3 files changed, 7 insertions, 5 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 5fe03def34b2..2cc682b860ea 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 838834be115b..5f127cfb2e92 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 44bf6d11197e..d48a1dfd7b24 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