only-sync-filesystem-when-remounting-ro

   1 ext4: only call sync_filesystm() when remounting read-only
   2
   3 This is the only time it is required for ext4.
   4
   5 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
   6 ---
   7  fs/ext4/super.c | 5 +++--
   8  1 file changed, 3 insertions(+), 2 deletions(-)
   9
  10 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  11 index aa3842f..01c5088 100644
  12 --- a/fs/ext4/super.c
  13 +++ b/fs/ext4/super.c
  14 @@ -4767,8 +4767,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
  15  #endif
  16         char *orig_data = kstrdup(data, GFP_KERNEL);
  17
  18 -       sync_filesystem(sb);
  19 -
  20         /* Store the original options */
  21         old_sb_flags = sb->s_flags;
  22         old_opts.s_mount_opt = sbi->s_mount_opt;
  23 @@ -4839,6 +4837,9 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
  24                 }
  25
  26                 if (*flags & MS_RDONLY) {
  27 +                       err = sync_filesystem(sb);
  28 +                       if (err < 0)
  29 +                               goto restore_opts;
  30                         err = dquot_suspend(sb, -1);
  31                         if (err < 0)
  32                                 goto restore_opts;