blk-mq: clear q->mq_ops if init fail

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.

Signed-off-by: Ming Lin <ming.l@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7df9c9263b2125a86bceb05c1d357ded38051c70..29cbc1b5fbdba0ee89874c662ab441b2a817e177 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2020,7 +2020,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 
        q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
        if (!q->queue_ctx)
-               return ERR_PTR(-ENOMEM);
+               goto err_exit;
 
        q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
                                                GFP_KERNEL, set->numa_node);
@@ -2084,6 +2084,8 @@ err_map:
        kfree(q->queue_hw_ctx);
 err_percpu:
        free_percpu(q->queue_ctx);
+err_exit:
+       q->mq_ops = NULL;
        return ERR_PTR(-ENOMEM);
 }
 EXPORT_SYMBOL(blk_mq_init_allocated_queue);