9 "udevadm settle" now optionally accepts a range of events to wait for,
10 instead of waiting for "all" events.
16 The installed watch for block device metadata changes is now removed
17 during event hadling, because some (broken) tools may be called from udev
18 rules and (wrongly) open the device with write access. After the finished
19 event handling the watch is restored.
25 Device nodes can be watched for changes with inotify with OPTIONS="watch".
26 If closed after being opened for writing, a "change" uevent will occur.
27 /dev/disk/by-{label,uuid}/* symlinks will be automatically updated.
33 The udevadm test command has no longer a --force option, nodes and symlinks
34 are always updated with a test run now.
36 The udevd daemon can be started with --resolve-names=never to avoid all user
37 and group lookups (e.g. in cut-down systems) or --resolve-names=late to
38 lookup user and groups every time events are handled.
44 We are currently merging the Ubuntu rules in the udev default rules,
45 and get one step closer to provide a common Linux /dev setup, regarding
46 device names, symlinks, and default device permissions. On udev startup,
47 we now expect the following groups to be resolvable to their ids with
49 disk, cdrom, floppy, tape, audio, video, lp, tty, dialout, kmem.
50 LDAP setups need to make sure, that these groups are always resolvable at
51 bootup, with only the rootfs mounted, and without network access available.
53 Some systems may need to add some new, currently not used groups, or need
54 to add some users to new groups, but the cost of this change is minimal,
55 compared to the pain the current, rather random, differences between the
56 various distributions cause for upstream projects and third-party vendors.
58 In general, "normal" users who log into a machine should never be a member
59 of any such group, but the device-access should be managed by dynamic ACLs,
60 which get added and removed for the specific users on login/logout and
61 session activity/inactivity. These groups are only provided for custom setups,
62 and mainly system services, to allow proper privilege separation.
63 A video-streaming daemon uid would be a member of "audio" and "video", to get
64 access to the sound and video devices, but no "normal" user should ever belong
65 to the "audio" group, because he could listen to the built-in microphone with
66 any ssh-session established from the other side of the world.
68 /dev/serial/by-{id,path}/ now contains links for ttyUSB devices,
69 which do not depend on the kernel device name. As usual, unique
70 devices - only a single one per product connected, or a real
71 USB serial number in the device - are always found with the same
72 name in the by-id/ directory.
73 Completely identical devices may overwrite their names in by-id/
74 and can only be found reliably in the by-path/ directory. Devices
75 specified by by-path/ must not change their connection, like the
76 USB port number they are plugged in, to keep their name.
78 To support some advanced features, Linux 2.6.22 is the oldest supported
79 version now. The kernel config with enabled SYSFS_DEPRECATED is no longer
80 supported. Older kernels should still work, and devices nodes should be
81 reliably created, but some rules and libudev will not work correctly because
82 the old kernels do not provide the expected information or interfaces.
88 Fix for a possible segfault while swapping network interface names in udev
95 The group "video" is part of the default rules now.
99 Bugfix for kernels using SYSFS_DEPRECATED* option and finding parent
100 block devices in some cases. No common distro uses this option anymore,
101 and we do not get enough testing for this and recent udev versions. If
102 this option is not needed to run some old distro with a new kernel,
103 it should be disabled in the kernel config.
105 Bugfix for the $links substitution variable, which may crash if no links
106 are created. This should not happen in usual setups because we always
107 create /dev/{block,char}/ links.
109 The strings of the parsed rules, which are kept in memory, no longer
110 contain duplicate entries, or duplicate tails of strings. This, and the
111 new rules parsing/matching code reduces the total in-memory size of
112 a huge distro rule sets to 0.08 MB, compared to the 1.2MB of udev
115 The export of DEVTYPE=disk/partition got removed from the default
116 rules. This value is available from the kernel. The pnp shell script
117 modprobe hack is removed from the default rules. ACPI devices have _proper_
118 modalias support and take care of the same functionality.
119 Installations which support old kernels, but install current default
120 udev rules may want to add that to the compat rules file.
122 Libvolume_id now always probes for all known filesystems, and does not
123 stop at the first match. Some filesystems are marked as "exclusive probe",
124 and if any other filesytem type matches at the same time, libvolume_id
125 will, by default, not return any probing result. This is intended to prevent
126 mis-detection with conflicting left-over signatures found from earlier
127 file system formats. That way, we no longer depend on the probe-order
128 in case of multiple competing signatures. In some setups the kernel allows
129 to mount a volume with just the old filesystem signature still in place.
