5 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
6 is not supported since while and udevd will log an error message at
9 DVB device naming is supplied by the kernel now. In case older kernels
10 need to be supported, the old shell script should be added to a compat
17 The processed udev events get send back to the netlink socket. Libudev
18 provides access to these events. This is work-in-progress, to replace
19 the DeviceKit daemon functionality directly with libudev. There are
20 upcoming kernel changes to allow non-root users to subcribe to these
27 "udevadm settle" now optionally accepts a range of events to wait for,
28 instead of waiting for "all" events.
34 The installed watch for block device metadata changes is now removed
35 during event hadling, because some (broken) tools may be called from udev
36 rules and (wrongly) open the device with write access. After the finished
37 event handling the watch is restored.
43 Device nodes can be watched for changes with inotify with OPTIONS="watch".
44 If closed after being opened for writing, a "change" uevent will occur.
45 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
51 The udevadm test command has no longer a --force option, nodes and symlinks
52 are always updated with a test run now.
54 The udevd daemon can be started with --resolve-names=never to avoid all user
55 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
56 lookup user and groups every time events are handled.
62 We are currently merging the Ubuntu rules in the udev default rules,
63 and get one step closer to provide a common Linux /dev setup, regarding
64 device names, symlinks, and default device permissions. On udev startup,
65 we now expect the following groups to be resolvable to their ids with
67 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
68 LDAP setups need to make sure, that these groups are always resolvable at
69 bootup, with only the rootfs mounted, and without network access available.
71 Some systems may need to add some new, currently not used groups, or need
72 to add some users to new groups, but the cost of this change is minimal,
73 compared to the pain the current, rather random, differences between the
74 various distributions cause for upstream projects and third-party vendors.
76 In general, "normal" users who log into a machine should never be a member
77 of any such group, but the device-access should be managed by dynamic ACLs,
78 which get added and removed for the specific users on login/logout and
79 session activity/inactivity. These groups are only provided for custom setups,
80 and mainly system services, to allow proper privilege separation.
81 A video-streaming daemon uid would be a member of "audio" and "video", to get
82 access to the sound and video devices, but no "normal" user should ever belong
83 to the "audio" group, because he could listen to the built-in microphone with
84 any ssh-session established from the other side of the world.
86 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
87 which do not depend on the kernel device name. As usual, unique
88 devices - only a single one per product connected, or a real
89 USB serial number in the device - are always found with the same
90 name in the by-id/ directory.
91 Completely identical devices may overwrite their names in by-id/
92 and can only be found reliably in the by-path/ directory. Devices
93 specified by by-path/ must not change their connection, like the
94 USB port number they are plugged in, to keep their name.
96 To support some advanced features, Linux 2.6.22 is the oldest supported
97 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
98 supported. Older kernels should still work, and devices nodes should be
99 reliably created, but some rules and libudev will not work correctly because
100 the old kernels do not provide the expected information or interfaces.
106 Fix for a possible segfault while swapping network interface names in udev
113 The group "video" is part of the default rules now.
117 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
118 block devices in some cases. No common distro uses this option anymore,
119 and we do not get enough testing for this and recent udev versions. If
120 this option is not needed to run some old distro with a new kernel,
121 it should be disabled in the kernel config.
123 Bugfix for the $links substitution variable, which may crash if no links
124 are created. This should not happen in usual setups because we always
125 create /dev/{block,char}/ links.
127 The strings of the parsed rules, which are kept in memory, no longer
128 contain duplicate entries, or duplicate tails of strings. This, and the
129 new rules parsing/matching code reduces the total in-memory size of
130 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
133 The export of DEVTYPE=disk/partition got removed from the default
134 rules. This value is available from the kernel. The pnp shell script
135 modprobe hack is removed from the default rules. ACPI devices have _proper_
136 modalias support and take care of the same functionality.
137 Installations which support old kernels, but install current default
138 udev rules may want to add that to the compat rules file.
