3 Bugfixes. (And maybe new bugs. :))
5 The rule matching engine got converted from a rule list to a token
6 array which reduced the in-memory rules representation of a full
7 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
8 Limits like 5 ENV and ATTR matches, and one single instance for most
9 other keys per rule are gone.
11 The NAME assignment is no longer special cased. If later rules assign
12 a NAME value again, the former value will be overwritten. As usual
13 for most other keys, the NAME value can be protected by doing a final
14 assignment with NAME:="<value>".
16 All udev code now uses libudev, which is also exported. The library
17 is still under development, marked as experimental, and its interface
18 may change as long as the DeviceKit integration is not finished.
20 Many thanks to Alan Jenkins for his continuous help, and finding and
21 optimizing some of the computing expensive parts.
27 Kernel devices and device nodes are connected now by reverse indizes in
28 /sys and /dev. A device number retrieved by a stat() or similar, the
29 kernel device directory can be found by looking up:
30 /sys/dev/{block,char}/<maj>:<min>
31 and the device node of the same device by looking up:
32 /dev/{block,char}/<maj>:<min>
36 Fix recently introduced bug, which caused a compilation without large
37 file support, where vol_id does not recognize raid signatures at the end
40 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
41 Seems some kernel versions prevent the creation of the ieee-* links,
42 so people used the scsi-* link which disappeared now.
44 More libudev work. Almost all udevadm functionality comes from libudev
47 udevadm trigger has a new option --type, which allows to trigger events
48 for "devices", for "subsystems", or "failed" devices. The old option
49 --retry-failed" still works, but is no longer mentioned in the man page.
55 The udevadm info --device-id-of-file= output has changed to use
56 the obvious format. Possible current users should use the --export
57 option which is not affected.
59 The old udev commands symlinks to udevadm are not installed, if
60 these symlinks are used, a warning is printed.
66 Optical drive's media is no longer probed for raid signatures,
67 reading the end of the device causes some devices to malfunction.
68 Also the offset of the last session found is used now to probe
71 The volume_id library got a major version number update to 1,
72 some deprecated functions are removed.
74 A shared library "libudev" gets installed now to provide access
75 to udev device information. DeviceKit, the successor of HAL, will
76 need this library to access the udev database and search sysfs for
78 The library is currently in an experimental state, also the API is
79 expected to change, as long as the DeviceKit integration is not
84 We use ./configure now. See INSTALL for details. Current
87 "/usr" - prefix for man pages, include files
89 "" - the root filesystem, prefix for libs and binaries
93 "lib" - directory name for libraries, not a path name
94 multilib 64bit systems may use "lib64" instead of "lib"
96 compile-in verbose debug messages
98 disable all logging and compile-out all log strings
100 link against SELInux libraries, to set the expected context
103 In the default rules, the group "disk" gets permissions 0660 instead
104 of 0640. One small step closer to unify distro rules. Some day, all
105 distros hopefully end up with the same set of rules.
107 No symlinks to udevadm are installed anymore, if they are still needed,
108 they should be provided by the package.
114 Default udev rules, which are not supposed to be edited by the user, should
115 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
116 the udev package and will be replaced with an update. Udev will pick up rule
118 /lib/udev/rules.d/ - default installed rules
119 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
120 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
121 It does not matter in which directory a rule file lives, all files are sorted
124 To help creating /dev/root, we have now:
125 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
128 In case the current --device-id-of-file is already used, please switch to
129 the --export format version, it saves the output parsing and the old
130 format will be changed to use ':' as a separator, like the format in the
135 Fix cdrom_id to properly recognize blank media.
141 Tape drive id-data is queried from /dev/bsg/* instead of the tape
142 nodes. This avoids rewinding tapes on open().
148 The symlinks udevcontrol and udevtrigger are no longer installed by
151 The scsi_id program does not depend on sysfs anymore. It can speak
152 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
153 data, which should solve some old problems with tape devices, where
154 we better do not open all tape device nodes to identify the device.
160 The cdrom_id program is replaced by an advanced version, which can
161 detect most common device types, and also properties of the inserted
162 media. This is part of moving some basic functionality from HAL into
163 udev (and the kernel).
169 The last WAIT_FOR_SYSFS rule is removed from the default rules.
171 The symlinks to udevadm for the debugging tools: udevmonitor and
172 udevtest are no longer created.
174 The symlinks to the udevadm man page for the old tool names are
177 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
178 should be prefixed with '@' to indicate that the path is not a
189 Udevstart is removed from the tree, it did not get installed for
190 a long time now, and is long replaced by trigger and settle.
