mdb_zfs_btree_core_t
mdb_zfs_btree_core_t *node = (mdb_zfs_btree_core_t *)buf;
mdb_zfs_btree_core_t *node =
(mdb_zfs_btree_core_t *)bwd->bwd_node;
mdb_zfs_btree_core_t *node = (mdb_zfs_btree_core_t *)bwd->bwd_node;
offsetof(mdb_zfs_btree_core_t, btc_elems) + bwd->bwd_offset *