xref: /openbmc/qemu/tests/qemu-iotests/115 (revision bfa3ab61)
1#!/bin/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 $seq"
26
27here="$PWD"
28tmp=/tmp/$$
29status=1	# failure is the default!
30
31_cleanup()
32{
33	_cleanup_test_img
34}
35trap "_cleanup; exit \$status" 0 1 2 3 15
36
37# get standard environment, filters and checks
38. ./common.rc
39. ./common.filter
40
41_supported_fmt qcow2
42_supported_proto file
43_supported_os Linux
44# This test relies on refcounts being 64 bits wide (which does not work with
45# compat=0.10)
46_unsupported_imgopts 'refcount_bits=\([^6]\|.\([^4]\|$\)\)' 'compat=0.10'
47
48echo
49echo '=== Testing large refcount and L1 table ==='
50echo
51
52# Create an image with an L1 table and a refcount table that each span twice the
53# number of clusters which can be described by a single refblock; therefore, at
54# least two refblocks cannot count their own refcounts because all the clusters
55# they describe are part of the L1 table or refcount table.
56
57# One refblock can describe (with cluster_size=512 and refcount_bits=64)
58# 512/8 = 64 clusters, therefore the L1 table should cover 128 clusters, which
59# equals 128 * (512/8) = 8192 entries (actually, 8192 - 512/8 = 8129 would
60# suffice, but it does not really matter). 8192 L2 tables can in turn describe
61# 8192 * 512/8 = 524,288 clusters which cover a space of 256 MB.
62
63# Since with refcount_bits=64 every refcount block entry is 64 bits wide (just
64# like the L2 table entries), the same calculation applies to the refcount table
65# as well; the difference is that while for the L1 table the guest disk size is
66# concerned, for the refcount table it is the image length that has to be at
67# least 256 MB. We can achieve that by using preallocation=metadata for an image
68# which has a guest disk size of 256 MB.
69
70IMGOPTS="$IMGOPTS,refcount_bits=64,cluster_size=512,preallocation=metadata" \
71    _make_test_img 256M
72
73# We know for sure that the L1 and refcount tables do not overlap with any other
74# structure because the metadata overlap checks would have caught that case.
75
76# Because qemu refuses to open qcow2 files whose L1 table does not cover the
77# whole guest disk size, it is definitely large enough. On the other hand, to
78# test whether the refcount table is large enough, we simply have to verify that
79# indeed all the clusters are allocated, which is done by qemu-img check.
80
81# The final thing we need to test is whether the tables are actually covered by
82# refcount blocks; since all clusters of the tables are referenced, we can use
83# qemu-img check for that purpose, too.
84
85$QEMU_IMG check "$TEST_IMG" | \
86    sed -e 's/^.* = \([0-9]\+\.[0-9]\+% allocated\).*\(clusters\)$/\1 \2/' \
87        -e '/^Image end offset/d'
88
89# (Note that we cannot use _check_test_img because that function filters out the
90# allocation status)
91
92# success, all done
93echo '*** done'
94rm -f $seq.full
95status=0
96