5 We require at least Linux kernel 2.6.32 now. Some platforms might
6 require a later kernel that supports accept4(), or need to backport
7 the accept4() syscall wiring.
9 The hid2hci tool move to the bluez package and was removed.
11 Many of the extras can be --enabled/--disabled during configure
12 now. The --disable-extras option was removed. To check the
13 current options, the usual './configure --help' prints them.
19 Udev logs a warning now if /run is not writable at udevd
20 startup. It will still fall back to /dev/.udev, but this is
23 The running udev daemon can now cleanly shut down with:
24 udevadm control --exit
26 Udev in initramfs should clean the state of the udev database
27 with: udevadm info --cleanup-db which will remove all state left
28 behind from events/rules in initramfs. If initramfs uses
29 --cleanup-db and device-mapper/LVM, the rules in initramfs need
30 to add OPTIONS+="db_persist" for all dm devices. This will
31 prevent removal of the udev database for these devices.
33 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
34 120 seconds per process. If that timeout is reached the spawned
35 process will be killed. The event timeout can be overwritten with
38 If systemd is used, udev gets now activated by netlink data.
39 Systemd will bind the netlink socket which will buffer all data.
40 If needed, such setup allows a seemless update of the udev daemon,
41 where no event can be lost during a udevd update/restart.
42 Packages need to make sure to: systemctl stop udev.socket udev.service
43 or 'mask' udev.service during the upgrade to prevent any unwanted
44 auto-spawning of udevd.
45 This version of udev conflicts with systemd version below 25. The
46 unchanged service files will not wirk correctly.
52 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
53 /run mountpoint is supposed to be a tmpfs mounted during early boot,
54 available and writable to for all tools at any time during bootup,
55 it replaces /var/run/, which should become a symlink some day.
57 If /run does not exist, or is not writable, udev will fall back using
60 On systemd systems with initramfs and LVM used, packagers must
61 make sure, that the systemd and initramfs versions match. The initramfs
62 needs to create the /run mountpoint for udev to store the data, and
63 mount this tmpfs to /run in the rootfs, so the that the udev database
64 is preserved for the udev version started in the rootfs.
66 The command 'udevadm info --convert-db' is gone. The udev daemon
67 itself, at startup, converts any old database version if necessary.
69 The systemd services files have been reorganized. The udev control
70 socket is bound by systemd and passed to the started udev daemon.
71 The udev-settle.service is no longer active by default. Services which
72 can not handle hotplug setups properly need to actively pull it in, to
73 act like a barrier. Alternatively the settle service can be unconditionally
74 'systemctl'enabled, and act like a barrier for basic.target.
76 The fstab_import callout is no longer built or installed. Udev
77 should not be used to mount, does not watch changes to fstab, and
78 should not mirror fstab values in the udev database.
84 New and updated keymaps.
90 The udev database has changed, After installation of a new udev
91 version, 'udevadm info --convert-db' should be called, to let the new
92 udev/libudev version read the already stored data.
94 udevadm now supports quoting of property values, and prefixing of
96 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
103 libudev now supports:
104 udev_device_get_is_initialized()
105 udev_enumerate_add_match_is_initialized()
106 to be able to skip devices the kernel has created , but udev has
109 libudev now supports:
110 udev_device_get_usec_since_initialized()
111 to retrieve the "age" of a udev device record.
113 GUdev supports a more generic GUdevEnumerator class, udev TAG
114 handling, device initialization and timestamp now.
116 The counterpart of /sys/dev/{char,block}/$major:$minor,
117 /dev/{char,block}/$major:$minor symlinks are now unconditionally
118 created, even when no rule files exist.
120 New and updated keymaps.
126 GUdev moved from /usr to /.
136 Persistent network naming rules are disabled inside of Qemu/KVM now.
138 New and updated keymaps.
140 Udev gets unconditionally enabled on systemd installations now. There
141 is no longer the need to to run 'systemctl enable udev.service'.
155 New and fixed keymaps.
157 Install systemd service files if applicable.
163 All distribution specific rules are removed from the udev source tree,
164 most of them are no longer needed. The Gentoo rules which allow to support
165 older kernel versions, which are not covered by the default rules anymore
166 has moved to rules/misc/30-kernel-compat.rules.
172 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
173 was removed from udevd.
175 Udevd now checks the kernel commandline for the following variables:
176 udev.log-priority=<syslog priority>
177 udev.children-max=<maximum number of workers>
178 udev.exec-delay=<seconds to delay the execution of RUN=>
179 to help debuging coldplug setups where the loading of a kernel
180 module crashes the system.
182 The subdirectory in the source tree rules/packages has been renamed to
183 rules/arch, anc contains only architecture specific rules now.
193 Now the udev daemon itself, does on startup:
194 - copy the content of /lib/udev/devices to /dev
195 - create the standard symlinks like /dev/std{in,out,err},
196 /dev/core, /dev/fd, ...
197 - use static node information provided by kernel modules
198 and creates these nodes to allow module on-demand loading
199 - possibly apply permissions to all ststic nodes from udev
200 rules which are annotated to match a static node
202 The default mode for a device node is 0600 now to match the kernel
203 created devtmpfs defaults. If GROUP= is specified and no MODE= is
204 given the default will be 0660.
210 Udev now gradually starts to pass control over the primary device nodes
211 and their names to the kernel, and will in the end only manage the
212 permissions of the node, and possibly create additional symlinks.
