POC_test.diff.txt
text/plain
Filename: POC_test.diff.txt
Type: text/plain
Part: 8
commit f502fa990e877c6e4d1d03518e524519d8e88806
Author: Tomas Vondra <tomas@vondra.me>
Date: Wed Apr 15 12:50:06 2026 +0200
POC: Test checksum state transitions using step through injection points
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index be92b6af20f..5b481784543 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4762,6 +4762,9 @@ SetDataChecksumsOnInProgress(void)
uint32 data_checksum_version;
elog(LOG, "SetDataChecksumsOnInProgress / start");
+
+ INJECTION_POINT("datachecksums-enable-inprogress-checksums-delay", NULL);
+
/*
* The state transition is performed in a critical section with
* checkpoints held off to provide crash safety.
@@ -4782,6 +4785,8 @@ SetDataChecksumsOnInProgress(void)
MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
END_CRIT_SECTION();
+ INJECTION_POINT("datachecksums-enable-inprogress-checksums-after-xlogctl", NULL);
+
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
elog(LOG, "SetDataChecksumsOnInProgress ControlFile->data_checksum_version %u => %u",
@@ -4791,6 +4796,8 @@ SetDataChecksumsOnInProgress(void)
UpdateControlFile();
LWLockRelease(ControlFileLock);
+ INJECTION_POINT("datachecksums-enable-inprogress-checksums-after-controlfile", NULL);
+
elog(LOG, "SetDataChecksumsOnInProgress / EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_INPROGRESS_ON)");
EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_INPROGRESS_ON);
@@ -4862,6 +4869,8 @@ SetDataChecksumsOn(void)
MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
END_CRIT_SECTION();
+ INJECTION_POINT("datachecksums-enable-checksums-after-xlogctl", NULL);
+
/*
* Update the controlfile before waiting since if we have an immediate
* shutdown while waiting we want to come back up with checksums enabled.
@@ -4875,9 +4884,13 @@ SetDataChecksumsOn(void)
UpdateControlFile();
LWLockRelease(ControlFileLock);
+ INJECTION_POINT("datachecksums-enable-checksums-after-controlfile", NULL);
+
elog(LOG, "SetDataChecksumsOn / RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST)");
RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
+ INJECTION_POINT("datachecksums-enable-checksums-after-checkpoint", NULL);
+
elog(LOG, "SetDataChecksumsOn / EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_VERSION)");
EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_VERSION);
@@ -4924,6 +4937,8 @@ SetDataChecksumsOff(void)
{
SpinLockRelease(&XLogCtl->info_lck);
+ INJECTION_POINT("datachecksums-disable-inprogress-checksums-delay", NULL);
+
START_CRIT_SECTION();
MyProc->delayChkptFlags |= DELAY_CHKPT_START;
@@ -4934,24 +4949,30 @@ SetDataChecksumsOff(void)
XLogCtl->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_OFF;
SpinLockRelease(&XLogCtl->info_lck);
- elog(LOG, "SetDataChecksumsOff / XLogCtl->data_checksum_version %u = %u",
+ elog(LOG, "SetDataChecksumsOff / XLogCtl->data_checksum_version %u => %u",
data_checksum_version, PG_DATA_CHECKSUM_INPROGRESS_OFF);
MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
END_CRIT_SECTION();
+ INJECTION_POINT("datachecksums-disable-inprogress-checksums-after-xlogctl", NULL);
+
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
- elog(LOG, "SetDataChecksumsOff / ControlFile->data_checksum_version %u = %u",
+ elog(LOG, "SetDataChecksumsOff / ControlFile->data_checksum_version %u => %u",
ControlFile->data_checksum_version, PG_DATA_CHECKSUM_INPROGRESS_OFF);
ControlFile->data_checksum_version = PG_DATA_CHECKSUM_INPROGRESS_OFF;
UpdateControlFile();
LWLockRelease(ControlFileLock);
+ INJECTION_POINT("datachecksums-disable-inprogress-checksums-after-controlfile", NULL);
+
