5 For some more advanced features Linux 2.6.22 is the oldest supported
6 version now. The kernel config with enabled SYSFS_DEPRECATED
7 is no longer supported. Older kernels should still work, and devices
8 nodes should be reliably created, but some rules and libudev will
9 not work correctly because the old kernels do not provide the expected
10 information or interfaces.
12 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
13 which do not depend on the kernel device name. As usual, unique
14 devices - only a single one per product connected, or a real
15 USB serial number in the device - are always found with the same
16 name in the by-id/ directory.
17 Completely Identical devices may overwrite their names in by-id/
18 and can only be found reliably in the by-path/ directory. Devices
19 specified by by-path/ must not change their connection, like the
20 USB port number they are plugged in, to keep their name.
26 Fix for a possible segfault while swapping network interface names in udev
33 The group "video" is part of the default rules now.
37 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
38 block devices in some cases. No common distro uses this option anymore,
39 and we do not get enough testing for this and recent udev versions. If
40 this option is not needed to run some old distro with a new kernel,
41 it should be disabled in the kernel config.
43 Bugfix for the $links substitution variable, which may crash if no links
44 are created. This should not happen in usual setups because we always
45 create /dev/{block,char}/ links.
47 The strings of the parsed rules, which are kept in memory, no longer
48 contain duplicate entries, or duplicate tails of strings. This, and the
49 new rules parsing/matching code reduces the total in-memory size of
50 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
53 The export of DEVTYPE=disk/partition got removed from the default
54 rules. This value is available from the kernel. The pnp shell script
55 modprobe hack is removed from the default rules. ACPI devices have _proper_
56 modalias support and take care of the same functionality.
57 Installations which support old kernels, but install current default
58 udev rules may want to add that to the compat rules file.
60 Libvolume_id now always probes for all known filesystems, and does not
61 stop at the first match. Some filesystems are marked as "exclusive probe",
62 and if any other filesytem type matches at the same time, libvolume_id
63 will, by default, not return any probing result. This is intended to prevent
64 mis-detection with conflicting left-over signatures found from earlier
65 file system formats. That way, we no longer depend on the probe-order
66 in case of multiple competing signatures. In some setups the kernel allows
67 to mount a volume with just the old filesystem signature still in place.
68 This may damage the new filesystem and cause data-loss, just by mounting
69 it. Because volume_id can not decide which one the correct signature is,
70 the wrong signatures need to be removed manually from the volume, or the
71 volume needs to be reformatted, to enable filesystem detection and possible
76 Fix segfault if compiled without optimization and dbg() does not get
77 compiled out and uses variables which are not available.
81 Bugfixes. (And maybe new bugs. :))
83 The rule matching engine got converted from a rule list to a token
84 array which reduced the in-memory rules representation of a full
85 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
86 Limits like 5 ENV and ATTR matches, and one single instance for most
87 other keys per rule are gone.
89 The NAME assignment is no longer special cased. If later rules assign
90 a NAME value again, the former value will be overwritten. As usual
91 for most other keys, the NAME value can be protected by doing a final
92 assignment with NAME:="<value>".
94 All udev code now uses libudev, which is also exported. The library
95 is still under development, marked as experimental, and its interface
96 may change as long as the DeviceKit integration is not finished.
98 Many thanks to Alan Jenkins for his continuous help, and finding and
99 optimizing some of the computing expensive parts.
105 Kernel devices and device nodes are connected now by reverse indizes in
106 /sys and /dev. A device number retrieved by a stat() or similar, the
107 kernel device directory can be found by looking up:
108 /sys/dev/{block,char}/<maj>:<min>
109 and the device node of the same device by looking up:
110 /dev/{block,char}/<maj>:<min>
114 Fix recently introduced bug, which caused a compilation without large
115 file support, where vol_id does not recognize raid signatures at the end
118 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
119 Seems some kernel versions prevent the creation of the ieee-* links,
120 so people used the scsi-* link which disappeared now.
122 More libudev work. Almost all udevadm functionality comes from libudev
125 udevadm trigger has a new option --type, which allows to trigger events
126 for "devices", for "subsystems", or "failed" devices. The old option
127 --retry-failed" still works, but is no longer mentioned in the man page.
