xref: /qemu/tests/qemu-iotests/250 (revision 37677d7d) 
1#!/usr/bin/env bash
2#
3# Test big discard in qcow2 shrink
4#
5# Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved.
6#
7# This program is free software; you can redistribute it and/or modify
8# it under the terms of the GNU General Public License as published by
9# the Free Software Foundation; either version 2 of the License, or
10# (at your option) any later version.
11#
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16#
17# You should have received a copy of the GNU General Public License
18# along with this program.  If not, see <http://www.gnu.org/licenses/>.
19#
20
21# creator
22owner=vsementsov@virtuozzo.com
23
24seq=`basename $0`
25echo "QA output created by $seq"
26
27status=1	# failure is the default!
28
29_cleanup()
30{
31    _cleanup_test_img
32}
33trap "_cleanup; exit \$status" 0 1 2 3 15
34
35# get standard environment, filters and checks
36. ./common.rc
37. ./common.filter
38
39_supported_fmt qcow2
40_supported_proto file
41_supported_os Linux
42
43# This test checks that qcow2_process_discards does not truncate a discard
44# request > 2G.
45# To reproduce bug we need to overflow int by one sequential discard, so we
46# need size > 2G, bigger cluster size (as with default 64k we may have maximum
47# of 512M sequential data, corresponding to one L1 entry), and we need some
48# data of the beginning of the disk mapped to the end of file to prevent
49# bdrv_co_truncate(bs->file) call in qcow2_co_truncate(), which might succeed
50# anyway.
51
52disk_usage()
53{
54    du --block-size=1 $1 | awk '{print $1}'
55}
56
57size=2100M
58IMGOPTS="cluster_size=1M,preallocation=metadata"
59
60_make_test_img $size
61$QEMU_IO -c 'discard 0 10M' -c 'discard 2090M 10M' \
62         -c 'write 2090M 10M' -c 'write 0 10M' "$TEST_IMG" | _filter_qemu_io
63
64# Check that our trick with swapping first and last 10M chunks succeeded.
65# Otherwise test may pass even if bdrv_pdiscard() fails in
66# qcow2_process_discards()
67$QEMU_IMG map "$TEST_IMG" | _filter_testdir
68
69before=$(disk_usage "$TEST_IMG")
70$QEMU_IMG resize --shrink "$TEST_IMG" 5M
71after=$(disk_usage "$TEST_IMG")
72
73echo "Disk usage delta: $((before - after))"
74
75# success, all done
76echo "*** done"
77rm -f $seq.full
78status=0
79