Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

28 files changed, 10882 insertions, 0 deletions

diff --git a/fs/orangefs/Kconfig b/fs/orangefs/Kconfig
new file mode 100644
index 000000000..890c0ae9a
--- /dev/null
+++ b/fs/orangefs/Kconfig
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ORANGEFS_FS
+	tristate "ORANGEFS (Powered by PVFS) support"
+	select FS_POSIX_ACL
+	help
+	   Orange is a parallel file system designed for use on high end
+	   computing (HEC) systems.
diff --git a/fs/orangefs/Makefile b/fs/orangefs/Makefile
new file mode 100644
index 000000000..9b6c50bb1
--- /dev/null
+++ b/fs/orangefs/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the ORANGEFS filesystem.
+#
+
+obj-$(CONFIG_ORANGEFS_FS) += orangefs.o
+
+orangefs-objs := acl.o file.o orangefs-cache.o orangefs-utils.o xattr.o \
+		 dcache.o inode.o orangefs-sysfs.o orangefs-mod.o super.o \
+		 devorangefs-req.o namei.o symlink.o dir.o orangefs-bufmap.o \
+		 orangefs-debugfs.o waitqueue.o
diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
new file mode 100644
index 000000000..a01ef0c1b
--- /dev/null
+++ b/fs/orangefs/acl.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+#include <linux/posix_acl_xattr.h>
+
+struct posix_acl *orangefs_get_acl(struct inode *inode, int type, bool rcu)
+{
+	struct posix_acl *acl;
+	int ret;
+	char *key = NULL, *value = NULL;
+
+	if (rcu)
+		return ERR_PTR(-ECHILD);
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		key = XATTR_NAME_POSIX_ACL_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		key = XATTR_NAME_POSIX_ACL_DEFAULT;
+		break;
+	default:
+		gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
+		return ERR_PTR(-EINVAL);
+	}
+	/*
+	 * Rather than incurring a network call just to determine the exact
+	 * length of the attribute, I just allocate a max length to save on
+	 * the network call. Conceivably, we could pass NULL to
+	 * orangefs_inode_getxattr() to probe the length of the value, but
+	 * I don't do that for now.
+	 */
+	value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
+	if (!value)
+		return ERR_PTR(-ENOMEM);
+
+	gossip_debug(GOSSIP_ACL_DEBUG,
+		     "inode %pU, key %s, type %d\n",
+		     get_khandle_from_ino(inode),
+		     key,
+		     type);
+	ret = orangefs_inode_getxattr(inode, key, value,
+				      ORANGEFS_MAX_XATTR_VALUELEN);
+	/* if the key exists, convert it to an in-memory rep */
+	if (ret > 0) {
+		acl = posix_acl_from_xattr(&init_user_ns, value, ret);
+	} else if (ret == -ENODATA || ret == -ENOSYS) {
+		acl = NULL;
+	} else {
+		gossip_err("inode %pU retrieving acl's failed with error %d\n",
+			   get_khandle_from_ino(inode),
+			   ret);
+		acl = ERR_PTR(ret);
+	}
+	/* kfree(NULL) is safe, so don't worry if value ever got used */
+	kfree(value);
+	return acl;
+}
+
+int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	int error = 0;
+	void *value = NULL;
+	size_t size = 0;
+	const char *name = NULL;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = XATTR_NAME_POSIX_ACL_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		name = XATTR_NAME_POSIX_ACL_DEFAULT;
+		break;
+	default:
+		gossip_err("%s: invalid type %d!\n", __func__, type);
+		return -EINVAL;
+	}
+
+	gossip_debug(GOSSIP_ACL_DEBUG,
+		     "%s: inode %pU, key %s type %d\n",
+		     __func__, get_khandle_from_ino(inode),
+		     name,
+		     type);
+
+	if (acl) {
+		value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_KERNEL);
+		if (!value)
+			return -ENOMEM;
+	}
+
+	gossip_debug(GOSSIP_ACL_DEBUG,
+		     "%s: name %s, value %p, size %zd, acl %p\n",
+		     __func__, name, value, size, acl);
+	/*
+	 * Go ahead and set the extended attribute now. NOTE: Suppose acl
+	 * was NULL, then value will be NULL and size will be 0 and that
+	 * will xlate to a removexattr. However, we don't want removexattr
+	 * complain if attributes does not exist.
+	 */
+	error = orangefs_inode_setxattr(inode, name, value, size, 0);
+
+	kfree(value);
+	if (!error)
+		set_cached_acl(inode, type, acl);
+	return error;
+}
+
+int orangefs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+		     struct posix_acl *acl, int type)
+{
+	int error;
+	struct iattr iattr;
+	int rc;
+	struct inode *inode = d_inode(dentry);
+
+	memset(&iattr, 0, sizeof iattr);
+
+	if (type == ACL_TYPE_ACCESS && acl) {
+		/*
+		 * posix_acl_update_mode checks to see if the permissions
+		 * described by the ACL can be encoded into the
+		 * object's mode. If so, it sets "acl" to NULL
+		 * and "mode" to the new desired value. It is up to
+		 * us to propagate the new mode back to the server...
+		 */
+		error = posix_acl_update_mode(&nop_mnt_idmap, inode,
+					      &iattr.ia_mode, &acl);
+		if (error) {
+			gossip_err("%s: posix_acl_update_mode err: %d\n",
+				   __func__,
+				   error);
+			return error;
+		}
+
+		if (inode->i_mode != iattr.ia_mode)
+			iattr.ia_valid = ATTR_MODE;
+
+	}
+
+	rc = __orangefs_set_acl(inode, acl, type);
+
+	if (!rc && (iattr.ia_valid == ATTR_MODE))
+		rc = __orangefs_setattr_mode(dentry, &iattr);
+
+	return rc;
+}
diff --git a/fs/orangefs/dcache.c b/fs/orangefs/dcache.c
new file mode 100644
index 000000000..a19d1ad70
--- /dev/null
+++ b/fs/orangefs/dcache.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Implementation of dentry (directory cache) functions.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+
+/* Returns 1 if dentry can still be trusted, else 0. */
+static int orangefs_revalidate_lookup(struct inode *parent_inode, const struct qstr *name,
+				      struct dentry *dentry)
+{
+	struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode);
+	struct inode *inode = dentry->d_inode;
+	struct orangefs_kernel_op_s *new_op;
+	int ret = 0;
+	int err = 0;
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;
+	new_op->upcall.req.lookup.parent_refn = parent->refn;
+	/* op_alloc() leaves ->upcall zeroed */
+	memcpy(new_op->upcall.req.lookup.d_name, name->name,
+			min(name->len, ORANGEFS_NAME_MAX - 1));
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s:%s:%d interrupt flag [%d]\n",
+		     __FILE__,
+		     __func__,
+		     __LINE__,
+		     get_interruptible_flag(parent_inode));
+
+	err = service_operation(new_op, "orangefs_lookup",
+			get_interruptible_flag(parent_inode));
+
+	/* Positive dentry: reject if error or not the same inode. */
+	if (inode) {
+		if (err) {
+			gossip_debug(GOSSIP_DCACHE_DEBUG,
+			    "%s:%s:%d lookup failure.\n",
+			    __FILE__, __func__, __LINE__);
+			goto out_drop;
+		}
+		if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
+		    inode)) {
+			gossip_debug(GOSSIP_DCACHE_DEBUG,
+			    "%s:%s:%d no match.\n",
+			    __FILE__, __func__, __LINE__);
+			goto out_drop;
+		}
+
+	/* Negative dentry: reject if success or error other than ENOENT. */
+	} else {
+		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
+		    __func__);
+		if (!err || err != -ENOENT) {
+			if (new_op->downcall.status != 0)
+				gossip_debug(GOSSIP_DCACHE_DEBUG,
+				    "%s:%s:%d lookup failure.\n",
+				    __FILE__, __func__, __LINE__);
+			goto out_drop;
+		}
+	}
+
+	orangefs_set_timeout(dentry);
+	ret = 1;
+out_release_op:
+	op_release(new_op);
+	return ret;
+out_drop:
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
+	    __FILE__, __func__, __LINE__);
+	goto out_release_op;
+}
+
+/*
+ * Verify that dentry is valid.
+ *
+ * Should return 1 if dentry can still be trusted, else 0.
+ */
+static int orangefs_d_revalidate(struct inode *dir, const struct qstr *name,
+				 struct dentry *dentry, unsigned int flags)
+{
+	int ret;
+	unsigned long time = (unsigned long) dentry->d_fsdata;
+
+	if (time_before(jiffies, time))
+		return 1;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
+		     __func__, dentry);
+
+	/* skip root handle lookups. */
+	if (dentry->d_inode && is_root_handle(dentry->d_inode))
+		return 1;
+
+	/*
+	 * If this passes, the positive dentry still exists or the negative
+	 * dentry still does not exist.
+	 */
+	if (!orangefs_revalidate_lookup(dir, name, dentry))
+		return 0;
+
+	/* We do not need to continue with negative dentries. */
+	if (!dentry->d_inode) {
+		gossip_debug(GOSSIP_DCACHE_DEBUG,
+		    "%s: negative dentry or positive dentry and inode valid.\n",
+		    __func__);
+		return 1;
+	}
+
+	/* Now we must perform a getattr to validate the inode contents. */
+
+	ret = orangefs_inode_check_changed(dentry->d_inode);
+	if (ret < 0) {
+		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
+		    __FILE__, __func__, __LINE__);
+		return 0;
+	}
+	return !ret;
+}
+
+const struct dentry_operations orangefs_dentry_operations = {
+	.d_revalidate = orangefs_d_revalidate,
+};
diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c
new file mode 100644
index 000000000..e5c60da7e
--- /dev/null
+++ b/fs/orangefs/devorangefs-req.c
@@ -0,0 +1,815 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * Changes by Acxiom Corporation to add protocol version to kernel
+ * communication, Copyright Acxiom Corporation, 2005.
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-dev-proto.h"
+#include "orangefs-bufmap.h"
+#include "orangefs-debugfs.h"
+
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+
+/* this file implements the /dev/pvfs2-req device node */
+
+uint32_t orangefs_userspace_version;
+
+static int open_access_count;
+
+static DEFINE_MUTEX(devreq_mutex);
+
+#define DUMP_DEVICE_ERROR()                                                   \
+do {                                                                          \
+	gossip_err("*****************************************************\n");\
+	gossip_err("ORANGEFS Device Error:  You cannot open the device file ");  \
+	gossip_err("\n/dev/%s more than once.  Please make sure that\nthere " \
+		   "are no ", ORANGEFS_REQDEVICE_NAME);                          \
+	gossip_err("instances of a program using this device\ncurrently "     \
+		   "running. (You must verify this!)\n");                     \
+	gossip_err("For example, you can use the lsof program as follows:\n");\
+	gossip_err("'lsof | grep %s' (run this as root)\n",                   \
+		   ORANGEFS_REQDEVICE_NAME);                                     \
+	gossip_err("  open_access_count = %d\n", open_access_count);          \
+	gossip_err("*****************************************************\n");\
+} while (0)
+
+static int hash_func(__u64 tag, int table_size)
+{
+	return do_div(tag, (unsigned int)table_size);
+}
+
+static void orangefs_devreq_add_op(struct orangefs_kernel_op_s *op)
+{
+	int index = hash_func(op->tag, hash_table_size);
+
+	list_add_tail(&op->list, &orangefs_htable_ops_in_progress[index]);
+}
+
+/*
+ * find the op with this tag and remove it from the in progress
+ * hash table.
+ */
+static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag)
+{
+	struct orangefs_kernel_op_s *op, *next;
+	int index;
+
+	index = hash_func(tag, hash_table_size);
+
+	spin_lock(&orangefs_htable_ops_in_progress_lock);
+	list_for_each_entry_safe(op,
+				 next,
+				 &orangefs_htable_ops_in_progress[index],
+				 list) {
+		if (op->tag == tag && !op_state_purged(op) &&
+		    !op_state_given_up(op)) {
+			list_del_init(&op->list);
+			spin_unlock(&orangefs_htable_ops_in_progress_lock);
+			return op;
+		}
+	}
+
+	spin_unlock(&orangefs_htable_ops_in_progress_lock);
+	return NULL;
+}
+
+/* Returns whether any FS are still pending remounted */
+static int mark_all_pending_mounts(void)
+{
+	int unmounted = 1;
+	struct orangefs_sb_info_s *orangefs_sb = NULL;
+
+	spin_lock(&orangefs_superblocks_lock);
+	list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+		/* All of these file system require a remount */
+		orangefs_sb->mount_pending = 1;
+		unmounted = 0;
+	}
+	spin_unlock(&orangefs_superblocks_lock);
+	return unmounted;
+}
+
+/*
+ * Determine if a given file system needs to be remounted or not
+ *  Returns -1 on error
+ *           0 if already mounted
+ *           1 if needs remount
+ */
+static int fs_mount_pending(__s32 fsid)
+{
+	int mount_pending = -1;
+	struct orangefs_sb_info_s *orangefs_sb = NULL;
+
+	spin_lock(&orangefs_superblocks_lock);
+	list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+		if (orangefs_sb->fs_id == fsid) {
+			mount_pending = orangefs_sb->mount_pending;
+			break;
+		}
+	}
+	spin_unlock(&orangefs_superblocks_lock);
+	return mount_pending;
+}
+
+static int orangefs_devreq_open(struct inode *inode, struct file *file)
+{
+	int ret = -EINVAL;
+
+	/* in order to ensure that the filesystem driver sees correct UIDs */
+	if (file->f_cred->user_ns != &init_user_ns) {
+		gossip_err("%s: device cannot be opened outside init_user_ns\n",
+			   __func__);
+		goto out;
+	}
+
+	if (!(file->f_flags & O_NONBLOCK)) {
+		gossip_err("%s: device cannot be opened in blocking mode\n",
+			   __func__);
+		goto out;
+	}
+	ret = -EACCES;
+	gossip_debug(GOSSIP_DEV_DEBUG, "client-core: opening device\n");
+	mutex_lock(&devreq_mutex);
+
+	if (open_access_count == 0) {
+		open_access_count = 1;
+		ret = 0;
+	} else {
+		DUMP_DEVICE_ERROR();
+	}
+	mutex_unlock(&devreq_mutex);
+
+out:
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "pvfs2-client-core: open device complete (ret = %d)\n",
+		     ret);
+	return ret;
+}
+
+/* Function for read() callers into the device */
+static ssize_t orangefs_devreq_read(struct file *file,
+				 char __user *buf,
+				 size_t count, loff_t *offset)
+{
+	struct orangefs_kernel_op_s *op, *temp;
+	__s32 proto_ver = ORANGEFS_KERNEL_PROTO_VERSION;
+	static __s32 magic = ORANGEFS_DEVREQ_MAGIC;
+	struct orangefs_kernel_op_s *cur_op;
+	unsigned long ret;
+
+	/* We do not support blocking IO. */
+	if (!(file->f_flags & O_NONBLOCK)) {
+		gossip_err("%s: blocking read from client-core.\n",
+			   __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * The client will do an ioctl to find MAX_DEV_REQ_UPSIZE, then
+	 * always read with that size buffer.
+	 */
+	if (count != MAX_DEV_REQ_UPSIZE) {
+		gossip_err("orangefs: client-core tried to read wrong size\n");
+		return -EINVAL;
+	}
+
+	/* Check for an empty list before locking. */
+	if (list_empty(&orangefs_request_list))
+		return -EAGAIN;
+
+restart:
+	cur_op = NULL;
+	/* Get next op (if any) from top of list. */
+	spin_lock(&orangefs_request_list_lock);
+	list_for_each_entry_safe(op, temp, &orangefs_request_list, list) {
+		__s32 fsid;
+		/* This lock is held past the end of the loop when we break. */
+		spin_lock(&op->lock);
+		if (unlikely(op_state_purged(op) || op_state_given_up(op))) {
+			spin_unlock(&op->lock);
+			continue;
+		}
+
+		fsid = fsid_of_op(op);
+		if (fsid != ORANGEFS_FS_ID_NULL) {
+			int ret;
+			/* Skip ops whose filesystem needs to be mounted. */
+			ret = fs_mount_pending(fsid);
+			if (ret == 1) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+				    "%s: mount pending, skipping op tag "
+				    "%llu %s\n",
+				    __func__,
+				    llu(op->tag),
+				    get_opname_string(op));
+				spin_unlock(&op->lock);
+				continue;
+			/*
+			 * Skip ops whose filesystem we don't know about unless
+			 * it is being mounted or unmounted.  It is possible for
+			 * a filesystem we don't know about to be unmounted if
+			 * it fails to mount in the kernel after userspace has
+			 * been sent the mount request.
+			 */
+			/* XXX: is there a better way to detect this? */
+			} else if (ret == -1 &&
+				   !(op->upcall.type ==
+					ORANGEFS_VFS_OP_FS_MOUNT ||
+				     op->upcall.type ==
+					ORANGEFS_VFS_OP_GETATTR ||
+				     op->upcall.type ==
+					ORANGEFS_VFS_OP_FS_UMOUNT)) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+				    "orangefs: skipping op tag %llu %s\n",
+				    llu(op->tag), get_opname_string(op));
+				gossip_err(
+				    "orangefs: ERROR: fs_mount_pending %d\n",
+				    fsid);
+				spin_unlock(&op->lock);
+				continue;
+			}
+		}
+		/*
+		 * Either this op does not pertain to a filesystem, is mounting
+		 * a filesystem, or pertains to a mounted filesystem. Let it
+		 * through.
+		 */
+		cur_op = op;
+		break;
+	}
+
+	/*
+	 * At this point we either have a valid op and can continue or have not
+	 * found an op and must ask the client to try again later.
+	 */
+	if (!cur_op) {
+		spin_unlock(&orangefs_request_list_lock);
+		return -EAGAIN;
+	}
+
+	gossip_debug(GOSSIP_DEV_DEBUG, "%s: reading op tag %llu %s\n",
+		     __func__,
+		     llu(cur_op->tag),
+		     get_opname_string(cur_op));
+
+	/*
+	 * Such an op should never be on the list in the first place. If so, we
+	 * will abort.
+	 */
+	if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) {
+		gossip_err("orangefs: ERROR: Current op already queued.\n");
+		list_del_init(&cur_op->list);
+		spin_unlock(&cur_op->lock);
+		spin_unlock(&orangefs_request_list_lock);
+		return -EAGAIN;
+	}
+
+	list_del_init(&cur_op->list);
+	spin_unlock(&orangefs_request_list_lock);
+
+	spin_unlock(&cur_op->lock);
+
+	/* Push the upcall out. */
+	ret = copy_to_user(buf, &proto_ver, sizeof(__s32));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + sizeof(__s32), &magic, sizeof(__s32));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + 2 * sizeof(__s32),
+		&cur_op->tag,
+		sizeof(__u64));
+	if (ret != 0)
+		goto error;
+	ret = copy_to_user(buf + 2 * sizeof(__s32) + sizeof(__u64),
+		&cur_op->upcall,
+		sizeof(struct orangefs_upcall_s));
+	if (ret != 0)
+		goto error;
+
+	spin_lock(&orangefs_htable_ops_in_progress_lock);
+	spin_lock(&cur_op->lock);
+	if (unlikely(op_state_given_up(cur_op))) {
+		spin_unlock(&cur_op->lock);
+		spin_unlock(&orangefs_htable_ops_in_progress_lock);
+		complete(&cur_op->waitq);
+		goto restart;
+	}
+
+	/*
+	 * Set the operation to be in progress and move it between lists since
+	 * it has been sent to the client.
+	 */
+	set_op_state_inprogress(cur_op);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s: 1 op:%s: op_state:%d: process:%s:\n",
+		     __func__,
+		     get_opname_string(cur_op),
+		     cur_op->op_state,
+		     current->comm);
+	orangefs_devreq_add_op(cur_op);
+	spin_unlock(&cur_op->lock);
+	spin_unlock(&orangefs_htable_ops_in_progress_lock);
+
+	/* The client only asks to read one size buffer. */
+	return MAX_DEV_REQ_UPSIZE;
+error:
+	/*
+	 * We were unable to copy the op data to the client. Put the op back in
+	 * list. If client has crashed, the op will be purged later when the
+	 * device is released.
+	 */
+	gossip_err("orangefs: Failed to copy data to user space\n");
+	spin_lock(&orangefs_request_list_lock);
+	spin_lock(&cur_op->lock);
+	if (likely(!op_state_given_up(cur_op))) {
+		set_op_state_waiting(cur_op);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: 2 op:%s: op_state:%d: process:%s:\n",
+			     __func__,
+			     get_opname_string(cur_op),
+			     cur_op->op_state,
+			     current->comm);
+		list_add(&cur_op->list, &orangefs_request_list);
+		spin_unlock(&cur_op->lock);
+	} else {
+		spin_unlock(&cur_op->lock);
+		complete(&cur_op->waitq);
+	}
+	spin_unlock(&orangefs_request_list_lock);
+	return -EFAULT;
+}
+
+/*
+ * Function for writev() callers into the device.
+ *
+ * Userspace should have written:
+ *  - __u32 version
+ *  - __u32 magic
+ *  - __u64 tag
+ *  - struct orangefs_downcall_s
+ *  - trailer buffer (in the case of READDIR operations)
+ */
+static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
+				      struct iov_iter *iter)
+{
+	ssize_t ret;
+	struct orangefs_kernel_op_s *op = NULL;
+	struct {
+		__u32 version;
+		__u32 magic;
+		__u64 tag;
+	} head;
+	int total = ret = iov_iter_count(iter);
+	int downcall_size = sizeof(struct orangefs_downcall_s);
+	int head_size = sizeof(head);
+
+	gossip_debug(GOSSIP_DEV_DEBUG, "%s: total:%d: ret:%zd:\n",
+		     __func__,
+		     total,
+		     ret);
+
+        if (total < MAX_DEV_REQ_DOWNSIZE) {
+		gossip_err("%s: total:%d: must be at least:%u:\n",
+			   __func__,
+			   total,
+			   (unsigned int) MAX_DEV_REQ_DOWNSIZE);
+		return -EFAULT;
+	}
+
+	if (!copy_from_iter_full(&head, head_size, iter)) {
+		gossip_err("%s: failed to copy head.\n", __func__);
+		return -EFAULT;
+	}
+
+	if (head.version < ORANGEFS_MINIMUM_USERSPACE_VERSION) {
+		gossip_err("%s: userspace claims version"
+			   "%d, minimum version required: %d.\n",
+			   __func__,
+			   head.version,
+			   ORANGEFS_MINIMUM_USERSPACE_VERSION);
+		return -EPROTO;
+	}
+
+	if (head.magic != ORANGEFS_DEVREQ_MAGIC) {
+		gossip_err("Error: Device magic number does not match.\n");
+		return -EPROTO;
+	}
+
+	if (!orangefs_userspace_version) {
+		orangefs_userspace_version = head.version;
+	} else if (orangefs_userspace_version != head.version) {
+		gossip_err("Error: userspace version changes\n");
+		return -EPROTO;
+	}
+
+	/* remove the op from the in progress hash table */
+	op = orangefs_devreq_remove_op(head.tag);
+	if (!op) {
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: No one's waiting for tag %llu\n",
+			     __func__, llu(head.tag));
+		return ret;
+	}
+
+	if (!copy_from_iter_full(&op->downcall, downcall_size, iter)) {
+		gossip_err("%s: failed to copy downcall.\n", __func__);
+		goto Efault;
+	}
+
+	if (op->downcall.status)
+		goto wakeup;
+
+	/*
+	 * We've successfully peeled off the head and the downcall.
+	 * Something has gone awry if total doesn't equal the
+	 * sum of head_size, downcall_size and trailer_size.
+	 */
+	if ((head_size + downcall_size + op->downcall.trailer_size) != total) {
+		gossip_err("%s: funky write, head_size:%d"
+			   ": downcall_size:%d: trailer_size:%lld"
+			   ": total size:%d:\n",
+			   __func__,
+			   head_size,
+			   downcall_size,
+			   op->downcall.trailer_size,
+			   total);
+		goto Efault;
+	}
+
+	/* Only READDIR operations should have trailers. */
+	if ((op->downcall.type != ORANGEFS_VFS_OP_READDIR) &&
+	    (op->downcall.trailer_size != 0)) {
+		gossip_err("%s: %x operation with trailer.",
+			   __func__,
+			   op->downcall.type);
+		goto Efault;
+	}
+
+	/* READDIR operations should always have trailers. */
+	if ((op->downcall.type == ORANGEFS_VFS_OP_READDIR) &&
+	    (op->downcall.trailer_size == 0)) {
+		gossip_err("%s: %x operation with no trailer.",
+			   __func__,
+			   op->downcall.type);
+		goto Efault;
+	}
+
+	if (op->downcall.type != ORANGEFS_VFS_OP_READDIR)
+		goto wakeup;
+
+	op->downcall.trailer_buf = vzalloc(op->downcall.trailer_size);
+	if (!op->downcall.trailer_buf)
+		goto Enomem;
+
+	if (!copy_from_iter_full(op->downcall.trailer_buf,
+			         op->downcall.trailer_size, iter)) {
+		gossip_err("%s: failed to copy trailer.\n", __func__);
+		vfree(op->downcall.trailer_buf);
+		op->downcall.trailer_buf = NULL;
+		goto Efault;
+	}
+
+wakeup:
+	/*
+	 * Return to vfs waitqueue, and back to service_operation
+	 * through wait_for_matching_downcall.
+	 */
+	spin_lock(&op->lock);
+	if (unlikely(op_is_cancel(op))) {
+		spin_unlock(&op->lock);
+		put_cancel(op);
+	} else if (unlikely(op_state_given_up(op))) {
+		spin_unlock(&op->lock);
+		complete(&op->waitq);
+	} else {
+		set_op_state_serviced(op);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: op:%s: op_state:%d: process:%s:\n",
+			     __func__,
+			     get_opname_string(op),
+			     op->op_state,
+			     current->comm);
+		spin_unlock(&op->lock);
+	}
+	return ret;
+
+Efault:
+	op->downcall.status = -(ORANGEFS_ERROR_BIT | 9);
+	ret = -EFAULT;
+	goto wakeup;
+
+Enomem:
+	op->downcall.status = -(ORANGEFS_ERROR_BIT | 8);
+	ret = -ENOMEM;
+	goto wakeup;
+}
+
+/*
+ * NOTE: gets called when the last reference to this device is dropped.
+ * Using the open_access_count variable, we enforce a reference count
+ * on this file so that it can be opened by only one process at a time.
+ * the devreq_mutex is used to make sure all i/o has completed
+ * before we call orangefs_bufmap_finalize, and similar such tricky
+ * situations
+ */
+static int orangefs_devreq_release(struct inode *inode, struct file *file)
+{
+	int unmounted = 0;
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s:pvfs2-client-core: exiting, closing device\n",
+		     __func__);
+
+	mutex_lock(&devreq_mutex);
+	orangefs_bufmap_finalize();
+
+	open_access_count = -1;
+
+	unmounted = mark_all_pending_mounts();
+	gossip_debug(GOSSIP_DEV_DEBUG, "ORANGEFS Device Close: Filesystem(s) %s\n",
+		     (unmounted ? "UNMOUNTED" : "MOUNTED"));
+
+	purge_waiting_ops();
+	purge_inprogress_ops();
+
+	orangefs_bufmap_run_down();
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "pvfs2-client-core: device close complete\n");
+	open_access_count = 0;
+	orangefs_userspace_version = 0;
+	mutex_unlock(&devreq_mutex);
+	return 0;
+}
+
+int is_daemon_in_service(void)
+{
+	int in_service;
+
+	/*
+	 * What this function does is checks if client-core is alive
+	 * based on the access count we maintain on the device.
+	 */
+	mutex_lock(&devreq_mutex);
+	in_service = open_access_count == 1 ? 0 : -EIO;
+	mutex_unlock(&devreq_mutex);
+	return in_service;
+}
+
+bool __is_daemon_in_service(void)
+{
+	return open_access_count == 1;
+}
+
+static inline long check_ioctl_command(unsigned int command)
+{
+	/* Check for valid ioctl codes */
+	if (_IOC_TYPE(command) != ORANGEFS_DEV_MAGIC) {
+		gossip_err("device ioctl magic numbers don't match! Did you rebuild pvfs2-client-core/libpvfs2? [cmd %x, magic %x != %x]\n",
+			command,
+			_IOC_TYPE(command),
+			ORANGEFS_DEV_MAGIC);
+		return -EINVAL;
+	}
+	/* and valid ioctl commands */
+	if (_IOC_NR(command) >= ORANGEFS_DEV_MAXNR || _IOC_NR(command) <= 0) {
+		gossip_err("Invalid ioctl command number [%d >= %d]\n",
+			   _IOC_NR(command), ORANGEFS_DEV_MAXNR);
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+static long dispatch_ioctl_command(unsigned int command, unsigned long arg)
+{
+	static __s32 magic = ORANGEFS_DEVREQ_MAGIC;
+	static __s32 max_up_size = MAX_DEV_REQ_UPSIZE;
+	static __s32 max_down_size = MAX_DEV_REQ_DOWNSIZE;
+	struct ORANGEFS_dev_map_desc user_desc;
+	int ret = 0;
+	int upstream_kmod = 1;
+	struct orangefs_sb_info_s *orangefs_sb;
+
+	/* mtmoore: add locking here */
+
+	switch (command) {
+	case ORANGEFS_DEV_GET_MAGIC:
+		return ((put_user(magic, (__s32 __user *) arg) == -EFAULT) ?
+			-EIO :
+			0);
+	case ORANGEFS_DEV_GET_MAX_UPSIZE:
+		return ((put_user(max_up_size,
+				  (__s32 __user *) arg) == -EFAULT) ?
+					-EIO :
+					0);
+	case ORANGEFS_DEV_GET_MAX_DOWNSIZE:
+		return ((put_user(max_down_size,
+				  (__s32 __user *) arg) == -EFAULT) ?
+					-EIO :
+					0);
+	case ORANGEFS_DEV_MAP:
+		ret = copy_from_user(&user_desc,
+				     (struct ORANGEFS_dev_map_desc __user *)
+				     arg,
+				     sizeof(struct ORANGEFS_dev_map_desc));
+		/* WTF -EIO and not -EFAULT? */
+		return ret ? -EIO : orangefs_bufmap_initialize(&user_desc);
+	case ORANGEFS_DEV_REMOUNT_ALL:
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: got ORANGEFS_DEV_REMOUNT_ALL\n",
+			     __func__);
+
+		/*
+		 * remount all mounted orangefs volumes to regain the lost
+		 * dynamic mount tables (if any) -- NOTE: this is done
+		 * without keeping the superblock list locked due to the
+		 * upcall/downcall waiting.  also, the request mutex is
+		 * used to ensure that no operations will be serviced until
+		 * all of the remounts are serviced (to avoid ops between
+		 * mounts to fail)
+		 */
+		ret = mutex_lock_interruptible(&orangefs_request_mutex);
+		if (ret < 0)
+			return ret;
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: priority remount in progress\n",
+			     __func__);
+		spin_lock(&orangefs_superblocks_lock);
+		list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) {
+			/*
+			 * We have to drop the spinlock, so entries can be
+			 * removed.  They can't be freed, though, so we just
+			 * keep the forward pointers and zero the back ones -
+			 * that way we can get to the rest of the list.
+			 */
+			if (!orangefs_sb->list.prev)
+				continue;
+			gossip_debug(GOSSIP_DEV_DEBUG,
+				     "%s: Remounting SB %p\n",
+				     __func__,
+				     orangefs_sb);
+
+			spin_unlock(&orangefs_superblocks_lock);
+			ret = orangefs_remount(orangefs_sb);
+			spin_lock(&orangefs_superblocks_lock);
+			if (ret) {
+				gossip_debug(GOSSIP_DEV_DEBUG,
+					     "SB %p remount failed\n",
+					     orangefs_sb);
+				break;
+			}
+		}
+		spin_unlock(&orangefs_superblocks_lock);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: priority remount complete\n",
+			     __func__);
+		mutex_unlock(&orangefs_request_mutex);
+		return ret;
+
+	case ORANGEFS_DEV_UPSTREAM:
+		ret = copy_to_user((void __user *)arg,
+				    &upstream_kmod,
+				    sizeof(upstream_kmod));
+
+		if (ret != 0)
+			return -EIO;
+		else
+			return ret;
+
+	case ORANGEFS_DEV_CLIENT_MASK:
+		return orangefs_debugfs_new_client_mask((void __user *)arg);
+	case ORANGEFS_DEV_CLIENT_STRING:
+		return orangefs_debugfs_new_client_string((void __user *)arg);
+	case ORANGEFS_DEV_DEBUG:
+		return orangefs_debugfs_new_debug((void __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return -ENOIOCTLCMD;
+}
+
+static long orangefs_devreq_ioctl(struct file *file,
+			       unsigned int command, unsigned long arg)
+{
+	long ret;
+
+	/* Check for properly constructed commands */
+	ret = check_ioctl_command(command);
+	if (ret < 0)
+		return (int)ret;
+
+	return (int)dispatch_ioctl_command(command, arg);
+}
+
+#ifdef CONFIG_COMPAT		/* CONFIG_COMPAT is in .config */
+
+/*  Compat structure for the ORANGEFS_DEV_MAP ioctl */
+struct ORANGEFS_dev_map_desc32 {
+	compat_uptr_t ptr;
+	__s32 total_size;
+	__s32 size;
+	__s32 count;
+};
+
+/*
+ * 32 bit user-space apps' ioctl handlers when kernel modules
+ * is compiled as a 64 bit one
+ */
+static long orangefs_devreq_compat_ioctl(struct file *filp, unsigned int cmd,
+				      unsigned long args)
+{
+	long ret;
+
+	/* Check for properly constructed commands */
+	ret = check_ioctl_command(cmd);
+	if (ret < 0)
+		return ret;
+	if (cmd == ORANGEFS_DEV_MAP) {
+		struct ORANGEFS_dev_map_desc desc;
+		struct ORANGEFS_dev_map_desc32 d32;
+
+		if (copy_from_user(&d32, (void __user *)args, sizeof(d32)))
+			return -EFAULT;
+
+		desc.ptr = compat_ptr(d32.ptr);
+		desc.total_size = d32.total_size;
+		desc.size = d32.size;
+		desc.count = d32.count;
+		return orangefs_bufmap_initialize(&desc);
+	}
+	/* no other ioctl requires translation */
+	return dispatch_ioctl_command(cmd, args);
+}
+
+#endif /* CONFIG_COMPAT is in .config */
+
+static __poll_t orangefs_devreq_poll(struct file *file,
+				      struct poll_table_struct *poll_table)
+{
+	__poll_t poll_revent_mask = 0;
+
+	poll_wait(file, &orangefs_request_list_waitq, poll_table);
+
+	if (!list_empty(&orangefs_request_list))
+		poll_revent_mask |= EPOLLIN;
+	return poll_revent_mask;
+}
+
+/* the assigned character device major number */
+static int orangefs_dev_major;
+
+static const struct file_operations orangefs_devreq_file_operations = {
+	.owner = THIS_MODULE,
+	.read = orangefs_devreq_read,
+	.write_iter = orangefs_devreq_write_iter,
+	.open = orangefs_devreq_open,
+	.release = orangefs_devreq_release,
+	.unlocked_ioctl = orangefs_devreq_ioctl,
+
+#ifdef CONFIG_COMPAT		/* CONFIG_COMPAT is in .config */
+	.compat_ioctl = orangefs_devreq_compat_ioctl,
+#endif
+	.poll = orangefs_devreq_poll
+};
+
+/*
+ * Initialize orangefs device specific state:
+ * Must be called at module load time only
+ */
+int orangefs_dev_init(void)
+{
+	/* register orangefs-req device  */
+	orangefs_dev_major = register_chrdev(0,
+					  ORANGEFS_REQDEVICE_NAME,
+					  &orangefs_devreq_file_operations);
+	if (orangefs_dev_major < 0) {
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "Failed to register /dev/%s (error %d)\n",
+			     ORANGEFS_REQDEVICE_NAME, orangefs_dev_major);
+		return orangefs_dev_major;
+	}
+
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "*** /dev/%s character device registered ***\n",
+		     ORANGEFS_REQDEVICE_NAME);
+	gossip_debug(GOSSIP_DEV_DEBUG, "'mknod /dev/%s c %d 0'.\n",
+		     ORANGEFS_REQDEVICE_NAME, orangefs_dev_major);
+	return 0;
+}
+
+void orangefs_dev_cleanup(void)
+{
+	unregister_chrdev(orangefs_dev_major, ORANGEFS_REQDEVICE_NAME);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "*** /dev/%s character device unregistered ***\n",
+		     ORANGEFS_REQDEVICE_NAME);
+}
diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
new file mode 100644
index 000000000..115b2c2f5
--- /dev/null
+++ b/fs/orangefs/dir.c
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2017 Omnibond Systems, L.L.C.
+ */
+
+#include <linux/filelock.h>
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+struct orangefs_dir_part {
+	struct orangefs_dir_part *next;
+	size_t len;
+};
+
+struct orangefs_dir {
+	__u64 token;
+	struct orangefs_dir_part *part;
+	loff_t end;
+	int error;
+};
+
+#define PART_SHIFT (24)
+#define PART_SIZE (1<<24)
+#define PART_MASK (~(PART_SIZE - 1))
+
+/*
+ * There can be up to 512 directory entries.  Each entry is encoded as
+ * follows:
+ * 4 bytes: string size (n)
+ * n bytes: string
+ * 1 byte: trailing zero
+ * padding to 8 bytes
+ * 16 bytes: khandle
+ * padding to 8 bytes
+ *
+ * The trailer_buf starts with a struct orangefs_readdir_response_s
+ * which must be skipped to get to the directory data.
+ *
+ * The data which is received from the userspace daemon is termed a
+ * part and is stored in a linked list in case more than one part is
+ * needed for a large directory.
+ *
+ * The position pointer (ctx->pos) encodes the part and offset on which
+ * to begin reading at.  Bits above PART_SHIFT encode the part and bits
+ * below PART_SHIFT encode the offset.  Parts are stored in a linked
+ * list which grows as data is received from the server.  The overhead
+ * associated with managing the list is presumed to be small compared to
+ * the overhead of communicating with the server.
+ *
+ * As data is received from the server, it is placed at the end of the
+ * part list.  Data is parsed from the current position as it is needed.
+ * When data is determined to be corrupt, it is either because the
+ * userspace component has sent back corrupt data or because the file
+ * pointer has been moved to an invalid location.  Since the two cannot
+ * be differentiated, return EIO.
+ *
+ * Part zero is synthesized to contains `.' and `..'.  Part one is the
+ * first part of the part list.
+ */
+
+static int do_readdir(struct orangefs_dir *od, struct inode *inode,
+    struct orangefs_kernel_op_s *op)
+{
+	struct orangefs_inode_s *oi = ORANGEFS_I(inode);
+	struct orangefs_readdir_response_s *resp;
+	int bufi, r;
+
+	/*
+	 * Despite the badly named field, readdir does not use shared
+	 * memory.  However, there are a limited number of readdir
+	 * slots, which must be allocated here.  This flag simply tells
+	 * the op scheduler to return the op here for retry.
+	 */
+	op->uses_shared_memory = 1;
+	op->upcall.req.readdir.refn = oi->refn;
+	op->upcall.req.readdir.token = od->token;
+	op->upcall.req.readdir.max_dirent_count =
+	    ORANGEFS_MAX_DIRENT_COUNT_READDIR;
+
+again:
+	bufi = orangefs_readdir_index_get();
+	if (bufi < 0) {
+		od->error = bufi;
+		return bufi;
+	}
+
+	op->upcall.req.readdir.buf_index = bufi;
+
+	r = service_operation(op, "orangefs_readdir",
+	    get_interruptible_flag(inode));
+
+	orangefs_readdir_index_put(bufi);
+
+	if (op_state_purged(op)) {
+		if (r == -EAGAIN) {
+			vfree(op->downcall.trailer_buf);
+			goto again;
+		} else if (r == -EIO) {
+			vfree(op->downcall.trailer_buf);
+			od->error = r;
+			return r;
+		}
+	}
+
+	if (r < 0) {
+		vfree(op->downcall.trailer_buf);
+		od->error = r;
+		return r;
+	} else if (op->downcall.status) {
+		vfree(op->downcall.trailer_buf);
+		od->error = op->downcall.status;
+		return op->downcall.status;
+	}
+
+	/*
+	 * The maximum size is size per entry times the 512 entries plus
+	 * the header.  This is well under the limit.
+	 */
+	if (op->downcall.trailer_size > PART_SIZE) {
+		vfree(op->downcall.trailer_buf);
+		od->error = -EIO;
+		return -EIO;
+	}
+
+	resp = (struct orangefs_readdir_response_s *)
+	    op->downcall.trailer_buf;
+	od->token = resp->token;
+	return 0;
+}
+
+static int parse_readdir(struct orangefs_dir *od,
+    struct orangefs_kernel_op_s *op)
+{
+	struct orangefs_dir_part *part, *new;
+	size_t count;
+
+	count = 1;
+	part = od->part;
+	while (part) {
+		count++;
+		if (part->next)
+			part = part->next;
+		else
+			break;
+	}
+
+	new = (void *)op->downcall.trailer_buf;
+	new->next = NULL;
+	new->len = op->downcall.trailer_size -
+	    sizeof(struct orangefs_readdir_response_s);
+	if (!od->part)
+		od->part = new;
+	else
+		part->next = new;
+	count++;
+	od->end = count << PART_SHIFT;
+
+	return 0;
+}
+
+static int orangefs_dir_more(struct orangefs_dir *od, struct inode *inode)
+{
+	struct orangefs_kernel_op_s *op;
+	int r;
+
+	op = op_alloc(ORANGEFS_VFS_OP_READDIR);
+	if (!op) {
+		od->error = -ENOMEM;
+		return -ENOMEM;
+	}
+	r = do_readdir(od, inode, op);
+	if (r) {
+		od->error = r;
+		goto out;
+	}
+	r = parse_readdir(od, op);
+	if (r) {
+		od->error = r;
+		goto out;
+	}
+
+	od->error = 0;
+out:
+	op_release(op);
+	return od->error;
+}
+
+static int fill_from_part(struct orangefs_dir_part *part,
+    struct dir_context *ctx)
+{
+	const int offset = sizeof(struct orangefs_readdir_response_s);
+	struct orangefs_khandle *khandle;
+	__u32 *len;
+	u64 padlen;
+	loff_t i;
+	char *s;
+	i = ctx->pos & ~PART_MASK;
+
+	/* The file offset from userspace is too large. */
+	if (i > part->len)
+		return 1;
+
+	/*
+	 * If the seek pointer is positioned just before an entry it
+	 * should find the next entry.
+	 */
+	if (i % 8)
+		i = i + (8 - i%8)%8;
+
+	while (i < part->len) {
+		if (part->len < i + sizeof *len)
+			break;
+		len = (void *)part + offset + i;
+		/*
+		 * len is the size of the string itself.  padlen is the
+		 * total size of the encoded string.
