5 To support DEVPATH strings larger than the maximum file name length, the
6 private udev database format has changed. If some software still reads the
7 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
8 Please do not port anything to the new format again, everything in /dev/.udev
9 is and always was private to udev, and may and will change any time without
12 Multiple devices claiming the same names in /dev are limited to symlinks
13 only now. Mixing identical symlink names and node names is not supported.
14 This reduces the amount of data in the database significantly.
16 NAME="%k" causes a warning now. It's is and always was completely superfluous.
17 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
20 Symlinks to udevadm with the old command names are no longer resolved to
27 The udevadm trigger "--retry-failed" option, which is replaced since quite
28 a while by "--type=failed" is removed.
30 The failed tracking was not working at all for a few releases. The RUN
31 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
32 default is not to track any failing RUN executions.
34 New keymaps, new modem, hid2hci updated.
38 Fix possible crash in udevd when worker processes are busy, rules are
39 changed at the same time, and workers get killed to reload the rules.
45 Properties set with ENV{.FOO}="bar" are marked private by starting the
46 name with a '.'. They will not be stored in the database, and not be
47 exported with the event.
49 Firmware files are looked up in:
50 /lib/firmware/updates/$(uname -r)
52 /lib/firmware/$(uname -r)
56 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
57 ata_id, instead of scsi_id, is the default tool now for ATA devices.
63 The configure options have changed because another library needs to be
64 installed in a different location. Instead of exec_prefix and udev_prefix,
65 libdir, rootlibdir and libexecdir are used. The Details are explained in
68 Event processes now get re-used after they handled an event. This reduces
69 the number of forks and the pressure on the CPU significantly, because
70 cloned event processes no longer cause page faults in the main daemon.
71 After the events have settled, a few worker processes stay around for
72 future events, all others get cleaned up.
74 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
75 Also inotify support is mandatory now to run udev.
77 The format of the queue exported by the udev damon has changed. There is
78 no longer a /dev/.udev/queue/ directory. The current event queue can be
79 accessed with udevadm settle and libudedv.
81 Libudev does not have the unstable API header anymore. From now on,
82 incompatible changes will be handled by bumping the library major version.
84 To build udev from the git tree gtk-doc is needed now. The tarballs will
85 build without it and contain the pre-built documentation. An online copy
87 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
89 The tools from the udev-extras repository have been merged into the main
90 udev repository. Some of the extras have larger external dependencies, and
91 they can be disabled with the configure switch --disable-extras.
97 The program vol_id and the library libvolume_id are removed from the
98 repository. Libvolume_id is merged with libblkid from the util-linux-ng
99 package. Persistent disk links for label and uuid depend on the
100 util-linux-ng version (2.15) of blkid now. Older versions of blkid
101 can not be used with udev.
103 Libudev allows to subscribe to udev events. To prevent unwanted messages
104 to be delivered, and waking up the subscribing process, a filter can be
105 installed, to drop messages inside a kernel socket filter. The filters
106 match on the <subsytem>:<devtype> properties of the device.
107 This is part of the ongoing effort to replace HAL, and switch current
108 users over to directly use libudev.
109 Libudev is still marked as experimental, and its interface might
110 eventually change if needed, but no major changes of the currently exported
111 interface are expected anymore, and a first stable release should happen
114 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
115 is not supported since while and udevd will log an error message at
116 startup. It should still be able to boot-up, but advanced rules and system
117 services which depend on the information not available in the old sysfs
118 format will fail to work correctly.
120 DVB device naming is supplied by the kernel now. In case older kernels
121 need to be supported, the old shell script should be added to a compat
128 The processed udev events get send back to the netlink socket. Libudev
129 provides access to these events. This is work-in-progress, to replace
130 the DeviceKit daemon functionality directly with libudev. There are
131 upcoming kernel changes to allow non-root users to subcribe to these
138 "udevadm settle" now optionally accepts a range of events to wait for,
139 instead of waiting for "all" events.
145 The installed watch for block device metadata changes is now removed
146 during event hadling, because some (broken) tools may be called from udev
147 rules and (wrongly) open the device with write access. After the finished
148 event handling the watch is restored.
154 Device nodes can be watched for changes with inotify with OPTIONS="watch".
155 If closed after being opened for writing, a "change" uevent will occur.
156 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
162 The udevadm test command has no longer a --force option, nodes and symlinks
163 are always updated with a test run now.
