code: def remount_with_additional_flags(mountpoint, existing_options, mountflags):
      
      mountflags |= libc.MS_REMOUNT|libc.MS_BIND
      for option, flag in libc.MOUNT_FLAGS.items():
          if option in existing_options:
              mountflags |= flag
  
      libc.mount(None, mountpoint, None, mountflags, None)
docs: Remount an existing mount point with additional flags.
      @param mountpoint: the mount point as bytes
      @param existing_options: dict with current mount existing_options as bytes
      @param mountflags: int with additional mount existing_options (cf. libc.MS_* constants)