fs: push sync_filesystem() down to the file system's remount_fs()

Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org

43 files changed, 96 insertions, 2 deletions

diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 0ff4bae2c..479ef5a9c 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -213,6 +213,7 @@ static int parse_options(struct super_block *sb, char *options)
 
 static int adfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NODIRATIME;
 	return parse_options(sb, data);
 }
diff --git a/fs/affs/super.c b/fs/affs/super.c
index 45161a832..01c6e07ac 100644
--- a/fs/affs/super.c
+++ b/fs/affs/super.c
@@ -549,6 +549,7 @@ affs_remount(struct super_block *sb, int *flags, char *data)
 
 	pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
 
+	sync_filesystem(sb);
 	*flags |= MS_NODIRATIME;
 
 	memcpy(volume, sbi->s_volume, 32);
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index f95dddced..7192a7e99 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -908,6 +908,7 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
 static int
 befs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	if (!(*flags & MS_RDONLY))
 		return -EINVAL;
 	return 0;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 68891ff7e..feecdfbdf 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1248,6 +1248,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 	unsigned int old_metadata_ratio = fs_info->metadata_ratio;
 	int ret;
 
+	sync_filesystem(sb);
 	btrfs_remount_prepare(fs_info);
 
 	ret = btrfs_parse_options(root, data);
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 3752b9f6d..0d7daf714 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -521,6 +521,7 @@ static int cifs_show_stats(struct seq_file *s, struct dentry *root)
 
 static int cifs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NODIRATIME;
 	return 0;
 }
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 4dcc0d81a..0aa4c4d75 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -96,6 +96,7 @@ void coda_destroy_inodecache(void)
 
 static int coda_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NOATIME;
 	return 0;
 }
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 35b1c7bd1..c01485856 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -227,6 +227,7 @@ static void cramfs_put_super(struct super_block *sb)
 
 static int cramfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 121d2b6d1..01964578a 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -218,6 +218,7 @@ static int debugfs_remount(struct super_block *sb, int *flags, char *data)
 	int err;
 	struct debugfs_fs_info *fsi = sb->s_fs_info;
 
+	sync_filesystem(sb);
 	err = debugfs_parse_options(data, &fsi->mount_opts);
 	if (err)
 		goto fail;
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 61af24e37..91ea0e9a2 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -313,6 +313,7 @@ static int devpts_remount(struct super_block *sb, int *flags, char *data)
 	struct pts_fs_info *fsi = DEVPTS_SB(sb);
 	struct pts_mount_opts *opts = &fsi->mount_opts;
 
+	sync_filesystem(sb);
 	err = parse_mount_options(data, PARSE_REMOUNT, opts);
 
 	/*
diff --git a/fs/efs/super.c b/fs/efs/super.c
index c6f57a74a..4709692cd 100644
--- a/fs/efs/super.c
+++ b/fs/efs/super.c
@@ -113,6 +113,7 @@ static void efs_put_super(struct super_block *s)
 
 static int efs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 20d6697bd..d260115c0 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1254,6 +1254,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
 	unsigned long old_sb_flags;
 	int err;
 
+	sync_filesystem(sb);
 	spin_lock(&sbi->s_lock);
 
 	/* Store the old options */
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 882d4bdfd..b1e30be19 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -2588,6 +2588,8 @@ static int ext3_remount (struct super_block * sb, int * flags, char * data)
 	int i;
 #endif
 
+	sync_filesystem(sb);
+
 	/* Store the original options */
 	old_sb_flags = sb->s_flags;
 	old_opts.s_mount_opt = sbi->s_mount_opt;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b29e1ad49..75e2077f8 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4654,6 +4654,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 #endif
 	char *orig_data = kstrdup(data, GFP_KERNEL);
 
+	sync_filesystem(sb);
+
 	/* Store the original options */
 	old_sb_flags = sb->s_flags;
 	old_opts.s_mount_opt = sbi->s_mount_opt;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8555f7df8..a50dfc299 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -244,6 +244,49 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 	return 0;
 }
 
