[PATCH V2 08/13] block: export __blk_mq_unfreeze_queue

[Christoph Hellwig]

On Sat, Jan 22, 2022 at 07:10:49PM +0800, Ming Lei wrote:
> blk_mq_unfreeze_queue() is used by scsi when releasing disk, so not
> necessary to unfreeze into percpu mode, then the following
> blk_cleanup_queue doesn't need to freeze queue from percpu mode, and
> the implied RCU grace period may be avoided.
> 
> Meantime move clearing QUEUE_FLAG_INIT_DONE into this API, so that
> when one disk is added, ->q_usage_counter can be switched to percpu
> mode again.

Independ of the use case (which I'll need to review in the next patches),
exporting lowlevel-helpers like this just seems like a bad idea.

If we have a use case add a wrapper that sets the force_atomic flag
and document and export that, please.