5 We require at least Linux kernel 2.6.32 now. Some platforms might
6 require a later kernel that supports accept4() and similar, or
7 need to backport the trivial syscall wiring to the older kernels.
9 The hid2hci tool moved to the bluez package and was removed.
11 Many of the extras can be --enable/--disabled at ./configure
12 time. The --disable-extras option was removed. Some extras have
13 been disabled by default. The current options and their defaults
14 can be checked with './configure --help'.
20 Udev logs a warning now if /run is not writable at udevd
21 startup. It will still fall back to /dev/.udev, but this is
24 The running udev daemon can now cleanly shut down with:
25 udevadm control --exit
27 Udev in initramfs should clean the state of the udev database
28 with: udevadm info --cleanup-db which will remove all state left
29 behind from events/rules in initramfs. If initramfs uses
30 --cleanup-db and device-mapper/LVM, the rules in initramfs need
31 to add OPTIONS+="db_persist" for all dm devices. This will
32 prevent removal of the udev database for these devices.
34 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
35 120 seconds per process. If that timeout is reached the spawned
36 process will be killed. The event timeout can be overwritten with
39 If systemd is used, udev gets now activated by netlink data.
40 Systemd will bind the netlink socket which will buffer all data.
41 If needed, such setup allows a seemless update of the udev daemon,
42 where no event can be lost during a udevd update/restart.
43 Packages need to make sure to: systemctl stop udev.socket udev.service
44 or 'mask' udev.service during the upgrade to prevent any unwanted
45 auto-spawning of udevd.
46 This version of udev conflicts with systemd version below 25. The
47 unchanged service files will not wirk correctly.
53 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
54 /run mountpoint is supposed to be a tmpfs mounted during early boot,
55 available and writable to for all tools at any time during bootup,
56 it replaces /var/run/, which should become a symlink some day.
58 If /run does not exist, or is not writable, udev will fall back using
61 On systemd systems with initramfs and LVM used, packagers must
62 make sure, that the systemd and initramfs versions match. The initramfs
63 needs to create the /run mountpoint for udev to store the data, and
64 mount this tmpfs to /run in the rootfs, so the that the udev database
65 is preserved for the udev version started in the rootfs.
67 The command 'udevadm info --convert-db' is gone. The udev daemon
68 itself, at startup, converts any old database version if necessary.
70 The systemd services files have been reorganized. The udev control
71 socket is bound by systemd and passed to the started udev daemon.
72 The udev-settle.service is no longer active by default. Services which
73 can not handle hotplug setups properly need to actively pull it in, to
74 act like a barrier. Alternatively the settle service can be unconditionally
75 'systemctl'enabled, and act like a barrier for basic.target.
77 The fstab_import callout is no longer built or installed. Udev
78 should not be used to mount, does not watch changes to fstab, and
79 should not mirror fstab values in the udev database.
85 New and updated keymaps.
91 The udev database has changed, After installation of a new udev
92 version, 'udevadm info --convert-db' should be called, to let the new
93 udev/libudev version read the already stored data.
95 udevadm now supports quoting of property values, and prefixing of
97 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
100 MY_DEVNAME='/dev/sda'
104 libudev now supports:
105 udev_device_get_is_initialized()
106 udev_enumerate_add_match_is_initialized()
107 to be able to skip devices the kernel has created , but udev has
110 libudev now supports:
111 udev_device_get_usec_since_initialized()
112 to retrieve the "age" of a udev device record.
114 GUdev supports a more generic GUdevEnumerator class, udev TAG
115 handling, device initialization and timestamp now.
117 The counterpart of /sys/dev/{char,block}/$major:$minor,
118 /dev/{char,block}/$major:$minor symlinks are now unconditionally
119 created, even when no rule files exist.
121 New and updated keymaps.
127 GUdev moved from /usr to /.
137 Persistent network naming rules are disabled inside of Qemu/KVM now.
139 New and updated keymaps.
141 Udev gets unconditionally enabled on systemd installations now. There
142 is no longer the need to to run 'systemctl enable udev.service'.
156 New and fixed keymaps.
158 Install systemd service files if applicable.
164 All distribution specific rules are removed from the udev source tree,
165 most of them are no longer needed. The Gentoo rules which allow to support
166 older kernel versions, which are not covered by the default rules anymore
167 has moved to rules/misc/30-kernel-compat.rules.
173 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
174 was removed from udevd.
176 Udevd now checks the kernel commandline for the following variables:
177 udev.log-priority=<syslog priority>
178 udev.children-max=<maximum number of workers>
179 udev.exec-delay=<seconds to delay the execution of RUN=>
180 to help debuging coldplug setups where the loading of a kernel
181 module crashes the system.
183 The subdirectory in the source tree rules/packages has been renamed to
184 rules/arch, anc contains only architecture specific rules now.
194 Now the udev daemon itself, does on startup:
195 - copy the content of /lib/udev/devices to /dev
196 - create the standard symlinks like /dev/std{in,out,err},
197 /dev/core, /dev/fd, ...
198 - use static node information provided by kernel modules
199 and creates these nodes to allow module on-demand loading
200 - possibly apply permissions to all ststic nodes from udev
201 rules which are annotated to match a static node
203 The default mode for a device node is 0600 now to match the kernel
204 created devtmpfs defaults. If GROUP= is specified and no MODE= is
205 given the default will be 0660.
