cinder/cinder/volume/drivers/lvm.py

658 lines
27 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""
Driver for Linux servers running LVM.
"""
import math
import os
import re
from oslo.config import cfg
from cinder import exception
from cinder import flags
from cinder.image import image_utils
from cinder.openstack.common import log as logging
from cinder import utils
from cinder.volume import driver
from cinder.volume import iscsi
LOG = logging.getLogger(__name__)
volume_opts = [
cfg.StrOpt('volume_group',
default='cinder-volumes',
help='Name for the VG that will contain exported volumes'),
cfg.StrOpt('volume_clear',
default='zero',
help='Method used to wipe old volumes (valid options are: '
'none, zero, shred)'),
cfg.IntOpt('volume_clear_size',
default=0,
help='Size in MiB to wipe at start of old volumes. 0 => all'),
cfg.StrOpt('volume_dd_blocksize',
default='1M',
help='The default block size used when clearing volumes'),
cfg.StrOpt('pool_size',
default=None,
help='Size of thin provisioning pool '
'(None uses entire cinder VG)'),
cfg.IntOpt('lvm_mirrors',
default=0,
help='If set, create lvms with multiple mirrors. Note that '
'this requires lvm_mirrors + 2 pvs with available space'),
]
FLAGS = flags.FLAGS
FLAGS.register_opts(volume_opts)
class LVMVolumeDriver(driver.VolumeDriver):
"""Executes commands relating to Volumes."""
def __init__(self, *args, **kwargs):
super(LVMVolumeDriver, self).__init__(*args, **kwargs)
self.configuration.append_config_values(volume_opts)
def check_for_setup_error(self):
"""Returns an error if prerequisites aren't met"""
out, err = self._execute('vgs', '--noheadings', '-o', 'name',
run_as_root=True)
volume_groups = out.split()
if self.configuration.volume_group not in volume_groups:
exception_message = (_("volume group %s doesn't exist")
% self.configuration.volume_group)
raise exception.VolumeBackendAPIException(data=exception_message)
def _create_volume(self, volume_name, sizestr):
cmd = ['lvcreate', '-L', sizestr, '-n', volume_name,
self.configuration.volume_group]
if self.configuration.lvm_mirrors:
cmd += ['-m', self.configuration.lvm_mirrors, '--nosync']
terras = int(sizestr[:-1]) / 1024.0
if terras >= 1.5:
rsize = int(2 ** math.ceil(math.log(terras) / math.log(2)))
# NOTE(vish): Next power of two for region size. See:
# http://red.ht/U2BPOD
cmd += ['-R', str(rsize)]
self._try_execute(*cmd, run_as_root=True)
def _copy_volume(self, srcstr, deststr, size_in_g, clearing=False):
# Use O_DIRECT to avoid thrashing the system buffer cache
extra_flags = ['iflag=direct', 'oflag=direct']
# Check whether O_DIRECT is supported
try:
self._execute('dd', 'count=0', 'if=%s' % srcstr, 'of=%s' % deststr,
*extra_flags, run_as_root=True)
except exception.ProcessExecutionError:
extra_flags = []
# If the volume is being unprovisioned then
# request the data is persisted before returning,
# so that it's not discarded from the cache.
if clearing and not extra_flags:
extra_flags.append('conv=fdatasync')
# Perform the copy
self._execute('dd', 'if=%s' % srcstr, 'of=%s' % deststr,
'count=%d' % (size_in_g * 1024),
'bs=%s' % self.configuration.volume_dd_blocksize,
*extra_flags, run_as_root=True)
def _volume_not_present(self, volume_name):
path_name = '%s/%s' % (self.configuration.volume_group, volume_name)
try:
self._try_execute('lvdisplay', path_name, run_as_root=True)
except Exception as e:
# If the volume isn't present
return True
return False
def _delete_volume(self, volume, size_in_g):
"""Deletes a logical volume."""
