5 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
7 Properties set with ENV{.FOO}="bar" are marked private by starting the
8 name with a '.'. They will not be stored in the database, and not be
9 exported with the event.
15 The configure options have changed because another library needs to be
16 installed in a different location. Instead of exec_prefix and udev_prefix,
17 libdir, rootlibdir and libexecdir are used. The Details are explained in
20 Event processes now get re-used after they handled an event. This reduces
21 the number of forks and the pressure on the CPU significantly, because
22 cloned event processes no longer cause page faults in the main daemon.
23 After the events have settled, a few worker processes stay around for
24 future events, all others get cleaned up.
26 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
27 Also inotify support is mandatory now to run udev.
29 The format of the queue exported by the udev damon has changed. There is
30 no longer a /dev/.udev/queue/ directory. The current event queue can be
31 accessed with udevadm settle and libudedv.
33 Libudev does not have the unstable API header anymore. From now on,
34 incompatible changes will be handled by bumping the library major version.
36 To build udev from the git tree gtk-doc is needed now. The tarballs will
37 build without it and contain the pre-built documentation. An online copy
39 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
41 The tools from the udev-extras repository have been merged into the main
42 udev repository. Some of the extras have larger external dependencies, and
43 they can be disabled with the configure switch --disable-extras.
49 The program vol_id and the library libvolume_id are removed from the
50 repository. Libvolume_id is merged with libblkid from the util-linux-ng
51 package. Persistent disk links for label and uuid depend on the
52 util-linux-ng version (2.15) of blkid now. Older versions of blkid
53 can not be used with udev.
55 Libudev allows to subscribe to udev events. To prevent unwanted messages
56 to be delivered, and waking up the subscribing process, a filter can be
57 installed, to drop messages inside a kernel socket filter. The filters
58 match on the <subsytem>:<devtype> properties of the device.
59 This is part of the ongoing effort to replace HAL, and switch current
60 users over to directly use libudev.
61 Libudev is still marked as experimental, and its interface might
62 eventually change if needed, but no major changes of the currently exported
63 interface are expected anymore, and a first stable release should happen
66 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
67 is not supported since while and udevd will log an error message at
68 startup. It should still be able to boot-up, but advanced rules and system
69 services which depend on the information not available in the old sysfs
70 format will fail to work correctly.
72 DVB device naming is supplied by the kernel now. In case older kernels
73 need to be supported, the old shell script should be added to a compat
80 The processed udev events get send back to the netlink socket. Libudev
81 provides access to these events. This is work-in-progress, to replace
82 the DeviceKit daemon functionality directly with libudev. There are
83 upcoming kernel changes to allow non-root users to subcribe to these
90 "udevadm settle" now optionally accepts a range of events to wait for,
91 instead of waiting for "all" events.
97 The installed watch for block device metadata changes is now removed
98 during event hadling, because some (broken) tools may be called from udev
99 rules and (wrongly) open the device with write access. After the finished
100 event handling the watch is restored.
106 Device nodes can be watched for changes with inotify with OPTIONS="watch".
107 If closed after being opened for writing, a "change" uevent will occur.
108 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
114 The udevadm test command has no longer a --force option, nodes and symlinks
115 are always updated with a test run now.
117 The udevd daemon can be started with --resolve-names=never to avoid all user
118 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
119 lookup user and groups every time events are handled.
125 We are currently merging the Ubuntu rules in the udev default rules,
126 and get one step closer to provide a common Linux /dev setup, regarding
127 device names, symlinks, and default device permissions. On udev startup,
128 we now expect the following groups to be resolvable to their ids with
130 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
131 LDAP setups need to make sure, that these groups are always resolvable at
132 bootup, with only the rootfs mounted, and without network access available.
134 Some systems may need to add some new, currently not used groups, or need
135 to add some users to new groups, but the cost of this change is minimal,
136 compared to the pain the current, rather random, differences between the
137 various distributions cause for upstream projects and third-party vendors.
139 In general, "normal" users who log into a machine should never be a member
140 of any such group, but the device-access should be managed by dynamic ACLs,
141 which get added and removed for the specific users on login/logout and
142 session activity/inactivity. These groups are only provided for custom setups,
143 and mainly system services, to allow proper privilege separation.
