9 The program vol_id and the library libvolume_id are removed from the
10 repository. Libvolume_id is merged with libblkid from the util-linux-ng
11 package. Persistent disk links for label and uuid depend on the
12 util-linux-ng version (2.15) of blkid now. Older versions of blkid
13 can not be used with udev.
15 Libudev allows to subscribe to udev events. To prevent unwanted messages
16 to be delivered, and waking up the subscribing process, a filter can be
17 installed, to drop messages inside a kernel socket filter. The filters
18 match on the <subsytem>:<devtype> properties of the device.
19 This is part of the ongoing effort to replace HAL, and switch current
20 users over to directly use libudev.
21 Libudev is still marked as experimental, and its interface might
22 eventually change if needed, but no major changes of the currently exported
23 interface are expected anymore, and a first stable release should happen
26 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
27 is not supported since while and udevd will log an error message at
28 startup. It should still be able to boot-up, but advanced rules and system
29 services which depend on the information not available in the old sysfs
30 format will fail to work correctly.
32 DVB device naming is supplied by the kernel now. In case older kernels
33 need to be supported, the old shell script should be added to a compat
40 The processed udev events get send back to the netlink socket. Libudev
41 provides access to these events. This is work-in-progress, to replace
42 the DeviceKit daemon functionality directly with libudev. There are
43 upcoming kernel changes to allow non-root users to subcribe to these
50 "udevadm settle" now optionally accepts a range of events to wait for,
51 instead of waiting for "all" events.
57 The installed watch for block device metadata changes is now removed
58 during event hadling, because some (broken) tools may be called from udev
59 rules and (wrongly) open the device with write access. After the finished
60 event handling the watch is restored.
66 Device nodes can be watched for changes with inotify with OPTIONS="watch".
67 If closed after being opened for writing, a "change" uevent will occur.
68 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
74 The udevadm test command has no longer a --force option, nodes and symlinks
75 are always updated with a test run now.
77 The udevd daemon can be started with --resolve-names=never to avoid all user
78 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
79 lookup user and groups every time events are handled.
85 We are currently merging the Ubuntu rules in the udev default rules,
86 and get one step closer to provide a common Linux /dev setup, regarding
87 device names, symlinks, and default device permissions. On udev startup,
88 we now expect the following groups to be resolvable to their ids with
90 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
91 LDAP setups need to make sure, that these groups are always resolvable at
92 bootup, with only the rootfs mounted, and without network access available.
94 Some systems may need to add some new, currently not used groups, or need
95 to add some users to new groups, but the cost of this change is minimal,
96 compared to the pain the current, rather random, differences between the
97 various distributions cause for upstream projects and third-party vendors.
99 In general, "normal" users who log into a machine should never be a member
100 of any such group, but the device-access should be managed by dynamic ACLs,
101 which get added and removed for the specific users on login/logout and
102 session activity/inactivity. These groups are only provided for custom setups,
103 and mainly system services, to allow proper privilege separation.
104 A video-streaming daemon uid would be a member of "audio" and "video", to get
105 access to the sound and video devices, but no "normal" user should ever belong
106 to the "audio" group, because he could listen to the built-in microphone with
107 any ssh-session established from the other side of the world.
109 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
110 which do not depend on the kernel device name. As usual, unique
111 devices - only a single one per product connected, or a real
112 USB serial number in the device - are always found with the same
113 name in the by-id/ directory.
114 Completely identical devices may overwrite their names in by-id/
115 and can only be found reliably in the by-path/ directory. Devices
116 specified by by-path/ must not change their connection, like the
117 USB port number they are plugged in, to keep their name.
119 To support some advanced features, Linux 2.6.22 is the oldest supported
120 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
121 supported. Older kernels should still work, and devices nodes should be
122 reliably created, but some rules and libudev will not work correctly because
123 the old kernels do not provide the expected information or interfaces.
129 Fix for a possible segfault while swapping network interface names in udev
136 The group "video" is part of the default rules now.
140 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
141 block devices in some cases. No common distro uses this option anymore,
142 and we do not get enough testing for this and recent udev versions. If
143 this option is not needed to run some old distro with a new kernel,
144 it should be disabled in the kernel config.
