3 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
4 block devices in some cases. No common distro uses this option anymore,
5 and we do not get enough testing for this and recent udev versions. If
6 this option is not needed to run some old distro with a new kernel,
7 it should be disabled in the kernel config.
9 Bugfix for the $links substitution variable, which may crash if no links
10 are created. This should not happen in usual setups because we always
11 create /dev/{block,char}/ links.
13 The strings of the parsed rules, which are kept in memory, no longer
14 contain duplicate entries, or duplicate tails of strings. This, and the
15 new rules parsing/matching code reduces the total in-memory size of
16 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
19 The export of DEVTYPE=disk/partition got removed from the default
20 rules. This value is available from the kernel. The pnp shell script
21 modprobe hack is removed from the default rules. ACPI devices have _proper_
22 modalias support and take care of the same functionality.
23 Installations which support old kernels, but install current default
24 udev rules may want to add that to the compat rules file.
26 Libvolume_id now always probes for all known filesystems, and does not
27 stop at the first match. Some filesystems are marked as "exclusive probe",
28 and if any other filesytem type matches at the same time, libvolume_id
29 will, by default, not return any probing result. This is intended to prevent
30 mis-detection with conflicting left-over signatures found from earlier
31 file system formats. That way, we no longer depend on the probe-order
32 in case of multiple competing signatures. In some setups the kernel allows
33 to mount a volume with just the old filesystem signature still in place.
34 This may damage the new filesystem and cause data-loss, just by mounting
35 it. Because volume_id can not decide which one the correct signature is,
36 the wrong signatures need to be removed manually from the volume, or the
37 volume needs to be reformatted, to enable filesystem detection and possible
43 Fix segfault if compiled without optimization and dbg() does not get
44 compiled out and uses variables which are not available.
48 Bugfixes. (And maybe new bugs. :))
50 The rule matching engine got converted from a rule list to a token
51 array which reduced the in-memory rules representation of a full
52 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
53 Limits like 5 ENV and ATTR matches, and one single instance for most
54 other keys per rule are gone.
56 The NAME assignment is no longer special cased. If later rules assign
57 a NAME value again, the former value will be overwritten. As usual
58 for most other keys, the NAME value can be protected by doing a final
59 assignment with NAME:="<value>".
61 All udev code now uses libudev, which is also exported. The library
62 is still under development, marked as experimental, and its interface
63 may change as long as the DeviceKit integration is not finished.
65 Many thanks to Alan Jenkins for his continuous help, and finding and
66 optimizing some of the computing expensive parts.
72 Kernel devices and device nodes are connected now by reverse indizes in
73 /sys and /dev. A device number retrieved by a stat() or similar, the
74 kernel device directory can be found by looking up:
75 /sys/dev/{block,char}/<maj>:<min>
76 and the device node of the same device by looking up:
77 /dev/{block,char}/<maj>:<min>
81 Fix recently introduced bug, which caused a compilation without large
82 file support, where vol_id does not recognize raid signatures at the end
85 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
86 Seems some kernel versions prevent the creation of the ieee-* links,
87 so people used the scsi-* link which disappeared now.
89 More libudev work. Almost all udevadm functionality comes from libudev
92 udevadm trigger has a new option --type, which allows to trigger events
93 for "devices", for "subsystems", or "failed" devices. The old option
94 --retry-failed" still works, but is no longer mentioned in the man page.
100 The udevadm info --device-id-of-file= output has changed to use
101 the obvious format. Possible current users should use the --export
102 option which is not affected.
104 The old udev commands symlinks to udevadm are not installed, if
105 these symlinks are used, a warning is printed.
111 Optical drive's media is no longer probed for raid signatures,
112 reading the end of the device causes some devices to malfunction.
113 Also the offset of the last session found is used now to probe
116 The volume_id library got a major version number update to 1,
117 some deprecated functions are removed.
