Merge branch 'generic-dispatch' of git://brick.kernel.dk/data/git/linux-2.6-block

1 files changed, 22 insertions, 4 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1afbdb2d752c..fffe163316aa 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -203,6 +203,7 @@ struct request {
 enum rq_flag_bits {
         __REQ_RW,               /* not set, read. set, write */
         __REQ_FAILFAST,         /* no low level driver retries */
+        __REQ_SORTED,           /* elevator knows about this request */
         __REQ_SOFTBARRIER,      /* may not be passed by ioscheduler */
         __REQ_HARDBARRIER,      /* may not be passed by drive either */
         __REQ_CMD,              /* is a regular fs rw request */
@@ -235,6 +236,7 @@ enum rq_flag_bits {
 
 #define REQ_RW          (1 << __REQ_RW)
 #define REQ_FAILFAST    (1 << __REQ_FAILFAST)
+#define REQ_SORTED      (1 << __REQ_SORTED)
 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER)
 #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER)
 #define REQ_CMD         (1 << __REQ_CMD)
@@ -333,6 +335,12 @@ struct request_queue
         end_flush_fn            *end_flush_fn;
 
         /*
+         * Dispatch queue sorting
+         */
+        sector_t                end_sector;
+        struct request          *boundary_rq;
+
+        /*
          * Auto-unplugging state
          */
         struct timer_list       unplug_timer;
@@ -454,6 +462,7 @@ enum {
 #define blk_pm_request(rq)      \
         ((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
 
+#define blk_sorted_rq(rq)       ((rq)->flags & REQ_SORTED)
 #define blk_barrier_rq(rq)      ((rq)->flags & REQ_HARDBARRIER)
 #define blk_barrier_preflush(rq)        ((rq)->flags & REQ_BAR_PREFLUSH)
 #define blk_barrier_postflush(rq)       ((rq)->flags & REQ_BAR_POSTFLUSH)
@@ -611,12 +620,21 @@ extern void end_request(struct request *req, int uptodate);
 
 static inline void blkdev_dequeue_request(struct request *req)
 {
-        BUG_ON(list_empty(&req->queuelist));
+        elv_dequeue_request(req->q, req);
+}
 
-        list_del_init(&req->queuelist);
+/*
+ * 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)
+{
+        if (q->last_merge == rq)
+                q->last_merge = NULL;
 
-        if (req->rl)
-                elv_remove_request(req->q, req);
+        q->end_sector = rq_end_sector(rq);
+        q->boundary_rq = rq;
+        list_add_tail(&rq->queuelist, &q->queue_head);
 }
 
 /*