Edit: /usr/lib/udev/rules.d/56-dm-parts.rules (1442B)
# Rules for partitions created by kpartx
KERNEL!="dm-*", GOTO="dm_parts_end"
ACTION!="add|change", GOTO="dm_parts_end"
ENV{DM_UUID}!="part[0-9]*", GOTO="dm_parts_end"
# We must take care that symlinks don't get lost,
# even if blkid fails in 13-dm-disk.rules later.
#
# Fixme: we have currently no way to avoid calling blkid on
# partitions of broken mpath maps such as DM_NOSCAN.
# But when partition devices appear, kpartx has likely read
# the partition table shortly before, so odds are not bad
# that blkid will also succeed.
IMPORT{db}="ID_FS_USAGE"
IMPORT{db}="ID_FS_UUID_ENC"
IMPORT{db}="ID_FS_LABEL_ENC"
IMPORT{db}="ID_PART_ENTRY_NAME"
IMPORT{db}="ID_PART_ENTRY_UUID"
IMPORT{db}="ID_PART_ENTRY_SCHEME"
# Maps should take precedence over their members.
ENV{DM_UDEV_LOW_PRIORITY_FLAG}!="1", OPTIONS+="link_priority=50"
# Set some additional symlinks that typically exist for mpath
# path members, too, and should be overridden.
#
# kpartx_id is very robust, it works for suspended maps and maps
# with 0 dependencies. It sets DM_TYPE, DM_PART, DM_WWN
IMPORT{program}=="kpartx_id %M %m $env{DM_UUID}"
# DM_TYPE only has a reasonable value for partitions on multipath.
ENV{DM_UUID}=="*-mpath-*", ENV{DM_TYPE}=="?*", ENV{DM_SERIAL}=="?*" \
SYMLINK+="disk/by-id/$env{DM_TYPE}-$env{DM_SERIAL}-part$env{DM_PART}"
ENV{DM_WWN}=="?*", ENV{DM_PART}=="?*", \
SYMLINK+="disk/by-id/wwn-$env{DM_WWN}-part$env{DM_PART}"
LABEL="dm_parts_end"