# Copyright (C) 2009 Red Hat, Inc. All rights reserved.
#
# This file is part of LVM2.

# Udev rules for LVM.
#
# These rules create symlinks for LVM logical volumes in
# /dev/VG directory (VG is an actual VG name). Some udev
# environment variables are set (they can be used in later
# rules as well):
#   DM_LV_NAME - logical volume name
#   DM_VG_NAME - volume group name
#   DM_LV_LAYER - logical volume layer (blank if not set)

# "add" event is processed on coldplug only!
ACTION!="add|change", GOTO="lvm_end"
ENV{DM_UDEV_RULES_VSN}!="?*", GOTO="lvm_end"
ENV{DM_UUID}!="LVM-?*", GOTO="lvm_end"

# Use DM name and split it up into its VG/LV/layer constituents.
IMPORT{program}="(DM_EXEC)/dmsetup splitname --nameprefixes --noheadings --rows $env{DM_NAME}"

# DM_SUBSYSTEM_UDEV_FLAG0 is the 'NOSCAN' flag for LVM subsystem.
# This flag is used to temporarily disable selected rules to prevent any
# processing or scanning done on the LVM volume before LVM has any chance
# to zero any stale metadata found within the LV data area. Such stale
# metadata could cause false claim of the LV device, keeping it open etc.
#
# If the NOSCAN flag is present, backup selected existing flags used to
# disable rules, then set them firmly so those selected rules are surely skipped.
# Restore these flags once the NOSCAN flag is dropped (which is normally any
# uevent that follows for this LV, even an artificially generated one).
ENV{DM_SUBSYSTEM_UDEV_FLAG0}=="1", ENV{DM_NOSCAN}="1", ENV{DM_DISABLE_OTHER_RULES_FLAG_OLD}="$env{DM_UDEV_DISABLE_OTHER_RULES_FLAG}", ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="1"
ENV{DM_SUBSYSTEM_UDEV_FLAG0}!="1", IMPORT{db}="DM_NOSCAN", IMPORT{db}="DM_DISABLE_OTHER_RULES_FLAG_OLD"
ENV{DM_SUBSYSTEM_UDEV_FLAG0}!="1", ENV{DM_NOSCAN}=="1", ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="$env{DM_DISABLE_OTHER_RULES_FLAG_OLD}", \
				   ENV{DM_DISABLE_OTHER_RULES_FLAG_OLD}="", ENV{DM_NOSCAN}=""

ENV{DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG}=="1", GOTO="lvm_end"

# Do not create symlinks for inappropriate subdevices.
ENV{DM_LV_NAME}=="pvmove?*|?*_vorigin", GOTO="lvm_disable"
ENV{DM_LV_LAYER}=="?*", GOTO="lvm_disable"

# Create symlinks for top-level devices only.
ENV{DM_VG_NAME}=="?*", ENV{DM_LV_NAME}=="?*", SYMLINK+="$env{DM_VG_NAME}/$env{DM_LV_NAME}", GOTO="lvm_end"

LABEL="lvm_disable"
ENV{DM_UDEV_DISABLE_DISK_RULES_FLAG}="1"
ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="1"
OPTIONS:="nowatch"

LABEL="lvm_end"