8 Now the udev daemon itself, does on startup:
9 - copy the content of /lib/udev/devices to /dev
10 - create the standard symlinks like /dev/std{in,out,err},
11 /dev/core, /dev/fd, ...
12 - use static node information provided by kernel modules
13 and creates these nodes to allow module on-demand loading
14 - possibly apply permissions to all ststic nodes from udev
15 rules which are annotated to match a static node
17 The default mode for a device node is 0600 now to match the kernel
18 created devtmpfs defaults. If GROUP= is specified and no MODE= is
19 given the default will be 0660.
25 Udev now gradually starts to pass control over the primary device nodes
26 and their names to the kernel, and will in the end only manage the
27 permissions of the node, and possibly create additional symlinks.
28 As a first step NAME="" will be ignored, and NAME= setings with names
29 other than the kernel provided name will result in a logged warning.
30 Kernels that don't provide device names, or devtmpfs is not used, will
31 still work as they did before, but it is strongly recommended to use
32 only the same names for the primary device node as the recent kernel
33 provides for all devices.
37 Fix broken firmware loader search path.
43 "udevadm trigger" defaults to "change" events now instead of "add"
44 events. The "udev boot script" might need to add "--action=add" to
45 the trigger command if not already there, in case the initial coldplug
46 events are expected as "add" events.
48 The option "all_partitons" was removed from udev. This should not be
49 needed for usual hardware. Udev can not safely make assumptions
50 about non-existing partition major/minor numbers, and therefore no
51 longer provide this unreliable and unsafe option.
53 The option "ignore_remove" was removed from udev. With devtmpfs
54 udev passed control over device nodes to the kernel. This option
55 should not be needed, or can not work as advertised. Neither
56 udev nor the kernel will remove device nodes which are copied from
57 the /lib/udev/devices/ directory.
59 All "add|change" matches are replaced by "!remove" in the rules and
60 in the udev logic. All types of events will update possible symlinks
61 and permissions, only "remove" is handled special now.
63 The modem modeswitch extra was removed and the external usb_modeswitch
64 program should be used instead.
66 New and fixed keymaps.
76 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
77 depend on the current sysfs layout and the information not available in the
78 deprecated layout. All remaining support for the deprecated sysfs layout is
83 Fix for a possible endless loop in the new input_id program.
89 The option "ignore_device" does no longer exist. There is no way to
90 ignore an event, as libudev events can not be suppressed by rules.
91 It only prevented RUN keys from being executed, which results in an
92 inconsistent behavior in current setups.
94 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
95 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
98 The support for the deprecated IDE devices has been removed from the
99 default set of rules. Distros who still care about non-libata drivers
100 need to add the rules to the compat rules file.
102 The ID_CLASS property on input devices has been replaced by the more accurate
103 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
104 determined by the new "input_id" prober now. Some devices, such as touchpads,
105 can have several classes. So if you previously had custom udev rules which e. g.
106 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
107 ENV{ID_INPUT_KEYBOARD}=="?*".
113 To support DEVPATH strings larger than the maximum file name length, the
114 private udev database format has changed. If some software still reads the
115 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
116 Please do not port anything to the new format again, everything in /dev/.udev
117 is and always was private to udev, and may and will change any time without
120 Multiple devices claiming the same names in /dev are limited to symlinks
121 only now. Mixing identical symlink names and node names is not supported.
122 This reduces the amount of data in the database significantly.
124 NAME="%k" causes a warning now. It's is and always was completely superfluous.
125 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
128 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
129 if they are not the default. To support older kernels, the NAME= rules need to
130 be added to the compat rules file.
132 Symlinks to udevadm with the old command names are no longer resolved to
133 the udevadm commands.
135 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
138 The option "last_rule" does no longer exist. Its use breaks too many
139 things which expect to be run from independent later rules, and is an idication
140 that something needs to be fixed properly instead.
142 The gudev API is no longer marked as experimental,
143 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
144 is enabled by default now. Various projects already depend on introspection
145 information to bind dynamic languages to the gudev interfaces.
151 The udevadm trigger "--retry-failed" option, which is replaced since quite
152 a while by "--type=failed" is removed.
154 The failed tracking was not working at all for a few releases. The RUN
155 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
156 default is not to track any failing RUN executions.
158 New keymaps, new modem, hid2hci updated.
162 Fix possible crash in udevd when worker processes are busy, rules are
163 changed at the same time, and workers get killed to reload the rules.
169 Properties set with ENV{.FOO}="bar" are marked private by starting the
170 name with a '.'. They will not be stored in the database, and not be
171 exported with the event.
173 Firmware files are looked up in:
174 /lib/firmware/updates/$(uname -r)
175 /lib/firmware/updates
176 /lib/firmware/$(uname -r)
180 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
181 ata_id, instead of scsi_id, is the default tool now for ATA devices.
