poky/scripts/lib/wic/partition.py
Paul Barker 36575a9493 wic: Copy rootfs dir if fstab needs updating
By default, wic updates the /etc/fstab in the rootfs to include details
of additional partitions described in the selected wks file. If this
modification is performed in place, other tasks which create an image
file from the rootfs directory (e.g. do_image_tar and do_image_ext4)
will pick up the modified fstab file which would not be appropriate for
those images as they do not include the additional partitions described
in the wks file. wic does undo modifications to the fstab file once it
has finished creating the filesystem image, however this leaves open a
race condition if one of the other tasks reads the contents of the fstab
file from the rootfs directory between the point where wic modifies the
fstab file and the point where wic restores the files original content.

This could be solved by adding a lockfile for tasks which use the rootfs
directory to ensure that no other such task is reading the rootfs
directory while do_image_wic is running. This would serialize several
do_image_* tasks and result in slower builds, especially for large
images. Another drawback of this solution is that it is hard to
selectively optimise - adding lockfiles to do_image_* tasks would result
in these tasks always being serialized even if no fstab modification
will take place.

An alternative solution is to copy the rootfs directory when fstab needs
to be modified. The code to do this in wic already exists as it is
needed when including or excluding content in the rootfs. This still
results in an impact on build times but the copy uses hardlinks if
possible (so little data is actually copied) and we can make selective
optimisations to improve things. The rootfs copy will only take place if
fstab modification is required (or if it was already needed to include
or exclude rootfs content). We can also follow up with further
optimisations after this commit. So this second solution is chosen.

Fixes [Yocto #13994]

(From OE-Core rev: ce682a73b7447652f898ce1d1d0416a456df5416)

Signed-off-by: Paul Barker <pbarker@konsulko.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2021-01-20 22:46:18 +00:00

