5 The udev runtime data moved from /dev/.udev/ to /dev/.run/udev/.
6 On systemd systems the tmpfs mountpoint /var/run/ will have a
7 permanent "early-boot alias" /dev/.run/, where udev and a couple
8 of other early-boot tools will put their runtime data.
10 On systemd systems with LVM used, packagers must make sure, that
11 the systemd and initramfs version match. The initramfs needs to
12 create the /dev/.run/ mountpoint for udev to store the data, so
13 that systemd will not overmount it, which would make the udev
14 data from initramfs invisible.
16 The command 'udevadm info --convert-db' is gone. The udev daemon
17 itself, at startup, converts any old database version if necessary.
23 New and updated keymaps.
29 The udev database has changed, After installation of a new udev
30 version, 'udevadm info --convert-db' should be called, to let the new
31 udev/libudev version read the already stored data.
33 udevadm now supports quoting of property values, and prefixing of
35 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
43 udev_device_get_is_initialized()
44 udev_enumerate_add_match_is_initialized()
45 to be able to skip devices the kernel has created , but udev has
49 udev_device_get_usec_since_initialized()
50 to retrieve the "age" of a udev device record.
52 GUdev supports a more generic GUdevEnumerator class, udev TAG
53 handling, device initialization and timestamp now.
55 The counterpart of /sys/dev/{char,block}/$major:$minor,
56 /dev/{char,block}/$major:$minor symlinks are now unconditionally
57 created, even when no rule files exist.
59 New and updated keymaps.
65 GUdev moved from /usr to /.
75 Persistent network naming rules are disabled inside of Qemu/KVM now.
77 New and updated keymaps.
79 Udev gets unconditionally enabled on systemd installations now. There
80 is no longer the need to to run 'systemctl enable udev.service'.
94 New and fixed keymaps.
96 Install systemd service files if applicable.
102 All distribution specific rules are removed from the udev source tree,
103 most of them are no longer needed. The Gentoo rules which allow to support
104 older kernel versions, which are not covered by the default rules anymore
105 has moved to rules/misc/30-kernel-compat.rules.
111 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
112 was removed from udevd.
114 Udevd now checks the kernel commandline for the following variables:
115 udev.log-priority=<syslog priority>
116 udev.children-max=<maximum number of workers>
117 udev.exec-delay=<seconds to delay the execution of RUN=>
118 to help debuging coldplug setups where the loading of a kernel
119 module crashes the system.
121 The subdirectory in the source tree rules/packages has been renamed to
122 rules/arch, anc contains only architecture specific rules now.
132 Now the udev daemon itself, does on startup:
133 - copy the content of /lib/udev/devices to /dev
134 - create the standard symlinks like /dev/std{in,out,err},
135 /dev/core, /dev/fd, ...
136 - use static node information provided by kernel modules
137 and creates these nodes to allow module on-demand loading
138 - possibly apply permissions to all ststic nodes from udev
139 rules which are annotated to match a static node
141 The default mode for a device node is 0600 now to match the kernel
142 created devtmpfs defaults. If GROUP= is specified and no MODE= is
143 given the default will be 0660.
149 Udev now gradually starts to pass control over the primary device nodes
150 and their names to the kernel, and will in the end only manage the
151 permissions of the node, and possibly create additional symlinks.
152 As a first step NAME="" will be ignored, and NAME= setings with names
153 other than the kernel provided name will result in a logged warning.
154 Kernels that don't provide device names, or devtmpfs is not used, will
155 still work as they did before, but it is strongly recommended to use
156 only the same names for the primary device node as the recent kernel
157 provides for all devices.
161 Fix broken firmware loader search path.
167 "udevadm trigger" defaults to "change" events now instead of "add"
168 events. The "udev boot script" might need to add "--action=add" to
169 the trigger command if not already there, in case the initial coldplug
170 events are expected as "add" events.
172 The option "all_partitons" was removed from udev. This should not be
173 needed for usual hardware. Udev can not safely make assumptions
174 about non-existing partition major/minor numbers, and therefore no
175 longer provide this unreliable and unsafe option.
177 The option "ignore_remove" was removed from udev. With devtmpfs
178 udev passed control over device nodes to the kernel. This option
179 should not be needed, or can not work as advertised. Neither
180 udev nor the kernel will remove device nodes which are copied from
181 the /lib/udev/devices/ directory.
183 All "add|change" matches are replaced by "!remove" in the rules and
184 in the udev logic. All types of events will update possible symlinks
185 and permissions, only "remove" is handled special now.
187 The modem modeswitch extra was removed and the external usb_modeswitch
188 program should be used instead.
190 New and fixed keymaps.
200 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
201 depend on the current sysfs layout and the information not available in the
202 deprecated layout. All remaining support for the deprecated sysfs layout is
207 Fix for a possible endless loop in the new input_id program.
213 The option "ignore_device" does no longer exist. There is no way to
214 ignore an event, as libudev events can not be suppressed by rules.
215 It only prevented RUN keys from being executed, which results in an
216 inconsistent behavior in current setups.
218 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
219 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
222 The support for the deprecated IDE devices has been removed from the
223 default set of rules. Distros who still care about non-libata drivers
224 need to add the rules to the compat rules file.
