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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 <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
hifive-unleashed-5.1
Mike Snitzer 2015-03-12 23:56:02 -04:00 committed by Jens Axboe
parent 64f9b683b6
commit b62c21b71f
3 changed files with 23 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
block/blk-mq-sysfs.c
View File

@ -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)
{

30
block/blk-mq.c
View File

@ -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)
{

2
include/linux/blk-mq.h
View File

@ -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 *);