NFSv4.1: Add tracepoints for debugging layoutget/return/commit

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 214f9c4..c8b5ff6 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6860,6 +6860,10 @@
 	status = nfs4_wait_for_completion_rpc_task(task);
 	if (status == 0)
 		status = task->tk_status;
+	trace_nfs4_layoutget(lgp->args.ctx,
+			&lgp->args.range,
+			&lgp->res.range,
+			status);
 	/* if layoutp->len is 0, nfs4_layoutget_prepare called rpc_exit */
 	if (status == 0 && lgp->res.layoutp->len)
 		lseg = pnfs_layout_process(lgp);
@@ -6945,6 +6949,7 @@
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 	status = task->tk_status;
+	trace_nfs4_layoutreturn(lrp->args.inode, status);
 	dprintk("<-- %s status=%d\n", __func__, status);
 	rpc_put_task(task);
 	return status;
@@ -7131,6 +7136,7 @@
 	if (status != 0)
 		goto out;
 	status = task->tk_status;
+	trace_nfs4_layoutcommit(data->args.inode, status);
 out:
 	dprintk("%s: status %d\n", __func__, status);
 	rpc_put_task(task);