1013 lines
37 KiB
Python
1013 lines
37 KiB
Python
# Copyright (c) 2012 NetApp, Inc.
|
|
# Copyright (c) 2014 Red Hat, 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 hashlib
|
|
import json
|
|
import os
|
|
import re
|
|
import tempfile
|
|
|
|
from oslo.config import cfg
|
|
|
|
from cinder import exception
|
|
from cinder.image import image_utils
|
|
from cinder.openstack.common.gettextutils import _
|
|
from cinder.openstack.common import log as logging
|
|
from cinder.openstack.common import processutils as putils
|
|
from cinder.openstack.common import units
|
|
from cinder.volume import driver
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
nas_opts = [
|
|
cfg.StrOpt('nas_ip',
|
|
default='',
|
|
help='IP address or Hostname of NAS system.'),
|
|
cfg.StrOpt('nas_login',
|
|
default='admin',
|
|
help='User name to connect to NAS system.'),
|
|
cfg.StrOpt('nas_password',
|
|
default='',
|
|
help='Password to connect to NAS system.',
|
|
secret=True),
|
|
cfg.IntOpt('nas_ssh_port',
|
|
default=22,
|
|
help='SSH port to use to connect to NAS system.'),
|
|
cfg.StrOpt('nas_private_key',
|
|
default='',
|
|
help='Filename of private key to use for SSH authentication.'),
|
|
]
|
|
|
|
CONF = cfg.CONF
|
|
CONF.register_opts(nas_opts)
|
|
|
|
|
|
class RemoteFSDriver(driver.VolumeDriver):
|
|
"""Common base for drivers that work like NFS."""
|
|
|
|
driver_volume_type = None
|
|
driver_prefix = None
|
|
volume_backend_name = None
|
|
SHARE_FORMAT_REGEX = r'.+:/.+'
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(RemoteFSDriver, self).__init__(*args, **kwargs)
|
|
self.shares = {}
|
|
self._mounted_shares = []
|
|
|
|
def check_for_setup_error(self):
|
|
"""Just to override parent behavior."""
|
|
pass
|
|
|
|
def initialize_connection(self, volume, connector):
|
|
"""Allow connection to connector and return connection info.
|
|
|
|
:param volume: volume reference
|
|
:param connector: connector reference
|
|
"""
|
|
data = {'export': volume['provider_location'],
|
|
'name': volume['name']}
|
|
if volume['provider_location'] in self.shares:
|
|
data['options'] = self.shares[volume['provider_location']]
|
|
return {
|
|
'driver_volume_type': self.driver_volume_type,
|
|
'data': data,
|
|
'mount_point_base': self._get_mount_point_base()
|
|
}
|
|
|
|
def _get_mount_point_base(self):
|
|
"""Returns the mount point base for the remote fs.
|
|
|
|
This method facilitates returning mount point base
|
|
for the specific remote fs. Override this method
|
|
in the respective driver to return the entry to be
|
|
used while attach/detach using brick in cinder.
|
|
If not overridden then it returns None without
|
|
raising exception to continue working for cases
|
|
when not used with brick.
|
|
"""
|
|
LOG.debug("Driver specific implementation needs to return"
|
|
" mount_point_base.")
|
|
return None
|
|
|
|
def create_volume(self, volume):
|
|
"""Creates a volume.
|
|
|
|
:param volume: volume reference
|
|
"""
|
|
self._ensure_shares_mounted()
|
|
|
|
volume['provider_location'] = self._find_share(volume['size'])
|
|
|
|
LOG.info(_('casted to %s') % volume['provider_location'])
|
|
|
|
self._do_create_volume(volume)
|
|
|
|
return {'provider_location': volume['provider_location']}
|
|
|
|
def _do_create_volume(self, volume):
|
|
"""Create a volume on given remote share.
|
|
|
|
:param volume: volume reference
|
|
"""
|
|
volume_path = self.local_path(volume)
|
|
volume_size = volume['size']
|
|
|
|
if getattr(self.configuration,
|
|
self.driver_prefix + '_sparsed_volumes'):
|
|
self._create_sparsed_file(volume_path, volume_size)
|
|
else:
|
|
self._create_regular_file(volume_path, volume_size)
|
|
|
|
self._set_rw_permissions_for_all(volume_path)
|
|
|
|
def _ensure_shares_mounted(self):
|
|
"""Look for remote shares in the flags and tries to mount them
|
|
locally.
|
|
"""
|
|
mounted_shares = []
|
|
|
|
self._load_shares_config(getattr(self.configuration,
|
|
self.driver_prefix +
|
|
'_shares_config'))
|
|
|
|
for share in self.shares.keys():
|
|
try:
|
|
self._ensure_share_mounted(share)
|
|
mounted_shares.append(share)
|
|
except Exception as exc:
|
|
LOG.error(_('Exception during mounting %s') % (exc,))
|
|
|
|
self._mounted_shares = mounted_shares
|
|
|
|
LOG.debug('Available shares %s' % self._mounted_shares)
|
|
|
|
def create_cloned_volume(self, volume, src_vref):
|
|
raise NotImplementedError()
|
|
|
|
def delete_volume(self, volume):
|
|
"""Deletes a logical volume.
