5 New and updated keymaps.
11 The udev database has changed, After installation of a new udev
12 version, 'udevadm info --convert-db' should be called, to let the new
13 udev/libudev version read the already stored data.
15 udevadm now supports quoting of property values, and prefixing of
17 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
25 udev_device_get_is_initialized()
26 udev_enumerate_add_match_is_initialized()
27 to be able to skip devices the kernel has created , but udev has
31 udev_device_get_usec_since_initialized()
32 to retrieve the "age" of a udev device record.
34 GUdev supports a more generic GUdevEnumerator class, udev TAG
35 handling, device initialization and timestamp now.
37 The counterpart of /sys/dev/{char,block}/$major:$minor,
38 /dev/{char,block}/$major:$minor symlinks are now unconditionally
39 created, even when no rule files exist.
41 New and updated keymaps.
47 GUdev moved from /usr to /.
57 Persistent network naming rules are disabled inside of Qemu/KVM now.
59 New and updated keymaps.
61 Udev gets unconditionally enabled on systemd installations now. There
62 is no longer the need to to run 'systemctl enable udev.service'.
76 New and fixed keymaps.
78 Install systemd service files if applicable.
84 All distribution specific rules are removed from the udev source tree,
85 most of them are no longer needed. The Gentoo rules which allow to support
86 older kernel versions, which are not covered by the default rules anymore
87 has moved to rules/misc/30-kernel-compat.rules.
93 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
94 was removed from udevd.
96 Udevd now checks the kernel commandline for the following variables:
97 udev.log-priority=<syslog priority>
98 udev.children-max=<maximum number of workers>
99 udev.exec-delay=<seconds to delay the execution of RUN=>
100 to help debuging coldplug setups where the loading of a kernel
101 module crashes the system.
103 The subdirectory in the source tree rules/packages has been renamed to
104 rules/arch, anc contains only architecture specific rules now.
114 Now the udev daemon itself, does on startup:
115 - copy the content of /lib/udev/devices to /dev
116 - create the standard symlinks like /dev/std{in,out,err},
117 /dev/core, /dev/fd, ...
118 - use static node information provided by kernel modules
119 and creates these nodes to allow module on-demand loading
120 - possibly apply permissions to all ststic nodes from udev
121 rules which are annotated to match a static node
123 The default mode for a device node is 0600 now to match the kernel
124 created devtmpfs defaults. If GROUP= is specified and no MODE= is
125 given the default will be 0660.
131 Udev now gradually starts to pass control over the primary device nodes
132 and their names to the kernel, and will in the end only manage the
133 permissions of the node, and possibly create additional symlinks.
134 As a first step NAME="" will be ignored, and NAME= setings with names
135 other than the kernel provided name will result in a logged warning.
136 Kernels that don't provide device names, or devtmpfs is not used, will
137 still work as they did before, but it is strongly recommended to use
138 only the same names for the primary device node as the recent kernel
139 provides for all devices.
143 Fix broken firmware loader search path.
149 "udevadm trigger" defaults to "change" events now instead of "add"
150 events. The "udev boot script" might need to add "--action=add" to
151 the trigger command if not already there, in case the initial coldplug
152 events are expected as "add" events.
154 The option "all_partitons" was removed from udev. This should not be
155 needed for usual hardware. Udev can not safely make assumptions
156 about non-existing partition major/minor numbers, and therefore no
157 longer provide this unreliable and unsafe option.
159 The option "ignore_remove" was removed from udev. With devtmpfs
160 udev passed control over device nodes to the kernel. This option
161 should not be needed, or can not work as advertised. Neither
162 udev nor the kernel will remove device nodes which are copied from
163 the /lib/udev/devices/ directory.
165 All "add|change" matches are replaced by "!remove" in the rules and
166 in the udev logic. All types of events will update possible symlinks
167 and permissions, only "remove" is handled special now.
169 The modem modeswitch extra was removed and the external usb_modeswitch
170 program should be used instead.
172 New and fixed keymaps.
182 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
183 depend on the current sysfs layout and the information not available in the
184 deprecated layout. All remaining support for the deprecated sysfs layout is
189 Fix for a possible endless loop in the new input_id program.
195 The option "ignore_device" does no longer exist. There is no way to
196 ignore an event, as libudev events can not be suppressed by rules.
197 It only prevented RUN keys from being executed, which results in an
198 inconsistent behavior in current setups.
200 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
201 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
204 The support for the deprecated IDE devices has been removed from the
205 default set of rules. Distros who still care about non-libata drivers
206 need to add the rules to the compat rules file.
208 The ID_CLASS property on input devices has been replaced by the more accurate
209 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
210 determined by the new "input_id" prober now. Some devices, such as touchpads,
211 can have several classes. So if you previously had custom udev rules which e. g.
212 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
213 ENV{ID_INPUT_KEYBOARD}=="?*".
219 To support DEVPATH strings larger than the maximum file name length, the
220 private udev database format has changed. If some software still reads the
221 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
222 Please do not port anything to the new format again, everything in /dev/.udev
223 is and always was private to udev, and may and will change any time without
226 Multiple devices claiming the same names in /dev are limited to symlinks
227 only now. Mixing identical symlink names and node names is not supported.
