5 Event processes now get re-used after they handled an event. This reduces
6 pressure on the CPU significantly because cloned event processes no longer
7 cause page faults in the main daemon. After the events have settled, a few
8 worker processes stay around for future events, all others get cleaned up.
10 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
11 Also inotify support is required now to run udev.
13 The format of the queue exported by the udev damon has changed. There is
14 no longer a /dev/.udev/queue/ directory. The current event queue can be
15 accessed with udevadm settle and libudedv.
17 Libudev does not have the unstable API header anymore. From now on,
18 incompatible changes will be handled by bumping the library major version.
24 The program vol_id and the library libvolume_id are removed from the
25 repository. Libvolume_id is merged with libblkid from the util-linux-ng
26 package. Persistent disk links for label and uuid depend on the
27 util-linux-ng version (2.15) of blkid now. Older versions of blkid
28 can not be used with udev.
30 Libudev allows to subscribe to udev events. To prevent unwanted messages
31 to be delivered, and waking up the subscribing process, a filter can be
32 installed, to drop messages inside a kernel socket filter. The filters
33 match on the <subsytem>:<devtype> properties of the device.
34 This is part of the ongoing effort to replace HAL, and switch current
35 users over to directly use libudev.
36 Libudev is still marked as experimental, and its interface might
37 eventually change if needed, but no major changes of the currently exported
38 interface are expected anymore, and a first stable release should happen
41 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
42 is not supported since while and udevd will log an error message at
43 startup. It should still be able to boot-up, but advanced rules and system
44 services which depend on the information not available in the old sysfs
45 format will fail to work correctly.
47 DVB device naming is supplied by the kernel now. In case older kernels
48 need to be supported, the old shell script should be added to a compat
55 The processed udev events get send back to the netlink socket. Libudev
56 provides access to these events. This is work-in-progress, to replace
57 the DeviceKit daemon functionality directly with libudev. There are
58 upcoming kernel changes to allow non-root users to subcribe to these
65 "udevadm settle" now optionally accepts a range of events to wait for,
66 instead of waiting for "all" events.
72 The installed watch for block device metadata changes is now removed
73 during event hadling, because some (broken) tools may be called from udev
74 rules and (wrongly) open the device with write access. After the finished
75 event handling the watch is restored.
81 Device nodes can be watched for changes with inotify with OPTIONS="watch".
82 If closed after being opened for writing, a "change" uevent will occur.
83 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
89 The udevadm test command has no longer a --force option, nodes and symlinks
90 are always updated with a test run now.
92 The udevd daemon can be started with --resolve-names=never to avoid all user
93 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
94 lookup user and groups every time events are handled.
100 We are currently merging the Ubuntu rules in the udev default rules,
101 and get one step closer to provide a common Linux /dev setup, regarding
102 device names, symlinks, and default device permissions. On udev startup,
103 we now expect the following groups to be resolvable to their ids with
105 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
106 LDAP setups need to make sure, that these groups are always resolvable at
107 bootup, with only the rootfs mounted, and without network access available.
109 Some systems may need to add some new, currently not used groups, or need
110 to add some users to new groups, but the cost of this change is minimal,
111 compared to the pain the current, rather random, differences between the
112 various distributions cause for upstream projects and third-party vendors.
114 In general, "normal" users who log into a machine should never be a member
115 of any such group, but the device-access should be managed by dynamic ACLs,
116 which get added and removed for the specific users on login/logout and
117 session activity/inactivity. These groups are only provided for custom setups,
118 and mainly system services, to allow proper privilege separation.
119 A video-streaming daemon uid would be a member of "audio" and "video", to get
120 access to the sound and video devices, but no "normal" user should ever belong
121 to the "audio" group, because he could listen to the built-in microphone with
122 any ssh-session established from the other side of the world.
124 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
125 which do not depend on the kernel device name. As usual, unique
126 devices - only a single one per product connected, or a real
127 USB serial number in the device - are always found with the same
128 name in the by-id/ directory.