140 Libvolume_id now always probes for all known filesystems, and does not
141 stop at the first match. Some filesystems are marked as "exclusive probe",
142 and if any other filesytem type matches at the same time, libvolume_id
143 will, by default, not return any probing result. This is intended to prevent
144 mis-detection with conflicting left-over signatures found from earlier
145 file system formats. That way, we no longer depend on the probe-order
146 in case of multiple competing signatures. In some setups the kernel allows
147 to mount a volume with just the old filesystem signature still in place.
148 This may damage the new filesystem and cause data-loss, just by mounting
149 it. Because volume_id can not decide which one the correct signature is,
150 the wrong signatures need to be removed manually from the volume, or the
151 volume needs to be reformatted, to enable filesystem detection and possible
156 Fix segfault if compiled without optimization and dbg() does not get
157 compiled out and uses variables which are not available.
161 Bugfixes. (And maybe new bugs. :))
163 The rule matching engine got converted from a rule list to a token
164 array which reduced the in-memory rules representation of a full
165 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
166 Limits like 5 ENV and ATTR matches, and one single instance for most
167 other keys per rule are gone.
169 The NAME assignment is no longer special cased. If later rules assign
170 a NAME value again, the former value will be overwritten. As usual
171 for most other keys, the NAME value can be protected by doing a final
172 assignment with NAME:="<value>".
174 All udev code now uses libudev, which is also exported. The library
175 is still under development, marked as experimental, and its interface
176 may change as long as the DeviceKit integration is not finished.
178 Many thanks to Alan Jenkins for his continuous help, and finding and
179 optimizing some of the computing expensive parts.
185 Kernel devices and device nodes are connected now by reverse indizes in
186 /sys and /dev. A device number retrieved by a stat() or similar, the
187 kernel device directory can be found by looking up:
188 /sys/dev/{block,char}/<maj>:<min>
189 and the device node of the same device by looking up:
190 /dev/{block,char}/<maj>:<min>
194 Fix recently introduced bug, which caused a compilation without large
195 file support, where vol_id does not recognize raid signatures at the end
198 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
199 Seems some kernel versions prevent the creation of the ieee-* links,
200 so people used the scsi-* link which disappeared now.
202 More libudev work. Almost all udevadm functionality comes from libudev
205 udevadm trigger has a new option --type, which allows to trigger events
206 for "devices", for "subsystems", or "failed" devices. The old option
207 --retry-failed" still works, but is no longer mentioned in the man page.
213 The udevadm info --device-id-of-file= output has changed to use
214 the obvious format. Possible current users should use the --export
215 option which is not affected.
217 The old udev commands symlinks to udevadm are not installed, if
218 these symlinks are used, a warning is printed.
224 Optical drive's media is no longer probed for raid signatures,
225 reading the end of the device causes some devices to malfunction.
226 Also the offset of the last session found is used now to probe
229 The volume_id library got a major version number update to 1,
230 some deprecated functions are removed.
232 A shared library "libudev" gets installed now to provide access
233 to udev device information. DeviceKit, the successor of HAL, will
234 need this library to access the udev database and search sysfs for
236 The library is currently in an experimental state, also the API is
237 expected to change, as long as the DeviceKit integration is not
242 We use ./configure now. See INSTALL for details. Current
245 "/usr" - prefix for man pages, include files
247 "" - the root filesystem, prefix for libs and binaries
251 "lib" - directory name for libraries, not a path name
252 multilib 64bit systems may use "lib64" instead of "lib"
254 compile-in verbose debug messages
256 disable all logging and compile-out all log strings
258 link against SELInux libraries, to set the expected context
261 In the default rules, the group "disk" gets permissions 0660 instead
262 of 0640. One small step closer to unify distro rules. Some day, all
263 distros hopefully end up with the same set of rules.
265 No symlinks to udevadm are installed anymore, if they are still needed,
266 they should be provided by the package.