+		 */
+		padlen = (u64)sizeof *len + *len + 1;
+		padlen += (8 - padlen % 8) % 8;
+		if (part->len < i + padlen + sizeof *khandle)
+			goto next;
+		s = (void *)part + offset + i + sizeof *len;
+		if (s[*len] != 0)
+			goto next;
+		khandle = (void *)part + offset + i + padlen;
+		if (!dir_emit(ctx, s, *len,
+		    orangefs_khandle_to_ino(khandle),
+		    DT_UNKNOWN))
+			return 0;
+		i += padlen + sizeof *khandle;
+		i = i + (8 - i%8)%8;
+		BUG_ON(i > part->len);
+		ctx->pos = (ctx->pos & PART_MASK) | i;
+		continue;
+next:
+		i += 8;
+	}
+	return 1;
+}
+
+static int orangefs_dir_fill(struct orangefs_dir *od, struct dir_context *ctx)
+{
+	struct orangefs_dir_part *part;
+	size_t count;
+
+	count = ((ctx->pos & PART_MASK) >> PART_SHIFT) - 1;
+
+	part = od->part;
+	while (part->next && count) {
+		count--;
+		part = part->next;
+	}
+	/* This means the userspace file offset is invalid. */
+	if (count) {
+		od->error = -EIO;
+		return -EIO;
+	}
+
+	while (part && part->len) {
+		int r;
+		r = fill_from_part(part, ctx);
+		if (r < 0) {
+			od->error = r;
+			return r;
+		} else if (r == 0) {
+			/* Userspace buffer is full. */
+			break;
+		} else {
+			/*
+			 * The part ran out of data.  Move to the next
+			 * part. */
+			ctx->pos = (ctx->pos & PART_MASK) +
+			    (1 << PART_SHIFT);
+			part = part->next;
+		}
+	}
+	return 0;
+}
+
+static loff_t orangefs_dir_llseek(struct file *file, loff_t offset,
+    int whence)
+{
+	struct orangefs_dir *od = file->private_data;
+	/*
+	 * Delete the stored data so userspace sees new directory
+	 * entries.
+	 */
+	if (!whence && offset < od->end) {
+		struct orangefs_dir_part *part = od->part;
+		while (part) {
+			struct orangefs_dir_part *next = part->next;
+			vfree(part);
+			part = next;
+		}
+		od->token = ORANGEFS_ITERATE_START;
+		od->part = NULL;
+		od->end = 1 << PART_SHIFT;
+	}
+	return default_llseek(file, offset, whence);
+}
+
+static int orangefs_dir_iterate(struct file *file,
+    struct dir_context *ctx)
+{
+	struct orangefs_dir *od = file->private_data;
+	struct inode *inode = file_inode(file);
+	int r;
+
+	if (od->error)
+		return od->error;
+
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(file, ctx))
+			return 0;
+		ctx->pos++;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit_dotdot(file, ctx))
+			return 0;
+		ctx->pos = 1 << PART_SHIFT;
+	}
+
+	/*
+	 * The seek position is in the first synthesized part but is not
+	 * valid.
+	 */
+	if ((ctx->pos & PART_MASK) == 0)
+		return -EIO;
+
+	r = 0;
+
+	/*
+	 * Must read more if the user has sought past what has been read
+	 * so far.  Stop a user who has sought past the end.
+	 */
+	while (od->token != ORANGEFS_ITERATE_END &&
+	    ctx->pos > od->end) {
+		r = orangefs_dir_more(od, inode);
+		if (r)
+			return r;
+	}
+	if (od->token == ORANGEFS_ITERATE_END && ctx->pos > od->end)
+		return -EIO;
+
+	/* Then try to fill if there's any left in the buffer. */
+	if (ctx->pos < od->end) {
+		r = orangefs_dir_fill(od, ctx);
+		if (r)
+			return r;
+	}
+
+	/* Finally get some more and try to fill. */
+	if (od->token != ORANGEFS_ITERATE_END) {
+		r = orangefs_dir_more(od, inode);
+		if (r)
+			return r;
+		r = orangefs_dir_fill(od, ctx);
+	}
+
+	return r;
+}
+
+static int orangefs_dir_open(struct inode *inode, struct file *file)
+{
+	struct orangefs_dir *od;
+	file->private_data = kmalloc_obj(struct orangefs_dir);
+	if (!file->private_data)
+		return -ENOMEM;
+	od = file->private_data;
+	od->token = ORANGEFS_ITERATE_START;
+	od->part = NULL;
+	od->end = 1 << PART_SHIFT;
+	od->error = 0;
+	return 0;
+}
+
+static int orangefs_dir_release(struct inode *inode, struct file *file)
+{
+	struct orangefs_dir *od = file->private_data;
+	struct orangefs_dir_part *part = od->part;
+	while (part) {
+		struct orangefs_dir_part *next = part->next;
+		vfree(part);
+		part = next;
+	}
+	kfree(od);
+	return 0;
+}
+
+const struct file_operations orangefs_dir_operations = {
+	.llseek = orangefs_dir_llseek,
+	.read = generic_read_dir,
+	.iterate_shared = orangefs_dir_iterate,
+	.open = orangefs_dir_open,
+	.release = orangefs_dir_release,
+	.setlease = generic_setlease,
+};
diff --git a/fs/orangefs/downcall.h b/fs/orangefs/downcall.h
new file mode 100644
index 000000000..ea2332e16
--- /dev/null
+++ b/fs/orangefs/downcall.h
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Definitions of downcalls used in Linux kernel module.
+ */
+
+#ifndef __DOWNCALL_H
+#define __DOWNCALL_H
+
+/*
+ * Sanitized the device-client core interaction
+ * for clean 32-64 bit usage
+ */
+struct orangefs_io_response {
+	__s64 amt_complete;
+};
+
+struct orangefs_lookup_response {
+	struct orangefs_object_kref refn;
+};
+
+struct orangefs_create_response {
+	struct orangefs_object_kref refn;
+};
+
+struct orangefs_symlink_response {
+	struct orangefs_object_kref refn;
+};
+
+struct orangefs_getattr_response {
+	struct ORANGEFS_sys_attr_s attributes;
+	char link_target[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_mkdir_response {
+	struct orangefs_object_kref refn;
+};
+
+struct orangefs_statfs_response {
+	__s64 block_size;
+	__s64 blocks_total;
+	__s64 blocks_avail;
+	__s64 files_total;
+	__s64 files_avail;
+};
+
+struct orangefs_fs_mount_response {
+	__s32 fs_id;
+	__s32 id;
+	struct orangefs_khandle root_khandle;
+};
+
+/* the getxattr response is the attribute value */
+struct orangefs_getxattr_response {
+	__s32 val_sz;
+	__s32 __pad1;
+	char val[ORANGEFS_MAX_XATTR_VALUELEN];
+};
+
+/* the listxattr response is an array of attribute names */
+struct orangefs_listxattr_response {
+	__s32 returned_count;
+	__s32 __pad1;
+	__u64 token;
+	char key[ORANGEFS_MAX_XATTR_LISTLEN * ORANGEFS_MAX_XATTR_NAMELEN];
+	__s32 keylen;
+	__s32 __pad2;
+	__s32 lengths[ORANGEFS_MAX_XATTR_LISTLEN];
+};
+
+struct orangefs_param_response {
+	union {
+		__s64 value64;
+		__s32 value32[2];
+	} u;
+};
+
+#define PERF_COUNT_BUF_SIZE 4096
+struct orangefs_perf_count_response {
+	char buffer[PERF_COUNT_BUF_SIZE];
+};
+
+#define FS_KEY_BUF_SIZE 4096
+struct orangefs_fs_key_response {
+	__s32 fs_keylen;
+	__s32 __pad1;
+	char fs_key[FS_KEY_BUF_SIZE];
+};
+
+/* 2.9.6 */
+struct orangefs_features_response {
+	__u64 features;
+};
+
+struct orangefs_downcall_s {
+	__s32 type;
+	__s32 status;
+	/* currently trailer is used only by readdir */
+	__s64 trailer_size;
+	char *trailer_buf;
+
+	union {
+		struct orangefs_io_response io;
+		struct orangefs_lookup_response lookup;
+		struct orangefs_create_response create;
+		struct orangefs_symlink_response sym;
+		struct orangefs_getattr_response getattr;
+		struct orangefs_mkdir_response mkdir;
+		struct orangefs_statfs_response statfs;
+		struct orangefs_fs_mount_response fs_mount;
+		struct orangefs_getxattr_response getxattr;
+		struct orangefs_listxattr_response listxattr;
+		struct orangefs_param_response param;
+		struct orangefs_perf_count_response perf_count;
+		struct orangefs_fs_key_response fs_key;
+		struct orangefs_features_response features;
+	} resp;
+};
+
+/*
+ * The readdir response comes in the trailer.  It is followed by the
+ * directory entries as described in dir.c.
+ */
+
+struct orangefs_readdir_response_s {
+	__u64 token;
+	__u64 directory_version;
+	__u32 __pad2;
+	__u32 orangefs_dirent_outcount;
+};
+
+#endif /* __DOWNCALL_H */
diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
new file mode 100644
index 000000000..42591252e
--- /dev/null
+++ b/fs/orangefs/file.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * Copyright 2018 Omnibond Systems, L.L.C.
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS file operations.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/pagemap.h>
+
+static int flush_racache(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int ret;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG,
+	    "%s: %pU: Handle is %pU | fs_id %d\n", __func__,
+	    get_khandle_from_ino(inode), &orangefs_inode->refn.khandle,
+	    orangefs_inode->refn.fs_id);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_RA_FLUSH);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.ra_cache_flush.refn = orangefs_inode->refn;
+
+	ret = service_operation(new_op, "orangefs_flush_racache",
+	    get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: got return value of %d\n",
+	    __func__, ret);
+
+	op_release(new_op);
+	return ret;
+}
+
+/*
+ * Post and wait for the I/O upcall to finish
+ */
+ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inode,
+	loff_t *offset, struct iov_iter *iter, size_t total_size,
+	loff_t readahead_size, struct orangefs_write_range *wr,
+	int *index_return, struct file *file)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_khandle *handle = &orangefs_inode->refn.khandle;
+	struct orangefs_kernel_op_s *new_op = NULL;
+	int buffer_index;
+	ssize_t ret;
+	size_t copy_amount;
+	bool open_for_read;
+	bool open_for_write;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FILE_IO);
+	if (!new_op)
+		return -ENOMEM;
+
+	/* synchronous I/O */
+	new_op->upcall.req.io.readahead_size = readahead_size;
+	new_op->upcall.req.io.io_type = type;
+	new_op->upcall.req.io.refn = orangefs_inode->refn;
+
+populate_shared_memory:
+	/* get a shared buffer index */
+	buffer_index = orangefs_bufmap_get();
+	if (buffer_index < 0) {
+		ret = buffer_index;
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s: orangefs_bufmap_get failure (%zd)\n",
+			     __func__, ret);
+		goto out;
+	}
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): GET op %p -> buffer_index %d\n",
+		     __func__,
+		     handle,
+		     new_op,
+		     buffer_index);
+
+	new_op->uses_shared_memory = 1;
+	new_op->upcall.req.io.buf_index = buffer_index;
+	new_op->upcall.req.io.count = total_size;
+	new_op->upcall.req.io.offset = *offset;
+	if (type == ORANGEFS_IO_WRITE && wr) {
+		new_op->upcall.uid = from_kuid(&init_user_ns, wr->uid);
+		new_op->upcall.gid = from_kgid(&init_user_ns, wr->gid);
+	}
+	/*
+	 * Orangefs has no open, and orangefs checks file permissions
+	 * on each file access. Posix requires that file permissions
+	 * be checked on open and nowhere else. Orangefs-through-the-kernel
+	 * needs to seem posix compliant.
+	 *
+	 * The VFS opens files, even if the filesystem provides no
+	 * method. We can see if a file was successfully opened for
+	 * read and or for write by looking at file->f_mode.
+	 *
+	 * When writes are flowing from the page cache, file is no
+	 * longer available. We can trust the VFS to have checked
+	 * file->f_mode before writing to the page cache.
+	 *
+	 * The mode of a file might change between when it is opened
+	 * and IO commences, or it might be created with an arbitrary mode.
+	 *
+	 * We'll make sure we don't hit EACCES during the IO stage by
+	 * using UID 0. Some of the time we have access without changing
+	 * to UID 0 - how to check?
+	 */
+	if (file) {
+		open_for_write = file->f_mode & FMODE_WRITE;
+		open_for_read = file->f_mode & FMODE_READ;
+	} else {
+		open_for_write = 1;
+		open_for_read = 0; /* not relevant? */
+	}
+	if ((type == ORANGEFS_IO_WRITE) && open_for_write)
+		new_op->upcall.uid = 0;
+	if ((type == ORANGEFS_IO_READ) && open_for_read)
+		new_op->upcall.uid = 0;
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): offset: %llu total_size: %zd\n",
+		     __func__,
+		     handle,
+		     llu(*offset),
+		     total_size);
+	/*
+	 * Stage 1: copy the buffers into client-core's address space
+	 */
+	if (type == ORANGEFS_IO_WRITE && total_size) {
+		ret = orangefs_bufmap_copy_from_iovec(iter, buffer_index,
+		    total_size);
+		if (ret < 0) {
+			gossip_err("%s: Failed to copy-in buffers. Please make sure that the pvfs2-client is running. %ld\n",
+			    __func__, (long)ret);
+			goto out;
+		}
+	}
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): Calling post_io_request with tag (%llu)\n",
+		     __func__,
+		     handle,
+		     llu(new_op->tag));
+
+	/* Stage 2: Service the I/O operation */
+	ret = service_operation(new_op,
+				type == ORANGEFS_IO_WRITE ?
+					"file_write" :
+					"file_read",
+				get_interruptible_flag(inode));
+
+	/*
+	 * If service_operation() returns -EAGAIN #and# the operation was
+	 * purged from orangefs_request_list or htable_ops_in_progress, then
+	 * we know that the client was restarted, causing the shared memory
+	 * area to be wiped clean.  To restart a  write operation in this
+	 * case, we must re-copy the data from the user's iovec to a NEW
+	 * shared memory location. To restart a read operation, we must get
+	 * a new shared memory location.
+	 */
+	if (ret == -EAGAIN && op_state_purged(new_op)) {
+		orangefs_bufmap_put(buffer_index);
+		if (type == ORANGEFS_IO_WRITE)
+			iov_iter_revert(iter, total_size);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s:going to repopulate_shared_memory.\n",
+			     __func__);
+		goto populate_shared_memory;
+	}
+
+	if (ret < 0) {
+		if (ret == -EINTR) {
+			/*
+			 * We can't return EINTR if any data was written,
+			 * it's not POSIX. It is minimally acceptable
+			 * to give a partial write, the way NFS does.
+			 *
+			 * It would be optimal to return all or nothing,
+			 * but if a userspace write is bigger than
+			 * an IO buffer, and the interrupt occurs
+			 * between buffer writes, that would not be
+			 * possible.
+			 */
+			switch (new_op->op_state - OP_VFS_STATE_GIVEN_UP) {
+			/*
+			 * If the op was waiting when the interrupt
+			 * occurred, then the client-core did not
+			 * trigger the write.
+			 */
+			case OP_VFS_STATE_WAITING:
+				if (*offset == 0)
+					ret = -EINTR;
+				else
+					ret = 0;
+				break;
+			/*
+			 * If the op was in progress when the interrupt
+			 * occurred, then the client-core was able to
+			 * trigger the write.
+			 */
+			case OP_VFS_STATE_INPROGR:
+				if (type == ORANGEFS_IO_READ)
+					ret = -EINTR;
+				else
+					ret = total_size;
+				break;
+			default:
+				gossip_err("%s: unexpected op state :%d:.\n",
+					   __func__,
+					   new_op->op_state);
+				ret = 0;
+				break;
+			}
+			gossip_debug(GOSSIP_FILE_DEBUG,
+				     "%s: got EINTR, state:%d: %p\n",
+				     __func__,
+				     new_op->op_state,
+				     new_op);
+		} else {
+			gossip_err("%s: error in %s handle %pU, returning %zd\n",
+				__func__,
+				type == ORANGEFS_IO_READ ?
+					"read from" : "write to",
+				handle, ret);
+		}
+		if (orangefs_cancel_op_in_progress(new_op))
+			return ret;
+
+		goto out;
+	}
+
+	/*
+	 * Stage 3: Post copy buffers from client-core's address space
+	 */
+	if (type == ORANGEFS_IO_READ && new_op->downcall.resp.io.amt_complete) {
+		/*
+		 * NOTE: the iovector can either contain addresses which
+		 *       can futher be kernel-space or user-space addresses.
+		 *       or it can pointers to struct page's
+		 */
+
+		copy_amount = new_op->downcall.resp.io.amt_complete;
+
+		ret = orangefs_bufmap_copy_to_iovec(iter, buffer_index,
+			copy_amount);
+		if (ret < 0) {
+			gossip_err("%s: Failed to copy-out buffers. Please make sure that the pvfs2-client is running (%ld)\n",
+			    __func__, (long)ret);
+			goto out;
+		}
+	}
+	gossip_debug(GOSSIP_FILE_DEBUG,
+	    "%s(%pU): Amount %s, returned by the sys-io call:%d\n",
+	    __func__,
+	    handle,
+	    type == ORANGEFS_IO_READ ?  "read" : "written",
+	    (int)new_op->downcall.resp.io.amt_complete);
+
+	ret = new_op->downcall.resp.io.amt_complete;
+
+out:
+	if (buffer_index >= 0) {
+		orangefs_bufmap_put(buffer_index);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			"%s(%pU): PUT buffer_index %d\n",
+			__func__, handle, buffer_index);
+	}
+	op_release(new_op);
+	return ret;
+}
+
+int orangefs_revalidate_mapping(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct address_space *mapping = inode->i_mapping;
+	unsigned long *bitlock = &orangefs_inode->bitlock;
+	int ret;
+
+	while (1) {
+		ret = wait_on_bit(bitlock, 1, TASK_KILLABLE);
+		if (ret)
+			return ret;
+		spin_lock(&inode->i_lock);
+		if (test_bit(1, bitlock)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		if (!time_before(jiffies, orangefs_inode->mapping_time))
+			break;
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+
+	set_bit(1, bitlock);
+	smp_wmb();
+	spin_unlock(&inode->i_lock);
+
+	unmap_mapping_range(mapping, 0, 0, 0);
+	ret = filemap_write_and_wait(mapping);
+	if (!ret)
+		ret = invalidate_inode_pages2(mapping);
+
+	orangefs_inode->mapping_time = jiffies +
+	    orangefs_cache_timeout_msecs*HZ/1000;
+
+	clear_bit(1, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, 1);
+
+	return ret;
+}
+
+static ssize_t orangefs_file_read_iter(struct kiocb *iocb,
+    struct iov_iter *iter)
+{
+	int ret;
+	orangefs_stats.reads++;
+
+	down_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+	if (ret)
+		goto out;
+
+	ret = generic_file_read_iter(iocb, iter);
+out:
+	up_read(&file_inode(iocb->ki_filp)->i_rwsem);
+	return ret;
+}
+
+static ssize_t orangefs_file_splice_read(struct file *in, loff_t *ppos,
+					 struct pipe_inode_info *pipe,
+					 size_t len, unsigned int flags)
+{
+	struct inode *inode = file_inode(in);
+	ssize_t ret;
+
+	orangefs_stats.reads++;
+
+	down_read(&inode->i_rwsem);
+	ret = orangefs_revalidate_mapping(inode);
+	if (ret)
+		goto out;
+
+	ret = filemap_splice_read(in, ppos, pipe, len, flags);
+out:
+	up_read(&inode->i_rwsem);
+	return ret;
+}
+
+static ssize_t orangefs_file_write_iter(struct kiocb *iocb,
+    struct iov_iter *iter)
+{
+	int ret;
+	orangefs_stats.writes++;
+
+	if (iocb->ki_pos > i_size_read(file_inode(iocb->ki_filp))) {
+		ret = orangefs_revalidate_mapping(file_inode(iocb->ki_filp));
+		if (ret)
+			return ret;
+	}
+
+	ret = generic_file_write_iter(iocb, iter);
+	return ret;
+}
+
+static vm_fault_t orangefs_fault(struct vm_fault *vmf)
+{
+	struct file *file = vmf->vma->vm_file;
+	int ret;
+	ret = orangefs_inode_getattr(file->f_mapping->host,
+	    ORANGEFS_GETATTR_SIZE);
+	if (ret == -ESTALE)
+		ret = -EIO;
+	if (ret) {
+		gossip_err("%s: orangefs_inode_getattr failed, "
+		    "ret:%d:.\n", __func__, ret);
+		return VM_FAULT_SIGBUS;
+	}
+	return filemap_fault(vmf);
+}
+
+static const struct vm_operations_struct orangefs_file_vm_ops = {
+	.fault = orangefs_fault,
+	.map_pages = filemap_map_pages,
+	.page_mkwrite = orangefs_page_mkwrite,
+};
+
+/*
+ * Memory map a region of a file.
+ */
+static int orangefs_file_mmap_prepare(struct vm_area_desc *desc)
+{
+	struct file *file = desc->file;
+	int ret;
+
+	ret = orangefs_revalidate_mapping(file_inode(file));
+	if (ret)
+		return ret;
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_mmap: called on %pD\n", file);
+
+	/* set the sequential readahead hint */
+	vma_desc_set_flags(desc, VMA_SEQ_READ_BIT);
+	vma_desc_clear_flags(desc, VMA_RAND_READ_BIT);
+
+	file_accessed(file);
+	desc->vm_ops = &orangefs_file_vm_ops;
+	return 0;
+}
+
+#define mapping_nrpages(idata) ((idata)->nrpages)
+
+/*
+ * Called to notify the module that there are no more references to
+ * this file (i.e. no processes have it open).
+ *
+ * \note Not called when each file is closed.
+ */
+static int orangefs_file_release(struct inode *inode, struct file *file)
+{
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_release: called on %pD\n",
+		     file);
+
+	/*
+	 * remove all associated inode pages from the page cache and
+	 * readahead cache (if any); this forces an expensive refresh of
+	 * data for the next caller of mmap (or 'get_block' accesses)
+	 */
+	if (mapping_nrpages(file->f_mapping)) {
+		if (orangefs_features & ORANGEFS_FEATURE_READAHEAD) {
+			gossip_debug(GOSSIP_INODE_DEBUG,
+			    "calling flush_racache on %pU\n",
+			    get_khandle_from_ino(inode));
+			flush_racache(inode);
+			gossip_debug(GOSSIP_INODE_DEBUG,
+			    "flush_racache finished\n");
+		}
+
+	}
+	return 0;
+}
+
+/*
+ * Push all data for a specific file onto permanent storage.
+ */
+static int orangefs_fsync(struct file *file,
+		       loff_t start,
+		       loff_t end,
+		       int datasync)
+{
+	int ret;
+	struct orangefs_inode_s *orangefs_inode =
+		ORANGEFS_I(file_inode(file));
+	struct orangefs_kernel_op_s *new_op = NULL;
+
+	ret = filemap_write_and_wait_range(file_inode(file)->i_mapping,
+	    start, end);
+	if (ret < 0)
+		return ret;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FSYNC);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.fsync.refn = orangefs_inode->refn;
+
+	ret = service_operation(new_op,
+			"orangefs_fsync",
+			get_interruptible_flag(file_inode(file)));
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_fsync got return value of %d\n",
+		     ret);
+
+	op_release(new_op);
+	return ret;
+}
+
+/*
+ * Change the file pointer position for an instance of an open file.
+ *
+ * \note If .llseek is overriden, we must acquire lock as described in
+ *       Documentation/filesystems/locking.rst.
+ *
+ * Future upgrade could support SEEK_DATA and SEEK_HOLE but would
+ * require much changes to the FS
+ */
+static loff_t orangefs_file_llseek(struct file *file, loff_t offset, int origin)
+{
+	int ret = -EINVAL;
+	struct inode *inode = file_inode(file);
+
+	if (origin == SEEK_END) {
+		/*
+		 * revalidate the inode's file size.
+		 * NOTE: We are only interested in file size here,
+		 * so we set mask accordingly.
+		 */
+		ret = orangefs_inode_getattr(file->f_mapping->host,
+		    ORANGEFS_GETATTR_SIZE);
+		if (ret == -ESTALE)
+			ret = -EIO;
+		if (ret) {
+			gossip_debug(GOSSIP_FILE_DEBUG,
+				     "%s:%s:%d calling make bad inode\n",
+				     __FILE__,
+				     __func__,
+				     __LINE__);
+			return ret;
+		}
+	}
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "orangefs_file_llseek: offset is %ld | origin is %d"
+		     " | inode size is %lu\n",
+		     (long)offset,
+		     origin,
+		     (unsigned long)i_size_read(inode));
+
+	return generic_file_llseek(file, offset, origin);
+}
+
+/*
+ * Support local locks (locks that only this kernel knows about)
+ * if Orangefs was mounted -o local_lock.
+ */
+static int orangefs_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	int rc = -EINVAL;
+
+	if (ORANGEFS_SB(file_inode(filp)->i_sb)->flags & ORANGEFS_OPT_LOCAL_LOCK) {
+		if (cmd == F_GETLK) {
+			rc = 0;
+			posix_test_lock(filp, fl);
+		} else {
+			rc = posix_lock_file(filp, fl, NULL);
+		}
+	}
+
+	return rc;
+}
+
+static int orangefs_flush(struct file *file, fl_owner_t id)
+{
+	/*
+	 * This is vfs_fsync_range(file, 0, LLONG_MAX, 0) without the
+	 * service_operation in orangefs_fsync.
+	 *
+	 * Do not send fsync to OrangeFS server on a close.  Do send fsync
+	 * on an explicit fsync call.  This duplicates historical OrangeFS
+	 * behavior.
+	 */
+	int r;
+
+	r = filemap_write_and_wait_range(file->f_mapping, 0, LLONG_MAX);
+	if (r > 0)
+		return 0;
+	else
+		return r;
+}
+
+/** ORANGEFS implementation of VFS file operations */
+const struct file_operations orangefs_file_operations = {
+	.llseek		= orangefs_file_llseek,
+	.read_iter	= orangefs_file_read_iter,
+	.write_iter	= orangefs_file_write_iter,
+	.lock		= orangefs_lock,
+	.mmap_prepare	= orangefs_file_mmap_prepare,
+	.open		= generic_file_open,
+	.splice_read    = orangefs_file_splice_read,
+	.splice_write   = iter_file_splice_write,
+	.flush		= orangefs_flush,
+	.release	= orangefs_file_release,
+	.fsync		= orangefs_fsync,
+	.setlease	= generic_setlease,
+};
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
new file mode 100644
index 000000000..cd3273c88
--- /dev/null
+++ b/fs/orangefs/inode.c
@@ -0,0 +1,1167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * Copyright 2018 Omnibond Systems, L.L.C.
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS inode operations.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/fileattr.h>
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+static int orangefs_writepage_locked(struct folio *folio,
+		struct writeback_control *wbc)
+{
+	struct inode *inode = folio->mapping->host;
+	struct orangefs_write_range *wr = NULL;
+	struct iov_iter iter;
+	struct bio_vec bv;
+	size_t wlen;
+	ssize_t ret;
+	loff_t len, off;
+
+	folio_start_writeback(folio);
+
+	len = i_size_read(inode);
+	if (folio->private) {
+		wr = folio->private;
+		off = wr->pos;
+		if ((off + wr->len > len) && (off <= len))
+			wlen = len - off;
+		else
+			wlen = wr->len;
+		if (wlen == 0)
+			wlen = wr->len;
+	} else {
+		WARN_ON(1);
+		off = folio_pos(folio);
+		wlen = folio_size(folio);
+
+		if (wlen > len - off)
+			wlen = len - off;
+	}
+
+	WARN_ON(wlen == 0);
+	bvec_set_folio(&bv, folio, wlen, offset_in_folio(folio, off));
+	iov_iter_bvec(&iter, ITER_SOURCE, &bv, 1, wlen);
+
+	ret = wait_for_direct_io(ORANGEFS_IO_WRITE, inode, &off, &iter, wlen,
+	    len, wr, NULL, NULL);
+	if (ret < 0) {
+		mapping_set_error(folio->mapping, ret);
+	} else {
+		ret = 0;
+	}
+	kfree(folio_detach_private(folio));
+	return ret;
+}
+
+struct orangefs_writepages {
+	loff_t off;
+	size_t len;
+	kuid_t uid;
+	kgid_t gid;
+	int maxpages;
+	int nfolios;
+	struct address_space *mapping;
+	struct folio **folios;
+	struct bio_vec *bv;
+};
+
+static int orangefs_writepages_work(struct orangefs_writepages *ow,
+		struct writeback_control *wbc)
+{
+	struct inode *inode = ow->mapping->host;
+	struct orangefs_write_range *wrp, wr;
+	struct iov_iter iter;
+	ssize_t ret;
+	size_t start;
+	loff_t len, off;
+	int i;
+
+	len = i_size_read(inode);
+
+	start = offset_in_folio(ow->folios[0], ow->off);
+	for (i = 0; i < ow->nfolios; i++) {
+		folio_start_writeback(ow->folios[i]);
+		bvec_set_folio(&ow->bv[i], ow->folios[i],
+				folio_size(ow->folios[i]) - start, start);
+		start = 0;
+	}
+	iov_iter_bvec(&iter, ITER_SOURCE, ow->bv, ow->nfolios, ow->len);
+
+	WARN_ON(ow->off >= len);
+	if (ow->off + ow->len > len)
+		ow->len = len - ow->off;
+
+	off = ow->off;
+	wr.uid = ow->uid;
+	wr.gid = ow->gid;
+	ret = wait_for_direct_io(ORANGEFS_IO_WRITE, inode, &off, &iter, ow->len,
+	    0, &wr, NULL, NULL);
+	if (ret < 0)
+		mapping_set_error(ow->mapping, ret);
+	else
+		ret = 0;
+
+	for (i = 0; i < ow->nfolios; i++) {
+		wrp = folio_detach_private(ow->folios[i]);
+		kfree(wrp);
+		folio_end_writeback(ow->folios[i]);
+		folio_unlock(ow->folios[i]);
+	}
+
+	return ret;
+}
+
+static int orangefs_writepages_callback(struct folio *folio,
+		struct writeback_control *wbc, struct orangefs_writepages *ow)
+{
+	struct orangefs_write_range *wr = folio->private;
+	int ret;
+
+	if (!wr) {
+		folio_unlock(folio);
+		/* It's not private so there's nothing to write, right? */
+		printk("writepages_callback not private!\n");
+		BUG();
+		return 0;
+	}
+
+	ret = -1;
+	if (ow->nfolios == 0) {
+		ow->off = wr->pos;
+		ow->len = wr->len;
+		ow->uid = wr->uid;
+		ow->gid = wr->gid;
+		ow->folios[ow->nfolios++] = folio;
+		ret = 0;
+		goto done;
+	}
+	if (!uid_eq(ow->uid, wr->uid) || !gid_eq(ow->gid, wr->gid)) {
+		orangefs_writepages_work(ow, wbc);
+		ow->nfolios = 0;
+		ret = -1;
+		goto done;
+	}
+	if (ow->off + ow->len == wr->pos) {
+		ow->len += wr->len;
+		ow->folios[ow->nfolios++] = folio;
+		ret = 0;
+		goto done;
+	}
+done:
+	if (ret == -1) {
+		if (ow->nfolios) {
+			orangefs_writepages_work(ow, wbc);
+			ow->nfolios = 0;
+		}
+		ret = orangefs_writepage_locked(folio, wbc);
+		mapping_set_error(folio->mapping, ret);
+		folio_unlock(folio);
+		folio_end_writeback(folio);
+	} else {
+		if (ow->nfolios == ow->maxpages) {
+			orangefs_writepages_work(ow, wbc);
+			ow->nfolios = 0;
+		}
+	}
+	return ret;
+}
+
+static int orangefs_writepages(struct address_space *mapping,
+    struct writeback_control *wbc)
+{
+	struct orangefs_writepages *ow;
+	struct blk_plug plug;
+	int error;
+	struct folio *folio = NULL;
+
+	ow = kzalloc_obj(struct orangefs_writepages);
+	if (!ow)
+		return -ENOMEM;
+	ow->maxpages = orangefs_bufmap_size_query()/PAGE_SIZE;
+	ow->folios = kzalloc_objs(struct folio *, ow->maxpages);
+	if (!ow->folios) {
+		kfree(ow);
+		return -ENOMEM;
+	}
+	ow->bv = kzalloc_objs(struct bio_vec, ow->maxpages);
+	if (!ow->bv) {
+		kfree(ow->folios);
+		kfree(ow);
+		return -ENOMEM;
+	}
+	ow->mapping = mapping;
+	blk_start_plug(&plug);
+	while ((folio = writeback_iter(mapping, wbc, folio, &error)))
+		error = orangefs_writepages_callback(folio, wbc, ow);
+	if (ow->nfolios)
+		error = orangefs_writepages_work(ow, wbc);
+	blk_finish_plug(&plug);
+	kfree(ow->folios);
+	kfree(ow->bv);
+	kfree(ow);
+	return error;
+}
+
+static int orangefs_launder_folio(struct folio *);
+
+static void orangefs_readahead(struct readahead_control *rac)
+{
+	loff_t offset;
+	struct iov_iter iter;
+	struct inode *inode = rac->mapping->host;
+	struct xarray *i_pages;
+	struct folio *folio;
+	loff_t new_start = readahead_pos(rac);
+	int ret;
+	size_t new_len = 0;
+	size_t this_size;
+	size_t remaining;
+
+	loff_t bytes_remaining = inode->i_size - readahead_pos(rac);
+	loff_t pages_remaining = bytes_remaining / PAGE_SIZE;
+
+	if (pages_remaining >= 1024)
+		new_len = 4194304;
+	else if (pages_remaining > readahead_count(rac))
+		new_len = bytes_remaining;
+
+	if (new_len)
+		readahead_expand(rac, new_start, new_len);
+
+	offset = readahead_pos(rac);
+	i_pages = &rac->mapping->i_pages;
+
+	iov_iter_xarray(&iter, ITER_DEST, i_pages,
+				offset, readahead_length(rac));
+
+	remaining = readahead_length(rac);
+	while (remaining) {
+		if (remaining > 4194304)
+			this_size = 4194304;
+		else
+			this_size = remaining;
+
+		/* read in the pages. */
+		if ((ret = wait_for_direct_io(ORANGEFS_IO_READ, inode,
+				&offset, &iter, this_size,
+				inode->i_size, NULL, NULL, rac->file)) < 0) {
+			gossip_debug(GOSSIP_FILE_DEBUG,
+				"%s: wait_for_direct_io failed. :%d: \n",
+				__func__, ret);
+			goto cleanup;
+		} else {
+			ret = 0;
+		}
+
+		remaining -= this_size;
+		offset += this_size;
+	}
+
+cleanup:
+	/* clean up. */
+	while ((folio = readahead_folio(rac))) {
+		if (!ret)
+			folio_mark_uptodate(folio);
+		folio_unlock(folio);
+	}
+}
+
+static int orangefs_read_folio(struct file *file, struct folio *folio)
+{
+	struct inode *inode = folio->mapping->host;
+	struct iov_iter iter;
+	struct bio_vec bv;
+	ssize_t ret;
+	loff_t off; /* offset of this folio in the file */
+
+	if (folio_test_dirty(folio))
+		orangefs_launder_folio(folio);
+
+	off = folio_pos(folio);
+	bvec_set_folio(&bv, folio, folio_size(folio), 0);
+	iov_iter_bvec(&iter, ITER_DEST, &bv, 1, folio_size(folio));
+
+	ret = wait_for_direct_io(ORANGEFS_IO_READ, inode, &off, &iter,
+			folio_size(folio), inode->i_size, NULL, NULL, file);
+	/* this will only zero remaining unread portions of the folio data */
+	iov_iter_zero(~0U, &iter);
+	/* takes care of potential aliasing */
+	flush_dcache_folio(folio);
+	if (ret > 0)
+		ret = 0;
+	folio_end_read(folio, ret == 0);
+	return ret;
+}
+
+static int orangefs_write_begin(const struct kiocb *iocb,
+				struct address_space *mapping, loff_t pos,
+				unsigned len, struct folio **foliop,
+				void **fsdata)
+{
+	struct orangefs_write_range *wr;
+	struct folio *folio;
+	int ret;
+
+	folio = __filemap_get_folio(mapping, pos / PAGE_SIZE, FGP_WRITEBEGIN,
+			mapping_gfp_mask(mapping));
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
+
+	*foliop = folio;
+
+	if (folio_test_dirty(folio) && !folio_test_private(folio)) {
+		/*
+		 * Should be impossible.  If it happens, launder the page
+		 * since we don't know what's dirty.  This will WARN in
+		 * orangefs_writepage_locked.
+		 */
+		ret = orangefs_launder_folio(folio);
+		if (ret)
+			return ret;
+	}
+	if (folio_test_private(folio)) {
+		struct orangefs_write_range *wr;
+		wr = folio_get_private(folio);
+		if (wr->pos + wr->len == pos &&
+		    uid_eq(wr->uid, current_fsuid()) &&
+		    gid_eq(wr->gid, current_fsgid())) {
+			wr->len += len;
+			goto okay;
+		} else {
+			wr->pos = pos;
+			wr->len = len;
+			ret = orangefs_launder_folio(folio);
+			if (ret)
+				return ret;
+		}
+	}
+
+	wr = kmalloc_obj(*wr);
+	if (!wr)
+		return -ENOMEM;
+
+	wr->pos = pos;
+	wr->len = len;
+	wr->uid = current_fsuid();
+	wr->gid = current_fsgid();
+	folio_attach_private(folio, wr);
+okay:
+	return 0;
+}
+
+static int orangefs_write_end(const struct kiocb *iocb,
+			      struct address_space *mapping,
+			      loff_t pos, unsigned len, unsigned copied,
+			      struct folio *folio, void *fsdata)
+{
+	struct inode *inode = folio->mapping->host;
+	loff_t last_pos = pos + copied;
+
+	/*
+	 * No need to use i_size_read() here, the i_size
+	 * cannot change under us because we hold the i_mutex.
+	 */
+	if (last_pos > inode->i_size)
+		i_size_write(inode, last_pos);
+
+	/* zero the stale part of the folio if we did a short copy */
+	if (!folio_test_uptodate(folio)) {
+		unsigned from = pos & (PAGE_SIZE - 1);
+		if (copied < len) {
+			folio_zero_range(folio, from + copied, len - copied);
+		}
+		/* Set fully written pages uptodate. */
+		if (pos == folio_pos(folio) &&
+		    (len == PAGE_SIZE || pos + len == inode->i_size)) {
+			folio_zero_segment(folio, from + copied, PAGE_SIZE);
+			folio_mark_uptodate(folio);
+		}
+	}
+
+	folio_mark_dirty(folio);
+	folio_unlock(folio);
+	folio_put(folio);
+
+	mark_inode_dirty_sync(file_inode(iocb->ki_filp));
+	return copied;
+}
+
+static void orangefs_invalidate_folio(struct folio *folio,
+				 size_t offset, size_t length)
+{
+	struct orangefs_write_range *wr = folio_get_private(folio);
+
+	if (offset == 0 && length == PAGE_SIZE) {
+		kfree(folio_detach_private(folio));
+		return;
+	/* write range entirely within invalidate range (or equal) */
+	} else if (folio_pos(folio) + offset <= wr->pos &&
+	    wr->pos + wr->len <= folio_pos(folio) + offset + length) {
+		kfree(folio_detach_private(folio));
+		/* XXX is this right? only caller in fs */
+		folio_cancel_dirty(folio);
+		return;
+	/* invalidate range chops off end of write range */
+	} else if (wr->pos < folio_pos(folio) + offset &&
+	    wr->pos + wr->len <= folio_pos(folio) + offset + length &&
+	     folio_pos(folio) + offset < wr->pos + wr->len) {
+		size_t x;
+		x = wr->pos + wr->len - (folio_pos(folio) + offset);
+		WARN_ON(x > wr->len);
+		wr->len -= x;
+		wr->uid = current_fsuid();
+		wr->gid = current_fsgid();
+	/* invalidate range chops off beginning of write range */
+	} else if (folio_pos(folio) + offset <= wr->pos &&
+	    folio_pos(folio) + offset + length < wr->pos + wr->len &&
+	    wr->pos < folio_pos(folio) + offset + length) {
+		size_t x;
+		x = folio_pos(folio) + offset + length - wr->pos;
+		WARN_ON(x > wr->len);
+		wr->pos += x;
+		wr->len -= x;
+		wr->uid = current_fsuid();
+		wr->gid = current_fsgid();
+	/* invalidate range entirely within write range (punch hole) */
+	} else if (wr->pos < folio_pos(folio) + offset &&
+	    folio_pos(folio) + offset + length < wr->pos + wr->len) {
+		/* XXX what do we do here... should not WARN_ON */
+		WARN_ON(1);
+		/* punch hole */
+		/*
+		 * should we just ignore this and write it out anyway?
+		 * it hardly makes sense
+		 */
+		return;
+	/* non-overlapping ranges */
+	} else {
+		/* WARN if they do overlap */
+		if (!((folio_pos(folio) + offset + length <= wr->pos) ^
+		    (wr->pos + wr->len <= folio_pos(folio) + offset))) {
+			WARN_ON(1);
+			printk("invalidate range offset %llu length %zu\n",
+			    folio_pos(folio) + offset, length);
+			printk("write range offset %llu length %zu\n",
+			    wr->pos, wr->len);
+		}
+		return;
+	}
+
+	/*
+	 * Above there are returns where wr is freed or where we WARN.
+	 * Thus the following runs if wr was modified above.
+	 */
+
+	orangefs_launder_folio(folio);
+}
+
+static bool orangefs_release_folio(struct folio *folio, gfp_t foo)
+{
+	return !folio_test_private(folio);
+}
+
+static void orangefs_free_folio(struct folio *folio)
+{
+	kfree(folio_detach_private(folio));
+}
+
+static int orangefs_launder_folio(struct folio *folio)
+{
+	int r = 0;
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = 0,
+	};
+	folio_wait_writeback(folio);
+	if (folio_clear_dirty_for_io(folio)) {
+		r = orangefs_writepage_locked(folio, &wbc);
+		folio_end_writeback(folio);
+	}
+	return r;
+}
+
+static ssize_t orangefs_direct_IO(struct kiocb *iocb,
+				  struct iov_iter *iter)
+{
+	/*
+	 * Comment from original do_readv_writev:
+	 * Common entry point for read/write/readv/writev
+	 * This function will dispatch it to either the direct I/O
+	 * or buffered I/O path depending on the mount options and/or
+	 * augmented/extended metadata attached to the file.
+	 * Note: File extended attributes override any mount options.
+	 */
+	struct file *file = iocb->ki_filp;
+	loff_t pos = iocb->ki_pos;
+	enum ORANGEFS_io_type type = iov_iter_rw(iter) == WRITE ?
