title: s3fs unmount: directory is not empty
body: <p>I'm using <a href="https://github.com/s3fs-fuse/s3fs-fuse/wiki/Fuse-Over-Amazon" rel="noreferrer"><code>s3fs</code></a> and <a href="https://osxfuse.github.io/" rel="noreferrer"><code>osxfuse</code></a> to mount an S3 directory on my Mac:</p>
  
  <pre><code>s3fs my-bucket-name $PWD/s3
  </code></pre>
  
  <p>When it's time to unmount it, I do this:</p>
  
  <pre><code>% s3fs umount $PWD/s3
  s3fs: MOUNTPOINT directory /Users/kwilliams/blah/s3 is not empty.
  if you are sure this is safe, can use the 'nonempty' mount option.
  </code></pre>
  
  <p>I am <strong>not</strong> sure this is safe - I didn't knowingly create any new files in the <code>s3</code> directory, and if any new ones were created, I need to know about it so I can clean them up or figure out what happened.</p>
  
  <p>I also don't want it to perform any actions (creation, deletion) on the underlying S3 bucket when trying to unmount.  I'm not sure what the <code>nonempty</code> option will do.</p>
  
  <p>The directory certainly appears nonempty when I do <code>ls</code>, because it shows me the contents of the bucket.</p>
  
  <p>Finally - the message says I can <code>use the 'nonempty' mount option</code> - is it saying I should have used that option at mount time, or I can use it when unmounting?  <code>s3fs --help</code> doesn't indicate that <code>s3fs umount</code> can take any options.</p>