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 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
21 if they are not the default. To support older kernels, the NAME= rules need to
22 be added to the compat rules file.
24 Symlinks to udevadm with the old command names are no longer resolved to
27 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.11 is
30 The option "last_rule" does no longer exist. Its use breaks too many
31 things which expect to be run from independent later rules, and is an idication
32 that something needs to be fixed properly instead.
38 The udevadm trigger "--retry-failed" option, which is replaced since quite
39 a while by "--type=failed" is removed.
41 The failed tracking was not working at all for a few releases. The RUN
42 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
43 default is not to track any failing RUN executions.
45 New keymaps, new modem, hid2hci updated.
49 Fix possible crash in udevd when worker processes are busy, rules are
50 changed at the same time, and workers get killed to reload the rules.
56 Properties set with ENV{.FOO}="bar" are marked private by starting the
57 name with a '.'. They will not be stored in the database, and not be
58 exported with the event.
60 Firmware files are looked up in:
61 /lib/firmware/updates/$(uname -r)
63 /lib/firmware/$(uname -r)
67 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
68 ata_id, instead of scsi_id, is the default tool now for ATA devices.
74 The configure options have changed because another library needs to be
75 installed in a different location. Instead of exec_prefix and udev_prefix,
76 libdir, rootlibdir and libexecdir are used. The Details are explained in
79 Event processes now get re-used after they handled an event. This reduces
80 the number of forks and the pressure on the CPU significantly, because
81 cloned event processes no longer cause page faults in the main daemon.
82 After the events have settled, a few worker processes stay around for
83 future events, all others get cleaned up.
85 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
86 Also inotify support is mandatory now to run udev.
88 The format of the queue exported by the udev damon has changed. There is
89 no longer a /dev/.udev/queue/ directory. The current event queue can be
90 accessed with udevadm settle and libudedv.
92 Libudev does not have the unstable API header anymore. From now on,
93 incompatible changes will be handled by bumping the library major version.
95 To build udev from the git tree gtk-doc is needed now. The tarballs will
96 build without it and contain the pre-built documentation. An online copy
98 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
100 The tools from the udev-extras repository have been merged into the main
101 udev repository. Some of the extras have larger external dependencies, and
102 they can be disabled with the configure switch --disable-extras.
108 The program vol_id and the library libvolume_id are removed from the
109 repository. Libvolume_id is merged with libblkid from the util-linux-ng
110 package. Persistent disk links for label and uuid depend on the
111 util-linux-ng version (2.15) of blkid now. Older versions of blkid
112 can not be used with udev.
114 Libudev allows to subscribe to udev events. To prevent unwanted messages
115 to be delivered, and waking up the subscribing process, a filter can be
116 installed, to drop messages inside a kernel socket filter. The filters
117 match on the <subsytem>:<devtype> properties of the device.
118 This is part of the ongoing effort to replace HAL, and switch current
119 users over to directly use libudev.
120 Libudev is still marked as experimental, and its interface might
121 eventually change if needed, but no major changes of the currently exported
122 interface are expected anymore, and a first stable release should happen
125 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
126 is not supported since while and udevd will log an error message at
127 startup. It should still be able to boot-up, but advanced rules and system
128 services which depend on the information not available in the old sysfs
129 format will fail to work correctly.
131 DVB device naming is supplied by the kernel now. In case older kernels
132 need to be supported, the old shell script should be added to a compat
139 The processed udev events get send back to the netlink socket. Libudev
140 provides access to these events. This is work-in-progress, to replace
141 the DeviceKit daemon functionality directly with libudev. There are
142 upcoming kernel changes to allow non-root users to subcribe to these
149 "udevadm settle" now optionally accepts a range of events to wait for,
150 instead of waiting for "all" events.
156 The installed watch for block device metadata changes is now removed
157 during event hadling, because some (broken) tools may be called from udev
158 rules and (wrongly) open the device with write access. After the finished
159 event handling the watch is restored.
165 Device nodes can be watched for changes with inotify with OPTIONS="watch".
166 If closed after being opened for writing, a "change" uevent will occur.
167 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
173 The udevadm test command has no longer a --force option, nodes and symlinks
174 are always updated with a test run now.
176 The udevd daemon can be started with --resolve-names=never to avoid all user
177 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
178 lookup user and groups every time events are handled.
