vfsync
int vfsync(struct vnode *vp, int waitfor, int passes,
error = vfsync(vp, ap->a_waitfor, 10000, NULL, NULL);
error = vfsync(vp, 0, 1, NULL, NULL);
vfsync(ap->a_vp, ap->a_waitfor, 1, NULL, NULL);
vfsync(vp, ap->a_waitfor, 1, NULL, NULL);
vfsync(ap->a_vp, waitfor, 1, NULL, NULL);
vfsync(vp, MNT_WAIT, 1, NULL, NULL);
vfsync(vp, ap->a_waitfor, 1, NULL, NULL);
vfsync(vp, ap->a_waitfor, 0, NULL, NULL);
vfsync(vp, ap->a_waitfor, 0, NULL, NULL);
vfsync(ap->a_vp, ap->a_waitfor, 1, NULL, NULL);
error = vfsync(vp, ap->a_waitfor, UFS_NIADDR + 1, ffs_checkdeferred,
vfsync(vp, MNT_WAIT, 1, NULL, NULL);
vfsync(vp, ap->a_waitfor, 1, NULL, NULL);