5 warning if /run is not writable
9 udevadm info --cleanup-db
10 if used, OPTIONS+="db_persist" needed for LVM
12 systemd netlink socket activation
13 stop socket or mask on rpm update
16 hard event timeout now. hanging programs will be killed
22 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
23 /run mountpoint is supposed to be a tmpfs mounted during early boot,
24 available and writable to for all tools at any time during bootup,
25 it replaces /var/run/, which should become a symlink some day.
27 If /run does not exist, or is not writable, udev will fall back using
30 On systemd systems with initramfs and LVM used, packagers must
31 make sure, that the systemd and initramfs versions match. The initramfs
32 needs to create the /run mountpoint for udev to store the data, and
33 mount this tmpfs to /run in the rootfs, so the that the udev database
34 is preserved for the udev version started in the rootfs.
36 The command 'udevadm info --convert-db' is gone. The udev daemon
37 itself, at startup, converts any old database version if necessary.
39 The systemd services files have been reorganized. The udev control
40 socket is bound by systemd and passed to the started udev daemon.
41 The udev-settle.service is no longer active by default. Services which
42 can not handle hotplug setups properly need to actively pull it in, to
43 act like a barrier. Alternatively the settle service can be unconditionally
44 'systemctl'enabled, and act like a barrier for basic.target.
46 The fstab_import callout is no longer built or installed. Udev
47 should not be used to mount, does not watch changes to fstab, and
48 should not mirror fstab values in the udev database.
54 New and updated keymaps.
60 The udev database has changed, After installation of a new udev
61 version, 'udevadm info --convert-db' should be called, to let the new
62 udev/libudev version read the already stored data.
64 udevadm now supports quoting of property values, and prefixing of
66 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
74 udev_device_get_is_initialized()
75 udev_enumerate_add_match_is_initialized()
76 to be able to skip devices the kernel has created , but udev has
80 udev_device_get_usec_since_initialized()
81 to retrieve the "age" of a udev device record.
83 GUdev supports a more generic GUdevEnumerator class, udev TAG
84 handling, device initialization and timestamp now.
86 The counterpart of /sys/dev/{char,block}/$major:$minor,
87 /dev/{char,block}/$major:$minor symlinks are now unconditionally
88 created, even when no rule files exist.
90 New and updated keymaps.
96 GUdev moved from /usr to /.
106 Persistent network naming rules are disabled inside of Qemu/KVM now.
108 New and updated keymaps.
110 Udev gets unconditionally enabled on systemd installations now. There
111 is no longer the need to to run 'systemctl enable udev.service'.
125 New and fixed keymaps.
127 Install systemd service files if applicable.
133 All distribution specific rules are removed from the udev source tree,
134 most of them are no longer needed. The Gentoo rules which allow to support
135 older kernel versions, which are not covered by the default rules anymore
136 has moved to rules/misc/30-kernel-compat.rules.
142 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
143 was removed from udevd.
145 Udevd now checks the kernel commandline for the following variables:
146 udev.log-priority=<syslog priority>
147 udev.children-max=<maximum number of workers>
148 udev.exec-delay=<seconds to delay the execution of RUN=>
149 to help debuging coldplug setups where the loading of a kernel
150 module crashes the system.
152 The subdirectory in the source tree rules/packages has been renamed to
153 rules/arch, anc contains only architecture specific rules now.
163 Now the udev daemon itself, does on startup:
164 - copy the content of /lib/udev/devices to /dev
165 - create the standard symlinks like /dev/std{in,out,err},
166 /dev/core, /dev/fd, ...
167 - use static node information provided by kernel modules
168 and creates these nodes to allow module on-demand loading
169 - possibly apply permissions to all ststic nodes from udev
170 rules which are annotated to match a static node
172 The default mode for a device node is 0600 now to match the kernel
173 created devtmpfs defaults. If GROUP= is specified and no MODE= is
174 given the default will be 0660.
180 Udev now gradually starts to pass control over the primary device nodes
181 and their names to the kernel, and will in the end only manage the
182 permissions of the node, and possibly create additional symlinks.
183 As a first step NAME="" will be ignored, and NAME= setings with names
184 other than the kernel provided name will result in a logged warning.
185 Kernels that don't provide device names, or devtmpfs is not used, will
186 still work as they did before, but it is strongly recommended to use
187 only the same names for the primary device node as the recent kernel
188 provides for all devices.
192 Fix broken firmware loader search path.
198 "udevadm trigger" defaults to "change" events now instead of "add"
199 events. The "udev boot script" might need to add "--action=add" to
200 the trigger command if not already there, in case the initial coldplug
201 events are expected as "add" events.
203 The option "all_partitons" was removed from udev. This should not be
204 needed for usual hardware. Udev can not safely make assumptions
205 about non-existing partition major/minor numbers, and therefore no
206 longer provide this unreliable and unsafe option.
208 The option "ignore_remove" was removed from udev. With devtmpfs
209 udev passed control over device nodes to the kernel. This option
210 should not be needed, or can not work as advertised. Neither
211 udev nor the kernel will remove device nodes which are copied from
212 the /lib/udev/devices/ directory.
214 All "add|change" matches are replaced by "!remove" in the rules and
215 in the udev logic. All types of events will update possible symlinks
216 and permissions, only "remove" is handled special now.
