5 The systemd service files require systemd version 28. The systemd
6 socket activation make it possible now to start 'udevd' and 'udevadm
11 Fix bug in control message handling, which can lead to a failing
12 udevadm control --exit. Thanks to Jürg Billeter for help tracking
19 We require at least Linux kernel 2.6.32 now. Some platforms might
20 require a later kernel that supports accept4() and similar, or
21 need to backport the trivial syscall wiring to the older kernels.
23 The hid2hci tool moved to the bluez package and was removed.
25 Many of the extras can be --enable/--disabled at ./configure
26 time. The --disable-extras option was removed. Some extras have
27 been disabled by default. The current options and their defaults
28 can be checked with './configure --help'.
34 Udev logs a warning now if /run is not writable at udevd
35 startup. It will still fall back to /dev/.udev, but this is
38 The running udev daemon can now cleanly shut down with:
39 udevadm control --exit
41 Udev in initramfs should clean the state of the udev database
42 with: udevadm info --cleanup-db which will remove all state left
43 behind from events/rules in initramfs. If initramfs uses
44 --cleanup-db and device-mapper/LVM, the rules in initramfs need
45 to add OPTIONS+="db_persist" for all dm devices. This will
46 prevent removal of the udev database for these devices.
48 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
49 120 seconds per process. If that timeout is reached the spawned
50 process will be killed. The event timeout can be overwritten with
53 If systemd is used, udev gets now activated by netlink data.
54 Systemd will bind the netlink socket which will buffer all data.
55 If needed, such setup allows a seemless update of the udev daemon,
56 where no event can be lost during a udevd update/restart.
57 Packages need to make sure to: systemctl stop udev.socket udev.service
58 or 'mask' udev.service during the upgrade to prevent any unwanted
59 auto-spawning of udevd.
60 This version of udev conflicts with systemd version below 25. The
61 unchanged service files will not wirk correctly.
67 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
68 /run mountpoint is supposed to be a tmpfs mounted during early boot,
69 available and writable to for all tools at any time during bootup,
70 it replaces /var/run/, which should become a symlink some day.
72 If /run does not exist, or is not writable, udev will fall back using
75 On systemd systems with initramfs and LVM used, packagers must
76 make sure, that the systemd and initramfs versions match. The initramfs
77 needs to create the /run mountpoint for udev to store the data, and
78 mount this tmpfs to /run in the rootfs, so the that the udev database
79 is preserved for the udev version started in the rootfs.
81 The command 'udevadm info --convert-db' is gone. The udev daemon
82 itself, at startup, converts any old database version if necessary.
84 The systemd services files have been reorganized. The udev control
85 socket is bound by systemd and passed to the started udev daemon.
86 The udev-settle.service is no longer active by default. Services which
87 can not handle hotplug setups properly need to actively pull it in, to
88 act like a barrier. Alternatively the settle service can be unconditionally
89 'systemctl'enabled, and act like a barrier for basic.target.
91 The fstab_import callout is no longer built or installed. Udev
92 should not be used to mount, does not watch changes to fstab, and
93 should not mirror fstab values in the udev database.
99 New and updated keymaps.
105 The udev database has changed, After installation of a new udev
106 version, 'udevadm info --convert-db' should be called, to let the new
107 udev/libudev version read the already stored data.
109 udevadm now supports quoting of property values, and prefixing of
111 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
114 MY_DEVNAME='/dev/sda'
118 libudev now supports:
119 udev_device_get_is_initialized()
120 udev_enumerate_add_match_is_initialized()
121 to be able to skip devices the kernel has created , but udev has
124 libudev now supports:
125 udev_device_get_usec_since_initialized()
126 to retrieve the "age" of a udev device record.
128 GUdev supports a more generic GUdevEnumerator class, udev TAG
129 handling, device initialization and timestamp now.
131 The counterpart of /sys/dev/{char,block}/$major:$minor,
132 /dev/{char,block}/$major:$minor symlinks are now unconditionally
133 created, even when no rule files exist.
135 New and updated keymaps.
141 GUdev moved from /usr to /.
151 Persistent network naming rules are disabled inside of Qemu/KVM now.
153 New and updated keymaps.
155 Udev gets unconditionally enabled on systemd installations now. There
156 is no longer the need to to run 'systemctl enable udev.service'.
170 New and fixed keymaps.
172 Install systemd service files if applicable.
178 All distribution specific rules are removed from the udev source tree,
179 most of them are no longer needed. The Gentoo rules which allow to support
180 older kernel versions, which are not covered by the default rules anymore
181 has moved to rules/misc/30-kernel-compat.rules.
187 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
188 was removed from udevd.
190 Udevd now checks the kernel commandline for the following variables:
191 udev.log-priority=<syslog priority>
192 udev.children-max=<maximum number of workers>
193 udev.exec-delay=<seconds to delay the execution of RUN=>
194 to help debuging coldplug setups where the loading of a kernel
195 module crashes the system.
197 The subdirectory in the source tree rules/packages has been renamed to
198 rules/arch, anc contains only architecture specific rules now.
208 Now the udev daemon itself, does on startup:
209 - copy the content of /lib/udev/devices to /dev
210 - create the standard symlinks like /dev/std{in,out,err},
211 /dev/core, /dev/fd, ...
212 - use static node information provided by kernel modules
213 and creates these nodes to allow module on-demand loading
214 - possibly apply permissions to all ststic nodes from udev
215 rules which are annotated to match a static node
217 The default mode for a device node is 0600 now to match the kernel
218 created devtmpfs defaults. If GROUP= is specified and no MODE= is
219 given the default will be 0660.