|
|
|
|
:param volume: volume reference
|
|
"""
|
|
if not volume['provider_location']:
|
|
LOG.warn(_('Volume %s does not have provider_location specified, '
|
|
'skipping'), volume['name'])
|
|
return
|
|
|
|
self._ensure_share_mounted(volume['provider_location'])
|
|
|
|
mounted_path = self.local_path(volume)
|
|
|
|
self._delete(mounted_path)
|
|
|
|
def ensure_export(self, ctx, volume):
|
|
"""Synchronously recreates an export for a logical volume."""
|
|
self._ensure_share_mounted(volume['provider_location'])
|
|
|
|
def create_export(self, ctx, volume):
|
|
"""Exports the volume. Can optionally return a Dictionary of changes
|
|
to the volume object to be persisted.
|
|
"""
|
|
pass
|
|
|
|
def remove_export(self, ctx, volume):
|
|
"""Removes an export for a logical volume."""
|
|
pass
|
|
|
|
def delete_snapshot(self, snapshot):
|
|
"""Do nothing for this driver, but allow manager to handle deletion
|
|
of snapshot in error state.
|
|
"""
|
|
pass
|
|
|
|
def _delete(self, path):
|
|
# Note(lpetrut): this method is needed in order to provide
|
|
# interoperability with Windows as it will be overridden.
|
|
self._execute('rm', '-f', path, run_as_root=True)
|
|
|
|
def _create_sparsed_file(self, path, size):
|
|
"""Creates file with 0 disk usage."""
|
|
self._execute('truncate', '-s', '%sG' % size,
|
|
path, run_as_root=True)
|
|
|
|
def _create_regular_file(self, path, size):
|
|
"""Creates regular file of given size. Takes a lot of time for large
|
|
files.
|
|
"""
|
|
|
|
block_size_mb = 1
|
|
block_count = size * units.Gi / (block_size_mb * units.Mi)
|
|
|
|
self._execute('dd', 'if=/dev/zero', 'of=%s' % path,
|
|
'bs=%dM' % block_size_mb,
|
|
'count=%d' % block_count,
|
|
run_as_root=True)
|
|
|
|
def _create_qcow2_file(self, path, size_gb):
|
|
"""Creates a QCOW2 file of a given size."""
|
|
|
|
self._execute('qemu-img', 'create', '-f', 'qcow2',
|
|
'-o', 'preallocation=metadata',
|
|
path, str(size_gb * units.Gi),
|
|
run_as_root=True)
|
|
|
|
def _set_rw_permissions_for_all(self, path):
|
|
"""Sets 666 permissions for the path."""
|
|
self._execute('chmod', 'ugo+rw', path, run_as_root=True)
|
|
|
|
def _set_rw_permissions_for_owner(self, path):
|
|
"""Sets read-write permissions to the owner for the path."""
|
|
self._execute('chmod', 'u+rw', path, run_as_root=True)
|
|
|
|
def local_path(self, volume):
|
|
"""Get volume path (mounted locally fs path) for given volume
|
|
:param volume: volume reference
|
|
"""
|
|
remotefs_share = volume['provider_location']
|
|
return os.path.join(self._get_mount_point_for_share(remotefs_share),
|
|
volume['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),
|
|
self.configuration.volume_dd_blocksize,
|
|
size=volume['size'])
|
|
|
|
# NOTE (leseb): Set the virtual size of the image
|
|
# the raw conversion overwrote the destination file
|
|
# (which had the correct size)
|
|
# with the fetched glance image size,
|
|
# thus the initial 'size' parameter is not honored
|
|
# this sets the size to the one asked in the first place by the user
|
|
# and then verify the final virtual size
|
|
image_utils.resize_image(self.local_path(volume), volume['size'])
|
|
|
|
data = image_utils.qemu_img_info(self.local_path(volume))
|
|
virt_size = data.virtual_size / units.Gi
|
|
if virt_size != volume['size']:
|
|
raise exception.ImageUnacceptable(
|
|
image_id=image_id,
|
|
reason=(_("Expected volume size was %d") % volume['size'])
|
|
+ (_(" but size is now %d") % virt_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))
|
|
|
|
def _read_config_file(self, config_file):
|
|
# Returns list of lines in file
|
|
with open(config_file) as f:
|
|
return f.readlines()
|
|
|
|
def _load_shares_config(self, share_file):
|
|
self.shares = {}
|
|
|
|
for share in self._read_config_file(share_file):
|
|
# A configuration line may be either:
|
|
# host:/vol_name
|
|
# or
|
|
# host:/vol_name -o options=123,rw --other
|
|
if not share.strip():
|
|
# Skip blank or whitespace-only lines
|
|
continue
|
|
if share.startswith('#'):
|
|
continue
|
|
|
|
share_info = share.split(' ', 1)
|
|
# results in share_info =
|
|
# [ 'address:/vol', '-o options=123,rw --other' ]
|
|
|
|
share_address = share_info[0].strip().decode('unicode_escape')
|
|
share_opts = share_info[1].strip() if len(share_info) > 1 else None
|
|
|
|
if not re.match(self.SHARE_FORMAT_REGEX, share_address):
|
|
LOG.warn(_("Share %s ignored due to invalid format. Must be "
|
|
"of form address:/export.") % share_address)
|
|
continue
|
|
|
|
self.shares[share_address] = share_opts
|
|
|
|
LOG.debug("shares loaded: %s", self.shares)
|
|
|
|
def _get_mount_point_for_share(self, path):
|
|
raise NotImplementedError()
|
|
|
|
def terminate_connection(self, volume, connector, **kwargs):
|
|
"""Disallow connection from connector."""
