5 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
6 /run mountpoint is supposed to be a tmpfs mounted during early boot,
7 available and writable to for all tools at any time during bootup,
8 it replaces /var/run/, which should become a symlink some day.
10 If /run does not exist, or is not writable, udev will fall back using
13 On systemd systems with initramfs and LVM used, packagers must
14 make sure, that the systemd and initramfs versions match. The initramfs
15 needs to create the /run mountpoint for udev to store the data, and
16 mount this tmpfs to /run in the rootfs, so the that the udev database
17 is preserved for the udev version started in the rootfs.
19 The command 'udevadm info --convert-db' is gone. The udev daemon
20 itself, at startup, converts any old database version if necessary.
22 The systemd services files have been reorganized. The udev control
23 socket is bound by systemd and passed to the started udev daemon.
24 The udev-settle.service is no longer active by default. Services which
25 can not handle hotplug setups properly need to actively pull it in, to
26 act like a barrier. Alternatively the settle service can be unconditionally
27 'systemctl'enabled, and act like a barrier for basic.target.
29 The fstab_import callout is no longer built or installed. Udev
30 should not be used to mount, does not watch changes to fstab, and
31 should not mirror fstab values in the udev database.
37 New and updated keymaps.
43 The udev database has changed, After installation of a new udev
44 version, 'udevadm info --convert-db' should be called, to let the new
45 udev/libudev version read the already stored data.
47 udevadm now supports quoting of property values, and prefixing of
49 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
57 udev_device_get_is_initialized()
58 udev_enumerate_add_match_is_initialized()
59 to be able to skip devices the kernel has created , but udev has
63 udev_device_get_usec_since_initialized()
64 to retrieve the "age" of a udev device record.
66 GUdev supports a more generic GUdevEnumerator class, udev TAG
67 handling, device initialization and timestamp now.
69 The counterpart of /sys/dev/{char,block}/$major:$minor,
70 /dev/{char,block}/$major:$minor symlinks are now unconditionally
71 created, even when no rule files exist.
73 New and updated keymaps.
79 GUdev moved from /usr to /.
89 Persistent network naming rules are disabled inside of Qemu/KVM now.
91 New and updated keymaps.
93 Udev gets unconditionally enabled on systemd installations now. There
94 is no longer the need to to run 'systemctl enable udev.service'.
108 New and fixed keymaps.
110 Install systemd service files if applicable.
116 All distribution specific rules are removed from the udev source tree,
117 most of them are no longer needed. The Gentoo rules which allow to support
118 older kernel versions, which are not covered by the default rules anymore
119 has moved to rules/misc/30-kernel-compat.rules.
125 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
126 was removed from udevd.
128 Udevd now checks the kernel commandline for the following variables:
129 udev.log-priority=<syslog priority>
130 udev.children-max=<maximum number of workers>
131 udev.exec-delay=<seconds to delay the execution of RUN=>
132 to help debuging coldplug setups where the loading of a kernel
133 module crashes the system.
135 The subdirectory in the source tree rules/packages has been renamed to
136 rules/arch, anc contains only architecture specific rules now.
146 Now the udev daemon itself, does on startup:
147 - copy the content of /lib/udev/devices to /dev
148 - create the standard symlinks like /dev/std{in,out,err},
149 /dev/core, /dev/fd, ...
150 - use static node information provided by kernel modules
151 and creates these nodes to allow module on-demand loading
152 - possibly apply permissions to all ststic nodes from udev
153 rules which are annotated to match a static node
155 The default mode for a device node is 0600 now to match the kernel
156 created devtmpfs defaults. If GROUP= is specified and no MODE= is
157 given the default will be 0660.
163 Udev now gradually starts to pass control over the primary device nodes
164 and their names to the kernel, and will in the end only manage the
165 permissions of the node, and possibly create additional symlinks.
166 As a first step NAME="" will be ignored, and NAME= setings with names
167 other than the kernel provided name will result in a logged warning.
168 Kernels that don't provide device names, or devtmpfs is not used, will
169 still work as they did before, but it is strongly recommended to use
170 only the same names for the primary device node as the recent kernel
171 provides for all devices.
175 Fix broken firmware loader search path.
181 "udevadm trigger" defaults to "change" events now instead of "add"
182 events. The "udev boot script" might need to add "--action=add" to
183 the trigger command if not already there, in case the initial coldplug
184 events are expected as "add" events.
186 The option "all_partitons" was removed from udev. This should not be
187 needed for usual hardware. Udev can not safely make assumptions
188 about non-existing partition major/minor numbers, and therefore no
189 longer provide this unreliable and unsafe option.
191 The option "ignore_remove" was removed from udev. With devtmpfs
192 udev passed control over device nodes to the kernel. This option
193 should not be needed, or can not work as advertised. Neither
194 udev nor the kernel will remove device nodes which are copied from
195 the /lib/udev/devices/ directory.
197 All "add|change" matches are replaced by "!remove" in the rules and
198 in the udev logic. All types of events will update possible symlinks
199 and permissions, only "remove" is handled special now.
201 The modem modeswitch extra was removed and the external usb_modeswitch
202 program should be used instead.
