Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1701 insertions, 0 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
new file mode 100644
index 000000000..a40f53087
--- /dev/null
+++ b/fs/ext2/super.c
@@ -0,0 +1,1701 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/ext2/super.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/random.h>
+#include <linux/buffer_head.h>
+#include <linux/exportfs.h>
+#include <linux/vfs.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/log2.h>
+#include <linux/quotaops.h>
+#include <linux/uaccess.h>
+#include <linux/iversion.h>
+#include "ext2.h"
+#include "xattr.h"
+#include "acl.h"
+
+static void ext2_write_super(struct super_block *sb);
+static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
+static int ext2_sync_fs(struct super_block *sb, int wait);
+static int ext2_freeze(struct super_block *sb);
+static int ext2_unfreeze(struct super_block *sb);
+
+void ext2_error(struct super_block *sb, const char *function,
+		const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+	struct ext2_super_block *es = sbi->s_es;
+
+	if (!sb_rdonly(sb)) {
+		spin_lock(&sbi->s_lock);
+		sbi->s_mount_state |= EXT2_ERROR_FS;
+		es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
+		spin_unlock(&sbi->s_lock);
+		ext2_sync_super(sb, es, 1);
+	}
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
+	       sb->s_id, function, &vaf);
+
+	va_end(args);
+
+	if (test_opt(sb, ERRORS_PANIC))
+		panic("EXT2-fs: panic from previous error\n");
+	if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {
+		ext2_msg(sb, KERN_CRIT,
+			     "error: remounting filesystem read-only");
+		sb->s_flags |= SB_RDONLY;
+	}
+}
+
+static void ext2_msg_fc(struct fs_context *fc, const char *prefix,
+			const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+	const char *s_id;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		s_id = fc->root->d_sb->s_id;
+	} else {
+		/* get last path component of source */
+		s_id = strrchr(fc->source, '/');
+		if (s_id)
+			s_id++;
+		else
+			s_id = fc->source;
+	}
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk("%sEXT2-fs (%s): %pV\n", prefix, s_id, &vaf);
+
+	va_end(args);
+}
+
+void ext2_msg(struct super_block *sb, const char *prefix,
+		const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
+
+	va_end(args);
+}
+
+/*
+ * This must be called with sbi->s_lock held.
+ */
+void ext2_update_dynamic_rev(struct super_block *sb)
+{
+	struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+
+	if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
+		return;
+
+	ext2_msg(sb, KERN_WARNING,
+		     "warning: updating to rev %d because of "
+		     "new feature flag, running e2fsck is recommended",
+		     EXT2_DYNAMIC_REV);
+
+	es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
+	es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
+	es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
+	/* leave es->s_feature_*compat flags alone */
+	/* es->s_uuid will be set by e2fsck if empty */
+
+	/*
+	 * The rest of the superblock fields should be zero, and if not it
+	 * means they are likely already in use, so leave them alone.  We
+	 * can leave it up to e2fsck to clean up any inconsistencies there.
+	 */
+}
+
+#ifdef CONFIG_QUOTA
+static int ext2_quota_off(struct super_block *sb, int type);
+
+static void ext2_quota_off_umount(struct super_block *sb)
+{
+	int type;
+
+	for (type = 0; type < MAXQUOTAS; type++)
+		ext2_quota_off(sb, type);
+}
+#else
+static inline void ext2_quota_off_umount(struct super_block *sb)
+{
+}
+#endif
+
+static void ext2_put_super (struct super_block * sb)
+{
+	int db_count;
+	int i;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+	ext2_quota_off_umount(sb);
+
+	ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
+	sbi->s_ea_block_cache = NULL;
+
+	if (!sb_rdonly(sb)) {
+		struct ext2_super_block *es = sbi->s_es;
+
+		spin_lock(&sbi->s_lock);
+		es->s_state = cpu_to_le16(sbi->s_mount_state);
+		spin_unlock(&sbi->s_lock);
+		ext2_sync_super(sb, es, 1);
+	}
+	db_count = sbi->s_gdb_count;
+	for (i = 0; i < db_count; i++)
+		brelse(sbi->s_group_desc[i]);
+	kvfree(sbi->s_group_desc);
+	kfree(sbi->s_debts);
+	percpu_counter_destroy(&sbi->s_freeblocks_counter);
+	percpu_counter_destroy(&sbi->s_freeinodes_counter);
+	percpu_counter_destroy(&sbi->s_dirs_counter);
+	brelse (sbi->s_sbh);
+	sb->s_fs_info = NULL;
+	kfree(sbi->s_blockgroup_lock);
+	kfree(sbi);
+}
+
+static struct kmem_cache * ext2_inode_cachep;
+
+static struct inode *ext2_alloc_inode(struct super_block *sb)
+{
+	struct ext2_inode_info *ei;
+	ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	ei->i_block_alloc_info = NULL;
+	inode_set_iversion(&ei->vfs_inode, 1);
+#ifdef CONFIG_QUOTA
+	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
+#endif
+	mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data);
+
+	return &ei->vfs_inode;
+}
+
+static void ext2_free_in_core_inode(struct inode *inode)
+{
+	kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
+}
+
+static void init_once(void *foo)
+{
+	struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
+
+	rwlock_init(&ei->i_meta_lock);
+#ifdef CONFIG_EXT2_FS_XATTR
+	init_rwsem(&ei->xattr_sem);
+#endif
+	mutex_init(&ei->truncate_mutex);
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
+				sizeof(struct ext2_inode_info), 0,
+				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
+				offsetof(struct ext2_inode_info, i_data),
+				sizeof_field(struct ext2_inode_info, i_data),
+				init_once);
+	if (ext2_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(ext2_inode_cachep);
+}
+
+static int ext2_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct super_block *sb = root->d_sb;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+	struct ext2_super_block *es = sbi->s_es;
+	unsigned long def_mount_opts;
+
+	spin_lock(&sbi->s_lock);
+	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+
+	if (sbi->s_sb_block != 1)
+		seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
+	if (test_opt(sb, MINIX_DF))
+		seq_puts(seq, ",minixdf");
+	if (test_opt(sb, GRPID))
+		seq_puts(seq, ",grpid");
+	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
+		seq_puts(seq, ",nogrpid");
+	if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
