On Wed, May 25, 2016 at 11:23:27PM -0700, Ming Lin wrote:

From: Ming Lin <redacted>

blk_mq_init_queue() calls blk_mq_init_allocated_queue(), but q->mq_ops
was not cleared when blk_mq_init_allocated_queue() fails.
Then blk_cleanup_queue() calls blk_mq_free_queue() which will crash because:
- q->all_q_node is not added to all_q_list yet
- q->tag_set is NULL
- hctx was not setup yet or already freed

Fixed it by clearing q->mq_ops on error path.

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>