Re: WARNING: CPU: 2 PID: 32343 at fs/btrfs/inode.c:8693 btrfs_destroy_inode+0x278/0x2a0()

From: Markus Trippelsdorf <markus@trippelsdorf.de>
To: Filipe David Manana <fdmanana@gmail.com>
Cc: Chris Mason <clm@fb.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: WARNING: CPU: 2 PID: 32343 at fs/btrfs/inode.c:8693 btrfs_destroy_inode+0x278/0x2a0()
Date: Mon, 2 Mar 2015 14:29:33 +0100	[thread overview]
Message-ID: <20150302132933.GA347@x4> (raw)
In-Reply-To: <CAL3q7H6LPNt4zqrt9DFigJhc=gaNRew5VrKQGaP5o_h-5X1eRw@mail.gmail.com>

On 2015.03.02 at 12:07 +0000, Filipe David Manana wrote:
> >> [83159.038708] ------------[ cut here ]------------
> >> [83159.038716] WARNING: CPU: 2 PID: 32343 at fs/btrfs/inode.c:8693 btrfs_destroy_inode+0x278/0x2a0()
> >> [83159.038718] CPU: 2 PID: 32343 Comm: rm Tainted: G        W       4.0.0-rc1-dirty #104
> >> [83159.038719] Hardware name: System manufacturer System Product Name/M4A78T-E, BIOS 3503    04/13/2011
> >> [83159.038720]  0000000000000000 ffffffff8199990f ffffffff8168d723 0000000000000000
> >> [83159.038722]  ffffffff8106d2d2 0000000000000000 ffff88005756edf0 ffff880215805800
> >> [83159.038723]  ffff880169477eb8 ffff88005756edf0 ffffffff8121bab8 ffff880100675000
> >> [83159.038725] Call Trace:
> >> [83159.038728]  [<ffffffff8168d723>] ? dump_stack+0x40/0x50
> >> [83159.038731]  [<ffffffff8106d2d2>] ? warn_slowpath_common+0x72/0xc0
> >> [83159.038732]  [<ffffffff8121bab8>] ? btrfs_destroy_inode+0x278/0x2a0
> >> [83159.038735]  [<ffffffff8111f747>] ? do_unlinkat+0x1a7/0x2e0
> >> [83159.038737]  [<ffffffff81083974>] ? task_work_run+0xb4/0x100
> >> [83159.038740]  [<ffffffff8103b9a9>] ? do_notify_resume+0x69/0x80
> >> [83159.038742]  [<ffffffff81694092>] ? system_call_fastpath+0x12/0x17
> >> [83159.038743] ---[ end trace 3b7c45c6e46fe8dd ]---
> >> [83159.038744] ------------[ cut here ]------------
> >> [83159.038745] WARNING: CPU: 2 PID: 32343 at fs/btrfs/inode.c:8694 btrfs_destroy_inode+0x1f2/0x2a0()
> >> [83159.038746] CPU: 2 PID: 32343 Comm: rm Tainted: G        W       4.0.0-rc1-dirty #104
> >> [83159.038747] Hardware name: System manufacturer System Product Name/M4A78T-E, BIOS 3503    04/13/2011
> >> [83159.038747]  0000000000000000 ffffffff8199990f ffffffff8168d723 0000000000000000
> >> [83159.038749]  ffffffff8106d2d2 0000000000000000 ffff88005756edf0 ffff880215805800
> >> [83159.038750]  ffff880169477eb8 ffff88005756edf0 ffffffff8121ba32 ffff880100675000
> >> [83159.038751] Call Trace:
> >> [83159.038753]  [<ffffffff8168d723>] ? dump_stack+0x40/0x50
> >> [83159.038754]  [<ffffffff8106d2d2>] ? warn_slowpath_common+0x72/0xc0
> >> [83159.038755]  [<ffffffff8121ba32>] ? btrfs_destroy_inode+0x1f2/0x2a0
> >> [83159.038757]  [<ffffffff8111f747>] ? do_unlinkat+0x1a7/0x2e0
> >> [83159.038758]  [<ffffffff81083974>] ? task_work_run+0xb4/0x100
> >> [83159.038760]  [<ffffffff8103b9a9>] ? do_notify_resume+0x69/0x80
> >> [83159.038761]  [<ffffffff81694092>] ? system_call_fastpath+0x12/0x17
> >> [83159.038762] ---[ end trace 3b7c45c6e46fe8de ]---
> >
> > Unfortunately the issue isn't 100% reproducible, so I unfortunately
> > cannot bisect.
> 
> You probably don't need to bisect. The warning is related to the
> outstanding_extents counter being != 0:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/fs/btrfs/inode.c?id=refs/tags/v4.0-rc1#n8693
> 
> The only change in 4.0 that changes updates to that counter is:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3e05bde8c3c2dd761da4d52944a087907955a53c
> 
> So that's likely the change you would find with a bisect.

OK, thank you. I will revert the commit and see if it fixes the issue.

-- 
Markus