v2-0001-Fix-buffer-refcount-leak.patch

From 6d9da4ecfbca7addd0450c2f5bb359a47a0f4e98 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Mon, 24 Apr 2023 09:51:48 +0900
Subject: [PATCH v2] Fix buffer refcount leak

The buffer refcount leak was introduced
in b676ac443b6a83558d4701b2dd9491c0b37e17c4.
---
 src/backend/executor/nodeModifyTable.c        | 10 +++++++--
 .../postgres_fdw/expected/postgres_fdw.out    | 22 +++++++++++++++++++
 contrib/postgres_fdw/sql/postgres_fdw.sql     | 18 +++++++++++++++
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 6aa8c03def..dc1a2ec551 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -856,7 +856,6 @@ ExecInsert(ModifyTableContext *context,
 								resultRelInfo->ri_PlanSlots,
 								resultRelInfo->ri_NumSlots,
 								estate, canSetTag);
-				resultRelInfo->ri_NumSlots = 0;
 				flushed = true;
 			}
 
@@ -1261,6 +1260,14 @@ ExecBatchInsert(ModifyTableState *mtstate,
 
 	if (canSetTag && numInserted > 0)
 		estate->es_processed += numInserted;
+
+	/* Clean up all the slots, ready for the next batch */
+	for (i = 0; i < numSlots; i++)
+	{
+		ExecClearTuple(slots[i]);
+		ExecClearTuple(planSlots[i]);
+	}
+	resultRelInfo->ri_NumSlots = 0;
 }
 
 /*
@@ -1284,7 +1291,6 @@ ExecPendingInserts(EState *estate)
 						resultRelInfo->ri_PlanSlots,
 						resultRelInfo->ri_NumSlots,
 						estate, mtstate->canSetTag);
-		resultRelInfo->ri_NumSlots = 0;
 	}
 
 	list_free(estate->es_insert_pending_result_relations);
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index fd5752bd5b..826baac9f1 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -6930,6 +6930,28 @@ select * from grem1;
 (2 rows)
 
 delete from grem1;
+-- batch insert with foreign partitions.
+-- This schema uses two partitions, one local and one remote with a modulo
+-- to loop across all of them in batches.
+create table tab_batch_local (id int, data text);
+insert into tab_batch_local select i, 'test'|| i from generate_series(1, 45) i;
+create table tab_batch_sharded (id int, data text) partition by hash(id);
+create table tab_batch_sharded_p0 partition of tab_batch_sharded
+  for values with (modulus 2, remainder 0);
+create table tab_batch_sharded_p1_remote (id int, data text);
+create foreign table tab_batch_sharded_p1 partition of tab_batch_sharded
+  for values with (modulus 2, remainder 1)
+  server loopback options (table_name 'tab_batch_sharded_p1_remote');
+insert into tab_batch_sharded select * from tab_batch_local;
+select count(*) from tab_batch_sharded;
+ count 
+-------
+    45
+(1 row)
+
+drop table tab_batch_local;
+drop table tab_batch_sharded;
+drop table tab_batch_sharded_p1_remote;
 alter server loopback options (drop batch_size);
 -- ===================================================================
 -- test local triggers
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index c05046f867..15f3af6c29 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -1657,6 +1657,24 @@ insert into grem1 (a) values (1), (2);
 select * from gloc1;
 select * from grem1;
 delete from grem1;
+-- batch insert with foreign partitions.
+-- This schema uses two partitions, one local and one remote with a modulo
+-- to loop across all of them in batches.
+create table tab_batch_local (id int, data text);
+insert into tab_batch_local select i, 'test'|| i from generate_series(1, 45) i;
+create table tab_batch_sharded (id int, data text) partition by hash(id);
+create table tab_batch_sharded_p0 partition of tab_batch_sharded
+  for values with (modulus 2, remainder 0);
+create table tab_batch_sharded_p1_remote (id int, data text);
+create foreign table tab_batch_sharded_p1 partition of tab_batch_sharded
+  for values with (modulus 2, remainder 1)
+  server loopback options (table_name 'tab_batch_sharded_p1_remote');
+insert into tab_batch_sharded select * from tab_batch_local;
+select count(*) from tab_batch_sharded;
+drop table tab_batch_local;
+drop table tab_batch_sharded;
+drop table tab_batch_sharded_p1_remote;
+
 alter server loopback options (drop batch_size);
 
 -- ===================================================================
-- 
2.40.0