Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758924Ab1DNOmV (ORCPT ); Thu, 14 Apr 2011 10:42:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7604 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758881Ab1DNOmU (ORCPT ); Thu, 14 Apr 2011 10:42:20 -0400 Date: Thu, 14 Apr 2011 10:42:09 -0400 From: Mike Snitzer To: "Martin K. Petersen" Cc: Jens Axboe , LKML , James Bottomley , device-mapper development Subject: Re: dm: improve block integrity support Message-ID: <20110414144208.GA26155@redhat.com> References: <20110328230319.GA12790@redhat.com> <4D918347.7050500@fusionio.com> <20110329132032.GA22921@redhat.com> <20110329135800.GB23508@redhat.com> <20110401174259.GA22598@redhat.com> <20110414140925.GA25803@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110414140925.GA25803@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2460 Lines: 58 On Thu, Apr 14 2011 at 10:09am -0400, Mike Snitzer wrote: > [trimming CCs so as not to pester as many people directly] > > On Fri, Apr 01 2011 at 1:42pm -0400, > Mike Snitzer wrote: > > > The current block integrity (DIF/DIX) support in DM is verifying that > > all devices' integrity profiles match during DM device resume (which > > is past the point of no return). To some degree that is unavoidable > > (stacked DM devices force this late checking). But for most DM > > devices (which aren't stacking on other DM devices) the ideal time to > > verify all integrity profiles match is during table load. > > > > Introduce the notion of an "initialized" integrity profile: a profile > > that was blk_integrity_register()'d with a non-NULL 'blk_integrity' > > template. Add blk_integrity_is_initialized() to allow checking if a > > profile was initialized. > > > > Update DM integrity support to: > > - check all devices with _initialized_ integrity profiles match > > during table load; uninitialized profiles (e.g. for underlying DM > > device(s) of a stacked DM device) are ignored. > > - disallow a table load that would result in an integrity profile that > > conflicts with a DM device's existing (in-use) integrity profile > > - avoid clearing an existing integrity profile > > - validate all integrity profiles match during resume; but if they > > don't all we can do is report the mismatch (during resume we're past > > the point of no return) > > > > Signed-off-by: Mike Snitzer > > Cc: Martin K. Petersen > > Hi Martin, > > Any chance you've had a look at this? I'm most interested in whether > the code works with the various integrity profiles you have. > > I'd really like to get this reviewed and queued for upstream so that it > doesn't die on the vine. Ah wow, just noticed this got in through the block tree over a week ago: http://git.kernel.org/linus/a63a5cf84dac7a23a57 Thanks Jens! Martin, I've done enough testing that I am confident the DM integrity support is in a better place with this change. But I'd still really appreciate it if you could verify all is well. Mike -- 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/