1 files changed, 16 insertions, 242 deletions

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 652cd05b0924..9f40dbc65f82 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -14,265 +14,39 @@
  * 	              Nauman Rafique <nauman@google.com>
  */
 
-#include <linux/cgroup.h>
-#include <linux/percpu.h>
-#include <linux/percpu_counter.h>
-#include <linux/u64_stats_sync.h>
-#include <linux/seq_file.h>
-#include <linux/radix-tree.h>
-#include <linux/blkdev.h>
-#include <linux/atomic.h>
-#include <linux/kthread.h>
-#include <linux/fs.h>
+#include <linux/types.h>
+
+struct bio;
+struct cgroup_subsys_state;
+struct request_queue;
 
 #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 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];
-};
-
-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_destroy_blkgs(struct blkcg *blkcg);
 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
- *
- * 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;
-}
-
-static inline bool blk_cgroup_congested(void)
-{
-	struct cgroup_subsys_state *css;
-	bool ret = false;
-
-	rcu_read_lock();
-	css = kthread_blkcg();
-	if (!css)
-		css = task_css(current, io_cgrp_id);
-	while (css) {
-		if (atomic_read(&css->cgroup->congestion_count)) {
-			ret = true;
-			break;
-		}
-		css = css->parent;
-	}
-	rcu_read_unlock();
-	return ret;
-}
-
-/**
- * blkcg_parent - get the parent of a blkcg
- * @blkcg: blkcg of interest
- *
- * Return the parent blkcg of @blkcg.  Can be called anytime.
- */
-static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
-{
-	return css_to_blkcg(blkcg->css.parent);
-}
-
-/**
- * blkcg_pin_online - pin online state
- * @blkcg: blkcg of interest
- *
- * While pinned, a blkcg is kept online.  This is primarily used to
- * impedance-match blkg and cgwb lifetimes so that blkg doesn't go offline
- * while an associated cgwb is still active.
- */
-static inline void blkcg_pin_online(struct blkcg *blkcg)
-{
-	refcount_inc(&blkcg->online_pin);
-}
-
-/**
- * blkcg_unpin_online - unpin online state
- * @blkcg: blkcg of interest
- *
- * This is primarily used to impedance-match blkg and cgwb lifetimes so
- * that blkg doesn't go offline while an associated cgwb is still active.
- * When this count goes to zero, all active cgwbs have finished so the
- * blkcg can continue destruction by calling blkcg_destroy_blkgs().
- */
-static inline void blkcg_unpin_online(struct blkcg *blkcg)
-{
-	do {
-		if (!refcount_dec_and_test(&blkcg->online_pin))
-			break;
-		blkcg_destroy_blkgs(blkcg);
-		blkcg = blkcg_parent(blkcg);
-	} while (blkcg);
-}
+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 {
-};
-
-struct blkcg_gq {
-};
-
 #define blkcg_root_css	((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
 
 static inline void blkcg_maybe_throttle_current(void) { }
 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; }
-#endif /* CONFIG_BLOCK */
-
-#endif	/* CONFIG_BLK_CGROUP */
-
-#ifdef CONFIG_BLK_CGROUP_FC_APPID
-/*
- * Sets the fc_app_id field associted to blkcg
- * @app_id: application identifier
- * @cgrp_id: cgroup id
- * @app_id_len: size of application identifier
- */
-static inline int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len)
-{
-	struct cgroup *cgrp;
-	struct cgroup_subsys_state *css;
-	struct blkcg *blkcg;
-	int ret  = 0;
-
-	if (app_id_len > FC_APPID_LEN)
-		return -EINVAL;
-
-	cgrp = cgroup_get_from_id(cgrp_id);
-	if (!cgrp)
-		return -ENOENT;
-	css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
-	if (!css) {
-		ret = -ENOENT;
-		goto out_cgrp_put;
-	}
-	blkcg = css_to_blkcg(css);
-	/*
-	 * There is a slight race condition on setting the appid.
-	 * Worst case an I/O may not find the right id.
-	 * This is no different from the I/O we let pass while obtaining
-	 * the vmid from the fabric.
-	 * Adding the overhead of a lock is not necessary.
-	 */
-	strlcpy(blkcg->fc_app_id, app_id, app_id_len);
-	css_put(css);
-out_cgrp_put:
-	cgroup_put(cgrp);
-	return ret;
-}
-
-/**
- * blkcg_get_fc_appid - get the fc app identifier associated with a bio
- * @bio: target bio
- *
- * On success return the fc_app_id, on failure return NULL
- */
-static inline char *blkcg_get_fc_appid(struct bio *bio)
+static inline struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio)
 {
-	if (bio && bio->bi_blkg &&
-		(bio->bi_blkg->blkcg->fc_app_id[0] != '\0'))
-		return bio->bi_blkg->blkcg->fc_app_id;
 	return NULL;
 }
-#else
-static inline int blkcg_set_fc_appid(char *buf, u64 id, size_t len) { return -EINVAL; }
-static inline char *blkcg_get_fc_appid(struct bio *bio) { return NULL; }
-#endif /*CONFIG_BLK_CGROUP_FC_APPID*/
+#endif	/* CONFIG_BLK_CGROUP */
+
+int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len);
+char *blkcg_get_fc_appid(struct bio *bio);
+
 #endif	/* _BLK_CGROUP_H */