From bbb1ebe7a909db4de49777fb7676d5bf293f34c9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Apr 2022 06:27:17 +0200 Subject: blk-cgroup: replace bio_blkcg with bio_blkcg_css All callers of bio_blkcg actually want the CSS, so replace it with an interface that does return the CSS. This now allows to move struct blkcg_gq to block/blk-cgroup.h instead of exposing it in a public header. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220420042723.1010598-10-hch@lst.de Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 18 +++++++++- block/blk-cgroup.h | 67 +++++++++++++++++++++++++++++++++++-- drivers/block/loop.c | 12 ++++--- include/linux/blk-cgroup.h | 83 +++------------------------------------------- kernel/trace/blktrace.c | 6 ++-- 5 files changed, 97 insertions(+), 89 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index bb52797c02bd..8e32cc494808 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -155,6 +155,22 @@ static void blkg_async_bio_workfn(struct work_struct *work) blk_finish_plug(&plug); } +/** + * bio_blkcg_css - return the blkcg CSS associated with a bio + * @bio: target bio + * + * This returns the CSS for the blkcg associated with a bio, or %NULL if not + * associated. Callers are expected to either handle %NULL or know association + * has been done prior to calling this. + */ +struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio) +{ + if (!bio || !bio->bi_blkg) + return NULL; + return &bio->bi_blkg->blkcg->css; +} +EXPORT_SYMBOL_GPL(bio_blkcg_css); + /** * blkcg_parent - get the parent of a blkcg * @blkcg: blkcg of interest @@ -1938,7 +1954,7 @@ void bio_associate_blkg(struct bio *bio) rcu_read_lock(); if (bio->bi_blkg) - css = &bio_blkcg(bio)->css; + css = bio_blkcg_css(bio); else css = blkcg_css(); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index b00fb1169e7c..03405ddf2a7b 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -25,6 +25,64 @@ struct blkg_policy_data; #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) #ifdef CONFIG_BLK_CGROUP + +enum blkg_iostat_type { + BLKG_IOSTAT_READ, + BLKG_IOSTAT_WRITE, + BLKG_IOSTAT_DISCARD, + + BLKG_IOSTAT_NR, +}; + +struct blkg_iostat { + u64 bytes[BLKG_IOSTAT_NR]; + u64 ios[BLKG_IOSTAT_NR]; +}; + +struct blkg_iostat_set { + struct u64_stats_sync sync; + struct blkg_iostat cur; + struct blkg_iostat last; +}; + +/* association between a blk cgroup and a request queue */ +struct blkcg_gq { + /* Pointer to the associated request_queue */ + struct request_queue *q; + struct list_head q_node; + struct hlist_node blkcg_node; + struct blkcg *blkcg; + + /* all non-root blkcg_gq's are guaranteed to have access to parent */ + struct blkcg_gq *parent; + + /* reference count */ + struct percpu_ref refcnt; + + /* is this blkg online? protected by both blkcg and q locks */ + bool online; + + struct blkg_iostat_set __percpu *iostat_cpu; + struct blkg_iostat_set iostat; + + struct blkg_policy_data *pd[BLKCG_MAX_POLS]; + + spinlock_t async_bio_lock; + struct bio_list async_bios; + union { + struct work_struct async_bio_work; + struct work_struct free_work; + }; + + atomic_t use_delay; + atomic64_t delay_nsec; + atomic64_t delay_start; + u64 last_delay; + int last_use; + + struct rcu_head rcu_head; +}; + struct blkcg { struct cgroup_subsys_state css; spinlock_t lock; @@ -173,9 +231,9 @@ static inline struct cgroup_subsys_state *blkcg_css(void) * * In order to avoid priority inversions we sometimes need to issue a bio as if * it were attached to the root blkg, and then backcharge to the actual owning - * blkg. The idea is we do bio_blkcg() to look up the actual context for the - * bio and attach the appropriate blkg to the bio. Then we call this helper and - * if it is true run with the root blkg for that queue and then do any + * blkg. The idea is we do bio_blkcg_css() to look up the actual context for + * the bio and attach the appropriate blkg to the bio. Then we call this helper + * and if it is true run with the root blkg for that queue and then do any * backcharging to the originating cgroup once the io is complete. */ static inline bool bio_issue_as_root_blkg(struct bio *bio) @@ -464,6 +522,9 @@ struct blkcg_policy_data { struct blkcg_policy { }; +struct blkcg { +}; + #ifdef CONFIG_BLOCK static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 