129 Completely identical devices may overwrite their names in by-id/
130 and can only be found reliably in the by-path/ directory. Devices
131 specified by by-path/ must not change their connection, like the
132 USB port number they are plugged in, to keep their name.
134 To support some advanced features, Linux 2.6.22 is the oldest supported
135 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
136 supported. Older kernels should still work, and devices nodes should be
137 reliably created, but some rules and libudev will not work correctly because
138 the old kernels do not provide the expected information or interfaces.
144 Fix for a possible segfault while swapping network interface names in udev
151 The group "video" is part of the default rules now.
155 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
156 block devices in some cases. No common distro uses this option anymore,
157 and we do not get enough testing for this and recent udev versions. If
158 this option is not needed to run some old distro with a new kernel,
159 it should be disabled in the kernel config.
161 Bugfix for the $links substitution variable, which may crash if no links
162 are created. This should not happen in usual setups because we always
163 create /dev/{block,char}/ links.
165 The strings of the parsed rules, which are kept in memory, no longer
166 contain duplicate entries, or duplicate tails of strings. This, and the
167 new rules parsing/matching code reduces the total in-memory size of
168 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
171 The export of DEVTYPE=disk/partition got removed from the default
172 rules. This value is available from the kernel. The pnp shell script
173 modprobe hack is removed from the default rules. ACPI devices have _proper_
174 modalias support and take care of the same functionality.
175 Installations which support old kernels, but install current default
176 udev rules may want to add that to the compat rules file.
178 Libvolume_id now always probes for all known filesystems, and does not
179 stop at the first match. Some filesystems are marked as "exclusive probe",
180 and if any other filesytem type matches at the same time, libvolume_id
181 will, by default, not return any probing result. This is intended to prevent
182 mis-detection with conflicting left-over signatures found from earlier
183 file system formats. That way, we no longer depend on the probe-order
184 in case of multiple competing signatures. In some setups the kernel allows
185 to mount a volume with just the old filesystem signature still in place.
186 This may damage the new filesystem and cause data-loss, just by mounting
187 it. Because volume_id can not decide which one the correct signature is,
188 the wrong signatures need to be removed manually from the volume, or the
189 volume needs to be reformatted, to enable filesystem detection and possible
194 Fix segfault if compiled without optimization and dbg() does not get
195 compiled out and uses variables which are not available.
199 Bugfixes. (And maybe new bugs. :))
201 The rule matching engine got converted from a rule list to a token
202 array which reduced the in-memory rules representation of a full
203 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
204 Limits like 5 ENV and ATTR matches, and one single instance for most
205 other keys per rule are gone.
207 The NAME assignment is no longer special cased. If later rules assign
208 a NAME value again, the former value will be overwritten. As usual
209 for most other keys, the NAME value can be protected by doing a final
210 assignment with NAME:="<value>".
212 All udev code now uses libudev, which is also exported. The library
213 is still under development, marked as experimental, and its interface
214 may change as long as the DeviceKit integration is not finished.
216 Many thanks to Alan Jenkins for his continuous help, and finding and
217 optimizing some of the computing expensive parts.
223 Kernel devices and device nodes are connected now by reverse indizes in
224 /sys and /dev. A device number retrieved by a stat() or similar, the
225 kernel device directory can be found by looking up:
226 /sys/dev/{block,char}/<maj>:<min>
227 and the device node of the same device by looking up:
228 /dev/{block,char}/<maj>:<min>
232 Fix recently introduced bug, which caused a compilation without large
233 file support, where vol_id does not recognize raid signatures at the end
236 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
237 Seems some kernel versions prevent the creation of the ieee-* links,
238 so people used the scsi-* link which disappeared now.
240 More libudev work. Almost all udevadm functionality comes from libudev
243 udevadm trigger has a new option --type, which allows to trigger events
244 for "devices", for "subsystems", or "failed" devices. The old option
245 --retry-failed" still works, but is no longer mentioned in the man page.
251 The udevadm info --device-id-of-file= output has changed to use
252 the obvious format. Possible current users should use the --export
253 option which is not affected.
255 The old udev commands symlinks to udevadm are not installed, if
256 these symlinks are used, a warning is printed.
262 Optical drive's media is no longer probed for raid signatures,
263 reading the end of the device causes some devices to malfunction.
264 Also the offset of the last session found is used now to probe
267 The volume_id library got a major version number update to 1,
268 some deprecated functions are removed.
