SUNRPC: New xdr_streams XDR encoder API

Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.

Also, all the client-side encoder functions return 0 now, making a
return value superfluous.  Take this opportunity to convert them to
return void instead.

This is a refactoring change.  It should not cause different behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index afe6784..651c9da 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -563,8 +563,17 @@
 	return cred->cr_ops->crvalidate(task, p);
 }
 
+static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
+				   __be32 *data, void *obj)
+{
+	struct xdr_stream xdr;
+
+	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
+	encode(rqstp, &xdr, obj);
+}
+
 int
-rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
+rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 		__be32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
@@ -574,7 +583,8 @@
 	if (cred->cr_ops->crwrap_req)
 		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 	/* By default, we encode the arguments normally. */
-	return encode(rqstp, data, obj);
+	rpcauth_wrap_req_encode(encode, rqstp, data, obj);
+	return 0;
 }
 
 int