+            ORANGEFS_IO_WRITE : ORANGEFS_IO_READ;
+	loff_t *offset = &pos;
+	struct inode *inode = file->f_mapping->host;
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_khandle *handle = &orangefs_inode->refn.khandle;
+	size_t count = iov_iter_count(iter);
+	ssize_t total_count = 0;
+	ssize_t ret = -EINVAL;
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		"%s-BEGIN(%pU): count(%d) after estimate_max_iovecs.\n",
+		__func__,
+		handle,
+		(int)count);
+
+	if (type == ORANGEFS_IO_WRITE) {
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s(%pU): proceeding with offset : %llu, "
+			     "size %d\n",
+			     __func__,
+			     handle,
+			     llu(*offset),
+			     (int)count);
+	}
+
+	if (count == 0) {
+		ret = 0;
+		goto out;
+	}
+
+	while (iov_iter_count(iter)) {
+		size_t each_count = iov_iter_count(iter);
+		size_t amt_complete;
+
+		/* how much to transfer in this loop iteration */
+		if (each_count > orangefs_bufmap_size_query())
+			each_count = orangefs_bufmap_size_query();
+
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s(%pU): size of each_count(%d)\n",
+			     __func__,
+			     handle,
+			     (int)each_count);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s(%pU): BEFORE wait_for_io: offset is %d\n",
+			     __func__,
+			     handle,
+			     (int)*offset);
+
+		ret = wait_for_direct_io(type, inode, offset, iter,
+				each_count, 0, NULL, NULL, file);
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s(%pU): return from wait_for_io:%d\n",
+			     __func__,
+			     handle,
+			     (int)ret);
+
+		if (ret < 0)
+			goto out;
+
+		*offset += ret;
+		total_count += ret;
+		amt_complete = ret;
+
+		gossip_debug(GOSSIP_FILE_DEBUG,
+			     "%s(%pU): AFTER wait_for_io: offset is %d\n",
+			     __func__,
+			     handle,
+			     (int)*offset);
+
+		/*
+		 * if we got a short I/O operations,
+		 * fall out and return what we got so far
+		 */
+		if (amt_complete < each_count)
+			break;
+	} /*end while */
+
+out:
+	if (total_count > 0)
+		ret = total_count;
+	if (ret > 0) {
+		if (type == ORANGEFS_IO_READ) {
+			file_accessed(file);
+		} else {
+			file_update_time(file);
+			if (*offset > i_size_read(inode))
+				i_size_write(inode, *offset);
+		}
+	}
+
+	gossip_debug(GOSSIP_FILE_DEBUG,
+		     "%s(%pU): Value(%d) returned.\n",
+		     __func__,
+		     handle,
+		     (int)ret);
+
+	return ret;
+}
+
+/** ORANGEFS2 implementation of address space operations */
+static const struct address_space_operations orangefs_address_operations = {
+	.readahead = orangefs_readahead,
+	.read_folio = orangefs_read_folio,
+	.writepages = orangefs_writepages,
+	.dirty_folio = filemap_dirty_folio,
+	.write_begin = orangefs_write_begin,
+	.write_end = orangefs_write_end,
+	.invalidate_folio = orangefs_invalidate_folio,
+	.release_folio = orangefs_release_folio,
+	.free_folio = orangefs_free_folio,
+	.migrate_folio = filemap_migrate_folio,
+	.launder_folio = orangefs_launder_folio,
+	.direct_IO = orangefs_direct_IO,
+};
+
+vm_fault_t orangefs_page_mkwrite(struct vm_fault *vmf)
+{
+	struct folio *folio = page_folio(vmf->page);
+	struct inode *inode = file_inode(vmf->vma->vm_file);
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	unsigned long *bitlock = &orangefs_inode->bitlock;
+	vm_fault_t ret;
+	struct orangefs_write_range *wr;
+
+	sb_start_pagefault(inode->i_sb);
+
+	if (wait_on_bit(bitlock, 1, TASK_KILLABLE)) {
+		ret = VM_FAULT_RETRY;
+		goto out;
+	}
+
+	folio_lock(folio);
+	if (folio_test_dirty(folio) && !folio_test_private(folio)) {
+		/*
+		 * Should be impossible.  If it happens, launder the folio
+		 * since we don't know what's dirty.  This will WARN in
+		 * orangefs_writepage_locked.
+		 */
+		if (orangefs_launder_folio(folio)) {
+			ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
+			goto out;
+		}
+	}
+	if (folio_test_private(folio)) {
+		wr = folio_get_private(folio);
+		if (uid_eq(wr->uid, current_fsuid()) &&
+		    gid_eq(wr->gid, current_fsgid())) {
+			wr->pos = folio_pos(folio);
+			wr->len = folio_size(folio);
+			goto okay;
+		} else {
+			if (orangefs_launder_folio(folio)) {
+				ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
+				goto out;
+			}
+		}
+	}
+	wr = kmalloc_obj(*wr);
+	if (!wr) {
+		ret = VM_FAULT_LOCKED|VM_FAULT_RETRY;
+		goto out;
+	}
+	wr->pos = folio_pos(folio);
+	wr->len = folio_size(folio);
+	wr->uid = current_fsuid();
+	wr->gid = current_fsgid();
+	folio_attach_private(folio, wr);
+okay:
+
+	file_update_time(vmf->vma->vm_file);
+	if (folio->mapping != inode->i_mapping) {
+		folio_unlock(folio);
+		ret = VM_FAULT_LOCKED|VM_FAULT_NOPAGE;
+		goto out;
+	}
+
+	/*
+	 * We mark the folio dirty already here so that when freeze is in
+	 * progress, we are guaranteed that writeback during freezing will
+	 * see the dirty folio and writeprotect it again.
+	 */
+	folio_mark_dirty(folio);
+	folio_wait_stable(folio);
+	ret = VM_FAULT_LOCKED;
+out:
+	sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static int orangefs_setattr_size(struct inode *inode, struct iattr *iattr)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	loff_t orig_size;
+	int ret = -EINVAL;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "%s: %pU: Handle is %pU | fs_id %d | size is %llu\n",
+		     __func__,
+		     get_khandle_from_ino(inode),
+		     &orangefs_inode->refn.khandle,
+		     orangefs_inode->refn.fs_id,
+		     iattr->ia_size);
+
+	/* Ensure that we have a up to date size, so we know if it changed. */
+	ret = orangefs_inode_getattr(inode, ORANGEFS_GETATTR_SIZE);
+	if (ret == -ESTALE)
+		ret = -EIO;
+	if (ret) {
+		gossip_err("%s: orangefs_inode_getattr failed, ret:%d:.\n",
+		    __func__, ret);
+		return ret;
+	}
+	orig_size = i_size_read(inode);
+
+	/* This is truncate_setsize in a different order. */
+	truncate_pagecache(inode, iattr->ia_size);
+	i_size_write(inode, iattr->ia_size);
+	if (iattr->ia_size > orig_size)
+		pagecache_isize_extended(inode, orig_size, iattr->ia_size);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_TRUNCATE);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.truncate.refn = orangefs_inode->refn;
+	new_op->upcall.req.truncate.size = (__s64) iattr->ia_size;
+
+	ret = service_operation(new_op,
+		__func__,
+		get_interruptible_flag(inode));
+
+	/*
+	 * the truncate has no downcall members to retrieve, but
+	 * the status value tells us if it went through ok or not
+	 */
+	gossip_debug(GOSSIP_INODE_DEBUG, "%s: ret:%d:\n", __func__, ret);
+
+	op_release(new_op);
+
+	if (ret != 0)
+		return ret;
+
+	if (orig_size != i_size_read(inode))
+		iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
+
+	return ret;
+}
+
+int __orangefs_setattr(struct inode *inode, struct iattr *iattr)
+{
+	int ret;
+
+	if (iattr->ia_valid & ATTR_MODE) {
+		if (iattr->ia_mode & (S_ISVTX)) {
+			if (is_root_handle(inode)) {
+				/*
+				 * allow sticky bit to be set on root (since
+				 * it shows up that way by default anyhow),
+				 * but don't show it to the server
+				 */
+				iattr->ia_mode -= S_ISVTX;
+			} else {
+				gossip_debug(GOSSIP_UTILS_DEBUG,
+					     "User attempted to set sticky bit on non-root directory; returning EINVAL.\n");
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+		if (iattr->ia_mode & (S_ISUID)) {
+			gossip_debug(GOSSIP_UTILS_DEBUG,
+				     "Attempting to set setuid bit (not supported); returning EINVAL.\n");
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+	if (iattr->ia_valid & ATTR_SIZE) {
+		ret = orangefs_setattr_size(inode, iattr);
+		if (ret)
+			goto out;
+	}
+
+again:
+	spin_lock(&inode->i_lock);
+	if (ORANGEFS_I(inode)->attr_valid) {
+		if (uid_eq(ORANGEFS_I(inode)->attr_uid, current_fsuid()) &&
+		    gid_eq(ORANGEFS_I(inode)->attr_gid, current_fsgid())) {
+			ORANGEFS_I(inode)->attr_valid = iattr->ia_valid;
+		} else {
+			spin_unlock(&inode->i_lock);
+			write_inode_now(inode, 1);
+			goto again;
+		}
+	} else {
+		ORANGEFS_I(inode)->attr_valid = iattr->ia_valid;
+		ORANGEFS_I(inode)->attr_uid = current_fsuid();
+		ORANGEFS_I(inode)->attr_gid = current_fsgid();
+	}
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
+	spin_unlock(&inode->i_lock);
+	mark_inode_dirty(inode);
+
+	ret = 0;
+out:
+	return ret;
+}
+
+int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr)
+{
+	int ret;
+	struct inode *inode = d_inode(dentry);
+
+	ret = __orangefs_setattr(inode, iattr);
+	/* change mode on a file that has ACLs */
+	if (!ret && (iattr->ia_valid & ATTR_MODE))
+		ret = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
+	return ret;
+}
+
+/*
+ * Change attributes of an object referenced by dentry.
+ */
+int orangefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		     struct iattr *iattr)
+{
+	int ret;
+	gossip_debug(GOSSIP_INODE_DEBUG, "__orangefs_setattr: called on %pd\n",
+	    dentry);
+	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
+	if (ret)
+	        goto out;
+	ret = __orangefs_setattr_mode(dentry, iattr);
+	sync_inode_metadata(d_inode(dentry), 1);
+out:
+	gossip_debug(GOSSIP_INODE_DEBUG, "orangefs_setattr: returning %d\n",
+	    ret);
+	return ret;
+}
+
+/*
+ * Obtain attributes of an object given a dentry
+ */
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
+		     struct kstat *stat, u32 request_mask, unsigned int flags)
+{
+	int ret;
+	struct inode *inode = path->dentry->d_inode;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "orangefs_getattr: called on %pd mask %u\n",
+		     path->dentry, request_mask);
+
+	ret = orangefs_inode_getattr(inode,
+	    request_mask & STATX_SIZE ? ORANGEFS_GETATTR_SIZE : 0);
+	if (ret == 0) {
+		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
+
+		/* override block size reported to stat */
+		if (!(request_mask & STATX_SIZE))
+			stat->result_mask &= ~STATX_SIZE;
+
+		generic_fill_statx_attr(inode, stat);
+	}
+	return ret;
+}
+
+int orangefs_permission(struct mnt_idmap *idmap,
+			struct inode *inode, int mask)
+{
+	int ret;
+
+	if (mask & MAY_NOT_BLOCK)
+		return -ECHILD;
+
+	gossip_debug(GOSSIP_INODE_DEBUG, "%s: refreshing\n", __func__);
+
+	/* Make sure the permission (and other common attrs) are up to date. */
+	ret = orangefs_inode_getattr(inode, 0);
+	if (ret < 0)
+		return ret;
+
+	return generic_permission(&nop_mnt_idmap, inode, mask);
+}
+
+int orangefs_update_time(struct inode *inode, enum fs_update_time type,
+		unsigned int flags)
+{
+	struct iattr iattr = { };
+	int dirty;
+
+	if (flags & IOCB_NOWAIT)
+		return -EAGAIN;
+
+	switch (type) {
+	case FS_UPD_ATIME:
+		iattr.ia_valid = ATTR_ATIME;
+		break;
+	case FS_UPD_CMTIME:
+		iattr.ia_valid = ATTR_CTIME | ATTR_MTIME;
+		break;
+	}
+
+	dirty = inode_update_time(inode, type, flags);
+	if (dirty <= 0)
+		return dirty;
+	return __orangefs_setattr(inode, &iattr);
+}
+
+static int orangefs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	u64 val = 0;
+	int ret;
+
+	gossip_debug(GOSSIP_FILE_DEBUG, "%s: called on %pd\n", __func__,
+		     dentry);
+
+	ret = orangefs_inode_getxattr(d_inode(dentry),
+				      "user.pvfs2.meta_hint",
+				      &val, sizeof(val));
+	if (ret < 0 && ret != -ENODATA)
+		return ret;
+
+	gossip_debug(GOSSIP_FILE_DEBUG, "%s: flags=%u\n", __func__, (u32) val);
+
+	fileattr_fill_flags(fa, val);
+	return 0;
+}
+
+static int orangefs_fileattr_set(struct mnt_idmap *idmap,
+				 struct dentry *dentry, struct file_kattr *fa)
+{
+	u64 val = 0;
+
+	gossip_debug(GOSSIP_FILE_DEBUG, "%s: called on %pd\n", __func__,
+		     dentry);
+	/*
+	 * ORANGEFS_MIRROR_FL is set internally when the mirroring mode is
+	 * turned on for a file. The user is not allowed to turn on this bit,
+	 * but the bit is present if the user first gets the flags and then
+	 * updates the flags with some new settings. So, we ignore it in the
+	 * following edit. bligon.
+	 */
+	if (fileattr_has_fsx(fa) ||
+	    (fa->flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NOATIME_FL | ORANGEFS_MIRROR_FL))) {
+		gossip_err("%s: only supports setting one of FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NOATIME_FL\n",
+			   __func__);
+		return -EOPNOTSUPP;
+	}
+	val = fa->flags;
+	gossip_debug(GOSSIP_FILE_DEBUG, "%s: flags=%u\n", __func__, (u32) val);
+	return orangefs_inode_setxattr(d_inode(dentry),
+				       "user.pvfs2.meta_hint",
+				       &val, sizeof(val), 0);
+}
+
+/* ORANGEFS2 implementation of VFS inode operations for files */
+static const struct inode_operations orangefs_file_inode_operations = {
+	.get_inode_acl = orangefs_get_acl,
+	.set_acl = orangefs_set_acl,
+	.setattr = orangefs_setattr,
+	.getattr = orangefs_getattr,
+	.listxattr = orangefs_listxattr,
+	.permission = orangefs_permission,
+	.update_time = orangefs_update_time,
+	.fileattr_get = orangefs_fileattr_get,
+	.fileattr_set = orangefs_fileattr_set,
+};
+
+static int orangefs_init_iops(struct inode *inode)
+{
+	inode->i_mapping->a_ops = &orangefs_address_operations;
+
+	switch (inode->i_mode & S_IFMT) {
+	case S_IFREG:
+		inode->i_op = &orangefs_file_inode_operations;
+		inode->i_fop = &orangefs_file_operations;
+		break;
+	case S_IFLNK:
+		inode->i_op = &orangefs_symlink_inode_operations;
+		break;
+	case S_IFDIR:
+		inode->i_op = &orangefs_dir_inode_operations;
+		inode->i_fop = &orangefs_dir_operations;
+		break;
+	default:
+		gossip_debug(GOSSIP_INODE_DEBUG,
+			     "%s: unsupported mode\n",
+			     __func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Given an ORANGEFS object identifier (fsid, handle), convert it into
+ * a ino_t type that will be used as a hash-index from where the handle will
+ * be searched for in the VFS hash table of inodes.
+ */
+static inline ino_t orangefs_handle_hash(struct orangefs_object_kref *ref)
+{
+	if (!ref)
+		return 0;
+	return orangefs_khandle_to_ino(&(ref->khandle));
+}
+
+/*
+ * Called to set up an inode from iget5_locked.
+ */
+static int orangefs_set_inode(struct inode *inode, void *data)
+{
+	struct orangefs_object_kref *ref = (struct orangefs_object_kref *) data;
+	ORANGEFS_I(inode)->refn.fs_id = ref->fs_id;
+	ORANGEFS_I(inode)->refn.khandle = ref->khandle;
+	ORANGEFS_I(inode)->attr_valid = 0;
+	hash_init(ORANGEFS_I(inode)->xattr_cache);
+	ORANGEFS_I(inode)->mapping_time = jiffies - 1;
+	ORANGEFS_I(inode)->bitlock = 0;
+	return 0;
+}
+
+/*
+ * Called to determine if handles match.
+ */
+static int orangefs_test_inode(struct inode *inode, void *data)
+{
+	struct orangefs_object_kref *ref = (struct orangefs_object_kref *) data;
+	struct orangefs_inode_s *orangefs_inode = NULL;
+
+	orangefs_inode = ORANGEFS_I(inode);
+	/* test handles and fs_ids... */
+	return (!ORANGEFS_khandle_cmp(&(orangefs_inode->refn.khandle),
+				&(ref->khandle)) &&
+			orangefs_inode->refn.fs_id == ref->fs_id);
+}
+
+/*
+ * Front-end to lookup the inode-cache maintained by the VFS using the ORANGEFS
+ * file handle.
+ *
+ * @sb: the file system super block instance.
+ * @ref: The ORANGEFS object for which we are trying to locate an inode.
+ */
+struct inode *orangefs_iget(struct super_block *sb,
+		struct orangefs_object_kref *ref)
+{
+	struct inode *inode = NULL;
+	unsigned long hash;
+	int error;
+
+	hash = orangefs_handle_hash(ref);
+	inode = iget5_locked(sb,
+			hash,
+			orangefs_test_inode,
+			orangefs_set_inode,
+			ref);
+
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	if (!(inode_state_read_once(inode) & I_NEW))
+		return inode;
+
+	error = orangefs_inode_getattr(inode, ORANGEFS_GETATTR_NEW);
+	if (error) {
+		iget_failed(inode);
+		return ERR_PTR(error);
+	}
+
+	inode->i_ino = hash;	/* needed for stat etc */
+	orangefs_init_iops(inode);
+	unlock_new_inode(inode);
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "iget handle %pU, fsid %d hash %ld i_ino %llu\n",
+		     &ref->khandle,
+		     ref->fs_id,
+		     hash,
+		     inode->i_ino);
+
+	return inode;
+}
+
+/*
+ * Allocate an inode for a newly created file and insert it into the inode hash.
+ */
+struct inode *orangefs_new_inode(struct super_block *sb, struct inode *dir,
+		umode_t mode, dev_t dev, struct orangefs_object_kref *ref)
+{
+	struct posix_acl *acl = NULL, *default_acl = NULL;
+	unsigned long hash = orangefs_handle_hash(ref);
+	struct inode *inode;
+	int error;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "%s:(sb is %p | MAJOR(dev)=%u | MINOR(dev)=%u mode=%o)\n",
+		     __func__,
+		     sb,
+		     MAJOR(dev),
+		     MINOR(dev),
+		     mode);
+
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	error = posix_acl_create(dir, &mode, &default_acl, &acl);
+	if (error)
+		goto out_iput;
+
+	orangefs_set_inode(inode, ref);
+	inode->i_ino = hash;	/* needed for stat etc */
+
+	error = orangefs_inode_getattr(inode, ORANGEFS_GETATTR_NEW);
+	if (error)
+		goto out_iput;
+
+	orangefs_init_iops(inode);
+	inode->i_rdev = dev;
+
+	if (default_acl) {
+		error = __orangefs_set_acl(inode, default_acl,
+					   ACL_TYPE_DEFAULT);
+		if (error)
+			goto out_iput;
+	}
+
+	if (acl) {
+		error = __orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
+		if (error)
+			goto out_iput;
+	}
+
+	error = insert_inode_locked4(inode, hash, orangefs_test_inode, ref);
+	if (error < 0)
+		goto out_iput;
+
+	gossip_debug(GOSSIP_INODE_DEBUG,
+		     "Initializing ACL's for inode %pU\n",
+		     get_khandle_from_ino(inode));
+	if (mode != inode->i_mode) {
+		struct iattr iattr = {
+			.ia_mode = mode,
+			.ia_valid = ATTR_MODE,
+		};
+		inode->i_mode = mode;
+		__orangefs_setattr(inode, &iattr);
+		__posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
+	}
+	posix_acl_release(acl);
+	posix_acl_release(default_acl);
+	return inode;
+
+out_iput:
+	iput(inode);
+	posix_acl_release(acl);
+	posix_acl_release(default_acl);
+	return ERR_PTR(error);
+}
diff --git a/fs/orangefs/namei.c b/fs/orangefs/namei.c
new file mode 100644
index 000000000..8ebc34e11
--- /dev/null
+++ b/fs/orangefs/namei.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS namei operations.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+
+/*
+ * Get a newly allocated inode to go with a negative dentry.
+ */
+static int orangefs_create(struct mnt_idmap *idmap,
+			struct inode *dir,
+			struct dentry *dentry,
+			umode_t mode)
+{
+	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
+	struct orangefs_kernel_op_s *new_op;
+	struct orangefs_object_kref ref;
+	struct inode *inode;
+	struct iattr iattr;
+	int ret;
+
+	gossip_debug(GOSSIP_NAME_DEBUG, "%s: %pd\n",
+		     __func__,
+		     dentry);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_CREATE);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.create.parent_refn = parent->refn;
+
+	fill_default_sys_attrs(new_op->upcall.req.create.attributes, mode);
+
+	strscpy(new_op->upcall.req.create.d_name, dentry->d_name.name);
+
+	ret = service_operation(new_op, __func__, get_interruptible_flag(dir));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: %pd: handle:%pU: fsid:%d: new_op:%p: ret:%d:\n",
+		     __func__,
+		     dentry,
+		     &new_op->downcall.resp.create.refn.khandle,
+		     new_op->downcall.resp.create.refn.fs_id,
+		     new_op,
+		     ret);
+
+	if (ret < 0)
+		goto out;
+
+	ref = new_op->downcall.resp.create.refn;
+
+	inode = orangefs_new_inode(dir->i_sb, dir, S_IFREG | mode, 0, &ref);
+	if (IS_ERR(inode)) {
+		gossip_err("%s: Failed to allocate inode for file :%pd:\n",
+			   __func__,
+			   dentry);
+		ret = PTR_ERR(inode);
+		goto out;
+	}
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: Assigned inode :%pU: for file :%pd:\n",
+		     __func__,
+		     get_khandle_from_ino(inode),
+		     dentry);
+
+	d_instantiate_new(dentry, inode);
+	orangefs_set_timeout(dentry);
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: dentry instantiated for %pd\n",
+		     __func__,
+		     dentry);
+
+	memset(&iattr, 0, sizeof iattr);
+	iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+	iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
+	__orangefs_setattr(dir, &iattr);
+	ret = 0;
+out:
+	op_release(new_op);
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: %pd: returning %d\n",
+		     __func__,
+		     dentry,
+		     ret);
+	return ret;
+}
+
+/*
+ * Attempt to resolve an object name (dentry->d_name), parent handle, and
+ * fsid into a handle for the object.
+ */
+static struct dentry *orangefs_lookup(struct inode *dir, struct dentry *dentry,
+				   unsigned int flags)
+{
+	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
+	struct orangefs_kernel_op_s *new_op;
+	struct inode *inode;
+	int ret = -EINVAL;
+
+	/*
+	 * in theory we could skip a lookup here (if the intent is to
+	 * create) in order to avoid a potentially failed lookup, but
+	 * leaving it in can skip a valid lookup and try to create a file
+	 * that already exists (e.g. the vfs already handles checking for
+	 * -EEXIST on O_EXCL opens, which is broken if we skip this lookup
+	 * in the create path)
+	 */
+	gossip_debug(GOSSIP_NAME_DEBUG, "%s called on %pd\n",
+		     __func__, dentry);
+
+	if (dentry->d_name.len > (ORANGEFS_NAME_MAX - 1))
+		return ERR_PTR(-ENAMETOOLONG);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP);
+	if (!new_op)
+		return ERR_PTR(-ENOMEM);
+
+	new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;
+
+	gossip_debug(GOSSIP_NAME_DEBUG, "%s:%s:%d using parent %pU\n",
+		     __FILE__,
+		     __func__,
+		     __LINE__,
+		     &parent->refn.khandle);
+	new_op->upcall.req.lookup.parent_refn = parent->refn;
+
+	strscpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name);
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: doing lookup on %s under %pU,%d\n",
+		     __func__,
+		     new_op->upcall.req.lookup.d_name,
+		     &new_op->upcall.req.lookup.parent_refn.khandle,
+		     new_op->upcall.req.lookup.parent_refn.fs_id);
+
+	ret = service_operation(new_op, __func__, get_interruptible_flag(dir));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Lookup Got %pU, fsid %d (ret=%d)\n",
+		     &new_op->downcall.resp.lookup.refn.khandle,
+		     new_op->downcall.resp.lookup.refn.fs_id,
+		     ret);
+
+	if (ret == 0) {
+		orangefs_set_timeout(dentry);
+		inode = orangefs_iget(dir->i_sb, &new_op->downcall.resp.lookup.refn);
+	} else if (ret == -ENOENT) {
+		inode = NULL;
+	} else {
+		/* must be a non-recoverable error */
+		inode = ERR_PTR(ret);
+	}
+
+	op_release(new_op);
+	return d_splice_alias(inode, dentry);
+}
+
+/* return 0 on success; non-zero otherwise */
+static int orangefs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
+	struct orangefs_kernel_op_s *new_op;
+	struct iattr iattr;
+	int ret;
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: called on %pd\n"
+		     "  (inode %pU): Parent is %pU | fs_id %d\n",
+		     __func__,
+		     dentry,
+		     get_khandle_from_ino(inode),
+		     &parent->refn.khandle,
+		     parent->refn.fs_id);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_REMOVE);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.remove.parent_refn = parent->refn;
+	strscpy(new_op->upcall.req.remove.d_name, dentry->d_name.name);
+
+	ret = service_operation(new_op, "orangefs_unlink",
+				get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "%s: service_operation returned:%d:\n",
+		     __func__,
+		     ret);
+
+	op_release(new_op);
+
+	if (!ret) {
+		drop_nlink(inode);
+
+		memset(&iattr, 0, sizeof iattr);
+		iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+		iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
+		__orangefs_setattr(dir, &iattr);
+	}
+	return ret;
+}
+
+static int orangefs_symlink(struct mnt_idmap *idmap,
+		         struct inode *dir,
+			 struct dentry *dentry,
+			 const char *symname)
+{
+	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
+	struct orangefs_kernel_op_s *new_op;
+	struct orangefs_object_kref ref;
+	struct inode *inode;
+	struct iattr iattr;
+	int mode = 0755;
+	int ret;
+
+	gossip_debug(GOSSIP_NAME_DEBUG, "%s: called\n", __func__);
+
+	if (!symname)
+		return -EINVAL;
+
+	if (strlen(symname)+1 > ORANGEFS_NAME_MAX)
+		return -ENAMETOOLONG;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_SYMLINK);
+	if (!new_op)
+		return -ENOMEM;
+
+	new_op->upcall.req.sym.parent_refn = parent->refn;
+
+	fill_default_sys_attrs(new_op->upcall.req.sym.attributes, mode);
+
+	strscpy(new_op->upcall.req.sym.entry_name, dentry->d_name.name);
+	strscpy(new_op->upcall.req.sym.target, symname);
+
+	ret = service_operation(new_op, __func__, get_interruptible_flag(dir));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Symlink Got ORANGEFS handle %pU on fsid %d (ret=%d)\n",
+		     &new_op->downcall.resp.sym.refn.khandle,
+		     new_op->downcall.resp.sym.refn.fs_id, ret);
+
+	if (ret < 0) {
+		gossip_debug(GOSSIP_NAME_DEBUG,
+			    "%s: failed with error code %d\n",
+			    __func__, ret);
+		goto out;
+	}
+
+	ref = new_op->downcall.resp.sym.refn;
+
+	inode = orangefs_new_inode(dir->i_sb, dir, S_IFLNK | mode, 0, &ref);
+	if (IS_ERR(inode)) {
+		gossip_err
+		    ("*** Failed to allocate orangefs symlink inode\n");
+		ret = PTR_ERR(inode);
+		goto out;
+	}
+	/*
+	 * This is necessary because orangefs_inode_getattr will not
+	 * re-read symlink size as it is impossible for it to change.
+	 * Invalidating the cache does not help.  orangefs_new_inode
+	 * does not set the correct size (it does not know symname).
+	 */
+	inode->i_size = strlen(symname);
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Assigned symlink inode new number of %pU\n",
+		     get_khandle_from_ino(inode));
+
+	d_instantiate_new(dentry, inode);
+	orangefs_set_timeout(dentry);
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Inode (Symlink) %pU -> %pd\n",
+		     get_khandle_from_ino(inode),
+		     dentry);
+
+	memset(&iattr, 0, sizeof iattr);
+	iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+	iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
+	__orangefs_setattr(dir, &iattr);
+	ret = 0;
+out:
+	op_release(new_op);
+	return ret;
+}
+
+static struct dentry *orangefs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				     struct dentry *dentry, umode_t mode)
+{
+	struct orangefs_inode_s *parent = ORANGEFS_I(dir);
+	struct orangefs_kernel_op_s *new_op;
+	struct orangefs_object_kref ref;
+	struct inode *inode;
+	struct iattr iattr;
+	int ret;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_MKDIR);
+	if (!new_op)
+		return ERR_PTR(-ENOMEM);
+
+	new_op->upcall.req.mkdir.parent_refn = parent->refn;
+
+	fill_default_sys_attrs(new_op->upcall.req.mkdir.attributes, mode);
+
+	strscpy(new_op->upcall.req.mkdir.d_name, dentry->d_name.name);
+
+	ret = service_operation(new_op, __func__, get_interruptible_flag(dir));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Mkdir Got ORANGEFS handle %pU on fsid %d\n",
+		     &new_op->downcall.resp.mkdir.refn.khandle,
+		     new_op->downcall.resp.mkdir.refn.fs_id);
+
+	if (ret < 0) {
+		gossip_debug(GOSSIP_NAME_DEBUG,
+			     "%s: failed with error code %d\n",
+			     __func__, ret);
+		goto out;
+	}
+
+	ref = new_op->downcall.resp.mkdir.refn;
+
+	inode = orangefs_new_inode(dir->i_sb, dir, mode, 0, &ref);
+	if (IS_ERR(inode)) {
+		gossip_err("*** Failed to allocate orangefs dir inode\n");
+		ret = PTR_ERR(inode);
+		goto out;
+	}
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Assigned dir inode new number of %pU\n",
+		     get_khandle_from_ino(inode));
+
+	d_instantiate_new(dentry, inode);
+	orangefs_set_timeout(dentry);
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "Inode (Directory) %pU -> %pd\n",
+		     get_khandle_from_ino(inode),
+		     dentry);
+
+	/*
+	 * NOTE: we have no good way to keep nlink consistent for directories
+	 * across clients; keep constant at 1.
+	 */
+	memset(&iattr, 0, sizeof iattr);
+	iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+	iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
+	__orangefs_setattr(dir, &iattr);
+out:
+	op_release(new_op);
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+static int orangefs_rename(struct mnt_idmap *idmap,
+			struct inode *old_dir,
+			struct dentry *old_dentry,
+			struct inode *new_dir,
+			struct dentry *new_dentry,
+			unsigned int flags)
+{
+	struct orangefs_kernel_op_s *new_op;
+	struct iattr iattr;
+	int ret;
+
+	if (flags)
+		return -EINVAL;
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "orangefs_rename: called (%pd2 => %pd2) ct=%d\n",
+		     old_dentry, new_dentry, d_count(new_dentry));
+
+	memset(&iattr, 0, sizeof iattr);
+	iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
+	iattr.ia_mtime = iattr.ia_ctime = current_time(new_dir);
+	__orangefs_setattr(new_dir, &iattr);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_RENAME);
+	if (!new_op)
+		return -EINVAL;
+
+	new_op->upcall.req.rename.old_parent_refn = ORANGEFS_I(old_dir)->refn;
+	new_op->upcall.req.rename.new_parent_refn = ORANGEFS_I(new_dir)->refn;
+
+	strscpy(new_op->upcall.req.rename.d_old_name, old_dentry->d_name.name);
+	strscpy(new_op->upcall.req.rename.d_new_name, new_dentry->d_name.name);
+
+	ret = service_operation(new_op,
+				"orangefs_rename",
+				get_interruptible_flag(old_dentry->d_inode));
+
+	gossip_debug(GOSSIP_NAME_DEBUG,
+		     "orangefs_rename: got downcall status %d\n",
+		     ret);
+
+	if (new_dentry->d_inode)
+		inode_set_ctime_current(d_inode(new_dentry));
+
+	op_release(new_op);
+	return ret;
+}
+
+/* ORANGEFS implementation of VFS inode operations for directories */
+const struct inode_operations orangefs_dir_inode_operations = {
+	.lookup = orangefs_lookup,
+	.get_inode_acl = orangefs_get_acl,
+	.set_acl = orangefs_set_acl,
+	.create = orangefs_create,
+	.unlink = orangefs_unlink,
+	.symlink = orangefs_symlink,
+	.mkdir = orangefs_mkdir,
+	.rmdir = orangefs_unlink,
+	.rename = orangefs_rename,
+	.setattr = orangefs_setattr,
+	.getattr = orangefs_getattr,
+	.listxattr = orangefs_listxattr,
+	.permission = orangefs_permission,
+	.update_time = orangefs_update_time,
+};
diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c
new file mode 100644
index 000000000..a557e1cf7
--- /dev/null
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -0,0 +1,836 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+struct slot_map {
+	int c;
+	wait_queue_head_t q;
+	int count;
+	unsigned long *map;
+};
+
+static struct slot_map rw_map = {
+	.c = -1,
+	.q = __WAIT_QUEUE_HEAD_INITIALIZER(rw_map.q)
+};
+static struct slot_map readdir_map = {
+	.c = -1,
+	.q = __WAIT_QUEUE_HEAD_INITIALIZER(readdir_map.q)
+};
+
+
+static void install(struct slot_map *m, int count, unsigned long *map)
+{
+	spin_lock(&m->q.lock);
+	m->c = m->count = count;
+	m->map = map;
+	wake_up_all_locked(&m->q);
+	spin_unlock(&m->q.lock);
+}
+
+static void mark_killed(struct slot_map *m)
+{
+	spin_lock(&m->q.lock);
+	m->c -= m->count + 1;
+	spin_unlock(&m->q.lock);
+}
+
+static void run_down(struct slot_map *m)
+{
+	DEFINE_WAIT(wait);
+	spin_lock(&m->q.lock);
+	if (m->c != -1) {
+		for (;;) {
+			if (likely(list_empty(&wait.entry)))
+				__add_wait_queue_entry_tail(&m->q, &wait);
+			set_current_state(TASK_UNINTERRUPTIBLE);
+
+			if (m->c == -1)
+				break;
+
+			spin_unlock(&m->q.lock);
+			schedule();
+			spin_lock(&m->q.lock);
+		}
+		__remove_wait_queue(&m->q, &wait);
+		__set_current_state(TASK_RUNNING);
+	}
+	m->map = NULL;
+	spin_unlock(&m->q.lock);
+}
+
+static void put(struct slot_map *m, int slot)
+{
+	int v;
+	spin_lock(&m->q.lock);
+	__clear_bit(slot, m->map);
+	v = ++m->c;
+	if (v > 0)
+		wake_up_locked(&m->q);
+	if (unlikely(v == -1))     /* finished dying */
+		wake_up_all_locked(&m->q);
+	spin_unlock(&m->q.lock);
+}
+
+static int wait_for_free(struct slot_map *m)
+{
+	long left = slot_timeout_secs * HZ;
+	DEFINE_WAIT(wait);
+
+	do {
+		long n = left, t;
+		if (likely(list_empty(&wait.entry)))
+			__add_wait_queue_entry_tail_exclusive(&m->q, &wait);
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (m->c > 0)
+			break;
+
+		if (m->c < 0) {
+			/* we are waiting for map to be installed */
+			/* it would better be there soon, or we go away */
+			if (n > ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ)
+				n = ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ;
+		}
+		spin_unlock(&m->q.lock);
+		t = schedule_timeout(n);
+		spin_lock(&m->q.lock);
+		if (unlikely(!t) && n != left && m->c < 0)
+			left = t;
+		else
+			left = t + (left - n);
+		if (signal_pending(current))
+			left = -EINTR;
+	} while (left > 0);
+
+	if (!list_empty(&wait.entry))
+		list_del(&wait.entry);
+	else if (left <= 0 && waitqueue_active(&m->q))
+		__wake_up_locked_key(&m->q, TASK_INTERRUPTIBLE, NULL);
+	__set_current_state(TASK_RUNNING);
+
+	if (likely(left > 0))
+		return 0;
+
+	return left < 0 ? -EINTR : -ETIMEDOUT;
+}
+
+static int get(struct slot_map *m)
+{
+	int res = 0;
+	spin_lock(&m->q.lock);
+	if (unlikely(m->c <= 0))
+		res = wait_for_free(m);
+	if (likely(!res)) {
+		m->c--;
+		res = find_first_zero_bit(m->map, m->count);
+		__set_bit(res, m->map);
+	}
+	spin_unlock(&m->q.lock);
+	return res;
+}
+
+/* used to describe mapped buffers */
+struct orangefs_bufmap_desc {
+	void __user *uaddr;		/* user space address pointer */
+	struct folio **folio_array;
+	/*
+	 * folio_offsets could be needed when userspace sets custom
+	 * sizes in user_desc, or when folios aren't all backed by
+	 * 2MB THPs.
+	 */
+	size_t *folio_offsets;
+	int folio_count;
+	bool is_two_2mib_chunks;
+};
+
+static struct orangefs_bufmap {
+	int desc_size;
+	int desc_shift;
+	int desc_count;
+	int total_size;
+	int page_count;
+	int folio_count;
+
+	struct page **page_array;
+	struct folio **folio_array;
+	struct orangefs_bufmap_desc *desc_array;
+
+	/* array to track usage of buffer descriptors */
+	unsigned long *buffer_index_array;
+
+	/* array to track usage of buffer descriptors for readdir */
+#define N DIV_ROUND_UP(ORANGEFS_READDIR_DEFAULT_DESC_COUNT, BITS_PER_LONG)
+	unsigned long readdir_index_array[N];
+#undef N
+} *__orangefs_bufmap;
+
+static DEFINE_SPINLOCK(orangefs_bufmap_lock);
+
+static void
+orangefs_bufmap_unmap(struct orangefs_bufmap *bufmap)
+{
+	unpin_user_pages(bufmap->page_array, bufmap->page_count);
+}
+
+static void
+orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
+{
+	int i;
+
+	if (!bufmap)
+		return;
+
+	for (i = 0; i < bufmap->desc_count; i++) {
+		kfree(bufmap->desc_array[i].folio_array);
+		kfree(bufmap->desc_array[i].folio_offsets);
+		bufmap->desc_array[i].folio_array = NULL;
+		bufmap->desc_array[i].folio_offsets = NULL;
+	}
+	kfree(bufmap->page_array);
+	kfree(bufmap->desc_array);
+	bitmap_free(bufmap->buffer_index_array);
+	kfree(bufmap);
+}
+
+/*
+ * XXX: Can the size and shift change while the caller gives up the
+ * XXX: lock between calling this and doing something useful?
+ */
+
+int orangefs_bufmap_size_query(void)
+{
+	struct orangefs_bufmap *bufmap;
+	int size = 0;
+	spin_lock(&orangefs_bufmap_lock);
+	bufmap = __orangefs_bufmap;
+	if (bufmap)
+		size = bufmap->desc_size;
+	spin_unlock(&orangefs_bufmap_lock);
+	return size;
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(bufmap_waitq);
+static DECLARE_WAIT_QUEUE_HEAD(readdir_waitq);
+
+static struct orangefs_bufmap *
+orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
+{
+	struct orangefs_bufmap *bufmap;
+
+	bufmap = kzalloc_obj(*bufmap);
+	if (!bufmap)
+		goto out;
+
+	bufmap->total_size = user_desc->total_size;
+	bufmap->desc_count = user_desc->count;
+	bufmap->desc_size = user_desc->size;
+	bufmap->desc_shift = ilog2(bufmap->desc_size);
+	bufmap->page_count = bufmap->total_size / PAGE_SIZE;
+
+	bufmap->buffer_index_array =
+		bitmap_zalloc(bufmap->desc_count, GFP_KERNEL);
+	if (!bufmap->buffer_index_array)
+		goto out_free_bufmap;
+
+	bufmap->desc_array =
+		kzalloc_objs(struct orangefs_bufmap_desc, bufmap->desc_count);
+	if (!bufmap->desc_array)
+		goto out_free_index_array;
+
+	/* allocate storage to track our page mappings */
+	bufmap->page_array =
+		kzalloc_objs(struct page *, bufmap->page_count);
+	if (!bufmap->page_array)
+		goto out_free_desc_array;
+
+	/* allocate folio array. */
+	bufmap->folio_array = kzalloc_objs(struct folio *, bufmap->page_count);
+	if (!bufmap->folio_array)
+		goto out_free_page_array;
+
+	return bufmap;
+
+out_free_page_array:
+	kfree(bufmap->page_array);
+out_free_desc_array:
+	kfree(bufmap->desc_array);
+out_free_index_array:
+	bitmap_free(bufmap->buffer_index_array);
+out_free_bufmap:
+	kfree(bufmap);
+out:
+	return NULL;
+}
+
+static int orangefs_bufmap_group_folios(struct orangefs_bufmap *bufmap)
+{
+	int i = 0;
+	int f = 0;
+	int k;
+	int num_pages;
+	struct page *page;
+	struct folio *folio;
+
+	while (i < bufmap->page_count) {
+		page = bufmap->page_array[i];
+		folio = page_folio(page);
+		num_pages = folio_nr_pages(folio);
+		gossip_debug(GOSSIP_BUFMAP_DEBUG,
+			"%s: i:%d: num_pages:%d: \n", __func__, i, num_pages);
+
+		for (k = 1; k < num_pages; k++) {
+			if (bufmap->page_array[i + k] != folio_page(folio, k)) {
+				gossip_err("%s: bad match,  i:%d: k:%d:\n",
+					__func__, i, k);
+				return -EINVAL;
+			}
+		}
+
+		bufmap->folio_array[f++] = folio;
+		i += num_pages;
+	}
+
+	bufmap->folio_count = f;
+	pr_info("%s: Grouped %d folios from %d pages.\n",
+		__func__,
+		bufmap->folio_count,
+		bufmap->page_count);
+	return 0;
+}
+
+static int orangefs_bufmap_map(struct orangefs_bufmap *bufmap,
+				struct ORANGEFS_dev_map_desc *user_desc)
+{
+	int pages_per_desc = bufmap->desc_size / PAGE_SIZE;
+	int ret;
+	int i;
+	int j;
+	int current_folio;
+	int desc_pages_needed;
+	int desc_folio_count;
+	int remaining_pages;
+	int need_avail_min;
+	int pages_assigned_to_this_desc;
+	int allocated_descs = 0;
+	size_t current_offset;
+	size_t adjust_offset;
+	struct folio *folio;
+
+	/* map the pages */
+	ret = pin_user_pages_fast((unsigned long)user_desc->ptr,
+		bufmap->page_count,
+		FOLL_WRITE,
+		bufmap->page_array);
+
+	if (ret < 0)
+		return ret;
+
+	if (ret != bufmap->page_count) {
+		gossip_err("orangefs error: asked for %d pages, only got %d.\n",
+				bufmap->page_count, ret);
+		for (i = 0; i < ret; i++)
+			unpin_user_page(bufmap->page_array[i]);
+		return -ENOMEM;
+	}
+
+	/*
+	 * ideally we want to get kernel space pointers for each page, but
+	 * we can't kmap that many pages at once if highmem is being used.
+	 * so instead, we just kmap/kunmap the page address each time the
+	 * kaddr is needed.
+	 */
+	for (i = 0; i < bufmap->page_count; i++)
+		flush_dcache_page(bufmap->page_array[i]);
+
+	/*
+	 * Group pages into folios.
+	 */
+	ret = orangefs_bufmap_group_folios(bufmap);
+	if (ret)
+		goto unpin;
+
+	pr_info("%s: desc_size=%d bytes (%d pages per desc), total folios=%d\n",
+			__func__, bufmap->desc_size, pages_per_desc,
+			bufmap->folio_count);
+
+	current_folio = 0;
+	remaining_pages = 0;
+	current_offset = 0;
+	for (i = 0; i < bufmap->desc_count; i++) {
+		desc_pages_needed = pages_per_desc;
+		desc_folio_count = 0;
+		pages_assigned_to_this_desc = 0;
+		bufmap->desc_array[i].is_two_2mib_chunks = false;
+
+		/*
+		 * We hope there was enough memory that each desc is
+		 * covered by two THPs/folios, if not we want to keep on
+		 * working even if there's only one page per folio.
