8 Udev now gradually starts to pass control over the primary device nodes
9 and their names to the kernel, and will in the end only manage the
10 permissions of the node, and possibly create additional symlinks.
11 As a first step NAME="" will be ignored, and NAME= setings with names
12 other than the kernel provided name will result in a logged warning.
13 Kernels that don't provide device names, or devtmpfs is not used, will
14 still work as they did before, but it is strongly recommended to use
15 only the same names for the primary device node as the recent kernel
16 provides for all devices.
20 Fix broken firmware loader search path.
26 "udevadm trigger" defaults to "change" events now instead of "add"
27 events. The "udev boot script" might need to add "--action=add" to
28 the trigger command if not already there, in case the initial coldplug
29 events are expected as "add" events.
31 The option "all_partitons" was removed from udev. This should not be
32 needed for usual hardware. Udev can not safely make assumptions
33 about non-existing partition major/minor numbers, and therefore no
34 longer provide this unreliable and unsafe option.
36 The option "ignore_remove" was removed from udev. With devtmpfs
37 udev passed control over device nodes to the kernel. This option
38 should not be needed, or can not work as advertised. Neither
39 udev nor the kernel will remove device nodes which are copied from
40 the /lib/udev/devices/ directory.
42 All "add|change" matches are replaced by "!remove" in the rules and
43 in the udev logic. All types of events will update possible symlinks
44 and permissions, only "remove" is handled special now.
46 The modem modeswitch extra was removed and the external usb_modeswitch
47 program should be used instead.
49 New and fixed keymaps.
59 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
60 depend on the current sysfs layout and the information not available in the
61 deprecated layout. All remaining support for the deprecated sysfs layout is
66 Fix for a possible endless loop in the new input_id program.
72 The option "ignore_device" does no longer exist. There is no way to
73 ignore an event, as libudev events can not be suppressed by rules.
74 It only prevented RUN keys from being executed, which results in an
75 inconsistent behavior in current setups.
77 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
78 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
81 The support for the deprecated IDE devices has been removed from the
82 default set of rules. Distros who still care about non-libata drivers
83 need to add the rules to the compat rules file.
85 The ID_CLASS property on input devices has been replaced by the more accurate
86 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
87 determined by the new "input_id" prober now. Some devices, such as touchpads,
88 can have several classes. So if you previously had custom udev rules which e. g.
89 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
90 ENV{ID_INPUT_KEYBOARD}=="?*".
96 To support DEVPATH strings larger than the maximum file name length, the
97 private udev database format has changed. If some software still reads the
98 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
99 Please do not port anything to the new format again, everything in /dev/.udev
100 is and always was private to udev, and may and will change any time without
103 Multiple devices claiming the same names in /dev are limited to symlinks
104 only now. Mixing identical symlink names and node names is not supported.
105 This reduces the amount of data in the database significantly.
107 NAME="%k" causes a warning now. It's is and always was completely superfluous.
108 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
111 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
112 if they are not the default. To support older kernels, the NAME= rules need to
113 be added to the compat rules file.
115 Symlinks to udevadm with the old command names are no longer resolved to
116 the udevadm commands.
118 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
121 The option "last_rule" does no longer exist. Its use breaks too many
122 things which expect to be run from independent later rules, and is an idication
123 that something needs to be fixed properly instead.
125 The gudev API is no longer marked as experimental,
126 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
127 is enabled by default now. Various projects already depend on introspection
128 information to bind dynamic languages to the gudev interfaces.
134 The udevadm trigger "--retry-failed" option, which is replaced since quite
135 a while by "--type=failed" is removed.
137 The failed tracking was not working at all for a few releases. The RUN
138 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
139 default is not to track any failing RUN executions.
141 New keymaps, new modem, hid2hci updated.
145 Fix possible crash in udevd when worker processes are busy, rules are
146 changed at the same time, and workers get killed to reload the rules.
152 Properties set with ENV{.FOO}="bar" are marked private by starting the
153 name with a '.'. They will not be stored in the database, and not be
154 exported with the event.
156 Firmware files are looked up in:
157 /lib/firmware/updates/$(uname -r)
158 /lib/firmware/updates
159 /lib/firmware/$(uname -r)
163 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
164 ata_id, instead of scsi_id, is the default tool now for ATA devices.
170 The configure options have changed because another library needs to be
171 installed in a different location. Instead of exec_prefix and udev_prefix,
172 libdir, rootlibdir and libexecdir are used. The Details are explained in
175 Event processes now get re-used after they handled an event. This reduces
176 the number of forks and the pressure on the CPU significantly, because
177 cloned event processes no longer cause page faults in the main daemon.
178 After the events have settled, a few worker processes stay around for
179 future events, all others get cleaned up.
