smb3: add trace point for oplock not found

In order to debug problems with server potentially
sending us an oplock that we don't recognize (or a race
with close and oplock break) it would be helpful to have
a dynamic trace point for this case.  New tracepoint
is called trace_smb3_oplock_not_found
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2misc.c

@@ -732,6 +732,10 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	}
 	spin_unlock(&cifs_tcp_ses_lock);
 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
+	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
+				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
+				  le64_to_cpu(rsp->hdr.SessionId));
+
 	return true;
 }
 

fs/cifs/trace.h

@@ -158,6 +158,7 @@ DEFINE_SMB3_FD_EVENT(flush_enter);
 DEFINE_SMB3_FD_EVENT(flush_done);
 DEFINE_SMB3_FD_EVENT(close_enter);
 DEFINE_SMB3_FD_EVENT(close_done);
+DEFINE_SMB3_FD_EVENT(oplock_not_found);
 
 DECLARE_EVENT_CLASS(smb3_fd_err_class,
 	TP_PROTO(unsigned int xid,