5 warning if /run is not writable.
9 udevadm info --cleanup-db
11 systemd netlink socket activation
12 stop socket or mask on rpm update
15 hard event timeout now. hanging programs will be killed
21 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
22 /run mountpoint is supposed to be a tmpfs mounted during early boot,
23 available and writable to for all tools at any time during bootup,
24 it replaces /var/run/, which should become a symlink some day.
26 If /run does not exist, or is not writable, udev will fall back using
29 On systemd systems with initramfs and LVM used, packagers must
30 make sure, that the systemd and initramfs versions match. The initramfs
31 needs to create the /run mountpoint for udev to store the data, and
32 mount this tmpfs to /run in the rootfs, so the that the udev database
33 is preserved for the udev version started in the rootfs.
35 The command 'udevadm info --convert-db' is gone. The udev daemon
36 itself, at startup, converts any old database version if necessary.
38 The systemd services files have been reorganized. The udev control
39 socket is bound by systemd and passed to the started udev daemon.
40 The udev-settle.service is no longer active by default. Services which
41 can not handle hotplug setups properly need to actively pull it in, to
42 act like a barrier. Alternatively the settle service can be unconditionally
43 'systemctl'enabled, and act like a barrier for basic.target.
45 The fstab_import callout is no longer built or installed. Udev
46 should not be used to mount, does not watch changes to fstab, and
47 should not mirror fstab values in the udev database.
53 New and updated keymaps.
59 The udev database has changed, After installation of a new udev
60 version, 'udevadm info --convert-db' should be called, to let the new
61 udev/libudev version read the already stored data.
63 udevadm now supports quoting of property values, and prefixing of
65 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
73 udev_device_get_is_initialized()
74 udev_enumerate_add_match_is_initialized()
75 to be able to skip devices the kernel has created , but udev has
79 udev_device_get_usec_since_initialized()
80 to retrieve the "age" of a udev device record.
82 GUdev supports a more generic GUdevEnumerator class, udev TAG
83 handling, device initialization and timestamp now.
85 The counterpart of /sys/dev/{char,block}/$major:$minor,
86 /dev/{char,block}/$major:$minor symlinks are now unconditionally
87 created, even when no rule files exist.
89 New and updated keymaps.
95 GUdev moved from /usr to /.
105 Persistent network naming rules are disabled inside of Qemu/KVM now.
107 New and updated keymaps.
109 Udev gets unconditionally enabled on systemd installations now. There
110 is no longer the need to to run 'systemctl enable udev.service'.
124 New and fixed keymaps.
126 Install systemd service files if applicable.
132 All distribution specific rules are removed from the udev source tree,
133 most of them are no longer needed. The Gentoo rules which allow to support
134 older kernel versions, which are not covered by the default rules anymore
135 has moved to rules/misc/30-kernel-compat.rules.
141 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
142 was removed from udevd.
144 Udevd now checks the kernel commandline for the following variables:
145 udev.log-priority=<syslog priority>
146 udev.children-max=<maximum number of workers>
147 udev.exec-delay=<seconds to delay the execution of RUN=>
148 to help debuging coldplug setups where the loading of a kernel
149 module crashes the system.
151 The subdirectory in the source tree rules/packages has been renamed to
152 rules/arch, anc contains only architecture specific rules now.
162 Now the udev daemon itself, does on startup:
163 - copy the content of /lib/udev/devices to /dev
164 - create the standard symlinks like /dev/std{in,out,err},
165 /dev/core, /dev/fd, ...
166 - use static node information provided by kernel modules
167 and creates these nodes to allow module on-demand loading
168 - possibly apply permissions to all ststic nodes from udev
169 rules which are annotated to match a static node
171 The default mode for a device node is 0600 now to match the kernel
172 created devtmpfs defaults. If GROUP= is specified and no MODE= is
173 given the default will be 0660.
179 Udev now gradually starts to pass control over the primary device nodes
180 and their names to the kernel, and will in the end only manage the
181 permissions of the node, and possibly create additional symlinks.
182 As a first step NAME="" will be ignored, and NAME= setings with names
183 other than the kernel provided name will result in a logged warning.
184 Kernels that don't provide device names, or devtmpfs is not used, will
185 still work as they did before, but it is strongly recommended to use
186 only the same names for the primary device node as the recent kernel
187 provides for all devices.
191 Fix broken firmware loader search path.
197 "udevadm trigger" defaults to "change" events now instead of "add"
198 events. The "udev boot script" might need to add "--action=add" to
199 the trigger command if not already there, in case the initial coldplug
200 events are expected as "add" events.
202 The option "all_partitons" was removed from udev. This should not be
203 needed for usual hardware. Udev can not safely make assumptions
204 about non-existing partition major/minor numbers, and therefore no
205 longer provide this unreliable and unsafe option.
207 The option "ignore_remove" was removed from udev. With devtmpfs
208 udev passed control over device nodes to the kernel. This option
209 should not be needed, or can not work as advertised. Neither
210 udev nor the kernel will remove device nodes which are copied from
211 the /lib/udev/devices/ directory.
213 All "add|change" matches are replaced by "!remove" in the rules and
214 in the udev logic. All types of events will update possible symlinks
215 and permissions, only "remove" is handled special now.
