block: don't call part_{inc,dec}_in_flight for blk-mq devices

part_inc_in_flight and part_dec_in_flight are no-ops for blk-mq queues,
so remove the calls in purely blk-mq callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -1412,7 +1412,6 @@ void blk_account_io_done(struct request *req, u64 now)
 		update_io_ticks(part, jiffies, true);
 		part_stat_inc(part, ios[sgrp]);
 		part_stat_add(part, nsecs[sgrp], now - req->start_time_ns);
-		part_dec_in_flight(req->q, part, rq_data_dir(req));
 
 		hd_struct_put(part);
 		part_stat_unlock();
@@ -1421,25 +1420,15 @@ void blk_account_io_done(struct request *req, u64 now)
 
 void blk_account_io_start(struct request *rq, bool new_io)
 {
-	struct hd_struct *part;
-	int rw = rq_data_dir(rq);
-
 	if (!blk_do_io_stat(rq))
 		return;
 
 	part_stat_lock();
-
-	if (!new_io) {
-		part = rq->part;
-		part_stat_inc(part, merges[rw]);
-	} else {
-		part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
-		part_inc_in_flight(rq->q, part, rw);
-		rq->part = part;
-	}
-
-	update_io_ticks(part, jiffies, false);
-
+	if (!new_io)
+		part_stat_inc(rq->part, merges[rq_data_dir(rq)]);
+	else
+		rq->part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
+	update_io_ticks(rq->part, jiffies, false);
 	part_stat_unlock();
 }
 

block/blk-merge.c

@@ -677,8 +677,6 @@ static void blk_account_io_merge(struct request *req)
 		part_stat_lock();
 		part = req->part;
 
-		part_dec_in_flight(req->q, part, rq_data_dir(req));
-
 		hd_struct_put(part);
 		part_stat_unlock();
 	}