+static int segment_info_open_fs(struct inode *inode, struct file *file)
+{
+	return single_open(file, segment_info_seq_show, PDE_DATA(inode));
+}
+
+static const struct file_operations f2fs_seq_segment_info_fops = {
+	.owner = THIS_MODULE,
+	.open = segment_info_open_fs,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int f2fs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct f2fs_mount_info org_mount_opt;
+	int err, active_logs;
+
+	sync_filesystem(sb);
+
+	/*
+	 * Save the old mount options in case we
+	 * need to restore them.
+	 */
+	org_mount_opt = sbi->mount_opt;
+	active_logs = sbi->active_logs;
+
+	/* parse mount options */
+	err = parse_options(sb, data);
+	if (err)
+		goto restore_opts;
+
+	/*
+	 * Previous and new state of filesystem is RO,
+	 * so no point in checking GC conditions.
+	 */
+	if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
+		goto skip;
+
+	return 0;
+}
+
 static struct super_operations f2fs_sops = {
 	.alloc_inode	= f2fs_alloc_inode,
 	.drop_inode	= f2fs_drop_inode,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 871ea6a82..e69f87abd 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -661,6 +661,8 @@ static int fat_remount(struct super_block *sb, int *flags, char *data)
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	*flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
 
+	sync_filesystem(sb);
+
 	/* make sure we update state on remount. */
 	new_rdonly = *flags & MS_RDONLY;
 	if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
diff --git a/fs/freevxfs/vxfs_super.c b/fs/freevxfs/vxfs_super.c
index e37eb274e..7ca8c75d5 100644
--- a/fs/freevxfs/vxfs_super.c
+++ b/fs/freevxfs/vxfs_super.c
@@ -124,6 +124,7 @@ vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
 
 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 505fd7388..74904e23c 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -135,6 +135,7 @@ static void fuse_evict_inode(struct inode *inode)
 
 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	if (*flags & MS_MANDLOCK)
 		return -EINVAL;
 
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index e5639dec6..db7fff5a2 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1142,6 +1142,8 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
 	struct gfs2_tune *gt = &sdp->sd_tune;
 	int error;
 
+	sync_filesystem(sb);
+
 	spin_lock(&gt->gt_spin);
 	args.ar_commit = gt->gt_logd_secs;
 	args.ar_quota_quantum = gt->gt_quota_quantum;
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 2d2039e75..eee7206c3 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -112,6 +112,7 @@ static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static int hfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NODIRATIME;
 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 		return 0;
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 4c4d142cf..1b9414f70 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -323,6 +323,7 @@ static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 		return 0;
 	if (!(*flags & MS_RDONLY)) {
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index 2c1ce192a..0d4b1f657 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -398,6 +398,8 @@ static int hpfs_remount_fs(struct super_block *s, int *flags, char *data)
 	struct hpfs_sb_info *sbi = hpfs_sb(s);
 	char *new_opts = kstrdup(data, GFP_KERNEL);
 	
+	sync_filesystem(s);
+
 	*flags |= MS_NOATIME;
 	
 	hpfs_lock(s);
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 10489bbd4..5a4d03ca8 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -125,6 +125,7 @@ static void destroy_inodecache(void)
 
 static int isofs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	if (!(*flags & MS_RDONLY))
 		return -EROFS;
 	return 0;
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 0defb1cc2..0918f0e2e 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -243,6 +243,7 @@ static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 	int err;
 
+	sync_filesystem(sb);
 	err = jffs2_parse_options(c, data);
 	if (err)
 		return -EINVAL;
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 788e0a9c1..b7486dafa 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -413,6 +413,7 @@ static int jfs_remount(struct super_block *sb, int *flags, char *data)
 	int flag = JFS_SBI(sb)->flag;
 	int ret;
 
+	sync_filesystem(sb);
 	if (!parse_options(data, sb, &newLVSize, &flag)) {
 		return -EINVAL;
 	}
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index df122496f..a54d08865 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -123,6 +123,7 @@ static int minix_remount (struct super_block * sb, int * flags, char * data)
 	struct minix_sb_info * sbi = minix_sb(sb);
 	struct minix_super_block * ms;
 
+	sync_filesystem(sb);
 	ms = sbi->s_ms;
 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 		return 0;
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 26910c815..3f54348b9 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -99,6 +99,7 @@ static void destroy_inodecache(void)
 
 static int ncp_remount(struct super_block *sb, int *flags, char* data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NODIRATIME;
 	return 0;
 }
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 2d7525fbc..d85c1b819 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2133,6 +2133,8 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
 
+	sync_filesystem(sb);
+
 	/*
 	 * Userspace mount programs that send binary options generally send
 	 * them populated with default values. We have no way to know which
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index c7d1f9f18..4b0a8d4a8 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1114,6 +1114,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data)
 	unsigned long old_mount_opt;
 	int err;
 
+	sync_filesystem(sb);
 	old_sb_flags = sb->s_flags;
 	old_mount_opt = nilfs->ns_mount_opt;
 
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 82650d52d..bd5610d48 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -468,6 +468,8 @@ static int ntfs_remount(struct super_block *sb, int *flags, char *opt)
 
 	ntfs_debug("Entering with remount options string: %s", opt);
 
