unionfs_forward_vop_start_pair
void unionfs_forward_vop_start_pair(struct vnode *, int *,
unionfs_forward_vop_start_pair(basevp, lkflags, NULL, NULL);
unionfs_forward_vop_start_pair(udvp, &udvp_lkflags,
unionfs_forward_vop_start_pair(udvp, &udvp_lkflags,
unionfs_forward_vop_start_pair(udvp, &udvp_lkflags,