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, and
13 get one step closer to provide a common Linux /dev setup regarding device
14 names, symlinks, and default device permissions. On udev startup, we now
15 expect the following groups to be resolvable to their ids by glibc's
16 getgrnam(): "disk cdrom floppy tape audio video lp tty kmem".
18 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
19 which do not depend on the kernel device name. As usual, unique
20 devices - only a single one per product connected, or a real
21 USB serial number in the device - are always found with the same
22 name in the by-id/ directory.
23 Completely Identical devices may overwrite their names in by-id/
24 and can only be found reliably in the by-path/ directory. Devices
25 specified by by-path/ must not change their connection, like the
26 USB port number they are plugged in, to keep their name.
32 Fix for a possible segfault while swapping network interface names in udev
39 The group "video" is part of the default rules now.
43 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
44 block devices in some cases. No common distro uses this option anymore,
45 and we do not get enough testing for this and recent udev versions. If
46 this option is not needed to run some old distro with a new kernel,
47 it should be disabled in the kernel config.
49 Bugfix for the $links substitution variable, which may crash if no links
50 are created. This should not happen in usual setups because we always
51 create /dev/{block,char}/ links.
53 The strings of the parsed rules, which are kept in memory, no longer
54 contain duplicate entries, or duplicate tails of strings. This, and the
55 new rules parsing/matching code reduces the total in-memory size of
56 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
59 The export of DEVTYPE=disk/partition got removed from the default
60 rules. This value is available from the kernel. The pnp shell script
61 modprobe hack is removed from the default rules. ACPI devices have _proper_
62 modalias support and take care of the same functionality.
63 Installations which support old kernels, but install current default
64 udev rules may want to add that to the compat rules file.
66 Libvolume_id now always probes for all known filesystems, and does not
67 stop at the first match. Some filesystems are marked as "exclusive probe",
68 and if any other filesytem type matches at the same time, libvolume_id
69 will, by default, not return any probing result. This is intended to prevent
70 mis-detection with conflicting left-over signatures found from earlier
71 file system formats. That way, we no longer depend on the probe-order
72 in case of multiple competing signatures. In some setups the kernel allows
73 to mount a volume with just the old filesystem signature still in place.
74 This may damage the new filesystem and cause data-loss, just by mounting
75 it. Because volume_id can not decide which one the correct signature is,
76 the wrong signatures need to be removed manually from the volume, or the
77 volume needs to be reformatted, to enable filesystem detection and possible
82 Fix segfault if compiled without optimization and dbg() does not get
83 compiled out and uses variables which are not available.
87 Bugfixes. (And maybe new bugs. :))
89 The rule matching engine got converted from a rule list to a token
90 array which reduced the in-memory rules representation of a full
91 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
92 Limits like 5 ENV and ATTR matches, and one single instance for most
93 other keys per rule are gone.
95 The NAME assignment is no longer special cased. If later rules assign
96 a NAME value again, the former value will be overwritten. As usual
97 for most other keys, the NAME value can be protected by doing a final
98 assignment with NAME:="<value>".
100 All udev code now uses libudev, which is also exported. The library
101 is still under development, marked as experimental, and its interface
102 may change as long as the DeviceKit integration is not finished.
104 Many thanks to Alan Jenkins for his continuous help, and finding and
105 optimizing some of the computing expensive parts.
111 Kernel devices and device nodes are connected now by reverse indizes in
112 /sys and /dev. A device number retrieved by a stat() or similar, the
113 kernel device directory can be found by looking up:
114 /sys/dev/{block,char}/<maj>:<min>
115 and the device node of the same device by looking up:
116 /dev/{block,char}/<maj>:<min>
120 Fix recently introduced bug, which caused a compilation without large
121 file support, where vol_id does not recognize raid signatures at the end
124 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
125 Seems some kernel versions prevent the creation of the ieee-* links,
126 so people used the scsi-* link which disappeared now.
128 More libudev work. Almost all udevadm functionality comes from libudev
131 udevadm trigger has a new option --type, which allows to trigger events
132 for "devices", for "subsystems", or "failed" devices. The old option
133 --retry-failed" still works, but is no longer mentioned in the man page.
