3 The default install location moved from /lib/udev to /usr/lib/udev,
4 to support systems without the / vs. /usr split. --libexecdir=
5 can still be configured to install things to /lib/udev.
7 The default install location of the 'udevadm' tool moved from 'sbin'
8 to /usr/bin. --bindir= can still be configured to install it in
9 /sbin. Some tools expect udevadm in 'sbin'. A symlink to udevadm
10 in /usr/bin needs to be manually created if needed.
12 Kernel modules are now loaded directly by linking udev to 'libkmod'.
13 The /sbin/modprobe tool is no longer executed by udev.
15 The /sbin/blkid tool is no longer executed from udev rules. Udev links
16 directly to libblkid now.
18 The 'udevadm control --reload-rules' option has been renamed to '--reload'.
19 It reloads the kernel module configuration.
21 The systemd socket files use PassCred=yes, which requires systemd
24 The udev build system only creates a .xz tarball now.
34 The udev daemon moved to /lib/udev/udevd. Non-systemd init systems
35 and non-dracut initramfs image generators need to change the init
36 scripts. Alternatively the udev build needs to move udevd back to
37 /sbin or create a symlink in /sbin, which is not done by default.
39 The path_id, usb_id, input_id tools are built-in commands now and
40 the stand-alone tools do not exist anymore. Static lists of file in
41 initramfs generators need to be updated. For testing, the commands
42 can still be executed standalone with 'udevadm test-builtin <cmd>'.
44 The fusectl filesystem is no longer mounted directly from udev.
45 Systemd systems will take care of mounting fusectl and configfs
46 now. Non-systemd systems need to ship their own rule if they
47 need these filesystems auto-mounted.
49 The long deprecated keys: SYSFS=, ID=, BUS= have been removed.
51 The support for 'udevadm trigger --type=failed, and the
52 RUN{fail_event_on_error} attribute was removed.
54 The udev control socket is now created in /run/udev/control
55 and no longer as an abstract namespace one.
57 The rules to create persistent network interface and cdrom link
58 rules automatically in /etc/udev/rules.d/ have been disabled by
59 default. Explicit configuration will be required for these use
60 cases, udev will no longer try to write any persistent system
61 configuration from a device hotplug path.
67 The udev-acl extra is no longer enabled by default now. To enable it,
68 --enable-udev_acl needs to be given at ./configure time. On systemd
69 systems, the udev-acl rules prevent it from running as the functionality
76 Udev now enables kernel media-presence polling if available. Part
77 of udisks optical drive tray-handling moved to cdrom_id: The tray
78 is locked as soon as a media is detected to enable the receiving
79 of media-eject-request events. Media-eject-request events will
82 Libudev enumerate is now able to enumerate a subtree of a given
85 The mobile-action-modeswitch modeswitch tool was deleted. The
86 functionality is provided by usb_modeswitch now.
92 The systemd service files require systemd version 28. The systemd
93 socket activation make it possible now to start 'udevd' and 'udevadm
98 Fix bug in control message handling, which can lead to a failing
99 udevadm control --exit. Thanks to Jürg Billeter for help tracking
106 We require at least Linux kernel 2.6.32 now. Some platforms might
107 require a later kernel that supports accept4() and similar, or
108 need to backport the trivial syscall wiring to the older kernels.
110 The hid2hci tool moved to the bluez package and was removed.
112 Many of the extras can be --enable/--disabled at ./configure
113 time. The --disable-extras option was removed. Some extras have
114 been disabled by default. The current options and their defaults
115 can be checked with './configure --help'.
121 Udev logs a warning now if /run is not writable at udevd
122 startup. It will still fall back to /dev/.udev, but this is
123 now considered a bug.
125 The running udev daemon can now cleanly shut down with:
126 udevadm control --exit
128 Udev in initramfs should clean the state of the udev database
129 with: udevadm info --cleanup-db which will remove all state left
130 behind from events/rules in initramfs. If initramfs uses
131 --cleanup-db and device-mapper/LVM, the rules in initramfs need
132 to add OPTIONS+="db_persist" for all dm devices. This will
133 prevent removal of the udev database for these devices.
135 Spawned programs by PROGRAM/IMPORT/RUN now have a hard timeout of
136 120 seconds per process. If that timeout is reached the spawned
137 process will be killed. The event timeout can be overwritten with
140 If systemd is used, udev gets now activated by netlink data.
141 Systemd will bind the netlink socket which will buffer all data.
142 If needed, such setup allows a seemless update of the udev daemon,
143 where no event can be lost during a udevd update/restart.
144 Packages need to make sure to: systemctl stop udev.socket udev.service
145 or 'mask' udev.service during the upgrade to prevent any unwanted
146 auto-spawning of udevd.
147 This version of udev conflicts with systemd version below 25. The
148 unchanged service files will not wirk correctly.
154 The udev runtime data moved from /dev/.udev/ to /run/udev/. The
155 /run mountpoint is supposed to be a tmpfs mounted during early boot,
156 available and writable to for all tools at any time during bootup,
157 it replaces /var/run/, which should become a symlink some day.
159 If /run does not exist, or is not writable, udev will fall back using
162 On systemd systems with initramfs and LVM used, packagers must
163 make sure, that the systemd and initramfs versions match. The initramfs
164 needs to create the /run mountpoint for udev to store the data, and
165 mount this tmpfs to /run in the rootfs, so the that the udev database
166 is preserved for the udev version started in the rootfs.
168 The command 'udevadm info --convert-db' is gone. The udev daemon
169 itself, at startup, converts any old database version if necessary.
171 The systemd services files have been reorganized. The udev control
172 socket is bound by systemd and passed to the started udev daemon.
173 The udev-settle.service is no longer active by default. Services which
174 can not handle hotplug setups properly need to actively pull it in, to
175 act like a barrier. Alternatively the settle service can be unconditionally
176 'systemctl'enabled, and act like a barrier for basic.target.
