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
20 The udevadm trigger "--retry-failed" option, which is replaced since quite
21 a while by "--type=failed" is removed.
23 The failed tracking was not working at all for a few releases. The RUN
24 option "ignore_error" is replaced by a "fail_event_on_error" option, and the
25 default is not to track any failing RUN executions.
27 New keymaps, new modem, hid2hci updated.
31 Fix possible crash in udevd when worker processes are busy, rules are
32 changed at the same time, and workers get killed to reload the rules.
38 Properties set with ENV{.FOO}="bar" are marked private by starting the
39 name with a '.'. They will not be stored in the database, and not be
40 exported with the event.
42 Firmware files are looked up in:
43 /lib/firmware/updates/$(uname -r)
45 /lib/firmware/$(uname -r)
49 ATA devices switched the property from ID_BUS=scsi to ID_BUS=ata.
50 ata_id, instead of scsi_id, is the default tool now for ATA devices.
56 The configure options have changed because another library needs to be
57 installed in a different location. Instead of exec_prefix and udev_prefix,
58 libdir, rootlibdir and libexecdir are used. The Details are explained in
61 Event processes now get re-used after they handled an event. This reduces
62 the number of forks and the pressure on the CPU significantly, because
63 cloned event processes no longer cause page faults in the main daemon.
64 After the events have settled, a few worker processes stay around for
65 future events, all others get cleaned up.
67 To be able to use signalfd(), udev depends on kernel version 2.6.25 now.
68 Also inotify support is mandatory now to run udev.
70 The format of the queue exported by the udev damon has changed. There is
71 no longer a /dev/.udev/queue/ directory. The current event queue can be
72 accessed with udevadm settle and libudedv.
74 Libudev does not have the unstable API header anymore. From now on,
75 incompatible changes will be handled by bumping the library major version.
77 To build udev from the git tree gtk-doc is needed now. The tarballs will
78 build without it and contain the pre-built documentation. An online copy
80 http://www.kernel.org/pub/linux/utils/kernel/hotplug/libudev/
82 The tools from the udev-extras repository have been merged into the main
83 udev repository. Some of the extras have larger external dependencies, and
84 they can be disabled with the configure switch --disable-extras.
90 The program vol_id and the library libvolume_id are removed from the
91 repository. Libvolume_id is merged with libblkid from the util-linux-ng
92 package. Persistent disk links for label and uuid depend on the
93 util-linux-ng version (2.15) of blkid now. Older versions of blkid
94 can not be used with udev.
96 Libudev allows to subscribe to udev events. To prevent unwanted messages
97 to be delivered, and waking up the subscribing process, a filter can be
98 installed, to drop messages inside a kernel socket filter. The filters
99 match on the <subsytem>:<devtype> properties of the device.
100 This is part of the ongoing effort to replace HAL, and switch current
101 users over to directly use libudev.
102 Libudev is still marked as experimental, and its interface might
103 eventually change if needed, but no major changes of the currently exported
104 interface are expected anymore, and a first stable release should happen
107 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
108 is not supported since while and udevd will log an error message at
109 startup. It should still be able to boot-up, but advanced rules and system
110 services which depend on the information not available in the old sysfs
111 format will fail to work correctly.
113 DVB device naming is supplied by the kernel now. In case older kernels
114 need to be supported, the old shell script should be added to a compat
121 The processed udev events get send back to the netlink socket. Libudev
122 provides access to these events. This is work-in-progress, to replace
123 the DeviceKit daemon functionality directly with libudev. There are
124 upcoming kernel changes to allow non-root users to subcribe to these
131 "udevadm settle" now optionally accepts a range of events to wait for,
132 instead of waiting for "all" events.
138 The installed watch for block device metadata changes is now removed
139 during event hadling, because some (broken) tools may be called from udev
140 rules and (wrongly) open the device with write access. After the finished
141 event handling the watch is restored.
147 Device nodes can be watched for changes with inotify with OPTIONS="watch".
148 If closed after being opened for writing, a "change" uevent will occur.
149 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
155 The udevadm test command has no longer a --force option, nodes and symlinks
156 are always updated with a test run now.
158 The udevd daemon can be started with --resolve-names=never to avoid all user
159 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
160 lookup user and groups every time events are handled.
