[PATCH 4.19] mmc: block: Fix in_flight[issue_type] value error

[Adrian Hunter <adrian.hunter@intel.com>]

From: Yibin Ding <yibin.ding@unisoc.com>

commit 4b430d4ac99750ee2ae2f893f1055c7af1ec3dc5 upstream.

For a completed request, after the mmc_blk_mq_complete_rq(mq, req)
function is executed, the bitmap_tags corresponding to the
request will be cleared, that is, the request will be regarded as
idle. If the request is acquired by a different type of process at
this time, the issue_type of the request may change. It further
caused the value of mq->in_flight[issue_type] to be abnormal,
and a large number of requests could not be sent.

p1:					      p2:
mmc_blk_mq_complete_rq
  blk_mq_free_request
					      blk_mq_get_request
					        blk_mq_rq_ctx_init
mmc_blk_mq_dec_in_flight
  mmc_issue_type(mq, req)

This strategy can ensure the consistency of issue_type
before and after executing mmc_blk_mq_complete_rq.

Fixes: 81196976ed94 ("mmc: block: Add blk-mq support")
Cc: stable@vger.kernel.org
Signed-off-by: Yibin Ding <yibin.ding@unisoc.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230802023023.1318134-1-yunlong.xing@unisoc.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
(cherry picked from commit 4b430d4ac99750ee2ae2f893f1055c7af1ec3dc5)
(backport to 4.19.y)
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/block.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 88114e576efb..039058fe6a41 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1976,15 +1976,16 @@ static void mmc_blk_mq_poll_completion(struct mmc_queue *mq,
 	mmc_blk_urgent_bkops(mq, mqrq);
 }
 
-static void mmc_blk_mq_dec_in_flight(struct mmc_queue *mq, struct request *req)
+static void mmc_blk_mq_dec_in_flight(struct mmc_queue *mq,
+				     struct request_queue *q,
+				     enum mmc_issue_type issue_type)
 {
-	struct request_queue *q = req->q;
 	unsigned long flags;
 	bool put_card;
 
 	spin_lock_irqsave(q->queue_lock, flags);
 
-	mq->in_flight[mmc_issue_type(mq, req)] -= 1;
+	mq->in_flight[issue_type] -= 1;
 
 	put_card = (mmc_tot_in_flight(mq) == 0);
 
@@ -1996,9 +1997,11 @@ static void mmc_blk_mq_dec_in_flight(struct mmc_queue *mq, struct request *req)
 
 static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req)
 {
+	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
 	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
 	struct mmc_request *mrq = &mqrq->brq.mrq;
 	struct mmc_host *host = mq->card->host;
+	struct request_queue *q = req->q;
 
 	mmc_post_req(host, mrq, 0);
 
@@ -2011,7 +2014,7 @@ static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req)
 	else
 		blk_mq_complete_request(req);
 
-	mmc_blk_mq_dec_in_flight(mq, req);
+	mmc_blk_mq_dec_in_flight(mq, q, issue_type);
 }
 
 void mmc_blk_mq_recovery(struct mmc_queue *mq)
-- 
2.34.1