226 The ID_CLASS property on input devices has been replaced by the more accurate
227 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
228 determined by the new "input_id" prober now. Some devices, such as touchpads,
229 can have several classes. So if you previously had custom udev rules which e. g.
230 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
231 ENV{ID_INPUT_KEYBOARD}=="?*".
237 To support DEVPATH strings larger than the maximum file name length, the
238 private udev database format has changed. If some software still reads the
239 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
240 Please do not port anything to the new format again, everything in /dev/.udev
241 is and always was private to udev, and may and will change any time without
244 Multiple devices claiming the same names in /dev are limited to symlinks
245 only now. Mixing identical symlink names and node names is not supported.
246 This reduces the amount of data in the database significantly.
248 NAME="%k" causes a warning now. It's is and always was completely superfluous.
249 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
252 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
253 if they are not the default. To support older kernels, the NAME= rules need to
254 be added to the compat rules file.
256 Symlinks to udevadm with the old command names are no longer resolved to
257 the udevadm commands.
259 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
262 The option "last_rule" does no longer exist. Its use breaks too many
263 things which expect to be run from independent later rules, and is an idication
264 that something needs to be fixed properly instead.
266 The gudev API is no longer marked as experimental,
267 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
268 is enabled by default now. Various projects already depend on introspection
269 information to bind dynamic languages to the gudev interfaces.
275 The udevadm trigger "--retry-failed" option, which is replaced since quite
276 a while by "--type=failed" is removed.
278 The failed tracking was not working at all for a few releases. The RUN
279 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
280 default is not to track any failing RUN executions.
282 New keymaps, new modem, hid2hci updated.
286 Fix possible crash in udevd when worker processes are busy, rules are
287 changed at the same time, and workers get killed to reload the rules.
293 Properties set with ENV{.FOO}="bar" are marked private by starting the
294 name with a '.'. They will not be stored in the database, and not be
295 exported with the event.
297 Firmware files are looked up in:
298 /lib/firmware/updates/$(uname -r)
299 /lib/firmware/updates
300 /lib/firmware/$(uname -r)
304 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
305 ata_id, instead of scsi_id, is the default tool now for ATA devices.
311 The configure options have changed because another library needs to be
312 installed in a different location. Instead of exec_prefix and udev_prefix,
313 libdir, rootlibdir and libexecdir are used. The Details are explained in
316 Event processes now get re-used after they handled an event. This reduces
317 the number of forks and the pressure on the CPU significantly, because
318 cloned event processes no longer cause page faults in the main daemon.
319 After the events have settled, a few worker processes stay around for
320 future events, all others get cleaned up.
322 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
323 Also inotify support is mandatory now to run udev.
325 The format of the queue exported by the udev damon has changed. There is
326 no longer a /dev/.udev/queue/ directory. The current event queue can be
327 accessed with udevadm settle and libudedv.
329 Libudev does not have the unstable API header anymore. From now on,
330 incompatible changes will be handled by bumping the library major version.
332 To build udev from the git tree gtk-doc is needed now. The tarballs will
333 build without it and contain the pre-built documentation. An online copy
335 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
337 The tools from the udev-extras repository have been merged into the main
338 udev repository. Some of the extras have larger external dependencies, and
339 they can be disabled with the configure switch --disable-extras.
345 The program vol_id and the library libvolume_id are removed from the
346 repository. Libvolume_id is merged with libblkid from the util-linux-ng
347 package. Persistent disk links for label and uuid depend on the
348 util-linux-ng version (2.15) of blkid now. Older versions of blkid
349 can not be used with udev.
351 Libudev allows to subscribe to udev events. To prevent unwanted messages
352 to be delivered, and waking up the subscribing process, a filter can be
353 installed, to drop messages inside a kernel socket filter. The filters
354 match on the <subsytem>:<devtype> properties of the device.
355 This is part of the ongoing effort to replace HAL, and switch current
356 users over to directly use libudev.
357 Libudev is still marked as experimental, and its interface might
358 eventually change if needed, but no major changes of the currently exported
359 interface are expected anymore, and a first stable release should happen
362 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
363 is not supported since while and udevd will log an error message at
364 startup. It should still be able to boot-up, but advanced rules and system
365 services which depend on the information not available in the old sysfs
366 format will fail to work correctly.
368 DVB device naming is supplied by the kernel now. In case older kernels
369 need to be supported, the old shell script should be added to a compat
376 The processed udev events get send back to the netlink socket. Libudev
377 provides access to these events. This is work-in-progress, to replace
378 the DeviceKit daemon functionality directly with libudev. There are
379 upcoming kernel changes to allow non-root users to subcribe to these
386 "udevadm settle" now optionally accepts a range of events to wait for,
387 instead of waiting for "all" events.
393 The installed watch for block device metadata changes is now removed
394 during event hadling, because some (broken) tools may be called from udev
395 rules and (wrongly) open the device with write access. After the finished
396 event handling the watch is restored.
402 Device nodes can be watched for changes with inotify with OPTIONS="watch".
403 If closed after being opened for writing, a "change" uevent will occur.
404 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
410 The udevadm test command has no longer a --force option, nodes and symlinks
411 are always updated with a test run now.
