Re: btrfs_destroy_inode WARN_ON.

[Josef Bacik]

On 03/25/2016 04:25 AM, Markus Trippelsdorf wrote:
> On 2016.03.24 at 18:54 -0400, Dave Jones wrote:
> > Just hit this on a tree from earlier this morning, v4.5-11140 or so.
> >
> > WARNING: CPU: 2 PID: 32570 at fs/btrfs/inode.c:9261 btrfs_destroy_inode+0x389/0x3f0 [btrfs]
> > CPU: 2 PID: 32570 Comm: rm Not tainted 4.5.0-think+ #14
> >   ffffffffc039baf9 00000000ef721ef0 ffff88025966fc08 ffffffff8957bcdb
> >   0000000000000000 0000000000000000 ffff88025966fc50 ffffffff890b41f1
> >   ffff88045d918040 0000242d4eed6048 ffff88024eed6048 ffff88024eed6048
> > Call Trace:
> >   [<ffffffffc039baf9>] ? btrfs_destroy_inode+0x389/0x3f0 [btrfs]
> >   [<ffffffff8957bcdb>] dump_stack+0x68/0x9d
> >   [<ffffffff890b41f1>] __warn+0x111/0x130
> >   [<ffffffff890b43fd>] warn_slowpath_null+0x1d/0x20
> >   [<ffffffffc039baf9>] btrfs_destroy_inode+0x389/0x3f0 [btrfs]
> >   [<ffffffff89352307>] destroy_inode+0x67/0x90
> >   [<ffffffff893524e7>] evict+0x1b7/0x240
> >   [<ffffffff893529be>] iput+0x3ae/0x4e0
> >   [<ffffffff8934c93e>] ? dput+0x20e/0x460
> >   [<ffffffff8933ee26>] do_unlinkat+0x256/0x440
> >   [<ffffffff8933ebd0>] ? do_rmdir+0x350/0x350
> >   [<ffffffff890031e7>] ? syscall_trace_enter_phase1+0x87/0x260
> >   [<ffffffff89003160>] ? enter_from_user_mode+0x50/0x50
> >   [<ffffffff8913c3b5>] ? __lock_is_held+0x25/0xd0
> >   [<ffffffff891411f2>] ? mark_held_locks+0x22/0xc0
> >   [<ffffffff890034ed>] ? syscall_trace_enter_phase2+0x12d/0x3d0
> >   [<ffffffff893400b0>] ? SyS_rmdir+0x20/0x20
> >   [<ffffffff893400cb>] SyS_unlinkat+0x1b/0x30
> >   [<ffffffff89003ac4>] do_syscall_64+0xf4/0x240
> >   [<ffffffff89d520da>] entry_SYSCALL64_slow_path+0x25/0x25
> > ---[ end trace a48ce4e6a1b5e409 ]---
> >
> >
> > That's WARN_ON(BTRFS_I(inode)->csum_bytes);
> >
> > *maybe* it's a bad disk, but there's no indication in dmesg of anything awry.
> > Spinning rust on SATA, nothing special.
>
> Same thing here:
>
> Mar 24 10:37:27 x4 kernel: ------------[ cut here ]------------
> Mar 24 10:37:27 x4 kernel: WARNING: CPU: 3 PID: 11838 at fs/btrfs/inode.c:9261 btrfs_destroy_inode+0x22b/0x2a0
> Mar 24 10:37:27 x4 kernel: CPU: 3 PID: 11838 Comm: rm Not tainted 4.5.0-11787-ga24e3d414e59-dirty #64
> Mar 24 10:37:27 x4 kernel: Hardware name: System manufacturer System Product Name/M4A78T-E, BIOS 3503    04/13/2011
> Mar 24 10:37:27 x4 kernel: 0000000000000000 ffffffff813c0d1a ffffffff81b8bb84 ffffffff812ffd0b
> Mar 24 10:37:27 x4 kernel: ffffffff81099a9a 0000000000000000 ffff880149b86088 ffff88021585f000
> Mar 24 10:37:27 x4 kernel: ffffffff812ffd0b 0000000000000000 ffff88005f526000 0000000000000000
> Mar 24 10:37:27 x4 kernel: Call Trace:
> Mar 24 10:37:27 x4 kernel: [<ffffffff813c0d1a>] ? dump_stack+0x46/0x6c
> Mar 24 10:37:27 x4 kernel: [<ffffffff812ffd0b>] ? btrfs_destroy_inode+0x22b/0x2a0
> Mar 24 10:37:27 x4 kernel: [<ffffffff81099a9a>] ? warn_slowpath_null+0x5a/0xe0
> Mar 24 10:37:27 x4 kernel: [<ffffffff812ffd0b>] ? btrfs_destroy_inode+0x22b/0x2a0
> Mar 24 10:37:27 x4 kernel: [<ffffffff811ab31c>] ? do_unlinkat+0x13c/0x3e0
> Mar 24 10:37:27 x4 kernel: [<ffffffff810930db>] ? entry_SYSCALL_64_fastpath+0x13/0x8f
> Mar 24 10:37:27 x4 kernel: ---[ end trace e9bae5be848e7a9e ]---

I saw this running some xfstests on our internal kernels but haven't 
been able to reproduce it on my latest enospc work (which is obviously 
perfect).  What were you doing when you tripped this?  I'd like to see 
if I actually did fix it or if I still need to run it down.  Thanks,

Josef