435 lines
16 KiB
Python

#
# Copyright (c) 2013-2016 Intel Corporation.
#
# SPDX-License-Identifier: GPL-2.0-only
#
# DESCRIPTION
# This module provides the OpenEmbedded partition object definitions.
#
# AUTHORS
# Tom Zanussi <tom.zanussi (at] linux.intel.com>
# Ed Bartosh <ed.bartosh> (at] linux.intel.com>
import logging
import os
import uuid
from wic import WicError
from wic.misc import exec_cmd, exec_native_cmd, get_bitbake_var
from wic.pluginbase import PluginMgr
logger = logging.getLogger('wic')
class Partition():
def __init__(self, args, lineno):
self.args = args
self.active = args.active
self.align = args.align
self.disk = args.disk
self.device = None
self.extra_space = args.extra_space
self.exclude_path = args.exclude_path
self.include_path = args.include_path
self.change_directory = args.change_directory
self.fsopts = args.fsopts
self.fstype = args.fstype
self.label = args.label
self.use_label = args.use_label
self.mkfs_extraopts = args.mkfs_extraopts
self.mountpoint = args.mountpoint
self.no_table = args.no_table
self.num = None
self.offset = args.offset
self.overhead_factor = args.overhead_factor
self.part_name = args.part_name
self.part_type = args.part_type
self.rootfs_dir = args.rootfs_dir
self.size = args.size
self.fixed_size = args.fixed_size
self.source = args.source
self.sourceparams = args.sourceparams
self.system_id = args.system_id
self.use_uuid = args.use_uuid
self.uuid = args.uuid
self.fsuuid = args.fsuuid
self.type = args.type
self.updated_fstab_path = None
self.lineno = lineno
self.source_file = ""
def get_extra_block_count(self, current_blocks):
"""
The --size param is reflected in self.size (in kB), and we already
have current_blocks (1k) blocks, calculate and return the
number of (1k) blocks we need to add to get to --size, 0 if
we're already there or beyond.
"""
logger.debug("Requested partition size for %s: %d",
self.mountpoint, self.size)
if not self.size:
return 0
requested_blocks = self.size
logger.debug("Requested blocks %d, current_blocks %d",
requested_blocks, current_blocks)
if requested_blocks > current_blocks:
return requested_blocks - current_blocks
else:
return 0
def get_rootfs_size(self, actual_rootfs_size=0):
"""
Calculate the required size of rootfs taking into consideration
--size/--fixed-size flags as well as overhead and extra space, as
specified in kickstart file. Raises an error if the
`actual_rootfs_size` is larger than fixed-size rootfs.
"""
if self.fixed_size:
rootfs_size = self.fixed_size
if actual_rootfs_size > rootfs_size:
raise WicError("Actual rootfs size (%d kB) is larger than "
"allowed size %d kB" %
(actual_rootfs_size, rootfs_size))
else:
extra_blocks = self.get_extra_block_count(actual_rootfs_size)
if extra_blocks < self.extra_space:
extra_blocks = self.extra_space
rootfs_size = actual_rootfs_size + extra_blocks
rootfs_size *= self.overhead_factor
logger.debug("Added %d extra blocks to %s to get to %d total blocks",
extra_blocks, self.mountpoint, rootfs_size)
return rootfs_size
@property
def disk_size(self):
"""
Obtain on-disk size of partition taking into consideration
--size/--fixed-size options.
"""
return self.fixed_size if self.fixed_size else self.size
def prepare(self, creator, cr_workdir, oe_builddir, rootfs_dir,
bootimg_dir, kernel_dir, native_sysroot, updated_fstab_path):
"""
Prepare content for individual partitions, depending on
partition command parameters.
"""
self.updated_fstab_path = updated_fstab_path
if not self.source:
if not self.size and not self.fixed_size:
raise WicError("The %s partition has a size of zero. Please "
"specify a non-zero --size/--fixed-size for that "
"partition." % self.mountpoint)
if self.fstype == "swap":
self.prepare_swap_partition(cr_workdir, oe_builddir,
native_sysroot)
self.source_file = "%s/fs.%s" % (cr_workdir, self.fstype)
else:
if self.fstype == 'squashfs':
raise WicError("It's not possible to create empty squashfs "
"partition '%s'" % (self.mountpoint))
rootfs = "%s/fs_%s.%s.%s" % (cr_workdir, self.label,
self.lineno, self.fstype)
if os.path.isfile(rootfs):
os.remove(rootfs)
prefix = "ext" if self.fstype.startswith("ext") else self.fstype
method = getattr(self, "prepare_empty_partition_" + prefix)
method(rootfs, oe_builddir, native_sysroot)
self.source_file = rootfs