165 The udevd daemon can be started with --resolve-names=never to avoid all user
166 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
167 lookup user and groups every time events are handled.
173 We are currently merging the Ubuntu rules in the udev default rules,
174 and get one step closer to provide a common Linux /dev setup, regarding
175 device names, symlinks, and default device permissions. On udev startup,
176 we now expect the following groups to be resolvable to their ids with
178 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
179 LDAP setups need to make sure, that these groups are always resolvable at
180 bootup, with only the rootfs mounted, and without network access available.
182 Some systems may need to add some new, currently not used groups, or need
183 to add some users to new groups, but the cost of this change is minimal,
184 compared to the pain the current, rather random, differences between the
185 various distributions cause for upstream projects and third-party vendors.
187 In general, "normal" users who log into a machine should never be a member
188 of any such group, but the device-access should be managed by dynamic ACLs,
189 which get added and removed for the specific users on login/logout and
190 session activity/inactivity. These groups are only provided for custom setups,
191 and mainly system services, to allow proper privilege separation.
192 A video-streaming daemon uid would be a member of "audio" and "video", to get
193 access to the sound and video devices, but no "normal" user should ever belong
194 to the "audio" group, because he could listen to the built-in microphone with
195 any ssh-session established from the other side of the world.
197 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
198 which do not depend on the kernel device name. As usual, unique
199 devices - only a single one per product connected, or a real
200 USB serial number in the device - are always found with the same
201 name in the by-id/ directory.
202 Completely identical devices may overwrite their names in by-id/
203 and can only be found reliably in the by-path/ directory. Devices
204 specified by by-path/ must not change their connection, like the
205 USB port number they are plugged in, to keep their name.
207 To support some advanced features, Linux 2.6.22 is the oldest supported
208 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
209 supported. Older kernels should still work, and devices nodes should be
210 reliably created, but some rules and libudev will not work correctly because
211 the old kernels do not provide the expected information or interfaces.
217 Fix for a possible segfault while swapping network interface names in udev
224 The group "video" is part of the default rules now.
228 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
229 block devices in some cases. No common distro uses this option anymore,
230 and we do not get enough testing for this and recent udev versions. If
231 this option is not needed to run some old distro with a new kernel,
232 it should be disabled in the kernel config.
234 Bugfix for the $links substitution variable, which may crash if no links
235 are created. This should not happen in usual setups because we always
236 create /dev/{block,char}/ links.
238 The strings of the parsed rules, which are kept in memory, no longer
239 contain duplicate entries, or duplicate tails of strings. This, and the
240 new rules parsing/matching code reduces the total in-memory size of
241 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
244 The export of DEVTYPE=disk/partition got removed from the default
245 rules. This value is available from the kernel. The pnp shell script
246 modprobe hack is removed from the default rules. ACPI devices have _proper_
247 modalias support and take care of the same functionality.
248 Installations which support old kernels, but install current default
249 udev rules may want to add that to the compat rules file.
251 Libvolume_id now always probes for all known filesystems, and does not
252 stop at the first match. Some filesystems are marked as "exclusive probe",
253 and if any other filesytem type matches at the same time, libvolume_id
254 will, by default, not return any probing result. This is intended to prevent
255 mis-detection with conflicting left-over signatures found from earlier
256 file system formats. That way, we no longer depend on the probe-order
257 in case of multiple competing signatures. In some setups the kernel allows
258 to mount a volume with just the old filesystem signature still in place.
259 This may damage the new filesystem and cause data-loss, just by mounting
260 it. Because volume_id can not decide which one the correct signature is,
261 the wrong signatures need to be removed manually from the volume, or the
262 volume needs to be reformatted, to enable filesystem detection and possible
267 Fix segfault if compiled without optimization and dbg() does not get
268 compiled out and uses variables which are not available.
272 Bugfixes. (And maybe new bugs. :))
274 The rule matching engine got converted from a rule list to a token
275 array which reduced the in-memory rules representation of a full
276 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
277 Limits like 5 ENV and ATTR matches, and one single instance for most
278 other keys per rule are gone.
280 The NAME assignment is no longer special cased. If later rules assign
281 a NAME value again, the former value will be overwritten. As usual
282 for most other keys, the NAME value can be protected by doing a final
283 assignment with NAME:="<value>".
285 All udev code now uses libudev, which is also exported. The library
286 is still under development, marked as experimental, and its interface
287 may change as long as the DeviceKit integration is not finished.
