3 # Test preallocated growth of qcow2 images
5 # Copyright (C) 2017 Red Hat, Inc.
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.
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.
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/>.
22 owner
=mreitz@redhat.com
25 echo "QA output created by $seq"
27 status
=1 # failure is the default!
33 trap "_cleanup; exit \$status" 0 1 2 3 15
35 get_image_size_on_host
()
37 echo $
(($
(stat
-c '%b * %B' "$TEST_IMG_FILE")))
40 # get standard environment and filters
46 # Growing a file with a backing file (without preallocation=full or
47 # =falloc) requires zeroing the newly added area, which is impossible
48 # to do quickly for v2 images, and hence is unsupported.
49 _unsupported_imgopts
'compat=0.10'
51 if [ -z "$TEST_IMG_FILE" ]; then
52 TEST_IMG_FILE
=$TEST_IMG
55 # Test whether we are running on a broken XFS version. There is this
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
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
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.
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
79 touch "$TEST_IMG_FILE"
80 # Assuming there is no FS with a block size greater than 64k
81 fallocate
-o 65535 -l 2 "$TEST_IMG_FILE"
82 len0
=$
(get_image_size_on_host
)
84 # Write to something that in theory we have just fallocated
85 # (Thus, the on-disk size should not increase)
86 poke_file
"$TEST_IMG_FILE" 65536 42
87 len1
=$
(get_image_size_on_host
)
89 if [ $len1 -gt $len0 ]; then
90 _notrun
"the test filesystem's fallocate() is broken"
93 rm -f "$TEST_IMG_FILE"
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.
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)
111 CREATION_SIZE
=$
((2 * 1024 * 1024 - 48 * 1024))
113 # 512 is the actual test -- but it's good to test 64k as well, just to be sure.
114 for cluster_size
in 512 64k
; do
116 for 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 ---"
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" +${GROWTH_SIZE}K
124 host_size_0
=$
(get_image_size_on_host
)
125 file_length_0
=$
(stat
-c '%s' "$TEST_IMG_FILE")
127 $QEMU_IO -c "write 0 $CREATION_SIZE" "$TEST_IMG" | _filter_qemu_io
129 host_size_1
=$
(get_image_size_on_host
)
130 file_length_1
=$
(stat
-c '%s' "$TEST_IMG_FILE")
132 $QEMU_IO -c "write $CREATION_SIZE ${GROWTH_SIZE}K" "$TEST_IMG" | _filter_qemu_io
134 host_size_2
=$
(get_image_size_on_host
)
135 file_length_2
=$
(stat
-c '%s' "$TEST_IMG_FILE")
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"
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"
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"
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"
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"
174 for 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)"