184 We are currently merging the Ubuntu rules in the udev default rules,
185 and get one step closer to provide a common Linux /dev setup, regarding
186 device names, symlinks, and default device permissions. On udev startup,
187 we now expect the following groups to be resolvable to their ids with
189 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
190 LDAP setups need to make sure, that these groups are always resolvable at
191 bootup, with only the rootfs mounted, and without network access available.
193 Some systems may need to add some new, currently not used groups, or need
194 to add some users to new groups, but the cost of this change is minimal,
195 compared to the pain the current, rather random, differences between the
196 various distributions cause for upstream projects and third-party vendors.
198 In general, "normal" users who log into a machine should never be a member
199 of any such group, but the device-access should be managed by dynamic ACLs,
200 which get added and removed for the specific users on login/logout and
201 session activity/inactivity. These groups are only provided for custom setups,
202 and mainly system services, to allow proper privilege separation.
203 A video-streaming daemon uid would be a member of "audio" and "video", to get
204 access to the sound and video devices, but no "normal" user should ever belong
205 to the "audio" group, because he could listen to the built-in microphone with
206 any ssh-session established from the other side of the world.
208 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
209 which do not depend on the kernel device name. As usual, unique
210 devices - only a single one per product connected, or a real
211 USB serial number in the device - are always found with the same
212 name in the by-id/ directory.
213 Completely identical devices may overwrite their names in by-id/
214 and can only be found reliably in the by-path/ directory. Devices
215 specified by by-path/ must not change their connection, like the
216 USB port number they are plugged in, to keep their name.
218 To support some advanced features, Linux 2.6.22 is the oldest supported
219 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
220 supported. Older kernels should still work, and devices nodes should be
221 reliably created, but some rules and libudev will not work correctly because
222 the old kernels do not provide the expected information or interfaces.
228 Fix for a possible segfault while swapping network interface names in udev
235 The group "video" is part of the default rules now.
239 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
240 block devices in some cases. No common distro uses this option anymore,
241 and we do not get enough testing for this and recent udev versions. If
242 this option is not needed to run some old distro with a new kernel,
243 it should be disabled in the kernel config.
245 Bugfix for the $links substitution variable, which may crash if no links
246 are created. This should not happen in usual setups because we always
247 create /dev/{block,char}/ links.
249 The strings of the parsed rules, which are kept in memory, no longer
250 contain duplicate entries, or duplicate tails of strings. This, and the
251 new rules parsing/matching code reduces the total in-memory size of
252 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
255 The export of DEVTYPE=disk/partition got removed from the default
256 rules. This value is available from the kernel. The pnp shell script
257 modprobe hack is removed from the default rules. ACPI devices have _proper_
258 modalias support and take care of the same functionality.
259 Installations which support old kernels, but install current default
260 udev rules may want to add that to the compat rules file.
262 Libvolume_id now always probes for all known filesystems, and does not
263 stop at the first match. Some filesystems are marked as "exclusive probe",
264 and if any other filesytem type matches at the same time, libvolume_id
265 will, by default, not return any probing result. This is intended to prevent
266 mis-detection with conflicting left-over signatures found from earlier
267 file system formats. That way, we no longer depend on the probe-order
268 in case of multiple competing signatures. In some setups the kernel allows
269 to mount a volume with just the old filesystem signature still in place.
270 This may damage the new filesystem and cause data-loss, just by mounting
271 it. Because volume_id can not decide which one the correct signature is,
272 the wrong signatures need to be removed manually from the volume, or the
273 volume needs to be reformatted, to enable filesystem detection and possible
278 Fix segfault if compiled without optimization and dbg() does not get
279 compiled out and uses variables which are not available.
283 Bugfixes. (And maybe new bugs. :))
285 The rule matching engine got converted from a rule list to a token
286 array which reduced the in-memory rules representation of a full
287 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
288 Limits like 5 ENV and ATTR matches, and one single instance for most
289 other keys per rule are gone.
291 The NAME assignment is no longer special cased. If later rules assign
292 a NAME value again, the former value will be overwritten. As usual
293 for most other keys, the NAME value can be protected by doing a final
294 assignment with NAME:="<value>".
296 All udev code now uses libudev, which is also exported. The library
297 is still under development, marked as experimental, and its interface
298 may change as long as the DeviceKit integration is not finished.
300 Many thanks to Alan Jenkins for his continuous help, and finding and
301 optimizing some of the computing expensive parts.