144 A video-streaming daemon uid would be a member of "audio" and "video", to get
145 access to the sound and video devices, but no "normal" user should ever belong
146 to the "audio" group, because he could listen to the built-in microphone with
147 any ssh-session established from the other side of the world.
149 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
150 which do not depend on the kernel device name. As usual, unique
151 devices - only a single one per product connected, or a real
152 USB serial number in the device - are always found with the same
153 name in the by-id/ directory.
154 Completely identical devices may overwrite their names in by-id/
155 and can only be found reliably in the by-path/ directory. Devices
156 specified by by-path/ must not change their connection, like the
157 USB port number they are plugged in, to keep their name.
159 To support some advanced features, Linux 2.6.22 is the oldest supported
160 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
161 supported. Older kernels should still work, and devices nodes should be
162 reliably created, but some rules and libudev will not work correctly because
163 the old kernels do not provide the expected information or interfaces.
169 Fix for a possible segfault while swapping network interface names in udev
176 The group "video" is part of the default rules now.
180 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
181 block devices in some cases. No common distro uses this option anymore,
182 and we do not get enough testing for this and recent udev versions. If
183 this option is not needed to run some old distro with a new kernel,
184 it should be disabled in the kernel config.
186 Bugfix for the $links substitution variable, which may crash if no links
187 are created. This should not happen in usual setups because we always
188 create /dev/{block,char}/ links.
190 The strings of the parsed rules, which are kept in memory, no longer
191 contain duplicate entries, or duplicate tails of strings. This, and the
192 new rules parsing/matching code reduces the total in-memory size of
193 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
196 The export of DEVTYPE=disk/partition got removed from the default
197 rules. This value is available from the kernel. The pnp shell script
198 modprobe hack is removed from the default rules. ACPI devices have _proper_
199 modalias support and take care of the same functionality.
200 Installations which support old kernels, but install current default
201 udev rules may want to add that to the compat rules file.
203 Libvolume_id now always probes for all known filesystems, and does not
204 stop at the first match. Some filesystems are marked as "exclusive probe",
205 and if any other filesytem type matches at the same time, libvolume_id
206 will, by default, not return any probing result. This is intended to prevent
207 mis-detection with conflicting left-over signatures found from earlier
208 file system formats. That way, we no longer depend on the probe-order
209 in case of multiple competing signatures. In some setups the kernel allows
210 to mount a volume with just the old filesystem signature still in place.
211 This may damage the new filesystem and cause data-loss, just by mounting
212 it. Because volume_id can not decide which one the correct signature is,
213 the wrong signatures need to be removed manually from the volume, or the
214 volume needs to be reformatted, to enable filesystem detection and possible
219 Fix segfault if compiled without optimization and dbg() does not get
220 compiled out and uses variables which are not available.
224 Bugfixes. (And maybe new bugs. :))
226 The rule matching engine got converted from a rule list to a token
227 array which reduced the in-memory rules representation of a full
228 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
229 Limits like 5 ENV and ATTR matches, and one single instance for most
230 other keys per rule are gone.
232 The NAME assignment is no longer special cased. If later rules assign
233 a NAME value again, the former value will be overwritten. As usual
234 for most other keys, the NAME value can be protected by doing a final
235 assignment with NAME:="<value>".
237 All udev code now uses libudev, which is also exported. The library
238 is still under development, marked as experimental, and its interface
239 may change as long as the DeviceKit integration is not finished.
241 Many thanks to Alan Jenkins for his continuous help, and finding and
242 optimizing some of the computing expensive parts.
248 Kernel devices and device nodes are connected now by reverse indizes in
249 /sys and /dev. A device number retrieved by a stat() or similar, the
250 kernel device directory can be found by looking up:
251 /sys/dev/{block,char}/<maj>:<min>
252 and the device node of the same device by looking up:
253 /dev/{block,char}/<maj>:<min>
257 Fix recently introduced bug, which caused a compilation without large
258 file support, where vol_id does not recognize raid signatures at the end
261 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
262 Seems some kernel versions prevent the creation of the ieee-* links,
263 so people used the scsi-* link which disappeared now.
265 More libudev work. Almost all udevadm functionality comes from libudev
268 udevadm trigger has a new option --type, which allows to trigger events
269 for "devices", for "subsystems", or "failed" devices. The old option
270 --retry-failed" still works, but is no longer mentioned in the man page.