181 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
182 Also inotify support is mandatory now to run udev.
184 The format of the queue exported by the udev damon has changed. There is
185 no longer a /dev/.udev/queue/ directory. The current event queue can be
186 accessed with udevadm settle and libudedv.
188 Libudev does not have the unstable API header anymore. From now on,
189 incompatible changes will be handled by bumping the library major version.
191 To build udev from the git tree gtk-doc is needed now. The tarballs will
192 build without it and contain the pre-built documentation. An online copy
194 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
196 The tools from the udev-extras repository have been merged into the main
197 udev repository. Some of the extras have larger external dependencies, and
198 they can be disabled with the configure switch --disable-extras.
204 The program vol_id and the library libvolume_id are removed from the
205 repository. Libvolume_id is merged with libblkid from the util-linux-ng
206 package. Persistent disk links for label and uuid depend on the
207 util-linux-ng version (2.15) of blkid now. Older versions of blkid
208 can not be used with udev.
210 Libudev allows to subscribe to udev events. To prevent unwanted messages
211 to be delivered, and waking up the subscribing process, a filter can be
212 installed, to drop messages inside a kernel socket filter. The filters
213 match on the <subsytem>:<devtype> properties of the device.
214 This is part of the ongoing effort to replace HAL, and switch current
215 users over to directly use libudev.
216 Libudev is still marked as experimental, and its interface might
217 eventually change if needed, but no major changes of the currently exported
218 interface are expected anymore, and a first stable release should happen
221 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
222 is not supported since while and udevd will log an error message at
223 startup. It should still be able to boot-up, but advanced rules and system
224 services which depend on the information not available in the old sysfs
225 format will fail to work correctly.
227 DVB device naming is supplied by the kernel now. In case older kernels
228 need to be supported, the old shell script should be added to a compat
235 The processed udev events get send back to the netlink socket. Libudev
236 provides access to these events. This is work-in-progress, to replace
237 the DeviceKit daemon functionality directly with libudev. There are
238 upcoming kernel changes to allow non-root users to subcribe to these
245 "udevadm settle" now optionally accepts a range of events to wait for,
246 instead of waiting for "all" events.
252 The installed watch for block device metadata changes is now removed
253 during event hadling, because some (broken) tools may be called from udev
254 rules and (wrongly) open the device with write access. After the finished
255 event handling the watch is restored.
261 Device nodes can be watched for changes with inotify with OPTIONS="watch".
262 If closed after being opened for writing, a "change" uevent will occur.
263 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
269 The udevadm test command has no longer a --force option, nodes and symlinks
270 are always updated with a test run now.
272 The udevd daemon can be started with --resolve-names=never to avoid all user
273 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
274 lookup user and groups every time events are handled.
280 We are currently merging the Ubuntu rules in the udev default rules,
281 and get one step closer to provide a common Linux /dev setup, regarding
282 device names, symlinks, and default device permissions. On udev startup,
283 we now expect the following groups to be resolvable to their ids with
285 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
286 LDAP setups need to make sure, that these groups are always resolvable at
287 bootup, with only the rootfs mounted, and without network access available.
289 Some systems may need to add some new, currently not used groups, or need
290 to add some users to new groups, but the cost of this change is minimal,
291 compared to the pain the current, rather random, differences between the
292 various distributions cause for upstream projects and third-party vendors.
294 In general, "normal" users who log into a machine should never be a member
295 of any such group, but the device-access should be managed by dynamic ACLs,
296 which get added and removed for the specific users on login/logout and
297 session activity/inactivity. These groups are only provided for custom setups,
298 and mainly system services, to allow proper privilege separation.
299 A video-streaming daemon uid would be a member of "audio" and "video", to get
300 access to the sound and video devices, but no "normal" user should ever belong
301 to the "audio" group, because he could listen to the built-in microphone with
302 any ssh-session established from the other side of the world.
304 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
305 which do not depend on the kernel device name. As usual, unique
306 devices - only a single one per product connected, or a real
307 USB serial number in the device - are always found with the same
308 name in the by-id/ directory.
309 Completely identical devices may overwrite their names in by-id/
310 and can only be found reliably in the by-path/ directory. Devices
311 specified by by-path/ must not change their connection, like the
312 USB port number they are plugged in, to keep their name.
314 To support some advanced features, Linux 2.6.22 is the oldest supported
315 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
316 supported. Older kernels should still work, and devices nodes should be
317 reliably created, but some rules and libudev will not work correctly because
318 the old kernels do not provide the expected information or interfaces.
324 Fix for a possible segfault while swapping network interface names in udev
331 The group "video" is part of the default rules now.
335 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
336 block devices in some cases. No common distro uses this option anymore,
337 and we do not get enough testing for this and recent udev versions. If
338 this option is not needed to run some old distro with a new kernel,
339 it should be disabled in the kernel config.