146 Bugfix for the $links substitution variable, which may crash if no links
147 are created. This should not happen in usual setups because we always
148 create /dev/{block,char}/ links.
150 The strings of the parsed rules, which are kept in memory, no longer
151 contain duplicate entries, or duplicate tails of strings. This, and the
152 new rules parsing/matching code reduces the total in-memory size of
153 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
156 The export of DEVTYPE=disk/partition got removed from the default
157 rules. This value is available from the kernel. The pnp shell script
158 modprobe hack is removed from the default rules. ACPI devices have _proper_
159 modalias support and take care of the same functionality.
160 Installations which support old kernels, but install current default
161 udev rules may want to add that to the compat rules file.
163 Libvolume_id now always probes for all known filesystems, and does not
164 stop at the first match. Some filesystems are marked as "exclusive probe",
165 and if any other filesytem type matches at the same time, libvolume_id
166 will, by default, not return any probing result. This is intended to prevent
167 mis-detection with conflicting left-over signatures found from earlier
168 file system formats. That way, we no longer depend on the probe-order
169 in case of multiple competing signatures. In some setups the kernel allows
170 to mount a volume with just the old filesystem signature still in place.
171 This may damage the new filesystem and cause data-loss, just by mounting
172 it. Because volume_id can not decide which one the correct signature is,
173 the wrong signatures need to be removed manually from the volume, or the
174 volume needs to be reformatted, to enable filesystem detection and possible
179 Fix segfault if compiled without optimization and dbg() does not get
180 compiled out and uses variables which are not available.
184 Bugfixes. (And maybe new bugs. :))
186 The rule matching engine got converted from a rule list to a token
187 array which reduced the in-memory rules representation of a full
188 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
189 Limits like 5 ENV and ATTR matches, and one single instance for most
190 other keys per rule are gone.
192 The NAME assignment is no longer special cased. If later rules assign
193 a NAME value again, the former value will be overwritten. As usual
194 for most other keys, the NAME value can be protected by doing a final
195 assignment with NAME:="<value>".
197 All udev code now uses libudev, which is also exported. The library
198 is still under development, marked as experimental, and its interface
199 may change as long as the DeviceKit integration is not finished.
201 Many thanks to Alan Jenkins for his continuous help, and finding and
202 optimizing some of the computing expensive parts.
208 Kernel devices and device nodes are connected now by reverse indizes in
209 /sys and /dev. A device number retrieved by a stat() or similar, the
210 kernel device directory can be found by looking up:
211 /sys/dev/{block,char}/<maj>:<min>
212 and the device node of the same device by looking up:
213 /dev/{block,char}/<maj>:<min>
217 Fix recently introduced bug, which caused a compilation without large
218 file support, where vol_id does not recognize raid signatures at the end
221 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
222 Seems some kernel versions prevent the creation of the ieee-* links,
223 so people used the scsi-* link which disappeared now.
225 More libudev work. Almost all udevadm functionality comes from libudev
228 udevadm trigger has a new option --type, which allows to trigger events
229 for "devices", for "subsystems", or "failed" devices. The old option
230 --retry-failed" still works, but is no longer mentioned in the man page.
236 The udevadm info --device-id-of-file= output has changed to use
237 the obvious format. Possible current users should use the --export
238 option which is not affected.
240 The old udev commands symlinks to udevadm are not installed, if
241 these symlinks are used, a warning is printed.
247 Optical drive's media is no longer probed for raid signatures,
248 reading the end of the device causes some devices to malfunction.
249 Also the offset of the last session found is used now to probe
252 The volume_id library got a major version number update to 1,
253 some deprecated functions are removed.
