smb3: add tracepoint for session expired or deleted

In debugging reconnection problems, want to be able to more easily
trace cases in which the server has marked the SMB3 session
expired or deleted (to distinguish from timeout cases).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

fs/cifs/smb2ops.c

@@ -1483,7 +1483,11 @@ smb2_is_session_expired(char *buf)
 	    shdr->Status != STATUS_USER_SESSION_DELETED)
 		return false;
 
+	trace_smb3_ses_expired(shdr->TreeId, shdr->SessionId,
+			       le16_to_cpu(shdr->Command),
+			       le64_to_cpu(shdr->MessageId));
 	cifs_dbg(FYI, "Session expired or deleted\n");
+
 	return true;
 }
 

fs/cifs/trace.h

@@ -281,6 +281,7 @@ DEFINE_EVENT(smb3_cmd_done_class, smb3_##name,    \
 	TP_ARGS(tid, sesid, cmd, mid))
 
 DEFINE_SMB3_CMD_DONE_EVENT(cmd_done);
+DEFINE_SMB3_CMD_DONE_EVENT(ses_expired);
 
 DECLARE_EVENT_CLASS(smb3_exit_err_class,
 	TP_PROTO(unsigned int xid,