5 To support DEVPATH strings larger than the maximum file name length, the
6 private udev database format has changed. If some software still reads the
7 private files in /dev/.udev/, which it shouldn't, now it's time to fix it.
8 Please do not port anything to the new format again, everything in /dev/.udev
9 is and always was private to udev, and may and will change any time without
12 NAME="%k" causes a warning now. It's is and always was completely superfluous.
13 It will break kernel supplied DEVNAMEs and therefore it needs to be removed
16 Symlinks to udevadm with the old command names are no longer resolved to
23 The udevadm trigger "--retry-failed" option, which is replaced since quite
24 a while by "--type=failed" is removed.
26 The failed tracking was not working at all for a few releases. The RUN
27 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
28 default is not to track any failing RUN executions.
30 New keymaps, new modem, hid2hci updated.
34 Fix possible crash in udevd when worker processes are busy, rules are
35 changed at the same time, and workers get killed to reload the rules.
41 Properties set with ENV{.FOO}="bar" are marked private by starting the
42 name with a '.'. They will not be stored in the database, and not be
43 exported with the event.
45 Firmware files are looked up in:
46 /lib/firmware/updates/$(uname -r)
48 /lib/firmware/$(uname -r)
52 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
53 ata_id, instead of scsi_id, is the default tool now for ATA devices.
59 The configure options have changed because another library needs to be
60 installed in a different location. Instead of exec_prefix and udev_prefix,
61 libdir, rootlibdir and libexecdir are used. The Details are explained in
64 Event processes now get re-used after they handled an event. This reduces
65 the number of forks and the pressure on the CPU significantly, because
66 cloned event processes no longer cause page faults in the main daemon.
67 After the events have settled, a few worker processes stay around for
68 future events, all others get cleaned up.
70 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
71 Also inotify support is mandatory now to run udev.
73 The format of the queue exported by the udev damon has changed. There is
74 no longer a /dev/.udev/queue/ directory. The current event queue can be
75 accessed with udevadm settle and libudedv.
77 Libudev does not have the unstable API header anymore. From now on,
78 incompatible changes will be handled by bumping the library major version.
80 To build udev from the git tree gtk-doc is needed now. The tarballs will
81 build without it and contain the pre-built documentation. An online copy
83 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
85 The tools from the udev-extras repository have been merged into the main
86 udev repository. Some of the extras have larger external dependencies, and
87 they can be disabled with the configure switch --disable-extras.
93 The program vol_id and the library libvolume_id are removed from the
94 repository. Libvolume_id is merged with libblkid from the util-linux-ng
95 package. Persistent disk links for label and uuid depend on the
96 util-linux-ng version (2.15) of blkid now. Older versions of blkid
97 can not be used with udev.
99 Libudev allows to subscribe to udev events. To prevent unwanted messages
100 to be delivered, and waking up the subscribing process, a filter can be
101 installed, to drop messages inside a kernel socket filter. The filters
102 match on the <subsytem>:<devtype> properties of the device.
103 This is part of the ongoing effort to replace HAL, and switch current
104 users over to directly use libudev.
105 Libudev is still marked as experimental, and its interface might
106 eventually change if needed, but no major changes of the currently exported
107 interface are expected anymore, and a first stable release should happen
110 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
111 is not supported since while and udevd will log an error message at
112 startup. It should still be able to boot-up, but advanced rules and system
113 services which depend on the information not available in the old sysfs
114 format will fail to work correctly.
116 DVB device naming is supplied by the kernel now. In case older kernels
117 need to be supported, the old shell script should be added to a compat
124 The processed udev events get send back to the netlink socket. Libudev
125 provides access to these events. This is work-in-progress, to replace
126 the DeviceKit daemon functionality directly with libudev. There are
127 upcoming kernel changes to allow non-root users to subcribe to these
134 "udevadm settle" now optionally accepts a range of events to wait for,
135 instead of waiting for "all" events.
141 The installed watch for block device metadata changes is now removed
142 during event hadling, because some (broken) tools may be called from udev
143 rules and (wrongly) open the device with write access. After the finished
144 event handling the watch is restored.
150 Device nodes can be watched for changes with inotify with OPTIONS="watch".
151 If closed after being opened for writing, a "change" uevent will occur.
152 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
158 The udevadm test command has no longer a --force option, nodes and symlinks
159 are always updated with a test run now.
