------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/block-group.c:4012 at do_chunk_alloc fs/btrfs/block-group.c:4012 [inline], CPU#0: kworker/u4:17/3124
WARNING: fs/btrfs/block-group.c:4012 at btrfs_chunk_alloc+0x101d/0x15d0 fs/btrfs/block-group.c:4253, CPU#0: kworker/u4:17/3124
Modules linked in:
CPU: 0 UID: 0 PID: 3124 Comm: kworker/u4:17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: writeback wb_workfn (flush-btrfs-1)
RIP: 0010:do_chunk_alloc fs/btrfs/block-group.c:4012 [inline]
RIP: 0010:btrfs_chunk_alloc+0x101f/0x15d0 fs/btrfs/block-group.c:4253
Code: 47 84 c9 fd e9 6d 01 00 00 e8 ad 79 af fd 84 c0 74 22 e8 34 84 c9 fd e9 5a 01 00 00 e8 2a 84 c9 fd 48 8d 3d 83 1c 94 0b 89 de <67> 48 0f b9 3a e9 b3 fc ff ff e8 42 23 64 07 41 89 c6 31 ff 89 c6
RSP: 0018:ffffc9000bf6e578 EFLAGS: 00010293
RAX: ffffffff83f78336 RBX: ffffffffffffffe4 RCX: ffff88801f678000
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff8f8b9fc0
RBP: 0000000000000000 R08: ffff88801f678000 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff11002214e16
R13: ffff888011c1f628 R14: ffff88804260c001 R15: ffff888030f3a800
FS:  0000000000000000(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 0000000035b0b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 find_free_extent_update_loop fs/btrfs/extent-tree.c:4199 [inline]
 find_free_extent+0x45b7/0x5d00 fs/btrfs/extent-tree.c:4611
 btrfs_reserve_extent+0x2c7/0x780 fs/btrfs/extent-tree.c:4705
 cow_file_range+0x4d1/0x10a0 fs/btrfs/inode.c:1366
 writepage_delalloc+0xf06/0x1a60 fs/btrfs/extent_io.c:1501
 extent_writepage fs/btrfs/extent_io.c:1864 [inline]
 extent_write_cache_pages fs/btrfs/extent_io.c:2552 [inline]
 btrfs_writepages+0x12fd/0x21e0 fs/btrfs/extent_io.c:2685
 do_writepages+0x32e/0x550 mm/page-writeback.c:2598
 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
 wb_check_start_all fs/fs-writeback.c:2344 [inline]
 wb_do_writeback fs/fs-writeback.c:2370 [inline]
 wb_workfn+0x8ee/0xed0 fs/fs-writeback.c:2403
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 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:	47 84 c9             	rex.RXB test %r9b,%r9b
   3:	fd                   	std
   4:	e9 6d 01 00 00       	jmp    0x176
   9:	e8 ad 79 af fd       	call   0xfdaf79bb
   e:	84 c0                	test   %al,%al
  10:	74 22                	je     0x34
  12:	e8 34 84 c9 fd       	call   0xfdc9844b
  17:	e9 5a 01 00 00       	jmp    0x176
  1c:	e8 2a 84 c9 fd       	call   0xfdc9844b
  21:	48 8d 3d 83 1c 94 0b 	lea    0xb941c83(%rip),%rdi        # 0xb941cab
  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 42 23 64 07       	call   0x764237b
  39:	41 89 c6             	mov    %eax,%r14d
  3c:	31 ff                	xor    %edi,%edi
  3e:	89 c6                	mov    %eax,%esi