5 The hid2hci tool move to the bluez package and was removed.
7 Many of the extras can be -enabled/--disabled during configure
8 now. The --disable-extras option was removed. To check the
9 current options, the usual './configure --help' prints them.
15 Udev logs a warning now if /run is not writable at udevd
16 startup. It will still fall back to /dev/.udev, but this is
19 The running udev daemon can now cleanly shut down with:
20 udevadm control --exit
22 Udev in initramfs should clean the state of the udev database
23 with: udevadm info --cleanup-db which will remove all state left
24 behind from events/rules in initramfs. If initramfs uses
25 --cleanup-db and device-mapper/LVM, the rules in initramfs need
26 to add OPTIONS+="db_persist" for all dm devices. This will
27 prevent removal of the udev database for these devices.
29 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
30 120 seconds per process. If that timeout is reached the spawned
31 process will be killed. The event timeout can be overwritten with
34 If systemd is used, udev gets now activated by netlink data.
35 Systemd will bind the netlink socket which will buffer all data.
36 If needed, such setup allows a seemless update of the udev daemon,
37 where no event can be lost during a udevd update/restart.
38 Packages need to make sure to: systemctl stop udev.socket udev.service
39 or 'mask' udev.service during the upgrade to prevent any unwanted
40 auto-spawning of udevd.
41 This version of udev conflicts with systemd version below 25. The
42 unchanged service files will not wirk correctly.
48 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
49 /run mountpoint is supposed to be a tmpfs mounted during early boot,
50 available and writable to for all tools at any time during bootup,
51 it replaces /var/run/, which should become a symlink some day.
53 If /run does not exist, or is not writable, udev will fall back using
56 On systemd systems with initramfs and LVM used, packagers must
57 make sure, that the systemd and initramfs versions match. The initramfs
58 needs to create the /run mountpoint for udev to store the data, and
59 mount this tmpfs to /run in the rootfs, so the that the udev database
60 is preserved for the udev version started in the rootfs.
62 The command 'udevadm info --convert-db' is gone. The udev daemon
63 itself, at startup, converts any old database version if necessary.
65 The systemd services files have been reorganized. The udev control
66 socket is bound by systemd and passed to the started udev daemon.
67 The udev-settle.service is no longer active by default. Services which
68 can not handle hotplug setups properly need to actively pull it in, to
69 act like a barrier. Alternatively the settle service can be unconditionally
70 'systemctl'enabled, and act like a barrier for basic.target.
72 The fstab_import callout is no longer built or installed. Udev
73 should not be used to mount, does not watch changes to fstab, and
74 should not mirror fstab values in the udev database.
80 New and updated keymaps.
86 The udev database has changed, After installation of a new udev
87 version, 'udevadm info --convert-db' should be called, to let the new
88 udev/libudev version read the already stored data.
90 udevadm now supports quoting of property values, and prefixing of
92 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
100 udev_device_get_is_initialized()
101 udev_enumerate_add_match_is_initialized()
102 to be able to skip devices the kernel has created , but udev has
105 libudev now supports:
106 udev_device_get_usec_since_initialized()
107 to retrieve the "age" of a udev device record.
109 GUdev supports a more generic GUdevEnumerator class, udev TAG
110 handling, device initialization and timestamp now.
112 The counterpart of /sys/dev/{char,block}/$major:$minor,
113 /dev/{char,block}/$major:$minor symlinks are now unconditionally
114 created, even when no rule files exist.
116 New and updated keymaps.
122 GUdev moved from /usr to /.
132 Persistent network naming rules are disabled inside of Qemu/KVM now.
134 New and updated keymaps.
136 Udev gets unconditionally enabled on systemd installations now. There
137 is no longer the need to to run 'systemctl enable udev.service'.
151 New and fixed keymaps.
153 Install systemd service files if applicable.
159 All distribution specific rules are removed from the udev source tree,
160 most of them are no longer needed. The Gentoo rules which allow to support
161 older kernel versions, which are not covered by the default rules anymore
162 has moved to rules/misc/30-kernel-compat.rules.
168 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
169 was removed from udevd.
171 Udevd now checks the kernel commandline for the following variables:
172 udev.log-priority=<syslog priority>
173 udev.children-max=<maximum number of workers>
174 udev.exec-delay=<seconds to delay the execution of RUN=>
175 to help debuging coldplug setups where the loading of a kernel
176 module crashes the system.
178 The subdirectory in the source tree rules/packages has been renamed to
179 rules/arch, anc contains only architecture specific rules now.
189 Now the udev daemon itself, does on startup:
190 - copy the content of /lib/udev/devices to /dev
191 - create the standard symlinks like /dev/std{in,out,err},
192 /dev/core, /dev/fd, ...
193 - use static node information provided by kernel modules
194 and creates these nodes to allow module on-demand loading
195 - possibly apply permissions to all ststic nodes from udev
196 rules which are annotated to match a static node
198 The default mode for a device node is 0600 now to match the kernel
199 created devtmpfs defaults. If GROUP= is specified and no MODE= is
200 given the default will be 0660.
206 Udev now gradually starts to pass control over the primary device nodes
207 and their names to the kernel, and will in the end only manage the
208 permissions of the node, and possibly create additional symlinks.
209 As a first step NAME="" will be ignored, and NAME= setings with names
210 other than the kernel provided name will result in a logged warning.
