[BLOCK] kill generic max_back_kb handling

This patch kills max_back_kb handling from elv_dispatch_sort() and
kills max_back_kb field from struct request_queue.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

2 files changed, 1 insertions, 6 deletions

diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c
index 415144372c75..af2388e73f61 100644
--- a/drivers/block/elevator.c
+++ b/drivers/block/elevator.c
@@ -136,7 +136,6 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e,
         q->elevator = eq;
         q->end_sector = 0;
         q->boundary_rq = NULL;
-        q->max_back_kb = 0;
 
         if (eq->ops->elevator_init_fn)
                 ret = eq->ops->elevator_init_fn(q, eq);
@@ -227,16 +226,13 @@ void elevator_exit(elevator_t *e)
 void elv_dispatch_sort(request_queue_t *q, struct request *rq)
 {
         sector_t boundary;
-        unsigned max_back;
         struct list_head *entry;
 
         if (q->last_merge == rq)
                 q->last_merge = NULL;
 
         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);
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bd55b1df8997..159dbcd2eb59 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -339,7 +339,6 @@ struct request_queue
          */
         sector_t                end_sector;
         struct request          *boundary_rq;
-        unsigned int            max_back_kb;
 
         /*
          * Auto-unplugging state