5 The program vol_id is removed from the repository and blkid from the
6 latest util-linux-ng package replaces it. Persisten disk links for
7 label and uuid depend on the util-linux-ng version of blkid now. Older
8 versions can not be used with udev.
10 Libudev allows to subscribe to udev events. To prevent unwanted messages
11 to be delivered, and waking up the subscribing process, a filter can be
12 installed, to drop messages inside a kernel socket filter. The filters
13 match on the <subsytem>:<devtype> properties of the device.
14 This is part of the ongoing effort to replace HAL, and switch current
15 users over to directly use libudev, or for higher-level services use the
16 specialized D-Bus interface of a DeviceKit service.
17 Libudev is still marked as experimental, and its interface might
18 change if needed, but no major changes of the currently exported interface
19 are expected anymore, and a first stable release should happen soon.
21 A too old kernel (2.6.21) or a kernel with CONFIG_SYSFS_DEPRECATED
22 is not supported since while and udevd will log an error message at
23 startup. It should still be able to boot-up, but advanced rules and system
24 services which depend on the information not available in the old sysfs
25 format will fail to work correctly.
27 DVB device naming is supplied by the kernel now. In case older kernels
28 need to be supported, the old shell script should be added to a compat
35 The processed udev events get send back to the netlink socket. Libudev
36 provides access to these events. This is work-in-progress, to replace
37 the DeviceKit daemon functionality directly with libudev. There are
38 upcoming kernel changes to allow non-root users to subcribe to these
45 "udevadm settle" now optionally accepts a range of events to wait for,
46 instead of waiting for "all" events.
52 The installed watch for block device metadata changes is now removed
53 during event hadling, because some (broken) tools may be called from udev
54 rules and (wrongly) open the device with write access. After the finished
55 event handling the watch is restored.
61 Device nodes can be watched for changes with inotify with OPTIONS="watch".
62 If closed after being opened for writing, a "change" uevent will occur.
63 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
69 The udevadm test command has no longer a --force option, nodes and symlinks
70 are always updated with a test run now.
72 The udevd daemon can be started with --resolve-names=never to avoid all user
73 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
74 lookup user and groups every time events are handled.
80 We are currently merging the Ubuntu rules in the udev default rules,
81 and get one step closer to provide a common Linux /dev setup, regarding
82 device names, symlinks, and default device permissions. On udev startup,
83 we now expect the following groups to be resolvable to their ids with
85 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
86 LDAP setups need to make sure, that these groups are always resolvable at
87 bootup, with only the rootfs mounted, and without network access available.
89 Some systems may need to add some new, currently not used groups, or need
90 to add some users to new groups, but the cost of this change is minimal,
91 compared to the pain the current, rather random, differences between the
92 various distributions cause for upstream projects and third-party vendors.
94 In general, "normal" users who log into a machine should never be a member
95 of any such group, but the device-access should be managed by dynamic ACLs,
96 which get added and removed for the specific users on login/logout and
97 session activity/inactivity. These groups are only provided for custom setups,
98 and mainly system services, to allow proper privilege separation.
99 A video-streaming daemon uid would be a member of "audio" and "video", to get
100 access to the sound and video devices, but no "normal" user should ever belong
101 to the "audio" group, because he could listen to the built-in microphone with
102 any ssh-session established from the other side of the world.
104 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
105 which do not depend on the kernel device name. As usual, unique
106 devices - only a single one per product connected, or a real
107 USB serial number in the device - are always found with the same
108 name in the by-id/ directory.
109 Completely identical devices may overwrite their names in by-id/
110 and can only be found reliably in the by-path/ directory. Devices
111 specified by by-path/ must not change their connection, like the
112 USB port number they are plugged in, to keep their name.
114 To support some advanced features, Linux 2.6.22 is the oldest supported
115 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
116 supported. Older kernels should still work, and devices nodes should be
117 reliably created, but some rules and libudev will not work correctly because
118 the old kernels do not provide the expected information or interfaces.