289 Many thanks to Alan Jenkins for his continuous help, and finding and
290 optimizing some of the computing expensive parts.
296 Kernel devices and device nodes are connected now by reverse indizes in
297 /sys and /dev. A device number retrieved by a stat() or similar, the
298 kernel device directory can be found by looking up:
299 /sys/dev/{block,char}/<maj>:<min>
300 and the device node of the same device by looking up:
301 /dev/{block,char}/<maj>:<min>
305 Fix recently introduced bug, which caused a compilation without large
306 file support, where vol_id does not recognize raid signatures at the end
309 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
310 Seems some kernel versions prevent the creation of the ieee-* links,
311 so people used the scsi-* link which disappeared now.
313 More libudev work. Almost all udevadm functionality comes from libudev
316 udevadm trigger has a new option --type, which allows to trigger events
317 for "devices", for "subsystems", or "failed" devices. The old option
318 --retry-failed" still works, but is no longer mentioned in the man page.
324 The udevadm info --device-id-of-file= output has changed to use
325 the obvious format. Possible current users should use the --export
326 option which is not affected.
328 The old udev commands symlinks to udevadm are not installed, if
329 these symlinks are used, a warning is printed.
335 Optical drive's media is no longer probed for raid signatures,
336 reading the end of the device causes some devices to malfunction.
337 Also the offset of the last session found is used now to probe
340 The volume_id library got a major version number update to 1,
341 some deprecated functions are removed.
343 A shared library "libudev" gets installed now to provide access
344 to udev device information. DeviceKit, the successor of HAL, will
345 need this library to access the udev database and search sysfs for
347 The library is currently in an experimental state, also the API is
348 expected to change, as long as the DeviceKit integration is not
353 We use ./configure now. See INSTALL for details. Current
356 "/usr" - prefix for man pages, include files
358 "" - the root filesystem, prefix for libs and binaries
362 "lib" - directory name for libraries, not a path name
363 multilib 64bit systems may use "lib64" instead of "lib"
365 compile-in verbose debug messages
367 disable all logging and compile-out all log strings
369 link against SELInux libraries, to set the expected context
372 In the default rules, the group "disk" gets permissions 0660 instead
373 of 0640. One small step closer to unify distro rules. Some day, all
374 distros hopefully end up with the same set of rules.
376 No symlinks to udevadm are installed anymore, if they are still needed,
377 they should be provided by the package.
383 Default udev rules, which are not supposed to be edited by the user, should
384 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
385 the udev package and will be replaced with an update. Udev will pick up rule
387 /lib/udev/rules.d/ - default installed rules
388 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
389 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
390 It does not matter in which directory a rule file lives, all files are sorted
393 To help creating /dev/root, we have now:
394 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
397 In case the current --device-id-of-file is already used, please switch to
398 the --export format version, it saves the output parsing and the old
399 format will be changed to use ':' as a separator, like the format in the
404 Fix cdrom_id to properly recognize blank media.
410 Tape drive id-data is queried from /dev/bsg/* instead of the tape
411 nodes. This avoids rewinding tapes on open().
417 The symlinks udevcontrol and udevtrigger are no longer installed by
420 The scsi_id program does not depend on sysfs anymore. It can speak
421 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
422 data, which should solve some old problems with tape devices, where
423 we better do not open all tape device nodes to identify the device.
429 The cdrom_id program is replaced by an advanced version, which can
430 detect most common device types, and also properties of the inserted
431 media. This is part of moving some basic functionality from HAL into
432 udev (and the kernel).
438 The last WAIT_FOR_SYSFS rule is removed from the default rules.
440 The symlinks to udevadm for the debugging tools: udevmonitor and
441 udevtest are no longer created.
443 The symlinks to the udevadm man page for the old tool names are
446 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
447 should be prefixed with '@' to indicate that the path is not a
458 Udevstart is removed from the tree, it did not get installed for
459 a long time now, and is long replaced by trigger and settle.
465 All udev tools are merged into a single binary called udevadm.
466 The old names of the tools are built-in commands in udevadm now.
467 Symlinks to udevadm, with the names of the old tools, provide
468 the same functionality as the standalone tools. There is also
469 only a single udevadm.8 man page left for all tools.
471 Tools like mkinitramfs should be checked, if they need to include
472 udevadm in the list of files.
