blk-mq: enable checking two part inflight counts at the same time

Modify blk_mq_in_flight() to count both a partition and root at
the same time. Then we only have to call it once, instead of
potentially looping the tags twice.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 8 insertions, 4 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0dfc7a9..fe764ca 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -97,11 +97,15 @@ static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
 	if (test_bit(REQ_ATOM_STARTED, &rq->atomic_flags) &&
 	    !test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) {
 		/*
-		 * Count as inflight if it either matches the partition we
-		 * asked for, or if it's the root
+		 * index[0] counts the specific partition that was asked
+		 * for. index[1] counts the ones that are active on the
+		 * whole device, so increment that if mi->part is indeed
+		 * a partition, and not a whole device.
 		 */
-		if (rq->part == mi->part || mi->part->partno)
+		if (rq->part == mi->part)
 			mi->inflight[0]++;
+		if (mi->part->partno)
+			mi->inflight[1]++;
 	}
 }
 
@@ -110,7 +114,7 @@ void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 {
 	struct mq_inflight mi = { .part = part, .inflight = inflight, };
 
-	inflight[0] = 0;
+	inflight[0] = inflight[1] = 0;
 	blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
 }