9 Now the udev daemon itself, does on startup:
10 - copy the content of /lib/udev/devices to /dev
11 - create the standard symlinks like /dev/std{in,out,err},
12 /dev/core, /dev/fd, ...
13 - use static node information provided by kernel modules
14 and creates these nodes to allow module on-demand loading
15 - possibly apply permissions to all ststic nodes from udev
16 rules which are annotated to match a static node
18 The default mode for a device node is 0600 now to match the kernel
19 created devtmpfs defaults. If GROUP= is specified and no MODE= is
20 given the default will be 0660.
26 Udev now gradually starts to pass control over the primary device nodes
27 and their names to the kernel, and will in the end only manage the
28 permissions of the node, and possibly create additional symlinks.
29 As a first step NAME="" will be ignored, and NAME= setings with names
30 other than the kernel provided name will result in a logged warning.
31 Kernels that don't provide device names, or devtmpfs is not used, will
32 still work as they did before, but it is strongly recommended to use
33 only the same names for the primary device node as the recent kernel
34 provides for all devices.
38 Fix broken firmware loader search path.
44 "udevadm trigger" defaults to "change" events now instead of "add"
45 events. The "udev boot script" might need to add "--action=add" to
46 the trigger command if not already there, in case the initial coldplug
47 events are expected as "add" events.
49 The option "all_partitons" was removed from udev. This should not be
50 needed for usual hardware. Udev can not safely make assumptions
51 about non-existing partition major/minor numbers, and therefore no
52 longer provide this unreliable and unsafe option.
54 The option "ignore_remove" was removed from udev. With devtmpfs
55 udev passed control over device nodes to the kernel. This option
56 should not be needed, or can not work as advertised. Neither
57 udev nor the kernel will remove device nodes which are copied from
58 the /lib/udev/devices/ directory.
60 All "add|change" matches are replaced by "!remove" in the rules and
61 in the udev logic. All types of events will update possible symlinks
62 and permissions, only "remove" is handled special now.
64 The modem modeswitch extra was removed and the external usb_modeswitch
65 program should be used instead.
67 New and fixed keymaps.
77 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
78 depend on the current sysfs layout and the information not available in the
79 deprecated layout. All remaining support for the deprecated sysfs layout is
84 Fix for a possible endless loop in the new input_id program.
90 The option "ignore_device" does no longer exist. There is no way to
91 ignore an event, as libudev events can not be suppressed by rules.
92 It only prevented RUN keys from being executed, which results in an
93 inconsistent behavior in current setups.
95 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
96 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
99 The support for the deprecated IDE devices has been removed from the
100 default set of rules. Distros who still care about non-libata drivers
101 need to add the rules to the compat rules file.
103 The ID_CLASS property on input devices has been replaced by the more accurate
104 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
105 determined by the new "input_id" prober now. Some devices, such as touchpads,
106 can have several classes. So if you previously had custom udev rules which e. g.
107 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
108 ENV{ID_INPUT_KEYBOARD}=="?*".
114 To support DEVPATH strings larger than the maximum file name length, the
115 private udev database format has changed. If some software still reads the
116 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
117 Please do not port anything to the new format again, everything in /dev/.udev
118 is and always was private to udev, and may and will change any time without
121 Multiple devices claiming the same names in /dev are limited to symlinks
122 only now. Mixing identical symlink names and node names is not supported.
123 This reduces the amount of data in the database significantly.
125 NAME="%k" causes a warning now. It's is and always was completely superfluous.
126 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
129 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
130 if they are not the default. To support older kernels, the NAME= rules need to
131 be added to the compat rules file.
133 Symlinks to udevadm with the old command names are no longer resolved to
134 the udevadm commands.
136 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
139 The option "last_rule" does no longer exist. Its use breaks too many
140 things which expect to be run from independent later rules, and is an idication
141 that something needs to be fixed properly instead.
143 The gudev API is no longer marked as experimental,
144 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
145 is enabled by default now. Various projects already depend on introspection
146 information to bind dynamic languages to the gudev interfaces.
152 The udevadm trigger "--retry-failed" option, which is replaced since quite
153 a while by "--type=failed" is removed.
155 The failed tracking was not working at all for a few releases. The RUN
156 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
157 default is not to track any failing RUN executions.
159 New keymaps, new modem, hid2hci updated.
163 Fix possible crash in udevd when worker processes are busy, rules are
164 changed at the same time, and workers get killed to reload the rules.
170 Properties set with ENV{.FOO}="bar" are marked private by starting the
171 name with a '.'. They will not be stored in the database, and not be
172 exported with the event.
174 Firmware files are looked up in:
175 /lib/firmware/updates/$(uname -r)
176 /lib/firmware/updates
177 /lib/firmware/$(uname -r)
181 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
182 ata_id, instead of scsi_id, is the default tool now for ATA devices.