307 Kernel devices and device nodes are connected now by reverse indizes in
308 /sys and /dev. A device number retrieved by a stat() or similar, the
309 kernel device directory can be found by looking up:
310 /sys/dev/{block,char}/<maj>:<min>
311 and the device node of the same device by looking up:
312 /dev/{block,char}/<maj>:<min>
316 Fix recently introduced bug, which caused a compilation without large
317 file support, where vol_id does not recognize raid signatures at the end
320 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
321 Seems some kernel versions prevent the creation of the ieee-* links,
322 so people used the scsi-* link which disappeared now.
324 More libudev work. Almost all udevadm functionality comes from libudev
327 udevadm trigger has a new option --type, which allows to trigger events
328 for "devices", for "subsystems", or "failed" devices. The old option
329 --retry-failed" still works, but is no longer mentioned in the man page.
335 The udevadm info --device-id-of-file= output has changed to use
336 the obvious format. Possible current users should use the --export
337 option which is not affected.
339 The old udev commands symlinks to udevadm are not installed, if
340 these symlinks are used, a warning is printed.
346 Optical drive's media is no longer probed for raid signatures,
347 reading the end of the device causes some devices to malfunction.
348 Also the offset of the last session found is used now to probe
351 The volume_id library got a major version number update to 1,
352 some deprecated functions are removed.
354 A shared library "libudev" gets installed now to provide access
355 to udev device information. DeviceKit, the successor of HAL, will
356 need this library to access the udev database and search sysfs for
358 The library is currently in an experimental state, also the API is
359 expected to change, as long as the DeviceKit integration is not
364 We use ./configure now. See INSTALL for details. Current
367 "/usr" - prefix for man pages, include files
369 "" - the root filesystem, prefix for libs and binaries
373 "lib" - directory name for libraries, not a path name
374 multilib 64bit systems may use "lib64" instead of "lib"
376 compile-in verbose debug messages
378 disable all logging and compile-out all log strings
380 link against SELInux libraries, to set the expected context
383 In the default rules, the group "disk" gets permissions 0660 instead
384 of 0640. One small step closer to unify distro rules. Some day, all
385 distros hopefully end up with the same set of rules.
387 No symlinks to udevadm are installed anymore, if they are still needed,
388 they should be provided by the package.
394 Default udev rules, which are not supposed to be edited by the user, should
395 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
396 the udev package and will be replaced with an update. Udev will pick up rule
398 /lib/udev/rules.d/ - default installed rules
399 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
400 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
401 It does not matter in which directory a rule file lives, all files are sorted
404 To help creating /dev/root, we have now:
405 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
408 In case the current --device-id-of-file is already used, please switch to
409 the --export format version, it saves the output parsing and the old
410 format will be changed to use ':' as a separator, like the format in the
415 Fix cdrom_id to properly recognize blank media.
421 Tape drive id-data is queried from /dev/bsg/* instead of the tape
422 nodes. This avoids rewinding tapes on open().
428 The symlinks udevcontrol and udevtrigger are no longer installed by
431 The scsi_id program does not depend on sysfs anymore. It can speak
432 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
433 data, which should solve some old problems with tape devices, where
434 we better do not open all tape device nodes to identify the device.
440 The cdrom_id program is replaced by an advanced version, which can
441 detect most common device types, and also properties of the inserted
442 media. This is part of moving some basic functionality from HAL into
443 udev (and the kernel).
449 The last WAIT_FOR_SYSFS rule is removed from the default rules.
451 The symlinks to udevadm for the debugging tools: udevmonitor and
452 udevtest are no longer created.
454 The symlinks to the udevadm man page for the old tool names are
457 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
458 should be prefixed with '@' to indicate that the path is not a
469 Udevstart is removed from the tree, it did not get installed for
470 a long time now, and is long replaced by trigger and settle.
476 All udev tools are merged into a single binary called udevadm.
477 The old names of the tools are built-in commands in udevadm now.
478 Symlinks to udevadm, with the names of the old tools, provide
479 the same functionality as the standalone tools. There is also
480 only a single udevadm.8 man page left for all tools.
482 Tools like mkinitramfs should be checked, if they need to include
483 udevadm in the list of files.
493 The etc/udev/rules.d/ directory now contains a default set of basic
494 udev rules. This initial version is the result of a rules file merge
495 of Fedora and openSUSE. For these both distros only a few specific
496 rules are left in their own file, named after the distro. Rules which
497 are optionally installed, because they are only valid for a specific
498 architecture, or rules for subsystems which are not always used are
499 in etc/udev/packages/.