139 The udevadm info --device-id-of-file= output has changed to use
140 the obvious format. Possible current users should use the --export
141 option which is not affected.
143 The old udev commands symlinks to udevadm are not installed, if
144 these symlinks are used, a warning is printed.
150 Optical drive's media is no longer probed for raid signatures,
151 reading the end of the device causes some devices to malfunction.
152 Also the offset of the last session found is used now to probe
155 The volume_id library got a major version number update to 1,
156 some deprecated functions are removed.
158 A shared library "libudev" gets installed now to provide access
159 to udev device information. DeviceKit, the successor of HAL, will
160 need this library to access the udev database and search sysfs for
162 The library is currently in an experimental state, also the API is
163 expected to change, as long as the DeviceKit integration is not
168 We use ./configure now. See INSTALL for details. Current
171 "/usr" - prefix for man pages, include files
173 "" - the root filesystem, prefix for libs and binaries
177 "lib" - directory name for libraries, not a path name
178 multilib 64bit systems may use "lib64" instead of "lib"
180 compile-in verbose debug messages
182 disable all logging and compile-out all log strings
184 link against SELInux libraries, to set the expected context
187 In the default rules, the group "disk" gets permissions 0660 instead
188 of 0640. One small step closer to unify distro rules. Some day, all
189 distros hopefully end up with the same set of rules.
191 No symlinks to udevadm are installed anymore, if they are still needed,
192 they should be provided by the package.
198 Default udev rules, which are not supposed to be edited by the user, should
199 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
200 the udev package and will be replaced with an update. Udev will pick up rule
202 /lib/udev/rules.d/ - default installed rules
203 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
204 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
205 It does not matter in which directory a rule file lives, all files are sorted
208 To help creating /dev/root, we have now:
209 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
212 In case the current --device-id-of-file is already used, please switch to
213 the --export format version, it saves the output parsing and the old
214 format will be changed to use ':' as a separator, like the format in the
219 Fix cdrom_id to properly recognize blank media.
225 Tape drive id-data is queried from /dev/bsg/* instead of the tape
226 nodes. This avoids rewinding tapes on open().
232 The symlinks udevcontrol and udevtrigger are no longer installed by
235 The scsi_id program does not depend on sysfs anymore. It can speak
236 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
237 data, which should solve some old problems with tape devices, where
238 we better do not open all tape device nodes to identify the device.
244 The cdrom_id program is replaced by an advanced version, which can
245 detect most common device types, and also properties of the inserted
246 media. This is part of moving some basic functionality from HAL into
247 udev (and the kernel).
253 The last WAIT_FOR_SYSFS rule is removed from the default rules.
255 The symlinks to udevadm for the debugging tools: udevmonitor and
256 udevtest are no longer created.
258 The symlinks to the udevadm man page for the old tool names are
261 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
262 should be prefixed with '@' to indicate that the path is not a
273 Udevstart is removed from the tree, it did not get installed for
274 a long time now, and is long replaced by trigger and settle.
280 All udev tools are merged into a single binary called udevadm.
281 The old names of the tools are built-in commands in udevadm now.
282 Symlinks to udevadm, with the names of the old tools, provide
283 the same functionality as the standalone tools. There is also
284 only a single udevadm.8 man page left for all tools.
286 Tools like mkinitramfs should be checked, if they need to include
287 udevadm in the list of files.
297 The etc/udev/rules.d/ directory now contains a default set of basic
298 udev rules. This initial version is the result of a rules file merge
299 of Fedora and openSUSE. For these both distros only a few specific
300 rules are left in their own file, named after the distro. Rules which
301 are optionally installed, because they are only valid for a specific
302 architecture, or rules for subsystems which are not always used are
303 in etc/udev/packages/.
309 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
310 actions by dynamically created rules.
312 SYMLINK=="<value>" matches agains the entries in the list of
313 currently defined symlinks. The links are not created in the
314 filesystem at that point in time, but the values can be matched.
316 RUN{ignore_error}+="<program>" will ignore any exit code from the
317 program and not record as a failed event.
323 Final merge of patches/features from the Ubuntu package.
329 Control characters in filesystem label strings are no longer silenty
330 removed, but hex-encoded, to be able to uniquely identify the device
331 by its symlink in /dev/disk/by-label/.
