3 Device nodes can be watched for changes with inotify with OPTIONS="watch". If
4 closed after being opened for writing, a "change" uevent will occur.
6 /dev/disk/by-*/* symlinks will be automatically updated.
12 The udevadm test command has no longer a --force option, nodes and symlinks
13 are always updated with a test run now.
15 The udevd daemon can be started with --resolve-names=never to avoid all user
16 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
17 lookup user and groups every time events are handled.
23 We are currently merging the Ubuntu rules in the udev default rules,
24 and get one step closer to provide a common Linux /dev setup, regarding
25 device names, symlinks, and default device permissions. On udev startup,
26 we now expect the following groups to be resolvable to their ids with
28 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
29 LDAP setups need to make sure, that these groups are always resolvable at
30 bootup, with only the rootfs mounted, and without network access available.
32 Some systems may need to add some new, currently not used groups, or need
33 to add some users to new groups, but the cost of this change is minimal,
34 compared to the pain the current, rather random, differences between the
35 various distributions cause for upstream projects and third-party vendors.
37 In general, "normal" users who log into a machine should never be a member
38 of any such group, but the device-access should be managed by dynamic ACLs,
39 which get added and removed for the specific users on login/logout and
40 session activity/inactivity. These groups are only provided for custom setups,
41 and mainly system services, to allow proper privilege separation.
42 A video-streaming daemon uid would be a member of "audio" and "video", to get
43 access to the sound and video devices, but no "normal" user should ever belong
44 to the "audio" group, because he could listen to the built-in microphone with
45 any ssh-session established from the other side of the world.
47 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
48 which do not depend on the kernel device name. As usual, unique
49 devices - only a single one per product connected, or a real
50 USB serial number in the device - are always found with the same
51 name in the by-id/ directory.
52 Completely identical devices may overwrite their names in by-id/
53 and can only be found reliably in the by-path/ directory. Devices
54 specified by by-path/ must not change their connection, like the
55 USB port number they are plugged in, to keep their name.
57 To support some advanced features, Linux 2.6.22 is the oldest supported
58 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
59 supported. Older kernels should still work, and devices nodes should be
60 reliably created, but some rules and libudev will not work correctly because
61 the old kernels do not provide the expected information or interfaces.
67 Fix for a possible segfault while swapping network interface names in udev
74 The group "video" is part of the default rules now.
78 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
79 block devices in some cases. No common distro uses this option anymore,
80 and we do not get enough testing for this and recent udev versions. If
81 this option is not needed to run some old distro with a new kernel,
82 it should be disabled in the kernel config.
84 Bugfix for the $links substitution variable, which may crash if no links
85 are created. This should not happen in usual setups because we always
86 create /dev/{block,char}/ links.
88 The strings of the parsed rules, which are kept in memory, no longer
89 contain duplicate entries, or duplicate tails of strings. This, and the
90 new rules parsing/matching code reduces the total in-memory size of
91 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
94 The export of DEVTYPE=disk/partition got removed from the default
95 rules. This value is available from the kernel. The pnp shell script
96 modprobe hack is removed from the default rules. ACPI devices have _proper_
97 modalias support and take care of the same functionality.
98 Installations which support old kernels, but install current default
99 udev rules may want to add that to the compat rules file.
101 Libvolume_id now always probes for all known filesystems, and does not
102 stop at the first match. Some filesystems are marked as "exclusive probe",
103 and if any other filesytem type matches at the same time, libvolume_id
104 will, by default, not return any probing result. This is intended to prevent
105 mis-detection with conflicting left-over signatures found from earlier
106 file system formats. That way, we no longer depend on the probe-order
107 in case of multiple competing signatures. In some setups the kernel allows
108 to mount a volume with just the old filesystem signature still in place.
