Commit 84d7d462 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-cgroup: pin the gendisk in struct blkcg_gq 



Currently each blkcg_gq holds a request_queue reference, which is what
is used in the policies.  But a lot of these interfaces will move over to
use a gendisk, so store a disk in struct blkcg_gq and hold a reference to
it.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarAndreas Herrmann <aherrmann@suse.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-7-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 180b04d4

block/bfq-cgroup.c

+3 −3
Original line number Diff line number Diff line
@@ -405,7 +405,7 @@ static void bfqg_stats_xfer_dead(struct bfq_group *bfqg) 


	parent = bfqg_parent(bfqg);



	lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);

	lockdep_assert_held(&bfqg_to_blkg(bfqg)->disk->queue->queue_lock);



	if (unlikely(!parent))

		return;
@@ -536,7 +536,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd) 
{

	struct blkcg_gq *blkg = pd_to_blkg(pd);

	struct bfq_group *bfqg = blkg_to_bfqg(blkg);

	struct bfq_data *bfqd = blkg->q->elevator->elevator_data;

	struct bfq_data *bfqd = blkg->disk->queue->elevator->elevator_data;

	struct bfq_entity *entity = &bfqg->entity;

	struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
@@ -1201,7 +1201,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, 
	struct cgroup_subsys_state *pos_css;

	u64 sum = 0;



	lockdep_assert_held(&blkg->q->queue_lock);

	lockdep_assert_held(&blkg->disk->queue->queue_lock);



	rcu_read_lock();

	blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {

block/blk-cgroup-rwstat.c

+1 −1
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, 
	struct cgroup_subsys_state *pos_css;

	unsigned int i;



	lockdep_assert_held(&blkg->q->queue_lock);

	lockdep_assert_held(&blkg->disk->queue->queue_lock);



	memset(sum, 0, sizeof(*sum));

	rcu_read_lock();

block/blk-cgroup.c

+17 −18
Original line number Diff line number Diff line
@@ -116,7 +116,6 @@ static bool blkcg_policy_enabled(struct request_queue *q, 


static void blkg_free(struct blkcg_gq *blkg)

{

	struct request_queue *q = blkg->q;

	int i;



	/*
@@ -126,16 +125,16 @@ static void blkg_free(struct blkcg_gq *blkg) 
	 * blkcg_mutex is used to synchronize blkg_free_workfn() and

	 * blkcg_deactivate_policy().

	 */

	mutex_lock(&q->blkcg_mutex);

	mutex_lock(&blkg->disk->queue->blkcg_mutex);

	for (i = 0; i < BLKCG_MAX_POLS; i++)

		if (blkg->pd[i])

			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);

	if (blkg->parent)

		blkg_put(blkg->parent);

	list_del_init(&blkg->q_node);

	mutex_unlock(&q->blkcg_mutex);

	mutex_unlock(&blkg->disk->queue->blkcg_mutex);



	blk_put_queue(q);

	put_disk(blkg->disk);

	free_percpu(blkg->iostat_cpu);

	percpu_ref_exit(&blkg->refcnt);

	kfree(blkg);
@@ -251,10 +250,12 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk, 
	blkg->iostat_cpu = alloc_percpu_gfp(struct blkg_iostat_set, gfp_mask);

	if (!blkg->iostat_cpu)

		goto out_exit_refcnt;

	if (!blk_get_queue(disk->queue))



	if (test_bit(GD_DEAD, &disk->state))

		goto out_free_iostat;

	get_device(disk_to_dev(disk));

	blkg->disk = disk;



	blkg->q = disk->queue;

	INIT_LIST_HEAD(&blkg->q_node);

	spin_lock_init(&blkg->async_bio_lock);

	bio_list_init(&blkg->async_bios);
@@ -290,7 +291,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk, 
	while (--i >= 0)

		if (blkg->pd[i])

			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);

	blk_put_queue(disk->queue);

	put_disk(blkg->disk);

out_free_iostat:

	free_percpu(blkg->iostat_cpu);

out_exit_refcnt:
@@ -461,7 +462,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) 
	struct blkcg *blkcg = blkg->blkcg;

	int i;



	lockdep_assert_held(&blkg->q->queue_lock);

	lockdep_assert_held(&blkg->disk->queue->queue_lock);

	lockdep_assert_held(&blkcg->lock);