211 Udev now gradually starts to pass control over the primary device nodes
212 and their names to the kernel, and will in the end only manage the
213 permissions of the node, and possibly create additional symlinks.
214 As a first step NAME="" will be ignored, and NAME= setings with names
215 other than the kernel provided name will result in a logged warning.
216 Kernels that don't provide device names, or devtmpfs is not used, will
217 still work as they did before, but it is strongly recommended to use
218 only the same names for the primary device node as the recent kernel
219 provides for all devices.
223 Fix broken firmware loader search path.
229 "udevadm trigger" defaults to "change" events now instead of "add"
230 events. The "udev boot script" might need to add "--action=add" to
231 the trigger command if not already there, in case the initial coldplug
232 events are expected as "add" events.
234 The option "all_partitons" was removed from udev. This should not be
235 needed for usual hardware. Udev can not safely make assumptions
236 about non-existing partition major/minor numbers, and therefore no
237 longer provide this unreliable and unsafe option.
239 The option "ignore_remove" was removed from udev. With devtmpfs
240 udev passed control over device nodes to the kernel. This option
241 should not be needed, or can not work as advertised. Neither
242 udev nor the kernel will remove device nodes which are copied from
243 the /lib/udev/devices/ directory.
245 All "add|change" matches are replaced by "!remove" in the rules and
246 in the udev logic. All types of events will update possible symlinks
247 and permissions, only "remove" is handled special now.
249 The modem modeswitch extra was removed and the external usb_modeswitch
250 program should be used instead.
252 New and fixed keymaps.
262 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
263 depend on the current sysfs layout and the information not available in the
264 deprecated layout. All remaining support for the deprecated sysfs layout is
269 Fix for a possible endless loop in the new input_id program.
275 The option "ignore_device" does no longer exist. There is no way to
276 ignore an event, as libudev events can not be suppressed by rules.
277 It only prevented RUN keys from being executed, which results in an
278 inconsistent behavior in current setups.
280 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
281 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
284 The support for the deprecated IDE devices has been removed from the
285 default set of rules. Distros who still care about non-libata drivers
286 need to add the rules to the compat rules file.
288 The ID_CLASS property on input devices has been replaced by the more accurate
289 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
290 determined by the new "input_id" prober now. Some devices, such as touchpads,
291 can have several classes. So if you previously had custom udev rules which e. g.
292 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
293 ENV{ID_INPUT_KEYBOARD}=="?*".
299 To support DEVPATH strings larger than the maximum file name length, the
300 private udev database format has changed. If some software still reads the
301 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
302 Please do not port anything to the new format again, everything in /dev/.udev
303 is and always was private to udev, and may and will change any time without
306 Multiple devices claiming the same names in /dev are limited to symlinks
307 only now. Mixing identical symlink names and node names is not supported.
308 This reduces the amount of data in the database significantly.
310 NAME="%k" causes a warning now. It's is and always was completely superfluous.
311 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
314 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
315 if they are not the default. To support older kernels, the NAME= rules need to
316 be added to the compat rules file.
318 Symlinks to udevadm with the old command names are no longer resolved to
319 the udevadm commands.
321 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
324 The option "last_rule" does no longer exist. Its use breaks too many
325 things which expect to be run from independent later rules, and is an idication
326 that something needs to be fixed properly instead.
328 The gudev API is no longer marked as experimental,
329 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
330 is enabled by default now. Various projects already depend on introspection
331 information to bind dynamic languages to the gudev interfaces.
337 The udevadm trigger "--retry-failed" option, which is replaced since quite
338 a while by "--type=failed" is removed.
340 The failed tracking was not working at all for a few releases. The RUN
341 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
342 default is not to track any failing RUN executions.
344 New keymaps, new modem, hid2hci updated.
348 Fix possible crash in udevd when worker processes are busy, rules are
349 changed at the same time, and workers get killed to reload the rules.
355 Properties set with ENV{.FOO}="bar" are marked private by starting the
356 name with a '.'. They will not be stored in the database, and not be
357 exported with the event.
359 Firmware files are looked up in:
360 /lib/firmware/updates/$(uname -r)
361 /lib/firmware/updates
362 /lib/firmware/$(uname -r)
366 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
367 ata_id, instead of scsi_id, is the default tool now for ATA devices.
373 The configure options have changed because another library needs to be
374 installed in a different location. Instead of exec_prefix and udev_prefix,
375 libdir, rootlibdir and libexecdir are used. The Details are explained in
378 Event processes now get re-used after they handled an event. This reduces
379 the number of forks and the pressure on the CPU significantly, because
380 cloned event processes no longer cause page faults in the main daemon.
381 After the events have settled, a few worker processes stay around for
382 future events, all others get cleaned up.
384 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
385 Also inotify support is mandatory now to run udev.
387 The format of the queue exported by the udev damon has changed. There is
388 no longer a /dev/.udev/queue/ directory. The current event queue can be
389 accessed with udevadm settle and libudedv.
391 Libudev does not have the unstable API header anymore. From now on,
392 incompatible changes will be handled by bumping the library major version.
394 To build udev from the git tree gtk-doc is needed now. The tarballs will
395 build without it and contain the pre-built documentation. An online copy
397 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
399 The tools from the udev-extras repository have been merged into the main
400 udev repository. Some of the extras have larger external dependencies, and
401 they can be disabled with the configure switch --disable-extras.
