From patchwork Sun Jan 27 13:19:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Bo X-Patchwork-Id: 2051611 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 93B1EDFE86 for ; Sun, 27 Jan 2013 13:23:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756747Ab3A0NW6 (ORCPT ); Sun, 27 Jan 2013 08:22:58 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:24015 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756740Ab3A0NW4 (ORCPT ); Sun, 27 Jan 2013 08:22:56 -0500 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by aserp1040.oracle.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.1) with ESMTP id r0RDMYbv018071 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Sun, 27 Jan 2013 13:22:35 GMT Received: from acsmt357.oracle.com (acsmt357.oracle.com [141.146.40.157]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r0RDMXPR021846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 27 Jan 2013 13:22:33 GMT Received: from abhmt103.oracle.com (abhmt103.oracle.com [141.146.116.55]) by acsmt357.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id r0RDMVQ4009556; Sun, 27 Jan 2013 07:22:31 -0600 Received: from liubo (/222.90.237.181) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 27 Jan 2013 05:22:30 -0800 Date: Sun, 27 Jan 2013 21:19:53 +0800 From: Liu Bo To: Stefan Behrens Cc: Mitch Harder , linux-btrfs@vger.kernel.org, chris.mason@fusionio.com, JBacik@fusionio.com, dave@jikos.cz, kitayama@cl.bb4u.ne.jp, miaox@cn.fujitsu.com Subject: Re: [PATCH V5] Btrfs: snapshot-aware defrag Message-ID: <20130127131952.GB16722@liubo> Reply-To: bo.li.liu@oracle.com References: <1358339768-2314-1-git-send-email-bo.li.liu@oracle.com> <20130123075155.GE17162@liubo.jp.oracle.com> <20130124005221.GA28406@liubo> <5102A76C.5050706@giantdisaster.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5102A76C.5050706@giantdisaster.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, Jan 25, 2013 at 04:40:28PM +0100, Stefan Behrens wrote: > On Fri, 25 Jan 2013 08:55:58 -0600, Mitch Harder wrote: > > On Wed, Jan 23, 2013 at 6:52 PM, Liu Bo wrote: > >> On Wed, Jan 23, 2013 at 10:05:04AM -0600, Mitch Harder wrote: > [...] > Well, the issue that I had reported on IRC some days ago which looks similar (the top part of the call trace is similar: iput -> evict -> destroy_inode -> btrfs_destroy_inode -> btrfs_add_dead_root -> list_add which warns in list_add in your case and crashes in my case) was without Liu Bo's "snapshot-aware defrag" patch. A 3.8.0-rc4 kernel and nothing else. > > The reproducer was to create and destroy subvolumes and snapshots. I used btrfs-receive to fill them with data. The crash happened on umount. Every time. > > del_fs_roots() is attempting to empty the dead_roots list, and via btrfs_destroy_inode() deeper in the call stack they are added back to the dead_roots list. > Hi Stefan, I assume that you're with 'inode_cache' option, since the iput() here refers to static void free_fs_root(struct btrfs_root *root) { iput(root->cache_inode); ... } If my assumption is right, what about the following patch? thanks, liubo struct btrfs_root, root_list); > BUG: unable to handle kernel paging request at ffff88042503b830 > IP: [] __list_add+0x17/0xd0 > PGD 1e0c063 PUD bf58e067 PMD bf6b7067 PTE 800000042503b160 > Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC > Modules linked in: btrfs bonding raid1 mpt2sas scsi_transport_sas raid_class > CPU 2 > Pid: 10259, comm: umount Not tainted 3.8.0-rc4+ #16 Supermicro X8SIL/X8SIL > RIP: 0010:[] [] __list_add+0x17/0xd0 > RSP: 0018:ffff8802f67a1bd8 EFLAGS: 00010286 > RAX: ffff880425b7c560 RBX: ffff880423ca2828 RCX: 0000000000000001 > RDX: ffff88042503b828 RSI: ffff8804257794c0 RDI: ffff880423ca2828 > RBP: ffff8802f67a1bf8 R08: 0000000000077850 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000001 R12: ffff880423ca2000 > R13: ffff880423ca2898 R14: 0000000000000000 R15: ffff8802f67a1d30 > FS: 00007f6e89bba740(0000) GS:ffff88042ea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: ffff88042503b830 CR3: 000000029a56c000 CR4: 00000000000007e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process umount (pid: 10259, threadinfo ffff8802f67a0000, task ffff880425b7c560) > Stack: > ffffffffa00a414f ffff880423ca2000 ffff880423ca2000 ffff880423ca2898 > ffff8802f67a1c18 ffffffffa00a4170 ffff88042a60c1f8 ffff88042a60c1f8 > ffff8802f67a1c48 ffffffffa00b3180 ffff88042a60c1f8 ffff88042a60c280 > Call Trace: > [] ? btrfs_add_dead_root+0x1f/0x60 [btrfs] > [] btrfs_add_dead_root+0x40/0x60 [btrfs] > [] btrfs_destroy_inode+0x1d0/0x2d0 [btrfs] > [] destroy_inode+0x37/0x60 > [] evict+0x10d/0x1a0 > [] iput+0x105/0x190 > [] free_fs_root+0x18/0x90 [btrfs] > [] btrfs_free_fs_root+0x7b/0x90 [btrfs] > [] del_fs_roots+0xaf/0xf0 [btrfs] > [] close_ctree+0x1c6/0x300 [btrfs] > [] ? evict_inodes+0xec/0x100 > [] btrfs_put_super+0x14/0x20 [btrfs] > [] generic_shutdown_super+0x5c/0xe0 > [] kill_anon_super+0x11/0x20 > [] btrfs_kill_super+0x15/0x90 [btrfs] > [] ? deactivate_super+0x41/0x70 > [] deactivate_locked_super+0x3d/0x70 > [] deactivate_super+0x49/0x70 > [] mntput_no_expire+0xd2/0x130 > [] sys_umount+0x71/0x390 > [] system_call_fastpath+0x16/0x1b > Code: 48 83 c4 08 5b 5d c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 48 89 fb 4c 89 6d f8 <4c> 8b 42 08 49 89 f5 49 89 d4 49 39 f0 75 31 4d 8b 45 00 4d 39 > RIP [] __list_add+0x17/0xd0 > RSP > CR2: ffff88042503b830 > ---[ end trace 5e44f1afc74751aa ]--- > --- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 65f0367..01a601b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3220,6 +3220,13 @@ static void del_fs_roots(struct btrfs_fs_info *fs_info) struct btrfs_root *gang[8]; int i; + list_for_each_entry(gang[0], &fs_info->dead_roots, root_list) { + if (gang[0]->in_radix) { + iput(root->cache_inode); + root->cache_inode = NULL; + } + } + while (!list_empty(&fs_info->dead_roots)) { gang[0] = list_entry(fs_info->dead_roots.next,