124 Fix for a possible segfault while swapping network interface names in udev
131 The group "video" is part of the default rules now.
135 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
136 block devices in some cases. No common distro uses this option anymore,
137 and we do not get enough testing for this and recent udev versions. If
138 this option is not needed to run some old distro with a new kernel,
139 it should be disabled in the kernel config.
141 Bugfix for the $links substitution variable, which may crash if no links
142 are created. This should not happen in usual setups because we always
143 create /dev/{block,char}/ links.
145 The strings of the parsed rules, which are kept in memory, no longer
146 contain duplicate entries, or duplicate tails of strings. This, and the
147 new rules parsing/matching code reduces the total in-memory size of
148 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
151 The export of DEVTYPE=disk/partition got removed from the default
152 rules. This value is available from the kernel. The pnp shell script
153 modprobe hack is removed from the default rules. ACPI devices have _proper_
154 modalias support and take care of the same functionality.
155 Installations which support old kernels, but install current default
156 udev rules may want to add that to the compat rules file.
158 Libvolume_id now always probes for all known filesystems, and does not
159 stop at the first match. Some filesystems are marked as "exclusive probe",
160 and if any other filesytem type matches at the same time, libvolume_id
161 will, by default, not return any probing result. This is intended to prevent
162 mis-detection with conflicting left-over signatures found from earlier
163 file system formats. That way, we no longer depend on the probe-order
164 in case of multiple competing signatures. In some setups the kernel allows
165 to mount a volume with just the old filesystem signature still in place.
166 This may damage the new filesystem and cause data-loss, just by mounting
167 it. Because volume_id can not decide which one the correct signature is,
168 the wrong signatures need to be removed manually from the volume, or the
169 volume needs to be reformatted, to enable filesystem detection and possible
174 Fix segfault if compiled without optimization and dbg() does not get
175 compiled out and uses variables which are not available.
179 Bugfixes. (And maybe new bugs. :))
181 The rule matching engine got converted from a rule list to a token
182 array which reduced the in-memory rules representation of a full
183 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
184 Limits like 5 ENV and ATTR matches, and one single instance for most
185 other keys per rule are gone.
187 The NAME assignment is no longer special cased. If later rules assign
188 a NAME value again, the former value will be overwritten. As usual
189 for most other keys, the NAME value can be protected by doing a final
190 assignment with NAME:="<value>".
192 All udev code now uses libudev, which is also exported. The library
193 is still under development, marked as experimental, and its interface
194 may change as long as the DeviceKit integration is not finished.
196 Many thanks to Alan Jenkins for his continuous help, and finding and
197 optimizing some of the computing expensive parts.
203 Kernel devices and device nodes are connected now by reverse indizes in
204 /sys and /dev. A device number retrieved by a stat() or similar, the
205 kernel device directory can be found by looking up:
206 /sys/dev/{block,char}/<maj>:<min>
207 and the device node of the same device by looking up:
208 /dev/{block,char}/<maj>:<min>
212 Fix recently introduced bug, which caused a compilation without large
213 file support, where vol_id does not recognize raid signatures at the end
216 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
217 Seems some kernel versions prevent the creation of the ieee-* links,
218 so people used the scsi-* link which disappeared now.
220 More libudev work. Almost all udevadm functionality comes from libudev
223 udevadm trigger has a new option --type, which allows to trigger events
224 for "devices", for "subsystems", or "failed" devices. The old option
225 --retry-failed" still works, but is no longer mentioned in the man page.
231 The udevadm info --device-id-of-file= output has changed to use
232 the obvious format. Possible current users should use the --export
233 option which is not affected.
235 The old udev commands symlinks to udevadm are not installed, if
236 these symlinks are used, a warning is printed.
242 Optical drive's media is no longer probed for raid signatures,
243 reading the end of the device causes some devices to malfunction.
244 Also the offset of the last session found is used now to probe
247 The volume_id library got a major version number update to 1,
248 some deprecated functions are removed.
