blk-mq: provide helper for setting up an SQ queue and tag set

This pattern is repeated throughout all the blk-mq conversions.
Provide a basic helper to get it done.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c2ecd64a2403d422f9c47badfef3f5350eb1a154..dcf10e39995a668d9f9af77ebb0edaf700aef2bb 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2507,6 +2507,39 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 }
 EXPORT_SYMBOL(blk_mq_init_queue);
 
+/*
+ * Helper for setting up a queue with mq ops, given queue depth, and
+ * the passed in mq ops flags.
+ */
+struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
+                                          const struct blk_mq_ops *ops,
+                                          unsigned int queue_depth,
+                                          unsigned int set_flags)
+{
+       struct request_queue *q;
+       int ret;
+
+       memset(set, 0, sizeof(*set));
+       set->ops = ops;
+       set->nr_hw_queues = 1;
+       set->queue_depth = queue_depth;
+       set->numa_node = NUMA_NO_NODE;
+       set->flags = set_flags;
+
+       ret = blk_mq_alloc_tag_set(set);
+       if (ret)
+               return ERR_PTR(ret);
+
+       q = blk_mq_init_queue(set);
+       if (IS_ERR(q)) {
+               blk_mq_free_tag_set(set);
+               return q;
+       }
+
+       return q;
+}
+EXPORT_SYMBOL(blk_mq_init_sq_queue);
+
 static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
 {
        int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 1da59c16f6377e6f77f5cd1f774a00d374757a57..2286dc12c6bcb63ffc131cb7a94481dcff781a2b 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -203,6 +203,10 @@ enum {
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
                                                  struct request_queue *q);
+struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set,
+                                               const struct blk_mq_ops *ops,
+                                               unsigned int queue_depth,
+                                               unsigned int set_flags);
 int blk_mq_register_dev(struct device *, struct request_queue *);
 void blk_mq_unregister_dev(struct device *, struct request_queue *);