413 The udevd daemon can be started with --resolve-names=never to avoid all user
414 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
415 lookup user and groups every time events are handled.
421 We are currently merging the Ubuntu rules in the udev default rules,
422 and get one step closer to provide a common Linux /dev setup, regarding
423 device names, symlinks, and default device permissions. On udev startup,
424 we now expect the following groups to be resolvable to their ids with
426 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
427 LDAP setups need to make sure, that these groups are always resolvable at
428 bootup, with only the rootfs mounted, and without network access available.
430 Some systems may need to add some new, currently not used groups, or need
431 to add some users to new groups, but the cost of this change is minimal,
432 compared to the pain the current, rather random, differences between the
433 various distributions cause for upstream projects and third-party vendors.
435 In general, "normal" users who log into a machine should never be a member
436 of any such group, but the device-access should be managed by dynamic ACLs,
437 which get added and removed for the specific users on login/logout and
438 session activity/inactivity. These groups are only provided for custom setups,
439 and mainly system services, to allow proper privilege separation.
440 A video-streaming daemon uid would be a member of "audio" and "video", to get
441 access to the sound and video devices, but no "normal" user should ever belong
442 to the "audio" group, because he could listen to the built-in microphone with
443 any ssh-session established from the other side of the world.
445 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
446 which do not depend on the kernel device name. As usual, unique
447 devices - only a single one per product connected, or a real
448 USB serial number in the device - are always found with the same
449 name in the by-id/ directory.
450 Completely identical devices may overwrite their names in by-id/
451 and can only be found reliably in the by-path/ directory. Devices
452 specified by by-path/ must not change their connection, like the
453 USB port number they are plugged in, to keep their name.
455 To support some advanced features, Linux 2.6.22 is the oldest supported
456 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
457 supported. Older kernels should still work, and devices nodes should be
458 reliably created, but some rules and libudev will not work correctly because
459 the old kernels do not provide the expected information or interfaces.
465 Fix for a possible segfault while swapping network interface names in udev
472 The group "video" is part of the default rules now.
476 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
477 block devices in some cases. No common distro uses this option anymore,
478 and we do not get enough testing for this and recent udev versions. If
479 this option is not needed to run some old distro with a new kernel,
480 it should be disabled in the kernel config.
482 Bugfix for the $links substitution variable, which may crash if no links
483 are created. This should not happen in usual setups because we always
484 create /dev/{block,char}/ links.
486 The strings of the parsed rules, which are kept in memory, no longer
487 contain duplicate entries, or duplicate tails of strings. This, and the
488 new rules parsing/matching code reduces the total in-memory size of
489 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
492 The export of DEVTYPE=disk/partition got removed from the default
493 rules. This value is available from the kernel. The pnp shell script
494 modprobe hack is removed from the default rules. ACPI devices have _proper_
495 modalias support and take care of the same functionality.
496 Installations which support old kernels, but install current default
497 udev rules may want to add that to the compat rules file.
499 Libvolume_id now always probes for all known filesystems, and does not
500 stop at the first match. Some filesystems are marked as "exclusive probe",
501 and if any other filesytem type matches at the same time, libvolume_id
502 will, by default, not return any probing result. This is intended to prevent
503 mis-detection with conflicting left-over signatures found from earlier
504 file system formats. That way, we no longer depend on the probe-order
505 in case of multiple competing signatures. In some setups the kernel allows
506 to mount a volume with just the old filesystem signature still in place.
507 This may damage the new filesystem and cause data-loss, just by mounting
508 it. Because volume_id can not decide which one the correct signature is,
509 the wrong signatures need to be removed manually from the volume, or the
510 volume needs to be reformatted, to enable filesystem detection and possible
515 Fix segfault if compiled without optimization and dbg() does not get
516 compiled out and uses variables which are not available.
520 Bugfixes. (And maybe new bugs. :))
522 The rule matching engine got converted from a rule list to a token
523 array which reduced the in-memory rules representation of a full
524 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
525 Limits like 5 ENV and ATTR matches, and one single instance for most
526 other keys per rule are gone.
528 The NAME assignment is no longer special cased. If later rules assign
529 a NAME value again, the former value will be overwritten. As usual
530 for most other keys, the NAME value can be protected by doing a final
531 assignment with NAME:="<value>".
533 All udev code now uses libudev, which is also exported. The library
534 is still under development, marked as experimental, and its interface
535 may change as long as the DeviceKit integration is not finished.
537 Many thanks to Alan Jenkins for his continuous help, and finding and
538 optimizing some of the computing expensive parts.
544 Kernel devices and device nodes are connected now by reverse indizes in
545 /sys and /dev. A device number retrieved by a stat() or similar, the
546 kernel device directory can be found by looking up:
547 /sys/dev/{block,char}/<maj>:<min>
548 and the device node of the same device by looking up:
549 /dev/{block,char}/<maj>:<min>
553 Fix recently introduced bug, which caused a compilation without large
554 file support, where vol_id does not recognize raid signatures at the end
557 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
558 Seems some kernel versions prevent the creation of the ieee-* links,
559 so people used the scsi-* link which disappeared now.
