NFSD: Update the NFSv2 CREATE argument decoder to use struct xdr_stream

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfsxdr.c

@@ -401,14 +401,12 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
 int
 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_createargs *args = rqstp->rq_argp;
 
-	if (   !(p = decode_fh(p, &args->fh))
-	    || !(p = decode_filename(p, &args->name, &args->len)))
-		return 0;
-	p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_diropargs(xdr, &args->fh,
+				       &args->name, &args->len) &&
+		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
 }
 
 int