Commit 82b74cac authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe
Browse files

blk-ioprio: Convert from rqos policy to direct call 



Convert blk-ioprio handling from a rqos policy to a direct call from
blk_mq_submit_bio(). Firstly, blk-ioprio is not much of a rqos policy
anyway, it just needs a hook in bio submission path to set the bio's IO
priority. Secondly, the rqos .track hook gets actually called too late
for blk-ioprio purposes and introducing a special rqos hook just for
blk-ioprio looks even weirder.

Reviewed-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220623074840.5960-7-jack@suse.cz


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f2586544

block/blk-cgroup.c

+1 −0
Original line number Diff line number Diff line
@@ -1299,6 +1299,7 @@ int blkcg_init_queue(struct request_queue *q) 
	ret = blk_iolatency_init(q);

	if (ret) {

		blk_throtl_exit(q);

		blk_ioprio_exit(q);

		goto err_destroy_all;

	}

block/blk-ioprio.c

+5 −45
Original line number Diff line number Diff line
@@ -181,17 +181,12 @@ static struct blkcg_policy ioprio_policy = { 
	.pd_free_fn	= ioprio_free_pd,

};



struct blk_ioprio {

	struct rq_qos rqos;

};



static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq,

			       struct bio *bio)

void blkcg_set_ioprio(struct bio *bio)

{

	struct ioprio_blkcg *blkcg = ioprio_blkcg_from_bio(bio);

	u16 prio;



	if (blkcg->prio_policy == POLICY_NO_CHANGE)

	if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)

		return;



	/*
@@ -207,49 +202,14 @@ static void blkcg_ioprio_track(struct rq_qos *rqos, struct request *rq, 
		bio->bi_ioprio = prio;

}



static void blkcg_ioprio_exit(struct rq_qos *rqos)

void blk_ioprio_exit(struct request_queue *q)

{

	struct blk_ioprio *blkioprio_blkg =

		container_of(rqos, typeof(*blkioprio_blkg), rqos);



	blkcg_deactivate_policy(rqos->q, &ioprio_policy);

	kfree(blkioprio_blkg);

	blkcg_deactivate_policy(q, &ioprio_policy);

}



static struct rq_qos_ops blkcg_ioprio_ops = {

	.track	= blkcg_ioprio_track,

	.exit	= blkcg_ioprio_exit,

};



int blk_ioprio_init(struct request_queue *q)

{

	struct blk_ioprio *blkioprio_blkg;

	struct rq_qos *rqos;

	int ret;



	blkioprio_blkg = kzalloc(sizeof(*blkioprio_blkg), GFP_KERNEL);

	if (!blkioprio_blkg)

		return -ENOMEM;



	ret = blkcg_activate_policy(q, &ioprio_policy);

	if (ret) {

		kfree(blkioprio_blkg);

		return ret;

	}



	rqos = &blkioprio_blkg->rqos;

	rqos->id = RQ_QOS_IOPRIO;

	rqos->ops = &blkcg_ioprio_ops;

	rqos->q = q;



	/*

	 * Registering the rq-qos policy after activating the blk-cgroup

	 * policy guarantees that ioprio_blkcg_from_bio(bio) != NULL in the

	 * rq-qos callbacks.

	 */

	rq_qos_add(q, rqos);



	return 0;

	return blkcg_activate_policy(q, &ioprio_policy);

}



static int __init ioprio_init(void)

block/blk-ioprio.h

+9 −0
Original line number Diff line number Diff line
@@ -6,14 +6,23 @@ 
#include <linux/kconfig.h>



struct request_queue;

struct bio;



#ifdef CONFIG_BLK_CGROUP_IOPRIO

int blk_ioprio_init(struct request_queue *q);

void blk_ioprio_exit(struct request_queue *q);

void blkcg_set_ioprio(struct bio *bio);

#else

static inline int blk_ioprio_init(struct request_queue *q)

{

	return 0;

}

static inline void blk_ioprio_exit(struct request_queue *q)

{

}

static inline void blkcg_set_ioprio(struct bio *bio)

{

}

#endif



#endif /* _BLK_IOPRIO_H_ */

block/blk-mq.c

+8 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include "blk-stat.h"

#include "blk-mq-sched.h"

#include "blk-rq-qos.h"

#include "blk-ioprio.h"



static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
@@ -2779,6 +2780,11 @@ static inline struct request *blk_mq_get_cached_request(struct request_queue *q, 
	return rq;

}



static void bio_set_ioprio(struct bio *bio)

{

	blkcg_set_ioprio(bio);

}



/**

 * blk_mq_submit_bio - Create and send a request to block device.

 * @bio: Bio pointer.
@@ -2819,6 +2825,8 @@ void blk_mq_submit_bio(struct bio *bio) 


	trace_block_getrq(bio);



	bio_set_ioprio(bio);



	rq_qos_track(q, rq, bio);



	blk_mq_bio_to_request(rq, bio, nr_segs);