qubes-installer-qubes-os/storage/deviceaction.py
2011-01-18 04:24:57 -05:00

377 lines
12 KiB
Python

# deviceaction.py
# Device modification action classes for anaconda's storage configuration
# module.
#
# Copyright (C) 2009 Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties 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. Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
#
from udev import *
from devices import StorageDevice, PartitionDevice
from formats import getFormat
from errors import *
from parted import partitionFlag, PARTITION_LBA
import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)
import logging
log = logging.getLogger("storage")
# The values are just hints as to the ordering.
# Eg: fsmod and devmod ordering depends on the mod (shrink -v- grow)
ACTION_TYPE_NONE = 0
ACTION_TYPE_DESTROY = 1000
ACTION_TYPE_RESIZE = 500
ACTION_TYPE_MIGRATE = 250
ACTION_TYPE_CREATE = 100
action_strings = {ACTION_TYPE_NONE: "None",
ACTION_TYPE_DESTROY: "Destroy",
ACTION_TYPE_RESIZE: "Resize",
ACTION_TYPE_MIGRATE: "Migrate",
ACTION_TYPE_CREATE: "Create"}
ACTION_OBJECT_NONE = 0
ACTION_OBJECT_FORMAT = 1
ACTION_OBJECT_DEVICE = 2
object_strings = {ACTION_OBJECT_NONE: "None",
ACTION_OBJECT_FORMAT: "Format",
ACTION_OBJECT_DEVICE: "Device"}
RESIZE_SHRINK = 88
RESIZE_GROW = 89
resize_strings = {RESIZE_SHRINK: "Shrink",
RESIZE_GROW: "Grow"}
def action_type_from_string(type_string):
if type_string is None:
return None
for (k,v) in action_strings.items():
if v.lower() == type_string.lower():
return k
return resize_type_from_string(type_string)
def action_object_from_string(type_string):
if type_string is None:
return None
for (k,v) in object_strings.items():
if v.lower() == type_string.lower():
return k
def resize_type_from_string(type_string):
if type_string is None:
return None
for (k,v) in resize_strings.items():
if v.lower() == type_string.lower():
return k
class DeviceAction(object):
""" An action that will be carried out in the future on a Device.
These classes represent actions to be performed on devices or
filesystems.
The operand Device instance will be modified according to the
action, but no changes will be made to the underlying device or
filesystem until the DeviceAction instance's execute method is
called. The DeviceAction instance's cancel method should reverse
any modifications made to the Device instance's attributes.
If the Device instance represents a pre-existing device, the
constructor should call any methods or set any attributes that the
action will eventually change. Device/DeviceFormat classes should verify
that the requested modifications are reasonable and raise an
exception if not.
Only one action of any given type/object pair can exist for any
given device at any given time. This is enforced by the
DeviceTree.
Basic usage:
a = DeviceAction(dev)
a.execute()
OR
a = DeviceAction(dev)
a.cancel()
XXX should we back up the device with a deep copy for forcibly
cancelling actions?
The downside is that we lose any checking or verification that
would get done when resetting the Device instance's attributes to
their original values.
The upside is that we would be guaranteed to achieve a total
reversal. No chance of, eg: resizes ending up altering Device
size due to rounding or other miscalculation.
"""
type = ACTION_TYPE_NONE
obj = ACTION_OBJECT_NONE
def __init__(self, device):
if not isinstance(device, StorageDevice):
raise ValueError("arg 1 must be a StorageDevice instance")
self.device = device
def execute(self, intf=None):
""" perform the action """
pass
def cancel(self):
""" cancel the action """
pass
def isDestroy(self):
return self.type == ACTION_TYPE_DESTROY
def isCreate(self):
return self.type == ACTION_TYPE_CREATE
def isMigrate(self):
return self.type == ACTION_TYPE_MIGRATE
def isResize(self):
return self.type == ACTION_TYPE_RESIZE
def isShrink(self):
return (self.type == ACTION_TYPE_RESIZE and self.dir == RESIZE_SHRINK)
def isGrow(self):
return (self.type == ACTION_TYPE_RESIZE and self.dir == RESIZE_GROW)
def isDevice(self):
return self.obj == ACTION_OBJECT_DEVICE
def isFormat(self):
return self.obj == ACTION_OBJECT_FORMAT
@property
def format(self):
return self.device.format
def __str__(self):
s = "%s %s" % (action_strings[self.type], object_strings[self.obj])
if self.isResize():
s += " (%s)" % resize_strings[self.dir]
if self.isFormat():
s += " %s on" % self.format.type
if self.isMigrate():
s += " to %s" % self.format.migrationTarget
s += " %s %s (id %d)" % (self.device.type, self.device.name,
self.device.id)
return s
class ActionCreateDevice(DeviceAction):
""" Action representing the creation of a new device. """
type = ACTION_TYPE_CREATE
obj = ACTION_OBJECT_DEVICE
def __init__(self, device):
# FIXME: assert device.fs is None
DeviceAction.__init__(self, device)
def execute(self, intf=None):
self.device.create(intf=intf)
class ActionDestroyDevice(DeviceAction):
""" An action representing the deletion of an existing device. """
type = ACTION_TYPE_DESTROY
obj = ACTION_OBJECT_DEVICE
def __init__(self, device):
