kiwi-el8/kiwi/storage/loop_device.py
Marcus Schäfer bdb7123fa1
Refactor use of logging facility
Use getLogger method instead of a global log object
Also use caplog fixture to capture log messages in
unit tests. This Fixes #1244
2019-10-23 17:54:27 +02:00

107 lines
3.3 KiB
Python

# Copyright (c) 2015 SUSE Linux GmbH. All rights reserved.
#
# This file is part of kiwi.
#
# kiwi 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 3 of the License, or
# (at your option) any later version.
#
# kiwi 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 kiwi. If not, see <http://www.gnu.org/licenses/>
#
import os
import logging
# project
from kiwi.command import Command
from kiwi.storage.device_provider import DeviceProvider
from kiwi.utils.command_capabilities import CommandCapabilities
from kiwi.exceptions import (
KiwiLoopSetupError
)
log = logging.getLogger('kiwi')
class LoopDevice(DeviceProvider):
"""
**Create and manage loop device file for block operations**
:param string filename: loop file name to create
:param int filesize_mbytes: size of the loop file
:param int blocksize_bytes: blocksize used in loop driver
"""
def __init__(self, filename, filesize_mbytes=None, blocksize_bytes=None):
self.node_name = None
if not os.path.exists(filename) and not filesize_mbytes:
raise KiwiLoopSetupError(
'Can not create loop file without a size'
)
self.filename = filename
self.filesize_mbytes = filesize_mbytes
self.blocksize_bytes = blocksize_bytes
def get_device(self):
"""
Device node name
:return: device node name
:rtype: str
"""
return self.node_name
def is_loop(self):
"""
Always True
:return: True
:rtype: bool
"""
return True
def create(self, overwrite=True):
"""
Setup a loop device of the blocksize given in the constructor
The file to loop is created with the size specified in the
constructor unless an existing one should not be overwritten
:param bool overwrite: overwrite existing file to loop
"""
if overwrite:
qemu_img_size = format(self.filesize_mbytes) + 'M'
Command.run(
['qemu-img', 'create', self.filename, qemu_img_size]
)
loop_options = []
if self.blocksize_bytes and self.blocksize_bytes != 512:
if CommandCapabilities.has_option_in_help(
'losetup', '--sector-size', raise_on_error=False
):
loop_options.append('--sector-size')
else:
loop_options.append('--logical-blocksize')
loop_options.append(format(self.blocksize_bytes))
loop_call = Command.run(
['losetup'] + loop_options + ['-f', '--show', self.filename]
)
self.node_name = loop_call.output.rstrip('\n')
def __del__(self):
if self.node_name:
log.info('Cleaning up %s instance', type(self).__name__)
try:
Command.run(['losetup', '-d', self.node_name])
except Exception:
log.warning(
'loop device %s still busy', self.node_name
)