332 If libvolume_id is used by mount(8), LABEL= will work as expected,
333 if slashes or other characters are used in the label string.
335 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
336 can be specified now. The TEST key accepts an optional mode mask
337 TEST{0100}=="<is executable file>".
339 Scsi_id now supports a mode without expecting scsi-specific sysfs
340 entries to allow the extraction of cciss-device persistent properties.
346 In the future, we may see uuid's which are just simple character
347 strings (see the DDF Raid Specification). For that reason vol_id now
348 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
349 the creation of symlinks, the *_SAFE values ensure, that no control
350 or whitespace characters are used in the filename.
352 Possible users of libvolume_id, please use the volume_id_get_* functions.
353 The public struct will go away in a future release of the library.
359 Removal of useless extras/eventrecorder.sh.
369 The directory multiplexer for dev.d/ and hotplug.d are finally removed
370 from the udev package.
376 Symlinks can have priorities now, the priority is assigned to the device
377 and specified with OPTIONS="link_priority=100". Devices with higher
378 priorities overwrite the symlinks of devices with lower priorities.
379 If the device that currently owns the link, goes away, the symlink
380 will be removed, and recreated, pointing to the next device with the
381 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
382 more reliable, if multiple devices contain the same metadata and overwrite
385 The dasd_id program is removed from the udev tree, and dasdinfo, with the
386 needed rules, are part of the s390-tools now.
388 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
389 we may get the scsi sysfs mess fixed some day, and this will only catch
390 the devices we are looking for.
392 USB serial numbers for storage devices have the target:lun now appended,
393 to make it possibble to distinguish broken multi-lun devices with all
394 the same SCSI identifiers.
396 Note: The extra "run_directory" which searches and executes stuff in
397 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
398 with the next release. Make sure, that you don't use it anymore, or
399 provides your own implementation of that inefficient stuff.
400 We are tired of reports about a "slow udev", because these directories
401 contain stuff, that runs with _every_ event, instead of using rules,
402 that run programs only for the matching events.
412 DRIVER== will match only for devices that actually have a real
413 driver. DRIVERS== must be used, if parent devices should be
414 included in the match.
416 Libvolume_id's "linux_raid" detection needed another fix.
424 Add additional check to volume_id detection of via_raid, cause
425 some company decided to put a matching pattern all over the empty
426 storage area of their music players.
430 Fix path_id for SAS devices.
434 The udev daemon can be started with --debug-trace now, which will
435 execute all events serialized to get a chance to catch a possible
436 action that crashes the box.
438 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
439 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
440 are excluded from the warning. Referencing parent attributes directly
441 may break when something in the kernel driver model changes. Udev will
442 just find the attribute by walking up the parent chain.
444 Udevtrigger now sorts the list of devices depending on the device
445 dependency, so a "usb" device is triggered after the parent "pci"
450 Revert persistent-storage ata-serial '_' '-' replacement.
456 Udevtrigger can now filter the list of devices to be triggered. Matches
457 for subsystems or sysfs attributes can be specified.
459 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
460 zero-sized files to avoid pointing to /sys and confuse broken tools which
461 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
464 The rules and scripts to create udev rules for persistent network
465 devices and optical drives are in the extras/rules_generator directory
466 now. If you use something similar, please consider replacing your own
467 version with this, to share the support effort. The rule_generator
468 installs its own rules into /etc/udev/rules.d.
470 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
471 the rule_generator depends on cdrom_id to be called in an earlier rule.
477 Renaming of some key names (the old names still work):
478 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
479 (The behavior of the key DRIVER will change soon in one of the next
480 releases, to match only the event device, please switch to DRIVERS
481 instead. If DRIVER is used, it will behave like DRIVERS, but an error
483 With the new key names, we have a more consistent and simpler scheme.
484 We can match the properties of the event device only, with: KERNEL,
485 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
486 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
487 longer mentioned in the man page and should be switched in the rule
490 ATTR{file}="value" can be used now, to write to a sysfs file of the
491 event device. Instead of:
492 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
494 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
496 All the PHYSDEV* keys are deprecated and will be removed from a
498 PHYDEVPATH - is the path of a parent device and should not be
500 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
501 matched with SUBSYSTEMS==
502 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
503 Newer kernels will have DRIVER in the environment,
504 for older kernels udev puts in. Class device will
505 no longer carry this property of a parent and
506 DRIVERS== can be used to match such a parent value.
507 Note that ENV{DRIVER} is only available for a few bus devices, where
508 the driver is already bound at device event time. On coldplug, the
509 events for a lot devices are already bound to a driver, and they will have
510 that value set. But on hotplug, at the time the kernel creates the device,
511 it can't know what driver may claim the device after that, therefore
512 in most cases it will be empty.