+		 */
+		bufmap->desc_array[i].folio_array =
+			kzalloc_objs(struct folio *, pages_per_desc);
+		if (!bufmap->desc_array[i].folio_array) {
+			ret = -ENOMEM;
+			goto unpin;
+		}
+
+		bufmap->desc_array[i].folio_offsets =
+			kzalloc_objs(size_t, pages_per_desc);
+		if (!bufmap->desc_array[i].folio_offsets) {
+			ret = -ENOMEM;
+			kfree(bufmap->desc_array[i].folio_array);
+			bufmap->desc_array[i].folio_array = NULL;
+			goto unpin;
+		}
+
+		bufmap->desc_array[i].uaddr =
+			user_desc->ptr + (size_t)i * bufmap->desc_size;
+
+		/*
+		 * Accumulate folios until desc is full.
+		 */
+		while (desc_pages_needed > 0) {
+			if (remaining_pages == 0) {
+				/* shouldn't happen. */
+				if (current_folio >= bufmap->folio_count) {
+					ret = -EINVAL;
+					goto unpin;
+				}
+				folio = bufmap->folio_array[current_folio++];
+				remaining_pages = folio_nr_pages(folio);
+				current_offset = 0;
+			} else {
+				folio = bufmap->folio_array[current_folio - 1];
+			}
+
+			need_avail_min =
+				min(desc_pages_needed, remaining_pages);
+			adjust_offset = need_avail_min * PAGE_SIZE;
+
+			bufmap->desc_array[i].folio_array[desc_folio_count] =
+				folio;
+			bufmap->desc_array[i].folio_offsets[desc_folio_count] =
+				current_offset;
+			desc_folio_count++;
+			pages_assigned_to_this_desc += need_avail_min;
+			desc_pages_needed -= need_avail_min;
+			remaining_pages -= need_avail_min;
+			current_offset += adjust_offset;
+		}
+
+		/* Detect optimal case: two 2MiB folios per 4MiB slot. */
+		if (desc_folio_count == 2 &&
+		  folio_nr_pages(bufmap->desc_array[i].folio_array[0]) == 512 &&
+		  folio_nr_pages(bufmap->desc_array[i].folio_array[1]) == 512) {
+			bufmap->desc_array[i].is_two_2mib_chunks = true;
+			gossip_debug(GOSSIP_BUFMAP_DEBUG, "%s: descriptor :%d: "
+				"optimal folio/page ratio.\n", __func__, i);
+		}
+
+		bufmap->desc_array[i].folio_count = desc_folio_count;
+		gossip_debug(GOSSIP_BUFMAP_DEBUG,
+			" descriptor %d: folio_count=%d, "
+			"pages_assigned=%d (should be %d)\n",
+			i, desc_folio_count, pages_assigned_to_this_desc,
+			pages_per_desc);
+
+		allocated_descs = i + 1;
+	}
+
+	return 0;
+unpin:
+	/*
+	 * rollback any allocations we got so far...
+	 * Memory pressure, like in generic/340, led me
+	 * to write the rollback this way.
+	 */
+	for (j = 0; j < allocated_descs; j++) {
+		if (bufmap->desc_array[j].folio_array) {
+			kfree(bufmap->desc_array[j].folio_array);
+			bufmap->desc_array[j].folio_array = NULL;
+		}
+		if (bufmap->desc_array[j].folio_offsets) {
+			kfree(bufmap->desc_array[j].folio_offsets);
+			bufmap->desc_array[j].folio_offsets = NULL;
+		}
+	}
+	unpin_user_pages(bufmap->page_array, bufmap->page_count);
+	return ret;
+}
+
+/*
+ * orangefs_bufmap_initialize()
+ *
+ * initializes the mapped buffer interface
+ *
+ * user_desc is the parameters provided by userspace for the bufmap.
+ *
+ * returns 0 on success, -errno on failure
+ */
+int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc)
+{
+	struct orangefs_bufmap *bufmap;
+	int ret = -EINVAL;
+
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		     "%s: called (ptr (" "%p) sz (%d) cnt(%d).\n",
+		     __func__,
+		     user_desc->ptr,
+		     user_desc->size,
+		     user_desc->count);
+
+	if (user_desc->total_size < 0 ||
+	    user_desc->size < 0 ||
+	    user_desc->count < 0)
+		goto out;
+
+	/*
+	 * sanity check alignment and size of buffer that caller wants to
+	 * work with
+	 */
+	if (PAGE_ALIGN((unsigned long)user_desc->ptr) !=
+	    (unsigned long)user_desc->ptr) {
+		gossip_err("orangefs error: memory alignment (front). %p\n",
+			   user_desc->ptr);
+		goto out;
+	}
+
+	if (PAGE_ALIGN(((unsigned long)user_desc->ptr + user_desc->total_size))
+	    != (unsigned long)(user_desc->ptr + user_desc->total_size)) {
+		gossip_err("orangefs error: memory alignment (back).(%p + %d)\n",
+			   user_desc->ptr,
+			   user_desc->total_size);
+		goto out;
+	}
+
+	if (user_desc->total_size != (user_desc->size * user_desc->count)) {
+		gossip_err("orangefs error: user provided an oddly sized buffer: (%d, %d, %d)\n",
+			   user_desc->total_size,
+			   user_desc->size,
+			   user_desc->count);
+		goto out;
+	}
+
+	if ((user_desc->size % PAGE_SIZE) != 0) {
+		gossip_err("orangefs error: bufmap size not page size divisible (%d).\n",
+			   user_desc->size);
+		goto out;
+	}
+
+	ret = -ENOMEM;
+	bufmap = orangefs_bufmap_alloc(user_desc);
+	if (!bufmap)
+		goto out;
+
+	ret = orangefs_bufmap_map(bufmap, user_desc);
+	if (ret)
+		goto out_free_bufmap;
+
+
+	spin_lock(&orangefs_bufmap_lock);
+	if (__orangefs_bufmap) {
+		spin_unlock(&orangefs_bufmap_lock);
+		gossip_err("orangefs: error: bufmap already initialized.\n");
+		ret = -EINVAL;
+		goto out_unmap_bufmap;
+	}
+	__orangefs_bufmap = bufmap;
+	install(&rw_map,
+		bufmap->desc_count,
+		bufmap->buffer_index_array);
+	install(&readdir_map,
+		ORANGEFS_READDIR_DEFAULT_DESC_COUNT,
+		bufmap->readdir_index_array);
+	spin_unlock(&orangefs_bufmap_lock);
+
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		     "%s: exiting normally\n", __func__);
+	return 0;
+
+out_unmap_bufmap:
+	orangefs_bufmap_unmap(bufmap);
+out_free_bufmap:
+	orangefs_bufmap_free(bufmap);
+out:
+	return ret;
+}
+
+/*
+ * orangefs_bufmap_finalize()
+ *
+ * shuts down the mapped buffer interface and releases any resources
+ * associated with it
+ *
+ * no return value
+ */
+void orangefs_bufmap_finalize(void)
+{
+	struct orangefs_bufmap *bufmap = __orangefs_bufmap;
+	if (!bufmap)
+		return;
+	gossip_debug(GOSSIP_BUFMAP_DEBUG, "orangefs_bufmap_finalize: called\n");
+	mark_killed(&rw_map);
+	mark_killed(&readdir_map);
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		     "orangefs_bufmap_finalize: exiting normally\n");
+}
+
+void orangefs_bufmap_run_down(void)
+{
+	struct orangefs_bufmap *bufmap = __orangefs_bufmap;
+	if (!bufmap)
+		return;
+	run_down(&rw_map);
+	run_down(&readdir_map);
+	spin_lock(&orangefs_bufmap_lock);
+	__orangefs_bufmap = NULL;
+	spin_unlock(&orangefs_bufmap_lock);
+	orangefs_bufmap_unmap(bufmap);
+	orangefs_bufmap_free(bufmap);
+}
+
+/*
+ * orangefs_bufmap_get()
+ *
+ * gets a free mapped buffer descriptor, will sleep until one becomes
+ * available if necessary
+ *
+ * returns slot on success, -errno on failure
+ */
+int orangefs_bufmap_get(void)
+{
+	return get(&rw_map);
+}
+
+/*
+ * orangefs_bufmap_put()
+ *
+ * returns a mapped buffer descriptor to the collection
+ *
+ * no return value
+ */
+void orangefs_bufmap_put(int buffer_index)
+{
+	put(&rw_map, buffer_index);
+}
+
+/*
+ * orangefs_readdir_index_get()
+ *
+ * gets a free descriptor, will sleep until one becomes
+ * available if necessary.
+ * Although the readdir buffers are not mapped into kernel space
+ * we could do that at a later point of time. Regardless, these
+ * indices are used by the client-core.
+ *
+ * returns slot on success, -errno on failure
+ */
+int orangefs_readdir_index_get(void)
+{
+	return get(&readdir_map);
+}
+
+void orangefs_readdir_index_put(int buffer_index)
+{
+	put(&readdir_map, buffer_index);
+}
+
+/*
+ * we've been handed an iovec, we need to copy it to
+ * the shared memory descriptor at "buffer_index".
+ */
+int orangefs_bufmap_copy_from_iovec(struct iov_iter *iter,
+				int buffer_index,
+				size_t size)
+{
+	struct orangefs_bufmap_desc *to;
+	size_t remaining = size;
+	int folio_index = 0;
+	struct folio *folio;
+	size_t folio_offset;
+	size_t folio_avail;
+	size_t copy_amount;
+	size_t copied;
+	void *kaddr;
+	size_t half;
+	size_t first;
+	size_t second;
+
+	to = &__orangefs_bufmap->desc_array[buffer_index];
+
+	/* shouldn't happen... */
+	if (size > 4194304)
+		pr_info("%s: size:%zu\n", __func__, size);
+
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		"%s: buffer_index:%d size:%zu folio_count:%d\n",
+		__func__,
+		buffer_index,
+		size,
+		to->folio_count);
+
+	/* Fast path: exactly two 2 MiB folios */
+	if (to->is_two_2mib_chunks && size <= 4194304) {
+		gossip_debug(GOSSIP_BUFMAP_DEBUG,
+			"%s: fastpath hit.\n", __func__);
+		half = 2097152;		/* 2 MiB */
+		first = min(size, half);
+		second = (size > half) ? size - half : 0;
+
+		/* First 2 MiB chunk */
+		kaddr = kmap_local_folio(to->folio_array[0], 0);
+		copied = copy_from_iter(kaddr, first, iter);
+		kunmap_local(kaddr);
+		if (copied != first)
+			return -EFAULT;
+
+		if (second == 0)
+			return 0;
+
+		/* Second 2 MiB chunk */
+		kaddr = kmap_local_folio(to->folio_array[1], 0);
+		copied = copy_from_iter(kaddr, second, iter);
+		kunmap_local(kaddr);
+		if (copied != second)
+			return -EFAULT;
+
+		return 0;
+	}
+
+	while (remaining > 0) {
+
+		if (unlikely(folio_index >= to->folio_count ||
+			to->folio_array[folio_index] == NULL)) {
+				gossip_err("%s: "
+				   "folio_index:%d: >= folio_count:%d: "
+		                   "(size %zu, buffer %d)\n",
+					__func__,
+					folio_index,
+					to->folio_count,
+					size,
+					buffer_index);
+				return -EFAULT;
+		}
+
+		folio = to->folio_array[folio_index];
+		folio_offset = to->folio_offsets[folio_index];
+		folio_avail = folio_nr_pages(folio) * PAGE_SIZE - folio_offset;
+		copy_amount = min(remaining, folio_avail);
+		kaddr = kmap_local_folio(folio, folio_offset);
+		copied = copy_from_iter(kaddr, copy_amount, iter);
+		kunmap_local(kaddr);
+
+		if (copied != copy_amount)
+			return -EFAULT;
+
+		remaining -= copied;
+		folio_index++;
+	}
+
+	return 0;
+}
+
+/*
+ * we've been handed an iovec, we need to fill it from
+ * the shared memory descriptor at "buffer_index".
+ */
+int orangefs_bufmap_copy_to_iovec(struct iov_iter *iter,
+				    int buffer_index,
+				    size_t size)
+{
+	struct orangefs_bufmap_desc *from;
+	size_t remaining = size;
+	int folio_index = 0;
+	struct folio *folio;
+	size_t folio_offset;
+	size_t folio_avail;
+	size_t copy_amount;
+	size_t copied;
+	void *kaddr;
+	size_t half;
+	size_t first;
+	size_t second;
+
+	from = &__orangefs_bufmap->desc_array[buffer_index];
+
+	/* shouldn't happen... */
+	if (size > 4194304)
+		pr_info("%s: size:%zu\n", __func__, size);
+
+	gossip_debug(GOSSIP_BUFMAP_DEBUG,
+		"%s: buffer_index:%d size:%zu folio_count:%d\n",
+		__func__,
+		buffer_index,
+		size,
+		from->folio_count);
+
+	/* Fast path: exactly two 2 MiB folios */
+	if (from->is_two_2mib_chunks && size <= 4194304) {
+		gossip_debug(GOSSIP_BUFMAP_DEBUG,
+			"%s: fastpath hit.\n", __func__);
+		half = 2097152;		/* 2 MiB */
+		first = min(size, half);
+		second = (size > half) ? size - half : 0;
+		void *kaddr;
+		size_t copied;
+
+		/* First 2 MiB chunk */
+		kaddr = kmap_local_folio(from->folio_array[0], 0);
+		copied = copy_to_iter(kaddr, first, iter);
+		kunmap_local(kaddr);
+		if (copied != first)
+			return -EFAULT;
+
+		if (second == 0)
+			return 0;
+
+		/* Second 2 MiB chunk */
+		kaddr = kmap_local_folio(from->folio_array[1], 0);
+		copied = copy_to_iter(kaddr, second, iter);
+		kunmap_local(kaddr);
+		if (copied != second)
+			return -EFAULT;
+
+		return 0;
+	}
+
+	while (remaining > 0) {
+
+		if (unlikely(folio_index >= from->folio_count ||
+			from->folio_array[folio_index] == NULL)) {
+				gossip_err("%s: "
+				   "folio_index:%d: >= folio_count:%d: "
+		                   "(size %zu, buffer %d)\n",
+					__func__,
+					folio_index,
+					from->folio_count,
+					size,
+					buffer_index);
+				return -EFAULT;
+		}
+
+		folio = from->folio_array[folio_index];
+		folio_offset = from->folio_offsets[folio_index];
+		folio_avail = folio_nr_pages(folio) * PAGE_SIZE - folio_offset;
+		copy_amount = min(remaining, folio_avail);
+
+		kaddr = kmap_local_folio(folio, folio_offset);
+		copied = copy_to_iter(kaddr, copy_amount, iter);
+		kunmap_local(kaddr);
+
+		if (copied != copy_amount)
+			return -EFAULT;
+
+		remaining -= copied;
+		folio_index++;
+	}
+
+	return 0;
+}
diff --git a/fs/orangefs/orangefs-bufmap.h b/fs/orangefs/orangefs-bufmap.h
new file mode 100644
index 000000000..4231175cc
--- /dev/null
+++ b/fs/orangefs/orangefs-bufmap.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#ifndef __ORANGEFS_BUFMAP_H
+#define __ORANGEFS_BUFMAP_H
+
+int orangefs_bufmap_size_query(void);
+
+int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc);
+
+void orangefs_bufmap_finalize(void);
+
+void orangefs_bufmap_run_down(void);
+
+int orangefs_bufmap_get(void);
+
+void orangefs_bufmap_put(int buffer_index);
+
+int orangefs_readdir_index_get(void);
+
+void orangefs_readdir_index_put(int buffer_index);
+
+int orangefs_bufmap_copy_from_iovec(struct iov_iter *iter,
+				int buffer_index,
+				size_t size);
+
+int orangefs_bufmap_copy_to_iovec(struct iov_iter *iter,
+			      int buffer_index,
+			      size_t size);
+
+
+#endif /* __ORANGEFS_BUFMAP_H */
diff --git a/fs/orangefs/orangefs-cache.c b/fs/orangefs/orangefs-cache.c
new file mode 100644
index 000000000..0bdb99e89
--- /dev/null
+++ b/fs/orangefs/orangefs-cache.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+
+/* tags assigned to kernel upcall operations */
+static __u64 next_tag_value;
+static DEFINE_SPINLOCK(next_tag_value_lock);
+
+/* the orangefs memory caches */
+
+/* a cache for orangefs upcall/downcall operations */
+static struct kmem_cache *op_cache;
+
+int op_cache_initialize(void)
+{
+	op_cache = kmem_cache_create_usercopy("orangefs_op_cache",
+				     sizeof(struct orangefs_kernel_op_s),
+				     0,
+				     0,
+					 offsetof(struct orangefs_kernel_op_s, tag),
+					 offsetof(struct orangefs_kernel_op_s, upcall) +
+					     sizeof(struct orangefs_upcall_s) -
+						 offsetof(struct orangefs_kernel_op_s, tag),
+				     NULL);
+
+	if (!op_cache) {
+		gossip_err("Cannot create orangefs_op_cache\n");
+		return -ENOMEM;
+	}
+
+	/* initialize our atomic tag counter */
+	spin_lock(&next_tag_value_lock);
+	next_tag_value = 100;
+	spin_unlock(&next_tag_value_lock);
+	return 0;
+}
+
+int op_cache_finalize(void)
+{
+	kmem_cache_destroy(op_cache);
+	return 0;
+}
+
+char *get_opname_string(struct orangefs_kernel_op_s *new_op)
+{
+	if (new_op) {
+		__s32 type = new_op->upcall.type;
+
+		if (type == ORANGEFS_VFS_OP_FILE_IO)
+			return "OP_FILE_IO";
+		else if (type == ORANGEFS_VFS_OP_LOOKUP)
+			return "OP_LOOKUP";
+		else if (type == ORANGEFS_VFS_OP_CREATE)
+			return "OP_CREATE";
+		else if (type == ORANGEFS_VFS_OP_GETATTR)
+			return "OP_GETATTR";
+		else if (type == ORANGEFS_VFS_OP_REMOVE)
+			return "OP_REMOVE";
+		else if (type == ORANGEFS_VFS_OP_MKDIR)
+			return "OP_MKDIR";
+		else if (type == ORANGEFS_VFS_OP_READDIR)
+			return "OP_READDIR";
+		else if (type == ORANGEFS_VFS_OP_READDIRPLUS)
+			return "OP_READDIRPLUS";
+		else if (type == ORANGEFS_VFS_OP_SETATTR)
+			return "OP_SETATTR";
+		else if (type == ORANGEFS_VFS_OP_SYMLINK)
+			return "OP_SYMLINK";
+		else if (type == ORANGEFS_VFS_OP_RENAME)
+			return "OP_RENAME";
+		else if (type == ORANGEFS_VFS_OP_STATFS)
+			return "OP_STATFS";
+		else if (type == ORANGEFS_VFS_OP_TRUNCATE)
+			return "OP_TRUNCATE";
+		else if (type == ORANGEFS_VFS_OP_RA_FLUSH)
+			return "OP_RA_FLUSH";
+		else if (type == ORANGEFS_VFS_OP_FS_MOUNT)
+			return "OP_FS_MOUNT";
+		else if (type == ORANGEFS_VFS_OP_FS_UMOUNT)
+			return "OP_FS_UMOUNT";
+		else if (type == ORANGEFS_VFS_OP_GETXATTR)
+			return "OP_GETXATTR";
+		else if (type == ORANGEFS_VFS_OP_SETXATTR)
+			return "OP_SETXATTR";
+		else if (type == ORANGEFS_VFS_OP_LISTXATTR)
+			return "OP_LISTXATTR";
+		else if (type == ORANGEFS_VFS_OP_REMOVEXATTR)
+			return "OP_REMOVEXATTR";
+		else if (type == ORANGEFS_VFS_OP_PARAM)
+			return "OP_PARAM";
+		else if (type == ORANGEFS_VFS_OP_PERF_COUNT)
+			return "OP_PERF_COUNT";
+		else if (type == ORANGEFS_VFS_OP_CANCEL)
+			return "OP_CANCEL";
+		else if (type == ORANGEFS_VFS_OP_FSYNC)
+			return "OP_FSYNC";
+		else if (type == ORANGEFS_VFS_OP_FSKEY)
+			return "OP_FSKEY";
+		else if (type == ORANGEFS_VFS_OP_FEATURES)
+			return "OP_FEATURES";
+	}
+	return "OP_UNKNOWN?";
+}
+
+void orangefs_new_tag(struct orangefs_kernel_op_s *op)
+{
+	spin_lock(&next_tag_value_lock);
+	op->tag = next_tag_value++;
+	if (next_tag_value == 0)
+		next_tag_value = 100;
+	spin_unlock(&next_tag_value_lock);
+}
+
+struct orangefs_kernel_op_s *op_alloc(__s32 type)
+{
+	struct orangefs_kernel_op_s *new_op = NULL;
+
+	new_op = kmem_cache_zalloc(op_cache, GFP_KERNEL);
+	if (new_op) {
+		INIT_LIST_HEAD(&new_op->list);
+		spin_lock_init(&new_op->lock);
+		init_completion(&new_op->waitq);
+
+		new_op->upcall.type = ORANGEFS_VFS_OP_INVALID;
+		new_op->downcall.type = ORANGEFS_VFS_OP_INVALID;
+		new_op->downcall.status = -1;
+
+		new_op->op_state = OP_VFS_STATE_UNKNOWN;
+
+		/* initialize the op specific tag and upcall credentials */
+		orangefs_new_tag(new_op);
+		new_op->upcall.type = type;
+		new_op->attempts = 0;
+		gossip_debug(GOSSIP_CACHE_DEBUG,
+			     "Alloced OP (%p: %llu %s)\n",
+			     new_op,
+			     llu(new_op->tag),
+			     get_opname_string(new_op));
+
+		new_op->upcall.uid = from_kuid(&init_user_ns,
+					       current_fsuid());
+
+		new_op->upcall.gid = from_kgid(&init_user_ns,
+					       current_fsgid());
+	} else {
+		gossip_err("op_alloc: kmem_cache_zalloc failed!\n");
+	}
+	return new_op;
+}
+
+void op_release(struct orangefs_kernel_op_s *orangefs_op)
+{
+	if (orangefs_op) {
+		gossip_debug(GOSSIP_CACHE_DEBUG,
+			     "Releasing OP (%p: %llu)\n",
+			     orangefs_op,
+			     llu(orangefs_op->tag));
+		kmem_cache_free(op_cache, orangefs_op);
+	} else {
+		gossip_err("NULL pointer in op_release\n");
+	}
+}
diff --git a/fs/orangefs/orangefs-debug.h b/fs/orangefs/orangefs-debug.h
new file mode 100644
index 000000000..d4463534c
--- /dev/null
+++ b/fs/orangefs/orangefs-debug.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/* This file just defines debugging masks to be used with the gossip
+ * logging utility.  All debugging masks for ORANGEFS are kept here to make
+ * sure we don't have collisions.
+ */
+
+#ifndef __ORANGEFS_DEBUG_H
+#define __ORANGEFS_DEBUG_H
+
+#ifdef __KERNEL__
+#include <linux/types.h>
+#include <linux/kernel.h>
+#else
+#include <stdint.h>
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
+#define	GOSSIP_NO_DEBUG			(__u64)0
+
+#define GOSSIP_SUPER_DEBUG		((__u64)1 << 0)
+#define GOSSIP_INODE_DEBUG		((__u64)1 << 1)
+#define GOSSIP_FILE_DEBUG		((__u64)1 << 2)
+#define GOSSIP_DIR_DEBUG		((__u64)1 << 3)
+#define GOSSIP_UTILS_DEBUG		((__u64)1 << 4)
+#define GOSSIP_WAIT_DEBUG		((__u64)1 << 5)
+#define GOSSIP_ACL_DEBUG		((__u64)1 << 6)
+#define GOSSIP_DCACHE_DEBUG		((__u64)1 << 7)
+#define GOSSIP_DEV_DEBUG		((__u64)1 << 8)
+#define GOSSIP_NAME_DEBUG		((__u64)1 << 9)
+#define GOSSIP_BUFMAP_DEBUG		((__u64)1 << 10)
+#define GOSSIP_CACHE_DEBUG		((__u64)1 << 11)
+#define GOSSIP_DEBUGFS_DEBUG		((__u64)1 << 12)
+#define GOSSIP_XATTR_DEBUG		((__u64)1 << 13)
+#define GOSSIP_INIT_DEBUG		((__u64)1 << 14)
+#define GOSSIP_SYSFS_DEBUG		((__u64)1 << 15)
+
+#define GOSSIP_MAX_NR                 16
+#define GOSSIP_MAX_DEBUG              (((__u64)1 << GOSSIP_MAX_NR) - 1)
+
+#endif /* __ORANGEFS_DEBUG_H */
diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
new file mode 100644
index 000000000..9f94919a6
--- /dev/null
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -0,0 +1,1050 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * What:		/sys/kernel/debug/orangefs/debug-help
+ * Date:		June 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			List of client and kernel debug keywords.
+ *
+ *
+ * What:		/sys/kernel/debug/orangefs/client-debug
+ * Date:		June 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Debug setting for "the client", the userspace
+ * 			helper for the kernel module.
+ *
+ *
+ * What:		/sys/kernel/debug/orangefs/kernel-debug
+ * Date:		June 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Debug setting for the orangefs kernel module.
+ *
+ * 			Any of the keywords, or comma-separated lists
+ * 			of keywords, from debug-help can be catted to
+ * 			client-debug or kernel-debug.
+ *
+ * 			"none", "all" and "verbose" are special keywords
+ * 			for client-debug. Setting client-debug to "all"
+ * 			is kind of like trying to drink water from a
+ * 			fire hose, "verbose" triggers most of the same
+ * 			output except for the constant flow of output
+ * 			from the main wait loop.
+ *
+ * 			"none" and "all" are similar settings for kernel-debug
+ * 			no need for a "verbose".
+ */
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+
+#include <linux/uaccess.h>
+
+#include "orangefs-debugfs.h"
+#include "protocol.h"
+#include "orangefs-kernel.h"
+
+/* a private internal type */
+struct __keyword_mask_s {
+	const char *keyword;
+	__u64 mask_val;
+};
+
+/*
+ * Map all kmod keywords to kmod debug masks here. Keep this
+ * structure "packed":
+ *
+ *   "all" is always last...
+ *
+ *   keyword     mask_val     index
+ *     foo          1           0
+ *     bar          2           1
+ *     baz          4           2
+ *     qux          8           3
+ *      .           .           .
+ */
+static struct __keyword_mask_s s_kmod_keyword_mask_map[] = {
+	{"super", GOSSIP_SUPER_DEBUG},
+	{"inode", GOSSIP_INODE_DEBUG},
+	{"file", GOSSIP_FILE_DEBUG},
+	{"dir", GOSSIP_DIR_DEBUG},
+	{"utils", GOSSIP_UTILS_DEBUG},
+	{"wait", GOSSIP_WAIT_DEBUG},
+	{"acl", GOSSIP_ACL_DEBUG},
+	{"dcache", GOSSIP_DCACHE_DEBUG},
+	{"dev", GOSSIP_DEV_DEBUG},
+	{"name", GOSSIP_NAME_DEBUG},
+	{"bufmap", GOSSIP_BUFMAP_DEBUG},
+	{"cache", GOSSIP_CACHE_DEBUG},
+	{"debugfs", GOSSIP_DEBUGFS_DEBUG},
+	{"xattr", GOSSIP_XATTR_DEBUG},
+	{"init", GOSSIP_INIT_DEBUG},
+	{"sysfs", GOSSIP_SYSFS_DEBUG},
+	{"none", GOSSIP_NO_DEBUG},
+	{"all", GOSSIP_MAX_DEBUG}
+};
+
+static const int num_kmod_keyword_mask_map = (int)
+	(ARRAY_SIZE(s_kmod_keyword_mask_map));
+
+#define DEBUG_HELP_STRING_SIZE 4096
+#define HELP_STRING_UNINITIALIZED \
+	"Client Debug Keywords are unknown until the first time\n" \
+	"the client is started after boot.\n"
+#define ORANGEFS_KMOD_DEBUG_HELP_FILE "debug-help"
+#define ORANGEFS_KMOD_DEBUG_FILE "kernel-debug"
+#define ORANGEFS_CLIENT_DEBUG_FILE "client-debug"
+#define ORANGEFS_VERBOSE "verbose"
+#define ORANGEFS_ALL "all"
+
+/*
+ * An array of client_debug_mask will be built to hold debug keyword/mask
+ * values fetched from userspace.
+ */
+struct client_debug_mask {
+	char *keyword;
+	__u64 mask1;
+	__u64 mask2;
+};
+
+static void orangefs_kernel_debug_init(void);
+
+static int orangefs_debug_help_open(struct inode *, struct file *);
+static void *help_start(struct seq_file *, loff_t *);
+static void *help_next(struct seq_file *, void *, loff_t *);
+static void help_stop(struct seq_file *, void *);
+static int help_show(struct seq_file *, void *);
+
+static int orangefs_debug_open(struct inode *, struct file *);
+
+static ssize_t orangefs_debug_read(struct file *,
+				 char __user *,
+				 size_t,
+				 loff_t *);
+
+static ssize_t orangefs_debug_write(struct file *,
+				  const char __user *,
+				  size_t,
+				  loff_t *);
+
+static int orangefs_prepare_cdm_array(char *);
+static void debug_mask_to_string(void *, int);
+static void do_k_string(void *, int);
+static void do_c_string(void *, int);
+static int keyword_is_amalgam(char *);
+static int check_amalgam_keyword(void *, int);
+static void debug_string_to_mask(char *, void *, int);
+static void do_c_mask(int, char *, struct client_debug_mask **);
+static void do_k_mask(int, char *, __u64 **);
+
+static char kernel_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN] = "none";
+static char *debug_help_string;
+static char client_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN];
+static char client_debug_array_string[ORANGEFS_MAX_DEBUG_STRING_LEN];
+
+static struct dentry *client_debug_dentry;
+static struct dentry *debug_dir;
+
+static unsigned int kernel_mask_set_mod_init;
+static int orangefs_debug_disabled = 1;
+static int help_string_initialized;
+
+static const struct seq_operations help_debug_ops = {
+	.start	= help_start,
+	.next	= help_next,
+	.stop	= help_stop,
+	.show	= help_show,
+};
+
+static const struct file_operations debug_help_fops = {
+	.owner		= THIS_MODULE,
+	.open           = orangefs_debug_help_open,
+	.read           = seq_read,
+	.release        = seq_release,
+	.llseek         = seq_lseek,
+};
+
+static const struct file_operations kernel_debug_fops = {
+	.owner		= THIS_MODULE,
+	.open           = orangefs_debug_open,
+	.read           = orangefs_debug_read,
+	.write		= orangefs_debug_write,
+	.llseek         = generic_file_llseek,
+};
+
+static int client_all_index;
+static int client_verbose_index;
+
+static struct client_debug_mask *cdm_array;
+static int cdm_element_count;
+
+static struct client_debug_mask client_debug_mask;
+
+/*
+ * Used to protect data in ORANGEFS_KMOD_DEBUG_FILE and
+ * ORANGEFS_KMOD_DEBUG_FILE.
+ */
+static DEFINE_MUTEX(orangefs_debug_lock);
+
+/* Used to protect data in ORANGEFS_KMOD_DEBUG_HELP_FILE */
+static DEFINE_MUTEX(orangefs_help_file_lock);
+
+/*
+ * initialize kmod debug operations, create orangefs debugfs dir and
+ * ORANGEFS_KMOD_DEBUG_HELP_FILE.
+ */
+void orangefs_debugfs_init(int debug_mask)
+{
+	/* convert input debug mask to a 64-bit unsigned integer */
+        orangefs_gossip_debug_mask = (unsigned long long)debug_mask;
+
+	/*
+	 * set the kernel's gossip debug string; invalid mask values will
+	 * be ignored.
+	 */
+	debug_mask_to_string(&orangefs_gossip_debug_mask, 0);
+
+	/* remove any invalid values from the mask */
+	debug_string_to_mask(kernel_debug_string, &orangefs_gossip_debug_mask,
+	    0);
+
+	/*
+	 * if the mask has a non-zero value, then indicate that the mask
+	 * was set when the kernel module was loaded.  The orangefs dev ioctl
+	 * command will look at this boolean to determine if the kernel's
+	 * debug mask should be overwritten when the client-core is started.
+	 */
+	if (orangefs_gossip_debug_mask != 0)
+		kernel_mask_set_mod_init = true;
+
+	pr_info("%s: called with debug mask: :%s: :%llx:\n",
+		__func__,
+		kernel_debug_string,
+		(unsigned long long)orangefs_gossip_debug_mask);
+
+	debug_dir = debugfs_create_dir("orangefs", NULL);
+
+	debugfs_create_file(ORANGEFS_KMOD_DEBUG_HELP_FILE, 0444, debug_dir,
+			    debug_help_string, &debug_help_fops);
+
+	orangefs_debug_disabled = 0;
+
+	orangefs_kernel_debug_init();
+}
+
+/*
+ * initialize the kernel-debug file.
+ */
+static void orangefs_kernel_debug_init(void)
+{
+	static char k_buffer[ORANGEFS_MAX_DEBUG_STRING_LEN] = { };
+	size_t len =
+		strscpy(k_buffer, kernel_debug_string, sizeof(k_buffer) - 1);
+
+	if (len > 0) {
+		k_buffer[len] = '\n';
+		k_buffer[len + 1] = '\0';
+	} else {
+		strscpy(k_buffer, "none\n");
+		pr_info("%s: overflow 1!\n", __func__);
+	}
+
+	debugfs_create_file_aux_num(ORANGEFS_KMOD_DEBUG_FILE, 0444, debug_dir, k_buffer,
+			    0, &kernel_debug_fops);
+}
+
+
+void orangefs_debugfs_cleanup(void)
+{
+	debugfs_remove_recursive(debug_dir);
+	kfree(debug_help_string);
+	debug_help_string = NULL;
+}
+
+/* open ORANGEFS_KMOD_DEBUG_HELP_FILE */
+static int orangefs_debug_help_open(struct inode *inode, struct file *file)
+{
+	int rc = -ENODEV;
+	int ret;
+
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "orangefs_debug_help_open: start\n");
+
+	if (orangefs_debug_disabled)
+		goto out;
+
+	ret = seq_open(file, &help_debug_ops);
+	if (ret)
+		goto out;
+
+	((struct seq_file *)(file->private_data))->private = inode->i_private;
+
+	rc = 0;
+
+out:
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "orangefs_debug_help_open: rc:%d:\n",
+		     rc);
+	return rc;
+}
+
+/*
+ * I think start always gets called again after stop. Start
+ * needs to return NULL when it is done. The whole "payload"
+ * in this case is a single (long) string, so by the second
+ * time we get to start (pos = 1), we're done.
+ */
+static void *help_start(struct seq_file *m, loff_t *pos)
+{
+	void *payload = NULL;
+
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_start: start\n");
+
+	mutex_lock(&orangefs_help_file_lock);
+
+	if (*pos == 0)
+		payload = m->private;
+
+	return payload;
+}
+
+static void *help_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_next: start\n");
+
+	return NULL;
+}
+
+static void help_stop(struct seq_file *m, void *p)
+{
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_stop: start\n");
+	mutex_unlock(&orangefs_help_file_lock);
+}
+
+static int help_show(struct seq_file *m, void *v)
+{
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "help_show: start\n");
+
+	seq_puts(m, v);
+
+	return 0;
+}
+
+/*
+ * initialize the client-debug file.
+ */
+static void orangefs_client_debug_init(void)
+{
+	static char c_buffer[ORANGEFS_MAX_DEBUG_STRING_LEN] = { };
+	size_t len =
+		strscpy(c_buffer, client_debug_string, sizeof(c_buffer) - 1);
+
+	if (len > 0) {
+		c_buffer[len] = '\n';
+		c_buffer[len + 1] = '\0';
+	} else {
+		strscpy(c_buffer, "none\n");
+		pr_info("%s: overflow! 2\n", __func__);
+	}
+
+	client_debug_dentry = debugfs_create_file_aux_num(
+					  ORANGEFS_CLIENT_DEBUG_FILE,
+					  0444, debug_dir, c_buffer, 1,
+					  &kernel_debug_fops);
+}
+
+/* open ORANGEFS_KMOD_DEBUG_FILE or ORANGEFS_CLIENT_DEBUG_FILE.*/
+static int orangefs_debug_open(struct inode *inode, struct file *file)
+{
+	int rc = -ENODEV;
+
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "%s: orangefs_debug_disabled: %d\n",
+		     __func__,
+		     orangefs_debug_disabled);
+
+	if (orangefs_debug_disabled)
+		goto out;
+
+	rc = 0;
+	mutex_lock(&orangefs_debug_lock);
+	file->private_data = inode->i_private;
+	mutex_unlock(&orangefs_debug_lock);
+
+out:
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "orangefs_debug_open: rc: %d\n",
+		     rc);
+	return rc;
+}
+
+static ssize_t orangefs_debug_read(struct file *file,
+				 char __user *ubuf,
+				 size_t count,
+				 loff_t *ppos)
+{
+	char *buf;
+	int sprintf_ret;
+	ssize_t read_ret = -ENOMEM;
+
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG, "orangefs_debug_read: start\n");
+
+	buf = kmalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
+	if (!buf)
+		goto out;
+
+	mutex_lock(&orangefs_debug_lock);
+	sprintf_ret = scnprintf(buf, ORANGEFS_MAX_DEBUG_STRING_LEN, "%s", (char *)file->private_data);
+	mutex_unlock(&orangefs_debug_lock);
+
+	read_ret = simple_read_from_buffer(ubuf, count, ppos, buf, sprintf_ret);
+
+	kfree(buf);
+
+out:
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "orangefs_debug_read: ret: %zu\n",
+		     read_ret);
+
+	return read_ret;
+}
+
+static ssize_t orangefs_debug_write(struct file *file,
+				  const char __user *ubuf,
+				  size_t count,
+				  loff_t *ppos)
+{
+	char *buf;
+	int rc = -EFAULT;
+	size_t silly = 0;
+	char *debug_string;
+	struct orangefs_kernel_op_s *new_op = NULL;
+	struct client_debug_mask c_mask = { NULL, 0, 0 };
+	char *s;
+
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		"orangefs_debug_write: %pD\n",
+		file);
+
+	if (count == 0)
+		return 0;
+
+	/*
+	 * Thwart users who try to jamb a ridiculous number
+	 * of bytes into the debug file...
+	 */
+	if (count > ORANGEFS_MAX_DEBUG_STRING_LEN) {
+		silly = count;
+		count = ORANGEFS_MAX_DEBUG_STRING_LEN;
+	}
+
+	buf = memdup_user_nul(ubuf, count);
+	if (IS_ERR(buf)) {
+		gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+			     "%s: memdup_user_nul failed!\n",
+			     __func__);
+		rc = PTR_ERR(buf);
+		buf = NULL;
+		goto out;
+	}
+	strim(buf);
+
+	/*
+	 * Map the keyword string from userspace into a valid debug mask.
+	 * The mapping process involves mapping the human-inputted string
+	 * into a valid mask, and then rebuilding the string from the
+	 * verified valid mask.
+	 *
+	 * A service operation is required to set a new client-side
+	 * debug mask.
+	 */
+	if (!debugfs_get_aux_num(file)) {	// kernel-debug
+		debug_string_to_mask(buf, &orangefs_gossip_debug_mask, 0);
+		debug_mask_to_string(&orangefs_gossip_debug_mask, 0);
+		debug_string = kernel_debug_string;
+		gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+			     "New kernel debug string is %s\n",
+			     kernel_debug_string);
+	} else {
+		/* Can't reset client debug mask if client is not running. */
+		if (is_daemon_in_service()) {
+			pr_info("%s: Client not running :%d:\n",
+				__func__,
+				is_daemon_in_service());
+			goto out;
+		}
+
+		debug_string_to_mask(buf, &c_mask, 1);
+		debug_mask_to_string(&c_mask, 1);
+		debug_string = client_debug_string;
+
+		new_op = op_alloc(ORANGEFS_VFS_OP_PARAM);
+		if (!new_op) {
+			pr_info("%s: op_alloc failed!\n", __func__);
+			goto out;
+		}
+
+		new_op->upcall.req.param.op =
+			ORANGEFS_PARAM_REQUEST_OP_TWO_MASK_VALUES;
+		new_op->upcall.req.param.type = ORANGEFS_PARAM_REQUEST_SET;
+		memset(new_op->upcall.req.param.s_value,
+		       0,
+		       ORANGEFS_MAX_DEBUG_STRING_LEN);
+		sprintf(new_op->upcall.req.param.s_value,
+			"%llx %llx\n",
+			c_mask.mask1,
+			c_mask.mask2);
+
+		/* service_operation returns 0 on success... */
+		rc = service_operation(new_op,
+				       "orangefs_param",
+					ORANGEFS_OP_INTERRUPTIBLE);
+
+		if (rc)
+			gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+				     "%s: service_operation failed! rc:%d:\n",
+				     __func__,
+				     rc);
+
+		op_release(new_op);
+	}
+
+	mutex_lock(&orangefs_debug_lock);
+	s = file_inode(file)->i_private;
+	memset(s, 0, ORANGEFS_MAX_DEBUG_STRING_LEN);
+	sprintf(s, "%s\n", debug_string);
+	mutex_unlock(&orangefs_debug_lock);
+
+	*ppos += count;
+	if (silly)
+		rc = silly;
+	else
+		rc = count;
+
+out:
+	gossip_debug(GOSSIP_DEBUGFS_DEBUG,
+		     "orangefs_debug_write: rc: %d\n",
+		     rc);
+	kfree(buf);
+	return rc;
+}
+
+/*
+ * After obtaining a string representation of the client's debug
+ * keywords and their associated masks, this function is called to build an
+ * array of these values.
+ */
+static int orangefs_prepare_cdm_array(char *debug_array_string)
+{
+	int i;
+	int rc = -EINVAL;
+	char *cds_head = NULL;
+	char *cds_delimiter = NULL;
+	int keyword_len = 0;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);
+
+	/*
+	 * figure out how many elements the cdm_array needs.
+	 */
+	for (i = 0; i < strlen(debug_array_string); i++)
+		if (debug_array_string[i] == '\n')
+			cdm_element_count++;
+
+	if (!cdm_element_count) {
+		pr_info("No elements in client debug array string!\n");
+		goto out;
+	}
+
+	cdm_array = kzalloc_objs(*cdm_array, cdm_element_count);
+	if (!cdm_array) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	cds_head = debug_array_string;
+
+	for (i = 0; i < cdm_element_count; i++) {
+		cds_delimiter = strchr(cds_head, '\n');
+		*cds_delimiter = '\0';
+
+		cds_head = skip_spaces(cds_head);
+		keyword_len = strcspn(cds_head, " ");
+
+		cdm_array[i].keyword = kzalloc(keyword_len + 1, GFP_KERNEL);
+		if (!cdm_array[i].keyword) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		sscanf(cds_head,
+		       "%s %llx %llx",
+		       cdm_array[i].keyword,
+		       (unsigned long long *)&(cdm_array[i].mask1),
+		       (unsigned long long *)&(cdm_array[i].mask2));
+
+		if (!strcmp(cdm_array[i].keyword, ORANGEFS_VERBOSE))
+			client_verbose_index = i;
+
+		if (!strcmp(cdm_array[i].keyword, ORANGEFS_ALL))
+			client_all_index = i;
+
+		cds_head = cds_delimiter + 1;
+	}
+
+	rc = cdm_element_count;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: rc:%d:\n", __func__, rc);
+
+out:
+
+	return rc;
+
+}
+
+/*
+ * /sys/kernel/debug/orangefs/debug-help can be catted to
+ * see all the available kernel and client debug keywords.
+ *
+ * When orangefs.ko initializes, we have no idea what keywords the
+ * client supports, nor their associated masks.
+ *
+ * We pass through this function once at module-load and stamp a
+ * boilerplate "we don't know" message for the client in the
+ * debug-help file. We pass through here again when the client
+ * starts and then we can fill out the debug-help file fully.