276 The udevadm info --device-id-of-file= output has changed to use
277 the obvious format. Possible current users should use the --export
278 option which is not affected.
280 The old udev commands symlinks to udevadm are not installed, if
281 these symlinks are used, a warning is printed.
287 Optical drive's media is no longer probed for raid signatures,
288 reading the end of the device causes some devices to malfunction.
289 Also the offset of the last session found is used now to probe
292 The volume_id library got a major version number update to 1,
293 some deprecated functions are removed.
295 A shared library "libudev" gets installed now to provide access
296 to udev device information. DeviceKit, the successor of HAL, will
297 need this library to access the udev database and search sysfs for
299 The library is currently in an experimental state, also the API is
300 expected to change, as long as the DeviceKit integration is not
305 We use ./configure now. See INSTALL for details. Current
308 "/usr" - prefix for man pages, include files
310 "" - the root filesystem, prefix for libs and binaries
314 "lib" - directory name for libraries, not a path name
315 multilib 64bit systems may use "lib64" instead of "lib"
317 compile-in verbose debug messages
319 disable all logging and compile-out all log strings
321 link against SELInux libraries, to set the expected context
324 In the default rules, the group "disk" gets permissions 0660 instead
325 of 0640. One small step closer to unify distro rules. Some day, all
326 distros hopefully end up with the same set of rules.
328 No symlinks to udevadm are installed anymore, if they are still needed,
329 they should be provided by the package.
335 Default udev rules, which are not supposed to be edited by the user, should
336 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
337 the udev package and will be replaced with an update. Udev will pick up rule
339 /lib/udev/rules.d/ - default installed rules
340 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
341 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
342 It does not matter in which directory a rule file lives, all files are sorted
345 To help creating /dev/root, we have now:
346 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
349 In case the current --device-id-of-file is already used, please switch to
350 the --export format version, it saves the output parsing and the old
351 format will be changed to use ':' as a separator, like the format in the
356 Fix cdrom_id to properly recognize blank media.
362 Tape drive id-data is queried from /dev/bsg/* instead of the tape
363 nodes. This avoids rewinding tapes on open().
369 The symlinks udevcontrol and udevtrigger are no longer installed by
372 The scsi_id program does not depend on sysfs anymore. It can speak
373 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
374 data, which should solve some old problems with tape devices, where
375 we better do not open all tape device nodes to identify the device.
381 The cdrom_id program is replaced by an advanced version, which can
382 detect most common device types, and also properties of the inserted
383 media. This is part of moving some basic functionality from HAL into
384 udev (and the kernel).
390 The last WAIT_FOR_SYSFS rule is removed from the default rules.
392 The symlinks to udevadm for the debugging tools: udevmonitor and
393 udevtest are no longer created.
395 The symlinks to the udevadm man page for the old tool names are
398 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
399 should be prefixed with '@' to indicate that the path is not a
410 Udevstart is removed from the tree, it did not get installed for
411 a long time now, and is long replaced by trigger and settle.
417 All udev tools are merged into a single binary called udevadm.
418 The old names of the tools are built-in commands in udevadm now.
419 Symlinks to udevadm, with the names of the old tools, provide
420 the same functionality as the standalone tools. There is also
421 only a single udevadm.8 man page left for all tools.
423 Tools like mkinitramfs should be checked, if they need to include
424 udevadm in the list of files.
434 The etc/udev/rules.d/ directory now contains a default set of basic
435 udev rules. This initial version is the result of a rules file merge
436 of Fedora and openSUSE. For these both distros only a few specific
437 rules are left in their own file, named after the distro. Rules which
438 are optionally installed, because they are only valid for a specific
439 architecture, or rules for subsystems which are not always used are
440 in etc/udev/packages/.
446 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
447 actions by dynamically created rules.
449 SYMLINK=="<value>" matches agains the entries in the list of
450 currently defined symlinks. The links are not created in the
451 filesystem at that point in time, but the values can be matched.
453 RUN{ignore_error}+="<program>" will ignore any exit code from the
454 program and not record as a failed event.
460 Final merge of patches/features from the Ubuntu package.
466 Control characters in filesystem label strings are no longer silenty
467 removed, but hex-encoded, to be able to uniquely identify the device
468 by its symlink in /dev/disk/by-label/.
