ResolveActivityObjectConflicts: lock tables, disable fkey constraints for transaction

2 files changed, 17 insertions, 1 deletions

diff --git a/priv/repo/migrations/20211218181640_resolve_activity_object_conflicts.exs b/priv/repo/migrations/20211218181640_resolve_activity_object_conflicts.exs
index 2c24c32f3..28700d3d8 100644
--- a/priv/repo/migrations/20211218181640_resolve_activity_object_conflicts.exs
+++ b/priv/repo/migrations/20211218181640_resolve_activity_object_conflicts.exs
@@ -12,6 +12,17 @@ defmodule Pleroma.Repo.Migrations.ResolveActivityObjectConflicts do
   import Ecto.Query
 
   def up do
+    # Lock relevant tables
+    execute("LOCK TABLE objects")
+    execute("LOCK TABLE chat_message_references")
+    execute("LOCK TABLE deliveries")
+    execute("LOCK TABLE hashtags_objects")
+
+    # Temporarily disable fkey constraints
+    disable_constraint("chat_message_references", "chat_message_references_object_id_fkey")
+    disable_constraint("deliveries", "deliveries_object_id_fkey")
+    disable_constraint("hashtags_objects", "hashtags_objects_object_id_fkey")
+
     activity_conflict_query()
     |> Repo.stream()
     |> Stream.each(&update_object/1)
@@ -32,4 +43,9 @@ defmodule Pleroma.Repo.Migrations.ResolveActivityObjectConflicts do
   def down do
     :ok
   end
+
+  # https://stackoverflow.com/a/48335239
+  defp disable_constraint(table, constraint) do
+    execute("ALTER TABLE #{table} ALTER CONSTRAINT #{constraint} DEFERRABLE INITIALLY DEFERRED")
+  end
 end
diff --git a/priv/repo/migrations/20211218181647_combine_activities_and_objects.exs b/priv/repo/migrations/20211218181647_combine_activities_and_objects.exs
index bc692d99d..09eb10a58 100644
--- a/priv/repo/migrations/20211218181647_combine_activities_and_objects.exs
+++ b/priv/repo/migrations/20211218181647_combine_activities_and_objects.exs
@@ -7,7 +7,7 @@ defmodule Pleroma.Repo.Migrations.CombineActivitiesAndObjects do
   def up do
     # Lock both tables to avoid a running server meddling with our transaction
     execute("LOCK TABLE activities")
-    execute("LOCK TABLE users")
+    execute("LOCK TABLE objects")
 
     # Add missing fields to objects table
     alter table(:objects) do