Previously this would sit there with stale data in the browser
if you were viewing a filesystem and then deleted it in the
background.
Signed-off-by: John Spray <john.spray@redhat.com>
                 $.get("{{ url_prefix }}/filesystem_data/" + content_data.fs_status.filesystem.id  + "/", function(data) {
                     _.extend(content_data.fs_status, data);
                     setTimeout(refresh, 5000);
+                }).fail(function() {
+                    // Perhaps the filesystem we're viewing no longer exists.
+                    // Go back to home.
+                    window.location.href = "{{ url_prefix }}/";
                 });
             };