENOMEM;
+	if (nthreads == NULL)
+		goto out_free;
+
+	if (size > 0) {
+		for (i = 0; i < npools; i++) {
+			rv = get_int(&mesg, &nthreads[i]);
+			if (rv == -ENOENT)
+				break;		/* fewer numbers than pools */
+			if (rv)
+				goto out_free;	/* syntax error */
+			rv = -EINVAL;
+			if (nthreads[i] < 0)
+				goto out_free;
+			trace_nfsd_ctl_pool_threads(net, i, nthreads[i]);
+		}
+
+		/*
+		 * There must always be a thread in pool 0; the admin
+		 * can't shut down NFS completely using pool_threads.
+		 */
+		if (nthreads[0] == 0)
+			nthreads[0] = 1;
+
+		rv = nfsd_set_nrthreads(i, nthreads, net);
+		if (rv)
+			goto out_free;
+	}
+
+	rv = nfsd_get_nrthreads(npools, nthreads, net);
+	if (rv)
+		goto out_free;
+
+	mesg = buf;
+	size = SIMPLE_TRANSACTION_LIMIT;
+	for (i = 0; i < npools && size > 0; i++) {
+		snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
+		len = strlen(mesg);
+		size -= len;
+		mesg += len;
+	}
+	rv = mesg - buf;
+out_free:
+	kfree(nthreads);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+static ssize_t
+nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
+		const char *sep, unsigned vers, int minor)
+{
+	const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
+	bool supported = !!nfsd_vers(nn, vers, NFSD_TEST);
+
+	if (vers == 4 && minor >= 0 &&
+	    !nfsd_minorversion(nn, minor, NFSD_TEST))
+		supported = false;
+	if (minor == 0 && supported)
+		/*
+		 * special case for backward compatability.
+		 * +4.0 is never reported, it is implied by
+		 * +4, unless -4.0 is present.
+		 */
+		return 0;
+	return snprintf(buf, remaining, format, sep,
+			supported ? '+' : '-', vers, minor);
+}
+
+static ssize_t __write_versions(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	char *vers, *minorp, sign;
+	int len, num, remaining;
+	ssize_t tlen = 0;
+	char *sep;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size > 0) {
+		if (nn->nfsd_serv)
+			/* Cannot change versions without updating
+			 * nn->nfsd_serv->sv_xdrsize, and reallocing
+			 * rq_argp and rq_resp
+			 */
+			return -EBUSY;
+		if (buf[size-1] != '\n')
+			return -EINVAL;
+		buf[size-1] = 0;
+		trace_nfsd_ctl_version(netns(file), buf);
+
+		vers = mesg;
+		len = qword_get(&mesg, vers, size);
+		if (len <= 0) return -EINVAL;
+		do {
+			enum vers_op cmd;
+			unsigned minor;
+			sign = *vers;
+			if (sign == '+' || sign == '-')
+				num = simple_strtol((vers+1), &minorp, 0);
+			else
+				num = simple_strtol(vers, &minorp, 0);
+			if (*minorp == '.') {
+				if (num != 4)
+					return -EINVAL;
+				if (kstrtouint(minorp+1, 0, &minor) < 0)
+					return -EINVAL;
+			}
+
+			cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
+			switch(num) {
+#ifdef CONFIG_NFSD_V2
+			case 2:
+#endif
+			case 3:
+				nfsd_vers(nn, num, cmd);
+				break;
+			case 4:
+				if (*minorp == '.') {
+					if (nfsd_minorversion(nn, minor, cmd) < 0)
+						return -EINVAL;
+				} else if ((cmd == NFSD_SET) != nfsd_vers(nn, num, NFSD_TEST)) {
+					/*
+					 * Either we have +4 and no minors are enabled,
+					 * or we have -4 and at least one minor is enabled.
+					 * In either case, propagate 'cmd' to all minors.
+					 */
+					minor = 0;
+					while (nfsd_minorversion(nn, minor, cmd) >= 0)
+						minor++;
+				}
+				break;
+			default:
+				/* Ignore requests to disable non-existent versions */
+				if (cmd == NFSD_SET)
+					return -EINVAL;
+			}
+			vers += len + 1;
+		} while ((len = qword_get(&mesg, vers, size)) > 0);
+		/* If all get turned off, turn them back on, as
+		 * having no versions is BAD
+		 */
+		nfsd_reset_versions(nn);
+	}
+
+	/* Now write current state into reply buffer */
+	sep = "";
+	remaining = SIMPLE_TRANSACTION_LIMIT;
+	for (num=2 ; num <= 4 ; num++) {
+		int minor;
+		if (!nfsd_vers(nn, num, NFSD_AVAIL))
+			continue;
+
+		minor = -1;
+		do {
+			len = nfsd_print_version_support(nn, buf, remaining,
+					sep, num, minor);
+			if (len >= remaining)
+				goto out;
+			remaining -= len;
+			buf += len;
+			tlen += len;
+			minor++;
+			if (len)
+				sep = " ";
+		} while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
+	}
+out:
+	len = snprintf(buf, remaining, "\n");
+	if (len >= remaining)
+		return -EINVAL;
+	return tlen + len;
+}
+
+/*
+ * write_versions - Set or report the available NFS protocol versions
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing positive or negative integer
+ *			values representing the current status of each
+ *			protocol version;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing whitespace-
+ *					separated positive or negative
+ *					integer values representing NFS
+ *					protocol versions to enable ("+n")
+ *					or disable ("-n")
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	status of zero or more protocol versions has
+ *			been updated; passed-in buffer filled with
+ *			'\n'-terminated C string containing positive
+ *			or negative integer values representing the
+ *			current status of each protocol version;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_versions(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_versions(file, buf, size);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+/*
+ * Zero-length write.  Return a list of NFSD's current listener
+ * transports.
+ */
+static ssize_t __write_ports_names(char *buf, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->nfsd_serv == NULL)
+		return 0;
+	return svc_xprt_names(nn->nfsd_serv, buf, SIMPLE_TRANSACTION_LIMIT);
+}
+
+/*
+ * A single 'fd' number was written, in which case it must be for
+ * a socket of a supported family/protocol, and we use it as an
+ * nfsd listener.
+ */
+static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred *cred)
+{
+	char *mesg = buf;
+	int fd, err;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	err = get_int(&mesg, &fd);
+	if (err != 0 || fd < 0)
+		return -EINVAL;
+	trace_nfsd_ctl_ports_addfd(net, fd);
+
+	err = nfsd_create_serv(net);
+	if (err != 0)
+		return err;
+
+	serv = nn->nfsd_serv;
+	err = svc_addsock(serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
+
+	if (!serv->sv_nrthreads && list_empty(&nn->nfsd_serv->sv_permsocks))
+		nfsd_destroy_serv(net);
+
+	return err;
+}
+
+/*
+ * A transport listener is added by writing its transport name and
+ * a port number.
+ */
+static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cred *cred)
+{
+	char transport[16];
+	struct svc_xprt *xprt;
+	int port, err;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	if (sscanf(buf, "%15s %5u", transport, &port) != 2)
+		return -EINVAL;
+
+	if (port < 1 || port > USHRT_MAX)
+		return -EINVAL;
+	trace_nfsd_ctl_ports_addxprt(net, transport, port);
+
+	err = nfsd_create_serv(net);
+	if (err != 0)
+		return err;
+
+	serv = nn->nfsd_serv;
+	err = svc_xprt_create(serv, transport, net,
+			      PF_INET, port, SVC_SOCK_ANONYMOUS, cred);
+	if (err < 0)
+		goto out_err;
+
+	err = svc_xprt_create(serv, transport, net,
+			      PF_INET6, port, SVC_SOCK_ANONYMOUS, cred);
+	if (err < 0 && err != -EAFNOSUPPORT)
+		goto out_close;
+
+	return 0;
+out_close:
+	xprt = svc_find_xprt(serv, transport, net, PF_INET, port);
+	if (xprt != NULL) {
+		svc_xprt_close(xprt);
+		svc_xprt_put(xprt);
+	}
+out_err:
+	if (!serv->sv_nrthreads && list_empty(&nn->nfsd_serv->sv_permsocks))
+		nfsd_destroy_serv(net);
+
+	return err;
+}
+
+static ssize_t __write_ports(struct file *file, char *buf, size_t size,
+			     struct net *net)
+{
+	if (size == 0)
+		return __write_ports_names(buf, net);
+
+	if (isdigit(buf[0]))
+		return __write_ports_addfd(buf, net, file->f_cred);
+
+	if (isalpha(buf[0]))
+		return __write_ports_addxprt(buf, net, file->f_cred);
+
+	return -EINVAL;
+}
+
+/*
+ * write_ports - Pass a socket file descriptor or transport name to listen on
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with a '\n'-terminated C
+ *			string containing a whitespace-separated list of
+ *			named NFSD listeners;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing a bound
+ *					but unconnected socket that is to be
+ *					used as an NFSD listener; listen(3)
+ *					must be called for a SOCK_STREAM
+ *					socket, otherwise it is ignored
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	NFS service is started;
+ *			passed-in buffer filled with a '\n'-terminated C
+ *			string containing a unique alphanumeric name of
+ *			the listener;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing a transport
+ *					name and an unsigned integer value
+ *					representing the port to listen on,
+ *					separated by whitespace
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	returns zero; NFS service is started
+ *	On error:	return code is a negative errno value
+ */
+static ssize_t write_ports(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_ports(file, buf, size, netns(file));
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+
+int nfsd_max_blksize;
+
+/*
+ * write_maxblksize - Set or report the current NFS blksize
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing the new
+ *					NFS blksize
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing numeric value of the current NFS blksize
+ *			setting;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size > 0) {
+		int bsize;
+		int rv = get_int(&mesg, &bsize);
+		if (rv)
+			return rv;
+		trace_nfsd_ctl_maxblksize(netns(file), bsize);
+
+		/* force bsize into allowed range and
+		 * required alignment.
+		 */
+		bsize = max_t(int, bsize, 1024);
+		bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
+		bsize &= ~(1024-1);
+		mutex_lock(&nfsd_mutex);
+		if (nn->nfsd_serv) {
+			mutex_unlock(&nfsd_mutex);
+			return -EBUSY;
+		}
+		nfsd_max_blksize = bsize;
+		mutex_unlock(&nfsd_mutex);
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
+							nfsd_max_blksize);
+}
+
+#ifdef CONFIG_NFSD_V4
+static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
+				  time64_t *time, struct nfsd_net *nn)
+{
+	struct dentry *dentry = file_dentry(file);
+	char *mesg = buf;
+	int rv, i;
+
+	if (size > 0) {
+		if (nn->nfsd_serv)
+			return -EBUSY;
+		rv = get_int(&mesg, &i);
+		if (rv)
+			return rv;
+		trace_nfsd_ctl_time(netns(file), dentry->d_name.name,
+				    dentry->d_name.len, i);
+
+		/*
+		 * Some sanity checking.  We don't have a reason for
+		 * these particular numbers, but problems with the
+		 * extremes are:
+		 *	- Too short: the briefest network outage may
+		 *	  cause clients to lose all their locks.  Also,
+		 *	  the frequent polling may be wasteful.
+		 *	- Too long: do you really want reboot recovery
+		 *	  to take more than an hour?  Or to make other
+		 *	  clients wait an hour before being able to
+		 *	  revoke a dead client's locks?
+		 */
+		if (i < 10 || i > 3600)
+			return -EINVAL;
+		*time = i;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%lld\n", *time);
+}
+
+static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
+				time64_t *time, struct nfsd_net *nn)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __nfsd4_write_time(file, buf, size, time, nn);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+/*
+ * write_leasetime - Set or report the current NFSv4 lease time
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing the new
+ *					NFSv4 lease expiry time
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing unsigned integer value of the
+ *			current lease expiry time;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+	return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
+}
+
+/*
+ * write_gracetime - Set or report current NFSv4 grace period time
+ *
+ * As above, but sets the time of the NFSv4 grace period.
+ *
+ * Note this should never be set to less than the *previous*
+ * lease-period time, but we don't try to enforce this.  (In the common
+ * case (a new boot), we don't know what the previous lease time was
+ * anyway.)
+ */
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+	return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
+}
+
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
+				   struct nfsd_net *nn)
+{
+	char *mesg = buf;
+	char *recdir;
+	int len, status;
+
+	if (size > 0) {
+		if (nn->nfsd_serv)
+			return -EBUSY;
+		if (size > PATH_MAX || buf[size-1] != '\n')
+			return -EINVAL;
+		buf[size-1] = 0;
+
+		recdir = mesg;
+		len = qword_get(&mesg, recdir, size);
+		if (len <= 0)
+			return -EINVAL;
+		trace_nfsd_ctl_recoverydir(netns(file), recdir);
+
+		status = nfs4_reset_recoverydir(recdir);
+		if (status)
+			return status;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%s\n",
+							nfs4_recoverydir());
+}
+
+/*
+ * write_recoverydir - Set or report the pathname of the recovery directory
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing the pathname
+ *					of the directory on a local file
+ *					system containing permanent NFSv4
+ *					recovery data
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing the current recovery pathname setting;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_recoverydir(file, buf, size, nn);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+#endif
+
+/*
+ * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * OR
+ *
+ * Input:
+ *			buf:		any value
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *			passed-in buffer filled with "Y" or "N" with a newline
+ *			and NULL-terminated C string. This indicates whether
+ *			the grace period has ended in the current net
+ *			namespace. Return code is the size in bytes of the
+ *			string. Writing a string that starts with 'Y', 'y', or
+ *			'1' to the file will end the grace period for nfsd's v4
+ *			lock manager.
+ */
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size > 0) {
+		switch(buf[0]) {
+		case 'Y':
+		case 'y':
+		case '1':
+			if (!nfsd4_force_end_grace(nn))
+				return -EBUSY;
+			trace_nfsd_end_grace(netns(file));
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
+			 test_bit(NFSD_NET_GRACE_ENDED, &nn->flags) ? 'Y' : 'N');
+}
+
+#endif
+
+/*----------------------------------------------------------------------------*/
+/*
+ *	populating the filesystem.
+ */
+
+static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
+{
+	struct inode *inode = new_inode(sb);
+	if (inode) {
+		/* Following advice from simple_fill_super documentation: */
+		inode->i_ino = iunique(sb, NFSD_MaxReserved);
+		inode->i_mode = mode;
+		simple_inode_init_ts(inode);
+	}
+	return inode;
+}
+
+static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *ncl, char *name)
+{
+	struct inode *dir = parent->d_inode;
+	struct dentry *dentry;
+	struct inode *inode;
+
+	inode = nfsd_get_inode(parent->d_sb, S_IFDIR | 0600);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(inode);
+		return dentry;
+	}
+	inode->i_fop = &simple_dir_operations;
+	inode->i_op = &simple_dir_inode_operations;
+	inc_nlink(inode);
+	if (ncl) {
+		inode->i_private = ncl;
+		kref_get(&ncl->cl_ref);
+	}
+	d_make_persistent(dentry, inode);
+	inc_nlink(dir);
+	fsnotify_mkdir(dir, dentry);
+	simple_done_creating(dentry);
+	return dentry;	// borrowed
+}
+
+#if IS_ENABLED(CONFIG_SUNRPC_GSS)
+/*
+ * @content is assumed to be a NUL-terminated string that lives
+ * longer than the symlink itself.
+ */
+static void _nfsd_symlink(struct dentry *parent, const char *name,
+			  const char *content)
+{
+	struct inode *dir = parent->d_inode;
+	struct inode *inode;
+	struct dentry *dentry;
+
+	inode = nfsd_get_inode(dir->i_sb, S_IFLNK | 0777);
+	if (!inode)
+		return;
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(inode);
+		return;
+	}
+
+	inode->i_op = &simple_symlink_inode_operations;
+	inode->i_link = (char *)content;
+	inode->i_size = strlen(content);
+
+	d_make_persistent(dentry, inode);
+	fsnotify_create(dir, dentry);
+	simple_done_creating(dentry);
+}
+#else
+static inline void _nfsd_symlink(struct dentry *parent, const char *name,
+				 const char *content)
+{
+}
+
+#endif
+
+static void clear_ncl(struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+	struct nfsdfs_client *ncl = inode->i_private;
+
+	spin_lock(&inode->i_lock);
+	inode->i_private = NULL;
+	spin_unlock(&inode->i_lock);
+	kref_put(&ncl->cl_ref, ncl->cl_release);
+}
+
+struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
+{
+	struct nfsdfs_client *nc;
+
+	spin_lock(&inode->i_lock);
+	nc = inode->i_private;
+	if (nc)
+		kref_get(&nc->cl_ref);
+	spin_unlock(&inode->i_lock);
+	return nc;
+}
+
+/* XXX: cut'n'paste from simple_fill_super; figure out if we could share
+ * code instead. */
+static int nfsdfs_create_files(struct dentry *root,
+				const struct tree_descr *files,
+				struct nfsdfs_client *ncl,
+				struct dentry **fdentries)
+{
+	struct inode *dir = d_inode(root);
+	struct dentry *dentry;
+
+	for (int i = 0; files->name && files->name[0]; i++, files++) {
+		struct inode *inode = nfsd_get_inode(root->d_sb,
+						     S_IFREG | files->mode);
+		if (!inode)
+			return -ENOMEM;
+		dentry = simple_start_creating(root, files->name);
+		if (IS_ERR(dentry)) {
+			iput(inode);
+			return PTR_ERR(dentry);
+		}
+		kref_get(&ncl->cl_ref);
+		inode->i_fop = files->ops;
+		inode->i_private = ncl;
+		d_make_persistent(dentry, inode);
+		fsnotify_create(dir, dentry);
+		if (fdentries)
+			fdentries[i] = dentry; // borrowed
+		simple_done_creating(dentry);
+	}
+	return 0;
+}
+
+/* on success, returns positive number unique to that client. */
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
+				 struct nfsdfs_client *ncl, u32 id,
+				 const struct tree_descr *files,
+				 struct dentry **fdentries)
+{
+	struct dentry *dentry;
+	char name[11];
+	int ret;
+
+	sprintf(name, "%u", id);
+
+	dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
+	if (IS_ERR(dentry)) /* XXX: tossing errors? */
+		return NULL;
+	ret = nfsdfs_create_files(dentry, files, ncl, fdentries);
+	if (ret) {
+		nfsd_client_rmdir(dentry);
+		return NULL;
+	}
+	return dentry;
+}
+
+/* Taken from __rpc_rmdir: */
+void nfsd_client_rmdir(struct dentry *dentry)
+{
+	simple_recursive_removal(dentry, clear_ncl);
+}
+
+static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+							nfsd_net_id);
+	struct dentry *dentry;
+	int ret;
+
+	static const struct tree_descr nfsd_files[] = {
+		[NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
+		/* Per-export io stats use same ops as exports file */
+		[NFSD_Export_Stats] = {"export_stats", &exports_nfsd_operations, S_IRUGO},
+		[NFSD_Export_features] = {"export_features",
+					&export_features_fops, S_IRUGO},
+		[NFSD_FO_UnlockIP] = {"unlock_ip",
+					&transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_FO_UnlockFS] = {"unlock_filesystem",
+					&transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
+		[NFSD_Reply_Cache_Stats] = {"reply_cache_stats",
+					&nfsd_reply_cache_stats_fops, S_IRUGO},
+		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO},
+#ifdef CONFIG_NFSD_V4
+		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
+#ifdef CONFIG_NFSD_LEGACY_CLIENT_TRACKING
+		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
+#endif
+		[NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
+#endif
+		/* last one */ {""}
+	};
+
+	ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
+	if (ret)
+		return ret;
+	_nfsd_symlink(sb->s_root, "supported_krb5_enctypes",
+		      "/proc/net/rpc/gss_krb5_enctypes");
+	dentry = nfsd_mkdir(sb->s_root, NULL, "clients");
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+	nn->nfsd_client_dir = dentry;
+	return 0;
+}
+
+static int nfsd_fs_get_tree(struct fs_context *fc)
+{
+	return get_tree_keyed(fc, nfsd_fill_super, get_net(fc->net_ns));
+}
+
+static void nfsd_fs_free_fc(struct fs_context *fc)
+{
+	if (fc->s_fs_info)
+		put_net(fc->s_fs_info);
+}
+
+static const struct fs_context_operations nfsd_fs_context_ops = {
+	.free		= nfsd_fs_free_fc,
+	.get_tree	= nfsd_fs_get_tree,
+};
+
+static int nfsd_init_fs_context(struct fs_context *fc)
+{
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
+	fc->ops = &nfsd_fs_context_ops;
+	return 0;
+}
+
+static void nfsd_umount(struct super_block *sb)
+{
+	struct net *net = sb->s_fs_info;
+
+	nfsd_shutdown_threads(net);
+
+	kill_anon_super(sb);
+	put_net(net);
+}
+
+static struct file_system_type nfsd_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "nfsd",
+	.init_fs_context = nfsd_init_fs_context,
+	.kill_sb	= nfsd_umount,
+};
+MODULE_ALIAS_FS("nfsd");
+
+#ifdef CONFIG_PROC_FS
+
+static int exports_proc_open(struct inode *inode, struct file *file)
+{
+	return exports_net_open(current->nsproxy->net_ns, file);
+}
+
+static const struct proc_ops exports_proc_ops = {
+	.proc_open	= exports_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= exports_release,
+};
+
+static int create_proc_exports_entry(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = proc_mkdir("fs/nfs", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry = proc_create("exports", 0, entry, &exports_proc_ops);
+	if (!entry) {
+		remove_proc_entry("fs/nfs", NULL);
+		return -ENOMEM;
+	}
+	return 0;
+}
+#else /* CONFIG_PROC_FS */
+static int create_proc_exports_entry(void)
+{
+	return 0;
+}
+#endif
+
+unsigned int nfsd_net_id;
+
+struct nfsd_genl_rqstp {
+	struct sockaddr_storage	rq_daddr;
+	struct sockaddr_storage	rq_saddr;
+	unsigned long		rq_flags;
+	ktime_t			rq_stime;
+	__be32			rq_xid;
+	u32			rq_vers;
+	u32			rq_prog;
+	u32			rq_proc;
+
+	/* NFSv4 compound */
+	u32			rq_opcnt;
+	u32			rq_opnum[16];
+};
+
+static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb,
+					    struct netlink_callback *cb,
+					    struct nfsd_genl_rqstp *genl_rqstp)
+{
+	void *hdr;
+	u32 i;
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &nfsd_nl_family, 0, NFSD_CMD_RPC_STATUS_GET);
+	if (!hdr)
+		return -ENOBUFS;
+
+	if (nla_put_be32(skb, NFSD_A_RPC_STATUS_XID, genl_rqstp->rq_xid) ||
+	    nla_put_u32(skb, NFSD_A_RPC_STATUS_FLAGS, genl_rqstp->rq_flags) ||
+	    nla_put_u32(skb, NFSD_A_RPC_STATUS_PROG, genl_rqstp->rq_prog) ||
+	    nla_put_u32(skb, NFSD_A_RPC_STATUS_PROC, genl_rqstp->rq_proc) ||
+	    nla_put_u8(skb, NFSD_A_RPC_STATUS_VERSION, genl_rqstp->rq_vers) ||
+	    nla_put_s64(skb, NFSD_A_RPC_STATUS_SERVICE_TIME,
+			ktime_to_us(genl_rqstp->rq_stime),
+			NFSD_A_RPC_STATUS_PAD))
+		goto out_cancel;
+
+	switch (genl_rqstp->rq_saddr.ss_family) {
+	case AF_INET: {
+		const struct sockaddr_in *s_in, *d_in;
+
+		s_in = (const struct sockaddr_in *)&genl_rqstp->rq_saddr;
+		d_in = (const struct sockaddr_in *)&genl_rqstp->rq_daddr;
+		if (nla_put_in_addr(skb, NFSD_A_RPC_STATUS_SADDR4,
+				    s_in->sin_addr.s_addr) ||
+		    nla_put_in_addr(skb, NFSD_A_RPC_STATUS_DADDR4,
+				    d_in->sin_addr.s_addr) ||
+		    nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
+				 s_in->sin_port) ||
+		    nla_put_be16(skb, NFSD_A_RPC_STATUS_DPORT,
+				 d_in->sin_port))
+			goto out_cancel;
+		break;
+	}
+	case AF_INET6: {
+		const struct sockaddr_in6 *s_in, *d_in;
+
+		s_in = (const struct sockaddr_in6 *)&genl_rqstp->rq_saddr;
+		d_in = (const struct sockaddr_in6 *)&genl_rqstp->rq_daddr;
+		if (nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_SADDR6,
+				     &s_in->sin6_addr) ||
+		    nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_DADDR6,
+				     &d_in->sin6_addr) ||
+		    nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
+				 s_in->sin6_port) ||
+		    nla_put_be16(skb, NFSD_A_RPC_STATUS_DPORT,
+				 d_in->sin6_port))
+			goto out_cancel;
+		break;
+	}
+	}
+
+	for (i = 0; i < genl_rqstp->rq_opcnt; i++)
+		if (nla_put_u32(skb, NFSD_A_RPC_STATUS_COMPOUND_OPS,
+				genl_rqstp->rq_opnum[i]))
+			goto out_cancel;
+
+	genlmsg_end(skb, hdr);
+	return 0;
+
+out_cancel:
+	genlmsg_cancel(skb, hdr);
+	return -ENOBUFS;
+}
+
+/**
+ * nfsd_nl_rpc_status_get_dumpit - Handle rpc_status_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
+				  struct netlink_callback *cb)
+{
+	int i, ret, rqstp_index = 0;
+	struct nfsd_net *nn;
+
+	mutex_lock(&nfsd_mutex);
+
+	nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	if (!nn->nfsd_serv) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	rcu_read_lock();
+
+	for (i = 0; i < svc_serv_nrpools(nn->nfsd_serv); i++) {
+		struct svc_rqst *rqstp;
+		long thread_skip = 0;
+
+		if (i < cb->args[0]) /* already consumed */
+			continue;
+
+		/*
+		 * The saved thread index only applies to the pool the dump
+		 * was resumed in. Subsequent pools must start from thread 0,
+		 * otherwise their first cb->args[1] threads are silently
+		 * skipped.
+		 */
+		if (i == cb->args[0])
+			thread_skip = cb->args[1];
+
+		rqstp_index = 0;
+		list_for_each_entry_rcu(rqstp,
+				&nn->nfsd_serv->sv_pools[i].sp_all_threads,
+				rq_all) {
+			struct nfsd_genl_rqstp genl_rqstp = {};
+			unsigned int status_counter;
+
+			if (rqstp_index++ < thread_skip) /* already consumed */
+				continue;
+			/*
+			 * Acquire rq_status_counter before parsing the rqst
+			 * fields. rq_status_counter is set to an odd value in
+			 * order to notify the consumers the rqstp fields are
+			 * meaningful.
+			 */
+			status_counter =
+				smp_load_acquire(&rqstp->rq_status_counter);
+			if (!(status_counter & 1))
+				continue;
+
+			genl_rqstp.rq_xid = rqstp->rq_xid;
+			genl_rqstp.rq_flags = rqstp->rq_flags;
+			genl_rqstp.rq_vers = rqstp->rq_vers;
+			genl_rqstp.rq_prog = rqstp->rq_prog;
+			genl_rqstp.rq_proc = rqstp->rq_proc;
+			genl_rqstp.rq_stime = rqstp->rq_stime;
+			genl_rqstp.rq_opcnt = 0;
+			memcpy(&genl_rqstp.rq_daddr, svc_daddr(rqstp),
+			       sizeof(struct sockaddr_storage));
+			memcpy(&genl_rqstp.rq_saddr, svc_addr(rqstp),
+			       sizeof(struct sockaddr_storage));
+
+#ifdef CONFIG_NFSD_V4
+			if (rqstp->rq_vers == NFS4_VERSION &&
+			    rqstp->rq_proc == NFSPROC4_COMPOUND) {
+				/* NFSv4 compound */
+				struct nfsd4_compoundargs *args;
+				int j;
+
+				args = rqstp->rq_argp;
+				genl_rqstp.rq_opcnt = min_t(u32, args->opcnt,
+							    ARRAY_SIZE(genl_rqstp.rq_opnum));
+				for (j = 0; j < genl_rqstp.rq_opcnt; j++)
+					genl_rqstp.rq_opnum[j] =
+						args->ops[j].opnum;
+			}
+#endif /* CONFIG_NFSD_V4 */
+
+			/*
+			 * Read-side load-load fence: order the field reads
+			 * above before the counter re-read below, mirroring
+			 * the smp_rmb() in the standard seqcount retry. The
+			 * begin-side smp_load_acquire() above pairs with the
+			 * smp_store_release() in nfsd_dispatch().
+			 */
+			smp_rmb();
+			if (READ_ONCE(rqstp->rq_status_counter) != status_counter)
+				continue;
+
+			ret = nfsd_genl_rpc_status_compose_msg(skb, cb,
+							       &genl_rqstp);
+			if (ret) {
+				if (skb->len) {
+					cb->args[0] = i;
+					cb->args[1] = rqstp_index - 1;
+					ret = skb->len;
+				}
+				goto out;
+			}
+		}
+	}
+
+	cb->args[0] = i;
+	cb->args[1] = rqstp_index;
+	ret = skb->len;
+out:
+	rcu_read_unlock();
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+
+	return ret;
+}
+
+/**
+ * nfsd_nl_fh_key_set - helper to copy fh_key from userspace
+ * @attr: nlattr NFSD_A_SERVER_FH_KEY
+ * @nn: nfsd_net
+ *
+ * Callers should hold nfsd_mutex, returns 0 on success or negative errno.
+ * Callers must ensure the server is shut down (sv_nrthreads == 0),
+ * userspace documentation asserts the key may only be set when the server
+ * is not running.
+ */
+static int nfsd_nl_fh_key_set(const struct nlattr *attr, struct nfsd_net *nn)
+{
+	siphash_key_t *fh_key = nn->fh_key;
+	u64 k0, k1;
+	bool changed;
+
+	k0 = get_unaligned_le64(nla_data(attr));
+	k1 = get_unaligned_le64(nla_data(attr) + 8);
+
+	if (!fh_key) {
+		fh_key = kmalloc_obj(siphash_key_t);
+		if (!fh_key) {
+			trace_nfsd_ctl_fh_key_set(false, -ENOMEM);
+			return -ENOMEM;
+		}
+		nn->fh_key = fh_key;
+		changed = true;
+	} else {
+		changed = fh_key->key[0] != k0 || fh_key->key[1] != k1;
+	}
+
+	fh_key->key[0] = k0;
+	fh_key->key[1] = k1;
+	trace_nfsd_ctl_fh_key_set(changed, 0);
+	return 0;
+}
+
+/**
+ * nfsd_nl_threads_set_doit - set the number of running threads
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	int *nthreads, nrpools = 0, i, ret = -EOPNOTSUPP, rem;
+	struct net *net = genl_info_net(info);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	const struct nlattr *attr;
+	const char *scope = NULL;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_THREADS))
+		return -EINVAL;
+
+	/* count number of SERVER_THREADS values */
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_THREADS, info->nlhdr,
+				 GENL_HDRLEN, rem)
+		nrpools++;
+
+	mutex_lock(&nfsd_mutex);
+
+	nthreads = kzalloc_objs(int, nrpools);
+	if (!nthreads) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	i = 0;
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_THREADS, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		nthreads[i++] = nla_get_u32(attr);
+		if (i >= nrpools)
+			break;
+	}
+
+	if (info->attrs[NFSD_A_SERVER_GRACETIME] ||
+	    info->attrs[NFSD_A_SERVER_LEASETIME] ||
+	    info->attrs[NFSD_A_SERVER_SCOPE] ||
+	    info->attrs[NFSD_A_SERVER_FH_KEY]) {
+		ret = -EBUSY;
+		if (nn->nfsd_serv && nn->nfsd_serv->sv_nrthreads)
+			goto out_unlock;
+
+		ret = -EINVAL;
+		attr = info->attrs[NFSD_A_SERVER_GRACETIME];
+		if (attr) {
+			u32 gracetime = nla_get_u32(attr);
+
+			if (gracetime < 10 || gracetime > 3600)
+				goto out_unlock;
+
+			nn->nfsd4_grace = gracetime;
+		}
+
+		attr = info->attrs[NFSD_A_SERVER_LEASETIME];
+		if (attr) {
+			u32 leasetime = nla_get_u32(attr);
+
+			if (leasetime < 10 || leasetime > 3600)
+				goto out_unlock;
+
+			nn->nfsd4_lease = leasetime;
+		}
+
+		attr = info->attrs[NFSD_A_SERVER_SCOPE];
+		if (attr)
+			scope = nla_data(attr);
+
+		attr = info->attrs[NFSD_A_SERVER_FH_KEY];
+		if (attr) {
+			ret = nfsd_nl_fh_key_set(attr, nn);
+			if (ret)
+				goto out_unlock;
+		}
+	}
+
+	attr = info->attrs[NFSD_A_SERVER_MIN_THREADS];
+	if (attr)
+		nn->min_threads = nla_get_u32(attr);
+
+	ret = nfsd_svc(nrpools, nthreads, net, current_cred(), scope);
+	if (ret > 0)
+		ret = 0;
+out_unlock:
+	mutex_unlock(&nfsd_mutex);
+	kfree(nthreads);
+	return ret;
+}
+
+/**
+ * nfsd_nl_threads_get_doit - get the maximum number of running threads
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	void *hdr;
+	int err;
+
+	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_iput(skb, info);
+	if (!hdr) {
+		err = -EMSGSIZE;
+		goto err_free_msg;
+	}
+
+	mutex_lock(&nfsd_mutex);
+
+	err = nla_put_u32(skb, NFSD_A_SERVER_GRACETIME,
+			  nn->nfsd4_grace) ||
+	      nla_put_u32(skb, NFSD_A_SERVER_LEASETIME,
+			  nn->nfsd4_lease) ||
+	      nla_put_u32(skb, NFSD_A_SERVER_MIN_THREADS,
+			  nn->min_threads) ||
+	      nla_put_string(skb, NFSD_A_SERVER_SCOPE,
+			  nn->nfsd_name);
+	if (err)
+		goto err_unlock;
+
+	if (nn->nfsd_serv) {
+		int i;
+
+		for (i = 0; i < nfsd_nrpools(net); ++i) {
+			struct svc_pool *sp = &nn->nfsd_serv->sv_pools[i];
+
+			err = nla_put_u32(skb, NFSD_A_SERVER_THREADS,
+					  sp->sp_nrthrmax);
+			if (err)
+				goto err_unlock;
+		}
+	} else {
+		err = nla_put_u32(skb, NFSD_A_SERVER_THREADS, 0);
+		if (err)
+			goto err_unlock;
+	}
+
+	mutex_unlock(&nfsd_mutex);
+
+	genlmsg_end(skb, hdr);
+
+	return genlmsg_reply(skb, info);
+
+err_unlock:
+	mutex_unlock(&nfsd_mutex);
+err_free_msg:
+	nlmsg_free(skb);
+
+	return err;
+}
+
+/**
+ * nfsd_nl_version_set_doit - set the nfs enabled versions
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	const struct nlattr *attr;
+	struct nfsd_net *nn;
+	int i, rem;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_PROTO_VERSION))
+		return -EINVAL;
+
+	mutex_lock(&nfsd_mutex);
+
+	nn = net_generic(genl_info_net(info), nfsd_net_id);
+	if (nn->nfsd_serv) {
+		mutex_unlock(&nfsd_mutex);
+		return -EBUSY;
+	}
+
+	/* clear current supported versions. */
+	nfsd_vers(nn, 2, NFSD_CLEAR);
+	nfsd_vers(nn, 3, NFSD_CLEAR);
+	for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
+		nfsd_minorversion(nn, i, NFSD_CLEAR);
+
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_PROTO_VERSION, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		struct nlattr *tb[NFSD_A_VERSION_MAX + 1];
+		u32 major, minor = 0;
+		bool enabled;
+
+		if (nla_parse_nested(tb, NFSD_A_VERSION_MAX, attr,
+				     nfsd_version_nl_policy, info->extack) < 0)
+			continue;
+
+		if (!tb[NFSD_A_VERSION_MAJOR])
+			continue;
+
+		major = nla_get_u32(tb[NFSD_A_VERSION_MAJOR]);
+		if (tb[NFSD_A_VERSION_MINOR])
+			minor = nla_get_u32(tb[NFSD_A_VERSION_MINOR]);
+
+		enabled = nla_get_flag(tb[NFSD_A_VERSION_ENABLED]);
+
+		switch (major) {
+		case 4:
+			nfsd_minorversion(nn, minor, enabled ? NFSD_SET : NFSD_CLEAR);
+			break;
+		case 3:
+		case 2:
+			if (!minor)
+				nfsd_vers(nn, major, enabled ? NFSD_SET : NFSD_CLEAR);
+			break;
+		default:
+			break;
+		}
+	}
+
+	mutex_unlock(&nfsd_mutex);
+
+	return 0;
+}
+
+/**
+ * nfsd_nl_version_get_doit - get the enabled status for all supported nfs versions
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfsd_net *nn;
+	int i, err;
+	void *hdr;
+
+	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_iput(skb, info);
+	if (!hdr) {
+		err = -EMSGSIZE;
+		goto err_free_msg;
+	}
+
+	mutex_lock(&nfsd_mutex);
+	nn = net_generic(genl_info_net(info), nfsd_net_id);
+
+	for (i = 2; i <= 4; i++) {
+		int j;
+
+		for (j = 0; j <= NFSD_SUPPORTED_MINOR_VERSION; j++) {
+			struct nlattr *attr;
+
+			/* Don't record any versions the kernel doesn't have
+			 * compiled in
+			 */
+			if (!nfsd_support_version(i))
+				continue;
+
+			/* NFSv{2,3} does not support minor numbers */
+			if (i < 4 && j)
+				continue;
+
+			attr = nla_nest_start(skb,
+					      NFSD_A_SERVER_PROTO_VERSION);
+			if (!attr) {
+				err = -EINVAL;
+				goto err_nfsd_unlock;
+			}
+
+			if (nla_put_u32(skb, NFSD_A_VERSION_MAJOR, i) ||
+			    nla_put_u32(skb, NFSD_A_VERSION_MINOR, j)) {
+				err = -EINVAL;
+				goto err_nfsd_unlock;
+			}
+
+			/* Set the enabled flag if the version is enabled */
+			if (nfsd_vers(nn, i, NFSD_TEST) &&
+			    (i < 4 || nfsd_minorversion(nn, j, NFSD_TEST)) &&
+			    nla_put_flag(skb, NFSD_A_VERSION_ENABLED)) {
+				err = -EINVAL;
+				goto err_nfsd_unlock;
+			}
+
+			nla_nest_end(skb, attr);
+		}
+	}
+
+	mutex_unlock(&nfsd_mutex);
+	genlmsg_end(skb, hdr);
+
+	return genlmsg_reply(skb, info);
+
+err_nfsd_unlock:
+	mutex_unlock(&nfsd_mutex);
+err_free_msg:
+	nlmsg_free(skb);
+
+	return err;
+}
+
+/**
+ * nfsd_nl_validate_listeners - sanity-check the listener list from userland
+ * @info: netlink metadata and command arguments
+ *
+ * Walk every NFSD_A_SERVER_SOCK_ADDR attribute and confirm that each entry
+ * is well-formed: it parses against the policy, carries both an address and
+ * a transport name, and the address is long enough for its family. Doing
+ * this up front lets the callers below assume every entry is valid and
+ * guarantees we make no changes when the request is malformed.
+ *
+ * Return: 0 if every entry is valid, or a negative errno otherwise.
+ */
+static int nfsd_nl_validate_listeners(struct genl_info *info)
+{
+	const struct nlattr *attr;
+	int rem;
+
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_SOCK_ADDR, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		struct nlattr *tb[NFSD_A_SOCK_MAX + 1];
+		struct sockaddr *sa;
+		int err;
+
+		err = nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr,
+				       nfsd_sock_nl_policy, info->extack);
+		if (err < 0)
+			return err;
+
+		if (!tb[NFSD_A_SOCK_ADDR] || !tb[NFSD_A_SOCK_TRANSPORT_NAME])
+			return -EINVAL;
+
+		sa = nla_data(tb[NFSD_A_SOCK_ADDR]);
+		if (nla_len(tb[NFSD_A_SOCK_ADDR]) < sizeof(sa->sa_family))
+			return -EINVAL;
+
+		switch (sa->sa_family) {
+		case AF_INET:
+			if (nla_len(tb[NFSD_A_SOCK_ADDR]) <
+			    sizeof(struct sockaddr_in))
+				return -EINVAL;
+			break;
+		case AF_INET6:
+			if (nla_len(tb[NFSD_A_SOCK_ADDR]) <
+			    sizeof(struct sockaddr_in6))
+				return -EINVAL;
+			break;
+		default:
+			return -EAFNOSUPPORT;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * nfsd_nl_listener_set_doit - set the nfs running sockets
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct svc_xprt *xprt, *tmp;
+	const struct nlattr *attr;
+	struct svc_serv *serv;
+	LIST_HEAD(permsocks);
+	struct nfsd_net *nn;
+	bool delete = false;
+	int err, rem;
+
+	/*
+	 * Validate the entire listener list before making any changes, so a
+	 * malformed request fails cleanly without creating a serv or touching
+	 * the existing listeners.
+	 */
+	err = nfsd_nl_validate_listeners(info);
+	if (err)
+		return err;
+
+	mutex_lock(&nfsd_mutex);
+
+	err = nfsd_create_serv(net);
+	if (err) {
+		mutex_unlock(&nfsd_mutex);
+		return err;
+	}
+
+	nn = net_generic(net, nfsd_net_id);
+	serv = nn->nfsd_serv;
+
+	spin_lock_bh(&serv->sv_lock);
+
+	/* Move all of the old listener sockets to a temp list */
+	list_splice_init(&serv->sv_permsocks, &permsocks);
+
+	/*
+	 * Walk the list of server_socks from userland and move any that match
+	 * back to sv_permsocks
+	 */
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_SOCK_ADDR, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		struct nlattr *tb[NFSD_A_SOCK_MAX + 1];
+		const char *xcl_name;
+		struct sockaddr *sa;
+
+		/* validated up front in nfsd_nl_validate_listeners() */
+		if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr,
+				     nfsd_sock_nl_policy, info->extack) < 0)
+			continue;
+
+		xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]);
+		sa = nla_data(tb[NFSD_A_SOCK_ADDR]);
+
+		/* Put back any matching sockets */
+		list_for_each_entry_safe(xprt, tmp, &permsocks, xpt_list) {
+			/* This shouldn't be possible */
+			if (WARN_ON_ONCE(xprt->xpt_net != net)) {
+				list_move(&xprt->xpt_list, &serv->sv_permsocks);
+				continue;
+			}
+
+			/* If everything matches, put it back */
+			if (!strcmp(xprt->xpt_class->xcl_name, xcl_name) &&
+			    rpc_cmp_addr_port(sa, (struct sockaddr *)&xprt->xpt_local)) {
+				list_move(&xprt->xpt_list, &serv->sv_permsocks);
+				break;
+			}
+		}
+	}
+
+	/*
+	 * If there are listener transports remaining on the permsocks list,
+	 * it means we were asked to remove a listener.
+	 */
+	if (!list_empty(&permsocks)) {
+		list_splice_init(&permsocks, &serv->sv_permsocks);
+		delete = true;
+	}
+	spin_unlock_bh(&serv->sv_lock);
+
+	/* Do not remove listeners while there are active threads. */
+	if (serv->sv_nrthreads) {
+		err = -EBUSY;
+		goto out_unlock_mtx;
+	}
+
+	/*
+	 * Since we can't delete an arbitrary llist entry, destroy the
+	 * remaining listeners and recreate the list.
+	 */
+	if (delete)
+		svc_xprt_destroy_all(serv, net, false);
+
+	/* walk list of addrs again, open any that still don't exist */
+	nlmsg_for_each_attr_type(attr, NFSD_A_SERVER_SOCK_ADDR, info->nlhdr,
+				 GENL_HDRLEN, rem) {
+		struct nlattr *tb[NFSD_A_SOCK_MAX + 1];
+		const char *xcl_name;
+		struct sockaddr *sa;
+		int ret;
+
+		/* validated up front in nfsd_nl_validate_listeners() */
+		if (nla_parse_nested(tb, NFSD_A_SOCK_MAX, attr,
+				     nfsd_sock_nl_policy, info->extack) < 0)
+			continue;
+
+		xcl_name = nla_data(tb[NFSD_A_SOCK_TRANSPORT_NAME]);
+		sa = nla_data(tb[NFSD_A_SOCK_ADDR]);
+
+		xprt = svc_find_listener(serv, xcl_name, net, sa);
+		if (xprt) {
+			if (delete)
+				WARN_ONCE(1, "Transport type=%s already exists\n",
+					  xcl_name);
+			svc_xprt_put(xprt);
+			continue;
+		}
+
+		ret = svc_xprt_create_from_sa(serv, xcl_name, net, sa, 0,
+					      current_cred());
+		/* always save the latest error */
+		if (ret < 0)
+			err = ret;
+	}
+
+	if (!serv->sv_nrthreads && list_empty(&nn->nfsd_serv->sv_permsocks))
+		nfsd_destroy_serv(net);
+
+out_unlock_mtx:
+	mutex_unlock(&nfsd_mutex);
+
+	return err;
+}
+
+/**
+ * nfsd_nl_listener_get_doit - get the nfs running listeners
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct svc_xprt *xprt;
+	struct svc_serv *serv;
+	struct nfsd_net *nn;
+	void *hdr;
+	int err;
+
+	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_iput(skb, info);
+	if (!hdr) {
+		err = -EMSGSIZE;
+		goto err_free_msg;
+	}
+
+	mutex_lock(&nfsd_mutex);
+	nn = net_generic(genl_info_net(info), nfsd_net_id);
+
+	/* no nfs server? Just send empty socket list */
+	if (!nn->nfsd_serv)
+		goto out_unlock_mtx;
+
+	serv = nn->nfsd_serv;
+	spin_lock_bh(&serv->sv_lock);
+	list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
+		struct nlattr *attr;
+
+		attr = nla_nest_start(skb, NFSD_A_SERVER_SOCK_ADDR);
+		if (!attr) {
+			err = -EINVAL;
+			goto err_serv_unlock;
+		}
+
+		if (nla_put_string(skb, NFSD_A_SOCK_TRANSPORT_NAME,
+				   xprt->xpt_class->xcl_name) ||
+		    nla_put(skb, NFSD_A_SOCK_ADDR,
+			    sizeof(struct sockaddr_storage),
+			    &xprt->xpt_local)) {
+			err = -EINVAL;
+			goto err_serv_unlock;
+		}
+
+		nla_nest_end(skb, attr);
+	}
+	spin_unlock_bh(&serv->sv_lock);
+out_unlock_mtx:
+	mutex_unlock(&nfsd_mutex);
+	genlmsg_end(skb, hdr);
+
+	return genlmsg_reply(skb, info);
+
+err_serv_unlock:
+	spin_unlock_bh(&serv->sv_lock);
+	mutex_unlock(&nfsd_mutex);
+err_free_msg:
+	nlmsg_free(skb);
+
+	return err;
+}
+
+/**
+ * nfsd_nl_pool_mode_set_doit - set the number of running threads
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_pool_mode_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	const struct nlattr *attr;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_POOL_MODE_MODE))
+		return -EINVAL;
+
+	attr = info->attrs[NFSD_A_POOL_MODE_MODE];
+	return sunrpc_set_pool_mode(nla_data(attr));
+}
+
+/**
+ * nfsd_nl_pool_mode_get_doit - get info about pool_mode
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	char buf[16];
+	void *hdr;
+	int err;
+
+	if (sunrpc_get_pool_mode(buf, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+		return -ERANGE;
+
+	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	err = -EMSGSIZE;
+	hdr = genlmsg_iput(skb, info);
+	if (!hdr)
+		goto err_free_msg;
+
+	err = nla_put_string(skb, NFSD_A_POOL_MODE_MODE, buf) |
+	      nla_put_u32(skb, NFSD_A_POOL_MODE_NPOOLS, nfsd_nrpools(net));
+	if (err)
+		goto err_free_msg;
+
+	genlmsg_end(skb, hdr);
+	return genlmsg_reply(skb, info);
+
+err_free_msg:
+	nlmsg_free(skb);
+	return err;
+}
+
+/**
+ * nfsd_nl_cache_flush_doit - flush nfsd caches via netlink
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Flush the svc_export and/or expkey caches. If NFSD_A_CACHE_FLUSH_MASK
+ * is provided, only flush the caches indicated by the bitmask (bit 0 =
+ * svc_export, bit 1 = expkey). If omitted, flush both.
+ *
+ * Return 0 on success or a negative errno.
+ */
+int nfsd_nl_cache_flush_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	u32 mask = ~0U;
+
+	if (info->attrs[NFSD_A_CACHE_FLUSH_MASK])
+		mask = nla_get_u32(info->attrs[NFSD_A_CACHE_FLUSH_MASK]);
+
+	mutex_lock(&nfsd_mutex);
+
+	if ((mask & NFSD_CACHE_TYPE_SVC_EXPORT) &&
+	    nn->svc_export_cache)
+		cache_purge(nn->svc_export_cache);
+
+	if ((mask & NFSD_CACHE_TYPE_EXPKEY) &&
+	    nn->svc_expkey_cache)
+		cache_purge(nn->svc_expkey_cache);
+
+	mutex_unlock(&nfsd_mutex);
+
+	return 0;
+}
+
+/* Emit a single server-proc-entry nest: { op, count }. */
+static int nfsd_nl_put_proc_entry(struct sk_buff *skb, int attr,
+				  u32 op, u64 count)
+{
+	struct nlattr *nest;
+
+	nest = nla_nest_start(skb, attr);
+	if (!nest)
+		return -EMSGSIZE;
+	if (nla_put_u32(skb, NFSD_A_SERVER_PROC_ENTRY_OP, op) ||
+	    nla_put_u64_64bit(skb, NFSD_A_SERVER_PROC_ENTRY_COUNT,
+			      count, NFSD_A_SERVER_PROC_ENTRY_PAD)) {
+		nla_nest_cancel(skb, nest);
+		return -EMSGSIZE;
+	}
+	nla_nest_end(skb, nest);
+	return 0;
+}
+
+/* Emit the scalar server-stats counters. Only ever called on a fresh skb. */
+static int nfsd_nl_server_stats_scalars(struct sk_buff *skb,
+					struct nfsd_net *nn,
+					struct svc_stat *statp)
+{
+	if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_HITS,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_HITS]),
+			NFSD_A_SERVER_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_MISSES,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_MISSES]),
+			NFSD_A_SERVER_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_NOCACHE,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_NOCACHE]),
+			NFSD_A_SERVER_STATS_PAD))
+		return -EMSGSIZE;
+
+	if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_FH_STALE,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_FH_STALE]),
+			NFSD_A_SERVER_STATS_PAD))
+		return -EMSGSIZE;
+
+	if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_IO_READ,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_READ]),
+			NFSD_A_SERVER_STATS_PAD) ||
+	    nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_IO_WRITE,
+			percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_WRITE]),
+			NFSD_A_SERVER_STATS_PAD))
+		return -EMSGSIZE;
+
+	if (nla_put_u32(skb, NFSD_A_SERVER_STATS_NETCNT, statp->netcnt) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_NETUDPCNT, statp->netudpcnt) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_NETTCPCNT, statp->nettcpcnt) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_NETTCPCONN, statp->nettcpconn))
+		return -EMSGSIZE;
+
+	if (nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCCNT, statp->rpccnt) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADFMT, statp->rpcbadfmt) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADAUTH, statp->rpcbadauth) ||
+	    nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADCLNT, statp->rpcbadclnt))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+/*
+ * Emit per-version procedure counts for one NFS version, resuming at *idx.
+ * Returns 0 when the version has been fully emitted (or is not present), or
+ * -EMSGSIZE when @skb filled up, leaving *idx at the entry still to emit.
+ */
+static int nfsd_nl_server_stats_proc(struct sk_buff *skb,
+				     struct svc_stat *statp,
+				     struct svc_program *prog,
+				     unsigned int ver, int attr, int *idx)
+{
+	unsigned long __percpu *counts;
+	unsigned int nproc;
+
+	if (!statp->vs_count || ver >= prog->pg_nvers ||
+	    !prog->pg_vers[ver] || !statp->vs_count[ver])
+		return 0;
+
+	counts = statp->vs_count[ver];
+	nproc = prog->pg_vers[ver]->vs_nproc;
+
+	for (; *idx < nproc; (*idx)++) {
+		unsigned long count = 0;
+		int cpu;
+
+		for_each_possible_cpu(cpu)
+			count += per_cpu(counts[*idx], cpu);
+
+		if (!count)
+			continue;
+		if (nfsd_nl_put_proc_entry(skb, attr, *idx, count))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_NFSD_V4
+/*
+ * Emit NFSv4 per-operation counts, resuming at *idx. Same return convention
+ * as nfsd_nl_server_stats_proc().
+ */
+static int nfsd_nl_server_stats_nfs4ops(struct sk_buff *skb,
+					struct nfsd_net *nn, int *idx)
+{
+	for (; *idx <= LAST_NFS4_OP; (*idx)++) {
+		u64 cnt = percpu_counter_sum_positive(
+				&nn->counter[NFSD_STATS_NFS4_OP(*idx)]);
+
+		if (!cnt)
+			continue;
+		if (nfsd_nl_put_proc_entry(skb, NFSD_A_SERVER_STATS_PROC4OPS_OPS,
+					   *idx, cnt))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+/*
+ * Emit NFSv4 callback (backchannel) per-operation counts, resuming at *idx,
+ * which counts from OP_CB_GETATTR. Same return convention as
+ * nfsd_nl_server_stats_proc().
+ */
+static int nfsd_nl_server_stats_cbops(struct sk_buff *skb,
+				      struct nfsd_net *nn, int *idx)
+{
+	int op;
+
+	for (op = OP_CB_GETATTR + *idx; op <= OP_CB_OFFLOAD; op++, (*idx)++) {
+		u64 cnt = percpu_counter_sum_positive(&nn->cb_counter[op]);
+
+		if (!cnt)
+			continue;
+		if (nfsd_nl_put_proc_entry(skb, NFSD_A_SERVER_STATS_PROC4CB_OPS,
+					   op, cnt))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+#endif
+
+/* Sections of the server-stats dump, emitted in order across messages. */
+enum {
+	NFSD_SERVER_STATS_SCALARS = 0,
+	NFSD_SERVER_STATS_PROC2,
+	NFSD_SERVER_STATS_PROC3,
+	NFSD_SERVER_STATS_PROC4,
+	NFSD_SERVER_STATS_PROC4CB,
+	NFSD_SERVER_STATS_PROC4OPS,
+	NFSD_SERVER_STATS_DONE,
+};
+
+/**
+ * nfsd_nl_server_stats_get_dumpit - dump NFS server statistics
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * The server-stats object is emitted across one or more netlink messages.
+ * cb->args[0] tracks the current section and cb->args[1] the entry index
+ * within it, so a section that does not fit in the current message is resumed
+ * in the next one. The scalar counters are small and emitted once, in the
+ * first message; userspace merges the attributes from every message.
+ *
+ * Returns the size of the reply or a negative errno.
+ */
+int nfsd_nl_server_stats_get_dumpit(struct sk_buff *skb,
+				    struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_stat *statp = &nn->nfsd_svcstats;
+	struct svc_program *prog = statp->program;
+	int section = cb->args[0];
+	int idx = cb->args[1];
+	void *hdr;
+
+	if (section >= NFSD_SERVER_STATS_DONE)
+		return 0;
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
+			  cb->nlh->nlmsg_seq, &nfsd_nl_family,
+			  NLM_F_MULTI, NFSD_CMD_SERVER_STATS_GET);
+	if (!hdr)
+		return -ENOBUFS;
+
+	/* Scalar stats fit easily and are emitted in the first message. */
+	if (section == NFSD_SERVER_STATS_SCALARS) {
+		if (nfsd_nl_server_stats_scalars(skb, nn, statp))
+			goto err_cancel;
+		section = NFSD_SERVER_STATS_PROC2;
+		idx = 0;
+	}
+
+	/*
+	 * Emit as many of the remaining sections as fit. A section returning
+	 * -EMSGSIZE means the message is full: close it and resume from the
+	 * same section/index on the next call with a fresh skb. Each entry is
+	 * small enough to fit in a fresh skb, so forward progress is assured.
+	 */
+	while (section < NFSD_SERVER_STATS_DONE) {
+		int ret = 0;
+
+		switch (section) {
+		case NFSD_SERVER_STATS_PROC2:
+			ret = nfsd_nl_server_stats_proc(skb, statp, prog, 2,
+					NFSD_A_SERVER_STATS_PROC2_OPS, &idx);
+			break;
+		case NFSD_SERVER_STATS_PROC3:
+			ret = nfsd_nl_server_stats_proc(skb, statp, prog, 3,
+					NFSD_A_SERVER_STATS_PROC3_OPS, &idx);
+			break;
+		case NFSD_SERVER_STATS_PROC4:
+			ret = nfsd_nl_server_stats_proc(skb, statp, prog, 4,
+					NFSD_A_SERVER_STATS_PROC4_OPS, &idx);
+			break;
+#ifdef CONFIG_NFSD_V4
+		case NFSD_SERVER_STATS_PROC4CB:
+			ret = nfsd_nl_server_stats_cbops(skb, nn, &idx);
+			break;
+		case NFSD_SERVER_STATS_PROC4OPS:
+			ret = nfsd_nl_server_stats_nfs4ops(skb, nn, &idx);
+			break;
+#endif
+		}
+
+		if (ret == -EMSGSIZE)
+			goto out;
+		if (ret)
+			goto err_cancel;
+
+		section++;
+		idx = 0;
+	}
+
+out:
+	genlmsg_end(skb, hdr);
+	cb->args[0] = section;
+	cb->args[1] = idx;
+	return skb->len;
+
+err_cancel:
+	genlmsg_cancel(skb, hdr);
+	return -EMSGSIZE;
+}
+
+int nfsd_cache_notify(struct cache_detail *cd, struct cache_head *h, u32 cache_type)
+{
+	struct genlmsghdr *hdr;
+	struct sk_buff *msg;
+
+	if (!genl_has_listeners(&nfsd_nl_family, cd->net, NFSD_NLGRP_EXPORTD))
+		return -ENOLINK;
+
+	msg = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(msg, 0, 0, &nfsd_nl_family, 0, NFSD_CMD_CACHE_NOTIFY);
+	if (!hdr) {
+		nlmsg_free(msg);
+		return -ENOMEM;
+	}
+
+	if (nla_put_u32(msg, NFSD_A_CACHE_NOTIFY_CACHE_TYPE, cache_type)) {
+		nlmsg_free(msg);
+		return -ENOMEM;
+	}
+
+	genlmsg_end(msg, hdr);
+	return genlmsg_multicast_netns(&nfsd_nl_family, cd->net, msg, 0,
+				       NFSD_NLGRP_EXPORTD, GFP_KERNEL);
+}
+
+/**
+ * nfsd_nl_unlock_ip_doit - release NLM locks held by an IP address
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return: 0 on success or a negative errno.
