3 Fix bug in control message handling, which can lead to a failing
4 udevadm control --exit. Thanks to Jürg Billeter for help tracking
11 We require at least Linux kernel 2.6.32 now. Some platforms might
12 require a later kernel that supports accept4() and similar, or
13 need to backport the trivial syscall wiring to the older kernels.
15 The hid2hci tool moved to the bluez package and was removed.
17 Many of the extras can be --enable/--disabled at ./configure
18 time. The --disable-extras option was removed. Some extras have
19 been disabled by default. The current options and their defaults
20 can be checked with './configure --help'.
26 Udev logs a warning now if /run is not writable at udevd
27 startup. It will still fall back to /dev/.udev, but this is
30 The running udev daemon can now cleanly shut down with:
31 udevadm control --exit
33 Udev in initramfs should clean the state of the udev database
34 with: udevadm info --cleanup-db which will remove all state left
35 behind from events/rules in initramfs. If initramfs uses
36 --cleanup-db and device-mapper/LVM, the rules in initramfs need
37 to add OPTIONS+="db_persist" for all dm devices. This will
38 prevent removal of the udev database for these devices.
40 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
41 120 seconds per process. If that timeout is reached the spawned
42 process will be killed. The event timeout can be overwritten with
45 If systemd is used, udev gets now activated by netlink data.
46 Systemd will bind the netlink socket which will buffer all data.
47 If needed, such setup allows a seemless update of the udev daemon,
48 where no event can be lost during a udevd update/restart.
49 Packages need to make sure to: systemctl stop udev.socket udev.service
50 or 'mask' udev.service during the upgrade to prevent any unwanted
51 auto-spawning of udevd.
52 This version of udev conflicts with systemd version below 25. The
53 unchanged service files will not wirk correctly.
59 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
60 /run mountpoint is supposed to be a tmpfs mounted during early boot,
61 available and writable to for all tools at any time during bootup,
62 it replaces /var/run/, which should become a symlink some day.
64 If /run does not exist, or is not writable, udev will fall back using
67 On systemd systems with initramfs and LVM used, packagers must
68 make sure, that the systemd and initramfs versions match. The initramfs
69 needs to create the /run mountpoint for udev to store the data, and
70 mount this tmpfs to /run in the rootfs, so the that the udev database
71 is preserved for the udev version started in the rootfs.
73 The command 'udevadm info --convert-db' is gone. The udev daemon
74 itself, at startup, converts any old database version if necessary.
76 The systemd services files have been reorganized. The udev control
77 socket is bound by systemd and passed to the started udev daemon.
78 The udev-settle.service is no longer active by default. Services which
79 can not handle hotplug setups properly need to actively pull it in, to
80 act like a barrier. Alternatively the settle service can be unconditionally
81 'systemctl'enabled, and act like a barrier for basic.target.
83 The fstab_import callout is no longer built or installed. Udev
84 should not be used to mount, does not watch changes to fstab, and
85 should not mirror fstab values in the udev database.
91 New and updated keymaps.
97 The udev database has changed, After installation of a new udev
98 version, 'udevadm info --convert-db' should be called, to let the new
99 udev/libudev version read the already stored data.
101 udevadm now supports quoting of property values, and prefixing of
103 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
106 MY_DEVNAME='/dev/sda'
110 libudev now supports:
111 udev_device_get_is_initialized()
112 udev_enumerate_add_match_is_initialized()
113 to be able to skip devices the kernel has created , but udev has
116 libudev now supports:
117 udev_device_get_usec_since_initialized()
118 to retrieve the "age" of a udev device record.
120 GUdev supports a more generic GUdevEnumerator class, udev TAG
121 handling, device initialization and timestamp now.
123 The counterpart of /sys/dev/{char,block}/$major:$minor,
124 /dev/{char,block}/$major:$minor symlinks are now unconditionally
125 created, even when no rule files exist.
127 New and updated keymaps.
133 GUdev moved from /usr to /.
143 Persistent network naming rules are disabled inside of Qemu/KVM now.
145 New and updated keymaps.
147 Udev gets unconditionally enabled on systemd installations now. There
148 is no longer the need to to run 'systemctl enable udev.service'.
162 New and fixed keymaps.
164 Install systemd service files if applicable.
170 All distribution specific rules are removed from the udev source tree,
171 most of them are no longer needed. The Gentoo rules which allow to support
172 older kernel versions, which are not covered by the default rules anymore
173 has moved to rules/misc/30-kernel-compat.rules.
179 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
180 was removed from udevd.
182 Udevd now checks the kernel commandline for the following variables:
183 udev.log-priority=<syslog priority>
184 udev.children-max=<maximum number of workers>
185 udev.exec-delay=<seconds to delay the execution of RUN=>
186 to help debuging coldplug setups where the loading of a kernel
187 module crashes the system.
189 The subdirectory in the source tree rules/packages has been renamed to
190 rules/arch, anc contains only architecture specific rules now.
200 Now the udev daemon itself, does on startup:
201 - copy the content of /lib/udev/devices to /dev
202 - create the standard symlinks like /dev/std{in,out,err},
203 /dev/core, /dev/fd, ...
204 - use static node information provided by kernel modules
205 and creates these nodes to allow module on-demand loading
206 - possibly apply permissions to all ststic nodes from udev
207 rules which are annotated to match a static node
209 The default mode for a device node is 0600 now to match the kernel
210 created devtmpfs defaults. If GROUP= is specified and no MODE= is
211 given the default will be 0660.
