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2f081e91c8
So far the default iteration order of python dicts has mostly matched the order that we want the partitions on disk but this is not always the case. I caught the BIOS-BOOT partition being ordered on disk after the USR-A partition. Nothing bad came of this but consistancy is good.
1019 lines
33 KiB
Python
Executable File
1019 lines
33 KiB
Python
Executable File
#!/usr/bin/python
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# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
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# Use of this source code is governed by a BSD-style license that can be
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# found in the LICENSE file.
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import argparse
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import contextlib
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import json
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import os
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import re
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import subprocess
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import sys
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import tempfile
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import uuid
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# First sector we can use.
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GPT_RESERVED_SECTORS = 34
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# Default MBR boot code for GPT
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DEFAULT_MBR_BOOT_CODE = '/usr/share/syslinux/gptmbr.bin'
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class ConfigNotFound(Exception):
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pass
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class PartitionNotFound(Exception):
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pass
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class InvalidLayout(Exception):
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pass
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class InvalidAdjustment(Exception):
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pass
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class InvalidBootCode(Exception):
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pass
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def LoadPartitionConfig(options):
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"""Loads a partition tables configuration file into a Python object.
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Args:
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options: Flags passed to the script
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Returns:
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Object containing disk layout configuration
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"""
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valid_keys = set(('_comment', 'metadata', 'layouts'))
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valid_layout_keys = set((
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'_comment', 'type', 'num', 'label', 'blocks', 'block_size', 'fs_blocks',
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'fs_block_size', 'fs_type', 'features', 'uuid', 'part_alignment', 'mount',
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'binds', 'fs_subvolume'))
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integer_layout_keys = set((
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'blocks', 'block_size', 'fs_blocks', 'fs_block_size', 'part_alignment'))
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required_layout_keys = set(('type', 'num', 'label', 'blocks'))
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filename = options.disk_layout_file
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if not os.path.exists(filename):
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raise ConfigNotFound('Partition config %s was not found!' % filename)
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with open(filename) as f:
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config = json.load(f)
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unknown_keys = set(config.keys()) - valid_keys
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if unknown_keys:
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raise InvalidLayout('Unknown items: %s' % ' '.join(unknown_keys))
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try:
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metadata = config['metadata']
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base = config['layouts']['base']
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for key in ('part_alignment', 'disk_alignment',
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'block_size', 'fs_block_size'):
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metadata[key] = int(metadata[key])
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except KeyError as e:
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raise InvalidLayout('Metadata is missing required entries: %s' % e)
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def VerifyLayout(layout_name, layout, base=None):
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for part_num, part in layout.iteritems():
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part['num'] = int(part_num)
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part_keys = set(part.iterkeys())
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unknown_keys = part_keys - valid_layout_keys
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if unknown_keys:
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raise InvalidLayout('Unknown items in partition %s %s: %r' %
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(layout_name, part_num, ' '.join(unknown_keys)))
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for int_key in integer_layout_keys.intersection(part_keys):
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part[int_key] = int(part[int_key])
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if base:
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part_base = base.get(part_num, {})
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part_keys.update(part_base.iterkeys())
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if part.get('type', None) == 'blank':
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continue
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missing_keys = required_layout_keys - part_keys
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if missing_keys:
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raise InvalidLayout('Missing items in partition %s %s: %s' %
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(layout_name, part_num, ' '.join(missing_keys)))
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if 'uuid' in part:
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try:
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# double check the string formatting
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part['uuid'] = str(uuid.UUID(part['uuid']))
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except ValueError as e:
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raise InvalidLayout('Invalid uuid %r: %s' % (part['uuid'], e))
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if 'fs_type' in part:
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if part['fs_type'] not in ('btrfs', 'ext2', 'ext4', 'vfat'):
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raise InvalidLayout('Invalid fs_type: %r' % part['fs_type'])
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if 'fs_subvolume' in part:
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if part.get('fs_type', None) != 'btrfs':
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raise InvalidLayout('Invalid fs: only btrfs supports subvolumes')
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def Align(count, alignment):
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offset = count % alignment
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if offset:
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count += alignment - offset
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return count
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def FillExtraValues(layout_name, layout, base=None):
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# Reserved size for first GPT
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disk_block_count = GPT_RESERVED_SECTORS
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# Fill in default values from base,
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# dict doesn't have a update()+setdefault() method so this looks tedious
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if base:
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for part_num, base_part in base.iteritems():
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part = layout.setdefault(part_num, {})
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for base_key, base_value in base_part.iteritems():
