5 Event processes now get re-used after they handled an event. This reduces
6 pressure on the CPU significantly because cloned event processes no longer
7 cause page faults in the main daemon. After the events have settled, the
8 no longer needed worker processes get killed.
10 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
11 Also inotify support is required now to run udev.
13 The format of the queue exported by the udev damon has changed. There is
14 no longer a /dev/.udev/queue/ directory. The current event queue can be
15 accessed with udevadm settle and libudedv.
21 The program vol_id and the library libvolume_id are removed from the
22 repository. Libvolume_id is merged with libblkid from the util-linux-ng
23 package. Persistent disk links for label and uuid depend on the
24 util-linux-ng version (2.15) of blkid now. Older versions of blkid
25 can not be used with udev.
27 Libudev allows to subscribe to udev events. To prevent unwanted messages
28 to be delivered, and waking up the subscribing process, a filter can be
29 installed, to drop messages inside a kernel socket filter. The filters
30 match on the <subsytem>:<devtype> properties of the device.
31 This is part of the ongoing effort to replace HAL, and switch current
32 users over to directly use libudev.
33 Libudev is still marked as experimental, and its interface might
34 eventually change if needed, but no major changes of the currently exported
35 interface are expected anymore, and a first stable release should happen
38 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
39 is not supported since while and udevd will log an error message at
40 startup. It should still be able to boot-up, but advanced rules and system
41 services which depend on the information not available in the old sysfs
42 format will fail to work correctly.
44 DVB device naming is supplied by the kernel now. In case older kernels
45 need to be supported, the old shell script should be added to a compat
52 The processed udev events get send back to the netlink socket. Libudev
53 provides access to these events. This is work-in-progress, to replace
54 the DeviceKit daemon functionality directly with libudev. There are
55 upcoming kernel changes to allow non-root users to subcribe to these
62 "udevadm settle" now optionally accepts a range of events to wait for,
63 instead of waiting for "all" events.
69 The installed watch for block device metadata changes is now removed
70 during event hadling, because some (broken) tools may be called from udev
71 rules and (wrongly) open the device with write access. After the finished
72 event handling the watch is restored.
78 Device nodes can be watched for changes with inotify with OPTIONS="watch".
79 If closed after being opened for writing, a "change" uevent will occur.
80 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
86 The udevadm test command has no longer a --force option, nodes and symlinks
87 are always updated with a test run now.
89 The udevd daemon can be started with --resolve-names=never to avoid all user
90 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
91 lookup user and groups every time events are handled.
97 We are currently merging the Ubuntu rules in the udev default rules,
98 and get one step closer to provide a common Linux /dev setup, regarding
99 device names, symlinks, and default device permissions. On udev startup,
100 we now expect the following groups to be resolvable to their ids with
102 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
103 LDAP setups need to make sure, that these groups are always resolvable at
104 bootup, with only the rootfs mounted, and without network access available.
106 Some systems may need to add some new, currently not used groups, or need
107 to add some users to new groups, but the cost of this change is minimal,
108 compared to the pain the current, rather random, differences between the
109 various distributions cause for upstream projects and third-party vendors.
111 In general, "normal" users who log into a machine should never be a member
112 of any such group, but the device-access should be managed by dynamic ACLs,
113 which get added and removed for the specific users on login/logout and
114 session activity/inactivity. These groups are only provided for custom setups,
115 and mainly system services, to allow proper privilege separation.
116 A video-streaming daemon uid would be a member of "audio" and "video", to get
117 access to the sound and video devices, but no "normal" user should ever belong
118 to the "audio" group, because he could listen to the built-in microphone with
119 any ssh-session established from the other side of the world.
121 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
122 which do not depend on the kernel device name. As usual, unique
123 devices - only a single one per product connected, or a real
124 USB serial number in the device - are always found with the same
125 name in the by-id/ directory.
126 Completely identical devices may overwrite their names in by-id/
127 and can only be found reliably in the by-path/ directory. Devices
128 specified by by-path/ must not change their connection, like the
129 USB port number they are plugged in, to keep their name.
131 To support some advanced features, Linux 2.6.22 is the oldest supported
132 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
133 supported. Older kernels should still work, and devices nodes should be
134 reliably created, but some rules and libudev will not work correctly because
135 the old kernels do not provide the expected information or interfaces.