255 A shared library "libudev" gets installed now to provide access
256 to udev device information. DeviceKit, the successor of HAL, will
257 need this library to access the udev database and search sysfs for
259 The library is currently in an experimental state, also the API is
260 expected to change, as long as the DeviceKit integration is not
265 We use ./configure now. See INSTALL for details. Current
268 "/usr" - prefix for man pages, include files
270 "" - the root filesystem, prefix for libs and binaries
274 "lib" - directory name for libraries, not a path name
275 multilib 64bit systems may use "lib64" instead of "lib"
277 compile-in verbose debug messages
279 disable all logging and compile-out all log strings
281 link against SELInux libraries, to set the expected context
284 In the default rules, the group "disk" gets permissions 0660 instead
285 of 0640. One small step closer to unify distro rules. Some day, all
286 distros hopefully end up with the same set of rules.
288 No symlinks to udevadm are installed anymore, if they are still needed,
289 they should be provided by the package.
295 Default udev rules, which are not supposed to be edited by the user, should
296 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
297 the udev package and will be replaced with an update. Udev will pick up rule
299 /lib/udev/rules.d/ - default installed rules
300 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
301 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
302 It does not matter in which directory a rule file lives, all files are sorted
305 To help creating /dev/root, we have now:
306 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
309 In case the current --device-id-of-file is already used, please switch to
310 the --export format version, it saves the output parsing and the old
311 format will be changed to use ':' as a separator, like the format in the
316 Fix cdrom_id to properly recognize blank media.
322 Tape drive id-data is queried from /dev/bsg/* instead of the tape
323 nodes. This avoids rewinding tapes on open().
329 The symlinks udevcontrol and udevtrigger are no longer installed by
332 The scsi_id program does not depend on sysfs anymore. It can speak
333 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
334 data, which should solve some old problems with tape devices, where
335 we better do not open all tape device nodes to identify the device.
341 The cdrom_id program is replaced by an advanced version, which can
342 detect most common device types, and also properties of the inserted
343 media. This is part of moving some basic functionality from HAL into
344 udev (and the kernel).
350 The last WAIT_FOR_SYSFS rule is removed from the default rules.
352 The symlinks to udevadm for the debugging tools: udevmonitor and
353 udevtest are no longer created.
355 The symlinks to the udevadm man page for the old tool names are
358 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
359 should be prefixed with '@' to indicate that the path is not a
370 Udevstart is removed from the tree, it did not get installed for
371 a long time now, and is long replaced by trigger and settle.
377 All udev tools are merged into a single binary called udevadm.
378 The old names of the tools are built-in commands in udevadm now.
379 Symlinks to udevadm, with the names of the old tools, provide
380 the same functionality as the standalone tools. There is also
381 only a single udevadm.8 man page left for all tools.
383 Tools like mkinitramfs should be checked, if they need to include
384 udevadm in the list of files.
394 The etc/udev/rules.d/ directory now contains a default set of basic
395 udev rules. This initial version is the result of a rules file merge
396 of Fedora and openSUSE. For these both distros only a few specific
397 rules are left in their own file, named after the distro. Rules which
398 are optionally installed, because they are only valid for a specific
399 architecture, or rules for subsystems which are not always used are
400 in etc/udev/packages/.
406 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
407 actions by dynamically created rules.
409 SYMLINK=="<value>" matches agains the entries in the list of
410 currently defined symlinks. The links are not created in the
411 filesystem at that point in time, but the values can be matched.
413 RUN{ignore_error}+="<program>" will ignore any exit code from the
414 program and not record as a failed event.
420 Final merge of patches/features from the Ubuntu package.
426 Control characters in filesystem label strings are no longer silenty
427 removed, but hex-encoded, to be able to uniquely identify the device
428 by its symlink in /dev/disk/by-label/.
429 If libvolume_id is used by mount(8), LABEL= will work as expected,
430 if slashes or other characters are used in the label string.
432 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
433 can be specified now. The TEST key accepts an optional mode mask
434 TEST{0100}=="<is executable file>".
436 Scsi_id now supports a mode without expecting scsi-specific sysfs
437 entries to allow the extraction of cciss-device persistent properties.
443 In the future, we may see uuid's which are just simple character
444 strings (see the DDF Raid Specification). For that reason vol_id now
445 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
446 the creation of symlinks, the *_SAFE values ensure, that no control
447 or whitespace characters are used in the filename.
