block: share request flush fields with elevator_private

Flush requests are never put on the IO scheduler.  Convert request
structure's elevator_private* into an array and have the flush fields
share a union with it.

Reclaim the space lost in 'struct request' by moving 'completion_data'
back in the union with 'rb_node'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4cd59b0d7c15..968455c57e1a 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -54,9 +54,9 @@ static const int cfq_hist_divisor = 4;
 #define CFQQ_SEEKY(cfqq)        (hweight32(cfqq->seek_history) > 32/8)
 
 #define RQ_CIC(rq)              \
-        ((struct cfq_io_context *) (rq)->elevator_private)
-#define RQ_CFQQ(rq)             (struct cfq_queue *) ((rq)->elevator_private2)
-#define RQ_CFQG(rq)             (struct cfq_group *) ((rq)->elevator_private3)
+        ((struct cfq_io_context *) (rq)->elevator_private[0])
+#define RQ_CFQQ(rq)             (struct cfq_queue *) ((rq)->elevator_private[1])
+#define RQ_CFQG(rq)             (struct cfq_group *) ((rq)->elevator_private[2])
 
 static struct kmem_cache *cfq_pool;
 static struct kmem_cache *cfq_ioc_pool;
@@ -3589,12 +3589,12 @@ static void cfq_put_request(struct request *rq)
 
                 put_io_context(RQ_CIC(rq)->ioc);
 
-                rq->elevator_private = NULL;
-                rq->elevator_private2 = NULL;
+                rq->elevator_private[0] = NULL;
+                rq->elevator_private[1] = NULL;
 
                 /* Put down rq reference on cfqg */
                 cfq_put_cfqg(RQ_CFQG(rq));
-                rq->elevator_private3 = NULL;
+                rq->elevator_private[2] = NULL;
 
                 cfq_put_queue(cfqq);
         }
@@ -3685,9 +3685,9 @@ new_queue:
 
         spin_unlock_irqrestore(q->queue_lock, flags);
 
-        rq->elevator_private = cic;
-        rq->elevator_private2 = cfqq;
-        rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg);
+        rq->elevator_private[0] = cic;
+        rq->elevator_private[1] = cfqq;
+        rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg);
         return 0;
 
 queue_fail: