X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=block%2Fblk-cgroup.c;h=2cc682b860ead9d15350620c595bfbb30f4a533d;hb=8213466596bf10b75887754773ee13c10cf86f5c;hp=4d4a277b2905de7bef24e8eb126f08df63284702;hpb=9d6a986c0b276085f7944cd8ad65f4f82aff7536;p=safe%2Fjmp%2Flinux-2.6

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4d4a277..2cc682b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -14,25 +14,40 @@
 #include <linux/seq_file.h>
 #include <linux/kdev_t.h>
 #include <linux/module.h>
+#include <linux/err.h>
+#include <linux/slab.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);
 
-bool blkiocg_css_tryget(struct blkio_cgroup *blkcg)
-{
-	if (!css_tryget(&blkcg->css))
-		return false;
-	return true;
-}
-EXPORT_SYMBOL_GPL(blkiocg_css_tryget);
+static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
+						  struct cgroup *);
+static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
+			      struct task_struct *, bool);
+static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
+			   struct cgroup *, struct task_struct *, bool);
+static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
+static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
 
-void blkiocg_css_put(struct blkio_cgroup *blkcg)
-{
-	css_put(&blkcg->css);
-}
-EXPORT_SYMBOL_GPL(blkiocg_css_put);
+struct cgroup_subsys blkio_subsys = {
+	.name = "blkio",
+	.create = blkiocg_create,
+	.can_attach = blkiocg_can_attach,
+	.attach = blkiocg_attach,
+	.destroy = blkiocg_destroy,
+	.populate = blkiocg_populate,
+#ifdef CONFIG_BLK_CGROUP
+	/* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */
+	.subsys_id = blkio_subsys_id,
+#endif
+	.use_id = 1,
+	.module = THIS_MODULE,
+};
+EXPORT_SYMBOL_GPL(blkio_subsys);
 
 struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
 {
@@ -138,16 +153,22 @@ 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;
 
 	blkcg = cgroup_to_blkio_cgroup(cgroup);
+	spin_lock(&blkio_list_lock);
 	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) {
+		list_for_each_entry(blkiop, &blkio_list, list)
+			blkiop->ops.blkio_update_group_weight_fn(blkg,
+					blkcg->weight);
+	}
 	spin_unlock_irq(&blkcg->lock);
+	spin_unlock(&blkio_list_lock);
 	return 0;
 }
 
@@ -224,6 +245,7 @@ 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:
@@ -249,27 +271,31 @@ 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);
 	rcu_read_unlock();
-	kfree(blkcg);
+	if (blkcg != &blkio_root_cgroup)
+		kfree(blkcg);
 }
 
 static struct cgroup_subsys_state *
 blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)
 {
-	struct blkio_cgroup *blkcg, *parent_blkcg;
+	struct blkio_cgroup *blkcg;
+	struct cgroup *parent = cgroup->parent;
 
-	if (!cgroup->parent) {
+	if (!parent) {
 		blkcg = &blkio_root_cgroup;
 		goto done;
 	}
 
 	/* Currently we do not support hierarchy deeper than two level (0,1) */
-	parent_blkcg = cgroup_to_blkio_cgroup(cgroup->parent);
-	if (css_depth(&parent_blkcg->css) > 0)
+	if (parent != cgroup->top_cgroup)
 		return ERR_PTR(-EINVAL);
 
 	blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
@@ -320,13 +346,32 @@ static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup,
 	task_unlock(tsk);
 }
 
-struct cgroup_subsys blkio_subsys = {
-	.name = "blkio",
-	.create = blkiocg_create,
-	.can_attach = blkiocg_can_attach,
-	.attach = blkiocg_attach,
-	.destroy = blkiocg_destroy,
-	.populate = blkiocg_populate,
-	.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);
+
+static int __init init_cgroup_blkio(void)
+{
+	return cgroup_load_subsys(&blkio_subsys);
+}
+
+static void __exit exit_cgroup_blkio(void)
+{
+	cgroup_unload_subsys(&blkio_subsys);
+}
+
+module_init(init_cgroup_blkio);
+module_exit(exit_cgroup_blkio);
+MODULE_LICENSE("GPL");