+ *
+ * The client might be restarted any number of times between
+ * module reloads, we only build the debug-help file the first time.
+ */
+int orangefs_prepare_debugfs_help_string(int at_boot)
+{
+	char *client_title = "Client Debug Keywords:\n";
+	char *kernel_title = "Kernel Debug Keywords:\n";
+	size_t string_size =  DEBUG_HELP_STRING_SIZE;
+	size_t result_size;
+	size_t i;
+	char *new;
+	int rc = -EINVAL;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);
+
+	if (at_boot)
+		client_title = HELP_STRING_UNINITIALIZED;
+
+	/* build a new debug_help_string. */
+	new = kzalloc(DEBUG_HELP_STRING_SIZE, GFP_KERNEL);
+	if (!new) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * strlcat(dst, src, size) will append at most
+	 * "size - strlen(dst) - 1" bytes of src onto dst,
+	 * null terminating the result, and return the total
+	 * length of the string it tried to create.
+	 *
+	 * We'll just plow through here building our new debug
+	 * help string and let strlcat take care of assuring that
+	 * dst doesn't overflow.
+	 */
+	strlcat(new, client_title, string_size);
+
+	if (!at_boot) {
+
+                /*
+		 * fill the client keyword/mask array and remember
+		 * how many elements there were.
+		 */
+		cdm_element_count =
+			orangefs_prepare_cdm_array(client_debug_array_string);
+		if (cdm_element_count <= 0) {
+			kfree(new);
+			goto out;
+		}
+
+		for (i = 0; i < cdm_element_count; i++) {
+			strlcat(new, "\t", string_size);
+			strlcat(new, cdm_array[i].keyword, string_size);
+			strlcat(new, "\n", string_size);
+		}
+	}
+
+	strlcat(new, "\n", string_size);
+	strlcat(new, kernel_title, string_size);
+
+	for (i = 0; i < num_kmod_keyword_mask_map; i++) {
+		strlcat(new, "\t", string_size);
+		strlcat(new, s_kmod_keyword_mask_map[i].keyword, string_size);
+		result_size = strlcat(new, "\n", string_size);
+	}
+
+	/* See if we tried to put too many bytes into "new"... */
+	if (result_size >= string_size) {
+		kfree(new);
+		goto out;
+	}
+
+	if (at_boot) {
+		debug_help_string = new;
+	} else {
+		mutex_lock(&orangefs_help_file_lock);
+		memset(debug_help_string, 0, DEBUG_HELP_STRING_SIZE);
+		strlcat(debug_help_string, new, string_size);
+		mutex_unlock(&orangefs_help_file_lock);
+		kfree(new);
+	}
+
+	rc = 0;
+
+out:	return rc;
+
+}
+
+/*
+ * kernel = type 0
+ * client = type 1
+ */
+static void debug_mask_to_string(void *mask, int type)
+{
+	int i;
+	int len = 0;
+	char *debug_string;
+	int element_count = 0;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);
+
+	if (type) {
+		debug_string = client_debug_string;
+		element_count = cdm_element_count;
+	} else {
+		debug_string = kernel_debug_string;
+		element_count = num_kmod_keyword_mask_map;
+	}
+
+	memset(debug_string, 0, ORANGEFS_MAX_DEBUG_STRING_LEN);
+
+	/*
+	 * Some keywords, like "all" or "verbose", are amalgams of
+	 * numerous other keywords. Make a special check for those
+	 * before grinding through the whole mask only to find out
+	 * later...
+	 */
+	if (check_amalgam_keyword(mask, type))
+		goto out;
+
+	/* Build the debug string. */
+	for (i = 0; i < element_count; i++)
+		if (type)
+			do_c_string(mask, i);
+		else
+			do_k_string(mask, i);
+
+	len = strlen(debug_string);
+
+	if ((len) && (type))
+		client_debug_string[len - 1] = '\0';
+	else if (len)
+		kernel_debug_string[len - 1] = '\0';
+	else if (type)
+		strscpy(client_debug_string, "none");
+	else
+		strscpy(kernel_debug_string, "none");
+
+out:
+gossip_debug(GOSSIP_UTILS_DEBUG, "%s: string:%s:\n", __func__, debug_string);
+
+	return;
+}
+
+static void do_k_string(void *k_mask, int index)
+{
+	__u64 *mask = (__u64 *) k_mask;
+
+	if (keyword_is_amalgam((char *) s_kmod_keyword_mask_map[index].keyword))
+		goto out;
+
+	if (*mask & s_kmod_keyword_mask_map[index].mask_val) {
+		if ((strlen(kernel_debug_string) +
+		     strlen(s_kmod_keyword_mask_map[index].keyword) + 1)
+			< ORANGEFS_MAX_DEBUG_STRING_LEN) {
+				strcat(kernel_debug_string,
+				       s_kmod_keyword_mask_map[index].keyword);
+				strcat(kernel_debug_string, ",");
+			} else {
+				gossip_err("%s: overflow!\n", __func__);
+				strscpy(kernel_debug_string, ORANGEFS_ALL);
+				goto out;
+			}
+	}
+
+out:
+
+	return;
+}
+
+static void do_c_string(void *c_mask, int index)
+{
+	struct client_debug_mask *mask = (struct client_debug_mask *) c_mask;
+
+	if (keyword_is_amalgam(cdm_array[index].keyword))
+		goto out;
+
+	if ((mask->mask1 & cdm_array[index].mask1) ||
+	    (mask->mask2 & cdm_array[index].mask2)) {
+		if ((strlen(client_debug_string) +
+		     strlen(cdm_array[index].keyword) + 1)
+			< ORANGEFS_MAX_DEBUG_STRING_LEN) {
+				strcat(client_debug_string,
+				       cdm_array[index].keyword);
+				strcat(client_debug_string, ",");
+			} else {
+				gossip_err("%s: overflow!\n", __func__);
+				strscpy(client_debug_string, ORANGEFS_ALL);
+				goto out;
+			}
+	}
+out:
+	return;
+}
+
+static int keyword_is_amalgam(char *keyword)
+{
+	int rc = 0;
+
+	if ((!strcmp(keyword, ORANGEFS_ALL)) || (!strcmp(keyword, ORANGEFS_VERBOSE)))
+		rc = 1;
+
+	return rc;
+}
+
+/*
+ * kernel = type 0
+ * client = type 1
+ *
+ * return 1 if we found an amalgam.
+ */
+static int check_amalgam_keyword(void *mask, int type)
+{
+	__u64 *k_mask;
+	struct client_debug_mask *c_mask;
+	int k_all_index = num_kmod_keyword_mask_map - 1;
+	int rc = 0;
+
+	if (type) {
+		c_mask = (struct client_debug_mask *) mask;
+
+		if ((c_mask->mask1 == cdm_array[client_all_index].mask1) &&
+		    (c_mask->mask2 == cdm_array[client_all_index].mask2)) {
+			strscpy(client_debug_string, ORANGEFS_ALL);
+			rc = 1;
+			goto out;
+		}
+
+		if ((c_mask->mask1 == cdm_array[client_verbose_index].mask1) &&
+		    (c_mask->mask2 == cdm_array[client_verbose_index].mask2)) {
+			strscpy(client_debug_string, ORANGEFS_VERBOSE);
+			rc = 1;
+			goto out;
+		}
+
+	} else {
+		k_mask = (__u64 *) mask;
+
+		if (*k_mask >= s_kmod_keyword_mask_map[k_all_index].mask_val) {
+			strscpy(kernel_debug_string, ORANGEFS_ALL);
+			rc = 1;
+			goto out;
+		}
+	}
+
+out:
+
+	return rc;
+}
+
+/*
+ * kernel = type 0
+ * client = type 1
+ */
+static void debug_string_to_mask(char *debug_string, void *mask, int type)
+{
+	int i;
+	char *strsep_fodder = kstrdup(debug_string, GFP_KERNEL);
+	char *trimmed;
+	char *token;
+	char *original_pointer;
+	int element_count = 0;
+	struct client_debug_mask *c_mask = NULL;
+	__u64 *k_mask = NULL;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: start\n", __func__);
+
+	if (type) {
+		c_mask = (struct client_debug_mask *)mask;
+		element_count = cdm_element_count;
+	} else {
+		k_mask = (__u64 *)mask;
+		*k_mask = 0;
+		element_count = num_kmod_keyword_mask_map;
+	}
+
+	original_pointer = strsep_fodder;
+	while ((token = strsep(&strsep_fodder, ",")) != NULL) {
+		trimmed = strim(token);
+		if (*trimmed) {
+			for (i = 0; i < element_count; i++)
+				if (type)
+					do_c_mask(i, trimmed, &c_mask);
+				else
+					do_k_mask(i, trimmed, &k_mask);
+
+		}
+	}
+
+	kfree(original_pointer);
+}
+
+static void do_c_mask(int i, char *unchecked_keyword,
+    struct client_debug_mask **sane_mask)
+{
+
+	if (!strcmp(cdm_array[i].keyword, unchecked_keyword)) {
+		(**sane_mask).mask1 = (**sane_mask).mask1 | cdm_array[i].mask1;
+		(**sane_mask).mask2 = (**sane_mask).mask2 | cdm_array[i].mask2;
+	}
+}
+
+static void do_k_mask(int i, char *unchecked_keyword, __u64 **sane_mask)
+{
+
+	if (!strcmp(s_kmod_keyword_mask_map[i].keyword, unchecked_keyword))
+		**sane_mask = (**sane_mask) |
+				s_kmod_keyword_mask_map[i].mask_val;
+}
+
+int orangefs_debugfs_new_client_mask(void __user *arg)
+{
+	struct dev_mask2_info_s mask2_info = {0};
+	int ret;
+
+	ret = copy_from_user(&mask2_info,
+			     (void __user *)arg,
+			     sizeof(struct dev_mask2_info_s));
+
+	if (ret != 0)
+		return -EIO;
+
+	client_debug_mask.mask1 = mask2_info.mask1_value;
+	client_debug_mask.mask2 = mask2_info.mask2_value;
+
+	pr_info("%s: client debug mask has been been received "
+		":%llx: :%llx:\n",
+		__func__,
+		(unsigned long long)client_debug_mask.mask1,
+		(unsigned long long)client_debug_mask.mask2);
+
+	return ret;
+}
+
+int orangefs_debugfs_new_client_string(void __user *arg)
+{
+	int ret;
+
+	ret = copy_from_user(&client_debug_array_string,
+			     (void __user *)arg,
+			     ORANGEFS_MAX_DEBUG_STRING_LEN);
+
+	if (ret != 0) {
+		pr_info("%s: CLIENT_STRING: copy_from_user failed\n",
+			__func__);
+		return -EFAULT;
+	}
+
+	/*
+	 * The real client-core makes an effort to ensure
+	 * that actual strings that aren't too long to fit in
+	 * this buffer is what we get here. We're going to use
+	 * string functions on the stuff we got, so we'll make
+	 * this extra effort to try and keep from
+	 * flowing out of this buffer when we use the string
+	 * functions, even if somehow the stuff we end up
+	 * with here is garbage.
+	 */
+	client_debug_array_string[ORANGEFS_MAX_DEBUG_STRING_LEN - 1] =
+		'\0';
+
+	pr_info("%s: client debug array string has been received.\n",
+		__func__);
+
+	if (!help_string_initialized) {
+
+		/* Build a proper debug help string. */
+		ret = orangefs_prepare_debugfs_help_string(0);
+		if (ret) {
+			gossip_err("%s: no debug help string \n",
+				   __func__);
+			return ret;
+		}
+
+	}
+
+	debug_mask_to_string(&client_debug_mask, 1);
+
+	debugfs_remove(client_debug_dentry);
+
+	orangefs_client_debug_init();
+
+	help_string_initialized++;
+
+	return 0;
+}
+
+int orangefs_debugfs_new_debug(void __user *arg)
+{
+	struct dev_mask_info_s mask_info = {0};
+	int ret;
+
+	ret = copy_from_user(&mask_info,
+			     (void __user *)arg,
+			     sizeof(mask_info));
+
+	if (ret != 0)
+		return -EIO;
+
+	if (mask_info.mask_type == KERNEL_MASK) {
+		if ((mask_info.mask_value == 0)
+		    && (kernel_mask_set_mod_init)) {
+			/*
+			 * the kernel debug mask was set when the
+			 * kernel module was loaded; don't override
+			 * it if the client-core was started without
+			 * a value for ORANGEFS_KMODMASK.
+			 */
+			return 0;
+		}
+		debug_mask_to_string(&mask_info.mask_value,
+				     mask_info.mask_type);
+		orangefs_gossip_debug_mask = mask_info.mask_value;
+		pr_info("%s: kernel debug mask has been modified to "
+			":%s: :%llx:\n",
+			__func__,
+			kernel_debug_string,
+			(unsigned long long)orangefs_gossip_debug_mask);
+	} else if (mask_info.mask_type == CLIENT_MASK) {
+		debug_mask_to_string(&mask_info.mask_value,
+				     mask_info.mask_type);
+		pr_info("%s: client debug mask has been modified to"
+			":%s: :%llx:\n",
+			__func__,
+			client_debug_string,
+			llu(mask_info.mask_value));
+	} else {
+		gossip_err("Invalid mask type....\n");
+		return -EINVAL;
+	}
+
+	return ret;
+}
diff --git a/fs/orangefs/orangefs-debugfs.h b/fs/orangefs/orangefs-debugfs.h
new file mode 100644
index 000000000..502f6dedc
--- /dev/null
+++ b/fs/orangefs/orangefs-debugfs.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+void orangefs_debugfs_init(int);
+void orangefs_debugfs_cleanup(void);
+int orangefs_prepare_debugfs_help_string(int);
+int orangefs_debugfs_new_client_mask(void __user *);
+int orangefs_debugfs_new_client_string(void __user *);
+int orangefs_debugfs_new_debug(void __user *);
diff --git a/fs/orangefs/orangefs-dev-proto.h b/fs/orangefs/orangefs-dev-proto.h
new file mode 100644
index 000000000..dc6609824
--- /dev/null
+++ b/fs/orangefs/orangefs-dev-proto.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#ifndef _ORANGEFS_DEV_PROTO_H
+#define _ORANGEFS_DEV_PROTO_H
+
+/*
+ * types and constants shared between user space and kernel space for
+ * device interaction using a common protocol
+ */
+
+/*
+ * valid orangefs kernel operation types
+ */
+#define ORANGEFS_VFS_OP_INVALID           0xFF000000
+#define ORANGEFS_VFS_OP_FILE_IO        0xFF000001
+#define ORANGEFS_VFS_OP_LOOKUP         0xFF000002
+#define ORANGEFS_VFS_OP_CREATE         0xFF000003
+#define ORANGEFS_VFS_OP_GETATTR        0xFF000004
+#define ORANGEFS_VFS_OP_REMOVE         0xFF000005
+#define ORANGEFS_VFS_OP_MKDIR          0xFF000006
+#define ORANGEFS_VFS_OP_READDIR        0xFF000007
+#define ORANGEFS_VFS_OP_SETATTR        0xFF000008
+#define ORANGEFS_VFS_OP_SYMLINK        0xFF000009
+#define ORANGEFS_VFS_OP_RENAME         0xFF00000A
+#define ORANGEFS_VFS_OP_STATFS         0xFF00000B
+#define ORANGEFS_VFS_OP_TRUNCATE       0xFF00000C
+#define ORANGEFS_VFS_OP_RA_FLUSH       0xFF00000D
+#define ORANGEFS_VFS_OP_FS_MOUNT       0xFF00000E
+#define ORANGEFS_VFS_OP_FS_UMOUNT      0xFF00000F
+#define ORANGEFS_VFS_OP_GETXATTR       0xFF000010
+#define ORANGEFS_VFS_OP_SETXATTR          0xFF000011
+#define ORANGEFS_VFS_OP_LISTXATTR         0xFF000012
+#define ORANGEFS_VFS_OP_REMOVEXATTR       0xFF000013
+#define ORANGEFS_VFS_OP_PARAM          0xFF000014
+#define ORANGEFS_VFS_OP_PERF_COUNT     0xFF000015
+#define ORANGEFS_VFS_OP_CANCEL            0xFF00EE00
+#define ORANGEFS_VFS_OP_FSYNC          0xFF00EE01
+#define ORANGEFS_VFS_OP_FSKEY             0xFF00EE02
+#define ORANGEFS_VFS_OP_READDIRPLUS       0xFF00EE03
+#define ORANGEFS_VFS_OP_FEATURES	0xFF00EE05 /* 2.9.6 */
+
+/* features is a 64-bit unsigned bitmask */
+#define ORANGEFS_FEATURE_READAHEAD 1
+
+/*
+ * Misc constants. Please retain them as multiples of 8!
+ * Otherwise 32-64 bit interactions will be messed up :)
+ */
+#define ORANGEFS_MAX_DEBUG_STRING_LEN	0x00000800
+
+#define ORANGEFS_MAX_DIRENT_COUNT_READDIR 512
+
+#include "upcall.h"
+#include "downcall.h"
+
+#endif
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
new file mode 100644
index 000000000..1451fc2c1
--- /dev/null
+++ b/fs/orangefs/orangefs-kernel.h
@@ -0,0 +1,484 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  The ORANGEFS Linux kernel support allows ORANGEFS volumes to be mounted and
+ *  accessed through the Linux VFS (i.e. using standard I/O system calls).
+ *  This support is only needed on clients that wish to mount the file system.
+ *
+ */
+
+/*
+ *  Declarations and macros for the ORANGEFS Linux kernel support.
+ */
+
+#ifndef __ORANGEFSKERNEL_H
+#define __ORANGEFSKERNEL_H
+
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+#include <linux/statfs.h>
+#include <linux/backing-dev.h>
+#include <linux/device.h>
+#include <linux/mpage.h>
+#include <linux/namei.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/vmalloc.h>
+
+#include <linux/aio.h>
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/compat.h>
+#include <linux/mount.h>
+#include <linux/uaccess.h>
+#include <linux/atomic.h>
+#include <linux/uio.h>
+#include <linux/sched/signal.h>
+#include <linux/mm.h>
+#include <linux/wait.h>
+#include <linux/dcache.h>
+#include <linux/pagemap.h>
+#include <linux/poll.h>
+#include <linux/rwsem.h>
+#include <linux/xattr.h>
+#include <linux/exportfs.h>
+#include <linux/hashtable.h>
+
+#include <linux/unaligned.h>
+
+#include "orangefs-dev-proto.h"
+
+#define ORANGEFS_DEFAULT_OP_TIMEOUT_SECS       20
+
+#define ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS   30
+
+#define ORANGEFS_DEFAULT_SLOT_TIMEOUT_SECS     900	/* 15 minutes */
+
+#define ORANGEFS_REQDEVICE_NAME          "pvfs2-req"
+
+#define ORANGEFS_DEVREQ_MAGIC             0x20030529
+#define ORANGEFS_PURGE_RETRY_COUNT     0x00000005
+
+#define MAX_DEV_REQ_UPSIZE (2 * sizeof(__s32) +   \
+sizeof(__u64) + sizeof(struct orangefs_upcall_s))
+#define MAX_DEV_REQ_DOWNSIZE (2 * sizeof(__s32) + \
+sizeof(__u64) + sizeof(struct orangefs_downcall_s))
+
+/*
+ * valid orangefs kernel operation states
+ *
+ * unknown  - op was just initialized
+ * waiting  - op is on request_list (upward bound)
+ * inprogr  - op is in progress (waiting for downcall)
+ * serviced - op has matching downcall; ok
+ * purged   - op has to start a timer since client-core
+ *            exited uncleanly before servicing op
+ * given up - submitter has given up waiting for it
+ */
+enum orangefs_vfs_op_states {
+	OP_VFS_STATE_UNKNOWN = 0,
+	OP_VFS_STATE_WAITING = 1,
+	OP_VFS_STATE_INPROGR = 2,
+	OP_VFS_STATE_SERVICED = 4,
+	OP_VFS_STATE_PURGED = 8,
+	OP_VFS_STATE_GIVEN_UP = 16,
+};
+
+extern const struct xattr_handler * const orangefs_xattr_handlers[];
+
+extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type, bool rcu);
+extern int orangefs_set_acl(struct mnt_idmap *idmap,
+			    struct dentry *dentry, struct posix_acl *acl,
+			    int type);
+int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+
+/*
+ * orangefs data structures
+ */
+struct orangefs_kernel_op_s {
+	enum orangefs_vfs_op_states op_state;
+	__u64 tag;
+
+	/*
+	 * Set uses_shared_memory to non zero if this operation uses
+	 * shared memory. If true, then a retry on the op must also
+	 * get a new shared memory buffer and re-populate it.
+	 * Cancels don't care - it only matters for service_operation()
+	 * retry logics and cancels don't go through it anymore. It
+	 * safely stays non-zero when we use it as slot_to_free.
+	 */
+	union {
+		int uses_shared_memory;
+		int slot_to_free;
+	};
+
+	struct orangefs_upcall_s upcall;
+	struct orangefs_downcall_s downcall;
+
+	struct completion waitq;
+	spinlock_t lock;
+
+	int attempts;
+
+	struct list_head list;
+};
+
+#define set_op_state_waiting(op)     ((op)->op_state = OP_VFS_STATE_WAITING)
+#define set_op_state_inprogress(op)  ((op)->op_state = OP_VFS_STATE_INPROGR)
+#define set_op_state_given_up(op)  ((op)->op_state = OP_VFS_STATE_GIVEN_UP)
+static inline void set_op_state_serviced(struct orangefs_kernel_op_s *op)
+{
+	op->op_state = OP_VFS_STATE_SERVICED;
+	complete(&op->waitq);
+}
+
+#define op_state_waiting(op)     ((op)->op_state & OP_VFS_STATE_WAITING)
+#define op_state_in_progress(op) ((op)->op_state & OP_VFS_STATE_INPROGR)
+#define op_state_serviced(op)    ((op)->op_state & OP_VFS_STATE_SERVICED)
+#define op_state_purged(op)      ((op)->op_state & OP_VFS_STATE_PURGED)
+#define op_state_given_up(op)    ((op)->op_state & OP_VFS_STATE_GIVEN_UP)
+#define op_is_cancel(op)         ((op)->upcall.type == ORANGEFS_VFS_OP_CANCEL)
+
+void op_release(struct orangefs_kernel_op_s *op);
+
+extern void orangefs_bufmap_put(int);
+static inline void put_cancel(struct orangefs_kernel_op_s *op)
+{
+	orangefs_bufmap_put(op->slot_to_free);
+	op_release(op);
+}
+
+static inline void set_op_state_purged(struct orangefs_kernel_op_s *op)
+{
+	spin_lock(&op->lock);
+	if (unlikely(op_is_cancel(op))) {
+		list_del_init(&op->list);
+		spin_unlock(&op->lock);
+		put_cancel(op);
+	} else {
+		op->op_state |= OP_VFS_STATE_PURGED;
+		complete(&op->waitq);
+		spin_unlock(&op->lock);
+	}
+}
+
+/* per inode private orangefs info */
+struct orangefs_inode_s {
+	struct orangefs_object_kref refn;
+	char link_target[ORANGEFS_NAME_MAX];
+	/*
+	 * Reading/Writing Extended attributes need to acquire the appropriate
+	 * reader/writer semaphore on the orangefs_inode_s structure.
+	 */
+	struct rw_semaphore xattr_sem;
+
+	struct inode vfs_inode;
+	sector_t last_failed_block_index_read;
+
+	unsigned long getattr_time;
+	unsigned long mapping_time;
+	int attr_valid;
+	kuid_t attr_uid;
+	kgid_t attr_gid;
+	unsigned long bitlock;
+
+	DECLARE_HASHTABLE(xattr_cache, 4);
+};
+
+/* per superblock private orangefs info */
+struct orangefs_sb_info_s {
+	struct orangefs_khandle root_khandle;
+	__s32 fs_id;
+	int id;
+	int flags;
+#define ORANGEFS_OPT_INTR	0x01
+#define ORANGEFS_OPT_LOCAL_LOCK	0x02
+	char devname[ORANGEFS_MAX_SERVER_ADDR_LEN];
+	struct super_block *sb;
+	int mount_pending;
+	int no_list;
+	struct list_head list;
+};
+
+struct orangefs_stats {
+	unsigned long cache_hits;
+	unsigned long cache_misses;
+	unsigned long reads;
+	unsigned long writes;
+};
+
+struct orangefs_cached_xattr {
+	struct hlist_node node;
+	char key[ORANGEFS_MAX_XATTR_NAMELEN];
+	char val[ORANGEFS_MAX_XATTR_VALUELEN];
+	ssize_t length;
+	unsigned long timeout;
+};
+
+struct orangefs_write_range {
+	loff_t pos;
+	size_t len;
+	kuid_t uid;
+	kgid_t gid;
+};
+
+extern struct orangefs_stats orangefs_stats;
+
+/*
+ * NOTE: See Documentation/filesystems/porting.rst for information
+ * on implementing FOO_I and properly accessing fs private data
+ */
+static inline struct orangefs_inode_s *ORANGEFS_I(struct inode *inode)
+{
+	return container_of(inode, struct orangefs_inode_s, vfs_inode);
+}
+
+static inline struct orangefs_sb_info_s *ORANGEFS_SB(struct super_block *sb)
+{
+	return (struct orangefs_sb_info_s *) sb->s_fs_info;
+}
+
+/* ino_t descends from "unsigned long", 8 bytes, 64 bits. */
+static inline ino_t orangefs_khandle_to_ino(struct orangefs_khandle *khandle)
+{
+	union {
+		unsigned char u[8];
+		__u64 ino;
+	} ihandle;
+
+	ihandle.u[0] = khandle->u[0] ^ khandle->u[4];
+	ihandle.u[1] = khandle->u[1] ^ khandle->u[5];
+	ihandle.u[2] = khandle->u[2] ^ khandle->u[6];
+	ihandle.u[3] = khandle->u[3] ^ khandle->u[7];
+	ihandle.u[4] = khandle->u[12] ^ khandle->u[8];
+	ihandle.u[5] = khandle->u[13] ^ khandle->u[9];
+	ihandle.u[6] = khandle->u[14] ^ khandle->u[10];
+	ihandle.u[7] = khandle->u[15] ^ khandle->u[11];
+
+	return ihandle.ino;
+}
+
+static inline struct orangefs_khandle *get_khandle_from_ino(struct inode *inode)
+{
+	return &(ORANGEFS_I(inode)->refn.khandle);
+}
+
+static inline int is_root_handle(struct inode *inode)
+{
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s: root handle: %pU, this handle: %pU:\n",
+		     __func__,
+		     &ORANGEFS_SB(inode->i_sb)->root_khandle,
+		     get_khandle_from_ino(inode));
+
+	if (ORANGEFS_khandle_cmp(&(ORANGEFS_SB(inode->i_sb)->root_khandle),
+			     get_khandle_from_ino(inode)))
+		return 0;
+	else
+		return 1;
+}
+
+static inline int match_handle(struct orangefs_khandle resp_handle,
+			       struct inode *inode)
+{
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s: one handle: %pU, another handle:%pU:\n",
+		     __func__,
+		     &resp_handle,
+		     get_khandle_from_ino(inode));
+
+	if (ORANGEFS_khandle_cmp(&resp_handle, get_khandle_from_ino(inode)))
+		return 0;
+	else
+		return 1;
+}
+
+/*
+ * defined in orangefs-cache.c
+ */
+int op_cache_initialize(void);
+int op_cache_finalize(void);
+struct orangefs_kernel_op_s *op_alloc(__s32 type);
+void orangefs_new_tag(struct orangefs_kernel_op_s *op);
+char *get_opname_string(struct orangefs_kernel_op_s *new_op);
+
+int orangefs_inode_cache_initialize(void);
+int orangefs_inode_cache_finalize(void);
+
+/*
+ * defined in orangefs-mod.c
+ */
+void purge_inprogress_ops(void);
+
+/*
+ * defined in waitqueue.c
+ */
+void purge_waiting_ops(void);
+
+/*
+ * defined in super.c
+ */
+extern uint64_t orangefs_features;
+extern const struct fs_parameter_spec orangefs_fs_param_spec[];
+
+int orangefs_init_fs_context(struct fs_context *fc);
+
+void orangefs_kill_sb(struct super_block *sb);
+int orangefs_remount(struct orangefs_sb_info_s *);
+
+int fsid_key_table_initialize(void);
+void fsid_key_table_finalize(void);
+
+/*
+ * defined in inode.c
+ */
+vm_fault_t orangefs_page_mkwrite(struct vm_fault *);
+struct inode *orangefs_new_inode(struct super_block *sb,
+			      struct inode *dir,
+			      umode_t mode,
+			      dev_t dev,
+			      struct orangefs_object_kref *ref);
+
+int __orangefs_setattr(struct inode *, struct iattr *);
+int __orangefs_setattr_mode(struct dentry *dentry, struct iattr *iattr);
+int orangefs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
+
+int orangefs_getattr(struct mnt_idmap *idmap, const struct path *path,
+		     struct kstat *stat, u32 request_mask, unsigned int flags);
+
+int orangefs_permission(struct mnt_idmap *idmap,
+			struct inode *inode, int mask);
+
+int orangefs_update_time(struct inode *inode, enum fs_update_time type,
+		unsigned int flags);
+
+/*
+ * defined in xattr.c
+ */
+ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size);
+
+/*
+ * defined in namei.c
+ */
+struct inode *orangefs_iget(struct super_block *sb,
+			 struct orangefs_object_kref *ref);
+
+/*
+ * defined in devorangefs-req.c
+ */
+extern uint32_t orangefs_userspace_version;
+
+int orangefs_dev_init(void);
+void orangefs_dev_cleanup(void);
+int is_daemon_in_service(void);
+bool __is_daemon_in_service(void);
+
+/*
+ * defined in file.c
+ */
+int orangefs_revalidate_mapping(struct inode *);
+ssize_t wait_for_direct_io(enum ORANGEFS_io_type, struct inode *, loff_t *,
+    struct iov_iter *, size_t, loff_t, struct orangefs_write_range *, int *,
+    struct file *);
+ssize_t do_readv_writev(enum ORANGEFS_io_type, struct file *, loff_t *,
+    struct iov_iter *);
+
+/*
+ * defined in orangefs-utils.c
+ */
+__s32 fsid_of_op(struct orangefs_kernel_op_s *op);
+
+ssize_t orangefs_inode_getxattr(struct inode *inode,
+			     const char *name,
+			     void *buffer,
+			     size_t size);
+
+int orangefs_inode_setxattr(struct inode *inode,
+			 const char *name,
+			 const void *value,
+			 size_t size,
+			 int flags);
+
+#define ORANGEFS_GETATTR_NEW 1
+#define ORANGEFS_GETATTR_SIZE 2
+
+int orangefs_inode_getattr(struct inode *, int);
+
+int orangefs_inode_check_changed(struct inode *inode);
+
+int orangefs_inode_setattr(struct inode *inode);
+
+bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op);
+
+int orangefs_normalize_to_errno(__s32 error_code);
+
+extern struct mutex orangefs_request_mutex;
+extern int op_timeout_secs;
+extern int slot_timeout_secs;
+extern int orangefs_cache_timeout_msecs;
+extern int orangefs_dcache_timeout_msecs;
+extern int orangefs_getattr_timeout_msecs;
+extern struct list_head orangefs_superblocks;
+extern spinlock_t orangefs_superblocks_lock;
+extern struct list_head orangefs_request_list;
+extern spinlock_t orangefs_request_list_lock;
+extern wait_queue_head_t orangefs_request_list_waitq;
+extern struct list_head *orangefs_htable_ops_in_progress;
+extern spinlock_t orangefs_htable_ops_in_progress_lock;
+extern int hash_table_size;
+
+extern const struct file_operations orangefs_file_operations;
+extern const struct inode_operations orangefs_symlink_inode_operations;
+extern const struct inode_operations orangefs_dir_inode_operations;
+extern const struct file_operations orangefs_dir_operations;
+extern const struct dentry_operations orangefs_dentry_operations;
+
+/*
+ * misc convenience macros
+ */
+
+#define ORANGEFS_OP_INTERRUPTIBLE 1   /* service_operation() is interruptible */
+#define ORANGEFS_OP_PRIORITY      2   /* service_operation() is high priority */
+#define ORANGEFS_OP_CANCELLATION  4   /* this is a cancellation */
+#define ORANGEFS_OP_NO_MUTEX      8   /* don't acquire request_mutex */
+#define ORANGEFS_OP_ASYNC         16  /* Queue it, but don't wait */
+#define ORANGEFS_OP_WRITEBACK     32
+
+int service_operation(struct orangefs_kernel_op_s *op,
+		      const char *op_name,
+		      int flags);
+
+#define get_interruptible_flag(inode) \
+	((ORANGEFS_SB(inode->i_sb)->flags & ORANGEFS_OPT_INTR) ? \
+		ORANGEFS_OP_INTERRUPTIBLE : 0)
+
+#define fill_default_sys_attrs(sys_attr, mode)			\
+do {									\
+	sys_attr.owner = from_kuid(&init_user_ns, current_fsuid()); \
+	sys_attr.group = from_kgid(&init_user_ns, current_fsgid()); \
+	sys_attr.perms = ORANGEFS_util_translate_mode(mode);		\
+	sys_attr.mtime = 0;						\
+	sys_attr.atime = 0;						\
+	sys_attr.ctime = 0;						\
+	sys_attr.mask = ORANGEFS_ATTR_SYS_ALL_SETABLE;			\
+} while (0)
+
+static inline void orangefs_set_timeout(struct dentry *dentry)
+{
+	unsigned long time = jiffies + orangefs_dcache_timeout_msecs*HZ/1000;
+
+	dentry->d_fsdata = (void *) time;
+}
+
+#endif /* __ORANGEFSKERNEL_H */
diff --git a/fs/orangefs/orangefs-mod.c b/fs/orangefs/orangefs-mod.c
new file mode 100644
index 000000000..f591f0953
--- /dev/null
+++ b/fs/orangefs/orangefs-mod.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * Changes by Acxiom Corporation to add proc file handler for pvfs2 client
+ * parameters, Copyright Acxiom Corporation, 2005.
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-debugfs.h"
+#include "orangefs-sysfs.h"
+
+/* ORANGEFS_VERSION is a ./configure define */
+#ifndef ORANGEFS_VERSION
+#define ORANGEFS_VERSION "upstream"
+#endif
+
+/*
+ * global variables declared here
+ */
+
+struct orangefs_stats orangefs_stats;
+
+/* the size of the hash tables for ops in progress */
+int hash_table_size = 509;
+
+static ulong module_parm_debug_mask;
+__u64 orangefs_gossip_debug_mask;
+int op_timeout_secs = ORANGEFS_DEFAULT_OP_TIMEOUT_SECS;
+int slot_timeout_secs = ORANGEFS_DEFAULT_SLOT_TIMEOUT_SECS;
+int orangefs_cache_timeout_msecs = 500;
+int orangefs_dcache_timeout_msecs = 50;
+int orangefs_getattr_timeout_msecs = 50;
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("ORANGEFS Development Team");
+MODULE_DESCRIPTION("The Linux Kernel VFS interface to ORANGEFS");
+MODULE_PARM_DESC(module_parm_debug_mask, "debugging level (see orangefs-debug.h for values)");
+MODULE_PARM_DESC(op_timeout_secs, "Operation timeout in seconds");
+MODULE_PARM_DESC(slot_timeout_secs, "Slot timeout in seconds");
+MODULE_PARM_DESC(hash_table_size,
+		 "size of hash table for operations in progress");
+
+static struct file_system_type orangefs_fs_type = {
+	.name = "pvfs2",
+	.init_fs_context = orangefs_init_fs_context,
+	.parameters = orangefs_fs_param_spec,
+	.kill_sb = orangefs_kill_sb,
+	.owner = THIS_MODULE,
+};
+
+module_param(hash_table_size, int, 0);
+module_param(module_parm_debug_mask, ulong, 0644);
+module_param(op_timeout_secs, int, 0);
+module_param(slot_timeout_secs, int, 0);
+
+/*
+ * Blocks non-priority requests from being queued for servicing.  This
+ * could be used for protecting the request list data structure, but
+ * for now it's only being used to stall the op addition to the request
+ * list
+ */
+DEFINE_MUTEX(orangefs_request_mutex);
+
+/* hash table for storing operations waiting for matching downcall */
+struct list_head *orangefs_htable_ops_in_progress;
+DEFINE_SPINLOCK(orangefs_htable_ops_in_progress_lock);
+
+/* list for queueing upcall operations */
+LIST_HEAD(orangefs_request_list);
+
+/* used to protect the above orangefs_request_list */
+DEFINE_SPINLOCK(orangefs_request_list_lock);
+
+/* used for incoming request notification */
+DECLARE_WAIT_QUEUE_HEAD(orangefs_request_list_waitq);
+
+static int __init orangefs_init(void)
+{
+	int ret;
+	__u32 i = 0;
+
+	if (op_timeout_secs < 0)
+		op_timeout_secs = 0;
+
+	if (slot_timeout_secs < 0)
+		slot_timeout_secs = 0;
+
+	/* initialize global book keeping data structures */
+	ret = op_cache_initialize();
+	if (ret < 0)
+		goto out;
+
+	ret = orangefs_inode_cache_initialize();
+	if (ret < 0)
+		goto cleanup_op;
+
+	orangefs_htable_ops_in_progress =
+	    kzalloc_objs(struct list_head, hash_table_size);
+	if (!orangefs_htable_ops_in_progress) {
+		ret = -ENOMEM;
+		goto cleanup_inode;
+	}
+
+	/* initialize a doubly linked at each hash table index */
+	for (i = 0; i < hash_table_size; i++)
+		INIT_LIST_HEAD(&orangefs_htable_ops_in_progress[i]);
+
+	ret = fsid_key_table_initialize();
+	if (ret < 0)
+		goto cleanup_progress_table;
+
+	/*
+	 * Build the contents of /sys/kernel/debug/orangefs/debug-help
+	 * from the keywords in the kernel keyword/mask array.
+	 *
+	 * The keywords in the client keyword/mask array are
+	 * unknown at boot time.
+	 *
+	 * orangefs_prepare_debugfs_help_string will be used again
+	 * later to rebuild the debug-help-string after the client starts
+	 * and passes along the needed info. The argument signifies
+	 * which time orangefs_prepare_debugfs_help_string is being
+	 * called.
+	 */
+	ret = orangefs_prepare_debugfs_help_string(1);
+	if (ret)
+		goto cleanup_key_table;
+
+	orangefs_debugfs_init(module_parm_debug_mask);
+
+	ret = orangefs_sysfs_init();
+	if (ret)
+		goto sysfs_init_failed;
+
+	/* Initialize the orangefsdev subsystem. */
+	ret = orangefs_dev_init();
+	if (ret < 0) {
+		gossip_err("%s: could not initialize device subsystem %d!\n",
+			   __func__,
+			   ret);
+		goto cleanup_sysfs;
+	}
+
+	ret = register_filesystem(&orangefs_fs_type);
+	if (ret == 0) {
+		pr_info("%s: module version %s loaded\n",
+			__func__,
+			ORANGEFS_VERSION);
+		goto out;
+	}
+
+	orangefs_dev_cleanup();
+
+cleanup_sysfs:
+	orangefs_sysfs_exit();
+
+sysfs_init_failed:
+	orangefs_debugfs_cleanup();
+
+cleanup_key_table:
+	fsid_key_table_finalize();
+
+cleanup_progress_table:
+	kfree(orangefs_htable_ops_in_progress);
+
+cleanup_inode:
+	orangefs_inode_cache_finalize();
+
+cleanup_op:
+	op_cache_finalize();
+
+out:
+	return ret;
+}
+
+static void __exit orangefs_exit(void)
+{
+	int i = 0;
+	gossip_debug(GOSSIP_INIT_DEBUG, "orangefs: orangefs_exit called\n");
+
+	unregister_filesystem(&orangefs_fs_type);
+	orangefs_debugfs_cleanup();
+	orangefs_sysfs_exit();
+	fsid_key_table_finalize();
+	orangefs_dev_cleanup();
+	BUG_ON(!list_empty(&orangefs_request_list));
+	for (i = 0; i < hash_table_size; i++)
+		BUG_ON(!list_empty(&orangefs_htable_ops_in_progress[i]));
+
+	orangefs_inode_cache_finalize();
+	op_cache_finalize();
+
+	kfree(orangefs_htable_ops_in_progress);
+
+	pr_info("orangefs: module version %s unloaded\n", ORANGEFS_VERSION);
+}
+
+/*
+ * What we do in this function is to walk the list of operations
+ * that are in progress in the hash table and mark them as purged as well.
+ */
+void purge_inprogress_ops(void)
+{
+	int i;
+
+	for (i = 0; i < hash_table_size; i++) {
+		struct orangefs_kernel_op_s *op;
+		struct orangefs_kernel_op_s *next;
+
+		spin_lock(&orangefs_htable_ops_in_progress_lock);
+		list_for_each_entry_safe(op,
+					 next,
+					 &orangefs_htable_ops_in_progress[i],
+					 list) {
+			set_op_state_purged(op);
+			gossip_debug(GOSSIP_DEV_DEBUG,
+				     "%s: op:%s: op_state:%d: process:%s:\n",
+				     __func__,
+				     get_opname_string(op),
+				     op->op_state,
+				     current->comm);
+		}
+		spin_unlock(&orangefs_htable_ops_in_progress_lock);
+	}
+}
+
+module_init(orangefs_init);
+module_exit(orangefs_exit);
diff --git a/fs/orangefs/orangefs-sysfs.c b/fs/orangefs/orangefs-sysfs.c
new file mode 100644
index 000000000..a02bfc7b3
--- /dev/null
+++ b/fs/orangefs/orangefs-sysfs.c
@@ -0,0 +1,1316 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Documentation/ABI/stable/sysfs-fs-orangefs:
+ *
+ * What:		/sys/fs/orangefs/perf_counter_reset
+ * Date:		June 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			echo a 0 or a 1 into perf_counter_reset to
+ * 			reset all the counters in
+ * 			/sys/fs/orangefs/perf_counters
+ * 			except ones with PINT_PERF_PRESERVE set.
+ *
+ *
+ * What:		/sys/fs/orangefs/perf_counters/...
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Counters and settings for various caches.
+ * 			Read only.
+ *
+ *
+ * What:		/sys/fs/orangefs/perf_time_interval_secs
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ *			Length of perf counter intervals in
+ *			seconds.
+ *
+ *
+ * What:		/sys/fs/orangefs/perf_history_size
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			The perf_counters cache statistics have N, or
+ * 			perf_history_size, samples. The default is
+ * 			one.
+ *
+ *			Every perf_time_interval_secs the (first)
+ *			samples are reset.
+ *
+ *			If N is greater than one, the "current" set
+ *			of samples is reset, and the samples from the
+ *			other N-1 intervals remain available.
+ *
+ *
+ * What:		/sys/fs/orangefs/op_timeout_secs
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ *			Service operation timeout in seconds.
+ *
+ *
+ * What:		/sys/fs/orangefs/slot_timeout_secs
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ *			"Slot" timeout in seconds. A "slot"
+ *			is an indexed buffer in the shared
+ *			memory segment used for communication
+ *			between the kernel module and userspace.
+ *			Slots are requested and waited for,
+ *			the wait times out after slot_timeout_secs.
+ *
+ * What:		/sys/fs/orangefs/cache_timeout_msecs
+ * Date:		Mar 2018
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Time in milliseconds between which
+ *			orangefs_revalidate_mapping will invalidate the page
+ *			cache.
+ *
+ * What:		/sys/fs/orangefs/dcache_timeout_msecs
+ * Date:		Jul 2016
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Time lookup is valid in milliseconds.
+ *
+ * What:		/sys/fs/orangefs/getattr_timeout_msecs
+ * Date:		Jul 2016
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Time getattr is valid in milliseconds.