119 A shared library "libudev" gets installed now to provide access
120 to udev device information. DeviceKit, the successor of HAL, will
121 need this library to access the udev database and search sysfs for
123 The library is currently in an experimental state, also the API is
124 expected to change, as long as the DeviceKit integration is not
129 We use ./configure now. See INSTALL for details. Current
132 "/usr" - prefix for man pages, include files
134 "" - the root filesystem, prefix for libs and binaries
138 "lib" - directory name for libraries, not a path name
139 multilib 64bit systems may use "lib64" instead of "lib"
141 compile-in verbose debug messages
143 disable all logging and compile-out all log strings
145 link against SELInux libraries, to set the expected context
148 In the default rules, the group "disk" gets permissions 0660 instead
149 of 0640. One small step closer to unify distro rules. Some day, all
150 distros hopefully end up with the same set of rules.
152 No symlinks to udevadm are installed anymore, if they are still needed,
153 they should be provided by the package.
159 Default udev rules, which are not supposed to be edited by the user, should
160 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
161 the udev package and will be replaced with an update. Udev will pick up rule
163 /lib/udev/rules.d/ - default installed rules
164 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
165 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
166 It does not matter in which directory a rule file lives, all files are sorted
169 To help creating /dev/root, we have now:
170 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
173 In case the current --device-id-of-file is already used, please switch to
174 the --export format version, it saves the output parsing and the old
175 format will be changed to use ':' as a separator, like the format in the
180 Fix cdrom_id to properly recognize blank media.
186 Tape drive id-data is queried from /dev/bsg/* instead of the tape
187 nodes. This avoids rewinding tapes on open().
193 The symlinks udevcontrol and udevtrigger are no longer installed by
196 The scsi_id program does not depend on sysfs anymore. It can speak
197 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
198 data, which should solve some old problems with tape devices, where
199 we better do not open all tape device nodes to identify the device.
205 The cdrom_id program is replaced by an advanced version, which can
206 detect most common device types, and also properties of the inserted
207 media. This is part of moving some basic functionality from HAL into
208 udev (and the kernel).
214 The last WAIT_FOR_SYSFS rule is removed from the default rules.
216 The symlinks to udevadm for the debugging tools: udevmonitor and
217 udevtest are no longer created.
219 The symlinks to the udevadm man page for the old tool names are
222 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
223 should be prefixed with '@' to indicate that the path is not a
234 Udevstart is removed from the tree, it did not get installed for
235 a long time now, and is long replaced by trigger and settle.
241 All udev tools are merged into a single binary called udevadm.
242 The old names of the tools are built-in commands in udevadm now.
243 Symlinks to udevadm, with the names of the old tools, provide
244 the same functionality as the standalone tools. There is also
245 only a single udevadm.8 man page left for all tools.
247 Tools like mkinitramfs should be checked, if they need to include
248 udevadm in the list of files.
258 The etc/udev/rules.d/ directory now contains a default set of basic
259 udev rules. This initial version is the result of a rules file merge
260 of Fedora and openSUSE. For these both distros only a few specific
261 rules are left in their own file, named after the distro. Rules which
262 are optionally installed, because they are only valid for a specific
263 architecture, or rules for subsystems which are not always used are
264 in etc/udev/packages/.
270 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
271 actions by dynamically created rules.
273 SYMLINK=="<value>" matches agains the entries in the list of
274 currently defined symlinks. The links are not created in the
275 filesystem at that point in time, but the values can be matched.
277 RUN{ignore_error}+="<program>" will ignore any exit code from the
278 program and not record as a failed event.
284 Final merge of patches/features from the Ubuntu package.
290 Control characters in filesystem label strings are no longer silenty
291 removed, but hex-encoded, to be able to uniquely identify the device
292 by its symlink in /dev/disk/by-label/.
293 If libvolume_id is used by mount(8), LABEL= will work as expected,
294 if slashes or other characters are used in the label string.
296 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
297 can be specified now. The TEST key accepts an optional mode mask
298 TEST{0100}=="<is executable file>".
300 Scsi_id now supports a mode without expecting scsi-specific sysfs
301 entries to allow the extraction of cciss-device persistent properties.
307 In the future, we may see uuid's which are just simple character
308 strings (see the DDF Raid Specification). For that reason vol_id now
309 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
310 the creation of symlinks, the *_SAFE values ensure, that no control
311 or whitespace characters are used in the filename.