178 The fstab_import callout is no longer built or installed. Udev
179 should not be used to mount, does not watch changes to fstab, and
180 should not mirror fstab values in the udev database.
186 New and updated keymaps.
192 The udev database has changed, After installation of a new udev
193 version, 'udevadm info --convert-db' should be called, to let the new
194 udev/libudev version read the already stored data.
196 udevadm now supports quoting of property values, and prefixing of
198 $ udevadm info --export --export-prefix=MY_ --query=property -n sda
201 MY_DEVNAME='/dev/sda'
205 libudev now supports:
206 udev_device_get_is_initialized()
207 udev_enumerate_add_match_is_initialized()
208 to be able to skip devices the kernel has created , but udev has
211 libudev now supports:
212 udev_device_get_usec_since_initialized()
213 to retrieve the "age" of a udev device record.
215 GUdev supports a more generic GUdevEnumerator class, udev TAG
216 handling, device initialization and timestamp now.
218 The counterpart of /sys/dev/{char,block}/$major:$minor,
219 /dev/{char,block}/$major:$minor symlinks are now unconditionally
220 created, even when no rule files exist.
222 New and updated keymaps.
228 GUdev moved from /usr to /.
238 Persistent network naming rules are disabled inside of Qemu/KVM now.
240 New and updated keymaps.
242 Udev gets unconditionally enabled on systemd installations now. There
243 is no longer the need to to run 'systemctl enable udev.service'.
257 New and fixed keymaps.
259 Install systemd service files if applicable.
265 All distribution specific rules are removed from the udev source tree,
266 most of them are no longer needed. The Gentoo rules which allow to support
267 older kernel versions, which are not covered by the default rules anymore
268 has moved to rules/misc/30-kernel-compat.rules.
274 The option --debug-trace and the environemnt variable UDEVD_MAX_CHILDS=
275 was removed from udevd.
277 Udevd now checks the kernel commandline for the following variables:
278 udev.log-priority=<syslog priority>
279 udev.children-max=<maximum number of workers>
280 udev.exec-delay=<seconds to delay the execution of RUN=>
281 to help debuging coldplug setups where the loading of a kernel
282 module crashes the system.
284 The subdirectory in the source tree rules/packages has been renamed to
285 rules/arch, anc contains only architecture specific rules now.
295 Now the udev daemon itself, does on startup:
296 - copy the content of /lib/udev/devices to /dev
297 - create the standard symlinks like /dev/std{in,out,err},
298 /dev/core, /dev/fd, ...
299 - use static node information provided by kernel modules
300 and creates these nodes to allow module on-demand loading
301 - possibly apply permissions to all ststic nodes from udev
302 rules which are annotated to match a static node
304 The default mode for a device node is 0600 now to match the kernel
305 created devtmpfs defaults. If GROUP= is specified and no MODE= is
306 given the default will be 0660.
312 Udev now gradually starts to pass control over the primary device nodes
313 and their names to the kernel, and will in the end only manage the
314 permissions of the node, and possibly create additional symlinks.
315 As a first step NAME="" will be ignored, and NAME= setings with names
316 other than the kernel provided name will result in a logged warning.
317 Kernels that don't provide device names, or devtmpfs is not used, will
318 still work as they did before, but it is strongly recommended to use
319 only the same names for the primary device node as the recent kernel
320 provides for all devices.
324 Fix broken firmware loader search path.
330 "udevadm trigger" defaults to "change" events now instead of "add"
331 events. The "udev boot script" might need to add "--action=add" to
332 the trigger command if not already there, in case the initial coldplug
333 events are expected as "add" events.
335 The option "all_partitons" was removed from udev. This should not be
336 needed for usual hardware. Udev can not safely make assumptions
337 about non-existing partition major/minor numbers, and therefore no
338 longer provide this unreliable and unsafe option.
340 The option "ignore_remove" was removed from udev. With devtmpfs
341 udev passed control over device nodes to the kernel. This option
342 should not be needed, or can not work as advertised. Neither
343 udev nor the kernel will remove device nodes which are copied from
344 the /lib/udev/devices/ directory.
346 All "add|change" matches are replaced by "!remove" in the rules and
347 in the udev logic. All types of events will update possible symlinks
348 and permissions, only "remove" is handled special now.
350 The modem modeswitch extra was removed and the external usb_modeswitch
351 program should be used instead.
353 New and fixed keymaps.
363 Kernels with SYSFS_DEPRECATED=y are not supported since a while. Many users
364 depend on the current sysfs layout and the information not available in the
365 deprecated layout. All remaining support for the deprecated sysfs layout is
370 Fix for a possible endless loop in the new input_id program.
376 The option "ignore_device" does no longer exist. There is no way to
377 ignore an event, as libudev events can not be suppressed by rules.
378 It only prevented RUN keys from being executed, which results in an
379 inconsistent behavior in current setups.
381 BUS=, SYSFS{}=, ID= are long deprecated and should be SUBSYSTEM(S)=,
382 ATTR(S){}=, KERNEL(S)=. It will cause a warning once for every rule
385 The support for the deprecated IDE devices has been removed from the
386 default set of rules. Distros who still care about non-libata drivers
387 need to add the rules to the compat rules file.
389 The ID_CLASS property on input devices has been replaced by the more accurate
390 set of flags ID_INPUT_{KEYBOARD,KEY,MOUSE,TOUCHPAD,TABLET,JOYSTICK}. These are
391 determined by the new "input_id" prober now. Some devices, such as touchpads,
392 can have several classes. So if you previously had custom udev rules which e. g.
393 checked for ENV{ID_CLASS}=="kbd", you need to replace this with
394 ENV{ID_INPUT_KEYBOARD}=="?*".
400 To support DEVPATH strings larger than the maximum file name length, the
401 private udev database format has changed. If some software still reads the
402 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
403 Please do not port anything to the new format again, everything in /dev/.udev
404 is and always was private to udev, and may and will change any time without
407 Multiple devices claiming the same names in /dev are limited to symlinks
408 only now. Mixing identical symlink names and node names is not supported.
