NFSv4: Add tracepoints for debugging rename

Add tracepoints to debug renames.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index daf0854..4b3ba92 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3329,7 +3329,8 @@
 static int nfs4_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
 				 struct inode *new_dir)
 {
-	struct nfs_renameres *res = task->tk_msg.rpc_resp;
+	struct nfs_renamedata *data = task->tk_calldata;
+	struct nfs_renameres *res = &data->res;
 
 	if (!nfs4_sequence_done(task, &res->seq_res))
 		return 0;
@@ -3375,9 +3376,10 @@
 	struct nfs4_exception exception = { };
 	int err;
 	do {
-		err = nfs4_handle_exception(NFS_SERVER(old_dir),
-				_nfs4_proc_rename(old_dir, old_name,
-					new_dir, new_name),
+		err = _nfs4_proc_rename(old_dir, old_name,
+					new_dir, new_name);
+		trace_nfs4_rename(old_dir, old_name, new_dir, new_name, err);
+		err = nfs4_handle_exception(NFS_SERVER(old_dir), err,
 				&exception);
 	} while (exception.retry);
 	return err;