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