[PATCH] knfsd: be more selective in which sockets lockd listens on

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP is set.

However as lockd performs services of the client as well, this is a problem.
If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the server will not be
able to call back to lockd.

So:
 - add an option to lockd_up saying which protocol is needed
 - Always open sockets for which an explicit port was given, otherwise
   only open a socket of the type required
 - Change nfsd to do one lockd_up per socket rather than one per thread.

This
 - removes the dependancy on CONFIG_NFSD_TCP
 - means that lockd may open sockets other than at startup
 - means that lockd will *not* listen on UDP if the only
   mounts are TCP mount (and nfsd hasn't started).

The latter is the only one that concerns me at all - I don't know if this
might be a problem with some servers.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index c52c999..0339b4d 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -134,6 +134,9 @@
 static void nfsd_last_thread(struct svc_serv *serv)
 {
 	/* When last nfsd thread exits we need to do some clean-up */
+	struct svc_sock *svsk;
+	list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
+		lockd_down();
 	nfsd_serv = NULL;
 	nfsd_racache_shutdown();
 	nfs4_state_shutdown();
@@ -218,11 +221,16 @@
 		error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
 		if (error < 0)
 			goto failure;
-
+		error = lockd_up(IPPROTO_UDP);
+		if (error < 0)
+			goto failure;
 #ifdef CONFIG_NFSD_TCP
 		error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
 		if (error < 0)
 			goto failure;
+		error = lockd_up(IPPROTO_TCP);
+		if (error < 0)
+			goto failure;
 #endif
 		do_gettimeofday(&nfssvc_boot);		/* record boot time */
 	} else
@@ -306,8 +314,6 @@
 
 	nfsdstats.th_cnt++;
 
-	lockd_up();				/* start lockd */
-
 	me.task = current;
 	list_add(&me.list, &nfsd_list);
 
@@ -364,13 +370,11 @@
 				break;
 		killsig = signo;
 	}
-	/* Clear signals before calling lockd_down() and svc_exit_thread() */
+	/* Clear signals before calling svc_exit_thread() */
 	flush_signals(current);
 
 	lock_kernel();
 
-	/* Release lockd */
-	lockd_down();
 	list_del(&me.list);
 	nfsdstats.th_cnt --;