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diff --git a/man/udevadm.xml b/man/udevadm.xml new file mode 100644 index 0000000..ee0658d --- /dev/null +++ b/man/udevadm.xml @@ -0,0 +1,931 @@ +<?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-or-later --> + +<refentry id="udevadm" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>udevadm</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>udevadm</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>udevadm</refname><refpurpose>udev management tool</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>udevadm</command> + <arg><option>--debug</option></arg> + <arg><option>--version</option></arg> + <arg><option>--help</option></arg> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm info <optional>options</optional> <optional>devpath</optional></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm settle <optional>options</optional></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm control <replaceable>option</replaceable></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm monitor <optional>options</optional></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm wait <optional>options</optional> <replaceable>device|syspath</replaceable></command> + </cmdsynopsis> + <cmdsynopsis> + <command>udevadm lock <optional>options</optional> <replaceable>command</replaceable></command> + </cmdsynopsis> + </refsynopsisdiv> + + <refsect1><title>Description</title> + <para><command>udevadm</command> expects a command and command + specific options. It controls the runtime behavior of + <command>systemd-udevd</command>, requests kernel events, manages + the event queue, and provides simple debugging mechanisms.</para> + </refsect1> + + <refsect1><title>Options</title> + <variablelist> + <varlistentry> + <term><option>-d</option></term> + <term><option>--debug</option></term> + <listitem> + <para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and + <command>udevadm test-builtin</command> commands.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + + <refsect2><title>udevadm info + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg> + </title> + + <para>Query the udev database for device information.</para> + + <para>Positional arguments should be used to specify one or more devices. Each one may be a device name + (in which case it must start with <filename>/dev/</filename>), a sys path (in which case it must start + with <filename>/sys/</filename>), or a systemd device unit name (in which case it must end with + <literal>.device</literal>, see + <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>). + </para> + + <variablelist> + <varlistentry> + <term><option>-q</option></term> + <term><option>--query=<replaceable>TYPE</replaceable></option></term> + <listitem> + <para>Query the database for the specified type of device data. + Valid <replaceable>TYPE</replaceable>s are: + <constant>name</constant>, <constant>symlink</constant>, + <constant>path</constant>, <constant>property</constant>, + <constant>all</constant>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>--property=<replaceable>NAME</replaceable></option></term> + <listitem> + <para>When showing device properties using the <option>--query=property</option> + option, limit display to properties specified in the argument. The argument should + be a comma-separated list of property names. If not specified, all known properties + are shown.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--value</option></term> + <listitem> + <para>When showing device properties using the <option>--query=property</option> + option, print only their values, and skip the property name and <literal>=</literal>.</para> + <para>Cannot be used together with <option>-x/--export</option> or + <option>-P/--export-prefix</option>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-p</option></term> + <term><option>--path=<replaceable>DEVPATH</replaceable></option></term> + <listitem> + <para>The <filename>/sys/</filename> path of the device to query, e.g. + <filename><optional>/sys/</optional>/class/block/sda</filename>. This option is an alternative to + the positional argument with a <filename>/sys/</filename> prefix. <command>udevadm info + --path=/class/block/sda</command> is equivalent to <command>udevadm info + /sys/class/block/sda</command>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-n</option></term> + <term><option>--name=<replaceable>FILE</replaceable></option></term> + <listitem> + <para>The name of the device node or a symlink to query, + e.g. <filename><optional>/dev/</optional>/sda</filename>. This option is an alternative to the + positional argument with a <filename>/dev/</filename> prefix. <command>udevadm info + --name=sda</command> is equivalent to <command>udevadm info /dev/sda</command>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-r</option></term> + <term><option>--root</option></term> + <listitem> + <para>Print absolute paths in <command>name</command> or <command>symlink</command> + query.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-a</option></term> + <term><option>--attribute-walk</option></term> + <listitem> + <para>Print all sysfs properties of the specified device that can be used + in udev rules to match the specified device. It prints all devices + along the chain, up to the root of sysfs that can be used in udev rules.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-t</option></term> + <term><option>--tree</option></term> + <listitem> + <para>Display a sysfs tree. This recursively iterates through the sysfs hierarchy and displays it + in a tree structure. If a path is specified only the subtree below and its parent directories are + shown. This will show both device and subsystem items.