raidz_map
struct raidz_map;
struct raidz_map * vdev_raidz_map_alloc(struct zio *, uint64_t,
void vdev_raidz_map_free(struct raidz_map *);
void vdev_raidz_generate_parity(struct raidz_map *);
int vdev_raidz_reconstruct(struct raidz_map *, const int *, int);
int vdev_raidz_math_generate(struct raidz_map *);
int vdev_raidz_math_reconstruct(struct raidz_map *, const int *,