4 files changed, 69 insertions, 12 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4d4a277b290..3ad497f4eed 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -15,7 +15,9 @@
 #include <linux/kdev_t.h>
 #include <linux/module.h>
 #include "blk-cgroup.h"
-#include "cfq-iosched.h"
+
+static DEFINE_SPINLOCK(blkio_list_lock);
+static LIST_HEAD(blkio_list);
 
 struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
 EXPORT_SYMBOL_GPL(blkio_root_cgroup);
@@ -138,6 +140,7 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 	struct blkio_cgroup *blkcg;
 	struct blkio_group *blkg;
 	struct hlist_node *n;
+	struct blkio_policy_type *blkiop;
 
 	if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
 		return -EINVAL;
@@ -145,8 +148,13 @@ blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 	blkcg = cgroup_to_blkio_cgroup(cgroup);
 	spin_lock_irq(&blkcg->lock);
 	blkcg->weight = (unsigned int)val;
-	hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node)
-		cfq_update_blkio_group_weight(blkg, blkcg->weight);
+	hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+		spin_lock(&blkio_list_lock);
+		list_for_each_entry(blkiop, &blkio_list, list)
+			blkiop->ops.blkio_update_group_weight_fn(blkg,
+					blkcg->weight);
+		spin_unlock(&blkio_list_lock);
+	}
 	spin_unlock_irq(&blkcg->lock);
 	return 0;
 }
@@ -224,6 +232,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
 	unsigned long flags;
 	struct blkio_group *blkg;
 	void *key;
+	struct blkio_policy_type *blkiop;
 
 	rcu_read_lock();
 remove_entry:
@@ -249,7 +258,10 @@ remove_entry:
 	 * we have more policies in place, we need some dynamic registration
 	 * of callback function.
 	 */
-	cfq_unlink_blkio_group(key, blkg);
+	spin_lock(&blkio_list_lock);
+	list_for_each_entry(blkiop, &blkio_list, list)
+		blkiop->ops.blkio_unlink_group_fn(key, blkg);
+	spin_unlock(&blkio_list_lock);
 	goto remove_entry;
 done:
 	free_css_id(&blkio_subsys, &blkcg->css);
@@ -330,3 +342,19 @@ struct cgroup_subsys blkio_subsys = {
 	.subsys_id = blkio_subsys_id,
 	.use_id = 1,
 };
+
+void blkio_policy_register(struct blkio_policy_type *blkiop)
+{
+	spin_lock(&blkio_list_lock);
+	list_add_tail(&blkiop->list, &blkio_list);
+	spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_register);
+
+void blkio_policy_unregister(struct blkio_policy_type *blkiop)
+{
+	spin_lock(&blkio_list_lock);
+	list_del_init(&blkiop->list);
+	spin_unlock(&blkio_list_lock);
+}
+EXPORT_SYMBOL_GPL(blkio_policy_unregister);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 4f89b967467..4d316df863b 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -46,11 +46,35 @@ struct blkio_group {
 extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
 extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
 
+typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
+typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
+						unsigned int weight);
+
+struct blkio_policy_ops {
+	blkio_unlink_group_fn *blkio_unlink_group_fn;
+	blkio_update_group_weight_fn *blkio_update_group_weight_fn;
+};
+
+struct blkio_policy_type {
+	struct list_head list;
+	struct blkio_policy_ops ops;
+};
+
+/* Blkio controller policy registration */
+extern void blkio_policy_register(struct blkio_policy_type *);
+extern void blkio_policy_unregister(struct blkio_policy_type *);
+
 #else
 
 struct blkio_group {
 };
 
+struct blkio_policy_type {
+};
+
+static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
+static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
+
 #endif
 
 #define BLKIO_WEIGHT_MIN	100
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 7f3f343b0c6..78f4829895b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -14,7 +14,6 @@
 #include <linux/ioprio.h>
 #include <linux/blktrace_api.h>
 #include "blk-cgroup.h"
-#include "cfq-iosched.h"
 
 /*
  * tunables
@@ -3855,6 +3854,17 @@ static struct elevator_type iosched_cfq = {
 	.elevator_owner =	THIS_MODULE,
 };
 
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+static struct blkio_policy_type blkio_policy_cfq = {
+	.ops = {
+		.blkio_unlink_group_fn =	cfq_unlink_blkio_group,
+		.blkio_update_group_weight_fn =	cfq_update_blkio_group_weight,
+	},
+};
+#else
+static struct blkio_policy_type blkio_policy_cfq;
+#endif
+
 static int __init cfq_init(void)
 {
 	/*
@@ -3869,6 +3879,7 @@ static int __init cfq_init(void)
 		return -ENOMEM;
 
 	elv_register(&iosched_cfq);
+	blkio_policy_register(&blkio_policy_cfq);
 
 	return 0;
 }
@@ -3876,6 +3887,7 @@ static int __init cfq_init(void)
 static void __exit cfq_exit(void)
 {
 	DECLARE_COMPLETION_ONSTACK(all_gone);
+	blkio_policy_unregister(&blkio_policy_cfq);
 	elv_unregister(&iosched_cfq);
 	ioc_gone = &all_gone;
 	/* ioc_gone's update must be visible before reading ioc_count */
diff --git a/block/cfq-iosched.h b/block/cfq-iosched.h
deleted file mode 100644
index ef7b4798a34..00000000000
--- a/block/cfq-iosched.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#ifndef CFQ_IOSCHED_H
-#define CFQ_IOSCHED_H
-
-void cfq_unlink_blkio_group(void *, struct blkio_group *);
-void cfq_update_blkio_group_weight(struct blkio_group *, unsigned int);
-
-#endif