218 The modem modeswitch extra was removed and the external usb_modeswitch
219 program should be used instead.
221 New and fixed keymaps.
231 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
232 depend on the current sysfs layout and the information not available in the
233 deprecated layout. All remaining support for the deprecated sysfs layout is
238 Fix for a possible endless loop in the new input_id program.
244 The option "ignore_device" does no longer exist. There is no way to
245 ignore an event, as libudev events can not be suppressed by rules.
246 It only prevented RUN keys from being executed, which results in an
247 inconsistent behavior in current setups.
249 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
250 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
253 The support for the deprecated IDE devices has been removed from the
254 default set of rules. Distros who still care about non-libata drivers
255 need to add the rules to the compat rules file.
257 The ID_CLASS property on input devices has been replaced by the more accurate
258 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
259 determined by the new "input_id" prober now. Some devices, such as touchpads,
260 can have several classes. So if you previously had custom udev rules which e. g.
261 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
262 ENV{ID_INPUT_KEYBOARD}=="?*".
268 To support DEVPATH strings larger than the maximum file name length, the
269 private udev database format has changed. If some software still reads the
270 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
271 Please do not port anything to the new format again, everything in /dev/.udev
272 is and always was private to udev, and may and will change any time without
275 Multiple devices claiming the same names in /dev are limited to symlinks
276 only now. Mixing identical symlink names and node names is not supported.
277 This reduces the amount of data in the database significantly.
279 NAME="%k" causes a warning now. It's is and always was completely superfluous.
280 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
283 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
284 if they are not the default. To support older kernels, the NAME= rules need to
285 be added to the compat rules file.
287 Symlinks to udevadm with the old command names are no longer resolved to
288 the udevadm commands.
290 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
293 The option "last_rule" does no longer exist. Its use breaks too many
294 things which expect to be run from independent later rules, and is an idication
295 that something needs to be fixed properly instead.
297 The gudev API is no longer marked as experimental,
298 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
299 is enabled by default now. Various projects already depend on introspection
300 information to bind dynamic languages to the gudev interfaces.
306 The udevadm trigger "--retry-failed" option, which is replaced since quite
307 a while by "--type=failed" is removed.
309 The failed tracking was not working at all for a few releases. The RUN
310 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
311 default is not to track any failing RUN executions.
313 New keymaps, new modem, hid2hci updated.
317 Fix possible crash in udevd when worker processes are busy, rules are
318 changed at the same time, and workers get killed to reload the rules.
324 Properties set with ENV{.FOO}="bar" are marked private by starting the
325 name with a '.'. They will not be stored in the database, and not be
326 exported with the event.
328 Firmware files are looked up in:
329 /lib/firmware/updates/$(uname -r)
330 /lib/firmware/updates
331 /lib/firmware/$(uname -r)
335 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
336 ata_id, instead of scsi_id, is the default tool now for ATA devices.
342 The configure options have changed because another library needs to be
343 installed in a different location. Instead of exec_prefix and udev_prefix,
344 libdir, rootlibdir and libexecdir are used. The Details are explained in
347 Event processes now get re-used after they handled an event. This reduces
348 the number of forks and the pressure on the CPU significantly, because
349 cloned event processes no longer cause page faults in the main daemon.
350 After the events have settled, a few worker processes stay around for
351 future events, all others get cleaned up.
353 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
354 Also inotify support is mandatory now to run udev.
356 The format of the queue exported by the udev damon has changed. There is
357 no longer a /dev/.udev/queue/ directory. The current event queue can be
358 accessed with udevadm settle and libudedv.
360 Libudev does not have the unstable API header anymore. From now on,
361 incompatible changes will be handled by bumping the library major version.
363 To build udev from the git tree gtk-doc is needed now. The tarballs will
364 build without it and contain the pre-built documentation. An online copy
366 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
368 The tools from the udev-extras repository have been merged into the main
369 udev repository. Some of the extras have larger external dependencies, and
370 they can be disabled with the configure switch --disable-extras.
376 The program vol_id and the library libvolume_id are removed from the
377 repository. Libvolume_id is merged with libblkid from the util-linux-ng
378 package. Persistent disk links for label and uuid depend on the
379 util-linux-ng version (2.15) of blkid now. Older versions of blkid
380 can not be used with udev.
382 Libudev allows to subscribe to udev events. To prevent unwanted messages
383 to be delivered, and waking up the subscribing process, a filter can be
384 installed, to drop messages inside a kernel socket filter. The filters
385 match on the <subsytem>:<devtype> properties of the device.
386 This is part of the ongoing effort to replace HAL, and switch current
387 users over to directly use libudev.
388 Libudev is still marked as experimental, and its interface might
389 eventually change if needed, but no major changes of the currently exported
390 interface are expected anymore, and a first stable release should happen
393 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
394 is not supported since while and udevd will log an error message at
395 startup. It should still be able to boot-up, but advanced rules and system
396 services which depend on the information not available in the old sysfs
397 format will fail to work correctly.