225 Udev now gradually starts to pass control over the primary device nodes
226 and their names to the kernel, and will in the end only manage the
227 permissions of the node, and possibly create additional symlinks.
228 As a first step NAME="" will be ignored, and NAME= setings with names
229 other than the kernel provided name will result in a logged warning.
230 Kernels that don't provide device names, or devtmpfs is not used, will
231 still work as they did before, but it is strongly recommended to use
232 only the same names for the primary device node as the recent kernel
233 provides for all devices.
237 Fix broken firmware loader search path.
243 "udevadm trigger" defaults to "change" events now instead of "add"
244 events. The "udev boot script" might need to add "--action=add" to
245 the trigger command if not already there, in case the initial coldplug
246 events are expected as "add" events.
248 The option "all_partitons" was removed from udev. This should not be
249 needed for usual hardware. Udev can not safely make assumptions
250 about non-existing partition major/minor numbers, and therefore no
251 longer provide this unreliable and unsafe option.
253 The option "ignore_remove" was removed from udev. With devtmpfs
254 udev passed control over device nodes to the kernel. This option
255 should not be needed, or can not work as advertised. Neither
256 udev nor the kernel will remove device nodes which are copied from
257 the /lib/udev/devices/ directory.
259 All "add|change" matches are replaced by "!remove" in the rules and
260 in the udev logic. All types of events will update possible symlinks
261 and permissions, only "remove" is handled special now.
263 The modem modeswitch extra was removed and the external usb_modeswitch
264 program should be used instead.
266 New and fixed keymaps.
276 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
277 depend on the current sysfs layout and the information not available in the
278 deprecated layout. All remaining support for the deprecated sysfs layout is
283 Fix for a possible endless loop in the new input_id program.
289 The option "ignore_device" does no longer exist. There is no way to
290 ignore an event, as libudev events can not be suppressed by rules.
291 It only prevented RUN keys from being executed, which results in an
292 inconsistent behavior in current setups.
294 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
295 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
298 The support for the deprecated IDE devices has been removed from the
299 default set of rules. Distros who still care about non-libata drivers
300 need to add the rules to the compat rules file.
302 The ID_CLASS property on input devices has been replaced by the more accurate
303 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
304 determined by the new "input_id" prober now. Some devices, such as touchpads,
305 can have several classes. So if you previously had custom udev rules which e. g.
306 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
307 ENV{ID_INPUT_KEYBOARD}=="?*".
313 To support DEVPATH strings larger than the maximum file name length, the
314 private udev database format has changed. If some software still reads the
315 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
316 Please do not port anything to the new format again, everything in /dev/.udev
317 is and always was private to udev, and may and will change any time without
320 Multiple devices claiming the same names in /dev are limited to symlinks
321 only now. Mixing identical symlink names and node names is not supported.
322 This reduces the amount of data in the database significantly.
324 NAME="%k" causes a warning now. It's is and always was completely superfluous.
325 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
328 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
329 if they are not the default. To support older kernels, the NAME= rules need to
330 be added to the compat rules file.
332 Symlinks to udevadm with the old command names are no longer resolved to
333 the udevadm commands.
335 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
338 The option "last_rule" does no longer exist. Its use breaks too many
339 things which expect to be run from independent later rules, and is an idication
340 that something needs to be fixed properly instead.
342 The gudev API is no longer marked as experimental,
343 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
344 is enabled by default now. Various projects already depend on introspection
345 information to bind dynamic languages to the gudev interfaces.
351 The udevadm trigger "--retry-failed" option, which is replaced since quite
352 a while by "--type=failed" is removed.
354 The failed tracking was not working at all for a few releases. The RUN
355 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
356 default is not to track any failing RUN executions.
358 New keymaps, new modem, hid2hci updated.
362 Fix possible crash in udevd when worker processes are busy, rules are
363 changed at the same time, and workers get killed to reload the rules.
369 Properties set with ENV{.FOO}="bar" are marked private by starting the
370 name with a '.'. They will not be stored in the database, and not be
371 exported with the event.
373 Firmware files are looked up in:
374 /lib/firmware/updates/$(uname -r)
375 /lib/firmware/updates
376 /lib/firmware/$(uname -r)
380 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
381 ata_id, instead of scsi_id, is the default tool now for ATA devices.
387 The configure options have changed because another library needs to be
388 installed in a different location. Instead of exec_prefix and udev_prefix,
389 libdir, rootlibdir and libexecdir are used. The Details are explained in
392 Event processes now get re-used after they handled an event. This reduces
393 the number of forks and the pressure on the CPU significantly, because
394 cloned event processes no longer cause page faults in the main daemon.
395 After the events have settled, a few worker processes stay around for
396 future events, all others get cleaned up.
398 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
399 Also inotify support is mandatory now to run udev.
401 The format of the queue exported by the udev damon has changed. There is
402 no longer a /dev/.udev/queue/ directory. The current event queue can be
403 accessed with udevadm settle and libudedv.
405 Libudev does not have the unstable API header anymore. From now on,
406 incompatible changes will be handled by bumping the library major version.
408 To build udev from the git tree gtk-doc is needed now. The tarballs will
409 build without it and contain the pre-built documentation. An online copy
411 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
413 The tools from the udev-extras repository have been merged into the main
414 udev repository. Some of the extras have larger external dependencies, and
415 they can be disabled with the configure switch --disable-extras.
