From 7958ec4b13e9dc581f69df65933789274de499b4 Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryzbyj@telsasoft.com>
Date: Wed, 6 Jul 2022 08:55:11 -0500
Subject: [PATCH v2] wip: initdb should advance the OID counter to FirstNormal

Otherwise, a cluster started in single-user mode immediately after
initdb can create objects in the range of system OIDs, and pg_upgrade
might be able to be run twice (if the cluster has no relations/objects).
---
 src/backend/access/transam/varsup.c |  5 ++---
 src/bin/initdb/initdb.c             |  9 +++++++++
 src/bin/pg_upgrade/check.c          |  5 +++++
 src/bin/pg_upgrade/pg_upgrade.c     | 13 -------------
 4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 849a7ce9d6d..d93974fcaa5 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -543,8 +543,7 @@ GetNewObjectId(void)
 	 *
 	 * During initdb, we start the OID generator at FirstGenbkiObjectId, so we
 	 * only wrap if before that point when in bootstrap or standalone mode.
-	 * The first time through this routine after normal postmaster start, the
-	 * counter will be forced up to FirstNormalObjectId.  This mechanism
+	 * This mechanism
 	 * leaves the OIDs between FirstGenbkiObjectId and FirstNormalObjectId
 	 * available for automatic assignment during initdb, while ensuring they
 	 * will never conflict with user-assigned OIDs.
@@ -553,7 +552,7 @@ GetNewObjectId(void)
 	{
 		if (IsPostmasterEnvironment)
 		{
-			/* wraparound, or first post-initdb assignment, in normal mode */
+			/* wraparound */
 			ShmemVariableCache->nextOid = FirstNormalObjectId;
 			ShmemVariableCache->oidCount = 0;
 		}
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index e00837ecacf..1aad2b335b8 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -61,6 +61,7 @@
 #include "sys/mman.h"
 #endif
 
+#include "access/transam.h"
 #include "access/xlog_internal.h"
 #include "catalog/pg_authid_d.h"
 #include "catalog/pg_class_d.h" /* pgrminclude ignore */
@@ -2735,6 +2736,14 @@ initialize_data_directory(void)
 
 	PG_CMD_CLOSE;
 
+	/* Set FirstNormal OID */
+	snprintf(cmd, sizeof(cmd),
+			 "\"%s/pg_resetwal\" -o %u %s",
+			 bin_path, FirstNormalObjectId, pg_data);
+
+	PG_CMD_OPEN;
+	PG_CMD_CLOSE;
+
 	check_ok();
 }
 
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index f4969bcdad7..f7ff9b5f65b 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -9,6 +9,7 @@
 
 #include "postgres_fe.h"
 
+#include "access/transam.h"
 #include "catalog/pg_authid_d.h"
 #include "catalog/pg_collation.h"
 #include "fe_utils/string_utils.h"
@@ -434,6 +435,10 @@ check_new_cluster_is_empty(void)
 {
 	int			dbnum;
 
+	if (new_cluster.controldata.chkpnt_nxtoid != FirstNormalObjectId)
+		pg_fatal("New cluster is not pristine: OIDs have been assigned since initdb (%u != %u)\n",
+			new_cluster.controldata.chkpnt_nxtoid, FirstNormalObjectId);
+
 	for (dbnum = 0; dbnum < new_cluster.dbarr.ndbs; dbnum++)
 	{
 		int			relnum;
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 115faa222e3..ea7d93d9cbe 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -172,19 +172,6 @@ main(int argc, char **argv)
 	transfer_all_new_tablespaces(&old_cluster.dbarr, &new_cluster.dbarr,
 								 old_cluster.pgdata, new_cluster.pgdata);
 
-	/*
-	 * Assuming OIDs are only used in system tables, there is no need to
-	 * restore the OID counter because we have not transferred any OIDs from
-	 * the old system, but we do it anyway just in case.  We do it late here
-	 * because there is no need to have the schema load use new oids.
-	 */
-	prep_status("Setting next OID for new cluster");
-	exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-			  "\"%s/pg_resetwal\" -o %u \"%s\"",
-			  new_cluster.bindir, old_cluster.controldata.chkpnt_nxtoid,
-			  new_cluster.pgdata);
-	check_ok();
-
 	if (user_opts.do_sync)
 	{
 		prep_status("Sync data directory to disk");
-- 
2.17.1