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 fstab_import callout is no longer built or installed. Udev
23 should not be used to mount, does not watch changes to fstab, and
24 should not mirror fstab values in the udev database.
30 New and updated keymaps.
36 The udev database has changed, After installation of a new udev
37 version, 'udevadm info --convert-db' should be called, to let the new
38 udev/libudev version read the already stored data.
40 udevadm now supports quoting of property values, and prefixing of
42 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
50 udev_device_get_is_initialized()
51 udev_enumerate_add_match_is_initialized()
52 to be able to skip devices the kernel has created , but udev has
56 udev_device_get_usec_since_initialized()
57 to retrieve the "age" of a udev device record.
59 GUdev supports a more generic GUdevEnumerator class, udev TAG
60 handling, device initialization and timestamp now.
62 The counterpart of /sys/dev/{char,block}/$major:$minor,
63 /dev/{char,block}/$major:$minor symlinks are now unconditionally
64 created, even when no rule files exist.
66 New and updated keymaps.
72 GUdev moved from /usr to /.
82 Persistent network naming rules are disabled inside of Qemu/KVM now.
84 New and updated keymaps.
86 Udev gets unconditionally enabled on systemd installations now. There
87 is no longer the need to to run 'systemctl enable udev.service'.
101 New and fixed keymaps.
103 Install systemd service files if applicable.
109 All distribution specific rules are removed from the udev source tree,
110 most of them are no longer needed. The Gentoo rules which allow to support
111 older kernel versions, which are not covered by the default rules anymore
112 has moved to rules/misc/30-kernel-compat.rules.
118 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
119 was removed from udevd.
121 Udevd now checks the kernel commandline for the following variables:
122 udev.log-priority=<syslog priority>
123 udev.children-max=<maximum number of workers>
124 udev.exec-delay=<seconds to delay the execution of RUN=>
125 to help debuging coldplug setups where the loading of a kernel
126 module crashes the system.
128 The subdirectory in the source tree rules/packages has been renamed to
129 rules/arch, anc contains only architecture specific rules now.
139 Now the udev daemon itself, does on startup:
140 - copy the content of /lib/udev/devices to /dev
141 - create the standard symlinks like /dev/std{in,out,err},
142 /dev/core, /dev/fd, ...
143 - use static node information provided by kernel modules
144 and creates these nodes to allow module on-demand loading
145 - possibly apply permissions to all ststic nodes from udev
146 rules which are annotated to match a static node
148 The default mode for a device node is 0600 now to match the kernel
149 created devtmpfs defaults. If GROUP= is specified and no MODE= is
150 given the default will be 0660.
156 Udev now gradually starts to pass control over the primary device nodes
157 and their names to the kernel, and will in the end only manage the
158 permissions of the node, and possibly create additional symlinks.
159 As a first step NAME="" will be ignored, and NAME= setings with names
160 other than the kernel provided name will result in a logged warning.
161 Kernels that don't provide device names, or devtmpfs is not used, will
162 still work as they did before, but it is strongly recommended to use
163 only the same names for the primary device node as the recent kernel
164 provides for all devices.
168 Fix broken firmware loader search path.
174 "udevadm trigger" defaults to "change" events now instead of "add"
175 events. The "udev boot script" might need to add "--action=add" to
176 the trigger command if not already there, in case the initial coldplug
177 events are expected as "add" events.
179 The option "all_partitons" was removed from udev. This should not be
180 needed for usual hardware. Udev can not safely make assumptions
181 about non-existing partition major/minor numbers, and therefore no
182 longer provide this unreliable and unsafe option.
184 The option "ignore_remove" was removed from udev. With devtmpfs
185 udev passed control over device nodes to the kernel. This option
186 should not be needed, or can not work as advertised. Neither
187 udev nor the kernel will remove device nodes which are copied from
188 the /lib/udev/devices/ directory.
190 All "add|change" matches are replaced by "!remove" in the rules and
191 in the udev logic. All types of events will update possible symlinks
192 and permissions, only "remove" is handled special now.
194 The modem modeswitch extra was removed and the external usb_modeswitch
195 program should be used instead.
197 New and fixed keymaps.
207 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
208 depend on the current sysfs layout and the information not available in the
209 deprecated layout. All remaining support for the deprecated sysfs layout is
214 Fix for a possible endless loop in the new input_id program.
220 The option "ignore_device" does no longer exist. There is no way to
221 ignore an event, as libudev events can not be suppressed by rules.
222 It only prevented RUN keys from being executed, which results in an
223 inconsistent behavior in current setups.
225 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
226 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
229 The support for the deprecated IDE devices has been removed from the
230 default set of rules. Distros who still care about non-libata drivers
231 need to add the rules to the compat rules file.
233 The ID_CLASS property on input devices has been replaced by the more accurate
234 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
235 determined by the new "input_id" prober now. Some devices, such as touchpads,
236 can have several classes. So if you previously had custom udev rules which e. g.
