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 We are currently merging the Ubuntu rules in the udev default rules,
13 and get one step closer to provide a common Linux /dev setup regarding
14 device names, symlinks, and default device permissions. On udev startup,
15 we now expect the following groups to be resolvable to their ids by
17 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
19 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
20 which do not depend on the kernel device name. As usual, unique
21 devices - only a single one per product connected, or a real
22 USB serial number in the device - are always found with the same
23 name in the by-id/ directory.
24 Completely Identical devices may overwrite their names in by-id/
25 and can only be found reliably in the by-path/ directory. Devices
26 specified by by-path/ must not change their connection, like the
27 USB port number they are plugged in, to keep their name.
33 Fix for a possible segfault while swapping network interface names in udev
40 The group "video" is part of the default rules now.
44 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
45 block devices in some cases. No common distro uses this option anymore,
46 and we do not get enough testing for this and recent udev versions. If
47 this option is not needed to run some old distro with a new kernel,
48 it should be disabled in the kernel config.
50 Bugfix for the $links substitution variable, which may crash if no links
51 are created. This should not happen in usual setups because we always
52 create /dev/{block,char}/ links.
54 The strings of the parsed rules, which are kept in memory, no longer
55 contain duplicate entries, or duplicate tails of strings. This, and the
56 new rules parsing/matching code reduces the total in-memory size of
57 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
60 The export of DEVTYPE=disk/partition got removed from the default
61 rules. This value is available from the kernel. The pnp shell script
62 modprobe hack is removed from the default rules. ACPI devices have _proper_
63 modalias support and take care of the same functionality.
64 Installations which support old kernels, but install current default
65 udev rules may want to add that to the compat rules file.
67 Libvolume_id now always probes for all known filesystems, and does not
68 stop at the first match. Some filesystems are marked as "exclusive probe",
69 and if any other filesytem type matches at the same time, libvolume_id
70 will, by default, not return any probing result. This is intended to prevent
71 mis-detection with conflicting left-over signatures found from earlier
72 file system formats. That way, we no longer depend on the probe-order
73 in case of multiple competing signatures. In some setups the kernel allows
74 to mount a volume with just the old filesystem signature still in place.
75 This may damage the new filesystem and cause data-loss, just by mounting
76 it. Because volume_id can not decide which one the correct signature is,
77 the wrong signatures need to be removed manually from the volume, or the
78 volume needs to be reformatted, to enable filesystem detection and possible
83 Fix segfault if compiled without optimization and dbg() does not get
84 compiled out and uses variables which are not available.
88 Bugfixes. (And maybe new bugs. :))
90 The rule matching engine got converted from a rule list to a token
91 array which reduced the in-memory rules representation of a full
92 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
93 Limits like 5 ENV and ATTR matches, and one single instance for most
94 other keys per rule are gone.
96 The NAME assignment is no longer special cased. If later rules assign
97 a NAME value again, the former value will be overwritten. As usual
98 for most other keys, the NAME value can be protected by doing a final
99 assignment with NAME:="<value>".
101 All udev code now uses libudev, which is also exported. The library
102 is still under development, marked as experimental, and its interface
103 may change as long as the DeviceKit integration is not finished.
105 Many thanks to Alan Jenkins for his continuous help, and finding and
106 optimizing some of the computing expensive parts.
112 Kernel devices and device nodes are connected now by reverse indizes in
113 /sys and /dev. A device number retrieved by a stat() or similar, the
114 kernel device directory can be found by looking up:
115 /sys/dev/{block,char}/<maj>:<min>
116 and the device node of the same device by looking up:
117 /dev/{block,char}/<maj>:<min>
121 Fix recently introduced bug, which caused a compilation without large
122 file support, where vol_id does not recognize raid signatures at the end
125 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
126 Seems some kernel versions prevent the creation of the ieee-* links,
127 so people used the scsi-* link which disappeared now.
129 More libudev work. Almost all udevadm functionality comes from libudev
132 udevadm trigger has a new option --type, which allows to trigger events
133 for "devices", for "subsystems", or "failed" devices. The old option
134 --retry-failed" still works, but is no longer mentioned in the man page.
140 The udevadm info --device-id-of-file= output has changed to use
141 the obvious format. Possible current users should use the --export
142 option which is not affected.