130 This may damage the new filesystem and cause data-loss, just by mounting
131 it. Because volume_id can not decide which one the correct signature is,
132 the wrong signatures need to be removed manually from the volume, or the
133 volume needs to be reformatted, to enable filesystem detection and possible
138 Fix segfault if compiled without optimization and dbg() does not get
139 compiled out and uses variables which are not available.
143 Bugfixes. (And maybe new bugs. :))
145 The rule matching engine got converted from a rule list to a token
146 array which reduced the in-memory rules representation of a full
147 featured distros with thousends of udev rules from 1.2MB to 0.12 MB.
148 Limits like 5 ENV and ATTR matches, and one single instance for most
149 other keys per rule are gone.
151 The NAME assignment is no longer special cased. If later rules assign
152 a NAME value again, the former value will be overwritten. As usual
153 for most other keys, the NAME value can be protected by doing a final
154 assignment with NAME:="<value>".
156 All udev code now uses libudev, which is also exported. The library
157 is still under development, marked as experimental, and its interface
158 may change as long as the DeviceKit integration is not finished.
160 Many thanks to Alan Jenkins for his continuous help, and finding and
161 optimizing some of the computing expensive parts.
167 Kernel devices and device nodes are connected now by reverse indizes in
168 /sys and /dev. A device number retrieved by a stat() or similar, the
169 kernel device directory can be found by looking up:
170 /sys/dev/{block,char}/<maj>:<min>
171 and the device node of the same device by looking up:
172 /dev/{block,char}/<maj>:<min>
176 Fix recently introduced bug, which caused a compilation without large
177 file support, where vol_id does not recognize raid signatures at the end
180 Firewire disks now create both, by-id/scsi-* and by-id/ieee-* links.
181 Seems some kernel versions prevent the creation of the ieee-* links,
182 so people used the scsi-* link which disappeared now.
184 More libudev work. Almost all udevadm functionality comes from libudev
187 udevadm trigger has a new option --type, which allows to trigger events
188 for "devices", for "subsystems", or "failed" devices. The old option
189 --retry-failed" still works, but is no longer mentioned in the man page.
195 The udevadm info --device-id-of-file= output has changed to use
196 the obvious format. Possible current users should use the --export
197 option which is not affected.
199 The old udev commands symlinks to udevadm are not installed, if
200 these symlinks are used, a warning is printed.
206 Optical drive's media is no longer probed for raid signatures,
207 reading the end of the device causes some devices to malfunction.
208 Also the offset of the last session found is used now to probe
211 The volume_id library got a major version number update to 1,
212 some deprecated functions are removed.
214 A shared library "libudev" gets installed now to provide access
215 to udev device information. DeviceKit, the successor of HAL, will
216 need this library to access the udev database and search sysfs for
218 The library is currently in an experimental state, also the API is
219 expected to change, as long as the DeviceKit integration is not
224 We use ./configure now. See INSTALL for details. Current
227 "/usr" - prefix for man pages, include files
229 "" - the root filesystem, prefix for libs and binaries
233 "lib" - directory name for libraries, not a path name
234 multilib 64bit systems may use "lib64" instead of "lib"
236 compile-in verbose debug messages
238 disable all logging and compile-out all log strings
240 link against SELInux libraries, to set the expected context
243 In the default rules, the group "disk" gets permissions 0660 instead
244 of 0640. One small step closer to unify distro rules. Some day, all
245 distros hopefully end up with the same set of rules.
247 No symlinks to udevadm are installed anymore, if they are still needed,
248 they should be provided by the package.
254 Default udev rules, which are not supposed to be edited by the user, should
255 be placed in /lib/udev/rules.d/ now, to make it clear that they are private to
256 the udev package and will be replaced with an update. Udev will pick up rule
258 /lib/udev/rules.d/ - default installed rules
259 /etc/udev/rules.d/ - user rules + on-the-fly generated rules
260 /dev/.udev/rules.d/ - temporary non-persistent rules created after bootup
261 It does not matter in which directory a rule file lives, all files are sorted
264 To help creating /dev/root, we have now:
265 $ udevadm info --export --export-prefix="ROOT_" --device-id-of-file=/
268 In case the current --device-id-of-file is already used, please switch to
269 the --export format version, it saves the output parsing and the old
270 format will be changed to use ':' as a separator, like the format in the
275 Fix cdrom_id to properly recognize blank media.
281 Tape drive id-data is queried from /dev/bsg/* instead of the tape
282 nodes. This avoids rewinding tapes on open().