211 Kernels that don't provide device names, or devtmpfs is not used, will
212 still work as they did before, but it is strongly recommended to use
213 only the same names for the primary device node as the recent kernel
214 provides for all devices.
218 Fix broken firmware loader search path.
224 "udevadm trigger" defaults to "change" events now instead of "add"
225 events. The "udev boot script" might need to add "--action=add" to
226 the trigger command if not already there, in case the initial coldplug
227 events are expected as "add" events.
229 The option "all_partitons" was removed from udev. This should not be
230 needed for usual hardware. Udev can not safely make assumptions
231 about non-existing partition major/minor numbers, and therefore no
232 longer provide this unreliable and unsafe option.
234 The option "ignore_remove" was removed from udev. With devtmpfs
235 udev passed control over device nodes to the kernel. This option
236 should not be needed, or can not work as advertised. Neither
237 udev nor the kernel will remove device nodes which are copied from
238 the /lib/udev/devices/ directory.
240 All "add|change" matches are replaced by "!remove" in the rules and
241 in the udev logic. All types of events will update possible symlinks
242 and permissions, only "remove" is handled special now.
244 The modem modeswitch extra was removed and the external usb_modeswitch
245 program should be used instead.
247 New and fixed keymaps.
257 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
258 depend on the current sysfs layout and the information not available in the
259 deprecated layout. All remaining support for the deprecated sysfs layout is
264 Fix for a possible endless loop in the new input_id program.
270 The option "ignore_device" does no longer exist. There is no way to
271 ignore an event, as libudev events can not be suppressed by rules.
272 It only prevented RUN keys from being executed, which results in an
273 inconsistent behavior in current setups.
275 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
276 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
279 The support for the deprecated IDE devices has been removed from the
280 default set of rules. Distros who still care about non-libata drivers
281 need to add the rules to the compat rules file.
283 The ID_CLASS property on input devices has been replaced by the more accurate
284 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
285 determined by the new "input_id" prober now. Some devices, such as touchpads,
286 can have several classes. So if you previously had custom udev rules which e. g.
287 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
288 ENV{ID_INPUT_KEYBOARD}=="?*".
294 To support DEVPATH strings larger than the maximum file name length, the
295 private udev database format has changed. If some software still reads the
296 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
297 Please do not port anything to the new format again, everything in /dev/.udev
298 is and always was private to udev, and may and will change any time without
301 Multiple devices claiming the same names in /dev are limited to symlinks
302 only now. Mixing identical symlink names and node names is not supported.
303 This reduces the amount of data in the database significantly.
305 NAME="%k" causes a warning now. It's is and always was completely superfluous.
306 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
309 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
310 if they are not the default. To support older kernels, the NAME= rules need to
311 be added to the compat rules file.
313 Symlinks to udevadm with the old command names are no longer resolved to
314 the udevadm commands.
316 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
319 The option "last_rule" does no longer exist. Its use breaks too many
320 things which expect to be run from independent later rules, and is an idication
321 that something needs to be fixed properly instead.
323 The gudev API is no longer marked as experimental,
324 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
325 is enabled by default now. Various projects already depend on introspection
326 information to bind dynamic languages to the gudev interfaces.
332 The udevadm trigger "--retry-failed" option, which is replaced since quite
333 a while by "--type=failed" is removed.
335 The failed tracking was not working at all for a few releases. The RUN
336 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
337 default is not to track any failing RUN executions.
339 New keymaps, new modem, hid2hci updated.
343 Fix possible crash in udevd when worker processes are busy, rules are
344 changed at the same time, and workers get killed to reload the rules.
350 Properties set with ENV{.FOO}="bar" are marked private by starting the
351 name with a '.'. They will not be stored in the database, and not be
352 exported with the event.
354 Firmware files are looked up in:
355 /lib/firmware/updates/$(uname -r)
356 /lib/firmware/updates
357 /lib/firmware/$(uname -r)
361 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
362 ata_id, instead of scsi_id, is the default tool now for ATA devices.
368 The configure options have changed because another library needs to be
369 installed in a different location. Instead of exec_prefix and udev_prefix,
370 libdir, rootlibdir and libexecdir are used. The Details are explained in
373 Event processes now get re-used after they handled an event. This reduces
374 the number of forks and the pressure on the CPU significantly, because
375 cloned event processes no longer cause page faults in the main daemon.
376 After the events have settled, a few worker processes stay around for
377 future events, all others get cleaned up.
379 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
380 Also inotify support is mandatory now to run udev.
382 The format of the queue exported by the udev damon has changed. There is
383 no longer a /dev/.udev/queue/ directory. The current event queue can be
384 accessed with udevadm settle and libudedv.
386 Libudev does not have the unstable API header anymore. From now on,
387 incompatible changes will be handled by bumping the library major version.
389 To build udev from the git tree gtk-doc is needed now. The tarballs will
390 build without it and contain the pre-built documentation. An online copy
392 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
394 The tools from the udev-extras repository have been merged into the main
395 udev repository. Some of the extras have larger external dependencies, and
396 they can be disabled with the configure switch --disable-extras.
402 The program vol_id and the library libvolume_id are removed from the
403 repository. Libvolume_id is merged with libblkid from the util-linux-ng
404 package. Persistent disk links for label and uuid depend on the
405 util-linux-ng version (2.15) of blkid now. Older versions of blkid
406 can not be used with udev.
