5 The format of the queue exported by the udev damon has changed. There is
6 no longer a /dev/.udev/queue/ directory. The queue can be accessed with
7 udevadm settle and libudedv.
13 The program vol_id and the library libvolume_id are removed from the
14 repository. Libvolume_id is merged with libblkid from the util-linux-ng
15 package. Persistent disk links for label and uuid depend on the
16 util-linux-ng version (2.15) of blkid now. Older versions of blkid
17 can not be used with udev.
19 Libudev allows to subscribe to udev events. To prevent unwanted messages
20 to be delivered, and waking up the subscribing process, a filter can be
21 installed, to drop messages inside a kernel socket filter. The filters
22 match on the <subsytem>:<devtype> properties of the device.
23 This is part of the ongoing effort to replace HAL, and switch current
24 users over to directly use libudev.
25 Libudev is still marked as experimental, and its interface might
26 eventually change if needed, but no major changes of the currently exported
27 interface are expected anymore, and a first stable release should happen
30 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
31 is not supported since while and udevd will log an error message at
32 startup. It should still be able to boot-up, but advanced rules and system
33 services which depend on the information not available in the old sysfs
34 format will fail to work correctly.
36 DVB device naming is supplied by the kernel now. In case older kernels
37 need to be supported, the old shell script should be added to a compat
44 The processed udev events get send back to the netlink socket. Libudev
45 provides access to these events. This is work-in-progress, to replace
46 the DeviceKit daemon functionality directly with libudev. There are
47 upcoming kernel changes to allow non-root users to subcribe to these
54 "udevadm settle" now optionally accepts a range of events to wait for,
55 instead of waiting for "all" events.
61 The installed watch for block device metadata changes is now removed
62 during event hadling, because some (broken) tools may be called from udev
63 rules and (wrongly) open the device with write access. After the finished
64 event handling the watch is restored.
70 Device nodes can be watched for changes with inotify with OPTIONS="watch".
71 If closed after being opened for writing, a "change" uevent will occur.
72 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
78 The udevadm test command has no longer a --force option, nodes and symlinks
79 are always updated with a test run now.
81 The udevd daemon can be started with --resolve-names=never to avoid all user
82 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
83 lookup user and groups every time events are handled.
89 We are currently merging the Ubuntu rules in the udev default rules,
90 and get one step closer to provide a common Linux /dev setup, regarding
91 device names, symlinks, and default device permissions. On udev startup,
92 we now expect the following groups to be resolvable to their ids with
94 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
95 LDAP setups need to make sure, that these groups are always resolvable at
96 bootup, with only the rootfs mounted, and without network access available.
98 Some systems may need to add some new, currently not used groups, or need
99 to add some users to new groups, but the cost of this change is minimal,
100 compared to the pain the current, rather random, differences between the
101 various distributions cause for upstream projects and third-party vendors.
103 In general, "normal" users who log into a machine should never be a member
104 of any such group, but the device-access should be managed by dynamic ACLs,
105 which get added and removed for the specific users on login/logout and
106 session activity/inactivity. These groups are only provided for custom setups,
107 and mainly system services, to allow proper privilege separation.
108 A video-streaming daemon uid would be a member of "audio" and "video", to get
109 access to the sound and video devices, but no "normal" user should ever belong
110 to the "audio" group, because he could listen to the built-in microphone with
111 any ssh-session established from the other side of the world.
113 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
114 which do not depend on the kernel device name. As usual, unique
115 devices - only a single one per product connected, or a real
116 USB serial number in the device - are always found with the same
117 name in the by-id/ directory.
118 Completely identical devices may overwrite their names in by-id/
119 and can only be found reliably in the by-path/ directory. Devices
120 specified by by-path/ must not change their connection, like the
121 USB port number they are plugged in, to keep their name.
123 To support some advanced features, Linux 2.6.22 is the oldest supported
124 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
125 supported. Older kernels should still work, and devices nodes should be
126 reliably created, but some rules and libudev will not work correctly because
127 the old kernels do not provide the expected information or interfaces.