228 This reduces the amount of data in the database significantly.
230 NAME="%k" causes a warning now. It's is and always was completely superfluous.
231 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
234 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
235 if they are not the default. To support older kernels, the NAME= rules need to
236 be added to the compat rules file.
238 Symlinks to udevadm with the old command names are no longer resolved to
239 the udevadm commands.
241 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
244 The option "last_rule" does no longer exist. Its use breaks too many
245 things which expect to be run from independent later rules, and is an idication
246 that something needs to be fixed properly instead.
248 The gudev API is no longer marked as experimental,
249 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
250 is enabled by default now. Various projects already depend on introspection
251 information to bind dynamic languages to the gudev interfaces.
257 The udevadm trigger "--retry-failed" option, which is replaced since quite
258 a while by "--type=failed" is removed.
260 The failed tracking was not working at all for a few releases. The RUN
261 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
262 default is not to track any failing RUN executions.
264 New keymaps, new modem, hid2hci updated.
268 Fix possible crash in udevd when worker processes are busy, rules are
269 changed at the same time, and workers get killed to reload the rules.
275 Properties set with ENV{.FOO}="bar" are marked private by starting the
276 name with a '.'. They will not be stored in the database, and not be
277 exported with the event.
279 Firmware files are looked up in:
280 /lib/firmware/updates/$(uname -r)
281 /lib/firmware/updates
282 /lib/firmware/$(uname -r)
286 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
287 ata_id, instead of scsi_id, is the default tool now for ATA devices.
293 The configure options have changed because another library needs to be
294 installed in a different location. Instead of exec_prefix and udev_prefix,
295 libdir, rootlibdir and libexecdir are used. The Details are explained in
298 Event processes now get re-used after they handled an event. This reduces
299 the number of forks and the pressure on the CPU significantly, because
300 cloned event processes no longer cause page faults in the main daemon.
301 After the events have settled, a few worker processes stay around for
302 future events, all others get cleaned up.
304 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
305 Also inotify support is mandatory now to run udev.
307 The format of the queue exported by the udev damon has changed. There is
308 no longer a /dev/.udev/queue/ directory. The current event queue can be
309 accessed with udevadm settle and libudedv.
311 Libudev does not have the unstable API header anymore. From now on,
312 incompatible changes will be handled by bumping the library major version.
314 To build udev from the git tree gtk-doc is needed now. The tarballs will
315 build without it and contain the pre-built documentation. An online copy
317 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
319 The tools from the udev-extras repository have been merged into the main
320 udev repository. Some of the extras have larger external dependencies, and
321 they can be disabled with the configure switch --disable-extras.
327 The program vol_id and the library libvolume_id are removed from the
328 repository. Libvolume_id is merged with libblkid from the util-linux-ng
329 package. Persistent disk links for label and uuid depend on the
330 util-linux-ng version (2.15) of blkid now. Older versions of blkid
331 can not be used with udev.
333 Libudev allows to subscribe to udev events. To prevent unwanted messages
334 to be delivered, and waking up the subscribing process, a filter can be
335 installed, to drop messages inside a kernel socket filter. The filters
336 match on the <subsytem>:<devtype> properties of the device.
337 This is part of the ongoing effort to replace HAL, and switch current
338 users over to directly use libudev.
339 Libudev is still marked as experimental, and its interface might
340 eventually change if needed, but no major changes of the currently exported
341 interface are expected anymore, and a first stable release should happen
344 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
345 is not supported since while and udevd will log an error message at
346 startup. It should still be able to boot-up, but advanced rules and system
347 services which depend on the information not available in the old sysfs
348 format will fail to work correctly.
350 DVB device naming is supplied by the kernel now. In case older kernels
351 need to be supported, the old shell script should be added to a compat
358 The processed udev events get send back to the netlink socket. Libudev
359 provides access to these events. This is work-in-progress, to replace
360 the DeviceKit daemon functionality directly with libudev. There are
361 upcoming kernel changes to allow non-root users to subcribe to these
368 "udevadm settle" now optionally accepts a range of events to wait for,
369 instead of waiting for "all" events.
375 The installed watch for block device metadata changes is now removed
376 during event hadling, because some (broken) tools may be called from udev
377 rules and (wrongly) open the device with write access. After the finished
378 event handling the watch is restored.
384 Device nodes can be watched for changes with inotify with OPTIONS="watch".
385 If closed after being opened for writing, a "change" uevent will occur.
386 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
392 The udevadm test command has no longer a --force option, nodes and symlinks
393 are always updated with a test run now.
395 The udevd daemon can be started with --resolve-names=never to avoid all user
396 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
397 lookup user and groups every time events are handled.
403 We are currently merging the Ubuntu rules in the udev default rules,
404 and get one step closer to provide a common Linux /dev setup, regarding
405 device names, symlinks, and default device permissions. On udev startup,
406 we now expect the following groups to be resolvable to their ids with
408 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
409 LDAP setups need to make sure, that these groups are always resolvable at
410 bootup, with only the rootfs mounted, and without network access available.