elog(LOG, "SetDataChecksumsOff / RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST)");
RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
+ INJECTION_POINT("datachecksums-disable-inprogress-checksums-after-checkpoint", NULL);
+
elog(LOG, "SetDataChecksumsOff / EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_INPROGRESS_OFF)");
EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_INPROGRESS_OFF);
@@ -4971,6 +4992,8 @@ SetDataChecksumsOff(void)
SpinLockRelease(&XLogCtl->info_lck);
}
+ INJECTION_POINT("datachecksums-disable-checksums-delay", NULL);
+
START_CRIT_SECTION();
/* Ensure that we don't incur a checkpoint during disabling checksums */
MyProc->delayChkptFlags |= DELAY_CHKPT_START;
@@ -4988,6 +5011,8 @@ SetDataChecksumsOff(void)
MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
END_CRIT_SECTION();
+ INJECTION_POINT("datachecksums-disable-checksums-after-xlogctl", NULL);
+
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
elog(LOG, "SetDataChecksumsOff / ControlFile->data_checksum_version %u => %u",
@@ -4997,9 +5022,13 @@ SetDataChecksumsOff(void)
UpdateControlFile();
LWLockRelease(ControlFileLock);
+ INJECTION_POINT("datachecksums-disable-checksums-after-controlfile", NULL);
+
elog(LOG, "SetDataChecksumsOff / RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST)");
RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_FAST);
+ INJECTION_POINT("datachecksums-disable-checksums-after-checkpoint", NULL);
+
elog(LOG, "SetDataChecksumsOff / EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_OFF)");
EmitAndWaitDataChecksumsBarrier(PG_DATA_CHECKSUM_OFF);
diff --git a/src/test/modules/test_checksums/t/010_injection_2.pl b/src/test/modules/test_checksums/t/010_injection_2.pl
new file mode 100644
index 00000000000..a8ae9ffd151
--- /dev/null
+++ b/src/test/modules/test_checksums/t/010_injection_2.pl
@@ -0,0 +1,209 @@
+
+# Copyright (c) 2026, PostgreSQL Global Development Group
+
+# Test suite for testing enabling data checksums in an online cluster with
+# injection point tests injecting failures into the processing
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+use FindBin;
+use lib $FindBin::RealBin;
+
+use DataChecksums::Utils;
+
+# This test suite is expensive, or very expensive, to execute. There are two
+# PG_TEST_EXTRA options for running it, "checksum" for a pared-down test suite
+# an "checksum_extended" for the full suite. The full suite can run for hours
+# on slow or constrained systems.
+my $extended = undef;
+if ($ENV{PG_TEST_EXTRA})
+{
+ $extended = 1 if ($ENV{PG_TEST_EXTRA} =~ /\bchecksum_extended\b/);
+ plan skip_all => 'Expensive data checksums test disabled'
+ unless ($ENV{PG_TEST_EXTRA} =~ /\bchecksum(_extended)?\b/);
+}
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+ plan skip_all => 'Injection points not supported by this build';
+}
+
+# ---------------------------------------------------------------------------
+# Test cluster setup
+#
+
+# Initiate testcluster
+my $node = PostgreSQL::Test::Cluster->new('injection_node');
+$node->init(no_data_checksums => 1);
+$node->start;
+
+# Set up test environment
+$node->safe_psql('postgres', 'CREATE EXTENSION test_checksums;');
+$node->safe_psql('postgres', 'CREATE EXTENSION injection_points;');
+
+my $pgbench = undef;
+my $scalefactor = ($extended ? 10 : 1);
+my $node_loglocation = 0;
+
+$node->command_ok(
+ [
+ 'pgbench', '-p', $node->port, '-i',
+ '-s', $scalefactor, '-q', 'postgres'
+ ]);
+
+# Start a pgbench run in the background against the server specified via the
+# port passed as parameter.
+sub background_rw_pgbench
+{
+ my $port = shift;
+
+ # If a previous pgbench is still running, start by shutting it down.
