block: prepare elevator to use REQ_OPs.

This patch converts the elevator code to use separate variables
for the operation and flags, and to check req_op for the REQ_OP.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4a34978..3fcc598 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -4285,7 +4285,7 @@
 	return ELV_MQUEUE_MAY;
 }
 
-static int cfq_may_queue(struct request_queue *q, int rw)
+static int cfq_may_queue(struct request_queue *q, int op, int op_flags)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct task_struct *tsk = current;
@@ -4302,7 +4302,7 @@
 	if (!cic)
 		return ELV_MQUEUE_MAY;
 
-	cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
+	cfqq = cic_to_cfqq(cic, rw_is_sync(op | op_flags));
 	if (cfqq) {
 		cfq_init_prio_data(cfqq, cic);