237 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
238 ENV{ID_INPUT_KEYBOARD}=="?*".
244 To support DEVPATH strings larger than the maximum file name length, the
245 private udev database format has changed. If some software still reads the
246 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
247 Please do not port anything to the new format again, everything in /dev/.udev
248 is and always was private to udev, and may and will change any time without
251 Multiple devices claiming the same names in /dev are limited to symlinks
252 only now. Mixing identical symlink names and node names is not supported.
253 This reduces the amount of data in the database significantly.
255 NAME="%k" causes a warning now. It's is and always was completely superfluous.
256 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
259 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
260 if they are not the default. To support older kernels, the NAME= rules need to
261 be added to the compat rules file.
263 Symlinks to udevadm with the old command names are no longer resolved to
264 the udevadm commands.
266 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
269 The option "last_rule" does no longer exist. Its use breaks too many
270 things which expect to be run from independent later rules, and is an idication
271 that something needs to be fixed properly instead.
273 The gudev API is no longer marked as experimental,
274 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
275 is enabled by default now. Various projects already depend on introspection
276 information to bind dynamic languages to the gudev interfaces.
282 The udevadm trigger "--retry-failed" option, which is replaced since quite
283 a while by "--type=failed" is removed.
285 The failed tracking was not working at all for a few releases. The RUN
286 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
287 default is not to track any failing RUN executions.
289 New keymaps, new modem, hid2hci updated.
293 Fix possible crash in udevd when worker processes are busy, rules are
294 changed at the same time, and workers get killed to reload the rules.
300 Properties set with ENV{.FOO}="bar" are marked private by starting the
301 name with a '.'. They will not be stored in the database, and not be
302 exported with the event.
304 Firmware files are looked up in:
305 /lib/firmware/updates/$(uname -r)
306 /lib/firmware/updates
307 /lib/firmware/$(uname -r)
311 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
312 ata_id, instead of scsi_id, is the default tool now for ATA devices.
318 The configure options have changed because another library needs to be
319 installed in a different location. Instead of exec_prefix and udev_prefix,
320 libdir, rootlibdir and libexecdir are used. The Details are explained in
323 Event processes now get re-used after they handled an event. This reduces
324 the number of forks and the pressure on the CPU significantly, because
325 cloned event processes no longer cause page faults in the main daemon.
326 After the events have settled, a few worker processes stay around for
327 future events, all others get cleaned up.
329 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
330 Also inotify support is mandatory now to run udev.
332 The format of the queue exported by the udev damon has changed. There is
333 no longer a /dev/.udev/queue/ directory. The current event queue can be
334 accessed with udevadm settle and libudedv.
336 Libudev does not have the unstable API header anymore. From now on,
337 incompatible changes will be handled by bumping the library major version.
339 To build udev from the git tree gtk-doc is needed now. The tarballs will
340 build without it and contain the pre-built documentation. An online copy
342 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
344 The tools from the udev-extras repository have been merged into the main
345 udev repository. Some of the extras have larger external dependencies, and
346 they can be disabled with the configure switch --disable-extras.
352 The program vol_id and the library libvolume_id are removed from the
353 repository. Libvolume_id is merged with libblkid from the util-linux-ng
354 package. Persistent disk links for label and uuid depend on the
355 util-linux-ng version (2.15) of blkid now. Older versions of blkid
356 can not be used with udev.
358 Libudev allows to subscribe to udev events. To prevent unwanted messages
359 to be delivered, and waking up the subscribing process, a filter can be
360 installed, to drop messages inside a kernel socket filter. The filters
361 match on the <subsytem>:<devtype> properties of the device.
362 This is part of the ongoing effort to replace HAL, and switch current
363 users over to directly use libudev.
364 Libudev is still marked as experimental, and its interface might
365 eventually change if needed, but no major changes of the currently exported
366 interface are expected anymore, and a first stable release should happen
369 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
370 is not supported since while and udevd will log an error message at
371 startup. It should still be able to boot-up, but advanced rules and system
372 services which depend on the information not available in the old sysfs
373 format will fail to work correctly.
375 DVB device naming is supplied by the kernel now. In case older kernels
376 need to be supported, the old shell script should be added to a compat
383 The processed udev events get send back to the netlink socket. Libudev
384 provides access to these events. This is work-in-progress, to replace
385 the DeviceKit daemon functionality directly with libudev. There are
386 upcoming kernel changes to allow non-root users to subcribe to these
393 "udevadm settle" now optionally accepts a range of events to wait for,
394 instead of waiting for "all" events.
400 The installed watch for block device metadata changes is now removed
401 during event hadling, because some (broken) tools may be called from udev
402 rules and (wrongly) open the device with write access. After the finished
403 event handling the watch is restored.
409 Device nodes can be watched for changes with inotify with OPTIONS="watch".
410 If closed after being opened for writing, a "change" uevent will occur.
411 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
417 The udevadm test command has no longer a --force option, nodes and symlinks
418 are always updated with a test run now.
420 The udevd daemon can be started with --resolve-names=never to avoid all user
421 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
422 lookup user and groups every time events are handled.