+ *
+ * What:		/sys/fs/orangefs/readahead_count
+ * Date:		Aug 2016
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Readahead cache buffer count.
+ *
+ * What:		/sys/fs/orangefs/readahead_size
+ * Date:		Aug 2016
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Readahead cache buffer size.
+ *
+ * What:		/sys/fs/orangefs/readahead_count_size
+ * Date:		Aug 2016
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Readahead cache buffer count and size.
+ *
+ * What:		/sys/fs/orangefs/readahead_readcnt
+ * Date:		Jan 2017
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ *			Number of buffers (in multiples of readahead_size)
+ *			which can be read ahead for a single file at once.
+ *
+ * What:		/sys/fs/orangefs/acache/...
+ * Date:		Jun 2015
+ * Contact:		Martin Brandenburg <martin@omnibond.com>
+ * Description:
+ * 			Attribute cache configurable settings.
+ *
+ *
+ * What:		/sys/fs/orangefs/ncache/...
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Name cache configurable settings.
+ *
+ *
+ * What:		/sys/fs/orangefs/capcache/...
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Capability cache configurable settings.
+ *
+ *
+ * What:		/sys/fs/orangefs/ccache/...
+ * Date:		Jun 2015
+ * Contact:		Mike Marshall <hubcap@omnibond.com>
+ * Description:
+ * 			Credential cache configurable settings.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-sysfs.h"
+
+#define ORANGEFS_KOBJ_ID "orangefs"
+#define ACACHE_KOBJ_ID "acache"
+#define CAPCACHE_KOBJ_ID "capcache"
+#define CCACHE_KOBJ_ID "ccache"
+#define NCACHE_KOBJ_ID "ncache"
+#define PC_KOBJ_ID "pc"
+#define STATS_KOBJ_ID "stats"
+
+/*
+ * Every item calls orangefs_attr_show and orangefs_attr_store through
+ * orangefs_sysfs_ops. They look at the orangefs_attributes further below to
+ * call one of sysfs_int_show, sysfs_int_store, sysfs_service_op_show, or
+ * sysfs_service_op_store.
+ */
+
+struct orangefs_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct kobject *kobj,
+			struct orangefs_attribute *attr,
+			char *buf);
+	ssize_t (*store)(struct kobject *kobj,
+			 struct orangefs_attribute *attr,
+			 const char *buf,
+			 size_t count);
+};
+
+static ssize_t orangefs_attr_show(struct kobject *kobj,
+				  struct attribute *attr,
+				  char *buf)
+{
+	struct orangefs_attribute *attribute;
+
+	attribute = container_of(attr, struct orangefs_attribute, attr);
+	if (!attribute->show)
+		return -EIO;
+	return attribute->show(kobj, attribute, buf);
+}
+
+static ssize_t orangefs_attr_store(struct kobject *kobj,
+				   struct attribute *attr,
+				   const char *buf,
+				   size_t len)
+{
+	struct orangefs_attribute *attribute;
+
+	if (!strcmp(kobj->name, PC_KOBJ_ID) ||
+	    !strcmp(kobj->name, STATS_KOBJ_ID))
+		return -EPERM;
+
+	attribute = container_of(attr, struct orangefs_attribute, attr);
+	if (!attribute->store)
+		return -EIO;
+	return attribute->store(kobj, attribute, buf, len);
+}
+
+static const struct sysfs_ops orangefs_sysfs_ops = {
+	.show = orangefs_attr_show,
+	.store = orangefs_attr_store,
+};
+
+static ssize_t sysfs_int_show(struct kobject *kobj,
+    struct orangefs_attribute *attr, char *buf)
+{
+	int rc = -EIO;
+
+	gossip_debug(GOSSIP_SYSFS_DEBUG, "sysfs_int_show: id:%s:\n",
+	    kobj->name);
+
+	if (!strcmp(kobj->name, ORANGEFS_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "op_timeout_secs")) {
+			rc = sysfs_emit(buf,
+				       "%d\n",
+				       op_timeout_secs);
+			goto out;
+		} else if (!strcmp(attr->attr.name,
+				   "slot_timeout_secs")) {
+			rc = sysfs_emit(buf,
+				       "%d\n",
+				       slot_timeout_secs);
+			goto out;
+		} else if (!strcmp(attr->attr.name,
+				   "cache_timeout_msecs")) {
+			rc = sysfs_emit(buf,
+				       "%d\n",
+				       orangefs_cache_timeout_msecs);
+			goto out;
+		} else if (!strcmp(attr->attr.name,
+				   "dcache_timeout_msecs")) {
+			rc = sysfs_emit(buf,
+				       "%d\n",
+				       orangefs_dcache_timeout_msecs);
+			goto out;
+		} else if (!strcmp(attr->attr.name,
+				   "getattr_timeout_msecs")) {
+			rc = sysfs_emit(buf,
+				       "%d\n",
+				       orangefs_getattr_timeout_msecs);
+			goto out;
+		} else {
+			goto out;
+		}
+
+	} else if (!strcmp(kobj->name, STATS_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "reads")) {
+			rc = sysfs_emit(buf,
+				       "%lu\n",
+				       orangefs_stats.reads);
+			goto out;
+		} else if (!strcmp(attr->attr.name, "writes")) {
+			rc = sysfs_emit(buf,
+				       "%lu\n",
+				       orangefs_stats.writes);
+			goto out;
+		} else {
+			goto out;
+		}
+	}
+
+out:
+
+	return rc;
+}
+
+static ssize_t sysfs_int_store(struct kobject *kobj,
+    struct orangefs_attribute *attr, const char *buf, size_t count)
+{
+	int rc = 0;
+
+	gossip_debug(GOSSIP_SYSFS_DEBUG,
+		     "sysfs_int_store: start attr->attr.name:%s: buf:%s:\n",
+		     attr->attr.name, buf);
+
+	if (!strcmp(attr->attr.name, "op_timeout_secs")) {
+		rc = kstrtoint(buf, 0, &op_timeout_secs);
+		goto out;
+	} else if (!strcmp(attr->attr.name, "slot_timeout_secs")) {
+		rc = kstrtoint(buf, 0, &slot_timeout_secs);
+		goto out;
+	} else if (!strcmp(attr->attr.name, "cache_timeout_msecs")) {
+		rc = kstrtoint(buf, 0, &orangefs_cache_timeout_msecs);
+		goto out;
+	} else if (!strcmp(attr->attr.name, "dcache_timeout_msecs")) {
+		rc = kstrtoint(buf, 0, &orangefs_dcache_timeout_msecs);
+		goto out;
+	} else if (!strcmp(attr->attr.name, "getattr_timeout_msecs")) {
+		rc = kstrtoint(buf, 0, &orangefs_getattr_timeout_msecs);
+		goto out;
+	} else {
+		goto out;
+	}
+
+out:
+	if (rc)
+		rc = -EINVAL;
+	else
+		rc = count;
+
+	return rc;
+}
+
+/*
+ * obtain attribute values from userspace with a service operation.
+ */
+static ssize_t sysfs_service_op_show(struct kobject *kobj,
+    struct orangefs_attribute *attr, char *buf)
+{
+	struct orangefs_kernel_op_s *new_op = NULL;
+	int rc = 0;
+	char *ser_op_type = NULL;
+	__u32 op_alloc_type;
+
+	gossip_debug(GOSSIP_SYSFS_DEBUG,
+		     "sysfs_service_op_show: id:%s:\n",
+		     kobj->name);
+
+	if (strcmp(kobj->name, PC_KOBJ_ID))
+		op_alloc_type = ORANGEFS_VFS_OP_PARAM;
+	else
+		op_alloc_type = ORANGEFS_VFS_OP_PERF_COUNT;
+
+	new_op = op_alloc(op_alloc_type);
+	if (!new_op)
+		return -ENOMEM;
+
+	/* Can't do a service_operation if the client is not running... */
+	rc = is_daemon_in_service();
+	if (rc) {
+		pr_info_ratelimited("%s: Client not running :%d:\n",
+			__func__,
+			is_daemon_in_service());
+		goto out;
+	}
+
+	if (strcmp(kobj->name, PC_KOBJ_ID))
+		new_op->upcall.req.param.type = ORANGEFS_PARAM_REQUEST_GET;
+
+	if (!strcmp(kobj->name, ORANGEFS_KOBJ_ID)) {
+		/* Drop unsupported requests first. */
+		if (!(orangefs_features & ORANGEFS_FEATURE_READAHEAD) &&
+		    (!strcmp(attr->attr.name, "readahead_count") ||
+		    !strcmp(attr->attr.name, "readahead_size") ||
+		    !strcmp(attr->attr.name, "readahead_count_size") ||
+		    !strcmp(attr->attr.name, "readahead_readcnt"))) {
+			rc = -EINVAL;
+			goto out;
+		}
+
+		if (!strcmp(attr->attr.name, "perf_history_size"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_PERF_HISTORY_SIZE;
+		else if (!strcmp(attr->attr.name,
+				 "perf_time_interval_secs"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_PERF_TIME_INTERVAL_SECS;
+		else if (!strcmp(attr->attr.name,
+				 "perf_counter_reset"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_PERF_RESET;
+
+		else if (!strcmp(attr->attr.name,
+				 "readahead_count"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT;
+
+		else if (!strcmp(attr->attr.name,
+				 "readahead_size"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_SIZE;
+
+		else if (!strcmp(attr->attr.name,
+				 "readahead_count_size"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT_SIZE;
+
+		else if (!strcmp(attr->attr.name,
+				 "readahead_readcnt"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_READCNT;
+	} else if (!strcmp(kobj->name, ACACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "timeout_msecs"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_ACACHE_TIMEOUT_MSECS;
+
+		if (!strcmp(attr->attr.name, "hard_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_ACACHE_HARD_LIMIT;
+
+		if (!strcmp(attr->attr.name, "soft_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_ACACHE_SOFT_LIMIT;
+
+		if (!strcmp(attr->attr.name, "reclaim_percentage"))
+			new_op->upcall.req.param.op =
+			  ORANGEFS_PARAM_REQUEST_OP_ACACHE_RECLAIM_PERCENTAGE;
+
+	} else if (!strcmp(kobj->name, CAPCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "timeout_secs"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_TIMEOUT_SECS;
+
+		if (!strcmp(attr->attr.name, "hard_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_HARD_LIMIT;
+
+		if (!strcmp(attr->attr.name, "soft_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_SOFT_LIMIT;
+
+		if (!strcmp(attr->attr.name, "reclaim_percentage"))
+			new_op->upcall.req.param.op =
+			  ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_RECLAIM_PERCENTAGE;
+
+	} else if (!strcmp(kobj->name, CCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "timeout_secs"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CCACHE_TIMEOUT_SECS;
+
+		if (!strcmp(attr->attr.name, "hard_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CCACHE_HARD_LIMIT;
+
+		if (!strcmp(attr->attr.name, "soft_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_CCACHE_SOFT_LIMIT;
+
+		if (!strcmp(attr->attr.name, "reclaim_percentage"))
+			new_op->upcall.req.param.op =
+			  ORANGEFS_PARAM_REQUEST_OP_CCACHE_RECLAIM_PERCENTAGE;
+
+	} else if (!strcmp(kobj->name, NCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "timeout_msecs"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_NCACHE_TIMEOUT_MSECS;
+
+		if (!strcmp(attr->attr.name, "hard_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_NCACHE_HARD_LIMIT;
+
+		if (!strcmp(attr->attr.name, "soft_limit"))
+			new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_NCACHE_SOFT_LIMIT;
+
+		if (!strcmp(attr->attr.name, "reclaim_percentage"))
+			new_op->upcall.req.param.op =
+			  ORANGEFS_PARAM_REQUEST_OP_NCACHE_RECLAIM_PERCENTAGE;
+
+	} else if (!strcmp(kobj->name, PC_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, ACACHE_KOBJ_ID))
+			new_op->upcall.req.perf_count.type =
+				ORANGEFS_PERF_COUNT_REQUEST_ACACHE;
+
+		if (!strcmp(attr->attr.name, CAPCACHE_KOBJ_ID))
+			new_op->upcall.req.perf_count.type =
+				ORANGEFS_PERF_COUNT_REQUEST_CAPCACHE;
+
+		if (!strcmp(attr->attr.name, NCACHE_KOBJ_ID))
+			new_op->upcall.req.perf_count.type =
+				ORANGEFS_PERF_COUNT_REQUEST_NCACHE;
+
+	} else {
+		gossip_err("sysfs_service_op_show: unknown kobj_id:%s:\n",
+			   kobj->name);
+		rc = -EINVAL;
+		goto out;
+	}
+
+
+	if (strcmp(kobj->name, PC_KOBJ_ID))
+		ser_op_type = "orangefs_param";
+	else
+		ser_op_type = "orangefs_perf_count";
+
+	/*
+	 * The service_operation will return an errno return code on
+	 * error, and zero on success.
+	 */
+	rc = service_operation(new_op, ser_op_type, ORANGEFS_OP_INTERRUPTIBLE);
+
+out:
+	if (!rc) {
+		if (strcmp(kobj->name, PC_KOBJ_ID)) {
+			if (new_op->upcall.req.param.op ==
+			    ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT_SIZE) {
+				rc = sysfs_emit(buf, "%d %d\n",
+				    (int)new_op->downcall.resp.param.u.
+				    value32[0],
+				    (int)new_op->downcall.resp.param.u.
+				    value32[1]);
+			} else {
+				rc = sysfs_emit(buf, "%d\n",
+				    (int)new_op->downcall.resp.param.u.value64);
+			}
+		} else {
+			rc = sysfs_emit(
+				buf,
+				"%s",
+				new_op->downcall.resp.perf_count.buffer);
+		}
+	}
+
+	op_release(new_op);
+
+	return rc;
+
+}
+
+/*
+ * pass attribute values back to userspace with a service operation.
+ *
+ * We have to do a memory allocation, an sscanf and a service operation.
+ * And we have to evaluate what the user entered, to make sure the
+ * value is within the range supported by the attribute. So, there's
+ * a lot of return code checking and mapping going on here.
+ *
+ * We want to return 1 if we think everything went OK, and
+ * EINVAL if not.
+ */
+static ssize_t sysfs_service_op_store(struct kobject *kobj,
+    struct orangefs_attribute *attr, const char *buf, size_t count)
+{
+	struct orangefs_kernel_op_s *new_op = NULL;
+	int val = 0;
+	int rc = 0;
+
+	gossip_debug(GOSSIP_SYSFS_DEBUG,
+		     "sysfs_service_op_store: id:%s:\n",
+		     kobj->name);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_PARAM);
+	if (!new_op)
+		return -EINVAL; /* sic */
+
+	/* Can't do a service_operation if the client is not running... */
+	rc = is_daemon_in_service();
+	if (rc) {
+		pr_info("%s: Client not running :%d:\n",
+			__func__,
+			is_daemon_in_service());
+		goto out;
+	}
+
+	/*
+	 * The value we want to send back to userspace is in buf, unless this
+	 * there are two parameters, which is specially handled below.
+	 */
+	if (strcmp(kobj->name, ORANGEFS_KOBJ_ID) ||
+	    strcmp(attr->attr.name, "readahead_count_size")) {
+		rc = kstrtoint(buf, 0, &val);
+		if (rc)
+			goto out;
+	}
+
+	new_op->upcall.req.param.type = ORANGEFS_PARAM_REQUEST_SET;
+
+	if (!strcmp(kobj->name, ORANGEFS_KOBJ_ID)) {
+		/* Drop unsupported requests first. */
+		if (!(orangefs_features & ORANGEFS_FEATURE_READAHEAD) &&
+		    (!strcmp(attr->attr.name, "readahead_count") ||
+		    !strcmp(attr->attr.name, "readahead_size") ||
+		    !strcmp(attr->attr.name, "readahead_count_size") ||
+		    !strcmp(attr->attr.name, "readahead_readcnt"))) {
+			rc = -EINVAL;
+			goto out;
+		}
+
+		if (!strcmp(attr->attr.name, "perf_history_size")) {
+			if (val > 0) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_PERF_HISTORY_SIZE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "perf_time_interval_secs")) {
+			if (val > 0) {
+				new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_PERF_TIME_INTERVAL_SECS;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "perf_counter_reset")) {
+			if ((val == 0) || (val == 1)) {
+				new_op->upcall.req.param.op =
+					ORANGEFS_PARAM_REQUEST_OP_PERF_RESET;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "readahead_count")) {
+			if ((val >= 0)) {
+				new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "readahead_size")) {
+			if ((val >= 0)) {
+				new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_SIZE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "readahead_count_size")) {
+			int val1, val2;
+			rc = sscanf(buf, "%d %d", &val1, &val2);
+			if (rc < 2) {
+				rc = 0;
+				goto out;
+			}
+			if ((val1 >= 0) && (val2 >= 0)) {
+				new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT_SIZE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+			new_op->upcall.req.param.u.value32[0] = val1;
+			new_op->upcall.req.param.u.value32[1] = val2;
+			goto value_set;
+		} else if (!strcmp(attr->attr.name,
+				   "readahead_readcnt")) {
+			if ((val >= 0)) {
+				new_op->upcall.req.param.op =
+				ORANGEFS_PARAM_REQUEST_OP_READAHEAD_READCNT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		}
+
+	} else if (!strcmp(kobj->name, ACACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "hard_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_ACACHE_HARD_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "soft_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_ACACHE_SOFT_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "reclaim_percentage")) {
+			if ((val > -1) && (val < 101)) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_ACACHE_RECLAIM_PERCENTAGE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "timeout_msecs")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_ACACHE_TIMEOUT_MSECS;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		}
+
+	} else if (!strcmp(kobj->name, CAPCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "hard_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_HARD_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "soft_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_SOFT_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "reclaim_percentage")) {
+			if ((val > -1) && (val < 101)) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_RECLAIM_PERCENTAGE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "timeout_secs")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_TIMEOUT_SECS;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		}
+
+	} else if (!strcmp(kobj->name, CCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "hard_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CCACHE_HARD_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "soft_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CCACHE_SOFT_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "reclaim_percentage")) {
+			if ((val > -1) && (val < 101)) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CCACHE_RECLAIM_PERCENTAGE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "timeout_secs")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_CCACHE_TIMEOUT_SECS;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		}
+
+	} else if (!strcmp(kobj->name, NCACHE_KOBJ_ID)) {
+		if (!strcmp(attr->attr.name, "hard_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_NCACHE_HARD_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "soft_limit")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_NCACHE_SOFT_LIMIT;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name,
+				   "reclaim_percentage")) {
+			if ((val > -1) && (val < 101)) {
+				new_op->upcall.req.param.op =
+					ORANGEFS_PARAM_REQUEST_OP_NCACHE_RECLAIM_PERCENTAGE;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		} else if (!strcmp(attr->attr.name, "timeout_msecs")) {
+			if (val > -1) {
+				new_op->upcall.req.param.op =
+				  ORANGEFS_PARAM_REQUEST_OP_NCACHE_TIMEOUT_MSECS;
+			} else {
+				rc = 0;
+				goto out;
+			}
+		}
+
+	} else {
+		gossip_err("sysfs_service_op_store: unknown kobj_id:%s:\n",
+			   kobj->name);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	new_op->upcall.req.param.u.value64 = val;
+value_set:
+
+	/*
+	 * The service_operation will return a errno return code on
+	 * error, and zero on success.
+	 */
+	rc = service_operation(new_op, "orangefs_param", ORANGEFS_OP_INTERRUPTIBLE);
+
+	if (rc < 0) {
+		gossip_err("sysfs_service_op_store: service op returned:%d:\n",
+			rc);
+		rc = 0;
+	} else {
+		rc = count;
+	}
+
+out:
+	op_release(new_op);
+
+	if (rc == -ENOMEM || rc == 0)
+		rc = -EINVAL;
+
+	return rc;
+}
+
+static struct orangefs_attribute op_timeout_secs_attribute =
+	__ATTR(op_timeout_secs, 0664, sysfs_int_show, sysfs_int_store);
+
+static struct orangefs_attribute slot_timeout_secs_attribute =
+	__ATTR(slot_timeout_secs, 0664, sysfs_int_show, sysfs_int_store);
+
+static struct orangefs_attribute cache_timeout_msecs_attribute =
+	__ATTR(cache_timeout_msecs, 0664, sysfs_int_show, sysfs_int_store);
+
+static struct orangefs_attribute dcache_timeout_msecs_attribute =
+	__ATTR(dcache_timeout_msecs, 0664, sysfs_int_show, sysfs_int_store);
+
+static struct orangefs_attribute getattr_timeout_msecs_attribute =
+	__ATTR(getattr_timeout_msecs, 0664, sysfs_int_show, sysfs_int_store);
+
+static struct orangefs_attribute readahead_count_attribute =
+	__ATTR(readahead_count, 0664, sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute readahead_size_attribute =
+	__ATTR(readahead_size, 0664, sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute readahead_count_size_attribute =
+	__ATTR(readahead_count_size, 0664, sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute readahead_readcnt_attribute =
+	__ATTR(readahead_readcnt, 0664, sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute perf_counter_reset_attribute =
+	__ATTR(perf_counter_reset,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute perf_history_size_attribute =
+	__ATTR(perf_history_size,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute perf_time_interval_secs_attribute =
+	__ATTR(perf_time_interval_secs,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct attribute *orangefs_default_attrs[] = {
+	&op_timeout_secs_attribute.attr,
+	&slot_timeout_secs_attribute.attr,
+	&cache_timeout_msecs_attribute.attr,
+	&dcache_timeout_msecs_attribute.attr,
+	&getattr_timeout_msecs_attribute.attr,
+	&readahead_count_attribute.attr,
+	&readahead_size_attribute.attr,
+	&readahead_count_size_attribute.attr,
+	&readahead_readcnt_attribute.attr,
+	&perf_counter_reset_attribute.attr,
+	&perf_history_size_attribute.attr,
+	&perf_time_interval_secs_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(orangefs_default);
+
+static struct kobject *orangefs_obj;
+
+static void orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(orangefs_obj);
+	orangefs_obj = NULL;
+}
+
+static const struct kobj_type orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = orangefs_default_groups,
+	.release = orangefs_obj_release,
+};
+
+static struct orangefs_attribute acache_hard_limit_attribute =
+	__ATTR(hard_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute acache_reclaim_percent_attribute =
+	__ATTR(reclaim_percentage,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute acache_soft_limit_attribute =
+	__ATTR(soft_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute acache_timeout_msecs_attribute =
+	__ATTR(timeout_msecs,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct attribute *acache_orangefs_default_attrs[] = {
+	&acache_hard_limit_attribute.attr,
+	&acache_reclaim_percent_attribute.attr,
+	&acache_soft_limit_attribute.attr,
+	&acache_timeout_msecs_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(acache_orangefs_default);
+
+static struct kobject *acache_orangefs_obj;
+
+static void acache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(acache_orangefs_obj);
+	acache_orangefs_obj = NULL;
+}
+
+static const struct kobj_type acache_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = acache_orangefs_default_groups,
+	.release = acache_orangefs_obj_release,
+};
+
+static struct orangefs_attribute capcache_hard_limit_attribute =
+	__ATTR(hard_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute capcache_reclaim_percent_attribute =
+	__ATTR(reclaim_percentage,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute capcache_soft_limit_attribute =
+	__ATTR(soft_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute capcache_timeout_secs_attribute =
+	__ATTR(timeout_secs,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct attribute *capcache_orangefs_default_attrs[] = {
+	&capcache_hard_limit_attribute.attr,
+	&capcache_reclaim_percent_attribute.attr,
+	&capcache_soft_limit_attribute.attr,
+	&capcache_timeout_secs_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(capcache_orangefs_default);
+
+static struct kobject *capcache_orangefs_obj;
+
+static void capcache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(capcache_orangefs_obj);
+	capcache_orangefs_obj = NULL;
+}
+
+static const struct kobj_type capcache_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = capcache_orangefs_default_groups,
+	.release = capcache_orangefs_obj_release,
+};
+
+static struct orangefs_attribute ccache_hard_limit_attribute =
+	__ATTR(hard_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ccache_reclaim_percent_attribute =
+	__ATTR(reclaim_percentage,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ccache_soft_limit_attribute =
+	__ATTR(soft_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ccache_timeout_secs_attribute =
+	__ATTR(timeout_secs,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct attribute *ccache_orangefs_default_attrs[] = {
+	&ccache_hard_limit_attribute.attr,
+	&ccache_reclaim_percent_attribute.attr,
+	&ccache_soft_limit_attribute.attr,
+	&ccache_timeout_secs_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ccache_orangefs_default);
+
+static struct kobject *ccache_orangefs_obj;
+
+static void ccache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(ccache_orangefs_obj);
+	ccache_orangefs_obj = NULL;
+}
+
+static const struct kobj_type ccache_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = ccache_orangefs_default_groups,
+	.release = ccache_orangefs_obj_release,
+};
+
+static struct orangefs_attribute ncache_hard_limit_attribute =
+	__ATTR(hard_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ncache_reclaim_percent_attribute =
+	__ATTR(reclaim_percentage,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ncache_soft_limit_attribute =
+	__ATTR(soft_limit,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct orangefs_attribute ncache_timeout_msecs_attribute =
+	__ATTR(timeout_msecs,
+	       0664,
+	       sysfs_service_op_show,
+	       sysfs_service_op_store);
+
+static struct attribute *ncache_orangefs_default_attrs[] = {
+	&ncache_hard_limit_attribute.attr,
+	&ncache_reclaim_percent_attribute.attr,
+	&ncache_soft_limit_attribute.attr,
+	&ncache_timeout_msecs_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ncache_orangefs_default);
+
+static struct kobject *ncache_orangefs_obj;
+
+static void ncache_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(ncache_orangefs_obj);
+	ncache_orangefs_obj = NULL;
+}
+
+static const struct kobj_type ncache_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = ncache_orangefs_default_groups,
+	.release = ncache_orangefs_obj_release,
+};
+
+static struct orangefs_attribute pc_acache_attribute =
+	__ATTR(acache,
+	       0664,
+	       sysfs_service_op_show,
+	       NULL);
+
+static struct orangefs_attribute pc_capcache_attribute =
+	__ATTR(capcache,
+	       0664,
+	       sysfs_service_op_show,
+	       NULL);
+
+static struct orangefs_attribute pc_ncache_attribute =
+	__ATTR(ncache,
+	       0664,
+	       sysfs_service_op_show,
+	       NULL);
+
+static struct attribute *pc_orangefs_default_attrs[] = {
+	&pc_acache_attribute.attr,
+	&pc_capcache_attribute.attr,
+	&pc_ncache_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pc_orangefs_default);
+
+static struct kobject *pc_orangefs_obj;
+
+static void pc_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(pc_orangefs_obj);
+	pc_orangefs_obj = NULL;
+}
+
+static const struct kobj_type pc_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = pc_orangefs_default_groups,
+	.release = pc_orangefs_obj_release,
+};
+
+static struct orangefs_attribute stats_reads_attribute =
+	__ATTR(reads,
+	       0664,
+	       sysfs_int_show,
+	       NULL);
+
+static struct orangefs_attribute stats_writes_attribute =
+	__ATTR(writes,
+	       0664,
+	       sysfs_int_show,
+	       NULL);
+
+static struct attribute *stats_orangefs_default_attrs[] = {
+	&stats_reads_attribute.attr,
+	&stats_writes_attribute.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(stats_orangefs_default);
+
+static struct kobject *stats_orangefs_obj;
+
+static void stats_orangefs_obj_release(struct kobject *kobj)
+{
+	kfree(stats_orangefs_obj);
+	stats_orangefs_obj = NULL;
+}
+
+static const struct kobj_type stats_orangefs_ktype = {
+	.sysfs_ops = &orangefs_sysfs_ops,
+	.default_groups = stats_orangefs_default_groups,
+	.release = stats_orangefs_obj_release,
+};
+
+int orangefs_sysfs_init(void)
+{
+	int rc = -EINVAL;
+
+	gossip_debug(GOSSIP_SYSFS_DEBUG, "orangefs_sysfs_init: start\n");
+
+	/* create /sys/fs/orangefs. */
+	orangefs_obj = kzalloc_obj(*orangefs_obj);
+	if (!orangefs_obj)
+		goto out;
+
+	rc = kobject_init_and_add(orangefs_obj,
+				  &orangefs_ktype,
+				  fs_kobj,
+				  ORANGEFS_KOBJ_ID);
+
+	if (rc)
+		goto ofs_obj_bail;
+
+	kobject_uevent(orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/acache. */
+	acache_orangefs_obj = kzalloc_obj(*acache_orangefs_obj);
+	if (!acache_orangefs_obj) {
+		rc = -EINVAL;
+		goto ofs_obj_bail;
+	}
+
+	rc = kobject_init_and_add(acache_orangefs_obj,
+				  &acache_orangefs_ktype,
+				  orangefs_obj,
+				  ACACHE_KOBJ_ID);
+
+	if (rc)
+		goto acache_obj_bail;
+
+	kobject_uevent(acache_orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/capcache. */
+	capcache_orangefs_obj = kzalloc_obj(*capcache_orangefs_obj);
+	if (!capcache_orangefs_obj) {
+		rc = -EINVAL;
+		goto acache_obj_bail;
+	}
+
+	rc = kobject_init_and_add(capcache_orangefs_obj,
+				  &capcache_orangefs_ktype,
+				  orangefs_obj,
+				  CAPCACHE_KOBJ_ID);
+	if (rc)
+		goto capcache_obj_bail;
+
+	kobject_uevent(capcache_orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/ccache. */
+	ccache_orangefs_obj = kzalloc_obj(*ccache_orangefs_obj);
+	if (!ccache_orangefs_obj) {
+		rc = -EINVAL;
+		goto capcache_obj_bail;
+	}
+
+	rc = kobject_init_and_add(ccache_orangefs_obj,
+				  &ccache_orangefs_ktype,
+				  orangefs_obj,
+				  CCACHE_KOBJ_ID);
+	if (rc)
+		goto ccache_obj_bail;
+
+	kobject_uevent(ccache_orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/ncache. */
+	ncache_orangefs_obj = kzalloc_obj(*ncache_orangefs_obj);
+	if (!ncache_orangefs_obj) {
+		rc = -EINVAL;
+		goto ccache_obj_bail;
+	}
+
+	rc = kobject_init_and_add(ncache_orangefs_obj,
+				  &ncache_orangefs_ktype,
+				  orangefs_obj,
+				  NCACHE_KOBJ_ID);
+
+	if (rc)
+		goto ncache_obj_bail;
+
+	kobject_uevent(ncache_orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/perf_counters. */
+	pc_orangefs_obj = kzalloc_obj(*pc_orangefs_obj);
+	if (!pc_orangefs_obj) {
+		rc = -EINVAL;
+		goto ncache_obj_bail;
+	}
+
+	rc = kobject_init_and_add(pc_orangefs_obj,
+				  &pc_orangefs_ktype,
+				  orangefs_obj,
+				  "perf_counters");
+
+	if (rc)
+		goto pc_obj_bail;
+
+	kobject_uevent(pc_orangefs_obj, KOBJ_ADD);
+
+	/* create /sys/fs/orangefs/stats. */
+	stats_orangefs_obj = kzalloc_obj(*stats_orangefs_obj);
+	if (!stats_orangefs_obj) {
+		rc = -EINVAL;
+		goto pc_obj_bail;
+	}
+
+	rc = kobject_init_and_add(stats_orangefs_obj,
+				  &stats_orangefs_ktype,
+				  orangefs_obj,
+				  STATS_KOBJ_ID);
+
+	if (rc)
+		goto stats_obj_bail;
+
+	kobject_uevent(stats_orangefs_obj, KOBJ_ADD);
+	goto out;
+
+stats_obj_bail:
+		kobject_put(stats_orangefs_obj);
+pc_obj_bail:
+		kobject_put(pc_orangefs_obj);
+ncache_obj_bail:
+		kobject_put(ncache_orangefs_obj);
+ccache_obj_bail:
+		kobject_put(ccache_orangefs_obj);
+capcache_obj_bail:
+		kobject_put(capcache_orangefs_obj);
+acache_obj_bail:
+		kobject_put(acache_orangefs_obj);
+ofs_obj_bail:
+		kobject_put(orangefs_obj);
+out:
+	return rc;
+}
+
+void orangefs_sysfs_exit(void)
+{
+	gossip_debug(GOSSIP_SYSFS_DEBUG, "orangefs_sysfs_exit: start\n");
+	kobject_put(acache_orangefs_obj);
+	kobject_put(capcache_orangefs_obj);
+	kobject_put(ccache_orangefs_obj);
+	kobject_put(ncache_orangefs_obj);
+	kobject_put(pc_orangefs_obj);
+	kobject_put(stats_orangefs_obj);
+	kobject_put(orangefs_obj);
+}
diff --git a/fs/orangefs/orangefs-sysfs.h b/fs/orangefs/orangefs-sysfs.h
new file mode 100644
index 000000000..f0b76382d
--- /dev/null
+++ b/fs/orangefs/orangefs-sysfs.h
@@ -0,0 +1,2 @@
+extern int orangefs_sysfs_init(void);
+extern void orangefs_sysfs_exit(void);
diff --git a/fs/orangefs/orangefs-utils.c b/fs/orangefs/orangefs-utils.c
new file mode 100644
index 000000000..9ab1119eb
--- /dev/null
+++ b/fs/orangefs/orangefs-utils.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * Copyright 2018 Omnibond Systems, L.L.C.
+ *
+ * See COPYING in top-level directory.
+ */
+#include <linux/kernel.h>
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-dev-proto.h"
+#include "orangefs-bufmap.h"
+
+__s32 fsid_of_op(struct orangefs_kernel_op_s *op)
+{
+	__s32 fsid = ORANGEFS_FS_ID_NULL;
+
+	if (op) {
+		switch (op->upcall.type) {
+		case ORANGEFS_VFS_OP_FILE_IO:
+			fsid = op->upcall.req.io.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_LOOKUP:
+			fsid = op->upcall.req.lookup.parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_CREATE:
+			fsid = op->upcall.req.create.parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_GETATTR:
+			fsid = op->upcall.req.getattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_REMOVE:
+			fsid = op->upcall.req.remove.parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_MKDIR:
+			fsid = op->upcall.req.mkdir.parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_READDIR:
+			fsid = op->upcall.req.readdir.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_SETATTR:
+			fsid = op->upcall.req.setattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_SYMLINK:
+			fsid = op->upcall.req.sym.parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_RENAME:
+			fsid = op->upcall.req.rename.old_parent_refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_STATFS:
+			fsid = op->upcall.req.statfs.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_TRUNCATE:
+			fsid = op->upcall.req.truncate.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_RA_FLUSH:
+			fsid = op->upcall.req.ra_cache_flush.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_FS_UMOUNT:
+			fsid = op->upcall.req.fs_umount.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_GETXATTR:
+			fsid = op->upcall.req.getxattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_SETXATTR:
+			fsid = op->upcall.req.setxattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_LISTXATTR:
+			fsid = op->upcall.req.listxattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_REMOVEXATTR:
+			fsid = op->upcall.req.removexattr.refn.fs_id;
+			break;
+		case ORANGEFS_VFS_OP_FSYNC:
+			fsid = op->upcall.req.fsync.refn.fs_id;
+			break;
+		default:
+			break;
+		}
+	}
+	return fsid;
+}
+
+static int orangefs_inode_flags(struct ORANGEFS_sys_attr_s *attrs)
+{
+	int flags = 0;
+	if (attrs->flags & ORANGEFS_IMMUTABLE_FL)
+		flags |= S_IMMUTABLE;
+	else
+		flags &= ~S_IMMUTABLE;
+	if (attrs->flags & ORANGEFS_APPEND_FL)
+		flags |= S_APPEND;
+	else
+		flags &= ~S_APPEND;
+	if (attrs->flags & ORANGEFS_NOATIME_FL)
+		flags |= S_NOATIME;
+	else
+		flags &= ~S_NOATIME;
+	return flags;
+}
+
+static int orangefs_inode_perms(struct ORANGEFS_sys_attr_s *attrs)
+{
+	int perm_mode = 0;
+
+	if (attrs->perms & ORANGEFS_O_EXECUTE)
+		perm_mode |= S_IXOTH;
+	if (attrs->perms & ORANGEFS_O_WRITE)
+		perm_mode |= S_IWOTH;
+	if (attrs->perms & ORANGEFS_O_READ)
+		perm_mode |= S_IROTH;
+
+	if (attrs->perms & ORANGEFS_G_EXECUTE)
+		perm_mode |= S_IXGRP;
+	if (attrs->perms & ORANGEFS_G_WRITE)
+		perm_mode |= S_IWGRP;
+	if (attrs->perms & ORANGEFS_G_READ)
+		perm_mode |= S_IRGRP;
+
+	if (attrs->perms & ORANGEFS_U_EXECUTE)
+		perm_mode |= S_IXUSR;
+	if (attrs->perms & ORANGEFS_U_WRITE)
+		perm_mode |= S_IWUSR;
+	if (attrs->perms & ORANGEFS_U_READ)
+		perm_mode |= S_IRUSR;
+
+	if (attrs->perms & ORANGEFS_G_SGID)
+		perm_mode |= S_ISGID;
+	if (attrs->perms & ORANGEFS_U_SUID)
+		perm_mode |= S_ISUID;
+
+	return perm_mode;
+}
+
+/*
+ * NOTE: in kernel land, we never use the sys_attr->link_target for
+ * anything, so don't bother copying it into the sys_attr object here.
+ */
+static inline void copy_attributes_from_inode(struct inode *inode,
+    struct ORANGEFS_sys_attr_s *attrs)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	attrs->mask = 0;
+	if (orangefs_inode->attr_valid & ATTR_UID) {
+		attrs->owner = from_kuid(&init_user_ns, inode->i_uid);
+		attrs->mask |= ORANGEFS_ATTR_SYS_UID;
+		gossip_debug(GOSSIP_UTILS_DEBUG, "(UID) %d\n", attrs->owner);
+	}
+	if (orangefs_inode->attr_valid & ATTR_GID) {
+		attrs->group = from_kgid(&init_user_ns, inode->i_gid);
+		attrs->mask |= ORANGEFS_ATTR_SYS_GID;
+		gossip_debug(GOSSIP_UTILS_DEBUG, "(GID) %d\n", attrs->group);
+	}
+
+	if (orangefs_inode->attr_valid & ATTR_ATIME) {
+		attrs->mask |= ORANGEFS_ATTR_SYS_ATIME;
+		if (orangefs_inode->attr_valid & ATTR_ATIME_SET) {
+			attrs->atime = (time64_t) inode_get_atime_sec(inode);
+			attrs->mask |= ORANGEFS_ATTR_SYS_ATIME_SET;
+		}
+	}
+	if (orangefs_inode->attr_valid & ATTR_MTIME) {
+		attrs->mask |= ORANGEFS_ATTR_SYS_MTIME;
+		if (orangefs_inode->attr_valid & ATTR_MTIME_SET) {
+			attrs->mtime = (time64_t) inode_get_mtime_sec(inode);
+			attrs->mask |= ORANGEFS_ATTR_SYS_MTIME_SET;
+		}
+	}
+	if (orangefs_inode->attr_valid & ATTR_CTIME)
+		attrs->mask |= ORANGEFS_ATTR_SYS_CTIME;
+
+	/*
+	 * ORANGEFS cannot set size with a setattr operation. Probably not
+	 * likely to be requested through the VFS, but just in case, don't
+	 * worry about ATTR_SIZE
+	 */
+
+	if (orangefs_inode->attr_valid & ATTR_MODE) {
+		attrs->perms = ORANGEFS_util_translate_mode(inode->i_mode);
+		attrs->mask |= ORANGEFS_ATTR_SYS_PERM;
+	}
+}
+
+static int orangefs_inode_type(enum orangefs_ds_type objtype)
+{
+	if (objtype == ORANGEFS_TYPE_METAFILE)
+		return S_IFREG;
+	else if (objtype == ORANGEFS_TYPE_DIRECTORY)
+		return S_IFDIR;
+	else if (objtype == ORANGEFS_TYPE_SYMLINK)
+		return S_IFLNK;
+	else
+		return -1;
+}
+
+static void orangefs_make_bad_inode(struct inode *inode)
+{
+	if (is_root_handle(inode)) {
+		/*
+		 * if this occurs, the pvfs2-client-core was killed but we
+		 * can't afford to lose the inode operations and such
+		 * associated with the root handle in any case.
+		 */
+		gossip_debug(GOSSIP_UTILS_DEBUG,
+			     "*** NOT making bad root inode %pU\n",
+			     get_khandle_from_ino(inode));
+	} else {
+		gossip_debug(GOSSIP_UTILS_DEBUG,
+			     "*** making bad inode %pU\n",
+			     get_khandle_from_ino(inode));
+		make_bad_inode(inode);
+	}
+}
+
+static int orangefs_inode_is_stale(struct inode *inode,
+    struct ORANGEFS_sys_attr_s *attrs, char *link_target)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	int type = orangefs_inode_type(attrs->objtype);
+	/*
+	 * If the inode type or symlink target have changed then this
+	 * inode is stale.
+	 */
+	if (type == -1 || inode_wrong_type(inode, type)) {
+		orangefs_make_bad_inode(inode);
+		return 1;
+	}
+	if (type == S_IFLNK && strncmp(orangefs_inode->link_target,
+	    link_target, ORANGEFS_NAME_MAX)) {
+		orangefs_make_bad_inode(inode);
+		return 1;
+	}
+	return 0;
+}
+
+int orangefs_inode_getattr(struct inode *inode, int flags)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	loff_t inode_size;
+	int ret, type;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: called on inode %pU flags %d\n",
+	    __func__, get_khandle_from_ino(inode), flags);
+
+again:
+	spin_lock(&inode->i_lock);
+	/* Must have all the attributes in the mask and be within cache time. */
+	if ((!flags && time_before(jiffies, orangefs_inode->getattr_time)) ||
+	    orangefs_inode->attr_valid || inode_state_read(inode) & I_DIRTY_PAGES) {
+		if (orangefs_inode->attr_valid) {
+			spin_unlock(&inode->i_lock);
+			write_inode_now(inode, 1);
+			goto again;
+		}
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+	spin_unlock(&inode->i_lock);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_GETATTR);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.getattr.refn = orangefs_inode->refn;
+	/*
+	 * Size is the hardest attribute to get.  The incremental cost of any
+	 * other attribute is essentially zero.
+	 */
+	if (flags)
+		new_op->upcall.req.getattr.mask = ORANGEFS_ATTR_SYS_ALL_NOHINT;
+	else
+		new_op->upcall.req.getattr.mask =
+		    ORANGEFS_ATTR_SYS_ALL_NOHINT & ~ORANGEFS_ATTR_SYS_SIZE;
+
+	ret = service_operation(new_op, __func__,
+	    get_interruptible_flag(inode));
+	if (ret != 0)
+		goto out;
+
+again2:
+	spin_lock(&inode->i_lock);
+	/* Must have all the attributes in the mask and be within cache time. */
+	if ((!flags && time_before(jiffies, orangefs_inode->getattr_time)) ||
+	    orangefs_inode->attr_valid || inode_state_read(inode) & I_DIRTY_PAGES) {
+		if (orangefs_inode->attr_valid) {
+			spin_unlock(&inode->i_lock);
+			write_inode_now(inode, 1);
+			goto again2;
+		}
+		if (inode_state_read(inode) & I_DIRTY_PAGES) {
+			ret = 0;
+			goto out_unlock;
+		}
+		gossip_debug(GOSSIP_UTILS_DEBUG, "%s: in cache or dirty\n",
+		    __func__);
+		ret = 0;
+		goto out_unlock;
+	}
+
+	if (!(flags & ORANGEFS_GETATTR_NEW)) {
+		ret = orangefs_inode_is_stale(inode,
+		    &new_op->downcall.resp.getattr.attributes,
+		    new_op->downcall.resp.getattr.link_target);
+		if (ret) {
+			ret = -ESTALE;
+			goto out_unlock;
+		}
+	}
+
+	type = orangefs_inode_type(new_op->
+	    downcall.resp.getattr.attributes.objtype);
+	switch (type) {
+	case S_IFREG:
+		inode->i_flags = orangefs_inode_flags(&new_op->
+		    downcall.resp.getattr.attributes);
+		if (flags) {
+			inode_size = (loff_t)new_op->
+			    downcall.resp.getattr.attributes.size;
+			inode->i_size = inode_size;
+			inode->i_blkbits = ffs(new_op->downcall.resp.getattr.
