iotests: add #310 to test bottom node in COR driver

The test case #310 is similar to #216 by Max Reitz. The difference is
that the test #310 involves a bottom node to the COR filter driver.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  [vsementsov: detach backing to test reads from top, limit to qcow2]
Message-Id: <20201216061703.70908-7-vsementsov@virtuozzo.com>
[mreitz: Add "# group:" line]
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/310

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+# group: rw quick
+#
+# Copy-on-read tests using a COR filter with a bottom node
+#
+# Copyright (C) 2018 Red Hat, Inc.
+# 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
+from iotests import log, qemu_img, qemu_io_silent
+
+# Need backing file support
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
+
+log('')
+log('=== Copy-on-read across nodes ===')
+log('')
+
+# This test is similar to the 216 one by Max Reitz <mreitz@redhat.com>
+# The difference is that this test case involves a bottom node to the
+# COR filter driver.
+
+with iotests.FilePath('base.img') as base_img_path, \
+     iotests.FilePath('mid.img') as mid_img_path, \
+     iotests.FilePath('top.img') as top_img_path, \
+     iotests.VM() as vm:
+
+    log('--- Setting up images ---')
+    log('')
+
+    assert qemu_img('create', '-f', iotests.imgfmt, base_img_path, '64M') == 0
+    assert qemu_io_silent(base_img_path, '-c', 'write -P 1 0M 1M') == 0
+    assert qemu_io_silent(base_img_path, '-c', 'write -P 1 3M 1M') == 0
+    assert qemu_img('create', '-f', iotests.imgfmt, '-b', base_img_path,
+                    '-F', iotests.imgfmt, mid_img_path) == 0
+    assert qemu_io_silent(mid_img_path,  '-c', 'write -P 3 2M 1M') == 0
+    assert qemu_io_silent(mid_img_path,  '-c', 'write -P 3 4M 1M') == 0
+    assert qemu_img('create', '-f', iotests.imgfmt, '-b', mid_img_path,
+                    '-F', iotests.imgfmt, top_img_path) == 0
+    assert qemu_io_silent(top_img_path,  '-c', 'write -P 2 1M 1M') == 0
+
+#      0 1 2 3 4
+# top    2
+# mid      3   3
+# base 1     1
+
+    log('Done')
+
+    log('')
+    log('--- Doing COR ---')
+    log('')
+
+    vm.launch()
+
+    log(vm.qmp('blockdev-add',
+               node_name='node0',
+               driver='copy-on-read',
+               bottom='node2',
+               file={
+                   'driver': iotests.imgfmt,
+                   'file': {
+                       'driver': 'file',
+                       'filename': top_img_path
+                   },
+                   'backing': {
+                       'node-name': 'node2',
+                       'driver': iotests.imgfmt,
+                       'file': {
+                           'driver': 'file',
+                           'filename': mid_img_path
+                       },
+                       'backing': {
+                           'driver': iotests.imgfmt,
+                           'file': {
+                               'driver': 'file',
+                               'filename': base_img_path
+                           }
+                       },
+                   }
+               }))
+
+    # Trigger COR
+    log(vm.qmp('human-monitor-command',
+               command_line='qemu-io node0 "read 0 5M"'))
+
+    vm.shutdown()
+
+    log('')
+    log('--- Checking COR result ---')
+    log('')
+
+    # Detach backing to check that we can read the data from the top level now
+    assert qemu_img('rebase', '-u', '-b', '', '-f', iotests.imgfmt,
+                    top_img_path) == 0
+
+    assert qemu_io_silent(top_img_path,  '-c', 'read -P 0 0 1M') == 0
+    assert qemu_io_silent(top_img_path,  '-c', 'read -P 2 1M 1M') == 0
+    assert qemu_io_silent(top_img_path,  '-c', 'read -P 3 2M 1M') == 0
+    assert qemu_io_silent(top_img_path,  '-c', 'read -P 0 3M 1M') == 0
+    assert qemu_io_silent(top_img_path,  '-c', 'read -P 3 4M 1M') == 0
+
+    log('Done')

tests/qemu-iotests/310.out

@@ -0,0 +1,15 @@
+
+=== Copy-on-read across nodes ===
+
+--- Setting up images ---
+
+Done
+
+--- Doing COR ---
+
+{"return": {}}
+{"return": ""}
+
+--- Checking COR result ---
+
+Done

tests/qemu-iotests/group

@@ -318,4 +318,5 @@
 307 rw quick export
 308 rw
 309 rw auto quick
+310 rw quick
 312 rw quick