428 We are currently merging the Ubuntu rules in the udev default rules,
429 and get one step closer to provide a common Linux /dev setup, regarding
430 device names, symlinks, and default device permissions. On udev startup,
431 we now expect the following groups to be resolvable to their ids with
433 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
434 LDAP setups need to make sure, that these groups are always resolvable at
435 bootup, with only the rootfs mounted, and without network access available.
437 Some systems may need to add some new, currently not used groups, or need
438 to add some users to new groups, but the cost of this change is minimal,
439 compared to the pain the current, rather random, differences between the
440 various distributions cause for upstream projects and third-party vendors.
442 In general, "normal" users who log into a machine should never be a member
443 of any such group, but the device-access should be managed by dynamic ACLs,
444 which get added and removed for the specific users on login/logout and
445 session activity/inactivity. These groups are only provided for custom setups,
446 and mainly system services, to allow proper privilege separation.
447 A video-streaming daemon uid would be a member of "audio" and "video", to get
448 access to the sound and video devices, but no "normal" user should ever belong
449 to the "audio" group, because he could listen to the built-in microphone with
450 any ssh-session established from the other side of the world.
452 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
453 which do not depend on the kernel device name. As usual, unique
454 devices - only a single one per product connected, or a real
455 USB serial number in the device - are always found with the same
456 name in the by-id/ directory.
457 Completely identical devices may overwrite their names in by-id/
458 and can only be found reliably in the by-path/ directory. Devices
459 specified by by-path/ must not change their connection, like the
460 USB port number they are plugged in, to keep their name.
462 To support some advanced features, Linux 2.6.22 is the oldest supported
463 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
464 supported. Older kernels should still work, and devices nodes should be
465 reliably created, but some rules and libudev will not work correctly because
466 the old kernels do not provide the expected information or interfaces.
472 Fix for a possible segfault while swapping network interface names in udev
479 The group "video" is part of the default rules now.
483 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
484 block devices in some cases. No common distro uses this option anymore,
485 and we do not get enough testing for this and recent udev versions. If
486 this option is not needed to run some old distro with a new kernel,
487 it should be disabled in the kernel config.
489 Bugfix for the $links substitution variable, which may crash if no links
490 are created. This should not happen in usual setups because we always
491 create /dev/{block,char}/ links.
493 The strings of the parsed rules, which are kept in memory, no longer
494 contain duplicate entries, or duplicate tails of strings. This, and the
495 new rules parsing/matching code reduces the total in-memory size of
496 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
499 The export of DEVTYPE=disk/partition got removed from the default
500 rules. This value is available from the kernel. The pnp shell script
501 modprobe hack is removed from the default rules. ACPI devices have _proper_
502 modalias support and take care of the same functionality.
503 Installations which support old kernels, but install current default
504 udev rules may want to add that to the compat rules file.
506 Libvolume_id now always probes for all known filesystems, and does not
507 stop at the first match. Some filesystems are marked as "exclusive probe",
508 and if any other filesytem type matches at the same time, libvolume_id
509 will, by default, not return any probing result. This is intended to prevent
510 mis-detection with conflicting left-over signatures found from earlier
511 file system formats. That way, we no longer depend on the probe-order
512 in case of multiple competing signatures. In some setups the kernel allows
513 to mount a volume with just the old filesystem signature still in place.
514 This may damage the new filesystem and cause data-loss, just by mounting
515 it. Because volume_id can not decide which one the correct signature is,
516 the wrong signatures need to be removed manually from the volume, or the
517 volume needs to be reformatted, to enable filesystem detection and possible
522 Fix segfault if compiled without optimization and dbg() does not get
523 compiled out and uses variables which are not available.
527 Bugfixes. (And maybe new bugs. :))
529 The rule matching engine got converted from a rule list to a token
530 array which reduced the in-memory rules representation of a full
531 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
532 Limits like 5 ENV and ATTR matches, and one single instance for most
533 other keys per rule are gone.
535 The NAME assignment is no longer special cased. If later rules assign
536 a NAME value again, the former value will be overwritten. As usual
537 for most other keys, the NAME value can be protected by doing a final
538 assignment with NAME:="<value>".
540 All udev code now uses libudev, which is also exported. The library
541 is still under development, marked as experimental, and its interface
542 may change as long as the DeviceKit integration is not finished.
544 Many thanks to Alan Jenkins for his continuous help, and finding and
545 optimizing some of the computing expensive parts.
551 Kernel devices and device nodes are connected now by reverse indizes in
552 /sys and /dev. A device number retrieved by a stat() or similar, the
553 kernel device directory can be found by looking up:
554 /sys/dev/{block,char}/<maj>:<min>
555 and the device node of the same device by looking up:
556 /dev/{block,char}/<maj>:<min>
560 Fix recently introduced bug, which caused a compilation without large
561 file support, where vol_id does not recognize raid signatures at the end
564 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
565 Seems some kernel versions prevent the creation of the ieee-* links,
566 so people used the scsi-* link which disappeared now.
568 More libudev work. Almost all udevadm functionality comes from libudev
571 udevadm trigger has a new option --type, which allows to trigger events
572 for "devices", for "subsystems", or "failed" devices. The old option
573 --retry-failed" still works, but is no longer mentioned in the man page.