407 The program vol_id and the library libvolume_id are removed from the
408 repository. Libvolume_id is merged with libblkid from the util-linux-ng
409 package. Persistent disk links for label and uuid depend on the
410 util-linux-ng version (2.15) of blkid now. Older versions of blkid
411 can not be used with udev.
413 Libudev allows to subscribe to udev events. To prevent unwanted messages
414 to be delivered, and waking up the subscribing process, a filter can be
415 installed, to drop messages inside a kernel socket filter. The filters
416 match on the <subsytem>:<devtype> properties of the device.
417 This is part of the ongoing effort to replace HAL, and switch current
418 users over to directly use libudev.
419 Libudev is still marked as experimental, and its interface might
420 eventually change if needed, but no major changes of the currently exported
421 interface are expected anymore, and a first stable release should happen
424 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
425 is not supported since while and udevd will log an error message at
426 startup. It should still be able to boot-up, but advanced rules and system
427 services which depend on the information not available in the old sysfs
428 format will fail to work correctly.
430 DVB device naming is supplied by the kernel now. In case older kernels
431 need to be supported, the old shell script should be added to a compat
438 The processed udev events get send back to the netlink socket. Libudev
439 provides access to these events. This is work-in-progress, to replace
440 the DeviceKit daemon functionality directly with libudev. There are
441 upcoming kernel changes to allow non-root users to subcribe to these
448 "udevadm settle" now optionally accepts a range of events to wait for,
449 instead of waiting for "all" events.
455 The installed watch for block device metadata changes is now removed
456 during event hadling, because some (broken) tools may be called from udev
457 rules and (wrongly) open the device with write access. After the finished
458 event handling the watch is restored.
464 Device nodes can be watched for changes with inotify with OPTIONS="watch".
465 If closed after being opened for writing, a "change" uevent will occur.
466 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
472 The udevadm test command has no longer a --force option, nodes and symlinks
473 are always updated with a test run now.
475 The udevd daemon can be started with --resolve-names=never to avoid all user
476 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
477 lookup user and groups every time events are handled.
483 We are currently merging the Ubuntu rules in the udev default rules,
484 and get one step closer to provide a common Linux /dev setup, regarding
485 device names, symlinks, and default device permissions. On udev startup,
486 we now expect the following groups to be resolvable to their ids with
488 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
489 LDAP setups need to make sure, that these groups are always resolvable at
490 bootup, with only the rootfs mounted, and without network access available.
492 Some systems may need to add some new, currently not used groups, or need
493 to add some users to new groups, but the cost of this change is minimal,
494 compared to the pain the current, rather random, differences between the
495 various distributions cause for upstream projects and third-party vendors.
497 In general, "normal" users who log into a machine should never be a member
498 of any such group, but the device-access should be managed by dynamic ACLs,
499 which get added and removed for the specific users on login/logout and
500 session activity/inactivity. These groups are only provided for custom setups,
501 and mainly system services, to allow proper privilege separation.
502 A video-streaming daemon uid would be a member of "audio" and "video", to get
503 access to the sound and video devices, but no "normal" user should ever belong
504 to the "audio" group, because he could listen to the built-in microphone with
505 any ssh-session established from the other side of the world.
507 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
508 which do not depend on the kernel device name. As usual, unique
509 devices - only a single one per product connected, or a real
510 USB serial number in the device - are always found with the same
511 name in the by-id/ directory.
512 Completely identical devices may overwrite their names in by-id/
513 and can only be found reliably in the by-path/ directory. Devices
514 specified by by-path/ must not change their connection, like the
515 USB port number they are plugged in, to keep their name.
517 To support some advanced features, Linux 2.6.22 is the oldest supported
518 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
519 supported. Older kernels should still work, and devices nodes should be
520 reliably created, but some rules and libudev will not work correctly because
521 the old kernels do not provide the expected information or interfaces.
527 Fix for a possible segfault while swapping network interface names in udev
534 The group "video" is part of the default rules now.
538 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
539 block devices in some cases. No common distro uses this option anymore,
540 and we do not get enough testing for this and recent udev versions. If
541 this option is not needed to run some old distro with a new kernel,
542 it should be disabled in the kernel config.
544 Bugfix for the $links substitution variable, which may crash if no links
545 are created. This should not happen in usual setups because we always
546 create /dev/{block,char}/ links.
548 The strings of the parsed rules, which are kept in memory, no longer
549 contain duplicate entries, or duplicate tails of strings. This, and the
550 new rules parsing/matching code reduces the total in-memory size of
551 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
554 The export of DEVTYPE=disk/partition got removed from the default
555 rules. This value is available from the kernel. The pnp shell script
556 modprobe hack is removed from the default rules. ACPI devices have _proper_
557 modalias support and take care of the same functionality.
558 Installations which support old kernels, but install current default
559 udev rules may want to add that to the compat rules file.
561 Libvolume_id now always probes for all known filesystems, and does not
562 stop at the first match. Some filesystems are marked as "exclusive probe",
563 and if any other filesytem type matches at the same time, libvolume_id
564 will, by default, not return any probing result. This is intended to prevent
565 mis-detection with conflicting left-over signatures found from earlier
566 file system formats. That way, we no longer depend on the probe-order
567 in case of multiple competing signatures. In some setups the kernel allows
568 to mount a volume with just the old filesystem signature still in place.
