There are two ways to initialize a class derived from Qcow2Struct:
1. Pass a block of binary data to the constructor.
2. Pass the file descriptor to allow reading the file from constructor.
Let's change the Qcow2BitmapExt initialization method from 1 to 2 to
support a scattered reading in the initialization chain.
The implementation comes with the patch that follows.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
tests/qemu-iotests/qcow2_format.py | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/tests/qemu-iotests/qcow2_format.py
b/tests/qemu-iotests/qcow2_format.py
index 2f3681b..9eb6b5b 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -62,8 +62,8 @@ class Qcow2StructMeta(type):
class Qcow2Struct(metaclass=Qcow2StructMeta):
-
- """Qcow2Struct: base class for qcow2 data structures
+ """
+ Qcow2Struct: base class for qcow2 data structures
Successors should define fields class variable, which is: list of tuples,
each of three elements:
@@ -173,7 +173,13 @@ class QcowHeaderExtension(Qcow2Struct):
self.data_str = data_str
if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
- self.obj = Qcow2BitmapExt(data=self.data)
+ assert fd is not None
+ position = fd.tell()
+ # Step back to reread data
+ padded = (self.length + 7) & ~7
+ fd.seek(-padded, 1)
+ self.obj = Qcow2BitmapExt(fd=fd)
+ fd.seek(position)
else:
self.obj = None
--
1.8.3.1