469 If libvolume_id is used by mount(8), LABEL= will work as expected,
470 if slashes or other characters are used in the label string.
472 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
473 can be specified now. The TEST key accepts an optional mode mask
474 TEST{0100}=="<is executable file>".
476 Scsi_id now supports a mode without expecting scsi-specific sysfs
477 entries to allow the extraction of cciss-device persistent properties.
483 In the future, we may see uuid's which are just simple character
484 strings (see the DDF Raid Specification). For that reason vol_id now
485 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
486 the creation of symlinks, the *_SAFE values ensure, that no control
487 or whitespace characters are used in the filename.
489 Possible users of libvolume_id, please use the volume_id_get_* functions.
490 The public struct will go away in a future release of the library.
496 Removal of useless extras/eventrecorder.sh.
506 The directory multiplexer for dev.d/ and hotplug.d are finally removed
507 from the udev package.
513 Symlinks can have priorities now, the priority is assigned to the device
514 and specified with OPTIONS="link_priority=100". Devices with higher
515 priorities overwrite the symlinks of devices with lower priorities.
516 If the device that currently owns the link, goes away, the symlink
517 will be removed, and recreated, pointing to the next device with the
518 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
519 more reliable, if multiple devices contain the same metadata and overwrite
522 The dasd_id program is removed from the udev tree, and dasdinfo, with the
523 needed rules, are part of the s390-tools now.
525 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
526 we may get the scsi sysfs mess fixed some day, and this will only catch
527 the devices we are looking for.
529 USB serial numbers for storage devices have the target:lun now appended,
530 to make it possibble to distinguish broken multi-lun devices with all
531 the same SCSI identifiers.
533 Note: The extra "run_directory" which searches and executes stuff in
534 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
535 with the next release. Make sure, that you don't use it anymore, or
536 provides your own implementation of that inefficient stuff.
537 We are tired of reports about a "slow udev", because these directories
538 contain stuff, that runs with _every_ event, instead of using rules,
539 that run programs only for the matching events.
549 DRIVER== will match only for devices that actually have a real
550 driver. DRIVERS== must be used, if parent devices should be
551 included in the match.
553 Libvolume_id's "linux_raid" detection needed another fix.
561 Add additional check to volume_id detection of via_raid, cause
562 some company decided to put a matching pattern all over the empty
563 storage area of their music players.
567 Fix path_id for SAS devices.
571 The udev daemon can be started with --debug-trace now, which will
572 execute all events serialized to get a chance to catch a possible
573 action that crashes the box.
575 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
576 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
577 are excluded from the warning. Referencing parent attributes directly
578 may break when something in the kernel driver model changes. Udev will
579 just find the attribute by walking up the parent chain.
581 Udevtrigger now sorts the list of devices depending on the device
582 dependency, so a "usb" device is triggered after the parent "pci"
587 Revert persistent-storage ata-serial '_' '-' replacement.
593 Udevtrigger can now filter the list of devices to be triggered. Matches
594 for subsystems or sysfs attributes can be specified.
596 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
597 zero-sized files to avoid pointing to /sys and confuse broken tools which
598 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
601 The rules and scripts to create udev rules for persistent network
602 devices and optical drives are in the extras/rules_generator directory
603 now. If you use something similar, please consider replacing your own
604 version with this, to share the support effort. The rule_generator
605 installs its own rules into /etc/udev/rules.d.
607 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
608 the rule_generator depends on cdrom_id to be called in an earlier rule.
614 Renaming of some key names (the old names still work):
615 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
616 (The behavior of the key DRIVER will change soon in one of the next
617 releases, to match only the event device, please switch to DRIVERS
618 instead. If DRIVER is used, it will behave like DRIVERS, but an error
620 With the new key names, we have a more consistent and simpler scheme.
621 We can match the properties of the event device only, with: KERNEL,
622 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
623 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
624 longer mentioned in the man page and should be switched in the rule
627 ATTR{file}="value" can be used now, to write to a sysfs file of the
628 event device. Instead of:
629 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
631 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
633 All the PHYSDEV* keys are deprecated and will be removed from a
635 PHYDEVPATH - is the path of a parent device and should not be
637 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
638 matched with SUBSYSTEMS==
639 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
640 Newer kernels will have DRIVER in the environment,
641 for older kernels udev puts in. Class device will
642 no longer carry this property of a parent and
643 DRIVERS== can be used to match such a parent value.
644 Note that ENV{DRIVER} is only available for a few bus devices, where
645 the driver is already bound at device event time. On coldplug, the
646 events for a lot devices are already bound to a driver, and they will have
647 that value set. But on hotplug, at the time the kernel creates the device,
648 it can't know what driver may claim the device after that, therefore
649 in most cases it will be empty.
