Read and dump entries from the bitmap directory of QCOW2 image.
It extends the output in the test case #291.
Header extension:
magic 0x23852875 (Bitmaps)
...
Bitmap name bitmap-1
bitmap_table_offset 0xf0000
bitmap_table_size 1
flags 0x2 (['auto'])
type 1
granularity_bits 16
name_size 8
extra_data_size 0
Suggested-by: Kevin Wolf <kw...@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
tests/qemu-iotests/291.out | 45 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/qcow2_format.py | 44 +++++++++++++++++++++++++++++++++++++
2 files changed, 89 insertions(+)
diff --git a/tests/qemu-iotests/291.out b/tests/qemu-iotests/291.out
index 08bfaaa..53a8eeb 100644
--- a/tests/qemu-iotests/291.out
+++ b/tests/qemu-iotests/291.out
@@ -33,6 +33,24 @@ reserved32 0
bitmap_directory_size 0x40
bitmap_directory_offset 0x510000
+Bitmap name b1
+bitmap_table_offset 0x4e0000
+bitmap_table_size 1
+flags 0x0 ([])
+type 1
+granularity_bits 19
+name_size 2
+extra_data_size 0
+
+Bitmap name b2
+bitmap_table_offset 0x500000
+bitmap_table_size 1
+flags 0x2 (['auto'])
+type 1
+granularity_bits 16
+name_size 2
+extra_data_size 0
+
=== Bitmap preservation not possible to non-qcow2 ===
@@ -98,6 +116,33 @@ reserved32 0
bitmap_directory_size 0x60
bitmap_directory_offset 0x520000
+Bitmap name b1
+bitmap_table_offset 0x470000
+bitmap_table_size 1
+flags 0x0 ([])
+type 1
+granularity_bits 19
+name_size 2
+extra_data_size 0
+
+Bitmap name b2
+bitmap_table_offset 0x490000
+bitmap_table_size 1
+flags 0x2 (['auto'])
+type 1
+granularity_bits 16
+name_size 2
+extra_data_size 0
+
+Bitmap name b0
+bitmap_table_offset 0x510000
+bitmap_table_size 1
+flags 0x0 ([])
+type 1
+granularity_bits 16
+name_size 2
+extra_data_size 0
+
=== Check bitmap contents ===
diff --git a/tests/qemu-iotests/qcow2_format.py
b/tests/qemu-iotests/qcow2_format.py
index d8c058d..7c0dc9a 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -132,6 +132,50 @@ class Qcow2BitmapExt(Qcow2Struct):
def __init__(self, fd):
super().__init__(fd=fd)
+ self.read_bitmap_directory(fd)
+
+ def read_bitmap_directory(self, fd):
+ fd.seek(self.bitmap_directory_offset)
+ self.bitmap_directory = \
+ [Qcow2BitmapDirEntry(fd) for _ in range(self.nb_bitmaps)]
+
+ def dump(self):
+ super().dump()
+ for entry in self.bitmap_directory:
+ print()
+ entry.dump()
+
+
+class Qcow2BitmapDirEntry(Qcow2Struct):
+
+ fields = (
+ ('u64', '{:#x}', 'bitmap_table_offset'),
+ ('u32', '{}', 'bitmap_table_size'),
+ ('u32', BitmapFlags, 'flags'),
+ ('u8', '{}', 'type'),
+ ('u8', '{}', 'granularity_bits'),
+ ('u16', '{}', 'name_size'),
+ ('u32', '{}', 'extra_data_size')
+ )
+
+ def __init__(self, fd):
+ super().__init__(fd=fd)
+ # Seek relative to the current position in the file
+ fd.seek(self.extra_data_size, 1)
+ bitmap_name = fd.read(self.name_size)
+ self.name = bitmap_name.decode('ascii')
+ # Move position to the end of the entry in the directory
+ entry_raw_size = self.bitmap_dir_entry_raw_size()
+ padding = ((entry_raw_size + 7) & ~7) - entry_raw_size
+ fd.seek(padding, 1)
+
+ def bitmap_dir_entry_raw_size(self):
+ return struct.calcsize(self.fmt) + self.name_size + \
+ self.extra_data_size
+
+ def dump(self):
+ print(f'{"Bitmap name":<25} {self.name}')
+ super(Qcow2BitmapDirEntry, self).dump()
QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
--
1.8.3.1