270 A shared library "libudev" gets installed now to provide access
271 to udev device information. DeviceKit, the successor of HAL, will
272 need this library to access the udev database and search sysfs for
274 The library is currently in an experimental state, also the API is
275 expected to change, as long as the DeviceKit integration is not
280 We use ./configure now. See INSTALL for details. Current
283 "/usr" - prefix for man pages, include files
285 "" - the root filesystem, prefix for libs and binaries
289 "lib" - directory name for libraries, not a path name
290 multilib 64bit systems may use "lib64" instead of "lib"
292 compile-in verbose debug messages
294 disable all logging and compile-out all log strings
296 link against SELInux libraries, to set the expected context
299 In the default rules, the group "disk" gets permissions 0660 instead
300 of 0640. One small step closer to unify distro rules. Some day, all
301 distros hopefully end up with the same set of rules.
303 No symlinks to udevadm are installed anymore, if they are still needed,
304 they should be provided by the package.
310 Default udev rules, which are not supposed to be edited by the user, should
311 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
312 the udev package and will be replaced with an update. Udev will pick up rule
314 /lib/udev/rules.d/ - default installed rules
315 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
316 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
317 It does not matter in which directory a rule file lives, all files are sorted
320 To help creating /dev/root, we have now:
321 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
324 In case the current --device-id-of-file is already used, please switch to
325 the --export format version, it saves the output parsing and the old
326 format will be changed to use ':' as a separator, like the format in the
331 Fix cdrom_id to properly recognize blank media.
337 Tape drive id-data is queried from /dev/bsg/* instead of the tape
338 nodes. This avoids rewinding tapes on open().
344 The symlinks udevcontrol and udevtrigger are no longer installed by
347 The scsi_id program does not depend on sysfs anymore. It can speak
348 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
349 data, which should solve some old problems with tape devices, where
350 we better do not open all tape device nodes to identify the device.
356 The cdrom_id program is replaced by an advanced version, which can
357 detect most common device types, and also properties of the inserted
358 media. This is part of moving some basic functionality from HAL into
359 udev (and the kernel).
365 The last WAIT_FOR_SYSFS rule is removed from the default rules.
367 The symlinks to udevadm for the debugging tools: udevmonitor and
368 udevtest are no longer created.
370 The symlinks to the udevadm man page for the old tool names are
373 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
374 should be prefixed with '@' to indicate that the path is not a
385 Udevstart is removed from the tree, it did not get installed for
386 a long time now, and is long replaced by trigger and settle.
392 All udev tools are merged into a single binary called udevadm.
393 The old names of the tools are built-in commands in udevadm now.
394 Symlinks to udevadm, with the names of the old tools, provide
395 the same functionality as the standalone tools. There is also
396 only a single udevadm.8 man page left for all tools.
398 Tools like mkinitramfs should be checked, if they need to include
399 udevadm in the list of files.
409 The etc/udev/rules.d/ directory now contains a default set of basic
410 udev rules. This initial version is the result of a rules file merge
411 of Fedora and openSUSE. For these both distros only a few specific
412 rules are left in their own file, named after the distro. Rules which
413 are optionally installed, because they are only valid for a specific
414 architecture, or rules for subsystems which are not always used are
415 in etc/udev/packages/.
421 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
422 actions by dynamically created rules.
424 SYMLINK=="<value>" matches agains the entries in the list of
425 currently defined symlinks. The links are not created in the
426 filesystem at that point in time, but the values can be matched.
428 RUN{ignore_error}+="<program>" will ignore any exit code from the
429 program and not record as a failed event.
435 Final merge of patches/features from the Ubuntu package.
441 Control characters in filesystem label strings are no longer silenty
442 removed, but hex-encoded, to be able to uniquely identify the device
443 by its symlink in /dev/disk/by-label/.
444 If libvolume_id is used by mount(8), LABEL= will work as expected,
445 if slashes or other characters are used in the label string.
447 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
448 can be specified now. The TEST key accepts an optional mode mask
449 TEST{0100}=="<is executable file>".
451 Scsi_id now supports a mode without expecting scsi-specific sysfs
452 entries to allow the extraction of cciss-device persistent properties.
