3 Fix possible crash in udevd when worker processes are busy, rules are
4 changed at the same time, and workers get killed to reload the rules.
10 Properties set with ENV{.FOO}="bar" are marked private by starting the
11 name with a '.'. They will not be stored in the database, and not be
12 exported with the event.
14 Firmware files are looked up in:
15 /lib/firmware/updates/$(uname -r)
17 /lib/firmware/$(uname -r)
21 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
22 ata_id, instead of scsi_id, is the default tool now for ATA devices.
28 The configure options have changed because another library needs to be
29 installed in a different location. Instead of exec_prefix and udev_prefix,
30 libdir, rootlibdir and libexecdir are used. The Details are explained in
33 Event processes now get re-used after they handled an event. This reduces
34 the number of forks and the pressure on the CPU significantly, because
35 cloned event processes no longer cause page faults in the main daemon.
36 After the events have settled, a few worker processes stay around for
37 future events, all others get cleaned up.
39 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
40 Also inotify support is mandatory now to run udev.
42 The format of the queue exported by the udev damon has changed. There is
43 no longer a /dev/.udev/queue/ directory. The current event queue can be
44 accessed with udevadm settle and libudedv.
46 Libudev does not have the unstable API header anymore. From now on,
47 incompatible changes will be handled by bumping the library major version.
49 To build udev from the git tree gtk-doc is needed now. The tarballs will
50 build without it and contain the pre-built documentation. An online copy
52 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
54 The tools from the udev-extras repository have been merged into the main
55 udev repository. Some of the extras have larger external dependencies, and
56 they can be disabled with the configure switch --disable-extras.
62 The program vol_id and the library libvolume_id are removed from the
63 repository. Libvolume_id is merged with libblkid from the util-linux-ng
64 package. Persistent disk links for label and uuid depend on the
65 util-linux-ng version (2.15) of blkid now. Older versions of blkid
66 can not be used with udev.
68 Libudev allows to subscribe to udev events. To prevent unwanted messages
69 to be delivered, and waking up the subscribing process, a filter can be
70 installed, to drop messages inside a kernel socket filter. The filters
71 match on the <subsytem>:<devtype> properties of the device.
72 This is part of the ongoing effort to replace HAL, and switch current
73 users over to directly use libudev.
74 Libudev is still marked as experimental, and its interface might
75 eventually change if needed, but no major changes of the currently exported
76 interface are expected anymore, and a first stable release should happen
79 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
80 is not supported since while and udevd will log an error message at
81 startup. It should still be able to boot-up, but advanced rules and system
82 services which depend on the information not available in the old sysfs
83 format will fail to work correctly.
85 DVB device naming is supplied by the kernel now. In case older kernels
86 need to be supported, the old shell script should be added to a compat
93 The processed udev events get send back to the netlink socket. Libudev
94 provides access to these events. This is work-in-progress, to replace
95 the DeviceKit daemon functionality directly with libudev. There are
96 upcoming kernel changes to allow non-root users to subcribe to these
103 "udevadm settle" now optionally accepts a range of events to wait for,
104 instead of waiting for "all" events.
110 The installed watch for block device metadata changes is now removed
111 during event hadling, because some (broken) tools may be called from udev
112 rules and (wrongly) open the device with write access. After the finished
113 event handling the watch is restored.
119 Device nodes can be watched for changes with inotify with OPTIONS="watch".
120 If closed after being opened for writing, a "change" uevent will occur.
121 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
127 The udevadm test command has no longer a --force option, nodes and symlinks
128 are always updated with a test run now.
130 The udevd daemon can be started with --resolve-names=never to avoid all user
131 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
132 lookup user and groups every time events are handled.
138 We are currently merging the Ubuntu rules in the udev default rules,
139 and get one step closer to provide a common Linux /dev setup, regarding
140 device names, symlinks, and default device permissions. On udev startup,
141 we now expect the following groups to be resolvable to their ids with
143 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
144 LDAP setups need to make sure, that these groups are always resolvable at
145 bootup, with only the rootfs mounted, and without network access available.
147 Some systems may need to add some new, currently not used groups, or need
148 to add some users to new groups, but the cost of this change is minimal,
149 compared to the pain the current, rather random, differences between the
150 various distributions cause for upstream projects and third-party vendors.
