__cachefiles_prepare_write
extern int __cachefiles_prepare_write(struct cachefiles_object *object,
ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres),
ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres),
ret = __cachefiles_prepare_write(object, file, &pos, &aligned_len, len, true);