166 We are currently merging the Ubuntu rules in the udev default rules,
167 and get one step closer to provide a common Linux /dev setup, regarding
168 device names, symlinks, and default device permissions. On udev startup,
169 we now expect the following groups to be resolvable to their ids with
171 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
172 LDAP setups need to make sure, that these groups are always resolvable at
173 bootup, with only the rootfs mounted, and without network access available.
175 Some systems may need to add some new, currently not used groups, or need
176 to add some users to new groups, but the cost of this change is minimal,
177 compared to the pain the current, rather random, differences between the
178 various distributions cause for upstream projects and third-party vendors.
180 In general, "normal" users who log into a machine should never be a member
181 of any such group, but the device-access should be managed by dynamic ACLs,
182 which get added and removed for the specific users on login/logout and
183 session activity/inactivity. These groups are only provided for custom setups,
184 and mainly system services, to allow proper privilege separation.
185 A video-streaming daemon uid would be a member of "audio" and "video", to get
186 access to the sound and video devices, but no "normal" user should ever belong
187 to the "audio" group, because he could listen to the built-in microphone with
188 any ssh-session established from the other side of the world.
190 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
191 which do not depend on the kernel device name. As usual, unique
192 devices - only a single one per product connected, or a real
193 USB serial number in the device - are always found with the same
194 name in the by-id/ directory.
195 Completely identical devices may overwrite their names in by-id/
196 and can only be found reliably in the by-path/ directory. Devices
197 specified by by-path/ must not change their connection, like the
198 USB port number they are plugged in, to keep their name.
200 To support some advanced features, Linux 2.6.22 is the oldest supported
201 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
202 supported. Older kernels should still work, and devices nodes should be
203 reliably created, but some rules and libudev will not work correctly because
204 the old kernels do not provide the expected information or interfaces.
210 Fix for a possible segfault while swapping network interface names in udev
217 The group "video" is part of the default rules now.
221 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
222 block devices in some cases. No common distro uses this option anymore,
223 and we do not get enough testing for this and recent udev versions. If
224 this option is not needed to run some old distro with a new kernel,
225 it should be disabled in the kernel config.
227 Bugfix for the $links substitution variable, which may crash if no links
228 are created. This should not happen in usual setups because we always
229 create /dev/{block,char}/ links.
231 The strings of the parsed rules, which are kept in memory, no longer
232 contain duplicate entries, or duplicate tails of strings. This, and the
233 new rules parsing/matching code reduces the total in-memory size of
234 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
237 The export of DEVTYPE=disk/partition got removed from the default
238 rules. This value is available from the kernel. The pnp shell script
239 modprobe hack is removed from the default rules. ACPI devices have _proper_
240 modalias support and take care of the same functionality.
241 Installations which support old kernels, but install current default
242 udev rules may want to add that to the compat rules file.
244 Libvolume_id now always probes for all known filesystems, and does not
245 stop at the first match. Some filesystems are marked as "exclusive probe",
246 and if any other filesytem type matches at the same time, libvolume_id
247 will, by default, not return any probing result. This is intended to prevent
248 mis-detection with conflicting left-over signatures found from earlier
249 file system formats. That way, we no longer depend on the probe-order
250 in case of multiple competing signatures. In some setups the kernel allows
251 to mount a volume with just the old filesystem signature still in place.
252 This may damage the new filesystem and cause data-loss, just by mounting
253 it. Because volume_id can not decide which one the correct signature is,
254 the wrong signatures need to be removed manually from the volume, or the
255 volume needs to be reformatted, to enable filesystem detection and possible
260 Fix segfault if compiled without optimization and dbg() does not get
261 compiled out and uses variables which are not available.
265 Bugfixes. (And maybe new bugs. :))
267 The rule matching engine got converted from a rule list to a token
268 array which reduced the in-memory rules representation of a full
269 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
270 Limits like 5 ENV and ATTR matches, and one single instance for most
271 other keys per rule are gone.
273 The NAME assignment is no longer special cased. If later rules assign
274 a NAME value again, the former value will be overwritten. As usual
275 for most other keys, the NAME value can be protected by doing a final
276 assignment with NAME:="<value>".
278 All udev code now uses libudev, which is also exported. The library
279 is still under development, marked as experimental, and its interface
280 may change as long as the DeviceKit integration is not finished.
282 Many thanks to Alan Jenkins for his continuous help, and finding and
283 optimizing some of the computing expensive parts.