152 In general, "normal" users who log into a machine should never be a member
153 of any such group, but the device-access should be managed by dynamic ACLs,
154 which get added and removed for the specific users on login/logout and
155 session activity/inactivity. These groups are only provided for custom setups,
156 and mainly system services, to allow proper privilege separation.
157 A video-streaming daemon uid would be a member of "audio" and "video", to get
158 access to the sound and video devices, but no "normal" user should ever belong
159 to the "audio" group, because he could listen to the built-in microphone with
160 any ssh-session established from the other side of the world.
162 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
163 which do not depend on the kernel device name. As usual, unique
164 devices - only a single one per product connected, or a real
165 USB serial number in the device - are always found with the same
166 name in the by-id/ directory.
167 Completely identical devices may overwrite their names in by-id/
168 and can only be found reliably in the by-path/ directory. Devices
169 specified by by-path/ must not change their connection, like the
170 USB port number they are plugged in, to keep their name.
172 To support some advanced features, Linux 2.6.22 is the oldest supported
173 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
174 supported. Older kernels should still work, and devices nodes should be
175 reliably created, but some rules and libudev will not work correctly because
176 the old kernels do not provide the expected information or interfaces.
182 Fix for a possible segfault while swapping network interface names in udev
189 The group "video" is part of the default rules now.
193 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
194 block devices in some cases. No common distro uses this option anymore,
195 and we do not get enough testing for this and recent udev versions. If
196 this option is not needed to run some old distro with a new kernel,
197 it should be disabled in the kernel config.
199 Bugfix for the $links substitution variable, which may crash if no links
200 are created. This should not happen in usual setups because we always
201 create /dev/{block,char}/ links.
203 The strings of the parsed rules, which are kept in memory, no longer
204 contain duplicate entries, or duplicate tails of strings. This, and the
205 new rules parsing/matching code reduces the total in-memory size of
206 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
209 The export of DEVTYPE=disk/partition got removed from the default
210 rules. This value is available from the kernel. The pnp shell script
211 modprobe hack is removed from the default rules. ACPI devices have _proper_
212 modalias support and take care of the same functionality.
213 Installations which support old kernels, but install current default
214 udev rules may want to add that to the compat rules file.
216 Libvolume_id now always probes for all known filesystems, and does not
217 stop at the first match. Some filesystems are marked as "exclusive probe",
218 and if any other filesytem type matches at the same time, libvolume_id
219 will, by default, not return any probing result. This is intended to prevent
220 mis-detection with conflicting left-over signatures found from earlier
221 file system formats. That way, we no longer depend on the probe-order
222 in case of multiple competing signatures. In some setups the kernel allows
223 to mount a volume with just the old filesystem signature still in place.
224 This may damage the new filesystem and cause data-loss, just by mounting
225 it. Because volume_id can not decide which one the correct signature is,
226 the wrong signatures need to be removed manually from the volume, or the
227 volume needs to be reformatted, to enable filesystem detection and possible
232 Fix segfault if compiled without optimization and dbg() does not get
233 compiled out and uses variables which are not available.
237 Bugfixes. (And maybe new bugs. :))
239 The rule matching engine got converted from a rule list to a token
240 array which reduced the in-memory rules representation of a full
241 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
242 Limits like 5 ENV and ATTR matches, and one single instance for most
243 other keys per rule are gone.
245 The NAME assignment is no longer special cased. If later rules assign
246 a NAME value again, the former value will be overwritten. As usual
247 for most other keys, the NAME value can be protected by doing a final
248 assignment with NAME:="<value>".
250 All udev code now uses libudev, which is also exported. The library
251 is still under development, marked as experimental, and its interface
252 may change as long as the DeviceKit integration is not finished.
254 Many thanks to Alan Jenkins for his continuous help, and finding and
255 optimizing some of the computing expensive parts.
261 Kernel devices and device nodes are connected now by reverse indizes in
262 /sys and /dev. A device number retrieved by a stat() or similar, the
263 kernel device directory can be found by looking up:
264 /sys/dev/{block,char}/<maj>:<min>
265 and the device node of the same device by looking up:
266 /dev/{block,char}/<maj>:<min>
270 Fix recently introduced bug, which caused a compilation without large
271 file support, where vol_id does not recognize raid signatures at the end
274 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
275 Seems some kernel versions prevent the creation of the ieee-* links,
276 so people used the scsi-* link which disappeared now.