133 Fix for a possible segfault while swapping network interface names in udev
140 The group "video" is part of the default rules now.
144 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
145 block devices in some cases. No common distro uses this option anymore,
146 and we do not get enough testing for this and recent udev versions. If
147 this option is not needed to run some old distro with a new kernel,
148 it should be disabled in the kernel config.
150 Bugfix for the $links substitution variable, which may crash if no links
151 are created. This should not happen in usual setups because we always
152 create /dev/{block,char}/ links.
154 The strings of the parsed rules, which are kept in memory, no longer
155 contain duplicate entries, or duplicate tails of strings. This, and the
156 new rules parsing/matching code reduces the total in-memory size of
157 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
160 The export of DEVTYPE=disk/partition got removed from the default
161 rules. This value is available from the kernel. The pnp shell script
162 modprobe hack is removed from the default rules. ACPI devices have _proper_
163 modalias support and take care of the same functionality.
164 Installations which support old kernels, but install current default
165 udev rules may want to add that to the compat rules file.
167 Libvolume_id now always probes for all known filesystems, and does not
168 stop at the first match. Some filesystems are marked as "exclusive probe",
169 and if any other filesytem type matches at the same time, libvolume_id
170 will, by default, not return any probing result. This is intended to prevent
171 mis-detection with conflicting left-over signatures found from earlier
172 file system formats. That way, we no longer depend on the probe-order
173 in case of multiple competing signatures. In some setups the kernel allows
174 to mount a volume with just the old filesystem signature still in place.
175 This may damage the new filesystem and cause data-loss, just by mounting
176 it. Because volume_id can not decide which one the correct signature is,
177 the wrong signatures need to be removed manually from the volume, or the
178 volume needs to be reformatted, to enable filesystem detection and possible
183 Fix segfault if compiled without optimization and dbg() does not get
184 compiled out and uses variables which are not available.
188 Bugfixes. (And maybe new bugs. :))
190 The rule matching engine got converted from a rule list to a token
191 array which reduced the in-memory rules representation of a full
192 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
193 Limits like 5 ENV and ATTR matches, and one single instance for most
194 other keys per rule are gone.
196 The NAME assignment is no longer special cased. If later rules assign
197 a NAME value again, the former value will be overwritten. As usual
198 for most other keys, the NAME value can be protected by doing a final
199 assignment with NAME:="<value>".
201 All udev code now uses libudev, which is also exported. The library
202 is still under development, marked as experimental, and its interface
203 may change as long as the DeviceKit integration is not finished.
205 Many thanks to Alan Jenkins for his continuous help, and finding and
206 optimizing some of the computing expensive parts.
212 Kernel devices and device nodes are connected now by reverse indizes in
213 /sys and /dev. A device number retrieved by a stat() or similar, the
214 kernel device directory can be found by looking up:
215 /sys/dev/{block,char}/<maj>:<min>
216 and the device node of the same device by looking up:
217 /dev/{block,char}/<maj>:<min>
221 Fix recently introduced bug, which caused a compilation without large
222 file support, where vol_id does not recognize raid signatures at the end
225 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
226 Seems some kernel versions prevent the creation of the ieee-* links,
227 so people used the scsi-* link which disappeared now.
229 More libudev work. Almost all udevadm functionality comes from libudev
232 udevadm trigger has a new option --type, which allows to trigger events
233 for "devices", for "subsystems", or "failed" devices. The old option
234 --retry-failed" still works, but is no longer mentioned in the man page.
240 The udevadm info --device-id-of-file= output has changed to use
241 the obvious format. Possible current users should use the --export
242 option which is not affected.
244 The old udev commands symlinks to udevadm are not installed, if
245 these symlinks are used, a warning is printed.
251 Optical drive's media is no longer probed for raid signatures,
252 reading the end of the device causes some devices to malfunction.
253 Also the offset of the last session found is used now to probe
256 The volume_id library got a major version number update to 1,
257 some deprecated functions are removed.
259 A shared library "libudev" gets installed now to provide access
260 to udev device information. DeviceKit, the successor of HAL, will
261 need this library to access the udev database and search sysfs for
263 The library is currently in an experimental state, also the API is
264 expected to change, as long as the DeviceKit integration is not
269 We use ./configure now. See INSTALL for details. Current
272 "/usr" - prefix for man pages, include files
274 "" - the root filesystem, prefix for libs and binaries
278 "lib" - directory name for libraries, not a path name
279 multilib 64bit systems may use "lib64" instead of "lib"
281 compile-in verbose debug messages
283 disable all logging and compile-out all log strings
285 link against SELInux libraries, to set the expected context
288 In the default rules, the group "disk" gets permissions 0660 instead
289 of 0640. One small step closer to unify distro rules. Some day, all
290 distros hopefully end up with the same set of rules.
292 No symlinks to udevadm are installed anymore, if they are still needed,
293 they should be provided by the package.
299 Default udev rules, which are not supposed to be edited by the user, should
300 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
301 the udev package and will be replaced with an update. Udev will pick up rule
303 /lib/udev/rules.d/ - default installed rules
304 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
305 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
306 It does not matter in which directory a rule file lives, all files are sorted
309 To help creating /dev/root, we have now:
310 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
313 In case the current --device-id-of-file is already used, please switch to
314 the --export format version, it saves the output parsing and the old
315 format will be changed to use ':' as a separator, like the format in the
320 Fix cdrom_id to properly recognize blank media.
326 Tape drive id-data is queried from /dev/bsg/* instead of the tape
327 nodes. This avoids rewinding tapes on open().
333 The symlinks udevcontrol and udevtrigger are no longer installed by
336 The scsi_id program does not depend on sysfs anymore. It can speak
337 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
338 data, which should solve some old problems with tape devices, where
339 we better do not open all tape device nodes to identify the device.
345 The cdrom_id program is replaced by an advanced version, which can
346 detect most common device types, and also properties of the inserted
347 media. This is part of moving some basic functionality from HAL into
348 udev (and the kernel).
354 The last WAIT_FOR_SYSFS rule is removed from the default rules.
356 The symlinks to udevadm for the debugging tools: udevmonitor and
357 udevtest are no longer created.
359 The symlinks to the udevadm man page for the old tool names are
362 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
363 should be prefixed with '@' to indicate that the path is not a
374 Udevstart is removed from the tree, it did not get installed for
375 a long time now, and is long replaced by trigger and settle.
381 All udev tools are merged into a single binary called udevadm.
382 The old names of the tools are built-in commands in udevadm now.
383 Symlinks to udevadm, with the names of the old tools, provide
384 the same functionality as the standalone tools. There is also
385 only a single udevadm.8 man page left for all tools.
387 Tools like mkinitramfs should be checked, if they need to include
388 udevadm in the list of files.
398 The etc/udev/rules.d/ directory now contains a default set of basic
399 udev rules. This initial version is the result of a rules file merge
400 of Fedora and openSUSE. For these both distros only a few specific
401 rules are left in their own file, named after the distro. Rules which
402 are optionally installed, because they are only valid for a specific
403 architecture, or rules for subsystems which are not always used are
404 in etc/udev/packages/.
410 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
411 actions by dynamically created rules.
413 SYMLINK=="<value>" matches agains the entries in the list of
414 currently defined symlinks. The links are not created in the
415 filesystem at that point in time, but the values can be matched.
417 RUN{ignore_error}+="<program>" will ignore any exit code from the
418 program and not record as a failed event.
424 Final merge of patches/features from the Ubuntu package.
430 Control characters in filesystem label strings are no longer silenty
431 removed, but hex-encoded, to be able to uniquely identify the device
432 by its symlink in /dev/disk/by-label/.
433 If libvolume_id is used by mount(8), LABEL= will work as expected,
434 if slashes or other characters are used in the label string.
436 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
437 can be specified now. The TEST key accepts an optional mode mask
438 TEST{0100}=="<is executable file>".
440 Scsi_id now supports a mode without expecting scsi-specific sysfs
441 entries to allow the extraction of cciss-device persistent properties.
447 In the future, we may see uuid's which are just simple character
448 strings (see the DDF Raid Specification). For that reason vol_id now
449 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
450 the creation of symlinks, the *_SAFE values ensure, that no control
451 or whitespace characters are used in the filename.
453 Possible users of libvolume_id, please use the volume_id_get_* functions.
454 The public struct will go away in a future release of the library.
460 Removal of useless extras/eventrecorder.sh.
470 The directory multiplexer for dev.d/ and hotplug.d are finally removed
471 from the udev package.
477 Symlinks can have priorities now, the priority is assigned to the device
478 and specified with OPTIONS="link_priority=100". Devices with higher
479 priorities overwrite the symlinks of devices with lower priorities.
480 If the device that currently owns the link, goes away, the symlink
481 will be removed, and recreated, pointing to the next device with the
482 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
483 more reliable, if multiple devices contain the same metadata and overwrite
486 The dasd_id program is removed from the udev tree, and dasdinfo, with the
487 needed rules, are part of the s390-tools now.
489 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
490 we may get the scsi sysfs mess fixed some day, and this will only catch
491 the devices we are looking for.
493 USB serial numbers for storage devices have the target:lun now appended,
494 to make it possibble to distinguish broken multi-lun devices with all
495 the same SCSI identifiers.
497 Note: The extra "run_directory" which searches and executes stuff in
498 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
499 with the next release. Make sure, that you don't use it anymore, or
500 provides your own implementation of that inefficient stuff.
501 We are tired of reports about a "slow udev", because these directories
502 contain stuff, that runs with _every_ event, instead of using rules,
503 that run programs only for the matching events.
513 DRIVER== will match only for devices that actually have a real
514 driver. DRIVERS== must be used, if parent devices should be
515 included in the match.
517 Libvolume_id's "linux_raid" detection needed another fix.
525 Add additional check to volume_id detection of via_raid, cause
526 some company decided to put a matching pattern all over the empty
527 storage area of their music players.
531 Fix path_id for SAS devices.
535 The udev daemon can be started with --debug-trace now, which will
536 execute all events serialized to get a chance to catch a possible
537 action that crashes the box.
539 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
540 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
541 are excluded from the warning. Referencing parent attributes directly
542 may break when something in the kernel driver model changes. Udev will
543 just find the attribute by walking up the parent chain.
545 Udevtrigger now sorts the list of devices depending on the device
546 dependency, so a "usb" device is triggered after the parent "pci"
551 Revert persistent-storage ata-serial '_' '-' replacement.
557 Udevtrigger can now filter the list of devices to be triggered. Matches
558 for subsystems or sysfs attributes can be specified.
560 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
561 zero-sized files to avoid pointing to /sys and confuse broken tools which
562 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
565 The rules and scripts to create udev rules for persistent network
566 devices and optical drives are in the extras/rules_generator directory
567 now. If you use something similar, please consider replacing your own
568 version with this, to share the support effort. The rule_generator
569 installs its own rules into /etc/udev/rules.d.
571 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
572 the rule_generator depends on cdrom_id to be called in an earlier rule.
578 Renaming of some key names (the old names still work):
579 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
580 (The behavior of the key DRIVER will change soon in one of the next
581 releases, to match only the event device, please switch to DRIVERS
582 instead. If DRIVER is used, it will behave like DRIVERS, but an error
584 With the new key names, we have a more consistent and simpler scheme.
585 We can match the properties of the event device only, with: KERNEL,
586 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
587 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
588 longer mentioned in the man page and should be switched in the rule
591 ATTR{file}="value" can be used now, to write to a sysfs file of the
592 event device. Instead of:
593 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
595 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
597 All the PHYSDEV* keys are deprecated and will be removed from a
599 PHYDEVPATH - is the path of a parent device and should not be
601 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
602 matched with SUBSYSTEMS==
603 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
604 Newer kernels will have DRIVER in the environment,
605 for older kernels udev puts in. Class device will
606 no longer carry this property of a parent and
607 DRIVERS== can be used to match such a parent value.
608 Note that ENV{DRIVER} is only available for a few bus devices, where
609 the driver is already bound at device event time. On coldplug, the
610 events for a lot devices are already bound to a driver, and they will have
611 that value set. But on hotplug, at the time the kernel creates the device,
612 it can't know what driver may claim the device after that, therefore
613 in most cases it will be empty.
615 Failed events should now be re-triggered with:
616 udevtrigger --retry-failed.
617 Please switch to this command, so we keep the details of the /dev/.udev/failed/
618 files private to the udev tools. We may need to switch the current symlink
619 target, cause some obviously broken tools try to scan all files in /dev
620 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
621 million times. This takes ages on slow boxes.
623 The udevinfo attribute walk (-a) now works with giving a device node
624 name (-n) instead of a devpath (-p). The query now always works, also when
625 no database file was created by udev.
627 The built-in /etc/passwd /etc/group parser is removed, we always depend on
628 getpwnam() and getgrnam() now. One of the next releases will depend on
629 fnmatch() and may use getopt_long().
633 Bugfixes and small improvements.
637 Fix path_id for recent kernels.
643 Added support for swapping network interface names, by temporarily
644 renaming the device and wait for the target name to become free.
648 The built-in MODALIAS key and substitution is removed.
652 The binary firmware helper is replaced by the usual simple
653 shell script. Udevsend is removed from the tree.
661 Some more keys require the correct use of '==' and '=' depending
662 on the kind of operation beeing an assignment or a match. Rules
663 with invalid operations are skipped and logged to syslog. Please
664 test with udevtest if the parsing of your rules throws errors and
665 fix possibly broken rules.
669 Provide "udevsettle" to wait for all current udev events to finish.
670 It also watches the current kernel netlink queue by comparing the
671 even sequence number to make sure that there are no current pending
672 events that have not already arrived in the daemon.
676 Fix rule to skip persistent rules for removable IDE devices, which
677 also skipped optical IDE drives.
679 All *_id program are installed in /lib/udev/ by default now.
681 No binary is stripped anymore as this should be done in the
682 packaging process and not at build time.
684 libvolume_id is provided as a shared library now and vol_id is
685 linked against it. Also one of the next HAL versions will require
686 this library, and the HAL build process will also require the
687 header file to be installed. The copy of the same code in HAL will
688 be removed to have only a single copy left on the system.
692 Add persistent links for SCSI tapes. The rules file is renamed
693 to 60-persistent-storage.rules.
695 Create persistent path for usb devices. Can be used for all sorts
696 of devices that can't be distinguished by other properties like
697 multiple identical keyboards and mice connected to the same box.
699 Provide "udevtrigger" program to request events on coldplug. The
700 shell script is much too slow with thousends of devices.
704 Fix persistent disk rules to exclude removable IDE drives.
706 Warn if %e, $modalias or MODALIAS is used.
710 Fix queue export, which wasn't correct for subsequent add/remove
711 events for the same device.
715 Fix cramfs detection on big endian.
717 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
722 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
723 attributes were only checked at the parent device that matched the
724 by BUS requested subsystem. Fix it to also look at the device we
725 received the event for.
727 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
732 Fix a bug where NAME="" would prevent RUN from beeing executed.
734 RUN="/bin/program" does not longer automatically add the subsystem
735 as the first parameter. This is from the days of /sbin/hotplug
736 which is dead now and it's just confusing to need to add a space at
737 the end of the program name to prevent this.
738 If you use rules that need the subsystem as the first parameter,
739 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
740 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
744 The udev man page has moved to udev(7) as it does not describe a command
745 anymore. The programs udev, udevstart and udevsend are no longer installed
746 by default and must be copied manually, if they should be installed or
747 included in a package.
749 Fix a bug where "ignore_device" could run earlier collected RUN keys before
750 the ignore rule was applied.
752 More preparation for future sysfs changes. usb_id and scsi_id no longer
753 depend on a magic order of devices in the /devices chain. Specific devices
754 should be requested by their subsytem.
756 This will always find the scsi parent device without depending on a specific
758 dev = sysfs_device_get(devpath);
759 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
761 The "device" link in the current sysfs layout will be automatically
762 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
763 parent in the devpath. If a device is requested by it's symlink, like all
764 class devices in the new sysfs layout will look like, it gets automatically
765 resolved and substituted with the real devpath and not the symlink path.
768 A similar logic must be applied to _all_ sysfs users, including
769 scripts, that search along parent devices in sysfs. The explicit use of
770 the "device" link must be avoided. With the future sysfs layout all
771 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
772 back to the "class" or the "bus". The layout of the parent devices in
773 /devices is not necessarily expected to be stable across kernel releases and
774 searching for parents by their subsystem should make sysfs users tolerant
775 for changed parent chains.
779 Prepare udev to work with the experimental kernel patch, that moves
780 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
782 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
783 moving the class devices to /sys/devices.
785 Thanks again to Marco for help finding a hopefully nice compromise
786 to make %b simpler and working again.
790 Complete removal of libsysfs, replaced by simple helper functions
791 which are much simpler and a bit faster. The udev daemon operatesentirely
792 on event parameters and does not use sysfs for simple rules anymore.
793 Please report any new bugs/problems, that may be caused by this big
794 change. They will be fixed immediately.
796 The enumeration format character '%e' is deprecated and will be
797 removed sometimes from a future udev version. It never worked correctly
798 outside of udevstart, so we can't use it with the new parallel
799 coldplug. A simple enumeration is as useless as the devfs naming
800 scheme, just get rid of both if you still use it.
802 MODALIAS and $modalias is not needed and will be removed from one of
803 the next udev versions, replace it in all rules with ENV{MODALIAS} or
804 the sysfs "modalias" value.
806 Thanks a lot to Marco for all his help on finding and fixing bugs.
810 Let scsi_id request libata drive serial numbers from page 0x80.
812 Renamed etc/udev/persistent.rules to persistent-disk.rules and
813 added /dev/disk/by-name/* for device mapper device names.
815 Removed %e from the man page. It never worked reliably outside
816 of udevstart and udevstart is no longer recommended to use.
820 Symlinks are now exported to the event environment. Hopefully it's no
821 longer needed to run udevinfo from an event process, like it was
822 mentioned on the hotplug list:
823 UDEV [1134776873.702967] add@/block/sdb
826 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
830 Fix a problem if udevsend is used as the hotplug handler and tries to use
831 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
832 and this kind of problems will hopefully go away soon.
836 All built-in logic to work around bad sysfs timing is removed with this
837 version. The need to wait for sysfs files is almost fixed with a kernel
838 version that doesn't work with this udev version anyway. Until we fix
839 the timing of the "bus" link creation, the former integrated logic should
840 be emulated by a rule placed before all other rules:
841 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
843 The option "udev_db" does no longer exist. All udev state will be in
844 /$udev_root/.udev/ now, there is no longer an option to set this
846 If the init script or something else used this value, just depend on
847 this hardcoded path. But remember _all_content_ of this directory is
848 still private to udev and can change at any time.
850 Default location for rule sripts and helper programs is now: /lib/udev/.
851 Everything that is not useful on the commandline should go into this
852 directory. Some of the helpers in the extras folder are installed there
853 now. The rules need to be changed, to find the helpers there.
855 Also /lib/udev/devices is recommended as a directory where packages or
856 the user can place real device nodes, which get copied over to /dev at
857 every boot. This should replace the various solutions with custom config
860 Udevsend does no longer start the udev daemon. This must be done with
861 the init script that prepares /dev on tmpfs and creates the initial nodes,
862 before starting the daemon.
866 Silent a too verbose error logging for the old hotplug.d/ dev.d/
869 The copy of klibc is removed. A systemwide installed version of klibc
870 should be used to build a klibc udev now.
874 NAME="" will not create any nodes, but execute RUN keys. To completely
875 ignore an event the OPTION "ignore_device" should be used.
877 After removal of the reorder queue, events with a TIMEOUT can be executed
878 without any queuing now.
882 Fixed bug in udevd, if inotify is not available. We depend on netlink
883 uevents now, kernels without that event source will not work with that
884 version of udev anymore.
888 The rule parsing happens now in the daemon once at startup, all udev
889 event processes inherit the already parsed rules from the daemon.
890 It is shipped with SUSE10.0 and reduces heavily the system load at
891 startup. The option to save precompiled rules and let the udev process
892 pick the them up is removed, as it's no longer needed.