482 The etc/udev/rules.d/ directory now contains a default set of basic
483 udev rules. This initial version is the result of a rules file merge
484 of Fedora and openSUSE. For these both distros only a few specific
485 rules are left in their own file, named after the distro. Rules which
486 are optionally installed, because they are only valid for a specific
487 architecture, or rules for subsystems which are not always used are
488 in etc/udev/packages/.
494 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
495 actions by dynamically created rules.
497 SYMLINK=="<value>" matches agains the entries in the list of
498 currently defined symlinks. The links are not created in the
499 filesystem at that point in time, but the values can be matched.
501 RUN{ignore_error}+="<program>" will ignore any exit code from the
502 program and not record as a failed event.
508 Final merge of patches/features from the Ubuntu package.
514 Control characters in filesystem label strings are no longer silenty
515 removed, but hex-encoded, to be able to uniquely identify the device
516 by its symlink in /dev/disk/by-label/.
517 If libvolume_id is used by mount(8), LABEL= will work as expected,
518 if slashes or other characters are used in the label string.
520 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
521 can be specified now. The TEST key accepts an optional mode mask
522 TEST{0100}=="<is executable file>".
524 Scsi_id now supports a mode without expecting scsi-specific sysfs
525 entries to allow the extraction of cciss-device persistent properties.
531 In the future, we may see uuid's which are just simple character
532 strings (see the DDF Raid Specification). For that reason vol_id now
533 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
534 the creation of symlinks, the *_SAFE values ensure, that no control
535 or whitespace characters are used in the filename.
537 Possible users of libvolume_id, please use the volume_id_get_* functions.
538 The public struct will go away in a future release of the library.
544 Removal of useless extras/eventrecorder.sh.
554 The directory multiplexer for dev.d/ and hotplug.d are finally removed
555 from the udev package.
561 Symlinks can have priorities now, the priority is assigned to the device
562 and specified with OPTIONS="link_priority=100". Devices with higher
563 priorities overwrite the symlinks of devices with lower priorities.
564 If the device that currently owns the link, goes away, the symlink
565 will be removed, and recreated, pointing to the next device with the
566 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
567 more reliable, if multiple devices contain the same metadata and overwrite
570 The dasd_id program is removed from the udev tree, and dasdinfo, with the
571 needed rules, are part of the s390-tools now.
573 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
574 we may get the scsi sysfs mess fixed some day, and this will only catch
575 the devices we are looking for.
577 USB serial numbers for storage devices have the target:lun now appended,
578 to make it possibble to distinguish broken multi-lun devices with all
579 the same SCSI identifiers.
581 Note: The extra "run_directory" which searches and executes stuff in
582 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
583 with the next release. Make sure, that you don't use it anymore, or
584 provides your own implementation of that inefficient stuff.
585 We are tired of reports about a "slow udev", because these directories
586 contain stuff, that runs with _every_ event, instead of using rules,
587 that run programs only for the matching events.
597 DRIVER== will match only for devices that actually have a real
598 driver. DRIVERS== must be used, if parent devices should be
599 included in the match.
601 Libvolume_id's "linux_raid" detection needed another fix.
609 Add additional check to volume_id detection of via_raid, cause
610 some company decided to put a matching pattern all over the empty
611 storage area of their music players.
615 Fix path_id for SAS devices.
619 The udev daemon can be started with --debug-trace now, which will
620 execute all events serialized to get a chance to catch a possible
621 action that crashes the box.
623 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
624 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
625 are excluded from the warning. Referencing parent attributes directly
626 may break when something in the kernel driver model changes. Udev will
627 just find the attribute by walking up the parent chain.
629 Udevtrigger now sorts the list of devices depending on the device
630 dependency, so a "usb" device is triggered after the parent "pci"
635 Revert persistent-storage ata-serial '_' '-' replacement.
641 Udevtrigger can now filter the list of devices to be triggered. Matches
642 for subsystems or sysfs attributes can be specified.
644 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
645 zero-sized files to avoid pointing to /sys and confuse broken tools which
646 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
649 The rules and scripts to create udev rules for persistent network
650 devices and optical drives are in the extras/rules_generator directory
651 now. If you use something similar, please consider replacing your own
652 version with this, to share the support effort. The rule_generator
653 installs its own rules into /etc/udev/rules.d.
655 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
656 the rule_generator depends on cdrom_id to be called in an earlier rule.