505 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
506 actions by dynamically created rules.
508 SYMLINK=="<value>" matches agains the entries in the list of
509 currently defined symlinks. The links are not created in the
510 filesystem at that point in time, but the values can be matched.
512 RUN{ignore_error}+="<program>" will ignore any exit code from the
513 program and not record as a failed event.
519 Final merge of patches/features from the Ubuntu package.
525 Control characters in filesystem label strings are no longer silenty
526 removed, but hex-encoded, to be able to uniquely identify the device
527 by its symlink in /dev/disk/by-label/.
528 If libvolume_id is used by mount(8), LABEL= will work as expected,
529 if slashes or other characters are used in the label string.
531 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
532 can be specified now. The TEST key accepts an optional mode mask
533 TEST{0100}=="<is executable file>".
535 Scsi_id now supports a mode without expecting scsi-specific sysfs
536 entries to allow the extraction of cciss-device persistent properties.
542 In the future, we may see uuid's which are just simple character
543 strings (see the DDF Raid Specification). For that reason vol_id now
544 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
545 the creation of symlinks, the *_SAFE values ensure, that no control
546 or whitespace characters are used in the filename.
548 Possible users of libvolume_id, please use the volume_id_get_* functions.
549 The public struct will go away in a future release of the library.
555 Removal of useless extras/eventrecorder.sh.
565 The directory multiplexer for dev.d/ and hotplug.d are finally removed
566 from the udev package.
572 Symlinks can have priorities now, the priority is assigned to the device
573 and specified with OPTIONS="link_priority=100". Devices with higher
574 priorities overwrite the symlinks of devices with lower priorities.
575 If the device that currently owns the link, goes away, the symlink
576 will be removed, and recreated, pointing to the next device with the
577 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
578 more reliable, if multiple devices contain the same metadata and overwrite
581 The dasd_id program is removed from the udev tree, and dasdinfo, with the
582 needed rules, are part of the s390-tools now.
584 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
585 we may get the scsi sysfs mess fixed some day, and this will only catch
586 the devices we are looking for.
588 USB serial numbers for storage devices have the target:lun now appended,
589 to make it possibble to distinguish broken multi-lun devices with all
590 the same SCSI identifiers.
592 Note: The extra "run_directory" which searches and executes stuff in
593 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
594 with the next release. Make sure, that you don't use it anymore, or
595 provides your own implementation of that inefficient stuff.
596 We are tired of reports about a "slow udev", because these directories
597 contain stuff, that runs with _every_ event, instead of using rules,
598 that run programs only for the matching events.
608 DRIVER== will match only for devices that actually have a real
609 driver. DRIVERS== must be used, if parent devices should be
610 included in the match.
612 Libvolume_id's "linux_raid" detection needed another fix.
620 Add additional check to volume_id detection of via_raid, cause
621 some company decided to put a matching pattern all over the empty
622 storage area of their music players.
626 Fix path_id for SAS devices.
630 The udev daemon can be started with --debug-trace now, which will
631 execute all events serialized to get a chance to catch a possible
632 action that crashes the box.
634 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
635 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
636 are excluded from the warning. Referencing parent attributes directly
637 may break when something in the kernel driver model changes. Udev will
638 just find the attribute by walking up the parent chain.
640 Udevtrigger now sorts the list of devices depending on the device
641 dependency, so a "usb" device is triggered after the parent "pci"
646 Revert persistent-storage ata-serial '_' '-' replacement.
652 Udevtrigger can now filter the list of devices to be triggered. Matches
653 for subsystems or sysfs attributes can be specified.
655 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
656 zero-sized files to avoid pointing to /sys and confuse broken tools which
657 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
660 The rules and scripts to create udev rules for persistent network
661 devices and optical drives are in the extras/rules_generator directory
662 now. If you use something similar, please consider replacing your own
663 version with this, to share the support effort. The rule_generator
664 installs its own rules into /etc/udev/rules.d.
666 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
667 the rule_generator depends on cdrom_id to be called in an earlier rule.
