| From | Greg Kroah-Hartman <> | Subject | [ 023/133] jbd2: dont write superblock when if its empty | Date | Thu, 11 Oct 2012 07:50:49 +0900 |
| |
3.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Sandeen <sandeen@redhat.com>
commit eeecef0af5ea4efd763c9554cf2bd80fc4a0efd3 upstream.
This sequence:
# truncate --size=1g fsfile # mkfs.ext4 -F fsfile # mount -o loop,ro fsfile /mnt # umount /mnt # dmesg | tail
results in an IO error when unmounting the RO filesystem:
[ 318.020828] Buffer I/O error on device loop1, logical block 196608 [ 318.027024] lost page write due to I/O error on loop1 [ 318.032088] JBD2: Error -5 detected when updating journal superblock for loop1-8.
This was a regression introduced by commit 24bcc89c7e7c: "jbd2: split updating of journal superblock and marking journal empty".
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/jbd2/journal.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1354,6 +1354,11 @@ static void jbd2_mark_journal_empty(jour BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); read_lock(&journal->j_state_lock); + /* Is it already empty? */ + if (sb->s_start == 0) { + read_unlock(&journal->j_state_lock); + return; + } jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n", journal->j_tail_sequence);
|