@@ -969,6 +969,8 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
 	int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE);
 	void *p;
 
+	ASSERT(stripe_len == BTRFS_STRIPE_LEN);
+
 	rbio = kzalloc(sizeof(*rbio) +
 		       sizeof(*rbio->stripe_pages) * num_pages +
 		       sizeof(*rbio->bio_pages) * num_pages +

@@ -1725,6 +1727,9 @@ int raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc,
 	struct blk_plug_cb *cb;
 	int ret;
 
+	/* Currently we only support fixed stripe len */
+	ASSERT(stripe_len == BTRFS_STRIPE_LEN);
+
 	rbio = alloc_rbio(fs_info, bioc, stripe_len);
 	if (IS_ERR(rbio)) {
 		btrfs_put_bioc(bioc);

@@ -2122,6 +2127,9 @@ int raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
 	struct btrfs_raid_bio *rbio;
 	int ret;
 
+	/* Currently we only support fixed stripe len */
+	ASSERT(stripe_len == BTRFS_STRIPE_LEN);
+
 	if (generic_io) {
 		ASSERT(bioc->mirror_num == mirror_num);
 		btrfs_bio(bio)->mirror_num = mirror_num;

@@ -2671,12 +2679,12 @@ void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
 
 struct btrfs_raid_bio *
 raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc,
-			  u64 length)
+			  u64 stripe_len)
 {
 	struct btrfs_fs_info *fs_info = bioc->fs_info;
 	struct btrfs_raid_bio *rbio;
 
-	rbio = alloc_rbio(fs_info, bioc, length);
+	rbio = alloc_rbio(fs_info, bioc, stripe_len);
 	if (IS_ERR(rbio))
 		return NULL;
 

@@ -46,7 +46,7 @@ void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
 
 struct btrfs_raid_bio *
 raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc,
-			  u64 length);
+			  u64 stripe_len);
 void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
 
 int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);

@@ -1229,13 +1229,15 @@ static inline int scrub_nr_raid_mirrors(struct btrfs_io_context *bioc)
 
 static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
 						 u64 *raid_map,
-						 u64 mapped_length,
+						 u64 stripe_len,
 						 int nstripes, int mirror,
 						 int *stripe_index,
 						 u64 *stripe_offset)
 {
 	int i;
 
+	ASSERT(stripe_len == BTRFS_STRIPE_LEN);
+
 	if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 		/* RAID5/6 */
 		for (i = 0; i < nstripes; i++) {

@@ -1244,7 +1246,7 @@ static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
 				continue;
 
 			if (logical >= raid_map[i] &&
-			    logical < raid_map[i] + mapped_length)
+			    logical < raid_map[i] + stripe_len)
 				break;
 		}
 

@@ -1349,7 +1351,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 			scrub_stripe_index_and_offset(logical,
 						      bioc->map_type,
 						      bioc->raid_map,
-						      mapped_length,
+						      bioc->stripe_len,
 						      bioc->num_stripes -
 						      bioc->num_tgtdevs,
 						      mirror_index,

@@ -1401,7 +1403,7 @@ static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
 
 	mirror_num = spage->sblock->pagev[0]->mirror_num;
 	ret = raid56_parity_recover(bio, spage->recover->bioc,
-				    spage->recover->map_length,
+				    spage->recover->bioc->stripe_len,
 				    mirror_num, 0);
 	if (ret)
 		return ret;

@@ -2230,7 +2232,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
 	bio->bi_private = sblock;
 	bio->bi_end_io = scrub_missing_raid56_end_io;
 
-	rbio = raid56_alloc_missing_rbio(bio, bioc, length);
+	rbio = raid56_alloc_missing_rbio(bio, bioc, bioc->stripe_len);
 	if (!rbio)
 		goto rbio_out;
 

@@ -2846,7 +2848,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 	bio->bi_private = sparity;
 	bio->bi_end_io = scrub_parity_bio_endio;
 
-	rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, length,
+	rbio = raid56_parity_alloc_scrub_rbio(bio, bioc, bioc->stripe_len,
 					      sparity->scrub_dev,
 					      sparity->dbitmap,
 					      sparity->nsectors);

@@ -6051,6 +6051,7 @@ static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info,
 		ret = -ENOMEM;
 		goto out;
 	}
+	bioc->stripe_len = map->stripe_len;
 
 	for (i = 0; i < num_stripes; i++) {
 		bioc->stripes[i].physical =

@@ -6406,6 +6407,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 {
 	struct extent_map *em;
 	struct map_lookup *map;
+	const u64 orig_length = *length;
 	u64 stripe_offset;
 	u64 stripe_nr;
 	u64 stripe_len;

@@ -6427,6 +6429,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 
 	ASSERT(bioc_ret);
 	ASSERT(op != BTRFS_MAP_DISCARD);
+	ASSERT(orig_length);
 
 	em = btrfs_get_chunk_map(fs_info, logical, *length);
 	ASSERT(!IS_ERR(em));

@@ -6522,7 +6525,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 			num_stripes = map->num_stripes;
 			max_errors = nr_parity_stripes(map);
 
-			*length = map->stripe_len;
+			/* Return the length to the full stripe end */
+			*length = min(raid56_full_stripe_start + em->start +
+				      data_stripes * stripe_len,
+				      logical + orig_length) - logical;
 			stripe_index = 0;
 			stripe_offset = 0;
 		} else {

@@ -6574,6 +6580,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 		ret = -ENOMEM;
 		goto out;
 	}
+	bioc->stripe_len = map->stripe_len;
 
 	for (i = 0; i < num_stripes; i++) {
 		bioc->stripes[i].physical = map->stripes[stripe_index].physical +

@@ -6824,9 +6831,9 @@ static int submit_one_mapped_range(struct btrfs_fs_info *fs_info, struct bio *bi
 		/* In this case, map_length has been set to the length of
 		   a single stripe; not the whole write */
 		if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
-			ret = raid56_parity_write(bio, bioc, map_length);
+			ret = raid56_parity_write(bio, bioc, bioc->stripe_len);
 		} else {
-			ret = raid56_parity_recover(bio, bioc, map_length,
+			ret = raid56_parity_recover(bio, bioc, bioc->stripe_len,
 						    mirror_num, 1);
 		}
 

@@ -449,6 +449,7 @@ struct btrfs_io_context {
 	struct bio *orig_bio;
 	void *private;
 	atomic_t error;
+	u32 stripe_len;
 	int max_errors;
 	int num_stripes;
 	int mirror_num;