449 Possible users of libvolume_id, please use the volume_id_get_* functions.
450 The public struct will go away in a future release of the library.
456 Removal of useless extras/eventrecorder.sh.
466 The directory multiplexer for dev.d/ and hotplug.d are finally removed
467 from the udev package.
473 Symlinks can have priorities now, the priority is assigned to the device
474 and specified with OPTIONS="link_priority=100". Devices with higher
475 priorities overwrite the symlinks of devices with lower priorities.
476 If the device that currently owns the link, goes away, the symlink
477 will be removed, and recreated, pointing to the next device with the
478 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
479 more reliable, if multiple devices contain the same metadata and overwrite
482 The dasd_id program is removed from the udev tree, and dasdinfo, with the
483 needed rules, are part of the s390-tools now.
485 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
486 we may get the scsi sysfs mess fixed some day, and this will only catch
487 the devices we are looking for.
489 USB serial numbers for storage devices have the target:lun now appended,
490 to make it possibble to distinguish broken multi-lun devices with all
491 the same SCSI identifiers.
493 Note: The extra "run_directory" which searches and executes stuff in
494 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
495 with the next release. Make sure, that you don't use it anymore, or
496 provides your own implementation of that inefficient stuff.
497 We are tired of reports about a "slow udev", because these directories
498 contain stuff, that runs with _every_ event, instead of using rules,
499 that run programs only for the matching events.
509 DRIVER== will match only for devices that actually have a real
510 driver. DRIVERS== must be used, if parent devices should be
511 included in the match.
513 Libvolume_id's "linux_raid" detection needed another fix.
521 Add additional check to volume_id detection of via_raid, cause
522 some company decided to put a matching pattern all over the empty
523 storage area of their music players.
527 Fix path_id for SAS devices.
531 The udev daemon can be started with --debug-trace now, which will
532 execute all events serialized to get a chance to catch a possible
533 action that crashes the box.
535 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
536 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
537 are excluded from the warning. Referencing parent attributes directly
538 may break when something in the kernel driver model changes. Udev will
539 just find the attribute by walking up the parent chain.
541 Udevtrigger now sorts the list of devices depending on the device
542 dependency, so a "usb" device is triggered after the parent "pci"
547 Revert persistent-storage ata-serial '_' '-' replacement.
553 Udevtrigger can now filter the list of devices to be triggered. Matches
554 for subsystems or sysfs attributes can be specified.
556 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
557 zero-sized files to avoid pointing to /sys and confuse broken tools which
558 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
561 The rules and scripts to create udev rules for persistent network
562 devices and optical drives are in the extras/rules_generator directory
563 now. If you use something similar, please consider replacing your own
564 version with this, to share the support effort. The rule_generator
565 installs its own rules into /etc/udev/rules.d.
567 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
568 the rule_generator depends on cdrom_id to be called in an earlier rule.
574 Renaming of some key names (the old names still work):
575 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
576 (The behavior of the key DRIVER will change soon in one of the next
577 releases, to match only the event device, please switch to DRIVERS
578 instead. If DRIVER is used, it will behave like DRIVERS, but an error
580 With the new key names, we have a more consistent and simpler scheme.
581 We can match the properties of the event device only, with: KERNEL,
582 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
583 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
584 longer mentioned in the man page and should be switched in the rule
587 ATTR{file}="value" can be used now, to write to a sysfs file of the
588 event device. Instead of:
589 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
591 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
593 All the PHYSDEV* keys are deprecated and will be removed from a
595 PHYDEVPATH - is the path of a parent device and should not be
597 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
598 matched with SUBSYSTEMS==
599 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
600 Newer kernels will have DRIVER in the environment,
601 for older kernels udev puts in. Class device will
602 no longer carry this property of a parent and
603 DRIVERS== can be used to match such a parent value.
604 Note that ENV{DRIVER} is only available for a few bus devices, where
605 the driver is already bound at device event time. On coldplug, the
606 events for a lot devices are already bound to a driver, and they will have
607 that value set. But on hotplug, at the time the kernel creates the device,
608 it can't know what driver may claim the device after that, therefore
609 in most cases it will be empty.
611 Failed events should now be re-triggered with:
612 udevtrigger --retry-failed.
