openstack/deb-cinder
Code Issues Proposed changes

Check whether O_DIRECT is supported to iflag and oflag separately

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The problem is when this is used for volume clear and the clear method
specifies use of the 'zero' option (/dev/zero) setting iflag direct is
not a valid option for that input file, but oflag direct is a valid
option for output file, so we should check iflag and oflag separately.

Change-Id: I4b627e95b68d56e3011cddc577c62fad0c384dba
Close-Bug: 1318748
This commit is contained in:
vitas.yuzhou 2014-05-13 02:57:48 +08:00
parent c8446dc57a
commit 2448ffd53b
2 changed files with 26 additions and 8 deletions
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17
cinder/tests/test_volume_utils.py
View File

@ -25,6 +25,7 @@ from cinder import db
from cinder import exception
from cinder.openstack.common import importutils
from cinder.openstack.common import log as logging
from cinder.openstack.common import processutils
from cinder import test
from cinder.tests import fake_notifier
from cinder import utils
@ -200,3 +201,19 @@ class ClearVolumeTestCase(test.TestCase):
self.stubs.Set(volume_utils, 'copy_volume', fake_copy_volume)
volume_utils.clear_volume(123, vol_path)
class CopyVolumeTestCase(test.TestCase):
def test_copy_volume_dd_iflag_and_oflag(self):
def fake_utils_execute(*cmd, **kwargs):
if 'if=/dev/zero' in cmd and 'iflag=direct' in cmd:
raise processutils.ProcessExecutionError()
if 'of=/dev/null' in cmd and 'oflag=direct' in cmd:
raise processutils.ProcessExecutionError()
if 'iflag=direct' in cmd and 'oflag=direct' in cmd:
raise exception.InvalidInput(message='iflag/oflag error')
volume_utils.copy_volume('/dev/zero', '/dev/null', 1024,
CONF.volume_dd_blocksize, sync=True,
ionice=None, execute=fake_utils_execute)

17
cinder/volume/utils.py
View File

@ -131,14 +131,15 @@ def _calculate_count(size_in_m, blocksize):
def copy_volume(srcstr, deststr, size_in_m, blocksize, sync=False,
execute=utils.execute, ionice=None):
# Use O_DIRECT to avoid thrashing the system buffer cache
extra_flags = ['iflag=direct', 'oflag=direct']
# Check whether O_DIRECT is supported
try:
execute('dd', 'count=0', 'if=%s' % srcstr, 'of=%s' % deststr,
*extra_flags, run_as_root=True)
except processutils.ProcessExecutionError:
extra_flags = []
extra_flags = []
# Check whether O_DIRECT is supported to iflag and oflag separately
for flag in ['iflag=direct', 'oflag=direct']:
try:
execute('dd', 'count=0', 'if=%s' % srcstr, 'of=%s' % deststr,
flag, run_as_root=True)
extra_flags.append(flag)
except processutils.ProcessExecutionError:
pass
# If the volume is being unprovisioned then
# request the data is persisted before returning,