313 Possible users of libvolume_id, please use the volume_id_get_* functions.
314 The public struct will go away in a future release of the library.
320 Removal of useless extras/eventrecorder.sh.
330 The directory multiplexer for dev.d/ and hotplug.d are finally removed
331 from the udev package.
337 Symlinks can have priorities now, the priority is assigned to the device
338 and specified with OPTIONS="link_priority=100". Devices with higher
339 priorities overwrite the symlinks of devices with lower priorities.
340 If the device that currently owns the link, goes away, the symlink
341 will be removed, and recreated, pointing to the next device with the
342 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
343 more reliable, if multiple devices contain the same metadata and overwrite
346 The dasd_id program is removed from the udev tree, and dasdinfo, with the
347 needed rules, are part of the s390-tools now.
349 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
350 we may get the scsi sysfs mess fixed some day, and this will only catch
351 the devices we are looking for.
353 USB serial numbers for storage devices have the target:lun now appended,
354 to make it possibble to distinguish broken multi-lun devices with all
355 the same SCSI identifiers.
357 Note: The extra "run_directory" which searches and executes stuff in
358 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
359 with the next release. Make sure, that you don't use it anymore, or
360 provides your own implementation of that inefficient stuff.
361 We are tired of reports about a "slow udev", because these directories
362 contain stuff, that runs with _every_ event, instead of using rules,
363 that run programs only for the matching events.
373 DRIVER== will match only for devices that actually have a real
374 driver. DRIVERS== must be used, if parent devices should be
375 included in the match.
377 Libvolume_id's "linux_raid" detection needed another fix.
385 Add additional check to volume_id detection of via_raid, cause
386 some company decided to put a matching pattern all over the empty
387 storage area of their music players.
391 Fix path_id for SAS devices.
395 The udev daemon can be started with --debug-trace now, which will
396 execute all events serialized to get a chance to catch a possible
397 action that crashes the box.
399 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
400 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
401 are excluded from the warning. Referencing parent attributes directly
402 may break when something in the kernel driver model changes. Udev will
403 just find the attribute by walking up the parent chain.
405 Udevtrigger now sorts the list of devices depending on the device
406 dependency, so a "usb" device is triggered after the parent "pci"
411 Revert persistent-storage ata-serial '_' '-' replacement.
417 Udevtrigger can now filter the list of devices to be triggered. Matches
418 for subsystems or sysfs attributes can be specified.
420 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
421 zero-sized files to avoid pointing to /sys and confuse broken tools which
422 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
425 The rules and scripts to create udev rules for persistent network
426 devices and optical drives are in the extras/rules_generator directory
427 now. If you use something similar, please consider replacing your own
428 version with this, to share the support effort. The rule_generator
429 installs its own rules into /etc/udev/rules.d.
431 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
432 the rule_generator depends on cdrom_id to be called in an earlier rule.
438 Renaming of some key names (the old names still work):
439 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
440 (The behavior of the key DRIVER will change soon in one of the next
441 releases, to match only the event device, please switch to DRIVERS
442 instead. If DRIVER is used, it will behave like DRIVERS, but an error
444 With the new key names, we have a more consistent and simpler scheme.
445 We can match the properties of the event device only, with: KERNEL,
446 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
447 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
448 longer mentioned in the man page and should be switched in the rule
451 ATTR{file}="value" can be used now, to write to a sysfs file of the
452 event device. Instead of:
453 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
455 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
457 All the PHYSDEV* keys are deprecated and will be removed from a
459 PHYDEVPATH - is the path of a parent device and should not be
461 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
462 matched with SUBSYSTEMS==
463 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
464 Newer kernels will have DRIVER in the environment,
465 for older kernels udev puts in. Class device will
466 no longer carry this property of a parent and
467 DRIVERS== can be used to match such a parent value.
468 Note that ENV{DRIVER} is only available for a few bus devices, where
469 the driver is already bound at device event time. On coldplug, the
470 events for a lot devices are already bound to a driver, and they will have
471 that value set. But on hotplug, at the time the kernel creates the device,
472 it can't know what driver may claim the device after that, therefore
473 in most cases it will be empty.