341 Bugfix for the $links substitution variable, which may crash if no links
342 are created. This should not happen in usual setups because we always
343 create /dev/{block,char}/ links.
345 The strings of the parsed rules, which are kept in memory, no longer
346 contain duplicate entries, or duplicate tails of strings. This, and the
347 new rules parsing/matching code reduces the total in-memory size of
348 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
351 The export of DEVTYPE=disk/partition got removed from the default
352 rules. This value is available from the kernel. The pnp shell script
353 modprobe hack is removed from the default rules. ACPI devices have _proper_
354 modalias support and take care of the same functionality.
355 Installations which support old kernels, but install current default
356 udev rules may want to add that to the compat rules file.
358 Libvolume_id now always probes for all known filesystems, and does not
359 stop at the first match. Some filesystems are marked as "exclusive probe",
360 and if any other filesytem type matches at the same time, libvolume_id
361 will, by default, not return any probing result. This is intended to prevent
362 mis-detection with conflicting left-over signatures found from earlier
363 file system formats. That way, we no longer depend on the probe-order
364 in case of multiple competing signatures. In some setups the kernel allows
365 to mount a volume with just the old filesystem signature still in place.
366 This may damage the new filesystem and cause data-loss, just by mounting
367 it. Because volume_id can not decide which one the correct signature is,
368 the wrong signatures need to be removed manually from the volume, or the
369 volume needs to be reformatted, to enable filesystem detection and possible
374 Fix segfault if compiled without optimization and dbg() does not get
375 compiled out and uses variables which are not available.
379 Bugfixes. (And maybe new bugs. :))
381 The rule matching engine got converted from a rule list to a token
382 array which reduced the in-memory rules representation of a full
383 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
384 Limits like 5 ENV and ATTR matches, and one single instance for most
385 other keys per rule are gone.
387 The NAME assignment is no longer special cased. If later rules assign
388 a NAME value again, the former value will be overwritten. As usual
389 for most other keys, the NAME value can be protected by doing a final
390 assignment with NAME:="<value>".
392 All udev code now uses libudev, which is also exported. The library
393 is still under development, marked as experimental, and its interface
394 may change as long as the DeviceKit integration is not finished.
396 Many thanks to Alan Jenkins for his continuous help, and finding and
397 optimizing some of the computing expensive parts.
403 Kernel devices and device nodes are connected now by reverse indizes in
404 /sys and /dev. A device number retrieved by a stat() or similar, the
405 kernel device directory can be found by looking up:
406 /sys/dev/{block,char}/<maj>:<min>
407 and the device node of the same device by looking up:
408 /dev/{block,char}/<maj>:<min>
412 Fix recently introduced bug, which caused a compilation without large
413 file support, where vol_id does not recognize raid signatures at the end
416 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
417 Seems some kernel versions prevent the creation of the ieee-* links,
418 so people used the scsi-* link which disappeared now.
420 More libudev work. Almost all udevadm functionality comes from libudev
423 udevadm trigger has a new option --type, which allows to trigger events
424 for "devices", for "subsystems", or "failed" devices. The old option
425 --retry-failed" still works, but is no longer mentioned in the man page.
431 The udevadm info --device-id-of-file= output has changed to use
432 the obvious format. Possible current users should use the --export
433 option which is not affected.
435 The old udev commands symlinks to udevadm are not installed, if
436 these symlinks are used, a warning is printed.
442 Optical drive's media is no longer probed for raid signatures,
443 reading the end of the device causes some devices to malfunction.
444 Also the offset of the last session found is used now to probe
447 The volume_id library got a major version number update to 1,
448 some deprecated functions are removed.
450 A shared library "libudev" gets installed now to provide access
451 to udev device information. DeviceKit, the successor of HAL, will
452 need this library to access the udev database and search sysfs for
454 The library is currently in an experimental state, also the API is
455 expected to change, as long as the DeviceKit integration is not
460 We use ./configure now. See INSTALL for details. Current
463 "/usr" - prefix for man pages, include files
465 "" - the root filesystem, prefix for libs and binaries
469 "lib" - directory name for libraries, not a path name
470 multilib 64bit systems may use "lib64" instead of "lib"
472 compile-in verbose debug messages
474 disable all logging and compile-out all log strings
476 link against SELInux libraries, to set the expected context
479 In the default rules, the group "disk" gets permissions 0660 instead
480 of 0640. One small step closer to unify distro rules. Some day, all
481 distros hopefully end up with the same set of rules.
483 No symlinks to udevadm are installed anymore, if they are still needed,
484 they should be provided by the package.