289 Kernel devices and device nodes are connected now by reverse indizes in
290 /sys and /dev. A device number retrieved by a stat() or similar, the
291 kernel device directory can be found by looking up:
292 /sys/dev/{block,char}/<maj>:<min>
293 and the device node of the same device by looking up:
294 /dev/{block,char}/<maj>:<min>
298 Fix recently introduced bug, which caused a compilation without large
299 file support, where vol_id does not recognize raid signatures at the end
302 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
303 Seems some kernel versions prevent the creation of the ieee-* links,
304 so people used the scsi-* link which disappeared now.
306 More libudev work. Almost all udevadm functionality comes from libudev
309 udevadm trigger has a new option --type, which allows to trigger events
310 for "devices", for "subsystems", or "failed" devices. The old option
311 --retry-failed" still works, but is no longer mentioned in the man page.
317 The udevadm info --device-id-of-file= output has changed to use
318 the obvious format. Possible current users should use the --export
319 option which is not affected.
321 The old udev commands symlinks to udevadm are not installed, if
322 these symlinks are used, a warning is printed.
328 Optical drive's media is no longer probed for raid signatures,
329 reading the end of the device causes some devices to malfunction.
330 Also the offset of the last session found is used now to probe
333 The volume_id library got a major version number update to 1,
334 some deprecated functions are removed.
336 A shared library "libudev" gets installed now to provide access
337 to udev device information. DeviceKit, the successor of HAL, will
338 need this library to access the udev database and search sysfs for
340 The library is currently in an experimental state, also the API is
341 expected to change, as long as the DeviceKit integration is not
346 We use ./configure now. See INSTALL for details. Current
349 "/usr" - prefix for man pages, include files
351 "" - the root filesystem, prefix for libs and binaries
355 "lib" - directory name for libraries, not a path name
356 multilib 64bit systems may use "lib64" instead of "lib"
358 compile-in verbose debug messages
360 disable all logging and compile-out all log strings
362 link against SELInux libraries, to set the expected context
365 In the default rules, the group "disk" gets permissions 0660 instead
366 of 0640. One small step closer to unify distro rules. Some day, all
367 distros hopefully end up with the same set of rules.
369 No symlinks to udevadm are installed anymore, if they are still needed,
370 they should be provided by the package.
376 Default udev rules, which are not supposed to be edited by the user, should
377 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
378 the udev package and will be replaced with an update. Udev will pick up rule
380 /lib/udev/rules.d/ - default installed rules
381 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
382 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
383 It does not matter in which directory a rule file lives, all files are sorted
386 To help creating /dev/root, we have now:
387 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
390 In case the current --device-id-of-file is already used, please switch to
391 the --export format version, it saves the output parsing and the old
392 format will be changed to use ':' as a separator, like the format in the
397 Fix cdrom_id to properly recognize blank media.
403 Tape drive id-data is queried from /dev/bsg/* instead of the tape
404 nodes. This avoids rewinding tapes on open().
410 The symlinks udevcontrol and udevtrigger are no longer installed by
413 The scsi_id program does not depend on sysfs anymore. It can speak
414 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
415 data, which should solve some old problems with tape devices, where
416 we better do not open all tape device nodes to identify the device.
422 The cdrom_id program is replaced by an advanced version, which can
423 detect most common device types, and also properties of the inserted
424 media. This is part of moving some basic functionality from HAL into
425 udev (and the kernel).
431 The last WAIT_FOR_SYSFS rule is removed from the default rules.
433 The symlinks to udevadm for the debugging tools: udevmonitor and
434 udevtest are no longer created.
436 The symlinks to the udevadm man page for the old tool names are
439 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
440 should be prefixed with '@' to indicate that the path is not a
451 Udevstart is removed from the tree, it did not get installed for
452 a long time now, and is long replaced by trigger and settle.
458 All udev tools are merged into a single binary called udevadm.
459 The old names of the tools are built-in commands in udevadm now.
460 Symlinks to udevadm, with the names of the old tools, provide
461 the same functionality as the standalone tools. There is also
462 only a single udevadm.8 man page left for all tools.
464 Tools like mkinitramfs should be checked, if they need to include
465 udevadm in the list of files.
475 The etc/udev/rules.d/ directory now contains a default set of basic
476 udev rules. This initial version is the result of a rules file merge
477 of Fedora and openSUSE. For these both distros only a few specific
478 rules are left in their own file, named after the distro. Rules which
479 are optionally installed, because they are only valid for a specific
480 architecture, or rules for subsystems which are not always used are
481 in etc/udev/packages/.