475 Failed events should now be re-triggered with:
476 udevtrigger --retry-failed.
477 Please switch to this command, so we keep the details of the /dev/.udev/failed/
478 files private to the udev tools. We may need to switch the current symlink
479 target, cause some obviously broken tools try to scan all files in /dev
480 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
481 million times. This takes ages on slow boxes.
483 The udevinfo attribute walk (-a) now works with giving a device node
484 name (-n) instead of a devpath (-p). The query now always works, also when
485 no database file was created by udev.
487 The built-in /etc/passwd /etc/group parser is removed, we always depend on
488 getpwnam() and getgrnam() now. One of the next releases will depend on
489 fnmatch() and may use getopt_long().
493 Bugfixes and small improvements.
497 Fix path_id for recent kernels.
503 Added support for swapping network interface names, by temporarily
504 renaming the device and wait for the target name to become free.
508 The built-in MODALIAS key and substitution is removed.
512 The binary firmware helper is replaced by the usual simple
513 shell script. Udevsend is removed from the tree.
521 Some more keys require the correct use of '==' and '=' depending
522 on the kind of operation beeing an assignment or a match. Rules
523 with invalid operations are skipped and logged to syslog. Please
524 test with udevtest if the parsing of your rules throws errors and
525 fix possibly broken rules.
529 Provide "udevsettle" to wait for all current udev events to finish.
530 It also watches the current kernel netlink queue by comparing the
531 even sequence number to make sure that there are no current pending
532 events that have not already arrived in the daemon.
536 Fix rule to skip persistent rules for removable IDE devices, which
537 also skipped optical IDE drives.
539 All *_id program are installed in /lib/udev/ by default now.
541 No binary is stripped anymore as this should be done in the
542 packaging process and not at build time.
544 libvolume_id is provided as a shared library now and vol_id is
545 linked against it. Also one of the next HAL versions will require
546 this library, and the HAL build process will also require the
547 header file to be installed. The copy of the same code in HAL will
548 be removed to have only a single copy left on the system.
552 Add persistent links for SCSI tapes. The rules file is renamed
553 to 60-persistent-storage.rules.
555 Create persistent path for usb devices. Can be used for all sorts
556 of devices that can't be distinguished by other properties like
557 multiple identical keyboards and mice connected to the same box.
559 Provide "udevtrigger" program to request events on coldplug. The
560 shell script is much too slow with thousends of devices.
564 Fix persistent disk rules to exclude removable IDE drives.
566 Warn if %e, $modalias or MODALIAS is used.
570 Fix queue export, which wasn't correct for subsequent add/remove
571 events for the same device.
575 Fix cramfs detection on big endian.
577 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
582 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
583 attributes were only checked at the parent device that matched the
584 by BUS requested subsystem. Fix it to also look at the device we
585 received the event for.
587 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
592 Fix a bug where NAME="" would prevent RUN from beeing executed.
594 RUN="/bin/program" does not longer automatically add the subsystem
595 as the first parameter. This is from the days of /sbin/hotplug
596 which is dead now and it's just confusing to need to add a space at
597 the end of the program name to prevent this.
598 If you use rules that need the subsystem as the first parameter,
599 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
600 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
604 The udev man page has moved to udev(7) as it does not describe a command
605 anymore. The programs udev, udevstart and udevsend are no longer installed
606 by default and must be copied manually, if they should be installed or
607 included in a package.
609 Fix a bug where "ignore_device" could run earlier collected RUN keys before
610 the ignore rule was applied.
612 More preparation for future sysfs changes. usb_id and scsi_id no longer
613 depend on a magic order of devices in the /devices chain. Specific devices
614 should be requested by their subsytem.
616 This will always find the scsi parent device without depending on a specific
618 dev = sysfs_device_get(devpath);
619 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
621 The "device" link in the current sysfs layout will be automatically
622 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
623 parent in the devpath. If a device is requested by it's symlink, like all
624 class devices in the new sysfs layout will look like, it gets automatically
625 resolved and substituted with the real devpath and not the symlink path.
