block: add a blk_mq_init_queue_data helper

This allows a driver to pass a queuedata member before ->init_hctx is
called.  null_blk currently open codes this logic, but I'd rather have
it in the core to ease future maintainance.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 745ec59..216bf62 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2724,13 +2724,15 @@ void blk_mq_release(struct request_queue *q)
        blk_mq_sysfs_deinit(q);
 }
 
-struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
+struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
+               void *queuedata)
 {
        struct request_queue *uninit_q, *q;
 
        uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
        if (!uninit_q)
                return ERR_PTR(-ENOMEM);
+       uninit_q->queuedata = queuedata;
 
        /*
         * Initialize the queue without an elevator. device_add_disk() will do
@@ -2742,6 +2744,12 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 
        return q;
 }
+EXPORT_SYMBOL_GPL(blk_mq_init_queue_data);
+
+struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
+{
+       return blk_mq_init_queue_data(set, NULL);
+}
 EXPORT_SYMBOL(blk_mq_init_queue);
 
 /*

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 31344d5..f389d7c 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -412,6 +412,8 @@ enum {
                << BLK_MQ_F_ALLOC_POLICY_START_BIT)
 
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
+struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
+               void *queuedata);
 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
                                                  struct request_queue *q,
                                                  bool elevator_init);