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-x</option></term> + <term><option>--export</option></term> + <listitem> + <para>Print output as key/value pairs. Values are enclosed in single quotes. + This takes effects only when <option>--query=property</option> or + <option>--device-id-of-file=<replaceable>FILE</replaceable></option> is specified.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-P</option></term> + <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term> + <listitem> + <para>Add a prefix to the key name of exported values. + This implies <option>--export</option>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-d</option></term> + <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term> + <listitem> + <para>Print major/minor numbers of the underlying device, where the file lives on. + If this is specified, all positional arguments are ignored.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-e</option></term> + <term><option>--export-db</option></term> + <listitem> + <para>Export the content of the udev database.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-c</option></term> + <term><option>--cleanup-db</option></term> + <listitem> + <para>Cleanup the udev database.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-w<optional>SECONDS</optional></option></term> + <term><option>--wait-for-initialization<optional>=SECONDS</optional></option></term> + <listitem> + <para>Wait for device to be initialized. If argument <replaceable>SECONDS</replaceable> + is not specified, the default is to wait forever.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="no-pager" /> + </variablelist> + + <para>The generated output shows the current device database entry in a terse format. Each line shown + is prefixed with one of the following characters:</para> + + <table> + <title><command>udevadm info</command> output prefixes</title> + <tgroup cols='2' align='left' colsep='1' rowsep='1'> + <colspec colname="prefix" /> + <colspec colname="meaning" /> + <thead> + <row> + <entry>Prefix</entry> + <entry>Meaning</entry> + </row> + </thead> + <tbody> + <row> + <entry><literal>P:</literal></entry> + <entry>Device path in <filename>/sys/</filename></entry> + </row> + <row> + <entry><literal>M:</literal></entry> + <entry>Device name in <filename>/sys/</filename> (i.e. the last component of <literal>P:</literal>)</entry> + </row> + <row> + <entry><literal>R:</literal></entry> + <entry>Device number in <filename>/sys/</filename> (i.e. the numeric suffix of the last component of <literal>P:</literal>)</entry> + </row> + <row> + <entry><literal>U:</literal></entry> + <entry>Kernel subsystem</entry> + </row> + <row> + <entry><literal>T:</literal></entry> + <entry>Kernel device type within subsystem</entry> + </row> + <row> + <entry><literal>D:</literal></entry> + <entry>Kernel device node major/minor</entry> + </row> + <row> + <entry><literal>I:</literal></entry> + <entry>Network interface index</entry> + </row> + <row> + <entry><literal>N:</literal></entry> + <entry>Kernel device node name</entry> + </row> + <row> + <entry><literal>L:</literal></entry> + <entry>Device node symlink priority</entry> + </row> + <row> + <entry><literal>S:</literal></entry> + <entry>Device node symlink</entry> + </row> + <row> + <entry><literal>Q:</literal></entry> + <entry>Block device sequence number (DISKSEQ)</entry> + </row> + <row> + <entry><literal>V:</literal></entry> + <entry>Attached driver</entry> + </row> + <row> + <entry><literal>E:</literal></entry> + <entry>Device property</entry> + </row> + </tbody> + </tgroup> + </table> + </refsect2> + + <refsect2><title>udevadm trigger + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg> + </title> + <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para> + + <para>Takes device specifications as positional arguments. See the description of <command>info</command> + above.</para> + + <variablelist> + <varlistentry> + <term><option>-v</option></term> + <term><option>--verbose</option></term> + <listitem> + <para>Print the list of devices which will be triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-n</option></term> + <term><option>--dry-run</option></term> + <listitem> + <para>Do not actually trigger the event.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-q</option></term> + <term><option>--quiet</option></term> + <listitem> + <para>Suppress error logging in triggering events.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-t</option></term> + <term><option>--type=<replaceable>TYPE</replaceable></option></term> + <listitem> + <para>Trigger a specific type of devices. Valid types are <literal>all</literal>, + <literal>devices</literal>, and <literal>subsystems</literal>. The default value is + <literal>devices</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-c</option></term> + <term><option>--action=<replaceable>ACTION</replaceable></option></term> + <listitem> + <para>Type of event to be triggered. Possible actions are <literal>add</literal>, + <literal>remove</literal>, <literal>change</literal>, <literal>move</literal>, + <literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>, + and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used + to list the possible actions. The default value is <literal>change</literal>. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--prioritized-subsystem=<replaceable>SUBSYSTEM<optional>,<replaceable>SUBSYSTEM</replaceable>…</optional></replaceable></option></term> + <listitem> + <para>Takes a comma separated list of subsystems. When triggering events for devices, the + devices from the specified subsystems and their parents are triggered first. For example, + if <option>--prioritized-subsystem=block,net</option>, then firstly all block devices and + their parents are triggered, in the next all network devices and their parents are + triggered, and lastly the other devices are triggered. This option can be specified + multiple times, and in that case the lists of the subsystems will be merged. That is, + <option>--prioritized-subsystem=block --prioritized-subsystem=net</option> is equivalent to + <option>--prioritized-subsystem=block,net</option>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-s</option></term> + <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term> + <listitem> + <para>Trigger events for devices which belong to a + matching subsystem. This option supports shell style pattern matching. + When this option is specified more than once, then each matching result is ORed, that is, + all the devices in each subsystem are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-S</option></term> + <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term> + <listitem> + <para>Do not trigger events for devices which belong to a matching subsystem. This option + supports shell style pattern matching. When this option is specified more than once, + then each matching result is ANDed, that is, devices which do not match all specified + subsystems are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-a</option></term> + <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term> + <listitem> + <para>Trigger events for devices with a matching sysfs attribute. If a value is specified along + with the attribute name, the content of the attribute is matched against the given value using + shell style pattern matching. If no value is specified, the existence of the sysfs attribute is + checked. When this option is specified multiple times, then each matching result is ANDed, + that is, only devices which have all specified attributes are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-A</option></term> + <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term> + <listitem> + <para>Do not trigger events for devices with a matching sysfs attribute. If a value is specified + along with the attribute name, the content of the attribute is matched against the given value + using shell style pattern matching. If no value is specified, the existence of the sysfs attribute + is checked. When this option is specified multiple times, then each matching result is ANDed, + that is, only devices which have none of the specified attributes are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-p</option></term> + <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term> + <listitem> + <para>Trigger events for devices with a matching property value. This option supports shell style + pattern matching. When this option is specified more than once, then each matching result is ORed, + that is, devices which have one of the specified properties are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-g</option></term> + <term><option>--tag-match=<replaceable>TAG</replaceable></option></term> + <listitem> + <para>Trigger events for devices with a matching tag. When this option is specified multiple times, + then each matching result is ANDed, that is, devices which have all specified tags are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-y</option></term> + <term><option>--sysname-match=<replaceable>NAME</replaceable></option></term> + <listitem> + <para>Trigger events for devices for which the last component (i.e. the filename) of the + <filename>/sys/</filename> path matches the specified <replaceable>PATH</replaceable>. This option + supports shell style pattern matching. When this option is specified more than once, then each + matching result is ORed, that is, all devices which have any of the specified + <replaceable>NAME</replaceable> are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--name-match=<replaceable>NAME</replaceable></option></term> + <listitem> + <para>Trigger events for devices with a matching device path. When this option is specified more than once, + then each matching result is ORed, that is, all specified devices are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-b</option></term> + <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term> + <listitem> + <para>Trigger events for all children of a given device. When this option is specified more than once, + then each matching result is ORed, that is, all children of each specified device are triggered.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--initialized-match</option></term> + <term><option>--initialized-nomatch</option></term> + <listitem> + <para>When <option>--initialized-match</option> is specified, trigger events for devices + that are already initialized by <command>systemd-udevd</command>, and skip devices that + are not initialized yet.</para> + <para>When <option>--initialized-nomatch</option> is specified, trigger events for devices + that are not initialized by <command>systemd-udevd</command> yet, and skip devices that + are already initialized.</para> + <para>Typically, it is essential that applications which intend to use such a match, make + sure a suitable udev rule is installed that sets at least one property on devices that + shall be matched. See also Initialized Devices section below for more details.</para> + <para>WARNING: <option>--initialized-nomatch</option> can potentially save a significant + amount of time compared to re-triggering all devices in the system and e.g. can be used to + optimize boot time. However, this is not safe to be used in a boot sequence in general. + Especially, when udev rules for a device depend on its parent devices (e.g. + <literal>ATTRS</literal> or <literal>IMPORT{parent}</literal> keys, see + <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for more details), the final state of the device becomes easily unstable with this option. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-w</option></term> + <term><option>--settle</option></term> + <listitem> + <para>Apart from triggering events, also waits for those events to + finish. Note that this is different from calling <command>udevadm + settle</command>. <command>udevadm settle</command> waits for all + events to finish. This option only waits for events triggered by + the same command to finish.