#
# loop.py
# loop device functions
#
# Copyright (C) 2010 Red Hat, Inc. All rights reserved.
#
# 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, see .
#
# Author(s): David Lehman
#
import os
from .. import util
from ..errors import *
import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)
import logging
log = logging.getLogger("storage")
def losetup(args, capture=False):
if capture:
exec_func = util.capture_output
else:
exec_func = util.run_program
try:
# ask losetup what this loop device's backing device is
ret = exec_func(["losetup"] + args)
except OSError as e:
raise LoopError(e.strerror)
return ret
def get_backing_file(name):
path = ""
sys_path = "/sys/class/block/%s/loop/backing_file" % name
if os.access(sys_path, os.R_OK):
path = open(sys_path).read().strip()
return path
def get_loop_name(path):
args = ["-j", path]
buf = losetup(args, capture=True)
if len(buf.splitlines()) > 1:
# there should never be more than one loop device listed
raise LoopError("multiple loops associated with %s" % path)
name = os.path.basename(buf.split(":")[0])
return name
def loop_setup(path):
args = ["-f", path]
msg = None
try:
msg = losetup(args)
except LoopError as e:
msg = str(e)
if msg:
raise LoopError("failed to set up loop for %s: %s" % (path, msg))
def loop_teardown(path):
args = ["-d", path]
msg = None
try:
msg = losetup(args)
except LoopError as e:
msg = str(e)
if msg:
raise DeviceError("failed to tear down loop %s: %s" % (path, msg))