8 The configure options have changed because another library needs to be
9 installed in a different location. Instead of exec_prefix and udev_prefix,
10 libdir, rootlibdir and libexecdir are used. The Details are explained in
13 Event processes now get re-used after they handled an event. This reduces
14 the number of forks and the pressure on the CPU significantly, because
15 cloned event processes no longer cause page faults in the main daemon.
16 After the events have settled, a few worker processes stay around for
17 future events, all others get cleaned up.
19 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
20 Also inotify support is mandatory now to run udev.
22 The format of the queue exported by the udev damon has changed. There is
23 no longer a /dev/.udev/queue/ directory. The current event queue can be
24 accessed with udevadm settle and libudedv.
26 Libudev does not have the unstable API header anymore. From now on,
27 incompatible changes will be handled by bumping the library major version.
29 To build udev from the git tree gtk-doc is needed now. The tarballs will
30 build without it and contain the pre-built documentation. An online copy
32 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
34 The tools from the udev-extras repository have been merged into the main
35 udev repository. Some of the extras have larger external dependencies, and
36 they can be disabled with the configure switch --disable-extras.
42 The program vol_id and the library libvolume_id are removed from the
43 repository. Libvolume_id is merged with libblkid from the util-linux-ng
44 package. Persistent disk links for label and uuid depend on the
45 util-linux-ng version (2.15) of blkid now. Older versions of blkid
46 can not be used with udev.
48 Libudev allows to subscribe to udev events. To prevent unwanted messages
49 to be delivered, and waking up the subscribing process, a filter can be
50 installed, to drop messages inside a kernel socket filter. The filters
51 match on the <subsytem>:<devtype> properties of the device.
52 This is part of the ongoing effort to replace HAL, and switch current
53 users over to directly use libudev.
54 Libudev is still marked as experimental, and its interface might
55 eventually change if needed, but no major changes of the currently exported
56 interface are expected anymore, and a first stable release should happen
59 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
60 is not supported since while and udevd will log an error message at
61 startup. It should still be able to boot-up, but advanced rules and system
62 services which depend on the information not available in the old sysfs
63 format will fail to work correctly.
65 DVB device naming is supplied by the kernel now. In case older kernels
66 need to be supported, the old shell script should be added to a compat
73 The processed udev events get send back to the netlink socket. Libudev
74 provides access to these events. This is work-in-progress, to replace
75 the DeviceKit daemon functionality directly with libudev. There are
76 upcoming kernel changes to allow non-root users to subcribe to these
83 "udevadm settle" now optionally accepts a range of events to wait for,
84 instead of waiting for "all" events.
90 The installed watch for block device metadata changes is now removed
91 during event hadling, because some (broken) tools may be called from udev
92 rules and (wrongly) open the device with write access. After the finished
93 event handling the watch is restored.
99 Device nodes can be watched for changes with inotify with OPTIONS="watch".
100 If closed after being opened for writing, a "change" uevent will occur.
101 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
107 The udevadm test command has no longer a --force option, nodes and symlinks
108 are always updated with a test run now.
110 The udevd daemon can be started with --resolve-names=never to avoid all user
111 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
112 lookup user and groups every time events are handled.
118 We are currently merging the Ubuntu rules in the udev default rules,
119 and get one step closer to provide a common Linux /dev setup, regarding
120 device names, symlinks, and default device permissions. On udev startup,
121 we now expect the following groups to be resolvable to their ids with
123 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
124 LDAP setups need to make sure, that these groups are always resolvable at
125 bootup, with only the rootfs mounted, and without network access available.
127 Some systems may need to add some new, currently not used groups, or need
128 to add some users to new groups, but the cost of this change is minimal,
129 compared to the pain the current, rather random, differences between the
130 various distributions cause for upstream projects and third-party vendors.
132 In general, "normal" users who log into a machine should never be a member
133 of any such group, but the device-access should be managed by dynamic ACLs,
134 which get added and removed for the specific users on login/logout and
135 session activity/inactivity. These groups are only provided for custom setups,
136 and mainly system services, to allow proper privilege separation.
137 A video-streaming daemon uid would be a member of "audio" and "video", to get
138 access to the sound and video devices, but no "normal" user should ever belong
139 to the "audio" group, because he could listen to the built-in microphone with
140 any ssh-session established from the other side of the world.
142 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
143 which do not depend on the kernel device name. As usual, unique
144 devices - only a single one per product connected, or a real
145 USB serial number in the device - are always found with the same
146 name in the by-id/ directory.
147 Completely identical devices may overwrite their names in by-id/
148 and can only be found reliably in the by-path/ directory. Devices
149 specified by by-path/ must not change their connection, like the
150 USB port number they are plugged in, to keep their name.
152 To support some advanced features, Linux 2.6.22 is the oldest supported
153 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
154 supported. Older kernels should still work, and devices nodes should be
155 reliably created, but some rules and libudev will not work correctly because
156 the old kernels do not provide the expected information or interfaces.
162 Fix for a possible segfault while swapping network interface names in udev
169 The group "video" is part of the default rules now.
173 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
174 block devices in some cases. No common distro uses this option anymore,
175 and we do not get enough testing for this and recent udev versions. If
176 this option is not needed to run some old distro with a new kernel,
177 it should be disabled in the kernel config.
179 Bugfix for the $links substitution variable, which may crash if no links
180 are created. This should not happen in usual setups because we always
181 create /dev/{block,char}/ links.
183 The strings of the parsed rules, which are kept in memory, no longer
184 contain duplicate entries, or duplicate tails of strings. This, and the
185 new rules parsing/matching code reduces the total in-memory size of
186 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
189 The export of DEVTYPE=disk/partition got removed from the default
190 rules. This value is available from the kernel. The pnp shell script
191 modprobe hack is removed from the default rules. ACPI devices have _proper_
192 modalias support and take care of the same functionality.
193 Installations which support old kernels, but install current default
194 udev rules may want to add that to the compat rules file.
196 Libvolume_id now always probes for all known filesystems, and does not
197 stop at the first match. Some filesystems are marked as "exclusive probe",
198 and if any other filesytem type matches at the same time, libvolume_id
199 will, by default, not return any probing result. This is intended to prevent
200 mis-detection with conflicting left-over signatures found from earlier
201 file system formats. That way, we no longer depend on the probe-order
202 in case of multiple competing signatures. In some setups the kernel allows
203 to mount a volume with just the old filesystem signature still in place.
204 This may damage the new filesystem and cause data-loss, just by mounting
205 it. Because volume_id can not decide which one the correct signature is,
206 the wrong signatures need to be removed manually from the volume, or the
207 volume needs to be reformatted, to enable filesystem detection and possible
212 Fix segfault if compiled without optimization and dbg() does not get
213 compiled out and uses variables which are not available.
217 Bugfixes. (And maybe new bugs. :))
219 The rule matching engine got converted from a rule list to a token
220 array which reduced the in-memory rules representation of a full
221 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
222 Limits like 5 ENV and ATTR matches, and one single instance for most
223 other keys per rule are gone.
225 The NAME assignment is no longer special cased. If later rules assign
226 a NAME value again, the former value will be overwritten. As usual
227 for most other keys, the NAME value can be protected by doing a final
228 assignment with NAME:="<value>".
230 All udev code now uses libudev, which is also exported. The library
231 is still under development, marked as experimental, and its interface
232 may change as long as the DeviceKit integration is not finished.
234 Many thanks to Alan Jenkins for his continuous help, and finding and
235 optimizing some of the computing expensive parts.
241 Kernel devices and device nodes are connected now by reverse indizes in
242 /sys and /dev. A device number retrieved by a stat() or similar, the
243 kernel device directory can be found by looking up:
244 /sys/dev/{block,char}/<maj>:<min>
245 and the device node of the same device by looking up:
246 /dev/{block,char}/<maj>:<min>
250 Fix recently introduced bug, which caused a compilation without large
251 file support, where vol_id does not recognize raid signatures at the end
254 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
255 Seems some kernel versions prevent the creation of the ieee-* links,
256 so people used the scsi-* link which disappeared now.
258 More libudev work. Almost all udevadm functionality comes from libudev
261 udevadm trigger has a new option --type, which allows to trigger events
262 for "devices", for "subsystems", or "failed" devices. The old option
263 --retry-failed" still works, but is no longer mentioned in the man page.
