// /var/lib/kubelet too.
func prepareSubpathTarget(mounter mount.Interface, subpath Subpath) (bool, string, error) {
	// Early check for already bind-mounted subpath.
	bindPathTarget := getSubpathBindTarget(subpath)
	notMount, err := mount.IsNotMountPoint(mounter, bindPathTarget)
	if err != nil {
		if !os.IsNotExist(err) {
			return false, "", fmt.Errorf("error checking path %s for mount: %s", bindPathTarget, err)