--- zzzz-none-000/linux-4.4.271/fs/fcntl.c	2021-06-03 06:22:09.000000000 +0000
+++ hawkeye-5590-750/linux-4.4.271/fs/fcntl.c	2023-04-19 10:22:30.000000000 +0000
@@ -52,8 +52,10 @@
 		   arg |= O_NONBLOCK;
 
 	if (arg & O_DIRECT) {
+#ifdef CONFIG_DIRECT_IO
 		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
 			!filp->f_mapping->a_ops->direct_IO)
+#endif
 				return -EINVAL;
 	}
 
@@ -142,6 +144,7 @@
 	read_unlock(&filp->f_owner.lock);
 	return pid;
 }
+EXPORT_SYMBOL(sys_dup);
 
 static int f_setown_ex(struct file *filp, unsigned long arg)
 {