133 The udevadm info --device-id-of-file= output has changed to use
134 the obvious format. Possible current users should use the --export
135 option which is not affected.
137 The old udev commands symlinks to udevadm are not installed, if
138 these symlinks are used, a warning is printed.
144 Optical drive's media is no longer probed for raid signatures,
145 reading the end of the device causes some devices to malfunction.
146 Also the offset of the last session found is used now to probe
149 The volume_id library got a major version number update to 1,
150 some deprecated functions are removed.
152 A shared library "libudev" gets installed now to provide access
153 to udev device information. DeviceKit, the successor of HAL, will
154 need this library to access the udev database and search sysfs for
156 The library is currently in an experimental state, also the API is
157 expected to change, as long as the DeviceKit integration is not
162 We use ./configure now. See INSTALL for details. Current
165 "/usr" - prefix for man pages, include files
167 "" - the root filesystem, prefix for libs and binaries
171 "lib" - directory name for libraries, not a path name
172 multilib 64bit systems may use "lib64" instead of "lib"
174 compile-in verbose debug messages
176 disable all logging and compile-out all log strings
178 link against SELInux libraries, to set the expected context
181 In the default rules, the group "disk" gets permissions 0660 instead
182 of 0640. One small step closer to unify distro rules. Some day, all
183 distros hopefully end up with the same set of rules.
185 No symlinks to udevadm are installed anymore, if they are still needed,
186 they should be provided by the package.
192 Default udev rules, which are not supposed to be edited by the user, should
193 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
194 the udev package and will be replaced with an update. Udev will pick up rule
196 /lib/udev/rules.d/ - default installed rules
197 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
198 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
199 It does not matter in which directory a rule file lives, all files are sorted
202 To help creating /dev/root, we have now:
203 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
206 In case the current --device-id-of-file is already used, please switch to
207 the --export format version, it saves the output parsing and the old
208 format will be changed to use ':' as a separator, like the format in the
213 Fix cdrom_id to properly recognize blank media.
219 Tape drive id-data is queried from /dev/bsg/* instead of the tape
220 nodes. This avoids rewinding tapes on open().
226 The symlinks udevcontrol and udevtrigger are no longer installed by
229 The scsi_id program does not depend on sysfs anymore. It can speak
230 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
231 data, which should solve some old problems with tape devices, where
232 we better do not open all tape device nodes to identify the device.
238 The cdrom_id program is replaced by an advanced version, which can
239 detect most common device types, and also properties of the inserted
240 media. This is part of moving some basic functionality from HAL into
241 udev (and the kernel).
247 The last WAIT_FOR_SYSFS rule is removed from the default rules.
249 The symlinks to udevadm for the debugging tools: udevmonitor and
250 udevtest are no longer created.
252 The symlinks to the udevadm man page for the old tool names are
255 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
256 should be prefixed with '@' to indicate that the path is not a
267 Udevstart is removed from the tree, it did not get installed for
268 a long time now, and is long replaced by trigger and settle.
274 All udev tools are merged into a single binary called udevadm.
275 The old names of the tools are built-in commands in udevadm now.
276 Symlinks to udevadm, with the names of the old tools, provide
277 the same functionality as the standalone tools. There is also
278 only a single udevadm.8 man page left for all tools.
280 Tools like mkinitramfs should be checked, if they need to include
281 udevadm in the list of files.
291 The etc/udev/rules.d/ directory now contains a default set of basic
292 udev rules. This initial version is the result of a rules file merge
293 of Fedora and openSUSE. For these both distros only a few specific
294 rules are left in their own file, named after the distro. Rules which
295 are optionally installed, because they are only valid for a specific
296 architecture, or rules for subsystems which are not always used are
297 in etc/udev/packages/.
303 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
304 actions by dynamically created rules.
306 SYMLINK=="<value>" matches agains the entries in the list of
307 currently defined symlinks. The links are not created in the
308 filesystem at that point in time, but the values can be matched.
310 RUN{ignore_error}+="<program>" will ignore any exit code from the
311 program and not record as a failed event.
317 Final merge of patches/features from the Ubuntu package.
323 Control characters in filesystem label strings are no longer silenty
324 removed, but hex-encoded, to be able to uniquely identify the device
325 by its symlink in /dev/disk/by-label/.
