Fix del_table_copy loading loop

When a local table copy was deleted but not yet loaded mnesia could
try to load it in a loop, which later when a table copy was added
again could result in a crash, since we don't have locks on the
receiver anymore. Tables can be simultaneously loaded and added.

Fixed by removing the table from the loader queue when it is
determined that the local copy is removed.

Also don't 'fatal' crash mnesia if table couldn't be loaded due
to table already existing.

Author: dgud

lib/mnesia/src/mnesia_controller.erl

@@ -1121,6 +1121,10 @@ handle_cast({adopt_orphans, Node, Tabs}, State) ->
     end,
     noreply(State2);
 
+handle_cast({del_table_copy, Tab}, #state{late_loader_queue = LLQ0, loader_queue = LQ0} = State0) ->
+    noreply(State0#state{late_loader_queue = gb_trees:delete_any(Tab, LLQ0),
+                         loader_queue = gb_trees:delete_any(Tab, LQ0)});
+
 handle_cast(Msg, State) ->
     error("~p got unexpected cast: ~tp~n", [?SERVER_NAME, Msg]),
     noreply(State).
@@ -1224,19 +1228,19 @@ handle_info(Done = #loader_done{worker_pid=WPid, table_name=Tab}, State0) ->
 		    false ->
 			ignore
 		end,
-		case ?catch_val({Tab, active_replicas}) of
-		    [_|_] -> % still available elsewhere
+
+                case {?catch_val({Tab, storage_type}), val({Tab, active_replicas})} of
+                    {unknown, _} -> %% Should not have a local copy anymore
+                        State1#state{late_loader_queue=gb_trees:delete_any(Tab, LateQueue0)};
+		    {_, [_|_]} -> % still available elsewhere
 			{value,{_,Worker}} = lists:keysearch(WPid,1,get_loaders(State0)),
 			add_loader(Tab,Worker,State1);
-		    _ ->
+                    {ram_copies, []} ->
 			DelState = State1#state{late_loader_queue=gb_trees:delete_any(Tab, LateQueue0)},
-			case ?catch_val({Tab, storage_type}) of
-			    ram_copies ->
-				cast({disc_load, Tab, ram_only}),
-				DelState;
-			    _ ->
-				DelState
-			end
+                        cast({disc_load, Tab, ram_only}),
+                        DelState;
+                    {_, []} ->  %% Table deleted or not loaded anywhere
+                        State1#state{late_loader_queue=gb_trees:delete_any(Tab, LateQueue0)}
 		end
 	end,
     State3 = opt_start_worker(State2),
@@ -1764,6 +1768,10 @@ del_active_replica(Tab, Node) ->
     set(Var, mark_blocked_tab(Blocked, New)),      % where_to_commit
     mnesia_lib:del({Tab, active_replicas}, Node),
     mnesia_lib:del({Tab, where_to_write}, Node),
+    case Node =:= node() of
+        true -> cast({del_table_copy, Tab});
+        false -> ok
+    end,
     update_where_to_wlock(Tab).
 
 change_table_access_mode(Cs) ->
@@ -2098,7 +2106,6 @@ opt_start_loader(State = #state{loader_queue = LoaderQ}) ->
 				true ->
 				    opt_start_loader(State#state{loader_queue = Rest});
 				false ->
-				    %% Start worker but keep him in the queue
 				    Pid = load_and_reply(self(), Worker),
 				    State#state{loader_pid=[{Pid,Worker}|get_loaders(State)],
 						loader_queue = Rest}

lib/mnesia/src/mnesia_event.erl

@@ -109,7 +109,7 @@ handle_any_event(Msg, State) ->
     {ok, State}.
 
 handle_table_event({Oper, Record, TransId}, State) ->
-    report_info("~p performed by ~p on record:~n\t~tp~n",
+    report_info("~p performed by ~p on record:~n\t~0tp~n",
 		[Oper, TransId, Record]),
     {ok, State}.  
 
