https://git.linux-nfs.org/?p=steved/nfs-utils.git;a=commitdiff;h=feb3dfc7127cf1337530ccb06ed90e818b026a07#patch1
https://bugzilla.redhat.com/show_bug.cgi?id=1979816
https://bugs.gentoo.org/808183

Slightly rebased by sam@ to account for version.h moving around.

From feb3dfc7127cf1337530ccb06ed90e818b026a07 Mon Sep 17 00:00:00 2001
From: Steve Dickson <steved@redhat.com>
Date: Wed, 22 Sep 2021 11:31:56 -0400
Subject: [PATCH] mountd: only do NFSv4 logging on supported kernels.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1979816
Signed-off-by: Steve Dickson <steved@redhat.com>
--- a/support/export/v4clients.c
+++ b/support/export/v4clients.c
@@ -10,6 +10,7 @@
 #include <sys/inotify.h>
 #include <errno.h>
 #include "export.h"
+#include "../../utils/mount/version.h"
 
 /* search.h declares 'struct entry' and nfs_prot.h
  * does too.  Easiest fix is to trick search.h into
@@ -23,6 +24,8 @@ static int clients_fd = -1;
 
 void v4clients_init(void)
 {
+	if (linux_version_code() < MAKE_VERSION(5, 3, 0))
+		return;
 	if (clients_fd >= 0)
 		return;
 	clients_fd = inotify_init1(IN_NONBLOCK);