4 # Test preallocated growth of qcow2 images
6 # Copyright (C) 2017 Red Hat, Inc.
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.
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.
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/>.
23 owner=hreitz@redhat.com
26 echo "QA output created by $seq"
28 status=1 # failure is the default!
34 trap "_cleanup; exit \$status" 0 1 2 3 15
36 get_image_size_on_host()
38 echo $(($(stat -c '%b * %B' "$TEST_IMG_FILE")))
41 # get standard environment and filters
47 # Growing a file with a backing file (without preallocation=full or
48 # =falloc) requires zeroing the newly added area, which is impossible
49 # to do quickly for v2 images, and hence is unsupported.
50 _unsupported_imgopts 'compat=0.10'
52 if [ -z "$TEST_IMG_FILE" ]; then
53 TEST_IMG_FILE=$TEST_IMG
56 # Test whether we are running on a broken XFS version. There is this
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
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
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.
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
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=$(get_image_size_on_host)
85 # Write to something that in theory we have just fallocated
86 # (Thus, the on-disk size should not increase)
87 poke_file "$TEST_IMG_FILE" 65536 42
88 len1=$(get_image_size_on_host)
90 if [ $len1 -gt $len0 ]; then
91 _notrun "the test filesystem's fallocate() is broken"
94 rm -f "$TEST_IMG_FILE"
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.
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)
112 CREATION_SIZE=$((2 * 1024 * 1024 - 48 * 1024))
114 # 512 is the actual test -- but it's good to test 64k as well, just to be sure.
115 for cluster_size in 512 64k; do
117 for GROWTH_SIZE in 16 48 80; do
118 for create_mode in off metadata falloc full; do
119 for growth_mode in off metadata falloc full; do
120 echo "--- cluster_size=$cluster_size growth_size=$GROWTH_SIZE create_mode=$create_mode growth_mode=$growth_mode ---"
122 _make_test_img -o "preallocation=$create_mode,cluster_size=$cluster_size" ${CREATION_SIZE}
123 $QEMU_IMG resize -f "$IMGFMT" --preallocation=$growth_mode "$TEST_IMG" +${GROWTH_SIZE}K
125 host_size_0=$(get_image_size_on_host)
126 file_length_0=$(stat -c '%s' "$TEST_IMG_FILE")
128 $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io
130 host_size_1=$(get_image_size_on_host)
131 file_length_1=$(stat -c '%s' "$TEST_IMG_FILE")
133 $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io
135 host_size_2=$(get_image_size_on_host)
136 file_length_2=$(stat -c '%s' "$TEST_IMG_FILE")
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"
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"
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"
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"
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)"