213 As a first step NAME="" will be ignored, and NAME= setings with names
214 other than the kernel provided name will result in a logged warning.
215 Kernels that don't provide device names, or devtmpfs is not used, will
216 still work as they did before, but it is strongly recommended to use
217 only the same names for the primary device node as the recent kernel
218 provides for all devices.
222 Fix broken firmware loader search path.
228 "udevadm trigger" defaults to "change" events now instead of "add"
229 events. The "udev boot script" might need to add "--action=add" to
230 the trigger command if not already there, in case the initial coldplug
231 events are expected as "add" events.
233 The option "all_partitons" was removed from udev. This should not be
234 needed for usual hardware. Udev can not safely make assumptions
235 about non-existing partition major/minor numbers, and therefore no
236 longer provide this unreliable and unsafe option.
238 The option "ignore_remove" was removed from udev. With devtmpfs
239 udev passed control over device nodes to the kernel. This option
240 should not be needed, or can not work as advertised. Neither
241 udev nor the kernel will remove device nodes which are copied from
242 the /lib/udev/devices/ directory.
244 All "add|change" matches are replaced by "!remove" in the rules and
245 in the udev logic. All types of events will update possible symlinks
246 and permissions, only "remove" is handled special now.
248 The modem modeswitch extra was removed and the external usb_modeswitch
249 program should be used instead.
251 New and fixed keymaps.
261 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
262 depend on the current sysfs layout and the information not available in the
263 deprecated layout. All remaining support for the deprecated sysfs layout is
268 Fix for a possible endless loop in the new input_id program.
274 The option "ignore_device" does no longer exist. There is no way to
275 ignore an event, as libudev events can not be suppressed by rules.
276 It only prevented RUN keys from being executed, which results in an
277 inconsistent behavior in current setups.
279 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
280 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
283 The support for the deprecated IDE devices has been removed from the
284 default set of rules. Distros who still care about non-libata drivers
285 need to add the rules to the compat rules file.
287 The ID_CLASS property on input devices has been replaced by the more accurate
288 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
289 determined by the new "input_id" prober now. Some devices, such as touchpads,
290 can have several classes. So if you previously had custom udev rules which e. g.
291 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
292 ENV{ID_INPUT_KEYBOARD}=="?*".
298 To support DEVPATH strings larger than the maximum file name length, the
299 private udev database format has changed. If some software still reads the
300 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
301 Please do not port anything to the new format again, everything in /dev/.udev
302 is and always was private to udev, and may and will change any time without
305 Multiple devices claiming the same names in /dev are limited to symlinks
306 only now. Mixing identical symlink names and node names is not supported.
307 This reduces the amount of data in the database significantly.
309 NAME="%k" causes a warning now. It's is and always was completely superfluous.
310 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
313 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
314 if they are not the default. To support older kernels, the NAME= rules need to
315 be added to the compat rules file.
317 Symlinks to udevadm with the old command names are no longer resolved to
318 the udevadm commands.
320 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
323 The option "last_rule" does no longer exist. Its use breaks too many
324 things which expect to be run from independent later rules, and is an idication
325 that something needs to be fixed properly instead.
327 The gudev API is no longer marked as experimental,
328 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
329 is enabled by default now. Various projects already depend on introspection
330 information to bind dynamic languages to the gudev interfaces.
336 The udevadm trigger "--retry-failed" option, which is replaced since quite
337 a while by "--type=failed" is removed.
339 The failed tracking was not working at all for a few releases. The RUN
340 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
341 default is not to track any failing RUN executions.
343 New keymaps, new modem, hid2hci updated.
347 Fix possible crash in udevd when worker processes are busy, rules are
348 changed at the same time, and workers get killed to reload the rules.
354 Properties set with ENV{.FOO}="bar" are marked private by starting the
355 name with a '.'. They will not be stored in the database, and not be
356 exported with the event.
358 Firmware files are looked up in:
359 /lib/firmware/updates/$(uname -r)
360 /lib/firmware/updates
361 /lib/firmware/$(uname -r)
365 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
366 ata_id, instead of scsi_id, is the default tool now for ATA devices.
372 The configure options have changed because another library needs to be
373 installed in a different location. Instead of exec_prefix and udev_prefix,
374 libdir, rootlibdir and libexecdir are used. The Details are explained in
377 Event processes now get re-used after they handled an event. This reduces
378 the number of forks and the pressure on the CPU significantly, because
379 cloned event processes no longer cause page faults in the main daemon.
380 After the events have settled, a few worker processes stay around for
381 future events, all others get cleaned up.
383 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
384 Also inotify support is mandatory now to run udev.
386 The format of the queue exported by the udev damon has changed. There is
387 no longer a /dev/.udev/queue/ directory. The current event queue can be
388 accessed with udevadm settle and libudedv.
390 Libudev does not have the unstable API header anymore. From now on,
391 incompatible changes will be handled by bumping the library major version.
393 To build udev from the git tree gtk-doc is needed now. The tarballs will
394 build without it and contain the pre-built documentation. An online copy
396 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
398 The tools from the udev-extras repository have been merged into the main
399 udev repository. Some of the extras have larger external dependencies, and
400 they can be disabled with the configure switch --disable-extras.
406 The program vol_id and the library libvolume_id are removed from the
407 repository. Libvolume_id is merged with libblkid from the util-linux-ng
408 package. Persistent disk links for label and uuid depend on the
409 util-linux-ng version (2.15) of blkid now. Older versions of blkid
410 can not be used with udev.
