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Merge pull request #6801 from johnlinp/master

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man: explicitly distinguish "implicit dependencies" and "default dependencies"
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Lennart Poettering 2017-09-14 21:41:13 +02:00 committed by GitHub
commit 21f0669163
15 changed files with 353 additions and 207 deletions
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2
man/systemd-gpt-auto-generator.xml
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@ -70,7 +70,7 @@
<citerefentry
project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
the units this generator creates are overridden, but additional
automatic dependencies might be created.</para>
implicit dependencies might be created.</para>
<para>This generator will only look for root partitions on the
same physical disk the EFI System Partition (ESP) is located on.

29
man/systemd.automount.xml
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@ -87,19 +87,30 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>If an automount unit is beneath another mount unit in the
file system hierarchy, both a requirement and an ordering
dependency between both units are created automatically.</para>
<para>The following dependencies are implicitly added:</para>
<para>An implicit <varname>Before=</varname> dependency is created
between an automount unit and the mount unit it activates.</para>
<itemizedlist>
<listitem><para>If an automount unit is beneath another mount unit in the
file system hierarchy, both a requirement and an ordering
dependency between both units are created automatically.</para></listitem>
<para>Automount units acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
<filename>umount.target</filename> in order to be stopped during shutdown, unless
<varname>DefaultDependencies=no</varname> is set in the <literal>[Unit]</literal> section.</para>
<listitem><para>An implicit <varname>Before=</varname> dependency is created
between an automount unit and the mount unit it activates.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Automount units acquire automatic <varname>Before=</varname> and
<varname>Conflicts=</varname> on <filename>umount.target</filename> in order to be stopped during
shutdown.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>

8
man/systemd.device.xml
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@ -92,7 +92,7 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Many unit types automatically acquire dependencies on device
units of devices they require. For example,
@ -103,6 +103,12 @@
block devices.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>There are no default dependencies for device units.</para>
</refsect1>
<refsect1>
<title>The udev Database</title>

35
man/systemd.exec.xml
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@ -81,27 +81,30 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>A few execution parameters result in additional, automatic
dependencies to be added.</para>
<para>A few execution parameters result in additional, automatic dependencies to be added:</para>
<para>Units with <varname>WorkingDirectory=</varname>, <varname>RootDirectory=</varname>, <varname>RootImage=</varname>,
<varname>RuntimeDirectory=</varname>, <varname>StateDirectory=</varname>, <varname>CacheDirectory=</varname>,
<varname>LogsDirectory=</varname> or <varname>ConfigurationDirectory=</varname> set automatically gain dependencies
of type <varname>Requires=</varname> and <varname>After=</varname> on all mount units required to access the specified paths.
This is equivalent to having them listed explicitly in <varname>RequiresMountsFor=</varname>.</para>
<itemizedlist>
<listitem><para>Units with <varname>WorkingDirectory=</varname>, <varname>RootDirectory=</varname>, <varname>RootImage=</varname>,
<varname>RuntimeDirectory=</varname>, <varname>StateDirectory=</varname>, <varname>CacheDirectory=</varname>,
<varname>LogsDirectory=</varname> or <varname>ConfigurationDirectory=</varname> set automatically gain dependencies
of type <varname>Requires=</varname> and <varname>After=</varname> on all mount units required to access the specified paths.
This is equivalent to having them listed explicitly in <varname>RequiresMountsFor=</varname>.</para></listitem>
<para>Similar, units with <varname>PrivateTmp=</varname> enabled automatically get mount unit dependencies for all
mounts required to access <filename>/tmp</filename> and <filename>/var/tmp</filename>. They will also gain an
automatic <varname>After=</varname> dependency on
<citerefentry><refentrytitle>systemd-tmpfiles-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
<listitem><para>Similar, units with <varname>PrivateTmp=</varname> enabled automatically get mount unit dependencies for all
mounts required to access <filename>/tmp</filename> and <filename>/var/tmp</filename>. They will also gain an
automatic <varname>After=</varname> dependency on
<citerefentry><refentrytitle>systemd-tmpfiles-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
<para>Units whose standard output or error output is connected to <option>journal</option>, <option>syslog</option>
or <option>kmsg</option> (or their combinations with console output, see below) automatically acquire dependencies
of type <varname>After=</varname> on <filename>systemd-journald.socket</filename>.</para>
<listitem><para>Units whose standard output or error output is connected to <option>journal</option>, <option>syslog</option>
or <option>kmsg</option> (or their combinations with console output, see below) automatically acquire dependencies
of type <varname>After=</varname> on <filename>systemd-journald.socket</filename>.</para></listitem>
</itemizedlist>
</refsect1>
<!-- We don't have any default dependency here. -->
<refsect1>
<title>Options</title>
@ -615,7 +618,7 @@
<para>If the standard output (or error output, see below) of a unit is connected to the journal, syslog or the
kernel log buffer, the unit will implicitly gain a dependency of type <varname>After=</varname> on
<filename>systemd-journald.socket</filename> (also see the automatic dependencies section above).</para>
<filename>systemd-journald.socket</filename> (also see the "Implicit Dependencies" section above).</para>
<para>This setting defaults to the value set with
<option>DefaultStandardOutput=</option> in

