[PATCH v9 00/10] iotests: Dump QCOW2 dirty bitmaps metadata

[PATCH v9 00/10] iotests: Dump QCOW2 dirty bitmaps metadata

[Andrey Shinkevich]

Add dirty bitmap information to QCOW2 metadata dump in the qcow2_format.py.

v9:
  01: In patch 0003, removed explicit constructor in the class Qcow2BitmapExt.
  02: In patch 0004, the format string was changed.
 

Andrey Shinkevich (10):
  qcow2: Fix capitalization of header extension constant.
  qcow2_format.py: make printable data an extension class member
  qcow2_format.py: change Qcow2BitmapExt initialization method
  qcow2_format.py: dump bitmap flags in human readable way.
  qcow2_format.py: Dump bitmap directory information
  qcow2_format.py: pass cluster size to substructures
  qcow2_format.py: Dump bitmap table serialized entries
  qcow2.py: Introduce '-j' key to dump in JSON format
  qcow2_format.py: collect fields to dump in JSON format
  qcow2_format.py: support dumping metadata in JSON format

 block/qcow2.c                      |   2 +-
 docs/interop/qcow2.txt             |   2 +-
 tests/qemu-iotests/291.out         |  90 ++++++++++++++++
 tests/qemu-iotests/qcow2.py        |  19 +++-
 tests/qemu-iotests/qcow2_format.py | 213 ++++++++++++++++++++++++++++++++++---
 5 files changed, 304 insertions(+), 22 deletions(-)

-- 
1.8.3.1

[PATCH v9 01/10] qcow2: Fix capitalization of header extension constant.

[Andrey Shinkevich]

Make the capitalization of the hexadecimal numbers consistent for the
QCOW2 header extension constants in docs/interop/qcow2.txt.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/qcow2.c          | 2 +-
 docs/interop/qcow2.txt | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 0cd2e67..80dfe5f 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -66,7 +66,7 @@ typedef struct {
 } QEMU_PACKED QCowExtension;
 
 #define  QCOW2_EXT_MAGIC_END 0
-#define  QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
+#define  QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca
 #define  QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
 #define  QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
 #define  QCOW2_EXT_MAGIC_BITMAPS 0x23852875
diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index cb72346..f072e27 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -231,7 +231,7 @@ be stored. Each extension has a structure like the following:
 
     Byte  0 -  3:   Header extension type:
                         0x00000000 - End of the header extension area
-                        0xE2792ACA - Backing file format name string
+                        0xe2792aca - Backing file format name string
                         0x6803f857 - Feature name table
                         0x23852875 - Bitmaps extension
                         0x0537be77 - Full disk encryption header pointer
-- 
1.8.3.1

[PATCH v9 02/10] qcow2_format.py: make printable data an extension class member

[Andrey Shinkevich]

Let us differ binary data type from string one for the extension data
variable and keep the string as the QcowHeaderExtension class member.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index cc432e7..2f3681b 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -165,6 +165,13 @@ class QcowHeaderExtension(Qcow2Struct):
             self.data = fd.read(padded)
             assert self.data is not None
 
+        data_str = self.data[:self.length]
+        if all(c in string.printable.encode('ascii') for c in data_str):
+            data_str = f"'{ data_str.decode('ascii') }'"
+        else:
+            data_str = '<binary>'
+        self.data_str = data_str
+
         if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
             self.obj = Qcow2BitmapExt(data=self.data)
         else:
@@ -174,12 +181,7 @@ class QcowHeaderExtension(Qcow2Struct):
         super().dump()
 
         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}')
+            print(f'{"data":<25} {self.data_str}')
         else:
             self.obj.dump()
 
-- 
1.8.3.1

[PATCH v9 03/10] qcow2_format.py: change Qcow2BitmapExt initialization method

[Andrey Shinkevich]

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 <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@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

[PATCH v9 04/10] qcow2_format.py: dump bitmap flags in human readable way.

[Andrey Shinkevich]

Introduce the class BitmapFlags that parses a bitmap flags mask.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 9eb6b5b..934062a 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -40,6 +40,22 @@ class Flags64(Qcow2Field):
         return str(bits)
 
 
+class BitmapFlags(Qcow2Field):
+
+    flags = {
+        0x1: 'in-use',
+        0x2: 'auto'
+    }
+
+    def __str__(self):
+        bits = []
+        for bit in range(64):
+            flag = self.value & (1 << bit)
+            if flag:
+                bits.append(self.flags.get(flag, f'bit-{bit}'))
+        return f'{self.value:#x} ({bits})'
+
+
 class Enum(Qcow2Field):
 
     def __str__(self):
-- 
1.8.3.1

[PATCH v9 05/10] qcow2_format.py: Dump bitmap directory information

[Andrey Shinkevich]