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part.setdefault(base_key, base_value)
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for part_num, part in sorted(layout.iteritems(), key=lambda t: int(t[0])):
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if part['type'] == 'blank':
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continue
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part.setdefault('part_alignment', metadata['part_alignment'])
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part['bytes'] = part['blocks'] * metadata['block_size']
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part.setdefault('fs_block_size', metadata['fs_block_size'])
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part.setdefault('fs_blocks', part['bytes'] // part['fs_block_size'])
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part['fs_bytes'] = part['fs_blocks'] * part['fs_block_size']
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if part['fs_bytes'] > part['bytes']:
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raise InvalidLayout(
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'Filesystem may not be larger than partition: %s %s: %d > %d' %
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(layout_name, part_num, part['fs_bytes'], part['bytes']))
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disk_block_count = Align(disk_block_count, part['part_alignment'])
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part['first_block'] = disk_block_count
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part['first_byte'] = disk_block_count * metadata['block_size']
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disk_block_count += part['blocks']
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part.setdefault('uuid', str(uuid.uuid4()))
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# Reserved size for second GPT plus align disk image size
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disk_block_count += GPT_RESERVED_SECTORS
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disk_block_count = Align(disk_block_count, metadata['disk_alignment'])
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# If this is the requested layout stash the disk size into the global
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# metadata. Kinda odd but the best place I've got with this data structure.
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if layout_name == options.disk_layout:
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metadata['blocks'] = disk_block_count
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metadata['bytes'] = disk_block_count * metadata['block_size']
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# Verify 'base' before other layouts because it is inherited by the others
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# Fill in extra/default values in base last so they aren't inherited
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VerifyLayout('base', base)
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for layout_name, layout in config['layouts'].iteritems():
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if layout_name == 'base':
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continue
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VerifyLayout(layout_name, layout, base)
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FillExtraValues(layout_name, layout, base)
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FillExtraValues('base', base)
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return config, config['layouts'][options.disk_layout]
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def GetPartitionTableFromConfig(options):
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"""Loads a partition table and returns a given partition table type
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Args:
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options: Flags passed to the script
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Returns:
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A list defining all known partitions.
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"""
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config, partitions = LoadPartitionConfig(options)
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return partitions
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def GetPartitionTableFromImage(options, config, partitions):
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"""Loads very basic partition table info from an existing image.
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Currently only includes blocks and first_block values.
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Args:
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options: Flags passed to the script
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Returns:
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A list defining all existing partitions.
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"""
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block_size = config['metadata']['block_size']
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cgpt_show = subprocess.check_output(
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['cgpt', 'show', '-q', options.disk_image])
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for line in cgpt_show.split('\n'):
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if not line.strip():
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continue
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fields = line.split(None, 3)
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if len(fields) != 4 or not all(f.isdigit() for f in fields[:3]):
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raise Exception('Invalid output from cgpt show -q: %r' % line)
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part = partitions.setdefault(fields[2], {})
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part['image_first_block'] = int(fields[0])
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part['image_first_byte'] = int(fields[0]) * block_size
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part['image_blocks'] = int(fields[1])
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part['image_bytes'] = int(fields[1]) * block_size
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# Pre-compute whether the image and config are compatible.
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# The image is compatible with the config if each partition:
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# - starts at the same position
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# - is the same size or larger in th layout config
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part['image_exists'] = True
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if part.get('type', 'blank') == 'blank':
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part['image_compat'] = False
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elif part['first_block'] == part['image_first_block']:
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part['image_compat'] = part['blocks'] >= part['image_blocks']
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else:
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part['image_compat'] = False
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for part in partitions.itervalues():
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if part.get('type', 'blank') == 'blank':
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continue
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if not part.get('image_exists', False):
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continue
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if not part.get('fs_type', None):
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continue
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with PartitionLoop(options, part) as loop_dev:
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try:
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part['image_fs_type'] = subprocess.check_output(
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['sudo', 'blkid', '-o', 'value', '-s', 'TYPE', loop_dev]).strip()
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except subprocess.CalledProcessError:
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part['image_fs_type'] = None
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# Set compat flags for any partition not in the image
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for part in partitions.itervalues():
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part.setdefault('image_exists', False)
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if part.get('type', 'blank') == 'blank':
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part.setdefault('image_compat', True)
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else:
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part.setdefault('image_compat', False)
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def WritePartitionTable(options, config=None, partitions=None):
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"""Writes the given partition table to a disk image or device.
