def start_clear_holders_deps():
"""
prepare system for clear holders to be able to scan old devices
"""
# a mdadm scan has to be started in case there is a md device that needs to
# be detected. if the scan fails, it is either because there are no mdadm
# devices on the system, or because there is a mdadm device in a damaged
# state that could not be started. due to the nature of mdadm tools, it is
# difficult to know which is the case. if any errors did occur, then ignore
# them, since no action needs to be taken if there were no mdadm devices on
# the system, and in the case where there is some mdadm metadata on a disk,
# but there was not enough to start the array, the call to wipe_volume on
# all disks and partitions should be sufficient to remove the mdadm
# metadata
mdadm.mdadm_assemble(scan=True, ignore_errors=True)
# scan and activate for logical volumes
lvm.lvm_scan()
lvm.activate_volgroups()
# the bcache module needs to be present to properly detect bcache devs
# on some systems (precise without hwe kernel) it may not be possible to
# lad the bcache module bcause it is not present in the kernel. if this
# happens then there is no need to halt installation, as the bcache devices
# will never appear and will never prevent the disk from being reformatted
util.load_kernel_module('bcache')
if not zfs.zfs_supported():
LOG.warning('zfs filesystem is not supported in this environment')
def test_zfs_supported_returns_false_on_assert_fail(self, m_assert_zfs):
zfs_supported = False
m_assert_zfs.side_effect = RuntimeError('No zfs module')
result = zfs.zfs_supported()
self.assertEqual(zfs_supported, result)
self.assertEqual(1, m_assert_zfs.call_count)
def test_zfs_supported(self, m_assert_zfs):
zfs_supported = True
m_assert_zfs.return_value = zfs_supported
result = zfs.zfs_supported()
self.assertEqual(zfs_supported, result)
self.assertEqual(1, m_assert_zfs.call_count)
def test_zfs_assert_supported_returns_true(self, mock_util, mock_supfs):
"""zfs_assert_supported returns True on supported platforms"""
mock_util.get_platform_arch.return_value = 'amd64'
mock_util.lsb_release.return_value = {'codename': 'bionic'}
mock_util.subp.return_value = ("", "")
mock_supfs.return_value = ['zfs']
mock_util.which.side_effect = iter(['/wark/zpool', '/wark/zfs'])
self.assertNotIn(mock_util.get_platform_arch.return_value,
zfs.ZFS_UNSUPPORTED_ARCHES)
self.assertNotIn(mock_util.lsb_release.return_value['codename'],
zfs.ZFS_UNSUPPORTED_RELEASES)
self.assertTrue(zfs.zfs_supported())
def start_clear_holders_deps():
"""
prepare system for clear holders to be able to scan old devices
"""
# a mdadm scan has to be started in case there is a md device that needs to
# be detected. if the scan fails, it is either because there are no mdadm
# devices on the system, or because there is a mdadm device in a damaged
# state that could not be started. due to the nature of mdadm tools, it is
# difficult to know which is the case. if any errors did occur, then ignore
# them, since no action needs to be taken if there were no mdadm devices on
# the system, and in the case where there is some mdadm metadata on a disk,
# but there was not enough to start the array, the call to wipe_volume on
# all disks and partitions should be sufficient to remove the mdadm
# metadata
mdadm.mdadm_assemble(scan=True, ignore_errors=True)
# collect detail on any assembling arrays
for md in [
md for md in glob.glob('/dev/md*')
if not os.path.isdir(md) and not identify_partition(md)
]:
mdstat = None
if os.path.exists('/proc/mdstat'):
mdstat = util.load_file('/proc/mdstat')
LOG.debug("/proc/mdstat:\n%s", mdstat)
found = [
line for line in mdstat.splitlines()
if os.path.basename(md) in line
]
# in some cases we have a /dev/md0 device node
# but the kernel has already renamed the device /dev/md127
if len(found) == 0:
LOG.debug('Ignoring md device %s, not present in mdstat', md)
continue
# give it a second poke to encourage running
try:
LOG.debug('Activating mdadm array %s', md)
(out, err) = mdadm.mdadm_run(md)
LOG.debug('MDADM run on %s stdout:\n%s\nstderr:\n%s', md, out, err)
except util.ProcessExecutionError:
LOG.debug('Non-fatal error when starting mdadm device %s', md)
# extract details if we can
try:
(out, err) = mdadm.mdadm_query_detail(md,
export=False,
rawoutput=True)
LOG.debug('MDADM detail on %s stdout:\n%s\nstderr:\n%s', md, out,
err)
except util.ProcessExecutionError:
LOG.debug('Non-fatal error when querying mdadm detail on %s', md)
# scan and activate for logical volumes
lvm.lvm_scan()
lvm.activate_volgroups()
# the bcache module needs to be present to properly detect bcache devs
# on some systems (precise without hwe kernel) it may not be possible to
# lad the bcache module bcause it is not present in the kernel. if this
# happens then there is no need to halt installation, as the bcache devices
# will never appear and will never prevent the disk from being reformatted
util.load_kernel_module('bcache')
if not zfs.zfs_supported():
LOG.warning('zfs filesystem is not supported in this environment')
def wipe_superblock(device):
"""
Wrapper for block.wipe_volume compatible with shutdown function interface
"""
blockdev = block.sysfs_to_devpath(device)
# when operating on a disk that used to have a dos part table with an
# extended partition, attempting to wipe the extended partition will fail
try:
if not block.is_online(blockdev):
LOG.debug("Device is not online (size=0), so skipping:"
" '%s'", blockdev)
return
if block.is_extended_partition(blockdev):
LOG.info(
"extended partitions do not need wiping, so skipping:"
" '%s'", blockdev)
return
except OSError as e:
if util.is_file_not_found_exc(e):
LOG.debug('Device to wipe disappeared: %s', e)
LOG.debug('/proc/partitions says: %s',
util.load_file('/proc/partitions'))
(parent, partnum) = block.get_blockdev_for_partition(blockdev)
out, _e = util.subp(['sfdisk', '-d', parent],
capture=True,
combine_capture=True)
LOG.debug('Disk partition info:\n%s', out)
return
else:
raise e
# gather any partitions
partitions = block.get_sysfs_partitions(device)
# release zfs member by exporting the pool
if zfs.zfs_supported() and block.is_zfs_member(blockdev):
poolname = zfs.device_to_poolname(blockdev)
# only export pools that have been imported
if poolname in zfs.zpool_list():
try:
zfs.zpool_export(poolname)
except util.ProcessExecutionError as e:
LOG.warning('Failed to export zpool "%s": %s', poolname, e)
if is_swap_device(blockdev):
shutdown_swap(blockdev)
# some volumes will be claimed by the bcache layer but do not surface
# an actual /dev/bcacheN device which owns the parts (backing, cache)
# The result is that some volumes cannot be wiped while bcache claims
# the device. Resolve this by stopping bcache layer on those volumes
# if present.
for bcache_path in ['bcache', 'bcache/set']:
stop_path = os.path.join(device, bcache_path)
if os.path.exists(stop_path):
LOG.debug('Attempting to release bcache layer from device: %s:%s',
device, stop_path)
if stop_path.endswith('set'):
rp = os.path.realpath(stop_path)
bcache.stop_cacheset(rp)
else:
bcache._stop_device(stop_path)
_wipe_superblock(blockdev)
# if we had partitions, make sure they've been removed
if partitions:
LOG.debug('%s had partitions, issuing partition reread', device)
retries = [.5, .5, 1, 2, 5, 7]
for attempt, wait in enumerate(retries):
try:
# only rereadpt on wiped device
block.rescan_block_devices(devices=[blockdev])
# may raise IOError, OSError due to wiped partition table
curparts = block.get_sysfs_partitions(device)
if len(curparts) == 0:
return
except (IOError, OSError):
if attempt + 1 >= len(retries):
raise
LOG.debug(
"%s partitions still present, rereading pt"
" (%s/%s). sleeping %ss before retry", device, attempt + 1,
len(retries), wait)
time.sleep(wait)
# multipath partitions are separate block devices (disks)
if multipath.is_mpath_partition(blockdev):
multipath.remove_partition(blockdev)
# multipath devices must be hidden to utilize a single member (path)
elif multipath.is_mpath_device(blockdev):
mp_id = multipath.find_mpath_id(blockdev)
if mp_id:
multipath.remove_map(mp_id)
else:
raise RuntimeError('Failed to find multipath id for %s' % blockdev)
def test_supported_arch(self):
self.assertTrue(zfs.zfs_supported())