409 This reduces the amount of data in the database significantly.
411 NAME="%k" causes a warning now. It's is and always was completely superfluous.
412 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
415 Most NAME= instructions got removed. Kernel 2.6.31 supplies the needed names
416 if they are not the default. To support older kernels, the NAME= rules need to
417 be added to the compat rules file.
419 Symlinks to udevadm with the old command names are no longer resolved to
420 the udevadm commands.
422 The udev-acl tool got adopted to changes in ConsoleKit. Version 0.4.1 is
425 The option "last_rule" does no longer exist. Its use breaks too many
426 things which expect to be run from independent later rules, and is an idication
427 that something needs to be fixed properly instead.
429 The gudev API is no longer marked as experimental,
430 G_UDEV_API_IS_SUBJECT_TO_CHANGE is no longer needed. The gudev introspection
431 is enabled by default now. Various projects already depend on introspection
432 information to bind dynamic languages to the gudev interfaces.
438 The udevadm trigger "--retry-failed" option, which is replaced since quite
439 a while by "--type=failed" is removed.
441 The failed tracking was not working at all for a few releases. The RUN
442 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
443 default is not to track any failing RUN executions.
445 New keymaps, new modem, hid2hci updated.
449 Fix possible crash in udevd when worker processes are busy, rules are
450 changed at the same time, and workers get killed to reload the rules.
456 Properties set with ENV{.FOO}="bar" are marked private by starting the
457 name with a '.'. They will not be stored in the database, and not be
458 exported with the event.
460 Firmware files are looked up in:
461 /lib/firmware/updates/$(uname -r)
462 /lib/firmware/updates
463 /lib/firmware/$(uname -r)
467 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
468 ata_id, instead of scsi_id, is the default tool now for ATA devices.
474 The configure options have changed because another library needs to be
475 installed in a different location. Instead of exec_prefix and udev_prefix,
476 libdir, rootlibdir and libexecdir are used. The Details are explained in
479 Event processes now get re-used after they handled an event. This reduces
480 the number of forks and the pressure on the CPU significantly, because
481 cloned event processes no longer cause page faults in the main daemon.
482 After the events have settled, a few worker processes stay around for
483 future events, all others get cleaned up.
485 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
486 Also inotify support is mandatory now to run udev.
488 The format of the queue exported by the udev damon has changed. There is
489 no longer a /dev/.udev/queue/ directory. The current event queue can be
490 accessed with udevadm settle and libudedv.
492 Libudev does not have the unstable API header anymore. From now on,
493 incompatible changes will be handled by bumping the library major version.
495 To build udev from the git tree gtk-doc is needed now. The tarballs will
496 build without it and contain the pre-built documentation. An online copy
498 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
500 The tools from the udev-extras repository have been merged into the main
501 udev repository. Some of the extras have larger external dependencies, and
502 they can be disabled with the configure switch --disable-extras.
508 The program vol_id and the library libvolume_id are removed from the
509 repository. Libvolume_id is merged with libblkid from the util-linux-ng
510 package. Persistent disk links for label and uuid depend on the
511 util-linux-ng version (2.15) of blkid now. Older versions of blkid
512 can not be used with udev.
514 Libudev allows to subscribe to udev events. To prevent unwanted messages
515 to be delivered, and waking up the subscribing process, a filter can be
516 installed, to drop messages inside a kernel socket filter. The filters
517 match on the <subsytem>:<devtype> properties of the device.
518 This is part of the ongoing effort to replace HAL, and switch current
519 users over to directly use libudev.
520 Libudev is still marked as experimental, and its interface might
521 eventually change if needed, but no major changes of the currently exported
522 interface are expected anymore, and a first stable release should happen
525 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
526 is not supported since while and udevd will log an error message at
527 startup. It should still be able to boot-up, but advanced rules and system
528 services which depend on the information not available in the old sysfs
529 format will fail to work correctly.
531 DVB device naming is supplied by the kernel now. In case older kernels
532 need to be supported, the old shell script should be added to a compat
539 The processed udev events get send back to the netlink socket. Libudev
540 provides access to these events. This is work-in-progress, to replace
541 the DeviceKit daemon functionality directly with libudev. There are
542 upcoming kernel changes to allow non-root users to subcribe to these
549 "udevadm settle" now optionally accepts a range of events to wait for,
550 instead of waiting for "all" events.
556 The installed watch for block device metadata changes is now removed
557 during event hadling, because some (broken) tools may be called from udev
558 rules and (wrongly) open the device with write access. After the finished
559 event handling the watch is restored.
565 Device nodes can be watched for changes with inotify with OPTIONS="watch".
566 If closed after being opened for writing, a "change" uevent will occur.
567 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
573 The udevadm test command has no longer a --force option, nodes and symlinks
574 are always updated with a test run now.
576 The udevd daemon can be started with --resolve-names=never to avoid all user
577 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
578 lookup user and groups every time events are handled.
584 We are currently merging the Ubuntu rules in the udev default rules,
585 and get one step closer to provide a common Linux /dev setup, regarding
586 device names, symlinks, and default device permissions. On udev startup,
587 we now expect the following groups to be resolvable to their ids with
589 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
590 LDAP setups need to make sure, that these groups are always resolvable at
591 bootup, with only the rootfs mounted, and without network access available.
593 Some systems may need to add some new, currently not used groups, or need
594 to add some users to new groups, but the cost of this change is minimal,
595 compared to the pain the current, rather random, differences between the
596 various distributions cause for upstream projects and third-party vendors.
598 In general, "normal" users who log into a machine should never be a member
599 of any such group, but the device-access should be managed by dynamic ACLs,
600 which get added and removed for the specific users on login/logout and
601 session activity/inactivity. These groups are only provided for custom setups,
602 and mainly system services, to allow proper privilege separation.
603 A video-streaming daemon uid would be a member of "audio" and "video", to get
604 access to the sound and video devices, but no "normal" user should ever belong
605 to the "audio" group, because he could listen to the built-in microphone with
606 any ssh-session established from the other side of the world.
