1 files changed, 30 insertions, 15 deletions

diff --git a/block/blk.h b/block/blk.h
index d6b911ac002c..d6586287adc9 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -18,8 +18,6 @@ int blk_rq_append_bio(struct request_queue *q, struct request *rq,
 void blk_dequeue_request(struct request *rq);
 void __blk_queue_free_tags(struct request_queue *q);
 
-void blk_unplug_work(struct work_struct *work);
-void blk_unplug_timeout(unsigned long data);
 void blk_rq_timed_out_timer(unsigned long data);
 void blk_delete_timer(struct request *);
 void blk_add_timer(struct request *);
@@ -34,7 +32,7 @@ enum rq_atomic_flags {
 
 /*
  * EH timer and IO completion will both attempt to 'grab' the request, make
- * sure that only one of them suceeds
+ * sure that only one of them succeeds
  */
 static inline int blk_mark_rq_complete(struct request *rq)
 {
@@ -51,18 +49,41 @@ static inline void blk_clear_rq_complete(struct request *rq)
  */
 #define ELV_ON_HASH(rq)         (!hlist_unhashed(&(rq)->hash))
 
+void blk_insert_flush(struct request *rq);
+void blk_abort_flushes(struct request_queue *q);
+
 static inline struct request *__elv_next_request(struct request_queue *q)
 {
         struct request *rq;
 
         while (1) {
-                while (!list_empty(&q->queue_head)) {
+                if (!list_empty(&q->queue_head)) {
                         rq = list_entry_rq(q->queue_head.next);
-                        if (blk_do_ordered(q, &rq))
-                                return rq;
+                        return rq;
                 }
 
-                if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
+                /*
+                 * Flush request is running and flush request isn't queueable
+                 * in the drive, we can hold the queue till flush request is
+                 * finished. Even we don't do this, driver can't dispatch next
+                 * requests and will requeue them. And this can improve
+                 * throughput too. For example, we have request flush1, write1,
+                 * flush 2. flush1 is dispatched, then queue is hold, write1
+                 * isn't inserted to queue. After flush1 is finished, flush2
+                 * will be dispatched. Since disk cache is already clean,
+                 * flush2 will be finished very soon, so looks like flush2 is
+                 * folded to flush1.
+                 * Since the queue is hold, a flag is set to indicate the queue
+                 * should be restarted later. Please see flush_end_io() for
+                 * details.
+                 */
+                if (q->flush_pending_idx != q->flush_running_idx &&
+                                !queue_flush_queueable(q)) {
+                        q->flush_queue_delayed = 1;
+                        return NULL;
+                }
+                if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
+                    !q->elevator->ops->elevator_dispatch_fn(q, 0))
                         return NULL;
         }
 }
@@ -103,6 +124,8 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
                       struct bio *bio);
 int attempt_back_merge(struct request_queue *q, struct request *rq);
 int attempt_front_merge(struct request_queue *q, struct request *rq);
+int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
+                                struct request *next);
 void blk_recalc_rq_segments(struct request *rq);
 void blk_rq_set_mixed_merge(struct request *rq);
 
@@ -132,14 +155,6 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
         return q->nr_congestion_off;
 }
 
-#if defined(CONFIG_BLK_DEV_INTEGRITY)
-
-#define rq_for_each_integrity_segment(bvl, _rq, _iter)          \
-        __rq_for_each_bio(_iter.bio, _rq)                       \
-                bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
-
-#endif /* BLK_DEV_INTEGRITY */
-
 static inline int blk_cpu_to_group(int cpu)
 {
         int group = NR_CPUS;