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 <kwolf@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/291.out         | 45 ++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/qcow2_format.py | 47 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 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 934062a..1438792 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -129,6 +129,53 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
+    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

[PATCH v9 06/10] qcow2_format.py: pass cluster size to substructures

[Andrey Shinkevich]

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>
---
 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 1438792..d7198a9 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -129,14 +129,16 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
-    def __init__(self, fd):
+    def __init__(self, fd, cluster_size):
         super().__init__(fd=fd)
+        self.cluster_size = cluster_size
         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)]
+            [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
+             for _ in range(self.nb_bitmaps)]
 
     def dump(self):
         super().dump()
@@ -157,8 +159,9 @@ 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)
@@ -198,11 +201,13 @@ 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
@@ -241,7 +246,7 @@ class QcowHeaderExtension(Qcow2Struct):
             # Step back to reread data
             padded = (self.length + 7) & ~7
             fd.seek(-padded, 1)
-            self.obj = Qcow2BitmapExt(fd=fd)
+            self.obj = Qcow2BitmapExt(fd=fd, cluster_size=cluster_size)
             fd.seek(position)
         else:
             self.obj = None
@@ -317,7 +322,7 @@ 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:
-- 
1.8.3.1

[PATCH v9 07/10] qcow2_format.py: Dump bitmap table serialized entries

[Andrey Shinkevich]

Add bitmap table information to the QCOW2 metadata dump.
It extends the output of the test case #291

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/291.out         | 45 ++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/qcow2_format.py | 42 +++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)

diff --git a/tests/qemu-iotests/291.out b/tests/qemu-iotests/291.out
index 53a8eeb..9f465c6 100644
--- a/tests/qemu-iotests/291.out
+++ b/tests/qemu-iotests/291.out
@@ -41,6 +41,15 @@ type                      1
 granularity_bits          19
 name_size                 2
 extra_data_size           0
+Bitmap table   type            offset                   size
+0              serialized      5046272                  65536
+1              all-zeroes      0                        65536
+2              all-zeroes      0                        65536
+3              all-zeroes      0                        65536
+4              all-zeroes      0                        65536
+5              all-zeroes      0                        65536
+6              all-zeroes      0                        65536
+7              all-zeroes      0                        65536
 
 Bitmap name               b2
 bitmap_table_offset       0x500000
@@ -50,6 +59,15 @@ type                      1
 granularity_bits          16
 name_size                 2
 extra_data_size           0
+Bitmap table   type            offset                   size
+0              serialized      5177344                  65536
+1              all-zeroes      0                        65536
+2              all-zeroes      0                        65536
+3              all-zeroes      0                        65536
+4              all-zeroes      0                        65536
+5              all-zeroes      0                        65536
+6              all-zeroes      0                        65536
+7              all-zeroes      0                        65536
 
 
 === Bitmap preservation not possible to non-qcow2 ===
@@ -124,6 +142,15 @@ type                      1
 granularity_bits          19
 name_size                 2
 extra_data_size           0
+Bitmap table   type            offset                   size
+0              serialized      4587520                  65536
+1              all-zeroes      0                        65536
+2              all-zeroes      0                        65536
+3              all-zeroes      0                        65536
+4              all-zeroes      0                        65536
+5              all-zeroes      0                        65536
+6              all-zeroes      0                        65536
+7              all-zeroes      0                        65536
 
 Bitmap name               b2
 bitmap_table_offset       0x490000
@@ -133,6 +160,15 @@ type                      1
 granularity_bits          16
 name_size                 2
 extra_data_size           0
+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
 
 Bitmap name               b0
 bitmap_table_offset       0x510000
@@ -142,6 +178,15 @@ type                      1
 granularity_bits          16
 name_size                 2
 extra_data_size           0
+Bitmap table   type            offset                   size
+0              serialized      5242880                  65536
+1              all-zeroes      0                        65536
+2              all-zeroes      0                        65536
+3              all-zeroes      0                        65536
+4              all-zeroes      0                        65536
+5              all-zeroes      0                        65536
+6              all-zeroes      0                        65536
+7              all-zeroes      0                        65536
 
 
 === Check bitmap contents ===
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index d7198a9..22be3ee 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -170,14 +170,56 @@ 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)
+        position = fd.tell()
+        self.read_bitmap_table(fd)
+        fd.seek(position)
 
     def bitmap_dir_entry_raw_size(self):
         return struct.calcsize(self.fmt) + self.name_size + \
             self.extra_data_size
 
