Michael Marineau cc341f856b fix(disk_util): Merge write_mbr into write_gpt
No need for this to be a different command.
2013-12-30 16:10:46 -08:00

508 lines
15 KiB
Python
Executable File

#!/usr/bin/python
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import argparse
import json
import os
import re
import subprocess
import sys
import uuid
# First sector we can use.
GPT_RESERVED_SECTORS = 34
class ConfigNotFound(Exception):
pass
class PartitionNotFound(Exception):
pass
class InvalidLayout(Exception):
pass
class InvalidAdjustment(Exception):
pass
def LoadPartitionConfig(options):
"""Loads a partition tables configuration file into a Python object.
Args:
options: Flags passed to the script
Returns:
Object containing disk layout configuration
"""
valid_keys = set(('_comment', 'metadata', 'layouts'))
valid_layout_keys = set((
'_comment', 'type', 'num', 'label', 'blocks', 'block_size', 'fs_blocks',
'fs_block_size', 'features', 'uuid', 'alignment'))
filename = options.disk_layout_file
if not os.path.exists(filename):
raise ConfigNotFound('Partition config %s was not found!' % filename)
with open(filename) as f:
config = json.load(f)
try:
metadata = config['metadata']
for key in ('alignment', 'block_size', 'fs_block_size'):
metadata[key] = int(metadata[key])
# Sometimes qemu-img expects disks sizes aligned to 64k
align_bytes = metadata['alignment'] * metadata['block_size']
if align_bytes < 65536 or align_bytes % 65536 != 0:
raise InvalidLayout('Invalid alignment, 64KB or better required')
unknown_keys = set(config.keys()) - valid_keys
if unknown_keys:
raise InvalidLayout('Unknown items: %r' % unknown_keys)
if len(config['layouts']) <= 0:
raise InvalidLayout('Missing "layouts" entries')
for layout_name, layout in config['layouts'].items():
for part in layout:
unknown_keys = set(part.keys()) - valid_layout_keys
if unknown_keys:
raise InvalidLayout('Unknown items in layout %s: %r' %
(layout_name, unknown_keys))
if part['type'] != 'blank':
for s in ('num', 'label'):
if not s in part:
raise InvalidLayout('Layout "%s" missing "%s"' % (layout_name, s))
part['alignment'] = int(part.get('alignment', metadata['alignment']))
part['blocks'] = int(part['blocks'])
part['bytes'] = part['blocks'] * metadata['block_size']
if 'fs_blocks' in part:
part['fs_blocks'] = int(part['fs_blocks'])
part['fs_bytes'] = part['fs_blocks'] * metadata['fs_block_size']
if part['fs_bytes'] > part['bytes']:
raise InvalidLayout(
'Filesystem may not be larger than partition: %s %s: %d > %d' %
(layout_name, part['label'], part['fs_bytes'], part['bytes']))
if 'uuid' in part:
try:
# double check the string formatting
part['uuid'] = str(uuid.UUID(part['uuid']))
except ValueError as e:
raise InvalidLayout('Invalid uuid %r: %s' % (part['uuid'], e))
else:
part['uuid'] = str(uuid.uuid4())
except KeyError as e:
raise InvalidLayout('Layout is missing required entries: %s' % e)
return config
def GetPartitionTable(options, config):
"""Generates requested image_type layout from a layout configuration.
This loads the base table and then overlays the requested layout over
the base layout.
