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 22 seq=$(basename "$0") 23 echo "QA output created by $seq" 24 25 status=1 # failure is the default! 26 27 _cleanup() 28 { 29 _cleanup_test_img 30 } 31 trap "_cleanup; exit \$status" 0 1 2 3 15 32 33 # get standard environment, filters and checks 34 . ./common.rc 35 . ./common.filter 36 37 # This is a qcow2 regression test 38 _supported_fmt qcow2 39 _supported_proto file 40 _supported_os Linux 41 42 # We use our own external data file and our own cluster size, and we 43 # require v3 images 44 _unsupported_imgopts data_file cluster_size 'compat=0.10' 45 46 47 # We need a backing file so that handle_alloc_space() will not do 48 # anything. (If it were to do anything, it would simply fail its 49 # write-zeroes request because the request range is too large.) 50 TEST_IMG="$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 $IMGFMT 4G 58 59 # We want a null-co as the data file, because it allows us to quickly 60 # "write" 2G of data without using any space. 61 # (qemu-img create does not like it, though, because null-co does not 62 # support image creation.) 63 test_img_with_null_data="json:{ 64 'driver': '$IMGFMT', 65 'file': { 66 'filename': '$TEST_IMG' 67 }, 68 'data-file': { 69 'driver': 'null-co', 70 'size':'4294967296' 71 } 72 }" 73 74 # This gives us a range of: 75 # 2^31 - 512 + 768 - 1 = 2^31 + 255 > 2^31 76 # until the beginning of the end COW block. (The total allocation 77 # size depends on the cluster size, but all that is important is that 78 # it exceeds INT_MAX.) 79 # 80 # 2^31 - 512 is the maximum request size. We want this to result in a 81 # single allocation, and because the qcow2 driver splits allocations 82 # on L2 boundaries, we need large L2 tables; hence the cluster size of 83 # 2 MB. (Anything from 256 kB should work, though, because then one L2 84 # table covers 8 GB.) 85 $QEMU_IO -c "write 768 $((2 ** 31 - 512))" "$test_img_with_null_data" | _filter_qemu_io 86 87 _check_test_img 88 89 # success, all done 90 echo "*** done" 91 rm -f $seq.full 92 status=0 93