5 The program vol_id and the library libvolume_id are removed from the
6 repository. Libvolume_id is merged with libblkid from the util-linux-ng
7 package. Persistent disk links for label and uuid depend on the
8 util-linux-ng version (2.15) of blkid now. Older versions of blkid
9 can not be used with udev.
11 Libudev allows to subscribe to udev events. To prevent unwanted messages
12 to be delivered, and waking up the subscribing process, a filter can be
13 installed, to drop messages inside a kernel socket filter. The filters
14 match on the <subsytem>:<devtype> properties of the device.
15 This is part of the ongoing effort to replace HAL, and switch current
16 users over to directly use libudev.
17 Libudev is still marked as experimental, and its interface might
18 eventually change if needed, but no major changes of the currently exported
19 interface are expected anymore, and a first stable release should happen
22 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
23 is not supported since while and udevd will log an error message at
24 startup. It should still be able to boot-up, but advanced rules and system
25 services which depend on the information not available in the old sysfs
26 format will fail to work correctly.
28 DVB device naming is supplied by the kernel now. In case older kernels
29 need to be supported, the old shell script should be added to a compat
36 The processed udev events get send back to the netlink socket. Libudev
37 provides access to these events. This is work-in-progress, to replace
38 the DeviceKit daemon functionality directly with libudev. There are
39 upcoming kernel changes to allow non-root users to subcribe to these
46 "udevadm settle" now optionally accepts a range of events to wait for,
47 instead of waiting for "all" events.
53 The installed watch for block device metadata changes is now removed
54 during event hadling, because some (broken) tools may be called from udev
55 rules and (wrongly) open the device with write access. After the finished
56 event handling the watch is restored.
62 Device nodes can be watched for changes with inotify with OPTIONS="watch".
63 If closed after being opened for writing, a "change" uevent will occur.
64 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
70 The udevadm test command has no longer a --force option, nodes and symlinks
71 are always updated with a test run now.
73 The udevd daemon can be started with --resolve-names=never to avoid all user
74 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
75 lookup user and groups every time events are handled.
81 We are currently merging the Ubuntu rules in the udev default rules,
82 and get one step closer to provide a common Linux /dev setup, regarding
83 device names, symlinks, and default device permissions. On udev startup,
84 we now expect the following groups to be resolvable to their ids with
86 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
87 LDAP setups need to make sure, that these groups are always resolvable at
88 bootup, with only the rootfs mounted, and without network access available.
90 Some systems may need to add some new, currently not used groups, or need
91 to add some users to new groups, but the cost of this change is minimal,
92 compared to the pain the current, rather random, differences between the
93 various distributions cause for upstream projects and third-party vendors.
95 In general, "normal" users who log into a machine should never be a member
96 of any such group, but the device-access should be managed by dynamic ACLs,
97 which get added and removed for the specific users on login/logout and
98 session activity/inactivity. These groups are only provided for custom setups,
99 and mainly system services, to allow proper privilege separation.
100 A video-streaming daemon uid would be a member of "audio" and "video", to get
101 access to the sound and video devices, but no "normal" user should ever belong
102 to the "audio" group, because he could listen to the built-in microphone with
103 any ssh-session established from the other side of the world.
105 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
106 which do not depend on the kernel device name. As usual, unique
107 devices - only a single one per product connected, or a real
108 USB serial number in the device - are always found with the same
109 name in the by-id/ directory.
110 Completely identical devices may overwrite their names in by-id/
111 and can only be found reliably in the by-path/ directory. Devices
112 specified by by-path/ must not change their connection, like the
113 USB port number they are plugged in, to keep their name.
115 To support some advanced features, Linux 2.6.22 is the oldest supported
116 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
117 supported. Older kernels should still work, and devices nodes should be
118 reliably created, but some rules and libudev will not work correctly because
119 the old kernels do not provide the expected information or interfaces.
125 Fix for a possible segfault while swapping network interface names in udev
132 The group "video" is part of the default rules now.
136 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
137 block devices in some cases. No common distro uses this option anymore,
138 and we do not get enough testing for this and recent udev versions. If
139 this option is not needed to run some old distro with a new kernel,
140 it should be disabled in the kernel config.