662 Renaming of some key names (the old names still work):
663 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
664 (The behavior of the key DRIVER will change soon in one of the next
665 releases, to match only the event device, please switch to DRIVERS
666 instead. If DRIVER is used, it will behave like DRIVERS, but an error
668 With the new key names, we have a more consistent and simpler scheme.
669 We can match the properties of the event device only, with: KERNEL,
670 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
671 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
672 longer mentioned in the man page and should be switched in the rule
675 ATTR{file}="value" can be used now, to write to a sysfs file of the
676 event device. Instead of:
677 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
679 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
681 All the PHYSDEV* keys are deprecated and will be removed from a
683 PHYDEVPATH - is the path of a parent device and should not be
685 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
686 matched with SUBSYSTEMS==
687 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
688 Newer kernels will have DRIVER in the environment,
689 for older kernels udev puts in. Class device will
690 no longer carry this property of a parent and
691 DRIVERS== can be used to match such a parent value.
692 Note that ENV{DRIVER} is only available for a few bus devices, where
693 the driver is already bound at device event time. On coldplug, the
694 events for a lot devices are already bound to a driver, and they will have
695 that value set. But on hotplug, at the time the kernel creates the device,
696 it can't know what driver may claim the device after that, therefore
697 in most cases it will be empty.
699 Failed events should now be re-triggered with:
700 udevtrigger --retry-failed.
701 Please switch to this command, so we keep the details of the /dev/.udev/failed/
702 files private to the udev tools. We may need to switch the current symlink
703 target, cause some obviously broken tools try to scan all files in /dev
704 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
705 million times. This takes ages on slow boxes.
707 The udevinfo attribute walk (-a) now works with giving a device node
708 name (-n) instead of a devpath (-p). The query now always works, also when
709 no database file was created by udev.
711 The built-in /etc/passwd /etc/group parser is removed, we always depend on
712 getpwnam() and getgrnam() now. One of the next releases will depend on
713 fnmatch() and may use getopt_long().
717 Bugfixes and small improvements.
721 Fix path_id for recent kernels.
727 Added support for swapping network interface names, by temporarily
728 renaming the device and wait for the target name to become free.
732 The built-in MODALIAS key and substitution is removed.
736 The binary firmware helper is replaced by the usual simple
737 shell script. Udevsend is removed from the tree.
745 Some more keys require the correct use of '==' and '=' depending
746 on the kind of operation beeing an assignment or a match. Rules
747 with invalid operations are skipped and logged to syslog. Please
748 test with udevtest if the parsing of your rules throws errors and
749 fix possibly broken rules.
753 Provide "udevsettle" to wait for all current udev events to finish.
754 It also watches the current kernel netlink queue by comparing the
755 even sequence number to make sure that there are no current pending
756 events that have not already arrived in the daemon.
760 Fix rule to skip persistent rules for removable IDE devices, which
761 also skipped optical IDE drives.
763 All *_id program are installed in /lib/udev/ by default now.
765 No binary is stripped anymore as this should be done in the
766 packaging process and not at build time.
768 libvolume_id is provided as a shared library now and vol_id is
769 linked against it. Also one of the next HAL versions will require
770 this library, and the HAL build process will also require the
771 header file to be installed. The copy of the same code in HAL will
772 be removed to have only a single copy left on the system.
776 Add persistent links for SCSI tapes. The rules file is renamed
777 to 60-persistent-storage.rules.
779 Create persistent path for usb devices. Can be used for all sorts
780 of devices that can't be distinguished by other properties like
781 multiple identical keyboards and mice connected to the same box.
783 Provide "udevtrigger" program to request events on coldplug. The
784 shell script is much too slow with thousends of devices.
788 Fix persistent disk rules to exclude removable IDE drives.
790 Warn if %e, $modalias or MODALIAS is used.
794 Fix queue export, which wasn't correct for subsequent add/remove
795 events for the same device.
799 Fix cramfs detection on big endian.
801 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
806 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
807 attributes were only checked at the parent device that matched the
808 by BUS requested subsystem. Fix it to also look at the device we
809 received the event for.
811 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
816 Fix a bug where NAME="" would prevent RUN from beeing executed.
818 RUN="/bin/program" does not longer automatically add the subsystem
819 as the first parameter. This is from the days of /sbin/hotplug
820 which is dead now and it's just confusing to need to add a space at
821 the end of the program name to prevent this.