+ */
+int nfsd_nl_unlock_ip_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sockaddr *sap;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_UNLOCK_IP_ADDRESS))
+		return -EINVAL;
+	sap = nla_data(info->attrs[NFSD_A_UNLOCK_IP_ADDRESS]);
+	switch (sap->sa_family) {
+	case AF_INET:
+		if (nla_len(info->attrs[NFSD_A_UNLOCK_IP_ADDRESS]) <
+		    sizeof(struct sockaddr_in))
+			return -EINVAL;
+		break;
+	case AF_INET6:
+		if (nla_len(info->attrs[NFSD_A_UNLOCK_IP_ADDRESS]) <
+		    sizeof(struct sockaddr_in6))
+			return -EINVAL;
+		break;
+	default:
+		return -EAFNOSUPPORT;
+	}
+	/*
+	 * nlmsvc_unlock_all_by_ip() releases matching locks
+	 * across all network namespaces because lockd operates
+	 * a single global instance.
+	 */
+	trace_nfsd_ctl_unlock_ip(genl_info_net(info), sap,
+				 svc_addr_len(sap));
+	return nlmsvc_unlock_all_by_ip(sap);
+}
+
+/**
+ * nfsd_nl_unlock_filesystem_doit - revoke NFS state under a filesystem path
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Return: 0 on success or a negative errno.
+ */
+int nfsd_nl_unlock_filesystem_doit(struct sk_buff *skb,
+				   struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct path path;
+	int error;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_UNLOCK_FILESYSTEM_PATH))
+		return -EINVAL;
+
+	trace_nfsd_ctl_unlock_fs(net,
+			nla_data(info->attrs[NFSD_A_UNLOCK_FILESYSTEM_PATH]));
+	error = kern_path(
+			nla_data(info->attrs[NFSD_A_UNLOCK_FILESYSTEM_PATH]),
+			0, &path);
+	if (error)
+		return error;
+
+	error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
+
+	mutex_lock(&nfsd_mutex);
+	if (test_bit(NFSD_NET_UP, &nn->flags)) {
+		nfsd4_cancel_copy_by_sb(net, path.dentry->d_sb);
+		nfsd4_revoke_states(nn, path.dentry->d_sb);
+	} else {
+		error = -EINVAL;
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	path_put(&path);
+	return error;
+}
+
+/**
+ * nfsd_nl_unlock_export_doit - revoke NFSv4 state for an export path
+ * @skb: reply buffer
+ * @info: netlink metadata and command arguments
+ *
+ * Revokes all NFSv4 state (opens, locks, delegations, layouts) acquired
+ * through any export of the given path, regardless of which client holds
+ * the state.  Userspace (exportfs -u) sends this after removing the last
+ * client for a path so the underlying filesystem can be unmounted.
+ *
+ * Unlike NFSD_CMD_UNLOCK_FILESYSTEM, which operates at superblock
+ * granularity, this command revokes only the state associated with
+ * exports of a specific path.
+ *
+ * Return: 0 on success or a negative errno.
+ */
+int nfsd_nl_unlock_export_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct path path;
+	int error;
+
+	if (GENL_REQ_ATTR_CHECK(info, NFSD_A_UNLOCK_EXPORT_PATH))
+		return -EINVAL;
+
+	trace_nfsd_ctl_unlock_export(net,
+			nla_data(info->attrs[NFSD_A_UNLOCK_EXPORT_PATH]));
+	error = kern_path(
+			nla_data(info->attrs[NFSD_A_UNLOCK_EXPORT_PATH]),
+			0, &path);
+	if (error)
+		return error;
+
+	mutex_lock(&nfsd_mutex);
+	if (test_bit(NFSD_NET_UP, &nn->flags)) {
+		nfsd_file_close_export(net, &path);
+		nfsd4_revoke_export_states(nn, &path);
+	} else
+		error = -EINVAL;
+	mutex_unlock(&nfsd_mutex);
+
+	path_put(&path);
+	return error;
+}
+
+/**
+ * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace
+ * @net: a freshly-created network namespace
+ *
+ * This information stays around as long as the network namespace is
+ * alive whether or not there is an NFSD instance running in the
+ * namespace.
+ *
+ * Returns zero on success, or a negative errno otherwise.
+ */
+static __net_init int nfsd_net_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int retval;
+	int i;
+
+	retval = nfsd_net_cb_init(nn);
+	if (retval)
+		return retval;
+	retval = nfsd_export_init(net);
+	if (retval)
+		goto out_export_error;
+	retval = nfsd_idmap_init(net);
+	if (retval)
+		goto out_idmap_error;
+	retval = percpu_counter_init_many(nn->counter, 0, GFP_KERNEL,
+					  NFSD_STATS_COUNTERS_NUM);
+	if (retval)
+		goto out_repcache_error;
+
+#ifdef CONFIG_NFSD_V4
+	retval = percpu_counter_init_many(nn->cb_counter, 0, GFP_KERNEL,
+					  NFSD_STATS_CB_OPS_NUM);
+	if (retval)
+		goto out_cb_counter_error;
+#endif
+
+	memset(&nn->nfsd_svcstats, 0, sizeof(nn->nfsd_svcstats));
+	nn->nfsd_svcstats.program = &nfsd_programs[0];
+	retval = svc_stat_alloc_counts(&nn->nfsd_svcstats);
+	if (retval)
+		goto out_proc_error;
+	if (!nfsd_proc_stat_init(net)) {
+		retval = -ENOMEM;
+		goto out_svcstats_error;
+	}
+
+	for (i = 0; i < sizeof(nn->nfsd_versions); i++)
+		nn->nfsd_versions[i] = nfsd_support_version(i);
+	for (i = 0; i < sizeof(nn->nfsd4_minorversions); i++)
+		nn->nfsd4_minorversions[i] = nfsd_support_version(4);
+	nn->nfsd_info.mutex = &nfsd_mutex;
+	nn->nfsd_serv = NULL;
+	nfsd4_init_leases_net(nn);
+	get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key));
+	seqlock_init(&nn->writeverf_lock);
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	spin_lock_init(&nn->local_clients_lock);
+	INIT_LIST_HEAD(&nn->local_clients);
+#endif
+	return 0;
+
+out_svcstats_error:
+	svc_stat_free_counts(&nn->nfsd_svcstats);
+out_proc_error:
+#ifdef CONFIG_NFSD_V4
+	percpu_counter_destroy_many(nn->cb_counter, NFSD_STATS_CB_OPS_NUM);
+out_cb_counter_error:
+#endif
+	percpu_counter_destroy_many(nn->counter, NFSD_STATS_COUNTERS_NUM);
+out_repcache_error:
+	nfsd_idmap_shutdown(net);
+out_idmap_error:
+	nfsd_export_shutdown(net);
+out_export_error:
+	nfsd_net_cb_shutdown(nn);
+	return retval;
+}
+
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+/**
+ * nfsd_net_pre_exit - Disconnect localio clients from net namespace
+ * @net: a network namespace that is about to be destroyed
+ *
+ * This invalidates ->net pointers held by localio clients
+ * while they can still safely access nn->counter.
+ */
+static __net_exit void nfsd_net_pre_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs_localio_invalidate_clients(&nn->local_clients,
+				       &nn->local_clients_lock);
+}
+#endif
+
+/**
+ * nfsd_net_exit - Release the nfsd_net portion of a net namespace
+ * @net: a network namespace that is about to be destroyed
+ *
+ */
+static __net_exit void nfsd_net_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	kfree_sensitive(nn->fh_key);
+	nfsd_net_cb_shutdown(nn);
+	nfsd_proc_stat_shutdown(net);
+	svc_stat_free_counts(&nn->nfsd_svcstats);
+#ifdef CONFIG_NFSD_V4
+	percpu_counter_destroy_many(nn->cb_counter, NFSD_STATS_CB_OPS_NUM);
+#endif
+	percpu_counter_destroy_many(nn->counter, NFSD_STATS_COUNTERS_NUM);
+	nfsd_idmap_shutdown(net);
+	nfsd_export_shutdown(net);
+}
+
+static struct pernet_operations nfsd_net_ops = {
+	.init = nfsd_net_init,
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	.pre_exit = nfsd_net_pre_exit,
+#endif
+	.exit = nfsd_net_exit,
+	.id   = &nfsd_net_id,
+	.size = sizeof(struct nfsd_net),
+};
+
+static int __init init_nfsd(void)
+{
+	int retval;
+
+	retval = nfsd4_init_slabs();
+	if (retval)
+		return retval;
+
+	nfsd_debugfs_init();
+
+	retval = nfsd4_init_pnfs();
+	if (retval)
+		goto out_free_slabs;
+	retval = nfsd_drc_slab_create();
+	if (retval)
+		goto out_free_pnfs;
+	nfsd_lockd_init();	/* lockd->nfsd callbacks */
+	retval = register_pernet_subsys(&nfsd_net_ops);
+	if (retval < 0)
+		goto out_free_lockd;
+	retval = register_cld_notifier();
+	if (retval)
+		goto out_free_subsys;
+	retval = nfsd4_create_laundry_wq();
+	if (retval)
+		goto out_free_cld;
+	retval = register_filesystem(&nfsd_fs_type);
+	if (retval)
+		goto out_free_nfsd4;
+	retval = genl_register_family(&nfsd_nl_family);
+	if (retval)
+		goto out_free_filesystem;
+	retval = create_proc_exports_entry();
+	if (retval)
+		goto out_free_all;
+	nfsd_localio_ops_init();
+
+	return 0;
+out_free_all:
+	genl_unregister_family(&nfsd_nl_family);
+out_free_filesystem:
+	unregister_filesystem(&nfsd_fs_type);
+out_free_nfsd4:
+	nfsd4_destroy_laundry_wq();
+out_free_cld:
+	unregister_cld_notifier();
+out_free_subsys:
+	unregister_pernet_subsys(&nfsd_net_ops);
+out_free_lockd:
+	nfsd_lockd_shutdown();
+	nfsd_drc_slab_free();
+out_free_pnfs:
+	nfsd4_exit_pnfs();
+out_free_slabs:
+	nfsd_debugfs_exit();
+	nfsd4_free_slabs();
+	return retval;
+}
+
+static void __exit exit_nfsd(void)
+{
+	remove_proc_entry("fs/nfs/exports", NULL);
+	remove_proc_entry("fs/nfs", NULL);
+	genl_unregister_family(&nfsd_nl_family);
+	unregister_filesystem(&nfsd_fs_type);
+	nfsd4_destroy_laundry_wq();
+	unregister_cld_notifier();
+	unregister_pernet_subsys(&nfsd_net_ops);
+	nfsd_drc_slab_free();
+	nfsd_lockd_shutdown();
+	nfsd4_exit_pnfs();
+	nfsd_debugfs_exit();
+	nfsd4_free_slabs();
+}
+
+MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
+MODULE_DESCRIPTION("In-kernel NFS server");
+MODULE_LICENSE("GPL");
+module_init(init_nfsd)
+module_exit(exit_nfsd)
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
new file mode 100644
index 000000000..76a69d9a4
--- /dev/null
+++ b/fs/nfsd/nfsd.h
@@ -0,0 +1,392 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Hodge-podge collection of knfsd-related stuff.
+ * I will sort this out later.
+ *
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_NFSD_H
+#define LINUX_NFSD_NFSD_H
+
+#include <linux/types.h>
+#include <linux/mount.h>
+
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#include <uapi/linux/nfsd/debug.h>
+
+#undef ifdebug
+#ifdef CONFIG_SUNRPC_DEBUG
+# define ifdebug(flag)		if (nfsd_debug & NFSDDBG_##flag)
+#else
+# define ifdebug(flag)		if (0)
+#endif
+
+/*
+ * nfsd version
+ */
+#define NFSD_MINVERS			2
+#define	NFSD_MAXVERS			4
+#define NFSD_SUPPORTED_MINOR_VERSION	2
+bool nfsd_support_version(int vers);
+
+/*
+ * Default and maximum payload size (NFS READ or WRITE), in bytes.
+ * The maximum is an implementation limit.
+ */
+enum {
+	NFSSVC_DEFBLKSIZE       = 4 * 1024 * 1024,
+	NFSSVC_MAXBLKSIZE       = RPCSVC_MAXPAYLOAD,
+};
+
+/* Maximum number of operations per session compound */
+#define NFSD_MAX_OPS_PER_COMPOUND	200
+
+extern struct svc_program	nfsd_programs[];
+extern const struct svc_version	nfsd_version2, nfsd_version3, nfsd_version4;
+extern struct mutex		nfsd_mutex;
+extern atomic_t			nfsd_th_cnt;		/* number of available threads */
+
+extern const struct seq_operations nfs_exports_op;
+
+struct nfsd_thread_local_info {
+	struct nfs4_client	**ntli_lease_breaker;
+	int			ntli_cachetype;
+};
+
+/*
+ * Common void argument and result helpers
+ */
+struct nfsd_voidargs { };
+struct nfsd_voidres { };
+bool		nfssvc_decode_voidarg(struct svc_rqst *rqstp,
+				      struct xdr_stream *xdr);
+bool		nfssvc_encode_voidres(struct svc_rqst *rqstp,
+				      struct xdr_stream *xdr);
+
+/*
+ * Function prototypes.
+ */
+int		nfsd_svc(int n, int *nservers, struct net *net,
+			 const struct cred *cred, const char *scope);
+int		nfsd_dispatch(struct svc_rqst *rqstp);
+
+int		nfsd_nrthreads(struct net *);
+int		nfsd_nrpools(struct net *);
+int		nfsd_get_nrthreads(int n, int *, struct net *);
+int		nfsd_set_nrthreads(int n, int *, struct net *);
+void		nfsd_shutdown_threads(struct net *net);
+
+struct svc_rqst *nfsd_current_rqst(void);
+
+struct nfsdfs_client {
+	struct kref cl_ref;
+	void (*cl_release)(struct kref *kref);
+};
+
+struct nfsd_net;
+
+struct nfsdfs_client *get_nfsdfs_client(struct inode *);
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
+				 struct nfsdfs_client *ncl, u32 id,
+				 const struct tree_descr *,
+				 struct dentry **fdentries);
+void nfsd_client_rmdir(struct dentry *dentry);
+int nfsd_cache_notify(struct cache_detail *cd, struct cache_head *h, u32 cache_type);
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+#ifdef CONFIG_NFSD_V2_ACL
+extern const struct svc_version nfsd_acl_version2;
+#else
+#define nfsd_acl_version2 NULL
+#endif
+#ifdef CONFIG_NFSD_V3_ACL
+extern const struct svc_version nfsd_acl_version3;
+#else
+#define nfsd_acl_version3 NULL
+#endif
+#endif
+
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+extern const struct svc_version localio_version1;
+#endif
+
+enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
+void nfsd_reset_versions(struct nfsd_net *nn);
+int nfsd_create_serv(struct net *net);
+void nfsd_destroy_serv(struct net *net);
+
+#ifdef CONFIG_DEBUG_FS
+void nfsd_debugfs_init(void);
+void nfsd_debugfs_exit(void);
+#else
+static inline void nfsd_debugfs_init(void) {}
+static inline void nfsd_debugfs_exit(void) {}
+#endif
+
+extern bool nfsd_disable_splice_read __read_mostly;
+extern bool nfsd_delegts_enabled __read_mostly;
+
+enum {
+	/* Any new NFSD_IO enum value must be added at the end */
+	NFSD_IO_BUFFERED,
+	NFSD_IO_DONTCACHE,
+	NFSD_IO_DIRECT,
+};
+
+extern u64 nfsd_io_cache_read __read_mostly;
+extern u64 nfsd_io_cache_write __read_mostly;
+
+extern int nfsd_max_blksize;
+
+static inline int nfsd_v4client(struct svc_rqst *rq)
+{
+	return rq && rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
+}
+
+/* 
+ * NFSv4 State
+ */
+#ifdef CONFIG_NFSD_V4
+extern unsigned long max_delegations;
+int nfsd4_init_slabs(void);
+void nfsd4_free_slabs(void);
+int nfs4_state_start(void);
+int nfs4_state_start_net(struct net *net);
+void nfs4_state_shutdown(void);
+void nfs4_state_shutdown_net(struct net *net);
+int nfs4_reset_recoverydir(char *recdir);
+char * nfs4_recoverydir(void);
+bool nfsd4_spo_must_allow(struct svc_rqst *rqstp);
+int nfsd4_create_laundry_wq(void);
+void nfsd4_destroy_laundry_wq(void);
+bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp, struct inode *inode);
+#else
+static inline int nfsd4_init_slabs(void) { return 0; }
+static inline void nfsd4_free_slabs(void) { }
+static inline int nfs4_state_start(void) { return 0; }
+static inline int nfs4_state_start_net(struct net *net) { return 0; }
+static inline void nfs4_state_shutdown(void) { }
+static inline void nfs4_state_shutdown_net(struct net *net) { }
+static inline int nfs4_reset_recoverydir(char *recdir) { return 0; }
+static inline char * nfs4_recoverydir(void) {return NULL; }
+static inline bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
+{
+	return false;
+}
+static inline int nfsd4_create_laundry_wq(void) { return 0; };
+static inline void nfsd4_destroy_laundry_wq(void) {};
+static inline bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp,
+					      struct inode *inode)
+{
+	return false;
+}
+#endif
+
+/*
+ * lockd binding
+ */
+void		nfsd_lockd_init(void);
+void		nfsd_lockd_shutdown(void);
+
+
+/*
+ * These macros provide pre-xdr'ed values for faster operation.
+ */
+#define	nfs_ok			cpu_to_be32(NFS_OK)
+#define	nfserr_perm		cpu_to_be32(NFSERR_PERM)
+#define	nfserr_noent		cpu_to_be32(NFSERR_NOENT)
+#define	nfserr_io		cpu_to_be32(NFSERR_IO)
+#define	nfserr_nxio		cpu_to_be32(NFSERR_NXIO)
+#define	nfserr_acces		cpu_to_be32(NFSERR_ACCES)
+#define	nfserr_exist		cpu_to_be32(NFSERR_EXIST)
+#define	nfserr_xdev		cpu_to_be32(NFSERR_XDEV)
+#define	nfserr_nodev		cpu_to_be32(NFSERR_NODEV)
+#define	nfserr_notdir		cpu_to_be32(NFSERR_NOTDIR)
+#define	nfserr_isdir		cpu_to_be32(NFSERR_ISDIR)
+#define	nfserr_inval		cpu_to_be32(NFSERR_INVAL)
+#define	nfserr_fbig		cpu_to_be32(NFSERR_FBIG)
+#define	nfserr_nospc		cpu_to_be32(NFSERR_NOSPC)
+#define	nfserr_rofs		cpu_to_be32(NFSERR_ROFS)
+#define	nfserr_mlink		cpu_to_be32(NFSERR_MLINK)
+#define	nfserr_nametoolong	cpu_to_be32(NFSERR_NAMETOOLONG)
+#define	nfserr_notempty		cpu_to_be32(NFSERR_NOTEMPTY)
+#define	nfserr_dquot		cpu_to_be32(NFSERR_DQUOT)
+#define	nfserr_stale		cpu_to_be32(NFSERR_STALE)
+#define	nfserr_remote		cpu_to_be32(NFSERR_REMOTE)
+#define	nfserr_wflush		cpu_to_be32(NFSERR_WFLUSH)
+#define	nfserr_badhandle	cpu_to_be32(NFSERR_BADHANDLE)
+#define	nfserr_notsync		cpu_to_be32(NFSERR_NOT_SYNC)
+#define	nfserr_badcookie	cpu_to_be32(NFSERR_BAD_COOKIE)
+#define	nfserr_notsupp		cpu_to_be32(NFSERR_NOTSUPP)
+#define	nfserr_toosmall		cpu_to_be32(NFSERR_TOOSMALL)
+#define	nfserr_serverfault	cpu_to_be32(NFSERR_SERVERFAULT)
+#define	nfserr_badtype		cpu_to_be32(NFSERR_BADTYPE)
+#define	nfserr_jukebox		cpu_to_be32(NFSERR_JUKEBOX)
+#define	nfserr_denied		cpu_to_be32(NFSERR_DENIED)
+#define	nfserr_deadlock		cpu_to_be32(NFSERR_DEADLOCK)
+#define nfserr_expired          cpu_to_be32(NFSERR_EXPIRED)
+#define	nfserr_bad_cookie	cpu_to_be32(NFSERR_BAD_COOKIE)
+#define	nfserr_same		cpu_to_be32(NFSERR_SAME)
+#define	nfserr_clid_inuse	cpu_to_be32(NFSERR_CLID_INUSE)
+#define	nfserr_stale_clientid	cpu_to_be32(NFSERR_STALE_CLIENTID)
+#define	nfserr_resource		cpu_to_be32(NFSERR_RESOURCE)
+#define	nfserr_moved		cpu_to_be32(NFSERR_MOVED)
+#define	nfserr_nofilehandle	cpu_to_be32(NFSERR_NOFILEHANDLE)
+#define	nfserr_minor_vers_mismatch	cpu_to_be32(NFSERR_MINOR_VERS_MISMATCH)
+#define nfserr_share_denied	cpu_to_be32(NFSERR_SHARE_DENIED)
+#define nfserr_stale_stateid	cpu_to_be32(NFSERR_STALE_STATEID)
+#define nfserr_old_stateid	cpu_to_be32(NFSERR_OLD_STATEID)
+#define nfserr_bad_stateid	cpu_to_be32(NFSERR_BAD_STATEID)
+#define nfserr_bad_seqid	cpu_to_be32(NFSERR_BAD_SEQID)
+#define	nfserr_symlink		cpu_to_be32(NFSERR_SYMLINK)
+#define	nfserr_not_same		cpu_to_be32(NFSERR_NOT_SAME)
+#define nfserr_lock_range	cpu_to_be32(NFSERR_LOCK_RANGE)
+#define	nfserr_restorefh	cpu_to_be32(NFSERR_RESTOREFH)
+#define	nfserr_attrnotsupp	cpu_to_be32(NFSERR_ATTRNOTSUPP)
+#define	nfserr_bad_xdr		cpu_to_be32(NFSERR_BAD_XDR)
+#define	nfserr_openmode		cpu_to_be32(NFSERR_OPENMODE)
+#define	nfserr_badowner		cpu_to_be32(NFSERR_BADOWNER)
+#define	nfserr_locks_held	cpu_to_be32(NFSERR_LOCKS_HELD)
+#define	nfserr_op_illegal	cpu_to_be32(NFSERR_OP_ILLEGAL)
+#define	nfserr_grace		cpu_to_be32(NFSERR_GRACE)
+#define	nfserr_no_grace		cpu_to_be32(NFSERR_NO_GRACE)
+#define	nfserr_reclaim_bad	cpu_to_be32(NFSERR_RECLAIM_BAD)
+#define	nfserr_badname		cpu_to_be32(NFSERR_BADNAME)
+#define	nfserr_admin_revoked	cpu_to_be32(NFS4ERR_ADMIN_REVOKED)
+#define	nfserr_cb_path_down	cpu_to_be32(NFSERR_CB_PATH_DOWN)
+#define	nfserr_locked		cpu_to_be32(NFSERR_LOCKED)
+#define	nfserr_wrongsec		cpu_to_be32(NFSERR_WRONGSEC)
+#define nfserr_delay			cpu_to_be32(NFS4ERR_DELAY)
+#define nfserr_badiomode		cpu_to_be32(NFS4ERR_BADIOMODE)
+#define nfserr_badlayout		cpu_to_be32(NFS4ERR_BADLAYOUT)
+#define nfserr_bad_session_digest	cpu_to_be32(NFS4ERR_BAD_SESSION_DIGEST)
+#define nfserr_badsession		cpu_to_be32(NFS4ERR_BADSESSION)
+#define nfserr_badslot			cpu_to_be32(NFS4ERR_BADSLOT)
+#define nfserr_complete_already		cpu_to_be32(NFS4ERR_COMPLETE_ALREADY)
+#define nfserr_conn_not_bound_to_session cpu_to_be32(NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
+#define nfserr_deleg_already_wanted	cpu_to_be32(NFS4ERR_DELEG_ALREADY_WANTED)
+#define nfserr_back_chan_busy		cpu_to_be32(NFS4ERR_BACK_CHAN_BUSY)
+#define nfserr_layouttrylater		cpu_to_be32(NFS4ERR_LAYOUTTRYLATER)
+#define nfserr_layoutunavailable	cpu_to_be32(NFS4ERR_LAYOUTUNAVAILABLE)
+#define nfserr_nomatching_layout	cpu_to_be32(NFS4ERR_NOMATCHING_LAYOUT)
+#define nfserr_recallconflict		cpu_to_be32(NFS4ERR_RECALLCONFLICT)
+#define nfserr_unknown_layouttype	cpu_to_be32(NFS4ERR_UNKNOWN_LAYOUTTYPE)
+#define nfserr_seq_misordered		cpu_to_be32(NFS4ERR_SEQ_MISORDERED)
+#define nfserr_sequence_pos		cpu_to_be32(NFS4ERR_SEQUENCE_POS)
+#define nfserr_req_too_big		cpu_to_be32(NFS4ERR_REQ_TOO_BIG)
+#define nfserr_rep_too_big		cpu_to_be32(NFS4ERR_REP_TOO_BIG)
+#define nfserr_rep_too_big_to_cache	cpu_to_be32(NFS4ERR_REP_TOO_BIG_TO_CACHE)
+#define nfserr_retry_uncached_rep	cpu_to_be32(NFS4ERR_RETRY_UNCACHED_REP)
+#define nfserr_unsafe_compound		cpu_to_be32(NFS4ERR_UNSAFE_COMPOUND)
+#define nfserr_too_many_ops		cpu_to_be32(NFS4ERR_TOO_MANY_OPS)
+#define nfserr_op_not_in_session	cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION)
+#define nfserr_hash_alg_unsupp		cpu_to_be32(NFS4ERR_HASH_ALG_UNSUPP)
+#define nfserr_clientid_busy		cpu_to_be32(NFS4ERR_CLIENTID_BUSY)
+#define nfserr_pnfs_io_hole		cpu_to_be32(NFS4ERR_PNFS_IO_HOLE)
+#define nfserr_seq_false_retry		cpu_to_be32(NFS4ERR_SEQ_FALSE_RETRY)
+#define nfserr_bad_high_slot		cpu_to_be32(NFS4ERR_BAD_HIGH_SLOT)
+#define nfserr_deadsession		cpu_to_be32(NFS4ERR_DEADSESSION)
+#define nfserr_encr_alg_unsupp		cpu_to_be32(NFS4ERR_ENCR_ALG_UNSUPP)
+#define nfserr_pnfs_no_layout		cpu_to_be32(NFS4ERR_PNFS_NO_LAYOUT)
+#define nfserr_not_only_op		cpu_to_be32(NFS4ERR_NOT_ONLY_OP)
+#define nfserr_wrong_cred		cpu_to_be32(NFS4ERR_WRONG_CRED)
+#define nfserr_wrong_type		cpu_to_be32(NFS4ERR_WRONG_TYPE)
+#define nfserr_dirdeleg_unavail		cpu_to_be32(NFS4ERR_DIRDELEG_UNAVAIL)
+#define nfserr_reject_deleg		cpu_to_be32(NFS4ERR_REJECT_DELEG)
+#define nfserr_returnconflict		cpu_to_be32(NFS4ERR_RETURNCONFLICT)
+#define nfserr_deleg_revoked		cpu_to_be32(NFS4ERR_DELEG_REVOKED)
+#define nfserr_partner_notsupp		cpu_to_be32(NFS4ERR_PARTNER_NOTSUPP)
+#define nfserr_partner_no_auth		cpu_to_be32(NFS4ERR_PARTNER_NO_AUTH)
+#define nfserr_union_notsupp		cpu_to_be32(NFS4ERR_UNION_NOTSUPP)
+#define nfserr_offload_denied		cpu_to_be32(NFS4ERR_OFFLOAD_DENIED)
+#define nfserr_wrong_lfs		cpu_to_be32(NFS4ERR_WRONG_LFS)
+#define nfserr_badlabel			cpu_to_be32(NFS4ERR_BADLABEL)
+#define nfserr_file_open		cpu_to_be32(NFS4ERR_FILE_OPEN)
+#define nfserr_xattr2big		cpu_to_be32(NFS4ERR_XATTR2BIG)
+#define nfserr_noxattr			cpu_to_be32(NFS4ERR_NOXATTR)
+
+/*
+ * Error codes for internal use.  These are based at an impossible
+ * nfsstat4 value so that, once converted to be32, they cannot conflict
+ * with any value defined by the protocol (compare the nlm__int__* codes
+ * in fs/lockd/lockd.h).
+ */
+enum {
+/* end-of-file indicator in readdir */
+	NFSERR_EOF = 30000,
+#define	nfserr_eof		cpu_to_be32(NFSERR_EOF)
+
+/* replay detected */
+	NFSERR_REPLAY_ME,
+#define	nfserr_replay_me	cpu_to_be32(NFSERR_REPLAY_ME)
+
+/* nfs41 replay detected */
+	NFSERR_REPLAY_CACHE,
+#define	nfserr_replay_cache	cpu_to_be32(NFSERR_REPLAY_CACHE)
+
+/* symlink found where dir expected - handled differently to
+ * other symlink found errors by NFSv3.
+ */
+	NFSERR_SYMLINK_NOT_DIR,
+#define	nfserr_symlink_not_dir	cpu_to_be32(NFSERR_SYMLINK_NOT_DIR)
+};
+
+#ifdef CONFIG_NFSD_V4
+
+/* before processing a COMPOUND operation, we have to check that there
+ * is enough space in the buffer for XDR encode to succeed.  otherwise,
+ * we might process an operation with side effects, and be unable to
+ * tell the client that the operation succeeded.
+ *
+ * COMPOUND_SLACK_SPACE - this is the minimum bytes of buffer space
+ * needed to encode an "ordinary" _successful_ operation.  (GETATTR,
+ * READ, READDIR, and READLINK have their own buffer checks.)  if we
+ * fall below this level, we fail the next operation with NFS4ERR_RESOURCE.
+ *
+ * COMPOUND_ERR_SLACK_SPACE - this is the minimum bytes of buffer space
+ * needed to encode an operation which has failed with NFS4ERR_RESOURCE.
+ * care is taken to ensure that we never fall below this level for any
+ * reason.
+ */
+#define	COMPOUND_SLACK_SPACE		140    /* OP_GETFH */
+#define COMPOUND_ERR_SLACK_SPACE	16     /* OP_SETATTR */
+
+#define NFSD_LAUNDROMAT_MINTIMEOUT      1   /* seconds */
+#define	NFSD_COURTESY_CLIENT_TIMEOUT	(24 * 60 * 60)	/* seconds */
+#define	NFSD_CLIENT_MAX_TRIM_PER_RUN	128
+#define	NFS4_CLIENTS_PER_GB		1024
+#define NFSD_DELEGRETURN_TIMEOUT	(HZ / 34)	/* 30ms */
+#define	NFSD_CB_GETATTR_TIMEOUT		NFSD_DELEGRETURN_TIMEOUT
+
+extern int nfsd4_is_junction(struct dentry *dentry);
+extern int register_cld_notifier(void);
+extern void unregister_cld_notifier(void);
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn);
+#endif
+
+extern void nfsd4_init_leases_net(struct nfsd_net *nn);
+
+#else /* CONFIG_NFSD_V4 */
+static inline int nfsd4_is_junction(struct dentry *dentry)
+{
+	return 0;
+}
+
+static inline void nfsd4_init_leases_net(struct nfsd_net *nn) { };
+
+#define register_cld_notifier() 0
+#define unregister_cld_notifier() do { } while(0)
+
+#endif /* CONFIG_NFSD_V4 */
+
+#endif /* LINUX_NFSD_NFSD_H */
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
new file mode 100644
index 000000000..c7c60c35b
--- /dev/null
+++ b/fs/nfsd/nfsfh.c
@@ -0,0 +1,972 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NFS server file handle treatment.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
+ * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
+ * ... and again Southern-Winter 2001 to support export_operations
+ */
+
+#include <linux/exportfs.h>
+
+#include <linux/sunrpc/svcauth_gss.h>
+#include <crypto/utils.h>
+#include "nfsd.h"
+#include "netns.h"
+#include "stats.h"
+#include "vfs.h"
+#include "auth.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_FH
+
+
+/*
+ * our acceptability function.
+ * if NOSUBTREECHECK, accept anything
+ * if not, require that we can walk up to exp->ex_dentry
+ * doing some checks on the 'x' bits
+ */
+static int nfsd_acceptable(void *expv, struct dentry *dentry)
+{
+	struct svc_export *exp = expv;
+	int rv;
+	struct dentry *tdentry;
+	struct dentry *parent;
+
+	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
+		return 1;
+
+	tdentry = dget(dentry);
+	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
+		/* make sure parents give x permission to user */
+		int err;
+		parent = dget_parent(tdentry);
+		err = inode_permission(&nop_mnt_idmap,
+				       d_inode(parent), MAY_EXEC);
+		if (err < 0) {
+			dput(parent);
+			break;
+		}
+		dput(tdentry);
+		tdentry = parent;
+	}
+	if (tdentry != exp->ex_path.dentry)
+		dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
+	rv = (tdentry == exp->ex_path.dentry);
+	dput(tdentry);
+	return rv;
+}
+
+/* Type check. The correct error return for type mismatches does not seem to be
+ * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
+ * comment in the NFSv3 spec says this is incorrect (implementation notes for
+ * the write call).
+ */
+static inline __be32
+nfsd_mode_check(struct dentry *dentry, umode_t requested)
+{
+	umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
+
+	if (requested == 0) /* the caller doesn't care */
+		return nfs_ok;
+	if (mode == requested) {
+		if (mode == S_IFDIR && !d_can_lookup(dentry))
+			return nfserr_notdir;
+		return nfs_ok;
+	}
+	if (mode == S_IFLNK) {
+		if (requested == S_IFDIR)
+			return nfserr_symlink_not_dir;
+		return nfserr_symlink;
+	}
+	if (requested == S_IFDIR)
+		return nfserr_notdir;
+	if (mode == S_IFDIR)
+		return nfserr_isdir;
+	return nfserr_wrong_type;
+}
+
+static bool nfsd_originating_port_ok(struct svc_rqst *rqstp,
+				     struct svc_cred *cred,
+				     struct svc_export *exp)
+{
+	if (nfsexp_flags(cred, exp) & NFSEXP_INSECURE_PORT)
+		return true;
+	/* We don't require gss requests to use low ports: */
+	if (cred->cr_flavor >= RPC_AUTH_GSS)
+		return true;
+	return test_bit(RQ_SECURE, &rqstp->rq_flags);
+}
+
+static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
+					  struct svc_cred *cred,
+					  struct svc_export *exp)
+{
+	/* Check if the request originated from a secure port. */
+	if (rqstp && !nfsd_originating_port_ok(rqstp, cred, exp)) {
+		if (IS_ENABLED(CONFIG_SUNRPC_DEBUG)) {
+			char buf[RPC_MAX_ADDRBUFLEN];
+
+			dprintk("nfsd: request from insecure port %s!\n",
+			        svc_print_addr(rqstp, buf, sizeof(buf)));
+		}
+		return nfserr_perm;
+	}
+
+	/* Set user creds for this exportpoint */
+	return nfserrno(nfsd_setuser(cred, exp));
+}
+
+static inline __be32 check_pseudo_root(struct dentry *dentry,
+				       struct svc_export *exp)
+{
+	if (!(exp->ex_flags & NFSEXP_V4ROOT))
+		return nfs_ok;
+	/*
+	 * We're exposing only the directories and symlinks that have to be
+	 * traversed on the way to real exports:
+	 */
+	if (unlikely(!d_is_dir(dentry) &&
+		     !d_is_symlink(dentry)))
+		return nfserr_stale;
+	/*
+	 * A pseudoroot export gives permission to access only one
+	 * single directory; the kernel has to make another upcall
+	 * before granting access to anything else under it:
+	 */
+	if (unlikely(dentry != exp->ex_path.dentry))
+		return nfserr_stale;
+	return nfs_ok;
+}
+
+/* Size of a file handle MAC, in 4-octet words */
+#define FH_MAC_WORDS (sizeof(__le64) / 4)
+
+bool fh_append_mac(struct knfsd_fh *fh, int fh_maxsize, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	siphash_key_t *fh_key = nn->fh_key;
+	__le64 hash;
+
+	if (!fh_key)
+		goto out_no_key;
+	if (fh->fh_size + sizeof(hash) > fh_maxsize)
+		goto out_no_space;
+
+	hash = cpu_to_le64(siphash(&fh->fh_raw, fh->fh_size, fh_key));
+	memcpy(&fh->fh_raw[fh->fh_size], &hash, sizeof(hash));
+	fh->fh_size += sizeof(hash);
+	return true;
+
+out_no_key:
+	pr_warn_ratelimited("NFSD: unable to sign filehandles, fh_key not set.\n");
+	return false;
+
+out_no_space:
+	pr_warn_ratelimited("NFSD: unable to sign filehandles, fh_size %zu would be greater than fh_maxsize %d.\n",
+			    fh->fh_size + sizeof(hash), fh_maxsize);
+	return false;
+}
+
+/*
+ * Verify that the filehandle's MAC was hashed from this filehandle
+ * given the server's fh_key:
+ */
+static bool fh_verify_mac(struct svc_fh *fhp, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct knfsd_fh *fh = &fhp->fh_handle;
+	siphash_key_t *fh_key = nn->fh_key;
+	__le64 hash;
+
+	if (!fh_key) {
+		pr_warn_ratelimited("NFSD: unable to verify signed filehandles, fh_key not set.\n");
+		return false;
+	}
+
+	hash = cpu_to_le64(siphash(&fh->fh_raw, fh->fh_size - sizeof(hash),  fh_key));
+	return crypto_memneq(&fh->fh_raw[fh->fh_size - sizeof(hash)],
+					&hash, sizeof(hash)) == 0;
+}
+
+/*
+ * Use the given filehandle to look up the corresponding export and
+ * dentry.  On success, the results are used to set fh_export and
+ * fh_dentry.
+ */
+static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct net *net,
+				 struct svc_cred *cred,
+				 struct auth_domain *client,
+				 struct auth_domain *gssclient,
+				 struct svc_fh *fhp)
+{
+	struct knfsd_fh	*fh = &fhp->fh_handle;
+	struct fid *fid = NULL;
+	struct svc_export *exp;
+	struct dentry *dentry;
+	int fileid_type;
+	int data_left = fh->fh_size/4;
+	int len;
+	__be32 error;
+
+	error = nfserr_badhandle;
+	if (fh->fh_size == 0)
+		return nfserr_nofilehandle;
+
+	if (fh->fh_version != 1)
+		return error;
+
+	if (--data_left < 0)
+		return error;
+	if (fh->fh_auth_type != 0)
+		return error;
+	len = key_len(fh->fh_fsid_type) / 4;
+	if (len == 0)
+		return error;
+	if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
+		u32 *fsid = fh_fsid(fh);
+
+		/* deprecated, convert to type 3 */
+		len = key_len(FSID_ENCODE_DEV)/4;
+		fh->fh_fsid_type = FSID_ENCODE_DEV;
+		/*
+		 * struct knfsd_fh uses host-endian fields, which are
+		 * sometimes used to hold net-endian values. This
+		 * confuses sparse, so we must use __force here to
+		 * keep it from complaining.
+		 */
+		fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fsid[0]),
+					       ntohl((__force __be32)fsid[1])));
+		fsid[1] = fsid[2];
+	}
+	data_left -= len;
+	if (data_left < 0)
+		return error;
+	exp = rqst_exp_find(rqstp ? &rqstp->rq_chandle : NULL,
+			    net, client, gssclient,
+			    fh->fh_fsid_type, fh_fsid(fh));
+	fid = (struct fid *)(fh_fsid(fh) + len);
+
+	error = nfserr_stale;
+	if (IS_ERR(exp)) {
+		trace_nfsd_set_fh_dentry_badexport(rqstp, fhp, PTR_ERR(exp));
+
+		if (PTR_ERR(exp) == -ENOENT)
+			return error;
+
+		return nfserrno(PTR_ERR(exp));
+	}
+
+	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
+		/* Elevate privileges so that the lack of 'r' or 'x'
+		 * permission on some parent directory will
+		 * not stop exportfs_decode_fh from being able
+		 * to reconnect a directory into the dentry cache.
+		 * The same problem can affect "SUBTREECHECK" exports,
+		 * but as nfsd_acceptable depends on correct
+		 * access control settings being in effect, we cannot
+		 * fix that case easily.
+		 */
+		struct cred *new = prepare_creds();
+		if (!new) {
+			error =  nfserrno(-ENOMEM);
+			goto out;
+		}
+		new->cap_effective =
+			cap_raise_nfsd_set(new->cap_effective,
+					   new->cap_permitted);
+		put_cred(override_creds(new));
+	} else {
+		error = nfsd_setuser_and_check_port(rqstp, cred, exp);
+		if (error)
+			goto out;
+	}
+
+	/*
+	 * Look up the dentry using the NFS file handle.
+	 */
+	fileid_type = fh->fh_fileid_type;
+	error = nfserr_stale;
+
+	if (fileid_type == FILEID_ROOT) {
+		/* We don't sign or verify the root, no per-file identity */
+		dentry = dget(exp->ex_path.dentry);
+	} else {
+		if (exp->ex_flags & NFSEXP_SIGN_FH) {
+			if (!fh_verify_mac(fhp, net)) {
+				trace_nfsd_set_fh_dentry_badmac(rqstp, fhp, -ESTALE);
+				goto out;
+			}
+			data_left -= FH_MAC_WORDS;
+		}
+
+		dentry = exportfs_decode_fh_raw(exp->ex_path.mnt, fid,
+						data_left, fileid_type, 0,
+						nfsd_acceptable, exp);
+		if (IS_ERR_OR_NULL(dentry)) {
+			trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
+					dentry ?  PTR_ERR(dentry) : -ESTALE);
+			switch (PTR_ERR(dentry)) {
+			case -ENOMEM:
+			case -ETIMEDOUT:
+				break;
+			default:
+				dentry = ERR_PTR(-ESTALE);
+			}
+		}
+	}
+
+	error = nfserr_badhandle;
+	if (dentry == NULL)
+		goto out;
+	if (IS_ERR(dentry)) {
+		if (PTR_ERR(dentry) != -EINVAL)
+			error = nfserrno(PTR_ERR(dentry));
+		goto out;
+	}
+
+	if (d_is_dir(dentry) &&
+			(dentry->d_flags & DCACHE_DISCONNECTED)) {
+		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
+				dentry);
+	}
+
+	switch (fhp->fh_maxsize) {
+	case NFS4_FHSIZE:
+		if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOATOMIC_ATTR)
+			fhp->fh_no_atomic_attr = true;
+		fhp->fh_64bit_cookies = true;
+		break;
+	case NFS3_FHSIZE:
+		if (dentry->d_sb->s_export_op->flags & EXPORT_OP_NOWCC)
+			fhp->fh_no_wcc = true;
+		fhp->fh_64bit_cookies = true;
+		if (exp->ex_flags & NFSEXP_V4ROOT) {
+			dput(dentry);
+			goto out;
+		}
+		break;
+	case NFS_FHSIZE:
+		fhp->fh_no_wcc = true;
+		if (EX_WGATHER(exp))
+			fhp->fh_use_wgather = true;
+		if (exp->ex_flags & NFSEXP_V4ROOT) {
+			dput(dentry);
+			goto out;
+		}
+	}
+
+	fhp->fh_dentry = dentry;
+	fhp->fh_export = exp;
+
+	return 0;
+out:
+	exp_put(exp);
+	return error;
+}
+
+/**
+ * __fh_verify - filehandle lookup and access checking
+ * @rqstp: RPC transaction context, or NULL
+ * @net: net namespace in which to perform the export lookup
+ * @cred: RPC user credential
+ * @client: RPC auth domain
+ * @gssclient: RPC GSS auth domain, or NULL
+ * @fhp: filehandle to be verified
+ * @type: expected type of object pointed to by filehandle
+ * @access: type of access needed to object
+ *
+ * See fh_verify() for further descriptions of @fhp, @type, and @access.
+ */
+static __be32
+__fh_verify(struct svc_rqst *rqstp,
+	    struct net *net, struct svc_cred *cred,
+	    struct auth_domain *client,
+	    struct auth_domain *gssclient,
+	    struct svc_fh *fhp, umode_t type, int access)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_export *exp = NULL;
+	bool may_bypass_gss = false;
+	struct dentry	*dentry;
+	__be32		error;
+
+	if (!fhp->fh_dentry) {
+		error = nfsd_set_fh_dentry(rqstp, net, cred, client,
+					   gssclient, fhp);
+		if (error)
+			goto out;
+	}
+	dentry = fhp->fh_dentry;
+	exp = fhp->fh_export;
+
+	trace_nfsd_fh_verify(rqstp, fhp, type, access);
+
+	/*
+	 * We still have to do all these permission checks, even when
+	 * fh_dentry is already set:
+	 * 	- fh_verify may be called multiple times with different
+	 * 	  "access" arguments (e.g. nfsd_proc_create calls
+	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
+	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
+	 *	- in the NFSv4 case, the filehandle may have been filled
+	 *	  in by fh_compose, and given a dentry, but further
+	 *	  compound operations performed with that filehandle
+	 *	  still need permissions checks.  In the worst case, a
+	 *	  mountpoint crossing may have changed the export
+	 *	  options, and we may now need to use a different uid
+	 *	  (for example, if different id-squashing options are in
+	 *	  effect on the new filesystem).
+	 */
+	error = check_pseudo_root(dentry, exp);
+	if (error)
+		goto out;
+
+	error = nfsd_setuser_and_check_port(rqstp, cred, exp);
+	if (error)
+		goto out;
+
+	error = nfsd_mode_check(dentry, type);
+	if (error)
+		goto out;
+
+	/*
+	 * If rqstp is NULL, this is a LOCALIO request which will only
+	 * ever use a filehandle/credential pair for which access has
+	 * been affirmed (by ACCESS or OPEN NFS requests) over the
+	 * wire.  Skip both the xprtsec policy and the security flavor
+	 * checks.
+	 */
+	if (!rqstp)
+		goto check_permissions;
+
+	if ((access & NFSD_MAY_NLM) && (exp->ex_flags & NFSEXP_NOAUTHNLM))
+		/* NLM is allowed to fully bypass authentication */
+		goto out;
+
+	/*
+	 * NLM is allowed to bypass the xprtsec policy check because lockd
+	 * doesn't support xprtsec.
+	 */
+	if (!(access & NFSD_MAY_NLM)) {
+		error = check_xprtsec_policy(exp, rqstp);
+		if (error)
+			goto out;
+	}
+
+	if (access & NFSD_MAY_BYPASS_GSS)
+		may_bypass_gss = true;
+	/*
+	 * Clients may expect to be able to use auth_sys during mount,
+	 * even if they use gss for everything else; see section 2.3.2
+	 * of rfc 2623.
+	 */
+	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
+			&& exp->ex_path.dentry == dentry)
+		may_bypass_gss = true;
+
+	error = check_security_flavor(exp, rqstp, may_bypass_gss);
+	if (error)
+		goto out;
+
+	svc_xprt_set_valid(rqstp->rq_xprt);
+
+check_permissions:
+	/* Finally, check access permissions. */
+	error = nfsd_permission(cred, exp, dentry, access);
+out:
+	trace_nfsd_fh_verify_err(rqstp, fhp, type, access, error);
+	if (error == nfserr_stale)
+		nfsd_stats_fh_stale_inc(nn, exp);
+	return error;
+}
+
+/**
+ * fh_verify_local - filehandle lookup and access checking
+ * @net: net namespace in which to perform the export lookup
+ * @cred: RPC user credential
+ * @client: RPC auth domain
+ * @fhp: filehandle to be verified
+ * @type: expected type of object pointed to by filehandle
+ * @access: type of access needed to object
+ *
+ * This API can be used by callers who do not have an RPC
+ * transaction context (ie are not running in an nfsd thread).
+ *
+ * See fh_verify() for further descriptions of @fhp, @type, and @access.
+ */
+__be32
+fh_verify_local(struct net *net, struct svc_cred *cred,
+		struct auth_domain *client, struct svc_fh *fhp,
+		umode_t type, int access)
+{
+	return __fh_verify(NULL, net, cred, client, NULL,
+			   fhp, type, access);
+}
+
+/**
+ * fh_verify - filehandle lookup and access checking
+ * @rqstp: pointer to current rpc request
+ * @fhp: filehandle to be verified
+ * @type: expected type of object pointed to by filehandle
+ * @access: type of access needed to object
+ *
+ * Look up a dentry from the on-the-wire filehandle, check the client's
+ * access to the export, and set the current task's credentials.
+ *
+ * Regardless of success or failure of fh_verify(), fh_put() should be
+ * called on @fhp when the caller is finished with the filehandle.
+ *
+ * fh_verify() may be called multiple times on a given filehandle, for
+ * example, when processing an NFSv4 compound.  The first call will look
+ * up a dentry using the on-the-wire filehandle.  Subsequent calls will
+ * skip the lookup and just perform the other checks and possibly change
+ * the current task's credentials.
+ *
+ * @type specifies the type of object expected using one of the S_IF*
+ * constants defined in include/linux/stat.h.  The caller may use zero
+ * to indicate that it doesn't care, or a negative integer to indicate
+ * that it expects something not of the given type.
+ *
+ * @access is formed from the NFSD_MAY_* constants defined in
+ * fs/nfsd/vfs.h.
+ */
+__be32
+fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
+{
+	return __fh_verify(rqstp, SVC_NET(rqstp), &rqstp->rq_cred,
+			   rqstp->rq_client, rqstp->rq_gssclient,
+			   fhp, type, access);
+}
+
+/*
+ * Compose a file handle for an NFS reply.
+ *
+ * Note that when first composed, the dentry may not yet have
+ * an inode.  In this case a call to fh_update should be made
+ * before the fh goes out on the wire ...
+ */
+static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
+		struct dentry *dentry)
+{
+	if (dentry != exp->ex_path.dentry) {
+		struct fid *fid = (struct fid *)
+			(fh_fsid(&fhp->fh_handle) + fhp->fh_handle.fh_size/4 - 1);
+		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
+		int fh_flags = (exp->ex_flags & NFSEXP_NOSUBTREECHECK) ? 0 :
+				EXPORT_FH_CONNECTABLE;
+		int fileid_type =
+			exportfs_encode_fh(dentry, fid, &maxsize, fh_flags);
+
+		fhp->fh_handle.fh_fileid_type =
+			fileid_type > 0 ? fileid_type : FILEID_INVALID;
+		fhp->fh_handle.fh_size += maxsize * 4;
+
+		if (exp->ex_flags & NFSEXP_SIGN_FH)
+			if (!fh_append_mac(&fhp->fh_handle, fhp->fh_maxsize,
+					   exp->cd->net))
+				fhp->fh_handle.fh_fileid_type = FILEID_INVALID;
+	} else {
+		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
+	}
+}
+
+static bool is_root_export(struct svc_export *exp)
+{
+	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
+}
+
+static struct super_block *exp_sb(struct svc_export *exp)
+{
+	return exp->ex_path.dentry->d_sb;
+}
+
+static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
+{
+	switch (fsid_type) {
+	case FSID_DEV:
+		if (!old_valid_dev(exp_sb(exp)->s_dev))
+			return false;
+		fallthrough;
+	case FSID_MAJOR_MINOR:
+	case FSID_ENCODE_DEV:
+		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
+	case FSID_NUM:
+		return exp->ex_flags & NFSEXP_FSID;
+	case FSID_UUID8:
+	case FSID_UUID16:
+		if (!is_root_export(exp))
+			return false;
+		fallthrough;
+	case FSID_UUID4_INUM:
+	case FSID_UUID16_INUM:
+		return exp->ex_uuid != NULL;
+	}
+	return true;
+}
+
+
+static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
+{
+	u8 version;
+	u8 fsid_type;
+retry:
+	version = 1;
+	if (ref_fh && ref_fh->fh_export == exp) {
+		version = ref_fh->fh_handle.fh_version;
+		fsid_type = ref_fh->fh_handle.fh_fsid_type;
+
+		ref_fh = NULL;
+
+		switch (version) {
+		case 0xca:
+			fsid_type = FSID_DEV;
+			break;
+		case 1:
+			break;
+		default:
+			goto retry;
+		}
+
+		/*
+		 * As the fsid -> filesystem mapping was guided by
+		 * user-space, there is no guarantee that the filesystem
+		 * actually supports that fsid type. If it doesn't we
+		 * loop around again without ref_fh set.
+		 */
+		if (!fsid_type_ok_for_exp(fsid_type, exp))
+			goto retry;
+	} else if (exp->ex_flags & NFSEXP_FSID) {
+		fsid_type = FSID_NUM;
+	} else if (exp->ex_uuid) {
+		if (fhp->fh_maxsize >= 64) {
+			if (is_root_export(exp))
+				fsid_type = FSID_UUID16;
+			else
+				fsid_type = FSID_UUID16_INUM;
+		} else {
+			if (is_root_export(exp))
+				fsid_type = FSID_UUID8;
+			else
+				fsid_type = FSID_UUID4_INUM;
+		}
+	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
+		/* for newer device numbers, we must use a newer fsid format */
+		fsid_type = FSID_ENCODE_DEV;
+	else
+		fsid_type = FSID_DEV;
+	fhp->fh_handle.fh_version = version;
+	if (version)
+		fhp->fh_handle.fh_fsid_type = fsid_type;
+}
+
+__be32
+fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
+	   struct svc_fh *ref_fh)
+{
+	/* ref_fh is a reference file handle.
+	 * if it is non-null and for the same filesystem, then we should compose
+	 * a filehandle which is of the same version, where possible.
+	 */
+
+	struct inode * inode = d_inode(dentry);
+	dev_t ex_dev = exp_sb(exp)->s_dev;
+
+	dprintk("nfsd: fh_compose(exp %02x:%02x/%llu %pd2, ino=%llu)\n",
+		MAJOR(ex_dev), MINOR(ex_dev),
+		d_inode(exp->ex_path.dentry)->i_ino,
+		dentry,
+		(inode ? inode->i_ino : 0));
+
+	/* Choose filehandle version and fsid type based on
+	 * the reference filehandle (if it is in the same export)
+	 * or the export options.
+	 */
+	set_version_and_fsid_type(fhp, exp, ref_fh);
+
+	/* If we have a ref_fh, then copy the fh_no_wcc setting from it. */
+	fhp->fh_no_wcc = ref_fh ? ref_fh->fh_no_wcc : false;
+
+	if (ref_fh == fhp)
+		fh_put(ref_fh);
+
+	if (fhp->fh_dentry) {
+		printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
+		       dentry);
+	}
+	if (fhp->fh_maxsize < NFS_FHSIZE)
+		printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
+		       fhp->fh_maxsize,
+		       dentry);
+
+	fhp->fh_dentry = dget(dentry); /* our internal copy */
+	fhp->fh_export = exp_get(exp);
+
+	fhp->fh_handle.fh_size =
+		key_len(fhp->fh_handle.fh_fsid_type) + 4;
+	fhp->fh_handle.fh_auth_type = 0;
+
+	mk_fsid(fhp->fh_handle.fh_fsid_type,
+		fh_fsid(&fhp->fh_handle),
+		ex_dev,
+		d_inode(exp->ex_path.dentry)->i_ino,
+		exp->ex_fsid, exp->ex_uuid);
+
+	if (inode)
+		_fh_update(fhp, exp, dentry);
+	if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
+		fh_put(fhp);
+		return nfserr_stale;
+	}
+
+	return 0;
+}
+
+/*
+ * Update file handle information after changing a dentry.
+ * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
+ */
+__be32
+fh_update(struct svc_fh *fhp)
+{
+	struct dentry *dentry;
+
+	if (!fhp->fh_dentry)
+		goto out_bad;
+
+	dentry = fhp->fh_dentry;
+	if (d_really_is_negative(dentry))
+		goto out_negative;
+	if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
+		return 0;
+
+	_fh_update(fhp, fhp->fh_export, dentry);
+	if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
+		return nfserr_stale;
+	return 0;
+out_bad:
+	printk(KERN_ERR "fh_update: fh not verified!\n");
+	return nfserr_serverfault;
+out_negative:
+	printk(KERN_ERR "fh_update: %pd2 still negative!\n",
+		dentry);
+	return nfserr_serverfault;
+}
+
+/**
+ * fh_getattr - Retrieve attributes on a local file
+ * @fhp: File handle of target file
+ * @stat: Caller-supplied kstat buffer to be filled in
+ *
+ * Returns nfs_ok on success, otherwise an NFS status code is
+ * returned.
+ */
+__be32 fh_getattr(const struct svc_fh *fhp, struct kstat *stat)
+{
+	struct path p = {
+		.mnt		= fhp->fh_export->ex_path.mnt,
+		.dentry		= fhp->fh_dentry,
+	};
+	struct inode *inode = d_inode(p.dentry);
+	u32 request_mask = STATX_BASIC_STATS;
+
+	if (S_ISREG(inode->i_mode))
+		request_mask |= (STATX_DIOALIGN | STATX_DIO_READ_ALIGN);
+
+	if (fhp->fh_maxsize == NFS4_FHSIZE)
+		request_mask |= (STATX_BTIME | STATX_CHANGE_COOKIE);
+
+	return nfserrno(vfs_getattr(&p, stat, request_mask,
+				    AT_STATX_SYNC_AS_STAT));
+}
+
+/**
+ * fh_fill_pre_attrs - Fill in pre-op attributes
+ * @fhp: file handle to be updated
+ *
+ */
+__be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp)
+{
+	bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
+	struct kstat stat;
+	__be32 err;
+
+	if (fhp->fh_no_wcc || fhp->fh_pre_saved)
+		return nfs_ok;
+
+	err = fh_getattr(fhp, &stat);
+	if (err)
+		return err;
+
+	if (v4)
+		fhp->fh_pre_change = nfsd4_change_attribute(&stat);
+
+	fhp->fh_pre_mtime = stat.mtime;
+	fhp->fh_pre_ctime = stat.ctime;
+	fhp->fh_pre_size  = stat.size;
+	fhp->fh_pre_saved = true;
+	return nfs_ok;
+}
+
+/**
+ * fh_fill_post_attrs - Fill in post-op attributes
+ * @fhp: file handle to be updated
+ *
+ */
+__be32 fh_fill_post_attrs(struct svc_fh *fhp)
+{
+	bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
+	__be32 err;
+
+	if (fhp->fh_no_wcc)
+		return nfs_ok;
+
+	if (fhp->fh_post_saved)
+		printk("nfsd: inode locked twice during operation.\n");
+
+	err = fh_getattr(fhp, &fhp->fh_post_attr);
+	if (err)
+		return err;
+
+	fhp->fh_post_saved = true;
+	if (v4)
+		fhp->fh_post_change =
+			nfsd4_change_attribute(&fhp->fh_post_attr);
+	return nfs_ok;
+}
+
+/**
+ * fh_fill_both_attrs - Fill pre-op and post-op attributes
+ * @fhp: file handle to be updated
+ *
+ * This is used when the directory wasn't changed, but wcc attributes
+ * are needed anyway.
+ */
+__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp)
+{
+	__be32 err;
+
+	err = fh_fill_post_attrs(fhp);
+	if (err)
+		return err;
+
+	fhp->fh_pre_change = fhp->fh_post_change;
+	fhp->fh_pre_mtime = fhp->fh_post_attr.mtime;
+	fhp->fh_pre_ctime = fhp->fh_post_attr.ctime;
+	fhp->fh_pre_size = fhp->fh_post_attr.size;
+	fhp->fh_pre_saved = true;
+	return nfs_ok;
+}
+
+/*
+ * Release a file handle.