628 A similar logic must be applied to _all_ sysfs users, including
629 scripts, that search along parent devices in sysfs. The explicit use of
630 the "device" link must be avoided. With the future sysfs layout all
631 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
632 back to the "class" or the "bus". The layout of the parent devices in
633 /devices is not necessarily expected to be stable across kernel releases and
634 searching for parents by their subsystem should make sysfs users tolerant
635 for changed parent chains.
639 Prepare udev to work with the experimental kernel patch, that moves
640 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
642 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
643 moving the class devices to /sys/devices.
645 Thanks again to Marco for help finding a hopefully nice compromise
646 to make %b simpler and working again.
650 Complete removal of libsysfs, replaced by simple helper functions
651 which are much simpler and a bit faster. The udev daemon operatesentirely
652 on event parameters and does not use sysfs for simple rules anymore.
653 Please report any new bugs/problems, that may be caused by this big
654 change. They will be fixed immediately.
656 The enumeration format character '%e' is deprecated and will be
657 removed sometimes from a future udev version. It never worked correctly
658 outside of udevstart, so we can't use it with the new parallel
659 coldplug. A simple enumeration is as useless as the devfs naming
660 scheme, just get rid of both if you still use it.
662 MODALIAS and $modalias is not needed and will be removed from one of
663 the next udev versions, replace it in all rules with ENV{MODALIAS} or
664 the sysfs "modalias" value.
666 Thanks a lot to Marco for all his help on finding and fixing bugs.
670 Let scsi_id request libata drive serial numbers from page 0x80.
672 Renamed etc/udev/persistent.rules to persistent-disk.rules and
673 added /dev/disk/by-name/* for device mapper device names.
675 Removed %e from the man page. It never worked reliably outside
676 of udevstart and udevstart is no longer recommended to use.
680 Symlinks are now exported to the event environment. Hopefully it's no
681 longer needed to run udevinfo from an event process, like it was
682 mentioned on the hotplug list:
683 UDEV [1134776873.702967] add@/block/sdb
686 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
690 Fix a problem if udevsend is used as the hotplug handler and tries to use
691 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
692 and this kind of problems will hopefully go away soon.
696 All built-in logic to work around bad sysfs timing is removed with this
697 version. The need to wait for sysfs files is almost fixed with a kernel
698 version that doesn't work with this udev version anyway. Until we fix
699 the timing of the "bus" link creation, the former integrated logic should
700 be emulated by a rule placed before all other rules:
701 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
703 The option "udev_db" does no longer exist. All udev state will be in
704 /$udev_root/.udev/ now, there is no longer an option to set this
706 If the init script or something else used this value, just depend on
707 this hardcoded path. But remember _all_content_ of this directory is
708 still private to udev and can change at any time.
710 Default location for rule sripts and helper programs is now: /lib/udev/.
711 Everything that is not useful on the commandline should go into this
712 directory. Some of the helpers in the extras folder are installed there
713 now. The rules need to be changed, to find the helpers there.
715 Also /lib/udev/devices is recommended as a directory where packages or
716 the user can place real device nodes, which get copied over to /dev at
717 every boot. This should replace the various solutions with custom config
720 Udevsend does no longer start the udev daemon. This must be done with
721 the init script that prepares /dev on tmpfs and creates the initial nodes,
722 before starting the daemon.
726 Silent a too verbose error logging for the old hotplug.d/ dev.d/
729 The copy of klibc is removed. A systemwide installed version of klibc
730 should be used to build a klibc udev now.
734 NAME="" will not create any nodes, but execute RUN keys. To completely
735 ignore an event the OPTION "ignore_device" should be used.
737 After removal of the reorder queue, events with a TIMEOUT can be executed
738 without any queuing now.
742 Fixed bug in udevd, if inotify is not available. We depend on netlink
743 uevents now, kernels without that event source will not work with that
744 version of udev anymore.
748 The rule parsing happens now in the daemon once at startup, all udev
749 event processes inherit the already parsed rules from the daemon.
750 It is shipped with SUSE10.0 and reduces heavily the system load at
751 startup. The option to save precompiled rules and let the udev process
752 pick the them up is removed, as it's no longer needed.
