------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/block-group.c:4182 at do_chunk_alloc fs/btrfs/block-group.c:4182 [inline], CPU#0: kworker/u4:6/158
WARNING: fs/btrfs/block-group.c:4182 at btrfs_chunk_alloc+0x101d/0x15e0 fs/btrfs/block-group.c:4423, CPU#0: kworker/u4:6/158
Modules linked in:
CPU: 0 UID: 0 PID: 158 Comm: kworker/u4:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
RIP: 0010:do_chunk_alloc fs/btrfs/block-group.c:4182 [inline]
RIP: 0010:btrfs_chunk_alloc+0x101f/0x15e0 fs/btrfs/block-group.c:4423
Code: 97 4f ae fd e9 6d 01 00 00 e8 8d 62 93 fd 84 c0 74 22 e8 84 4f ae fd e9 5a 01 00 00 e8 7a 4f ae fd 48 8d 3d 63 d2 25 0c 89 de <67> 48 0f b9 3a e9 b3 fc ff ff e8 02 19 a3 07 41 89 c6 31 ff 89 c6
RSP: 0018:ffffc9000168f6d0 EFLAGS: 00010293
RAX: ffffffff84179176 RBX: ffffffffffffffe4 RCX: ffff888032f02500
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff903d63e0
RBP: 0000000000000000 R08: ffff888032f02500 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff11002683a16
R13: ffff888023e0e7b8 R14: ffff8880409e8001 R15: ffff88804502d000
FS:  0000000000000000(0000) GS:ffff88808c809000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9dcf257f90 CR3: 000000001f3f2000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 flush_space+0x3fb/0xe20 fs/btrfs/space-info.c:908
 do_async_reclaim_metadata_space+0x3fc/0x960 fs/btrfs/space-info.c:1211
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1278
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	97                   	xchg   %eax,%edi
   1:	4f ae                	rex.WRXB scas %es:(%rdi),%al
   3:	fd                   	std
   4:	e9 6d 01 00 00       	jmp    0x176
   9:	e8 8d 62 93 fd       	call   0xfd93629b
   e:	84 c0                	test   %al,%al
  10:	74 22                	je     0x34
  12:	e8 84 4f ae fd       	call   0xfdae4f9b
  17:	e9 5a 01 00 00       	jmp    0x176
  1c:	e8 7a 4f ae fd       	call   0xfdae4f9b
  21:	48 8d 3d 63 d2 25 0c 	lea    0xc25d263(%rip),%rdi        # 0xc25d28b
  28:	89 de                	mov    %ebx,%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 b3 fc ff ff       	jmp    0xfffffce7
  34:	e8 02 19 a3 07       	call   0x7a3193b
  39:	41 89 c6             	mov    %eax,%r14d
  3c:	31 ff                	xor    %edi,%edi
  3e:	89 c6                	mov    %eax,%esi