651 Failed events should now be re-triggered with:
652 udevtrigger --retry-failed.
653 Please switch to this command, so we keep the details of the /dev/.udev/failed/
654 files private to the udev tools. We may need to switch the current symlink
655 target, cause some obviously broken tools try to scan all files in /dev
656 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
657 million times. This takes ages on slow boxes.
659 The udevinfo attribute walk (-a) now works with giving a device node
660 name (-n) instead of a devpath (-p). The query now always works, also when
661 no database file was created by udev.
663 The built-in /etc/passwd /etc/group parser is removed, we always depend on
664 getpwnam() and getgrnam() now. One of the next releases will depend on
665 fnmatch() and may use getopt_long().
669 Bugfixes and small improvements.
673 Fix path_id for recent kernels.
679 Added support for swapping network interface names, by temporarily
680 renaming the device and wait for the target name to become free.
684 The built-in MODALIAS key and substitution is removed.
688 The binary firmware helper is replaced by the usual simple
689 shell script. Udevsend is removed from the tree.
697 Some more keys require the correct use of '==' and '=' depending
698 on the kind of operation beeing an assignment or a match. Rules
699 with invalid operations are skipped and logged to syslog. Please
700 test with udevtest if the parsing of your rules throws errors and
701 fix possibly broken rules.
705 Provide "udevsettle" to wait for all current udev events to finish.
706 It also watches the current kernel netlink queue by comparing the
707 even sequence number to make sure that there are no current pending
708 events that have not already arrived in the daemon.
712 Fix rule to skip persistent rules for removable IDE devices, which
713 also skipped optical IDE drives.
715 All *_id program are installed in /lib/udev/ by default now.
717 No binary is stripped anymore as this should be done in the
718 packaging process and not at build time.
720 libvolume_id is provided as a shared library now and vol_id is
721 linked against it. Also one of the next HAL versions will require
722 this library, and the HAL build process will also require the
723 header file to be installed. The copy of the same code in HAL will
724 be removed to have only a single copy left on the system.
728 Add persistent links for SCSI tapes. The rules file is renamed
729 to 60-persistent-storage.rules.
731 Create persistent path for usb devices. Can be used for all sorts
732 of devices that can't be distinguished by other properties like
733 multiple identical keyboards and mice connected to the same box.
735 Provide "udevtrigger" program to request events on coldplug. The
736 shell script is much too slow with thousends of devices.
740 Fix persistent disk rules to exclude removable IDE drives.
742 Warn if %e, $modalias or MODALIAS is used.
746 Fix queue export, which wasn't correct for subsequent add/remove
747 events for the same device.
751 Fix cramfs detection on big endian.
753 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
758 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
759 attributes were only checked at the parent device that matched the
760 by BUS requested subsystem. Fix it to also look at the device we
761 received the event for.
763 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
768 Fix a bug where NAME="" would prevent RUN from beeing executed.
770 RUN="/bin/program" does not longer automatically add the subsystem
771 as the first parameter. This is from the days of /sbin/hotplug
772 which is dead now and it's just confusing to need to add a space at
773 the end of the program name to prevent this.
774 If you use rules that need the subsystem as the first parameter,
775 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
776 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
780 The udev man page has moved to udev(7) as it does not describe a command
781 anymore. The programs udev, udevstart and udevsend are no longer installed
782 by default and must be copied manually, if they should be installed or
783 included in a package.
785 Fix a bug where "ignore_device" could run earlier collected RUN keys before
786 the ignore rule was applied.
788 More preparation for future sysfs changes. usb_id and scsi_id no longer
789 depend on a magic order of devices in the /devices chain. Specific devices
790 should be requested by their subsytem.