278 More libudev work. Almost all udevadm functionality comes from libudev
281 udevadm trigger has a new option --type, which allows to trigger events
282 for "devices", for "subsystems", or "failed" devices. The old option
283 --retry-failed" still works, but is no longer mentioned in the man page.
289 The udevadm info --device-id-of-file= output has changed to use
290 the obvious format. Possible current users should use the --export
291 option which is not affected.
293 The old udev commands symlinks to udevadm are not installed, if
294 these symlinks are used, a warning is printed.
300 Optical drive's media is no longer probed for raid signatures,
301 reading the end of the device causes some devices to malfunction.
302 Also the offset of the last session found is used now to probe
305 The volume_id library got a major version number update to 1,
306 some deprecated functions are removed.
308 A shared library "libudev" gets installed now to provide access
309 to udev device information. DeviceKit, the successor of HAL, will
310 need this library to access the udev database and search sysfs for
312 The library is currently in an experimental state, also the API is
313 expected to change, as long as the DeviceKit integration is not
318 We use ./configure now. See INSTALL for details. Current
321 "/usr" - prefix for man pages, include files
323 "" - the root filesystem, prefix for libs and binaries
327 "lib" - directory name for libraries, not a path name
328 multilib 64bit systems may use "lib64" instead of "lib"
330 compile-in verbose debug messages
332 disable all logging and compile-out all log strings
334 link against SELInux libraries, to set the expected context
337 In the default rules, the group "disk" gets permissions 0660 instead
338 of 0640. One small step closer to unify distro rules. Some day, all
339 distros hopefully end up with the same set of rules.
341 No symlinks to udevadm are installed anymore, if they are still needed,
342 they should be provided by the package.
348 Default udev rules, which are not supposed to be edited by the user, should
349 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
350 the udev package and will be replaced with an update. Udev will pick up rule
352 /lib/udev/rules.d/ - default installed rules
353 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
354 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
355 It does not matter in which directory a rule file lives, all files are sorted
358 To help creating /dev/root, we have now:
359 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
362 In case the current --device-id-of-file is already used, please switch to
363 the --export format version, it saves the output parsing and the old
364 format will be changed to use ':' as a separator, like the format in the
369 Fix cdrom_id to properly recognize blank media.
375 Tape drive id-data is queried from /dev/bsg/* instead of the tape
376 nodes. This avoids rewinding tapes on open().
382 The symlinks udevcontrol and udevtrigger are no longer installed by
385 The scsi_id program does not depend on sysfs anymore. It can speak
386 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
387 data, which should solve some old problems with tape devices, where
388 we better do not open all tape device nodes to identify the device.
394 The cdrom_id program is replaced by an advanced version, which can
395 detect most common device types, and also properties of the inserted
396 media. This is part of moving some basic functionality from HAL into
397 udev (and the kernel).
403 The last WAIT_FOR_SYSFS rule is removed from the default rules.
405 The symlinks to udevadm for the debugging tools: udevmonitor and
406 udevtest are no longer created.
408 The symlinks to the udevadm man page for the old tool names are
411 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
412 should be prefixed with '@' to indicate that the path is not a
423 Udevstart is removed from the tree, it did not get installed for
424 a long time now, and is long replaced by trigger and settle.
430 All udev tools are merged into a single binary called udevadm.
431 The old names of the tools are built-in commands in udevadm now.
432 Symlinks to udevadm, with the names of the old tools, provide
433 the same functionality as the standalone tools. There is also
434 only a single udevadm.8 man page left for all tools.
436 Tools like mkinitramfs should be checked, if they need to include
437 udevadm in the list of files.
447 The etc/udev/rules.d/ directory now contains a default set of basic
448 udev rules. This initial version is the result of a rules file merge
449 of Fedora and openSUSE. For these both distros only a few specific
450 rules are left in their own file, named after the distro. Rules which
451 are optionally installed, because they are only valid for a specific
452 architecture, or rules for subsystems which are not always used are
453 in etc/udev/packages/.
459 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
460 actions by dynamically created rules.
462 SYMLINK=="<value>" matches agains the entries in the list of
463 currently defined symlinks. The links are not created in the
464 filesystem at that point in time, but the values can be matched.
