deb-cinder/cinder/volume/drivers/block_device.py
Yuriy Nesenenko 5cbec4cd77 Implement snapshots-related features for Block Device Driver
This patch adds the create_snapshot, create_volume_from_snapshot
and delete_snapshot methods to Block Device driver.

Related blueprint: block-device-driver-minimum-features-set

Change-Id: If86dca417234ea2c58fbce4e30a1626b288de3f6
2015-12-14 17:13:59 +02:00

303 lines
12 KiB
Python

# Copyright (c) 2013 Mirantis, Inc.
# 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_config import cfg
from oslo_log import log as logging
from oslo_utils import importutils
from oslo_utils import units
from cinder import context
from cinder import exception
from cinder.i18n import _, _LI, _LW
from cinder.image import image_utils
from cinder import objects
from cinder import utils
from cinder.volume import driver
from cinder.volume import utils as volutils
LOG = logging.getLogger(__name__)
volume_opts = [
cfg.ListOpt('available_devices',
default=[],
help='List of all available devices'),
]
CONF = cfg.CONF
CONF.register_opts(volume_opts)
class BlockDeviceDriver(driver.BaseVD, driver.LocalVD,
driver.CloneableImageVD, driver.TransferVD):
VERSION = '2.2.0'
def __init__(self, *args, **kwargs):
super(BlockDeviceDriver, self).__init__(*args, **kwargs)
self.configuration.append_config_values(volume_opts)
self.backend_name = \
self.configuration.safe_get('volume_backend_name') or "BlockDev"
target_driver =\
self.target_mapping[self.configuration.safe_get('iscsi_helper')]
self.target_driver = importutils.import_object(
target_driver,
configuration=self.configuration,
db=self.db,
executor=self._execute)
def check_for_setup_error(self):
pass
def _update_provider_location(self, object, device):
# We update provider_location and host to mark device as used to
# avoid race with other threads.
# TODO(ynesenenko): need to remove DB access from driver
object.update({'provider_location': device, 'host': self.host})
object.save()
@utils.synchronized('block_device', external=True)
def create_volume(self, volume):
device = self.find_appropriate_size_device(volume.size)
LOG.info(_LI("Creating %(volume)s on %(device)s"),
{"volume": volume.name, "device": device})
self._update_provider_location(volume, device)
def delete_volume(self, volume):
"""Deletes a logical volume."""
self._clear_block_device(volume)
def _clear_block_device(self, device):
"""Deletes a block device."""
dev_path = self.local_path(device)
if not dev_path or dev_path not in \
self.configuration.available_devices:
return
if os.path.exists(dev_path) and \
self.configuration.volume_clear != 'none':
dev_size = self._get_devices_sizes([dev_path])
volutils.clear_volume(
dev_size[dev_path], dev_path,
volume_clear=self.configuration.volume_clear,
volume_clear_size=self.configuration.volume_clear_size)
else:
LOG.warning(_LW("The device %s won't be cleared."), device)
if device.status == "error_deleting":
msg = _("Failed to delete device.")
LOG.error(msg, resource=device)
raise exception.VolumeDriverException(msg)
def local_path(self, device):
if device.provider_location:
path = device.provider_location.rsplit(" ", 1)
return path[-1]
else:
return None
def copy_image_to_volume(self, context, volume, image_service, image_id):
"""Fetch the image from image_service and write it to the volume."""
image_utils.fetch_to_raw(context,
image_service,
image_id,
self.local_path(volume),
self.configuration.volume_dd_blocksize,
size=volume.size)
def copy_volume_to_image(self, context, volume, image_service, image_meta):
"""Copy the volume to the specified image."""
image_utils.upload_volume(context,
image_service,
image_meta,
self.local_path(volume))
@utils.synchronized('block_device', external=True)
def create_cloned_volume(self, volume, src_vref):
LOG.info(_LI('Creating clone of volume: %s.'), src_vref.id)
device = self.find_appropriate_size_device(src_vref.size)
dev_size = self._get_devices_sizes([device])
volutils.copy_volume(
self.local_path(src_vref), device,
dev_size[device],
self.configuration.volume_dd_blocksize,
execute=self._execute)
self._update_provider_location(volume, device)
def get_volume_stats(self, refresh=False):
if refresh:
self._update_volume_stats()
return self._stats
def _update_volume_stats(self):
"""Retrieve stats info from volume group."""
dict_of_devices_sizes = self._devices_sizes()
used_devices = self._get_used_devices()
total_size = 0
free_size = 0
for device, size in dict_of_devices_sizes.items():
if device not in used_devices:
free_size += size
total_size += size
LOG.debug("Updating volume stats.")