458 In the future, we may see uuid's which are just simple character
459 strings (see the DDF Raid Specification). For that reason vol_id now
460 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
461 the creation of symlinks, the *_SAFE values ensure, that no control
462 or whitespace characters are used in the filename.
464 Possible users of libvolume_id, please use the volume_id_get_* functions.
465 The public struct will go away in a future release of the library.
471 Removal of useless extras/eventrecorder.sh.
481 The directory multiplexer for dev.d/ and hotplug.d are finally removed
482 from the udev package.
488 Symlinks can have priorities now, the priority is assigned to the device
489 and specified with OPTIONS="link_priority=100". Devices with higher
490 priorities overwrite the symlinks of devices with lower priorities.
491 If the device that currently owns the link, goes away, the symlink
492 will be removed, and recreated, pointing to the next device with the
493 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
494 more reliable, if multiple devices contain the same metadata and overwrite
497 The dasd_id program is removed from the udev tree, and dasdinfo, with the
498 needed rules, are part of the s390-tools now.
500 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
501 we may get the scsi sysfs mess fixed some day, and this will only catch
502 the devices we are looking for.
504 USB serial numbers for storage devices have the target:lun now appended,
505 to make it possibble to distinguish broken multi-lun devices with all
506 the same SCSI identifiers.
508 Note: The extra "run_directory" which searches and executes stuff in
509 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
510 with the next release. Make sure, that you don't use it anymore, or
511 provides your own implementation of that inefficient stuff.
512 We are tired of reports about a "slow udev", because these directories
513 contain stuff, that runs with _every_ event, instead of using rules,
514 that run programs only for the matching events.
524 DRIVER== will match only for devices that actually have a real
525 driver. DRIVERS== must be used, if parent devices should be
526 included in the match.
528 Libvolume_id's "linux_raid" detection needed another fix.
536 Add additional check to volume_id detection of via_raid, cause
537 some company decided to put a matching pattern all over the empty
538 storage area of their music players.
542 Fix path_id for SAS devices.
546 The udev daemon can be started with --debug-trace now, which will
547 execute all events serialized to get a chance to catch a possible
548 action that crashes the box.
550 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
551 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
552 are excluded from the warning. Referencing parent attributes directly
553 may break when something in the kernel driver model changes. Udev will
554 just find the attribute by walking up the parent chain.
556 Udevtrigger now sorts the list of devices depending on the device
557 dependency, so a "usb" device is triggered after the parent "pci"
562 Revert persistent-storage ata-serial '_' '-' replacement.
568 Udevtrigger can now filter the list of devices to be triggered. Matches
569 for subsystems or sysfs attributes can be specified.
571 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
572 zero-sized files to avoid pointing to /sys and confuse broken tools which
573 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
576 The rules and scripts to create udev rules for persistent network
577 devices and optical drives are in the extras/rules_generator directory
578 now. If you use something similar, please consider replacing your own
579 version with this, to share the support effort. The rule_generator
580 installs its own rules into /etc/udev/rules.d.
582 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
583 the rule_generator depends on cdrom_id to be called in an earlier rule.
589 Renaming of some key names (the old names still work):
590 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
591 (The behavior of the key DRIVER will change soon in one of the next
592 releases, to match only the event device, please switch to DRIVERS
593 instead. If DRIVER is used, it will behave like DRIVERS, but an error
595 With the new key names, we have a more consistent and simpler scheme.
596 We can match the properties of the event device only, with: KERNEL,
597 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
598 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
599 longer mentioned in the man page and should be switched in the rule
602 ATTR{file}="value" can be used now, to write to a sysfs file of the
603 event device. Instead of:
604 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
606 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
608 All the PHYSDEV* keys are deprecated and will be removed from a
610 PHYDEVPATH - is the path of a parent device and should not be
612 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
613 matched with SUBSYSTEMS==
614 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
615 Newer kernels will have DRIVER in the environment,
616 for older kernels udev puts in. Class device will
617 no longer carry this property of a parent and
618 DRIVERS== can be used to match such a parent value.
619 Note that ENV{DRIVER} is only available for a few bus devices, where
620 the driver is already bound at device event time. On coldplug, the
621 events for a lot devices are already bound to a driver, and they will have
622 that value set. But on hotplug, at the time the kernel creates the device,
623 it can't know what driver may claim the device after that, therefore
624 in most cases it will be empty.
