iotests: Make qemu_nbd_popen() a contextmanager

Instead of duplicating the code to wait until the server is ready and
remember to terminate the server and wait for it, make it possible to
use like this:

    with qemu_nbd_popen('-k', sock, image):
        # Access image via qemu-nbd socket...

Only test 264 used this helper, but I had to modify the output since it
did not consistently when starting and stopping qemu-nbd.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-Id: <20200727215846.395443-3-nsoffer@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Nir Soffer 2020-07-28 00:58:44 +03:00 committed by Eric Blake
parent a2b333c018
commit b7719bcad2
3 changed files with 54 additions and 48 deletions

View File

@ -36,48 +36,32 @@ wait_step = 0.2
qemu_img_create('-f', iotests.imgfmt, disk_a, str(size))
qemu_img_create('-f', iotests.imgfmt, disk_b, str(size))
srv = qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b)
# Wait for NBD server availability
t = 0
ok = False
while t < wait_limit:
ok = qemu_io_silent_check('-f', 'raw', '-c', 'read 0 512', nbd_uri)
if ok:
break
time.sleep(wait_step)
t += wait_step
with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
vm = iotests.VM().add_drive(disk_a)
vm.launch()
vm.hmp_qemu_io('drive0', 'write 0 {}'.format(size))
assert ok
vm.qmp_log('blockdev-add', filters=[iotests.filter_qmp_testfiles],
**{'node_name': 'backup0',
'driver': 'raw',
'file': {'driver': 'nbd',
'server': {'type': 'unix', 'path': nbd_sock},
'reconnect-delay': 10}})
vm.qmp_log('blockdev-backup', device='drive0', sync='full', target='backup0',
speed=(1 * 1024 * 1024))
vm = iotests.VM().add_drive(disk_a)
vm.launch()
vm.hmp_qemu_io('drive0', 'write 0 {}'.format(size))
# Wait for some progress
t = 0
while t < wait_limit:
jobs = vm.qmp('query-block-jobs')['return']
if jobs and jobs[0]['offset'] > 0:
break
time.sleep(wait_step)
t += wait_step
vm.qmp_log('blockdev-add', filters=[iotests.filter_qmp_testfiles],
**{'node_name': 'backup0',
'driver': 'raw',
'file': {'driver': 'nbd',
'server': {'type': 'unix', 'path': nbd_sock},
'reconnect-delay': 10}})
vm.qmp_log('blockdev-backup', device='drive0', sync='full', target='backup0',
speed=(1 * 1024 * 1024))
# Wait for some progress
t = 0
while t < wait_limit:
jobs = vm.qmp('query-block-jobs')['return']
if jobs and jobs[0]['offset'] > 0:
break
time.sleep(wait_step)
t += wait_step
if jobs and jobs[0]['offset'] > 0:
log('Backup job is started')
log('Kill NBD server')
srv.kill()
srv.wait()
log('Backup job is started')
jobs = vm.qmp('query-block-jobs')['return']
if jobs and jobs[0]['offset'] < jobs[0]['len']:
@ -88,12 +72,8 @@ vm.qmp_log('block-job-set-speed', device='drive0', speed=0)
# Emulate server down time for 1 second
time.sleep(1)
log('Start NBD server')
srv = qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b)
e = vm.event_wait('BLOCK_JOB_COMPLETED')
log('Backup completed: {}'.format(e['data']['offset']))
vm.qmp_log('blockdev-del', node_name='backup0')
srv.kill()
vm.shutdown()
with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
e = vm.event_wait('BLOCK_JOB_COMPLETED')
log('Backup completed: {}'.format(e['data']['offset']))
vm.qmp_log('blockdev-del', node_name='backup0')
vm.shutdown()

View File

@ -1,3 +1,4 @@
Start NBD server
{"execute": "blockdev-add", "arguments": {"driver": "raw", "file": {"driver": "nbd", "reconnect-delay": 10, "server": {"path": "TEST_DIR/PID-nbd-sock", "type": "unix"}}, "node-name": "backup0"}}
{"return": {}}
{"execute": "blockdev-backup", "arguments": {"device": "drive0", "speed": 1048576, "sync": "full", "target": "backup0"}}
@ -11,3 +12,4 @@ Start NBD server
Backup completed: 5242880
{"execute": "blockdev-del", "arguments": {"node-name": "backup0"}}
{"return": {}}
Kill NBD server

View File

@ -28,10 +28,13 @@ import signal
import struct
import subprocess
import sys
import time
from typing import (Any, Callable, Dict, Iterable,
List, Optional, Sequence, Tuple, TypeVar)
import unittest
from contextlib import contextmanager
# pylint: disable=import-error, wrong-import-position
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
from qemu import qtest
@ -270,9 +273,30 @@ def qemu_nbd_early_pipe(*args):
return subp.returncode, output if subp.returncode else ''
@contextmanager
def qemu_nbd_popen(*args):
'''Run qemu-nbd in daemon mode and return the parent's exit code'''
return subprocess.Popen(qemu_nbd_args + ['--persistent'] + list(args))
'''Context manager running qemu-nbd within the context'''
pid_file = file_path("pid")
cmd = list(qemu_nbd_args)
cmd.extend(('--persistent', '--pid-file', pid_file))
cmd.extend(args)
log('Start NBD server')
p = subprocess.Popen(cmd)
try:
while not os.path.exists(pid_file):
if p.poll() is not None:
raise RuntimeError(
"qemu-nbd terminated with exit code {}: {}"
.format(p.returncode, ' '.join(cmd)))
time.sleep(0.01)
yield
finally:
log('Kill NBD server')
p.kill()
p.wait()
def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
'''Return True if two image files are identical'''