Deadline iosched: Factor out finding latter reques
Aaron Carroll [Tue, 30 Oct 2007 09:40:12 +0000 (10:40 +0100)]
Factor finding the next request in sector-sorted order into
a function deadline_latter_request.

Signed-off-by: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/deadline-iosched.c

index 1a511ff..a44437e 100644 (file)
@@ -55,6 +55,20 @@ static void deadline_move_request(struct deadline_data *, struct request *);
 
 #define RQ_RB_ROOT(dd, rq)     (&(dd)->sort_list[rq_data_dir((rq))])
 
+/*
+ * get the request after `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_latter_request(struct request *rq)
+{
+       struct rb_node *node = rb_next(&rq->rb_node);
+
+       if (node)
+               return rb_entry_rq(node);
+
+       return NULL;
+}
+
 static void
 deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
 {
@@ -74,13 +88,8 @@ deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
 {
        const int data_dir = rq_data_dir(rq);
 
-       if (dd->next_rq[data_dir] == rq) {
-               struct rb_node *rbnext = rb_next(&rq->rb_node);
-
-               dd->next_rq[data_dir] = NULL;
-               if (rbnext)
-                       dd->next_rq[data_dir] = rb_entry_rq(rbnext);
-       }
+       if (dd->next_rq[data_dir] == rq)
+               dd->next_rq[data_dir] = deadline_latter_request(rq);
 
        elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
 }
@@ -198,14 +207,11 @@ static void
 deadline_move_request(struct deadline_data *dd, struct request *rq)
 {
        const int data_dir = rq_data_dir(rq);
-       struct rb_node *rbnext = rb_next(&rq->rb_node);
 
        dd->next_rq[READ] = NULL;
        dd->next_rq[WRITE] = NULL;
+       dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-       if (rbnext)
-               dd->next_rq[data_dir] = rb_entry_rq(rbnext);
-       
        dd->last_sector = rq->sector + rq->nr_sectors;
 
        /*