5 Fix for a possible segfault while swapping network interface names in udev
12 The group "video" is part of the default rules now.
16 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
17 block devices in some cases. No common distro uses this option anymore,
18 and we do not get enough testing for this and recent udev versions. If
19 this option is not needed to run some old distro with a new kernel,
20 it should be disabled in the kernel config.
22 Bugfix for the $links substitution variable, which may crash if no links
23 are created. This should not happen in usual setups because we always
24 create /dev/{block,char}/ links.
26 The strings of the parsed rules, which are kept in memory, no longer
27 contain duplicate entries, or duplicate tails of strings. This, and the
28 new rules parsing/matching code reduces the total in-memory size of
29 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
32 The export of DEVTYPE=disk/partition got removed from the default
33 rules. This value is available from the kernel. The pnp shell script
34 modprobe hack is removed from the default rules. ACPI devices have _proper_
35 modalias support and take care of the same functionality.
36 Installations which support old kernels, but install current default
37 udev rules may want to add that to the compat rules file.
39 Libvolume_id now always probes for all known filesystems, and does not
40 stop at the first match. Some filesystems are marked as "exclusive probe",
41 and if any other filesytem type matches at the same time, libvolume_id
42 will, by default, not return any probing result. This is intended to prevent
43 mis-detection with conflicting left-over signatures found from earlier
44 file system formats. That way, we no longer depend on the probe-order
45 in case of multiple competing signatures. In some setups the kernel allows
46 to mount a volume with just the old filesystem signature still in place.
47 This may damage the new filesystem and cause data-loss, just by mounting
48 it. Because volume_id can not decide which one the correct signature is,
49 the wrong signatures need to be removed manually from the volume, or the
50 volume needs to be reformatted, to enable filesystem detection and possible
55 Fix segfault if compiled without optimization and dbg() does not get
56 compiled out and uses variables which are not available.
60 Bugfixes. (And maybe new bugs. :))
62 The rule matching engine got converted from a rule list to a token
63 array which reduced the in-memory rules representation of a full
64 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
65 Limits like 5 ENV and ATTR matches, and one single instance for most
66 other keys per rule are gone.
68 The NAME assignment is no longer special cased. If later rules assign
69 a NAME value again, the former value will be overwritten. As usual
70 for most other keys, the NAME value can be protected by doing a final
71 assignment with NAME:="<value>".
73 All udev code now uses libudev, which is also exported. The library
74 is still under development, marked as experimental, and its interface
75 may change as long as the DeviceKit integration is not finished.
77 Many thanks to Alan Jenkins for his continuous help, and finding and
78 optimizing some of the computing expensive parts.
84 Kernel devices and device nodes are connected now by reverse indizes in
85 /sys and /dev. A device number retrieved by a stat() or similar, the
86 kernel device directory can be found by looking up:
87 /sys/dev/{block,char}/<maj>:<min>
88 and the device node of the same device by looking up:
89 /dev/{block,char}/<maj>:<min>
93 Fix recently introduced bug, which caused a compilation without large
94 file support, where vol_id does not recognize raid signatures at the end
97 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
98 Seems some kernel versions prevent the creation of the ieee-* links,
99 so people used the scsi-* link which disappeared now.
101 More libudev work. Almost all udevadm functionality comes from libudev
104 udevadm trigger has a new option --type, which allows to trigger events
105 for "devices", for "subsystems", or "failed" devices. The old option
106 --retry-failed" still works, but is no longer mentioned in the man page.
112 The udevadm info --device-id-of-file= output has changed to use
113 the obvious format. Possible current users should use the --export
114 option which is not affected.
116 The old udev commands symlinks to udevadm are not installed, if
117 these symlinks are used, a warning is printed.
123 Optical drive's media is no longer probed for raid signatures,
124 reading the end of the device causes some devices to malfunction.
125 Also the offset of the last session found is used now to probe
128 The volume_id library got a major version number update to 1,
129 some deprecated functions are removed.