+ $pgbench->finish if $pgbench;
+
+ my $clients = 1;
+ my $runtime = 2;
+
+ if ($extended)
+ {
+ # Randomize the number of pgbench clients a bit (range 1-16)
+ $clients = 1 + int(rand(15));
+ $runtime = 600;
+ }
+ my @cmd = ('pgbench', '-p', $port, '-T', $runtime, '-c', $clients);
+
+ # Randomize whether we spawn connections or not
+ push(@cmd, '-C') if ($extended && cointoss);
+ # Finally add the database name to use
+ push(@cmd, 'postgres');
+
+ $pgbench = IPC::Run::start(
+ \@cmd,
+ '<' => '/dev/null',
+ '>' => '/dev/null',
+ '2>' => '/dev/null',
+ IPC::Run::timer($PostgreSQL::Test::Utils::timeout_default));
+}
+
+# Test checksum transition. The function has these arguments:
+#
+# - start checksum state (enabled/disabled)
+# - first - first checksum change
+# - second - second checksum change
+# - point - injection point the first change should wait on
+# - final - expected checksum state at the end
+#
+# The test puts the instance into the initial checksum state, triggers two
+# checksum changes, and verifies the final state is as expected. The first
+# state change is paused on a selected injection point, and unpaused after
+# the second change gets initiated.
+#
+# The injection point is triggered only by the datachecksum launcher, and
+# there can be only one such process. So there's no risk of hitting the
+# injection point by both changes.
+sub test_checksum_transition
+{
+ my ($start, $first, $second, $point, $final) = @_;
+
+ $node->safe_psql('postgres',
+ "SELECT '========== " . $start . " / " . $first . " / " . $second . " / " . $point . " / " . $final . " =========='");
+
+ note($start . " / " . $first . " / " . $second . " / " . $point . " / " . $final);
+
+ note('changing checksums into initial state: ' . $start);
+
+ enable_data_checksums($node, wait => 'on') if ($start eq 'enabled');
+ disable_data_checksums($node, wait => 'off') if ($start eq 'disabled');
+
+ note('attaching injection point: ' . $point);
+ $node->safe_psql('postgres',
+ "SELECT injection_points_attach('" . $point . "','wait');"
+ );
+
+ note("triggering first checksum change: " . $first);
+
+ enable_data_checksums($node) if ($first eq 'enable');
+ disable_data_checksums($node) if ($first eq 'disable');
+
+ note("waiting for the injection point to be hit");
+ $node->poll_query_until(
+ 'postgres',
+ "SELECT COUNT(*) FROM pg_catalog.pg_stat_activity WHERE wait_event = '" . $point . "'",
+ '1');
+
+ note("triggering second checksum change: " . $second);
+
+ enable_data_checksums($node) if ($second eq 'enable');
+ disable_data_checksums($node) if ($second eq 'disable');
+
+ note("waking and detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_wakeup('" . $point . "');");
+
+ note("detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_detach('" . $point . "');");
+
+ note('wait for the checksum launcher to exit');
+ $node->poll_query_until('postgres',
+ "SELECT count(*) = 0 "
+ . "FROM pg_catalog.pg_stat_activity "
+ . "WHERE backend_type = 'datachecksum launcher';");
+
+ test_checksum_state($node, $final);
+
+ # Since the log isn't being written to now, parse the log and check
+ # for instances of checksum verification failures.
+ my $log = PostgreSQL::Test::Utils::slurp_file($node->logfile,
+ $node_loglocation);
+ unlike(
+ $log,
+ qr/page verification failed,.+\d$/,
+ "no checksum validation errors in primary log (during WAL recovery)"
+ );
+ $node_loglocation = -s $node->logfile;
+}
+
+# Start the test suite with pgbench running.