421 The program vol_id and the library libvolume_id are removed from the
422 repository. Libvolume_id is merged with libblkid from the util-linux-ng
423 package. Persistent disk links for label and uuid depend on the
424 util-linux-ng version (2.15) of blkid now. Older versions of blkid
425 can not be used with udev.
427 Libudev allows to subscribe to udev events. To prevent unwanted messages
428 to be delivered, and waking up the subscribing process, a filter can be
429 installed, to drop messages inside a kernel socket filter. The filters
430 match on the <subsytem>:<devtype> properties of the device.
431 This is part of the ongoing effort to replace HAL, and switch current
432 users over to directly use libudev.
433 Libudev is still marked as experimental, and its interface might
434 eventually change if needed, but no major changes of the currently exported
435 interface are expected anymore, and a first stable release should happen
438 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
439 is not supported since while and udevd will log an error message at
440 startup. It should still be able to boot-up, but advanced rules and system
441 services which depend on the information not available in the old sysfs
442 format will fail to work correctly.
444 DVB device naming is supplied by the kernel now. In case older kernels
445 need to be supported, the old shell script should be added to a compat
452 The processed udev events get send back to the netlink socket. Libudev
453 provides access to these events. This is work-in-progress, to replace
454 the DeviceKit daemon functionality directly with libudev. There are
455 upcoming kernel changes to allow non-root users to subcribe to these
462 "udevadm settle" now optionally accepts a range of events to wait for,
463 instead of waiting for "all" events.
469 The installed watch for block device metadata changes is now removed
470 during event hadling, because some (broken) tools may be called from udev
471 rules and (wrongly) open the device with write access. After the finished
472 event handling the watch is restored.
478 Device nodes can be watched for changes with inotify with OPTIONS="watch".
479 If closed after being opened for writing, a "change" uevent will occur.
480 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
486 The udevadm test command has no longer a --force option, nodes and symlinks
487 are always updated with a test run now.
489 The udevd daemon can be started with --resolve-names=never to avoid all user
490 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
491 lookup user and groups every time events are handled.
497 We are currently merging the Ubuntu rules in the udev default rules,
498 and get one step closer to provide a common Linux /dev setup, regarding
499 device names, symlinks, and default device permissions. On udev startup,
500 we now expect the following groups to be resolvable to their ids with
502 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
503 LDAP setups need to make sure, that these groups are always resolvable at
504 bootup, with only the rootfs mounted, and without network access available.
506 Some systems may need to add some new, currently not used groups, or need
507 to add some users to new groups, but the cost of this change is minimal,
508 compared to the pain the current, rather random, differences between the
509 various distributions cause for upstream projects and third-party vendors.
511 In general, "normal" users who log into a machine should never be a member
512 of any such group, but the device-access should be managed by dynamic ACLs,
513 which get added and removed for the specific users on login/logout and
514 session activity/inactivity. These groups are only provided for custom setups,
515 and mainly system services, to allow proper privilege separation.
516 A video-streaming daemon uid would be a member of "audio" and "video", to get
517 access to the sound and video devices, but no "normal" user should ever belong
518 to the "audio" group, because he could listen to the built-in microphone with
519 any ssh-session established from the other side of the world.
521 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
522 which do not depend on the kernel device name. As usual, unique
523 devices - only a single one per product connected, or a real
524 USB serial number in the device - are always found with the same
525 name in the by-id/ directory.
526 Completely identical devices may overwrite their names in by-id/
527 and can only be found reliably in the by-path/ directory. Devices
528 specified by by-path/ must not change their connection, like the
529 USB port number they are plugged in, to keep their name.
531 To support some advanced features, Linux 2.6.22 is the oldest supported
532 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
533 supported. Older kernels should still work, and devices nodes should be
534 reliably created, but some rules and libudev will not work correctly because
535 the old kernels do not provide the expected information or interfaces.
541 Fix for a possible segfault while swapping network interface names in udev
548 The group "video" is part of the default rules now.
552 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
553 block devices in some cases. No common distro uses this option anymore,
554 and we do not get enough testing for this and recent udev versions. If
555 this option is not needed to run some old distro with a new kernel,
556 it should be disabled in the kernel config.
558 Bugfix for the $links substitution variable, which may crash if no links
559 are created. This should not happen in usual setups because we always
560 create /dev/{block,char}/ links.
562 The strings of the parsed rules, which are kept in memory, no longer
563 contain duplicate entries, or duplicate tails of strings. This, and the
564 new rules parsing/matching code reduces the total in-memory size of
565 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
568 The export of DEVTYPE=disk/partition got removed from the default
569 rules. This value is available from the kernel. The pnp shell script
570 modprobe hack is removed from the default rules. ACPI devices have _proper_
571 modalias support and take care of the same functionality.
572 Installations which support old kernels, but install current default
573 udev rules may want to add that to the compat rules file.
575 Libvolume_id now always probes for all known filesystems, and does not
576 stop at the first match. Some filesystems are marked as "exclusive probe",
577 and if any other filesytem type matches at the same time, libvolume_id
578 will, by default, not return any probing result. This is intended to prevent
579 mis-detection with conflicting left-over signatures found from earlier
580 file system formats. That way, we no longer depend on the probe-order
581 in case of multiple competing signatures. In some setups the kernel allows
582 to mount a volume with just the old filesystem signature still in place.
