4 files changed, 69 insertions, 12 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4d4a277b2905..3ad497f4eed6 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 4f89b967467f..4d316df863b4 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 7f3f343b0c65..78f4829895bd 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 ef7b4798a349..000000000000
--- 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