792 This will always find the scsi parent device without depending on a specific
794 dev = sysfs_device_get(devpath);
795 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
797 The "device" link in the current sysfs layout will be automatically
798 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
799 parent in the devpath. If a device is requested by it's symlink, like all
800 class devices in the new sysfs layout will look like, it gets automatically
801 resolved and substituted with the real devpath and not the symlink path.
804 A similar logic must be applied to _all_ sysfs users, including
805 scripts, that search along parent devices in sysfs. The explicit use of
806 the "device" link must be avoided. With the future sysfs layout all
807 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
808 back to the "class" or the "bus". The layout of the parent devices in
809 /devices is not necessarily expected to be stable across kernel releases and
810 searching for parents by their subsystem should make sysfs users tolerant
811 for changed parent chains.
815 Prepare udev to work with the experimental kernel patch, that moves
816 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
818 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
819 moving the class devices to /sys/devices.
821 Thanks again to Marco for help finding a hopefully nice compromise
822 to make %b simpler and working again.
826 Complete removal of libsysfs, replaced by simple helper functions
827 which are much simpler and a bit faster. The udev daemon operatesentirely
828 on event parameters and does not use sysfs for simple rules anymore.
829 Please report any new bugs/problems, that may be caused by this big
830 change. They will be fixed immediately.
832 The enumeration format character '%e' is deprecated and will be
833 removed sometimes from a future udev version. It never worked correctly
834 outside of udevstart, so we can't use it with the new parallel
835 coldplug. A simple enumeration is as useless as the devfs naming
836 scheme, just get rid of both if you still use it.
838 MODALIAS and $modalias is not needed and will be removed from one of
839 the next udev versions, replace it in all rules with ENV{MODALIAS} or
840 the sysfs "modalias" value.
842 Thanks a lot to Marco for all his help on finding and fixing bugs.
846 Let scsi_id request libata drive serial numbers from page 0x80.
848 Renamed etc/udev/persistent.rules to persistent-disk.rules and
849 added /dev/disk/by-name/* for device mapper device names.
851 Removed %e from the man page. It never worked reliably outside
852 of udevstart and udevstart is no longer recommended to use.
856 Symlinks are now exported to the event environment. Hopefully it's no
857 longer needed to run udevinfo from an event process, like it was
858 mentioned on the hotplug list:
859 UDEV [1134776873.702967] add@/block/sdb
862 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
866 Fix a problem if udevsend is used as the hotplug handler and tries to use
867 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
868 and this kind of problems will hopefully go away soon.
872 All built-in logic to work around bad sysfs timing is removed with this
873 version. The need to wait for sysfs files is almost fixed with a kernel
874 version that doesn't work with this udev version anyway. Until we fix
875 the timing of the "bus" link creation, the former integrated logic should
876 be emulated by a rule placed before all other rules:
877 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
879 The option "udev_db" does no longer exist. All udev state will be in
880 /$udev_root/.udev/ now, there is no longer an option to set this
882 If the init script or something else used this value, just depend on
883 this hardcoded path. But remember _all_content_ of this directory is
884 still private to udev and can change at any time.
886 Default location for rule sripts and helper programs is now: /lib/udev/.
887 Everything that is not useful on the commandline should go into this
888 directory. Some of the helpers in the extras folder are installed there
889 now. The rules need to be changed, to find the helpers there.
891 Also /lib/udev/devices is recommended as a directory where packages or
892 the user can place real device nodes, which get copied over to /dev at
893 every boot. This should replace the various solutions with custom config
896 Udevsend does no longer start the udev daemon. This must be done with
897 the init script that prepares /dev on tmpfs and creates the initial nodes,
898 before starting the daemon.
902 Silent a too verbose error logging for the old hotplug.d/ dev.d/
905 The copy of klibc is removed. A systemwide installed version of klibc
906 should be used to build a klibc udev now.
910 NAME="" will not create any nodes, but execute RUN keys. To completely
911 ignore an event the OPTION "ignore_device" should be used.
913 After removal of the reorder queue, events with a TIMEOUT can be executed
914 without any queuing now.
918 Fixed bug in udevd, if inotify is not available. We depend on netlink
919 uevents now, kernels without that event source will not work with that
920 version of udev anymore.