613 Please switch to this command, so we keep the details of the /dev/.udev/failed/
614 files private to the udev tools. We may need to switch the current symlink
615 target, cause some obviously broken tools try to scan all files in /dev
616 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
617 million times. This takes ages on slow boxes.
619 The udevinfo attribute walk (-a) now works with giving a device node
620 name (-n) instead of a devpath (-p). The query now always works, also when
621 no database file was created by udev.
623 The built-in /etc/passwd /etc/group parser is removed, we always depend on
624 getpwnam() and getgrnam() now. One of the next releases will depend on
625 fnmatch() and may use getopt_long().
629 Bugfixes and small improvements.
633 Fix path_id for recent kernels.
639 Added support for swapping network interface names, by temporarily
640 renaming the device and wait for the target name to become free.
644 The built-in MODALIAS key and substitution is removed.
648 The binary firmware helper is replaced by the usual simple
649 shell script. Udevsend is removed from the tree.
657 Some more keys require the correct use of '==' and '=' depending
658 on the kind of operation beeing an assignment or a match. Rules
659 with invalid operations are skipped and logged to syslog. Please
660 test with udevtest if the parsing of your rules throws errors and
661 fix possibly broken rules.
665 Provide "udevsettle" to wait for all current udev events to finish.
666 It also watches the current kernel netlink queue by comparing the
667 even sequence number to make sure that there are no current pending
668 events that have not already arrived in the daemon.
672 Fix rule to skip persistent rules for removable IDE devices, which
673 also skipped optical IDE drives.
675 All *_id program are installed in /lib/udev/ by default now.
677 No binary is stripped anymore as this should be done in the
678 packaging process and not at build time.
680 libvolume_id is provided as a shared library now and vol_id is
681 linked against it. Also one of the next HAL versions will require
682 this library, and the HAL build process will also require the
683 header file to be installed. The copy of the same code in HAL will
684 be removed to have only a single copy left on the system.
688 Add persistent links for SCSI tapes. The rules file is renamed
689 to 60-persistent-storage.rules.
691 Create persistent path for usb devices. Can be used for all sorts
692 of devices that can't be distinguished by other properties like
693 multiple identical keyboards and mice connected to the same box.
695 Provide "udevtrigger" program to request events on coldplug. The
696 shell script is much too slow with thousends of devices.
700 Fix persistent disk rules to exclude removable IDE drives.
702 Warn if %e, $modalias or MODALIAS is used.
706 Fix queue export, which wasn't correct for subsequent add/remove
707 events for the same device.
711 Fix cramfs detection on big endian.
713 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
718 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
719 attributes were only checked at the parent device that matched the
720 by BUS requested subsystem. Fix it to also look at the device we
721 received the event for.
723 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
728 Fix a bug where NAME="" would prevent RUN from beeing executed.
730 RUN="/bin/program" does not longer automatically add the subsystem
731 as the first parameter. This is from the days of /sbin/hotplug
732 which is dead now and it's just confusing to need to add a space at
733 the end of the program name to prevent this.
734 If you use rules that need the subsystem as the first parameter,
735 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
736 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
740 The udev man page has moved to udev(7) as it does not describe a command
741 anymore. The programs udev, udevstart and udevsend are no longer installed
742 by default and must be copied manually, if they should be installed or
743 included in a package.
745 Fix a bug where "ignore_device" could run earlier collected RUN keys before
746 the ignore rule was applied.
748 More preparation for future sysfs changes. usb_id and scsi_id no longer
749 depend on a magic order of devices in the /devices chain. Specific devices
750 should be requested by their subsytem.
752 This will always find the scsi parent device without depending on a specific
754 dev = sysfs_device_get(devpath);
755 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
757 The "device" link in the current sysfs layout will be automatically
758 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
759 parent in the devpath. If a device is requested by it's symlink, like all
760 class devices in the new sysfs layout will look like, it gets automatically
761 resolved and substituted with the real devpath and not the symlink path.
