def test_base_allocation_many_extents(nbd_server, user_file):
# Tested only with raw since qcow2 minimal extent is cluster size (64K),
# and writing 1000 extents (62.5 MiB) will be too slow in the CI.
# Extents must be multiple of file system block size.
extent_length = os.statvfs(user_file.path).f_bsize
# Use number which is not a multiple of our buffer capacity (1024 extents)
# to ensure we read partial buffers correctly.
extents_count = 2000
size = extents_count * extent_length
create_image(user_file.path, "raw", size)
nbd_server.image = user_file.path
nbd_server.fmt = "raw"
nbd_server.start()
with nbd.open(nbd_server.url) as c:
# Write data to all even extents.
data = b"x" * extent_length
for i in range(0, size, extent_length * 2):
c.write(i, data)
extents = list(nbdutil.extents(c))
assert len(extents) == extents_count
for i, ext in enumerate(extents):
assert ext.length == extent_length
assert ext.zero == bool(i % 2)
def test_base_allocation_some_data(nbd_server, user_file, fmt, zero_flags):
size = 1024**3
create_image(user_file.path, fmt, size)
nbd_server.image = user_file.path
nbd_server.fmt = fmt
nbd_server.start()
# Use qcow2 cluster size to avoid inconsistent results on CentOS and
# Fedora.
data_length = 64 * 1024
zero_length = size // 2 - data_length
with nbd.open(nbd_server.url) as c:
# Create 4 extents: data, zero, data, zero.
c.write(0, b"x" * data_length)
c.write(size // 2, b"x" * data_length)
extents = list(nbdutil.extents(c))
assert extents == [
nbd.Extent(length=data_length, flags=0),
nbd.Extent(length=zero_length, flags=zero_flags),
nbd.Extent(length=data_length, flags=0),
nbd.Extent(length=zero_length, flags=zero_flags),
]
def test_some_data_offset_unaligned(dirty):
c = SomeData(1, dirty)
extents = list(
nbdutil.extents(c, offset=c.extent_size // 2 * 3, dirty=dirty))
assert extents == [
nbd.Extent(c.extent_size // 2, 1),
nbd.Extent(c.extent_size, 0),
]
def test_some_data_offset(dirty):
c = SomeData(1, dirty)
extents = list(nbdutil.extents(c, offset=0, dirty=dirty))
assert extents == [
nbd.Extent(c.extent_size, 0),
nbd.Extent(c.extent_size, 1),
nbd.Extent(c.extent_size, 0),
]
def verify_full_backup(sock, export_name):
with nbd.Client(sock, export_name) as c:
log.debug("Backing up data with nbd client")
offset = 0
for ext in nbdutil.extents(c):
if not ext.zero:
expected = b"%d\n" % offset
data = c.read(offset, len(expected))
assert data == expected
offset += ext.length
def test_base_allocation_some_data_unaligned(nbd_server, user_file, fmt,
zero_flags):
size = 1024**2
create_image(user_file.path, fmt, size)
nbd_server.image = user_file.path
nbd_server.fmt = fmt
nbd_server.start()
data_length = 64 * 1024
data_offset = 2 * data_length
with nbd.open(nbd_server.url) as c:
# Create 3 extents: zero, data, zero.
c.write(data_offset, b"x" * data_length)
# Unaligned part from first extent and last extent.
extents = list(nbdutil.extents(c, data_offset - 1, data_length + 2))
assert extents == [
nbd.Extent(length=1, flags=zero_flags),
nbd.Extent(length=data_length, flags=0),
nbd.Extent(length=1, flags=zero_flags),
]
# Unaligned part from second extent.
extents = list(nbdutil.extents(c, data_offset + 1, data_length - 2))
assert extents == [
nbd.Extent(length=data_length - 2, flags=0),
]
# Unaligned part from second and last extents.
extents = list(nbdutil.extents(c, data_offset + 1, data_length))
assert extents == [
nbd.Extent(length=data_length - 1, flags=0),
nbd.Extent(length=1, flags=zero_flags),
]
def copy_dirty(nbd_url, backup_disk):
log.info("Backing up dirty extents from %s to %s", nbd_url, backup_disk)
backup_url = urlparse(nbd_url)
with nbd.open(backup_url, dirty=True) as src_client, \
qemu_nbd.open(backup_disk, "qcow2") as dst_client:
buf = bytearray(4 * 1024**2)
offset = 0
for ext in nbdutil.extents(src_client, dirty=True):
if ext.dirty:
todo = ext.length
while todo:
step = min(todo, len(buf))
view = memoryview(buf)[:step]
src_client.readinto(offset, view)
dst_client.write(offset, view)
offset += step
todo -= step
else:
offset += ext.length
def test_last_extent_exceeds_length(dirty, offset, length):
c = ExcceedsLength(1, dirty)
extents = list(
nbdutil.extents(c, offset=offset, length=length, dirty=dirty))
assert extents == [nbd.Extent(length, 1)]
def test_short_reply_offset(dirty, offset):
c = ShortReply(1, dirty)
extents = list(nbdutil.extents(c, offset=offset, dirty=dirty))
assert extents == [nbd.Extent(c.export_size - offset, 1)]
def test_short_reply_offset_length(dirty, offset, length):
c = ShortReply(1, dirty)
extents = list(
nbdutil.extents(c, offset=offset, length=length, dirty=dirty))
assert extents == [nbd.Extent(length, 1)]
def test_short_reply(dirty):
c = ShortReply(1, dirty)
extents = list(nbdutil.extents(c, dirty=dirty))
assert extents == [nbd.Extent(c.export_size, 1)]
def test_single_extent_offset_length(dirty, offset, length):
c = SingleExtent(1, dirty)
extents = list(
nbdutil.extents(c, offset=offset, length=length, dirty=dirty))
assert extents == [nbd.Extent(length, 1)]
def test_single_extent_offset(dirty, offset):
c = SingleExtent(1, dirty)
extents = list(nbdutil.extents(c, offset=offset, dirty=dirty))
assert extents == [nbd.Extent(c.export_size - offset, 1)]
def test_single_extent(dirty):
c = SingleExtent(1, dirty)
extents = list(nbdutil.extents(c, dirty=dirty))
assert extents == [nbd.Extent(c.export_size, 1)]
def test_complete_reply(dirty):
c = CompleteReply(1, dirty)
extents = list(nbdutil.extents(c, dirty=dirty))
assert extents == [nbd.Extent(c.export_size, 1)]