561 More libudev work. Almost all udevadm functionality comes from libudev
564 udevadm trigger has a new option --type, which allows to trigger events
565 for "devices", for "subsystems", or "failed" devices. The old option
566 --retry-failed" still works, but is no longer mentioned in the man page.
572 The udevadm info --device-id-of-file= output has changed to use
573 the obvious format. Possible current users should use the --export
574 option which is not affected.
576 The old udev commands symlinks to udevadm are not installed, if
577 these symlinks are used, a warning is printed.
583 Optical drive's media is no longer probed for raid signatures,
584 reading the end of the device causes some devices to malfunction.
585 Also the offset of the last session found is used now to probe
588 The volume_id library got a major version number update to 1,
589 some deprecated functions are removed.
591 A shared library "libudev" gets installed now to provide access
592 to udev device information. DeviceKit, the successor of HAL, will
593 need this library to access the udev database and search sysfs for
595 The library is currently in an experimental state, also the API is
596 expected to change, as long as the DeviceKit integration is not
601 We use ./configure now. See INSTALL for details. Current
604 "/usr" - prefix for man pages, include files
606 "" - the root filesystem, prefix for libs and binaries
610 "lib" - directory name for libraries, not a path name
611 multilib 64bit systems may use "lib64" instead of "lib"
613 compile-in verbose debug messages
615 disable all logging and compile-out all log strings
617 link against SELInux libraries, to set the expected context
620 In the default rules, the group "disk" gets permissions 0660 instead
621 of 0640. One small step closer to unify distro rules. Some day, all
622 distros hopefully end up with the same set of rules.
624 No symlinks to udevadm are installed anymore, if they are still needed,
625 they should be provided by the package.
631 Default udev rules, which are not supposed to be edited by the user, should
632 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
633 the udev package and will be replaced with an update. Udev will pick up rule
635 /lib/udev/rules.d/ - default installed rules
636 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
637 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
638 It does not matter in which directory a rule file lives, all files are sorted
641 To help creating /dev/root, we have now:
642 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
645 In case the current --device-id-of-file is already used, please switch to
646 the --export format version, it saves the output parsing and the old
647 format will be changed to use ':' as a separator, like the format in the
652 Fix cdrom_id to properly recognize blank media.
658 Tape drive id-data is queried from /dev/bsg/* instead of the tape
659 nodes. This avoids rewinding tapes on open().
665 The symlinks udevcontrol and udevtrigger are no longer installed by
668 The scsi_id program does not depend on sysfs anymore. It can speak
669 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
670 data, which should solve some old problems with tape devices, where
671 we better do not open all tape device nodes to identify the device.
677 The cdrom_id program is replaced by an advanced version, which can
678 detect most common device types, and also properties of the inserted
679 media. This is part of moving some basic functionality from HAL into
680 udev (and the kernel).
686 The last WAIT_FOR_SYSFS rule is removed from the default rules.
688 The symlinks to udevadm for the debugging tools: udevmonitor and
689 udevtest are no longer created.
691 The symlinks to the udevadm man page for the old tool names are
694 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
695 should be prefixed with '@' to indicate that the path is not a
706 Udevstart is removed from the tree, it did not get installed for
707 a long time now, and is long replaced by trigger and settle.
713 All udev tools are merged into a single binary called udevadm.
714 The old names of the tools are built-in commands in udevadm now.
715 Symlinks to udevadm, with the names of the old tools, provide
716 the same functionality as the standalone tools. There is also
717 only a single udevadm.8 man page left for all tools.
719 Tools like mkinitramfs should be checked, if they need to include
720 udevadm in the list of files.
730 The etc/udev/rules.d/ directory now contains a default set of basic
731 udev rules. This initial version is the result of a rules file merge
732 of Fedora and openSUSE. For these both distros only a few specific
733 rules are left in their own file, named after the distro. Rules which
734 are optionally installed, because they are only valid for a specific
735 architecture, or rules for subsystems which are not always used are
736 in etc/udev/packages/.
742 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
743 actions by dynamically created rules.
745 SYMLINK=="<value>" matches agains the entries in the list of
746 currently defined symlinks. The links are not created in the
747 filesystem at that point in time, but the values can be matched.
749 RUN{ignore_error}+="<program>" will ignore any exit code from the
750 program and not record as a failed event.
756 Final merge of patches/features from the Ubuntu package.
762 Control characters in filesystem label strings are no longer silenty
763 removed, but hex-encoded, to be able to uniquely identify the device
764 by its symlink in /dev/disk/by-label/.
765 If libvolume_id is used by mount(8), LABEL= will work as expected,
766 if slashes or other characters are used in the label string.
768 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
769 can be specified now. The TEST key accepts an optional mode mask
770 TEST{0100}=="<is executable file>".
772 Scsi_id now supports a mode without expecting scsi-specific sysfs
773 entries to allow the extraction of cciss-device persistent properties.
779 In the future, we may see uuid's which are just simple character
780 strings (see the DDF Raid Specification). For that reason vol_id now
781 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
782 the creation of symlinks, the *_SAFE values ensure, that no control
783 or whitespace characters are used in the filename.