673 Renaming of some key names (the old names still work):
674 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
675 (The behavior of the key DRIVER will change soon in one of the next
676 releases, to match only the event device, please switch to DRIVERS
677 instead. If DRIVER is used, it will behave like DRIVERS, but an error
679 With the new key names, we have a more consistent and simpler scheme.
680 We can match the properties of the event device only, with: KERNEL,
681 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
682 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
683 longer mentioned in the man page and should be switched in the rule
686 ATTR{file}="value" can be used now, to write to a sysfs file of the
687 event device. Instead of:
688 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
690 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
692 All the PHYSDEV* keys are deprecated and will be removed from a
694 PHYDEVPATH - is the path of a parent device and should not be
696 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
697 matched with SUBSYSTEMS==
698 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
699 Newer kernels will have DRIVER in the environment,
700 for older kernels udev puts in. Class device will
701 no longer carry this property of a parent and
702 DRIVERS== can be used to match such a parent value.
703 Note that ENV{DRIVER} is only available for a few bus devices, where
704 the driver is already bound at device event time. On coldplug, the
705 events for a lot devices are already bound to a driver, and they will have
706 that value set. But on hotplug, at the time the kernel creates the device,
707 it can't know what driver may claim the device after that, therefore
708 in most cases it will be empty.
710 Failed events should now be re-triggered with:
711 udevtrigger --retry-failed.
712 Please switch to this command, so we keep the details of the /dev/.udev/failed/
713 files private to the udev tools. We may need to switch the current symlink
714 target, cause some obviously broken tools try to scan all files in /dev
715 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
716 million times. This takes ages on slow boxes.
718 The udevinfo attribute walk (-a) now works with giving a device node
719 name (-n) instead of a devpath (-p). The query now always works, also when
720 no database file was created by udev.
722 The built-in /etc/passwd /etc/group parser is removed, we always depend on
723 getpwnam() and getgrnam() now. One of the next releases will depend on
724 fnmatch() and may use getopt_long().
728 Bugfixes and small improvements.
732 Fix path_id for recent kernels.
738 Added support for swapping network interface names, by temporarily
739 renaming the device and wait for the target name to become free.
743 The built-in MODALIAS key and substitution is removed.
747 The binary firmware helper is replaced by the usual simple
748 shell script. Udevsend is removed from the tree.
756 Some more keys require the correct use of '==' and '=' depending
757 on the kind of operation beeing an assignment or a match. Rules
758 with invalid operations are skipped and logged to syslog. Please
759 test with udevtest if the parsing of your rules throws errors and
760 fix possibly broken rules.
764 Provide "udevsettle" to wait for all current udev events to finish.
765 It also watches the current kernel netlink queue by comparing the
766 even sequence number to make sure that there are no current pending
767 events that have not already arrived in the daemon.
771 Fix rule to skip persistent rules for removable IDE devices, which
772 also skipped optical IDE drives.
774 All *_id program are installed in /lib/udev/ by default now.
776 No binary is stripped anymore as this should be done in the
777 packaging process and not at build time.
779 libvolume_id is provided as a shared library now and vol_id is
780 linked against it. Also one of the next HAL versions will require
781 this library, and the HAL build process will also require the
782 header file to be installed. The copy of the same code in HAL will
783 be removed to have only a single copy left on the system.
787 Add persistent links for SCSI tapes. The rules file is renamed
788 to 60-persistent-storage.rules.
790 Create persistent path for usb devices. Can be used for all sorts
791 of devices that can't be distinguished by other properties like
792 multiple identical keyboards and mice connected to the same box.
794 Provide "udevtrigger" program to request events on coldplug. The
795 shell script is much too slow with thousends of devices.
799 Fix persistent disk rules to exclude removable IDE drives.
801 Warn if %e, $modalias or MODALIAS is used.
805 Fix queue export, which wasn't correct for subsequent add/remove
806 events for the same device.
810 Fix cramfs detection on big endian.
812 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
817 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
818 attributes were only checked at the parent device that matched the
819 by BUS requested subsystem. Fix it to also look at the device we
820 received the event for.
822 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
827 Fix a bug where NAME="" would prevent RUN from beeing executed.
829 RUN="/bin/program" does not longer automatically add the subsystem
830 as the first parameter. This is from the days of /sbin/hotplug
831 which is dead now and it's just confusing to need to add a space at
832 the end of the program name to prevent this.
833 If you use rules that need the subsystem as the first parameter,
834 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
835 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
839 The udev man page has moved to udev(7) as it does not describe a command
840 anymore. The programs udev, udevstart and udevsend are no longer installed
841 by default and must be copied manually, if they should be installed or
842 included in a package.