204 New and fixed keymaps.
214 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
215 depend on the current sysfs layout and the information not available in the
216 deprecated layout. All remaining support for the deprecated sysfs layout is
221 Fix for a possible endless loop in the new input_id program.
227 The option "ignore_device" does no longer exist. There is no way to
228 ignore an event, as libudev events can not be suppressed by rules.
229 It only prevented RUN keys from being executed, which results in an
230 inconsistent behavior in current setups.
232 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
233 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
236 The support for the deprecated IDE devices has been removed from the
237 default set of rules. Distros who still care about non-libata drivers
238 need to add the rules to the compat rules file.
240 The ID_CLASS property on input devices has been replaced by the more accurate
241 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
242 determined by the new "input_id" prober now. Some devices, such as touchpads,
243 can have several classes. So if you previously had custom udev rules which e. g.
244 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
245 ENV{ID_INPUT_KEYBOARD}=="?*".
251 To support DEVPATH strings larger than the maximum file name length, the
252 private udev database format has changed. If some software still reads the
253 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
254 Please do not port anything to the new format again, everything in /dev/.udev
255 is and always was private to udev, and may and will change any time without
258 Multiple devices claiming the same names in /dev are limited to symlinks
259 only now. Mixing identical symlink names and node names is not supported.
260 This reduces the amount of data in the database significantly.
262 NAME="%k" causes a warning now. It's is and always was completely superfluous.
263 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
266 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
267 if they are not the default. To support older kernels, the NAME= rules need to
268 be added to the compat rules file.
270 Symlinks to udevadm with the old command names are no longer resolved to
271 the udevadm commands.
273 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
276 The option "last_rule" does no longer exist. Its use breaks too many
277 things which expect to be run from independent later rules, and is an idication
278 that something needs to be fixed properly instead.
280 The gudev API is no longer marked as experimental,
281 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
282 is enabled by default now. Various projects already depend on introspection
283 information to bind dynamic languages to the gudev interfaces.
289 The udevadm trigger "--retry-failed" option, which is replaced since quite
290 a while by "--type=failed" is removed.
292 The failed tracking was not working at all for a few releases. The RUN
293 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
294 default is not to track any failing RUN executions.
296 New keymaps, new modem, hid2hci updated.
300 Fix possible crash in udevd when worker processes are busy, rules are
301 changed at the same time, and workers get killed to reload the rules.
307 Properties set with ENV{.FOO}="bar" are marked private by starting the
308 name with a '.'. They will not be stored in the database, and not be
309 exported with the event.
311 Firmware files are looked up in:
312 /lib/firmware/updates/$(uname -r)
313 /lib/firmware/updates
314 /lib/firmware/$(uname -r)
318 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
319 ata_id, instead of scsi_id, is the default tool now for ATA devices.
325 The configure options have changed because another library needs to be
326 installed in a different location. Instead of exec_prefix and udev_prefix,
327 libdir, rootlibdir and libexecdir are used. The Details are explained in
330 Event processes now get re-used after they handled an event. This reduces
331 the number of forks and the pressure on the CPU significantly, because
332 cloned event processes no longer cause page faults in the main daemon.
333 After the events have settled, a few worker processes stay around for
334 future events, all others get cleaned up.
336 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
337 Also inotify support is mandatory now to run udev.
339 The format of the queue exported by the udev damon has changed. There is
340 no longer a /dev/.udev/queue/ directory. The current event queue can be
341 accessed with udevadm settle and libudedv.
343 Libudev does not have the unstable API header anymore. From now on,
344 incompatible changes will be handled by bumping the library major version.
346 To build udev from the git tree gtk-doc is needed now. The tarballs will
347 build without it and contain the pre-built documentation. An online copy
349 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
351 The tools from the udev-extras repository have been merged into the main
352 udev repository. Some of the extras have larger external dependencies, and
353 they can be disabled with the configure switch --disable-extras.
359 The program vol_id and the library libvolume_id are removed from the
360 repository. Libvolume_id is merged with libblkid from the util-linux-ng
361 package. Persistent disk links for label and uuid depend on the
362 util-linux-ng version (2.15) of blkid now. Older versions of blkid
363 can not be used with udev.
365 Libudev allows to subscribe to udev events. To prevent unwanted messages
366 to be delivered, and waking up the subscribing process, a filter can be
367 installed, to drop messages inside a kernel socket filter. The filters
368 match on the <subsytem>:<devtype> properties of the device.
369 This is part of the ongoing effort to replace HAL, and switch current
370 users over to directly use libudev.
371 Libudev is still marked as experimental, and its interface might
372 eventually change if needed, but no major changes of the currently exported
373 interface are expected anymore, and a first stable release should happen
376 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
377 is not supported since while and udevd will log an error message at
378 startup. It should still be able to boot-up, but advanced rules and system
379 services which depend on the information not available in the old sysfs
380 format will fail to work correctly.
382 DVB device naming is supplied by the kernel now. In case older kernels
383 need to be supported, the old shell script should be added to a compat
390 The processed udev events get send back to the netlink socket. Libudev
391 provides access to these events. This is work-in-progress, to replace
392 the DeviceKit daemon functionality directly with libudev. There are
393 upcoming kernel changes to allow non-root users to subcribe to these
400 "udevadm settle" now optionally accepts a range of events to wait for,
401 instead of waiting for "all" events.
