3 New keymaps, new modem, hid2hci updated.
8 Fix possible crash in udevd when worker processes are busy, rules are
9 changed at the same time, and workers get killed to reload the rules.
15 Properties set with ENV{.FOO}="bar" are marked private by starting the
16 name with a '.'. They will not be stored in the database, and not be
17 exported with the event.
19 Firmware files are looked up in:
20 /lib/firmware/updates/$(uname -r)
22 /lib/firmware/$(uname -r)
26 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
27 ata_id, instead of scsi_id, is the default tool now for ATA devices.
33 The configure options have changed because another library needs to be
34 installed in a different location. Instead of exec_prefix and udev_prefix,
35 libdir, rootlibdir and libexecdir are used. The Details are explained in
38 Event processes now get re-used after they handled an event. This reduces
39 the number of forks and the pressure on the CPU significantly, because
40 cloned event processes no longer cause page faults in the main daemon.
41 After the events have settled, a few worker processes stay around for
42 future events, all others get cleaned up.
44 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
45 Also inotify support is mandatory now to run udev.
47 The format of the queue exported by the udev damon has changed. There is
48 no longer a /dev/.udev/queue/ directory. The current event queue can be
49 accessed with udevadm settle and libudedv.
51 Libudev does not have the unstable API header anymore. From now on,
52 incompatible changes will be handled by bumping the library major version.
54 To build udev from the git tree gtk-doc is needed now. The tarballs will
55 build without it and contain the pre-built documentation. An online copy
57 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
59 The tools from the udev-extras repository have been merged into the main
60 udev repository. Some of the extras have larger external dependencies, and
61 they can be disabled with the configure switch --disable-extras.
67 The program vol_id and the library libvolume_id are removed from the
68 repository. Libvolume_id is merged with libblkid from the util-linux-ng
69 package. Persistent disk links for label and uuid depend on the
70 util-linux-ng version (2.15) of blkid now. Older versions of blkid
71 can not be used with udev.
73 Libudev allows to subscribe to udev events. To prevent unwanted messages
74 to be delivered, and waking up the subscribing process, a filter can be
75 installed, to drop messages inside a kernel socket filter. The filters
76 match on the <subsytem>:<devtype> properties of the device.
77 This is part of the ongoing effort to replace HAL, and switch current
78 users over to directly use libudev.
79 Libudev is still marked as experimental, and its interface might
80 eventually change if needed, but no major changes of the currently exported
81 interface are expected anymore, and a first stable release should happen
84 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
85 is not supported since while and udevd will log an error message at
86 startup. It should still be able to boot-up, but advanced rules and system
87 services which depend on the information not available in the old sysfs
88 format will fail to work correctly.
90 DVB device naming is supplied by the kernel now. In case older kernels
91 need to be supported, the old shell script should be added to a compat
98 The processed udev events get send back to the netlink socket. Libudev
99 provides access to these events. This is work-in-progress, to replace
100 the DeviceKit daemon functionality directly with libudev. There are
101 upcoming kernel changes to allow non-root users to subcribe to these
108 "udevadm settle" now optionally accepts a range of events to wait for,
109 instead of waiting for "all" events.
115 The installed watch for block device metadata changes is now removed
116 during event hadling, because some (broken) tools may be called from udev
117 rules and (wrongly) open the device with write access. After the finished
118 event handling the watch is restored.
124 Device nodes can be watched for changes with inotify with OPTIONS="watch".
125 If closed after being opened for writing, a "change" uevent will occur.
126 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
132 The udevadm test command has no longer a --force option, nodes and symlinks
133 are always updated with a test run now.
135 The udevd daemon can be started with --resolve-names=never to avoid all user
136 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
137 lookup user and groups every time events are handled.
143 We are currently merging the Ubuntu rules in the udev default rules,
144 and get one step closer to provide a common Linux /dev setup, regarding
145 device names, symlinks, and default device permissions. On udev startup,
146 we now expect the following groups to be resolvable to their ids with
148 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
149 LDAP setups need to make sure, that these groups are always resolvable at
150 bootup, with only the rootfs mounted, and without network access available.
152 Some systems may need to add some new, currently not used groups, or need
153 to add some users to new groups, but the cost of this change is minimal,
154 compared to the pain the current, rather random, differences between the
155 various distributions cause for upstream projects and third-party vendors.