+	    le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
+		seq_printf(seq, ",resuid=%u",
+				from_kuid_munged(&init_user_ns, sbi->s_resuid));
+	}
+	if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
+	    le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
+		seq_printf(seq, ",resgid=%u",
+				from_kgid_munged(&init_user_ns, sbi->s_resgid));
+	}
+	if (test_opt(sb, ERRORS_RO)) {
+		int def_errors = le16_to_cpu(es->s_errors);
+
+		if (def_errors == EXT2_ERRORS_PANIC ||
+		    def_errors == EXT2_ERRORS_CONTINUE) {
+			seq_puts(seq, ",errors=remount-ro");
+		}
+	}
+	if (test_opt(sb, ERRORS_CONT))
+		seq_puts(seq, ",errors=continue");
+	if (test_opt(sb, ERRORS_PANIC))
+		seq_puts(seq, ",errors=panic");
+	if (test_opt(sb, NO_UID32))
+		seq_puts(seq, ",nouid32");
+	if (test_opt(sb, DEBUG))
+		seq_puts(seq, ",debug");
+	if (test_opt(sb, OLDALLOC))
+		seq_puts(seq, ",oldalloc");
+
+#ifdef CONFIG_EXT2_FS_XATTR
+	if (test_opt(sb, XATTR_USER))
+		seq_puts(seq, ",user_xattr");
+	if (!test_opt(sb, XATTR_USER) &&
+	    (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
+		seq_puts(seq, ",nouser_xattr");
+	}
+#endif
+
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+	if (test_opt(sb, POSIX_ACL))
+		seq_puts(seq, ",acl");
+	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
+		seq_puts(seq, ",noacl");
+#endif
+
+	if (test_opt(sb, USRQUOTA))
+		seq_puts(seq, ",usrquota");
+
+	if (test_opt(sb, GRPQUOTA))
+		seq_puts(seq, ",grpquota");
+
+
+
+	if (!test_opt(sb, RESERVATION))
+		seq_puts(seq, ",noreservation");
+
+	spin_unlock(&sbi->s_lock);
+	return 0;
+}
+
+#ifdef CONFIG_QUOTA
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
+static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
+static int ext2_quota_on(struct super_block *sb, int type, int format_id,
+			 const struct path *path);
+static struct dquot __rcu **ext2_get_dquots(struct inode *inode)
+{
+	return EXT2_I(inode)->i_dquot;
+}
+
+static const struct quotactl_ops ext2_quotactl_ops = {
+	.quota_on	= ext2_quota_on,
+	.quota_off	= ext2_quota_off,
+	.quota_sync	= dquot_quota_sync,
+	.get_state	= dquot_get_state,
+	.set_info	= dquot_set_dqinfo,
+	.get_dqblk	= dquot_get_dqblk,
+	.set_dqblk	= dquot_set_dqblk,
+	.get_nextdqblk	= dquot_get_next_dqblk,
+};
+#endif
+
+static const struct super_operations ext2_sops = {
+	.alloc_inode	= ext2_alloc_inode,
+	.free_inode	= ext2_free_in_core_inode,
+	.write_inode	= ext2_write_inode,
+	.sync_inode_metadata = ext2_sync_inode_metadata,
+	.evict_inode	= ext2_evict_inode,
+	.put_super	= ext2_put_super,
+	.sync_fs	= ext2_sync_fs,
+	.freeze_fs	= ext2_freeze,
+	.unfreeze_fs	= ext2_unfreeze,
+	.statfs		= ext2_statfs,
+	.show_options	= ext2_show_options,
+#ifdef CONFIG_QUOTA
+	.quota_read	= ext2_quota_read,
+	.quota_write	= ext2_quota_write,
+	.get_dquots	= ext2_get_dquots,
+#endif
+};
+
+static struct inode *ext2_nfs_get_inode(struct super_block *sb,
+		u64 ino, u32 generation)
+{
+	struct inode *inode;
+
+	if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
+		return ERR_PTR(-ESTALE);
+	if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+		return ERR_PTR(-ESTALE);
+
+	/*
+	 * ext2_iget isn't quite right if the inode is currently unallocated!
+	 * However ext2_iget currently does appropriate checks to handle stale
+	 * inodes so everything is OK.
+	 */
+	inode = ext2_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (generation && inode->i_generation != generation) {
+		/* we didn't find the right inode.. */
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return inode;
+}
+
+static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    ext2_nfs_get_inode);
+}
+
+static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    ext2_nfs_get_inode);
+}
+
+static const struct export_operations ext2_export_ops = {
+	.encode_fh = generic_encode_ino32_fh,
+	.fh_to_dentry = ext2_fh_to_dentry,
+	.fh_to_parent = ext2_fh_to_parent,
+	.get_parent = ext2_get_parent,
+};
+
+enum {
+	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid, Opt_resgid, Opt_resuid,
+	Opt_sb, Opt_errors, Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
+	Opt_nobh, Opt_user_xattr, Opt_acl, Opt_xip, Opt_dax, Opt_ignore,
+	Opt_quota, Opt_usrquota, Opt_grpquota, Opt_reservation,
+};
+
+static const struct constant_table ext2_param_errors[] = {
+	{"continue",	EXT2_MOUNT_ERRORS_CONT},
+	{"panic",	EXT2_MOUNT_ERRORS_PANIC},
+	{"remount-ro",	EXT2_MOUNT_ERRORS_RO},
+	{}
+};
+
+static const struct fs_parameter_spec ext2_param_spec[] = {
+	fsparam_flag	("bsddf", Opt_bsd_df),
+	fsparam_flag	("minixdf", Opt_minix_df),
+	fsparam_flag	("grpid", Opt_grpid),
+	fsparam_flag	("bsdgroups", Opt_grpid),
+	fsparam_flag	("nogrpid", Opt_nogrpid),
+	fsparam_flag	("sysvgroups", Opt_nogrpid),
+	fsparam_gid	("resgid", Opt_resgid),
+	fsparam_uid	("resuid", Opt_resuid),
+	fsparam_u32	("sb", Opt_sb),
+	fsparam_enum	("errors", Opt_errors, ext2_param_errors),
+	fsparam_flag	("nouid32", Opt_nouid32),
+	fsparam_flag	("debug", Opt_debug),
+	fsparam_flag	("oldalloc", Opt_oldalloc),
+	fsparam_flag	("orlov", Opt_orlov),
+	fsparam_flag	("nobh", Opt_nobh),
+	fsparam_flag_no	("user_xattr", Opt_user_xattr),
+	fsparam_flag_no	("acl", Opt_acl),
+	fsparam_flag	("xip", Opt_xip),
+	fsparam_flag	("dax", Opt_dax),
+	fsparam_flag	("grpquota", Opt_grpquota),
+	fsparam_flag	("noquota", Opt_ignore),
+	fsparam_flag	("quota", Opt_quota),
+	fsparam_flag	("usrquota", Opt_usrquota),
+	fsparam_flag_no	("reservation", Opt_reservation),
+	{}
+};
+
+#define EXT2_SPEC_s_resuid                      (1 << 0)
+#define EXT2_SPEC_s_resgid                      (1 << 1)
+
+struct ext2_fs_context {
+	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
+	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
+	unsigned int	vals_s_mount_opt;
+	unsigned int	mask_s_mount_opt;
+	kuid_t		s_resuid;
+	kgid_t		s_resgid;
+	unsigned long	s_sb_block;
+	unsigned int	spec;
+
+};
+
+static inline void ctx_set_mount_opt(struct ext2_fs_context *ctx,
+				  unsigned long flag)
+{
+	ctx->mask_s_mount_opt |= flag;
+	ctx->vals_s_mount_opt |= flag;
+}
+
+static inline void ctx_clear_mount_opt(struct ext2_fs_context *ctx,
+				    unsigned long flag)
+{
+	ctx->mask_s_mount_opt |= flag;
+	ctx->vals_s_mount_opt &= ~flag;
+}
+
+static inline unsigned long