407 The installed watch for block device metadata changes is now removed
408 during event hadling, because some (broken) tools may be called from udev
409 rules and (wrongly) open the device with write access. After the finished
410 event handling the watch is restored.
416 Device nodes can be watched for changes with inotify with OPTIONS="watch".
417 If closed after being opened for writing, a "change" uevent will occur.
418 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
424 The udevadm test command has no longer a --force option, nodes and symlinks
425 are always updated with a test run now.
427 The udevd daemon can be started with --resolve-names=never to avoid all user
428 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
429 lookup user and groups every time events are handled.
435 We are currently merging the Ubuntu rules in the udev default rules,
436 and get one step closer to provide a common Linux /dev setup, regarding
437 device names, symlinks, and default device permissions. On udev startup,
438 we now expect the following groups to be resolvable to their ids with
440 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
441 LDAP setups need to make sure, that these groups are always resolvable at
442 bootup, with only the rootfs mounted, and without network access available.
444 Some systems may need to add some new, currently not used groups, or need
445 to add some users to new groups, but the cost of this change is minimal,
446 compared to the pain the current, rather random, differences between the
447 various distributions cause for upstream projects and third-party vendors.
449 In general, "normal" users who log into a machine should never be a member
450 of any such group, but the device-access should be managed by dynamic ACLs,
451 which get added and removed for the specific users on login/logout and
452 session activity/inactivity. These groups are only provided for custom setups,
453 and mainly system services, to allow proper privilege separation.
454 A video-streaming daemon uid would be a member of "audio" and "video", to get
455 access to the sound and video devices, but no "normal" user should ever belong
456 to the "audio" group, because he could listen to the built-in microphone with
457 any ssh-session established from the other side of the world.
459 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
460 which do not depend on the kernel device name. As usual, unique
461 devices - only a single one per product connected, or a real
462 USB serial number in the device - are always found with the same
463 name in the by-id/ directory.
464 Completely identical devices may overwrite their names in by-id/
465 and can only be found reliably in the by-path/ directory. Devices
466 specified by by-path/ must not change their connection, like the
467 USB port number they are plugged in, to keep their name.
469 To support some advanced features, Linux 2.6.22 is the oldest supported
470 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
471 supported. Older kernels should still work, and devices nodes should be
472 reliably created, but some rules and libudev will not work correctly because
473 the old kernels do not provide the expected information or interfaces.
479 Fix for a possible segfault while swapping network interface names in udev
486 The group "video" is part of the default rules now.
490 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
491 block devices in some cases. No common distro uses this option anymore,
492 and we do not get enough testing for this and recent udev versions. If
493 this option is not needed to run some old distro with a new kernel,
494 it should be disabled in the kernel config.
496 Bugfix for the $links substitution variable, which may crash if no links
497 are created. This should not happen in usual setups because we always
498 create /dev/{block,char}/ links.
500 The strings of the parsed rules, which are kept in memory, no longer
501 contain duplicate entries, or duplicate tails of strings. This, and the
502 new rules parsing/matching code reduces the total in-memory size of
503 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
506 The export of DEVTYPE=disk/partition got removed from the default
507 rules. This value is available from the kernel. The pnp shell script
508 modprobe hack is removed from the default rules. ACPI devices have _proper_
509 modalias support and take care of the same functionality.
510 Installations which support old kernels, but install current default
511 udev rules may want to add that to the compat rules file.
513 Libvolume_id now always probes for all known filesystems, and does not
514 stop at the first match. Some filesystems are marked as "exclusive probe",
515 and if any other filesytem type matches at the same time, libvolume_id
516 will, by default, not return any probing result. This is intended to prevent
517 mis-detection with conflicting left-over signatures found from earlier
518 file system formats. That way, we no longer depend on the probe-order
519 in case of multiple competing signatures. In some setups the kernel allows
520 to mount a volume with just the old filesystem signature still in place.
521 This may damage the new filesystem and cause data-loss, just by mounting
522 it. Because volume_id can not decide which one the correct signature is,
523 the wrong signatures need to be removed manually from the volume, or the
524 volume needs to be reformatted, to enable filesystem detection and possible
529 Fix segfault if compiled without optimization and dbg() does not get
530 compiled out and uses variables which are not available.
534 Bugfixes. (And maybe new bugs. :))
536 The rule matching engine got converted from a rule list to a token
537 array which reduced the in-memory rules representation of a full
538 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
539 Limits like 5 ENV and ATTR matches, and one single instance for most
540 other keys per rule are gone.
542 The NAME assignment is no longer special cased. If later rules assign
543 a NAME value again, the former value will be overwritten. As usual
544 for most other keys, the NAME value can be protected by doing a final
545 assignment with NAME:="<value>".
547 All udev code now uses libudev, which is also exported. The library
548 is still under development, marked as experimental, and its interface
549 may change as long as the DeviceKit integration is not finished.
551 Many thanks to Alan Jenkins for his continuous help, and finding and
552 optimizing some of the computing expensive parts.
