Previously, bdrv_pad_request() could not deal with a NULL qiov when a read needed to be aligned. During prefetch, a stream job will pass a NULL qiov. Add a test case to cover this scenario.
By accident, also covers a previous race during shutdown, where block graph changes during iteration in bdrv_flush_all() could lead to unreferencing the wrong block driver state and an assertion failure later. Signed-off-by: Fiona Ebner <f.eb...@proxmox.com> --- No changes in v3. New in v2. .../tests/stream-unaligned-prefetch | 86 +++++++++++++++++++ .../tests/stream-unaligned-prefetch.out | 5 ++ 2 files changed, 91 insertions(+) create mode 100755 tests/qemu-iotests/tests/stream-unaligned-prefetch create mode 100644 tests/qemu-iotests/tests/stream-unaligned-prefetch.out diff --git a/tests/qemu-iotests/tests/stream-unaligned-prefetch b/tests/qemu-iotests/tests/stream-unaligned-prefetch new file mode 100755 index 0000000000..546db1d369 --- /dev/null +++ b/tests/qemu-iotests/tests/stream-unaligned-prefetch @@ -0,0 +1,86 @@ +#!/usr/bin/env python3 +# group: rw quick +# +# Test what happens when a stream job does an unaligned prefetch read +# which requires padding while having a NULL qiov. +# +# Copyright (C) Proxmox Server Solutions 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 os +import iotests +from iotests import imgfmt, qemu_img_create, qemu_io, QMPTestCase + +image_size = 1 * 1024 * 1024 +cluster_size = 64 * 1024 +base = os.path.join(iotests.test_dir, 'base.img') +top = os.path.join(iotests.test_dir, 'top.img') + +class TestStreamUnalignedPrefetch(QMPTestCase): + def setUp(self) -> None: + """ + Create two images: + - base image {base} with {cluster_size // 2} bytes allocated + - top image {top} without any data allocated and coarser + cluster size + + Attach a compress filter for the top image, because that + requires that the request alignment is the top image's cluster + size. + """ + qemu_img_create('-f', imgfmt, + '-o', 'cluster_size={}'.format(cluster_size // 2), + base, str(image_size)) + qemu_io('-c', f'write 0 {cluster_size // 2}', base) + qemu_img_create('-f', imgfmt, + '-o', 'cluster_size={}'.format(cluster_size), + top, str(image_size)) + + self.vm = iotests.VM() + self.vm.add_blockdev(self.vm.qmp_to_opts({ + 'driver': imgfmt, + 'node-name': 'base', + 'file': { + 'driver': 'file', + 'filename': base + } + })) + self.vm.add_blockdev(self.vm.qmp_to_opts({ + 'driver': 'compress', + 'node-name': 'compress-top', + 'file': { + 'driver': imgfmt, + 'node-name': 'top', + 'file': { + 'driver': 'file', + 'filename': top + }, + 'backing': 'base' + } + })) + self.vm.launch() + + def tearDown(self) -> None: + self.vm.shutdown() + os.remove(top) + os.remove(base) + + def test_stream_unaligned_prefetch(self) -> None: + self.vm.cmd('block-stream', job_id='stream', device='compress-top') + + +if __name__ == '__main__': + iotests.main(supported_fmts=['qcow2'], supported_protocols=['file']) diff --git a/tests/qemu-iotests/tests/stream-unaligned-prefetch.out b/tests/qemu-iotests/tests/stream-unaligned-prefetch.out new file mode 100644 index 0000000000..ae1213e6f8 --- /dev/null +++ b/tests/qemu-iotests/tests/stream-unaligned-prefetch.out @@ -0,0 +1,5 @@ +. +---------------------------------------------------------------------- +Ran 1 tests + +OK -- 2.39.2