569 This may damage the new filesystem and cause data-loss, just by mounting
570 it. Because volume_id can not decide which one the correct signature is,
571 the wrong signatures need to be removed manually from the volume, or the
572 volume needs to be reformatted, to enable filesystem detection and possible
577 Fix segfault if compiled without optimization and dbg() does not get
578 compiled out and uses variables which are not available.
582 Bugfixes. (And maybe new bugs. :))
584 The rule matching engine got converted from a rule list to a token
585 array which reduced the in-memory rules representation of a full
586 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
587 Limits like 5 ENV and ATTR matches, and one single instance for most
588 other keys per rule are gone.
590 The NAME assignment is no longer special cased. If later rules assign
591 a NAME value again, the former value will be overwritten. As usual
592 for most other keys, the NAME value can be protected by doing a final
593 assignment with NAME:="<value>".
595 All udev code now uses libudev, which is also exported. The library
596 is still under development, marked as experimental, and its interface
597 may change as long as the DeviceKit integration is not finished.
599 Many thanks to Alan Jenkins for his continuous help, and finding and
600 optimizing some of the computing expensive parts.
606 Kernel devices and device nodes are connected now by reverse indizes in
607 /sys and /dev. A device number retrieved by a stat() or similar, the
608 kernel device directory can be found by looking up:
609 /sys/dev/{block,char}/<maj>:<min>
610 and the device node of the same device by looking up:
611 /dev/{block,char}/<maj>:<min>
615 Fix recently introduced bug, which caused a compilation without large
616 file support, where vol_id does not recognize raid signatures at the end
619 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
620 Seems some kernel versions prevent the creation of the ieee-* links,
621 so people used the scsi-* link which disappeared now.
623 More libudev work. Almost all udevadm functionality comes from libudev
626 udevadm trigger has a new option --type, which allows to trigger events
627 for "devices", for "subsystems", or "failed" devices. The old option
628 --retry-failed" still works, but is no longer mentioned in the man page.
634 The udevadm info --device-id-of-file= output has changed to use
635 the obvious format. Possible current users should use the --export
636 option which is not affected.
638 The old udev commands symlinks to udevadm are not installed, if
639 these symlinks are used, a warning is printed.
645 Optical drive's media is no longer probed for raid signatures,
646 reading the end of the device causes some devices to malfunction.
647 Also the offset of the last session found is used now to probe
650 The volume_id library got a major version number update to 1,
651 some deprecated functions are removed.
653 A shared library "libudev" gets installed now to provide access
654 to udev device information. DeviceKit, the successor of HAL, will
655 need this library to access the udev database and search sysfs for
657 The library is currently in an experimental state, also the API is
658 expected to change, as long as the DeviceKit integration is not
663 We use ./configure now. See INSTALL for details. Current
666 "/usr" - prefix for man pages, include files
668 "" - the root filesystem, prefix for libs and binaries
672 "lib" - directory name for libraries, not a path name
673 multilib 64bit systems may use "lib64" instead of "lib"
675 compile-in verbose debug messages
677 disable all logging and compile-out all log strings
679 link against SELInux libraries, to set the expected context
682 In the default rules, the group "disk" gets permissions 0660 instead
683 of 0640. One small step closer to unify distro rules. Some day, all
684 distros hopefully end up with the same set of rules.
686 No symlinks to udevadm are installed anymore, if they are still needed,
687 they should be provided by the package.
693 Default udev rules, which are not supposed to be edited by the user, should
694 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
695 the udev package and will be replaced with an update. Udev will pick up rule
697 /lib/udev/rules.d/ - default installed rules
698 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
699 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
700 It does not matter in which directory a rule file lives, all files are sorted
703 To help creating /dev/root, we have now:
704 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
707 In case the current --device-id-of-file is already used, please switch to
708 the --export format version, it saves the output parsing and the old
709 format will be changed to use ':' as a separator, like the format in the
714 Fix cdrom_id to properly recognize blank media.
720 Tape drive id-data is queried from /dev/bsg/* instead of the tape
721 nodes. This avoids rewinding tapes on open().
727 The symlinks udevcontrol and udevtrigger are no longer installed by
730 The scsi_id program does not depend on sysfs anymore. It can speak
731 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
732 data, which should solve some old problems with tape devices, where
733 we better do not open all tape device nodes to identify the device.
739 The cdrom_id program is replaced by an advanced version, which can
740 detect most common device types, and also properties of the inserted
741 media. This is part of moving some basic functionality from HAL into
742 udev (and the kernel).
748 The last WAIT_FOR_SYSFS rule is removed from the default rules.
750 The symlinks to udevadm for the debugging tools: udevmonitor and
751 udevtest are no longer created.
753 The symlinks to the udevadm man page for the old tool names are
756 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
757 should be prefixed with '@' to indicate that the path is not a
768 Udevstart is removed from the tree, it did not get installed for
769 a long time now, and is long replaced by trigger and settle.
775 All udev tools are merged into a single binary called udevadm.
776 The old names of the tools are built-in commands in udevadm now.
777 Symlinks to udevadm, with the names of the old tools, provide
778 the same functionality as the standalone tools. There is also
779 only a single udevadm.8 man page left for all tools.
781 Tools like mkinitramfs should be checked, if they need to include
782 udevadm in the list of files.
792 The etc/udev/rules.d/ directory now contains a default set of basic
793 udev rules. This initial version is the result of a rules file merge
794 of Fedora and openSUSE. For these both distros only a few specific
795 rules are left in their own file, named after the distro. Rules which
796 are optionally installed, because they are only valid for a specific
797 architecture, or rules for subsystems which are not always used are
798 in etc/udev/packages/.
