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.