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Args:
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options: Flags passed to the script
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config: Complete layout configuration file object
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partitions: Selected layout configuration object
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"""
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def Cgpt(*args):
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subprocess.check_call(['cgpt'] + [str(a) for a in args])
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if not (config and partitions):
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config, partitions = LoadPartitionConfig(options)
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if options.create:
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Cgpt('create', '-c', '-s', config['metadata']['blocks'], options.disk_image)
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else:
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# If we are not creating a fresh image all partitions must be compatible.
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GetPartitionTableFromImage(options, config, partitions)
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if not all(p['image_compat'] for p in partitions.itervalues()):
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raise InvalidLayout("New disk layout is incompatible existing image")
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# Extend the disk image size as needed
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with open(options.disk_image, 'r+') as image_fd:
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image_fd.truncate(config['metadata']['bytes'])
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Cgpt('repair', options.disk_image)
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syslinux = False
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hybrid = None
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for partition in partitions.itervalues():
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if partition['type'] != 'blank':
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Cgpt('add', '-i', partition['num'],
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'-b', partition['first_block'],
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'-s', partition['blocks'],
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'-t', partition['type'],
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'-l', partition['label'],
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'-u', partition['uuid'],
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options.disk_image)
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features = partition.get('features', [])
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if not hybrid and ('syslinux' in features or 'hybrid' in features):
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hybrid = partition['num']
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if 'syslinux' in features:
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syslinux = True
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if hybrid:
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# Enable legacy boot flag and generate a hybrid MBR partition table
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Cgpt('add', '-i', hybrid, '-B1', options.disk_image)
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if syslinux and options.mbr_boot_code:
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try:
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with open(options.mbr_boot_code, 'r') as mbr_fd:
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mbr_code = mbr_fd.read()
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except IOError, ex:
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raise InvalidBootCode("Failed to read %s: %s",
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options.mbr_boot_code, ex)
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# The boot code must fit in the first 440 bytes of disk
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if len(mbr_code) != 440:
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raise InvalidBootCode("Invalid %s size %s, must be 440 bytes",
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options.mbr_boot_code, len(mbr_code))
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with open(options.disk_image, 'r+') as image_fd:
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image_fd.write(mbr_code)
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Cgpt('show', options.disk_image)
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def Sudo(cmd, stdout_null=False):
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"""Little wrapper around sudo with support for redirecting to /dev/null
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Some tools like tune2fs don't have a quiet mode which just adds
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useless noise to our build output, drowning out what may be more
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interesting news.
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Args:
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cmd: a command and arguments to run.
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stdout_null: bool to enable redirecting stdout to /dev/null.
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"""
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null = None
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if stdout_null:
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null = open('/dev/null', 'w')
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try:
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subprocess.check_call(['sudo'] + [str(c) for c in cmd], stdout=null)
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finally:
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if null:
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null.close()
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def BtrfsSubvolId(path):
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"""Get the subvolume id from a given path."""
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out = subprocess.check_output(
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['sudo', 'btrfs', 'subvolume', 'show', path])
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m = re.search(r'^\s*Object ID:\s*(\d+)$', out, re.MULTILINE)
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if not m:
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raise Exception('Failed to parse btrfs output: %r', out)
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return int(m.group(1))
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def FormatBtrfs(part, device):
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"""Format a btrfs filesystem.
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Args:
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part: dict defining the partition
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device: name of the block device to format
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"""
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Sudo(['mkfs.btrfs', '--byte-count', part['fs_bytes'],
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'--label', part['label'],
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device])
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if part.get('fs_subvolume', None):
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btrfs_mount = tempfile.mkdtemp()
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subvol_path = '%s/%s' % (btrfs_mount, part['fs_subvolume'])
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Sudo(['mount', '-t', 'btrfs', device, btrfs_mount])
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try:
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Sudo(['btrfs', 'subvolume', 'create', subvol_path])
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subvol_id = BtrfsSubvolId(subvol_path)
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Sudo(['btrfs', 'subvolume', 'set-default', subvol_id, btrfs_mount])
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finally:
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Sudo(['umount', btrfs_mount])
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os.rmdir(btrfs_mount)
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def FormatExt(part, device):
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"""Format an ext2 or ext4 filesystem.
