125 (7706B)
1 #!/usr/bin/env bash 2 # group: rw 3 # 4 # Test preallocated growth of qcow2 images 5 # 6 # Copyright (C) 2017 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 # creator 23 owner=hreitz@redhat.com 24 25 seq=$(basename $0) 26 echo "QA output created by $seq" 27 28 status=1 # failure is the default! 29 30 _cleanup() 31 { 32 _cleanup_test_img 33 } 34 trap "_cleanup; exit \$status" 0 1 2 3 15 35 36 get_image_size_on_host() 37 { 38 echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE"))) 39 } 40 41 # get standard environment and filters 42 . ./common.rc 43 . ./common.filter 44 45 _supported_fmt qcow2 46 _supported_proto file 47 # Growing a file with a backing file (without preallocation=full or 48 # =falloc) requires zeroing the newly added area, which is impossible 49 # to do quickly for v2 images, and hence is unsupported. 50 _unsupported_imgopts 'compat=0.10' 51 52 if [ -z "$TEST_IMG_FILE" ]; then 53 TEST_IMG_FILE=$TEST_IMG 54 fi 55 56 # Test whether we are running on a broken XFS version. There is this 57 # bug: 58 59 # $ rm -f foo 60 # $ touch foo 61 # $ block_size=4096 # Your FS's block size 62 # $ fallocate -o $((block_size / 2)) -l $block_size foo 63 # $ LANG=C xfs_bmap foo | grep hole 64 # 1: [8..15]: hole 65 # 66 # The problem is that the XFS driver rounds down the offset and 67 # rounds up the length to the block size, but independently. As 68 # such, it only allocates the first block in the example above, 69 # even though it should allocate the first two blocks (because our 70 # request is to fallocate something that touches both the first 71 # two blocks). 72 # 73 # This means that when you then write to the beginning of the 74 # second block, the disk usage of the first two blocks grows. 75 # 76 # That is precisely what fallocate() promises, though: That when you 77 # write to an area that you have fallocated, no new blocks will have 78 # to be allocated. 79 80 touch "$TEST_IMG_FILE" 81 # Assuming there is no FS with a block size greater than 64k 82 fallocate -o 65535 -l 2 "$TEST_IMG_FILE" 83 len0=$(get_image_size_on_host) 84 85 # Write to something that in theory we have just fallocated 86 # (Thus, the on-disk size should not increase) 87 poke_file "$TEST_IMG_FILE" 65536 42 88 len1=$(get_image_size_on_host) 89 90 if [ $len1 -gt $len0 ]; then 91 _notrun "the test filesystem's fallocate() is broken" 92 fi 93 94 rm -f "$TEST_IMG_FILE" 95 96 # Generally, we create some image with or without existing preallocation and 97 # then resize it. Then we write some data into the image and verify that its 98 # size does not change if we have used preallocation. 99 100 # With a cluster size of 512 B, one L2 table covers 64 * 512 B = 32 kB. 101 # One cluster of the L1 table covers 64 * 32 kB = 2 MB. 102 # There are multiple cases we want to test: 103 # (1) Grow an image without having to allocate a new L2 table. 104 # (2) Grow an image, having to allocate a new L2 table. 105 # (3) Grow an image, having to grow the L1 table. 106 # Therefore, we create an image that is 48 kB below 2 MB. Then: 107 # (1) We resize it to 2 MB - 32 kB. (+ 16 kB) 108 # (2) We resize it to 2 MB. (+ 48 kB) 109 # (3) We resize it to 2 MB + 32 kB. (+ 80 kB) 110 111 # in B 112 CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024)) 113 114 # 512 is the actual test -- but it's good to test 64k as well, just to be sure. 115 for cluster_size in 512 64k; do 116 # in kB 117 for GROWTH_SIZE in 16 48 80; do 118 for create_mode in off metadata falloc full; do 119 for growth_mode in off metadata falloc full; do 120 echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---" 121 122 _make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE} 123 $QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K 124 125 host_size_0=$(get_image_size_on_host) 126 file_length_0=$(stat -c '%s' "$TEST_IMG_FILE") 127 128 $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io 129 130 host_size_1=$(get_image_size_on_host) 131 file_length_1=$(stat -c '%s' "$TEST_IMG_FILE") 132 133 $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io 134 135 host_size_2=$(get_image_size_on_host) 136 file_length_2=$(stat -c '%s' "$TEST_IMG_FILE") 137 138 # Test creation preallocation: Compare #0 against #1 139 if [ $create_mode != off ]; then 140 # The image length should not have grown 141 if [ $file_length_1 -gt $file_length_0 ]; then 142 echo "ERROR (create): Image length has grown from $file_length_0 to $file_length_1" 143 fi 144 if [ $create_mode != metadata ]; then 145 # The host size should not have grown either 146 if [ $host_size_1 -gt $host_size_0 ]; then 147 echo "ERROR (create): Host size has grown from $host_size_0 to $host_size_1" 148 fi 149 fi 150 fi 151 152 # Test resize preallocation: Compare #2 against #1 153 if [ $growth_mode != off ]; then 154 # The image length should not have grown 155 if [ $file_length_2 -gt $file_length_1 ]; then 156 echo "ERROR (grow): Image length has grown from $file_length_1 to $file_length_2" 157 fi 158 if [ $growth_mode != metadata ]; then 159 # The host size should not have grown either 160 if [ $host_size_2 -gt $host_size_1 ]; then 161 echo "ERROR (grow): Host size has grown from $host_size_1 to $host_size_2" 162 fi 163 fi 164 fi 165 166 echo 167 done 168 done 169 done 170 done 171 172 # Test image resizing using preallocation and unaligned offsets 173 $QEMU_IMG create -f raw "$TEST_IMG.base" 128k | _filter_img_create 174 $QEMU_IO -c 'write -q -P 1 0 128k' -f raw "$TEST_IMG.base" 175 for orig_size in 31k 33k; do 176 for dst_size in 96k 128k; do 177 for prealloc in metadata full; do 178 echo "--- Resizing image from $orig_size to $dst_size (preallocation=$prealloc) ---" 179 _make_test_img -F raw -b "$TEST_IMG.base" -o cluster_size=64k "$orig_size" 180 $QEMU_IMG resize -f "$IMGFMT" --preallocation="$prealloc" "$TEST_IMG" "$dst_size" 181 # The first part of the image should contain data from the backing file 182 $QEMU_IO -c "read -q -P 1 0 ${orig_size}" "$TEST_IMG" 183 # The resized part of the image should contain zeroes 184 $QEMU_IO -c "read -q -P 0 ${orig_size} 63k" "$TEST_IMG" 185 # If the image does not have an external data file we can also verify its 186 # actual size. The resized image should have 7 clusters: 187 # header, L1 table, L2 table, refcount table, refcount block, 2 data clusters 188 if ! _get_data_file "$TEST_IMG" > /dev/null; then 189 expected_file_length=$((65536 * 7)) 190 file_length=$(stat -c '%s' "$TEST_IMG_FILE") 191 if [ "$file_length" != "$expected_file_length" ]; then 192 echo "ERROR: file length $file_length (expected $expected_file_length)" 193 fi 194 fi 195 echo 196 done 197 done 198 done 199 200 # success, all done 201 echo '*** done' 202 rm -f $seq.full 203 status=0