141 Fix for a possible segfault while swapping network interface names in udev
148 The group "video" is part of the default rules now.
152 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
153 block devices in some cases. No common distro uses this option anymore,
154 and we do not get enough testing for this and recent udev versions. If
155 this option is not needed to run some old distro with a new kernel,
156 it should be disabled in the kernel config.
158 Bugfix for the $links substitution variable, which may crash if no links
159 are created. This should not happen in usual setups because we always
160 create /dev/{block,char}/ links.
162 The strings of the parsed rules, which are kept in memory, no longer
163 contain duplicate entries, or duplicate tails of strings. This, and the
164 new rules parsing/matching code reduces the total in-memory size of
165 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
168 The export of DEVTYPE=disk/partition got removed from the default
169 rules. This value is available from the kernel. The pnp shell script
170 modprobe hack is removed from the default rules. ACPI devices have _proper_
171 modalias support and take care of the same functionality.
172 Installations which support old kernels, but install current default
173 udev rules may want to add that to the compat rules file.
175 Libvolume_id now always probes for all known filesystems, and does not
176 stop at the first match. Some filesystems are marked as "exclusive probe",
177 and if any other filesytem type matches at the same time, libvolume_id
178 will, by default, not return any probing result. This is intended to prevent
179 mis-detection with conflicting left-over signatures found from earlier
180 file system formats. That way, we no longer depend on the probe-order
181 in case of multiple competing signatures. In some setups the kernel allows
182 to mount a volume with just the old filesystem signature still in place.
183 This may damage the new filesystem and cause data-loss, just by mounting
184 it. Because volume_id can not decide which one the correct signature is,
185 the wrong signatures need to be removed manually from the volume, or the
186 volume needs to be reformatted, to enable filesystem detection and possible
191 Fix segfault if compiled without optimization and dbg() does not get
192 compiled out and uses variables which are not available.
196 Bugfixes. (And maybe new bugs. :))
198 The rule matching engine got converted from a rule list to a token
199 array which reduced the in-memory rules representation of a full
200 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
201 Limits like 5 ENV and ATTR matches, and one single instance for most
202 other keys per rule are gone.
204 The NAME assignment is no longer special cased. If later rules assign
205 a NAME value again, the former value will be overwritten. As usual
206 for most other keys, the NAME value can be protected by doing a final
207 assignment with NAME:="<value>".
209 All udev code now uses libudev, which is also exported. The library
210 is still under development, marked as experimental, and its interface
211 may change as long as the DeviceKit integration is not finished.
213 Many thanks to Alan Jenkins for his continuous help, and finding and
214 optimizing some of the computing expensive parts.
220 Kernel devices and device nodes are connected now by reverse indizes in
221 /sys and /dev. A device number retrieved by a stat() or similar, the
222 kernel device directory can be found by looking up:
223 /sys/dev/{block,char}/<maj>:<min>
224 and the device node of the same device by looking up:
225 /dev/{block,char}/<maj>:<min>
229 Fix recently introduced bug, which caused a compilation without large
230 file support, where vol_id does not recognize raid signatures at the end
233 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
234 Seems some kernel versions prevent the creation of the ieee-* links,
235 so people used the scsi-* link which disappeared now.
237 More libudev work. Almost all udevadm functionality comes from libudev
240 udevadm trigger has a new option --type, which allows to trigger events
241 for "devices", for "subsystems", or "failed" devices. The old option
242 --retry-failed" still works, but is no longer mentioned in the man page.
248 The udevadm info --device-id-of-file= output has changed to use
249 the obvious format. Possible current users should use the --export
250 option which is not affected.
252 The old udev commands symlinks to udevadm are not installed, if
253 these symlinks are used, a warning is printed.
259 Optical drive's media is no longer probed for raid signatures,
260 reading the end of the device causes some devices to malfunction.
261 Also the offset of the last session found is used now to probe
264 The volume_id library got a major version number update to 1,
265 some deprecated functions are removed.