109 This may damage the new filesystem and cause data-loss, just by mounting
110 it. Because volume_id can not decide which one the correct signature is,
111 the wrong signatures need to be removed manually from the volume, or the
112 volume needs to be reformatted, to enable filesystem detection and possible
117 Fix segfault if compiled without optimization and dbg() does not get
118 compiled out and uses variables which are not available.
122 Bugfixes. (And maybe new bugs. :))
124 The rule matching engine got converted from a rule list to a token
125 array which reduced the in-memory rules representation of a full
126 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
127 Limits like 5 ENV and ATTR matches, and one single instance for most
128 other keys per rule are gone.
130 The NAME assignment is no longer special cased. If later rules assign
131 a NAME value again, the former value will be overwritten. As usual
132 for most other keys, the NAME value can be protected by doing a final
133 assignment with NAME:="<value>".
135 All udev code now uses libudev, which is also exported. The library
136 is still under development, marked as experimental, and its interface
137 may change as long as the DeviceKit integration is not finished.
139 Many thanks to Alan Jenkins for his continuous help, and finding and
140 optimizing some of the computing expensive parts.
146 Kernel devices and device nodes are connected now by reverse indizes in
147 /sys and /dev. A device number retrieved by a stat() or similar, the
148 kernel device directory can be found by looking up:
149 /sys/dev/{block,char}/<maj>:<min>
150 and the device node of the same device by looking up:
151 /dev/{block,char}/<maj>:<min>
155 Fix recently introduced bug, which caused a compilation without large
156 file support, where vol_id does not recognize raid signatures at the end
159 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
160 Seems some kernel versions prevent the creation of the ieee-* links,
161 so people used the scsi-* link which disappeared now.
163 More libudev work. Almost all udevadm functionality comes from libudev
166 udevadm trigger has a new option --type, which allows to trigger events
167 for "devices", for "subsystems", or "failed" devices. The old option
168 --retry-failed" still works, but is no longer mentioned in the man page.
174 The udevadm info --device-id-of-file= output has changed to use
175 the obvious format. Possible current users should use the --export
176 option which is not affected.
178 The old udev commands symlinks to udevadm are not installed, if
179 these symlinks are used, a warning is printed.
185 Optical drive's media is no longer probed for raid signatures,
186 reading the end of the device causes some devices to malfunction.
187 Also the offset of the last session found is used now to probe
190 The volume_id library got a major version number update to 1,
191 some deprecated functions are removed.
193 A shared library "libudev" gets installed now to provide access
194 to udev device information. DeviceKit, the successor of HAL, will
195 need this library to access the udev database and search sysfs for
197 The library is currently in an experimental state, also the API is
198 expected to change, as long as the DeviceKit integration is not
203 We use ./configure now. See INSTALL for details. Current
206 "/usr" - prefix for man pages, include files
208 "" - the root filesystem, prefix for libs and binaries
212 "lib" - directory name for libraries, not a path name
213 multilib 64bit systems may use "lib64" instead of "lib"
215 compile-in verbose debug messages
217 disable all logging and compile-out all log strings
219 link against SELInux libraries, to set the expected context
222 In the default rules, the group "disk" gets permissions 0660 instead
223 of 0640. One small step closer to unify distro rules. Some day, all
224 distros hopefully end up with the same set of rules.
226 No symlinks to udevadm are installed anymore, if they are still needed,
227 they should be provided by the package.
233 Default udev rules, which are not supposed to be edited by the user, should
234 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
235 the udev package and will be replaced with an update. Udev will pick up rule
237 /lib/udev/rules.d/ - default installed rules
238 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
239 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
240 It does not matter in which directory a rule file lives, all files are sorted
243 To help creating /dev/root, we have now:
244 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
247 In case the current --device-id-of-file is already used, please switch to
248 the --export format version, it saves the output parsing and the old
249 format will be changed to use ':' as a separator, like the format in the
254 Fix cdrom_id to properly recognize blank media.
260 Tape drive id-data is queried from /dev/bsg/* instead of the tape
261 nodes. This avoids rewinding tapes on open().