# zero out old volumes to prevent data leaking between users
# TODO(ja): reclaiming space should be done lazy and low priority
dev_path = self.local_path(volume)
if os.path.exists(dev_path):
self.clear_volume(volume)
self._try_execute('lvremove', '-f', "%s/%s" %
(self.configuration.volume_group,
self._escape_snapshot(volume['name'])),
run_as_root=True)
def _sizestr(self, size_in_g):
if int(size_in_g) == 0:
return '100M'
return '%sG' % size_in_g
# Linux LVM reserves name that starts with snapshot, so that
# such volume name can't be created. Mangle it.
def _escape_snapshot(self, snapshot_name):
if not snapshot_name.startswith('snapshot'):
return snapshot_name
return '_' + snapshot_name
def create_volume(self, volume):
"""Creates a logical volume. Can optionally return a Dictionary of
changes to the volume object to be persisted."""
self._create_volume(volume['name'], self._sizestr(volume['size']))
def create_volume_from_snapshot(self, volume, snapshot):
"""Creates a volume from a snapshot."""
self._create_volume(volume['name'], self._sizestr(volume['size']))
self._copy_volume(self.local_path(snapshot), self.local_path(volume),
snapshot['volume_size'])
def delete_volume(self, volume):
"""Deletes a logical volume."""
if self._volume_not_present(volume['name']):
# If the volume isn't present, then don't attempt to delete
return True
# TODO(yamahata): lvm can't delete origin volume only without
# deleting derived snapshots. Can we do something fancy?
out, err = self._execute('lvdisplay', '--noheading',
'-C', '-o', 'Attr',
'%s/%s' % (self.configuration.volume_group,
volume['name']),
run_as_root=True)
# fake_execute returns None resulting unit test error
if out:
out = out.strip()
if (out[0] == 'o') or (out[0] == 'O'):
raise exception.VolumeIsBusy(volume_name=volume['name'])
self._delete_volume(volume, volume['size'])
def clear_volume(self, volume):
"""unprovision old volumes to prevent data leaking between users."""
vol_path = self.local_path(volume)
size_in_g = volume.get('size')
size_in_m = self.configuration.volume_clear_size
if not size_in_g:
LOG.warning(_("Size for volume: %s not found, "
"skipping secure delete.") % volume['name'])
return
if self.configuration.volume_clear == 'none':
return
LOG.info(_("Performing secure delete on volume: %s") % volume['id'])
if self.configuration.volume_clear == 'zero':
if size_in_m == 0:
return self._copy_volume('/dev/zero',
vol_path, size_in_g,
clearing=True)
else:
clear_cmd = ['shred', '-n0', '-z', '-s%dMiB' % size_in_m]
elif self.configuration.volume_clear == 'shred':
clear_cmd = ['shred', '-n3']
if size_in_m:
clear_cmd.append('-s%dMiB' % size_in_m)
else:
LOG.error(_("Error unrecognized volume_clear option: %s"),
self.configuration.volume_clear)
return
clear_cmd.append(vol_path)
self._execute(*clear_cmd, run_as_root=True)
def create_snapshot(self, snapshot):
"""Creates a snapshot."""
orig_lv_name = "%s/%s" % (self.configuration.volume_group,
snapshot['volume_name'])
self._try_execute('lvcreate', '-L',
self._sizestr(snapshot['volume_size']),
'--name', self._escape_snapshot(snapshot['name']),
'--snapshot', orig_lv_name, run_as_root=True)
def delete_snapshot(self, snapshot):
"""Deletes a snapshot."""
if self._volume_not_present(self._escape_snapshot(snapshot['name'])):
# If the snapshot isn't present, then don't attempt to delete
LOG.warning(_("snapshot: %s not found, "
"skipping delete operations") % snapshot['name'])
return True
# TODO(yamahata): zeroing out the whole snapshot triggers COW.
# it's quite slow.
self._delete_volume(snapshot, snapshot['volume_size'])
def local_path(self, volume):
# NOTE(vish): stops deprecation warning
escaped_group = self.configuration.volume_group.replace('-', '--')
escaped_name = self._escape_snapshot(volume['name']).replace('-', '--')
return "/dev/mapper/%s-%s" % (escaped_group, escaped_name)
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))
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))
def create_cloned_volume(self, volume, src_vref):
"""Creates a clone of the specified volume."""