73
man/systemd.mount.xml
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@ -109,40 +109,57 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit 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>The following dependencies are implicitly added:</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>
<itemizedlist>
<listitem><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></listitem>
<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>
<listitem><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></listitem>
<para>For mount units with <varname>DefaultDependencies=yes</varname> in the <literal>[Unit]</literal> section (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
<listitem><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></listitem>
<listitem><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></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>All mount units acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
<filename>umount.target</filename> in order to be stopped during shutdown.</para></listitem>
<listitem><para>Mount units referring to local file systems automatically gain
an <varname>After=</varname> dependency on <filename>local-fs-pre.target</filename>.</para></listitem>
<listitem><para>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.</para></listitem>
</itemizedlist>
<para>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>
string of the unit, which forces systemd to consider the mount unit a network mount.</para>
</refsect1>
<refsect1>

41
man/systemd.path.xml
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@ -82,23 +82,36 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>If a path unit is beneath another mount unit in the file
system hierarchy, both a requirement and an ordering dependency
between both units are created automatically.</para>
<para>The following dependencies are implicitly added:</para>
<para>An implicit <varname>Before=</varname> dependency is added
between a path unit and the unit it is supposed to activate.</para>
<itemizedlist>
<listitem><para>If a path unit is beneath another mount unit in the file
system hierarchy, both a requirement and an ordering dependency
between both units are created automatically.</para></listitem>
<para>Unless <varname>DefaultDependencies=false</varname> in the <literal>[Unit]</literal> section is used, path
units will implicitly have dependencies of type <varname>Before=</varname> on <filename>paths.target</filename>,
dependencies of type <varname>After=</varname> and <varname>Requires=</varname> on
<filename>sysinit.target</filename>, and have dependencies of type <varname>Conflicts=</varname> and
<varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that path units are terminated
cleanly prior to system shutdown. Only path units involved with early boot or late system shutdown should disable
this option.
</para>
<listitem><para>An implicit <varname>Before=</varname> dependency is added
between a path unit and the unit it is supposed to activate.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Path units will automatically have dependencies of type <varname>Before=</varname> on
<filename>paths.target</filename>,
dependencies of type <varname>After=</varname> and <varname>Requires=</varname> on
<filename>sysinit.target</filename>, and have dependencies of type <varname>Conflicts=</varname> and
<varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that path units are terminated
cleanly prior to system shutdown. Only path units involved with early boot or late system shutdown should
disable <varname>DefaultDependencies=</varname> option.</para></listitem>
</itemizedlist>
<para></para>
</refsect1>
<refsect1>

