1#!/usr/bin/env python3
2# group: rw
3#
4# Test graph changes while I/O is happening
5#
6# Copyright (C) 2022 Red Hat, Inc.
7#
8# This program is free software; you can redistribute it and/or modify
9# it under the terms of the GNU General Public License as published by
10# the Free Software Foundation; either version 2 of the License, or
11# (at your option) any later version.
12#
13# This program is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16# GNU General Public License for more details.
17#
18# You should have received a copy of the GNU General Public License
19# along with this program.  If not, see <http://www.gnu.org/licenses/>.
20#
21
22import os
23from threading import Thread
24import iotests
25from iotests import imgfmt, qemu_img, qemu_img_create, QMPTestCase, \
26        QemuStorageDaemon
27
28
29top = os.path.join(iotests.test_dir, 'top.img')
30nbd_sock = os.path.join(iotests.sock_dir, 'nbd.sock')
31
32
33def do_qemu_img_bench() -> None:
34    """
35    Do some I/O requests on `nbd_sock`.
36    """
37    assert qemu_img('bench', '-f', 'raw', '-c', '2000000',
38                    f'nbd+unix:///node0?socket={nbd_sock}') == 0
39
40
41class TestGraphChangesWhileIO(QMPTestCase):
42    def setUp(self) -> None:
43        # Create an overlay that can be added at runtime on top of the
44        # null-co block node that will receive I/O
45        assert qemu_img_create('-f', imgfmt, '-F', 'raw', '-b', 'null-co://',
46                               top) == 0
47
48        # QSD instance with a null-co block node in an I/O thread,
49        # exported over NBD (on `nbd_sock`, export name "node0")
50        self.qsd = QemuStorageDaemon(
51            '--object', 'iothread,id=iothread0',
52            '--blockdev', 'null-co,node-name=node0,read-zeroes=true',
53            '--nbd-server', f'addr.type=unix,addr.path={nbd_sock}',
54            '--export', 'nbd,id=exp0,node-name=node0,iothread=iothread0,' +
55                        'fixed-iothread=true,writable=true',
56            qmp=True
57        )
58
59    def tearDown(self) -> None:
60        self.qsd.stop()
61
62    def test_blockdev_add_while_io(self) -> None:
63        # Run qemu-img bench in the background
64        bench_thr = Thread(target=do_qemu_img_bench)
65        bench_thr.start()
66
67        # While qemu-img bench is running, repeatedly add and remove an
68        # overlay to/from node0
69        while bench_thr.is_alive():
70            result = self.qsd.qmp('blockdev-add', {
71                'driver': imgfmt,
72                'node-name': 'overlay',
73                'backing': 'node0',
74                'file': {
75                    'driver': 'file',
76                    'filename': top
77                }
78            })
79            self.assert_qmp(result, 'return', {})
80
81            result = self.qsd.qmp('blockdev-del', {
82                'node-name': 'overlay'
83            })
84            self.assert_qmp(result, 'return', {})
85
86        bench_thr.join()
87
88if __name__ == '__main__':
89    # Format must support raw backing files
90    iotests.main(supported_fmts=['qcow', 'qcow2', 'qed'],
91                 supported_protocols=['file'])
92