+ */
+void
+fh_put(struct svc_fh *fhp)
+{
+	struct dentry * dentry = fhp->fh_dentry;
+	struct svc_export * exp = fhp->fh_export;
+	if (dentry) {
+		fhp->fh_dentry = NULL;
+		dput(dentry);
+		fh_clear_pre_post_attrs(fhp);
+	}
+	fh_drop_write(fhp);
+	if (exp) {
+		exp_put(exp);
+		fhp->fh_export = NULL;
+	}
+	fhp->fh_no_wcc = false;
+	return;
+}
+
+/*
+ * Shorthand for dprintk()'s
+ */
+char * SVCFH_fmt(struct svc_fh *fhp)
+{
+	struct knfsd_fh *fh = &fhp->fh_handle;
+	static char buf[2+1+1+64*3+1];
+
+	if (fh->fh_size > 64)
+		return "bad-fh";
+	sprintf(buf, "%d: %*ph", fh->fh_size, fh->fh_size, fh->fh_raw);
+	return buf;
+}
+
+enum fsid_source fsid_source_fh(const struct knfsd_fh *fh,
+				struct svc_export *exp)
+{
+	if (fh->fh_version != 1)
+		return FSIDSOURCE_DEV;
+	switch (fh->fh_fsid_type) {
+	case FSID_DEV:
+	case FSID_ENCODE_DEV:
+	case FSID_MAJOR_MINOR:
+		if (exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV)
+			return FSIDSOURCE_DEV;
+		break;
+	case FSID_NUM:
+		if (exp->ex_flags & NFSEXP_FSID)
+			return FSIDSOURCE_FSID;
+		break;
+	default:
+		break;
+	}
+	/* either a UUID type filehandle, or the filehandle doesn't
+	 * match the export.
+	 */
+	if (exp->ex_flags & NFSEXP_FSID)
+		return FSIDSOURCE_FSID;
+	if (exp->ex_uuid)
+		return FSIDSOURCE_UUID;
+	return FSIDSOURCE_DEV;
+}
+
+enum fsid_source fsid_source(const struct svc_fh *fhp)
+{
+	return fsid_source_fh(&fhp->fh_handle, fhp->fh_export);
+}
+
+/**
+ * nfsd4_change_attribute - Generate an NFSv4 change_attribute value
+ * @stat: inode attributes
+ *
+ * Caller must fill in @stat before calling, typically by invoking
+ * vfs_getattr() with STATX_MODE, STATX_CTIME, and STATX_CHANGE_COOKIE.
+ * Returns an unsigned 64-bit changeid4 value (RFC 8881 Section 3.2).
+ *
+ * We could use i_version alone as the change attribute.  However, i_version
+ * can go backwards on a regular file after an unclean shutdown.  On its own
+ * that doesn't necessarily cause a problem, but if i_version goes backwards
+ * and then is incremented again it could reuse a value that was previously
+ * used before boot, and a client who queried the two values might incorrectly
+ * assume nothing changed.
+ *
+ * By using both ctime and the i_version counter we guarantee that as long as
+ * time doesn't go backwards we never reuse an old value. If the filesystem
+ * advertises STATX_ATTR_CHANGE_MONOTONIC, then this mitigation is not
+ * needed.
+ *
+ * We only need to do this for regular files as well. For directories, we
+ * assume that the new change attr is always logged to stable storage in some
+ * fashion before the results can be seen.
+ */
+u64 nfsd4_change_attribute(const struct kstat *stat)
+{
+	u64 chattr;
+
+	if (stat->result_mask & STATX_CHANGE_COOKIE) {
+		chattr = stat->change_cookie;
+		if (S_ISREG(stat->mode) &&
+		    !(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) {
+			chattr += (u64)stat->ctime.tv_sec << 30;
+			chattr += stat->ctime.tv_nsec;
+		}
+	} else {
+		chattr = time_to_chattr(&stat->ctime);
+	}
+	return chattr;
+}
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
new file mode 100644
index 000000000..cdeb5eea6
--- /dev/null
+++ b/fs/nfsd/nfsfh.h
@@ -0,0 +1,342 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ *
+ * This file describes the layout of the file handles as passed
+ * over the wire.
+ */
+#ifndef _LINUX_NFSD_NFSFH_H
+#define _LINUX_NFSD_NFSFH_H
+
+#include <linux/crc32.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/iversion.h>
+#include <linux/exportfs.h>
+#include <linux/nfs4.h>
+
+#include "export.h"
+
+/*
+ * The file handle starts with a sequence of four-byte words.
+ * The first word contains a version number (1) and three descriptor bytes
+ * that tell how the remaining 3 variable length fields should be handled.
+ * These three bytes are auth_type, fsid_type and fileid_type.
+ *
+ * All four-byte values are in host-byte-order.
+ *
+ * The auth_type field is deprecated and must be set to 0.
+ *
+ * The fsid_type identifies how the filesystem (or export point) is
+ *    encoded.
+ *  Current values:
+ *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
+ *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
+ *              says we mustn't.  We must break it up and reassemble.
+ *     1  - 4 byte user specified identifier
+ *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
+ *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
+ *     4  - 4 byte inode number and 4 byte uuid
+ *     5  - 8 byte uuid
+ *     6  - 16 byte uuid
+ *     7  - 8 byte inode number and 16 byte uuid
+ *
+ * The fileid_type identifies how the file within the filesystem is encoded.
+ *   The values for this field are filesystem specific, exccept that
+ *   filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
+ *   in include/linux/exportfs.h for currently registered values.
+ */
+
+struct knfsd_fh {
+	unsigned int	fh_size;	/*
+					 * Points to the current size while
+					 * building a new file handle.
+					 */
+	u8		fh_raw[NFS4_FHSIZE];
+};
+
+#define fh_version		fh_raw[0]
+#define fh_auth_type		fh_raw[1]
+#define fh_fsid_type		fh_raw[2]
+#define fh_fileid_type		fh_raw[3]
+
+static inline u32 *fh_fsid(const struct knfsd_fh *fh)
+{
+	return (u32 *)&fh->fh_raw[4];
+}
+
+static inline __u32 ino_t_to_u32(ino_t ino)
+{
+	return (__u32) ino;
+}
+
+static inline ino_t u32_to_ino_t(__u32 uino)
+{
+	return (ino_t) uino;
+}
+
+/*
+ * This is the internal representation of an NFS handle used in knfsd.
+ * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
+ */
+typedef struct svc_fh {
+	struct knfsd_fh		fh_handle;	/* FH data */
+	int			fh_maxsize;	/* max size for fh_handle */
+	struct dentry *		fh_dentry;	/* validated dentry */
+	struct svc_export *	fh_export;	/* export pointer */
+
+	bool			fh_want_write;	/* remount protection taken */
+	bool			fh_no_wcc;	/* no wcc data needed */
+	bool			fh_no_atomic_attr;
+						/*
+						 * wcc data is not atomic with
+						 * operation
+						 */
+	bool			fh_use_wgather;	/* NFSv2 wgather option */
+	bool			fh_64bit_cookies;/* readdir cookie size */
+	int			fh_flags;	/* FH flags */
+	bool			fh_post_saved;	/* post-op attrs saved */
+	bool			fh_pre_saved;	/* pre-op attrs saved */
+
+	/* Pre-op attributes saved when inode is locked */
+	__u64			fh_pre_size;	/* size before operation */
+	struct timespec64	fh_pre_mtime;	/* mtime before oper */
+	struct timespec64	fh_pre_ctime;	/* ctime before oper */
+	/*
+	 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
+	 *  to find out if it is valid.
+	 */
+	u64			fh_pre_change;
+
+	/* Post-op attributes saved in fh_fill_post_attrs() */
+	struct kstat		fh_post_attr;	/* full attrs after operation */
+	u64			fh_post_change; /* nfsv4 change; see above */
+} svc_fh;
+#define NFSD4_FH_FOREIGN (1<<0)
+#define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
+#define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
+
+enum nfsd_fsid {
+	FSID_DEV = 0,
+	FSID_NUM,
+	FSID_MAJOR_MINOR,
+	FSID_ENCODE_DEV,
+	FSID_UUID4_INUM,
+	FSID_UUID8,
+	FSID_UUID16,
+	FSID_UUID16_INUM,
+};
+
+enum fsid_source {
+	FSIDSOURCE_DEV,
+	FSIDSOURCE_FSID,
+	FSIDSOURCE_UUID,
+};
+extern enum fsid_source fsid_source_fh(const struct knfsd_fh *fh,
+				       struct svc_export *exp);
+extern enum fsid_source fsid_source(const struct svc_fh *fhp);
+
+
+/*
+ * This might look a little large to "inline" but in all calls except
+ * one, 'vers' is constant so moste of the function disappears.
+ *
+ * In some cases the values are considered to be host endian and in
+ * others, net endian. fsidv is always considered to be u32 as the
+ * callers don't know which it will be. So we must use __force to keep
+ * sparse from complaining. Since these values are opaque to the
+ * client, that shouldn't be a problem.
+ */
+static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
+			   u32 fsid, unsigned char *uuid)
+{
+	u32 *up;
+	switch(vers) {
+	case FSID_DEV:
+		fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
+				 MINOR(dev));
+		fsidv[1] = ino_t_to_u32(ino);
+		break;
+	case FSID_NUM:
+		fsidv[0] = fsid;
+		break;
+	case FSID_MAJOR_MINOR:
+		fsidv[0] = (__force __u32)htonl(MAJOR(dev));
+		fsidv[1] = (__force __u32)htonl(MINOR(dev));
+		fsidv[2] = ino_t_to_u32(ino);
+		break;
+
+	case FSID_ENCODE_DEV:
+		fsidv[0] = new_encode_dev(dev);
+		fsidv[1] = ino_t_to_u32(ino);
+		break;
+
+	case FSID_UUID4_INUM:
+		/* 4 byte fsid and inode number */
+		up = (u32*)uuid;
+		fsidv[0] = ino_t_to_u32(ino);
+		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
+		break;
+
+	case FSID_UUID8:
+		/* 8 byte fsid  */
+		up = (u32*)uuid;
+		fsidv[0] = up[0] ^ up[2];
+		fsidv[1] = up[1] ^ up[3];
+		break;
+
+	case FSID_UUID16:
+		/* 16 byte fsid - NFSv3+ only */
+		memcpy(fsidv, uuid, 16);
+		break;
+
+	case FSID_UUID16_INUM:
+		/* 8 byte inode and 16 byte fsid */
+		*(u64*)fsidv = (u64)ino;
+		memcpy(fsidv+2, uuid, 16);
+		break;
+	default: BUG();
+	}
+}
+
+static inline int key_len(int type)
+{
+	switch(type) {
+	case FSID_DEV:		return 8;
+	case FSID_NUM: 		return 4;
+	case FSID_MAJOR_MINOR:	return 12;
+	case FSID_ENCODE_DEV:	return 8;
+	case FSID_UUID4_INUM:	return 8;
+	case FSID_UUID8:	return 8;
+	case FSID_UUID16:	return 16;
+	case FSID_UUID16_INUM:	return 24;
+	default: return 0;
+	}
+}
+
+/*
+ * Shorthand for dprintk()'s
+ */
+extern char * SVCFH_fmt(struct svc_fh *fhp);
+
+/*
+ * Function prototypes
+ */
+__be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
+__be32	fh_verify_local(struct net *, struct svc_cred *, struct auth_domain *,
+			struct svc_fh *, umode_t, int);
+__be32	fh_getattr(const struct svc_fh *fhp, struct kstat *stat);
+__be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
+__be32	fh_update(struct svc_fh *);
+void	fh_put(struct svc_fh *);
+bool	fh_append_mac(struct knfsd_fh *fh, int fh_maxsize, struct net *net);
+
+static __inline__ struct svc_fh *
+fh_copy(struct svc_fh *dst, const struct svc_fh *src)
+{
+	WARN_ON(src->fh_dentry);
+
+	*dst = *src;
+	return dst;
+}
+
+static inline void
+fh_copy_shallow(struct knfsd_fh *dst, const struct knfsd_fh *src)
+{
+	dst->fh_size = src->fh_size;
+	memcpy(&dst->fh_raw, &src->fh_raw, src->fh_size);
+}
+
+static __inline__ struct svc_fh *
+fh_init(struct svc_fh *fhp, int maxsize)
+{
+	memset(fhp, 0, sizeof(*fhp));
+	fhp->fh_maxsize = maxsize;
+	return fhp;
+}
+
+static inline bool fh_match(const struct knfsd_fh *fh1,
+			    const struct knfsd_fh *fh2)
+{
+	if (fh1->fh_size != fh2->fh_size)
+		return false;
+	if (memcmp(fh1->fh_raw, fh2->fh_raw, fh1->fh_size) != 0)
+		return false;
+	return true;
+}
+
+static inline bool fh_fsid_match(const struct knfsd_fh *fh1,
+				 const struct knfsd_fh *fh2)
+{
+	u32 *fsid1 = fh_fsid(fh1);
+	u32 *fsid2 = fh_fsid(fh2);
+
+	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
+		return false;
+	if (memcmp(fsid1, fsid2, key_len(fh1->fh_fsid_type)) != 0)
+		return false;
+	return true;
+}
+
+/**
+ * fh_want_write - Get write access to an export
+ * @fhp: File handle of file to be written
+ *
+ * Caller must invoke fh_drop_write() when its write operation
+ * is complete.
+ *
+ * Returns 0 if the file handle's export can be written to. Otherwise
+ * the export is not prepared for updates, and the returned negative
+ * errno value reflects the reason for the failure.
+ */
+static inline int fh_want_write(struct svc_fh *fhp)
+{
+	int ret;
+
+	if (fhp->fh_want_write)
+		return 0;
+	ret = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (!ret)
+		fhp->fh_want_write = true;
+	return ret;
+}
+
+/**
+ * fh_drop_write - Release write access on an export
+ * @fhp: File handle of file on which fh_want_write() was previously called
+ */
+static inline void fh_drop_write(struct svc_fh *fhp)
+{
+	if (fhp->fh_want_write) {
+		fhp->fh_want_write = false;
+		mnt_drop_write(fhp->fh_export->ex_path.mnt);
+	}
+}
+
+/**
+ * knfsd_fh_hash - calculate the crc32 hash for the filehandle
+ * @fh - pointer to filehandle
+ *
+ * returns a crc32 hash for the filehandle that is compatible with
+ * the one displayed by "wireshark".
+ */
+static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
+{
+	return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size);
+}
+
+/**
+ * fh_clear_pre_post_attrs - Reset pre/post attributes
+ * @fhp: file handle to be updated
+ *
+ */
+static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp)
+{
+	fhp->fh_post_saved = false;
+	fhp->fh_pre_saved = false;
+}
+
+u64 nfsd4_change_attribute(const struct kstat *stat);
+__be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp);
+__be32 fh_fill_post_attrs(struct svc_fh *fhp);
+__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp);
+#endif /* _LINUX_NFSD_NFSFH_H */
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
new file mode 100644
index 000000000..e2b5f8a24
--- /dev/null
+++ b/fs/nfsd/nfsproc.c
@@ -0,0 +1,854 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 2 NFS requests.
+ *
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/namei.h>
+
+#include "cache.h"
+#include "xdr.h"
+#include "vfs.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static __be32 nfsd_map_status(__be32 status)
+{
+	switch (status) {
+	case nfs_ok:
+		break;
+	case nfserr_nofilehandle:
+	case nfserr_badhandle:
+		status = nfserr_stale;
+		break;
+	case nfserr_wrongsec:
+	case nfserr_xdev:
+	case nfserr_file_open:
+		status = nfserr_acces;
+		break;
+	case nfserr_symlink_not_dir:
+		status = nfserr_notdir;
+		break;
+	case nfserr_symlink:
+	case nfserr_wrong_type:
+		status = nfserr_io;
+		break;
+	}
+	return status;
+}
+
+static __be32
+nfsd_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get a file's attributes
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	trace_nfsd_vfs_getattr(rqstp, &argp->fh);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Set a file's attributes
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_setattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_sattrargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	struct iattr *iap = &argp->attrs;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= iap,
+	};
+	struct svc_fh *fhp;
+	int hosterr;
+
+	dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
+		SVCFH_fmt(&argp->fh),
+		argp->attrs.ia_valid, (long) argp->attrs.ia_size);
+
+	fhp = fh_copy(&resp->fh, &argp->fh);
+
+	/*
+	 * NFSv2 does not differentiate between "set-[ac]time-to-now"
+	 * which only requires access, and "set-[ac]time-to-X" which
+	 * requires ownership.
+	 * So if it looks like it might be "set both to the same time which
+	 * is close to now", and if setattr_prepare fails, then we
+	 * convert to "set to now" instead of "set to explicit time"
+	 *
+	 * We only call setattr_prepare as the last test as technically
+	 * it is not an interface that we should be using.
+	 */
+#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
+#define	MAX_TOUCH_TIME_ERROR (30*60)
+	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
+	    iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
+		/*
+		 * Looks probable.
+		 *
+		 * Now just make sure time is in the right ballpark.
+		 * Solaris, at least, doesn't seem to care what the time
+		 * request is.  We require it be within 30 minutes of now.
+		 */
+		time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
+
+		resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
+		if (resp->status != nfs_ok)
+			goto out;
+
+		hosterr = fh_want_write(fhp);
+		if (hosterr) {
+			resp->status = nfserrno(hosterr);
+			goto out;
+		}
+
+		if (delta < 0)
+			delta = -delta;
+		if (delta < MAX_TOUCH_TIME_ERROR &&
+		    setattr_prepare(&nop_mnt_idmap, fhp->fh_dentry, iap) != 0) {
+			/*
+			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
+			 * This will cause notify_change to set these times
+			 * to "now"
+			 */
+			iap->ia_valid &= ~BOTH_TIME_SET;
+		}
+	}
+
+	resp->status = nfsd_setattr(rqstp, fhp, &attrs, NULL);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/* Obsolete, replaced by MNTPROC_MNT. */
+static __be32
+nfsd_proc_root(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Look up a path name component
+ * Note: the dentry in the resp->fh may be negative if the file
+ * doesn't exist yet.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_lookup(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LOOKUP   %s %.*s\n",
+		SVCFH_fmt(&argp->fh), argp->len, argp->name);
+
+	fh_init(&resp->fh, NFS_FHSIZE);
+	resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
+				   &resp->fh);
+	fh_put(&argp->fh);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Read a symlink.
+ */
+static __be32
+nfsd_proc_readlink(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_readlinkres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
+
+	/* Read the symlink. */
+	resp->len = NFS_MAXPATHLEN;
+	resp->page = *(rqstp->rq_next_page++);
+	resp->status = nfsd_readlink(rqstp, &argp->fh,
+				     page_address(resp->page), &resp->len);
+
+	fh_put(&argp->fh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a file.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_read(struct svc_rqst *rqstp)
+{
+	struct nfsd_readargs *argp = rqstp->rq_argp;
+	struct nfsd_readres *resp = rqstp->rq_resp;
+	u32 eof;
+
+	dprintk("nfsd: READ    %s %d bytes at %d\n",
+		SVCFH_fmt(&argp->fh),
+		argp->count, argp->offset);
+
+	argp->count = min_t(u32, argp->count, NFS_MAXDATA);
+	argp->count = min_t(u32, argp->count, rqstp->rq_res.buflen);
+
+	resp->pages = rqstp->rq_next_page;
+
+	/* Obtain buffer pointer for payload. 19 is 1 word for
+	 * status, 17 words for fattr, and 1 word for the byte count.
+	 */
+	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
+
+	resp->count = argp->count;
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
+				 &resp->count, &eof);
+	if (resp->status == nfs_ok)
+		resp->status = fh_getattr(&resp->fh, &resp->stat);
+	else if (resp->status == nfserr_jukebox)
+		set_bit(RQ_DROPME, &rqstp->rq_flags);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/* Reserved */
+static __be32
+nfsd_proc_writecache(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Write data to a file
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_write(struct svc_rqst *rqstp)
+{
+	struct nfsd_writeargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	unsigned long cnt = argp->len;
+
+	dprintk("nfsd: WRITE    %s %u bytes at %d\n",
+		SVCFH_fmt(&argp->fh),
+		argp->len, argp->offset);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_write(rqstp, &resp->fh, argp->offset,
+				  &argp->payload, &cnt, NFS_DATA_SYNC, NULL);
+	if (resp->status == nfs_ok)
+		resp->status = fh_getattr(&resp->fh, &resp->stat);
+	else if (resp->status == nfserr_jukebox)
+		set_bit(RQ_DROPME, &rqstp->rq_flags);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * CREATE processing is complicated. The keyword here is `overloaded.'
+ * The parent directory is kept locked between the check for existence
+ * and the actual create() call in compliance with VFS protocols.
+ * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
+ */
+static __be32
+nfsd_proc_create(struct svc_rqst *rqstp)
+{
+	struct nfsd_createargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+	svc_fh		*dirfhp = &argp->fh;
+	svc_fh		*newfhp = &resp->fh;
+	struct iattr	*attr = &argp->attrs;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= attr,
+	};
+	struct inode	*inode;
+	struct dentry	*dchild;
+	int		type, mode;
+	int		hosterr;
+	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
+
+	/* First verify the parent file handle */
+	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (resp->status != nfs_ok)
+		goto done; /* must fh_put dirfhp even on error */
+
+	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
+
+	resp->status = nfserr_exist;
+	if (name_is_dot_dotdot(argp->name, argp->len))
+		goto done;
+	hosterr = fh_want_write(dirfhp);
+	if (hosterr) {
+		resp->status = nfserrno(hosterr);
+		goto done;
+	}
+
+	dchild = start_creating(&nop_mnt_idmap, dirfhp->fh_dentry,
+				&QSTR_LEN(argp->name, argp->len));
+	if (IS_ERR(dchild)) {
+		resp->status = nfserrno(PTR_ERR(dchild));
+		goto out_write;
+	}
+	fh_init(newfhp, NFS_FHSIZE);
+	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
+	if (!resp->status && d_really_is_negative(dchild))
+		resp->status = nfserr_noent;
+	if (resp->status) {
+		if (resp->status != nfserr_noent)
+			goto out_unlock;
+		/*
+		 * If the new file handle wasn't verified, we can't tell
+		 * whether the file exists or not. Time to bail ...
+		 */
+		resp->status = nfserr_acces;
+		if (!newfhp->fh_dentry) {
+			printk(KERN_WARNING
+				"nfsd_proc_create: file handle not verified\n");
+			goto out_unlock;
+		}
+	}
+
+	inode = d_inode(newfhp->fh_dentry);
+
+	/* Unfudge the mode bits */
+	if (attr->ia_valid & ATTR_MODE) {
+		type = attr->ia_mode & S_IFMT;
+		mode = attr->ia_mode & ~S_IFMT;
+		if (!type) {
+			/* no type, so if target exists, assume same as that,
+			 * else assume a file */
+			if (inode) {
+				type = inode->i_mode & S_IFMT;
+				switch(type) {
+				case S_IFCHR:
+				case S_IFBLK:
+					/* reserve rdev for later checking */
+					rdev = inode->i_rdev;
+					attr->ia_valid |= ATTR_SIZE;
+
+					fallthrough;
+				case S_IFIFO:
+					/* this is probably a permission check..
+					 * at least IRIX implements perm checking on
+					 *   echo thing > device-special-file-or-pipe
+					 * by doing a CREATE with type==0
+					 */
+					resp->status = nfsd_permission(
+						&rqstp->rq_cred,
+						newfhp->fh_export,
+						newfhp->fh_dentry,
+						NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
+					if (resp->status && resp->status != nfserr_rofs)
+						goto out_unlock;
+				}
+			} else
+				type = S_IFREG;
+		}
+	} else if (inode) {
+		type = inode->i_mode & S_IFMT;
+		mode = inode->i_mode & ~S_IFMT;
+	} else {
+		type = S_IFREG;
+		mode = 0;	/* ??? */
+	}
+
+	attr->ia_valid |= ATTR_MODE;
+	attr->ia_mode = mode;
+
+	/* Special treatment for non-regular files according to the
+	 * gospel of sun micro
+	 */
+	if (type != S_IFREG) {
+		if (type != S_IFBLK && type != S_IFCHR) {
+			rdev = 0;
+		} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
+			/* If you think you've seen the worst, grok this. */
+			type = S_IFIFO;
+		} else {
+			/* Okay, char or block special */
+			if (!rdev)
+				rdev = wanted;
+		}
+
+		/* we've used the SIZE information, so discard it */
+		attr->ia_valid &= ~ATTR_SIZE;
+
+		/* Make sure the type and device matches */
+		resp->status = nfserr_exist;
+		if (inode && inode_wrong_type(inode, type))
+			goto out_unlock;
+	}
+
+	resp->status = nfs_ok;
+	if (!inode) {
+		/* File doesn't exist. Create it and set attrs */
+		resp->status = nfsd_create_locked(rqstp, dirfhp, &attrs, type,
+						  rdev, newfhp);
+		/* nfsd_create_locked() unlocked the parent */
+		dput(dchild);
+		goto out_write;
+	} else if (type == S_IFREG) {
+		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
+			argp->name, attr->ia_valid, (long) attr->ia_size);
+		/* File already exists. We ignore all attributes except
+		 * size, so that creat() behaves exactly like
+		 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
+		 */
+		attr->ia_valid &= ATTR_SIZE;
+		if (attr->ia_valid)
+			resp->status = nfsd_setattr(rqstp, newfhp, &attrs,
+						    NULL);
+	}
+
+out_unlock:
+	end_creating(dchild);
+out_write:
+	fh_drop_write(dirfhp);
+done:
+	fh_put(dirfhp);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_remove(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	/* Unlink. -SIFDIR means file must not be a directory */
+	resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
+				   argp->name, argp->len);
+	fh_put(&argp->fh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_rename(struct svc_rqst *rqstp)
+{
+	struct nfsd_renameargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
+				   &argp->tfh, argp->tname, argp->tlen);
+	fh_put(&argp->ffh);
+	fh_put(&argp->tfh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_link(struct svc_rqst *rqstp)
+{
+	struct nfsd_linkargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
+				 &argp->ffh);
+	fh_put(&argp->ffh);
+	fh_put(&argp->tfh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_symlink(struct svc_rqst *rqstp)
+{
+	struct nfsd_symlinkargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+	struct svc_fh	newfh;
+
+	if (argp->tlen > NFS_MAXPATHLEN) {
+		resp->status = nfserr_nametoolong;
+		goto out;
+	}
+
+	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
+						page_address(rqstp->rq_arg.pages[0]),
+						argp->tlen);
+	if (IS_ERR(argp->tname)) {
+		resp->status = nfserrno(PTR_ERR(argp->tname));
+		goto out;
+	}
+
+	fh_init(&newfh, NFS_FHSIZE);
+	resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
+				    argp->tname, &attrs, &newfh);
+
+	kfree(argp->tname);
+	fh_put(&argp->ffh);
+	fh_put(&newfh);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Make directory. This operation is not idempotent.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_mkdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_createargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+	struct nfsd_attrs attrs = {
+		.na_iattr	= &argp->attrs,
+	};
+
+	if (resp->fh.fh_dentry) {
+		printk(KERN_WARNING
+			"nfsd_proc_mkdir: response already verified??\n");
+	}
+
+	argp->attrs.ia_valid &= ~ATTR_SIZE;
+	fh_init(&resp->fh, NFS_FHSIZE);
+	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
+				   &attrs, S_IFDIR, 0, &resp->fh);
+	fh_put(&argp->fh);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Remove a directory
+ */
+static __be32
+nfsd_proc_rmdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
+				   argp->name, argp->len);
+	fh_put(&argp->fh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp,
+				    struct nfsd_readdirres *resp,
+				    u32 count)
+{
+	struct xdr_buf *buf = &resp->dirlist;
+	struct xdr_stream *xdr = &resp->xdr;
+
+	memset(buf, 0, sizeof(*buf));
+
+	/* Reserve room for the NULL ptr & eof flag (-2 words) */
+	buf->buflen = clamp(count, (u32)(XDR_UNIT * 2), (u32)PAGE_SIZE);
+	buf->buflen -= XDR_UNIT * 2;
+	buf->pages = rqstp->rq_next_page;
+	rqstp->rq_next_page++;
+
+	xdr_init_encode_pages(xdr, buf);
+}
+
+/*
+ * Read a portion of a directory.
+ */
+static __be32
+nfsd_proc_readdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd_readdirres *resp = rqstp->rq_resp;
+	loff_t		offset;
+
+	trace_nfsd_vfs_readdir(rqstp, &argp->fh, argp->count, argp->cookie);
+
+	nfsd_init_dirlist_pages(rqstp, resp, argp->count);
+
+	resp->common.err = nfs_ok;
+	resp->cookie_offset = 0;
+	offset = argp->cookie;
+	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
+				    &resp->common, nfssvc_encode_entry);
+	nfssvc_encode_nfscookie(resp, offset);
+
+	fh_put(&argp->fh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * Get file system info
+ */
+static __be32
+nfsd_proc_statfs(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_statfsres *resp = rqstp->rq_resp;
+
+	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
+				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	fh_put(&argp->fh);
+	resp->status = nfsd_map_status(resp->status);
+	return rpc_success;
+}
+
+/*
+ * NFSv2 Server procedures.
+ * Only the results of non-idempotent operations are cached.
+ */
+
+#define ST 1		/* status */
+#define FH 8		/* filehandle */
+#define	AT 18		/* attributes */
+
+static const struct svc_procedure nfsd_procedures2[18] = {
+	[NFSPROC_NULL] = {
+		.pc_func = nfsd_proc_null,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+		.pc_name = "NULL",
+	},
+	[NFSPROC_GETATTR] = {
+		.pc_func = nfsd_proc_getattr,
+		.pc_decode = nfssvc_decode_fhandleargs,
+		.pc_encode = nfssvc_encode_attrstatres,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "GETATTR",
+	},
+	[NFSPROC_SETATTR] = {
+		.pc_func = nfsd_proc_setattr,
+		.pc_decode = nfssvc_decode_sattrargs,
+		.pc_encode = nfssvc_encode_attrstatres,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_sattrargs),
+		.pc_argzero = sizeof(struct nfsd_sattrargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "SETATTR",
+	},
+	[NFSPROC_ROOT] = {
+		.pc_func = nfsd_proc_root,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+		.pc_name = "ROOT",
+	},
+	[NFSPROC_LOOKUP] = {
+		.pc_func = nfsd_proc_lookup,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_argzero = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+FH+AT,
+		.pc_name = "LOOKUP",
+	},
+	[NFSPROC_READLINK] = {
+		.pc_func = nfsd_proc_readlink,
+		.pc_decode = nfssvc_decode_fhandleargs,
+		.pc_encode = nfssvc_encode_readlinkres,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_readlinkres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
+		.pc_name = "READLINK",
+	},
+	[NFSPROC_READ] = {
+		.pc_func = nfsd_proc_read,
+		.pc_decode = nfssvc_decode_readargs,
+		.pc_encode = nfssvc_encode_readres,
+		.pc_release = nfssvc_release_readres,
+		.pc_argsize = sizeof(struct nfsd_readargs),
+		.pc_argzero = sizeof(struct nfsd_readargs),
+		.pc_ressize = sizeof(struct nfsd_readres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT+1+NFS_MAXDATA/4,
+		.pc_name = "READ",
+	},
+	[NFSPROC_WRITECACHE] = {
+		.pc_func = nfsd_proc_writecache,
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_argzero = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+		.pc_name = "WRITECACHE",
+	},
+	[NFSPROC_WRITE] = {
+		.pc_func = nfsd_proc_write,
+		.pc_decode = nfssvc_decode_writeargs,
+		.pc_encode = nfssvc_encode_attrstatres,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_writeargs),
+		.pc_argzero = sizeof(struct nfsd_writeargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+AT,
+		.pc_name = "WRITE",
+	},
+	[NFSPROC_CREATE] = {
+		.pc_func = nfsd_proc_create,
+		.pc_decode = nfssvc_decode_createargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_createargs),
+		.pc_argzero = sizeof(struct nfsd_createargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+FH+AT,
+		.pc_name = "CREATE",
+	},
+	[NFSPROC_REMOVE] = {
+		.pc_func = nfsd_proc_remove,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_statres,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_argzero = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+		.pc_name = "REMOVE",
+	},
+	[NFSPROC_RENAME] = {
+		.pc_func = nfsd_proc_rename,
+		.pc_decode = nfssvc_decode_renameargs,
+		.pc_encode = nfssvc_encode_statres,
+		.pc_argsize = sizeof(struct nfsd_renameargs),
+		.pc_argzero = sizeof(struct nfsd_renameargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+		.pc_name = "RENAME",
+	},
+	[NFSPROC_LINK] = {
+		.pc_func = nfsd_proc_link,
+		.pc_decode = nfssvc_decode_linkargs,
+		.pc_encode = nfssvc_encode_statres,
+		.pc_argsize = sizeof(struct nfsd_linkargs),
+		.pc_argzero = sizeof(struct nfsd_linkargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+		.pc_name = "LINK",
+	},
+	[NFSPROC_SYMLINK] = {
+		.pc_func = nfsd_proc_symlink,
+		.pc_decode = nfssvc_decode_symlinkargs,
+		.pc_encode = nfssvc_encode_statres,
+		.pc_argsize = sizeof(struct nfsd_symlinkargs),
+		.pc_argzero = sizeof(struct nfsd_symlinkargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+		.pc_name = "SYMLINK",
+	},
+	[NFSPROC_MKDIR] = {
+		.pc_func = nfsd_proc_mkdir,
+		.pc_decode = nfssvc_decode_createargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_createargs),
+		.pc_argzero = sizeof(struct nfsd_createargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+FH+AT,
+		.pc_name = "MKDIR",
+	},
+	[NFSPROC_RMDIR] = {
+		.pc_func = nfsd_proc_rmdir,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_statres,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_argzero = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+		.pc_name = "RMDIR",
+	},
+	[NFSPROC_READDIR] = {
+		.pc_func = nfsd_proc_readdir,
+		.pc_decode = nfssvc_decode_readdirargs,
+		.pc_encode = nfssvc_encode_readdirres,
+		.pc_argsize = sizeof(struct nfsd_readdirargs),
+		.pc_argzero = sizeof(struct nfsd_readdirargs),
+		.pc_ressize = sizeof(struct nfsd_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_name = "READDIR",
+	},
+	[NFSPROC_STATFS] = {
+		.pc_func = nfsd_proc_statfs,
+		.pc_decode = nfssvc_decode_fhandleargs,
+		.pc_encode = nfssvc_encode_statfsres,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_argzero = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_statfsres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+5,
+		.pc_name = "STATFS",
+	},
+};
+
+const struct svc_version nfsd_version2 = {
+	.vs_vers	= 2,
+	.vs_nproc	= ARRAY_SIZE(nfsd_procedures2),
+	.vs_proc	= nfsd_procedures2,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS2_SVC_XDRSIZE,
+};
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
new file mode 100644
index 000000000..2edf716ea
--- /dev/null
+++ b/fs/nfsd/nfssvc.c
@@ -0,0 +1,1095 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Central processing for nfsd.
+ *
+ * Authors:	Olaf Kirch (okir@monad.swb.de)
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched/signal.h>
+#include <linux/freezer.h>
+#include <linux/module.h>
+#include <linux/fs_struct.h>
+#include <linux/swap.h>
+#include <linux/siphash.h>
+
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/lockd/bind.h>
+#include <linux/nfsacl.h>
+#include <linux/nfslocalio.h>
+#include <linux/seq_file.h>
+#include <linux/inetdevice.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <net/net_namespace.h>
+#include "nfsd.h"
+#include "cache.h"
+#include "vfs.h"
+#include "netns.h"
+#include "filecache.h"
+
+#include "trace.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_SVC
+
+atomic_t			nfsd_th_cnt = ATOMIC_INIT(0);
+static int			nfsd(void *vrqstp);
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static int			nfsd_acl_rpcbind_set(struct net *,
+						     const struct svc_program *,
+						     u32, int,
+						     unsigned short,
+						     unsigned short);
+static __be32			nfsd_acl_init_request(struct svc_rqst *,
+						const struct svc_program *,
+						struct svc_process_info *);
+#endif
+static int			nfsd_rpcbind_set(struct net *,
+						 const struct svc_program *,
+						 u32, int,
+						 unsigned short,
+						 unsigned short);
+static __be32			nfsd_init_request(struct svc_rqst *,
+						const struct svc_program *,
+						struct svc_process_info *);
+
+/*
+ * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members
+ * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
+ *
+ * Finally, the nfsd_mutex also protects some of the global variables that are
+ * accessed when nfsd starts and that are settable via the write_* routines in
+ * nfsctl.c. In particular:
+ *
+ *	user_recovery_dirname
+ *	user_lease_time
+ *	nfsd_versions
+ */
+DEFINE_MUTEX(nfsd_mutex);
+
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+static const struct svc_version *localio_versions[] = {
+	[1] = &localio_version1,
+};
+
+#define NFSD_LOCALIO_NRVERS		ARRAY_SIZE(localio_versions)
+
+#endif /* CONFIG_NFS_LOCALIO */
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static const struct svc_version *nfsd_acl_version[] = {
+# if defined(CONFIG_NFSD_V2_ACL)
+	[2] = &nfsd_acl_version2,
+# endif
+# if defined(CONFIG_NFSD_V3_ACL)
+	[3] = &nfsd_acl_version3,
+# endif
+};
+
+#define NFSD_ACL_MINVERS	2
+#define NFSD_ACL_NRVERS		ARRAY_SIZE(nfsd_acl_version)
+
+#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
+
+static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
+#if defined(CONFIG_NFSD_V2)
+	[2] = &nfsd_version2,
+#endif
+	[3] = &nfsd_version3,
+#if defined(CONFIG_NFSD_V4)
+	[4] = &nfsd_version4,
+#endif
+};
+
+struct svc_program		nfsd_programs[] = {
+	{
+	.pg_prog		= NFS_PROGRAM,		/* program number */
+	.pg_nvers		= NFSD_MAXVERS+1,	/* nr of entries in nfsd_version */
+	.pg_vers		= nfsd_version,		/* version table */
+	.pg_name		= "nfsd",		/* program name */
+	.pg_class		= "nfsd",		/* authentication class */
+	.pg_authenticate	= svc_set_client,	/* export authentication */
+	.pg_init_request	= nfsd_init_request,
+	.pg_rpcbind_set		= nfsd_rpcbind_set,
+	},
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+	{
+	.pg_prog		= NFS_ACL_PROGRAM,
+	.pg_nvers		= NFSD_ACL_NRVERS,
+	.pg_vers		= nfsd_acl_version,
+	.pg_name		= "nfsacl",
+	.pg_class		= "nfsd",
+	.pg_authenticate	= svc_set_client,
+	.pg_init_request	= nfsd_acl_init_request,
+	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
+	},
+#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
+#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+	{
+	.pg_prog		= NFS_LOCALIO_PROGRAM,
+	.pg_nvers		= NFSD_LOCALIO_NRVERS,
+	.pg_vers		= localio_versions,
+	.pg_name		= "nfslocalio",
+	.pg_class		= "nfsd",
+	.pg_authenticate	= svc_set_client,
+	.pg_init_request	= svc_generic_init_request,
+	.pg_rpcbind_set		= svc_generic_rpcbind_set,
+	}
+#endif /* CONFIG_NFS_LOCALIO */
+};
+
+bool nfsd_support_version(int vers)
+{
+	if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS)
+		return nfsd_version[vers] != NULL;
+	return false;
+}
+
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
+{
+	if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS)
+		return 0;
+	switch(change) {
+	case NFSD_SET:
+		nn->nfsd_versions[vers] = nfsd_support_version(vers);
+		break;
+	case NFSD_CLEAR:
+		nn->nfsd_versions[vers] = false;
+		break;
+	case NFSD_TEST:
+		return nn->nfsd_versions[vers];
+	case NFSD_AVAIL:
+		return nfsd_support_version(vers);
+	}
+	return 0;
+}
+
+static void
+nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
+{
+	unsigned i;
+
+	for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
+		if (nn->nfsd4_minorversions[i])
+			return;
+	}
+	nfsd_vers(nn, 4, NFSD_CLEAR);
+}
+
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
+{
+	if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
+	    change != NFSD_AVAIL)
+		return -1;
+
+	switch(change) {
+	case NFSD_SET:
+		nfsd_vers(nn, 4, NFSD_SET);
+		nn->nfsd4_minorversions[minorversion] =
+			nfsd_vers(nn, 4, NFSD_TEST);
+		break;
+	case NFSD_CLEAR:
+		nn->nfsd4_minorversions[minorversion] = false;
+		nfsd_adjust_nfsd_versions4(nn);
+		break;
+	case NFSD_TEST:
+		return nn->nfsd4_minorversions[minorversion];
+	case NFSD_AVAIL:
+		return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
+			nfsd_vers(nn, 4, NFSD_AVAIL);
+	}
+	return 0;
+}
+
+bool nfsd_net_try_get(struct net *net) __must_hold(rcu)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	return (nn && percpu_ref_tryget_live(&nn->nfsd_net_ref));
+}
+
+void nfsd_net_put(struct net *net) __must_hold(rcu)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	percpu_ref_put(&nn->nfsd_net_ref);
+}
+
+static void nfsd_net_done(struct percpu_ref *ref)
+{
+	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref);
+
+	complete(&nn->nfsd_net_confirm_done);
+}
+
+static void nfsd_net_free(struct percpu_ref *ref)
+{
+	struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref);
+
+	complete(&nn->nfsd_net_free_done);
+}
+
+/*
+ * Maximum number of nfsd processes
+ */
+#define	NFSD_MAXSERVS		8192
+
+/**
+ * nfsd_nrthreads - report a namespace's configured nfsd thread count
+ * @net: network namespace to query
+ *
+ * Return: the configured thread ceiling, or 0 when no service runs.
+ */
+int nfsd_nrthreads(struct net *net)
+{
+	int rv = 0;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	/* nfsd_mutex keeps nn->nfsd_serv valid across the read. */
+	mutex_lock(&nfsd_mutex);
+	if (nn->nfsd_serv)
+		rv = svc_serv_maxthreads(nn->nfsd_serv);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+static int nfsd_users = 0;
+
+static int nfsd_startup_generic(void)
+{
+	int ret;
+
+	if (nfsd_users++)
+		return 0;
+
+	ret = nfsd_file_cache_init();
+	if (ret)
+		goto dec_users;
+
+	ret = nfs4_state_start();
+	if (ret)
+		goto out_file_cache;
+	return 0;
+
+out_file_cache:
+	nfsd_file_cache_shutdown();
+dec_users:
+	nfsd_users--;
+	return ret;
+}
+
+static void nfsd_shutdown_generic(void)
+{
+	if (--nfsd_users)
+		return;
+
+	nfs4_state_shutdown();
+	nfsd_file_cache_shutdown();
+}
+
+static bool nfsd_needs_lockd(struct nfsd_net *nn)
+{
+	return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
+}
+
+/**
+ * nfsd_copy_write_verifier - Atomically copy a write verifier
+ * @verf: buffer in which to receive the verifier cookie
+ * @nn: NFS net namespace
+ *
+ * This function provides a wait-free mechanism for copying the
+ * namespace's write verifier without tearing it.
+ */
+void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn)
+{
+	unsigned int seq;
+
+	do {
+		seq = read_seqbegin(&nn->writeverf_lock);
+		memcpy(verf, nn->writeverf, sizeof(nn->writeverf));
+	} while (read_seqretry(&nn->writeverf_lock, seq));
+}
+
+static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn)
+{
+	struct timespec64 now;
+	u64 verf;
+
+	/*
+	 * Because the time value is hashed, y2038 time_t overflow
+	 * is irrelevant in this usage.
+	 */
+	ktime_get_raw_ts64(&now);
+	verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key);
+	memcpy(nn->writeverf, &verf, sizeof(nn->writeverf));
+}
+
+/**
+ * nfsd_reset_write_verifier - Generate a new write verifier
+ * @nn: NFS net namespace
+ *
+ * This function updates the ->writeverf field of @nn. This field
+ * contains an opaque cookie that, according to Section 18.32.3 of
+ * RFC 8881, "the client can use to determine whether a server has
+ * changed instance state (e.g., server restart) between a call to
+ * WRITE and a subsequent call to either WRITE or COMMIT.  This
+ * cookie MUST be unchanged during a single instance of the NFSv4.1
+ * server and MUST be unique between instances of the NFSv4.1
+ * server."
+ */
+void nfsd_reset_write_verifier(struct nfsd_net *nn)
+{
+	write_seqlock(&nn->writeverf_lock);
+	nfsd_reset_write_verifier_locked(nn);
+	write_sequnlock(&nn->writeverf_lock);
+}
+
+/*
+ * Crank up a set of per-namespace resources for a new NFSD instance,
+ * including lockd, a duplicate reply cache, an open file cache
+ * instance, and a cache of NFSv4 state objects.
+ */
+static int nfsd_startup_net(struct net *net, const struct cred *cred)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int ret;
+
+	if (test_bit(NFSD_NET_UP, &nn->flags))
+		return 0;
+
+	ret = nfsd_startup_generic();
+	if (ret)
+		return ret;
+
+	if (list_empty(&nn->nfsd_serv->sv_permsocks)) {
+		pr_warn("NFSD: Failed to start, no listeners configured.\n");
+		ret = -EIO;
+		goto out_socks;
+	}
+
+	if (nfsd_needs_lockd(nn) && !test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) {
+		ret = lockd_up(net, cred);
+		if (ret)
+			goto out_socks;
+		set_bit(NFSD_NET_LOCKD_UP, &nn->flags);
+	}
+
+	ret = nfsd_file_cache_start_net(net);
+	if (ret)
+		goto out_lockd;
+
+	ret = nfsd_reply_cache_init(nn);
+	if (ret)
+		goto out_filecache;
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+	nfsd4_ssc_init_umount_work(nn);
+#endif
+	ret = nfs4_state_start_net(net);
+	if (ret)
+		goto out_reply_cache;
+
+	set_bit(NFSD_NET_UP, &nn->flags);
+	return 0;
+
+out_reply_cache:
+	nfsd_reply_cache_shutdown(nn);
+out_filecache:
+	nfsd_file_cache_shutdown_net(net);
+out_lockd:
+	if (test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) {
+		lockd_down(net);
+		clear_bit(NFSD_NET_LOCKD_UP, &nn->flags);
+	}
+out_socks:
+	nfsd_shutdown_generic();
+	return ret;
+}
+
+static void nfsd_shutdown_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (test_bit(NFSD_NET_UP, &nn->flags)) {
+		percpu_ref_kill_and_confirm(&nn->nfsd_net_ref, nfsd_net_done);
+		wait_for_completion(&nn->nfsd_net_confirm_done);
+
+		nfsd_export_flush(net);
+		nfs4_state_shutdown_net(net);
+		nfsd_reply_cache_shutdown(nn);
+		nfsd_file_cache_shutdown_net(net);
+		if (test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) {
+			lockd_down(net);
+			clear_bit(NFSD_NET_LOCKD_UP, &nn->flags);
+		}
+		wait_for_completion(&nn->nfsd_net_free_done);
+	}
+
+	percpu_ref_exit(&nn->nfsd_net_ref);
+
+	if (test_bit(NFSD_NET_UP, &nn->flags))
+		nfsd_shutdown_generic();
+	clear_bit(NFSD_NET_UP, &nn->flags);
+}
+
+static DEFINE_SPINLOCK(nfsd_notifier_lock);
+static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
+	void *ptr)
+{
+	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
+	struct net_device *dev = ifa->ifa_dev->dev;
+	struct net *net = dev_net(dev);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct sockaddr_in sin;
+
+	if (event != NETDEV_DOWN || !nn->nfsd_serv)
+		goto out;
+
+	spin_lock(&nfsd_notifier_lock);
+	if (nn->nfsd_serv) {
+		dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
+		sin.sin_family = AF_INET;
+		sin.sin_addr.s_addr = ifa->ifa_local;
+		svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
+	}
+	spin_unlock(&nfsd_notifier_lock);
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nfsd_inetaddr_notifier = {
+	.notifier_call = nfsd_inetaddr_event,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int nfsd_inet6addr_event(struct notifier_block *this,
+	unsigned long event, void *ptr)
+{
+	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
+	struct net_device *dev = ifa->idev->dev;
+	struct net *net = dev_net(dev);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct sockaddr_in6 sin6;
+
+	if (event != NETDEV_DOWN || !nn->nfsd_serv)
+		goto out;
+
+	spin_lock(&nfsd_notifier_lock);
+	if (nn->nfsd_serv) {
+		dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
+		sin6.sin6_family = AF_INET6;
+		sin6.sin6_addr = ifa->addr;
+		if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+			sin6.sin6_scope_id = ifa->idev->dev->ifindex;
+		svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
+	}
+	spin_unlock(&nfsd_notifier_lock);
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nfsd_inet6addr_notifier = {
+	.notifier_call = nfsd_inet6addr_event,
+};
+#endif
+
+/* Only used under nfsd_mutex, so this atomic may be overkill: */
+static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
+
+/**
+ * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace
+ * @net: network namespace the NFS service is associated with
+ */
+void nfsd_destroy_serv(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv = nn->nfsd_serv;
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	spin_lock(&nfsd_notifier_lock);
+	nn->nfsd_serv = NULL;
+	spin_unlock(&nfsd_notifier_lock);
+
+	/* check if the notifier still has clients */
+	if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
+		unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+		unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
+#endif
+	}
+
+	/*
+	 * write_ports can create the server without actually starting
+	 * any threads.  If we get shut down before any threads are
+	 * started, then nfsd_destroy_serv will be run before any of this
+	 * other initialization has been done except the rpcb information.
+	 */
+	svc_xprt_destroy_all(serv, net, true);
+	nfsd_shutdown_net(net);
+	svc_destroy(&serv);
+}
+
+void nfsd_reset_versions(struct nfsd_net *nn)
+{
+	int i;
+
+	for (i = 0; i <= NFSD_MAXVERS; i++)
+		if (nfsd_vers(nn, i, NFSD_TEST))
+			return;
+
+	for (i = 0; i <= NFSD_MAXVERS; i++)
+		if (i != 4)
+			nfsd_vers(nn, i, NFSD_SET);
+		else {
+			int minor = 0;
+			while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
+				minor++;
+		}
+}
+
+static int nfsd_get_default_max_blksize(void)
+{
+	struct sysinfo i;
+	unsigned long long target;
+	unsigned long ret;
+
+	si_meminfo(&i);
+	target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
+	/*
+	 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
+	 * machines, but only uses 32K on 128M machines.  Bottom out at
+	 * 8K on 32M and smaller.  Of course, this is only a default.
+	 */
+	target >>= 12;
+
+	ret = NFSSVC_DEFBLKSIZE;
+	while (ret > target && ret >= 8*1024*2)
+		ret /= 2;
+	return ret;
+}
+
+void nfsd_shutdown_threads(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	mutex_lock(&nfsd_mutex);
+	serv = nn->nfsd_serv;
+	if (serv == NULL) {
+		mutex_unlock(&nfsd_mutex);
+		return;
+	}
+
+	/* Kill outstanding nfsd threads */
+	svc_set_num_threads(serv, 0, 0);
+	nfsd_destroy_serv(net);
+	mutex_unlock(&nfsd_mutex);
+}
+
+struct svc_rqst *nfsd_current_rqst(void)
+{
+	if (kthread_func(current) == nfsd)
+		return kthread_data(current);
+	return NULL;
+}
+
+int nfsd_create_serv(struct net *net)
+{
+	int error;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	WARN_ON(!mutex_is_locked(&nfsd_mutex));
+	if (nn->nfsd_serv)
+		return 0;
+
+	error = percpu_ref_init(&nn->nfsd_net_ref, nfsd_net_free,
+				0, GFP_KERNEL);
+	if (error)
+		return error;
+	init_completion(&nn->nfsd_net_free_done);
+	init_completion(&nn->nfsd_net_confirm_done);
+
+	if (nfsd_max_blksize == 0)
+		nfsd_max_blksize = nfsd_get_default_max_blksize();
+	nfsd_reset_versions(nn);
+	serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs),
+				 &nn->nfsd_svcstats,
+				 nfsd_max_blksize, nfsd);
+	if (serv == NULL) {
+		percpu_ref_exit(&nn->nfsd_net_ref);
+		return -ENOMEM;
+	}
+
+	error = svc_bind(serv, net);
+	if (error < 0) {
+		svc_destroy(&serv);
+		percpu_ref_exit(&nn->nfsd_net_ref);
+		return error;
+	}
+	spin_lock(&nfsd_notifier_lock);
+	nn->nfsd_serv = serv;
+	spin_unlock(&nfsd_notifier_lock);
+
+	/* check if the notifier is already set */
+	if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
+		register_inetaddr_notifier(&nfsd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+		register_inet6addr_notifier(&nfsd_inet6addr_notifier);
+#endif
+	}
+	nfsd_reset_write_verifier(nn);
+	return 0;
+}
+
+int nfsd_nrpools(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->nfsd_serv == NULL)
+		return 0;
+	else
+		return svc_serv_nrpools(nn->nfsd_serv);
+}
+
+int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv = nn->nfsd_serv;
+	int i;
+
+	if (serv)
+		for (i = 0; i < svc_serv_nrpools(serv) && i < n; i++)
+			nthreads[i] = serv->sv_pools[i].sp_nrthrmax;
+	return 0;
+}
+
+/**
+ * nfsd_set_nrthreads - set the number of running threads in the net's service
+ * @n: number of array members in @nthreads
+ * @nthreads: array of thread counts for each pool
+ * @net: network namespace to operate within
+ *
+ * This function alters the number of running threads for the given network
+ * namespace in each pool. If passed an array longer then the number of pools
+ * the extra pool settings are ignored. If passed an array shorter than the
+ * number of pools, the missing values are interpreted as 0's.
+ *
+ * Returns 0 on success or a negative errno on error.
+ */
+int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
+{
+	int i = 0;
+	int tot = 0;
+	int err = 0;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	if (nn->nfsd_serv == NULL || n <= 0)
+		return 0;
+
+	/* Special case: When n == 1, distribute threads equally among pools. */
+	if (n == 1)
+		return svc_set_num_threads(nn->nfsd_serv, nn->min_threads, nthreads[0]);
+
+	if (n > svc_serv_nrpools(nn->nfsd_serv))
+		n = svc_serv_nrpools(nn->nfsd_serv);
+
+	/* enforce a global maximum number of threads */
+	tot = 0;
+	for (i = 0; i < n; i++) {
+		nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
+		tot += nthreads[i];
+	}
+	if (tot > NFSD_MAXSERVS) {
+		/* total too large: scale down requested numbers */
+		for (i = 0; i < n && tot > 0; i++) {
+			int new = nthreads[i] * NFSD_MAXSERVS / tot;
+			tot -= (nthreads[i] - new);
+			nthreads[i] = new;
+		}
+		for (i = 0; i < n && tot > 0; i++) {
+			nthreads[i]--;
+			tot--;
+		}
+	}
+
+	/* apply the new numbers */
+	for (i = 0; i < n; i++) {
+		err = svc_set_pool_threads(nn->nfsd_serv,
+					   &nn->nfsd_serv->sv_pools[i],
+					   nn->min_threads, nthreads[i]);
+		if (err)
+			goto out;
+	}
+
+	/* Anything undefined in array is considered to be 0 */
+	for (i = n; i < svc_serv_nrpools(nn->nfsd_serv); ++i) {
+		err = svc_set_pool_threads(nn->nfsd_serv,
+					   &nn->nfsd_serv->sv_pools[i],
+					   0, 0);
+		if (err)
+			goto out;
+	}
+out:
+	return err;
+}
+
+/**
+ * nfsd_svc: start up or shut down the nfsd server
+ * @n: number of array members in @nthreads
+ * @nthreads: array of thread counts for each pool
+ * @net: network namespace to operate within
+ * @cred: credentials to use for xprt creation
+ * @scope: server scope value (defaults to nodename)
+ *
+ * Adjust the number of threads in each pool and return the new
+ * total number of threads in the service.
+ */
+int
+nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope)
+{
+	int	error;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	lockdep_assert_held(&nfsd_mutex);
+
+	dprintk("nfsd: creating service\n");
+
+	strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename,
+		sizeof(nn->nfsd_name));
+
+	error = nfsd_create_serv(net);
+	if (error)
+		goto out;
+	serv = nn->nfsd_serv;
+
+	error = nfsd_startup_net(net, cred);
+	if (error)
+		goto out_put;
+	error = nfsd_set_nrthreads(n, nthreads, net);
+	if (error)
+		goto out_put;
+	error = serv->sv_nrthreads;
+out_put:
+	if (serv->sv_nrthreads == 0)
+		nfsd_destroy_serv(net);
+out:
+	return error;
+}
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static bool
+nfsd_support_acl_version(int vers)
+{
+	if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
+		return nfsd_acl_version[vers] != NULL;
+	return false;
+}
+
+static int
+nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
+		     u32 version, int family, unsigned short proto,
+		     unsigned short port)
+{
+	if (!nfsd_support_acl_version(version) ||
+	    !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
+		return 0;
+	return svc_generic_rpcbind_set(net, progp, version, family,
+			proto, port);
+}
+
+static __be32
+nfsd_acl_init_request(struct svc_rqst *rqstp,
+		      const struct svc_program *progp,
+		      struct svc_process_info *ret)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	int i;
+
+	if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
+	    nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
+		return svc_generic_init_request(rqstp, progp, ret);
+
+	ret->mismatch.lovers = NFSD_ACL_NRVERS;
+	for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
+		if (nfsd_support_acl_version(i) &&
+		    nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.lovers = i;
+			break;
+		}
+	}
+	if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
+		return rpc_prog_unavail;
+	ret->mismatch.hivers = NFSD_ACL_MINVERS;
+	for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
+		if (nfsd_support_acl_version(i) &&
+		    nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.hivers = i;
+			break;
+		}
+	}
+	return rpc_prog_mismatch;
+}
+#endif
+
+static int
+nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
+		 u32 version, int family, unsigned short proto,
+		 unsigned short port)
+{
+	if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
+		return 0;
+	return svc_generic_rpcbind_set(net, progp, version, family,
+			proto, port);
+}
+
+static __be32
+nfsd_init_request(struct svc_rqst *rqstp,
+		  const struct svc_program *progp,
+		  struct svc_process_info *ret)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	int i;
+
+	if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
+		return svc_generic_init_request(rqstp, progp, ret);
+
+	ret->mismatch.lovers = NFSD_MAXVERS + 1;
+	for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) {
+		if (nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.lovers = i;
+			break;
+		}
+	}
+	if (ret->mismatch.lovers > NFSD_MAXVERS)
+		return rpc_prog_unavail;
+	ret->mismatch.hivers = NFSD_MINVERS;
+	for (i = NFSD_MAXVERS; i >= NFSD_MINVERS; i--) {
+		if (nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.hivers = i;
+			break;
+		}
+	}
+	return rpc_prog_mismatch;
+}
+
+/*
+ * This is the NFS server kernel thread
+ */
+static int
+nfsd(void *vrqstp)
+{
+	struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
+	struct svc_pool *pool = rqstp->rq_pool;
+	struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
+	struct net *net = perm_sock->xpt_net;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfsd_thread_local_info ntli = { };
+	bool have_mutex = false;
+
+	/* At this point, the thread shares current->fs
+	 * with the init process. We need to create files with the
+	 * umask as defined by the client instead of init's umask.
