Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit eeecef0a authored by Eric Sandeen's avatar Eric Sandeen Committed by Theodore Ts'o
Browse files

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 24bcc89c: "jbd2: split
updating of journal superblock and marking journal empty".

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent caecd0af

fs/jbd2/journal.c

+5 −0
Original line number Diff line number Diff line
@@ -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);