804 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
805 actions by dynamically created rules.
807 SYMLINK=="<value>" matches agains the entries in the list of
808 currently defined symlinks. The links are not created in the
809 filesystem at that point in time, but the values can be matched.
811 RUN{ignore_error}+="<program>" will ignore any exit code from the
812 program and not record as a failed event.
818 Final merge of patches/features from the Ubuntu package.
824 Control characters in filesystem label strings are no longer silenty
825 removed, but hex-encoded, to be able to uniquely identify the device
826 by its symlink in /dev/disk/by-label/.
827 If libvolume_id is used by mount(8), LABEL= will work as expected,
828 if slashes or other characters are used in the label string.
830 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
831 can be specified now. The TEST key accepts an optional mode mask
832 TEST{0100}=="<is executable file>".
834 Scsi_id now supports a mode without expecting scsi-specific sysfs
835 entries to allow the extraction of cciss-device persistent properties.
841 In the future, we may see uuid's which are just simple character
842 strings (see the DDF Raid Specification). For that reason vol_id now
843 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
844 the creation of symlinks, the *_SAFE values ensure, that no control
845 or whitespace characters are used in the filename.
847 Possible users of libvolume_id, please use the volume_id_get_* functions.
848 The public struct will go away in a future release of the library.
854 Removal of useless extras/eventrecorder.sh.
864 The directory multiplexer for dev.d/ and hotplug.d are finally removed
865 from the udev package.
871 Symlinks can have priorities now, the priority is assigned to the device
872 and specified with OPTIONS="link_priority=100". Devices with higher
873 priorities overwrite the symlinks of devices with lower priorities.
874 If the device that currently owns the link, goes away, the symlink
875 will be removed, and recreated, pointing to the next device with the
876 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
877 more reliable, if multiple devices contain the same metadata and overwrite
880 The dasd_id program is removed from the udev tree, and dasdinfo, with the
881 needed rules, are part of the s390-tools now.
883 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
884 we may get the scsi sysfs mess fixed some day, and this will only catch
885 the devices we are looking for.
887 USB serial numbers for storage devices have the target:lun now appended,
888 to make it possibble to distinguish broken multi-lun devices with all
889 the same SCSI identifiers.
891 Note: The extra "run_directory" which searches and executes stuff in
892 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
893 with the next release. Make sure, that you don't use it anymore, or
894 provides your own implementation of that inefficient stuff.
895 We are tired of reports about a "slow udev", because these directories
896 contain stuff, that runs with _every_ event, instead of using rules,
897 that run programs only for the matching events.
907 DRIVER== will match only for devices that actually have a real
908 driver. DRIVERS== must be used, if parent devices should be
909 included in the match.
911 Libvolume_id's "linux_raid" detection needed another fix.
919 Add additional check to volume_id detection of via_raid, cause
920 some company decided to put a matching pattern all over the empty
921 storage area of their music players.
925 Fix path_id for SAS devices.
929 The udev daemon can be started with --debug-trace now, which will
930 execute all events serialized to get a chance to catch a possible
931 action that crashes the box.
933 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
934 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
935 are excluded from the warning. Referencing parent attributes directly
936 may break when something in the kernel driver model changes. Udev will
937 just find the attribute by walking up the parent chain.
939 Udevtrigger now sorts the list of devices depending on the device
940 dependency, so a "usb" device is triggered after the parent "pci"
945 Revert persistent-storage ata-serial '_' '-' replacement.
951 Udevtrigger can now filter the list of devices to be triggered. Matches
952 for subsystems or sysfs attributes can be specified.
954 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
955 zero-sized files to avoid pointing to /sys and confuse broken tools which
956 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
959 The rules and scripts to create udev rules for persistent network
960 devices and optical drives are in the extras/rules_generator directory
961 now. If you use something similar, please consider replacing your own
962 version with this, to share the support effort. The rule_generator
963 installs its own rules into /etc/udev/rules.d.
965 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
966 the rule_generator depends on cdrom_id to be called in an earlier rule.
972 Renaming of some key names (the old names still work):
973 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
974 (The behavior of the key DRIVER will change soon in one of the next
975 releases, to match only the event device, please switch to DRIVERS
976 instead. If DRIVER is used, it will behave like DRIVERS, but an error
978 With the new key names, we have a more consistent and simpler scheme.
979 We can match the properties of the event device only, with: KERNEL,
980 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
981 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
982 longer mentioned in the man page and should be switched in the rule
985 ATTR{file}="value" can be used now, to write to a sysfs file of the
986 event device. Instead of:
987 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
989 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
991 All the PHYSDEV* keys are deprecated and will be removed from a
993 PHYDEVPATH - is the path of a parent device and should not be
995 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
996 matched with SUBSYSTEMS==
997 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
998 Newer kernels will have DRIVER in the environment,
999 for older kernels udev puts in. Class device will
1000 no longer carry this property of a parent and
1001 DRIVERS== can be used to match such a parent value.
1002 Note that ENV{DRIVER} is only available for a few bus devices, where
1003 the driver is already bound at device event time. On coldplug, the
1004 events for a lot devices are already bound to a driver, and they will have
1005 that value set. But on hotplug, at the time the kernel creates the device,
1006 it can't know what driver may claim the device after that, therefore
1007 in most cases it will be empty.