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--uuid</option></term> + <listitem> + <para>Trigger the synthetic device events, and associate a randomized UUID with each. These UUIDs + are printed to standard output, one line for each event. These UUIDs are included in the uevent + environment block (in the <literal>SYNTH_UUID=</literal> property) and may be used to track + delivery of the generated events.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--wait-daemon[=<replaceable>SECONDS</replaceable>]</option></term> + <listitem> + <para>Before triggering uevents, wait for systemd-udevd daemon to be initialized. + Optionally takes timeout value. Default timeout is 5 seconds. This is equivalent to invoke + invoking <command>udevadm control --ping</command> before <command>udevadm trigger</command>.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + + <para>In addition, optional positional arguments can be used + to specify device names or sys paths. They must start with + <filename>/dev/</filename> or <filename>/sys/</filename> + respectively.</para> + </refsect2> + + <refsect2><title>udevadm settle + <arg choice="opt"><replaceable>options</replaceable></arg> + </title> + <para>Watches the udev event queue, and exits if all current events are handled.</para> + <variablelist> + <varlistentry> + <term><option>-t</option></term> + <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term> + <listitem> + <para>Maximum number of seconds to wait for the event + queue to become empty. The default value is 120 seconds. A + value of 0 will check if the queue is empty and always + return immediately. A non-zero value will return an exit + code of 0 if queue became empty before timeout was reached, + non-zero otherwise.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-E</option></term> + <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term> + <listitem> + <para>Stop waiting if file exists.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + + <para>See + <citerefentry><refentrytitle>systemd-udev-settle.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for more information.</para> + </refsect2> + + <refsect2><title>udevadm control <replaceable>option</replaceable></title> + <para>Modify the internal state of the running udev daemon.</para> + <variablelist> + <varlistentry> + <term><option>-e</option></term> + <term><option>--exit</option></term> + <listitem> + <para>Signal and wait for systemd-udevd to exit. No option except for + <option>--timeout</option> can be specified after this option. + Note that <filename>systemd-udevd.service</filename> contains + <option>Restart=always</option> and so as a result, this option restarts systemd-udevd. + If you want to stop <filename>systemd-udevd.service</filename>, please use the following: + <programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service</programlisting> + </para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-l</option></term> + <term><option>--log-level=<replaceable>value</replaceable></option></term> + <listitem> + <para>Set the internal log level of + <filename>systemd-udevd</filename>. Valid values are the + numerical syslog priorities or their textual + representations: <option>emerg</option>, + <option>alert</option>, <option>crit</option>, + <option>err</option>, <option>warning</option>, + <option>notice</option>, <option>info</option>, and + <option>debug</option>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-s</option></term> + <term><option>--stop-exec-queue</option></term> + <listitem> + <para>Signal systemd-udevd to stop executing new events. Incoming events + will be queued.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-S</option></term> + <term><option>--start-exec-queue</option></term> + <listitem> + <para>Signal systemd-udevd to enable the execution of events.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-R</option></term> + <term><option>--reload</option></term> + <listitem> + <para>Signal systemd-udevd to reload the rules files and other databases like the kernel + module index. Reloading rules and databases does not apply any changes to already + existing devices; the new configuration will only be applied to new events.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-p</option></term> + <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term> + <listitem> + <para>Set a global property for all events.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-m</option></term> + <term><option>--children-max=</option><replaceable>value</replaceable></term> + <listitem> + <para>Set the maximum number of events, systemd-udevd will handle at the + same time.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>--ping</option></term> + <listitem> + <para>Send a ping message to systemd-udevd and wait for the reply. This may be useful to check that + systemd-udevd daemon is running.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-t</option></term> + <term><option>--timeout=</option><replaceable>seconds</replaceable></term> + <listitem> + <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + + <refsect2><title>udevadm monitor + <arg choice="opt"><replaceable>options</replaceable></arg> + </title> + <para>Listens to the kernel uevents and events sent out by a udev rule + and prints the devpath of the event to the console. It can be used to analyze the + event timing, by comparing the timestamps of the kernel uevent and the udev event. + </para> + <variablelist> + <varlistentry> + <term><option>-k</option></term> + <term><option>--kernel</option></term> + <listitem> + <para>Print the kernel uevents.