/fs/open.c

asmlinkage long sys_open(const char * filename, int flags, int mode)
{
	char * tmp;
	int fd, error;

#if BITS_PER_LONG != 32
	flags |= O_LARGEFILE;
#endif
	tmp = getname(filename);
	fd = PTR_ERR(tmp);
	if (!IS_ERR(tmp)) {
		fd = get_unused_fd();
		if (fd >= 0) {
			struct file *f = filp_open(tmp, flags, mode);
			error = PTR_ERR(f);
			if (IS_ERR(f))
				goto out_error;
			fd_install(fd, f);
		}
out:
		putname(tmp);
	}
	return fd;

out_error:
	put_unused_fd(fd);
	fd = error;
	goto out;
}