583 This may damage the new filesystem and cause data-loss, just by mounting
584 it. Because volume_id can not decide which one the correct signature is,
585 the wrong signatures need to be removed manually from the volume, or the
586 volume needs to be reformatted, to enable filesystem detection and possible
591 Fix segfault if compiled without optimization and dbg() does not get
592 compiled out and uses variables which are not available.
596 Bugfixes. (And maybe new bugs. :))
598 The rule matching engine got converted from a rule list to a token
599 array which reduced the in-memory rules representation of a full
600 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
601 Limits like 5 ENV and ATTR matches, and one single instance for most
602 other keys per rule are gone.
604 The NAME assignment is no longer special cased. If later rules assign
605 a NAME value again, the former value will be overwritten. As usual
606 for most other keys, the NAME value can be protected by doing a final
607 assignment with NAME:="<value>".
609 All udev code now uses libudev, which is also exported. The library
610 is still under development, marked as experimental, and its interface
611 may change as long as the DeviceKit integration is not finished.
613 Many thanks to Alan Jenkins for his continuous help, and finding and
614 optimizing some of the computing expensive parts.
620 Kernel devices and device nodes are connected now by reverse indizes in
621 /sys and /dev. A device number retrieved by a stat() or similar, the
622 kernel device directory can be found by looking up:
623 /sys/dev/{block,char}/<maj>:<min>
624 and the device node of the same device by looking up:
625 /dev/{block,char}/<maj>:<min>
629 Fix recently introduced bug, which caused a compilation without large
630 file support, where vol_id does not recognize raid signatures at the end
633 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
634 Seems some kernel versions prevent the creation of the ieee-* links,
635 so people used the scsi-* link which disappeared now.
637 More libudev work. Almost all udevadm functionality comes from libudev
640 udevadm trigger has a new option --type, which allows to trigger events
641 for "devices", for "subsystems", or "failed" devices. The old option
642 --retry-failed" still works, but is no longer mentioned in the man page.
648 The udevadm info --device-id-of-file= output has changed to use
649 the obvious format. Possible current users should use the --export
650 option which is not affected.
652 The old udev commands symlinks to udevadm are not installed, if
653 these symlinks are used, a warning is printed.
659 Optical drive's media is no longer probed for raid signatures,
660 reading the end of the device causes some devices to malfunction.
661 Also the offset of the last session found is used now to probe
664 The volume_id library got a major version number update to 1,
665 some deprecated functions are removed.
667 A shared library "libudev" gets installed now to provide access
668 to udev device information. DeviceKit, the successor of HAL, will
669 need this library to access the udev database and search sysfs for
671 The library is currently in an experimental state, also the API is
672 expected to change, as long as the DeviceKit integration is not
677 We use ./configure now. See INSTALL for details. Current
680 "/usr" - prefix for man pages, include files
682 "" - the root filesystem, prefix for libs and binaries
686 "lib" - directory name for libraries, not a path name
687 multilib 64bit systems may use "lib64" instead of "lib"
689 compile-in verbose debug messages
691 disable all logging and compile-out all log strings
693 link against SELInux libraries, to set the expected context
696 In the default rules, the group "disk" gets permissions 0660 instead
697 of 0640. One small step closer to unify distro rules. Some day, all
698 distros hopefully end up with the same set of rules.
700 No symlinks to udevadm are installed anymore, if they are still needed,
701 they should be provided by the package.
707 Default udev rules, which are not supposed to be edited by the user, should
708 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
709 the udev package and will be replaced with an update. Udev will pick up rule
711 /lib/udev/rules.d/ - default installed rules
712 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
713 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
714 It does not matter in which directory a rule file lives, all files are sorted
717 To help creating /dev/root, we have now:
718 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
721 In case the current --device-id-of-file is already used, please switch to
722 the --export format version, it saves the output parsing and the old
723 format will be changed to use ':' as a separator, like the format in the
728 Fix cdrom_id to properly recognize blank media.
734 Tape drive id-data is queried from /dev/bsg/* instead of the tape
735 nodes. This avoids rewinding tapes on open().
741 The symlinks udevcontrol and udevtrigger are no longer installed by
744 The scsi_id program does not depend on sysfs anymore. It can speak
745 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
746 data, which should solve some old problems with tape devices, where
747 we better do not open all tape device nodes to identify the device.
753 The cdrom_id program is replaced by an advanced version, which can
754 detect most common device types, and also properties of the inserted
755 media. This is part of moving some basic functionality from HAL into
756 udev (and the kernel).
762 The last WAIT_FOR_SYSFS rule is removed from the default rules.
764 The symlinks to udevadm for the debugging tools: udevmonitor and
765 udevtest are no longer created.
767 The symlinks to the udevadm man page for the old tool names are
770 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
771 should be prefixed with '@' to indicate that the path is not a
782 Udevstart is removed from the tree, it did not get installed for
783 a long time now, and is long replaced by trigger and settle.
789 All udev tools are merged into a single binary called udevadm.
790 The old names of the tools are built-in commands in udevadm now.
791 Symlinks to udevadm, with the names of the old tools, provide
792 the same functionality as the standalone tools. There is also
793 only a single udevadm.8 man page left for all tools.
795 Tools like mkinitramfs should be checked, if they need to include
796 udevadm in the list of files.