487 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
488 actions by dynamically created rules.
490 SYMLINK=="<value>" matches agains the entries in the list of
491 currently defined symlinks. The links are not created in the
492 filesystem at that point in time, but the values can be matched.
494 RUN{ignore_error}+="<program>" will ignore any exit code from the
495 program and not record as a failed event.
501 Final merge of patches/features from the Ubuntu package.
507 Control characters in filesystem label strings are no longer silenty
508 removed, but hex-encoded, to be able to uniquely identify the device
509 by its symlink in /dev/disk/by-label/.
510 If libvolume_id is used by mount(8), LABEL= will work as expected,
511 if slashes or other characters are used in the label string.
513 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
514 can be specified now. The TEST key accepts an optional mode mask
515 TEST{0100}=="<is executable file>".
517 Scsi_id now supports a mode without expecting scsi-specific sysfs
518 entries to allow the extraction of cciss-device persistent properties.
524 In the future, we may see uuid's which are just simple character
525 strings (see the DDF Raid Specification). For that reason vol_id now
526 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
527 the creation of symlinks, the *_SAFE values ensure, that no control
528 or whitespace characters are used in the filename.
530 Possible users of libvolume_id, please use the volume_id_get_* functions.
531 The public struct will go away in a future release of the library.
537 Removal of useless extras/eventrecorder.sh.
547 The directory multiplexer for dev.d/ and hotplug.d are finally removed
548 from the udev package.
554 Symlinks can have priorities now, the priority is assigned to the device
555 and specified with OPTIONS="link_priority=100". Devices with higher
556 priorities overwrite the symlinks of devices with lower priorities.
557 If the device that currently owns the link, goes away, the symlink
558 will be removed, and recreated, pointing to the next device with the
559 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
560 more reliable, if multiple devices contain the same metadata and overwrite
563 The dasd_id program is removed from the udev tree, and dasdinfo, with the
564 needed rules, are part of the s390-tools now.
566 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
567 we may get the scsi sysfs mess fixed some day, and this will only catch
568 the devices we are looking for.
570 USB serial numbers for storage devices have the target:lun now appended,
571 to make it possibble to distinguish broken multi-lun devices with all
572 the same SCSI identifiers.
574 Note: The extra "run_directory" which searches and executes stuff in
575 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
576 with the next release. Make sure, that you don't use it anymore, or
577 provides your own implementation of that inefficient stuff.
578 We are tired of reports about a "slow udev", because these directories
579 contain stuff, that runs with _every_ event, instead of using rules,
580 that run programs only for the matching events.
590 DRIVER== will match only for devices that actually have a real
591 driver. DRIVERS== must be used, if parent devices should be
592 included in the match.
594 Libvolume_id's "linux_raid" detection needed another fix.
602 Add additional check to volume_id detection of via_raid, cause
603 some company decided to put a matching pattern all over the empty
604 storage area of their music players.
608 Fix path_id for SAS devices.
612 The udev daemon can be started with --debug-trace now, which will
613 execute all events serialized to get a chance to catch a possible
614 action that crashes the box.
616 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
617 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
618 are excluded from the warning. Referencing parent attributes directly
619 may break when something in the kernel driver model changes. Udev will
620 just find the attribute by walking up the parent chain.
622 Udevtrigger now sorts the list of devices depending on the device
623 dependency, so a "usb" device is triggered after the parent "pci"
628 Revert persistent-storage ata-serial '_' '-' replacement.
634 Udevtrigger can now filter the list of devices to be triggered. Matches
635 for subsystems or sysfs attributes can be specified.
637 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
638 zero-sized files to avoid pointing to /sys and confuse broken tools which
639 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
642 The rules and scripts to create udev rules for persistent network
643 devices and optical drives are in the extras/rules_generator directory
644 now. If you use something similar, please consider replacing your own
645 version with this, to share the support effort. The rule_generator
646 installs its own rules into /etc/udev/rules.d.
648 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
649 the rule_generator depends on cdrom_id to be called in an earlier rule.