142 Bugfix for the $links substitution variable, which may crash if no links
143 are created. This should not happen in usual setups because we always
144 create /dev/{block,char}/ links.
146 The strings of the parsed rules, which are kept in memory, no longer
147 contain duplicate entries, or duplicate tails of strings. This, and the
148 new rules parsing/matching code reduces the total in-memory size of
149 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
152 The export of DEVTYPE=disk/partition got removed from the default
153 rules. This value is available from the kernel. The pnp shell script
154 modprobe hack is removed from the default rules. ACPI devices have _proper_
155 modalias support and take care of the same functionality.
156 Installations which support old kernels, but install current default
157 udev rules may want to add that to the compat rules file.
159 Libvolume_id now always probes for all known filesystems, and does not
160 stop at the first match. Some filesystems are marked as "exclusive probe",
161 and if any other filesytem type matches at the same time, libvolume_id
162 will, by default, not return any probing result. This is intended to prevent
163 mis-detection with conflicting left-over signatures found from earlier
164 file system formats. That way, we no longer depend on the probe-order
165 in case of multiple competing signatures. In some setups the kernel allows
166 to mount a volume with just the old filesystem signature still in place.
167 This may damage the new filesystem and cause data-loss, just by mounting
168 it. Because volume_id can not decide which one the correct signature is,
169 the wrong signatures need to be removed manually from the volume, or the
170 volume needs to be reformatted, to enable filesystem detection and possible
175 Fix segfault if compiled without optimization and dbg() does not get
176 compiled out and uses variables which are not available.
180 Bugfixes. (And maybe new bugs. :))
182 The rule matching engine got converted from a rule list to a token
183 array which reduced the in-memory rules representation of a full
184 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
185 Limits like 5 ENV and ATTR matches, and one single instance for most
186 other keys per rule are gone.
188 The NAME assignment is no longer special cased. If later rules assign
189 a NAME value again, the former value will be overwritten. As usual
190 for most other keys, the NAME value can be protected by doing a final
191 assignment with NAME:="<value>".
193 All udev code now uses libudev, which is also exported. The library
194 is still under development, marked as experimental, and its interface
195 may change as long as the DeviceKit integration is not finished.
197 Many thanks to Alan Jenkins for his continuous help, and finding and
198 optimizing some of the computing expensive parts.
204 Kernel devices and device nodes are connected now by reverse indizes in
205 /sys and /dev. A device number retrieved by a stat() or similar, the
206 kernel device directory can be found by looking up:
207 /sys/dev/{block,char}/<maj>:<min>
208 and the device node of the same device by looking up:
209 /dev/{block,char}/<maj>:<min>
213 Fix recently introduced bug, which caused a compilation without large
214 file support, where vol_id does not recognize raid signatures at the end
217 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
218 Seems some kernel versions prevent the creation of the ieee-* links,
219 so people used the scsi-* link which disappeared now.
221 More libudev work. Almost all udevadm functionality comes from libudev
224 udevadm trigger has a new option --type, which allows to trigger events
225 for "devices", for "subsystems", or "failed" devices. The old option
226 --retry-failed" still works, but is no longer mentioned in the man page.
232 The udevadm info --device-id-of-file= output has changed to use
233 the obvious format. Possible current users should use the --export
234 option which is not affected.
236 The old udev commands symlinks to udevadm are not installed, if
237 these symlinks are used, a warning is printed.
243 Optical drive's media is no longer probed for raid signatures,
244 reading the end of the device causes some devices to malfunction.
245 Also the offset of the last session found is used now to probe
248 The volume_id library got a major version number update to 1,
249 some deprecated functions are removed.