+ctx_test_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
+{
+	return (ctx->vals_s_mount_opt & flag);
+}
+
+static inline bool
+ctx_parsed_mount_opt(struct ext2_fs_context *ctx, unsigned long flag)
+{
+	return (ctx->mask_s_mount_opt & flag);
+}
+
+static void ext2_free_fc(struct fs_context *fc)
+{
+	kfree(fc->fs_private);
+}
+
+static int ext2_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	int opt;
+	struct fs_parse_result result;
+
+	opt = fs_parse(fc, ext2_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_bsd_df:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
+		break;
+	case Opt_minix_df:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_MINIX_DF);
+		break;
+	case Opt_grpid:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPID);
+		break;
+	case Opt_nogrpid:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_GRPID);
+		break;
+	case Opt_resuid:
+		ctx->s_resuid = result.uid;
+		ctx->spec |= EXT2_SPEC_s_resuid;
+		break;
+	case Opt_resgid:
+		ctx->s_resgid = result.gid;
+		ctx->spec |= EXT2_SPEC_s_resgid;
+		break;
+	case Opt_sb:
+		/* Note that this is silently ignored on remount */
+		ctx->s_sb_block = result.uint_32;
+		break;
+	case Opt_errors:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK);
+		ctx_set_mount_opt(ctx, result.uint_32);
+		break;
+	case Opt_nouid32:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_NO_UID32);
+		break;
+	case Opt_debug:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_DEBUG);
+		break;
+	case Opt_oldalloc:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
+		break;
+	case Opt_orlov:
+		ctx_clear_mount_opt(ctx, EXT2_MOUNT_OLDALLOC);
+		break;
+	case Opt_nobh:
+		ext2_msg_fc(fc, KERN_INFO, "nobh option not supported\n");
+		break;
+#ifdef CONFIG_EXT2_FS_XATTR
+	case Opt_user_xattr:
+		if (!result.negated)
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
+		else
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_XATTR_USER);
+		break;
+#else
+	case Opt_user_xattr:
+		ext2_msg_fc(fc, KERN_INFO, "(no)user_xattr options not supported");
+		break;
+#endif
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+	case Opt_acl:
+		if (!result.negated)
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
+		else
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL);
+		break;
+#else
+	case Opt_acl:
+		ext2_msg_fc(fc, KERN_INFO, "(no)acl options not supported");
+		break;
+#endif
+	case Opt_xip:
+		ext2_msg_fc(fc, KERN_WARNING, "DAX support has been removed. xip option ignored.");
+		break;
+	case Opt_dax:
+		ext2_msg_fc(fc, KERN_WARNING, "DAX support has been removed. dax option ignored.");
+		break;
+
+#if defined(CONFIG_QUOTA)
+	case Opt_quota:
+	case Opt_usrquota:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_USRQUOTA);
+		break;
+
+	case Opt_grpquota:
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_GRPQUOTA);
+		break;
+#else
+	case Opt_quota:
+	case Opt_usrquota:
+	case Opt_grpquota:
+		ext2_msg_fc(fc, KERN_INFO, "quota operations not supported");
+		break;
+#endif
+	case Opt_reservation:
+		if (!result.negated) {
+			ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+			ext2_msg_fc(fc, KERN_INFO, "reservations ON");
+		} else {
+			ctx_clear_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+			ext2_msg_fc(fc, KERN_INFO, "reservations OFF");
+		}
+		break;
+	case Opt_ignore:
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int ext2_setup_super (struct super_block * sb,
+			      struct ext2_super_block * es,
+			      int read_only)
+{
+	int res = 0;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+	if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
+		ext2_msg(sb, KERN_ERR,
+			"error: revision level too high, "
+			"forcing read-only mode");
+		res = SB_RDONLY;
+	}
+	if (read_only)
+		return res;
+	if (!(sbi->s_mount_state & EXT2_VALID_FS))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: mounting unchecked fs, "
+			"running e2fsck is recommended");
+	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: mounting fs with errors, "
+			"running e2fsck is recommended");
+	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
+		 le16_to_cpu(es->s_mnt_count) >=
+		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: maximal mount count reached, "
+			"running e2fsck is recommended");
+	else if (le32_to_cpu(es->s_checkinterval) &&
+		(le32_to_cpu(es->s_lastcheck) +
+			le32_to_cpu(es->s_checkinterval) <=
+			ktime_get_real_seconds()))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: checktime reached, "
+			"running e2fsck is recommended");
+	if (!le16_to_cpu(es->s_max_mnt_count))
+		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
+	le16_add_cpu(&es->s_mnt_count, 1);
+	if (test_opt (sb, DEBUG))
+		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "
+			"bpg=%lu, ipg=%lu, mo=%04lx]",
+			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
+			sbi->s_groups_count,
+			EXT2_BLOCKS_PER_GROUP(sb),
+			EXT2_INODES_PER_GROUP(sb),
+			sbi->s_mount_opt);
+	return res;
+}
+
+static int ext2_check_descriptors(struct super_block *sb)
+{
+	int i;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+	ext2_debug ("Checking group descriptors");
+
+	for (i = 0; i < sbi->s_groups_count; i++) {
+		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
+		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
+		ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);
+
+		if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
+		{
+			ext2_error (sb, "ext2_check_descriptors",
+				    "Block bitmap for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
+			return 0;
+		}
+		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
+		{
+			ext2_error (sb, "ext2_check_descriptors",
+				    "Inode bitmap for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
+			return 0;
+		}
+		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
+		    last_block)
+		{
+			ext2_error (sb, "ext2_check_descriptors",
+				    "Inode table for group %d"
+				    " not in group (block %lu)!",
+				    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/*
+ * Maximal file size.  There is a direct, and {,double-,triple-}indirect
+ * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
+ * We need to be 1 filesystem block less than the 2^32 sector limit.