+			    attributes.blksize);
+			inode->i_bytes = inode_size;
+			inode->i_blocks =
+			    (inode_size + 512 - inode_size % 512)/512;
+		}
+		break;
+	case S_IFDIR:
+		if (flags) {
+			inode->i_size = PAGE_SIZE;
+			inode_set_bytes(inode, inode->i_size);
+		}
+		set_nlink(inode, 1);
+		break;
+	case S_IFLNK:
+		if (flags & ORANGEFS_GETATTR_NEW) {
+			inode->i_size = (loff_t)strlen(new_op->
+			    downcall.resp.getattr.link_target);
+			ret = strscpy(orangefs_inode->link_target,
+			    new_op->downcall.resp.getattr.link_target,
+			    ORANGEFS_NAME_MAX);
+			if (ret == -E2BIG) {
+				ret = -EIO;
+				goto out_unlock;
+			}
+			inode->i_link = orangefs_inode->link_target;
+		}
+		break;
+	/* i.e. -1 */
+	default:
+		/* XXX: ESTALE?  This is what is done if it is not new. */
+		orangefs_make_bad_inode(inode);
+		ret = -ESTALE;
+		goto out_unlock;
+	}
+
+	inode->i_uid = make_kuid(&init_user_ns, new_op->
+	    downcall.resp.getattr.attributes.owner);
+	inode->i_gid = make_kgid(&init_user_ns, new_op->
+	    downcall.resp.getattr.attributes.group);
+	inode_set_atime(inode,
+			(time64_t)new_op->downcall.resp.getattr.attributes.atime,
+			0);
+	inode_set_mtime(inode,
+			(time64_t)new_op->downcall.resp.getattr.attributes.mtime,
+			0);
+	inode_set_ctime(inode,
+			(time64_t)new_op->downcall.resp.getattr.attributes.ctime,
+			0);
+
+	/* special case: mark the root inode as sticky */
+	inode->i_mode = type | (is_root_handle(inode) ? S_ISVTX : 0) |
+	    orangefs_inode_perms(&new_op->downcall.resp.getattr.attributes);
+
+	orangefs_inode->getattr_time = jiffies +
+	    orangefs_getattr_timeout_msecs*HZ/1000;
+	ret = 0;
+out_unlock:
+	spin_unlock(&inode->i_lock);
+out:
+	op_release(new_op);
+	return ret;
+}
+
+int orangefs_inode_check_changed(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int ret;
+
+	gossip_debug(GOSSIP_UTILS_DEBUG, "%s: called on inode %pU\n", __func__,
+	    get_khandle_from_ino(inode));
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_GETATTR);
+	if (!new_op)
+		return -ENOMEM;
+	new_op->upcall.req.getattr.refn = orangefs_inode->refn;
+	new_op->upcall.req.getattr.mask = ORANGEFS_ATTR_SYS_TYPE |
+	    ORANGEFS_ATTR_SYS_LNK_TARGET;
+
+	ret = service_operation(new_op, __func__,
+	    get_interruptible_flag(inode));
+	if (ret != 0)
+		goto out;
+
+	ret = orangefs_inode_is_stale(inode,
+	    &new_op->downcall.resp.getattr.attributes,
+	    new_op->downcall.resp.getattr.link_target);
+out:
+	op_release(new_op);
+	return ret;
+}
+
+/*
+ * issues a orangefs setattr request to make sure the new attribute values
+ * take effect if successful.  returns 0 on success; -errno otherwise
+ */
+int orangefs_inode_setattr(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int ret;
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_SETATTR);
+	if (!new_op)
+		return -ENOMEM;
+
+	spin_lock(&inode->i_lock);
+	new_op->upcall.uid = from_kuid(&init_user_ns, orangefs_inode->attr_uid);
+	new_op->upcall.gid = from_kgid(&init_user_ns, orangefs_inode->attr_gid);
+	new_op->upcall.req.setattr.refn = orangefs_inode->refn;
+	copy_attributes_from_inode(inode,
+	    &new_op->upcall.req.setattr.attributes);
+	orangefs_inode->attr_valid = 0;
+	if (!new_op->upcall.req.setattr.attributes.mask) {
+		spin_unlock(&inode->i_lock);
+		op_release(new_op);
+		return 0;
+	}
+	spin_unlock(&inode->i_lock);
+
+	ret = service_operation(new_op, __func__,
+	    get_interruptible_flag(inode) | ORANGEFS_OP_WRITEBACK);
+	gossip_debug(GOSSIP_UTILS_DEBUG,
+	    "orangefs_inode_setattr: returning %d\n", ret);
+	if (ret)
+		orangefs_make_bad_inode(inode);
+
+	op_release(new_op);
+
+	if (ret == 0)
+		orangefs_inode->getattr_time = jiffies - 1;
+	return ret;
+}
+
+/*
+ * The following is a very dirty hack that is now a permanent part of the
+ * ORANGEFS protocol. See protocol.h for more error definitions.
+ */
+
+/* The order matches include/orangefs-types.h in the OrangeFS source. */
+static int PINT_errno_mapping[] = {
+	0, EPERM, ENOENT, EINTR, EIO, ENXIO, EBADF, EAGAIN, ENOMEM,
+	EFAULT, EBUSY, EEXIST, ENODEV, ENOTDIR, EISDIR, EINVAL, EMFILE,
+	EFBIG, ENOSPC, EROFS, EMLINK, EPIPE, EDEADLK, ENAMETOOLONG,
+	ENOLCK, ENOSYS, ENOTEMPTY, ELOOP, EWOULDBLOCK, ENOMSG, EUNATCH,
+	EBADR, EDEADLOCK, ENODATA, ETIME, ENONET, EREMOTE, ECOMM,
+	EPROTO, EBADMSG, EOVERFLOW, ERESTART, EMSGSIZE, EPROTOTYPE,
+	ENOPROTOOPT, EPROTONOSUPPORT, EOPNOTSUPP, EADDRINUSE,
+	EADDRNOTAVAIL, ENETDOWN, ENETUNREACH, ENETRESET, ENOBUFS,
+	ETIMEDOUT, ECONNREFUSED, EHOSTDOWN, EHOSTUNREACH, EALREADY,
+	EACCES, ECONNRESET, ERANGE
+};
+
+int orangefs_normalize_to_errno(__s32 error_code)
+{
+	__u32 i;
+
+	/* Success */
+	if (error_code == 0) {
+		return 0;
+	/*
+	 * This shouldn't ever happen. If it does it should be fixed on the
+	 * server.
+	 */
+	} else if (error_code > 0) {
+		gossip_err("orangefs: error status received.\n");
+		gossip_err("orangefs: assuming error code is inverted.\n");
+		error_code = -error_code;
+	}
+
+	/*
+	 * XXX: This is very bad since error codes from ORANGEFS may not be
+	 * suitable for return into userspace.
+	 */
+
+	/*
+	 * Convert ORANGEFS error values into errno values suitable for return
+	 * from the kernel.
+	 */
+	if ((-error_code) & ORANGEFS_NON_ERRNO_ERROR_BIT) {
+		if (((-error_code) &
+		    (ORANGEFS_ERROR_NUMBER_BITS|ORANGEFS_NON_ERRNO_ERROR_BIT|
+		    ORANGEFS_ERROR_BIT)) == ORANGEFS_ECANCEL) {
+			/*
+			 * cancellation error codes generally correspond to
+			 * a timeout from the client's perspective
+			 */
+			error_code = -ETIMEDOUT;
+		} else {
+			/* assume a default error code */
+			gossip_err("%s: bad error code :%d:.\n",
+				__func__,
+				error_code);
+			error_code = -EINVAL;
+		}
+
+	/* Convert ORANGEFS encoded errno values into regular errno values. */
+	} else if ((-error_code) & ORANGEFS_ERROR_BIT) {
+		i = (-error_code) & ~(ORANGEFS_ERROR_BIT|ORANGEFS_ERROR_CLASS_BITS);
+		if (i < ARRAY_SIZE(PINT_errno_mapping))
+			error_code = -PINT_errno_mapping[i];
+		else
+			error_code = -EINVAL;
+
+	/*
+	 * Only ORANGEFS protocol error codes should ever come here. Otherwise
+	 * there is a bug somewhere.
+	 */
+	} else {
+		gossip_err("%s: unknown error code.\n", __func__);
+		error_code = -EINVAL;
+	}
+	return error_code;
+}
+
+#define NUM_MODES 11
+__s32 ORANGEFS_util_translate_mode(int mode)
+{
+	int ret = 0;
+	int i = 0;
+	static int modes[NUM_MODES] = {
+		S_IXOTH, S_IWOTH, S_IROTH,
+		S_IXGRP, S_IWGRP, S_IRGRP,
+		S_IXUSR, S_IWUSR, S_IRUSR,
+		S_ISGID, S_ISUID
+	};
+	static int orangefs_modes[NUM_MODES] = {
+		ORANGEFS_O_EXECUTE, ORANGEFS_O_WRITE, ORANGEFS_O_READ,
+		ORANGEFS_G_EXECUTE, ORANGEFS_G_WRITE, ORANGEFS_G_READ,
+		ORANGEFS_U_EXECUTE, ORANGEFS_U_WRITE, ORANGEFS_U_READ,
+		ORANGEFS_G_SGID, ORANGEFS_U_SUID
+	};
+
+	for (i = 0; i < NUM_MODES; i++)
+		if (mode & modes[i])
+			ret |= orangefs_modes[i];
+
+	return ret;
+}
+#undef NUM_MODES
diff --git a/fs/orangefs/protocol.h b/fs/orangefs/protocol.h
new file mode 100644
index 000000000..d403cf29a
--- /dev/null
+++ b/fs/orangefs/protocol.h
@@ -0,0 +1,362 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/spinlock_types.h>
+#include <linux/slab.h>
+#include <linux/ioctl.h>
+
+/* khandle stuff  ***********************************************************/
+
+/*
+ * The 2.9 core will put 64 bit handles in here like this:
+ *    1234 0000 0000 5678
+ * The 3.0 and beyond cores will put 128 bit handles in here like this:
+ *    1234 5678 90AB CDEF
+ * The kernel module will always use the first four bytes and
+ * the last four bytes as an inum.
+ */
+struct orangefs_khandle {
+	unsigned char u[16];
+}  __aligned(8);
+
+/*
+ * kernel version of an object ref.
+ */
+struct orangefs_object_kref {
+	struct orangefs_khandle khandle;
+	__s32 fs_id;
+	__s32 __pad1;
+};
+
+/*
+ * compare 2 khandles assumes little endian thus from large address to
+ * small address
+ */
+static inline int ORANGEFS_khandle_cmp(const struct orangefs_khandle *kh1,
+				   const struct orangefs_khandle *kh2)
+{
+	int i;
+
+	for (i = 15; i >= 0; i--) {
+		if (kh1->u[i] > kh2->u[i])
+			return 1;
+		if (kh1->u[i] < kh2->u[i])
+			return -1;
+	}
+
+	return 0;
+}
+
+static inline void ORANGEFS_khandle_to(const struct orangefs_khandle *kh,
+				   void *p, int size)
+{
+
+	memcpy(p, kh->u, 16);
+	memset(p + 16, 0, size - 16);
+
+}
+
+static inline void ORANGEFS_khandle_from(struct orangefs_khandle *kh,
+				     void *p, int size)
+{
+	memset(kh, 0, 16);
+	memcpy(kh->u, p, 16);
+
+}
+
+/* pvfs2-types.h ************************************************************/
+
+#define ORANGEFS_SUPER_MAGIC 0x20030528
+
+/*
+ * ORANGEFS error codes are a signed 32-bit integer. Error codes are negative, but
+ * the sign is stripped before decoding.
+ */
+
+/* Bit 31 is not used since it is the sign. */
+
+/*
+ * Bit 30 specifies that this is a ORANGEFS error. A ORANGEFS error is either an
+ * encoded errno value or a ORANGEFS protocol error.
+ */
+#define ORANGEFS_ERROR_BIT (1 << 30)
+
+/*
+ * Bit 29 specifies that this is a ORANGEFS protocol error and not an encoded
+ * errno value.
+ */
+#define ORANGEFS_NON_ERRNO_ERROR_BIT (1 << 29)
+
+/*
+ * Bits 9, 8, and 7 specify the error class, which encodes the section of
+ * server code the error originated in for logging purposes. It is not used
+ * in the kernel except to be masked out.
+ */
+#define ORANGEFS_ERROR_CLASS_BITS 0x380
+
+/* Bits 6 - 0 are reserved for the actual error code. */
+#define ORANGEFS_ERROR_NUMBER_BITS 0x7f
+
+/* Encoded errno values decoded by PINT_errno_mapping in orangefs-utils.c. */
+
+/* Our own ORANGEFS protocol error codes. */
+#define ORANGEFS_ECANCEL    (1|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_EDEVINIT   (2|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_EDETAIL    (3|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_EHOSTNTFD  (4|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_EADDRNTFD  (5|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_ENORECVR   (6|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_ETRYAGAIN  (7|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_ENOTPVFS   (8|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+#define ORANGEFS_ESECURITY  (9|ORANGEFS_NON_ERRNO_ERROR_BIT|ORANGEFS_ERROR_BIT)
+
+/* permission bits */
+#define ORANGEFS_O_EXECUTE (1 << 0)
+#define ORANGEFS_O_WRITE   (1 << 1)
+#define ORANGEFS_O_READ    (1 << 2)
+#define ORANGEFS_G_EXECUTE (1 << 3)
+#define ORANGEFS_G_WRITE   (1 << 4)
+#define ORANGEFS_G_READ    (1 << 5)
+#define ORANGEFS_U_EXECUTE (1 << 6)
+#define ORANGEFS_U_WRITE   (1 << 7)
+#define ORANGEFS_U_READ    (1 << 8)
+/* no ORANGEFS_U_VTX (sticky bit) */
+#define ORANGEFS_G_SGID    (1 << 10)
+#define ORANGEFS_U_SUID    (1 << 11)
+
+#define ORANGEFS_ITERATE_START    2147483646
+#define ORANGEFS_ITERATE_END      2147483645
+#define ORANGEFS_IMMUTABLE_FL FS_IMMUTABLE_FL
+#define ORANGEFS_APPEND_FL    FS_APPEND_FL
+#define ORANGEFS_NOATIME_FL   FS_NOATIME_FL
+#define ORANGEFS_MIRROR_FL    0x01000000ULL
+#define ORANGEFS_FS_ID_NULL       ((__s32)0)
+#define ORANGEFS_ATTR_SYS_UID                   (1 << 0)
+#define ORANGEFS_ATTR_SYS_GID                   (1 << 1)
+#define ORANGEFS_ATTR_SYS_PERM                  (1 << 2)
+#define ORANGEFS_ATTR_SYS_ATIME                 (1 << 3)
+#define ORANGEFS_ATTR_SYS_CTIME                 (1 << 4)
+#define ORANGEFS_ATTR_SYS_MTIME                 (1 << 5)
+#define ORANGEFS_ATTR_SYS_TYPE                  (1 << 6)
+#define ORANGEFS_ATTR_SYS_ATIME_SET             (1 << 7)
+#define ORANGEFS_ATTR_SYS_MTIME_SET             (1 << 8)
+#define ORANGEFS_ATTR_SYS_SIZE                  (1 << 20)
+#define ORANGEFS_ATTR_SYS_LNK_TARGET            (1 << 24)
+#define ORANGEFS_ATTR_SYS_DFILE_COUNT           (1 << 25)
+#define ORANGEFS_ATTR_SYS_DIRENT_COUNT          (1 << 26)
+#define ORANGEFS_ATTR_SYS_BLKSIZE               (1 << 28)
+#define ORANGEFS_ATTR_SYS_MIRROR_COPIES_COUNT   (1 << 29)
+#define ORANGEFS_ATTR_SYS_COMMON_ALL	\
+	(ORANGEFS_ATTR_SYS_UID	|	\
+	 ORANGEFS_ATTR_SYS_GID	|	\
+	 ORANGEFS_ATTR_SYS_PERM	|	\
+	 ORANGEFS_ATTR_SYS_ATIME	|	\
+	 ORANGEFS_ATTR_SYS_CTIME	|	\
+	 ORANGEFS_ATTR_SYS_MTIME	|	\
+	 ORANGEFS_ATTR_SYS_TYPE)
+
+#define ORANGEFS_ATTR_SYS_ALL_SETABLE		\
+(ORANGEFS_ATTR_SYS_COMMON_ALL-ORANGEFS_ATTR_SYS_TYPE)
+
+#define ORANGEFS_ATTR_SYS_ALL_NOHINT			\
+	(ORANGEFS_ATTR_SYS_COMMON_ALL		|	\
+	 ORANGEFS_ATTR_SYS_SIZE			|	\
+	 ORANGEFS_ATTR_SYS_LNK_TARGET		|	\
+	 ORANGEFS_ATTR_SYS_DFILE_COUNT		|	\
+	 ORANGEFS_ATTR_SYS_MIRROR_COPIES_COUNT	|	\
+	 ORANGEFS_ATTR_SYS_DIRENT_COUNT		|	\
+	 ORANGEFS_ATTR_SYS_BLKSIZE)
+
+#define ORANGEFS_XATTR_REPLACE 0x2
+#define ORANGEFS_XATTR_CREATE  0x1
+#define ORANGEFS_MAX_SERVER_ADDR_LEN 256
+#define ORANGEFS_NAME_MAX                256
+/*
+ * max extended attribute name len as imposed by the VFS and exploited for the
+ * upcall request types.
+ * NOTE: Please retain them as multiples of 8 even if you wish to change them
+ * This is *NECESSARY* for supporting 32 bit user-space binaries on a 64-bit
+ * kernel. Due to implementation within DBPF, this really needs to be
+ * ORANGEFS_NAME_MAX, which it was the same value as, but no reason to let it
+ * break if that changes in the future.
+ */
+#define ORANGEFS_MAX_XATTR_NAMELEN   ORANGEFS_NAME_MAX	/* Not the same as
+						 * XATTR_NAME_MAX defined
+						 * by <linux/xattr.h>
+						 */
+#define ORANGEFS_MAX_XATTR_VALUELEN  8192	/* Not the same as XATTR_SIZE_MAX
+					 * defined by <linux/xattr.h>
+					 */
+#define ORANGEFS_MAX_XATTR_LISTLEN   16	/* Not the same as XATTR_LIST_MAX
+					 * defined by <linux/xattr.h>
+					 */
+/*
+ * ORANGEFS I/O operation types, used in both system and server interfaces.
+ */
+enum ORANGEFS_io_type {
+	ORANGEFS_IO_READ = 1,
+	ORANGEFS_IO_WRITE = 2
+};
+
+/*
+ * If this enum is modified the server parameters related to the precreate pool
+ * batch and low threshold sizes may need to be modified  to reflect this
+ * change.
+ */
+enum orangefs_ds_type {
+	ORANGEFS_TYPE_NONE = 0,
+	ORANGEFS_TYPE_METAFILE = (1 << 0),
+	ORANGEFS_TYPE_DATAFILE = (1 << 1),
+	ORANGEFS_TYPE_DIRECTORY = (1 << 2),
+	ORANGEFS_TYPE_SYMLINK = (1 << 3),
+	ORANGEFS_TYPE_DIRDATA = (1 << 4),
+	ORANGEFS_TYPE_INTERNAL = (1 << 5)	/* for the server's private use */
+};
+
+/* This structure is used by the VFS-client interaction alone */
+struct ORANGEFS_keyval_pair {
+	char key[ORANGEFS_MAX_XATTR_NAMELEN];
+	__s32 key_sz;	/* __s32 for portable, fixed-size structures */
+	__s32 val_sz;
+	char val[ORANGEFS_MAX_XATTR_VALUELEN];
+};
+
+/* pvfs2-sysint.h ***********************************************************/
+/* Describes attributes for a file, directory, or symlink. */
+struct ORANGEFS_sys_attr_s {
+	__u32 owner;
+	__u32 group;
+	__u32 perms;
+	__u64 atime;
+	__u64 mtime;
+	__u64 ctime;
+	__s64 size;
+
+	/* NOTE: caller must free if valid */
+	char *link_target;
+
+	/* Changed to __s32 so that size of structure does not change */
+	__s32 dfile_count;
+
+	/* Changed to __s32 so that size of structure does not change */
+	__s32 distr_dir_servers_initial;
+
+	/* Changed to __s32 so that size of structure does not change */
+	__s32 distr_dir_servers_max;
+
+	/* Changed to __s32 so that size of structure does not change */
+	__s32 distr_dir_split_size;
+
+	__u32 mirror_copies_count;
+
+	/* NOTE: caller must free if valid */
+	char *dist_name;
+
+	/* NOTE: caller must free if valid */
+	char *dist_params;
+
+	__s64 dirent_count;
+	enum orangefs_ds_type objtype;
+	__u64 flags;
+	__u32 mask;
+	__s64 blksize;
+};
+
+#define ORANGEFS_LOOKUP_LINK_NO_FOLLOW 0
+
+/* pint-dev.h ***************************************************************/
+
+/* parameter structure used in ORANGEFS_DEV_DEBUG ioctl command */
+struct dev_mask_info_s {
+	enum {
+		KERNEL_MASK,
+		CLIENT_MASK,
+	} mask_type;
+	__u64 mask_value;
+};
+
+struct dev_mask2_info_s {
+	__u64 mask1_value;
+	__u64 mask2_value;
+};
+
+/* pvfs2-util.h *************************************************************/
+__s32 ORANGEFS_util_translate_mode(int mode);
+
+/* pvfs2-debug.h ************************************************************/
+#include "orangefs-debug.h"
+
+/* pvfs2-internal.h *********************************************************/
+#define llu(x) (unsigned long long)(x)
+#define lld(x) (long long)(x)
+
+/* pint-dev-shared.h ********************************************************/
+#define ORANGEFS_DEV_MAGIC 'k'
+
+#define ORANGEFS_READDIR_DEFAULT_DESC_COUNT  5
+
+#define DEV_GET_MAGIC           0x1
+#define DEV_GET_MAX_UPSIZE      0x2
+#define DEV_GET_MAX_DOWNSIZE    0x3
+#define DEV_MAP                 0x4
+#define DEV_REMOUNT_ALL         0x5
+#define DEV_DEBUG               0x6
+#define DEV_UPSTREAM            0x7
+#define DEV_CLIENT_MASK         0x8
+#define DEV_CLIENT_STRING       0x9
+#define DEV_MAX_NR              0xa
+
+/* supported ioctls, codes are with respect to user-space */
+enum {
+	ORANGEFS_DEV_GET_MAGIC = _IOW(ORANGEFS_DEV_MAGIC, DEV_GET_MAGIC, __s32),
+	ORANGEFS_DEV_GET_MAX_UPSIZE =
+	    _IOW(ORANGEFS_DEV_MAGIC, DEV_GET_MAX_UPSIZE, __s32),
+	ORANGEFS_DEV_GET_MAX_DOWNSIZE =
+	    _IOW(ORANGEFS_DEV_MAGIC, DEV_GET_MAX_DOWNSIZE, __s32),
+	ORANGEFS_DEV_MAP = _IO(ORANGEFS_DEV_MAGIC, DEV_MAP),
+	ORANGEFS_DEV_REMOUNT_ALL = _IO(ORANGEFS_DEV_MAGIC, DEV_REMOUNT_ALL),
+	ORANGEFS_DEV_DEBUG = _IOR(ORANGEFS_DEV_MAGIC, DEV_DEBUG, __s32),
+	ORANGEFS_DEV_UPSTREAM = _IOW(ORANGEFS_DEV_MAGIC, DEV_UPSTREAM, int),
+	ORANGEFS_DEV_CLIENT_MASK = _IOW(ORANGEFS_DEV_MAGIC,
+				    DEV_CLIENT_MASK,
+				    struct dev_mask2_info_s),
+	ORANGEFS_DEV_CLIENT_STRING = _IOW(ORANGEFS_DEV_MAGIC,
+				      DEV_CLIENT_STRING,
+				      char *),
+	ORANGEFS_DEV_MAXNR = DEV_MAX_NR,
+};
+
+/*
+ * version number for use in communicating between kernel space and user
+ * space. Zero signifies the upstream version of the kernel module.
+ */
+#define ORANGEFS_KERNEL_PROTO_VERSION 0
+#define ORANGEFS_MINIMUM_USERSPACE_VERSION 20903
+
+/*
+ * describes memory regions to map in the ORANGEFS_DEV_MAP ioctl.
+ * NOTE: See devorangefs-req.c for 32 bit compat structure.
+ * Since this structure has a variable-sized layout that is different
+ * on 32 and 64 bit platforms, we need to normalize to a 64 bit layout
+ * on such systems before servicing ioctl calls from user-space binaries
+ * that may be 32 bit!
+ */
+struct ORANGEFS_dev_map_desc {
+	void __user *ptr;
+	__s32 total_size;
+	__s32 size;
+	__s32 count;
+};
+
+/* gossip.h *****************************************************************/
+
+extern __u64 orangefs_gossip_debug_mask;
+
+/* try to avoid function call overhead by checking masks in macro */
+#define gossip_debug(mask, fmt, ...)					\
+do {									\
+	if (orangefs_gossip_debug_mask & (mask))			\
+		printk(KERN_DEBUG fmt, ##__VA_ARGS__);			\
+} while (0)
+
+#define gossip_err pr_err
diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
new file mode 100644
index 000000000..4ec7329b4
--- /dev/null
+++ b/fs/orangefs/super.c
@@ -0,0 +1,664 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+#include <linux/hashtable.h>
+#include <linux/seq_file.h>
+
+/* a cache for orangefs-inode objects (i.e. orangefs inode private data) */
+static struct kmem_cache *orangefs_inode_cache;
+
+/* list for storing orangefs specific superblocks in use */
+LIST_HEAD(orangefs_superblocks);
+
+DEFINE_SPINLOCK(orangefs_superblocks_lock);
+
+enum {
+	Opt_acl,
+	Opt_intr,
+	Opt_local_lock,
+};
+
+const struct fs_parameter_spec orangefs_fs_param_spec[] = {
+	fsparam_flag	("acl",			Opt_acl),
+	fsparam_flag	("intr",		Opt_intr),
+	fsparam_flag	("local_lock",		Opt_local_lock),
+	{}
+};
+
+uint64_t orangefs_features;
+
+static int orangefs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct orangefs_sb_info_s *orangefs_sb = ORANGEFS_SB(root->d_sb);
+
+	if (root->d_sb->s_flags & SB_POSIXACL)
+		seq_puts(m, ",acl");
+	if (orangefs_sb->flags & ORANGEFS_OPT_INTR)
+		seq_puts(m, ",intr");
+	if (orangefs_sb->flags & ORANGEFS_OPT_LOCAL_LOCK)
+		seq_puts(m, ",local_lock");
+	return 0;
+}
+
+static int orangefs_parse_param(struct fs_context *fc,
+		struct fs_parameter *param)
+{
+	struct orangefs_sb_info_s *orangefs_sb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, orangefs_fs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_acl:
+		fc->sb_flags |= SB_POSIXACL;
+		break;
+	case Opt_intr:
+		orangefs_sb->flags |= ORANGEFS_OPT_INTR;
+		break;
+	case Opt_local_lock:
+		orangefs_sb->flags |= ORANGEFS_OPT_LOCAL_LOCK;
+		break;
+	}
+
+	return 0;
+}
+
+static void orangefs_inode_cache_ctor(void *req)
+{
+	struct orangefs_inode_s *orangefs_inode = req;
+
+	inode_init_once(&orangefs_inode->vfs_inode);
+	init_rwsem(&orangefs_inode->xattr_sem);
+}
+
+static struct inode *orangefs_alloc_inode(struct super_block *sb)
+{
+	struct orangefs_inode_s *orangefs_inode;
+
+	orangefs_inode = alloc_inode_sb(sb, orangefs_inode_cache, GFP_KERNEL);
+	if (!orangefs_inode)
+		return NULL;
+
+	/*
+	 * We want to clear everything except for rw_semaphore and the
+	 * vfs_inode.
+	 */
+	memset(&orangefs_inode->refn.khandle, 0, 16);
+	orangefs_inode->refn.fs_id = ORANGEFS_FS_ID_NULL;
+	orangefs_inode->last_failed_block_index_read = 0;
+	memset(orangefs_inode->link_target, 0, sizeof(orangefs_inode->link_target));
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "orangefs_alloc_inode: allocated %p\n",
+		     &orangefs_inode->vfs_inode);
+	return &orangefs_inode->vfs_inode;
+}
+
+static void orangefs_free_inode(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_cached_xattr *cx;
+	struct hlist_node *tmp;
+	int i;
+
+	hash_for_each_safe(orangefs_inode->xattr_cache, i, tmp, cx, node) {
+		hlist_del(&cx->node);
+		kfree(cx);
+	}
+
+	kmem_cache_free(orangefs_inode_cache, orangefs_inode);
+}
+
+static void orangefs_destroy_inode(struct inode *inode)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+			"%s: deallocated %p destroying inode %pU\n",
+			__func__, orangefs_inode, get_khandle_from_ino(inode));
+}
+
+static int orangefs_write_inode(struct inode *inode,
+				struct writeback_control *wbc)
+{
+	gossip_debug(GOSSIP_SUPER_DEBUG, "orangefs_write_inode\n");
+	return orangefs_inode_setattr(inode);
+}
+
+/*
+ * NOTE: information filled in here is typically reflected in the
+ * output of the system command 'df'
+*/
+static int orangefs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	int ret = -ENOMEM;
+	struct orangefs_kernel_op_s *new_op = NULL;
+	int flags = 0;
+	struct super_block *sb = NULL;
+
+	sb = dentry->d_sb;
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+			"%s: called on sb %p (fs_id is %d)\n",
+			__func__,
+			sb,
+			(int)(ORANGEFS_SB(sb)->fs_id));
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_STATFS);
+	if (!new_op)
+		return ret;
+	new_op->upcall.req.statfs.fs_id = ORANGEFS_SB(sb)->fs_id;
+
+	if (ORANGEFS_SB(sb)->flags & ORANGEFS_OPT_INTR)
+		flags = ORANGEFS_OP_INTERRUPTIBLE;
+
+	ret = service_operation(new_op, "orangefs_statfs", flags);
+
+	if (new_op->downcall.status < 0)
+		goto out_op_release;
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "%s: got %ld blocks available | "
+		     "%ld blocks total | %ld block size | "
+		     "%ld files total | %ld files avail\n",
+		     __func__,
+		     (long)new_op->downcall.resp.statfs.blocks_avail,
+		     (long)new_op->downcall.resp.statfs.blocks_total,
+		     (long)new_op->downcall.resp.statfs.block_size,
+		     (long)new_op->downcall.resp.statfs.files_total,
+		     (long)new_op->downcall.resp.statfs.files_avail);
+
+	buf->f_type = sb->s_magic;
+	buf->f_fsid.val[0] = ORANGEFS_SB(sb)->fs_id;
+	buf->f_fsid.val[1] = ORANGEFS_SB(sb)->id;
+	buf->f_bsize = new_op->downcall.resp.statfs.block_size;
+	buf->f_namelen = ORANGEFS_NAME_MAX;
+
+	buf->f_blocks = (sector_t) new_op->downcall.resp.statfs.blocks_total;
+	buf->f_bfree = (sector_t) new_op->downcall.resp.statfs.blocks_avail;
+	buf->f_bavail = (sector_t) new_op->downcall.resp.statfs.blocks_avail;
+	buf->f_files = (sector_t) new_op->downcall.resp.statfs.files_total;
+	buf->f_ffree = (sector_t) new_op->downcall.resp.statfs.files_avail;
+	buf->f_frsize = 0;
+
+out_op_release:
+	op_release(new_op);
+	gossip_debug(GOSSIP_SUPER_DEBUG, "%s: returning %d\n", __func__, ret);
+	return ret;
+}
+
+/*
+ * Remount as initiated by VFS layer.  We just need to reparse the mount
+ * options, no need to signal pvfs2-client-core about it.
+ */
+static int orangefs_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+	struct orangefs_sb_info_s *orangefs_sb = ORANGEFS_SB(sb);
+	struct orangefs_sb_info_s *revised = fc->s_fs_info;
+	unsigned int flags;
+
+	flags = orangefs_sb->flags;
+	flags &= ~(ORANGEFS_OPT_INTR | ORANGEFS_OPT_LOCAL_LOCK);
+	flags |= revised->flags;
+	WRITE_ONCE(orangefs_sb->flags, flags);
+
+	gossip_debug(GOSSIP_SUPER_DEBUG, "orangefs_reconfigure: called\n");
+	return 0;
+}
+
+/*
+ * Remount as initiated by pvfs2-client-core on restart.  This is used to
+ * repopulate mount information left from previous pvfs2-client-core.
+ *
+ * the idea here is that given a valid superblock, we're
+ * re-initializing the user space client with the initial mount
+ * information specified when the super block was first initialized.
+ * this is very different than the first initialization/creation of a
+ * superblock.  we use the special service_priority_operation to make
+ * sure that the mount gets ahead of any other pending operation that
+ * is waiting for servicing.  this means that the pvfs2-client won't
+ * fail to start several times for all other pending operations before
+ * the client regains all of the mount information from us.
+ * NOTE: this function assumes that the request_mutex is already acquired!
+ */
+int orangefs_remount(struct orangefs_sb_info_s *orangefs_sb)
+{
+	struct orangefs_kernel_op_s *new_op;
+	int ret = -EINVAL;
+
+	gossip_debug(GOSSIP_SUPER_DEBUG, "orangefs_remount: called\n");
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FS_MOUNT);
+	if (!new_op)
+		return -ENOMEM;
+	strscpy(new_op->upcall.req.fs_mount.orangefs_config_server,
+		orangefs_sb->devname);
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "Attempting ORANGEFS Remount via host %s\n",
+		     new_op->upcall.req.fs_mount.orangefs_config_server);
+
+	/*
+	 * we assume that the calling function has already acquired the
+	 * request_mutex to prevent other operations from bypassing
+	 * this one
+	 */
+	ret = service_operation(new_op, "orangefs_remount",
+		ORANGEFS_OP_PRIORITY | ORANGEFS_OP_NO_MUTEX);
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "orangefs_remount: mount got return value of %d\n",
+		     ret);
+	if (ret == 0) {
+		/*
+		 * store the id assigned to this sb -- it's just a
+		 * short-lived mapping that the system interface uses
+		 * to map this superblock to a particular mount entry
+		 */
+		orangefs_sb->id = new_op->downcall.resp.fs_mount.id;
+		orangefs_sb->mount_pending = 0;
+	}
+
+	op_release(new_op);
+
+	if (orangefs_userspace_version >= 20906) {
+		new_op = op_alloc(ORANGEFS_VFS_OP_FEATURES);
+		if (!new_op)
+			return -ENOMEM;
+		new_op->upcall.req.features.features = 0;
+		ret = service_operation(new_op, "orangefs_features",
+		    ORANGEFS_OP_PRIORITY | ORANGEFS_OP_NO_MUTEX);
+		if (!ret)
+			orangefs_features =
+			    new_op->downcall.resp.features.features;
+		else
+			orangefs_features = 0;
+		op_release(new_op);
+	} else {
+		orangefs_features = 0;
+	}
+
+	return ret;
+}
+
+int fsid_key_table_initialize(void)
+{
+	return 0;
+}
+
+void fsid_key_table_finalize(void)
+{
+}
+
+static const struct super_operations orangefs_s_ops = {
+	.alloc_inode = orangefs_alloc_inode,
+	.free_inode = orangefs_free_inode,
+	.destroy_inode = orangefs_destroy_inode,
+	.write_inode = orangefs_write_inode,
+	.drop_inode = inode_just_drop,
+	.statfs = orangefs_statfs,
+	.show_options = orangefs_show_options,
+};
+
+static struct dentry *orangefs_fh_to_dentry(struct super_block *sb,
+				  struct fid *fid,
+				  int fh_len,
+				  int fh_type)
+{
+	struct orangefs_object_kref refn;
+
+	if (fh_len < 5 || fh_type > 2)
+		return NULL;
+
+	ORANGEFS_khandle_from(&(refn.khandle), fid->raw, 16);
+	refn.fs_id = (u32) fid->raw[4];
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "fh_to_dentry: handle %pU, fs_id %d\n",
+		     &refn.khandle,
+		     refn.fs_id);
+
+	return d_obtain_alias(orangefs_iget(sb, &refn));
+}
+
+static int orangefs_encode_fh(struct inode *inode,
+		    __u32 *fh,
+		    int *max_len,
+		    struct inode *parent)
+{
+	int len = parent ? 10 : 5;
+	int type = 1;
+	struct orangefs_object_kref refn;
+
+	if (*max_len < len) {
+		gossip_err("fh buffer is too small for encoding\n");
+		*max_len = len;
+		type = 255;
+		goto out;
+	}
+
+	refn = ORANGEFS_I(inode)->refn;
+	ORANGEFS_khandle_to(&refn.khandle, fh, 16);
+	fh[4] = refn.fs_id;
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "Encoding fh: handle %pU, fsid %u\n",
+		     &refn.khandle,
+		     refn.fs_id);
+
+
+	if (parent) {
+		refn = ORANGEFS_I(parent)->refn;
+		ORANGEFS_khandle_to(&refn.khandle, (char *) fh + 20, 16);
+		fh[9] = refn.fs_id;
+
+		type = 2;
+		gossip_debug(GOSSIP_SUPER_DEBUG,
+			     "Encoding parent: handle %pU, fsid %u\n",
+			     &refn.khandle,
+			     refn.fs_id);
+	}
+	*max_len = len;
+
+out:
+	return type;
+}
+
+static const struct export_operations orangefs_export_ops = {
+	.encode_fh = orangefs_encode_fh,
+	.fh_to_dentry = orangefs_fh_to_dentry,
+};
+
+static int orangefs_unmount(int id, __s32 fs_id, const char *devname)
+{
+	struct orangefs_kernel_op_s *op;
+	int r;
+	op = op_alloc(ORANGEFS_VFS_OP_FS_UMOUNT);
+	if (!op)
+		return -ENOMEM;
+	op->upcall.req.fs_umount.id = id;
+	op->upcall.req.fs_umount.fs_id = fs_id;
+	strscpy(op->upcall.req.fs_umount.orangefs_config_server, devname);
+	r = service_operation(op, "orangefs_fs_umount", 0);
+	/* Not much to do about an error here. */
+	if (r)
+		gossip_err("orangefs_unmount: service_operation %d\n", r);
+	op_release(op);
+	return r;
+}
+
+static int orangefs_fill_sb(struct super_block *sb,
+			    struct fs_context *fc,
+			    struct orangefs_fs_mount_response *fs_mount)
+{
+	int ret;
+	struct inode *root;
+	struct dentry *root_dentry;
+	struct orangefs_object_kref root_object;
+
+	ORANGEFS_SB(sb)->sb = sb;
+
+	ORANGEFS_SB(sb)->root_khandle = fs_mount->root_khandle;
+	ORANGEFS_SB(sb)->fs_id = fs_mount->fs_id;
+	ORANGEFS_SB(sb)->id = fs_mount->id;
+
+	/* Hang the xattr handlers off the superblock */
+	sb->s_xattr = orangefs_xattr_handlers;
+	sb->s_magic = ORANGEFS_SUPER_MAGIC;
+	sb->s_op = &orangefs_s_ops;
+	set_default_d_op(sb, &orangefs_dentry_operations);
+
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+
+	ret = super_setup_bdi(sb);
+	if (ret)
+		return ret;
+
+	root_object.khandle = ORANGEFS_SB(sb)->root_khandle;
+	root_object.fs_id = ORANGEFS_SB(sb)->fs_id;
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "get inode %pU, fsid %d\n",
+		     &root_object.khandle,
+		     root_object.fs_id);
+
+	root = orangefs_iget(sb, &root_object);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "Allocated root inode [%p] with mode %x\n",
+		     root,
+		     root->i_mode);
+
+	/* allocates and places root dentry in dcache */
+	root_dentry = d_make_root(root);
+	if (!root_dentry)
+		return -ENOMEM;
+
+	sb->s_export_op = &orangefs_export_ops;
+	sb->s_root = root_dentry;
+	return 0;
+}
+
+static int orangefs_get_tree(struct fs_context *fc)
+{
+	int ret;
+	struct super_block *sb = ERR_PTR(-EINVAL);
+	struct orangefs_kernel_op_s *new_op;
+
+	if (!fc->source)
+		return invalf(fc, "Device name not specified.\n");
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "orangefs_mount: called with devname %s\n",
+		     fc->source);
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_FS_MOUNT);
+	if (!new_op)
+		return -ENOMEM;
+
+	strscpy(new_op->upcall.req.fs_mount.orangefs_config_server, fc->source);
+
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "Attempting ORANGEFS Mount via host %s\n",
+		     new_op->upcall.req.fs_mount.orangefs_config_server);
+
+	ret = service_operation(new_op, "orangefs_mount", 0);
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "orangefs_mount: mount got return value of %d\n", ret);
+	if (ret)
+		goto free_op;
+
+	if (new_op->downcall.resp.fs_mount.fs_id == ORANGEFS_FS_ID_NULL) {
+		gossip_err("ERROR: Retrieved null fs_id\n");
+		ret = -EINVAL;
+		goto free_op;
+	}
+
+	sb = sget_fc(fc, NULL, set_anon_super_fc);
+
+	if (IS_ERR(sb)) {
+		ret = PTR_ERR(sb);
+		orangefs_unmount(new_op->downcall.resp.fs_mount.id,
+				 new_op->downcall.resp.fs_mount.fs_id,
+				 fc->source);
+		goto free_op;
+	}
+
+	/* init our private orangefs sb info */
+	ret = orangefs_fill_sb(sb, fc, &new_op->downcall.resp.fs_mount);
+
+	if (ret)
+		goto free_sb_and_op;
+
+	/*
+	 * on successful mount, store the devname and data
+	 * used
+	 */
+	strscpy(ORANGEFS_SB(sb)->devname, fc->source);
+
+	/* mount_pending must be cleared */
+	ORANGEFS_SB(sb)->mount_pending = 0;
+
+	/*
+	 * finally, add this sb to our list of known orangefs
+	 * sb's
+	 */
+	gossip_debug(GOSSIP_SUPER_DEBUG,
+		     "Adding SB %p to orangefs superblocks\n",
+		     ORANGEFS_SB(sb));
+	spin_lock(&orangefs_superblocks_lock);
+	list_add_tail(&ORANGEFS_SB(sb)->list, &orangefs_superblocks);
+	spin_unlock(&orangefs_superblocks_lock);
+	op_release(new_op);
+
+	/* Must be removed from the list now. */
+	ORANGEFS_SB(sb)->no_list = 0;
+
+	if (orangefs_userspace_version >= 20906) {
+		new_op = op_alloc(ORANGEFS_VFS_OP_FEATURES);
+		if (!new_op)
+			return -ENOMEM;
+		new_op->upcall.req.features.features = 0;
+		ret = service_operation(new_op, "orangefs_features", 0);
+		orangefs_features = new_op->downcall.resp.features.features;
+		op_release(new_op);
+	} else {
+		orangefs_features = 0;
+	}
+
+	fc->root = dget(sb->s_root);
+	return 0;
+
+free_sb_and_op:
+	/* Will call orangefs_kill_sb with sb not in list. */
+	ORANGEFS_SB(sb)->no_list = 1;
+	/* ORANGEFS_VFS_OP_FS_UMOUNT is done by orangefs_kill_sb. */
+	deactivate_locked_super(sb);
+free_op:
+	gossip_err("orangefs_mount: mount request failed with %d\n", ret);
+	if (ret == -EINVAL) {
+		gossip_err("Ensure that all orangefs-servers have the same FS configuration files\n");
+		gossip_err("Look at pvfs2-client-core log file (typically /tmp/pvfs2-client.log) for more details\n");
+	}
+
+	op_release(new_op);
+
+	return ret;
+}
+
+static void orangefs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations orangefs_context_ops = {
+	.free		= orangefs_free_fc,
+	.parse_param	= orangefs_parse_param,
+	.get_tree	= orangefs_get_tree,
+	.reconfigure	= orangefs_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+int orangefs_init_fs_context(struct fs_context *fc)
+{
+	struct orangefs_sb_info_s *osi;
+
+	osi = kzalloc_obj(struct orangefs_sb_info_s);
+	if (!osi)
+		return -ENOMEM;
+
+	/*
+	 * Force any potential flags that might be set from the mount
+	 * to zero, ie, initialize to unset.