196 All udev tools are merged into a single binary called udevadm.
197 The old names of the tools are built-in commands in udevadm now.
198 Symlinks to udevadm, with the names of the old tools, provide
199 the same functionality as the standalone tools. There is also
200 only a single udevadm.8 man page left for all tools.
202 Tools like mkinitramfs should be checked, if they need to include
203 udevadm in the list of files.
213 The etc/udev/rules.d/ directory now contains a default set of basic
214 udev rules. This initial version is the result of a rules file merge
215 of Fedora and openSUSE. For these both distros only a few specific
216 rules are left in their own file, named after the distro. Rules which
217 are optionally installed, because they are only valid for a specific
218 architecture, or rules for subsystems which are not always used are
219 in etc/udev/packages/.
225 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
226 actions by dynamically created rules.
228 SYMLINK=="<value>" matches agains the entries in the list of
229 currently defined symlinks. The links are not created in the
230 filesystem at that point in time, but the values can be matched.
232 RUN{ignore_error}+="<program>" will ignore any exit code from the
233 program and not record as a failed event.
239 Final merge of patches/features from the Ubuntu package.
245 Control characters in filesystem label strings are no longer silenty
246 removed, but hex-encoded, to be able to uniquely identify the device
247 by its symlink in /dev/disk/by-label/.
248 If libvolume_id is used by mount(8), LABEL= will work as expected,
249 if slashes or other characters are used in the label string.
251 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
252 can be specified now. The TEST key accepts an optional mode mask
253 TEST{0100}=="<is executable file>".
255 Scsi_id now supports a mode without expecting scsi-specific sysfs
256 entries to allow the extraction of cciss-device persistent properties.
262 In the future, we may see uuid's which are just simple character
263 strings (see the DDF Raid Specification). For that reason vol_id now
264 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
265 the creation of symlinks, the *_SAFE values ensure, that no control
266 or whitespace characters are used in the filename.
268 Possible users of libvolume_id, please use the volume_id_get_* functions.
269 The public struct will go away in a future release of the library.
275 Removal of useless extras/eventrecorder.sh.
285 The directory multiplexer for dev.d/ and hotplug.d are finally removed
286 from the udev package.
292 Symlinks can have priorities now, the priority is assigned to the device
293 and specified with OPTIONS="link_priority=100". Devices with higher
294 priorities overwrite the symlinks of devices with lower priorities.
295 If the device that currently owns the link, goes away, the symlink
296 will be removed, and recreated, pointing to the next device with the
297 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
298 more reliable, if multiple devices contain the same metadata and overwrite
301 The dasd_id program is removed from the udev tree, and dasdinfo, with the
302 needed rules, are part of the s390-tools now.
304 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
305 we may get the scsi sysfs mess fixed some day, and this will only catch
306 the devices we are looking for.
308 USB serial numbers for storage devices have the target:lun now appended,
309 to make it possibble to distinguish broken multi-lun devices with all
310 the same SCSI identifiers.
312 Note: The extra "run_directory" which searches and executes stuff in
313 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
314 with the next release. Make sure, that you don't use it anymore, or
315 provides your own implementation of that inefficient stuff.
316 We are tired of reports about a "slow udev", because these directories
317 contain stuff, that runs with _every_ event, instead of using rules,
318 that run programs only for the matching events.
328 DRIVER== will match only for devices that actually have a real
329 driver. DRIVERS== must be used, if parent devices should be
330 included in the match.
332 Libvolume_id's "linux_raid" detection needed another fix.
340 Add additional check to volume_id detection of via_raid, cause
341 some company decided to put a matching pattern all over the empty
342 storage area of their music players.
346 Fix path_id for SAS devices.
350 The udev daemon can be started with --debug-trace now, which will
351 execute all events serialized to get a chance to catch a possible
352 action that crashes the box.
354 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
355 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
356 are excluded from the warning. Referencing parent attributes directly
357 may break when something in the kernel driver model changes. Udev will
358 just find the attribute by walking up the parent chain.
360 Udevtrigger now sorts the list of devices depending on the device
361 dependency, so a "usb" device is triggered after the parent "pci"
366 Revert persistent-storage ata-serial '_' '-' replacement.
372 Udevtrigger can now filter the list of devices to be triggered. Matches
373 for subsystems or sysfs attributes can be specified.