558 Kernel devices and device nodes are connected now by reverse indizes in
559 /sys and /dev. A device number retrieved by a stat() or similar, the
560 kernel device directory can be found by looking up:
561 /sys/dev/{block,char}/<maj>:<min>
562 and the device node of the same device by looking up:
563 /dev/{block,char}/<maj>:<min>
567 Fix recently introduced bug, which caused a compilation without large
568 file support, where vol_id does not recognize raid signatures at the end
571 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
572 Seems some kernel versions prevent the creation of the ieee-* links,
573 so people used the scsi-* link which disappeared now.
575 More libudev work. Almost all udevadm functionality comes from libudev
578 udevadm trigger has a new option --type, which allows to trigger events
579 for "devices", for "subsystems", or "failed" devices. The old option
580 --retry-failed" still works, but is no longer mentioned in the man page.
586 The udevadm info --device-id-of-file= output has changed to use
587 the obvious format. Possible current users should use the --export
588 option which is not affected.
590 The old udev commands symlinks to udevadm are not installed, if
591 these symlinks are used, a warning is printed.
597 Optical drive's media is no longer probed for raid signatures,
598 reading the end of the device causes some devices to malfunction.
599 Also the offset of the last session found is used now to probe
602 The volume_id library got a major version number update to 1,
603 some deprecated functions are removed.
605 A shared library "libudev" gets installed now to provide access
606 to udev device information. DeviceKit, the successor of HAL, will
607 need this library to access the udev database and search sysfs for
609 The library is currently in an experimental state, also the API is
610 expected to change, as long as the DeviceKit integration is not
615 We use ./configure now. See INSTALL for details. Current
618 "/usr" - prefix for man pages, include files
620 "" - the root filesystem, prefix for libs and binaries
624 "lib" - directory name for libraries, not a path name
625 multilib 64bit systems may use "lib64" instead of "lib"
627 compile-in verbose debug messages
629 disable all logging and compile-out all log strings
631 link against SELInux libraries, to set the expected context
634 In the default rules, the group "disk" gets permissions 0660 instead
635 of 0640. One small step closer to unify distro rules. Some day, all
636 distros hopefully end up with the same set of rules.
638 No symlinks to udevadm are installed anymore, if they are still needed,
639 they should be provided by the package.
645 Default udev rules, which are not supposed to be edited by the user, should
646 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
647 the udev package and will be replaced with an update. Udev will pick up rule
649 /lib/udev/rules.d/ - default installed rules
650 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
651 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
652 It does not matter in which directory a rule file lives, all files are sorted
655 To help creating /dev/root, we have now:
656 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
659 In case the current --device-id-of-file is already used, please switch to
660 the --export format version, it saves the output parsing and the old
661 format will be changed to use ':' as a separator, like the format in the
666 Fix cdrom_id to properly recognize blank media.
672 Tape drive id-data is queried from /dev/bsg/* instead of the tape
673 nodes. This avoids rewinding tapes on open().
679 The symlinks udevcontrol and udevtrigger are no longer installed by
682 The scsi_id program does not depend on sysfs anymore. It can speak
683 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
684 data, which should solve some old problems with tape devices, where
685 we better do not open all tape device nodes to identify the device.
691 The cdrom_id program is replaced by an advanced version, which can
692 detect most common device types, and also properties of the inserted
693 media. This is part of moving some basic functionality from HAL into
694 udev (and the kernel).
700 The last WAIT_FOR_SYSFS rule is removed from the default rules.
702 The symlinks to udevadm for the debugging tools: udevmonitor and
703 udevtest are no longer created.
705 The symlinks to the udevadm man page for the old tool names are
708 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
709 should be prefixed with '@' to indicate that the path is not a
720 Udevstart is removed from the tree, it did not get installed for
721 a long time now, and is long replaced by trigger and settle.
727 All udev tools are merged into a single binary called udevadm.
728 The old names of the tools are built-in commands in udevadm now.
729 Symlinks to udevadm, with the names of the old tools, provide
730 the same functionality as the standalone tools. There is also
731 only a single udevadm.8 man page left for all tools.
733 Tools like mkinitramfs should be checked, if they need to include
734 udevadm in the list of files.
744 The etc/udev/rules.d/ directory now contains a default set of basic
745 udev rules. This initial version is the result of a rules file merge
746 of Fedora and openSUSE. For these both distros only a few specific
747 rules are left in their own file, named after the distro. Rules which
748 are optionally installed, because they are only valid for a specific
749 architecture, or rules for subsystems which are not always used are
750 in etc/udev/packages/.
756 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
757 actions by dynamically created rules.
759 SYMLINK=="<value>" matches agains the entries in the list of
760 currently defined symlinks. The links are not created in the
761 filesystem at that point in time, but the values can be matched.
763 RUN{ignore_error}+="<program>" will ignore any exit code from the
764 program and not record as a failed event.
770 Final merge of patches/features from the Ubuntu package.
776 Control characters in filesystem label strings are no longer silenty
777 removed, but hex-encoded, to be able to uniquely identify the device
778 by its symlink in /dev/disk/by-label/.
779 If libvolume_id is used by mount(8), LABEL= will work as expected,
780 if slashes or other characters are used in the label string.
782 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
783 can be specified now. The TEST key accepts an optional mode mask
784 TEST{0100}=="<is executable file>".
786 Scsi_id now supports a mode without expecting scsi-specific sysfs
787 entries to allow the extraction of cciss-device persistent properties.
