5 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
6 was removed from udevd.
8 Udevd now parses the kernel commandline for the following variables:
9 udev.log-priority=<syslog priority>
10 udev.children-max=<maximum number of workers>
11 udev.exec-delay=<seconds to delay the execution of RUN=>
12 to help debuging coldplug setups where the loading of a kernel
13 module crashes the system.
23 Now the udev daemon itself, does on startup:
24 - copy the content of /lib/udev/devices to /dev
25 - create the standard symlinks like /dev/std{in,out,err},
26 /dev/core, /dev/fd, ...
27 - use static node information provided by kernel modules
28 and creates these nodes to allow module on-demand loading
29 - possibly apply permissions to all ststic nodes from udev
30 rules which are annotated to match a static node
32 The default mode for a device node is 0600 now to match the kernel
33 created devtmpfs defaults. If GROUP= is specified and no MODE= is
34 given the default will be 0660.
40 Udev now gradually starts to pass control over the primary device nodes
41 and their names to the kernel, and will in the end only manage the
42 permissions of the node, and possibly create additional symlinks.
43 As a first step NAME="" will be ignored, and NAME= setings with names
44 other than the kernel provided name will result in a logged warning.
45 Kernels that don't provide device names, or devtmpfs is not used, will
46 still work as they did before, but it is strongly recommended to use
47 only the same names for the primary device node as the recent kernel
48 provides for all devices.
52 Fix broken firmware loader search path.
58 "udevadm trigger" defaults to "change" events now instead of "add"
59 events. The "udev boot script" might need to add "--action=add" to
60 the trigger command if not already there, in case the initial coldplug
61 events are expected as "add" events.
63 The option "all_partitons" was removed from udev. This should not be
64 needed for usual hardware. Udev can not safely make assumptions
65 about non-existing partition major/minor numbers, and therefore no
66 longer provide this unreliable and unsafe option.
68 The option "ignore_remove" was removed from udev. With devtmpfs
69 udev passed control over device nodes to the kernel. This option
70 should not be needed, or can not work as advertised. Neither
71 udev nor the kernel will remove device nodes which are copied from
72 the /lib/udev/devices/ directory.
74 All "add|change" matches are replaced by "!remove" in the rules and
75 in the udev logic. All types of events will update possible symlinks
76 and permissions, only "remove" is handled special now.
78 The modem modeswitch extra was removed and the external usb_modeswitch
79 program should be used instead.
81 New and fixed keymaps.
91 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
92 depend on the current sysfs layout and the information not available in the
93 deprecated layout. All remaining support for the deprecated sysfs layout is
98 Fix for a possible endless loop in the new input_id program.
104 The option "ignore_device" does no longer exist. There is no way to
105 ignore an event, as libudev events can not be suppressed by rules.
106 It only prevented RUN keys from being executed, which results in an
107 inconsistent behavior in current setups.
109 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
110 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
113 The support for the deprecated IDE devices has been removed from the
114 default set of rules. Distros who still care about non-libata drivers
115 need to add the rules to the compat rules file.
117 The ID_CLASS property on input devices has been replaced by the more accurate
118 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
119 determined by the new "input_id" prober now. Some devices, such as touchpads,
120 can have several classes. So if you previously had custom udev rules which e. g.
121 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
122 ENV{ID_INPUT_KEYBOARD}=="?*".
128 To support DEVPATH strings larger than the maximum file name length, the
129 private udev database format has changed. If some software still reads the
130 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
131 Please do not port anything to the new format again, everything in /dev/.udev
132 is and always was private to udev, and may and will change any time without
135 Multiple devices claiming the same names in /dev are limited to symlinks
136 only now. Mixing identical symlink names and node names is not supported.
137 This reduces the amount of data in the database significantly.
139 NAME="%k" causes a warning now. It's is and always was completely superfluous.
140 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
143 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
144 if they are not the default. To support older kernels, the NAME= rules need to
145 be added to the compat rules file.
147 Symlinks to udevadm with the old command names are no longer resolved to
148 the udevadm commands.
150 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
153 The option "last_rule" does no longer exist. Its use breaks too many
154 things which expect to be run from independent later rules, and is an idication
155 that something needs to be fixed properly instead.
157 The gudev API is no longer marked as experimental,
158 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
159 is enabled by default now. Various projects already depend on introspection
160 information to bind dynamic languages to the gudev interfaces.
166 The udevadm trigger "--retry-failed" option, which is replaced since quite
167 a while by "--type=failed" is removed.
169 The failed tracking was not working at all for a few releases. The RUN
170 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
171 default is not to track any failing RUN executions.
173 New keymaps, new modem, hid2hci updated.
177 Fix possible crash in udevd when worker processes are busy, rules are
178 changed at the same time, and workers get killed to reload the rules.
184 Properties set with ENV{.FOO}="bar" are marked private by starting the
185 name with a '.'. They will not be stored in the database, and not be
186 exported with the event.