267 The symlinks udevcontrol and udevtrigger are no longer installed by
270 The scsi_id program does not depend on sysfs anymore. It can speak
271 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
272 data, which should solve some old problems with tape devices, where
273 we better do not open all tape device nodes to identify the device.
279 The cdrom_id program is replaced by an advanced version, which can
280 detect most common device types, and also properties of the inserted
281 media. This is part of moving some basic functionality from HAL into
282 udev (and the kernel).
288 The last WAIT_FOR_SYSFS rule is removed from the default rules.
290 The symlinks to udevadm for the debugging tools: udevmonitor and
291 udevtest are no longer created.
293 The symlinks to the udevadm man page for the old tool names are
296 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
297 should be prefixed with '@' to indicate that the path is not a
308 Udevstart is removed from the tree, it did not get installed for
309 a long time now, and is long replaced by trigger and settle.
315 All udev tools are merged into a single binary called udevadm.
316 The old names of the tools are built-in commands in udevadm now.
317 Symlinks to udevadm, with the names of the old tools, provide
318 the same functionality as the standalone tools. There is also
319 only a single udevadm.8 man page left for all tools.
321 Tools like mkinitramfs should be checked, if they need to include
322 udevadm in the list of files.
332 The etc/udev/rules.d/ directory now contains a default set of basic
333 udev rules. This initial version is the result of a rules file merge
334 of Fedora and openSUSE. For these both distros only a few specific
335 rules are left in their own file, named after the distro. Rules which
336 are optionally installed, because they are only valid for a specific
337 architecture, or rules for subsystems which are not always used are
338 in etc/udev/packages/.
344 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
345 actions by dynamically created rules.
347 SYMLINK=="<value>" matches agains the entries in the list of
348 currently defined symlinks. The links are not created in the
349 filesystem at that point in time, but the values can be matched.
351 RUN{ignore_error}+="<program>" will ignore any exit code from the
352 program and not record as a failed event.
358 Final merge of patches/features from the Ubuntu package.
364 Control characters in filesystem label strings are no longer silenty
365 removed, but hex-encoded, to be able to uniquely identify the device
366 by its symlink in /dev/disk/by-label/.
367 If libvolume_id is used by mount(8), LABEL= will work as expected,
368 if slashes or other characters are used in the label string.
370 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
371 can be specified now. The TEST key accepts an optional mode mask
372 TEST{0100}=="<is executable file>".
374 Scsi_id now supports a mode without expecting scsi-specific sysfs
375 entries to allow the extraction of cciss-device persistent properties.
381 In the future, we may see uuid's which are just simple character
382 strings (see the DDF Raid Specification). For that reason vol_id now
383 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
384 the creation of symlinks, the *_SAFE values ensure, that no control
385 or whitespace characters are used in the filename.
387 Possible users of libvolume_id, please use the volume_id_get_* functions.
388 The public struct will go away in a future release of the library.
394 Removal of useless extras/eventrecorder.sh.
404 The directory multiplexer for dev.d/ and hotplug.d are finally removed
405 from the udev package.
411 Symlinks can have priorities now, the priority is assigned to the device
412 and specified with OPTIONS="link_priority=100". Devices with higher
413 priorities overwrite the symlinks of devices with lower priorities.
414 If the device that currently owns the link, goes away, the symlink
415 will be removed, and recreated, pointing to the next device with the
416 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
417 more reliable, if multiple devices contain the same metadata and overwrite
420 The dasd_id program is removed from the udev tree, and dasdinfo, with the
421 needed rules, are part of the s390-tools now.
423 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
424 we may get the scsi sysfs mess fixed some day, and this will only catch
425 the devices we are looking for.
427 USB serial numbers for storage devices have the target:lun now appended,
428 to make it possibble to distinguish broken multi-lun devices with all
429 the same SCSI identifiers.