217 The modem modeswitch extra was removed and the external usb_modeswitch
218 program should be used instead.
220 New and fixed keymaps.
230 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
231 depend on the current sysfs layout and the information not available in the
232 deprecated layout. All remaining support for the deprecated sysfs layout is
237 Fix for a possible endless loop in the new input_id program.
243 The option "ignore_device" does no longer exist. There is no way to
244 ignore an event, as libudev events can not be suppressed by rules.
245 It only prevented RUN keys from being executed, which results in an
246 inconsistent behavior in current setups.
248 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
249 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
252 The support for the deprecated IDE devices has been removed from the
253 default set of rules. Distros who still care about non-libata drivers
254 need to add the rules to the compat rules file.
256 The ID_CLASS property on input devices has been replaced by the more accurate
257 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
258 determined by the new "input_id" prober now. Some devices, such as touchpads,
259 can have several classes. So if you previously had custom udev rules which e. g.
260 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
261 ENV{ID_INPUT_KEYBOARD}=="?*".
267 To support DEVPATH strings larger than the maximum file name length, the
268 private udev database format has changed. If some software still reads the
269 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
270 Please do not port anything to the new format again, everything in /dev/.udev
271 is and always was private to udev, and may and will change any time without
274 Multiple devices claiming the same names in /dev are limited to symlinks
275 only now. Mixing identical symlink names and node names is not supported.
276 This reduces the amount of data in the database significantly.
278 NAME="%k" causes a warning now. It's is and always was completely superfluous.
279 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
282 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
283 if they are not the default. To support older kernels, the NAME= rules need to
284 be added to the compat rules file.
286 Symlinks to udevadm with the old command names are no longer resolved to
287 the udevadm commands.
289 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
292 The option "last_rule" does no longer exist. Its use breaks too many
293 things which expect to be run from independent later rules, and is an idication
294 that something needs to be fixed properly instead.
296 The gudev API is no longer marked as experimental,
297 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
298 is enabled by default now. Various projects already depend on introspection
299 information to bind dynamic languages to the gudev interfaces.
305 The udevadm trigger "--retry-failed" option, which is replaced since quite
306 a while by "--type=failed" is removed.
308 The failed tracking was not working at all for a few releases. The RUN
309 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
310 default is not to track any failing RUN executions.
312 New keymaps, new modem, hid2hci updated.
316 Fix possible crash in udevd when worker processes are busy, rules are
317 changed at the same time, and workers get killed to reload the rules.
323 Properties set with ENV{.FOO}="bar" are marked private by starting the
324 name with a '.'. They will not be stored in the database, and not be
325 exported with the event.
327 Firmware files are looked up in:
328 /lib/firmware/updates/$(uname -r)
329 /lib/firmware/updates
330 /lib/firmware/$(uname -r)
334 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
335 ata_id, instead of scsi_id, is the default tool now for ATA devices.
341 The configure options have changed because another library needs to be
342 installed in a different location. Instead of exec_prefix and udev_prefix,
343 libdir, rootlibdir and libexecdir are used. The Details are explained in
346 Event processes now get re-used after they handled an event. This reduces
347 the number of forks and the pressure on the CPU significantly, because
348 cloned event processes no longer cause page faults in the main daemon.
349 After the events have settled, a few worker processes stay around for
350 future events, all others get cleaned up.
352 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
353 Also inotify support is mandatory now to run udev.
355 The format of the queue exported by the udev damon has changed. There is
356 no longer a /dev/.udev/queue/ directory. The current event queue can be
357 accessed with udevadm settle and libudedv.
359 Libudev does not have the unstable API header anymore. From now on,
360 incompatible changes will be handled by bumping the library major version.
362 To build udev from the git tree gtk-doc is needed now. The tarballs will
363 build without it and contain the pre-built documentation. An online copy
365 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
367 The tools from the udev-extras repository have been merged into the main
368 udev repository. Some of the extras have larger external dependencies, and
369 they can be disabled with the configure switch --disable-extras.
375 The program vol_id and the library libvolume_id are removed from the
376 repository. Libvolume_id is merged with libblkid from the util-linux-ng
377 package. Persistent disk links for label and uuid depend on the
378 util-linux-ng version (2.15) of blkid now. Older versions of blkid
379 can not be used with udev.
381 Libudev allows to subscribe to udev events. To prevent unwanted messages
382 to be delivered, and waking up the subscribing process, a filter can be
383 installed, to drop messages inside a kernel socket filter. The filters
384 match on the <subsytem>:<devtype> properties of the device.
385 This is part of the ongoing effort to replace HAL, and switch current
386 users over to directly use libudev.
387 Libudev is still marked as experimental, and its interface might
388 eventually change if needed, but no major changes of the currently exported
389 interface are expected anymore, and a first stable release should happen
392 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
393 is not supported since while and udevd will log an error message at
394 startup. It should still be able to boot-up, but advanced rules and system
395 services which depend on the information not available in the old sysfs
396 format will fail to work correctly.
398 DVB device naming is supplied by the kernel now. In case older kernels
399 need to be supported, the old shell script should be added to a compat
406 The processed udev events get send back to the netlink socket. Libudev
407 provides access to these events. This is work-in-progress, to replace
408 the DeviceKit daemon functionality directly with libudev. There are
409 upcoming kernel changes to allow non-root users to subcribe to these
416 "udevadm settle" now optionally accepts a range of events to wait for,
417 instead of waiting for "all" events.