+ */
+static loff_t ext2_max_size(int bits)
+{
+	loff_t res = EXT2_NDIR_BLOCKS;
+	int meta_blocks;
+	unsigned int upper_limit;
+	unsigned int ppb = 1 << (bits-2);
+
+	/* This is calculated to be the largest file size for a
+	 * dense, file such that the total number of
+	 * sectors in the file, including data and all indirect blocks,
+	 * does not exceed 2^32 -1
+	 * __u32 i_blocks representing the total number of
+	 * 512 bytes blocks of the file
+	 */
+	upper_limit = (1LL << 32) - 1;
+
+	/* total blocks in file system block size */
+	upper_limit >>= (bits - 9);
+
+	/* Compute how many blocks we can address by block tree */
+	res += 1LL << (bits-2);
+	res += 1LL << (2*(bits-2));
+	res += 1LL << (3*(bits-2));
+	/* Compute how many metadata blocks are needed */
+	meta_blocks = 1;
+	meta_blocks += 1 + ppb;
+	meta_blocks += 1 + ppb + ppb * ppb;
+	/* Does block tree limit file size? */
+	if (res + meta_blocks <= upper_limit)
+		goto check_lfs;
+
+	res = upper_limit;
+	/* How many metadata blocks are needed for addressing upper_limit? */
+	upper_limit -= EXT2_NDIR_BLOCKS;
+	/* indirect blocks */
+	meta_blocks = 1;
+	upper_limit -= ppb;
+	/* double indirect blocks */
+	if (upper_limit < ppb * ppb) {
+		meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb);
+		res -= meta_blocks;
+		goto check_lfs;
+	}
+	meta_blocks += 1 + ppb;
+	upper_limit -= ppb * ppb;
+	/* tripple indirect blocks for the rest */
+	meta_blocks += 1 + DIV_ROUND_UP(upper_limit, ppb) +
+		DIV_ROUND_UP(upper_limit, ppb*ppb);
+	res -= meta_blocks;
+check_lfs:
+	res <<= bits;
+	if (res > MAX_LFS_FILESIZE)
+		res = MAX_LFS_FILESIZE;
+
+	return res;
+}
+
+static unsigned long descriptor_loc(struct super_block *sb,
+				    unsigned long logic_sb_block,
+				    int nr)
+{
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+	unsigned long bg, first_meta_bg;
+	
+	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
+
+	if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
+	    nr < first_meta_bg)
+		return (logic_sb_block + nr + 1);
+	bg = sbi->s_desc_per_block * nr;
+
+	return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);
+}
+
+/*
+ * Set all mount options either from defaults on disk, or from parsed
+ * options. Parsed/specified options override on-disk defaults.
+ */
+static void ext2_set_options(struct fs_context *fc, struct ext2_sb_info *sbi)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	struct ext2_super_block *es = sbi->s_es;
+	unsigned long def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+
+	/* Copy parsed mount options to sbi */
+	sbi->s_mount_opt = ctx->vals_s_mount_opt;
+
+	/* Use in-superblock defaults only if not specified during parsing */
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_DEBUG) &&
+	    def_mount_opts & EXT2_DEFM_DEBUG)
+		set_opt(sbi->s_mount_opt, DEBUG);
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_GRPID) &&
+	    def_mount_opts & EXT2_DEFM_BSDGROUPS)
+		set_opt(sbi->s_mount_opt, GRPID);
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_NO_UID32) &&
+	    def_mount_opts & EXT2_DEFM_UID16)
+		set_opt(sbi->s_mount_opt, NO_UID32);
+
+#ifdef CONFIG_EXT2_FS_XATTR
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_XATTR_USER) &&
+	    def_mount_opts & EXT2_DEFM_XATTR_USER)
+		set_opt(sbi->s_mount_opt, XATTR_USER);
+#endif
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_POSIX_ACL) &&
+	    def_mount_opts & EXT2_DEFM_ACL)
+		set_opt(sbi->s_mount_opt, POSIX_ACL);
+#endif
+
+	if (!ctx_parsed_mount_opt(ctx, EXT2_MOUNT_ERRORS_MASK)) {
+		if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
+			set_opt(sbi->s_mount_opt, ERRORS_PANIC);
+		else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
+			set_opt(sbi->s_mount_opt, ERRORS_CONT);
+		else
+			set_opt(sbi->s_mount_opt, ERRORS_RO);
+	}
+
+	if (ctx->spec & EXT2_SPEC_s_resuid)
+		sbi->s_resuid = ctx->s_resuid;
+	else
+		sbi->s_resuid = make_kuid(&init_user_ns,
+					   le16_to_cpu(es->s_def_resuid));
+
+	if (ctx->spec & EXT2_SPEC_s_resgid)
+		sbi->s_resgid = ctx->s_resgid;
+	else
+		sbi->s_resgid = make_kgid(&init_user_ns,
+					   le16_to_cpu(es->s_def_resgid));
+}
+
+static int ext2_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	int silent = fc->sb_flags & SB_SILENT;
+	struct buffer_head * bh;
+	struct ext2_sb_info * sbi;
+	struct ext2_super_block * es;
+	struct inode *root;
+	unsigned long block;
+	unsigned long sb_block = ctx->s_sb_block;
+	unsigned long logic_sb_block;
+	unsigned long offset = 0;
+	long ret = -ENOMEM;
+	int blocksize = BLOCK_SIZE;
+	int db_count;
+	int i, j;
+	__le32 features;
+	int err;
+
+	sbi = kzalloc_obj(*sbi);
+	if (!sbi)
+		return -ENOMEM;
+
+	sbi->s_blockgroup_lock =
+		kzalloc_obj(struct blockgroup_lock);
+	if (!sbi->s_blockgroup_lock) {
+		kfree(sbi);
+		return -ENOMEM;
+	}
+	sb->s_fs_info = sbi;
+	sbi->s_sb_block = sb_block;
+
+	spin_lock_init(&sbi->s_lock);
+	ret = -EINVAL;
+
+	/*
+	 * See what the current blocksize for the device is, and
+	 * use that as the blocksize.  Otherwise (or if the blocksize
+	 * is smaller than the default) use the default.