431 Note: The extra "run_directory" which searches and executes stuff in
432 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
433 with the next release. Make sure, that you don't use it anymore, or
434 provides your own implementation of that inefficient stuff.
435 We are tired of reports about a "slow udev", because these directories
436 contain stuff, that runs with _every_ event, instead of using rules,
437 that run programs only for the matching events.
447 DRIVER== will match only for devices that actually have a real
448 driver. DRIVERS== must be used, if parent devices should be
449 included in the match.
451 Libvolume_id's "linux_raid" detection needed another fix.
459 Add additional check to volume_id detection of via_raid, cause
460 some company decided to put a matching pattern all over the empty
461 storage area of their music players.
465 Fix path_id for SAS devices.
469 The udev daemon can be started with --debug-trace now, which will
470 execute all events serialized to get a chance to catch a possible
471 action that crashes the box.
473 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
474 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
475 are excluded from the warning. Referencing parent attributes directly
476 may break when something in the kernel driver model changes. Udev will
477 just find the attribute by walking up the parent chain.
479 Udevtrigger now sorts the list of devices depending on the device
480 dependency, so a "usb" device is triggered after the parent "pci"
485 Revert persistent-storage ata-serial '_' '-' replacement.
491 Udevtrigger can now filter the list of devices to be triggered. Matches
492 for subsystems or sysfs attributes can be specified.
494 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
495 zero-sized files to avoid pointing to /sys and confuse broken tools which
496 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
499 The rules and scripts to create udev rules for persistent network
500 devices and optical drives are in the extras/rules_generator directory
501 now. If you use something similar, please consider replacing your own
502 version with this, to share the support effort. The rule_generator
503 installs its own rules into /etc/udev/rules.d.
505 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
506 the rule_generator depends on cdrom_id to be called in an earlier rule.
512 Renaming of some key names (the old names still work):
513 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
514 (The behavior of the key DRIVER will change soon in one of the next
515 releases, to match only the event device, please switch to DRIVERS
516 instead. If DRIVER is used, it will behave like DRIVERS, but an error
518 With the new key names, we have a more consistent and simpler scheme.
519 We can match the properties of the event device only, with: KERNEL,
520 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
521 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
522 longer mentioned in the man page and should be switched in the rule
525 ATTR{file}="value" can be used now, to write to a sysfs file of the
526 event device. Instead of:
527 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
529 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
531 All the PHYSDEV* keys are deprecated and will be removed from a
533 PHYDEVPATH - is the path of a parent device and should not be
535 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
536 matched with SUBSYSTEMS==
537 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
538 Newer kernels will have DRIVER in the environment,
539 for older kernels udev puts in. Class device will
540 no longer carry this property of a parent and
541 DRIVERS== can be used to match such a parent value.
542 Note that ENV{DRIVER} is only available for a few bus devices, where
543 the driver is already bound at device event time. On coldplug, the
544 events for a lot devices are already bound to a driver, and they will have
545 that value set. But on hotplug, at the time the kernel creates the device,
546 it can't know what driver may claim the device after that, therefore
547 in most cases it will be empty.
549 Failed events should now be re-triggered with:
550 udevtrigger --retry-failed.
551 Please switch to this command, so we keep the details of the /dev/.udev/failed/
552 files private to the udev tools. We may need to switch the current symlink
553 target, cause some obviously broken tools try to scan all files in /dev
554 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
555 million times. This takes ages on slow boxes.
557 The udevinfo attribute walk (-a) now works with giving a device node
558 name (-n) instead of a devpath (-p). The query now always works, also when
559 no database file was created by udev.
561 The built-in /etc/passwd /etc/group parser is removed, we always depend on
562 getpwnam() and getgrnam() now. One of the next releases will depend on
563 fnmatch() and may use getopt_long().
567 Bugfixes and small improvements.
571 Fix path_id for recent kernels.
577 Added support for swapping network interface names, by temporarily
578 renaming the device and wait for the target name to become free.
