- * Unmap a rq previously mapped by blk_rq_map_user().
- * rq->bio must be set to the original head of the request.
+ * Unmap a rq previously mapped by blk_rq_map_user(). The caller must
+ * supply the original rq->bio from the blk_rq_map_user() return, since
+ * the io completion may have changed rq->bio.