375 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
376 zero-sized files to avoid pointing to /sys and confuse broken tools which
377 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
380 The rules and scripts to create udev rules for persistent network
381 devices and optical drives are in the extras/rules_generator directory
382 now. If you use something similar, please consider replacing your own
383 version with this, to share the support effort. The rule_generator
384 installs its own rules into /etc/udev/rules.d.
386 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
387 the rule_generator depends on cdrom_id to be called in an earlier rule.
393 Renaming of some key names (the old names still work):
394 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
395 (The behavior of the key DRIVER will change soon in one of the next
396 releases, to match only the event device, please switch to DRIVERS
397 instead. If DRIVER is used, it will behave like DRIVERS, but an error
399 With the new key names, we have a more consistent and simpler scheme.
400 We can match the properties of the event device only, with: KERNEL,
401 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
402 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
403 longer mentioned in the man page and should be switched in the rule
406 ATTR{file}="value" can be used now, to write to a sysfs file of the
407 event device. Instead of:
408 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
410 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
412 All the PHYSDEV* keys are deprecated and will be removed from a
414 PHYDEVPATH - is the path of a parent device and should not be
416 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
417 matched with SUBSYSTEMS==
418 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
419 Newer kernels will have DRIVER in the environment,
420 for older kernels udev puts in. Class device will
421 no longer carry this property of a parent and
422 DRIVERS== can be used to match such a parent value.
423 Note that ENV{DRIVER} is only available for a few bus devices, where
424 the driver is already bound at device event time. On coldplug, the
425 events for a lot devices are already bound to a driver, and they will have
426 that value set. But on hotplug, at the time the kernel creates the device,
427 it can't know what driver may claim the device after that, therefore
428 in most cases it will be empty.
430 Failed events should now be re-triggered with:
431 udevtrigger --retry-failed.
432 Please switch to this command, so we keep the details of the /dev/.udev/failed/
433 files private to the udev tools. We may need to switch the current symlink
434 target, cause some obviously broken tools try to scan all files in /dev
435 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
436 million times. This takes ages on slow boxes.
438 The udevinfo attribute walk (-a) now works with giving a device node
439 name (-n) instead of a devpath (-p). The query now always works, also when
440 no database file was created by udev.
442 The built-in /etc/passwd /etc/group parser is removed, we always depend on
443 getpwnam() and getgrnam() now. One of the next releases will depend on
444 fnmatch() and may use getopt_long().
448 Bugfixes and small improvements.
452 Fix path_id for recent kernels.
458 Added support for swapping network interface names, by temporarily
459 renaming the device and wait for the target name to become free.
463 The built-in MODALIAS key and substitution is removed.
467 The binary firmware helper is replaced by the usual simple
468 shell script. Udevsend is removed from the tree.
476 Some more keys require the correct use of '==' and '=' depending
477 on the kind of operation beeing an assignment or a match. Rules
478 with invalid operations are skipped and logged to syslog. Please
479 test with udevtest if the parsing of your rules throws errors and
480 fix possibly broken rules.
484 Provide "udevsettle" to wait for all current udev events to finish.
485 It also watches the current kernel netlink queue by comparing the
486 even sequence number to make sure that there are no current pending
487 events that have not already arrived in the daemon.
491 Fix rule to skip persistent rules for removable IDE devices, which
492 also skipped optical IDE drives.
494 All *_id program are installed in /lib/udev/ by default now.
496 No binary is stripped anymore as this should be done in the
497 packaging process and not at build time.
499 libvolume_id is provided as a shared library now and vol_id is
500 linked against it. Also one of the next HAL versions will require
501 this library, and the HAL build process will also require the
502 header file to be installed. The copy of the same code in HAL will
503 be removed to have only a single copy left on the system.
507 Add persistent links for SCSI tapes. The rules file is renamed
508 to 60-persistent-storage.rules.
510 Create persistent path for usb devices. Can be used for all sorts
511 of devices that can't be distinguished by other properties like
512 multiple identical keyboards and mice connected to the same box.
514 Provide "udevtrigger" program to request events on coldplug. The
515 shell script is much too slow with thousends of devices.
519 Fix persistent disk rules to exclude removable IDE drives.
521 Warn if %e, $modalias or MODALIAS is used.
525 Fix queue export, which wasn't correct for subsequent add/remove
526 events for the same device.
530 Fix cramfs detection on big endian.
532 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
537 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
538 attributes were only checked at the parent device that matched the
539 by BUS requested subsystem. Fix it to also look at the device we
540 received the event for.
