rem: node->stat_valid = time(NULL) + CACHE_TIMEOUT;
add: node->stat_valid = time(NULL) + cache_stat_timeout;
context: static void cache_add_attr(const char *path, const struct stat *stbuf){    struct node *node;    time_t now;    pthread_mutex_lock(&cache_lock);    node = cache_get(path);    now = time(NULL);    node->stat = *stbuf;    node->stat_valid = time(NULL) + CACHE_TIMEOUT;    if (node->stat_valid > node->valid)        node->valid = node->stat_valid;    cache_clean();    pthread_mutex_unlock(&cache_lock);}