626 Failed events should now be re-triggered with:
627 udevtrigger --retry-failed.
628 Please switch to this command, so we keep the details of the /dev/.udev/failed/
629 files private to the udev tools. We may need to switch the current symlink
630 target, cause some obviously broken tools try to scan all files in /dev
631 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
632 million times. This takes ages on slow boxes.
634 The udevinfo attribute walk (-a) now works with giving a device node
635 name (-n) instead of a devpath (-p). The query now always works, also when
636 no database file was created by udev.
638 The built-in /etc/passwd /etc/group parser is removed, we always depend on
639 getpwnam() and getgrnam() now. One of the next releases will depend on
640 fnmatch() and may use getopt_long().
644 Bugfixes and small improvements.
648 Fix path_id for recent kernels.
654 Added support for swapping network interface names, by temporarily
655 renaming the device and wait for the target name to become free.
659 The built-in MODALIAS key and substitution is removed.
663 The binary firmware helper is replaced by the usual simple
664 shell script. Udevsend is removed from the tree.
672 Some more keys require the correct use of '==' and '=' depending
673 on the kind of operation beeing an assignment or a match. Rules
674 with invalid operations are skipped and logged to syslog. Please
675 test with udevtest if the parsing of your rules throws errors and
676 fix possibly broken rules.
680 Provide "udevsettle" to wait for all current udev events to finish.
681 It also watches the current kernel netlink queue by comparing the
682 even sequence number to make sure that there are no current pending
683 events that have not already arrived in the daemon.
687 Fix rule to skip persistent rules for removable IDE devices, which
688 also skipped optical IDE drives.
690 All *_id program are installed in /lib/udev/ by default now.
692 No binary is stripped anymore as this should be done in the
693 packaging process and not at build time.
695 libvolume_id is provided as a shared library now and vol_id is
696 linked against it. Also one of the next HAL versions will require
697 this library, and the HAL build process will also require the
698 header file to be installed. The copy of the same code in HAL will
699 be removed to have only a single copy left on the system.
703 Add persistent links for SCSI tapes. The rules file is renamed
704 to 60-persistent-storage.rules.
706 Create persistent path for usb devices. Can be used for all sorts
707 of devices that can't be distinguished by other properties like
708 multiple identical keyboards and mice connected to the same box.
710 Provide "udevtrigger" program to request events on coldplug. The
711 shell script is much too slow with thousends of devices.
715 Fix persistent disk rules to exclude removable IDE drives.
717 Warn if %e, $modalias or MODALIAS is used.
721 Fix queue export, which wasn't correct for subsequent add/remove
722 events for the same device.
726 Fix cramfs detection on big endian.
728 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
733 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
734 attributes were only checked at the parent device that matched the
735 by BUS requested subsystem. Fix it to also look at the device we
736 received the event for.
738 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
743 Fix a bug where NAME="" would prevent RUN from beeing executed.
745 RUN="/bin/program" does not longer automatically add the subsystem
746 as the first parameter. This is from the days of /sbin/hotplug
747 which is dead now and it's just confusing to need to add a space at
748 the end of the program name to prevent this.
749 If you use rules that need the subsystem as the first parameter,
750 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
751 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
755 The udev man page has moved to udev(7) as it does not describe a command
756 anymore. The programs udev, udevstart and udevsend are no longer installed
757 by default and must be copied manually, if they should be installed or
758 included in a package.
760 Fix a bug where "ignore_device" could run earlier collected RUN keys before
761 the ignore rule was applied.
763 More preparation for future sysfs changes. usb_id and scsi_id no longer
764 depend on a magic order of devices in the /devices chain. Specific devices
765 should be requested by their subsytem.
767 This will always find the scsi parent device without depending on a specific
769 dev = sysfs_device_get(devpath);
770 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
772 The "device" link in the current sysfs layout will be automatically
773 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
774 parent in the devpath. If a device is requested by it's symlink, like all
775 class devices in the new sysfs layout will look like, it gets automatically
776 resolved and substituted with the real devpath and not the symlink path.
