[PATCH 4/6] blk-mq: avoid to map CPU into stale hw queue

[Christoph Hellwig]

On Tue, Dec 12, 2017 at 07:02:30PM +0800, Ming Lei wrote:
> blk_mq_pci_map_queues() may not map one CPU into any hw queue, but its
> previous map isn't cleared yet, and may point to one stale hw queue
> index.
> 
> This patch fixes the following issue by clearing the mapping table before
> setting it up in blk_mq_pci_map_queues().

This needs to be done in the caller intead of the transport specific
queue map helpers.