On Thu, Jul 14, 2022 at 06:55:28AM -0700, Christoph Hellwig wrote: > On Thu, Jul 14, 2022 at 09:37:10PM +0800, Ming Lei wrote: > > It is actually one big problem of 6f8191fdf41d ("block: simplify disk shutdown") > > since blk_put_queue() can't do what blk_cleanup_queue() did. > > > > Anywhere using blk_put_queue() to release blk-mq queue before adding > > disk has the same issue. > > And the reason why blk_put_queue can't do is seems to be mostly because > queues don't hold a reference on the tag set (and tag_sets don't have Exactly. > a reference at all). Which has caused us a bunch of issues before, so > let me see if I can fix that properly. I guess it is hard to fix, not get any idea yet. Originally we stop to referring tagset after blk_cleanup_queue(), but now you are trying to kill blk_cleanup_queue()... thanks, Ming