@@ -160,9 +160,12 @@ handle_system_event({mnesia_overload, Details}, State) ->
     report_warning("Mnesia is overloaded: ~tw~n", [Details]),
     {ok, State}; 
 
-handle_system_event({mnesia_info, Format, Args}, State) ->
-    report_info(Format, Args),
-    {ok, State}; 
+handle_system_event({mnesia_info, Format, Args} = Event, State) ->
+    case put(last, Event) of
+        Event -> ok;
+        _ -> report_info(Format, Args)
+    end,
+    {ok, State};
 
 handle_system_event({mnesia_warning, Format, Args}, State) ->
     report_warning(Format, Args),

lib/mnesia/src/mnesia_loader.erl

@@ -47,7 +47,7 @@ val(Var) ->
 disc_load_table(Tab, Reason, Cs) ->
     Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
     Type = val({Tab, setorbag}),
-    dbg_out("Getting table ~tp (~p) from disc: ~tp~n",
+    dbg_out("Getting table ~0tp (~0p) from disc: ~0tp~n",
 	    [Tab, Storage, Reason]),
     ?eval_debug_fun({?MODULE, do_get_disc_copy},
 		    [{tab, Tab},
@@ -56,9 +56,9 @@ disc_load_table(Tab, Reason, Cs) ->
 		     {type, Type}]),
     do_get_disc_copy2(Tab, Reason, Storage, Type).
 
-do_get_disc_copy2(Tab, _Reason, Storage, _Type) when Storage == unknown ->
-    verbose("Local table copy of ~tp has recently been deleted, ignored.~n",
-	    [Tab]),
+do_get_disc_copy2(Tab, Reason, Storage, _Type) when Storage == unknown ->
+    verbose("Local table copy of ~0tp ~0p has recently been deleted, ignored.~n",
+	    [Tab, Reason]),
     {not_loaded, storage_unknown};
 do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_copies ->
     %% NOW we create the actual table
@@ -206,14 +206,14 @@ try_net_load_table(Tab, Reason, Ns, Cs) ->
               end,
     do_get_network_copy(Tab, Reason, Ns, Storage, Cs).
 
-do_get_network_copy(Tab, _Reason, _Ns, unknown, _Cs) ->
-    verbose("Local table copy of ~tp has recently been deleted, ignored.~n", [Tab]),
+do_get_network_copy(Tab, Reason, _Ns, unknown, _Cs) ->
+    verbose("Local table copy of ~0tp (~0p) has recently been deleted, ignored.~n", [Tab,Reason]),
     {not_loaded, storage_unknown};
 do_get_network_copy(Tab, Reason, Ns, Storage, Cs) ->
     [Node | Tail] = Ns,
     case lists:member(Node,val({current, db_nodes})) of
 	true ->
-	    dbg_out("Getting table ~tp (~p) from node ~p: ~tp~n",
+	    dbg_out("Getting table ~0tp (~0p) from node ~0p: ~0tp~n",
 		    [Tab, Storage, Node, Reason]),
 	    ?eval_debug_fun({?MODULE, do_get_network_copy},
 			    [{tab, Tab}, {reason, Reason},
@@ -289,6 +289,14 @@ init_receiver(Node, Tab,Storage,Cs,Reason) ->
 	    {atomic, {error,Result}} when
 		  element(1,Reason) == dumper ->
 		{error,Result};
+	    {atomic, {error,{mktab, _} = Reason}} ->
+                case val({Tab,where_to_read}) == node() of
+                    true ->  %% Already loaded
+                        ok;
+                    false ->
+                        fatal("Cannot create table ~tp: ~tp~n",
+                              [[Tab, Storage], Reason])
+                end;
 	    {atomic, {error,Result}} ->
 		fatal("Cannot create table ~tp: ~tp~n",
 		      [[Tab, Storage], Result]);
@@ -415,26 +423,28 @@ create_table(Tab, TabSize, Storage, Cs) ->
 		{ok, _} ->
 		    mnesia_lib:unlock_table(Tab),
 		    {Storage, Tab};
-		Else ->
+		{error, Reason} ->
 		    mnesia_lib:unlock_table(Tab),
-		    Else
+		    {error, {mktab, Reason}}
 	    end;
 	(Storage == ram_copies) or (Storage == disc_copies) ->
 	    EtsOpts = proplists:get_value(ets, StorageProps, []),
 	    Args = [{keypos, 2}, public, named_table, Cs#cstruct.type | EtsOpts],
 	    case mnesia_monitor:unsafe_mktab(Tab, Args) of
 		Tab ->
 		    {Storage, Tab};
-		Else ->
-		    Else
+		{error, Reason} ->
+		    {error, {mktab, Reason}}
 	    end;
         element(1, Storage) == ext ->
             {_, Alias, Mod} = Storage,
             case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
                 ok ->
                     {Storage, Tab};
-                Else ->
-                    Else
+                {error, Reason} ->
+                    {error, {mktab, Reason}};
+                Reason ->
+                    {error, {mktab, Reason}}
             end
     end.