806 The etc/udev/rules.d/ directory now contains a default set of basic
807 udev rules. This initial version is the result of a rules file merge
808 of Fedora and openSUSE. For these both distros only a few specific
809 rules are left in their own file, named after the distro. Rules which
810 are optionally installed, because they are only valid for a specific
811 architecture, or rules for subsystems which are not always used are
812 in etc/udev/packages/.
818 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
819 actions by dynamically created rules.
821 SYMLINK=="<value>" matches agains the entries in the list of
822 currently defined symlinks. The links are not created in the
823 filesystem at that point in time, but the values can be matched.
825 RUN{ignore_error}+="<program>" will ignore any exit code from the
826 program and not record as a failed event.
832 Final merge of patches/features from the Ubuntu package.
838 Control characters in filesystem label strings are no longer silenty
839 removed, but hex-encoded, to be able to uniquely identify the device
840 by its symlink in /dev/disk/by-label/.
841 If libvolume_id is used by mount(8), LABEL= will work as expected,
842 if slashes or other characters are used in the label string.
844 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
845 can be specified now. The TEST key accepts an optional mode mask
846 TEST{0100}=="<is executable file>".
848 Scsi_id now supports a mode without expecting scsi-specific sysfs
849 entries to allow the extraction of cciss-device persistent properties.
855 In the future, we may see uuid's which are just simple character
856 strings (see the DDF Raid Specification). For that reason vol_id now
857 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
858 the creation of symlinks, the *_SAFE values ensure, that no control
859 or whitespace characters are used in the filename.
861 Possible users of libvolume_id, please use the volume_id_get_* functions.
862 The public struct will go away in a future release of the library.
868 Removal of useless extras/eventrecorder.sh.
878 The directory multiplexer for dev.d/ and hotplug.d are finally removed
879 from the udev package.
885 Symlinks can have priorities now, the priority is assigned to the device
886 and specified with OPTIONS="link_priority=100". Devices with higher
887 priorities overwrite the symlinks of devices with lower priorities.
888 If the device that currently owns the link, goes away, the symlink
889 will be removed, and recreated, pointing to the next device with the
890 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
891 more reliable, if multiple devices contain the same metadata and overwrite
894 The dasd_id program is removed from the udev tree, and dasdinfo, with the
895 needed rules, are part of the s390-tools now.
897 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
898 we may get the scsi sysfs mess fixed some day, and this will only catch
899 the devices we are looking for.
901 USB serial numbers for storage devices have the target:lun now appended,
902 to make it possibble to distinguish broken multi-lun devices with all
903 the same SCSI identifiers.
905 Note: The extra "run_directory" which searches and executes stuff in
906 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
907 with the next release. Make sure, that you don't use it anymore, or
908 provides your own implementation of that inefficient stuff.
909 We are tired of reports about a "slow udev", because these directories
910 contain stuff, that runs with _every_ event, instead of using rules,
911 that run programs only for the matching events.
921 DRIVER== will match only for devices that actually have a real
922 driver. DRIVERS== must be used, if parent devices should be
923 included in the match.
925 Libvolume_id's "linux_raid" detection needed another fix.
933 Add additional check to volume_id detection of via_raid, cause
934 some company decided to put a matching pattern all over the empty
935 storage area of their music players.
939 Fix path_id for SAS devices.
943 The udev daemon can be started with --debug-trace now, which will
944 execute all events serialized to get a chance to catch a possible
945 action that crashes the box.
947 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
948 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
949 are excluded from the warning. Referencing parent attributes directly
950 may break when something in the kernel driver model changes. Udev will
951 just find the attribute by walking up the parent chain.
953 Udevtrigger now sorts the list of devices depending on the device
954 dependency, so a "usb" device is triggered after the parent "pci"
959 Revert persistent-storage ata-serial '_' '-' replacement.
965 Udevtrigger can now filter the list of devices to be triggered. Matches
966 for subsystems or sysfs attributes can be specified.
968 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
969 zero-sized files to avoid pointing to /sys and confuse broken tools which
970 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
973 The rules and scripts to create udev rules for persistent network
974 devices and optical drives are in the extras/rules_generator directory
975 now. If you use something similar, please consider replacing your own
976 version with this, to share the support effort. The rule_generator
977 installs its own rules into /etc/udev/rules.d.
979 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
980 the rule_generator depends on cdrom_id to be called in an earlier rule.
986 Renaming of some key names (the old names still work):
987 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
988 (The behavior of the key DRIVER will change soon in one of the next
989 releases, to match only the event device, please switch to DRIVERS
990 instead. If DRIVER is used, it will behave like DRIVERS, but an error
992 With the new key names, we have a more consistent and simpler scheme.
993 We can match the properties of the event device only, with: KERNEL,
994 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
995 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
996 longer mentioned in the man page and should be switched in the rule
999 ATTR{file}="value" can be used now, to write to a sysfs file of the
1000 event device. Instead of:
1001 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1003 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1005 All the PHYSDEV* keys are deprecated and will be removed from a
1007 PHYDEVPATH - is the path of a parent device and should not be
1009 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1010 matched with SUBSYSTEMS==
1011 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1012 Newer kernels will have DRIVER in the environment,
1013 for older kernels udev puts in. Class device will
1014 no longer carry this property of a parent and
1015 DRIVERS== can be used to match such a parent value.
1016 Note that ENV{DRIVER} is only available for a few bus devices, where
1017 the driver is already bound at device event time. On coldplug, the
1018 events for a lot devices are already bound to a driver, and they will have
1019 that value set. But on hotplug, at the time the kernel creates the device,
1020 it can't know what driver may claim the device after that, therefore
1021 in most cases it will be empty.