+	 * This is important for devices that have a hardware
+	 * sectorsize that is larger than the default.
+	 */
+	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
+	if (!blocksize) {
+		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
+		goto failed_sbi;
+	}
+
+	/*
+	 * If the superblock doesn't start on a hardware sector boundary,
+	 * calculate the offset.  
+	 */
+	if (blocksize != BLOCK_SIZE) {
+		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+		offset = (sb_block*BLOCK_SIZE) % blocksize;
+	} else {
+		logic_sb_block = sb_block;
+	}
+
+	if (!(bh = sb_bread(sb, logic_sb_block))) {
+		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
+		goto failed_sbi;
+	}
+	/*
+	 * Note: s_es must be initialized as soon as possible because
+	 *       some ext2 macro-instructions depend on its value
+	 */
+	es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+	sbi->s_es = es;
+	sb->s_magic = le16_to_cpu(es->s_magic);
+
+	if (sb->s_magic != EXT2_SUPER_MAGIC)
+		goto cantfind_ext2;
+
+	ext2_set_options(fc, sbi);
+
+	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
+	sb->s_iflags |= SB_I_CGROUPWB;
+
+	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
+	    (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
+	     EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
+	     EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: feature flags set on rev 0 fs, "
+			"running e2fsck is recommended");
+	/*
+	 * Check feature flags regardless of the revision level, since we
+	 * previously didn't change the revision level when setting the flags,
+	 * so there is a chance incompat flags are set on a rev 0 filesystem.
+	 */
+	features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
+	if (features) {
+		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "
+		       "unsupported optional features (%x)",
+			le32_to_cpu(features));
+		goto failed_mount;
+	}
+	if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
+		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
+		       "unsupported optional features (%x)",
+		       le32_to_cpu(features));
+		goto failed_mount;
+	}
+
+	if (le32_to_cpu(es->s_log_block_size) >
+	    (EXT2_MAX_BLOCK_LOG_SIZE - BLOCK_SIZE_BITS)) {
+		ext2_msg(sb, KERN_ERR,
+			 "Invalid log block size: %u",
+			 le32_to_cpu(es->s_log_block_size));
+		goto failed_mount;
+	}
+	blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
+
+	/* If the blocksize doesn't match, re-read the thing.. */
+	if (sb->s_blocksize != blocksize) {
+		brelse(bh);
+
+		if (!sb_set_blocksize(sb, blocksize)) {
+			ext2_msg(sb, KERN_ERR,
+				"error: bad blocksize %d", blocksize);
+			goto failed_sbi;
+		}
+
+		logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
+		offset = (sb_block*BLOCK_SIZE) % blocksize;
+		bh = sb_bread(sb, logic_sb_block);
+		if(!bh) {
+			ext2_msg(sb, KERN_ERR, "error: couldn't read"
+				"superblock on 2nd try");
+			goto failed_sbi;
+		}
+		es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
+		sbi->s_es = es;
+		if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
+			ext2_msg(sb, KERN_ERR, "error: magic mismatch");
+			goto failed_mount;
+		}
+	}
+
+	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
+	sb->s_max_links = EXT2_LINK_MAX;
+	sb->s_time_min = S32_MIN;
+	sb->s_time_max = S32_MAX;
+
+	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
+		sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
+		sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
+	} else {
+		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
+		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
+		if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
+		    !is_power_of_2(sbi->s_inode_size) ||
+		    (sbi->s_inode_size > blocksize)) {
+			ext2_msg(sb, KERN_ERR,
+				"error: unsupported inode size: %d",
+				sbi->s_inode_size);
+			goto failed_mount;
+		}
+	}
+
+	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
+	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
+
+	sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
+	if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
+		goto cantfind_ext2;
+	sbi->s_itb_per_group = sbi->s_inodes_per_group /
+					sbi->s_inodes_per_block;
+	sbi->s_desc_per_block = sb->s_blocksize /
+					sizeof (struct ext2_group_desc);
+	sbi->s_sbh = bh;
+	sbi->s_mount_state = le16_to_cpu(es->s_state);
+	sbi->s_addr_per_block_bits =
+		ilog2 (EXT2_ADDR_PER_BLOCK(sb));
+	sbi->s_desc_per_block_bits =
+		ilog2 (EXT2_DESC_PER_BLOCK(sb));
+
+	if (sb->s_magic != EXT2_SUPER_MAGIC)
+		goto cantfind_ext2;
+
+	if (sb->s_blocksize != bh->b_size) {
+		if (!silent)
+			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
+		goto failed_mount;
+	}
+
+	if (es->s_log_frag_size != es->s_log_block_size) {
+		ext2_msg(sb, KERN_ERR,
+			"error: fragsize log %u != blocksize log %u",
+			le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);
+		goto failed_mount;
+	}
+
+	if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
+		ext2_msg(sb, KERN_ERR,
+			"error: #blocks per group too big: %lu",
+			sbi->s_blocks_per_group);
+		goto failed_mount;
+	}
+	/* At least inode table, bitmaps, and sb have to fit in one group */
+	if (sbi->s_blocks_per_group <= sbi->s_itb_per_group + 3) {
+		ext2_msg(sb, KERN_ERR,
+			"error: #blocks per group smaller than metadata size: %lu <= %lu",
+			sbi->s_blocks_per_group, sbi->s_inodes_per_group + 3);
+		goto failed_mount;
+	}