188 The configure options have changed because another library needs to be
189 installed in a different location. Instead of exec_prefix and udev_prefix,
190 libdir, rootlibdir and libexecdir are used. The Details are explained in
193 Event processes now get re-used after they handled an event. This reduces
194 the number of forks and the pressure on the CPU significantly, because
195 cloned event processes no longer cause page faults in the main daemon.
196 After the events have settled, a few worker processes stay around for
197 future events, all others get cleaned up.
199 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
200 Also inotify support is mandatory now to run udev.
202 The format of the queue exported by the udev damon has changed. There is
203 no longer a /dev/.udev/queue/ directory. The current event queue can be
204 accessed with udevadm settle and libudedv.
206 Libudev does not have the unstable API header anymore. From now on,
207 incompatible changes will be handled by bumping the library major version.
209 To build udev from the git tree gtk-doc is needed now. The tarballs will
210 build without it and contain the pre-built documentation. An online copy
212 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
214 The tools from the udev-extras repository have been merged into the main
215 udev repository. Some of the extras have larger external dependencies, and
216 they can be disabled with the configure switch --disable-extras.
222 The program vol_id and the library libvolume_id are removed from the
223 repository. Libvolume_id is merged with libblkid from the util-linux-ng
224 package. Persistent disk links for label and uuid depend on the
225 util-linux-ng version (2.15) of blkid now. Older versions of blkid
226 can not be used with udev.
228 Libudev allows to subscribe to udev events. To prevent unwanted messages
229 to be delivered, and waking up the subscribing process, a filter can be
230 installed, to drop messages inside a kernel socket filter. The filters
231 match on the <subsytem>:<devtype> properties of the device.
232 This is part of the ongoing effort to replace HAL, and switch current
233 users over to directly use libudev.
234 Libudev is still marked as experimental, and its interface might
235 eventually change if needed, but no major changes of the currently exported
236 interface are expected anymore, and a first stable release should happen
239 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
240 is not supported since while and udevd will log an error message at
241 startup. It should still be able to boot-up, but advanced rules and system
242 services which depend on the information not available in the old sysfs
243 format will fail to work correctly.
245 DVB device naming is supplied by the kernel now. In case older kernels
246 need to be supported, the old shell script should be added to a compat
253 The processed udev events get send back to the netlink socket. Libudev
254 provides access to these events. This is work-in-progress, to replace
255 the DeviceKit daemon functionality directly with libudev. There are
256 upcoming kernel changes to allow non-root users to subcribe to these
263 "udevadm settle" now optionally accepts a range of events to wait for,
264 instead of waiting for "all" events.
270 The installed watch for block device metadata changes is now removed
271 during event hadling, because some (broken) tools may be called from udev
272 rules and (wrongly) open the device with write access. After the finished
273 event handling the watch is restored.
279 Device nodes can be watched for changes with inotify with OPTIONS="watch".
280 If closed after being opened for writing, a "change" uevent will occur.
281 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
287 The udevadm test command has no longer a --force option, nodes and symlinks
288 are always updated with a test run now.
290 The udevd daemon can be started with --resolve-names=never to avoid all user
291 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
292 lookup user and groups every time events are handled.
298 We are currently merging the Ubuntu rules in the udev default rules,
299 and get one step closer to provide a common Linux /dev setup, regarding
300 device names, symlinks, and default device permissions. On udev startup,
301 we now expect the following groups to be resolvable to their ids with
303 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
304 LDAP setups need to make sure, that these groups are always resolvable at
305 bootup, with only the rootfs mounted, and without network access available.
307 Some systems may need to add some new, currently not used groups, or need
308 to add some users to new groups, but the cost of this change is minimal,
309 compared to the pain the current, rather random, differences between the
310 various distributions cause for upstream projects and third-party vendors.
312 In general, "normal" users who log into a machine should never be a member
313 of any such group, but the device-access should be managed by dynamic ACLs,
314 which get added and removed for the specific users on login/logout and
315 session activity/inactivity. These groups are only provided for custom setups,
316 and mainly system services, to allow proper privilege separation.
317 A video-streaming daemon uid would be a member of "audio" and "video", to get
318 access to the sound and video devices, but no "normal" user should ever belong
319 to the "audio" group, because he could listen to the built-in microphone with
320 any ssh-session established from the other side of the world.
322 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
323 which do not depend on the kernel device name. As usual, unique
324 devices - only a single one per product connected, or a real
325 USB serial number in the device - are always found with the same
326 name in the by-id/ directory.
327 Completely identical devices may overwrite their names in by-id/
328 and can only be found reliably in the by-path/ directory. Devices
329 specified by by-path/ must not change their connection, like the
330 USB port number they are plugged in, to keep their name.
332 To support some advanced features, Linux 2.6.22 is the oldest supported
333 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
334 supported. Older kernels should still work, and devices nodes should be
335 reliably created, but some rules and libudev will not work correctly because
336 the old kernels do not provide the expected information or interfaces.