157 In general, "normal" users who log into a machine should never be a member
158 of any such group, but the device-access should be managed by dynamic ACLs,
159 which get added and removed for the specific users on login/logout and
160 session activity/inactivity. These groups are only provided for custom setups,
161 and mainly system services, to allow proper privilege separation.
162 A video-streaming daemon uid would be a member of "audio" and "video", to get
163 access to the sound and video devices, but no "normal" user should ever belong
164 to the "audio" group, because he could listen to the built-in microphone with
165 any ssh-session established from the other side of the world.
167 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
168 which do not depend on the kernel device name. As usual, unique
169 devices - only a single one per product connected, or a real
170 USB serial number in the device - are always found with the same
171 name in the by-id/ directory.
172 Completely identical devices may overwrite their names in by-id/
173 and can only be found reliably in the by-path/ directory. Devices
174 specified by by-path/ must not change their connection, like the
175 USB port number they are plugged in, to keep their name.
177 To support some advanced features, Linux 2.6.22 is the oldest supported
178 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
179 supported. Older kernels should still work, and devices nodes should be
180 reliably created, but some rules and libudev will not work correctly because
181 the old kernels do not provide the expected information or interfaces.
187 Fix for a possible segfault while swapping network interface names in udev
194 The group "video" is part of the default rules now.
198 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
199 block devices in some cases. No common distro uses this option anymore,
200 and we do not get enough testing for this and recent udev versions. If
201 this option is not needed to run some old distro with a new kernel,
202 it should be disabled in the kernel config.
204 Bugfix for the $links substitution variable, which may crash if no links
205 are created. This should not happen in usual setups because we always
206 create /dev/{block,char}/ links.
208 The strings of the parsed rules, which are kept in memory, no longer
209 contain duplicate entries, or duplicate tails of strings. This, and the
210 new rules parsing/matching code reduces the total in-memory size of
211 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
214 The export of DEVTYPE=disk/partition got removed from the default
215 rules. This value is available from the kernel. The pnp shell script
216 modprobe hack is removed from the default rules. ACPI devices have _proper_
217 modalias support and take care of the same functionality.
218 Installations which support old kernels, but install current default
219 udev rules may want to add that to the compat rules file.
221 Libvolume_id now always probes for all known filesystems, and does not
222 stop at the first match. Some filesystems are marked as "exclusive probe",
223 and if any other filesytem type matches at the same time, libvolume_id
224 will, by default, not return any probing result. This is intended to prevent
225 mis-detection with conflicting left-over signatures found from earlier
226 file system formats. That way, we no longer depend on the probe-order
227 in case of multiple competing signatures. In some setups the kernel allows
228 to mount a volume with just the old filesystem signature still in place.
229 This may damage the new filesystem and cause data-loss, just by mounting
230 it. Because volume_id can not decide which one the correct signature is,
231 the wrong signatures need to be removed manually from the volume, or the
232 volume needs to be reformatted, to enable filesystem detection and possible
237 Fix segfault if compiled without optimization and dbg() does not get
238 compiled out and uses variables which are not available.
242 Bugfixes. (And maybe new bugs. :))
244 The rule matching engine got converted from a rule list to a token
245 array which reduced the in-memory rules representation of a full
246 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
247 Limits like 5 ENV and ATTR matches, and one single instance for most
248 other keys per rule are gone.
250 The NAME assignment is no longer special cased. If later rules assign
251 a NAME value again, the former value will be overwritten. As usual
252 for most other keys, the NAME value can be protected by doing a final
253 assignment with NAME:="<value>".
255 All udev code now uses libudev, which is also exported. The library
256 is still under development, marked as experimental, and its interface
257 may change as long as the DeviceKit integration is not finished.
259 Many thanks to Alan Jenkins for his continuous help, and finding and
260 optimizing some of the computing expensive parts.
266 Kernel devices and device nodes are connected now by reverse indizes in
267 /sys and /dev. A device number retrieved by a stat() or similar, the
268 kernel device directory can be found by looking up:
269 /sys/dev/{block,char}/<maj>:<min>
270 and the device node of the same device by looking up:
271 /dev/{block,char}/<maj>:<min>
275 Fix recently introduced bug, which caused a compilation without large
276 file support, where vol_id does not recognize raid signatures at the end
279 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
280 Seems some kernel versions prevent the creation of the ieee-* links,
281 so people used the scsi-* link which disappeared now.