250 A shared library "libudev" gets installed now to provide access
251 to udev device information. DeviceKit, the successor of HAL, will
252 need this library to access the udev database and search sysfs for
254 The library is currently in an experimental state, also the API is
255 expected to change, as long as the DeviceKit integration is not
260 We use ./configure now. See INSTALL for details. Current
263 "/usr" - prefix for man pages, include files
265 "" - the root filesystem, prefix for libs and binaries
269 "lib" - directory name for libraries, not a path name
270 multilib 64bit systems may use "lib64" instead of "lib"
272 compile-in verbose debug messages
274 disable all logging and compile-out all log strings
276 link against SELInux libraries, to set the expected context
279 In the default rules, the group "disk" gets permissions 0660 instead
280 of 0640. One small step closer to unify distro rules. Some day, all
281 distros hopefully end up with the same set of rules.
283 No symlinks to udevadm are installed anymore, if they are still needed,
284 they should be provided by the package.
290 Default udev rules, which are not supposed to be edited by the user, should
291 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
292 the udev package and will be replaced with an update. Udev will pick up rule
294 /lib/udev/rules.d/ - default installed rules
295 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
296 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
297 It does not matter in which directory a rule file lives, all files are sorted
300 To help creating /dev/root, we have now:
301 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
304 In case the current --device-id-of-file is already used, please switch to
305 the --export format version, it saves the output parsing and the old
306 format will be changed to use ':' as a separator, like the format in the
311 Fix cdrom_id to properly recognize blank media.
317 Tape drive id-data is queried from /dev/bsg/* instead of the tape
318 nodes. This avoids rewinding tapes on open().
324 The symlinks udevcontrol and udevtrigger are no longer installed by
327 The scsi_id program does not depend on sysfs anymore. It can speak
328 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
329 data, which should solve some old problems with tape devices, where
330 we better do not open all tape device nodes to identify the device.
336 The cdrom_id program is replaced by an advanced version, which can
337 detect most common device types, and also properties of the inserted
338 media. This is part of moving some basic functionality from HAL into
339 udev (and the kernel).
345 The last WAIT_FOR_SYSFS rule is removed from the default rules.
347 The symlinks to udevadm for the debugging tools: udevmonitor and
348 udevtest are no longer created.
350 The symlinks to the udevadm man page for the old tool names are
353 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
354 should be prefixed with '@' to indicate that the path is not a
365 Udevstart is removed from the tree, it did not get installed for
366 a long time now, and is long replaced by trigger and settle.
372 All udev tools are merged into a single binary called udevadm.
373 The old names of the tools are built-in commands in udevadm now.
374 Symlinks to udevadm, with the names of the old tools, provide
375 the same functionality as the standalone tools. There is also
376 only a single udevadm.8 man page left for all tools.
378 Tools like mkinitramfs should be checked, if they need to include
379 udevadm in the list of files.
389 The etc/udev/rules.d/ directory now contains a default set of basic
390 udev rules. This initial version is the result of a rules file merge
391 of Fedora and openSUSE. For these both distros only a few specific
392 rules are left in their own file, named after the distro. Rules which
393 are optionally installed, because they are only valid for a specific
394 architecture, or rules for subsystems which are not always used are
395 in etc/udev/packages/.
401 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
402 actions by dynamically created rules.
404 SYMLINK=="<value>" matches agains the entries in the list of
405 currently defined symlinks. The links are not created in the
406 filesystem at that point in time, but the values can be matched.
408 RUN{ignore_error}+="<program>" will ignore any exit code from the
409 program and not record as a failed event.
415 Final merge of patches/features from the Ubuntu package.
421 Control characters in filesystem label strings are no longer silenty
422 removed, but hex-encoded, to be able to uniquely identify the device
423 by its symlink in /dev/disk/by-label/.
424 If libvolume_id is used by mount(8), LABEL= will work as expected,
425 if slashes or other characters are used in the label string.
427 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
428 can be specified now. The TEST key accepts an optional mode mask
429 TEST{0100}=="<is executable file>".
431 Scsi_id now supports a mode without expecting scsi-specific sysfs
432 entries to allow the extraction of cciss-device persistent properties.
438 In the future, we may see uuid's which are just simple character
439 strings (see the DDF Raid Specification). For that reason vol_id now
440 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
441 the creation of symlinks, the *_SAFE values ensure, that no control
442 or whitespace characters are used in the filename.