342 Fix for a possible segfault while swapping network interface names in udev
349 The group "video" is part of the default rules now.
353 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
354 block devices in some cases. No common distro uses this option anymore,
355 and we do not get enough testing for this and recent udev versions. If
356 this option is not needed to run some old distro with a new kernel,
357 it should be disabled in the kernel config.
359 Bugfix for the $links substitution variable, which may crash if no links
360 are created. This should not happen in usual setups because we always
361 create /dev/{block,char}/ links.
363 The strings of the parsed rules, which are kept in memory, no longer
364 contain duplicate entries, or duplicate tails of strings. This, and the
365 new rules parsing/matching code reduces the total in-memory size of
366 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
369 The export of DEVTYPE=disk/partition got removed from the default
370 rules. This value is available from the kernel. The pnp shell script
371 modprobe hack is removed from the default rules. ACPI devices have _proper_
372 modalias support and take care of the same functionality.
373 Installations which support old kernels, but install current default
374 udev rules may want to add that to the compat rules file.
376 Libvolume_id now always probes for all known filesystems, and does not
377 stop at the first match. Some filesystems are marked as "exclusive probe",
378 and if any other filesytem type matches at the same time, libvolume_id
379 will, by default, not return any probing result. This is intended to prevent
380 mis-detection with conflicting left-over signatures found from earlier
381 file system formats. That way, we no longer depend on the probe-order
382 in case of multiple competing signatures. In some setups the kernel allows
383 to mount a volume with just the old filesystem signature still in place.
384 This may damage the new filesystem and cause data-loss, just by mounting
385 it. Because volume_id can not decide which one the correct signature is,
386 the wrong signatures need to be removed manually from the volume, or the
387 volume needs to be reformatted, to enable filesystem detection and possible
392 Fix segfault if compiled without optimization and dbg() does not get
393 compiled out and uses variables which are not available.
397 Bugfixes. (And maybe new bugs. :))
399 The rule matching engine got converted from a rule list to a token
400 array which reduced the in-memory rules representation of a full
401 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
402 Limits like 5 ENV and ATTR matches, and one single instance for most
403 other keys per rule are gone.
405 The NAME assignment is no longer special cased. If later rules assign
406 a NAME value again, the former value will be overwritten. As usual
407 for most other keys, the NAME value can be protected by doing a final
408 assignment with NAME:="<value>".
410 All udev code now uses libudev, which is also exported. The library
411 is still under development, marked as experimental, and its interface
412 may change as long as the DeviceKit integration is not finished.
414 Many thanks to Alan Jenkins for his continuous help, and finding and
415 optimizing some of the computing expensive parts.
421 Kernel devices and device nodes are connected now by reverse indizes in
422 /sys and /dev. A device number retrieved by a stat() or similar, the
423 kernel device directory can be found by looking up:
424 /sys/dev/{block,char}/<maj>:<min>
425 and the device node of the same device by looking up:
426 /dev/{block,char}/<maj>:<min>
430 Fix recently introduced bug, which caused a compilation without large
431 file support, where vol_id does not recognize raid signatures at the end
434 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
435 Seems some kernel versions prevent the creation of the ieee-* links,
436 so people used the scsi-* link which disappeared now.
438 More libudev work. Almost all udevadm functionality comes from libudev
441 udevadm trigger has a new option --type, which allows to trigger events
442 for "devices", for "subsystems", or "failed" devices. The old option
443 --retry-failed" still works, but is no longer mentioned in the man page.
449 The udevadm info --device-id-of-file= output has changed to use
450 the obvious format. Possible current users should use the --export
451 option which is not affected.
453 The old udev commands symlinks to udevadm are not installed, if
454 these symlinks are used, a warning is printed.
460 Optical drive's media is no longer probed for raid signatures,
461 reading the end of the device causes some devices to malfunction.
462 Also the offset of the last session found is used now to probe
465 The volume_id library got a major version number update to 1,
466 some deprecated functions are removed.
468 A shared library "libudev" gets installed now to provide access
469 to udev device information. DeviceKit, the successor of HAL, will
470 need this library to access the udev database and search sysfs for
472 The library is currently in an experimental state, also the API is
473 expected to change, as long as the DeviceKit integration is not
478 We use ./configure now. See INSTALL for details. Current
481 "/usr" - prefix for man pages, include files
483 "" - the root filesystem, prefix for libs and binaries
487 "lib" - directory name for libraries, not a path name
488 multilib 64bit systems may use "lib64" instead of "lib"
490 compile-in verbose debug messages
492 disable all logging and compile-out all log strings
494 link against SELInux libraries, to set the expected context
497 In the default rules, the group "disk" gets permissions 0660 instead
498 of 0640. One small step closer to unify distro rules. Some day, all
499 distros hopefully end up with the same set of rules.