188 Firmware files are looked up in:
189 /lib/firmware/updates/$(uname -r)
190 /lib/firmware/updates
191 /lib/firmware/$(uname -r)
195 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
196 ata_id, instead of scsi_id, is the default tool now for ATA devices.
202 The configure options have changed because another library needs to be
203 installed in a different location. Instead of exec_prefix and udev_prefix,
204 libdir, rootlibdir and libexecdir are used. The Details are explained in
207 Event processes now get re-used after they handled an event. This reduces
208 the number of forks and the pressure on the CPU significantly, because
209 cloned event processes no longer cause page faults in the main daemon.
210 After the events have settled, a few worker processes stay around for
211 future events, all others get cleaned up.
213 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
214 Also inotify support is mandatory now to run udev.
216 The format of the queue exported by the udev damon has changed. There is
217 no longer a /dev/.udev/queue/ directory. The current event queue can be
218 accessed with udevadm settle and libudedv.
220 Libudev does not have the unstable API header anymore. From now on,
221 incompatible changes will be handled by bumping the library major version.
223 To build udev from the git tree gtk-doc is needed now. The tarballs will
224 build without it and contain the pre-built documentation. An online copy
226 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
228 The tools from the udev-extras repository have been merged into the main
229 udev repository. Some of the extras have larger external dependencies, and
230 they can be disabled with the configure switch --disable-extras.
236 The program vol_id and the library libvolume_id are removed from the
237 repository. Libvolume_id is merged with libblkid from the util-linux-ng
238 package. Persistent disk links for label and uuid depend on the
239 util-linux-ng version (2.15) of blkid now. Older versions of blkid
240 can not be used with udev.
242 Libudev allows to subscribe to udev events. To prevent unwanted messages
243 to be delivered, and waking up the subscribing process, a filter can be
244 installed, to drop messages inside a kernel socket filter. The filters
245 match on the <subsytem>:<devtype> properties of the device.
246 This is part of the ongoing effort to replace HAL, and switch current
247 users over to directly use libudev.
248 Libudev is still marked as experimental, and its interface might
249 eventually change if needed, but no major changes of the currently exported
250 interface are expected anymore, and a first stable release should happen
253 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
254 is not supported since while and udevd will log an error message at
255 startup. It should still be able to boot-up, but advanced rules and system
256 services which depend on the information not available in the old sysfs
257 format will fail to work correctly.
259 DVB device naming is supplied by the kernel now. In case older kernels
260 need to be supported, the old shell script should be added to a compat
267 The processed udev events get send back to the netlink socket. Libudev
268 provides access to these events. This is work-in-progress, to replace
269 the DeviceKit daemon functionality directly with libudev. There are
270 upcoming kernel changes to allow non-root users to subcribe to these
277 "udevadm settle" now optionally accepts a range of events to wait for,
278 instead of waiting for "all" events.
284 The installed watch for block device metadata changes is now removed
285 during event hadling, because some (broken) tools may be called from udev
286 rules and (wrongly) open the device with write access. After the finished
287 event handling the watch is restored.
293 Device nodes can be watched for changes with inotify with OPTIONS="watch".
294 If closed after being opened for writing, a "change" uevent will occur.
295 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
301 The udevadm test command has no longer a --force option, nodes and symlinks
302 are always updated with a test run now.
304 The udevd daemon can be started with --resolve-names=never to avoid all user
305 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
306 lookup user and groups every time events are handled.
312 We are currently merging the Ubuntu rules in the udev default rules,
313 and get one step closer to provide a common Linux /dev setup, regarding
314 device names, symlinks, and default device permissions. On udev startup,
315 we now expect the following groups to be resolvable to their ids with
317 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
318 LDAP setups need to make sure, that these groups are always resolvable at
319 bootup, with only the rootfs mounted, and without network access available.
321 Some systems may need to add some new, currently not used groups, or need
322 to add some users to new groups, but the cost of this change is minimal,
323 compared to the pain the current, rather random, differences between the
324 various distributions cause for upstream projects and third-party vendors.
326 In general, "normal" users who log into a machine should never be a member
327 of any such group, but the device-access should be managed by dynamic ACLs,
328 which get added and removed for the specific users on login/logout and
329 session activity/inactivity. These groups are only provided for custom setups,
330 and mainly system services, to allow proper privilege separation.
331 A video-streaming daemon uid would be a member of "audio" and "video", to get
332 access to the sound and video devices, but no "normal" user should ever belong
333 to the "audio" group, because he could listen to the built-in microphone with
334 any ssh-session established from the other side of the world.
336 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
337 which do not depend on the kernel device name. As usual, unique
338 devices - only a single one per product connected, or a real
339 USB serial number in the device - are always found with the same
340 name in the by-id/ directory.