return
plugins = PluginMgr.get_plugins('source')
if self.source not in plugins:
raise WicError("The '%s' --source specified for %s doesn't exist.\n\t"
"See 'wic list source-plugins' for a list of available"
" --sources.\n\tSee 'wic help source-plugins' for "
"details on adding a new source plugin." %
(self.source, self.mountpoint))
srcparams_dict = {}
if self.sourceparams:
# Split sourceparams string of the form key1=val1[,key2=val2,...]
# into a dict. Also accepts valueless keys i.e. without =
splitted = self.sourceparams.split(',')
srcparams_dict = dict(par.split('=', 1) for par in splitted if par)
plugin = PluginMgr.get_plugins('source')[self.source]
plugin.do_configure_partition(self, srcparams_dict, creator,
cr_workdir, oe_builddir, bootimg_dir,
kernel_dir, native_sysroot)
plugin.do_stage_partition(self, srcparams_dict, creator,
cr_workdir, oe_builddir, bootimg_dir,
kernel_dir, native_sysroot)
plugin.do_prepare_partition(self, srcparams_dict, creator,
cr_workdir, oe_builddir, bootimg_dir,
kernel_dir, rootfs_dir, native_sysroot)
plugin.do_post_partition(self, srcparams_dict, creator,
cr_workdir, oe_builddir, bootimg_dir,
kernel_dir, rootfs_dir, native_sysroot)
# further processing required Partition.size to be an integer, make
# sure that it is one
if not isinstance(self.size, int):
raise WicError("Partition %s internal size is not an integer. "
"This a bug in source plugin %s and needs to be fixed." %
(self.mountpoint, self.source))
if self.fixed_size and self.size > self.fixed_size:
raise WicError("File system image of partition %s is "
"larger (%d kB) than its allowed size %d kB" %
(self.mountpoint, self.size, self.fixed_size))
def prepare_rootfs(self, cr_workdir, oe_builddir, rootfs_dir,
native_sysroot, real_rootfs = True, pseudo_dir = None):
"""
Prepare content for a rootfs partition i.e. create a partition
and fill it from a /rootfs dir.
Currently handles ext2/3/4, btrfs, vfat and squashfs.
"""
rootfs = "%s/rootfs_%s.%s.%s" % (cr_workdir, self.label,
self.lineno, self.fstype)
if os.path.isfile(rootfs):
os.remove(rootfs)
p_prefix = os.environ.get("PSEUDO_PREFIX", "%s/usr" % native_sysroot)
if (pseudo_dir):
# Canonicalize the ignore paths. This corresponds to
# calling oe.path.canonicalize(), which is used in bitbake.conf.
ignore_paths = [rootfs] + (get_bitbake_var("PSEUDO_IGNORE_PATHS") or "").split(",")
canonical_paths = []
for path in ignore_paths:
if "$" not in path:
trailing_slash = path.endswith("/") and "/" or ""
canonical_paths.append(os.path.realpath(path) + trailing_slash)
ignore_paths = ",".join(canonical_paths)
pseudo = "export PSEUDO_PREFIX=%s;" % p_prefix
pseudo += "export PSEUDO_LOCALSTATEDIR=%s;" % pseudo_dir
pseudo += "export PSEUDO_PASSWD=%s;" % rootfs_dir
pseudo += "export PSEUDO_NOSYMLINKEXP=1;"
pseudo += "export PSEUDO_IGNORE_PATHS=%s;" % ignore_paths
pseudo += "%s " % get_bitbake_var("FAKEROOTCMD")
else:
pseudo = None
if not self.size and real_rootfs:
# The rootfs size is not set in .ks file so try to get it
# from bitbake variable
rsize_bb = get_bitbake_var('ROOTFS_SIZE')
rdir = get_bitbake_var('IMAGE_ROOTFS')
if rsize_bb and rdir == rootfs_dir:
# Bitbake variable ROOTFS_SIZE is calculated in
# Image._get_rootfs_size method from meta/lib/oe/image.py
# using IMAGE_ROOTFS_SIZE, IMAGE_ROOTFS_ALIGNMENT,
# IMAGE_OVERHEAD_FACTOR and IMAGE_ROOTFS_EXTRA_SPACE
self.size = int(round(float(rsize_bb)))
else:
# Bitbake variable ROOTFS_SIZE is not defined so compute it
# from the rootfs_dir size using the same logic found in
# get_rootfs_size() from meta/classes/image.bbclass
du_cmd = "du -ks %s" % rootfs_dir
out = exec_cmd(du_cmd)
self.size = int(out.split()[0])
prefix = "ext" if self.fstype.startswith("ext") else self.fstype
method = getattr(self, "prepare_rootfs_" + prefix)
method(rootfs, oe_builddir, rootfs_dir, native_sysroot, pseudo)
self.source_file = rootfs
# get the rootfs size in the right units for kickstart (kB)
du_cmd = "du -Lbks %s" % rootfs
out = exec_cmd(du_cmd)
self.size = int(out.split()[0])
def prepare_rootfs_ext(self, rootfs, oe_builddir, rootfs_dir,
native_sysroot, pseudo):
"""
Prepare content for an ext2/3/4 rootfs partition.
"""
du_cmd = "du -ks %s" % rootfs_dir
out = exec_cmd(du_cmd)
actual_rootfs_size = int(out.split()[0])
