Index: VirtualBox-6.1.18/src/VBox/Runtime/r0drv/linux/the-linux-kernel.h
===================================================================
--- VirtualBox-6.1.18.orig/src/VBox/Runtime/r0drv/linux/the-linux-kernel.h
+++ VirtualBox-6.1.18/src/VBox/Runtime/r0drv/linux/the-linux-kernel.h
@@ -137,9 +137,9 @@
 #include <linux/interrupt.h>
 #include <linux/completion.h>
 #include <linux/compiler.h>
-#if RTLNX_VER_MIN(5,9,0) /* linux/fs.h defined HAVE_UNLOCKED_IOCTL from 2.6.11 up to 5.9, when it became an implicit assumption. */
+//#if RTLNX_VER_MIN(5,9,0) /* linux/fs.h defined HAVE_UNLOCKED_IOCTL from 2.6.11 up to 5.9, when it became an implicit assumption. */
 # define HAVE_UNLOCKED_IOCTL 1 /* We use this in a couple of places, so for now just define it for 5.9+ too. */
-#endif
+//#endif
 #if !defined(HAVE_UNLOCKED_IOCTL) && RTLNX_VER_MAX(2,6,38)
 # include <linux/smp_lock.h>
 #endif