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Args:
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part: dict defining the partition
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device: name of the block device to format
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"""
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Sudo(['mke2fs', '-q',
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'-t', part['fs_type'],
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'-b', part['fs_block_size'],
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device,
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part['fs_blocks']])
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tune_cmd = ['tune2fs', '-L', part['label'], '-e', 'remount-ro']
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if part['type'] == 'coreos-usr':
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tune_cmd += ['-U', 'clear',
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'-T', '20091119110000',
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'-c', '0', '-i', '0', # Disable auto fsck
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'-m', '0', '-r', '0'] # Disable reserve blocks
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Sudo(tune_cmd + [device], stdout_null=True)
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def FormatFat(part, device):
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"""Format a FAT filesystem.
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Args:
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part: dict defining the partition
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device: name of the block device to format
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"""
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# The block-count argument to mkfs.vfat is in units of 1k
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vfat_block_size = 1024
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vfat_blocks = part['bytes'] // vfat_block_size
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Sudo(['mkfs.vfat', '-n', part['label'],
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device,
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vfat_blocks],
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stdout_null=True)
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if 'syslinux' in part.get('features', []):
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# Install using extlinux so we can operate on the mounted filesystem and
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# avoid possible issues with mtools. Also hpa told me to. :)
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# cgpt uses 255 heads and 63 sectors when generating the hybrid MBR which
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# doesn't actually have to match what we use here but doesn't hurt either.
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vfat_mount = tempfile.mkdtemp()
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syslinux_dir = os.path.join(vfat_mount, 'syslinux')
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Sudo(['mount', '-t', 'vfat', device, vfat_mount])
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try:
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Sudo(['mkdir', syslinux_dir])
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Sudo(['extlinux', '--heads=255', '--sectors=63',
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'--install', syslinux_dir])
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finally:
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Sudo(['umount', vfat_mount])
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os.rmdir(vfat_mount)
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print "Installed SYSLINUX to %s" % part['label']
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@contextlib.contextmanager
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def PartitionLoop(options, partition):
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"""Allocate (and automatically free) loop devices for a partition."""
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loop_dev = subprocess.check_output(['sudo', 'losetup',
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'--offset', str(partition['first_byte']),
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'--sizelimit', str(partition['bytes']),
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'--find', '--show', options.disk_image])
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loop_dev = loop_dev.strip()
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try:
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yield loop_dev
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finally:
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Sudo(['losetup', '--detach', loop_dev])
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def FormatPartition(options, part):
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print "Formatting partition %s (%s) as %s" % (
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part['num'], part['label'], part['fs_type'])
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with PartitionLoop(options, part) as loop_dev:
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if part['fs_type'] in ('ext2', 'ext4'):
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FormatExt(part, loop_dev)
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elif part['fs_type'] == 'btrfs':
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FormatBtrfs(part, loop_dev)
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elif part['fs_type'] == 'vfat':
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FormatFat(part, loop_dev)
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else:
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raise Exception("Unhandled fs type %s" % part['fs_type'])
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def Format(options):
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"""Writes the given partition table and initialize fresh filesystems.
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Args:
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options: Flags passed to the script
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"""
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# Note on using sudo: We don't really need to do this stuff as root
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# but mke2fs and friends doesn't have an option to make filesystems at
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# arbitrary offsets but using loop devices makes that possible.
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config, partitions = LoadPartitionConfig(options)
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WritePartitionTable(options, config, partitions)
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for part in partitions.itervalues():
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if part['type'] == 'blank' or 'fs_type' not in part:
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continue
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FormatPartition(options, part)
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def ResizeExt(part, device):
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"""Resize ext[234] filesystems.
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Args:
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part: dict defining the partition
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device: name of the block device
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"""
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Sudo(['e2fsck', '-p', '-f', device], stdout_null=True)
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Sudo(['resize2fs', device, str(part['fs_blocks'])])
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def ResizeBtrfs(part, device):
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"""Resize btrfs filesystems.
