block: RCU free request_queue

RCU free request_queue so that blkcg_gq->q can be dereferenced under
RCU lock.  This will be used to implement hierarchical stats.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f94bc83011ed..406343c43cda 100644
--- a/include/linux/blkdev.h
+++ b/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 */