code: def _bdev(dev=None):
      '''
      Resolve a bcacheX or cache to a real dev
      :return: basename of bcache dev
      '''
      if dev is None:
          dev = _fssys('cache0')
      else:
          dev = _bcpath(dev)
  
      if not dev:
          return False
      else:
          return _devbase(os.path.dirname(dev)f _bdev(dev=None):
      '''
      Resolve a bcacheX or cache to a real dev
      :return: basename of bcache dev
      '''
      if dev is None:
          dev = _fssys('cache0')
      else:
          dev = _bcpath(dev)
  
      if not dev:
          return False
      else:
          return _devbase(os.path.dirname(dev))
docs: Resolve a bcacheX or cache to a real dev
      :return: basename of bcache dev