579 The udevadm info --device-id-of-file= output has changed to use
580 the obvious format. Possible current users should use the --export
581 option which is not affected.
583 The old udev commands symlinks to udevadm are not installed, if
584 these symlinks are used, a warning is printed.
590 Optical drive's media is no longer probed for raid signatures,
591 reading the end of the device causes some devices to malfunction.
592 Also the offset of the last session found is used now to probe
595 The volume_id library got a major version number update to 1,
596 some deprecated functions are removed.
598 A shared library "libudev" gets installed now to provide access
599 to udev device information. DeviceKit, the successor of HAL, will
600 need this library to access the udev database and search sysfs for
602 The library is currently in an experimental state, also the API is
603 expected to change, as long as the DeviceKit integration is not
608 We use ./configure now. See INSTALL for details. Current
611 "/usr" - prefix for man pages, include files
613 "" - the root filesystem, prefix for libs and binaries
617 "lib" - directory name for libraries, not a path name
618 multilib 64bit systems may use "lib64" instead of "lib"
620 compile-in verbose debug messages
622 disable all logging and compile-out all log strings
624 link against SELInux libraries, to set the expected context
627 In the default rules, the group "disk" gets permissions 0660 instead
628 of 0640. One small step closer to unify distro rules. Some day, all
629 distros hopefully end up with the same set of rules.
631 No symlinks to udevadm are installed anymore, if they are still needed,
632 they should be provided by the package.
638 Default udev rules, which are not supposed to be edited by the user, should
639 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
640 the udev package and will be replaced with an update. Udev will pick up rule
642 /lib/udev/rules.d/ - default installed rules
643 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
644 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
645 It does not matter in which directory a rule file lives, all files are sorted
648 To help creating /dev/root, we have now:
649 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
652 In case the current --device-id-of-file is already used, please switch to
653 the --export format version, it saves the output parsing and the old
654 format will be changed to use ':' as a separator, like the format in the
659 Fix cdrom_id to properly recognize blank media.
665 Tape drive id-data is queried from /dev/bsg/* instead of the tape
666 nodes. This avoids rewinding tapes on open().
672 The symlinks udevcontrol and udevtrigger are no longer installed by
675 The scsi_id program does not depend on sysfs anymore. It can speak
676 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
677 data, which should solve some old problems with tape devices, where
678 we better do not open all tape device nodes to identify the device.
684 The cdrom_id program is replaced by an advanced version, which can
685 detect most common device types, and also properties of the inserted
686 media. This is part of moving some basic functionality from HAL into
687 udev (and the kernel).
693 The last WAIT_FOR_SYSFS rule is removed from the default rules.
695 The symlinks to udevadm for the debugging tools: udevmonitor and
696 udevtest are no longer created.
698 The symlinks to the udevadm man page for the old tool names are
701 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
702 should be prefixed with '@' to indicate that the path is not a
713 Udevstart is removed from the tree, it did not get installed for
714 a long time now, and is long replaced by trigger and settle.
720 All udev tools are merged into a single binary called udevadm.
721 The old names of the tools are built-in commands in udevadm now.
722 Symlinks to udevadm, with the names of the old tools, provide
723 the same functionality as the standalone tools. There is also
724 only a single udevadm.8 man page left for all tools.
726 Tools like mkinitramfs should be checked, if they need to include
727 udevadm in the list of files.
737 The etc/udev/rules.d/ directory now contains a default set of basic
738 udev rules. This initial version is the result of a rules file merge
739 of Fedora and openSUSE. For these both distros only a few specific
740 rules are left in their own file, named after the distro. Rules which
741 are optionally installed, because they are only valid for a specific
742 architecture, or rules for subsystems which are not always used are
743 in etc/udev/packages/.
749 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
750 actions by dynamically created rules.
752 SYMLINK=="<value>" matches agains the entries in the list of
753 currently defined symlinks. The links are not created in the
754 filesystem at that point in time, but the values can be matched.
756 RUN{ignore_error}+="<program>" will ignore any exit code from the
757 program and not record as a failed event.
763 Final merge of patches/features from the Ubuntu package.
769 Control characters in filesystem label strings are no longer silenty
770 removed, but hex-encoded, to be able to uniquely identify the device
771 by its symlink in /dev/disk/by-label/.
772 If libvolume_id is used by mount(8), LABEL= will work as expected,
773 if slashes or other characters are used in the label string.
775 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
776 can be specified now. The TEST key accepts an optional mode mask
777 TEST{0100}=="<is executable file>".
779 Scsi_id now supports a mode without expecting scsi-specific sysfs
780 entries to allow the extraction of cciss-device persistent properties.
786 In the future, we may see uuid's which are just simple character
787 strings (see the DDF Raid Specification). For that reason vol_id now
788 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
789 the creation of symlinks, the *_SAFE values ensure, that no control
790 or whitespace characters are used in the filename.
792 Possible users of libvolume_id, please use the volume_id_get_* functions.
793 The public struct will go away in a future release of the library.
799 Removal of useless extras/eventrecorder.sh.
809 The directory multiplexer for dev.d/ and hotplug.d are finally removed
810 from the udev package.
