Merge pull request #1854 from poettering/unit-deps

Dependency engine improvements

1 files changed, 47 insertions, 5 deletions

diff --git a/man/systemd.mount.xml b/man/systemd.mount.xml
index dd6b7a51a8..67e96dc157 100644
--- a/man/systemd.mount.xml
+++ b/man/systemd.mount.xml
@@ -94,10 +94,6 @@
     unit, to allow on-demand or parallelized mounting. See
     <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 
-    <para>If a mount point is beneath another mount point in the file
-    system hierarchy, a dependency between both units is created
-    automatically.</para>
-
     <para>Mount points created at runtime (independently of unit files
     or <filename>/etc/fstab</filename>) will be monitored by systemd
     and appear like any other mount unit in systemd. See
@@ -114,6 +110,52 @@
   </refsect1>
 
   <refsect1>
+    <title>Automatic Dependencies</title>
+
+    <para>If a mount unit is beneath another mount unit in the file
+    system hierarchy, both a requirement dependency and an ordering
+    dependency between both units are created automatically.</para>
+
+    <para>Block device backed file systems automatically gain
+    <varname>BindsTo=</varname> and <varname>After=</varname> type
+    dependencies on the device unit encapsulating the block
+    device (see below).</para>
+
+    <para>If traditional file system quota is enabled for a mount
+    unit, automatic <varname>Wants=</varname> and
+    <varname>Before=</varname> dependencies on
+    <filename>systemd-quotacheck.service</filename> and
+    <filename>quotaon.service</filename> are added.</para>
+
+    <para>For mount units with
+    <varname>DefaultDependencies=yes</varname> (the default) a couple
+    additional dependencies are added. Mount units referring to local
+    file systems automatically gain an <varname>After=</varname>
+    dependency on <filename>local-fs-pre.target</filename>. Network
+    mount units automatically acquire <varname>After=</varname>
+    dependencies on <filename>remote-fs-pre.target</filename>,
+    <filename>network.target</filename> and
+    <filename>network-online.target</filename>. Towards the latter a
+    <varname>Wants=</varname> unit is added as well. Mount units
+    referring to local and network file systems are distinguished by
+    their file system type specification. In some cases this is not
+    sufficient (for example network block device based mounts, such as
+    iSCSI), in which case <option>_netdev</option> may be added to the
+    mount option string of the unit, which forces systemd to consider the
+    mount unit a network mount. Mount units (regardless if local or
+    network) also acquire automatic <varname>Before=</varname> and
+    <varname>Conflicts=</varname> on
+    <filename>umount.target</filename> in order to be stopped
+    during shutdown.</para>
+
+    <para>Additional implicit dependencies may be added as result of
+    execution and resource control parameters as documented in
+    <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+    and
+    <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+  </refsect1>
+
+  <refsect1>
     <title><filename>fstab</filename></title>
 
     <para>Mount units may either be configured via unit files, or via
@@ -130,7 +172,7 @@
     <para>When reading <filename>/etc/fstab</filename> a few special
     mount options are understood by systemd which influence how
     dependencies are created for mount points. systemd will create a
-    dependency of type <option>Wants</option> or
+    dependency of type <varname>Wants=</varname> or
     <option>Requires</option> (see option <option>nofail</option>
     below), from either <filename>local-fs.target</filename> or
     <filename>remote-fs.target</filename>, depending whether the file