423 The installed watch for block device metadata changes is now removed
424 during event hadling, because some (broken) tools may be called from udev
425 rules and (wrongly) open the device with write access. After the finished
426 event handling the watch is restored.
432 Device nodes can be watched for changes with inotify with OPTIONS="watch".
433 If closed after being opened for writing, a "change" uevent will occur.
434 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
440 The udevadm test command has no longer a --force option, nodes and symlinks
441 are always updated with a test run now.
443 The udevd daemon can be started with --resolve-names=never to avoid all user
444 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
445 lookup user and groups every time events are handled.
451 We are currently merging the Ubuntu rules in the udev default rules,
452 and get one step closer to provide a common Linux /dev setup, regarding
453 device names, symlinks, and default device permissions. On udev startup,
454 we now expect the following groups to be resolvable to their ids with
456 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
457 LDAP setups need to make sure, that these groups are always resolvable at
458 bootup, with only the rootfs mounted, and without network access available.
460 Some systems may need to add some new, currently not used groups, or need
461 to add some users to new groups, but the cost of this change is minimal,
462 compared to the pain the current, rather random, differences between the
463 various distributions cause for upstream projects and third-party vendors.
465 In general, "normal" users who log into a machine should never be a member
466 of any such group, but the device-access should be managed by dynamic ACLs,
467 which get added and removed for the specific users on login/logout and
468 session activity/inactivity. These groups are only provided for custom setups,
469 and mainly system services, to allow proper privilege separation.
470 A video-streaming daemon uid would be a member of "audio" and "video", to get
471 access to the sound and video devices, but no "normal" user should ever belong
472 to the "audio" group, because he could listen to the built-in microphone with
473 any ssh-session established from the other side of the world.
475 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
476 which do not depend on the kernel device name. As usual, unique
477 devices - only a single one per product connected, or a real
478 USB serial number in the device - are always found with the same
479 name in the by-id/ directory.
480 Completely identical devices may overwrite their names in by-id/
481 and can only be found reliably in the by-path/ directory. Devices
482 specified by by-path/ must not change their connection, like the
483 USB port number they are plugged in, to keep their name.
485 To support some advanced features, Linux 2.6.22 is the oldest supported
486 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
487 supported. Older kernels should still work, and devices nodes should be
488 reliably created, but some rules and libudev will not work correctly because
489 the old kernels do not provide the expected information or interfaces.
495 Fix for a possible segfault while swapping network interface names in udev
502 The group "video" is part of the default rules now.
506 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
507 block devices in some cases. No common distro uses this option anymore,
508 and we do not get enough testing for this and recent udev versions. If
509 this option is not needed to run some old distro with a new kernel,
510 it should be disabled in the kernel config.
512 Bugfix for the $links substitution variable, which may crash if no links
513 are created. This should not happen in usual setups because we always
514 create /dev/{block,char}/ links.
516 The strings of the parsed rules, which are kept in memory, no longer
517 contain duplicate entries, or duplicate tails of strings. This, and the
518 new rules parsing/matching code reduces the total in-memory size of
519 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
522 The export of DEVTYPE=disk/partition got removed from the default
523 rules. This value is available from the kernel. The pnp shell script
524 modprobe hack is removed from the default rules. ACPI devices have _proper_
525 modalias support and take care of the same functionality.
526 Installations which support old kernels, but install current default
527 udev rules may want to add that to the compat rules file.
529 Libvolume_id now always probes for all known filesystems, and does not
530 stop at the first match. Some filesystems are marked as "exclusive probe",
531 and if any other filesytem type matches at the same time, libvolume_id
532 will, by default, not return any probing result. This is intended to prevent
533 mis-detection with conflicting left-over signatures found from earlier
534 file system formats. That way, we no longer depend on the probe-order
535 in case of multiple competing signatures. In some setups the kernel allows
536 to mount a volume with just the old filesystem signature still in place.
537 This may damage the new filesystem and cause data-loss, just by mounting
538 it. Because volume_id can not decide which one the correct signature is,
539 the wrong signatures need to be removed manually from the volume, or the
540 volume needs to be reformatted, to enable filesystem detection and possible
545 Fix segfault if compiled without optimization and dbg() does not get
546 compiled out and uses variables which are not available.
550 Bugfixes. (And maybe new bugs. :))
552 The rule matching engine got converted from a rule list to a token
553 array which reduced the in-memory rules representation of a full
554 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
555 Limits like 5 ENV and ATTR matches, and one single instance for most
556 other keys per rule are gone.
558 The NAME assignment is no longer special cased. If later rules assign
559 a NAME value again, the former value will be overwritten. As usual
560 for most other keys, the NAME value can be protected by doing a final
561 assignment with NAME:="<value>".
563 All udev code now uses libudev, which is also exported. The library
564 is still under development, marked as experimental, and its interface
565 may change as long as the DeviceKit integration is not finished.
567 Many thanks to Alan Jenkins for his continuous help, and finding and
568 optimizing some of the computing expensive parts.