412 Some systems may need to add some new, currently not used groups, or need
413 to add some users to new groups, but the cost of this change is minimal,
414 compared to the pain the current, rather random, differences between the
415 various distributions cause for upstream projects and third-party vendors.
417 In general, "normal" users who log into a machine should never be a member
418 of any such group, but the device-access should be managed by dynamic ACLs,
419 which get added and removed for the specific users on login/logout and
420 session activity/inactivity. These groups are only provided for custom setups,
421 and mainly system services, to allow proper privilege separation.
422 A video-streaming daemon uid would be a member of "audio" and "video", to get
423 access to the sound and video devices, but no "normal" user should ever belong
424 to the "audio" group, because he could listen to the built-in microphone with
425 any ssh-session established from the other side of the world.
427 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
428 which do not depend on the kernel device name. As usual, unique
429 devices - only a single one per product connected, or a real
430 USB serial number in the device - are always found with the same
431 name in the by-id/ directory.
432 Completely identical devices may overwrite their names in by-id/
433 and can only be found reliably in the by-path/ directory. Devices
434 specified by by-path/ must not change their connection, like the
435 USB port number they are plugged in, to keep their name.
437 To support some advanced features, Linux 2.6.22 is the oldest supported
438 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
439 supported. Older kernels should still work, and devices nodes should be
440 reliably created, but some rules and libudev will not work correctly because
441 the old kernels do not provide the expected information or interfaces.
447 Fix for a possible segfault while swapping network interface names in udev
454 The group "video" is part of the default rules now.
458 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
459 block devices in some cases. No common distro uses this option anymore,
460 and we do not get enough testing for this and recent udev versions. If
461 this option is not needed to run some old distro with a new kernel,
462 it should be disabled in the kernel config.
464 Bugfix for the $links substitution variable, which may crash if no links
465 are created. This should not happen in usual setups because we always
466 create /dev/{block,char}/ links.
468 The strings of the parsed rules, which are kept in memory, no longer
469 contain duplicate entries, or duplicate tails of strings. This, and the
470 new rules parsing/matching code reduces the total in-memory size of
471 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
474 The export of DEVTYPE=disk/partition got removed from the default
475 rules. This value is available from the kernel. The pnp shell script
476 modprobe hack is removed from the default rules. ACPI devices have _proper_
477 modalias support and take care of the same functionality.
478 Installations which support old kernels, but install current default
479 udev rules may want to add that to the compat rules file.
481 Libvolume_id now always probes for all known filesystems, and does not
482 stop at the first match. Some filesystems are marked as "exclusive probe",
483 and if any other filesytem type matches at the same time, libvolume_id
484 will, by default, not return any probing result. This is intended to prevent
485 mis-detection with conflicting left-over signatures found from earlier
486 file system formats. That way, we no longer depend on the probe-order
487 in case of multiple competing signatures. In some setups the kernel allows
488 to mount a volume with just the old filesystem signature still in place.
489 This may damage the new filesystem and cause data-loss, just by mounting
490 it. Because volume_id can not decide which one the correct signature is,
491 the wrong signatures need to be removed manually from the volume, or the
492 volume needs to be reformatted, to enable filesystem detection and possible
497 Fix segfault if compiled without optimization and dbg() does not get
498 compiled out and uses variables which are not available.
502 Bugfixes. (And maybe new bugs. :))
504 The rule matching engine got converted from a rule list to a token
505 array which reduced the in-memory rules representation of a full
506 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
507 Limits like 5 ENV and ATTR matches, and one single instance for most
508 other keys per rule are gone.
510 The NAME assignment is no longer special cased. If later rules assign
511 a NAME value again, the former value will be overwritten. As usual
512 for most other keys, the NAME value can be protected by doing a final
513 assignment with NAME:="<value>".
515 All udev code now uses libudev, which is also exported. The library
516 is still under development, marked as experimental, and its interface
517 may change as long as the DeviceKit integration is not finished.
519 Many thanks to Alan Jenkins for his continuous help, and finding and
520 optimizing some of the computing expensive parts.
526 Kernel devices and device nodes are connected now by reverse indizes in
527 /sys and /dev. A device number retrieved by a stat() or similar, the
528 kernel device directory can be found by looking up:
529 /sys/dev/{block,char}/<maj>:<min>
530 and the device node of the same device by looking up:
531 /dev/{block,char}/<maj>:<min>
535 Fix recently introduced bug, which caused a compilation without large
536 file support, where vol_id does not recognize raid signatures at the end
539 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
540 Seems some kernel versions prevent the creation of the ieee-* links,
541 so people used the scsi-* link which disappeared now.
543 More libudev work. Almost all udevadm functionality comes from libudev
546 udevadm trigger has a new option --type, which allows to trigger events
547 for "devices", for "subsystems", or "failed" devices. The old option
548 --retry-failed" still works, but is no longer mentioned in the man page.