267 A shared library "libudev" gets installed now to provide access
268 to udev device information. DeviceKit, the successor of HAL, will
269 need this library to access the udev database and search sysfs for
271 The library is currently in an experimental state, also the API is
272 expected to change, as long as the DeviceKit integration is not
277 We use ./configure now. See INSTALL for details. Current
280 "/usr" - prefix for man pages, include files
282 "" - the root filesystem, prefix for libs and binaries
286 "lib" - directory name for libraries, not a path name
287 multilib 64bit systems may use "lib64" instead of "lib"
289 compile-in verbose debug messages
291 disable all logging and compile-out all log strings
293 link against SELInux libraries, to set the expected context
296 In the default rules, the group "disk" gets permissions 0660 instead
297 of 0640. One small step closer to unify distro rules. Some day, all
298 distros hopefully end up with the same set of rules.
300 No symlinks to udevadm are installed anymore, if they are still needed,
301 they should be provided by the package.
307 Default udev rules, which are not supposed to be edited by the user, should
308 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
309 the udev package and will be replaced with an update. Udev will pick up rule
311 /lib/udev/rules.d/ - default installed rules
312 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
313 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
314 It does not matter in which directory a rule file lives, all files are sorted
317 To help creating /dev/root, we have now:
318 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
321 In case the current --device-id-of-file is already used, please switch to
322 the --export format version, it saves the output parsing and the old
323 format will be changed to use ':' as a separator, like the format in the
328 Fix cdrom_id to properly recognize blank media.
334 Tape drive id-data is queried from /dev/bsg/* instead of the tape
335 nodes. This avoids rewinding tapes on open().
341 The symlinks udevcontrol and udevtrigger are no longer installed by
344 The scsi_id program does not depend on sysfs anymore. It can speak
345 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
346 data, which should solve some old problems with tape devices, where
347 we better do not open all tape device nodes to identify the device.
353 The cdrom_id program is replaced by an advanced version, which can
354 detect most common device types, and also properties of the inserted
355 media. This is part of moving some basic functionality from HAL into
356 udev (and the kernel).
362 The last WAIT_FOR_SYSFS rule is removed from the default rules.
364 The symlinks to udevadm for the debugging tools: udevmonitor and
365 udevtest are no longer created.
367 The symlinks to the udevadm man page for the old tool names are
370 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
371 should be prefixed with '@' to indicate that the path is not a
382 Udevstart is removed from the tree, it did not get installed for
383 a long time now, and is long replaced by trigger and settle.
389 All udev tools are merged into a single binary called udevadm.
390 The old names of the tools are built-in commands in udevadm now.
391 Symlinks to udevadm, with the names of the old tools, provide
392 the same functionality as the standalone tools. There is also
393 only a single udevadm.8 man page left for all tools.
395 Tools like mkinitramfs should be checked, if they need to include
396 udevadm in the list of files.
406 The etc/udev/rules.d/ directory now contains a default set of basic
407 udev rules. This initial version is the result of a rules file merge
408 of Fedora and openSUSE. For these both distros only a few specific
409 rules are left in their own file, named after the distro. Rules which
410 are optionally installed, because they are only valid for a specific
411 architecture, or rules for subsystems which are not always used are
412 in etc/udev/packages/.
418 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
419 actions by dynamically created rules.
421 SYMLINK=="<value>" matches agains the entries in the list of
422 currently defined symlinks. The links are not created in the
423 filesystem at that point in time, but the values can be matched.
425 RUN{ignore_error}+="<program>" will ignore any exit code from the
426 program and not record as a failed event.
432 Final merge of patches/features from the Ubuntu package.
438 Control characters in filesystem label strings are no longer silenty
439 removed, but hex-encoded, to be able to uniquely identify the device
440 by its symlink in /dev/disk/by-label/.
441 If libvolume_id is used by mount(8), LABEL= will work as expected,
442 if slashes or other characters are used in the label string.
444 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
445 can be specified now. The TEST key accepts an optional mode mask
446 TEST{0100}=="<is executable file>".
448 Scsi_id now supports a mode without expecting scsi-specific sysfs
449 entries to allow the extraction of cciss-device persistent properties.