582 The built-in MODALIAS key and substitution is removed.
586 The binary firmware helper is replaced by the usual simple
587 shell script. Udevsend is removed from the tree.
595 Some more keys require the correct use of '==' and '=' depending
596 on the kind of operation beeing an assignment or a match. Rules
597 with invalid operations are skipped and logged to syslog. Please
598 test with udevtest if the parsing of your rules throws errors and
599 fix possibly broken rules.
603 Provide "udevsettle" to wait for all current udev events to finish.
604 It also watches the current kernel netlink queue by comparing the
605 even sequence number to make sure that there are no current pending
606 events that have not already arrived in the daemon.
610 Fix rule to skip persistent rules for removable IDE devices, which
611 also skipped optical IDE drives.
613 All *_id program are installed in /lib/udev/ by default now.
615 No binary is stripped anymore as this should be done in the
616 packaging process and not at build time.
618 libvolume_id is provided as a shared library now and vol_id is
619 linked against it. Also one of the next HAL versions will require
620 this library, and the HAL build process will also require the
621 header file to be installed. The copy of the same code in HAL will
622 be removed to have only a single copy left on the system.
626 Add persistent links for SCSI tapes. The rules file is renamed
627 to 60-persistent-storage.rules.
629 Create persistent path for usb devices. Can be used for all sorts
630 of devices that can't be distinguished by other properties like
631 multiple identical keyboards and mice connected to the same box.
633 Provide "udevtrigger" program to request events on coldplug. The
634 shell script is much too slow with thousends of devices.
638 Fix persistent disk rules to exclude removable IDE drives.
640 Warn if %e, $modalias or MODALIAS is used.
644 Fix queue export, which wasn't correct for subsequent add/remove
645 events for the same device.
649 Fix cramfs detection on big endian.
651 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
656 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
657 attributes were only checked at the parent device that matched the
658 by BUS requested subsystem. Fix it to also look at the device we
659 received the event for.
661 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
666 Fix a bug where NAME="" would prevent RUN from beeing executed.
668 RUN="/bin/program" does not longer automatically add the subsystem
669 as the first parameter. This is from the days of /sbin/hotplug
670 which is dead now and it's just confusing to need to add a space at
671 the end of the program name to prevent this.
672 If you use rules that need the subsystem as the first parameter,
673 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
674 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
678 The udev man page has moved to udev(7) as it does not describe a command
679 anymore. The programs udev, udevstart and udevsend are no longer installed
680 by default and must be copied manually, if they should be installed or
681 included in a package.
683 Fix a bug where "ignore_device" could run earlier collected RUN keys before
684 the ignore rule was applied.
686 More preparation for future sysfs changes. usb_id and scsi_id no longer
687 depend on a magic order of devices in the /devices chain. Specific devices
688 should be requested by their subsytem.
690 This will always find the scsi parent device without depending on a specific
692 dev = sysfs_device_get(devpath);
693 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
695 The "device" link in the current sysfs layout will be automatically
696 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
697 parent in the devpath. If a device is requested by it's symlink, like all
698 class devices in the new sysfs layout will look like, it gets automatically
699 resolved and substituted with the real devpath and not the symlink path.
702 A similar logic must be applied to _all_ sysfs users, including
703 scripts, that search along parent devices in sysfs. The explicit use of
704 the "device" link must be avoided. With the future sysfs layout all
705 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
706 back to the "class" or the "bus". The layout of the parent devices in
707 /devices is not necessarily expected to be stable across kernel releases and
708 searching for parents by their subsystem should make sysfs users tolerant
709 for changed parent chains.
713 Prepare udev to work with the experimental kernel patch, that moves
714 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
716 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
717 moving the class devices to /sys/devices.
719 Thanks again to Marco for help finding a hopefully nice compromise
720 to make %b simpler and working again.