399 DVB device naming is supplied by the kernel now. In case older kernels
400 need to be supported, the old shell script should be added to a compat
407 The processed udev events get send back to the netlink socket. Libudev
408 provides access to these events. This is work-in-progress, to replace
409 the DeviceKit daemon functionality directly with libudev. There are
410 upcoming kernel changes to allow non-root users to subcribe to these
417 "udevadm settle" now optionally accepts a range of events to wait for,
418 instead of waiting for "all" events.
424 The installed watch for block device metadata changes is now removed
425 during event hadling, because some (broken) tools may be called from udev
426 rules and (wrongly) open the device with write access. After the finished
427 event handling the watch is restored.
433 Device nodes can be watched for changes with inotify with OPTIONS="watch".
434 If closed after being opened for writing, a "change" uevent will occur.
435 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
441 The udevadm test command has no longer a --force option, nodes and symlinks
442 are always updated with a test run now.
444 The udevd daemon can be started with --resolve-names=never to avoid all user
445 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
446 lookup user and groups every time events are handled.
452 We are currently merging the Ubuntu rules in the udev default rules,
453 and get one step closer to provide a common Linux /dev setup, regarding
454 device names, symlinks, and default device permissions. On udev startup,
455 we now expect the following groups to be resolvable to their ids with
457 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
458 LDAP setups need to make sure, that these groups are always resolvable at
459 bootup, with only the rootfs mounted, and without network access available.
461 Some systems may need to add some new, currently not used groups, or need
462 to add some users to new groups, but the cost of this change is minimal,
463 compared to the pain the current, rather random, differences between the
464 various distributions cause for upstream projects and third-party vendors.
466 In general, "normal" users who log into a machine should never be a member
467 of any such group, but the device-access should be managed by dynamic ACLs,
468 which get added and removed for the specific users on login/logout and
469 session activity/inactivity. These groups are only provided for custom setups,
470 and mainly system services, to allow proper privilege separation.
471 A video-streaming daemon uid would be a member of "audio" and "video", to get
472 access to the sound and video devices, but no "normal" user should ever belong
473 to the "audio" group, because he could listen to the built-in microphone with
474 any ssh-session established from the other side of the world.
476 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
477 which do not depend on the kernel device name. As usual, unique
478 devices - only a single one per product connected, or a real
479 USB serial number in the device - are always found with the same
480 name in the by-id/ directory.
481 Completely identical devices may overwrite their names in by-id/
482 and can only be found reliably in the by-path/ directory. Devices
483 specified by by-path/ must not change their connection, like the
484 USB port number they are plugged in, to keep their name.
486 To support some advanced features, Linux 2.6.22 is the oldest supported
487 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
488 supported. Older kernels should still work, and devices nodes should be
489 reliably created, but some rules and libudev will not work correctly because
490 the old kernels do not provide the expected information or interfaces.
496 Fix for a possible segfault while swapping network interface names in udev
503 The group "video" is part of the default rules now.
507 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
508 block devices in some cases. No common distro uses this option anymore,
509 and we do not get enough testing for this and recent udev versions. If
510 this option is not needed to run some old distro with a new kernel,
511 it should be disabled in the kernel config.
513 Bugfix for the $links substitution variable, which may crash if no links
514 are created. This should not happen in usual setups because we always
515 create /dev/{block,char}/ links.
517 The strings of the parsed rules, which are kept in memory, no longer
518 contain duplicate entries, or duplicate tails of strings. This, and the
519 new rules parsing/matching code reduces the total in-memory size of
520 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
523 The export of DEVTYPE=disk/partition got removed from the default
524 rules. This value is available from the kernel. The pnp shell script
525 modprobe hack is removed from the default rules. ACPI devices have _proper_
526 modalias support and take care of the same functionality.
527 Installations which support old kernels, but install current default
528 udev rules may want to add that to the compat rules file.
530 Libvolume_id now always probes for all known filesystems, and does not
531 stop at the first match. Some filesystems are marked as "exclusive probe",
532 and if any other filesytem type matches at the same time, libvolume_id
533 will, by default, not return any probing result. This is intended to prevent
534 mis-detection with conflicting left-over signatures found from earlier
535 file system formats. That way, we no longer depend on the probe-order
536 in case of multiple competing signatures. In some setups the kernel allows
537 to mount a volume with just the old filesystem signature still in place.
538 This may damage the new filesystem and cause data-loss, just by mounting
539 it. Because volume_id can not decide which one the correct signature is,
540 the wrong signatures need to be removed manually from the volume, or the
541 volume needs to be reformatted, to enable filesystem detection and possible
546 Fix segfault if compiled without optimization and dbg() does not get
547 compiled out and uses variables which are not available.
551 Bugfixes. (And maybe new bugs. :))
553 The rule matching engine got converted from a rule list to a token
554 array which reduced the in-memory rules representation of a full
555 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
556 Limits like 5 ENV and ATTR matches, and one single instance for most
557 other keys per rule are gone.
559 The NAME assignment is no longer special cased. If later rules assign
560 a NAME value again, the former value will be overwritten. As usual
561 for most other keys, the NAME value can be protected by doing a final
562 assignment with NAME:="<value>".
564 All udev code now uses libudev, which is also exported. The library
565 is still under development, marked as experimental, and its interface
566 may change as long as the DeviceKit integration is not finished.
568 Many thanks to Alan Jenkins for his continuous help, and finding and
569 optimizing some of the computing expensive parts.
