From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f44.google.com ([209.85.220.44]:36478 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121Ab3H1A5D (ORCPT ); Tue, 27 Aug 2013 20:57:03 -0400 Received: by mail-pa0-f44.google.com with SMTP id fz6so5548041pac.3 for ; Tue, 27 Aug 2013 17:57:02 -0700 (PDT) Message-ID: <521D4ADB.8010804@inktank.com> Date: Tue, 27 Aug 2013 17:56:59 -0700 From: Dan Mick MIME-Version: 1.0 To: Sage Weil CC: linux-btrfs@vger.kernel.org Subject: Re: bad unlock balance in btrfs_commit_transaction_async References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Another developer just noticed this in testing; anyone have any ideas? On 08/22/2013 05:40 PM, Sage Weil wrote: > I just noticed that there is a locking imbalance warning with sb_internal > in the transaction commit code. I believe this has only started appearing > recently (after I merged -rc5 into my testing tree), but I'm working on > confirming that. The error is > > <4>[27034.835134] ===================================== > <4>[27034.839854] [ BUG: bad unlock balance detected! ] > <4>[27034.844576] 3.11.0-rc5-ceph-00061-g546140d #1 Not tainted > <4>[27034.849992] ------------------------------------- > <4>[27034.854713] ceph-osd/30797 is trying to release lock (sb_internal) at: > <4>[27034.861304] [] btrfs_commit_transaction_async+0x1c8/0x2c0 [btrfs] > <4>[27034.868994] but there are no more locks to release! > <4>[27034.873887] > <4>[27034.873887] other info that might help us debug this: > <4>[27034.880448] no locks held by ceph-osd/30797. > <4>[27034.884733] > <4>[27034.884733] stack backtrace: > <4>[27034.889123] CPU: 0 PID: 30797 Comm: ceph-osd Not tainted 3.11.0-rc5-ceph-00061-g546140d #1 > <4>[27034.897421] Hardware name: Dell Inc. PowerEdge R410/01V648, BIOS 1.6.3 02/07/2011 > <4>[27034.904938] ffffffffa0148fd8 ffff88020baf9c68 ffffffff81642d85 0000000000000007 > <4>[27034.912411] ffff88021b32deb0 ffff88020baf9c98 ffffffff810ab89e ffff88020cff8000 > <4>[27034.919883] 0000000000000246 ffff88020aaeddd0 ffffffffa0148fd8 ffff88020baf9ce8 > <4>[27034.927358] Call Trace: > <4>[27034.929836] [] ? btrfs_commit_transaction_async+0x1c8/0x2c0 [btrfs] > <4>[27034.937790] [] dump_stack+0x46/0x58 > <4>[27034.942951] [] print_unlock_imbalance_bug+0xfe/0x110 > <4>[27034.949599] [] ? btrfs_commit_transaction_async+0x1c8/0x2c0 [btrfs] > <4>[27034.957552] [] lock_release+0x15e/0x220 > <4>[27034.963069] [] btrfs_commit_transaction_async+0x1ef/0x2c0 [btrfs] > <4>[27034.970850] [] ? trace_hardirqs_on_caller+0x105/0x1d0 > <4>[27034.977587] [] btrfs_ioctl_start_sync+0x47/0xc0 [btrfs] > <4>[27034.984499] [] btrfs_ioctl+0xe55/0x1af0 [btrfs] > <4>[27034.990700] [] ? _raw_spin_unlock+0x2b/0x40 > <4>[27034.996552] [] ? do_futex+0xa45/0xbb0 > <4>[27035.001885] [] ? fget_light+0x3c/0x130 > <4>[27035.007302] [] do_vfs_ioctl+0x96/0x560 > <4>[27035.012720] [] ? fget_light+0x9e/0x130 > <4>[27035.018137] [] ? fget_light+0x3c/0x130 > <4>[27035.023556] [] SyS_ioctl+0x91/0xb0 > <4>[27035.028628] [] ? trace_hardirqs_on_thunk+0x3a/0x3f > <4>[27035.035089] [] system_call_fastpath+0x16/0x1b > > This is presumably some breakage in the freeze locking dance that goes on > with async commits (btrfs_commit_transaction_async caller takes the freeze > semaphore, do_async_commit releases it), but it's not obvious to me what > broke yet. Unless this rings any bells for anyone, I'll go ahead and > bisect. > > Thanks! > sage > -- > 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 >