syzbot

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kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 0 PID: 21541 at fs/kernfs/dir.c:1545 kernfs_remove_by_name_ns+0xb1/0x100 fs/kernfs/dir.c:1544
Modules linked in:
CPU: 0 PID: 21541 Comm: syz-executor.2 Not tainted 5.15.133-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
RIP: 0010:kernfs_remove_by_name_ns+0xb1/0x100 fs/kernfs/dir.c:1544
Code: ff 03 48 89 df e8 1f eb ff ff 48 89 df e8 27 a6 ff ff 31 db eb 27 e8 4e 45 84 ff 48 c7 c7 80 7c 99 8a 4c 89 fe e8 cf 04 50 ff <0f> 0b bb fe ff ff ff eb 16 e8 31 45 84 ff bb fe ff ff ff 48 c7 c7
RSP: 0018:ffffc900134ff9c0 EFLAGS: 00010246
RAX: dc2053435b85a000 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc90003a15000 RSI: 0000000000008604 RDI: 0000000000008605
RBP: dffffc0000000000 R08: ffffffff816658bc R09: ffffed10173467a8
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8ceea968
R13: ffffffff8ceea968 R14: 0000000000000000 R15: ffffffff8ad6e740
FS:  00007f2dd5cef6c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020083030 CR3: 00000000a4e17000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kernfs_remove_by_name include/linux/kernfs.h:598 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xfa/0x2a0 fs/sysfs/group.c:289
 sysfs_remove_groups+0x50/0xa0 fs/sysfs/group.c:313
 __kobject_del+0x84/0x310 lib/kobject.c:619
 kobject_del+0x41/0x60 lib/kobject.c:651
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:183 [inline]
 blk_mq_sysfs_unregister+0x1bf/0x290 block/blk-mq-sysfs.c:309
 __blk_mq_update_nr_hw_queues block/blk-mq.c:3764 [inline]
 blk_mq_update_nr_hw_queues+0x60e/0xe80 block/blk-mq.c:3804
 nbd_start_device+0x163/0xc20 drivers/block/nbd.c:1301
 nbd_start_device_ioctl drivers/block/nbd.c:1351 [inline]
 __nbd_ioctl drivers/block/nbd.c:1427 [inline]
 nbd_ioctl+0x4da/0xe10 drivers/block/nbd.c:1467
 blkdev_ioctl+0x333/0x6b0 block/ioctl.c:603
 block_ioctl+0xb1/0xf0 block/fops.c:493
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f2dd776dae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2dd5cef0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2dd788cf80 RCX: 00007f2dd776dae9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006
RBP: 00007f2dd5cef120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f2dd788cf80 R15: 00007fffb27fc5c8
 </TASK>