724 Complete removal of libsysfs, replaced by simple helper functions
725 which are much simpler and a bit faster. The udev daemon operatesentirely
726 on event parameters and does not use sysfs for simple rules anymore.
727 Please report any new bugs/problems, that may be caused by this big
728 change. They will be fixed immediately.
730 The enumeration format character '%e' is deprecated and will be
731 removed sometimes from a future udev version. It never worked correctly
732 outside of udevstart, so we can't use it with the new parallel
733 coldplug. A simple enumeration is as useless as the devfs naming
734 scheme, just get rid of both if you still use it.
736 MODALIAS and $modalias is not needed and will be removed from one of
737 the next udev versions, replace it in all rules with ENV{MODALIAS} or
738 the sysfs "modalias" value.
740 Thanks a lot to Marco for all his help on finding and fixing bugs.
744 Let scsi_id request libata drive serial numbers from page 0x80.
746 Renamed etc/udev/persistent.rules to persistent-disk.rules and
747 added /dev/disk/by-name/* for device mapper device names.
749 Removed %e from the man page. It never worked reliably outside
750 of udevstart and udevstart is no longer recommended to use.
754 Symlinks are now exported to the event environment. Hopefully it's no
755 longer needed to run udevinfo from an event process, like it was
756 mentioned on the hotplug list:
757 UDEV [1134776873.702967] add@/block/sdb
760 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
764 Fix a problem if udevsend is used as the hotplug handler and tries to use
765 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
766 and this kind of problems will hopefully go away soon.
770 All built-in logic to work around bad sysfs timing is removed with this
771 version. The need to wait for sysfs files is almost fixed with a kernel
772 version that doesn't work with this udev version anyway. Until we fix
773 the timing of the "bus" link creation, the former integrated logic should
774 be emulated by a rule placed before all other rules:
775 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
777 The option "udev_db" does no longer exist. All udev state will be in
778 /$udev_root/.udev/ now, there is no longer an option to set this
780 If the init script or something else used this value, just depend on
781 this hardcoded path. But remember _all_content_ of this directory is
782 still private to udev and can change at any time.
784 Default location for rule sripts and helper programs is now: /lib/udev/.
785 Everything that is not useful on the commandline should go into this
786 directory. Some of the helpers in the extras folder are installed there
787 now. The rules need to be changed, to find the helpers there.
789 Also /lib/udev/devices is recommended as a directory where packages or
790 the user can place real device nodes, which get copied over to /dev at
791 every boot. This should replace the various solutions with custom config
794 Udevsend does no longer start the udev daemon. This must be done with
795 the init script that prepares /dev on tmpfs and creates the initial nodes,
796 before starting the daemon.
800 Silent a too verbose error logging for the old hotplug.d/ dev.d/
803 The copy of klibc is removed. A systemwide installed version of klibc
804 should be used to build a klibc udev now.
808 NAME="" will not create any nodes, but execute RUN keys. To completely
809 ignore an event the OPTION "ignore_device" should be used.
811 After removal of the reorder queue, events with a TIMEOUT can be executed
812 without any queuing now.
816 Fixed bug in udevd, if inotify is not available. We depend on netlink
817 uevents now, kernels without that event source will not work with that
818 version of udev anymore.
822 The rule parsing happens now in the daemon once at startup, all udev
823 event processes inherit the already parsed rules from the daemon.
824 It is shipped with SUSE10.0 and reduces heavily the system load at
825 startup. The option to save precompiled rules and let the udev process
826 pick the them up is removed, as it's no longer needed.
828 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
829 device. Libsysfs is changed to "translate" the requested link into the
830 real device path, as it would happen with the hotplug event. Otherwise
831 device removal and the udev database will not work.
833 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
836 A few improvements for vol_id, the filesytem probing code.
840 Fix a stupid typo in extras/run_directory for "make install".
842 scsi_id creates the temporary devnode now in /dev for usage with a
843 non-writable /tmp directory.
