X-Git-Url: http://git.agner.ch/gitweb/?a=blobdiff_plain;f=block%2Fblk-cgroup.c;h=4e491d9b529255476939b8608d91718c40140059;hb=c2ac2ae44d4c32382d001672021116e771bef4c9;hp=e90c7c164c83b8dc58f36393bb5748c0110e6184;hpb=e125096e733e966e055ee6033169f68233f9bf9c;p=linux-drm-fsl-dcu.git

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e90c7c164c83..4e491d9b5292 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -235,8 +235,13 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
 	blkg->online = true;
 	spin_unlock(&blkcg->lock);
 
-	if (!ret)
+	if (!ret) {
+		if (blkcg == &blkcg_root) {
+			q->root_blkg = blkg;
+			q->root_rl.blkg = blkg;
+		}
 		return blkg;
+	}
 
 	/* @blkg failed fully initialized, use the usual release path */
 	blkg_put(blkg);
@@ -334,6 +339,15 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 	if (rcu_dereference_raw(blkcg->blkg_hint) == blkg)
 		rcu_assign_pointer(blkcg->blkg_hint, NULL);
 
+	/*
+	 * If root blkg is destroyed.  Just clear the pointer since root_rl
+	 * does not take reference on root blkg.
+	 */
+	if (blkcg == &blkcg_root) {
+		blkg->q->root_blkg = NULL;
+		blkg->q->root_rl.blkg = NULL;
+	}
+
 	/*
 	 * Put the reference taken at the time of creation so that when all
 	 * queues are gone, group can be destroyed.
@@ -360,13 +374,6 @@ static void blkg_destroy_all(struct request_queue *q)
 		blkg_destroy(blkg);
 		spin_unlock(&blkcg->lock);
 	}
-
-	/*
-	 * root blkg is destroyed.  Just clear the pointer since
-	 * root_rl does not take reference on root blkg.
-	 */
-	q->root_blkg = NULL;
-	q->root_rl.blkg = NULL;
 }
 
 /*
@@ -970,8 +977,6 @@ int blkcg_activate_policy(struct request_queue *q,
 		ret = PTR_ERR(blkg);
 		goto out_unlock;
 	}
-	q->root_blkg = blkg;
-	q->root_rl.blkg = blkg;
 
 	list_for_each_entry(blkg, &q->blkg_list, q_node)
 		cnt++;