187 The configure options have changed because another library needs to be
188 installed in a different location. Instead of exec_prefix and udev_prefix,
189 libdir, rootlibdir and libexecdir are used. The Details are explained in
192 Event processes now get re-used after they handled an event. This reduces
193 the number of forks and the pressure on the CPU significantly, because
194 cloned event processes no longer cause page faults in the main daemon.
195 After the events have settled, a few worker processes stay around for
196 future events, all others get cleaned up.
198 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
199 Also inotify support is mandatory now to run udev.
201 The format of the queue exported by the udev damon has changed. There is
202 no longer a /dev/.udev/queue/ directory. The current event queue can be
203 accessed with udevadm settle and libudedv.
205 Libudev does not have the unstable API header anymore. From now on,
206 incompatible changes will be handled by bumping the library major version.
208 To build udev from the git tree gtk-doc is needed now. The tarballs will
209 build without it and contain the pre-built documentation. An online copy
211 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
213 The tools from the udev-extras repository have been merged into the main
214 udev repository. Some of the extras have larger external dependencies, and
215 they can be disabled with the configure switch --disable-extras.
221 The program vol_id and the library libvolume_id are removed from the
222 repository. Libvolume_id is merged with libblkid from the util-linux-ng
223 package. Persistent disk links for label and uuid depend on the
224 util-linux-ng version (2.15) of blkid now. Older versions of blkid
225 can not be used with udev.
227 Libudev allows to subscribe to udev events. To prevent unwanted messages
228 to be delivered, and waking up the subscribing process, a filter can be
229 installed, to drop messages inside a kernel socket filter. The filters
230 match on the <subsytem>:<devtype> properties of the device.
231 This is part of the ongoing effort to replace HAL, and switch current
232 users over to directly use libudev.
233 Libudev is still marked as experimental, and its interface might
234 eventually change if needed, but no major changes of the currently exported
235 interface are expected anymore, and a first stable release should happen
238 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
239 is not supported since while and udevd will log an error message at
240 startup. It should still be able to boot-up, but advanced rules and system
241 services which depend on the information not available in the old sysfs
242 format will fail to work correctly.
244 DVB device naming is supplied by the kernel now. In case older kernels
245 need to be supported, the old shell script should be added to a compat
252 The processed udev events get send back to the netlink socket. Libudev
253 provides access to these events. This is work-in-progress, to replace
254 the DeviceKit daemon functionality directly with libudev. There are
255 upcoming kernel changes to allow non-root users to subcribe to these
262 "udevadm settle" now optionally accepts a range of events to wait for,
263 instead of waiting for "all" events.
269 The installed watch for block device metadata changes is now removed
270 during event hadling, because some (broken) tools may be called from udev
271 rules and (wrongly) open the device with write access. After the finished
272 event handling the watch is restored.
278 Device nodes can be watched for changes with inotify with OPTIONS="watch".
279 If closed after being opened for writing, a "change" uevent will occur.
280 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
286 The udevadm test command has no longer a --force option, nodes and symlinks
287 are always updated with a test run now.
289 The udevd daemon can be started with --resolve-names=never to avoid all user
290 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
291 lookup user and groups every time events are handled.
297 We are currently merging the Ubuntu rules in the udev default rules,
298 and get one step closer to provide a common Linux /dev setup, regarding
299 device names, symlinks, and default device permissions. On udev startup,
300 we now expect the following groups to be resolvable to their ids with
302 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
303 LDAP setups need to make sure, that these groups are always resolvable at
304 bootup, with only the rootfs mounted, and without network access available.
306 Some systems may need to add some new, currently not used groups, or need
307 to add some users to new groups, but the cost of this change is minimal,
308 compared to the pain the current, rather random, differences between the
309 various distributions cause for upstream projects and third-party vendors.
311 In general, "normal" users who log into a machine should never be a member
312 of any such group, but the device-access should be managed by dynamic ACLs,
313 which get added and removed for the specific users on login/logout and
314 session activity/inactivity. These groups are only provided for custom setups,
315 and mainly system services, to allow proper privilege separation.
316 A video-streaming daemon uid would be a member of "audio" and "video", to get
317 access to the sound and video devices, but no "normal" user should ever belong
318 to the "audio" group, because he could listen to the built-in microphone with
319 any ssh-session established from the other side of the world.
321 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
322 which do not depend on the kernel device name. As usual, unique
323 devices - only a single one per product connected, or a real
324 USB serial number in the device - are always found with the same
325 name in the by-id/ directory.
326 Completely identical devices may overwrite their names in by-id/
327 and can only be found reliably in the by-path/ directory. Devices
328 specified by by-path/ must not change their connection, like the
329 USB port number they are plugged in, to keep their name.
331 To support some advanced features, Linux 2.6.22 is the oldest supported
332 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
333 supported. Older kernels should still work, and devices nodes should be
334 reliably created, but some rules and libudev will not work correctly because
335 the old kernels do not provide the expected information or interfaces.