575 Kernel devices and device nodes are connected now by reverse indizes in
576 /sys and /dev. A device number retrieved by a stat() or similar, the
577 kernel device directory can be found by looking up:
578 /sys/dev/{block,char}/<maj>:<min>
579 and the device node of the same device by looking up:
580 /dev/{block,char}/<maj>:<min>
584 Fix recently introduced bug, which caused a compilation without large
585 file support, where vol_id does not recognize raid signatures at the end
588 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
589 Seems some kernel versions prevent the creation of the ieee-* links,
590 so people used the scsi-* link which disappeared now.
592 More libudev work. Almost all udevadm functionality comes from libudev
595 udevadm trigger has a new option --type, which allows to trigger events
596 for "devices", for "subsystems", or "failed" devices. The old option
597 --retry-failed" still works, but is no longer mentioned in the man page.
603 The udevadm info --device-id-of-file= output has changed to use
604 the obvious format. Possible current users should use the --export
605 option which is not affected.
607 The old udev commands symlinks to udevadm are not installed, if
608 these symlinks are used, a warning is printed.
614 Optical drive's media is no longer probed for raid signatures,
615 reading the end of the device causes some devices to malfunction.
616 Also the offset of the last session found is used now to probe
619 The volume_id library got a major version number update to 1,
620 some deprecated functions are removed.
622 A shared library "libudev" gets installed now to provide access
623 to udev device information. DeviceKit, the successor of HAL, will
624 need this library to access the udev database and search sysfs for
626 The library is currently in an experimental state, also the API is
627 expected to change, as long as the DeviceKit integration is not
632 We use ./configure now. See INSTALL for details. Current
635 "/usr" - prefix for man pages, include files
637 "" - the root filesystem, prefix for libs and binaries
641 "lib" - directory name for libraries, not a path name
642 multilib 64bit systems may use "lib64" instead of "lib"
644 compile-in verbose debug messages
646 disable all logging and compile-out all log strings
648 link against SELInux libraries, to set the expected context
651 In the default rules, the group "disk" gets permissions 0660 instead
652 of 0640. One small step closer to unify distro rules. Some day, all
653 distros hopefully end up with the same set of rules.
655 No symlinks to udevadm are installed anymore, if they are still needed,
656 they should be provided by the package.
662 Default udev rules, which are not supposed to be edited by the user, should
663 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
664 the udev package and will be replaced with an update. Udev will pick up rule
666 /lib/udev/rules.d/ - default installed rules
667 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
668 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
669 It does not matter in which directory a rule file lives, all files are sorted
672 To help creating /dev/root, we have now:
673 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
676 In case the current --device-id-of-file is already used, please switch to
677 the --export format version, it saves the output parsing and the old
678 format will be changed to use ':' as a separator, like the format in the
683 Fix cdrom_id to properly recognize blank media.
689 Tape drive id-data is queried from /dev/bsg/* instead of the tape
690 nodes. This avoids rewinding tapes on open().
696 The symlinks udevcontrol and udevtrigger are no longer installed by
699 The scsi_id program does not depend on sysfs anymore. It can speak
700 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
701 data, which should solve some old problems with tape devices, where
702 we better do not open all tape device nodes to identify the device.
708 The cdrom_id program is replaced by an advanced version, which can
709 detect most common device types, and also properties of the inserted
710 media. This is part of moving some basic functionality from HAL into
711 udev (and the kernel).
717 The last WAIT_FOR_SYSFS rule is removed from the default rules.
719 The symlinks to udevadm for the debugging tools: udevmonitor and
720 udevtest are no longer created.
722 The symlinks to the udevadm man page for the old tool names are
725 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
726 should be prefixed with '@' to indicate that the path is not a
737 Udevstart is removed from the tree, it did not get installed for
738 a long time now, and is long replaced by trigger and settle.
744 All udev tools are merged into a single binary called udevadm.
745 The old names of the tools are built-in commands in udevadm now.
746 Symlinks to udevadm, with the names of the old tools, provide
747 the same functionality as the standalone tools. There is also
748 only a single udevadm.8 man page left for all tools.
750 Tools like mkinitramfs should be checked, if they need to include
751 udevadm in the list of files.
761 The etc/udev/rules.d/ directory now contains a default set of basic
762 udev rules. This initial version is the result of a rules file merge
763 of Fedora and openSUSE. For these both distros only a few specific
764 rules are left in their own file, named after the distro. Rules which
765 are optionally installed, because they are only valid for a specific
766 architecture, or rules for subsystems which are not always used are
767 in etc/udev/packages/.
773 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
774 actions by dynamically created rules.
776 SYMLINK=="<value>" matches agains the entries in the list of
777 currently defined symlinks. The links are not created in the
778 filesystem at that point in time, but the values can be matched.
780 RUN{ignore_error}+="<program>" will ignore any exit code from the
781 program and not record as a failed event.
787 Final merge of patches/features from the Ubuntu package.
793 Control characters in filesystem label strings are no longer silenty
794 removed, but hex-encoded, to be able to uniquely identify the device
795 by its symlink in /dev/disk/by-label/.
796 If libvolume_id is used by mount(8), LABEL= will work as expected,
797 if slashes or other characters are used in the label string.