|
|
pass
|
|
|
|
def get_volume_stats(self, refresh=False):
|
|
"""Get volume stats.
|
|
|
|
If 'refresh' is True, update the stats first.
|
|
"""
|
|
if refresh or not self._stats:
|
|
self._update_volume_stats()
|
|
|
|
return self._stats
|
|
|
|
def _update_volume_stats(self):
|
|
"""Retrieve stats info from volume group."""
|
|
|
|
data = {}
|
|
backend_name = self.configuration.safe_get('volume_backend_name')
|
|
data['volume_backend_name'] = backend_name or self.volume_backend_name
|
|
data['vendor_name'] = 'Open Source'
|
|
data['driver_version'] = self.get_version()
|
|
data['storage_protocol'] = self.driver_volume_type
|
|
|
|
self._ensure_shares_mounted()
|
|
|
|
global_capacity = 0
|
|
global_free = 0
|
|
for share in self._mounted_shares:
|
|
capacity, free, used = self._get_capacity_info(share)
|
|
global_capacity += capacity
|
|
global_free += free
|
|
|
|
data['total_capacity_gb'] = global_capacity / float(units.Gi)
|
|
data['free_capacity_gb'] = global_free / float(units.Gi)
|
|
data['reserved_percentage'] = 0
|
|
data['QoS_support'] = False
|
|
self._stats = data
|
|
|
|
def _do_mount(self, cmd, ensure, share):
|
|
"""Finalize mount command.
|
|
|
|
:param cmd: command to do the actual mount
|
|
:param ensure: boolean to allow remounting a share with a warning
|
|
:param share: description of the share for error reporting
|
|
"""
|
|
try:
|
|
self._execute(*cmd, run_as_root=True)
|
|
except putils.ProcessExecutionError as exc:
|
|
if ensure and 'already mounted' in exc.stderr:
|
|
LOG.warn(_("%s is already mounted"), share)
|
|
else:
|
|
raise
|
|
|
|
def _get_capacity_info(self, share):
|
|
raise NotImplementedError()
|
|
|
|
def _find_share(self, volume_size_in_gib):
|
|
raise NotImplementedError()
|
|
|
|
def _ensure_share_mounted(self, share):
|
|
raise NotImplementedError()
|
|
|
|
|
|
class RemoteFSSnapDriver(RemoteFSDriver):
|
|
"""Base class for remotefs drivers implementing qcow2 snapshots.
|
|
|
|
Driver must implement:
|
|
_local_volume_dir(self, volume)
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self._remotefsclient = None
|
|
self.base = None
|
|
super(RemoteFSSnapDriver, self).__init__(*args, **kwargs)
|
|
|
|
def _local_volume_dir(self, volume):
|
|
share = volume['provider_location']
|
|
local_dir = self._get_mount_point_for_share(share)
|
|
return local_dir
|
|
|
|
def _local_path_volume(self, volume):
|
|
path_to_disk = os.path.join(
|
|
self._local_volume_dir(volume),
|
|
volume['name'])
|
|
|
|
return path_to_disk
|
|
|
|
def _get_new_snap_path(self, snapshot):
|
|
vol_path = self.local_path(snapshot['volume'])
|
|
snap_path = '%s.%s' % (vol_path, snapshot['id'])
|
|
return snap_path
|
|
|
|
def _local_path_volume_info(self, volume):
|
|
return '%s%s' % (self.local_path(volume), '.info')
|
|
|
|
def _read_file(self, filename):
|
|
"""This method is to make it easier to stub out code for testing.
|
|
|
|
Returns a string representing the contents of the file.
