void pdu_free(V9fsPDU *pdu)
{
    V9fsState *s = pdu->s;

    g_assert(!pdu->cancelled);
    QLIST_REMOVE(pdu, next);
    QLIST_INSERT_HEAD(&s->free_list, pdu, next);
}
void pdu_free(V9fsPDU *pdu)
{
    V9fsState *s = pdu->s;

    g_assert(!pdu->cancelled);
    QLIST_REMOVE(pdu, next);
    QLIST_INSERT_HEAD(&s->free_list, pdu, next);
}