1009 Failed events should now be re-triggered with:
1010 udevtrigger --retry-failed.
1011 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1012 files private to the udev tools. We may need to switch the current symlink
1013 target, cause some obviously broken tools try to scan all files in /dev
1014 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1015 million times. This takes ages on slow boxes.
1017 The udevinfo attribute walk (-a) now works with giving a device node
1018 name (-n) instead of a devpath (-p). The query now always works, also when
1019 no database file was created by udev.
1021 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1022 getpwnam() and getgrnam() now. One of the next releases will depend on
1023 fnmatch() and may use getopt_long().
1027 Bugfixes and small improvements.
1031 Fix path_id for recent kernels.
1037 Added support for swapping network interface names, by temporarily
1038 renaming the device and wait for the target name to become free.
1042 The built-in MODALIAS key and substitution is removed.
1046 The binary firmware helper is replaced by the usual simple
1047 shell script. Udevsend is removed from the tree.
1055 Some more keys require the correct use of '==' and '=' depending
1056 on the kind of operation beeing an assignment or a match. Rules
1057 with invalid operations are skipped and logged to syslog. Please
1058 test with udevtest if the parsing of your rules throws errors and
1059 fix possibly broken rules.
1063 Provide "udevsettle" to wait for all current udev events to finish.
1064 It also watches the current kernel netlink queue by comparing the
1065 even sequence number to make sure that there are no current pending
1066 events that have not already arrived in the daemon.
1070 Fix rule to skip persistent rules for removable IDE devices, which
1071 also skipped optical IDE drives.
1073 All *_id program are installed in /lib/udev/ by default now.
1075 No binary is stripped anymore as this should be done in the
1076 packaging process and not at build time.
1078 libvolume_id is provided as a shared library now and vol_id is
1079 linked against it. Also one of the next HAL versions will require
1080 this library, and the HAL build process will also require the
1081 header file to be installed. The copy of the same code in HAL will
1082 be removed to have only a single copy left on the system.
1086 Add persistent links for SCSI tapes. The rules file is renamed
1087 to 60-persistent-storage.rules.
1089 Create persistent path for usb devices. Can be used for all sorts
1090 of devices that can't be distinguished by other properties like
1091 multiple identical keyboards and mice connected to the same box.
1093 Provide "udevtrigger" program to request events on coldplug. The
1094 shell script is much too slow with thousends of devices.
1098 Fix persistent disk rules to exclude removable IDE drives.
1100 Warn if %e, $modalias or MODALIAS is used.
1104 Fix queue export, which wasn't correct for subsequent add/remove
1105 events for the same device.
1109 Fix cramfs detection on big endian.
1111 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1116 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1117 attributes were only checked at the parent device that matched the
1118 by BUS requested subsystem. Fix it to also look at the device we
1119 received the event for.
1121 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1126 Fix a bug where NAME="" would prevent RUN from beeing executed.
1128 RUN="/bin/program" does not longer automatically add the subsystem
1129 as the first parameter. This is from the days of /sbin/hotplug
1130 which is dead now and it's just confusing to need to add a space at
1131 the end of the program name to prevent this.
1132 If you use rules that need the subsystem as the first parameter,
1133 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1134 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1138 The udev man page has moved to udev(7) as it does not describe a command
1139 anymore. The programs udev, udevstart and udevsend are no longer installed
1140 by default and must be copied manually, if they should be installed or
1141 included in a package.
1143 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1144 the ignore rule was applied.
1146 More preparation for future sysfs changes. usb_id and scsi_id no longer
1147 depend on a magic order of devices in the /devices chain. Specific devices
1148 should be requested by their subsytem.
1150 This will always find the scsi parent device without depending on a specific
1152 dev = sysfs_device_get(devpath);
1153 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1155 The "device" link in the current sysfs layout will be automatically
1156 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1157 parent in the devpath. If a device is requested by it's symlink, like all
1158 class devices in the new sysfs layout will look like, it gets automatically
1159 resolved and substituted with the real devpath and not the symlink path.
1162 A similar logic must be applied to _all_ sysfs users, including
1163 scripts, that search along parent devices in sysfs. The explicit use of
1164 the "device" link must be avoided. With the future sysfs layout all
1165 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1166 back to the "class" or the "bus". The layout of the parent devices in
1167 /devices is not necessarily expected to be stable across kernel releases and
1168 searching for parents by their subsystem should make sysfs users tolerant
1169 for changed parent chains.
1173 Prepare udev to work with the experimental kernel patch, that moves
1174 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1176 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1177 moving the class devices to /sys/devices.
1179 Thanks again to Marco for help finding a hopefully nice compromise
1180 to make %b simpler and working again.
1184 Complete removal of libsysfs, replaced by simple helper functions
1185 which are much simpler and a bit faster. The udev daemon operatesentirely
1186 on event parameters and does not use sysfs for simple rules anymore.
1187 Please report any new bugs/problems, that may be caused by this big
1188 change. They will be fixed immediately.
1190 The enumeration format character '%e' is deprecated and will be
1191 removed sometimes from a future udev version. It never worked correctly
1192 outside of udevstart, so we can't use it with the new parallel
1193 coldplug. A simple enumeration is as useless as the devfs naming
1194 scheme, just get rid of both if you still use it.
1196 MODALIAS and $modalias is not needed and will be removed from one of
1197 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1198 the sysfs "modalias" value.
