def test_is_swap_device_read_offsets(self, mock_util, mock_resource):
"""swap.is_swap_device() checks offsets based on system pagesize"""
path = '/mydev/dummydisk'
# 4k and 64k page size
for pagesize in [4096, 65536]:
magic_offset = pagesize - 10
mock_resource.getpagesize.return_value = pagesize
swap.is_swap_device(path)
mock_util.load_file.assert_called_with(path,
read_len=10,
offset=magic_offset,
decode=False)
def test_identify_swap_true(self, mock_util, mock_resource):
"""swap.is_swap_device() returns true on swap magic strings"""
path = '/mydev/dummydisk'
for magic in [b'SWAPSPACE2', b'SWAP-SPACE']:
mock_util.load_file.return_value = magic
is_swap = swap.is_swap_device(path)
self.assertTrue(is_swap)
def test_identify_swap_false(self, mock_getpagesize):
"""swap.is_swap_device() returns false on non swap content"""
pagesize = mock_getpagesize()
path = self.tmp_path("notswap1")
# this is just arbitrary content that is not swap content.
blob = b'\x00\x00c\x05\x00\x00\x11\x19'
util.write_file(path, int(pagesize * 2 / len(blob)) * blob, omode="wb")
self.assertFalse(swap.is_swap_device(path))
def test_is_swap_device_read_offsets(self, mock_getpagesize):
"""swap.is_swap_device() correctly identifies swap content."""
tmpd = self.tmp_dir()
for num, (pagesize, content) in enumerate(self._valid_swap_contents()):
path = self.tmp_path("swap-file-%02d" % num, tmpd)
util.write_file(path, content, omode="wb")
mock_getpagesize.return_value = pagesize
self.assertTrue(swap.is_swap_device(path))
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_identify_swap_false(self, mock_util, mock_resource):
"""swap.is_swap_device() returns false on non swap magic"""
mock_util.load_file.return_value = (
b'\x00\x00c\x05\x00\x00\x11\x00\x19\x00')
is_swap = swap.is_swap_device('ignored')
self.assertFalse(is_swap)
def test_identify_zeros_are_swap(self, mock_getpagesize):
"""swap.is_swap_device() returns false on all zeros"""
pagesize = mock_getpagesize()
path = self.tmp_path("notswap0")
util.write_file(path, pagesize * 2 * b'\0', omode="wb")
self.assertFalse(swap.is_swap_device(path))
def test_identify_swap_false_if_tiny(self, mock_getpagesize):
"""small files do not trip up is_swap_device()."""
path = self.tmp_path("tiny")
util.write_file(path, b'tinystuff', omode='wb')
self.assertFalse(swap.is_swap_device(path))
