From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v2] dm: Fix alignment stacking on partitioned devices Date: Wed, 23 Dec 2009 14:21:40 -0500 Message-ID: <20091223192139.GA29535@redhat.com> References: <1261591640-24380-1-git-send-email-snitzer@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1261591640-24380-1-git-send-email-snitzer@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Alasdair G Kergon Cc: dm-devel@redhat.com, "Martin K. Petersen" List-Id: dm-devel.ids On Wed, Dec 23 2009 at 1:07pm -0500, Mike Snitzer wrote: > From: Martin K. Petersen > > The DM device limits function passes the start offset within the block > device to the block layer stacking function. The stacking function > expects the provided start offset to be relative to start of the disk > (request_queue). Until now DM was passing a start offset that was > relative to beginning of the partition (block_device), resulting in > incorrect alignment stacking. > > Add the partition offset to the values passed to blk_stack_limits(). > > Also clarify, in the DMWARN message, that the device which caused > blk_stack_limits() to return failure isn't necessarily misaligned > itself. It caused the top-level (DM) device to have inconsistent > alignment when taken in combination with all previously stacked > device(s). Alasdair, This should be pushed as a fix for 2.6.33. It should probably go to stable (2.6.31.y and 2.6.32.y) too. Mike