217 Udev now gradually starts to pass control over the primary device nodes
218 and their names to the kernel, and will in the end only manage the
219 permissions of the node, and possibly create additional symlinks.
220 As a first step NAME="" will be ignored, and NAME= setings with names
221 other than the kernel provided name will result in a logged warning.
222 Kernels that don't provide device names, or devtmpfs is not used, will
223 still work as they did before, but it is strongly recommended to use
224 only the same names for the primary device node as the recent kernel
225 provides for all devices.
229 Fix broken firmware loader search path.
235 "udevadm trigger" defaults to "change" events now instead of "add"
236 events. The "udev boot script" might need to add "--action=add" to
237 the trigger command if not already there, in case the initial coldplug
238 events are expected as "add" events.
240 The option "all_partitons" was removed from udev. This should not be
241 needed for usual hardware. Udev can not safely make assumptions
242 about non-existing partition major/minor numbers, and therefore no
243 longer provide this unreliable and unsafe option.
245 The option "ignore_remove" was removed from udev. With devtmpfs
246 udev passed control over device nodes to the kernel. This option
247 should not be needed, or can not work as advertised. Neither
248 udev nor the kernel will remove device nodes which are copied from
249 the /lib/udev/devices/ directory.
251 All "add|change" matches are replaced by "!remove" in the rules and
252 in the udev logic. All types of events will update possible symlinks
253 and permissions, only "remove" is handled special now.
255 The modem modeswitch extra was removed and the external usb_modeswitch
256 program should be used instead.
258 New and fixed keymaps.
268 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
269 depend on the current sysfs layout and the information not available in the
270 deprecated layout. All remaining support for the deprecated sysfs layout is
275 Fix for a possible endless loop in the new input_id program.
281 The option "ignore_device" does no longer exist. There is no way to
282 ignore an event, as libudev events can not be suppressed by rules.
283 It only prevented RUN keys from being executed, which results in an
284 inconsistent behavior in current setups.
286 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
287 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
290 The support for the deprecated IDE devices has been removed from the
291 default set of rules. Distros who still care about non-libata drivers
292 need to add the rules to the compat rules file.
294 The ID_CLASS property on input devices has been replaced by the more accurate
295 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
296 determined by the new "input_id" prober now. Some devices, such as touchpads,
297 can have several classes. So if you previously had custom udev rules which e. g.
298 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
299 ENV{ID_INPUT_KEYBOARD}=="?*".
305 To support DEVPATH strings larger than the maximum file name length, the
306 private udev database format has changed. If some software still reads the
307 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
308 Please do not port anything to the new format again, everything in /dev/.udev
309 is and always was private to udev, and may and will change any time without
312 Multiple devices claiming the same names in /dev are limited to symlinks
313 only now. Mixing identical symlink names and node names is not supported.
314 This reduces the amount of data in the database significantly.
316 NAME="%k" causes a warning now. It's is and always was completely superfluous.
317 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
320 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
321 if they are not the default. To support older kernels, the NAME= rules need to
322 be added to the compat rules file.
324 Symlinks to udevadm with the old command names are no longer resolved to
325 the udevadm commands.
327 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
330 The option "last_rule" does no longer exist. Its use breaks too many
331 things which expect to be run from independent later rules, and is an idication
332 that something needs to be fixed properly instead.
334 The gudev API is no longer marked as experimental,
335 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
336 is enabled by default now. Various projects already depend on introspection
337 information to bind dynamic languages to the gudev interfaces.
343 The udevadm trigger "--retry-failed" option, which is replaced since quite
344 a while by "--type=failed" is removed.
346 The failed tracking was not working at all for a few releases. The RUN
347 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
348 default is not to track any failing RUN executions.
350 New keymaps, new modem, hid2hci updated.
354 Fix possible crash in udevd when worker processes are busy, rules are
355 changed at the same time, and workers get killed to reload the rules.
361 Properties set with ENV{.FOO}="bar" are marked private by starting the
362 name with a '.'. They will not be stored in the database, and not be
363 exported with the event.
365 Firmware files are looked up in:
366 /lib/firmware/updates/$(uname -r)
367 /lib/firmware/updates
368 /lib/firmware/$(uname -r)
372 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
373 ata_id, instead of scsi_id, is the default tool now for ATA devices.
379 The configure options have changed because another library needs to be
380 installed in a different location. Instead of exec_prefix and udev_prefix,
381 libdir, rootlibdir and libexecdir are used. The Details are explained in
384 Event processes now get re-used after they handled an event. This reduces
385 the number of forks and the pressure on the CPU significantly, because
386 cloned event processes no longer cause page faults in the main daemon.
387 After the events have settled, a few worker processes stay around for
388 future events, all others get cleaned up.
390 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
391 Also inotify support is mandatory now to run udev.
393 The format of the queue exported by the udev damon has changed. There is
394 no longer a /dev/.udev/queue/ directory. The current event queue can be
395 accessed with udevadm settle and libudedv.
397 Libudev does not have the unstable API header anymore. From now on,
398 incompatible changes will be handled by bumping the library major version.
400 To build udev from the git tree gtk-doc is needed now. The tarballs will
401 build without it and contain the pre-built documentation. An online copy
403 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
405 The tools from the udev-extras repository have been merged into the main
406 udev repository. Some of the extras have larger external dependencies, and
407 they can be disabled with the configure switch --disable-extras.