785 Possible users of libvolume_id, please use the volume_id_get_* functions.
786 The public struct will go away in a future release of the library.
792 Removal of useless extras/eventrecorder.sh.
802 The directory multiplexer for dev.d/ and hotplug.d are finally removed
803 from the udev package.
809 Symlinks can have priorities now, the priority is assigned to the device
810 and specified with OPTIONS="link_priority=100". Devices with higher
811 priorities overwrite the symlinks of devices with lower priorities.
812 If the device that currently owns the link, goes away, the symlink
813 will be removed, and recreated, pointing to the next device with the
814 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
815 more reliable, if multiple devices contain the same metadata and overwrite
818 The dasd_id program is removed from the udev tree, and dasdinfo, with the
819 needed rules, are part of the s390-tools now.
821 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
822 we may get the scsi sysfs mess fixed some day, and this will only catch
823 the devices we are looking for.
825 USB serial numbers for storage devices have the target:lun now appended,
826 to make it possibble to distinguish broken multi-lun devices with all
827 the same SCSI identifiers.
829 Note: The extra "run_directory" which searches and executes stuff in
830 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
831 with the next release. Make sure, that you don't use it anymore, or
832 provides your own implementation of that inefficient stuff.
833 We are tired of reports about a "slow udev", because these directories
834 contain stuff, that runs with _every_ event, instead of using rules,
835 that run programs only for the matching events.
845 DRIVER== will match only for devices that actually have a real
846 driver. DRIVERS== must be used, if parent devices should be
847 included in the match.
849 Libvolume_id's "linux_raid" detection needed another fix.
857 Add additional check to volume_id detection of via_raid, cause
858 some company decided to put a matching pattern all over the empty
859 storage area of their music players.
863 Fix path_id for SAS devices.
867 The udev daemon can be started with --debug-trace now, which will
868 execute all events serialized to get a chance to catch a possible
869 action that crashes the box.
871 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
872 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
873 are excluded from the warning. Referencing parent attributes directly
874 may break when something in the kernel driver model changes. Udev will
875 just find the attribute by walking up the parent chain.
877 Udevtrigger now sorts the list of devices depending on the device
878 dependency, so a "usb" device is triggered after the parent "pci"
883 Revert persistent-storage ata-serial '_' '-' replacement.
889 Udevtrigger can now filter the list of devices to be triggered. Matches
890 for subsystems or sysfs attributes can be specified.
892 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
893 zero-sized files to avoid pointing to /sys and confuse broken tools which
894 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
897 The rules and scripts to create udev rules for persistent network
898 devices and optical drives are in the extras/rules_generator directory
899 now. If you use something similar, please consider replacing your own
900 version with this, to share the support effort. The rule_generator
901 installs its own rules into /etc/udev/rules.d.
903 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
904 the rule_generator depends on cdrom_id to be called in an earlier rule.
910 Renaming of some key names (the old names still work):
911 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
912 (The behavior of the key DRIVER will change soon in one of the next
913 releases, to match only the event device, please switch to DRIVERS
914 instead. If DRIVER is used, it will behave like DRIVERS, but an error
916 With the new key names, we have a more consistent and simpler scheme.
917 We can match the properties of the event device only, with: KERNEL,
918 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
919 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
920 longer mentioned in the man page and should be switched in the rule
923 ATTR{file}="value" can be used now, to write to a sysfs file of the
924 event device. Instead of:
925 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
927 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
929 All the PHYSDEV* keys are deprecated and will be removed from a
931 PHYDEVPATH - is the path of a parent device and should not be
933 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
934 matched with SUBSYSTEMS==
935 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
936 Newer kernels will have DRIVER in the environment,
937 for older kernels udev puts in. Class device will
938 no longer carry this property of a parent and
939 DRIVERS== can be used to match such a parent value.
940 Note that ENV{DRIVER} is only available for a few bus devices, where
941 the driver is already bound at device event time. On coldplug, the
942 events for a lot devices are already bound to a driver, and they will have
943 that value set. But on hotplug, at the time the kernel creates the device,
944 it can't know what driver may claim the device after that, therefore
945 in most cases it will be empty.
947 Failed events should now be re-triggered with:
948 udevtrigger --retry-failed.
949 Please switch to this command, so we keep the details of the /dev/.udev/failed/
950 files private to the udev tools. We may need to switch the current symlink
951 target, cause some obviously broken tools try to scan all files in /dev
952 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
953 million times. This takes ages on slow boxes.
955 The udevinfo attribute walk (-a) now works with giving a device node
956 name (-n) instead of a devpath (-p). The query now always works, also when
957 no database file was created by udev.
959 The built-in /etc/passwd /etc/group parser is removed, we always depend on
960 getpwnam() and getgrnam() now. One of the next releases will depend on
961 fnmatch() and may use getopt_long().
965 Bugfixes and small improvements.
969 Fix path_id for recent kernels.
975 Added support for swapping network interface names, by temporarily
976 renaming the device and wait for the target name to become free.