283 More libudev work. Almost all udevadm functionality comes from libudev
286 udevadm trigger has a new option --type, which allows to trigger events
287 for "devices", for "subsystems", or "failed" devices. The old option
288 --retry-failed" still works, but is no longer mentioned in the man page.
294 The udevadm info --device-id-of-file= output has changed to use
295 the obvious format. Possible current users should use the --export
296 option which is not affected.
298 The old udev commands symlinks to udevadm are not installed, if
299 these symlinks are used, a warning is printed.
305 Optical drive's media is no longer probed for raid signatures,
306 reading the end of the device causes some devices to malfunction.
307 Also the offset of the last session found is used now to probe
310 The volume_id library got a major version number update to 1,
311 some deprecated functions are removed.
313 A shared library "libudev" gets installed now to provide access
314 to udev device information. DeviceKit, the successor of HAL, will
315 need this library to access the udev database and search sysfs for
317 The library is currently in an experimental state, also the API is
318 expected to change, as long as the DeviceKit integration is not
323 We use ./configure now. See INSTALL for details. Current
326 "/usr" - prefix for man pages, include files
328 "" - the root filesystem, prefix for libs and binaries
332 "lib" - directory name for libraries, not a path name
333 multilib 64bit systems may use "lib64" instead of "lib"
335 compile-in verbose debug messages
337 disable all logging and compile-out all log strings
339 link against SELInux libraries, to set the expected context
342 In the default rules, the group "disk" gets permissions 0660 instead
343 of 0640. One small step closer to unify distro rules. Some day, all
344 distros hopefully end up with the same set of rules.
346 No symlinks to udevadm are installed anymore, if they are still needed,
347 they should be provided by the package.
353 Default udev rules, which are not supposed to be edited by the user, should
354 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
355 the udev package and will be replaced with an update. Udev will pick up rule
357 /lib/udev/rules.d/ - default installed rules
358 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
359 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
360 It does not matter in which directory a rule file lives, all files are sorted
363 To help creating /dev/root, we have now:
364 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
367 In case the current --device-id-of-file is already used, please switch to
368 the --export format version, it saves the output parsing and the old
369 format will be changed to use ':' as a separator, like the format in the
374 Fix cdrom_id to properly recognize blank media.
380 Tape drive id-data is queried from /dev/bsg/* instead of the tape
381 nodes. This avoids rewinding tapes on open().
387 The symlinks udevcontrol and udevtrigger are no longer installed by
390 The scsi_id program does not depend on sysfs anymore. It can speak
391 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
392 data, which should solve some old problems with tape devices, where
393 we better do not open all tape device nodes to identify the device.
399 The cdrom_id program is replaced by an advanced version, which can
400 detect most common device types, and also properties of the inserted
401 media. This is part of moving some basic functionality from HAL into
402 udev (and the kernel).
408 The last WAIT_FOR_SYSFS rule is removed from the default rules.
410 The symlinks to udevadm for the debugging tools: udevmonitor and
411 udevtest are no longer created.
413 The symlinks to the udevadm man page for the old tool names are
416 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
417 should be prefixed with '@' to indicate that the path is not a
428 Udevstart is removed from the tree, it did not get installed for
429 a long time now, and is long replaced by trigger and settle.
435 All udev tools are merged into a single binary called udevadm.
436 The old names of the tools are built-in commands in udevadm now.
437 Symlinks to udevadm, with the names of the old tools, provide
438 the same functionality as the standalone tools. There is also
439 only a single udevadm.8 man page left for all tools.
441 Tools like mkinitramfs should be checked, if they need to include
442 udevadm in the list of files.
452 The etc/udev/rules.d/ directory now contains a default set of basic
453 udev rules. This initial version is the result of a rules file merge
454 of Fedora and openSUSE. For these both distros only a few specific
455 rules are left in their own file, named after the distro. Rules which
456 are optionally installed, because they are only valid for a specific
457 architecture, or rules for subsystems which are not always used are
458 in etc/udev/packages/.
464 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
465 actions by dynamically created rules.
467 SYMLINK=="<value>" matches agains the entries in the list of
468 currently defined symlinks. The links are not created in the
469 filesystem at that point in time, but the values can be matched.