131 A shared library "libudev" gets installed now to provide access
132 to udev device information. DeviceKit, the successor of HAL, will
133 need this library to access the udev database and search sysfs for
135 The library is currently in an experimental state, also the API is
136 expected to change, as long as the DeviceKit integration is not
141 We use ./configure now. See INSTALL for details. Current
144 "/usr" - prefix for man pages, include files
146 "" - the root filesystem, prefix for libs and binaries
150 "lib" - directory name for libraries, not a path name
151 multilib 64bit systems may use "lib64" instead of "lib"
153 compile-in verbose debug messages
155 disable all logging and compile-out all log strings
157 link against SELInux libraries, to set the expected context
160 In the default rules, the group "disk" gets permissions 0660 instead
161 of 0640. One small step closer to unify distro rules. Some day, all
162 distros hopefully end up with the same set of rules.
164 No symlinks to udevadm are installed anymore, if they are still needed,
165 they should be provided by the package.
171 Default udev rules, which are not supposed to be edited by the user, should
172 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
173 the udev package and will be replaced with an update. Udev will pick up rule
175 /lib/udev/rules.d/ - default installed rules
176 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
177 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
178 It does not matter in which directory a rule file lives, all files are sorted
181 To help creating /dev/root, we have now:
182 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
185 In case the current --device-id-of-file is already used, please switch to
186 the --export format version, it saves the output parsing and the old
187 format will be changed to use ':' as a separator, like the format in the
192 Fix cdrom_id to properly recognize blank media.
198 Tape drive id-data is queried from /dev/bsg/* instead of the tape
199 nodes. This avoids rewinding tapes on open().
205 The symlinks udevcontrol and udevtrigger are no longer installed by
208 The scsi_id program does not depend on sysfs anymore. It can speak
209 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
210 data, which should solve some old problems with tape devices, where
211 we better do not open all tape device nodes to identify the device.
217 The cdrom_id program is replaced by an advanced version, which can
218 detect most common device types, and also properties of the inserted
219 media. This is part of moving some basic functionality from HAL into
220 udev (and the kernel).
226 The last WAIT_FOR_SYSFS rule is removed from the default rules.
228 The symlinks to udevadm for the debugging tools: udevmonitor and
229 udevtest are no longer created.
231 The symlinks to the udevadm man page for the old tool names are
234 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
235 should be prefixed with '@' to indicate that the path is not a
246 Udevstart is removed from the tree, it did not get installed for
247 a long time now, and is long replaced by trigger and settle.
253 All udev tools are merged into a single binary called udevadm.
254 The old names of the tools are built-in commands in udevadm now.
255 Symlinks to udevadm, with the names of the old tools, provide
256 the same functionality as the standalone tools. There is also
257 only a single udevadm.8 man page left for all tools.
259 Tools like mkinitramfs should be checked, if they need to include
260 udevadm in the list of files.
270 The etc/udev/rules.d/ directory now contains a default set of basic
271 udev rules. This initial version is the result of a rules file merge
272 of Fedora and openSUSE. For these both distros only a few specific
273 rules are left in their own file, named after the distro. Rules which
274 are optionally installed, because they are only valid for a specific
275 architecture, or rules for subsystems which are not always used are
276 in etc/udev/packages/.
282 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
283 actions by dynamically created rules.
285 SYMLINK=="<value>" matches agains the entries in the list of
286 currently defined symlinks. The links are not created in the
287 filesystem at that point in time, but the values can be matched.
289 RUN{ignore_error}+="<program>" will ignore any exit code from the
290 program and not record as a failed event.
296 Final merge of patches/features from the Ubuntu package.
302 Control characters in filesystem label strings are no longer silenty
303 removed, but hex-encoded, to be able to uniquely identify the device
304 by its symlink in /dev/disk/by-label/.
305 If libvolume_id is used by mount(8), LABEL= will work as expected,
306 if slashes or other characters are used in the label string.
308 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
309 can be specified now. The TEST key accepts an optional mode mask
310 TEST{0100}=="<is executable file>".
312 Scsi_id now supports a mode without expecting scsi-specific sysfs
313 entries to allow the extraction of cciss-device persistent properties.