+	 */
+	svc_thread_init_status(rqstp, unshare_fs_struct());
+
+	current->fs->umask = 0;
+
+	atomic_inc(&nfsd_th_cnt);
+
+	set_freezable();
+
+	/* use dynamic allocation if ntli should ever become large */
+	static_assert(sizeof(struct nfsd_thread_local_info) < 256);
+	rqstp->rq_private = &ntli;
+
+	/*
+	 * The main request loop
+	 */
+	while (!svc_thread_should_stop(rqstp)) {
+		switch (svc_recv(rqstp, 5 * HZ)) {
+		case -ETIMEDOUT:
+			/* No work arrived within the timeout window */
+			if (mutex_trylock(&nfsd_mutex)) {
+				if (pool->sp_nrthreads > pool->sp_nrthrmin) {
+					trace_nfsd_dynthread_kill(net, pool);
+					set_bit(RQ_VICTIM, &rqstp->rq_flags);
+					have_mutex = true;
+				} else {
+					mutex_unlock(&nfsd_mutex);
+				}
+			} else {
+				trace_nfsd_dynthread_trylock_fail(net, pool);
+			}
+			break;
+		case -EBUSY:
+			/* No idle threads; consider spawning another */
+			if (pool->sp_nrthreads < pool->sp_nrthrmax) {
+				if (mutex_trylock(&nfsd_mutex)) {
+					if (pool->sp_nrthreads < pool->sp_nrthrmax) {
+						int ret;
+
+						trace_nfsd_dynthread_start(net, pool);
+						ret = svc_new_thread(rqstp->rq_server, pool);
+						if (ret)
+							pr_notice_ratelimited("%s: unable to spawn new thread: %d\n",
+									      __func__, ret);
+					}
+					mutex_unlock(&nfsd_mutex);
+				} else {
+					trace_nfsd_dynthread_trylock_fail(net, pool);
+				}
+			}
+			clear_bit(SP_TASK_STARTING, &pool->sp_flags);
+			break;
+		default:
+			break;
+		}
+		nfsd_file_net_dispose(nn);
+	}
+
+	atomic_dec(&nfsd_th_cnt);
+
+	/* Release the thread */
+	svc_exit_thread(rqstp);
+	if (have_mutex)
+		mutex_unlock(&nfsd_mutex);
+	return 0;
+}
+
+/*
+ * Set rq_status_counter back to an even value, indicating that the rqstp
+ * fields are no longer meaningful to a lockless reader. This pairs with the
+ * odd-valued store made once the request has been decoded, and must run on
+ * every return path that follows it so that the seq-lock like protocol used
+ * by nfsd_nl_rpc_status_get_dumpit() is not left permanently odd. The store
+ * also advances the counter so a concurrent reader detects the transition.
+ */
+static void nfsd_status_counter_set_idle(struct svc_rqst *rqstp)
+{
+	smp_store_release(&rqstp->rq_status_counter,
+			  (rqstp->rq_status_counter | 1) + 1);
+}
+
+/**
+ * nfsd_dispatch - Process an NFS or NFSACL or LOCALIO Request
+ * @rqstp: incoming request
+ *
+ * This RPC dispatcher integrates the NFS server's duplicate reply cache.
+ *
+ * Return values:
+ *  %0: Processing complete; do not send a Reply
+ *  %1: Processing complete; send Reply in rqstp->rq_res
+ */
+int nfsd_dispatch(struct svc_rqst *rqstp)
+{
+	struct nfsd_thread_local_info *ntli = rqstp->rq_private;
+	const struct svc_procedure *proc = rqstp->rq_procinfo;
+	__be32 *statp = rqstp->rq_accept_statp;
+	struct nfsd_cacherep *rp;
+	unsigned int start, len;
+	__be32 *nfs_reply;
+
+	/*
+	 * Give the xdr decoder a chance to change this if it wants
+	 * (necessary in the NFSv4.0 compound case)
+	 */
+	ntli->ntli_cachetype = proc->pc_cachetype;
+
+	/*
+	 * ->pc_decode advances the argument stream past the NFS
+	 * Call header, so grab the header's starting location and
+	 * size now for the call to nfsd_cache_lookup().
+	 */
+	start = xdr_stream_pos(&rqstp->rq_arg_stream);
+	len = xdr_stream_remaining(&rqstp->rq_arg_stream);
+	if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream))
+		goto out_decode_err;
+
+	/*
+	 * Release rq_status_counter setting it to an odd value after the rpc
+	 * request has been properly parsed. rq_status_counter is used to
+	 * notify the consumers if the rqstp fields are stable
+	 * (rq_status_counter is odd) or not meaningful (rq_status_counter
+	 * is even).
+	 */
+	smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1);
+
+	rp = NULL;
+	switch (nfsd_cache_lookup(rqstp, start, len, &rp)) {
+	case RC_DOIT:
+		break;
+	case RC_REPLY:
+		goto out_cached_reply;
+	case RC_DROPIT:
+		goto out_dropit;
+	}
+
+	nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0);
+	*statp = proc->pc_func(rqstp);
+	if (test_bit(RQ_DROPME, &rqstp->rq_flags))
+		goto out_update_drop;
+
+	if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream))
+		goto out_encode_err;
+
+	nfsd_cache_update(rqstp, rp, ntli->ntli_cachetype, nfs_reply);
+out_cached_reply:
+	nfsd_status_counter_set_idle(rqstp);
+	return 1;
+
+out_decode_err:
+	trace_nfsd_garbage_args_err(rqstp);
+	*statp = rpc_garbage_args;
+	return 1;
+
+out_update_drop:
+	nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
+out_dropit:
+	nfsd_status_counter_set_idle(rqstp);
+	return 0;
+
+out_encode_err:
+	trace_nfsd_cant_encode_err(rqstp);
+	nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
+	*statp = rpc_system_err;
+	nfsd_status_counter_set_idle(rqstp);
+	return 1;
+}
+
+/**
+ * nfssvc_decode_voidarg - Decode void arguments
+ * @rqstp: Server RPC transaction context
+ * @xdr: XDR stream positioned at arguments to decode
+ *
+ * Return values:
+ *   %false: Arguments were not valid
+ *   %true: Decoding was successful
+ */
+bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
+
+/**
+ * nfssvc_encode_voidres - Encode void results
+ * @rqstp: Server RPC transaction context
+ * @xdr: XDR stream into which to encode results
+ *
+ * Return values:
+ *   %false: Local error while encoding
+ *   %true: Encoding was successful
+ */
+bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	return true;
+}
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
new file mode 100644
index 000000000..019f0cc97
--- /dev/null
+++ b/fs/nfsd/nfsxdr.c
@@ -0,0 +1,677 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XDR support for nfsd
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/filelock.h>
+
+#include "vfs.h"
+#include "xdr.h"
+#include "auth.h"
+
+/*
+ * Sun convention: a sattr time-useconds field of one full second (an
+ * otherwise out-of-range value) means "set this time to the current
+ * server time." It's needed to make permissions checks for the "touch"
+ * program across NFSv2 mounts work correctly. See description of
+ * sattr in section 6.1 of "NFS Illustrated" by Brent Callaghan,
+ * Addison-Wesley, ISBN 0-201-32750-5
+ */
+#define NFS2_SATTR_SET_TO_SERVER_TIME	(1000000)
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static const u32 nfs_ftypes[] = {
+	NFNON,  NFCHR,  NFCHR, NFBAD,
+	NFDIR,  NFBAD,  NFBLK, NFBAD,
+	NFREG,  NFBAD,  NFLNK, NFBAD,
+	NFSOCK, NFBAD,  NFLNK, NFBAD,
+};
+
+
+/*
+ * Basic NFSv2 data types (RFC 1094 Section 2.3)
+ */
+
+/**
+ * svcxdr_encode_stat - Encode an NFSv2 status code
+ * @xdr: XDR stream
+ * @status: status value to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
+svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(status));
+	if (!p)
+		return false;
+	*p = status;
+
+	return true;
+}
+
+/**
+ * svcxdr_decode_fhandle - Decode an NFSv2 file handle
+ * @xdr: XDR stream positioned at an encoded NFSv2 FH
+ * @fhp: OUT: filled-in server file handle
+ *
+ * Return values:
+ *  %false: The encoded file handle was not valid
+ *  %true: @fhp has been initialized
+ */
+bool
+svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS_FHSIZE);
+	if (!p)
+		return false;
+	fh_init(fhp, NFS_FHSIZE);
+	memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE);
+	fhp->fh_handle.fh_size = NFS_FHSIZE;
+
+	return true;
+}
+
+static bool
+svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS_FHSIZE);
+	if (!p)
+		return false;
+	memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE);
+
+	return true;
+}
+
+static __be32 *
+encode_timeval(__be32 *p, const struct timespec64 *time)
+{
+	*p++ = cpu_to_be32((u32)time->tv_sec);
+	if (time->tv_nsec)
+		*p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC);
+	else
+		*p++ = xdr_zero;
+	return p;
+}
+
+static bool
+svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len)
+{
+	u32 size, i;
+	__be32 *p;
+	char *c;
+
+	if (xdr_stream_decode_u32(xdr, &size) < 0)
+		return false;
+	if (size == 0 || size > NFS_MAXNAMLEN)
+		return false;
+	p = xdr_inline_decode(xdr, size);
+	if (!p)
+		return false;
+
+	*len = size;
+	*name = (char *)p;
+	for (i = 0, c = *name; i < size; i++, c++)
+		if (*c == '\0' || *c == '/')
+			return false;
+
+	return true;
+}
+
+static bool
+svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp,
+			char **name, unsigned int *len)
+{
+	return svcxdr_decode_fhandle(xdr, fhp) &&
+		svcxdr_decode_filename(xdr, name, len);
+}
+
+static bool
+svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		    struct iattr *iap)
+{
+	u32 tmp1, tmp2;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT * 8);
+	if (!p)
+		return false;
+
+	iap->ia_valid = 0;
+
+	/*
+	 * Some Sun clients put 0xffff in the mode field when they
+	 * mean 0xffffffff.
+	 */
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
+		iap->ia_valid |= ATTR_MODE;
+		iap->ia_mode = tmp1;
+	}
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
+		iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
+	}
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
+		iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
+	}
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
+		iap->ia_valid |= ATTR_SIZE;
+		iap->ia_size = tmp1;
+	}
+
+	tmp1 = be32_to_cpup(p++);
+	tmp2 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+		/*
+		 * Range test here to prevent the multiplication from
+		 * wrapping to a valid (but incorrect) value on 32-bit
+		 * platforms.
+		 */
+		if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME)
+			return false;
+		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+		iap->ia_atime.tv_sec = tmp1;
+		iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
+		if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME)
+			iap->ia_valid &= ~ATTR_ATIME_SET;
+	}
+
+	tmp1 = be32_to_cpup(p++);
+	tmp2 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+		if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME)
+			return false;
+		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+		iap->ia_mtime.tv_sec = tmp1;
+		iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
+		if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME)
+			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
+	}
+
+	return true;
+}
+
+/**
+ * svcxdr_encode_fattr - Encode NFSv2 file attributes
+ * @rqstp: Context of a completed RPC transaction
+ * @xdr: XDR stream
+ * @fhp: File handle to encode
+ * @stat: Attributes to encode
+ *
+ * Return values:
+ *   %false: Send buffer space was exhausted
+ *   %true: Success
+ */
+bool
+svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		    const struct svc_fh *fhp, const struct kstat *stat)
+{
+	struct user_namespace *userns = nfsd_user_namespace(rqstp);
+	struct dentry *dentry = fhp->fh_dentry;
+	int type = stat->mode & S_IFMT;
+	struct timespec64 time;
+	__be32 *p;
+	u32 fsid;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 17);
+	if (!p)
+		return false;
+
+	*p++ = cpu_to_be32(nfs_ftypes[type >> 12]);
+	*p++ = cpu_to_be32((u32)stat->mode);
+	*p++ = cpu_to_be32((u32)stat->nlink);
+	*p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
+	*p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));
+
+	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN)
+		*p++ = cpu_to_be32(NFS_MAXPATHLEN);
+	else
+		*p++ = cpu_to_be32((u32) stat->size);
+	*p++ = cpu_to_be32((u32) stat->blksize);
+	if (S_ISCHR(type) || S_ISBLK(type))
+		*p++ = cpu_to_be32(new_encode_dev(stat->rdev));
+	else
+		*p++ = cpu_to_be32(0xffffffff);
+	*p++ = cpu_to_be32((u32)stat->blocks);
+
+	switch (fsid_source(fhp)) {
+	case FSIDSOURCE_FSID:
+		fsid = (u32)fhp->fh_export->ex_fsid;
+		break;
+	case FSIDSOURCE_UUID:
+		fsid = ((u32 *)fhp->fh_export->ex_uuid)[0];
+		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1];
+		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2];
+		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3];
+		break;
+	default:
+		fsid = new_encode_dev(stat->dev);
+		break;
+	}
+	*p++ = cpu_to_be32(fsid);
+
+	*p++ = cpu_to_be32((u32)stat->ino);
+	p = encode_timeval(p, &stat->atime);
+	time = stat->mtime;
+	lease_get_mtime(d_inode(dentry), &time);
+	p = encode_timeval(p, &time);
+	encode_timeval(p, &stat->ctime);
+
+	return true;
+}
+
+/*
+ * XDR decode functions
+ */
+
+bool
+nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_fhandle *args = rqstp->rq_argp;
+
+	return svcxdr_decode_fhandle(xdr, &args->fh);
+}
+
+bool
+nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_sattrargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_fhandle(xdr, &args->fh) &&
+		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_diropargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
+}
+
+bool
+nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_readargs *args = rqstp->rq_argp;
+	u32 totalcount;
+
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+	/* totalcount is ignored */
+	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
+		return false;
+
+	return true;
+}
+
+bool
+nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_writeargs *args = rqstp->rq_argp;
+	u32 beginoffset, totalcount;
+
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return false;
+	/* beginoffset is ignored */
+	if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+		return false;
+	/* totalcount is ignored */
+	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
+		return false;
+
+	/* opaque data */
+	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
+		return false;
+	if (args->len > NFS_MAXDATA)
+		return false;
+
+	return xdr_stream_subsegment(xdr, &args->payload, args->len);
+}
+
+bool
+nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_createargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs(xdr, &args->fh,
+				       &args->name, &args->len) &&
+		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_renameargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_diropargs(xdr, &args->ffh,
+				       &args->fname, &args->flen) &&
+		svcxdr_decode_diropargs(xdr, &args->tfh,
+					&args->tname, &args->tlen);
+}
+
+bool
+nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_linkargs *args = rqstp->rq_argp;
+
+	return svcxdr_decode_fhandle(xdr, &args->ffh) &&
+		svcxdr_decode_diropargs(xdr, &args->tfh,
+					&args->tname, &args->tlen);
+}
+
+bool
+nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_symlinkargs *args = rqstp->rq_argp;
+	struct kvec *head = rqstp->rq_arg.head;
+
+	if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
+		return false;
+	if (args->tlen == 0)
+		return false;
+
+	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
+	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
+	if (!args->first.iov_base)
+		return false;
+	return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
+}
+
+bool
+nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_readdirargs *args = rqstp->rq_argp;
+
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
+		return false;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return false;
+
+	return true;
+}
+
+/*
+ * XDR encode functions
+ */
+
+bool
+nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	return svcxdr_encode_stat(xdr, resp->status);
+}
+
+bool
+nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+bool
+nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_fhandle(xdr, &resp->fh))
+			return false;
+		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+bool
+nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_readlinkres *resp = rqstp->rq_resp;
+	struct kvec *head = rqstp->rq_res.head;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
+			return false;
+		svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0,
+					   resp->len);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+bool
+nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_readres *resp = rqstp->rq_resp;
+	struct kvec *head = rqstp->rq_res.head;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
+			return false;
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return false;
+		svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages,
+					   rqstp->rq_res.page_base,
+					   resp->count);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+bool
+nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_readdirres *resp = rqstp->rq_resp;
+	struct xdr_buf *dirlist = &resp->dirlist;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0,
+					   dirlist->len);
+		/* no more entries */
+		if (xdr_stream_encode_item_absent(xdr) < 0)
+			return false;
+		if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+bool
+nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd_statfsres *resp = rqstp->rq_resp;
+	struct kstatfs	*stat = &resp->stats;
+	__be32 *p;
+
+	if (!svcxdr_encode_stat(xdr, resp->status))
+		return false;
+	switch (resp->status) {
+	case nfs_ok:
+		p = xdr_reserve_space(xdr, XDR_UNIT * 5);
+		if (!p)
+			return false;
+		*p++ = cpu_to_be32(NFS_MAXDATA);
+		*p++ = cpu_to_be32(stat->f_bsize);
+		*p++ = cpu_to_be32(stat->f_blocks);
+		*p++ = cpu_to_be32(stat->f_bfree);
+		*p = cpu_to_be32(stat->f_bavail);
+		break;
+	}
+
+	return true;
+}
+
+/**
+ * nfssvc_encode_nfscookie - Encode a directory offset cookie
+ * @resp: readdir result context
+ * @offset: offset cookie to encode
+ *
+ * The buffer space for the offset cookie has already been reserved
+ * by svcxdr_encode_entry_common().
+ */
+void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)
+{
+	__be32 cookie = cpu_to_be32(offset);
+
+	if (!resp->cookie_offset)
+		return;
+
+	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
+			       sizeof(cookie));
+	resp->cookie_offset = 0;
+}
+
+static bool
+svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name,
+			   int namlen, loff_t offset, u64 ino)
+{
+	struct xdr_buf *dirlist = &resp->dirlist;
+	struct xdr_stream *xdr = &resp->xdr;
+
+	if (xdr_stream_encode_item_present(xdr) < 0)
+		return false;
+	/* fileid */
+	if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)
+		return false;
+	/* name */
+	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)
+		return false;
+	/* cookie */
+	resp->cookie_offset = dirlist->len;
+	if (xdr_stream_encode_u32(xdr, ~0U) < 0)
+		return false;
+
+	return true;
+}
+
+/**
+ * nfssvc_encode_entry - encode one NFSv2 READDIR entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ *   %0: Entry was successfully encoded.
+ *   %-EINVAL: An encoding problem occurred, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ *   - resp->xdr
+ *   - resp->common.err
+ *   - resp->cookie_offset
+ */
+int nfssvc_encode_entry(void *data, const char *name, int namlen,
+			loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = data;
+	struct nfsd_readdirres *resp = container_of(ccd,
+						    struct nfsd_readdirres,
+						    common);
+	unsigned int starting_length = resp->dirlist.len;
+
+	/* The offset cookie for the previous entry */
+	nfssvc_encode_nfscookie(resp, offset);
+
+	if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))
+		goto out_toosmall;
+
+	xdr_commit_encode(&resp->xdr);
+	resp->common.err = nfs_ok;
+	return 0;
+
+out_toosmall:
+	resp->cookie_offset = 0;
+	resp->common.err = nfserr_toosmall;
+	resp->dirlist.len = starting_length;
+	return -EINVAL;
+}
+
+/*
+ * XDR release functions
+ */
+void nfssvc_release_attrstat(struct svc_rqst *rqstp)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void nfssvc_release_diropres(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void nfssvc_release_readres(struct svc_rqst *rqstp)
+{
+	struct nfsd_readres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
diff --git a/fs/nfsd/pnfs.h b/fs/nfsd/pnfs.h
new file mode 100644
index 000000000..f7bee4dc5
--- /dev/null
+++ b/fs/nfsd/pnfs.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_NFSD_PNFS_H
+#define _FS_NFSD_PNFS_H 1
+
+#ifdef CONFIG_NFSD_V4
+#include <linux/exportfs.h>
+#include <linux/nfsd/export.h>
+
+#include "state.h"
+#include "xdr4.h"
+
+struct xdr_stream;
+
+/* Cap exponential backoff between fence retries at 3 minutes */
+#define	MAX_FENCE_DELAY		((unsigned int)(3 * 60 * HZ))
+
+struct nfsd4_deviceid_map {
+	struct list_head	hash;
+	u64			idx;
+	int			fsid_type;
+	u32			fsid[];
+};
+
+struct nfsd4_layout_ops {
+	u32		notify_types;
+	bool		disable_recalls;
+
+	__be32 (*proc_getdeviceinfo)(struct super_block *sb,
+			struct svc_rqst *rqstp,
+			struct nfs4_client *clp,
+			struct nfsd4_getdeviceinfo *gdevp);
+	__be32 (*encode_getdeviceinfo)(struct xdr_stream *xdr,
+			const struct nfsd4_getdeviceinfo *gdevp);
+
+	__be32 (*proc_layoutget)(struct svc_rqst *rqstp, struct inode *inode,
+			const struct svc_fh *fhp, struct nfsd4_layoutget *lgp);
+	__be32 (*encode_layoutget)(struct xdr_stream *xdr,
+			const struct nfsd4_layoutget *lgp);
+
+	__be32 (*proc_layoutcommit)(struct inode *inode,
+			struct svc_rqst *rqstp,
+			struct nfsd4_layoutcommit *lcp);
+
+	bool (*fence_client)(struct nfs4_layout_stateid *ls,
+			     struct nfsd_file *file);
+};
+
+extern const struct nfsd4_layout_ops *nfsd4_layout_ops[];
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+extern const struct nfsd4_layout_ops bl_layout_ops;
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+extern const struct nfsd4_layout_ops scsi_layout_ops;
+#endif
+#ifdef CONFIG_NFSD_FLEXFILELAYOUT
+extern const struct nfsd4_layout_ops ff_layout_ops;
+#endif
+
+__be32 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, stateid_t *stateid,
+		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp);
+__be32 nfsd4_insert_layout(struct nfsd4_layoutget *lgp,
+		struct nfs4_layout_stateid *ls);
+__be32 nfsd4_return_file_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp);
+__be32 nfsd4_return_client_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp);
+int nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
+		u32 device_generation);
+struct nfsd4_deviceid_map *nfsd4_find_devid_map(int idx);
+#endif /* CONFIG_NFSD_V4 */
+
+#ifdef CONFIG_NFSD_PNFS
+void nfsd4_setup_layout_type(struct svc_export *exp);
+void nfsd4_return_all_client_layouts(struct nfs4_client *);
+void nfsd4_return_all_file_layouts(struct nfs4_client *clp,
+		struct nfs4_file *fp);
+void nfsd4_close_layout(struct nfs4_layout_stateid *ls);
+int nfsd4_init_pnfs(void);
+void nfsd4_exit_pnfs(void);
+#else
+struct nfs4_client;
+struct nfs4_file;
+struct nfs4_layout_stateid;
+
+static inline void nfsd4_setup_layout_type(struct svc_export *exp)
+{
+}
+
+static inline void nfsd4_return_all_client_layouts(struct nfs4_client *clp)
+{
+}
+static inline void nfsd4_return_all_file_layouts(struct nfs4_client *clp,
+		struct nfs4_file *fp)
+{
+}
+static inline void nfsd4_close_layout(struct nfs4_layout_stateid *ls)
+{
+}
+static inline void nfsd4_exit_pnfs(void)
+{
+}
+static inline int nfsd4_init_pnfs(void)
+{
+	return 0;
+}
+#endif /* CONFIG_NFSD_PNFS */
+#endif /* _FS_NFSD_PNFS_H */
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
new file mode 100644
index 000000000..2d00a411c
--- /dev/null
+++ b/fs/nfsd/state.h
@@ -0,0 +1,991 @@
+/*
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson <andros@umich.edu>
+ *  
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *  
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef _NFSD4_STATE_H
+#define _NFSD4_STATE_H
+
+#include <crypto/md5.h>
+
+#include <linux/filelock.h>
+#include <linux/idr.h>
+#include <linux/refcount.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#include "nfsfh.h"
+#include "nfsd.h"
+
+typedef struct {
+	u32             cl_boot;
+	u32             cl_id;
+} clientid_t;
+
+typedef struct {
+	clientid_t	so_clid;
+	u32		so_id;
+} stateid_opaque_t;
+
+typedef struct {
+	u32                     si_generation;
+	stateid_opaque_t        si_opaque;
+} stateid_t;
+
+typedef struct {
+	stateid_t		cs_stid;
+#define NFS4_COPYNOTIFY_STID 2
+	unsigned char		cs_type;
+	refcount_t		cs_count;
+} copy_stateid_t;
+
+struct nfsd4_referring_call {
+	struct list_head	__list;
+
+	u32			rc_sequenceid;
+	u32			rc_slotid;
+};
+
+struct nfsd4_referring_call_list {
+	struct list_head	__list;
+
+	struct nfs4_sessionid	rcl_sessionid;
+	int			__nr_referring_calls;
+	struct list_head	rcl_referring_calls;
+};
+
+struct nfsd4_callback {
+	struct nfs4_client *cb_clp;
+	struct rpc_message cb_msg;
+#define NFSD4_CALLBACK_RUNNING		(0)
+#define NFSD4_CALLBACK_WAKE		(1)
+#define NFSD4_CALLBACK_REQUEUE		(2)
+	unsigned long cb_flags;
+	const struct nfsd4_callback_ops *cb_ops;
+	struct work_struct cb_work;
+	int cb_seq_status;
+	int cb_status;
+	int cb_held_slot;
+
+	int cb_nr_referring_call_list;
+	struct list_head cb_referring_call_list;
+};
+
+struct nfsd4_callback_ops {
+	bool (*prepare)(struct nfsd4_callback *cb);
+	int (*done)(struct nfsd4_callback *cb, struct rpc_task *task);
+	void (*release)(struct nfsd4_callback *cb);
+	uint32_t opcode;
+};
+
+/*
+ * A core object that represents a "common" stateid. These are generally
+ * embedded within the different (more specific) stateid objects and contain
+ * fields that are of general use to any stateid.
+ */
+struct nfs4_stid {
+	refcount_t		sc_count;
+
+	/* A new stateid is added to the cl_stateids idr early before it
+	 * is fully initialised.  Its sc_type is then zero.  After
+	 * initialisation the sc_type it set under cl_lock, and then
+	 * never changes.
+	 */
+#define SC_TYPE_OPEN		BIT(0)
+#define SC_TYPE_LOCK		BIT(1)
+#define SC_TYPE_DELEG		BIT(2)
+#define SC_TYPE_LAYOUT		BIT(3)
+#define SC_TYPE_COPY		BIT(4)
+	unsigned short		sc_type;
+
+/* nn->deleg_lock protects sc_status for delegation stateids.
+ * ->cl_lock protects sc_status for open and lock stateids.
+ * ->st_mutex also protect sc_status for open stateids.
+ * ->ls_lock protects sc_status for layout stateids.
+ */
+/*
+ * For an open stateid kept around *only* to process close replays.
+ * For deleg stateid, kept in idr until last reference is dropped.
+ */
+#define SC_STATUS_CLOSED	BIT(0)
+/* For a deleg stateid kept around only to process free_stateid's: */
+#define SC_STATUS_REVOKED	BIT(1)
+#define SC_STATUS_ADMIN_REVOKED	BIT(2)
+#define SC_STATUS_FREEABLE	BIT(3)
+#define SC_STATUS_FREED		BIT(4)
+	unsigned short		sc_status;
+
+	struct list_head	sc_cp_list;
+	stateid_t		sc_stateid;
+	spinlock_t		sc_lock;
+	struct nfs4_client	*sc_client;
+	struct nfs4_file	*sc_file;
+	struct svc_export	*sc_export;
+	void			(*sc_free)(struct nfs4_stid *);
+};
+
+/* Keep a list of stateids issued by the COPY_NOTIFY, associate it with the
+ * parent OPEN/LOCK/DELEG stateid.
+ */
+struct nfs4_cpntf_state {
+	copy_stateid_t		cp_stateid;
+	struct list_head	cp_list;	/* per parent nfs4_stid */
+	stateid_t		cp_p_stateid;	/* copy of parent's stateid */
+	clientid_t		cp_p_clid;	/* copy of parent's clid */
+	time64_t		cpntf_time;	/* last time stateid used */
+};
+
+/*
+ * RFC 7862 Section 4.8 states:
+ *
+ * | A copy offload stateid will be valid until either (A) the client
+ * | or server restarts or (B) the client returns the resource by
+ * | issuing an OFFLOAD_CANCEL operation or the client replies to a
+ * | CB_OFFLOAD operation.
+ *
+ * Because a client might not reply to a CB_OFFLOAD, or a reply
+ * might get lost due to connection loss, NFSD purges async copy
+ * state after a short period to prevent it from accumulating
+ * over time.
+ */
+#define NFSD_COPY_INITIAL_TTL 10
+
+struct nfs4_cb_fattr {
+	struct nfsd4_callback ncf_getattr;
+	u32 ncf_cb_status;
+
+	/* from CB_GETATTR reply */
+	u64 ncf_cb_change;
+	u64 ncf_cb_fsize;
+	struct timespec64 ncf_cb_mtime;
+	struct timespec64 ncf_cb_atime;
+
+	bool ncf_file_modified;
+	u64 ncf_initial_cinfo;
+	u64 ncf_cur_fsize;
+};
+
+/*
+ * FIXME: the current backchannel encoder can't handle a send buffer longer
+ *        than a single page (see bc_malloc/bc_free).
+ */
+#define NOTIFY4_EVENT_QUEUE_SIZE	3
+#define NOTIFY4_PAGE_ARRAY_SIZE		1
+
+struct nfsd_notify_event {
+	refcount_t	ne_ref;		// refcount
+	u32		ne_mask;	// FS_* mask from fsnotify callback
+	struct dentry	*ne_dentry;	// dentry reference to target
+	struct inode	*ne_target;	// inode overwritten by rename, or NULL
+	u32		ne_namelen;	// length of ne_name (old name for a rename)
+	u32		ne_newnamelen;	// length of new name (rename only), else 0
+	char		ne_name[];	// entry name, then new name (rename only)
+};
+
+/*
+ * For a rename, the new name is snapshotted at event-alloc time and stored
+ * immediately after the (NUL-terminated) old name in ne_name[]. ne_dentry can
+ * be renamed again before the CB_NOTIFY work runs, so the new name must not be
+ * read from the live dentry at encode time.
+ */
+static inline char *nfsd_notify_event_newname(struct nfsd_notify_event *ne)
+{
+	return ne->ne_name + ne->ne_namelen + 1;
+}
+
+static inline struct nfsd_notify_event *nfsd_notify_event_get(struct nfsd_notify_event *ne)
+{
+	refcount_inc(&ne->ne_ref);
+	return ne;
+}
+
+static inline void nfsd_notify_event_put(struct nfsd_notify_event *ne)
+{
+	if (refcount_dec_and_test(&ne->ne_ref)) {
+		iput(ne->ne_target);
+		dput(ne->ne_dentry);
+		kfree(ne);
+	}
+}
+
+/*
+ * Represents a directory delegation. The callback is for handling CB_NOTIFYs.
+ * As notifications from fsnotify come in, allocate a new event, take the ncn_lock,
+ * and add it to the ncn_evt queue. The CB_NOTIFY prepare handler will take the
+ * lock, clean out the list and process it.
+ */
+struct nfsd4_cb_notify {
+	spinlock_t			ncn_lock;	// protects the evt queue and count
+	int				ncn_evt_cnt;	// count of events in ncn_evt
+	int				ncn_nf_cnt;	// count of valid entries in ncn_nf
+	struct nfsd_notify_event	*ncn_evt[NOTIFY4_EVENT_QUEUE_SIZE]; // list of events
+	struct page			*ncn_pages[NOTIFY4_PAGE_ARRAY_SIZE]; // for encoding
+	struct notify4			*ncn_nf;	// array of notify4's to be sent
+	bool				ncn_encode_err;	// did encoding fail?
+	struct nfsd4_callback		ncn_cb;		// notify4 callback
+};
+
+/*
+ * Represents a delegation stateid. The nfs4_client holds references to these
+ * and they are put when it is being destroyed or when the delegation is
+ * returned by the client:
+ *
+ * o 1 reference as long as a delegation is still in force (taken when it's
+ *   alloc'd, put when it's returned or revoked)
+ *
+ * o 1 reference as long as a recall rpc is in progress (taken when the lease
+ *   is broken, put when the rpc exits)
+ *
+ * o 1 more ephemeral reference for each nfsd thread currently doing something
+ *   with that delegation without holding the cl_lock
+ *
+ * If the server attempts to recall a delegation and the client doesn't do so
+ * before a timeout, the server may also revoke the delegation. In that case,
+ * the object will either be destroyed (v4.0) or moved to a per-client list of
+ * revoked delegations (v4.1+).
+ *
+ * This object is a superset of the nfs4_stid.
+ */
+struct nfs4_delegation {
+	struct nfs4_stid	dl_stid; /* must be first field */
+	struct list_head	dl_perfile;
+	struct list_head	dl_perclnt;
+	struct list_head	dl_recall_lru;  /* delegation recalled */
+	struct nfs4_clnt_odstate *dl_clnt_odstate;
+	time64_t		dl_time;
+	u32			dl_type;
+	/* For recall: */
+	int			dl_retries;
+	struct nfsd4_callback	dl_recall;
+	bool			dl_recalled;
+	bool			dl_written;
+	bool			dl_setattr;
+
+	union {
+		/* for CB_GETATTR */
+		struct nfs4_cb_fattr    dl_cb_fattr;
+		/* for CB_NOTIFY */
+		struct nfsd4_cb_notify	dl_cb_notify;
+	};
+
+	/* For delegated timestamps */
+	struct timespec64	dl_atime;
+	struct timespec64	dl_mtime;
+	struct timespec64	dl_ctime;
+
+	/* For dir delegations */
+	u32			dl_notify_mask;
+	u32			dl_child_attrs[2];
+	u32			dl_dir_attrs[2];
+};
+
+static inline bool deleg_is_read(u32 dl_type)
+{
+	return (dl_type == OPEN_DELEGATE_READ || dl_type == OPEN_DELEGATE_READ_ATTRS_DELEG);
+}
+
+static inline bool deleg_is_write(u32 dl_type)
+{
+	return (dl_type == OPEN_DELEGATE_WRITE || dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG);
+}
+
+static inline bool deleg_attrs_deleg(u32 dl_type)
+{
+	return dl_type == OPEN_DELEGATE_READ_ATTRS_DELEG ||
+	       dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG;
+}
+
+bool nfsd4_vet_deleg_time(struct timespec64 *cb, const struct timespec64 *orig,
+			  const struct timespec64 *now);
+
+#define cb_to_delegation(cb) \
+	container_of(cb, struct nfs4_delegation, dl_recall)
+
+/* client delegation callback info */
+struct nfs4_cb_conn {
+	/* SETCLIENTID info */
+	struct sockaddr_storage	cb_addr;
+	struct sockaddr_storage	cb_saddr;
+	size_t			cb_addrlen;
+	u32                     cb_prog; /* used only in 4.0 case;
+					    per-session otherwise */
+	u32                     cb_ident;	/* minorversion 0 only */
+	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */
+};
+
+static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_delegation, dl_stid);
+}
+
+/* Maximum number of slots per session.  This is for sanity-check only.
+ * It could be increased if we had a mechanism to shutdown misbehaving clients.
+ * A large number can be needed to get good throughput on high-latency servers.
+ */
+#define NFSD_MAX_SLOTS_PER_SESSION	2048
+/* Maximum  session per slot cache size */
+#define NFSD_SLOT_CACHE_SIZE		2048
+/* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
+#define NFSD_CACHE_SIZE_SLOTS_PER_SESSION	32
+#define NFSD_MAX_MEM_PER_SESSION  \
+		(NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)
+
+struct nfsd4_slot {
+	u32	sl_seqid;
+	__be32	sl_status;
+	struct svc_cred sl_cred;
+	u32	sl_index;
+	u32	sl_datalen;
+	u16	sl_opcnt;
+	u16	sl_generation;
+#define NFSD4_SLOT_INUSE	(1 << 0)
+#define NFSD4_SLOT_CACHETHIS	(1 << 1)
+#define NFSD4_SLOT_INITIALIZED	(1 << 2)
+#define NFSD4_SLOT_CACHED	(1 << 3)
+#define NFSD4_SLOT_REUSED	(1 << 4)
+	u8	sl_flags;
+	char	sl_data[];
+};
+
+struct nfsd4_channel_attrs {
+	u32		headerpadsz;
+	u32		maxreq_sz;
+	u32		maxresp_sz;
+	u32		maxresp_cached;
+	u32		maxops;
+	u32		maxreqs;
+	u32		nr_rdma_attrs;
+	u32		rdma_attrs;
+};
+
+struct nfsd4_cb_sec {
+	u32	flavor; /* (u32)(-1) used to mean "no valid flavor" */
+	kuid_t	uid;
+	kgid_t	gid;
+};
+
+struct nfsd4_create_session {
+	clientid_t			clientid;
+	struct nfs4_sessionid		sessionid;
+	u32				seqid;
+	u32				flags;
+	struct nfsd4_channel_attrs	fore_channel;
+	struct nfsd4_channel_attrs	back_channel;
+	u32				callback_prog;
+	struct nfsd4_cb_sec		cb_sec;
+};
+
+struct nfsd4_backchannel_ctl {
+	u32	bc_cb_program;
+	struct nfsd4_cb_sec		bc_cb_sec;
+};
+
+struct nfsd4_bind_conn_to_session {
+	struct nfs4_sessionid		sessionid;
+	u32				dir;
+};
+
+/* The single slot clientid cache structure */
+struct nfsd4_clid_slot {
+	u32				sl_seqid;
+	__be32				sl_status;
+	struct nfsd4_create_session	sl_cr_ses;
+};
+
+struct nfsd4_conn {
+	struct list_head cn_persession;
+	struct svc_xprt *cn_xprt;
+	struct svc_xpt_user cn_xpt_user;
+	struct nfsd4_session *cn_session;
+/* CDFC4_FORE, CDFC4_BACK: */
+	unsigned char cn_flags;
+};
+
+/* Maximum number of slots that nfsd will use in the backchannel */
+#define NFSD_BC_SLOT_TABLE_SIZE		(sizeof(u32) * 8)
+
+/*
+ * Representation of a v4.1+ session. These are refcounted in a similar fashion
+ * to the nfs4_client. References are only taken when the server is actively
+ * working on the object (primarily during the processing of compounds).
+ */
+struct nfsd4_session {
+	atomic_t		se_ref;
+	spinlock_t		se_lock;
+	u32			se_cb_slot_avail; /* bitmap of available slots */
+	u32			se_cb_highest_slot;	/* highest slot client wants */
+	u32			se_cb_prog;
+	struct list_head	se_hash;	/* hash by sessionid */
+	struct list_head	se_perclnt;
+	struct list_head	se_all_sessions;/* global list of sessions */
+	struct nfs4_client	*se_client;
+	struct nfs4_sessionid	se_sessionid;
+	struct nfsd4_channel_attrs se_fchannel;
+	struct nfsd4_cb_sec	se_cb_sec;
+	struct list_head	se_conns;
+	u32			se_cb_seq_nr[NFSD_BC_SLOT_TABLE_SIZE];
+	struct xarray		se_slots;	/* forward channel slots */
+	u16			se_slot_gen;
+	bool			se_dead;
+	u32			se_target_maxslots;
+	struct rcu_head		rcu_head;
+};
+
+/* formatted contents of nfs4_sessionid */
+struct nfsd4_sessionid {
+	clientid_t	clientid;
+	u32		sequence;
+	u32		reserved;
+};
+
+/* Length of MD5 digest as hex, plus terminating '\0' */
+#define HEXDIR_LEN	(2 * MD5_DIGEST_SIZE + 1)
+
+/*
+ *       State                Meaning                  Where set
+ * --------------------------------------------------------------------------
+ * | NFSD4_ACTIVE      | Confirmed, active    | Default                     |
+ * |------------------- ----------------------------------------------------|
+ * | NFSD4_COURTESY    | Courtesy state.      | nfs4_get_client_reaplist    |
+ * |                   | Lease/lock/share     |                             |
+ * |                   | reservation conflict |                             |
+ * |                   | can cause Courtesy   |                             |
+ * |                   | client to be expired |                             |
+ * |------------------------------------------------------------------------|
+ * | NFSD4_EXPIRABLE   | Courtesy client to be| nfs4_laundromat             |
+ * |                   | expired by Laundromat| try_to_expire_client        |
+ * |                   | due to conflict      |                             |
+ * |------------------------------------------------------------------------|
+ */
+enum {
+	NFSD4_ACTIVE = 0,
+	NFSD4_COURTESY,
+	NFSD4_EXPIRABLE,
+};
+
+/*
+ * struct nfs4_client - one per client.  Clientids live here.
+ *
+ * The initial object created by an NFS client using SETCLIENTID (for NFSv4.0)
+ * or EXCHANGE_ID (for NFSv4.1+). These objects are refcounted and timestamped.
+ * Each nfsd_net_ns object contains a set of these and they are tracked via
+ * short and long form clientid. They are hashed and searched for under the
+ * per-nfsd_net client_lock spinlock.
+ *
+ * References to it are only held during the processing of compounds, and in
+ * certain other operations. In their "resting state" they have a refcount of
+ * 0. If they are not renewed within a lease period, they become eligible for
+ * destruction by the laundromat.
+ *
+ * These objects can also be destroyed if the client sends certain forms of
+ * SETCLIENTID or EXCHANGE_ID operations.
+ *
+ * Care is taken *not* to do this however when the objects have an elevated
+ * refcount.
+ *
+ * o Each nfs4_client is hashed by clientid
+ *
+ * o Each nfs4_clients is also hashed by name (the opaque quantity initially
+ *   sent by the client to identify itself).
+ *
+ * o cl_perclient list is used to ensure no dangling stateowner references
+ *   when we expire the nfs4_client
+ */
+struct nfs4_client {
+	struct list_head	cl_idhash; 	/* hash by cl_clientid.id */
+	struct rb_node		cl_namenode;	/* link into by-name trees */
+	struct list_head	*cl_ownerstr_hashtbl;
+	struct list_head	cl_openowners;
+	struct idr		cl_stateids;	/* stateid lookup */
+	struct list_head	cl_delegations;
+	struct list_head	cl_revoked;	/* unacknowledged, revoked 4.1 state */
+	struct list_head        cl_lru;         /* tail queue */
+#ifdef CONFIG_NFSD_PNFS
+	struct list_head	cl_lo_states;	/* outstanding layout states */
+	bool			cl_fence_retry_warn;
+#endif
+	struct xdr_netobj	cl_name; 	/* id generated by client */
+	nfs4_verifier		cl_verifier; 	/* generated by client */
+	time64_t		cl_time;	/* time of last lease renewal */
+	struct sockaddr_storage	cl_addr; 	/* client ipaddress */
+	bool			cl_mach_cred;	/* SP4_MACH_CRED in force */
+	struct svc_cred		cl_cred; 	/* setclientid principal */
+	clientid_t		cl_clientid;	/* generated by server */
+	nfs4_verifier		cl_confirm;	/* generated by server */
+	u32			cl_minorversion;
+	atomic_t		cl_admin_revoked; /* count of admin-revoked states */
+	/* NFSv4.1 client implementation id: */
+	struct xdr_netobj	cl_nii_domain;
+	struct xdr_netobj	cl_nii_name;
+	struct timespec64	cl_nii_time;
+
+	/* for v4.0 and v4.1 callbacks: */
+	struct nfs4_cb_conn	cl_cb_conn;
+#define NFSD4_CLIENT_CB_UPDATE		(0)
+#define NFSD4_CLIENT_CB_KILL		(1)
+#define NFSD4_CLIENT_STABLE		(2)	/* client on stable storage */
+#define NFSD4_CLIENT_RECLAIM_COMPLETE	(3)	/* reclaim_complete done */
+#define NFSD4_CLIENT_CONFIRMED		(4)	/* client is confirmed */
+#define NFSD4_CLIENT_UPCALL_LOCK	(5)	/* upcall serialization */
+#define NFSD4_CLIENT_CB_FLAG_MASK	(1 << NFSD4_CLIENT_CB_UPDATE | \
+					 1 << NFSD4_CLIENT_CB_KILL)
+	unsigned long		cl_flags;
+
+	struct workqueue_struct *cl_callback_wq;
+	const struct cred	*cl_cb_cred;
+	struct rpc_clnt		*cl_cb_client;
+	u32			cl_cb_ident;
+#define NFSD4_CB_UP		0
+#define NFSD4_CB_UNKNOWN	1
+#define NFSD4_CB_DOWN		2
+#define NFSD4_CB_FAULT		3
+	int			cl_cb_state;
+	struct nfsd4_callback	cl_cb_null;
+	struct nfsd4_session	__rcu *cl_cb_session;
+
+	/* for all client information that callback code might need: */
+	spinlock_t		cl_lock;
+
+	/* for nfs41 */
+	struct list_head	cl_sessions;
+	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */
+	u32			cl_exchange_flags;
+	/* number of rpc's in progress over an associated session: */
+	atomic_t		cl_rpc_users;
+	struct nfsdfs_client	cl_nfsdfs;
+	struct nfs4_op_map      cl_spo_must_allow;
+
+	/* debugging info directory under nfsd/clients/ : */
+	struct dentry		*cl_nfsd_dentry;
+	/* 'info' file within that directory. Ref is not counted,
+	 * but will remain valid iff cl_nfsd_dentry != NULL
+	 */
+	struct dentry		*cl_nfsd_info_dentry;
+
+	struct rpc_wait_queue	cl_cb_waitq;	/* backchannel callers may */
+						/* wait here for slots */
+	struct net		*net;
+	struct list_head	async_copies;	/* list of async copies */
+	spinlock_t		async_lock;	/* lock for async copies */
+	atomic_t		cl_cb_inflight;	/* Outstanding callbacks */
+
+	unsigned int		cl_state;
+	atomic_t		cl_delegs_in_recall;
+
+	struct nfsd4_cb_recall_any	*cl_ra;
+	time64_t		cl_ra_time;
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	struct xarray		cl_dev_fences;
+	struct mutex		cl_fence_mutex;
+#endif
+};
+
+/* struct nfs4_client_reset
+ * one per old client. Populates reset_str_hashtbl. Filled from conf_id_hashtbl
+ * upon lease reset, or from upcall to state_daemon (to read in state
+ * from non-volitile storage) upon reboot.
+ */
+struct nfs4_client_reclaim {
+	struct list_head	cr_strhash;	/* hash by cr_name */
+	struct nfs4_client	*cr_clp;	/* pointer to associated clp */
+	struct xdr_netobj	cr_name;	/* recovery dir name */
+	struct xdr_netobj	cr_princhash;
+};
+
+/*
+ * REPLAY_ISIZE is sized for an OPEN response with delegation:
+ *   4(status) + 8(stateid) + 20(changeinfo) + 4(rflags) +
+ *   8(verifier) + 4(deleg. type) + 8(deleg. stateid) +
+ *   4(deleg. recall flag) + 20(deleg. space limit) +
+ *   ~32(deleg. ace) = 112 bytes
+ *
+ * Some responses can exceed this. A LOCK denial includes the conflicting
+ * lock owner, which can be up to 1024 bytes (NFS4_OPAQUE_LIMIT). When a
+ * response exceeds REPLAY_ISIZE, a buffer is dynamically allocated. If
+ * that allocation fails, only rp_status is saved. Enlarging this constant
+ * increases the size of every nfs4_stateowner.
+ */
+
+#define NFSD4_REPLAY_ISIZE       112 
+
+/*
+ * Replay buffer, where the result of the last seqid-mutating operation 
+ * is cached. 
+ */
+struct nfs4_replay {
+	__be32			rp_status;
+	unsigned int		rp_buflen;
+	char			*rp_buf; /* rp_ibuf or kmalloc'd */
+	struct knfsd_fh		rp_openfh;
+	int			rp_locked;
+	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
+};
+
+extern void nfs4_replay_free_cache(struct nfs4_replay *rp);
+
+struct nfs4_stateowner;
+
+struct nfs4_stateowner_operations {
+	void (*so_unhash)(struct nfs4_stateowner *);
+	void (*so_free)(struct nfs4_stateowner *);
+};
+
+/*
+ * A core object that represents either an open or lock owner. The object and
+ * lock owner objects have one of these embedded within them. Refcounts and
+ * other fields common to both owner types are contained within these
+ * structures.
+ */
+struct nfs4_stateowner {
+	struct list_head			so_strhash;
+	struct list_head			so_stateids;
+	struct nfs4_client			*so_client;
+	const struct nfs4_stateowner_operations	*so_ops;
+	/* after increment in nfsd4_bump_seqid, represents the next
+	 * sequence id expected from the client: */
+	atomic_t				so_count;
+	u32					so_seqid;
+	struct xdr_netobj			so_owner; /* open owner name */
+	struct nfs4_replay			so_replay;
+	bool					so_is_open_owner;
+};
+
+/*
+ * When a file is opened, the client provides an open state owner opaque string
+ * that indicates the "owner" of that open. These objects are refcounted.
+ * References to it are held by each open state associated with it. This object
+ * is a superset of the nfs4_stateowner struct.
+ */
+struct nfs4_openowner {
+	struct nfs4_stateowner	oo_owner; /* must be first field */
+	struct list_head        oo_perclient;
+	/*
+	 * We keep around openowners a little while after last close,
+	 * which saves clients from having to confirm, and allows us to
+	 * handle close replays if they come soon enough.  The close_lru
+	 * is a list of such openowners, to be reaped by the laundromat
+	 * thread eventually if they remain unused:
+	 */
+	struct list_head	oo_close_lru;
+	struct nfs4_ol_stateid *oo_last_closed_stid;
+	time64_t		oo_time; /* time of placement on so_close_lru */
+#define NFS4_OO_CONFIRMED   1
+	unsigned char		oo_flags;
+};
+
+/*
+ * Represents a generic "lockowner". Similar to an openowner. References to it
+ * are held by the lock stateids that are created on its behalf. This object is
+ * a superset of the nfs4_stateowner struct.
+ */
+struct nfs4_lockowner {
+	struct nfs4_stateowner	lo_owner;	/* must be first element */
+	struct list_head	lo_blocked;	/* blocked file_locks */
+};
+
+static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so)
+{
+	return container_of(so, struct nfs4_openowner, oo_owner);
+}
+
+static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
+{
+	return container_of(so, struct nfs4_lockowner, lo_owner);
+}
+
+/*
+ * Per-client state indicating no. of opens and outstanding delegations
+ * on a file from a particular client.'od' stands for 'open & delegation'
+ */
+struct nfs4_clnt_odstate {
+	struct nfs4_client	*co_client;
+	struct nfs4_file	*co_file;
+	struct list_head	co_perfile;
+	refcount_t		co_odcount;
+};
+
+/*
+ * nfs4_file: a file opened by some number of (open) nfs4_stateowners.
+ *
+ * These objects are global. nfsd keeps one instance of a nfs4_file per
+ * filehandle (though it may keep multiple file descriptors for each). Each
+ * inode can have multiple filehandles associated with it, so there is
+ * (potentially) a many to one relationship between this struct and struct
+ * inode.
+ */
+struct nfs4_file {
+	refcount_t		fi_ref;
+	struct inode *		fi_inode;
+	bool			fi_aliased;
+	spinlock_t		fi_lock;
+	struct rhlist_head	fi_rlist;
+	struct list_head        fi_stateids;
+	union {
+		struct list_head	fi_delegations;
+		struct rcu_head		fi_rcu;
+	};
+	struct list_head	fi_clnt_odstate;
+	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
+	struct nfsd_file	*fi_fds[3];
+	/*
+	 * Each open or lock stateid contributes 0-4 to the counts
+	 * below depending on which bits are set in st_access_bitmap:
+	 *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set
+	 *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set
+	 *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.
+	 */
+	atomic_t		fi_access[2];
+	u32			fi_share_deny;
+	struct nfsd_file __rcu	*fi_deleg_file;
+	struct nfsd_file	*fi_rdeleg_file;
+	int			fi_delegees;
+	struct knfsd_fh		fi_fhandle;
+	bool			fi_had_conflict;
+#ifdef CONFIG_NFSD_PNFS
+	struct list_head	fi_lo_states;
+	atomic_t		fi_lo_recalls;
+#endif
+};
+
+/*
+ * A generic struct representing either a open or lock stateid. The nfs4_client
+ * holds a reference to each of these objects, and they in turn hold a
+ * reference to their respective stateowners. The client's reference is
+ * released in response to a close or unlock (depending on whether it's an open
+ * or lock stateid) or when the client is being destroyed.
+ *
+ * In the case of v4.0 open stateids, these objects are preserved for a little
+ * while after close in order to handle CLOSE replays. Those are eventually
+ * reclaimed via a LRU scheme by the laundromat.
+ *
+ * This object is a superset of the nfs4_stid. "ol" stands for "Open or Lock".
+ * Better suggestions welcome.
+ */
+struct nfs4_ol_stateid {
+	struct nfs4_stid		st_stid;
+	struct list_head		st_perfile;
+	struct list_head		st_perstateowner;
+	struct list_head		st_locks;
+	struct nfs4_stateowner		*st_stateowner;
+	struct nfs4_clnt_odstate	*st_clnt_odstate;
+/*
+ * These bitmasks use 3 separate bits for READ, ALLOW, and BOTH; see the
+ * comment above bmap_to_share_mode() for explanation:
+ */
+	unsigned char			st_access_bmap;
+	unsigned char			st_deny_bmap;
+	struct nfs4_ol_stateid		*st_openstp;
+	struct mutex			st_mutex;
+};
+
+static inline struct nfs4_ol_stateid *openlockstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_ol_stateid, st_stid);
+}
+
+struct nfs4_layout_stateid {
+	struct nfs4_stid		ls_stid;
+	struct list_head		ls_perclnt;
+	struct list_head		ls_perfile;
+	spinlock_t			ls_lock;
+	struct list_head		ls_layouts;
+	u32				ls_layout_type;
+	struct nfsd_file		*ls_file;
+	struct nfsd4_callback		ls_recall;
+	stateid_t			ls_recall_sid;
+	bool				ls_recalled;
+	struct mutex			ls_mutex;
+
+	struct delayed_work		ls_fence_work;
+	unsigned int			ls_fence_delay;
+	bool				ls_fenced;
+	bool				ls_fence_inflight;
+};
+
+static inline struct nfs4_layout_stateid *layoutstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_layout_stateid, ls_stid);
+}
+
+/* flags for preprocess_seqid_op() */
+#define RD_STATE	        0x00000010
+#define WR_STATE	        0x00000020
+
+enum nfsd4_cb_op {
+	NFSPROC4_CLNT_CB_NULL = 0,
+	NFSPROC4_CLNT_CB_RECALL,
+	NFSPROC4_CLNT_CB_LAYOUT,
+	NFSPROC4_CLNT_CB_OFFLOAD,
+	NFSPROC4_CLNT_CB_SEQUENCE,
+	NFSPROC4_CLNT_CB_NOTIFY_LOCK,
+	NFSPROC4_CLNT_CB_RECALL_ANY,
+	NFSPROC4_CLNT_CB_GETATTR,
+	NFSPROC4_CLNT_CB_NOTIFY,
+};
+
+/* Returns true iff a is later than b: */
+static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
+{
+	return (s32)(a->si_generation - b->si_generation) > 0;
+}
+
+/*
+ * When a client tries to get a lock on a file, we set one of these objects
+ * on the blocking lock. When the lock becomes free, we can then issue a
+ * CB_NOTIFY_LOCK to the server.