288 The symlinks udevcontrol and udevtrigger are no longer installed by
291 The scsi_id program does not depend on sysfs anymore. It can speak
292 SGv4 now, so /dev/bsg/* device nodes can be used, to query SCSI device
293 data, which should solve some old problems with tape devices, where
294 we better do not open all tape device nodes to identify the device.
300 The cdrom_id program is replaced by an advanced version, which can
301 detect most common device types, and also properties of the inserted
302 media. This is part of moving some basic functionality from HAL into
303 udev (and the kernel).
309 The last WAIT_FOR_SYSFS rule is removed from the default rules.
311 The symlinks to udevadm for the debugging tools: udevmonitor and
312 udevtest are no longer created.
314 The symlinks to the udevadm man page for the old tool names are
317 Abstract namespace sockets paths in RUN+="socket:@<path>" rules,
318 should be prefixed with '@' to indicate that the path is not a
329 Udevstart is removed from the tree, it did not get installed for
330 a long time now, and is long replaced by trigger and settle.
336 All udev tools are merged into a single binary called udevadm.
337 The old names of the tools are built-in commands in udevadm now.
338 Symlinks to udevadm, with the names of the old tools, provide
339 the same functionality as the standalone tools. There is also
340 only a single udevadm.8 man page left for all tools.
342 Tools like mkinitramfs should be checked, if they need to include
343 udevadm in the list of files.
353 The etc/udev/rules.d/ directory now contains a default set of basic
354 udev rules. This initial version is the result of a rules file merge
355 of Fedora and openSUSE. For these both distros only a few specific
356 rules are left in their own file, named after the distro. Rules which
357 are optionally installed, because they are only valid for a specific
358 architecture, or rules for subsystems which are not always used are
359 in etc/udev/packages/.
365 Dynamic rules can be created in /dev/.udev/rules.d/ to trigger
366 actions by dynamically created rules.
368 SYMLINK=="<value>" matches agains the entries in the list of
369 currently defined symlinks. The links are not created in the
370 filesystem at that point in time, but the values can be matched.
372 RUN{ignore_error}+="<program>" will ignore any exit code from the
373 program and not record as a failed event.
379 Final merge of patches/features from the Ubuntu package.
385 Control characters in filesystem label strings are no longer silenty
386 removed, but hex-encoded, to be able to uniquely identify the device
387 by its symlink in /dev/disk/by-label/.
388 If libvolume_id is used by mount(8), LABEL= will work as expected,
389 if slashes or other characters are used in the label string.
391 To test the existence of a file, TEST=="<file>" and TEST!="<file>"
392 can be specified now. The TEST key accepts an optional mode mask
393 TEST{0100}=="<is executable file>".
395 Scsi_id now supports a mode without expecting scsi-specific sysfs
396 entries to allow the extraction of cciss-device persistent properties.
402 In the future, we may see uuid's which are just simple character
403 strings (see the DDF Raid Specification). For that reason vol_id now
404 exports ID_FS_UUID_SAFE, just like ID_FS_LABEL_SAFE. For things like
405 the creation of symlinks, the *_SAFE values ensure, that no control
406 or whitespace characters are used in the filename.
408 Possible users of libvolume_id, please use the volume_id_get_* functions.
409 The public struct will go away in a future release of the library.
415 Removal of useless extras/eventrecorder.sh.
425 The directory multiplexer for dev.d/ and hotplug.d are finally removed
426 from the udev package.
432 Symlinks can have priorities now, the priority is assigned to the device
433 and specified with OPTIONS="link_priority=100". Devices with higher
434 priorities overwrite the symlinks of devices with lower priorities.
435 If the device that currently owns the link, goes away, the symlink
436 will be removed, and recreated, pointing to the next device with the
437 highest actual priority. This should make /dev/disk/by-{label,uuid,id}
438 more reliable, if multiple devices contain the same metadata and overwrite
441 The dasd_id program is removed from the udev tree, and dasdinfo, with the
442 needed rules, are part of the s390-tools now.
444 Please add KERNEL=="[0-9]*:[0-9]*" to the scsi wait-for-sysfs rule,
445 we may get the scsi sysfs mess fixed some day, and this will only catch
446 the devices we are looking for.
448 USB serial numbers for storage devices have the target:lun now appended,
449 to make it possibble to distinguish broken multi-lun devices with all
450 the same SCSI identifiers.
452 Note: The extra "run_directory" which searches and executes stuff in
453 /etc/hotplug.d/ and /etc/dev.d/ is long deprecated, and will be removed
454 with the next release. Make sure, that you don't use it anymore, or
455 provides your own implementation of that inefficient stuff.