319 In the future, we may see uuid's which are just simple character
320 strings (see the DDF Raid Specification). For that reason vol_id now
321 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
322 the creation of symlinks, the *_SAFE values ensure, that no control
323 or whitespace characters are used in the filename.
325 Possible users of libvolume_id, please use the volume_id_get_* functions.
326 The public struct will go away in a future release of the library.
332 Removal of useless extras/eventrecorder.sh.
342 The directory multiplexer for dev.d/ and hotplug.d are finally removed
343 from the udev package.
349 Symlinks can have priorities now, the priority is assigned to the device
350 and specified with OPTIONS="link_priority=100". Devices with higher
351 priorities overwrite the symlinks of devices with lower priorities.
352 If the device that currently owns the link, goes away, the symlink
353 will be removed, and recreated, pointing to the next device with the
354 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
355 more reliable, if multiple devices contain the same metadata and overwrite
358 The dasd_id program is removed from the udev tree, and dasdinfo, with the
359 needed rules, are part of the s390-tools now.
361 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
362 we may get the scsi sysfs mess fixed some day, and this will only catch
363 the devices we are looking for.
365 USB serial numbers for storage devices have the target:lun now appended,
366 to make it possibble to distinguish broken multi-lun devices with all
367 the same SCSI identifiers.
369 Note: The extra "run_directory" which searches and executes stuff in
370 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
371 with the next release. Make sure, that you don't use it anymore, or
372 provides your own implementation of that inefficient stuff.
373 We are tired of reports about a "slow udev", because these directories
374 contain stuff, that runs with _every_ event, instead of using rules,
375 that run programs only for the matching events.
385 DRIVER== will match only for devices that actually have a real
386 driver. DRIVERS== must be used, if parent devices should be
387 included in the match.
389 Libvolume_id's "linux_raid" detection needed another fix.
397 Add additional check to volume_id detection of via_raid, cause
398 some company decided to put a matching pattern all over the empty
399 storage area of their music players.
403 Fix path_id for SAS devices.
407 The udev daemon can be started with --debug-trace now, which will
408 execute all events serialized to get a chance to catch a possible
409 action that crashes the box.
411 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
412 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
413 are excluded from the warning. Referencing parent attributes directly
414 may break when something in the kernel driver model changes. Udev will
415 just find the attribute by walking up the parent chain.
417 Udevtrigger now sorts the list of devices depending on the device
418 dependency, so a "usb" device is triggered after the parent "pci"
423 Revert persistent-storage ata-serial '_' '-' replacement.
429 Udevtrigger can now filter the list of devices to be triggered. Matches
430 for subsystems or sysfs attributes can be specified.
432 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
433 zero-sized files to avoid pointing to /sys and confuse broken tools which
434 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
437 The rules and scripts to create udev rules for persistent network
438 devices and optical drives are in the extras/rules_generator directory
439 now. If you use something similar, please consider replacing your own
440 version with this, to share the support effort. The rule_generator
441 installs its own rules into /etc/udev/rules.d.
443 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
444 the rule_generator depends on cdrom_id to be called in an earlier rule.
450 Renaming of some key names (the old names still work):
451 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
452 (The behavior of the key DRIVER will change soon in one of the next
453 releases, to match only the event device, please switch to DRIVERS
454 instead. If DRIVER is used, it will behave like DRIVERS, but an error
456 With the new key names, we have a more consistent and simpler scheme.
457 We can match the properties of the event device only, with: KERNEL,
458 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
459 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
460 longer mentioned in the man page and should be switched in the rule
463 ATTR{file}="value" can be used now, to write to a sysfs file of the
464 event device. Instead of:
465 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
467 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
469 All the PHYSDEV* keys are deprecated and will be removed from a
471 PHYDEVPATH - is the path of a parent device and should not be
473 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
474 matched with SUBSYSTEMS==
475 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
476 Newer kernels will have DRIVER in the environment,
477 for older kernels udev puts in. Class device will
478 no longer carry this property of a parent and
479 DRIVERS== can be used to match such a parent value.
480 Note that ENV{DRIVER} is only available for a few bus devices, where
481 the driver is already bound at device event time. On coldplug, the
482 events for a lot devices are already bound to a driver, and they will have
483 that value set. But on hotplug, at the time the kernel creates the device,
484 it can't know what driver may claim the device after that, therefore
485 in most cases it will be empty.
