Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755280AbaBEUHx (ORCPT ); Wed, 5 Feb 2014 15:07:53 -0500 Received: from mail1.windriver.com ([147.11.146.13]:48499 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755184AbaBEUHZ (ORCPT ); Wed, 5 Feb 2014 15:07:25 -0500 From: Paul Gortmaker To: , CC: Jan Kara , Paul Gortmaker Subject: [v2.6.34-stable 165/213] jbd: Fix lock ordering bug in journal_unmap_buffer() Date: Wed, 5 Feb 2014 15:02:00 -0500 Message-ID: <1391630568-49251-166-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> References: <1391630568-49251-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- 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: Paul Gortmaker --- fs/jbd/transaction.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c index bc8ab97dcd90..590e23885c98 100644 --- a/fs/jbd/transaction.c +++ b/fs/jbd/transaction.c @@ -1956,7 +1956,9 @@ 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; } /* -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/