412 Libudev allows to subscribe to udev events. To prevent unwanted messages
413 to be delivered, and waking up the subscribing process, a filter can be
414 installed, to drop messages inside a kernel socket filter. The filters
415 match on the <subsytem>:<devtype> properties of the device.
416 This is part of the ongoing effort to replace HAL, and switch current
417 users over to directly use libudev.
418 Libudev is still marked as experimental, and its interface might
419 eventually change if needed, but no major changes of the currently exported
420 interface are expected anymore, and a first stable release should happen
423 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
424 is not supported since while and udevd will log an error message at
425 startup. It should still be able to boot-up, but advanced rules and system
426 services which depend on the information not available in the old sysfs
427 format will fail to work correctly.
429 DVB device naming is supplied by the kernel now. In case older kernels
430 need to be supported, the old shell script should be added to a compat
437 The processed udev events get send back to the netlink socket. Libudev
438 provides access to these events. This is work-in-progress, to replace
439 the DeviceKit daemon functionality directly with libudev. There are
440 upcoming kernel changes to allow non-root users to subcribe to these
447 "udevadm settle" now optionally accepts a range of events to wait for,
448 instead of waiting for "all" events.
454 The installed watch for block device metadata changes is now removed
455 during event hadling, because some (broken) tools may be called from udev
456 rules and (wrongly) open the device with write access. After the finished
457 event handling the watch is restored.
463 Device nodes can be watched for changes with inotify with OPTIONS="watch".
464 If closed after being opened for writing, a "change" uevent will occur.
465 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
471 The udevadm test command has no longer a --force option, nodes and symlinks
472 are always updated with a test run now.
474 The udevd daemon can be started with --resolve-names=never to avoid all user
475 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
476 lookup user and groups every time events are handled.
482 We are currently merging the Ubuntu rules in the udev default rules,
483 and get one step closer to provide a common Linux /dev setup, regarding
484 device names, symlinks, and default device permissions. On udev startup,
485 we now expect the following groups to be resolvable to their ids with
487 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
488 LDAP setups need to make sure, that these groups are always resolvable at
489 bootup, with only the rootfs mounted, and without network access available.
491 Some systems may need to add some new, currently not used groups, or need
492 to add some users to new groups, but the cost of this change is minimal,
493 compared to the pain the current, rather random, differences between the
494 various distributions cause for upstream projects and third-party vendors.
496 In general, "normal" users who log into a machine should never be a member
497 of any such group, but the device-access should be managed by dynamic ACLs,
498 which get added and removed for the specific users on login/logout and
499 session activity/inactivity. These groups are only provided for custom setups,
500 and mainly system services, to allow proper privilege separation.
501 A video-streaming daemon uid would be a member of "audio" and "video", to get
502 access to the sound and video devices, but no "normal" user should ever belong
503 to the "audio" group, because he could listen to the built-in microphone with
504 any ssh-session established from the other side of the world.
506 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
507 which do not depend on the kernel device name. As usual, unique
508 devices - only a single one per product connected, or a real
509 USB serial number in the device - are always found with the same
510 name in the by-id/ directory.
511 Completely identical devices may overwrite their names in by-id/
512 and can only be found reliably in the by-path/ directory. Devices
513 specified by by-path/ must not change their connection, like the
514 USB port number they are plugged in, to keep their name.
516 To support some advanced features, Linux 2.6.22 is the oldest supported
517 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
518 supported. Older kernels should still work, and devices nodes should be
519 reliably created, but some rules and libudev will not work correctly because
520 the old kernels do not provide the expected information or interfaces.
526 Fix for a possible segfault while swapping network interface names in udev
533 The group "video" is part of the default rules now.
537 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
538 block devices in some cases. No common distro uses this option anymore,
539 and we do not get enough testing for this and recent udev versions. If
540 this option is not needed to run some old distro with a new kernel,
541 it should be disabled in the kernel config.
543 Bugfix for the $links substitution variable, which may crash if no links
544 are created. This should not happen in usual setups because we always
545 create /dev/{block,char}/ links.
547 The strings of the parsed rules, which are kept in memory, no longer
548 contain duplicate entries, or duplicate tails of strings. This, and the
549 new rules parsing/matching code reduces the total in-memory size of
550 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
553 The export of DEVTYPE=disk/partition got removed from the default
554 rules. This value is available from the kernel. The pnp shell script
555 modprobe hack is removed from the default rules. ACPI devices have _proper_
556 modalias support and take care of the same functionality.
557 Installations which support old kernels, but install current default
558 udev rules may want to add that to the compat rules file.
560 Libvolume_id now always probes for all known filesystems, and does not
561 stop at the first match. Some filesystems are marked as "exclusive probe",
562 and if any other filesytem type matches at the same time, libvolume_id
563 will, by default, not return any probing result. This is intended to prevent
564 mis-detection with conflicting left-over signatures found from earlier
565 file system formats. That way, we no longer depend on the probe-order
566 in case of multiple competing signatures. In some setups the kernel allows
567 to mount a volume with just the old filesystem signature still in place.
568 This may damage the new filesystem and cause data-loss, just by mounting
569 it. Because volume_id can not decide which one the correct signature is,
570 the wrong signatures need to be removed manually from the volume, or the
571 volume needs to be reformatted, to enable filesystem detection and possible
576 Fix segfault if compiled without optimization and dbg() does not get
577 compiled out and uses variables which are not available.