574 Kernel devices and device nodes are connected now by reverse indizes in
575 /sys and /dev. A device number retrieved by a stat() or similar, the
576 kernel device directory can be found by looking up:
577 /sys/dev/{block,char}/<maj>:<min>
578 and the device node of the same device by looking up:
579 /dev/{block,char}/<maj>:<min>
583 Fix recently introduced bug, which caused a compilation without large
584 file support, where vol_id does not recognize raid signatures at the end
587 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
588 Seems some kernel versions prevent the creation of the ieee-* links,
589 so people used the scsi-* link which disappeared now.
591 More libudev work. Almost all udevadm functionality comes from libudev
594 udevadm trigger has a new option --type, which allows to trigger events
595 for "devices", for "subsystems", or "failed" devices. The old option
596 --retry-failed" still works, but is no longer mentioned in the man page.
602 The udevadm info --device-id-of-file= output has changed to use
603 the obvious format. Possible current users should use the --export
604 option which is not affected.
606 The old udev commands symlinks to udevadm are not installed, if
607 these symlinks are used, a warning is printed.
613 Optical drive's media is no longer probed for raid signatures,
614 reading the end of the device causes some devices to malfunction.
615 Also the offset of the last session found is used now to probe
618 The volume_id library got a major version number update to 1,
619 some deprecated functions are removed.
621 A shared library "libudev" gets installed now to provide access
622 to udev device information. DeviceKit, the successor of HAL, will
623 need this library to access the udev database and search sysfs for
625 The library is currently in an experimental state, also the API is
626 expected to change, as long as the DeviceKit integration is not
631 We use ./configure now. See INSTALL for details. Current
634 "/usr" - prefix for man pages, include files
636 "" - the root filesystem, prefix for libs and binaries
640 "lib" - directory name for libraries, not a path name
641 multilib 64bit systems may use "lib64" instead of "lib"
643 compile-in verbose debug messages
645 disable all logging and compile-out all log strings
647 link against SELInux libraries, to set the expected context
650 In the default rules, the group "disk" gets permissions 0660 instead
651 of 0640. One small step closer to unify distro rules. Some day, all
652 distros hopefully end up with the same set of rules.
654 No symlinks to udevadm are installed anymore, if they are still needed,
655 they should be provided by the package.
661 Default udev rules, which are not supposed to be edited by the user, should
662 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
663 the udev package and will be replaced with an update. Udev will pick up rule
665 /lib/udev/rules.d/ - default installed rules
666 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
667 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
668 It does not matter in which directory a rule file lives, all files are sorted
671 To help creating /dev/root, we have now:
672 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
675 In case the current --device-id-of-file is already used, please switch to
676 the --export format version, it saves the output parsing and the old
677 format will be changed to use ':' as a separator, like the format in the
682 Fix cdrom_id to properly recognize blank media.
688 Tape drive id-data is queried from /dev/bsg/* instead of the tape
689 nodes. This avoids rewinding tapes on open().
695 The symlinks udevcontrol and udevtrigger are no longer installed by
698 The scsi_id program does not depend on sysfs anymore. It can speak
699 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
700 data, which should solve some old problems with tape devices, where
701 we better do not open all tape device nodes to identify the device.
707 The cdrom_id program is replaced by an advanced version, which can
708 detect most common device types, and also properties of the inserted
709 media. This is part of moving some basic functionality from HAL into
710 udev (and the kernel).
716 The last WAIT_FOR_SYSFS rule is removed from the default rules.
718 The symlinks to udevadm for the debugging tools: udevmonitor and
719 udevtest are no longer created.
721 The symlinks to the udevadm man page for the old tool names are
724 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
725 should be prefixed with '@' to indicate that the path is not a
736 Udevstart is removed from the tree, it did not get installed for
737 a long time now, and is long replaced by trigger and settle.
743 All udev tools are merged into a single binary called udevadm.
744 The old names of the tools are built-in commands in udevadm now.
745 Symlinks to udevadm, with the names of the old tools, provide
746 the same functionality as the standalone tools. There is also
747 only a single udevadm.8 man page left for all tools.
749 Tools like mkinitramfs should be checked, if they need to include
750 udevadm in the list of files.
760 The etc/udev/rules.d/ directory now contains a default set of basic
761 udev rules. This initial version is the result of a rules file merge
762 of Fedora and openSUSE. For these both distros only a few specific
763 rules are left in their own file, named after the distro. Rules which
764 are optionally installed, because they are only valid for a specific
765 architecture, or rules for subsystems which are not always used are
766 in etc/udev/packages/.
772 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
773 actions by dynamically created rules.
775 SYMLINK=="<value>" matches agains the entries in the list of
776 currently defined symlinks. The links are not created in the
777 filesystem at that point in time, but the values can be matched.
779 RUN{ignore_error}+="<program>" will ignore any exit code from the
780 program and not record as a failed event.
786 Final merge of patches/features from the Ubuntu package.
792 Control characters in filesystem label strings are no longer silenty
793 removed, but hex-encoded, to be able to uniquely identify the device
794 by its symlink in /dev/disk/by-label/.
795 If libvolume_id is used by mount(8), LABEL= will work as expected,
796 if slashes or other characters are used in the label string.