490 Default udev rules, which are not supposed to be edited by the user, should
491 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
492 the udev package and will be replaced with an update. Udev will pick up rule
494 /lib/udev/rules.d/ - default installed rules
495 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
496 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
497 It does not matter in which directory a rule file lives, all files are sorted
500 To help creating /dev/root, we have now:
501 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
504 In case the current --device-id-of-file is already used, please switch to
505 the --export format version, it saves the output parsing and the old
506 format will be changed to use ':' as a separator, like the format in the
511 Fix cdrom_id to properly recognize blank media.
517 Tape drive id-data is queried from /dev/bsg/* instead of the tape
518 nodes. This avoids rewinding tapes on open().
524 The symlinks udevcontrol and udevtrigger are no longer installed by
527 The scsi_id program does not depend on sysfs anymore. It can speak
528 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
529 data, which should solve some old problems with tape devices, where
530 we better do not open all tape device nodes to identify the device.
536 The cdrom_id program is replaced by an advanced version, which can
537 detect most common device types, and also properties of the inserted
538 media. This is part of moving some basic functionality from HAL into
539 udev (and the kernel).
545 The last WAIT_FOR_SYSFS rule is removed from the default rules.
547 The symlinks to udevadm for the debugging tools: udevmonitor and
548 udevtest are no longer created.
550 The symlinks to the udevadm man page for the old tool names are
553 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
554 should be prefixed with '@' to indicate that the path is not a
565 Udevstart is removed from the tree, it did not get installed for
566 a long time now, and is long replaced by trigger and settle.
572 All udev tools are merged into a single binary called udevadm.
573 The old names of the tools are built-in commands in udevadm now.
574 Symlinks to udevadm, with the names of the old tools, provide
575 the same functionality as the standalone tools. There is also
576 only a single udevadm.8 man page left for all tools.
578 Tools like mkinitramfs should be checked, if they need to include
579 udevadm in the list of files.
589 The etc/udev/rules.d/ directory now contains a default set of basic
590 udev rules. This initial version is the result of a rules file merge
591 of Fedora and openSUSE. For these both distros only a few specific
592 rules are left in their own file, named after the distro. Rules which
593 are optionally installed, because they are only valid for a specific
594 architecture, or rules for subsystems which are not always used are
595 in etc/udev/packages/.
601 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
602 actions by dynamically created rules.
604 SYMLINK=="<value>" matches agains the entries in the list of
605 currently defined symlinks. The links are not created in the
606 filesystem at that point in time, but the values can be matched.
608 RUN{ignore_error}+="<program>" will ignore any exit code from the
609 program and not record as a failed event.
615 Final merge of patches/features from the Ubuntu package.
621 Control characters in filesystem label strings are no longer silenty
622 removed, but hex-encoded, to be able to uniquely identify the device
623 by its symlink in /dev/disk/by-label/.
624 If libvolume_id is used by mount(8), LABEL= will work as expected,
625 if slashes or other characters are used in the label string.
627 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
628 can be specified now. The TEST key accepts an optional mode mask
629 TEST{0100}=="<is executable file>".
631 Scsi_id now supports a mode without expecting scsi-specific sysfs
632 entries to allow the extraction of cciss-device persistent properties.
638 In the future, we may see uuid's which are just simple character
639 strings (see the DDF Raid Specification). For that reason vol_id now
640 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
641 the creation of symlinks, the *_SAFE values ensure, that no control
642 or whitespace characters are used in the filename.
644 Possible users of libvolume_id, please use the volume_id_get_* functions.
645 The public struct will go away in a future release of the library.
651 Removal of useless extras/eventrecorder.sh.
661 The directory multiplexer for dev.d/ and hotplug.d are finally removed
662 from the udev package.
668 Symlinks can have priorities now, the priority is assigned to the device
669 and specified with OPTIONS="link_priority=100". Devices with higher
670 priorities overwrite the symlinks of devices with lower priorities.
671 If the device that currently owns the link, goes away, the symlink
672 will be removed, and recreated, pointing to the next device with the
673 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
674 more reliable, if multiple devices contain the same metadata and overwrite
677 The dasd_id program is removed from the udev tree, and dasdinfo, with the
678 needed rules, are part of the s390-tools now.
680 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
681 we may get the scsi sysfs mess fixed some day, and this will only catch
682 the devices we are looking for.
684 USB serial numbers for storage devices have the target:lun now appended,
685 to make it possibble to distinguish broken multi-lun devices with all
686 the same SCSI identifiers.
688 Note: The extra "run_directory" which searches and executes stuff in
689 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
690 with the next release. Make sure, that you don't use it anymore, or
691 provides your own implementation of that inefficient stuff.
692 We are tired of reports about a "slow udev", because these directories
693 contain stuff, that runs with _every_ event, instead of using rules,
694 that run programs only for the matching events.
