I got the problem. I am not sure why old code uses "result <= 0" even if it won't return negative value. Could we use "result == 0" instead of "result <= 0"? On 2015/7/15 22:30, Eryu Guan wrote: > Hi all, > > I found an infinite loop when unmounting a known bad ext3 image (using > ext4 driver) with 4.2-rc1 kernel. > > The fs image can be found here > https://bugzilla.kernel.org/show_bug.cgi?id=10882#c1 > > Reproduce steps: > mount -o loop ext3.img /mnt/ext3 > rm -rf /mnt/ext3/{dev,proc,sys} > umount /mnt/ext3 # never return > > And this issue was introduced by > 6f6a6fd jbd2: fix ocfs2 corrupt when updating journal superblock fails > > It's looping in > fs/jbd2/journal.c:jbd2_journal_destroy() > ... > 1693 while (journal->j_checkpoint_transactions != NULL) { > 1694 spin_unlock(&journal->j_list_lock); > 1695 mutex_lock(&journal->j_checkpoint_mutex); > 1696 jbd2_log_do_checkpoint(journal); > 1697 mutex_unlock(&journal->j_checkpoint_mutex); > 1698 spin_lock(&journal->j_list_lock); > 1699 } > ... > > Because jbd2_cleanup_journal_tail() is returning -EIO on aborted journal > now instead of 1, and jbd2_log_do_checkpoint() won't cleanup > journal->j_checkpoint_transactions in this while loop. > > A quick hack would be > > diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c > index 4227dc4..1b2ea47 100644 > --- a/fs/jbd2/checkpoint.c > +++ b/fs/jbd2/checkpoint.c > @@ -220,11 +220,13 @@ int jbd2_log_do_checkpoint(journal_t *journal) > * don't need checkpointing, just eliminate them from the > * journal straight away. > */ > - result = jbd2_cleanup_journal_tail(journal); > - trace_jbd2_checkpoint(journal, result); > - jbd_debug(1, "cleanup_journal_tail returned %d\n", result); > - if (result <= 0) > - return result; > + if (!is_journal_aborted(journal)) { > + result = jbd2_cleanup_journal_tail(journal); > + trace_jbd2_checkpoint(journal, result); > + jbd_debug(1, "cleanup_journal_tail returned %d\n", result); > + if (result <= 0) > + return result; > + } > > /* > * OK, we need to start writing disk blocks. Take one transaction > > to restore the old behavior (continue on aborted journal). Maybe someone > has a better fix. > > Thanks, > Eryu > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