161 The udevd daemon can be started with --resolve-names=never to avoid all user
162 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
163 lookup user and groups every time events are handled.
169 We are currently merging the Ubuntu rules in the udev default rules,
170 and get one step closer to provide a common Linux /dev setup, regarding
171 device names, symlinks, and default device permissions. On udev startup,
172 we now expect the following groups to be resolvable to their ids with
174 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
175 LDAP setups need to make sure, that these groups are always resolvable at
176 bootup, with only the rootfs mounted, and without network access available.
178 Some systems may need to add some new, currently not used groups, or need
179 to add some users to new groups, but the cost of this change is minimal,
180 compared to the pain the current, rather random, differences between the
181 various distributions cause for upstream projects and third-party vendors.
183 In general, "normal" users who log into a machine should never be a member
184 of any such group, but the device-access should be managed by dynamic ACLs,
185 which get added and removed for the specific users on login/logout and
186 session activity/inactivity. These groups are only provided for custom setups,
187 and mainly system services, to allow proper privilege separation.
188 A video-streaming daemon uid would be a member of "audio" and "video", to get
189 access to the sound and video devices, but no "normal" user should ever belong
190 to the "audio" group, because he could listen to the built-in microphone with
191 any ssh-session established from the other side of the world.
193 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
194 which do not depend on the kernel device name. As usual, unique
195 devices - only a single one per product connected, or a real
196 USB serial number in the device - are always found with the same
197 name in the by-id/ directory.
198 Completely identical devices may overwrite their names in by-id/
199 and can only be found reliably in the by-path/ directory. Devices
200 specified by by-path/ must not change their connection, like the
201 USB port number they are plugged in, to keep their name.
203 To support some advanced features, Linux 2.6.22 is the oldest supported
204 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
205 supported. Older kernels should still work, and devices nodes should be
206 reliably created, but some rules and libudev will not work correctly because
207 the old kernels do not provide the expected information or interfaces.
213 Fix for a possible segfault while swapping network interface names in udev
220 The group "video" is part of the default rules now.
224 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
225 block devices in some cases. No common distro uses this option anymore,
226 and we do not get enough testing for this and recent udev versions. If
227 this option is not needed to run some old distro with a new kernel,
228 it should be disabled in the kernel config.
230 Bugfix for the $links substitution variable, which may crash if no links
231 are created. This should not happen in usual setups because we always
232 create /dev/{block,char}/ links.
234 The strings of the parsed rules, which are kept in memory, no longer
235 contain duplicate entries, or duplicate tails of strings. This, and the
236 new rules parsing/matching code reduces the total in-memory size of
237 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
240 The export of DEVTYPE=disk/partition got removed from the default
241 rules. This value is available from the kernel. The pnp shell script
242 modprobe hack is removed from the default rules. ACPI devices have _proper_
243 modalias support and take care of the same functionality.
244 Installations which support old kernels, but install current default
245 udev rules may want to add that to the compat rules file.
247 Libvolume_id now always probes for all known filesystems, and does not
248 stop at the first match. Some filesystems are marked as "exclusive probe",
249 and if any other filesytem type matches at the same time, libvolume_id
250 will, by default, not return any probing result. This is intended to prevent
251 mis-detection with conflicting left-over signatures found from earlier
252 file system formats. That way, we no longer depend on the probe-order
253 in case of multiple competing signatures. In some setups the kernel allows
254 to mount a volume with just the old filesystem signature still in place.
255 This may damage the new filesystem and cause data-loss, just by mounting
256 it. Because volume_id can not decide which one the correct signature is,
257 the wrong signatures need to be removed manually from the volume, or the
258 volume needs to be reformatted, to enable filesystem detection and possible
263 Fix segfault if compiled without optimization and dbg() does not get
264 compiled out and uses variables which are not available.
268 Bugfixes. (And maybe new bugs. :))
270 The rule matching engine got converted from a rule list to a token
271 array which reduced the in-memory rules representation of a full
272 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
273 Limits like 5 ENV and ATTR matches, and one single instance for most
274 other keys per rule are gone.
276 The NAME assignment is no longer special cased. If later rules assign
277 a NAME value again, the former value will be overwritten. As usual
278 for most other keys, the NAME value can be protected by doing a final
279 assignment with NAME:="<value>".
281 All udev code now uses libudev, which is also exported. The library
282 is still under development, marked as experimental, and its interface
283 may change as long as the DeviceKit integration is not finished.
