core-admin/qubes/storage/xen.py
Bahtiar `kalkin-` Gadimov 88238c80f3 Add XenPool._reset_volume
2016-04-25 07:17:17 +02:00

454 lines
16 KiB
Python

#!/usr/bin/python2 -O
# vim: fileencoding=utf-8
#
# The Qubes OS Project, https://www.qubes-os.org/
#
# Copyright (C) 2015 Joanna Rutkowska <joanna@invisiblethingslab.com>
# Copyright (C) 2013-2015 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
# Copyright (C) 2015 Wojtek Porczyk <woju@invisiblethingslab.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
from __future__ import absolute_import
import os
import os.path
import re
import subprocess
import qubes
import qubes.config
import qubes.vm.templatevm
from qubes.storage import Pool, StoragePoolException, Volume
class XenPool(Pool):
root_dev = 'xvda'
private_dev = 'xvdb'
volatile_dev = 'xvdc'
def __init__(self, vm=None, name=None, dir_path=None):
super(XenPool, self).__init__(vm=vm, name=name)
assert dir_path, "No pool dir_path specified"
self.dir_path = os.path.normpath(dir_path)
self.create_dir_if_not_exists(self.dir_path)
appvms_path = os.path.join(self.dir_path, 'appvms')
self.create_dir_if_not_exists(appvms_path)
vm_templates_path = os.path.join(self.dir_path, 'vm-templates')
self.create_dir_if_not_exists(vm_templates_path)
@property
def private_img(self):
'''Path to the private image'''
return self.abspath(qubes.config.vm_files['private_img'])
@property
def root_img(self):
'''Path to the root image'''
return self.vm.template.storage.root_img \
if hasattr(self.vm, 'template') and self.vm.template \
else self.abspath(qubes.config.vm_files['root_img'])
@property
def rootcow_img(self):
'''Path to the root COW image'''
if isinstance(self.vm, qubes.vm.templatevm.TemplateVM):
return self.abspath(qubes.config.vm_files['rootcow_img'])
return None
@property
def volatile_img(self):
'''Path to the volatile image'''
return self.abspath(qubes.config.vm_files['volatile_img'])
def root_dev_config(self):
dev_name = 'root'
if isinstance(self.vm, qubes.vm.templatevm.TemplateVM):
return self.format_disk_dev(
'{root}:{rootcow}'.format(
root=self.root_img,
rootcow=self.rootcow_img),
dev_name,
script='block-origin')
elif self.vm.hvm and hasattr(self.vm, 'template'):
# HVM template-based VM - only one device-mapper layer, in dom0
# (root+volatile)
# HVM detection based on 'kernel' property is massive hack,
# but taken from assumption that VM needs Qubes-specific kernel
# (actually initramfs) to assemble the second layer of device-mapper
return self.format_disk_dev(
'{root}:{volatile}'.format(
root=self.vm.template.storage.root_img,
volatile=self.volatile_img),
dev_name,
script='block-snapshot')
elif hasattr(self.vm, 'template'):
# any other template-based VM - two device-mapper layers: one
# in dom0 (here) from root+root-cow, and another one from
# this+volatile.img
path = '{root}:{template_rootcow}'.format(
root=self.root_img,
template_rootcow=self.vm.template.storage.rootcow_img)
return self.format_disk_dev(path=path,
vdev=self.root_dev,
script='block-snapshot',
rw=False)
else:
# standalone qube
return self.format_disk_dev(self.root_img, dev_name)
def private_dev_config(self):
return self.format_disk_dev(self.private_img, 'private')
def volatile_dev_config(self):
return self.format_disk_dev(self.volatile_img, 'volatile')
def create_on_disk_private_img(self, source_template=None):
if not os.path.exists(self.target_dir):
os.makedirs(self.target_dir)
if source_template is None:
f_private = open(self.private_img, 'a+b')
f_private.truncate(self.private_img_size)
f_private.close()
else:
self.vm.log.info("Copying the template's private image: {}".format(
source_template.storage.private_img))
self._copy_file(source_template.storage.private_img, self.private_img)
def create_on_disk_root_img(self, source_template=None):
