Merge branch 'blkcg-cfq-hierarchy' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup into for-3.9/core

Tejun writes:

Hello, Jens.

Please consider pulling from the following branch to receive cfq blkcg
hierarchy support.  The branch is based on top of v3.8-rc2.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git blkcg-cfq-hierarchy

The patchset was reviewd in the following thread.

  http://thread.gmane.org/gmane.linux.kernel.cgroups/5571

include/linux/blkdev.h

@@ -19,6 +19,7 @@
 #include <linux/gfp.h>
 #include <linux/bsg.h>
 #include <linux/smp.h>
+#include <linux/rcupdate.h>
 
 #include <asm/scatterlist.h>
 
@@ -437,6 +438,7 @@ struct request_queue {
 	/* Throttle data */
 	struct throtl_data *td;
 #endif
+	struct rcu_head		rcu_head;
 };
 
 #define QUEUE_FLAG_QUEUED	1	/* uses generic tag queueing */