+background_rw_pgbench($node->port);
+
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-inprogress-checksums-delay', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-inprogress-checksums-after-xlogctl', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-inprogress-checksums-after-controlfile', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-checksums-delay', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-checksums-after-xlogctl', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-checksums-after-controlfile', 'off');
+test_checksum_transition('disabled', 'enable', 'disable', 'datachecksums-enable-checksums-after-checkpoint', 'off');
+
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-inprogress-checksums-delay', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-inprogress-checksums-after-xlogctl', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-inprogress-checksums-after-controlfile', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-checksums-delay', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-checksums-after-xlogctl', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-checksums-after-controlfile', 'on');
+test_checksum_transition('disabled', 'enable', 'enable', 'datachecksums-enable-checksums-after-checkpoint', 'on');
+
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-inprogress-checksums-delay', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-inprogress-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-inprogress-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-inprogress-checksums-after-checkpoint', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-checksums-delay', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'disable', 'datachecksums-disable-checksums-after-checkpoint', 'off');
+
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-inprogress-checksums-delay', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-inprogress-checksums-after-xlogctl', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-inprogress-checksums-after-controlfile', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-inprogress-checksums-after-checkpoint', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-checksums-delay', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-checksums-after-xlogctl', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-checksums-after-controlfile', 'on');
+test_checksum_transition('enabled', 'disable', 'enable', 'datachecksums-disable-checksums-after-checkpoint', 'on');
+
+$node->stop;
+done_testing();
diff --git a/src/test/modules/test_checksums/t/011_injection_checkpoint.pl b/src/test/modules/test_checksums/t/011_injection_checkpoint.pl
new file mode 100644
index 00000000000..ce1553e8ecd
--- /dev/null
+++ b/src/test/modules/test_checksums/t/011_injection_checkpoint.pl
@@ -0,0 +1,196 @@
+
+# Copyright (c) 2026, PostgreSQL Global Development Group
+
+# Test suite for testing enabling data checksums in an online cluster with
+# injection point tests injecting failures into the processing
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+use FindBin;
+use lib $FindBin::RealBin;
+
+use DataChecksums::Utils;
+
+# This test suite is expensive, or very expensive, to execute. There are two
+# PG_TEST_EXTRA options for running it, "checksum" for a pared-down test suite
+# an "checksum_extended" for the full suite. The full suite can run for hours
+# on slow or constrained systems.
+my $extended = undef;
+if ($ENV{PG_TEST_EXTRA})
+{
+ $extended = 1 if ($ENV{PG_TEST_EXTRA} =~ /\bchecksum_extended\b/);
+ plan skip_all => 'Expensive data checksums test disabled'
+ unless ($ENV{PG_TEST_EXTRA} =~ /\bchecksum(_extended)?\b/);
+}
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+ plan skip_all => 'Injection points not supported by this build';
+}
+
+# ---------------------------------------------------------------------------
+# Test cluster setup
+#
+
+# Initiate testcluster
+my $node = PostgreSQL::Test::Cluster->new('injection_node');
+$node->init(no_data_checksums => 1);
+$node->start;
+
+# Set up test environment
+$node->safe_psql('postgres', 'CREATE EXTENSION test_checksums;');
+$node->safe_psql('postgres', 'CREATE EXTENSION injection_points;');
+
+my $pgbench = undef;
+my $scalefactor = ($extended ? 10 : 1);
+my $node_loglocation = 0;
+
+$node->command_ok(
+ [
+ 'pgbench', '-p', $node->port, '-i',
+ '-s', $scalefactor, '-q', 'postgres'
+ ]);
+
+# Start a pgbench run in the background against the server specified via the
+# port passed as parameter.
+sub background_rw_pgbench
+{
+ my $port = shift;
+
+ # If a previous pgbench is still running, start by shutting it down.
