Push lock_super() into the ->remount_fs() of filesystems that care about it

Note that since we can't run into contention between remount_fs and write_super
(due to exclusion on s_umount), we have to care only about filesystems that
touch lock_super() on their own.  Out of those ext3, ext4, hpfs, sysv and ufs
do need it; fat doesn't since its ->remount_fs() only accesses assign-once
data (basically, it's "we have no atime on directories and only have atime on
files for vfat; force nodiratime and possibly noatime into *flags").

[folded a build fix from hch]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index a8189864c241..e0a39f1fb88e 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -61,10 +61,12 @@ clean:
 static int sysv_remount(struct super_block *sb, int *flags, char *data)
 {
         struct sysv_sb_info *sbi = SYSV_SB(sb);
+        lock_super(sb);
         if (sbi->s_forced_ro)
                 *flags |= MS_RDONLY;
         if (!(*flags & MS_RDONLY))
                 sb->s_dirt = 1;
+        unlock_super(sb);
         return 0;
 }