From 1c4e871038f17769d943d4473c339171fed70f45 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 23 Nov 2012 14:03:04 +0100 Subject: jbd: Fix lock ordering bug in journal_unmap_buffer() commit 25389bb207987b5774182f763b9fb65ff08761c8 upstream. 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. Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/jbd/transaction.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index b0161a66d35a..d7ab0926832e 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -1955,7 +1955,9 @@ 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; } /* -- cgit v1.2.3