|
|
"""
|
|
|
|
with open(filename, 'r') as f:
|
|
return f.read()
|
|
|
|
def _write_info_file(self, info_path, snap_info):
|
|
if 'active' not in snap_info.keys():
|
|
msg = _("'active' must be present when writing snap_info.")
|
|
raise exception.RemoteFSException(msg)
|
|
|
|
with open(info_path, 'w') as f:
|
|
json.dump(snap_info, f, indent=1, sort_keys=True)
|
|
|
|
def _qemu_img_info_base(self, path, volume_name, basedir):
|
|
"""Sanitize image_utils' qemu_img_info.
|
|
|
|
This code expects to deal only with relative filenames.
|
|
"""
|
|
|
|
info = image_utils.qemu_img_info(path)
|
|
if info.image:
|
|
info.image = os.path.basename(info.image)
|
|
if info.backing_file:
|
|
backing_file_template = \
|
|
"(%(basedir)s/[0-9a-f]+/)?%" \
|
|
"(volname)s(.(tmp-snap-)?[0-9a-f-]+)?$" % {
|
|
'basedir': basedir,
|
|
'volname': volume_name
|
|
}
|
|
if not re.match(backing_file_template, info.backing_file):
|
|
msg = _("File %(path)s has invalid backing file "
|
|
"%(bfile)s, aborting.") % {'path': path,
|
|
'bfile': info.backing_file}
|
|
raise exception.RemoteFSException(msg)
|
|
|
|
info.backing_file = os.path.basename(info.backing_file)
|
|
|
|
return info
|
|
|
|
def _qemu_img_info(self, path, volume_name):
|
|
raise NotImplementedError()
|
|
|
|
def _img_commit(self, path):
|
|
self._execute('qemu-img', 'commit', path, run_as_root=True)
|
|
self._delete(path)
|
|
|
|
def _rebase_img(self, image, backing_file, volume_format):
|
|
self._execute('qemu-img', 'rebase', '-u', '-b', backing_file, image,
|
|
'-F', volume_format, run_as_root=True)
|
|
|
|
def _read_info_file(self, info_path, empty_if_missing=False):
|
|
"""Return dict of snapshot information.
|
|
|
|
:param: info_path: path to file
|
|
:param: empty_if_missing: True=return empty dict if no file
|
|
"""
|
|
|
|
if not os.path.exists(info_path):
|
|
if empty_if_missing is True:
|
|
return {}
|
|
|
|
return json.loads(self._read_file(info_path))
|
|
|
|
def _get_backing_chain_for_path(self, volume, path):
|
|
"""Returns list of dicts containing backing-chain information.
|
|
|
|
Includes 'filename', and 'backing-filename' for each
|
|
applicable entry.
|
|
|
|
Consider converting this to use --backing-chain and --output=json
|
|
when environment supports qemu-img 1.5.0.
|
|
|
|
:param volume: volume reference
|
|
:param path: path to image file at top of chain
|
|
|
|
"""
|
|
|
|
output = []
|
|
|
|
info = self._qemu_img_info(path, volume['name'])
|
|
new_info = {}
|
|
new_info['filename'] = os.path.basename(path)
|
|
new_info['backing-filename'] = info.backing_file
|
|
|
|
output.append(new_info)
|
|
|
|
while new_info['backing-filename']:
|
|
filename = new_info['backing-filename']
|
|
path = os.path.join(self._local_volume_dir(volume), filename)
|
|
info = self._qemu_img_info(path, volume['name'])
|
|
backing_filename = info.backing_file
|
|
new_info = {}
|
|
new_info['filename'] = filename
|
|
new_info['backing-filename'] = backing_filename
|
|
|
|
output.append(new_info)
|
|
|
|
return output
|
|
|
|
def _get_hash_str(self, base_str):
|
|
"""Return a string that represents hash of base_str
|
|
(in a hex format).
|
|
"""
|
|
return hashlib.md5(base_str).hexdigest()
|
|
|
|
def _get_mount_point_for_share(self, share):
|
|
"""Return mount point for share.
|
|
:param share: example 172.18.194.100:/var/fs
|
|
"""
|
|
return self._remotefsclient.get_mount_point(share)
|
|
|
|
def _get_available_capacity(self, share):
|
|
"""Calculate available space on the share.
|
|
:param share: example 172.18.194.100:/var/fs
|
|
"""
|
|
mount_point = self._get_mount_point_for_share(share)
|
|
|
|
out, _ = self._execute('df', '--portability', '--block-size', '1',
|
|
mount_point, run_as_root=True)
|
|
out = out.splitlines()[1]
|
|
|
|
size = int(out.split()[1])
|
|
available = int(out.split()[3])
|
|
|
|
return available, size
|
|
|
|
def _get_capacity_info(self, remotefs_share):
|
|
available, size = self._get_available_capacity(remotefs_share)
|
|
return size, available, size - available
|
|
|
|
def _get_mount_point_base(self):
|
|
return self.base
|
|
|
|
def _ensure_share_writable(self, path):
|
|
"""Ensure that the Cinder user can write to the share.