413 The program vol_id and the library libvolume_id are removed from the
414 repository. Libvolume_id is merged with libblkid from the util-linux-ng
415 package. Persistent disk links for label and uuid depend on the
416 util-linux-ng version (2.15) of blkid now. Older versions of blkid
417 can not be used with udev.
419 Libudev allows to subscribe to udev events. To prevent unwanted messages
420 to be delivered, and waking up the subscribing process, a filter can be
421 installed, to drop messages inside a kernel socket filter. The filters
422 match on the <subsytem>:<devtype> properties of the device.
423 This is part of the ongoing effort to replace HAL, and switch current
424 users over to directly use libudev.
425 Libudev is still marked as experimental, and its interface might
426 eventually change if needed, but no major changes of the currently exported
427 interface are expected anymore, and a first stable release should happen
430 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
431 is not supported since while and udevd will log an error message at
432 startup. It should still be able to boot-up, but advanced rules and system
433 services which depend on the information not available in the old sysfs
434 format will fail to work correctly.
436 DVB device naming is supplied by the kernel now. In case older kernels
437 need to be supported, the old shell script should be added to a compat
444 The processed udev events get send back to the netlink socket. Libudev
445 provides access to these events. This is work-in-progress, to replace
446 the DeviceKit daemon functionality directly with libudev. There are
447 upcoming kernel changes to allow non-root users to subcribe to these
454 "udevadm settle" now optionally accepts a range of events to wait for,
455 instead of waiting for "all" events.
461 The installed watch for block device metadata changes is now removed
462 during event hadling, because some (broken) tools may be called from udev
463 rules and (wrongly) open the device with write access. After the finished
464 event handling the watch is restored.
470 Device nodes can be watched for changes with inotify with OPTIONS="watch".
471 If closed after being opened for writing, a "change" uevent will occur.
472 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
478 The udevadm test command has no longer a --force option, nodes and symlinks
479 are always updated with a test run now.
481 The udevd daemon can be started with --resolve-names=never to avoid all user
482 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
483 lookup user and groups every time events are handled.
489 We are currently merging the Ubuntu rules in the udev default rules,
490 and get one step closer to provide a common Linux /dev setup, regarding
491 device names, symlinks, and default device permissions. On udev startup,
492 we now expect the following groups to be resolvable to their ids with
494 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
495 LDAP setups need to make sure, that these groups are always resolvable at
496 bootup, with only the rootfs mounted, and without network access available.
498 Some systems may need to add some new, currently not used groups, or need
499 to add some users to new groups, but the cost of this change is minimal,
500 compared to the pain the current, rather random, differences between the
501 various distributions cause for upstream projects and third-party vendors.
503 In general, "normal" users who log into a machine should never be a member
504 of any such group, but the device-access should be managed by dynamic ACLs,
505 which get added and removed for the specific users on login/logout and
506 session activity/inactivity. These groups are only provided for custom setups,
507 and mainly system services, to allow proper privilege separation.
508 A video-streaming daemon uid would be a member of "audio" and "video", to get
509 access to the sound and video devices, but no "normal" user should ever belong
510 to the "audio" group, because he could listen to the built-in microphone with
511 any ssh-session established from the other side of the world.
513 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
514 which do not depend on the kernel device name. As usual, unique
515 devices - only a single one per product connected, or a real
516 USB serial number in the device - are always found with the same
517 name in the by-id/ directory.
518 Completely identical devices may overwrite their names in by-id/
519 and can only be found reliably in the by-path/ directory. Devices
520 specified by by-path/ must not change their connection, like the
521 USB port number they are plugged in, to keep their name.
523 To support some advanced features, Linux 2.6.22 is the oldest supported
524 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
525 supported. Older kernels should still work, and devices nodes should be
526 reliably created, but some rules and libudev will not work correctly because
527 the old kernels do not provide the expected information or interfaces.
533 Fix for a possible segfault while swapping network interface names in udev
540 The group "video" is part of the default rules now.
544 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
545 block devices in some cases. No common distro uses this option anymore,
546 and we do not get enough testing for this and recent udev versions. If
547 this option is not needed to run some old distro with a new kernel,
548 it should be disabled in the kernel config.
550 Bugfix for the $links substitution variable, which may crash if no links
551 are created. This should not happen in usual setups because we always
552 create /dev/{block,char}/ links.
554 The strings of the parsed rules, which are kept in memory, no longer
555 contain duplicate entries, or duplicate tails of strings. This, and the
556 new rules parsing/matching code reduces the total in-memory size of
557 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
560 The export of DEVTYPE=disk/partition got removed from the default
561 rules. This value is available from the kernel. The pnp shell script
562 modprobe hack is removed from the default rules. ACPI devices have _proper_
563 modalias support and take care of the same functionality.
564 Installations which support old kernels, but install current default
565 udev rules may want to add that to the compat rules file.
567 Libvolume_id now always probes for all known filesystems, and does not
568 stop at the first match. Some filesystems are marked as "exclusive probe",
569 and if any other filesytem type matches at the same time, libvolume_id
570 will, by default, not return any probing result. This is intended to prevent
571 mis-detection with conflicting left-over signatures found from earlier
572 file system formats. That way, we no longer depend on the probe-order
573 in case of multiple competing signatures. In some setups the kernel allows
574 to mount a volume with just the old filesystem signature still in place.
