tree 4eb5617cb983d279305e7b9f7e65cf61f0175d2a
parent 080ff3511450fd73948697fef34a3cc382675b59
author Ming Lei <ming.lei@canonical.com> 1417606684 +0800
committer Jens Axboe <axboe@fb.com> 1418099828 -0700

blk-mq: prevent unmapped hw queue from being scheduled

When one hardware queue has no mapped software queues, it
shouldn't have been scheduled. Otherwise WARNING or OOPS
can triggered.

blk_mq_hw_queue_mapped() helper is introduce for fixing
the problem.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>