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Args:
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part: dict defining the partition
|
|
device: name of the block device
|
|
"""
|
|
btrfs_mount = tempfile.mkdtemp()
|
|
Sudo(['mount', '-t', 'btrfs', device, btrfs_mount])
|
|
try:
|
|
Sudo(['btrfs', 'filesystem', 'resize', part['fs_bytes'], btrfs_mount])
|
|
finally:
|
|
Sudo(['umount', btrfs_mount])
|
|
os.rmdir(btrfs_mount)
|
|
|
|
|
|
def Update(options):
|
|
"""Writes the given partition table, resize filesystems, and
|
|
format free partitions.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
WritePartitionTable(options, config, partitions)
|
|
|
|
for part in partitions.itervalues():
|
|
if not part.get('fs_type', None):
|
|
continue
|
|
elif not part['image_fs_type']:
|
|
FormatPartition(options, part)
|
|
|
|
for part in partitions.itervalues():
|
|
resize_func = None
|
|
if not part.get('fs_type', None):
|
|
continue
|
|
elif part['bytes'] == part['image_bytes']:
|
|
continue
|
|
elif part['fs_type'] in ('ext2', 'ext4') and IsE2fsReadWrite(options, part):
|
|
resize_func = ResizeExt
|
|
elif part.get('fs_type', None) == 'btrfs':
|
|
resize_func = ResizeBtrfs
|
|
else:
|
|
continue
|
|
|
|
print "Resizing partition %s (%s) to %s bytes" % (
|
|
part['num'], part['label'], part['fs_bytes'])
|
|
|
|
with PartitionLoop(options, part) as loop_dev:
|
|
resize_func(part, loop_dev)
|
|
|
|
|
|
def Mount(options):
|
|
"""Mount the given disk image.
|
|
|
|
The existing partition table is used to determine what exists but the
|
|
disk layout config is used to look up mount points and binds.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
GetPartitionTableFromImage(options, config, partitions)
|
|
mounts = {}
|
|
|
|
for part_num, part in partitions.iteritems():
|
|
path = part.get('mount', None)
|
|
if not path or not path.startswith('/'):
|
|
continue
|
|
if not part.get('image_exists', False):
|
|
continue
|
|
|
|
mounts[path] = part
|
|
|
|
if '/' not in mounts:
|
|
raise InvalidLayout('No partition defined to mount on /')
|
|
|
|
def DoMount(mount):
|
|
full_path = os.path.realpath(options.mount_dir + mount['mount'])
|
|
mount_opts = ['loop',
|
|
'offset=%d' % mount['image_first_byte'],
|
|
'sizelimit=%d' % mount['image_bytes']]
|
|
if options.read_only:
|
|
mount_opts.append('ro')
|
|
elif (mount.get('fs_type', None) in ('ext2', 'ext4') and
|
|
not IsE2fsReadWrite(options, mount)):
|
|
mount_opts.append('ro')
|
|
|
|
if mount.get('fs_subvolume', None):
|
|
mount_opts.append('subvol=%s' % mount['fs_subvolume'])
|
|
|
|
Sudo(['mkdir', '-p', full_path])
|
|
Sudo(['mount', '-t', mount.get('fs_type', 'auto'),
|
|
'-o', ','.join(mount_opts),
|
|
options.disk_image, full_path])
|
|
|
|
for src, dst in mount.get('binds', {}).iteritems():
|
|
# src may be relative or absolute, os.path.join handles this.
|
|
full_src = os.path.realpath(
|
|
options.mount_dir + os.path.join(mount['mount'], src))
|
|
full_dst = os.path.realpath(options.mount_dir + dst)
|
|
Sudo(['mkdir', '-p', full_src, full_dst])
|
|
Sudo(['mount', '--bind', full_src, full_dst])
|
|
|
|
for mount in sorted(mounts, key=len):
|
|
DoMount(mounts[mount])
|
|
|
|
def Umount(options):
|
|
"""Unmount the given path.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
Sudo(['umount', '--recursive', '--detach-loop', options.mount_dir])
|
|
|
|
|
|
def Tune2fsReadWrite(options, partition):
|
|
"""Enable/Disable read-only hack.
|
|
|
|
From common.sh:
|
|
This helper clobbers the ro compat value in our root filesystem.
|
|
|
|
When the system is built with --enable_rootfs_verification, bit-precise
|
|
integrity checking is performed. That precision poses a usability issue on
|
|
systems that automount partitions with recognizable filesystems, such as
|
|
ext2/3/4. When the filesystem is mounted 'rw', ext2 metadata will be
|
|
automatically updated even if no other writes are performed to the
|
|
filesystem. In addition, ext2+ does not support a "read-only" flag for a
|
|
given filesystem. That said, forward and backward compatibility of
|
|
filesystem features are supported by tracking if a new feature breaks r/w or
|
|
just write compatibility. We abuse the read-only compatibility flag[1] in
|
|
the filesystem header by setting the high order byte (le) to FF. This tells
|
|
the kernel that features R24-R31 are all enabled. Since those features are
|
|
undefined on all ext-based filesystem, all standard kernels will refuse to
|
|
mount the filesystem as read-write -- only read-only[2].
