NFSv4: Add a tracepoint to document open stateid updates

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -1481,6 +1481,7 @@ static void nfs_clear_open_stateid_locked(struct nfs4_state *state,
 	if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
 		nfs4_stateid_copy(&state->stateid, stateid);
 	nfs4_stateid_copy(&state->open_stateid, stateid);
+	trace_nfs4_open_stateid_update(state->inode, stateid, 0);
 out:
 	nfs_state_log_update_open_stateid(state);
 }
@@ -1524,6 +1525,7 @@ static void nfs_set_open_stateid_locked(struct nfs4_state *state,
 		write_sequnlock(&state->seqlock);
 		spin_unlock(&state->owner->so_lock);
 		rcu_read_unlock();
+		trace_nfs4_open_stateid_update_wait(state->inode, stateid, 0);
 		if (!signal_pending(current)) {
 			if (schedule_timeout(5*HZ) == 0)
 				status = -EAGAIN;
@@ -1545,6 +1547,7 @@ static void nfs_set_open_stateid_locked(struct nfs4_state *state,
 	if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
 		nfs4_stateid_copy(&state->stateid, stateid);
 	nfs4_stateid_copy(&state->open_stateid, stateid);
+	trace_nfs4_open_stateid_update(state->inode, stateid, status);
 	nfs_state_log_update_open_stateid(state);
 }
 

fs/nfs/nfs4trace.h

@@ -1061,6 +1061,8 @@ DECLARE_EVENT_CLASS(nfs4_inode_stateid_event,
 
 DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_setattr);
 DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_delegreturn);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_open_stateid_update);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_open_stateid_update_wait);
 
 DECLARE_EVENT_CLASS(nfs4_getattr_event,
 		TP_PROTO(