Volume discovery and local storage management lib
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# All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import os
from oslo_concurrency import lockutils
from oslo_log import log as logging
from oslo_service import loopingcall
import six
from os_brick.i18n import _LE, _LI, _LW
from os_brick import exception
from os_brick import initiator
from os_brick.initiator.connectors import base
from os_brick.initiator import linuxfc
from os_brick import utils
synchronized = lockutils.synchronized_with_prefix('os-brick-')
LOG = logging.getLogger(__name__)
class FibreChannelConnector(base.BaseLinuxConnector):
"""Connector class to attach/detach Fibre Channel volumes."""
def __init__(self, root_helper, driver=None,
execute=None, use_multipath=False,
*args, **kwargs):
self._linuxfc = linuxfc.LinuxFibreChannel(root_helper, execute)
super(FibreChannelConnector, self).__init__(
root_helper, driver=driver,
*args, **kwargs)
self.use_multipath = use_multipath
def set_execute(self, execute):
super(FibreChannelConnector, self).set_execute(execute)
def get_connector_properties(root_helper, *args, **kwargs):
"""The Fibre Channel connector properties."""
props = {}
fc = linuxfc.LinuxFibreChannel(root_helper,
wwpns = fc.get_fc_wwpns()
if wwpns:
props['wwpns'] = wwpns
wwnns = fc.get_fc_wwnns()
if wwnns:
props['wwnns'] = wwnns
return props
def get_search_path(self):
"""Where do we look for FC based volumes."""
return '/dev/disk/by-path'
def _get_possible_volume_paths(self, connection_properties, hbas):
ports = connection_properties['target_wwn']
possible_devs = self._get_possible_devices(hbas, ports)
lun = connection_properties.get('target_lun', 0)
host_paths = self._get_host_devices(possible_devs, lun)
return host_paths
def get_volume_paths(self, connection_properties):
volume_paths = []
# first fetch all of the potential paths that might exist
# how the FC fabric is zoned may alter the actual list
# that shows up on the system. So, we verify each path.
hbas = self._linuxfc.get_fc_hbas_info()
device_paths = self._get_possible_volume_paths(
connection_properties, hbas)
for path in device_paths:
if os.path.exists(path):
return volume_paths
def extend_volume(self, connection_properties):
"""Update the local kernel's size information.
Try and update the local kernel's size information
for an FC volume.
volume_paths = self.get_volume_paths(connection_properties)
if volume_paths:
return self._linuxscsi.extend_volume(volume_paths)
LOG.warning(_LW("Couldn't find any volume paths on the host to "
"extend volume for %(props)s"),
{'props': connection_properties})
raise exception.VolumePathsNotFound()
def connect_volume(self, connection_properties):
"""Attach the volume to instance_name.
:param connection_properties: The dictionary that describes all
of the target volume attributes.
:type connection_properties: dict
:returns: dict
connection_properties for Fibre Channel must include:
target_wwn - World Wide Name
target_lun - LUN id of the volume
LOG.debug("execute = %s", self._execute)
device_info = {'type': 'block'}
hbas = self._linuxfc.get_fc_hbas_info()
host_devices = self._get_possible_volume_paths(
connection_properties, hbas)
if len(host_devices) == 0:
# this is empty because we don't have any FC HBAs
_LW("We are unable to locate any Fibre Channel devices"))
raise exception.NoFibreChannelHostsFound()
# The /dev/disk/by-path/... node is not always present immediately
# We only need to find the first device. Once we see the first device
# multipath will have any others.
def _wait_for_device_discovery(host_devices):
tries = self.tries
for device in host_devices:
LOG.debug("Looking for Fibre Channel dev %(device)s",
{'device': device})
if os.path.exists(device):
self.host_device = device
# get the /dev/sdX device. This is used
# to find the multipath device.
self.device_name = os.path.realpath(device)
raise loopingcall.LoopingCallDone()
if self.tries >= self.device_scan_attempts:
LOG.error(_LE("Fibre Channel volume device not found."))