1023 Failed events should now be re-triggered with:
1024 udevtrigger --retry-failed.
1025 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1026 files private to the udev tools. We may need to switch the current symlink
1027 target, cause some obviously broken tools try to scan all files in /dev
1028 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1029 million times. This takes ages on slow boxes.
1031 The udevinfo attribute walk (-a) now works with giving a device node
1032 name (-n) instead of a devpath (-p). The query now always works, also when
1033 no database file was created by udev.
1035 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1036 getpwnam() and getgrnam() now. One of the next releases will depend on
1037 fnmatch() and may use getopt_long().
1041 Bugfixes and small improvements.
1045 Fix path_id for recent kernels.
1051 Added support for swapping network interface names, by temporarily
1052 renaming the device and wait for the target name to become free.
1056 The built-in MODALIAS key and substitution is removed.
1060 The binary firmware helper is replaced by the usual simple
1061 shell script. Udevsend is removed from the tree.
1069 Some more keys require the correct use of '==' and '=' depending
1070 on the kind of operation beeing an assignment or a match. Rules
1071 with invalid operations are skipped and logged to syslog. Please
1072 test with udevtest if the parsing of your rules throws errors and
1073 fix possibly broken rules.
1077 Provide "udevsettle" to wait for all current udev events to finish.
1078 It also watches the current kernel netlink queue by comparing the
1079 even sequence number to make sure that there are no current pending
1080 events that have not already arrived in the daemon.
1084 Fix rule to skip persistent rules for removable IDE devices, which
1085 also skipped optical IDE drives.
1087 All *_id program are installed in /lib/udev/ by default now.
1089 No binary is stripped anymore as this should be done in the
1090 packaging process and not at build time.
1092 libvolume_id is provided as a shared library now and vol_id is
1093 linked against it. Also one of the next HAL versions will require
1094 this library, and the HAL build process will also require the
1095 header file to be installed. The copy of the same code in HAL will
1096 be removed to have only a single copy left on the system.
1100 Add persistent links for SCSI tapes. The rules file is renamed
1101 to 60-persistent-storage.rules.
1103 Create persistent path for usb devices. Can be used for all sorts
1104 of devices that can't be distinguished by other properties like
1105 multiple identical keyboards and mice connected to the same box.
1107 Provide "udevtrigger" program to request events on coldplug. The
1108 shell script is much too slow with thousends of devices.
1112 Fix persistent disk rules to exclude removable IDE drives.
1114 Warn if %e, $modalias or MODALIAS is used.
1118 Fix queue export, which wasn't correct for subsequent add/remove
1119 events for the same device.
1123 Fix cramfs detection on big endian.
1125 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1130 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1131 attributes were only checked at the parent device that matched the
1132 by BUS requested subsystem. Fix it to also look at the device we
1133 received the event for.
1135 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1140 Fix a bug where NAME="" would prevent RUN from beeing executed.
1142 RUN="/bin/program" does not longer automatically add the subsystem
1143 as the first parameter. This is from the days of /sbin/hotplug
1144 which is dead now and it's just confusing to need to add a space at
1145 the end of the program name to prevent this.
1146 If you use rules that need the subsystem as the first parameter,
1147 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1148 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1152 The udev man page has moved to udev(7) as it does not describe a command
1153 anymore. The programs udev, udevstart and udevsend are no longer installed
1154 by default and must be copied manually, if they should be installed or
1155 included in a package.
1157 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1158 the ignore rule was applied.
1160 More preparation for future sysfs changes. usb_id and scsi_id no longer
1161 depend on a magic order of devices in the /devices chain. Specific devices
1162 should be requested by their subsytem.
1164 This will always find the scsi parent device without depending on a specific
1166 dev = sysfs_device_get(devpath);
1167 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1169 The "device" link in the current sysfs layout will be automatically
1170 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1171 parent in the devpath. If a device is requested by it's symlink, like all
1172 class devices in the new sysfs layout will look like, it gets automatically
1173 resolved and substituted with the real devpath and not the symlink path.
1176 A similar logic must be applied to _all_ sysfs users, including
1177 scripts, that search along parent devices in sysfs. The explicit use of
1178 the "device" link must be avoided. With the future sysfs layout all
1179 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1180 back to the "class" or the "bus". The layout of the parent devices in
1181 /devices is not necessarily expected to be stable across kernel releases and
1182 searching for parents by their subsystem should make sysfs users tolerant
1183 for changed parent chains.
1187 Prepare udev to work with the experimental kernel patch, that moves
1188 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1190 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1191 moving the class devices to /sys/devices.
1193 Thanks again to Marco for help finding a hopefully nice compromise
1194 to make %b simpler and working again.
1198 Complete removal of libsysfs, replaced by simple helper functions
1199 which are much simpler and a bit faster. The udev daemon operatesentirely
1200 on event parameters and does not use sysfs for simple rules anymore.
1201 Please report any new bugs/problems, that may be caused by this big
1202 change. They will be fixed immediately.
1204 The enumeration format character '%e' is deprecated and will be
1205 removed sometimes from a future udev version. It never worked correctly
1206 outside of udevstart, so we can't use it with the new parallel
1207 coldplug. A simple enumeration is as useless as the devfs naming
1208 scheme, just get rid of both if you still use it.
1210 MODALIAS and $modalias is not needed and will be removed from one of
1211 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1212 the sysfs "modalias" value.
