[PATCH] generic dispatch fixes

- Split elv_dispatch_insert() into two functions
- Rename rq_last_sector() to rq_end_sector()

Signed-off-by: Jens Axboe <axboe@suse.de>

3 files changed, 27 insertions, 23 deletions

diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index a27555908d35..237e43d760c8 100644
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -40,11 +40,6 @@
 static DEFINE_SPINLOCK(elv_list_lock);
 static LIST_HEAD(elv_list);
 
-static inline sector_t rq_last_sector(struct request *rq)
-{
-        return rq->sector + rq->nr_sectors;
-}
-
 /*
  * can we safely merge with this request?
  */
@@ -148,7 +143,7 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e,
         INIT_LIST_HEAD(&q->queue_head);
         q->last_merge = NULL;
         q->elevator = eq;
-        q->last_sector = 0;
+        q->end_sector = 0;
         q->boundary_rq = NULL;
         q->max_back_kb = 0;
 
@@ -233,29 +228,25 @@ void elevator_exit(elevator_t *e)
         kfree(e);
 }
 
+void elv_dispatch_insert_tail(request_queue_t *q, struct request *rq)
+{
+}
+
 /*
  * Insert rq into dispatch queue of q.  Queue lock must be held on
  * entry.  If sort != 0, rq is sort-inserted; otherwise, rq will be
  * appended to the dispatch queue.  To be used by specific elevators.
  */
-void elv_dispatch_insert(request_queue_t *q, struct request *rq, int sort)
+void elv_dispatch_sort(request_queue_t *q, struct request *rq)
 {
         sector_t boundary;
         unsigned max_back;
         struct list_head *entry;
 
-        if (!sort) {
-                /* Specific elevator is performing sort.  Step away. */
-                q->last_sector = rq_last_sector(rq);
-                q->boundary_rq = rq;
-                list_add_tail(&rq->queuelist, &q->queue_head);
-                return;
-        }
-
-        boundary = q->last_sector;
+        boundary = q->end_sector;
         max_back = q->max_back_kb * 2;
         boundary = boundary > max_back ? boundary - max_back : 0;
-
+        
         list_for_each_prev(entry, &q->queue_head) {
                 struct request *pos = list_entry_rq(entry);
 
@@ -343,10 +334,10 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
                         where = ELEVATOR_INSERT_BACK;
 
                 /*
-                 * this request is scheduling boundary, update last_sector
+                 * this request is scheduling boundary, update end_sector
                  */
                 if (blk_fs_request(rq)) {
-                        q->last_sector = rq_last_sector(rq);
+                        q->end_sector = rq_end_sector(rq);
                         q->boundary_rq = rq;
                 }
         }
@@ -479,7 +470,7 @@ struct request *elv_next_request(request_queue_t *q)
                         q->last_merge = NULL;
 
                 if (!q->boundary_rq || q->boundary_rq == rq) {
-                        q->last_sector = rq_last_sector(rq);
+                        q->end_sector = rq_end_sector(rq);
                         q->boundary_rq = NULL;
                 }
 
@@ -802,7 +793,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
         return len;
 }
 
-EXPORT_SYMBOL(elv_dispatch_insert);
+EXPORT_SYMBOL(elv_dispatch_sort);
 EXPORT_SYMBOL(elv_add_request);
 EXPORT_SYMBOL(__elv_add_request);
 EXPORT_SYMBOL(elv_requeue_request);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2c7b9154927a..a2e496f285a4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -337,7 +337,7 @@ struct request_queue
         /*
          * Dispatch queue sorting
          */
-        sector_t                last_sector;
+        sector_t                end_sector;
         struct request          *boundary_rq;
         unsigned int            max_back_kb;
 
@@ -625,6 +625,17 @@ static inline void blkdev_dequeue_request(struct request *req)
 }
 
 /*
+ * This should be in elevator.h, but that requires pulling in rq and q
+ */
+static inline void elv_dispatch_add_tail(struct request_queue *q,
+                                         struct request *rq)
+{
+        q->end_sector = rq_end_sector(rq);
+        q->boundary_rq = rq;
+        list_add_tail(&rq->queuelist, &q->queue_head);
+}
+
+/*
  * Access functions for manipulating queue properties
  */
 extern request_queue_t *blk_init_queue_node(request_fn_proc *rfn,
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 76f4f6920744..f9b5ec38121a 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -79,7 +79,7 @@ struct elevator_queue
 /*
  * block elevator interface
  */
-extern void elv_dispatch_insert(request_queue_t *, struct request *, int);
+extern void elv_dispatch_sort(request_queue_t *, struct request *);
 extern void elv_add_request(request_queue_t *, struct request *, int, int);
 extern void __elv_add_request(request_queue_t *, struct request *, int, int);
 extern int elv_merge(request_queue_t *, struct request **, struct bio *);
@@ -140,4 +140,6 @@ enum {
         ELV_MQUEUE_MUST,
 };
 
+#define rq_end_sector(rq)       ((rq)->sector + (rq)->nr_sectors)
+
 #endif