251 A shared library "libudev" gets installed now to provide access
252 to udev device information. DeviceKit, the successor of HAL, will
253 need this library to access the udev database and search sysfs for
255 The library is currently in an experimental state, also the API is
256 expected to change, as long as the DeviceKit integration is not
261 We use ./configure now. See INSTALL for details. Current
264 "/usr" - prefix for man pages, include files
266 "" - the root filesystem, prefix for libs and binaries
270 "lib" - directory name for libraries, not a path name
271 multilib 64bit systems may use "lib64" instead of "lib"
273 compile-in verbose debug messages
275 disable all logging and compile-out all log strings
277 link against SELInux libraries, to set the expected context
280 In the default rules, the group "disk" gets permissions 0660 instead
281 of 0640. One small step closer to unify distro rules. Some day, all
282 distros hopefully end up with the same set of rules.
284 No symlinks to udevadm are installed anymore, if they are still needed,
285 they should be provided by the package.
291 Default udev rules, which are not supposed to be edited by the user, should
292 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
293 the udev package and will be replaced with an update. Udev will pick up rule
295 /lib/udev/rules.d/ - default installed rules
296 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
297 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
298 It does not matter in which directory a rule file lives, all files are sorted
301 To help creating /dev/root, we have now:
302 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
305 In case the current --device-id-of-file is already used, please switch to
306 the --export format version, it saves the output parsing and the old
307 format will be changed to use ':' as a separator, like the format in the
312 Fix cdrom_id to properly recognize blank media.
318 Tape drive id-data is queried from /dev/bsg/* instead of the tape
319 nodes. This avoids rewinding tapes on open().
325 The symlinks udevcontrol and udevtrigger are no longer installed by
328 The scsi_id program does not depend on sysfs anymore. It can speak
329 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
330 data, which should solve some old problems with tape devices, where
331 we better do not open all tape device nodes to identify the device.
337 The cdrom_id program is replaced by an advanced version, which can
338 detect most common device types, and also properties of the inserted
339 media. This is part of moving some basic functionality from HAL into
340 udev (and the kernel).
346 The last WAIT_FOR_SYSFS rule is removed from the default rules.
348 The symlinks to udevadm for the debugging tools: udevmonitor and
349 udevtest are no longer created.
351 The symlinks to the udevadm man page for the old tool names are
354 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
355 should be prefixed with '@' to indicate that the path is not a
366 Udevstart is removed from the tree, it did not get installed for
367 a long time now, and is long replaced by trigger and settle.
373 All udev tools are merged into a single binary called udevadm.
374 The old names of the tools are built-in commands in udevadm now.
375 Symlinks to udevadm, with the names of the old tools, provide
376 the same functionality as the standalone tools. There is also
377 only a single udevadm.8 man page left for all tools.
379 Tools like mkinitramfs should be checked, if they need to include
380 udevadm in the list of files.
390 The etc/udev/rules.d/ directory now contains a default set of basic
391 udev rules. This initial version is the result of a rules file merge
392 of Fedora and openSUSE. For these both distros only a few specific
393 rules are left in their own file, named after the distro. Rules which
394 are optionally installed, because they are only valid for a specific
395 architecture, or rules for subsystems which are not always used are
396 in etc/udev/packages/.
402 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
403 actions by dynamically created rules.
405 SYMLINK=="<value>" matches agains the entries in the list of
406 currently defined symlinks. The links are not created in the
407 filesystem at that point in time, but the values can be matched.
409 RUN{ignore_error}+="<program>" will ignore any exit code from the
410 program and not record as a failed event.
416 Final merge of patches/features from the Ubuntu package.
422 Control characters in filesystem label strings are no longer silenty
423 removed, but hex-encoded, to be able to uniquely identify the device
424 by its symlink in /dev/disk/by-label/.
425 If libvolume_id is used by mount(8), LABEL= will work as expected,
426 if slashes or other characters are used in the label string.
428 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
429 can be specified now. The TEST key accepts an optional mode mask
430 TEST{0100}=="<is executable file>".
432 Scsi_id now supports a mode without expecting scsi-specific sysfs
433 entries to allow the extraction of cciss-device persistent properties.
439 In the future, we may see uuid's which are just simple character
440 strings (see the DDF Raid Specification). For that reason vol_id now
441 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
442 the creation of symlinks, the *_SAFE values ensure, that no control
443 or whitespace characters are used in the filename.
