Re: [bug report] dm: 'tried to init an initialized object' error triggered during device creation

[Yu Kuai]

Hi,

在 2025/07/31 9:28, Hou Tao 写道:
> cc +linux-block
>
> The disk->queue_kobj is initialized in add_disk() and is uninitialized
> in del_disk(). And it seems that blk_unregister_queue() in del_disk()
> doesn't uninitialize the queue_kobj completely, because it doesn't
> expect the queue_kobj will be added again. I think the right place to
> fix the problem is blk_unregister_queue(). How about just memset the
> queue_kobj as zero after deleting the queue_kobj in blk_unregister_queue() ?

I think it's better to move kobject_init to allocate disk:

1) alloc disk, kobject_init
2) register q, kobject_add
3) unregister q, kobject_del
4) free disk, kobject_put

With this, it's safe to add the kobject again.

Thanks,
Kuai