From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755085Ab0EaOWa (ORCPT ); Mon, 31 May 2010 10:22:30 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:41557 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754912Ab0EaOW1 (ORCPT ); Mon, 31 May 2010 10:22:27 -0400 To: Christof Schmitt 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 From: "Martin K. Petersen" Organization: Oracle References: <20100531112817.GA16260@schmichrtp.mainz.de.ibm.com> Date: Mon, 31 May 2010 10:20:44 -0400 In-Reply-To: <20100531112817.GA16260@schmichrtp.mainz.de.ibm.com> (Christof Schmitt's message of "Mon, 31 May 2010 13:28:18 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Auth-Type: Internal IP X-Source-IP: acsinet15.oracle.com [141.146.126.227] X-CT-RefId: str=0001.0A090209.4C03C620.00E3:SCFMA922111,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "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. 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. -- Martin K. Petersen Oracle Linux Engineering