Re: bio linked list corruption.

From: Dave Jones
Date: Tue Oct 25 2016 - 20:28:12 EST


On Mon, Oct 24, 2016 at 09:42:39AM -0400, Chris Mason wrote:

> > > Well crud, we're back to wondering if this is Btrfs or the stack
> > > corruption. Since the pagevecs are on the stack and this is a new
> > > crash, my guess is you'll be able to trigger it on xfs/ext4 too. But we
> > > should make sure.
> >
> > Here's an interesting one from today, pointing the finger at xattrs again.
> >
> >
> > [69943.450108] Oops: 0003 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> > [69943.454452] CPU: 1 PID: 21558 Comm: trinity-c60 Not tainted 4.9.0-rc1-think+ #11
> > [69943.463510] task: ffff8804f8dd3740 task.stack: ffffc9000b108000
> > [69943.468077] RIP: 0010:[<ffffffff810c3f6b>]
>
> Was this btrfs?

I already told you elsewhere, but for benefit of everyone else, yes, it was.

At Chris' behest, I gave ext4 some more air-time with this workload.
It ran for 1 day 6 hrs without incident before I got bored and tried
something else. I threw XFS on the test partition, restarted the test,
and got the warnings below across two reboots.

DaveC: Do these look like real problems, or is this more "looks like
random memory corruption" ? It's been a while since I did some stress
testing on XFS, so these might not be new..



XFS: Assertion failed: oldlen > newlen, file: fs/xfs/libxfs/xfs_bmap.c, line: 2938
------------[ cut here ]------------
kernel BUG at fs/xfs/xfs_message.c:113!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 6227 Comm: trinity-c9 Not tainted 4.9.0-rc1-think+ #6
task: ffff8804f4658040 task.stack: ffff88050568c000
RIP: 0010:[<ffffffffa02d3e2b>]
[<ffffffffa02d3e2b>] assfail+0x1b/0x20 [xfs]
RSP: 0000:ffff88050568f9e8 EFLAGS: 00010282
RAX: 00000000ffffffea RBX: 0000000000000046 RCX: 0000000000000001
RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffffa02fe34d
RBP: ffff88050568f9e8 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: f000000000000000 R12: ffff88050568fb44
R13: 00000000000000f3 R14: ffff8804f292bf88 R15: 000ffffffffe0046
FS: 00007fe2ddfdfb40(0000) GS:ffff88050a000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe2dbabd000 CR3: 00000004f461f000 CR4: 00000000001406e0
Stack:
ffff88050568fa88 ffffffffa027ccee fffffffffffffff9 ffff8804f16fd8b0
0000000000003ffa 0000000000000032 ffff8804f292bf40 0000000000004976
000ffffffffe0008 00000000000004fd ffff880400000000 0000000000005107
Call Trace:
[<ffffffffa027ccee>] xfs_bmap_add_extent_hole_delay+0x54e/0x620 [xfs]
[<ffffffffa027f2d4>] xfs_bmapi_reserve_delalloc+0x2b4/0x400 [xfs]
[<ffffffffa02cadd7>] xfs_file_iomap_begin_delay.isra.12+0x247/0x3c0 [xfs]
[<ffffffffa02cb0d1>] xfs_file_iomap_begin+0x181/0x270 [xfs]
[<ffffffffa02ca13e>] ? xfs_file_iomap_end+0x9e/0xe0 [xfs]
[<ffffffff8122e573>] iomap_apply+0x53/0x100
[<ffffffff8122df10>] ? iomap_write_end+0x70/0x70
[<ffffffff8122e68b>] iomap_file_buffered_write+0x6b/0x90
[<ffffffff8122df10>] ? iomap_write_end+0x70/0x70
[<ffffffffa02c1dd8>] xfs_file_buffered_aio_write+0xe8/0x1d0 [xfs]
[<ffffffff810c3b7f>] ? __lock_acquire.isra.32+0x1cf/0x8c0
[<ffffffffa02c1f45>] xfs_file_write_iter+0x85/0x120 [xfs]
[<ffffffff811c8c98>] do_iter_readv_writev+0xa8/0x100
[<ffffffff811c9622>] do_readv_writev+0x172/0x210
[<ffffffffa02c1ec0>] ? xfs_file_buffered_aio_write+0x1d0/0x1d0 [xfs]
[<ffffffff811e9794>] ? __fdget_pos+0x44/0x50
[<ffffffff8178b2f2>] ? mutex_lock_nested+0x272/0x3f0
[<ffffffff811e9794>] ? __fdget_pos+0x44/0x50
[<ffffffff811e9794>] ? __fdget_pos+0x44/0x50
[<ffffffff811c98ea>] vfs_writev+0x3a/0x50
[<ffffffff811c9950>] do_writev+0x50/0xd0
[<ffffffff811ca9fb>] SyS_writev+0xb/0x10
[<ffffffff8100255c>] do_syscall_64+0x5c/0x170
[<ffffffff8178ff4b>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 48 c7 c7 65 e3 2f a0 e8 74 37 da e0 5d c3 66 90 55 48 89 f1 41 89 d0 48 c7 c6 18 93 30 a0 48 89 fa 48 89 e5 31 ff e8 65 fa ff ff <0f> 0b 0f 1f 00 55 48 63 f6 49 89 f9 41 b8 01 00 00 00 48 89 e5
RIP
[<ffffffffa02d3e2b>] assfail+0x1b/0x20 [xfs]
RSP <ffff88050568f9e8>