844 Fix a bug where "ignore_device" could run earlier collected RUN keys before
845 the ignore rule was applied.
847 More preparation for future sysfs changes. usb_id and scsi_id no longer
848 depend on a magic order of devices in the /devices chain. Specific devices
849 should be requested by their subsytem.
851 This will always find the scsi parent device without depending on a specific
853 dev = sysfs_device_get(devpath);
854 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
856 The "device" link in the current sysfs layout will be automatically
857 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
858 parent in the devpath. If a device is requested by it's symlink, like all
859 class devices in the new sysfs layout will look like, it gets automatically
860 resolved and substituted with the real devpath and not the symlink path.
863 A similar logic must be applied to _all_ sysfs users, including
864 scripts, that search along parent devices in sysfs. The explicit use of
865 the "device" link must be avoided. With the future sysfs layout all
866 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
867 back to the "class" or the "bus". The layout of the parent devices in
868 /devices is not necessarily expected to be stable across kernel releases and
869 searching for parents by their subsystem should make sysfs users tolerant
870 for changed parent chains.
874 Prepare udev to work with the experimental kernel patch, that moves
875 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
877 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
878 moving the class devices to /sys/devices.
880 Thanks again to Marco for help finding a hopefully nice compromise
881 to make %b simpler and working again.
885 Complete removal of libsysfs, replaced by simple helper functions
886 which are much simpler and a bit faster. The udev daemon operatesentirely
887 on event parameters and does not use sysfs for simple rules anymore.
888 Please report any new bugs/problems, that may be caused by this big
889 change. They will be fixed immediately.
891 The enumeration format character '%e' is deprecated and will be
892 removed sometimes from a future udev version. It never worked correctly
893 outside of udevstart, so we can't use it with the new parallel
894 coldplug. A simple enumeration is as useless as the devfs naming
895 scheme, just get rid of both if you still use it.
897 MODALIAS and $modalias is not needed and will be removed from one of
898 the next udev versions, replace it in all rules with ENV{MODALIAS} or
899 the sysfs "modalias" value.
901 Thanks a lot to Marco for all his help on finding and fixing bugs.
905 Let scsi_id request libata drive serial numbers from page 0x80.
907 Renamed etc/udev/persistent.rules to persistent-disk.rules and
908 added /dev/disk/by-name/* for device mapper device names.
910 Removed %e from the man page. It never worked reliably outside
911 of udevstart and udevstart is no longer recommended to use.
915 Symlinks are now exported to the event environment. Hopefully it's no
916 longer needed to run udevinfo from an event process, like it was
917 mentioned on the hotplug list:
918 UDEV [1134776873.702967] add@/block/sdb
921 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
925 Fix a problem if udevsend is used as the hotplug handler and tries to use
926 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
927 and this kind of problems will hopefully go away soon.
931 All built-in logic to work around bad sysfs timing is removed with this
932 version. The need to wait for sysfs files is almost fixed with a kernel
933 version that doesn't work with this udev version anyway. Until we fix
934 the timing of the "bus" link creation, the former integrated logic should
935 be emulated by a rule placed before all other rules:
936 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
938 The option "udev_db" does no longer exist. All udev state will be in
939 /$udev_root/.udev/ now, there is no longer an option to set this
941 If the init script or something else used this value, just depend on
942 this hardcoded path. But remember _all_content_ of this directory is
943 still private to udev and can change at any time.
945 Default location for rule sripts and helper programs is now: /lib/udev/.
946 Everything that is not useful on the commandline should go into this
947 directory. Some of the helpers in the extras folder are installed there
948 now. The rules need to be changed, to find the helpers there.
950 Also /lib/udev/devices is recommended as a directory where packages or
951 the user can place real device nodes, which get copied over to /dev at
952 every boot. This should replace the various solutions with custom config
955 Udevsend does no longer start the udev daemon. This must be done with
956 the init script that prepares /dev on tmpfs and creates the initial nodes,
957 before starting the daemon.
961 Silent a too verbose error logging for the old hotplug.d/ dev.d/
964 The copy of klibc is removed. A systemwide installed version of klibc
965 should be used to build a klibc udev now.
969 NAME="" will not create any nodes, but execute RUN keys. To completely
970 ignore an event the OPTION "ignore_device" should be used.