575 This may damage the new filesystem and cause data-loss, just by mounting
576 it. Because volume_id can not decide which one the correct signature is,
577 the wrong signatures need to be removed manually from the volume, or the
578 volume needs to be reformatted, to enable filesystem detection and possible
583 Fix segfault if compiled without optimization and dbg() does not get
584 compiled out and uses variables which are not available.
588 Bugfixes. (And maybe new bugs. :))
590 The rule matching engine got converted from a rule list to a token
591 array which reduced the in-memory rules representation of a full
592 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
593 Limits like 5 ENV and ATTR matches, and one single instance for most
594 other keys per rule are gone.
596 The NAME assignment is no longer special cased. If later rules assign
597 a NAME value again, the former value will be overwritten. As usual
598 for most other keys, the NAME value can be protected by doing a final
599 assignment with NAME:="<value>".
601 All udev code now uses libudev, which is also exported. The library
602 is still under development, marked as experimental, and its interface
603 may change as long as the DeviceKit integration is not finished.
605 Many thanks to Alan Jenkins for his continuous help, and finding and
606 optimizing some of the computing expensive parts.
612 Kernel devices and device nodes are connected now by reverse indizes in
613 /sys and /dev. A device number retrieved by a stat() or similar, the
614 kernel device directory can be found by looking up:
615 /sys/dev/{block,char}/<maj>:<min>
616 and the device node of the same device by looking up:
617 /dev/{block,char}/<maj>:<min>
621 Fix recently introduced bug, which caused a compilation without large
622 file support, where vol_id does not recognize raid signatures at the end
625 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
626 Seems some kernel versions prevent the creation of the ieee-* links,
627 so people used the scsi-* link which disappeared now.
629 More libudev work. Almost all udevadm functionality comes from libudev
632 udevadm trigger has a new option --type, which allows to trigger events
633 for "devices", for "subsystems", or "failed" devices. The old option
634 --retry-failed" still works, but is no longer mentioned in the man page.
640 The udevadm info --device-id-of-file= output has changed to use
641 the obvious format. Possible current users should use the --export
642 option which is not affected.
644 The old udev commands symlinks to udevadm are not installed, if
645 these symlinks are used, a warning is printed.
651 Optical drive's media is no longer probed for raid signatures,
652 reading the end of the device causes some devices to malfunction.
653 Also the offset of the last session found is used now to probe
656 The volume_id library got a major version number update to 1,
657 some deprecated functions are removed.
659 A shared library "libudev" gets installed now to provide access
660 to udev device information. DeviceKit, the successor of HAL, will
661 need this library to access the udev database and search sysfs for
663 The library is currently in an experimental state, also the API is
664 expected to change, as long as the DeviceKit integration is not
669 We use ./configure now. See INSTALL for details. Current
672 "/usr" - prefix for man pages, include files
674 "" - the root filesystem, prefix for libs and binaries
678 "lib" - directory name for libraries, not a path name
679 multilib 64bit systems may use "lib64" instead of "lib"
681 compile-in verbose debug messages
683 disable all logging and compile-out all log strings
685 link against SELInux libraries, to set the expected context
688 In the default rules, the group "disk" gets permissions 0660 instead
689 of 0640. One small step closer to unify distro rules. Some day, all
690 distros hopefully end up with the same set of rules.
692 No symlinks to udevadm are installed anymore, if they are still needed,
693 they should be provided by the package.
699 Default udev rules, which are not supposed to be edited by the user, should
700 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
701 the udev package and will be replaced with an update. Udev will pick up rule
703 /lib/udev/rules.d/ - default installed rules
704 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
705 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
706 It does not matter in which directory a rule file lives, all files are sorted
709 To help creating /dev/root, we have now:
710 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
713 In case the current --device-id-of-file is already used, please switch to
714 the --export format version, it saves the output parsing and the old
715 format will be changed to use ':' as a separator, like the format in the
720 Fix cdrom_id to properly recognize blank media.
726 Tape drive id-data is queried from /dev/bsg/* instead of the tape
727 nodes. This avoids rewinding tapes on open().
733 The symlinks udevcontrol and udevtrigger are no longer installed by
736 The scsi_id program does not depend on sysfs anymore. It can speak
737 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
738 data, which should solve some old problems with tape devices, where
739 we better do not open all tape device nodes to identify the device.
745 The cdrom_id program is replaced by an advanced version, which can
746 detect most common device types, and also properties of the inserted
747 media. This is part of moving some basic functionality from HAL into
748 udev (and the kernel).
754 The last WAIT_FOR_SYSFS rule is removed from the default rules.
756 The symlinks to udevadm for the debugging tools: udevmonitor and
757 udevtest are no longer created.
759 The symlinks to the udevadm man page for the old tool names are
762 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
763 should be prefixed with '@' to indicate that the path is not a
774 Udevstart is removed from the tree, it did not get installed for
775 a long time now, and is long replaced by trigger and settle.
781 All udev tools are merged into a single binary called udevadm.
782 The old names of the tools are built-in commands in udevadm now.
783 Symlinks to udevadm, with the names of the old tools, provide
784 the same functionality as the standalone tools. There is also
785 only a single udevadm.8 man page left for all tools.
787 Tools like mkinitramfs should be checked, if they need to include
788 udevadm in the list of files.
798 The etc/udev/rules.d/ directory now contains a default set of basic
799 udev rules. This initial version is the result of a rules file merge
800 of Fedora and openSUSE. For these both distros only a few specific
801 rules are left in their own file, named after the distro. Rules which
802 are optionally installed, because they are only valid for a specific
803 architecture, or rules for subsystems which are not always used are
804 in etc/udev/packages/.