+ */
+struct nfsd4_blocked_lock {
+	struct list_head	nbl_list;
+	struct list_head	nbl_lru;
+	time64_t		nbl_time;
+	struct file_lock	nbl_lock;
+	struct knfsd_fh		nbl_fh;
+	struct nfsd4_callback	nbl_cb;
+	struct kref		nbl_kref;
+};
+
+struct nfsd4_compound_state;
+struct nfsd_net;
+struct nfsd4_copy;
+struct nfsd4_async_copy;
+
+extern __be32 nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
+		stateid_t *stateid, int flags, struct nfsd_file **filp,
+		struct nfs4_stid **cstid);
+__be32 nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
+			    stateid_t *stateid, unsigned short typemask,
+			    unsigned short statusmask,
+			    struct nfs4_stid **s, struct nfsd_net *nn);
+struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
+				  void (*sc_free)(struct nfs4_stid *));
+struct nfsd4_async_copy *nfs4_alloc_copy_stid(struct nfs4_client *clp);
+struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
+			struct nfs4_stid *p_stid);
+void nfs4_put_stid(struct nfs4_stid *s);
+void nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid);
+void nfs4_remove_reclaim_record(struct nfs4_client_reclaim *, struct nfsd_net *);
+extern void nfs4_release_reclaim(struct nfsd_net *);
+extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(struct xdr_netobj name,
+							struct nfsd_net *nn);
+extern __be32 nfs4_check_open_reclaim(struct nfs4_client *);
+extern void nfsd4_probe_callback(struct nfs4_client *clp);
+extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
+extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
+extern void nfsd41_cb_referring_call(struct nfsd4_callback *cb,
+				     struct nfs4_sessionid *sessionid,
+				     u32 slotid, u32 seqno);
+extern void nfsd41_cb_destroy_referring_call_list(struct nfsd4_callback *cb);
+extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
+		const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
+extern bool nfsd4_run_cb(struct nfsd4_callback *cb);
+
+static inline void nfsd4_try_run_cb(struct nfsd4_callback *cb)
+{
+	if (!test_and_set_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags))
+		WARN_ON_ONCE(!nfsd4_run_cb(cb));
+}
+
+extern void nfsd4_shutdown_callback(struct nfs4_client *);
+extern void nfsd4_shutdown_copy(struct nfs4_client *clp);
+void nfsd4_put_client(struct nfs4_client *clp);
+void nfsd4_async_copy_reaper(struct nfsd_net *nn);
+bool nfsd4_has_active_async_copies(struct nfs4_client *clp);
+void nfsd_update_cmtime_attr(struct file *f, unsigned int flags);
+extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name,
+				struct xdr_netobj princhash, struct nfsd_net *nn);
+extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn);
+int nfsd_handle_dir_event(u32 mask, const struct inode *dir, const void *data,
+			  int data_type, const struct qstr *name);
+
+void put_nfs4_file(struct nfs4_file *fi);
+extern void nfs4_put_cpntf_state(struct nfsd_net *nn,
+				 struct nfs4_cpntf_state *cps);
+extern __be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+				 struct nfs4_client *clp,
+				 struct nfs4_cpntf_state **cps);
+static inline void get_nfs4_file(struct nfs4_file *fi)
+{
+	refcount_inc(&fi->fi_ref);
+}
+struct nfsd_file *find_any_file(struct nfs4_file *f);
+
+#ifdef CONFIG_NFSD_V4
+void nfsd4_revoke_states(struct nfsd_net *nn, struct super_block *sb);
+void nfsd4_revoke_export_states(struct nfsd_net *nn, const struct path *path);
+void nfsd4_cancel_copy_by_sb(struct net *net, struct super_block *sb);
+int nfsd_net_cb_init(struct nfsd_net *nn);
+void nfsd_net_cb_shutdown(struct nfsd_net *nn);
+#else
+static inline void nfsd4_revoke_states(struct nfsd_net *nn, struct super_block *sb)
+{
+}
+static inline void nfsd4_revoke_export_states(struct nfsd_net *nn,
+					      const struct path *path)
+{
+}
+static inline void nfsd4_cancel_copy_by_sb(struct net *net, struct super_block *sb)
+{
+}
+static inline int nfsd_net_cb_init(struct nfsd_net *nn)
+{
+	return 0;
+}
+static inline void nfsd_net_cb_shutdown(struct nfsd_net *nn)
+{
+}
+#endif
+
+/* grace period management */
+bool nfsd4_force_end_grace(struct nfsd_net *nn);
+
+/* nfs4recover operations */
+extern int nfsd4_client_tracking_init(struct net *net);
+extern void nfsd4_client_tracking_exit(struct net *net);
+extern void nfsd4_client_record_create(struct nfs4_client *clp);
+extern void nfsd4_client_record_remove(struct nfs4_client *clp);
+extern int nfsd4_client_record_check(struct nfs4_client *clp);
+extern void nfsd4_record_grace_done(struct nfsd_net *nn);
+
+static inline bool try_to_expire_client(struct nfs4_client *clp)
+{
+	cmpxchg(&clp->cl_state, NFSD4_COURTESY, NFSD4_EXPIRABLE);
+	return clp->cl_state == NFSD4_EXPIRABLE;
+}
+
+extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp,
+		struct dentry *dentry, struct nfs4_delegation **pdp);
+
+struct nfsd4_get_dir_delegation;
+struct nfs4_delegation *nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
+						struct nfsd4_get_dir_delegation *gdd,
+						struct nfsd_file *nf);
+#endif   /* NFSD4_STATE_H */
diff --git a/fs/nfsd/stats.c b/fs/nfsd/stats.c
new file mode 100644
index 000000000..f16559813
--- /dev/null
+++ b/fs/nfsd/stats.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * procfs-based user access to knfsd statistics
+ *
+ * /proc/net/rpc/nfsd
+ *
+ * Format:
+ *	rc <hits> <misses> <nocache>
+ *			Statistsics for the reply cache
+ *	fh <stale> <deprecated filehandle cache stats>
+ *			statistics for filehandle lookup
+ *	io <bytes-read> <bytes-written>
+ *			statistics for IO throughput
+ *	th <threads> <deprecated thread usage histogram stats>
+ *			number of threads
+ *	ra <deprecated ra-cache stats>
+ *
+ *	plus generic RPC stats (see net/sunrpc/stats.c)
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/sunrpc/stats.h>
+#include <net/net_namespace.h>
+
+#include "nfsd.h"
+#include "netns.h"
+#include "stats.h"
+
+static int nfsd_show(struct seq_file *seq, void *v)
+{
+	struct net *net = pde_data(file_inode(seq->file));
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	seq_printf(seq, "rc %lld %lld %lld\nfh %lld 0 0 0 0\nio %lld %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_HITS]),
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_MISSES]),
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_NOCACHE]),
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_FH_STALE]),
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_READ]),
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_WRITE]));
+
+	/* thread usage: */
+	seq_printf(seq, "th %u 0", atomic_read(&nfsd_th_cnt));
+
+	/* deprecated thread usage histogram stats */
+	for (i = 0; i < 10; i++)
+		seq_puts(seq, " 0.000");
+
+	/* deprecated ra-cache stats */
+	seq_puts(seq, "\nra 0 0 0 0 0 0 0 0 0 0 0 0\n");
+
+	/* show my rpc info */
+	svc_seq_show(seq, &nn->nfsd_svcstats);
+
+#ifdef CONFIG_NFSD_V4
+	/* Show count for individual nfsv4 operations */
+	/* Writing operation numbers 0 1 2 also for maintaining uniformity */
+	seq_printf(seq, "proc4ops %u", LAST_NFS4_OP + 1);
+	for (i = 0; i <= LAST_NFS4_OP; i++) {
+		seq_printf(seq, " %lld",
+			   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_NFS4_OP(i)]));
+	}
+	seq_printf(seq, "\nwdeleg_getattr %lld",
+		percpu_counter_sum_positive(&nn->cb_counter[OP_CB_GETATTR]));
+
+	seq_putc(seq, '\n');
+#endif
+
+	return 0;
+}
+
+DEFINE_PROC_SHOW_ATTRIBUTE(nfsd);
+
+struct proc_dir_entry *nfsd_proc_stat_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	return svc_proc_register(net, &nn->nfsd_svcstats, &nfsd_proc_ops);
+}
+
+void nfsd_proc_stat_shutdown(struct net *net)
+{
+	svc_proc_unregister(net, "nfsd");
+}
diff --git a/fs/nfsd/stats.h b/fs/nfsd/stats.h
new file mode 100644
index 000000000..aabfbb1a9
--- /dev/null
+++ b/fs/nfsd/stats.h
@@ -0,0 +1,140 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Statistics for NFS server.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+#ifndef _NFSD_STATS_H
+#define _NFSD_STATS_H
+
+#include <uapi/linux/nfsd/stats.h>
+#include <linux/percpu_counter.h>
+
+#include "export.h"
+#include "netns.h"
+
+struct proc_dir_entry *nfsd_proc_stat_init(struct net *net);
+void nfsd_proc_stat_shutdown(struct net *net);
+
+/**
+ * nfsd_stats_rc_hits_inc - Count a duplicate reply cache hit
+ * @nn: target network namespace
+ *
+ * These reply cache counters are updated once per RPC. Readers use
+ * percpu_counter_sum_positive(), so local batching does not affect
+ * read accuracy.
+ */
+static inline void nfsd_stats_rc_hits_inc(struct nfsd_net *nn)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_RC_HITS], 1);
+}
+
+/**
+ * nfsd_stats_rc_misses_inc - Count a duplicate reply cache miss
+ * @nn: target network namespace
+ *
+ * See nfsd_stats_rc_hits_inc() for batching rationale.
+ */
+static inline void nfsd_stats_rc_misses_inc(struct nfsd_net *nn)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_RC_MISSES], 1);
+}
+
+/**
+ * nfsd_stats_rc_nocache_inc - Count a request not cached in the reply cache
+ * @nn: target network namespace
+ *
+ * See nfsd_stats_rc_hits_inc() for batching rationale.
+ */
+static inline void nfsd_stats_rc_nocache_inc(struct nfsd_net *nn)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_RC_NOCACHE], 1);
+}
+
+static inline void nfsd_stats_fh_stale_inc(struct nfsd_net *nn,
+					   struct svc_export *exp)
+{
+	percpu_counter_inc(&nn->counter[NFSD_STATS_FH_STALE]);
+	if (exp && exp->ex_stats)
+		percpu_counter_inc(&exp->ex_stats->counter[EXP_STATS_FH_STALE]);
+}
+
+/**
+ * nfsd_stats_io_read_add - Count number of bytes for an NFS READ
+ * @nn: target network namespace
+ * @exp: target export
+ * @amount: byte count
+ *
+ * These counters are updated on every READ request. Readers use
+ * percpu_counter_sum_positive(), so local batching does not affect
+ * read accuracy.
+ */
+static inline void nfsd_stats_io_read_add(struct nfsd_net *nn,
+					  struct svc_export *exp, s64 amount)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_IO_READ], amount);
+	if (exp && exp->ex_stats)
+		percpu_counter_add_local(&exp->ex_stats->counter[EXP_STATS_IO_READ],
+					 amount);
+}
+
+/**
+ * nfsd_stats_io_write_add - Count number of bytes for an NFS WRITE
+ * @nn: target network namespace
+ * @exp: target export
+ * @amount: byte count
+ *
+ * These counters are updated on every WRITE request. Readers use
+ * percpu_counter_sum_positive(), so local batching does not affect
+ * read accuracy.
+ */
+static inline void nfsd_stats_io_write_add(struct nfsd_net *nn,
+					   struct svc_export *exp, s64 amount)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_IO_WRITE], amount);
+	if (exp && exp->ex_stats)
+		percpu_counter_add_local(&exp->ex_stats->counter[EXP_STATS_IO_WRITE],
+					 amount);
+}
+
+static inline void nfsd_stats_payload_misses_inc(struct nfsd_net *nn)
+{
+	percpu_counter_inc(&nn->counter[NFSD_STATS_PAYLOAD_MISSES]);
+}
+
+/**
+ * nfsd_stats_drc_mem_usage_add - Add memory used by a cache item
+ * @nn: target network namespace
+ * @amount: byte count
+ *
+ * percpu_counter_add_local() keeps updates on the per-CPU fast
+ * path. The sole reader, percpu_counter_sum_positive(), sums the
+ * per-CPU deltas, so batching locally does not lose accuracy.
+ */
+static inline void nfsd_stats_drc_mem_usage_add(struct nfsd_net *nn, s64 amount)
+{
+	percpu_counter_add_local(&nn->counter[NFSD_STATS_DRC_MEM_USAGE],
+				 amount);
+}
+
+/**
+ * nfsd_stats_drc_mem_usage_sub - Subtract memory used by a cache item
+ * @nn: target network namespace
+ * @amount: byte count
+ *
+ * See nfsd_stats_drc_mem_usage_add() for batching rationale.
+ */
+static inline void nfsd_stats_drc_mem_usage_sub(struct nfsd_net *nn, s64 amount)
+{
+	percpu_counter_sub_local(&nn->counter[NFSD_STATS_DRC_MEM_USAGE],
+				 amount);
+}
+
+#ifdef CONFIG_NFSD_V4
+static inline void nfsd_stats_cb_op_inc(struct nfsd_net *nn, u32 opcode)
+{
+	if (opcode >= OP_CB_GETATTR && opcode <= OP_CB_OFFLOAD)
+		percpu_counter_inc(&nn->cb_counter[opcode]);
+}
+#endif
+#endif /* _NFSD_STATS_H */
diff --git a/fs/nfsd/trace.c b/fs/nfsd/trace.c
new file mode 100644
index 000000000..f008b95ce
--- /dev/null
+++ b/fs/nfsd/trace.c
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
new file mode 100644
index 000000000..7d7a14831
--- /dev/null
+++ b/fs/nfsd/trace.h
@@ -0,0 +1,2780 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nfsd
+
+#if !defined(_NFSD_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _NFSD_TRACE_H
+
+#include <linux/tracepoint.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xprt.h>
+#include <trace/misc/fs.h>
+#include <trace/misc/fsnotify.h>
+#include <trace/misc/nfs.h>
+#include <trace/misc/sunrpc.h>
+
+#include "export.h"
+#include "nfsfh.h"
+#include "xdr4.h"
+#include "netns.h"
+
+#define NFSD_TRACE_PROC_CALL_FIELDS(r) \
+		__field(unsigned int, netns_ino) \
+		__field(u32, xid) \
+		__sockaddr(server, (r)->rq_xprt->xpt_locallen) \
+		__sockaddr(client, (r)->rq_xprt->xpt_remotelen)
+
+#define NFSD_TRACE_PROC_CALL_ASSIGNMENTS(r) \
+		do { \
+			struct svc_xprt *xprt = (r)->rq_xprt; \
+			__entry->netns_ino = SVC_NET(r)->ns.inum; \
+			__entry->xid = be32_to_cpu((r)->rq_xid); \
+			__assign_sockaddr(server, &xprt->xpt_local, \
+					  xprt->xpt_locallen); \
+			__assign_sockaddr(client, &xprt->xpt_remote, \
+					  xprt->xpt_remotelen); \
+		} while (0)
+
+#define NFSD_TRACE_PROC_RES_FIELDS(r) \
+		__field(unsigned int, netns_ino) \
+		__field(u32, xid) \
+		__field(unsigned long, status) \
+		__sockaddr(server, (r)->rq_xprt->xpt_locallen) \
+		__sockaddr(client, (r)->rq_xprt->xpt_remotelen)
+
+#define NFSD_TRACE_PROC_RES_ASSIGNMENTS(r, error) \
+		do { \
+			struct svc_xprt *xprt = (r)->rq_xprt; \
+			__entry->netns_ino = SVC_NET(r)->ns.inum; \
+			__entry->xid = be32_to_cpu((r)->rq_xid); \
+			__entry->status = be32_to_cpu(error); \
+			__assign_sockaddr(server, &xprt->xpt_local, \
+					  xprt->xpt_locallen); \
+			__assign_sockaddr(client, &xprt->xpt_remote, \
+					  xprt->xpt_remotelen); \
+		} while (0);
+
+DECLARE_EVENT_CLASS(nfsd_xdr_err_class,
+	TP_PROTO(
+		const struct svc_rqst *rqstp
+	),
+	TP_ARGS(rqstp),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(u32, xid)
+		__field(u32, vers)
+		__field(u32, proc)
+		__sockaddr(server, rqstp->rq_xprt->xpt_locallen)
+		__sockaddr(client, rqstp->rq_xprt->xpt_remotelen)
+	),
+	TP_fast_assign(
+		const struct svc_xprt *xprt = rqstp->rq_xprt;
+
+		__entry->netns_ino = xprt->xpt_net->ns.inum;
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->vers = rqstp->rq_vers;
+		__entry->proc = rqstp->rq_proc;
+		__assign_sockaddr(server, &xprt->xpt_local, xprt->xpt_locallen);
+		__assign_sockaddr(client, &xprt->xpt_remote, xprt->xpt_remotelen);
+	),
+	TP_printk("xid=0x%08x vers=%u proc=%u",
+		__entry->xid, __entry->vers, __entry->proc
+	)
+);
+
+#define DEFINE_NFSD_XDR_ERR_EVENT(name) \
+DEFINE_EVENT(nfsd_xdr_err_class, nfsd_##name##_err, \
+	TP_PROTO(const struct svc_rqst *rqstp), \
+	TP_ARGS(rqstp))
+
+DEFINE_NFSD_XDR_ERR_EVENT(garbage_args);
+DEFINE_NFSD_XDR_ERR_EVENT(cant_encode);
+
+DECLARE_EVENT_CLASS(nfsd_dynthread_class,
+	TP_PROTO(
+		const struct net *net,
+		const struct svc_pool *pool
+	),
+	TP_ARGS(net, pool),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(unsigned int, pool_id)
+		__field(unsigned int, nrthreads)
+		__field(unsigned int, nrthrmin)
+		__field(unsigned int, nrthrmax)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->pool_id = pool->sp_id;
+		__entry->nrthreads = pool->sp_nrthreads;
+		__entry->nrthrmin = pool->sp_nrthrmin;
+		__entry->nrthrmax = pool->sp_nrthrmax;
+	),
+	TP_printk("pool=%u nrthreads=%u nrthrmin=%u nrthrmax=%u",
+		__entry->pool_id, __entry->nrthreads,
+		__entry->nrthrmin, __entry->nrthrmax
+	)
+);
+
+#define DEFINE_NFSD_DYNTHREAD_EVENT(name) \
+DEFINE_EVENT(nfsd_dynthread_class, nfsd_dynthread_##name, \
+	TP_PROTO(const struct net *net, const struct svc_pool *pool), \
+	TP_ARGS(net, pool))
+
+DEFINE_NFSD_DYNTHREAD_EVENT(start);
+DEFINE_NFSD_DYNTHREAD_EVENT(kill);
+DEFINE_NFSD_DYNTHREAD_EVENT(trylock_fail);
+
+#define show_nfsd_may_flags(x)						\
+	__print_flags(x, "|",						\
+		{ NFSD_MAY_EXEC,		"EXEC" },		\
+		{ NFSD_MAY_WRITE,		"WRITE" },		\
+		{ NFSD_MAY_READ,		"READ" },		\
+		{ NFSD_MAY_SATTR,		"SATTR" },		\
+		{ NFSD_MAY_TRUNC,		"TRUNC" },		\
+		{ NFSD_MAY_NLM,			"NLM" },		\
+		{ NFSD_MAY_OWNER_OVERRIDE,	"OWNER_OVERRIDE" },	\
+		{ NFSD_MAY_LOCAL_ACCESS,	"LOCAL_ACCESS" },	\
+		{ NFSD_MAY_BYPASS_GSS_ON_ROOT,	"BYPASS_GSS_ON_ROOT" },	\
+		{ NFSD_MAY_NOT_BREAK_LEASE,	"NOT_BREAK_LEASE" },	\
+		{ NFSD_MAY_BYPASS_GSS,		"BYPASS_GSS" },		\
+		{ NFSD_MAY_READ_IF_EXEC,	"READ_IF_EXEC" },	\
+		{ NFSD_MAY_64BIT_COOKIE,	"64BIT_COOKIE" },	\
+		{ NFSD_MAY_LOCALIO,		"LOCALIO" })
+
+TRACE_EVENT(nfsd_compound,
+	TP_PROTO(
+		const struct svc_rqst *rqst,
+		const char *tag,
+		u32 taglen,
+		u32 opcnt
+	),
+	TP_ARGS(rqst, tag, taglen, opcnt),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, opcnt)
+		__string_len(tag, tag, taglen)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqst->rq_xid);
+		__entry->opcnt = opcnt;
+		__assign_str(tag);
+	),
+	TP_printk("xid=0x%08x opcnt=%u tag=%s",
+		__entry->xid, __entry->opcnt, __get_str(tag)
+	)
+)
+
+TRACE_EVENT(nfsd_compound_status,
+	TP_PROTO(u32 args_opcnt,
+		 u32 resp_opcnt,
+		 __be32 status,
+		 const char *name),
+	TP_ARGS(args_opcnt, resp_opcnt, status, name),
+	TP_STRUCT__entry(
+		__field(u32, args_opcnt)
+		__field(u32, resp_opcnt)
+		__field(int, status)
+		__string(name, name)
+	),
+	TP_fast_assign(
+		__entry->args_opcnt = args_opcnt;
+		__entry->resp_opcnt = resp_opcnt;
+		__entry->status = be32_to_cpu(status);
+		__assign_str(name);
+	),
+	TP_printk("op=%u/%u %s status=%d",
+		__entry->resp_opcnt, __entry->args_opcnt,
+		__get_str(name), __entry->status)
+)
+
+TRACE_EVENT(nfsd_compound_decode_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		u32 args_opcnt,
+		u32 resp_opcnt,
+		u32 opnum,
+		__be32 status
+	),
+	TP_ARGS(rqstp, args_opcnt, resp_opcnt, opnum, status),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_RES_FIELDS(rqstp)
+
+		__field(u32, args_opcnt)
+		__field(u32, resp_opcnt)
+		__field(u32, opnum)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_RES_ASSIGNMENTS(rqstp, status)
+
+		__entry->args_opcnt = args_opcnt;
+		__entry->resp_opcnt = resp_opcnt;
+		__entry->opnum = opnum;
+	),
+	TP_printk("op=%u/%u opnum=%u status=%lu",
+		__entry->resp_opcnt, __entry->args_opcnt,
+		__entry->opnum, __entry->status)
+);
+
+DECLARE_EVENT_CLASS(nfsd_compound_err_class,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		u32 opnum,
+		__be32 status
+	),
+	TP_ARGS(rqstp, opnum, status),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_RES_FIELDS(rqstp)
+
+		__field(u32, opnum)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_RES_ASSIGNMENTS(rqstp, status)
+
+		__entry->opnum = opnum;
+	),
+	TP_printk("opnum=%u status=%lu",
+		__entry->opnum, __entry->status)
+);
+
+#define DEFINE_NFSD_COMPOUND_ERR_EVENT(name)				\
+DEFINE_EVENT(nfsd_compound_err_class, nfsd_compound_##name##_err,	\
+	TP_PROTO(							\
+		const struct svc_rqst *rqstp,				\
+		u32 opnum,						\
+		__be32 status						\
+	),								\
+	TP_ARGS(rqstp, opnum, status))
+
+DEFINE_NFSD_COMPOUND_ERR_EVENT(op);
+DEFINE_NFSD_COMPOUND_ERR_EVENT(encode);
+
+#define show_fs_file_type(x) \
+	__print_symbolic(x, \
+		{ S_IFLNK,		"LNK" }, \
+		{ S_IFREG,		"REG" }, \
+		{ S_IFDIR,		"DIR" }, \
+		{ S_IFCHR,		"CHR" }, \
+		{ S_IFBLK,		"BLK" }, \
+		{ S_IFIFO,		"FIFO" }, \
+		{ S_IFSOCK,		"SOCK" })
+
+TRACE_EVENT_CONDITION(nfsd_fh_verify,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		umode_t type,
+		int access
+	),
+	TP_ARGS(rqstp, fhp, type, access),
+	TP_CONDITION(rqstp != NULL),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__sockaddr(server, rqstp->rq_xprt->xpt_locallen)
+		__sockaddr(client, rqstp->rq_xprt->xpt_remotelen)
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(const void *, inode)
+		__field(unsigned long, type)
+		__field(unsigned long, access)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = SVC_NET(rqstp)->ns.inum;
+		__assign_sockaddr(server, &rqstp->rq_xprt->xpt_local,
+		       rqstp->rq_xprt->xpt_locallen);
+		__assign_sockaddr(client, &rqstp->rq_xprt->xpt_remote,
+				  rqstp->rq_xprt->xpt_remotelen);
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->inode = d_inode(fhp->fh_dentry);
+		__entry->type = type;
+		__entry->access = access;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x type=%s access=%s",
+		__entry->xid, __entry->fh_hash,
+		show_fs_file_type(__entry->type),
+		show_nfsd_may_flags(__entry->access)
+	)
+);
+
+TRACE_EVENT_CONDITION(nfsd_fh_verify_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		umode_t type,
+		int access,
+		__be32 error
+	),
+	TP_ARGS(rqstp, fhp, type, access, error),
+	TP_CONDITION(rqstp != NULL && error),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__sockaddr(server, rqstp->rq_xprt->xpt_locallen)
+		__sockaddr(client, rqstp->rq_xprt->xpt_remotelen)
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(const void *, inode)
+		__field(unsigned long, type)
+		__field(unsigned long, access)
+		__field(int, error)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = SVC_NET(rqstp)->ns.inum;
+		__assign_sockaddr(server, &rqstp->rq_xprt->xpt_local,
+		       rqstp->rq_xprt->xpt_locallen);
+		__assign_sockaddr(client, &rqstp->rq_xprt->xpt_remote,
+				  rqstp->rq_xprt->xpt_remotelen);
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		if (fhp->fh_dentry)
+			__entry->inode = d_inode(fhp->fh_dentry);
+		else
+			__entry->inode = NULL;
+		__entry->type = type;
+		__entry->access = access;
+		__entry->error = be32_to_cpu(error);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x type=%s access=%s error=%d",
+		__entry->xid, __entry->fh_hash,
+		show_fs_file_type(__entry->type),
+		show_nfsd_may_flags(__entry->access),
+		__entry->error
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_fh_err_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 int		status),
+	TP_ARGS(rqstp, fhp, status),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->status = status;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x status=%d",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->status)
+)
+
+#define DEFINE_NFSD_FH_ERR_EVENT(name)			\
+DEFINE_EVENT_CONDITION(nfsd_fh_err_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,		\
+		 struct svc_fh	*fhp,			\
+		 int		status),		\
+	TP_ARGS(rqstp, fhp, status),			\
+	TP_CONDITION(rqstp != NULL))
+
+DEFINE_NFSD_FH_ERR_EVENT(set_fh_dentry_badexport);
+DEFINE_NFSD_FH_ERR_EVENT(set_fh_dentry_badhandle);
+DEFINE_NFSD_FH_ERR_EVENT(set_fh_dentry_badmac);
+
+TRACE_EVENT(nfsd_exp_find_key,
+	TP_PROTO(const struct svc_expkey *key,
+		 int status),
+	TP_ARGS(key, status),
+	TP_STRUCT__entry(
+		__field(u8, fsidtype)
+		__array(u32, fsid, 6)
+		__string(auth_domain, key->ek_client->name)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->fsidtype = key->ek_fsidtype;
+		memcpy(__entry->fsid, key->ek_fsid, 4*6);
+		__assign_str(auth_domain);
+		__entry->status = status;
+	),
+	TP_printk("fsid=%x::%s domain=%s status=%d",
+		__entry->fsidtype,
+		__print_array(__entry->fsid, 6, 4),
+		__get_str(auth_domain),
+		__entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_expkey_update,
+	TP_PROTO(const struct svc_expkey *key, const char *exp_path),
+	TP_ARGS(key, exp_path),
+	TP_STRUCT__entry(
+		__field(u8, fsidtype)
+		__array(u32, fsid, 6)
+		__string(auth_domain, key->ek_client->name)
+		__string(path, exp_path)
+		__field(bool, cache)
+	),
+	TP_fast_assign(
+		__entry->fsidtype = key->ek_fsidtype;
+		memcpy(__entry->fsid, key->ek_fsid, 4*6);
+		__assign_str(auth_domain);
+		__assign_str(path);
+		__entry->cache = !test_bit(CACHE_NEGATIVE, &key->h.flags);
+	),
+	TP_printk("fsid=%x::%s domain=%s path=%s cache=%s",
+		__entry->fsidtype,
+		__print_array(__entry->fsid, 6, 4),
+		__get_str(auth_domain),
+		__get_str(path),
+		__entry->cache ? "pos" : "neg"
+	)
+);
+
+TRACE_EVENT(nfsd_exp_get_by_name,
+	TP_PROTO(const struct svc_export *key,
+		 int status),
+	TP_ARGS(key, status),
+	TP_STRUCT__entry(
+		__string(path, key->ex_path.dentry->d_name.name)
+		__string(auth_domain, key->ex_client->name)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__assign_str(path);
+		__assign_str(auth_domain);
+		__entry->status = status;
+	),
+	TP_printk("path=%s domain=%s status=%d",
+		__get_str(path),
+		__get_str(auth_domain),
+		__entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_export_update,
+	TP_PROTO(const struct svc_export *key),
+	TP_ARGS(key),
+	TP_STRUCT__entry(
+		__string(path, key->ex_path.dentry->d_name.name)
+		__string(auth_domain, key->ex_client->name)
+		__field(bool, cache)
+	),
+	TP_fast_assign(
+		__assign_str(path);
+		__assign_str(auth_domain);
+		__entry->cache = !test_bit(CACHE_NEGATIVE, &key->h.flags);
+	),
+	TP_printk("path=%s domain=%s cache=%s",
+		__get_str(path),
+		__get_str(auth_domain),
+		__entry->cache ? "pos" : "neg"
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_io_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 u64		offset,
+		 u32		len),
+	TP_ARGS(rqstp, fhp, offset, len),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(u64, offset)
+		__field(u32, len)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->offset = offset;
+		__entry->len = len;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x offset=%llu len=%u",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->offset, __entry->len)
+)
+
+#define DEFINE_NFSD_IO_EVENT(name)		\
+DEFINE_EVENT(nfsd_io_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,	\
+		 struct svc_fh	*fhp,		\
+		 u64		offset,		\
+		 u32		len),		\
+	TP_ARGS(rqstp, fhp, offset, len))
+
+DEFINE_NFSD_IO_EVENT(read_start);
+DEFINE_NFSD_IO_EVENT(read_splice);
+DEFINE_NFSD_IO_EVENT(read_vector);
+DEFINE_NFSD_IO_EVENT(read_direct);
+DEFINE_NFSD_IO_EVENT(read_io_done);
+DEFINE_NFSD_IO_EVENT(read_done);
+DEFINE_NFSD_IO_EVENT(write_start);
+DEFINE_NFSD_IO_EVENT(write_opened);
+DEFINE_NFSD_IO_EVENT(write_direct);
+DEFINE_NFSD_IO_EVENT(write_vector);
+DEFINE_NFSD_IO_EVENT(write_io_done);
+DEFINE_NFSD_IO_EVENT(write_done);
+DEFINE_NFSD_IO_EVENT(commit_start);
+DEFINE_NFSD_IO_EVENT(commit_done);
+
+DECLARE_EVENT_CLASS(nfsd_err_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 loff_t		offset,
+		 int		status),
+	TP_ARGS(rqstp, fhp, offset, status),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(loff_t, offset)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->offset = offset;
+		__entry->status = status;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x offset=%lld status=%d",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->offset, __entry->status)
+)
+
+#define DEFINE_NFSD_ERR_EVENT(name)		\
+DEFINE_EVENT(nfsd_err_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,	\
+		 struct svc_fh	*fhp,		\
+		 loff_t		offset,		\
+		 int		len),		\
+	TP_ARGS(rqstp, fhp, offset, len))
+
+DEFINE_NFSD_ERR_EVENT(read_err);
+DEFINE_NFSD_ERR_EVENT(write_err);
+
+TRACE_EVENT(nfsd_dirent,
+	TP_PROTO(struct svc_fh *fhp,
+		 u64 ino,
+		 const char *name,
+		 int namlen),
+	TP_ARGS(fhp, ino, name, namlen),
+	TP_STRUCT__entry(
+		__field(u32, fh_hash)
+		__field(u64, ino)
+		__string_len(name, name, namlen)
+	),
+	TP_fast_assign(
+		__entry->fh_hash = fhp ? knfsd_fh_hash(&fhp->fh_handle) : 0;
+		__entry->ino = ino;
+		__assign_str(name);
+	),
+	TP_printk("fh_hash=0x%08x ino=%llu name=%s",
+		__entry->fh_hash, __entry->ino, __get_str(name)
+	)
+)
+
+DECLARE_EVENT_CLASS(nfsd_copy_err_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*src_fhp,
+		 loff_t		src_offset,
+		 struct svc_fh	*dst_fhp,
+		 loff_t		dst_offset,
+		 u64		count,
+		 int		status),
+	TP_ARGS(rqstp, src_fhp, src_offset, dst_fhp, dst_offset, count, status),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, src_fh_hash)
+		__field(loff_t, src_offset)
+		__field(u32, dst_fh_hash)
+		__field(loff_t, dst_offset)
+		__field(u64, count)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->src_fh_hash = knfsd_fh_hash(&src_fhp->fh_handle);
+		__entry->src_offset = src_offset;
+		__entry->dst_fh_hash = knfsd_fh_hash(&dst_fhp->fh_handle);
+		__entry->dst_offset = dst_offset;
+		__entry->count = count;
+		__entry->status = status;
+	),
+	TP_printk("xid=0x%08x src_fh_hash=0x%08x src_offset=%lld "
+			"dst_fh_hash=0x%08x dst_offset=%lld "
+			"count=%llu status=%d",
+		  __entry->xid, __entry->src_fh_hash, __entry->src_offset,
+		  __entry->dst_fh_hash, __entry->dst_offset,
+		  (unsigned long long)__entry->count,
+		  __entry->status)
+)
+
+#define DEFINE_NFSD_COPY_ERR_EVENT(name)		\
+DEFINE_EVENT(nfsd_copy_err_class, nfsd_##name,		\
+	TP_PROTO(struct svc_rqst	*rqstp,		\
+		 struct svc_fh		*src_fhp,	\
+		 loff_t			src_offset,	\
+		 struct svc_fh		*dst_fhp,	\
+		 loff_t			dst_offset,	\
+		 u64			count,		\
+		 int			status),	\
+	TP_ARGS(rqstp, src_fhp, src_offset, dst_fhp, dst_offset, \
+		count, status))
+
+DEFINE_NFSD_COPY_ERR_EVENT(clone_file_range_err);
+
+#include "state.h"
+#include "filecache.h"
+#include "vfs.h"
+
+TRACE_EVENT(nfsd_delegret_wakeup,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		long timeo
+	),
+	TP_ARGS(rqstp, inode, timeo),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(long, timeo)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->inode = inode;
+		__entry->timeo = timeo;
+	),
+	TP_printk("xid=0x%08x inode=%p%s",
+		  __entry->xid, __entry->inode,
+		  __entry->timeo == 0 ? " (timed out)" : ""
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_stateid_class,
+	TP_PROTO(stateid_t *stp),
+	TP_ARGS(stp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+	),
+	TP_printk("client %08x:%08x stateid %08x:%08x",
+		__entry->cl_boot,
+		__entry->cl_id,
+		__entry->si_id,
+		__entry->si_generation)
+)
+
+#define DEFINE_STATEID_EVENT(name) \
+DEFINE_EVENT(nfsd_stateid_class, nfsd_##name, \
+	TP_PROTO(stateid_t *stp), \
+	TP_ARGS(stp))
+
+DEFINE_STATEID_EVENT(layoutstate_alloc);
+DEFINE_STATEID_EVENT(layoutstate_unhash);
+DEFINE_STATEID_EVENT(layoutstate_free);
+DEFINE_STATEID_EVENT(layout_get_lookup_fail);
+DEFINE_STATEID_EVENT(layout_commit_lookup_fail);
+DEFINE_STATEID_EVENT(layout_return_lookup_fail);
+DEFINE_STATEID_EVENT(layout_recall);
+DEFINE_STATEID_EVENT(layout_recall_done);
+DEFINE_STATEID_EVENT(layout_recall_fail);
+DEFINE_STATEID_EVENT(layout_recall_release);
+
+DEFINE_STATEID_EVENT(open);
+DEFINE_STATEID_EVENT(deleg_read);
+DEFINE_STATEID_EVENT(deleg_write);
+DEFINE_STATEID_EVENT(deleg_return);
+
+DECLARE_EVENT_CLASS(nfsd_stateseqid_class,
+	TP_PROTO(u32 seqid, const stateid_t *stp),
+	TP_ARGS(seqid, stp),
+	TP_STRUCT__entry(
+		__field(u32, seqid)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+	),
+	TP_fast_assign(
+		__entry->seqid = seqid;
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+	),
+	TP_printk("seqid=%u client %08x:%08x stateid %08x:%08x",
+		__entry->seqid, __entry->cl_boot, __entry->cl_id,
+		__entry->si_id, __entry->si_generation)
+)
+
+#define DEFINE_STATESEQID_EVENT(name) \
+DEFINE_EVENT(nfsd_stateseqid_class, nfsd_##name, \
+	TP_PROTO(u32 seqid, const stateid_t *stp), \
+	TP_ARGS(seqid, stp))
+
+DEFINE_STATESEQID_EVENT(preprocess);
+DEFINE_STATESEQID_EVENT(open_confirm);
+
+#define show_stid_type(x)						\
+	__print_flags(x, "|",						\
+		{ SC_TYPE_OPEN,		"OPEN" },		\
+		{ SC_TYPE_LOCK,		"LOCK" },		\
+		{ SC_TYPE_DELEG,		"DELEG" },		\
+		{ SC_TYPE_LAYOUT,		"LAYOUT" })
+
+#define show_stid_status(x)						\
+	__print_flags(x, "|",						\
+		{ SC_STATUS_CLOSED,		"CLOSED" },		\
+		{ SC_STATUS_REVOKED,		"REVOKED" },		\
+		{ SC_STATUS_ADMIN_REVOKED,	"ADMIN_REVOKED" })
+
+DECLARE_EVENT_CLASS(nfsd_stid_class,
+	TP_PROTO(
+		const struct nfs4_stid *stid
+	),
+	TP_ARGS(stid),
+	TP_STRUCT__entry(
+		__field(unsigned long, sc_type)
+		__field(unsigned long, sc_status)
+		__field(int, sc_count)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+	),
+	TP_fast_assign(
+		const stateid_t *stp = &stid->sc_stateid;
+
+		__entry->sc_type = stid->sc_type;
+		__entry->sc_status = stid->sc_status;
+		__entry->sc_count = refcount_read(&stid->sc_count);
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+	),
+	TP_printk("client %08x:%08x stateid %08x:%08x ref=%d type=%s state=%s",
+		__entry->cl_boot, __entry->cl_id,
+		__entry->si_id, __entry->si_generation,
+		__entry->sc_count, show_stid_type(__entry->sc_type),
+		show_stid_status(__entry->sc_status)
+	)
+);
+
+#define DEFINE_STID_EVENT(name)					\
+DEFINE_EVENT(nfsd_stid_class, nfsd_stid_##name,			\
+	TP_PROTO(const struct nfs4_stid *stid),			\
+	TP_ARGS(stid))
+
+DEFINE_STID_EVENT(revoke);
+
+TRACE_EVENT(nfsd_stateowner_replay,
+	TP_PROTO(
+		u32 opnum,
+		const struct nfs4_replay *rp
+	),
+	TP_ARGS(opnum, rp),
+	TP_STRUCT__entry(
+		__field(unsigned long, status)
+		__field(u32, opnum)
+	),
+	TP_fast_assign(
+		__entry->status = be32_to_cpu(rp->rp_status);
+		__entry->opnum = opnum;
+	),
+	TP_printk("opnum=%u status=%lu",
+		__entry->opnum, __entry->status)
+);
+
+TRACE_EVENT_CONDITION(nfsd_seq4_status,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct nfsd4_sequence *sequence
+	),
+	TP_ARGS(rqstp, sequence),
+	TP_CONDITION(sequence->status_flags),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(u32, xid)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, seqno)
+		__field(u32, reserved)
+		__field(unsigned long, status_flags)
+	),
+	TP_fast_assign(
+		const struct nfsd4_sessionid *sid =
+			(struct nfsd4_sessionid *)&sequence->sessionid;
+
+		__entry->netns_ino = SVC_NET(rqstp)->ns.inum;
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->cl_boot = sid->clientid.cl_boot;
+		__entry->cl_id = sid->clientid.cl_id;
+		__entry->seqno = sid->sequence;
+		__entry->reserved = sid->reserved;
+		__entry->status_flags = sequence->status_flags;
+	),
+	TP_printk("xid=0x%08x sessionid=%08x:%08x:%08x:%08x status_flags=%s",
+		__entry->xid, __entry->cl_boot, __entry->cl_id,
+		__entry->seqno, __entry->reserved,
+		show_nfs4_seq4_status(__entry->status_flags)
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_cs_slot_class,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct nfsd4_create_session *cs
+	),
+	TP_ARGS(clp, cs),
+	TP_STRUCT__entry(
+		__field(u32, seqid)
+		__field(u32, slot_seqid)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		const struct nfsd4_clid_slot *slot = &clp->cl_cs_slot;
+
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen);
+		__entry->seqid = cs->seqid;
+		__entry->slot_seqid = slot->sl_seqid;
+	),
+	TP_printk("addr=%pISpc client %08x:%08x seqid=%u slot_seqid=%u",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->seqid, __entry->slot_seqid
+	)
+);
+
+#define DEFINE_CS_SLOT_EVENT(name) \
+DEFINE_EVENT(nfsd_cs_slot_class, nfsd_##name, \
+	TP_PROTO( \
+		const struct nfs4_client *clp, \
+		const struct nfsd4_create_session *cs \
+	), \
+	TP_ARGS(clp, cs))
+
+DEFINE_CS_SLOT_EVENT(slot_seqid_conf);
+DEFINE_CS_SLOT_EVENT(slot_seqid_unconf);
+
+#define show_nfs_slot_flags(val)					\
+	__print_flags(val, "|",						\
+		{ NFSD4_SLOT_INUSE,		"INUSE" },		\
+		{ NFSD4_SLOT_CACHETHIS,		"CACHETHIS" },		\
+		{ NFSD4_SLOT_INITIALIZED,	"INITIALIZED" },	\
+		{ NFSD4_SLOT_CACHED,		"CACHED" },		\
+		{ NFSD4_SLOT_REUSED,		"REUSED" })
+
+TRACE_EVENT(nfsd_slot_seqid_sequence,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct nfsd4_sequence *seq,
+		const struct nfsd4_slot *slot
+	),
+	TP_ARGS(clp, seq, slot),
+	TP_STRUCT__entry(
+		__field(u32, seqid)
+		__field(u32, slot_seqid)
+		__field(u32, slot_index)
+		__field(unsigned long, slot_flags)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen);
+		__entry->seqid = seq->seqid;
+		__entry->slot_seqid = slot->sl_seqid;
+		__entry->slot_index = seq->slotid;
+		__entry->slot_flags = slot->sl_flags;
+	),
+	TP_printk("addr=%pISpc client %08x:%08x idx=%u seqid=%u slot_seqid=%u flags=%s",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->slot_index, __entry->seqid, __entry->slot_seqid,
+		show_nfs_slot_flags(__entry->slot_flags)
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_clientid_class,
+	TP_PROTO(const clientid_t *clid),
+	TP_ARGS(clid),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clid->cl_boot;
+		__entry->cl_id = clid->cl_id;
+	),
+	TP_printk("client %08x:%08x", __entry->cl_boot, __entry->cl_id)
+)
+
+#define DEFINE_CLIENTID_EVENT(name) \
+DEFINE_EVENT(nfsd_clientid_class, nfsd_clid_##name, \
+	TP_PROTO(const clientid_t *clid), \
+	TP_ARGS(clid))
+
+DEFINE_CLIENTID_EVENT(expire_unconf);
+DEFINE_CLIENTID_EVENT(reclaim_complete);
+DEFINE_CLIENTID_EVENT(confirmed);
+DEFINE_CLIENTID_EVENT(destroyed);
+DEFINE_CLIENTID_EVENT(admin_expired);
+DEFINE_CLIENTID_EVENT(replaced);
+DEFINE_CLIENTID_EVENT(purged);
+DEFINE_CLIENTID_EVENT(renew);
+DEFINE_CLIENTID_EVENT(stale);
+
+TRACE_EVENT(nfsd_mark_client_expired,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		int cl_rpc_users
+	),
+	TP_ARGS(clp, cl_rpc_users),
+	TP_STRUCT__entry(
+		__field(int, cl_rpc_users)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_rpc_users = cl_rpc_users;
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x cl_rpc_users=%d",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->cl_rpc_users)
+);
+
+DECLARE_EVENT_CLASS(nfsd_net_class,
+	TP_PROTO(const struct nfsd_net *nn),
+	TP_ARGS(nn),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+	),
+	TP_printk("boot_time=%16llx", __entry->boot_time)
+)
+
+#define DEFINE_NET_EVENT(name) \
+DEFINE_EVENT(nfsd_net_class, nfsd_##name, \
+	TP_PROTO(const struct nfsd_net *nn), \
+	TP_ARGS(nn))
+
+DEFINE_NET_EVENT(grace_start);
+DEFINE_NET_EVENT(grace_complete);
+
+TRACE_EVENT(nfsd_writeverf_reset,
+	TP_PROTO(
+		const struct nfsd_net *nn,
+		const struct svc_rqst *rqstp,
+		int error
+	),
+	TP_ARGS(nn, rqstp, error),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+		__field(u32, xid)
+		__field(int, error)
+		__array(unsigned char, verifier, NFS4_VERIFIER_SIZE)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->error = error;
+
+		/* avoid seqlock inside TP_fast_assign */
+		memcpy(__entry->verifier, nn->writeverf,
+		       NFS4_VERIFIER_SIZE);
+	),
+	TP_printk("boot_time=%16llx xid=0x%08x error=%d new verifier=0x%s",
+		__entry->boot_time, __entry->xid, __entry->error,
+		__print_hex_str(__entry->verifier, NFS4_VERIFIER_SIZE)
+	)
+);
+
+TRACE_EVENT(nfsd_clid_cred_mismatch,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct svc_rqst *rqstp
+	),
+	TP_ARGS(clp, rqstp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(unsigned long, cl_flavor)
+		__field(unsigned long, new_flavor)
+		__sockaddr(addr, rqstp->rq_xprt->xpt_remotelen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->cl_flavor = clp->cl_cred.cr_flavor;
+		__entry->new_flavor = rqstp->rq_cred.cr_flavor;
+		__assign_sockaddr(addr, &rqstp->rq_xprt->xpt_remote,
+				  rqstp->rq_xprt->xpt_remotelen);
+	),
+	TP_printk("client %08x:%08x flavor=%s, conflict=%s from addr=%pISpc",
+		__entry->cl_boot, __entry->cl_id,
+		show_nfsd_authflavor(__entry->cl_flavor),
+		show_nfsd_authflavor(__entry->new_flavor),
+		__get_sockaddr(addr)
+	)
+)
+
+TRACE_EVENT(nfsd_clid_verf_mismatch,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct svc_rqst *rqstp,
+		const nfs4_verifier *verf
+	),
+	TP_ARGS(clp, rqstp, verf),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__array(unsigned char, cl_verifier, NFS4_VERIFIER_SIZE)
+		__array(unsigned char, new_verifier, NFS4_VERIFIER_SIZE)
+		__sockaddr(addr, rqstp->rq_xprt->xpt_remotelen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		memcpy(__entry->cl_verifier, (void *)&clp->cl_verifier,
+		       NFS4_VERIFIER_SIZE);
+		memcpy(__entry->new_verifier, (void *)verf,
+		       NFS4_VERIFIER_SIZE);
+		__assign_sockaddr(addr, &rqstp->rq_xprt->xpt_remote,
+				  rqstp->rq_xprt->xpt_remotelen);
+	),
+	TP_printk("client %08x:%08x verf=0x%s, updated=0x%s from addr=%pISpc",
+		__entry->cl_boot, __entry->cl_id,
+		__print_hex_str(__entry->cl_verifier, NFS4_VERIFIER_SIZE),
+		__print_hex_str(__entry->new_verifier, NFS4_VERIFIER_SIZE),
+		__get_sockaddr(addr)
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_clid_class,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+		__field(unsigned long, flavor)
+		__array(unsigned char, verifier, NFS4_VERIFIER_SIZE)
+		__string_len(name, clp->cl_name.data, clp->cl_name.len)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		memcpy(__entry->addr, &clp->cl_addr,
+			sizeof(struct sockaddr_in6));
+		__entry->flavor = clp->cl_cred.cr_flavor;
+		memcpy(__entry->verifier, (void *)&clp->cl_verifier,
+		       NFS4_VERIFIER_SIZE);
+		__assign_str(name);
+	),
+	TP_printk("addr=%pISpc name='%s' verifier=0x%s flavor=%s client=%08x:%08x",
+		__entry->addr, __get_str(name),
+		__print_hex_str(__entry->verifier, NFS4_VERIFIER_SIZE),
+		show_nfsd_authflavor(__entry->flavor),
+		__entry->cl_boot, __entry->cl_id)
+);
+
+#define DEFINE_CLID_EVENT(name) \
+DEFINE_EVENT(nfsd_clid_class, nfsd_clid_##name, \
+	TP_PROTO(const struct nfs4_client *clp), \
+	TP_ARGS(clp))
+
+DEFINE_CLID_EVENT(fresh);
+DEFINE_CLID_EVENT(confirmed_r);
+
+/*
+ * from fs/nfsd/filecache.h
+ */
+#define show_nf_flags(val)						\
+	__print_flags(val, "|",						\
+		{ 1 << NFSD_FILE_HASHED,	"HASHED" },		\
+		{ 1 << NFSD_FILE_PENDING,	"PENDING" },		\
+		{ 1 << NFSD_FILE_REFERENCED,	"REFERENCED" },		\
+		{ 1 << NFSD_FILE_RECENT,	"RECENT" },		\
+		{ 1 << NFSD_FILE_GC,		"GC" })
+
+DECLARE_EVENT_CLASS(nfsd_file_class,
+	TP_PROTO(struct nfsd_file *nf),
+	TP_ARGS(nf),
+	TP_STRUCT__entry(
+		__field(void *, nf_inode)
+		__field(int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned char, nf_may)
+		__field(struct file *, nf_file)
+	),
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_file = nf->nf_file;
+	),
+	TP_printk("inode=%p ref=%d flags=%s may=%s nf_file=%p",
+		__entry->nf_inode,
+		__entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may),
+		__entry->nf_file)
+)
+
+#define DEFINE_NFSD_FILE_EVENT(name) \
+DEFINE_EVENT(nfsd_file_class, name, \
+	TP_PROTO(struct nfsd_file *nf), \
+	TP_ARGS(nf))
+
+DEFINE_NFSD_FILE_EVENT(nfsd_file_free);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_put);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_closing);
+
+TRACE_EVENT(nfsd_file_alloc,
+	TP_PROTO(
+		const struct nfsd_file *nf
+	),
+	TP_ARGS(nf),
+	TP_STRUCT__entry(
+		__field(const void *, nf_inode)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(unsigned int, nf_ref)
+	),
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_may = nf->nf_may;
+	),
+	TP_printk("inode=%p ref=%u flags=%s may=%s",
+		__entry->nf_inode, __entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may)
+	)
+);
+
+TRACE_EVENT(nfsd_file_get_dio_attrs,
+	TP_PROTO(
+		const struct inode *inode,
+		const struct kstat *stat
+	),
+	TP_ARGS(inode, stat),
+	TP_STRUCT__entry(
+		__field(const void *, inode)
+		__field(unsigned long, mask)
+		__field(u32, mem_align)
+		__field(u32, offset_align)
+		__field(u32, read_offset_align)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+		__entry->mask = stat->result_mask;
+		__entry->mem_align = stat->dio_mem_align;
+		__entry->offset_align = stat->dio_offset_align;
+		__entry->read_offset_align = stat->dio_read_offset_align;
+	),
+	TP_printk("inode=%p flags=%s mem_align=%u offset_align=%u read_offset_align=%u",
+		__entry->inode, show_statx_mask(__entry->mask),
+		__entry->mem_align, __entry->offset_align,
+		__entry->read_offset_align
+	)
+);
+
+TRACE_EVENT(nfsd_file_acquire,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		unsigned int may_flags,
+		const struct nfsd_file *nf,
+		__be32 status
+	),
+
+	TP_ARGS(rqstp, inode, may_flags, nf, status),
+
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(unsigned long, may_flags)
+		__field(unsigned int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(const void *, nf_file)
+		__field(u32, status)
+	),
+
+	TP_fast_assign(
+		__entry->xid = rqstp ? be32_to_cpu(rqstp->rq_xid) : 0;
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->nf_ref = nf ? refcount_read(&nf->nf_ref) : 0;
+		__entry->nf_flags = nf ? nf->nf_flags : 0;
+		__entry->nf_may = nf ? nf->nf_may : 0;
+		__entry->nf_file = nf ? nf->nf_file : NULL;
+		__entry->status = be32_to_cpu(status);
+	),
+
+	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%u nf_flags=%s nf_may=%s nf_file=%p status=%u",
+			__entry->xid, __entry->inode,
+			show_nfsd_may_flags(__entry->may_flags),
+			__entry->nf_ref, show_nf_flags(__entry->nf_flags),
+			show_nfsd_may_flags(__entry->nf_may),
+			__entry->nf_file, __entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_file_insert_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		unsigned int may_flags,
+		long error
+	),
+	TP_ARGS(rqstp, inode, may_flags, error),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(unsigned long, may_flags)
+		__field(long, error)
+	),
+	TP_fast_assign(
+		__entry->xid = rqstp ? be32_to_cpu(rqstp->rq_xid) : 0;
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->error = error;
+	),
+	TP_printk("xid=0x%x inode=%p may_flags=%s error=%ld",
+		__entry->xid, __entry->inode,
+		show_nfsd_may_flags(__entry->may_flags),
+		__entry->error
+	)
+);
+
+TRACE_EVENT(nfsd_file_cons_err,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
+		unsigned int may_flags,
+		const struct nfsd_file *nf
+	),
+	TP_ARGS(rqstp, inode, may_flags, nf),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(const void *, inode)
+		__field(unsigned long, may_flags)
+		__field(unsigned int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(const void *, nf_file)
+	),
+	TP_fast_assign(
+		__entry->xid = rqstp ? be32_to_cpu(rqstp->rq_xid) : 0;
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_file = nf->nf_file;
+	),
+	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%u nf_flags=%s nf_may=%s nf_file=%p",
+		__entry->xid, __entry->inode,
+		show_nfsd_may_flags(__entry->may_flags), __entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may), __entry->nf_file
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_file_open_class,
+	TP_PROTO(const struct nfsd_file *nf, __be32 status),
+	TP_ARGS(nf, status),
+	TP_STRUCT__entry(
+		__field(void *, nf_inode)	/* cannot be dereferenced */
+		__field(int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(void *, nf_file)	/* cannot be dereferenced */
+	),
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_file = nf->nf_file;
+	),
+	TP_printk("inode=%p ref=%d flags=%s may=%s file=%p",
+		__entry->nf_inode,
+		__entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may),
+		__entry->nf_file)
+)
+
+#define DEFINE_NFSD_FILE_OPEN_EVENT(name)					\
+DEFINE_EVENT(nfsd_file_open_class, name,					\
+	TP_PROTO(							\
+		const struct nfsd_file *nf,				\
+		__be32 status						\
+	),								\
+	TP_ARGS(nf, status))
+
+DEFINE_NFSD_FILE_OPEN_EVENT(nfsd_file_open);
+DEFINE_NFSD_FILE_OPEN_EVENT(nfsd_file_opened);
+
+TRACE_EVENT(nfsd_file_is_cached,
+	TP_PROTO(
+		const struct inode *inode,
+		int found
+	),
+	TP_ARGS(inode, found),
+	TP_STRUCT__entry(
+		__field(const struct inode *, inode)
+		__field(int, found)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+		__entry->found = found;
+	),
+	TP_printk("inode=%p is %scached",
+		__entry->inode,
+		__entry->found ? "" : "not "
+	)
+);
+
+TRACE_EVENT(nfsd_file_fsnotify_handle_event,
+	TP_PROTO(struct inode *inode, u32 mask),
+	TP_ARGS(inode, mask),
+	TP_STRUCT__entry(
+		__field(struct inode *, inode)
+		__field(unsigned int, nlink)
+		__field(umode_t, mode)
+		__field(u32, mask)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+		__entry->nlink = inode->i_nlink;
+		__entry->mode = inode->i_mode;
+		__entry->mask = mask;
+	),
+	TP_printk("inode=%p nlink=%u mode=0%ho mask=0x%x", __entry->inode,
+			__entry->nlink, __entry->mode, __entry->mask)
+);
+
+TRACE_EVENT(nfsd_handle_dir_event,
+	TP_PROTO(u32 mask, const struct inode *dir, const struct qstr *name),
+	TP_ARGS(mask, dir, name),
+	TP_STRUCT__entry(
+		__field(u32, mask)
+		__field(dev_t, s_dev)
+		__field(u64, i_ino)
+		__string_len(name, name ? name->name : NULL,
+				   name ? name->len : 0)
+	),
+	TP_fast_assign(
+		__entry->mask = mask;
+		__entry->s_dev = dir ? dir->i_sb->s_dev : 0;
+		__entry->i_ino = dir ? dir->i_ino : 0;
+		__assign_str(name);
+	),
+	TP_printk("inode=0x%x:0x%x:0x%llx mask=%s name=%s",
+			MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+			__entry->i_ino, show_fsnotify_mask(__entry->mask),
+			__get_str(name))
+);
+
+DECLARE_EVENT_CLASS(nfsd_file_gc_class,
+	TP_PROTO(
+		const struct nfsd_file *nf
+	),
+	TP_ARGS(nf),
+	TP_STRUCT__entry(
+		__field(void *, nf_inode)
+		__field(void *, nf_file)
+		__field(int, nf_ref)
+		__field(unsigned long, nf_flags)
+	),
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_file = nf->nf_file;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+	),
+	TP_printk("inode=%p ref=%d nf_flags=%s nf_file=%p",
+		__entry->nf_inode, __entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		__entry->nf_file
+	)
+);
+
+#define DEFINE_NFSD_FILE_GC_EVENT(name)					\
+DEFINE_EVENT(nfsd_file_gc_class, name,					\
+	TP_PROTO(							\
+		const struct nfsd_file *nf				\
+	),								\
+	TP_ARGS(nf))
+
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_lru_add);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_lru_del);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_in_use);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_writeback);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_referenced);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_aged);
+DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_disposed);
+
+DECLARE_EVENT_CLASS(nfsd_file_lruwalk_class,
+	TP_PROTO(
+		unsigned long removed,
+		unsigned long remaining
+	),
+	TP_ARGS(removed, remaining),
+	TP_STRUCT__entry(
+		__field(unsigned long, removed)
+		__field(unsigned long, remaining)
+	),
+	TP_fast_assign(
+		__entry->removed = removed;
+		__entry->remaining = remaining;
+	),
+	TP_printk("%lu entries removed, %lu remaining",
+		__entry->removed, __entry->remaining)
+);
+
+#define DEFINE_NFSD_FILE_LRUWALK_EVENT(name)				\
+DEFINE_EVENT(nfsd_file_lruwalk_class, name,				\
+	TP_PROTO(							\
+		unsigned long removed,					\
+		unsigned long remaining					\
+	),								\
+	TP_ARGS(removed, remaining))
+
+DEFINE_NFSD_FILE_LRUWALK_EVENT(nfsd_file_gc_removed);
+DEFINE_NFSD_FILE_LRUWALK_EVENT(nfsd_file_shrinker_removed);
+
+TRACE_EVENT(nfsd_file_close,
+	TP_PROTO(
+		const struct inode *inode
+	),
+	TP_ARGS(inode),
+	TP_STRUCT__entry(
+		__field(const void *, inode)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+	),
+	TP_printk("inode=%p",
+		__entry->inode
+	)
+);
+
+#include "cache.h"
+
+TRACE_DEFINE_ENUM(RC_DROPIT);
+TRACE_DEFINE_ENUM(RC_REPLY);
+TRACE_DEFINE_ENUM(RC_DOIT);
+
+#define show_drc_retval(x)						\
+	__print_symbolic(x,						\
+		{ RC_DROPIT, "DROPIT" },				\
+		{ RC_REPLY, "REPLY" },					\
+		{ RC_DOIT, "DOIT" })
+
+TRACE_EVENT(nfsd_drc_found,
+	TP_PROTO(
+		const struct nfsd_net *nn,
+		const struct svc_rqst *rqstp,
+		int result
+	),
+	TP_ARGS(nn, rqstp, result),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+		__field(unsigned long, result)
+		__field(u32, xid)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+		__entry->result = result;
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+	),
+	TP_printk("boot_time=%16llx xid=0x%08x result=%s",
+		__entry->boot_time, __entry->xid,
+		show_drc_retval(__entry->result))
+
+);
+
+TRACE_EVENT(nfsd_drc_mismatch,
+	TP_PROTO(
+		const struct nfsd_net *nn,
+		const struct nfsd_cacherep *key,
+		const struct nfsd_cacherep *rp
+	),
+	TP_ARGS(nn, key, rp),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+		__field(u32, xid)
+		__field(u32, cached)
+		__field(u32, ingress)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+		__entry->xid = be32_to_cpu(key->c_key.k_xid);
+		__entry->cached = (__force u32)key->c_key.k_csum;
+		__entry->ingress = (__force u32)rp->c_key.k_csum;
+	),
+	TP_printk("boot_time=%16llx xid=0x%08x cached-csum=0x%08x ingress-csum=0x%08x",
+		__entry->boot_time, __entry->xid, __entry->cached,
+		__entry->ingress)
+);
+
+TRACE_EVENT(nfsd_cb_args,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct nfs4_cb_conn *conn
+	),
+	TP_ARGS(clp, conn),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, prog)
+		__field(u32, ident)
+		__sockaddr(addr, conn->cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->prog = conn->cb_prog;
+		__entry->ident = conn->cb_ident;
+		__assign_sockaddr(addr, &conn->cb_addr, conn->cb_addrlen);
+	),
+	TP_printk("addr=%pISpc client %08x:%08x prog=%u ident=%u",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->prog, __entry->ident)
+);
+
+TRACE_EVENT(nfsd_cb_nodelegs,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+	),
+	TP_printk("client %08x:%08x", __entry->cl_boot, __entry->cl_id)
+)
+
+#define show_cb_state(val)						\
+	__print_symbolic(val,						\
+		{ NFSD4_CB_UP,		"UP" },				\
+		{ NFSD4_CB_UNKNOWN,	"UNKNOWN" },			\
+		{ NFSD4_CB_DOWN,	"DOWN" },			\
+		{ NFSD4_CB_FAULT,	"FAULT"})
+
+DECLARE_EVENT_CLASS(nfsd_cb_class,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->state = clp->cl_cb_state;
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x state=%s",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		show_cb_state(__entry->state))
+);
+
+#define DEFINE_NFSD_CB_EVENT(name)			\
+DEFINE_EVENT(nfsd_cb_class, nfsd_cb_##name,		\
+	TP_PROTO(const struct nfs4_client *clp),	\
+	TP_ARGS(clp))
+
+DEFINE_NFSD_CB_EVENT(start);
+DEFINE_NFSD_CB_EVENT(new_state);
+DEFINE_NFSD_CB_EVENT(probe);
+DEFINE_NFSD_CB_EVENT(lost);
+DEFINE_NFSD_CB_EVENT(shutdown);
+DEFINE_NFSD_CB_EVENT(rpc_prepare);
+DEFINE_NFSD_CB_EVENT(rpc_done);
+DEFINE_NFSD_CB_EVENT(rpc_release);
+
+TRACE_DEFINE_ENUM(RPC_AUTH_NULL);
+TRACE_DEFINE_ENUM(RPC_AUTH_UNIX);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5I);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5P);
+
+#define show_nfsd_authflavor(val)					\
+	__print_symbolic(val,						\
+		{ RPC_AUTH_NULL,		"none" },		\
+		{ RPC_AUTH_UNIX,		"sys" },		\
+		{ RPC_AUTH_GSS,			"gss" },		\
+		{ RPC_AUTH_GSS_KRB5,		"krb5" },		\
+		{ RPC_AUTH_GSS_KRB5I,		"krb5i" },		\
+		{ RPC_AUTH_GSS_KRB5P,		"krb5p" })
+
+TRACE_EVENT(nfsd_cb_setup,
+	TP_PROTO(const struct nfs4_client *clp,
+		 const char *netid,
+		 rpc_authflavor_t authflavor
+	),
+	TP_ARGS(clp, netid, authflavor),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(unsigned long, authflavor)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+		__string(netid, netid)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_str(netid);
+		__entry->authflavor = authflavor;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x proto=%s flavor=%s",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__get_str(netid), show_nfsd_authflavor(__entry->authflavor))
+);
+
+TRACE_EVENT(nfsd_cb_setup_err,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		long error
+	),
+	TP_ARGS(clp, error),
+	TP_STRUCT__entry(
+		__field(long, error)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->error = error;
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x error=%ld",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->error)
+);
+
+/* Not a real opcode, but there is no 0 operation. */
+#define _CB_NULL	0
+
+#define show_nfsd_cb_opcode(val)					\
+	__print_symbolic(val,						\
+		{ _CB_NULL,			"CB_NULL" },		\
+		{ OP_CB_GETATTR,		"CB_GETATTR" },		\
+		{ OP_CB_RECALL,			"CB_RECALL" },		\
+		{ OP_CB_LAYOUTRECALL,		"CB_LAYOUTRECALL" },	\
+		{ OP_CB_RECALL_ANY,		"CB_RECALL_ANY" },	\
+		{ OP_CB_NOTIFY,			"CB_NOTIFY" },		\
+		{ OP_CB_NOTIFY_LOCK,		"CB_NOTIFY_LOCK" },	\
+		{ OP_CB_OFFLOAD,		"CB_OFFLOAD" })
+
+DECLARE_EVENT_CLASS(nfsd_cb_lifetime_class,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct nfsd4_callback *cb
+	),
+	TP_ARGS(clp, cb),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(const void *, cb)
+		__field(unsigned long, opcode)
+		__field(bool, need_restart)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->cb = cb;
+		__entry->opcode = cb->cb_ops ? cb->cb_ops->opcode : _CB_NULL;
+		__entry->need_restart = test_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags);
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x cb=%p%s opcode=%s",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id, __entry->cb,
+		__entry->need_restart ?  " (need restart)" : " (first try)",
+		show_nfsd_cb_opcode(__entry->opcode)
+	)
+);
+
+#define DEFINE_NFSD_CB_LIFETIME_EVENT(name)		\
+DEFINE_EVENT(nfsd_cb_lifetime_class, nfsd_cb_##name,	\
+	TP_PROTO(					\
+		const struct nfs4_client *clp,		\
+		const struct nfsd4_callback *cb		\
+	),						\
+	TP_ARGS(clp, cb))
+
+DEFINE_NFSD_CB_LIFETIME_EVENT(queue);
+DEFINE_NFSD_CB_LIFETIME_EVENT(destroy);
+DEFINE_NFSD_CB_LIFETIME_EVENT(restart);
+DEFINE_NFSD_CB_LIFETIME_EVENT(bc_update);
+DEFINE_NFSD_CB_LIFETIME_EVENT(bc_shutdown);
+
+TRACE_EVENT(nfsd_cb_seq_status,
+	TP_PROTO(
+		const struct rpc_task *task,
+		const struct nfsd4_callback *cb,
+		const struct nfsd4_session *session
+	),
+	TP_ARGS(task, cb, session),
+	TP_STRUCT__entry(
+		__field(unsigned int, task_id)
+		__field(unsigned int, client_id)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, seqno)
+		__field(u32, reserved)
+		__field(int, tk_status)
+		__field(int, seq_status)
+	),
+	TP_fast_assign(
+		const struct nfsd4_sessionid *sid =
+			(struct nfsd4_sessionid *)&session->se_sessionid;
+
+		__entry->task_id = task->tk_pid;
+		__entry->client_id = task->tk_client ?
