doc: Improve description of pg_ctl -l log file permissions

The documentation stated only that the log file created by pg_ctl -l is
inaccessible to other users by default. However, since commit c37b3d0,
the actual behavior is that only the cluster owner has access by default,
but users in the same group as the cluster owner may also read the file
if group access is enabled in the cluster.

This commit updates the documentation to describe this behavior
more clearly.

Backpatch to all supported versions.

Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Reviewed-by: Xiaopeng Wang <wxp_728@163.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/OS9PR01MB1214959BE987B4839E3046050F54BA@OS9PR01MB12149.jpnprd01.prod.outlook.com
Backpatch-through: 14

diff --git a/doc/src/sgml/ref/pg_ctl-ref.sgml b/doc/src/sgml/ref/pg_ctl-ref.sgml
index 2864e8239b1a9abfe01e30b78bf3b95a966c3155..bdd988bbc620419652ec0500f6f418d9581cb12e 100644 (file)
--- a/doc/src/sgml/ref/pg_ctl-ref.sgml
+++ b/doc/src/sgml/ref/pg_ctl-ref.sgml
@@ -299,8 +299,9 @@ PostgreSQL documentation
        <para>
         Append the server log output to
         <replaceable>filename</replaceable>.  If the file does not
-        exist, it is created.  The <systemitem>umask</systemitem> is set to 077,
-        so access to the log file is disallowed to other users by default.
+        exist, it is created.  By default, only the cluster owner can
+        access the log file.  If group access is enabled in the cluster,
+        users in the same group as the cluster owner can also read it.
        </para>
       </listitem>
      </varlistentry>