608 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
609 which do not depend on the kernel device name. As usual, unique
610 devices - only a single one per product connected, or a real
611 USB serial number in the device - are always found with the same
612 name in the by-id/ directory.
613 Completely identical devices may overwrite their names in by-id/
614 and can only be found reliably in the by-path/ directory. Devices
615 specified by by-path/ must not change their connection, like the
616 USB port number they are plugged in, to keep their name.
618 To support some advanced features, Linux 2.6.22 is the oldest supported
619 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
620 supported. Older kernels should still work, and devices nodes should be
621 reliably created, but some rules and libudev will not work correctly because
622 the old kernels do not provide the expected information or interfaces.
628 Fix for a possible segfault while swapping network interface names in udev
635 The group "video" is part of the default rules now.
639 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
640 block devices in some cases. No common distro uses this option anymore,
641 and we do not get enough testing for this and recent udev versions. If
642 this option is not needed to run some old distro with a new kernel,
643 it should be disabled in the kernel config.
645 Bugfix for the $links substitution variable, which may crash if no links
646 are created. This should not happen in usual setups because we always
647 create /dev/{block,char}/ links.
649 The strings of the parsed rules, which are kept in memory, no longer
650 contain duplicate entries, or duplicate tails of strings. This, and the
651 new rules parsing/matching code reduces the total in-memory size of
652 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
655 The export of DEVTYPE=disk/partition got removed from the default
656 rules. This value is available from the kernel. The pnp shell script
657 modprobe hack is removed from the default rules. ACPI devices have _proper_
658 modalias support and take care of the same functionality.
659 Installations which support old kernels, but install current default
660 udev rules may want to add that to the compat rules file.
662 Libvolume_id now always probes for all known filesystems, and does not
663 stop at the first match. Some filesystems are marked as "exclusive probe",
664 and if any other filesytem type matches at the same time, libvolume_id
665 will, by default, not return any probing result. This is intended to prevent
666 mis-detection with conflicting left-over signatures found from earlier
667 file system formats. That way, we no longer depend on the probe-order
668 in case of multiple competing signatures. In some setups the kernel allows
669 to mount a volume with just the old filesystem signature still in place.
670 This may damage the new filesystem and cause data-loss, just by mounting
671 it. Because volume_id can not decide which one the correct signature is,
672 the wrong signatures need to be removed manually from the volume, or the
673 volume needs to be reformatted, to enable filesystem detection and possible
678 Fix segfault if compiled without optimization and dbg() does not get
679 compiled out and uses variables which are not available.
683 Bugfixes. (And maybe new bugs. :))
685 The rule matching engine got converted from a rule list to a token
686 array which reduced the in-memory rules representation of a full
687 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
688 Limits like 5 ENV and ATTR matches, and one single instance for most
689 other keys per rule are gone.
691 The NAME assignment is no longer special cased. If later rules assign
692 a NAME value again, the former value will be overwritten. As usual
693 for most other keys, the NAME value can be protected by doing a final
694 assignment with NAME:="<value>".
696 All udev code now uses libudev, which is also exported. The library
697 is still under development, marked as experimental, and its interface
698 may change as long as the DeviceKit integration is not finished.
700 Many thanks to Alan Jenkins for his continuous help, and finding and
701 optimizing some of the computing expensive parts.
707 Kernel devices and device nodes are connected now by reverse indizes in
708 /sys and /dev. A device number retrieved by a stat() or similar, the
709 kernel device directory can be found by looking up:
710 /sys/dev/{block,char}/<maj>:<min>
711 and the device node of the same device by looking up:
712 /dev/{block,char}/<maj>:<min>
716 Fix recently introduced bug, which caused a compilation without large
717 file support, where vol_id does not recognize raid signatures at the end
720 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
721 Seems some kernel versions prevent the creation of the ieee-* links,
722 so people used the scsi-* link which disappeared now.
724 More libudev work. Almost all udevadm functionality comes from libudev
727 udevadm trigger has a new option --type, which allows to trigger events
728 for "devices", for "subsystems", or "failed" devices. The old option
729 --retry-failed" still works, but is no longer mentioned in the man page.
735 The udevadm info --device-id-of-file= output has changed to use
736 the obvious format. Possible current users should use the --export
737 option which is not affected.
739 The old udev commands symlinks to udevadm are not installed, if
740 these symlinks are used, a warning is printed.
746 Optical drive's media is no longer probed for raid signatures,
747 reading the end of the device causes some devices to malfunction.
748 Also the offset of the last session found is used now to probe
751 The volume_id library got a major version number update to 1,
752 some deprecated functions are removed.
754 A shared library "libudev" gets installed now to provide access
755 to udev device information. DeviceKit, the successor of HAL, will
756 need this library to access the udev database and search sysfs for
758 The library is currently in an experimental state, also the API is
759 expected to change, as long as the DeviceKit integration is not
764 We use ./configure now. See INSTALL for details. Current
767 "/usr" - prefix for man pages, include files
769 "" - the root filesystem, prefix for libs and binaries
773 "lib" - directory name for libraries, not a path name
774 multilib 64bit systems may use "lib64" instead of "lib"
776 compile-in verbose debug messages
778 disable all logging and compile-out all log strings
780 link against SELInux libraries, to set the expected context
783 In the default rules, the group "disk" gets permissions 0660 instead
784 of 0640. One small step closer to unify distro rules. Some day, all
785 distros hopefully end up with the same set of rules.
787 No symlinks to udevadm are installed anymore, if they are still needed,
788 they should be provided by the package.
794 Default udev rules, which are not supposed to be edited by the user, should
795 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
796 the udev package and will be replaced with an update. Udev will pick up rule
798 /lib/udev/rules.d/ - default installed rules
799 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
800 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
801 It does not matter in which directory a rule file lives, all files are sorted
804 To help creating /dev/root, we have now:
805 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
808 In case the current --device-id-of-file is already used, please switch to
809 the --export format version, it saves the output parsing and the old
810 format will be changed to use ':' as a separator, like the format in the
815 Fix cdrom_id to properly recognize blank media.
821 Tape drive id-data is queried from /dev/bsg/* instead of the tape
822 nodes. This avoids rewinding tapes on open().
