diskimage-builder/diskimage_builder/block_device/tests/test_mbr.py
Ian Wienand 5d5fa06e5c Sync after writing partition table
We introduced the "settle" in
I90103b59357edebbac7a641e8980cb282d37561b thinking that maybe kpartx
had not finished writing the partition.  This probably wasn't a bad
first assumption, since we used to have this -- but is seems
insufficient.

The other failiure here seems to be if kpartx hasn't actually seen the
updated partition table in the image, so it has correctly (in it's
mind) not mounted the partition.

Looking at strace of fdisk run manually on a loopback, it will do a
fsync on the raw device after writing and then a global sync as it
exits.

This replicates this; we flush and fsync in mbr.py in the exit handler
after writing the partition, before closing the file (i've updated one
of the unit tests to double-check the call).  In the partitioning.py
caller we execute a sync call too.

Since it does seem unlikely the "-s" option of kpartx is not working,
I've removed the udev settle work-around too.

Change-Id: Ia77a0ffe4c76854b326ed76490479d9c691b49aa
Partial-Bug: #1698337
2017-06-19 17:13:36 +10:00

165 lines
6.1 KiB
Python

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import fixtures
import logging
import mock
import os
import subprocess
import diskimage_builder.block_device.tests.test_base as tb
from diskimage_builder.block_device.level0.localloop import image_create
from diskimage_builder.block_device.level1.mbr import MBR
logger = logging.getLogger(__name__)
class TestMBR(tb.TestBase):
disk_size_10M = 10 * 1024 * 1024
disk_size_1G = 1024 * 1024 * 1024
def _get_path_for_partx(self):
"""Searches and sets the path for partx
Because different distributions store the partx binary
at different places, there is the need to look for it.
"""
dirs = ["/bin", "/usr/bin", "/sbin", "/usr/sbin"]
for d in dirs:
if os.path.exists(os.path.join(d, "partx")):
return os.path.join(d, "partx")
return
# If not found, try without path.
return "partx"
def setUp(self):
super(TestMBR, self).setUp()
self.tmp_dir = fixtures.TempDir()
self.useFixture(self.tmp_dir)
self.image_path = os.path.join(self.tmp_dir.path, "image.raw")
image_create(self.image_path, TestMBR.disk_size_1G)
logger.debug("Temp image is %s", self.image_path)
self.partx_args = [self._get_path_for_partx(), "--raw",
"--output", "NR,START,END,TYPE,FLAGS,SCHEME",
"-g", "-b", "-", self.image_path]
def _run_partx(self, image_path):
logger.info("Running command: %s", self.partx_args)
return subprocess.check_output(self.partx_args).decode("ascii")
@mock.patch('os.fsync', wraps=os.fsync)
def test_one_ext_partition(self, mock_os_fsync):
"""Creates one partition and check correctness with partx."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024) as mbr:
mbr.add_partition(False, False, TestMBR.disk_size_10M, 0x83)
# the exit handler of MBR should have synced the raw device
# before exit
mock_os_fsync.assert_called()
output = self._run_partx(self.image_path)
self.assertEqual(
"1 2048 2097151 0xf 0x0 dos\n"
"5 4096 24575 0x83 0x0 dos\n", output)
def test_zero_partitions(self):
"""Creates no partition and check correctness with partx."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024):
pass
output = self._run_partx(self.image_path)
self.assertEqual("", output)
def test_many_ext_partitions(self):
"""Creates many partition and check correctness with partx."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024) as mbr:
for nr in range(0, 64):
mbr.add_partition(False, False, TestMBR.disk_size_10M, 0x83)
output = self._run_partx(self.image_path)
lines = output.split("\n")
self.assertEqual(66, len(lines))
self.assertEqual(
"1 2048 2097151 0xf 0x0 dos", lines[0])
start_block = 4096
end_block = start_block + TestMBR.disk_size_10M / 512 - 1
for nr in range(1, 65):
fields = lines[nr].split(" ")
self.assertEqual(6, len(fields))
self.assertEqual(nr + 4, int(fields[0]))
self.assertEqual(start_block, int(fields[1]))
self.assertEqual(end_block, int(fields[2]))
self.assertEqual("0x83", fields[3])
self.assertEqual("0x0", fields[4])
self.assertEqual("dos", fields[5])
start_block += 22528
end_block = start_block + TestMBR.disk_size_10M / 512 - 1
def test_one_pri_partition(self):
"""Creates one primary partition and check correctness with partx."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024) as mbr:
mbr.add_partition(True, False, TestMBR.disk_size_10M, 0x83)
output = self._run_partx(self.image_path)
self.assertEqual(
"1 2048 22527 0x83 0x0 dos\n", output)
def test_three_pri_partition(self):
"""Creates three primary partition and check correctness with partx."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024) as mbr:
for _ in range(3):
mbr.add_partition(True, False, TestMBR.disk_size_10M, 0x83)
output = self._run_partx(self.image_path)
self.assertEqual(
"1 2048 22527 0x83 0x0 dos\n"
"2 22528 43007 0x83 0x0 dos\n"
"3 43008 63487 0x83 0x0 dos\n", output)
def test_many_pri_and_ext_partition(self):
"""Creates many primary and extended partitions."""
with MBR(self.image_path, TestMBR.disk_size_1G, 1024 * 1024) as mbr:
# Create three primary partitions
for _ in range(3):
mbr.add_partition(True, False, TestMBR.disk_size_10M, 0x83)
for _ in range(7):
mbr.add_partition(False, False, TestMBR.disk_size_10M, 0x83)
output = self._run_partx(self.image_path)
self.assertEqual(
"1 2048 22527 0x83 0x0 dos\n" # Primary 1
"2 22528 43007 0x83 0x0 dos\n" # Primary 2
"3 43008 63487 0x83 0x0 dos\n" # Primary 3
"4 63488 2097151 0xf 0x0 dos\n" # Extended
"5 65536 86015 0x83 0x0 dos\n" # Extended Partition 1
"6 88064 108543 0x83 0x0 dos\n" # Extended Partition 2
"7 110592 131071 0x83 0x0 dos\n" # ...
"8 133120 153599 0x83 0x0 dos\n"
"9 155648 176127 0x83 0x0 dos\n"
"10 178176 198655 0x83 0x0 dos\n"
"11 200704 221183 0x83 0x0 dos\n", output)