972 After removal of the reorder queue, events with a TIMEOUT can be executed
973 without any queuing now.
977 Fixed bug in udevd, if inotify is not available. We depend on netlink
978 uevents now, kernels without that event source will not work with that
979 version of udev anymore.
983 The rule parsing happens now in the daemon once at startup, all udev
984 event processes inherit the already parsed rules from the daemon.
985 It is shipped with SUSE10.0 and reduces heavily the system load at
986 startup. The option to save precompiled rules and let the udev process
987 pick the them up is removed, as it's no longer needed.
989 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
990 device. Libsysfs is changed to "translate" the requested link into the
991 real device path, as it would happen with the hotplug event. Otherwise
992 device removal and the udev database will not work.
994 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
997 A few improvements for vol_id, the filesytem probing code.
1001 Fix a stupid typo in extras/run_directory for "make install".
1003 scsi_id creates the temporary devnode now in /dev for usage with a
1004 non-writable /tmp directory.
1006 The uevent kernel socket buffer can carry app. 50.000 events now,
1007 let's see who can break this again. :)
1009 The upcoming kernel will have a new input driver core integration.
1010 Some class devices are now symlinks to the real device. libsysfs
1011 needs a fix for this to work correctly. Udevstart of older udev
1012 versions will _not_ create these devices!
1016 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1021 A bunch of mostly trivial bugfixes. From now on no node name or
1022 symlink name can contain any character than plain whitelisted ascii
1023 characters or validated utf8 byte-streams. This is needed for the
1024 /dev/disk/by-label/* links, because we import untrusted data and
1025 export it to the filesystem.
1029 More bugfixes. If udevd was started from the kernel, we don't
1030 have stdin/stdout/stderr, which broke the forked tools in some
1035 Bugfix. udevstart event ordering was broken for a long time.
1036 The new run_program() uncovered it, because /dev/null was not
1037 available while we try to run external programs.
1038 Now udevstart should create it before we run anything.
1042 Minor bugfixes and some distro rules updates. If you don't have the
1043 persistent disk rules in /dev/disk/by-*/* on your distro, just
1044 grab it from here. :)
1048 We can use socket communication now to pass events from udev to
1050 RUN+="socket:/org/freedesktop/hal/udev_event"
1051 will pass the whole udev event to the HAL daemon without the need
1052 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1056 Mostly bugfixes and see ChangeLog.
1058 The test for the existence of an environment value should be
1060 ENV{KEY}=="*" to ENV{KEY}=="?*"
1061 because "*" will not fail anymore, if the key does not exist or
1066 Bugfixes and a few tweaks described in the ChangeLog.
1070 Mostly a Bugfix release.
1072 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1073 timing with custom rules.
1077 We changed the internal rule storage format. Our large rule files took
1078 2 MB of RAM, with the change we are down to 99kB.
1080 If the device-node has been created with default name and no symlink or
1081 options are to remenber, it is not longer stored in the udevdb. HAL will
1082 need to be updated to work correctly with that change.
1084 To overrride optimization flags, OPTFLAGS may be used now.
1092 Major changes happened with this release. The goal is to take over the
1093 complete kernel-event handling and provide a more efficient way to dispatch
1094 kernel events. Replacing most of the current shell script logic and the
1095 kernel forked helper with a netlink-daemon and a rule-based event handling.
1097 o udevd listens to netlink events now. The first valid netlink event
1098 will make udevd ignore any message from udevsend that contains a
1099 SEQNUM, to avoid duplicate events. The forked events can be disabled
1101 echo "" > /proc/sys/kernel/hotplug
1102 For full support, the broken input-subsytem needs to be fixed, not to
1103 bypass the driver core.
1105 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1106 removed from udev itself and must be emulated by calling small
1107 helper binaries provided in the extras folder:
1108 make EXTRAS=extras/run_directory/
1109 will build udev_run_devd and udev_run_hotplugd, which can be called
1110 from a rule if needed:
1111 RUN+="/sbin/udev_run_hotplugd"
1112 The recommended way to handle this is to convert all the calls from
1113 the directories to explicit udev rules and get completely rid of the
1114 multiplexing. (To catch a ttyUSB event, you now no longer need to
1115 fork and exit 300 tty script instances you are not interested in, it
1116 is just one rule that matches exactly the device.)