341 Completely identical devices may overwrite their names in by-id/
342 and can only be found reliably in the by-path/ directory. Devices
343 specified by by-path/ must not change their connection, like the
344 USB port number they are plugged in, to keep their name.
346 To support some advanced features, Linux 2.6.22 is the oldest supported
347 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
348 supported. Older kernels should still work, and devices nodes should be
349 reliably created, but some rules and libudev will not work correctly because
350 the old kernels do not provide the expected information or interfaces.
356 Fix for a possible segfault while swapping network interface names in udev
363 The group "video" is part of the default rules now.
367 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
368 block devices in some cases. No common distro uses this option anymore,
369 and we do not get enough testing for this and recent udev versions. If
370 this option is not needed to run some old distro with a new kernel,
371 it should be disabled in the kernel config.
373 Bugfix for the $links substitution variable, which may crash if no links
374 are created. This should not happen in usual setups because we always
375 create /dev/{block,char}/ links.
377 The strings of the parsed rules, which are kept in memory, no longer
378 contain duplicate entries, or duplicate tails of strings. This, and the
379 new rules parsing/matching code reduces the total in-memory size of
380 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
383 The export of DEVTYPE=disk/partition got removed from the default
384 rules. This value is available from the kernel. The pnp shell script
385 modprobe hack is removed from the default rules. ACPI devices have _proper_
386 modalias support and take care of the same functionality.
387 Installations which support old kernels, but install current default
388 udev rules may want to add that to the compat rules file.
390 Libvolume_id now always probes for all known filesystems, and does not
391 stop at the first match. Some filesystems are marked as "exclusive probe",
392 and if any other filesytem type matches at the same time, libvolume_id
393 will, by default, not return any probing result. This is intended to prevent
394 mis-detection with conflicting left-over signatures found from earlier
395 file system formats. That way, we no longer depend on the probe-order
396 in case of multiple competing signatures. In some setups the kernel allows
397 to mount a volume with just the old filesystem signature still in place.
398 This may damage the new filesystem and cause data-loss, just by mounting
399 it. Because volume_id can not decide which one the correct signature is,
400 the wrong signatures need to be removed manually from the volume, or the
401 volume needs to be reformatted, to enable filesystem detection and possible
406 Fix segfault if compiled without optimization and dbg() does not get
407 compiled out and uses variables which are not available.
411 Bugfixes. (And maybe new bugs. :))
413 The rule matching engine got converted from a rule list to a token
414 array which reduced the in-memory rules representation of a full
415 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
416 Limits like 5 ENV and ATTR matches, and one single instance for most
417 other keys per rule are gone.
419 The NAME assignment is no longer special cased. If later rules assign
420 a NAME value again, the former value will be overwritten. As usual
421 for most other keys, the NAME value can be protected by doing a final
422 assignment with NAME:="<value>".
424 All udev code now uses libudev, which is also exported. The library
425 is still under development, marked as experimental, and its interface
426 may change as long as the DeviceKit integration is not finished.
428 Many thanks to Alan Jenkins for his continuous help, and finding and
429 optimizing some of the computing expensive parts.
435 Kernel devices and device nodes are connected now by reverse indizes in
436 /sys and /dev. A device number retrieved by a stat() or similar, the
437 kernel device directory can be found by looking up:
438 /sys/dev/{block,char}/<maj>:<min>
439 and the device node of the same device by looking up:
440 /dev/{block,char}/<maj>:<min>
444 Fix recently introduced bug, which caused a compilation without large
445 file support, where vol_id does not recognize raid signatures at the end
448 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
449 Seems some kernel versions prevent the creation of the ieee-* links,
450 so people used the scsi-* link which disappeared now.
452 More libudev work. Almost all udevadm functionality comes from libudev
455 udevadm trigger has a new option --type, which allows to trigger events
456 for "devices", for "subsystems", or "failed" devices. The old option
457 --retry-failed" still works, but is no longer mentioned in the man page.
463 The udevadm info --device-id-of-file= output has changed to use
464 the obvious format. Possible current users should use the --export
465 option which is not affected.
467 The old udev commands symlinks to udevadm are not installed, if
468 these symlinks are used, a warning is printed.
474 Optical drive's media is no longer probed for raid signatures,
475 reading the end of the device causes some devices to malfunction.
476 Also the offset of the last session found is used now to probe
479 The volume_id library got a major version number update to 1,
480 some deprecated functions are removed.
482 A shared library "libudev" gets installed now to provide access
483 to udev device information. DeviceKit, the successor of HAL, will
484 need this library to access the udev database and search sysfs for
486 The library is currently in an experimental state, also the API is
487 expected to change, as long as the DeviceKit integration is not
492 We use ./configure now. See INSTALL for details. Current
495 "/usr" - prefix for man pages, include files
497 "" - the root filesystem, prefix for libs and binaries
501 "lib" - directory name for libraries, not a path name
502 multilib 64bit systems may use "lib64" instead of "lib"
504 compile-in verbose debug messages
506 disable all logging and compile-out all log strings
508 link against SELInux libraries, to set the expected context
511 In the default rules, the group "disk" gets permissions 0660 instead
512 of 0640. One small step closer to unify distro rules. Some day, all
513 distros hopefully end up with the same set of rules.
