# Copyright 2019 Canonical, Ltd.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import logging
import subprocess
import pyudev
from probert.utils import (
read_sys_block_size_bytes,
sane_block_devices,
udev_get_attributes,
)
log = logging.getLogger('probert.raid')
SUPPORTED_RAID_TYPES = ['raid0', 'raid1', 'raid5', 'raid6', 'raid10']
def mdadm_assemble(scan=True, ignore_errors=True):
cmd = ['mdadm', '--detail', '--scan', '-v']
try:
subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
except subprocess.CalledProcessError as e:
log.error('Failed mdadm_assemble command %s: %s', cmd, e)
except FileNotFoundError as e:
log.error('Failed mdadm_assemble, mdadm command not found: %s', e)
return
def get_mdadm_array_spares(md_device, detail):
def role_key_to_dev(rolekey):
# MD_DEVICE_dev_dm_5_ROLE=spare -> MD_DEVICE_dev_dm_5_DEV
devname_mangled = rolekey.split('MD_DEVICE_')[1].split('_ROLE')[0]
return 'MD_DEVICE_%s_DEV' % devname_mangled
def keymatch(key, data, role):
prefix = key.startswith('MD_DEVICE_')
suffix = key.endswith('_ROLE')
matches = data.get(key) == role
return (prefix and suffix and matches)
def get_dev_from_key(key, data):
return data.get(role_key_to_dev(key))
return [get_dev_from_key(key, detail) for key in detail.keys()
if keymatch(key, detail, 'spare')]
def get_mdadm_array_members(md_device, detail):
''' extract array devices and spares from mdadm --detail --export output
MD_LEVEL=raid5
MD_DEVICES=3
MD_METADATA=1.2
MD_UUID=7fe1895e:34dcb6dc:d1bcbb9c:f3e05134
MD_NAME=s1lp6:raid5-2406-2407-2408-2409
MD_DEVICE_ev_dm_5_ROLE=spare
MD_DEVICE_ev_dm_5_DEV=/dev/dm-5
MD_DEVICE_ev_dm_3_ROLE=1
MD_DEVICE_ev_dm_3_DEV=/dev/dm-3
MD_DEVICE_ev_dm_4_ROLE=2
MD_DEVICE_ev_dm_4_DEV=/dev/dm-4
MD_DEVICE_ev_dm_2_ROLE=0
MD_DEVICE_ev_dm_2_DEV=/dev/dm-2
returns (['/dev/dm2', '/dev/dm-3', '/dev/dm-4'], ['/dev/dm-5'])
'''
md_device_keys = [key for key in detail.keys()
if key.startswith('MD_DEVICE_') and key.endswith('_DEV')]
spares = sorted(get_mdadm_array_spares(md_device, detail))
devices = sorted([detail[key] for key in md_device_keys
if detail[key] not in spares])
return (devices, spares)
def extract_mdadm_raid_name(conf):
''' return the raid array name, removing homehost if present.
MD_NAME=s1lp6:raid5-2406-2407-2408-2409
returns 'raid5-2406-2407-2408-2409'
'''
raid_name = conf.get('MD_NAME')
if ':' in raid_name:
_, raid_name = raid_name.split(':')
return raid_name
def probe(context=None, report=False):
"""Initiate an mdadm assemble to awaken existing MDADM devices.
For each md block device, extract required information needed
to describe the array for recreation or reuse as needed.
mdadm tooling provides information about the raid type,
the members, the size, the name, uuids, metadata version.
"""
mdadm_assemble()
# ignore passed context, must read udev after assembling mdadm devices
context = pyudev.Context()
raids = {}
for device in sane_block_devices(context):
if 'MD_NAME' in device and device.get('DEVTYPE') == 'disk':
devname = device['DEVNAME']
attrs = udev_get_attributes(device)
attrs['size'] = str(read_sys_block_size_bytes(devname))
devices, spares = get_mdadm_array_members(devname, device)
cfg = dict(device)
cfg.update({'raidlevel': device['MD_LEVEL'],
'devices': devices,
'spare_devices': spares})
raids[devname] = cfg
return raids