487 Failed events should now be re-triggered with:
488 udevtrigger --retry-failed.
489 Please switch to this command, so we keep the details of the /dev/.udev/failed/
490 files private to the udev tools. We may need to switch the current symlink
491 target, cause some obviously broken tools try to scan all files in /dev
492 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
493 million times. This takes ages on slow boxes.
495 The udevinfo attribute walk (-a) now works with giving a device node
496 name (-n) instead of a devpath (-p). The query now always works, also when
497 no database file was created by udev.
499 The built-in /etc/passwd /etc/group parser is removed, we always depend on
500 getpwnam() and getgrnam() now. One of the next releases will depend on
501 fnmatch() and may use getopt_long().
505 Bugfixes and small improvements.
509 Fix path_id for recent kernels.
515 Added support for swapping network interface names, by temporarily
516 renaming the device and wait for the target name to become free.
520 The built-in MODALIAS key and substitution is removed.
524 The binary firmware helper is replaced by the usual simple
525 shell script. Udevsend is removed from the tree.
533 Some more keys require the correct use of '==' and '=' depending
534 on the kind of operation beeing an assignment or a match. Rules
535 with invalid operations are skipped and logged to syslog. Please
536 test with udevtest if the parsing of your rules throws errors and
537 fix possibly broken rules.
541 Provide "udevsettle" to wait for all current udev events to finish.
542 It also watches the current kernel netlink queue by comparing the
543 even sequence number to make sure that there are no current pending
544 events that have not already arrived in the daemon.
548 Fix rule to skip persistent rules for removable IDE devices, which
549 also skipped optical IDE drives.
551 All *_id program are installed in /lib/udev/ by default now.
553 No binary is stripped anymore as this should be done in the
554 packaging process and not at build time.
556 libvolume_id is provided as a shared library now and vol_id is
557 linked against it. Also one of the next HAL versions will require
558 this library, and the HAL build process will also require the
559 header file to be installed. The copy of the same code in HAL will
560 be removed to have only a single copy left on the system.
564 Add persistent links for SCSI tapes. The rules file is renamed
565 to 60-persistent-storage.rules.
567 Create persistent path for usb devices. Can be used for all sorts
568 of devices that can't be distinguished by other properties like
569 multiple identical keyboards and mice connected to the same box.
571 Provide "udevtrigger" program to request events on coldplug. The
572 shell script is much too slow with thousends of devices.
576 Fix persistent disk rules to exclude removable IDE drives.
578 Warn if %e, $modalias or MODALIAS is used.
582 Fix queue export, which wasn't correct for subsequent add/remove
583 events for the same device.
587 Fix cramfs detection on big endian.
589 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
594 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
595 attributes were only checked at the parent device that matched the
596 by BUS requested subsystem. Fix it to also look at the device we
597 received the event for.
599 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
604 Fix a bug where NAME="" would prevent RUN from beeing executed.
606 RUN="/bin/program" does not longer automatically add the subsystem
607 as the first parameter. This is from the days of /sbin/hotplug
608 which is dead now and it's just confusing to need to add a space at
609 the end of the program name to prevent this.
610 If you use rules that need the subsystem as the first parameter,
611 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
612 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
616 The udev man page has moved to udev(7) as it does not describe a command
617 anymore. The programs udev, udevstart and udevsend are no longer installed
618 by default and must be copied manually, if they should be installed or
619 included in a package.
621 Fix a bug where "ignore_device" could run earlier collected RUN keys before
622 the ignore rule was applied.
624 More preparation for future sysfs changes. usb_id and scsi_id no longer
625 depend on a magic order of devices in the /devices chain. Specific devices
626 should be requested by their subsytem.
628 This will always find the scsi parent device without depending on a specific
630 dev = sysfs_device_get(devpath);
631 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
633 The "device" link in the current sysfs layout will be automatically
634 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
635 parent in the devpath. If a device is requested by it's symlink, like all
636 class devices in the new sysfs layout will look like, it gets automatically
637 resolved and substituted with the real devpath and not the symlink path.