501 No symlinks to udevadm are installed anymore, if they are still needed,
502 they should be provided by the package.
508 Default udev rules, which are not supposed to be edited by the user, should
509 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
510 the udev package and will be replaced with an update. Udev will pick up rule
512 /lib/udev/rules.d/ - default installed rules
513 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
514 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
515 It does not matter in which directory a rule file lives, all files are sorted
518 To help creating /dev/root, we have now:
519 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
522 In case the current --device-id-of-file is already used, please switch to
523 the --export format version, it saves the output parsing and the old
524 format will be changed to use ':' as a separator, like the format in the
529 Fix cdrom_id to properly recognize blank media.
535 Tape drive id-data is queried from /dev/bsg/* instead of the tape
536 nodes. This avoids rewinding tapes on open().
542 The symlinks udevcontrol and udevtrigger are no longer installed by
545 The scsi_id program does not depend on sysfs anymore. It can speak
546 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
547 data, which should solve some old problems with tape devices, where
548 we better do not open all tape device nodes to identify the device.
554 The cdrom_id program is replaced by an advanced version, which can
555 detect most common device types, and also properties of the inserted
556 media. This is part of moving some basic functionality from HAL into
557 udev (and the kernel).
563 The last WAIT_FOR_SYSFS rule is removed from the default rules.
565 The symlinks to udevadm for the debugging tools: udevmonitor and
566 udevtest are no longer created.
568 The symlinks to the udevadm man page for the old tool names are
571 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
572 should be prefixed with '@' to indicate that the path is not a
583 Udevstart is removed from the tree, it did not get installed for
584 a long time now, and is long replaced by trigger and settle.
590 All udev tools are merged into a single binary called udevadm.
591 The old names of the tools are built-in commands in udevadm now.
592 Symlinks to udevadm, with the names of the old tools, provide
593 the same functionality as the standalone tools. There is also
594 only a single udevadm.8 man page left for all tools.
596 Tools like mkinitramfs should be checked, if they need to include
597 udevadm in the list of files.
607 The etc/udev/rules.d/ directory now contains a default set of basic
608 udev rules. This initial version is the result of a rules file merge
609 of Fedora and openSUSE. For these both distros only a few specific
610 rules are left in their own file, named after the distro. Rules which
611 are optionally installed, because they are only valid for a specific
612 architecture, or rules for subsystems which are not always used are
613 in etc/udev/packages/.
619 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
620 actions by dynamically created rules.
622 SYMLINK=="<value>" matches agains the entries in the list of
623 currently defined symlinks. The links are not created in the
624 filesystem at that point in time, but the values can be matched.
626 RUN{ignore_error}+="<program>" will ignore any exit code from the
627 program and not record as a failed event.
633 Final merge of patches/features from the Ubuntu package.
639 Control characters in filesystem label strings are no longer silenty
640 removed, but hex-encoded, to be able to uniquely identify the device
641 by its symlink in /dev/disk/by-label/.
642 If libvolume_id is used by mount(8), LABEL= will work as expected,
643 if slashes or other characters are used in the label string.
645 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
646 can be specified now. The TEST key accepts an optional mode mask
647 TEST{0100}=="<is executable file>".
649 Scsi_id now supports a mode without expecting scsi-specific sysfs
650 entries to allow the extraction of cciss-device persistent properties.
656 In the future, we may see uuid's which are just simple character
657 strings (see the DDF Raid Specification). For that reason vol_id now
658 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
659 the creation of symlinks, the *_SAFE values ensure, that no control
660 or whitespace characters are used in the filename.
662 Possible users of libvolume_id, please use the volume_id_get_* functions.
663 The public struct will go away in a future release of the library.
669 Removal of useless extras/eventrecorder.sh.
679 The directory multiplexer for dev.d/ and hotplug.d are finally removed
680 from the udev package.
686 Symlinks can have priorities now, the priority is assigned to the device
687 and specified with OPTIONS="link_priority=100". Devices with higher
688 priorities overwrite the symlinks of devices with lower priorities.
689 If the device that currently owns the link, goes away, the symlink
690 will be removed, and recreated, pointing to the next device with the
691 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
692 more reliable, if multiple devices contain the same metadata and overwrite
695 The dasd_id program is removed from the udev tree, and dasdinfo, with the
696 needed rules, are part of the s390-tools now.
698 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
699 we may get the scsi sysfs mess fixed some day, and this will only catch
700 the devices we are looking for.
702 USB serial numbers for storage devices have the target:lun now appended,
703 to make it possibble to distinguish broken multi-lun devices with all
704 the same SCSI identifiers.
706 Note: The extra "run_directory" which searches and executes stuff in
707 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
708 with the next release. Make sure, that you don't use it anymore, or
709 provides your own implementation of that inefficient stuff.