408 Libudev allows to subscribe to udev events. To prevent unwanted messages
409 to be delivered, and waking up the subscribing process, a filter can be
410 installed, to drop messages inside a kernel socket filter. The filters
411 match on the <subsytem>:<devtype> properties of the device.
412 This is part of the ongoing effort to replace HAL, and switch current
413 users over to directly use libudev.
414 Libudev is still marked as experimental, and its interface might
415 eventually change if needed, but no major changes of the currently exported
416 interface are expected anymore, and a first stable release should happen
419 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
420 is not supported since while and udevd will log an error message at
421 startup. It should still be able to boot-up, but advanced rules and system
422 services which depend on the information not available in the old sysfs
423 format will fail to work correctly.
425 DVB device naming is supplied by the kernel now. In case older kernels
426 need to be supported, the old shell script should be added to a compat
433 The processed udev events get send back to the netlink socket. Libudev
434 provides access to these events. This is work-in-progress, to replace
435 the DeviceKit daemon functionality directly with libudev. There are
436 upcoming kernel changes to allow non-root users to subcribe to these
443 "udevadm settle" now optionally accepts a range of events to wait for,
444 instead of waiting for "all" events.
450 The installed watch for block device metadata changes is now removed
451 during event hadling, because some (broken) tools may be called from udev
452 rules and (wrongly) open the device with write access. After the finished
453 event handling the watch is restored.
459 Device nodes can be watched for changes with inotify with OPTIONS="watch".
460 If closed after being opened for writing, a "change" uevent will occur.
461 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
467 The udevadm test command has no longer a --force option, nodes and symlinks
468 are always updated with a test run now.
470 The udevd daemon can be started with --resolve-names=never to avoid all user
471 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
472 lookup user and groups every time events are handled.
478 We are currently merging the Ubuntu rules in the udev default rules,
479 and get one step closer to provide a common Linux /dev setup, regarding
480 device names, symlinks, and default device permissions. On udev startup,
481 we now expect the following groups to be resolvable to their ids with
483 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
484 LDAP setups need to make sure, that these groups are always resolvable at
485 bootup, with only the rootfs mounted, and without network access available.
487 Some systems may need to add some new, currently not used groups, or need
488 to add some users to new groups, but the cost of this change is minimal,
489 compared to the pain the current, rather random, differences between the
490 various distributions cause for upstream projects and third-party vendors.
492 In general, "normal" users who log into a machine should never be a member
493 of any such group, but the device-access should be managed by dynamic ACLs,
494 which get added and removed for the specific users on login/logout and
495 session activity/inactivity. These groups are only provided for custom setups,
496 and mainly system services, to allow proper privilege separation.
497 A video-streaming daemon uid would be a member of "audio" and "video", to get
498 access to the sound and video devices, but no "normal" user should ever belong
499 to the "audio" group, because he could listen to the built-in microphone with
500 any ssh-session established from the other side of the world.
502 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
503 which do not depend on the kernel device name. As usual, unique
504 devices - only a single one per product connected, or a real
505 USB serial number in the device - are always found with the same
506 name in the by-id/ directory.
507 Completely identical devices may overwrite their names in by-id/
508 and can only be found reliably in the by-path/ directory. Devices
509 specified by by-path/ must not change their connection, like the
510 USB port number they are plugged in, to keep their name.
512 To support some advanced features, Linux 2.6.22 is the oldest supported
513 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
514 supported. Older kernels should still work, and devices nodes should be
515 reliably created, but some rules and libudev will not work correctly because
516 the old kernels do not provide the expected information or interfaces.
522 Fix for a possible segfault while swapping network interface names in udev
529 The group "video" is part of the default rules now.
533 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
534 block devices in some cases. No common distro uses this option anymore,
535 and we do not get enough testing for this and recent udev versions. If
536 this option is not needed to run some old distro with a new kernel,
537 it should be disabled in the kernel config.
539 Bugfix for the $links substitution variable, which may crash if no links
540 are created. This should not happen in usual setups because we always
541 create /dev/{block,char}/ links.
543 The strings of the parsed rules, which are kept in memory, no longer
544 contain duplicate entries, or duplicate tails of strings. This, and the
545 new rules parsing/matching code reduces the total in-memory size of
546 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
549 The export of DEVTYPE=disk/partition got removed from the default
550 rules. This value is available from the kernel. The pnp shell script
551 modprobe hack is removed from the default rules. ACPI devices have _proper_
552 modalias support and take care of the same functionality.
553 Installations which support old kernels, but install current default
554 udev rules may want to add that to the compat rules file.
556 Libvolume_id now always probes for all known filesystems, and does not
557 stop at the first match. Some filesystems are marked as "exclusive probe",
558 and if any other filesytem type matches at the same time, libvolume_id
559 will, by default, not return any probing result. This is intended to prevent
560 mis-detection with conflicting left-over signatures found from earlier
561 file system formats. That way, we no longer depend on the probe-order
562 in case of multiple competing signatures. In some setups the kernel allows
563 to mount a volume with just the old filesystem signature still in place.
564 This may damage the new filesystem and cause data-loss, just by mounting
565 it. Because volume_id can not decide which one the correct signature is,
566 the wrong signatures need to be removed manually from the volume, or the
567 volume needs to be reformatted, to enable filesystem detection and possible
572 Fix segfault if compiled without optimization and dbg() does not get
573 compiled out and uses variables which are not available.
