Re: [PATCH] block: remove per-disk debugfs files in blk_unregister_queue

Christoph Hellwig
2022-05-24T12:01:41Z

On Tue, May 24, 2022 at 07:47:03PM +0800, Ming Lei wrote:
> Not look into details yet, but as one blk-mq debugfs user, I don't like
> the idea, since I often see io hang issue when calling
> blk_mq_freeze_queue_wait(), and blk-mq debugfs is very helpful for
> investigating this kind of issue.
>
> But now blk-mq debugfs is gone with this patch __before__ draining IO in
> del_gendisk, and it becomes not useful as before.

This is the way hot it is set up, so in doubt I want it to be torn down
synchronously. There might be a way to move the teardown later, but
that will require a very careful audit.