810 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
811 actions by dynamically created rules.
813 SYMLINK=="<value>" matches agains the entries in the list of
814 currently defined symlinks. The links are not created in the
815 filesystem at that point in time, but the values can be matched.
817 RUN{ignore_error}+="<program>" will ignore any exit code from the
818 program and not record as a failed event.
824 Final merge of patches/features from the Ubuntu package.
830 Control characters in filesystem label strings are no longer silenty
831 removed, but hex-encoded, to be able to uniquely identify the device
832 by its symlink in /dev/disk/by-label/.
833 If libvolume_id is used by mount(8), LABEL= will work as expected,
834 if slashes or other characters are used in the label string.
836 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
837 can be specified now. The TEST key accepts an optional mode mask
838 TEST{0100}=="<is executable file>".
840 Scsi_id now supports a mode without expecting scsi-specific sysfs
841 entries to allow the extraction of cciss-device persistent properties.
847 In the future, we may see uuid's which are just simple character
848 strings (see the DDF Raid Specification). For that reason vol_id now
849 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
850 the creation of symlinks, the *_SAFE values ensure, that no control
851 or whitespace characters are used in the filename.
853 Possible users of libvolume_id, please use the volume_id_get_* functions.
854 The public struct will go away in a future release of the library.
860 Removal of useless extras/eventrecorder.sh.
870 The directory multiplexer for dev.d/ and hotplug.d are finally removed
871 from the udev package.
877 Symlinks can have priorities now, the priority is assigned to the device
878 and specified with OPTIONS="link_priority=100". Devices with higher
879 priorities overwrite the symlinks of devices with lower priorities.
880 If the device that currently owns the link, goes away, the symlink
881 will be removed, and recreated, pointing to the next device with the
882 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
883 more reliable, if multiple devices contain the same metadata and overwrite
886 The dasd_id program is removed from the udev tree, and dasdinfo, with the
887 needed rules, are part of the s390-tools now.
889 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
890 we may get the scsi sysfs mess fixed some day, and this will only catch
891 the devices we are looking for.
893 USB serial numbers for storage devices have the target:lun now appended,
894 to make it possibble to distinguish broken multi-lun devices with all
895 the same SCSI identifiers.
897 Note: The extra "run_directory" which searches and executes stuff in
898 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
899 with the next release. Make sure, that you don't use it anymore, or
900 provides your own implementation of that inefficient stuff.
901 We are tired of reports about a "slow udev", because these directories
902 contain stuff, that runs with _every_ event, instead of using rules,
903 that run programs only for the matching events.
913 DRIVER== will match only for devices that actually have a real
914 driver. DRIVERS== must be used, if parent devices should be
915 included in the match.
917 Libvolume_id's "linux_raid" detection needed another fix.
925 Add additional check to volume_id detection of via_raid, cause
926 some company decided to put a matching pattern all over the empty
927 storage area of their music players.
931 Fix path_id for SAS devices.
935 The udev daemon can be started with --debug-trace now, which will
936 execute all events serialized to get a chance to catch a possible
937 action that crashes the box.
939 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
940 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
941 are excluded from the warning. Referencing parent attributes directly
942 may break when something in the kernel driver model changes. Udev will
943 just find the attribute by walking up the parent chain.
945 Udevtrigger now sorts the list of devices depending on the device
946 dependency, so a "usb" device is triggered after the parent "pci"
951 Revert persistent-storage ata-serial '_' '-' replacement.
957 Udevtrigger can now filter the list of devices to be triggered. Matches
958 for subsystems or sysfs attributes can be specified.
960 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
961 zero-sized files to avoid pointing to /sys and confuse broken tools which
962 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
965 The rules and scripts to create udev rules for persistent network
966 devices and optical drives are in the extras/rules_generator directory
967 now. If you use something similar, please consider replacing your own
968 version with this, to share the support effort. The rule_generator
969 installs its own rules into /etc/udev/rules.d.
971 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
972 the rule_generator depends on cdrom_id to be called in an earlier rule.
978 Renaming of some key names (the old names still work):
979 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
980 (The behavior of the key DRIVER will change soon in one of the next
981 releases, to match only the event device, please switch to DRIVERS
982 instead. If DRIVER is used, it will behave like DRIVERS, but an error
984 With the new key names, we have a more consistent and simpler scheme.
985 We can match the properties of the event device only, with: KERNEL,
986 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
987 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
988 longer mentioned in the man page and should be switched in the rule
991 ATTR{file}="value" can be used now, to write to a sysfs file of the
992 event device. Instead of:
993 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
995 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
997 All the PHYSDEV* keys are deprecated and will be removed from a
999 PHYDEVPATH - is the path of a parent device and should not be
1001 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1002 matched with SUBSYSTEMS==
1003 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1004 Newer kernels will have DRIVER in the environment,
1005 for older kernels udev puts in. Class device will
1006 no longer carry this property of a parent and
1007 DRIVERS== can be used to match such a parent value.
1008 Note that ENV{DRIVER} is only available for a few bus devices, where
1009 the driver is already bound at device event time. On coldplug, the
1010 events for a lot devices are already bound to a driver, and they will have
1011 that value set. But on hotplug, at the time the kernel creates the device,
1012 it can't know what driver may claim the device after that, therefore
1013 in most cases it will be empty.
