static void hash_id(struct fuse *f, struct node *node)
{
    size_t hash = node->nodeid % f->id_table_size;
    node->id_next = f->id_table[hash];
    f->id_table[hash] = node;
}
static void hash_id(struct fuse *f, struct node *node)
{
    size_t hash = node->nodeid % f->id_table_size;
    node->id_next = f->id_table[hash];
    f->id_table[hash] = node;
}