845 The uevent kernel socket buffer can carry app. 50.000 events now,
846 let's see who can break this again. :)
848 The upcoming kernel will have a new input driver core integration.
849 Some class devices are now symlinks to the real device. libsysfs
850 needs a fix for this to work correctly. Udevstart of older udev
851 versions will _not_ create these devices!
855 Fix a 'install' target in the Makefile, that prevents EXTRAS from
860 A bunch of mostly trivial bugfixes. From now on no node name or
861 symlink name can contain any character than plain whitelisted ascii
862 characters or validated utf8 byte-streams. This is needed for the
863 /dev/disk/by-label/* links, because we import untrusted data and
864 export it to the filesystem.
868 More bugfixes. If udevd was started from the kernel, we don't
869 have stdin/stdout/stderr, which broke the forked tools in some
874 Bugfix. udevstart event ordering was broken for a long time.
875 The new run_program() uncovered it, because /dev/null was not
876 available while we try to run external programs.
877 Now udevstart should create it before we run anything.
881 Minor bugfixes and some distro rules updates. If you don't have the
882 persistent disk rules in /dev/disk/by-*/* on your distro, just
883 grab it from here. :)
887 We can use socket communication now to pass events from udev to
889 RUN+="socket:/org/freedesktop/hal/udev_event"
890 will pass the whole udev event to the HAL daemon without the need
891 for a forked helper. (See ChangeLog for udevmonitor, as an example)
895 Mostly bugfixes and see ChangeLog.
897 The test for the existence of an environment value should be
899 ENV{KEY}=="*" to ENV{KEY}=="?*"
900 because "*" will not fail anymore, if the key does not exist or
905 Bugfixes and a few tweaks described in the ChangeLog.
909 Mostly a Bugfix release.
911 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
912 timing with custom rules.
916 We changed the internal rule storage format. Our large rule files took
917 2 MB of RAM, with the change we are down to 99kB.
919 If the device-node has been created with default name and no symlink or
920 options are to remenber, it is not longer stored in the udevdb. HAL will
921 need to be updated to work correctly with that change.
923 To overrride optimization flags, OPTFLAGS may be used now.
931 Major changes happened with this release. The goal is to take over the
932 complete kernel-event handling and provide a more efficient way to dispatch
933 kernel events. Replacing most of the current shell script logic and the
934 kernel forked helper with a netlink-daemon and a rule-based event handling.
936 o udevd listens to netlink events now. The first valid netlink event
937 will make udevd ignore any message from udevsend that contains a
938 SEQNUM, to avoid duplicate events. The forked events can be disabled
940 echo "" > /proc/sys/kernel/hotplug
941 For full support, the broken input-subsytem needs to be fixed, not to
942 bypass the driver core.
944 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
945 removed from udev itself and must be emulated by calling small
946 helper binaries provided in the extras folder:
947 make EXTRAS=extras/run_directory/
948 will build udev_run_devd and udev_run_hotplugd, which can be called
949 from a rule if needed:
950 RUN+="/sbin/udev_run_hotplugd"
951 The recommended way to handle this is to convert all the calls from
952 the directories to explicit udev rules and get completely rid of the
953 multiplexing. (To catch a ttyUSB event, you now no longer need to
954 fork and exit 300 tty script instances you are not interested in, it
955 is just one rule that matches exactly the device.)
957 o udev handles now _all_ events not just events for class and block
958 devices, this way it is possible to control the complete event
959 behavior with udev rules. Especially useful for rules like:
960 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
962 o As used in the modalias rule, udev supports now textual
963 substitution placeholder along with the usual format chars. This
964 needs to be documented, for now it's only visible in udev_rules_parse.c.
966 o The rule keys support now more operations. This is documented in the
967 man page. It is possible to add values to list-keys like the SYMLINK
968 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
969 Also "final"-assignments are supported by using KEY:="value", which will
970 prevent changing the key by any later rule.
