blkcg: implement per-queue policy activation

[linux-2.6-block.git] / block / blk-throttle.c

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 8c520fad6885411465ba0ce0e02389fef6ffed42..2fc964e06ea427c760d59bbd6a9aff8738411e25 100644 (file)
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -995,35 +995,31 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
        struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
        struct blkg_conf_ctx ctx;
        struct throtl_grp *tg;
+       struct throtl_data *td;
        int ret;
 
        ret = blkg_conf_prep(blkcg, &blkio_policy_throtl, buf, &ctx);
        if (ret)
                return ret;
 
-       ret = -EINVAL;
        tg = blkg_to_tg(ctx.blkg);
-       if (tg) {
-               struct throtl_data *td = ctx.blkg->q->td;
-
-               if (!ctx.v)
-                       ctx.v = -1;
+       td = ctx.blkg->q->td;
 
-               if (is_u64)
-                       *(u64 *)((void *)tg + cft->private) = ctx.v;
-               else
-                       *(unsigned int *)((void *)tg + cft->private) = ctx.v;
+       if (!ctx.v)
+               ctx.v = -1;
 
-               /* XXX: we don't need the following deferred processing */
-               xchg(&tg->limits_changed, true);
-               xchg(&td->limits_changed, true);
-               throtl_schedule_delayed_work(td, 0);
+       if (is_u64)
+               *(u64 *)((void *)tg + cft->private) = ctx.v;
+       else
+               *(unsigned int *)((void *)tg + cft->private) = ctx.v;
 
-               ret = 0;
-       }
+       /* XXX: we don't need the following deferred processing */
+       xchg(&tg->limits_changed, true);
+       xchg(&td->limits_changed, true);
+       throtl_schedule_delayed_work(td, 0);
 
        blkg_conf_finish(&ctx);
-       return ret;
+       return 0;
 }
 
 static int tg_set_conf_u64(struct cgroup *cgrp, struct cftype *cft,
@@ -1230,7 +1226,7 @@ void blk_throtl_drain(struct request_queue *q)
 int blk_throtl_init(struct request_queue *q)
 {
        struct throtl_data *td;
-       struct blkio_group *blkg;
+       int ret;
 
        td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node);
        if (!td)
@@ -1243,28 +1239,18 @@ int blk_throtl_init(struct request_queue *q)
        q->td = td;
        td->queue = q;
 
-       /* alloc and init root group. */
-       rcu_read_lock();
-       spin_lock_irq(q->queue_lock);
-
-       blkg = blkg_lookup_create(&blkio_root_cgroup, q, true);
-       if (!IS_ERR(blkg))
-               q->root_blkg = blkg;
-
-       spin_unlock_irq(q->queue_lock);
-       rcu_read_unlock();
-
-       if (!q->root_blkg) {
+       /* activate policy */
+       ret = blkcg_activate_policy(q, &blkio_policy_throtl);
+       if (ret)
                kfree(td);
-               return -ENOMEM;
-       }
-       return 0;
+       return ret;
 }
 
 void blk_throtl_exit(struct request_queue *q)
 {
        BUG_ON(!q->td);
        throtl_shutdown_wq(q);
+       blkcg_deactivate_policy(q, &blkio_policy_throtl);
        kfree(q->td);
 }