Add citus.skip_advisory_lock_permission_checks (#6293)

src/backend/distributed/shared_library_init.c

@@ -2076,6 +2076,20 @@ RegisterCitusConfigVariables(void)
 		ShowShardsForAppNamePrefixesAssignHook,
 		NULL);
 
+	DefineCustomBoolVariable(
+		"citus.skip_advisory_lock_permission_checks",
+		gettext_noop("Postgres would normally enforce some "
+					 "ownership checks while acquiring locks. "
+					 "When this setting is 'off', Citus skips"
+					 "ownership checks on internal advisory "
+					 "locks."),
+		NULL,
+		&SkipAdvisoryLockPermissionChecks,
+		false,
+		GUC_SUPERUSER_ONLY,
+		GUC_NO_SHOW_ALL,
+		NULL, NULL, NULL);
+
 	DefineCustomBoolVariable(
 		"citus.skip_jsonb_validation_in_copy",
 		gettext_noop("Skip validation of JSONB columns on the coordinator during COPY "

src/backend/distributed/utils/resource_lock.c

@@ -109,6 +109,8 @@ PG_FUNCTION_INFO_V1(lock_relation_if_exists);
 
 /* Config variable managed via guc.c */
 bool EnableAcquiringUnsafeLockFromWorkers = false;
+bool SkipAdvisoryLockPermissionChecks = false;
+
 
 /*
  * lock_shard_metadata allows the shard distribution metadata to be locked
@@ -248,7 +250,10 @@ lock_shard_resources(PG_FUNCTION_ARGS)
 			continue;
 		}
 
-		EnsureTablePermissions(relationId, aclMask);
+		if (!SkipAdvisoryLockPermissionChecks)
+		{
+			EnsureTablePermissions(relationId, aclMask);
+		}
 
 		LockShardResource(shardId, lockMode);
 	}

src/include/distributed/resource_lock.h

@@ -149,6 +149,7 @@ enum DistLockConfigs
 	DIST_LOCK_NOWAIT = 2
 };
 
+
 /* Lock shard/relation metadata for safe modifications */
 extern void LockShardDistributionMetadata(int64 shardId, LOCKMODE lockMode);
 extern void LockPlacementCleanup(void);
@@ -194,5 +195,6 @@ extern void AcquireDistributedLockOnRelations(List *relationList, LOCKMODE lockM
 extern void PreprocessLockStatement(LockStmt *stmt, ProcessUtilityContext context);
 
 extern bool EnableAcquiringUnsafeLockFromWorkers;
+extern bool SkipAdvisoryLockPermissionChecks;
 
 #endif /* RESOURCE_LOCK_H */

src/test/regress/expected/adv_lock_permission.out

@@ -0,0 +1,41 @@
+CREATE SCHEMA adv_lock_permission;
+SET search_path to adv_lock_permission;
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+CREATE ROLE user_1 WITH LOGIN;
+CREATE TABLE reference_table_1 (A int);
+SELECT create_reference_table('reference_table_1');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+CREATE TABLE reference_table_2 (A int);
+SELECT create_reference_table('reference_table_2');
+ create_reference_table
+---------------------------------------------------------------------
+
+(1 row)
+
+GRANT USAGE ON SCHEMA adv_lock_permission TO user_1;
+GRANT SELECT ON reference_table_1 TO user_1;
+GRANT INSERT, UPDATE ON reference_table_2 TO user_1;
+SET ROLE user_1;
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+SET search_path to adv_lock_permission;
+INSERT INTO reference_table_2 SELECT * FROM reference_table_1;
+ERROR:  permission denied for table reference_table_1
+CONTEXT:  while executing command on localhost:xxxxx
+SET ROLE postgres;
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+-- change the role so that it can skip permission checks
+ALTER ROLE user_1 SET citus.skip_advisory_lock_permission_checks TO on;
+SET ROLE user_1;
+SET citus.max_cached_conns_per_worker TO 0;
+INSERT INTO reference_table_2 SELECT * FROM reference_table_1;
+SET ROLE postgres;
+SET client_min_messages TO ERROR;
+DROP SCHEMA adv_lock_permission CASCADE;
+DROP ROLE user_1;

src/test/regress/multi_schedule

@@ -86,7 +86,7 @@ test: multi_agg_type_conversion multi_count_type_conversion recursive_relation_p
 test: multi_partition_pruning single_hash_repartition_join unsupported_lateral_subqueries
 test: multi_join_pruning multi_hash_pruning intermediate_result_pruning
 test: multi_null_minmax_value_pruning cursors
-test: modification_correctness
+test: modification_correctness adv_lock_permission
 test: multi_query_directory_cleanup
 test: multi_task_assignment_policy multi_cross_shard
 test: multi_utility_statements

src/test/regress/sql/adv_lock_permission.sql

@@ -0,0 +1,42 @@
+CREATE SCHEMA adv_lock_permission;
+SET search_path to adv_lock_permission;
+
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+
+CREATE ROLE user_1 WITH LOGIN;
+
+CREATE TABLE reference_table_1 (A int);
+SELECT create_reference_table('reference_table_1');
+
+CREATE TABLE reference_table_2 (A int);
+SELECT create_reference_table('reference_table_2');
+
+GRANT USAGE ON SCHEMA adv_lock_permission TO user_1;
+GRANT SELECT ON reference_table_1 TO user_1;
+GRANT INSERT, UPDATE ON reference_table_2 TO user_1;
+
+SET ROLE user_1;
+
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+SET search_path to adv_lock_permission;
+
+INSERT INTO reference_table_2 SELECT * FROM reference_table_1;
+
+SET ROLE postgres;
+-- do not cache any connections, we change some settings and don't want old ones cached
+SET citus.max_cached_conns_per_worker TO 0;
+
+-- change the role so that it can skip permission checks
+ALTER ROLE user_1 SET citus.skip_advisory_lock_permission_checks TO on;
+
+SET ROLE user_1;
+
+SET citus.max_cached_conns_per_worker TO 0;
+INSERT INTO reference_table_2 SELECT * FROM reference_table_1;
+
+SET ROLE postgres;
+SET client_min_messages TO ERROR;
+DROP SCHEMA adv_lock_permission CASCADE;
+DROP ROLE user_1;