554 The udevadm info --device-id-of-file= output has changed to use
555 the obvious format. Possible current users should use the --export
556 option which is not affected.
558 The old udev commands symlinks to udevadm are not installed, if
559 these symlinks are used, a warning is printed.
565 Optical drive's media is no longer probed for raid signatures,
566 reading the end of the device causes some devices to malfunction.
567 Also the offset of the last session found is used now to probe
570 The volume_id library got a major version number update to 1,
571 some deprecated functions are removed.
573 A shared library "libudev" gets installed now to provide access
574 to udev device information. DeviceKit, the successor of HAL, will
575 need this library to access the udev database and search sysfs for
577 The library is currently in an experimental state, also the API is
578 expected to change, as long as the DeviceKit integration is not
583 We use ./configure now. See INSTALL for details. Current
586 "/usr" - prefix for man pages, include files
588 "" - the root filesystem, prefix for libs and binaries
592 "lib" - directory name for libraries, not a path name
593 multilib 64bit systems may use "lib64" instead of "lib"
595 compile-in verbose debug messages
597 disable all logging and compile-out all log strings
599 link against SELInux libraries, to set the expected context
602 In the default rules, the group "disk" gets permissions 0660 instead
603 of 0640. One small step closer to unify distro rules. Some day, all
604 distros hopefully end up with the same set of rules.
606 No symlinks to udevadm are installed anymore, if they are still needed,
607 they should be provided by the package.
613 Default udev rules, which are not supposed to be edited by the user, should
614 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
615 the udev package and will be replaced with an update. Udev will pick up rule
617 /lib/udev/rules.d/ - default installed rules
618 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
619 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
620 It does not matter in which directory a rule file lives, all files are sorted
623 To help creating /dev/root, we have now:
624 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
627 In case the current --device-id-of-file is already used, please switch to
628 the --export format version, it saves the output parsing and the old
629 format will be changed to use ':' as a separator, like the format in the
634 Fix cdrom_id to properly recognize blank media.
640 Tape drive id-data is queried from /dev/bsg/* instead of the tape
641 nodes. This avoids rewinding tapes on open().
647 The symlinks udevcontrol and udevtrigger are no longer installed by
650 The scsi_id program does not depend on sysfs anymore. It can speak
651 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
652 data, which should solve some old problems with tape devices, where
653 we better do not open all tape device nodes to identify the device.
659 The cdrom_id program is replaced by an advanced version, which can
660 detect most common device types, and also properties of the inserted
661 media. This is part of moving some basic functionality from HAL into
662 udev (and the kernel).
668 The last WAIT_FOR_SYSFS rule is removed from the default rules.
670 The symlinks to udevadm for the debugging tools: udevmonitor and
671 udevtest are no longer created.
673 The symlinks to the udevadm man page for the old tool names are
676 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
677 should be prefixed with '@' to indicate that the path is not a
688 Udevstart is removed from the tree, it did not get installed for
689 a long time now, and is long replaced by trigger and settle.
695 All udev tools are merged into a single binary called udevadm.
696 The old names of the tools are built-in commands in udevadm now.
697 Symlinks to udevadm, with the names of the old tools, provide
698 the same functionality as the standalone tools. There is also
699 only a single udevadm.8 man page left for all tools.
701 Tools like mkinitramfs should be checked, if they need to include
702 udevadm in the list of files.
712 The etc/udev/rules.d/ directory now contains a default set of basic
713 udev rules. This initial version is the result of a rules file merge
714 of Fedora and openSUSE. For these both distros only a few specific
715 rules are left in their own file, named after the distro. Rules which
716 are optionally installed, because they are only valid for a specific
717 architecture, or rules for subsystems which are not always used are
718 in etc/udev/packages/.
724 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
725 actions by dynamically created rules.
727 SYMLINK=="<value>" matches agains the entries in the list of
728 currently defined symlinks. The links are not created in the
729 filesystem at that point in time, but the values can be matched.
731 RUN{ignore_error}+="<program>" will ignore any exit code from the
732 program and not record as a failed event.
738 Final merge of patches/features from the Ubuntu package.
744 Control characters in filesystem label strings are no longer silenty
745 removed, but hex-encoded, to be able to uniquely identify the device
746 by its symlink in /dev/disk/by-label/.
747 If libvolume_id is used by mount(8), LABEL= will work as expected,
748 if slashes or other characters are used in the label string.
750 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
751 can be specified now. The TEST key accepts an optional mode mask
752 TEST{0100}=="<is executable file>".
754 Scsi_id now supports a mode without expecting scsi-specific sysfs
755 entries to allow the extraction of cciss-device persistent properties.
761 In the future, we may see uuid's which are just simple character
762 strings (see the DDF Raid Specification). For that reason vol_id now
763 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
764 the creation of symlinks, the *_SAFE values ensure, that no control
765 or whitespace characters are used in the filename.
767 Possible users of libvolume_id, please use the volume_id_get_* functions.
768 The public struct will go away in a future release of the library.
774 Removal of useless extras/eventrecorder.sh.
784 The directory multiplexer for dev.d/ and hotplug.d are finally removed
785 from the udev package.