514 Failed events should now be re-triggered with:
515 udevtrigger --retry-failed.
516 Please switch to this command, so we keep the details of the /dev/.udev/failed/
517 files private to the udev tools. We may need to switch the current symlink
518 target, cause some obviously broken tools try to scan all files in /dev
519 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
520 million times. This takes ages on slow boxes.
522 The udevinfo attribute walk (-a) now works with giving a device node
523 name (-n) instead of a devpath (-p). The query now always works, also when
524 no database file was created by udev.
526 The built-in /etc/passwd /etc/group parser is removed, we always depend on
527 getpwnam() and getgrnam() now. One of the next releases will depend on
528 fnmatch() and may use getopt_long().
532 Bugfixes and small improvements.
536 Fix path_id for recent kernels.
542 Added support for swapping network interface names, by temporarily
543 renaming the device and wait for the target name to become free.
547 The built-in MODALIAS key and substitution is removed.
551 The binary firmware helper is replaced by the usual simple
552 shell script. Udevsend is removed from the tree.
560 Some more keys require the correct use of '==' and '=' depending
561 on the kind of operation beeing an assignment or a match. Rules
562 with invalid operations are skipped and logged to syslog. Please
563 test with udevtest if the parsing of your rules throws errors and
564 fix possibly broken rules.
568 Provide "udevsettle" to wait for all current udev events to finish.
569 It also watches the current kernel netlink queue by comparing the
570 even sequence number to make sure that there are no current pending
571 events that have not already arrived in the daemon.
575 Fix rule to skip persistent rules for removable IDE devices, which
576 also skipped optical IDE drives.
578 All *_id program are installed in /lib/udev/ by default now.
580 No binary is stripped anymore as this should be done in the
581 packaging process and not at build time.
583 libvolume_id is provided as a shared library now and vol_id is
584 linked against it. Also one of the next HAL versions will require
585 this library, and the HAL build process will also require the
586 header file to be installed. The copy of the same code in HAL will
587 be removed to have only a single copy left on the system.
591 Add persistent links for SCSI tapes. The rules file is renamed
592 to 60-persistent-storage.rules.
594 Create persistent path for usb devices. Can be used for all sorts
595 of devices that can't be distinguished by other properties like
596 multiple identical keyboards and mice connected to the same box.
598 Provide "udevtrigger" program to request events on coldplug. The
599 shell script is much too slow with thousends of devices.
603 Fix persistent disk rules to exclude removable IDE drives.
605 Warn if %e, $modalias or MODALIAS is used.
609 Fix queue export, which wasn't correct for subsequent add/remove
610 events for the same device.
614 Fix cramfs detection on big endian.
616 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
621 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
622 attributes were only checked at the parent device that matched the
623 by BUS requested subsystem. Fix it to also look at the device we
624 received the event for.
626 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
631 Fix a bug where NAME="" would prevent RUN from beeing executed.
633 RUN="/bin/program" does not longer automatically add the subsystem
634 as the first parameter. This is from the days of /sbin/hotplug
635 which is dead now and it's just confusing to need to add a space at
636 the end of the program name to prevent this.
637 If you use rules that need the subsystem as the first parameter,
638 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
639 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
643 The udev man page has moved to udev(7) as it does not describe a command
644 anymore. The programs udev, udevstart and udevsend are no longer installed
645 by default and must be copied manually, if they should be installed or
646 included in a package.
648 Fix a bug where "ignore_device" could run earlier collected RUN keys before
649 the ignore rule was applied.
651 More preparation for future sysfs changes. usb_id and scsi_id no longer
652 depend on a magic order of devices in the /devices chain. Specific devices
653 should be requested by their subsytem.