793 In the future, we may see uuid's which are just simple character
794 strings (see the DDF Raid Specification). For that reason vol_id now
795 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
796 the creation of symlinks, the *_SAFE values ensure, that no control
797 or whitespace characters are used in the filename.
799 Possible users of libvolume_id, please use the volume_id_get_* functions.
800 The public struct will go away in a future release of the library.
806 Removal of useless extras/eventrecorder.sh.
816 The directory multiplexer for dev.d/ and hotplug.d are finally removed
817 from the udev package.
823 Symlinks can have priorities now, the priority is assigned to the device
824 and specified with OPTIONS="link_priority=100". Devices with higher
825 priorities overwrite the symlinks of devices with lower priorities.
826 If the device that currently owns the link, goes away, the symlink
827 will be removed, and recreated, pointing to the next device with the
828 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
829 more reliable, if multiple devices contain the same metadata and overwrite
832 The dasd_id program is removed from the udev tree, and dasdinfo, with the
833 needed rules, are part of the s390-tools now.
835 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
836 we may get the scsi sysfs mess fixed some day, and this will only catch
837 the devices we are looking for.
839 USB serial numbers for storage devices have the target:lun now appended,
840 to make it possibble to distinguish broken multi-lun devices with all
841 the same SCSI identifiers.
843 Note: The extra "run_directory" which searches and executes stuff in
844 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
845 with the next release. Make sure, that you don't use it anymore, or
846 provides your own implementation of that inefficient stuff.
847 We are tired of reports about a "slow udev", because these directories
848 contain stuff, that runs with _every_ event, instead of using rules,
849 that run programs only for the matching events.
859 DRIVER== will match only for devices that actually have a real
860 driver. DRIVERS== must be used, if parent devices should be
861 included in the match.
863 Libvolume_id's "linux_raid" detection needed another fix.
871 Add additional check to volume_id detection of via_raid, cause
872 some company decided to put a matching pattern all over the empty
873 storage area of their music players.
877 Fix path_id for SAS devices.
881 The udev daemon can be started with --debug-trace now, which will
882 execute all events serialized to get a chance to catch a possible
883 action that crashes the box.
885 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
886 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
887 are excluded from the warning. Referencing parent attributes directly
888 may break when something in the kernel driver model changes. Udev will
889 just find the attribute by walking up the parent chain.
891 Udevtrigger now sorts the list of devices depending on the device
892 dependency, so a "usb" device is triggered after the parent "pci"
897 Revert persistent-storage ata-serial '_' '-' replacement.
903 Udevtrigger can now filter the list of devices to be triggered. Matches
904 for subsystems or sysfs attributes can be specified.
906 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
907 zero-sized files to avoid pointing to /sys and confuse broken tools which
908 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
911 The rules and scripts to create udev rules for persistent network
912 devices and optical drives are in the extras/rules_generator directory
913 now. If you use something similar, please consider replacing your own
914 version with this, to share the support effort. The rule_generator
915 installs its own rules into /etc/udev/rules.d.
917 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
918 the rule_generator depends on cdrom_id to be called in an earlier rule.
924 Renaming of some key names (the old names still work):
925 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
926 (The behavior of the key DRIVER will change soon in one of the next
927 releases, to match only the event device, please switch to DRIVERS
928 instead. If DRIVER is used, it will behave like DRIVERS, but an error
930 With the new key names, we have a more consistent and simpler scheme.
931 We can match the properties of the event device only, with: KERNEL,
932 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
933 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
934 longer mentioned in the man page and should be switched in the rule
937 ATTR{file}="value" can be used now, to write to a sysfs file of the
938 event device. Instead of:
939 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
941 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
943 All the PHYSDEV* keys are deprecated and will be removed from a
945 PHYDEVPATH - is the path of a parent device and should not be
947 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
948 matched with SUBSYSTEMS==
949 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
950 Newer kernels will have DRIVER in the environment,
951 for older kernels udev puts in. Class device will
952 no longer carry this property of a parent and
953 DRIVERS== can be used to match such a parent value.
954 Note that ENV{DRIVER} is only available for a few bus devices, where
955 the driver is already bound at device event time. On coldplug, the
956 events for a lot devices are already bound to a driver, and they will have
957 that value set. But on hotplug, at the time the kernel creates the device,
958 it can't know what driver may claim the device after that, therefore
959 in most cases it will be empty.
961 Failed events should now be re-triggered with:
962 udevtrigger --retry-failed.
963 Please switch to this command, so we keep the details of the /dev/.udev/failed/
964 files private to the udev tools. We may need to switch the current symlink
965 target, cause some obviously broken tools try to scan all files in /dev
966 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
967 million times. This takes ages on slow boxes.
969 The udevinfo attribute walk (-a) now works with giving a device node
970 name (-n) instead of a devpath (-p). The query now always works, also when
971 no database file was created by udev.
973 The built-in /etc/passwd /etc/group parser is removed, we always depend on
974 getpwnam() and getgrnam() now. One of the next releases will depend on
975 fnmatch() and may use getopt_long().