455 In the future, we may see uuid's which are just simple character
456 strings (see the DDF Raid Specification). For that reason vol_id now
457 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
458 the creation of symlinks, the *_SAFE values ensure, that no control
459 or whitespace characters are used in the filename.
461 Possible users of libvolume_id, please use the volume_id_get_* functions.
462 The public struct will go away in a future release of the library.
468 Removal of useless extras/eventrecorder.sh.
478 The directory multiplexer for dev.d/ and hotplug.d are finally removed
479 from the udev package.
485 Symlinks can have priorities now, the priority is assigned to the device
486 and specified with OPTIONS="link_priority=100". Devices with higher
487 priorities overwrite the symlinks of devices with lower priorities.
488 If the device that currently owns the link, goes away, the symlink
489 will be removed, and recreated, pointing to the next device with the
490 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
491 more reliable, if multiple devices contain the same metadata and overwrite
494 The dasd_id program is removed from the udev tree, and dasdinfo, with the
495 needed rules, are part of the s390-tools now.
497 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
498 we may get the scsi sysfs mess fixed some day, and this will only catch
499 the devices we are looking for.
501 USB serial numbers for storage devices have the target:lun now appended,
502 to make it possibble to distinguish broken multi-lun devices with all
503 the same SCSI identifiers.
505 Note: The extra "run_directory" which searches and executes stuff in
506 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
507 with the next release. Make sure, that you don't use it anymore, or
508 provides your own implementation of that inefficient stuff.
509 We are tired of reports about a "slow udev", because these directories
510 contain stuff, that runs with _every_ event, instead of using rules,
511 that run programs only for the matching events.
521 DRIVER== will match only for devices that actually have a real
522 driver. DRIVERS== must be used, if parent devices should be
523 included in the match.
525 Libvolume_id's "linux_raid" detection needed another fix.
533 Add additional check to volume_id detection of via_raid, cause
534 some company decided to put a matching pattern all over the empty
535 storage area of their music players.
539 Fix path_id for SAS devices.
543 The udev daemon can be started with --debug-trace now, which will
544 execute all events serialized to get a chance to catch a possible
545 action that crashes the box.
547 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
548 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
549 are excluded from the warning. Referencing parent attributes directly
550 may break when something in the kernel driver model changes. Udev will
551 just find the attribute by walking up the parent chain.
553 Udevtrigger now sorts the list of devices depending on the device
554 dependency, so a "usb" device is triggered after the parent "pci"
559 Revert persistent-storage ata-serial '_' '-' replacement.
565 Udevtrigger can now filter the list of devices to be triggered. Matches
566 for subsystems or sysfs attributes can be specified.
568 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
569 zero-sized files to avoid pointing to /sys and confuse broken tools which
570 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
573 The rules and scripts to create udev rules for persistent network
574 devices and optical drives are in the extras/rules_generator directory
575 now. If you use something similar, please consider replacing your own
576 version with this, to share the support effort. The rule_generator
577 installs its own rules into /etc/udev/rules.d.
579 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
580 the rule_generator depends on cdrom_id to be called in an earlier rule.
586 Renaming of some key names (the old names still work):
587 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
588 (The behavior of the key DRIVER will change soon in one of the next
589 releases, to match only the event device, please switch to DRIVERS
590 instead. If DRIVER is used, it will behave like DRIVERS, but an error
592 With the new key names, we have a more consistent and simpler scheme.
593 We can match the properties of the event device only, with: KERNEL,
594 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
595 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
596 longer mentioned in the man page and should be switched in the rule
599 ATTR{file}="value" can be used now, to write to a sysfs file of the
600 event device. Instead of:
601 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
603 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
605 All the PHYSDEV* keys are deprecated and will be removed from a
607 PHYDEVPATH - is the path of a parent device and should not be
609 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
610 matched with SUBSYSTEMS==
611 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
612 Newer kernels will have DRIVER in the environment,
613 for older kernels udev puts in. Class device will
614 no longer carry this property of a parent and
615 DRIVERS== can be used to match such a parent value.
616 Note that ENV{DRIVER} is only available for a few bus devices, where
617 the driver is already bound at device event time. On coldplug, the
618 events for a lot devices are already bound to a driver, and they will have
619 that value set. But on hotplug, at the time the kernel creates the device,
620 it can't know what driver may claim the device after that, therefore
621 in most cases it will be empty.