444 Possible users of libvolume_id, please use the volume_id_get_* functions.
445 The public struct will go away in a future release of the library.
451 Removal of useless extras/eventrecorder.sh.
461 The directory multiplexer for dev.d/ and hotplug.d are finally removed
462 from the udev package.
468 Symlinks can have priorities now, the priority is assigned to the device
469 and specified with OPTIONS="link_priority=100". Devices with higher
470 priorities overwrite the symlinks of devices with lower priorities.
471 If the device that currently owns the link, goes away, the symlink
472 will be removed, and recreated, pointing to the next device with the
473 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
474 more reliable, if multiple devices contain the same metadata and overwrite
477 The dasd_id program is removed from the udev tree, and dasdinfo, with the
478 needed rules, are part of the s390-tools now.
480 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
481 we may get the scsi sysfs mess fixed some day, and this will only catch
482 the devices we are looking for.
484 USB serial numbers for storage devices have the target:lun now appended,
485 to make it possibble to distinguish broken multi-lun devices with all
486 the same SCSI identifiers.
488 Note: The extra "run_directory" which searches and executes stuff in
489 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
490 with the next release. Make sure, that you don't use it anymore, or
491 provides your own implementation of that inefficient stuff.
492 We are tired of reports about a "slow udev", because these directories
493 contain stuff, that runs with _every_ event, instead of using rules,
494 that run programs only for the matching events.
504 DRIVER== will match only for devices that actually have a real
505 driver. DRIVERS== must be used, if parent devices should be
506 included in the match.
508 Libvolume_id's "linux_raid" detection needed another fix.
516 Add additional check to volume_id detection of via_raid, cause
517 some company decided to put a matching pattern all over the empty
518 storage area of their music players.
522 Fix path_id for SAS devices.
526 The udev daemon can be started with --debug-trace now, which will
527 execute all events serialized to get a chance to catch a possible
528 action that crashes the box.
530 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
531 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
532 are excluded from the warning. Referencing parent attributes directly
533 may break when something in the kernel driver model changes. Udev will
534 just find the attribute by walking up the parent chain.
536 Udevtrigger now sorts the list of devices depending on the device
537 dependency, so a "usb" device is triggered after the parent "pci"
542 Revert persistent-storage ata-serial '_' '-' replacement.
548 Udevtrigger can now filter the list of devices to be triggered. Matches
549 for subsystems or sysfs attributes can be specified.
551 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
552 zero-sized files to avoid pointing to /sys and confuse broken tools which
553 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
556 The rules and scripts to create udev rules for persistent network
557 devices and optical drives are in the extras/rules_generator directory
558 now. If you use something similar, please consider replacing your own
559 version with this, to share the support effort. The rule_generator
560 installs its own rules into /etc/udev/rules.d.
562 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
563 the rule_generator depends on cdrom_id to be called in an earlier rule.
569 Renaming of some key names (the old names still work):
570 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
571 (The behavior of the key DRIVER will change soon in one of the next
572 releases, to match only the event device, please switch to DRIVERS
573 instead. If DRIVER is used, it will behave like DRIVERS, but an error
575 With the new key names, we have a more consistent and simpler scheme.
576 We can match the properties of the event device only, with: KERNEL,
577 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
578 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
579 longer mentioned in the man page and should be switched in the rule
582 ATTR{file}="value" can be used now, to write to a sysfs file of the
583 event device. Instead of:
584 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
586 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
588 All the PHYSDEV* keys are deprecated and will be removed from a
590 PHYDEVPATH - is the path of a parent device and should not be
592 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
593 matched with SUBSYSTEMS==
594 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
595 Newer kernels will have DRIVER in the environment,
596 for older kernels udev puts in. Class device will
597 no longer carry this property of a parent and
598 DRIVERS== can be used to match such a parent value.
599 Note that ENV{DRIVER} is only available for a few bus devices, where
600 the driver is already bound at device event time. On coldplug, the
601 events for a lot devices are already bound to a driver, and they will have
602 that value set. But on hotplug, at the time the kernel creates the device,
603 it can't know what driver may claim the device after that, therefore
604 in most cases it will be empty.
