pg_upgrade: issue helpful error message for use on standbys

Commit 777e6ddf1723306bd2bf8fe6f804863f459b0323 checked for a shut down
message from a standby and allowed it to continue.  This patch reports a
helpful error message in these cases, suggesting to use rsync as
documented.

Diagnosed-by: Martín Marqués
Discussion: https://postgr.es/m/CAPdiE1xYCow-reLjrhJ9DqrMu-ppNq0ChUUEvVdxhdjGRD5_eA@mail.gmail.com

Backpatch-through: 9.3

diff --git a/src/bin/pg_upgrade/controldata.c b/src/bin/pg_upgrade/controldata.c
index f2f3ac55e78e1c6a8f835c9179bd2440435baa41..c2962043c23d85618622412e999bd07bc8785f6d 100644 (file)
--- a/src/bin/pg_upgrade/controldata.c
+++ b/src/bin/pg_upgrade/controldata.c
@@ -150,8 +150,14 @@ get_control_data(ClusterInfo *cluster, bool live_check)
                                /* remove leading spaces */
                                while (*p == ' ')
                                        p++;
-                               if (strcmp(p, "shut down\n") != 0 &&
-                                       strcmp(p, "shut down in recovery\n") != 0)
+                               if (strcmp(p, "shut down in recovery\n") == 0)
+                               {
+                                       if (cluster == &old_cluster)
+                                               pg_fatal("The source cluster was shut down while in recovery mode.  To upgrade, use \"rsync\" as documented or shut it down as a primary.\n");
+                                       else
+                                               pg_fatal("The target cluster was shut down while in recovery mode.  To upgrade, use \"rsync\" as documented or shut it down as a primary.\n");
+                               }
+                               else if (strcmp(p, "shut down\n") != 0)
                                {
                                        if (cluster == &old_cluster)
                                                pg_fatal("The source cluster was not shut down cleanly.\n");