def has_disk_dev(mapping, disk_dev):
 for disk in mapping:
  info = mapping[disk]
  if (info['dev'] == disk_dev):
   return True
 return False

def has_disk_dev ( mapping , disk_dev ) : for disk in mapping : info = mapping [ disk ] if ( info [ 'dev' ] == disk_dev ) : return True return False
determine if a disk device name has already been used .