LOG.info(_('Creating clone of volume: %s') % src_vref['id'])
volume_name = FLAGS.volume_name_template % src_vref['id']
temp_id = 'tmp-snap-%s' % src_vref['id']
temp_snapshot = {'volume_name': volume_name,
'size': src_vref['size'],
'volume_size': src_vref['size'],
'name': 'clone-snap-%s' % src_vref['id'],
'id': temp_id}
self.create_snapshot(temp_snapshot)
self._create_volume(volume['name'], self._sizestr(volume['size']))
try:
self._copy_volume(self.local_path(temp_snapshot),
self.local_path(volume),
src_vref['size'])
finally:
self.delete_snapshot(temp_snapshot)
def clone_image(self, volume, image_location):
return False
def backup_volume(self, context, backup, backup_service):
"""Create a new backup from an existing volume."""
volume = self.db.volume_get(context, backup['volume_id'])
volume_path = self.local_path(volume)
with utils.temporary_chown(volume_path):
with utils.file_open(volume_path) as volume_file:
backup_service.backup(backup, volume_file)
def restore_backup(self, context, backup, volume, backup_service):
"""Restore an existing backup to a new or existing volume."""
volume_path = self.local_path(volume)
with utils.temporary_chown(volume_path):
with utils.file_open(volume_path, 'wb') as volume_file:
backup_service.restore(backup, volume['id'], volume_file)
class LVMISCSIDriver(LVMVolumeDriver, driver.ISCSIDriver):
"""Executes commands relating to ISCSI volumes.
We make use of model provider properties as follows:
``provider_location``
if present, contains the iSCSI target information in the same
format as an ietadm discovery
i.e. '<ip>:<port>,<portal> <target IQN>'
``provider_auth``
if present, contains a space-separated triple:
'<auth method> <auth username> <auth password>'.
`CHAP` is the only auth_method in use at the moment.
"""
def __init__(self, *args, **kwargs):
self.tgtadm = iscsi.get_target_admin()
super(LVMISCSIDriver, self).__init__(*args, **kwargs)
def set_execute(self, execute):
super(LVMISCSIDriver, self).set_execute(execute)
self.tgtadm.set_execute(execute)
def ensure_export(self, context, volume):
"""Synchronously recreates an export for a logical volume."""
# NOTE(jdg): tgtadm doesn't use the iscsi_targets table
# TODO(jdg): In the future move all of the dependent stuff into the
# cooresponding target admin class
if isinstance(self.tgtadm, iscsi.LioAdm):
try:
volume_info = self.db.volume_get(context, volume['id'])
(auth_method,
auth_user,
auth_pass) = volume_info['provider_auth'].split(' ', 3)
chap_auth = self._iscsi_authentication(auth_method,
auth_user,
auth_pass)
except exception.NotFound:
LOG.debug("volume_info:", volume_info)
LOG.info(_("Skipping ensure_export. No iscsi_target "
"provision for volume: %s"), volume['id'])
return
iscsi_name = "%s%s" % (FLAGS.iscsi_target_prefix, volume['name'])
volume_path = "/dev/%s/%s" % (FLAGS.volume_group, volume['name'])
iscsi_target = 1
self.tgtadm.create_iscsi_target(iscsi_name, iscsi_target,
0, volume_path, chap_auth,
check_exit_code=False)
return
if not isinstance(self.tgtadm, iscsi.TgtAdm):
try:
iscsi_target = self.db.volume_get_iscsi_target_num(
context,
volume['id'])
except exception.NotFound:
LOG.info(_("Skipping ensure_export. No iscsi_target "
"provisioned for volume: %s"), volume['id'])
return
else:
iscsi_target = 1 # dummy value when using TgtAdm
chap_auth = None
# Check for https://bugs.launchpad.net/cinder/+bug/1065702
old_name = None
volume_name = volume['name']
if (volume['provider_location'] is not None and
volume['name'] not in volume['provider_location']):
msg = _('Detected inconsistency in provider_location id')
LOG.debug(msg)
old_name = self._fix_id_migration(context, volume)
if 'in-use' in volume['status']:
volume_name = old_name
old_name = None
iscsi_name = "%s%s" % (self.configuration.iscsi_target_prefix,
volume_name)
volume_path = "/dev/%s/%s" % (self.configuration.volume_group,
volume_name)
# NOTE(jdg): For TgtAdm case iscsi_name is the ONLY param we need
# should clean this all up at some point in the future
self.tgtadm.create_iscsi_target(iscsi_name, iscsi_target,
0, volume_path, chap_auth,
check_exit_code=False,
old_name=old_name)
def _fix_id_migration(self, context, volume):
"""Fix provider_location and dev files to address bug 1065702.
For volumes that the provider_location has NOT been updated
and are not currently in-use we'll create a new iscsi target
and remove the persist file.
If the volume is in-use, we'll just stick with the old name
and when detach is called we'll feed back into ensure_export
again if necessary and fix things up then.
