From b43fe9eb4b3365156016ae3477747a46fc094bb8 Mon Sep 17 00:00:00 2001
From: Rick Macklem <rmacklem@FreeBSD.org>
Date: Thu, 1 Apr 2021 15:09:03 -0700
Subject: [PATCH] nfsd: silence rpcb_unset noise for NFSv4 only servers

An NFSv4 only configuration does not register with
rpcbind(). Without this patch a failure to rpcb_unset()
is reported when the daemon is terminated for this case.

This is harmless noise, but this patch avoids calling
rpcb_unset() for the NFSv4 only case, avoiding the noise.

When called with "-d", it still does the rpcb_unset(),
assuming that the configuration might have been
changed to NFSv4 only and unregistering with
rpcbind() might still be needed.

Reviewed by:	freqlabs
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D29449
---
 usr.sbin/nfsd/nfsd.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/usr.sbin/nfsd/nfsd.c b/usr.sbin/nfsd/nfsd.c
index 0eb9c2560cf1..0222d23f2312 100644
--- a/usr.sbin/nfsd/nfsd.c
+++ b/usr.sbin/nfsd/nfsd.c
@@ -101,6 +101,7 @@ static int stablefd = -1;	/* Fd for the stable restart file */
 static int backupfd;		/* Fd for the backup stable restart file */
 static const char *getopt_shortopts;
 static const char *getopt_usage;
+static int nfs_minvers = NFS_VER2;
 
 static int minthreads_set;
 static int maxthreads_set;
@@ -170,7 +171,6 @@ main(int argc, char **argv)
 	int bindhostc, bindanyflag, rpcbreg, rpcbregcnt;
 	int nfssvc_addsock;
 	int longindex = 0;
-	int nfs_minvers = NFS_VER2;
 	size_t nfs_minvers_size;
 	const char *lopt;
 	char **bindhost = NULL;
@@ -307,6 +307,16 @@ main(int argc, char **argv)
 			errx(1, "Out of memory");
 	}
 
+	if (unregister) {
+		/*
+		 * Unregister before setting nfs_minvers, in case the
+		 * value of vfs.nfsd.server_min_nfsvers has changed
+		 * since registering with rpcbind.
+		 */
+		unregistration();
+		exit (0);
+	}
+
 	nfs_minvers_size = sizeof(nfs_minvers);
 	error = sysctlbyname("vfs.nfsd.server_min_nfsvers", &nfs_minvers,
 	    &nfs_minvers_size, NULL, 0);
@@ -316,10 +326,6 @@ main(int argc, char **argv)
 		nfs_minvers = NFS_VER2;
 	}
 
-	if (unregister) {
-		unregistration();
-		exit (0);
-	}
 	if (reregister) {
 		if (udpflag) {
 			memset(&hints, 0, sizeof hints);
@@ -935,8 +941,8 @@ reapchild(__unused int signo)
 static void
 unregistration(void)
 {
-	if ((!rpcb_unset(NFS_PROGRAM, 2, NULL)) ||
-	    (!rpcb_unset(NFS_PROGRAM, 3, NULL)))
+	if ((nfs_minvers == NFS_VER2 && !rpcb_unset(NFS_PROGRAM, 2, NULL)) ||
+	    (nfs_minvers <= NFS_VER3 && !rpcb_unset(NFS_PROGRAM, 3, NULL)))
 		syslog(LOG_ERR, "rpcb_unset failed");
 }