From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965655AbcHNLhw (ORCPT ); Sun, 14 Aug 2016 07:37:52 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52495 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934454AbcHNLhs (ORCPT ); Sun, 14 Aug 2016 07:37:48 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Dave Chinner" , "Christoph Hellwig" , "Dave Chinner" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 103/305] xfs: fix inode validity check in xfs_iflush_cluster In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dave Chinner commit 51b07f30a71c27405259a0248206ed4e22adbee2 upstream. Some careless idiot(*) wrote crap code in commit 1a3e8f3 ("xfs: convert inode cache lookups to use RCU locking") back in late 2010, and so xfs_iflush_cluster checks the wrong inode for whether it is still valid under RCU protection. Fix it to lock and check the correct inode. (*) Careless-idiot: Dave Chinner Discovered-by: Brain Foster Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner Signed-off-by: Ben Hutchings --- fs/xfs/xfs_inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -3029,13 +3029,13 @@ xfs_iflush_cluster( * We need to check under the i_flags_lock for a valid inode * here. Skip it if it is not valid or the wrong inode. */ - spin_lock(&ip->i_flags_lock); - if (!ip->i_ino || + spin_lock(&iq->i_flags_lock); + if (!iq->i_ino || (XFS_INO_TO_AGINO(mp, iq->i_ino) & mask) != first_index) { - spin_unlock(&ip->i_flags_lock); + spin_unlock(&iq->i_flags_lock); continue; } - spin_unlock(&ip->i_flags_lock); + spin_unlock(&iq->i_flags_lock); /* * Do an un-protected check to see if the inode is dirty and