816 Symlinks can have priorities now, the priority is assigned to the device
817 and specified with OPTIONS="link_priority=100". Devices with higher
818 priorities overwrite the symlinks of devices with lower priorities.
819 If the device that currently owns the link, goes away, the symlink
820 will be removed, and recreated, pointing to the next device with the
821 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
822 more reliable, if multiple devices contain the same metadata and overwrite
825 The dasd_id program is removed from the udev tree, and dasdinfo, with the
826 needed rules, are part of the s390-tools now.
828 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
829 we may get the scsi sysfs mess fixed some day, and this will only catch
830 the devices we are looking for.
832 USB serial numbers for storage devices have the target:lun now appended,
833 to make it possibble to distinguish broken multi-lun devices with all
834 the same SCSI identifiers.
836 Note: The extra "run_directory" which searches and executes stuff in
837 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
838 with the next release. Make sure, that you don't use it anymore, or
839 provides your own implementation of that inefficient stuff.
840 We are tired of reports about a "slow udev", because these directories
841 contain stuff, that runs with _every_ event, instead of using rules,
842 that run programs only for the matching events.
852 DRIVER== will match only for devices that actually have a real
853 driver. DRIVERS== must be used, if parent devices should be
854 included in the match.
856 Libvolume_id's "linux_raid" detection needed another fix.
864 Add additional check to volume_id detection of via_raid, cause
865 some company decided to put a matching pattern all over the empty
866 storage area of their music players.
870 Fix path_id for SAS devices.
874 The udev daemon can be started with --debug-trace now, which will
875 execute all events serialized to get a chance to catch a possible
876 action that crashes the box.
878 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
879 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
880 are excluded from the warning. Referencing parent attributes directly
881 may break when something in the kernel driver model changes. Udev will
882 just find the attribute by walking up the parent chain.
884 Udevtrigger now sorts the list of devices depending on the device
885 dependency, so a "usb" device is triggered after the parent "pci"
890 Revert persistent-storage ata-serial '_' '-' replacement.
896 Udevtrigger can now filter the list of devices to be triggered. Matches
897 for subsystems or sysfs attributes can be specified.
899 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
900 zero-sized files to avoid pointing to /sys and confuse broken tools which
901 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
904 The rules and scripts to create udev rules for persistent network
905 devices and optical drives are in the extras/rules_generator directory
906 now. If you use something similar, please consider replacing your own
907 version with this, to share the support effort. The rule_generator
908 installs its own rules into /etc/udev/rules.d.
910 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
911 the rule_generator depends on cdrom_id to be called in an earlier rule.
917 Renaming of some key names (the old names still work):
918 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
919 (The behavior of the key DRIVER will change soon in one of the next
920 releases, to match only the event device, please switch to DRIVERS
921 instead. If DRIVER is used, it will behave like DRIVERS, but an error
923 With the new key names, we have a more consistent and simpler scheme.
924 We can match the properties of the event device only, with: KERNEL,
925 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
926 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
927 longer mentioned in the man page and should be switched in the rule
930 ATTR{file}="value" can be used now, to write to a sysfs file of the
931 event device. Instead of:
932 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
934 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
936 All the PHYSDEV* keys are deprecated and will be removed from a
938 PHYDEVPATH - is the path of a parent device and should not be
940 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
941 matched with SUBSYSTEMS==
942 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
943 Newer kernels will have DRIVER in the environment,
944 for older kernels udev puts in. Class device will
945 no longer carry this property of a parent and
946 DRIVERS== can be used to match such a parent value.
947 Note that ENV{DRIVER} is only available for a few bus devices, where
948 the driver is already bound at device event time. On coldplug, the
949 events for a lot devices are already bound to a driver, and they will have
950 that value set. But on hotplug, at the time the kernel creates the device,
951 it can't know what driver may claim the device after that, therefore
952 in most cases it will be empty.
954 Failed events should now be re-triggered with:
955 udevtrigger --retry-failed.
956 Please switch to this command, so we keep the details of the /dev/.udev/failed/
957 files private to the udev tools. We may need to switch the current symlink
958 target, cause some obviously broken tools try to scan all files in /dev
959 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
960 million times. This takes ages on slow boxes.
962 The udevinfo attribute walk (-a) now works with giving a device node
963 name (-n) instead of a devpath (-p). The query now always works, also when
964 no database file was created by udev.
966 The built-in /etc/passwd /etc/group parser is removed, we always depend on
967 getpwnam() and getgrnam() now. One of the next releases will depend on
968 fnmatch() and may use getopt_long().
972 Bugfixes and small improvements.
976 Fix path_id for recent kernels.
982 Added support for swapping network interface names, by temporarily
983 renaming the device and wait for the target name to become free.
987 The built-in MODALIAS key and substitution is removed.
991 The binary firmware helper is replaced by the usual simple
992 shell script. Udevsend is removed from the tree.