+    def read_bitmap_table(self, fd):
+        fd.seek(self.bitmap_table_offset)
+        table_size = self.bitmap_table_size * 8 * 8
+        table = [e[0] for e in struct.iter_unpack('>Q', fd.read(table_size))]
+        self.bitmap_table = Qcow2BitmapTable(raw_table=table,
+                                             cluster_size=self.cluster_size)
+
     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, raw_table, cluster_size):
+        self.entries = []
+        self.cluster_size = cluster_size
+        for entry in raw_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
-- 
1.8.3.1

[PATCH v9 08/10] qcow2.py: Introduce '-j' key to dump in JSON format

[Andrey Shinkevich]

Add the command key to the qcow2.py arguments list to dump QCOW2
metadata in JSON format. Here is the suggested way to do that. The
implementation of the dump in JSON format is in the patch that follows.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2.py        | 19 +++++++++++++++----
 tests/qemu-iotests/qcow2_format.py | 16 ++++++++--------
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/tests/qemu-iotests/qcow2.py b/tests/qemu-iotests/qcow2.py
index 0910e6a..7402279 100755
--- a/tests/qemu-iotests/qcow2.py
+++ b/tests/qemu-iotests/qcow2.py
@@ -26,16 +26,19 @@ from qcow2_format import (
 )
 
 
+dump_json = False
+
+
 def cmd_dump_header(fd):
     h = QcowHeader(fd)
-    h.dump()
+    h.dump(dump_json)
     print()
-    h.dump_extensions()
+    h.dump_extensions(dump_json)
 
 
 def cmd_dump_header_exts(fd):
     h = QcowHeader(fd)
-    h.dump_extensions()
+    h.dump_extensions(dump_json)
 
 
 def cmd_set_header(fd, name, value):
@@ -134,6 +137,11 @@ cmds = [
 
 
 def main(filename, cmd, args):
+    global dump_json
+    dump_json = '-j' in sys.argv
+    if dump_json:
+        sys.argv.remove('-j')
+        args.remove('-j')
     fd = open(filename, "r+b")
     try:
         for name, handler, num_args, desc in cmds:
@@ -151,11 +159,14 @@ def main(filename, cmd, args):
 
 
 def usage():
-    print("Usage: %s <file> <cmd> [<arg>, ...]" % sys.argv[0])
+    print("Usage: %s <file> <cmd> [<arg>, ...] [<key>, ...]" % sys.argv[0])
     print("")
     print("Supported commands:")
     for name, handler, num_args, desc in cmds:
         print("    %-20s - %s" % (name, desc))
+    print("")
+    print("Supported keys:")
+    print("    %-20s - %s" % ('-j', 'Dump in JSON format'))
 
 
 if __name__ == '__main__':
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 22be3ee..a9bd5a8 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -109,7 +109,7 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
         self.__dict__ = dict((field[2], values[i])
                              for i, field in enumerate(self.fields))
 
-    def dump(self):
+    def dump(self, dump_json=None):
         for f in self.fields:
             value = self.__dict__[f[2]]
             if isinstance(f[1], str):
@@ -140,8 +140,8 @@ class Qcow2BitmapExt(Qcow2Struct):
             [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
              for _ in range(self.nb_bitmaps)]
 
-    def dump(self):
-        super().dump()
+    def dump(self, dump_json=None):
+        super().dump(dump_json)
         for entry in self.bitmap_directory:
             print()
             entry.dump()
@@ -185,7 +185,7 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         self.bitmap_table = Qcow2BitmapTable(raw_table=table,
                                              cluster_size=self.cluster_size)
 
-    def dump(self):
+    def dump(self, dump_json=None):
         print(f'{"Bitmap name":<25} {self.name}')
         super(Qcow2BitmapDirEntry, self).dump()
         self.bitmap_table.dump()
@@ -293,13 +293,13 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             self.obj = None
 
-    def dump(self):
+    def dump(self, dump_json=None):
         super().dump()
 
         if self.obj is None:
             print(f'{"data":<25} {self.data_str}')
         else:
-            self.obj.dump()
+            self.obj.dump(dump_json)
 
     @classmethod
     def create(cls, magic, data):
@@ -398,8 +398,8 @@ class QcowHeader(Qcow2Struct):
         buf = buf[0:header_bytes-1]
         fd.write(buf)
 
-    def dump_extensions(self):
+    def dump_extensions(self, dump_json=None):
         for ex in self.extensions:
             print('Header extension:')
-            ex.dump()
+            ex.dump(dump_json)
             print()
-- 
1.8.3.1

[PATCH v9 09/10] qcow2_format.py: collect fields to dump in JSON format

[Andrey Shinkevich]