1015 Failed events should now be re-triggered with:
1016 udevtrigger --retry-failed.
1017 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1018 files private to the udev tools. We may need to switch the current symlink
1019 target, cause some obviously broken tools try to scan all files in /dev
1020 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1021 million times. This takes ages on slow boxes.
1023 The udevinfo attribute walk (-a) now works with giving a device node
1024 name (-n) instead of a devpath (-p). The query now always works, also when
1025 no database file was created by udev.
1027 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1028 getpwnam() and getgrnam() now. One of the next releases will depend on
1029 fnmatch() and may use getopt_long().
1033 Bugfixes and small improvements.
1037 Fix path_id for recent kernels.
1043 Added support for swapping network interface names, by temporarily
1044 renaming the device and wait for the target name to become free.
1048 The built-in MODALIAS key and substitution is removed.
1052 The binary firmware helper is replaced by the usual simple
1053 shell script. Udevsend is removed from the tree.
1061 Some more keys require the correct use of '==' and '=' depending
1062 on the kind of operation beeing an assignment or a match. Rules
1063 with invalid operations are skipped and logged to syslog. Please
1064 test with udevtest if the parsing of your rules throws errors and
1065 fix possibly broken rules.
1069 Provide "udevsettle" to wait for all current udev events to finish.
1070 It also watches the current kernel netlink queue by comparing the
1071 even sequence number to make sure that there are no current pending
1072 events that have not already arrived in the daemon.
1076 Fix rule to skip persistent rules for removable IDE devices, which
1077 also skipped optical IDE drives.
1079 All *_id program are installed in /lib/udev/ by default now.
1081 No binary is stripped anymore as this should be done in the
1082 packaging process and not at build time.
1084 libvolume_id is provided as a shared library now and vol_id is
1085 linked against it. Also one of the next HAL versions will require
1086 this library, and the HAL build process will also require the
1087 header file to be installed. The copy of the same code in HAL will
1088 be removed to have only a single copy left on the system.
1092 Add persistent links for SCSI tapes. The rules file is renamed
1093 to 60-persistent-storage.rules.
1095 Create persistent path for usb devices. Can be used for all sorts
1096 of devices that can't be distinguished by other properties like
1097 multiple identical keyboards and mice connected to the same box.
1099 Provide "udevtrigger" program to request events on coldplug. The
1100 shell script is much too slow with thousends of devices.
1104 Fix persistent disk rules to exclude removable IDE drives.
1106 Warn if %e, $modalias or MODALIAS is used.
1110 Fix queue export, which wasn't correct for subsequent add/remove
1111 events for the same device.
1115 Fix cramfs detection on big endian.
1117 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1122 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1123 attributes were only checked at the parent device that matched the
1124 by BUS requested subsystem. Fix it to also look at the device we
1125 received the event for.
1127 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1132 Fix a bug where NAME="" would prevent RUN from beeing executed.
1134 RUN="/bin/program" does not longer automatically add the subsystem
1135 as the first parameter. This is from the days of /sbin/hotplug
1136 which is dead now and it's just confusing to need to add a space at
1137 the end of the program name to prevent this.
1138 If you use rules that need the subsystem as the first parameter,
1139 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1140 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1144 The udev man page has moved to udev(7) as it does not describe a command
1145 anymore. The programs udev, udevstart and udevsend are no longer installed
1146 by default and must be copied manually, if they should be installed or
1147 included in a package.
1149 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1150 the ignore rule was applied.
1152 More preparation for future sysfs changes. usb_id and scsi_id no longer
1153 depend on a magic order of devices in the /devices chain. Specific devices
1154 should be requested by their subsytem.
1156 This will always find the scsi parent device without depending on a specific
1158 dev = sysfs_device_get(devpath);
1159 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1161 The "device" link in the current sysfs layout will be automatically
1162 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1163 parent in the devpath. If a device is requested by it's symlink, like all
1164 class devices in the new sysfs layout will look like, it gets automatically
1165 resolved and substituted with the real devpath and not the symlink path.
1168 A similar logic must be applied to _all_ sysfs users, including
1169 scripts, that search along parent devices in sysfs. The explicit use of
1170 the "device" link must be avoided. With the future sysfs layout all
1171 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1172 back to the "class" or the "bus". The layout of the parent devices in
1173 /devices is not necessarily expected to be stable across kernel releases and
1174 searching for parents by their subsystem should make sysfs users tolerant
1175 for changed parent chains.
1179 Prepare udev to work with the experimental kernel patch, that moves
1180 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1182 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1183 moving the class devices to /sys/devices.
1185 Thanks again to Marco for help finding a hopefully nice compromise
1186 to make %b simpler and working again.
1190 Complete removal of libsysfs, replaced by simple helper functions
1191 which are much simpler and a bit faster. The udev daemon operatesentirely
1192 on event parameters and does not use sysfs for simple rules anymore.
1193 Please report any new bugs/problems, that may be caused by this big
1194 change. They will be fixed immediately.
1196 The enumeration format character '%e' is deprecated and will be
1197 removed sometimes from a future udev version. It never worked correctly
1198 outside of udevstart, so we can't use it with the new parallel
1199 coldplug. A simple enumeration is as useless as the devfs naming
1200 scheme, just get rid of both if you still use it.
1202 MODALIAS and $modalias is not needed and will be removed from one of
1203 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1204 the sysfs "modalias" value.