466 RUN{ignore_error}+="<program>" will ignore any exit code from the
467 program and not record as a failed event.
473 Final merge of patches/features from the Ubuntu package.
479 Control characters in filesystem label strings are no longer silenty
480 removed, but hex-encoded, to be able to uniquely identify the device
481 by its symlink in /dev/disk/by-label/.
482 If libvolume_id is used by mount(8), LABEL= will work as expected,
483 if slashes or other characters are used in the label string.
485 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
486 can be specified now. The TEST key accepts an optional mode mask
487 TEST{0100}=="<is executable file>".
489 Scsi_id now supports a mode without expecting scsi-specific sysfs
490 entries to allow the extraction of cciss-device persistent properties.
496 In the future, we may see uuid's which are just simple character
497 strings (see the DDF Raid Specification). For that reason vol_id now
498 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
499 the creation of symlinks, the *_SAFE values ensure, that no control
500 or whitespace characters are used in the filename.
502 Possible users of libvolume_id, please use the volume_id_get_* functions.
503 The public struct will go away in a future release of the library.
509 Removal of useless extras/eventrecorder.sh.
519 The directory multiplexer for dev.d/ and hotplug.d are finally removed
520 from the udev package.
526 Symlinks can have priorities now, the priority is assigned to the device
527 and specified with OPTIONS="link_priority=100". Devices with higher
528 priorities overwrite the symlinks of devices with lower priorities.
529 If the device that currently owns the link, goes away, the symlink
530 will be removed, and recreated, pointing to the next device with the
531 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
532 more reliable, if multiple devices contain the same metadata and overwrite
535 The dasd_id program is removed from the udev tree, and dasdinfo, with the
536 needed rules, are part of the s390-tools now.
538 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
539 we may get the scsi sysfs mess fixed some day, and this will only catch
540 the devices we are looking for.
542 USB serial numbers for storage devices have the target:lun now appended,
543 to make it possibble to distinguish broken multi-lun devices with all
544 the same SCSI identifiers.
546 Note: The extra "run_directory" which searches and executes stuff in
547 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
548 with the next release. Make sure, that you don't use it anymore, or
549 provides your own implementation of that inefficient stuff.
550 We are tired of reports about a "slow udev", because these directories
551 contain stuff, that runs with _every_ event, instead of using rules,
552 that run programs only for the matching events.
562 DRIVER== will match only for devices that actually have a real
563 driver. DRIVERS== must be used, if parent devices should be
564 included in the match.
566 Libvolume_id's "linux_raid" detection needed another fix.
574 Add additional check to volume_id detection of via_raid, cause
575 some company decided to put a matching pattern all over the empty
576 storage area of their music players.
580 Fix path_id for SAS devices.
584 The udev daemon can be started with --debug-trace now, which will
585 execute all events serialized to get a chance to catch a possible
586 action that crashes the box.
588 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
589 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
590 are excluded from the warning. Referencing parent attributes directly
591 may break when something in the kernel driver model changes. Udev will
592 just find the attribute by walking up the parent chain.
594 Udevtrigger now sorts the list of devices depending on the device
595 dependency, so a "usb" device is triggered after the parent "pci"
600 Revert persistent-storage ata-serial '_' '-' replacement.
606 Udevtrigger can now filter the list of devices to be triggered. Matches
607 for subsystems or sysfs attributes can be specified.
609 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
610 zero-sized files to avoid pointing to /sys and confuse broken tools which
611 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
614 The rules and scripts to create udev rules for persistent network
615 devices and optical drives are in the extras/rules_generator directory
616 now. If you use something similar, please consider replacing your own
617 version with this, to share the support effort. The rule_generator
618 installs its own rules into /etc/udev/rules.d.
620 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
621 the rule_generator depends on cdrom_id to be called in an earlier rule.
