From 84d4de97e8d14469974eb488730a13f942aa787a Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Fri, 7 Jun 2019 20:48:39 +0900
Subject: [PATCH] Improve some comments in pg_checksums about the needed clean
shutdown
It was not clear from the code why it is necessary. And we need a clean
shutdown to avoid random checksum failures caused by torn pages.
Author: Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoDum5MbAb7F=pa9dOD1W2tukuDMPzWT7NjZceNoWB_6Qw@mail.gmail.com
---
src/bin/pg_checksums/pg_checksums.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 7c7a75cdcd..b8e7c32dba 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -475,7 +475,7 @@ main(int argc, char *argv[])
exit(1);
}
- /* Check if cluster is running */
+ /* Read the control file and check compatibility */
ControlFile = get_controlfile(DataDir, &crc_ok);
if (!crc_ok)
{
@@ -497,6 +497,11 @@ main(int argc, char *argv[])
exit(1);
}
+ /*
+ * Check if cluster is running. A clean shutdown is required to avoid
+ * random checksum failures caused by torn pages. Note that this doesn't
+ * guard against someone starting the cluster concurrently.
+ */
if (ControlFile->state != DB_SHUTDOWNED &&
ControlFile->state != DB_SHUTDOWNED_IN_RECOVERY)
{
--
2.50.1