754 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
755 device. Libsysfs is changed to "translate" the requested link into the
756 real device path, as it would happen with the hotplug event. Otherwise
757 device removal and the udev database will not work.
759 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
762 A few improvements for vol_id, the filesytem probing code.
766 Fix a stupid typo in extras/run_directory for "make install".
768 scsi_id creates the temporary devnode now in /dev for usage with a
769 non-writable /tmp directory.
771 The uevent kernel socket buffer can carry app. 50.000 events now,
772 let's see who can break this again. :)
774 The upcoming kernel will have a new input driver core integration.
775 Some class devices are now symlinks to the real device. libsysfs
776 needs a fix for this to work correctly. Udevstart of older udev
777 versions will _not_ create these devices!
781 Fix a 'install' target in the Makefile, that prevents EXTRAS from
786 A bunch of mostly trivial bugfixes. From now on no node name or
787 symlink name can contain any character than plain whitelisted ascii
788 characters or validated utf8 byte-streams. This is needed for the
789 /dev/disk/by-label/* links, because we import untrusted data and
790 export it to the filesystem.
794 More bugfixes. If udevd was started from the kernel, we don't
795 have stdin/stdout/stderr, which broke the forked tools in some
800 Bugfix. udevstart event ordering was broken for a long time.
801 The new run_program() uncovered it, because /dev/null was not
802 available while we try to run external programs.
803 Now udevstart should create it before we run anything.
807 Minor bugfixes and some distro rules updates. If you don't have the
808 persistent disk rules in /dev/disk/by-*/* on your distro, just
809 grab it from here. :)
813 We can use socket communication now to pass events from udev to
815 RUN+="socket:/org/freedesktop/hal/udev_event"
816 will pass the whole udev event to the HAL daemon without the need
817 for a forked helper. (See ChangeLog for udevmonitor, as an example)
821 Mostly bugfixes and see ChangeLog.
823 The test for the existence of an environment value should be
825 ENV{KEY}=="*" to ENV{KEY}=="?*"
826 because "*" will not fail anymore, if the key does not exist or
831 Bugfixes and a few tweaks described in the ChangeLog.
835 Mostly a Bugfix release.
837 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
838 timing with custom rules.
842 We changed the internal rule storage format. Our large rule files took
843 2 MB of RAM, with the change we are down to 99kB.
845 If the device-node has been created with default name and no symlink or
846 options are to remenber, it is not longer stored in the udevdb. HAL will
847 need to be updated to work correctly with that change.
849 To overrride optimization flags, OPTFLAGS may be used now.
857 Major changes happened with this release. The goal is to take over the
858 complete kernel-event handling and provide a more efficient way to dispatch
859 kernel events. Replacing most of the current shell script logic and the
860 kernel forked helper with a netlink-daemon and a rule-based event handling.
862 o udevd listens to netlink events now. The first valid netlink event
863 will make udevd ignore any message from udevsend that contains a
864 SEQNUM, to avoid duplicate events. The forked events can be disabled
866 echo "" > /proc/sys/kernel/hotplug
867 For full support, the broken input-subsytem needs to be fixed, not to
868 bypass the driver core.
870 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
871 removed from udev itself and must be emulated by calling small
872 helper binaries provided in the extras folder:
873 make EXTRAS=extras/run_directory/
874 will build udev_run_devd and udev_run_hotplugd, which can be called
875 from a rule if needed:
876 RUN+="/sbin/udev_run_hotplugd"
877 The recommended way to handle this is to convert all the calls from
878 the directories to explicit udev rules and get completely rid of the
879 multiplexing. (To catch a ttyUSB event, you now no longer need to
880 fork and exit 300 tty script instances you are not interested in, it
881 is just one rule that matches exactly the device.)
883 o udev handles now _all_ events not just events for class and block
884 devices, this way it is possible to control the complete event
885 behavior with udev rules. Especially useful for rules like:
886 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
888 o As used in the modalias rule, udev supports now textual
889 substitution placeholder along with the usual format chars. This
890 needs to be documented, for now it's only visible in udev_rules_parse.c.
