commit: 25389bb207987b5774182f763b9fb65ff08761c8 From: Jan Kara <[email protected]> Date: Fri, 23 Nov 2012 14:03:04 +0100 Subject: jbd: Fix lock ordering bug in journal_unmap_buffer()
Commit 09e05d48 introduced a wait for transaction commit into journal_unmap_buffer() in the case we are truncating a buffer undergoing commit in the page stradding i_size on a filesystem with blocksize < pagesize. Sadly we forgot to drop buffer lock before waiting for transaction commit and thus deadlock is possible when kjournald wants to lock the buffer. Fix the problem by dropping the buffer lock before waiting for transaction commit. Since we are still holding page lock (and that is OK), buffer cannot disappear under us. CC: [email protected] # Wherever commit 09e05d48 was taken Signed-off-by: Jan Kara <[email protected]> --- fs/jbd/transaction.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index 78b7f84..7f5120b 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -1961,7 +1961,9 @@ retry: spin_unlock(&journal->j_list_lock); jbd_unlock_bh_state(bh); spin_unlock(&journal->j_state_lock); + unlock_buffer(bh); log_wait_commit(journal, tid); + lock_buffer(bh); goto retry; } /* -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
