Merge patch series "Provide a class for building filesystem images"

Simon Glass <sjg@chromium.org> says:

Create a class around mk_fs() to handle the common tasks of image
creation, such as managing scratch directories and cleaning up.

Start with a few small cleanups to mk_fs(), then convert the helper
to use a class.

Link: https://lore.kernel.org/r/20260309151307.831537-1-sjg@chromium.org
This commit is contained in:
Tom Rini 2026-03-23 09:18:38 -06:00
commit e1197b0cc2

View File

@ -7,9 +7,97 @@
import re
import os
import shutil
from subprocess import call, check_call, check_output, CalledProcessError
from subprocess import DEVNULL
import tempfile
def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000):
# size_gran (int): Size granularity of file system image in bytes
SIZE_GRAN = 1 << 20
class FsHelper:
"""Creating a filesystem containing test files
Usage:
with FsHelper(ubman.config, 'ext4', 10, 'mmc1') as fsh:
# create files in the self.srcdir directory
fsh.mk_fs()
# Now use the filesystem
# The filesystem and srcdir are erased after the 'with' statement.
It is also possible to use an existing srcdir:
with FsHelper(ubman.config, 'fat32', 10, 'usb2') as fsh:
fsh.srcdir = src_dir
fsh.mk_fs()
...
Properties:
fs_img (str): Filename for the filesystem image
"""
def __init__(self, config, fs_type, size_mb, prefix):
"""Set up a new object
Args:
config (u_boot_config): U-Boot configuration
fs_type (str): File system type: one of ext2, ext3, ext4, vfat,
fat12, fat16, fat32, exfat, fs_generic (which means vfat)
size_mb (int): Size of file system in MB
prefix (str): Prefix string of volume's file name
"""
if fs_type not in ['fat12', 'fat16', 'fat32', 'vfat',
'ext2', 'ext3', 'ext4',
'exfat', 'fs_generic']:
raise ValueError(f"Unsupported filesystem type '{fs_type}'")
self.config = config
self.fs_type = fs_type
self.size_mb = size_mb
self.prefix = prefix
self.quiet = True
self.fs_img = None
self.tmpdir = None
self.srcdir = None
self._do_cleanup = False
def mk_fs(self):
"""Make a new filesystem and copy in the files"""
self.setup()
self._do_cleanup = True
self.fs_img = mk_fs(self.config, self.fs_type, self.size_mb << 20,
self.prefix, self.srcdir, quiet=self.quiet)
def setup(self):
"""Set up the srcdir ready to receive files"""
if not self.srcdir:
if self.config:
self.srcdir = os.path.join(self.config.persistent_data_dir,
f'{self.prefix}.{self.fs_type}.tmp')
if os.path.exists(self.srcdir):
shutil.rmtree(self.srcdir)
os.mkdir(self.srcdir)
else:
self.tmpdir = tempfile.TemporaryDirectory('fs_helper')
self.srcdir = self.tmpdir.name
def cleanup(self):
"""Remove created image"""
if self.tmpdir:
self.tmpdir.cleanup()
if self._do_cleanup:
os.remove(self.fs_img)
def __enter__(self):
self.setup()
return self
def __exit__(self, extype, value, traceback):
self.cleanup()
def mk_fs(config, fs_type, size, prefix, src_dir=None, fs_img=None, quiet=False):
"""Create a file system volume
Args:
@ -18,12 +106,16 @@ def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000):
size (int): Size of file system in bytes
prefix (str): Prefix string of volume's file name
src_dir (str): Root directory to use, or None for none
size_gran (int): Size granularity of file system image in bytes
fs_img (str or None): Leaf filename for image, or None to use a
default name. The image is always placed under
persistent_data_dir.
quiet (bool): Suppress non-error output
Raises:
CalledProcessError: if any error occurs when creating the filesystem
"""
fs_img = f'{prefix}.{fs_type}.img'
if not fs_img:
fs_img = f'{prefix}.{fs_type}.img'
fs_img = os.path.join(config.persistent_data_dir, fs_img)
if fs_type == 'fat12':
@ -48,7 +140,7 @@ def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000):
elif fs_lnxtype != 'vfat' and fs_lnxtype != 'exfat':
raise ValueError(f'src_dir not implemented for fs {fs_lnxtype}')
count = (size + size_gran - 1) // size_gran
count = (size + SIZE_GRAN - 1) // SIZE_GRAN
# Some distributions do not add /sbin to the default PATH, where mkfs lives
if '/sbin' not in os.environ["PATH"].split(os.pathsep):
@ -56,16 +148,19 @@ def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000):
try:
check_call(f'rm -f {fs_img}', shell=True)
check_call(f'truncate -s $(( {size_gran} * {count} )) {fs_img}',
check_call(f'truncate -s $(( {SIZE_GRAN} * {count} )) {fs_img}',
shell=True)
check_call(f'mkfs.{fs_lnxtype} {mkfs_opt} {fs_img}', shell=True)
check_call(f'mkfs.{fs_lnxtype} {mkfs_opt} {fs_img}', shell=True,
stdout=DEVNULL if quiet else None)
if fs_type == 'ext4':
sb_content = check_output(f'tune2fs -l {fs_img}',
shell=True).decode()
if 'metadata_csum' in sb_content:
check_call(f'tune2fs -O ^metadata_csum {fs_img}', shell=True)
elif fs_lnxtype == 'vfat' and src_dir:
check_call(f'mcopy -i {fs_img} -vsmpQ {src_dir}/* ::/', shell=True)
flags = f"-smpQ{'' if quiet else 'v'}"
check_call(f'mcopy -i {fs_img} {flags} {src_dir}/* ::/',
shell=True)
elif fs_lnxtype == 'exfat' and src_dir:
check_call(f'fattools cp {src_dir}/* {fs_img}', shell=True)
return fs_img
@ -75,7 +170,7 @@ def mk_fs(config, fs_type, size, prefix, src_dir=None, size_gran = 0x100000):
def setup_image(ubman, devnum, part_type, img_size=20, second_part=False,
basename='mmc'):
"""Create a disk image with a single partition
"""Create a disk image with one or two partitions
Args:
ubman (ConsoleBase): Console to use