Fix 2

Author: erikjohnston

synapse/storage/databases/main/events_bg_updates.py

@@ -767,7 +767,11 @@ def _get_event_ids(txn: Cursor) -> List[Tuple[str, int, int]]:
             event_ids, redact_behaviour=EventRedactBehaviour.AS_IS, allow_rejected=True
         )
 
-        await self.hs.get_datastores().persist_events._add_chain_info(events)
+        await self.runInteraction(
+            "_chain_cover_index_info",
+            self.hs.get_datastores().persist_events._add_chain_info,
+            events,
+        )
 
         if len(event_ids) < batch_size:
             await self.db_pool.updates._background_update_progress(