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>

diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 0979213..5d0f93c 100644 (file)
--- 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);

diff --cc block/blk-mq-tag.c
Simple merge

diff --cc block/blk-mq-tag.h
Simple merge

diff --cc block/blk-mq.c
Simple merge

diff --cc block/blk-mq.h
Simple merge

diff --cc drivers/block/null_blk.c
Simple merge

diff --cc drivers/block/virtio_blk.c
Simple merge

diff --cc include/linux/blk-mq.h
Simple merge