655 Renaming of some key names (the old names still work):
656 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
657 (The behavior of the key DRIVER will change soon in one of the next
658 releases, to match only the event device, please switch to DRIVERS
659 instead. If DRIVER is used, it will behave like DRIVERS, but an error
661 With the new key names, we have a more consistent and simpler scheme.
662 We can match the properties of the event device only, with: KERNEL,
663 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
664 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
665 longer mentioned in the man page and should be switched in the rule
668 ATTR{file}="value" can be used now, to write to a sysfs file of the
669 event device. Instead of:
670 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
672 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
674 All the PHYSDEV* keys are deprecated and will be removed from a
676 PHYDEVPATH - is the path of a parent device and should not be
678 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
679 matched with SUBSYSTEMS==
680 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
681 Newer kernels will have DRIVER in the environment,
682 for older kernels udev puts in. Class device will
683 no longer carry this property of a parent and
684 DRIVERS== can be used to match such a parent value.
685 Note that ENV{DRIVER} is only available for a few bus devices, where
686 the driver is already bound at device event time. On coldplug, the
687 events for a lot devices are already bound to a driver, and they will have
688 that value set. But on hotplug, at the time the kernel creates the device,
689 it can't know what driver may claim the device after that, therefore
690 in most cases it will be empty.
692 Failed events should now be re-triggered with:
693 udevtrigger --retry-failed.
694 Please switch to this command, so we keep the details of the /dev/.udev/failed/
695 files private to the udev tools. We may need to switch the current symlink
696 target, cause some obviously broken tools try to scan all files in /dev
697 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
698 million times. This takes ages on slow boxes.
700 The udevinfo attribute walk (-a) now works with giving a device node
701 name (-n) instead of a devpath (-p). The query now always works, also when
702 no database file was created by udev.
704 The built-in /etc/passwd /etc/group parser is removed, we always depend on
705 getpwnam() and getgrnam() now. One of the next releases will depend on
706 fnmatch() and may use getopt_long().
710 Bugfixes and small improvements.
714 Fix path_id for recent kernels.
720 Added support for swapping network interface names, by temporarily
721 renaming the device and wait for the target name to become free.
725 The built-in MODALIAS key and substitution is removed.
729 The binary firmware helper is replaced by the usual simple
730 shell script. Udevsend is removed from the tree.
738 Some more keys require the correct use of '==' and '=' depending
739 on the kind of operation beeing an assignment or a match. Rules
740 with invalid operations are skipped and logged to syslog. Please
741 test with udevtest if the parsing of your rules throws errors and
742 fix possibly broken rules.
746 Provide "udevsettle" to wait for all current udev events to finish.
747 It also watches the current kernel netlink queue by comparing the
748 even sequence number to make sure that there are no current pending
749 events that have not already arrived in the daemon.
753 Fix rule to skip persistent rules for removable IDE devices, which
754 also skipped optical IDE drives.
756 All *_id program are installed in /lib/udev/ by default now.
758 No binary is stripped anymore as this should be done in the
759 packaging process and not at build time.
761 libvolume_id is provided as a shared library now and vol_id is
762 linked against it. Also one of the next HAL versions will require
763 this library, and the HAL build process will also require the
764 header file to be installed. The copy of the same code in HAL will
765 be removed to have only a single copy left on the system.
769 Add persistent links for SCSI tapes. The rules file is renamed
770 to 60-persistent-storage.rules.
772 Create persistent path for usb devices. Can be used for all sorts
773 of devices that can't be distinguished by other properties like
774 multiple identical keyboards and mice connected to the same box.
776 Provide "udevtrigger" program to request events on coldplug. The
777 shell script is much too slow with thousends of devices.
781 Fix persistent disk rules to exclude removable IDE drives.
783 Warn if %e, $modalias or MODALIAS is used.
787 Fix queue export, which wasn't correct for subsequent add/remove
788 events for the same device.
792 Fix cramfs detection on big endian.
794 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
799 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
800 attributes were only checked at the parent device that matched the
801 by BUS requested subsystem. Fix it to also look at the device we
802 received the event for.
804 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
809 Fix a bug where NAME="" would prevent RUN from beeing executed.
811 RUN="/bin/program" does not longer automatically add the subsystem
812 as the first parameter. This is from the days of /sbin/hotplug
813 which is dead now and it's just confusing to need to add a space at
814 the end of the program name to prevent this.
815 If you use rules that need the subsystem as the first parameter,
816 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
817 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
821 The udev man page has moved to udev(7) as it does not describe a command
822 anymore. The programs udev, udevstart and udevsend are no longer installed
823 by default and must be copied manually, if they should be installed or
824 included in a package.