1000 Some more keys require the correct use of '==' and '=' depending
1001 on the kind of operation beeing an assignment or a match. Rules
1002 with invalid operations are skipped and logged to syslog. Please
1003 test with udevtest if the parsing of your rules throws errors and
1004 fix possibly broken rules.
1008 Provide "udevsettle" to wait for all current udev events to finish.
1009 It also watches the current kernel netlink queue by comparing the
1010 even sequence number to make sure that there are no current pending
1011 events that have not already arrived in the daemon.
1015 Fix rule to skip persistent rules for removable IDE devices, which
1016 also skipped optical IDE drives.
1018 All *_id program are installed in /lib/udev/ by default now.
1020 No binary is stripped anymore as this should be done in the
1021 packaging process and not at build time.
1023 libvolume_id is provided as a shared library now and vol_id is
1024 linked against it. Also one of the next HAL versions will require
1025 this library, and the HAL build process will also require the
1026 header file to be installed. The copy of the same code in HAL will
1027 be removed to have only a single copy left on the system.
1031 Add persistent links for SCSI tapes. The rules file is renamed
1032 to 60-persistent-storage.rules.
1034 Create persistent path for usb devices. Can be used for all sorts
1035 of devices that can't be distinguished by other properties like
1036 multiple identical keyboards and mice connected to the same box.
1038 Provide "udevtrigger" program to request events on coldplug. The
1039 shell script is much too slow with thousends of devices.
1043 Fix persistent disk rules to exclude removable IDE drives.
1045 Warn if %e, $modalias or MODALIAS is used.
1049 Fix queue export, which wasn't correct for subsequent add/remove
1050 events for the same device.
1054 Fix cramfs detection on big endian.
1056 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1061 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1062 attributes were only checked at the parent device that matched the
1063 by BUS requested subsystem. Fix it to also look at the device we
1064 received the event for.
1066 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1071 Fix a bug where NAME="" would prevent RUN from beeing executed.
1073 RUN="/bin/program" does not longer automatically add the subsystem
1074 as the first parameter. This is from the days of /sbin/hotplug
1075 which is dead now and it's just confusing to need to add a space at
1076 the end of the program name to prevent this.
1077 If you use rules that need the subsystem as the first parameter,
1078 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1079 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1083 The udev man page has moved to udev(7) as it does not describe a command
1084 anymore. The programs udev, udevstart and udevsend are no longer installed
1085 by default and must be copied manually, if they should be installed or
1086 included in a package.
1088 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1089 the ignore rule was applied.
1091 More preparation for future sysfs changes. usb_id and scsi_id no longer
1092 depend on a magic order of devices in the /devices chain. Specific devices
1093 should be requested by their subsytem.
1095 This will always find the scsi parent device without depending on a specific
1097 dev = sysfs_device_get(devpath);
1098 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1100 The "device" link in the current sysfs layout will be automatically
1101 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1102 parent in the devpath. If a device is requested by it's symlink, like all
1103 class devices in the new sysfs layout will look like, it gets automatically
1104 resolved and substituted with the real devpath and not the symlink path.
1107 A similar logic must be applied to _all_ sysfs users, including
1108 scripts, that search along parent devices in sysfs. The explicit use of
1109 the "device" link must be avoided. With the future sysfs layout all
1110 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1111 back to the "class" or the "bus". The layout of the parent devices in
1112 /devices is not necessarily expected to be stable across kernel releases and
1113 searching for parents by their subsystem should make sysfs users tolerant
1114 for changed parent chains.
1118 Prepare udev to work with the experimental kernel patch, that moves
1119 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1121 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1122 moving the class devices to /sys/devices.
1124 Thanks again to Marco for help finding a hopefully nice compromise
1125 to make %b simpler and working again.
1129 Complete removal of libsysfs, replaced by simple helper functions
1130 which are much simpler and a bit faster. The udev daemon operatesentirely
1131 on event parameters and does not use sysfs for simple rules anymore.
1132 Please report any new bugs/problems, that may be caused by this big
1133 change. They will be fixed immediately.
1135 The enumeration format character '%e' is deprecated and will be
1136 removed sometimes from a future udev version. It never worked correctly
1137 outside of udevstart, so we can't use it with the new parallel
1138 coldplug. A simple enumeration is as useless as the devfs naming
1139 scheme, just get rid of both if you still use it.
1141 MODALIAS and $modalias is not needed and will be removed from one of
1142 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1143 the sysfs "modalias" value.
1145 Thanks a lot to Marco for all his help on finding and fixing bugs.
1149 Let scsi_id request libata drive serial numbers from page 0x80.
1151 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1152 added /dev/disk/by-name/* for device mapper device names.
1154 Removed %e from the man page. It never worked reliably outside
1155 of udevstart and udevstart is no longer recommended to use.
1159 Symlinks are now exported to the event environment. Hopefully it's no
1160 longer needed to run udevinfo from an event process, like it was
1161 mentioned on the hotplug list:
1162 UDEV [1134776873.702967] add@/block/sdb
1165 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1169 Fix a problem if udevsend is used as the hotplug handler and tries to use
1170 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1171 and this kind of problems will hopefully go away soon.