326 If libvolume_id is used by mount(8), LABEL= will work as expected,
327 if slashes or other characters are used in the label string.
329 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
330 can be specified now. The TEST key accepts an optional mode mask
331 TEST{0100}=="<is executable file>".
333 Scsi_id now supports a mode without expecting scsi-specific sysfs
334 entries to allow the extraction of cciss-device persistent properties.
340 In the future, we may see uuid's which are just simple character
341 strings (see the DDF Raid Specification). For that reason vol_id now
342 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
343 the creation of symlinks, the *_SAFE values ensure, that no control
344 or whitespace characters are used in the filename.
346 Possible users of libvolume_id, please use the volume_id_get_* functions.
347 The public struct will go away in a future release of the library.
353 Removal of useless extras/eventrecorder.sh.
363 The directory multiplexer for dev.d/ and hotplug.d are finally removed
364 from the udev package.
370 Symlinks can have priorities now, the priority is assigned to the device
371 and specified with OPTIONS="link_priority=100". Devices with higher
372 priorities overwrite the symlinks of devices with lower priorities.
373 If the device that currently owns the link, goes away, the symlink
374 will be removed, and recreated, pointing to the next device with the
375 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
376 more reliable, if multiple devices contain the same metadata and overwrite
379 The dasd_id program is removed from the udev tree, and dasdinfo, with the
380 needed rules, are part of the s390-tools now.
382 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
383 we may get the scsi sysfs mess fixed some day, and this will only catch
384 the devices we are looking for.
386 USB serial numbers for storage devices have the target:lun now appended,
387 to make it possibble to distinguish broken multi-lun devices with all
388 the same SCSI identifiers.
390 Note: The extra "run_directory" which searches and executes stuff in
391 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
392 with the next release. Make sure, that you don't use it anymore, or
393 provides your own implementation of that inefficient stuff.
394 We are tired of reports about a "slow udev", because these directories
395 contain stuff, that runs with _every_ event, instead of using rules,
396 that run programs only for the matching events.
406 DRIVER== will match only for devices that actually have a real
407 driver. DRIVERS== must be used, if parent devices should be
408 included in the match.
410 Libvolume_id's "linux_raid" detection needed another fix.
418 Add additional check to volume_id detection of via_raid, cause
419 some company decided to put a matching pattern all over the empty
420 storage area of their music players.
424 Fix path_id for SAS devices.
428 The udev daemon can be started with --debug-trace now, which will
429 execute all events serialized to get a chance to catch a possible
430 action that crashes the box.
432 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
433 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
434 are excluded from the warning. Referencing parent attributes directly
435 may break when something in the kernel driver model changes. Udev will
436 just find the attribute by walking up the parent chain.
438 Udevtrigger now sorts the list of devices depending on the device
439 dependency, so a "usb" device is triggered after the parent "pci"
444 Revert persistent-storage ata-serial '_' '-' replacement.
450 Udevtrigger can now filter the list of devices to be triggered. Matches
451 for subsystems or sysfs attributes can be specified.
453 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
454 zero-sized files to avoid pointing to /sys and confuse broken tools which
455 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
458 The rules and scripts to create udev rules for persistent network
459 devices and optical drives are in the extras/rules_generator directory
460 now. If you use something similar, please consider replacing your own
461 version with this, to share the support effort. The rule_generator
462 installs its own rules into /etc/udev/rules.d.
464 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
465 the rule_generator depends on cdrom_id to be called in an earlier rule.
471 Renaming of some key names (the old names still work):
472 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
473 (The behavior of the key DRIVER will change soon in one of the next
474 releases, to match only the event device, please switch to DRIVERS
475 instead. If DRIVER is used, it will behave like DRIVERS, but an error
477 With the new key names, we have a more consistent and simpler scheme.
478 We can match the properties of the event device only, with: KERNEL,
479 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
480 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
481 longer mentioned in the man page and should be switched in the rule
484 ATTR{file}="value" can be used now, to write to a sysfs file of the
485 event device. Instead of:
486 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
488 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
490 All the PHYSDEV* keys are deprecated and will be removed from a
492 PHYDEVPATH - is the path of a parent device and should not be
494 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
495 matched with SUBSYSTEMS==
496 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
497 Newer kernels will have DRIVER in the environment,
498 for older kernels udev puts in. Class device will
499 no longer carry this property of a parent and
500 DRIVERS== can be used to match such a parent value.
501 Note that ENV{DRIVER} is only available for a few bus devices, where
502 the driver is already bound at device event time. On coldplug, the
503 events for a lot devices are already bound to a driver, and they will have
504 that value set. But on hotplug, at the time the kernel creates the device,
505 it can't know what driver may claim the device after that, therefore
506 in most cases it will be empty.