# XXX should we insist that device.fs be None?
DeviceAction.__init__(self, device)
if device.exists:
device.teardown()
def execute(self, intf=None):
self.device.destroy()
# Make sure libparted does not keep cached info for this device
# and returns it when we create a new device with the same name
if self.device.partedDevice:
self.device.partedDevice.removeFromCache()
class ActionResizeDevice(DeviceAction):
""" An action representing the resizing of an existing device. """
type = ACTION_TYPE_RESIZE
obj = ACTION_OBJECT_DEVICE
def __init__(self, device, newsize):
if device.currentSize == newsize:
raise ValueError("new size same as old size")
if not device.resizable:
raise ValueError("device is not resizable")
DeviceAction.__init__(self, device)
if newsize > device.currentSize:
self.dir = RESIZE_GROW
else:
self.dir = RESIZE_SHRINK
self.origsize = device.targetSize
self.device.targetSize = newsize
def execute(self, intf=None):
self.device.resize(intf=intf)
def cancel(self):
self.device.targetSize = self.origsize
class ActionCreateFormat(DeviceAction):
""" An action representing creation of a new filesystem. """
type = ACTION_TYPE_CREATE
obj = ACTION_OBJECT_FORMAT
def __init__(self, device, format=None):
DeviceAction.__init__(self, device)
if format:
self.origFormat = device.format
if self.device.format.exists:
self.device.format.teardown()
self.device.format = format
else:
self.origFormat = getFormat(None)
def execute(self, intf=None):
self.device.setup()
if isinstance(self.device, PartitionDevice):
for flag in partitionFlag.keys():
# Keep the LBA flag on pre-existing partitions
if flag in [ PARTITION_LBA, self.format.partedFlag ]:
continue
self.device.unsetFlag(flag)
if self.format.partedFlag is not None:
self.device.setFlag(self.format.partedFlag)
if self.format.partedSystem is not None:
self.device.partedPartition.system = self.format.partedSystem
self.device.disk.format.commitToDisk()
self.device.format.create(intf=intf,
device=self.device.path,
options=self.device.formatArgs)
# Get the UUID now that the format is created
udev_settle()
self.device.updateSysfsPath()
info = udev_get_block_device(self.device.sysfsPath)
self.device.format.uuid = udev_device_get_uuid(info)
def cancel(self):
self.device.format = self.origFormat
class ActionDestroyFormat(DeviceAction):
""" An action representing the removal of an existing filesystem.
XXX this seems unnecessary
"""
type = ACTION_TYPE_DESTROY
obj = ACTION_OBJECT_FORMAT
def __init__(self, device):
DeviceAction.__init__(self, device)
self.origFormat = self.device.format
if device.format.exists:
device.format.teardown()
self.device.format = None
def execute(self, intf=None):
""" wipe the filesystem signature from the device """
if self.origFormat:
self.device.setup(orig=True)
self.origFormat.destroy()
udev_settle()
self.device.teardown()
def cancel(self):
self.device.format = self.origFormat
@property
def format(self):
return self.origFormat
class ActionResizeFormat(DeviceAction):
""" An action representing the resizing of an existing filesystem.
XXX Do we even want to support resizing of a filesystem without
also resizing the device it resides on?
"""
type = ACTION_TYPE_RESIZE
obj = ACTION_OBJECT_FORMAT
def __init__(self, device, newsize):
if device.format.targetSize == newsize:
raise ValueError("new size same as old size")
DeviceAction.__init__(self, device)
if newsize > device.format.currentSize:
self.dir = RESIZE_GROW
else:
self.dir = RESIZE_SHRINK
self.origSize = self.device.format.targetSize
self.device.format.targetSize = newsize
def execute(self, intf=None):
self.device.setup(orig=True)
self.device.format.doResize(intf=intf)
def cancel(self):
self.device.format.targetSize = self.origSize
class ActionMigrateFormat(DeviceAction):
""" An action representing the migration of an existing filesystem. """
type = ACTION_TYPE_MIGRATE
obj = ACTION_OBJECT_FORMAT
def __init__(self, device):
if not device.format.migratable or not device.format.exists:
raise ValueError("device format is not migratable")
DeviceAction.__init__(self, device)
self.device.format.migrate = True
def execute(self, intf=None):
self.device.setup(orig=True)
self.device.format.doMigrate(intf=intf)
def cancel(self):
self.device.format.migrate = False