diskimage-builder/diskimage_builder/block_device/level1/partitioning.py

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# Copyright 2016 Andreas Florath (andreas@florath.net)
#
# 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 logging
import os
from diskimage_builder.block_device.exception import \
BlockDeviceSetupException
from diskimage_builder.block_device.level1.mbr import MBR
from diskimage_builder.block_device.level1.partition import PartitionNode
from diskimage_builder.block_device.plugin import PluginBase
from diskimage_builder.block_device.utils import exec_sudo
from diskimage_builder.block_device.utils import parse_abs_size_spec
from diskimage_builder.block_device.utils import parse_rel_size_spec
logger = logging.getLogger(__name__)
class Partitioning(PluginBase):
def __init__(self, config, default_config, state):
logger.debug("Creating Partitioning object; config [%s]", config)
super(Partitioning, self).__init__()
# Unlike other PluginBase we are somewhat persistent, as the
# partition nodes call back to us (see create() below). We
# need to keep this reference.
self.state = state
# Because using multiple partitions of one base is done
# within one object, there is the need to store a flag if the
# creation of the partitions was already done.
self.number_of_partitions = 0
# Parameter check
if 'base' not in config:
raise BlockDeviceSetupException("Partitioning config needs 'base'")
self.base = config['base']
if 'partitions' not in config:
raise BlockDeviceSetupException(
"Partitioning config needs 'partitions'")
if 'label' not in config:
raise BlockDeviceSetupException(
"Partitioning config needs 'label'")
self.label = config['label']
if self.label not in ("mbr", "gpt"):
raise BlockDeviceSetupException("Label must be 'mbr' or 'gpt'")
# It is VERY important to get the alignment correct. If this
# is not correct, the disk performance might be very poor.
# Example: In some tests a 'off by one' leads to a write
# performance of 30% compared to a correctly aligned
# partition.
# The problem for DIB is, that it cannot assume that the host
# system uses the same IO sizes as the target system,
# therefore here a fixed approach (as used in all modern
# systems with large disks) is used. The partitions are
# aligned to 1MiB (which are about 2048 times 512 bytes
# blocks)
self.align = 1024 * 1024 # 1MiB as default
if 'align' in config:
self.align = parse_abs_size_spec(config['align'])
self.partitions = []
prev_partition = None
for part_cfg in config['partitions']:
np = PartitionNode(part_cfg, state, self, prev_partition)
self.partitions.append(np)
prev_partition = np
def get_nodes(self):
# return the list of partitions
return self.partitions
def _size_of_block_dev(self, dev):
with open(dev, "r") as fd:
fd.seek(0, 2)
return fd.tell()
def _create_mbr(self):
"""Create partitions with MBR"""
with MBR(self.image_path, self.disk_size, self.align) as part_impl:
for part_cfg in self.partitions:
part_name = part_cfg.get_name()
part_bootflag = PartitionNode.flag_boot \
in part_cfg.get_flags()
part_primary = PartitionNode.flag_primary \
in part_cfg.get_flags()
part_size = part_cfg.get_size()
part_free = part_impl.free()
part_type = part_cfg.get_type()
logger.debug("Not partitioned space [%d]", part_free)
part_size = parse_rel_size_spec(part_size,
part_free)[1]
part_no \
= part_impl.add_partition(part_primary, part_bootflag,
part_size, part_type)
logger.debug("Create partition [%s] [%d]",
part_name, part_no)
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
# We're going to mount all partitions with kpartx
# below once we're done. So the device this partition
# will be seen at becomes "/dev/mapper/loop0pX"
assert self.device_path[:5] == "/dev/"
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
partition_device_name = "/dev/mapper/%sp%d" % \
(self.device_path[5:], part_no)
self.state['blockdev'][part_name] \
= {'device': partition_device_name}
def _create_gpt(self):
"""Create partitions with GPT"""
cmd = ['sgdisk', self.image_path]
# This padding gives us a little room for rounding so we don't
# go over the end of the disk
disk_free = self.disk_size - (2048 * 1024)
pnum = 1
for p in self.partitions:
args = {}
args['pnum'] = pnum
args['name'] = '%s' % p.get_name()
args['type'] = '%s' % p.get_type()
# convert from a relative/string size to bytes
size = parse_rel_size_spec(p.get_size(), disk_free)[1]