341 Fix for a possible segfault while swapping network interface names in udev
348 The group "video" is part of the default rules now.
352 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
353 block devices in some cases. No common distro uses this option anymore,
354 and we do not get enough testing for this and recent udev versions. If
355 this option is not needed to run some old distro with a new kernel,
356 it should be disabled in the kernel config.
358 Bugfix for the $links substitution variable, which may crash if no links
359 are created. This should not happen in usual setups because we always
360 create /dev/{block,char}/ links.
362 The strings of the parsed rules, which are kept in memory, no longer
363 contain duplicate entries, or duplicate tails of strings. This, and the
364 new rules parsing/matching code reduces the total in-memory size of
365 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
368 The export of DEVTYPE=disk/partition got removed from the default
369 rules. This value is available from the kernel. The pnp shell script
370 modprobe hack is removed from the default rules. ACPI devices have _proper_
371 modalias support and take care of the same functionality.
372 Installations which support old kernels, but install current default
373 udev rules may want to add that to the compat rules file.
375 Libvolume_id now always probes for all known filesystems, and does not
376 stop at the first match. Some filesystems are marked as "exclusive probe",
377 and if any other filesytem type matches at the same time, libvolume_id
378 will, by default, not return any probing result. This is intended to prevent
379 mis-detection with conflicting left-over signatures found from earlier
380 file system formats. That way, we no longer depend on the probe-order
381 in case of multiple competing signatures. In some setups the kernel allows
382 to mount a volume with just the old filesystem signature still in place.
383 This may damage the new filesystem and cause data-loss, just by mounting
384 it. Because volume_id can not decide which one the correct signature is,
385 the wrong signatures need to be removed manually from the volume, or the
386 volume needs to be reformatted, to enable filesystem detection and possible
391 Fix segfault if compiled without optimization and dbg() does not get
392 compiled out and uses variables which are not available.
396 Bugfixes. (And maybe new bugs. :))
398 The rule matching engine got converted from a rule list to a token
399 array which reduced the in-memory rules representation of a full
400 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
401 Limits like 5 ENV and ATTR matches, and one single instance for most
402 other keys per rule are gone.
404 The NAME assignment is no longer special cased. If later rules assign
405 a NAME value again, the former value will be overwritten. As usual
406 for most other keys, the NAME value can be protected by doing a final
407 assignment with NAME:="<value>".
409 All udev code now uses libudev, which is also exported. The library
410 is still under development, marked as experimental, and its interface
411 may change as long as the DeviceKit integration is not finished.
413 Many thanks to Alan Jenkins for his continuous help, and finding and
414 optimizing some of the computing expensive parts.
420 Kernel devices and device nodes are connected now by reverse indizes in
421 /sys and /dev. A device number retrieved by a stat() or similar, the
422 kernel device directory can be found by looking up:
423 /sys/dev/{block,char}/<maj>:<min>
424 and the device node of the same device by looking up:
425 /dev/{block,char}/<maj>:<min>
429 Fix recently introduced bug, which caused a compilation without large
430 file support, where vol_id does not recognize raid signatures at the end
433 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
434 Seems some kernel versions prevent the creation of the ieee-* links,
435 so people used the scsi-* link which disappeared now.
437 More libudev work. Almost all udevadm functionality comes from libudev
440 udevadm trigger has a new option --type, which allows to trigger events
441 for "devices", for "subsystems", or "failed" devices. The old option
442 --retry-failed" still works, but is no longer mentioned in the man page.
448 The udevadm info --device-id-of-file= output has changed to use
449 the obvious format. Possible current users should use the --export
450 option which is not affected.
452 The old udev commands symlinks to udevadm are not installed, if
453 these symlinks are used, a warning is printed.
459 Optical drive's media is no longer probed for raid signatures,
460 reading the end of the device causes some devices to malfunction.
461 Also the offset of the last session found is used now to probe
464 The volume_id library got a major version number update to 1,
465 some deprecated functions are removed.
467 A shared library "libudev" gets installed now to provide access
468 to udev device information. DeviceKit, the successor of HAL, will
469 need this library to access the udev database and search sysfs for
471 The library is currently in an experimental state, also the API is
472 expected to change, as long as the DeviceKit integration is not
477 We use ./configure now. See INSTALL for details. Current
480 "/usr" - prefix for man pages, include files
482 "" - the root filesystem, prefix for libs and binaries
486 "lib" - directory name for libraries, not a path name
487 multilib 64bit systems may use "lib64" instead of "lib"
489 compile-in verbose debug messages
491 disable all logging and compile-out all log strings
493 link against SELInux libraries, to set the expected context
496 In the default rules, the group "disk" gets permissions 0660 instead
497 of 0640. One small step closer to unify distro rules. Some day, all
498 distros hopefully end up with the same set of rules.