828 The symlinks udevcontrol and udevtrigger are no longer installed by
831 The scsi_id program does not depend on sysfs anymore. It can speak
832 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
833 data, which should solve some old problems with tape devices, where
834 we better do not open all tape device nodes to identify the device.
840 The cdrom_id program is replaced by an advanced version, which can
841 detect most common device types, and also properties of the inserted
842 media. This is part of moving some basic functionality from HAL into
843 udev (and the kernel).
849 The last WAIT_FOR_SYSFS rule is removed from the default rules.
851 The symlinks to udevadm for the debugging tools: udevmonitor and
852 udevtest are no longer created.
854 The symlinks to the udevadm man page for the old tool names are
857 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
858 should be prefixed with '@' to indicate that the path is not a
869 Udevstart is removed from the tree, it did not get installed for
870 a long time now, and is long replaced by trigger and settle.
876 All udev tools are merged into a single binary called udevadm.
877 The old names of the tools are built-in commands in udevadm now.
878 Symlinks to udevadm, with the names of the old tools, provide
879 the same functionality as the standalone tools. There is also
880 only a single udevadm.8 man page left for all tools.
882 Tools like mkinitramfs should be checked, if they need to include
883 udevadm in the list of files.
893 The etc/udev/rules.d/ directory now contains a default set of basic
894 udev rules. This initial version is the result of a rules file merge
895 of Fedora and openSUSE. For these both distros only a few specific
896 rules are left in their own file, named after the distro. Rules which
897 are optionally installed, because they are only valid for a specific
898 architecture, or rules for subsystems which are not always used are
899 in etc/udev/packages/.
905 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
906 actions by dynamically created rules.
908 SYMLINK=="<value>" matches agains the entries in the list of
909 currently defined symlinks. The links are not created in the
910 filesystem at that point in time, but the values can be matched.
912 RUN{ignore_error}+="<program>" will ignore any exit code from the
913 program and not record as a failed event.
919 Final merge of patches/features from the Ubuntu package.
925 Control characters in filesystem label strings are no longer silenty
926 removed, but hex-encoded, to be able to uniquely identify the device
927 by its symlink in /dev/disk/by-label/.
928 If libvolume_id is used by mount(8), LABEL= will work as expected,
929 if slashes or other characters are used in the label string.
931 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
932 can be specified now. The TEST key accepts an optional mode mask
933 TEST{0100}=="<is executable file>".
935 Scsi_id now supports a mode without expecting scsi-specific sysfs
936 entries to allow the extraction of cciss-device persistent properties.
942 In the future, we may see uuid's which are just simple character
943 strings (see the DDF Raid Specification). For that reason vol_id now
944 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
945 the creation of symlinks, the *_SAFE values ensure, that no control
946 or whitespace characters are used in the filename.
948 Possible users of libvolume_id, please use the volume_id_get_* functions.
949 The public struct will go away in a future release of the library.
955 Removal of useless extras/eventrecorder.sh.
965 The directory multiplexer for dev.d/ and hotplug.d are finally removed
966 from the udev package.
972 Symlinks can have priorities now, the priority is assigned to the device
973 and specified with OPTIONS="link_priority=100". Devices with higher
974 priorities overwrite the symlinks of devices with lower priorities.
975 If the device that currently owns the link, goes away, the symlink
976 will be removed, and recreated, pointing to the next device with the
977 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
978 more reliable, if multiple devices contain the same metadata and overwrite
981 The dasd_id program is removed from the udev tree, and dasdinfo, with the
982 needed rules, are part of the s390-tools now.
984 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
985 we may get the scsi sysfs mess fixed some day, and this will only catch
986 the devices we are looking for.
988 USB serial numbers for storage devices have the target:lun now appended,
989 to make it possibble to distinguish broken multi-lun devices with all
990 the same SCSI identifiers.
992 Note: The extra "run_directory" which searches and executes stuff in
993 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
994 with the next release. Make sure, that you don't use it anymore, or
995 provides your own implementation of that inefficient stuff.
996 We are tired of reports about a "slow udev", because these directories
997 contain stuff, that runs with _every_ event, instead of using rules,
998 that run programs only for the matching events.
1008 DRIVER== will match only for devices that actually have a real
1009 driver. DRIVERS== must be used, if parent devices should be
1010 included in the match.
1012 Libvolume_id's "linux_raid" detection needed another fix.
1020 Add additional check to volume_id detection of via_raid, cause
1021 some company decided to put a matching pattern all over the empty
1022 storage area of their music players.
1026 Fix path_id for SAS devices.
1030 The udev daemon can be started with --debug-trace now, which will
1031 execute all events serialized to get a chance to catch a possible
1032 action that crashes the box.
1034 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
1035 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
1036 are excluded from the warning. Referencing parent attributes directly
1037 may break when something in the kernel driver model changes. Udev will
1038 just find the attribute by walking up the parent chain.
1040 Udevtrigger now sorts the list of devices depending on the device
1041 dependency, so a "usb" device is triggered after the parent "pci"
1046 Revert persistent-storage ata-serial '_' '-' replacement.
1052 Udevtrigger can now filter the list of devices to be triggered. Matches
1053 for subsystems or sysfs attributes can be specified.
1055 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
1056 zero-sized files to avoid pointing to /sys and confuse broken tools which
1057 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
1060 The rules and scripts to create udev rules for persistent network
1061 devices and optical drives are in the extras/rules_generator directory
1062 now. If you use something similar, please consider replacing your own
1063 version with this, to share the support effort. The rule_generator
1064 installs its own rules into /etc/udev/rules.d.
1066 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
1067 the rule_generator depends on cdrom_id to be called in an earlier rule.
