block: use {alloc|free}_sched data methods

The previous patch introduced ->alloc_sched_data and
->free_sched_data methods. This patch builds upon that
by now using these methods during elevator switch and
nr_hw_queue update.

It's also ensured that scheduler-specific data is
allocated and freed through the new callbacks outside
of the ->freeze_lock and ->elevator_lock locking contexts,
thereby preventing any dependency on pcpu_alloc_mutex.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 1 deletions

diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index 4e1b86e85a8a..02c40a72e959 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -26,7 +26,9 @@ void blk_mq_sched_free_rqs(struct request_queue *q);
 struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set,
 		unsigned int nr_hw_queues, unsigned int nr_requests);
 int blk_mq_alloc_sched_res(struct request_queue *q,
-		struct elevator_resources *res, unsigned int nr_hw_queues);
+		struct elevator_type *type,
+		struct elevator_resources *res,
+		unsigned int nr_hw_queues);
 int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl,
 		struct blk_mq_tag_set *set, unsigned int nr_hw_queues);
 int blk_mq_alloc_sched_ctx_batch(struct xarray *elv_tbl,
@@ -35,6 +37,7 @@ void blk_mq_free_sched_ctx_batch(struct xarray *elv_tbl);
 void blk_mq_free_sched_tags(struct elevator_tags *et,
 		struct blk_mq_tag_set *set);
 void blk_mq_free_sched_res(struct elevator_resources *res,
+		struct elevator_type *type,
 		struct blk_mq_tag_set *set);
 void blk_mq_free_sched_res_batch(struct xarray *et_table,
 		struct blk_mq_tag_set *set);