partition_group
static void partition_struct(tree *fields, unsigned long length, struct partition_group *size_groups, unsigned long *num_groups)
memset(size_groups, 0, sizeof(struct partition_group) * length);
struct partition_group size_group[length];
partition_struct(newtree, length, (struct partition_group *)&size_group, &num_groups);
struct partition_group tmp;