655 This will always find the scsi parent device without depending on a specific
657 dev = sysfs_device_get(devpath);
658 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
660 The "device" link in the current sysfs layout will be automatically
661 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
662 parent in the devpath. If a device is requested by it's symlink, like all
663 class devices in the new sysfs layout will look like, it gets automatically
664 resolved and substituted with the real devpath and not the symlink path.
667 A similar logic must be applied to _all_ sysfs users, including
668 scripts, that search along parent devices in sysfs. The explicit use of
669 the "device" link must be avoided. With the future sysfs layout all
670 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
671 back to the "class" or the "bus". The layout of the parent devices in
672 /devices is not necessarily expected to be stable across kernel releases and
673 searching for parents by their subsystem should make sysfs users tolerant
674 for changed parent chains.
678 Prepare udev to work with the experimental kernel patch, that moves
679 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
681 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
682 moving the class devices to /sys/devices.
684 Thanks again to Marco for help finding a hopefully nice compromise
685 to make %b simpler and working again.
689 Complete removal of libsysfs, replaced by simple helper functions
690 which are much simpler and a bit faster. The udev daemon operatesentirely
691 on event parameters and does not use sysfs for simple rules anymore.
692 Please report any new bugs/problems, that may be caused by this big
693 change. They will be fixed immediately.
695 The enumeration format character '%e' is deprecated and will be
696 removed sometimes from a future udev version. It never worked correctly
697 outside of udevstart, so we can't use it with the new parallel
698 coldplug. A simple enumeration is as useless as the devfs naming
699 scheme, just get rid of both if you still use it.
701 MODALIAS and $modalias is not needed and will be removed from one of
702 the next udev versions, replace it in all rules with ENV{MODALIAS} or
703 the sysfs "modalias" value.
705 Thanks a lot to Marco for all his help on finding and fixing bugs.
709 Let scsi_id request libata drive serial numbers from page 0x80.
711 Renamed etc/udev/persistent.rules to persistent-disk.rules and
712 added /dev/disk/by-name/* for device mapper device names.
714 Removed %e from the man page. It never worked reliably outside
715 of udevstart and udevstart is no longer recommended to use.
719 Symlinks are now exported to the event environment. Hopefully it's no
720 longer needed to run udevinfo from an event process, like it was
721 mentioned on the hotplug list:
722 UDEV [1134776873.702967] add@/block/sdb
725 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
729 Fix a problem if udevsend is used as the hotplug handler and tries to use
730 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
731 and this kind of problems will hopefully go away soon.
735 All built-in logic to work around bad sysfs timing is removed with this
736 version. The need to wait for sysfs files is almost fixed with a kernel
737 version that doesn't work with this udev version anyway. Until we fix
738 the timing of the "bus" link creation, the former integrated logic should
739 be emulated by a rule placed before all other rules:
740 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
742 The option "udev_db" does no longer exist. All udev state will be in
743 /$udev_root/.udev/ now, there is no longer an option to set this
745 If the init script or something else used this value, just depend on
746 this hardcoded path. But remember _all_content_ of this directory is
747 still private to udev and can change at any time.
749 Default location for rule sripts and helper programs is now: /lib/udev/.
750 Everything that is not useful on the commandline should go into this
751 directory. Some of the helpers in the extras folder are installed there
752 now. The rules need to be changed, to find the helpers there.
754 Also /lib/udev/devices is recommended as a directory where packages or
755 the user can place real device nodes, which get copied over to /dev at
756 every boot. This should replace the various solutions with custom config
759 Udevsend does no longer start the udev daemon. This must be done with
760 the init script that prepares /dev on tmpfs and creates the initial nodes,
761 before starting the daemon.
765 Silent a too verbose error logging for the old hotplug.d/ dev.d/
768 The copy of klibc is removed. A systemwide installed version of klibc
769 should be used to build a klibc udev now.
773 NAME="" will not create any nodes, but execute RUN keys. To completely
774 ignore an event the OPTION "ignore_device" should be used.
776 After removal of the reorder queue, events with a TIMEOUT can be executed
777 without any queuing now.
781 Fixed bug in udevd, if inotify is not available. We depend on netlink
782 uevents now, kernels without that event source will not work with that
783 version of udev anymore.