980 The built-in MODALIAS key and substitution is removed.
984 The binary firmware helper is replaced by the usual simple
985 shell script. Udevsend is removed from the tree.
993 Some more keys require the correct use of '==' and '=' depending
994 on the kind of operation beeing an assignment or a match. Rules
995 with invalid operations are skipped and logged to syslog. Please
996 test with udevtest if the parsing of your rules throws errors and
997 fix possibly broken rules.
1001 Provide "udevsettle" to wait for all current udev events to finish.
1002 It also watches the current kernel netlink queue by comparing the
1003 even sequence number to make sure that there are no current pending
1004 events that have not already arrived in the daemon.
1008 Fix rule to skip persistent rules for removable IDE devices, which
1009 also skipped optical IDE drives.
1011 All *_id program are installed in /lib/udev/ by default now.
1013 No binary is stripped anymore as this should be done in the
1014 packaging process and not at build time.
1016 libvolume_id is provided as a shared library now and vol_id is
1017 linked against it. Also one of the next HAL versions will require
1018 this library, and the HAL build process will also require the
1019 header file to be installed. The copy of the same code in HAL will
1020 be removed to have only a single copy left on the system.
1024 Add persistent links for SCSI tapes. The rules file is renamed
1025 to 60-persistent-storage.rules.
1027 Create persistent path for usb devices. Can be used for all sorts
1028 of devices that can't be distinguished by other properties like
1029 multiple identical keyboards and mice connected to the same box.
1031 Provide "udevtrigger" program to request events on coldplug. The
1032 shell script is much too slow with thousends of devices.
1036 Fix persistent disk rules to exclude removable IDE drives.
1038 Warn if %e, $modalias or MODALIAS is used.
1042 Fix queue export, which wasn't correct for subsequent add/remove
1043 events for the same device.
1047 Fix cramfs detection on big endian.
1049 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1054 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1055 attributes were only checked at the parent device that matched the
1056 by BUS requested subsystem. Fix it to also look at the device we
1057 received the event for.
1059 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1064 Fix a bug where NAME="" would prevent RUN from beeing executed.
1066 RUN="/bin/program" does not longer automatically add the subsystem
1067 as the first parameter. This is from the days of /sbin/hotplug
1068 which is dead now and it's just confusing to need to add a space at
1069 the end of the program name to prevent this.
1070 If you use rules that need the subsystem as the first parameter,
1071 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1072 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1076 The udev man page has moved to udev(7) as it does not describe a command
1077 anymore. The programs udev, udevstart and udevsend are no longer installed
1078 by default and must be copied manually, if they should be installed or
1079 included in a package.
1081 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1082 the ignore rule was applied.
1084 More preparation for future sysfs changes. usb_id and scsi_id no longer
1085 depend on a magic order of devices in the /devices chain. Specific devices
1086 should be requested by their subsytem.
1088 This will always find the scsi parent device without depending on a specific
1090 dev = sysfs_device_get(devpath);
1091 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1093 The "device" link in the current sysfs layout will be automatically
1094 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1095 parent in the devpath. If a device is requested by it's symlink, like all
1096 class devices in the new sysfs layout will look like, it gets automatically
1097 resolved and substituted with the real devpath and not the symlink path.
1100 A similar logic must be applied to _all_ sysfs users, including
1101 scripts, that search along parent devices in sysfs. The explicit use of
1102 the "device" link must be avoided. With the future sysfs layout all
1103 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1104 back to the "class" or the "bus". The layout of the parent devices in
1105 /devices is not necessarily expected to be stable across kernel releases and
1106 searching for parents by their subsystem should make sysfs users tolerant
1107 for changed parent chains.
1111 Prepare udev to work with the experimental kernel patch, that moves
1112 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1114 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1115 moving the class devices to /sys/devices.
1117 Thanks again to Marco for help finding a hopefully nice compromise
1118 to make %b simpler and working again.
1122 Complete removal of libsysfs, replaced by simple helper functions
1123 which are much simpler and a bit faster. The udev daemon operatesentirely
1124 on event parameters and does not use sysfs for simple rules anymore.
1125 Please report any new bugs/problems, that may be caused by this big
1126 change. They will be fixed immediately.
1128 The enumeration format character '%e' is deprecated and will be
1129 removed sometimes from a future udev version. It never worked correctly
1130 outside of udevstart, so we can't use it with the new parallel
1131 coldplug. A simple enumeration is as useless as the devfs naming
1132 scheme, just get rid of both if you still use it.
1134 MODALIAS and $modalias is not needed and will be removed from one of
1135 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1136 the sysfs "modalias" value.
1138 Thanks a lot to Marco for all his help on finding and fixing bugs.
1142 Let scsi_id request libata drive serial numbers from page 0x80.
1144 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1145 added /dev/disk/by-name/* for device mapper device names.
1147 Removed %e from the man page. It never worked reliably outside
1148 of udevstart and udevstart is no longer recommended to use.
1152 Symlinks are now exported to the event environment. Hopefully it's no
1153 longer needed to run udevinfo from an event process, like it was
1154 mentioned on the hotplug list:
1155 UDEV [1134776873.702967] add@/block/sdb
1158 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1162 Fix a problem if udevsend is used as the hotplug handler and tries to use
1163 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1164 and this kind of problems will hopefully go away soon.