640 A similar logic must be applied to _all_ sysfs users, including
641 scripts, that search along parent devices in sysfs. The explicit use of
642 the "device" link must be avoided. With the future sysfs layout all
643 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
644 back to the "class" or the "bus". The layout of the parent devices in
645 /devices is not necessarily expected to be stable across kernel releases and
646 searching for parents by their subsystem should make sysfs users tolerant
647 for changed parent chains.
651 Prepare udev to work with the experimental kernel patch, that moves
652 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
654 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
655 moving the class devices to /sys/devices.
657 Thanks again to Marco for help finding a hopefully nice compromise
658 to make %b simpler and working again.
662 Complete removal of libsysfs, replaced by simple helper functions
663 which are much simpler and a bit faster. The udev daemon operatesentirely
664 on event parameters and does not use sysfs for simple rules anymore.
665 Please report any new bugs/problems, that may be caused by this big
666 change. They will be fixed immediately.
668 The enumeration format character '%e' is deprecated and will be
669 removed sometimes from a future udev version. It never worked correctly
670 outside of udevstart, so we can't use it with the new parallel
671 coldplug. A simple enumeration is as useless as the devfs naming
672 scheme, just get rid of both if you still use it.
674 MODALIAS and $modalias is not needed and will be removed from one of
675 the next udev versions, replace it in all rules with ENV{MODALIAS} or
676 the sysfs "modalias" value.
678 Thanks a lot to Marco for all his help on finding and fixing bugs.
682 Let scsi_id request libata drive serial numbers from page 0x80.
684 Renamed etc/udev/persistent.rules to persistent-disk.rules and
685 added /dev/disk/by-name/* for device mapper device names.
687 Removed %e from the man page. It never worked reliably outside
688 of udevstart and udevstart is no longer recommended to use.
692 Symlinks are now exported to the event environment. Hopefully it's no
693 longer needed to run udevinfo from an event process, like it was
694 mentioned on the hotplug list:
695 UDEV [1134776873.702967] add@/block/sdb
698 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
702 Fix a problem if udevsend is used as the hotplug handler and tries to use
703 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
704 and this kind of problems will hopefully go away soon.
708 All built-in logic to work around bad sysfs timing is removed with this
709 version. The need to wait for sysfs files is almost fixed with a kernel
710 version that doesn't work with this udev version anyway. Until we fix
711 the timing of the "bus" link creation, the former integrated logic should
712 be emulated by a rule placed before all other rules:
713 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
715 The option "udev_db" does no longer exist. All udev state will be in
716 /$udev_root/.udev/ now, there is no longer an option to set this
718 If the init script or something else used this value, just depend on
719 this hardcoded path. But remember _all_content_ of this directory is
720 still private to udev and can change at any time.
722 Default location for rule sripts and helper programs is now: /lib/udev/.
723 Everything that is not useful on the commandline should go into this
724 directory. Some of the helpers in the extras folder are installed there
725 now. The rules need to be changed, to find the helpers there.
727 Also /lib/udev/devices is recommended as a directory where packages or
728 the user can place real device nodes, which get copied over to /dev at
729 every boot. This should replace the various solutions with custom config
732 Udevsend does no longer start the udev daemon. This must be done with
733 the init script that prepares /dev on tmpfs and creates the initial nodes,
734 before starting the daemon.
738 Silent a too verbose error logging for the old hotplug.d/ dev.d/
741 The copy of klibc is removed. A systemwide installed version of klibc
742 should be used to build a klibc udev now.
746 NAME="" will not create any nodes, but execute RUN keys. To completely
747 ignore an event the OPTION "ignore_device" should be used.
749 After removal of the reorder queue, events with a TIMEOUT can be executed
750 without any queuing now.
754 Fixed bug in udevd, if inotify is not available. We depend on netlink
755 uevents now, kernels without that event source will not work with that
756 version of udev anymore.
760 The rule parsing happens now in the daemon once at startup, all udev
761 event processes inherit the already parsed rules from the daemon.