710 We are tired of reports about a "slow udev", because these directories
711 contain stuff, that runs with _every_ event, instead of using rules,
712 that run programs only for the matching events.
722 DRIVER== will match only for devices that actually have a real
723 driver. DRIVERS== must be used, if parent devices should be
724 included in the match.
726 Libvolume_id's "linux_raid" detection needed another fix.
734 Add additional check to volume_id detection of via_raid, cause
735 some company decided to put a matching pattern all over the empty
736 storage area of their music players.
740 Fix path_id for SAS devices.
744 The udev daemon can be started with --debug-trace now, which will
745 execute all events serialized to get a chance to catch a possible
746 action that crashes the box.
748 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
749 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
750 are excluded from the warning. Referencing parent attributes directly
751 may break when something in the kernel driver model changes. Udev will
752 just find the attribute by walking up the parent chain.
754 Udevtrigger now sorts the list of devices depending on the device
755 dependency, so a "usb" device is triggered after the parent "pci"
760 Revert persistent-storage ata-serial '_' '-' replacement.
766 Udevtrigger can now filter the list of devices to be triggered. Matches
767 for subsystems or sysfs attributes can be specified.
769 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
770 zero-sized files to avoid pointing to /sys and confuse broken tools which
771 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
774 The rules and scripts to create udev rules for persistent network
775 devices and optical drives are in the extras/rules_generator directory
776 now. If you use something similar, please consider replacing your own
777 version with this, to share the support effort. The rule_generator
778 installs its own rules into /etc/udev/rules.d.
780 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
781 the rule_generator depends on cdrom_id to be called in an earlier rule.
787 Renaming of some key names (the old names still work):
788 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
789 (The behavior of the key DRIVER will change soon in one of the next
790 releases, to match only the event device, please switch to DRIVERS
791 instead. If DRIVER is used, it will behave like DRIVERS, but an error
793 With the new key names, we have a more consistent and simpler scheme.
794 We can match the properties of the event device only, with: KERNEL,
795 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
796 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
797 longer mentioned in the man page and should be switched in the rule
800 ATTR{file}="value" can be used now, to write to a sysfs file of the
801 event device. Instead of:
802 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
804 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
806 All the PHYSDEV* keys are deprecated and will be removed from a
808 PHYDEVPATH - is the path of a parent device and should not be
810 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
811 matched with SUBSYSTEMS==
812 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
813 Newer kernels will have DRIVER in the environment,
814 for older kernels udev puts in. Class device will
815 no longer carry this property of a parent and
816 DRIVERS== can be used to match such a parent value.
817 Note that ENV{DRIVER} is only available for a few bus devices, where
818 the driver is already bound at device event time. On coldplug, the
819 events for a lot devices are already bound to a driver, and they will have
820 that value set. But on hotplug, at the time the kernel creates the device,
821 it can't know what driver may claim the device after that, therefore
822 in most cases it will be empty.
824 Failed events should now be re-triggered with:
825 udevtrigger --retry-failed.
826 Please switch to this command, so we keep the details of the /dev/.udev/failed/
827 files private to the udev tools. We may need to switch the current symlink
828 target, cause some obviously broken tools try to scan all files in /dev
829 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
830 million times. This takes ages on slow boxes.
832 The udevinfo attribute walk (-a) now works with giving a device node
833 name (-n) instead of a devpath (-p). The query now always works, also when
834 no database file was created by udev.
836 The built-in /etc/passwd /etc/group parser is removed, we always depend on
837 getpwnam() and getgrnam() now. One of the next releases will depend on
838 fnmatch() and may use getopt_long().
842 Bugfixes and small improvements.
846 Fix path_id for recent kernels.
852 Added support for swapping network interface names, by temporarily
853 renaming the device and wait for the target name to become free.
857 The built-in MODALIAS key and substitution is removed.
861 The binary firmware helper is replaced by the usual simple
862 shell script. Udevsend is removed from the tree.
870 Some more keys require the correct use of '==' and '=' depending
871 on the kind of operation beeing an assignment or a match. Rules
872 with invalid operations are skipped and logged to syslog. Please
873 test with udevtest if the parsing of your rules throws errors and
874 fix possibly broken rules.
878 Provide "udevsettle" to wait for all current udev events to finish.
879 It also watches the current kernel netlink queue by comparing the
880 even sequence number to make sure that there are no current pending
881 events that have not already arrived in the daemon.
885 Fix rule to skip persistent rules for removable IDE devices, which
886 also skipped optical IDE drives.
888 All *_id program are installed in /lib/udev/ by default now.
890 No binary is stripped anymore as this should be done in the
891 packaging process and not at build time.