raise exception.NoFibreChannelVolumeDeviceFound()
LOG.info(_LI("Fibre Channel volume device not yet found. "
"Will rescan & retry. Try number: %(tries)s."),
{'tries': tries})
self.tries = self.tries + 1
self.host_device = None
self.device_name = None
self.tries = 0
timer = loopingcall.FixedIntervalLoopingCall(
_wait_for_device_discovery, host_devices)
tries = self.tries
if self.host_device is not None and self.device_name is not None:
LOG.debug("Found Fibre Channel volume %(name)s "
"(after %(tries)s rescans)",
{'name': self.device_name, 'tries': tries})
# find out the WWN of the device
device_wwn = self._linuxscsi.get_scsi_wwn(self.host_device)
LOG.debug("Device WWN = '%(wwn)s'", {'wwn': device_wwn})
device_info['scsi_wwn'] = device_wwn
# see if the new drive is part of a multipath
# device. If so, we'll use the multipath device.
if self.use_multipath:
(device_path, multipath_id) = (super(
FibreChannelConnector, self)._discover_mpath_device(
device_wwn, connection_properties, self.device_name))
if multipath_id:
# only set the multipath_id if we found one
device_info['multipath_id'] = multipath_id
device_path = self.host_device
device_info['path'] = device_path
LOG.debug("connect_volume returning %s", device_info)
return device_info
def _get_host_devices(self, possible_devs, lun):
host_devices = []
for pci_num, target_wwn in possible_devs:
host_device = "/dev/disk/by-path/pci-%s-fc-%s-lun-%s" % (
return host_devices
def _get_possible_devices(self, hbas, wwnports):
"""Compute the possible fibre channel device options.
:param hbas: available hba devices.
:param wwnports: possible wwn addresses. Can either be string
or list of strings.
:returns: list of (pci_id, wwn) tuples
Given one or more wwn (mac addresses for fibre channel) ports
do the matrix math to figure out a set of pci device, wwn
tuples that are potentially valid (they won't all be). This
provides a search space for the device connection.
# the wwn (think mac addresses for fiber channel devices) can
# either be a single value or a list. Normalize it to a list
# for further operations.
wwns = []
if isinstance(wwnports, list):
for wwn in wwnports:
elif isinstance(wwnports, six.string_types):
raw_devices = []
for hba in hbas:
pci_num = self._get_pci_num(hba)
if pci_num is not None:
for wwn in wwns:
target_wwn = "0x%s" % wwn.lower()
raw_devices.append((pci_num, target_wwn))
return raw_devices
def disconnect_volume(self, connection_properties, device_info):
"""Detach the volume from instance_name.
:param connection_properties: The dictionary that describes all
of the target volume attributes.
:type connection_properties: dict
:param device_info: historical difference, but same as connection_props
:type device_info: dict
connection_properties for Fibre Channel must include:
target_wwn - World Wide Name
target_lun - LUN id of the volume
devices = []
wwn = None
volume_paths = self.get_volume_paths(connection_properties)
mpath_path = None
for path in volume_paths:
real_path = self._linuxscsi.get_name_from_path(path)
if self.use_multipath and not mpath_path:
wwn = self._linuxscsi.get_scsi_wwn(path)
mpath_path = self._linuxscsi.find_multipath_device_path(wwn)
if mpath_path:
device_info = self._linuxscsi.get_device_info(real_path)
LOG.debug("devices to remove = %s", devices)
self._remove_devices(connection_properties, devices)
def _remove_devices(self, connection_properties, devices):
# There may have been more than 1 device mounted
# by the kernel for this volume. We have to remove
# all of them
for device in devices:
def _get_pci_num(self, hba):
# NOTE(walter-boring)
# device path is in format of (FC and FCoE) :
# /sys/devices/pci0000:00/0000:00:03.0/0000:05:00.3/host2/fc_host/host2
# /sys/devices/pci0000:20/0000:20:03.0/0000:21:00.2/net/ens2f2/ctlr_2
# /host3/fc_host/host3
# we always want the value prior to the host or net value
if hba is not None:
if "device_path" in hba:
device_path = hba['device_path'].split('/')
for index, value in enumerate(device_path):
if value.startswith('net') or value.startswith('host'):
return device_path[index - 1]
return None