979 Bugfixes and small improvements.
983 Fix path_id for recent kernels.
989 Added support for swapping network interface names, by temporarily
990 renaming the device and wait for the target name to become free.
994 The built-in MODALIAS key and substitution is removed.
998 The binary firmware helper is replaced by the usual simple
999 shell script. Udevsend is removed from the tree.
1007 Some more keys require the correct use of '==' and '=' depending
1008 on the kind of operation beeing an assignment or a match. Rules
1009 with invalid operations are skipped and logged to syslog. Please
1010 test with udevtest if the parsing of your rules throws errors and
1011 fix possibly broken rules.
1015 Provide "udevsettle" to wait for all current udev events to finish.
1016 It also watches the current kernel netlink queue by comparing the
1017 even sequence number to make sure that there are no current pending
1018 events that have not already arrived in the daemon.
1022 Fix rule to skip persistent rules for removable IDE devices, which
1023 also skipped optical IDE drives.
1025 All *_id program are installed in /lib/udev/ by default now.
1027 No binary is stripped anymore as this should be done in the
1028 packaging process and not at build time.
1030 libvolume_id is provided as a shared library now and vol_id is
1031 linked against it. Also one of the next HAL versions will require
1032 this library, and the HAL build process will also require the
1033 header file to be installed. The copy of the same code in HAL will
1034 be removed to have only a single copy left on the system.
1038 Add persistent links for SCSI tapes. The rules file is renamed
1039 to 60-persistent-storage.rules.
1041 Create persistent path for usb devices. Can be used for all sorts
1042 of devices that can't be distinguished by other properties like
1043 multiple identical keyboards and mice connected to the same box.
1045 Provide "udevtrigger" program to request events on coldplug. The
1046 shell script is much too slow with thousends of devices.
1050 Fix persistent disk rules to exclude removable IDE drives.
1052 Warn if %e, $modalias or MODALIAS is used.
1056 Fix queue export, which wasn't correct for subsequent add/remove
1057 events for the same device.
1061 Fix cramfs detection on big endian.
1063 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1068 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1069 attributes were only checked at the parent device that matched the
1070 by BUS requested subsystem. Fix it to also look at the device we
1071 received the event for.
1073 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1078 Fix a bug where NAME="" would prevent RUN from beeing executed.
1080 RUN="/bin/program" does not longer automatically add the subsystem
1081 as the first parameter. This is from the days of /sbin/hotplug
1082 which is dead now and it's just confusing to need to add a space at
1083 the end of the program name to prevent this.
1084 If you use rules that need the subsystem as the first parameter,
1085 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1086 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1090 The udev man page has moved to udev(7) as it does not describe a command
1091 anymore. The programs udev, udevstart and udevsend are no longer installed
1092 by default and must be copied manually, if they should be installed or
1093 included in a package.
1095 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1096 the ignore rule was applied.
1098 More preparation for future sysfs changes. usb_id and scsi_id no longer
1099 depend on a magic order of devices in the /devices chain. Specific devices
1100 should be requested by their subsytem.
1102 This will always find the scsi parent device without depending on a specific
1104 dev = sysfs_device_get(devpath);
1105 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1107 The "device" link in the current sysfs layout will be automatically
1108 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1109 parent in the devpath. If a device is requested by it's symlink, like all
1110 class devices in the new sysfs layout will look like, it gets automatically
1111 resolved and substituted with the real devpath and not the symlink path.
1114 A similar logic must be applied to _all_ sysfs users, including
1115 scripts, that search along parent devices in sysfs. The explicit use of
1116 the "device" link must be avoided. With the future sysfs layout all
1117 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1118 back to the "class" or the "bus". The layout of the parent devices in
1119 /devices is not necessarily expected to be stable across kernel releases and
1120 searching for parents by their subsystem should make sysfs users tolerant
1121 for changed parent chains.
1125 Prepare udev to work with the experimental kernel patch, that moves
1126 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1128 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1129 moving the class devices to /sys/devices.
1131 Thanks again to Marco for help finding a hopefully nice compromise
1132 to make %b simpler and working again.
1136 Complete removal of libsysfs, replaced by simple helper functions
1137 which are much simpler and a bit faster. The udev daemon operatesentirely
1138 on event parameters and does not use sysfs for simple rules anymore.
1139 Please report any new bugs/problems, that may be caused by this big
1140 change. They will be fixed immediately.
1142 The enumeration format character '%e' is deprecated and will be
1143 removed sometimes from a future udev version. It never worked correctly
1144 outside of udevstart, so we can't use it with the new parallel
1145 coldplug. A simple enumeration is as useless as the devfs naming
1146 scheme, just get rid of both if you still use it.
1148 MODALIAS and $modalias is not needed and will be removed from one of
1149 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1150 the sysfs "modalias" value.
1152 Thanks a lot to Marco for all his help on finding and fixing bugs.
1156 Let scsi_id request libata drive serial numbers from page 0x80.
1158 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1159 added /dev/disk/by-name/* for device mapper device names.
1161 Removed %e from the man page. It never worked reliably outside
1162 of udevstart and udevstart is no longer recommended to use.