471 RUN{ignore_error}+="<program>" will ignore any exit code from the
472 program and not record as a failed event.
478 Final merge of patches/features from the Ubuntu package.
484 Control characters in filesystem label strings are no longer silenty
485 removed, but hex-encoded, to be able to uniquely identify the device
486 by its symlink in /dev/disk/by-label/.
487 If libvolume_id is used by mount(8), LABEL= will work as expected,
488 if slashes or other characters are used in the label string.
490 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
491 can be specified now. The TEST key accepts an optional mode mask
492 TEST{0100}=="<is executable file>".
494 Scsi_id now supports a mode without expecting scsi-specific sysfs
495 entries to allow the extraction of cciss-device persistent properties.
501 In the future, we may see uuid's which are just simple character
502 strings (see the DDF Raid Specification). For that reason vol_id now
503 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
504 the creation of symlinks, the *_SAFE values ensure, that no control
505 or whitespace characters are used in the filename.
507 Possible users of libvolume_id, please use the volume_id_get_* functions.
508 The public struct will go away in a future release of the library.
514 Removal of useless extras/eventrecorder.sh.
524 The directory multiplexer for dev.d/ and hotplug.d are finally removed
525 from the udev package.
531 Symlinks can have priorities now, the priority is assigned to the device
532 and specified with OPTIONS="link_priority=100". Devices with higher
533 priorities overwrite the symlinks of devices with lower priorities.
534 If the device that currently owns the link, goes away, the symlink
535 will be removed, and recreated, pointing to the next device with the
536 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
537 more reliable, if multiple devices contain the same metadata and overwrite
540 The dasd_id program is removed from the udev tree, and dasdinfo, with the
541 needed rules, are part of the s390-tools now.
543 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
544 we may get the scsi sysfs mess fixed some day, and this will only catch
545 the devices we are looking for.
547 USB serial numbers for storage devices have the target:lun now appended,
548 to make it possibble to distinguish broken multi-lun devices with all
549 the same SCSI identifiers.
551 Note: The extra "run_directory" which searches and executes stuff in
552 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
553 with the next release. Make sure, that you don't use it anymore, or
554 provides your own implementation of that inefficient stuff.
555 We are tired of reports about a "slow udev", because these directories
556 contain stuff, that runs with _every_ event, instead of using rules,
557 that run programs only for the matching events.
567 DRIVER== will match only for devices that actually have a real
568 driver. DRIVERS== must be used, if parent devices should be
569 included in the match.
571 Libvolume_id's "linux_raid" detection needed another fix.
579 Add additional check to volume_id detection of via_raid, cause
580 some company decided to put a matching pattern all over the empty
581 storage area of their music players.
585 Fix path_id for SAS devices.
589 The udev daemon can be started with --debug-trace now, which will
590 execute all events serialized to get a chance to catch a possible
591 action that crashes the box.
593 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
594 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
595 are excluded from the warning. Referencing parent attributes directly
596 may break when something in the kernel driver model changes. Udev will
597 just find the attribute by walking up the parent chain.
599 Udevtrigger now sorts the list of devices depending on the device
600 dependency, so a "usb" device is triggered after the parent "pci"
605 Revert persistent-storage ata-serial '_' '-' replacement.
611 Udevtrigger can now filter the list of devices to be triggered. Matches
612 for subsystems or sysfs attributes can be specified.
614 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
615 zero-sized files to avoid pointing to /sys and confuse broken tools which
616 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
619 The rules and scripts to create udev rules for persistent network
620 devices and optical drives are in the extras/rules_generator directory
621 now. If you use something similar, please consider replacing your own
622 version with this, to share the support effort. The rule_generator
623 installs its own rules into /etc/udev/rules.d.
625 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
626 the rule_generator depends on cdrom_id to be called in an earlier rule.
