extern int Restore_metadata(char *dev, char *dir, struct context *c,
struct supertype *st, int only);
+int md_array_valid(int fd);
int md_array_active(int fd);
int md_get_array_info(int fd, struct mdu_array_info_s *array);
int md_set_array_info(int fd, struct mdu_array_info_s *array);