|
|
|
|
[1] 32-bit flag we are modifying:
|
|
http://git.chromium.org/cgi-bin/gitweb.cgi?p=kernel.git;a=blob;f=include/linux/ext2_fs.h#l417
|
|
[2] Mount behavior is enforced here:
|
|
http://git.chromium.org/cgi-bin/gitweb.cgi?p=kernel.git;a=blob;f=fs/ext2/super.c#l857
|
|
|
|
N.B., if the high order feature bits are used in the future, we will need to
|
|
revisit this technique.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
partition: Config for partition to manipulate
|
|
"""
|
|
|
|
if options.disable2fs_rw:
|
|
print "Disabling read-write mounting of partition %s (%s)" % (
|
|
partition['num'], partition['label'])
|
|
else:
|
|
print "Enabling read-write mounting of partition %s (%s)" % (
|
|
partition['num'], partition['label'])
|
|
|
|
# offset of ro_compat, highest order byte (le 32 bit field)
|
|
flag_offset = 0x464 + 3
|
|
flag_value = 0xff if options.disable2fs_rw else 0x00
|
|
with open(options.disk_image, 'r+') as image:
|
|
image.seek(partition['first_byte'] + flag_offset)
|
|
image.write(chr(flag_value))
|
|
|
|
|
|
def IsE2fsReadWrite(options, partition):
|
|
"""Returns True if FS is read-write, False if hack is active.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
partition: Config for partition to query
|
|
"""
|
|
|
|
# offset of ro_compat, highest order byte (le 32 bit field)
|
|
flag_offset = 0x464 + 3
|
|
with open(options.disk_image, 'r') as image:
|
|
image.seek(partition['first_byte'] + flag_offset)
|
|
flag_value = image.read(1)
|
|
|
|
return ord(flag_value) == 0
|
|
|
|
|
|
def Tune(options):
|
|
"""Tweak some filesystem options.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
GetPartitionTableFromImage(options, config, partitions)
|
|
part = GetPartition(partitions, options.partition)
|
|
|
|
if not part['image_compat']:
|
|
raise InvalidLayout("Disk layout is incompatible with existing image")
|
|
|
|
if options.disable2fs_rw is not None:
|
|
if part.get('fs_type', None) not in ('ext2', 'ext4'):
|
|
raise Exception("Partition %s is not a ext2 or ext4" % options.partition)
|
|
Tune2fsReadWrite(options, part)
|
|
else:
|
|
raise Exception("No options specified!")
|
|
|
|
|
|
def Extract(options):
|
|
"""Write a single partition out to its own image file.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
GetPartitionTableFromImage(options, config, partitions)
|
|
part = GetPartition(partitions, options.partition)
|
|
|
|
if not part['image_compat']:
|
|
raise InvalidLayout("Disk layout is incompatible with existing image")
|
|
|
|
subprocess.check_call(['dd',
|
|
'bs=10MB',
|
|
'iflag=count_bytes,skip_bytes',
|
|
'conv=sparse',
|
|
'status=none',
|
|
'if=%s' % options.disk_image,
|
|
'of=%s' % options.output,
|
|
'skip=%s' % part['image_first_byte'],
|
|
'count=%s' % part['image_bytes']])
|
|
|
|
|
|
def GetPartitionByNumber(partitions, num):
|
|
"""Given a partition table and number returns the partition object.
|
|
|
|
Args:
|
|
partitions: List of partitions to search in
|
|
num: Number of partition to find
|
|
Returns:
|
|
An object for the selected partition
|
|
"""
|
|
|
|
partition = partitions.get(str(num), None)
|
|
if not partition or partition['type'] == 'blank':
|
|
raise PartitionNotFound('Partition not found')
|
|
|
|
return partition
|
|
|
|
|
|
def GetPartitionByLabel(partitions, label):
|
|
"""Given a partition table and label returns the partition object.
|
|
|
|
Args:
|
|
partitions: List of partitions to search in
|
|
label: Label of partition to find
|
|
Returns:
|
|
An object for the selected partition
|
|
"""
|
|
for partition in partitions.itervalues():
|
|
if partition['type'] == 'blank':
|
|
continue
|
|
elif partition['label'] == label:
|
|
return partition
|
|
|
|
raise PartitionNotFound('Partition not found')
|
|
|
|
|
|
def GetPartition(partitions, part_id):
|
|
"""Given a partition table and label or num returns the partition object.