515 No symlinks to udevadm are installed anymore, if they are still needed,
516 they should be provided by the package.
522 Default udev rules, which are not supposed to be edited by the user, should
523 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
524 the udev package and will be replaced with an update. Udev will pick up rule
526 /lib/udev/rules.d/ - default installed rules
527 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
528 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
529 It does not matter in which directory a rule file lives, all files are sorted
532 To help creating /dev/root, we have now:
533 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
536 In case the current --device-id-of-file is already used, please switch to
537 the --export format version, it saves the output parsing and the old
538 format will be changed to use ':' as a separator, like the format in the
543 Fix cdrom_id to properly recognize blank media.
549 Tape drive id-data is queried from /dev/bsg/* instead of the tape
550 nodes. This avoids rewinding tapes on open().
556 The symlinks udevcontrol and udevtrigger are no longer installed by
559 The scsi_id program does not depend on sysfs anymore. It can speak
560 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
561 data, which should solve some old problems with tape devices, where
562 we better do not open all tape device nodes to identify the device.
568 The cdrom_id program is replaced by an advanced version, which can
569 detect most common device types, and also properties of the inserted
570 media. This is part of moving some basic functionality from HAL into
571 udev (and the kernel).
577 The last WAIT_FOR_SYSFS rule is removed from the default rules.
579 The symlinks to udevadm for the debugging tools: udevmonitor and
580 udevtest are no longer created.
582 The symlinks to the udevadm man page for the old tool names are
585 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
586 should be prefixed with '@' to indicate that the path is not a
597 Udevstart is removed from the tree, it did not get installed for
598 a long time now, and is long replaced by trigger and settle.
604 All udev tools are merged into a single binary called udevadm.
605 The old names of the tools are built-in commands in udevadm now.
606 Symlinks to udevadm, with the names of the old tools, provide
607 the same functionality as the standalone tools. There is also
608 only a single udevadm.8 man page left for all tools.
610 Tools like mkinitramfs should be checked, if they need to include
611 udevadm in the list of files.
621 The etc/udev/rules.d/ directory now contains a default set of basic
622 udev rules. This initial version is the result of a rules file merge
623 of Fedora and openSUSE. For these both distros only a few specific
624 rules are left in their own file, named after the distro. Rules which
625 are optionally installed, because they are only valid for a specific
626 architecture, or rules for subsystems which are not always used are
627 in etc/udev/packages/.
633 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
634 actions by dynamically created rules.
636 SYMLINK=="<value>" matches agains the entries in the list of
637 currently defined symlinks. The links are not created in the
638 filesystem at that point in time, but the values can be matched.
640 RUN{ignore_error}+="<program>" will ignore any exit code from the
641 program and not record as a failed event.
647 Final merge of patches/features from the Ubuntu package.
653 Control characters in filesystem label strings are no longer silenty
654 removed, but hex-encoded, to be able to uniquely identify the device
655 by its symlink in /dev/disk/by-label/.
656 If libvolume_id is used by mount(8), LABEL= will work as expected,
657 if slashes or other characters are used in the label string.
659 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
660 can be specified now. The TEST key accepts an optional mode mask
661 TEST{0100}=="<is executable file>".
663 Scsi_id now supports a mode without expecting scsi-specific sysfs
664 entries to allow the extraction of cciss-device persistent properties.
670 In the future, we may see uuid's which are just simple character
671 strings (see the DDF Raid Specification). For that reason vol_id now
672 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
673 the creation of symlinks, the *_SAFE values ensure, that no control
674 or whitespace characters are used in the filename.
676 Possible users of libvolume_id, please use the volume_id_get_* functions.
677 The public struct will go away in a future release of the library.
683 Removal of useless extras/eventrecorder.sh.
693 The directory multiplexer for dev.d/ and hotplug.d are finally removed
694 from the udev package.
700 Symlinks can have priorities now, the priority is assigned to the device
701 and specified with OPTIONS="link_priority=100". Devices with higher
702 priorities overwrite the symlinks of devices with lower priorities.
703 If the device that currently owns the link, goes away, the symlink
704 will be removed, and recreated, pointing to the next device with the
705 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
706 more reliable, if multiple devices contain the same metadata and overwrite
709 The dasd_id program is removed from the udev tree, and dasdinfo, with the
710 needed rules, are part of the s390-tools now.
712 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
713 we may get the scsi sysfs mess fixed some day, and this will only catch
714 the devices we are looking for.
716 USB serial numbers for storage devices have the target:lun now appended,
717 to make it possibble to distinguish broken multi-lun devices with all
718 the same SCSI identifiers.
