1#!/usr/bin/env bash 2# group: rw backing quick 3# 4# Test large write to a qcow2 image 5# 6# Copyright (C) 2019 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 $seq" 24 25status=1 # failure is the default! 26 27_cleanup() 28{ 29 _cleanup_test_img 30} 31trap "_cleanup; exit \$status" 0 1 2 3 15 32 33# get standard environment, filters and checks 34. ./common.rc 35. ./common.filter 36 37# This is a qcow2 regression test 38_supported_fmt qcow2 39_supported_proto file 40_supported_os Linux 41 42# We use our own external data file and our own cluster size, and we 43# require v3 images 44_unsupported_imgopts data_file cluster_size 'compat=0.10' 45 46 47# We need a backing file so that handle_alloc_space() will not do 48# anything. (If it were to do anything, it would simply fail its 49# write-zeroes request because the request range is too large.) 50TEST_IMG="$TEST_IMG.base" _make_test_img 4G 51$QEMU_IO -c 'write 0 512' "$TEST_IMG.base" | _filter_qemu_io 52 53# (Use .orig because _cleanup_test_img will remove that file) 54# We need a large cluster size, see below for why (above the $QEMU_IO 55# invocation) 56_make_test_img -o cluster_size=2M,data_file="$TEST_IMG.orig" \ 57 -b "$TEST_IMG.base" -F $IMGFMT 4G 58 59# We want a null-co as the data file, because it allows us to quickly 60# "write" 2G of data without using any space. 61# (qemu-img create does not like it, though, because null-co does not 62# support image creation.) 63$QEMU_IMG amend -o data_file="json:{'driver':'null-co',,'size':'4294967296'}" \ 64 "$TEST_IMG" 65 66# This gives us a range of: 67# 2^31 - 512 + 768 - 1 = 2^31 + 255 > 2^31 68# until the beginning of the end COW block. (The total allocation 69# size depends on the cluster size, but all that is important is that 70# it exceeds INT_MAX.) 71# 72# 2^31 - 512 is the maximum request size. We want this to result in a 73# single allocation, and because the qcow2 driver splits allocations 74# on L2 boundaries, we need large L2 tables; hence the cluster size of 75# 2 MB. (Anything from 256 kB should work, though, because then one L2 76# table covers 8 GB.) 77$QEMU_IO -c "write 768 $((2 ** 31 - 512))" "$TEST_IMG" | _filter_qemu_io 78 79_check_test_img 80 81# success, all done 82echo "*** done" 83rm -f $seq.full 84status=0 85