704 DRIVER== will match only for devices that actually have a real
705 driver. DRIVERS== must be used, if parent devices should be
706 included in the match.
708 Libvolume_id's "linux_raid" detection needed another fix.
716 Add additional check to volume_id detection of via_raid, cause
717 some company decided to put a matching pattern all over the empty
718 storage area of their music players.
722 Fix path_id for SAS devices.
726 The udev daemon can be started with --debug-trace now, which will
727 execute all events serialized to get a chance to catch a possible
728 action that crashes the box.
730 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
731 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
732 are excluded from the warning. Referencing parent attributes directly
733 may break when something in the kernel driver model changes. Udev will
734 just find the attribute by walking up the parent chain.
736 Udevtrigger now sorts the list of devices depending on the device
737 dependency, so a "usb" device is triggered after the parent "pci"
742 Revert persistent-storage ata-serial '_' '-' replacement.
748 Udevtrigger can now filter the list of devices to be triggered. Matches
749 for subsystems or sysfs attributes can be specified.
751 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
752 zero-sized files to avoid pointing to /sys and confuse broken tools which
753 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
756 The rules and scripts to create udev rules for persistent network
757 devices and optical drives are in the extras/rules_generator directory
758 now. If you use something similar, please consider replacing your own
759 version with this, to share the support effort. The rule_generator
760 installs its own rules into /etc/udev/rules.d.
762 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
763 the rule_generator depends on cdrom_id to be called in an earlier rule.
769 Renaming of some key names (the old names still work):
770 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
771 (The behavior of the key DRIVER will change soon in one of the next
772 releases, to match only the event device, please switch to DRIVERS
773 instead. If DRIVER is used, it will behave like DRIVERS, but an error
775 With the new key names, we have a more consistent and simpler scheme.
776 We can match the properties of the event device only, with: KERNEL,
777 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
778 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
779 longer mentioned in the man page and should be switched in the rule
782 ATTR{file}="value" can be used now, to write to a sysfs file of the
783 event device. Instead of:
784 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
786 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
788 All the PHYSDEV* keys are deprecated and will be removed from a
790 PHYDEVPATH - is the path of a parent device and should not be
792 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
793 matched with SUBSYSTEMS==
794 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
795 Newer kernels will have DRIVER in the environment,
796 for older kernels udev puts in. Class device will
797 no longer carry this property of a parent and
798 DRIVERS== can be used to match such a parent value.
799 Note that ENV{DRIVER} is only available for a few bus devices, where
800 the driver is already bound at device event time. On coldplug, the
801 events for a lot devices are already bound to a driver, and they will have
802 that value set. But on hotplug, at the time the kernel creates the device,
803 it can't know what driver may claim the device after that, therefore
804 in most cases it will be empty.
806 Failed events should now be re-triggered with:
807 udevtrigger --retry-failed.
808 Please switch to this command, so we keep the details of the /dev/.udev/failed/
809 files private to the udev tools. We may need to switch the current symlink
810 target, cause some obviously broken tools try to scan all files in /dev
811 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
812 million times. This takes ages on slow boxes.
814 The udevinfo attribute walk (-a) now works with giving a device node
815 name (-n) instead of a devpath (-p). The query now always works, also when
816 no database file was created by udev.
818 The built-in /etc/passwd /etc/group parser is removed, we always depend on
819 getpwnam() and getgrnam() now. One of the next releases will depend on
820 fnmatch() and may use getopt_long().
824 Bugfixes and small improvements.
828 Fix path_id for recent kernels.
834 Added support for swapping network interface names, by temporarily
835 renaming the device and wait for the target name to become free.
839 The built-in MODALIAS key and substitution is removed.
843 The binary firmware helper is replaced by the usual simple
844 shell script. Udevsend is removed from the tree.
852 Some more keys require the correct use of '==' and '=' depending
853 on the kind of operation beeing an assignment or a match. Rules
854 with invalid operations are skipped and logged to syslog. Please
855 test with udevtest if the parsing of your rules throws errors and
856 fix possibly broken rules.
860 Provide "udevsettle" to wait for all current udev events to finish.
861 It also watches the current kernel netlink queue by comparing the
862 even sequence number to make sure that there are no current pending
863 events that have not already arrived in the daemon.
867 Fix rule to skip persistent rules for removable IDE devices, which
868 also skipped optical IDE drives.
870 All *_id program are installed in /lib/udev/ by default now.
872 No binary is stripped anymore as this should be done in the
873 packaging process and not at build time.
875 libvolume_id is provided as a shared library now and vol_id is
876 linked against it. Also one of the next HAL versions will require
877 this library, and the HAL build process will also require the
878 header file to be installed. The copy of the same code in HAL will
879 be removed to have only a single copy left on the system.
883 Add persistent links for SCSI tapes. The rules file is renamed
884 to 60-persistent-storage.rules.
