From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758099AbZEHDEb (ORCPT ); Thu, 7 May 2009 23:04:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762607AbZEHC5W (ORCPT ); Thu, 7 May 2009 22:57:22 -0400 Received: from sandeen.net ([209.173.210.139]:23819 "EHLO mail.sandeen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761996AbZEHC5J (ORCPT ); Thu, 7 May 2009 22:57:09 -0400 Message-ID: <4A039F85.8010506@sandeen.net> Date: Thu, 07 May 2009 21:57:09 -0500 From: Eric Sandeen User-Agent: Thunderbird 2.0.0.21 (Macintosh/20090302) MIME-Version: 1.0 To: Felix Blyakher CC: xfs@oss.sgi.com, kernel-testers@vger.kernel.org, linux-kernel@vger.kernel.org, a.beregalov@gmail.com Subject: Re: [PATCH] xfs: fix double unlock in xfs_swap_extents() References: <1241745202-7452-1-git-send-email-felixb@sgi.com> In-Reply-To: <1241745202-7452-1-git-send-email-felixb@sgi.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Felix Blyakher wrote: > Regreesion from commit ef8f7fc, which rearranged the code in > xfs_swap_extents() leading to double unlock of xfs inode iolock. > That resulted in xfs_fsr deadlocking itself on platforms, which > don't handle double unlock of rw_semaphore nicely. It caused the > count go negative, which represents the write holder, without > really having one. ia64 is one of the platforms where deadlock > was easily reproduced and the fix was tested. > > Signed-off-by: Felix Blyakher Also-written-by: Eric Sandeen Independently-arrived-at-by: Eric Sandeen ;) But seriously ... Reviewed-by: Eric Sandeen > --- > fs/xfs/xfs_dfrag.c | 8 +++++--- > 1 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c > index e6d839b..7465f9e 100644 > --- a/fs/xfs/xfs_dfrag.c > +++ b/fs/xfs/xfs_dfrag.c > @@ -347,13 +347,15 @@ xfs_swap_extents( > > error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT); > > -out_unlock: > - xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); > - xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); > out: > kmem_free(tempifp); > return error; > > +out_unlock: > + xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); > + xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); > + goto out; > + > out_trans_cancel: > xfs_trans_cancel(tp, 0); > goto out_unlock;