docs: def devices_data():
      """Returns devices data.
      """
      response = {}
      for part in psutil.disk_partitions():
          device = part.device
          response[device] = {
              'device': device,
              'mountpoint': part.mountpoint,
              'fstype': part.fstype,
              'opts': part.opts,
          }
          if part.mountpoint:
              usage = psutil.disk_usage(part.mountpoint)
              response[device]['usage'] = {
                  'size': mark(usage.total, 'bytes'),
                  'used': mark(usage.used, 'bytes'),
                  'free': mark(usage.free, 'bytes'),
                  'percent': mark(usage.percent, 'percentage')
              }
      return response