diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 3327192bb71f..c8fb886aebd4 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3038,6 +3038,17 @@ static bool rbd_obj_advance_read(struct rbd_obj_request *obj_req, int *result) } return true; case RBD_OBJ_READ_PARENT: + /* + * The parent image is read only up to the overlap -- zero-fill + * from the overlap to the end of the request. + */ + if (!*result) { + u32 obj_overlap = rbd_obj_img_extents_bytes(obj_req); + + if (obj_overlap < obj_req->ex.oe_len) + rbd_obj_zero_range(obj_req, obj_overlap, + obj_req->ex.oe_len - obj_overlap); + } return true; default: BUG();