272 Default udev rules, which are not supposed to be edited by the user, should
273 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
274 the udev package and will be replaced with an update. Udev will pick up rule
276 /lib/udev/rules.d/ - default installed rules
277 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
278 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
279 It does not matter in which directory a rule file lives, all files are sorted
282 To help creating /dev/root, we have now:
283 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
286 In case the current --device-id-of-file is already used, please switch to
287 the --export format version, it saves the output parsing and the old
288 format will be changed to use ':' as a separator, like the format in the
293 Fix cdrom_id to properly recognize blank media.
299 Tape drive id-data is queried from /dev/bsg/* instead of the tape
300 nodes. This avoids rewinding tapes on open().
306 The symlinks udevcontrol and udevtrigger are no longer installed by
309 The scsi_id program does not depend on sysfs anymore. It can speak
310 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
311 data, which should solve some old problems with tape devices, where
312 we better do not open all tape device nodes to identify the device.
318 The cdrom_id program is replaced by an advanced version, which can
319 detect most common device types, and also properties of the inserted
320 media. This is part of moving some basic functionality from HAL into
321 udev (and the kernel).
327 The last WAIT_FOR_SYSFS rule is removed from the default rules.
329 The symlinks to udevadm for the debugging tools: udevmonitor and
330 udevtest are no longer created.
332 The symlinks to the udevadm man page for the old tool names are
335 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
336 should be prefixed with '@' to indicate that the path is not a
347 Udevstart is removed from the tree, it did not get installed for
348 a long time now, and is long replaced by trigger and settle.
354 All udev tools are merged into a single binary called udevadm.
355 The old names of the tools are built-in commands in udevadm now.
356 Symlinks to udevadm, with the names of the old tools, provide
357 the same functionality as the standalone tools. There is also
358 only a single udevadm.8 man page left for all tools.
360 Tools like mkinitramfs should be checked, if they need to include
361 udevadm in the list of files.
371 The etc/udev/rules.d/ directory now contains a default set of basic
372 udev rules. This initial version is the result of a rules file merge
373 of Fedora and openSUSE. For these both distros only a few specific
374 rules are left in their own file, named after the distro. Rules which
375 are optionally installed, because they are only valid for a specific
376 architecture, or rules for subsystems which are not always used are
377 in etc/udev/packages/.
383 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
384 actions by dynamically created rules.
386 SYMLINK=="<value>" matches agains the entries in the list of
387 currently defined symlinks. The links are not created in the
388 filesystem at that point in time, but the values can be matched.
390 RUN{ignore_error}+="<program>" will ignore any exit code from the
391 program and not record as a failed event.
397 Final merge of patches/features from the Ubuntu package.
403 Control characters in filesystem label strings are no longer silenty
404 removed, but hex-encoded, to be able to uniquely identify the device
405 by its symlink in /dev/disk/by-label/.
406 If libvolume_id is used by mount(8), LABEL= will work as expected,
407 if slashes or other characters are used in the label string.
409 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
410 can be specified now. The TEST key accepts an optional mode mask
411 TEST{0100}=="<is executable file>".
413 Scsi_id now supports a mode without expecting scsi-specific sysfs
414 entries to allow the extraction of cciss-device persistent properties.
420 In the future, we may see uuid's which are just simple character
421 strings (see the DDF Raid Specification). For that reason vol_id now
422 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
423 the creation of symlinks, the *_SAFE values ensure, that no control
424 or whitespace characters are used in the filename.
426 Possible users of libvolume_id, please use the volume_id_get_* functions.
427 The public struct will go away in a future release of the library.
433 Removal of useless extras/eventrecorder.sh.
443 The directory multiplexer for dev.d/ and hotplug.d are finally removed
444 from the udev package.
450 Symlinks can have priorities now, the priority is assigned to the device
451 and specified with OPTIONS="link_priority=100". Devices with higher
452 priorities overwrite the symlinks of devices with lower priorities.
453 If the device that currently owns the link, goes away, the symlink
454 will be removed, and recreated, pointing to the next device with the
455 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
456 more reliable, if multiple devices contain the same metadata and overwrite
459 The dasd_id program is removed from the udev tree, and dasdinfo, with the
460 needed rules, are part of the s390-tools now.