+ $pgbench->finish if $pgbench;
+
+ my $clients = 1;
+ my $runtime = 2;
+
+ if ($extended)
+ {
+ # Randomize the number of pgbench clients a bit (range 1-16)
+ $clients = 1 + int(rand(15));
+ $runtime = 600;
+ }
+ my @cmd = ('pgbench', '-p', $port, '-T', $runtime, '-c', $clients);
+
+ # Randomize whether we spawn connections or not
+ push(@cmd, '-C') if ($extended && cointoss);
+ # Finally add the database name to use
+ push(@cmd, 'postgres');
+
+ $pgbench = IPC::Run::start(
+ \@cmd,
+ '<' => '/dev/null',
+ '>' => '/dev/null',
+ '2>' => '/dev/null',
+ IPC::Run::timer($PostgreSQL::Test::Utils::timeout_default));
+}
+
+# Test checksum transition concurrent with a checkpoint.
+#
+# The function has these arguments:
+#
+# - start checksum state (enabled/disabled)
+# - change - checksum change to initiate
+# - point - injection point the first change should wait on
+# - final - expected checksum state at the end
+#
+# The test puts the instance into the initial checksum state, triggers a
+# checksum change concurrent with a checkpoint, and verifies the final state
+# is as expected. The state change is paused on a selected injection
+# point, and unpaused after performing a checkpoint.
+#
+# Finally, the instance is restarted (in either fast ot immediate mode),
+# the final checksum state is validated against the expected value, and
+# the server log is checked for checksum failures.
+sub test_checksum_transition
+{
+ my ($start, $change, $point, $final) = @_;
+
+ # Start the test suite with pgbench running.
+ background_rw_pgbench($node->port);
+
+ $node->safe_psql('postgres',
+ "SELECT '========== " . $start . " / " . $change . " / " . $point . " / " . $final . " =========='");
+
+ note($start . " / " . $change . " / " . $point . " / " . $final);
+
+ note('changing checksums into initial state: ' . $start);
+
+ enable_data_checksums($node, wait => 'on') if ($start eq 'enabled');
+ disable_data_checksums($node, wait => 'off') if ($start eq 'disabled');
+
+ note('attaching injection point: ' . $point);
+ $node->safe_psql('postgres',
+ "SELECT injection_points_attach('" . $point . "','wait');"
+ );
+
+ note("triggering checksum change: " . $change);
+
+ enable_data_checksums($node) if ($change eq 'enable');
+ disable_data_checksums($node) if ($change eq 'disable');
+
+ note("waiting for the injection point to be hit");
+ $node->poll_query_until(
+ 'postgres',
+ "SELECT COUNT(*) FROM pg_catalog.pg_stat_activity WHERE wait_event = '" . $point . "'",
+ '1');
+
+ note('checkpoint');
+ $node->safe_psql('postgres', "CHECKPOINT");
+
+ note("waking and detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_wakeup('" . $point . "');");
+
+ note("detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_detach('" . $point . "');");
+
+ note('wait for the checksum launcher to exit');
+ $node->poll_query_until('postgres',
+ "SELECT count(*) = 0 "
+ . "FROM pg_catalog.pg_stat_activity "
+ . "WHERE backend_type = 'datachecksum launcher';");
+
+ test_checksum_state($node, $final);
+
+ $node->stop(stopmode());
+ $node->start;
+
+ test_checksum_state($node, $final);
+
+ # Since the log isn't being written to now, parse the log and check
+ # for instances of checksum verification failures.
+ my $log = PostgreSQL::Test::Utils::slurp_file($node->logfile,
+ $node_loglocation);
+ unlike(
+ $log,
+ qr/page verification failed,.+\d$/,
+ "no checksum validation errors in primary log (during WAL recovery)"
+ );
+ $node_loglocation = -s $node->logfile;
+}
+
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-delay', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-after-xlogctl', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-after-controlfile', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-delay', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-xlogctl', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-controlfile', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-checkpoint', 'on');
+
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-delay', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-checkpoint', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-delay', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-checkpoint', 'off');
+
+$node->stop;
+done_testing();
diff --git a/src/test/modules/test_checksums/t/012_injection_checkpoint_crash.pl b/src/test/modules/test_checksums/t/012_injection_checkpoint_crash.pl
new file mode 100644
index 00000000000..98e9c805c41
--- /dev/null
+++ b/src/test/modules/test_checksums/t/012_injection_checkpoint_crash.pl
@@ -0,0 +1,214 @@
+
+# Copyright (c) 2026, PostgreSQL Global Development Group
+
+# Test suite for testing enabling data checksums in an online cluster with
+# injection point tests injecting failures into the processing
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+use FindBin;
+use lib $FindBin::RealBin;
+
+use DataChecksums::Utils;
+
+# This test suite is expensive, or very expensive, to execute. There are two
+# PG_TEST_EXTRA options for running it, "checksum" for a pared-down test suite
+# an "checksum_extended" for the full suite. The full suite can run for hours
+# on slow or constrained systems.