894 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
895 device. Libsysfs is changed to "translate" the requested link into the
896 real device path, as it would happen with the hotplug event. Otherwise
897 device removal and the udev database will not work.
899 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
902 A few improvements for vol_id, the filesytem probing code.
906 Fix a stupid typo in extras/run_directory for "make install".
908 scsi_id creates the temporary devnode now in /dev for usage with a
909 non-writable /tmp directory.
911 The uevent kernel socket buffer can carry app. 50.000 events now,
912 let's see who can break this again. :)
914 The upcoming kernel will have a new input driver core integration.
915 Some class devices are now symlinks to the real device. libsysfs
916 needs a fix for this to work correctly. Udevstart of older udev
917 versions will _not_ create these devices!
921 Fix a 'install' target in the Makefile, that prevents EXTRAS from
926 A bunch of mostly trivial bugfixes. From now on no node name or
927 symlink name can contain any character than plain whitelisted ascii
928 characters or validated utf8 byte-streams. This is needed for the
929 /dev/disk/by-label/* links, because we import untrusted data and
930 export it to the filesystem.
934 More bugfixes. If udevd was started from the kernel, we don't
935 have stdin/stdout/stderr, which broke the forked tools in some
940 Bugfix. udevstart event ordering was broken for a long time.
941 The new run_program() uncovered it, because /dev/null was not
942 available while we try to run external programs.
943 Now udevstart should create it before we run anything.
947 Minor bugfixes and some distro rules updates. If you don't have the
948 persistent disk rules in /dev/disk/by-*/* on your distro, just
949 grab it from here. :)
953 We can use socket communication now to pass events from udev to
955 RUN+="socket:/org/freedesktop/hal/udev_event"
956 will pass the whole udev event to the HAL daemon without the need
957 for a forked helper. (See ChangeLog for udevmonitor, as an example)
961 Mostly bugfixes and see ChangeLog.
963 The test for the existence of an environment value should be
965 ENV{KEY}=="*" to ENV{KEY}=="?*"
966 because "*" will not fail anymore, if the key does not exist or
971 Bugfixes and a few tweaks described in the ChangeLog.
975 Mostly a Bugfix release.
977 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
978 timing with custom rules.
982 We changed the internal rule storage format. Our large rule files took
983 2 MB of RAM, with the change we are down to 99kB.
985 If the device-node has been created with default name and no symlink or
986 options are to remenber, it is not longer stored in the udevdb. HAL will
987 need to be updated to work correctly with that change.
989 To overrride optimization flags, OPTFLAGS may be used now.
997 Major changes happened with this release. The goal is to take over the
998 complete kernel-event handling and provide a more efficient way to dispatch
999 kernel events. Replacing most of the current shell script logic and the
1000 kernel forked helper with a netlink-daemon and a rule-based event handling.
1002 o udevd listens to netlink events now. The first valid netlink event
1003 will make udevd ignore any message from udevsend that contains a
1004 SEQNUM, to avoid duplicate events. The forked events can be disabled
1006 echo "" > /proc/sys/kernel/hotplug
1007 For full support, the broken input-subsytem needs to be fixed, not to
1008 bypass the driver core.
1010 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1011 removed from udev itself and must be emulated by calling small
1012 helper binaries provided in the extras folder:
1013 make EXTRAS=extras/run_directory/
1014 will build udev_run_devd and udev_run_hotplugd, which can be called
1015 from a rule if needed:
1016 RUN+="/sbin/udev_run_hotplugd"
1017 The recommended way to handle this is to convert all the calls from
1018 the directories to explicit udev rules and get completely rid of the
1019 multiplexing. (To catch a ttyUSB event, you now no longer need to
1020 fork and exit 300 tty script instances you are not interested in, it
1021 is just one rule that matches exactly the device.)
1023 o udev handles now _all_ events not just events for class and block
1024 devices, this way it is possible to control the complete event
1025 behavior with udev rules. Especially useful for rules like:
1026 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1028 o As used in the modalias rule, udev supports now textual
1029 substitution placeholder along with the usual format chars. This
1030 needs to be documented, for now it's only visible in udev_rules_parse.c.