285 Many thanks to Alan Jenkins for his continuous help, and finding and
286 optimizing some of the computing expensive parts.
292 Kernel devices and device nodes are connected now by reverse indizes in
293 /sys and /dev. A device number retrieved by a stat() or similar, the
294 kernel device directory can be found by looking up:
295 /sys/dev/{block,char}/<maj>:<min>
296 and the device node of the same device by looking up:
297 /dev/{block,char}/<maj>:<min>
301 Fix recently introduced bug, which caused a compilation without large
302 file support, where vol_id does not recognize raid signatures at the end
305 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
306 Seems some kernel versions prevent the creation of the ieee-* links,
307 so people used the scsi-* link which disappeared now.
309 More libudev work. Almost all udevadm functionality comes from libudev
312 udevadm trigger has a new option --type, which allows to trigger events
313 for "devices", for "subsystems", or "failed" devices. The old option
314 --retry-failed" still works, but is no longer mentioned in the man page.
320 The udevadm info --device-id-of-file= output has changed to use
321 the obvious format. Possible current users should use the --export
322 option which is not affected.
324 The old udev commands symlinks to udevadm are not installed, if
325 these symlinks are used, a warning is printed.
331 Optical drive's media is no longer probed for raid signatures,
332 reading the end of the device causes some devices to malfunction.
333 Also the offset of the last session found is used now to probe
336 The volume_id library got a major version number update to 1,
337 some deprecated functions are removed.
339 A shared library "libudev" gets installed now to provide access
340 to udev device information. DeviceKit, the successor of HAL, will
341 need this library to access the udev database and search sysfs for
343 The library is currently in an experimental state, also the API is
344 expected to change, as long as the DeviceKit integration is not
349 We use ./configure now. See INSTALL for details. Current
352 "/usr" - prefix for man pages, include files
354 "" - the root filesystem, prefix for libs and binaries
358 "lib" - directory name for libraries, not a path name
359 multilib 64bit systems may use "lib64" instead of "lib"
361 compile-in verbose debug messages
363 disable all logging and compile-out all log strings
365 link against SELInux libraries, to set the expected context
368 In the default rules, the group "disk" gets permissions 0660 instead
369 of 0640. One small step closer to unify distro rules. Some day, all
370 distros hopefully end up with the same set of rules.
372 No symlinks to udevadm are installed anymore, if they are still needed,
373 they should be provided by the package.
379 Default udev rules, which are not supposed to be edited by the user, should
380 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
381 the udev package and will be replaced with an update. Udev will pick up rule
383 /lib/udev/rules.d/ - default installed rules
384 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
385 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
386 It does not matter in which directory a rule file lives, all files are sorted
389 To help creating /dev/root, we have now:
390 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
393 In case the current --device-id-of-file is already used, please switch to
394 the --export format version, it saves the output parsing and the old
395 format will be changed to use ':' as a separator, like the format in the
400 Fix cdrom_id to properly recognize blank media.
406 Tape drive id-data is queried from /dev/bsg/* instead of the tape
407 nodes. This avoids rewinding tapes on open().
413 The symlinks udevcontrol and udevtrigger are no longer installed by
416 The scsi_id program does not depend on sysfs anymore. It can speak
417 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
418 data, which should solve some old problems with tape devices, where
419 we better do not open all tape device nodes to identify the device.
425 The cdrom_id program is replaced by an advanced version, which can
426 detect most common device types, and also properties of the inserted
427 media. This is part of moving some basic functionality from HAL into
428 udev (and the kernel).
434 The last WAIT_FOR_SYSFS rule is removed from the default rules.
436 The symlinks to udevadm for the debugging tools: udevmonitor and
437 udevtest are no longer created.
439 The symlinks to the udevadm man page for the old tool names are
442 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
443 should be prefixed with '@' to indicate that the path is not a
454 Udevstart is removed from the tree, it did not get installed for
455 a long time now, and is long replaced by trigger and settle.
461 All udev tools are merged into a single binary called udevadm.
462 The old names of the tools are built-in commands in udevadm now.
463 Symlinks to udevadm, with the names of the old tools, provide
464 the same functionality as the standalone tools. There is also
465 only a single udevadm.8 man page left for all tools.
467 Tools like mkinitramfs should be checked, if they need to include
468 udevadm in the list of files.