791 Symlinks can have priorities now, the priority is assigned to the device
792 and specified with OPTIONS="link_priority=100". Devices with higher
793 priorities overwrite the symlinks of devices with lower priorities.
794 If the device that currently owns the link, goes away, the symlink
795 will be removed, and recreated, pointing to the next device with the
796 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
797 more reliable, if multiple devices contain the same metadata and overwrite
800 The dasd_id program is removed from the udev tree, and dasdinfo, with the
801 needed rules, are part of the s390-tools now.
803 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
804 we may get the scsi sysfs mess fixed some day, and this will only catch
805 the devices we are looking for.
807 USB serial numbers for storage devices have the target:lun now appended,
808 to make it possibble to distinguish broken multi-lun devices with all
809 the same SCSI identifiers.
811 Note: The extra "run_directory" which searches and executes stuff in
812 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
813 with the next release. Make sure, that you don't use it anymore, or
814 provides your own implementation of that inefficient stuff.
815 We are tired of reports about a "slow udev", because these directories
816 contain stuff, that runs with _every_ event, instead of using rules,
817 that run programs only for the matching events.
827 DRIVER== will match only for devices that actually have a real
828 driver. DRIVERS== must be used, if parent devices should be
829 included in the match.
831 Libvolume_id's "linux_raid" detection needed another fix.
839 Add additional check to volume_id detection of via_raid, cause
840 some company decided to put a matching pattern all over the empty
841 storage area of their music players.
845 Fix path_id for SAS devices.
849 The udev daemon can be started with --debug-trace now, which will
850 execute all events serialized to get a chance to catch a possible
851 action that crashes the box.
853 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
854 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
855 are excluded from the warning. Referencing parent attributes directly
856 may break when something in the kernel driver model changes. Udev will
857 just find the attribute by walking up the parent chain.
859 Udevtrigger now sorts the list of devices depending on the device
860 dependency, so a "usb" device is triggered after the parent "pci"
865 Revert persistent-storage ata-serial '_' '-' replacement.
871 Udevtrigger can now filter the list of devices to be triggered. Matches
872 for subsystems or sysfs attributes can be specified.
874 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
875 zero-sized files to avoid pointing to /sys and confuse broken tools which
876 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
879 The rules and scripts to create udev rules for persistent network
880 devices and optical drives are in the extras/rules_generator directory
881 now. If you use something similar, please consider replacing your own
882 version with this, to share the support effort. The rule_generator
883 installs its own rules into /etc/udev/rules.d.
885 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
886 the rule_generator depends on cdrom_id to be called in an earlier rule.
892 Renaming of some key names (the old names still work):
893 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
894 (The behavior of the key DRIVER will change soon in one of the next
895 releases, to match only the event device, please switch to DRIVERS
896 instead. If DRIVER is used, it will behave like DRIVERS, but an error
898 With the new key names, we have a more consistent and simpler scheme.
899 We can match the properties of the event device only, with: KERNEL,
900 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
901 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
902 longer mentioned in the man page and should be switched in the rule
905 ATTR{file}="value" can be used now, to write to a sysfs file of the
906 event device. Instead of:
907 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
909 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
911 All the PHYSDEV* keys are deprecated and will be removed from a
913 PHYDEVPATH - is the path of a parent device and should not be
915 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
916 matched with SUBSYSTEMS==
917 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
918 Newer kernels will have DRIVER in the environment,
919 for older kernels udev puts in. Class device will
920 no longer carry this property of a parent and
921 DRIVERS== can be used to match such a parent value.
922 Note that ENV{DRIVER} is only available for a few bus devices, where
923 the driver is already bound at device event time. On coldplug, the
924 events for a lot devices are already bound to a driver, and they will have
925 that value set. But on hotplug, at the time the kernel creates the device,
926 it can't know what driver may claim the device after that, therefore
927 in most cases it will be empty.
929 Failed events should now be re-triggered with:
930 udevtrigger --retry-failed.
931 Please switch to this command, so we keep the details of the /dev/.udev/failed/
932 files private to the udev tools. We may need to switch the current symlink
933 target, cause some obviously broken tools try to scan all files in /dev
934 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
935 million times. This takes ages on slow boxes.
937 The udevinfo attribute walk (-a) now works with giving a device node
938 name (-n) instead of a devpath (-p). The query now always works, also when
939 no database file was created by udev.
941 The built-in /etc/passwd /etc/group parser is removed, we always depend on
942 getpwnam() and getgrnam() now. One of the next releases will depend on
943 fnmatch() and may use getopt_long().
947 Bugfixes and small improvements.
951 Fix path_id for recent kernels.
957 Added support for swapping network interface names, by temporarily
958 renaming the device and wait for the target name to become free.
962 The built-in MODALIAS key and substitution is removed.
966 The binary firmware helper is replaced by the usual simple
967 shell script. Udevsend is removed from the tree.
975 Some more keys require the correct use of '==' and '=' depending
976 on the kind of operation beeing an assignment or a match. Rules
977 with invalid operations are skipped and logged to syslog. Please
978 test with udevtest if the parsing of your rules throws errors and
979 fix possibly broken rules.
