@@ -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);
@@ -17,10 +17,38 @@
#include <linux/blk-cgroup.h>
#include <linux/blk-mq.h>
+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
@@ -17,8 +17,6 @@
#include <linux/backing-dev-defs.h>
#include <linux/slab.h>
-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)
{
}
@@ -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 {
};
@@ -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);
}
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 <hch@lst.de> --- 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(-)