799 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
800 can be specified now. The TEST key accepts an optional mode mask
801 TEST{0100}=="<is executable file>".
803 Scsi_id now supports a mode without expecting scsi-specific sysfs
804 entries to allow the extraction of cciss-device persistent properties.
810 In the future, we may see uuid's which are just simple character
811 strings (see the DDF Raid Specification). For that reason vol_id now
812 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
813 the creation of symlinks, the *_SAFE values ensure, that no control
814 or whitespace characters are used in the filename.
816 Possible users of libvolume_id, please use the volume_id_get_* functions.
817 The public struct will go away in a future release of the library.
823 Removal of useless extras/eventrecorder.sh.
833 The directory multiplexer for dev.d/ and hotplug.d are finally removed
834 from the udev package.
840 Symlinks can have priorities now, the priority is assigned to the device
841 and specified with OPTIONS="link_priority=100". Devices with higher
842 priorities overwrite the symlinks of devices with lower priorities.
843 If the device that currently owns the link, goes away, the symlink
844 will be removed, and recreated, pointing to the next device with the
845 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
846 more reliable, if multiple devices contain the same metadata and overwrite
849 The dasd_id program is removed from the udev tree, and dasdinfo, with the
850 needed rules, are part of the s390-tools now.
852 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
853 we may get the scsi sysfs mess fixed some day, and this will only catch
854 the devices we are looking for.
856 USB serial numbers for storage devices have the target:lun now appended,
857 to make it possibble to distinguish broken multi-lun devices with all
858 the same SCSI identifiers.
860 Note: The extra "run_directory" which searches and executes stuff in
861 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
862 with the next release. Make sure, that you don't use it anymore, or
863 provides your own implementation of that inefficient stuff.
864 We are tired of reports about a "slow udev", because these directories
865 contain stuff, that runs with _every_ event, instead of using rules,
866 that run programs only for the matching events.
876 DRIVER== will match only for devices that actually have a real
877 driver. DRIVERS== must be used, if parent devices should be
878 included in the match.
880 Libvolume_id's "linux_raid" detection needed another fix.
888 Add additional check to volume_id detection of via_raid, cause
889 some company decided to put a matching pattern all over the empty
890 storage area of their music players.
894 Fix path_id for SAS devices.
898 The udev daemon can be started with --debug-trace now, which will
899 execute all events serialized to get a chance to catch a possible
900 action that crashes the box.
902 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
903 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
904 are excluded from the warning. Referencing parent attributes directly
905 may break when something in the kernel driver model changes. Udev will
906 just find the attribute by walking up the parent chain.
908 Udevtrigger now sorts the list of devices depending on the device
909 dependency, so a "usb" device is triggered after the parent "pci"
914 Revert persistent-storage ata-serial '_' '-' replacement.
920 Udevtrigger can now filter the list of devices to be triggered. Matches
921 for subsystems or sysfs attributes can be specified.
923 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
924 zero-sized files to avoid pointing to /sys and confuse broken tools which
925 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
928 The rules and scripts to create udev rules for persistent network
929 devices and optical drives are in the extras/rules_generator directory
930 now. If you use something similar, please consider replacing your own
931 version with this, to share the support effort. The rule_generator
932 installs its own rules into /etc/udev/rules.d.
934 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
935 the rule_generator depends on cdrom_id to be called in an earlier rule.
941 Renaming of some key names (the old names still work):
942 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
943 (The behavior of the key DRIVER will change soon in one of the next
944 releases, to match only the event device, please switch to DRIVERS
945 instead. If DRIVER is used, it will behave like DRIVERS, but an error
947 With the new key names, we have a more consistent and simpler scheme.
948 We can match the properties of the event device only, with: KERNEL,
949 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
950 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
951 longer mentioned in the man page and should be switched in the rule
954 ATTR{file}="value" can be used now, to write to a sysfs file of the
955 event device. Instead of:
956 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
958 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
960 All the PHYSDEV* keys are deprecated and will be removed from a
962 PHYDEVPATH - is the path of a parent device and should not be
964 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
965 matched with SUBSYSTEMS==
966 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
967 Newer kernels will have DRIVER in the environment,
968 for older kernels udev puts in. Class device will
969 no longer carry this property of a parent and
970 DRIVERS== can be used to match such a parent value.
971 Note that ENV{DRIVER} is only available for a few bus devices, where
972 the driver is already bound at device event time. On coldplug, the
973 events for a lot devices are already bound to a driver, and they will have
974 that value set. But on hotplug, at the time the kernel creates the device,
975 it can't know what driver may claim the device after that, therefore
976 in most cases it will be empty.
978 Failed events should now be re-triggered with:
979 udevtrigger --retry-failed.
980 Please switch to this command, so we keep the details of the /dev/.udev/failed/
981 files private to the udev tools. We may need to switch the current symlink
982 target, cause some obviously broken tools try to scan all files in /dev
983 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
984 million times. This takes ages on slow boxes.
986 The udevinfo attribute walk (-a) now works with giving a device node
987 name (-n) instead of a devpath (-p). The query now always works, also when
988 no database file was created by udev.
990 The built-in /etc/passwd /etc/group parser is removed, we always depend on
991 getpwnam() and getgrnam() now. One of the next releases will depend on
992 fnmatch() and may use getopt_long().