606 Failed events should now be re-triggered with:
607 udevtrigger --retry-failed.
608 Please switch to this command, so we keep the details of the /dev/.udev/failed/
609 files private to the udev tools. We may need to switch the current symlink
610 target, cause some obviously broken tools try to scan all files in /dev
611 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
612 million times. This takes ages on slow boxes.
614 The udevinfo attribute walk (-a) now works with giving a device node
615 name (-n) instead of a devpath (-p). The query now always works, also when
616 no database file was created by udev.
618 The built-in /etc/passwd /etc/group parser is removed, we always depend on
619 getpwnam() and getgrnam() now. One of the next releases will depend on
620 fnmatch() and may use getopt_long().
624 Bugfixes and small improvements.
628 Fix path_id for recent kernels.
634 Added support for swapping network interface names, by temporarily
635 renaming the device and wait for the target name to become free.
639 The built-in MODALIAS key and substitution is removed.
643 The binary firmware helper is replaced by the usual simple
644 shell script. Udevsend is removed from the tree.
652 Some more keys require the correct use of '==' and '=' depending
653 on the kind of operation beeing an assignment or a match. Rules
654 with invalid operations are skipped and logged to syslog. Please
655 test with udevtest if the parsing of your rules throws errors and
656 fix possibly broken rules.
660 Provide "udevsettle" to wait for all current udev events to finish.
661 It also watches the current kernel netlink queue by comparing the
662 even sequence number to make sure that there are no current pending
663 events that have not already arrived in the daemon.
667 Fix rule to skip persistent rules for removable IDE devices, which
668 also skipped optical IDE drives.
670 All *_id program are installed in /lib/udev/ by default now.
672 No binary is stripped anymore as this should be done in the
673 packaging process and not at build time.
675 libvolume_id is provided as a shared library now and vol_id is
676 linked against it. Also one of the next HAL versions will require
677 this library, and the HAL build process will also require the
678 header file to be installed. The copy of the same code in HAL will
679 be removed to have only a single copy left on the system.
683 Add persistent links for SCSI tapes. The rules file is renamed
684 to 60-persistent-storage.rules.
686 Create persistent path for usb devices. Can be used for all sorts
687 of devices that can't be distinguished by other properties like
688 multiple identical keyboards and mice connected to the same box.
690 Provide "udevtrigger" program to request events on coldplug. The
691 shell script is much too slow with thousends of devices.
695 Fix persistent disk rules to exclude removable IDE drives.
697 Warn if %e, $modalias or MODALIAS is used.
701 Fix queue export, which wasn't correct for subsequent add/remove
702 events for the same device.
706 Fix cramfs detection on big endian.
708 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
713 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
714 attributes were only checked at the parent device that matched the
715 by BUS requested subsystem. Fix it to also look at the device we
716 received the event for.
718 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
723 Fix a bug where NAME="" would prevent RUN from beeing executed.
725 RUN="/bin/program" does not longer automatically add the subsystem
726 as the first parameter. This is from the days of /sbin/hotplug
727 which is dead now and it's just confusing to need to add a space at
728 the end of the program name to prevent this.
729 If you use rules that need the subsystem as the first parameter,
730 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
731 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
735 The udev man page has moved to udev(7) as it does not describe a command
736 anymore. The programs udev, udevstart and udevsend are no longer installed
737 by default and must be copied manually, if they should be installed or
738 included in a package.
740 Fix a bug where "ignore_device" could run earlier collected RUN keys before
741 the ignore rule was applied.
743 More preparation for future sysfs changes. usb_id and scsi_id no longer
744 depend on a magic order of devices in the /devices chain. Specific devices
745 should be requested by their subsytem.
747 This will always find the scsi parent device without depending on a specific
749 dev = sysfs_device_get(devpath);
750 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
752 The "device" link in the current sysfs layout will be automatically
753 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
754 parent in the devpath. If a device is requested by it's symlink, like all
755 class devices in the new sysfs layout will look like, it gets automatically
756 resolved and substituted with the real devpath and not the symlink path.