508 Failed events should now be re-triggered with:
509 udevtrigger --retry-failed.
510 Please switch to this command, so we keep the details of the /dev/.udev/failed/
511 files private to the udev tools. We may need to switch the current symlink
512 target, cause some obviously broken tools try to scan all files in /dev
513 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
514 million times. This takes ages on slow boxes.
516 The udevinfo attribute walk (-a) now works with giving a device node
517 name (-n) instead of a devpath (-p). The query now always works, also when
518 no database file was created by udev.
520 The built-in /etc/passwd /etc/group parser is removed, we always depend on
521 getpwnam() and getgrnam() now. One of the next releases will depend on
522 fnmatch() and may use getopt_long().
526 Bugfixes and small improvements.
530 Fix path_id for recent kernels.
536 Added support for swapping network interface names, by temporarily
537 renaming the device and wait for the target name to become free.
541 The built-in MODALIAS key and substitution is removed.
545 The binary firmware helper is replaced by the usual simple
546 shell script. Udevsend is removed from the tree.
554 Some more keys require the correct use of '==' and '=' depending
555 on the kind of operation beeing an assignment or a match. Rules
556 with invalid operations are skipped and logged to syslog. Please
557 test with udevtest if the parsing of your rules throws errors and
558 fix possibly broken rules.
562 Provide "udevsettle" to wait for all current udev events to finish.
563 It also watches the current kernel netlink queue by comparing the
564 even sequence number to make sure that there are no current pending
565 events that have not already arrived in the daemon.
569 Fix rule to skip persistent rules for removable IDE devices, which
570 also skipped optical IDE drives.
572 All *_id program are installed in /lib/udev/ by default now.
574 No binary is stripped anymore as this should be done in the
575 packaging process and not at build time.
577 libvolume_id is provided as a shared library now and vol_id is
578 linked against it. Also one of the next HAL versions will require
579 this library, and the HAL build process will also require the
580 header file to be installed. The copy of the same code in HAL will
581 be removed to have only a single copy left on the system.
585 Add persistent links for SCSI tapes. The rules file is renamed
586 to 60-persistent-storage.rules.
588 Create persistent path for usb devices. Can be used for all sorts
589 of devices that can't be distinguished by other properties like
590 multiple identical keyboards and mice connected to the same box.
592 Provide "udevtrigger" program to request events on coldplug. The
593 shell script is much too slow with thousends of devices.
597 Fix persistent disk rules to exclude removable IDE drives.
599 Warn if %e, $modalias or MODALIAS is used.
603 Fix queue export, which wasn't correct for subsequent add/remove
604 events for the same device.
608 Fix cramfs detection on big endian.
610 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
615 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
616 attributes were only checked at the parent device that matched the
617 by BUS requested subsystem. Fix it to also look at the device we
618 received the event for.
620 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
625 Fix a bug where NAME="" would prevent RUN from beeing executed.
627 RUN="/bin/program" does not longer automatically add the subsystem
628 as the first parameter. This is from the days of /sbin/hotplug
629 which is dead now and it's just confusing to need to add a space at
630 the end of the program name to prevent this.
631 If you use rules that need the subsystem as the first parameter,
632 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
633 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
637 The udev man page has moved to udev(7) as it does not describe a command
638 anymore. The programs udev, udevstart and udevsend are no longer installed
639 by default and must be copied manually, if they should be installed or
640 included in a package.
642 Fix a bug where "ignore_device" could run earlier collected RUN keys before
643 the ignore rule was applied.
645 More preparation for future sysfs changes. usb_id and scsi_id no longer
646 depend on a magic order of devices in the /devices chain. Specific devices
647 should be requested by their subsytem.