826 Fix a bug where "ignore_device" could run earlier collected RUN keys before
827 the ignore rule was applied.
829 More preparation for future sysfs changes. usb_id and scsi_id no longer
830 depend on a magic order of devices in the /devices chain. Specific devices
831 should be requested by their subsytem.
833 This will always find the scsi parent device without depending on a specific
835 dev = sysfs_device_get(devpath);
836 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
838 The "device" link in the current sysfs layout will be automatically
839 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
840 parent in the devpath. If a device is requested by it's symlink, like all
841 class devices in the new sysfs layout will look like, it gets automatically
842 resolved and substituted with the real devpath and not the symlink path.
845 A similar logic must be applied to _all_ sysfs users, including
846 scripts, that search along parent devices in sysfs. The explicit use of
847 the "device" link must be avoided. With the future sysfs layout all
848 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
849 back to the "class" or the "bus". The layout of the parent devices in
850 /devices is not necessarily expected to be stable across kernel releases and
851 searching for parents by their subsystem should make sysfs users tolerant
852 for changed parent chains.
856 Prepare udev to work with the experimental kernel patch, that moves
857 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
859 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
860 moving the class devices to /sys/devices.
862 Thanks again to Marco for help finding a hopefully nice compromise
863 to make %b simpler and working again.
867 Complete removal of libsysfs, replaced by simple helper functions
868 which are much simpler and a bit faster. The udev daemon operatesentirely
869 on event parameters and does not use sysfs for simple rules anymore.
870 Please report any new bugs/problems, that may be caused by this big
871 change. They will be fixed immediately.
873 The enumeration format character '%e' is deprecated and will be
874 removed sometimes from a future udev version. It never worked correctly
875 outside of udevstart, so we can't use it with the new parallel
876 coldplug. A simple enumeration is as useless as the devfs naming
877 scheme, just get rid of both if you still use it.
879 MODALIAS and $modalias is not needed and will be removed from one of
880 the next udev versions, replace it in all rules with ENV{MODALIAS} or
881 the sysfs "modalias" value.
883 Thanks a lot to Marco for all his help on finding and fixing bugs.
887 Let scsi_id request libata drive serial numbers from page 0x80.
889 Renamed etc/udev/persistent.rules to persistent-disk.rules and
890 added /dev/disk/by-name/* for device mapper device names.
892 Removed %e from the man page. It never worked reliably outside
893 of udevstart and udevstart is no longer recommended to use.
897 Symlinks are now exported to the event environment. Hopefully it's no
898 longer needed to run udevinfo from an event process, like it was
899 mentioned on the hotplug list:
900 UDEV [1134776873.702967] add@/block/sdb
903 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
907 Fix a problem if udevsend is used as the hotplug handler and tries to use
908 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
909 and this kind of problems will hopefully go away soon.
913 All built-in logic to work around bad sysfs timing is removed with this
914 version. The need to wait for sysfs files is almost fixed with a kernel
915 version that doesn't work with this udev version anyway. Until we fix
916 the timing of the "bus" link creation, the former integrated logic should
917 be emulated by a rule placed before all other rules:
918 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
920 The option "udev_db" does no longer exist. All udev state will be in
921 /$udev_root/.udev/ now, there is no longer an option to set this
923 If the init script or something else used this value, just depend on
924 this hardcoded path. But remember _all_content_ of this directory is
925 still private to udev and can change at any time.
927 Default location for rule sripts and helper programs is now: /lib/udev/.
928 Everything that is not useful on the commandline should go into this
929 directory. Some of the helpers in the extras folder are installed there
930 now. The rules need to be changed, to find the helpers there.
932 Also /lib/udev/devices is recommended as a directory where packages or
933 the user can place real device nodes, which get copied over to /dev at
934 every boot. This should replace the various solutions with custom config
937 Udevsend does no longer start the udev daemon. This must be done with
938 the init script that prepares /dev on tmpfs and creates the initial nodes,
939 before starting the daemon.
943 Silent a too verbose error logging for the old hotplug.d/ dev.d/
946 The copy of klibc is removed. A systemwide installed version of klibc
947 should be used to build a klibc udev now.
951 NAME="" will not create any nodes, but execute RUN keys. To completely
952 ignore an event the OPTION "ignore_device" should be used.
954 After removal of the reorder queue, events with a TIMEOUT can be executed
955 without any queuing now.
