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overlay: ./file1 is not a directory
overlay: ./file2 is not a directory
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WARNING: CPU: 0 PID: 5326 at fs/btrfs/extent-tree.c:836 lookup_inline_extent_backref+0x12c7/0x17f0 fs/btrfs/extent-tree.c:836
Modules linked in:
CPU: 0 UID: 0 PID: 5326 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~bpo12+1 04/01/2014
RIP: 0010:lookup_inline_extent_backref+0x12c7/0x17f0 fs/btrfs/extent-tree.c:836
Code: 05 ee 34 a5 0e 48 3b 84 24 e0 01 00 00 0f 85 8e 04 00 00 89 d8 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 4b a9 81 07 cc 90 <0f> 0b 90 48 8b 44 24 78 42 80 3c 30 00 74 0a 48 8b 7c 24 20 e8 30
RSP: 0018:ffffc9000d48eca0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000002
RDX: ffff88801f700000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000d48eec8 R08: 0000000000000000 R09: 1ffffd40002881a8
R10: dffffc0000000000 R11: fffff940002881a9 R12: 1ffff1100a1f3976
R13: 00000000000000b6 R14: dffffc0000000000 R15: ffff8880355a8000
FS:  00007f7b670586c0(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000041c74000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 insert_inline_extent_backref+0xa8/0x2f0 fs/btrfs/extent-tree.c:1205
 __btrfs_inc_extent_ref+0x263/0x9e0 fs/btrfs/extent-tree.c:1503
 run_one_delayed_ref fs/btrfs/extent-tree.c:-1 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:1972 [inline]
 __btrfs_run_delayed_refs+0xebd/0x4130 fs/btrfs/extent-tree.c:2047
 btrfs_run_delayed_refs+0x191/0x3b0 fs/btrfs/extent-tree.c:2159
 qgroup_account_snapshot+0xab/0x4a0 fs/btrfs/transaction.c:1571
 create_pending_snapshot+0xead/0x3280 fs/btrfs/transaction.c:1854
 create_pending_snapshots+0x17c/0x1c0 fs/btrfs/transaction.c:1924
 btrfs_commit_transaction+0xeea/0x3950 fs/btrfs/transaction.c:2412
 create_snapshot+0x6bc/0xba0 fs/btrfs/ioctl.c:782
 btrfs_mksubvol+0x545/0x6d0 fs/btrfs/ioctl.c:934
 btrfs_mksnapshot+0xab/0xf0 fs/btrfs/ioctl.c:978
 __btrfs_ioctl_snap_create+0x520/0x730 fs/btrfs/ioctl.c:1242
 btrfs_ioctl_snap_create_v2+0x1f8/0x3b0 fs/btrfs/ioctl.c:1322
 btrfs_ioctl+0xa62/0xd00 fs/btrfs/ioctl.c:-1
 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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b6618f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7b67058038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7b663e6090 RCX: 00007f7b6618f749
RDX: 0000200000001480 RSI: 0000000050009417 RDI: 0000000000000007
RBP: 00007f7b66213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b663e6128 R14: 00007f7b663e6090 R15: 00007fff5e1e9308
 </TASK>