886 Create persistent path for usb devices. Can be used for all sorts
887 of devices that can't be distinguished by other properties like
888 multiple identical keyboards and mice connected to the same box.
890 Provide "udevtrigger" program to request events on coldplug. The
891 shell script is much too slow with thousends of devices.
895 Fix persistent disk rules to exclude removable IDE drives.
897 Warn if %e, $modalias or MODALIAS is used.
901 Fix queue export, which wasn't correct for subsequent add/remove
902 events for the same device.
906 Fix cramfs detection on big endian.
908 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
913 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
914 attributes were only checked at the parent device that matched the
915 by BUS requested subsystem. Fix it to also look at the device we
916 received the event for.
918 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
923 Fix a bug where NAME="" would prevent RUN from beeing executed.
925 RUN="/bin/program" does not longer automatically add the subsystem
926 as the first parameter. This is from the days of /sbin/hotplug
927 which is dead now and it's just confusing to need to add a space at
928 the end of the program name to prevent this.
929 If you use rules that need the subsystem as the first parameter,
930 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
931 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
935 The udev man page has moved to udev(7) as it does not describe a command
936 anymore. The programs udev, udevstart and udevsend are no longer installed
937 by default and must be copied manually, if they should be installed or
938 included in a package.
940 Fix a bug where "ignore_device" could run earlier collected RUN keys before
941 the ignore rule was applied.
943 More preparation for future sysfs changes. usb_id and scsi_id no longer
944 depend on a magic order of devices in the /devices chain. Specific devices
945 should be requested by their subsytem.
947 This will always find the scsi parent device without depending on a specific
949 dev = sysfs_device_get(devpath);
950 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
952 The "device" link in the current sysfs layout will be automatically
953 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
954 parent in the devpath. If a device is requested by it's symlink, like all
955 class devices in the new sysfs layout will look like, it gets automatically
956 resolved and substituted with the real devpath and not the symlink path.
959 A similar logic must be applied to _all_ sysfs users, including
960 scripts, that search along parent devices in sysfs. The explicit use of
961 the "device" link must be avoided. With the future sysfs layout all
962 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
963 back to the "class" or the "bus". The layout of the parent devices in
964 /devices is not necessarily expected to be stable across kernel releases and
965 searching for parents by their subsystem should make sysfs users tolerant
966 for changed parent chains.
970 Prepare udev to work with the experimental kernel patch, that moves
971 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
973 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
974 moving the class devices to /sys/devices.
976 Thanks again to Marco for help finding a hopefully nice compromise
977 to make %b simpler and working again.
981 Complete removal of libsysfs, replaced by simple helper functions
982 which are much simpler and a bit faster. The udev daemon operatesentirely
983 on event parameters and does not use sysfs for simple rules anymore.
984 Please report any new bugs/problems, that may be caused by this big
985 change. They will be fixed immediately.
987 The enumeration format character '%e' is deprecated and will be
988 removed sometimes from a future udev version. It never worked correctly
989 outside of udevstart, so we can't use it with the new parallel
990 coldplug. A simple enumeration is as useless as the devfs naming
991 scheme, just get rid of both if you still use it.
993 MODALIAS and $modalias is not needed and will be removed from one of
994 the next udev versions, replace it in all rules with ENV{MODALIAS} or
995 the sysfs "modalias" value.
997 Thanks a lot to Marco for all his help on finding and fixing bugs.
1001 Let scsi_id request libata drive serial numbers from page 0x80.
1003 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1004 added /dev/disk/by-name/* for device mapper device names.
1006 Removed %e from the man page. It never worked reliably outside
1007 of udevstart and udevstart is no longer recommended to use.
1011 Symlinks are now exported to the event environment. Hopefully it's no
1012 longer needed to run udevinfo from an event process, like it was
1013 mentioned on the hotplug list:
1014 UDEV [1134776873.702967] add@/block/sdb
1017 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1021 Fix a problem if udevsend is used as the hotplug handler and tries to use
1022 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1023 and this kind of problems will hopefully go away soon.
1027 All built-in logic to work around bad sysfs timing is removed with this
1028 version. The need to wait for sysfs files is almost fixed with a kernel
1029 version that doesn't work with this udev version anyway. Until we fix
1030 the timing of the "bus" link creation, the former integrated logic should
1031 be emulated by a rule placed before all other rules:
1032 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1034 The option "udev_db" does no longer exist. All udev state will be in
1035 /$udev_root/.udev/ now, there is no longer an option to set this
1037 If the init script or something else used this value, just depend on
1038 this hardcoded path. But remember _all_content_ of this directory is
1039 still private to udev and can change at any time.