+	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
+	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
+		ext2_msg(sb, KERN_ERR,
+			"error: invalid #inodes per group: %lu",
+			sbi->s_inodes_per_group);
+		goto failed_mount;
+	}
+	if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {
+		ext2_msg(sb, KERN_ERR,
+			 "bad geometry: block count %u exceeds size of device (%u blocks)",
+			 le32_to_cpu(es->s_blocks_count),
+			 (unsigned)sb_bdev_nr_blocks(sb));
+		goto failed_mount;
+	}
+
+	sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+				le32_to_cpu(es->s_first_data_block) - 1)
+					/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;
+	if ((u64)sbi->s_groups_count * sbi->s_inodes_per_group !=
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",
+			 le32_to_cpu(es->s_inodes_count),
+			 (u64)sbi->s_groups_count * sbi->s_inodes_per_group);
+		goto failed_mount;
+	}
+	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
+		   EXT2_DESC_PER_BLOCK(sb);
+	sbi->s_group_desc = kvmalloc_objs(struct buffer_head *, db_count);
+	if (sbi->s_group_desc == NULL) {
+		ret = -ENOMEM;
+		ext2_msg(sb, KERN_ERR, "error: not enough memory");
+		goto failed_mount;
+	}
+	bgl_lock_init(sbi->s_blockgroup_lock);
+	sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
+	if (!sbi->s_debts) {
+		ret = -ENOMEM;
+		ext2_msg(sb, KERN_ERR, "error: not enough memory");
+		goto failed_mount_group_desc;
+	}
+	for (i = 0; i < db_count; i++) {
+		block = descriptor_loc(sb, logic_sb_block, i);
+		sbi->s_group_desc[i] = sb_bread(sb, block);
+		if (!sbi->s_group_desc[i]) {
+			for (j = 0; j < i; j++)
+				brelse (sbi->s_group_desc[j]);
+			ext2_msg(sb, KERN_ERR,
+				"error: unable to read group descriptors");
+			goto failed_mount_group_desc;
+		}
+	}
+	if (!ext2_check_descriptors (sb)) {
+		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
+		goto failed_mount2;
+	}
+	sbi->s_gdb_count = db_count;
+	sbi->s_next_generation = get_random_u32();
+	spin_lock_init(&sbi->s_next_gen_lock);
+
+	/* per filesystem reservation list head & lock */
+	spin_lock_init(&sbi->s_rsv_window_lock);
+	sbi->s_rsv_window_root = RB_ROOT;
+	/*
+	 * Add a single, static dummy reservation to the start of the
+	 * reservation window list --- it gives us a placeholder for
+	 * append-at-start-of-list which makes the allocation logic
+	 * _much_ simpler.
+	 */
+	sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+	sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
+	sbi->s_rsv_window_head.rsv_alloc_hit = 0;
+	sbi->s_rsv_window_head.rsv_goal_size = 0;
+	ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
+
+	err = percpu_counter_init(&sbi->s_freeblocks_counter,
+				ext2_count_free_blocks(sb), GFP_KERNEL);
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_freeinodes_counter,
+				ext2_count_free_inodes(sb), GFP_KERNEL);
+	}
+	if (!err) {
+		err = percpu_counter_init(&sbi->s_dirs_counter,
+				ext2_count_dirs(sb), GFP_KERNEL);
+	}
+	if (err) {
+		ret = err;
+		ext2_msg(sb, KERN_ERR, "error: insufficient memory");
+		goto failed_mount3;
+	}
+
+#ifdef CONFIG_EXT2_FS_XATTR
+	sbi->s_ea_block_cache = ext2_xattr_create_cache();
+	if (!sbi->s_ea_block_cache) {
+		ret = -ENOMEM;
+		ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
+		goto failed_mount3;
+	}
+#endif
+	/*
+	 * set up enough so that it can read an inode
+	 */
+	sb->s_op = &ext2_sops;
+	sb->s_export_op = &ext2_export_ops;
+	sb->s_xattr = ext2_xattr_handlers;
+
+#ifdef CONFIG_QUOTA
+	sb->dq_op = &dquot_operations;
+	sb->s_qcop = &ext2_quotactl_ops;
+	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+#endif
+
+	root = ext2_iget(sb, EXT2_ROOT_INO);
+	if (IS_ERR(root)) {
+		ret = PTR_ERR(root);
+		goto failed_mount3;
+	}
+	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+		iput(root);
+		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
+		goto failed_mount3;
+	}
+
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		ext2_msg(sb, KERN_ERR, "error: get root inode failed");
+		ret = -ENOMEM;
+		goto failed_mount3;
+	}
+	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
+		ext2_msg(sb, KERN_WARNING,
+			"warning: mounting ext3 filesystem as ext2");
+	if (ext2_setup_super (sb, es, sb_rdonly(sb)))
+		sb->s_flags |= SB_RDONLY;
+	ext2_write_super(sb);
+	return 0;
+
+cantfind_ext2:
+	if (!silent)
+		ext2_msg(sb, KERN_ERR,
+			"error: can't find an ext2 filesystem on dev %s.",
+			sb->s_id);
+	goto failed_mount;
+failed_mount3:
+	ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
+	percpu_counter_destroy(&sbi->s_freeblocks_counter);
+	percpu_counter_destroy(&sbi->s_freeinodes_counter);
+	percpu_counter_destroy(&sbi->s_dirs_counter);
+failed_mount2:
+	for (i = 0; i < db_count; i++)
+		brelse(sbi->s_group_desc[i]);
+failed_mount_group_desc:
+	kvfree(sbi->s_group_desc);
+	kfree(sbi->s_debts);
+failed_mount:
+	brelse(bh);
+failed_sbi:
+	sb->s_fs_info = NULL;
+	kfree(sbi->s_blockgroup_lock);
+	kfree(sbi);
+	return ret;
+}
+
+static void ext2_clear_super_error(struct super_block *sb)
+{
+	struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
+
+	if (buffer_write_io_error(sbh)) {
+		/*
+		 * Oh, dear.  A previous attempt to write the
+		 * superblock failed.  This could happen because the
+		 * USB device was yanked out.  Or it could happen to
+		 * be a transient write error and maybe the block will
+		 * be remapped.  Nothing we can do but to retry the
+		 * write and hope for the best.
