int osl_munmap(void *start, size_t length);
int write_all(int fd, const char *buf, size_t *len);
int write_file(const char *filename, const void *buf, size_t size);
-int para_truncate(const char *filename, off_t size);
+int truncate_file(const char *filename, off_t size);
/**
* A wrapper for mkdir(2).