764 A similar logic must be applied to _all_ sysfs users, including
765 scripts, that search along parent devices in sysfs. The explicit use of
766 the "device" link must be avoided. With the future sysfs layout all
767 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
768 back to the "class" or the "bus". The layout of the parent devices in
769 /devices is not necessarily expected to be stable across kernel releases and
770 searching for parents by their subsystem should make sysfs users tolerant
771 for changed parent chains.
775 Prepare udev to work with the experimental kernel patch, that moves
776 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
778 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
779 moving the class devices to /sys/devices.
781 Thanks again to Marco for help finding a hopefully nice compromise
782 to make %b simpler and working again.
786 Complete removal of libsysfs, replaced by simple helper functions
787 which are much simpler and a bit faster. The udev daemon operatesentirely
788 on event parameters and does not use sysfs for simple rules anymore.
789 Please report any new bugs/problems, that may be caused by this big
790 change. They will be fixed immediately.
792 The enumeration format character '%e' is deprecated and will be
793 removed sometimes from a future udev version. It never worked correctly
794 outside of udevstart, so we can't use it with the new parallel
795 coldplug. A simple enumeration is as useless as the devfs naming
796 scheme, just get rid of both if you still use it.
798 MODALIAS and $modalias is not needed and will be removed from one of
799 the next udev versions, replace it in all rules with ENV{MODALIAS} or
800 the sysfs "modalias" value.
802 Thanks a lot to Marco for all his help on finding and fixing bugs.
806 Let scsi_id request libata drive serial numbers from page 0x80.
808 Renamed etc/udev/persistent.rules to persistent-disk.rules and
809 added /dev/disk/by-name/* for device mapper device names.
811 Removed %e from the man page. It never worked reliably outside
812 of udevstart and udevstart is no longer recommended to use.
816 Symlinks are now exported to the event environment. Hopefully it's no
817 longer needed to run udevinfo from an event process, like it was
818 mentioned on the hotplug list:
819 UDEV [1134776873.702967] add@/block/sdb
822 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
826 Fix a problem if udevsend is used as the hotplug handler and tries to use
827 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
828 and this kind of problems will hopefully go away soon.
832 All built-in logic to work around bad sysfs timing is removed with this
833 version. The need to wait for sysfs files is almost fixed with a kernel
834 version that doesn't work with this udev version anyway. Until we fix
835 the timing of the "bus" link creation, the former integrated logic should
836 be emulated by a rule placed before all other rules:
837 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
839 The option "udev_db" does no longer exist. All udev state will be in
840 /$udev_root/.udev/ now, there is no longer an option to set this
842 If the init script or something else used this value, just depend on
843 this hardcoded path. But remember _all_content_ of this directory is
844 still private to udev and can change at any time.
846 Default location for rule sripts and helper programs is now: /lib/udev/.
847 Everything that is not useful on the commandline should go into this
848 directory. Some of the helpers in the extras folder are installed there
849 now. The rules need to be changed, to find the helpers there.
851 Also /lib/udev/devices is recommended as a directory where packages or
852 the user can place real device nodes, which get copied over to /dev at
853 every boot. This should replace the various solutions with custom config
856 Udevsend does no longer start the udev daemon. This must be done with
857 the init script that prepares /dev on tmpfs and creates the initial nodes,
858 before starting the daemon.
862 Silent a too verbose error logging for the old hotplug.d/ dev.d/
865 The copy of klibc is removed. A systemwide installed version of klibc
866 should be used to build a klibc udev now.
870 NAME="" will not create any nodes, but execute RUN keys. To completely
871 ignore an event the OPTION "ignore_device" should be used.
873 After removal of the reorder queue, events with a TIMEOUT can be executed
874 without any queuing now.
878 Fixed bug in udevd, if inotify is not available. We depend on netlink
879 uevents now, kernels without that event source will not work with that
880 version of udev anymore.
884 The rule parsing happens now in the daemon once at startup, all udev
885 event processes inherit the already parsed rules from the daemon.
886 It is shipped with SUSE10.0 and reduces heavily the system load at
887 startup. The option to save precompiled rules and let the udev process
888 pick the them up is removed, as it's no longer needed.
