block: change the tag sync vs async restriction logic

Make them fully share the tag space, but disallow async requests using
the last any two slots.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/block/elevator.c b/block/elevator.c
index 918920056e42..ebee948293eb 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -546,7 +546,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq)
          * in_flight count again
          */
         if (blk_account_rq(rq)) {
-                q->in_flight--;
+                q->in_flight[rq_is_sync(rq)]--;
                 if (blk_sorted_rq(rq))
                         elv_deactivate_rq(q, rq);
         }
@@ -685,7 +685,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
 
         if (unplug_it && blk_queue_plugged(q)) {
                 int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC]
-                        - q->in_flight;
+                                - queue_in_flight(q);
 
                 if (nrq >= q->unplug_thresh)
                         __generic_unplug_device(q);
@@ -823,7 +823,7 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
          * request is released from the driver, io must be done
          */
         if (blk_account_rq(rq)) {
-                q->in_flight--;
+                q->in_flight[rq_is_sync(rq)]--;
                 if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
                         e->ops->elevator_completed_req_fn(q, rq);
         }
@@ -838,7 +838,7 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
                 if (!list_empty(&q->queue_head))
                         next = list_entry_rq(q->queue_head.next);
 
-                if (!q->in_flight &&
+                if (!queue_in_flight(q) &&
                     blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
                     (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
                         blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);