rootfs_size = self.get_rootfs_size(actual_rootfs_size)
with open(rootfs, 'w') as sparse:
os.ftruncate(sparse.fileno(), rootfs_size * 1024)
extraopts = self.mkfs_extraopts or "-F -i 8192"
label_str = ""
if self.label:
label_str = "-L %s" % self.label
mkfs_cmd = "mkfs.%s %s %s %s -U %s -d %s" % \
(self.fstype, extraopts, rootfs, label_str, self.fsuuid, rootfs_dir)
exec_native_cmd(mkfs_cmd, native_sysroot, pseudo=pseudo)
mkfs_cmd = "fsck.%s -pvfD %s" % (self.fstype, rootfs)
exec_native_cmd(mkfs_cmd, native_sysroot, pseudo=pseudo)
def prepare_rootfs_btrfs(self, rootfs, oe_builddir, rootfs_dir,
native_sysroot, pseudo):
"""
Prepare content for a btrfs rootfs partition.
"""
du_cmd = "du -ks %s" % rootfs_dir
out = exec_cmd(du_cmd)
actual_rootfs_size = int(out.split()[0])
rootfs_size = self.get_rootfs_size(actual_rootfs_size)
with open(rootfs, 'w') as sparse:
os.ftruncate(sparse.fileno(), rootfs_size * 1024)
label_str = ""
if self.label:
label_str = "-L %s" % self.label
mkfs_cmd = "mkfs.%s -b %d -r %s %s %s -U %s %s" % \
(self.fstype, rootfs_size * 1024, rootfs_dir, label_str,
self.mkfs_extraopts, self.fsuuid, rootfs)
exec_native_cmd(mkfs_cmd, native_sysroot, pseudo=pseudo)
def prepare_rootfs_msdos(self, rootfs, oe_builddir, rootfs_dir,
native_sysroot, pseudo):
"""
Prepare content for a msdos/vfat rootfs partition.
"""
du_cmd = "du -bks %s" % rootfs_dir
out = exec_cmd(du_cmd)
blocks = int(out.split()[0])
rootfs_size = self.get_rootfs_size(blocks)
label_str = "-n boot"
if self.label:
label_str = "-n %s" % self.label
size_str = ""
if self.fstype == 'msdos':
size_str = "-F 16" # FAT 16
extraopts = self.mkfs_extraopts or '-S 512'
dosfs_cmd = "mkdosfs %s -i %s %s %s -C %s %d" % \
(label_str, self.fsuuid, size_str, extraopts, rootfs,
rootfs_size)
exec_native_cmd(dosfs_cmd, native_sysroot)
mcopy_cmd = "mcopy -i %s -s %s/* ::/" % (rootfs, rootfs_dir)
exec_native_cmd(mcopy_cmd, native_sysroot)
chmod_cmd = "chmod 644 %s" % rootfs
exec_cmd(chmod_cmd)
prepare_rootfs_vfat = prepare_rootfs_msdos
def prepare_rootfs_squashfs(self, rootfs, oe_builddir, rootfs_dir,
native_sysroot, pseudo):
"""
Prepare content for a squashfs rootfs partition.
"""
extraopts = self.mkfs_extraopts or '-noappend'
squashfs_cmd = "mksquashfs %s %s %s" % \
(rootfs_dir, rootfs, extraopts)
exec_native_cmd(squashfs_cmd, native_sysroot, pseudo=pseudo)
def prepare_empty_partition_ext(self, rootfs, oe_builddir,
native_sysroot):
"""
Prepare an empty ext2/3/4 partition.
"""
size = self.disk_size
with open(rootfs, 'w') as sparse:
os.ftruncate(sparse.fileno(), size * 1024)
extraopts = self.mkfs_extraopts or "-i 8192"
label_str = ""
if self.label:
label_str = "-L %s" % self.label
mkfs_cmd = "mkfs.%s -F %s %s -U %s %s" % \
(self.fstype, extraopts, label_str, self.fsuuid, rootfs)
exec_native_cmd(mkfs_cmd, native_sysroot)
def prepare_empty_partition_btrfs(self, rootfs, oe_builddir,
native_sysroot):
"""
Prepare an empty btrfs partition.
"""
size = self.disk_size
with open(rootfs, 'w') as sparse:
os.ftruncate(sparse.fileno(), size * 1024)
label_str = ""
if self.label:
label_str = "-L %s" % self.label
mkfs_cmd = "mkfs.%s -b %d %s -U %s %s %s" % \
(self.fstype, self.size * 1024, label_str, self.fsuuid,
self.mkfs_extraopts, rootfs)
exec_native_cmd(mkfs_cmd, native_sysroot)
def prepare_empty_partition_msdos(self, rootfs, oe_builddir,
native_sysroot):
"""
Prepare an empty vfat partition.
"""
blocks = self.disk_size
label_str = "-n boot"
if self.label:
label_str = "-n %s" % self.label
size_str = ""
if self.fstype == 'msdos':
size_str = "-F 16" # FAT 16
extraopts = self.mkfs_extraopts or '-S 512'
dosfs_cmd = "mkdosfs %s -i %s %s %s -C %s %d" % \
(label_str, self.fsuuid, extraopts, size_str, rootfs,
blocks)
exec_native_cmd(dosfs_cmd, native_sysroot)
chmod_cmd = "chmod 644 %s" % rootfs
exec_cmd(chmod_cmd)
prepare_empty_partition_vfat = prepare_empty_partition_msdos
def prepare_swap_partition(self, cr_workdir, oe_builddir, native_sysroot):
"""
Prepare a swap partition.
"""
path = "%s/fs.%s" % (cr_workdir, self.fstype)
with open(path, 'w') as sparse:
os.ftruncate(sparse.fileno(), self.size * 1024)
label_str = ""
if self.label:
label_str = "-L %s" % self.label
mkswap_cmd = "mkswap %s -U %s %s" % (label_str, self.fsuuid, path)
exec_native_cmd(mkswap_cmd, native_sysroot)