+	sync_filesystem(sb);
+
 #ifndef NTFS_RW
 	/* For read-only compiled driver, enforce read-only flag. */
 	*flags |= MS_RDONLY;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 01b851655..616bde667 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -632,6 +632,8 @@ static int ocfs2_remount(struct super_block *sb, int *flags, char *data)
 	struct ocfs2_super *osb = OCFS2_SB(sb);
 	u32 tmp;
 
+	sync_filesystem(sb);
+
 	if (!ocfs2_parse_options(sb, data, &parsed_options, 1) ||
 	    !ocfs2_check_set_options(sb, &parsed_options)) {
 		ret = -EINVAL;
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index 75885ffde..f4026aba2 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -375,6 +375,7 @@ static struct inode *openprom_iget(struct super_block *sb, ino_t ino)
 
 static int openprom_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_NOATIME;
 	return 0;
 }
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 04ec276c7..3df19e6e1 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -92,6 +92,8 @@ static int proc_parse_options(char *options, struct pid_namespace *pid)
 int proc_remount(struct super_block *sb, int *flags, char *data)
 {
 	struct pid_namespace *pid = sb->s_fs_info;
+
+	sync_filesystem(sb);
 	return !proc_parse_options(data, pid);
 }
 
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 0931baf93..a3d6a4b29 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -249,6 +249,7 @@ static void parse_options(char *options)
 
 static int pstore_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	parse_options(data);
 
 	return 0;
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index 2e8caa62d..3410e9f65 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -46,6 +46,7 @@ static int qnx4_remount(struct super_block *sb, int *flags, char *data)
 {
 	struct qnx4_sb_info *qs;
 
+	sync_filesystem(sb);
 	qs = qnx4_sb(sb);
 	qs->Version = QNX4_VERSION;
 	*flags |= MS_RDONLY;
diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c
index 8d941edfe..65cdaab3e 100644
--- a/fs/qnx6/inode.c
+++ b/fs/qnx6/inode.c
@@ -55,6 +55,7 @@ static int qnx6_show_options(struct seq_file *seq, struct dentry *root)
 
 static int qnx6_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index e2e202a07..460f762a8 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -1317,6 +1317,7 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
 	int i;
 #endif
 
+	sync_filesystem(s);
 	reiserfs_write_lock(s);
 
 #ifdef CONFIG_QUOTA
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 15cbc41ee..ae839482c 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -435,6 +435,7 @@ static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  */
 static int romfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 60553a905..c8e640ee6 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -371,6 +371,7 @@ static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static int squashfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	sync_filesystem(sb);
 	*flags |= MS_RDONLY;
 	return 0;
 }
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index 7b3792e58..2829b66eb 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -60,6 +60,7 @@ static int sysv_remount(struct super_block *sb, int *flags, char *data)
 {
 	struct sysv_sb_info *sbi = SYSV_SB(sb);
 
+	sync_filesystem(sb);
 	if (sbi->s_forced_ro)
 		*flags |= MS_RDONLY;
 	return 0;
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 6ea200d90..20c777e24 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1862,6 +1862,7 @@ static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
 	int err;
 	struct ubifs_info *c = sb->s_fs_info;
 
+	sync_filesystem(sb);
 	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
 
 	err = ubifs_parse_options(c, data, 1);
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 839a2bad7..3ea63ca1a 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -630,8 +630,9 @@ static int udf_remount_fs(struct super_block *sb, int *flags, char *options)
 	struct udf_sb_info *sbi = UDF_SB(sb);
 	int error = 0;
 
-	if (sbi->s_lvid_bh) {
-		int write_rev = le16_to_cpu(udf_sb_lvidiu(sbi)->minUDFWriteRev);
+	sync_filesystem(sb);
+	if (lvidiu) {
+		int write_rev = le16_to_cpu(lvidiu->minUDFWriteRev);
 		if (write_rev > UDF_MAX_WRITE_VERSION && !(*flags & MS_RDONLY))
 			return -EACCES;
 	}
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 329f2f53b..b8c6791f0 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -1280,6 +1280,7 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
 	unsigned new_mount_opt, ufstype;
 	unsigned flags;
 
+	sync_filesystem(sb);
 	lock_ufs(sb);
 	mutex_lock(&UFS_SB(sb)->s_lock);
 	uspi = UFS_SB(sb)->s_uspi;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 3033ba5e9..478c0ad5e 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1218,6 +1218,7 @@ xfs_fs_remount(
 	char			*p;
 	int			error;
 
+	sync_filesystem(sb);
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;