NFSD: Update the NFSv3 READ3res encode to use struct xdr_stream

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 352691c..859cc6c 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -1005,30 +1005,33 @@ nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
 int
 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_res_stream;
 	struct nfsd3_readres *resp = rqstp->rq_resp;
 	struct kvec *head = rqstp->rq_res.head;
 
-	*p++ = resp->status;
-	p = encode_post_op_attr(rqstp, p, &resp->fh);
-	if (resp->status == 0) {
-		*p++ = htonl(resp->count);
-		*p++ = htonl(resp->eof);
-		*p++ = htonl(resp->count);	/* xdr opaque count */
-		xdr_ressize_check(rqstp, p);
-		/* now update rqstp->rq_res to reflect data as well */
-		rqstp->rq_res.page_len = resp->count;
-		if (resp->count & 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->count & 3);
-		}
-		if (svc_encode_result_payload(rqstp, head->iov_len,
-					      resp->count))
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return 0;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
 			return 0;
-		return 1;
-	} else
-		return xdr_ressize_check(rqstp, p);
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return 0;
+		if (xdr_stream_encode_bool(xdr, resp->eof) < 0)
+			return 0;
+		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
+			return 0;
+		xdr_write_pages(xdr, resp->pages, rqstp->rq_res.page_base,
+				resp->count);
+		if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
+			return 0;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
+			return 0;
+	}
+
+	return 1;
 }
 
 /* WRITE */