720 Note: The extra "run_directory" which searches and executes stuff in
721 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
722 with the next release. Make sure, that you don't use it anymore, or
723 provides your own implementation of that inefficient stuff.
724 We are tired of reports about a "slow udev", because these directories
725 contain stuff, that runs with _every_ event, instead of using rules,
726 that run programs only for the matching events.
736 DRIVER== will match only for devices that actually have a real
737 driver. DRIVERS== must be used, if parent devices should be
738 included in the match.
740 Libvolume_id's "linux_raid" detection needed another fix.
748 Add additional check to volume_id detection of via_raid, cause
749 some company decided to put a matching pattern all over the empty
750 storage area of their music players.
754 Fix path_id for SAS devices.
758 The udev daemon can be started with --debug-trace now, which will
759 execute all events serialized to get a chance to catch a possible
760 action that crashes the box.
762 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
763 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
764 are excluded from the warning. Referencing parent attributes directly
765 may break when something in the kernel driver model changes. Udev will
766 just find the attribute by walking up the parent chain.
768 Udevtrigger now sorts the list of devices depending on the device
769 dependency, so a "usb" device is triggered after the parent "pci"
774 Revert persistent-storage ata-serial '_' '-' replacement.
780 Udevtrigger can now filter the list of devices to be triggered. Matches
781 for subsystems or sysfs attributes can be specified.
783 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
784 zero-sized files to avoid pointing to /sys and confuse broken tools which
785 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
788 The rules and scripts to create udev rules for persistent network
789 devices and optical drives are in the extras/rules_generator directory
790 now. If you use something similar, please consider replacing your own
791 version with this, to share the support effort. The rule_generator
792 installs its own rules into /etc/udev/rules.d.
794 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
795 the rule_generator depends on cdrom_id to be called in an earlier rule.
801 Renaming of some key names (the old names still work):
802 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
803 (The behavior of the key DRIVER will change soon in one of the next
804 releases, to match only the event device, please switch to DRIVERS
805 instead. If DRIVER is used, it will behave like DRIVERS, but an error
807 With the new key names, we have a more consistent and simpler scheme.
808 We can match the properties of the event device only, with: KERNEL,
809 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
810 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
811 longer mentioned in the man page and should be switched in the rule
814 ATTR{file}="value" can be used now, to write to a sysfs file of the
815 event device. Instead of:
816 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
818 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
820 All the PHYSDEV* keys are deprecated and will be removed from a
822 PHYDEVPATH - is the path of a parent device and should not be
824 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
825 matched with SUBSYSTEMS==
826 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
827 Newer kernels will have DRIVER in the environment,
828 for older kernels udev puts in. Class device will
829 no longer carry this property of a parent and
830 DRIVERS== can be used to match such a parent value.
831 Note that ENV{DRIVER} is only available for a few bus devices, where
832 the driver is already bound at device event time. On coldplug, the
833 events for a lot devices are already bound to a driver, and they will have
834 that value set. But on hotplug, at the time the kernel creates the device,
835 it can't know what driver may claim the device after that, therefore
836 in most cases it will be empty.
838 Failed events should now be re-triggered with:
839 udevtrigger --retry-failed.
840 Please switch to this command, so we keep the details of the /dev/.udev/failed/
841 files private to the udev tools. We may need to switch the current symlink
842 target, cause some obviously broken tools try to scan all files in /dev
843 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
844 million times. This takes ages on slow boxes.
846 The udevinfo attribute walk (-a) now works with giving a device node
847 name (-n) instead of a devpath (-p). The query now always works, also when
848 no database file was created by udev.
850 The built-in /etc/passwd /etc/group parser is removed, we always depend on
851 getpwnam() and getgrnam() now. One of the next releases will depend on
852 fnmatch() and may use getopt_long().
856 Bugfixes and small improvements.
860 Fix path_id for recent kernels.
866 Added support for swapping network interface names, by temporarily
867 renaming the device and wait for the target name to become free.
871 The built-in MODALIAS key and substitution is removed.
875 The binary firmware helper is replaced by the usual simple
876 shell script. Udevsend is removed from the tree.
884 Some more keys require the correct use of '==' and '=' depending
885 on the kind of operation beeing an assignment or a match. Rules
886 with invalid operations are skipped and logged to syslog. Please
887 test with udevtest if the parsing of your rules throws errors and
888 fix possibly broken rules.
892 Provide "udevsettle" to wait for all current udev events to finish.
893 It also watches the current kernel netlink queue by comparing the
894 even sequence number to make sure that there are no current pending
895 events that have not already arrived in the daemon.
899 Fix rule to skip persistent rules for removable IDE devices, which
900 also skipped optical IDE drives.
902 All *_id program are installed in /lib/udev/ by default now.
904 No binary is stripped anymore as this should be done in the
905 packaging process and not at build time.