632 Renaming of some key names (the old names still work):
633 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
634 (The behavior of the key DRIVER will change soon in one of the next
635 releases, to match only the event device, please switch to DRIVERS
636 instead. If DRIVER is used, it will behave like DRIVERS, but an error
638 With the new key names, we have a more consistent and simpler scheme.
639 We can match the properties of the event device only, with: KERNEL,
640 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
641 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
642 longer mentioned in the man page and should be switched in the rule
645 ATTR{file}="value" can be used now, to write to a sysfs file of the
646 event device. Instead of:
647 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
649 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
651 All the PHYSDEV* keys are deprecated and will be removed from a
653 PHYDEVPATH - is the path of a parent device and should not be
655 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
656 matched with SUBSYSTEMS==
657 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
658 Newer kernels will have DRIVER in the environment,
659 for older kernels udev puts in. Class device will
660 no longer carry this property of a parent and
661 DRIVERS== can be used to match such a parent value.
662 Note that ENV{DRIVER} is only available for a few bus devices, where
663 the driver is already bound at device event time. On coldplug, the
664 events for a lot devices are already bound to a driver, and they will have
665 that value set. But on hotplug, at the time the kernel creates the device,
666 it can't know what driver may claim the device after that, therefore
667 in most cases it will be empty.
669 Failed events should now be re-triggered with:
670 udevtrigger --retry-failed.
671 Please switch to this command, so we keep the details of the /dev/.udev/failed/
672 files private to the udev tools. We may need to switch the current symlink
673 target, cause some obviously broken tools try to scan all files in /dev
674 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
675 million times. This takes ages on slow boxes.
677 The udevinfo attribute walk (-a) now works with giving a device node
678 name (-n) instead of a devpath (-p). The query now always works, also when
679 no database file was created by udev.
681 The built-in /etc/passwd /etc/group parser is removed, we always depend on
682 getpwnam() and getgrnam() now. One of the next releases will depend on
683 fnmatch() and may use getopt_long().
687 Bugfixes and small improvements.
691 Fix path_id for recent kernels.
697 Added support for swapping network interface names, by temporarily
698 renaming the device and wait for the target name to become free.
702 The built-in MODALIAS key and substitution is removed.
706 The binary firmware helper is replaced by the usual simple
707 shell script. Udevsend is removed from the tree.
715 Some more keys require the correct use of '==' and '=' depending
716 on the kind of operation beeing an assignment or a match. Rules
717 with invalid operations are skipped and logged to syslog. Please
718 test with udevtest if the parsing of your rules throws errors and
719 fix possibly broken rules.
723 Provide "udevsettle" to wait for all current udev events to finish.
724 It also watches the current kernel netlink queue by comparing the
725 even sequence number to make sure that there are no current pending
726 events that have not already arrived in the daemon.
730 Fix rule to skip persistent rules for removable IDE devices, which
731 also skipped optical IDE drives.
733 All *_id program are installed in /lib/udev/ by default now.
735 No binary is stripped anymore as this should be done in the
736 packaging process and not at build time.
738 libvolume_id is provided as a shared library now and vol_id is
739 linked against it. Also one of the next HAL versions will require
740 this library, and the HAL build process will also require the
741 header file to be installed. The copy of the same code in HAL will
742 be removed to have only a single copy left on the system.
746 Add persistent links for SCSI tapes. The rules file is renamed
747 to 60-persistent-storage.rules.
749 Create persistent path for usb devices. Can be used for all sorts
750 of devices that can't be distinguished by other properties like
751 multiple identical keyboards and mice connected to the same box.
753 Provide "udevtrigger" program to request events on coldplug. The
754 shell script is much too slow with thousends of devices.
758 Fix persistent disk rules to exclude removable IDE drives.
760 Warn if %e, $modalias or MODALIAS is used.
764 Fix queue export, which wasn't correct for subsequent add/remove
765 events for the same device.
769 Fix cramfs detection on big endian.
771 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
776 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
777 attributes were only checked at the parent device that matched the
778 by BUS requested subsystem. Fix it to also look at the device we
779 received the event for.
781 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
786 Fix a bug where NAME="" would prevent RUN from beeing executed.
788 RUN="/bin/program" does not longer automatically add the subsystem
789 as the first parameter. This is from the days of /sbin/hotplug
790 which is dead now and it's just confusing to need to add a space at
791 the end of the program name to prevent this.
792 If you use rules that need the subsystem as the first parameter,
793 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
794 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
798 The udev man page has moved to udev(7) as it does not describe a command
799 anymore. The programs udev, udevstart and udevsend are no longer installed
800 by default and must be copied manually, if they should be installed or
801 included in a package.
803 Fix a bug where "ignore_device" could run earlier collected RUN keys before
804 the ignore rule was applied.
