From dec223c92a4688f6c9642d640cfe15a99d289dd4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Apr 2022 06:27:15 +0200 Subject: [PATCH] blk-cgroup: move struct blkcg to block/blk-cgroup.h There is no real need to expose the blkcg structure to the whole kernel. Move it to the private header an expose a helper to let the writeback code access the cgwb_list member. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220420042723.1010598-8-hch@lst.de Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 9 ++++++++- block/blk-cgroup.h | 28 ++++++++++++++++++++++++++++ include/linux/backing-dev.h | 6 ++---- include/linux/blk-cgroup.h | 32 +------------------------------- mm/backing-dev.c | 13 ++++++------- 5 files changed, 45 insertions(+), 43 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 3af0d4a..bb52797 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1005,6 +1005,13 @@ static struct cftype blkcg_legacy_files[] = { { } /* terminate */ }; +#ifdef CONFIG_CGROUP_WRITEBACK +struct list_head *blkcg_get_cgwb_list(struct cgroup_subsys_state *css) +{ + return &css_to_blkcg(css)->cgwb_list; +} +#endif + /* * blkcg destruction is a three-stage process. * @@ -1112,7 +1119,7 @@ void blkcg_unpin_online(struct cgroup_subsys_state *blkcg_css) static void blkcg_css_offline(struct cgroup_subsys_state *css) { /* this prevents anyone from attaching or migrating to this blkcg */ - wb_blkcg_offline(css_to_blkcg(css)); + wb_blkcg_offline(css); /* put the base online pin allowing step 2 to be triggered */ blkcg_unpin_online(css); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 49e88fc..b00fb11 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -17,10 +17,38 @@ #include #include +struct blkcg_gq; +struct blkg_policy_data; + + /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) #ifdef CONFIG_BLK_CGROUP +struct blkcg { + struct cgroup_subsys_state css; + spinlock_t lock; + refcount_t online_pin; + + struct radix_tree_root blkg_tree; + struct blkcg_gq __rcu *blkg_hint; + struct hlist_head blkg_list; + + struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; + + struct list_head all_blkcgs_node; +#ifdef CONFIG_BLK_CGROUP_FC_APPID + char fc_app_id[FC_APPID_LEN]; +#endif +#ifdef CONFIG_CGROUP_WRITEBACK + struct list_head cgwb_list; +#endif +}; + +static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) +{ + return css ? container_of(css, struct blkcg, css) : NULL; +} /* * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 87ce24d..2bd073f 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -17,8 +17,6 @@ #include #include -struct blkcg; - static inline struct backing_dev_info *bdi_get(struct backing_dev_info *bdi) { kref_get(&bdi->refcnt); @@ -154,7 +152,7 @@ struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, struct cgroup_subsys_state *memcg_css, gfp_t gfp); void wb_memcg_offline(struct mem_cgroup *memcg); -void wb_blkcg_offline(struct blkcg *blkcg); +void wb_blkcg_offline(struct cgroup_subsys_state *css); /** * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode @@ -378,7 +376,7 @@ static inline void wb_memcg_offline(struct mem_cgroup *memcg) { } -static inline void wb_blkcg_offline(struct blkcg *blkcg) +static inline void wb_blkcg_offline(struct cgroup_subsys_state *css) { } diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 0fb7459..d7b1880 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -37,29 +37,6 @@ enum blkg_iostat_type { BLKG_IOSTAT_NR, }; -struct blkcg_gq; -struct blkg_policy_data; - -struct blkcg { - struct cgroup_subsys_state css; - spinlock_t lock; - refcount_t online_pin; - - struct radix_tree_root blkg_tree; - struct blkcg_gq __rcu *blkg_hint; - struct hlist_head blkg_list; - - struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; - - struct list_head all_blkcgs_node; -#ifdef CONFIG_BLK_CGROUP_FC_APPID - char fc_app_id[FC_APPID_LEN]; -#endif -#ifdef CONFIG_CGROUP_WRITEBACK - struct list_head cgwb_list; -#endif -}; - struct blkg_iostat { u64 bytes[BLKG_IOSTAT_NR]; u64 ios[BLKG_IOSTAT_NR]; @@ -114,11 +91,6 @@ 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); -static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) -{ - return css ? container_of(css, struct blkcg, css) : NULL; -} - /** * bio_blkcg - grab the blkcg associated with a bio * @bio: target bio @@ -137,12 +109,10 @@ static inline struct blkcg *bio_blkcg(struct bio *bio) 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); #else /* CONFIG_BLK_CGROUP */ -struct blkcg { -}; - struct blkcg_gq { }; diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 93cddbc..98f8f62 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -445,7 +445,6 @@ static int cgwb_create(struct backing_dev_info *bdi, { struct mem_cgroup *memcg; struct cgroup_subsys_state *blkcg_css; - struct blkcg *blkcg; struct list_head *memcg_cgwb_list, *blkcg_cgwb_list; struct bdi_writeback *wb; unsigned long flags; @@ -453,9 +452,8 @@ static int cgwb_create(struct backing_dev_info *bdi, memcg = mem_cgroup_from_css(memcg_css); blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys); - blkcg = css_to_blkcg(blkcg_css); memcg_cgwb_list = &memcg->cgwb_list; - blkcg_cgwb_list = &blkcg->cgwb_list; + blkcg_cgwb_list = blkcg_get_cgwb_list(blkcg_css); /* look up again under lock and discard on blkcg mismatch */ spin_lock_irqsave(&cgwb_lock, flags); @@ -723,18 +721,19 @@ void wb_memcg_offline(struct mem_cgroup *memcg) /** * wb_blkcg_offline - kill all wb's associated with a blkcg being offlined - * @blkcg: blkcg being offlined + * @css: blkcg being offlined * * Also prevents creation of any new wb's associated with @blkcg. */ -void wb_blkcg_offline(struct blkcg *blkcg) +void wb_blkcg_offline(struct cgroup_subsys_state *css) { struct bdi_writeback *wb, *next; + struct list_head *list = blkcg_get_cgwb_list(css); spin_lock_irq(&cgwb_lock); - list_for_each_entry_safe(wb, next, &blkcg->cgwb_list, blkcg_node) + list_for_each_entry_safe(wb, next, list, blkcg_node) cgwb_kill(wb); - blkcg->cgwb_list.next = NULL; /* prevent new wb's */ + list->next = NULL; /* prevent new wb's */ spin_unlock_irq(&cgwb_lock); } -- 2.7.4