Javascript专家，请帮助我解决此文件系统模块（fs）相关问题

Question

我收到此错误消息：错误：EXDEV：不允许跨设备链接，重命名为'/ tmp / upload_28ccb32e4096c7647d7318d3d3dd416f'->'./public/uploadDir/2970cda49b59328521550a4240f36b4e.jpg'     错误（本机）。

代码：

router.post('/', eformidable(), (req, res) => {
  const hash = c.createHash('md5');
  MongoClient.connect(url, { useNewUrlParser: true }, (err, db) => {
    if (err) throw err;
    const dbo = db.db('Database');
    // Find all documents in the customers collection:
    dbo.collection('HouseAds').find({ _id: req.body.LID }, (err2, result) => {
      if (err2) throw err2;
      /* if the ID is valid and was found in the database. */
      if (result != null) {
        // console.log(req.files);
        const fileHandler = req.files.kep;
        const nameOfImage = `${hash.update(fileHandler.toJSON.toString() + Date().toString()).digest('hex')}.jpg`;
        const pathOfImage = `./public/uploadDir/${nameOfImage}`;
        fs.rename(fileHandler.path, pathOfImage, (error) => {
          if (error) {
            res.status(500).send('hooooooooops.');
            throw error;
          }