XFS: Assertion failed: tp->t_blk_res_used <= tp->t_blk_res, file: fs/xfs/xfs_trans.c, line: 309
kernel BUG at fs/xfs/xfs_message.c:113!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 0 PID: 7309 Comm: kworker/u8:1 Not tainted 4.9.0-rc1-think+ #11
Workqueue: writeback wb_workfn
(flush-8:0)
task: ffff88025eb98040 task.stack: ffffc9000a914000
RIP: 0010:[<ffffffffa0571e2b>]
[<ffffffffa0571e2b>] assfail+0x1b/0x20 [xfs]
RSP: 0018:ffffc9000a917410 EFLAGS: 00010282
RAX: 00000000ffffffea RBX: ffff8804538d22b8 RCX: 0000000000000001
RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffffa059c34d
RBP: ffffc9000a917410 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: f000000000000000 R12: ffffffffffffffff
R13: ffff88047c765698 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff880507800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000004c56e7000 CR4: 00000000001406f0
DR0: 00007fec5e3c9000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
ffffc9000a917438 ffffffffa057abe1 ffffc9000a917510 ffffc9000a917510
ffffc9000a917510 ffffc9000a917460 ffffffffa0548eff ffffc9000a917510
0000000000000001 ffffc9000a917510 ffffc9000a917480 ffffffffa050aa3d
Call Trace:
[<ffffffffa057abe1>] xfs_trans_mod_sb+0x241/0x280 [xfs]
[<ffffffffa0548eff>] xfs_ag_resv_alloc_extent+0x4f/0xc0 [xfs]
[<ffffffffa050aa3d>] xfs_alloc_ag_vextent+0x23d/0x300 [xfs]
[<ffffffffa050bb1b>] xfs_alloc_vextent+0x5fb/0x6d0 [xfs]
[<ffffffffa051c1b4>] xfs_bmap_btalloc+0x304/0x8e0 [xfs]
[<ffffffffa054648e>] ? xfs_iext_bno_to_ext+0xee/0x170 [xfs]
[<ffffffffa051c8db>] xfs_bmap_alloc+0x2b/0x40 [xfs]
[<ffffffffa051dc30>] xfs_bmapi_write+0x640/0x1210 [xfs]
[<ffffffffa0569326>] xfs_iomap_write_allocate+0x166/0x350 [xfs]
[<ffffffffa05540b0>] xfs_map_blocks+0x1b0/0x260 [xfs]
[<ffffffffa0554beb>] xfs_do_writepage+0x23b/0x730 [xfs]
[<ffffffff81159ef8>] ? clear_page_dirty_for_io+0x128/0x210
[<ffffffff81159e71>] ? clear_page_dirty_for_io+0xa1/0x210
[<ffffffff8115a1b6>] write_cache_pages+0x1d6/0x4a0
[<ffffffffa05549b0>] ? xfs_aops_discard_page+0x140/0x140 [xfs]
[<ffffffffa0554419>] xfs_vm_writepages+0x59/0x80 [xfs]
[<ffffffff8115af6c>] do_writepages+0x1c/0x30
[<ffffffff811f6d33>] __writeback_single_inode+0x33/0x180
[<ffffffff811f7528>] writeback_sb_inodes+0x2a8/0x5b0
[<ffffffff811f78bd>] __writeback_inodes_wb+0x8d/0xc0
[<ffffffff811f7b73>] wb_writeback+0x1e3/0x1f0
[<ffffffff811f80b2>] wb_workfn+0xd2/0x280
[<ffffffff81090875>] process_one_work+0x1d5/0x490
[<ffffffff81090815>] ? process_one_work+0x175/0x490
[<ffffffff81090b79>] worker_thread+0x49/0x490
[<ffffffff81090b30>] ? process_one_work+0x490/0x490
[<ffffffff81090b30>] ? process_one_work+0x490/0x490
[<ffffffff81095cee>] kthread+0xee/0x110
[<ffffffff81095c00>] ? kthread_park+0x60/0x60
[<ffffffff81790bd2>] ret_from_fork+0x22/0x30
Code: 48 c7 c7 65 c3 59 a0 e8 c4 5c b0 e0 5d c3 66 90 55 48 89 f1 41 89 d0 48 c7 c6 18 73 5a a0 48 89 fa 48 89 e5 31 ff e8 65 fa ff ff <0f> 0b 0f 1f 00 55 48 63 f6 49 89 f9 41 b8 01 00 00 00 48 89 e5
RIP
[<ffffffffa0571e2b>] assfail+0x1b/0x20 [xfs]
RSP <ffffc9000a917410>