500 No symlinks to udevadm are installed anymore, if they are still needed,
501 they should be provided by the package.
507 Default udev rules, which are not supposed to be edited by the user, should
508 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
509 the udev package and will be replaced with an update. Udev will pick up rule
511 /lib/udev/rules.d/ - default installed rules
512 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
513 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
514 It does not matter in which directory a rule file lives, all files are sorted
517 To help creating /dev/root, we have now:
518 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
521 In case the current --device-id-of-file is already used, please switch to
522 the --export format version, it saves the output parsing and the old
523 format will be changed to use ':' as a separator, like the format in the
528 Fix cdrom_id to properly recognize blank media.
534 Tape drive id-data is queried from /dev/bsg/* instead of the tape
535 nodes. This avoids rewinding tapes on open().
541 The symlinks udevcontrol and udevtrigger are no longer installed by
544 The scsi_id program does not depend on sysfs anymore. It can speak
545 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
546 data, which should solve some old problems with tape devices, where
547 we better do not open all tape device nodes to identify the device.
553 The cdrom_id program is replaced by an advanced version, which can
554 detect most common device types, and also properties of the inserted
555 media. This is part of moving some basic functionality from HAL into
556 udev (and the kernel).
562 The last WAIT_FOR_SYSFS rule is removed from the default rules.
564 The symlinks to udevadm for the debugging tools: udevmonitor and
565 udevtest are no longer created.
567 The symlinks to the udevadm man page for the old tool names are
570 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
571 should be prefixed with '@' to indicate that the path is not a
582 Udevstart is removed from the tree, it did not get installed for
583 a long time now, and is long replaced by trigger and settle.
589 All udev tools are merged into a single binary called udevadm.
590 The old names of the tools are built-in commands in udevadm now.
591 Symlinks to udevadm, with the names of the old tools, provide
592 the same functionality as the standalone tools. There is also
593 only a single udevadm.8 man page left for all tools.
595 Tools like mkinitramfs should be checked, if they need to include
596 udevadm in the list of files.
606 The etc/udev/rules.d/ directory now contains a default set of basic
607 udev rules. This initial version is the result of a rules file merge
608 of Fedora and openSUSE. For these both distros only a few specific
609 rules are left in their own file, named after the distro. Rules which
610 are optionally installed, because they are only valid for a specific
611 architecture, or rules for subsystems which are not always used are
612 in etc/udev/packages/.
618 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
619 actions by dynamically created rules.
621 SYMLINK=="<value>" matches agains the entries in the list of
622 currently defined symlinks. The links are not created in the
623 filesystem at that point in time, but the values can be matched.
625 RUN{ignore_error}+="<program>" will ignore any exit code from the
626 program and not record as a failed event.
632 Final merge of patches/features from the Ubuntu package.
638 Control characters in filesystem label strings are no longer silenty
639 removed, but hex-encoded, to be able to uniquely identify the device
640 by its symlink in /dev/disk/by-label/.
641 If libvolume_id is used by mount(8), LABEL= will work as expected,
642 if slashes or other characters are used in the label string.
644 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
645 can be specified now. The TEST key accepts an optional mode mask
646 TEST{0100}=="<is executable file>".
648 Scsi_id now supports a mode without expecting scsi-specific sysfs
649 entries to allow the extraction of cciss-device persistent properties.
655 In the future, we may see uuid's which are just simple character
656 strings (see the DDF Raid Specification). For that reason vol_id now
657 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
658 the creation of symlinks, the *_SAFE values ensure, that no control
659 or whitespace characters are used in the filename.
661 Possible users of libvolume_id, please use the volume_id_get_* functions.
662 The public struct will go away in a future release of the library.
668 Removal of useless extras/eventrecorder.sh.
678 The directory multiplexer for dev.d/ and hotplug.d are finally removed
679 from the udev package.
685 Symlinks can have priorities now, the priority is assigned to the device
686 and specified with OPTIONS="link_priority=100". Devices with higher
687 priorities overwrite the symlinks of devices with lower priorities.
688 If the device that currently owns the link, goes away, the symlink
689 will be removed, and recreated, pointing to the next device with the
690 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
691 more reliable, if multiple devices contain the same metadata and overwrite
694 The dasd_id program is removed from the udev tree, and dasdinfo, with the
695 needed rules, are part of the s390-tools now.
697 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
698 we may get the scsi sysfs mess fixed some day, and this will only catch
699 the devices we are looking for.
701 USB serial numbers for storage devices have the target:lun now appended,
702 to make it possibble to distinguish broken multi-lun devices with all
703 the same SCSI identifiers.
705 Note: The extra "run_directory" which searches and executes stuff in
706 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
707 with the next release. Make sure, that you don't use it anymore, or
708 provides your own implementation of that inefficient stuff.
