The testcase simply creates a 64G image with 1M clusters, generates a list of 1M aligned offsets and feeds aio_write commands with those offsets to qemu-io run with '--aio native --nocache'. Then we check the data written at each of the offsets. Before the previous commit this could result into a race within the preallocation filter which would zeroize some clusters after actually writing data to them.
Note: the test doesn't fail in 100% cases as there's a race involved, but the failures are pretty consistent so it should be good enough for detecting the problem. Signed-off-by: Andrey Drobyshev <andrey.drobys...@virtuozzo.com> --- tests/qemu-iotests/298 | 34 ++++++++++++++++++++++++++++++++++ tests/qemu-iotests/298.out | 4 ++-- 2 files changed, 36 insertions(+), 2 deletions(-) diff --git a/tests/qemu-iotests/298 b/tests/qemu-iotests/298 index 09c9290711..d1bf5ee0df 100755 --- a/tests/qemu-iotests/298 +++ b/tests/qemu-iotests/298 @@ -20,8 +20,10 @@ import os import iotests +import random MiB = 1024 * 1024 +GiB = MiB * 1024 disk = os.path.join(iotests.test_dir, 'disk') overlay = os.path.join(iotests.test_dir, 'overlay') refdisk = os.path.join(iotests.test_dir, 'refdisk') @@ -176,5 +178,37 @@ class TestTruncate(iotests.QMPTestCase): self.do_test('off', '150M') +class TestPreallocAsyncWrites(iotests.QMPTestCase): + def setUp(self): + # Make sure we get reproducible write patterns on each run + random.seed(42) + iotests.qemu_img_create('-f', iotests.imgfmt, disk, '-o', + f'cluster_size={MiB},lazy_refcounts=on', + str(64 * GiB)) + + def tearDown(self): + os.remove(disk) + + def test_prealloc_async_writes(self): + requests = 1024 # Number of write/read requests to feed to qemu-io + total_clusters = 64 * 1024 # 64G / 1M + + offsets = random.sample(range(0, total_clusters), requests) + aio_write_cmds = [f'aio_write -P 0xaa {off}M 1M' for off in offsets] + read_cmds = [f'read -P 0xaa {off}M 1M' for off in offsets] + + proc = iotests.QemuIoInteractive('--aio', 'native', '--nocache', + '--image-opts', drive_opts) + for cmd in aio_write_cmds: + proc.cmd(cmd) + proc.close() + + proc = iotests.QemuIoInteractive('-f', iotests.imgfmt, disk) + for cmd in read_cmds: + out = proc.cmd(cmd) + self.assertFalse('Pattern verification failed' in str(out)) + proc.close() + + if __name__ == '__main__': iotests.main(supported_fmts=['qcow2'], required_fmts=['preallocate']) diff --git a/tests/qemu-iotests/298.out b/tests/qemu-iotests/298.out index fa16b5ccef..6323079e08 100644 --- a/tests/qemu-iotests/298.out +++ b/tests/qemu-iotests/298.out @@ -1,5 +1,5 @@ -............. +.............. ---------------------------------------------------------------------- -Ran 13 tests +Ran 14 tests OK -- 2.39.3