462 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
463 we may get the scsi sysfs mess fixed some day, and this will only catch
464 the devices we are looking for.
466 USB serial numbers for storage devices have the target:lun now appended,
467 to make it possibble to distinguish broken multi-lun devices with all
468 the same SCSI identifiers.
470 Note: The extra "run_directory" which searches and executes stuff in
471 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
472 with the next release. Make sure, that you don't use it anymore, or
473 provides your own implementation of that inefficient stuff.
474 We are tired of reports about a "slow udev", because these directories
475 contain stuff, that runs with _every_ event, instead of using rules,
476 that run programs only for the matching events.
486 DRIVER== will match only for devices that actually have a real
487 driver. DRIVERS== must be used, if parent devices should be
488 included in the match.
490 Libvolume_id's "linux_raid" detection needed another fix.
498 Add additional check to volume_id detection of via_raid, cause
499 some company decided to put a matching pattern all over the empty
500 storage area of their music players.
504 Fix path_id for SAS devices.
508 The udev daemon can be started with --debug-trace now, which will
509 execute all events serialized to get a chance to catch a possible
510 action that crashes the box.
512 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
513 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
514 are excluded from the warning. Referencing parent attributes directly
515 may break when something in the kernel driver model changes. Udev will
516 just find the attribute by walking up the parent chain.
518 Udevtrigger now sorts the list of devices depending on the device
519 dependency, so a "usb" device is triggered after the parent "pci"
524 Revert persistent-storage ata-serial '_' '-' replacement.
530 Udevtrigger can now filter the list of devices to be triggered. Matches
531 for subsystems or sysfs attributes can be specified.
533 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
534 zero-sized files to avoid pointing to /sys and confuse broken tools which
535 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
538 The rules and scripts to create udev rules for persistent network
539 devices and optical drives are in the extras/rules_generator directory
540 now. If you use something similar, please consider replacing your own
541 version with this, to share the support effort. The rule_generator
542 installs its own rules into /etc/udev/rules.d.
544 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
545 the rule_generator depends on cdrom_id to be called in an earlier rule.
551 Renaming of some key names (the old names still work):
552 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
553 (The behavior of the key DRIVER will change soon in one of the next
554 releases, to match only the event device, please switch to DRIVERS
555 instead. If DRIVER is used, it will behave like DRIVERS, but an error
557 With the new key names, we have a more consistent and simpler scheme.
558 We can match the properties of the event device only, with: KERNEL,
559 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
560 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
561 longer mentioned in the man page and should be switched in the rule
564 ATTR{file}="value" can be used now, to write to a sysfs file of the
565 event device. Instead of:
566 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
568 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
570 All the PHYSDEV* keys are deprecated and will be removed from a
572 PHYDEVPATH - is the path of a parent device and should not be
574 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
575 matched with SUBSYSTEMS==
576 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
577 Newer kernels will have DRIVER in the environment,
578 for older kernels udev puts in. Class device will
579 no longer carry this property of a parent and
580 DRIVERS== can be used to match such a parent value.
581 Note that ENV{DRIVER} is only available for a few bus devices, where
582 the driver is already bound at device event time. On coldplug, the
583 events for a lot devices are already bound to a driver, and they will have
584 that value set. But on hotplug, at the time the kernel creates the device,
585 it can't know what driver may claim the device after that, therefore
586 in most cases it will be empty.
588 Failed events should now be re-triggered with:
589 udevtrigger --retry-failed.
590 Please switch to this command, so we keep the details of the /dev/.udev/failed/
591 files private to the udev tools. We may need to switch the current symlink
592 target, cause some obviously broken tools try to scan all files in /dev
593 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
594 million times. This takes ages on slow boxes.
596 The udevinfo attribute walk (-a) now works with giving a device node
597 name (-n) instead of a devpath (-p). The query now always works, also when
598 no database file was created by udev.
