Add support for blkio cgroups on Linux

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index 214fbd2..aa5124c 100644
--- a/fio.h
+++ b/fio.h
@@ -271,6 +271,14 @@
 	 * Benchmark profile type
 	 */
 	unsigned int profile;
+
+	/*
+	 * blkio cgroup support
+	 */
+	char *cgroup_root;
+	char *cgroup;
+	unsigned int cgroup_weight;
+	unsigned int cgroup_was_created;
 };
 
 #define FIO_VERROR_SIZE	128