1 files changed, 14 insertions, 9 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index ae61a9c2fc..8534c35e04 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -377,6 +377,7 @@ struct bio *__bio_split_to_limits(struct bio *bio,
 		blkcg_bio_issue_init(split);
 		bio_chain(split, bio);
 		trace_block_split(split, bio->bi_iter.bi_sector);
+		WARN_ON_ONCE(bio_zone_write_plugging(bio));
 		submit_bio_noacct(bio);
 		return split;
 	}
@@ -974,13 +975,7 @@ static void blk_account_io_merge_bio(struct request *req)
 	part_stat_unlock();
 }
 
-enum bio_merge_status {
-	BIO_MERGE_OK,
-	BIO_MERGE_NONE,
-	BIO_MERGE_FAILED,
-};
-
-static enum bio_merge_status bio_attempt_back_merge(struct request *req,
+enum bio_merge_status bio_attempt_back_merge(struct request *req,
 		struct bio *bio, unsigned int nr_segs)
 {
 	const blk_opf_t ff = bio_failfast(bio);
@@ -996,6 +991,9 @@ static enum bio_merge_status bio_attempt_back_merge(struct request *req,
 
 	blk_update_mixed_merge(req, bio, false);
 
+	if (req->rq_flags & RQF_ZONE_WRITE_PLUGGING)
+		blk_zone_write_plug_bio_merged(bio);
+
 	req->biotail->bi_next = bio;
 	req->biotail = bio;
 	req->__data_len += bio->bi_iter.bi_size;
@@ -1011,6 +1009,14 @@ static enum bio_merge_status bio_attempt_front_merge(struct request *req,
 {
 	const blk_opf_t ff = bio_failfast(bio);
 
+	/*
+	 * A front merge for writes to sequential zones of a zoned block device
+	 * can happen only if the user submitted writes out of order. Do not
+	 * merge such write to let it fail.
+	 */
+	if (req->rq_flags & RQF_ZONE_WRITE_PLUGGING)
+		return BIO_MERGE_FAILED;
+
 	if (!ll_front_merge_fn(req, bio, nr_segs))
 		return BIO_MERGE_FAILED;
 
@@ -1109,10 +1115,9 @@ static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q,
 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 		unsigned int nr_segs)
 {
-	struct blk_plug *plug;
+	struct blk_plug *plug = current->plug;
 	struct request *rq;
 
-	plug = blk_mq_plug(bio);
 	if (!plug || rq_list_empty(plug->mq_list))
 		return false;