959 Fixed bug in udevd, if inotify is not available. We depend on netlink
960 uevents now, kernels without that event source will not work with that
961 version of udev anymore.
965 The rule parsing happens now in the daemon once at startup, all udev
966 event processes inherit the already parsed rules from the daemon.
967 It is shipped with SUSE10.0 and reduces heavily the system load at
968 startup. The option to save precompiled rules and let the udev process
969 pick the them up is removed, as it's no longer needed.
971 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
972 device. Libsysfs is changed to "translate" the requested link into the
973 real device path, as it would happen with the hotplug event. Otherwise
974 device removal and the udev database will not work.
976 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
979 A few improvements for vol_id, the filesytem probing code.
983 Fix a stupid typo in extras/run_directory for "make install".
985 scsi_id creates the temporary devnode now in /dev for usage with a
986 non-writable /tmp directory.
988 The uevent kernel socket buffer can carry app. 50.000 events now,
989 let's see who can break this again. :)
991 The upcoming kernel will have a new input driver core integration.
992 Some class devices are now symlinks to the real device. libsysfs
993 needs a fix for this to work correctly. Udevstart of older udev
994 versions will _not_ create these devices!
998 Fix a 'install' target in the Makefile, that prevents EXTRAS from
1003 A bunch of mostly trivial bugfixes. From now on no node name or
1004 symlink name can contain any character than plain whitelisted ascii
1005 characters or validated utf8 byte-streams. This is needed for the
1006 /dev/disk/by-label/* links, because we import untrusted data and
1007 export it to the filesystem.
1011 More bugfixes. If udevd was started from the kernel, we don't
1012 have stdin/stdout/stderr, which broke the forked tools in some
1017 Bugfix. udevstart event ordering was broken for a long time.
1018 The new run_program() uncovered it, because /dev/null was not
1019 available while we try to run external programs.
1020 Now udevstart should create it before we run anything.
1024 Minor bugfixes and some distro rules updates. If you don't have the
1025 persistent disk rules in /dev/disk/by-*/* on your distro, just
1026 grab it from here. :)
1030 We can use socket communication now to pass events from udev to
1032 RUN+="socket:/org/freedesktop/hal/udev_event"
1033 will pass the whole udev event to the HAL daemon without the need
1034 for a forked helper. (See ChangeLog for udevmonitor, as an example)
1038 Mostly bugfixes and see ChangeLog.
1040 The test for the existence of an environment value should be
1042 ENV{KEY}=="*" to ENV{KEY}=="?*"
1043 because "*" will not fail anymore, if the key does not exist or
1048 Bugfixes and a few tweaks described in the ChangeLog.
1052 Mostly a Bugfix release.
1054 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
1055 timing with custom rules.
1059 We changed the internal rule storage format. Our large rule files took
1060 2 MB of RAM, with the change we are down to 99kB.
1062 If the device-node has been created with default name and no symlink or
1063 options are to remenber, it is not longer stored in the udevdb. HAL will
1064 need to be updated to work correctly with that change.
1066 To overrride optimization flags, OPTFLAGS may be used now.
1074 Major changes happened with this release. The goal is to take over the
1075 complete kernel-event handling and provide a more efficient way to dispatch
1076 kernel events. Replacing most of the current shell script logic and the
1077 kernel forked helper with a netlink-daemon and a rule-based event handling.
1079 o udevd listens to netlink events now. The first valid netlink event
1080 will make udevd ignore any message from udevsend that contains a
1081 SEQNUM, to avoid duplicate events. The forked events can be disabled
1083 echo "" > /proc/sys/kernel/hotplug
1084 For full support, the broken input-subsytem needs to be fixed, not to
1085 bypass the driver core.
1087 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1088 removed from udev itself and must be emulated by calling small
1089 helper binaries provided in the extras folder:
1090 make EXTRAS=extras/run_directory/
1091 will build udev_run_devd and udev_run_hotplugd, which can be called
1092 from a rule if needed:
1093 RUN+="/sbin/udev_run_hotplugd"
1094 The recommended way to handle this is to convert all the calls from
1095 the directories to explicit udev rules and get completely rid of the
1096 multiplexing. (To catch a ttyUSB event, you now no longer need to
1097 fork and exit 300 tty script instances you are not interested in, it
1098 is just one rule that matches exactly the device.)
