1#!/usr/bin/env bash 2# 3# Test large write to a qcow2 image 4# 5# Copyright (C) 2019 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 $seq" 23 24status=1 # failure is the default! 25 26_cleanup() 27{ 28 _cleanup_test_img 29} 30trap "_cleanup; exit \$status" 0 1 2 3 15 31 32# get standard environment, filters and checks 33. ./common.rc 34. ./common.filter 35 36# This is a qcow2 regression test 37_supported_fmt qcow2 38_supported_proto file 39_supported_os Linux 40 41# We use our own external data file and our own cluster size, and we 42# require v3 images 43_unsupported_imgopts data_file cluster_size 'compat=0.10' 44 45 46# We need a backing file so that handle_alloc_space() will not do 47# anything. (If it were to do anything, it would simply fail its 48# write-zeroes request because the request range is too large.) 49TEST_IMG="$TEST_IMG.base" _make_test_img 4G 50$QEMU_IO -c 'write 0 512' "$TEST_IMG.base" | _filter_qemu_io 51 52# (Use .orig because _cleanup_test_img will remove that file) 53# We need a large cluster size, see below for why (above the $QEMU_IO 54# invocation) 55_make_test_img -o cluster_size=2M,data_file="$TEST_IMG.orig" \ 56 -b "$TEST_IMG.base" 4G 57 58# We want a null-co as the data file, because it allows us to quickly 59# "write" 2G of data without using any space. 60# (qemu-img create does not like it, though, because null-co does not 61# support image creation.) 62$QEMU_IMG amend -o data_file="json:{'driver':'null-co',,'size':'4294967296'}" \ 63 "$TEST_IMG" 64 65# This gives us a range of: 66# 2^31 - 512 + 768 - 1 = 2^31 + 255 > 2^31 67# until the beginning of the end COW block. (The total allocation 68# size depends on the cluster size, but all that is important is that 69# it exceeds INT_MAX.) 70# 71# 2^31 - 512 is the maximum request size. We want this to result in a 72# single allocation, and because the qcow2 driver splits allocations 73# on L2 boundaries, we need large L2 tables; hence the cluster size of 74# 2 MB. (Anything from 256 kB should work, though, because then one L2 75# table covers 8 GB.) 76$QEMU_IO -c "write 768 $((2 ** 31 - 512))" "$TEST_IMG" | _filter_qemu_io 77 78_check_test_img 79 80# success, all done 81echo "*** done" 82rm -f $seq.full 83status=0 84