478 The etc/udev/rules.d/ directory now contains a default set of basic
479 udev rules. This initial version is the result of a rules file merge
480 of Fedora and openSUSE. For these both distros only a few specific
481 rules are left in their own file, named after the distro. Rules which
482 are optionally installed, because they are only valid for a specific
483 architecture, or rules for subsystems which are not always used are
484 in etc/udev/packages/.
490 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
491 actions by dynamically created rules.
493 SYMLINK=="<value>" matches agains the entries in the list of
494 currently defined symlinks. The links are not created in the
495 filesystem at that point in time, but the values can be matched.
497 RUN{ignore_error}+="<program>" will ignore any exit code from the
498 program and not record as a failed event.
504 Final merge of patches/features from the Ubuntu package.
510 Control characters in filesystem label strings are no longer silenty
511 removed, but hex-encoded, to be able to uniquely identify the device
512 by its symlink in /dev/disk/by-label/.
513 If libvolume_id is used by mount(8), LABEL= will work as expected,
514 if slashes or other characters are used in the label string.
516 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
517 can be specified now. The TEST key accepts an optional mode mask
518 TEST{0100}=="<is executable file>".
520 Scsi_id now supports a mode without expecting scsi-specific sysfs
521 entries to allow the extraction of cciss-device persistent properties.
527 In the future, we may see uuid's which are just simple character
528 strings (see the DDF Raid Specification). For that reason vol_id now
529 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
530 the creation of symlinks, the *_SAFE values ensure, that no control
531 or whitespace characters are used in the filename.
533 Possible users of libvolume_id, please use the volume_id_get_* functions.
534 The public struct will go away in a future release of the library.
540 Removal of useless extras/eventrecorder.sh.
550 The directory multiplexer for dev.d/ and hotplug.d are finally removed
551 from the udev package.
557 Symlinks can have priorities now, the priority is assigned to the device
558 and specified with OPTIONS="link_priority=100". Devices with higher
559 priorities overwrite the symlinks of devices with lower priorities.
560 If the device that currently owns the link, goes away, the symlink
561 will be removed, and recreated, pointing to the next device with the
562 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
563 more reliable, if multiple devices contain the same metadata and overwrite
566 The dasd_id program is removed from the udev tree, and dasdinfo, with the
567 needed rules, are part of the s390-tools now.
569 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
570 we may get the scsi sysfs mess fixed some day, and this will only catch
571 the devices we are looking for.
573 USB serial numbers for storage devices have the target:lun now appended,
574 to make it possibble to distinguish broken multi-lun devices with all
575 the same SCSI identifiers.
577 Note: The extra "run_directory" which searches and executes stuff in
578 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
579 with the next release. Make sure, that you don't use it anymore, or
580 provides your own implementation of that inefficient stuff.
581 We are tired of reports about a "slow udev", because these directories
582 contain stuff, that runs with _every_ event, instead of using rules,
583 that run programs only for the matching events.
593 DRIVER== will match only for devices that actually have a real
594 driver. DRIVERS== must be used, if parent devices should be
595 included in the match.
597 Libvolume_id's "linux_raid" detection needed another fix.
605 Add additional check to volume_id detection of via_raid, cause
606 some company decided to put a matching pattern all over the empty
607 storage area of their music players.
611 Fix path_id for SAS devices.
615 The udev daemon can be started with --debug-trace now, which will
616 execute all events serialized to get a chance to catch a possible
617 action that crashes the box.
619 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
620 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
621 are excluded from the warning. Referencing parent attributes directly
622 may break when something in the kernel driver model changes. Udev will
623 just find the attribute by walking up the parent chain.
625 Udevtrigger now sorts the list of devices depending on the device
626 dependency, so a "usb" device is triggered after the parent "pci"
631 Revert persistent-storage ata-serial '_' '-' replacement.
637 Udevtrigger can now filter the list of devices to be triggered. Matches
638 for subsystems or sysfs attributes can be specified.
640 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
641 zero-sized files to avoid pointing to /sys and confuse broken tools which
642 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
645 The rules and scripts to create udev rules for persistent network
646 devices and optical drives are in the extras/rules_generator directory
647 now. If you use something similar, please consider replacing your own
648 version with this, to share the support effort. The rule_generator
649 installs its own rules into /etc/udev/rules.d.
651 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
652 the rule_generator depends on cdrom_id to be called in an earlier rule.
