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

Markus Trippelsdorf
2015-03-03T14:13:56Z

On 2015.03.02 at 14:29 +0100, Markus Trippelsdorf wrote:
> 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.

No. Reverting 3e05bde8c3 does _not_ fix the issue. It still happens.

--
Markus