798 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
799 can be specified now. The TEST key accepts an optional mode mask
800 TEST{0100}=="<is executable file>".
802 Scsi_id now supports a mode without expecting scsi-specific sysfs
803 entries to allow the extraction of cciss-device persistent properties.
809 In the future, we may see uuid's which are just simple character
810 strings (see the DDF Raid Specification). For that reason vol_id now
811 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
812 the creation of symlinks, the *_SAFE values ensure, that no control
813 or whitespace characters are used in the filename.
815 Possible users of libvolume_id, please use the volume_id_get_* functions.
816 The public struct will go away in a future release of the library.
822 Removal of useless extras/eventrecorder.sh.
832 The directory multiplexer for dev.d/ and hotplug.d are finally removed
833 from the udev package.
839 Symlinks can have priorities now, the priority is assigned to the device
840 and specified with OPTIONS="link_priority=100". Devices with higher
841 priorities overwrite the symlinks of devices with lower priorities.
842 If the device that currently owns the link, goes away, the symlink
843 will be removed, and recreated, pointing to the next device with the
844 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
845 more reliable, if multiple devices contain the same metadata and overwrite
848 The dasd_id program is removed from the udev tree, and dasdinfo, with the
849 needed rules, are part of the s390-tools now.
851 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
852 we may get the scsi sysfs mess fixed some day, and this will only catch
853 the devices we are looking for.
855 USB serial numbers for storage devices have the target:lun now appended,
856 to make it possibble to distinguish broken multi-lun devices with all
857 the same SCSI identifiers.
859 Note: The extra "run_directory" which searches and executes stuff in
860 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
861 with the next release. Make sure, that you don't use it anymore, or
862 provides your own implementation of that inefficient stuff.
863 We are tired of reports about a "slow udev", because these directories
864 contain stuff, that runs with _every_ event, instead of using rules,
865 that run programs only for the matching events.
875 DRIVER== will match only for devices that actually have a real
876 driver. DRIVERS== must be used, if parent devices should be
877 included in the match.
879 Libvolume_id's "linux_raid" detection needed another fix.
887 Add additional check to volume_id detection of via_raid, cause
888 some company decided to put a matching pattern all over the empty
889 storage area of their music players.
893 Fix path_id for SAS devices.
897 The udev daemon can be started with --debug-trace now, which will
898 execute all events serialized to get a chance to catch a possible
899 action that crashes the box.
901 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
902 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
903 are excluded from the warning. Referencing parent attributes directly
904 may break when something in the kernel driver model changes. Udev will
905 just find the attribute by walking up the parent chain.
907 Udevtrigger now sorts the list of devices depending on the device
908 dependency, so a "usb" device is triggered after the parent "pci"
913 Revert persistent-storage ata-serial '_' '-' replacement.
919 Udevtrigger can now filter the list of devices to be triggered. Matches
920 for subsystems or sysfs attributes can be specified.
922 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
923 zero-sized files to avoid pointing to /sys and confuse broken tools which
924 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
927 The rules and scripts to create udev rules for persistent network
928 devices and optical drives are in the extras/rules_generator directory
929 now. If you use something similar, please consider replacing your own
930 version with this, to share the support effort. The rule_generator
931 installs its own rules into /etc/udev/rules.d.
933 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
934 the rule_generator depends on cdrom_id to be called in an earlier rule.
940 Renaming of some key names (the old names still work):
941 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
942 (The behavior of the key DRIVER will change soon in one of the next
943 releases, to match only the event device, please switch to DRIVERS
944 instead. If DRIVER is used, it will behave like DRIVERS, but an error
946 With the new key names, we have a more consistent and simpler scheme.
947 We can match the properties of the event device only, with: KERNEL,
948 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
949 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
950 longer mentioned in the man page and should be switched in the rule
953 ATTR{file}="value" can be used now, to write to a sysfs file of the
954 event device. Instead of:
955 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
957 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
959 All the PHYSDEV* keys are deprecated and will be removed from a
961 PHYDEVPATH - is the path of a parent device and should not be
963 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
964 matched with SUBSYSTEMS==
965 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
966 Newer kernels will have DRIVER in the environment,
967 for older kernels udev puts in. Class device will
968 no longer carry this property of a parent and
969 DRIVERS== can be used to match such a parent value.
970 Note that ENV{DRIVER} is only available for a few bus devices, where
971 the driver is already bound at device event time. On coldplug, the
972 events for a lot devices are already bound to a driver, and they will have
973 that value set. But on hotplug, at the time the kernel creates the device,
974 it can't know what driver may claim the device after that, therefore
975 in most cases it will be empty.
977 Failed events should now be re-triggered with:
978 udevtrigger --retry-failed.
979 Please switch to this command, so we keep the details of the /dev/.udev/failed/
980 files private to the udev tools. We may need to switch the current symlink
981 target, cause some obviously broken tools try to scan all files in /dev
982 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
983 million times. This takes ages on slow boxes.
985 The udevinfo attribute walk (-a) now works with giving a device node
986 name (-n) instead of a devpath (-p). The query now always works, also when
987 no database file was created by udev.
989 The built-in /etc/passwd /etc/group parser is removed, we always depend on
990 getpwnam() and getgrnam() now. One of the next releases will depend on
991 fnmatch() and may use getopt_long().