15
man/systemd.resource-control.xml
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@ -93,12 +93,19 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Units with the <varname>Slice=</varname> setting set automatically acquire <varname>Requires=</varname> and
<varname>After=</varname> dependencies on the specified slice unit.</para>
<para>The following dependencies are implicitly added:</para>
<itemizedlist>
<listitem><para>Units with the <varname>Slice=</varname> setting set automatically acquire
<varname>Requires=</varname> and <varname>After=</varname> dependencies on the specified
slice unit.</para></listitem>
</itemizedlist>
</refsect1>
<!-- We don't have any default dependency here. -->
<refsect1>
<title>Unified and Legacy Control Group Hierarchies</title>
@ -578,7 +585,7 @@
<para>Special care should be taken when relying on the default slice assignment in templated service units
that have <varname>DefaultDependencies=no</varname> set, see
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, section
"Automatic Dependencies" for details.</para>
"Default Dependencies" for details.</para>
</listitem>
</varlistentry>

33
man/systemd.scope.xml
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@ -75,22 +75,31 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Unless <varname>DefaultDependencies=false</varname>
is used, scope units will implicitly have dependencies of
type <varname>Conflicts=</varname> and
<varname>Before=</varname> on
<filename>shutdown.target</filename>. These ensure
that scope units are removed prior to system
shutdown. Only scope units involved with early boot or
late system shutdown should disable this option.
</para>
<para>Additional implicit dependencies may be added as result of
<para>Implicit dependencies may be added as result of
resource control parameters as documented in
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless
<varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Scope units will automatically have dependencies of
type <varname>Conflicts=</varname> and
<varname>Before=</varname> on
<filename>shutdown.target</filename>. These ensure
that scope units are removed prior to system
shutdown. Only scope units involved with early boot or
late system shutdown should disable
<varname>DefaultDependencies=</varname> option.</para></listitem>
</itemizedlist>
<para></para>
</refsect1>
<refsect1>

68
man/systemd.service.xml
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@ -89,37 +89,23 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Services with <varname>Type=dbus</varname> set automatically
acquire dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on
<filename>dbus.socket</filename>.</para>
<para>The following dependencies are implicitly added:</para>
<para>Socket activated services are automatically ordered after
their activating <filename>.socket</filename> units via an
automatic <varname>After=</varname> dependency.
Services also pull in all <filename>.socket</filename> units
listed in <varname>Sockets=</varname> via automatic
<varname>Wants=</varname> and <varname>After=</varname> dependencies.</para>
<itemizedlist>
<listitem><para>Services with <varname>Type=dbus</varname> set automatically
acquire dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on
<filename>dbus.socket</filename>.</para></listitem>
<para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> is set to
<option>false</option>, service units will implicitly have dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>After=</varname> on
<filename>basic.target</filename> as well as dependencies of type <varname>Conflicts=</varname> and
<varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that normal service units pull in
basic system initialization, and are terminated cleanly prior to system shutdown. Only services involved with early
boot or late system shutdown should disable this option.</para>
<para>Instanced service units (i.e. service units with an <literal>@</literal> in their name) are assigned by
default a per-template slice unit (see
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>), named after the
template unit, containing all instances of the specific template. This slice is normally stopped at shutdown,
together with all template instances. If that is not desired, set <varname>DefaultDependencies=no</varname> in the
template unit, and either define your own per-template slice unit file that also sets
<varname>DefaultDependencies=no</varname>, or set <varname>Slice=system.slice</varname> (or another suitable slice)
in the template unit. Also see
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
<listitem><para>Socket activated services are automatically ordered after
their activating <filename>.socket</filename> units via an
automatic <varname>After=</varname> dependency.
Services also pull in all <filename>.socket</filename> units
listed in <varname>Sockets=</varname> via automatic
<varname>Wants=</varname> and <varname>After=</varname> dependencies.</para></listitem>
</itemizedlist>
<para>Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
@ -128,6 +114,32 @@
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Service units will have dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>After=</varname> on
<filename>basic.target</filename> as well as dependencies of type <varname>Conflicts=</varname> and
<varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that normal service units pull in
basic system initialization, and are terminated cleanly prior to system shutdown. Only services involved with early
boot or late system shutdown should disable this option.</para></listitem>
<listitem><para>Instanced service units (i.e. service units with an <literal>@</literal> in their name) are assigned by
default a per-template slice unit (see
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>), named after the
template unit, containing all instances of the specific template. This slice is normally stopped at shutdown,
together with all template instances. If that is not desired, set <varname>DefaultDependencies=no</varname> in the
template unit, and either define your own per-template slice unit file that also sets
<varname>DefaultDependencies=no</varname>, or set <varname>Slice=system.slice</varname> (or another suitable slice)
in the template unit. Also see
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Options</title>

