On 03.07.2020 16:13, Andrey Shinkevich wrote:
Add bitmap table information to the QCOW2 metadata dump.
...
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -171,14 +171,56 @@ 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
+ 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)
As an option, one make the class Qcow2BitmapTableEntry derived from
Qcow2Struct
with the member:
fields = (
('u64', '{:#x}', 'table_entry')
)
and read entry by entry bitmap_table_size times from the disk in a loop.
Andrey
+
def dump(self):
print(f'{"Bitmap name":<25} {self.name}')
super(Qcow2BitmapDirEntry, self).dump()
+ self.bitmap_table.dump()
+
+
+class Qcow2BitmapTableEntry:
+
+ 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):
+ 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