890 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
891 device. Libsysfs is changed to "translate" the requested link into the
892 real device path, as it would happen with the hotplug event. Otherwise
893 device removal and the udev database will not work.
895 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
898 A few improvements for vol_id, the filesytem probing code.
902 Fix a stupid typo in extras/run_directory for "make install".
904 scsi_id creates the temporary devnode now in /dev for usage with a
905 non-writable /tmp directory.
907 The uevent kernel socket buffer can carry app. 50.000 events now,
908 let's see who can break this again. :)
910 The upcoming kernel will have a new input driver core integration.
911 Some class devices are now symlinks to the real device. libsysfs
912 needs a fix for this to work correctly. Udevstart of older udev
913 versions will _not_ create these devices!
917 Fix a 'install' target in the Makefile, that prevents EXTRAS from
922 A bunch of mostly trivial bugfixes. From now on no node name or
923 symlink name can contain any character than plain whitelisted ascii
924 characters or validated utf8 byte-streams. This is needed for the
925 /dev/disk/by-label/* links, because we import untrusted data and
926 export it to the filesystem.
930 More bugfixes. If udevd was started from the kernel, we don't
931 have stdin/stdout/stderr, which broke the forked tools in some
936 Bugfix. udevstart event ordering was broken for a long time.
937 The new run_program() uncovered it, because /dev/null was not
938 available while we try to run external programs.
939 Now udevstart should create it before we run anything.
943 Minor bugfixes and some distro rules updates. If you don't have the
944 persistent disk rules in /dev/disk/by-*/* on your distro, just
945 grab it from here. :)
949 We can use socket communication now to pass events from udev to
951 RUN+="socket:/org/freedesktop/hal/udev_event"
952 will pass the whole udev event to the HAL daemon without the need
953 for a forked helper. (See ChangeLog for udevmonitor, as an example)
957 Mostly bugfixes and see ChangeLog.
959 The test for the existence of an environment value should be
961 ENV{KEY}=="*" to ENV{KEY}=="?*"
962 because "*" will not fail anymore, if the key does not exist or
967 Bugfixes and a few tweaks described in the ChangeLog.
971 Mostly a Bugfix release.
973 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
974 timing with custom rules.
978 We changed the internal rule storage format. Our large rule files took
979 2 MB of RAM, with the change we are down to 99kB.
981 If the device-node has been created with default name and no symlink or
982 options are to remenber, it is not longer stored in the udevdb. HAL will
983 need to be updated to work correctly with that change.
985 To overrride optimization flags, OPTFLAGS may be used now.
993 Major changes happened with this release. The goal is to take over the
994 complete kernel-event handling and provide a more efficient way to dispatch
995 kernel events. Replacing most of the current shell script logic and the
996 kernel forked helper with a netlink-daemon and a rule-based event handling.
998 o udevd listens to netlink events now. The first valid netlink event
999 will make udevd ignore any message from udevsend that contains a
1000 SEQNUM, to avoid duplicate events. The forked events can be disabled
1002 echo "" > /proc/sys/kernel/hotplug
1003 For full support, the broken input-subsytem needs to be fixed, not to
1004 bypass the driver core.
1006 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1007 removed from udev itself and must be emulated by calling small
1008 helper binaries provided in the extras folder:
1009 make EXTRAS=extras/run_directory/
1010 will build udev_run_devd and udev_run_hotplugd, which can be called
1011 from a rule if needed:
1012 RUN+="/sbin/udev_run_hotplugd"
1013 The recommended way to handle this is to convert all the calls from
1014 the directories to explicit udev rules and get completely rid of the
1015 multiplexing. (To catch a ttyUSB event, you now no longer need to
1016 fork and exit 300 tty script instances you are not interested in, it
1017 is just one rule that matches exactly the device.)
1019 o udev handles now _all_ events not just events for class and block
1020 devices, this way it is possible to control the complete event
1021 behavior with udev rules. Especially useful for rules like:
1022 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1024 o As used in the modalias rule, udev supports now textual
1025 substitution placeholder along with the usual format chars. This
1026 needs to be documented, for now it's only visible in udev_rules_parse.c.
