Deadline iosched: Factor out finding latter reques

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>

1 files changed, 17 insertions, 11 deletions

diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 1a511ffaf8a4..a44437e5a94b 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -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;
 
         /*