1041 Default location for rule sripts and helper programs is now: /lib/udev/.
1042 Everything that is not useful on the commandline should go into this
1043 directory. Some of the helpers in the extras folder are installed there
1044 now. The rules need to be changed, to find the helpers there.
1046 Also /lib/udev/devices is recommended as a directory where packages or
1047 the user can place real device nodes, which get copied over to /dev at
1048 every boot. This should replace the various solutions with custom config
1051 Udevsend does no longer start the udev daemon. This must be done with
1052 the init script that prepares /dev on tmpfs and creates the initial nodes,
1053 before starting the daemon.
1057 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1060 The copy of klibc is removed. A systemwide installed version of klibc
1061 should be used to build a klibc udev now.
1065 NAME="" will not create any nodes, but execute RUN keys. To completely
1066 ignore an event the OPTION "ignore_device" should be used.
1068 After removal of the reorder queue, events with a TIMEOUT can be executed
1069 without any queuing now.
1073 Fixed bug in udevd, if inotify is not available. We depend on netlink
1074 uevents now, kernels without that event source will not work with that
1075 version of udev anymore.
1079 The rule parsing happens now in the daemon once at startup, all udev
1080 event processes inherit the already parsed rules from the daemon.
1081 It is shipped with SUSE10.0 and reduces heavily the system load at
1082 startup. The option to save precompiled rules and let the udev process
1083 pick the them up is removed, as it's no longer needed.
1085 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1086 device. Libsysfs is changed to "translate" the requested link into the
1087 real device path, as it would happen with the hotplug event. Otherwise
1088 device removal and the udev database will not work.
1090 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1093 A few improvements for vol_id, the filesytem probing code.
1097 Fix a stupid typo in extras/run_directory for "make install".
1099 scsi_id creates the temporary devnode now in /dev for usage with a
1100 non-writable /tmp directory.
1102 The uevent kernel socket buffer can carry app. 50.000 events now,
1103 let's see who can break this again. :)
1105 The upcoming kernel will have a new input driver core integration.
1106 Some class devices are now symlinks to the real device. libsysfs
1107 needs a fix for this to work correctly. Udevstart of older udev
1108 versions will _not_ create these devices!
1112 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1117 A bunch of mostly trivial bugfixes. From now on no node name or
1118 symlink name can contain any character than plain whitelisted ascii
1119 characters or validated utf8 byte-streams. This is needed for the
1120 /dev/disk/by-label/* links, because we import untrusted data and
1121 export it to the filesystem.
1125 More bugfixes. If udevd was started from the kernel, we don't
1126 have stdin/stdout/stderr, which broke the forked tools in some
1131 Bugfix. udevstart event ordering was broken for a long time.
1132 The new run_program() uncovered it, because /dev/null was not
1133 available while we try to run external programs.
1134 Now udevstart should create it before we run anything.
1138 Minor bugfixes and some distro rules updates. If you don't have the
1139 persistent disk rules in /dev/disk/by-*/* on your distro, just
1140 grab it from here. :)
1144 We can use socket communication now to pass events from udev to
1146 RUN+="socket:/org/freedesktop/hal/udev_event"
1147 will pass the whole udev event to the HAL daemon without the need
1148 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1152 Mostly bugfixes and see ChangeLog.
1154 The test for the existence of an environment value should be
1156 ENV{KEY}=="*" to ENV{KEY}=="?*"
1157 because "*" will not fail anymore, if the key does not exist or
1162 Bugfixes and a few tweaks described in the ChangeLog.
1166 Mostly a Bugfix release.
1168 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1169 timing with custom rules.
1173 We changed the internal rule storage format. Our large rule files took
1174 2 MB of RAM, with the change we are down to 99kB.
1176 If the device-node has been created with default name and no symlink or
1177 options are to remenber, it is not longer stored in the udevdb. HAL will
1178 need to be updated to work correctly with that change.
1180 To overrride optimization flags, OPTFLAGS may be used now.
1188 Major changes happened with this release. The goal is to take over the
1189 complete kernel-event handling and provide a more efficient way to dispatch
1190 kernel events. Replacing most of the current shell script logic and the
1191 kernel forked helper with a netlink-daemon and a rule-based event handling.
1193 o udevd listens to netlink events now. The first valid netlink event
1194 will make udevd ignore any message from udevsend that contains a
1195 SEQNUM, to avoid duplicate events. The forked events can be disabled
1197 echo "" > /proc/sys/kernel/hotplug
1198 For full support, the broken input-subsytem needs to be fixed, not to
1199 bypass the driver core.