+		 */
+		ext2_msg(sb, KERN_ERR,
+		       "previous I/O error to superblock detected");
+		clear_buffer_write_io_error(sbh);
+		set_buffer_uptodate(sbh);
+	}
+}
+
+void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
+		     int wait)
+{
+	ext2_clear_super_error(sb);
+	spin_lock(&EXT2_SB(sb)->s_lock);
+	es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
+	es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
+	es->s_wtime = cpu_to_le32(ktime_get_real_seconds());
+	/* unlock before we do IO */
+	spin_unlock(&EXT2_SB(sb)->s_lock);
+	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
+	if (wait)
+		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
+}
+
+/*
+ * In the second extended file system, it is not necessary to
+ * write the super block since we use a mapping of the
+ * disk super block in a buffer.
+ *
+ * However, this function is still used to set the fs valid
+ * flags to 0.  We need to set this flag to 0 since the fs
+ * may have been checked while mounted and e2fsck may have
+ * set s_state to EXT2_VALID_FS after some corrections.
+ */
+static int ext2_sync_fs(struct super_block *sb, int wait)
+{
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+	struct ext2_super_block *es = EXT2_SB(sb)->s_es;
+
+	/*
+	 * Write quota structures to quota file, sync_blockdev() will write
+	 * them to disk later
+	 */
+	dquot_writeback_dquots(sb, -1);
+
+	spin_lock(&sbi->s_lock);
+	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
+		ext2_debug("setting valid to 0\n");
+		es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
+	}
+	spin_unlock(&sbi->s_lock);
+	ext2_sync_super(sb, es, wait);
+	return 0;
+}
+
+static int ext2_freeze(struct super_block *sb)
+{
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+	/*
+	 * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
+	 * because we have unattached inodes and thus filesystem is not fully
+	 * consistent.
+	 */
+	if (atomic_long_read(&sb->s_remove_count)) {
+		ext2_sync_fs(sb, 1);
+		return 0;
+	}
+	/* Set EXT2_FS_VALID flag */
+	spin_lock(&sbi->s_lock);
+	sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
+	spin_unlock(&sbi->s_lock);
+	ext2_sync_super(sb, sbi->s_es, 1);
+
+	return 0;
+}
+
+static int ext2_unfreeze(struct super_block *sb)
+{
+	/* Just write sb to clear EXT2_VALID_FS flag */
+	ext2_write_super(sb);
+
+	return 0;
+}
+
+static void ext2_write_super(struct super_block *sb)
+{
+	if (!sb_rdonly(sb))
+		ext2_sync_fs(sb, 1);
+}
+
+static int ext2_reconfigure(struct fs_context *fc)
+{
+	struct ext2_fs_context *ctx = fc->fs_private;
+	struct super_block *sb = fc->root->d_sb;
+	struct ext2_sb_info * sbi = EXT2_SB(sb);
+	struct ext2_super_block * es;
+	struct ext2_mount_options new_opts;
+	int flags = fc->sb_flags;
+	int err;
+
+	sync_filesystem(sb);
+
+	new_opts.s_mount_opt = ctx->vals_s_mount_opt;
+	new_opts.s_resuid = ctx->s_resuid;
+	new_opts.s_resgid = ctx->s_resgid;
+
+	spin_lock(&sbi->s_lock);
+	es = sbi->s_es;
+	if ((bool)(flags & SB_RDONLY) == sb_rdonly(sb))
+		goto out_set;
+	if (flags & SB_RDONLY) {
+		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
+		    !(sbi->s_mount_state & EXT2_VALID_FS))
+			goto out_set;
+
+		/*
+		 * OK, we are remounting a valid rw partition rdonly, so set
+		 * the rdonly flag and then mark the partition as valid again.
+		 */
+		es->s_state = cpu_to_le16(sbi->s_mount_state);
+		es->s_mtime = cpu_to_le32(ktime_get_real_seconds());
+		spin_unlock(&sbi->s_lock);
+
+		err = dquot_suspend(sb, -1);
+		if (err < 0)
+			return err;
+
+		ext2_sync_super(sb, es, 1);
+	} else {
+		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
+					       ~EXT2_FEATURE_RO_COMPAT_SUPP);
+		if (ret) {
+			spin_unlock(&sbi->s_lock);
+			ext2_msg(sb, KERN_WARNING,
+				"warning: couldn't remount RDWR because of "
+				"unsupported optional features (%x).",
+				le32_to_cpu(ret));
+			return -EROFS;
+		}
+		/*
+		 * Mounting a RDONLY partition read-write, so reread and
+		 * store the current valid flag.  (It may have been changed
+		 * by e2fsck since we originally mounted the partition.)
+		 */
+		sbi->s_mount_state = le16_to_cpu(es->s_state);
+		if (!ext2_setup_super (sb, es, 0))
+			sb->s_flags &= ~SB_RDONLY;
+		spin_unlock(&sbi->s_lock);
+
+		ext2_write_super(sb);
+
+		dquot_resume(sb, -1);
+	}
+
+	spin_lock(&sbi->s_lock);
+out_set:
+	sbi->s_mount_opt = new_opts.s_mount_opt;
+	sbi->s_resuid = new_opts.s_resuid;
+	sbi->s_resgid = new_opts.s_resgid;
+	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
+	spin_unlock(&sbi->s_lock);
+
+	return 0;
+}
+
+static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct ext2_sb_info *sbi = EXT2_SB(sb);
+	struct ext2_super_block *es = sbi->s_es;
+
+	spin_lock(&sbi->s_lock);
+
+	if (test_opt (sb, MINIX_DF))
+		sbi->s_overhead_last = 0;
+	else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
+		unsigned long i, overhead = 0;
+		smp_rmb();
+
+		/*
+		 * Compute the overhead (FS structures). This is constant
+		 * for a given filesystem unless the number of block groups
+		 * changes so we cache the previous value until it does.
+		 */
+
+		/*
+		 * All of the blocks before first_data_block are
+		 * overhead
+		 */
+		overhead = le32_to_cpu(es->s_first_data_block);
+
+		/*
+		 * Add the overhead attributed to the superblock and
+		 * block group descriptors.  If the sparse superblocks
+		 * feature is turned on, then not all groups have this.
+		 */
+		for (i = 0; i < sbi->s_groups_count; i++)
+			overhead += ext2_bg_has_super(sb, i) +
+				ext2_bg_num_gdb(sb, i);
+
+		/*
+		 * Every block group has an inode bitmap, a block
+		 * bitmap, and an inode table.
