buildroot/support/testing/tests/package/test_ddrescue.py

95 lines
4.0 KiB
Python

import os
import infra.basetest
class TestDdrescue(infra.basetest.BRTest):
# A specific configuration is needed for testing ddrescue:
# - A kernel config fragment enables loop blk dev and device
# mapper dm-dust, which are used to simulate a failing storage
# block device.
# - dmraid user space package is needed to configure dm-dust
config = \
"""
BR2_aarch64=y
BR2_TOOLCHAIN_EXTERNAL=y
BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
BR2_LINUX_KERNEL=y
BR2_LINUX_KERNEL_CUSTOM_VERSION=y
BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.1.15"
BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/aarch64-virt/linux.config"
BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="{}"
BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y
BR2_PACKAGE_DDRESCUE=y
BR2_PACKAGE_DMRAID=y
BR2_TARGET_ROOTFS_CPIO=y
BR2_TARGET_ROOTFS_CPIO_GZIP=y
# BR2_TARGET_ROOTFS_TAR is not set
""".format(
infra.filepath("tests/package/test_ddrescue/linux-ddrescue.fragment")
)
def test_run(self):
img = os.path.join(self.builddir, "images", "rootfs.cpio.gz")
kern = os.path.join(self.builddir, "images", "Image")
self.emulator.boot(arch="aarch64",
kernel=kern,
kernel_cmdline=["console=ttyAMA0"],
options=["-M", "virt", "-cpu", "cortex-a57", "-m", "256M", "-initrd", img])
self.emulator.login()
# Test variables:
dev_img = "/tmp/dev.img"
lo_dev = "/dev/loop0"
dm_dev_name = "dust0"
dm_dev = f"/dev/mapper/{dm_dev_name}"
ddrescue_img = "/tmp/ddrescue.img"
# Test the program can execute
self.assertRunOk("ddrescue --version")
# Create a 1MB file of zeroes for initial loopback block device
self.assertRunOk(f"dd if=/dev/zero of={dev_img} bs=1M count=1")
# Setup lookback block device
self.assertRunOk(f"losetup {lo_dev} {dev_img}")
# Create and setup dm-dust to simulate a failing block device
# The dev_img file is 1MB: 2048 blocks of 512 bytes each
self.assertRunOk(f"dmsetup create {dm_dev_name} --table '0 2048 dust {lo_dev} 0 512'")
# Add few bad blocks and enable I/O error emulation
for badblock in [30, 40, 50, 60]:
self.assertRunOk(f"dmsetup message {dm_dev_name} 0 addbadblock {badblock}")
self.assertRunOk(f"dmsetup message {dm_dev_name} 0 enable")
# Show device mapper status, to make debugging easier
self.assertRunOk(f"dmsetup status {dm_dev_name}")
# A normal 'dd' is expected to fail with I/O error
cmd = f"dd if={dm_dev} of=/dev/null bs=512"
_, exit_code = self.emulator.run(cmd)
self.assertNotEqual(exit_code, 0)
# Where a normal 'dd' fails, 'ddrescue' is expected to succeed
self.assertRunOk(f"ddrescue {dm_dev} {ddrescue_img}")
# ddrescue does not normaly write any output data when there
# is I/O error on the input. The intent is to preserve any
# data that could have been read in a previous pass. There is
# one exception, when the output is a non-existing regular
# file, ddrescue will initialize it with zeroes the first
# time. Since the original image file was also including
# zeroes, the recovered image is expected to be the same as
# the original one. See ddrescue manual:
# https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Introduction
# "Ddrescue does not write zeros to the output when it finds
# bad sectors in the input, and does not truncate the output
# file if not asked to."
# https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Algorithm
# "If the output file is a regular file created by ddrescue,
# the areas marked as bad-sector will contain zeros."
self.assertRunOk(f"cmp {dev_img} {ddrescue_img}")