627 Renaming of some key names (the old names still work):
628 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
629 (The behavior of the key DRIVER will change soon in one of the next
630 releases, to match only the event device, please switch to DRIVERS
631 instead. If DRIVER is used, it will behave like DRIVERS, but an error
633 With the new key names, we have a more consistent and simpler scheme.
634 We can match the properties of the event device only, with: KERNEL,
635 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
636 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
637 longer mentioned in the man page and should be switched in the rule
640 ATTR{file}="value" can be used now, to write to a sysfs file of the
641 event device. Instead of:
642 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
644 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
646 All the PHYSDEV* keys are deprecated and will be removed from a
648 PHYDEVPATH - is the path of a parent device and should not be
650 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
651 matched with SUBSYSTEMS==
652 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
653 Newer kernels will have DRIVER in the environment,
654 for older kernels udev puts in. Class device will
655 no longer carry this property of a parent and
656 DRIVERS== can be used to match such a parent value.
657 Note that ENV{DRIVER} is only available for a few bus devices, where
658 the driver is already bound at device event time. On coldplug, the
659 events for a lot devices are already bound to a driver, and they will have
660 that value set. But on hotplug, at the time the kernel creates the device,
661 it can't know what driver may claim the device after that, therefore
662 in most cases it will be empty.
664 Failed events should now be re-triggered with:
665 udevtrigger --retry-failed.
666 Please switch to this command, so we keep the details of the /dev/.udev/failed/
667 files private to the udev tools. We may need to switch the current symlink
668 target, cause some obviously broken tools try to scan all files in /dev
669 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
670 million times. This takes ages on slow boxes.
672 The udevinfo attribute walk (-a) now works with giving a device node
673 name (-n) instead of a devpath (-p). The query now always works, also when
674 no database file was created by udev.
676 The built-in /etc/passwd /etc/group parser is removed, we always depend on
677 getpwnam() and getgrnam() now. One of the next releases will depend on
678 fnmatch() and may use getopt_long().
682 Bugfixes and small improvements.
686 Fix path_id for recent kernels.
692 Added support for swapping network interface names, by temporarily
693 renaming the device and wait for the target name to become free.
697 The built-in MODALIAS key and substitution is removed.
701 The binary firmware helper is replaced by the usual simple
702 shell script. Udevsend is removed from the tree.
710 Some more keys require the correct use of '==' and '=' depending
711 on the kind of operation beeing an assignment or a match. Rules
712 with invalid operations are skipped and logged to syslog. Please
713 test with udevtest if the parsing of your rules throws errors and
714 fix possibly broken rules.
718 Provide "udevsettle" to wait for all current udev events to finish.
719 It also watches the current kernel netlink queue by comparing the
720 even sequence number to make sure that there are no current pending
721 events that have not already arrived in the daemon.
725 Fix rule to skip persistent rules for removable IDE devices, which
726 also skipped optical IDE drives.
728 All *_id program are installed in /lib/udev/ by default now.
730 No binary is stripped anymore as this should be done in the
731 packaging process and not at build time.
733 libvolume_id is provided as a shared library now and vol_id is
734 linked against it. Also one of the next HAL versions will require
735 this library, and the HAL build process will also require the
736 header file to be installed. The copy of the same code in HAL will
737 be removed to have only a single copy left on the system.
741 Add persistent links for SCSI tapes. The rules file is renamed
742 to 60-persistent-storage.rules.
744 Create persistent path for usb devices. Can be used for all sorts
745 of devices that can't be distinguished by other properties like
746 multiple identical keyboards and mice connected to the same box.
748 Provide "udevtrigger" program to request events on coldplug. The
749 shell script is much too slow with thousends of devices.
753 Fix persistent disk rules to exclude removable IDE drives.
755 Warn if %e, $modalias or MODALIAS is used.
759 Fix queue export, which wasn't correct for subsequent add/remove
760 events for the same device.
764 Fix cramfs detection on big endian.
766 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
771 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
772 attributes were only checked at the parent device that matched the
773 by BUS requested subsystem. Fix it to also look at the device we
774 received the event for.
776 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
781 Fix a bug where NAME="" would prevent RUN from beeing executed.
783 RUN="/bin/program" does not longer automatically add the subsystem
784 as the first parameter. This is from the days of /sbin/hotplug
785 which is dead now and it's just confusing to need to add a space at
786 the end of the program name to prevent this.
787 If you use rules that need the subsystem as the first parameter,
788 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
789 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
793 The udev man page has moved to udev(7) as it does not describe a command
794 anymore. The programs udev, udevstart and udevsend are no longer installed
795 by default and must be copied manually, if they should be installed or
796 included in a package.
798 Fix a bug where "ignore_device" could run earlier collected RUN keys before
799 the ignore rule was applied.
