From b62c21b71f08b7a4bfd025616ff1da2913a82904 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 12 Mar 2015 23:56:02 -0400 Subject: [PATCH] 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: Mike Snitzer Reviewed-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq-sysfs.c | 1 + block/blk-mq.c | 30 ++++++++++++++++++++---------- include/linux/blk-mq.h | 2 ++ 3 files changed, 23 insertions(+), 10 deletions(-) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 1630a20d5dcf..b79685e06b70 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -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) { diff --git a/block/blk-mq.c b/block/blk-mq.c index b7b8933ec241..3000121840bb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -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 @@ err_percpu: 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) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 7aec86127335..9a75c88e8908 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -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 *);