diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8e6174c..a1177e1 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1123,8 +1123,13 @@ struct clone_info {
 
 static void bio_setup_sector(struct bio *bio, sector_t sector, sector_t len)
 {
-	bio->bi_iter.bi_sector = sector;
-	bio->bi_iter.bi_size = to_bytes(len);
+	if (len) {
+		bio->bi_iter.bi_sector = sector;
+		bio->bi_iter.bi_size = to_bytes(len);
+	} else {
+		bio->bi_iter.bi_size = 0;
+		bio->bi_vcnt = 0;
+	}
 }
 
 /*
@@ -1178,8 +1183,7 @@ static void __clone_and_map_simple_bio(struct clone_info *ci,
 	 * and discard, so no need for concern about wasted bvec allocations.
 	 */
 	 __bio_clone(clone, ci->bio);
-	if (len)
-		bio_setup_sector(clone, ci->sector, len);
+	bio_setup_sector(clone, ci->sector, len);
 
 	__map_bio(tio);
 }