787 The rule parsing happens now in the daemon once at startup, all udev
788 event processes inherit the already parsed rules from the daemon.
789 It is shipped with SUSE10.0 and reduces heavily the system load at
790 startup. The option to save precompiled rules and let the udev process
791 pick the them up is removed, as it's no longer needed.
793 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
794 device. Libsysfs is changed to "translate" the requested link into the
795 real device path, as it would happen with the hotplug event. Otherwise
796 device removal and the udev database will not work.
798 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
801 A few improvements for vol_id, the filesytem probing code.
805 Fix a stupid typo in extras/run_directory for "make install".
807 scsi_id creates the temporary devnode now in /dev for usage with a
808 non-writable /tmp directory.
810 The uevent kernel socket buffer can carry app. 50.000 events now,
811 let's see who can break this again. :)
813 The upcoming kernel will have a new input driver core integration.
814 Some class devices are now symlinks to the real device. libsysfs
815 needs a fix for this to work correctly. Udevstart of older udev
816 versions will _not_ create these devices!
820 Fix a 'install' target in the Makefile, that prevents EXTRAS from
825 A bunch of mostly trivial bugfixes. From now on no node name or
826 symlink name can contain any character than plain whitelisted ascii
827 characters or validated utf8 byte-streams. This is needed for the
828 /dev/disk/by-label/* links, because we import untrusted data and
829 export it to the filesystem.
833 More bugfixes. If udevd was started from the kernel, we don't
834 have stdin/stdout/stderr, which broke the forked tools in some
839 Bugfix. udevstart event ordering was broken for a long time.
840 The new run_program() uncovered it, because /dev/null was not
841 available while we try to run external programs.
842 Now udevstart should create it before we run anything.
846 Minor bugfixes and some distro rules updates. If you don't have the
847 persistent disk rules in /dev/disk/by-*/* on your distro, just
848 grab it from here. :)
852 We can use socket communication now to pass events from udev to
854 RUN+="socket:/org/freedesktop/hal/udev_event"
855 will pass the whole udev event to the HAL daemon without the need
856 for a forked helper. (See ChangeLog for udevmonitor, as an example)
860 Mostly bugfixes and see ChangeLog.
862 The test for the existence of an environment value should be
864 ENV{KEY}=="*" to ENV{KEY}=="?*"
865 because "*" will not fail anymore, if the key does not exist or
870 Bugfixes and a few tweaks described in the ChangeLog.
874 Mostly a Bugfix release.
876 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
877 timing with custom rules.
881 We changed the internal rule storage format. Our large rule files took
882 2 MB of RAM, with the change we are down to 99kB.
884 If the device-node has been created with default name and no symlink or
885 options are to remenber, it is not longer stored in the udevdb. HAL will
886 need to be updated to work correctly with that change.
888 To overrride optimization flags, OPTFLAGS may be used now.
896 Major changes happened with this release. The goal is to take over the
897 complete kernel-event handling and provide a more efficient way to dispatch
898 kernel events. Replacing most of the current shell script logic and the
899 kernel forked helper with a netlink-daemon and a rule-based event handling.
901 o udevd listens to netlink events now. The first valid netlink event
902 will make udevd ignore any message from udevsend that contains a
903 SEQNUM, to avoid duplicate events. The forked events can be disabled
905 echo "" > /proc/sys/kernel/hotplug
906 For full support, the broken input-subsytem needs to be fixed, not to
907 bypass the driver core.
909 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
910 removed from udev itself and must be emulated by calling small
911 helper binaries provided in the extras folder:
912 make EXTRAS=extras/run_directory/
913 will build udev_run_devd and udev_run_hotplugd, which can be called
914 from a rule if needed:
915 RUN+="/sbin/udev_run_hotplugd"
916 The recommended way to handle this is to convert all the calls from
917 the directories to explicit udev rules and get completely rid of the
918 multiplexing. (To catch a ttyUSB event, you now no longer need to
919 fork and exit 300 tty script instances you are not interested in, it
920 is just one rule that matches exactly the device.)
