1#!/usr/bin/env bash 2# 3# max limits on compression in huge qcow2 files 4# 5# Copyright (C) 2018 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 21seq=$(basename $0) 22echo "QA output created by $seq" 23 24status=1 # failure is the default! 25 26_cleanup() 27{ 28 _cleanup_test_img 29} 30trap "_cleanup; exit \$status" 0 1 2 3 15 31 32# get standard environment, filters and checks 33. ./common.rc 34. ./common.filter 35. ./common.pattern 36 37_supported_fmt qcow2 38_supported_proto file 39_supported_os Linux 40 41echo "== Creating huge file ==" 42 43# Sanity check: We require a file system that permits the creation 44# of a HUGE (but very sparse) file. tmpfs works, ext4 does not. 45if ! truncate --size=513T "$TEST_IMG"; then 46 _notrun "file system on $TEST_DIR does not support large enough files" 47fi 48rm "$TEST_IMG" 49IMGOPTS='cluster_size=2M,refcount_bits=1' _make_test_img 513T 50 51echo "== Populating refcounts ==" 52# We want an image with 256M refcounts * 2M clusters = 512T referenced. 53# Each 2M cluster holds 16M refcounts; the refcount table initially uses 54# 1 refblock, so we need to add 15 more. The refcount table lives at 2M, 55# first refblock at 4M, L2 at 6M, so our remaining additions start at 8M. 56# Then, for each refblock, mark it as fully populated. 57to_hex() { 58 printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g' 59} 60truncate --size=38m "$TEST_IMG" 61entry=$((0x200000)) 62$QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io 63for i in {1..15}; do 64 offs=$((0x600000 + i*0x200000)) 65 poke_file "$TEST_IMG" $((i*8 + entry)) $(to_hex $offs) 66 $QEMU_IO_PROG -f raw -c "w -P 0xff $offs 2m" "$TEST_IMG" | _filter_qemu_io 67done 68 69echo "== Checking file before ==" 70# FIXME: 'qemu-img check' doesn't diagnose refcounts beyond the end of 71# the file as leaked clusters 72_check_test_img 2>&1 | sed '/^Leaked cluster/d' 73stat -c 'image size %s' "$TEST_IMG" 74 75echo "== Trying to write compressed cluster ==" 76# Given our file size, the next available cluster at 512T lies beyond the 77# maximum offset that a compressed 2M cluster can reside in 78$QEMU_IO_PROG -c 'w -c 0 2m' "$TEST_IMG" | _filter_qemu_io 79# The attempt failed, but ended up allocating a new refblock 80stat -c 'image size %s' "$TEST_IMG" 81 82echo "== Writing normal cluster ==" 83# The failed write should not corrupt the image, so a normal write succeeds 84$QEMU_IO_PROG -c 'w 0 2m' "$TEST_IMG" | _filter_qemu_io 85 86echo "== Checking file after ==" 87# qemu-img now sees the millions of leaked clusters, thanks to the allocations 88# at 512T. Undo many of our faked references to speed up the check. 89$QEMU_IO_PROG -f raw -c "w -z 5m 1m" -c "w -z 8m 30m" "$TEST_IMG" | 90 _filter_qemu_io 91_check_test_img 2>&1 | sed '/^Leaked cluster/d' 92 93# success, all done 94echo "*** done" 95rm -f $seq.full 96status=0 97