File 0202-nfsd-allow-server-scope-to-be-set-with-con... of Package nfs-utils.27825

Overview Repositories Revisions Requests Users Attributes Meta

File 0202-nfsd-allow-server-scope-to-be-set-with-config-or-com.patch of Package nfs-utils.27825

From 580ac005d11ddb9a9622e380ba8e947ad743a38f Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Mon, 21 Nov 2022 14:24:00 -0500
Subject: [PATCH] nfsd: allow server scope to be set with config or command
 line.

NFSv4.1 and later require the server to report a "scope".  Servers with
the same scope are expected to understand each other's state ids etc,
though may not accept them - this ensure there can be no
misunderstanding.  This is helpful for migration.

Servers with different scope are known to be different and if a server
appears to change scope on a restart, lock recovery must not be
attempted.

It is important for fail-over configurations to have the same scope for
all server instances.  Linux NFSD sets scope to host name.  It is common
for fail-over configurations to use different host names on different
server nodes.  So the default is not good for these configurations and
must be over-ridden.

As discussed in
  https://github.com/ClusterLabs/resource-agents/issues/1644
some HA management tools attempt to address this with calls to "unshare"
and "hostname" before running "rpc.nfsd".  This is unnecessarily
cumbersome.

This patch adds a "-S" command-line option and nfsd.scope config value
so that the scope can be set easily for nfsd.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>
---
 utils/nfsd/nfsd.c   |   16 +++++++++++++++-
 utils/nfsd/nfsd.man |   10 +++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

--- a/utils/nfsd/nfsd.c
+++ b/utils/nfsd/nfsd.c
@@ -22,6 +22,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <sched.h>
 
 #include "nfslib.h"
 #include "nfssvc.h"
@@ -36,6 +37,7 @@ static void	usage(const char *);
 static struct option longopts[] =
 {
 	{ "host", 1, 0, 'H' },
+	{ "scope", 1, 0, 'S'},
 	{ "help", 0, 0, 'h' },
 	{ "no-nfs-version", 1, 0, 'N' },
 	{ "nfs-version", 1, 0, 'V' },
@@ -101,6 +103,7 @@ main(int argc, char **argv)
 	int	count = NFSD_NPROC, c, i, error = 0, portnum = 0, fd, found_one;
 	char *p, *progname, *port, *rdma_port = NULL;
 	char **haddr = NULL;
+	char *scope = NULL;
 	unsigned int hcounter = 0;
 	int	socket_up = 0;
 	unsigned int minorvers = 0;
@@ -134,7 +137,7 @@ main(int argc, char **argv)
 	xlog_syslog(0);
 	xlog_stderr(1);
 
-	while ((c = getopt_long(argc, argv, "dH:hN:V:p:P:sTUrG:L:", longopts, NULL)) != EOF) {
+	while ((c = getopt_long(argc, argv, "dH:S:hN:V:p:P:sTUrG:L:", longopts, NULL)) != EOF) {
 		switch(c) {
 		case 'd':
 			xlog_config(D_ALL, 1);
@@ -156,6 +159,9 @@ main(int argc, char **argv)
 			}
 			hcounter++;
 			break;
+		case 'S':
+			scope = optarg;
+			break;
 		case 'P':	/* XXX for nfs-server compatibility */
 		case 'p':
 			/* only the last -p option has any effect */
@@ -334,6 +340,14 @@ main(int argc, char **argv)
 	if (lease  > 0)
 		nfssvc_set_time("lease", lease);
 
+	if (scope) {
+		if (unshare(CLONE_NEWUTS) < 0 ||
+		    sethostname(scope, strlen(scope)) < 0) {
+			xlog(L_ERROR, "Unable to set server scope: %m");
+			error = -1;
+			goto out;
+		}
+	}
 	i = 0;
 	do {
 		error = nfssvc_set_sockets(AF_INET, proto4, haddr[i], port);
--- a/utils/nfsd/nfsd.man
+++ b/utils/nfsd/nfsd.man
@@ -35,9 +35,17 @@ Note that
 .B lockd
 (which performs file locking services for NFS) may still accept
 request on all known network addresses.  This may change in future
-releases of the Linux Kernel. This option can be used multiple time 
+releases of the Linux Kernel. This option can be used multiple times
 to listen to more than one interface.
 .TP
+.B \S " or " \-\-scope scope
+NFSv4.1 and later require the server to report a "scope" which is used
+by the clients to detect if two connections are to the same server.
+By default Linux NFSD uses the host name as the scope.
+.sp
+It is particularly important for high-availablity configurations to ensure
+that all potential server nodes report the same server scope.
+.TP
 .B \-p " or " \-\-port  port
 specify a different port to listen on for NFS requests. By default,
 .B rpc.nfsd

Places

File 0202-nfsd-allow-server-scope-to-be-set-with-config-or-com.patch of Package nfs-utils.27825

Places