762 It is shipped with SUSE10.0 and reduces heavily the system load at
763 startup. The option to save precompiled rules and let the udev process
764 pick the them up is removed, as it's no longer needed.
766 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
767 device. Libsysfs is changed to "translate" the requested link into the
768 real device path, as it would happen with the hotplug event. Otherwise
769 device removal and the udev database will not work.
771 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
774 A few improvements for vol_id, the filesytem probing code.
778 Fix a stupid typo in extras/run_directory for "make install".
780 scsi_id creates the temporary devnode now in /dev for usage with a
781 non-writable /tmp directory.
783 The uevent kernel socket buffer can carry app. 50.000 events now,
784 let's see who can break this again. :)
786 The upcoming kernel will have a new input driver core integration.
787 Some class devices are now symlinks to the real device. libsysfs
788 needs a fix for this to work correctly. Udevstart of older udev
789 versions will _not_ create these devices!
793 Fix a 'install' target in the Makefile, that prevents EXTRAS from
798 A bunch of mostly trivial bugfixes. From now on no node name or
799 symlink name can contain any character than plain whitelisted ascii
800 characters or validated utf8 byte-streams. This is needed for the
801 /dev/disk/by-label/* links, because we import untrusted data and
802 export it to the filesystem.
806 More bugfixes. If udevd was started from the kernel, we don't
807 have stdin/stdout/stderr, which broke the forked tools in some
812 Bugfix. udevstart event ordering was broken for a long time.
813 The new run_program() uncovered it, because /dev/null was not
814 available while we try to run external programs.
815 Now udevstart should create it before we run anything.
819 Minor bugfixes and some distro rules updates. If you don't have the
820 persistent disk rules in /dev/disk/by-*/* on your distro, just
821 grab it from here. :)
825 We can use socket communication now to pass events from udev to
827 RUN+="socket:/org/freedesktop/hal/udev_event"
828 will pass the whole udev event to the HAL daemon without the need
829 for a forked helper. (See ChangeLog for udevmonitor, as an example)
833 Mostly bugfixes and see ChangeLog.
835 The test for the existence of an environment value should be
837 ENV{KEY}=="*" to ENV{KEY}=="?*"
838 because "*" will not fail anymore, if the key does not exist or
843 Bugfixes and a few tweaks described in the ChangeLog.
847 Mostly a Bugfix release.
849 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
850 timing with custom rules.
854 We changed the internal rule storage format. Our large rule files took
855 2 MB of RAM, with the change we are down to 99kB.
857 If the device-node has been created with default name and no symlink or
858 options are to remenber, it is not longer stored in the udevdb. HAL will
859 need to be updated to work correctly with that change.
861 To overrride optimization flags, OPTFLAGS may be used now.
869 Major changes happened with this release. The goal is to take over the
870 complete kernel-event handling and provide a more efficient way to dispatch
871 kernel events. Replacing most of the current shell script logic and the
872 kernel forked helper with a netlink-daemon and a rule-based event handling.
874 o udevd listens to netlink events now. The first valid netlink event
875 will make udevd ignore any message from udevsend that contains a
876 SEQNUM, to avoid duplicate events. The forked events can be disabled
878 echo "" > /proc/sys/kernel/hotplug
879 For full support, the broken input-subsytem needs to be fixed, not to
880 bypass the driver core.
882 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
883 removed from udev itself and must be emulated by calling small
884 helper binaries provided in the extras folder:
885 make EXTRAS=extras/run_directory/
886 will build udev_run_devd and udev_run_hotplugd, which can be called
887 from a rule if needed:
888 RUN+="/sbin/udev_run_hotplugd"
889 The recommended way to handle this is to convert all the calls from
890 the directories to explicit udev rules and get completely rid of the
891 multiplexing. (To catch a ttyUSB event, you now no longer need to
892 fork and exit 300 tty script instances you are not interested in, it
893 is just one rule that matches exactly the device.)
895 o udev handles now _all_ events not just events for class and block
896 devices, this way it is possible to control the complete event
897 behavior with udev rules. Especially useful for rules like:
898 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
900 o As used in the modalias rule, udev supports now textual
901 substitution placeholder along with the usual format chars. This
902 needs to be documented, for now it's only visible in udev_rules_parse.c.