1073 Renaming of some key names (the old names still work):
1074 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
1075 (The behavior of the key DRIVER will change soon in one of the next
1076 releases, to match only the event device, please switch to DRIVERS
1077 instead. If DRIVER is used, it will behave like DRIVERS, but an error
1079 With the new key names, we have a more consistent and simpler scheme.
1080 We can match the properties of the event device only, with: KERNEL,
1081 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
1082 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
1083 longer mentioned in the man page and should be switched in the rule
1086 ATTR{file}="value" can be used now, to write to a sysfs file of the
1087 event device. Instead of:
1088 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
1090 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
1092 All the PHYSDEV* keys are deprecated and will be removed from a
1094 PHYDEVPATH - is the path of a parent device and should not be
1096 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
1097 matched with SUBSYSTEMS==
1098 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
1099 Newer kernels will have DRIVER in the environment,
1100 for older kernels udev puts in. Class device will
1101 no longer carry this property of a parent and
1102 DRIVERS== can be used to match such a parent value.
1103 Note that ENV{DRIVER} is only available for a few bus devices, where
1104 the driver is already bound at device event time. On coldplug, the
1105 events for a lot devices are already bound to a driver, and they will have
1106 that value set. But on hotplug, at the time the kernel creates the device,
1107 it can't know what driver may claim the device after that, therefore
1108 in most cases it will be empty.
1110 Failed events should now be re-triggered with:
1111 udevtrigger --retry-failed.
1112 Please switch to this command, so we keep the details of the /dev/.udev/failed/
1113 files private to the udev tools. We may need to switch the current symlink
1114 target, cause some obviously broken tools try to scan all files in /dev
1115 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
1116 million times. This takes ages on slow boxes.
1118 The udevinfo attribute walk (-a) now works with giving a device node
1119 name (-n) instead of a devpath (-p). The query now always works, also when
1120 no database file was created by udev.
1122 The built-in /etc/passwd /etc/group parser is removed, we always depend on
1123 getpwnam() and getgrnam() now. One of the next releases will depend on
1124 fnmatch() and may use getopt_long().
1128 Bugfixes and small improvements.
1132 Fix path_id for recent kernels.
1138 Added support for swapping network interface names, by temporarily
1139 renaming the device and wait for the target name to become free.
1143 The built-in MODALIAS key and substitution is removed.
1147 The binary firmware helper is replaced by the usual simple
1148 shell script. Udevsend is removed from the tree.
1156 Some more keys require the correct use of '==' and '=' depending
1157 on the kind of operation beeing an assignment or a match. Rules
1158 with invalid operations are skipped and logged to syslog. Please
1159 test with udevtest if the parsing of your rules throws errors and
1160 fix possibly broken rules.
1164 Provide "udevsettle" to wait for all current udev events to finish.
1165 It also watches the current kernel netlink queue by comparing the
1166 even sequence number to make sure that there are no current pending
1167 events that have not already arrived in the daemon.
1171 Fix rule to skip persistent rules for removable IDE devices, which
1172 also skipped optical IDE drives.
1174 All *_id program are installed in /lib/udev/ by default now.
1176 No binary is stripped anymore as this should be done in the
1177 packaging process and not at build time.
1179 libvolume_id is provided as a shared library now and vol_id is
1180 linked against it. Also one of the next HAL versions will require
1181 this library, and the HAL build process will also require the
1182 header file to be installed. The copy of the same code in HAL will
1183 be removed to have only a single copy left on the system.
1187 Add persistent links for SCSI tapes. The rules file is renamed
1188 to 60-persistent-storage.rules.
1190 Create persistent path for usb devices. Can be used for all sorts
1191 of devices that can't be distinguished by other properties like
1192 multiple identical keyboards and mice connected to the same box.
1194 Provide "udevtrigger" program to request events on coldplug. The
1195 shell script is much too slow with thousends of devices.
1199 Fix persistent disk rules to exclude removable IDE drives.
1201 Warn if %e, $modalias or MODALIAS is used.
1205 Fix queue export, which wasn't correct for subsequent add/remove
1206 events for the same device.
1210 Fix cramfs detection on big endian.
1212 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
1217 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
1218 attributes were only checked at the parent device that matched the
1219 by BUS requested subsystem. Fix it to also look at the device we
1220 received the event for.
1222 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
1227 Fix a bug where NAME="" would prevent RUN from beeing executed.
1229 RUN="/bin/program" does not longer automatically add the subsystem
1230 as the first parameter. This is from the days of /sbin/hotplug
1231 which is dead now and it's just confusing to need to add a space at
1232 the end of the program name to prevent this.
1233 If you use rules that need the subsystem as the first parameter,
1234 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
1235 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
1239 The udev man page has moved to udev(7) as it does not describe a command
1240 anymore. The programs udev, udevstart and udevsend are no longer installed
1241 by default and must be copied manually, if they should be installed or
1242 included in a package.
1244 Fix a bug where "ignore_device" could run earlier collected RUN keys before
1245 the ignore rule was applied.
1247 More preparation for future sysfs changes. usb_id and scsi_id no longer
1248 depend on a magic order of devices in the /devices chain. Specific devices
1249 should be requested by their subsytem.
1251 This will always find the scsi parent device without depending on a specific
1253 dev = sysfs_device_get(devpath);
1254 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
1256 The "device" link in the current sysfs layout will be automatically
1257 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
1258 parent in the devpath. If a device is requested by it's symlink, like all
1259 class devices in the new sysfs layout will look like, it gets automatically
1260 resolved and substituted with the real devpath and not the symlink path.
1263 A similar logic must be applied to _all_ sysfs users, including
1264 scripts, that search along parent devices in sysfs. The explicit use of
1265 the "device" link must be avoided. With the future sysfs layout all
1266 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
1267 back to the "class" or the "bus". The layout of the parent devices in
1268 /devices is not necessarily expected to be stable across kernel releases and
1269 searching for parents by their subsystem should make sysfs users tolerant
1270 for changed parent chains.
1274 Prepare udev to work with the experimental kernel patch, that moves
1275 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
1277 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
1278 moving the class devices to /sys/devices.