1168 All built-in logic to work around bad sysfs timing is removed with this
1169 version. The need to wait for sysfs files is almost fixed with a kernel
1170 version that doesn't work with this udev version anyway. Until we fix
1171 the timing of the "bus" link creation, the former integrated logic should
1172 be emulated by a rule placed before all other rules:
1173 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1175 The option "udev_db" does no longer exist. All udev state will be in
1176 /$udev_root/.udev/ now, there is no longer an option to set this
1178 If the init script or something else used this value, just depend on
1179 this hardcoded path. But remember _all_content_ of this directory is
1180 still private to udev and can change at any time.
1182 Default location for rule sripts and helper programs is now: /lib/udev/.
1183 Everything that is not useful on the commandline should go into this
1184 directory. Some of the helpers in the extras folder are installed there
1185 now. The rules need to be changed, to find the helpers there.
1187 Also /lib/udev/devices is recommended as a directory where packages or
1188 the user can place real device nodes, which get copied over to /dev at
1189 every boot. This should replace the various solutions with custom config
1192 Udevsend does no longer start the udev daemon. This must be done with
1193 the init script that prepares /dev on tmpfs and creates the initial nodes,
1194 before starting the daemon.
1198 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1201 The copy of klibc is removed. A systemwide installed version of klibc
1202 should be used to build a klibc udev now.
1206 NAME="" will not create any nodes, but execute RUN keys. To completely
1207 ignore an event the OPTION "ignore_device" should be used.
1209 After removal of the reorder queue, events with a TIMEOUT can be executed
1210 without any queuing now.
1214 Fixed bug in udevd, if inotify is not available. We depend on netlink
1215 uevents now, kernels without that event source will not work with that
1216 version of udev anymore.
1220 The rule parsing happens now in the daemon once at startup, all udev
1221 event processes inherit the already parsed rules from the daemon.
1222 It is shipped with SUSE10.0 and reduces heavily the system load at
1223 startup. The option to save precompiled rules and let the udev process
1224 pick the them up is removed, as it's no longer needed.
1226 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1227 device. Libsysfs is changed to "translate" the requested link into the
1228 real device path, as it would happen with the hotplug event. Otherwise
1229 device removal and the udev database will not work.
1231 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1234 A few improvements for vol_id, the filesytem probing code.
1238 Fix a stupid typo in extras/run_directory for "make install".
1240 scsi_id creates the temporary devnode now in /dev for usage with a
1241 non-writable /tmp directory.
1243 The uevent kernel socket buffer can carry app. 50.000 events now,
1244 let's see who can break this again. :)
1246 The upcoming kernel will have a new input driver core integration.
1247 Some class devices are now symlinks to the real device. libsysfs
1248 needs a fix for this to work correctly. Udevstart of older udev
1249 versions will _not_ create these devices!
1253 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1258 A bunch of mostly trivial bugfixes. From now on no node name or
1259 symlink name can contain any character than plain whitelisted ascii
1260 characters or validated utf8 byte-streams. This is needed for the
1261 /dev/disk/by-label/* links, because we import untrusted data and
1262 export it to the filesystem.
1266 More bugfixes. If udevd was started from the kernel, we don't
1267 have stdin/stdout/stderr, which broke the forked tools in some
1272 Bugfix. udevstart event ordering was broken for a long time.
1273 The new run_program() uncovered it, because /dev/null was not
1274 available while we try to run external programs.
1275 Now udevstart should create it before we run anything.
1279 Minor bugfixes and some distro rules updates. If you don't have the
1280 persistent disk rules in /dev/disk/by-*/* on your distro, just
1281 grab it from here. :)
1285 We can use socket communication now to pass events from udev to
1287 RUN+="socket:/org/freedesktop/hal/udev_event"
1288 will pass the whole udev event to the HAL daemon without the need
1289 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1293 Mostly bugfixes and see ChangeLog.
1295 The test for the existence of an environment value should be
1297 ENV{KEY}=="*" to ENV{KEY}=="?*"
1298 because "*" will not fail anymore, if the key does not exist or
1303 Bugfixes and a few tweaks described in the ChangeLog.
1307 Mostly a Bugfix release.
1309 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1310 timing with custom rules.
1314 We changed the internal rule storage format. Our large rule files took
1315 2 MB of RAM, with the change we are down to 99kB.
1317 If the device-node has been created with default name and no symlink or
1318 options are to remenber, it is not longer stored in the udevdb. HAL will
1319 need to be updated to work correctly with that change.
1321 To overrride optimization flags, OPTFLAGS may be used now.
1329 Major changes happened with this release. The goal is to take over the
1330 complete kernel-event handling and provide a more efficient way to dispatch
1331 kernel events. Replacing most of the current shell script logic and the
1332 kernel forked helper with a netlink-daemon and a rule-based event handling.
1334 o udevd listens to netlink events now. The first valid netlink event
1335 will make udevd ignore any message from udevsend that contains a
1336 SEQNUM, to avoid duplicate events. The forked events can be disabled
1338 echo "" > /proc/sys/kernel/hotplug
1339 For full support, the broken input-subsytem needs to be fixed, not to
1340 bypass the driver core.