649 This will always find the scsi parent device without depending on a specific
651 dev = sysfs_device_get(devpath);
652 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
654 The "device" link in the current sysfs layout will be automatically
655 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
656 parent in the devpath. If a device is requested by it's symlink, like all
657 class devices in the new sysfs layout will look like, it gets automatically
658 resolved and substituted with the real devpath and not the symlink path.
661 A similar logic must be applied to _all_ sysfs users, including
662 scripts, that search along parent devices in sysfs. The explicit use of
663 the "device" link must be avoided. With the future sysfs layout all
664 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
665 back to the "class" or the "bus". The layout of the parent devices in
666 /devices is not necessarily expected to be stable across kernel releases and
667 searching for parents by their subsystem should make sysfs users tolerant
668 for changed parent chains.
672 Prepare udev to work with the experimental kernel patch, that moves
673 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
675 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
676 moving the class devices to /sys/devices.
678 Thanks again to Marco for help finding a hopefully nice compromise
679 to make %b simpler and working again.
683 Complete removal of libsysfs, replaced by simple helper functions
684 which are much simpler and a bit faster. The udev daemon operatesentirely
685 on event parameters and does not use sysfs for simple rules anymore.
686 Please report any new bugs/problems, that may be caused by this big
687 change. They will be fixed immediately.
689 The enumeration format character '%e' is deprecated and will be
690 removed sometimes from a future udev version. It never worked correctly
691 outside of udevstart, so we can't use it with the new parallel
692 coldplug. A simple enumeration is as useless as the devfs naming
693 scheme, just get rid of both if you still use it.
695 MODALIAS and $modalias is not needed and will be removed from one of
696 the next udev versions, replace it in all rules with ENV{MODALIAS} or
697 the sysfs "modalias" value.
699 Thanks a lot to Marco for all his help on finding and fixing bugs.
703 Let scsi_id request libata drive serial numbers from page 0x80.
705 Renamed etc/udev/persistent.rules to persistent-disk.rules and
706 added /dev/disk/by-name/* for device mapper device names.
708 Removed %e from the man page. It never worked reliably outside
709 of udevstart and udevstart is no longer recommended to use.
713 Symlinks are now exported to the event environment. Hopefully it's no
714 longer needed to run udevinfo from an event process, like it was
715 mentioned on the hotplug list:
716 UDEV [1134776873.702967] add@/block/sdb
719 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
723 Fix a problem if udevsend is used as the hotplug handler and tries to use
724 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
725 and this kind of problems will hopefully go away soon.
729 All built-in logic to work around bad sysfs timing is removed with this
730 version. The need to wait for sysfs files is almost fixed with a kernel
731 version that doesn't work with this udev version anyway. Until we fix
732 the timing of the "bus" link creation, the former integrated logic should
733 be emulated by a rule placed before all other rules:
734 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
736 The option "udev_db" does no longer exist. All udev state will be in
737 /$udev_root/.udev/ now, there is no longer an option to set this
739 If the init script or something else used this value, just depend on
740 this hardcoded path. But remember _all_content_ of this directory is
741 still private to udev and can change at any time.
743 Default location for rule sripts and helper programs is now: /lib/udev/.
744 Everything that is not useful on the commandline should go into this
745 directory. Some of the helpers in the extras folder are installed there
746 now. The rules need to be changed, to find the helpers there.
748 Also /lib/udev/devices is recommended as a directory where packages or
749 the user can place real device nodes, which get copied over to /dev at
750 every boot. This should replace the various solutions with custom config
753 Udevsend does no longer start the udev daemon. This must be done with
754 the init script that prepares /dev on tmpfs and creates the initial nodes,
755 before starting the daemon.
759 Silent a too verbose error logging for the old hotplug.d/ dev.d/
762 The copy of klibc is removed. A systemwide installed version of klibc
763 should be used to build a klibc udev now.
767 NAME="" will not create any nodes, but execute RUN keys. To completely
768 ignore an event the OPTION "ignore_device" should be used.
770 After removal of the reorder queue, events with a TIMEOUT can be executed
771 without any queuing now.
775 Fixed bug in udevd, if inotify is not available. We depend on netlink
776 uevents now, kernels without that event source will not work with that
777 version of udev anymore.