1200 Thanks a lot to Marco for all his help on finding and fixing bugs.
1204 Let scsi_id request libata drive serial numbers from page 0x80.
1206 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1207 added /dev/disk/by-name/* for device mapper device names.
1209 Removed %e from the man page. It never worked reliably outside
1210 of udevstart and udevstart is no longer recommended to use.
1214 Symlinks are now exported to the event environment. Hopefully it's no
1215 longer needed to run udevinfo from an event process, like it was
1216 mentioned on the hotplug list:
1217 UDEV [1134776873.702967] add@/block/sdb
1220 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1224 Fix a problem if udevsend is used as the hotplug handler and tries to use
1225 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1226 and this kind of problems will hopefully go away soon.
1230 All built-in logic to work around bad sysfs timing is removed with this
1231 version. The need to wait for sysfs files is almost fixed with a kernel
1232 version that doesn't work with this udev version anyway. Until we fix
1233 the timing of the "bus" link creation, the former integrated logic should
1234 be emulated by a rule placed before all other rules:
1235 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1237 The option "udev_db" does no longer exist. All udev state will be in
1238 /$udev_root/.udev/ now, there is no longer an option to set this
1240 If the init script or something else used this value, just depend on
1241 this hardcoded path. But remember _all_content_ of this directory is
1242 still private to udev and can change at any time.
1244 Default location for rule sripts and helper programs is now: /lib/udev/.
1245 Everything that is not useful on the commandline should go into this
1246 directory. Some of the helpers in the extras folder are installed there
1247 now. The rules need to be changed, to find the helpers there.
1249 Also /lib/udev/devices is recommended as a directory where packages or
1250 the user can place real device nodes, which get copied over to /dev at
1251 every boot. This should replace the various solutions with custom config
1254 Udevsend does no longer start the udev daemon. This must be done with
1255 the init script that prepares /dev on tmpfs and creates the initial nodes,
1256 before starting the daemon.
1260 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1263 The copy of klibc is removed. A systemwide installed version of klibc
1264 should be used to build a klibc udev now.
1268 NAME="" will not create any nodes, but execute RUN keys. To completely
1269 ignore an event the OPTION "ignore_device" should be used.
1271 After removal of the reorder queue, events with a TIMEOUT can be executed
1272 without any queuing now.
1276 Fixed bug in udevd, if inotify is not available. We depend on netlink
1277 uevents now, kernels without that event source will not work with that
1278 version of udev anymore.
1282 The rule parsing happens now in the daemon once at startup, all udev
1283 event processes inherit the already parsed rules from the daemon.
1284 It is shipped with SUSE10.0 and reduces heavily the system load at
1285 startup. The option to save precompiled rules and let the udev process
1286 pick the them up is removed, as it's no longer needed.
1288 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1289 device. Libsysfs is changed to "translate" the requested link into the
1290 real device path, as it would happen with the hotplug event. Otherwise
1291 device removal and the udev database will not work.
1293 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1296 A few improvements for vol_id, the filesytem probing code.
1300 Fix a stupid typo in extras/run_directory for "make install".
1302 scsi_id creates the temporary devnode now in /dev for usage with a
1303 non-writable /tmp directory.
1305 The uevent kernel socket buffer can carry app. 50.000 events now,
1306 let's see who can break this again. :)
1308 The upcoming kernel will have a new input driver core integration.
1309 Some class devices are now symlinks to the real device. libsysfs
1310 needs a fix for this to work correctly. Udevstart of older udev
1311 versions will _not_ create these devices!
1315 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1320 A bunch of mostly trivial bugfixes. From now on no node name or
1321 symlink name can contain any character than plain whitelisted ascii
1322 characters or validated utf8 byte-streams. This is needed for the
1323 /dev/disk/by-label/* links, because we import untrusted data and
1324 export it to the filesystem.
1328 More bugfixes. If udevd was started from the kernel, we don't
1329 have stdin/stdout/stderr, which broke the forked tools in some
1334 Bugfix. udevstart event ordering was broken for a long time.
1335 The new run_program() uncovered it, because /dev/null was not
1336 available while we try to run external programs.
1337 Now udevstart should create it before we run anything.
1341 Minor bugfixes and some distro rules updates. If you don't have the
1342 persistent disk rules in /dev/disk/by-*/* on your distro, just
1343 grab it from here. :)
1347 We can use socket communication now to pass events from udev to
1349 RUN+="socket:/org/freedesktop/hal/udev_event"
1350 will pass the whole udev event to the HAL daemon without the need
1351 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1355 Mostly bugfixes and see ChangeLog.
1357 The test for the existence of an environment value should be
1359 ENV{KEY}=="*" to ENV{KEY}=="?*"
1360 because "*" will not fail anymore, if the key does not exist or
1365 Bugfixes and a few tweaks described in the ChangeLog.
1369 Mostly a Bugfix release.
1371 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1372 timing with custom rules.
1376 We changed the internal rule storage format. Our large rule files took
1377 2 MB of RAM, with the change we are down to 99kB.
1379 If the device-node has been created with default name and no symlink or
1380 options are to remenber, it is not longer stored in the udevdb. HAL will
1381 need to be updated to work correctly with that change.
1383 To overrride optimization flags, OPTFLAGS may be used now.
1391 Major changes happened with this release. The goal is to take over the
1392 complete kernel-event handling and provide a more efficient way to dispatch
1393 kernel events. Replacing most of the current shell script logic and the
1394 kernel forked helper with a netlink-daemon and a rule-based event handling.