1206 Thanks a lot to Marco for all his help on finding and fixing bugs.
1210 Let scsi_id request libata drive serial numbers from page 0x80.
1212 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1213 added /dev/disk/by-name/* for device mapper device names.
1215 Removed %e from the man page. It never worked reliably outside
1216 of udevstart and udevstart is no longer recommended to use.
1220 Symlinks are now exported to the event environment. Hopefully it's no
1221 longer needed to run udevinfo from an event process, like it was
1222 mentioned on the hotplug list:
1223 UDEV [1134776873.702967] add@/block/sdb
1226 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1230 Fix a problem if udevsend is used as the hotplug handler and tries to use
1231 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1232 and this kind of problems will hopefully go away soon.
1236 All built-in logic to work around bad sysfs timing is removed with this
1237 version. The need to wait for sysfs files is almost fixed with a kernel
1238 version that doesn't work with this udev version anyway. Until we fix
1239 the timing of the "bus" link creation, the former integrated logic should
1240 be emulated by a rule placed before all other rules:
1241 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1243 The option "udev_db" does no longer exist. All udev state will be in
1244 /$udev_root/.udev/ now, there is no longer an option to set this
1246 If the init script or something else used this value, just depend on
1247 this hardcoded path. But remember _all_content_ of this directory is
1248 still private to udev and can change at any time.
1250 Default location for rule sripts and helper programs is now: /lib/udev/.
1251 Everything that is not useful on the commandline should go into this
1252 directory. Some of the helpers in the extras folder are installed there
1253 now. The rules need to be changed, to find the helpers there.
1255 Also /lib/udev/devices is recommended as a directory where packages or
1256 the user can place real device nodes, which get copied over to /dev at
1257 every boot. This should replace the various solutions with custom config
1260 Udevsend does no longer start the udev daemon. This must be done with
1261 the init script that prepares /dev on tmpfs and creates the initial nodes,
1262 before starting the daemon.
1266 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1269 The copy of klibc is removed. A systemwide installed version of klibc
1270 should be used to build a klibc udev now.
1274 NAME="" will not create any nodes, but execute RUN keys. To completely
1275 ignore an event the OPTION "ignore_device" should be used.
1277 After removal of the reorder queue, events with a TIMEOUT can be executed
1278 without any queuing now.
1282 Fixed bug in udevd, if inotify is not available. We depend on netlink
1283 uevents now, kernels without that event source will not work with that
1284 version of udev anymore.
1288 The rule parsing happens now in the daemon once at startup, all udev
1289 event processes inherit the already parsed rules from the daemon.
1290 It is shipped with SUSE10.0 and reduces heavily the system load at
1291 startup. The option to save precompiled rules and let the udev process
1292 pick the them up is removed, as it's no longer needed.
1294 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1295 device. Libsysfs is changed to "translate" the requested link into the
1296 real device path, as it would happen with the hotplug event. Otherwise
1297 device removal and the udev database will not work.
1299 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1302 A few improvements for vol_id, the filesytem probing code.
1306 Fix a stupid typo in extras/run_directory for "make install".
1308 scsi_id creates the temporary devnode now in /dev for usage with a
1309 non-writable /tmp directory.
1311 The uevent kernel socket buffer can carry app. 50.000 events now,
1312 let's see who can break this again. :)
1314 The upcoming kernel will have a new input driver core integration.
1315 Some class devices are now symlinks to the real device. libsysfs
1316 needs a fix for this to work correctly. Udevstart of older udev
1317 versions will _not_ create these devices!
1321 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1326 A bunch of mostly trivial bugfixes. From now on no node name or
1327 symlink name can contain any character than plain whitelisted ascii
1328 characters or validated utf8 byte-streams. This is needed for the
1329 /dev/disk/by-label/* links, because we import untrusted data and
1330 export it to the filesystem.
1334 More bugfixes. If udevd was started from the kernel, we don't
1335 have stdin/stdout/stderr, which broke the forked tools in some
1340 Bugfix. udevstart event ordering was broken for a long time.
1341 The new run_program() uncovered it, because /dev/null was not
1342 available while we try to run external programs.
1343 Now udevstart should create it before we run anything.
1347 Minor bugfixes and some distro rules updates. If you don't have the
1348 persistent disk rules in /dev/disk/by-*/* on your distro, just
1349 grab it from here. :)
1353 We can use socket communication now to pass events from udev to
1355 RUN+="socket:/org/freedesktop/hal/udev_event"
1356 will pass the whole udev event to the HAL daemon without the need
1357 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1361 Mostly bugfixes and see ChangeLog.
1363 The test for the existence of an environment value should be
1365 ENV{KEY}=="*" to ENV{KEY}=="?*"
1366 because "*" will not fail anymore, if the key does not exist or
1371 Bugfixes and a few tweaks described in the ChangeLog.
1375 Mostly a Bugfix release.
1377 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1378 timing with custom rules.
1382 We changed the internal rule storage format. Our large rule files took
1383 2 MB of RAM, with the change we are down to 99kB.
1385 If the device-node has been created with default name and no symlink or
1386 options are to remenber, it is not longer stored in the udevdb. HAL will
1387 need to be updated to work correctly with that change.
1389 To overrride optimization flags, OPTFLAGS may be used now.
1397 Major changes happened with this release. The goal is to take over the
1398 complete kernel-event handling and provide a more efficient way to dispatch
1399 kernel events. Replacing most of the current shell script logic and the
1400 kernel forked helper with a netlink-daemon and a rule-based event handling.