1201 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1202 removed from udev itself and must be emulated by calling small
1203 helper binaries provided in the extras folder:
1204 make EXTRAS=extras/run_directory/
1205 will build udev_run_devd and udev_run_hotplugd, which can be called
1206 from a rule if needed:
1207 RUN+="/sbin/udev_run_hotplugd"
1208 The recommended way to handle this is to convert all the calls from
1209 the directories to explicit udev rules and get completely rid of the
1210 multiplexing. (To catch a ttyUSB event, you now no longer need to
1211 fork and exit 300 tty script instances you are not interested in, it
1212 is just one rule that matches exactly the device.)
1214 o udev handles now _all_ events not just events for class and block
1215 devices, this way it is possible to control the complete event
1216 behavior with udev rules. Especially useful for rules like:
1217 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1219 o As used in the modalias rule, udev supports now textual
1220 substitution placeholder along with the usual format chars. This
1221 needs to be documented, for now it's only visible in udev_rules_parse.c.
1223 o The rule keys support now more operations. This is documented in the
1224 man page. It is possible to add values to list-keys like the SYMLINK
1225 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1226 Also "final"-assignments are supported by using KEY:="value", which will
1227 prevent changing the key by any later rule.
1229 o kernel 2.6.12 has the "detached_state" attribute removed from
1230 sysfs, which was used to recognize sysfs population. We switched that
1231 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1232 Running this udev version on older kernels may cause a short delay for
1235 o To provide infrastructure for persistent device naming, the id programs:
1236 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1237 to export the probed data in environment key format:
1238 pim:~ # /sbin/ata_id --export /dev/hda
1239 ID_MODEL=HTS726060M9AT00
1240 ID_SERIAL=MRH401M4G6UM9B
1241 ID_REVISION=MH4OA6BA
1243 The following rules:
1244 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1245 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1248 kay@pim:~> tree /dev/disk
1251 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1252 | `-- IBM-Memory_Key -> ../../sda
1254 | |-- swap -> ../../hda1
1255 | |-- date -> ../../sda1
1256 | `-- home -> ../../hda3
1258 |-- 2E08712B0870F2E7 -> ../../hda3
1259 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1260 |-- E845-7A89 -> ../../sda1
1261 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1263 The IMPORT= operation will import these keys in the environment and make
1264 it available for later PROGRAM= and RUN= executed programs. The keys are
1265 also stored in the udevdb and can be queried from there with one of the
1268 o A few binaries are silently added to the repository, which can be used
1269 to replay kernel events from initramfs instead of using coldplug. udevd
1270 can be instructed now to queue-up events while the stored events from
1271 initramfs are filled into the udevd-queue. This code is still under
1272 development and there is no documentation now besides the code itself.
1273 The additional binaries get compiled, but are not installed by default.
1275 o There is also a temporary fix for a performance problem where too many
1276 events happen in parallel and every event needs to parse the rules.
1277 udev can now read precompiled rules stored on disk. This is likely to be
1278 replaced by a more elegant solution in a future udev version.
1282 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1283 Fix for libsysfs not to expect this file was added.
1287 All rules are applied now, but only the first matching rule with a NAME-key
1288 will be applied. All later rules with NAME-key are completely ignored. This
1289 way system supplied symlinks or permissions gets applied to user-defined
1293 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1294 to some rules, to keep the old behavior.
1296 The rules are read on "remove"-events too. That makes is possible to match
1297 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1298 instruct udev to ignore an event (OPTIONS="ignore_device").
1299 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1301 The new RUN-key supports rule-based execution of programs after device-node
1302 handling. This is meant as a general replacement for the dev.d/-directories
1303 to give fine grained control over the execution of programs.
1305 The %s{}-sysfs format char replacement values are searched at any of the
1306 devices in the device chain now, not only at the class-device.
1308 We support log priority levels now. The value udev_log in udev.conf is used
1309 to determine what is printed to syslog. This makes it possible to
1310 run a version with compiled-in debug messages in a production environment
1311 which is sometimes needed to find a bug.
1312 It is still possible to supress the inclusion of _any_ syslog usage with
1313 USE_LOG=false to create the smallest possible binaries if needed.
1314 The configured udev_log value can be overridden with the environment variable
1319 Possible use of a system-wide klibc:
1320 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1321 will link against an external klibc and our own version will be ignored.
1325 We support an unlimited count of symlinks now.
1327 If USE_STATIC=true is passed to a glibc build, we link statically and use
1328 a built-in userdb parser to resolve user and group names.
1330 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1331 we walk up the chain of physical devices to find a match.
1333 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1334 easy to skip certain attribute matches without composing rules with weird
1335 character class negations like:
1336 KERNEL="[!s][!c][!d]*"
1337 this can now be replaced with:
1339 The current simple '=' is still supported, and should work as it does today,
1340 but existing rules should be converted if possible, to be better readable.
1342 We have new ENV{}== key now, to match against a maximum of 5 environment
1345 udevstart is its own binary again, because we don't need co carry this araound
1346 with every forked event.