int for_each_subdir(int (*func)(const char *, void *), void *private_data);
__must_check int mark_fd_nonblocking(int fd);
static inline int dss_rename(const char *old_path, const char *new_path)
int for_each_subdir(int (*func)(const char *, void *), void *private_data);
__must_check int mark_fd_nonblocking(int fd);
static inline int dss_rename(const char *old_path, const char *new_path)