996 Bugfixes and small improvements.
1000 Fix path_id for recent kernels.
1006 Added support for swapping network interface names, by temporarily
1007 renaming the device and wait for the target name to become free.
1011 The built-in MODALIAS key and substitution is removed.
1015 The binary firmware helper is replaced by the usual simple
1016 shell script. Udevsend is removed from the tree.
1024 Some more keys require the correct use of '==' and '=' depending
1025 on the kind of operation beeing an assignment or a match. Rules
1026 with invalid operations are skipped and logged to syslog. Please
1027 test with udevtest if the parsing of your rules throws errors and
1028 fix possibly broken rules.
1032 Provide "udevsettle" to wait for all current udev events to finish.
1033 It also watches the current kernel netlink queue by comparing the
1034 even sequence number to make sure that there are no current pending
1035 events that have not already arrived in the daemon.
1039 Fix rule to skip persistent rules for removable IDE devices, which
1040 also skipped optical IDE drives.
1042 All *_id program are installed in /lib/udev/ by default now.
1044 No binary is stripped anymore as this should be done in the
1045 packaging process and not at build time.
1047 libvolume_id is provided as a shared library now and vol_id is
1048 linked against it. Also one of the next HAL versions will require
1049 this library, and the HAL build process will also require the
1050 header file to be installed. The copy of the same code in HAL will
1051 be removed to have only a single copy left on the system.
1055 Add persistent links for SCSI tapes. The rules file is renamed
1056 to 60-persistent-storage.rules.
1058 Create persistent path for usb devices. Can be used for all sorts
1059 of devices that can't be distinguished by other properties like
1060 multiple identical keyboards and mice connected to the same box.
1062 Provide "udevtrigger" program to request events on coldplug. The
1063 shell script is much too slow with thousends of devices.
1067 Fix persistent disk rules to exclude removable IDE drives.
1069 Warn if %e, $modalias or MODALIAS is used.
1073 Fix queue export, which wasn't correct for subsequent add/remove
1074 events for the same device.
1078 Fix cramfs detection on big endian.
1080 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1085 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1086 attributes were only checked at the parent device that matched the
1087 by BUS requested subsystem. Fix it to also look at the device we
1088 received the event for.
1090 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1095 Fix a bug where NAME="" would prevent RUN from beeing executed.
1097 RUN="/bin/program" does not longer automatically add the subsystem
1098 as the first parameter. This is from the days of /sbin/hotplug
1099 which is dead now and it's just confusing to need to add a space at
1100 the end of the program name to prevent this.
1101 If you use rules that need the subsystem as the first parameter,
1102 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1103 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1107 The udev man page has moved to udev(7) as it does not describe a command
1108 anymore. The programs udev, udevstart and udevsend are no longer installed
1109 by default and must be copied manually, if they should be installed or
1110 included in a package.
1112 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1113 the ignore rule was applied.
1115 More preparation for future sysfs changes. usb_id and scsi_id no longer
1116 depend on a magic order of devices in the /devices chain. Specific devices
1117 should be requested by their subsytem.
1119 This will always find the scsi parent device without depending on a specific
1121 dev = sysfs_device_get(devpath);
1122 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1124 The "device" link in the current sysfs layout will be automatically
1125 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1126 parent in the devpath. If a device is requested by it's symlink, like all
1127 class devices in the new sysfs layout will look like, it gets automatically
1128 resolved and substituted with the real devpath and not the symlink path.
1131 A similar logic must be applied to _all_ sysfs users, including
1132 scripts, that search along parent devices in sysfs. The explicit use of
1133 the "device" link must be avoided. With the future sysfs layout all
1134 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1135 back to the "class" or the "bus". The layout of the parent devices in
1136 /devices is not necessarily expected to be stable across kernel releases and
1137 searching for parents by their subsystem should make sysfs users tolerant
1138 for changed parent chains.
1142 Prepare udev to work with the experimental kernel patch, that moves
1143 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1145 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1146 moving the class devices to /sys/devices.
1148 Thanks again to Marco for help finding a hopefully nice compromise
1149 to make %b simpler and working again.
1153 Complete removal of libsysfs, replaced by simple helper functions
1154 which are much simpler and a bit faster. The udev daemon operatesentirely
1155 on event parameters and does not use sysfs for simple rules anymore.
1156 Please report any new bugs/problems, that may be caused by this big
1157 change. They will be fixed immediately.
1159 The enumeration format character '%e' is deprecated and will be
1160 removed sometimes from a future udev version. It never worked correctly
1161 outside of udevstart, so we can't use it with the new parallel
1162 coldplug. A simple enumeration is as useless as the devfs naming
1163 scheme, just get rid of both if you still use it.
1165 MODALIAS and $modalias is not needed and will be removed from one of
1166 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1167 the sysfs "modalias" value.
1169 Thanks a lot to Marco for all his help on finding and fixing bugs.
1173 Let scsi_id request libata drive serial numbers from page 0x80.
1175 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1176 added /dev/disk/by-name/* for device mapper device names.
1178 Removed %e from the man page. It never worked reliably outside
1179 of udevstart and udevstart is no longer recommended to use.