+		 */
+		overhead += (sbi->s_groups_count *
+			     (2 + sbi->s_itb_per_group));
+		sbi->s_overhead_last = overhead;
+		smp_wmb();
+		sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
+	}
+
+	buf->f_type = EXT2_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
+	buf->f_bfree = ext2_count_free_blocks(sb);
+	es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
+	buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
+	if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
+		buf->f_bavail = 0;
+	buf->f_files = le32_to_cpu(es->s_inodes_count);
+	buf->f_ffree = ext2_count_free_inodes(sb);
+	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
+	buf->f_namelen = EXT2_NAME_LEN;
+	buf->f_fsid = uuid_to_fsid(es->s_uuid);
+	spin_unlock(&sbi->s_lock);
+	return 0;
+}
+
+static int ext2_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, ext2_fill_super);
+}
+
+#ifdef CONFIG_QUOTA
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and no one else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
+			       size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+	int err = 0;
+	int offset = off & (sb->s_blocksize - 1);
+	int tocopy;
+	size_t toread;
+	struct buffer_head tmp_bh;
+	struct buffer_head *bh;
+	loff_t i_size = i_size_read(inode);
+
+	if (off > i_size)
+		return 0;
+	if (off+len > i_size)
+		len = i_size-off;
+	toread = len;
+	while (toread > 0) {
+		tocopy = min_t(size_t, sb->s_blocksize - offset, toread);
+
+		tmp_bh.b_state = 0;
+		tmp_bh.b_size = sb->s_blocksize;
+		err = ext2_get_block(inode, blk, &tmp_bh, 0);
+		if (err < 0)
+			return err;
+		if (!buffer_mapped(&tmp_bh))	/* A hole? */
+			memset(data, 0, tocopy);
+		else {
+			bh = sb_bread(sb, tmp_bh.b_blocknr);
+			if (!bh)
+				return -EIO;
+			memcpy(data, bh->b_data+offset, tocopy);
+			brelse(bh);
+		}
+		offset = 0;
+		toread -= tocopy;
+		data += tocopy;
+		blk++;
+	}
+	return len;
+}
+
+/* Write to quotafile */
+static ssize_t ext2_quota_write(struct super_block *sb, int type,
+				const char *data, size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
+	int err = 0;
+	int offset = off & (sb->s_blocksize - 1);
+	int tocopy;
+	size_t towrite = len;
+	struct buffer_head tmp_bh;
+	struct buffer_head *bh;
+
+	while (towrite > 0) {
+		tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);
+
+		tmp_bh.b_state = 0;
+		tmp_bh.b_size = sb->s_blocksize;
+		err = ext2_get_block(inode, blk, &tmp_bh, 1);
+		if (err < 0)
+			goto out;
+		if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
+			bh = sb_bread(sb, tmp_bh.b_blocknr);
+		else
+			bh = sb_getblk(sb, tmp_bh.b_blocknr);
+		if (unlikely(!bh)) {
+			err = -EIO;
+			goto out;
+		}
+		lock_buffer(bh);
+		memcpy(bh->b_data+offset, data, tocopy);
+		flush_dcache_folio(bh->b_folio);
+		set_buffer_uptodate(bh);
+		mark_buffer_dirty(bh);
+		unlock_buffer(bh);
+		brelse(bh);
+		offset = 0;
+		towrite -= tocopy;
+		data += tocopy;
+		blk++;
+	}
+out:
+	if (len == towrite)
+		return err;
+	if (inode->i_size < off+len-towrite)
+		i_size_write(inode, off+len-towrite);
+	inode_inc_iversion(inode);
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	mark_inode_dirty(inode);
+	return len - towrite;
+}
+
+static int ext2_quota_on(struct super_block *sb, int type, int format_id,
+			 const struct path *path)
+{
+	int err;
+	struct inode *inode;
+
+	err = dquot_quota_on(sb, type, format_id, path);
+	if (err)
+		return err;
+
+	inode = d_inode(path->dentry);
+	inode_lock(inode);
+	EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
+	inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
+			S_NOATIME | S_IMMUTABLE);
+	inode_unlock(inode);
+	mark_inode_dirty(inode);
+
+	return 0;
+}
+
+static int ext2_quota_off(struct super_block *sb, int type)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	int err;
+
+	if (!inode || !igrab(inode))
+		goto out;
+
+	err = dquot_quota_off(sb, type);
+	if (err)
+		goto out_put;
+
+	inode_lock(inode);
+	EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
+	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
+	inode_unlock(inode);
+	mark_inode_dirty(inode);
+out_put:
+	iput(inode);
+	return err;
+out:
+	return dquot_quota_off(sb, type);
+}
+
+#endif
+
+static const struct fs_context_operations ext2_context_ops = {
+	.parse_param	= ext2_parse_param,
+	.get_tree	= ext2_get_tree,
+	.reconfigure	= ext2_reconfigure,
+	.free		= ext2_free_fc,
+};
+
+static int ext2_init_fs_context(struct fs_context *fc)
+{
+	struct ext2_fs_context *ctx;
+
+	ctx = kzalloc_obj(*ctx);
+	if (!ctx)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct ext2_sb_info *sbi = EXT2_SB(sb);
+
+		spin_lock(&sbi->s_lock);
+		ctx->vals_s_mount_opt = sbi->s_mount_opt;
+		ctx->vals_s_flags = sb->s_flags;
+		ctx->s_resuid = sbi->s_resuid;
+		ctx->s_resgid = sbi->s_resgid;
+		spin_unlock(&sbi->s_lock);
+	} else {
+		ctx->s_sb_block = 1;
+		ctx_set_mount_opt(ctx, EXT2_MOUNT_RESERVATION);
+	}
+
+	fc->fs_private = ctx;
+	fc->ops = &ext2_context_ops;
+
+	return 0;
+}
+
+static struct file_system_type ext2_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "ext2",
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = ext2_init_fs_context,
+	.parameters	= ext2_param_spec,
+};
+MODULE_ALIAS_FS("ext2");
+
+static int __init init_ext2_fs(void)
+{
+	int err;
+
+	err = init_inodecache();
+	if (err)
+		return err;
+	err = register_filesystem(&ext2_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+	return err;
+}
+
+static void __exit exit_ext2_fs(void)
+{
+	unregister_filesystem(&ext2_fs_type);
+	destroy_inodecache();
+}
+
+MODULE_AUTHOR("Remy Card and others");
+MODULE_DESCRIPTION("Second Extended Filesystem");
+MODULE_LICENSE("GPL");
+module_init(init_ext2_fs)
+module_exit(exit_ext2_fs)