581 Bugfixes. (And maybe new bugs. :))
583 The rule matching engine got converted from a rule list to a token
584 array which reduced the in-memory rules representation of a full
585 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
586 Limits like 5 ENV and ATTR matches, and one single instance for most
587 other keys per rule are gone.
589 The NAME assignment is no longer special cased. If later rules assign
590 a NAME value again, the former value will be overwritten. As usual
591 for most other keys, the NAME value can be protected by doing a final
592 assignment with NAME:="<value>".
594 All udev code now uses libudev, which is also exported. The library
595 is still under development, marked as experimental, and its interface
596 may change as long as the DeviceKit integration is not finished.
598 Many thanks to Alan Jenkins for his continuous help, and finding and
599 optimizing some of the computing expensive parts.
605 Kernel devices and device nodes are connected now by reverse indizes in
606 /sys and /dev. A device number retrieved by a stat() or similar, the
607 kernel device directory can be found by looking up:
608 /sys/dev/{block,char}/<maj>:<min>
609 and the device node of the same device by looking up:
610 /dev/{block,char}/<maj>:<min>
614 Fix recently introduced bug, which caused a compilation without large
615 file support, where vol_id does not recognize raid signatures at the end
618 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
619 Seems some kernel versions prevent the creation of the ieee-* links,
620 so people used the scsi-* link which disappeared now.
622 More libudev work. Almost all udevadm functionality comes from libudev
625 udevadm trigger has a new option --type, which allows to trigger events
626 for "devices", for "subsystems", or "failed" devices. The old option
627 --retry-failed" still works, but is no longer mentioned in the man page.
633 The udevadm info --device-id-of-file= output has changed to use
634 the obvious format. Possible current users should use the --export
635 option which is not affected.
637 The old udev commands symlinks to udevadm are not installed, if
638 these symlinks are used, a warning is printed.
644 Optical drive's media is no longer probed for raid signatures,
645 reading the end of the device causes some devices to malfunction.
646 Also the offset of the last session found is used now to probe
649 The volume_id library got a major version number update to 1,
650 some deprecated functions are removed.
652 A shared library "libudev" gets installed now to provide access
653 to udev device information. DeviceKit, the successor of HAL, will
654 need this library to access the udev database and search sysfs for
656 The library is currently in an experimental state, also the API is
657 expected to change, as long as the DeviceKit integration is not
662 We use ./configure now. See INSTALL for details. Current
665 "/usr" - prefix for man pages, include files
667 "" - the root filesystem, prefix for libs and binaries
671 "lib" - directory name for libraries, not a path name
672 multilib 64bit systems may use "lib64" instead of "lib"
674 compile-in verbose debug messages
676 disable all logging and compile-out all log strings
678 link against SELInux libraries, to set the expected context
681 In the default rules, the group "disk" gets permissions 0660 instead
682 of 0640. One small step closer to unify distro rules. Some day, all
683 distros hopefully end up with the same set of rules.
685 No symlinks to udevadm are installed anymore, if they are still needed,
686 they should be provided by the package.
692 Default udev rules, which are not supposed to be edited by the user, should
693 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
694 the udev package and will be replaced with an update. Udev will pick up rule
696 /lib/udev/rules.d/ - default installed rules
697 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
698 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
699 It does not matter in which directory a rule file lives, all files are sorted
702 To help creating /dev/root, we have now:
703 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
706 In case the current --device-id-of-file is already used, please switch to
707 the --export format version, it saves the output parsing and the old
708 format will be changed to use ':' as a separator, like the format in the
713 Fix cdrom_id to properly recognize blank media.
719 Tape drive id-data is queried from /dev/bsg/* instead of the tape
720 nodes. This avoids rewinding tapes on open().
726 The symlinks udevcontrol and udevtrigger are no longer installed by
729 The scsi_id program does not depend on sysfs anymore. It can speak
730 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
731 data, which should solve some old problems with tape devices, where
732 we better do not open all tape device nodes to identify the device.
738 The cdrom_id program is replaced by an advanced version, which can
739 detect most common device types, and also properties of the inserted
740 media. This is part of moving some basic functionality from HAL into
741 udev (and the kernel).
747 The last WAIT_FOR_SYSFS rule is removed from the default rules.
749 The symlinks to udevadm for the debugging tools: udevmonitor and
750 udevtest are no longer created.
752 The symlinks to the udevadm man page for the old tool names are
755 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
756 should be prefixed with '@' to indicate that the path is not a
767 Udevstart is removed from the tree, it did not get installed for
768 a long time now, and is long replaced by trigger and settle.
774 All udev tools are merged into a single binary called udevadm.
775 The old names of the tools are built-in commands in udevadm now.
776 Symlinks to udevadm, with the names of the old tools, provide
777 the same functionality as the standalone tools. There is also
778 only a single udevadm.8 man page left for all tools.
780 Tools like mkinitramfs should be checked, if they need to include
781 udevadm in the list of files.
791 The etc/udev/rules.d/ directory now contains a default set of basic
792 udev rules. This initial version is the result of a rules file merge
793 of Fedora and openSUSE. For these both distros only a few specific
794 rules are left in their own file, named after the distro. Rules which
795 are optionally installed, because they are only valid for a specific
796 architecture, or rules for subsystems which are not always used are
797 in etc/udev/packages/.