658 Renaming of some key names (the old names still work):
659 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
660 (The behavior of the key DRIVER will change soon in one of the next
661 releases, to match only the event device, please switch to DRIVERS
662 instead. If DRIVER is used, it will behave like DRIVERS, but an error
664 With the new key names, we have a more consistent and simpler scheme.
665 We can match the properties of the event device only, with: KERNEL,
666 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
667 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
668 longer mentioned in the man page and should be switched in the rule
671 ATTR{file}="value" can be used now, to write to a sysfs file of the
672 event device. Instead of:
673 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
675 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
677 All the PHYSDEV* keys are deprecated and will be removed from a
679 PHYDEVPATH - is the path of a parent device and should not be
681 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
682 matched with SUBSYSTEMS==
683 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
684 Newer kernels will have DRIVER in the environment,
685 for older kernels udev puts in. Class device will
686 no longer carry this property of a parent and
687 DRIVERS== can be used to match such a parent value.
688 Note that ENV{DRIVER} is only available for a few bus devices, where
689 the driver is already bound at device event time. On coldplug, the
690 events for a lot devices are already bound to a driver, and they will have
691 that value set. But on hotplug, at the time the kernel creates the device,
692 it can't know what driver may claim the device after that, therefore
693 in most cases it will be empty.
695 Failed events should now be re-triggered with:
696 udevtrigger --retry-failed.
697 Please switch to this command, so we keep the details of the /dev/.udev/failed/
698 files private to the udev tools. We may need to switch the current symlink
699 target, cause some obviously broken tools try to scan all files in /dev
700 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
701 million times. This takes ages on slow boxes.
703 The udevinfo attribute walk (-a) now works with giving a device node
704 name (-n) instead of a devpath (-p). The query now always works, also when
705 no database file was created by udev.
707 The built-in /etc/passwd /etc/group parser is removed, we always depend on
708 getpwnam() and getgrnam() now. One of the next releases will depend on
709 fnmatch() and may use getopt_long().
713 Bugfixes and small improvements.
717 Fix path_id for recent kernels.
723 Added support for swapping network interface names, by temporarily
724 renaming the device and wait for the target name to become free.
728 The built-in MODALIAS key and substitution is removed.
732 The binary firmware helper is replaced by the usual simple
733 shell script. Udevsend is removed from the tree.
741 Some more keys require the correct use of '==' and '=' depending
742 on the kind of operation beeing an assignment or a match. Rules
743 with invalid operations are skipped and logged to syslog. Please
744 test with udevtest if the parsing of your rules throws errors and
745 fix possibly broken rules.
749 Provide "udevsettle" to wait for all current udev events to finish.
750 It also watches the current kernel netlink queue by comparing the
751 even sequence number to make sure that there are no current pending
752 events that have not already arrived in the daemon.
756 Fix rule to skip persistent rules for removable IDE devices, which
757 also skipped optical IDE drives.
759 All *_id program are installed in /lib/udev/ by default now.
761 No binary is stripped anymore as this should be done in the
762 packaging process and not at build time.
764 libvolume_id is provided as a shared library now and vol_id is
765 linked against it. Also one of the next HAL versions will require
766 this library, and the HAL build process will also require the
767 header file to be installed. The copy of the same code in HAL will
768 be removed to have only a single copy left on the system.
772 Add persistent links for SCSI tapes. The rules file is renamed
773 to 60-persistent-storage.rules.
775 Create persistent path for usb devices. Can be used for all sorts
776 of devices that can't be distinguished by other properties like
777 multiple identical keyboards and mice connected to the same box.
779 Provide "udevtrigger" program to request events on coldplug. The
780 shell script is much too slow with thousends of devices.
784 Fix persistent disk rules to exclude removable IDE drives.
786 Warn if %e, $modalias or MODALIAS is used.
790 Fix queue export, which wasn't correct for subsequent add/remove
791 events for the same device.
795 Fix cramfs detection on big endian.
797 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
802 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
803 attributes were only checked at the parent device that matched the
804 by BUS requested subsystem. Fix it to also look at the device we
805 received the event for.
807 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
812 Fix a bug where NAME="" would prevent RUN from beeing executed.
814 RUN="/bin/program" does not longer automatically add the subsystem
815 as the first parameter. This is from the days of /sbin/hotplug
816 which is dead now and it's just confusing to need to add a space at
817 the end of the program name to prevent this.