542 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
547 Fix a bug where NAME="" would prevent RUN from beeing executed.
549 RUN="/bin/program" does not longer automatically add the subsystem
550 as the first parameter. This is from the days of /sbin/hotplug
551 which is dead now and it's just confusing to need to add a space at
552 the end of the program name to prevent this.
553 If you use rules that need the subsystem as the first parameter,
554 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
555 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
559 The udev man page has moved to udev(7) as it does not describe a command
560 anymore. The programs udev, udevstart and udevsend are no longer installed
561 by default and must be copied manually, if they should be installed or
562 included in a package.
564 Fix a bug where "ignore_device" could run earlier collected RUN keys before
565 the ignore rule was applied.
567 More preparation for future sysfs changes. usb_id and scsi_id no longer
568 depend on a magic order of devices in the /devices chain. Specific devices
569 should be requested by their subsytem.
571 This will always find the scsi parent device without depending on a specific
573 dev = sysfs_device_get(devpath);
574 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
576 The "device" link in the current sysfs layout will be automatically
577 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
578 parent in the devpath. If a device is requested by it's symlink, like all
579 class devices in the new sysfs layout will look like, it gets automatically
580 resolved and substituted with the real devpath and not the symlink path.
583 A similar logic must be applied to _all_ sysfs users, including
584 scripts, that search along parent devices in sysfs. The explicit use of
585 the "device" link must be avoided. With the future sysfs layout all
586 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
587 back to the "class" or the "bus". The layout of the parent devices in
588 /devices is not necessarily expected to be stable across kernel releases and
589 searching for parents by their subsystem should make sysfs users tolerant
590 for changed parent chains.
594 Prepare udev to work with the experimental kernel patch, that moves
595 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
597 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
598 moving the class devices to /sys/devices.
600 Thanks again to Marco for help finding a hopefully nice compromise
601 to make %b simpler and working again.
605 Complete removal of libsysfs, replaced by simple helper functions
606 which are much simpler and a bit faster. The udev daemon operatesentirely
607 on event parameters and does not use sysfs for simple rules anymore.
608 Please report any new bugs/problems, that may be caused by this big
609 change. They will be fixed immediately.
611 The enumeration format character '%e' is deprecated and will be
612 removed sometimes from a future udev version. It never worked correctly
613 outside of udevstart, so we can't use it with the new parallel
614 coldplug. A simple enumeration is as useless as the devfs naming
615 scheme, just get rid of both if you still use it.
617 MODALIAS and $modalias is not needed and will be removed from one of
618 the next udev versions, replace it in all rules with ENV{MODALIAS} or
619 the sysfs "modalias" value.
621 Thanks a lot to Marco for all his help on finding and fixing bugs.
625 Let scsi_id request libata drive serial numbers from page 0x80.
627 Renamed etc/udev/persistent.rules to persistent-disk.rules and
628 added /dev/disk/by-name/* for device mapper device names.
630 Removed %e from the man page. It never worked reliably outside
631 of udevstart and udevstart is no longer recommended to use.
635 Symlinks are now exported to the event environment. Hopefully it's no
636 longer needed to run udevinfo from an event process, like it was
637 mentioned on the hotplug list:
638 UDEV [1134776873.702967] add@/block/sdb
641 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
645 Fix a problem if udevsend is used as the hotplug handler and tries to use
646 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
647 and this kind of problems will hopefully go away soon.
651 All built-in logic to work around bad sysfs timing is removed with this
652 version. The need to wait for sysfs files is almost fixed with a kernel
653 version that doesn't work with this udev version anyway. Until we fix
654 the timing of the "bus" link creation, the former integrated logic should
655 be emulated by a rule placed before all other rules:
656 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
658 The option "udev_db" does no longer exist. All udev state will be in
659 /$udev_root/.udev/ now, there is no longer an option to set this
661 If the init script or something else used this value, just depend on
662 this hardcoded path. But remember _all_content_ of this directory is
663 still private to udev and can change at any time.
665 Default location for rule sripts and helper programs is now: /lib/udev/.
666 Everything that is not useful on the commandline should go into this
667 directory. Some of the helpers in the extras folder are installed there
668 now. The rules need to be changed, to find the helpers there.
670 Also /lib/udev/devices is recommended as a directory where packages or
671 the user can place real device nodes, which get copied over to /dev at
672 every boot. This should replace the various solutions with custom config
675 Udevsend does no longer start the udev daemon. This must be done with
676 the init script that prepares /dev on tmpfs and creates the initial nodes,
677 before starting the daemon.
