iotests: add test for QCOW2 header dump

The simple script creates a QCOW2 image and fills it with some data.
Two bitmaps are created as well. Then the script reads the image header
with extensions from the disk by running the script qcow2.py and dumps
the information to the output. Other entities, such as snapshots, may
be added to the test later.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1596742557-320265-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

tests/qemu-iotests/303

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+#
+# Test for dumping of qcow2 image metadata
+#
+# Copyright (c) 2020 Virtuozzo International GmbH
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import iotests
+import subprocess
+from iotests import qemu_img_create, qemu_io, file_path, log, filter_qemu_io
+
+iotests.script_initialize(supported_fmts=['qcow2'])
+
+disk = file_path('disk')
+chunk = 1024 * 1024
+
+
+def create_bitmap(bitmap_number, disabled):
+    granularity = 1 << (14 + bitmap_number)
+    bitmap_name = 'bitmap-' + str(bitmap_number)
+    args = ['bitmap', '--add', '-g', f'{granularity}', '-f', iotests.imgfmt,
+            disk, bitmap_name]
+    if disabled:
+        args.append('--disable')
+
+    iotests.qemu_img_pipe(*args)
+
+
+def write_to_disk(offset, size):
+    write = f'write {offset} {size}'
+    log(qemu_io('-c', write, disk), filters=[filter_qemu_io])
+
+
+def add_bitmap(num, begin, end, disabled):
+    log(f'Add bitmap {num}')
+    create_bitmap(num, disabled)
+    for i in range(begin, end):
+        write_to_disk((i) * chunk, chunk)
+    log('')
+
+
+qemu_img_create('-f', iotests.imgfmt, disk, '10M')
+
+add_bitmap(1, 0, 6, False)
+add_bitmap(2, 6, 8, True)
+dump = ['qcow2.py', disk, 'dump-header']
+subprocess.run(dump)

tests/qemu-iotests/303.out

@@ -0,0 +1,60 @@
+Add bitmap 1
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+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)
+
+wrote 1048576/1048576 bytes at offset 3145728
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 4194304
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 5242880
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+
+Add bitmap 2
+wrote 1048576/1048576 bytes at offset 6291456
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 7340032
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      10485760
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     []
+compatible_features       []
+autoclear_features        [0]
+refcount_order            4
+header_length             112
+
+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   0x9d0000
+

tests/qemu-iotests/group

@@ -309,4 +309,5 @@
 299 auto quick
 301 backing quick
 302 quick
+303 rw quick
 304 rw quick