+my $extended = undef;
+if ($ENV{PG_TEST_EXTRA})
+{
+ $extended = 1 if ($ENV{PG_TEST_EXTRA} =~ /\bchecksum_extended\b/);
+ plan skip_all => 'Expensive data checksums test disabled'
+ unless ($ENV{PG_TEST_EXTRA} =~ /\bchecksum(_extended)?\b/);
+}
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+ plan skip_all => 'Injection points not supported by this build';
+}
+
+# ---------------------------------------------------------------------------
+# Test cluster setup
+#
+
+# Initiate testcluster
+my $node = PostgreSQL::Test::Cluster->new('injection_node');
+$node->init(no_data_checksums => 1);
+$node->start;
+
+# Set up test environment
+$node->safe_psql('postgres', 'CREATE EXTENSION test_checksums;');
+$node->safe_psql('postgres', 'CREATE EXTENSION injection_points;');
+
+my $pgbench = undef;
+my $scalefactor = ($extended ? 10 : 1);
+my $node_loglocation = 0;
+
+$node->command_ok(
+ [
+ 'pgbench', '-p', $node->port, '-i',
+ '-s', $scalefactor, '-q', 'postgres'
+ ]);
+
+# Start a pgbench run in the background against the server specified via the
+# port passed as parameter.
+sub background_rw_pgbench
+{
+ my $port = shift;
+
+ # If a previous pgbench is still running, start by shutting it down.
+ $pgbench->finish if $pgbench;
+
+ my $clients = 1;
+ my $runtime = 2;
+
+ if ($extended)
+ {
+ # Randomize the number of pgbench clients a bit (range 1-16)
+ $clients = 1 + int(rand(15));
+ $runtime = 600;
+ }
+ my @cmd = ('pgbench', '-p', $port, '-T', $runtime, '-c', $clients);
+
+ # Randomize whether we spawn connections or not
+ push(@cmd, '-C') if ($extended && cointoss);
+ # Finally add the database name to use
+ push(@cmd, 'postgres');
+
+ $pgbench = IPC::Run::start(
+ \@cmd,
+ '<' => '/dev/null',
+ '>' => '/dev/null',
+ '2>' => '/dev/null',
+ IPC::Run::timer($PostgreSQL::Test::Utils::timeout_default));
+}
+
+# Test checksum transition concurrent with a checkpoint.
+#
+# The function has these arguments:
+#
+# - start checksum state (enabled/disabled)
+# - change - checksum change to initiate
+# - point1 - injection point before checkpoint
+# - point2 - injection point after checkpoint
+# - final - expected checksum state at the end
+#
+# The test puts the instance into the initial checksum state, triggers a
+# checksum change that pauses on a selected injection point. Then performs
+# a checkpoint, unpauses the change so that it proceeds to a second
+# injection point.
+#
+# Then the instance is restarted in immediate mode to simulate failure,
+# and the final checksum state is validated against the expected value.
+# The server log is checked for checksum failures.
+sub test_checksum_transition
+{
+ my ($start, $change, $point1, $point2, $final) = @_;
+
+ # Start the test suite with pgbench running.