445 Possible users of libvolume_id, please use the volume_id_get_* functions.
446 The public struct will go away in a future release of the library.
452 Removal of useless extras/eventrecorder.sh.
462 The directory multiplexer for dev.d/ and hotplug.d are finally removed
463 from the udev package.
469 Symlinks can have priorities now, the priority is assigned to the device
470 and specified with OPTIONS="link_priority=100". Devices with higher
471 priorities overwrite the symlinks of devices with lower priorities.
472 If the device that currently owns the link, goes away, the symlink
473 will be removed, and recreated, pointing to the next device with the
474 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
475 more reliable, if multiple devices contain the same metadata and overwrite
478 The dasd_id program is removed from the udev tree, and dasdinfo, with the
479 needed rules, are part of the s390-tools now.
481 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
482 we may get the scsi sysfs mess fixed some day, and this will only catch
483 the devices we are looking for.
485 USB serial numbers for storage devices have the target:lun now appended,
486 to make it possibble to distinguish broken multi-lun devices with all
487 the same SCSI identifiers.
489 Note: The extra "run_directory" which searches and executes stuff in
490 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
491 with the next release. Make sure, that you don't use it anymore, or
492 provides your own implementation of that inefficient stuff.
493 We are tired of reports about a "slow udev", because these directories
494 contain stuff, that runs with _every_ event, instead of using rules,
495 that run programs only for the matching events.
505 DRIVER== will match only for devices that actually have a real
506 driver. DRIVERS== must be used, if parent devices should be
507 included in the match.
509 Libvolume_id's "linux_raid" detection needed another fix.
517 Add additional check to volume_id detection of via_raid, cause
518 some company decided to put a matching pattern all over the empty
519 storage area of their music players.
523 Fix path_id for SAS devices.
527 The udev daemon can be started with --debug-trace now, which will
528 execute all events serialized to get a chance to catch a possible
529 action that crashes the box.
531 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
532 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
533 are excluded from the warning. Referencing parent attributes directly
534 may break when something in the kernel driver model changes. Udev will
535 just find the attribute by walking up the parent chain.
537 Udevtrigger now sorts the list of devices depending on the device
538 dependency, so a "usb" device is triggered after the parent "pci"
543 Revert persistent-storage ata-serial '_' '-' replacement.
549 Udevtrigger can now filter the list of devices to be triggered. Matches
550 for subsystems or sysfs attributes can be specified.
552 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
553 zero-sized files to avoid pointing to /sys and confuse broken tools which
554 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
557 The rules and scripts to create udev rules for persistent network
558 devices and optical drives are in the extras/rules_generator directory
559 now. If you use something similar, please consider replacing your own
560 version with this, to share the support effort. The rule_generator
561 installs its own rules into /etc/udev/rules.d.
563 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
564 the rule_generator depends on cdrom_id to be called in an earlier rule.
570 Renaming of some key names (the old names still work):
571 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
572 (The behavior of the key DRIVER will change soon in one of the next
573 releases, to match only the event device, please switch to DRIVERS
574 instead. If DRIVER is used, it will behave like DRIVERS, but an error
576 With the new key names, we have a more consistent and simpler scheme.
577 We can match the properties of the event device only, with: KERNEL,
578 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
579 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
580 longer mentioned in the man page and should be switched in the rule
583 ATTR{file}="value" can be used now, to write to a sysfs file of the
584 event device. Instead of:
585 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
587 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
589 All the PHYSDEV* keys are deprecated and will be removed from a
591 PHYDEVPATH - is the path of a parent device and should not be
593 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
594 matched with SUBSYSTEMS==
595 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
596 Newer kernels will have DRIVER in the environment,
597 for older kernels udev puts in. Class device will
598 no longer carry this property of a parent and
599 DRIVERS== can be used to match such a parent value.
600 Note that ENV{DRIVER} is only available for a few bus devices, where
601 the driver is already bound at device event time. On coldplug, the
602 events for a lot devices are already bound to a driver, and they will have
603 that value set. But on hotplug, at the time the kernel creates the device,
604 it can't know what driver may claim the device after that, therefore
605 in most cases it will be empty.