144 The old udev commands symlinks to udevadm are not installed, if
145 these symlinks are used, a warning is printed.
151 Optical drive's media is no longer probed for raid signatures,
152 reading the end of the device causes some devices to malfunction.
153 Also the offset of the last session found is used now to probe
156 The volume_id library got a major version number update to 1,
157 some deprecated functions are removed.
159 A shared library "libudev" gets installed now to provide access
160 to udev device information. DeviceKit, the successor of HAL, will
161 need this library to access the udev database and search sysfs for
163 The library is currently in an experimental state, also the API is
164 expected to change, as long as the DeviceKit integration is not
169 We use ./configure now. See INSTALL for details. Current
172 "/usr" - prefix for man pages, include files
174 "" - the root filesystem, prefix for libs and binaries
178 "lib" - directory name for libraries, not a path name
179 multilib 64bit systems may use "lib64" instead of "lib"
181 compile-in verbose debug messages
183 disable all logging and compile-out all log strings
185 link against SELInux libraries, to set the expected context
188 In the default rules, the group "disk" gets permissions 0660 instead
189 of 0640. One small step closer to unify distro rules. Some day, all
190 distros hopefully end up with the same set of rules.
192 No symlinks to udevadm are installed anymore, if they are still needed,
193 they should be provided by the package.
199 Default udev rules, which are not supposed to be edited by the user, should
200 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
201 the udev package and will be replaced with an update. Udev will pick up rule
203 /lib/udev/rules.d/ - default installed rules
204 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
205 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
206 It does not matter in which directory a rule file lives, all files are sorted
209 To help creating /dev/root, we have now:
210 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
213 In case the current --device-id-of-file is already used, please switch to
214 the --export format version, it saves the output parsing and the old
215 format will be changed to use ':' as a separator, like the format in the
220 Fix cdrom_id to properly recognize blank media.
226 Tape drive id-data is queried from /dev/bsg/* instead of the tape
227 nodes. This avoids rewinding tapes on open().
233 The symlinks udevcontrol and udevtrigger are no longer installed by
236 The scsi_id program does not depend on sysfs anymore. It can speak
237 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
238 data, which should solve some old problems with tape devices, where
239 we better do not open all tape device nodes to identify the device.
245 The cdrom_id program is replaced by an advanced version, which can
246 detect most common device types, and also properties of the inserted
247 media. This is part of moving some basic functionality from HAL into
248 udev (and the kernel).
254 The last WAIT_FOR_SYSFS rule is removed from the default rules.
256 The symlinks to udevadm for the debugging tools: udevmonitor and
257 udevtest are no longer created.
259 The symlinks to the udevadm man page for the old tool names are
262 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
263 should be prefixed with '@' to indicate that the path is not a
274 Udevstart is removed from the tree, it did not get installed for
275 a long time now, and is long replaced by trigger and settle.
281 All udev tools are merged into a single binary called udevadm.
282 The old names of the tools are built-in commands in udevadm now.
283 Symlinks to udevadm, with the names of the old tools, provide
284 the same functionality as the standalone tools. There is also
285 only a single udevadm.8 man page left for all tools.
287 Tools like mkinitramfs should be checked, if they need to include
288 udevadm in the list of files.
298 The etc/udev/rules.d/ directory now contains a default set of basic
299 udev rules. This initial version is the result of a rules file merge
300 of Fedora and openSUSE. For these both distros only a few specific
301 rules are left in their own file, named after the distro. Rules which
302 are optionally installed, because they are only valid for a specific
303 architecture, or rules for subsystems which are not always used are
304 in etc/udev/packages/.
310 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
311 actions by dynamically created rules.
313 SYMLINK=="<value>" matches agains the entries in the list of
314 currently defined symlinks. The links are not created in the
315 filesystem at that point in time, but the values can be matched.
317 RUN{ignore_error}+="<program>" will ignore any exit code from the
318 program and not record as a failed event.
324 Final merge of patches/features from the Ubuntu package.
330 Control characters in filesystem label strings are no longer silenty
331 removed, but hex-encoded, to be able to uniquely identify the device
332 by its symlink in /dev/disk/by-label/.