Details at: https://bugs.launchpad.net/cinder/+bug/1065702
"""
model_update = {}
pattern = re.compile(r":|\s")
fields = pattern.split(volume['provider_location'])
old_name = fields[3]
volume['provider_location'] = \
volume['provider_location'].replace(old_name, volume['name'])
model_update['provider_location'] = volume['provider_location']
self.db.volume_update(context, volume['id'], model_update)
start = os.getcwd()
os.chdir('/dev/%s' % self.configuration.volume_group)
try:
(out, err) = self._execute('readlink', old_name)
except exception.ProcessExecutionError:
link_path = '/dev/%s/%s' % (self.configuration.volume_group,
old_name)
LOG.debug(_('Symbolic link %s not found') % link_path)
os.chdir(start)
return
rel_path = out.rstrip()
self._execute('ln',
'-s',
rel_path, volume['name'],
run_as_root=True)
os.chdir(start)
return old_name
def _ensure_iscsi_targets(self, context, host):
"""Ensure that target ids have been created in datastore."""
# NOTE(jdg): tgtadm doesn't use the iscsi_targets table
# TODO(jdg): In the future move all of the dependent stuff into the
# cooresponding target admin class
if not isinstance(self.tgtadm, iscsi.TgtAdm):
host_iscsi_targets = self.db.iscsi_target_count_by_host(context,
host)
if host_iscsi_targets >= self.configuration.iscsi_num_targets:
return
# NOTE(vish): Target ids start at 1, not 0.
target_end = self.configuration.iscsi_num_targets + 1
for target_num in xrange(1, target_end):
target = {'host': host, 'target_num': target_num}
self.db.iscsi_target_create_safe(context, target)
def create_export(self, context, volume):
"""Creates an export for a logical volume."""
iscsi_name = "%s%s" % (self.configuration.iscsi_target_prefix,
volume['name'])
volume_path = "/dev/%s/%s" % (self.configuration.volume_group,
volume['name'])
model_update = {}
# TODO(jdg): In the future move all of the dependent stuff into the
# cooresponding target admin class
if not isinstance(self.tgtadm, iscsi.TgtAdm):
lun = 0
self._ensure_iscsi_targets(context, volume['host'])
iscsi_target = self.db.volume_allocate_iscsi_target(context,
volume['id'],
volume['host'])
else:
lun = 1 # For tgtadm the controller is lun 0, dev starts at lun 1
iscsi_target = 0 # NOTE(jdg): Not used by tgtadm
# Use the same method to generate the username and the password.
chap_username = utils.generate_username()
chap_password = utils.generate_password()
chap_auth = self._iscsi_authentication('IncomingUser', chap_username,
chap_password)
# NOTE(jdg): For TgtAdm case iscsi_name is the ONLY param we need
# should clean this all up at some point in the future
tid = self.tgtadm.create_iscsi_target(iscsi_name,
iscsi_target,
0,
volume_path,
chap_auth)
model_update['provider_location'] = self._iscsi_location(
self.configuration.iscsi_ip_address, tid, iscsi_name, lun)
model_update['provider_auth'] = self._iscsi_authentication(
'CHAP', chap_username, chap_password)
return model_update
def remove_export(self, context, volume):
"""Removes an export for a logical volume."""
# NOTE(jdg): tgtadm doesn't use the iscsi_targets table
# TODO(jdg): In the future move all of the dependent stuff into the
# cooresponding target admin class
if isinstance(self.tgtadm, iscsi.LioAdm):
try:
iscsi_target = self.db.volume_get_iscsi_target_num(
context,
volume['id'])
except exception.NotFound:
LOG.info(_("Skipping remove_export. No iscsi_target "
"provisioned for volume: %s"), volume['id'])
return
self.tgtadm.remove_iscsi_target(iscsi_target, 0, volume['id'])
return
elif not isinstance(self.tgtadm, iscsi.TgtAdm):
try:
iscsi_target = self.db.volume_get_iscsi_target_num(
context,
volume['id'])
except exception.NotFound:
LOG.info(_("Skipping remove_export. No iscsi_target "
"provisioned for volume: %s"), volume['id'])
return
else:
iscsi_target = 0
try:
# NOTE: provider_location may be unset if the volume hasn't
# been exported
location = volume['provider_location'].split(' ')
iqn = location[1]
# ietadm show will exit with an error
# this export has already been removed
self.tgtadm.show_target(iscsi_target, iqn=iqn)
except Exception as e:
LOG.info(_("Skipping remove_export. No iscsi_target "
"is presently exported for volume: %s"), volume['id'])
return
self.tgtadm.remove_iscsi_target(iscsi_target, 0, volume['id'])
def get_volume_stats(self, refresh=False):
"""Get volume status.