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-u</option></term> + <term><option>--udev</option></term> + <listitem> + <para>Print the udev event after the rule processing.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-p</option></term> + <term><option>--property</option></term> + <listitem> + <para>Also print the properties of the event.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-s</option></term> + <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term> + <listitem> + <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass. + When this option is specified more than once, then each matching result is ORed, that is, all devices in the specified + subsystems are monitored.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-t</option></term> + <term><option>--tag-match=<replaceable>string</replaceable></option></term> + <listitem> + <para>Filter udev events by tag. Only udev events with a given tag attached will pass. + When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the + specified tags are monitored.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + + <refsect2><title>udevadm test + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg> + </title> + <para>Simulate a udev event run for the given device, and print debug output.</para> + <variablelist> + <varlistentry> + <term><option>-a</option></term> + <term><option>--action=<replaceable>ACTION</replaceable></option></term> + <listitem> + <para>Type of event to be simulated. Possible actions are <literal>add</literal>, + <literal>remove</literal>, <literal>change</literal>, <literal>move</literal>, + <literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>, + and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used + to list the possible actions. The default value is <literal>add</literal>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><option>-N</option></term> + <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term> + <listitem> + <para>Specify when udevadm should resolve names of users + and groups. When set to <constant>early</constant> (the + default), names will be resolved when the rules are + parsed. When set to <constant>late</constant>, names will + be resolved for every event. When set to + <constant>never</constant>, names will never be resolved + and all devices will be owned by root.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + + <refsect2><title>udevadm test-builtin + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg><replaceable>command</replaceable></arg> + <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg> + </title> + <para>Run a built-in command <replaceable>COMMAND</replaceable> + for device <replaceable>DEVPATH</replaceable>, and print debug + output.</para> + <variablelist> + <varlistentry> + <term><option>-a</option></term> + <term><option>--action=<replaceable>ACTION</replaceable></option></term> + <listitem> + <para>Type of event to be simulated. Possible actions are <literal>add</literal>, + <literal>remove</literal>, <literal>change</literal>, <literal>move</literal>, + <literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>, + and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used + to list the possible actions. The default value is <literal>add</literal>.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + + <refsect2> + <title>udevadm wait + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg choice="opt"><replaceable>device|syspath</replaceable></arg> + … + </title> + + <para>Wait for devices or device symlinks being created and initialized by + <command>systemd-udevd</command>. Each device path must start with + <literal>/dev/</literal> or <literal>/sys/</literal>, e.g. <literal>/dev/sda</literal>, + <literal>/dev/disk/by-path/pci-0000:3c:00.0-nvme-1-part1</literal>, + <literal>/sys/devices/pci0000:00/0000:00:1f.6/net/eth0</literal>, or + <literal>/sys/class/net/eth0</literal>. This can take multiple devices. This may be useful for + waiting for devices being processed by <command>systemd-udevd</command> after e.g. partitioning + or formatting the devices.</para> + + <variablelist> + <varlistentry> + <term><option>-t</option></term> + <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term> + <listitem> + <para>Maximum number of seconds to wait for the specified devices or device symlinks being + created, initialized, or removed. The default value is <literal>infinity</literal>.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>--initialized=<replaceable>BOOL</replaceable></option></term> + <listitem> + <para>Check if <command>systemd-udevd</command> initialized devices. Defaults to true. When + false, the command only checks if the specified devices exist. Set false to this setting if + there is no udev rules for the specified devices, as the devices will never be considered + as initialized in that case. See Initialized Devices section below for more details.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>--removed</option></term> + <listitem> + <para>When specified, the command wait for devices being removed instead of created or + initialized. If this is specified, <option>--initialized=</option> will be ignored.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>--settle</option></term> + <listitem> + <para>When specified, also watches the udev event queue, and wait for all queued events + being processed by <command>systemd-udevd</command>.</para> + </listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + + <refsect2> + <title>udevadm lock + <arg choice="opt"><replaceable>options</replaceable></arg> + <arg choice="opt"><replaceable>command</replaceable></arg> + … + </title> + + <para><command>udevadm lock</command> takes an (advisory) exclusive lock on a block device (or all + specified devices), as per <ulink url="https://systemd.io/BLOCK_DEVICE_LOCKING">Locking Block Device + Access</ulink> and invokes a program with the locks taken. When the invoked program exits the locks + are automatically released and its return value is propagated as exit code of <command>udevadm + lock</command>.