779 A similar logic must be applied to _all_ sysfs users, including
780 scripts, that search along parent devices in sysfs. The explicit use of
781 the "device" link must be avoided. With the future sysfs layout all
782 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
783 back to the "class" or the "bus". The layout of the parent devices in
784 /devices is not necessarily expected to be stable across kernel releases and
785 searching for parents by their subsystem should make sysfs users tolerant
786 for changed parent chains.
790 Prepare udev to work with the experimental kernel patch, that moves
791 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
793 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
794 moving the class devices to /sys/devices.
796 Thanks again to Marco for help finding a hopefully nice compromise
797 to make %b simpler and working again.
801 Complete removal of libsysfs, replaced by simple helper functions
802 which are much simpler and a bit faster. The udev daemon operatesentirely
803 on event parameters and does not use sysfs for simple rules anymore.
804 Please report any new bugs/problems, that may be caused by this big
805 change. They will be fixed immediately.
807 The enumeration format character '%e' is deprecated and will be
808 removed sometimes from a future udev version. It never worked correctly
809 outside of udevstart, so we can't use it with the new parallel
810 coldplug. A simple enumeration is as useless as the devfs naming
811 scheme, just get rid of both if you still use it.
813 MODALIAS and $modalias is not needed and will be removed from one of
814 the next udev versions, replace it in all rules with ENV{MODALIAS} or
815 the sysfs "modalias" value.
817 Thanks a lot to Marco for all his help on finding and fixing bugs.
821 Let scsi_id request libata drive serial numbers from page 0x80.
823 Renamed etc/udev/persistent.rules to persistent-disk.rules and
824 added /dev/disk/by-name/* for device mapper device names.
826 Removed %e from the man page. It never worked reliably outside
827 of udevstart and udevstart is no longer recommended to use.
831 Symlinks are now exported to the event environment. Hopefully it's no
832 longer needed to run udevinfo from an event process, like it was
833 mentioned on the hotplug list:
834 UDEV [1134776873.702967] add@/block/sdb
837 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
841 Fix a problem if udevsend is used as the hotplug handler and tries to use
842 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
843 and this kind of problems will hopefully go away soon.
847 All built-in logic to work around bad sysfs timing is removed with this
848 version. The need to wait for sysfs files is almost fixed with a kernel
849 version that doesn't work with this udev version anyway. Until we fix
850 the timing of the "bus" link creation, the former integrated logic should
851 be emulated by a rule placed before all other rules:
852 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
854 The option "udev_db" does no longer exist. All udev state will be in
855 /$udev_root/.udev/ now, there is no longer an option to set this
857 If the init script or something else used this value, just depend on
858 this hardcoded path. But remember _all_content_ of this directory is
859 still private to udev and can change at any time.
861 Default location for rule sripts and helper programs is now: /lib/udev/.
862 Everything that is not useful on the commandline should go into this
863 directory. Some of the helpers in the extras folder are installed there
864 now. The rules need to be changed, to find the helpers there.
866 Also /lib/udev/devices is recommended as a directory where packages or
867 the user can place real device nodes, which get copied over to /dev at
868 every boot. This should replace the various solutions with custom config
871 Udevsend does no longer start the udev daemon. This must be done with
872 the init script that prepares /dev on tmpfs and creates the initial nodes,
873 before starting the daemon.
877 Silent a too verbose error logging for the old hotplug.d/ dev.d/
880 The copy of klibc is removed. A systemwide installed version of klibc
881 should be used to build a klibc udev now.
885 NAME="" will not create any nodes, but execute RUN keys. To completely
886 ignore an event the OPTION "ignore_device" should be used.
888 After removal of the reorder queue, events with a TIMEOUT can be executed
889 without any queuing now.
893 Fixed bug in udevd, if inotify is not available. We depend on netlink
894 uevents now, kernels without that event source will not work with that
895 version of udev anymore.
899 The rule parsing happens now in the daemon once at startup, all udev
900 event processes inherit the already parsed rules from the daemon.