1100 o udev handles now _all_ events not just events for class and block
1101 devices, this way it is possible to control the complete event
1102 behavior with udev rules. Especially useful for rules like:
1103 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1105 o As used in the modalias rule, udev supports now textual
1106 substitution placeholder along with the usual format chars. This
1107 needs to be documented, for now it's only visible in udev_rules_parse.c.
1109 o The rule keys support now more operations. This is documented in the
1110 man page. It is possible to add values to list-keys like the SYMLINK
1111 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1112 Also "final"-assignments are supported by using KEY:="value", which will
1113 prevent changing the key by any later rule.
1115 o kernel 2.6.12 has the "detached_state" attribute removed from
1116 sysfs, which was used to recognize sysfs population. We switched that
1117 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1118 Running this udev version on older kernels may cause a short delay for
1121 o To provide infrastructure for persistent device naming, the id programs:
1122 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1123 to export the probed data in environment key format:
1124 pim:~ # /sbin/ata_id --export /dev/hda
1125 ID_MODEL=HTS726060M9AT00
1126 ID_SERIAL=MRH401M4G6UM9B
1127 ID_REVISION=MH4OA6BA
1129 The following rules:
1130 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1131 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1134 kay@pim:~> tree /dev/disk
1137 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1138 | `-- IBM-Memory_Key -> ../../sda
1140 | |-- swap -> ../../hda1
1141 | |-- date -> ../../sda1
1142 | `-- home -> ../../hda3
1144 |-- 2E08712B0870F2E7 -> ../../hda3
1145 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1146 |-- E845-7A89 -> ../../sda1
1147 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1149 The IMPORT= operation will import these keys in the environment and make
1150 it available for later PROGRAM= and RUN= executed programs. The keys are
1151 also stored in the udevdb and can be queried from there with one of the
1154 o A few binaries are silently added to the repository, which can be used
1155 to replay kernel events from initramfs instead of using coldplug. udevd
1156 can be instructed now to queue-up events while the stored events from
1157 initramfs are filled into the udevd-queue. This code is still under
1158 development and there is no documentation now besides the code itself.
1159 The additional binaries get compiled, but are not installed by default.
1161 o There is also a temporary fix for a performance problem where too many
1162 events happen in parallel and every event needs to parse the rules.
1163 udev can now read precompiled rules stored on disk. This is likely to be
1164 replaced by a more elegant solution in a future udev version.
1168 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1169 Fix for libsysfs not to expect this file was added.
1173 All rules are applied now, but only the first matching rule with a NAME-key
1174 will be applied. All later rules with NAME-key are completely ignored. This
1175 way system supplied symlinks or permissions gets applied to user-defined
1179 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1180 to some rules, to keep the old behavior.
1182 The rules are read on "remove"-events too. That makes is possible to match
1183 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1184 instruct udev to ignore an event (OPTIONS="ignore_device").
1185 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1187 The new RUN-key supports rule-based execution of programs after device-node
1188 handling. This is meant as a general replacement for the dev.d/-directories
1189 to give fine grained control over the execution of programs.
1191 The %s{}-sysfs format char replacement values are searched at any of the
1192 devices in the device chain now, not only at the class-device.
1194 We support log priority levels now. The value udev_log in udev.conf is used
1195 to determine what is printed to syslog. This makes it possible to
1196 run a version with compiled-in debug messages in a production environment
1197 which is sometimes needed to find a bug.
1198 It is still possible to supress the inclusion of _any_ syslog usage with
1199 USE_LOG=false to create the smallest possible binaries if needed.
1200 The configured udev_log value can be overridden with the environment variable
1205 Possible use of a system-wide klibc:
1206 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1207 will link against an external klibc and our own version will be ignored.
1211 We support an unlimited count of symlinks now.
1213 If USE_STATIC=true is passed to a glibc build, we link statically and use
1214 a built-in userdb parser to resolve user and group names.
1216 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1217 we walk up the chain of physical devices to find a match.
1219 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1220 easy to skip certain attribute matches without composing rules with weird
1221 character class negations like:
1222 KERNEL="[!s][!c][!d]*"
1223 this can now be replaced with:
1225 The current simple '=' is still supported, and should work as it does today,
1226 but existing rules should be converted if possible, to be better readable.
1228 We have new ENV{}== key now, to match against a maximum of 5 environment
1231 udevstart is its own binary again, because we don't need co carry this araound
1232 with every forked event.
~ianmdlvl / elogind.git / blob