818 If you use rules that need the subsystem as the first parameter,
819 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
820 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
824 The udev man page has moved to udev(7) as it does not describe a command
825 anymore. The programs udev, udevstart and udevsend are no longer installed
826 by default and must be copied manually, if they should be installed or
827 included in a package.
829 Fix a bug where "ignore_device" could run earlier collected RUN keys before
830 the ignore rule was applied.
832 More preparation for future sysfs changes. usb_id and scsi_id no longer
833 depend on a magic order of devices in the /devices chain. Specific devices
834 should be requested by their subsytem.
836 This will always find the scsi parent device without depending on a specific
838 dev = sysfs_device_get(devpath);
839 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
841 The "device" link in the current sysfs layout will be automatically
842 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
843 parent in the devpath. If a device is requested by it's symlink, like all
844 class devices in the new sysfs layout will look like, it gets automatically
845 resolved and substituted with the real devpath and not the symlink path.
848 A similar logic must be applied to _all_ sysfs users, including
849 scripts, that search along parent devices in sysfs. The explicit use of
850 the "device" link must be avoided. With the future sysfs layout all
851 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
852 back to the "class" or the "bus". The layout of the parent devices in
853 /devices is not necessarily expected to be stable across kernel releases and
854 searching for parents by their subsystem should make sysfs users tolerant
855 for changed parent chains.
859 Prepare udev to work with the experimental kernel patch, that moves
860 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
862 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
863 moving the class devices to /sys/devices.
865 Thanks again to Marco for help finding a hopefully nice compromise
866 to make %b simpler and working again.
870 Complete removal of libsysfs, replaced by simple helper functions
871 which are much simpler and a bit faster. The udev daemon operatesentirely
872 on event parameters and does not use sysfs for simple rules anymore.
873 Please report any new bugs/problems, that may be caused by this big
874 change. They will be fixed immediately.
876 The enumeration format character '%e' is deprecated and will be
877 removed sometimes from a future udev version. It never worked correctly
878 outside of udevstart, so we can't use it with the new parallel
879 coldplug. A simple enumeration is as useless as the devfs naming
880 scheme, just get rid of both if you still use it.
882 MODALIAS and $modalias is not needed and will be removed from one of
883 the next udev versions, replace it in all rules with ENV{MODALIAS} or
884 the sysfs "modalias" value.
886 Thanks a lot to Marco for all his help on finding and fixing bugs.
890 Let scsi_id request libata drive serial numbers from page 0x80.
892 Renamed etc/udev/persistent.rules to persistent-disk.rules and
893 added /dev/disk/by-name/* for device mapper device names.
895 Removed %e from the man page. It never worked reliably outside
896 of udevstart and udevstart is no longer recommended to use.
900 Symlinks are now exported to the event environment. Hopefully it's no
901 longer needed to run udevinfo from an event process, like it was
902 mentioned on the hotplug list:
903 UDEV [1134776873.702967] add@/block/sdb
906 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
910 Fix a problem if udevsend is used as the hotplug handler and tries to use
911 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
912 and this kind of problems will hopefully go away soon.
916 All built-in logic to work around bad sysfs timing is removed with this
917 version. The need to wait for sysfs files is almost fixed with a kernel
918 version that doesn't work with this udev version anyway. Until we fix
919 the timing of the "bus" link creation, the former integrated logic should
920 be emulated by a rule placed before all other rules:
921 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
923 The option "udev_db" does no longer exist. All udev state will be in
924 /$udev_root/.udev/ now, there is no longer an option to set this
926 If the init script or something else used this value, just depend on
927 this hardcoded path. But remember _all_content_ of this directory is
928 still private to udev and can change at any time.
930 Default location for rule sripts and helper programs is now: /lib/udev/.
931 Everything that is not useful on the commandline should go into this
932 directory. Some of the helpers in the extras folder are installed there
933 now. The rules need to be changed, to find the helpers there.
935 Also /lib/udev/devices is recommended as a directory where packages or
936 the user can place real device nodes, which get copied over to /dev at
937 every boot. This should replace the various solutions with custom config
940 Udevsend does no longer start the udev daemon. This must be done with
941 the init script that prepares /dev on tmpfs and creates the initial nodes,
942 before starting the daemon.
946 Silent a too verbose error logging for the old hotplug.d/ dev.d/
949 The copy of klibc is removed. A systemwide installed version of klibc
950 should be used to build a klibc udev now.
954 NAME="" will not create any nodes, but execute RUN keys. To completely
955 ignore an event the OPTION "ignore_device" should be used.