901 It is shipped with SUSE10.0 and reduces heavily the system load at
902 startup. The option to save precompiled rules and let the udev process
903 pick the them up is removed, as it's no longer needed.
905 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
906 device. Libsysfs is changed to "translate" the requested link into the
907 real device path, as it would happen with the hotplug event. Otherwise
908 device removal and the udev database will not work.
910 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
913 A few improvements for vol_id, the filesytem probing code.
917 Fix a stupid typo in extras/run_directory for "make install".
919 scsi_id creates the temporary devnode now in /dev for usage with a
920 non-writable /tmp directory.
922 The uevent kernel socket buffer can carry app. 50.000 events now,
923 let's see who can break this again. :)
925 The upcoming kernel will have a new input driver core integration.
926 Some class devices are now symlinks to the real device. libsysfs
927 needs a fix for this to work correctly. Udevstart of older udev
928 versions will _not_ create these devices!
932 Fix a 'install' target in the Makefile, that prevents EXTRAS from
937 A bunch of mostly trivial bugfixes. From now on no node name or
938 symlink name can contain any character than plain whitelisted ascii
939 characters or validated utf8 byte-streams. This is needed for the
940 /dev/disk/by-label/* links, because we import untrusted data and
941 export it to the filesystem.
945 More bugfixes. If udevd was started from the kernel, we don't
946 have stdin/stdout/stderr, which broke the forked tools in some
951 Bugfix. udevstart event ordering was broken for a long time.
952 The new run_program() uncovered it, because /dev/null was not
953 available while we try to run external programs.
954 Now udevstart should create it before we run anything.
958 Minor bugfixes and some distro rules updates. If you don't have the
959 persistent disk rules in /dev/disk/by-*/* on your distro, just
960 grab it from here. :)
964 We can use socket communication now to pass events from udev to
966 RUN+="socket:/org/freedesktop/hal/udev_event"
967 will pass the whole udev event to the HAL daemon without the need
968 for a forked helper. (See ChangeLog for udevmonitor, as an example)
972 Mostly bugfixes and see ChangeLog.
974 The test for the existence of an environment value should be
976 ENV{KEY}=="*" to ENV{KEY}=="?*"
977 because "*" will not fail anymore, if the key does not exist or
982 Bugfixes and a few tweaks described in the ChangeLog.
986 Mostly a Bugfix release.
988 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
989 timing with custom rules.
993 We changed the internal rule storage format. Our large rule files took
994 2 MB of RAM, with the change we are down to 99kB.
996 If the device-node has been created with default name and no symlink or
997 options are to remenber, it is not longer stored in the udevdb. HAL will
998 need to be updated to work correctly with that change.
1000 To overrride optimization flags, OPTFLAGS may be used now.
1008 Major changes happened with this release. The goal is to take over the
1009 complete kernel-event handling and provide a more efficient way to dispatch
1010 kernel events. Replacing most of the current shell script logic and the
1011 kernel forked helper with a netlink-daemon and a rule-based event handling.
1013 o udevd listens to netlink events now. The first valid netlink event
1014 will make udevd ignore any message from udevsend that contains a
1015 SEQNUM, to avoid duplicate events. The forked events can be disabled
1017 echo "" > /proc/sys/kernel/hotplug
1018 For full support, the broken input-subsytem needs to be fixed, not to
1019 bypass the driver core.
1021 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1022 removed from udev itself and must be emulated by calling small
1023 helper binaries provided in the extras folder:
1024 make EXTRAS=extras/run_directory/
1025 will build udev_run_devd and udev_run_hotplugd, which can be called
1026 from a rule if needed:
1027 RUN+="/sbin/udev_run_hotplugd"
1028 The recommended way to handle this is to convert all the calls from
1029 the directories to explicit udev rules and get completely rid of the
1030 multiplexing. (To catch a ttyUSB event, you now no longer need to
1031 fork and exit 300 tty script instances you are not interested in, it
1032 is just one rule that matches exactly the device.)
1034 o udev handles now _all_ events not just events for class and block
1035 devices, this way it is possible to control the complete event
1036 behavior with udev rules. Especially useful for rules like:
1037 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1039 o As used in the modalias rule, udev supports now textual
1040 substitution placeholder along with the usual format chars. This
1041 needs to be documented, for now it's only visible in udev_rules_parse.c.