822 If you use rules that need the subsystem as the first parameter,
823 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
824 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
828 The udev man page has moved to udev(7) as it does not describe a command
829 anymore. The programs udev, udevstart and udevsend are no longer installed
830 by default and must be copied manually, if they should be installed or
831 included in a package.
833 Fix a bug where "ignore_device" could run earlier collected RUN keys before
834 the ignore rule was applied.
836 More preparation for future sysfs changes. usb_id and scsi_id no longer
837 depend on a magic order of devices in the /devices chain. Specific devices
838 should be requested by their subsytem.
840 This will always find the scsi parent device without depending on a specific
842 dev = sysfs_device_get(devpath);
843 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
845 The "device" link in the current sysfs layout will be automatically
846 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
847 parent in the devpath. If a device is requested by it's symlink, like all
848 class devices in the new sysfs layout will look like, it gets automatically
849 resolved and substituted with the real devpath and not the symlink path.
852 A similar logic must be applied to _all_ sysfs users, including
853 scripts, that search along parent devices in sysfs. The explicit use of
854 the "device" link must be avoided. With the future sysfs layout all
855 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
856 back to the "class" or the "bus". The layout of the parent devices in
857 /devices is not necessarily expected to be stable across kernel releases and
858 searching for parents by their subsystem should make sysfs users tolerant
859 for changed parent chains.
863 Prepare udev to work with the experimental kernel patch, that moves
864 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
866 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
867 moving the class devices to /sys/devices.
869 Thanks again to Marco for help finding a hopefully nice compromise
870 to make %b simpler and working again.
874 Complete removal of libsysfs, replaced by simple helper functions
875 which are much simpler and a bit faster. The udev daemon operatesentirely
876 on event parameters and does not use sysfs for simple rules anymore.
877 Please report any new bugs/problems, that may be caused by this big
878 change. They will be fixed immediately.
880 The enumeration format character '%e' is deprecated and will be
881 removed sometimes from a future udev version. It never worked correctly
882 outside of udevstart, so we can't use it with the new parallel
883 coldplug. A simple enumeration is as useless as the devfs naming
884 scheme, just get rid of both if you still use it.
886 MODALIAS and $modalias is not needed and will be removed from one of
887 the next udev versions, replace it in all rules with ENV{MODALIAS} or
888 the sysfs "modalias" value.
890 Thanks a lot to Marco for all his help on finding and fixing bugs.
894 Let scsi_id request libata drive serial numbers from page 0x80.
896 Renamed etc/udev/persistent.rules to persistent-disk.rules and
897 added /dev/disk/by-name/* for device mapper device names.
899 Removed %e from the man page. It never worked reliably outside
900 of udevstart and udevstart is no longer recommended to use.
904 Symlinks are now exported to the event environment. Hopefully it's no
905 longer needed to run udevinfo from an event process, like it was
906 mentioned on the hotplug list:
907 UDEV [1134776873.702967] add@/block/sdb
910 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
914 Fix a problem if udevsend is used as the hotplug handler and tries to use
915 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
916 and this kind of problems will hopefully go away soon.
920 All built-in logic to work around bad sysfs timing is removed with this
921 version. The need to wait for sysfs files is almost fixed with a kernel
922 version that doesn't work with this udev version anyway. Until we fix
923 the timing of the "bus" link creation, the former integrated logic should
924 be emulated by a rule placed before all other rules:
925 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
927 The option "udev_db" does no longer exist. All udev state will be in
928 /$udev_root/.udev/ now, there is no longer an option to set this
930 If the init script or something else used this value, just depend on
931 this hardcoded path. But remember _all_content_ of this directory is
932 still private to udev and can change at any time.
934 Default location for rule sripts and helper programs is now: /lib/udev/.
935 Everything that is not useful on the commandline should go into this
936 directory. Some of the helpers in the extras folder are installed there
937 now. The rules need to be changed, to find the helpers there.
939 Also /lib/udev/devices is recommended as a directory where packages or
940 the user can place real device nodes, which get copied over to /dev at
941 every boot. This should replace the various solutions with custom config
944 Udevsend does no longer start the udev daemon. This must be done with
945 the init script that prepares /dev on tmpfs and creates the initial nodes,
946 before starting the daemon.
950 Silent a too verbose error logging for the old hotplug.d/ dev.d/
953 The copy of klibc is removed. A systemwide installed version of klibc
954 should be used to build a klibc udev now.