456 We are tired of reports about a "slow udev", because these directories
457 contain stuff, that runs with _every_ event, instead of using rules,
458 that run programs only for the matching events.
468 DRIVER== will match only for devices that actually have a real
469 driver. DRIVERS== must be used, if parent devices should be
470 included in the match.
472 Libvolume_id's "linux_raid" detection needed another fix.
480 Add additional check to volume_id detection of via_raid, cause
481 some company decided to put a matching pattern all over the empty
482 storage area of their music players.
486 Fix path_id for SAS devices.
490 The udev daemon can be started with --debug-trace now, which will
491 execute all events serialized to get a chance to catch a possible
492 action that crashes the box.
494 A warning is logged, if PHYSDEV* keys, the "device" link, or a parent
495 device attribute like $attr{../file} is used, only WAIT_FOR_SYSFS rules
496 are excluded from the warning. Referencing parent attributes directly
497 may break when something in the kernel driver model changes. Udev will
498 just find the attribute by walking up the parent chain.
500 Udevtrigger now sorts the list of devices depending on the device
501 dependency, so a "usb" device is triggered after the parent "pci"
506 Revert persistent-storage ata-serial '_' '-' replacement.
512 Udevtrigger can now filter the list of devices to be triggered. Matches
513 for subsystems or sysfs attributes can be specified.
515 The entries in /dev/.udev/queue and /dev/.udev/failed have changed to
516 zero-sized files to avoid pointing to /sys and confuse broken tools which
517 scan the /dev directory. To retry failed events, udevtrigger --retry-failed
520 The rules and scripts to create udev rules for persistent network
521 devices and optical drives are in the extras/rules_generator directory
522 now. If you use something similar, please consider replacing your own
523 version with this, to share the support effort. The rule_generator
524 installs its own rules into /etc/udev/rules.d.
526 The cdrom_id tool installs its own rule now in /etc/udev/rules.d, cause
527 the rule_generator depends on cdrom_id to be called in an earlier rule.
533 Renaming of some key names (the old names still work):
534 BUS -> SUBSYSTEMS, ID -> KERNELS, SYSFS -> ATTRS, DRIVER -> DRIVERS.
535 (The behavior of the key DRIVER will change soon in one of the next
536 releases, to match only the event device, please switch to DRIVERS
537 instead. If DRIVER is used, it will behave like DRIVERS, but an error
539 With the new key names, we have a more consistent and simpler scheme.
540 We can match the properties of the event device only, with: KERNEL,
541 SUBSYSTEM, ATTR, DRIVER. Or include all the parent devices in the match,
542 with: KERNELS, SUBSYSTEMS, ATTRS, DRIVERS. ID, BUS, SYSFS, DRIVER are no
543 longer mentioned in the man page and should be switched in the rule
546 ATTR{file}="value" can be used now, to write to a sysfs file of the
547 event device. Instead of:
548 ..., SYSFS{type}=="0|7|14", RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
550 ..., ATTR{type}=="0|7|14", ATTR{timeout}="60"
552 All the PHYSDEV* keys are deprecated and will be removed from a
554 PHYDEVPATH - is the path of a parent device and should not be
556 PHYSDEVBUS - is just a SUBSYSTEM value of a parent, and can be
557 matched with SUBSYSTEMS==
558 PHYSDEVDRIVER - for bus devices it is available as ENV{DRIVER}.
559 Newer kernels will have DRIVER in the environment,
560 for older kernels udev puts in. Class device will
561 no longer carry this property of a parent and
562 DRIVERS== can be used to match such a parent value.
563 Note that ENV{DRIVER} is only available for a few bus devices, where
564 the driver is already bound at device event time. On coldplug, the
565 events for a lot devices are already bound to a driver, and they will have
566 that value set. But on hotplug, at the time the kernel creates the device,
567 it can't know what driver may claim the device after that, therefore
568 in most cases it will be empty.
570 Failed events should now be re-triggered with:
571 udevtrigger --retry-failed.
572 Please switch to this command, so we keep the details of the /dev/.udev/failed/
573 files private to the udev tools. We may need to switch the current symlink
574 target, cause some obviously broken tools try to scan all files in /dev
575 including /dev/.udev/, find the links to /sys and end up stat()'ing sysfs files
576 million times. This takes ages on slow boxes.
578 The udevinfo attribute walk (-a) now works with giving a device node
579 name (-n) instead of a devpath (-p). The query now always works, also when
580 no database file was created by udev.
582 The built-in /etc/passwd /etc/group parser is removed, we always depend on
583 getpwnam() and getgrnam() now. One of the next releases will depend on
584 fnmatch() and may use getopt_long().