1280 Thanks again to Marco for help finding a hopefully nice compromise
1281 to make %b simpler and working again.
1285 Complete removal of libsysfs, replaced by simple helper functions
1286 which are much simpler and a bit faster. The udev daemon operatesentirely
1287 on event parameters and does not use sysfs for simple rules anymore.
1288 Please report any new bugs/problems, that may be caused by this big
1289 change. They will be fixed immediately.
1291 The enumeration format character '%e' is deprecated and will be
1292 removed sometimes from a future udev version. It never worked correctly
1293 outside of udevstart, so we can't use it with the new parallel
1294 coldplug. A simple enumeration is as useless as the devfs naming
1295 scheme, just get rid of both if you still use it.
1297 MODALIAS and $modalias is not needed and will be removed from one of
1298 the next udev versions, replace it in all rules with ENV{MODALIAS} or
1299 the sysfs "modalias" value.
1301 Thanks a lot to Marco for all his help on finding and fixing bugs.
1305 Let scsi_id request libata drive serial numbers from page 0x80.
1307 Renamed etc/udev/persistent.rules to persistent-disk.rules and
1308 added /dev/disk/by-name/* for device mapper device names.
1310 Removed %e from the man page. It never worked reliably outside
1311 of udevstart and udevstart is no longer recommended to use.
1315 Symlinks are now exported to the event environment. Hopefully it's no
1316 longer needed to run udevinfo from an event process, like it was
1317 mentioned on the hotplug list:
1318 UDEV [1134776873.702967] add@/block/sdb
1321 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
1325 Fix a problem if udevsend is used as the hotplug handler and tries to use
1326 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
1327 and this kind of problems will hopefully go away soon.
1331 All built-in logic to work around bad sysfs timing is removed with this
1332 version. The need to wait for sysfs files is almost fixed with a kernel
1333 version that doesn't work with this udev version anyway. Until we fix
1334 the timing of the "bus" link creation, the former integrated logic should
1335 be emulated by a rule placed before all other rules:
1336 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
1338 The option "udev_db" does no longer exist. All udev state will be in
1339 /$udev_root/.udev/ now, there is no longer an option to set this
1341 If the init script or something else used this value, just depend on
1342 this hardcoded path. But remember _all_content_ of this directory is
1343 still private to udev and can change at any time.
1345 Default location for rule sripts and helper programs is now: /lib/udev/.
1346 Everything that is not useful on the commandline should go into this
1347 directory. Some of the helpers in the extras folder are installed there
1348 now. The rules need to be changed, to find the helpers there.
1350 Also /lib/udev/devices is recommended as a directory where packages or
1351 the user can place real device nodes, which get copied over to /dev at
1352 every boot. This should replace the various solutions with custom config
1355 Udevsend does no longer start the udev daemon. This must be done with
1356 the init script that prepares /dev on tmpfs and creates the initial nodes,
1357 before starting the daemon.
1361 Silent a too verbose error logging for the old hotplug.d/ dev.d/
1364 The copy of klibc is removed. A systemwide installed version of klibc
1365 should be used to build a klibc udev now.
1369 NAME="" will not create any nodes, but execute RUN keys. To completely
1370 ignore an event the OPTION "ignore_device" should be used.
1372 After removal of the reorder queue, events with a TIMEOUT can be executed
1373 without any queuing now.
1377 Fixed bug in udevd, if inotify is not available. We depend on netlink
1378 uevents now, kernels without that event source will not work with that
1379 version of udev anymore.
1383 The rule parsing happens now in the daemon once at startup, all udev
1384 event processes inherit the already parsed rules from the daemon.
1385 It is shipped with SUSE10.0 and reduces heavily the system load at
1386 startup. The option to save precompiled rules and let the udev process
1387 pick the them up is removed, as it's no longer needed.
1389 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
1390 device. Libsysfs is changed to "translate" the requested link into the
1391 real device path, as it would happen with the hotplug event. Otherwise
1392 device removal and the udev database will not work.
1394 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
1397 A few improvements for vol_id, the filesytem probing code.
1401 Fix a stupid typo in extras/run_directory for "make install".
1403 scsi_id creates the temporary devnode now in /dev for usage with a
1404 non-writable /tmp directory.
1406 The uevent kernel socket buffer can carry app. 50.000 events now,
1407 let's see who can break this again. :)
1409 The upcoming kernel will have a new input driver core integration.
1410 Some class devices are now symlinks to the real device. libsysfs
1411 needs a fix for this to work correctly. Udevstart of older udev
1412 versions will _not_ create these devices!
1416 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1421 A bunch of mostly trivial bugfixes. From now on no node name or
1422 symlink name can contain any character than plain whitelisted ascii
1423 characters or validated utf8 byte-streams. This is needed for the
1424 /dev/disk/by-label/* links, because we import untrusted data and
1425 export it to the filesystem.
1429 More bugfixes. If udevd was started from the kernel, we don't
1430 have stdin/stdout/stderr, which broke the forked tools in some
1435 Bugfix. udevstart event ordering was broken for a long time.
1436 The new run_program() uncovered it, because /dev/null was not
1437 available while we try to run external programs.
1438 Now udevstart should create it before we run anything.
1442 Minor bugfixes and some distro rules updates. If you don't have the
1443 persistent disk rules in /dev/disk/by-*/* on your distro, just
1444 grab it from here. :)
1448 We can use socket communication now to pass events from udev to
1450 RUN+="socket:/org/freedesktop/hal/udev_event"
1451 will pass the whole udev event to the HAL daemon without the need
1452 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1456 Mostly bugfixes and see ChangeLog.
1458 The test for the existence of an environment value should be
1460 ENV{KEY}=="*" to ENV{KEY}=="?*"
1461 because "*" will not fail anymore, if the key does not exist or
1466 Bugfixes and a few tweaks described in the ChangeLog.
1470 Mostly a Bugfix release.
1472 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1473 timing with custom rules.
