title: changing permissions of files in a directory recursively
body: <p>I am trying to change the permissions of a files present in a directory and subdirectories using the below command and running into below error..can anyone help?</p>
  
  <pre><code>user@machine:/local/mnt/workspace$ find . -type f -exec chmod 644 {} \;
  chmod: changing permissions of `./halimpl/ncihal/adaptation/NonVolatileStore.cpp': Operation not permitted
  </code></pre>