[mnesia] Cleanly bring down mnesia

Aviods failing/wobbling testcase. Mnesia mishandled supervisors.

3 files changed, 23 insertions, 12 deletions

diff --git a/lib/mnesia/src/mnesia_event.erl b/lib/mnesia/src/mnesia_event.erl
index ec6b99ecaa..5a060a28ff 100644
--- a/lib/mnesia/src/mnesia_event.erl
+++ b/lib/mnesia/src/mnesia_event.erl
@@ -121,7 +121,7 @@ handle_system_event({mnesia_up, Node}, State) ->
     {ok, State#state{nodes = Nodes}}; 
 
 handle_system_event({mnesia_down, Node}, State) ->
-    case mnesia:system_info(fallback_activated) of
+    case mnesia:system_info(fallback_activated) andalso Node =/= node() of
 	true ->
 	    case mnesia_monitor:get_env(fallback_error_function) of
 		{mnesia, lkill} ->
@@ -129,8 +129,8 @@ handle_system_event({mnesia_down, Node}, State) ->
 			"must be restarted. Forcing shutdown "
 			"after mnesia_down from ~p...~n",
 		    report_fatal(Msg, [Node], nocore, State#state.dumped_core),
-		    mnesia:lkill(),
-		    exit(fatal);
+		    catch exit(whereis(mnesia_monitor), fatal),
+		    {ok, State};
 		{UserMod, UserFunc} ->
 		    Msg = "Warning: A fallback is installed and Mnesia got mnesia_down "
 			"from ~p. ~n",
diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl
index e110ad3241..8cb2e92c08 100644
--- a/lib/mnesia/src/mnesia_monitor.erl
+++ b/lib/mnesia/src/mnesia_monitor.erl
@@ -536,7 +536,11 @@ handle_info({'EXIT', Pid, R}, State) when Pid == State#state.supervisor ->
 
 handle_info({'EXIT', Pid, fatal}, State) when node(Pid) == node() ->
     dbg_out("~p got FATAL ERROR from: ~p~n",[?MODULE, Pid]),
-    exit(State#state.supervisor, shutdown),
+    %% This may hang supervisor if a shutdown happens at the same time as an fatal
+    %% is in progress
+    %% exit(State#state.supervisor, shutdown),
+    %% It is better to kill an innocent process
+    catch exit(whereis(mnesia_locker), kill),
     {noreply, State};
 
 handle_info(Msg = {'EXIT',Pid,_}, State) ->
diff --git a/lib/mnesia/test/mnesia_install_test.erl b/lib/mnesia/test/mnesia_install_test.erl
index 5d55fcac0e..3a2d44aa95 100644
--- a/lib/mnesia/test/mnesia_install_test.erl
+++ b/lib/mnesia/test/mnesia_install_test.erl
@@ -205,7 +205,7 @@ silly_upgrade(Config) when is_list(Config) ->
     ?match(ok, mnesia:install_fallback(Bup2)),
     file:delete(Bup2),
     %% Will generate intentional crash, fatal error
-    ?match([], mnesia_test_lib:stop_mnesia([Node2])),  
+    ?match([], mnesia_test_lib:stop_mnesia([Node2])),
     wait_till_dead([Node1, Node2]),
     ?match([], mnesia_test_lib:start_mnesia([Node1, Node2], [Tab1, Tab2])),
     ?match(match, verify_state(Tab1, Tab2, CpState)),
@@ -213,22 +213,29 @@ silly_upgrade(Config) when is_list(Config) ->
     ?match(ok, mnesia:install_fallback(Bup)),
     file:delete(Bup),
     %% Will generate intentional crash, fatal error
-    ?match([], mnesia_test_lib:stop_mnesia([Node1, Node2])),  
+    ?match([], mnesia_test_lib:stop_mnesia([Node1, Node2])),
     wait_till_dead([Node1, Node2]),
     ?match([], mnesia_test_lib:start_mnesia([Node1, Node2], [Tab1, Tab2])),
     CpState2 = [X || X <- CpState, element(1, X) /= Tab1],
     ?match(match, verify_state(Tab1, Tab2, CpState2)),
     ?verify_mnesia(Nodes, []).
 
-wait_till_dead([]) -> ok;
-wait_till_dead([N|Ns]) ->
+wait_till_dead([]) ->
+    ok; %% timer:sleep(5);
+wait_till_dead(Repeat = [N|Ns]) ->
     Apps = rpc:call(N, application, which_applications, []),
     case lists:keymember(mnesia, 1, Apps) of
-	true -> 
+	true ->
 	    timer:sleep(10),
-	    wait_till_dead([N|Ns]);
-	false -> 
-	    wait_till_dead(Ns)
+	    wait_till_dead(Repeat);
+	false ->
+	    case rpc:call(N, erlang, whereis, [mnesia_monitor]) of
+		undefined ->
+		    wait_till_dead(Ns);
+		_ ->
+		    timer:sleep(10),
+		    wait_till_dead(Repeat)
+	    end
     end.
 
 add_some_records(Tab1, Tab2, Old) ->