if not os.path.exists(self.target_dir):
os.makedirs(self.target_dir)
if source_template is None:
fd = open(self.root_img, 'a+b')
fd.truncate(self.root_img_size)
fd.close()
elif self.vm.updateable:
# if not updateable, just use template's disk
self.vm.log.info(
"--> Copying the template's root image: {}".format(
source_template.storage.root_img))
self._copy_file(source_template.storage.root_img, self.root_img)
def resize_private_img(self, size):
fd = open(self.private_img, 'a+b')
fd.truncate(size)
fd.close()
# find loop device if any
p = subprocess.Popen(
['sudo', 'losetup', '--associated', self.private_img],
stdout=subprocess.PIPE)
result = p.communicate()
m = re.match(r'^(/dev/loop\d+):\s', result[0])
if m is not None:
loop_dev = m.group(1)
# resize loop device
subprocess.check_call(['sudo', 'losetup', '--set-capacity',
loop_dev])
def commit_template_changes(self):
assert isinstance(self.vm, qubes.vm.templatevm.TemplateVM)
# TODO: move rootcow_img to this class; the same for vm.is_outdated()
if os.path.exists(self.vm.rootcow_img):
os.rename(self.vm.rootcow_img, self.vm.rootcow_img + '.old')
old_umask = os.umask(002)
f_cow = open(self.vm.rootcow_img, 'w')
f_root = open(self.root_img, 'r')
f_root.seek(0, os.SEEK_END)
# make empty sparse file of the same size as root.img
f_cow.truncate(f_root.tell())
f_cow.close()
f_root.close()
os.umask(old_umask)
return volume
def start(self, volume):
if volume.volume_type == 'volatile':
self._reset_volume(volume)
return volume
def _reset_volume(self, volume):
''' Remove and recreate a volatile volume '''
assert volume.volume_type == 'volatile', "Not a volatile volume"
size = self.vm.volume_config[volume.name]['size']
assert size
if os.path.exists(volume.path):
os.remove(volume.path)
with open(volume.path, "w") as f_volatile:
f_volatile.truncate(volume.size)
return volume
def reset_volatile_storage(self):
try:
# no template set, in any way (Standalone VM, Template VM)
if self.vm.template is None:
raise AttributeError
# template-based HVM with only one device-mapper layer -
# volatile.img used as upper layer on root.img, no root-cow.img
# intermediate layer
if self.vm.hvm:
if os.path.exists(self.volatile_img):
if self.vm.debug:
if os.path.getmtime(self.vm.template.storage.root_img) \
> os.path.getmtime(self.volatile_img):
self.vm.log.warning(
'Template have changed, resetting root.img')
else:
self.vm.log.warning(
'Debug mode: not resetting root.img; if you'
' want to force root.img reset, either'
' update template VM, or remove volatile.img'
' file.')
return
os.remove(self.volatile_img)
# FIXME stat on f_root; with open() ...
f_volatile = open(self.volatile_img, "w")
f_root = open(self.vm.template.storage.root_img, "r")
# make empty sparse file of the same size as root.img
f_root.seek(0, os.SEEK_END)
f_volatile.truncate(f_root.tell())
f_volatile.close()
f_root.close()
return # XXX why is that? super() does not run
except AttributeError: # self.vm.template
pass
super(XenPool, self).reset_volatile_storage()
def prepare_for_vm_startup(self):
super(XenPool, self).prepare_for_vm_startup()
if self.drive is not None:
# pylint: disable=unused-variable
(drive_type, drive_domain, drive_path) = self.drive.split(":")
if drive_domain.lower() != "dom0":
# XXX "VM '{}' holding '{}' does not exists".format(
drive_vm = self.vm.app.domains[drive_domain]
if not drive_vm.is_running():
raise qubes.exc.QubesVMNotRunningError(
drive_vm, 'VM {!r} holding {!r} isn\'t running'.format(
drive_domain, drive_path))
if self.rootcow_img and not os.path.exists(self.rootcow_img):
self.commit_template_changes()
# XXX there is also a class attribute on the domain classes which does
# exactly that -- which one should prevail?
@property
def target_dir(self):
""" Returns the path to vmdir depending on the type of the VM.