759 A similar logic must be applied to _all_ sysfs users, including
760 scripts, that search along parent devices in sysfs. The explicit use of
761 the "device" link must be avoided. With the future sysfs layout all
762 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
763 back to the "class" or the "bus". The layout of the parent devices in
764 /devices is not necessarily expected to be stable across kernel releases and
765 searching for parents by their subsystem should make sysfs users tolerant
766 for changed parent chains.
770 Prepare udev to work with the experimental kernel patch, that moves
771 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
773 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
774 moving the class devices to /sys/devices.
776 Thanks again to Marco for help finding a hopefully nice compromise
777 to make %b simpler and working again.
781 Complete removal of libsysfs, replaced by simple helper functions
782 which are much simpler and a bit faster. The udev daemon operatesentirely
783 on event parameters and does not use sysfs for simple rules anymore.
784 Please report any new bugs/problems, that may be caused by this big
785 change. They will be fixed immediately.
787 The enumeration format character '%e' is deprecated and will be
788 removed sometimes from a future udev version. It never worked correctly
789 outside of udevstart, so we can't use it with the new parallel
790 coldplug. A simple enumeration is as useless as the devfs naming
791 scheme, just get rid of both if you still use it.
793 MODALIAS and $modalias is not needed and will be removed from one of
794 the next udev versions, replace it in all rules with ENV{MODALIAS} or
795 the sysfs "modalias" value.
797 Thanks a lot to Marco for all his help on finding and fixing bugs.
801 Let scsi_id request libata drive serial numbers from page 0x80.
803 Renamed etc/udev/persistent.rules to persistent-disk.rules and
804 added /dev/disk/by-name/* for device mapper device names.
806 Removed %e from the man page. It never worked reliably outside
807 of udevstart and udevstart is no longer recommended to use.
811 Symlinks are now exported to the event environment. Hopefully it's no
812 longer needed to run udevinfo from an event process, like it was
813 mentioned on the hotplug list:
814 UDEV [1134776873.702967] add@/block/sdb
817 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
821 Fix a problem if udevsend is used as the hotplug handler and tries to use
822 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
823 and this kind of problems will hopefully go away soon.
827 All built-in logic to work around bad sysfs timing is removed with this
828 version. The need to wait for sysfs files is almost fixed with a kernel
829 version that doesn't work with this udev version anyway. Until we fix
830 the timing of the "bus" link creation, the former integrated logic should
831 be emulated by a rule placed before all other rules:
832 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
834 The option "udev_db" does no longer exist. All udev state will be in
835 /$udev_root/.udev/ now, there is no longer an option to set this
837 If the init script or something else used this value, just depend on
838 this hardcoded path. But remember _all_content_ of this directory is
839 still private to udev and can change at any time.
841 Default location for rule sripts and helper programs is now: /lib/udev/.
842 Everything that is not useful on the commandline should go into this
843 directory. Some of the helpers in the extras folder are installed there
844 now. The rules need to be changed, to find the helpers there.
846 Also /lib/udev/devices is recommended as a directory where packages or
847 the user can place real device nodes, which get copied over to /dev at
848 every boot. This should replace the various solutions with custom config
851 Udevsend does no longer start the udev daemon. This must be done with
852 the init script that prepares /dev on tmpfs and creates the initial nodes,
853 before starting the daemon.
857 Silent a too verbose error logging for the old hotplug.d/ dev.d/
860 The copy of klibc is removed. A systemwide installed version of klibc
861 should be used to build a klibc udev now.
865 NAME="" will not create any nodes, but execute RUN keys. To completely
866 ignore an event the OPTION "ignore_device" should be used.
868 After removal of the reorder queue, events with a TIMEOUT can be executed
869 without any queuing now.
873 Fixed bug in udevd, if inotify is not available. We depend on netlink
874 uevents now, kernels without that event source will not work with that
875 version of udev anymore.
879 The rule parsing happens now in the daemon once at startup, all udev
880 event processes inherit the already parsed rules from the daemon.
881 It is shipped with SUSE10.0 and reduces heavily the system load at
882 startup. The option to save precompiled rules and let the udev process
883 pick the them up is removed, as it's no longer needed.
