[PATCH V2 08/10] blk-mq: pass budget token to dirver via blk_mq_queue_data

[Ming Lei <ming.lei@redhat.com>]

Pass the budget token to driver via blk_mq_queue_dada before calling
.queue_rq(), and prepare for tracing SCSI's device_busy via
sbitmap_queue.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Chaitra P B <chaitra.basappa@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/blk-mq.c         | 25 +++++++++++++------------
 include/linux/blk-mq.h |  1 +
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 43ae2b973d99..013272cad500 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1235,6 +1235,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
 		list_del_init(&rq->queuelist);
 
 		bd.rq = rq;
+		bd.budget_token = budget_token;
 
 		/*
 		 * Flag last if we have no more requests, or if we have more
@@ -1778,14 +1779,11 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 }
 
 static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
-					    struct request *rq,
-					    blk_qc_t *cookie, bool last)
+					    struct blk_mq_queue_data *bd,
+					    blk_qc_t *cookie)
 {
+	struct request *rq = bd->rq;
 	struct request_queue *q = rq->q;
-	struct blk_mq_queue_data bd = {
-		.rq = rq,
-		.last = last,
-	};
 	blk_qc_t new_cookie;
 	blk_status_t ret;
 
@@ -1796,7 +1794,7 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
 	 * Any other error (busy), just add it to our list as we
 	 * previously would have done.
 	 */
-	ret = q->mq_ops->queue_rq(hctx, &bd);
+	ret = q->mq_ops->queue_rq(hctx, bd);
 	switch (ret) {
 	case BLK_STS_OK:
 		blk_mq_update_dispatch_busy(hctx, false);
@@ -1823,7 +1821,10 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 {
 	struct request_queue *q = rq->q;
 	bool run_queue = true;
-	int budget_token;
+	struct blk_mq_queue_data bd = {
+		.rq = rq,
+		.last = last,
+	};
 
 	/*
 	 * RCU or SRCU read lock is needed before checking quiesced flag.
@@ -1841,16 +1842,16 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 	if (q->elevator && !bypass_insert)
 		goto insert;
 
-	budget_token = blk_mq_get_dispatch_budget(hctx);
-	if (budget_token < 0)
+	bd.budget_token = blk_mq_get_dispatch_budget(hctx);
+	if (bd.budget_token < 0)
 		goto insert;
 
 	if (!blk_mq_get_driver_tag(rq)) {
-		blk_mq_put_dispatch_budget(hctx, budget_token);
+		blk_mq_put_dispatch_budget(hctx, bd.budget_token);
 		goto insert;
 	}
 
-	return __blk_mq_issue_directly(hctx, rq, cookie, last);
+	return __blk_mq_issue_directly(hctx, &bd, cookie);
 insert:
 	if (bypass_insert)
 		return BLK_STS_RESOURCE;
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 6fd8d7cfe158..42b59b97bfd8 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -259,6 +259,7 @@ struct blk_mq_tag_set {
  */
 struct blk_mq_queue_data {
 	struct request *rq;
+	int budget_token;
 	bool last;
 };
 
-- 
2.20.1