781 The rule parsing happens now in the daemon once at startup, all udev
782 event processes inherit the already parsed rules from the daemon.
783 It is shipped with SUSE10.0 and reduces heavily the system load at
784 startup. The option to save precompiled rules and let the udev process
785 pick the them up is removed, as it's no longer needed.
787 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
788 device. Libsysfs is changed to "translate" the requested link into the
789 real device path, as it would happen with the hotplug event. Otherwise
790 device removal and the udev database will not work.
792 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
795 A few improvements for vol_id, the filesytem probing code.
799 Fix a stupid typo in extras/run_directory for "make install".
801 scsi_id creates the temporary devnode now in /dev for usage with a
802 non-writable /tmp directory.
804 The uevent kernel socket buffer can carry app. 50.000 events now,
805 let's see who can break this again. :)
807 The upcoming kernel will have a new input driver core integration.
808 Some class devices are now symlinks to the real device. libsysfs
809 needs a fix for this to work correctly. Udevstart of older udev
810 versions will _not_ create these devices!
814 Fix a 'install' target in the Makefile, that prevents EXTRAS from
819 A bunch of mostly trivial bugfixes. From now on no node name or
820 symlink name can contain any character than plain whitelisted ascii
821 characters or validated utf8 byte-streams. This is needed for the
822 /dev/disk/by-label/* links, because we import untrusted data and
823 export it to the filesystem.
827 More bugfixes. If udevd was started from the kernel, we don't
828 have stdin/stdout/stderr, which broke the forked tools in some
833 Bugfix. udevstart event ordering was broken for a long time.
834 The new run_program() uncovered it, because /dev/null was not
835 available while we try to run external programs.
836 Now udevstart should create it before we run anything.
840 Minor bugfixes and some distro rules updates. If you don't have the
841 persistent disk rules in /dev/disk/by-*/* on your distro, just
842 grab it from here. :)
846 We can use socket communication now to pass events from udev to
848 RUN+="socket:/org/freedesktop/hal/udev_event"
849 will pass the whole udev event to the HAL daemon without the need
850 for a forked helper. (See ChangeLog for udevmonitor, as an example)
854 Mostly bugfixes and see ChangeLog.
856 The test for the existence of an environment value should be
858 ENV{KEY}=="*" to ENV{KEY}=="?*"
859 because "*" will not fail anymore, if the key does not exist or
864 Bugfixes and a few tweaks described in the ChangeLog.
868 Mostly a Bugfix release.
870 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
871 timing with custom rules.
875 We changed the internal rule storage format. Our large rule files took
876 2 MB of RAM, with the change we are down to 99kB.
878 If the device-node has been created with default name and no symlink or
879 options are to remenber, it is not longer stored in the udevdb. HAL will
880 need to be updated to work correctly with that change.
882 To overrride optimization flags, OPTFLAGS may be used now.
890 Major changes happened with this release. The goal is to take over the
891 complete kernel-event handling and provide a more efficient way to dispatch
892 kernel events. Replacing most of the current shell script logic and the
893 kernel forked helper with a netlink-daemon and a rule-based event handling.
895 o udevd listens to netlink events now. The first valid netlink event
896 will make udevd ignore any message from udevsend that contains a
897 SEQNUM, to avoid duplicate events. The forked events can be disabled
899 echo "" > /proc/sys/kernel/hotplug
900 For full support, the broken input-subsytem needs to be fixed, not to
901 bypass the driver core.
903 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
904 removed from udev itself and must be emulated by calling small
905 helper binaries provided in the extras folder:
906 make EXTRAS=extras/run_directory/
907 will build udev_run_devd and udev_run_hotplugd, which can be called
908 from a rule if needed:
909 RUN+="/sbin/udev_run_hotplugd"
910 The recommended way to handle this is to convert all the calls from
911 the directories to explicit udev rules and get completely rid of the
912 multiplexing. (To catch a ttyUSB event, you now no longer need to
913 fork and exit 300 tty script instances you are not interested in, it
914 is just one rule that matches exactly the device.)
916 o udev handles now _all_ events not just events for class and block
917 devices, this way it is possible to control the complete event
918 behavior with udev rules. Especially useful for rules like:
919 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
921 o As used in the modalias rule, udev supports now textual
922 substitution placeholder along with the usual format chars. This
923 needs to be documented, for now it's only visible in udev_rules_parse.c.