As __dict__ is being extended with class members we do not want to
print, make a light copy of the initial __dict__ and extend the copy
by adding lists we have to print in the JSON output.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index a9bd5a8..4ce6d95 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -109,6 +109,8 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
         self.__dict__ = dict((field[2], values[i])
                              for i, field in enumerate(self.fields))
 
+        self.fields_dict = self.__dict__.copy()
+
     def dump(self, dump_json=None):
         for f in self.fields:
             value = self.__dict__[f[2]]
@@ -139,6 +141,7 @@ class Qcow2BitmapExt(Qcow2Struct):
         self.bitmap_directory = \
             [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
              for _ in range(self.nb_bitmaps)]
+        self.fields_dict.update(bitmap_directory=self.bitmap_directory)
 
     def dump(self, dump_json=None):
         super().dump(dump_json)
@@ -184,6 +187,7 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         table = [e[0] for e in struct.iter_unpack('>Q', fd.read(table_size))]
         self.bitmap_table = Qcow2BitmapTable(raw_table=table,
                                              cluster_size=self.cluster_size)
+        self.fields_dict.update(bitmap_table=self.bitmap_table)
 
     def dump(self, dump_json=None):
         print(f'{"Bitmap name":<25} {self.name}')
-- 
1.8.3.1

[PATCH v9 10/10] qcow2_format.py: support dumping metadata in JSON format

[Andrey Shinkevich]

Implementation of dumping QCOW2 image metadata.
The sample output:
{
    "Header_extensions": [
        {
            "name": "Feature table",
            "magic": 1745090647,
            "length": 192,
            "data_str": "<binary>"
        },
        {
            "name": "Bitmaps",
            "magic": 595929205,
            "length": 24,
            "data": {
                "nb_bitmaps": 2,
                "reserved32": 0,
                "bitmap_directory_size": 64,
                "bitmap_directory_offset": 1048576,
                "bitmap_directory": [
                    {
                        "name": "bitmap-1",
                        "bitmap_table_offset": 589824,
                        "bitmap_table_size": 1,
                        "flags": 2,
                        "type": 1,
                        "granularity_bits": 15,
                        "name_size": 8,
                        "extra_data_size": 0,
                        "bitmap_table": {
                            "entries": [
                                {
                                    "type": "serialized",
                                    "offset": 655360
                                },
                                ...

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 59 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 4ce6d95..1b953c1 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -19,6 +19,15 @@
 
 import struct
 import string
+import json
+
+
+class ComplexEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if hasattr(obj, 'get_fields_dict'):
+            return obj.get_fields_dict()
+        else:
+            return json.JSONEncoder.default(self, obj)
 
 
 class Qcow2Field:
@@ -112,6 +121,11 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
         self.fields_dict = self.__dict__.copy()
 
     def dump(self, dump_json=None):
+        if dump_json:
+            print(json.dumps(self.get_fields_dict(), indent=4,
+                             cls=ComplexEncoder))
+            return
+
         for f in self.fields:
             value = self.__dict__[f[2]]
             if isinstance(f[1], str):
@@ -149,6 +163,9 @@ class Qcow2BitmapExt(Qcow2Struct):
             print()
             entry.dump()
 
+    def get_fields_dict(self):
+        return self.fields_dict
+
 
 class Qcow2BitmapDirEntry(Qcow2Struct):
 
@@ -194,6 +211,11 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         super(Qcow2BitmapDirEntry, self).dump()
         self.bitmap_table.dump()
 
+    def get_fields_dict(self):
+        bmp_name = dict(name=self.name)
+        bme_dict = {**bmp_name, **self.fields_dict}
+        return bme_dict
+
 
 class Qcow2BitmapTableEntry:
 
@@ -209,6 +231,9 @@ class Qcow2BitmapTableEntry:
         else:
             self.type = 'all-zeroes'
 
+    def get_fields_dict(self):
+        return dict(type=self.type, offset=self.offset)
+
 
 class Qcow2BitmapTable:
 
@@ -225,6 +250,18 @@ class Qcow2BitmapTable:
         for i, entry in bitmap_table:
             print(f'{i:<14} {entry.type:<15} {entry.offset:<24} {size}')
 
+    def get_fields_dict(self):
+        return dict(entries=self.entries)
+
+
+class Qcow2HeaderExtensionsDoc:
+
+    def __init__(self, extensions):
+        self.extensions = extensions
+
+    def get_fields_dict(self):
+        return dict(Header_extensions=self.extensions)
+
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
@@ -240,6 +277,9 @@ class QcowHeaderExtension(Qcow2Struct):
             0x44415441: 'Data file'
         }
 