995 Bugfixes and small improvements.
999 Fix path_id for recent kernels.
1005 Added support for swapping network interface names, by temporarily
1006 renaming the device and wait for the target name to become free.
1010 The built-in MODALIAS key and substitution is removed.
1014 The binary firmware helper is replaced by the usual simple
1015 shell script. Udevsend is removed from the tree.
1023 Some more keys require the correct use of '==' and '=' depending
1024 on the kind of operation beeing an assignment or a match. Rules
1025 with invalid operations are skipped and logged to syslog. Please
1026 test with udevtest if the parsing of your rules throws errors and
1027 fix possibly broken rules.
1031 Provide "udevsettle" to wait for all current udev events to finish.
1032 It also watches the current kernel netlink queue by comparing the
1033 even sequence number to make sure that there are no current pending
1034 events that have not already arrived in the daemon.
1038 Fix rule to skip persistent rules for removable IDE devices, which
1039 also skipped optical IDE drives.
1041 All *_id program are installed in /lib/udev/ by default now.
1043 No binary is stripped anymore as this should be done in the
1044 packaging process and not at build time.
1046 libvolume_id is provided as a shared library now and vol_id is
1047 linked against it. Also one of the next HAL versions will require
1048 this library, and the HAL build process will also require the
1049 header file to be installed. The copy of the same code in HAL will
1050 be removed to have only a single copy left on the system.
1054 Add persistent links for SCSI tapes. The rules file is renamed
1055 to 60-persistent-storage.rules.
1057 Create persistent path for usb devices. Can be used for all sorts
1058 of devices that can't be distinguished by other properties like
1059 multiple identical keyboards and mice connected to the same box.
1061 Provide "udevtrigger" program to request events on coldplug. The
1062 shell script is much too slow with thousends of devices.
1066 Fix persistent disk rules to exclude removable IDE drives.
1068 Warn if %e, $modalias or MODALIAS is used.
1072 Fix queue export, which wasn't correct for subsequent add/remove
1073 events for the same device.
1077 Fix cramfs detection on big endian.
1079 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1084 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1085 attributes were only checked at the parent device that matched the
1086 by BUS requested subsystem. Fix it to also look at the device we
1087 received the event for.
1089 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1094 Fix a bug where NAME="" would prevent RUN from beeing executed.
1096 RUN="/bin/program" does not longer automatically add the subsystem
1097 as the first parameter. This is from the days of /sbin/hotplug
1098 which is dead now and it's just confusing to need to add a space at
1099 the end of the program name to prevent this.
1100 If you use rules that need the subsystem as the first parameter,
1101 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1102 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1106 The udev man page has moved to udev(7) as it does not describe a command
1107 anymore. The programs udev, udevstart and udevsend are no longer installed
1108 by default and must be copied manually, if they should be installed or
1109 included in a package.
1111 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1112 the ignore rule was applied.
1114 More preparation for future sysfs changes. usb_id and scsi_id no longer
1115 depend on a magic order of devices in the /devices chain. Specific devices
1116 should be requested by their subsytem.
1118 This will always find the scsi parent device without depending on a specific
1120 dev = sysfs_device_get(devpath);
1121 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1123 The "device" link in the current sysfs layout will be automatically
1124 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1125 parent in the devpath. If a device is requested by it's symlink, like all
1126 class devices in the new sysfs layout will look like, it gets automatically
1127 resolved and substituted with the real devpath and not the symlink path.
1130 A similar logic must be applied to _all_ sysfs users, including
1131 scripts, that search along parent devices in sysfs. The explicit use of
1132 the "device" link must be avoided. With the future sysfs layout all
1133 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1134 back to the "class" or the "bus". The layout of the parent devices in
1135 /devices is not necessarily expected to be stable across kernel releases and
1136 searching for parents by their subsystem should make sysfs users tolerant
1137 for changed parent chains.
1141 Prepare udev to work with the experimental kernel patch, that moves
1142 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1144 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1145 moving the class devices to /sys/devices.
1147 Thanks again to Marco for help finding a hopefully nice compromise
1148 to make %b simpler and working again.
1152 Complete removal of libsysfs, replaced by simple helper functions
1153 which are much simpler and a bit faster. The udev daemon operatesentirely
1154 on event parameters and does not use sysfs for simple rules anymore.
1155 Please report any new bugs/problems, that may be caused by this big
1156 change. They will be fixed immediately.
1158 The enumeration format character '%e' is deprecated and will be
1159 removed sometimes from a future udev version. It never worked correctly
1160 outside of udevstart, so we can't use it with the new parallel
1161 coldplug. A simple enumeration is as useless as the devfs naming
1162 scheme, just get rid of both if you still use it.
1164 MODALIAS and $modalias is not needed and will be removed from one of
1165 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1166 the sysfs "modalias" value.
1168 Thanks a lot to Marco for all his help on finding and fixing bugs.
1172 Let scsi_id request libata drive serial numbers from page 0x80.
1174 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1175 added /dev/disk/by-name/* for device mapper device names.
1177 Removed %e from the man page. It never worked reliably outside
1178 of udevstart and udevstart is no longer recommended to use.