709 We are tired of reports about a "slow udev", because these directories
710 contain stuff, that runs with _every_ event, instead of using rules,
711 that run programs only for the matching events.
721 DRIVER== will match only for devices that actually have a real
722 driver. DRIVERS== must be used, if parent devices should be
723 included in the match.
725 Libvolume_id's "linux_raid" detection needed another fix.
733 Add additional check to volume_id detection of via_raid, cause
734 some company decided to put a matching pattern all over the empty
735 storage area of their music players.
739 Fix path_id for SAS devices.
743 The udev daemon can be started with --debug-trace now, which will
744 execute all events serialized to get a chance to catch a possible
745 action that crashes the box.
747 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
748 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
749 are excluded from the warning. Referencing parent attributes directly
750 may break when something in the kernel driver model changes. Udev will
751 just find the attribute by walking up the parent chain.
753 Udevtrigger now sorts the list of devices depending on the device
754 dependency, so a "usb" device is triggered after the parent "pci"
759 Revert persistent-storage ata-serial '_' '-' replacement.
765 Udevtrigger can now filter the list of devices to be triggered. Matches
766 for subsystems or sysfs attributes can be specified.
768 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
769 zero-sized files to avoid pointing to /sys and confuse broken tools which
770 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
773 The rules and scripts to create udev rules for persistent network
774 devices and optical drives are in the extras/rules_generator directory
775 now. If you use something similar, please consider replacing your own
776 version with this, to share the support effort. The rule_generator
777 installs its own rules into /etc/udev/rules.d.
779 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
780 the rule_generator depends on cdrom_id to be called in an earlier rule.
786 Renaming of some key names (the old names still work):
787 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
788 (The behavior of the key DRIVER will change soon in one of the next
789 releases, to match only the event device, please switch to DRIVERS
790 instead. If DRIVER is used, it will behave like DRIVERS, but an error
792 With the new key names, we have a more consistent and simpler scheme.
793 We can match the properties of the event device only, with: KERNEL,
794 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
795 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
796 longer mentioned in the man page and should be switched in the rule
799 ATTR{file}="value" can be used now, to write to a sysfs file of the
800 event device. Instead of:
801 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
803 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
805 All the PHYSDEV* keys are deprecated and will be removed from a
807 PHYDEVPATH - is the path of a parent device and should not be
809 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
810 matched with SUBSYSTEMS==
811 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
812 Newer kernels will have DRIVER in the environment,
813 for older kernels udev puts in. Class device will
814 no longer carry this property of a parent and
815 DRIVERS== can be used to match such a parent value.
816 Note that ENV{DRIVER} is only available for a few bus devices, where
817 the driver is already bound at device event time. On coldplug, the
818 events for a lot devices are already bound to a driver, and they will have
819 that value set. But on hotplug, at the time the kernel creates the device,
820 it can't know what driver may claim the device after that, therefore
821 in most cases it will be empty.
823 Failed events should now be re-triggered with:
824 udevtrigger --retry-failed.
825 Please switch to this command, so we keep the details of the /dev/.udev/failed/
826 files private to the udev tools. We may need to switch the current symlink
827 target, cause some obviously broken tools try to scan all files in /dev
828 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
829 million times. This takes ages on slow boxes.
831 The udevinfo attribute walk (-a) now works with giving a device node
832 name (-n) instead of a devpath (-p). The query now always works, also when
833 no database file was created by udev.
835 The built-in /etc/passwd /etc/group parser is removed, we always depend on
836 getpwnam() and getgrnam() now. One of the next releases will depend on
837 fnmatch() and may use getopt_long().
841 Bugfixes and small improvements.
845 Fix path_id for recent kernels.
851 Added support for swapping network interface names, by temporarily
852 renaming the device and wait for the target name to become free.
856 The built-in MODALIAS key and substitution is removed.
860 The binary firmware helper is replaced by the usual simple
861 shell script. Udevsend is removed from the tree.
869 Some more keys require the correct use of '==' and '=' depending
870 on the kind of operation beeing an assignment or a match. Rules
871 with invalid operations are skipped and logged to syslog. Please
872 test with udevtest if the parsing of your rules throws errors and
873 fix possibly broken rules.
877 Provide "udevsettle" to wait for all current udev events to finish.
878 It also watches the current kernel netlink queue by comparing the
879 even sequence number to make sure that there are no current pending
880 events that have not already arrived in the daemon.
884 Fix rule to skip persistent rules for removable IDE devices, which
885 also skipped optical IDE drives.
887 All *_id program are installed in /lib/udev/ by default now.
889 No binary is stripped anymore as this should be done in the
890 packaging process and not at build time.