885 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
886 device. Libsysfs is changed to "translate" the requested link into the
887 real device path, as it would happen with the hotplug event. Otherwise
888 device removal and the udev database will not work.
890 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
893 A few improvements for vol_id, the filesytem probing code.
897 Fix a stupid typo in extras/run_directory for "make install".
899 scsi_id creates the temporary devnode now in /dev for usage with a
900 non-writable /tmp directory.
902 The uevent kernel socket buffer can carry app. 50.000 events now,
903 let's see who can break this again. :)
905 The upcoming kernel will have a new input driver core integration.
906 Some class devices are now symlinks to the real device. libsysfs
907 needs a fix for this to work correctly. Udevstart of older udev
908 versions will _not_ create these devices!
912 Fix a 'install' target in the Makefile, that prevents EXTRAS from
917 A bunch of mostly trivial bugfixes. From now on no node name or
918 symlink name can contain any character than plain whitelisted ascii
919 characters or validated utf8 byte-streams. This is needed for the
920 /dev/disk/by-label/* links, because we import untrusted data and
921 export it to the filesystem.
925 More bugfixes. If udevd was started from the kernel, we don't
926 have stdin/stdout/stderr, which broke the forked tools in some
931 Bugfix. udevstart event ordering was broken for a long time.
932 The new run_program() uncovered it, because /dev/null was not
933 available while we try to run external programs.
934 Now udevstart should create it before we run anything.
938 Minor bugfixes and some distro rules updates. If you don't have the
939 persistent disk rules in /dev/disk/by-*/* on your distro, just
940 grab it from here. :)
944 We can use socket communication now to pass events from udev to
946 RUN+="socket:/org/freedesktop/hal/udev_event"
947 will pass the whole udev event to the HAL daemon without the need
948 for a forked helper. (See ChangeLog for udevmonitor, as an example)
952 Mostly bugfixes and see ChangeLog.
954 The test for the existence of an environment value should be
956 ENV{KEY}=="*" to ENV{KEY}=="?*"
957 because "*" will not fail anymore, if the key does not exist or
962 Bugfixes and a few tweaks described in the ChangeLog.
966 Mostly a Bugfix release.
968 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
969 timing with custom rules.
973 We changed the internal rule storage format. Our large rule files took
974 2 MB of RAM, with the change we are down to 99kB.
976 If the device-node has been created with default name and no symlink or
977 options are to remenber, it is not longer stored in the udevdb. HAL will
978 need to be updated to work correctly with that change.
980 To overrride optimization flags, OPTFLAGS may be used now.
988 Major changes happened with this release. The goal is to take over the
989 complete kernel-event handling and provide a more efficient way to dispatch
990 kernel events. Replacing most of the current shell script logic and the
991 kernel forked helper with a netlink-daemon and a rule-based event handling.
993 o udevd listens to netlink events now. The first valid netlink event
994 will make udevd ignore any message from udevsend that contains a
995 SEQNUM, to avoid duplicate events. The forked events can be disabled
997 echo "" > /proc/sys/kernel/hotplug
998 For full support, the broken input-subsytem needs to be fixed, not to
999 bypass the driver core.
1001 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
1002 removed from udev itself and must be emulated by calling small
1003 helper binaries provided in the extras folder:
1004 make EXTRAS=extras/run_directory/
1005 will build udev_run_devd and udev_run_hotplugd, which can be called
1006 from a rule if needed:
1007 RUN+="/sbin/udev_run_hotplugd"
1008 The recommended way to handle this is to convert all the calls from
1009 the directories to explicit udev rules and get completely rid of the
1010 multiplexing. (To catch a ttyUSB event, you now no longer need to
1011 fork and exit 300 tty script instances you are not interested in, it
1012 is just one rule that matches exactly the device.)
1014 o udev handles now _all_ events not just events for class and block
1015 devices, this way it is possible to control the complete event
1016 behavior with udev rules. Especially useful for rules like:
1017 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
1019 o As used in the modalias rule, udev supports now textual
1020 substitution placeholder along with the usual format chars. This
1021 needs to be documented, for now it's only visible in udev_rules_parse.c.