1118 o udev handles now _all_ events not just events for class and block
1119 devices, this way it is possible to control the complete event
1120 behavior with udev rules. Especially useful for rules like:
1121 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1123 o As used in the modalias rule, udev supports now textual
1124 substitution placeholder along with the usual format chars. This
1125 needs to be documented, for now it's only visible in udev_rules_parse.c.
1127 o The rule keys support now more operations. This is documented in the
1128 man page. It is possible to add values to list-keys like the SYMLINK
1129 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1130 Also "final"-assignments are supported by using KEY:="value", which will
1131 prevent changing the key by any later rule.
1133 o kernel 2.6.12 has the "detached_state" attribute removed from
1134 sysfs, which was used to recognize sysfs population. We switched that
1135 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1136 Running this udev version on older kernels may cause a short delay for
1139 o To provide infrastructure for persistent device naming, the id programs:
1140 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1141 to export the probed data in environment key format:
1142 pim:~ # /sbin/ata_id --export /dev/hda
1143 ID_MODEL=HTS726060M9AT00
1144 ID_SERIAL=MRH401M4G6UM9B
1145 ID_REVISION=MH4OA6BA
1147 The following rules:
1148 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1149 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1152 kay@pim:~> tree /dev/disk
1155 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1156 | `-- IBM-Memory_Key -> ../../sda
1158 | |-- swap -> ../../hda1
1159 | |-- date -> ../../sda1
1160 | `-- home -> ../../hda3
1162 |-- 2E08712B0870F2E7 -> ../../hda3
1163 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1164 |-- E845-7A89 -> ../../sda1
1165 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1167 The IMPORT= operation will import these keys in the environment and make
1168 it available for later PROGRAM= and RUN= executed programs. The keys are
1169 also stored in the udevdb and can be queried from there with one of the
1172 o A few binaries are silently added to the repository, which can be used
1173 to replay kernel events from initramfs instead of using coldplug. udevd
1174 can be instructed now to queue-up events while the stored events from
1175 initramfs are filled into the udevd-queue. This code is still under
1176 development and there is no documentation now besides the code itself.
1177 The additional binaries get compiled, but are not installed by default.
1179 o There is also a temporary fix for a performance problem where too many
1180 events happen in parallel and every event needs to parse the rules.
1181 udev can now read precompiled rules stored on disk. This is likely to be
1182 replaced by a more elegant solution in a future udev version.
1186 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1187 Fix for libsysfs not to expect this file was added.
1191 All rules are applied now, but only the first matching rule with a NAME-key
1192 will be applied. All later rules with NAME-key are completely ignored. This
1193 way system supplied symlinks or permissions gets applied to user-defined
1197 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1198 to some rules, to keep the old behavior.
1200 The rules are read on "remove"-events too. That makes is possible to match
1201 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1202 instruct udev to ignore an event (OPTIONS="ignore_device").
1203 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1205 The new RUN-key supports rule-based execution of programs after device-node
1206 handling. This is meant as a general replacement for the dev.d/-directories
1207 to give fine grained control over the execution of programs.
1209 The %s{}-sysfs format char replacement values are searched at any of the
1210 devices in the device chain now, not only at the class-device.
1212 We support log priority levels now. The value udev_log in udev.conf is used
1213 to determine what is printed to syslog. This makes it possible to
1214 run a version with compiled-in debug messages in a production environment
1215 which is sometimes needed to find a bug.
1216 It is still possible to supress the inclusion of _any_ syslog usage with
1217 USE_LOG=false to create the smallest possible binaries if needed.
1218 The configured udev_log value can be overridden with the environment variable
1223 Possible use of a system-wide klibc:
1224 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1225 will link against an external klibc and our own version will be ignored.
1229 We support an unlimited count of symlinks now.
1231 If USE_STATIC=true is passed to a glibc build, we link statically and use
1232 a built-in userdb parser to resolve user and group names.
1234 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1235 we walk up the chain of physical devices to find a match.
1237 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1238 easy to skip certain attribute matches without composing rules with weird
1239 character class negations like:
1240 KERNEL="[!s][!c][!d]*"
1241 this can now be replaced with:
1243 The current simple '=' is still supported, and should work as it does today,
1244 but existing rules should be converted if possible, to be better readable.
1246 We have new ENV{}== key now, to match against a maximum of 5 environment
1249 udevstart is its own binary again, because we don't need co carry this araound
1250 with every forked event.
~ianmdlvl / elogind.git / blob