957 After removal of the reorder queue, events with a TIMEOUT can be executed
958 without any queuing now.
962 Fixed bug in udevd, if inotify is not available. We depend on netlink
963 uevents now, kernels without that event source will not work with that
964 version of udev anymore.
968 The rule parsing happens now in the daemon once at startup, all udev
969 event processes inherit the already parsed rules from the daemon.
970 It is shipped with SUSE10.0 and reduces heavily the system load at
971 startup. The option to save precompiled rules and let the udev process
972 pick the them up is removed, as it's no longer needed.
974 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
975 device. Libsysfs is changed to "translate" the requested link into the
976 real device path, as it would happen with the hotplug event. Otherwise
977 device removal and the udev database will not work.
979 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
982 A few improvements for vol_id, the filesytem probing code.
986 Fix a stupid typo in extras/run_directory for "make install".
988 scsi_id creates the temporary devnode now in /dev for usage with a
989 non-writable /tmp directory.
991 The uevent kernel socket buffer can carry app. 50.000 events now,
992 let's see who can break this again. :)
994 The upcoming kernel will have a new input driver core integration.
995 Some class devices are now symlinks to the real device. libsysfs
996 needs a fix for this to work correctly. Udevstart of older udev
997 versions will _not_ create these devices!
1001 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1006 A bunch of mostly trivial bugfixes. From now on no node name or
1007 symlink name can contain any character than plain whitelisted ascii
1008 characters or validated utf8 byte-streams. This is needed for the
1009 /dev/disk/by-label/* links, because we import untrusted data and
1010 export it to the filesystem.
1014 More bugfixes. If udevd was started from the kernel, we don't
1015 have stdin/stdout/stderr, which broke the forked tools in some
1020 Bugfix. udevstart event ordering was broken for a long time.
1021 The new run_program() uncovered it, because /dev/null was not
1022 available while we try to run external programs.
1023 Now udevstart should create it before we run anything.
1027 Minor bugfixes and some distro rules updates. If you don't have the
1028 persistent disk rules in /dev/disk/by-*/* on your distro, just
1029 grab it from here. :)
1033 We can use socket communication now to pass events from udev to
1035 RUN+="socket:/org/freedesktop/hal/udev_event"
1036 will pass the whole udev event to the HAL daemon without the need
1037 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1041 Mostly bugfixes and see ChangeLog.
1043 The test for the existence of an environment value should be
1045 ENV{KEY}=="*" to ENV{KEY}=="?*"
1046 because "*" will not fail anymore, if the key does not exist or
1051 Bugfixes and a few tweaks described in the ChangeLog.
1055 Mostly a Bugfix release.
1057 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1058 timing with custom rules.
1062 We changed the internal rule storage format. Our large rule files took
1063 2 MB of RAM, with the change we are down to 99kB.
1065 If the device-node has been created with default name and no symlink or
1066 options are to remenber, it is not longer stored in the udevdb. HAL will
1067 need to be updated to work correctly with that change.
1069 To overrride optimization flags, OPTFLAGS may be used now.
1077 Major changes happened with this release. The goal is to take over the
1078 complete kernel-event handling and provide a more efficient way to dispatch
1079 kernel events. Replacing most of the current shell script logic and the
1080 kernel forked helper with a netlink-daemon and a rule-based event handling.
1082 o udevd listens to netlink events now. The first valid netlink event
1083 will make udevd ignore any message from udevsend that contains a
1084 SEQNUM, to avoid duplicate events. The forked events can be disabled
1086 echo "" > /proc/sys/kernel/hotplug
1087 For full support, the broken input-subsytem needs to be fixed, not to
1088 bypass the driver core.
1090 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1091 removed from udev itself and must be emulated by calling small
1092 helper binaries provided in the extras folder:
1093 make EXTRAS=extras/run_directory/
1094 will build udev_run_devd and udev_run_hotplugd, which can be called
1095 from a rule if needed:
1096 RUN+="/sbin/udev_run_hotplugd"
1097 The recommended way to handle this is to convert all the calls from
1098 the directories to explicit udev rules and get completely rid of the
1099 multiplexing. (To catch a ttyUSB event, you now no longer need to
1100 fork and exit 300 tty script instances you are not interested in, it
1101 is just one rule that matches exactly the device.)