1023 o The rule keys support now more operations. This is documented in the
1024 man page. It is possible to add values to list-keys like the SYMLINK
1025 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
1026 Also "final"-assignments are supported by using KEY:="value", which will
1027 prevent changing the key by any later rule.
1029 o kernel 2.6.12 has the "detached_state" attribute removed from
1030 sysfs, which was used to recognize sysfs population. We switched that
1031 to wait for the "bus" link, which is only available in kernels after 2.6.11.
1032 Running this udev version on older kernels may cause a short delay for
1035 o To provide infrastructure for persistent device naming, the id programs:
1036 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1037 to export the probed data in environment key format:
1038 pim:~ # /sbin/ata_id --export /dev/hda
1039 ID_MODEL=HTS726060M9AT00
1040 ID_SERIAL=MRH401M4G6UM9B
1041 ID_REVISION=MH4OA6BA
1043 The following rules:
1044 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1045 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1048 kay@pim:~> tree /dev/disk
1051 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1052 | `-- IBM-Memory_Key -> ../../sda
1054 | |-- swap -> ../../hda1
1055 | |-- date -> ../../sda1
1056 | `-- home -> ../../hda3
1058 |-- 2E08712B0870F2E7 -> ../../hda3
1059 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1060 |-- E845-7A89 -> ../../sda1
1061 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1063 The IMPORT= operation will import these keys in the environment and make
1064 it available for later PROGRAM= and RUN= executed programs. The keys are
1065 also stored in the udevdb and can be queried from there with one of the
1068 o A few binaries are silently added to the repository, which can be used
1069 to replay kernel events from initramfs instead of using coldplug. udevd
1070 can be instructed now to queue-up events while the stored events from
1071 initramfs are filled into the udevd-queue. This code is still under
1072 development and there is no documentation now besides the code itself.
1073 The additional binaries get compiled, but are not installed by default.
1075 o There is also a temporary fix for a performance problem where too many
1076 events happen in parallel and every event needs to parse the rules.
1077 udev can now read precompiled rules stored on disk. This is likely to be
1078 replaced by a more elegant solution in a future udev version.
1082 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1083 Fix for libsysfs not to expect this file was added.
1087 All rules are applied now, but only the first matching rule with a NAME-key
1088 will be applied. All later rules with NAME-key are completely ignored. This
1089 way system supplied symlinks or permissions gets applied to user-defined
1093 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1094 to some rules, to keep the old behavior.
1096 The rules are read on "remove"-events too. That makes is possible to match
1097 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1098 instruct udev to ignore an event (OPTIONS="ignore_device").
1099 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1101 The new RUN-key supports rule-based execution of programs after device-node
1102 handling. This is meant as a general replacement for the dev.d/-directories
1103 to give fine grained control over the execution of programs.
1105 The %s{}-sysfs format char replacement values are searched at any of the
1106 devices in the device chain now, not only at the class-device.
1108 We support log priority levels now. The value udev_log in udev.conf is used
1109 to determine what is printed to syslog. This makes it possible to
1110 run a version with compiled-in debug messages in a production environment
1111 which is sometimes needed to find a bug.
1112 It is still possible to supress the inclusion of _any_ syslog usage with
1113 USE_LOG=false to create the smallest possible binaries if needed.
1114 The configured udev_log value can be overridden with the environment variable
1119 Possible use of a system-wide klibc:
1120 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1121 will link against an external klibc and our own version will be ignored.
1125 We support an unlimited count of symlinks now.
1127 If USE_STATIC=true is passed to a glibc build, we link statically and use
1128 a built-in userdb parser to resolve user and group names.
1130 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1131 we walk up the chain of physical devices to find a match.
1133 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1134 easy to skip certain attribute matches without composing rules with weird
1135 character class negations like:
1136 KERNEL="[!s][!c][!d]*"
1137 this can now be replaced with:
1139 The current simple '=' is still supported, and should work as it does today,
1140 but existing rules should be converted if possible, to be better readable.
1142 We have new ENV{}== key now, to match against a maximum of 5 environment
1145 udevstart is its own binary again, because we don't need co carry this araound
1146 with every forked event.
~ianmdlvl / elogind.git / blob