0001-HEAD-invalidate-newly-synchronized-slot.patch

From 8bbf1b200fb9f418286f837e8f6eb41c99f2890c Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Date: Tue, 11 Nov 2025 13:01:07 +0900
Subject: [PATCH] HEAD: invalidate newly synchronized slot

---
 src/backend/access/transam/xlog.c             |   3 +
 src/backend/replication/logical/slotsync.c    |   5 +
 src/test/recovery/meson.build                 |   1 +
 .../recovery/t/110_slot_sync_invalidation.pl  | 110 ++++++++++++++++++
 4 files changed, 119 insertions(+)
 create mode 100644 src/test/recovery/t/110_slot_sync_invalidation.pl

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 22d0a2e8c3a..49c22506e57 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7838,6 +7838,9 @@ CreateRestartPoint(int flags)
 	receivePtr = GetWalRcvFlushRecPtr(NULL, NULL);
 	replayPtr = GetXLogReplayRecPtr(&replayTLI);
 	endptr = (receivePtr < replayPtr) ? replayPtr : receivePtr;
+
+	INJECTION_POINT("restartpoint-before-old-wal-removal", NULL);
+
 	KeepLogSeg(endptr, &_logSegNo);
 	if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
 										   _logSegNo, InvalidOid,
diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c
index 8b4afd87dc9..64afca24960 100644
--- a/src/backend/replication/logical/slotsync.c
+++ b/src/backend/replication/logical/slotsync.c
@@ -64,6 +64,7 @@
 #include "storage/procarray.h"
 #include "tcop/tcopprot.h"
 #include "utils/builtins.h"
+#include "utils/injection_point.h"
 #include "utils/pg_lsn.h"
 #include "utils/ps_status.h"
 #include "utils/timeout.h"
@@ -497,10 +498,14 @@ reserve_wal_for_local_slot(XLogRecPtr restart_lsn)
 
 	while (true)
 	{
+		INJECTION_POINT("slotsync-reserve-wal", NULL);
+
 		SpinLockAcquire(&slot->mutex);
 		slot->data.restart_lsn = restart_lsn;
 		SpinLockRelease(&slot->mutex);
 
+		INJECTION_POINT("slotsync-reserve-wal-before-compute-required-lsn", NULL);
+
 		/* Prevent WAL removal as fast as possible */
 		ReplicationSlotsComputeRequiredLSN();
 
diff --git a/src/test/recovery/meson.build b/src/test/recovery/meson.build
index 523a5cd5b52..022af7b4c14 100644
--- a/src/test/recovery/meson.build
+++ b/src/test/recovery/meson.build
@@ -58,6 +58,7 @@ tests += {
       't/047_checkpoint_physical_slot.pl',
       't/048_vacuum_horizon_floor.pl',
       't/049_wait_for_lsn.pl',
+      't/110_slot_sync_invalidation.pl'
     ],
   },
 }
diff --git a/src/test/recovery/t/110_slot_sync_invalidation.pl b/src/test/recovery/t/110_slot_sync_invalidation.pl
new file mode 100644
index 00000000000..3dfabb6c2da
--- /dev/null
+++ b/src/test/recovery/t/110_slot_sync_invalidation.pl
@@ -0,0 +1,110 @@
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+	plan skip_all => 'Injection points not supported by this build';
+}
+
+# Create primary
+my $primary = PostgreSQL::Test::Cluster->new('primary');
+$primary->init(allows_streaming => 'logical');
+$primary->append_conf(
+		'postgresql.conf', qq(
+autovacuum = off
+checkpoint_timeout = 1h
+));
+$primary->start;
+
+# Create a standby from the backup
+my $backup_name = 'backup';
+$primary->backup($backup_name);
+
+my $standby = PostgreSQL::Test::Cluster->new('standby');
+$standby->init_from_backup(
+	$primary, $backup_name,
+	has_streaming => 1,
+	has_restoring => 1);
+
+my $connstr = $primary->connstr;
+$standby->append_conf(
+	'postgresql.conf', qq(
+hot_standby_feedback = on
+primary_slot_name = 'sb1_slot'
+primary_conninfo = '$connstr dbname=postgres'
+));
+
+# Install injection_point
+$primary->safe_psql('postgres', q{CREATE EXTENSION injection_points;});
+
+# Create a physical replication slot to synchronize logical slots
+$primary->safe_psql('postgres',
+	q{SELECT pg_create_physical_replication_slot('sb1_slot');});
+
+# Start the standby so that slot syncing can begin
+$standby->start;
+
+$primary->wait_for_replay_catchup($standby);
+
+# Create a logical replication slot to be synchronized
+$primary->safe_psql('postgres',
+	q{SELECT pg_create_logical_replication_slot('lsub1_slot', 'pgoutput', false, false, true);});
+
+$primary->advance_wal(6);
+
+$primary->wait_for_replay_catchup($standby);
+
+
+# Attach an injection point an try to synchronize the slot. It would stuck.
+$standby->safe_psql('postgres',
+	q{SELECT injection_points_attach('slotsync-reserve-wal', 'wait')});
+$standby->safe_psql('postgres',
+	q{SELECT injection_points_attach('slotsync-reserve-wal-before-compute-required-lsn', 'wait')});
+
+my $background1 = $standby->background_psql('postgres');
+$background1->query_until(
+	qr/slotsync-reserve-wal/,
+	q(\echo slotsync-reserve-wal
+	select pg_sync_replication_slots();
+	\q
+));
+
+$standby->wait_for_event('client backend', 'slotsync-reserve-wal');
+
+my $offset = -s $standby->logfile;
+
+$primary->safe_psql('postgres', q{CHECKPOINT});
+
+# Attach an injection point while running the RESTARTPOINT
+$standby->safe_psql('postgres',
+	q{SELECT injection_points_attach('restartpoint-before-old-wal-removal', 'wait')});
+my $background2 = $standby->background_psql('postgres');
+$background2->query_until(
+	qr/restartpoint-before-old-wal-removal/,
+	q(\echo restartpoint-before-old-wal-removal
+	CHECKPOINT;
+	\q
+));
+
+$standby->wait_for_event('checkpointer', 'restartpoint-before-old-wal-removal');
+
+# Wake up the backend and stop again at another injection point
+$standby->safe_psql('postgres',
+	q{SELECT injection_points_wakeup('slotsync-reserve-wal')});
+
+$standby->wait_for_event('client backend', 'slotsync-reserve-wal-before-compute-required-lsn');
+
+# Wake up the checkpointer to allow removing WALs.
+$standby->safe_psql('postgres',
+	q{SELECT injection_points_wakeup('restartpoint-before-old-wal-removal')});
+
+my $result = $standby->safe_psql('postgres',
+	q(SELECT slot_name FROM pg_replication_slots;));
+
+is($result, 'lsub1_slot', 'logical replication slot can be synchronized');
+done_testing();
-- 
2.47.3