------------[ cut here ]------------
ret == -ENOENT
WARNING: fs/btrfs/extent-tree.c:3418 at __btrfs_free_extent+0x1732/0x4570 fs/btrfs/extent-tree.c:3418, CPU#0: syz.0.0/5345
Modules linked in:
CPU: 0 UID: 0 PID: 5345 Comm: syz.0.0 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
RIP: 0010:__btrfs_free_extent+0x1732/0x4570 fs/btrfs/extent-tree.c:3418
Code: 03 00 00 e8 90 e6 da fd 4c 8b 7c 24 10 48 8b 5c 24 18 48 8b 44 24 30 4d 89 e5 49 bc 00 00 00 00 00 fc ff df e9 4e 0d 00 00 90 <0f> 0b 90 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 28 80 3c 01 00
RSP: 0018:ffffc9000ddb5d20 EFLAGS: 00010246
RAX: 0000000000000002 RBX: ffff8880448d5d50 RCX: 0000000000000005
RDX: ffffffff83eacd9e RSI: ffffffff8ef69400 RDI: 00000000fffffffe
RBP: ffffc9000ddb5ed0 R08: ffff88803660ca80 R09: 0000000000000002
R10: 00000000fffffffe R11: 0000000000000000 R12: 00000000fffffffe
R13: 00000000fffffffe R14: ffff888044f8c8f0 R15: 000000000051a000
FS:  00007f23f568a6c0(0000) GS:ffff88808c891000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23f55456a0 CR3: 0000000038701000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1824 [inline]
 run_one_delayed_ref fs/btrfs/extent-tree.c:1851 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:2058 [inline]
 __btrfs_run_delayed_refs+0x1870/0x4710 fs/btrfs/extent-tree.c:2133
 btrfs_run_delayed_refs+0xec/0x3b0 fs/btrfs/extent-tree.c:2245
 btrfs_start_dirty_block_groups+0xd4c/0x10b0 fs/btrfs/block-group.c:3681
 btrfs_commit_transaction+0x375/0x2fc0 fs/btrfs/transaction.c:2291
 btrfs_sync_file+0xdf0/0x1200 fs/btrfs/file.c:1822
 generic_write_sync include/linux/fs.h:2654 [inline]
 btrfs_do_write_iter+0x6a3/0x840 fs/btrfs/file.c:1473
 __kernel_write_iter+0x41e/0x880 fs/read_write.c:621
 __kernel_write+0x106/0x170 fs/read_write.c:641
 __dump_emit fs/coredump.c:1226 [inline]
 dump_emit+0x8e9/0xab0 fs/coredump.c:1264
 elf_core_dump+0x2bef/0x3ad0 fs/binfmt_elf.c:2061
 coredump_write+0x12b0/0x19d0 fs/coredump.c:1053
 do_coredump fs/coredump.c:1132 [inline]
 vfs_coredump+0x3807/0x4530 fs/coredump.c:1206
 get_signal+0x1107/0x1330 kernel/signal.c:3022
 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 ret_from_fork+0x593/0xb70 arch/x86/kernel/process.c:167
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>