1396 o udevd listens to netlink events now. The first valid netlink event
1397 will make udevd ignore any message from udevsend that contains a
1398 SEQNUM, to avoid duplicate events. The forked events can be disabled
1400 echo "" > /proc/sys/kernel/hotplug
1401 For full support, the broken input-subsytem needs to be fixed, not to
1402 bypass the driver core.
1404 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1405 removed from udev itself and must be emulated by calling small
1406 helper binaries provided in the extras folder:
1407 make EXTRAS=extras/run_directory/
1408 will build udev_run_devd and udev_run_hotplugd, which can be called
1409 from a rule if needed:
1410 RUN+="/sbin/udev_run_hotplugd"
1411 The recommended way to handle this is to convert all the calls from
1412 the directories to explicit udev rules and get completely rid of the
1413 multiplexing. (To catch a ttyUSB event, you now no longer need to
1414 fork and exit 300 tty script instances you are not interested in, it
1415 is just one rule that matches exactly the device.)
1417 o udev handles now _all_ events not just events for class and block
1418 devices, this way it is possible to control the complete event
1419 behavior with udev rules. Especially useful for rules like:
1420 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1422 o As used in the modalias rule, udev supports now textual
1423 substitution placeholder along with the usual format chars. This
1424 needs to be documented, for now it's only visible in udev_rules_parse.c.
1426 o The rule keys support now more operations. This is documented in the
1427 man page. It is possible to add values to list-keys like the SYMLINK
1428 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1429 Also "final"-assignments are supported by using KEY:="value", which will
1430 prevent changing the key by any later rule.
1432 o kernel 2.6.12 has the "detached_state" attribute removed from
1433 sysfs, which was used to recognize sysfs population. We switched that
1434 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1435 Running this udev version on older kernels may cause a short delay for
1438 o To provide infrastructure for persistent device naming, the id programs:
1439 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1440 to export the probed data in environment key format:
1441 pim:~ # /sbin/ata_id --export /dev/hda
1442 ID_MODEL=HTS726060M9AT00
1443 ID_SERIAL=MRH401M4G6UM9B
1444 ID_REVISION=MH4OA6BA
1446 The following rules:
1447 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1448 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1451 kay@pim:~> tree /dev/disk
1454 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1455 | `-- IBM-Memory_Key -> ../../sda
1457 | |-- swap -> ../../hda1
1458 | |-- date -> ../../sda1
1459 | `-- home -> ../../hda3
1461 |-- 2E08712B0870F2E7 -> ../../hda3
1462 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1463 |-- E845-7A89 -> ../../sda1
1464 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1466 The IMPORT= operation will import these keys in the environment and make
1467 it available for later PROGRAM= and RUN= executed programs. The keys are
1468 also stored in the udevdb and can be queried from there with one of the
1471 o A few binaries are silently added to the repository, which can be used
1472 to replay kernel events from initramfs instead of using coldplug. udevd
1473 can be instructed now to queue-up events while the stored events from
1474 initramfs are filled into the udevd-queue. This code is still under
1475 development and there is no documentation now besides the code itself.
1476 The additional binaries get compiled, but are not installed by default.
1478 o There is also a temporary fix for a performance problem where too many
1479 events happen in parallel and every event needs to parse the rules.
1480 udev can now read precompiled rules stored on disk. This is likely to be
1481 replaced by a more elegant solution in a future udev version.
1485 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1486 Fix for libsysfs not to expect this file was added.
1490 All rules are applied now, but only the first matching rule with a NAME-key
1491 will be applied. All later rules with NAME-key are completely ignored. This
1492 way system supplied symlinks or permissions gets applied to user-defined
1496 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1497 to some rules, to keep the old behavior.
1499 The rules are read on "remove"-events too. That makes is possible to match
1500 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1501 instruct udev to ignore an event (OPTIONS="ignore_device").
1502 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1504 The new RUN-key supports rule-based execution of programs after device-node
1505 handling. This is meant as a general replacement for the dev.d/-directories
1506 to give fine grained control over the execution of programs.
1508 The %s{}-sysfs format char replacement values are searched at any of the
1509 devices in the device chain now, not only at the class-device.
1511 We support log priority levels now. The value udev_log in udev.conf is used
1512 to determine what is printed to syslog. This makes it possible to
1513 run a version with compiled-in debug messages in a production environment
1514 which is sometimes needed to find a bug.
1515 It is still possible to supress the inclusion of _any_ syslog usage with
1516 USE_LOG=false to create the smallest possible binaries if needed.
1517 The configured udev_log value can be overridden with the environment variable
1522 Possible use of a system-wide klibc:
1523 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1524 will link against an external klibc and our own version will be ignored.
1528 We support an unlimited count of symlinks now.
1530 If USE_STATIC=true is passed to a glibc build, we link statically and use
1531 a built-in userdb parser to resolve user and group names.
1533 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1534 we walk up the chain of physical devices to find a match.
1536 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1537 easy to skip certain attribute matches without composing rules with weird
1538 character class negations like:
1539 KERNEL="[!s][!c][!d]*"
1540 this can now be replaced with:
1542 The current simple '=' is still supported, and should work as it does today,
1543 but existing rules should be converted if possible, to be better readable.
1545 We have new ENV{}== key now, to match against a maximum of 5 environment
1548 udevstart is its own binary again, because we don't need co carry this araound
1549 with every forked event.