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. 45_require_large_file 513T 46 47IMGOPTS='cluster_size=2M,refcount_bits=1' _make_test_img 513T 48 49echo "== Populating refcounts ==" 50# We want an image with 256M refcounts * 2M clusters = 512T referenced. 51# Each 2M cluster holds 16M refcounts; the refcount table initially uses 52# 1 refblock, so we need to add 15 more. The refcount table lives at 2M, 53# first refblock at 4M, L2 at 6M, so our remaining additions start at 8M. 54# Then, for each refblock, mark it as fully populated. 55to_hex() { 56 printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g' 57} 58truncate --size=38m "$TEST_IMG" 59entry=$((0x200000)) 60$QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io 61for i in {1..15}; do 62 offs=$((0x600000 + i*0x200000)) 63 poke_file "$TEST_IMG" $((i*8 + entry)) $(to_hex $offs) 64 $QEMU_IO_PROG -f raw -c "w -P 0xff $offs 2m" "$TEST_IMG" | _filter_qemu_io 65done 66 67echo "== Checking file before ==" 68# FIXME: 'qemu-img check' doesn't diagnose refcounts beyond the end of 69# the file as leaked clusters 70_check_test_img 2>&1 | sed '/^Leaked cluster/d' 71stat -c 'image size %s' "$TEST_IMG" 72 73echo "== Trying to write compressed cluster ==" 74# Given our file size, the next available cluster at 512T lies beyond the 75# maximum offset that a compressed 2M cluster can reside in 76$QEMU_IO_PROG -c 'w -c 0 2m' "$TEST_IMG" | _filter_qemu_io 77# The attempt failed, but ended up allocating a new refblock 78stat -c 'image size %s' "$TEST_IMG" 79 80echo "== Writing normal cluster ==" 81# The failed write should not corrupt the image, so a normal write succeeds 82$QEMU_IO_PROG -c 'w 0 2m' "$TEST_IMG" | _filter_qemu_io 83 84echo "== Checking file after ==" 85# qemu-img now sees the millions of leaked clusters, thanks to the allocations 86# at 512T. Undo many of our faked references to speed up the check. 87$QEMU_IO_PROG -f raw -c "w -z 5m 1m" -c "w -z 8m 30m" "$TEST_IMG" | 88 _filter_qemu_io 89_check_test_img 2>&1 | sed '/^Leaked cluster/d' 90 91# success, all done 92echo "*** done" 93rm -f $seq.full 94status=0 95