623 Failed events should now be re-triggered with:
624 udevtrigger --retry-failed.
625 Please switch to this command, so we keep the details of the /dev/.udev/failed/
626 files private to the udev tools. We may need to switch the current symlink
627 target, cause some obviously broken tools try to scan all files in /dev
628 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
629 million times. This takes ages on slow boxes.
631 The udevinfo attribute walk (-a) now works with giving a device node
632 name (-n) instead of a devpath (-p). The query now always works, also when
633 no database file was created by udev.
635 The built-in /etc/passwd /etc/group parser is removed, we always depend on
636 getpwnam() and getgrnam() now. One of the next releases will depend on
637 fnmatch() and may use getopt_long().
641 Bugfixes and small improvements.
645 Fix path_id for recent kernels.
651 Added support for swapping network interface names, by temporarily
652 renaming the device and wait for the target name to become free.
656 The built-in MODALIAS key and substitution is removed.
660 The binary firmware helper is replaced by the usual simple
661 shell script. Udevsend is removed from the tree.
669 Some more keys require the correct use of '==' and '=' depending
670 on the kind of operation beeing an assignment or a match. Rules
671 with invalid operations are skipped and logged to syslog. Please
672 test with udevtest if the parsing of your rules throws errors and
673 fix possibly broken rules.
677 Provide "udevsettle" to wait for all current udev events to finish.
678 It also watches the current kernel netlink queue by comparing the
679 even sequence number to make sure that there are no current pending
680 events that have not already arrived in the daemon.
684 Fix rule to skip persistent rules for removable IDE devices, which
685 also skipped optical IDE drives.
687 All *_id program are installed in /lib/udev/ by default now.
689 No binary is stripped anymore as this should be done in the
690 packaging process and not at build time.
692 libvolume_id is provided as a shared library now and vol_id is
693 linked against it. Also one of the next HAL versions will require
694 this library, and the HAL build process will also require the
695 header file to be installed. The copy of the same code in HAL will
696 be removed to have only a single copy left on the system.
700 Add persistent links for SCSI tapes. The rules file is renamed
701 to 60-persistent-storage.rules.
703 Create persistent path for usb devices. Can be used for all sorts
704 of devices that can't be distinguished by other properties like
705 multiple identical keyboards and mice connected to the same box.
707 Provide "udevtrigger" program to request events on coldplug. The
708 shell script is much too slow with thousends of devices.
712 Fix persistent disk rules to exclude removable IDE drives.
714 Warn if %e, $modalias or MODALIAS is used.
718 Fix queue export, which wasn't correct for subsequent add/remove
719 events for the same device.
723 Fix cramfs detection on big endian.
725 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
730 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
731 attributes were only checked at the parent device that matched the
732 by BUS requested subsystem. Fix it to also look at the device we
733 received the event for.
735 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
740 Fix a bug where NAME="" would prevent RUN from beeing executed.
742 RUN="/bin/program" does not longer automatically add the subsystem
743 as the first parameter. This is from the days of /sbin/hotplug
744 which is dead now and it's just confusing to need to add a space at
745 the end of the program name to prevent this.
746 If you use rules that need the subsystem as the first parameter,
747 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
748 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
752 The udev man page has moved to udev(7) as it does not describe a command
753 anymore. The programs udev, udevstart and udevsend are no longer installed
754 by default and must be copied manually, if they should be installed or
755 included in a package.
757 Fix a bug where "ignore_device" could run earlier collected RUN keys before
758 the ignore rule was applied.
760 More preparation for future sysfs changes. usb_id and scsi_id no longer
761 depend on a magic order of devices in the /devices chain. Specific devices
762 should be requested by their subsytem.
764 This will always find the scsi parent device without depending on a specific
766 dev = sysfs_device_get(devpath);
767 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
769 The "device" link in the current sysfs layout will be automatically
770 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
771 parent in the devpath. If a device is requested by it's symlink, like all
772 class devices in the new sysfs layout will look like, it gets automatically
773 resolved and substituted with the real devpath and not the symlink path.
