1 files changed, 33 insertions, 2 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 64bf7d9dd8e8..1ac782fdc55c 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -758,6 +758,33 @@ void blk_rq_set_mixed_merge(struct request *rq)
 	rq->rq_flags |= RQF_MIXED_MERGE;
 }
 
+static inline blk_opf_t bio_failfast(const struct bio *bio)
+{
+	if (bio->bi_opf & REQ_RAHEAD)
+		return REQ_FAILFAST_MASK;
+
+	return bio->bi_opf & REQ_FAILFAST_MASK;
+}
+
+/*
+ * After we are marked as MIXED_MERGE, any new RA bio has to be updated
+ * as failfast, and request's failfast has to be updated in case of
+ * front merge.
+ */
+static inline void blk_update_mixed_merge(struct request *req,
+		struct bio *bio, bool front_merge)
+{
+	if (req->rq_flags & RQF_MIXED_MERGE) {
+		if (bio->bi_opf & REQ_RAHEAD)
+			bio->bi_opf |= REQ_FAILFAST_MASK;
+
+		if (front_merge) {
+			req->cmd_flags &= ~REQ_FAILFAST_MASK;
+			req->cmd_flags |= bio->bi_opf & REQ_FAILFAST_MASK;
+		}
+	}
+}
+
 static void blk_account_io_merge_request(struct request *req)
 {
 	if (blk_do_io_stat(req)) {
@@ -955,7 +982,7 @@ enum bio_merge_status {
 static enum bio_merge_status bio_attempt_back_merge(struct request *req,
 		struct bio *bio, unsigned int nr_segs)
 {
-	const blk_opf_t ff = bio->bi_opf & REQ_FAILFAST_MASK;
+	const blk_opf_t ff = bio_failfast(bio);
 
 	if (!ll_back_merge_fn(req, bio, nr_segs))
 		return BIO_MERGE_FAILED;
@@ -966,6 +993,8 @@ static enum bio_merge_status bio_attempt_back_merge(struct request *req,
 	if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
 		blk_rq_set_mixed_merge(req);
 
+	blk_update_mixed_merge(req, bio, false);
+
 	req->biotail->bi_next = bio;
 	req->biotail = bio;
 	req->__data_len += bio->bi_iter.bi_size;
@@ -979,7 +1008,7 @@ static enum bio_merge_status bio_attempt_back_merge(struct request *req,
 static enum bio_merge_status bio_attempt_front_merge(struct request *req,
 		struct bio *bio, unsigned int nr_segs)
 {
-	const blk_opf_t ff = bio->bi_opf & REQ_FAILFAST_MASK;
+	const blk_opf_t ff = bio_failfast(bio);
 
 	if (!ll_front_merge_fn(req, bio, nr_segs))
 		return BIO_MERGE_FAILED;
@@ -990,6 +1019,8 @@ static enum bio_merge_status bio_attempt_front_merge(struct request *req,
 	if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
 		blk_rq_set_mixed_merge(req);
 
+	blk_update_mixed_merge(req, bio, true);
+
 	bio->bi_next = req->bio;
 	req->bio = bio;