-<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+ SPDX-License-Identifier: LGPL-2.1+
+ Copyright © 2014 Jason St. John
+-->
+
<refentry id="udev">
<refentryinfo>
<title>udev</title>
<productname>systemd</productname>
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Greg</firstname>
- <surname>Kroah-Hartmann</surname>
- <email>greg@kroah.com</email>
- </author>
- <author>
- <contrib>Developer</contrib>
- <firstname>Kay</firstname>
- <surname>Sievers</surname>
- <email>kay@vrfy.org</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
</refsect1>
<refsect1><title>Rules Files</title>
- <para>The udev rules are read from the files located in the
- system rules directory <filename>/usr/lib/udev/rules.d</filename>,
- the volatile runtime directory <filename>/run/udev/rules.d</filename>
- and the local administration directory <filename>/etc/udev/rules.d</filename>.
- All rules files are collectively sorted and processed in lexical order,
- regardless of the directories in which they live. However, files with
- identical filenames replace each other. Files in <filename>/etc</filename>
- have the highest priority, files in <filename>/run</filename> take precedence
- over files with the same name in <filename>/usr/lib</filename>. This can be
- used to override a system-supplied rules file with a local file if needed;
- a symlink in <filename>/etc</filename> with the same name as a rules file in
- <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>,
- disables the rules file entirely. Rule files must have the extension
- <filename>.rules</filename>; other extensions are ignored.</para>
+ <para>The udev rules are read from the files located in the system rules directories
+ <filename>/usr/lib/udev/rules.d</filename> and <filename>/usr/local/lib/udev/rules.d</filename>, the
+ volatile runtime directory <filename>/run/udev/rules.d</filename> and the local administration
+ directory <filename>/etc/udev/rules.d</filename>. All rules files are collectively sorted and
+ processed in lexical order, regardless of the directories in which they live. However, files with
+ identical filenames replace each other. Files in <filename>/etc</filename> have the highest priority,
+ files in <filename>/run</filename> take precedence over files with the same name under
+ <filename>/usr</filename>. This can be used to override a system-supplied rules file with a local
+ file if needed; a symlink in <filename>/etc</filename> with the same name as a rules file in
+ <filename>/usr/lib</filename>, pointing to <filename>/dev/null</filename>, disables the rules file
+ entirely. Rule files must have the extension <filename>.rules</filename>; other extensions are
+ ignored.</para>
<para>Every line in the rules file contains at least one key-value pair.
Except for empty lines or lines beginning with <literal>#</literal>, which are ignored.
value itself contains trailing whitespace.
</para>
</listitem>
+ </varlistentry>
+ <varlistentry>
<term><varname>SYSCTL{<replaceable>kernel parameter</replaceable>}</varname></term>
<listitem>
<para>Match a kernel parameter value.
<para>Starting daemons or other long-running processes is not appropriate
for udev; the forked processes, detached or not, will be unconditionally
killed after the event handling has finished.</para>
+ <para>Note that running programs that access the network or mount/unmount
+ filesystems is not allowed inside of udev rules, due to the default sandbox
+ that is enforced on <filename>systemd-udevd.service</filename>.</para>
+ <para>Please also note that <literal>:=</literal> and <literal>=</literal> are clearing
+ both, program and builtin commands.</para>
</listitem>
</varlistentry>
<para>Disable the watching of a device node with inotify.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>db_persist</option></term>
+ <listitem>
+ <para>Set the flag (sticky bit) on the udev database entry
+ of the event device. Device properties are then kept in the
+ database even when
+ <command>udevadm info --cleanup-db</command> is called.
+ This option can be useful in certain cases
+ (e.g. Device Mapper devices) for persisting device state
+ on the transition from initramfs.</para>
+ </listitem>
+ </varlistentry>
</variablelist>
</listitem>
</varlistentry>
<para>The <varname>NAME</varname>, <varname>SYMLINK</varname>,
<varname>PROGRAM</varname>, <varname>OWNER</varname>,
- <varname>GROUP</varname>, <varname>MODE</varname>, and
- <varname>RUN</varname> fields support simple string substitutions.
+ <varname>GROUP</varname>, <varname>MODE</varname>, <varname>SECLABEL</varname>,
+ and <varname>RUN</varname> fields support simple string substitutions.
The <varname>RUN</varname> substitutions are performed after all rules
have been processed, right before the program is executed, allowing for
the use of device properties set by earlier matching rules. For all other
projects / thirdparty / systemd.git / blobdiff