From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH 1/2] block: fix leaks associated with discard request payload Date: Sun, 27 Jun 2010 10:16:40 -0400 Message-ID: <20100627141638.GD3970@redhat.com> References: <20100627185927K.fujita.tomonori@lab.ntt.co.jp> <20100627193253P.fujita.tomonori@lab.ntt.co.jp> <20100627110712.GA14511@lst.de> <20100627212952D.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:62849 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755275Ab0F0ORH (ORCPT ); Sun, 27 Jun 2010 10:17:07 -0400 Content-Disposition: inline In-Reply-To: <20100627212952D.fujita.tomonori@lab.ntt.co.jp> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: FUJITA Tomonori Cc: hch@lst.de, axboe@kernel.dk, dm-devel@redhat.com, James.Bottomley@suse.de, linux-kernel@vger.kernel.org, martin.petersen@oracle.com, akpm@linux-foundation.org, linux-scsi@vger.kernel.org On Sun, Jun 27 2010 at 8:32am -0400, FUJITA Tomonori wrote: > On Sun, 27 Jun 2010 13:07:12 +0200 > Christoph Hellwig wrote: > > > > How about this? > > > > As I tried to explain before this utterly confuses the I/O completion > > path. With the patch applied even a simple mkfs.xfs that issues discard > > just hangs. > > Wired. I just tried mkfs.xfs against scsi_debug with my block patches > (I saw one discard command). Seemed that it worked fine. My leak fixes have been tested extensively against all permuations of devices with discards (ATA trim, SCSI UNMAP, SCSI WRTIE SAME w/ unmap=1). I think we need to get Christoph's discard payload transformation complete by fixing the leaks _without_ trying to rework how discard commands are tagged, etc. E.g. fix what Jens already has staged in linux-2.6-block's 'for-next' and 'for-2.6.36'. With that sorted out we can then look at longer term changes to cleanup discard request processing. Regards, Mike