nilfs_dir_attach
int nilfs_dir_attach(struct nilfs_mount *ump, struct nilfs_node *dir_node, struct nilfs_node *nilfs_node, struct vattr *vap, struct componentname *cnp);
error = nilfs_dir_attach(dir_node->ump, dir_node, nilfs_node,
error = nilfs_dir_attach(tdnode->ump, tdnode, fnode, &fvap, tcnp);