577 Bugfixes. (And maybe new bugs. :))
579 The rule matching engine got converted from a rule list to a token
580 array which reduced the in-memory rules representation of a full
581 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
582 Limits like 5 ENV and ATTR matches, and one single instance for most
583 other keys per rule are gone.
585 The NAME assignment is no longer special cased. If later rules assign
586 a NAME value again, the former value will be overwritten. As usual
587 for most other keys, the NAME value can be protected by doing a final
588 assignment with NAME:="<value>".
590 All udev code now uses libudev, which is also exported. The library
591 is still under development, marked as experimental, and its interface
592 may change as long as the DeviceKit integration is not finished.
594 Many thanks to Alan Jenkins for his continuous help, and finding and
595 optimizing some of the computing expensive parts.
601 Kernel devices and device nodes are connected now by reverse indizes in
602 /sys and /dev. A device number retrieved by a stat() or similar, the
603 kernel device directory can be found by looking up:
604 /sys/dev/{block,char}/<maj>:<min>
605 and the device node of the same device by looking up:
606 /dev/{block,char}/<maj>:<min>
610 Fix recently introduced bug, which caused a compilation without large
611 file support, where vol_id does not recognize raid signatures at the end
614 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
615 Seems some kernel versions prevent the creation of the ieee-* links,
616 so people used the scsi-* link which disappeared now.
618 More libudev work. Almost all udevadm functionality comes from libudev
621 udevadm trigger has a new option --type, which allows to trigger events
622 for "devices", for "subsystems", or "failed" devices. The old option
623 --retry-failed" still works, but is no longer mentioned in the man page.
629 The udevadm info --device-id-of-file= output has changed to use
630 the obvious format. Possible current users should use the --export
631 option which is not affected.
633 The old udev commands symlinks to udevadm are not installed, if
634 these symlinks are used, a warning is printed.
640 Optical drive's media is no longer probed for raid signatures,
641 reading the end of the device causes some devices to malfunction.
642 Also the offset of the last session found is used now to probe
645 The volume_id library got a major version number update to 1,
646 some deprecated functions are removed.
648 A shared library "libudev" gets installed now to provide access
649 to udev device information. DeviceKit, the successor of HAL, will
650 need this library to access the udev database and search sysfs for
652 The library is currently in an experimental state, also the API is
653 expected to change, as long as the DeviceKit integration is not
658 We use ./configure now. See INSTALL for details. Current
661 "/usr" - prefix for man pages, include files
663 "" - the root filesystem, prefix for libs and binaries
667 "lib" - directory name for libraries, not a path name
668 multilib 64bit systems may use "lib64" instead of "lib"
670 compile-in verbose debug messages
672 disable all logging and compile-out all log strings
674 link against SELInux libraries, to set the expected context
677 In the default rules, the group "disk" gets permissions 0660 instead
678 of 0640. One small step closer to unify distro rules. Some day, all
679 distros hopefully end up with the same set of rules.
681 No symlinks to udevadm are installed anymore, if they are still needed,
682 they should be provided by the package.
688 Default udev rules, which are not supposed to be edited by the user, should
689 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
690 the udev package and will be replaced with an update. Udev will pick up rule
692 /lib/udev/rules.d/ - default installed rules
693 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
694 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
695 It does not matter in which directory a rule file lives, all files are sorted
698 To help creating /dev/root, we have now:
699 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
702 In case the current --device-id-of-file is already used, please switch to
703 the --export format version, it saves the output parsing and the old
704 format will be changed to use ':' as a separator, like the format in the
709 Fix cdrom_id to properly recognize blank media.
715 Tape drive id-data is queried from /dev/bsg/* instead of the tape
716 nodes. This avoids rewinding tapes on open().
722 The symlinks udevcontrol and udevtrigger are no longer installed by
725 The scsi_id program does not depend on sysfs anymore. It can speak
726 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
727 data, which should solve some old problems with tape devices, where
728 we better do not open all tape device nodes to identify the device.
734 The cdrom_id program is replaced by an advanced version, which can
735 detect most common device types, and also properties of the inserted
736 media. This is part of moving some basic functionality from HAL into
737 udev (and the kernel).
743 The last WAIT_FOR_SYSFS rule is removed from the default rules.
745 The symlinks to udevadm for the debugging tools: udevmonitor and
746 udevtest are no longer created.
748 The symlinks to the udevadm man page for the old tool names are
751 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
752 should be prefixed with '@' to indicate that the path is not a
763 Udevstart is removed from the tree, it did not get installed for
764 a long time now, and is long replaced by trigger and settle.
770 All udev tools are merged into a single binary called udevadm.
771 The old names of the tools are built-in commands in udevadm now.
772 Symlinks to udevadm, with the names of the old tools, provide
773 the same functionality as the standalone tools. There is also
774 only a single udevadm.8 man page left for all tools.
776 Tools like mkinitramfs should be checked, if they need to include
777 udevadm in the list of files.
787 The etc/udev/rules.d/ directory now contains a default set of basic
788 udev rules. This initial version is the result of a rules file merge
789 of Fedora and openSUSE. For these both distros only a few specific
790 rules are left in their own file, named after the distro. Rules which
791 are optionally installed, because they are only valid for a specific
792 architecture, or rules for subsystems which are not always used are
793 in etc/udev/packages/.
799 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
800 actions by dynamically created rules.
