[PATCH] knfsd: SUNRPC: allow creating an RPC service without registering with portmapper

Sometimes we need to create an RPC service but not register it with the local
portmapper.  NFSv4 delegation callback, for example.

Change the svc_makesock() API to allow optionally creating temporary or
permanent sockets, optionally registering with the local portmapper, and make
it return the ephemeral port of the new socket.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/lockd/svc.c

@@ -223,23 +223,29 @@ static int find_socket(struct svc_serv *serv, int proto)
 	return found;
 }
 
-static int make_socks(struct svc_serv *serv, int proto)
-{
-	/* Make any sockets that are needed but not present.
+/*
+ * Make any sockets that are needed but not present.
  * If nlm_udpport or nlm_tcpport were set as module
  * options, make those sockets unconditionally
  */
+static int make_socks(struct svc_serv *serv, int proto)
+{
 	static int warned;
 	int err = 0;
+
 	if (proto == IPPROTO_UDP || nlm_udpport)
 		if (!find_socket(serv, IPPROTO_UDP))
-			err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport);
-	if (err == 0 && (proto == IPPROTO_TCP || nlm_tcpport))
+			err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport,
+						SVC_SOCK_DEFAULTS);
+	if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
 		if (!find_socket(serv, IPPROTO_TCP))
-			err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport);
-	if (!err)
+			err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport,
+						SVC_SOCK_DEFAULTS);
+
+	if (err >= 0) {
 		warned = 0;
-	else if (warned++ == 0)
+		err = 0;
+	} else if (warned++ == 0)
 		printk(KERN_WARNING
 		       "lockd_up: makesock failed, error=%d\n", err);
 	return err;

fs/nfs/callback.c

@@ -106,7 +106,6 @@ static void nfs_callback_svc(struct svc_rqst *rqstp)
 int nfs_callback_up(void)
 {
 	struct svc_serv *serv;
-	struct svc_sock *svsk;
 	int ret = 0;
 
 	lock_kernel();
@@ -119,17 +118,14 @@ int nfs_callback_up(void)
 	ret = -ENOMEM;
 	if (!serv)
 		goto out_err;
-	/* FIXME: We don't want to register this socket with the portmapper */
-	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
-	if (ret < 0)
+
+	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,
+							SVC_SOCK_ANONYMOUS);
+	if (ret <= 0)
 		goto out_destroy;
-	if (!list_empty(&serv->sv_permsocks)) {
-		svsk = list_entry(serv->sv_permsocks.next,
-				struct svc_sock, sk_list);
-		nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
-		dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
-	} else
-		BUG();
+	nfs_callback_tcpport = ret;
+	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
+
 	ret = svc_create_thread(nfs_callback_svc, serv);
 	if (ret < 0)
 		goto out_destroy;
@@ -140,6 +136,8 @@ out:
 	unlock_kernel();
 	return ret;
 out_destroy:
+	dprintk("Couldn't create callback socket or server thread; err = %d\n",
+		ret);
 	svc_destroy(serv);
 out_err:
 	nfs_callback_info.users--;

fs/nfsd/nfssvc.c

@@ -235,7 +235,8 @@ static int nfsd_init_socks(int port)
 
 	error = lockd_up(IPPROTO_UDP);
 	if (error >= 0) {
-		error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
+		error = svc_makesock(nfsd_serv, IPPROTO_UDP, port,
+					SVC_SOCK_DEFAULTS);
 		if (error < 0)
 			lockd_down();
 	}
@@ -245,7 +246,8 @@ static int nfsd_init_socks(int port)
 #ifdef CONFIG_NFSD_TCP
 	error = lockd_up(IPPROTO_TCP);
 	if (error >= 0) {
-		error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
+		error = svc_makesock(nfsd_serv, IPPROTO_TCP, port,
+					SVC_SOCK_DEFAULTS);
 		if (error < 0)
 			lockd_down();
 	}

include/linux/sunrpc/svcsock.h

@@ -62,7 +62,7 @@ struct svc_sock {
 /*
  * Function prototypes.
  */
-int		svc_makesock(struct svc_serv *, int, unsigned short);
+int		svc_makesock(struct svc_serv *, int, unsigned short, int flags);
 void		svc_close_socket(struct svc_sock *);
 int		svc_recv(struct svc_rqst *, long);
 int		svc_send(struct svc_rqst *);

net/sunrpc/svcsock.c

@@ -1689,9 +1689,11 @@ void svc_close_socket(struct svc_sock *svsk)
  * @serv: RPC server structure
  * @protocol: transport protocol to use
  * @port: port to use
+ * @flags: requested socket characteristics
  *
  */
-int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
+int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port,
+			int flags)
 {
 	struct sockaddr_in sin = {
 		.sin_family		= AF_INET,
@@ -1700,7 +1702,7 @@ int svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
 	};
 
 	dprintk("svc: creating socket proto = %d\n", protocol);
-	return svc_create_socket(serv, protocol, &sin, SVC_SOCK_DEFAULTS);
+	return svc_create_socket(serv, protocol, &sin, flags);
 }
 
 /*