BTRFS error (device loop0): allocation failed flags 4, wanted 4096 tree-log 0, relocation: 0
BTRFS info (device loop0): space_info DATA+METADATA (sub-group id 0) has -1441792 free, is full
BTRFS info (device loop0): space_info total=9895936, used=61440, pinned=16384, reserved=8257536, may_use=1441792, readonly=1560576 zone_unusable=0
BTRFS info (device loop0): global_block_rsv: size 1441792 reserved 1437696
BTRFS info (device loop0): trans_block_rsv: size 0 reserved 0
BTRFS info (device loop0): chunk_block_rsv: size 0 reserved 0
BTRFS info (device loop0): delayed_block_rsv: size 0 reserved 0
BTRFS info (device loop0): delayed_refs_rsv: size 0 reserved 0
BTRFS info (device loop0): block group 5242880 has 1638400 bytes, 61440 used 16384 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (1560576 bytes available) [readonly]
BTRFS critical (device loop0): entry offset 5242880, bytes 12288, bitmap no
BTRFS critical (device loop0): entry offset 5259264, bytes 8192, bitmap no
BTRFS critical (device loop0): entry offset 5271552, bytes 20480, bitmap no
BTRFS critical (device loop0): entry offset 5320704, bytes 40960, bitmap no
BTRFS critical (device loop0): entry offset 5365760, bytes 4096, bitmap no
BTRFS critical (device loop0): entry offset 5378048, bytes 36864, bitmap no
BTRFS critical (device loop0): entry offset 5443584, bytes 1437696, bitmap no
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 0 free space entries at or bigger than 4096 bytes
BTRFS info (device loop0): block group 8519680 has 8257536 bytes, 0 used 0 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (8257536 bytes available) 
BTRFS critical (device loop0): entry offset 8519680, bytes 8257536, bitmap no
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 1 free space entries at or bigger than 4096 bytes
BTRFS info (device loop0): 9818112 bytes available across all block groups
BTRFS warning (device loop0): Skipping commit of aborted transaction.
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 0 PID: 13 at fs/btrfs/transaction.c:2020 cleanup_transaction fs/btrfs/transaction.c:2020 [inline]
WARNING: CPU: 0 PID: 13 at fs/btrfs/transaction.c:2020 btrfs_commit_transaction+0x2f67/0x3950 fs/btrfs/transaction.c:2611
Modules linked in:
CPU: 0 UID: 0 PID: 13 Comm: kworker/u4:1 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: events_unbound btrfs_async_reclaim_metadata_space
RIP: 0010:cleanup_transaction fs/btrfs/transaction.c:2020 [inline]
RIP: 0010:btrfs_commit_transaction+0x2f67/0x3950 fs/btrfs/transaction.c:2611
Code: ef f7 d7 fd 84 c0 74 2b e8 36 bc f1 fd eb 73 e8 2f bc f1 fd 90 48 c7 c7 80 79 ae 8b 8b 5c 24 18 89 de e8 6c c8 b4 fd 89 d9 90 <0f> 0b 90 90 e9 1a 01 00 00 e8 7b 31 7a 07 89 c3 31 ff 89 c6 e8 40
RSP: 0018:ffffc900001f74e0 EFLAGS: 00010246
RAX: 3f9d940b95200400 RBX: 00000000ffffffe4 RCX: 00000000ffffffe4
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc900001f7810 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bba684 R12: ffff88801ab212b8
R13: ffff888051bf0000 R14: ffff888051bf0000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88808d730000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2bec26b6b0 CR3: 000000001158e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 flush_space+0x48b/0xcd0 fs/btrfs/space-info.c:888
 do_async_reclaim_metadata_space+0x144/0x390 fs/btrfs/space-info.c:1158
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1226
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>