802 SYMLINK=="<value>" matches agains the entries in the list of
803 currently defined symlinks. The links are not created in the
804 filesystem at that point in time, but the values can be matched.
806 RUN{ignore_error}+="<program>" will ignore any exit code from the
807 program and not record as a failed event.
813 Final merge of patches/features from the Ubuntu package.
819 Control characters in filesystem label strings are no longer silenty
820 removed, but hex-encoded, to be able to uniquely identify the device
821 by its symlink in /dev/disk/by-label/.
822 If libvolume_id is used by mount(8), LABEL= will work as expected,
823 if slashes or other characters are used in the label string.
825 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
826 can be specified now. The TEST key accepts an optional mode mask
827 TEST{0100}=="<is executable file>".
829 Scsi_id now supports a mode without expecting scsi-specific sysfs
830 entries to allow the extraction of cciss-device persistent properties.
836 In the future, we may see uuid's which are just simple character
837 strings (see the DDF Raid Specification). For that reason vol_id now
838 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
839 the creation of symlinks, the *_SAFE values ensure, that no control
840 or whitespace characters are used in the filename.
842 Possible users of libvolume_id, please use the volume_id_get_* functions.
843 The public struct will go away in a future release of the library.
849 Removal of useless extras/eventrecorder.sh.
859 The directory multiplexer for dev.d/ and hotplug.d are finally removed
860 from the udev package.
866 Symlinks can have priorities now, the priority is assigned to the device
867 and specified with OPTIONS="link_priority=100". Devices with higher
868 priorities overwrite the symlinks of devices with lower priorities.
869 If the device that currently owns the link, goes away, the symlink
870 will be removed, and recreated, pointing to the next device with the
871 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
872 more reliable, if multiple devices contain the same metadata and overwrite
875 The dasd_id program is removed from the udev tree, and dasdinfo, with the
876 needed rules, are part of the s390-tools now.
878 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
879 we may get the scsi sysfs mess fixed some day, and this will only catch
880 the devices we are looking for.
882 USB serial numbers for storage devices have the target:lun now appended,
883 to make it possibble to distinguish broken multi-lun devices with all
884 the same SCSI identifiers.
886 Note: The extra "run_directory" which searches and executes stuff in
887 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
888 with the next release. Make sure, that you don't use it anymore, or
889 provides your own implementation of that inefficient stuff.
890 We are tired of reports about a "slow udev", because these directories
891 contain stuff, that runs with _every_ event, instead of using rules,
892 that run programs only for the matching events.
902 DRIVER== will match only for devices that actually have a real
903 driver. DRIVERS== must be used, if parent devices should be
904 included in the match.
906 Libvolume_id's "linux_raid" detection needed another fix.
914 Add additional check to volume_id detection of via_raid, cause
915 some company decided to put a matching pattern all over the empty
916 storage area of their music players.
920 Fix path_id for SAS devices.
924 The udev daemon can be started with --debug-trace now, which will
925 execute all events serialized to get a chance to catch a possible
926 action that crashes the box.
928 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
929 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
930 are excluded from the warning. Referencing parent attributes directly
931 may break when something in the kernel driver model changes. Udev will
932 just find the attribute by walking up the parent chain.
934 Udevtrigger now sorts the list of devices depending on the device
935 dependency, so a "usb" device is triggered after the parent "pci"
940 Revert persistent-storage ata-serial '_' '-' replacement.
946 Udevtrigger can now filter the list of devices to be triggered. Matches
947 for subsystems or sysfs attributes can be specified.
949 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
950 zero-sized files to avoid pointing to /sys and confuse broken tools which
951 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
954 The rules and scripts to create udev rules for persistent network
955 devices and optical drives are in the extras/rules_generator directory
956 now. If you use something similar, please consider replacing your own
957 version with this, to share the support effort. The rule_generator
958 installs its own rules into /etc/udev/rules.d.
960 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
961 the rule_generator depends on cdrom_id to be called in an earlier rule.
967 Renaming of some key names (the old names still work):
968 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
969 (The behavior of the key DRIVER will change soon in one of the next
970 releases, to match only the event device, please switch to DRIVERS
971 instead. If DRIVER is used, it will behave like DRIVERS, but an error
973 With the new key names, we have a more consistent and simpler scheme.
974 We can match the properties of the event device only, with: KERNEL,
975 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
976 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
977 longer mentioned in the man page and should be switched in the rule
980 ATTR{file}="value" can be used now, to write to a sysfs file of the
981 event device. Instead of:
982 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
984 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
986 All the PHYSDEV* keys are deprecated and will be removed from a
988 PHYDEVPATH - is the path of a parent device and should not be
990 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
991 matched with SUBSYSTEMS==
992 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
993 Newer kernels will have DRIVER in the environment,
994 for older kernels udev puts in. Class device will
995 no longer carry this property of a parent and
996 DRIVERS== can be used to match such a parent value.
997 Note that ENV{DRIVER} is only available for a few bus devices, where
998 the driver is already bound at device event time. On coldplug, the
999 events for a lot devices are already bound to a driver, and they will have
1000 that value set. But on hotplug, at the time the kernel creates the device,
1001 it can't know what driver may claim the device after that, therefore
1002 in most cases it will be empty.
1004 Failed events should now be re-triggered with:
1005 udevtrigger --retry-failed.