803 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
804 actions by dynamically created rules.
806 SYMLINK=="<value>" matches agains the entries in the list of
807 currently defined symlinks. The links are not created in the
808 filesystem at that point in time, but the values can be matched.
810 RUN{ignore_error}+="<program>" will ignore any exit code from the
811 program and not record as a failed event.
817 Final merge of patches/features from the Ubuntu package.
823 Control characters in filesystem label strings are no longer silenty
824 removed, but hex-encoded, to be able to uniquely identify the device
825 by its symlink in /dev/disk/by-label/.
826 If libvolume_id is used by mount(8), LABEL= will work as expected,
827 if slashes or other characters are used in the label string.
829 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
830 can be specified now. The TEST key accepts an optional mode mask
831 TEST{0100}=="<is executable file>".
833 Scsi_id now supports a mode without expecting scsi-specific sysfs
834 entries to allow the extraction of cciss-device persistent properties.
840 In the future, we may see uuid's which are just simple character
841 strings (see the DDF Raid Specification). For that reason vol_id now
842 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
843 the creation of symlinks, the *_SAFE values ensure, that no control
844 or whitespace characters are used in the filename.
846 Possible users of libvolume_id, please use the volume_id_get_* functions.
847 The public struct will go away in a future release of the library.
853 Removal of useless extras/eventrecorder.sh.
863 The directory multiplexer for dev.d/ and hotplug.d are finally removed
864 from the udev package.
870 Symlinks can have priorities now, the priority is assigned to the device
871 and specified with OPTIONS="link_priority=100". Devices with higher
872 priorities overwrite the symlinks of devices with lower priorities.
873 If the device that currently owns the link, goes away, the symlink
874 will be removed, and recreated, pointing to the next device with the
875 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
876 more reliable, if multiple devices contain the same metadata and overwrite
879 The dasd_id program is removed from the udev tree, and dasdinfo, with the
880 needed rules, are part of the s390-tools now.
882 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
883 we may get the scsi sysfs mess fixed some day, and this will only catch
884 the devices we are looking for.
886 USB serial numbers for storage devices have the target:lun now appended,
887 to make it possibble to distinguish broken multi-lun devices with all
888 the same SCSI identifiers.
890 Note: The extra "run_directory" which searches and executes stuff in
891 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
892 with the next release. Make sure, that you don't use it anymore, or
893 provides your own implementation of that inefficient stuff.
894 We are tired of reports about a "slow udev", because these directories
895 contain stuff, that runs with _every_ event, instead of using rules,
896 that run programs only for the matching events.
906 DRIVER== will match only for devices that actually have a real
907 driver. DRIVERS== must be used, if parent devices should be
908 included in the match.
910 Libvolume_id's "linux_raid" detection needed another fix.
918 Add additional check to volume_id detection of via_raid, cause
919 some company decided to put a matching pattern all over the empty
920 storage area of their music players.
924 Fix path_id for SAS devices.
928 The udev daemon can be started with --debug-trace now, which will
929 execute all events serialized to get a chance to catch a possible
930 action that crashes the box.
932 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
933 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
934 are excluded from the warning. Referencing parent attributes directly
935 may break when something in the kernel driver model changes. Udev will
936 just find the attribute by walking up the parent chain.
938 Udevtrigger now sorts the list of devices depending on the device
939 dependency, so a "usb" device is triggered after the parent "pci"
944 Revert persistent-storage ata-serial '_' '-' replacement.
950 Udevtrigger can now filter the list of devices to be triggered. Matches
951 for subsystems or sysfs attributes can be specified.
953 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
954 zero-sized files to avoid pointing to /sys and confuse broken tools which
955 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
958 The rules and scripts to create udev rules for persistent network
959 devices and optical drives are in the extras/rules_generator directory
960 now. If you use something similar, please consider replacing your own
961 version with this, to share the support effort. The rule_generator
962 installs its own rules into /etc/udev/rules.d.
964 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
965 the rule_generator depends on cdrom_id to be called in an earlier rule.
971 Renaming of some key names (the old names still work):
972 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
973 (The behavior of the key DRIVER will change soon in one of the next
974 releases, to match only the event device, please switch to DRIVERS
975 instead. If DRIVER is used, it will behave like DRIVERS, but an error
977 With the new key names, we have a more consistent and simpler scheme.
978 We can match the properties of the event device only, with: KERNEL,
979 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
980 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
981 longer mentioned in the man page and should be switched in the rule
984 ATTR{file}="value" can be used now, to write to a sysfs file of the
985 event device. Instead of:
986 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
988 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
990 All the PHYSDEV* keys are deprecated and will be removed from a
992 PHYDEVPATH - is the path of a parent device and should not be
994 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
995 matched with SUBSYSTEMS==
996 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
997 Newer kernels will have DRIVER in the environment,
998 for older kernels udev puts in. Class device will
999 no longer carry this property of a parent and
1000 DRIVERS== can be used to match such a parent value.
1001 Note that ENV{DRIVER} is only available for a few bus devices, where
1002 the driver is already bound at device event time. On coldplug, the
1003 events for a lot devices are already bound to a driver, and they will have
1004 that value set. But on hotplug, at the time the kernel creates the device,
1005 it can't know what driver may claim the device after that, therefore
1006 in most cases it will be empty.
1008 Failed events should now be re-triggered with:
1009 udevtrigger --retry-failed.