588 Bugfixes and small improvements.
592 Fix path_id for recent kernels.
598 Added support for swapping network interface names, by temporarily
599 renaming the device and wait for the target name to become free.
603 The built-in MODALIAS key and substitution is removed.
607 The binary firmware helper is replaced by the usual simple
608 shell script. Udevsend is removed from the tree.
616 Some more keys require the correct use of '==' and '=' depending
617 on the kind of operation beeing an assignment or a match. Rules
618 with invalid operations are skipped and logged to syslog. Please
619 test with udevtest if the parsing of your rules throws errors and
620 fix possibly broken rules.
624 Provide "udevsettle" to wait for all current udev events to finish.
625 It also watches the current kernel netlink queue by comparing the
626 even sequence number to make sure that there are no current pending
627 events that have not already arrived in the daemon.
631 Fix rule to skip persistent rules for removable IDE devices, which
632 also skipped optical IDE drives.
634 All *_id program are installed in /lib/udev/ by default now.
636 No binary is stripped anymore as this should be done in the
637 packaging process and not at build time.
639 libvolume_id is provided as a shared library now and vol_id is
640 linked against it. Also one of the next HAL versions will require
641 this library, and the HAL build process will also require the
642 header file to be installed. The copy of the same code in HAL will
643 be removed to have only a single copy left on the system.
647 Add persistent links for SCSI tapes. The rules file is renamed
648 to 60-persistent-storage.rules.
650 Create persistent path for usb devices. Can be used for all sorts
651 of devices that can't be distinguished by other properties like
652 multiple identical keyboards and mice connected to the same box.
654 Provide "udevtrigger" program to request events on coldplug. The
655 shell script is much too slow with thousends of devices.
659 Fix persistent disk rules to exclude removable IDE drives.
661 Warn if %e, $modalias or MODALIAS is used.
665 Fix queue export, which wasn't correct for subsequent add/remove
666 events for the same device.
670 Fix cramfs detection on big endian.
672 Make WAIT_FOR_SYSFS usable in "normal" rules and silent if the whole
677 If BUS== and SYSFS{}== have been used in the same rule, the sysfs
678 attributes were only checked at the parent device that matched the
679 by BUS requested subsystem. Fix it to also look at the device we
680 received the event for.
682 Build variable CROSS has changed to CROSS_COMPILE to match the kernel
687 Fix a bug where NAME="" would prevent RUN from beeing executed.
689 RUN="/bin/program" does not longer automatically add the subsystem
690 as the first parameter. This is from the days of /sbin/hotplug
691 which is dead now and it's just confusing to need to add a space at
692 the end of the program name to prevent this.
693 If you use rules that need the subsystem as the first parameter,
694 like the old "udev_run_hotlugd" and "udev_run_devd", add the subsystem
695 to the key like RUN+="/bin/program $env{SUBSYSTEM}".
699 The udev man page has moved to udev(7) as it does not describe a command
700 anymore. The programs udev, udevstart and udevsend are no longer installed
701 by default and must be copied manually, if they should be installed or
702 included in a package.
704 Fix a bug where "ignore_device" could run earlier collected RUN keys before
705 the ignore rule was applied.
707 More preparation for future sysfs changes. usb_id and scsi_id no longer
708 depend on a magic order of devices in the /devices chain. Specific devices
709 should be requested by their subsytem.
711 This will always find the scsi parent device without depending on a specific
713 dev = sysfs_device_get(devpath);
714 dev_usb = sysfs_device_get_parent_with_subsystem(dev, "scsi");
716 The "device" link in the current sysfs layout will be automatically
717 _resolved_ as a parent and in the new sysfs layout it will just _be_ the
718 parent in the devpath. If a device is requested by it's symlink, like all
719 class devices in the new sysfs layout will look like, it gets automatically
720 resolved and substituted with the real devpath and not the symlink path.
723 A similar logic must be applied to _all_ sysfs users, including
724 scripts, that search along parent devices in sysfs. The explicit use of
725 the "device" link must be avoided. With the future sysfs layout all
726 DEVPATH's will start with /devices/ and have a "subsystem" symlink poiting
727 back to the "class" or the "bus". The layout of the parent devices in
728 /devices is not necessarily expected to be stable across kernel releases and
729 searching for parents by their subsystem should make sysfs users tolerant
730 for changed parent chains.
734 Prepare udev to work with the experimental kernel patch, that moves
735 /sys/class devices to /sys/devices and /sys/block to /sys/class/block.
737 Clarify BUS, ID, $id usage and fix $id behavior. This prepares for
738 moving the class devices to /sys/devices.
