new file mode 100644
@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+#
+# Test for preallocate filter
+#
+# 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 os
+import iotests
+from iotests import log
+
+iotests.script_initialize(supported_fmts=['qcow2'])
+
+size = 10 * 1024 * 1024
+disk = iotests.file_path('disk')
+
+iotests.qemu_img_create('-f', iotests.imgfmt, disk, str(size))
+
+opts = f'driver={iotests.imgfmt},' \
+ f'file.driver=preallocate,file.file.filename={disk}'
+p = iotests.QemuIoInteractive('--image-opts', '-t', 'none', opts)
+
+log(p.cmd('write 0 1M'), filters=[iotests.filter_qemu_io])
+p.cmd('flush')
+
+if os.path.getsize(disk) > 100 * 1024 * 1024:
+ log('file in progress is big, preallocation works')
+
+p.close()
+
+if os.path.getsize(disk) < 10 * 1024 * 1024:
+ log('file is small after close')
new file mode 100644
@@ -0,0 +1,5 @@
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+file in progress is big, preallocation works
+file is small after close
@@ -302,3 +302,4 @@
291 rw quick
292 rw auto quick
297 meta
+298 meta
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- tests/qemu-iotests/298 | 45 ++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/298.out | 5 +++++ tests/qemu-iotests/group | 1 + 3 files changed, 51 insertions(+) create mode 100644 tests/qemu-iotests/298 create mode 100644 tests/qemu-iotests/298.out