From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760059Ab2DKDeT (ORCPT ); Tue, 10 Apr 2012 23:34:19 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:50028 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756162Ab2DKDeS (ORCPT ); Tue, 10 Apr 2012 23:34:18 -0400 X-IronPort-AV: E=Sophos;i="4.75,403,1330876800"; d="scan'208";a="4726663" Message-ID: <4F84F7BC.102@cn.fujitsu.com> Date: Wed, 11 Apr 2012 11:17:16 +0800 From: Ren Mingxin User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20110412 CentOS/3.1.3-1.el6.centos Thunderbird/3.1.3 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Rusty Russell , Kay Sievers , Tokunaga Kei , LKML , UDEV Subject: Re: [RFC PATCH] virtio_blk: Checking "private_data" to avoid kernel panic when hotplugging References: <4F728831.2090406@cn.fujitsu.com> <20120409075318.GB27771@redhat.com> In-Reply-To: <20120409075318.GB27771@redhat.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/04/11 11:16:07, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/04/11 11:16:50, Serialize complete at 2012/04/11 11:16:50 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2012 03:53 PM, Michael S. Tsirkin wrote: > On Wed, Mar 28, 2012 at 11:40:33AM +0800, Ren Mingxin wrote: >> On guest with upstream's kernel(3.3.0-rc7), I >> mounted virtblk as: >> a) # mkfs /dev/vda >> b) # mount /dev/vda /mnt >> c) # cd /mnt >> >> Then I did hotplug for virtblk via virsh on host as: >> a) # sudo virsh detach-disk guest vda >> b) # sudo virsh attach-disk guest /media/data/test.img vda >> >> I encountered guest's kernel panic (*probability* >> *event*)whose backtrace liked this: > Any news here? Managed to trace? Sorry, I had a leave last week. > Does this still happen with 3.4-rc2? I retested this with 3.4-rc2, but the panic couldn't be reproduced. (Last time, It seemed that the upstream's kernel was 3.3-rc7) > There's a chance you are hitting a race fixed by > 4678d6f970c2f7c0cbfefc0cc666432d153b321b. > > If it's still not fixed it might make sense to enable slab debugging - > we might have a use after free here. > I don't think the below commit has fixed this panic issue, for it is included in my last test environment(3.3-rc7). 4678d6f970c2f7c0cbfefc0cc666432d153b321b Now, I'd find which commit makes sense. -- Thanks, Ren