892 libvolume_id is provided as a shared library now and vol_id is
893 linked against it. Also one of the next HAL versions will require
894 this library, and the HAL build process will also require the
895 header file to be installed. The copy of the same code in HAL will
896 be removed to have only a single copy left on the system.
900 Add persistent links for SCSI tapes. The rules file is renamed
901 to 60-persistent-storage.rules.
903 Create persistent path for usb devices. Can be used for all sorts
904 of devices that can't be distinguished by other properties like
905 multiple identical keyboards and mice connected to the same box.
907 Provide "udevtrigger" program to request events on coldplug. The
908 shell script is much too slow with thousends of devices.
912 Fix persistent disk rules to exclude removable IDE drives.
914 Warn if %e, $modalias or MODALIAS is used.
918 Fix queue export, which wasn't correct for subsequent add/remove
919 events for the same device.
923 Fix cramfs detection on big endian.
925 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
930 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
931 attributes were only checked at the parent device that matched the
932 by BUS requested subsystem. Fix it to also look at the device we
933 received the event for.
935 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
940 Fix a bug where NAME="" would prevent RUN from beeing executed.
942 RUN="/bin/program" does not longer automatically add the subsystem
943 as the first parameter. This is from the days of /sbin/hotplug
944 which is dead now and it's just confusing to need to add a space at
945 the end of the program name to prevent this.
946 If you use rules that need the subsystem as the first parameter,
947 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
948 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
952 The udev man page has moved to udev(7) as it does not describe a command
953 anymore. The programs udev, udevstart and udevsend are no longer installed
954 by default and must be copied manually, if they should be installed or
955 included in a package.
957 Fix a bug where "ignore_device" could run earlier collected RUN keys before
958 the ignore rule was applied.
960 More preparation for future sysfs changes. usb_id and scsi_id no longer
961 depend on a magic order of devices in the /devices chain. Specific devices
962 should be requested by their subsytem.
964 This will always find the scsi parent device without depending on a specific
966 dev = sysfs_device_get(devpath);
967 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
969 The "device" link in the current sysfs layout will be automatically
970 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
971 parent in the devpath. If a device is requested by it's symlink, like all
972 class devices in the new sysfs layout will look like, it gets automatically
973 resolved and substituted with the real devpath and not the symlink path.
976 A similar logic must be applied to _all_ sysfs users, including
977 scripts, that search along parent devices in sysfs. The explicit use of
978 the "device" link must be avoided. With the future sysfs layout all
979 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
980 back to the "class" or the "bus". The layout of the parent devices in
981 /devices is not necessarily expected to be stable across kernel releases and
982 searching for parents by their subsystem should make sysfs users tolerant
983 for changed parent chains.
987 Prepare udev to work with the experimental kernel patch, that moves
988 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
990 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
991 moving the class devices to /sys/devices.
993 Thanks again to Marco for help finding a hopefully nice compromise
994 to make %b simpler and working again.
998 Complete removal of libsysfs, replaced by simple helper functions
999 which are much simpler and a bit faster. The udev daemon operatesentirely
1000 on event parameters and does not use sysfs for simple rules anymore.
1001 Please report any new bugs/problems, that may be caused by this big
1002 change. They will be fixed immediately.
1004 The enumeration format character '%e' is deprecated and will be
1005 removed sometimes from a future udev version. It never worked correctly
1006 outside of udevstart, so we can't use it with the new parallel
1007 coldplug. A simple enumeration is as useless as the devfs naming
1008 scheme, just get rid of both if you still use it.
1010 MODALIAS and $modalias is not needed and will be removed from one of
1011 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1012 the sysfs "modalias" value.
1014 Thanks a lot to Marco for all his help on finding and fixing bugs.
1018 Let scsi_id request libata drive serial numbers from page 0x80.
1020 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1021 added /dev/disk/by-name/* for device mapper device names.
1023 Removed %e from the man page. It never worked reliably outside
1024 of udevstart and udevstart is no longer recommended to use.
1028 Symlinks are now exported to the event environment. Hopefully it's no
1029 longer needed to run udevinfo from an event process, like it was
1030 mentioned on the hotplug list:
1031 UDEV [1134776873.702967] add@/block/sdb
1034 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1038 Fix a problem if udevsend is used as the hotplug handler and tries to use
1039 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1040 and this kind of problems will hopefully go away soon.
1044 All built-in logic to work around bad sysfs timing is removed with this
1045 version. The need to wait for sysfs files is almost fixed with a kernel
1046 version that doesn't work with this udev version anyway. Until we fix
1047 the timing of the "bus" link creation, the former integrated logic should
1048 be emulated by a rule placed before all other rules:
1049 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1051 The option "udev_db" does no longer exist. All udev state will be in
1052 /$udev_root/.udev/ now, there is no longer an option to set this
1054 If the init script or something else used this value, just depend on
1055 this hardcoded path. But remember _all_content_ of this directory is
1056 still private to udev and can change at any time.