907 libvolume_id is provided as a shared library now and vol_id is
908 linked against it. Also one of the next HAL versions will require
909 this library, and the HAL build process will also require the
910 header file to be installed. The copy of the same code in HAL will
911 be removed to have only a single copy left on the system.
915 Add persistent links for SCSI tapes. The rules file is renamed
916 to 60-persistent-storage.rules.
918 Create persistent path for usb devices. Can be used for all sorts
919 of devices that can't be distinguished by other properties like
920 multiple identical keyboards and mice connected to the same box.
922 Provide "udevtrigger" program to request events on coldplug. The
923 shell script is much too slow with thousends of devices.
927 Fix persistent disk rules to exclude removable IDE drives.
929 Warn if %e, $modalias or MODALIAS is used.
933 Fix queue export, which wasn't correct for subsequent add/remove
934 events for the same device.
938 Fix cramfs detection on big endian.
940 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
945 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
946 attributes were only checked at the parent device that matched the
947 by BUS requested subsystem. Fix it to also look at the device we
948 received the event for.
950 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
955 Fix a bug where NAME="" would prevent RUN from beeing executed.
957 RUN="/bin/program" does not longer automatically add the subsystem
958 as the first parameter. This is from the days of /sbin/hotplug
959 which is dead now and it's just confusing to need to add a space at
960 the end of the program name to prevent this.
961 If you use rules that need the subsystem as the first parameter,
962 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
963 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
967 The udev man page has moved to udev(7) as it does not describe a command
968 anymore. The programs udev, udevstart and udevsend are no longer installed
969 by default and must be copied manually, if they should be installed or
970 included in a package.
972 Fix a bug where "ignore_device" could run earlier collected RUN keys before
973 the ignore rule was applied.
975 More preparation for future sysfs changes. usb_id and scsi_id no longer
976 depend on a magic order of devices in the /devices chain. Specific devices
977 should be requested by their subsytem.
979 This will always find the scsi parent device without depending on a specific
981 dev = sysfs_device_get(devpath);
982 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
984 The "device" link in the current sysfs layout will be automatically
985 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
986 parent in the devpath. If a device is requested by it's symlink, like all
987 class devices in the new sysfs layout will look like, it gets automatically
988 resolved and substituted with the real devpath and not the symlink path.
991 A similar logic must be applied to _all_ sysfs users, including
992 scripts, that search along parent devices in sysfs. The explicit use of
993 the "device" link must be avoided. With the future sysfs layout all
994 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
995 back to the "class" or the "bus". The layout of the parent devices in
996 /devices is not necessarily expected to be stable across kernel releases and
997 searching for parents by their subsystem should make sysfs users tolerant
998 for changed parent chains.
1002 Prepare udev to work with the experimental kernel patch, that moves
1003 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1005 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1006 moving the class devices to /sys/devices.
1008 Thanks again to Marco for help finding a hopefully nice compromise
1009 to make %b simpler and working again.
1013 Complete removal of libsysfs, replaced by simple helper functions
1014 which are much simpler and a bit faster. The udev daemon operatesentirely
1015 on event parameters and does not use sysfs for simple rules anymore.
1016 Please report any new bugs/problems, that may be caused by this big
1017 change. They will be fixed immediately.
1019 The enumeration format character '%e' is deprecated and will be
1020 removed sometimes from a future udev version. It never worked correctly
1021 outside of udevstart, so we can't use it with the new parallel
1022 coldplug. A simple enumeration is as useless as the devfs naming
1023 scheme, just get rid of both if you still use it.
1025 MODALIAS and $modalias is not needed and will be removed from one of
1026 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1027 the sysfs "modalias" value.
1029 Thanks a lot to Marco for all his help on finding and fixing bugs.
1033 Let scsi_id request libata drive serial numbers from page 0x80.
1035 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1036 added /dev/disk/by-name/* for device mapper device names.
1038 Removed %e from the man page. It never worked reliably outside
1039 of udevstart and udevstart is no longer recommended to use.
1043 Symlinks are now exported to the event environment. Hopefully it's no
1044 longer needed to run udevinfo from an event process, like it was
1045 mentioned on the hotplug list:
1046 UDEV [1134776873.702967] add@/block/sdb
1049 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1053 Fix a problem if udevsend is used as the hotplug handler and tries to use
1054 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1055 and this kind of problems will hopefully go away soon.
1059 All built-in logic to work around bad sysfs timing is removed with this
1060 version. The need to wait for sysfs files is almost fixed with a kernel
1061 version that doesn't work with this udev version anyway. Until we fix
1062 the timing of the "bus" link creation, the former integrated logic should
1063 be emulated by a rule placed before all other rules:
1064 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1066 The option "udev_db" does no longer exist. All udev state will be in
1067 /$udev_root/.udev/ now, there is no longer an option to set this
1069 If the init script or something else used this value, just depend on
1070 this hardcoded path. But remember _all_content_ of this directory is
1071 still private to udev and can change at any time.