1010 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1011 files private to the udev tools. We may need to switch the current symlink
1012 target, cause some obviously broken tools try to scan all files in /dev
1013 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1014 million times. This takes ages on slow boxes.
1016 The udevinfo attribute walk (-a) now works with giving a device node
1017 name (-n) instead of a devpath (-p). The query now always works, also when
1018 no database file was created by udev.
1020 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1021 getpwnam() and getgrnam() now. One of the next releases will depend on
1022 fnmatch() and may use getopt_long().
1026 Bugfixes and small improvements.
1030 Fix path_id for recent kernels.
1036 Added support for swapping network interface names, by temporarily
1037 renaming the device and wait for the target name to become free.
1041 The built-in MODALIAS key and substitution is removed.
1045 The binary firmware helper is replaced by the usual simple
1046 shell script. Udevsend is removed from the tree.
1054 Some more keys require the correct use of '==' and '=' depending
1055 on the kind of operation beeing an assignment or a match. Rules
1056 with invalid operations are skipped and logged to syslog. Please
1057 test with udevtest if the parsing of your rules throws errors and
1058 fix possibly broken rules.
1062 Provide "udevsettle" to wait for all current udev events to finish.
1063 It also watches the current kernel netlink queue by comparing the
1064 even sequence number to make sure that there are no current pending
1065 events that have not already arrived in the daemon.
1069 Fix rule to skip persistent rules for removable IDE devices, which
1070 also skipped optical IDE drives.
1072 All *_id program are installed in /lib/udev/ by default now.
1074 No binary is stripped anymore as this should be done in the
1075 packaging process and not at build time.
1077 libvolume_id is provided as a shared library now and vol_id is
1078 linked against it. Also one of the next HAL versions will require
1079 this library, and the HAL build process will also require the
1080 header file to be installed. The copy of the same code in HAL will
1081 be removed to have only a single copy left on the system.
1085 Add persistent links for SCSI tapes. The rules file is renamed
1086 to 60-persistent-storage.rules.
1088 Create persistent path for usb devices. Can be used for all sorts
1089 of devices that can't be distinguished by other properties like
1090 multiple identical keyboards and mice connected to the same box.
1092 Provide "udevtrigger" program to request events on coldplug. The
1093 shell script is much too slow with thousends of devices.
1097 Fix persistent disk rules to exclude removable IDE drives.
1099 Warn if %e, $modalias or MODALIAS is used.
1103 Fix queue export, which wasn't correct for subsequent add/remove
1104 events for the same device.
1108 Fix cramfs detection on big endian.
1110 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1115 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1116 attributes were only checked at the parent device that matched the
1117 by BUS requested subsystem. Fix it to also look at the device we
1118 received the event for.
1120 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1125 Fix a bug where NAME="" would prevent RUN from beeing executed.
1127 RUN="/bin/program" does not longer automatically add the subsystem
1128 as the first parameter. This is from the days of /sbin/hotplug
1129 which is dead now and it's just confusing to need to add a space at
1130 the end of the program name to prevent this.
1131 If you use rules that need the subsystem as the first parameter,
1132 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1133 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1137 The udev man page has moved to udev(7) as it does not describe a command
1138 anymore. The programs udev, udevstart and udevsend are no longer installed
1139 by default and must be copied manually, if they should be installed or
1140 included in a package.
1142 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1143 the ignore rule was applied.
1145 More preparation for future sysfs changes. usb_id and scsi_id no longer
1146 depend on a magic order of devices in the /devices chain. Specific devices
1147 should be requested by their subsytem.
1149 This will always find the scsi parent device without depending on a specific
1151 dev = sysfs_device_get(devpath);
1152 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1154 The "device" link in the current sysfs layout will be automatically
1155 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1156 parent in the devpath. If a device is requested by it's symlink, like all
1157 class devices in the new sysfs layout will look like, it gets automatically
1158 resolved and substituted with the real devpath and not the symlink path.
1161 A similar logic must be applied to _all_ sysfs users, including
1162 scripts, that search along parent devices in sysfs. The explicit use of
1163 the "device" link must be avoided. With the future sysfs layout all
1164 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1165 back to the "class" or the "bus". The layout of the parent devices in
1166 /devices is not necessarily expected to be stable across kernel releases and
1167 searching for parents by their subsystem should make sysfs users tolerant
1168 for changed parent chains.
1172 Prepare udev to work with the experimental kernel patch, that moves
1173 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1175 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1176 moving the class devices to /sys/devices.
1178 Thanks again to Marco for help finding a hopefully nice compromise
1179 to make %b simpler and working again.
1183 Complete removal of libsysfs, replaced by simple helper functions
1184 which are much simpler and a bit faster. The udev daemon operatesentirely
1185 on event parameters and does not use sysfs for simple rules anymore.
1186 Please report any new bugs/problems, that may be caused by this big
1187 change. They will be fixed immediately.
1189 The enumeration format character '%e' is deprecated and will be
1190 removed sometimes from a future udev version. It never worked correctly
1191 outside of udevstart, so we can't use it with the new parallel
1192 coldplug. A simple enumeration is as useless as the devfs naming
1193 scheme, just get rid of both if you still use it.
1195 MODALIAS and $modalias is not needed and will be removed from one of
1196 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1197 the sysfs "modalias" value.