1183 Symlinks are now exported to the event environment. Hopefully it's no
1184 longer needed to run udevinfo from an event process, like it was
1185 mentioned on the hotplug list:
1186 UDEV [1134776873.702967] add@/block/sdb
1189 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1193 Fix a problem if udevsend is used as the hotplug handler and tries to use
1194 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1195 and this kind of problems will hopefully go away soon.
1199 All built-in logic to work around bad sysfs timing is removed with this
1200 version. The need to wait for sysfs files is almost fixed with a kernel
1201 version that doesn't work with this udev version anyway. Until we fix
1202 the timing of the "bus" link creation, the former integrated logic should
1203 be emulated by a rule placed before all other rules:
1204 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1206 The option "udev_db" does no longer exist. All udev state will be in
1207 /$udev_root/.udev/ now, there is no longer an option to set this
1209 If the init script or something else used this value, just depend on
1210 this hardcoded path. But remember _all_content_ of this directory is
1211 still private to udev and can change at any time.
1213 Default location for rule sripts and helper programs is now: /lib/udev/.
1214 Everything that is not useful on the commandline should go into this
1215 directory. Some of the helpers in the extras folder are installed there
1216 now. The rules need to be changed, to find the helpers there.
1218 Also /lib/udev/devices is recommended as a directory where packages or
1219 the user can place real device nodes, which get copied over to /dev at
1220 every boot. This should replace the various solutions with custom config
1223 Udevsend does no longer start the udev daemon. This must be done with
1224 the init script that prepares /dev on tmpfs and creates the initial nodes,
1225 before starting the daemon.
1229 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1232 The copy of klibc is removed. A systemwide installed version of klibc
1233 should be used to build a klibc udev now.
1237 NAME="" will not create any nodes, but execute RUN keys. To completely
1238 ignore an event the OPTION "ignore_device" should be used.
1240 After removal of the reorder queue, events with a TIMEOUT can be executed
1241 without any queuing now.
1245 Fixed bug in udevd, if inotify is not available. We depend on netlink
1246 uevents now, kernels without that event source will not work with that
1247 version of udev anymore.
1251 The rule parsing happens now in the daemon once at startup, all udev
1252 event processes inherit the already parsed rules from the daemon.
1253 It is shipped with SUSE10.0 and reduces heavily the system load at
1254 startup. The option to save precompiled rules and let the udev process
1255 pick the them up is removed, as it's no longer needed.
1257 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1258 device. Libsysfs is changed to "translate" the requested link into the
1259 real device path, as it would happen with the hotplug event. Otherwise
1260 device removal and the udev database will not work.
1262 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1265 A few improvements for vol_id, the filesytem probing code.
1269 Fix a stupid typo in extras/run_directory for "make install".
1271 scsi_id creates the temporary devnode now in /dev for usage with a
1272 non-writable /tmp directory.
1274 The uevent kernel socket buffer can carry app. 50.000 events now,
1275 let's see who can break this again. :)
1277 The upcoming kernel will have a new input driver core integration.
1278 Some class devices are now symlinks to the real device. libsysfs
1279 needs a fix for this to work correctly. Udevstart of older udev
1280 versions will _not_ create these devices!
1284 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1289 A bunch of mostly trivial bugfixes. From now on no node name or
1290 symlink name can contain any character than plain whitelisted ascii
1291 characters or validated utf8 byte-streams. This is needed for the
1292 /dev/disk/by-label/* links, because we import untrusted data and
1293 export it to the filesystem.
1297 More bugfixes. If udevd was started from the kernel, we don't
1298 have stdin/stdout/stderr, which broke the forked tools in some
1303 Bugfix. udevstart event ordering was broken for a long time.
1304 The new run_program() uncovered it, because /dev/null was not
1305 available while we try to run external programs.
1306 Now udevstart should create it before we run anything.
1310 Minor bugfixes and some distro rules updates. If you don't have the
1311 persistent disk rules in /dev/disk/by-*/* on your distro, just
1312 grab it from here. :)
1316 We can use socket communication now to pass events from udev to
1318 RUN+="socket:/org/freedesktop/hal/udev_event"
1319 will pass the whole udev event to the HAL daemon without the need
1320 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1324 Mostly bugfixes and see ChangeLog.
1326 The test for the existence of an environment value should be
1328 ENV{KEY}=="*" to ENV{KEY}=="?*"
1329 because "*" will not fail anymore, if the key does not exist or
1334 Bugfixes and a few tweaks described in the ChangeLog.
1338 Mostly a Bugfix release.
1340 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1341 timing with custom rules.
1345 We changed the internal rule storage format. Our large rule files took
1346 2 MB of RAM, with the change we are down to 99kB.
1348 If the device-node has been created with default name and no symlink or
1349 options are to remenber, it is not longer stored in the udevdb. HAL will
1350 need to be updated to work correctly with that change.
1352 To overrride optimization flags, OPTFLAGS may be used now.
1360 Major changes happened with this release. The goal is to take over the
1361 complete kernel-event handling and provide a more efficient way to dispatch
1362 kernel events. Replacing most of the current shell script logic and the
1363 kernel forked helper with a netlink-daemon and a rule-based event handling.