1214 Thanks a lot to Marco for all his help on finding and fixing bugs.
1218 Let scsi_id request libata drive serial numbers from page 0x80.
1220 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1221 added /dev/disk/by-name/* for device mapper device names.
1223 Removed %e from the man page. It never worked reliably outside
1224 of udevstart and udevstart is no longer recommended to use.
1228 Symlinks are now exported to the event environment. Hopefully it's no
1229 longer needed to run udevinfo from an event process, like it was
1230 mentioned on the hotplug list:
1231 UDEV [1134776873.702967] add@/block/sdb
1234 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1238 Fix a problem if udevsend is used as the hotplug handler and tries to use
1239 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1240 and this kind of problems will hopefully go away soon.
1244 All built-in logic to work around bad sysfs timing is removed with this
1245 version. The need to wait for sysfs files is almost fixed with a kernel
1246 version that doesn't work with this udev version anyway. Until we fix
1247 the timing of the "bus" link creation, the former integrated logic should
1248 be emulated by a rule placed before all other rules:
1249 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1251 The option "udev_db" does no longer exist. All udev state will be in
1252 /$udev_root/.udev/ now, there is no longer an option to set this
1254 If the init script or something else used this value, just depend on
1255 this hardcoded path. But remember _all_content_ of this directory is
1256 still private to udev and can change at any time.
1258 Default location for rule sripts and helper programs is now: /lib/udev/.
1259 Everything that is not useful on the commandline should go into this
1260 directory. Some of the helpers in the extras folder are installed there
1261 now. The rules need to be changed, to find the helpers there.
1263 Also /lib/udev/devices is recommended as a directory where packages or
1264 the user can place real device nodes, which get copied over to /dev at
1265 every boot. This should replace the various solutions with custom config
1268 Udevsend does no longer start the udev daemon. This must be done with
1269 the init script that prepares /dev on tmpfs and creates the initial nodes,
1270 before starting the daemon.
1274 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1277 The copy of klibc is removed. A systemwide installed version of klibc
1278 should be used to build a klibc udev now.
1282 NAME="" will not create any nodes, but execute RUN keys. To completely
1283 ignore an event the OPTION "ignore_device" should be used.
1285 After removal of the reorder queue, events with a TIMEOUT can be executed
1286 without any queuing now.
1290 Fixed bug in udevd, if inotify is not available. We depend on netlink
1291 uevents now, kernels without that event source will not work with that
1292 version of udev anymore.
1296 The rule parsing happens now in the daemon once at startup, all udev
1297 event processes inherit the already parsed rules from the daemon.
1298 It is shipped with SUSE10.0 and reduces heavily the system load at
1299 startup. The option to save precompiled rules and let the udev process
1300 pick the them up is removed, as it's no longer needed.
1302 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1303 device. Libsysfs is changed to "translate" the requested link into the
1304 real device path, as it would happen with the hotplug event. Otherwise
1305 device removal and the udev database will not work.
1307 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1310 A few improvements for vol_id, the filesytem probing code.
1314 Fix a stupid typo in extras/run_directory for "make install".
1316 scsi_id creates the temporary devnode now in /dev for usage with a
1317 non-writable /tmp directory.
1319 The uevent kernel socket buffer can carry app. 50.000 events now,
1320 let's see who can break this again. :)
1322 The upcoming kernel will have a new input driver core integration.
1323 Some class devices are now symlinks to the real device. libsysfs
1324 needs a fix for this to work correctly. Udevstart of older udev
1325 versions will _not_ create these devices!
1329 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1334 A bunch of mostly trivial bugfixes. From now on no node name or
1335 symlink name can contain any character than plain whitelisted ascii
1336 characters or validated utf8 byte-streams. This is needed for the
1337 /dev/disk/by-label/* links, because we import untrusted data and
1338 export it to the filesystem.
1342 More bugfixes. If udevd was started from the kernel, we don't
1343 have stdin/stdout/stderr, which broke the forked tools in some
1348 Bugfix. udevstart event ordering was broken for a long time.
1349 The new run_program() uncovered it, because /dev/null was not
1350 available while we try to run external programs.
1351 Now udevstart should create it before we run anything.
1355 Minor bugfixes and some distro rules updates. If you don't have the
1356 persistent disk rules in /dev/disk/by-*/* on your distro, just
1357 grab it from here. :)
1361 We can use socket communication now to pass events from udev to
1363 RUN+="socket:/org/freedesktop/hal/udev_event"
1364 will pass the whole udev event to the HAL daemon without the need
1365 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1369 Mostly bugfixes and see ChangeLog.
1371 The test for the existence of an environment value should be
1373 ENV{KEY}=="*" to ENV{KEY}=="?*"
1374 because "*" will not fail anymore, if the key does not exist or
1379 Bugfixes and a few tweaks described in the ChangeLog.
1383 Mostly a Bugfix release.
1385 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1386 timing with custom rules.
1390 We changed the internal rule storage format. Our large rule files took
1391 2 MB of RAM, with the change we are down to 99kB.
1393 If the device-node has been created with default name and no symlink or
1394 options are to remenber, it is not longer stored in the udevdb. HAL will
1395 need to be updated to work correctly with that change.
1397 To overrride optimization flags, OPTFLAGS may be used now.
1405 Major changes happened with this release. The goal is to take over the
1406 complete kernel-event handling and provide a more efficient way to dispatch
1407 kernel events. Replacing most of the current shell script logic and the
1408 kernel forked helper with a netlink-daemon and a rule-based event handling.