1199 Thanks a lot to Marco for all his help on finding and fixing bugs.
1203 Let scsi_id request libata drive serial numbers from page 0x80.
1205 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1206 added /dev/disk/by-name/* for device mapper device names.
1208 Removed %e from the man page. It never worked reliably outside
1209 of udevstart and udevstart is no longer recommended to use.
1213 Symlinks are now exported to the event environment. Hopefully it's no
1214 longer needed to run udevinfo from an event process, like it was
1215 mentioned on the hotplug list:
1216 UDEV [1134776873.702967] add@/block/sdb
1219 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1223 Fix a problem if udevsend is used as the hotplug handler and tries to use
1224 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1225 and this kind of problems will hopefully go away soon.
1229 All built-in logic to work around bad sysfs timing is removed with this
1230 version. The need to wait for sysfs files is almost fixed with a kernel
1231 version that doesn't work with this udev version anyway. Until we fix
1232 the timing of the "bus" link creation, the former integrated logic should
1233 be emulated by a rule placed before all other rules:
1234 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1236 The option "udev_db" does no longer exist. All udev state will be in
1237 /$udev_root/.udev/ now, there is no longer an option to set this
1239 If the init script or something else used this value, just depend on
1240 this hardcoded path. But remember _all_content_ of this directory is
1241 still private to udev and can change at any time.
1243 Default location for rule sripts and helper programs is now: /lib/udev/.
1244 Everything that is not useful on the commandline should go into this
1245 directory. Some of the helpers in the extras folder are installed there
1246 now. The rules need to be changed, to find the helpers there.
1248 Also /lib/udev/devices is recommended as a directory where packages or
1249 the user can place real device nodes, which get copied over to /dev at
1250 every boot. This should replace the various solutions with custom config
1253 Udevsend does no longer start the udev daemon. This must be done with
1254 the init script that prepares /dev on tmpfs and creates the initial nodes,
1255 before starting the daemon.
1259 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1262 The copy of klibc is removed. A systemwide installed version of klibc
1263 should be used to build a klibc udev now.
1267 NAME="" will not create any nodes, but execute RUN keys. To completely
1268 ignore an event the OPTION "ignore_device" should be used.
1270 After removal of the reorder queue, events with a TIMEOUT can be executed
1271 without any queuing now.
1275 Fixed bug in udevd, if inotify is not available. We depend on netlink
1276 uevents now, kernels without that event source will not work with that
1277 version of udev anymore.
1281 The rule parsing happens now in the daemon once at startup, all udev
1282 event processes inherit the already parsed rules from the daemon.
1283 It is shipped with SUSE10.0 and reduces heavily the system load at
1284 startup. The option to save precompiled rules and let the udev process
1285 pick the them up is removed, as it's no longer needed.
1287 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1288 device. Libsysfs is changed to "translate" the requested link into the
1289 real device path, as it would happen with the hotplug event. Otherwise
1290 device removal and the udev database will not work.
1292 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1295 A few improvements for vol_id, the filesytem probing code.
1299 Fix a stupid typo in extras/run_directory for "make install".
1301 scsi_id creates the temporary devnode now in /dev for usage with a
1302 non-writable /tmp directory.
1304 The uevent kernel socket buffer can carry app. 50.000 events now,
1305 let's see who can break this again. :)
1307 The upcoming kernel will have a new input driver core integration.
1308 Some class devices are now symlinks to the real device. libsysfs
1309 needs a fix for this to work correctly. Udevstart of older udev
1310 versions will _not_ create these devices!
1314 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1319 A bunch of mostly trivial bugfixes. From now on no node name or
1320 symlink name can contain any character than plain whitelisted ascii
1321 characters or validated utf8 byte-streams. This is needed for the
1322 /dev/disk/by-label/* links, because we import untrusted data and
1323 export it to the filesystem.
1327 More bugfixes. If udevd was started from the kernel, we don't
1328 have stdin/stdout/stderr, which broke the forked tools in some
1333 Bugfix. udevstart event ordering was broken for a long time.
1334 The new run_program() uncovered it, because /dev/null was not
1335 available while we try to run external programs.
1336 Now udevstart should create it before we run anything.
1340 Minor bugfixes and some distro rules updates. If you don't have the
1341 persistent disk rules in /dev/disk/by-*/* on your distro, just
1342 grab it from here. :)
1346 We can use socket communication now to pass events from udev to
1348 RUN+="socket:/org/freedesktop/hal/udev_event"
1349 will pass the whole udev event to the HAL daemon without the need
1350 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1354 Mostly bugfixes and see ChangeLog.
1356 The test for the existence of an environment value should be
1358 ENV{KEY}=="*" to ENV{KEY}=="?*"
1359 because "*" will not fail anymore, if the key does not exist or
1364 Bugfixes and a few tweaks described in the ChangeLog.
1368 Mostly a Bugfix release.
1370 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1371 timing with custom rules.
1375 We changed the internal rule storage format. Our large rule files took
1376 2 MB of RAM, with the change we are down to 99kB.
1378 If the device-node has been created with default name and no symlink or
1379 options are to remenber, it is not longer stored in the udevdb. HAL will
1380 need to be updated to work correctly with that change.
1382 To overrride optimization flags, OPTFLAGS may be used now.
1390 Major changes happened with this release. The goal is to take over the
1391 complete kernel-event handling and provide a more efficient way to dispatch
1392 kernel events. Replacing most of the current shell script logic and the
1393 kernel forked helper with a netlink-daemon and a rule-based event handling.