If 'refresh' is True, run update the stats first."""
if refresh:
self._update_volume_status()
return self._stats
def _update_volume_status(self):
"""Retrieve status info from volume group."""
LOG.debug(_("Updating volume status"))
data = {}
# Note(zhiteng): These information are driver/backend specific,
# each driver may define these values in its own config options
# or fetch from driver specific configuration file.
backend_name = self.configuration.safe_get('volume_backend_name')
data["volume_backend_name"] = backend_name or 'LVM_iSCSI'
data["vendor_name"] = 'Open Source'
data["driver_version"] = '1.0'
data["storage_protocol"] = 'iSCSI'
data['total_capacity_gb'] = 0
data['free_capacity_gb'] = 0
data['reserved_percentage'] = self.configuration.reserved_percentage
data['QoS_support'] = False
try:
out, err = self._execute('vgs', '--noheadings', '--nosuffix',
'--unit=G', '-o', 'name,size,free',
self.configuration.volume_group,
run_as_root=True)
except exception.ProcessExecutionError as exc:
LOG.error(_("Error retrieving volume status: "), exc.stderr)
out = False
if out:
volume = out.split()
data['total_capacity_gb'] = float(volume[1].replace(',', '.'))
data['free_capacity_gb'] = float(volume[2].replace(',', '.'))
self._stats = data
def _iscsi_location(self, ip, target, iqn, lun=None):
return "%s:%s,%s %s %s" % (ip, self.configuration.iscsi_port,
target, iqn, lun)
def _iscsi_authentication(self, chap, name, password):
return "%s %s %s" % (chap, name, password)
class ThinLVMVolumeDriver(LVMISCSIDriver):
"""Subclass for thin provisioned LVM's."""
def __init__(self, *args, **kwargs):
super(ThinLVMVolumeDriver, self).__init__(*args, **kwargs)
def check_for_setup_error(self):
"""Returns an error if prerequisites aren't met"""
out, err = self._execute('lvs', '--option',
'name', '--noheadings',
run_as_root=True)
pool_name = "%s-pool" % FLAGS.volume_group
if pool_name not in out:
if not FLAGS.pool_size:
out, err = self._execute('vgs', FLAGS.volume_group,
'--noheadings', '--options',
'name,size', run_as_root=True)
size = re.sub(r'[\.][\d][\d]', '', out.split()[1])
else:
size = "%s" % FLAGS.pool_size
pool_path = '%s/%s' % (FLAGS.volume_group, pool_name)
out, err = self._execute('lvcreate', '-T', '-L', size,
pool_path, run_as_root=True)
def _do_lvm_snapshot(self, src_lvm_name, dest_vref, is_cinder_snap=True):
if is_cinder_snap:
new_name = self._escape_snapshot(dest_vref['name'])
else:
new_name = dest_vref['name']
self._try_execute('lvcreate', '-s', '-n', new_name,
src_lvm_name, run_as_root=True)
def create_volume(self, volume):
"""Creates a logical volume. Can optionally return a Dictionary of
changes to the volume object to be persisted."""
sizestr = self._sizestr(volume['size'])
vg_name = ("%s/%s-pool" % (FLAGS.volume_group, FLAGS.volume_group))
self._try_execute('lvcreate', '-T', '-V', sizestr, '-n',
volume['name'], vg_name, run_as_root=True)
def delete_volume(self, volume):
"""Deletes a logical volume."""
if self._volume_not_present(volume['name']):
return True
self._try_execute('lvremove', '-f', "%s/%s" %
(FLAGS.volume_group,
self._escape_snapshot(volume['name'])),
run_as_root=True)
def create_cloned_volume(self, volume, src_vref):
"""Creates a clone of the specified volume."""
LOG.info(_('Creating clone of volume: %s') % src_vref['id'])
orig_lv_name = "%s/%s" % (FLAGS.volume_group, src_vref['name'])
self._do_lvm_snapshot(orig_lv_name, volume, False)
def create_snapshot(self, snapshot):
"""Creates a snapshot of a volume."""
orig_lv_name = "%s/%s" % (FLAGS.volume_group, snapshot['volume_name'])
self._do_lvm_snapshot(orig_lv_name, snapshot)