+				     task->tk_client->cl_clid : -1;
+		__entry->cl_boot = sid->clientid.cl_boot;
+		__entry->cl_id = sid->clientid.cl_id;
+		__entry->seqno = sid->sequence;
+		__entry->reserved = sid->reserved;
+		__entry->tk_status = task->tk_status;
+		__entry->seq_status = cb->cb_seq_status;
+	),
+	TP_printk(SUNRPC_TRACE_TASK_SPECIFIER
+		" sessionid=%08x:%08x:%08x:%08x tk_status=%d seq_status=%d",
+		__entry->task_id, __entry->client_id,
+		__entry->cl_boot, __entry->cl_id,
+		__entry->seqno, __entry->reserved,
+		__entry->tk_status, __entry->seq_status
+	)
+);
+
+TRACE_EVENT(nfsd_cb_free_slot,
+	TP_PROTO(
+		const struct rpc_task *task,
+		const struct nfsd4_callback *cb,
+		const struct nfsd4_session *session
+	),
+	TP_ARGS(task, cb, session),
+	TP_STRUCT__entry(
+		__field(unsigned int, task_id)
+		__field(unsigned int, client_id)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, seqno)
+		__field(u32, reserved)
+		__field(u32, slot_seqno)
+	),
+	TP_fast_assign(
+		const struct nfsd4_sessionid *sid =
+			(struct nfsd4_sessionid *)&session->se_sessionid;
+
+		__entry->task_id = task->tk_pid;
+		__entry->client_id = task->tk_client ?
+				     task->tk_client->cl_clid : -1;
+		__entry->cl_boot = sid->clientid.cl_boot;
+		__entry->cl_id = sid->clientid.cl_id;
+		__entry->seqno = sid->sequence;
+		__entry->reserved = sid->reserved;
+		__entry->slot_seqno = session->se_cb_seq_nr[cb->cb_held_slot];
+	),
+	TP_printk(SUNRPC_TRACE_TASK_SPECIFIER
+		" sessionid=%08x:%08x:%08x:%08x new slot seqno=%u",
+		__entry->task_id, __entry->client_id,
+		__entry->cl_boot, __entry->cl_id,
+		__entry->seqno, __entry->reserved,
+		__entry->slot_seqno
+	)
+);
+
+TRACE_EVENT_CONDITION(nfsd_cb_recall,
+	TP_PROTO(
+		const struct nfs4_stid *stid
+	),
+	TP_ARGS(stid),
+	TP_CONDITION(stid->sc_client),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+		__sockaddr(addr, stid->sc_client->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		const stateid_t *stp = &stid->sc_stateid;
+		const struct nfs4_client *clp = stid->sc_client;
+
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x stateid %08x:%08x",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->si_id, __entry->si_generation)
+);
+
+TRACE_EVENT(nfsd_cb_notify_lock,
+	TP_PROTO(
+		const struct nfs4_lockowner *lo,
+		const struct nfsd4_blocked_lock *nbl
+	),
+	TP_ARGS(lo, nbl),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, fh_hash)
+		__sockaddr(addr, lo->lo_owner.so_client->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		const struct nfs4_client *clp = lo->lo_owner.so_client;
+
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->fh_hash = knfsd_fh_hash(&nbl->nbl_fh);
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x fh_hash=0x%08x",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->fh_hash)
+);
+
+TRACE_EVENT(nfsd_cb_offload,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const stateid_t *stp,
+		const struct knfsd_fh *fh,
+		u64 count,
+		__be32 status
+	),
+	TP_ARGS(clp, stp, fh, count, status),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+		__field(u32, fh_hash)
+		__field(int, status)
+		__field(u64, count)
+		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+		__entry->fh_hash = knfsd_fh_hash(fh);
+		__entry->status = be32_to_cpu(status);
+		__entry->count = count;
+		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
+				  clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_printk("addr=%pISpc client %08x:%08x stateid %08x:%08x fh_hash=0x%08x count=%llu status=%d",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->si_id, __entry->si_generation,
+		__entry->fh_hash, __entry->count, __entry->status)
+);
+
+TRACE_EVENT(nfsd_cb_recall_any,
+	TP_PROTO(
+		const struct nfsd4_cb_recall_any *ra
+	),
+	TP_ARGS(ra),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, keep)
+		__field(unsigned long, bmval0)
+		__sockaddr(addr, ra->ra_cb.cb_clp->cl_cb_conn.cb_addrlen)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = ra->ra_cb.cb_clp->cl_clientid.cl_boot;
+		__entry->cl_id = ra->ra_cb.cb_clp->cl_clientid.cl_id;
+		__entry->keep = ra->ra_keep;
+		__entry->bmval0 = ra->ra_bmval[0];
+		__assign_sockaddr(addr, &ra->ra_cb.cb_clp->cl_addr,
+				  ra->ra_cb.cb_clp->cl_cb_conn.cb_addrlen);
+	),
+	TP_printk("addr=%pISpc client %08x:%08x keep=%u bmval0=%s",
+		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
+		__entry->keep, show_rca_mask(__entry->bmval0)
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_cb_done_class,
+	TP_PROTO(
+		const stateid_t *stp,
+		const struct rpc_task *task
+	),
+	TP_ARGS(stp, task),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+		__entry->status = task->tk_status;
+	),
+	TP_printk("client %08x:%08x stateid %08x:%08x status=%d",
+		__entry->cl_boot, __entry->cl_id, __entry->si_id,
+		__entry->si_generation, __entry->status
+	)
+);
+
+#define DEFINE_NFSD_CB_DONE_EVENT(name)			\
+DEFINE_EVENT(nfsd_cb_done_class, name,			\
+	TP_PROTO(					\
+		const stateid_t *stp,			\
+		const struct rpc_task *task		\
+	),						\
+	TP_ARGS(stp, task))
+
+DEFINE_NFSD_CB_DONE_EVENT(nfsd_cb_recall_done);
+DEFINE_NFSD_CB_DONE_EVENT(nfsd_cb_notify_lock_done);
+DEFINE_NFSD_CB_DONE_EVENT(nfsd_cb_layout_done);
+DEFINE_NFSD_CB_DONE_EVENT(nfsd_cb_offload_done);
+DEFINE_NFSD_CB_DONE_EVENT(nfsd_cb_getattr_done);
+
+TRACE_EVENT(nfsd_cb_recall_any_done,
+	TP_PROTO(
+		const struct nfsd4_callback *cb,
+		const struct rpc_task *task
+	),
+	TP_ARGS(cb, task),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->status = task->tk_status;
+		__entry->cl_boot = cb->cb_clp->cl_clientid.cl_boot;
+		__entry->cl_id = cb->cb_clp->cl_clientid.cl_id;
+	),
+	TP_printk("client %08x:%08x status=%d",
+		__entry->cl_boot, __entry->cl_id, __entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_unlock_ip,
+	TP_PROTO(
+		const struct net *net,
+		const struct sockaddr *addr,
+		const unsigned int addrlen
+	),
+	TP_ARGS(net, addr, addrlen),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__sockaddr(addr, addrlen)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__assign_sockaddr(addr, addr, addrlen);
+	),
+	TP_printk("addr=%pISpc",
+		__get_sockaddr(addr)
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_unlock_fs,
+	TP_PROTO(
+		const struct net *net,
+		const char *path
+	),
+	TP_ARGS(net, path),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__string(path, path)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__assign_str(path);
+	),
+	TP_printk("path=%s",
+		__get_str(path)
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_unlock_export,
+	TP_PROTO(
+		const struct net *net,
+		const char *path
+	),
+	TP_ARGS(net, path),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__string(path, path)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__assign_str(path);
+	),
+	TP_printk("path=%s",
+		__get_str(path)
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_filehandle,
+	TP_PROTO(
+		const struct net *net,
+		const char *domain,
+		const char *path,
+		int maxsize
+	),
+	TP_ARGS(net, domain, path, maxsize),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, maxsize)
+		__string(domain, domain)
+		__string(path, path)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->maxsize = maxsize;
+		__assign_str(domain);
+		__assign_str(path);
+	),
+	TP_printk("domain=%s path=%s maxsize=%d",
+		__get_str(domain), __get_str(path), __entry->maxsize
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_threads,
+	TP_PROTO(
+		const struct net *net,
+		int newthreads
+	),
+	TP_ARGS(net, newthreads),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, newthreads)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->newthreads = newthreads;
+	),
+	TP_printk("newthreads=%d",
+		__entry->newthreads
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_pool_threads,
+	TP_PROTO(
+		const struct net *net,
+		int pool,
+		int nrthreads
+	),
+	TP_ARGS(net, pool, nrthreads),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, pool)
+		__field(int, nrthreads)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->pool = pool;
+		__entry->nrthreads = nrthreads;
+	),
+	TP_printk("pool=%d nrthreads=%d",
+		__entry->pool, __entry->nrthreads
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_version,
+	TP_PROTO(
+		const struct net *net,
+		const char *mesg
+	),
+	TP_ARGS(net, mesg),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__string(mesg, mesg)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__assign_str(mesg);
+	),
+	TP_printk("%s",
+		__get_str(mesg)
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_ports_addfd,
+	TP_PROTO(
+		const struct net *net,
+		int fd
+	),
+	TP_ARGS(net, fd),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, fd)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->fd = fd;
+	),
+	TP_printk("fd=%d",
+		__entry->fd
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_ports_addxprt,
+	TP_PROTO(
+		const struct net *net,
+		const char *transport,
+		int port
+	),
+	TP_ARGS(net, transport, port),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, port)
+		__string(transport, transport)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->port = port;
+		__assign_str(transport);
+	),
+	TP_printk("transport=%s port=%d",
+		__get_str(transport), __entry->port
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_maxblksize,
+	TP_PROTO(
+		const struct net *net,
+		int bsize
+	),
+	TP_ARGS(net, bsize),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, bsize)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->bsize = bsize;
+	),
+	TP_printk("bsize=%d",
+		__entry->bsize
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_minthreads,
+	TP_PROTO(
+		const struct net *net,
+		int minthreads
+	),
+	TP_ARGS(net, minthreads),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, minthreads)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->minthreads = minthreads
+	),
+	TP_printk("minthreads=%d",
+		__entry->minthreads
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_time,
+	TP_PROTO(
+		const struct net *net,
+		const char *name,
+		size_t namelen,
+		int time
+	),
+	TP_ARGS(net, name, namelen, time),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__field(int, time)
+		__string_len(name, name, namelen)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__entry->time = time;
+		__assign_str(name);
+	),
+	TP_printk("file=%s time=%d",
+		__get_str(name), __entry->time
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_recoverydir,
+	TP_PROTO(
+		const struct net *net,
+		const char *recdir
+	),
+	TP_ARGS(net, recdir),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+		__string(recdir, recdir)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+		__assign_str(recdir);
+	),
+	TP_printk("recdir=%s",
+		__get_str(recdir)
+	)
+);
+
+TRACE_EVENT(nfsd_end_grace,
+	TP_PROTO(
+		const struct net *net
+	),
+	TP_ARGS(net),
+	TP_STRUCT__entry(
+		__field(unsigned int, netns_ino)
+	),
+	TP_fast_assign(
+		__entry->netns_ino = net->ns.inum;
+	),
+	TP_printk("nn=%d", __entry->netns_ino
+	)
+);
+
+TRACE_EVENT(nfsd_ctl_fh_key_set,
+	TP_PROTO(
+		bool changed,
+		int result
+	),
+	TP_ARGS(changed, result),
+	TP_STRUCT__entry(
+		__field(bool, changed)
+		__field(int, result)
+	),
+	TP_fast_assign(
+		__entry->changed = changed;
+		__entry->result = result;
+	),
+	TP_printk("key %s, result=%d",
+		__entry->changed ? "updated" : "unmodified",
+		__entry->result
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_copy_class,
+	TP_PROTO(
+		const struct nfsd4_copy *copy
+	),
+	TP_ARGS(copy),
+	TP_STRUCT__entry(
+		__field(bool, intra)
+		__field(bool, async)
+		__field(u32, src_cl_boot)
+		__field(u32, src_cl_id)
+		__field(u32, src_so_id)
+		__field(u32, src_si_generation)
+		__field(u32, dst_cl_boot)
+		__field(u32, dst_cl_id)
+		__field(u32, dst_so_id)
+		__field(u32, dst_si_generation)
+		__field(u32, cb_cl_boot)
+		__field(u32, cb_cl_id)
+		__field(u32, cb_so_id)
+		__field(u32, cb_si_generation)
+		__field(u64, src_cp_pos)
+		__field(u64, dst_cp_pos)
+		__field(u64, cp_count)
+		__sockaddr(addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		const stateid_t *src_stp = &copy->cp_src_stateid;
+		const stateid_t *dst_stp = &copy->cp_dst_stateid;
+		const stateid_t *cb_stp = &copy->cp_res.cb_stateid;
+
+		__entry->intra = test_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+		__entry->async = !test_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+		__entry->src_cl_boot = src_stp->si_opaque.so_clid.cl_boot;
+		__entry->src_cl_id = src_stp->si_opaque.so_clid.cl_id;
+		__entry->src_so_id = src_stp->si_opaque.so_id;
+		__entry->src_si_generation = src_stp->si_generation;
+		__entry->dst_cl_boot = dst_stp->si_opaque.so_clid.cl_boot;
+		__entry->dst_cl_id = dst_stp->si_opaque.so_clid.cl_id;
+		__entry->dst_so_id = dst_stp->si_opaque.so_id;
+		__entry->dst_si_generation = dst_stp->si_generation;
+		__entry->cb_cl_boot = cb_stp->si_opaque.so_clid.cl_boot;
+		__entry->cb_cl_id = cb_stp->si_opaque.so_clid.cl_id;
+		__entry->cb_so_id = cb_stp->si_opaque.so_id;
+		__entry->cb_si_generation = cb_stp->si_generation;
+		__entry->src_cp_pos = copy->cp_src_pos;
+		__entry->dst_cp_pos = copy->cp_dst_pos;
+		__entry->cp_count = copy->cp_count;
+		__assign_sockaddr(addr, &copy->cp_clp->cl_addr,
+				sizeof(struct sockaddr_in6));
+	),
+	TP_printk("client=%pISpc intra=%d async=%d "
+		"src_client %08x:%08x src_stateid %08x:%08x "
+		"dst_client %08x:%08x dst_stateid %08x:%08x "
+		"cb_client %08x:%08x cb_stateid %08x:%08x "
+		"cp_src_pos=%llu cp_dst_pos=%llu cp_count=%llu",
+		__get_sockaddr(addr), __entry->intra, __entry->async,
+		__entry->src_cl_boot, __entry->src_cl_id,
+		__entry->src_so_id, __entry->src_si_generation,
+		__entry->dst_cl_boot, __entry->dst_cl_id,
+		__entry->dst_so_id, __entry->dst_si_generation,
+		__entry->cb_cl_boot, __entry->cb_cl_id,
+		__entry->cb_so_id, __entry->cb_si_generation,
+		__entry->src_cp_pos, __entry->dst_cp_pos, __entry->cp_count
+	)
+);
+
+#define DEFINE_COPY_EVENT(name)				\
+DEFINE_EVENT(nfsd_copy_class, nfsd_copy_##name,	\
+	TP_PROTO(const struct nfsd4_copy *copy),	\
+	TP_ARGS(copy))
+
+DEFINE_COPY_EVENT(inter);
+DEFINE_COPY_EVENT(intra);
+DEFINE_COPY_EVENT(async);
+
+TRACE_EVENT(nfsd_copy_done,
+	TP_PROTO(
+		const struct nfsd4_copy *copy,
+		__be32 status
+	),
+	TP_ARGS(copy, status),
+	TP_STRUCT__entry(
+		__field(int, status)
+		__field(bool, intra)
+		__field(bool, async)
+		__sockaddr(addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->status = be32_to_cpu(status);
+		__entry->intra = test_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+		__entry->async = !test_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+		__assign_sockaddr(addr, &copy->cp_clp->cl_addr,
+				sizeof(struct sockaddr_in6));
+	),
+	TP_printk("addr=%pISpc status=%d intra=%d async=%d",
+		__get_sockaddr(addr), __entry->status, __entry->intra, __entry->async
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_copy_async_done_class,
+	TP_PROTO(
+		const struct nfsd4_copy *copy
+	),
+	TP_ARGS(copy),
+	TP_STRUCT__entry(
+		__field(int, status)
+		__field(bool, intra)
+		__field(bool, async)
+		__field(u32, src_cl_boot)
+		__field(u32, src_cl_id)
+		__field(u32, src_so_id)
+		__field(u32, src_si_generation)
+		__field(u32, dst_cl_boot)
+		__field(u32, dst_cl_id)
+		__field(u32, dst_so_id)
+		__field(u32, dst_si_generation)
+		__field(u32, cb_cl_boot)
+		__field(u32, cb_cl_id)
+		__field(u32, cb_so_id)
+		__field(u32, cb_si_generation)
+		__field(u64, src_cp_pos)
+		__field(u64, dst_cp_pos)
+		__field(u64, cp_count)
+		__sockaddr(addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		const stateid_t *src_stp = &copy->cp_src_stateid;
+		const stateid_t *dst_stp = &copy->cp_dst_stateid;
+		const stateid_t *cb_stp = &copy->cp_res.cb_stateid;
+
+		__entry->status = be32_to_cpu(copy->nfserr);
+		__entry->intra = test_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+		__entry->async = !test_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+		__entry->src_cl_boot = src_stp->si_opaque.so_clid.cl_boot;
+		__entry->src_cl_id = src_stp->si_opaque.so_clid.cl_id;
+		__entry->src_so_id = src_stp->si_opaque.so_id;
+		__entry->src_si_generation = src_stp->si_generation;
+		__entry->dst_cl_boot = dst_stp->si_opaque.so_clid.cl_boot;
+		__entry->dst_cl_id = dst_stp->si_opaque.so_clid.cl_id;
+		__entry->dst_so_id = dst_stp->si_opaque.so_id;
+		__entry->dst_si_generation = dst_stp->si_generation;
+		__entry->cb_cl_boot = cb_stp->si_opaque.so_clid.cl_boot;
+		__entry->cb_cl_id = cb_stp->si_opaque.so_clid.cl_id;
+		__entry->cb_so_id = cb_stp->si_opaque.so_id;
+		__entry->cb_si_generation = cb_stp->si_generation;
+		__entry->src_cp_pos = copy->cp_src_pos;
+		__entry->dst_cp_pos = copy->cp_dst_pos;
+		__entry->cp_count = copy->cp_count;
+		__assign_sockaddr(addr, &copy->cp_clp->cl_addr,
+				sizeof(struct sockaddr_in6));
+	),
+	TP_printk("client=%pISpc status=%d intra=%d async=%d "
+		"src_client %08x:%08x src_stateid %08x:%08x "
+		"dst_client %08x:%08x dst_stateid %08x:%08x "
+		"cb_client %08x:%08x cb_stateid %08x:%08x "
+		"cp_src_pos=%llu cp_dst_pos=%llu cp_count=%llu",
+		__get_sockaddr(addr),
+		__entry->status, __entry->intra, __entry->async,
+		__entry->src_cl_boot, __entry->src_cl_id,
+		__entry->src_so_id, __entry->src_si_generation,
+		__entry->dst_cl_boot, __entry->dst_cl_id,
+		__entry->dst_so_id, __entry->dst_si_generation,
+		__entry->cb_cl_boot, __entry->cb_cl_id,
+		__entry->cb_so_id, __entry->cb_si_generation,
+		__entry->src_cp_pos, __entry->dst_cp_pos, __entry->cp_count
+	)
+);
+
+#define DEFINE_COPY_ASYNC_DONE_EVENT(name)		\
+DEFINE_EVENT(nfsd_copy_async_done_class,		\
+	nfsd_copy_async_##name,				\
+	TP_PROTO(const struct nfsd4_copy *copy),	\
+	TP_ARGS(copy))
+
+DEFINE_COPY_ASYNC_DONE_EVENT(done);
+DEFINE_COPY_ASYNC_DONE_EVENT(cancel);
+
+TRACE_EVENT(nfsd_vfs_setattr,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		const struct iattr *iap,
+		const struct timespec64 *guardtime
+	),
+	TP_ARGS(rqstp, fhp, iap, guardtime),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__field(s64, gtime_tv_sec)
+		__field(u32, gtime_tv_nsec)
+		__field(unsigned int, ia_valid)
+		__field(loff_t, ia_size)
+		__field(uid_t, ia_uid)
+		__field(gid_t, ia_gid)
+		__field(umode_t, ia_mode)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->gtime_tv_sec = guardtime ? guardtime->tv_sec : 0;
+		__entry->gtime_tv_nsec = guardtime ? guardtime->tv_nsec : 0;
+		__entry->ia_valid = iap->ia_valid;
+		__entry->ia_size = iap->ia_size;
+		__entry->ia_uid = __kuid_val(iap->ia_uid);
+		__entry->ia_gid = __kgid_val(iap->ia_gid);
+		__entry->ia_mode = iap->ia_mode;
+	),
+	TP_printk(
+		"xid=0x%08x fh_hash=0x%08x ia_valid=%s ia_size=%llu ia_mode=0%o ia_uid=%u ia_gid=%u guard_time=%lld.%u",
+		__entry->xid, __entry->fh_hash, show_ia_valid_flags(__entry->ia_valid),
+		__entry->ia_size, __entry->ia_mode, __entry->ia_uid, __entry->ia_gid,
+		__entry->gtime_tv_sec, __entry->gtime_tv_nsec
+	)
+)
+
+TRACE_EVENT(nfsd_vfs_lookup,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		const char *name,
+		unsigned int len
+	),
+	TP_ARGS(rqstp, fhp, name, len),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__string_len(name, name, len)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__assign_str(name);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x name=%s",
+		__entry->xid, __entry->fh_hash, __get_str(name)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_create,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		umode_t type,
+		const char *name,
+		unsigned int len
+	),
+	TP_ARGS(rqstp, fhp, type, name, len),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__field(umode_t, type)
+		__string_len(name, name, len)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->type = type;
+		__assign_str(name);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x type=%s name=%s",
+		__entry->xid, __entry->fh_hash,
+		show_fs_file_type(__entry->type), __get_str(name)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_symlink,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		const char *name,
+		unsigned int namelen,
+		const char *target
+	),
+	TP_ARGS(rqstp, fhp, name, namelen, target),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__string_len(name, name, namelen)
+		__string(target, target)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__assign_str(name);
+		__assign_str(target);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x name=%s target=%s",
+		__entry->xid, __entry->fh_hash,
+		__get_str(name), __get_str(target)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_link,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *sfhp,
+		const struct svc_fh *tfhp,
+		const char *name,
+		unsigned int namelen
+	),
+	TP_ARGS(rqstp, sfhp, tfhp, name, namelen),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, sfh_hash)
+		__field(u32, tfh_hash)
+		__string_len(name, name, namelen)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->sfh_hash = knfsd_fh_hash(&sfhp->fh_handle);
+		__entry->tfh_hash = knfsd_fh_hash(&tfhp->fh_handle);
+		__assign_str(name);
+	),
+	TP_printk("xid=0x%08x src_fh=0x%08x tgt_fh=0x%08x name=%s",
+		__entry->xid, __entry->sfh_hash, __entry->tfh_hash,
+		__get_str(name)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_unlink,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		const char *name,
+		unsigned int len
+	),
+	TP_ARGS(rqstp, fhp, name, len),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__string_len(name, name, len)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__assign_str(name);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x name=%s",
+		__entry->xid, __entry->fh_hash,
+		__get_str(name)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_rename,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *sfhp,
+		const struct svc_fh *tfhp,
+		const char *source,
+		unsigned int sourcelen,
+		const char *target,
+		unsigned int targetlen
+	),
+	TP_ARGS(rqstp, sfhp, tfhp, source, sourcelen, target, targetlen),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, sfh_hash)
+		__field(u32, tfh_hash)
+		__string_len(source, source, sourcelen)
+		__string_len(target, target, targetlen)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->sfh_hash = knfsd_fh_hash(&sfhp->fh_handle);
+		__entry->tfh_hash = knfsd_fh_hash(&tfhp->fh_handle);
+		__assign_str(source);
+		__assign_str(target);
+	),
+	TP_printk("xid=0x%08x sfh_hash=0x%08x tfh_hash=0x%08x source=%s target=%s",
+		__entry->xid, __entry->sfh_hash, __entry->tfh_hash,
+		__get_str(source), __get_str(target)
+	)
+);
+
+TRACE_EVENT(nfsd_vfs_readdir,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		u32 count,
+		u64 offset
+	),
+	TP_ARGS(rqstp, fhp, count, offset),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__field(u32, count)
+		__field(u64, offset)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->count = count;
+		__entry->offset = offset;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x offset=%llu count=%u",
+		__entry->xid, __entry->fh_hash,
+		__entry->offset, __entry->count
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_vfs_getattr_class,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp
+	),
+	TP_ARGS(rqstp, fhp),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x",
+		__entry->xid, __entry->fh_hash
+	)
+);
+
+#define DEFINE_NFSD_VFS_GETATTR_EVENT(__name)		\
+DEFINE_EVENT(nfsd_vfs_getattr_class, __name,		\
+	TP_PROTO(					\
+		const struct svc_rqst *rqstp,		\
+		const struct svc_fh *fhp		\
+	),						\
+	TP_ARGS(rqstp, fhp))
+
+DEFINE_NFSD_VFS_GETATTR_EVENT(nfsd_vfs_getattr);
+DEFINE_NFSD_VFS_GETATTR_EVENT(nfsd_vfs_statfs);
+
+DECLARE_EVENT_CLASS(nfsd_pnfs_class,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const char *dev,
+		int error
+	),
+	TP_ARGS(clp, dev, error),
+	TP_STRUCT__entry(
+		__sockaddr(addr, sizeof(struct sockaddr_in6))
+		__field(unsigned int, netns_ino)
+		__string(dev, dev)
+		__field(int, error)
+	),
+	TP_fast_assign(
+		__assign_sockaddr(addr, &clp->cl_addr,
+				sizeof(struct sockaddr_in6));
+		__entry->netns_ino = clp->net->ns.inum;
+		__assign_str(dev);
+		__entry->error = error;
+	),
+	TP_printk("client=%pISpc nn=%d dev=%s error=%d",
+		__get_sockaddr(addr),
+		__entry->netns_ino,
+		__get_str(dev),
+		__entry->error
+	)
+);
+
+#define DEFINE_NFSD_PNFS_ERR_EVENT(name)		\
+DEFINE_EVENT(nfsd_pnfs_class, nfsd_pnfs_##name,	\
+	TP_PROTO(					\
+		const struct nfs4_client *clp,		\
+		const char *dev,				\
+		int error				\
+	),						\
+	TP_ARGS(clp, dev, error))
+
+DEFINE_NFSD_PNFS_ERR_EVENT(fence);
+#endif /* _NFSD_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
new file mode 100644
index 000000000..8923a9910
--- /dev/null
+++ b/fs/nfsd/vfs.c
@@ -0,0 +1,2998 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * File operations used by nfsd. Some of these have been ripped from
+ * other parts of the kernel because they weren't exported, others
+ * are partial duplicates with added or changed functionality.
+ *
+ * Note that several functions dget() the dentry upon which they want
+ * to act, most notably those that create directory entries. Response
+ * dentry's are dput()'d if necessary in the release callback.
+ * So if you notice code paths that apparently fail to dput() the
+ * dentry, don't worry--they have been taken care of.
+ *
+ * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
+ * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
+ */
+
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/splice.h>
+#include <linux/falloc.h>
+#include <linux/fcntl.h>
+#include <linux/namei.h>
+#include <linux/delay.h>
+#include <linux/fsnotify.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+#include <linux/jhash.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/exportfs.h>
+#include <linux/writeback.h>
+#include <linux/security.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/fileattr.h>
+
+#include "xdr3.h"
+
+#ifdef CONFIG_NFSD_V4
+#include "acl.h"
+#include "idmap.h"
+#include "xdr4.h"
+#endif /* CONFIG_NFSD_V4 */
+
+#include "nfsd.h"
+#include "netns.h"
+#include "stats.h"
+#include "vfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_FILEOP
+
+bool nfsd_disable_splice_read __read_mostly;
+u64 nfsd_io_cache_read __read_mostly = NFSD_IO_BUFFERED;
+u64 nfsd_io_cache_write __read_mostly = NFSD_IO_BUFFERED;
+
+/**
+ * nfserrno - Map Linux errnos to NFS errnos
+ * @errno: POSIX(-ish) error code to be mapped
+ *
+ * Returns the appropriate (net-endian) nfserr_* (or nfs_ok if errno is 0). If
+ * it's an error we don't expect, log it once and return nfserr_io.
+ */
+__be32
+nfserrno (int errno)
+{
+	static struct {
+		__be32	nfserr;
+		int	syserr;
+	} nfs_errtbl[] = {
+		{ nfs_ok, 0 },
+		{ nfserr_perm, -EPERM },
+		{ nfserr_noent, -ENOENT },
+		{ nfserr_io, -EIO },
+		{ nfserr_nxio, -ENXIO },
+		{ nfserr_fbig, -E2BIG },
+		{ nfserr_stale, -EBADF },
+		{ nfserr_acces, -EACCES },
+		{ nfserr_exist, -EEXIST },
+		{ nfserr_xdev, -EXDEV },
+		{ nfserr_nodev, -ENODEV },
+		{ nfserr_notdir, -ENOTDIR },
+		{ nfserr_isdir, -EISDIR },
+		{ nfserr_inval, -EINVAL },
+		{ nfserr_fbig, -EFBIG },
+		{ nfserr_nospc, -ENOSPC },
+		{ nfserr_rofs, -EROFS },
+		{ nfserr_mlink, -EMLINK },
+		{ nfserr_nametoolong, -ENAMETOOLONG },
+		{ nfserr_notempty, -ENOTEMPTY },
+		{ nfserr_dquot, -EDQUOT },
+		{ nfserr_stale, -ESTALE },
+		{ nfserr_jukebox, -ETIMEDOUT },
+		{ nfserr_jukebox, -ERESTARTSYS },
+		{ nfserr_jukebox, -EAGAIN },
+		{ nfserr_jukebox, -EWOULDBLOCK },
+		{ nfserr_jukebox, -ENOMEM },
+		{ nfserr_io, -ETXTBSY },
+		{ nfserr_notsupp, -EOPNOTSUPP },
+		{ nfserr_toosmall, -ETOOSMALL },
+		{ nfserr_serverfault, -ESERVERFAULT },
+		{ nfserr_serverfault, -ENFILE },
+		{ nfserr_io, -EREMOTEIO },
+		{ nfserr_stale, -EOPENSTALE },
+		{ nfserr_io, -EUCLEAN },
+		{ nfserr_perm, -ENOKEY },
+		{ nfserr_no_grace, -ENOGRACE},
+		{ nfserr_io, -EBADMSG },
+	};
+	int	i;
+
+	for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
+		if (nfs_errtbl[i].syserr == errno)
+			return nfs_errtbl[i].nfserr;
+	}
+	WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
+	return nfserr_io;
+}
+
+/* 
+ * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
+ * a mount point.
+ * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
+ *  or nfs_ok having possibly changed *dpp and *expp
+ */
+int
+nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 
+		        struct svc_export **expp)
+{
+	struct svc_export *exp = *expp, *exp2 = NULL;
+	struct dentry *dentry = *dpp;
+	struct path path = {.mnt = mntget(exp->ex_path.mnt),
+			    .dentry = dget(dentry)};
+	unsigned int follow_flags = 0;
+	int err = 0;
+
+	if (exp->ex_flags & NFSEXP_CROSSMOUNT)
+		follow_flags = LOOKUP_AUTOMOUNT;
+
+	err = follow_down(&path, follow_flags);
+	if (err < 0)
+		goto out;
+
+	if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
+	    nfsd_mountpoint(dentry, exp) == 2) {
+		/* This is only a mountpoint in some other namespace */
+		goto out;
+	}
+
+	exp2 = rqst_exp_get_by_name(rqstp, &path);
+	if (IS_ERR(exp2)) {
+		err = PTR_ERR(exp2);
+		exp2 = NULL;
+		/*
+		 * We normally allow NFS clients to continue
+		 * "underneath" a mountpoint that is not exported.
+		 * The exception is V4ROOT, where no traversal is ever
+		 * allowed without an explicit export of the new
+		 * directory.
+		 */
+		if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
+			err = 0;
+	} else if (nfsd_v4client(rqstp) ||
+		(exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
+		/* successfully crossed mount point */
+		/*
+		 * This is subtle: path.dentry is *not* on path.mnt
+		 * at this point.  The only reason we are safe is that
+		 * original mnt is pinned down by exp, so we should
+		 * put path *before* putting exp
+		 */
+		*dpp = path.dentry;
+		path.dentry = dentry;
+		*expp = exp2;
+		exp2 = exp;
+	}
+out:
+	path_put(&path);
+	if (exp2)
+		exp_put(exp2);
+	return err;
+}
+
+static void follow_to_parent(struct path *path)
+{
+	struct dentry *dp;
+
+	while (path->dentry == path->mnt->mnt_root && follow_up(path))
+		;
+	dp = dget_parent(path->dentry);
+	dput(path->dentry);
+	path->dentry = dp;
+}
+
+static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
+{
+	struct svc_export *exp2;
+	struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
+			    .dentry = dget(dparent)};
+
+	follow_to_parent(&path);
+
+	exp2 = rqst_exp_parent(rqstp, &path);
+	if (PTR_ERR(exp2) == -ENOENT) {
+		*dentryp = dget(dparent);
+	} else if (IS_ERR(exp2)) {
+		path_put(&path);
+		return PTR_ERR(exp2);
+	} else {
+		*dentryp = dget(path.dentry);
+		exp_put(*exp);
+		*exp = exp2;
+	}
+	path_put(&path);
+	return 0;
+}
+
+/*
+ * For nfsd purposes, we treat V4ROOT exports as though there was an
+ * export at *every* directory.
+ * We return:
+ * '1' if this dentry *must* be an export point,
+ * '2' if it might be, if there is really a mount here, and
+ * '0' if there is no chance of an export point here.
+ */
+int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
+{
+	if (!d_inode(dentry))
+		return 0;
+	if (exp->ex_flags & NFSEXP_V4ROOT)
+		return 1;
+	if (nfsd4_is_junction(dentry))
+		return 1;
+	if (d_managed(dentry))
+		/*
+		 * Might only be a mountpoint in a different namespace,
+		 * but we need to check.
+		 */
+		return 2;
+	return 0;
+}
+
+__be32
+nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		   const char *name, unsigned int len,
+		   struct svc_export **exp_ret, struct dentry **dentry_ret)
+{
+	struct svc_export	*exp;
+	struct dentry		*dparent;
+	struct dentry		*dentry;
+	int			host_err;
+
+	trace_nfsd_vfs_lookup(rqstp, fhp, name, len);
+
+	dparent = fhp->fh_dentry;
+	exp = exp_get(fhp->fh_export);
+
+	/* Lookup the name, but don't follow links */
+	if (name_is_dot_dotdot(name, len)) {
+		if (len==1)
+			dentry = dget(dparent);
+		else if (dparent != exp->ex_path.dentry)
+			dentry = dget_parent(dparent);
+		else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
+			dentry = dget(dparent); /* .. == . just like at / */
+		else {
+			/* checking mountpoint crossing is very different when stepping up */
+			host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
+			if (host_err)
+				goto out_nfserr;
+		}
+	} else {
+		dentry = lookup_one_unlocked(&nop_mnt_idmap,
+					     &QSTR_LEN(name, len), dparent);
+		host_err = PTR_ERR(dentry);
+		if (IS_ERR(dentry))
+			goto out_nfserr;
+		if (nfsd_mountpoint(dentry, exp)) {
+			host_err = nfsd_cross_mnt(rqstp, &dentry, &exp);
+			if (host_err) {
+				dput(dentry);
+				goto out_nfserr;
+			}
+		}
+	}
+	*dentry_ret = dentry;
+	*exp_ret = exp;
+	return 0;
+
+out_nfserr:
+	exp_put(exp);
+	return nfserrno(host_err);
+}
+
+/**
+ * nfsd_lookup - look up a single path component for nfsd
+ *
+ * @rqstp:   the request context
+ * @fhp:     the file handle of the directory
+ * @name:    the component name, or %NULL to look up parent
+ * @len:     length of name to examine
+ * @resfh:   pointer to pre-initialised filehandle to hold result.
+ *
+ * Look up one component of a pathname.
+ * N.B. After this call _both_ fhp and resfh need an fh_put
+ *
+ * If the lookup would cross a mountpoint, and the mounted filesystem
+ * is exported to the client with NFSEXP_NOHIDE, then the lookup is
+ * accepted as it stands and the mounted directory is
+ * returned. Otherwise the covered directory is returned.
+ * NOTE: this mountpoint crossing is not supported properly by all
+ *   clients and is explicitly disallowed for NFSv3
+ *
+ */
+__be32
+nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
+	    unsigned int len, struct svc_fh *resfh)
+{
+	struct svc_export	*exp;
+	struct dentry		*dentry;
+	__be32 err;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		return err;
+	err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
+	if (err)
+		return err;
+	err = check_nfsd_access(exp, rqstp, false);
+	if (err)
+		goto out;
+	/*
+	 * Note: we compose the file handle now, but as the
+	 * dentry may be negative, it may need to be updated.
+	 */
+	err = fh_compose(resfh, exp, dentry, fhp);
+	if (!err && d_really_is_negative(dentry))
+		err = nfserr_noent;
+out:
+	dput(dentry);
+	exp_put(exp);
+	return err;
+}
+
+static void
+commit_reset_write_verifier(struct nfsd_net *nn, struct svc_rqst *rqstp,
+			    int err)
+{
+	switch (err) {
+	case -EAGAIN:
+	case -ESTALE:
+		/*
+		 * Neither of these are the result of a problem with
+		 * durable storage, so avoid a write verifier reset.
+		 */
+		break;
+	default:
+		nfsd_reset_write_verifier(nn);
+		trace_nfsd_writeverf_reset(nn, rqstp, err);
+	}
+}
+
+/*
+ * Commit metadata changes to stable storage.
+ */
+static int
+commit_inode_metadata(struct inode *inode)
+{
+	const struct export_operations *export_ops = inode->i_sb->s_export_op;
+
+	if (export_ops->commit_metadata)
+		return export_ops->commit_metadata(inode);
+	return sync_inode_metadata(inode, 1);
+}
+
+static int
+commit_metadata(struct svc_fh *fhp)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+
+	if (!EX_ISSYNC(fhp->fh_export))
+		return 0;
+	return commit_inode_metadata(inode);
+}
+
+/*
+ * Go over the attributes and take care of the small differences between
+ * NFS semantics and what Linux expects.
+ */
+static void
+nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
+{
+	/* Ignore mode updates on symlinks */
+	if (S_ISLNK(inode->i_mode))
+		iap->ia_valid &= ~ATTR_MODE;
+
+	/* sanitize the mode change */
+	if (iap->ia_valid & ATTR_MODE) {
+		iap->ia_mode &= S_IALLUGO;
+		iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
+	}
+
+	/* Revoke setuid/setgid on chown */
+	if (!S_ISDIR(inode->i_mode) &&
+	    ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
+		iap->ia_valid |= ATTR_KILL_PRIV;
+		if (iap->ia_valid & ATTR_MODE) {
+			/* we're setting mode too, just clear the s*id bits */
+			iap->ia_mode &= ~S_ISUID;
+			if (iap->ia_mode & S_IXGRP)
+				iap->ia_mode &= ~S_ISGID;
+		} else {
+			/* set ATTR_KILL_* bits and let VFS handle it */
+			iap->ia_valid |= ATTR_KILL_SUID;
+			iap->ia_valid |=
+				setattr_should_drop_sgid(&nop_mnt_idmap, inode);
+		}
+	}
+}
+
+static __be32
+nfsd_may_truncate(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct iattr *iap)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+
+	if (iap->ia_size >= i_size_read(inode))
+		return nfs_ok;
+
+	return nfsd_permission(&rqstp->rq_cred, fhp->fh_export, fhp->fh_dentry,
+			       NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
+}
+
+static __be32
+nfsd_get_write_access(struct svc_fh *fhp)
+{
+	return nfserrno(get_write_access(d_inode(fhp->fh_dentry)));
+}
+
+static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
+{
+	int host_err;
+
+	if (iap->ia_valid & ATTR_SIZE) {
+		/*
+		 * RFC5661, Section 18.30.4:
+		 *   Changing the size of a file with SETATTR indirectly
+		 *   changes the time_modify and change attributes.
+		 *
+		 * (and similar for the older RFCs)
+		 */
+		struct iattr size_attr = {
+			.ia_valid	= ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
+			.ia_size	= iap->ia_size,
+		};
+
+		if (iap->ia_size < 0)
+			return -EFBIG;
+
+		host_err = notify_change(&nop_mnt_idmap, dentry, &size_attr, NULL);
+		if (host_err)
+			return host_err;
+		iap->ia_valid &= ~ATTR_SIZE;
+
+		/*
+		 * Avoid the additional setattr call below if the only other
+		 * attribute that the client sends is the mtime, as we update
+		 * it as part of the size change above.
+		 */
+		if ((iap->ia_valid & ~ATTR_MTIME) == 0)
+			return 0;
+	}
+
+	if ((iap->ia_valid & ~ATTR_DELEG) == 0)
+		return 0;
+
+	/*
+	 * If ATTR_DELEG is set, then this is an update from a client that
+	 * holds a delegation. If this is an update for only the atime, the
+	 * ctime should not be changed. If the update contains the mtime
+	 * too, then ATTR_CTIME should already be set.
+	 */
+	if (!(iap->ia_valid & ATTR_DELEG))
+		iap->ia_valid |= ATTR_CTIME;
+
+	return notify_change(&nop_mnt_idmap, dentry, iap, NULL);
+}
+
+/**
+ * nfsd_setattr - Set various file attributes.
+ * @rqstp: controlling RPC transaction
+ * @fhp: filehandle of target
+ * @attr: attributes to set
+ * @guardtime: do not act if ctime.tv_sec does not match this timestamp
+ *
+ * This call may adjust the contents of @attr (in particular, this
+ * call may change the bits in the na_iattr.ia_valid field).
+ *
+ * Returns nfs_ok on success, otherwise an NFS status code is
+ * returned. Caller must release @fhp by calling fh_put in either
+ * case.
+ */
+__be32
+nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+	     struct nfsd_attrs *attr, const struct timespec64 *guardtime)
+{
+	struct dentry	*dentry;
+	struct inode	*inode;
+	struct iattr	*iap = attr->na_iattr;
+	int		accmode = NFSD_MAY_SATTR;
+	umode_t		ftype = 0;
+	__be32		err;
+	int		host_err = 0;
+	bool		get_write_count;
+	bool		size_change = (iap->ia_valid & ATTR_SIZE);
+	int		retries;
+
+	trace_nfsd_vfs_setattr(rqstp, fhp, iap, guardtime);
+
+	if (iap->ia_valid & ATTR_SIZE) {
+		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
+		ftype = S_IFREG;
+	}
+
+	/*
+	 * If utimes(2) and friends are called with times not NULL, we should
+	 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
+	 * will return EACCES, when the caller's effective UID does not match
+	 * the owner of the file, and the caller is not privileged. In this
+	 * situation, we should return EPERM(notify_change will return this).
+	 */
+	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
+		accmode |= NFSD_MAY_OWNER_OVERRIDE;
+		if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
+			accmode |= NFSD_MAY_WRITE;
+	}
+
+	/* Callers that do fh_verify should do the fh_want_write: */
+	get_write_count = !fhp->fh_dentry;
+
+	/* Get inode */
+	err = fh_verify(rqstp, fhp, ftype, accmode);
+	if (err)
+		return err;
+	if (get_write_count) {
+		host_err = fh_want_write(fhp);
+		if (host_err)
+			goto out;
+	}
+
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+
+	nfsd_sanitize_attrs(inode, iap);
+
+	/*
+	 * The size case is special, it changes the file in addition to the
+	 * attributes, and file systems don't expect it to be mixed with
+	 * "random" attribute changes.  We thus split out the size change
+	 * into a separate call to ->setattr, and do the rest as a separate
+	 * setattr call.
+	 */
+	if (size_change) {
+		err = nfsd_get_write_access(fhp);
+		if (err)
+			return err;
+	}
+
+	inode_lock(inode);
+	if (size_change) {
+		err = nfsd_may_truncate(rqstp, fhp, iap);
+		if (err)
+			goto out_unlock;
+	}
+	err = fh_fill_pre_attrs(fhp);
+	if (err)
+		goto out_unlock;
+
+	if (guardtime) {
+		struct timespec64 ctime = inode_get_ctime(inode);
+		if ((u32)guardtime->tv_sec != (u32)ctime.tv_sec ||
+		    guardtime->tv_nsec != ctime.tv_nsec) {
+			err = nfserr_notsync;
+			goto out_fill_attrs;
+		}
+	}
+
+	for (retries = 1;;) {
+		struct iattr attrs;
+
+		/*
+		 * notify_change() can alter its iattr argument, making
+		 * @iap unsuitable for submission multiple times. Make a
+		 * copy for every loop iteration.
+		 */
+		attrs = *iap;
+		host_err = __nfsd_setattr(dentry, &attrs);
+		if (host_err != -EAGAIN || !retries--)
+			break;
+		if (!nfsd_wait_for_delegreturn(rqstp, inode))
+			break;
+	}
+	if (attr->na_seclabel && attr->na_seclabel->len)
+		attr->na_labelerr = security_inode_setsecctx(dentry,
+			attr->na_seclabel->data, attr->na_seclabel->len);
+	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_dpacl) {
+		if (!S_ISDIR(inode->i_mode))
+			attr->na_dpaclerr = -EINVAL;
+		else if (attr->na_dpacl->a_count > 0)
+			/* a_count == 0 means delete the ACL. */
+			attr->na_dpaclerr = set_posix_acl(&nop_mnt_idmap,
+						dentry, ACL_TYPE_DEFAULT,
+						attr->na_dpacl);
+		else
+			attr->na_dpaclerr = set_posix_acl(&nop_mnt_idmap,
+						dentry, ACL_TYPE_DEFAULT,
+						NULL);
+	}
+	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl) {
+		/*
+		 * For any file system that is not ACL_SCOPE_FILE_OBJECT,
+		 * a_count == 0 MUST reply nfserr_inval.
+		 * For a file system that is ACL_SCOPE_FILE_OBJECT,
+		 * a_count == 0 deletes the ACL.
+		 * XXX File systems that are ACL_SCOPE_FILE_OBJECT
+		 * are not yet supported.
+		 */
+		if (attr->na_pacl->a_count > 0)
+			attr->na_paclerr = set_posix_acl(&nop_mnt_idmap,
+							dentry, ACL_TYPE_ACCESS,
+							attr->na_pacl);
+		else
+			attr->na_paclerr = -EINVAL;
+	}
+out_fill_attrs:
+	/*
+	 * RFC 1813 Section 3.3.2 does not mandate that an NFS server
+	 * returns wcc_data for SETATTR. Some client implementations
+	 * depend on receiving wcc_data, however, to sort out partial
+	 * updates (eg., the client requested that size and mode be
+	 * modified, but the server changed only the file mode).
+	 */
+	fh_fill_post_attrs(fhp);
+out_unlock:
+	inode_unlock(inode);
+	if (size_change)
+		put_write_access(inode);
+out:
+	if (!host_err)
+		host_err = commit_metadata(fhp);
+	return err != 0 ? err : nfserrno(host_err);
+}
+
+#if defined(CONFIG_NFSD_V4)
+/*
+ * NFS junction information is stored in an extended attribute.
+ */
+#define NFSD_JUNCTION_XATTR_NAME	XATTR_TRUSTED_PREFIX "junction.nfs"
+
+/**
+ * nfsd4_is_junction - Test if an object could be an NFS junction
+ *
+ * @dentry: object to test
+ *
+ * Returns 1 if "dentry" appears to contain NFS junction information.
+ * Otherwise 0 is returned.
+ */
+int nfsd4_is_junction(struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (inode == NULL)
+		return 0;
+	if (inode->i_mode & S_IXUGO)
+		return 0;
+	if (!(inode->i_mode & S_ISVTX))
+		return 0;
+	if (vfs_getxattr(&nop_mnt_idmap, dentry, NFSD_JUNCTION_XATTR_NAME,
+			 NULL, 0) <= 0)
+		return 0;
+	return 1;
+}
+
+static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
+{
+	return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
+}
+
+__be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
+		struct nfsd_file *nf_src, u64 src_pos,
+		struct nfsd_file *nf_dst, u64 dst_pos,
+		u64 count, bool sync)
+{
+	struct file *src = nf_src->nf_file;
+	struct file *dst = nf_dst->nf_file;
+	errseq_t since;
+	loff_t cloned;
+	__be32 ret = 0;
+
+	since = READ_ONCE(dst->f_wb_err);
+	cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
+	if (cloned < 0) {
+		ret = nfserrno(cloned);
+		goto out_err;
+	}
+	if (count && cloned != count) {
+		ret = nfserrno(-EINVAL);
+		goto out_err;
+	}
+	if (sync) {
+		loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
+		int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
+
+		if (!status)
+			status = filemap_check_wb_err(dst->f_mapping, since);
+		if (!status)
+			status = commit_inode_metadata(file_inode(src));
+		if (status < 0) {
+			struct nfsd_net *nn = net_generic(nf_dst->nf_net,
+							  nfsd_net_id);
+
+			trace_nfsd_clone_file_range_err(rqstp,
+					&nfsd4_get_cstate(rqstp)->save_fh,
+					src_pos,
+					&nfsd4_get_cstate(rqstp)->current_fh,
+					dst_pos,
+					count, status);
+			commit_reset_write_verifier(nn, rqstp, status);
+			ret = nfserrno(status);
+		}
+	}
+out_err:
+	return ret;
+}
+
+ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
+			     u64 dst_pos, u64 count)
+{
+	ssize_t ret;
+
+	/*
+	 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
+	 * thread and client rpc slot.  The choice of 4MB is somewhat
+	 * arbitrary.  We might instead base this on r/wsize, or make it
+	 * tunable, or use a time instead of a byte limit, or implement
+	 * asynchronous copy.  In theory a client could also recognize a
+	 * limit like this and pipeline multiple COPY requests.
+	 */
+	count = min_t(u64, count, 1 << 22);
+	ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+
+	if (ret == -EOPNOTSUPP || ret == -EXDEV)
+		ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
+					  COPY_FILE_SPLICE);
+	return ret;
+}
+
+__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			   struct file *file, loff_t offset, loff_t len,
+			   int flags)
+{
+	int error;
+
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return nfserr_inval;
+
+	error = vfs_fallocate(file, flags, offset, len);
+	if (!error)
+		error = commit_metadata(fhp);
+
+	return nfserrno(error);
+}
+#endif /* defined(CONFIG_NFSD_V4) */
+
+/*
+ * Check server access rights to a file system object
+ */
+struct accessmap {
+	u32		access;
+	int		how;
+};
+static struct accessmap	nfs3_regaccess[] = {
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_TRUNC	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE			},
+
+#ifdef CONFIG_NFSD_V4
+    {	NFS4_ACCESS_XAREAD,	NFSD_MAY_READ			},
+    {	NFS4_ACCESS_XAWRITE,	NFSD_MAY_WRITE			},
+    {	NFS4_ACCESS_XALIST,	NFSD_MAY_READ			},
+#endif
+
+    {	0,			0				}
+};
+
+static struct accessmap	nfs3_diraccess[] = {
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_LOOKUP,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_EXEC|NFSD_MAY_WRITE	},
+    {	NFS3_ACCESS_DELETE,	NFSD_MAY_REMOVE			},
+
+#ifdef CONFIG_NFSD_V4
+    {	NFS4_ACCESS_XAREAD,	NFSD_MAY_READ			},
+    {	NFS4_ACCESS_XAWRITE,	NFSD_MAY_WRITE			},
+    {	NFS4_ACCESS_XALIST,	NFSD_MAY_READ			},
+#endif
+
+    {	0,			0				}
+};
+
+static struct accessmap	nfs3_anyaccess[] = {
+	/* Some clients - Solaris 2.6 at least, make an access call
+	 * to the server to check for access for things like /dev/null
+	 * (which really, the server doesn't care about).  So
+	 * We provide simple access checking for them, looking
+	 * mainly at mode bits, and we make sure to ignore read-only
+	 * filesystem checks
+	 */
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS	},
+
+    {	0,			0				}
+};
+
+__be32
+nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
+{
+	struct accessmap	*map;
+	struct svc_export	*export;
+	struct dentry		*dentry;
+	u32			query, result = 0, sresult = 0;
+	__be32			error;
+
+	error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
+	if (error)
+		goto out;
+
+	export = fhp->fh_export;
+	dentry = fhp->fh_dentry;
+
+	if (d_is_reg(dentry))
+		map = nfs3_regaccess;
+	else if (d_is_dir(dentry))
+		map = nfs3_diraccess;
+	else
+		map = nfs3_anyaccess;
+
+
+	query = *access;
+	for  (; map->access; map++) {
+		if (map->access & query) {
+			__be32 err2;
+
+			sresult |= map->access;
+
+			err2 = nfsd_permission(&rqstp->rq_cred, export,
+					       dentry, map->how);
+			switch (err2) {
+			case nfs_ok:
+				result |= map->access;
+				break;
+				
+			/* the following error codes just mean the access was not allowed,
+			 * rather than an error occurred */
+			case nfserr_rofs:
+			case nfserr_acces:
+			case nfserr_perm:
+				/* simply don't "or" in the access bit. */
+				break;
+			default:
+				error = err2;
+				goto out;
+			}
+		}
+	}
+	*access = result;
+	if (supported)
+		*supported = sresult;
+
+ out:
+	return error;
+}
+
+int nfsd_open_break_lease(struct inode *inode, int access)
+{
+	unsigned int mode;
+
+	if (access & NFSD_MAY_NOT_BREAK_LEASE)
+		return 0;
+	mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
+	return break_lease(inode, mode | O_NONBLOCK);
+}
+
+/*
+ * Open an existing file or directory.
+ * The may_flags argument indicates the type of open (read/write/lock)
+ * and additional flags.