|
|
|
|
If not, raise an exception.
|
|
|
|
:param path: path to test
|
|
:raises: RemoteFSException
|
|
:returns: None
|
|
"""
|
|
|
|
prefix = '.cinder-write-test-' + str(os.getpid()) + '-'
|
|
|
|
try:
|
|
tempfile.NamedTemporaryFile(prefix=prefix, dir=path)
|
|
except OSError:
|
|
msg = _('Share at %(dir)s is not writable by the '
|
|
'Cinder volume service. Snapshot operations will not be '
|
|
'supported.') % {'dir': path}
|
|
raise exception.RemoteFSException(msg)
|
|
|
|
def _copy_volume_to_image(self, context, volume, image_service,
|
|
image_meta):
|
|
"""Copy the volume to the specified image."""
|
|
|
|
# If snapshots exist, flatten to a temporary image, and upload it
|
|
|
|
active_file = self.get_active_image_from_info(volume)
|
|
active_file_path = os.path.join(self._local_volume_dir(volume),
|
|
active_file)
|
|
info = self._qemu_img_info(active_file_path, volume['name'])
|
|
backing_file = info.backing_file
|
|
|
|
root_file_fmt = info.file_format
|
|
|
|
tmp_params = {
|
|
'prefix': '%s.temp_image.%s' % (volume['id'], image_meta['id']),
|
|
'suffix': '.img'
|
|
}
|
|
with image_utils.temporary_file(**tmp_params) as temp_path:
|
|
if backing_file or (root_file_fmt != 'raw'):
|
|
# Convert due to snapshots
|
|
# or volume data not being stored in raw format
|
|
# (upload_volume assumes raw format input)
|
|
image_utils.convert_image(active_file_path, temp_path, 'raw')
|
|
upload_path = temp_path
|
|
else:
|
|
upload_path = active_file_path
|
|
|
|
image_utils.upload_volume(context,
|
|
image_service,
|
|
image_meta,
|
|
upload_path)
|
|
|
|
def get_active_image_from_info(self, volume):
|
|
"""Returns filename of the active image from the info file."""
|
|
|
|
info_file = self._local_path_volume_info(volume)
|
|
|
|
snap_info = self._read_info_file(info_file, empty_if_missing=True)
|
|
|
|
if not snap_info:
|
|
# No info file = no snapshots exist
|
|
vol_path = os.path.basename(self.local_path(volume))
|
|
return vol_path
|
|
|
|
return snap_info['active']
|
|
|
|
def _create_cloned_volume(self, volume, src_vref):
|
|
LOG.info(_('Cloning volume %(src)s to volume %(dst)s') %
|
|
{'src': src_vref['id'],
|
|
'dst': volume['id']})
|
|
|
|
if src_vref['status'] != 'available':
|
|
msg = _("Volume status must be 'available'.")
|
|
raise exception.InvalidVolume(msg)
|
|
|
|
volume_name = CONF.volume_name_template % volume['id']
|
|
|
|
volume_info = {'provider_location': src_vref['provider_location'],
|
|
'size': src_vref['size'],
|
|
'id': volume['id'],
|
|
'name': volume_name,
|
|
'status': src_vref['status']}
|
|
temp_snapshot = {'volume_name': volume_name,
|
|
'size': src_vref['size'],
|
|
'volume_size': src_vref['size'],
|
|
'name': 'clone-snap-%s' % src_vref['id'],
|
|
'volume_id': src_vref['id'],
|
|
'id': 'tmp-snap-%s' % src_vref['id'],
|
|
'volume': src_vref}
|
|
self._create_snapshot(temp_snapshot)
|
|
try:
|
|
self._copy_volume_from_snapshot(temp_snapshot,
|
|
volume_info,
|
|
volume['size'])
|
|
|
|
finally:
|
|
self._delete_snapshot(temp_snapshot)
|
|
|
|
return {'provider_location': src_vref['provider_location']}
|
|
|
|
def _delete_stale_snapshot(self, snapshot):
|
|
info_path = self._local_path_volume_info(snapshot['volume'])
|
|
snap_info = self._read_info_file(info_path)
|
|
|
|
snapshot_file = snap_info[snapshot['id']]
|
|
active_file = self.get_active_image_from_info(snapshot['volume'])
|
|
snapshot_path = os.path.join(
|
|
self._local_volume_dir(snapshot['volume']), snapshot_file)
|
|
if (snapshot_file == active_file):
|
|
return
|
|
|
|
LOG.info(_('Deleting stale snapshot: %s') % snapshot['id'])
|
|
self._delete(snapshot_path)
|
|
del(snap_info[snapshot['id']])
|
|
self._write_info_file(info_path, snap_info)
|
|
|
|
def _delete_snapshot(self, snapshot):
|
|
"""Delete a snapshot.