1182 Symlinks are now exported to the event environment. Hopefully it's no
1183 longer needed to run udevinfo from an event process, like it was
1184 mentioned on the hotplug list:
1185 UDEV [1134776873.702967] add@/block/sdb
1188 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1192 Fix a problem if udevsend is used as the hotplug handler and tries to use
1193 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1194 and this kind of problems will hopefully go away soon.
1198 All built-in logic to work around bad sysfs timing is removed with this
1199 version. The need to wait for sysfs files is almost fixed with a kernel
1200 version that doesn't work with this udev version anyway. Until we fix
1201 the timing of the "bus" link creation, the former integrated logic should
1202 be emulated by a rule placed before all other rules:
1203 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1205 The option "udev_db" does no longer exist. All udev state will be in
1206 /$udev_root/.udev/ now, there is no longer an option to set this
1208 If the init script or something else used this value, just depend on
1209 this hardcoded path. But remember _all_content_ of this directory is
1210 still private to udev and can change at any time.
1212 Default location for rule sripts and helper programs is now: /lib/udev/.
1213 Everything that is not useful on the commandline should go into this
1214 directory. Some of the helpers in the extras folder are installed there
1215 now. The rules need to be changed, to find the helpers there.
1217 Also /lib/udev/devices is recommended as a directory where packages or
1218 the user can place real device nodes, which get copied over to /dev at
1219 every boot. This should replace the various solutions with custom config
1222 Udevsend does no longer start the udev daemon. This must be done with
1223 the init script that prepares /dev on tmpfs and creates the initial nodes,
1224 before starting the daemon.
1228 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1231 The copy of klibc is removed. A systemwide installed version of klibc
1232 should be used to build a klibc udev now.
1236 NAME="" will not create any nodes, but execute RUN keys. To completely
1237 ignore an event the OPTION "ignore_device" should be used.
1239 After removal of the reorder queue, events with a TIMEOUT can be executed
1240 without any queuing now.
1244 Fixed bug in udevd, if inotify is not available. We depend on netlink
1245 uevents now, kernels without that event source will not work with that
1246 version of udev anymore.
1250 The rule parsing happens now in the daemon once at startup, all udev
1251 event processes inherit the already parsed rules from the daemon.
1252 It is shipped with SUSE10.0 and reduces heavily the system load at
1253 startup. The option to save precompiled rules and let the udev process
1254 pick the them up is removed, as it's no longer needed.
1256 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1257 device. Libsysfs is changed to "translate" the requested link into the
1258 real device path, as it would happen with the hotplug event. Otherwise
1259 device removal and the udev database will not work.
1261 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1264 A few improvements for vol_id, the filesytem probing code.
1268 Fix a stupid typo in extras/run_directory for "make install".
1270 scsi_id creates the temporary devnode now in /dev for usage with a
1271 non-writable /tmp directory.
1273 The uevent kernel socket buffer can carry app. 50.000 events now,
1274 let's see who can break this again. :)
1276 The upcoming kernel will have a new input driver core integration.
1277 Some class devices are now symlinks to the real device. libsysfs
1278 needs a fix for this to work correctly. Udevstart of older udev
1279 versions will _not_ create these devices!
1283 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1288 A bunch of mostly trivial bugfixes. From now on no node name or
1289 symlink name can contain any character than plain whitelisted ascii
1290 characters or validated utf8 byte-streams. This is needed for the
1291 /dev/disk/by-label/* links, because we import untrusted data and
1292 export it to the filesystem.
1296 More bugfixes. If udevd was started from the kernel, we don't
1297 have stdin/stdout/stderr, which broke the forked tools in some
1302 Bugfix. udevstart event ordering was broken for a long time.
1303 The new run_program() uncovered it, because /dev/null was not
1304 available while we try to run external programs.
1305 Now udevstart should create it before we run anything.
1309 Minor bugfixes and some distro rules updates. If you don't have the
1310 persistent disk rules in /dev/disk/by-*/* on your distro, just
1311 grab it from here. :)
1315 We can use socket communication now to pass events from udev to
1317 RUN+="socket:/org/freedesktop/hal/udev_event"
1318 will pass the whole udev event to the HAL daemon without the need
1319 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1323 Mostly bugfixes and see ChangeLog.
1325 The test for the existence of an environment value should be
1327 ENV{KEY}=="*" to ENV{KEY}=="?*"
1328 because "*" will not fail anymore, if the key does not exist or
1333 Bugfixes and a few tweaks described in the ChangeLog.
1337 Mostly a Bugfix release.
1339 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1340 timing with custom rules.
1344 We changed the internal rule storage format. Our large rule files took
1345 2 MB of RAM, with the change we are down to 99kB.
1347 If the device-node has been created with default name and no symlink or
1348 options are to remenber, it is not longer stored in the udevdb. HAL will
1349 need to be updated to work correctly with that change.
1351 To overrride optimization flags, OPTFLAGS may be used now.
1359 Major changes happened with this release. The goal is to take over the
1360 complete kernel-event handling and provide a more efficient way to dispatch
1361 kernel events. Replacing most of the current shell script logic and the
1362 kernel forked helper with a netlink-daemon and a rule-based event handling.
