def test_backing_chain(tmpdir):
size = 128 * 1024
base = str(tmpdir.join("base.raw"))
top = str(tmpdir.join("top.qcow2"))
base_data = b"data from base".ljust(32, b"\0")
# Add base image with some data.
qemu_img.create(base, "raw", size=size)
with qemu_nbd.open(base, "raw") as c:
c.write(0, base_data)
c.flush()
# Add empty overlay.
qemu_img.create(top, "qcow2", backing_file=base, backing_format="raw")
top_addr = nbd.UnixAddress(str(tmpdir.join("sock")))
# By default, we see data from base.
with qemu_nbd.run(top, "qcow2", top_addr), \
nbd.Client(top_addr) as c:
assert c.read(0, 32) == base_data
# With backing chain disabled, we see data only from top.
with qemu_nbd.run(top, "qcow2", top_addr, backing_chain=False), \
nbd.Client(top_addr) as c:
assert c.read(0, 32) == b"\0" * 32
def test_options(tmpdir, fmt, options):
size = 4 * 1024**2
chunk_size = 128 * 1024
src = str(tmpdir.join("src." + fmt))
qemu_img.create(src, fmt, size=size)
with qemu_nbd.open(src, fmt) as c:
for offset in range(0, size, chunk_size):
c.write(offset, struct.pack(">Q", offset))
c.flush()
dst = str(tmpdir.join("dst." + fmt))
qemu_img.create(dst, fmt, size=size)
src_addr = nbd.UnixAddress(str(tmpdir.join("src.sock")))
dst_addr = nbd.UnixAddress(str(tmpdir.join("dst.sock")))
with qemu_nbd.run(
src, fmt, src_addr,
read_only=True,
**options), \
qemu_nbd.run(
dst, fmt, dst_addr,
**options), \
nbd.Client(src_addr) as src_client, \
nbd.Client(dst_addr) as dst_client:
nbdutil.copy(src_client, dst_client)
qemu_img.compare(src, dst)
def test_copy_nbd_to_nbd(tmpdir, src_fmt, dst_fmt, zero, hole):
# Default cluser size with qcow2 format.
cluster_size = 64 * 1024
extents = [
("data", cluster_size),
("zero", cluster_size),
("data", cluster_size),
("hole", cluster_size + io.MAX_ZERO_SIZE),
("data", cluster_size + io.BUFFER_SIZE),
("hole", cluster_size),
("data", cluster_size),
]
size = sum(length for _, length in extents)
src = str(tmpdir.join("src." + src_fmt))
qemu_img.create(src, src_fmt, size=size)
populate_image(src, src_fmt, extents)
src_sock = UnixAddress(tmpdir.join("src.sock"))
src_url = urlparse(src_sock.url())
dst = str(tmpdir.join("dst." + dst_fmt))
qemu_img.create(dst, dst_fmt, size=size)
dst_sock = UnixAddress(tmpdir.join("dst.sock"))
dst_url = urlparse(dst_sock.url())
# Note: We need extra worker for reading extents for source.
max_workers = 2
with qemu_nbd.run(
src, src_fmt, src_sock,
read_only=True,
shared=max_workers + 1), \
qemu_nbd.run(
dst, dst_fmt, dst_sock,
shared=max_workers), \
nbd.open(src_url, "r") as src_backend, \
nbd.open(dst_url, "r+", sparse=True) as dst_backend:
# Because we copy to new image, we can always use zero=False, but we
# test both to verify that the result is the same.
io.copy(src_backend,
dst_backend,
max_workers=max_workers,
zero=zero,
hole=hole)
# Compare image content - must match.
qemu_img.compare(src, dst)
# Allocation can be compared only with qcow2 images when we write zeroes to
# zero extents and skip holes.
if src_fmt == "qcow2" and dst_fmt == "qcow2" and zero and not hole:
qemu_img.compare(src, dst, strict=True)
def test_shared(tmpdir, fmt):
size = 1024**2
chunk_size = size // 2
src = str(tmpdir.join("src." + fmt))
qemu_img.create(src, fmt, size=size)
with qemu_nbd.open(src, fmt) as c:
c.write(0, b"a" * chunk_size)
c.write(0, b"b" * chunk_size)
c.flush()
dst = str(tmpdir.join("dst." + fmt))
qemu_img.create(dst, fmt, size=size)
src_addr = nbd.UnixAddress(str(tmpdir.join("src.sock")))
dst_addr = nbd.UnixAddress(str(tmpdir.join("dst.sock")))
# Start 2 qemu-nbd servers, each with 2 clients that can read and write in
# parallel for higher throughput.
with qemu_nbd.run(src, fmt, src_addr, read_only=True, shared=2), \
qemu_nbd.run(dst, fmt, dst_addr, shared=2), \
nbd.Client(src_addr) as src_client1, \
nbd.Client(src_addr) as src_client2, \
nbd.Client(dst_addr) as dst_client1, \
nbd.Client(dst_addr) as dst_client2:
# Copy first half of the image with src_client1 and dst_client2 and
# second half with src_client2 and dst_client2. In a real application
# we would have more clients, running in multiple threads.
chunk1 = src_client1.read(0, chunk_size)
dst_client1.write(0, chunk1)
chunk2 = src_client2.read(chunk_size, chunk_size)
dst_client2.write(chunk_size, chunk2)
dst_client1.flush()
dst_client2.flush()
qemu_img.compare(src, dst)
def test_run_tcp(tmpfile):
with io.open(tmpfile, "r+b") as f:
f.truncate(1024**2)
addr = nbd.TCPAddress("localhost", testutil.random_tcp_port())
with qemu_nbd.run(tmpfile, "raw", addr):
# The helper already waited for the NBD socket, not wait needed.
assert sockutil.wait_for_socket(addr, 0.0)
# The socket must be closed, no wait needed.
assert not sockutil.wait_for_socket(addr, 0.0)
def test_open_tcp(tmpdir, url_template, host, export):
image = str(tmpdir.join("image"))
with open(image, "wb") as f:
f.truncate(1024**3)
sock = nbd.TCPAddress(host, testutil.random_tcp_port())
url = url_template.format(port=sock.port)
log.debug("Trying url=%r export=%r", url, export)
with qemu_nbd.run(image, "raw", sock, export_name=export):
with nbd.open(urlparse(url)) as c:
assert c.export_size == 1024**3
def test_open_unix(tmpdir, url, export):
image = str(tmpdir.join("image"))
with open(image, "wb") as f:
f.truncate(1024**3)
sock = nbd.UnixAddress(tmpdir.join("sock"))
url = url.replace("/path", sock)
log.debug("Trying url=%r export=%r", url, export)
with qemu_nbd.run(image, "raw", sock, export_name=export):
with nbd.open(urlparse(url)) as c:
assert c.export_size == 1024**3
def test_qcow2_write_read(tmpdir):
image = str(tmpdir.join("image"))
sock = nbd.UnixAddress(tmpdir.join("sock"))
offset = 1024**2
data = b"can read and write qcow2"
create_image(image, "qcow2", 1024**3)
with qemu_nbd.run(image, "qcow2", sock):
with nbd.Client(sock) as c:
c.write(offset, data)
c.flush()
with nbd.Client(sock) as c:
assert c.read(offset, len(data)) == data
def test_raw_read(tmpdir):
image = str(tmpdir.join("image"))
sock = nbd.UnixAddress(tmpdir.join("sock"))
offset = 1024**2
data = b"can read from raw"
with open(image, "wb") as f:
f.truncate(1024**3)
f.seek(offset)
f.write(data)
with qemu_nbd.run(image, "raw", sock):
with nbd.Client(sock) as c:
assert c.read(offset, len(data)) == data
def test_run_unix(tmpdir):
image = str(tmpdir.join("image"))
sock = str(tmpdir.join("sock"))
with io.open(image, "wb") as f:
f.truncate(1024**2)
addr = nbd.UnixAddress(sock)
with qemu_nbd.run(image, "raw", addr):
# The helper already waited for the NBD socket, not wait needed.
assert sockutil.wait_for_socket(addr, 0.0)
# The socket must be closed, no wait needed.
assert not sockutil.wait_for_socket(addr, 0.0)
def test_raw_write(tmpdir):
image = str(tmpdir.join("image"))
with open(image, "wb") as f:
f.truncate(1024**3)
sock = nbd.UnixAddress(tmpdir.join("sock"))
offset = 1024**2
data = b"can write to raw"
with qemu_nbd.run(image, "raw", sock):
with nbd.Client(sock) as c:
c.write(offset, data)
c.flush()
with open(image, "rb") as f:
f.seek(offset)
assert f.read(len(data)) == data
def test_handshake(tmpdir, export, fmt):
image = str(tmpdir.join("image"))
create_image(image, fmt, 1024**3)
sock = nbd.UnixAddress(tmpdir.join("sock"))
with qemu_nbd.run(image, fmt, sock, export_name=export):
if export:
c = nbd.Client(sock, export)
else:
c = nbd.Client(sock)
with c:
# TODO: test transmission_flags?
assert c.export_size == 1024**3
assert c.minimum_block_size == 1
assert c.preferred_block_size == 4096
assert c.maximum_block_size == 32 * 1024**2
assert c.base_allocation
def test_handshake(tmpdir, export, fmt):
image = str(tmpdir.join("image"))
create_image(image, fmt, 1024**3)
sock = nbd.UnixAddress(tmpdir.join("sock"))
with qemu_nbd.run(image, fmt, sock, export_name=export):
if export:
c = nbd.Client(sock, export)
else:
c = nbd.Client(sock)
with c:
# TODO: test transmission_flags?
assert c.export_size == 1024**3
assert c.minimum_block_size == 1
assert c.preferred_block_size == 4096
assert c.maximum_block_size == 32 * 1024**2
# Both available in in current qemu-nbd (>= 5.2.0).
assert c.has_base_allocation
assert c.has_allocation_depth == (fmt != "raw")
def test_zero_min_block_size(tmpdir, fmt):
offset = 1024**2
image = str(tmpdir.join("image"))
sock = nbd.UnixAddress(tmpdir.join("sock"))
create_image(image, fmt, 1024**3)
with qemu_nbd.run(image, fmt, sock):
# Fill range with data
with nbd.Client(sock) as c:
size = c.minimum_block_size
c.write(offset, b"x" * size)
c.flush()
# Zero range using minimum block size
with nbd.Client(sock) as c:
c.zero(offset, size)
c.flush()
with nbd.Client(sock) as c:
assert c.read(offset, size) == b"\0" * size
def test_zero(tmpdir, fmt):
size = 2 * 1024**2
offset = 1024**2
image = str(tmpdir.join("image"))
sock = nbd.UnixAddress(tmpdir.join("sock"))
create_image(image, fmt, size)
with qemu_nbd.run(image, fmt, sock):
# Fill image with data
with nbd.Client(sock) as c:
c.write(0, b"x" * size)
c.flush()
# Zero a range
with nbd.Client(sock) as c:
c.zero(offset, 4096)
c.flush()
with nbd.Client(sock) as c:
assert c.read(offset, 4096) == b"\0" * 4096