</para> + + <para>This tool is in particular useful to ensure that + <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + does not probe a block device while changes are made to it, for example partitions created or file + systems formatted. Note that many tools that interface with block devices natively support taking + relevant locks, see for example + <citerefentry project='man-pages'><refentrytitle>sfdisk</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s + <option>--lock</option> switch.</para> + + <para>The command expects at least one block device specified via <option>--device=</option> or + <option>--backing=</option>, and a command line to execute as arguments.</para> + + <variablelist> + <varlistentry> + <term><option>--device=<replaceable>DEVICE</replaceable></option></term> + <term><option>-d <replaceable>DEVICE</replaceable></option></term> + + <listitem><para>Takes a path to a device node of the device to lock. This switch may be used + multiple times (and in combination with <option>--backing=</option>) in order to lock multiple + devices. If a partition block device node is specified the containing "whole" block device is + automatically determined and used for the lock, as per the specification. If multiple devices are + specified, they are deduplicated, sorted by the major/minor of their device nodes and then locked + in order.</para> + + <para>This switch must be used at least once, to specify at least one device to + lock. (Alternatively, use <option>--backing=</option>, see below.)</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--backing=<replaceable>PATH</replaceable></option></term> + <term><option>-b <replaceable>PATH</replaceable></option></term> + + <listitem><para>If a path to a device node is specified, identical to + <option>--device=</option>. However, this switch alternatively accepts a path to a regular file or + directory, in which case the block device of the file system the file/directory resides on is + automatically determined and used as if it was specified with + <option>--device=</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--timeout=<replaceable>SECS</replaceable></option></term> + <term><option>-t <replaceable>SECS</replaceable></option></term> + + <listitem><para>Specifies how long to wait at most until all locks can be taken. Takes a value in + seconds, or in the usual supported time units, see + <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>. If + specified as zero the lock is attempted and if not successful the invocation will immediately + fail. If passed as <literal>infinity</literal> (the default) the invocation will wait indefinitely + until the lock can be acquired. If the lock cannot be taken in the specified time the specified + command will not be executed and the invocation will fail.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--print</option></term> + <term><option>-p</option></term> + + <listitem><para>Instead of locking the specified devices and executing a command, just print the + device paths that would be locked, and execute no command. This command is useful to determine + the "whole" block device in case a partition block device is specified. The devices will be sorted + by their device node major number as primary ordering key and the minor number as secondary + ordering key (i.e. they are shown in the order they'd be locked). Note that the number of lines + printed here can be less than the the number of <option>--device=</option> and + <option>--backing=</option> switches specified in case these resolve to the same "whole" + devices.</para></listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + </variablelist> + </refsect2> + </refsect1> + + <refsect1> + <title>Initialized Devices</title> + + <para>Initialized devices are those for which at least one udev rule already completed execution + – for any action but <literal>remove</literal> — that set a property or other device setting (and + thus has an entry in the udev device database). Devices are no longer considered initialized if a + <literal>remove</literal> action is seen for them (which removes their entry in the udev device + database). Note that devices that have no udev rules are never considered initialized, but might + still be announced via the sd-device API (or similar).</para> + </refsect1> + + <refsect1> + <title>Example</title> + + <example> + <title>Format a File System</title> + + <para>Take a lock on the backing block device while creating a file system, to ensure that + <command>systemd-udevd</command> doesn't probe or announce the new superblock before it is + comprehensively written:</para> + + <programlisting># udevadm lock --device=/dev/sda1 mkfs.ext4 /dev/sda1</programlisting> + </example> + + <example> + <title>Format a RAID File System</title> + + <para>Similar, but take locks on multiple devices at once:</para> + + <programlisting># udevadm lock --device=/dev/sda1 --device=/dev/sdb1 mkfs.btrfs /dev/sda1 /dev/sdb1</programlisting> + </example> + + <example> + <title>Copy in a File System</title> + + <para>Take a lock on the backing block device while copying in a prepared file system image, to ensure + that <command>systemd-udevd</command> doesn't probe or announce the new superblock before it is fully + written:</para> + + <programlisting># udevadm lock -d /dev/sda1 dd if=fs.raw of=/dev/sda1</programlisting> + </example> + </refsect1> + + <refsect1> + <title>See Also</title> + <para><citerefentry> + <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum> + </citerefentry>, + <citerefentry> + <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum> + </citerefentry></para> + </refsect1> +</refentry> |