776 A similar logic must be applied to _all_ sysfs users, including
777 scripts, that search along parent devices in sysfs. The explicit use of
778 the "device" link must be avoided. With the future sysfs layout all
779 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
780 back to the "class" or the "bus". The layout of the parent devices in
781 /devices is not necessarily expected to be stable across kernel releases and
782 searching for parents by their subsystem should make sysfs users tolerant
783 for changed parent chains.
787 Prepare udev to work with the experimental kernel patch, that moves
788 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
790 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
791 moving the class devices to /sys/devices.
793 Thanks again to Marco for help finding a hopefully nice compromise
794 to make %b simpler and working again.
798 Complete removal of libsysfs, replaced by simple helper functions
799 which are much simpler and a bit faster. The udev daemon operatesentirely
800 on event parameters and does not use sysfs for simple rules anymore.
801 Please report any new bugs/problems, that may be caused by this big
802 change. They will be fixed immediately.
804 The enumeration format character '%e' is deprecated and will be
805 removed sometimes from a future udev version. It never worked correctly
806 outside of udevstart, so we can't use it with the new parallel
807 coldplug. A simple enumeration is as useless as the devfs naming
808 scheme, just get rid of both if you still use it.
810 MODALIAS and $modalias is not needed and will be removed from one of
811 the next udev versions, replace it in all rules with ENV{MODALIAS} or
812 the sysfs "modalias" value.
814 Thanks a lot to Marco for all his help on finding and fixing bugs.
818 Let scsi_id request libata drive serial numbers from page 0x80.
820 Renamed etc/udev/persistent.rules to persistent-disk.rules and
821 added /dev/disk/by-name/* for device mapper device names.
823 Removed %e from the man page. It never worked reliably outside
824 of udevstart and udevstart is no longer recommended to use.
828 Symlinks are now exported to the event environment. Hopefully it's no
829 longer needed to run udevinfo from an event process, like it was
830 mentioned on the hotplug list:
831 UDEV [1134776873.702967] add@/block/sdb
834 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
838 Fix a problem if udevsend is used as the hotplug handler and tries to use
839 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
840 and this kind of problems will hopefully go away soon.
844 All built-in logic to work around bad sysfs timing is removed with this
845 version. The need to wait for sysfs files is almost fixed with a kernel
846 version that doesn't work with this udev version anyway. Until we fix
847 the timing of the "bus" link creation, the former integrated logic should
848 be emulated by a rule placed before all other rules:
849 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
851 The option "udev_db" does no longer exist. All udev state will be in
852 /$udev_root/.udev/ now, there is no longer an option to set this
854 If the init script or something else used this value, just depend on
855 this hardcoded path. But remember _all_content_ of this directory is
856 still private to udev and can change at any time.
858 Default location for rule sripts and helper programs is now: /lib/udev/.
859 Everything that is not useful on the commandline should go into this
860 directory. Some of the helpers in the extras folder are installed there
861 now. The rules need to be changed, to find the helpers there.
863 Also /lib/udev/devices is recommended as a directory where packages or
864 the user can place real device nodes, which get copied over to /dev at
865 every boot. This should replace the various solutions with custom config
868 Udevsend does no longer start the udev daemon. This must be done with
869 the init script that prepares /dev on tmpfs and creates the initial nodes,
870 before starting the daemon.
874 Silent a too verbose error logging for the old hotplug.d/ dev.d/
877 The copy of klibc is removed. A systemwide installed version of klibc
878 should be used to build a klibc udev now.
882 NAME="" will not create any nodes, but execute RUN keys. To completely
883 ignore an event the OPTION "ignore_device" should be used.
885 After removal of the reorder queue, events with a TIMEOUT can be executed
886 without any queuing now.
890 Fixed bug in udevd, if inotify is not available. We depend on netlink
891 uevents now, kernels without that event source will not work with that
892 version of udev anymore.
896 The rule parsing happens now in the daemon once at startup, all udev
897 event processes inherit the already parsed rules from the daemon.
