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Commit b62c21b7 authored by Mike Snitzer's avatar Mike Snitzer Committed by Jens Axboe
Browse files

blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk 



Add a variant of blk_mq_init_queue that allows a previously allocated
queue to be initialized.  blk_mq_init_allocated_queue models
blk_init_allocated_queue -- which was also created for DM's use.

DM's approach to device creation requires a placeholder request_queue be
allocated for use with alloc_dev() but the decision about what type of
request_queue will be ultimately created is deferred until all component
devices referenced in the DM table are processed to determine the table
type (request-based, blk-mq request-based, or bio-based).

Also, because of DM's late finalization of the request_queue type
the call to blk_mq_register_disk() doesn't happen during alloc_dev().
Must export blk_mq_register_disk() so that DM can backfill the 'mq' dir
once the blk-mq queue is fully allocated.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Reviewed-by: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 64f9b683

block/blk-mq-sysfs.c

+1 −0
Original line number Diff line number Diff line
@@ -436,6 +436,7 @@ int blk_mq_register_disk(struct gendisk *disk) 


	return 0;

}

EXPORT_SYMBOL_GPL(blk_mq_register_disk);



void blk_mq_sysfs_unregister(struct request_queue *q)

{

block/blk-mq.c

+20 −10
Original line number Diff line number Diff line
@@ -1890,10 +1890,26 @@ void blk_mq_release(struct request_queue *q) 
}



struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)

{

	struct request_queue *uninit_q, *q;



	uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);

	if (!uninit_q)

		return ERR_PTR(-ENOMEM);



	q = blk_mq_init_allocated_queue(set, uninit_q);

	if (IS_ERR(q))

		blk_cleanup_queue(uninit_q);



	return q;

}

EXPORT_SYMBOL(blk_mq_init_queue);



struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,

						  struct request_queue *q)

{

	struct blk_mq_hw_ctx **hctxs;

	struct blk_mq_ctx __percpu *ctx;

	struct request_queue *q;

	unsigned int *map;

	int i;
@@ -1928,17 +1944,13 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) 
		hctxs[i]->queue_num = i;

	}



	q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);

	if (!q)

		goto err_hctxs;



	/*

	 * Init percpu_ref in atomic mode so that it's faster to shutdown.

	 * See blk_register_queue() for details.

	 */

	if (percpu_ref_init(&q->mq_usage_counter, blk_mq_usage_counter_release,

			    PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))

		goto err_mq_usage;

		goto err_hctxs;



	setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);

	blk_queue_rq_timeout(q, 30000);
@@ -1981,7 +1993,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) 
	blk_mq_init_cpu_queues(q, set->nr_hw_queues);



	if (blk_mq_init_hw_queues(q, set))

		goto err_mq_usage;

		goto err_hctxs;



	mutex_lock(&all_q_mutex);

	list_add_tail(&q->all_q_node, &all_q_list);
@@ -1993,8 +2005,6 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) 


	return q;



err_mq_usage:

	blk_cleanup_queue(q);

err_hctxs:

	kfree(map);

	for (i = 0; i < set->nr_hw_queues; i++) {
@@ -2009,7 +2019,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) 
	free_percpu(ctx);

	return ERR_PTR(-ENOMEM);

}

EXPORT_SYMBOL(blk_mq_init_queue);

EXPORT_SYMBOL(blk_mq_init_allocated_queue);



void blk_mq_free_queue(struct request_queue *q)

{

include/linux/blk-mq.h

+2 −0
Original line number Diff line number Diff line
@@ -164,6 +164,8 @@ 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_allocated_queue(struct blk_mq_tag_set *set,

						  struct request_queue *q);

void blk_mq_finish_init(struct request_queue *q);

int blk_mq_register_disk(struct gendisk *);

void blk_mq_unregister_disk(struct gendisk *);