607 Failed events should now be re-triggered with:
608 udevtrigger --retry-failed.
609 Please switch to this command, so we keep the details of the /dev/.udev/failed/
610 files private to the udev tools. We may need to switch the current symlink
611 target, cause some obviously broken tools try to scan all files in /dev
612 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
613 million times. This takes ages on slow boxes.
615 The udevinfo attribute walk (-a) now works with giving a device node
616 name (-n) instead of a devpath (-p). The query now always works, also when
617 no database file was created by udev.
619 The built-in /etc/passwd /etc/group parser is removed, we always depend on
620 getpwnam() and getgrnam() now. One of the next releases will depend on
621 fnmatch() and may use getopt_long().
625 Bugfixes and small improvements.
629 Fix path_id for recent kernels.
635 Added support for swapping network interface names, by temporarily
636 renaming the device and wait for the target name to become free.
640 The built-in MODALIAS key and substitution is removed.
644 The binary firmware helper is replaced by the usual simple
645 shell script. Udevsend is removed from the tree.
653 Some more keys require the correct use of '==' and '=' depending
654 on the kind of operation beeing an assignment or a match. Rules
655 with invalid operations are skipped and logged to syslog. Please
656 test with udevtest if the parsing of your rules throws errors and
657 fix possibly broken rules.
661 Provide "udevsettle" to wait for all current udev events to finish.
662 It also watches the current kernel netlink queue by comparing the
663 even sequence number to make sure that there are no current pending
664 events that have not already arrived in the daemon.
668 Fix rule to skip persistent rules for removable IDE devices, which
669 also skipped optical IDE drives.
671 All *_id program are installed in /lib/udev/ by default now.
673 No binary is stripped anymore as this should be done in the
674 packaging process and not at build time.
676 libvolume_id is provided as a shared library now and vol_id is
677 linked against it. Also one of the next HAL versions will require
678 this library, and the HAL build process will also require the
679 header file to be installed. The copy of the same code in HAL will
680 be removed to have only a single copy left on the system.
684 Add persistent links for SCSI tapes. The rules file is renamed
685 to 60-persistent-storage.rules.
687 Create persistent path for usb devices. Can be used for all sorts
688 of devices that can't be distinguished by other properties like
689 multiple identical keyboards and mice connected to the same box.
691 Provide "udevtrigger" program to request events on coldplug. The
692 shell script is much too slow with thousends of devices.
696 Fix persistent disk rules to exclude removable IDE drives.
698 Warn if %e, $modalias or MODALIAS is used.
702 Fix queue export, which wasn't correct for subsequent add/remove
703 events for the same device.
707 Fix cramfs detection on big endian.
709 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
714 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
715 attributes were only checked at the parent device that matched the
716 by BUS requested subsystem. Fix it to also look at the device we
717 received the event for.
719 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
724 Fix a bug where NAME="" would prevent RUN from beeing executed.
726 RUN="/bin/program" does not longer automatically add the subsystem
727 as the first parameter. This is from the days of /sbin/hotplug
728 which is dead now and it's just confusing to need to add a space at
729 the end of the program name to prevent this.
730 If you use rules that need the subsystem as the first parameter,
731 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
732 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
736 The udev man page has moved to udev(7) as it does not describe a command
737 anymore. The programs udev, udevstart and udevsend are no longer installed
738 by default and must be copied manually, if they should be installed or
739 included in a package.
741 Fix a bug where "ignore_device" could run earlier collected RUN keys before
742 the ignore rule was applied.
744 More preparation for future sysfs changes. usb_id and scsi_id no longer
745 depend on a magic order of devices in the /devices chain. Specific devices
746 should be requested by their subsytem.
748 This will always find the scsi parent device without depending on a specific
750 dev = sysfs_device_get(devpath);
751 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
753 The "device" link in the current sysfs layout will be automatically
754 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
755 parent in the devpath. If a device is requested by it's symlink, like all
756 class devices in the new sysfs layout will look like, it gets automatically
757 resolved and substituted with the real devpath and not the symlink path.