1006 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1007 files private to the udev tools. We may need to switch the current symlink
1008 target, cause some obviously broken tools try to scan all files in /dev
1009 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1010 million times. This takes ages on slow boxes.
1012 The udevinfo attribute walk (-a) now works with giving a device node
1013 name (-n) instead of a devpath (-p). The query now always works, also when
1014 no database file was created by udev.
1016 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1017 getpwnam() and getgrnam() now. One of the next releases will depend on
1018 fnmatch() and may use getopt_long().
1022 Bugfixes and small improvements.
1026 Fix path_id for recent kernels.
1032 Added support for swapping network interface names, by temporarily
1033 renaming the device and wait for the target name to become free.
1037 The built-in MODALIAS key and substitution is removed.
1041 The binary firmware helper is replaced by the usual simple
1042 shell script. Udevsend is removed from the tree.
1050 Some more keys require the correct use of '==' and '=' depending
1051 on the kind of operation beeing an assignment or a match. Rules
1052 with invalid operations are skipped and logged to syslog. Please
1053 test with udevtest if the parsing of your rules throws errors and
1054 fix possibly broken rules.
1058 Provide "udevsettle" to wait for all current udev events to finish.
1059 It also watches the current kernel netlink queue by comparing the
1060 even sequence number to make sure that there are no current pending
1061 events that have not already arrived in the daemon.
1065 Fix rule to skip persistent rules for removable IDE devices, which
1066 also skipped optical IDE drives.
1068 All *_id program are installed in /lib/udev/ by default now.
1070 No binary is stripped anymore as this should be done in the
1071 packaging process and not at build time.
1073 libvolume_id is provided as a shared library now and vol_id is
1074 linked against it. Also one of the next HAL versions will require
1075 this library, and the HAL build process will also require the
1076 header file to be installed. The copy of the same code in HAL will
1077 be removed to have only a single copy left on the system.
1081 Add persistent links for SCSI tapes. The rules file is renamed
1082 to 60-persistent-storage.rules.
1084 Create persistent path for usb devices. Can be used for all sorts
1085 of devices that can't be distinguished by other properties like
1086 multiple identical keyboards and mice connected to the same box.
1088 Provide "udevtrigger" program to request events on coldplug. The
1089 shell script is much too slow with thousends of devices.
1093 Fix persistent disk rules to exclude removable IDE drives.
1095 Warn if %e, $modalias or MODALIAS is used.
1099 Fix queue export, which wasn't correct for subsequent add/remove
1100 events for the same device.
1104 Fix cramfs detection on big endian.
1106 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1111 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1112 attributes were only checked at the parent device that matched the
1113 by BUS requested subsystem. Fix it to also look at the device we
1114 received the event for.
1116 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1121 Fix a bug where NAME="" would prevent RUN from beeing executed.
1123 RUN="/bin/program" does not longer automatically add the subsystem
1124 as the first parameter. This is from the days of /sbin/hotplug
1125 which is dead now and it's just confusing to need to add a space at
1126 the end of the program name to prevent this.
1127 If you use rules that need the subsystem as the first parameter,
1128 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1129 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1133 The udev man page has moved to udev(7) as it does not describe a command
1134 anymore. The programs udev, udevstart and udevsend are no longer installed
1135 by default and must be copied manually, if they should be installed or
1136 included in a package.
1138 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1139 the ignore rule was applied.
1141 More preparation for future sysfs changes. usb_id and scsi_id no longer
1142 depend on a magic order of devices in the /devices chain. Specific devices
1143 should be requested by their subsytem.
1145 This will always find the scsi parent device without depending on a specific
1147 dev = sysfs_device_get(devpath);
1148 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1150 The "device" link in the current sysfs layout will be automatically
1151 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1152 parent in the devpath. If a device is requested by it's symlink, like all
1153 class devices in the new sysfs layout will look like, it gets automatically
1154 resolved and substituted with the real devpath and not the symlink path.
1157 A similar logic must be applied to _all_ sysfs users, including
1158 scripts, that search along parent devices in sysfs. The explicit use of
1159 the "device" link must be avoided. With the future sysfs layout all
1160 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1161 back to the "class" or the "bus". The layout of the parent devices in
1162 /devices is not necessarily expected to be stable across kernel releases and
1163 searching for parents by their subsystem should make sysfs users tolerant
1164 for changed parent chains.
1168 Prepare udev to work with the experimental kernel patch, that moves
1169 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1171 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1172 moving the class devices to /sys/devices.
1174 Thanks again to Marco for help finding a hopefully nice compromise
1175 to make %b simpler and working again.
1179 Complete removal of libsysfs, replaced by simple helper functions
1180 which are much simpler and a bit faster. The udev daemon operatesentirely
1181 on event parameters and does not use sysfs for simple rules anymore.
1182 Please report any new bugs/problems, that may be caused by this big
1183 change. They will be fixed immediately.
1185 The enumeration format character '%e' is deprecated and will be
1186 removed sometimes from a future udev version. It never worked correctly
1187 outside of udevstart, so we can't use it with the new parallel
1188 coldplug. A simple enumeration is as useless as the devfs naming
1189 scheme, just get rid of both if you still use it.
1191 MODALIAS and $modalias is not needed and will be removed from one of
1192 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1193 the sysfs "modalias" value.
1195 Thanks a lot to Marco for all his help on finding and fixing bugs.
1199 Let scsi_id request libata drive serial numbers from page 0x80.
1201 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1202 added /dev/disk/by-name/* for device mapper device names.