806 More preparation for future sysfs changes. usb_id and scsi_id no longer
807 depend on a magic order of devices in the /devices chain. Specific devices
808 should be requested by their subsytem.
810 This will always find the scsi parent device without depending on a specific
812 dev = sysfs_device_get(devpath);
813 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
815 The "device" link in the current sysfs layout will be automatically
816 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
817 parent in the devpath. If a device is requested by it's symlink, like all
818 class devices in the new sysfs layout will look like, it gets automatically
819 resolved and substituted with the real devpath and not the symlink path.
822 A similar logic must be applied to _all_ sysfs users, including
823 scripts, that search along parent devices in sysfs. The explicit use of
824 the "device" link must be avoided. With the future sysfs layout all
825 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
826 back to the "class" or the "bus". The layout of the parent devices in
827 /devices is not necessarily expected to be stable across kernel releases and
828 searching for parents by their subsystem should make sysfs users tolerant
829 for changed parent chains.
833 Prepare udev to work with the experimental kernel patch, that moves
834 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
836 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
837 moving the class devices to /sys/devices.
839 Thanks again to Marco for help finding a hopefully nice compromise
840 to make %b simpler and working again.
844 Complete removal of libsysfs, replaced by simple helper functions
845 which are much simpler and a bit faster. The udev daemon operatesentirely
846 on event parameters and does not use sysfs for simple rules anymore.
847 Please report any new bugs/problems, that may be caused by this big
848 change. They will be fixed immediately.
850 The enumeration format character '%e' is deprecated and will be
851 removed sometimes from a future udev version. It never worked correctly
852 outside of udevstart, so we can't use it with the new parallel
853 coldplug. A simple enumeration is as useless as the devfs naming
854 scheme, just get rid of both if you still use it.
856 MODALIAS and $modalias is not needed and will be removed from one of
857 the next udev versions, replace it in all rules with ENV{MODALIAS} or
858 the sysfs "modalias" value.
860 Thanks a lot to Marco for all his help on finding and fixing bugs.
864 Let scsi_id request libata drive serial numbers from page 0x80.
866 Renamed etc/udev/persistent.rules to persistent-disk.rules and
867 added /dev/disk/by-name/* for device mapper device names.
869 Removed %e from the man page. It never worked reliably outside
870 of udevstart and udevstart is no longer recommended to use.
874 Symlinks are now exported to the event environment. Hopefully it's no
875 longer needed to run udevinfo from an event process, like it was
876 mentioned on the hotplug list:
877 UDEV [1134776873.702967] add@/block/sdb
880 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
884 Fix a problem if udevsend is used as the hotplug handler and tries to use
885 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
886 and this kind of problems will hopefully go away soon.
890 All built-in logic to work around bad sysfs timing is removed with this
891 version. The need to wait for sysfs files is almost fixed with a kernel
892 version that doesn't work with this udev version anyway. Until we fix
893 the timing of the "bus" link creation, the former integrated logic should
894 be emulated by a rule placed before all other rules:
895 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
897 The option "udev_db" does no longer exist. All udev state will be in
898 /$udev_root/.udev/ now, there is no longer an option to set this
900 If the init script or something else used this value, just depend on
901 this hardcoded path. But remember _all_content_ of this directory is
902 still private to udev and can change at any time.
904 Default location for rule sripts and helper programs is now: /lib/udev/.
905 Everything that is not useful on the commandline should go into this
906 directory. Some of the helpers in the extras folder are installed there
907 now. The rules need to be changed, to find the helpers there.
909 Also /lib/udev/devices is recommended as a directory where packages or
910 the user can place real device nodes, which get copied over to /dev at
911 every boot. This should replace the various solutions with custom config
914 Udevsend does no longer start the udev daemon. This must be done with
915 the init script that prepares /dev on tmpfs and creates the initial nodes,
916 before starting the daemon.
920 Silent a too verbose error logging for the old hotplug.d/ dev.d/
923 The copy of klibc is removed. A systemwide installed version of klibc
924 should be used to build a klibc udev now.
928 NAME="" will not create any nodes, but execute RUN keys. To completely
929 ignore an event the OPTION "ignore_device" should be used.
931 After removal of the reorder queue, events with a TIMEOUT can be executed
932 without any queuing now.