801 More preparation for future sysfs changes. usb_id and scsi_id no longer
802 depend on a magic order of devices in the /devices chain. Specific devices
803 should be requested by their subsytem.
805 This will always find the scsi parent device without depending on a specific
807 dev = sysfs_device_get(devpath);
808 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
810 The "device" link in the current sysfs layout will be automatically
811 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
812 parent in the devpath. If a device is requested by it's symlink, like all
813 class devices in the new sysfs layout will look like, it gets automatically
814 resolved and substituted with the real devpath and not the symlink path.
817 A similar logic must be applied to _all_ sysfs users, including
818 scripts, that search along parent devices in sysfs. The explicit use of
819 the "device" link must be avoided. With the future sysfs layout all
820 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
821 back to the "class" or the "bus". The layout of the parent devices in
822 /devices is not necessarily expected to be stable across kernel releases and
823 searching for parents by their subsystem should make sysfs users tolerant
824 for changed parent chains.
828 Prepare udev to work with the experimental kernel patch, that moves
829 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
831 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
832 moving the class devices to /sys/devices.
834 Thanks again to Marco for help finding a hopefully nice compromise
835 to make %b simpler and working again.
839 Complete removal of libsysfs, replaced by simple helper functions
840 which are much simpler and a bit faster. The udev daemon operatesentirely
841 on event parameters and does not use sysfs for simple rules anymore.
842 Please report any new bugs/problems, that may be caused by this big
843 change. They will be fixed immediately.
845 The enumeration format character '%e' is deprecated and will be
846 removed sometimes from a future udev version. It never worked correctly
847 outside of udevstart, so we can't use it with the new parallel
848 coldplug. A simple enumeration is as useless as the devfs naming
849 scheme, just get rid of both if you still use it.
851 MODALIAS and $modalias is not needed and will be removed from one of
852 the next udev versions, replace it in all rules with ENV{MODALIAS} or
853 the sysfs "modalias" value.
855 Thanks a lot to Marco for all his help on finding and fixing bugs.
859 Let scsi_id request libata drive serial numbers from page 0x80.
861 Renamed etc/udev/persistent.rules to persistent-disk.rules and
862 added /dev/disk/by-name/* for device mapper device names.
864 Removed %e from the man page. It never worked reliably outside
865 of udevstart and udevstart is no longer recommended to use.
869 Symlinks are now exported to the event environment. Hopefully it's no
870 longer needed to run udevinfo from an event process, like it was
871 mentioned on the hotplug list:
872 UDEV [1134776873.702967] add@/block/sdb
875 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
879 Fix a problem if udevsend is used as the hotplug handler and tries to use
880 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
881 and this kind of problems will hopefully go away soon.
885 All built-in logic to work around bad sysfs timing is removed with this
886 version. The need to wait for sysfs files is almost fixed with a kernel
887 version that doesn't work with this udev version anyway. Until we fix
888 the timing of the "bus" link creation, the former integrated logic should
889 be emulated by a rule placed before all other rules:
890 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
892 The option "udev_db" does no longer exist. All udev state will be in
893 /$udev_root/.udev/ now, there is no longer an option to set this
895 If the init script or something else used this value, just depend on
896 this hardcoded path. But remember _all_content_ of this directory is
897 still private to udev and can change at any time.
899 Default location for rule sripts and helper programs is now: /lib/udev/.
900 Everything that is not useful on the commandline should go into this
901 directory. Some of the helpers in the extras folder are installed there
902 now. The rules need to be changed, to find the helpers there.
904 Also /lib/udev/devices is recommended as a directory where packages or
905 the user can place real device nodes, which get copied over to /dev at
906 every boot. This should replace the various solutions with custom config
909 Udevsend does no longer start the udev daemon. This must be done with
910 the init script that prepares /dev on tmpfs and creates the initial nodes,
911 before starting the daemon.
915 Silent a too verbose error logging for the old hotplug.d/ dev.d/
918 The copy of klibc is removed. A systemwide installed version of klibc
919 should be used to build a klibc udev now.
923 NAME="" will not create any nodes, but execute RUN keys. To completely
924 ignore an event the OPTION "ignore_device" should be used.
926 After removal of the reorder queue, events with a TIMEOUT can be executed
927 without any queuing now.
