From 6ba2b5402c3dea5b765034436ae9e6b3ca4e2ce5 Mon Sep 17 00:00:00 2001
From: Dan Gudmundsson <dgud@erlang.org>
Date: Wed, 27 Aug 2014 09:00:14 +0200
Subject: Avoid timing issue in schema transaction when node is stopping

By doing an abort, the create_table can be restarted
if a node go down during the transaction.

{badarg,
   [{erlang,link,[undefined],[]},
    {mnesia_controller,
        wait_for_schema_commit_lock,0,
	       [{file,"mnesia_controller.erl"},
         {line,303}]},
    {mnesia_schema,prepare_commit,3,
        [{file,"mnesia_schema.erl"},
         {line,1838}]},
    {mnesia_tm,commit_participant,6,
        [{file,"mnesia_tm.erl"},
         {line,1669}]}]}}},
---
 lib/mnesia/src/mnesia_controller.erl | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

(limited to 'lib/mnesia/src')

diff --git a/lib/mnesia/src/mnesia_controller.erl b/lib/mnesia/src/mnesia_controller.erl
index fe2fd67d71..5a9bae54da 100644
--- a/lib/mnesia/src/mnesia_controller.erl
+++ b/lib/mnesia/src/mnesia_controller.erl
@@ -300,8 +300,13 @@ mnesia_down(Node) ->
     end.
 
 wait_for_schema_commit_lock() ->
-    link(whereis(?SERVER_NAME)),
-    unsafe_call(wait_for_schema_commit_lock).
+    try
+	Pid = whereis(?SERVER_NAME),
+	link(Pid), %% Keep the link until release_schema_commit_lock
+	gen_server:call(Pid, wait_for_schema_commit_lock, infinity)
+    catch _:_ ->
+	    mnesia:abort({node_not_running, node()})
+    end.
 
 block_controller() ->
     call(block_controller).
@@ -557,12 +562,6 @@ cast(Msg) ->
 abcast(Nodes, Msg) ->
     gen_server:abcast(Nodes, ?SERVER_NAME, Msg).
 
-unsafe_call(Msg) ->
-    case whereis(?SERVER_NAME) of
-	undefined -> {error, {node_not_running, node()}};
-	Pid -> gen_server:call(Pid, Msg, infinity)
-    end.
-
 call(Msg) ->
     case whereis(?SERVER_NAME) of
 	undefined ->
-- 
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