1402 o udevd listens to netlink events now. The first valid netlink event
1403 will make udevd ignore any message from udevsend that contains a
1404 SEQNUM, to avoid duplicate events. The forked events can be disabled
1406 echo "" > /proc/sys/kernel/hotplug
1407 For full support, the broken input-subsytem needs to be fixed, not to
1408 bypass the driver core.
1410 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1411 removed from udev itself and must be emulated by calling small
1412 helper binaries provided in the extras folder:
1413 make EXTRAS=extras/run_directory/
1414 will build udev_run_devd and udev_run_hotplugd, which can be called
1415 from a rule if needed:
1416 RUN+="/sbin/udev_run_hotplugd"
1417 The recommended way to handle this is to convert all the calls from
1418 the directories to explicit udev rules and get completely rid of the
1419 multiplexing. (To catch a ttyUSB event, you now no longer need to
1420 fork and exit 300 tty script instances you are not interested in, it
1421 is just one rule that matches exactly the device.)
1423 o udev handles now _all_ events not just events for class and block
1424 devices, this way it is possible to control the complete event
1425 behavior with udev rules. Especially useful for rules like:
1426 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1428 o As used in the modalias rule, udev supports now textual
1429 substitution placeholder along with the usual format chars. This
1430 needs to be documented, for now it's only visible in udev_rules_parse.c.
1432 o The rule keys support now more operations. This is documented in the
1433 man page. It is possible to add values to list-keys like the SYMLINK
1434 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1435 Also "final"-assignments are supported by using KEY:="value", which will
1436 prevent changing the key by any later rule.
1438 o kernel 2.6.12 has the "detached_state" attribute removed from
1439 sysfs, which was used to recognize sysfs population. We switched that
1440 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1441 Running this udev version on older kernels may cause a short delay for
1444 o To provide infrastructure for persistent device naming, the id programs:
1445 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1446 to export the probed data in environment key format:
1447 pim:~ # /sbin/ata_id --export /dev/hda
1448 ID_MODEL=HTS726060M9AT00
1449 ID_SERIAL=MRH401M4G6UM9B
1450 ID_REVISION=MH4OA6BA
1452 The following rules:
1453 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1454 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1457 kay@pim:~> tree /dev/disk
1460 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1461 | `-- IBM-Memory_Key -> ../../sda
1463 | |-- swap -> ../../hda1
1464 | |-- date -> ../../sda1
1465 | `-- home -> ../../hda3
1467 |-- 2E08712B0870F2E7 -> ../../hda3
1468 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1469 |-- E845-7A89 -> ../../sda1
1470 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1472 The IMPORT= operation will import these keys in the environment and make
1473 it available for later PROGRAM= and RUN= executed programs. The keys are
1474 also stored in the udevdb and can be queried from there with one of the
1477 o A few binaries are silently added to the repository, which can be used
1478 to replay kernel events from initramfs instead of using coldplug. udevd
1479 can be instructed now to queue-up events while the stored events from
1480 initramfs are filled into the udevd-queue. This code is still under
1481 development and there is no documentation now besides the code itself.
1482 The additional binaries get compiled, but are not installed by default.
1484 o There is also a temporary fix for a performance problem where too many
1485 events happen in parallel and every event needs to parse the rules.
1486 udev can now read precompiled rules stored on disk. This is likely to be
1487 replaced by a more elegant solution in a future udev version.
1491 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1492 Fix for libsysfs not to expect this file was added.
1496 All rules are applied now, but only the first matching rule with a NAME-key
1497 will be applied. All later rules with NAME-key are completely ignored. This
1498 way system supplied symlinks or permissions gets applied to user-defined
1502 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1503 to some rules, to keep the old behavior.
1505 The rules are read on "remove"-events too. That makes is possible to match
1506 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1507 instruct udev to ignore an event (OPTIONS="ignore_device").
1508 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1510 The new RUN-key supports rule-based execution of programs after device-node
1511 handling. This is meant as a general replacement for the dev.d/-directories
1512 to give fine grained control over the execution of programs.
1514 The %s{}-sysfs format char replacement values are searched at any of the
1515 devices in the device chain now, not only at the class-device.
1517 We support log priority levels now. The value udev_log in udev.conf is used
1518 to determine what is printed to syslog. This makes it possible to
1519 run a version with compiled-in debug messages in a production environment
1520 which is sometimes needed to find a bug.
1521 It is still possible to supress the inclusion of _any_ syslog usage with
1522 USE_LOG=false to create the smallest possible binaries if needed.
1523 The configured udev_log value can be overridden with the environment variable
1528 Possible use of a system-wide klibc:
1529 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1530 will link against an external klibc and our own version will be ignored.
1534 We support an unlimited count of symlinks now.
1536 If USE_STATIC=true is passed to a glibc build, we link statically and use
1537 a built-in userdb parser to resolve user and group names.
1539 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1540 we walk up the chain of physical devices to find a match.
1542 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1543 easy to skip certain attribute matches without composing rules with weird
1544 character class negations like:
1545 KERNEL="[!s][!c][!d]*"
1546 this can now be replaced with:
1548 The current simple '=' is still supported, and should work as it does today,
1549 but existing rules should be converted if possible, to be better readable.
1551 We have new ENV{}== key now, to match against a maximum of 5 environment
1554 udevstart is its own binary again, because we don't need co carry this araound
1555 with every forked event.