xref: /openbmc/qemu/tests/qemu-iotests/220 (revision 812b31d3)
1#!/usr/bin/env bash
2# group: rw auto
3#
4# max limits on compression in huge qcow2 files
5#
6# Copyright (C) 2018 Red Hat, Inc.
7#
8# This program is free software; you can redistribute it and/or modify
9# it under the terms of the GNU General Public License as published by
10# the Free Software Foundation; either version 2 of the License, or
11# (at your option) any later version.
12#
13# This program is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16# GNU General Public License for more details.
17#
18# You should have received a copy of the GNU General Public License
19# along with this program.  If not, see <http://www.gnu.org/licenses/>.
20#
21
22seq=$(basename $0)
23echo "QA output created by $seq"
24
25status=1    # failure is the default!
26
27_cleanup()
28{
29    _cleanup_test_img
30}
31trap "_cleanup; exit \$status" 0 1 2 3 15
32
33# get standard environment, filters and checks
34. ./common.rc
35. ./common.filter
36. ./common.pattern
37
38_supported_fmt qcow2
39_supported_proto file fuse
40_supported_os Linux
41# To use a different refcount width but 16 bits we need compat=1.1,
42# and external data files do not support compressed clusters.
43_unsupported_imgopts 'compat=0.10' data_file
44
45echo "== Creating huge file =="
46
47# Sanity check: We require a file system that permits the creation
48# of a HUGE (but very sparse) file.  tmpfs works, ext4 does not.
49_require_large_file 513T
50
51_make_test_img -o 'cluster_size=2M,refcount_bits=1' 513T
52
53echo "== Populating refcounts =="
54# We want an image with 256M refcounts * 2M clusters = 512T referenced.
55# Each 2M cluster holds 16M refcounts; the refcount table initially uses
56# 1 refblock, so we need to add 15 more.  The refcount table lives at 2M,
57# first refblock at 4M, L2 at 6M, so our remaining additions start at 8M.
58# Then, for each refblock, mark it as fully populated.
59to_hex() {
60    printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g'
61}
62truncate --size=38m "$TEST_IMG"
63entry=$((0x200000))
64$QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io
65for i in {1..15}; do
66    offs=$((0x600000 + i*0x200000))
67    poke_file "$TEST_IMG" $((i*8 + entry)) $(to_hex $offs)
68    $QEMU_IO_PROG -f raw -c "w -P 0xff $offs 2m" "$TEST_IMG" | _filter_qemu_io
69done
70
71echo "== Checking file before =="
72# FIXME: 'qemu-img check' doesn't diagnose refcounts beyond the end of
73# the file as leaked clusters
74_check_test_img 2>&1 | sed '/^Leaked cluster/d'
75stat -c 'image size %s' "$TEST_IMG"
76
77echo "== Trying to write compressed cluster =="
78# Given our file size, the next available cluster at 512T lies beyond the
79# maximum offset that a compressed 2M cluster can reside in
80$QEMU_IO_PROG -c 'w -c 0 2m' "$TEST_IMG" | _filter_qemu_io
81# The attempt failed, but ended up allocating a new refblock
82stat -c 'image size %s' "$TEST_IMG"
83
84echo "== Writing normal cluster =="
85# The failed write should not corrupt the image, so a normal write succeeds
86$QEMU_IO_PROG -c 'w 0 2m' "$TEST_IMG" | _filter_qemu_io
87
88echo "== Checking file after =="
89# qemu-img now sees the millions of leaked clusters, thanks to the allocations
90# at 512T.  Undo many of our faked references to speed up the check.
91$QEMU_IO_PROG -f raw -c "w -z 5m 1m" -c "w -z 8m 30m" "$TEST_IMG" |
92    _filter_qemu_io
93_check_test_img 2>&1 | sed '/^Leaked cluster/d'
94
95# success, all done
96echo "*** done"
97rm -f $seq.full
98status=0
99