898 It is shipped with SUSE10.0 and reduces heavily the system load at
899 startup. The option to save precompiled rules and let the udev process
900 pick the them up is removed, as it's no longer needed.
902 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
903 device. Libsysfs is changed to "translate" the requested link into the
904 real device path, as it would happen with the hotplug event. Otherwise
905 device removal and the udev database will not work.
907 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
910 A few improvements for vol_id, the filesytem probing code.
914 Fix a stupid typo in extras/run_directory for "make install".
916 scsi_id creates the temporary devnode now in /dev for usage with a
917 non-writable /tmp directory.
919 The uevent kernel socket buffer can carry app. 50.000 events now,
920 let's see who can break this again. :)
922 The upcoming kernel will have a new input driver core integration.
923 Some class devices are now symlinks to the real device. libsysfs
924 needs a fix for this to work correctly. Udevstart of older udev
925 versions will _not_ create these devices!
929 Fix a 'install' target in the Makefile, that prevents EXTRAS from
934 A bunch of mostly trivial bugfixes. From now on no node name or
935 symlink name can contain any character than plain whitelisted ascii
936 characters or validated utf8 byte-streams. This is needed for the
937 /dev/disk/by-label/* links, because we import untrusted data and
938 export it to the filesystem.
942 More bugfixes. If udevd was started from the kernel, we don't
943 have stdin/stdout/stderr, which broke the forked tools in some
948 Bugfix. udevstart event ordering was broken for a long time.
949 The new run_program() uncovered it, because /dev/null was not
950 available while we try to run external programs.
951 Now udevstart should create it before we run anything.
955 Minor bugfixes and some distro rules updates. If you don't have the
956 persistent disk rules in /dev/disk/by-*/* on your distro, just
957 grab it from here. :)
961 We can use socket communication now to pass events from udev to
963 RUN+="socket:/org/freedesktop/hal/udev_event"
964 will pass the whole udev event to the HAL daemon without the need
965 for a forked helper. (See ChangeLog for udevmonitor, as an example)
969 Mostly bugfixes and see ChangeLog.
971 The test for the existence of an environment value should be
973 ENV{KEY}=="*" to ENV{KEY}=="?*"
974 because "*" will not fail anymore, if the key does not exist or
979 Bugfixes and a few tweaks described in the ChangeLog.
983 Mostly a Bugfix release.
985 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
986 timing with custom rules.
990 We changed the internal rule storage format. Our large rule files took
991 2 MB of RAM, with the change we are down to 99kB.
993 If the device-node has been created with default name and no symlink or
994 options are to remenber, it is not longer stored in the udevdb. HAL will
995 need to be updated to work correctly with that change.
997 To overrride optimization flags, OPTFLAGS may be used now.
1005 Major changes happened with this release. The goal is to take over the
1006 complete kernel-event handling and provide a more efficient way to dispatch
1007 kernel events. Replacing most of the current shell script logic and the
1008 kernel forked helper with a netlink-daemon and a rule-based event handling.
1010 o udevd listens to netlink events now. The first valid netlink event
1011 will make udevd ignore any message from udevsend that contains a
1012 SEQNUM, to avoid duplicate events. The forked events can be disabled
1014 echo "" > /proc/sys/kernel/hotplug
1015 For full support, the broken input-subsytem needs to be fixed, not to
1016 bypass the driver core.
1018 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1019 removed from udev itself and must be emulated by calling small
1020 helper binaries provided in the extras folder:
1021 make EXTRAS=extras/run_directory/
1022 will build udev_run_devd and udev_run_hotplugd, which can be called
1023 from a rule if needed:
1024 RUN+="/sbin/udev_run_hotplugd"
1025 The recommended way to handle this is to convert all the calls from
1026 the directories to explicit udev rules and get completely rid of the
1027 multiplexing. (To catch a ttyUSB event, you now no longer need to
1028 fork and exit 300 tty script instances you are not interested in, it
1029 is just one rule that matches exactly the device.)
1031 o udev handles now _all_ events not just events for class and block
1032 devices, this way it is possible to control the complete event
1033 behavior with udev rules. Especially useful for rules like:
1034 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1036 o As used in the modalias rule, udev supports now textual
1037 substitution placeholder along with the usual format chars. This
1038 needs to be documented, for now it's only visible in udev_rules_parse.c.