893 libvolume_id is provided as a shared library now and vol_id is
894 linked against it. Also one of the next HAL versions will require
895 this library, and the HAL build process will also require the
896 header file to be installed. The copy of the same code in HAL will
897 be removed to have only a single copy left on the system.
901 Add persistent links for SCSI tapes. The rules file is renamed
902 to 60-persistent-storage.rules.
904 Create persistent path for usb devices. Can be used for all sorts
905 of devices that can't be distinguished by other properties like
906 multiple identical keyboards and mice connected to the same box.
908 Provide "udevtrigger" program to request events on coldplug. The
909 shell script is much too slow with thousends of devices.
913 Fix persistent disk rules to exclude removable IDE drives.
915 Warn if %e, $modalias or MODALIAS is used.
919 Fix queue export, which wasn't correct for subsequent add/remove
920 events for the same device.
924 Fix cramfs detection on big endian.
926 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
931 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
932 attributes were only checked at the parent device that matched the
933 by BUS requested subsystem. Fix it to also look at the device we
934 received the event for.
936 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
941 Fix a bug where NAME="" would prevent RUN from beeing executed.
943 RUN="/bin/program" does not longer automatically add the subsystem
944 as the first parameter. This is from the days of /sbin/hotplug
945 which is dead now and it's just confusing to need to add a space at
946 the end of the program name to prevent this.
947 If you use rules that need the subsystem as the first parameter,
948 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
949 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
953 The udev man page has moved to udev(7) as it does not describe a command
954 anymore. The programs udev, udevstart and udevsend are no longer installed
955 by default and must be copied manually, if they should be installed or
956 included in a package.
958 Fix a bug where "ignore_device" could run earlier collected RUN keys before
959 the ignore rule was applied.
961 More preparation for future sysfs changes. usb_id and scsi_id no longer
962 depend on a magic order of devices in the /devices chain. Specific devices
963 should be requested by their subsytem.
965 This will always find the scsi parent device without depending on a specific
967 dev = sysfs_device_get(devpath);
968 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
970 The "device" link in the current sysfs layout will be automatically
971 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
972 parent in the devpath. If a device is requested by it's symlink, like all
973 class devices in the new sysfs layout will look like, it gets automatically
974 resolved and substituted with the real devpath and not the symlink path.
977 A similar logic must be applied to _all_ sysfs users, including
978 scripts, that search along parent devices in sysfs. The explicit use of
979 the "device" link must be avoided. With the future sysfs layout all
980 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
981 back to the "class" or the "bus". The layout of the parent devices in
982 /devices is not necessarily expected to be stable across kernel releases and
983 searching for parents by their subsystem should make sysfs users tolerant
984 for changed parent chains.
988 Prepare udev to work with the experimental kernel patch, that moves
989 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
991 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
992 moving the class devices to /sys/devices.
994 Thanks again to Marco for help finding a hopefully nice compromise
995 to make %b simpler and working again.
999 Complete removal of libsysfs, replaced by simple helper functions
1000 which are much simpler and a bit faster. The udev daemon operatesentirely
1001 on event parameters and does not use sysfs for simple rules anymore.
1002 Please report any new bugs/problems, that may be caused by this big
1003 change. They will be fixed immediately.
1005 The enumeration format character '%e' is deprecated and will be
1006 removed sometimes from a future udev version. It never worked correctly
1007 outside of udevstart, so we can't use it with the new parallel
1008 coldplug. A simple enumeration is as useless as the devfs naming
1009 scheme, just get rid of both if you still use it.
1011 MODALIAS and $modalias is not needed and will be removed from one of
1012 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1013 the sysfs "modalias" value.
1015 Thanks a lot to Marco for all his help on finding and fixing bugs.
1019 Let scsi_id request libata drive serial numbers from page 0x80.
1021 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1022 added /dev/disk/by-name/* for device mapper device names.
1024 Removed %e from the man page. It never worked reliably outside
1025 of udevstart and udevstart is no longer recommended to use.
1029 Symlinks are now exported to the event environment. Hopefully it's no
1030 longer needed to run udevinfo from an event process, like it was
1031 mentioned on the hotplug list:
1032 UDEV [1134776873.702967] add@/block/sdb
1035 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1039 Fix a problem if udevsend is used as the hotplug handler and tries to use
1040 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1041 and this kind of problems will hopefully go away soon.
1045 All built-in logic to work around bad sysfs timing is removed with this
1046 version. The need to wait for sysfs files is almost fixed with a kernel
1047 version that doesn't work with this udev version anyway. Until we fix
1048 the timing of the "bus" link creation, the former integrated logic should
1049 be emulated by a rule placed before all other rules:
1050 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1052 The option "udev_db" does no longer exist. All udev state will be in
1053 /$udev_root/.udev/ now, there is no longer an option to set this
1055 If the init script or something else used this value, just depend on
1056 this hardcoded path. But remember _all_content_ of this directory is
1057 still private to udev and can change at any time.