681 Silent a too verbose error logging for the old hotplug.d/ dev.d/
684 The copy of klibc is removed. A systemwide installed version of klibc
685 should be used to build a klibc udev now.
689 NAME="" will not create any nodes, but execute RUN keys. To completely
690 ignore an event the OPTION "ignore_device" should be used.
692 After removal of the reorder queue, events with a TIMEOUT can be executed
693 without any queuing now.
697 Fixed bug in udevd, if inotify is not available. We depend on netlink
698 uevents now, kernels without that event source will not work with that
699 version of udev anymore.
703 The rule parsing happens now in the daemon once at startup, all udev
704 event processes inherit the already parsed rules from the daemon.
705 It is shipped with SUSE10.0 and reduces heavily the system load at
706 startup. The option to save precompiled rules and let the udev process
707 pick the them up is removed, as it's no longer needed.
709 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
710 device. Libsysfs is changed to "translate" the requested link into the
711 real device path, as it would happen with the hotplug event. Otherwise
712 device removal and the udev database will not work.
714 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
717 A few improvements for vol_id, the filesytem probing code.
721 Fix a stupid typo in extras/run_directory for "make install".
723 scsi_id creates the temporary devnode now in /dev for usage with a
724 non-writable /tmp directory.
726 The uevent kernel socket buffer can carry app. 50.000 events now,
727 let's see who can break this again. :)
729 The upcoming kernel will have a new input driver core integration.
730 Some class devices are now symlinks to the real device. libsysfs
731 needs a fix for this to work correctly. Udevstart of older udev
732 versions will _not_ create these devices!
736 Fix a 'install' target in the Makefile, that prevents EXTRAS from
741 A bunch of mostly trivial bugfixes. From now on no node name or
742 symlink name can contain any character than plain whitelisted ascii
743 characters or validated utf8 byte-streams. This is needed for the
744 /dev/disk/by-label/* links, because we import untrusted data and
745 export it to the filesystem.
749 More bugfixes. If udevd was started from the kernel, we don't
750 have stdin/stdout/stderr, which broke the forked tools in some
755 Bugfix. udevstart event ordering was broken for a long time.
756 The new run_program() uncovered it, because /dev/null was not
757 available while we try to run external programs.
758 Now udevstart should create it before we run anything.
762 Minor bugfixes and some distro rules updates. If you don't have the
763 persistent disk rules in /dev/disk/by-*/* on your distro, just
764 grab it from here. :)
768 We can use socket communication now to pass events from udev to
770 RUN+="socket:/org/freedesktop/hal/udev_event"
771 will pass the whole udev event to the HAL daemon without the need
772 for a forked helper. (See ChangeLog for udevmonitor, as an example)
776 Mostly bugfixes and see ChangeLog.
778 The test for the existence of an environment value should be
780 ENV{KEY}=="*" to ENV{KEY}=="?*"
781 because "*" will not fail anymore, if the key does not exist or
786 Bugfixes and a few tweaks described in the ChangeLog.
790 Mostly a Bugfix release.
792 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
793 timing with custom rules.
797 We changed the internal rule storage format. Our large rule files took
798 2 MB of RAM, with the change we are down to 99kB.
800 If the device-node has been created with default name and no symlink or
801 options are to remenber, it is not longer stored in the udevdb. HAL will
802 need to be updated to work correctly with that change.
804 To overrride optimization flags, OPTFLAGS may be used now.
812 Major changes happened with this release. The goal is to take over the
813 complete kernel-event handling and provide a more efficient way to dispatch
814 kernel events. Replacing most of the current shell script logic and the
815 kernel forked helper with a netlink-daemon and a rule-based event handling.
817 o udevd listens to netlink events now. The first valid netlink event
818 will make udevd ignore any message from udevsend that contains a
819 SEQNUM, to avoid duplicate events. The forked events can be disabled
821 echo "" > /proc/sys/kernel/hotplug
822 For full support, the broken input-subsytem needs to be fixed, not to
823 bypass the driver core.
825 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
826 removed from udev itself and must be emulated by calling small
827 helper binaries provided in the extras folder:
828 make EXTRAS=extras/run_directory/
829 will build udev_run_devd and udev_run_hotplugd, which can be called
830 from a rule if needed:
831 RUN+="/sbin/udev_run_hotplugd"
832 The recommended way to handle this is to convert all the calls from
833 the directories to explicit udev rules and get completely rid of the
834 multiplexing. (To catch a ttyUSB event, you now no longer need to
835 fork and exit 300 tty script instances you are not interested in, it
836 is just one rule that matches exactly the device.)
