Get nid via filename

trying to use imagecache custom actions, and I would like to grab the nid.
http://drupal.org/node/363434

filefield_file_download($file) has the right stuff, but I can't mold it return the node id.

/**
 * Implementation of hook_file_download(). Yes, *that* hook that causes
 * any attempt for file upload module interoperability to fail spectacularly.
 */
function filefield_file_download($file) {
  $file = file_create_path($file);

  $result = db_query("SELECT * FROM {files} WHERE filepath = '%s'", $file);
  if (!$file = db_fetch_object($result)) {
    // We don't really care about this file.
    return;
  }

  // Find out if any filefield contains this file, and if so, which field
  // and node it belongs to. Required for later access checking.
  $cck_files = array();
  foreach (content_fields() as $field) {
    if ($field['type'] == 'filefield' || $field['type'] == 'image') {
      $db_info = content_database_info($field);
      $table = $db_info['table'];
      $fid_column = $db_info['columns']['fid']['column'];

      $columns = array('vid', 'nid');
      foreach ($db_info['columns'] as $property_name => $column_info) {
        $columns[] = $column_info['column'] .' AS '. $property_name;
      }
      $result = db_query("SELECT ". implode(', ', $columns) ."
                          FROM {". $table ."}
                          WHERE ". $fid_column ." = %d", $file->fid);

      while ($content = db_fetch_array($result)) {
        $content['field'] = $field;
        $cck_files[$field['field_name']][$content['vid']] = $content;
      }
    }
  }
  // If no filefield item is involved with this file, we don't care about it.
  if (empty($cck_files)) {
    return;
  }

  // If any node includes this file but the user may not view this field,
  // then deny the download.
  foreach ($cck_files as $field_name => $field_files) {
    if (!filefield_view_access($field_name)) {
      return -1;
    }
  }

  // So the overall field view permissions are not denied, but if access is
  // denied for a specific node containing the file, deny the download as well.
  // It's probably a little too restrictive, but I can't think of a
  // better way at the moment. Input appreciated.
  // (And yeah, node access checks also include checking for 'access content'.)
  $nodes = array();
  foreach ($cck_files as $field_name => $field_files) {
    foreach ($field_files as $revision_id => $content) {
      // Checking separately for each revision is probably not the best idea -
      // what if 'view revisions' is disabled? So, let's just check for the
      // current revision of that node.
      if (isset($nodes[$content['nid']])) {
        continue; // don't check the same node twice
      }
      $node = node_load($content['nid']);
      if (!node_access('view', $node)) {
        // You don't have permission to view the node this file is attached to.
        return -1;
      }
      $nodes[$content['nid']] = $node;
    }
  }

  // Well I guess you can see this file.
  $name = mime_header_encode($file->filename);
  $type = mime_header_encode($file->filemime);
  // Serve images and text inline for the browser to display rather than download.
  $disposition = ereg('^(text/|image/)', $file->filemime) ? 'inline' : 'attachment';
  return array(
    'Content-Type: '. $type .'; name='. $name,
    'Content-Length: '. $file->filesize,
    'Content-Disposition: '. $disposition .'; filename='. $name,
    'Cache-Control: private',
  );
}

This is what I got so far

//Get URI
//Split string into array, delimited by '/' 
//Pop the last value off of array
//Split string into array, delimited by '?'
//Grab the first value of the array
//U now have the last value without GET variables (filename)
$file = array_shift(explode('?',array_pop(explode('/',$_SERVER['REQUEST_URI']))));

$file = file_create_path($file);
$result = db_query("SELECT * FROM {files} WHERE filepath = '%s'", $file);

// Find out if any filefield contains this file, and if so, which field
// and node it belongs to. Required for later access checking.
$cck_files = array();
foreach (content_fields() as $field) {
  if ($field['type'] == 'image') {
    $db_info = content_database_info($field);
    $table = $db_info['table'];
    $fid_column = $db_info['columns']['fid']['column'];

    $columns = array('vid', 'nid');
    foreach ($db_info['columns'] as $property_name => $column_info) {
      $columns[] = $column_info['column'] .' AS '. $property_name;
    }
    $result = db_query("SELECT ". implode(', ', $columns) ."
                        FROM {". $table ."}
                        WHERE ". $fid_column ." = %d", $file->fid);

    while ($content = db_fetch_array($result)) {
      $content['field'] = $field;
      $cck_files[$field['field_name']][$content['vid']] = $content;
    }
  }
}
$nid_tmp = 'x';
$nodes = array();
foreach ($cck_files as $field_name => $field_files) {
  foreach ($field_files as $revision_id => $content) {
    $nid_tmp = $content['nid'];
  }
}

return $file ."\n". $nid_tmp;