740 Thanks again to Marco for help finding a hopefully nice compromise
741 to make %b simpler and working again.
745 Complete removal of libsysfs, replaced by simple helper functions
746 which are much simpler and a bit faster. The udev daemon operatesentirely
747 on event parameters and does not use sysfs for simple rules anymore.
748 Please report any new bugs/problems, that may be caused by this big
749 change. They will be fixed immediately.
751 The enumeration format character '%e' is deprecated and will be
752 removed sometimes from a future udev version. It never worked correctly
753 outside of udevstart, so we can't use it with the new parallel
754 coldplug. A simple enumeration is as useless as the devfs naming
755 scheme, just get rid of both if you still use it.
757 MODALIAS and $modalias is not needed and will be removed from one of
758 the next udev versions, replace it in all rules with ENV{MODALIAS} or
759 the sysfs "modalias" value.
761 Thanks a lot to Marco for all his help on finding and fixing bugs.
765 Let scsi_id request libata drive serial numbers from page 0x80.
767 Renamed etc/udev/persistent.rules to persistent-disk.rules and
768 added /dev/disk/by-name/* for device mapper device names.
770 Removed %e from the man page. It never worked reliably outside
771 of udevstart and udevstart is no longer recommended to use.
775 Symlinks are now exported to the event environment. Hopefully it's no
776 longer needed to run udevinfo from an event process, like it was
777 mentioned on the hotplug list:
778 UDEV [1134776873.702967] add@/block/sdb
781 DEVLINKS=/dev/disk/by-id/usb-IBM_Memory_Key_0218B301030027E8 /dev/disk/by-path/usb-0218B301030027E8:0:0:0
785 Fix a problem if udevsend is used as the hotplug handler and tries to use
786 syslog, which causes a "vc" event loop. 2.6.15 will make udevsend obsolete
787 and this kind of problems will hopefully go away soon.
791 All built-in logic to work around bad sysfs timing is removed with this
792 version. The need to wait for sysfs files is almost fixed with a kernel
793 version that doesn't work with this udev version anyway. Until we fix
794 the timing of the "bus" link creation, the former integrated logic should
795 be emulated by a rule placed before all other rules:
796 ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
798 The option "udev_db" does no longer exist. All udev state will be in
799 /$udev_root/.udev/ now, there is no longer an option to set this
801 If the init script or something else used this value, just depend on
802 this hardcoded path. But remember _all_content_ of this directory is
803 still private to udev and can change at any time.
805 Default location for rule sripts and helper programs is now: /lib/udev/.
806 Everything that is not useful on the commandline should go into this
807 directory. Some of the helpers in the extras folder are installed there
808 now. The rules need to be changed, to find the helpers there.
810 Also /lib/udev/devices is recommended as a directory where packages or
811 the user can place real device nodes, which get copied over to /dev at
812 every boot. This should replace the various solutions with custom config
815 Udevsend does no longer start the udev daemon. This must be done with
816 the init script that prepares /dev on tmpfs and creates the initial nodes,
817 before starting the daemon.
821 Silent a too verbose error logging for the old hotplug.d/ dev.d/
824 The copy of klibc is removed. A systemwide installed version of klibc
825 should be used to build a klibc udev now.
829 NAME="" will not create any nodes, but execute RUN keys. To completely
830 ignore an event the OPTION "ignore_device" should be used.
832 After removal of the reorder queue, events with a TIMEOUT can be executed
833 without any queuing now.
837 Fixed bug in udevd, if inotify is not available. We depend on netlink
838 uevents now, kernels without that event source will not work with that
839 version of udev anymore.
843 The rule parsing happens now in the daemon once at startup, all udev
844 event processes inherit the already parsed rules from the daemon.
845 It is shipped with SUSE10.0 and reduces heavily the system load at
846 startup. The option to save precompiled rules and let the udev process
847 pick the them up is removed, as it's no longer needed.
849 Kernel 2.6.15 will have symlinks at /class/input pointing to the real
850 device. Libsysfs is changed to "translate" the requested link into the
851 real device path, as it would happen with the hotplug event. Otherwise
852 device removal and the udev database will not work.
854 Using 'make STRIPCMD=' will leave the binaries unstripped for debugging
857 A few improvements for vol_id, the filesytem probing code.
861 Fix a stupid typo in extras/run_directory for "make install".
863 scsi_id creates the temporary devnode now in /dev for usage with a
864 non-writable /tmp directory.