1028 o The rule keys support now more operations. This is documented in the
1029 man page. It is possible to add values to list-keys like the SYMLINK
1030 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1031 Also "final"-assignments are supported by using KEY:="value", which will
1032 prevent changing the key by any later rule.
1034 o kernel 2.6.12 has the "detached_state" attribute removed from
1035 sysfs, which was used to recognize sysfs population. We switched that
1036 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1037 Running this udev version on older kernels may cause a short delay for
1040 o To provide infrastructure for persistent device naming, the id programs:
1041 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1042 to export the probed data in environment key format:
1043 pim:~ # /sbin/ata_id --export /dev/hda
1044 ID_MODEL=HTS726060M9AT00
1045 ID_SERIAL=MRH401M4G6UM9B
1046 ID_REVISION=MH4OA6BA
1048 The following rules:
1049 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1050 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1053 kay@pim:~> tree /dev/disk
1056 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1057 | `-- IBM-Memory_Key -> ../../sda
1059 | |-- swap -> ../../hda1
1060 | |-- date -> ../../sda1
1061 | `-- home -> ../../hda3
1063 |-- 2E08712B0870F2E7 -> ../../hda3
1064 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1065 |-- E845-7A89 -> ../../sda1
1066 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1068 The IMPORT= operation will import these keys in the environment and make
1069 it available for later PROGRAM= and RUN= executed programs. The keys are
1070 also stored in the udevdb and can be queried from there with one of the
1073 o A few binaries are silently added to the repository, which can be used
1074 to replay kernel events from initramfs instead of using coldplug. udevd
1075 can be instructed now to queue-up events while the stored events from
1076 initramfs are filled into the udevd-queue. This code is still under
1077 development and there is no documentation now besides the code itself.
1078 The additional binaries get compiled, but are not installed by default.
1080 o There is also a temporary fix for a performance problem where too many
1081 events happen in parallel and every event needs to parse the rules.
1082 udev can now read precompiled rules stored on disk. This is likely to be
1083 replaced by a more elegant solution in a future udev version.
1087 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1088 Fix for libsysfs not to expect this file was added.
1092 All rules are applied now, but only the first matching rule with a NAME-key
1093 will be applied. All later rules with NAME-key are completely ignored. This
1094 way system supplied symlinks or permissions gets applied to user-defined
1098 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1099 to some rules, to keep the old behavior.
1101 The rules are read on "remove"-events too. That makes is possible to match
1102 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1103 instruct udev to ignore an event (OPTIONS="ignore_device").
1104 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1106 The new RUN-key supports rule-based execution of programs after device-node
1107 handling. This is meant as a general replacement for the dev.d/-directories
1108 to give fine grained control over the execution of programs.
1110 The %s{}-sysfs format char replacement values are searched at any of the
1111 devices in the device chain now, not only at the class-device.
1113 We support log priority levels now. The value udev_log in udev.conf is used
1114 to determine what is printed to syslog. This makes it possible to
1115 run a version with compiled-in debug messages in a production environment
1116 which is sometimes needed to find a bug.
1117 It is still possible to supress the inclusion of _any_ syslog usage with
1118 USE_LOG=false to create the smallest possible binaries if needed.
1119 The configured udev_log value can be overridden with the environment variable
1124 Possible use of a system-wide klibc:
1125 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1126 will link against an external klibc and our own version will be ignored.
1130 We support an unlimited count of symlinks now.
1132 If USE_STATIC=true is passed to a glibc build, we link statically and use
1133 a built-in userdb parser to resolve user and group names.
1135 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1136 we walk up the chain of physical devices to find a match.
1138 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1139 easy to skip certain attribute matches without composing rules with weird
1140 character class negations like:
1141 KERNEL="[!s][!c][!d]*"
1142 this can now be replaced with:
1144 The current simple '=' is still supported, and should work as it does today,
1145 but existing rules should be converted if possible, to be better readable.
1147 We have new ENV{}== key now, to match against a maximum of 5 environment
1150 udevstart is its own binary again, because we don't need co carry this araound
1151 with every forked event.
~ianmdlvl / elogind.git / blob