|
|
|
|
Args:
|
|
partitions: List of partitions to search in
|
|
part_id: Label or number of partition to find
|
|
Returns:
|
|
An object for the selected partition
|
|
"""
|
|
if str(part_id).isdigit():
|
|
return GetPartitionByNumber(partitions, part_id)
|
|
else:
|
|
return GetPartitionByLabel(partitions, part_id)
|
|
|
|
|
|
def GetBlockSize(options):
|
|
"""Returns the partition table block size.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Block size of all partitions in the layout
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
print config['metadata']['block_size']
|
|
|
|
|
|
def GetFilesystemBlockSize(options):
|
|
"""Returns the filesystem block size.
|
|
|
|
This is used for all partitions in the table that have filesystems.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Block size of all filesystems in the layout
|
|
"""
|
|
|
|
config, partitions = LoadPartitionConfig(options)
|
|
print config['metadata']['fs_block_size']
|
|
|
|
|
|
def GetPartitionSize(options):
|
|
"""Returns the partition size of a given partition for a given layout type.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Size of selected partition in bytes
|
|
"""
|
|
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
partition = GetPartitionByNumber(partitions, options.partition_num)
|
|
print partition['bytes']
|
|
|
|
|
|
def GetFilesystemSize(options):
|
|
"""Returns the filesystem size of a given partition for a given layout type.
|
|
|
|
If no filesystem size is specified, returns the partition size.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Size of selected partition filesystem in bytes
|
|
"""
|
|
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
partition = GetPartitionByNumber(partitions, options.partition_num)
|
|
print partition.get('fs_bytes', partition['bytes'])
|
|
|
|
|
|
def GetLabel(options):
|
|
"""Returns the label for a given partition.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Label of selected partition, or 'UNTITLED' if none specified
|
|
"""
|
|
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
partition = GetPartitionByNumber(partitions, options.partition_num)
|
|
print partition.get('label', 'UNTITLED')
|
|
|
|
|
|
def GetNum(options):
|
|
"""Returns the number for a given label.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
Number of selected partition, or '-1' if there is no number
|
|
"""
|
|
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
partition = GetPartitionByLabel(partitions, options.label)
|
|
print partition.get('num', '-1')
|
|
|
|
|
|
def GetUuid(options):
|
|
"""Returns the unique partition UUID for a given label.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
Prints:
|
|
String containing the requested UUID
|
|
"""
|
|
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
partition = GetPartitionByLabel(partitions, options.label)
|
|
print partition.get('uuid', '')
|
|
|
|
|
|
def DoDebugOutput(options):
|
|
"""Prints out a human readable disk layout in on-disk order.
|
|
|
|
This will round values larger than 1MB, it's exists to quickly
|
|
visually verify a layout looks correct.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
partitions = GetPartitionTableFromConfig(options)
|
|
|
|
for num, partition in sorted(partitions.iteritems()):
|
|
if partition['type'] != 'blank':
|
|
if partition['bytes'] < 1024 * 1024:
|
|
size = '%d bytes' % partition['bytes']
|
|
else:
|
|
size = '%d MB' % (partition['bytes'] / 1024 / 1024)
|
|
if 'fs_bytes' in partition:
|
|
if partition['fs_bytes'] < 1024 * 1024:
|
|
fs_size = '%d bytes' % partition['fs_bytes']
|
|
else:
|
|
fs_size = '%d MB' % (partition['fs_bytes'] / 1024 / 1024)
|
|
print '%s: %s - %s/%s' % (num, partition['label'], fs_size, size)
|
|
else:
|
|
print '%s: %s - %s' % (num, partition['label'], size)
|
|
else:
|
|
print '%s: blank' % num
|
|
|
|
|
|
def DoParseOnly(options):
|
|
"""Parses a layout file only, used before reading sizes to check for errors.