333 If libvolume_id is used by mount(8), LABEL= will work as expected,
334 if slashes or other characters are used in the label string.
336 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
337 can be specified now. The TEST key accepts an optional mode mask
338 TEST{0100}=="<is executable file>".
340 Scsi_id now supports a mode without expecting scsi-specific sysfs
341 entries to allow the extraction of cciss-device persistent properties.
347 In the future, we may see uuid's which are just simple character
348 strings (see the DDF Raid Specification). For that reason vol_id now
349 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
350 the creation of symlinks, the *_SAFE values ensure, that no control
351 or whitespace characters are used in the filename.
353 Possible users of libvolume_id, please use the volume_id_get_* functions.
354 The public struct will go away in a future release of the library.
360 Removal of useless extras/eventrecorder.sh.
370 The directory multiplexer for dev.d/ and hotplug.d are finally removed
371 from the udev package.
377 Symlinks can have priorities now, the priority is assigned to the device
378 and specified with OPTIONS="link_priority=100". Devices with higher
379 priorities overwrite the symlinks of devices with lower priorities.
380 If the device that currently owns the link, goes away, the symlink
381 will be removed, and recreated, pointing to the next device with the
382 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
383 more reliable, if multiple devices contain the same metadata and overwrite
386 The dasd_id program is removed from the udev tree, and dasdinfo, with the
387 needed rules, are part of the s390-tools now.
389 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
390 we may get the scsi sysfs mess fixed some day, and this will only catch
391 the devices we are looking for.
393 USB serial numbers for storage devices have the target:lun now appended,
394 to make it possibble to distinguish broken multi-lun devices with all
395 the same SCSI identifiers.
397 Note: The extra "run_directory" which searches and executes stuff in
398 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
399 with the next release. Make sure, that you don't use it anymore, or
400 provides your own implementation of that inefficient stuff.
401 We are tired of reports about a "slow udev", because these directories
402 contain stuff, that runs with _every_ event, instead of using rules,
403 that run programs only for the matching events.
413 DRIVER== will match only for devices that actually have a real
414 driver. DRIVERS== must be used, if parent devices should be
415 included in the match.
417 Libvolume_id's "linux_raid" detection needed another fix.
425 Add additional check to volume_id detection of via_raid, cause
426 some company decided to put a matching pattern all over the empty
427 storage area of their music players.
431 Fix path_id for SAS devices.
435 The udev daemon can be started with --debug-trace now, which will
436 execute all events serialized to get a chance to catch a possible
437 action that crashes the box.
439 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
440 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
441 are excluded from the warning. Referencing parent attributes directly
442 may break when something in the kernel driver model changes. Udev will
443 just find the attribute by walking up the parent chain.
445 Udevtrigger now sorts the list of devices depending on the device
446 dependency, so a "usb" device is triggered after the parent "pci"
451 Revert persistent-storage ata-serial '_' '-' replacement.
457 Udevtrigger can now filter the list of devices to be triggered. Matches
458 for subsystems or sysfs attributes can be specified.
460 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
461 zero-sized files to avoid pointing to /sys and confuse broken tools which
462 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
465 The rules and scripts to create udev rules for persistent network
466 devices and optical drives are in the extras/rules_generator directory
467 now. If you use something similar, please consider replacing your own
468 version with this, to share the support effort. The rule_generator
469 installs its own rules into /etc/udev/rules.d.
471 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
472 the rule_generator depends on cdrom_id to be called in an earlier rule.
478 Renaming of some key names (the old names still work):
479 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
480 (The behavior of the key DRIVER will change soon in one of the next
481 releases, to match only the event device, please switch to DRIVERS
482 instead. If DRIVER is used, it will behave like DRIVERS, but an error
484 With the new key names, we have a more consistent and simpler scheme.
485 We can match the properties of the event device only, with: KERNEL,
486 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
487 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
488 longer mentioned in the man page and should be switched in the rule
491 ATTR{file}="value" can be used now, to write to a sysfs file of the
492 event device. Instead of:
493 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
495 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
497 All the PHYSDEV* keys are deprecated and will be removed from a
499 PHYDEVPATH - is the path of a parent device and should not be
501 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
502 matched with SUBSYSTEMS==
503 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
504 Newer kernels will have DRIVER in the environment,
505 for older kernels udev puts in. Class device will
506 no longer carry this property of a parent and
507 DRIVERS== can be used to match such a parent value.
508 Note that ENV{DRIVER} is only available for a few bus devices, where
509 the driver is already bound at device event time. On coldplug, the
510 events for a lot devices are already bound to a driver, and they will have
511 that value set. But on hotplug, at the time the kernel creates the device,
512 it can't know what driver may claim the device after that, therefore
513 in most cases it will be empty.
