1#!/usr/bin/env bash 2# 3# Test preallocated growth of qcow2 images 4# 5# Copyright (C) 2017 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 21# creator 22owner=mreitz@redhat.com 23 24seq=$(basename $0) 25echo "QA output created by $seq" 26 27status=1 # failure is the default! 28 29_cleanup() 30{ 31 _cleanup_test_img 32} 33trap "_cleanup; exit \$status" 0 1 2 3 15 34 35get_image_size_on_host() 36{ 37 echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE"))) 38} 39 40# get standard environment and filters 41. ./common.rc 42. ./common.filter 43 44_supported_fmt qcow2 45_supported_proto file 46# Growing a file with a backing file (without preallocation=full or 47# =falloc) requires zeroing the newly added area, which is impossible 48# to do quickly for v2 images, and hence is unsupported. 49_unsupported_imgopts 'compat=0.10' 50 51if [ -z "$TEST_IMG_FILE" ]; then 52 TEST_IMG_FILE=$TEST_IMG 53fi 54 55# Test whether we are running on a broken XFS version. There is this 56# bug: 57 58# $ rm -f foo 59# $ touch foo 60# $ block_size=4096 # Your FS's block size 61# $ fallocate -o $((block_size / 2)) -l $block_size foo 62# $ LANG=C xfs_bmap foo | grep hole 63# 1: [8..15]: hole 64# 65# The problem is that the XFS driver rounds down the offset and 66# rounds up the length to the block size, but independently. As 67# such, it only allocates the first block in the example above, 68# even though it should allocate the first two blocks (because our 69# request is to fallocate something that touches both the first 70# two blocks). 71# 72# This means that when you then write to the beginning of the 73# second block, the disk usage of the first two blocks grows. 74# 75# That is precisely what fallocate() promises, though: That when you 76# write to an area that you have fallocated, no new blocks will have 77# to be allocated. 78 79touch "$TEST_IMG_FILE" 80# Assuming there is no FS with a block size greater than 64k 81fallocate -o 65535 -l 2 "$TEST_IMG_FILE" 82len0=$(get_image_size_on_host) 83 84# Write to something that in theory we have just fallocated 85# (Thus, the on-disk size should not increase) 86poke_file "$TEST_IMG_FILE" 65536 42 87len1=$(get_image_size_on_host) 88 89if [ $len1 -gt $len0 ]; then 90 _notrun "the test filesystem's fallocate() is broken" 91fi 92 93rm -f "$TEST_IMG_FILE" 94 95# Generally, we create some image with or without existing preallocation and 96# then resize it. Then we write some data into the image and verify that its 97# size does not change if we have used preallocation. 98 99# With a cluster size of 512 B, one L2 table covers 64 * 512 B = 32 kB. 100# One cluster of the L1 table covers 64 * 32 kB = 2 MB. 101# There are multiple cases we want to test: 102# (1) Grow an image without having to allocate a new L2 table. 103# (2) Grow an image, having to allocate a new L2 table. 104# (3) Grow an image, having to grow the L1 table. 105# Therefore, we create an image that is 48 kB below 2 MB. Then: 106# (1) We resize it to 2 MB - 32 kB. (+ 16 kB) 107# (2) We resize it to 2 MB. (+ 48 kB) 108# (3) We resize it to 2 MB + 32 kB. (+ 80 kB) 109 110# in B 111CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024)) 112 113# 512 is the actual test -- but it's good to test 64k as well, just to be sure. 114for cluster_size in 512 64k; do 115# in kB 116for GROWTH_SIZE in 16 48 80; do 117 for create_mode in off metadata falloc full; do 118 for growth_mode in off metadata falloc full; do 119 echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---" 120 121 _make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE} 122 $QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K 123 124 host_size_0=$(get_image_size_on_host) 125 file_length_0=$(stat -c '%s' "$TEST_IMG_FILE") 126 127 $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io 128 129 host_size_1=$(get_image_size_on_host) 130 file_length_1=$(stat -c '%s' "$TEST_IMG_FILE") 131 132 $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io 133 134 host_size_2=$(get_image_size_on_host) 135 file_length_2=$(stat -c '%s' "$TEST_IMG_FILE") 136 137 # Test creation preallocation: Compare #0 against #1 138 if [ $create_mode != off ]; then 139 # The image length should not have grown 140 if [ $file_length_1 -gt $file_length_0 ]; then 141 echo "ERROR (create): Image length has grown from $file_length_0 to $file_length_1" 142 fi 143 if [ $create_mode != metadata ]; then 144 # The host size should not have grown either 145 if [ $host_size_1 -gt $host_size_0 ]; then 146 echo "ERROR (create): Host size has grown from $host_size_0 to $host_size_1" 147 fi 148 fi 149 fi 150 151 # Test resize preallocation: Compare #2 against #1 152 if [ $growth_mode != off ]; then 153 # The image length should not have grown 154 if [ $file_length_2 -gt $file_length_1 ]; then 155 echo "ERROR (grow): Image length has grown from $file_length_1 to $file_length_2" 156 fi 157 if [ $growth_mode != metadata ]; then 158 # The host size should not have grown either 159 if [ $host_size_2 -gt $host_size_1 ]; then 160 echo "ERROR (grow): Host size has grown from $host_size_1 to $host_size_2" 161 fi 162 fi 163 fi 164 165 echo 166 done 167 done 168done 169done 170 171# Test image resizing using preallocation and unaligned offsets 172$QEMU_IMG create -f raw "$TEST_IMG.base" 128k | _filter_img_create 173$QEMU_IO -c 'write -q -P 1 0 128k' -f raw "$TEST_IMG.base" 174for orig_size in 31k 33k; do 175 for dst_size in 96k 128k; do 176 for prealloc in metadata full; do 177 echo "--- Resizing image from $orig_size to $dst_size (preallocation=$prealloc) ---" 178 _make_test_img -F raw -b "$TEST_IMG.base" -o cluster_size=64k "$orig_size" 179 $QEMU_IMG resize -f "$IMGFMT" --preallocation="$prealloc" "$TEST_IMG" "$dst_size" 180 # The first part of the image should contain data from the backing file 181 $QEMU_IO -c "read -q -P 1 0 ${orig_size}" "$TEST_IMG" 182 # The resized part of the image should contain zeroes 183 $QEMU_IO -c "read -q -P 0 ${orig_size} 63k" "$TEST_IMG" 184 # If the image does not have an external data file we can also verify its 185 # actual size. The resized image should have 7 clusters: 186 # header, L1 table, L2 table, refcount table, refcount block, 2 data clusters 187 if ! _get_data_file "$TEST_IMG" > /dev/null; then 188 expected_file_length=$((65536 * 7)) 189 file_length=$(stat -c '%s' "$TEST_IMG_FILE") 190 if [ "$file_length" != "$expected_file_length" ]; then 191 echo "ERROR: file length $file_length (expected $expected_file_length)" 192 fi 193 fi 194 echo 195 done 196 done 197done 198 199# success, all done 200echo '*** done' 201rm -f $seq.full 202status=0 203