1175 All built-in logic to work around bad sysfs timing is removed with this
1176 version. The need to wait for sysfs files is almost fixed with a kernel
1177 version that doesn't work with this udev version anyway. Until we fix
1178 the timing of the "bus" link creation, the former integrated logic should
1179 be emulated by a rule placed before all other rules:
1180 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1182 The option "udev_db" does no longer exist. All udev state will be in
1183 /$udev_root/.udev/ now, there is no longer an option to set this
1185 If the init script or something else used this value, just depend on
1186 this hardcoded path. But remember _all_content_ of this directory is
1187 still private to udev and can change at any time.
1189 Default location for rule sripts and helper programs is now: /lib/udev/.
1190 Everything that is not useful on the commandline should go into this
1191 directory. Some of the helpers in the extras folder are installed there
1192 now. The rules need to be changed, to find the helpers there.
1194 Also /lib/udev/devices is recommended as a directory where packages or
1195 the user can place real device nodes, which get copied over to /dev at
1196 every boot. This should replace the various solutions with custom config
1199 Udevsend does no longer start the udev daemon. This must be done with
1200 the init script that prepares /dev on tmpfs and creates the initial nodes,
1201 before starting the daemon.
1205 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1208 The copy of klibc is removed. A systemwide installed version of klibc
1209 should be used to build a klibc udev now.
1213 NAME="" will not create any nodes, but execute RUN keys. To completely
1214 ignore an event the OPTION "ignore_device" should be used.
1216 After removal of the reorder queue, events with a TIMEOUT can be executed
1217 without any queuing now.
1221 Fixed bug in udevd, if inotify is not available. We depend on netlink
1222 uevents now, kernels without that event source will not work with that
1223 version of udev anymore.
1227 The rule parsing happens now in the daemon once at startup, all udev
1228 event processes inherit the already parsed rules from the daemon.
1229 It is shipped with SUSE10.0 and reduces heavily the system load at
1230 startup. The option to save precompiled rules and let the udev process
1231 pick the them up is removed, as it's no longer needed.
1233 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1234 device. Libsysfs is changed to "translate" the requested link into the
1235 real device path, as it would happen with the hotplug event. Otherwise
1236 device removal and the udev database will not work.
1238 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1241 A few improvements for vol_id, the filesytem probing code.
1245 Fix a stupid typo in extras/run_directory for "make install".
1247 scsi_id creates the temporary devnode now in /dev for usage with a
1248 non-writable /tmp directory.
1250 The uevent kernel socket buffer can carry app. 50.000 events now,
1251 let's see who can break this again. :)
1253 The upcoming kernel will have a new input driver core integration.
1254 Some class devices are now symlinks to the real device. libsysfs
1255 needs a fix for this to work correctly. Udevstart of older udev
1256 versions will _not_ create these devices!
1260 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1265 A bunch of mostly trivial bugfixes. From now on no node name or
1266 symlink name can contain any character than plain whitelisted ascii
1267 characters or validated utf8 byte-streams. This is needed for the
1268 /dev/disk/by-label/* links, because we import untrusted data and
1269 export it to the filesystem.
1273 More bugfixes. If udevd was started from the kernel, we don't
1274 have stdin/stdout/stderr, which broke the forked tools in some
1279 Bugfix. udevstart event ordering was broken for a long time.
1280 The new run_program() uncovered it, because /dev/null was not
1281 available while we try to run external programs.
1282 Now udevstart should create it before we run anything.
1286 Minor bugfixes and some distro rules updates. If you don't have the
1287 persistent disk rules in /dev/disk/by-*/* on your distro, just
1288 grab it from here. :)
1292 We can use socket communication now to pass events from udev to
1294 RUN+="socket:/org/freedesktop/hal/udev_event"
1295 will pass the whole udev event to the HAL daemon without the need
1296 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1300 Mostly bugfixes and see ChangeLog.
1302 The test for the existence of an environment value should be
1304 ENV{KEY}=="*" to ENV{KEY}=="?*"
1305 because "*" will not fail anymore, if the key does not exist or
1310 Bugfixes and a few tweaks described in the ChangeLog.
1314 Mostly a Bugfix release.
1316 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1317 timing with custom rules.
1321 We changed the internal rule storage format. Our large rule files took
1322 2 MB of RAM, with the change we are down to 99kB.
1324 If the device-node has been created with default name and no symlink or
1325 options are to remenber, it is not longer stored in the udevdb. HAL will
1326 need to be updated to work correctly with that change.
1328 To overrride optimization flags, OPTFLAGS may be used now.
1336 Major changes happened with this release. The goal is to take over the
1337 complete kernel-event handling and provide a more efficient way to dispatch
1338 kernel events. Replacing most of the current shell script logic and the
1339 kernel forked helper with a netlink-daemon and a rule-based event handling.
1341 o udevd listens to netlink events now. The first valid netlink event
1342 will make udevd ignore any message from udevsend that contains a
1343 SEQNUM, to avoid duplicate events. The forked events can be disabled
1345 echo "" > /proc/sys/kernel/hotplug
1346 For full support, the broken input-subsytem needs to be fixed, not to
1347 bypass the driver core.