892 o The rule keys support now more operations. This is documented in the
893 man page. It is possible to add values to list-keys like the SYMLINK
894 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
895 Also "final"-assignments are supported by using KEY:="value", which will
896 prevent changing the key by any later rule.
898 o kernel 2.6.12 has the "detached_state" attribute removed from
899 sysfs, which was used to recognize sysfs population. We switched that
900 to wait for the "bus" link, which is only available in kernels after 2.6.11.
901 Running this udev version on older kernels may cause a short delay for
904 o To provide infrastructure for persistent device naming, the id programs:
905 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
906 to export the probed data in environment key format:
907 pim:~ # /sbin/ata_id --export /dev/hda
908 ID_MODEL=HTS726060M9AT00
909 ID_SERIAL=MRH401M4G6UM9B
913 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
914 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
917 kay@pim:~> tree /dev/disk
920 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
921 | `-- IBM-Memory_Key -> ../../sda
923 | |-- swap -> ../../hda1
924 | |-- date -> ../../sda1
925 | `-- home -> ../../hda3
927 |-- 2E08712B0870F2E7 -> ../../hda3
928 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
929 |-- E845-7A89 -> ../../sda1
930 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
932 The IMPORT= operation will import these keys in the environment and make
933 it available for later PROGRAM= and RUN= executed programs. The keys are
934 also stored in the udevdb and can be queried from there with one of the
937 o A few binaries are silently added to the repository, which can be used
938 to replay kernel events from initramfs instead of using coldplug. udevd
939 can be instructed now to queue-up events while the stored events from
940 initramfs are filled into the udevd-queue. This code is still under
941 development and there is no documentation now besides the code itself.
942 The additional binaries get compiled, but are not installed by default.
944 o There is also a temporary fix for a performance problem where too many
945 events happen in parallel and every event needs to parse the rules.
946 udev can now read precompiled rules stored on disk. This is likely to be
947 replaced by a more elegant solution in a future udev version.
951 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
952 Fix for libsysfs not to expect this file was added.
956 All rules are applied now, but only the first matching rule with a NAME-key
957 will be applied. All later rules with NAME-key are completely ignored. This
958 way system supplied symlinks or permissions gets applied to user-defined
962 Please check your rules setup, if you may need to add OPTIONS="last_rule"
963 to some rules, to keep the old behavior.
965 The rules are read on "remove"-events too. That makes is possible to match
966 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
967 instruct udev to ignore an event (OPTIONS="ignore_device").
968 The new ACTION-key may be used to let a rule act only at a "remove"-event.
970 The new RUN-key supports rule-based execution of programs after device-node
971 handling. This is meant as a general replacement for the dev.d/-directories
972 to give fine grained control over the execution of programs.
974 The %s{}-sysfs format char replacement values are searched at any of the
975 devices in the device chain now, not only at the class-device.
977 We support log priority levels now. The value udev_log in udev.conf is used
978 to determine what is printed to syslog. This makes it possible to
979 run a version with compiled-in debug messages in a production environment
980 which is sometimes needed to find a bug.
981 It is still possible to supress the inclusion of _any_ syslog usage with
982 USE_LOG=false to create the smallest possible binaries if needed.
983 The configured udev_log value can be overridden with the environment variable
988 Possible use of a system-wide klibc:
989 make USE_KLIBC=true KLCC=/usr/bin/klcc all
990 will link against an external klibc and our own version will be ignored.
994 We support an unlimited count of symlinks now.
996 If USE_STATIC=true is passed to a glibc build, we link statically and use
997 a built-in userdb parser to resolve user and group names.
999 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1000 we walk up the chain of physical devices to find a match.
1002 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1003 easy to skip certain attribute matches without composing rules with weird
1004 character class negations like:
1005 KERNEL="[!s][!c][!d]*"
1006 this can now be replaced with:
1008 The current simple '=' is still supported, and should work as it does today,
1009 but existing rules should be converted if possible, to be better readable.
1011 We have new ENV{}== key now, to match against a maximum of 5 environment
1014 udevstart is its own binary again, because we don't need co carry this araound
1015 with every forked event.