tests/qemu-iotests/125

   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