1349 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1350 removed from udev itself and must be emulated by calling small
1351 helper binaries provided in the extras folder:
1352 make EXTRAS=extras/run_directory/
1353 will build udev_run_devd and udev_run_hotplugd, which can be called
1354 from a rule if needed:
1355 RUN+="/sbin/udev_run_hotplugd"
1356 The recommended way to handle this is to convert all the calls from
1357 the directories to explicit udev rules and get completely rid of the
1358 multiplexing. (To catch a ttyUSB event, you now no longer need to
1359 fork and exit 300 tty script instances you are not interested in, it
1360 is just one rule that matches exactly the device.)
1362 o udev handles now _all_ events not just events for class and block
1363 devices, this way it is possible to control the complete event
1364 behavior with udev rules. Especially useful for rules like:
1365 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1367 o As used in the modalias rule, udev supports now textual
1368 substitution placeholder along with the usual format chars. This
1369 needs to be documented, for now it's only visible in udev_rules_parse.c.
1371 o The rule keys support now more operations. This is documented in the
1372 man page. It is possible to add values to list-keys like the SYMLINK
1373 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1374 Also "final"-assignments are supported by using KEY:="value", which will
1375 prevent changing the key by any later rule.
1377 o kernel 2.6.12 has the "detached_state" attribute removed from
1378 sysfs, which was used to recognize sysfs population. We switched that
1379 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1380 Running this udev version on older kernels may cause a short delay for
1383 o To provide infrastructure for persistent device naming, the id programs:
1384 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1385 to export the probed data in environment key format:
1386 pim:~ # /sbin/ata_id --export /dev/hda
1387 ID_MODEL=HTS726060M9AT00
1388 ID_SERIAL=MRH401M4G6UM9B
1389 ID_REVISION=MH4OA6BA
1391 The following rules:
1392 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1393 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1396 kay@pim:~> tree /dev/disk
1399 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1400 | `-- IBM-Memory_Key -> ../../sda
1402 | |-- swap -> ../../hda1
1403 | |-- date -> ../../sda1
1404 | `-- home -> ../../hda3
1406 |-- 2E08712B0870F2E7 -> ../../hda3
1407 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1408 |-- E845-7A89 -> ../../sda1
1409 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1411 The IMPORT= operation will import these keys in the environment and make
1412 it available for later PROGRAM= and RUN= executed programs. The keys are
1413 also stored in the udevdb and can be queried from there with one of the
1416 o A few binaries are silently added to the repository, which can be used
1417 to replay kernel events from initramfs instead of using coldplug. udevd
1418 can be instructed now to queue-up events while the stored events from
1419 initramfs are filled into the udevd-queue. This code is still under
1420 development and there is no documentation now besides the code itself.
1421 The additional binaries get compiled, but are not installed by default.
1423 o There is also a temporary fix for a performance problem where too many
1424 events happen in parallel and every event needs to parse the rules.
1425 udev can now read precompiled rules stored on disk. This is likely to be
1426 replaced by a more elegant solution in a future udev version.
1430 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1431 Fix for libsysfs not to expect this file was added.
1435 All rules are applied now, but only the first matching rule with a NAME-key
1436 will be applied. All later rules with NAME-key are completely ignored. This
1437 way system supplied symlinks or permissions gets applied to user-defined
1441 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1442 to some rules, to keep the old behavior.
1444 The rules are read on "remove"-events too. That makes is possible to match
1445 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1446 instruct udev to ignore an event (OPTIONS="ignore_device").
1447 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1449 The new RUN-key supports rule-based execution of programs after device-node
1450 handling. This is meant as a general replacement for the dev.d/-directories
1451 to give fine grained control over the execution of programs.
1453 The %s{}-sysfs format char replacement values are searched at any of the
1454 devices in the device chain now, not only at the class-device.
1456 We support log priority levels now. The value udev_log in udev.conf is used
1457 to determine what is printed to syslog. This makes it possible to
1458 run a version with compiled-in debug messages in a production environment
1459 which is sometimes needed to find a bug.
1460 It is still possible to supress the inclusion of _any_ syslog usage with
1461 USE_LOG=false to create the smallest possible binaries if needed.
1462 The configured udev_log value can be overridden with the environment variable
1467 Possible use of a system-wide klibc:
1468 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1469 will link against an external klibc and our own version will be ignored.
1473 We support an unlimited count of symlinks now.
1475 If USE_STATIC=true is passed to a glibc build, we link statically and use
1476 a built-in userdb parser to resolve user and group names.
1478 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1479 we walk up the chain of physical devices to find a match.
1481 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1482 easy to skip certain attribute matches without composing rules with weird
1483 character class negations like:
1484 KERNEL="[!s][!c][!d]*"
1485 this can now be replaced with:
1487 The current simple '=' is still supported, and should work as it does today,
1488 but existing rules should be converted if possible, to be better readable.
1490 We have new ENV{}== key now, to match against a maximum of 5 environment
1493 udevstart is its own binary again, because we don't need co carry this araound
1494 with every forked event.