30
man/systemd.slice.xml
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@ -103,17 +103,29 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Slice units automatically gain dependencies of type
<varname>After=</varname> and <varname>Requires=</varname> on
their immediate parent slice unit.</para>
<para>The following dependencies are implicitly added:</para>
<para>Unless <varname>DefaultDependencies=false</varname> is used in the <literal>[Unit]</literal> section, slice
units will implicitly have dependencies of type <varname>Conflicts=</varname> and <varname>Before=</varname> on
<filename>shutdown.target</filename>. These ensure that slice units are removed prior to system shutdown. Only
slice units involved with early boot or late system shutdown should disable this option.
</para>
<itemizedlist>
<listitem><para>Slice units automatically gain dependencies of type
<varname>After=</varname> and <varname>Requires=</varname> on
their immediate parent slice unit.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Slice units will automatically have dependencies of type <varname>Conflicts=</varname> and
<varname>Before=</varname> on
<filename>shutdown.target</filename>. These ensure that slice units are removed prior to system shutdown.
Only slice units involved with late system shutdown should disable
<varname>DefaultDependencies=</varname> option.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>

71
man/systemd.socket.xml
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@ -97,16 +97,7 @@
<filename>foo@.service</filename> must exist from which services
are instantiated for each incoming connection.</para>
<para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section is set to
<option>false</option>, socket units will implicitly have dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on <filename>sysinit.target</filename> as well as dependencies of type
<varname>Conflicts=</varname> and <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure
that socket units pull in basic system initialization, and are terminated cleanly prior to system shutdown. Only
sockets involved with early boot or late system shutdown should disable this option.</para>
<para>Socket units will have a <varname>Before=</varname>
dependency on the service which they trigger added implicitly. No
implicit <varname>WantedBy=</varname> or
<para>No implicit <varname>WantedBy=</varname> or
<varname>RequiredBy=</varname> dependency from the socket to the
service is added. This means that the service may be started
without the socket, in which case it must be able to open sockets
@ -130,31 +121,24 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Socket units automatically gain a <varname>Before=</varname>
dependency on the service units they activate.</para>
<para>The following dependencies are implicitly added:</para>
<para>Socket units referring to file system paths (such as AF_UNIX
sockets or FIFOs) implicitly gain <varname>Requires=</varname> and
<varname>After=</varname> dependencies on all mount units
necessary to access those paths.</para>
<itemizedlist>
<listitem><para>Socket units automatically gain a <varname>Before=</varname>
dependency on the service units they activate.</para></listitem>
<para>Socket units using the <varname>BindToDevice=</varname>
setting automatically gain a <varname>BindsTo=</varname> and
<varname>After=</varname> dependency on the device unit
encapsulating the specified network interface.</para>
<listitem><para>Socket units referring to file system paths (such as AF_UNIX
sockets or FIFOs) implicitly gain <varname>Requires=</varname> and
<varname>After=</varname> dependencies on all mount units
necessary to access those paths.</para></listitem>
<para>If <varname>DefaultDependencies=yes</varname> is set (the
default), socket units automatically gain a
<varname>Before=</varname> dependency on
<filename>sockets.target</filename>. They also gain a pair of
<varname>After=</varname> and <varname>Requires=</varname>
dependency on <filename>sysinit.target</filename>, and a pair of
<varname>Before=</varname> and <varname>Conflicts=</varname>
dependencies on <filename>shutdown.target</filename>. These
dependencies ensure that the socket unit is started before normal
services at boot, and is stopped on shutdown.</para>
<listitem><para>Socket units using the <varname>BindToDevice=</varname>
setting automatically gain a <varname>BindsTo=</varname> and
<varname>After=</varname> dependency on the device unit
encapsulating the specified network interface.</para></listitem>
</itemizedlist>
<para>Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
@ -163,6 +147,29 @@
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless
<varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Socket units automatically gain a
<varname>Before=</varname> dependency on
<filename>sockets.target</filename>.</para></listitem>
<listitem><para>Socket units automatically gain a pair of
<varname>After=</varname> and <varname>Requires=</varname>
dependency on <filename>sysinit.target</filename>, and a pair of
<varname>Before=</varname> and <varname>Conflicts=</varname>
dependencies on <filename>shutdown.target</filename>. These
dependencies ensure that the socket unit is started before normal
services at boot, and is stopped on shutdown. Only sockets
involved with early boot or late system shutdown should disable
<varname>DefaultDependencies=</varname> option.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Options</title>
@ -358,7 +365,7 @@
specified network interfaces. This controls the
SO_BINDTODEVICE socket option (see <citerefentry
project='man-pages'><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>
for details). If this option is used, an automatic dependency
for details). If this option is used, an implicit dependency
from this socket unit on the network interface device unit
(<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
is created. Note that setting this parameter might result in

