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[PULL 14/15] qcow2_format.py: dump bitmaps header extension
From: |
Eric Blake |
Subject: |
[PULL 14/15] qcow2_format.py: dump bitmaps header extension |
Date: |
Tue, 9 Jun 2020 15:52:44 -0500 |
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Add class for bitmap extension and dump its fields. Further work is to
dump bitmap directory.
Test new functionality inside 291 iotest.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-Id: <20200606081806.23897-14-vsementsov@virtuozzo.com>
[eblake: fix iotest output]
Signed-off-by: Eric Blake <eblake@redhat.com>
---
tests/qemu-iotests/291 | 4 +++
tests/qemu-iotests/291.out | 33 +++++++++++++++++++++++
tests/qemu-iotests/qcow2_format.py | 42 +++++++++++++++++++++++-------
3 files changed, 70 insertions(+), 9 deletions(-)
diff --git a/tests/qemu-iotests/291 b/tests/qemu-iotests/291
index 3ca83b9cd1f7..e0cffc7cb119 100755
--- a/tests/qemu-iotests/291
+++ b/tests/qemu-iotests/291
@@ -62,6 +62,8 @@ $QEMU_IO -c 'w 1M 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG bitmap --disable -f $IMGFMT "$TEST_IMG" b1
$QEMU_IMG bitmap --enable -f $IMGFMT "$TEST_IMG" b2
$QEMU_IO -c 'w 2M 1M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+echo "Check resulting qcow2 header extensions:"
+$PYTHON qcow2.py "$TEST_IMG" dump-header-exts
echo
echo "=== Bitmap preservation not possible to non-qcow2 ==="
@@ -88,6 +90,8 @@ $QEMU_IMG bitmap --merge tmp -f $IMGFMT "$TEST_IMG" b0
$QEMU_IMG bitmap --remove --image-opts \
driver=$IMGFMT,file.driver=file,file.filename="$TEST_IMG" tmp
$QEMU_IMG info "$TEST_IMG" | _filter_img_info --format-specific
+echo "Check resulting qcow2 header extensions:"
+$PYTHON qcow2.py "$TEST_IMG" dump-header-exts
echo
echo "=== Check bitmap contents ==="
diff --git a/tests/qemu-iotests/291.out b/tests/qemu-iotests/291.out
index 8c62017567e9..ccfcdc5e35ce 100644
--- a/tests/qemu-iotests/291.out
+++ b/tests/qemu-iotests/291.out
@@ -14,6 +14,25 @@ wrote 1048576/1048576 bytes at offset 1048576
1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 1048576/1048576 bytes at offset 2097152
1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Check resulting qcow2 header extensions:
+Header extension:
+magic 0xe2792aca (Backing format)
+length 5
+data 'qcow2'
+
+Header extension:
+magic 0x6803f857 (Feature table)
+length 336
+data <binary>
+
+Header extension:
+magic 0x23852875 (Bitmaps)
+length 24
+nb_bitmaps 2
+reserved32 0
+bitmap_directory_size 0x40
+bitmap_directory_offset 0x510000
+
=== Bitmap preservation not possible to non-qcow2 ===
@@ -65,6 +84,20 @@ Format specific information:
granularity: 65536
refcount bits: 16
corrupt: false
+Check resulting qcow2 header extensions:
+Header extension:
+magic 0x6803f857 (Feature table)
+length 336
+data <binary>
+
+Header extension:
+magic 0x23852875 (Bitmaps)
+length 24
+nb_bitmaps 3
+reserved32 0
+bitmap_directory_size 0x60
+bitmap_directory_offset 0x520000
+
=== Check bitmap contents ===
diff --git a/tests/qemu-iotests/qcow2_format.py
b/tests/qemu-iotests/qcow2_format.py
index 40b5bf467b24..0f65fd161d5b 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -103,6 +103,19 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
print('{:<25} {}'.format(f[2], value_str))
+class Qcow2BitmapExt(Qcow2Struct):
+
+ fields = (
+ ('u32', '{}', 'nb_bitmaps'),
+ ('u32', '{}', 'reserved32'),
+ ('u64', '{:#x}', 'bitmap_directory_size'),
+ ('u64', '{:#x}', 'bitmap_directory_offset')
+ )
+
+
+QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
+
+
class QcowHeaderExtension(Qcow2Struct):
class Magic(Enum):
@@ -110,7 +123,7 @@ class QcowHeaderExtension(Qcow2Struct):
0xe2792aca: 'Backing format',
0x6803f857: 'Feature table',
0x0537be77: 'Crypto header',
- 0x23852875: 'Bitmaps',
+ QCOW2_EXT_MAGIC_BITMAPS: 'Bitmaps',
0x44415441: 'Data file'
}
@@ -130,8 +143,11 @@ class QcowHeaderExtension(Qcow2Struct):
This should be somehow refactored and functionality should be moved to
superclass (to allow creation of any qcow2 struct), but then, fields
of variable length (data here) should be supported in base class
- somehow. So, it's a TODO. We'll see how to properly refactor this when
- we have more qcow2 structures.
+ somehow. Note also, that we probably want to parse different
+ extensions. Should they be subclasses of this class, or how to do it
+ better? Should it be something like QAPI union with discriminator field
+ (magic here). So, it's a TODO. We'll see how to properly refactor this
+ when we have more qcow2 structures.
"""
if fd is None:
assert all(v is not None for v in (magic, length, data))
@@ -148,15 +164,23 @@ class QcowHeaderExtension(Qcow2Struct):
self.data = fd.read(padded)
assert self.data is not None
- def dump(self):
- data = self.data[:self.length]
- if all(c in string.printable.encode('ascii') for c in data):
- data = f"'{ data.decode('ascii') }'"
+ if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
+ self.obj = Qcow2BitmapExt(data=self.data)
else:
- data = '<binary>'
+ self.obj = None
+ def dump(self):
super().dump()
- print(f'{"data":<25} {data}')
+
+ if self.obj is None:
+ data = self.data[:self.length]
+ if all(c in string.printable.encode('ascii') for c in data):
+ data = f"'{ data.decode('ascii') }'"
+ else:
+ data = '<binary>'
+ print(f'{"data":<25} {data}')
+ else:
+ self.obj.dump()
@classmethod
def create(cls, magic, data):
--
2.27.0
- [PULL 04/15] qcow2.py: move qcow2 format classes to separate module, (continued)
- [PULL 04/15] qcow2.py: move qcow2 format classes to separate module, Eric Blake, 2020/06/09
- [PULL 10/15] qcow2_format.py: add field-formatting class, Eric Blake, 2020/06/09
- [PULL 07/15] qcow2_format.py: use modern string formatting, Eric Blake, 2020/06/09
- [PULL 09/15] qcow2_format.py: separate generic functionality of structure classes, Eric Blake, 2020/06/09
- [PULL 02/15] qcow2.py: python style fixes, Eric Blake, 2020/06/09
- [PULL 12/15] qcow2_format: refactor QcowHeaderExtension as a subclass of Qcow2Struct, Eric Blake, 2020/06/09
- [PULL 15/15] iotests: Fix 291 across more file systems, Eric Blake, 2020/06/09
- [PULL 06/15] qcow2_format.py: use tuples instead of lists for fields, Eric Blake, 2020/06/09
- [PULL 08/15] qcow2_format.py: use strings to specify c-type of struct fields, Eric Blake, 2020/06/09
- [PULL 11/15] qcow2_format.py: QcowHeaderExtension: add dump method, Eric Blake, 2020/06/09
- [PULL 14/15] qcow2_format.py: dump bitmaps header extension,
Eric Blake <=
- [PULL 13/15] qcow2: QcowHeaderExtension print names for extension magics, Eric Blake, 2020/06/09
- Re: [PULL 00/15] bitmaps patches for 2020-06-09, Peter Maydell, 2020/06/11