1364 o udevd listens to netlink events now. The first valid netlink event
1365 will make udevd ignore any message from udevsend that contains a
1366 SEQNUM, to avoid duplicate events. The forked events can be disabled
1368 echo "" > /proc/sys/kernel/hotplug
1369 For full support, the broken input-subsytem needs to be fixed, not to
1370 bypass the driver core.
1372 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1373 removed from udev itself and must be emulated by calling small
1374 helper binaries provided in the extras folder:
1375 make EXTRAS=extras/run_directory/
1376 will build udev_run_devd and udev_run_hotplugd, which can be called
1377 from a rule if needed:
1378 RUN+="/sbin/udev_run_hotplugd"
1379 The recommended way to handle this is to convert all the calls from
1380 the directories to explicit udev rules and get completely rid of the
1381 multiplexing. (To catch a ttyUSB event, you now no longer need to
1382 fork and exit 300 tty script instances you are not interested in, it
1383 is just one rule that matches exactly the device.)
1385 o udev handles now _all_ events not just events for class and block
1386 devices, this way it is possible to control the complete event
1387 behavior with udev rules. Especially useful for rules like:
1388 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1390 o As used in the modalias rule, udev supports now textual
1391 substitution placeholder along with the usual format chars. This
1392 needs to be documented, for now it's only visible in udev_rules_parse.c.
1394 o The rule keys support now more operations. This is documented in the
1395 man page. It is possible to add values to list-keys like the SYMLINK
1396 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1397 Also "final"-assignments are supported by using KEY:="value", which will
1398 prevent changing the key by any later rule.
1400 o kernel 2.6.12 has the "detached_state" attribute removed from
1401 sysfs, which was used to recognize sysfs population. We switched that
1402 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1403 Running this udev version on older kernels may cause a short delay for
1406 o To provide infrastructure for persistent device naming, the id programs:
1407 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1408 to export the probed data in environment key format:
1409 pim:~ # /sbin/ata_id --export /dev/hda
1410 ID_MODEL=HTS726060M9AT00
1411 ID_SERIAL=MRH401M4G6UM9B
1412 ID_REVISION=MH4OA6BA
1414 The following rules:
1415 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1416 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1419 kay@pim:~> tree /dev/disk
1422 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1423 | `-- IBM-Memory_Key -> ../../sda
1425 | |-- swap -> ../../hda1
1426 | |-- date -> ../../sda1
1427 | `-- home -> ../../hda3
1429 |-- 2E08712B0870F2E7 -> ../../hda3
1430 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1431 |-- E845-7A89 -> ../../sda1
1432 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1434 The IMPORT= operation will import these keys in the environment and make
1435 it available for later PROGRAM= and RUN= executed programs. The keys are
1436 also stored in the udevdb and can be queried from there with one of the
1439 o A few binaries are silently added to the repository, which can be used
1440 to replay kernel events from initramfs instead of using coldplug. udevd
1441 can be instructed now to queue-up events while the stored events from
1442 initramfs are filled into the udevd-queue. This code is still under
1443 development and there is no documentation now besides the code itself.
1444 The additional binaries get compiled, but are not installed by default.
1446 o There is also a temporary fix for a performance problem where too many
1447 events happen in parallel and every event needs to parse the rules.
1448 udev can now read precompiled rules stored on disk. This is likely to be
1449 replaced by a more elegant solution in a future udev version.
1453 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1454 Fix for libsysfs not to expect this file was added.
1458 All rules are applied now, but only the first matching rule with a NAME-key
1459 will be applied. All later rules with NAME-key are completely ignored. This
1460 way system supplied symlinks or permissions gets applied to user-defined
1464 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1465 to some rules, to keep the old behavior.
1467 The rules are read on "remove"-events too. That makes is possible to match
1468 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1469 instruct udev to ignore an event (OPTIONS="ignore_device").
1470 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1472 The new RUN-key supports rule-based execution of programs after device-node
1473 handling. This is meant as a general replacement for the dev.d/-directories
1474 to give fine grained control over the execution of programs.
1476 The %s{}-sysfs format char replacement values are searched at any of the
1477 devices in the device chain now, not only at the class-device.
1479 We support log priority levels now. The value udev_log in udev.conf is used
1480 to determine what is printed to syslog. This makes it possible to
1481 run a version with compiled-in debug messages in a production environment
1482 which is sometimes needed to find a bug.
1483 It is still possible to supress the inclusion of _any_ syslog usage with
1484 USE_LOG=false to create the smallest possible binaries if needed.
1485 The configured udev_log value can be overridden with the environment variable
1490 Possible use of a system-wide klibc:
1491 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1492 will link against an external klibc and our own version will be ignored.
1496 We support an unlimited count of symlinks now.
1498 If USE_STATIC=true is passed to a glibc build, we link statically and use
1499 a built-in userdb parser to resolve user and group names.
1501 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1502 we walk up the chain of physical devices to find a match.
1504 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1505 easy to skip certain attribute matches without composing rules with weird
1506 character class negations like:
1507 KERNEL="[!s][!c][!d]*"
1508 this can now be replaced with:
1510 The current simple '=' is still supported, and should work as it does today,
1511 but existing rules should be converted if possible, to be better readable.
1513 We have new ENV{}== key now, to match against a maximum of 5 environment
1516 udevstart is its own binary again, because we don't need co carry this araound
1517 with every forked event.