BTRFS error (device loop0): failed to run delayed ref for logical 8904704 num_bytes 4096 type 178 action 1 ref_mod 1: -28
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BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/extent-tree.c:2162 at btrfs_run_delayed_refs+0x30b/0x3a0 fs/btrfs/extent-tree.c:2162, CPU#0: kworker/u4:12/1818
Modules linked in:
CPU: 0 UID: 0 PID: 1818 Comm: kworker/u4:12 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:btrfs_run_delayed_refs+0x30e/0x3a0 fs/btrfs/extent-tree.c:2162
Code: 85 e4 75 07 e8 03 ba ee fd eb 7a e8 5c 68 d4 fd 84 c0 74 20 e8 f3 b9 ee fd eb 6a e8 ec b9 ee fd 48 8d 3d f5 cc 03 0c 44 89 fe <67> 48 0f b9 3a e9 0b ff ff ff e8 e3 95 a6 07 41 89 c4 31 ff 89 c6
RSP: 0018:ffffc9000267f818 EFLAGS: 00010293
RAX: ffffffff83d3ee94 RBX: ffff888012785000 RCX: ffff8880337bc980
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff8fd7bb90
RBP: 0000000000000000 R08: ffff8880337bc980 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: ffff88801cbec001
R13: ffff888000bf5000 R14: dffffc0000000000 R15: 00000000ffffffe4
FS:  0000000000000000(0000) GS:ffff88808cf1d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f90400483c8 CR3: 0000000011f56000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 flush_space+0x28d/0xd30 fs/btrfs/space-info.c:-1
 do_async_reclaim_metadata_space+0x11e/0x350 fs/btrfs/space-info.c:1189
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1256
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
----------------
Code disassembly (best guess):
   0:	85 e4                	test   %esp,%esp
   2:	75 07                	jne    0xb
   4:	e8 03 ba ee fd       	call   0xfdeeba0c
   9:	eb 7a                	jmp    0x85
   b:	e8 5c 68 d4 fd       	call   0xfdd4686c
  10:	84 c0                	test   %al,%al
  12:	74 20                	je     0x34
  14:	e8 f3 b9 ee fd       	call   0xfdeeba0c
  19:	eb 6a                	jmp    0x85
  1b:	e8 ec b9 ee fd       	call   0xfdeeba0c
  20:	48 8d 3d f5 cc 03 0c 	lea    0xc03ccf5(%rip),%rdi        # 0xc03cd1c
  27:	44 89 fe             	mov    %r15d,%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 0b ff ff ff       	jmp    0xffffff3f
  34:	e8 e3 95 a6 07       	call   0x7a6961c
  39:	41 89 c4             	mov    %eax,%r12d
  3c:	31 ff                	xor    %edi,%edi
  3e:	89 c6                	mov    %eax,%esi