diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 5fe03def34b24c396f299aa57bda4b1cc5a3df2a..2cc682b860ead9d15350620c595bfbb30f4a533d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -286,16 +286,16 @@ done:
 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);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 838834be115b3f341f3bc6e0eba54a5c3fcc424c..5f127cfb2e924baf06f77ae95d1832e13048cee4 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3694,8 +3694,10 @@ static void *cfq_init_queue(struct request_queue *q)
 	 * to make sure that cfq_put_cfqg() does not try to kfree root group
 	 */
 	atomic_set(&cfqg->ref, 1);
+	rcu_read_lock();
 	blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd,
 					0);
+	rcu_read_unlock();
 #endif
 	/*
 	 * Not strictly needed (since RB_ROOT just clears the node and we
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 44bf6d11197e7bbad72f511ba36fba23747be68e..d48a1dfd7b2455cdb2b7b7f0df0af282c6c5a695 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -235,7 +235,7 @@ void drbd_endio_pri(struct bio *bio, int error)
 	if (unlikely(error)) {
 		what = (bio_data_dir(bio) == WRITE)
 			? write_completed_with_error
-			: (bio_rw(bio) == READA)
+			: (bio_rw(bio) == READ)
 			  ? read_completed_with_error
 			  : read_ahead_completed_with_error;
 	} else