Port the deadlock-breaking code from bug 25852.

1 files changed, 14 insertions, 20 deletions

diff --git a/src/rabbit_mirror_queue_misc.erl b/src/rabbit_mirror_queue_misc.erl
index 8ad7c62f..47a44278 100644
--- a/src/rabbit_mirror_queue_misc.erl
+++ b/src/rabbit_mirror_queue_misc.erl
@@ -19,7 +19,8 @@
 
 -export([remove_from_queue/3, on_node_up/0, add_mirrors/2, add_mirror/2,
          report_deaths/4, store_updated_slaves/1, suggested_queue_nodes/1,
-         is_mirrored/1, update_mirrors/2, validate_policy/1]).
+         is_mirrored/1, update_mirrors/2, validate_policy/1,
+         maybe_auto_sync/1]).
 
 %% for testing only
 -export([module/1]).
@@ -94,10 +95,14 @@ remove_from_queue(QueueName, Self, LiveGMPids) ->
                               %% Either master hasn't changed, so
                               %% we're ok to update mnesia; or we have
                               %% become the master.
-                              store_updated_slaves(
-                                Q #amqqueue { pid        = QPid1,
+                              Q1 = Q#amqqueue{pid        = QPid1,
                                               slave_pids = SPids1,
-                                              gm_pids    = GMPids1 }),
+                                              gm_pids    = GMPids1},
+                              store_updated_slaves(Q1),
+                              %% If we add and remove nodes at the same time
+                              %% it's possible we need to sync after removing
+                              %% the master. Let's check.
+                              maybe_auto_sync(Q1),
                               {ok, QPid1, [QPid | SPids] -- Alive};
                           _ ->
                               %% Master has changed, and we're not it,
@@ -179,26 +184,15 @@ add_mirror(QName, MirrorNode) ->
               end
       end).
 
-start_child(Name, MirrorNode, Q) ->
+start_child(_Name, MirrorNode, Q) ->
+    %% TODO re-add some log stuff here.
     case rabbit_misc:with_exit_handler(
-           rabbit_misc:const({ok, down}),
+           rabbit_misc:const(down),
            fun () ->
                    rabbit_mirror_queue_slave_sup:start_child(MirrorNode, [Q])
            end) of
-        {ok, SPid} when is_pid(SPid)  ->
-            maybe_auto_sync(Q),
-            rabbit_log:info("Adding mirror of ~s on node ~p: ~p~n",
-                            [rabbit_misc:rs(Name), MirrorNode, SPid]),
-            {ok, started};
-        {error, {{stale_master_pid, StalePid}, _}} ->
-            rabbit_log:warning("Detected stale HA master while adding "
-                               "mirror of ~s on node ~p: ~p~n",
-                               [rabbit_misc:rs(Name), MirrorNode, StalePid]),
-            {ok, stale_master};
-        {error, {{duplicate_live_master, _}=Err, _}} ->
-            Err;
-        Other ->
-            Other
+        {ok, SPid} -> rabbit_mirror_queue_slave:go(SPid);
+        _          -> ok
     end.
 
 report_deaths(_MirrorPid, _IsMaster, _QueueName, []) ->