904 o The rule keys support now more operations. This is documented in the
905 man page. It is possible to add values to list-keys like the SYMLINK
906 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
907 Also "final"-assignments are supported by using KEY:="value", which will
908 prevent changing the key by any later rule.
910 o kernel 2.6.12 has the "detached_state" attribute removed from
911 sysfs, which was used to recognize sysfs population. We switched that
912 to wait for the "bus" link, which is only available in kernels after 2.6.11.
913 Running this udev version on older kernels may cause a short delay for
916 o To provide infrastructure for persistent device naming, the id programs:
917 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
918 to export the probed data in environment key format:
919 pim:~ # /sbin/ata_id --export /dev/hda
920 ID_MODEL=HTS726060M9AT00
921 ID_SERIAL=MRH401M4G6UM9B
925 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
926 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
929 kay@pim:~> tree /dev/disk
932 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
933 | `-- IBM-Memory_Key -> ../../sda
935 | |-- swap -> ../../hda1
936 | |-- date -> ../../sda1
937 | `-- home -> ../../hda3
939 |-- 2E08712B0870F2E7 -> ../../hda3
940 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
941 |-- E845-7A89 -> ../../sda1
942 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
944 The IMPORT= operation will import these keys in the environment and make
945 it available for later PROGRAM= and RUN= executed programs. The keys are
946 also stored in the udevdb and can be queried from there with one of the
949 o A few binaries are silently added to the repository, which can be used
950 to replay kernel events from initramfs instead of using coldplug. udevd
951 can be instructed now to queue-up events while the stored events from
952 initramfs are filled into the udevd-queue. This code is still under
953 development and there is no documentation now besides the code itself.
954 The additional binaries get compiled, but are not installed by default.
956 o There is also a temporary fix for a performance problem where too many
957 events happen in parallel and every event needs to parse the rules.
958 udev can now read precompiled rules stored on disk. This is likely to be
959 replaced by a more elegant solution in a future udev version.
963 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
964 Fix for libsysfs not to expect this file was added.
968 All rules are applied now, but only the first matching rule with a NAME-key
969 will be applied. All later rules with NAME-key are completely ignored. This
970 way system supplied symlinks or permissions gets applied to user-defined
974 Please check your rules setup, if you may need to add OPTIONS="last_rule"
975 to some rules, to keep the old behavior.
977 The rules are read on "remove"-events too. That makes is possible to match
978 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
979 instruct udev to ignore an event (OPTIONS="ignore_device").
980 The new ACTION-key may be used to let a rule act only at a "remove"-event.
982 The new RUN-key supports rule-based execution of programs after device-node
983 handling. This is meant as a general replacement for the dev.d/-directories
984 to give fine grained control over the execution of programs.
986 The %s{}-sysfs format char replacement values are searched at any of the
987 devices in the device chain now, not only at the class-device.
989 We support log priority levels now. The value udev_log in udev.conf is used
990 to determine what is printed to syslog. This makes it possible to
991 run a version with compiled-in debug messages in a production environment
992 which is sometimes needed to find a bug.
993 It is still possible to supress the inclusion of _any_ syslog usage with
994 USE_LOG=false to create the smallest possible binaries if needed.
995 The configured udev_log value can be overridden with the environment variable
1000 Possible use of a system-wide klibc:
1001 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1002 will link against an external klibc and our own version will be ignored.
1006 We support an unlimited count of symlinks now.
1008 If USE_STATIC=true is passed to a glibc build, we link statically and use
1009 a built-in userdb parser to resolve user and group names.
1011 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1012 we walk up the chain of physical devices to find a match.
1014 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1015 easy to skip certain attribute matches without composing rules with weird
1016 character class negations like:
1017 KERNEL="[!s][!c][!d]*"
1018 this can now be replaced with:
1020 The current simple '=' is still supported, and should work as it does today,
1021 but existing rules should be converted if possible, to be better readable.
1023 We have new ENV{}== key now, to match against a maximum of 5 environment
1026 udevstart is its own binary again, because we don't need co carry this araound
1027 with every forked event.