29
man/systemd.swap.xml
View File

@ -87,17 +87,16 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>All swap units automatically get the
<varname>BindsTo=</varname> and <varname>After=</varname>
dependencies on the device units or the mount units of the files
they are activated from.</para>
<para>The following dependencies are implicitly added:</para>
<para>Swap units with <varname>DefaultDependencies=</varname> set to its default <option>yes</option> value in the
<literal>[Unit]</literal> section enabled implicitly acquire a <varname>Conflicts=</varname> and a
<varname>Before=</varname> dependency on <filename>umount.target</filename> so that they are deactivated at
shutdown as well as a <varname>Before=swap.target</varname> dependency.</para>
<itemizedlist>
<listitem><para>All swap units automatically get the
<varname>BindsTo=</varname> and <varname>After=</varname>
dependencies on the device units or the mount units of the files
they are activated from.</para></listitem>
</itemizedlist>
<para>Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
@ -106,6 +105,18 @@
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Swap units automatically acquire a <varname>Conflicts=</varname> and a
<varname>Before=</varname> dependency on <filename>umount.target</filename> so that they are deactivated at
shutdown as well as a <varname>Before=swap.target</varname> dependency.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title><filename>fstab</filename></title>

33
man/systemd.target.xml
View File

@ -80,22 +80,29 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Unless <varname>DefaultDependencies=</varname> is set to
<option>no</option> in either of related units or an explicit ordering
dependency is already defined, target units will implicitly complement all
configured dependencies of type <varname>Wants=</varname> or
<varname>Requires=</varname> with dependencies of type
<varname>After=</varname>. Note that <varname>Wants=</varname> or
<varname>Requires=</varname> must be defined in the target unit itself — if
you for example define <varname>Wants=</varname>some.target in
some.service, the implicit ordering will not be added.</para>
<para>There are no implicit dependencies for target units.</para>
</refsect1>
<para>All target units automatically gain <varname>Conflicts=</varname>
dependency against shutdown.target unless <varname>DefaultDependencies=</varname>
is set to <option>no</option>.</para>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless
<varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Target units will automatically complement all
configured dependencies of type <varname>Wants=</varname> or
<varname>Requires=</varname> with dependencies of type
<varname>After=</varname>. Note that <varname>Wants=</varname> or
<varname>Requires=</varname> must be defined in the target unit itself — if
you for example define <varname>Wants=</varname>some.target in
some.service, the automatic ordering will not be added.</para></listitem>
<listitem><para>Target units automatically gain <varname>Conflicts=</varname>
dependency against <filename>shutdown.target</filename>.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>