931 Fixed bug in udevd, if inotify is not available. We depend on netlink
932 uevents now, kernels without that event source will not work with that
933 version of udev anymore.
937 The rule parsing happens now in the daemon once at startup, all udev
938 event processes inherit the already parsed rules from the daemon.
939 It is shipped with SUSE10.0 and reduces heavily the system load at
940 startup. The option to save precompiled rules and let the udev process
941 pick the them up is removed, as it's no longer needed.
943 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
944 device. Libsysfs is changed to "translate" the requested link into the
945 real device path, as it would happen with the hotplug event. Otherwise
946 device removal and the udev database will not work.
948 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
951 A few improvements for vol_id, the filesytem probing code.
955 Fix a stupid typo in extras/run_directory for "make install".
957 scsi_id creates the temporary devnode now in /dev for usage with a
958 non-writable /tmp directory.
960 The uevent kernel socket buffer can carry app. 50.000 events now,
961 let's see who can break this again. :)
963 The upcoming kernel will have a new input driver core integration.
964 Some class devices are now symlinks to the real device. libsysfs
965 needs a fix for this to work correctly. Udevstart of older udev
966 versions will _not_ create these devices!
970 Fix a 'install' target in the Makefile, that prevents EXTRAS from
975 A bunch of mostly trivial bugfixes. From now on no node name or
976 symlink name can contain any character than plain whitelisted ascii
977 characters or validated utf8 byte-streams. This is needed for the
978 /dev/disk/by-label/* links, because we import untrusted data and
979 export it to the filesystem.
983 More bugfixes. If udevd was started from the kernel, we don't
984 have stdin/stdout/stderr, which broke the forked tools in some
989 Bugfix. udevstart event ordering was broken for a long time.
990 The new run_program() uncovered it, because /dev/null was not
991 available while we try to run external programs.
992 Now udevstart should create it before we run anything.
996 Minor bugfixes and some distro rules updates. If you don't have the
997 persistent disk rules in /dev/disk/by-*/* on your distro, just
998 grab it from here. :)
1002 We can use socket communication now to pass events from udev to
1004 RUN+="socket:/org/freedesktop/hal/udev_event"
1005 will pass the whole udev event to the HAL daemon without the need
1006 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1010 Mostly bugfixes and see ChangeLog.
1012 The test for the existence of an environment value should be
1014 ENV{KEY}=="*" to ENV{KEY}=="?*"
1015 because "*" will not fail anymore, if the key does not exist or
1020 Bugfixes and a few tweaks described in the ChangeLog.
1024 Mostly a Bugfix release.
1026 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1027 timing with custom rules.
1031 We changed the internal rule storage format. Our large rule files took
1032 2 MB of RAM, with the change we are down to 99kB.
1034 If the device-node has been created with default name and no symlink or
1035 options are to remenber, it is not longer stored in the udevdb. HAL will
1036 need to be updated to work correctly with that change.
1038 To overrride optimization flags, OPTFLAGS may be used now.
1046 Major changes happened with this release. The goal is to take over the
1047 complete kernel-event handling and provide a more efficient way to dispatch
1048 kernel events. Replacing most of the current shell script logic and the
1049 kernel forked helper with a netlink-daemon and a rule-based event handling.
1051 o udevd listens to netlink events now. The first valid netlink event
1052 will make udevd ignore any message from udevsend that contains a
1053 SEQNUM, to avoid duplicate events. The forked events can be disabled
1055 echo "" > /proc/sys/kernel/hotplug
1056 For full support, the broken input-subsytem needs to be fixed, not to
1057 bypass the driver core.
1059 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1060 removed from udev itself and must be emulated by calling small
1061 helper binaries provided in the extras folder:
1062 make EXTRAS=extras/run_directory/
1063 will build udev_run_devd and udev_run_hotplugd, which can be called
1064 from a rule if needed:
1065 RUN+="/sbin/udev_run_hotplugd"
1066 The recommended way to handle this is to convert all the calls from
1067 the directories to explicit udev rules and get completely rid of the
1068 multiplexing. (To catch a ttyUSB event, you now no longer need to
1069 fork and exit 300 tty script instances you are not interested in, it
1070 is just one rule that matches exactly the device.)