983 Provide "udevsettle" to wait for all current udev events to finish.
984 It also watches the current kernel netlink queue by comparing the
985 even sequence number to make sure that there are no current pending
986 events that have not already arrived in the daemon.
990 Fix rule to skip persistent rules for removable IDE devices, which
991 also skipped optical IDE drives.
993 All *_id program are installed in /lib/udev/ by default now.
995 No binary is stripped anymore as this should be done in the
996 packaging process and not at build time.
998 libvolume_id is provided as a shared library now and vol_id is
999 linked against it. Also one of the next HAL versions will require
1000 this library, and the HAL build process will also require the
1001 header file to be installed. The copy of the same code in HAL will
1002 be removed to have only a single copy left on the system.
1006 Add persistent links for SCSI tapes. The rules file is renamed
1007 to 60-persistent-storage.rules.
1009 Create persistent path for usb devices. Can be used for all sorts
1010 of devices that can't be distinguished by other properties like
1011 multiple identical keyboards and mice connected to the same box.
1013 Provide "udevtrigger" program to request events on coldplug. The
1014 shell script is much too slow with thousends of devices.
1018 Fix persistent disk rules to exclude removable IDE drives.
1020 Warn if %e, $modalias or MODALIAS is used.
1024 Fix queue export, which wasn't correct for subsequent add/remove
1025 events for the same device.
1029 Fix cramfs detection on big endian.
1031 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1036 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1037 attributes were only checked at the parent device that matched the
1038 by BUS requested subsystem. Fix it to also look at the device we
1039 received the event for.
1041 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1046 Fix a bug where NAME="" would prevent RUN from beeing executed.
1048 RUN="/bin/program" does not longer automatically add the subsystem
1049 as the first parameter. This is from the days of /sbin/hotplug
1050 which is dead now and it's just confusing to need to add a space at
1051 the end of the program name to prevent this.
1052 If you use rules that need the subsystem as the first parameter,
1053 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1054 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1058 The udev man page has moved to udev(7) as it does not describe a command
1059 anymore. The programs udev, udevstart and udevsend are no longer installed
1060 by default and must be copied manually, if they should be installed or
1061 included in a package.
1063 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1064 the ignore rule was applied.
1066 More preparation for future sysfs changes. usb_id and scsi_id no longer
1067 depend on a magic order of devices in the /devices chain. Specific devices
1068 should be requested by their subsytem.
1070 This will always find the scsi parent device without depending on a specific
1072 dev = sysfs_device_get(devpath);
1073 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1075 The "device" link in the current sysfs layout will be automatically
1076 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1077 parent in the devpath. If a device is requested by it's symlink, like all
1078 class devices in the new sysfs layout will look like, it gets automatically
1079 resolved and substituted with the real devpath and not the symlink path.
1082 A similar logic must be applied to _all_ sysfs users, including
1083 scripts, that search along parent devices in sysfs. The explicit use of
1084 the "device" link must be avoided. With the future sysfs layout all
1085 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1086 back to the "class" or the "bus". The layout of the parent devices in
1087 /devices is not necessarily expected to be stable across kernel releases and
1088 searching for parents by their subsystem should make sysfs users tolerant
1089 for changed parent chains.
1093 Prepare udev to work with the experimental kernel patch, that moves
1094 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1096 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1097 moving the class devices to /sys/devices.
1099 Thanks again to Marco for help finding a hopefully nice compromise
1100 to make %b simpler and working again.
1104 Complete removal of libsysfs, replaced by simple helper functions
1105 which are much simpler and a bit faster. The udev daemon operatesentirely
1106 on event parameters and does not use sysfs for simple rules anymore.
1107 Please report any new bugs/problems, that may be caused by this big
1108 change. They will be fixed immediately.
1110 The enumeration format character '%e' is deprecated and will be
1111 removed sometimes from a future udev version. It never worked correctly
1112 outside of udevstart, so we can't use it with the new parallel
1113 coldplug. A simple enumeration is as useless as the devfs naming
1114 scheme, just get rid of both if you still use it.
1116 MODALIAS and $modalias is not needed and will be removed from one of
1117 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1118 the sysfs "modalias" value.
1120 Thanks a lot to Marco for all his help on finding and fixing bugs.
1124 Let scsi_id request libata drive serial numbers from page 0x80.
1126 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1127 added /dev/disk/by-name/* for device mapper device names.
1129 Removed %e from the man page. It never worked reliably outside
1130 of udevstart and udevstart is no longer recommended to use.
1134 Symlinks are now exported to the event environment. Hopefully it's no
1135 longer needed to run udevinfo from an event process, like it was
1136 mentioned on the hotplug list:
1137 UDEV [1134776873.702967] add@/block/sdb
1140 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1144 Fix a problem if udevsend is used as the hotplug handler and tries to use
1145 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1146 and this kind of problems will hopefully go away soon.