38
man/systemd.timer.xml
View File

@ -82,20 +82,34 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Timer units automatically gain a <varname>Before=</varname>
dependency on the service they are supposed to activate.</para>
<para>The following dependencies are implicitly added:</para>
<para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section is set to
<option>false</option>, all timer units will implicitly have dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>Before=</varname>
on <filename>timers.target</filename>, as well as <varname>Conflicts=</varname> and <varname>Before=</varname> on
<filename>shutdown.target</filename> to ensure that they are stopped cleanly prior to system shutdown. Timer units
with at least one <varname>OnCalendar=</varname> directive will have an additional <varname>After=</varname>
dependency on <filename>time-sync.target</filename> to avoid being started before the system clock has been
correctly set. Only timer units involved with early boot or late system shutdown should disable the
<varname>DefaultDependencies=</varname> option.</para>
<itemizedlist>
<listitem><para>Timer units automatically gain a <varname>Before=</varname>
dependency on the service they are supposed to activate.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
<itemizedlist>
<listitem><para>Timer units will automatically have dependencies of type <varname>Requires=</varname> and
<varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>Before=</varname>
on <filename>timers.target</filename>, as well as <varname>Conflicts=</varname> and <varname>Before=</varname> on
<filename>shutdown.target</filename> to ensure that they are stopped cleanly prior to system shutdown. Only timer
units involved with early boot or late system shutdown should disable the
<varname>DefaultDependencies=</varname> option.</para></listitem>
<listitem><para>Timer units
with at least one <varname>OnCalendar=</varname> directive will have an additional <varname>After=</varname>
dependency on <filename>time-sync.target</filename> to avoid being started before the system clock has been
correctly set.</para></listitem>
</itemizedlist>
</refsect1>
<refsect1>

55
man/systemd.unit.xml
View File

@ -209,6 +209,12 @@
<!-- Note that we do not document .include here, as we consider it mostly obsolete, and want
people to use .d/ drop-ins instead. -->
<para>Note that while systemd offers a flexible dependency system
between units it is recommended to use this functionality only
sparingly and instead rely on techniques such as bus-based or
socket-based activation which make dependencies implicit,
resulting in a both simpler and more flexible system.</para>
<para>Some unit names reflect paths existing in the file system
namespace. Example: a device unit
<filename>dev-sda.device</filename> refers to a device with the
@ -262,30 +268,41 @@
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<title>Implicit Dependencies</title>
<para>Note that while systemd offers a flexible dependency system
between units it is recommended to use this functionality only
sparingly and instead rely on techniques such as bus-based or
socket-based activation which make dependencies implicit,
resulting in a both simpler and more flexible system.</para>
<para>A number of unit dependencies are implicitly established,
depending on unit type and unit configuration. These implicit
dependencies can make unit configuration file cleaner. For the
implicit dependencies in each unit type, please refer to
section "Implicit Dependencies" in respective man pages.</para>
<para>A number of unit dependencies are automatically established,
depending on unit configuration. On top of that, for units with
<varname>DefaultDependencies=yes</varname> (the default) a couple
of additional dependencies are added. The precise effect of
<varname>DefaultDependencies=yes</varname> depends on the unit
type (see below).</para>
<para>If <varname>DefaultDependencies=yes</varname> is set, units
that are referenced by other units of type
<filename>.target</filename> via a <varname>Wants=</varname> or
<varname>Requires=</varname> dependency might automatically gain
an <varname>Before=</varname> dependency too. See
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
<para>For example, service units with <varname>Type=dbus</varname>
automatically acquire dependencies of type <varname>Requires=</varname>
and <varname>After=</varname> on <filename>dbus.socket</filename>. See
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details.</para>
</refsect1>
<refsect1>
<title>Default Dependencies</title>
<para>Default dependencies are similar to implicit dependencies,
but can be turned on and off by setting
<varname>DefaultDependencies=</varname> to <varname>yes</varname>
(the default) and <varname>no</varname>, while implicit dependencies
are always in effect. See section "Default Dependencies" in respective
man pages for the effect of enabling
<varname>DefaultDependencies=</varname> in each unit types.</para>
<para>For example, target units will complement all configured
dependencies of type type <varname>Wants=</varname> or
<varname>Requires=</varname> with dependencies of type
<varname>After=</varname>. See
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details. Note that this behavior can be turned off by setting
<varname>DefaultDependencies=no</varname>.</para>
</refsect1>
<refsect1>
<title>Unit File Load Path</title>