block: make part_in_flight() take an array of two ints

Instead of returning the count that matches the partition, pass
in an array of two ints. Index 0 will be filled with the inflight
count for the partition in question, and index 1 will filled
with the root inflight count, if the partition passed in is not the
root.

This is in preparation for being able to calculate both in one
go.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 4 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 8ee954c12e9d..6ad2b8602c1d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1472,15 +1472,15 @@ static void add_acct_request(struct request_queue *q, struct request *rq,
 static void part_round_stats_single(struct request_queue *q, int cpu,
 				    struct hd_struct *part, unsigned long now)
 {
-	int inflight;
+	int inflight[2];
 
 	if (now == part->stamp)
 		return;
 
-	inflight = part_in_flight(q, part);
-	if (inflight) {
+	part_in_flight(q, part, inflight);
+	if (inflight[0]) {
 		__part_stat_add(cpu, part, time_in_queue,
-				inflight * (now - part->stamp));
+				inflight[0] * (now - part->stamp));
 		__part_stat_add(cpu, part, io_ticks, (now - part->stamp));
 	}
 	part->stamp = now;