Remove account data (including client config, push rules and ignored users) upon user deactivation. (#11621)

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

2 files changed, 74 insertions, 2 deletions

diff --git a/synapse/handlers/deactivate_account.py b/synapse/handlers/deactivate_account.py
index bee62cf360..7a13d76a68 100644
--- a/synapse/handlers/deactivate_account.py
+++ b/synapse/handlers/deactivate_account.py
@@ -157,6 +157,9 @@ class DeactivateAccountHandler:
         # Mark the user as deactivated.
         await self.store.set_user_deactivated_status(user_id, True)
 
+        # Remove account data (including ignored users and push rules).
+        await self.store.purge_account_data_for_user(user_id)
+
         return identity_server_supports_unbinding
 
     async def _reject_pending_invites_for_user(self, user_id: str) -> None:
diff --git a/synapse/storage/databases/main/account_data.py b/synapse/storage/databases/main/account_data.py
index 9c19f0965f..5bfa408f74 100644
--- a/synapse/storage/databases/main/account_data.py
+++ b/synapse/storage/databases/main/account_data.py
@@ -26,6 +26,7 @@ from synapse.storage.database import (
     LoggingTransaction,
 )
 from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore
+from synapse.storage.databases.main.push_rule import PushRulesWorkerStore
 from synapse.storage.engines import PostgresEngine
 from synapse.storage.util.id_generators import (
     AbstractStreamIdGenerator,
@@ -44,7 +45,7 @@ if TYPE_CHECKING:
 logger = logging.getLogger(__name__)
 
 
-class AccountDataWorkerStore(CacheInvalidationWorkerStore):
+class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore):
     def __init__(
         self,
         database: DatabasePool,
@@ -179,7 +180,7 @@ class AccountDataWorkerStore(CacheInvalidationWorkerStore):
         else:
             return None
 
-    @cached(num_args=2)
+    @cached(num_args=2, tree=True)
     async def get_account_data_for_room(
         self, user_id: str, room_id: str
     ) -> Dict[str, JsonDict]:
@@ -546,6 +547,74 @@ class AccountDataWorkerStore(CacheInvalidationWorkerStore):
         for ignored_user_id in previously_ignored_users ^ currently_ignored_users:
             self._invalidate_cache_and_stream(txn, self.ignored_by, (ignored_user_id,))
 
+    async def purge_account_data_for_user(self, user_id: str) -> None:
+        """
+        Removes the account data for a user.
+
+        This is intended to be used upon user deactivation and also removes any
+        derived information from account data (e.g. push rules and ignored users).
+
+        Args:
+            user_id: The user ID to remove data for.
+        """
+
+        def purge_account_data_for_user_txn(txn: LoggingTransaction) -> None:
+            # Purge from the primary account_data tables.
+            self.db_pool.simple_delete_txn(
+                txn, table="account_data", keyvalues={"user_id": user_id}
+            )
+
+            self.db_pool.simple_delete_txn(
+                txn, table="room_account_data", keyvalues={"user_id": user_id}
+            )
+
+            # Purge from ignored_users where this user is the ignorer.
+            # N.B. We don't purge where this user is the ignoree, because that
+            #      interferes with other users' account data.
+            #      It's also not this user's data to delete!
+            self.db_pool.simple_delete_txn(
+                txn, table="ignored_users", keyvalues={"ignorer_user_id": user_id}
+            )
+
+            # Remove the push rules
+            self.db_pool.simple_delete_txn(
+                txn, table="push_rules", keyvalues={"user_name": user_id}
+            )
+            self.db_pool.simple_delete_txn(
+                txn, table="push_rules_enable", keyvalues={"user_name": user_id}
+            )
+            self.db_pool.simple_delete_txn(
+                txn, table="push_rules_stream", keyvalues={"user_id": user_id}
+            )
+
+            # Invalidate caches as appropriate
+            self._invalidate_cache_and_stream(
+                txn, self.get_account_data_for_room_and_type, (user_id,)
+            )
+            self._invalidate_cache_and_stream(
+                txn, self.get_account_data_for_user, (user_id,)
+            )
+            self._invalidate_cache_and_stream(
+                txn, self.get_global_account_data_by_type_for_user, (user_id,)
+            )
+            self._invalidate_cache_and_stream(
+                txn, self.get_account_data_for_room, (user_id,)
+            )
+            self._invalidate_cache_and_stream(
+                txn, self.get_push_rules_for_user, (user_id,)
+            )
+            self._invalidate_cache_and_stream(
+                txn, self.get_push_rules_enabled_for_user, (user_id,)
+            )
+            # This user might be contained in the ignored_by cache for other users,
+            # so we have to invalidate it all.
+            self._invalidate_all_cache_and_stream(txn, self.ignored_by)
+
+        await self.db_pool.runInteraction(
+            "purge_account_data_for_user_txn",
+            purge_account_data_for_user_txn,
+        )
+
 
 class AccountDataStore(AccountDataWorkerStore):
     pass