1059 Default location for rule sripts and helper programs is now: /lib/udev/.
1060 Everything that is not useful on the commandline should go into this
1061 directory. Some of the helpers in the extras folder are installed there
1062 now. The rules need to be changed, to find the helpers there.
1064 Also /lib/udev/devices is recommended as a directory where packages or
1065 the user can place real device nodes, which get copied over to /dev at
1066 every boot. This should replace the various solutions with custom config
1069 Udevsend does no longer start the udev daemon. This must be done with
1070 the init script that prepares /dev on tmpfs and creates the initial nodes,
1071 before starting the daemon.
1075 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1078 The copy of klibc is removed. A systemwide installed version of klibc
1079 should be used to build a klibc udev now.
1083 NAME="" will not create any nodes, but execute RUN keys. To completely
1084 ignore an event the OPTION "ignore_device" should be used.
1086 After removal of the reorder queue, events with a TIMEOUT can be executed
1087 without any queuing now.
1091 Fixed bug in udevd, if inotify is not available. We depend on netlink
1092 uevents now, kernels without that event source will not work with that
1093 version of udev anymore.
1097 The rule parsing happens now in the daemon once at startup, all udev
1098 event processes inherit the already parsed rules from the daemon.
1099 It is shipped with SUSE10.0 and reduces heavily the system load at
1100 startup. The option to save precompiled rules and let the udev process
1101 pick the them up is removed, as it's no longer needed.
1103 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1104 device. Libsysfs is changed to "translate" the requested link into the
1105 real device path, as it would happen with the hotplug event. Otherwise
1106 device removal and the udev database will not work.
1108 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1111 A few improvements for vol_id, the filesytem probing code.
1115 Fix a stupid typo in extras/run_directory for "make install".
1117 scsi_id creates the temporary devnode now in /dev for usage with a
1118 non-writable /tmp directory.
1120 The uevent kernel socket buffer can carry app. 50.000 events now,
1121 let's see who can break this again. :)
1123 The upcoming kernel will have a new input driver core integration.
1124 Some class devices are now symlinks to the real device. libsysfs
1125 needs a fix for this to work correctly. Udevstart of older udev
1126 versions will _not_ create these devices!
1130 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1135 A bunch of mostly trivial bugfixes. From now on no node name or
1136 symlink name can contain any character than plain whitelisted ascii
1137 characters or validated utf8 byte-streams. This is needed for the
1138 /dev/disk/by-label/* links, because we import untrusted data and
1139 export it to the filesystem.
1143 More bugfixes. If udevd was started from the kernel, we don't
1144 have stdin/stdout/stderr, which broke the forked tools in some
1149 Bugfix. udevstart event ordering was broken for a long time.
1150 The new run_program() uncovered it, because /dev/null was not
1151 available while we try to run external programs.
1152 Now udevstart should create it before we run anything.
1156 Minor bugfixes and some distro rules updates. If you don't have the
1157 persistent disk rules in /dev/disk/by-*/* on your distro, just
1158 grab it from here. :)
1162 We can use socket communication now to pass events from udev to
1164 RUN+="socket:/org/freedesktop/hal/udev_event"
1165 will pass the whole udev event to the HAL daemon without the need
1166 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1170 Mostly bugfixes and see ChangeLog.
1172 The test for the existence of an environment value should be
1174 ENV{KEY}=="*" to ENV{KEY}=="?*"
1175 because "*" will not fail anymore, if the key does not exist or
1180 Bugfixes and a few tweaks described in the ChangeLog.
1184 Mostly a Bugfix release.
1186 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1187 timing with custom rules.
1191 We changed the internal rule storage format. Our large rule files took
1192 2 MB of RAM, with the change we are down to 99kB.
1194 If the device-node has been created with default name and no symlink or
1195 options are to remenber, it is not longer stored in the udevdb. HAL will
1196 need to be updated to work correctly with that change.
1198 To overrride optimization flags, OPTFLAGS may be used now.
1206 Major changes happened with this release. The goal is to take over the
1207 complete kernel-event handling and provide a more efficient way to dispatch
1208 kernel events. Replacing most of the current shell script logic and the
1209 kernel forked helper with a netlink-daemon and a rule-based event handling.
1211 o udevd listens to netlink events now. The first valid netlink event
1212 will make udevd ignore any message from udevsend that contains a
1213 SEQNUM, to avoid duplicate events. The forked events can be disabled
1215 echo "" > /proc/sys/kernel/hotplug
1216 For full support, the broken input-subsytem needs to be fixed, not to
1217 bypass the driver core.
