Merge branch 'dgud/mnesia/checkpoint-crash/OTP-14167' into maint-19

* dgud/mnesia/checkpoint-crash/OTP-14167:
  Fixed crash when a table was deleted during checkpoint traversal

3 files changed, 38 insertions, 15 deletions

diff --git a/lib/mnesia/src/mnesia_checkpoint.erl b/lib/mnesia/src/mnesia_checkpoint.erl
index 9eb939e8d3..fc626940b4 100644
--- a/lib/mnesia/src/mnesia_checkpoint.erl
+++ b/lib/mnesia/src/mnesia_checkpoint.erl
@@ -909,7 +909,7 @@ retainer_loop(Cp = #checkpoint_args{name=Name}) ->
 	    retainer_loop(Cp2);
 
 	{From, {iter_end, Iter}}  ->
-	    retainer_fixtable(Iter#iter.oid_tab, false),
+	    ?SAFE(retainer_fixtable(Iter#iter.oid_tab, false)),
 	    Iters = Cp#checkpoint_args.iterators -- [Iter],
 	    reply(From, Name, ok),
 	    retainer_loop(Cp#checkpoint_args{iterators = Iters});
@@ -971,7 +971,8 @@ do_stop(Cp) ->
     unset({checkpoint, Name}),
     lists:foreach(fun deactivate_tab/1, Cp#checkpoint_args.retainers),
     Iters = Cp#checkpoint_args.iterators,
-    lists:foreach(fun(I) -> retainer_fixtable(I#iter.oid_tab, false) end, Iters).
+    [?SAFE(retainer_fixtable(Tab, false)) || #iter{main_tab=Tab} <- Iters],
+    ok.
 
 deactivate_tab(R) ->
     Name = R#retainer.cp_name,
@@ -1151,7 +1152,7 @@ do_change_copy(Cp, Tab, FromType, ToType) ->
     Cp#checkpoint_args{retainers = Rs, nodes = writers(Rs)}.
 
 check_iter(From, Iter) when Iter#iter.pid == From ->
-    retainer_fixtable(Iter#iter.oid_tab, false),
+    ?SAFE(retainer_fixtable(Iter#iter.oid_tab, false)),
     false;
 check_iter(_From, _Iter) ->
     true.
diff --git a/lib/mnesia/src/mnesia_event.erl b/lib/mnesia/src/mnesia_event.erl
index 7320d381ea..6f7531245f 100644
--- a/lib/mnesia/src/mnesia_event.erl
+++ b/lib/mnesia/src/mnesia_event.erl
@@ -114,7 +114,8 @@ handle_table_event({Oper, Record, TransId}, State) ->
 handle_system_event({mnesia_checkpoint_activated, _Checkpoint}, State) ->
     {ok, State};
 
-handle_system_event({mnesia_checkpoint_deactivated, _Checkpoint}, State) ->
+handle_system_event({mnesia_checkpoint_deactivated, Checkpoint}, State) ->
+    report_error("Checkpoint '~p' has been deactivated, last table copy deleted.\n",[Checkpoint]),
     {ok, State};
 
 handle_system_event({mnesia_up, Node}, State) ->
diff --git a/lib/mnesia/test/mnesia_evil_backup.erl b/lib/mnesia/test/mnesia_evil_backup.erl
index e745ec9b04..044cf501fd 100644
--- a/lib/mnesia/test/mnesia_evil_backup.erl
+++ b/lib/mnesia/test/mnesia_evil_backup.erl
@@ -723,18 +723,18 @@ bup_records(File, Mod) ->
 	    exit(Reason)
     end.
 
-sops_with_checkpoint(doc) -> 
+sops_with_checkpoint(doc) ->
     ["Test schema operations during a checkpoint"];
 sops_with_checkpoint(suite) -> [];
 sops_with_checkpoint(Config) when is_list(Config) ->
-    Ns = ?acquire_nodes(2, Config),
-    
+    Ns = [N1,N2] = ?acquire_nodes(2, Config),
+
     ?match({ok, cp1, Ns}, mnesia:activate_checkpoint([{name, cp1},{max,mnesia:system_info(tables)}])),
-    Tab = tab, 
+    Tab = tab,
     ?match({atomic, ok}, mnesia:create_table(Tab, [{disc_copies,Ns}])),
     OldRecs = [{Tab, K, -K} || K <- lists:seq(1, 5)],
     [mnesia:dirty_write(R) || R <- OldRecs],
-    
+
     ?match({ok, cp2, Ns}, mnesia:activate_checkpoint([{name, cp2},{max,mnesia:system_info(tables)}])),
     File1 = "cp1_delete_me.BUP",
     ?match(ok, mnesia:dirty_write({Tab,6,-6})),
@@ -742,16 +742,16 @@ sops_with_checkpoint(Config) when is_list(Config) ->
     ?match(ok, mnesia:dirty_write({Tab,7,-7})),
     File2 = "cp2_delete_me.BUP",
     ?match(ok, mnesia:backup_checkpoint(cp2, File2)),
-    
+
     ?match(ok, mnesia:deactivate_checkpoint(cp1)),
     ?match(ok, mnesia:backup_checkpoint(cp2, File1)),
     ?match(ok, mnesia:dirty_write({Tab,8,-8})),
-    
+
     ?match({atomic,ok}, mnesia:delete_table(Tab)),
     ?match({error,_}, mnesia:backup_checkpoint(cp2, File2)),
     ?match({'EXIT',_}, mnesia:dirty_write({Tab,9,-9})),
 
-    ?match({atomic,_}, mnesia:restore(File1, [{default_op, recreate_tables}])), 
+    ?match({atomic,_}, mnesia:restore(File1, [{default_op, recreate_tables}])),
     Test = fun(N) when N > 5 -> ?error("To many records in backup ~p ~n", [N]);
 	      (N) -> case mnesia:dirty_read(Tab,N) of
 			 [{Tab,N,B}] when -B =:= N -> ok;
@@ -759,8 +759,29 @@ sops_with_checkpoint(Config) when is_list(Config) ->
 		     end
 	   end,
     [Test(N) || N <- mnesia:dirty_all_keys(Tab)],
-    ?match({aborted,enoent}, mnesia:restore(File2, [{default_op, recreate_tables}])), 
-    
+    ?match({aborted,enoent}, mnesia:restore(File2, [{default_op, recreate_tables}])),
+
+    %% Mnesia crashes when deleting a table during backup
+    ?match([], mnesia_test_lib:stop_mnesia([N2])),
+    Tab2 = ram,
+    ?match({atomic, ok}, mnesia:create_table(Tab2, [{ram_copies,[N1]}])),
+    ?match({ok, cp3, _}, mnesia:activate_checkpoint([{name, cp3},
+                                                     {ram_overrides_dump,true},
+                                                     {min,[Tab2]}])),
+    Write = fun Loop (N) ->
+                   case N > 0 of
+                       true ->
+                           mnesia:dirty_write({Tab2, N+100, N+100}),
+                           Loop(N-1);
+                       false ->
+                           ok
+                   end
+           end,
+    ok = Write(100000),
+    spawn_link(fun() -> ?match({atomic, ok},mnesia:delete_table(Tab2)) end),
+
+    %% We don't check result here, depends on timing of above call
+    mnesia:backup_checkpoint(cp3, File2),
     file:delete(File1), file:delete(File2),
 
-    ?verify_mnesia(Ns, []).
+    ?verify_mnesia([N1], [N2]).