BTRFS error (device loop0): failed to run delayed ref for logical 5410816 num_bytes 434176 type 178 action 1 ref_mod 1: -2 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -2) WARNING: fs/btrfs/extent-tree.c:2247 at btrfs_run_delayed_refs+0x30b/0x3b0 fs/btrfs/extent-tree.c:2247, CPU#0: kworker/u4:3/42 Modules linked in: CPU: 0 UID: 0 PID: 42 Comm: kworker/u4:3 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/0x3b0 fs/btrfs/extent-tree.c:2247 Code: 85 e4 75 07 e8 f3 63 dd fd eb 7a e8 fc 6f c2 fd 84 c0 74 20 e8 e3 63 dd fd eb 6a e8 dc 63 dd fd 48 8d 3d 15 86 51 0c 44 89 fe <67> 48 0f b9 3a e9 0b ff ff ff e8 b3 83 c1 07 41 89 c4 31 ff 89 c6 RSP: 0018:ffffc900004477b8 EFLAGS: 00010293 RAX: ffffffff83e856c4 RBX: ffff888012c11608 RCX: ffff88801f8fa500 RDX: 0000000000000000 RSI: 00000000fffffffe RDI: ffffffff9039dce0 RBP: 0000000000000000 R08: ffff88801f8fa500 R09: 0000000000000003 R10: 00000000fffffffb R11: 0000000000000000 R12: ffff888040ba0001 R13: ffff8880124a8000 R14: dffffc0000000000 R15: 00000000fffffffe FS: 0000000000000000(0000) GS:ffff88808c888000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa5b6435ff8 CR3: 0000000011c68000 CR4: 0000000000352ef0 Call Trace: flush_space+0x574/0xe20 fs/btrfs/space-info.c:-1 do_async_reclaim_metadata_space+0x3fc/0x960 fs/btrfs/space-info.c:1211 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1278 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 85 e4 test %esp,%esp 2: 75 07 jne 0xb 4: e8 f3 63 dd fd call 0xfddd63fc 9: eb 7a jmp 0x85 b: e8 fc 6f c2 fd call 0xfdc2700c 10: 84 c0 test %al,%al 12: 74 20 je 0x34 14: e8 e3 63 dd fd call 0xfddd63fc 19: eb 6a jmp 0x85 1b: e8 dc 63 dd fd call 0xfddd63fc 20: 48 8d 3d 15 86 51 0c lea 0xc518615(%rip),%rdi # 0xc51863c 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 b3 83 c1 07 call 0x7c183ec 39: 41 89 c4 mov %eax,%r12d 3c: 31 ff xor %edi,%edi 3e: 89 c6 mov %eax,%esi