866 The uevent kernel socket buffer can carry app. 50.000 events now,
867 let's see who can break this again. :)
869 The upcoming kernel will have a new input driver core integration.
870 Some class devices are now symlinks to the real device. libsysfs
871 needs a fix for this to work correctly. Udevstart of older udev
872 versions will _not_ create these devices!
876 Fix a 'install' target in the Makefile, that prevents EXTRAS from
881 A bunch of mostly trivial bugfixes. From now on no node name or
882 symlink name can contain any character than plain whitelisted ascii
883 characters or validated utf8 byte-streams. This is needed for the
884 /dev/disk/by-label/* links, because we import untrusted data and
885 export it to the filesystem.
889 More bugfixes. If udevd was started from the kernel, we don't
890 have stdin/stdout/stderr, which broke the forked tools in some
895 Bugfix. udevstart event ordering was broken for a long time.
896 The new run_program() uncovered it, because /dev/null was not
897 available while we try to run external programs.
898 Now udevstart should create it before we run anything.
902 Minor bugfixes and some distro rules updates. If you don't have the
903 persistent disk rules in /dev/disk/by-*/* on your distro, just
904 grab it from here. :)
908 We can use socket communication now to pass events from udev to
910 RUN+="socket:/org/freedesktop/hal/udev_event"
911 will pass the whole udev event to the HAL daemon without the need
912 for a forked helper. (See ChangeLog for udevmonitor, as an example)
916 Mostly bugfixes and see ChangeLog.
918 The test for the existence of an environment value should be
920 ENV{KEY}=="*" to ENV{KEY}=="?*"
921 because "*" will not fail anymore, if the key does not exist or
926 Bugfixes and a few tweaks described in the ChangeLog.
930 Mostly a Bugfix release.
932 Added WAIT_FOR_SYSFS="<attribute>" to be able to fight against the sysfs
933 timing with custom rules.
937 We changed the internal rule storage format. Our large rule files took
938 2 MB of RAM, with the change we are down to 99kB.
940 If the device-node has been created with default name and no symlink or
941 options are to remenber, it is not longer stored in the udevdb. HAL will
942 need to be updated to work correctly with that change.
944 To overrride optimization flags, OPTFLAGS may be used now.
952 Major changes happened with this release. The goal is to take over the
953 complete kernel-event handling and provide a more efficient way to dispatch
954 kernel events. Replacing most of the current shell script logic and the
955 kernel forked helper with a netlink-daemon and a rule-based event handling.
957 o udevd listens to netlink events now. The first valid netlink event
958 will make udevd ignore any message from udevsend that contains a
959 SEQNUM, to avoid duplicate events. The forked events can be disabled
961 echo "" > /proc/sys/kernel/hotplug
962 For full support, the broken input-subsytem needs to be fixed, not to
963 bypass the driver core.
965 o /etc/dev.d/ + /etc/hotplug.d/ directory multiplexing is completely
966 removed from udev itself and must be emulated by calling small
967 helper binaries provided in the extras folder:
968 make EXTRAS=extras/run_directory/
969 will build udev_run_devd and udev_run_hotplugd, which can be called
970 from a rule if needed:
971 RUN+="/sbin/udev_run_hotplugd"
972 The recommended way to handle this is to convert all the calls from
973 the directories to explicit udev rules and get completely rid of the
974 multiplexing. (To catch a ttyUSB event, you now no longer need to
975 fork and exit 300 tty script instances you are not interested in, it
976 is just one rule that matches exactly the device.)
978 o udev handles now _all_ events not just events for class and block
979 devices, this way it is possible to control the complete event
980 behavior with udev rules. Especially useful for rules like:
981 ACTION="add", DEVPATH="/devices/*", MODALIAS=="?*", RUN+="/sbin/modprobe $modalias"
983 o As used in the modalias rule, udev supports now textual
984 substitution placeholder along with the usual format chars. This
985 needs to be documented, for now it's only visible in udev_rules_parse.c.
987 o The rule keys support now more operations. This is documented in the
988 man page. It is possible to add values to list-keys like the SYMLINK
989 and RUN list with KEY+="value" and to clear the list by assigning KEY="".
990 Also "final"-assignments are supported by using KEY:="value", which will
991 prevent changing the key by any later rule.
993 o kernel 2.6.12 has the "detached_state" attribute removed from
994 sysfs, which was used to recognize sysfs population. We switched that
995 to wait for the "bus" link, which is only available in kernels after 2.6.11.
