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 a0287bb81d6234d00ac1a4c5b4978c732b289cf7..b762b002c02bb5293df6e0d18bd9544e7769c497 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>