The default QubesOS file storage saves the vm images in three
different directories depending on the ``QubesVM`` type:
* ``appvms`` for ``QubesAppVm`` or ``QubesHvm``
* ``vm-templates`` for ``QubesTemplateVm`` or ``QubesTemplateHvm``
Args:
vm: a QubesVM
pool_dir: the root directory of the pool
Returns:
string (str) absolute path to the directory where the vm files
are stored
"""
vm = self.vm
if vm.is_template():
subdir = 'vm-templates'
elif vm.is_disposablevm():
subdir = 'appvms'
return os.path.join(self.dir_path, subdir,
vm.template.name + '-dvm')
else:
subdir = 'appvms'
return os.path.join(self.dir_path, subdir, vm.name)
def abspath(self, file_name):
return os.path.join(self.target_dir, file_name)
def init_volume(self, volume_config):
assert 'volume_type' in volume_config, "Volume type missing " \
+ str(volume_config)
target_dir = self.target_dir
assert target_dir, "Pool target_dir not set"
volume_type = volume_config['volume_type']
volume_config['target_dir'] = target_dir
known_types = {
'read-write': ReadWriteFile,
'read-only': ReadOnlyFile,
'origin': OriginFile,
'snapshot': SnapshotFile,
'volatile': VolatileFile,
}
if volume_type not in known_types:
raise StoragePoolException("Unknown volume type " + volume_type)
if volume_type == 'snapshot':
path = qubes.storage.get_pool(volume_config['pool'], self.vm.template).target_dir
volume_config['vid'] = os.path.join(path, volume_config['name'] + '.img')
return known_types[volume_type](**volume_config)
class SizeMixIn(Volume):
def __init__(self, name=None, pool=None, vid=None, target_dir=None, size=0,
**kwargs):
assert size > 0, 'Size for volume ' + name + ' is <=0'
super(SizeMixIn, self).__init__(name=name,
pool=pool,
vid=vid,
**kwargs)
self._size = size
self.target_dir = target_dir
@property
def size(self):
if self.vid and os.path.exists(self.vid):
return qubes.storage.get_disk_usage(self.vid)
else:
return self._size
class ReadWriteFile(SizeMixIn):
# :pylint: disable=too-few-public-methods
def __init__(self, **kwargs):
super(ReadWriteFile, self).__init__(**kwargs)
self.path = os.path.join(self.target_dir, self.name + '.img')
self.vid = self.path
@property
def size(self):
if self.vid and os.path.exists(self.vid):
return qubes.storage.get_disk_usage(self.vid)
else:
return self._size
def create(self):
create_file(self.path, self.size)
@property
def created(self):
return os.path.exists(self.path)
class ReadOnlyFile(Volume):
def __init__(self, name=None, pool=None, vid=None, target_dir=None,
**kwargs):
assert os.path.exists(vid), "read-only volume missing vid"
super(ReadOnlyFile, self).__init__(name=name,
pool=pool,
vid=vid,
**kwargs)
self.path = self.vid
@property
def size(self):
return qubes.storage.get_disk_usage(self.vid)
class OriginFile(SizeMixIn):
script = 'block-origin'
def __init__(self, **kwargs):
super(OriginFile, self).__init__(**kwargs)
self.path = os.path.join(self.target_dir, self.name + '.img')
self.path_cow = os.path.join(self.target_dir, self.name + '-cow.img')
self.vid = self.path
def create(self):
create_file(self.path, self.size)
create_file(self.path_cow, self.size)
def commit(self):
raise NotImplementedError
@property
def size(self):
if self.vid and os.path.exists(self.vid):
return qubes.storage.get_disk_usage(self.vid)
else:
return self._size
@property
def created(self):
return os.path.exists(self.path) and os.path.exists(self.path_cow)
class SnapshotFile(Volume):
# :pylint: disable=too-few-public-methods
script = 'block-snapshot'
rw = False
def __init__(self, name=None, pool=None, vid=None, target_dir=None,
**kwargs):
assert vid, "SnapshotVolume missing a vid to OriginVolume"
assert os.path.exists(vid), "OriginVolume does not exist"
super(SnapshotFile, self).__init__(name=name,
pool=pool,
vid=vid,
**kwargs)
self.path = os.path.join(target_dir, name + '.img')
self.path_cow = os.path.join(target_dir, name + '-cow.img')
@property
def created(self):
return os.path.exists(self.path) and os.path.exists(self.path_cow)
@property
def size(self):
return qubes.storage.get_disk_usage(self.vid)
class VolatileFile(SizeMixIn):
def __init__(self, **kwargs):
super(VolatileFile, self).__init__(**kwargs)
self.path = os.path.join(self.target_dir, 'volatile.img')
self.vid = self.path
def create_file(path, size):
if os.path.exists(path):
raise IOError("Volume %s already exists", path)
with open(path, 'a+b') as fh:
fh.truncate(size)