515 Failed events should now be re-triggered with:
516 udevtrigger --retry-failed.
517 Please switch to this command, so we keep the details of the /dev/.udev/failed/
518 files private to the udev tools. We may need to switch the current symlink
519 target, cause some obviously broken tools try to scan all files in /dev
520 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
521 million times. This takes ages on slow boxes.
523 The udevinfo attribute walk (-a) now works with giving a device node
524 name (-n) instead of a devpath (-p). The query now always works, also when
525 no database file was created by udev.
527 The built-in /etc/passwd /etc/group parser is removed, we always depend on
528 getpwnam() and getgrnam() now. One of the next releases will depend on
529 fnmatch() and may use getopt_long().
533 Bugfixes and small improvements.
537 Fix path_id for recent kernels.
543 Added support for swapping network interface names, by temporarily
544 renaming the device and wait for the target name to become free.
548 The built-in MODALIAS key and substitution is removed.
552 The binary firmware helper is replaced by the usual simple
553 shell script. Udevsend is removed from the tree.
561 Some more keys require the correct use of '==' and '=' depending
562 on the kind of operation beeing an assignment or a match. Rules
563 with invalid operations are skipped and logged to syslog. Please
564 test with udevtest if the parsing of your rules throws errors and
565 fix possibly broken rules.
569 Provide "udevsettle" to wait for all current udev events to finish.
570 It also watches the current kernel netlink queue by comparing the
571 even sequence number to make sure that there are no current pending
572 events that have not already arrived in the daemon.
576 Fix rule to skip persistent rules for removable IDE devices, which
577 also skipped optical IDE drives.
579 All *_id program are installed in /lib/udev/ by default now.
581 No binary is stripped anymore as this should be done in the
582 packaging process and not at build time.
584 libvolume_id is provided as a shared library now and vol_id is
585 linked against it. Also one of the next HAL versions will require
586 this library, and the HAL build process will also require the
587 header file to be installed. The copy of the same code in HAL will
588 be removed to have only a single copy left on the system.
592 Add persistent links for SCSI tapes. The rules file is renamed
593 to 60-persistent-storage.rules.
595 Create persistent path for usb devices. Can be used for all sorts
596 of devices that can't be distinguished by other properties like
597 multiple identical keyboards and mice connected to the same box.
599 Provide "udevtrigger" program to request events on coldplug. The
600 shell script is much too slow with thousends of devices.
604 Fix persistent disk rules to exclude removable IDE drives.
606 Warn if %e, $modalias or MODALIAS is used.
610 Fix queue export, which wasn't correct for subsequent add/remove
611 events for the same device.
615 Fix cramfs detection on big endian.
617 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
622 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
623 attributes were only checked at the parent device that matched the
624 by BUS requested subsystem. Fix it to also look at the device we
625 received the event for.
627 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
632 Fix a bug where NAME="" would prevent RUN from beeing executed.
634 RUN="/bin/program" does not longer automatically add the subsystem
635 as the first parameter. This is from the days of /sbin/hotplug
636 which is dead now and it's just confusing to need to add a space at
637 the end of the program name to prevent this.
638 If you use rules that need the subsystem as the first parameter,
639 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
640 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
644 The udev man page has moved to udev(7) as it does not describe a command
645 anymore. The programs udev, udevstart and udevsend are no longer installed
646 by default and must be copied manually, if they should be installed or
647 included in a package.
649 Fix a bug where "ignore_device" could run earlier collected RUN keys before
650 the ignore rule was applied.
652 More preparation for future sysfs changes. usb_id and scsi_id no longer
653 depend on a magic order of devices in the /devices chain. Specific devices
654 should be requested by their subsytem.
