pg_upgrade: set vacuum_defer_cleanup_age to zero

Non-zero vacuum_defer_cleanup_age values cause pg_upgrade freezing of
the system catalogs to be incomplete, or do nothing.  This will cause
the upgrade to fail in confusing ways.

Reported-by: Laurenz Albe

Discussion: https://postgr.es/m/7d6f6c22ba05ce0c526e9e8b7bfa8105e7da45e6.camel@cybertec.at

Backpatch-through: 9.5

Author: bmomjian

src/bin/pg_upgrade/server.c

@@ -239,6 +239,9 @@ start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
 	 * we only modify the new cluster, so only use it there.  If there is a
 	 * crash, the new cluster has to be recreated anyway.  fsync=off is a big
 	 * win on ext4.
+	 *
+	 * Force vacuum_defer_cleanup_age to 0 on the new cluster, so that
+	 * vacuumdb --freeze actually freezes the tuples.
 	 */
 	snprintf(cmd, sizeof(cmd),
 			 "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" -o \"-p %d%s%s %s%s\" start",
@@ -247,7 +250,7 @@ start_postmaster(ClusterInfo *cluster, bool report_and_exit_on_error)
 			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? " -b" :
 			 " -c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
 			 (cluster == &new_cluster) ?
-			 " -c synchronous_commit=off -c fsync=off -c full_page_writes=off" : "",
+			 " -c synchronous_commit=off -c fsync=off -c full_page_writes=off -c vacuum_defer_cleanup_age=0" : "",
 			 cluster->pgopts ? cluster->pgopts : "", socket_string);
 
 	/*