mmc: block: Fix in_flight[issue_type] value error

commit 4b430d4 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: 8119697 ("mmc: block: Add blk-mq support")
Cc: [email protected]
Signed-off-by: Yibin Ding <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

drivers/mmc/core/block.c

@@ -2097,14 +2097,14 @@ 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, enum mmc_issue_type issue_type)
 {
 	unsigned long flags;
 	bool put_card;
 
 	spin_lock_irqsave(&mq->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);
 
@@ -2117,6 +2117,7 @@ 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,
 				bool can_sleep)
 {
+	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;
@@ -2136,7 +2137,7 @@ static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req,
 			blk_mq_complete_request(req);
 	}
 
-	mmc_blk_mq_dec_in_flight(mq, req);
+	mmc_blk_mq_dec_in_flight(mq, issue_type);
 }
 
 void mmc_blk_mq_recovery(struct mmc_queue *mq)