------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/block-group.c:4097 at do_chunk_alloc fs/btrfs/block-group.c:4097 [inline], CPU#0: kworker/u4:6/151
WARNING: fs/btrfs/block-group.c:4097 at btrfs_chunk_alloc+0x101d/0x15e0 fs/btrfs/block-group.c:4338, CPU#0: kworker/u4:6/151
Modules linked in:
CPU: 0 UID: 0 PID: 151 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:4097 [inline]
RIP: 0010:btrfs_chunk_alloc+0x101f/0x15e0 fs/btrfs/block-group.c:4338
Code: c7 e6 b2 fd e9 6d 01 00 00 e8 5d eb 97 fd 84 c0 74 22 e8 b4 e6 b2 fd e9 5a 01 00 00 e8 aa e6 b2 fd 48 8d 3d 43 63 08 0c 89 de <67> 48 0f b9 3a e9 b3 fc ff ff e8 f2 26 9b 07 41 89 c6 31 ff 89 c6
RSP: 0018:ffffc9000172e600 EFLAGS: 00010293
RAX: ffffffff8412b0f6 RBX: ffffffffffffffe4 RCX: ffff888032ad0000
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff901b1440
RBP: 0000000000000000 R08: ffff888032ad0000 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff1100861c116
R13: ffff88801185e2b0 R14: ffff888011ad0001 R15: ffff888012a0f800
FS:  0000000000000000(0000) GS:ffff88808ca62000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd3ff1f320 CR3: 000000001f0be000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 find_free_extent_update_loop fs/btrfs/extent-tree.c:4306 [inline]
 find_free_extent+0x52bf/0x5f60 fs/btrfs/extent-tree.c:4727
 btrfs_reserve_extent+0x344/0x830 fs/btrfs/extent-tree.c:4821
 cow_one_range fs/btrfs/inode.c:1320 [inline]
 cow_file_range+0x588/0x1310 fs/btrfs/inode.c:1522
 writepage_delalloc+0x1270/0x1ee0 fs/btrfs/extent_io.c:1526
 extent_writepage fs/btrfs/extent_io.c:1893 [inline]
 extent_write_cache_pages fs/btrfs/extent_io.c:2580 [inline]
 btrfs_writepages+0x14df/0x2440 fs/btrfs/extent_io.c:2713
 do_writepages+0x32e/0x550 mm/page-writeback.c:2554
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_flush_nr+0x20e/0x360 mm/filemap.c:462
 start_delalloc_inodes+0x517/0xb00 fs/btrfs/inode.c:8892
 btrfs_start_delalloc_roots+0x561/0x7f0 fs/btrfs/inode.c:8952
 shrink_delalloc fs/btrfs/space-info.c:761 [inline]
 flush_space+0x6b5/0xd80 fs/btrfs/space-info.c:871
 do_async_reclaim_metadata_space+0x3fc/0x960 fs/btrfs/space-info.c:1187
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1254
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	e6 b2                	out    %al,$0xb2
   2:	fd                   	std
   3:	e9 6d 01 00 00       	jmp    0x175
   8:	e8 5d eb 97 fd       	call   0xfd97eb6a
   d:	84 c0                	test   %al,%al
   f:	74 22                	je     0x33
  11:	e8 b4 e6 b2 fd       	call   0xfdb2e6ca
  16:	e9 5a 01 00 00       	jmp    0x175
  1b:	e8 aa e6 b2 fd       	call   0xfdb2e6ca
  20:	48 8d 3d 43 63 08 0c 	lea    0xc086343(%rip),%rdi        # 0xc08636a
  27:	89 de                	mov    %ebx,%esi
* 29:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2e:	e9 b3 fc ff ff       	jmp    0xfffffce6
  33:	e8 f2 26 9b 07       	call   0x79b272a
  38:	41 89 c6             	mov    %eax,%r14d
  3b:	31 ff                	xor    %edi,%edi
  3d:	89 c6                	mov    %eax,%esi