@@ -4,6 +4,7 @@ import sys
import struct
import string
+
class QcowHeaderExtension:
def __init__(self, magic, length, data):
@@ -11,14 +12,15 @@ class QcowHeaderExtension:
padding = 8 - (length % 8)
data += b"\0" * padding
- self.magic = magic
+ self.magic = magic
self.length = length
- self.data = data
+ self.data = data
@classmethod
def create(cls, magic, data):
return QcowHeaderExtension(magic, len(data), data)
+
class QcowHeader:
uint32_t = 'I'
@@ -26,27 +28,27 @@ class QcowHeader:
fields = [
# Version 2 header fields
- [ uint32_t, '%#x', 'magic' ],
- [ uint32_t, '%d', 'version' ],
- [ uint64_t, '%#x', 'backing_file_offset' ],
- [ uint32_t, '%#x', 'backing_file_size' ],
- [ uint32_t, '%d', 'cluster_bits' ],
- [ uint64_t, '%d', 'size' ],
- [ uint32_t, '%d', 'crypt_method' ],
- [ uint32_t, '%d', 'l1_size' ],
- [ uint64_t, '%#x', 'l1_table_offset' ],
- [ uint64_t, '%#x', 'refcount_table_offset' ],
- [ uint32_t, '%d', 'refcount_table_clusters' ],
- [ uint32_t, '%d', 'nb_snapshots' ],
- [ uint64_t, '%#x', 'snapshot_offset' ],
+ [uint32_t, '%#x', 'magic'],
+ [uint32_t, '%d', 'version'],
+ [uint64_t, '%#x', 'backing_file_offset'],
+ [uint32_t, '%#x', 'backing_file_size'],
+ [uint32_t, '%d', 'cluster_bits'],
+ [uint64_t, '%d', 'size'],
+ [uint32_t, '%d', 'crypt_method'],
+ [uint32_t, '%d', 'l1_size'],
+ [uint64_t, '%#x', 'l1_table_offset'],
+ [uint64_t, '%#x', 'refcount_table_offset'],
+ [uint32_t, '%d', 'refcount_table_clusters'],
+ [uint32_t, '%d', 'nb_snapshots'],
+ [uint64_t, '%#x', 'snapshot_offset'],
# Version 3 header fields
- [ uint64_t, 'mask', 'incompatible_features' ],
- [ uint64_t, 'mask', 'compatible_features' ],
- [ uint64_t, 'mask', 'autoclear_features' ],
- [ uint32_t, '%d', 'refcount_order' ],
- [ uint32_t, '%d', 'header_length' ],
- ];
+ [uint64_t, 'mask', 'incompatible_features'],
+ [uint64_t, 'mask', 'compatible_features'],
+ [uint64_t, 'mask', 'autoclear_features'],
+ [uint32_t, '%d', 'refcount_order'],
+ [uint32_t, '%d', 'header_length'],
+ ]
fmt = '>' + ''.join(field[0] for field in fields)
@@ -59,7 +61,7 @@ class QcowHeader:
header = struct.unpack(QcowHeader.fmt, buf)
self.__dict__ = dict((field[2], header[i])
- for i, field in enumerate(QcowHeader.fields))
+ for i, field in enumerate(QcowHeader.fields))
self.set_defaults()
self.cluster_size = 1 << self.cluster_bits
@@ -96,7 +98,8 @@ class QcowHeader:
else:
padded = (length + 7) & ~7
data = fd.read(padded)
- self.extensions.append(QcowHeaderExtension(magic, length, data))
+ self.extensions.append(QcowHeaderExtension(magic, length,
+ data))
def update_extensions(self, fd):
@@ -108,14 +111,13 @@ class QcowHeader:
fd.write(buf)
fd.write(ex.data)
- if self.backing_file != None:
+ if self.backing_file is not None:
self.backing_file_offset = fd.tell()
fd.write(self.backing_file)
if fd.tell() > self.cluster_size:
raise Exception("I think I just broke the image...")
-
def update(self, fd):
header_bytes = self.header_length
@@ -163,19 +165,21 @@ def cmd_dump_header(fd):
h.dump()
h.dump_extensions()
+
def cmd_dump_header_exts(fd):
h = QcowHeader(fd)
h.dump_extensions()
+
def cmd_set_header(fd, name, value):
try:
value = int(value, 0)
- except:
+ except ValueError:
print("'%s' is not a valid number" % value)
sys.exit(1)
fields = (field[2] for field in QcowHeader.fields)
- if not name in fields:
+ if name not in fields:
print("'%s' is not a known header field" % name)
sys.exit(1)
@@ -183,25 +187,29 @@ def cmd_set_header(fd, name, value):
h.__dict__[name] = value
h.update(fd)
+
def cmd_add_header_ext(fd, magic, data):
try:
magic = int(magic, 0)
- except:
+ except ValueError:
print("'%s' is not a valid magic number" % magic)
sys.exit(1)
h = QcowHeader(fd)
- h.extensions.append(QcowHeaderExtension.create(magic, data.encode('ascii')))
+ h.extensions.append(QcowHeaderExtension.create(magic,
+ data.encode('ascii')))
h.update(fd)
+
def cmd_add_header_ext_stdio(fd, magic):
data = sys.stdin.read()
cmd_add_header_ext(fd, magic, data)
+
def cmd_del_header_ext(fd, magic):
try:
magic = int(magic, 0)
- except:
+ except ValueError:
print("'%s' is not a valid magic number" % magic)
sys.exit(1)
@@ -219,12 +227,13 @@ def cmd_del_header_ext(fd, magic):
h.update(fd)
+
def cmd_set_feature_bit(fd, group, bit):
try:
bit = int(bit, 0)
if bit < 0 or bit >= 64:
raise ValueError
- except:
+ except ValueError:
print("'%s' is not a valid bit number in range [0, 64)" % bit)
sys.exit(1)
@@ -236,21 +245,27 @@ def cmd_set_feature_bit(fd, group, bit):
elif group == 'autoclear':
h.autoclear_features |= 1 << bit
else:
- print("'%s' is not a valid group, try 'incompatible', 'compatible', or 'autoclear'" % group)
+ print("'%s' is not a valid group, try "
+ "'incompatible', 'compatible', or 'autoclear'" % group)
sys.exit(1)
h.update(fd)
+
cmds = [
- [ 'dump-header', cmd_dump_header, 0, 'Dump image header and header extensions' ],
- [ 'dump-header-exts', cmd_dump_header_exts, 0, 'Dump image header extensions' ],
- [ 'set-header', cmd_set_header, 2, 'Set a field in the header'],
- [ 'add-header-ext', cmd_add_header_ext, 2, 'Add a header extension' ],
- [ 'add-header-ext-stdio', cmd_add_header_ext_stdio, 1, 'Add a header extension, data from stdin' ],
- [ 'del-header-ext', cmd_del_header_ext, 1, 'Delete a header extension' ],
- [ 'set-feature-bit', cmd_set_feature_bit, 2, 'Set a feature bit'],
+ ['dump-header', cmd_dump_header, 0,
+ 'Dump image header and header extensions'],
+ ['dump-header-exts', cmd_dump_header_exts, 0,
+ 'Dump image header extensions'],
+ ['set-header', cmd_set_header, 2, 'Set a field in the header'],
+ ['add-header-ext', cmd_add_header_ext, 2, 'Add a header extension'],
+ ['add-header-ext-stdio', cmd_add_header_ext_stdio, 1,
+ 'Add a header extension, data from stdin'],
+ ['del-header-ext', cmd_del_header_ext, 1, 'Delete a header extension'],
+ ['set-feature-bit', cmd_set_feature_bit, 2, 'Set a feature bit'],
]
+
def main(filename, cmd, args):
fd = open(filename, "r+b")
try:
@@ -267,6 +282,7 @@ def main(filename, cmd, args):
finally:
fd.close()
+
def usage():
print("Usage: %s <file> <cmd> [<arg>, ...]" % sys.argv[0])
print("")
@@ -274,6 +290,7 @@ def usage():
for name, handler, num_args, desc in cmds:
print(" %-20s - %s" % (name, desc))
+
if __name__ == '__main__':
if len(sys.argv) < 3:
usage()
Fix flake8 complaints. Leave the only chunk of lines over 79 characters: initialization of cmds variable. Leave it for another day, when it should be refactored to utilize argparse instead of hand-written parsing. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- tests/qemu-iotests/qcow2.py | 95 ++++++++++++++++++++++--------------- 1 file changed, 56 insertions(+), 39 deletions(-)