1204 Removed %e from the man page. It never worked reliably outside
1205 of udevstart and udevstart is no longer recommended to use.
1209 Symlinks are now exported to the event environment. Hopefully it's no
1210 longer needed to run udevinfo from an event process, like it was
1211 mentioned on the hotplug list:
1212 UDEV [1134776873.702967] add@/block/sdb
1215 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1219 Fix a problem if udevsend is used as the hotplug handler and tries to use
1220 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1221 and this kind of problems will hopefully go away soon.
1225 All built-in logic to work around bad sysfs timing is removed with this
1226 version. The need to wait for sysfs files is almost fixed with a kernel
1227 version that doesn't work with this udev version anyway. Until we fix
1228 the timing of the "bus" link creation, the former integrated logic should
1229 be emulated by a rule placed before all other rules:
1230 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1232 The option "udev_db" does no longer exist. All udev state will be in
1233 /$udev_root/.udev/ now, there is no longer an option to set this
1235 If the init script or something else used this value, just depend on
1236 this hardcoded path. But remember _all_content_ of this directory is
1237 still private to udev and can change at any time.
1239 Default location for rule sripts and helper programs is now: /lib/udev/.
1240 Everything that is not useful on the commandline should go into this
1241 directory. Some of the helpers in the extras folder are installed there
1242 now. The rules need to be changed, to find the helpers there.
1244 Also /lib/udev/devices is recommended as a directory where packages or
1245 the user can place real device nodes, which get copied over to /dev at
1246 every boot. This should replace the various solutions with custom config
1249 Udevsend does no longer start the udev daemon. This must be done with
1250 the init script that prepares /dev on tmpfs and creates the initial nodes,
1251 before starting the daemon.
1255 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1258 The copy of klibc is removed. A systemwide installed version of klibc
1259 should be used to build a klibc udev now.
1263 NAME="" will not create any nodes, but execute RUN keys. To completely
1264 ignore an event the OPTION "ignore_device" should be used.
1266 After removal of the reorder queue, events with a TIMEOUT can be executed
1267 without any queuing now.
1271 Fixed bug in udevd, if inotify is not available. We depend on netlink
1272 uevents now, kernels without that event source will not work with that
1273 version of udev anymore.
1277 The rule parsing happens now in the daemon once at startup, all udev
1278 event processes inherit the already parsed rules from the daemon.
1279 It is shipped with SUSE10.0 and reduces heavily the system load at
1280 startup. The option to save precompiled rules and let the udev process
1281 pick the them up is removed, as it's no longer needed.
1283 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1284 device. Libsysfs is changed to "translate" the requested link into the
1285 real device path, as it would happen with the hotplug event. Otherwise
1286 device removal and the udev database will not work.
1288 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1291 A few improvements for vol_id, the filesytem probing code.
1295 Fix a stupid typo in extras/run_directory for "make install".
1297 scsi_id creates the temporary devnode now in /dev for usage with a
1298 non-writable /tmp directory.
1300 The uevent kernel socket buffer can carry app. 50.000 events now,
1301 let's see who can break this again. :)
1303 The upcoming kernel will have a new input driver core integration.
1304 Some class devices are now symlinks to the real device. libsysfs
1305 needs a fix for this to work correctly. Udevstart of older udev
1306 versions will _not_ create these devices!
1310 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1315 A bunch of mostly trivial bugfixes. From now on no node name or
1316 symlink name can contain any character than plain whitelisted ascii
1317 characters or validated utf8 byte-streams. This is needed for the
1318 /dev/disk/by-label/* links, because we import untrusted data and
1319 export it to the filesystem.
1323 More bugfixes. If udevd was started from the kernel, we don't
1324 have stdin/stdout/stderr, which broke the forked tools in some
1329 Bugfix. udevstart event ordering was broken for a long time.
1330 The new run_program() uncovered it, because /dev/null was not
1331 available while we try to run external programs.
1332 Now udevstart should create it before we run anything.
1336 Minor bugfixes and some distro rules updates. If you don't have the
1337 persistent disk rules in /dev/disk/by-*/* on your distro, just
1338 grab it from here. :)
1342 We can use socket communication now to pass events from udev to
1344 RUN+="socket:/org/freedesktop/hal/udev_event"
1345 will pass the whole udev event to the HAL daemon without the need
1346 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1350 Mostly bugfixes and see ChangeLog.
1352 The test for the existence of an environment value should be
1354 ENV{KEY}=="*" to ENV{KEY}=="?*"
1355 because "*" will not fail anymore, if the key does not exist or
1360 Bugfixes and a few tweaks described in the ChangeLog.
1364 Mostly a Bugfix release.
1366 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1367 timing with custom rules.
1371 We changed the internal rule storage format. Our large rule files took
1372 2 MB of RAM, with the change we are down to 99kB.
1374 If the device-node has been created with default name and no symlink or
1375 options are to remenber, it is not longer stored in the udevdb. HAL will
1376 need to be updated to work correctly with that change.
1378 To overrride optimization flags, OPTFLAGS may be used now.
1386 Major changes happened with this release. The goal is to take over the
1387 complete kernel-event handling and provide a more efficient way to dispatch
1388 kernel events. Replacing most of the current shell script logic and the
1389 kernel forked helper with a netlink-daemon and a rule-based event handling.
