- * Does the target need to split even further?
- * - q->limits.chunk_sectors reflects ti->max_io_len so
- * blk_max_size_offset() provides required splitting.
- * - blk_max_size_offset() also respects q->limits.max_sectors
+ * Does the target need to split IO even further?
+ * - varied (per target) IO splitting is a tenet of DM; this
+ * explains why stacked chunk_sectors based splitting via
+ * blk_max_size_offset() isn't possible here. So pass in
+ * ti->max_io_len to override stacked chunk_sectors.