------------[ cut here ]------------
WARNING: CPU: 1 PID: 31533 at fs/btrfs/volumes.c:1172 close_fs_devices+0x71d/0x7b0 fs/btrfs/volumes.c:1172
Modules linked in:
CPU: 1 PID: 31533 Comm: syz-executor.2 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x71d/0x7b0 fs/btrfs/volumes.c:1172
Code: c4 38 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 ab 51 40 fe 0f 0b e9 6f f9 ff ff e8 9f 51 40 fe 0f 0b e9 3c ff ff ff e8 93 51 40 fe <0f> 0b e9 69 ff ff ff 48 c7 c1 a4 54 ee 8c 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90018667708 EFLAGS: 00010246
RAX: ffffffff8334b61d RBX: ffffffffffffffff RCX: 0000000000040000
RDX: ffffc9000ce1a000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff88801b519108 R08: ffffffff8334b57f R09: ffffed10057b6827
R10: ffffed10057b6827 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88802bdb4060 R14: 1ffff110057b680c R15: 1ffff110057b680a
FS:  00007f1e9df8e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556fe69adc18 CR3: 000000001dc37000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 btrfs_close_devices+0x8c/0x400 fs/btrfs/volumes.c:1184
 open_ctree+0x890/0x3b3b fs/btrfs/disk-io.c:3432
 btrfs_fill_super fs/btrfs/super.c:1316 [inline]
 btrfs_mount_root+0x9b8/0xb60 fs/btrfs/super.c:1672
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x88/0x270 fs/super.c:1549
 fc_mount fs/namespace.c:978 [inline]
 vfs_kern_mount+0xc9/0x160 fs/namespace.c:1008
 btrfs_mount+0x345/0xa80 fs/btrfs/super.c:1732
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x88/0x270 fs/super.c:1549
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x17b4/0x2a20 fs/namespace.c:3205
 do_mount fs/namespace.c:3218 [inline]
 __do_sys_mount fs/namespace.c:3426 [inline]
 __se_sys_mount+0x28c/0x320 fs/namespace.c:3403
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x46090a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f1e9df8da88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1e9df8db20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f1e9df8dae0
RBP: 00007f1e9df8dae0 R08: 00007f1e9df8db20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020000080