blk-mq: provide internal in-flight variant
We don't have to inc/dec some counter, since we can just
iterate the tags. That makes inc/dec a noop, but means we
have to iterate busy tags to get an in-flight count.
Reviewed-by: Bart Van Assche <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a5d369d..0dfc7a9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -83,6 +83,37 @@ static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
}
+struct mq_inflight {
+ struct hd_struct *part;
+ unsigned int *inflight;
+};
+
+static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, void *priv,
+ bool reserved)
+{
+ struct mq_inflight *mi = priv;
+
+ 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
+ */
+ if (rq->part == mi->part || mi->part->partno)
+ mi->inflight[0]++;
+ }
+}
+
+void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
+ unsigned int inflight[2])
+{
+ struct mq_inflight mi = { .part = part, .inflight = inflight, };
+
+ inflight[0] = 0;
+ blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
+}
+
void blk_freeze_queue_start(struct request_queue *q)
{
int freeze_depth;