+        def get_fields_dict(self):
+            return self.mapping.get(self.value, "<unknown>")
+
     fields = (
         ('u32', Magic, 'magic'),
         ('u32', '{}', 'length')
@@ -305,6 +345,16 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             self.obj.dump(dump_json)
 
+    def get_fields_dict(self):
+        ext_name = dict(name=self.Magic(self.magic))
+        he_dict = {**ext_name, **self.fields_dict}
+        if self.obj is not None:
+            he_dict.update(data=self.obj)
+        else:
+            he_dict.update(data_str=self.data_str)
+
+        return he_dict
+
     @classmethod
     def create(cls, magic, data):
         return QcowHeaderExtension(magic, len(data), data)
@@ -403,7 +453,16 @@ class QcowHeader(Qcow2Struct):
         fd.write(buf)
 
     def dump_extensions(self, dump_json=None):
+        if dump_json:
+            ext_doc = Qcow2HeaderExtensionsDoc(self.extensions)
+            print(json.dumps(ext_doc.get_fields_dict(), indent=4,
+                             cls=ComplexEncoder))
+            return
+
         for ex in self.extensions:
             print('Header extension:')
             ex.dump(dump_json)
             print()
+
+    def get_fields_dict(self):
+        return self.fields_dict
-- 
1.8.3.1

Re: [PATCH v9 00/10] iotests: Dump QCOW2 dirty bitmaps metadata

[Eric Blake]

On 7/13/20 2:27 AM, Andrey Shinkevich wrote:
> Add dirty bitmap information to QCOW2 metadata dump in the qcow2_format.py.
> 
> v9:
>    01: In patch 0003, removed explicit constructor in the class Qcow2BitmapExt.
>    02: In patch 0004, the format string was changed.
>   
> 
> Andrey Shinkevich (10):
>    qcow2: Fix capitalization of header extension constant.
>    qcow2_format.py: make printable data an extension class member
>    qcow2_format.py: change Qcow2BitmapExt initialization method
>    qcow2_format.py: dump bitmap flags in human readable way.
>    qcow2_format.py: Dump bitmap directory information
>    qcow2_format.py: pass cluster size to substructures
>    qcow2_format.py: Dump bitmap table serialized entries
>    qcow2.py: Introduce '-j' key to dump in JSON format
>    qcow2_format.py: collect fields to dump in JSON format
>    qcow2_format.py: support dumping metadata in JSON format
> 
>   block/qcow2.c                      |   2 +-
>   docs/interop/qcow2.txt             |   2 +-
>   tests/qemu-iotests/291.out         |  90 ++++++++++++++++

Test 291 no longer outputs bitmap metadata (see commit 24b861c038); 
which means your patches to 291.out don't make sense.  You'll want to 
respin this to follow the advice in that commit of having a separate 
iotest just for qcow2.py output testing.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH v9 00/10] iotests: Dump QCOW2 dirty bitmaps metadata

[Andrey Shinkevich]

On 13.07.2020 15:41, Eric Blake wrote:
> On 7/13/20 2:27 AM, Andrey Shinkevich wrote:
>> Add dirty bitmap information to QCOW2 metadata dump in the 
>> qcow2_format.py.
>>
>> v9:
>>    01: In patch 0003, removed explicit constructor in the class 
>> Qcow2BitmapExt.
>>    02: In patch 0004, the format string was changed.
>>
>> Andrey Shinkevich (10):
>>    qcow2: Fix capitalization of header extension constant.
>>    qcow2_format.py: make printable data an extension class member
>>    qcow2_format.py: change Qcow2BitmapExt initialization method
>>    qcow2_format.py: dump bitmap flags in human readable way.
>>    qcow2_format.py: Dump bitmap directory information
>>    qcow2_format.py: pass cluster size to substructures
>>    qcow2_format.py: Dump bitmap table serialized entries
>>    qcow2.py: Introduce '-j' key to dump in JSON format
>>    qcow2_format.py: collect fields to dump in JSON format
>>    qcow2_format.py: support dumping metadata in JSON format
>>
>>   block/qcow2.c                      |   2 +-
>>   docs/interop/qcow2.txt             |   2 +-
>>   tests/qemu-iotests/291.out         |  90 ++++++++++++++++
>
> Test 291 no longer outputs bitmap metadata (see commit 24b861c038); 
> which means your patches to 291.out don't make sense.  You'll want to 
> respin this to follow the advice in that commit of having a separate 
> iotest just for qcow2.py output testing.
>
I noted that #291 fails in the main stream branch and was not able to 
test my patch to 291.out with that. I will take a close look at the 
commit 24b861c038, thank you.

Andrey