269 The udevadm info --device-id-of-file= output has changed to use
270 the obvious format. Possible current users should use the --export
271 option which is not affected.
273 The old udev commands symlinks to udevadm are not installed, if
274 these symlinks are used, a warning is printed.
280 Optical drive's media is no longer probed for raid signatures,
281 reading the end of the device causes some devices to malfunction.
282 Also the offset of the last session found is used now to probe
285 The volume_id library got a major version number update to 1,
286 some deprecated functions are removed.
288 A shared library "libudev" gets installed now to provide access
289 to udev device information. DeviceKit, the successor of HAL, will
290 need this library to access the udev database and search sysfs for
292 The library is currently in an experimental state, also the API is
293 expected to change, as long as the DeviceKit integration is not
298 We use ./configure now. See INSTALL for details. Current
301 "/usr" - prefix for man pages, include files
303 "" - the root filesystem, prefix for libs and binaries
307 "lib" - directory name for libraries, not a path name
308 multilib 64bit systems may use "lib64" instead of "lib"
310 compile-in verbose debug messages
312 disable all logging and compile-out all log strings
314 link against SELInux libraries, to set the expected context
317 In the default rules, the group "disk" gets permissions 0660 instead
318 of 0640. One small step closer to unify distro rules. Some day, all
319 distros hopefully end up with the same set of rules.
321 No symlinks to udevadm are installed anymore, if they are still needed,
322 they should be provided by the package.
328 Default udev rules, which are not supposed to be edited by the user, should
329 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
330 the udev package and will be replaced with an update. Udev will pick up rule
332 /lib/udev/rules.d/ - default installed rules
333 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
334 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
335 It does not matter in which directory a rule file lives, all files are sorted
338 To help creating /dev/root, we have now:
339 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
342 In case the current --device-id-of-file is already used, please switch to
343 the --export format version, it saves the output parsing and the old
344 format will be changed to use ':' as a separator, like the format in the
349 Fix cdrom_id to properly recognize blank media.
355 Tape drive id-data is queried from /dev/bsg/* instead of the tape
356 nodes. This avoids rewinding tapes on open().
362 The symlinks udevcontrol and udevtrigger are no longer installed by
365 The scsi_id program does not depend on sysfs anymore. It can speak
366 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
367 data, which should solve some old problems with tape devices, where
368 we better do not open all tape device nodes to identify the device.
374 The cdrom_id program is replaced by an advanced version, which can
375 detect most common device types, and also properties of the inserted
376 media. This is part of moving some basic functionality from HAL into
377 udev (and the kernel).
383 The last WAIT_FOR_SYSFS rule is removed from the default rules.
385 The symlinks to udevadm for the debugging tools: udevmonitor and
386 udevtest are no longer created.
388 The symlinks to the udevadm man page for the old tool names are
391 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
392 should be prefixed with '@' to indicate that the path is not a
403 Udevstart is removed from the tree, it did not get installed for
404 a long time now, and is long replaced by trigger and settle.
410 All udev tools are merged into a single binary called udevadm.
411 The old names of the tools are built-in commands in udevadm now.
412 Symlinks to udevadm, with the names of the old tools, provide
413 the same functionality as the standalone tools. There is also
414 only a single udevadm.8 man page left for all tools.
416 Tools like mkinitramfs should be checked, if they need to include
417 udevadm in the list of files.
427 The etc/udev/rules.d/ directory now contains a default set of basic
428 udev rules. This initial version is the result of a rules file merge
429 of Fedora and openSUSE. For these both distros only a few specific
430 rules are left in their own file, named after the distro. Rules which
431 are optionally installed, because they are only valid for a specific
432 architecture, or rules for subsystems which are not always used are
433 in etc/udev/packages/.
439 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
440 actions by dynamically created rules.
442 SYMLINK=="<value>" matches agains the entries in the list of
443 currently defined symlinks. The links are not created in the
444 filesystem at that point in time, but the values can be matched.
446 RUN{ignore_error}+="<program>" will ignore any exit code from the
447 program and not record as a failed event.
453 Final merge of patches/features from the Ubuntu package.
459 Control characters in filesystem label strings are no longer silenty
460 removed, but hex-encoded, to be able to uniquely identify the device
461 by its symlink in /dev/disk/by-label/.
462 If libvolume_id is used by mount(8), LABEL= will work as expected,
463 if slashes or other characters are used in the label string.
465 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
466 can be specified now. The TEST key accepts an optional mode mask
467 TEST{0100}=="<is executable file>".
469 Scsi_id now supports a mode without expecting scsi-specific sysfs
470 entries to allow the extraction of cciss-device persistent properties.
476 In the future, we may see uuid's which are just simple character
477 strings (see the DDF Raid Specification). For that reason vol_id now
478 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
479 the creation of symlinks, the *_SAFE values ensure, that no control
480 or whitespace characters are used in the filename.
482 Possible users of libvolume_id, please use the volume_id_get_* functions.
483 The public struct will go away in a future release of the library.
489 Removal of useless extras/eventrecorder.sh.
499 The directory multiplexer for dev.d/ and hotplug.d are finally removed
500 from the udev package.
506 Symlinks can have priorities now, the priority is assigned to the device
507 and specified with OPTIONS="link_priority=100". Devices with higher
508 priorities overwrite the symlinks of devices with lower priorities.
509 If the device that currently owns the link, goes away, the symlink
510 will be removed, and recreated, pointing to the next device with the
511 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
512 more reliable, if multiple devices contain the same metadata and overwrite
515 The dasd_id program is removed from the udev tree, and dasdinfo, with the
516 needed rules, are part of the s390-tools now.
518 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
519 we may get the scsi sysfs mess fixed some day, and this will only catch
520 the devices we are looking for.
522 USB serial numbers for storage devices have the target:lun now appended,
523 to make it possibble to distinguish broken multi-lun devices with all
524 the same SCSI identifiers.
526 Note: The extra "run_directory" which searches and executes stuff in
527 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
528 with the next release. Make sure, that you don't use it anymore, or
529 provides your own implementation of that inefficient stuff.
530 We are tired of reports about a "slow udev", because these directories
531 contain stuff, that runs with _every_ event, instead of using rules,
532 that run programs only for the matching events.
542 DRIVER== will match only for devices that actually have a real
543 driver. DRIVERS== must be used, if parent devices should be
544 included in the match.
546 Libvolume_id's "linux_raid" detection needed another fix.
554 Add additional check to volume_id detection of via_raid, cause
555 some company decided to put a matching pattern all over the empty
556 storage area of their music players.
560 Fix path_id for SAS devices.
564 The udev daemon can be started with --debug-trace now, which will
565 execute all events serialized to get a chance to catch a possible
566 action that crashes the box.
568 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
569 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
570 are excluded from the warning. Referencing parent attributes directly
571 may break when something in the kernel driver model changes. Udev will
572 just find the attribute by walking up the parent chain.
574 Udevtrigger now sorts the list of devices depending on the device
575 dependency, so a "usb" device is triggered after the parent "pci"
580 Revert persistent-storage ata-serial '_' '-' replacement.
586 Udevtrigger can now filter the list of devices to be triggered. Matches
587 for subsystems or sysfs attributes can be specified.
589 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
590 zero-sized files to avoid pointing to /sys and confuse broken tools which
591 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
594 The rules and scripts to create udev rules for persistent network
595 devices and optical drives are in the extras/rules_generator directory
596 now. If you use something similar, please consider replacing your own
597 version with this, to share the support effort. The rule_generator
598 installs its own rules into /etc/udev/rules.d.
600 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
601 the rule_generator depends on cdrom_id to be called in an earlier rule.
607 Renaming of some key names (the old names still work):
608 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
609 (The behavior of the key DRIVER will change soon in one of the next
610 releases, to match only the event device, please switch to DRIVERS
611 instead. If DRIVER is used, it will behave like DRIVERS, but an error
613 With the new key names, we have a more consistent and simpler scheme.
614 We can match the properties of the event device only, with: KERNEL,
615 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
616 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
617 longer mentioned in the man page and should be switched in the rule
620 ATTR{file}="value" can be used now, to write to a sysfs file of the
621 event device. Instead of:
622 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
624 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
626 All the PHYSDEV* keys are deprecated and will be removed from a
628 PHYDEVPATH - is the path of a parent device and should not be
630 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
631 matched with SUBSYSTEMS==
632 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
633 Newer kernels will have DRIVER in the environment,
634 for older kernels udev puts in. Class device will
635 no longer carry this property of a parent and
636 DRIVERS== can be used to match such a parent value.
637 Note that ENV{DRIVER} is only available for a few bus devices, where
638 the driver is already bound at device event time. On coldplug, the
639 events for a lot devices are already bound to a driver, and they will have
640 that value set. But on hotplug, at the time the kernel creates the device,
641 it can't know what driver may claim the device after that, therefore
642 in most cases it will be empty.
644 Failed events should now be re-triggered with:
645 udevtrigger --retry-failed.
646 Please switch to this command, so we keep the details of the /dev/.udev/failed/
647 files private to the udev tools. We may need to switch the current symlink
648 target, cause some obviously broken tools try to scan all files in /dev
649 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
650 million times. This takes ages on slow boxes.
652 The udevinfo attribute walk (-a) now works with giving a device node
653 name (-n) instead of a devpath (-p). The query now always works, also when
654 no database file was created by udev.
656 The built-in /etc/passwd /etc/group parser is removed, we always depend on
657 getpwnam() and getgrnam() now. One of the next releases will depend on
658 fnmatch() and may use getopt_long().
662 Bugfixes and small improvements.
666 Fix path_id for recent kernels.
672 Added support for swapping network interface names, by temporarily
673 renaming the device and wait for the target name to become free.
677 The built-in MODALIAS key and substitution is removed.
681 The binary firmware helper is replaced by the usual simple
682 shell script. Udevsend is removed from the tree.
690 Some more keys require the correct use of '==' and '=' depending
691 on the kind of operation beeing an assignment or a match. Rules
692 with invalid operations are skipped and logged to syslog. Please
693 test with udevtest if the parsing of your rules throws errors and
694 fix possibly broken rules.
698 Provide "udevsettle" to wait for all current udev events to finish.
699 It also watches the current kernel netlink queue by comparing the
700 even sequence number to make sure that there are no current pending
701 events that have not already arrived in the daemon.
705 Fix rule to skip persistent rules for removable IDE devices, which
706 also skipped optical IDE drives.
708 All *_id program are installed in /lib/udev/ by default now.
710 No binary is stripped anymore as this should be done in the
711 packaging process and not at build time.
713 libvolume_id is provided as a shared library now and vol_id is
714 linked against it. Also one of the next HAL versions will require
715 this library, and the HAL build process will also require the
716 header file to be installed. The copy of the same code in HAL will
717 be removed to have only a single copy left on the system.
721 Add persistent links for SCSI tapes. The rules file is renamed
722 to 60-persistent-storage.rules.
724 Create persistent path for usb devices. Can be used for all sorts
725 of devices that can't be distinguished by other properties like
726 multiple identical keyboards and mice connected to the same box.
728 Provide "udevtrigger" program to request events on coldplug. The
729 shell script is much too slow with thousends of devices.
733 Fix persistent disk rules to exclude removable IDE drives.
735 Warn if %e, $modalias or MODALIAS is used.
739 Fix queue export, which wasn't correct for subsequent add/remove
740 events for the same device.
744 Fix cramfs detection on big endian.
746 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
751 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
752 attributes were only checked at the parent device that matched the
753 by BUS requested subsystem. Fix it to also look at the device we
754 received the event for.
756 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
761 Fix a bug where NAME="" would prevent RUN from beeing executed.
763 RUN="/bin/program" does not longer automatically add the subsystem
764 as the first parameter. This is from the days of /sbin/hotplug
765 which is dead now and it's just confusing to need to add a space at
766 the end of the program name to prevent this.
767 If you use rules that need the subsystem as the first parameter,
768 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
769 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
773 The udev man page has moved to udev(7) as it does not describe a command
774 anymore. The programs udev, udevstart and udevsend are no longer installed
775 by default and must be copied manually, if they should be installed or
776 included in a package.
778 Fix a bug where "ignore_device" could run earlier collected RUN keys before
779 the ignore rule was applied.
781 More preparation for future sysfs changes. usb_id and scsi_id no longer
782 depend on a magic order of devices in the /devices chain. Specific devices
783 should be requested by their subsytem.
785 This will always find the scsi parent device without depending on a specific
787 dev = sysfs_device_get(devpath);
788 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
790 The "device" link in the current sysfs layout will be automatically
791 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
792 parent in the devpath. If a device is requested by it's symlink, like all
793 class devices in the new sysfs layout will look like, it gets automatically
794 resolved and substituted with the real devpath and not the symlink path.
797 A similar logic must be applied to _all_ sysfs users, including
798 scripts, that search along parent devices in sysfs. The explicit use of
799 the "device" link must be avoided. With the future sysfs layout all
800 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
801 back to the "class" or the "bus". The layout of the parent devices in
802 /devices is not necessarily expected to be stable across kernel releases and
803 searching for parents by their subsystem should make sysfs users tolerant
804 for changed parent chains.
808 Prepare udev to work with the experimental kernel patch, that moves
809 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
811 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
812 moving the class devices to /sys/devices.
814 Thanks again to Marco for help finding a hopefully nice compromise
815 to make %b simpler and working again.
819 Complete removal of libsysfs, replaced by simple helper functions
820 which are much simpler and a bit faster. The udev daemon operatesentirely
821 on event parameters and does not use sysfs for simple rules anymore.
822 Please report any new bugs/problems, that may be caused by this big
823 change. They will be fixed immediately.
825 The enumeration format character '%e' is deprecated and will be
826 removed sometimes from a future udev version. It never worked correctly
827 outside of udevstart, so we can't use it with the new parallel
828 coldplug. A simple enumeration is as useless as the devfs naming
829 scheme, just get rid of both if you still use it.
831 MODALIAS and $modalias is not needed and will be removed from one of
832 the next udev versions, replace it in all rules with ENV{MODALIAS} or
833 the sysfs "modalias" value.
835 Thanks a lot to Marco for all his help on finding and fixing bugs.
839 Let scsi_id request libata drive serial numbers from page 0x80.
841 Renamed etc/udev/persistent.rules to persistent-disk.rules and
842 added /dev/disk/by-name/* for device mapper device names.
844 Removed %e from the man page. It never worked reliably outside
845 of udevstart and udevstart is no longer recommended to use.
849 Symlinks are now exported to the event environment. Hopefully it's no
850 longer needed to run udevinfo from an event process, like it was
851 mentioned on the hotplug list:
852 UDEV [1134776873.702967] add@/block/sdb
855 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
859 Fix a problem if udevsend is used as the hotplug handler and tries to use
860 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
861 and this kind of problems will hopefully go away soon.
865 All built-in logic to work around bad sysfs timing is removed with this
866 version. The need to wait for sysfs files is almost fixed with a kernel
867 version that doesn't work with this udev version anyway. Until we fix
868 the timing of the "bus" link creation, the former integrated logic should
869 be emulated by a rule placed before all other rules:
870 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
872 The option "udev_db" does no longer exist. All udev state will be in
873 /$udev_root/.udev/ now, there is no longer an option to set this
875 If the init script or something else used this value, just depend on
876 this hardcoded path. But remember _all_content_ of this directory is
877 still private to udev and can change at any time.
879 Default location for rule sripts and helper programs is now: /lib/udev/.
880 Everything that is not useful on the commandline should go into this
881 directory. Some of the helpers in the extras folder are installed there
882 now. The rules need to be changed, to find the helpers there.
884 Also /lib/udev/devices is recommended as a directory where packages or
885 the user can place real device nodes, which get copied over to /dev at
886 every boot. This should replace the various solutions with custom config
889 Udevsend does no longer start the udev daemon. This must be done with
890 the init script that prepares /dev on tmpfs and creates the initial nodes,
891 before starting the daemon.
895 Silent a too verbose error logging for the old hotplug.d/ dev.d/
898 The copy of klibc is removed. A systemwide installed version of klibc
899 should be used to build a klibc udev now.
903 NAME="" will not create any nodes, but execute RUN keys. To completely
904 ignore an event the OPTION "ignore_device" should be used.
906 After removal of the reorder queue, events with a TIMEOUT can be executed
907 without any queuing now.
911 Fixed bug in udevd, if inotify is not available. We depend on netlink
912 uevents now, kernels without that event source will not work with that
913 version of udev anymore.
917 The rule parsing happens now in the daemon once at startup, all udev
918 event processes inherit the already parsed rules from the daemon.
919 It is shipped with SUSE10.0 and reduces heavily the system load at
920 startup. The option to save precompiled rules and let the udev process
921 pick the them up is removed, as it's no longer needed.
923 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
924 device. Libsysfs is changed to "translate" the requested link into the
925 real device path, as it would happen with the hotplug event. Otherwise
926 device removal and the udev database will not work.
928 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
931 A few improvements for vol_id, the filesytem probing code.
935 Fix a stupid typo in extras/run_directory for "make install".
937 scsi_id creates the temporary devnode now in /dev for usage with a
938 non-writable /tmp directory.
940 The uevent kernel socket buffer can carry app. 50.000 events now,
941 let's see who can break this again. :)
943 The upcoming kernel will have a new input driver core integration.
944 Some class devices are now symlinks to the real device. libsysfs
945 needs a fix for this to work correctly. Udevstart of older udev
946 versions will _not_ create these devices!
950 Fix a 'install' target in the Makefile, that prevents EXTRAS from
955 A bunch of mostly trivial bugfixes. From now on no node name or
956 symlink name can contain any character than plain whitelisted ascii
957 characters or validated utf8 byte-streams. This is needed for the
958 /dev/disk/by-label/* links, because we import untrusted data and
959 export it to the filesystem.
963 More bugfixes. If udevd was started from the kernel, we don't
964 have stdin/stdout/stderr, which broke the forked tools in some
969 Bugfix. udevstart event ordering was broken for a long time.
970 The new run_program() uncovered it, because /dev/null was not
971 available while we try to run external programs.
972 Now udevstart should create it before we run anything.
976 Minor bugfixes and some distro rules updates. If you don't have the
977 persistent disk rules in /dev/disk/by-*/* on your distro, just
978 grab it from here. :)
982 We can use socket communication now to pass events from udev to
984 RUN+="socket:/org/freedesktop/hal/udev_event"
985 will pass the whole udev event to the HAL daemon without the need
986 for a forked helper. (See ChangeLog for udevmonitor, as an example)
990 Mostly bugfixes and see ChangeLog.
992 The test for the existence of an environment value should be
994 ENV{KEY}=="*" to ENV{KEY}=="?*"
995 because "*" will not fail anymore, if the key does not exist or
1000 Bugfixes and a few tweaks described in the ChangeLog.
1004 Mostly a Bugfix release.
1006 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1007 timing with custom rules.
1011 We changed the internal rule storage format. Our large rule files took
1012 2 MB of RAM, with the change we are down to 99kB.
1014 If the device-node has been created with default name and no symlink or
1015 options are to remenber, it is not longer stored in the udevdb. HAL will
1016 need to be updated to work correctly with that change.
1018 To overrride optimization flags, OPTFLAGS may be used now.
1026 Major changes happened with this release. The goal is to take over the
1027 complete kernel-event handling and provide a more efficient way to dispatch
1028 kernel events. Replacing most of the current shell script logic and the
1029 kernel forked helper with a netlink-daemon and a rule-based event handling.
1031 o udevd listens to netlink events now. The first valid netlink event
1032 will make udevd ignore any message from udevsend that contains a
1033 SEQNUM, to avoid duplicate events. The forked events can be disabled
1035 echo "" > /proc/sys/kernel/hotplug
1036 For full support, the broken input-subsytem needs to be fixed, not to
1037 bypass the driver core.
1039 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1040 removed from udev itself and must be emulated by calling small
1041 helper binaries provided in the extras folder:
1042 make EXTRAS=extras/run_directory/
1043 will build udev_run_devd and udev_run_hotplugd, which can be called
1044 from a rule if needed:
1045 RUN+="/sbin/udev_run_hotplugd"
1046 The recommended way to handle this is to convert all the calls from
1047 the directories to explicit udev rules and get completely rid of the
1048 multiplexing. (To catch a ttyUSB event, you now no longer need to
1049 fork and exit 300 tty script instances you are not interested in, it
1050 is just one rule that matches exactly the device.)
1052 o udev handles now _all_ events not just events for class and block
1053 devices, this way it is possible to control the complete event
1054 behavior with udev rules. Especially useful for rules like:
1055 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1057 o As used in the modalias rule, udev supports now textual
1058 substitution placeholder along with the usual format chars. This
1059 needs to be documented, for now it's only visible in udev_rules_parse.c.