|
|
|
|
If volume status is 'available', delete snapshot here in Cinder
|
|
using qemu-img.
|
|
|
|
If volume status is 'in-use', calculate what qcow2 files need to
|
|
merge, and call to Nova to perform this operation.
|
|
|
|
:raises: InvalidVolume if status not acceptable
|
|
:raises: RemotefsException(msg) if operation fails
|
|
:returns: None
|
|
|
|
"""
|
|
|
|
LOG.debug('Deleting snapshot %s:' % snapshot['id'])
|
|
|
|
volume_status = snapshot['volume']['status']
|
|
if volume_status not in ['available', 'in-use']:
|
|
msg = _('Volume status must be "available" or "in-use".')
|
|
raise exception.InvalidVolume(msg)
|
|
|
|
self._ensure_share_writable(
|
|
self._local_volume_dir(snapshot['volume']))
|
|
|
|
# Determine the true snapshot file for this snapshot
|
|
# based on the .info file
|
|
info_path = self._local_path_volume_info(snapshot['volume'])
|
|
snap_info = self._read_info_file(info_path, empty_if_missing=True)
|
|
|
|
if snapshot['id'] not in snap_info:
|
|
# If snapshot info file is present, but snapshot record does not
|
|
# exist, do not attempt to delete.
|
|
# (This happens, for example, if snapshot_create failed due to lack
|
|
# of permission to write to the share.)
|
|
LOG.info(_('Snapshot record for %s is not present, allowing '
|
|
'snapshot_delete to proceed.') % snapshot['id'])
|
|
return
|
|
|
|
snapshot_file = snap_info[snapshot['id']]
|
|
LOG.debug('snapshot_file for this snap is: %s' % snapshot_file)
|
|
snapshot_path = os.path.join(
|
|
self._local_volume_dir(snapshot['volume']),
|
|
snapshot_file)
|
|
|
|
snapshot_path_img_info = self._qemu_img_info(
|
|
snapshot_path,
|
|
snapshot['volume']['name'])
|
|
|
|
vol_path = self._local_volume_dir(snapshot['volume'])
|
|
|
|
# Find what file has this as its backing file
|
|
active_file = self.get_active_image_from_info(snapshot['volume'])
|
|
active_file_path = os.path.join(vol_path, active_file)
|
|
|
|
if volume_status == 'in-use':
|
|
# Online delete
|
|
context = snapshot['context']
|
|
|
|
base_file = snapshot_path_img_info.backing_file
|
|
if base_file is None:
|
|
# There should always be at least the original volume
|
|
# file as base.
|
|
msg = _('No backing file found for %s, allowing snapshot '
|
|
'to be deleted.') % snapshot_path
|
|
LOG.warn(msg)
|
|
|
|
# Snapshot may be stale, so just delete it and update ther
|
|
# info file instead of blocking
|
|
return self._delete_stale_snapshot(snapshot)
|
|
|
|
base_path = os.path.join(
|
|
self._local_volume_dir(snapshot['volume']), base_file)
|
|
base_file_img_info = self._qemu_img_info(
|
|
base_path,
|
|
snapshot['volume']['name'])
|
|
new_base_file = base_file_img_info.backing_file
|
|
|
|
base_id = None
|
|
for key, value in snap_info.iteritems():
|
|
if value == base_file and key != 'active':
|
|
base_id = key
|
|
break
|
|
if base_id is None:
|
|
# This means we are deleting the oldest snapshot
|
|
msg = 'No %(base_id)s found for %(file)s' % {
|
|
'base_id': 'base_id',
|
|
'file': snapshot_file}
|
|
LOG.debug(msg)
|
|
|
|
online_delete_info = {
|
|
'active_file': active_file,
|
|
'snapshot_file': snapshot_file,
|
|
'base_file': base_file,
|
|
'base_id': base_id,
|
|
'new_base_file': new_base_file
|
|
}
|
|
|
|
return self._delete_snapshot_online(context,
|
|
snapshot,
|
|
online_delete_info)
|
|
|
|
if snapshot_file == active_file:
|
|
# Need to merge snapshot_file into its backing file
|
|
# There is no top file
|
|
# T0 | T1 |
|
|
# base | snapshot_file | None
|
|
# (guaranteed to| (being deleted) |
|
|
# exist) | |
|
|
|
|
base_file = snapshot_path_img_info.backing_file
|
|
|
|
self._img_commit(snapshot_path)
|
|
|
|
# Remove snapshot_file from info
|
|
del(snap_info[snapshot['id']])
|
|
# Active file has changed
|
|
snap_info['active'] = base_file
|
|
self._write_info_file(info_path, snap_info)
|
|
else:
|
|
# T0 | T1 | T2 | T3
|
|
# base | snapshot_file | higher_file | highest_file
|
|
# (guaranteed to | (being deleted)|(guaranteed to | (may exist,
|
|
# exist, not | | exist, being | needs ptr
|
|
# used here) | | committed down)| update if so)
|
|
|
|
backing_chain = self._get_backing_chain_for_path(
|
|
snapshot['volume'], active_file_path)
