From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756241Ab0EaOqx (ORCPT ); Mon, 31 May 2010 10:46:53 -0400 Received: from mtagate7.de.ibm.com ([195.212.17.167]:39343 "EHLO mtagate7.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756108Ab0EaOqu (ORCPT ); Mon, 31 May 2010 10:46:50 -0400 Date: Mon, 31 May 2010 16:46:49 +0200 From: Christof Schmitt To: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: Wrong DIF guard tag on ext2 write Message-ID: <20100531144648.GA19068@schmichrtp.mainz.de.ibm.com> References: <20100531112817.GA16260@schmichrtp.mainz.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 31, 2010 at 10:20:44AM -0400, Martin K. Petersen wrote: > >>>>> "Christof" == Christof Schmitt writes: > > Christof> Since the guard tags are created in Linux, it seems that the > Christof> data attached to the write request changes between the > Christof> generation in bio_integrity_generate and the call to > Christof> sd_prep_fn. > > Yep, known bug. Page writeback locking is messed up for buffer_head > users. The extNfs folks volunteered to look into this a while back but > I don't think they have found the time yet. Thanks for the info. This means that this bug appears with all filesystems? > > > Christof> Using ext3 or ext4 instead of ext2 does not show the problem. > > Last I looked there were still code paths in ext3 and ext4 that > permitted pages to be changed during flight. I guess you've just been > lucky. ext3 looks good so far. I see the problem also with ext4, so i spoke too early on that one. I will start a longer testrun with ext3 to see if and when the problem appears with ext3 in my setup. -- Christof Schmitt