936 Fixed bug in udevd, if inotify is not available. We depend on netlink
937 uevents now, kernels without that event source will not work with that
938 version of udev anymore.
942 The rule parsing happens now in the daemon once at startup, all udev
943 event processes inherit the already parsed rules from the daemon.
944 It is shipped with SUSE10.0 and reduces heavily the system load at
945 startup. The option to save precompiled rules and let the udev process
946 pick the them up is removed, as it's no longer needed.
948 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
949 device. Libsysfs is changed to "translate" the requested link into the
950 real device path, as it would happen with the hotplug event. Otherwise
951 device removal and the udev database will not work.
953 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
956 A few improvements for vol_id, the filesytem probing code.
960 Fix a stupid typo in extras/run_directory for "make install".
962 scsi_id creates the temporary devnode now in /dev for usage with a
963 non-writable /tmp directory.
965 The uevent kernel socket buffer can carry app. 50.000 events now,
966 let's see who can break this again. :)
968 The upcoming kernel will have a new input driver core integration.
969 Some class devices are now symlinks to the real device. libsysfs
970 needs a fix for this to work correctly. Udevstart of older udev
971 versions will _not_ create these devices!
975 Fix a 'install' target in the Makefile, that prevents EXTRAS from
980 A bunch of mostly trivial bugfixes. From now on no node name or
981 symlink name can contain any character than plain whitelisted ascii
982 characters or validated utf8 byte-streams. This is needed for the
983 /dev/disk/by-label/* links, because we import untrusted data and
984 export it to the filesystem.
988 More bugfixes. If udevd was started from the kernel, we don't
989 have stdin/stdout/stderr, which broke the forked tools in some
994 Bugfix. udevstart event ordering was broken for a long time.
995 The new run_program() uncovered it, because /dev/null was not
996 available while we try to run external programs.
997 Now udevstart should create it before we run anything.
1001 Minor bugfixes and some distro rules updates. If you don't have the
1002 persistent disk rules in /dev/disk/by-*/* on your distro, just
1003 grab it from here. :)
1007 We can use socket communication now to pass events from udev to
1009 RUN+="socket:/org/freedesktop/hal/udev_event"
1010 will pass the whole udev event to the HAL daemon without the need
1011 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1015 Mostly bugfixes and see ChangeLog.
1017 The test for the existence of an environment value should be
1019 ENV{KEY}=="*" to ENV{KEY}=="?*"
1020 because "*" will not fail anymore, if the key does not exist or
1025 Bugfixes and a few tweaks described in the ChangeLog.
1029 Mostly a Bugfix release.
1031 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1032 timing with custom rules.
1036 We changed the internal rule storage format. Our large rule files took
1037 2 MB of RAM, with the change we are down to 99kB.
1039 If the device-node has been created with default name and no symlink or
1040 options are to remenber, it is not longer stored in the udevdb. HAL will
1041 need to be updated to work correctly with that change.
1043 To overrride optimization flags, OPTFLAGS may be used now.
1051 Major changes happened with this release. The goal is to take over the
1052 complete kernel-event handling and provide a more efficient way to dispatch
1053 kernel events. Replacing most of the current shell script logic and the
1054 kernel forked helper with a netlink-daemon and a rule-based event handling.
1056 o udevd listens to netlink events now. The first valid netlink event
1057 will make udevd ignore any message from udevsend that contains a
1058 SEQNUM, to avoid duplicate events. The forked events can be disabled
1060 echo "" > /proc/sys/kernel/hotplug
1061 For full support, the broken input-subsytem needs to be fixed, not to
1062 bypass the driver core.
1064 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1065 removed from udev itself and must be emulated by calling small
1066 helper binaries provided in the extras folder:
1067 make EXTRAS=extras/run_directory/
1068 will build udev_run_devd and udev_run_hotplugd, which can be called
1069 from a rule if needed:
1070 RUN+="/sbin/udev_run_hotplugd"
1071 The recommended way to handle this is to convert all the calls from
1072 the directories to explicit udev rules and get completely rid of the
1073 multiplexing. (To catch a ttyUSB event, you now no longer need to
1074 fork and exit 300 tty script instances you are not interested in, it
1075 is just one rule that matches exactly the device.)
