title: How do i mount sub folder contents to parent folder?
body: <p>I have folder structure as below:</p>
  
  <pre>
  /files
  /files/upload
  </pre>
  
  <p>I need to mount /files/upload to /files.</p>
  
  <p>When user uploads files to <pre>/files/upload</pre> it should auto copy(sync/mount) uploaded file to base folder: <pre>/files</pre>.</p>
  
  <p>Is it achievable using linux mount command ?</p>
  
  <p>Thanks.</p>