1072 o udev handles now _all_ events not just events for class and block
1073 devices, this way it is possible to control the complete event
1074 behavior with udev rules. Especially useful for rules like:
1075 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1077 o As used in the modalias rule, udev supports now textual
1078 substitution placeholder along with the usual format chars. This
1079 needs to be documented, for now it's only visible in udev_rules_parse.c.
1081 o The rule keys support now more operations. This is documented in the
1082 man page. It is possible to add values to list-keys like the SYMLINK
1083 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1084 Also "final"-assignments are supported by using KEY:="value", which will
1085 prevent changing the key by any later rule.
1087 o kernel 2.6.12 has the "detached_state" attribute removed from
1088 sysfs, which was used to recognize sysfs population. We switched that
1089 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1090 Running this udev version on older kernels may cause a short delay for
1093 o To provide infrastructure for persistent device naming, the id programs:
1094 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1095 to export the probed data in environment key format:
1096 pim:~ # /sbin/ata_id --export /dev/hda
1097 ID_MODEL=HTS726060M9AT00
1098 ID_SERIAL=MRH401M4G6UM9B
1099 ID_REVISION=MH4OA6BA
1101 The following rules:
1102 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1103 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1106 kay@pim:~> tree /dev/disk
1109 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1110 | `-- IBM-Memory_Key -> ../../sda
1112 | |-- swap -> ../../hda1
1113 | |-- date -> ../../sda1
1114 | `-- home -> ../../hda3
1116 |-- 2E08712B0870F2E7 -> ../../hda3
1117 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1118 |-- E845-7A89 -> ../../sda1
1119 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1121 The IMPORT= operation will import these keys in the environment and make
1122 it available for later PROGRAM= and RUN= executed programs. The keys are
1123 also stored in the udevdb and can be queried from there with one of the
1126 o A few binaries are silently added to the repository, which can be used
1127 to replay kernel events from initramfs instead of using coldplug. udevd
1128 can be instructed now to queue-up events while the stored events from
1129 initramfs are filled into the udevd-queue. This code is still under
1130 development and there is no documentation now besides the code itself.
1131 The additional binaries get compiled, but are not installed by default.
1133 o There is also a temporary fix for a performance problem where too many
1134 events happen in parallel and every event needs to parse the rules.
1135 udev can now read precompiled rules stored on disk. This is likely to be
1136 replaced by a more elegant solution in a future udev version.
1140 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1141 Fix for libsysfs not to expect this file was added.
1145 All rules are applied now, but only the first matching rule with a NAME-key
1146 will be applied. All later rules with NAME-key are completely ignored. This
1147 way system supplied symlinks or permissions gets applied to user-defined
1151 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1152 to some rules, to keep the old behavior.
1154 The rules are read on "remove"-events too. That makes is possible to match
1155 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1156 instruct udev to ignore an event (OPTIONS="ignore_device").
1157 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1159 The new RUN-key supports rule-based execution of programs after device-node
1160 handling. This is meant as a general replacement for the dev.d/-directories
1161 to give fine grained control over the execution of programs.
1163 The %s{}-sysfs format char replacement values are searched at any of the
1164 devices in the device chain now, not only at the class-device.
1166 We support log priority levels now. The value udev_log in udev.conf is used
1167 to determine what is printed to syslog. This makes it possible to
1168 run a version with compiled-in debug messages in a production environment
1169 which is sometimes needed to find a bug.
1170 It is still possible to supress the inclusion of _any_ syslog usage with
1171 USE_LOG=false to create the smallest possible binaries if needed.
1172 The configured udev_log value can be overridden with the environment variable
1177 Possible use of a system-wide klibc:
1178 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1179 will link against an external klibc and our own version will be ignored.
1183 We support an unlimited count of symlinks now.
1185 If USE_STATIC=true is passed to a glibc build, we link statically and use
1186 a built-in userdb parser to resolve user and group names.
1188 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1189 we walk up the chain of physical devices to find a match.
1191 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1192 easy to skip certain attribute matches without composing rules with weird
1193 character class negations like:
1194 KERNEL="[!s][!c][!d]*"
1195 this can now be replaced with:
1197 The current simple '=' is still supported, and should work as it does today,
1198 but existing rules should be converted if possible, to be better readable.
1200 We have new ENV{}== key now, to match against a maximum of 5 environment
1203 udevstart is its own binary again, because we don't need co carry this araound
1204 with every forked event.