NFSv4.1: Add tracepoints for debugging slot table operations

Add tracepoints to nfs41_setup_sequence and nfs41_sequence_done
to track session and slot table state changes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c8b5ff6..a745f7c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -508,6 +508,7 @@
 		interrupted = true;
 	}
 
+	trace_nfs4_sequence_done(session, res);
 	/* Check the SEQUENCE operation status */
 	switch (res->sr_status) {
 	case 0:
@@ -660,6 +661,7 @@
 	 * set to 1 if an rpc level failure occurs.
 	 */
 	res->sr_status = 1;
+	trace_nfs4_setup_sequence(session, args);
 out_success:
 	rpc_call_start(task);
 	return 0;