760 A similar logic must be applied to _all_ sysfs users, including
761 scripts, that search along parent devices in sysfs. The explicit use of
762 the "device" link must be avoided. With the future sysfs layout all
763 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
764 back to the "class" or the "bus". The layout of the parent devices in
765 /devices is not necessarily expected to be stable across kernel releases and
766 searching for parents by their subsystem should make sysfs users tolerant
767 for changed parent chains.
771 Prepare udev to work with the experimental kernel patch, that moves
772 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
774 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
775 moving the class devices to /sys/devices.
777 Thanks again to Marco for help finding a hopefully nice compromise
778 to make %b simpler and working again.
782 Complete removal of libsysfs, replaced by simple helper functions
783 which are much simpler and a bit faster. The udev daemon operatesentirely
784 on event parameters and does not use sysfs for simple rules anymore.
785 Please report any new bugs/problems, that may be caused by this big
786 change. They will be fixed immediately.
788 The enumeration format character '%e' is deprecated and will be
789 removed sometimes from a future udev version. It never worked correctly
790 outside of udevstart, so we can't use it with the new parallel
791 coldplug. A simple enumeration is as useless as the devfs naming
792 scheme, just get rid of both if you still use it.
794 MODALIAS and $modalias is not needed and will be removed from one of
795 the next udev versions, replace it in all rules with ENV{MODALIAS} or
796 the sysfs "modalias" value.
798 Thanks a lot to Marco for all his help on finding and fixing bugs.
802 Let scsi_id request libata drive serial numbers from page 0x80.
804 Renamed etc/udev/persistent.rules to persistent-disk.rules and
805 added /dev/disk/by-name/* for device mapper device names.
807 Removed %e from the man page. It never worked reliably outside
808 of udevstart and udevstart is no longer recommended to use.
812 Symlinks are now exported to the event environment. Hopefully it's no
813 longer needed to run udevinfo from an event process, like it was
814 mentioned on the hotplug list:
815 UDEV [1134776873.702967] add@/block/sdb
818 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
822 Fix a problem if udevsend is used as the hotplug handler and tries to use
823 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
824 and this kind of problems will hopefully go away soon.
828 All built-in logic to work around bad sysfs timing is removed with this
829 version. The need to wait for sysfs files is almost fixed with a kernel
830 version that doesn't work with this udev version anyway. Until we fix
831 the timing of the "bus" link creation, the former integrated logic should
832 be emulated by a rule placed before all other rules:
833 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
835 The option "udev_db" does no longer exist. All udev state will be in
836 /$udev_root/.udev/ now, there is no longer an option to set this
838 If the init script or something else used this value, just depend on
839 this hardcoded path. But remember _all_content_ of this directory is
840 still private to udev and can change at any time.
842 Default location for rule sripts and helper programs is now: /lib/udev/.
843 Everything that is not useful on the commandline should go into this
844 directory. Some of the helpers in the extras folder are installed there
845 now. The rules need to be changed, to find the helpers there.
847 Also /lib/udev/devices is recommended as a directory where packages or
848 the user can place real device nodes, which get copied over to /dev at
849 every boot. This should replace the various solutions with custom config
852 Udevsend does no longer start the udev daemon. This must be done with
853 the init script that prepares /dev on tmpfs and creates the initial nodes,
854 before starting the daemon.
858 Silent a too verbose error logging for the old hotplug.d/ dev.d/
861 The copy of klibc is removed. A systemwide installed version of klibc
862 should be used to build a klibc udev now.
866 NAME="" will not create any nodes, but execute RUN keys. To completely
867 ignore an event the OPTION "ignore_device" should be used.
869 After removal of the reorder queue, events with a TIMEOUT can be executed
870 without any queuing now.
874 Fixed bug in udevd, if inotify is not available. We depend on netlink
875 uevents now, kernels without that event source will not work with that
876 version of udev anymore.
880 The rule parsing happens now in the daemon once at startup, all udev
881 event processes inherit the already parsed rules from the daemon.
882 It is shipped with SUSE10.0 and reduces heavily the system load at
883 startup. The option to save precompiled rules and let the udev process
884 pick the them up is removed, as it's no longer needed.