+ * N.B. After this call fhp needs an fh_put
+ */
+static int
+__nfsd_open(struct svc_fh *fhp, umode_t type, int may_flags, struct file **filp)
+{
+	struct path	path;
+	struct inode	*inode;
+	struct file	*file;
+	int		flags = O_RDONLY|O_LARGEFILE;
+	int		host_err = -EPERM;
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+	inode = d_inode(path.dentry);
+
+	if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
+		goto out;
+
+	if (!inode->i_fop)
+		goto out;
+
+	host_err = nfsd_open_break_lease(inode, may_flags);
+	if (host_err) /* NOMEM or WOULDBLOCK */
+		goto out;
+
+	if (may_flags & NFSD_MAY_WRITE) {
+		if (may_flags & NFSD_MAY_READ)
+			flags = O_RDWR|O_LARGEFILE;
+		else
+			flags = O_WRONLY|O_LARGEFILE;
+	}
+
+	file = dentry_open(&path, flags, current_cred());
+	if (IS_ERR(file)) {
+		host_err = PTR_ERR(file);
+		goto out;
+	}
+
+	host_err = security_file_post_open(file, may_flags);
+	if (host_err) {
+		fput(file);
+		goto out;
+	}
+
+	*filp = file;
+out:
+	return host_err;
+}
+
+__be32
+nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+		int may_flags, struct file **filp)
+{
+	__be32 err;
+	int host_err;
+	bool retried = false;
+
+	/*
+	 * If we get here, then the client has already done an "open",
+	 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
+	 * in case a chmod has now revoked permission.
+	 *
+	 * Arguably we should also allow the owner override for
+	 * directories, but we never have and it doesn't seem to have
+	 * caused anyone a problem.  If we were to change this, note
+	 * also that our filldir callbacks would need a variant of
+	 * lookup_one_positive_unlocked() that doesn't check permissions.
+	 */
+	if (type == S_IFREG)
+		may_flags |= NFSD_MAY_OWNER_OVERRIDE;
+retry:
+	err = fh_verify(rqstp, fhp, type, may_flags);
+	if (!err) {
+		host_err = __nfsd_open(fhp, type, may_flags, filp);
+		if (host_err == -EOPENSTALE && !retried) {
+			retried = true;
+			fh_put(fhp);
+			goto retry;
+		}
+		err = nfserrno(host_err);
+	}
+	return err;
+}
+
+/**
+ * nfsd_open_verified - Open a regular file for the filecache
+ * @fhp: NFS filehandle of the file to open
+ * @type: S_IFMT inode type allowed (0 means any type is allowed)
+ * @may_flags: internal permission flags
+ * @filp: OUT: open "struct file *"
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int
+nfsd_open_verified(struct svc_fh *fhp, umode_t type, int may_flags, struct file **filp)
+{
+	return __nfsd_open(fhp, type, may_flags, filp);
+}
+
+/*
+ * Grab and keep cached pages associated with a file in the svc_rqst
+ * so that they can be passed to the network sendmsg routines
+ * directly. They will be released after the sending has completed.
+ *
+ * Return values: Number of bytes consumed, or -EIO if there are no
+ * remaining pages in rqstp->rq_pages.
+ */
+static int
+nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
+		  struct splice_desc *sd)
+{
+	struct svc_rqst *rqstp = sd->u.data;
+	struct page *page = buf->page;	// may be a compound one
+	unsigned offset = buf->offset;
+	struct page *last_page;
+
+	last_page = page + (offset + sd->len - 1) / PAGE_SIZE;
+	for (page += offset / PAGE_SIZE; page <= last_page; page++) {
+		/*
+		 * Skip page replacement when extending the contents of the
+		 * current page.  But note that we may get two zero_pages in a
+		 * row from shmem.
+		 */
+		if (page == *(rqstp->rq_next_page - 1) &&
+		    offset_in_page(rqstp->rq_res.page_base +
+				   rqstp->rq_res.page_len))
+			continue;
+		if (unlikely(!svc_rqst_replace_page(rqstp, page)))
+			return -EIO;
+	}
+	if (rqstp->rq_res.page_len == 0)	// first call
+		rqstp->rq_res.page_base = offset % PAGE_SIZE;
+	rqstp->rq_res.page_len += sd->len;
+	return sd->len;
+}
+
+static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
+				    struct splice_desc *sd)
+{
+	return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
+}
+
+static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
+		size_t expected)
+{
+	if (expected != 0 && len == 0)
+		return 1;
+	if (offset+len >= i_size_read(file_inode(file)))
+		return 1;
+	return 0;
+}
+
+static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			       struct file *file, loff_t offset,
+			       unsigned long *count, u32 *eof, ssize_t host_err)
+{
+	if (host_err >= 0) {
+		struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+		nfsd_stats_io_read_add(nn, fhp->fh_export, host_err);
+		*eof = nfsd_eof_on_read(file, offset, host_err, *count);
+		*count = host_err;
+		fsnotify_access(file);
+		trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
+		return 0;
+	} else {
+		trace_nfsd_read_err(rqstp, fhp, offset, host_err);
+		return nfserrno(host_err);
+	}
+}
+
+/**
+ * nfsd_splice_read - Perform a VFS read using a splice pipe
+ * @rqstp: RPC transaction context
+ * @fhp: file handle of file to be read
+ * @file: opened struct file of file to be read
+ * @offset: starting byte offset
+ * @count: IN: requested number of bytes; OUT: number of bytes read
+ * @eof: OUT: set non-zero if operation reached the end of the file
+ *
+ * Returns nfs_ok on success, otherwise an nfserr stat value is
+ * returned.
+ */
+__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			struct file *file, loff_t offset, unsigned long *count,
+			u32 *eof)
+{
+	struct splice_desc sd = {
+		.len		= 0,
+		.total_len	= *count,
+		.pos		= offset,
+		.u.data		= rqstp,
+	};
+	ssize_t host_err;
+
+	trace_nfsd_read_splice(rqstp, fhp, offset, *count);
+	host_err = rw_verify_area(READ, file, &offset, *count);
+	if (!host_err)
+		host_err = splice_direct_to_actor(file, &sd,
+						  nfsd_direct_splice_actor);
+	return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
+}
+
+/*
+ * The byte range of the client's READ request is expanded on both ends
+ * until it meets the underlying file system's direct I/O alignment
+ * requirements. After the internal read is complete, the byte range of
+ * the NFS READ payload is reduced to the byte range that was originally
+ * requested.
+ *
+ * Note that a direct read can be done only when the xdr_buf containing
+ * the NFS READ reply does not already have contents in its .pages array.
+ * This is due to potentially restrictive alignment requirements on the
+ * read buffer. When .page_len and @base are zero, the .pages array is
+ * guaranteed to be page-aligned.
+ */
+static noinline_for_stack __be32
+nfsd_direct_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		 struct nfsd_file *nf, loff_t offset, unsigned long *count,
+		 u32 *eof)
+{
+	u64 dio_start, dio_end;
+	unsigned long v, total;
+	struct iov_iter iter;
+	struct kiocb kiocb;
+	ssize_t host_err;
+	size_t len;
+
+	init_sync_kiocb(&kiocb, nf->nf_file);
+	kiocb.ki_flags |= IOCB_DIRECT;
+
+	/* Read a properly-aligned region of bytes into rq_bvec */
+	dio_start = round_down(offset, nf->nf_dio_read_offset_align);
+	dio_end = round_up((u64)offset + *count, nf->nf_dio_read_offset_align);
+
+	kiocb.ki_pos = dio_start;
+
+	v = 0;
+	total = dio_end - dio_start;
+	while (total && v < rqstp->rq_maxpages &&
+	       rqstp->rq_next_page < rqstp->rq_page_end) {
+		len = min_t(size_t, total, PAGE_SIZE);
+		bvec_set_page(&rqstp->rq_bvec[v], *rqstp->rq_next_page,
+			      len, 0);
+
+		total -= len;
+		++rqstp->rq_next_page;
+		++v;
+	}
+
+	trace_nfsd_read_direct(rqstp, fhp, offset, *count - total);
+	iov_iter_bvec(&iter, ITER_DEST, rqstp->rq_bvec, v,
+		      dio_end - dio_start - total);
+
+	host_err = vfs_iocb_iter_read(nf->nf_file, &kiocb, &iter);
+	if (host_err >= 0) {
+		unsigned int pad = offset - dio_start;
+
+		/* The returned payload starts after the pad */
+		rqstp->rq_res.page_base = pad;
+
+		/* Compute the count of bytes to be returned */
+		if (host_err > pad + *count)
+			host_err = *count;
+		else if (host_err > pad)
+			host_err -= pad;
+		else
+			host_err = 0;
+	} else if (unlikely(host_err == -EINVAL)) {
+		struct inode *inode = d_inode(fhp->fh_dentry);
+
+		pr_info_ratelimited("nfsd: Direct I/O alignment failure on %s/%llu\n",
+				    inode->i_sb->s_id, inode->i_ino);
+		host_err = -ESERVERFAULT;
+	}
+
+	return nfsd_finish_read(rqstp, fhp, nf->nf_file, offset, count,
+				eof, host_err);
+}
+
+/**
+ * nfsd_iter_read - Perform a VFS read using an iterator
+ * @rqstp: RPC transaction context
+ * @fhp: file handle of file to be read
+ * @nf: opened struct nfsd_file of file to be read
+ * @offset: starting byte offset
+ * @count: IN: requested number of bytes; OUT: number of bytes read
+ * @base: offset in first page of read buffer
+ * @eof: OUT: set non-zero if operation reached the end of the file
+ *
+ * Some filesystems or situations cannot use nfsd_splice_read. This
+ * function is the slightly less-performant fallback for those cases.
+ *
+ * Returns nfs_ok on success, otherwise an nfserr stat value is
+ * returned.
+ */
+__be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		      struct nfsd_file *nf, loff_t offset, unsigned long *count,
+		      unsigned int base, u32 *eof)
+{
+	struct file *file = nf->nf_file;
+	unsigned long v, total;
+	struct iov_iter iter;
+	struct kiocb kiocb;
+	ssize_t host_err;
+	size_t len;
+
+	init_sync_kiocb(&kiocb, file);
+
+	switch (nfsd_io_cache_read) {
+	case NFSD_IO_BUFFERED:
+		break;
+	case NFSD_IO_DIRECT:
+		/* When dio_read_offset_align is zero, dio is not supported */
+		if (nf->nf_dio_read_offset_align && !rqstp->rq_res.page_len)
+			return nfsd_direct_read(rqstp, fhp, nf, offset,
+						count, eof);
+		fallthrough;
+	case NFSD_IO_DONTCACHE:
+		if (file->f_op->fop_flags & FOP_DONTCACHE)
+			kiocb.ki_flags = IOCB_DONTCACHE;
+		break;
+	}
+
+	kiocb.ki_pos = offset;
+
+	v = 0;
+	total = *count;
+	while (total && v < rqstp->rq_maxpages &&
+	       rqstp->rq_next_page < rqstp->rq_page_end) {
+		len = min_t(size_t, total, PAGE_SIZE - base);
+		bvec_set_page(&rqstp->rq_bvec[v], *rqstp->rq_next_page,
+			      len, base);
+
+		total -= len;
+		++rqstp->rq_next_page;
+		++v;
+		base = 0;
+	}
+
+	trace_nfsd_read_vector(rqstp, fhp, offset, *count - total);
+	iov_iter_bvec(&iter, ITER_DEST, rqstp->rq_bvec, v, *count - total);
+	host_err = vfs_iocb_iter_read(file, &kiocb, &iter);
+	return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
+}
+
+/*
+ * Gathered writes: If another process is currently writing to the file,
+ * there's a high chance this is another nfsd (triggered by a bulk write
+ * from a client's biod). Rather than syncing the file with each write
+ * request, we sleep for 10 msec.
+ *
+ * I don't know if this roughly approximates C. Juszak's idea of
+ * gathered writes, but it's a nice and simple solution (IMHO), and it
+ * seems to work:-)
+ *
+ * Note: we do this only in the NFSv2 case, since v3 and higher have a
+ * better tool (separate unstable writes and commits) for solving this
+ * problem.
+ */
+static int wait_for_concurrent_writes(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	static ino_t last_ino;
+	static dev_t last_dev;
+	int err = 0;
+
+	if (atomic_read(&inode->i_writecount) > 1
+	    || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
+		dprintk("nfsd: write defer %d\n", task_pid_nr(current));
+		msleep(10);
+		dprintk("nfsd: write resume %d\n", task_pid_nr(current));
+	}
+
+	if (inode_state_read_once(inode) & I_DIRTY) {
+		dprintk("nfsd: write sync %d\n", task_pid_nr(current));
+		err = vfs_fsync(file, 0);
+	}
+	last_ino = inode->i_ino;
+	last_dev = inode->i_sb->s_dev;
+	return err;
+}
+
+struct nfsd_write_dio_seg {
+	struct iov_iter			iter;
+	int				flags;
+};
+
+static unsigned long
+iov_iter_bvec_offset(const struct iov_iter *iter)
+{
+	return (unsigned long)(iter->bvec->bv_offset + iter->iov_offset);
+}
+
+static void
+nfsd_write_dio_seg_init(struct nfsd_write_dio_seg *segment,
+			struct bio_vec *bvec, unsigned int nvecs,
+			unsigned long total, size_t start, size_t len,
+			struct kiocb *iocb)
+{
+	iov_iter_bvec(&segment->iter, ITER_SOURCE, bvec, nvecs, total);
+	if (start)
+		iov_iter_advance(&segment->iter, start);
+	iov_iter_truncate(&segment->iter, len);
+	segment->flags = iocb->ki_flags;
+}
+
+static unsigned int
+nfsd_write_dio_iters_init(struct nfsd_file *nf, struct bio_vec *bvec,
+			  unsigned int nvecs, struct kiocb *iocb,
+			  unsigned long total,
+			  struct nfsd_write_dio_seg segments[3])
+{
+	u32 offset_align = nf->nf_dio_offset_align;
+	loff_t prefix_end, orig_end, middle_end;
+	u32 mem_align = nf->nf_dio_mem_align;
+	size_t prefix, middle, suffix;
+	loff_t offset = iocb->ki_pos;
+	unsigned int nsegs = 0;
+
+	/*
+	 * Check if direct I/O is feasible for this write request.
+	 * If alignments are not available, the write is too small,
+	 * or no alignment can be found, fall back to buffered I/O.
+	 */
+	if (unlikely(!mem_align || !offset_align) ||
+	    unlikely(total < max(offset_align, mem_align)))
+		goto no_dio;
+
+	prefix_end = round_up(offset, offset_align);
+	orig_end = offset + total;
+	middle_end = round_down(orig_end, offset_align);
+
+	prefix = prefix_end - offset;
+	middle = middle_end - prefix_end;
+	suffix = orig_end - middle_end;
+
+	if (!middle)
+		goto no_dio;
+
+	if (prefix)
+		nfsd_write_dio_seg_init(&segments[nsegs++], bvec,
+					nvecs, total, 0, prefix, iocb);
+
+	nfsd_write_dio_seg_init(&segments[nsegs], bvec, nvecs,
+				total, prefix, middle, iocb);
+
+	/*
+	 * Check if the bvec iterator is aligned for direct I/O.
+	 *
+	 * bvecs generated from RPC receive buffers are contiguous: After
+	 * the first bvec, all subsequent bvecs start at bv_offset zero
+	 * (page-aligned). Therefore, only the first bvec is checked.
+	 */
+	if (iov_iter_bvec_offset(&segments[nsegs].iter) & (mem_align - 1))
+		goto no_dio;
+	segments[nsegs].flags |= IOCB_DIRECT;
+	nsegs++;
+
+	if (suffix)
+		nfsd_write_dio_seg_init(&segments[nsegs++], bvec, nvecs, total,
+					prefix + middle, suffix, iocb);
+
+	return nsegs;
+
+no_dio:
+	/* No DIO alignment possible - pack into single non-DIO segment. */
+	nfsd_write_dio_seg_init(&segments[0], bvec, nvecs, total, 0,
+				total, iocb);
+	return 1;
+}
+
+static noinline_for_stack int
+nfsd_direct_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct nfsd_file *nf, unsigned int nvecs,
+		  unsigned long *cnt, struct kiocb *kiocb)
+{
+	struct nfsd_write_dio_seg segments[3];
+	struct file *file = nf->nf_file;
+	unsigned int nsegs, i;
+	ssize_t host_err;
+	size_t expected;
+
+	nsegs = nfsd_write_dio_iters_init(nf, rqstp->rq_bvec, nvecs,
+					  kiocb, *cnt, segments);
+
+	*cnt = 0;
+	for (i = 0; i < nsegs; i++) {
+		kiocb->ki_flags = segments[i].flags;
+		if (kiocb->ki_flags & IOCB_DIRECT)
+			trace_nfsd_write_direct(rqstp, fhp, kiocb->ki_pos,
+						segments[i].iter.count);
+		else {
+			trace_nfsd_write_vector(rqstp, fhp, kiocb->ki_pos,
+						segments[i].iter.count);
+			/*
+			 * Mark the I/O buffer as evict-able to reduce
+			 * memory contention.
+			 */
+			if (nf->nf_file->f_op->fop_flags & FOP_DONTCACHE)
+				kiocb->ki_flags |= IOCB_DONTCACHE;
+		}
+
+		expected = iov_iter_count(&segments[i].iter);
+
+		host_err = vfs_iocb_iter_write(file, kiocb, &segments[i].iter);
+		if (host_err < 0)
+			return host_err;
+		*cnt += host_err;
+		if (host_err < (ssize_t)expected)
+			break;	/* partial write */
+	}
+
+	return 0;
+}
+
+/**
+ * nfsd_vfs_write - write data to an already-open file
+ * @rqstp: RPC execution context
+ * @fhp: File handle of file to write into
+ * @nf: An open file matching @fhp
+ * @offset: Byte offset of start
+ * @payload: xdr_buf containing the write payload
+ * @cnt: IN: number of bytes to write, OUT: number of bytes actually written
+ * @stable: An NFS stable_how value
+ * @verf: NFS WRITE verifier
+ *
+ * Upon return, caller must invoke fh_put on @fhp.
+ *
+ * Return values:
+ *   An nfsstat value in network byte order.
+ */
+__be32
+nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
+	       struct nfsd_file *nf, loff_t offset,
+	       const struct xdr_buf *payload, unsigned long *cnt,
+	       int stable, __be32 *verf)
+{
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct file		*file = nf->nf_file;
+	struct super_block	*sb = file_inode(file)->i_sb;
+	struct kiocb		kiocb;
+	struct svc_export	*exp;
+	struct iov_iter		iter;
+	errseq_t		since;
+	__be32			nfserr;
+	int			host_err;
+	unsigned long		exp_op_flags = 0;
+	unsigned int		pflags = current->flags;
+	bool			restore_flags = false;
+	int			nvecs;
+
+	trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
+
+	if (sb->s_export_op)
+		exp_op_flags = sb->s_export_op->flags;
+
+	if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
+	    !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
+		/*
+		 * We want throttling in balance_dirty_pages()
+		 * and shrink_inactive_list() to only consider
+		 * the backingdev we are writing to, so that nfs to
+		 * localhost doesn't cause nfsd to lock up due to all
+		 * the client's dirty pages or its congested queue.
+		 */
+		current->flags |= PF_LOCAL_THROTTLE;
+		restore_flags = true;
+	}
+
+	exp = fhp->fh_export;
+
+	if (!EX_ISSYNC(exp))
+		stable = NFS_UNSTABLE;
+	init_sync_kiocb(&kiocb, file);
+	kiocb.ki_pos = offset;
+	if (likely(!fhp->fh_use_wgather)) {
+		switch (stable) {
+		case NFS_FILE_SYNC:
+			/* persist data and timestamps */
+			kiocb.ki_flags |= IOCB_DSYNC | IOCB_SYNC;
+			break;
+		case NFS_DATA_SYNC:
+			/* persist data only */
+			kiocb.ki_flags |= IOCB_DSYNC;
+			break;
+		}
+	}
+
+	nvecs = xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, payload);
+	if (nvecs < 0) {
+		host_err = nvecs;
+		goto out_nfserr;
+	}
+
+	since = READ_ONCE(file->f_wb_err);
+	if (verf)
+		nfsd_copy_write_verifier(verf, nn);
+
+	switch (nfsd_io_cache_write) {
+	case NFSD_IO_DIRECT:
+		host_err = nfsd_direct_write(rqstp, fhp, nf, nvecs,
+					     cnt, &kiocb);
+		break;
+	case NFSD_IO_DONTCACHE:
+		if (file->f_op->fop_flags & FOP_DONTCACHE)
+			kiocb.ki_flags |= IOCB_DONTCACHE;
+		fallthrough;
+	case NFSD_IO_BUFFERED:
+		iov_iter_bvec(&iter, ITER_SOURCE, rqstp->rq_bvec, nvecs, *cnt);
+		host_err = vfs_iocb_iter_write(file, &kiocb, &iter);
+		if (host_err < 0)
+			break;
+		*cnt = host_err;
+		break;
+	}
+	if (host_err < 0) {
+		commit_reset_write_verifier(nn, rqstp, host_err);
+		goto out_nfserr;
+	}
+	nfsd_stats_io_write_add(nn, exp, *cnt);
+	fsnotify_modify(file);
+	host_err = filemap_check_wb_err(file->f_mapping, since);
+	if (host_err < 0) {
+		commit_reset_write_verifier(nn, rqstp, host_err);
+		goto out_nfserr;
+	}
+
+	if (stable && fhp->fh_use_wgather) {
+		host_err = wait_for_concurrent_writes(file);
+		if (host_err < 0)
+			commit_reset_write_verifier(nn, rqstp, host_err);
+	}
+
+out_nfserr:
+	if (host_err >= 0) {
+		trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
+		nfserr = nfs_ok;
+	} else {
+		trace_nfsd_write_err(rqstp, fhp, offset, host_err);
+		nfserr = nfserrno(host_err);
+	}
+	if (restore_flags)
+		current_restore_flags(pflags, PF_LOCAL_THROTTLE);
+	return nfserr;
+}
+
+/**
+ * nfsd_read_splice_ok - check if spliced reading is supported
+ * @rqstp: RPC transaction context
+ *
+ * Return values:
+ *   %true: nfsd_splice_read() may be used
+ *   %false: nfsd_splice_read() must not be used
+ *
+ * NFS READ normally uses splice to send data in-place. However the
+ * data in cache can change after the reply's MIC is computed but
+ * before the RPC reply is sent. To prevent the client from
+ * rejecting the server-computed MIC in this somewhat rare case, do
+ * not use splice with the GSS integrity and privacy services.
+ */
+bool nfsd_read_splice_ok(struct svc_rqst *rqstp)
+{
+	if (nfsd_disable_splice_read)
+		return false;
+	switch (svc_auth_flavor(rqstp)) {
+	case RPC_AUTH_GSS_KRB5I:
+	case RPC_AUTH_GSS_KRB5P:
+		return false;
+	}
+	return true;
+}
+
+/**
+ * nfsd_read - Read data from a file
+ * @rqstp: RPC transaction context
+ * @fhp: file handle of file to be read
+ * @offset: starting byte offset
+ * @count: IN: requested number of bytes; OUT: number of bytes read
+ * @eof: OUT: set non-zero if operation reached the end of the file
+ *
+ * The caller must verify that there is enough space in @rqstp.rq_res
+ * to perform this operation.
+ *
+ * N.B. After this call fhp needs an fh_put
+ *
+ * Returns nfs_ok on success, otherwise an nfserr stat value is
+ * returned.
+ */
+__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		 loff_t offset, unsigned long *count, u32 *eof)
+{
+	struct nfsd_file	*nf;
+	struct file *file;
+	__be32 err;
+
+	trace_nfsd_read_start(rqstp, fhp, offset, *count);
+	err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_READ, &nf);
+	if (err)
+		return err;
+
+	file = nf->nf_file;
+	if (file->f_op->splice_read && nfsd_read_splice_ok(rqstp))
+		err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
+	else
+		err = nfsd_iter_read(rqstp, fhp, nf, offset, count, 0, eof);
+
+	nfsd_file_put(nf);
+	trace_nfsd_read_done(rqstp, fhp, offset, *count);
+	return err;
+}
+
+/**
+ * nfsd_write - open a file and write data to it
+ * @rqstp: RPC execution context
+ * @fhp: File handle of file to write into; nfsd_write() may modify it
+ * @offset: Byte offset of start
+ * @payload: xdr_buf containing the write payload
+ * @cnt: IN: number of bytes to write, OUT: number of bytes actually written
+ * @stable: An NFS stable_how value
+ * @verf: NFS WRITE verifier
+ *
+ * Upon return, caller must invoke fh_put on @fhp.
+ *
+ * Return values:
+ *   An nfsstat value in network byte order.
+ */
+__be32
+nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
+	   const struct xdr_buf *payload, unsigned long *cnt, int stable,
+	   __be32 *verf)
+{
+	struct nfsd_file *nf;
+	__be32 err;
+
+	trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
+
+	err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE, &nf);
+	if (err)
+		goto out;
+
+	err = nfsd_vfs_write(rqstp, fhp, nf, offset, payload, cnt,
+			     stable, verf);
+	nfsd_file_put(nf);
+out:
+	trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
+	return err;
+}
+
+/**
+ * nfsd_commit - Commit pending writes to stable storage
+ * @rqstp: RPC request being processed
+ * @fhp: NFS filehandle
+ * @nf: target file
+ * @offset: raw offset from beginning of file
+ * @count: raw count of bytes to sync
+ * @verf: filled in with the server's current write verifier
+ *
+ * Note: we guarantee that data that lies within the range specified
+ * by the 'offset' and 'count' parameters will be synced. The server
+ * is permitted to sync data that lies outside this range at the
+ * same time.
+ *
+ * Unfortunately we cannot lock the file to make sure we return full WCC
+ * data to the client, as locking happens lower down in the filesystem.
+ *
+ * Return values:
+ *   An nfsstat value in network byte order.
+ */
+__be32
+nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
+	    u64 offset, u32 count, __be32 *verf)
+{
+	__be32			err = nfs_ok;
+	u64			maxbytes;
+	loff_t			start, end;
+	struct nfsd_net		*nn;
+
+	trace_nfsd_commit_start(rqstp, fhp, offset, count);
+
+	/*
+	 * Convert the client-provided (offset, count) range to a
+	 * (start, end) range. If the client-provided range falls
+	 * outside the maximum file size of the underlying FS,
+	 * clamp the sync range appropriately.
+	 */
+	start = 0;
+	end = LLONG_MAX;
+	maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
+	if (offset < maxbytes) {
+		start = offset;
+		if (count && (offset + count - 1 < maxbytes))
+			end = offset + count - 1;
+	}
+
+	nn = net_generic(nf->nf_net, nfsd_net_id);
+	if (EX_ISSYNC(fhp->fh_export)) {
+		errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
+		int err2;
+
+		err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
+		switch (err2) {
+		case 0:
+			nfsd_copy_write_verifier(verf, nn);
+			err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
+						    since);
+			if (err2 < 0)
+				commit_reset_write_verifier(nn, rqstp, err2);
+			err = nfserrno(err2);
+			break;
+		case -EINVAL:
+			err = nfserr_notsupp;
+			break;
+		default:
+			commit_reset_write_verifier(nn, rqstp, err2);
+			err = nfserrno(err2);
+		}
+	} else
+		nfsd_copy_write_verifier(verf, nn);
+
+	trace_nfsd_commit_done(rqstp, fhp, offset, count);
+	return err;
+}
+
+/**
+ * nfsd_create_setattr - Set a created file's attributes
+ * @rqstp: RPC transaction being executed
+ * @fhp: NFS filehandle of parent directory
+ * @resfhp: NFS filehandle of new object
+ * @attrs: requested attributes of new object
+ *
+ * Returns nfs_ok on success, or an nfsstat in network byte order.
+ */
+__be32
+nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		    struct svc_fh *resfhp, struct nfsd_attrs *attrs)
+{
+	struct iattr *iap = attrs->na_iattr;
+	__be32 status;
+
+	/*
+	 * Mode has already been set by file creation.
+	 */
+	iap->ia_valid &= ~ATTR_MODE;
+
+	/*
+	 * Setting uid/gid works only for root.  Irix appears to
+	 * send along the gid on create when it tries to implement
+	 * setgid directories via NFS:
+	 */
+	if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
+		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
+
+	/*
+	 * Callers expect new file metadata to be committed even
+	 * if the attributes have not changed.
+	 */
+	if (nfsd_attrs_valid(attrs))
+		status = nfsd_setattr(rqstp, resfhp, attrs, NULL);
+	else
+		status = nfserrno(commit_metadata(resfhp));
+
+	/*
+	 * Transactional filesystems had a chance to commit changes
+	 * for both parent and child simultaneously making the
+	 * following commit_metadata a noop in many cases.
+	 */
+	if (!status)
+		status = nfserrno(commit_metadata(fhp));
+
+	/*
+	 * Update the new filehandle to pick up the new attributes.
+	 */
+	if (!status)
+		status = fh_update(resfhp);
+
+	return status;
+}
+
+/* HPUX client sometimes creates a file in mode 000, and sets size to 0.
+ * setting size to 0 may fail for some specific file systems by the permission
+ * checking which requires WRITE permission but the mode is 000.
+ * we ignore the resizing(to 0) on the just new created file, since the size is
+ * 0 after file created.
+ *
+ * call this only after vfs_create() is called.
+ * */
+static void
+nfsd_check_ignore_resizing(struct iattr *iap)
+{
+	if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+		iap->ia_valid &= ~ATTR_SIZE;
+}
+
+/* The parent directory should already be locked - we will unlock */
+__be32
+nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		   struct nfsd_attrs *attrs,
+		   int type, dev_t rdev, struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dchild;
+	struct inode	*dirp;
+	struct iattr	*iap = attrs->na_iattr;
+	__be32		err;
+	int		host_err = 0;
+
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	dchild = dget(resfhp->fh_dentry);
+	err = nfsd_permission(&rqstp->rq_cred, fhp->fh_export, dentry,
+			      NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	if (!(iap->ia_valid & ATTR_MODE))
+		iap->ia_mode = 0;
+	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
+
+	if (!IS_POSIXACL(dirp))
+		iap->ia_mode &= ~current_umask();
+
+	err = 0;
+	switch (type) {
+	case S_IFREG:
+		host_err = vfs_create(&nop_mnt_idmap, dchild, iap->ia_mode, NULL);
+		if (!host_err)
+			nfsd_check_ignore_resizing(iap);
+		break;
+	case S_IFDIR:
+		dchild = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode, NULL);
+		if (IS_ERR(dchild)) {
+			host_err = PTR_ERR(dchild);
+		} else if (d_is_negative(dchild)) {
+			err = nfserr_serverfault;
+			goto out;
+		} else if (unlikely(dchild != resfhp->fh_dentry)) {
+			dput(resfhp->fh_dentry);
+			resfhp->fh_dentry = dget(dchild);
+		}
+		break;
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFIFO:
+	case S_IFSOCK:
+		host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild,
+				     iap->ia_mode, rdev, NULL);
+		break;
+	default:
+		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
+		       type);
+		host_err = -EINVAL;
+	}
+	if (host_err < 0)
+		goto out_nfserr;
+
+	err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
+
+out:
+	if (!err)
+		fh_fill_post_attrs(fhp);
+	end_creating(dchild);
+	return err;
+
+out_nfserr:
+	err = nfserrno(host_err);
+	goto out;
+}
+
+/*
+ * Create a filesystem object (regular, directory, special).
+ * Note that the parent directory is left locked.
+ *
+ * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
+ */
+__be32
+nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+	    char *fname, int flen, struct nfsd_attrs *attrs,
+	    int type, dev_t rdev, struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dchild = NULL;
+	__be32		err;
+	int		host_err;
+
+	trace_nfsd_vfs_create(rqstp, fhp, type, fname, flen);
+
+	if (name_is_dot_dotdot(fname, flen))
+		return nfserr_exist;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
+	if (err)
+		return err;
+
+	dentry = fhp->fh_dentry;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		return nfserrno(host_err);
+
+	dchild = start_creating(&nop_mnt_idmap, dentry, &QSTR_LEN(fname, flen));
+	host_err = PTR_ERR(dchild);
+	if (IS_ERR(dchild))
+		return nfserrno(host_err);
+
+	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+	if (err)
+		goto out_unlock;
+	err = fh_fill_pre_attrs(fhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp);
+	/* nfsd_create_locked() unlocked the parent */
+	dput(dchild);
+	return err;
+
+out_unlock:
+	end_creating(dchild);
+	return err;
+}
+
+/*
+ * Read a symlink. On entry, *lenp must contain the maximum path length that
+ * fits into the buffer. On return, it contains the true length.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
+{
+	__be32		err;
+	const char *link;
+	struct path path;
+	DEFINE_DELAYED_CALL(done);
+	int len;
+
+	err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
+	if (unlikely(err))
+		return err;
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+
+	if (unlikely(!d_is_symlink(path.dentry)))
+		return nfserr_inval;
+
+	touch_atime(&path);
+
+	link = vfs_get_link(path.dentry, &done);
+	if (IS_ERR(link))
+		return nfserrno(PTR_ERR(link));
+
+	len = strlen(link);
+	if (len < *lenp)
+		*lenp = len;
+	memcpy(buf, link, *lenp);
+	do_delayed_call(&done);
+	return 0;
+}
+
+/**
+ * nfsd_symlink - Create a symlink and look up its inode
+ * @rqstp: RPC transaction being executed
+ * @fhp: NFS filehandle of parent directory
+ * @fname: filename of the new symlink
+ * @flen: length of @fname
+ * @path: content of the new symlink (NUL-terminated)
+ * @attrs: requested attributes of new object
+ * @resfhp: NFS filehandle of new object
+ *
+ * N.B. After this call _both_ fhp and resfhp need an fh_put
+ *
+ * Returns nfs_ok on success, or an nfsstat in network byte order.
+ */
+__be32
+nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
+	     char *fname, int flen,
+	     char *path, struct nfsd_attrs *attrs,
+	     struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dnew;
+	__be32		err, cerr;
+	int		host_err;
+
+	trace_nfsd_vfs_symlink(rqstp, fhp, fname, flen, path);
+
+	err = nfserr_noent;
+	if (!flen || path[0] == '\0')
+		goto out;
+	err = nfserr_exist;
+	if (name_is_dot_dotdot(fname, flen))
+		goto out;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	host_err = fh_want_write(fhp);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out;
+	}
+
+	dentry = fhp->fh_dentry;
+	dnew = start_creating(&nop_mnt_idmap, dentry, &QSTR_LEN(fname, flen));
+	if (IS_ERR(dnew)) {
+		err = nfserrno(PTR_ERR(dnew));
+		goto out_drop_write;
+	}
+	err = fh_fill_pre_attrs(fhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path, NULL);
+	err = nfserrno(host_err);
+	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
+	if (!err)
+		nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
+	fh_fill_post_attrs(fhp);
+out_unlock:
+	end_creating(dnew);
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+	if (!err)
+		err = cerr;
+out_drop_write:
+	fh_drop_write(fhp);
+out:
+	return err;
+}
+
+/**
+ * nfsd_link - create a link
+ * @rqstp: RPC transaction context
+ * @ffhp: the file handle of the directory where the new link is to be created
+ * @name: the filename of the new link
+ * @len: the length of @name in octets
+ * @tfhp: the file handle of an existing file object
+ *
+ * After this call _both_ ffhp and tfhp need an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
+ */
+__be32
+nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
+				char *name, int len, struct svc_fh *tfhp)
+{
+	struct dentry	*ddir, *dnew, *dold;
+	struct inode	*dirp;
+	int		type;
+	__be32		err;
+	int		host_err;
+
+	trace_nfsd_vfs_link(rqstp, ffhp, tfhp, name, len);
+
+	err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
+	if (err)
+		goto out;
+	err = nfserr_isdir;
+	if (d_is_dir(tfhp->fh_dentry))
+		goto out;
+	err = nfserr_perm;
+	if (!len)
+		goto out;
+	err = nfserr_exist;
+	if (name_is_dot_dotdot(name, len))
+		goto out;
+
+	err = nfs_ok;
+	type = d_inode(tfhp->fh_dentry)->i_mode & S_IFMT;
+	host_err = fh_want_write(tfhp);
+	if (host_err)
+		goto out;
+
+	ddir = ffhp->fh_dentry;
+	dirp = d_inode(ddir);
+	dnew = start_creating(&nop_mnt_idmap, ddir, &QSTR_LEN(name, len));
+
+	if (IS_ERR(dnew)) {
+		host_err = PTR_ERR(dnew);
+		goto out_drop_write;
+	}
+
+	dold = tfhp->fh_dentry;
+
+	err = nfserr_noent;
+	if (d_really_is_negative(dold))
+		goto out_unlock;
+	err = fh_fill_pre_attrs(ffhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	host_err = vfs_link(dold, &nop_mnt_idmap, dirp, dnew, NULL);
+	fh_fill_post_attrs(ffhp);
+out_unlock:
+	end_creating(dnew);
+	if (!host_err) {
+		host_err = commit_metadata(ffhp);
+		if (!host_err)
+			host_err = commit_metadata(tfhp);
+	}
+
+out_drop_write:
+	fh_drop_write(tfhp);
+	if (host_err == -EBUSY) {
+		/*
+		 * See RFC 8881 Section 18.9.4 para 1-2: NFSv4 LINK
+		 * wants a status unique to the object type.
+		 */
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	}
+out:
+	return err != nfs_ok ? err : nfserrno(host_err);
+}
+
+static void
+nfsd_close_cached_files(struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (inode && S_ISREG(inode->i_mode))
+		nfsd_file_close_inode_sync(inode);
+}
+
+static bool
+nfsd_has_cached_files(struct dentry *dentry)
+{
+	bool		ret = false;
+	struct inode *inode = d_inode(dentry);
+
+	if (inode && S_ISREG(inode->i_mode))
+		ret = nfsd_file_is_cached(inode);
+	return ret;
+}
+
+/**
+ * nfsd_rename - rename a directory entry
+ * @rqstp: RPC transaction context
+ * @ffhp: the file handle of parent directory containing the entry to be renamed
+ * @fname: the filename of directory entry to be renamed
+ * @flen: the length of @fname in octets
+ * @tfhp: the file handle of parent directory to contain the renamed entry
+ * @tname: the filename of the new entry
+ * @tlen: the length of @tlen in octets
+ *
+ * After this call _both_ ffhp and tfhp need an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
+ */
+__be32
+nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
+			    struct svc_fh *tfhp, char *tname, int tlen)
+{
+	struct dentry	*fdentry, *tdentry;
+	int		type = S_IFDIR;
+	struct renamedata rd = {};
+	__be32		err;
+	int		host_err;
+	struct dentry	*close_cached;
+
+	trace_nfsd_vfs_rename(rqstp, ffhp, tfhp, fname, flen, tname, tlen);
+
+	err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	fdentry = ffhp->fh_dentry;
+
+	tdentry = tfhp->fh_dentry;
+
+	err = nfserr_perm;
+	if (!flen || name_is_dot_dotdot(fname, flen) ||
+	    !tlen || name_is_dot_dotdot(tname, tlen))
+		goto out;
+
+	err = nfserr_xdev;
+	if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+		goto out;
+	if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
+		goto out;
+
+retry:
+	close_cached = NULL;
+	host_err = fh_want_write(ffhp);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out;
+	}
+
+	rd.mnt_idmap	= &nop_mnt_idmap;
+	rd.old_parent	= fdentry;
+	rd.new_parent	= tdentry;
+
+	host_err = start_renaming(&rd, 0, &QSTR_LEN(fname, flen),
+				  &QSTR_LEN(tname, tlen));
+
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out_want_write;
+	}
+	err = fh_fill_pre_attrs(ffhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	err = fh_fill_pre_attrs(tfhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+
+	type = d_inode(rd.old_dentry)->i_mode & S_IFMT;
+
+	if (d_inode(rd.new_dentry))
+		type = d_inode(rd.new_dentry)->i_mode & S_IFMT;
+
+	if ((rd.new_dentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
+	    nfsd_has_cached_files(rd.new_dentry)) {
+		close_cached = dget(rd.new_dentry);
+		goto out_unlock;
+	} else {
+		int retries;
+
+		for (retries = 1;;) {
+			host_err = vfs_rename(&rd);
+			if (host_err != -EAGAIN || !retries--)
+				break;
+			if (!nfsd_wait_for_delegreturn(rqstp, d_inode(rd.old_dentry)))
+				break;
+		}
+		if (!host_err) {
+			host_err = commit_metadata(tfhp);
+			if (!host_err)
+				host_err = commit_metadata(ffhp);
+		}
+	}
+	if (host_err == -EBUSY) {
+		/*
+		 * See RFC 8881 Section 18.26.4 para 1-3: NFSv4 RENAME
+		 * wants a status unique to the object type.
+		 */
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	} else {
+		err = nfserrno(host_err);
+	}
+
+	if (!close_cached) {
+		fh_fill_post_attrs(ffhp);
+		fh_fill_post_attrs(tfhp);
+	}
+out_unlock:
+	end_renaming(&rd);
+out_want_write:
+	fh_drop_write(ffhp);
+
+	/*
+	 * If the target dentry has cached open files, then we need to
+	 * try to close them prior to doing the rename.  Final fput
+	 * shouldn't be done with locks held however, so we delay it
+	 * until this point and then reattempt the whole shebang.
+	 */
+	if (close_cached) {
+		nfsd_close_cached_files(close_cached);
+		dput(close_cached);
+		goto retry;
+	}
+out:
+	return err;
+}
+
+/**
+ * nfsd_unlink - remove a directory entry
+ * @rqstp: RPC transaction context
+ * @fhp: the file handle of the parent directory to be modified
+ * @type: enforced file type of the object to be removed
+ * @fname: the name of directory entry to be removed
+ * @flen: length of @fname in octets
+ *
+ * After this call fhp needs an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
+ */
+__be32
+nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
+				char *fname, int flen)
+{
+	struct dentry	*dentry, *rdentry;
+	struct inode	*dirp;
+	struct inode	*rinode = NULL;
+	__be32		err;
+	int		host_err;
+
+	trace_nfsd_vfs_unlink(rqstp, fhp, fname, flen);
+
+	err = nfserr_acces;
+	if (!flen || name_is_dot_dotdot(fname, flen))
+		goto out;
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
+	if (err)
+		goto out;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	rdentry = start_removing(&nop_mnt_idmap, dentry, &QSTR_LEN(fname, flen));
+
+	host_err = PTR_ERR(rdentry);
+	if (IS_ERR(rdentry))
+		goto out_drop_write;
+
+	err = fh_fill_pre_attrs(fhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+
+	rinode = d_inode(rdentry);
+	/* Prevent truncation until after locks dropped */
+	ihold(rinode);
+
+	if (!type)
+		type = d_inode(rdentry)->i_mode & S_IFMT;
+
+	if (type != S_IFDIR) {
+		int retries;
+
+		if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
+			nfsd_close_cached_files(rdentry);
+
+		for (retries = 1;;) {
+			host_err = vfs_unlink(&nop_mnt_idmap, dirp, rdentry, NULL);
+			if (host_err != -EAGAIN || !retries--)
+				break;
+			if (!nfsd_wait_for_delegreturn(rqstp, rinode))
+				break;
+		}
+	} else {
+		host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry, NULL);
+	}
+	fh_fill_post_attrs(fhp);
+
+out_unlock:
+	end_removing(rdentry);
+	if (!err && !host_err)
+		host_err = commit_metadata(fhp);
+	iput(rinode);    /* truncate the inode here */
+
+out_drop_write:
+	fh_drop_write(fhp);
+out_nfserr:
+	if (host_err == -EBUSY) {
+		/*
+		 * See RFC 8881 Section 18.25.4 para 4: NFSv4 REMOVE
+		 * wants a status unique to the object type.
+		 */
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	}
+out:
+	return err != nfs_ok ? err : nfserrno(host_err);
+}
+
+/*
+ * We do this buffering because we must not call back into the file
+ * system's ->lookup() method from the filldir callback. That may well
+ * deadlock a number of file systems.
+ *
+ * This is based heavily on the implementation of same in XFS.
+ */
+struct buffered_dirent {
+	u64		ino;
+	loff_t		offset;
+	int		namlen;
+	unsigned int	d_type;
+	char		name[];
+};
+
+struct readdir_data {
+	struct dir_context ctx;
+	char		*dirent;
+	size_t		used;
+	int		full;
+};
+
+static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
+				 int namlen, loff_t offset, u64 ino,
+				 unsigned int d_type)
+{
+	struct readdir_data *buf =
+		container_of(ctx, struct readdir_data, ctx);
+	struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
+	unsigned int reclen;
+
+	reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
+	if (buf->used + reclen > PAGE_SIZE) {
+		buf->full = 1;
+		return false;
+	}
+
+	de->namlen = namlen;
+	de->offset = offset;
+	de->ino = ino;
+	de->d_type = d_type;
+	memcpy(de->name, name, namlen);
+	buf->used += reclen;
+
+	return true;
+}
+
+static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
+				    nfsd_filldir_t func, struct readdir_cd *cdp,
+				    loff_t *offsetp)
+{
+	struct buffered_dirent *de;
+	int host_err;
+	int size;
+	loff_t offset;
+	struct readdir_data buf = {
+		.ctx.actor = nfsd_buffered_filldir,
+		.dirent = kmalloc(PAGE_SIZE, GFP_KERNEL)
+	};
+
+	if (!buf.dirent)
+		return nfserrno(-ENOMEM);
+
+	offset = *offsetp;
+
+	while (1) {
+		unsigned int reclen;
+
+		cdp->err = nfserr_eof; /* will be cleared on successful read */
+		buf.used = 0;
+		buf.full = 0;
+
+		host_err = iterate_dir(file, &buf.ctx);
+		if (buf.full)
+			host_err = 0;
+
+		if (host_err < 0)
+			break;
+
+		size = buf.used;
+
+		if (!size)
+			break;
+
+		de = (struct buffered_dirent *)buf.dirent;
+		while (size > 0) {
+			offset = de->offset;
+
+			if (func(cdp, de->name, de->namlen, de->offset,
+				 de->ino, de->d_type))
+				break;
+
+			if (cdp->err != nfs_ok)
+				break;
+
+			trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
+
+			reclen = ALIGN(sizeof(*de) + de->namlen,
+				       sizeof(u64));
+			size -= reclen;
+			de = (struct buffered_dirent *)((char *)de + reclen);
+		}
+		if (size > 0) /* We bailed out early */
+			break;
+
+		offset = vfs_llseek(file, 0, SEEK_CUR);
+	}
+
+	kfree((buf.dirent));
+
+	if (host_err)
+		return nfserrno(host_err);
+
+	*offsetp = offset;
+	return cdp->err;
+}
+
+/**
+ * nfsd_readdir - Read entries from a directory
+ * @rqstp: RPC transaction context
+ * @fhp: NFS file handle of directory to be read
+ * @offsetp: OUT: seek offset of final entry that was read
+ * @cdp: OUT: an eof error value
+ * @func: entry filler actor
+ *
+ * This implementation ignores the NFSv3/4 verifier cookie.
+ *
+ * NB: normal system calls hold file->f_pos_lock when calling
+ * ->iterate_shared and ->llseek, but nfsd_readdir() does not.
+ * Because the struct file acquired here is not visible to other
+ * threads, it's internal state does not need mutex protection.
+ *
+ * Returns nfs_ok on success, otherwise an nfsstat code is
+ * returned.
+ */
+__be32
+nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
+	     struct readdir_cd *cdp, nfsd_filldir_t func)
+{
+	__be32		err;
+	struct file	*file;
+	loff_t		offset = *offsetp;
+	int             may_flags = NFSD_MAY_READ;
+
+	err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
+	if (err)
+		goto out;
+
+	if (fhp->fh_64bit_cookies)
+		file->f_mode |= FMODE_64BITHASH;
+	else
+		file->f_mode |= FMODE_32BITHASH;
+
+	offset = vfs_llseek(file, offset, SEEK_SET);
+	if (offset < 0) {
+		err = nfserrno((int)offset);
+		goto out_close;
+	}
+
+	err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
+
+	if (err == nfserr_eof || err == nfserr_toosmall)
+		err = nfs_ok; /* can still be found in ->err */
+out_close:
+	nfsd_filp_close(file);
+out:
+	return err;
+}
+
+/**
+ * nfsd_filp_close: close a file synchronously
+ * @fp: the file to close
+ *
+ * nfsd_filp_close() is similar in behaviour to filp_close().
+ * The difference is that if this is the final close on the
+ * file, the that finalisation happens immediately, rather then
+ * being handed over to a work_queue, as it the case for
+ * filp_close().
+ * When a user-space process closes a file (even when using
+ * filp_close() the finalisation happens before returning to
+ * userspace, so it is effectively synchronous.  When a kernel thread
+ * uses file_close(), on the other hand, the handling is completely
+ * asynchronous.  This means that any cost imposed by that finalisation
+ * is not imposed on the nfsd thread, and nfsd could potentually
+ * close files more quickly than the work queue finalises the close,
+ * which would lead to unbounded growth in the queue.
+ *
+ * In some contexts is it not safe to synchronously wait for
+ * close finalisation (see comment for __fput_sync()), but nfsd
+ * does not match those contexts.  In partcilarly it does not, at the
+ * time that this function is called, hold and locks and no finalisation
+ * of any file, socket, or device driver would have any cause to wait
+ * for nfsd to make progress.
+ */
+void nfsd_filp_close(struct file *fp)
+{
+	get_file(fp);
+	filp_close(fp, NULL);
+	__fput_sync(fp);
+}
+
+/*
+ * Get file system stats
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
+{
+	__be32 err;
+
+	trace_nfsd_vfs_statfs(rqstp, fhp);
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
+	if (!err) {
+		struct path path = {
+			.mnt	= fhp->fh_export->ex_path.mnt,
+			.dentry	= fhp->fh_dentry,
+		};
+		if (vfs_statfs(&path, stat))
+			err = nfserr_io;
+	}
+	return err;
+}
+
+static int exp_rdonly(struct svc_cred *cred, struct svc_export *exp)
+{
+	return nfsexp_flags(cred, exp) & NFSEXP_READONLY;
+}
+
+#ifdef CONFIG_NFSD_V4
+/*
+ * Helper function to translate error numbers. In the case of xattr operations,
+ * some error codes need to be translated outside of the standard translations.
+ *
+ * ENODATA needs to be translated to nfserr_noxattr.
+ * E2BIG to nfserr_xattr2big.
+ *
+ * Additionally, vfs_listxattr can return -ERANGE. This means that the
+ * file has too many extended attributes to retrieve inside an
+ * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
+ * filesystems will allow the adding of extended attributes until they hit
+ * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
+ * So, at that point, the attributes are present and valid, but can't
+ * be retrieved using listxattr, since the upper level xattr code enforces
+ * the XATTR_LIST_MAX limit.
+ *
+ * This bug means that we need to deal with listxattr returning -ERANGE. The
+ * best mapping is to return TOOSMALL.
+ */
+static __be32
+nfsd_xattr_errno(int err)
+{
+	switch (err) {
+	case -ENODATA:
+		return nfserr_noxattr;
+	case -E2BIG:
+		return nfserr_xattr2big;
+	case -ERANGE:
+		return nfserr_toosmall;
+	}
+	return nfserrno(err);
+}
+
+/*
+ * Retrieve the specified user extended attribute. To avoid always
+ * having to allocate the maximum size (since we are not getting
+ * a maximum size from the RPC), do a probe + alloc. Hold a reader
+ * lock on i_rwsem to prevent the extended attribute from changing
+ * size while we're doing this.
+ */
+__be32
+nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
+	      void **bufp, int *lenp)
+{
+	ssize_t len;
+	__be32 err;
+	char *buf;
+	struct inode *inode;
+	struct dentry *dentry;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
+	if (err)
+		return err;
+
+	err = nfs_ok;
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+
+	inode_lock_shared(inode);
+
+	len = vfs_getxattr(&nop_mnt_idmap, dentry, name, NULL, 0);
+
+	/*
+	 * Zero-length attribute, just return.
+	 */
+	if (len == 0) {
+		*bufp = NULL;
+		*lenp = 0;
+		goto out;
+	}
+
+	if (len < 0) {
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	if (len > *lenp) {
+		err = nfserr_toosmall;
+		goto out;
+	}
+
+	buf = kvmalloc(len, GFP_KERNEL);
+	if (buf == NULL) {
+		err = nfserr_jukebox;
+		goto out;
+	}
+
+	len = vfs_getxattr(&nop_mnt_idmap, dentry, name, buf, len);
+	if (len <= 0) {
+		kvfree(buf);
+		buf = NULL;
+		err = nfsd_xattr_errno(len);
+	}
+
+	*lenp = len;
+	*bufp = buf;
+
+out:
+	inode_unlock_shared(inode);
+
+	return err;
+}
+
+/*
+ * Retrieve the xattr names. Since we can't know how many are
+ * user extended attributes, we must get all attributes here,
+ * and have the XDR encode filter out the "user." ones.
+ *
+ * While this could always just allocate an XATTR_LIST_MAX
+ * buffer, that's a waste, so do a probe + allocate. To
+ * avoid any changes between the probe and allocate, wrap
+ * this in inode_lock.
+ */
+__be32
+nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
+	       int *lenp)
+{
+	ssize_t len;
+	__be32 err;
+	char *buf;
+	struct inode *inode;
+	struct dentry *dentry;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
+	if (err)
+		return err;
+
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+	*lenp = 0;
+
+	inode_lock_shared(inode);
+
+	len = vfs_listxattr(dentry, NULL, 0);
+	if (len <= 0) {
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	if (len > XATTR_LIST_MAX) {
+		err = nfserr_xattr2big;
+		goto out;
+	}
+
+	buf = kvmalloc(len, GFP_KERNEL);
+	if (buf == NULL) {
+		err = nfserr_jukebox;
+		goto out;
+	}
+
+	len = vfs_listxattr(dentry, buf, len);
+	if (len <= 0) {
+		kvfree(buf);
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	*lenp = len;
+	*bufp = buf;
+
+	err = nfs_ok;
+out:
+	inode_unlock_shared(inode);
+
+	return err;
+}
+
+/**
+ * nfsd_removexattr - Remove an extended attribute
+ * @rqstp: RPC transaction being executed
+ * @fhp: NFS filehandle of object with xattr to remove
+ * @name: name of xattr to remove (NUL-terminate)
+ *
+ * Pass in a NULL pointer for delegated_inode, and let the client deal
+ * with NFS4ERR_DELAY (same as with e.g. setattr and remove).
+ *
+ * Returns nfs_ok on success, or an nfsstat in network byte order.
+ */
+__be32
+nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
+{
+	__be32 err;
+	int ret;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
+	if (err)
+		return err;
+
+	ret = fh_want_write(fhp);
+	if (ret)
+		return nfserrno(ret);
+
+	inode_lock(fhp->fh_dentry->d_inode);
+	err = fh_fill_pre_attrs(fhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	ret = __vfs_removexattr_locked(&nop_mnt_idmap, fhp->fh_dentry,
+				       name, NULL);
+	err = nfsd_xattr_errno(ret);
+	fh_fill_post_attrs(fhp);
+out_unlock:
+	inode_unlock(fhp->fh_dentry->d_inode);
+	fh_drop_write(fhp);
+
+	return err;
+}
+
+__be32
+nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
+	      void *buf, u32 len, u32 flags)
+{
+	__be32 err;
+	int ret;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
+	if (err)
+		return err;
+
+	ret = fh_want_write(fhp);
+	if (ret)
+		return nfserrno(ret);
+	inode_lock(fhp->fh_dentry->d_inode);
+	err = fh_fill_pre_attrs(fhp);
+	if (err != nfs_ok)
+		goto out_unlock;
+	ret = __vfs_setxattr_locked(&nop_mnt_idmap, fhp->fh_dentry,
+				    name, buf, len, flags, NULL);
+	fh_fill_post_attrs(fhp);
+	err = nfsd_xattr_errno(ret);
+out_unlock:
+	inode_unlock(fhp->fh_dentry->d_inode);
+	fh_drop_write(fhp);
+	return err;
+}
+#endif
+
+/*
+ * Check for a user's access permissions to this inode.
+ */
+__be32
+nfsd_permission(struct svc_cred *cred, struct svc_export *exp,
+		struct dentry *dentry, int acc)
+{
+	struct inode	*inode = d_inode(dentry);
+	int		err;
+
+	if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
+		return 0;
+#if 0
+	dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
+		acc,
+		(acc & NFSD_MAY_READ)?	" read"  : "",
+		(acc & NFSD_MAY_WRITE)?	" write" : "",
+		(acc & NFSD_MAY_EXEC)?	" exec"  : "",
+		(acc & NFSD_MAY_SATTR)?	" sattr" : "",
+		(acc & NFSD_MAY_TRUNC)?	" trunc" : "",
+		(acc & NFSD_MAY_NLM)?	" nlm"  : "",
+		(acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
+		inode->i_mode,
+		IS_IMMUTABLE(inode)?	" immut" : "",
+		IS_APPEND(inode)?	" append" : "",
+		__mnt_is_readonly(exp->ex_path.mnt)?	" ro" : "");
+	dprintk("      owner %d/%d user %d/%d\n",
+		inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
+#endif
+
+	/* Normally we reject any write/sattr etc access on a read-only file
+	 * system.  But if it is IRIX doing check on write-access for a 
+	 * device special file, we ignore rofs.
+	 */
+	if (!(acc & NFSD_MAY_LOCAL_ACCESS))
+		if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
+			if (exp_rdonly(cred, exp) ||
+			    __mnt_is_readonly(exp->ex_path.mnt))
+				return nfserr_rofs;
+			if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
+				return nfserr_perm;
+		}
+	if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
+		return nfserr_perm;
+
+	/*
+	 * The file owner always gets access permission for accesses that
+	 * would normally be checked at open time. This is to make
+	 * file access work even when the client has done a fchmod(fd, 0).
+	 *
+	 * However, `cp foo bar' should fail nevertheless when bar is
+	 * readonly. A sensible way to do this might be to reject all
+	 * attempts to truncate a read-only file, because a creat() call
+	 * always implies file truncation.
+	 * ... but this isn't really fair.  A process may reasonably call
+	 * ftruncate on an open file descriptor on a file with perm 000.
+	 * We must trust the client to do permission checking - using "ACCESS"
+	 * with NFSv3.
+	 */
+	if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
+	    uid_eq(inode->i_uid, current_fsuid()))
+		return 0;
+
+	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
+	err = inode_permission(&nop_mnt_idmap, inode,
+			       acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
+
+	/* Allow read access to binaries even when mode 111 */
+	if (err == -EACCES && S_ISREG(inode->i_mode) &&
+	     (((acc & NFSD_MAY_MASK) == NFSD_MAY_READ) &&
+	      (acc & (NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_READ_IF_EXEC))))
+		err = inode_permission(&nop_mnt_idmap, inode, MAY_EXEC);
+
+	return err? nfserrno(err) : 0;
+}
+
+/**
+ * nfsd_get_case_info - get case sensitivity info for a dentry
+ * @dentry: dentry to query
+ * @case_insensitive: set to true if name comparison ignores case
+ * @case_preserving: set to true if case is preserved on disk
+ *
+ * On casefold-capable filesystems the flag lives on the directory,
+ * not on its entries, so for a non-directory @dentry the parent is
+ * queried instead. A directory (including an export root, whose
+ * parent lies outside the export) is queried as-is so its own
+ * contents' lookup behavior is reported. NFSD advertises
+ * fattr4_homogeneous as FALSE, so per-directory answers may differ
+ * within an export.
+ *
+ * The probe runs with kernel credentials. case_insensitive and
+ * case_preserving describe the directory's structural lookup
+ * behavior, not the caller's identity; running under the calling
+ * client's mapped credentials would let per-client MAC policy on
+ * the parent directory turn this query into NFS4ERR_ACCESS even
+ * though the underlying property is the same for every client.
