Commit f8e111c8 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: don't call freeze queue in elevator_switch() and elevator_disable() 



Both elevator_switch() and elevator_disable() are only called from the
two code paths, in which queue is guaranteed to be frozen.

So don't call freeze queue in the two functions, also add asserts for
queue freeze.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarNilay Shroff <nilay@linux.ibm.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250505141805.2751237-4-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 56dee46f

block/elevator.c

+2 −7
Original line number Diff line number Diff line
@@ -615,12 +615,11 @@ void elevator_init_mq(struct request_queue *q) 
 */

int elevator_switch(struct request_queue *q, struct elevator_type *new_e)

{

	unsigned int memflags;

	int ret;



	WARN_ON_ONCE(q->mq_freeze_depth == 0);

	lockdep_assert_held(&q->elevator_lock);



	memflags = blk_mq_freeze_queue(q);

	blk_mq_quiesce_queue(q);



	if (q->elevator) {
@@ -641,7 +640,6 @@ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) 


out_unfreeze:

	blk_mq_unquiesce_queue(q);

	blk_mq_unfreeze_queue(q, memflags);



	if (ret) {

		pr_warn("elv: switch to \"%s\" failed, falling back to \"none\"\n",
@@ -653,11 +651,9 @@ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) 


void elevator_disable(struct request_queue *q)

{

	unsigned int memflags;



	WARN_ON_ONCE(q->mq_freeze_depth == 0);

	lockdep_assert_held(&q->elevator_lock);



	memflags = blk_mq_freeze_queue(q);

	blk_mq_quiesce_queue(q);



	elv_unregister_queue(q);
@@ -668,7 +664,6 @@ void elevator_disable(struct request_queue *q) 
	blk_add_trace_msg(q, "elv switch: none");



	blk_mq_unquiesce_queue(q);

	blk_mq_unfreeze_queue(q, memflags);

}



/*