code: def change_disk_usage(self, usage_change, file_path, st_dev):
          
          mount_point = self._mount_point_for_device(st_dev)
          if mount_point:
              total_size = mount_point['total_size']
              if total_size is not None:
                  if total_size - mount_point['used_size'] < usage_change:
                      self.raise_io_error(errno.ENOSPC, file_path)
              mount_point['used_size'] += usage_change
docs: Change the used disk space by the given amount.
  
          Args:
              usage_change: Number of bytes added to the used space.
                  If negative, the used space will be decreased.
  
              file_path: The path of the object needing the disk space.
  
              st_dev: The device ID for the respective file system.
  
          Raises:
              IOError: if usage_change exceeds the free file system space