838 o udev handles now _all_ events not just events for class and block
839 devices, this way it is possible to control the complete event
840 behavior with udev rules. Especially useful for rules like:
841 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
843 o As used in the modalias rule, udev supports now textual
844 substitution placeholder along with the usual format chars. This
845 needs to be documented, for now it's only visible in udev_rules_parse.c.
847 o The rule keys support now more operations. This is documented in the
848 man page. It is possible to add values to list-keys like the SYMLINK
849 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
850 Also "final"-assignments are supported by using KEY:="value", which will
851 prevent changing the key by any later rule.
853 o kernel 2.6.12 has the "detached_state" attribute removed from
854 sysfs, which was used to recognize sysfs population. We switched that
855 to wait for the "bus" link, which is only available in kernels after 2.6.11.
856 Running this udev version on older kernels may cause a short delay for
859 o To provide infrastructure for persistent device naming, the id programs:
860 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
861 to export the probed data in environment key format:
862 pim:~ # /sbin/ata_id --export /dev/hda
863 ID_MODEL=HTS726060M9AT00
864 ID_SERIAL=MRH401M4G6UM9B
868 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
869 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
872 kay@pim:~> tree /dev/disk
875 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
876 | `-- IBM-Memory_Key -> ../../sda
878 | |-- swap -> ../../hda1
879 | |-- date -> ../../sda1
880 | `-- home -> ../../hda3
882 |-- 2E08712B0870F2E7 -> ../../hda3
883 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
884 |-- E845-7A89 -> ../../sda1
885 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
887 The IMPORT= operation will import these keys in the environment and make
888 it available for later PROGRAM= and RUN= executed programs. The keys are
889 also stored in the udevdb and can be queried from there with one of the
892 o A few binaries are silently added to the repository, which can be used
893 to replay kernel events from initramfs instead of using coldplug. udevd
894 can be instructed now to queue-up events while the stored events from
895 initramfs are filled into the udevd-queue. This code is still under
896 development and there is no documentation now besides the code itself.
897 The additional binaries get compiled, but are not installed by default.
899 o There is also a temporary fix for a performance problem where too many
900 events happen in parallel and every event needs to parse the rules.
901 udev can now read precompiled rules stored on disk. This is likely to be
902 replaced by a more elegant solution in a future udev version.
906 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
907 Fix for libsysfs not to expect this file was added.
911 All rules are applied now, but only the first matching rule with a NAME-key
912 will be applied. All later rules with NAME-key are completely ignored. This
913 way system supplied symlinks or permissions gets applied to user-defined
917 Please check your rules setup, if you may need to add OPTIONS="last_rule"
918 to some rules, to keep the old behavior.
920 The rules are read on "remove"-events too. That makes is possible to match
921 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
922 instruct udev to ignore an event (OPTIONS="ignore_device").
923 The new ACTION-key may be used to let a rule act only at a "remove"-event.
925 The new RUN-key supports rule-based execution of programs after device-node
926 handling. This is meant as a general replacement for the dev.d/-directories
927 to give fine grained control over the execution of programs.
929 The %s{}-sysfs format char replacement values are searched at any of the
930 devices in the device chain now, not only at the class-device.
932 We support log priority levels now. The value udev_log in udev.conf is used
933 to determine what is printed to syslog. This makes it possible to
934 run a version with compiled-in debug messages in a production environment
935 which is sometimes needed to find a bug.
936 It is still possible to supress the inclusion of _any_ syslog usage with
937 USE_LOG=false to create the smallest possible binaries if needed.
938 The configured udev_log value can be overridden with the environment variable
943 Possible use of a system-wide klibc:
944 make USE_KLIBC=true KLCC=/usr/bin/klcc all
945 will link against an external klibc and our own version will be ignored.
949 We support an unlimited count of symlinks now.
951 If USE_STATIC=true is passed to a glibc build, we link statically and use
952 a built-in userdb parser to resolve user and group names.
954 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
955 we walk up the chain of physical devices to find a match.
957 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
958 easy to skip certain attribute matches without composing rules with weird
959 character class negations like:
960 KERNEL="[!s][!c][!d]*"
961 this can now be replaced with:
963 The current simple '=' is still supported, and should work as it does today,
964 but existing rules should be converted if possible, to be better readable.
966 We have new ENV{}== key now, to match against a maximum of 5 environment
969 udevstart is its own binary again, because we don't need co carry this araound
970 with every forked event.
~ianmdlvl / elogind.git / blob