diff mbox series

[v11,07/11] qcow2_format.py: Dump bitmap table serialized entries

Message ID 1594973699-781898-8-git-send-email-andrey.shinkevich@virtuozzo.com (mailing list archive)
State New, archived
Headers show
Series iotests: Dump QCOW2 dirty bitmaps metadata | expand

Commit Message

Andrey Shinkevich July 17, 2020, 8:14 a.m. UTC
Add bitmap table information to the QCOW2 metadata dump.

Bitmap name               bitmap-1
...
Bitmap table   type            offset                   size
0              serialized      4718592                  65536
1              serialized      4294967296               65536
2              serialized      5348033147437056         65536
3              serialized      13792273858822144        65536
4              serialized      4718592                  65536
5              serialized      4294967296               65536
6              serialized      4503608217305088         65536
7              serialized      14073748835532800        65536

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 41 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

Comments

Vladimir Sementsov-Ogievskiy July 28, 2020, 10:02 a.m. UTC | #1
17.07.2020 11:14, Andrey Shinkevich wrote:
> Add bitmap table information to the QCOW2 metadata dump.
> 
> Bitmap name               bitmap-1
> ...
> Bitmap table   type            offset                   size
> 0              serialized      4718592                  65536
> 1              serialized      4294967296               65536
> 2              serialized      5348033147437056         65536
> 3              serialized      13792273858822144        65536
> 4              serialized      4718592                  65536
> 5              serialized      4294967296               65536
> 6              serialized      4503608217305088         65536
> 7              serialized      14073748835532800        65536

big numbers seems unrelated. Did you updated commit-msg after fixing s/* 8 * 8/* 8/ bug of v10?

> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
>   tests/qemu-iotests/qcow2_format.py | 41 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 41 insertions(+)
> 
> diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
> index ca0d350..ad1918c 100644
> --- a/tests/qemu-iotests/qcow2_format.py
> +++ b/tests/qemu-iotests/qcow2_format.py
> @@ -175,6 +175,10 @@ 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)
> +        self.bitmap_table = Qcow2BitmapTable(fd=fd,
> +                                             offset=self.bitmap_table_offset,
> +                                             size=self.bitmap_table_size,
> +                                             cluster_size=self.cluster_size)
>   
>       def bitmap_dir_entry_raw_size(self):
>           return struct.calcsize(self.fmt) + self.name_size + \
> @@ -183,6 +187,43 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
>       def dump(self):
>           print(f'{"Bitmap name":<25} {self.name}')
>           super(Qcow2BitmapDirEntry, self).dump()
> +        self.bitmap_table.dump()
> +
> +
> +class Qcow2BitmapTableEntry:

Why not to derive it from Qcow2Struct? It will have only one field, but it will work, and we don't need to open-code loading in Qcow2BitmapTable

> +
> +    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'

Would be good to note if reserved bits are set, as well as wrong combination of offset and all-ones bit.

> +
> +
> +class Qcow2BitmapTable:
> +
> +    def __init__(self, fd, offset, size, cluster_size):
> +        self.entries = []
> +        self.cluster_size = cluster_size
> +        table_size = size * 8

you may rename size to nb_entries, to make it obvious what "size" is (I know, that it's my idea to call it "size" in qcow2 spec. Probably bad one).

> +        position = fd.tell()
> +        fd.seek(offset)
> +        table = [e[0] for e in struct.iter_unpack('>Q', fd.read(table_size))]

this should be self.entries = [Qcow2BitmapTableEntry(fd) for _ in range(nb_entries)]

> +        fd.seek(position)
> +        for entry in 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
>
diff mbox series

Patch

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index ca0d350..ad1918c 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -175,6 +175,10 @@  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)
+        self.bitmap_table = Qcow2BitmapTable(fd=fd,
+                                             offset=self.bitmap_table_offset,
+                                             size=self.bitmap_table_size,
+                                             cluster_size=self.cluster_size)
 
     def bitmap_dir_entry_raw_size(self):
         return struct.calcsize(self.fmt) + self.name_size + \
@@ -183,6 +187,43 @@  class Qcow2BitmapDirEntry(Qcow2Struct):
     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, fd, offset, size, cluster_size):
+        self.entries = []
+        self.cluster_size = cluster_size
+        table_size = size * 8
+        position = fd.tell()
+        fd.seek(offset)
+        table = [e[0] for e in struct.iter_unpack('>Q', fd.read(table_size))]
+        fd.seek(position)
+        for entry in 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