NFSD: Update the NFSv2 READLINK result encoder to use struct xdr_stream

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index 989144b..74d9d11 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -527,24 +527,22 @@ nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
 int
 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_res_stream;
 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
 	struct kvec *head = rqstp->rq_res.head;
 
-	*p++ = resp->status;
-	if (resp->status != nfs_ok)
-		return xdr_ressize_check(rqstp, p);
-
-	*p++ = htonl(resp->len);
-	xdr_ressize_check(rqstp, p);
-	rqstp->rq_res.page_len = resp->len;
-	if (resp->len & 3) {
-		/* need to pad the tail */
-		rqstp->rq_res.tail[0].iov_base = p;
-		*p = 0;
-		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
-	}
-	if (svc_encode_result_payload(rqstp, head->iov_len, resp->len))
+	if (!svcxdr_encode_stat(xdr, resp->status))
 		return 0;
+	switch (resp->status) {
+	case nfs_ok:
+		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
+			return 0;
+		xdr_write_pages(xdr, &resp->page, 0, resp->len);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
+			return 0;
+		break;
+	}
+
 	return 1;
 }