1219 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1220 removed from udev itself and must be emulated by calling small
1221 helper binaries provided in the extras folder:
1222 make EXTRAS=extras/run_directory/
1223 will build udev_run_devd and udev_run_hotplugd, which can be called
1224 from a rule if needed:
1225 RUN+="/sbin/udev_run_hotplugd"
1226 The recommended way to handle this is to convert all the calls from
1227 the directories to explicit udev rules and get completely rid of the
1228 multiplexing. (To catch a ttyUSB event, you now no longer need to
1229 fork and exit 300 tty script instances you are not interested in, it
1230 is just one rule that matches exactly the device.)
1232 o udev handles now _all_ events not just events for class and block
1233 devices, this way it is possible to control the complete event
1234 behavior with udev rules. Especially useful for rules like:
1235 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1237 o As used in the modalias rule, udev supports now textual
1238 substitution placeholder along with the usual format chars. This
1239 needs to be documented, for now it's only visible in udev_rules_parse.c.
1241 o The rule keys support now more operations. This is documented in the
1242 man page. It is possible to add values to list-keys like the SYMLINK
1243 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1244 Also "final"-assignments are supported by using KEY:="value", which will
1245 prevent changing the key by any later rule.
1247 o kernel 2.6.12 has the "detached_state" attribute removed from
1248 sysfs, which was used to recognize sysfs population. We switched that
1249 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1250 Running this udev version on older kernels may cause a short delay for
1253 o To provide infrastructure for persistent device naming, the id programs:
1254 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1255 to export the probed data in environment key format:
1256 pim:~ # /sbin/ata_id --export /dev/hda
1257 ID_MODEL=HTS726060M9AT00
1258 ID_SERIAL=MRH401M4G6UM9B
1259 ID_REVISION=MH4OA6BA
1261 The following rules:
1262 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1263 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1266 kay@pim:~> tree /dev/disk
1269 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1270 | `-- IBM-Memory_Key -> ../../sda
1272 | |-- swap -> ../../hda1
1273 | |-- date -> ../../sda1
1274 | `-- home -> ../../hda3
1276 |-- 2E08712B0870F2E7 -> ../../hda3
1277 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1278 |-- E845-7A89 -> ../../sda1
1279 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1281 The IMPORT= operation will import these keys in the environment and make
1282 it available for later PROGRAM= and RUN= executed programs. The keys are
1283 also stored in the udevdb and can be queried from there with one of the
1286 o A few binaries are silently added to the repository, which can be used
1287 to replay kernel events from initramfs instead of using coldplug. udevd
1288 can be instructed now to queue-up events while the stored events from
1289 initramfs are filled into the udevd-queue. This code is still under
1290 development and there is no documentation now besides the code itself.
1291 The additional binaries get compiled, but are not installed by default.
1293 o There is also a temporary fix for a performance problem where too many
1294 events happen in parallel and every event needs to parse the rules.
1295 udev can now read precompiled rules stored on disk. This is likely to be
1296 replaced by a more elegant solution in a future udev version.
1300 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1301 Fix for libsysfs not to expect this file was added.
1305 All rules are applied now, but only the first matching rule with a NAME-key
1306 will be applied. All later rules with NAME-key are completely ignored. This
1307 way system supplied symlinks or permissions gets applied to user-defined
1311 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1312 to some rules, to keep the old behavior.
1314 The rules are read on "remove"-events too. That makes is possible to match
1315 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1316 instruct udev to ignore an event (OPTIONS="ignore_device").
1317 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1319 The new RUN-key supports rule-based execution of programs after device-node
1320 handling. This is meant as a general replacement for the dev.d/-directories
1321 to give fine grained control over the execution of programs.
1323 The %s{}-sysfs format char replacement values are searched at any of the
1324 devices in the device chain now, not only at the class-device.
1326 We support log priority levels now. The value udev_log in udev.conf is used
1327 to determine what is printed to syslog. This makes it possible to
1328 run a version with compiled-in debug messages in a production environment
1329 which is sometimes needed to find a bug.
1330 It is still possible to supress the inclusion of _any_ syslog usage with
1331 USE_LOG=false to create the smallest possible binaries if needed.
1332 The configured udev_log value can be overridden with the environment variable
1337 Possible use of a system-wide klibc:
1338 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1339 will link against an external klibc and our own version will be ignored.
1343 We support an unlimited count of symlinks now.
1345 If USE_STATIC=true is passed to a glibc build, we link statically and use
1346 a built-in userdb parser to resolve user and group names.
1348 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1349 we walk up the chain of physical devices to find a match.
1351 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1352 easy to skip certain attribute matches without composing rules with weird
1353 character class negations like:
1354 KERNEL="[!s][!c][!d]*"
1355 this can now be replaced with:
1357 The current simple '=' is still supported, and should work as it does today,
1358 but existing rules should be converted if possible, to be better readable.
1360 We have new ENV{}== key now, to match against a maximum of 5 environment
1363 udevstart is its own binary again, because we don't need co carry this araound
1364 with every forked event.