From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753076AbXBJKAM (ORCPT ); Sat, 10 Feb 2007 05:00:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753081AbXBJKAM (ORCPT ); Sat, 10 Feb 2007 05:00:12 -0500 Received: from mtagate3.de.ibm.com ([195.212.29.152]:27500 "EHLO mtagate3.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753076AbXBJKAK (ORCPT ); Sat, 10 Feb 2007 05:00:10 -0500 Date: Sat, 10 Feb 2007 10:58:58 +0100 From: Heiko Carstens To: Andrew Morton , Alasdair G Kergon , dm-devel@redhat.com, Neil Brown Cc: linux-kernel@vger.kernel.org Subject: Re: -mm merge plans for 2.6.21 -- md-dm-reduce-stack-usage-with-stacked-block-devices.patch Message-ID: <20070210095858.GA8145@osiris.boeblingen.de.ibm.com> References: <20070208150710.1324f6b4.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070208150710.1324f6b4.akpm@linux-foundation.org> User-Agent: mutt-ng/devel-r804 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 08, 2007 at 03:07:10PM -0800, Andrew Morton wrote: > drivers-mdc-use-array_size-macro-when-appropriate.patch > md-dm-reduce-stack-usage-with-stacked-block-devices.patch > > -> neilb > > (The second one is getting idiotic. When are we going to fix this??) Since it was me who asked to have the stack usage reduced and Neil was kind enough to fix this, I'm wondering what the state of dm is. I think more than a year ago we had this: Alasdair G Kergon said: I can see nothing wrong with this in principle. For device-mapper at the moment though it's essential that, while the bio mappings may now get delayed, they still get processed in exactly the same order as they were passed to generic_make_request(). My main concern is whether the timing changes implicit in this patch will make the rare data-corrupting races in the existing snapshot code more likely. (I'm working on a fix for these races, but the unfinished patch is already several hundred lines long.) It would be helpful if some people on this mailing list would test this patch in various scenarios and report back. Alasdair, is dm already fixed or is there any chance that it will ever get fixed?