From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932422Ab2LNVMI (ORCPT ); Fri, 14 Dec 2012 16:12:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49279 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932367Ab2LNVMH (ORCPT ); Fri, 14 Dec 2012 16:12:07 -0500 Date: Fri, 14 Dec 2012 16:11:59 -0500 From: Mike Snitzer To: Joseph Salisbury Cc: martin.petersen@oracle.com, Kernel Team , linux-kernel@vger.kernel.org, jgarzik@redhat.com, JBottomley@Parallels.com, Milan Broz Subject: Re: [v3.7 Regression] [SCSI] sd: Implement support for WRITE SAME Message-ID: <20121214211159.GA4204@redhat.com> References: <50CB8C74.3090102@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50CB8C74.3090102@canonical.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 On Fri, Dec 14 2012 at 3:30pm -0500, Joseph Salisbury wrote: > Hi Martin, > > A bug was opened against the Ubuntu kernel[0]. After a kernel > bisect, it was found that reverting the following commit resolved > this bug: > > commit 5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd > Author: Martin K. Petersen > Date: Tue Sep 18 12:19:32 2012 -0400 > [SCSI] sd: Implement support for WRITE SAME > > The regression was introduced as of v3.7-rc7. > > The bug can be reproduced with the following commands, which will > operate on a virtual scsi_debug device, so they won't change any > data on the test system. However, this will completely crash the > system: > > sudo modprobe scsi_debug > sudo luksformat -t ext4 /dev/sdb <- Or whatever device gets assigned > after inserting scsi_debug. > sudo cryptsetup luksOpen /dev/sdb treasure > > Everything works fine up to here, but the following will cause the crash: > > sudo mount /dev/mapper/treasure /mnt > > The bug can be reproduced on bare metal, in a VM and on i386 or amd64. > > I see that you are the author of this patch, so I wanted to run this > by you. I was thinking of requesting a revert for v3.7, but I > wanted to get your feedback first. > > > Thanks, > > Joe > > > [0] https://bugs.launchpad.net/bugs/1089818 The WRITE SAME change was introduced long before v3.7-rc7. I think your bisect is somehow wrong. Milan Broz recently pointed out issues he found with luks when using a late 3.7-rc (rc7 afaik). Linus fixed that issue with this commit (which landed in the final v3.7): http://git.kernel.org/linus/684c9aaebbb0ea3a9954 That may not be _the_ problem though. But have you tried the final v3.7? Mike