1# Copyright (C) 2009 Red Hat, Inc. All rights reserved. 2# 3# This file is part of LVM2. 4 5# Udev rules for device-mapper devices. 6# 7# These rules create a DM control node in /dev/mapper directory. 8# The rules also create nodes named dm-x (x is a number) in /dev 9# directory and symlinks to these nodes with names given by 10# the actual DM names. Some udev environment variables are set 11# for use in later rules: 12# DM_NAME - actual DM device's name 13# DM_UUID - UUID set for DM device (blank if not specified) 14# DM_SUSPENDED - suspended state of DM device (0 or 1) 15# DM_UDEV_RULES_VSN - DM udev rules version 16# 17# These rules cover only basic device-mapper functionality in udev. 18# 19# Various DM subsystems may contain further subsystem-specific rules 20# in 11-dm-<subsystem_name>.rules which should be installed together 21# with the DM subsystem and which extend these basic rules. 22# For example: 23# 11-dm-lvm.rules for LVM subsystem 24# 11-dm-mpath.rules for multipath subsystem (since version 0.6.0, recommended!) 25# 26# Even more specific rules may be required by subsystems so always 27# check subsystem's upstream repository for recent set of rules. 28# Also, keep in mind that recent rules may also require recent 29# subsystem-specific binaries. 30 31KERNEL=="device-mapper", NAME="mapper/control" 32 33SUBSYSTEM!="block", GOTO="dm_end" 34KERNEL!="dm-[0-9]*", GOTO="dm_end" 35 36# Device created, major and minor number assigned - "add" event generated. 37# Table loaded - no event generated. 38# Device resumed (or renamed) - "change" event generated. 39# Device removed - "remove" event generated. 40# 41# The dm-X nodes are always created, even on "add" event, we can't suppress 42# that (the node is created even earlier with devtmpfs). All the symlinks 43# (e.g. /dev/mapper) are created in right time after a device has its table 44# loaded and is properly resumed. For this reason, direct use of dm-X nodes 45# is not recommended. 46ACTION!="add|change", GOTO="dm_end" 47 48# Decode udev control flags and set environment variables appropriately. 49# These flags are encoded in DM_COOKIE variable that was introduced in 50# kernel version 2.6.31. Therefore, we can use this feature with 51# kernels >= 2.6.31 only. Cookie is not decoded for remove event. 52ENV{DM_COOKIE}=="?*", IMPORT{program}="/sbin/dmsetup udevflags $env{DM_COOKIE}" 53 54# Rule out easy-to-detect inappropriate events first. 55ENV{DISK_RO}=="1", GOTO="dm_disable" 56 57# There is no cookie set nor any flags encoded in events not originating 58# in libdevmapper so we need to detect this and try to behave correctly. 59# For such spurious events, regenerate all flags from current udev database content 60# (this information would normally be inaccessible for spurious ADD and CHANGE events). 61ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}=="1", ENV{DM_ACTIVATION}="1", GOTO="dm_flags_done" 62IMPORT{db}="DM_UDEV_DISABLE_DM_RULES_FLAG" 63IMPORT{db}="DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG" 64IMPORT{db}="DM_UDEV_DISABLE_DISK_RULES_FLAG" 65IMPORT{db}="DM_UDEV_DISABLE_OTHER_RULES_FLAG" 66IMPORT{db}="DM_UDEV_LOW_PRIORITY_FLAG" 67IMPORT{db}="DM_UDEV_DISABLE_LIBRARY_FALLBACK_FLAG" 68IMPORT{db}="DM_UDEV_PRIMARY_SOURCE_FLAG" 69IMPORT{db}="DM_UDEV_FLAG7" 70IMPORT{db}="DM_UDEV_RULES" 71IMPORT{db}="DM_UDEV_RULES_VSN" 72LABEL="dm_flags_done" 73 74# Normally, we operate on "change" events. But when coldplugging, there's an 75# "add" event present. We have to recognize this and do our actions in this 76# particular situation, too. Also, we don't want the nodes to be created 77# prematurely on "add" events while not coldplugging. We check 78# DM_UDEV_PRIMARY_SOURCE_FLAG to see if the device was