BTRFS info (device loop0): balance: start -d -m
BTRFS info (device loop0): relocating block group 6881280 flags data|metadata
BTRFS info (device loop0): relocating block group 5242880 flags data|metadata
BTRFS info (device loop0): found 9 extents, stage: move data extents
------------[ cut here ]------------
ret
WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x1436/0x1a70 fs/btrfs/extent-tree.c:879, CPU#0: syz.0.0/5327
Modules linked in:
CPU: 0 UID: 0 PID: 5327 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:lookup_inline_extent_backref+0x1436/0x1a70 fs/btrfs/extent-tree.c:879
Code: 8f 05 00 00 89 d8 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 a5 49 db fd bb fe ff ff ff e9 05 fd ff ff 90 <0f> 0b 90 48 8b 84 24 88 00 00 00 48 b9 00 00 00 00 00 fc ff df 80
RSP: 0018:ffffc9000f7669c0 EFLAGS: 00010202
RAX: ffffffff83ea6114 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff8880003a8000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000f766be8 R08: 0000000000000000 R09: 1ffffd4000099ab0
R10: dffffc0000000000 R11: fffff94000099ab1 R12: ffff8880122c4000
R13: 0000000000828000 R14: ffff888042246a90 R15: 0000000000000009
FS:  00007ff5a1ff56c0(0000) GS:ffff88808c885000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 00000000128ff000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 insert_inline_extent_backref+0xa8/0x300 fs/btrfs/extent-tree.c:1248
 __btrfs_inc_extent_ref+0x271/0xa00 fs/btrfs/extent-tree.c:1547
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1819 [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+0xfdd/0x4710 fs/btrfs/extent-tree.c:2133
 btrfs_run_delayed_refs+0x191/0x3b0 fs/btrfs/extent-tree.c:2245
 qgroup_account_snapshot fs/btrfs/transaction.c:1607 [inline]
 create_pending_snapshot+0x128a/0x37e0 fs/btrfs/transaction.c:1879
 create_pending_snapshots+0x17c/0x1c0 fs/btrfs/transaction.c:1965
 btrfs_commit_transaction+0xf78/0x30e0 fs/btrfs/transaction.c:2463
 prepare_to_relocate+0x39f/0x490 fs/btrfs/relocation.c:3476
 relocate_block_group+0x149/0xe70 fs/btrfs/relocation.c:3501
 do_nonremap_reloc+0xa8/0x5b0 fs/btrfs/relocation.c:5268
 btrfs_relocate_block_group+0x7e6/0xc40 fs/btrfs/relocation.c:5434
 btrfs_relocate_chunk+0x115/0x820 fs/btrfs/volumes.c:3598
 __btrfs_balance+0x1db0/0x2ae0 fs/btrfs/volumes.c:4509
 btrfs_balance+0xaf3/0x11b0 fs/btrfs/volumes.c:4896
 btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3453
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff5a5b9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff5a1ff4fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff5a5e16090 RCX: 00007ff5a5b9cdd9
RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 0000000000000006
RBP: 00007ff5a5c32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff5a5e16128 R14: 00007ff5a5e16090 R15: 00007ffd918ab3a8
 </TASK>