656 This will always find the scsi parent device without depending on a specific
658 dev = sysfs_device_get(devpath);
659 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
661 The "device" link in the current sysfs layout will be automatically
662 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
663 parent in the devpath. If a device is requested by it's symlink, like all
664 class devices in the new sysfs layout will look like, it gets automatically
665 resolved and substituted with the real devpath and not the symlink path.
668 A similar logic must be applied to _all_ sysfs users, including
669 scripts, that search along parent devices in sysfs. The explicit use of
670 the "device" link must be avoided. With the future sysfs layout all
671 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
672 back to the "class" or the "bus". The layout of the parent devices in
673 /devices is not necessarily expected to be stable across kernel releases and
674 searching for parents by their subsystem should make sysfs users tolerant
675 for changed parent chains.
679 Prepare udev to work with the experimental kernel patch, that moves
680 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
682 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
683 moving the class devices to /sys/devices.
685 Thanks again to Marco for help finding a hopefully nice compromise
686 to make %b simpler and working again.
690 Complete removal of libsysfs, replaced by simple helper functions
691 which are much simpler and a bit faster. The udev daemon operatesentirely
692 on event parameters and does not use sysfs for simple rules anymore.
693 Please report any new bugs/problems, that may be caused by this big
694 change. They will be fixed immediately.
696 The enumeration format character '%e' is deprecated and will be
697 removed sometimes from a future udev version. It never worked correctly
698 outside of udevstart, so we can't use it with the new parallel
699 coldplug. A simple enumeration is as useless as the devfs naming
700 scheme, just get rid of both if you still use it.
702 MODALIAS and $modalias is not needed and will be removed from one of
703 the next udev versions, replace it in all rules with ENV{MODALIAS} or
704 the sysfs "modalias" value.
706 Thanks a lot to Marco for all his help on finding and fixing bugs.
710 Let scsi_id request libata drive serial numbers from page 0x80.
712 Renamed etc/udev/persistent.rules to persistent-disk.rules and
713 added /dev/disk/by-name/* for device mapper device names.
715 Removed %e from the man page. It never worked reliably outside
716 of udevstart and udevstart is no longer recommended to use.
720 Symlinks are now exported to the event environment. Hopefully it's no
721 longer needed to run udevinfo from an event process, like it was
722 mentioned on the hotplug list:
723 UDEV [1134776873.702967] add@/block/sdb
726 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
730 Fix a problem if udevsend is used as the hotplug handler and tries to use
731 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
732 and this kind of problems will hopefully go away soon.
736 All built-in logic to work around bad sysfs timing is removed with this
737 version. The need to wait for sysfs files is almost fixed with a kernel
738 version that doesn't work with this udev version anyway. Until we fix
739 the timing of the "bus" link creation, the former integrated logic should
740 be emulated by a rule placed before all other rules:
741 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
743 The option "udev_db" does no longer exist. All udev state will be in
744 /$udev_root/.udev/ now, there is no longer an option to set this
746 If the init script or something else used this value, just depend on
747 this hardcoded path. But remember _all_content_ of this directory is
748 still private to udev and can change at any time.
750 Default location for rule sripts and helper programs is now: /lib/udev/.
751 Everything that is not useful on the commandline should go into this
752 directory. Some of the helpers in the extras folder are installed there
753 now. The rules need to be changed, to find the helpers there.
755 Also /lib/udev/devices is recommended as a directory where packages or
756 the user can place real device nodes, which get copied over to /dev at
757 every boot. This should replace the various solutions with custom config
760 Udevsend does no longer start the udev daemon. This must be done with
761 the init script that prepares /dev on tmpfs and creates the initial nodes,
762 before starting the daemon.
766 Silent a too verbose error logging for the old hotplug.d/ dev.d/
769 The copy of klibc is removed. A systemwide installed version of klibc
770 should be used to build a klibc udev now.
774 NAME="" will not create any nodes, but execute RUN keys. To completely
775 ignore an event the OPTION "ignore_device" should be used.
777 After removal of the reorder queue, events with a TIMEOUT can be executed
778 without any queuing now.
782 Fixed bug in udevd, if inotify is not available. We depend on netlink
783 uevents now, kernels without that event source will not work with that
784 version of udev anymore.