1073 Default location for rule sripts and helper programs is now: /lib/udev/.
1074 Everything that is not useful on the commandline should go into this
1075 directory. Some of the helpers in the extras folder are installed there
1076 now. The rules need to be changed, to find the helpers there.
1078 Also /lib/udev/devices is recommended as a directory where packages or
1079 the user can place real device nodes, which get copied over to /dev at
1080 every boot. This should replace the various solutions with custom config
1083 Udevsend does no longer start the udev daemon. This must be done with
1084 the init script that prepares /dev on tmpfs and creates the initial nodes,
1085 before starting the daemon.
1089 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1092 The copy of klibc is removed. A systemwide installed version of klibc
1093 should be used to build a klibc udev now.
1097 NAME="" will not create any nodes, but execute RUN keys. To completely
1098 ignore an event the OPTION "ignore_device" should be used.
1100 After removal of the reorder queue, events with a TIMEOUT can be executed
1101 without any queuing now.
1105 Fixed bug in udevd, if inotify is not available. We depend on netlink
1106 uevents now, kernels without that event source will not work with that
1107 version of udev anymore.
1111 The rule parsing happens now in the daemon once at startup, all udev
1112 event processes inherit the already parsed rules from the daemon.
1113 It is shipped with SUSE10.0 and reduces heavily the system load at
1114 startup. The option to save precompiled rules and let the udev process
1115 pick the them up is removed, as it's no longer needed.
1117 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1118 device. Libsysfs is changed to "translate" the requested link into the
1119 real device path, as it would happen with the hotplug event. Otherwise
1120 device removal and the udev database will not work.
1122 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1125 A few improvements for vol_id, the filesytem probing code.
1129 Fix a stupid typo in extras/run_directory for "make install".
1131 scsi_id creates the temporary devnode now in /dev for usage with a
1132 non-writable /tmp directory.
1134 The uevent kernel socket buffer can carry app. 50.000 events now,
1135 let's see who can break this again. :)
1137 The upcoming kernel will have a new input driver core integration.
1138 Some class devices are now symlinks to the real device. libsysfs
1139 needs a fix for this to work correctly. Udevstart of older udev
1140 versions will _not_ create these devices!
1144 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1149 A bunch of mostly trivial bugfixes. From now on no node name or
1150 symlink name can contain any character than plain whitelisted ascii
1151 characters or validated utf8 byte-streams. This is needed for the
1152 /dev/disk/by-label/* links, because we import untrusted data and
1153 export it to the filesystem.
1157 More bugfixes. If udevd was started from the kernel, we don't
1158 have stdin/stdout/stderr, which broke the forked tools in some
1163 Bugfix. udevstart event ordering was broken for a long time.
1164 The new run_program() uncovered it, because /dev/null was not
1165 available while we try to run external programs.
1166 Now udevstart should create it before we run anything.
1170 Minor bugfixes and some distro rules updates. If you don't have the
1171 persistent disk rules in /dev/disk/by-*/* on your distro, just
1172 grab it from here. :)
1176 We can use socket communication now to pass events from udev to
1178 RUN+="socket:/org/freedesktop/hal/udev_event"
1179 will pass the whole udev event to the HAL daemon without the need
1180 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1184 Mostly bugfixes and see ChangeLog.
1186 The test for the existence of an environment value should be
1188 ENV{KEY}=="*" to ENV{KEY}=="?*"
1189 because "*" will not fail anymore, if the key does not exist or
1194 Bugfixes and a few tweaks described in the ChangeLog.
1198 Mostly a Bugfix release.
1200 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1201 timing with custom rules.
1205 We changed the internal rule storage format. Our large rule files took
1206 2 MB of RAM, with the change we are down to 99kB.
1208 If the device-node has been created with default name and no symlink or
1209 options are to remenber, it is not longer stored in the udevdb. HAL will
1210 need to be updated to work correctly with that change.
1212 To overrride optimization flags, OPTFLAGS may be used now.
1220 Major changes happened with this release. The goal is to take over the
1221 complete kernel-event handling and provide a more efficient way to dispatch
1222 kernel events. Replacing most of the current shell script logic and the
1223 kernel forked helper with a netlink-daemon and a rule-based event handling.
1225 o udevd listens to netlink events now. The first valid netlink event
1226 will make udevd ignore any message from udevsend that contains a
1227 SEQNUM, to avoid duplicate events. The forked events can be disabled
1229 echo "" > /proc/sys/kernel/hotplug
1230 For full support, the broken input-subsytem needs to be fixed, not to
1231 bypass the driver core.
