get_part_metadata
md = get_part_metadata(bootpartname, 0);
md = get_part_metadata(gp->lg_name, 0);
md = get_part_metadata(pp->lg_name, 0);
get_part_metadata(lg_name, 1)->bootcode = 1;
md = get_part_metadata(name, 1);
md = get_part_metadata(ppi->lg_name, 0);
struct partition_metadata *get_part_metadata(const char *name, int create);