1103 o udev handles now _all_ events not just events for class and block
1104 devices, this way it is possible to control the complete event
1105 behavior with udev rules. Especially useful for rules like:
1106 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1108 o As used in the modalias rule, udev supports now textual
1109 substitution placeholder along with the usual format chars. This
1110 needs to be documented, for now it's only visible in udev_rules_parse.c.
1112 o The rule keys support now more operations. This is documented in the
1113 man page. It is possible to add values to list-keys like the SYMLINK
1114 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1115 Also "final"-assignments are supported by using KEY:="value", which will
1116 prevent changing the key by any later rule.
1118 o kernel 2.6.12 has the "detached_state" attribute removed from
1119 sysfs, which was used to recognize sysfs population. We switched that
1120 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1121 Running this udev version on older kernels may cause a short delay for
1124 o To provide infrastructure for persistent device naming, the id programs:
1125 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1126 to export the probed data in environment key format:
1127 pim:~ # /sbin/ata_id --export /dev/hda
1128 ID_MODEL=HTS726060M9AT00
1129 ID_SERIAL=MRH401M4G6UM9B
1130 ID_REVISION=MH4OA6BA
1132 The following rules:
1133 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1134 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1137 kay@pim:~> tree /dev/disk
1140 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1141 | `-- IBM-Memory_Key -> ../../sda
1143 | |-- swap -> ../../hda1
1144 | |-- date -> ../../sda1
1145 | `-- home -> ../../hda3
1147 |-- 2E08712B0870F2E7 -> ../../hda3
1148 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1149 |-- E845-7A89 -> ../../sda1
1150 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1152 The IMPORT= operation will import these keys in the environment and make
1153 it available for later PROGRAM= and RUN= executed programs. The keys are
1154 also stored in the udevdb and can be queried from there with one of the
1157 o A few binaries are silently added to the repository, which can be used
1158 to replay kernel events from initramfs instead of using coldplug. udevd
1159 can be instructed now to queue-up events while the stored events from
1160 initramfs are filled into the udevd-queue. This code is still under
1161 development and there is no documentation now besides the code itself.
1162 The additional binaries get compiled, but are not installed by default.
1164 o There is also a temporary fix for a performance problem where too many
1165 events happen in parallel and every event needs to parse the rules.
1166 udev can now read precompiled rules stored on disk. This is likely to be
1167 replaced by a more elegant solution in a future udev version.
1171 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1172 Fix for libsysfs not to expect this file was added.
1176 All rules are applied now, but only the first matching rule with a NAME-key
1177 will be applied. All later rules with NAME-key are completely ignored. This
1178 way system supplied symlinks or permissions gets applied to user-defined
1182 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1183 to some rules, to keep the old behavior.
1185 The rules are read on "remove"-events too. That makes is possible to match
1186 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1187 instruct udev to ignore an event (OPTIONS="ignore_device").
1188 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1190 The new RUN-key supports rule-based execution of programs after device-node
1191 handling. This is meant as a general replacement for the dev.d/-directories
1192 to give fine grained control over the execution of programs.
1194 The %s{}-sysfs format char replacement values are searched at any of the
1195 devices in the device chain now, not only at the class-device.
1197 We support log priority levels now. The value udev_log in udev.conf is used
1198 to determine what is printed to syslog. This makes it possible to
1199 run a version with compiled-in debug messages in a production environment
1200 which is sometimes needed to find a bug.
1201 It is still possible to supress the inclusion of _any_ syslog usage with
1202 USE_LOG=false to create the smallest possible binaries if needed.
1203 The configured udev_log value can be overridden with the environment variable
1208 Possible use of a system-wide klibc:
1209 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1210 will link against an external klibc and our own version will be ignored.
1214 We support an unlimited count of symlinks now.
1216 If USE_STATIC=true is passed to a glibc build, we link statically and use
1217 a built-in userdb parser to resolve user and group names.
1219 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1220 we walk up the chain of physical devices to find a match.
1222 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1223 easy to skip certain attribute matches without composing rules with weird
1224 character class negations like:
1225 KERNEL="[!s][!c][!d]*"
1226 this can now be replaced with:
1228 The current simple '=' is still supported, and should work as it does today,
1229 but existing rules should be converted if possible, to be better readable.
1231 We have new ENV{}== key now, to match against a maximum of 5 environment
1234 udevstart is its own binary again, because we don't need co carry this araound
1235 with every forked event.
~ianmdlvl / elogind.git / blob