1150 All built-in logic to work around bad sysfs timing is removed with this
1151 version. The need to wait for sysfs files is almost fixed with a kernel
1152 version that doesn't work with this udev version anyway. Until we fix
1153 the timing of the "bus" link creation, the former integrated logic should
1154 be emulated by a rule placed before all other rules:
1155 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1157 The option "udev_db" does no longer exist. All udev state will be in
1158 /$udev_root/.udev/ now, there is no longer an option to set this
1160 If the init script or something else used this value, just depend on
1161 this hardcoded path. But remember _all_content_ of this directory is
1162 still private to udev and can change at any time.
1164 Default location for rule sripts and helper programs is now: /lib/udev/.
1165 Everything that is not useful on the commandline should go into this
1166 directory. Some of the helpers in the extras folder are installed there
1167 now. The rules need to be changed, to find the helpers there.
1169 Also /lib/udev/devices is recommended as a directory where packages or
1170 the user can place real device nodes, which get copied over to /dev at
1171 every boot. This should replace the various solutions with custom config
1174 Udevsend does no longer start the udev daemon. This must be done with
1175 the init script that prepares /dev on tmpfs and creates the initial nodes,
1176 before starting the daemon.
1180 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1183 The copy of klibc is removed. A systemwide installed version of klibc
1184 should be used to build a klibc udev now.
1188 NAME="" will not create any nodes, but execute RUN keys. To completely
1189 ignore an event the OPTION "ignore_device" should be used.
1191 After removal of the reorder queue, events with a TIMEOUT can be executed
1192 without any queuing now.
1196 Fixed bug in udevd, if inotify is not available. We depend on netlink
1197 uevents now, kernels without that event source will not work with that
1198 version of udev anymore.
1202 The rule parsing happens now in the daemon once at startup, all udev
1203 event processes inherit the already parsed rules from the daemon.
1204 It is shipped with SUSE10.0 and reduces heavily the system load at
1205 startup. The option to save precompiled rules and let the udev process
1206 pick the them up is removed, as it's no longer needed.
1208 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1209 device. Libsysfs is changed to "translate" the requested link into the
1210 real device path, as it would happen with the hotplug event. Otherwise
1211 device removal and the udev database will not work.
1213 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1216 A few improvements for vol_id, the filesytem probing code.
1220 Fix a stupid typo in extras/run_directory for "make install".
1222 scsi_id creates the temporary devnode now in /dev for usage with a
1223 non-writable /tmp directory.
1225 The uevent kernel socket buffer can carry app. 50.000 events now,
1226 let's see who can break this again. :)
1228 The upcoming kernel will have a new input driver core integration.
1229 Some class devices are now symlinks to the real device. libsysfs
1230 needs a fix for this to work correctly. Udevstart of older udev
1231 versions will _not_ create these devices!
1235 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1240 A bunch of mostly trivial bugfixes. From now on no node name or
1241 symlink name can contain any character than plain whitelisted ascii
1242 characters or validated utf8 byte-streams. This is needed for the
1243 /dev/disk/by-label/* links, because we import untrusted data and
1244 export it to the filesystem.
1248 More bugfixes. If udevd was started from the kernel, we don't
1249 have stdin/stdout/stderr, which broke the forked tools in some
1254 Bugfix. udevstart event ordering was broken for a long time.
1255 The new run_program() uncovered it, because /dev/null was not
1256 available while we try to run external programs.
1257 Now udevstart should create it before we run anything.
1261 Minor bugfixes and some distro rules updates. If you don't have the
1262 persistent disk rules in /dev/disk/by-*/* on your distro, just
1263 grab it from here. :)
1267 We can use socket communication now to pass events from udev to
1269 RUN+="socket:/org/freedesktop/hal/udev_event"
1270 will pass the whole udev event to the HAL daemon without the need
1271 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1275 Mostly bugfixes and see ChangeLog.
1277 The test for the existence of an environment value should be
1279 ENV{KEY}=="*" to ENV{KEY}=="?*"
1280 because "*" will not fail anymore, if the key does not exist or
1285 Bugfixes and a few tweaks described in the ChangeLog.
1289 Mostly a Bugfix release.
1291 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1292 timing with custom rules.
1296 We changed the internal rule storage format. Our large rule files took
1297 2 MB of RAM, with the change we are down to 99kB.
1299 If the device-node has been created with default name and no symlink or
1300 options are to remenber, it is not longer stored in the udevdb. HAL will
1301 need to be updated to work correctly with that change.
1303 To overrride optimization flags, OPTFLAGS may be used now.
1311 Major changes happened with this release. The goal is to take over the
1312 complete kernel-event handling and provide a more efficient way to dispatch
1313 kernel events. Replacing most of the current shell script logic and the
1314 kernel forked helper with a netlink-daemon and a rule-based event handling.
1316 o udevd listens to netlink events now. The first valid netlink event
1317 will make udevd ignore any message from udevsend that contains a
1318 SEQNUM, to avoid duplicate events. The forked events can be disabled
1320 echo "" > /proc/sys/kernel/hotplug
1321 For full support, the broken input-subsytem needs to be fixed, not to
1322 bypass the driver core.