1342 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1343 removed from udev itself and must be emulated by calling small
1344 helper binaries provided in the extras folder:
1345 make EXTRAS=extras/run_directory/
1346 will build udev_run_devd and udev_run_hotplugd, which can be called
1347 from a rule if needed:
1348 RUN+="/sbin/udev_run_hotplugd"
1349 The recommended way to handle this is to convert all the calls from
1350 the directories to explicit udev rules and get completely rid of the
1351 multiplexing. (To catch a ttyUSB event, you now no longer need to
1352 fork and exit 300 tty script instances you are not interested in, it
1353 is just one rule that matches exactly the device.)
1355 o udev handles now _all_ events not just events for class and block
1356 devices, this way it is possible to control the complete event
1357 behavior with udev rules. Especially useful for rules like:
1358 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1360 o As used in the modalias rule, udev supports now textual
1361 substitution placeholder along with the usual format chars. This
1362 needs to be documented, for now it's only visible in udev_rules_parse.c.
1364 o The rule keys support now more operations. This is documented in the
1365 man page. It is possible to add values to list-keys like the SYMLINK
1366 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1367 Also "final"-assignments are supported by using KEY:="value", which will
1368 prevent changing the key by any later rule.
1370 o kernel 2.6.12 has the "detached_state" attribute removed from
1371 sysfs, which was used to recognize sysfs population. We switched that
1372 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1373 Running this udev version on older kernels may cause a short delay for
1376 o To provide infrastructure for persistent device naming, the id programs:
1377 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1378 to export the probed data in environment key format:
1379 pim:~ # /sbin/ata_id --export /dev/hda
1380 ID_MODEL=HTS726060M9AT00
1381 ID_SERIAL=MRH401M4G6UM9B
1382 ID_REVISION=MH4OA6BA
1384 The following rules:
1385 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1386 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1389 kay@pim:~> tree /dev/disk
1392 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1393 | `-- IBM-Memory_Key -> ../../sda
1395 | |-- swap -> ../../hda1
1396 | |-- date -> ../../sda1
1397 | `-- home -> ../../hda3
1399 |-- 2E08712B0870F2E7 -> ../../hda3
1400 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1401 |-- E845-7A89 -> ../../sda1
1402 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1404 The IMPORT= operation will import these keys in the environment and make
1405 it available for later PROGRAM= and RUN= executed programs. The keys are
1406 also stored in the udevdb and can be queried from there with one of the
1409 o A few binaries are silently added to the repository, which can be used
1410 to replay kernel events from initramfs instead of using coldplug. udevd
1411 can be instructed now to queue-up events while the stored events from
1412 initramfs are filled into the udevd-queue. This code is still under
1413 development and there is no documentation now besides the code itself.
1414 The additional binaries get compiled, but are not installed by default.
1416 o There is also a temporary fix for a performance problem where too many
1417 events happen in parallel and every event needs to parse the rules.
1418 udev can now read precompiled rules stored on disk. This is likely to be
1419 replaced by a more elegant solution in a future udev version.
1423 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1424 Fix for libsysfs not to expect this file was added.
1428 All rules are applied now, but only the first matching rule with a NAME-key
1429 will be applied. All later rules with NAME-key are completely ignored. This
1430 way system supplied symlinks or permissions gets applied to user-defined
1434 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1435 to some rules, to keep the old behavior.
1437 The rules are read on "remove"-events too. That makes is possible to match
1438 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1439 instruct udev to ignore an event (OPTIONS="ignore_device").
1440 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1442 The new RUN-key supports rule-based execution of programs after device-node
1443 handling. This is meant as a general replacement for the dev.d/-directories
1444 to give fine grained control over the execution of programs.
1446 The %s{}-sysfs format char replacement values are searched at any of the
1447 devices in the device chain now, not only at the class-device.
1449 We support log priority levels now. The value udev_log in udev.conf is used
1450 to determine what is printed to syslog. This makes it possible to
1451 run a version with compiled-in debug messages in a production environment
1452 which is sometimes needed to find a bug.
1453 It is still possible to supress the inclusion of _any_ syslog usage with
1454 USE_LOG=false to create the smallest possible binaries if needed.
1455 The configured udev_log value can be overridden with the environment variable
1460 Possible use of a system-wide klibc:
1461 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1462 will link against an external klibc and our own version will be ignored.
1466 We support an unlimited count of symlinks now.
1468 If USE_STATIC=true is passed to a glibc build, we link statically and use
1469 a built-in userdb parser to resolve user and group names.
1471 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1472 we walk up the chain of physical devices to find a match.
1474 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1475 easy to skip certain attribute matches without composing rules with weird
1476 character class negations like:
1477 KERNEL="[!s][!c][!d]*"
1478 this can now be replaced with:
1480 The current simple '=' is still supported, and should work as it does today,
1481 but existing rules should be converted if possible, to be better readable.
1483 We have new ENV{}== key now, to match against a maximum of 5 environment
1486 udevstart is its own binary again, because we don't need co carry this araound
1487 with every forked event.