title: fatal: error when closing sha1 file: Input/output error
body: <p>What do I do about this?</p>
  
  <pre><code>git push
  Counting objects: 30, done.
  Delta compression using up to 4 threads.
  Compressing objects: 100% (14/14), done.
  fatal: error when closing sha1 file: Input/output error
  error: pack-objects died of signal 13
  error: failed to push some refs to '...'
  </code></pre>
  
  <p>I tried the following from <a href="https://stackoverflow.com/questions/685319/git-pull-error-unable-to-create-temporary-sha1-filename">answers</a> to a similar question</p>
  
  <pre><code>git repack
  git prune
  git gc --aggressive
  </code></pre>
  
  <p>Nothing helps.  The remote is a mounted AFS filesystem, I have been pushing to it without incident for a couple years.  I am not anywhere near quota, and I have permission (I can touch a file on this filesystem without problem).  Git version 1.7.5.4.</p>