1324 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1325 removed from udev itself and must be emulated by calling small
1326 helper binaries provided in the extras folder:
1327 make EXTRAS=extras/run_directory/
1328 will build udev_run_devd and udev_run_hotplugd, which can be called
1329 from a rule if needed:
1330 RUN+="/sbin/udev_run_hotplugd"
1331 The recommended way to handle this is to convert all the calls from
1332 the directories to explicit udev rules and get completely rid of the
1333 multiplexing. (To catch a ttyUSB event, you now no longer need to
1334 fork and exit 300 tty script instances you are not interested in, it
1335 is just one rule that matches exactly the device.)
1337 o udev handles now _all_ events not just events for class and block
1338 devices, this way it is possible to control the complete event
1339 behavior with udev rules. Especially useful for rules like:
1340 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1342 o As used in the modalias rule, udev supports now textual
1343 substitution placeholder along with the usual format chars. This
1344 needs to be documented, for now it's only visible in udev_rules_parse.c.
1346 o The rule keys support now more operations. This is documented in the
1347 man page. It is possible to add values to list-keys like the SYMLINK
1348 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1349 Also "final"-assignments are supported by using KEY:="value", which will
1350 prevent changing the key by any later rule.
1352 o kernel 2.6.12 has the "detached_state" attribute removed from
1353 sysfs, which was used to recognize sysfs population. We switched that
1354 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1355 Running this udev version on older kernels may cause a short delay for
1358 o To provide infrastructure for persistent device naming, the id programs:
1359 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1360 to export the probed data in environment key format:
1361 pim:~ # /sbin/ata_id --export /dev/hda
1362 ID_MODEL=HTS726060M9AT00
1363 ID_SERIAL=MRH401M4G6UM9B
1364 ID_REVISION=MH4OA6BA
1366 The following rules:
1367 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1368 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1371 kay@pim:~> tree /dev/disk
1374 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1375 | `-- IBM-Memory_Key -> ../../sda
1377 | |-- swap -> ../../hda1
1378 | |-- date -> ../../sda1
1379 | `-- home -> ../../hda3
1381 |-- 2E08712B0870F2E7 -> ../../hda3
1382 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1383 |-- E845-7A89 -> ../../sda1
1384 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1386 The IMPORT= operation will import these keys in the environment and make
1387 it available for later PROGRAM= and RUN= executed programs. The keys are
1388 also stored in the udevdb and can be queried from there with one of the
1391 o A few binaries are silently added to the repository, which can be used
1392 to replay kernel events from initramfs instead of using coldplug. udevd
1393 can be instructed now to queue-up events while the stored events from
1394 initramfs are filled into the udevd-queue. This code is still under
1395 development and there is no documentation now besides the code itself.
1396 The additional binaries get compiled, but are not installed by default.
1398 o There is also a temporary fix for a performance problem where too many
1399 events happen in parallel and every event needs to parse the rules.
1400 udev can now read precompiled rules stored on disk. This is likely to be
1401 replaced by a more elegant solution in a future udev version.
1405 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1406 Fix for libsysfs not to expect this file was added.
1410 All rules are applied now, but only the first matching rule with a NAME-key
1411 will be applied. All later rules with NAME-key are completely ignored. This
1412 way system supplied symlinks or permissions gets applied to user-defined
1416 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1417 to some rules, to keep the old behavior.
1419 The rules are read on "remove"-events too. That makes is possible to match
1420 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1421 instruct udev to ignore an event (OPTIONS="ignore_device").
1422 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1424 The new RUN-key supports rule-based execution of programs after device-node
1425 handling. This is meant as a general replacement for the dev.d/-directories
1426 to give fine grained control over the execution of programs.
1428 The %s{}-sysfs format char replacement values are searched at any of the
1429 devices in the device chain now, not only at the class-device.
1431 We support log priority levels now. The value udev_log in udev.conf is used
1432 to determine what is printed to syslog. This makes it possible to
1433 run a version with compiled-in debug messages in a production environment
1434 which is sometimes needed to find a bug.
1435 It is still possible to supress the inclusion of _any_ syslog usage with
1436 USE_LOG=false to create the smallest possible binaries if needed.
1437 The configured udev_log value can be overridden with the environment variable
1442 Possible use of a system-wide klibc:
1443 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1444 will link against an external klibc and our own version will be ignored.
1448 We support an unlimited count of symlinks now.
1450 If USE_STATIC=true is passed to a glibc build, we link statically and use
1451 a built-in userdb parser to resolve user and group names.
1453 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1454 we walk up the chain of physical devices to find a match.
1456 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1457 easy to skip certain attribute matches without composing rules with weird
1458 character class negations like:
1459 KERNEL="[!s][!c][!d]*"
1460 this can now be replaced with:
1462 The current simple '=' is still supported, and should work as it does today,
1463 but existing rules should be converted if possible, to be better readable.
1465 We have new ENV{}== key now, to match against a maximum of 5 environment
1468 udevstart is its own binary again, because we don't need co carry this araound
1469 with every forked event.