924 The rule parsing happens now in the daemon once at startup, all udev
925 event processes inherit the already parsed rules from the daemon.
926 It is shipped with SUSE10.0 and reduces heavily the system load at
927 startup. The option to save precompiled rules and let the udev process
928 pick the them up is removed, as it's no longer needed.
930 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
931 device. Libsysfs is changed to "translate" the requested link into the
932 real device path, as it would happen with the hotplug event. Otherwise
933 device removal and the udev database will not work.
935 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
938 A few improvements for vol_id, the filesytem probing code.
942 Fix a stupid typo in extras/run_directory for "make install".
944 scsi_id creates the temporary devnode now in /dev for usage with a
945 non-writable /tmp directory.
947 The uevent kernel socket buffer can carry app. 50.000 events now,
948 let's see who can break this again. :)
950 The upcoming kernel will have a new input driver core integration.
951 Some class devices are now symlinks to the real device. libsysfs
952 needs a fix for this to work correctly. Udevstart of older udev
953 versions will _not_ create these devices!
957 Fix a 'install' target in the Makefile, that prevents EXTRAS from
962 A bunch of mostly trivial bugfixes. From now on no node name or
963 symlink name can contain any character than plain whitelisted ascii
964 characters or validated utf8 byte-streams. This is needed for the
965 /dev/disk/by-label/* links, because we import untrusted data and
966 export it to the filesystem.
970 More bugfixes. If udevd was started from the kernel, we don't
971 have stdin/stdout/stderr, which broke the forked tools in some
976 Bugfix. udevstart event ordering was broken for a long time.
977 The new run_program() uncovered it, because /dev/null was not
978 available while we try to run external programs.
979 Now udevstart should create it before we run anything.
983 Minor bugfixes and some distro rules updates. If you don't have the
984 persistent disk rules in /dev/disk/by-*/* on your distro, just
985 grab it from here. :)
989 We can use socket communication now to pass events from udev to
991 RUN+="socket:/org/freedesktop/hal/udev_event"
992 will pass the whole udev event to the HAL daemon without the need
993 for a forked helper. (See ChangeLog for udevmonitor, as an example)
997 Mostly bugfixes and see ChangeLog.
999 The test for the existence of an environment value should be
1001 ENV{KEY}=="*" to ENV{KEY}=="?*"
1002 because "*" will not fail anymore, if the key does not exist or
1007 Bugfixes and a few tweaks described in the ChangeLog.
1011 Mostly a Bugfix release.
1013 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1014 timing with custom rules.
1018 We changed the internal rule storage format. Our large rule files took
1019 2 MB of RAM, with the change we are down to 99kB.
1021 If the device-node has been created with default name and no symlink or
1022 options are to remenber, it is not longer stored in the udevdb. HAL will
1023 need to be updated to work correctly with that change.
1025 To overrride optimization flags, OPTFLAGS may be used now.
1033 Major changes happened with this release. The goal is to take over the
1034 complete kernel-event handling and provide a more efficient way to dispatch
1035 kernel events. Replacing most of the current shell script logic and the
1036 kernel forked helper with a netlink-daemon and a rule-based event handling.
1038 o udevd listens to netlink events now. The first valid netlink event
1039 will make udevd ignore any message from udevsend that contains a
1040 SEQNUM, to avoid duplicate events. The forked events can be disabled
1042 echo "" > /proc/sys/kernel/hotplug
1043 For full support, the broken input-subsytem needs to be fixed, not to
1044 bypass the driver core.
1046 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1047 removed from udev itself and must be emulated by calling small
1048 helper binaries provided in the extras folder:
1049 make EXTRAS=extras/run_directory/
1050 will build udev_run_devd and udev_run_hotplugd, which can be called
1051 from a rule if needed:
1052 RUN+="/sbin/udev_run_hotplugd"
1053 The recommended way to handle this is to convert all the calls from
1054 the directories to explicit udev rules and get completely rid of the
1055 multiplexing. (To catch a ttyUSB event, you now no longer need to
1056 fork and exit 300 tty script instances you are not interested in, it
1057 is just one rule that matches exactly the device.)