922 o udev handles now _all_ events not just events for class and block
923 devices, this way it is possible to control the complete event
924 behavior with udev rules. Especially useful for rules like:
925 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
927 o As used in the modalias rule, udev supports now textual
928 substitution placeholder along with the usual format chars. This
929 needs to be documented, for now it's only visible in udev_rules_parse.c.
931 o The rule keys support now more operations. This is documented in the
932 man page. It is possible to add values to list-keys like the SYMLINK
933 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
934 Also "final"-assignments are supported by using KEY:="value", which will
935 prevent changing the key by any later rule.
937 o kernel 2.6.12 has the "detached_state" attribute removed from
938 sysfs, which was used to recognize sysfs population. We switched that
939 to wait for the "bus" link, which is only available in kernels after 2.6.11.
940 Running this udev version on older kernels may cause a short delay for
943 o To provide infrastructure for persistent device naming, the id programs:
944 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
945 to export the probed data in environment key format:
946 pim:~ # /sbin/ata_id --export /dev/hda
947 ID_MODEL=HTS726060M9AT00
948 ID_SERIAL=MRH401M4G6UM9B
952 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
953 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
956 kay@pim:~> tree /dev/disk
959 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
960 | `-- IBM-Memory_Key -> ../../sda
962 | |-- swap -> ../../hda1
963 | |-- date -> ../../sda1
964 | `-- home -> ../../hda3
966 |-- 2E08712B0870F2E7 -> ../../hda3
967 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
968 |-- E845-7A89 -> ../../sda1
969 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
971 The IMPORT= operation will import these keys in the environment and make
972 it available for later PROGRAM= and RUN= executed programs. The keys are
973 also stored in the udevdb and can be queried from there with one of the
976 o A few binaries are silently added to the repository, which can be used
977 to replay kernel events from initramfs instead of using coldplug. udevd
978 can be instructed now to queue-up events while the stored events from
979 initramfs are filled into the udevd-queue. This code is still under
980 development and there is no documentation now besides the code itself.
981 The additional binaries get compiled, but are not installed by default.
983 o There is also a temporary fix for a performance problem where too many
984 events happen in parallel and every event needs to parse the rules.
985 udev can now read precompiled rules stored on disk. This is likely to be
986 replaced by a more elegant solution in a future udev version.
990 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
991 Fix for libsysfs not to expect this file was added.
995 All rules are applied now, but only the first matching rule with a NAME-key
996 will be applied. All later rules with NAME-key are completely ignored. This
997 way system supplied symlinks or permissions gets applied to user-defined
1001 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1002 to some rules, to keep the old behavior.
1004 The rules are read on "remove"-events too. That makes is possible to match
1005 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1006 instruct udev to ignore an event (OPTIONS="ignore_device").
1007 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1009 The new RUN-key supports rule-based execution of programs after device-node
1010 handling. This is meant as a general replacement for the dev.d/-directories
1011 to give fine grained control over the execution of programs.
1013 The %s{}-sysfs format char replacement values are searched at any of the
1014 devices in the device chain now, not only at the class-device.
1016 We support log priority levels now. The value udev_log in udev.conf is used
1017 to determine what is printed to syslog. This makes it possible to
1018 run a version with compiled-in debug messages in a production environment
1019 which is sometimes needed to find a bug.
1020 It is still possible to supress the inclusion of _any_ syslog usage with
1021 USE_LOG=false to create the smallest possible binaries if needed.
1022 The configured udev_log value can be overridden with the environment variable
1027 Possible use of a system-wide klibc:
1028 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1029 will link against an external klibc and our own version will be ignored.
1033 We support an unlimited count of symlinks now.
1035 If USE_STATIC=true is passed to a glibc build, we link statically and use
1036 a built-in userdb parser to resolve user and group names.
1038 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1039 we walk up the chain of physical devices to find a match.
1041 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1042 easy to skip certain attribute matches without composing rules with weird
1043 character class negations like:
1044 KERNEL="[!s][!c][!d]*"
1045 this can now be replaced with:
1047 The current simple '=' is still supported, and should work as it does today,
1048 but existing rules should be converted if possible, to be better readable.
1050 We have new ENV{}== key now, to match against a maximum of 5 environment
1053 udevstart is its own binary again, because we don't need co carry this araound
1054 with every forked event.
~ianmdlvl / elogind.git / blob