1391 o udevd listens to netlink events now. The first valid netlink event
1392 will make udevd ignore any message from udevsend that contains a
1393 SEQNUM, to avoid duplicate events. The forked events can be disabled
1395 echo "" > /proc/sys/kernel/hotplug
1396 For full support, the broken input-subsytem needs to be fixed, not to
1397 bypass the driver core.
1399 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1400 removed from udev itself and must be emulated by calling small
1401 helper binaries provided in the extras folder:
1402 make EXTRAS=extras/run_directory/
1403 will build udev_run_devd and udev_run_hotplugd, which can be called
1404 from a rule if needed:
1405 RUN+="/sbin/udev_run_hotplugd"
1406 The recommended way to handle this is to convert all the calls from
1407 the directories to explicit udev rules and get completely rid of the
1408 multiplexing. (To catch a ttyUSB event, you now no longer need to
1409 fork and exit 300 tty script instances you are not interested in, it
1410 is just one rule that matches exactly the device.)
1412 o udev handles now _all_ events not just events for class and block
1413 devices, this way it is possible to control the complete event
1414 behavior with udev rules. Especially useful for rules like:
1415 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1417 o As used in the modalias rule, udev supports now textual
1418 substitution placeholder along with the usual format chars. This
1419 needs to be documented, for now it's only visible in udev_rules_parse.c.
1421 o The rule keys support now more operations. This is documented in the
1422 man page. It is possible to add values to list-keys like the SYMLINK
1423 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1424 Also "final"-assignments are supported by using KEY:="value", which will
1425 prevent changing the key by any later rule.
1427 o kernel 2.6.12 has the "detached_state" attribute removed from
1428 sysfs, which was used to recognize sysfs population. We switched that
1429 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1430 Running this udev version on older kernels may cause a short delay for
1433 o To provide infrastructure for persistent device naming, the id programs:
1434 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1435 to export the probed data in environment key format:
1436 pim:~ # /sbin/ata_id --export /dev/hda
1437 ID_MODEL=HTS726060M9AT00
1438 ID_SERIAL=MRH401M4G6UM9B
1439 ID_REVISION=MH4OA6BA
1441 The following rules:
1442 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1443 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1446 kay@pim:~> tree /dev/disk
1449 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1450 | `-- IBM-Memory_Key -> ../../sda
1452 | |-- swap -> ../../hda1
1453 | |-- date -> ../../sda1
1454 | `-- home -> ../../hda3
1456 |-- 2E08712B0870F2E7 -> ../../hda3
1457 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1458 |-- E845-7A89 -> ../../sda1
1459 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1461 The IMPORT= operation will import these keys in the environment and make
1462 it available for later PROGRAM= and RUN= executed programs. The keys are
1463 also stored in the udevdb and can be queried from there with one of the
1466 o A few binaries are silently added to the repository, which can be used
1467 to replay kernel events from initramfs instead of using coldplug. udevd
1468 can be instructed now to queue-up events while the stored events from
1469 initramfs are filled into the udevd-queue. This code is still under
1470 development and there is no documentation now besides the code itself.
1471 The additional binaries get compiled, but are not installed by default.
1473 o There is also a temporary fix for a performance problem where too many
1474 events happen in parallel and every event needs to parse the rules.
1475 udev can now read precompiled rules stored on disk. This is likely to be
1476 replaced by a more elegant solution in a future udev version.
1480 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1481 Fix for libsysfs not to expect this file was added.
1485 All rules are applied now, but only the first matching rule with a NAME-key
1486 will be applied. All later rules with NAME-key are completely ignored. This
1487 way system supplied symlinks or permissions gets applied to user-defined
1491 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1492 to some rules, to keep the old behavior.
1494 The rules are read on "remove"-events too. That makes is possible to match
1495 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1496 instruct udev to ignore an event (OPTIONS="ignore_device").
1497 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1499 The new RUN-key supports rule-based execution of programs after device-node
1500 handling. This is meant as a general replacement for the dev.d/-directories
1501 to give fine grained control over the execution of programs.
1503 The %s{}-sysfs format char replacement values are searched at any of the
1504 devices in the device chain now, not only at the class-device.
1506 We support log priority levels now. The value udev_log in udev.conf is used
1507 to determine what is printed to syslog. This makes it possible to
1508 run a version with compiled-in debug messages in a production environment
1509 which is sometimes needed to find a bug.
1510 It is still possible to supress the inclusion of _any_ syslog usage with
1511 USE_LOG=false to create the smallest possible binaries if needed.
1512 The configured udev_log value can be overridden with the environment variable
1517 Possible use of a system-wide klibc:
1518 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1519 will link against an external klibc and our own version will be ignored.
1523 We support an unlimited count of symlinks now.
1525 If USE_STATIC=true is passed to a glibc build, we link statically and use
1526 a built-in userdb parser to resolve user and group names.
1528 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1529 we walk up the chain of physical devices to find a match.
1531 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1532 easy to skip certain attribute matches without composing rules with weird
1533 character class negations like:
1534 KERNEL="[!s][!c][!d]*"
1535 this can now be replaced with:
1537 The current simple '=' is still supported, and should work as it does today,
1538 but existing rules should be converted if possible, to be better readable.
1540 We have new ENV{}== key now, to match against a maximum of 5 environment
1543 udevstart is its own binary again, because we don't need co carry this araound
1544 with every forked event.