600 The built-in /etc/passwd /etc/group parser is removed, we always depend on
601 getpwnam() and getgrnam() now. One of the next releases will depend on
602 fnmatch() and may use getopt_long().
606 Bugfixes and small improvements.
610 Fix path_id for recent kernels.
616 Added support for swapping network interface names, by temporarily
617 renaming the device and wait for the target name to become free.
621 The built-in MODALIAS key and substitution is removed.
625 The binary firmware helper is replaced by the usual simple
626 shell script. Udevsend is removed from the tree.
634 Some more keys require the correct use of '==' and '=' depending
635 on the kind of operation beeing an assignment or a match. Rules
636 with invalid operations are skipped and logged to syslog. Please
637 test with udevtest if the parsing of your rules throws errors and
638 fix possibly broken rules.
642 Provide "udevsettle" to wait for all current udev events to finish.
643 It also watches the current kernel netlink queue by comparing the
644 even sequence number to make sure that there are no current pending
645 events that have not already arrived in the daemon.
649 Fix rule to skip persistent rules for removable IDE devices, which
650 also skipped optical IDE drives.
652 All *_id program are installed in /lib/udev/ by default now.
654 No binary is stripped anymore as this should be done in the
655 packaging process and not at build time.
657 libvolume_id is provided as a shared library now and vol_id is
658 linked against it. Also one of the next HAL versions will require
659 this library, and the HAL build process will also require the
660 header file to be installed. The copy of the same code in HAL will
661 be removed to have only a single copy left on the system.
665 Add persistent links for SCSI tapes. The rules file is renamed
666 to 60-persistent-storage.rules.
668 Create persistent path for usb devices. Can be used for all sorts
669 of devices that can't be distinguished by other properties like
670 multiple identical keyboards and mice connected to the same box.
672 Provide "udevtrigger" program to request events on coldplug. The
673 shell script is much too slow with thousends of devices.
677 Fix persistent disk rules to exclude removable IDE drives.
679 Warn if %e, $modalias or MODALIAS is used.
683 Fix queue export, which wasn't correct for subsequent add/remove
684 events for the same device.
688 Fix cramfs detection on big endian.
690 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
695 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
696 attributes were only checked at the parent device that matched the
697 by BUS requested subsystem. Fix it to also look at the device we
698 received the event for.
700 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
705 Fix a bug where NAME="" would prevent RUN from beeing executed.
707 RUN="/bin/program" does not longer automatically add the subsystem
708 as the first parameter. This is from the days of /sbin/hotplug
709 which is dead now and it's just confusing to need to add a space at
710 the end of the program name to prevent this.
711 If you use rules that need the subsystem as the first parameter,
712 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
713 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
717 The udev man page has moved to udev(7) as it does not describe a command
718 anymore. The programs udev, udevstart and udevsend are no longer installed
719 by default and must be copied manually, if they should be installed or
720 included in a package.
722 Fix a bug where "ignore_device" could run earlier collected RUN keys before
723 the ignore rule was applied.
725 More preparation for future sysfs changes. usb_id and scsi_id no longer
726 depend on a magic order of devices in the /devices chain. Specific devices
727 should be requested by their subsytem.
729 This will always find the scsi parent device without depending on a specific
731 dev = sysfs_device_get(devpath);
732 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
734 The "device" link in the current sysfs layout will be automatically
735 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
736 parent in the devpath. If a device is requested by it's symlink, like all
737 class devices in the new sysfs layout will look like, it gets automatically
738 resolved and substituted with the real devpath and not the symlink path.
741 A similar logic must be applied to _all_ sysfs users, including
742 scripts, that search along parent devices in sysfs. The explicit use of
743 the "device" link must be avoided. With the future sysfs layout all
744 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
745 back to the "class" or the "bus". The layout of the parent devices in
746 /devices is not necessarily expected to be stable across kernel releases and
747 searching for parents by their subsystem should make sysfs users tolerant
748 for changed parent chains.
