------------[ cut here ]------------
WARNING: CPU: 0 PID: 29422 at fs/btrfs/volumes.c:1168 close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168
Modules linked in:
CPU: 0 PID: 29422 Comm: syz-executor.4 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168
Code: e8 93 81 2f fe 85 db 0f 85 07 f9 ff ff e8 46 7a 2f fe 0f 0b e9 fb f8 ff ff e8 3a 7a 2f fe 0f 0b e9 e2 fd ff ff e8 2e 7a 2f fe <0f> 0b e9 19 fe ff ff 48 c7 c7 ac 98 6c 8d e8 cb aa 75 fe e9 bb f8
RSP: 0018:ffffc900158a77c8 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc90011a7d000
RDX: 0000000000040000 RSI: ffffffff834610c2 RDI: 0000000000000003
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffff8880211e013b
R10: ffffffff83460ed9 R11: 0000000000000000 R12: ffff8880211e0138
R13: 0000000000000000 R14: ffff88801e012508 R15: ffff8880211e0050
FS:  00007f45bf903700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c02238c080 CR3: 000000007f76e000 CR4: 0000000000350ee0
Call Trace:
 btrfs_close_devices+0x8e/0x4b0 fs/btrfs/volumes.c:1180
 close_ctree+0x752/0x795 fs/btrfs/disk-io.c:4433
 btrfs_fill_super fs/btrfs/super.c:1393 [inline]
 btrfs_mount_root.cold+0xb0/0x165 fs/btrfs/super.c:1737
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 fc_mount fs/namespace.c:993 [inline]
 vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1023
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1010
 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1797
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x132a/0x1fa0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount fs/namespace.c:3433 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3433
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467b0a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f45bf902fa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000467b0a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f45bf903000
RBP: 00007f45bf903040 R08: 00007f45bf903040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f45bf903000 R15: 0000000020016800