The write_sync_close function from gnome-keyring/pkcs11/gkm/gkm-transaction.c,
works incorrectly in presence of partial writes. The main write loop looks as
follows:

  while (n_data > 0) {
    res = write (fd, data, n_data);
    if (res < 0) {
      ...
    }
    n_data -= MAX (res, n_data);
  }

Thus after a single iteration n_data will be always zero, even if not
everything have been written so far.