996 Running this udev version on older kernels may cause a short delay for
999 o To provide infrastructure for persistent device naming, the id programs:
1000 scsi_id, vol_id (former udev_volume_id), and ata_id (new) are able now
1001 to export the probed data in environment key format:
1002 pim:~ # /sbin/ata_id --export /dev/hda
1003 ID_MODEL=HTS726060M9AT00
1004 ID_SERIAL=MRH401M4G6UM9B
1005 ID_REVISION=MH4OA6BA
1007 The following rules:
1008 KERNEL="hd*[!0-9]", IMPORT="/sbin/ata_id --export $tempnode"
1009 KERNEL="hd*[!0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="disk/by-id/$env{ID_MODEL}_$env{ID_SERIAL}"
1012 kay@pim:~> tree /dev/disk
1015 | |-- HTS726060M9AT00_MRH401M4G6UM9B -> ../../hda
1016 | `-- IBM-Memory_Key -> ../../sda
1018 | |-- swap -> ../../hda1
1019 | |-- date -> ../../sda1
1020 | `-- home -> ../../hda3
1022 |-- 2E08712B0870F2E7 -> ../../hda3
1023 |-- 9352cfef-7687-47bc-a2a3-34cf136f72e1 -> ../../hda1
1024 |-- E845-7A89 -> ../../sda1
1025 `-- b2a61681-3812-4f13-a4ff-920d70604299 -> ../../hda2
1027 The IMPORT= operation will import these keys in the environment and make
1028 it available for later PROGRAM= and RUN= executed programs. The keys are
1029 also stored in the udevdb and can be queried from there with one of the
1032 o A few binaries are silently added to the repository, which can be used
1033 to replay kernel events from initramfs instead of using coldplug. udevd
1034 can be instructed now to queue-up events while the stored events from
1035 initramfs are filled into the udevd-queue. This code is still under
1036 development and there is no documentation now besides the code itself.
1037 The additional binaries get compiled, but are not installed by default.
1039 o There is also a temporary fix for a performance problem where too many
1040 events happen in parallel and every event needs to parse the rules.
1041 udev can now read precompiled rules stored on disk. This is likely to be
1042 replaced by a more elegant solution in a future udev version.
1046 With kernel version 2.6.12, the sysfs file "detached_state" was removed.
1047 Fix for libsysfs not to expect this file was added.
1051 All rules are applied now, but only the first matching rule with a NAME-key
1052 will be applied. All later rules with NAME-key are completely ignored. This
1053 way system supplied symlinks or permissions gets applied to user-defined
1057 Please check your rules setup, if you may need to add OPTIONS="last_rule"
1058 to some rules, to keep the old behavior.
1060 The rules are read on "remove"-events too. That makes is possible to match
1061 with keys that are available on remove (KERNEL, SUBSYSTEM, ID, ENV, ...) to
1062 instruct udev to ignore an event (OPTIONS="ignore_device").
1063 The new ACTION-key may be used to let a rule act only at a "remove"-event.
1065 The new RUN-key supports rule-based execution of programs after device-node
1066 handling. This is meant as a general replacement for the dev.d/-directories
1067 to give fine grained control over the execution of programs.
1069 The %s{}-sysfs format char replacement values are searched at any of the
1070 devices in the device chain now, not only at the class-device.
1072 We support log priority levels now. The value udev_log in udev.conf is used
1073 to determine what is printed to syslog. This makes it possible to
1074 run a version with compiled-in debug messages in a production environment
1075 which is sometimes needed to find a bug.
1076 It is still possible to supress the inclusion of _any_ syslog usage with
1077 USE_LOG=false to create the smallest possible binaries if needed.
1078 The configured udev_log value can be overridden with the environment variable
1083 Possible use of a system-wide klibc:
1084 make USE_KLIBC=true KLCC=/usr/bin/klcc all
1085 will link against an external klibc and our own version will be ignored.
1089 We support an unlimited count of symlinks now.
1091 If USE_STATIC=true is passed to a glibc build, we link statically and use
1092 a built-in userdb parser to resolve user and group names.
1094 The PLACE= key is gone. It can be replaced by an ID= for a long time, because
1095 we walk up the chain of physical devices to find a match.
1097 The KEY="<value>" format supports '=', '==', '!=,' , '+=' now. This makes it
1098 easy to skip certain attribute matches without composing rules with weird
1099 character class negations like:
1100 KERNEL="[!s][!c][!d]*"
1101 this can now be replaced with:
1103 The current simple '=' is still supported, and should work as it does today,
1104 but existing rules should be converted if possible, to be better readable.
1106 We have new ENV{}== key now, to match against a maximum of 5 environment
1109 udevstart is its own binary again, because we don't need co carry this araound
1110 with every forked event.
~ianmdlvl / elogind.git / blob