886 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
887 device. Libsysfs is changed to "translate" the requested link into the
888 real device path, as it would happen with the hotplug event. Otherwise
889 device removal and the udev database will not work.
891 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
894 A few improvements for vol_id, the filesytem probing code.
898 Fix a stupid typo in extras/run_directory for "make install".
900 scsi_id creates the temporary devnode now in /dev for usage with a
901 non-writable /tmp directory.
903 The uevent kernel socket buffer can carry app. 50.000 events now,
904 let's see who can break this again. :)
906 The upcoming kernel will have a new input driver core integration.
907 Some class devices are now symlinks to the real device. libsysfs
908 needs a fix for this to work correctly. Udevstart of older udev
909 versions will _not_ create these devices!
913 Fix a 'install' target in the Makefile, that prevents EXTRAS from
918 A bunch of mostly trivial bugfixes. From now on no node name or
919 symlink name can contain any character than plain whitelisted ascii
920 characters or validated utf8 byte-streams. This is needed for the
921 /dev/disk/by-label/* links, because we import untrusted data and
922 export it to the filesystem.
926 More bugfixes. If udevd was started from the kernel, we don't
927 have stdin/stdout/stderr, which broke the forked tools in some
932 Bugfix. udevstart event ordering was broken for a long time.
933 The new run_program() uncovered it, because /dev/null was not
934 available while we try to run external programs.
935 Now udevstart should create it before we run anything.
939 Minor bugfixes and some distro rules updates. If you don't have the
940 persistent disk rules in /dev/disk/by-*/* on your distro, just
941 grab it from here. :)
945 We can use socket communication now to pass events from udev to
947 RUN+="socket:/org/freedesktop/hal/udev_event"
948 will pass the whole udev event to the HAL daemon without the need
949 for a forked helper. (See ChangeLog for udevmonitor, as an example)
953 Mostly bugfixes and see ChangeLog.
955 The test for the existence of an environment value should be
957 ENV{KEY}=="*" to ENV{KEY}=="?*"
958 because "*" will not fail anymore, if the key does not exist or
963 Bugfixes and a few tweaks described in the ChangeLog.
967 Mostly a Bugfix release.
969 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
970 timing with custom rules.
974 We changed the internal rule storage format. Our large rule files took
975 2 MB of RAM, with the change we are down to 99kB.
977 If the device-node has been created with default name and no symlink or
978 options are to remenber, it is not longer stored in the udevdb. HAL will
979 need to be updated to work correctly with that change.
981 To overrride optimization flags, OPTFLAGS may be used now.
989 Major changes happened with this release. The goal is to take over the
990 complete kernel-event handling and provide a more efficient way to dispatch
991 kernel events. Replacing most of the current shell script logic and the
992 kernel forked helper with a netlink-daemon and a rule-based event handling.
994 o udevd listens to netlink events now. The first valid netlink event
995 will make udevd ignore any message from udevsend that contains a
996 SEQNUM, to avoid duplicate events. The forked events can be disabled
998 echo "" > /proc/sys/kernel/hotplug
999 For full support, the broken input-subsytem needs to be fixed, not to
1000 bypass the driver core.
1002 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1003 removed from udev itself and must be emulated by calling small
1004 helper binaries provided in the extras folder:
1005 make EXTRAS=extras/run_directory/
1006 will build udev_run_devd and udev_run_hotplugd, which can be called
1007 from a rule if needed:
1008 RUN+="/sbin/udev_run_hotplugd"
1009 The recommended way to handle this is to convert all the calls from
1010 the directories to explicit udev rules and get completely rid of the
1011 multiplexing. (To catch a ttyUSB event, you now no longer need to
1012 fork and exit 300 tty script instances you are not interested in, it
1013 is just one rule that matches exactly the device.)
1015 o udev handles now _all_ events not just events for class and block
1016 devices, this way it is possible to control the complete event
1017 behavior with udev rules. Especially useful for rules like:
1018 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1020 o As used in the modalias rule, udev supports now textual
1021 substitution placeholder along with the usual format chars. This
1022 needs to be documented, for now it's only visible in udev_rules_parse.c.