1410 o udevd listens to netlink events now. The first valid netlink event
1411 will make udevd ignore any message from udevsend that contains a
1412 SEQNUM, to avoid duplicate events. The forked events can be disabled
1414 echo "" > /proc/sys/kernel/hotplug
1415 For full support, the broken input-subsytem needs to be fixed, not to
1416 bypass the driver core.
1418 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1419 removed from udev itself and must be emulated by calling small
1420 helper binaries provided in the extras folder:
1421 make EXTRAS=extras/run_directory/
1422 will build udev_run_devd and udev_run_hotplugd, which can be called
1423 from a rule if needed:
1424 RUN+="/sbin/udev_run_hotplugd"
1425 The recommended way to handle this is to convert all the calls from
1426 the directories to explicit udev rules and get completely rid of the
1427 multiplexing. (To catch a ttyUSB event, you now no longer need to
1428 fork and exit 300 tty script instances you are not interested in, it
1429 is just one rule that matches exactly the device.)
1431 o udev handles now _all_ events not just events for class and block
1432 devices, this way it is possible to control the complete event
1433 behavior with udev rules. Especially useful for rules like:
1434 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1436 o As used in the modalias rule, udev supports now textual
1437 substitution placeholder along with the usual format chars. This
1438 needs to be documented, for now it's only visible in udev_rules_parse.c.
1440 o The rule keys support now more operations. This is documented in the
1441 man page. It is possible to add values to list-keys like the SYMLINK
1442 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1443 Also "final"-assignments are supported by using KEY:="value", which will
1444 prevent changing the key by any later rule.
1446 o kernel 2.6.12 has the "detached_state" attribute removed from
1447 sysfs, which was used to recognize sysfs population. We switched that
1448 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1449 Running this udev version on older kernels may cause a short delay for
1452 o To provide infrastructure for persistent device naming, the id programs:
1453 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1454 to export the probed data in environment key format:
1455 pim:~ # /sbin/ata_id --export /dev/hda
1456 ID_MODEL=HTS726060M9AT00
1457 ID_SERIAL=MRH401M4G6UM9B
1458 ID_REVISION=MH4OA6BA
1460 The following rules:
1461 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1462 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1465 kay@pim:~> tree /dev/disk
1468 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1469 | `-- IBM-Memory_Key -> ../../sda
1471 | |-- swap -> ../../hda1
1472 | |-- date -> ../../sda1
1473 | `-- home -> ../../hda3
1475 |-- 2E08712B0870F2E7 -> ../../hda3
1476 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1477 |-- E845-7A89 -> ../../sda1
1478 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1480 The IMPORT= operation will import these keys in the environment and make
1481 it available for later PROGRAM= and RUN= executed programs. The keys are
1482 also stored in the udevdb and can be queried from there with one of the
1485 o A few binaries are silently added to the repository, which can be used
1486 to replay kernel events from initramfs instead of using coldplug. udevd
1487 can be instructed now to queue-up events while the stored events from
1488 initramfs are filled into the udevd-queue. This code is still under
1489 development and there is no documentation now besides the code itself.
1490 The additional binaries get compiled, but are not installed by default.
1492 o There is also a temporary fix for a performance problem where too many
1493 events happen in parallel and every event needs to parse the rules.
1494 udev can now read precompiled rules stored on disk. This is likely to be
1495 replaced by a more elegant solution in a future udev version.
1499 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1500 Fix for libsysfs not to expect this file was added.
1504 All rules are applied now, but only the first matching rule with a NAME-key
1505 will be applied. All later rules with NAME-key are completely ignored. This
1506 way system supplied symlinks or permissions gets applied to user-defined
1510 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1511 to some rules, to keep the old behavior.
1513 The rules are read on "remove"-events too. That makes is possible to match
1514 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1515 instruct udev to ignore an event (OPTIONS="ignore_device").
1516 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1518 The new RUN-key supports rule-based execution of programs after device-node
1519 handling. This is meant as a general replacement for the dev.d/-directories
1520 to give fine grained control over the execution of programs.
1522 The %s{}-sysfs format char replacement values are searched at any of the
1523 devices in the device chain now, not only at the class-device.
1525 We support log priority levels now. The value udev_log in udev.conf is used
1526 to determine what is printed to syslog. This makes it possible to
1527 run a version with compiled-in debug messages in a production environment
1528 which is sometimes needed to find a bug.
1529 It is still possible to supress the inclusion of _any_ syslog usage with
1530 USE_LOG=false to create the smallest possible binaries if needed.
1531 The configured udev_log value can be overridden with the environment variable
1536 Possible use of a system-wide klibc:
1537 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1538 will link against an external klibc and our own version will be ignored.
1542 We support an unlimited count of symlinks now.
1544 If USE_STATIC=true is passed to a glibc build, we link statically and use
1545 a built-in userdb parser to resolve user and group names.
1547 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1548 we walk up the chain of physical devices to find a match.
1550 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1551 easy to skip certain attribute matches without composing rules with weird
1552 character class negations like:
1553 KERNEL="[!s][!c][!d]*"
1554 this can now be replaced with:
1556 The current simple '=' is still supported, and should work as it does today,
1557 but existing rules should be converted if possible, to be better readable.
1559 We have new ENV{}== key now, to match against a maximum of 5 environment
1562 udevstart is its own binary again, because we don't need co carry this araound
1563 with every forked event.