1032 o The rule keys support now more operations. This is documented in the
1033 man page. It is possible to add values to list-keys like the SYMLINK
1034 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1035 Also "final"-assignments are supported by using KEY:="value", which will
1036 prevent changing the key by any later rule.
1038 o kernel 2.6.12 has the "detached_state" attribute removed from
1039 sysfs, which was used to recognize sysfs population. We switched that
1040 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1041 Running this udev version on older kernels may cause a short delay for
1044 o To provide infrastructure for persistent device naming, the id programs:
1045 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1046 to export the probed data in environment key format:
1047 pim:~ # /sbin/ata_id --export /dev/hda
1048 ID_MODEL=HTS726060M9AT00
1049 ID_SERIAL=MRH401M4G6UM9B
1050 ID_REVISION=MH4OA6BA
1052 The following rules:
1053 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1054 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1057 kay@pim:~> tree /dev/disk
1060 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1061 | `-- IBM-Memory_Key -> ../../sda
1063 | |-- swap -> ../../hda1
1064 | |-- date -> ../../sda1
1065 | `-- home -> ../../hda3
1067 |-- 2E08712B0870F2E7 -> ../../hda3
1068 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1069 |-- E845-7A89 -> ../../sda1
1070 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1072 The IMPORT= operation will import these keys in the environment and make
1073 it available for later PROGRAM= and RUN= executed programs. The keys are
1074 also stored in the udevdb and can be queried from there with one of the
1077 o A few binaries are silently added to the repository, which can be used
1078 to replay kernel events from initramfs instead of using coldplug. udevd
1079 can be instructed now to queue-up events while the stored events from
1080 initramfs are filled into the udevd-queue. This code is still under
1081 development and there is no documentation now besides the code itself.
1082 The additional binaries get compiled, but are not installed by default.
1084 o There is also a temporary fix for a performance problem where too many
1085 events happen in parallel and every event needs to parse the rules.
1086 udev can now read precompiled rules stored on disk. This is likely to be
1087 replaced by a more elegant solution in a future udev version.
1091 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1092 Fix for libsysfs not to expect this file was added.
1096 All rules are applied now, but only the first matching rule with a NAME-key
1097 will be applied. All later rules with NAME-key are completely ignored. This
1098 way system supplied symlinks or permissions gets applied to user-defined
1102 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1103 to some rules, to keep the old behavior.
1105 The rules are read on "remove"-events too. That makes is possible to match
1106 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1107 instruct udev to ignore an event (OPTIONS="ignore_device").
1108 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1110 The new RUN-key supports rule-based execution of programs after device-node
1111 handling. This is meant as a general replacement for the dev.d/-directories
1112 to give fine grained control over the execution of programs.
1114 The %s{}-sysfs format char replacement values are searched at any of the
1115 devices in the device chain now, not only at the class-device.
1117 We support log priority levels now. The value udev_log in udev.conf is used
1118 to determine what is printed to syslog. This makes it possible to
1119 run a version with compiled-in debug messages in a production environment
1120 which is sometimes needed to find a bug.
1121 It is still possible to supress the inclusion of _any_ syslog usage with
1122 USE_LOG=false to create the smallest possible binaries if needed.
1123 The configured udev_log value can be overridden with the environment variable
1128 Possible use of a system-wide klibc:
1129 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1130 will link against an external klibc and our own version will be ignored.
1134 We support an unlimited count of symlinks now.
1136 If USE_STATIC=true is passed to a glibc build, we link statically and use
1137 a built-in userdb parser to resolve user and group names.
1139 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1140 we walk up the chain of physical devices to find a match.
1142 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1143 easy to skip certain attribute matches without composing rules with weird
1144 character class negations like:
1145 KERNEL="[!s][!c][!d]*"
1146 this can now be replaced with:
1148 The current simple '=' is still supported, and should work as it does today,
1149 but existing rules should be converted if possible, to be better readable.
1151 We have new ENV{}== key now, to match against a maximum of 5 environment
1154 udevstart is its own binary again, because we don't need co carry this araound
1155 with every forked event.
~ianmdlvl / elogind.git / blob