788 The rule parsing happens now in the daemon once at startup, all udev
789 event processes inherit the already parsed rules from the daemon.
790 It is shipped with SUSE10.0 and reduces heavily the system load at
791 startup. The option to save precompiled rules and let the udev process
792 pick the them up is removed, as it's no longer needed.
794 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
795 device. Libsysfs is changed to "translate" the requested link into the
796 real device path, as it would happen with the hotplug event. Otherwise
797 device removal and the udev database will not work.
799 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
802 A few improvements for vol_id, the filesytem probing code.
806 Fix a stupid typo in extras/run_directory for "make install".
808 scsi_id creates the temporary devnode now in /dev for usage with a
809 non-writable /tmp directory.
811 The uevent kernel socket buffer can carry app. 50.000 events now,
812 let's see who can break this again. :)
814 The upcoming kernel will have a new input driver core integration.
815 Some class devices are now symlinks to the real device. libsysfs
816 needs a fix for this to work correctly. Udevstart of older udev
817 versions will _not_ create these devices!
821 Fix a 'install' target in the Makefile, that prevents EXTRAS from
826 A bunch of mostly trivial bugfixes. From now on no node name or
827 symlink name can contain any character than plain whitelisted ascii
828 characters or validated utf8 byte-streams. This is needed for the
829 /dev/disk/by-label/* links, because we import untrusted data and
830 export it to the filesystem.
834 More bugfixes. If udevd was started from the kernel, we don't
835 have stdin/stdout/stderr, which broke the forked tools in some
840 Bugfix. udevstart event ordering was broken for a long time.
841 The new run_program() uncovered it, because /dev/null was not
842 available while we try to run external programs.
843 Now udevstart should create it before we run anything.
847 Minor bugfixes and some distro rules updates. If you don't have the
848 persistent disk rules in /dev/disk/by-*/* on your distro, just
849 grab it from here. :)
853 We can use socket communication now to pass events from udev to
855 RUN+="socket:/org/freedesktop/hal/udev_event"
856 will pass the whole udev event to the HAL daemon without the need
857 for a forked helper. (See ChangeLog for udevmonitor, as an example)
861 Mostly bugfixes and see ChangeLog.
863 The test for the existence of an environment value should be
865 ENV{KEY}=="*" to ENV{KEY}=="?*"
866 because "*" will not fail anymore, if the key does not exist or
871 Bugfixes and a few tweaks described in the ChangeLog.
875 Mostly a Bugfix release.
877 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
878 timing with custom rules.
882 We changed the internal rule storage format. Our large rule files took
883 2 MB of RAM, with the change we are down to 99kB.
885 If the device-node has been created with default name and no symlink or
886 options are to remenber, it is not longer stored in the udevdb. HAL will
887 need to be updated to work correctly with that change.
889 To overrride optimization flags, OPTFLAGS may be used now.
897 Major changes happened with this release. The goal is to take over the
898 complete kernel-event handling and provide a more efficient way to dispatch
899 kernel events. Replacing most of the current shell script logic and the
900 kernel forked helper with a netlink-daemon and a rule-based event handling.
902 o udevd listens to netlink events now. The first valid netlink event
903 will make udevd ignore any message from udevsend that contains a
904 SEQNUM, to avoid duplicate events. The forked events can be disabled
906 echo "" > /proc/sys/kernel/hotplug
907 For full support, the broken input-subsytem needs to be fixed, not to
908 bypass the driver core.
910 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
911 removed from udev itself and must be emulated by calling small
912 helper binaries provided in the extras folder:
913 make EXTRAS=extras/run_directory/
914 will build udev_run_devd and udev_run_hotplugd, which can be called
915 from a rule if needed:
916 RUN+="/sbin/udev_run_hotplugd"
917 The recommended way to handle this is to convert all the calls from
918 the directories to explicit udev rules and get completely rid of the
919 multiplexing. (To catch a ttyUSB event, you now no longer need to
920 fork and exit 300 tty script instances you are not interested in, it
921 is just one rule that matches exactly the device.)