1233 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1234 removed from udev itself and must be emulated by calling small
1235 helper binaries provided in the extras folder:
1236 make EXTRAS=extras/run_directory/
1237 will build udev_run_devd and udev_run_hotplugd, which can be called
1238 from a rule if needed:
1239 RUN+="/sbin/udev_run_hotplugd"
1240 The recommended way to handle this is to convert all the calls from
1241 the directories to explicit udev rules and get completely rid of the
1242 multiplexing. (To catch a ttyUSB event, you now no longer need to
1243 fork and exit 300 tty script instances you are not interested in, it
1244 is just one rule that matches exactly the device.)
1246 o udev handles now _all_ events not just events for class and block
1247 devices, this way it is possible to control the complete event
1248 behavior with udev rules. Especially useful for rules like:
1249 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1251 o As used in the modalias rule, udev supports now textual
1252 substitution placeholder along with the usual format chars. This
1253 needs to be documented, for now it's only visible in udev_rules_parse.c.
1255 o The rule keys support now more operations. This is documented in the
1256 man page. It is possible to add values to list-keys like the SYMLINK
1257 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1258 Also "final"-assignments are supported by using KEY:="value", which will
1259 prevent changing the key by any later rule.
1261 o kernel 2.6.12 has the "detached_state" attribute removed from
1262 sysfs, which was used to recognize sysfs population. We switched that
1263 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1264 Running this udev version on older kernels may cause a short delay for
1267 o To provide infrastructure for persistent device naming, the id programs:
1268 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1269 to export the probed data in environment key format:
1270 pim:~ # /sbin/ata_id --export /dev/hda
1271 ID_MODEL=HTS726060M9AT00
1272 ID_SERIAL=MRH401M4G6UM9B
1273 ID_REVISION=MH4OA6BA
1275 The following rules:
1276 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1277 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1280 kay@pim:~> tree /dev/disk
1283 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1284 | `-- IBM-Memory_Key -> ../../sda
1286 | |-- swap -> ../../hda1
1287 | |-- date -> ../../sda1
1288 | `-- home -> ../../hda3
1290 |-- 2E08712B0870F2E7 -> ../../hda3
1291 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1292 |-- E845-7A89 -> ../../sda1
1293 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1295 The IMPORT= operation will import these keys in the environment and make
1296 it available for later PROGRAM= and RUN= executed programs. The keys are
1297 also stored in the udevdb and can be queried from there with one of the
1300 o A few binaries are silently added to the repository, which can be used
1301 to replay kernel events from initramfs instead of using coldplug. udevd
1302 can be instructed now to queue-up events while the stored events from
1303 initramfs are filled into the udevd-queue. This code is still under
1304 development and there is no documentation now besides the code itself.
1305 The additional binaries get compiled, but are not installed by default.
1307 o There is also a temporary fix for a performance problem where too many
1308 events happen in parallel and every event needs to parse the rules.
1309 udev can now read precompiled rules stored on disk. This is likely to be
1310 replaced by a more elegant solution in a future udev version.
1314 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1315 Fix for libsysfs not to expect this file was added.
1319 All rules are applied now, but only the first matching rule with a NAME-key
1320 will be applied. All later rules with NAME-key are completely ignored. This
1321 way system supplied symlinks or permissions gets applied to user-defined
1325 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1326 to some rules, to keep the old behavior.
1328 The rules are read on "remove"-events too. That makes is possible to match
1329 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1330 instruct udev to ignore an event (OPTIONS="ignore_device").
1331 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1333 The new RUN-key supports rule-based execution of programs after device-node
1334 handling. This is meant as a general replacement for the dev.d/-directories
1335 to give fine grained control over the execution of programs.
1337 The %s{}-sysfs format char replacement values are searched at any of the
1338 devices in the device chain now, not only at the class-device.
1340 We support log priority levels now. The value udev_log in udev.conf is used
1341 to determine what is printed to syslog. This makes it possible to
1342 run a version with compiled-in debug messages in a production environment
1343 which is sometimes needed to find a bug.
1344 It is still possible to supress the inclusion of _any_ syslog usage with
1345 USE_LOG=false to create the smallest possible binaries if needed.
1346 The configured udev_log value can be overridden with the environment variable
1351 Possible use of a system-wide klibc:
1352 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1353 will link against an external klibc and our own version will be ignored.
1357 We support an unlimited count of symlinks now.
1359 If USE_STATIC=true is passed to a glibc build, we link statically and use
1360 a built-in userdb parser to resolve user and group names.
1362 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1363 we walk up the chain of physical devices to find a match.
1365 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1366 easy to skip certain attribute matches without composing rules with weird
1367 character class negations like:
1368 KERNEL="[!s][!c][!d]*"
1369 this can now be replaced with:
1371 The current simple '=' is still supported, and should work as it does today,
1372 but existing rules should be converted if possible, to be better readable.
1374 We have new ENV{}== key now, to match against a maximum of 5 environment
1377 udevstart is its own binary again, because we don't need co carry this araound
1378 with every forked event.
~ianmdlvl / elogind.git / blob