|
|
|
|
Args:
|
|
options: Flags passed to the script
|
|
"""
|
|
GetPartitionTableFromConfig(options)
|
|
|
|
|
|
def main(argv):
|
|
default_layout_file = os.environ.get('DISK_LAYOUT_FILE',
|
|
os.path.join(os.path.dirname(__file__), 'disk_layout.json'))
|
|
default_layout_type = os.environ.get('DISK_LAYOUT_TYPE', 'base')
|
|
|
|
parser = argparse.ArgumentParser(
|
|
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
|
|
parser.add_argument('--disk_layout_file', default=default_layout_file,
|
|
help='path to disk layout json file')
|
|
parser.add_argument('--disk_layout', default=default_layout_type,
|
|
help='disk layout type from the json file')
|
|
actions = parser.add_subparsers(title='actions')
|
|
|
|
a = actions.add_parser('write_gpt', help='write/update partition table')
|
|
a.add_argument('--create', action='store_true', default=True,
|
|
help='initialize new partition table')
|
|
a.add_argument('--update', action='store_false', dest='create',
|
|
help='update existing partition table')
|
|
a.add_argument('--mbr_boot_code', default=DEFAULT_MBR_BOOT_CODE,
|
|
help='path to mbr boot block, such as syslinux/gptmbr.bin')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.set_defaults(func=WritePartitionTable)
|
|
|
|
a = actions.add_parser('format', help='write gpt and filesystems to image')
|
|
a.add_argument('--mbr_boot_code', default=DEFAULT_MBR_BOOT_CODE,
|
|
help='path to mbr boot block, such as syslinux/gptmbr.bin')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.set_defaults(func=Format, create=True)
|
|
|
|
a = actions.add_parser('update',
|
|
help='write gpt, resize filesystems, and format free partitions')
|
|
a.add_argument('--mbr_boot_code', default=DEFAULT_MBR_BOOT_CODE,
|
|
help='path to mbr boot block, such as syslinux/gptmbr.bin')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.set_defaults(func=Update, create=False)
|
|
|
|
a = actions.add_parser('mount', help='mount filesystems in image')
|
|
a.add_argument('--read_only', '-r', action='store_true',
|
|
help='mount filesystems read-only')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.add_argument('mount_dir', help='path to root filesystem mount point')
|
|
a.set_defaults(func=Mount)
|
|
|
|
a = actions.add_parser('umount', help='unmount a image mount point')
|
|
a.add_argument('mount_dir', help='path to root filesystem mount point')
|
|
a.set_defaults(func=Umount)
|
|
|
|
a = actions.add_parser('tune', help='tweak filesystem options')
|
|
a.add_argument('--disable2fs_rw', action='store_true', default=None,
|
|
help='disable mounting ext2 filesystems read-write')
|
|
a.add_argument('--enable2fs_rw', action='store_false', dest='disable2fs_rw',
|
|
help='re-enable mounting ext2 filesystems read-write')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.add_argument('partition', help='number or label of partition to edit')
|
|
a.set_defaults(func=Tune)
|
|
|
|
a = actions.add_parser('extract', help='extract a single partition')
|
|
a.add_argument('disk_image', help='path to disk image file')
|
|
a.add_argument('partition', help='number or label of partition to edit')
|
|
a.add_argument('output', help='path to write the partition image to')
|
|
a.set_defaults(func=Extract)
|
|
|
|
a = actions.add_parser('readblocksize', help='get device block size')
|
|
a.set_defaults(func=GetBlockSize)
|
|
|
|
a = actions.add_parser('readfsblocksize', help='get filesystem block size')
|
|
a.set_defaults(func=GetFilesystemBlockSize)
|
|
|
|
a = actions.add_parser('readpartsize', help='get partition size')
|
|
a.add_argument('partition_num', type=int, help='partition number')
|
|
a.set_defaults(func=GetPartitionSize)
|
|
|
|
a = actions.add_parser('readfssize', help='get filesystem size')
|
|
a.add_argument('partition_num', type=int, help='partition number')
|
|
a.set_defaults(func=GetFilesystemSize)
|
|
|
|
a = actions.add_parser('readlabel', help='get partition label')
|
|
a.add_argument('partition_num', type=int, help='partition number')
|
|
a.set_defaults(func=GetLabel)
|
|
|
|
a = actions.add_parser('readnum', help='get partition number')
|
|
a.add_argument('label', help='partition label')
|
|
a.set_defaults(func=GetNum)
|
|
|
|
a = actions.add_parser('readuuid', help='get partition uuid')
|
|
a.add_argument('label', help='partition label')
|
|
a.set_defaults(func=GetUuid)
|
|
|
|
a = actions.add_parser('debug', help='dump debug output')
|
|
a.set_defaults(func=DoDebugOutput)
|
|
|
|
a = actions.add_parser('parseonly', help='validate config')
|
|
a.set_defaults(func=DoParseOnly)
|
|
|
|
options = parser.parse_args(argv[1:])
|
|
options.func(options)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main(sys.argv)
|