925 o The rule keys support now more operations. This is documented in the
926 man page. It is possible to add values to list-keys like the SYMLINK
927 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
928 Also "final"-assignments are supported by using KEY:="value", which will
929 prevent changing the key by any later rule.
931 o kernel 2.6.12 has the "detached_state" attribute removed from
932 sysfs, which was used to recognize sysfs population. We switched that
933 to wait for the "bus" link, which is only available in kernels after 2.6.11.
934 Running this udev version on older kernels may cause a short delay for
937 o To provide infrastructure for persistent device naming, the id programs:
938 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
939 to export the probed data in environment key format:
940 pim:~ # /sbin/ata_id --export /dev/hda
941 ID_MODEL=HTS726060M9AT00
942 ID_SERIAL=MRH401M4G6UM9B
946 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
947 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
950 kay@pim:~> tree /dev/disk
953 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
954 | `-- IBM-Memory_Key -> ../../sda
956 | |-- swap -> ../../hda1
957 | |-- date -> ../../sda1
958 | `-- home -> ../../hda3
960 |-- 2E08712B0870F2E7 -> ../../hda3
961 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
962 |-- E845-7A89 -> ../../sda1
963 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
965 The IMPORT= operation will import these keys in the environment and make
966 it available for later PROGRAM= and RUN= executed programs. The keys are
967 also stored in the udevdb and can be queried from there with one of the
970 o A few binaries are silently added to the repository, which can be used
971 to replay kernel events from initramfs instead of using coldplug. udevd
972 can be instructed now to queue-up events while the stored events from
973 initramfs are filled into the udevd-queue. This code is still under
974 development and there is no documentation now besides the code itself.
975 The additional binaries get compiled, but are not installed by default.
977 o There is also a temporary fix for a performance problem where too many
978 events happen in parallel and every event needs to parse the rules.
979 udev can now read precompiled rules stored on disk. This is likely to be
980 replaced by a more elegant solution in a future udev version.
984 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
985 Fix for libsysfs not to expect this file was added.
989 All rules are applied now, but only the first matching rule with a NAME-key
990 will be applied. All later rules with NAME-key are completely ignored. This
991 way system supplied symlinks or permissions gets applied to user-defined
995 Please check your rules setup, if you may need to add OPTIONS="last_rule"
996 to some rules, to keep the old behavior.
998 The rules are read on "remove"-events too. That makes is possible to match
999 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1000 instruct udev to ignore an event (OPTIONS="ignore_device").
1001 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1003 The new RUN-key supports rule-based execution of programs after device-node
1004 handling. This is meant as a general replacement for the dev.d/-directories
1005 to give fine grained control over the execution of programs.
1007 The %s{}-sysfs format char replacement values are searched at any of the
1008 devices in the device chain now, not only at the class-device.
1010 We support log priority levels now. The value udev_log in udev.conf is used
1011 to determine what is printed to syslog. This makes it possible to
1012 run a version with compiled-in debug messages in a production environment
1013 which is sometimes needed to find a bug.
1014 It is still possible to supress the inclusion of _any_ syslog usage with
1015 USE_LOG=false to create the smallest possible binaries if needed.
1016 The configured udev_log value can be overridden with the environment variable
1021 Possible use of a system-wide klibc:
1022 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1023 will link against an external klibc and our own version will be ignored.
1027 We support an unlimited count of symlinks now.
1029 If USE_STATIC=true is passed to a glibc build, we link statically and use
1030 a built-in userdb parser to resolve user and group names.
1032 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1033 we walk up the chain of physical devices to find a match.
1035 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1036 easy to skip certain attribute matches without composing rules with weird
1037 character class negations like:
1038 KERNEL="[!s][!c][!d]*"
1039 this can now be replaced with:
1041 The current simple '=' is still supported, and should work as it does today,
1042 but existing rules should be converted if possible, to be better readable.
1044 We have new ENV{}== key now, to match against a maximum of 5 environment
1047 udevstart is its own binary again, because we don't need co carry this araound
1048 with every forked event.
~ianmdlvl / elogind.git / blob