752 Prepare udev to work with the experimental kernel patch, that moves
753 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
755 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
756 moving the class devices to /sys/devices.
758 Thanks again to Marco for help finding a hopefully nice compromise
759 to make %b simpler and working again.
763 Complete removal of libsysfs, replaced by simple helper functions
764 which are much simpler and a bit faster. The udev daemon operatesentirely
765 on event parameters and does not use sysfs for simple rules anymore.
766 Please report any new bugs/problems, that may be caused by this big
767 change. They will be fixed immediately.
769 The enumeration format character '%e' is deprecated and will be
770 removed sometimes from a future udev version. It never worked correctly
771 outside of udevstart, so we can't use it with the new parallel
772 coldplug. A simple enumeration is as useless as the devfs naming
773 scheme, just get rid of both if you still use it.
775 MODALIAS and $modalias is not needed and will be removed from one of
776 the next udev versions, replace it in all rules with ENV{MODALIAS} or
777 the sysfs "modalias" value.
779 Thanks a lot to Marco for all his help on finding and fixing bugs.
783 Let scsi_id request libata drive serial numbers from page 0x80.
785 Renamed etc/udev/persistent.rules to persistent-disk.rules and
786 added /dev/disk/by-name/* for device mapper device names.
788 Removed %e from the man page. It never worked reliably outside
789 of udevstart and udevstart is no longer recommended to use.
793 Symlinks are now exported to the event environment. Hopefully it's no
794 longer needed to run udevinfo from an event process, like it was
795 mentioned on the hotplug list:
796 UDEV [1134776873.702967] add@/block/sdb
799 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
803 Fix a problem if udevsend is used as the hotplug handler and tries to use
804 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
805 and this kind of problems will hopefully go away soon.
809 All built-in logic to work around bad sysfs timing is removed with this
810 version. The need to wait for sysfs files is almost fixed with a kernel
811 version that doesn't work with this udev version anyway. Until we fix
812 the timing of the "bus" link creation, the former integrated logic should
813 be emulated by a rule placed before all other rules:
814 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
816 The option "udev_db" does no longer exist. All udev state will be in
817 /$udev_root/.udev/ now, there is no longer an option to set this
819 If the init script or something else used this value, just depend on
820 this hardcoded path. But remember _all_content_ of this directory is
821 still private to udev and can change at any time.
823 Default location for rule sripts and helper programs is now: /lib/udev/.
824 Everything that is not useful on the commandline should go into this
825 directory. Some of the helpers in the extras folder are installed there
826 now. The rules need to be changed, to find the helpers there.
828 Also /lib/udev/devices is recommended as a directory where packages or
829 the user can place real device nodes, which get copied over to /dev at
830 every boot. This should replace the various solutions with custom config
833 Udevsend does no longer start the udev daemon. This must be done with
834 the init script that prepares /dev on tmpfs and creates the initial nodes,
835 before starting the daemon.
839 Silent a too verbose error logging for the old hotplug.d/ dev.d/
842 The copy of klibc is removed. A systemwide installed version of klibc
843 should be used to build a klibc udev now.
847 NAME="" will not create any nodes, but execute RUN keys. To completely
848 ignore an event the OPTION "ignore_device" should be used.
850 After removal of the reorder queue, events with a TIMEOUT can be executed
851 without any queuing now.
855 Fixed bug in udevd, if inotify is not available. We depend on netlink
856 uevents now, kernels without that event source will not work with that
857 version of udev anymore.
861 The rule parsing happens now in the daemon once at startup, all udev
862 event processes inherit the already parsed rules from the daemon.
863 It is shipped with SUSE10.0 and reduces heavily the system load at
864 startup. The option to save precompiled rules and let the udev process
865 pick the them up is removed, as it's no longer needed.
867 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
868 device. Libsysfs is changed to "translate" the requested link into the
869 real device path, as it would happen with the hotplug event. Otherwise
870 device removal and the udev database will not work.