1058 Default location for rule sripts and helper programs is now: /lib/udev/.
1059 Everything that is not useful on the commandline should go into this
1060 directory. Some of the helpers in the extras folder are installed there
1061 now. The rules need to be changed, to find the helpers there.
1063 Also /lib/udev/devices is recommended as a directory where packages or
1064 the user can place real device nodes, which get copied over to /dev at
1065 every boot. This should replace the various solutions with custom config
1068 Udevsend does no longer start the udev daemon. This must be done with
1069 the init script that prepares /dev on tmpfs and creates the initial nodes,
1070 before starting the daemon.
1074 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1077 The copy of klibc is removed. A systemwide installed version of klibc
1078 should be used to build a klibc udev now.
1082 NAME="" will not create any nodes, but execute RUN keys. To completely
1083 ignore an event the OPTION "ignore_device" should be used.
1085 After removal of the reorder queue, events with a TIMEOUT can be executed
1086 without any queuing now.
1090 Fixed bug in udevd, if inotify is not available. We depend on netlink
1091 uevents now, kernels without that event source will not work with that
1092 version of udev anymore.
1096 The rule parsing happens now in the daemon once at startup, all udev
1097 event processes inherit the already parsed rules from the daemon.
1098 It is shipped with SUSE10.0 and reduces heavily the system load at
1099 startup. The option to save precompiled rules and let the udev process
1100 pick the them up is removed, as it's no longer needed.
1102 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1103 device. Libsysfs is changed to "translate" the requested link into the
1104 real device path, as it would happen with the hotplug event. Otherwise
1105 device removal and the udev database will not work.
1107 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1110 A few improvements for vol_id, the filesytem probing code.
1114 Fix a stupid typo in extras/run_directory for "make install".
1116 scsi_id creates the temporary devnode now in /dev for usage with a
1117 non-writable /tmp directory.
1119 The uevent kernel socket buffer can carry app. 50.000 events now,
1120 let's see who can break this again. :)
1122 The upcoming kernel will have a new input driver core integration.
1123 Some class devices are now symlinks to the real device. libsysfs
1124 needs a fix for this to work correctly. Udevstart of older udev
1125 versions will _not_ create these devices!
1129 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1134 A bunch of mostly trivial bugfixes. From now on no node name or
1135 symlink name can contain any character than plain whitelisted ascii
1136 characters or validated utf8 byte-streams. This is needed for the
1137 /dev/disk/by-label/* links, because we import untrusted data and
1138 export it to the filesystem.
1142 More bugfixes. If udevd was started from the kernel, we don't
1143 have stdin/stdout/stderr, which broke the forked tools in some
1148 Bugfix. udevstart event ordering was broken for a long time.
1149 The new run_program() uncovered it, because /dev/null was not
1150 available while we try to run external programs.
1151 Now udevstart should create it before we run anything.
1155 Minor bugfixes and some distro rules updates. If you don't have the
1156 persistent disk rules in /dev/disk/by-*/* on your distro, just
1157 grab it from here. :)
1161 We can use socket communication now to pass events from udev to
1163 RUN+="socket:/org/freedesktop/hal/udev_event"
1164 will pass the whole udev event to the HAL daemon without the need
1165 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1169 Mostly bugfixes and see ChangeLog.
1171 The test for the existence of an environment value should be
1173 ENV{KEY}=="*" to ENV{KEY}=="?*"
1174 because "*" will not fail anymore, if the key does not exist or
1179 Bugfixes and a few tweaks described in the ChangeLog.
1183 Mostly a Bugfix release.
1185 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1186 timing with custom rules.
1190 We changed the internal rule storage format. Our large rule files took
1191 2 MB of RAM, with the change we are down to 99kB.
1193 If the device-node has been created with default name and no symlink or
1194 options are to remenber, it is not longer stored in the udevdb. HAL will
1195 need to be updated to work correctly with that change.
1197 To overrride optimization flags, OPTFLAGS may be used now.
1205 Major changes happened with this release. The goal is to take over the
1206 complete kernel-event handling and provide a more efficient way to dispatch
1207 kernel events. Replacing most of the current shell script logic and the
1208 kernel forked helper with a netlink-daemon and a rule-based event handling.
1210 o udevd listens to netlink events now. The first valid netlink event
1211 will make udevd ignore any message from udevsend that contains a
1212 SEQNUM, to avoid duplicate events. The forked events can be disabled
1214 echo "" > /proc/sys/kernel/hotplug
1215 For full support, the broken input-subsytem needs to be fixed, not to
1216 bypass the driver core.