1043 o The rule keys support now more operations. This is documented in the
1044 man page. It is possible to add values to list-keys like the SYMLINK
1045 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1046 Also "final"-assignments are supported by using KEY:="value", which will
1047 prevent changing the key by any later rule.
1049 o kernel 2.6.12 has the "detached_state" attribute removed from
1050 sysfs, which was used to recognize sysfs population. We switched that
1051 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1052 Running this udev version on older kernels may cause a short delay for
1055 o To provide infrastructure for persistent device naming, the id programs:
1056 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1057 to export the probed data in environment key format:
1058 pim:~ # /sbin/ata_id --export /dev/hda
1059 ID_MODEL=HTS726060M9AT00
1060 ID_SERIAL=MRH401M4G6UM9B
1061 ID_REVISION=MH4OA6BA
1063 The following rules:
1064 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1065 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1068 kay@pim:~> tree /dev/disk
1071 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1072 | `-- IBM-Memory_Key -> ../../sda
1074 | |-- swap -> ../../hda1
1075 | |-- date -> ../../sda1
1076 | `-- home -> ../../hda3
1078 |-- 2E08712B0870F2E7 -> ../../hda3
1079 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1080 |-- E845-7A89 -> ../../sda1
1081 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1083 The IMPORT= operation will import these keys in the environment and make
1084 it available for later PROGRAM= and RUN= executed programs. The keys are
1085 also stored in the udevdb and can be queried from there with one of the
1088 o A few binaries are silently added to the repository, which can be used
1089 to replay kernel events from initramfs instead of using coldplug. udevd
1090 can be instructed now to queue-up events while the stored events from
1091 initramfs are filled into the udevd-queue. This code is still under
1092 development and there is no documentation now besides the code itself.
1093 The additional binaries get compiled, but are not installed by default.
1095 o There is also a temporary fix for a performance problem where too many
1096 events happen in parallel and every event needs to parse the rules.
1097 udev can now read precompiled rules stored on disk. This is likely to be
1098 replaced by a more elegant solution in a future udev version.
1102 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1103 Fix for libsysfs not to expect this file was added.
1107 All rules are applied now, but only the first matching rule with a NAME-key
1108 will be applied. All later rules with NAME-key are completely ignored. This
1109 way system supplied symlinks or permissions gets applied to user-defined
1113 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1114 to some rules, to keep the old behavior.
1116 The rules are read on "remove"-events too. That makes is possible to match
1117 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1118 instruct udev to ignore an event (OPTIONS="ignore_device").
1119 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1121 The new RUN-key supports rule-based execution of programs after device-node
1122 handling. This is meant as a general replacement for the dev.d/-directories
1123 to give fine grained control over the execution of programs.
1125 The %s{}-sysfs format char replacement values are searched at any of the
1126 devices in the device chain now, not only at the class-device.
1128 We support log priority levels now. The value udev_log in udev.conf is used
1129 to determine what is printed to syslog. This makes it possible to
1130 run a version with compiled-in debug messages in a production environment
1131 which is sometimes needed to find a bug.
1132 It is still possible to supress the inclusion of _any_ syslog usage with
1133 USE_LOG=false to create the smallest possible binaries if needed.
1134 The configured udev_log value can be overridden with the environment variable
1139 Possible use of a system-wide klibc:
1140 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1141 will link against an external klibc and our own version will be ignored.
1145 We support an unlimited count of symlinks now.
1147 If USE_STATIC=true is passed to a glibc build, we link statically and use
1148 a built-in userdb parser to resolve user and group names.
1150 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1151 we walk up the chain of physical devices to find a match.
1153 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1154 easy to skip certain attribute matches without composing rules with weird
1155 character class negations like:
1156 KERNEL="[!s][!c][!d]*"
1157 this can now be replaced with:
1159 The current simple '=' is still supported, and should work as it does today,
1160 but existing rules should be converted if possible, to be better readable.
1162 We have new ENV{}== key now, to match against a maximum of 5 environment
1165 udevstart is its own binary again, because we don't need co carry this araound
1166 with every forked event.
~ianmdlvl / elogind.git / blob