s3:docs: update the idmap_tdb manpage to reflect current facts.

Michael

diff --git a/docs-xml/manpages-3/idmap_tdb.8.xml b/docs-xml/manpages-3/idmap_tdb.8.xml
index 4258d95ac67a0231704c17a2743cda10c61398d8..fb23076d088739e437f0a885b4237b0f3f12692d 100644 (file)
--- a/docs-xml/manpages-3/idmap_tdb.8.xml
+++ b/docs-xml/manpages-3/idmap_tdb.8.xml
@@ -19,9 +19,27 @@
 <refsynopsisdiv>
        <title>DESCRIPTION</title>
 
-       <para>The idmap_tdb plugin is the default backend used by winbindd
-       for storing SID/uid/gid mapping tables and implements
-       both the &quot;idmap&quot; and &quot;idmap alloc&quot; APIs.
+       <para>
+       The idmap_tdb plugin is the default backend used by winbindd
+       for storing SID/uid/gid mapping tables. In contrast to read only
+       backends like idmap_rid, it is an allocating backend:
+       This means that it needs to allocate new user and group IDs
+       to create new mappings as requests to yet unmapped users are answered.
+       </para>
+
+       <para>
+       Note that in order for this (or any other allocating) backend to
+       function at all, the default backend needs to be writeable.
+       The ranges used for uid and gid allocation are the default ranges
+       configured by &quot;idmap uid&quot; and &quot;idmap gid&quot;.
+       </para>
+
+       <para>
+       Furthermore, since there is only one global allocating backend
+       responsible for all domains using writeable idmap backends,
+       any explicitly configured domain with idmap backend tdb
+       should have the same range as the default range, since it needs
+       to use the global uid / gid allocator. See the example below.
        </para>
 </refsynopsisdiv>
 
@@ -33,30 +51,53 @@
                <term>range = low - high</term>
                 <listitem><para>
                        Defines the available matching uid and gid range for which the
-                       backend is authoritative.  Note that the range commonly matches
-                       the allocation range due to the fact that the same backend will
-                       store and retrieve SID/uid/gid mapping entries.  If the parameter
-                       is absent, Winbind fail over to use the &quot;idmap uid&quot; and
-                       &quot;idmap gid&quot; options from smb.conf.
+                       backend is authoritative.
+                       If the parameter is absent, Winbind fails over to use
+                       the &quot;idmap uid&quot; and &quot;idmap gid&quot; options
+                       from smb.conf.
                 </para></listitem>
                 </varlistentry>
        </variablelist>
 </refsect1>
 
 <refsect1>
-       <title>IDMAP ALLOC OPTIONS</title>
+       <title>EXAMPLES</title>
 
-       <variablelist>
-                <varlistentry>
-               <term>range = low - high</term>
-                <listitem><para>
-                       Defines the available matching uid and gid range from which
-                       winbindd can allocate for users and groups.  If the parameter
-                       is absent, Winbind fail over to use the &quot;idmap uid&quot;
-                       and &quot;idmap gid&quot; options from smb.conf.
-                </para></listitem>
-                </varlistentry>
-       </variablelist>
+       <para>
+       This example shows how tdb is used as a the default idmap backend.
+       It configures the idmap range through the global options for all
+       domains encountered. This same range is used for uid/gid allocation.
+       </para>
+
+       <programlisting>
+       [global]
+       # "idmap backend = tdb" is redundant here since it is the default
+       idmap backend = tdb
+       idmap uid = 1000000-2000000
+       idmap gid = 1000000-2000000
+       </programlisting>
+
+       <para>
+       This (rather theoretical) example shows how tdb can be used as the
+       allocating backend while ldap is the default backend used to store
+       the mappings.
+       It adds an explicit configuration for some domain DOM1, that
+       uses the tdb idmap backend. Note that the same range as the
+       default uid/gid range is used, since the allocator has to serve
+       both the default backend and the explicitly configured domain DOM1.
+       </para>
+
+       <programlisting>
+       [global]
+       idmap backend = ldap
+       idmap uid = 1000000-2000000
+       idmap gid = 1000000-2000000
+       # use a different uid/gid allocator:
+       idmap alloc backend = tdb
+
+       idmap config DOM1 : backend = tdb
+       idmap config DOM1 : range = 1000000-2000000
+       </programlisting>
 </refsect1>
 
 <refsect1>