1077 o udev handles now _all_ events not just events for class and block
1078 devices, this way it is possible to control the complete event
1079 behavior with udev rules. Especially useful for rules like:
1080 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1082 o As used in the modalias rule, udev supports now textual
1083 substitution placeholder along with the usual format chars. This
1084 needs to be documented, for now it's only visible in udev_rules_parse.c.
1086 o The rule keys support now more operations. This is documented in the
1087 man page. It is possible to add values to list-keys like the SYMLINK
1088 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1089 Also "final"-assignments are supported by using KEY:="value", which will
1090 prevent changing the key by any later rule.
1092 o kernel 2.6.12 has the "detached_state" attribute removed from
1093 sysfs, which was used to recognize sysfs population. We switched that
1094 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1095 Running this udev version on older kernels may cause a short delay for
1098 o To provide infrastructure for persistent device naming, the id programs:
1099 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1100 to export the probed data in environment key format:
1101 pim:~ # /sbin/ata_id --export /dev/hda
1102 ID_MODEL=HTS726060M9AT00
1103 ID_SERIAL=MRH401M4G6UM9B
1104 ID_REVISION=MH4OA6BA
1106 The following rules:
1107 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1108 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1111 kay@pim:~> tree /dev/disk
1114 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1115 | `-- IBM-Memory_Key -> ../../sda
1117 | |-- swap -> ../../hda1
1118 | |-- date -> ../../sda1
1119 | `-- home -> ../../hda3
1121 |-- 2E08712B0870F2E7 -> ../../hda3
1122 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1123 |-- E845-7A89 -> ../../sda1
1124 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1126 The IMPORT= operation will import these keys in the environment and make
1127 it available for later PROGRAM= and RUN= executed programs. The keys are
1128 also stored in the udevdb and can be queried from there with one of the
1131 o A few binaries are silently added to the repository, which can be used
1132 to replay kernel events from initramfs instead of using coldplug. udevd
1133 can be instructed now to queue-up events while the stored events from
1134 initramfs are filled into the udevd-queue. This code is still under
1135 development and there is no documentation now besides the code itself.
1136 The additional binaries get compiled, but are not installed by default.
1138 o There is also a temporary fix for a performance problem where too many
1139 events happen in parallel and every event needs to parse the rules.
1140 udev can now read precompiled rules stored on disk. This is likely to be
1141 replaced by a more elegant solution in a future udev version.
1145 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1146 Fix for libsysfs not to expect this file was added.
1150 All rules are applied now, but only the first matching rule with a NAME-key
1151 will be applied. All later rules with NAME-key are completely ignored. This
1152 way system supplied symlinks or permissions gets applied to user-defined
1156 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1157 to some rules, to keep the old behavior.
1159 The rules are read on "remove"-events too. That makes is possible to match
1160 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1161 instruct udev to ignore an event (OPTIONS="ignore_device").
1162 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1164 The new RUN-key supports rule-based execution of programs after device-node
1165 handling. This is meant as a general replacement for the dev.d/-directories
1166 to give fine grained control over the execution of programs.
1168 The %s{}-sysfs format char replacement values are searched at any of the
1169 devices in the device chain now, not only at the class-device.
1171 We support log priority levels now. The value udev_log in udev.conf is used
1172 to determine what is printed to syslog. This makes it possible to
1173 run a version with compiled-in debug messages in a production environment
1174 which is sometimes needed to find a bug.
1175 It is still possible to supress the inclusion of _any_ syslog usage with
1176 USE_LOG=false to create the smallest possible binaries if needed.
1177 The configured udev_log value can be overridden with the environment variable
1182 Possible use of a system-wide klibc:
1183 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1184 will link against an external klibc and our own version will be ignored.
1188 We support an unlimited count of symlinks now.
1190 If USE_STATIC=true is passed to a glibc build, we link statically and use
1191 a built-in userdb parser to resolve user and group names.
1193 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1194 we walk up the chain of physical devices to find a match.
1196 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1197 easy to skip certain attribute matches without composing rules with weird
1198 character class negations like:
1199 KERNEL="[!s][!c][!d]*"
1200 this can now be replaced with:
1202 The current simple '=' is still supported, and should work as it does today,
1203 but existing rules should be converted if possible, to be better readable.
1205 We have new ENV{}== key now, to match against a maximum of 5 environment
1208 udevstart is its own binary again, because we don't need co carry this araound
1209 with every forked event.