title: `chattr +Cm foo`(SUCCESS) vs `chattr +C foo; chattr +m foo`(FAILURE)
body: <p>On my btrfs system, <strong><code>chattr +Cm</code></strong> worked. (It means <code>no copy on write</code> and <code>don't compress</code>).</p>
  <p>However, when the flags separated into <strong><code>chattr +C</code> and <code>chattr +m</code></strong>, the latter fails.<br />
  Only the latter prints error even if these also run in reverse order or use <code>btrfs prop set foo compression no</code> instead of <code>chattr +m</code>.</p>
  <p>Why does <code>chattr +Cm</code>(or <code>chattr +mC</code>) succeed although the other ways fail?</p>
  <p>Extract from my <code>/etc/fstab</code> for reference:</p>
  <pre><code>UUID=...  /home  btrfs  rw,noatime,compress=lzo,ssd,space_cache,commit=120,subvol=@home  0 0
  </code></pre>