|
|
# This file is guaranteed to exist since we aren't operating on
|
|
# the active file.
|
|
higher_file = next((os.path.basename(f['filename'])
|
|
for f in backing_chain
|
|
if f.get('backing-filename', '') ==
|
|
snapshot_file),
|
|
None)
|
|
if higher_file is None:
|
|
msg = _('No file found with %s as backing file.') %\
|
|
snapshot_file
|
|
raise exception.RemoteFSException(msg)
|
|
|
|
higher_id = next((i for i in snap_info
|
|
if snap_info[i] == higher_file
|
|
and i != 'active'),
|
|
None)
|
|
if higher_id is None:
|
|
msg = _('No snap found with %s as backing file.') %\
|
|
higher_file
|
|
raise exception.RemoteFSException(msg)
|
|
|
|
# Is there a file depending on higher_file?
|
|
highest_file = next((os.path.basename(f['filename'])
|
|
for f in backing_chain
|
|
if f.get('backing-filename', '') ==
|
|
higher_file),
|
|
None)
|
|
if highest_file is None:
|
|
msg = 'No file depends on %s.' % higher_file
|
|
LOG.debug(msg)
|
|
|
|
# Committing higher_file into snapshot_file
|
|
# And update pointer in highest_file
|
|
higher_file_path = os.path.join(vol_path, higher_file)
|
|
self._img_commit(higher_file_path)
|
|
if highest_file is not None:
|
|
highest_file_path = os.path.join(vol_path, highest_file)
|
|
snapshot_file_fmt = snapshot_path_img_info.file_format
|
|
self._rebase_img(highest_file_path, snapshot_file,
|
|
snapshot_file_fmt)
|
|
|
|
# Remove snapshot_file from info
|
|
del(snap_info[snapshot['id']])
|
|
snap_info[higher_id] = snapshot_file
|
|
if higher_file == active_file:
|
|
if highest_file is not None:
|
|
msg = _('Check condition failed: '
|
|
'%s expected to be None.') % 'highest_file'
|
|
raise exception.RemoteFSException(msg)
|
|
# Active file has changed
|
|
snap_info['active'] = snapshot_file
|
|
|
|
self._write_info_file(info_path, snap_info)
|
|
|
|
def _create_volume_from_snapshot(self, volume, snapshot):
|
|
"""Creates a volume from a snapshot.
|
|
|
|
Snapshot must not be the active snapshot. (offline)
|
|
"""
|
|
|
|
if snapshot['status'] != 'available':
|
|
msg = _('Snapshot status must be "available" to clone.')
|
|
raise exception.InvalidSnapshot(msg)
|
|
|
|
self._ensure_shares_mounted()
|
|
|
|
volume['provider_location'] = self._find_share(volume['size'])
|
|
|
|
self._do_create_volume(volume)
|
|
|
|
self._copy_volume_from_snapshot(snapshot,
|
|
volume,
|
|
volume['size'])
|
|
|
|
return {'provider_location': volume['provider_location']}
|
|
|
|
def _copy_volume_from_snapshot(self, snapshot, volume, volume_size):
|
|
raise NotImplementedError()
|
|
|
|
def _do_create_snapshot(self, snapshot, backing_filename,
|
|
new_snap_path):
|
|
"""Create a QCOW2 file backed by another file.
|
|
|
|
:param snapshot: snapshot reference
|
|
:param backing_filename: filename of file that will back the
|
|
new qcow2 file
|
|
:param new_snap_path: filename of new qcow2 file
|
|
"""
|
|
|
|
backing_path_full_path = os.path.join(
|
|
self._local_volume_dir(snapshot['volume']),
|
|
backing_filename)
|
|
|
|
command = ['qemu-img', 'create', '-f', 'qcow2', '-o',
|
|
'backing_file=%s' % backing_path_full_path, new_snap_path]
|
|
self._execute(*command, run_as_root=True)
|
|
|
|
info = self._qemu_img_info(backing_path_full_path,
|
|
snapshot['volume']['name'])
|
|
backing_fmt = info.file_format
|
|
|
|
command = ['qemu-img', 'rebase', '-u',
|
|
'-b', backing_filename,
|
|
'-F', backing_fmt,
|
|
new_snap_path]
|
|
self._execute(*command, run_as_root=True)
|
|
|
|
self._set_rw_permissions_for_all(new_snap_path)
|
|
|
|
def _create_snapshot(self, snapshot):
|
|
"""Create a snapshot.