+	 */
+	fc->sb_flags_mask &= ~SB_POSIXACL;
+	osi->flags &= ~ORANGEFS_OPT_INTR;
+	osi->flags &= ~ORANGEFS_OPT_LOCAL_LOCK;
+
+	fc->s_fs_info = osi;
+	fc->ops = &orangefs_context_ops;
+	return 0;
+}
+
+void orangefs_kill_sb(struct super_block *sb)
+{
+	int r;
+	gossip_debug(GOSSIP_SUPER_DEBUG, "orangefs_kill_sb: called\n");
+
+	/* provided sb cleanup */
+	kill_anon_super(sb);
+
+	if (!ORANGEFS_SB(sb)) {
+		mutex_lock(&orangefs_request_mutex);
+		mutex_unlock(&orangefs_request_mutex);
+		return;
+	}
+	/*
+	 * issue the unmount to userspace to tell it to remove the
+	 * dynamic mount info it has for this superblock
+	 */
+	r = orangefs_unmount(ORANGEFS_SB(sb)->id, ORANGEFS_SB(sb)->fs_id,
+	    ORANGEFS_SB(sb)->devname);
+	if (!r)
+		ORANGEFS_SB(sb)->mount_pending = 1;
+
+	if (!ORANGEFS_SB(sb)->no_list) {
+		/* remove the sb from our list of orangefs specific sb's */
+		spin_lock(&orangefs_superblocks_lock);
+		/* not list_del_init */
+		__list_del_entry(&ORANGEFS_SB(sb)->list);
+		ORANGEFS_SB(sb)->list.prev = NULL;
+		spin_unlock(&orangefs_superblocks_lock);
+	}
+
+	/*
+	 * make sure that ORANGEFS_DEV_REMOUNT_ALL loop that might've seen us
+	 * gets completed before we free the dang thing.
+	 */
+	mutex_lock(&orangefs_request_mutex);
+	mutex_unlock(&orangefs_request_mutex);
+
+	/* free the orangefs superblock private data */
+	kfree(ORANGEFS_SB(sb));
+}
+
+int orangefs_inode_cache_initialize(void)
+{
+	orangefs_inode_cache = kmem_cache_create_usercopy(
+					"orangefs_inode_cache",
+					sizeof(struct orangefs_inode_s),
+					0,
+					0,
+					offsetof(struct orangefs_inode_s,
+						link_target),
+					sizeof_field(struct orangefs_inode_s,
+						link_target),
+					orangefs_inode_cache_ctor);
+
+	if (!orangefs_inode_cache) {
+		gossip_err("Cannot create orangefs_inode_cache\n");
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+int orangefs_inode_cache_finalize(void)
+{
+	kmem_cache_destroy(orangefs_inode_cache);
+	return 0;
+}
diff --git a/fs/orangefs/symlink.c b/fs/orangefs/symlink.c
new file mode 100644
index 000000000..db107fe91
--- /dev/null
+++ b/fs/orangefs/symlink.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+const struct inode_operations orangefs_symlink_inode_operations = {
+	.get_link = simple_get_link,
+	.setattr = orangefs_setattr,
+	.getattr = orangefs_getattr,
+	.listxattr = orangefs_listxattr,
+	.permission = orangefs_permission,
+	.update_time = orangefs_update_time,
+};
diff --git a/fs/orangefs/upcall.h b/fs/orangefs/upcall.h
new file mode 100644
index 000000000..16118452a
--- /dev/null
+++ b/fs/orangefs/upcall.h
@@ -0,0 +1,260 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+#ifndef __UPCALL_H
+#define __UPCALL_H
+
+/*
+ * Sanitized this header file to fix
+ * 32-64 bit interaction issues between
+ * client-core and device
+ */
+struct orangefs_io_request_s {
+	__s32 __pad1;
+	__s32 buf_index;
+	__s32 count;
+	__s32 __pad2;
+	__s64 offset;
+	struct orangefs_object_kref refn;
+	enum ORANGEFS_io_type io_type;
+	__s32 readahead_size;
+};
+
+struct orangefs_lookup_request_s {
+	__s32 sym_follow;
+	__s32 __pad1;
+	struct orangefs_object_kref parent_refn;
+	char d_name[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_create_request_s {
+	struct orangefs_object_kref parent_refn;
+	struct ORANGEFS_sys_attr_s attributes;
+	char d_name[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_symlink_request_s {
+	struct orangefs_object_kref parent_refn;
+	struct ORANGEFS_sys_attr_s attributes;
+	char entry_name[ORANGEFS_NAME_MAX];
+	char target[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_getattr_request_s {
+	struct orangefs_object_kref refn;
+	__u32 mask;
+	__u32 __pad1;
+};
+
+struct orangefs_setattr_request_s {
+	struct orangefs_object_kref refn;
+	struct ORANGEFS_sys_attr_s attributes;
+};
+
+struct orangefs_remove_request_s {
+	struct orangefs_object_kref parent_refn;
+	char d_name[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_mkdir_request_s {
+	struct orangefs_object_kref parent_refn;
+	struct ORANGEFS_sys_attr_s attributes;
+	char d_name[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_readdir_request_s {
+	struct orangefs_object_kref refn;
+	__u64 token;
+	__s32 max_dirent_count;
+	__s32 buf_index;
+};
+
+struct orangefs_readdirplus_request_s {
+	struct orangefs_object_kref refn;
+	__u64 token;
+	__s32 max_dirent_count;
+	__u32 mask;
+	__s32 buf_index;
+	__s32 __pad1;
+};
+
+struct orangefs_rename_request_s {
+	struct orangefs_object_kref old_parent_refn;
+	struct orangefs_object_kref new_parent_refn;
+	char d_old_name[ORANGEFS_NAME_MAX];
+	char d_new_name[ORANGEFS_NAME_MAX];
+};
+
+struct orangefs_statfs_request_s {
+	__s32 fs_id;
+	__s32 __pad1;
+};
+
+struct orangefs_truncate_request_s {
+	struct orangefs_object_kref refn;
+	__s64 size;
+};
+
+struct orangefs_ra_cache_flush_request_s {
+	struct orangefs_object_kref refn;
+};
+
+struct orangefs_fs_mount_request_s {
+	char orangefs_config_server[ORANGEFS_MAX_SERVER_ADDR_LEN];
+};
+
+struct orangefs_fs_umount_request_s {
+	__s32 id;
+	__s32 fs_id;
+	char orangefs_config_server[ORANGEFS_MAX_SERVER_ADDR_LEN];
+};
+
+struct orangefs_getxattr_request_s {
+	struct orangefs_object_kref refn;
+	__s32 key_sz;
+	__s32 __pad1;
+	char key[ORANGEFS_MAX_XATTR_NAMELEN];
+};
+
+struct orangefs_setxattr_request_s {
+	struct orangefs_object_kref refn;
+	struct ORANGEFS_keyval_pair keyval;
+	__s32 flags;
+	__s32 __pad1;
+};
+
+struct orangefs_listxattr_request_s {
+	struct orangefs_object_kref refn;
+	__s32 requested_count;
+	__s32 __pad1;
+	__u64 token;
+};
+
+struct orangefs_removexattr_request_s {
+	struct orangefs_object_kref refn;
+	__s32 key_sz;
+	__s32 __pad1;
+	char key[ORANGEFS_MAX_XATTR_NAMELEN];
+};
+
+struct orangefs_op_cancel_s {
+	__u64 op_tag;
+};
+
+struct orangefs_fsync_request_s {
+	struct orangefs_object_kref refn;
+};
+
+enum orangefs_param_request_type {
+	ORANGEFS_PARAM_REQUEST_SET = 1,
+	ORANGEFS_PARAM_REQUEST_GET = 2
+};
+
+enum orangefs_param_request_op {
+	ORANGEFS_PARAM_REQUEST_OP_ACACHE_TIMEOUT_MSECS = 1,
+	ORANGEFS_PARAM_REQUEST_OP_ACACHE_HARD_LIMIT = 2,
+	ORANGEFS_PARAM_REQUEST_OP_ACACHE_SOFT_LIMIT = 3,
+	ORANGEFS_PARAM_REQUEST_OP_ACACHE_RECLAIM_PERCENTAGE = 4,
+	ORANGEFS_PARAM_REQUEST_OP_PERF_TIME_INTERVAL_SECS = 5,
+	ORANGEFS_PARAM_REQUEST_OP_PERF_HISTORY_SIZE = 6,
+	ORANGEFS_PARAM_REQUEST_OP_PERF_RESET = 7,
+	ORANGEFS_PARAM_REQUEST_OP_NCACHE_TIMEOUT_MSECS = 8,
+	ORANGEFS_PARAM_REQUEST_OP_NCACHE_HARD_LIMIT = 9,
+	ORANGEFS_PARAM_REQUEST_OP_NCACHE_SOFT_LIMIT = 10,
+	ORANGEFS_PARAM_REQUEST_OP_NCACHE_RECLAIM_PERCENTAGE = 11,
+	ORANGEFS_PARAM_REQUEST_OP_STATIC_ACACHE_TIMEOUT_MSECS = 12,
+	ORANGEFS_PARAM_REQUEST_OP_STATIC_ACACHE_HARD_LIMIT = 13,
+	ORANGEFS_PARAM_REQUEST_OP_STATIC_ACACHE_SOFT_LIMIT = 14,
+	ORANGEFS_PARAM_REQUEST_OP_STATIC_ACACHE_RECLAIM_PERCENTAGE = 15,
+	ORANGEFS_PARAM_REQUEST_OP_CLIENT_DEBUG = 16,
+	ORANGEFS_PARAM_REQUEST_OP_CCACHE_TIMEOUT_SECS = 17,
+	ORANGEFS_PARAM_REQUEST_OP_CCACHE_HARD_LIMIT = 18,
+	ORANGEFS_PARAM_REQUEST_OP_CCACHE_SOFT_LIMIT = 19,
+	ORANGEFS_PARAM_REQUEST_OP_CCACHE_RECLAIM_PERCENTAGE = 20,
+	ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_TIMEOUT_SECS = 21,
+	ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_HARD_LIMIT = 22,
+	ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_SOFT_LIMIT = 23,
+	ORANGEFS_PARAM_REQUEST_OP_CAPCACHE_RECLAIM_PERCENTAGE = 24,
+	ORANGEFS_PARAM_REQUEST_OP_TWO_MASK_VALUES = 25,
+	ORANGEFS_PARAM_REQUEST_OP_READAHEAD_SIZE = 26,
+	ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT = 27,
+	ORANGEFS_PARAM_REQUEST_OP_READAHEAD_COUNT_SIZE = 28,
+	ORANGEFS_PARAM_REQUEST_OP_READAHEAD_READCNT = 29,
+};
+
+struct orangefs_param_request_s {
+	enum orangefs_param_request_type type;
+	enum orangefs_param_request_op op;
+	union {
+		__s64 value64;
+		__s32 value32[2];
+	} u;
+	char s_value[ORANGEFS_MAX_DEBUG_STRING_LEN];
+};
+
+enum orangefs_perf_count_request_type {
+	ORANGEFS_PERF_COUNT_REQUEST_ACACHE = 1,
+	ORANGEFS_PERF_COUNT_REQUEST_NCACHE = 2,
+	ORANGEFS_PERF_COUNT_REQUEST_CAPCACHE = 3,
+};
+
+struct orangefs_perf_count_request_s {
+	enum orangefs_perf_count_request_type type;
+	__s32 __pad1;
+};
+
+struct orangefs_fs_key_request_s {
+	__s32 fsid;
+	__s32 __pad1;
+};
+
+/* 2.9.6 */
+struct orangefs_features_request_s {
+	__u64 features;
+};
+
+struct orangefs_upcall_s {
+	__s32 type;
+	__u32 uid;
+	__u32 gid;
+	int pid;
+	int tgid;
+	/* Trailers unused but must be retained for protocol compatibility. */
+	__s64 trailer_size;
+	char *trailer_buf;
+
+	union {
+		struct orangefs_io_request_s io;
+		struct orangefs_lookup_request_s lookup;
+		struct orangefs_create_request_s create;
+		struct orangefs_symlink_request_s sym;
+		struct orangefs_getattr_request_s getattr;
+		struct orangefs_setattr_request_s setattr;
+		struct orangefs_remove_request_s remove;
+		struct orangefs_mkdir_request_s mkdir;
+		struct orangefs_readdir_request_s readdir;
+		struct orangefs_readdirplus_request_s readdirplus;
+		struct orangefs_rename_request_s rename;
+		struct orangefs_statfs_request_s statfs;
+		struct orangefs_truncate_request_s truncate;
+		struct orangefs_ra_cache_flush_request_s ra_cache_flush;
+		struct orangefs_fs_mount_request_s fs_mount;
+		struct orangefs_fs_umount_request_s fs_umount;
+		struct orangefs_getxattr_request_s getxattr;
+		struct orangefs_setxattr_request_s setxattr;
+		struct orangefs_listxattr_request_s listxattr;
+		struct orangefs_removexattr_request_s removexattr;
+		struct orangefs_op_cancel_s cancel;
+		struct orangefs_fsync_request_s fsync;
+		struct orangefs_param_request_s param;
+		struct orangefs_perf_count_request_s perf_count;
+		struct orangefs_fs_key_request_s fs_key;
+		struct orangefs_features_request_s features;
+	} req;
+};
+
+#endif /* __UPCALL_H */
diff --git a/fs/orangefs/waitqueue.c b/fs/orangefs/waitqueue.c
new file mode 100644
index 000000000..beafc33d5
--- /dev/null
+++ b/fs/orangefs/waitqueue.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * (C) 2011 Omnibond Systems
+ *
+ * Changes by Acxiom Corporation to implement generic service_operation()
+ * function, Copyright Acxiom Corporation, 2005.
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  In-kernel waitqueue operations.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+
+static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,
+		long timeout,
+		int flags)
+			__acquires(op->lock);
+static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
+	__releases(op->lock);
+
+/*
+ * What we do in this function is to walk the list of operations that are
+ * present in the request queue and mark them as purged.
+ * NOTE: This is called from the device close after client-core has
+ * guaranteed that no new operations could appear on the list since the
+ * client-core is anyway going to exit.
+ */
+void purge_waiting_ops(void)
+{
+	struct orangefs_kernel_op_s *op, *tmp;
+
+	spin_lock(&orangefs_request_list_lock);
+	list_for_each_entry_safe(op, tmp, &orangefs_request_list, list) {
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "pvfs2-client-core: purging op tag %llu %s\n",
+			     llu(op->tag),
+			     get_opname_string(op));
+		set_op_state_purged(op);
+		gossip_debug(GOSSIP_DEV_DEBUG,
+			     "%s: op:%s: op_state:%d: process:%s:\n",
+			     __func__,
+			     get_opname_string(op),
+			     op->op_state,
+			     current->comm);
+	}
+	spin_unlock(&orangefs_request_list_lock);
+}
+
+/*
+ * submits a ORANGEFS operation and waits for it to complete
+ *
+ * Note op->downcall.status will contain the status of the operation (in
+ * errno format), whether provided by pvfs2-client or a result of failure to
+ * service the operation.  If the caller wishes to distinguish, then
+ * op->state can be checked to see if it was serviced or not.
+ *
+ * Returns contents of op->downcall.status for convenience
+ */
+int service_operation(struct orangefs_kernel_op_s *op,
+		      const char *op_name,
+		      int flags)
+{
+	long timeout = MAX_SCHEDULE_TIMEOUT;
+	int ret = 0;
+
+	DEFINE_WAIT(wait_entry);
+
+	op->upcall.tgid = current->tgid;
+	op->upcall.pid = current->pid;
+
+retry_servicing:
+	op->downcall.status = 0;
+	gossip_debug(GOSSIP_WAIT_DEBUG,
+		     "%s: %s op:%p: process:%s: pid:%d:\n",
+		     __func__,
+		     op_name,
+		     op,
+		     current->comm,
+		     current->pid);
+
+	/*
+	 * If ORANGEFS_OP_NO_MUTEX was set in flags, we need to avoid
+	 * acquiring the request_mutex because we're servicing a
+	 * high priority remount operation and the request_mutex is
+	 * already taken.
+	 */
+	if (!(flags & ORANGEFS_OP_NO_MUTEX)) {
+		if (flags & ORANGEFS_OP_INTERRUPTIBLE)
+			ret = mutex_lock_interruptible(&orangefs_request_mutex);
+		else
+			ret = mutex_lock_killable(&orangefs_request_mutex);
+		/*
+		 * check to see if we were interrupted while waiting for
+		 * mutex
+		 */
+		if (ret < 0) {
+			op->downcall.status = ret;
+			gossip_debug(GOSSIP_WAIT_DEBUG,
+				     "%s: service_operation interrupted.\n",
+				     __func__);
+			return ret;
+		}
+	}
+
+	/* queue up the operation */
+	spin_lock(&orangefs_request_list_lock);
+	spin_lock(&op->lock);
+	set_op_state_waiting(op);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s: op:%s: op_state:%d: process:%s:\n",
+		     __func__,
+		     get_opname_string(op),
+		     op->op_state,
+		     current->comm);
+	/* add high priority remount op to the front of the line. */
+	if (flags & ORANGEFS_OP_PRIORITY)
+		list_add(&op->list, &orangefs_request_list);
+	else
+		list_add_tail(&op->list, &orangefs_request_list);
+	spin_unlock(&op->lock);
+	wake_up_interruptible(&orangefs_request_list_waitq);
+	if (!__is_daemon_in_service()) {
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "%s:client core is NOT in service.\n",
+			     __func__);
+		/*
+		 * Don't wait for the userspace component to return if
+		 * the filesystem is being umounted anyway.
+		 */
+		if (op->upcall.type == ORANGEFS_VFS_OP_FS_UMOUNT)
+			timeout = 0;
+		else
+			timeout = op_timeout_secs * HZ;
+	}
+	spin_unlock(&orangefs_request_list_lock);
+
+	if (!(flags & ORANGEFS_OP_NO_MUTEX))
+		mutex_unlock(&orangefs_request_mutex);
+
+	ret = wait_for_matching_downcall(op, timeout, flags);
+	gossip_debug(GOSSIP_WAIT_DEBUG,
+		     "%s: wait_for_matching_downcall returned %d for %p\n",
+		     __func__,
+		     ret,
+		     op);
+
+	/* got matching downcall; make sure status is in errno format */
+	if (!ret) {
+		spin_unlock(&op->lock);
+		op->downcall.status =
+		    orangefs_normalize_to_errno(op->downcall.status);
+		ret = op->downcall.status;
+		goto out;
+	}
+
+	/* failed to get matching downcall */
+	if (ret == -ETIMEDOUT) {
+		gossip_err("%s: %s -- wait timed out; aborting attempt.\n",
+			   __func__,
+			   op_name);
+	}
+
+	/*
+	 * remove a waiting op from the request list or
+	 * remove an in-progress op from the in-progress list.
+	 */
+	orangefs_clean_up_interrupted_operation(op);
+
+	op->downcall.status = ret;
+	/* retry if operation has not been serviced and if requested */
+	if (ret == -EAGAIN) {
+		op->attempts++;
+		timeout = op_timeout_secs * HZ;
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "orangefs: tag %llu (%s)"
+			     " -- operation to be retried (%d attempt)\n",
+			     llu(op->tag),
+			     op_name,
+			     op->attempts);
+
+		/*
+		 * io ops (ops that use the shared memory buffer) have
+		 * to be returned to their caller for a retry. Other ops
+		 * can just be recycled here.
+		 */
+		if (!op->uses_shared_memory)
+			goto retry_servicing;
+	}
+
+out:
+	gossip_debug(GOSSIP_WAIT_DEBUG,
+		     "%s: %s returning: %d for %p.\n",
+		     __func__,
+		     op_name,
+		     ret,
+		     op);
+	return ret;
+}
+
+/* This can get called on an I/O op if it had a bad service_operation. */
+bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op)
+{
+	u64 tag = op->tag;
+	if (!op_state_in_progress(op))
+		return false;
+
+	op->slot_to_free = op->upcall.req.io.buf_index;
+	memset(&op->upcall, 0, sizeof(op->upcall));
+	memset(&op->downcall, 0, sizeof(op->downcall));
+	op->upcall.type = ORANGEFS_VFS_OP_CANCEL;
+	op->upcall.req.cancel.op_tag = tag;
+	op->downcall.type = ORANGEFS_VFS_OP_INVALID;
+	op->downcall.status = -1;
+	orangefs_new_tag(op);
+
+	spin_lock(&orangefs_request_list_lock);
+	/* orangefs_request_list_lock is enough of a barrier here */
+	if (!__is_daemon_in_service()) {
+		spin_unlock(&orangefs_request_list_lock);
+		return false;
+	}
+	spin_lock(&op->lock);
+	set_op_state_waiting(op);
+	gossip_debug(GOSSIP_DEV_DEBUG,
+		     "%s: op:%s: op_state:%d: process:%s:\n",
+		     __func__,
+		     get_opname_string(op),
+		     op->op_state,
+		     current->comm);
+	list_add(&op->list, &orangefs_request_list);
+	spin_unlock(&op->lock);
+	spin_unlock(&orangefs_request_list_lock);
+
+	gossip_debug(GOSSIP_WAIT_DEBUG,
+		     "Attempting ORANGEFS operation cancellation of tag %llu\n",
+		     llu(tag));
+	return true;
+}
+
+/*
+ * Change an op to the "given up" state and remove it from its list.
+ */
+static void
+	orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
+		__releases(op->lock)
+{
+	/*
+	 * handle interrupted cases depending on what state we were in when
+	 * the interruption is detected.
+	 *
+	 * Called with op->lock held.
+	 */
+
+	/*
+	 * List manipulation code elsewhere will ignore ops that
+	 * have been given up upon.
+	 */
+	op->op_state |= OP_VFS_STATE_GIVEN_UP;
+
+	if (list_empty(&op->list)) {
+		/* caught copying to/from daemon */
+		BUG_ON(op_state_serviced(op));
+		spin_unlock(&op->lock);
+		wait_for_completion(&op->waitq);
+	} else if (op_state_waiting(op)) {
+		/*
+		 * upcall hasn't been read; remove op from upcall request
+		 * list.
+		 */
+		spin_unlock(&op->lock);
+		spin_lock(&orangefs_request_list_lock);
+		list_del_init(&op->list);
+		spin_unlock(&orangefs_request_list_lock);
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "Interrupted: Removed op %p from request_list\n",
+			     op);
+	} else if (op_state_in_progress(op)) {
+		/* op must be removed from the in progress htable */
+		spin_unlock(&op->lock);
+		spin_lock(&orangefs_htable_ops_in_progress_lock);
+		list_del_init(&op->list);
+		spin_unlock(&orangefs_htable_ops_in_progress_lock);
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "Interrupted: Removed op %p"
+			     " from htable_ops_in_progress\n",
+			     op);
+	} else {
+		spin_unlock(&op->lock);
+		gossip_err("interrupted operation is in a weird state 0x%x\n",
+			   op->op_state);
+	}
+	reinit_completion(&op->waitq);
+}
+
+/*
+ * Sleeps on waitqueue waiting for matching downcall.
+ * If client-core finishes servicing, then we are good to go.
+ * else if client-core exits, we get woken up here, and retry with a timeout
+ *
+ * When this call returns to the caller, the specified op will no
+ * longer be in either the in_progress hash table or on the request list.
+ *
+ * Returns 0 on success and -errno on failure
+ * Errors are:
+ * EAGAIN in case we want the caller to requeue and try again..
+ * EINTR/EIO/ETIMEDOUT indicating we are done trying to service this
+ * operation since client-core seems to be exiting too often
+ * or if we were interrupted.
+ *
+ * Returns with op->lock taken.
+ */
+static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,
+		long timeout,
+		int flags)
+			__acquires(op->lock)
+{
+	long n;
+	int writeback = flags & ORANGEFS_OP_WRITEBACK,
+	    interruptible = flags & ORANGEFS_OP_INTERRUPTIBLE;
+
+	/*
+	 * There's a "schedule_timeout" inside of these wait
+	 * primitives, during which the op is out of the hands of the
+	 * user process that needs something done and is being
+	 * manipulated by the client-core process.
+	 */
+	if (writeback)
+		n = wait_for_completion_io_timeout(&op->waitq, timeout);
+	else if (!writeback && interruptible)
+		n = wait_for_completion_interruptible_timeout(&op->waitq,
+								      timeout);
+	else /* !writeback && !interruptible but compiler complains */
+		n = wait_for_completion_killable_timeout(&op->waitq, timeout);
+
+	spin_lock(&op->lock);
+
+	if (op_state_serviced(op))
+		return 0;
+
+	if (unlikely(n < 0)) {
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "%s: operation interrupted, tag %llu, %p\n",
+			     __func__,
+			     llu(op->tag),
+			     op);
+		return -EINTR;
+	}
+	if (op_state_purged(op)) {
+		gossip_debug(GOSSIP_WAIT_DEBUG,
+			     "%s: operation purged, tag %llu, %p, %d\n",
+			     __func__,
+			     llu(op->tag),
+			     op,
+			     op->attempts);
+		return (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
+			 -EAGAIN :
+			 -EIO;
+	}
+	/* must have timed out, then... */
+	gossip_debug(GOSSIP_WAIT_DEBUG,
+		     "%s: operation timed out, tag %llu, %p, %d)\n",
+		     __func__,
+		     llu(op->tag),
+		     op,
+		     op->attempts);
+	return -ETIMEDOUT;
+}
diff --git a/fs/orangefs/xattr.c b/fs/orangefs/xattr.c
new file mode 100644
index 000000000..885fd3bd5
--- /dev/null
+++ b/fs/orangefs/xattr.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ * Copyright 2018 Omnibond Systems, L.L.C.
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS extended attribute operations.
+ */
+
+#include "protocol.h"
+#include "orangefs-kernel.h"
+#include "orangefs-bufmap.h"
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+#include <linux/hashtable.h>
+
+#define SYSTEM_ORANGEFS_KEY "system.pvfs2."
+#define SYSTEM_ORANGEFS_KEY_LEN 13
+
+/*
+ * this function returns
+ *   0 if the key corresponding to name is not meant to be printed as part
+ *     of a listxattr.
+ *   1 if the key corresponding to name is meant to be returned as part of
+ *     a listxattr.
+ * The ones that start SYSTEM_ORANGEFS_KEY are the ones to avoid printing.
+ */
+static int is_reserved_key(const char *key, size_t size)
+{
+
+	if (size < SYSTEM_ORANGEFS_KEY_LEN)
+		return 1;
+
+	return strncmp(key, SYSTEM_ORANGEFS_KEY, SYSTEM_ORANGEFS_KEY_LEN) ?  1 : 0;
+}
+
+static inline int convert_to_internal_xattr_flags(int setxattr_flags)
+{
+	int internal_flag = 0;
+
+	if (setxattr_flags & XATTR_REPLACE) {
+		/* Attribute must exist! */
+		internal_flag = ORANGEFS_XATTR_REPLACE;
+	} else if (setxattr_flags & XATTR_CREATE) {
+		/* Attribute must not exist */
+		internal_flag = ORANGEFS_XATTR_CREATE;
+	}
+	return internal_flag;
+}
+
+static unsigned int xattr_key(const char *key)
+{
+	unsigned int i = 0;
+	if (!key)
+		return 0;
+	while (*key)
+		i += *key++;
+	return i % 16;
+}
+
+static struct orangefs_cached_xattr *find_cached_xattr(struct inode *inode,
+    const char *key)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_cached_xattr *cx;
+	struct hlist_head *h;
+	struct hlist_node *tmp;
+	h = &orangefs_inode->xattr_cache[xattr_key(key)];
+	if (hlist_empty(h))
+		return NULL;
+	hlist_for_each_entry_safe(cx, tmp, h, node) {
+		if (!strcmp(cx->key, key))
+			return cx;
+	}
+	return NULL;
+}
+
+/*
+ * Tries to get a specified key's attributes of a given
+ * file into a user-specified buffer. Note that the getxattr
+ * interface allows for the users to probe the size of an
+ * extended attribute by passing in a value of 0 to size.
+ * Thus our return value is always the size of the attribute
+ * unless the key does not exist for the file and/or if
+ * there were errors in fetching the attribute value.
+ */
+ssize_t orangefs_inode_getxattr(struct inode *inode, const char *name,
+				void *buffer, size_t size)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op = NULL;
+	struct orangefs_cached_xattr *cx;
+	ssize_t ret = -ENOMEM;
+	ssize_t length = 0;
+	int fsuid;
+	int fsgid;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "%s: name %s, buffer_size %zd\n",
+		     __func__, name, size);
+
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
+		return -EINVAL;
+
+	fsuid = from_kuid(&init_user_ns, current_fsuid());
+	fsgid = from_kgid(&init_user_ns, current_fsgid());
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "getxattr on inode %pU, name %s "
+		     "(uid %o, gid %o)\n",
+		     get_khandle_from_ino(inode),
+		     name,
+		     fsuid,
+		     fsgid);
+
+	down_read(&orangefs_inode->xattr_sem);
+
+	cx = find_cached_xattr(inode, name);
+	if (cx && time_before(jiffies, cx->timeout)) {
+		if (cx->length == -1) {
+			ret = -ENODATA;
+			goto out_unlock;
+		} else {
+			if (size == 0) {
+				ret = cx->length;
+				goto out_unlock;
+			}
+			if (cx->length > size) {
+				ret = -ERANGE;
+				goto out_unlock;
+			}
+			memcpy(buffer, cx->val, cx->length);
+			memset(buffer + cx->length, 0, size - cx->length);
+			ret = cx->length;
+			goto out_unlock;
+		}
+	}
+
+	new_op = op_alloc(ORANGEFS_VFS_OP_GETXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	new_op->upcall.req.getxattr.refn = orangefs_inode->refn;
+	strscpy(new_op->upcall.req.getxattr.key, name);
+
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated textual
+	 * strings, I am going to explicitly pass the length just in case
+	 * we change this later on...
+	 */
+	new_op->upcall.req.getxattr.key_sz = strlen(name) + 1;
+
+	ret = service_operation(new_op, "orangefs_inode_getxattr",
+				get_interruptible_flag(inode));
+	if (ret != 0) {
+		if (ret == -ENOENT) {
+			ret = -ENODATA;
+			gossip_debug(GOSSIP_XATTR_DEBUG,
+				     "orangefs_inode_getxattr: inode %pU key %s"
+				     " does not exist!\n",
+				     get_khandle_from_ino(inode),
+				     (char *)new_op->upcall.req.getxattr.key);
+			cx = kmalloc_obj(*cx);
+			if (cx) {
+				strscpy(cx->key, name);
+				cx->length = -1;
+				cx->timeout = jiffies +
+				    orangefs_getattr_timeout_msecs*HZ/1000;
+				hlist_add_head( &cx->node,
+                                   &orangefs_inode->xattr_cache[xattr_key(cx->key)]);
+			}
+		}
+		goto out_release_op;
+	}
+
+	/*
+	 * Length returned includes null terminator.
+	 */
+	length = new_op->downcall.resp.getxattr.val_sz;
+	if (length < 0 || length > ORANGEFS_MAX_XATTR_VALUELEN) {
+		ret = -EIO;
+		goto out_release_op;
+	}
+
+	/*
+	 * Just return the length of the queried attribute.
+	 */
+	if (size == 0) {
+		ret = length;
+		goto out_release_op;
+	}
+
+	/*
+	 * Check to see if key length is > provided buffer size.
+	 */
+	if (length > size) {
+		ret = -ERANGE;
+		goto out_release_op;
+	}
+
+	memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
+	memset(buffer + length, 0, size - length);
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+	     "orangefs_inode_getxattr: inode %pU "
+	     "key %s key_sz %d, val_len %d\n",
+	     get_khandle_from_ino(inode),
+	     (char *)new_op->
+		upcall.req.getxattr.key,
+		     (int)new_op->
+		upcall.req.getxattr.key_sz,
+	     (int)ret);
+
+	ret = length;
+
+	if (cx) {
+		strscpy(cx->key, name);
+		memcpy(cx->val, buffer, length);
+		cx->length = length;
+		cx->timeout = jiffies + HZ;
+	} else {
+		cx = kmalloc_obj(*cx);
+		if (cx) {
+			strscpy(cx->key, name);
+			memcpy(cx->val, buffer, length);
+			cx->length = length;
+			cx->timeout = jiffies + HZ;
+			hlist_add_head(&cx->node,
+				&orangefs_inode->xattr_cache[xattr_key(cx->key)]);
+		}
+	}
+
+out_release_op:
+	op_release(new_op);
+out_unlock:
+	up_read(&orangefs_inode->xattr_sem);
+	return ret;
+}
+
+static int orangefs_inode_removexattr(struct inode *inode, const char *name,
+				      int flags)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op = NULL;
+	struct orangefs_cached_xattr *cx;
+	struct hlist_head *h;
+	struct hlist_node *tmp;
+	int ret = -ENOMEM;
+
+	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
+		return -EINVAL;
+
+	down_write(&orangefs_inode->xattr_sem);
+	new_op = op_alloc(ORANGEFS_VFS_OP_REMOVEXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	new_op->upcall.req.removexattr.refn = orangefs_inode->refn;
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated
+	 * textual strings, I am going to explicitly pass the
+	 * length just in case we change this later on...
+	 */
+	strscpy(new_op->upcall.req.removexattr.key, name);
+	new_op->upcall.req.removexattr.key_sz = strlen(name) + 1;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "orangefs_inode_removexattr: key %s, key_sz %d\n",
+		     (char *)new_op->upcall.req.removexattr.key,
+		     (int)new_op->upcall.req.removexattr.key_sz);
+
+	ret = service_operation(new_op,
+				"orangefs_inode_removexattr",
+				get_interruptible_flag(inode));
+	if (ret == -ENOENT) {
+		/*
+		 * Request to replace a non-existent attribute is an error.
+		 */
+		if (flags & XATTR_REPLACE)
+			ret = -ENODATA;
+		else
+			ret = 0;
+	}
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "orangefs_inode_removexattr: returning %d\n", ret);
+
+	op_release(new_op);
+
+	h = &orangefs_inode->xattr_cache[xattr_key(name)];
+	hlist_for_each_entry_safe(cx, tmp, h, node) {
+		if (!strcmp(cx->key, name)) {
+			hlist_del(&cx->node);
+			kfree(cx);
+			break;
+		}
+	}
+
+out_unlock:
+	up_write(&orangefs_inode->xattr_sem);
+	return ret;
+}
+
+/*
+ * Tries to set an attribute for a given key on a file.
+ *
+ * Returns a -ve number on error and 0 on success.  Key is text, but value
+ * can be binary!
+ */
+int orangefs_inode_setxattr(struct inode *inode, const char *name,
+			    const void *value, size_t size, int flags)
+{
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	int internal_flag = 0;
+	struct orangefs_cached_xattr *cx;
+	struct hlist_head *h;
+	struct hlist_node *tmp;
+	int ret = -ENOMEM;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "%s: name %s, buffer_size %zd\n",
+		     __func__, name, size);
+
+	if (size > ORANGEFS_MAX_XATTR_VALUELEN)
+		return -EINVAL;
+	if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
+		return -EINVAL;
+
+	internal_flag = convert_to_internal_xattr_flags(flags);
+
+	/* This is equivalent to a removexattr */
+	if (size == 0 && !value) {
+		gossip_debug(GOSSIP_XATTR_DEBUG,
+			     "removing xattr (%s)\n",
+			     name);
+		return orangefs_inode_removexattr(inode, name, flags);
+	}
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "setxattr on inode %pU, name %s\n",
+		     get_khandle_from_ino(inode),
+		     name);
+
+	down_write(&orangefs_inode->xattr_sem);
+	new_op = op_alloc(ORANGEFS_VFS_OP_SETXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+
+	new_op->upcall.req.setxattr.refn = orangefs_inode->refn;
+	new_op->upcall.req.setxattr.flags = internal_flag;
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated textual
+	 * strings, I am going to explicitly pass the length just in
+	 * case we change this later on...
+	 */
+	strscpy(new_op->upcall.req.setxattr.keyval.key, name);
+	new_op->upcall.req.setxattr.keyval.key_sz = strlen(name) + 1;
+	memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
+	new_op->upcall.req.setxattr.keyval.val_sz = size;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "orangefs_inode_setxattr: key %s, key_sz %d "
+		     " value size %zd\n",
+		     (char *)new_op->upcall.req.setxattr.keyval.key,
+		     (int)new_op->upcall.req.setxattr.keyval.key_sz,
+		     size);
+
+	ret = service_operation(new_op,
+				"orangefs_inode_setxattr",
+				get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "orangefs_inode_setxattr: returning %d\n",
+		     ret);
+
+	/* when request is serviced properly, free req op struct */
+	op_release(new_op);
+
+	h = &orangefs_inode->xattr_cache[xattr_key(name)];
+	hlist_for_each_entry_safe(cx, tmp, h, node) {
+		if (!strcmp(cx->key, name)) {
+			hlist_del(&cx->node);
+			kfree(cx);
+			break;
+		}
+	}
+
+out_unlock:
+	up_write(&orangefs_inode->xattr_sem);
+	return ret;
+}
+
+/*
+ * Tries to get a specified object's keys into a user-specified buffer of a
+ * given size.  Note that like the previous instances of xattr routines, this
+ * also allows you to pass in a NULL pointer and 0 size to probe the size for
+ * subsequent memory allocations. Thus our return value is always the size of
+ * all the keys unless there were errors in fetching the keys!
+ */
+ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+	struct inode *inode = dentry->d_inode;
+	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
+	struct orangefs_kernel_op_s *new_op;
+	__u64 token = ORANGEFS_ITERATE_START;
+	ssize_t ret = -ENOMEM;
+	ssize_t total = 0;
+	int count_keys = 0;
+	int key_size;
+	int i = 0;
+	int returned_count = 0;
+
+	if (size > 0 && !buffer) {
+		gossip_err("%s: bogus NULL pointers\n", __func__);
+		return -EINVAL;
+	}
+
+	down_read(&orangefs_inode->xattr_sem);
+	new_op = op_alloc(ORANGEFS_VFS_OP_LISTXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	if (buffer && size > 0)
+		memset(buffer, 0, size);
+
+try_again:
+	key_size = 0;
+	new_op->upcall.req.listxattr.refn = orangefs_inode->refn;
+	new_op->upcall.req.listxattr.token = token;
+	new_op->upcall.req.listxattr.requested_count =
+	    (size == 0) ? 0 : ORANGEFS_MAX_XATTR_LISTLEN;
+	ret = service_operation(new_op, __func__,
+				get_interruptible_flag(inode));
+	if (ret != 0)
+		goto done;
+
+	if (size == 0) {
+		/*
+		 * This is a bit of a big upper limit, but I did not want to
+		 * spend too much time getting this correct, since users end
+		 * up allocating memory rather than us...
+		 */
+		total = new_op->downcall.resp.listxattr.returned_count *
+			ORANGEFS_MAX_XATTR_NAMELEN;
+		goto done;
+	}
+
+	returned_count = new_op->downcall.resp.listxattr.returned_count;
+	if (returned_count < 0 ||
+	    returned_count > ORANGEFS_MAX_XATTR_LISTLEN) {
+		gossip_err("%s: impossible value for returned_count:%d:\n",
+		__func__,
+		returned_count);
+		ret = -EIO;
+		goto done;
+	}
+
+	/*
+	 * Check to see how much can be fit in the buffer. Fit only whole keys.
+	 */
+	for (i = 0; i < returned_count; i++) {
+		if (new_op->downcall.resp.listxattr.lengths[i] < 0 ||
+		    new_op->downcall.resp.listxattr.lengths[i] >
+		    ORANGEFS_MAX_XATTR_NAMELEN) {
+			gossip_err("%s: impossible value for lengths[%d]\n",
+			    __func__,
+			    new_op->downcall.resp.listxattr.lengths[i]);
+			ret = -EIO;
+			goto done;
+		}
+		if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
+			goto done;
+
+		/*
+		 * Since many dumb programs try to setxattr() on our reserved
+		 * xattrs this is a feeble attempt at defeating those by not
+		 * listing them in the output of listxattr.. sigh
+		 */
+		if (is_reserved_key(new_op->downcall.resp.listxattr.key +
+				    key_size,
+				    new_op->downcall.resp.
+					listxattr.lengths[i])) {
+			gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
+					i, new_op->downcall.resp.listxattr.key +
+						key_size);
+			memcpy(buffer + total,
+				new_op->downcall.resp.listxattr.key + key_size,
+				new_op->downcall.resp.listxattr.lengths[i]);
+			total += new_op->downcall.resp.listxattr.lengths[i];
+			count_keys++;
+		} else {
+			gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
+					i, new_op->downcall.resp.listxattr.key +
+						key_size);
+		}
+		key_size += new_op->downcall.resp.listxattr.lengths[i];
+	}
+
+	/*
+	 * Since the buffer was large enough, we might have to continue
+	 * fetching more keys!
+	 */
+	token = new_op->downcall.resp.listxattr.token;
+	if (token != ORANGEFS_ITERATE_END)
+		goto try_again;
+
+done:
+	gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
+		     " [size of buffer %ld] (filled in %d keys)\n",
+		     __func__,
+		     ret ? (int)ret : (int)total,
+		     (long)size,
+		     count_keys);
+	op_release(new_op);
+	if (ret == 0)
+		ret = total;
+out_unlock:
+	up_read(&orangefs_inode->xattr_sem);
+	return ret;
+}
+
+static int orangefs_xattr_set_default(const struct xattr_handler *handler,
+				      struct mnt_idmap *idmap,
+				      struct dentry *unused,
+				      struct inode *inode,
+				      const char *name,
+				      const void *buffer,
+				      size_t size,
+				      int flags)
+{
+	return orangefs_inode_setxattr(inode, name, buffer, size, flags);
+}
+
+static int orangefs_xattr_get_default(const struct xattr_handler *handler,
+				      struct dentry *unused,
+				      struct inode *inode,
+				      const char *name,
+				      void *buffer,
+				      size_t size)
+{
+	return orangefs_inode_getxattr(inode, name, buffer, size);
+
+}
+
+static const struct xattr_handler orangefs_xattr_default_handler = {
+	.prefix = "",  /* match any name => handlers called with full name */
+	.get = orangefs_xattr_get_default,
+	.set = orangefs_xattr_set_default,
+};
+
+const struct xattr_handler * const orangefs_xattr_handlers[] = {
+	&orangefs_xattr_default_handler,
+	NULL
+};