[PATCH] RPC: Allow the sunrpc server to multiplex serveral programs on a single port

 The NFS and NFSACL programs run on the same RPC transport.  This patch adds
 support for this by converting svc_program into a chained list of programs
 (server-side).

 Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
 Signed-off-by: Olaf Kirch <okir@suse.de>
 Signed-off-by: Andrew Morton <akpm@osdl.org>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Author: Andreas Gruenbacher

include/linux/sunrpc/svc.h

@@ -240,9 +240,10 @@ struct svc_deferred_req {
 };
 
 /*
- * RPC program
+ * List of RPC programs on the same transport endpoint
  */
 struct svc_program {
+	struct svc_program *	pg_next;	/* other programs (same xprt) */
 	u32			pg_prog;	/* program number */
 	unsigned int		pg_lovers;	/* lowest version */
 	unsigned int		pg_hivers;	/* lowest version */

net/sunrpc/svc.c

@@ -35,29 +35,31 @@ svc_create(struct svc_program *prog, unsigned int bufsize)
 	if (!(serv = (struct svc_serv *) kmalloc(sizeof(*serv), GFP_KERNEL)))
 		return NULL;
 	memset(serv, 0, sizeof(*serv));
+	serv->sv_name      = prog->pg_name;
 	serv->sv_program   = prog;
 	serv->sv_nrthreads = 1;
 	serv->sv_stats     = prog->pg_stats;
 	serv->sv_bufsz	   = bufsize? bufsize : 4096;
-	prog->pg_lovers = prog->pg_nvers-1;
 	xdrsize = 0;
-	for (vers=0; vers<prog->pg_nvers ; vers++)
-		if (prog->pg_vers[vers]) {
-			prog->pg_hivers = vers;
-			if (prog->pg_lovers > vers)
-				prog->pg_lovers = vers;
-			if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
-				xdrsize = prog->pg_vers[vers]->vs_xdrsize;
-		}
+	while (prog) {
+		prog->pg_lovers = prog->pg_nvers-1;
+		for (vers=0; vers<prog->pg_nvers ; vers++)
+			if (prog->pg_vers[vers]) {
+				prog->pg_hivers = vers;
+				if (prog->pg_lovers > vers)
+					prog->pg_lovers = vers;
+				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
+					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
+			}
+		prog = prog->pg_next;
+	}
 	serv->sv_xdrsize   = xdrsize;
 	INIT_LIST_HEAD(&serv->sv_threads);
 	INIT_LIST_HEAD(&serv->sv_sockets);
 	INIT_LIST_HEAD(&serv->sv_tempsocks);
 	INIT_LIST_HEAD(&serv->sv_permsocks);
 	spin_lock_init(&serv->sv_lock);
 
-	serv->sv_name      = prog->pg_name;
-
 	/* Remove any stale portmap registrations */
 	svc_register(serv, 0, 0);
 
@@ -339,7 +341,10 @@ svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
 		goto sendit;
 	}
 
-	if (prog != progp->pg_prog)
+	for (progp = serv->sv_program; progp; progp = progp->pg_next)
+		if (prog == progp->pg_prog)
+			break;
+	if (progp == NULL)
 		goto err_bad_prog;
 
 	if (vers >= progp->pg_nvers ||
@@ -452,11 +457,7 @@ svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
 	goto sendit;
 
 err_bad_prog:
-#ifdef RPC_PARANOIA
-	if (prog != 100227 || progp->pg_prog != 100003)
-		printk("svc: unknown program %d (me %d)\n", prog, progp->pg_prog);
-	/* else it is just a Solaris client seeing if ACLs are supported */
-#endif
+	dprintk("svc: unknown program %d\n", prog);
 	serv->sv_stats->rpcbadfmt++;
 	svc_putu32(resv, rpc_prog_unavail);
 	goto sendit;