BTRFS error (device loop0): allocation failed flags 2, wanted 4096 tree-log 0, relocation: 0 BTRFS info (device loop0): space_info SYSTEM (sub-group id 0) has -98304 free, is not full BTRFS info (device loop0): space_info total=4194304, used=4096, pinned=0, reserved=0, may_use=98304, readonly=4190208 zone_unusable=0 BTRFS info (device loop0): global_block_rsv: size 1441792 reserved 1441792 BTRFS info (device loop0): trans_block_rsv: size 0 reserved 0 BTRFS info (device loop0): chunk_block_rsv: size 98304 reserved 94208 BTRFS info (device loop0): delayed_block_rsv: size 294912 reserved 294912 BTRFS info (device loop0): delayed_refs_rsv: size 851968 reserved 786432 BTRFS info (device loop0): block group 1048576 has 4194304 bytes, 4096 used 0 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (4190208 bytes available) [readonly] 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): 4190208 bytes available across all block groups ------------[ 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/u4:10/1081 WARNING: fs/btrfs/block-group.c:4012 at btrfs_chunk_alloc+0x101d/0x15d0 fs/btrfs/block-group.c:4253, CPU#0: kworker/u4:10/1081 Modules linked in: CPU: 0 UID: 0 PID: 1081 Comm: kworker/u4:10 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:do_chunk_alloc fs/btrfs/block-group.c:4012 [inline] RIP: 0010:btrfs_chunk_alloc+0x101f/0x15d0 fs/btrfs/block-group.c:4253 Code: f7 84 c9 fd e9 6d 01 00 00 e8 1d 7c af fd 84 c0 74 22 e8 e4 84 c9 fd e9 5a 01 00 00 e8 da 84 c9 fd 48 8d 3d 03 1b 94 0b 89 de <67> 48 0f b9 3a e9 b3 fc ff ff e8 e2 15 64 07 41 89 c6 31 ff 89 c6 RSP: 0018:ffffc90003147730 EFLAGS: 00010293 RAX: ffffffff83f78076 RBX: ffffffffffffffe4 RCX: ffff888035d40000 RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff8f8b9b80 RBP: 0000000000000000 R08: ffff888035d40000 R09: 0000000000000003 R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff110022e9016 R13: ffff88804880ce40 R14: ffff88801247c001 R15: ffff8880356c0000 FS: 0000000000000000(0000) GS:ffff88808d416000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f01ecfe9e9c CR3: 00000000416b7000 CR4: 0000000000352ef0 Call Trace: flush_space+0x355/0xd20 fs/btrfs/space-info.c:894 do_async_reclaim_metadata_space+0x11e/0x350 fs/btrfs/space-info.c:1185 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1252 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 ---------------- Code disassembly (best guess): 0: f7 84 c9 fd e9 6d 01 testl $0x1de80000,0x16de9fd(%rcx,%rcx,8) 7: 00 00 e8 1d b: 7c af jl 0xffffffbc d: fd std e: 84 c0 test %al,%al 10: 74 22 je 0x34 12: e8 e4 84 c9 fd call 0xfdc984fb 17: e9 5a 01 00 00 jmp 0x176 1c: e8 da 84 c9 fd call 0xfdc984fb 21: 48 8d 3d 03 1b 94 0b lea 0xb941b03(%rip),%rdi # 0xb941b2b 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 e2 15 64 07 call 0x764161b 39: 41 89 c6 mov %eax,%r14d 3c: 31 ff xor %edi,%edi 3e: 89 c6 mov %eax,%esi