1024 o The rule keys support now more operations. This is documented in the
1025 man page. It is possible to add values to list-keys like the SYMLINK
1026 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1027 Also "final"-assignments are supported by using KEY:="value", which will
1028 prevent changing the key by any later rule.
1030 o kernel 2.6.12 has the "detached_state" attribute removed from
1031 sysfs, which was used to recognize sysfs population. We switched that
1032 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1033 Running this udev version on older kernels may cause a short delay for
1036 o To provide infrastructure for persistent device naming, the id programs:
1037 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1038 to export the probed data in environment key format:
1039 pim:~ # /sbin/ata_id --export /dev/hda
1040 ID_MODEL=HTS726060M9AT00
1041 ID_SERIAL=MRH401M4G6UM9B
1042 ID_REVISION=MH4OA6BA
1044 The following rules:
1045 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1046 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1049 kay@pim:~> tree /dev/disk
1052 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1053 | `-- IBM-Memory_Key -> ../../sda
1055 | |-- swap -> ../../hda1
1056 | |-- date -> ../../sda1
1057 | `-- home -> ../../hda3
1059 |-- 2E08712B0870F2E7 -> ../../hda3
1060 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1061 |-- E845-7A89 -> ../../sda1
1062 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1064 The IMPORT= operation will import these keys in the environment and make
1065 it available for later PROGRAM= and RUN= executed programs. The keys are
1066 also stored in the udevdb and can be queried from there with one of the
1069 o A few binaries are silently added to the repository, which can be used
1070 to replay kernel events from initramfs instead of using coldplug. udevd
1071 can be instructed now to queue-up events while the stored events from
1072 initramfs are filled into the udevd-queue. This code is still under
1073 development and there is no documentation now besides the code itself.
1074 The additional binaries get compiled, but are not installed by default.
1076 o There is also a temporary fix for a performance problem where too many
1077 events happen in parallel and every event needs to parse the rules.
1078 udev can now read precompiled rules stored on disk. This is likely to be
1079 replaced by a more elegant solution in a future udev version.
1083 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1084 Fix for libsysfs not to expect this file was added.
1088 All rules are applied now, but only the first matching rule with a NAME-key
1089 will be applied. All later rules with NAME-key are completely ignored. This
1090 way system supplied symlinks or permissions gets applied to user-defined
1094 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1095 to some rules, to keep the old behavior.
1097 The rules are read on "remove"-events too. That makes is possible to match
1098 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1099 instruct udev to ignore an event (OPTIONS="ignore_device").
1100 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1102 The new RUN-key supports rule-based execution of programs after device-node
1103 handling. This is meant as a general replacement for the dev.d/-directories
1104 to give fine grained control over the execution of programs.
1106 The %s{}-sysfs format char replacement values are searched at any of the
1107 devices in the device chain now, not only at the class-device.
1109 We support log priority levels now. The value udev_log in udev.conf is used
1110 to determine what is printed to syslog. This makes it possible to
1111 run a version with compiled-in debug messages in a production environment
1112 which is sometimes needed to find a bug.
1113 It is still possible to supress the inclusion of _any_ syslog usage with
1114 USE_LOG=false to create the smallest possible binaries if needed.
1115 The configured udev_log value can be overridden with the environment variable
1120 Possible use of a system-wide klibc:
1121 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1122 will link against an external klibc and our own version will be ignored.
1126 We support an unlimited count of symlinks now.
1128 If USE_STATIC=true is passed to a glibc build, we link statically and use
1129 a built-in userdb parser to resolve user and group names.
1131 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1132 we walk up the chain of physical devices to find a match.
1134 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1135 easy to skip certain attribute matches without composing rules with weird
1136 character class negations like:
1137 KERNEL="[!s][!c][!d]*"
1138 this can now be replaced with:
1140 The current simple '=' is still supported, and should work as it does today,
1141 but existing rules should be converted if possible, to be better readable.
1143 We have new ENV{}== key now, to match against a maximum of 5 environment
1146 udevstart is its own binary again, because we don't need co carry this araound
1147 with every forked event.
~ianmdlvl / elogind.git / blob