872 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
875 A few improvements for vol_id, the filesytem probing code.
879 Fix a stupid typo in extras/run_directory for "make install".
881 scsi_id creates the temporary devnode now in /dev for usage with a
882 non-writable /tmp directory.
884 The uevent kernel socket buffer can carry app. 50.000 events now,
885 let's see who can break this again. :)
887 The upcoming kernel will have a new input driver core integration.
888 Some class devices are now symlinks to the real device. libsysfs
889 needs a fix for this to work correctly. Udevstart of older udev
890 versions will _not_ create these devices!
894 Fix a 'install' target in the Makefile, that prevents EXTRAS from
899 A bunch of mostly trivial bugfixes. From now on no node name or
900 symlink name can contain any character than plain whitelisted ascii
901 characters or validated utf8 byte-streams. This is needed for the
902 /dev/disk/by-label/* links, because we import untrusted data and
903 export it to the filesystem.
907 More bugfixes. If udevd was started from the kernel, we don't
908 have stdin/stdout/stderr, which broke the forked tools in some
913 Bugfix. udevstart event ordering was broken for a long time.
914 The new run_program() uncovered it, because /dev/null was not
915 available while we try to run external programs.
916 Now udevstart should create it before we run anything.
920 Minor bugfixes and some distro rules updates. If you don't have the
921 persistent disk rules in /dev/disk/by-*/* on your distro, just
922 grab it from here. :)
926 We can use socket communication now to pass events from udev to
928 RUN+="socket:/org/freedesktop/hal/udev_event"
929 will pass the whole udev event to the HAL daemon without the need
930 for a forked helper. (See ChangeLog for udevmonitor, as an example)
934 Mostly bugfixes and see ChangeLog.
936 The test for the existence of an environment value should be
938 ENV{KEY}=="*" to ENV{KEY}=="?*"
939 because "*" will not fail anymore, if the key does not exist or
944 Bugfixes and a few tweaks described in the ChangeLog.
948 Mostly a Bugfix release.
950 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
951 timing with custom rules.
955 We changed the internal rule storage format. Our large rule files took
956 2 MB of RAM, with the change we are down to 99kB.
958 If the device-node has been created with default name and no symlink or
959 options are to remenber, it is not longer stored in the udevdb. HAL will
960 need to be updated to work correctly with that change.
962 To overrride optimization flags, OPTFLAGS may be used now.
970 Major changes happened with this release. The goal is to take over the
971 complete kernel-event handling and provide a more efficient way to dispatch
972 kernel events. Replacing most of the current shell script logic and the
973 kernel forked helper with a netlink-daemon and a rule-based event handling.
975 o udevd listens to netlink events now. The first valid netlink event
976 will make udevd ignore any message from udevsend that contains a
977 SEQNUM, to avoid duplicate events. The forked events can be disabled
979 echo "" > /proc/sys/kernel/hotplug
980 For full support, the broken input-subsytem needs to be fixed, not to
981 bypass the driver core.
983 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
984 removed from udev itself and must be emulated by calling small
985 helper binaries provided in the extras folder:
986 make EXTRAS=extras/run_directory/
987 will build udev_run_devd and udev_run_hotplugd, which can be called
988 from a rule if needed:
989 RUN+="/sbin/udev_run_hotplugd"
990 The recommended way to handle this is to convert all the calls from
991 the directories to explicit udev rules and get completely rid of the
992 multiplexing. (To catch a ttyUSB event, you now no longer need to
993 fork and exit 300 tty script instances you are not interested in, it
994 is just one rule that matches exactly the device.)
996 o udev handles now _all_ events not just events for class and block
997 devices, this way it is possible to control the complete event
998 behavior with udev rules. Especially useful for rules like:
999 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1001 o As used in the modalias rule, udev supports now textual
1002 substitution placeholder along with the usual format chars. This
1003 needs to be documented, for now it's only visible in udev_rules_parse.c.
1005 o The rule keys support now more operations. This is documented in the
1006 man page. It is possible to add values to list-keys like the SYMLINK
1007 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1008 Also "final"-assignments are supported by using KEY:="value", which will
1009 prevent changing the key by any later rule.