1395 o udevd listens to netlink events now. The first valid netlink event
1396 will make udevd ignore any message from udevsend that contains a
1397 SEQNUM, to avoid duplicate events. The forked events can be disabled
1399 echo "" > /proc/sys/kernel/hotplug
1400 For full support, the broken input-subsytem needs to be fixed, not to
1401 bypass the driver core.
1403 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1404 removed from udev itself and must be emulated by calling small
1405 helper binaries provided in the extras folder:
1406 make EXTRAS=extras/run_directory/
1407 will build udev_run_devd and udev_run_hotplugd, which can be called
1408 from a rule if needed:
1409 RUN+="/sbin/udev_run_hotplugd"
1410 The recommended way to handle this is to convert all the calls from
1411 the directories to explicit udev rules and get completely rid of the
1412 multiplexing. (To catch a ttyUSB event, you now no longer need to
1413 fork and exit 300 tty script instances you are not interested in, it
1414 is just one rule that matches exactly the device.)
1416 o udev handles now _all_ events not just events for class and block
1417 devices, this way it is possible to control the complete event
1418 behavior with udev rules. Especially useful for rules like:
1419 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1421 o As used in the modalias rule, udev supports now textual
1422 substitution placeholder along with the usual format chars. This
1423 needs to be documented, for now it's only visible in udev_rules_parse.c.
1425 o The rule keys support now more operations. This is documented in the
1426 man page. It is possible to add values to list-keys like the SYMLINK
1427 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1428 Also "final"-assignments are supported by using KEY:="value", which will
1429 prevent changing the key by any later rule.
1431 o kernel 2.6.12 has the "detached_state" attribute removed from
1432 sysfs, which was used to recognize sysfs population. We switched that
1433 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1434 Running this udev version on older kernels may cause a short delay for
1437 o To provide infrastructure for persistent device naming, the id programs:
1438 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1439 to export the probed data in environment key format:
1440 pim:~ # /sbin/ata_id --export /dev/hda
1441 ID_MODEL=HTS726060M9AT00
1442 ID_SERIAL=MRH401M4G6UM9B
1443 ID_REVISION=MH4OA6BA
1445 The following rules:
1446 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1447 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1450 kay@pim:~> tree /dev/disk
1453 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1454 | `-- IBM-Memory_Key -> ../../sda
1456 | |-- swap -> ../../hda1
1457 | |-- date -> ../../sda1
1458 | `-- home -> ../../hda3
1460 |-- 2E08712B0870F2E7 -> ../../hda3
1461 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1462 |-- E845-7A89 -> ../../sda1
1463 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1465 The IMPORT= operation will import these keys in the environment and make
1466 it available for later PROGRAM= and RUN= executed programs. The keys are
1467 also stored in the udevdb and can be queried from there with one of the
1470 o A few binaries are silently added to the repository, which can be used
1471 to replay kernel events from initramfs instead of using coldplug. udevd
1472 can be instructed now to queue-up events while the stored events from
1473 initramfs are filled into the udevd-queue. This code is still under
1474 development and there is no documentation now besides the code itself.
1475 The additional binaries get compiled, but are not installed by default.
1477 o There is also a temporary fix for a performance problem where too many
1478 events happen in parallel and every event needs to parse the rules.
1479 udev can now read precompiled rules stored on disk. This is likely to be
1480 replaced by a more elegant solution in a future udev version.
1484 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1485 Fix for libsysfs not to expect this file was added.
1489 All rules are applied now, but only the first matching rule with a NAME-key
1490 will be applied. All later rules with NAME-key are completely ignored. This
1491 way system supplied symlinks or permissions gets applied to user-defined
1495 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1496 to some rules, to keep the old behavior.
1498 The rules are read on "remove"-events too. That makes is possible to match
1499 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1500 instruct udev to ignore an event (OPTIONS="ignore_device").
1501 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1503 The new RUN-key supports rule-based execution of programs after device-node
1504 handling. This is meant as a general replacement for the dev.d/-directories
1505 to give fine grained control over the execution of programs.
1507 The %s{}-sysfs format char replacement values are searched at any of the
1508 devices in the device chain now, not only at the class-device.
1510 We support log priority levels now. The value udev_log in udev.conf is used
1511 to determine what is printed to syslog. This makes it possible to
1512 run a version with compiled-in debug messages in a production environment
1513 which is sometimes needed to find a bug.
1514 It is still possible to supress the inclusion of _any_ syslog usage with
1515 USE_LOG=false to create the smallest possible binaries if needed.
1516 The configured udev_log value can be overridden with the environment variable
1521 Possible use of a system-wide klibc:
1522 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1523 will link against an external klibc and our own version will be ignored.
1527 We support an unlimited count of symlinks now.
1529 If USE_STATIC=true is passed to a glibc build, we link statically and use
1530 a built-in userdb parser to resolve user and group names.
1532 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1533 we walk up the chain of physical devices to find a match.
1535 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1536 easy to skip certain attribute matches without composing rules with weird
1537 character class negations like:
1538 KERNEL="[!s][!c][!d]*"
1539 this can now be replaced with:
1541 The current simple '=' is still supported, and should work as it does today,
1542 but existing rules should be converted if possible, to be better readable.
1544 We have new ENV{}== key now, to match against a maximum of 5 environment
1547 udevstart is its own binary again, because we don't need co carry this araound
1548 with every forked event.