958 NAME="" will not create any nodes, but execute RUN keys. To completely
959 ignore an event the OPTION "ignore_device" should be used.
961 After removal of the reorder queue, events with a TIMEOUT can be executed
962 without any queuing now.
966 Fixed bug in udevd, if inotify is not available. We depend on netlink
967 uevents now, kernels without that event source will not work with that
968 version of udev anymore.
972 The rule parsing happens now in the daemon once at startup, all udev
973 event processes inherit the already parsed rules from the daemon.
974 It is shipped with SUSE10.0 and reduces heavily the system load at
975 startup. The option to save precompiled rules and let the udev process
976 pick the them up is removed, as it's no longer needed.
978 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
979 device. Libsysfs is changed to "translate" the requested link into the
980 real device path, as it would happen with the hotplug event. Otherwise
981 device removal and the udev database will not work.
983 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
986 A few improvements for vol_id, the filesytem probing code.
990 Fix a stupid typo in extras/run_directory for "make install".
992 scsi_id creates the temporary devnode now in /dev for usage with a
993 non-writable /tmp directory.
995 The uevent kernel socket buffer can carry app. 50.000 events now,
996 let's see who can break this again. :)
998 The upcoming kernel will have a new input driver core integration.
999 Some class devices are now symlinks to the real device. libsysfs
1000 needs a fix for this to work correctly. Udevstart of older udev
1001 versions will _not_ create these devices!
1005 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1010 A bunch of mostly trivial bugfixes. From now on no node name or
1011 symlink name can contain any character than plain whitelisted ascii
1012 characters or validated utf8 byte-streams. This is needed for the
1013 /dev/disk/by-label/* links, because we import untrusted data and
1014 export it to the filesystem.
1018 More bugfixes. If udevd was started from the kernel, we don't
1019 have stdin/stdout/stderr, which broke the forked tools in some
1024 Bugfix. udevstart event ordering was broken for a long time.
1025 The new run_program() uncovered it, because /dev/null was not
1026 available while we try to run external programs.
1027 Now udevstart should create it before we run anything.
1031 Minor bugfixes and some distro rules updates. If you don't have the
1032 persistent disk rules in /dev/disk/by-*/* on your distro, just
1033 grab it from here. :)
1037 We can use socket communication now to pass events from udev to
1039 RUN+="socket:/org/freedesktop/hal/udev_event"
1040 will pass the whole udev event to the HAL daemon without the need
1041 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1045 Mostly bugfixes and see ChangeLog.
1047 The test for the existence of an environment value should be
1049 ENV{KEY}=="*" to ENV{KEY}=="?*"
1050 because "*" will not fail anymore, if the key does not exist or
1055 Bugfixes and a few tweaks described in the ChangeLog.
1059 Mostly a Bugfix release.
1061 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1062 timing with custom rules.
1066 We changed the internal rule storage format. Our large rule files took
1067 2 MB of RAM, with the change we are down to 99kB.
1069 If the device-node has been created with default name and no symlink or
1070 options are to remenber, it is not longer stored in the udevdb. HAL will
1071 need to be updated to work correctly with that change.
1073 To overrride optimization flags, OPTFLAGS may be used now.
1081 Major changes happened with this release. The goal is to take over the
1082 complete kernel-event handling and provide a more efficient way to dispatch
1083 kernel events. Replacing most of the current shell script logic and the
1084 kernel forked helper with a netlink-daemon and a rule-based event handling.
1086 o udevd listens to netlink events now. The first valid netlink event
1087 will make udevd ignore any message from udevsend that contains a
1088 SEQNUM, to avoid duplicate events. The forked events can be disabled
1090 echo "" > /proc/sys/kernel/hotplug
1091 For full support, the broken input-subsytem needs to be fixed, not to
1092 bypass the driver core.
1094 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1095 removed from udev itself and must be emulated by calling small
1096 helper binaries provided in the extras folder:
1097 make EXTRAS=extras/run_directory/
1098 will build udev_run_devd and udev_run_hotplugd, which can be called
1099 from a rule if needed:
1100 RUN+="/sbin/udev_run_hotplugd"
1101 The recommended way to handle this is to convert all the calls from
1102 the directories to explicit udev rules and get completely rid of the
1103 multiplexing. (To catch a ttyUSB event, you now no longer need to
1104 fork and exit 300 tty script instances you are not interested in, it
1105 is just one rule that matches exactly the device.)