1218 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1219 removed from udev itself and must be emulated by calling small
1220 helper binaries provided in the extras folder:
1221 make EXTRAS=extras/run_directory/
1222 will build udev_run_devd and udev_run_hotplugd, which can be called
1223 from a rule if needed:
1224 RUN+="/sbin/udev_run_hotplugd"
1225 The recommended way to handle this is to convert all the calls from
1226 the directories to explicit udev rules and get completely rid of the
1227 multiplexing. (To catch a ttyUSB event, you now no longer need to
1228 fork and exit 300 tty script instances you are not interested in, it
1229 is just one rule that matches exactly the device.)
1231 o udev handles now _all_ events not just events for class and block
1232 devices, this way it is possible to control the complete event
1233 behavior with udev rules. Especially useful for rules like:
1234 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1236 o As used in the modalias rule, udev supports now textual
1237 substitution placeholder along with the usual format chars. This
1238 needs to be documented, for now it's only visible in udev_rules_parse.c.
1240 o The rule keys support now more operations. This is documented in the
1241 man page. It is possible to add values to list-keys like the SYMLINK
1242 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1243 Also "final"-assignments are supported by using KEY:="value", which will
1244 prevent changing the key by any later rule.
1246 o kernel 2.6.12 has the "detached_state" attribute removed from
1247 sysfs, which was used to recognize sysfs population. We switched that
1248 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1249 Running this udev version on older kernels may cause a short delay for
1252 o To provide infrastructure for persistent device naming, the id programs:
1253 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1254 to export the probed data in environment key format:
1255 pim:~ # /sbin/ata_id --export /dev/hda
1256 ID_MODEL=HTS726060M9AT00
1257 ID_SERIAL=MRH401M4G6UM9B
1258 ID_REVISION=MH4OA6BA
1260 The following rules:
1261 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1262 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1265 kay@pim:~> tree /dev/disk
1268 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1269 | `-- IBM-Memory_Key -> ../../sda
1271 | |-- swap -> ../../hda1
1272 | |-- date -> ../../sda1
1273 | `-- home -> ../../hda3
1275 |-- 2E08712B0870F2E7 -> ../../hda3
1276 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1277 |-- E845-7A89 -> ../../sda1
1278 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1280 The IMPORT= operation will import these keys in the environment and make
1281 it available for later PROGRAM= and RUN= executed programs. The keys are
1282 also stored in the udevdb and can be queried from there with one of the
1285 o A few binaries are silently added to the repository, which can be used
1286 to replay kernel events from initramfs instead of using coldplug. udevd
1287 can be instructed now to queue-up events while the stored events from
1288 initramfs are filled into the udevd-queue. This code is still under
1289 development and there is no documentation now besides the code itself.
1290 The additional binaries get compiled, but are not installed by default.
1292 o There is also a temporary fix for a performance problem where too many
1293 events happen in parallel and every event needs to parse the rules.
1294 udev can now read precompiled rules stored on disk. This is likely to be
1295 replaced by a more elegant solution in a future udev version.
1299 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1300 Fix for libsysfs not to expect this file was added.
1304 All rules are applied now, but only the first matching rule with a NAME-key
1305 will be applied. All later rules with NAME-key are completely ignored. This
1306 way system supplied symlinks or permissions gets applied to user-defined
1310 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1311 to some rules, to keep the old behavior.
1313 The rules are read on "remove"-events too. That makes is possible to match
1314 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1315 instruct udev to ignore an event (OPTIONS="ignore_device").
1316 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1318 The new RUN-key supports rule-based execution of programs after device-node
1319 handling. This is meant as a general replacement for the dev.d/-directories
1320 to give fine grained control over the execution of programs.
1322 The %s{}-sysfs format char replacement values are searched at any of the
1323 devices in the device chain now, not only at the class-device.
1325 We support log priority levels now. The value udev_log in udev.conf is used
1326 to determine what is printed to syslog. This makes it possible to
1327 run a version with compiled-in debug messages in a production environment
1328 which is sometimes needed to find a bug.
1329 It is still possible to supress the inclusion of _any_ syslog usage with
1330 USE_LOG=false to create the smallest possible binaries if needed.
1331 The configured udev_log value can be overridden with the environment variable
1336 Possible use of a system-wide klibc:
1337 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1338 will link against an external klibc and our own version will be ignored.
1342 We support an unlimited count of symlinks now.
1344 If USE_STATIC=true is passed to a glibc build, we link statically and use
1345 a built-in userdb parser to resolve user and group names.
1347 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1348 we walk up the chain of physical devices to find a match.
1350 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1351 easy to skip certain attribute matches without composing rules with weird
1352 character class negations like:
1353 KERNEL="[!s][!c][!d]*"
1354 this can now be replaced with:
1356 The current simple '=' is still supported, and should work as it does today,
1357 but existing rules should be converted if possible, to be better readable.
1359 We have new ENV{}== key now, to match against a maximum of 5 environment
1362 udevstart is its own binary again, because we don't need co carry this araound
1363 with every forked event.
~ianmdlvl / elogind.git / blob