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| author | Eric Sandeen <sandeen@redhat.com> | 2012-08-19 04:29:40 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-08-19 04:29:40 +0200 |
| commit | eeecef0af5ea4efd763c9554cf2bd80fc4a0efd3 (patch) | |
| tree | 161c471b03b931d2e439d7c8ab6e03d5a75a8709 | |
| parent | ext4: replace plain integer with NULL in super.c (diff) | |
| download | linux-eeecef0af5ea4efd763c9554cf2bd80fc4a0efd3.tar.xz linux-eeecef0af5ea4efd763c9554cf2bd80fc4a0efd3.zip | |
jbd2: don't write superblock when if its empty
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>
Cc: stable@vger.kernel.org
| -rw-r--r-- | fs/jbd2/journal.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index bd23f2ebaa67..0f16edd51f67 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1354,6 +1354,11 @@ static void jbd2_mark_journal_empty(journal_t *journal) 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); |