Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756877Ab0FANwU (ORCPT ); Tue, 1 Jun 2010 09:52:20 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:24481 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755885Ab0FANwS (ORCPT ); Tue, 1 Jun 2010 09:52:18 -0400 To: James Bottomley Cc: Chris Mason , Christof Schmitt , Boaz Harrosh , "Martin K. Petersen" , 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> <1275318102.2823.47.camel@mulgrave.site> <4C03D5FD.3000202@panasas.com> <20100601103041.GA15922@schmichrtp.mainz.de.ibm.com> <1275398876.21962.6.camel@mulgrave.site> <20100601133341.GK8980@think> <1275399637.21962.11.camel@mulgrave.site> Date: Tue, 01 Jun 2010 09:50:29 -0400 In-Reply-To: <1275399637.21962.11.camel@mulgrave.site> (James Bottomley's message of "Tue, 01 Jun 2010 08:40:37 -0500") 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: rcsinet13.oracle.com [148.87.113.125] X-CT-RefId: str=0001.0A090203.4C05108A.00EA:SCFMA4539811,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1267 Lines: 26 >>>>> "James" == James Bottomley writes: James> Would it be too much work in the fs to mark the page dirty before James> you begin altering it (and again after you finish, just in case James> some cleaner noticed and initiated a write)? Or some other flag James> that indicates page under modification? All the process James> controlling the writeout (which is pretty high up in the stack) James> needs to know is if we triggered the check error by altering the James> page while it was in flight. James> I agree that a block based retry would close all the holes ... it James> just doesn't look elegant to me that the fs will already be James> repeating the I/O if it changed the page and so will block. I experimented with this approach a while back. However, I quickly got into a situation where frequently updated blocks never made it to disk because the page was constantly being updated. And all writes failed with a guard tag error. -- Martin K. Petersen Oracle Linux Engineering -- 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/