Args:
options: Flags passed to the script
config: Partition configuration file object
Returns:
Object representing a selected partition table
"""
partitions = config['layouts']['base']
metadata = config['metadata']
image_type = options.disk_layout
if image_type != 'base':
for partition_t in config['layouts'][image_type]:
for partition in partitions:
if partition['type'] == 'blank' or partition_t['type'] == 'blank':
continue
if partition_t['num'] == partition['num']:
for k, v in partition_t.items():
partition[k] = v
for adjustment_str in options.adjust_part.split():
adjustment = adjustment_str.split(':')
if len(adjustment) < 2:
raise InvalidAdjustment('Adjustment specified was incomplete')
label = adjustment[0]
operator = adjustment[1][0]
operand = adjustment[1][1:]
ApplyPartitionAdjustment(partitions, metadata, label, operator, operand)
return partitions
def ApplyPartitionAdjustment(partitions, metadata, label, operator, operand):
"""Applies an adjustment to a partition specified by label
Args:
partitions: Partition table to modify
metadata: Partition table metadata
label: The label of the partition to adjust
operator: Type of adjustment (+/-/=)
operand: How much to adjust by
"""
partition = GetPartitionByLabel(partitions, label)
operand_digits = re.sub('\D', '', operand)
size_factor = block_factor = 1
suffix = operand[len(operand_digits):]
if suffix:
size_factors = { 'B': 0, 'K': 1, 'M': 2, 'G': 3, 'T': 4, }
try:
size_factor = size_factors[suffix[0].upper()]
except KeyError:
raise InvalidAdjustment('Unknown size type %s' % suffix)
if size_factor == 0 and len(suffix) > 1:
raise InvalidAdjustment('Unknown size type %s' % suffix)
block_factors = { '': 1024, 'B': 1000, 'IB': 1024, }
try:
block_factor = block_factors[suffix[1:].upper()]
except KeyError:
raise InvalidAdjustment('Unknown size type %s' % suffix)
operand_bytes = int(operand_digits) * pow(block_factor, size_factor)
if operand_bytes % metadata['block_size'] == 0:
operand_blocks = operand_bytes / metadata['block_size']
else:
raise InvalidAdjustment('Adjustment size not divisible by block size')
if operator == '+':
partition['blocks'] += operand_blocks
partition['bytes'] += operand_bytes
elif operator == '-':
partition['blocks'] -= operand_blocks
partition['bytes'] -= operand_bytes
elif operator == '=':
partition['blocks'] = operand_blocks
partition['bytes'] = operand_bytes
else:
raise ValueError('unknown operator %s' % operator)
if partition['type'] == 'rootfs':
# If we're adjusting a rootFS partition, we assume the full partition size
# specified is being used for the filesytem, minus the space reserved for
# the hashpad.
partition['fs_bytes'] = partition['bytes']
partition['fs_blocks'] = partition['fs_bytes'] / metadata['fs_block_size']
partition['blocks'] = int(partition['blocks'] * 1.15)
partition['bytes'] = partition['blocks'] * metadata['block_size']
def GetPartitionTableFromConfig(options):
"""Loads a partition table and returns a given partition table type
Args:
options: Flags passed to the script
Returns:
A list defining all known partitions.
"""
config = LoadPartitionConfig(options)
partitions = GetPartitionTable(options, config)
return partitions
def WritePartitionTable(options):
"""Writes the given partition table to a disk image or device.
Args:
options: Flags passed to the script
"""
def Cgpt(*args):
subprocess.check_call(['cgpt'] + [str(a) for a in args])
def Align(count, alignment):
offset = count % alignment
if offset:
count += alignment - offset
return count
config = LoadPartitionConfig(options)
partitions = GetPartitionTable(options, config)
disk_block_count = GPT_RESERVED_SECTORS
for partition in partitions:
disk_block_count = Align(disk_block_count, partition['alignment'])
disk_block_count += partition['blocks']
disk_block_count += GPT_RESERVED_SECTORS
# Sometimes qemu-img expects disks sizes aligned to 64k
disk_block_count = Align(disk_block_count, config['metadata']['alignment'])
Cgpt('create', '-c', '-s', disk_block_count, options.disk_image)
sector = GPT_RESERVED_SECTORS
esp_number = None
for partition in partitions:
sector = Align(sector, partition['alignment'])
if partition['type'] != 'blank':
Cgpt('add', '-i', partition['num'],
'-b', sector,
'-s', partition['blocks'],
'-t', partition['type'],
'-l', partition['label'],
'-u', partition['uuid'],
options.disk_image)
if partition['type'] == 'efi':
esp_number = partition['num']
sector += partition['blocks']
if esp_number is None:
raise InvalidLayout('Table does not include an EFI partition.')
if options.mbr_boot_code:
Cgpt('boot', '-p',
'-b', options.mbr_boot_code,
'-i', esp_number,
options.disk_image)
Cgpt('show', options.disk_image)
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
"""
for partition in partitions:
if partition['type'] == 'blank':
continue
if partition['num'] == int(num):
return partition
raise PartitionNotFound('Partition not found')
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:
if 'label' not in partition:
continue
if partition['label'] == label:
return partition
raise PartitionNotFound('Partition not found')
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 = 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 = 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 partition in partitions:
if partition['bytes'] < 1024 * 1024:
size = '%d bytes' % partition['bytes']
else:
size = '%d MB' % (partition['bytes'] / 1024 / 1024)
if 'label' in partition:
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' % (partition['label'], fs_size, size)
else:
print '%s - %s' % (partition['label'], size)
else:
print 'blank - %s' % size
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__), 'legacy_disk_layout.json'))
default_layout_type = os.environ.get('DISK_LAYOUT_TYPE', 'base')
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('--adjust_part', default='',
help='adjust partition sizes')
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 gpt to new image')
a.add_argument('--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('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)