1365 o udevd listens to netlink events now. The first valid netlink event
1366 will make udevd ignore any message from udevsend that contains a
1367 SEQNUM, to avoid duplicate events. The forked events can be disabled
1369 echo "" > /proc/sys/kernel/hotplug
1370 For full support, the broken input-subsytem needs to be fixed, not to
1371 bypass the driver core.
1373 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1374 removed from udev itself and must be emulated by calling small
1375 helper binaries provided in the extras folder:
1376 make EXTRAS=extras/run_directory/
1377 will build udev_run_devd and udev_run_hotplugd, which can be called
1378 from a rule if needed:
1379 RUN+="/sbin/udev_run_hotplugd"
1380 The recommended way to handle this is to convert all the calls from
1381 the directories to explicit udev rules and get completely rid of the
1382 multiplexing. (To catch a ttyUSB event, you now no longer need to
1383 fork and exit 300 tty script instances you are not interested in, it
1384 is just one rule that matches exactly the device.)
1386 o udev handles now _all_ events not just events for class and block
1387 devices, this way it is possible to control the complete event
1388 behavior with udev rules. Especially useful for rules like:
1389 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1391 o As used in the modalias rule, udev supports now textual
1392 substitution placeholder along with the usual format chars. This
1393 needs to be documented, for now it's only visible in udev_rules_parse.c.
1395 o The rule keys support now more operations. This is documented in the
1396 man page. It is possible to add values to list-keys like the SYMLINK
1397 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1398 Also "final"-assignments are supported by using KEY:="value", which will
1399 prevent changing the key by any later rule.
1401 o kernel 2.6.12 has the "detached_state" attribute removed from
1402 sysfs, which was used to recognize sysfs population. We switched that
1403 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1404 Running this udev version on older kernels may cause a short delay for
1407 o To provide infrastructure for persistent device naming, the id programs:
1408 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1409 to export the probed data in environment key format:
1410 pim:~ # /sbin/ata_id --export /dev/hda
1411 ID_MODEL=HTS726060M9AT00
1412 ID_SERIAL=MRH401M4G6UM9B
1413 ID_REVISION=MH4OA6BA
1415 The following rules:
1416 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1417 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1420 kay@pim:~> tree /dev/disk
1423 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1424 | `-- IBM-Memory_Key -> ../../sda
1426 | |-- swap -> ../../hda1
1427 | |-- date -> ../../sda1
1428 | `-- home -> ../../hda3
1430 |-- 2E08712B0870F2E7 -> ../../hda3
1431 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1432 |-- E845-7A89 -> ../../sda1
1433 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1435 The IMPORT= operation will import these keys in the environment and make
1436 it available for later PROGRAM= and RUN= executed programs. The keys are
1437 also stored in the udevdb and can be queried from there with one of the
1440 o A few binaries are silently added to the repository, which can be used
1441 to replay kernel events from initramfs instead of using coldplug. udevd
1442 can be instructed now to queue-up events while the stored events from
1443 initramfs are filled into the udevd-queue. This code is still under
1444 development and there is no documentation now besides the code itself.
1445 The additional binaries get compiled, but are not installed by default.
1447 o There is also a temporary fix for a performance problem where too many
1448 events happen in parallel and every event needs to parse the rules.
1449 udev can now read precompiled rules stored on disk. This is likely to be
1450 replaced by a more elegant solution in a future udev version.
1454 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1455 Fix for libsysfs not to expect this file was added.
1459 All rules are applied now, but only the first matching rule with a NAME-key
1460 will be applied. All later rules with NAME-key are completely ignored. This
1461 way system supplied symlinks or permissions gets applied to user-defined
1465 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1466 to some rules, to keep the old behavior.
1468 The rules are read on "remove"-events too. That makes is possible to match
1469 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1470 instruct udev to ignore an event (OPTIONS="ignore_device").
1471 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1473 The new RUN-key supports rule-based execution of programs after device-node
1474 handling. This is meant as a general replacement for the dev.d/-directories
1475 to give fine grained control over the execution of programs.
1477 The %s{}-sysfs format char replacement values are searched at any of the
1478 devices in the device chain now, not only at the class-device.
1480 We support log priority levels now. The value udev_log in udev.conf is used
1481 to determine what is printed to syslog. This makes it possible to
1482 run a version with compiled-in debug messages in a production environment
1483 which is sometimes needed to find a bug.
1484 It is still possible to supress the inclusion of _any_ syslog usage with
1485 USE_LOG=false to create the smallest possible binaries if needed.
1486 The configured udev_log value can be overridden with the environment variable
1491 Possible use of a system-wide klibc:
1492 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1493 will link against an external klibc and our own version will be ignored.
1497 We support an unlimited count of symlinks now.
1499 If USE_STATIC=true is passed to a glibc build, we link statically and use
1500 a built-in userdb parser to resolve user and group names.
1502 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1503 we walk up the chain of physical devices to find a match.
1505 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1506 easy to skip certain attribute matches without composing rules with weird
1507 character class negations like:
1508 KERNEL="[!s][!c][!d]*"
1509 this can now be replaced with:
1511 The current simple '=' is still supported, and should work as it does today,
1512 but existing rules should be converted if possible, to be better readable.
1514 We have new ENV{}== key now, to match against a maximum of 5 environment
1517 udevstart is its own binary again, because we don't need co carry this araound
1518 with every forked event.