923 o udev handles now _all_ events not just events for class and block
924 devices, this way it is possible to control the complete event
925 behavior with udev rules. Especially useful for rules like:
926 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
928 o As used in the modalias rule, udev supports now textual
929 substitution placeholder along with the usual format chars. This
930 needs to be documented, for now it's only visible in udev_rules_parse.c.
932 o The rule keys support now more operations. This is documented in the
933 man page. It is possible to add values to list-keys like the SYMLINK
934 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
935 Also "final"-assignments are supported by using KEY:="value", which will
936 prevent changing the key by any later rule.
938 o kernel 2.6.12 has the "detached_state" attribute removed from
939 sysfs, which was used to recognize sysfs population. We switched that
940 to wait for the "bus" link, which is only available in kernels after 2.6.11.
941 Running this udev version on older kernels may cause a short delay for
944 o To provide infrastructure for persistent device naming, the id programs:
945 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
946 to export the probed data in environment key format:
947 pim:~ # /sbin/ata_id --export /dev/hda
948 ID_MODEL=HTS726060M9AT00
949 ID_SERIAL=MRH401M4G6UM9B
953 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
954 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
957 kay@pim:~> tree /dev/disk
960 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
961 | `-- IBM-Memory_Key -> ../../sda
963 | |-- swap -> ../../hda1
964 | |-- date -> ../../sda1
965 | `-- home -> ../../hda3
967 |-- 2E08712B0870F2E7 -> ../../hda3
968 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
969 |-- E845-7A89 -> ../../sda1
970 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
972 The IMPORT= operation will import these keys in the environment and make
973 it available for later PROGRAM= and RUN= executed programs. The keys are
974 also stored in the udevdb and can be queried from there with one of the
977 o A few binaries are silently added to the repository, which can be used
978 to replay kernel events from initramfs instead of using coldplug. udevd
979 can be instructed now to queue-up events while the stored events from
980 initramfs are filled into the udevd-queue. This code is still under
981 development and there is no documentation now besides the code itself.
982 The additional binaries get compiled, but are not installed by default.
984 o There is also a temporary fix for a performance problem where too many
985 events happen in parallel and every event needs to parse the rules.
986 udev can now read precompiled rules stored on disk. This is likely to be
987 replaced by a more elegant solution in a future udev version.
991 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
992 Fix for libsysfs not to expect this file was added.
996 All rules are applied now, but only the first matching rule with a NAME-key
997 will be applied. All later rules with NAME-key are completely ignored. This
998 way system supplied symlinks or permissions gets applied to user-defined
1002 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1003 to some rules, to keep the old behavior.
1005 The rules are read on "remove"-events too. That makes is possible to match
1006 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1007 instruct udev to ignore an event (OPTIONS="ignore_device").
1008 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1010 The new RUN-key supports rule-based execution of programs after device-node
1011 handling. This is meant as a general replacement for the dev.d/-directories
1012 to give fine grained control over the execution of programs.
1014 The %s{}-sysfs format char replacement values are searched at any of the
1015 devices in the device chain now, not only at the class-device.
1017 We support log priority levels now. The value udev_log in udev.conf is used
1018 to determine what is printed to syslog. This makes it possible to
1019 run a version with compiled-in debug messages in a production environment
1020 which is sometimes needed to find a bug.
1021 It is still possible to supress the inclusion of _any_ syslog usage with
1022 USE_LOG=false to create the smallest possible binaries if needed.
1023 The configured udev_log value can be overridden with the environment variable
1028 Possible use of a system-wide klibc:
1029 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1030 will link against an external klibc and our own version will be ignored.
1034 We support an unlimited count of symlinks now.
1036 If USE_STATIC=true is passed to a glibc build, we link statically and use
1037 a built-in userdb parser to resolve user and group names.
1039 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1040 we walk up the chain of physical devices to find a match.
1042 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1043 easy to skip certain attribute matches without composing rules with weird
1044 character class negations like:
1045 KERNEL="[!s][!c][!d]*"
1046 this can now be replaced with:
1048 The current simple '=' is still supported, and should work as it does today,
1049 but existing rules should be converted if possible, to be better readable.
1051 We have new ENV{}== key now, to match against a maximum of 5 environment
1054 udevstart is its own binary again, because we don't need co carry this araound
1055 with every forked event.
~ianmdlvl / elogind.git / blob