1040 o The rule keys support now more operations. This is documented in the
1041 man page. It is possible to add values to list-keys like the SYMLINK
1042 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1043 Also "final"-assignments are supported by using KEY:="value", which will
1044 prevent changing the key by any later rule.
1046 o kernel 2.6.12 has the "detached_state" attribute removed from
1047 sysfs, which was used to recognize sysfs population. We switched that
1048 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1049 Running this udev version on older kernels may cause a short delay for
1052 o To provide infrastructure for persistent device naming, the id programs:
1053 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1054 to export the probed data in environment key format:
1055 pim:~ # /sbin/ata_id --export /dev/hda
1056 ID_MODEL=HTS726060M9AT00
1057 ID_SERIAL=MRH401M4G6UM9B
1058 ID_REVISION=MH4OA6BA
1060 The following rules:
1061 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1062 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1065 kay@pim:~> tree /dev/disk
1068 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1069 | `-- IBM-Memory_Key -> ../../sda
1071 | |-- swap -> ../../hda1
1072 | |-- date -> ../../sda1
1073 | `-- home -> ../../hda3
1075 |-- 2E08712B0870F2E7 -> ../../hda3
1076 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1077 |-- E845-7A89 -> ../../sda1
1078 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1080 The IMPORT= operation will import these keys in the environment and make
1081 it available for later PROGRAM= and RUN= executed programs. The keys are
1082 also stored in the udevdb and can be queried from there with one of the
1085 o A few binaries are silently added to the repository, which can be used
1086 to replay kernel events from initramfs instead of using coldplug. udevd
1087 can be instructed now to queue-up events while the stored events from
1088 initramfs are filled into the udevd-queue. This code is still under
1089 development and there is no documentation now besides the code itself.
1090 The additional binaries get compiled, but are not installed by default.
1092 o There is also a temporary fix for a performance problem where too many
1093 events happen in parallel and every event needs to parse the rules.
1094 udev can now read precompiled rules stored on disk. This is likely to be
1095 replaced by a more elegant solution in a future udev version.
1099 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1100 Fix for libsysfs not to expect this file was added.
1104 All rules are applied now, but only the first matching rule with a NAME-key
1105 will be applied. All later rules with NAME-key are completely ignored. This
1106 way system supplied symlinks or permissions gets applied to user-defined
1110 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1111 to some rules, to keep the old behavior.
1113 The rules are read on "remove"-events too. That makes is possible to match
1114 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1115 instruct udev to ignore an event (OPTIONS="ignore_device").
1116 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1118 The new RUN-key supports rule-based execution of programs after device-node
1119 handling. This is meant as a general replacement for the dev.d/-directories
1120 to give fine grained control over the execution of programs.
1122 The %s{}-sysfs format char replacement values are searched at any of the
1123 devices in the device chain now, not only at the class-device.
1125 We support log priority levels now. The value udev_log in udev.conf is used
1126 to determine what is printed to syslog. This makes it possible to
1127 run a version with compiled-in debug messages in a production environment
1128 which is sometimes needed to find a bug.
1129 It is still possible to supress the inclusion of _any_ syslog usage with
1130 USE_LOG=false to create the smallest possible binaries if needed.
1131 The configured udev_log value can be overridden with the environment variable
1136 Possible use of a system-wide klibc:
1137 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1138 will link against an external klibc and our own version will be ignored.
1142 We support an unlimited count of symlinks now.
1144 If USE_STATIC=true is passed to a glibc build, we link statically and use
1145 a built-in userdb parser to resolve user and group names.
1147 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1148 we walk up the chain of physical devices to find a match.
1150 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1151 easy to skip certain attribute matches without composing rules with weird
1152 character class negations like:
1153 KERNEL="[!s][!c][!d]*"
1154 this can now be replaced with:
1156 The current simple '=' is still supported, and should work as it does today,
1157 but existing rules should be converted if possible, to be better readable.
1159 We have new ENV{}== key now, to match against a maximum of 5 environment
1162 udevstart is its own binary again, because we don't need co carry this araound
1163 with every forked event.