1059 o udev handles now _all_ events not just events for class and block
1060 devices, this way it is possible to control the complete event
1061 behavior with udev rules. Especially useful for rules like:
1062 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1064 o As used in the modalias rule, udev supports now textual
1065 substitution placeholder along with the usual format chars. This
1066 needs to be documented, for now it's only visible in udev_rules_parse.c.
1068 o The rule keys support now more operations. This is documented in the
1069 man page. It is possible to add values to list-keys like the SYMLINK
1070 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1071 Also "final"-assignments are supported by using KEY:="value", which will
1072 prevent changing the key by any later rule.
1074 o kernel 2.6.12 has the "detached_state" attribute removed from
1075 sysfs, which was used to recognize sysfs population. We switched that
1076 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1077 Running this udev version on older kernels may cause a short delay for
1080 o To provide infrastructure for persistent device naming, the id programs:
1081 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1082 to export the probed data in environment key format:
1083 pim:~ # /sbin/ata_id --export /dev/hda
1084 ID_MODEL=HTS726060M9AT00
1085 ID_SERIAL=MRH401M4G6UM9B
1086 ID_REVISION=MH4OA6BA
1088 The following rules:
1089 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1090 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1093 kay@pim:~> tree /dev/disk
1096 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1097 | `-- IBM-Memory_Key -> ../../sda
1099 | |-- swap -> ../../hda1
1100 | |-- date -> ../../sda1
1101 | `-- home -> ../../hda3
1103 |-- 2E08712B0870F2E7 -> ../../hda3
1104 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1105 |-- E845-7A89 -> ../../sda1
1106 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1108 The IMPORT= operation will import these keys in the environment and make
1109 it available for later PROGRAM= and RUN= executed programs. The keys are
1110 also stored in the udevdb and can be queried from there with one of the
1113 o A few binaries are silently added to the repository, which can be used
1114 to replay kernel events from initramfs instead of using coldplug. udevd
1115 can be instructed now to queue-up events while the stored events from
1116 initramfs are filled into the udevd-queue. This code is still under
1117 development and there is no documentation now besides the code itself.
1118 The additional binaries get compiled, but are not installed by default.
1120 o There is also a temporary fix for a performance problem where too many
1121 events happen in parallel and every event needs to parse the rules.
1122 udev can now read precompiled rules stored on disk. This is likely to be
1123 replaced by a more elegant solution in a future udev version.
1127 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1128 Fix for libsysfs not to expect this file was added.
1132 All rules are applied now, but only the first matching rule with a NAME-key
1133 will be applied. All later rules with NAME-key are completely ignored. This
1134 way system supplied symlinks or permissions gets applied to user-defined
1138 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1139 to some rules, to keep the old behavior.
1141 The rules are read on "remove"-events too. That makes is possible to match
1142 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1143 instruct udev to ignore an event (OPTIONS="ignore_device").
1144 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1146 The new RUN-key supports rule-based execution of programs after device-node
1147 handling. This is meant as a general replacement for the dev.d/-directories
1148 to give fine grained control over the execution of programs.
1150 The %s{}-sysfs format char replacement values are searched at any of the
1151 devices in the device chain now, not only at the class-device.
1153 We support log priority levels now. The value udev_log in udev.conf is used
1154 to determine what is printed to syslog. This makes it possible to
1155 run a version with compiled-in debug messages in a production environment
1156 which is sometimes needed to find a bug.
1157 It is still possible to supress the inclusion of _any_ syslog usage with
1158 USE_LOG=false to create the smallest possible binaries if needed.
1159 The configured udev_log value can be overridden with the environment variable
1164 Possible use of a system-wide klibc:
1165 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1166 will link against an external klibc and our own version will be ignored.
1170 We support an unlimited count of symlinks now.
1172 If USE_STATIC=true is passed to a glibc build, we link statically and use
1173 a built-in userdb parser to resolve user and group names.
1175 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1176 we walk up the chain of physical devices to find a match.
1178 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1179 easy to skip certain attribute matches without composing rules with weird
1180 character class negations like:
1181 KERNEL="[!s][!c][!d]*"
1182 this can now be replaced with:
1184 The current simple '=' is still supported, and should work as it does today,
1185 but existing rules should be converted if possible, to be better readable.
1187 We have new ENV{}== key now, to match against a maximum of 5 environment
1190 udevstart is its own binary again, because we don't need co carry this araound
1191 with every forked event.