i'm not sure if this patch is of general use.  i needed it for
rangboom, where the agent posts the imported shared ns in /srv.
i have regression-tested it for some common cases.

Notes:
Sat Jul 14 18:45:53 EDT 2007 geoff
    I'm not sure either.  It does seem that not authenticating
    and being able to mount from /srv should be independent
    capabilities.


Reference: /n/sources/patch/applied/cfs-on-posted-fd
Date: Mon Jul  2 01:36:22 CES 2007
Signed-off-by: fst@9netics.com
Reviewed-by: geoff

--- /sys/src/cmd/cfs/cfs.c	Mon Jul  2 01:21:56 2007
+++ /sys/src/cmd/cfs/cfs.c	Mon Jul  2 01:21:52 2007
@@ -235,11 +235,17 @@
 mountinit(char *server, char *mountpoint)
 {
 	int p[2];
+	int err, noauth = 0;
 
 	/*
 	 *  grab a channel and call up the file server
 	 */
-	s.fd[0] = s.fd[1] = dial(netmkaddr(server, 0, "9fs"), 0, 0, 0);
+	if (strncmp(server, "/srv/", 5) == 0) {
+		s.fd[0] = s.fd[1] = open(server, ORDWR);
+		noauth = 1;
+	} else {
+		s.fd[0] = s.fd[1] = dial(netmkaddr(server, 0, "9fs"), 0, 0, 0);
+	}
 	if(s.fd[0] < 0)
 		error("opening data");
 
@@ -252,7 +258,11 @@
 	case 0:
 		break;
 	default:
-		if(amount(p[1], mountpoint, MREPL|MCREATE, "") < 0)
+		if (noauth)
+			err = mount(p[1], -1, mountpoint, MREPL|MCREATE, "");
+		else
+			err = amount(p[1], mountpoint, MREPL|MCREATE, "");
+		if (err < 0)
 			error("mount failed");
 		exits(0);
 	case -1: