From e3f5aad7be0733357875dd45af6e5c59195e590a Mon Sep 17 00:00:00 2001
From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Date: Thu, 6 Aug 2020 22:35:52 +0300
Subject: [PATCH] qcow2_format.py: pass cluster size to substructures

The cluster size of an image is the QcowHeader class member and may be
obtained by dependent extension structures such as Qcow2BitmapExt for
further bitmap table details print.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1596742557-320265-7-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/qcow2_format.py | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 05a8aa98f7..ca0d3501e0 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -129,19 +129,21 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
-    def __init__(self, fd):
+    def __init__(self, fd, cluster_size):
         super().__init__(fd=fd)
         tail = struct.calcsize(self.fmt) % 8
         if tail:
             fd.seek(8 - tail, 1)
         position = fd.tell()
+        self.cluster_size = cluster_size
         self.read_bitmap_directory(fd)
         fd.seek(position)
 
     def read_bitmap_directory(self, fd):
         fd.seek(self.bitmap_directory_offset)
         self.bitmap_directory = \
-            [Qcow2BitmapDirEntry(fd) for _ in range(self.nb_bitmaps)]
+            [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
+             for _ in range(self.nb_bitmaps)]
 
     def dump(self):
         super().dump()
@@ -162,8 +164,9 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         ('u32', '{}', 'extra_data_size')
     )
 
-    def __init__(self, fd):
+    def __init__(self, fd, cluster_size):
         super().__init__(fd=fd)
+        self.cluster_size = cluster_size
         # Seek relative to the current position in the file
         fd.seek(self.extra_data_size, 1)
         bitmap_name = fd.read(self.name_size)
@@ -203,11 +206,13 @@ class QcowHeaderExtension(Qcow2Struct):
         # then padding to next multiply of 8
     )
 
-    def __init__(self, magic=None, length=None, data=None, fd=None):
+    def __init__(self, magic=None, length=None, data=None, fd=None,
+                 cluster_size=None):
         """
         Support both loading from fd and creation from user data.
         For fd-based creation current position in a file will be used to read
         the data.
+        The cluster_size value may be obtained by dependent structures.
 
         This should be somehow refactored and functionality should be moved to
         superclass (to allow creation of any qcow2 struct), but then, fields
@@ -230,7 +235,7 @@ class QcowHeaderExtension(Qcow2Struct):
             assert all(v is None for v in (magic, length, data))
             super().__init__(fd=fd)
             if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
-                self.obj = Qcow2BitmapExt(fd=fd)
+                self.obj = Qcow2BitmapExt(fd=fd, cluster_size=cluster_size)
                 self.data = None
             else:
                 padded = (self.length + 7) & ~7
@@ -319,7 +324,7 @@ class QcowHeader(Qcow2Struct):
             end = self.cluster_size
 
         while fd.tell() < end:
-            ext = QcowHeaderExtension(fd=fd)
+            ext = QcowHeaderExtension(fd=fd, cluster_size=self.cluster_size)
             if ext.magic == 0:
                 break
             else: