From: Dan Mick <dan.mick@inktank.com>
To: Sage Weil <sage@inktank.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: bad unlock balance in btrfs_commit_transaction_async
Date: Tue, 27 Aug 2013 17:56:59 -0700 [thread overview]
Message-ID: <521D4ADB.8010804@inktank.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1308221731350.2577@cobra.newdream.net>
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] [<ffffffffa0148fd8>] 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] [<ffffffffa0148fd8>] ? btrfs_commit_transaction_async+0x1c8/0x2c0 [btrfs]
> <4>[27034.937790] [<ffffffff81642d85>] dump_stack+0x46/0x58
> <4>[27034.942951] [<ffffffff810ab89e>] print_unlock_imbalance_bug+0xfe/0x110
> <4>[27034.949599] [<ffffffffa0148fd8>] ? btrfs_commit_transaction_async+0x1c8/0x2c0 [btrfs]
> <4>[27034.957552] [<ffffffff810aeafe>] lock_release+0x15e/0x220
> <4>[27034.963069] [<ffffffffa0148fff>] btrfs_commit_transaction_async+0x1ef/0x2c0 [btrfs]
> <4>[27034.970850] [<ffffffff810af6f5>] ? trace_hardirqs_on_caller+0x105/0x1d0
> <4>[27034.977587] [<ffffffffa0177907>] btrfs_ioctl_start_sync+0x47/0xc0 [btrfs]
> <4>[27034.984499] [<ffffffffa017c575>] btrfs_ioctl+0xe55/0x1af0 [btrfs]
> <4>[27034.990700] [<ffffffff8164ab2b>] ? _raw_spin_unlock+0x2b/0x40
> <4>[27034.996552] [<ffffffff810b40b5>] ? do_futex+0xa45/0xbb0
> <4>[27035.001885] [<ffffffff8119cf0c>] ? fget_light+0x3c/0x130
> <4>[27035.007302] [<ffffffff811922a6>] do_vfs_ioctl+0x96/0x560
> <4>[27035.012720] [<ffffffff8119cf6e>] ? fget_light+0x9e/0x130
> <4>[27035.018137] [<ffffffff8119cf0c>] ? fget_light+0x3c/0x130
> <4>[27035.023556] [<ffffffff81192801>] SyS_ioctl+0x91/0xb0
> <4>[27035.028628] [<ffffffff813338fe>] ? trace_hardirqs_on_thunk+0x3a/0x3f
> <4>[27035.035089] [<ffffffff81653782>] 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
> --
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>
next prev parent reply other threads:[~2013-08-28 0:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-23 0:40 bad unlock balance in btrfs_commit_transaction_async Sage Weil
2013-08-28 0:56 ` Dan Mick [this message]
2013-08-28 1:33 ` Yan, Zheng
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