|
|
|
|
If volume is attached, call to Nova to create snapshot,
|
|
providing a qcow2 file.
|
|
Otherwise, create locally with qemu-img.
|
|
|
|
A file named volume-<uuid>.info is stored with the volume
|
|
data and is a JSON table which contains a mapping between
|
|
Cinder snapshot UUIDs and filenames, as these associations
|
|
will change as snapshots are deleted.
|
|
|
|
|
|
Basic snapshot operation:
|
|
|
|
1. Initial volume file:
|
|
volume-1234
|
|
|
|
2. Snapshot created:
|
|
volume-1234 <- volume-1234.aaaa
|
|
|
|
volume-1234.aaaa becomes the new "active" disk image.
|
|
If the volume is not attached, this filename will be used to
|
|
attach the volume to a VM at volume-attach time.
|
|
If the volume is attached, the VM will switch to this file as
|
|
part of the snapshot process.
|
|
|
|
Note that volume-1234.aaaa represents changes after snapshot
|
|
'aaaa' was created. So the data for snapshot 'aaaa' is actually
|
|
in the backing file(s) of volume-1234.aaaa.
|
|
|
|
This file has a qcow2 header recording the fact that volume-1234 is
|
|
its backing file. Delta changes since the snapshot was created are
|
|
stored in this file, and the backing file (volume-1234) does not
|
|
change.
|
|
|
|
info file: { 'active': 'volume-1234.aaaa',
|
|
'aaaa': 'volume-1234.aaaa' }
|
|
|
|
3. Second snapshot created:
|
|
volume-1234 <- volume-1234.aaaa <- volume-1234.bbbb
|
|
|
|
volume-1234.bbbb now becomes the "active" disk image, recording
|
|
changes made to the volume.
|
|
|
|
info file: { 'active': 'volume-1234.bbbb',
|
|
'aaaa': 'volume-1234.aaaa',
|
|
'bbbb': 'volume-1234.bbbb' }
|
|
|
|
4. First snapshot deleted:
|
|
volume-1234 <- volume-1234.aaaa(* now with bbbb's data)
|
|
|
|
volume-1234.aaaa is removed (logically) from the snapshot chain.
|
|
The data from volume-1234.bbbb is merged into it.
|
|
|
|
(*) Since bbbb's data was committed into the aaaa file, we have
|
|
"removed" aaaa's snapshot point but the .aaaa file now
|
|
represents snapshot with id "bbbb".
|
|
|
|
|
|
info file: { 'active': 'volume-1234.bbbb',
|
|
'bbbb': 'volume-1234.aaaa' (* changed!)
|
|
}
|
|
|
|
5. Second snapshot deleted:
|
|
volume-1234
|
|
|
|
volume-1234.bbbb is removed from the snapshot chain, as above.
|
|
The base image, volume-1234, becomes the active image for this
|
|
volume again. If in-use, the VM begins using the volume-1234.bbbb
|
|
file immediately as part of the snapshot delete process.
|
|
|
|
info file: { 'active': 'volume-1234' }
|
|
|
|
For the above operations, Cinder handles manipulation of qcow2 files
|
|
when the volume is detached. When attached, Cinder creates and deletes
|
|
qcow2 files, but Nova is responsible for transitioning the VM between
|
|
them and handling live transfers of data between files as required.
|
|
"""
|
|
|
|
status = snapshot['volume']['status']
|
|
if status not in ['available', 'in-use']:
|
|
msg = _('Volume status must be "available" or "in-use"'
|
|
' for snapshot. (is %s)') % status
|
|
raise exception.InvalidVolume(msg)
|
|
|
|
info_path = self._local_path_volume_info(snapshot['volume'])
|
|
snap_info = self._read_info_file(info_path, empty_if_missing=True)
|
|
backing_filename = self.get_active_image_from_info(
|
|
snapshot['volume'])
|
|
new_snap_path = self._get_new_snap_path(snapshot)
|
|
|
|
if status == 'in-use':
|
|
self._create_snapshot_online(snapshot,
|
|
backing_filename,
|
|
new_snap_path)
|
|
else:
|
|
self._do_create_snapshot(snapshot,
|
|
backing_filename,
|
|
new_snap_path)
|
|
|
|
snap_info['active'] = os.path.basename(new_snap_path)
|
|
snap_info[snapshot['id']] = os.path.basename(new_snap_path)
|
|
self._write_info_file(info_path, snap_info)
|
|
|
|
def _create_snapshot_online(self, snapshot, backing_filename,
|
|
new_snap_path):
|
|
raise NotImplementedError()
|
|
|
|
def _delete_snapshot_online(self, context, snapshot, info):
|
|
raise NotImplementedError()
|