1061 o The rule keys support now more operations. This is documented in the
1062 man page. It is possible to add values to list-keys like the SYMLINK
1063 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1064 Also "final"-assignments are supported by using KEY:="value", which will
1065 prevent changing the key by any later rule.
1067 o kernel 2.6.12 has the "detached_state" attribute removed from
1068 sysfs, which was used to recognize sysfs population. We switched that
1069 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1070 Running this udev version on older kernels may cause a short delay for
1073 o To provide infrastructure for persistent device naming, the id programs:
1074 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1075 to export the probed data in environment key format:
1076 pim:~ # /sbin/ata_id --export /dev/hda
1077 ID_MODEL=HTS726060M9AT00
1078 ID_SERIAL=MRH401M4G6UM9B
1079 ID_REVISION=MH4OA6BA
1081 The following rules:
1082 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1083 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1086 kay@pim:~> tree /dev/disk
1089 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1090 | `-- IBM-Memory_Key -> ../../sda
1092 | |-- swap -> ../../hda1
1093 | |-- date -> ../../sda1
1094 | `-- home -> ../../hda3
1096 |-- 2E08712B0870F2E7 -> ../../hda3
1097 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1098 |-- E845-7A89 -> ../../sda1
1099 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1101 The IMPORT= operation will import these keys in the environment and make
1102 it available for later PROGRAM= and RUN= executed programs. The keys are
1103 also stored in the udevdb and can be queried from there with one of the
1106 o A few binaries are silently added to the repository, which can be used
1107 to replay kernel events from initramfs instead of using coldplug. udevd
1108 can be instructed now to queue-up events while the stored events from
1109 initramfs are filled into the udevd-queue. This code is still under
1110 development and there is no documentation now besides the code itself.
1111 The additional binaries get compiled, but are not installed by default.
1113 o There is also a temporary fix for a performance problem where too many
1114 events happen in parallel and every event needs to parse the rules.
1115 udev can now read precompiled rules stored on disk. This is likely to be
1116 replaced by a more elegant solution in a future udev version.
1120 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1121 Fix for libsysfs not to expect this file was added.
1125 All rules are applied now, but only the first matching rule with a NAME-key
1126 will be applied. All later rules with NAME-key are completely ignored. This
1127 way system supplied symlinks or permissions gets applied to user-defined
1131 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1132 to some rules, to keep the old behavior.
1134 The rules are read on "remove"-events too. That makes is possible to match
1135 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1136 instruct udev to ignore an event (OPTIONS="ignore_device").
1137 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1139 The new RUN-key supports rule-based execution of programs after device-node
1140 handling. This is meant as a general replacement for the dev.d/-directories
1141 to give fine grained control over the execution of programs.
1143 The %s{}-sysfs format char replacement values are searched at any of the
1144 devices in the device chain now, not only at the class-device.
1146 We support log priority levels now. The value udev_log in udev.conf is used
1147 to determine what is printed to syslog. This makes it possible to
1148 run a version with compiled-in debug messages in a production environment
1149 which is sometimes needed to find a bug.
1150 It is still possible to supress the inclusion of _any_ syslog usage with
1151 USE_LOG=false to create the smallest possible binaries if needed.
1152 The configured udev_log value can be overridden with the environment variable
1157 Possible use of a system-wide klibc:
1158 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1159 will link against an external klibc and our own version will be ignored.
1163 We support an unlimited count of symlinks now.
1165 If USE_STATIC=true is passed to a glibc build, we link statically and use
1166 a built-in userdb parser to resolve user and group names.
1168 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1169 we walk up the chain of physical devices to find a match.
1171 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1172 easy to skip certain attribute matches without composing rules with weird
1173 character class negations like:
1174 KERNEL="[!s][!c][!d]*"
1175 this can now be replaced with:
1177 The current simple '=' is still supported, and should work as it does today,
1178 but existing rules should be converted if possible, to be better readable.
1180 We have new ENV{}== key now, to match against a maximum of 5 environment
1183 udevstart is its own binary again, because we don't need co carry this araound
1184 with every forked event.
~ianmdlvl / elogind.git / blob