# We keep track in bytes, but specify things to sgdisk in
# megabytes so it can align on sensible boundaries. And
# create partitions right after previous so no need to
# calculate start/end - just size.
assert size <= disk_free
args['size'] = size // (1024 * 1024)
new_cmd = ("-n", "{pnum}:0:+{size}M".format(**args),
"-t", "{pnum}:{type}".format(**args),
# Careful with this one, as {name} could have spaces
"-c", "{pnum}:{name}".format(**args))
cmd.extend(new_cmd)
# Fill the state; we mount all partitions with kpartx
# below once we're done. So the device this partition
# will be seen at becomes "/dev/mapper/loop0pX"
assert self.device_path[:5] == "/dev/"
device_name = "/dev/mapper/%sp%d" % (self.device_path[5:], pnum)
self.state['blockdev'][p.get_name()] \
= {'device': device_name}
disk_free = disk_free - size
pnum = pnum + 1
logger.debug("Partition %s added, %s remaining in disk",
pnum, disk_free)
logger.debug("cmd: %s", ' '.join(cmd))
exec_sudo(cmd)
# not this is NOT a node and this is not called directly! The
# create() calls in the partition nodes this plugin has
# created are calling back into this.
def create(self):
# This is a bit of a hack. Each of the partitions is actually
# in the graph, so for every partition we get a create() call
# as the walk happens. But we only need to create the
# partition table once...
self.number_of_partitions += 1
if self.number_of_partitions > 1:
logger.info("Not creating the partitions a second time.")
return
# the raw file on disk
self.image_path = self.state['blockdev'][self.base]['image']
# the /dev/loopX device of the parent
self.device_path = self.state['blockdev'][self.base]['device']
# underlying size
self.disk_size = self._size_of_block_dev(self.image_path)
logger.info("Creating partition on [%s] [%s]",
self.base, self.image_path)
assert self.label in ('mbr', 'gpt')
if self.label == 'mbr':
self._create_mbr()
elif self.label == 'gpt':
self._create_gpt()
# "saftey sync" to make sure the partitions are written
exec_sudo(["sync"])
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
# now all the partitions are created, get device-mapper to
# mount them
if not os.path.exists("/.dockerenv"):
exec_sudo(["kpartx", "-avs", self.device_path])
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
else:
# If running inside Docker, make our nodes manually,
# because udev will not be working. kpartx cannot run in
# sync mode in docker.
exec_sudo(["kpartx", "-av", self.device_path])
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
exec_sudo(["dmsetup", "--noudevsync", "mknodes"])
return
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
def umount(self):
# Remove the partition mappings made for the parent
# block-device by create() above. This is called from the
# child PartitionNode umount. Thus every
# partition calls it, but we only want to do it once when
# we know this is the very last partition
self.number_of_partitions -= 1
if self.number_of_partitions == 0:
Pass all blockdevices to bootloader Currently we only export "image-block-device" which is the loopback device (/dev/loopX) for the underlying image. This is the device we install grub to (from inside the chroot ...) This is ok for x86, but is insufficient for some platforms like PPC which have a separate boot partition. They do not want to install to the loop device, but do things like dd special ELF files into special boot partitions. The first problem seems to be that in level1/partitioning.py we have a whole bunch of different paths that either call partprobe on the loop device, or kpartx. We have _all_part_devices_exist() that gates the kpartx for unknown reasons. We have detach_loopback() that does not seem to remove losetup created devices. I don't think this does cleanup if it uses kpartx correctly. It is extremley unclear what's going to be mapped where. This moves to us *only* using kpartx to map the partitions of the loop device. We will *not* call partprobe and create the /dev/loopXpN devices and will only have the devicemapper nodes kpartx creates. This seems to be best. Cleanup happens inside partitioning.py. practice. Deeper thinking about this, and more cleanup of the variables will be welcome. This adds "image-block-devices" (note the extra "s") which exports all the block devices with name and path. This is in a string format that can be eval'd to an array (you can't export arrays). This is then used in a follow-on (I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right partition on PPC. Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-06 02:09:24 +00:00
exec_sudo(["kpartx", "-d",
self.state['blockdev'][self.base]['device']])
def cleanup(self):
pass