xref: /openbmc/qemu/tests/qemu-iotests/115 (revision d1972be1)
1#!/usr/bin/env bash
2#
3# Test case for non-self-referential qcow2 refcount blocks
4#
5# Copyright (C) 2014 Red Hat, Inc.
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=mreitz@redhat.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# This test relies on refcounts being 64 bits wide (which does not work with
42# compat=0.10)
43_unsupported_imgopts 'refcount_bits=\([^6]\|.\([^4]\|$\)\)' 'compat=0.10'
44
45echo
46echo '=== Testing large refcount and L1 table ==='
47echo
48
49# Create an image with an L1 table and a refcount table that each span twice the
50# number of clusters which can be described by a single refblock; therefore, at
51# least two refblocks cannot count their own refcounts because all the clusters
52# they describe are part of the L1 table or refcount table.
53
54# One refblock can describe (with cluster_size=512 and refcount_bits=64)
55# 512/8 = 64 clusters, therefore the L1 table should cover 128 clusters, which
56# equals 128 * (512/8) = 8192 entries (actually, 8192 - 512/8 = 8129 would
57# suffice, but it does not really matter). 8192 L2 tables can in turn describe
58# 8192 * 512/8 = 524,288 clusters which cover a space of 256 MB.
59
60# Since with refcount_bits=64 every refcount block entry is 64 bits wide (just
61# like the L2 table entries), the same calculation applies to the refcount table
62# as well; the difference is that while for the L1 table the guest disk size is
63# concerned, for the refcount table it is the image length that has to be at
64# least 256 MB. We can achieve that by using preallocation=metadata for an image
65# which has a guest disk size of 256 MB.
66
67_make_test_img -o "refcount_bits=64,cluster_size=512,preallocation=metadata" 256M
68
69# We know for sure that the L1 and refcount tables do not overlap with any other
70# structure because the metadata overlap checks would have caught that case.
71
72# Because qemu refuses to open qcow2 files whose L1 table does not cover the
73# whole guest disk size, it is definitely large enough. On the other hand, to
74# test whether the refcount table is large enough, we simply have to verify that
75# indeed all the clusters are allocated, which is done by qemu-img check.
76
77# The final thing we need to test is whether the tables are actually covered by
78# refcount blocks; since all clusters of the tables are referenced, we can use
79# qemu-img check for that purpose, too.
80
81$QEMU_IMG check "$TEST_IMG" | \
82    sed -e 's/^.* = \([0-9]\+\.[0-9]\+% allocated\).*\(clusters\)$/\1 \2/' \
83        -e '/^Image end offset/d'
84
85# (Note that we cannot use _check_test_img because that function filters out the
86# allocation status)
87
88# success, all done
89echo '*** done'
90rm -f $seq.full
91status=0
92