blk-mq: split out tag initialization, support shared tags

Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue.  A single blk_mq_tag_set structure can be shared by multiple
queues.

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

Modular export of blk_mq_{alloc,free}_tagset added by me.

Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 097921329619..5d0f93cf358c 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -80,17 +80,17 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues)
         return 0;
 }
 
-unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg)
+unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
 {
         unsigned int *map;
 
         /* If cpus are offline, map them to first hctx */
         map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL,
-                                reg->numa_node);
+                                set->numa_node);
         if (!map)
                 return NULL;
 
-        if (!blk_mq_update_queue_map(map, reg->nr_hw_queues))
+        if (!blk_mq_update_queue_map(map, set->nr_hw_queues))
                 return map;
 
         kfree(map);