976cf987b392..fabcf647306a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1829,12 +1829,14 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, cmd->blkcg_css = NULL; cmd->memcg_css = NULL; #ifdef CONFIG_BLK_CGROUP - if (rq->bio && rq->bio->bi_blkg) { - cmd->blkcg_css = &bio_blkcg(rq->bio)->css; + if (rq->bio) { + cmd->blkcg_css = bio_blkcg_css(rq->bio); #ifdef CONFIG_MEMCG - cmd->memcg_css = - cgroup_get_e_css(cmd->blkcg_css->cgroup, - &memory_cgrp_subsys); + if (cmd->blkcg_css) { + cmd->memcg_css = + cgroup_get_e_css(cmd->blkcg_css->cgroup, + &memory_cgrp_subsys); + } #endif } #endif diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index d7b188095040..97c7968e3204 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -28,94 +28,18 @@ #define FC_APPID_LEN 129 #ifdef CONFIG_BLK_CGROUP - -enum blkg_iostat_type { - BLKG_IOSTAT_READ, - BLKG_IOSTAT_WRITE, - BLKG_IOSTAT_DISCARD, - - BLKG_IOSTAT_NR, -}; - -struct blkg_iostat { - u64 bytes[BLKG_IOSTAT_NR]; - u64 ios[BLKG_IOSTAT_NR]; -}; - -struct blkg_iostat_set { - struct u64_stats_sync sync; - struct blkg_iostat cur; - struct blkg_iostat last; -}; - -/* association between a blk cgroup and a request queue */ -struct blkcg_gq { - /* Pointer to the associated request_queue */ - struct request_queue *q; - struct list_head q_node; - struct hlist_node blkcg_node; - struct blkcg *blkcg; - - /* all non-root blkcg_gq's are guaranteed to have access to parent */ - struct blkcg_gq *parent; - - /* reference count */ - struct percpu_ref refcnt; - - /* is this blkg online? protected by both blkcg and q locks */ - bool online; - - struct blkg_iostat_set __percpu *iostat_cpu; - struct blkg_iostat_set iostat; - - struct blkg_policy_data *pd[BLKCG_MAX_POLS]; - - spinlock_t async_bio_lock; - struct bio_list async_bios; - union { - struct work_struct async_bio_work; - struct work_struct free_work; - }; - - atomic_t use_delay; - atomic64_t delay_nsec; - atomic64_t delay_start; - u64 last_delay; - int last_use; - - struct rcu_head rcu_head; -}; - extern struct cgroup_subsys_state * const blkcg_root_css; void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay); void blkcg_maybe_throttle_current(void); - -/** - * bio_blkcg - grab the blkcg associated with a bio - * @bio: target bio - * - * This returns the blkcg associated with a bio, %NULL if not associated. - * Callers are expected to either handle %NULL or know association has been - * done prior to calling this. - */ -static inline struct blkcg *bio_blkcg(struct bio *bio) -{ - if (bio && bio->bi_blkg) - return bio->bi_blkg->blkcg; - return NULL; -} - bool blk_cgroup_congested(void); void blkcg_pin_online(struct cgroup_subsys_state *blkcg_css); void blkcg_unpin_online(struct cgroup_subsys_state *blkcg_css); struct list_head *blkcg_get_cgwb_list(struct cgroup_subsys_state *css); +struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio); #else /* CONFIG_BLK_CGROUP */ -struct blkcg_gq { -}; - #define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL)) static inline void blkcg_maybe_throttle_current(void) { } @@ -123,7 +47,10 @@ static inline bool blk_cgroup_congested(void) { return false; } #ifdef CONFIG_BLOCK static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { } -static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } +static inline struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio) +{ + return NULL; +} #endif /* CONFIG_BLOCK */ #endif /* CONFIG_BLK_CGROUP */ diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 9ef349ac49c0..10a32b0f2deb 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -783,6 +783,7 @@ void blk_trace_shutdown(struct request_queue *q) #ifdef CONFIG_BLK_CGROUP static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) { + struct cgroup_subsys_state *blkcg_css; struct blk_trace *bt; /* We don't use the 'bt' value here except as an optimization... */ @@ -790,9 +791,10 @@ static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) if (!bt || !(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP)) return 0; - if (!bio->bi_blkg) + blkcg_css = bio_blkcg_css(bio); + if (!blkcg_css) return 0; - return cgroup_id(bio_blkcg(bio)->css.cgroup); + return cgroup_id(blkcg_css->cgroup); } #else static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio) -- cgit v1.2.3-59-g8ed1b