972 o kernel 2.6.12 has the "detached_state" attribute removed from
973 sysfs, which was used to recognize sysfs population. We switched that
974 to wait for the "bus" link, which is only available in kernels after 2.6.11.
975 Running this udev version on older kernels may cause a short delay for
978 o To provide infrastructure for persistent device naming, the id programs:
979 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
980 to export the probed data in environment key format:
981 pim:~ # /sbin/ata_id --export /dev/hda
982 ID_MODEL=HTS726060M9AT00
983 ID_SERIAL=MRH401M4G6UM9B
987 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
988 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
991 kay@pim:~> tree /dev/disk
994 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
995 | `-- IBM-Memory_Key -> ../../sda
997 | |-- swap -> ../../hda1
998 | |-- date -> ../../sda1
999 | `-- home -> ../../hda3
1001 |-- 2E08712B0870F2E7 -> ../../hda3
1002 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1003 |-- E845-7A89 -> ../../sda1
1004 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1006 The IMPORT= operation will import these keys in the environment and make
1007 it available for later PROGRAM= and RUN= executed programs. The keys are
1008 also stored in the udevdb and can be queried from there with one of the
1011 o A few binaries are silently added to the repository, which can be used
1012 to replay kernel events from initramfs instead of using coldplug. udevd
1013 can be instructed now to queue-up events while the stored events from
1014 initramfs are filled into the udevd-queue. This code is still under
1015 development and there is no documentation now besides the code itself.
1016 The additional binaries get compiled, but are not installed by default.
1018 o There is also a temporary fix for a performance problem where too many
1019 events happen in parallel and every event needs to parse the rules.
1020 udev can now read precompiled rules stored on disk. This is likely to be
1021 replaced by a more elegant solution in a future udev version.
1025 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1026 Fix for libsysfs not to expect this file was added.
1030 All rules are applied now, but only the first matching rule with a NAME-key
1031 will be applied. All later rules with NAME-key are completely ignored. This
1032 way system supplied symlinks or permissions gets applied to user-defined
1036 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1037 to some rules, to keep the old behavior.
1039 The rules are read on "remove"-events too. That makes is possible to match
1040 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1041 instruct udev to ignore an event (OPTIONS="ignore_device").
1042 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1044 The new RUN-key supports rule-based execution of programs after device-node
1045 handling. This is meant as a general replacement for the dev.d/-directories
1046 to give fine grained control over the execution of programs.
1048 The %s{}-sysfs format char replacement values are searched at any of the
1049 devices in the device chain now, not only at the class-device.
1051 We support log priority levels now. The value udev_log in udev.conf is used
1052 to determine what is printed to syslog. This makes it possible to
1053 run a version with compiled-in debug messages in a production environment
1054 which is sometimes needed to find a bug.
1055 It is still possible to supress the inclusion of _any_ syslog usage with
1056 USE_LOG=false to create the smallest possible binaries if needed.
1057 The configured udev_log value can be overridden with the environment variable
1062 Possible use of a system-wide klibc:
1063 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1064 will link against an external klibc and our own version will be ignored.
1068 We support an unlimited count of symlinks now.
1070 If USE_STATIC=true is passed to a glibc build, we link statically and use
1071 a built-in userdb parser to resolve user and group names.
1073 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1074 we walk up the chain of physical devices to find a match.
1076 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1077 easy to skip certain attribute matches without composing rules with weird
1078 character class negations like:
1079 KERNEL="[!s][!c][!d]*"
1080 this can now be replaced with:
1082 The current simple '=' is still supported, and should work as it does today,
1083 but existing rules should be converted if possible, to be better readable.
1085 We have new ENV{}== key now, to match against a maximum of 5 environment
1088 udevstart is its own binary again, because we don't need co carry this araound
1089 with every forked event.
~ianmdlvl / elogind.git / blob