+ background_rw_pgbench($node->port);
+
+ $node->safe_psql('postgres',
+ "SELECT '========== " . $start . " / " . $change . " / " . $point1 . " / " . $final . " =========='");
+
+ note($start . " / " . $change . " / " . $point1 . " / " . $final);
+
+ note('changing checksums into initial state: ' . $start);
+
+ enable_data_checksums($node, wait => 'on') if ($start eq 'enabled');
+ disable_data_checksums($node, wait => 'off') if ($start eq 'disabled');
+
+ note('attaching injection point: ' . $point1);
+ $node->safe_psql('postgres',
+ "SELECT injection_points_attach('" . $point1 . "','wait');"
+ );
+
+ if (defined($point2))
+ {
+ note('attaching injection point: ' . $point2);
+ $node->safe_psql('postgres',
+ "SELECT injection_points_attach('" . $point2 . "','wait');"
+ );
+ }
+
+ note("triggering checksum change: " . $change);
+
+ enable_data_checksums($node) if ($change eq 'enable');
+ disable_data_checksums($node) if ($change eq 'disable');
+
+ note("waiting for the injection point to be hit");
+ $node->poll_query_until(
+ 'postgres',
+ "SELECT COUNT(*) FROM pg_catalog.pg_stat_activity WHERE wait_event = '" . $point1 . "'",
+ '1');
+
+ note('checkpoint');
+ $node->safe_psql('postgres', "CHECKPOINT");
+
+ note("waking and detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_wakeup('" . $point1 . "');");
+
+ note("detaching injection point");
+ $node->safe_psql('postgres',
+ "SELECT injection_points_detach('" . $point1 . "');");
+
+ if (defined($point2))
+ {
+ note("waiting for the injection point to be hit");
+ $node->poll_query_until(
+ 'postgres',
+ "SELECT COUNT(*) FROM pg_catalog.pg_stat_activity WHERE wait_event = '" . $point2 . "'",
+ '1');
+ }
+ else
+ {
+ note('wait for the checksum launcher to exit');
+ $node->poll_query_until('postgres',
+ "SELECT count(*) = 0 "
+ . "FROM pg_catalog.pg_stat_activity "
+ . "WHERE backend_type = 'datachecksum launcher';");
+ }
+
+ $node->stop('immediate');
+ $node->start;
+
+ test_checksum_state($node, $final);
+
+ # Since the log isn't being written to now, parse the log and check
+ # for instances of checksum verification failures.
+ my $log = PostgreSQL::Test::Utils::slurp_file($node->logfile,
+ $node_loglocation);
+ unlike(
+ $log,
+ qr/page verification failed,.+\d$/,
+ "no checksum validation errors in primary log (during WAL recovery)"
+ );
+ $node_loglocation = -s $node->logfile;
+}
+
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-delay', 'datachecksums-enable-inprogress-checksums-after-xlogctl', 'off');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-after-xlogctl', 'datachecksums-enable-inprogress-checksums-after-controlfile', 'off');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-inprogress-checksums-after-controlfile', 'datachecksums-enable-checksums-delay', 'off');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-delay', 'datachecksums-enable-checksums-after-xlogctl', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-xlogctl', 'datachecksums-enable-checksums-after-controlfile', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-controlfile', 'datachecksums-enable-checksums-after-checkpoint', 'on');
+test_checksum_transition('disabled', 'enable', 'datachecksums-enable-checksums-after-checkpoint', undef, 'on');
+
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-delay', 'datachecksums-disable-inprogress-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-xlogctl', 'datachecksums-disable-inprogress-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-controlfile', 'datachecksums-disable-inprogress-checksums-after-checkpoint', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-inprogress-checksums-after-checkpoint', 'datachecksums-disable-checksums-delay', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-delay', 'datachecksums-disable-checksums-after-xlogctl', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-xlogctl', 'datachecksums-disable-checksums-after-controlfile', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-controlfile', 'datachecksums-disable-checksums-after-checkpoint', 'off');
+test_checksum_transition('enabled', 'disable', 'datachecksums-disable-checksums-after-checkpoint', undef, 'off');
+
+$node->stop;
+done_testing();