1107 o udev handles now _all_ events not just events for class and block
1108 devices, this way it is possible to control the complete event
1109 behavior with udev rules. Especially useful for rules like:
1110 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1112 o As used in the modalias rule, udev supports now textual
1113 substitution placeholder along with the usual format chars. This
1114 needs to be documented, for now it's only visible in udev_rules_parse.c.
1116 o The rule keys support now more operations. This is documented in the
1117 man page. It is possible to add values to list-keys like the SYMLINK
1118 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1119 Also "final"-assignments are supported by using KEY:="value", which will
1120 prevent changing the key by any later rule.
1122 o kernel 2.6.12 has the "detached_state" attribute removed from
1123 sysfs, which was used to recognize sysfs population. We switched that
1124 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1125 Running this udev version on older kernels may cause a short delay for
1128 o To provide infrastructure for persistent device naming, the id programs:
1129 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1130 to export the probed data in environment key format:
1131 pim:~ # /sbin/ata_id --export /dev/hda
1132 ID_MODEL=HTS726060M9AT00
1133 ID_SERIAL=MRH401M4G6UM9B
1134 ID_REVISION=MH4OA6BA
1136 The following rules:
1137 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1138 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1141 kay@pim:~> tree /dev/disk
1144 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1145 | `-- IBM-Memory_Key -> ../../sda
1147 | |-- swap -> ../../hda1
1148 | |-- date -> ../../sda1
1149 | `-- home -> ../../hda3
1151 |-- 2E08712B0870F2E7 -> ../../hda3
1152 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1153 |-- E845-7A89 -> ../../sda1
1154 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1156 The IMPORT= operation will import these keys in the environment and make
1157 it available for later PROGRAM= and RUN= executed programs. The keys are
1158 also stored in the udevdb and can be queried from there with one of the
1161 o A few binaries are silently added to the repository, which can be used
1162 to replay kernel events from initramfs instead of using coldplug. udevd
1163 can be instructed now to queue-up events while the stored events from
1164 initramfs are filled into the udevd-queue. This code is still under
1165 development and there is no documentation now besides the code itself.
1166 The additional binaries get compiled, but are not installed by default.
1168 o There is also a temporary fix for a performance problem where too many
1169 events happen in parallel and every event needs to parse the rules.
1170 udev can now read precompiled rules stored on disk. This is likely to be
1171 replaced by a more elegant solution in a future udev version.
1175 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1176 Fix for libsysfs not to expect this file was added.
1180 All rules are applied now, but only the first matching rule with a NAME-key
1181 will be applied. All later rules with NAME-key are completely ignored. This
1182 way system supplied symlinks or permissions gets applied to user-defined
1186 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1187 to some rules, to keep the old behavior.
1189 The rules are read on "remove"-events too. That makes is possible to match
1190 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1191 instruct udev to ignore an event (OPTIONS="ignore_device").
1192 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1194 The new RUN-key supports rule-based execution of programs after device-node
1195 handling. This is meant as a general replacement for the dev.d/-directories
1196 to give fine grained control over the execution of programs.
1198 The %s{}-sysfs format char replacement values are searched at any of the
1199 devices in the device chain now, not only at the class-device.
1201 We support log priority levels now. The value udev_log in udev.conf is used
1202 to determine what is printed to syslog. This makes it possible to
1203 run a version with compiled-in debug messages in a production environment
1204 which is sometimes needed to find a bug.
1205 It is still possible to supress the inclusion of _any_ syslog usage with
1206 USE_LOG=false to create the smallest possible binaries if needed.
1207 The configured udev_log value can be overridden with the environment variable
1212 Possible use of a system-wide klibc:
1213 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1214 will link against an external klibc and our own version will be ignored.
1218 We support an unlimited count of symlinks now.
1220 If USE_STATIC=true is passed to a glibc build, we link statically and use
1221 a built-in userdb parser to resolve user and group names.
1223 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1224 we walk up the chain of physical devices to find a match.
1226 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1227 easy to skip certain attribute matches without composing rules with weird
1228 character class negations like:
1229 KERNEL="[!s][!c][!d]*"
1230 this can now be replaced with:
1232 The current simple '=' is still supported, and should work as it does today,
1233 but existing rules should be converted if possible, to be better readable.
1235 We have new ENV{}== key now, to match against a maximum of 5 environment
1238 udevstart is its own binary again, because we don't need co carry this araound
1239 with every forked event.