14.07.2020 00:36, Andrey Shinkevich wrote:
> Add bitmap table information to the QCOW2 metadata dump.
>
> Bitmap name bitmap-1
> ...
> Bitmap table type offset size
> 0 serialized 4718592 65536
> 1 serialized 4294967296 65536
> 2 serialized 5348033147437056 65536
> 3 serialized 13792273858822144 65536
> 4 serialized 4718592 65536
> 5 serialized 4294967296 65536
> 6 serialized 4503608217305088 65536
> 7 serialized 14073748835532800 65536
>
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
> tests/qemu-iotests/qcow2_format.py | 42 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
> index d9c8513..2c78d46 100644
> --- a/tests/qemu-iotests/qcow2_format.py
> +++ b/tests/qemu-iotests/qcow2_format.py
> @@ -175,14 +175,56 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
> entry_raw_size = self.bitmap_dir_entry_raw_size()
> padding = ((entry_raw_size + 7) & ~7) - entry_raw_size
> fd.seek(padding, 1)
> + position = fd.tell()
> + self.read_bitmap_table(fd)
> + fd.seek(position)
>
> def bitmap_dir_entry_raw_size(self):
> return struct.calcsize(self.fmt) + self.name_size + \
> self.extra_data_size
>
> + def read_bitmap_table(self, fd):
> + fd.seek(self.bitmap_table_offset)
> + table_size = self.bitmap_table_size * 8 * 8
s/* 8 * 8/* 8/ ?
> + table = [e[0] for e in struct.iter_unpack('>Q', fd.read(table_size))]
> + self.bitmap_table = Qcow2BitmapTable(raw_table=table,
> + cluster_size=self.cluster_size)
Strange to read an unpack it here, when we have separate classes. It's obviously should be work of class: to read and parse its object data from file.
> +
> def dump(self):
> print(f'{"Bitmap name":<25} {self.name}')
> super(Qcow2BitmapDirEntry, self).dump()
> + self.bitmap_table.dump()
> +
> +
> +class Qcow2BitmapTableEntry:
Why not to derive it from Qcow2Struct? It will have only one field, but it will work, and we don't need to open-code loading in .read_bitmap_table of another class
> +
> + BME_TABLE_ENTRY_OFFSET_MASK = 0x00fffffffffffe00
> + BME_TABLE_ENTRY_FLAG_ALL_ONES = 1
> +
> + def __init__(self, entry):
> + self.offset = entry & self.BME_TABLE_ENTRY_OFFSET_MASK
> + if self.offset:
> + self.type = 'serialized'
> + elif entry & self.BME_TABLE_ENTRY_FLAG_ALL_ONES:
> + self.type = 'all-ones'
> + else:
> + self.type = 'all-zeroes'
> +
> +
> +class Qcow2BitmapTable:
> +
> + def __init__(self, raw_table, cluster_size):
As well, probably no sense in deriving from Qcow2Struct, but for consistency, passing fd to __init__, and read all nested things here (list of Qcow2BitmapTableEntry) seems reasonable
> + self.entries = []
> + self.cluster_size = cluster_size
> + for entry in raw_table:
> + self.entries.append(Qcow2BitmapTableEntry(entry))
> +
> + def dump(self):
> + size = self.cluster_size
> + bitmap_table = enumerate(self.entries)
> + print(f'{"Bitmap table":<14} {"type":<15} {"offset":<24} {"size"}')
> + for i, entry in bitmap_table:
> + print(f'{i:<14} {entry.type:<15} {entry.offset:<24} {size}')
>
>
> QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
>
--
Best regards,
Vladimir