1166 Symlinks are now exported to the event environment. Hopefully it's no
1167 longer needed to run udevinfo from an event process, like it was
1168 mentioned on the hotplug list:
1169 UDEV [1134776873.702967] add@/block/sdb
1172 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1176 Fix a problem if udevsend is used as the hotplug handler and tries to use
1177 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1178 and this kind of problems will hopefully go away soon.
1182 All built-in logic to work around bad sysfs timing is removed with this
1183 version. The need to wait for sysfs files is almost fixed with a kernel
1184 version that doesn't work with this udev version anyway. Until we fix
1185 the timing of the "bus" link creation, the former integrated logic should
1186 be emulated by a rule placed before all other rules:
1187 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1189 The option "udev_db" does no longer exist. All udev state will be in
1190 /$udev_root/.udev/ now, there is no longer an option to set this
1192 If the init script or something else used this value, just depend on
1193 this hardcoded path. But remember _all_content_ of this directory is
1194 still private to udev and can change at any time.
1196 Default location for rule sripts and helper programs is now: /lib/udev/.
1197 Everything that is not useful on the commandline should go into this
1198 directory. Some of the helpers in the extras folder are installed there
1199 now. The rules need to be changed, to find the helpers there.
1201 Also /lib/udev/devices is recommended as a directory where packages or
1202 the user can place real device nodes, which get copied over to /dev at
1203 every boot. This should replace the various solutions with custom config
1206 Udevsend does no longer start the udev daemon. This must be done with
1207 the init script that prepares /dev on tmpfs and creates the initial nodes,
1208 before starting the daemon.
1212 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1215 The copy of klibc is removed. A systemwide installed version of klibc
1216 should be used to build a klibc udev now.
1220 NAME="" will not create any nodes, but execute RUN keys. To completely
1221 ignore an event the OPTION "ignore_device" should be used.
1223 After removal of the reorder queue, events with a TIMEOUT can be executed
1224 without any queuing now.
1228 Fixed bug in udevd, if inotify is not available. We depend on netlink
1229 uevents now, kernels without that event source will not work with that
1230 version of udev anymore.
1234 The rule parsing happens now in the daemon once at startup, all udev
1235 event processes inherit the already parsed rules from the daemon.
1236 It is shipped with SUSE10.0 and reduces heavily the system load at
1237 startup. The option to save precompiled rules and let the udev process
1238 pick the them up is removed, as it's no longer needed.
1240 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1241 device. Libsysfs is changed to "translate" the requested link into the
1242 real device path, as it would happen with the hotplug event. Otherwise
1243 device removal and the udev database will not work.
1245 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1248 A few improvements for vol_id, the filesytem probing code.
1252 Fix a stupid typo in extras/run_directory for "make install".
1254 scsi_id creates the temporary devnode now in /dev for usage with a
1255 non-writable /tmp directory.
1257 The uevent kernel socket buffer can carry app. 50.000 events now,
1258 let's see who can break this again. :)
1260 The upcoming kernel will have a new input driver core integration.
1261 Some class devices are now symlinks to the real device. libsysfs
1262 needs a fix for this to work correctly. Udevstart of older udev
1263 versions will _not_ create these devices!
1267 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1272 A bunch of mostly trivial bugfixes. From now on no node name or
1273 symlink name can contain any character than plain whitelisted ascii
1274 characters or validated utf8 byte-streams. This is needed for the
1275 /dev/disk/by-label/* links, because we import untrusted data and
1276 export it to the filesystem.
1280 More bugfixes. If udevd was started from the kernel, we don't
1281 have stdin/stdout/stderr, which broke the forked tools in some
1286 Bugfix. udevstart event ordering was broken for a long time.
1287 The new run_program() uncovered it, because /dev/null was not
1288 available while we try to run external programs.
1289 Now udevstart should create it before we run anything.
1293 Minor bugfixes and some distro rules updates. If you don't have the
1294 persistent disk rules in /dev/disk/by-*/* on your distro, just
1295 grab it from here. :)
1299 We can use socket communication now to pass events from udev to
1301 RUN+="socket:/org/freedesktop/hal/udev_event"
1302 will pass the whole udev event to the HAL daemon without the need
1303 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1307 Mostly bugfixes and see ChangeLog.
1309 The test for the existence of an environment value should be
1311 ENV{KEY}=="*" to ENV{KEY}=="?*"
1312 because "*" will not fail anymore, if the key does not exist or
1317 Bugfixes and a few tweaks described in the ChangeLog.
1321 Mostly a Bugfix release.
1323 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1324 timing with custom rules.
1328 We changed the internal rule storage format. Our large rule files took
1329 2 MB of RAM, with the change we are down to 99kB.
1331 If the device-node has been created with default name and no symlink or
1332 options are to remenber, it is not longer stored in the udevdb. HAL will
1333 need to be updated to work correctly with that change.
1335 To overrride optimization flags, OPTFLAGS may be used now.
1343 Major changes happened with this release. The goal is to take over the
1344 complete kernel-event handling and provide a more efficient way to dispatch
1345 kernel events. Replacing most of the current shell script logic and the
1346 kernel forked helper with a netlink-daemon and a rule-based event handling.