	/*
@@ -485,7 +486,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) 


	blkg->online = false;



	radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);

	radix_tree_delete(&blkcg->blkg_tree, blkg->disk->queue->id);

	hlist_del_init_rcu(&blkg->blkcg_node);



	/*
@@ -572,9 +573,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css, 


const char *blkg_dev_name(struct blkcg_gq *blkg)

{

	if (!blkg->q->disk)

		return NULL;

	return bdi_dev_name(blkg->q->disk->bdi);

	return bdi_dev_name(blkg->disk->bdi);

}



/**
@@ -606,10 +605,10 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, 


	rcu_read_lock();

	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {

		spin_lock_irq(&blkg->q->queue_lock);

		if (blkcg_policy_enabled(blkg->q, pol))

		spin_lock_irq(&blkg->disk->queue->queue_lock);

		if (blkcg_policy_enabled(blkg->disk->queue, pol))

			total += prfill(sf, blkg->pd[pol->plid], data);

		spin_unlock_irq(&blkg->q->queue_lock);

		spin_unlock_irq(&blkg->disk->queue->queue_lock);

	}

	rcu_read_unlock();
@@ -1033,9 +1032,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) 


	rcu_read_lock();

	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {

		spin_lock_irq(&blkg->q->queue_lock);

		spin_lock_irq(&blkg->disk->queue->queue_lock);

		blkcg_print_one_stat(blkg, sf);

		spin_unlock_irq(&blkg->q->queue_lock);

		spin_unlock_irq(&blkg->disk->queue->queue_lock);

	}

	rcu_read_unlock();

	return 0;
@@ -1105,7 +1104,7 @@ static void blkcg_destroy_blkgs(struct blkcg *blkcg) 
	while (!hlist_empty(&blkcg->blkg_list)) {

		struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first,

						struct blkcg_gq, blkcg_node);

		struct request_queue *q = blkg->q;

		struct request_queue *q = blkg->disk->queue;



		if (need_resched() || !spin_trylock(&q->queue_lock)) {

			/*

block/blk-cgroup.h

+5 −6
Original line number Diff line number Diff line
@@ -53,8 +53,7 @@ struct blkg_iostat_set { 


/* association between a blk cgroup and a request queue */

struct blkcg_gq {

	/* Pointer to the associated request_queue */

	struct request_queue		*q;

	struct gendisk			*disk;

	struct list_head		q_node;

	struct hlist_node		blkcg_node;

	struct blkcg			*blkcg;
@@ -255,11 +254,11 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, 
		return q->root_blkg;



	blkg = rcu_dereference(blkcg->blkg_hint);

	if (blkg && blkg->q == q)

	if (blkg && blkg->disk->queue == q)

		return blkg;



	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);

	if (blkg && blkg->q != q)

	if (blkg && blkg->disk->queue != q)

		blkg = NULL;

	return blkg;

}
@@ -359,7 +358,7 @@ static inline void blkg_put(struct blkcg_gq *blkg) 
#define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\

	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\

		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\

					    (p_blkg)->q)))

					    (p_blkg)->disk->queue)))



/**

 * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
@@ -374,7 +373,7 @@ static inline void blkg_put(struct blkcg_gq *blkg) 
#define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\

	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\

		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\

					    (p_blkg)->q)))

					    (p_blkg)->disk->queue)))



bool __blkcg_punt_bio_submit(struct bio *bio);

block/blk-iocost.c

+1 −1
Original line number Diff line number Diff line
@@ -2953,7 +2953,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) 
{

	struct ioc_gq *iocg = pd_to_iocg(pd);

	struct blkcg_gq *blkg = pd_to_blkg(&iocg->pd);

	struct ioc *ioc = q_to_ioc(blkg->q);

	struct ioc *ioc = q_to_ioc(blkg->disk->queue);

	struct ioc_now now;

	struct blkcg_gq *tblkg;

	unsigned long flags;