blk-mq: Export blk_mq_freeze_queue_wait

Drivers can start a freeze, so this provides a way to wait for frozen.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Keith Busch 2017-03-01 14:22:10 -05:00 committed by Jens Axboe
parent 6a8a215465
commit 6bae363ee3
2 changed files with 3 additions and 1 deletions

View File

@ -75,10 +75,11 @@ void blk_mq_freeze_queue_start(struct request_queue *q)
}
EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
static void blk_mq_freeze_queue_wait(struct request_queue *q)
void blk_mq_freeze_queue_wait(struct request_queue *q)
{
wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
}
EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
/*
* Guarantee no request is in use, so we can change any data structure of

View File

@ -245,6 +245,7 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_unfreeze_queue(struct request_queue *q);
void blk_mq_freeze_queue_start(struct request_queue *q);
void blk_mq_freeze_queue_wait(struct request_queue *q);
int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
int blk_mq_map_queues(struct blk_mq_tag_set *set);