1477 We changed the internal rule storage format. Our large rule files took
1478 2 MB of RAM, with the change we are down to 99kB.
1480 If the device-node has been created with default name and no symlink or
1481 options are to remenber, it is not longer stored in the udevdb. HAL will
1482 need to be updated to work correctly with that change.
1484 To overrride optimization flags, OPTFLAGS may be used now.
1492 Major changes happened with this release. The goal is to take over the
1493 complete kernel-event handling and provide a more efficient way to dispatch
1494 kernel events. Replacing most of the current shell script logic and the
1495 kernel forked helper with a netlink-daemon and a rule-based event handling.
1497 o udevd listens to netlink events now. The first valid netlink event
1498 will make udevd ignore any message from udevsend that contains a
1499 SEQNUM, to avoid duplicate events. The forked events can be disabled
1501 echo "" > /proc/sys/kernel/hotplug
1502 For full support, the broken input-subsytem needs to be fixed, not to
1503 bypass the driver core.
1505 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1506 removed from udev itself and must be emulated by calling small
1507 helper binaries provided in the extras folder:
1508 make EXTRAS=extras/run_directory/
1509 will build udev_run_devd and udev_run_hotplugd, which can be called
1510 from a rule if needed:
1511 RUN+="/sbin/udev_run_hotplugd"
1512 The recommended way to handle this is to convert all the calls from
1513 the directories to explicit udev rules and get completely rid of the
1514 multiplexing. (To catch a ttyUSB event, you now no longer need to
1515 fork and exit 300 tty script instances you are not interested in, it
1516 is just one rule that matches exactly the device.)
1518 o udev handles now _all_ events not just events for class and block
1519 devices, this way it is possible to control the complete event
1520 behavior with udev rules. Especially useful for rules like:
1521 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1523 o As used in the modalias rule, udev supports now textual
1524 substitution placeholder along with the usual format chars. This
1525 needs to be documented, for now it's only visible in udev_rules_parse.c.
1527 o The rule keys support now more operations. This is documented in the
1528 man page. It is possible to add values to list-keys like the SYMLINK
1529 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1530 Also "final"-assignments are supported by using KEY:="value", which will
1531 prevent changing the key by any later rule.
1533 o kernel 2.6.12 has the "detached_state" attribute removed from
1534 sysfs, which was used to recognize sysfs population. We switched that
1535 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1536 Running this udev version on older kernels may cause a short delay for
1539 o To provide infrastructure for persistent device naming, the id programs:
1540 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1541 to export the probed data in environment key format:
1542 pim:~ # /sbin/ata_id --export /dev/hda
1543 ID_MODEL=HTS726060M9AT00
1544 ID_SERIAL=MRH401M4G6UM9B
1545 ID_REVISION=MH4OA6BA
1547 The following rules:
1548 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1549 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1552 kay@pim:~> tree /dev/disk
1555 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1556 | `-- IBM-Memory_Key -> ../../sda
1558 | |-- swap -> ../../hda1
1559 | |-- date -> ../../sda1
1560 | `-- home -> ../../hda3
1562 |-- 2E08712B0870F2E7 -> ../../hda3
1563 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1564 |-- E845-7A89 -> ../../sda1
1565 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1567 The IMPORT= operation will import these keys in the environment and make
1568 it available for later PROGRAM= and RUN= executed programs. The keys are
1569 also stored in the udevdb and can be queried from there with one of the
1572 o A few binaries are silently added to the repository, which can be used
1573 to replay kernel events from initramfs instead of using coldplug. udevd
1574 can be instructed now to queue-up events while the stored events from
1575 initramfs are filled into the udevd-queue. This code is still under
1576 development and there is no documentation now besides the code itself.
1577 The additional binaries get compiled, but are not installed by default.
1579 o There is also a temporary fix for a performance problem where too many
1580 events happen in parallel and every event needs to parse the rules.
1581 udev can now read precompiled rules stored on disk. This is likely to be
1582 replaced by a more elegant solution in a future udev version.
1586 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1587 Fix for libsysfs not to expect this file was added.
1591 All rules are applied now, but only the first matching rule with a NAME-key
1592 will be applied. All later rules with NAME-key are completely ignored. This
1593 way system supplied symlinks or permissions gets applied to user-defined
1597 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1598 to some rules, to keep the old behavior.
1600 The rules are read on "remove"-events too. That makes is possible to match
1601 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1602 instruct udev to ignore an event (OPTIONS="ignore_device").
1603 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1605 The new RUN-key supports rule-based execution of programs after device-node
1606 handling. This is meant as a general replacement for the dev.d/-directories
1607 to give fine grained control over the execution of programs.
1609 The %s{}-sysfs format char replacement values are searched at any of the
1610 devices in the device chain now, not only at the class-device.
1612 We support log priority levels now. The value udev_log in udev.conf is used
1613 to determine what is printed to syslog. This makes it possible to
1614 run a version with compiled-in debug messages in a production environment
1615 which is sometimes needed to find a bug.
1616 It is still possible to supress the inclusion of _any_ syslog usage with
1617 USE_LOG=false to create the smallest possible binaries if needed.
1618 The configured udev_log value can be overridden with the environment variable
1623 Possible use of a system-wide klibc:
1624 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1625 will link against an external klibc and our own version will be ignored.
1629 We support an unlimited count of symlinks now.
1631 If USE_STATIC=true is passed to a glibc build, we link statically and use
1632 a built-in userdb parser to resolve user and group names.
1634 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1635 we walk up the chain of physical devices to find a match.
1637 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1638 easy to skip certain attribute matches without composing rules with weird
1639 character class negations like:
1640 KERNEL="[!s][!c][!d]*"
1641 this can now be replaced with:
1643 The current simple '=' is still supported, and should work as it does today,
1644 but existing rules should be converted if possible, to be better readable.
1646 We have new ENV{}== key now, to match against a maximum of 5 environment
1649 udevstart is its own binary again, because we don't need co carry this araound
1650 with every forked event.
~ianmdlvl / elogind.git / blob