微信小程序服务端API 上传图片出现错误。

服务端代码：

const cloud = require('wx-server-sdk')

cloud.init()

const fs = require('fs')

exports.main = async (event, context) => {

const fileStream = fs.createReadStream(event.fileStream)

return await cloud.uploadFile({

cloudPath: event.cloudPath,

fileContent: fileStream,})}

用户端代码：

var cloudPath = "sss/yyy/m000.jpg"

var fileStream = 'cloud://暂时隐藏/my.jpg'  

wx.cloud.callFunction({

name: 'imgdoupload',

data: {

cloudPath: cloudPath,

fileStream: fileStream

},

success: res => {

console.log('success--res')

console.log(res)

}, fail: res => {

console.log(' fail--res')

console.log(res)

}

},2000)

运行时出现上传失败：

fail--res

Error: errCode: -404011 cloud function execution error | errMsg: cloud.callFunction:fail requestID 708c4dfe-243a-11e9-ab66-525400235f2a, cloud function service error code -504002, error message ENOENT: no such file or directory, open 'cloud://暂时隐藏/my.jpg'; at cloud.callFunction api; 

 at new e (WAService.js:1)

    at u (WAService.js:1)

    at Object.t.returnAsFinalCloudSDKError (WAService.js:1)

    at Function.success (WAService.js:1)

    at WAService.js:1

    at Qe (WAService.js:1)

    at Bt.<anonymous> (WAService.js:1)

    at Bt.emit (WAService.js:1)

    at ji (WAService.js:1)

    at WAService.js:1

实在不知问题出现在哪里，还请大神不吝赐教！！！！！！