backend_name = self.configuration.safe_get('volume_backend_name')
data = {'total_capacity_gb': total_size / units.Ki,
'free_capacity_gb': free_size / units.Ki,
'reserved_percentage': self.configuration.reserved_percentage,
'QoS_support': False,
'volume_backend_name': backend_name or self.__class__.__name__,
'vendor_name': "Open Source",
'driver_version': self.VERSION,
'storage_protocol': 'unknown'}
self._stats = data
def _get_used_paths(self, lst):
used_dev = set()
for item in lst:
local_path = self.local_path(item)
if local_path:
used_dev.add(local_path)
return used_dev
def _get_used_devices(self):
lst = objects.VolumeList.get_all_by_host(context.get_admin_context(),
self.host)
used_devices = self._get_used_paths(lst)
snp_lst = objects.SnapshotList.get_by_host(context.get_admin_context(),
self.host)
return used_devices.union(self._get_used_paths(snp_lst))
def _get_devices_sizes(self, dev_paths):
"""Return devices' sizes in Mb"""
out, _err = self._execute('blockdev', '--getsize64', *dev_paths,
run_as_root=True)
dev_sizes = {}
out = out.split('\n')
# blockdev returns devices' sizes in order that
# they have been passed to it.
for n, size in enumerate(out[:-1]):
dev_sizes[dev_paths[n]] = int(size) / units.Mi
return dev_sizes
def _devices_sizes(self):
available_devices = self.configuration.available_devices
return self._get_devices_sizes(available_devices)
def find_appropriate_size_device(self, size):
dict_of_devices_sizes = self._devices_sizes()
free_devices = (set(self.configuration.available_devices) -
self._get_used_devices())
if not free_devices:
raise exception.CinderException(_("No free disk"))
possible_device = None
possible_device_size = None
for device in free_devices:
dev_size = dict_of_devices_sizes[device]
if (size * units.Ki <= dev_size and
(possible_device is None or
dev_size < possible_device_size)):
possible_device = device
possible_device_size = dev_size
if possible_device:
return possible_device
else:
raise exception.CinderException(_("No big enough free disk"))
def extend_volume(self, volume, new_size):
dev_path = self.local_path(volume)
total_size = self._get_devices_sizes([dev_path])
# Convert from Megabytes to Gigabytes
size = total_size[dev_path] / units.Ki
if size < new_size:
msg = _("Insufficient free space available to extend volume.")
LOG.error(msg, resource=volume)
raise exception.CinderException(msg)
@utils.synchronized('block_device', external=True)
def create_snapshot(self, snapshot):
volume = snapshot.volume
if volume.status != 'available':
msg = _("Volume is not available.")
LOG.error(msg, resource=volume)
raise exception.CinderException(msg)
LOG.info(_LI('Creating volume snapshot: %s.'), snapshot.id)
device = self.find_appropriate_size_device(snapshot.volume_size)
dev_size = self._get_devices_sizes([device])
volutils.copy_volume(
self.local_path(volume), device,
dev_size[device],
self.configuration.volume_dd_blocksize,
execute=self._execute)
self._update_provider_location(snapshot, device)
def delete_snapshot(self, snapshot):
self._clear_block_device(snapshot)
@utils.synchronized('block_device', external=True)
def create_volume_from_snapshot(self, volume, snapshot):
LOG.info(_LI('Creating volume %s from snapshot.'), volume.id)
device = self.find_appropriate_size_device(snapshot.volume_size)
dev_size = self._get_devices_sizes([device])
volutils.copy_volume(
self.local_path(snapshot), device,
dev_size[device],
self.configuration.volume_dd_blocksize,
execute=self._execute)
self._update_provider_location(volume, device)
# ####### Interface methods for DataPath (Target Driver) ########
def ensure_export(self, context, volume):
volume_path = self.local_path(volume)
model_update = \
self.target_driver.ensure_export(
context,
volume,
volume_path)
return model_update
def create_export(self, context, volume, connector):
volume_path = self.local_path(volume)
export_info = self.target_driver.create_export(context,
volume,
volume_path)
return {
'provider_location': export_info['location'] + ' ' + volume_path,
'provider_auth': export_info['auth'],
}
def remove_export(self, context, volume):
self.target_driver.remove_export(context, volume)
def initialize_connection(self, volume, connector):
if connector['host'] != volutils.extract_host(volume.host, 'host'):
return self.target_driver.initialize_connection(volume, connector)
else:
return {
'driver_volume_type': 'local',
'data': {'device_path': self.local_path(volume)},
}
def validate_connector(self, connector):
return self.target_driver.validate_connector(connector)
def terminate_connection(self, volume, connector, **kwargs):
pass