1011 o kernel 2.6.12 has the "detached_state" attribute removed from
1012 sysfs, which was used to recognize sysfs population. We switched that
1013 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1014 Running this udev version on older kernels may cause a short delay for
1017 o To provide infrastructure for persistent device naming, the id programs:
1018 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1019 to export the probed data in environment key format:
1020 pim:~ # /sbin/ata_id --export /dev/hda
1021 ID_MODEL=HTS726060M9AT00
1022 ID_SERIAL=MRH401M4G6UM9B
1023 ID_REVISION=MH4OA6BA
1025 The following rules:
1026 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1027 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1030 kay@pim:~> tree /dev/disk
1033 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1034 | `-- IBM-Memory_Key -> ../../sda
1036 | |-- swap -> ../../hda1
1037 | |-- date -> ../../sda1
1038 | `-- home -> ../../hda3
1040 |-- 2E08712B0870F2E7 -> ../../hda3
1041 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1042 |-- E845-7A89 -> ../../sda1
1043 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1045 The IMPORT= operation will import these keys in the environment and make
1046 it available for later PROGRAM= and RUN= executed programs. The keys are
1047 also stored in the udevdb and can be queried from there with one of the
1050 o A few binaries are silently added to the repository, which can be used
1051 to replay kernel events from initramfs instead of using coldplug. udevd
1052 can be instructed now to queue-up events while the stored events from
1053 initramfs are filled into the udevd-queue. This code is still under
1054 development and there is no documentation now besides the code itself.
1055 The additional binaries get compiled, but are not installed by default.
1057 o There is also a temporary fix for a performance problem where too many
1058 events happen in parallel and every event needs to parse the rules.
1059 udev can now read precompiled rules stored on disk. This is likely to be
1060 replaced by a more elegant solution in a future udev version.
1064 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1065 Fix for libsysfs not to expect this file was added.
1069 All rules are applied now, but only the first matching rule with a NAME-key
1070 will be applied. All later rules with NAME-key are completely ignored. This
1071 way system supplied symlinks or permissions gets applied to user-defined
1075 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1076 to some rules, to keep the old behavior.
1078 The rules are read on "remove"-events too. That makes is possible to match
1079 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1080 instruct udev to ignore an event (OPTIONS="ignore_device").
1081 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1083 The new RUN-key supports rule-based execution of programs after device-node
1084 handling. This is meant as a general replacement for the dev.d/-directories
1085 to give fine grained control over the execution of programs.
1087 The %s{}-sysfs format char replacement values are searched at any of the
1088 devices in the device chain now, not only at the class-device.
1090 We support log priority levels now. The value udev_log in udev.conf is used
1091 to determine what is printed to syslog. This makes it possible to
1092 run a version with compiled-in debug messages in a production environment
1093 which is sometimes needed to find a bug.
1094 It is still possible to supress the inclusion of _any_ syslog usage with
1095 USE_LOG=false to create the smallest possible binaries if needed.
1096 The configured udev_log value can be overridden with the environment variable
1101 Possible use of a system-wide klibc:
1102 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1103 will link against an external klibc and our own version will be ignored.
1107 We support an unlimited count of symlinks now.
1109 If USE_STATIC=true is passed to a glibc build, we link statically and use
1110 a built-in userdb parser to resolve user and group names.
1112 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1113 we walk up the chain of physical devices to find a match.
1115 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1116 easy to skip certain attribute matches without composing rules with weird
1117 character class negations like:
1118 KERNEL="[!s][!c][!d]*"
1119 this can now be replaced with:
1121 The current simple '=' is still supported, and should work as it does today,
1122 but existing rules should be converted if possible, to be better readable.
1124 We have new ENV{}== key now, to match against a maximum of 5 environment
1127 udevstart is its own binary again, because we don't need co carry this araound
1128 with every forked event.
~ianmdlvl / elogind.git / blob