From a085a6a77c65e10d7c24d134677cce223e1db94e Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 5 Feb 2010 11:08:02 +0000
Subject: [PATCH] Add a note to the documentation of pg_standby that it's
 important that the postgres process has permissions to delete the trigger
 file, per suggestion by Mason Hale.

Also fix pg_standby to do a more predictable exit(200) instead of the
current exit(-1) when the unlink of the trigger file fails anyway.

This only affects 8.3 branch. Older versions didn't have pg_standby,
and in 8.4 upwards pg_standby is no longer responsible for deleting the
trigger file; it's supposed to be done by recovery_end_command instead.
---
 contrib/pg_standby/pg_standby.c |  5 ++++-
 doc/src/sgml/pgstandby.sgml     | 11 ++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
index 4261490dabc..1d6f972447f 100644
--- a/contrib/pg_standby/pg_standby.c
+++ b/contrib/pg_standby/pg_standby.c
@@ -371,13 +371,16 @@ CheckForExternalTrigger(void)
 		 * recovery completes, we will be asked again for the same file from
 		 * the archive using pg_standby so must remove trigger file so we can
 		 * reload file again and come up correctly.
+		 *
+		 * If it fails, return with an exit code that the server will treat
+		 * as a FATAL error.
 		 */
 		rc = unlink(triggerPath);
 		if (rc != 0)
 		{
 			fprintf(stderr, "\n ERROR: could not remove \"%s\": %s", triggerPath, strerror(errno));
 			fflush(stderr);
-			exit(rc);
+			exit(200);
 		}
 		return true;
 	}
diff --git a/doc/src/sgml/pgstandby.sgml b/doc/src/sgml/pgstandby.sgml
index 87629278141..b52bf27d403 100644
--- a/doc/src/sgml/pgstandby.sgml
+++ b/doc/src/sgml/pgstandby.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/pgstandby.sgml,v 2.4.2.1 2008/05/07 22:06:11 alvherre Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/pgstandby.sgml,v 2.4.2.2 2010/02/05 11:08:02 heikki Exp $ -->
 
 <sect1 id="pgstandby">
  <title>pg_standby</title>
@@ -199,6 +199,15 @@ pg_standby <optional> <replaceable>option</> ... </optional> <replaceable>archiv
     </tbody>
    </tgroup>
   </table>
+  <caution>
+    <para>
+      It is critical the trigger file be created with permissions allowing
+      the postgres process to remove the file. Generally this is best done
+      by creating the file from the postgres user account. Failure to do so
+      will prevent completion of WAL file recovery and the server from
+      coming back online successfully.
+    </para>
+  </caution>
   <note>
    <para>
     <literal>--help</literal> is not supported since