Re: [PATCH 1/4] loop: Use worker per cgroup instead of kworker

[Hillf Danton <hdanton@xxxxxxxx>]

On Mon, 20 Apr 2020 18:39:29 -0400 Dan Schatzberg wrote:
> 
> @@ -1140,8 +1215,17 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
>  	blk_mq_freeze_queue(lo->lo_queue);
>  
>  	spin_lock_irq(&lo->lo_lock);
> +	destroy_workqueue(lo->workqueue);

Destruct it out of atomic context.

>  	lo->lo_backing_file = NULL;
> +	list_for_each_entry_safe(worker, pos, &lo->idle_worker_list,
> +				idle_list) {
> +		list_del(&worker->idle_list);
> +		rb_erase(&worker->rb_node, &lo->worker_tree);
> +		css_put(worker->css);
> +		kfree(worker);
> +	}
>  	spin_unlock_irq(&lo->lo_lock);