activated correctly 79# before and if not, we ignore the "add" event totally. This way we can support 80# udev triggers generating "add" events (e.g. "udevadm trigger --action=add" or 81# "echo add > /sys/block/<dm_device>/uevent"). The trigger with "add" event is 82# also used at boot to reevaluate udev rules for all existing devices activated 83# before (e.g. in initrd). If udev is used in initrd, we require the udev init 84# script to not remove the existing udev database so we can reuse the information 85# stored at the time of device activation in the initrd. 86ACTION!="add", GOTO="dm_no_coldplug" 87ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}!="1", GOTO="dm_disable" 88ENV{DM_ACTIVATION}="1" 89LABEL="dm_no_coldplug" 90 91# Putting it together, following table is used to recognize genuine and spurious events. 92# N.B. Spurious events are generated based on use of the WATCH udev 93# rule or by triggering an event manually by "udevadm trigger" call 94# or by "echo <event_name> > /sys/block/dm-X/uevent". 95# 96# EVENT DM_UDEV_PRIMARY_SOURCE_FLAG DM_ACTIVATION 97# ====================================================================== 98# add event (genuine) 0 0 99# change event (genuine) 1 1 100# add event (spurious) 101# |_ dev still not active 0 0 102# \_ dev already active 1 1 103# change event (spurious) 104# |_ dev still not active 0 0 105# \_ dev already active 1 0 106 107# "dm" sysfs subdirectory is available in newer versions of DM 108# only (kernels >= 2.6.29). We have to check for its existence 109# and use dmsetup tool instead to get the DM name, uuid and 110# suspended state if the "dm" subdirectory is not present. 111# The "suspended" item was added even later (kernels >= 2.6.31), 112# so we also have to call dmsetup if the kernel version used 113# is in between these releases. 114TEST=="dm", ENV{DM_NAME}="$attr{dm/name}", ENV{DM_UUID}="$attr{dm/uuid}", ENV{DM_SUSPENDED}="$attr{dm/suspended}" 115TEST!="dm", IMPORT{program}="/sbin/dmsetup info -j %M -m %m -c --nameprefixes --noheadings --rows -o name,uuid,suspended" 116ENV{DM_SUSPENDED}!="?*", IMPORT{program}="/sbin/dmsetup info -j %M -m %m -c --nameprefixes --noheadings --rows -o suspended" 117 118# dmsetup tool provides suspended state information in textual 119# form with values "Suspended"/"Active". We translate it to 120# 0/1 respectively to be consistent with sysfs values. 121ENV{DM_SUSPENDED}=="Active", ENV{DM_SUSPENDED}="0" 122ENV{DM_SUSPENDED}=="Suspended", ENV{DM_SUSPENDED}="1" 123 124# This variable provides a reliable way to check that device-mapper 125# rules were installed. It means that all needed variables are set 126# by these rules directly so there's no need to acquire them again 127# later. Other rules can alternate the functionality based on this 128# fact (e.g. fallback to rules that behave correctly even without 129# these rules installed). It also provides versioning for any 130# possible future changes. 131# VSN 1 - original rules 132# VSN 2 - add support for synthesized events 133ENV{DM_UDEV_RULES}="1" 134ENV{DM_UDEV_RULES_VSN}="2" 135 136ENV{DM_UDEV_DISABLE_DM_RULES_FLAG}!="1", ENV{DM_NAME}=="?*", SYMLINK+="mapper/$env{DM_NAME}" 137 138# Avoid processing and scanning a DM device in the other (foreign) 139# rules if it is in suspended state. However, we still keep 'disk' 140# and 'DM subsystem' related rules enabled in this case. 141ENV{DM_SUSPENDED}=="1", ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="1" 142 143GOTO="dm_end" 144 145LABEL="dm_disable" 146ENV{DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG}="1" 147ENV{DM_UDEV_DISABLE_DISK_RULES_FLAG}="1" 148ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="1" 149OPTIONS:="nowatch" 150 151LABEL="dm_end" 152