1348 o udevd listens to netlink events now. The first valid netlink event
1349 will make udevd ignore any message from udevsend that contains a
1350 SEQNUM, to avoid duplicate events. The forked events can be disabled
1352 echo "" > /proc/sys/kernel/hotplug
1353 For full support, the broken input-subsytem needs to be fixed, not to
1354 bypass the driver core.
1356 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1357 removed from udev itself and must be emulated by calling small
1358 helper binaries provided in the extras folder:
1359 make EXTRAS=extras/run_directory/
1360 will build udev_run_devd and udev_run_hotplugd, which can be called
1361 from a rule if needed:
1362 RUN+="/sbin/udev_run_hotplugd"
1363 The recommended way to handle this is to convert all the calls from
1364 the directories to explicit udev rules and get completely rid of the
1365 multiplexing. (To catch a ttyUSB event, you now no longer need to
1366 fork and exit 300 tty script instances you are not interested in, it
1367 is just one rule that matches exactly the device.)
1369 o udev handles now _all_ events not just events for class and block
1370 devices, this way it is possible to control the complete event
1371 behavior with udev rules. Especially useful for rules like:
1372 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1374 o As used in the modalias rule, udev supports now textual
1375 substitution placeholder along with the usual format chars. This
1376 needs to be documented, for now it's only visible in udev_rules_parse.c.
1378 o The rule keys support now more operations. This is documented in the
1379 man page. It is possible to add values to list-keys like the SYMLINK
1380 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1381 Also "final"-assignments are supported by using KEY:="value", which will
1382 prevent changing the key by any later rule.
1384 o kernel 2.6.12 has the "detached_state" attribute removed from
1385 sysfs, which was used to recognize sysfs population. We switched that
1386 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1387 Running this udev version on older kernels may cause a short delay for
1390 o To provide infrastructure for persistent device naming, the id programs:
1391 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1392 to export the probed data in environment key format:
1393 pim:~ # /sbin/ata_id --export /dev/hda
1394 ID_MODEL=HTS726060M9AT00
1395 ID_SERIAL=MRH401M4G6UM9B
1396 ID_REVISION=MH4OA6BA
1398 The following rules:
1399 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1400 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1403 kay@pim:~> tree /dev/disk
1406 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1407 | `-- IBM-Memory_Key -> ../../sda
1409 | |-- swap -> ../../hda1
1410 | |-- date -> ../../sda1
1411 | `-- home -> ../../hda3
1413 |-- 2E08712B0870F2E7 -> ../../hda3
1414 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1415 |-- E845-7A89 -> ../../sda1
1416 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1418 The IMPORT= operation will import these keys in the environment and make
1419 it available for later PROGRAM= and RUN= executed programs. The keys are
1420 also stored in the udevdb and can be queried from there with one of the
1423 o A few binaries are silently added to the repository, which can be used
1424 to replay kernel events from initramfs instead of using coldplug. udevd
1425 can be instructed now to queue-up events while the stored events from
1426 initramfs are filled into the udevd-queue. This code is still under
1427 development and there is no documentation now besides the code itself.
1428 The additional binaries get compiled, but are not installed by default.
1430 o There is also a temporary fix for a performance problem where too many
1431 events happen in parallel and every event needs to parse the rules.
1432 udev can now read precompiled rules stored on disk. This is likely to be
1433 replaced by a more elegant solution in a future udev version.
1437 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1438 Fix for libsysfs not to expect this file was added.
1442 All rules are applied now, but only the first matching rule with a NAME-key
1443 will be applied. All later rules with NAME-key are completely ignored. This
1444 way system supplied symlinks or permissions gets applied to user-defined
1448 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1449 to some rules, to keep the old behavior.
1451 The rules are read on "remove"-events too. That makes is possible to match
1452 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1453 instruct udev to ignore an event (OPTIONS="ignore_device").
1454 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1456 The new RUN-key supports rule-based execution of programs after device-node
1457 handling. This is meant as a general replacement for the dev.d/-directories
1458 to give fine grained control over the execution of programs.
1460 The %s{}-sysfs format char replacement values are searched at any of the
1461 devices in the device chain now, not only at the class-device.
1463 We support log priority levels now. The value udev_log in udev.conf is used
1464 to determine what is printed to syslog. This makes it possible to
1465 run a version with compiled-in debug messages in a production environment
1466 which is sometimes needed to find a bug.
1467 It is still possible to supress the inclusion of _any_ syslog usage with
1468 USE_LOG=false to create the smallest possible binaries if needed.
1469 The configured udev_log value can be overridden with the environment variable
1474 Possible use of a system-wide klibc:
1475 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1476 will link against an external klibc and our own version will be ignored.
1480 We support an unlimited count of symlinks now.
1482 If USE_STATIC=true is passed to a glibc build, we link statically and use
1483 a built-in userdb parser to resolve user and group names.
1485 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1486 we walk up the chain of physical devices to find a match.
1488 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1489 easy to skip certain attribute matches without composing rules with weird
1490 character class negations like:
1491 KERNEL="[!s][!c][!d]*"
1492 this can now be replaced with:
1494 The current simple '=' is still supported, and should work as it does today,
1495 but existing rules should be converted if possible, to be better readable.
1497 We have new ENV{}== key now, to match against a maximum of 5 environment
1500 udevstart is its own binary again, because we don't need co carry this araound
1501 with every forked event.