+ *
+ * When the filesystem does not expose case-folding state (no
+ * ->fileattr_get, or the callback returns -EOPNOTSUPP /
+ * -ENOIOCTLCMD / -ENOTTY / -EINVAL), the outputs are filled with
+ * POSIX defaults (case-sensitive, case-preserving) on the premise
+ * that a filesystem with case-folding support wires up
+ * fileattr_get.
+ *
+ * Return: 0 with outputs filled, -EOPNOTSUPP with outputs filled
+ *         to POSIX defaults, or a negative errno (e.g., -EIO,
+ *         -ESTALE, -ENOMEM) with outputs unmodified.
+ */
+int
+nfsd_get_case_info(struct dentry *dentry, bool *case_insensitive,
+		   bool *case_preserving)
+{
+	struct file_kattr fa = {};
+	const struct cred *saved;
+	struct cred *probe;
+	struct dentry *cd;
+	bool put = false;
+	int err;
+
+	if (d_is_dir(dentry)) {
+		cd = dentry;
+	} else {
+		cd = dget_parent(dentry);
+		put = true;
+	}
+
+	probe = prepare_kernel_cred(&init_task);
+	if (!probe) {
+		err = -ENOMEM;
+		goto out;
+	}
+	saved = override_creds(probe);
+
+	err = vfs_fileattr_get(cd, &fa);
+
+	put_cred(revert_creds(saved));
+out:
+	if (put)
+		dput(cd);
+	switch (err) {
+	case 0:
+		*case_insensitive = fa.fsx_xflags & FS_XFLAG_CASEFOLD;
+		*case_preserving =
+			!(fa.fsx_xflags & FS_XFLAG_CASENONPRESERVING);
+		return 0;
+	case -EINVAL:
+	case -ENOTTY:
+	case -ENOIOCTLCMD:
+	case -EOPNOTSUPP:
+		/*
+		 * Filesystem does not expose case state.
+		 * Report POSIX defaults.
+		 */
+		*case_insensitive = false;
+		*case_preserving = true;
+		return -EOPNOTSUPP;
+	default:
+		return err;
+	}
+}
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
new file mode 100644
index 000000000..4af2ff9e9
--- /dev/null
+++ b/fs/nfsd/vfs.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_VFS_H
+#define LINUX_NFSD_VFS_H
+
+#include <linux/fs.h>
+#include <linux/posix_acl.h>
+#include "nfsfh.h"
+
+/*
+ * Flags for nfsd_permission
+ */
+#define NFSD_MAY_NOP			0
+#define NFSD_MAY_EXEC			0x001 /* == MAY_EXEC */
+#define NFSD_MAY_WRITE			0x002 /* == MAY_WRITE */
+#define NFSD_MAY_READ			0x004 /* == MAY_READ */
+#define NFSD_MAY_SATTR			0x008
+#define NFSD_MAY_TRUNC			0x010
+#define NFSD_MAY_NLM			0x020 /* request is from lockd */
+#define NFSD_MAY_MASK			0x03f
+
+/* extra hints to permission and open routines: */
+#define NFSD_MAY_OWNER_OVERRIDE		0x040
+#define NFSD_MAY_LOCAL_ACCESS		0x080 /* for device special files */
+#define NFSD_MAY_BYPASS_GSS_ON_ROOT	0x100
+#define NFSD_MAY_NOT_BREAK_LEASE	0x200
+#define NFSD_MAY_BYPASS_GSS		0x400
+#define NFSD_MAY_READ_IF_EXEC		0x800
+
+#define NFSD_MAY_64BIT_COOKIE		0x1000 /* 64 bit readdir cookies for >= NFSv3 */
+
+#define NFSD_MAY_LOCALIO		0x2000 /* for tracing, reflects when localio used */
+
+#define NFSD_MAY_CREATE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE)
+#define NFSD_MAY_REMOVE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
+
+struct nfsd_file;
+
+/*
+ * Callback function for readdir
+ */
+typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
+
+struct readdir_cd {
+	__be32			err;	/* nfs_ok, nfserr, or nfserr_eof */
+};
+
+/* nfsd/vfs.c */
+struct nfsd_attrs {
+	struct iattr		*na_iattr;	/* input */
+	struct xdr_netobj	*na_seclabel;	/* input */
+	struct posix_acl	*na_pacl;	/* input */
+	struct posix_acl	*na_dpacl;	/* input */
+
+	int			na_labelerr;	/* output */
+	int			na_dpaclerr;	/* output */
+	int			na_paclerr;	/* output */
+};
+
+static inline void nfsd_attrs_free(struct nfsd_attrs *attrs)
+{
+	posix_acl_release(attrs->na_pacl);
+	posix_acl_release(attrs->na_dpacl);
+}
+
+static inline bool nfsd_attrs_valid(struct nfsd_attrs *attrs)
+{
+	struct iattr *iap = attrs->na_iattr;
+
+	return (iap->ia_valid || (attrs->na_seclabel &&
+		attrs->na_seclabel->len) ||
+		attrs->na_pacl || attrs->na_dpacl);
+}
+
+__be32		nfserrno (int errno);
+int		nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
+		                struct svc_export **expp);
+__be32		nfsd_lookup(struct svc_rqst *, struct svc_fh *,
+				const char *, unsigned int, struct svc_fh *);
+__be32		 nfsd_lookup_dentry(struct svc_rqst *, struct svc_fh *,
+				const char *, unsigned int,
+				struct svc_export **, struct dentry **);
+__be32		nfsd_setattr(struct svc_rqst *, struct svc_fh *,
+			     struct nfsd_attrs *, const struct timespec64 *);
+int nfsd_mountpoint(struct dentry *, struct svc_export *);
+#ifdef CONFIG_NFSD_V4
+__be32		nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
+				    struct file *, loff_t, loff_t, int);
+__be32		nfsd4_clone_file_range(struct svc_rqst *rqstp,
+				       struct nfsd_file *nf_src, u64 src_pos,
+				       struct nfsd_file *nf_dst, u64 dst_pos,
+				       u64 count, bool sync);
+#endif /* CONFIG_NFSD_V4 */
+__be32		nfsd_create_locked(struct svc_rqst *, struct svc_fh *,
+				struct nfsd_attrs *attrs, int type, dev_t rdev,
+				struct svc_fh *res);
+__be32		nfsd_create(struct svc_rqst *, struct svc_fh *,
+				char *name, int len, struct nfsd_attrs *attrs,
+				int type, dev_t rdev, struct svc_fh *res);
+__be32		nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
+__be32		nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct svc_fh *resfhp, struct nfsd_attrs *iap);
+__be32		nfsd_commit(struct svc_rqst *rqst, struct svc_fh *fhp,
+				struct nfsd_file *nf, u64 offset, u32 count,
+				__be32 *verf);
+#ifdef CONFIG_NFSD_V4
+__be32		nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name, void **bufp, int *lenp);
+__be32		nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char **bufp, int *lenp);
+__be32		nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name);
+__be32		nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name, void *buf, u32 len, u32 flags);
+#endif
+int 		nfsd_open_break_lease(struct inode *, int);
+__be32		nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
+				int, struct file **);
+int		nfsd_open_verified(struct svc_fh *fhp, umode_t type, int may_flags,
+				struct file **filp);
+__be32		nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct file *file, loff_t offset,
+				unsigned long *count,
+				u32 *eof);
+__be32		nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct nfsd_file *nf, loff_t offset,
+				unsigned long *count, unsigned int base,
+				u32 *eof);
+bool		nfsd_read_splice_ok(struct svc_rqst *rqstp);
+__be32		nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				loff_t offset, unsigned long *count,
+				u32 *eof);
+__be32		nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				loff_t offset, const struct xdr_buf *payload,
+				unsigned long *cnt, int stable, __be32 *verf);
+__be32		nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct nfsd_file *nf, loff_t offset,
+				const struct xdr_buf *payload,
+				unsigned long *cnt, int stable, __be32 *verf);
+__be32		nfsd_readlink(struct svc_rqst *, struct svc_fh *,
+				char *, int *);
+__be32		nfsd_symlink(struct svc_rqst *, struct svc_fh *,
+			     char *name, int len, char *path,
+			     struct nfsd_attrs *attrs,
+			     struct svc_fh *res);
+__be32		nfsd_link(struct svc_rqst *, struct svc_fh *,
+				char *, int, struct svc_fh *);
+ssize_t		nfsd_copy_file_range(struct file *, u64,
+				     struct file *, u64, u64);
+__be32		nfsd_rename(struct svc_rqst *,
+				struct svc_fh *, char *, int,
+				struct svc_fh *, char *, int);
+__be32		nfsd_unlink(struct svc_rqst *, struct svc_fh *, int type,
+				char *name, int len);
+__be32		nfsd_readdir(struct svc_rqst *, struct svc_fh *,
+			     loff_t *, struct readdir_cd *, nfsd_filldir_t);
+__be32		nfsd_statfs(struct svc_rqst *, struct svc_fh *,
+				struct kstatfs *, int access);
+int		nfsd_get_case_info(struct dentry *dentry,
+				   bool *case_insensitive,
+				   bool *case_preserving);
+
+__be32		nfsd_permission(struct svc_cred *cred, struct svc_export *exp,
+				struct dentry *dentry, int acc);
+
+void		nfsd_filp_close(struct file *fp);
+
+#endif /* LINUX_NFSD_VFS_H */
diff --git a/fs/nfsd/xdr.h b/fs/nfsd/xdr.h
new file mode 100644
index 000000000..df540c940
--- /dev/null
+++ b/fs/nfsd/xdr.h
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* XDR types for nfsd. This is mainly a typing exercise. */
+
+#ifndef LINUX_NFSD_H
+#define LINUX_NFSD_H
+
+#include <linux/vfs.h>
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "vfs.h"
+
+struct nfsd_fhandle {
+	struct svc_fh		fh;
+};
+
+struct nfsd_sattrargs {
+	struct svc_fh		fh;
+	struct iattr		attrs;
+};
+
+struct nfsd_diropargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+};
+
+struct nfsd_readargs {
+	struct svc_fh		fh;
+	__u32			offset;
+	__u32			count;
+};
+
+struct nfsd_writeargs {
+	svc_fh			fh;
+	__u32			offset;
+	__u32			len;
+	struct xdr_buf		payload;
+};
+
+struct nfsd_createargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	struct iattr		attrs;
+};
+
+struct nfsd_renameargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd_linkargs {
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd_symlinkargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	char *			tname;
+	unsigned int		tlen;
+	struct iattr		attrs;
+	struct kvec		first;
+};
+
+struct nfsd_readdirargs {
+	struct svc_fh		fh;
+	__u32			cookie;
+	__u32			count;
+};
+
+struct nfsd_stat {
+	__be32			status;
+};
+
+struct nfsd_attrstat {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat		stat;
+};
+
+struct nfsd_diropres  {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat		stat;
+};
+
+struct nfsd_readlinkres {
+	__be32			status;
+	int			len;
+	struct page		*page;
+};
+
+struct nfsd_readres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	struct kstat		stat;
+	struct page		**pages;
+};
+
+struct nfsd_readdirres {
+	/* Components of the reply */
+	__be32			status;
+
+	int			count;
+
+	/* Used to encode the reply's entry list */
+	struct xdr_stream	xdr;
+	struct xdr_buf		dirlist;
+	struct readdir_cd	common;
+	unsigned int		cookie_offset;
+};
+
+struct nfsd_statfsres {
+	__be32			status;
+	struct kstatfs		stats;
+};
+
+/*
+ * Storage requirements for XDR arguments and results.
+ */
+union nfsd_xdrstore {
+	struct nfsd_sattrargs	sattr;
+	struct nfsd_diropargs	dirop;
+	struct nfsd_readargs	read;
+	struct nfsd_writeargs	write;
+	struct nfsd_createargs	create;
+	struct nfsd_renameargs	rename;
+	struct nfsd_linkargs	link;
+	struct nfsd_symlinkargs	symlink;
+	struct nfsd_readdirargs	readdir;
+};
+
+#define NFS2_SVC_XDRSIZE	sizeof(union nfsd_xdrstore)
+
+
+bool nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+
+bool nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+
+void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset);
+int nfssvc_encode_entry(void *data, const char *name, int namlen,
+			loff_t offset, u64 ino, unsigned int d_type);
+
+void nfssvc_release_attrstat(struct svc_rqst *rqstp);
+void nfssvc_release_diropres(struct svc_rqst *rqstp);
+void nfssvc_release_readres(struct svc_rqst *rqstp);
+
+/* Helper functions for NFSv2 ACL code */
+bool svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp);
+bool svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status);
+bool svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+			 const struct svc_fh *fhp, const struct kstat *stat);
+
+#endif /* LINUX_NFSD_H */
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
new file mode 100644
index 000000000..344203874
--- /dev/null
+++ b/fs/nfsd/xdr3.h
@@ -0,0 +1,315 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * XDR types for NFSv3 in nfsd.
+ *
+ * Copyright (C) 1996-1998, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef _LINUX_NFSD_XDR3_H
+#define _LINUX_NFSD_XDR3_H
+
+#include "xdr.h"
+#include "vfs.h"
+
+struct nfsd3_sattrargs {
+	struct svc_fh		fh;
+	struct iattr		attrs;
+	int			check_guard;
+	struct timespec64	guardtime;
+};
+
+struct nfsd3_diropargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+};
+
+struct nfsd3_accessargs {
+	struct svc_fh		fh;
+	__u32			access;
+};
+
+struct nfsd3_readargs {
+	struct svc_fh		fh;
+	__u64			offset;
+	__u32			count;
+};
+
+struct nfsd3_writeargs {
+	svc_fh			fh;
+	__u64			offset;
+	__u32			count;
+	int			stable;
+	__u32			len;
+	struct xdr_buf		payload;
+};
+
+struct nfsd3_createargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	int			createmode;
+	struct iattr		attrs;
+	__be32 *		verf;
+};
+
+struct nfsd3_mknodargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	__u32			ftype;
+	__u32			major, minor;
+	struct iattr		attrs;
+};
+
+struct nfsd3_renameargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd3_linkargs {
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd3_symlinkargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	char *			tname;
+	unsigned int		tlen;
+	struct iattr		attrs;
+	struct kvec		first;
+};
+
+struct nfsd3_readdirargs {
+	struct svc_fh		fh;
+	__u64			cookie;
+	__u32			count;
+	__be32 *		verf;
+};
+
+struct nfsd3_commitargs {
+	struct svc_fh		fh;
+	__u64			offset;
+	__u32			count;
+};
+
+struct nfsd3_getaclargs {
+	struct svc_fh		fh;
+	__u32			mask;
+};
+
+struct posix_acl;
+struct nfsd3_setaclargs {
+	struct svc_fh		fh;
+	__u32			mask;
+	struct posix_acl	*acl_access;
+	struct posix_acl	*acl_default;
+};
+
+struct nfsd3_attrstat {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat            stat;
+};
+
+/* LOOKUP, CREATE, MKDIR, SYMLINK, MKNOD */
+struct nfsd3_diropres  {
+	__be32			status;
+	struct svc_fh		dirfh;
+	struct svc_fh		fh;
+};
+
+struct nfsd3_accessres {
+	__be32			status;
+	struct svc_fh		fh;
+	__u32			access;
+	struct kstat		stat;
+};
+
+struct nfsd3_readlinkres {
+	__be32			status;
+	struct svc_fh		fh;
+	__u32			len;
+	struct page		**pages;
+};
+
+struct nfsd3_readres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	__u32			eof;
+	struct page		**pages;
+};
+
+struct nfsd3_writeres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	int			committed;
+	__be32			verf[2];
+};
+
+struct nfsd3_renameres {
+	__be32			status;
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+};
+
+struct nfsd3_linkres {
+	__be32			status;
+	struct svc_fh		tfh;
+	struct svc_fh		fh;
+};
+
+struct nfsd3_readdirres {
+	/* Components of the reply */
+	__be32			status;
+	struct svc_fh		fh;
+	__be32			verf[2];
+
+	/* Used to encode the reply's entry list */
+	struct xdr_stream	xdr;
+	struct xdr_buf		dirlist;
+	struct svc_fh		scratch;
+	struct readdir_cd	common;
+	unsigned int		cookie_offset;
+	struct svc_rqst *	rqstp;
+
+};
+
+struct nfsd3_fsstatres {
+	__be32			status;
+	struct kstatfs		stats;
+	__u32			invarsec;
+};
+
+struct nfsd3_fsinfores {
+	__be32			status;
+	__u32			f_rtmax;
+	__u32			f_rtpref;
+	__u32			f_rtmult;
+	__u32			f_wtmax;
+	__u32			f_wtpref;
+	__u32			f_wtmult;
+	__u32			f_dtpref;
+	__u64			f_maxfilesize;
+	__u32			f_properties;
+};
+
+struct nfsd3_pathconfres {
+	__be32			status;
+	__u32			p_link_max;
+	__u32			p_name_max;
+	__u32			p_no_trunc;
+	__u32			p_chown_restricted;
+	bool			p_case_insensitive;
+	bool			p_case_preserving;
+};
+
+struct nfsd3_commitres {
+	__be32			status;
+	struct svc_fh		fh;
+	__be32			verf[2];
+};
+
+struct nfsd3_getaclres {
+	__be32			status;
+	struct svc_fh		fh;
+	int			mask;
+	struct posix_acl	*acl_access;
+	struct posix_acl	*acl_default;
+	struct kstat		stat;
+};
+
+/* dummy type for release */
+struct nfsd3_fhandle_pair {
+	__u32			dummy;
+	struct svc_fh		fh1;
+	struct svc_fh		fh2;
+};
+
+/*
+ * Storage requirements for XDR arguments and results.
+ */
+union nfsd3_xdrstore {
+	struct nfsd3_sattrargs		sattrargs;
+	struct nfsd3_diropargs		diropargs;
+	struct nfsd3_readargs		readargs;
+	struct nfsd3_writeargs		writeargs;
+	struct nfsd3_createargs		createargs;
+	struct nfsd3_renameargs		renameargs;
+	struct nfsd3_linkargs		linkargs;
+	struct nfsd3_symlinkargs	symlinkargs;
+	struct nfsd3_readdirargs	readdirargs;
+	struct nfsd3_diropres 		diropres;
+	struct nfsd3_accessres		accessres;
+	struct nfsd3_readlinkres	readlinkres;
+	struct nfsd3_readres		readres;
+	struct nfsd3_writeres		writeres;
+	struct nfsd3_renameres		renameres;
+	struct nfsd3_linkres		linkres;
+	struct nfsd3_readdirres		readdirres;
+	struct nfsd3_fsstatres		fsstatres;
+	struct nfsd3_fsinfores		fsinfores;
+	struct nfsd3_pathconfres	pathconfres;
+	struct nfsd3_commitres		commitres;
+	struct nfsd3_getaclres		getaclres;
+};
+
+#define NFS3_SVC_XDRSIZE		sizeof(union nfsd3_xdrstore)
+
+bool nfs3svc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_accessargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_decode_commitargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+
+bool nfs3svc_encode_getattrres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_wccstat(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_lookupres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_accessres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_writeres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_createres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_renameres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_linkres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs3svc_encode_commitres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+
+void nfs3svc_release_fhandle(struct svc_rqst *);
+void nfs3svc_release_fhandle2(struct svc_rqst *);
+
+void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset);
+int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
+			  loff_t offset, u64 ino, unsigned int d_type);
+int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
+			      loff_t offset, u64 ino, unsigned int d_type);
+/* Helper functions for NFSv3 ACL code */
+bool svcxdr_decode_nfs_fh3(struct xdr_stream *xdr, struct svc_fh *fhp);
+bool svcxdr_encode_nfsstat3(struct xdr_stream *xdr, __be32 status);
+bool svcxdr_encode_post_op_attr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+				const struct svc_fh *fhp);
+
+#endif /* _LINUX_NFSD_XDR3_H */
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
new file mode 100644
index 000000000..c7eda5bc8
--- /dev/null
+++ b/fs/nfsd/xdr4.h
@@ -0,0 +1,1098 @@
+/*
+ *  Server-side types for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef _LINUX_NFSD_XDR4_H
+#define _LINUX_NFSD_XDR4_H
+
+#include "state.h"
+#include "vfs.h"
+
+#define NFSD4_MAX_TAGLEN	128
+#define XDR_LEN(n)                     (((n) + 3) & ~3)
+
+#define CURRENT_STATE_ID_FLAG (1<<0)
+#define SAVED_STATE_ID_FLAG (1<<1)
+
+#define SET_CSTATE_FLAG(c, f) ((c)->sid_flags |= (f))
+#define HAS_CSTATE_FLAG(c, f) ((c)->sid_flags & (f))
+#define CLEAR_CSTATE_FLAG(c, f) ((c)->sid_flags &= ~(f))
+
+/**
+ * nfsd4_encode_bool - Encode an XDR bool type result
+ * @xdr: target XDR stream
+ * @val: boolean value to encode
+ *
+ * Return values:
+ *    %nfs_ok: @val encoded; @xdr advanced to next position
+ *    %nfserr_resource: stream buffer space exhausted
+ */
+static __always_inline __be32
+nfsd4_encode_bool(struct xdr_stream *xdr, bool val)
+{
+	__be32 *p = xdr_reserve_space(xdr, XDR_UNIT);
+
+	if (unlikely(p == NULL))
+		return nfserr_resource;
+	*p = val ? xdr_one : xdr_zero;
+	return nfs_ok;
+}
+
+/**
+ * nfsd4_encode_uint32_t - Encode an XDR uint32_t type result
+ * @xdr: target XDR stream
+ * @val: integer value to encode
+ *
+ * Return values:
+ *    %nfs_ok: @val encoded; @xdr advanced to next position
+ *    %nfserr_resource: stream buffer space exhausted
+ */
+static __always_inline __be32
+nfsd4_encode_uint32_t(struct xdr_stream *xdr, u32 val)
+{
+	__be32 *p = xdr_reserve_space(xdr, XDR_UNIT);
+
+	if (unlikely(p == NULL))
+		return nfserr_resource;
+	*p = cpu_to_be32(val);
+	return nfs_ok;
+}
+
+#define nfsd4_encode_aceflag4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_acemask4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_acetype4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_count4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_mode4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_nfs_lease4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_qop4(x, v)		nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_sequenceid4(x, v)	nfsd4_encode_uint32_t(x, v)
+#define nfsd4_encode_slotid4(x, v)	nfsd4_encode_uint32_t(x, v)
+
+/**
+ * nfsd4_encode_uint64_t - Encode an XDR uint64_t type result
+ * @xdr: target XDR stream
+ * @val: integer value to encode
+ *
+ * Return values:
+ *    %nfs_ok: @val encoded; @xdr advanced to next position
+ *    %nfserr_resource: stream buffer space exhausted
+ */
+static __always_inline __be32
+nfsd4_encode_uint64_t(struct xdr_stream *xdr, u64 val)
+{
+	__be32 *p = xdr_reserve_space(xdr, XDR_UNIT * 2);
+
+	if (unlikely(p == NULL))
+		return nfserr_resource;
+	put_unaligned_be64(val, p);
+	return nfs_ok;
+}
+
+#define nfsd4_encode_changeid4(x, v)	nfsd4_encode_uint64_t(x, v)
+#define nfsd4_encode_nfs_cookie4(x, v)	nfsd4_encode_uint64_t(x, v)
+#define nfsd4_encode_length4(x, v)	nfsd4_encode_uint64_t(x, v)
+#define nfsd4_encode_offset4(x, v)	nfsd4_encode_uint64_t(x, v)
+
+/**
+ * nfsd4_encode_opaque_fixed - Encode a fixed-length XDR opaque type result
+ * @xdr: target XDR stream
+ * @data: pointer to data
+ * @size: length of data in bytes
+ *
+ * Return values:
+ *    %nfs_ok: @data encoded; @xdr advanced to next position
+ *    %nfserr_resource: stream buffer space exhausted
+ */
+static __always_inline __be32
+nfsd4_encode_opaque_fixed(struct xdr_stream *xdr, const void *data,
+			  size_t size)
+{
+	__be32 *p = xdr_reserve_space(xdr, xdr_align_size(size));
+	size_t pad = xdr_pad_size(size);
+
+	if (unlikely(p == NULL))
+		return nfserr_resource;
+	memcpy(p, data, size);
+	if (pad)
+		memset((char *)p + size, 0, pad);
+	return nfs_ok;
+}
+
+/**
+ * nfsd4_encode_opaque - Encode a variable-length XDR opaque type result
+ * @xdr: target XDR stream
+ * @data: pointer to data
+ * @size: length of data in bytes
+ *
+ * Return values:
+ *    %nfs_ok: @data encoded; @xdr advanced to next position
+ *    %nfserr_resource: stream buffer space exhausted
+ */
+static __always_inline __be32
+nfsd4_encode_opaque(struct xdr_stream *xdr, const void *data, size_t size)
+{
+	size_t pad = xdr_pad_size(size);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT + xdr_align_size(size));
+	if (unlikely(p == NULL))
+		return nfserr_resource;
+	*p++ = cpu_to_be32(size);
+	memcpy(p, data, size);
+	if (pad)
+		memset((char *)p + size, 0, pad);
+	return nfs_ok;
+}
+
+#define nfsd4_encode_component4(x, d, s)	nfsd4_encode_opaque(x, d, s)
+
+struct nfsd4_compound_state {
+	struct svc_fh		current_fh;
+	struct svc_fh		save_fh;
+	struct nfs4_stateowner	*replay_owner;
+	struct nfs4_client	*clp;
+	/* For sessions DRC */
+	struct nfsd4_session	*session;
+	struct nfsd4_slot	*slot;
+	int			data_offset;
+	bool                    spo_must_allowed;
+	size_t			iovlen;
+	u32			minorversion;
+	__be32			status;
+	stateid_t	current_stateid;
+	stateid_t	save_stateid;
+	/* to indicate current and saved state id presents */
+	u32		sid_flags;
+};
+
+static inline bool nfsd4_has_session(struct nfsd4_compound_state *cs)
+{
+	return cs->slot != NULL;
+}
+
+struct nfsd4_change_info {
+	u32		atomic;
+	u64		before_change;
+	u64		after_change;
+};
+
+struct nfsd4_access {
+	u32		ac_req_access;      /* request */
+	u32		ac_supported;       /* response */
+	u32		ac_resp_access;     /* response */
+};
+
+struct nfsd4_close {
+	u32		cl_seqid;           /* request */
+	stateid_t	cl_stateid;         /* request+response */
+};
+
+struct nfsd4_commit {
+	u64		co_offset;          /* request */
+	u32		co_count;           /* request */
+	nfs4_verifier	co_verf;            /* response */
+};
+
+struct nfsd4_create {
+	u32		cr_namelen;         /* request */
+	char *		cr_name;            /* request */
+	u32		cr_type;            /* request */
+	union {                             /* request */
+		struct {
+			u32 datalen;
+			char *data;
+			struct kvec first;
+		} link;   /* NF4LNK */
+		struct {
+			u32 specdata1;
+			u32 specdata2;
+		} dev;    /* NF4BLK, NF4CHR */
+	} u;
+	u32		cr_bmval[3];        /* request */
+	struct iattr	cr_iattr;           /* request */
+	int		cr_umask;           /* request */
+	struct nfsd4_change_info  cr_cinfo; /* response */
+	struct nfs4_acl *cr_acl;
+	struct posix_acl *cr_dpacl;
+	struct posix_acl *cr_pacl;
+	struct xdr_netobj cr_label;
+};
+#define cr_datalen	u.link.datalen
+#define cr_data		u.link.data
+#define cr_first	u.link.first
+#define cr_specdata1	u.dev.specdata1
+#define cr_specdata2	u.dev.specdata2
+
+struct nfsd4_delegreturn {
+	stateid_t	dr_stateid;
+};
+
+struct nfsd4_getattr {
+	u32		ga_bmval[3];        /* request */
+	struct svc_fh	*ga_fhp;            /* response */
+};
+
+struct nfsd4_link {
+	u32		li_namelen;         /* request */
+	char *		li_name;            /* request */
+	struct nfsd4_change_info  li_cinfo; /* response */
+};
+
+struct nfsd4_lock_denied {
+	clientid_t	ld_clientid;
+	struct xdr_netobj	ld_owner;
+	u64             ld_start;
+	u64             ld_length;
+	u32             ld_type;
+};
+
+struct nfsd4_lock {
+	/* request */
+	u32             lk_type;
+	u32             lk_reclaim;         /* boolean */
+	u64             lk_offset;
+	u64             lk_length;
+	u32             lk_is_new;
+	union {
+		struct {
+			u32             open_seqid;
+			stateid_t       open_stateid;
+			u32             lock_seqid;
+			clientid_t      clientid;
+			struct xdr_netobj owner;
+		} new;
+		struct {
+			stateid_t       lock_stateid;
+			u32             lock_seqid;
+		} old;
+	} v;
+
+	/* response */
+	stateid_t			lk_resp_stateid;
+	struct nfsd4_lock_denied        lk_denied;
+};
+#define lk_new_open_seqid       v.new.open_seqid
+#define lk_new_open_stateid     v.new.open_stateid
+#define lk_new_lock_seqid       v.new.lock_seqid
+#define lk_new_clientid         v.new.clientid
+#define lk_new_owner            v.new.owner
+#define lk_old_lock_stateid     v.old.lock_stateid
+#define lk_old_lock_seqid       v.old.lock_seqid
+
+struct nfsd4_lockt {
+	u32				lt_type;
+	clientid_t			lt_clientid;
+	struct xdr_netobj		lt_owner;
+	u64				lt_offset;
+	u64				lt_length;
+	struct nfsd4_lock_denied	lt_denied;
+};
+
+struct nfsd4_locku {
+	u32             lu_type;
+	u32             lu_seqid;
+	stateid_t       lu_stateid;
+	u64             lu_offset;
+	u64             lu_length;
+};
+
+
+struct nfsd4_lookup {
+	u32		lo_len;             /* request */
+	char *		lo_name;            /* request */
+};
+
+struct nfsd4_putfh {
+	u32		pf_fhlen;           /* request */
+	char		*pf_fhval;          /* request */
+	bool		no_verify;	    /* represents foreigh fh */
+};
+
+struct nfsd4_getxattr {
+	char		*getxa_name;		/* request */
+	u32		getxa_len;		/* request */
+	void		*getxa_buf;
+};
+
+struct nfsd4_setxattr {
+	u32		setxa_flags;		/* request */
+	char		*setxa_name;		/* request */
+	char		*setxa_buf;		/* request */
+	u32		setxa_len;		/* request */
+	struct nfsd4_change_info  setxa_cinfo;	/* response */
+};
+
+struct nfsd4_removexattr {
+	char		*rmxa_name;		/* request */
+	struct nfsd4_change_info  rmxa_cinfo;	/* response */
+};
+
+struct nfsd4_listxattrs {
+	u64		lsxa_cookie;		/* request */
+	u32		lsxa_maxcount;		/* request */
+	char		*lsxa_buf;		/* unfiltered buffer (reply) */
+	u32		lsxa_len;		/* unfiltered len (reply) */
+};
+
+struct nfsd4_open {
+	u32		op_claim_type;      /* request */
+	u32		op_fnamelen;
+	char *		op_fname;	    /* request - everything but CLAIM_PREV */
+	u32		op_delegate_type;   /* request - CLAIM_PREV only */
+	stateid_t       op_delegate_stateid; /* request - response */
+	u32		op_why_no_deleg;    /* response - DELEG_NONE_EXT only */
+	u32		op_create;     	    /* request */
+	u32		op_createmode;      /* request */
+	int		op_umask;           /* request */
+	u32		op_bmval[3];        /* request */
+	struct iattr	op_iattr;           /* UNCHECKED4, GUARDED4, EXCLUSIVE4_1 */
+	nfs4_verifier	op_verf __attribute__((aligned(32)));
+					    /* EXCLUSIVE4 */
+	clientid_t	op_clientid;        /* request */
+	struct xdr_netobj op_owner;           /* request */
+	u32		op_seqid;           /* request */
+	u32		op_share_access;    /* request */
+	u32		op_share_deny;      /* request */
+	u32		op_deleg_want;      /* request */
+	stateid_t	op_stateid;         /* response */
+	__be32		op_xdr_error;       /* see nfsd4_open_omfg() */
+	struct nfsd4_change_info  op_cinfo; /* response */
+	u32		op_rflags;          /* response */
+	bool		op_recall;          /* response */
+	bool		op_truncate;        /* used during processing */
+	bool		op_created;         /* used during processing */
+	struct nfs4_openowner *op_openowner; /* used during processing */
+	struct file	*op_filp;           /* used during processing */
+	struct nfs4_file *op_file;          /* used during processing */
+	struct nfs4_ol_stateid *op_stp;	    /* used during processing */
+	struct nfs4_clnt_odstate *op_odstate; /* used during processing */
+	struct nfs4_acl *op_acl;
+	struct posix_acl *op_dpacl;
+	struct posix_acl *op_pacl;
+	struct xdr_netobj op_label;
+	struct svc_rqst *op_rqstp;
+};
+
+struct nfsd4_open_confirm {
+	stateid_t	oc_req_stateid		/* request */;
+	u32		oc_seqid    		/* request */;
+	stateid_t	oc_resp_stateid		/* response */;
+};
+
+struct nfsd4_open_downgrade {
+	stateid_t       od_stateid;
+	u32             od_seqid;
+	u32             od_share_access;	/* request */
+	u32		od_deleg_want;		/* request */
+	u32             od_share_deny;		/* request */
+};
+
+
+struct nfsd4_read {
+	stateid_t		rd_stateid;         /* request */
+	u64			rd_offset;          /* request */
+	u32			rd_length;          /* request */
+	int			rd_vlen;
+	struct nfsd_file	*rd_nf;
+
+	struct svc_rqst		*rd_rqstp;          /* response */
+	struct svc_fh		*rd_fhp;            /* response */
+	u32			rd_eof;             /* response */
+};
+
+/*
+ * Cache the case-folding properties of @dir so a batched encoder
+ * (e.g., READDIR) does not re-probe per child. @dir is the
+ * directory being read, held by the request, so it is stable
+ * against rename for the duration of the cache's lifetime.
+ */
+struct nfsd_case_attrs_cache {
+	struct dentry	*dir;
+	bool		valid;
+	bool		insensitive;
+	bool		preserving;
+};
+
+struct nfsd4_readdir {
+	u64		rd_cookie;          /* request */
+	nfs4_verifier	rd_verf;            /* request */
+	u32		rd_dircount;        /* request */
+	u32		rd_maxcount;        /* request */
+	u32		rd_bmval[3];        /* request */
+	struct svc_rqst *rd_rqstp;          /* response */
+	struct svc_fh * rd_fhp;             /* response */
+
+	struct readdir_cd	common;
+	struct xdr_stream	*xdr;
+	int			cookie_offset;
+	struct nfsd_case_attrs_cache rd_case_cache;
+};
+
+struct nfsd4_release_lockowner {
+	clientid_t        rl_clientid;
+	struct xdr_netobj rl_owner;
+};
+struct nfsd4_readlink {
+	struct svc_rqst *rl_rqstp;          /* request */
+	struct svc_fh *	rl_fhp;             /* request */
+};
+
+struct nfsd4_remove {
+	u32		rm_namelen;         /* request */
+	char *		rm_name;            /* request */
+	struct nfsd4_change_info  rm_cinfo; /* response */
+};
+
+struct nfsd4_rename {
+	u32		rn_snamelen;        /* request */
+	char *		rn_sname;           /* request */
+	u32		rn_tnamelen;        /* request */
+	char *		rn_tname;           /* request */
+	struct nfsd4_change_info  rn_sinfo; /* response */
+	struct nfsd4_change_info  rn_tinfo; /* response */
+};
+
+struct nfsd4_secinfo {
+	u32 si_namelen;					/* request */
+	char *si_name;					/* request */
+	struct svc_export *si_exp;			/* response */
+};
+
+struct nfsd4_secinfo_no_name {
+	u32 sin_style;					/* request */
+	struct svc_export *sin_exp;			/* response */
+};
+
+struct nfsd4_setattr {
+	stateid_t	sa_stateid;         /* request */
+	u32		sa_bmval[3];        /* request */
+	struct iattr	sa_iattr;           /* request */
+	struct nfs4_acl *sa_acl;
+	struct xdr_netobj sa_label;
+	struct posix_acl *sa_dpacl;
+	struct posix_acl *sa_pacl;
+};
+
+struct nfsd4_setclientid {
+	nfs4_verifier	se_verf;            /* request */
+	struct xdr_netobj se_name;
+	u32		se_callback_prog;   /* request */
+	u32		se_callback_netid_len;  /* request */
+	char *		se_callback_netid_val;  /* request */
+	u32		se_callback_addr_len;   /* request */
+	char *		se_callback_addr_val;   /* request */
+	u32		se_callback_ident;  /* request */
+	clientid_t	se_clientid;        /* response */
+	nfs4_verifier	se_confirm;         /* response */
+};
+
+struct nfsd4_setclientid_confirm {
+	clientid_t	sc_clientid;
+	nfs4_verifier	sc_confirm;
+};
+
+struct nfsd4_test_stateid_id {
+	__be32			ts_id_status;
+	stateid_t		ts_id_stateid;
+	struct list_head	ts_id_list;
+};
+
+struct nfsd4_test_stateid {
+	u32		ts_num_ids;
+	struct list_head ts_stateid_list;
+};
+
+struct nfsd4_free_stateid {
+	stateid_t	fr_stateid;         /* request */
+};
+
+struct nfsd4_get_dir_delegation {
+	/* request */
+	u32			gdda_signal_deleg_avail;
+	u32			gdda_notification_types[1];
+	struct timespec64	gdda_child_attr_delay;
+	struct timespec64	gdda_dir_attr_delay;
+	u32			gdda_child_attributes[3];
+	u32			gdda_dir_attributes[3];
+	/* response */
+	u32			gddrnf_status;
+	nfs4_verifier		gddr_cookieverf;
+	stateid_t		gddr_stateid;
+	u32			gddr_notification[1];
+	u32			gddr_child_attributes[3];
+	u32			gddr_dir_attributes[3];
+	bool			gddrnf_will_signal_deleg_avail;
+};
+
+/* also used for NVERIFY */
+struct nfsd4_verify {
+	u32		ve_bmval[3];        /* request */
+	u32		ve_attrlen;         /* request */
+	char *		ve_attrval;         /* request */
+};
+
+struct nfsd4_write {
+	stateid_t	wr_stateid;         /* request */
+	u64		wr_offset;          /* request */
+	u32		wr_stable_how;      /* request */
+	u32		wr_buflen;          /* request */
+	struct xdr_buf	wr_payload;         /* request */
+
+	u32		wr_bytes_written;   /* response */
+	u32		wr_how_written;     /* response */
+	nfs4_verifier	wr_verifier;        /* response */
+};
+
+struct nfsd4_exchange_id {
+	nfs4_verifier	verifier;
+	struct xdr_netobj clname;
+	u32		flags;
+	clientid_t	clientid;
+	u32		seqid;
+	u32		spa_how;
+	u32             spo_must_enforce[3];
+	u32             spo_must_allow[3];
+	struct xdr_netobj nii_domain;
+	struct xdr_netobj nii_name;
+	struct timespec64 nii_time;
+	char		*server_impl_name;
+};
+
+struct nfsd4_sequence {
+	struct nfs4_sessionid	sessionid;		/* request/response */
+	u32			seqid;			/* request/response */
+	u32			slotid;			/* request/response */
+	u32			maxslots;		/* request */
+	u32			cachethis;		/* request */
+	u32			maxslots_response;	/* response */
+	u32			target_maxslots;	/* response */
+	u32			status_flags;		/* response */
+};
+
+struct nfsd4_destroy_session {
+	struct nfs4_sessionid	sessionid;
+};
+
+struct nfsd4_destroy_clientid {
+	clientid_t clientid;
+};
+
+struct nfsd4_reclaim_complete {
+	u32 rca_one_fs;
+};
+
+struct nfsd4_deviceid {
+	u64			fsid_idx;
+	u32			generation;
+};
+
+static inline __be32 *
+svcxdr_encode_deviceid4(__be32 *p, const struct nfsd4_deviceid *devid)
+{
+	__be64 *q = (__be64 *)p;
+
+	*q = (__force __be64)devid->fsid_idx;
+	p += 2;
+	*p++ = (__force __be32)devid->generation;
+	*p++ = xdr_zero;
+	return p;
+}
+
+static inline __be32 *
+svcxdr_decode_deviceid4(__be32 *p, struct nfsd4_deviceid *devid)
+{
+	__be64 *q = (__be64 *)p;
+
+	devid->fsid_idx = (__force u64)(*q);
+	p += 2;
+	devid->generation = (__force u32)(*p++);
+	p++; /* NFSD does not use the remaining octets */
+	return p;
+}
+
+static inline __be32
+nfsd4_decode_deviceid4(struct xdr_stream *xdr, struct nfsd4_deviceid *devid)
+{
+	__be32 *p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
+
+	if (unlikely(!p))
+		return nfserr_bad_xdr;
+	svcxdr_decode_deviceid4(p, devid);
+	return nfs_ok;
+}
+
+struct nfsd4_layout_seg {
+	u32			iomode;
+	u64			offset;
+	u64			length;
+};
+
+struct nfsd4_getdeviceinfo {
+	struct nfsd4_deviceid	gd_devid;	/* request */
+	u32			gd_layout_type;	/* request */
+	u32			gd_maxcount;	/* request */
+	u32			gd_notify_types;/* request - response */
+	void			*gd_device;	/* response */
+};
+
+struct nfsd4_layoutget {
+	u64			lg_minlength;	/* request */
+	u32			lg_signal;	/* request */
+	u32			lg_layout_type;	/* request */
+	u32			lg_maxcount;	/* request */
+	stateid_t		lg_sid;		/* request/response */
+	struct nfsd4_layout_seg	lg_seg;		/* request/response */
+	void			*lg_content;	/* response */
+};
+
+struct nfsd4_layoutcommit {
+	stateid_t		lc_sid;		/* request */
+	struct nfsd4_layout_seg	lc_seg;		/* request */
+	u32			lc_reclaim;	/* request */
+	u32			lc_newoffset;	/* request */
+	u64			lc_last_wr;	/* request */
+	struct timespec64	lc_mtime;	/* request */
+	u32			lc_layout_type;	/* request */
+	struct xdr_buf		lc_up_layout;	/* decoded by callback */
+	bool			lc_size_chg;	/* response */
+	u64			lc_newsize;	/* response */
+};
+
+struct nfsd4_layoutreturn {
+	u32			lr_return_type;	/* request */
+	u32			lr_layout_type;	/* request */
+	struct nfsd4_layout_seg	lr_seg;		/* request */
+	u32			lr_reclaim;	/* request */
+	u32			lrf_body_len;	/* request */
+	void			*lrf_body;	/* request */
+	stateid_t		lr_sid;		/* request/response */
+	bool			lrs_present;	/* response */
+};
+
+struct nfsd4_fallocate {
+	/* request */
+	stateid_t	falloc_stateid;
+	loff_t		falloc_offset;
+	u64		falloc_length;
+};
+
+struct nfsd4_clone {
+	/* request */
+	stateid_t	cl_src_stateid;
+	stateid_t	cl_dst_stateid;
+	u64		cl_src_pos;
+	u64		cl_dst_pos;
+	u64		cl_count;
+};
+
+struct nfsd42_write_res {
+	u64			wr_bytes_written;
+	u32			wr_stable_how;
+	nfs4_verifier		wr_verifier;
+	stateid_t		cb_stateid;
+};
+
+struct nfsd4_cb_offload {
+	struct nfsd4_callback	co_cb;
+	struct nfsd42_write_res	co_res;
+	__be32			co_nfserr;
+	unsigned int		co_retries;
+	struct knfsd_fh		co_fh;
+
+	struct nfs4_sessionid	co_referring_sessionid;
+	u32			co_referring_slotid;
+	u32			co_referring_seqno;
+};
+
+struct nfsd4_copy {
+	/* request */
+	stateid_t		cp_src_stateid;
+	stateid_t		cp_dst_stateid;
+	u64			cp_src_pos;
+	u64			cp_dst_pos;
+	u64			cp_count;
+	struct nl4_server	*cp_src;
+
+	unsigned long		cp_flags;
+#define NFSD4_COPY_F_STOPPED		(0)
+#define NFSD4_COPY_F_INTRA		(1)
+#define NFSD4_COPY_F_SYNCHRONOUS	(2)
+#define NFSD4_COPY_F_COMMITTED		(3)
+#define NFSD4_COPY_F_COMPLETED		(4)
+#define NFSD4_COPY_F_OFFLOAD_DONE	(5)
+#define NFSD4_COPY_F_CB_ERROR		(6)
+
+	/* response */
+	__be32			nfserr;
+	struct nfsd42_write_res	cp_res;
+	struct knfsd_fh		fh;
+
+	struct nfs4_client      *cp_clp;
+
+	struct nfsd_file        *nf_src;
+	struct nfsd_file        *nf_dst;
+	bool			attr_update;
+
+	struct nfsd4_ssc_umount_item *ss_nsui;
+	struct nfs_fh		c_fh;
+	nfs4_stateid		stateid;
+	struct nfsd_net		*cp_nn;
+};
+
+/*
+ * Durable state for an async (background) server-side COPY.
+ *
+ * struct nfsd4_copy is transient: it lives in the COMPOUND argument buffer
+ * and is reused once the op returns. An async COPY outlives the COMPOUND
+ * (worker kthread, reaper linkage, CB_OFFLOAD), so its params and result are
+ * snapshotted into the embedded cp_copy and it never points into the request
+ * buffer.
+ */
+struct nfsd4_async_copy {
+	struct nfs4_stid	cp_stid;	/* SC_TYPE_COPY, in cl_stateids */
+	struct nfsd4_copy	cp_copy;	/* operation params + result */
+
+	struct list_head	copies;		/* nfs4_client.async_copies */
+	struct task_struct	*copy_task;
+	refcount_t		refcount;
+	unsigned int		cp_ttl;
+	struct nfsd4_cb_offload	cp_cb_offload;
+};
+
+static inline void nfsd4_copy_set_sync(struct nfsd4_copy *copy, bool sync)
+{
+	if (sync)
+		set_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+	else
+		clear_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+}
+
+static inline bool nfsd4_copy_is_sync(const struct nfsd4_copy *copy)
+{
+	return test_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+}
+
+static inline bool nfsd4_copy_is_async(const struct nfsd4_copy *copy)
+{
+	return !test_bit(NFSD4_COPY_F_SYNCHRONOUS, &copy->cp_flags);
+}
+
+static inline bool nfsd4_ssc_is_inter(const struct nfsd4_copy *copy)
+{
+	return !test_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+}
+
+struct nfsd4_seek {
+	/* request */
+	stateid_t	seek_stateid;
+	loff_t		seek_offset;
+	u32		seek_whence;
+
+	/* response */
+	u32		seek_eof;
+	loff_t		seek_pos;
+};
+
+struct nfsd4_offload_status {
+	/* request */
+	stateid_t	stateid;
+
+	/* response */
+	u64		count;
+	__be32		status;
+	bool		completed;
+};
+
+struct nfsd4_copy_notify {
+	/* request */
+	stateid_t		cpn_src_stateid;
+	struct nl4_server	*cpn_dst;
+
+	/* response */
+	stateid_t		cpn_cnr_stateid;
+	struct timespec64	cpn_lease_time;
+	struct nl4_server	*cpn_src;
+};
+
+struct nfsd4_op {
+	u32					opnum;
+	__be32					status;
+	const struct nfsd4_operation		*opdesc;
+	struct nfs4_replay			*replay;
+	union nfsd4_op_u {
+		struct nfsd4_access		access;
+		struct nfsd4_close		close;
+		struct nfsd4_commit		commit;
+		struct nfsd4_create		create;
+		struct nfsd4_delegreturn	delegreturn;
+		struct nfsd4_getattr		getattr;
+		struct svc_fh *			getfh;
+		struct nfsd4_link		link;
+		struct nfsd4_lock		lock;
+		struct nfsd4_lockt		lockt;
+		struct nfsd4_locku		locku;
+		struct nfsd4_lookup		lookup;
+		struct nfsd4_verify		nverify;
+		struct nfsd4_open		open;
+		struct nfsd4_open_confirm	open_confirm;
+		struct nfsd4_open_downgrade	open_downgrade;
+		struct nfsd4_putfh		putfh;
+		struct nfsd4_read		read;
+		struct nfsd4_readdir		readdir;
+		struct nfsd4_readlink		readlink;
+		struct nfsd4_remove		remove;
+		struct nfsd4_rename		rename;
+		clientid_t			renew;
+		struct nfsd4_secinfo		secinfo;
+		struct nfsd4_setattr		setattr;
+		struct nfsd4_setclientid	setclientid;
+		struct nfsd4_setclientid_confirm setclientid_confirm;
+		struct nfsd4_verify		verify;
+		struct nfsd4_write		write;
+		struct nfsd4_release_lockowner	release_lockowner;
+
+		/* NFSv4.1 */
+		struct nfsd4_exchange_id	exchange_id;
+		struct nfsd4_backchannel_ctl	backchannel_ctl;
+		struct nfsd4_bind_conn_to_session bind_conn_to_session;
+		struct nfsd4_create_session	create_session;
+		struct nfsd4_destroy_session	destroy_session;
+		struct nfsd4_destroy_clientid	destroy_clientid;
+		struct nfsd4_sequence		sequence;
+		struct nfsd4_reclaim_complete	reclaim_complete;
+		struct nfsd4_test_stateid	test_stateid;
+		struct nfsd4_free_stateid	free_stateid;
+		struct nfsd4_get_dir_delegation	get_dir_delegation;
+		struct nfsd4_getdeviceinfo	getdeviceinfo;
+		struct nfsd4_layoutget		layoutget;
+		struct nfsd4_layoutcommit	layoutcommit;
+		struct nfsd4_layoutreturn	layoutreturn;
+		struct nfsd4_secinfo_no_name	secinfo_no_name;
+
+		/* NFSv4.2 */
+		struct nfsd4_fallocate		allocate;
+		struct nfsd4_fallocate		deallocate;
+		struct nfsd4_clone		clone;
+		struct nfsd4_copy		copy;
+		struct nfsd4_offload_status	offload_status;
+		struct nfsd4_copy_notify	copy_notify;
+		struct nfsd4_seek		seek;
+
+		struct nfsd4_getxattr		getxattr;
+		struct nfsd4_setxattr		setxattr;
+		struct nfsd4_listxattrs		listxattrs;
+		struct nfsd4_removexattr	removexattr;
+	} u;
+};
+
+bool nfsd4_cache_this_op(struct nfsd4_op *);
+
+/*
+ * Memory needed just for the duration of processing one compound:
+ */
+struct svcxdr_tmpbuf {
+	struct svcxdr_tmpbuf *next;
+	char buf[];
+};
+
+struct nfsd4_compoundargs {
+	/* scratch variables for XDR decode */
+	struct xdr_stream		*xdr;
+	struct svcxdr_tmpbuf		*to_free;
+	struct svc_rqst			*rqstp;
+
+	char *				tag;
+	u32				taglen;
+	u32				minorversion;
+	u32				client_opcnt;
+	u32				opcnt;
+	bool				splice_ok;
+	struct nfsd4_op			*ops;
+	struct nfsd4_op			iops[8];
+};
+
+struct nfsd4_compoundres {
+	/* scratch variables for XDR encode */
+	struct xdr_stream		*xdr;
+	struct svc_rqst *		rqstp;
+
+	__be32				*statusp;
+	char *				tag;
+	u32				taglen;
+	u32				opcnt;
+
+	struct nfsd4_compound_state	cstate;
+};
+
+static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	return argp->opcnt == resp->opcnt;
+}
+
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op);
+int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op);
+void warn_on_nonidempotent_op(struct nfsd4_op *op);
+
+#define NFS4_SVC_XDRSIZE		sizeof(struct nfsd4_compoundargs)
+
+bool nfsd4_mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp);
+bool nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+bool nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr);
+__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *, u32);
+void nfsd4_encode_operation(struct nfsd4_compoundres *, struct nfsd4_op *);
+void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op);
+__be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
+		struct svc_fh *fhp, struct svc_export *exp,
+		struct dentry *dentry,
+		u32 *bmval, struct svc_rqst *, int ignore_crossmnt);
+u8 *nfsd4_encode_notify_event(struct xdr_stream *xdr, struct nfsd_notify_event *nne,
+			      struct nfs4_delegation *dd, struct nfsd_file *nf,
+			      u32 *notify_mask);
+u8 *nfsd4_encode_dir_attr_change(struct xdr_stream *xdr, struct nfs4_delegation *dp,
+				 struct nfsd_file *nf);
+extern __be32 nfsd4_setclientid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+void nfsd4_exchange_id_release(union nfsd4_op_u *u);
+extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_backchannel_ctl(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_bind_conn_to_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_create_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_sequence(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern void nfsd4_sequence_done(struct nfsd4_compoundres *resp);
+extern __be32 nfsd4_destroy_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_destroy_clientid(struct svc_rqst *, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+__be32 nfsd4_reclaim_complete(struct svc_rqst *, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_process_open1(struct nfsd4_compound_state *,
+		struct nfsd4_open *open, struct nfsd_net *nn);
+extern __be32 nfsd4_process_open2(struct svc_rqst *rqstp,
+		struct svc_fh *current_fh, struct nfsd4_open *open);
+extern void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate);
+extern void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+		struct nfsd4_open *open);
+extern __be32 nfsd4_open_confirm(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_open_downgrade(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern void nfsd4_lock_release(union nfsd4_op_u *u);
+extern __be32 nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern void nfsd4_lockt_release(union nfsd4_op_u *u);
+extern __be32 nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32
+nfsd4_release_lockowner(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern void nfsd4_release_compoundargs(struct svc_rqst *rqstp);
+extern __be32 nfsd4_delegreturn(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_test_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *);
+extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *);
+extern void nfsd4_bump_seqid(struct nfsd4_compound_state *, __be32 nfserr);
+
+enum nfsd4_op_flags {
+	ALLOWED_WITHOUT_FH = 1 << 0,    /* No current filehandle required */
+	ALLOWED_ON_ABSENT_FS = 1 << 1,  /* ops processed on absent fs */
+	ALLOWED_AS_FIRST_OP = 1 << 2,   /* ops reqired first in compound */
+	/* For rfc 5661 section 2.6.3.1.1: */
+	OP_HANDLES_WRONGSEC = 1 << 3,
+	OP_IS_PUTFH_LIKE = 1 << 4,
+	/*
+	 * These are the ops whose result size we estimate before
+	 * encoding, to avoid performing an op then not being able to
+	 * respond or cache a response.  This includes writes and setattrs
+	 * as well as the operations usually called "nonidempotent":
+	 */
+	OP_MODIFIES_SOMETHING = 1 << 5,
+	/*
+	 * Cache compounds containing these ops in the xid-based drc:
+	 * We use the DRC for compounds containing non-idempotent
+	 * operations, *except* those that are 4.1-specific (since
+	 * sessions provide their own EOS), and except for stateful
+	 * operations other than setclientid and setclientid_confirm
+	 * (since sequence numbers provide EOS for open, lock, etc in
+	 * the v4.0 case).
+	 */
+	OP_CACHEME = 1 << 6,
+	/*
+	 * These are ops which clear current state id.
+	 */
+	OP_CLEAR_STATEID = 1 << 7,
+	/* Most ops return only an error on failure; some may do more: */
+	OP_NONTRIVIAL_ERROR_ENCODE = 1 << 8,
+};
+
+struct nfsd4_operation {
+	__be32 (*op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_release)(union nfsd4_op_u *);
+	u32 op_flags;
+	char *op_name;
+	/* Try to get response size before operation */
+	u32 (*op_rsize_bop)(const struct svc_rqst *rqstp,
+			const struct nfsd4_op *op);
+	void (*op_get_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_set_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+};
+
+struct nfsd4_cb_recall_any {
+	struct nfsd4_callback	ra_cb;
+	u32			ra_keep;
+	u32			ra_bmval[1];
+};
+
+#endif
diff --git a/fs/nfsd/xdr4cb.h b/fs/nfsd/xdr4cb.h
new file mode 100644
index 000000000..b06d0170d
--- /dev/null
+++ b/fs/nfsd/xdr4cb.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#define NFS4_MAXTAGLEN		20
+
+#define NFS4_enc_cb_null_sz		0
+#define NFS4_dec_cb_null_sz		0
+#define cb_compound_enc_hdr_sz		4
+#define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
+#define sessionid_sz			(NFS4_MAX_SESSIONID_LEN >> 2)
+#define enc_referring_call4_sz		(1 + 1)
+#define enc_referring_call_list4_sz	(sessionid_sz + 1 + \
+					enc_referring_call4_sz)
+#define cb_sequence_enc_sz		(sessionid_sz + 4 +             \
+					enc_referring_call_list4_sz)
+#define cb_sequence_dec_sz		(op_dec_sz + sessionid_sz + 4)
+
+#define op_enc_sz			1
+#define op_dec_sz			2
+#define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
+#define enc_stateid_sz			(NFS4_STATEID_SIZE >> 2)
+#define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + enc_stateid_sz +            \
+					enc_nfs4_fh_sz)
+
+#define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+#define NFS4_enc_cb_layout_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + 3 +                         \
+					enc_nfs4_fh_sz + 4)
+#define NFS4_dec_cb_layout_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+
+#define NFS4_enc_cb_notify_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + enc_stateid_sz +            \
+					enc_nfs4_fh_sz +		\
+					1 +				\
+					NOTIFY4_EVENT_QUEUE_SIZE *	\
+					(2 + (NFS4_OPAQUE_LIMIT >> 2)))
+
+#define NFS4_dec_cb_notify_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+
+#define NFS4_enc_cb_notify_lock_sz	(cb_compound_enc_hdr_sz +        \
+					cb_sequence_enc_sz +             \
+					2 + 1 +				 \
+					XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+					enc_nfs4_fh_sz)
+#define NFS4_dec_cb_notify_lock_sz	(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+#define enc_cb_offload_info_sz		(1 + 1 + 2 + 1 +		\
+					XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define NFS4_enc_cb_offload_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					enc_nfs4_fh_sz +		\
+					enc_stateid_sz +		\
+					enc_cb_offload_info_sz)
+#define NFS4_dec_cb_offload_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+#define NFS4_enc_cb_recall_any_sz	(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + 1 + 1)
+#define NFS4_dec_cb_recall_any_sz	(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+
+/*
+ * 1: CB_GETATTR opcode (32-bit)
+ * N: file_handle
+ * 1: number of entry in attribute array (32-bit)
+ * 3: entry 0-2 in attribute array (32-bit * 3)
+ */
+#define NFS4_enc_cb_getattr_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + enc_nfs4_fh_sz + 1 + 3)
+/*
+ * 4: fattr_bitmap_maxsz
+ * 1: attribute array len
+ * 2: change attr (64-bit)
+ * 2: size (64-bit)
+ * 2: atime.seconds (64-bit)
+ * 1: atime.nanoseconds (32-bit)
+ * 2: mtime.seconds (64-bit)
+ * 1: mtime.nanoseconds (32-bit)
+ */
+#define NFS4_dec_cb_getattr_sz		(cb_compound_dec_hdr_sz  +      \
+			cb_sequence_dec_sz + 4 + 1 + 2 + 2 + 2 + 1 + 2 + 1 + op_dec_sz)