From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752219AbZL3FWQ (ORCPT ); Wed, 30 Dec 2009 00:22:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752196AbZL3FWN (ORCPT ); Wed, 30 Dec 2009 00:22:13 -0500 Received: from mail-ew0-f219.google.com ([209.85.219.219]:57973 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752044AbZL3FVl (ORCPT ); Wed, 30 Dec 2009 00:21:41 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=X050A7/AZsXkeg3D6OXYZxZ2+1iJ+lxANV9yLNrYdoMfiNIsLT+Hk6W7+52wuVT9Ui F/xrNR1sW/wja/lb1Th/hFe0C2rsTOMr7GkjcvZa7F06Z92CxUFb4yApblZR3w8T6qlD xRHFKv/wXLwJQ6iuDSdi9urpmYYZJ9DmB4Uog= From: Frederic Weisbecker To: LKML Cc: LKML , Frederic Weisbecker , Christian Kujau , Yinghai Lu , Alexander Beregalov , Chris Mason , Ingo Molnar Subject: [PATCH 4/4] reiserfs: Relax reiserfs lock while freeing the journal Date: Wed, 30 Dec 2009 06:21:31 +0100 Message-Id: <1262150491-9983-5-git-send-regression-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 In-Reply-To: <1262150491-9983-1-git-send-regression-fweisbec@gmail.com> References: <1262150491-9983-1-git-send-regression-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Keeping the reiserfs lock while freeing the journal on umount path triggers a lock inversion between bdev->bd_mutex and the reiserfs lock. We don't need the reiserfs lock at this stage. The filesystem is not usable anymore, and there are no more pending commits, everything got flushed (even this operation was done in parallel and didn't required the reiserfs lock from the current process). This fixes the following lockdep report: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #172 ------------------------------------------------------- umount/3904 is trying to acquire lock: (&bdev->bd_mutex){+.+.+.}, at: [] __blkdev_put+0x22/0x160 but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&REISERFS_SB(s)->lock){+.+.+.}: [] __lock_acquire+0x11ff/0x19e0 [] lock_acquire+0x68/0x90 [] mutex_lock_nested+0x5b/0x340 [] reiserfs_write_lock_once+0x29/0x50 [] reiserfs_get_block+0x85/0x1620 [] do_mpage_readpage+0x1f0/0x6d0 [] mpage_readpages+0xc0/0x100 [] reiserfs_readpages+0x19/0x20 [] __do_page_cache_readahead+0x1bc/0x260 [] ra_submit+0x28/0x40 [] filemap_fault+0x40e/0x420 [] __do_fault+0x3d/0x430 [] handle_mm_fault+0x12e/0x790 [] do_page_fault+0x135/0x330 [] error_code+0x6b/0x70 [] load_elf_binary+0x82a/0x1a10 [] search_binary_handler+0x90/0x1d0 [] do_execve+0x1df/0x250 [] sys_execve+0x46/0x70 [] syscall_call+0x7/0xb -> #2 (&mm->mmap_sem){++++++}: [] __lock_acquire+0x11ff/0x19e0 [] lock_acquire+0x68/0x90 [] might_fault+0x8b/0xb0 [] copy_to_user+0x32/0x70 [] filldir64+0xa4/0xf0 [] sysfs_readdir+0x116/0x210 [] vfs_readdir+0x8d/0xb0 [] sys_getdents64+0x69/0xb0 [] sysenter_do_call+0x12/0x32 -> #1 (sysfs_mutex){+.+.+.}: [] __lock_acquire+0x11ff/0x19e0 [] lock_acquire+0x68/0x90 [] mutex_lock_nested+0x5b/0x340 [] sysfs_addrm_start+0x2c/0xb0 [] create_dir+0x40/0x90 [] sysfs_create_dir+0x2b/0x50 [] kobject_add_internal+0xc2/0x1b0 [] kobject_add_varg+0x31/0x50 [] kobject_add+0x2c/0x60 [] device_add+0x94/0x560 [] add_partition+0x18a/0x2a0 [] rescan_partitions+0x33a/0x450 [] __blkdev_get+0x12f/0x2d0 [] blkdev_get+0xa/0x10 [] register_disk+0x108/0x130 [] add_disk+0xd9/0x130 [] sd_probe_async+0x105/0x1d0 [] async_thread+0xcf/0x230 [] kthread+0x74/0x80 [] kernel_thread_helper+0x7/0x3c -> #0 (&bdev->bd_mutex){+.+.+.}: [] __lock_acquire+0x18f6/0x19e0 [] lock_acquire+0x68/0x90 [] mutex_lock_nested+0x5b/0x340 [] __blkdev_put+0x22/0x160 [] blkdev_put+0xa/0x10 [] free_journal_ram+0xd2/0x130 [] do_journal_release+0x98/0x190 [] journal_release+0xa/0x10 [] reiserfs_put_super+0x36/0x130 [] generic_shutdown_super+0x4f/0xe0 [] kill_block_super+0x25/0x40 [] reiserfs_kill_sb+0x7f/0x90 [] deactivate_super+0x7a/0x90 [] mntput_no_expire+0x98/0xd0 [] sys_umount+0x4c/0x310 [] sys_oldumount+0x19/0x20 [] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by umount/3904: #0: (&type->s_umount_key#30){+++++.}, at: [] deactivate_super+0x75/0x90 #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x29/0x40 stack backtrace: Pid: 3904, comm: umount Not tainted 2.6.32-atom #172 Call Trace: [] ? printk+0x18/0x1a [] print_circular_bug+0xca/0xd0 [] __lock_acquire+0x18f6/0x19e0 [] ? free_pcppages_bulk+0x1f/0x250 [] lock_acquire+0x68/0x90 [] ? __blkdev_put+0x22/0x160 [] ? __blkdev_put+0x22/0x160 [] mutex_lock_nested+0x5b/0x340 [] ? __blkdev_put+0x22/0x160 [] ? mark_held_locks+0x62/0x80 [] ? kfree+0x92/0xd0 [] __blkdev_put+0x22/0x160 [] ? trace_hardirqs_on+0xb/0x10 [] blkdev_put+0xa/0x10 [] free_journal_ram+0xd2/0x130 [] do_journal_release+0x98/0x190 [] journal_release+0xa/0x10 [] reiserfs_put_super+0x36/0x130 [] ? up_write+0x16/0x30 [] generic_shutdown_super+0x4f/0xe0 [] kill_block_super+0x25/0x40 [] ? vfs_quota_off+0x0/0x20 [] reiserfs_kill_sb+0x7f/0x90 [] deactivate_super+0x7a/0x90 [] mntput_no_expire+0x98/0xd0 [] sys_umount+0x4c/0x310 [] sys_oldumount+0x19/0x20 [] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker Cc: Alexander Beregalov Cc: Chris Mason Cc: Ingo Molnar --- fs/reiserfs/journal.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c index a059879..83ac4d3 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -2009,10 +2009,11 @@ static int do_journal_release(struct reiserfs_transaction_handle *th, destroy_workqueue(commit_wq); commit_wq = NULL; } - reiserfs_write_lock(sb); free_journal_ram(sb); + reiserfs_write_lock(sb); + return 0; } -- 1.6.2.3