qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
Log | Files | Refs | Submodules | LICENSE

154 (19006B)


      1 #!/usr/bin/env bash
      2 # group: rw auto backing quick
      3 #
      4 # qcow2 specific bdrv_pwrite_zeroes tests with backing files (complements 034)
      5 #
      6 # Copyright (C) 2016-2017 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=kwolf@redhat.com
     24 
     25 seq=`basename $0`
     26 echo "QA output created by $seq"
     27 
     28 status=1	# failure is the default!
     29 
     30 _cleanup()
     31 {
     32 	_cleanup_test_img
     33 }
     34 trap "_cleanup; exit \$status" 0 1 2 3 15
     35 
     36 # get standard environment, filters and checks
     37 . ./common.rc
     38 . ./common.filter
     39 
     40 _supported_fmt qcow2
     41 _supported_proto file fuse
     42 _supported_os Linux
     43 
     44 CLUSTER_SIZE=4k
     45 size=$((128 * 1024 * 1024))
     46 
     47 # This test requires zero clusters, added in v3 images
     48 _unsupported_imgopts compat=0.10
     49 
     50 echo
     51 echo == backing file contains zeros ==
     52 
     53 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
     54 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
     55 
     56 # Make sure that the whole cluster is allocated even for partial write_zeroes
     57 # when the backing file contains zeros
     58 
     59 # X = non-zero data sector in backing file
     60 # - = sector unallocated in whole backing chain
     61 # 0 = sector touched by write_zeroes request
     62 
     63 # 1. Tail unaligned:    00 00 -- --
     64 # 2. Head unaligned:    -- -- 00 00
     65 # 3. Both unaligned:    -- 00 00 --
     66 # 4. Both, 2 clusters:  -- -- -- 00 | 00 -- -- --
     67 
     68 $QEMU_IO -c "write -z 0 2k" "$TEST_IMG" | _filter_qemu_io
     69 $QEMU_IO -c "write -z 10k 2k" "$TEST_IMG" | _filter_qemu_io
     70 $QEMU_IO -c "write -z 17k 2k" "$TEST_IMG" | _filter_qemu_io
     71 $QEMU_IO -c "write -z 27k 2k" "$TEST_IMG" | _filter_qemu_io
     72 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
     73 
     74 echo
     75 echo == backing file contains non-zero data before write_zeroes ==
     76 
     77 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
     78 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
     79 
     80 # Single cluster; non-zero data at the cluster start
     81 # ... | XX -- 00 -- | ...
     82 $QEMU_IO -c "write -P 0x11 32k 1k" "$TEST_IMG.base" | _filter_qemu_io
     83 $QEMU_IO -c "write -z 34k 1k" "$TEST_IMG" | _filter_qemu_io
     84 $QEMU_IO -c "read -P 0x11 32k 1k" "$TEST_IMG" | _filter_qemu_io
     85 $QEMU_IO -c "read -P 0 33k 3k" "$TEST_IMG" | _filter_qemu_io
     86 
     87 # Single cluster; non-zero data exists, but not at the cluster start
     88 # ... | -- XX 00 -- | ...
     89 $QEMU_IO -c "write -P 0x11 65k 1k" "$TEST_IMG.base" | _filter_qemu_io
     90 $QEMU_IO -c "write -z 66k 1k" "$TEST_IMG" | _filter_qemu_io
     91 $QEMU_IO -c "read -P 0x11 65k 1k" "$TEST_IMG" | _filter_qemu_io
     92 $QEMU_IO -c "read -P 0 64k 1k" "$TEST_IMG" | _filter_qemu_io
     93 $QEMU_IO -c "read -P 0 66k 2k" "$TEST_IMG" | _filter_qemu_io
     94 
     95 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
     96 
     97 echo
     98 echo == backing file contains non-zero data after write_zeroes ==
     99 
    100 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    101 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    102 
    103 # Single cluster; non-zero data directly after request
    104 # ... | -- 00 XX -- | ...
    105 $QEMU_IO -c "write -P 0x11 34k 1k" "$TEST_IMG.base" | _filter_qemu_io
    106 $QEMU_IO -c "write -z 33k 1k" "$TEST_IMG" | _filter_qemu_io
    107 $QEMU_IO -c "read -P 0 32k 2k" "$TEST_IMG" | _filter_qemu_io
    108 $QEMU_IO -c "read -P 0x11 34k 1k" "$TEST_IMG" | _filter_qemu_io
    109 $QEMU_IO -c "read -P 0 35k 1k" "$TEST_IMG" | _filter_qemu_io
    110 
    111 # Single cluster; non-zero data exists, but not directly after request
    112 # ... | -- 00 -- XX | ...
    113 $QEMU_IO -c "write -P 0x11 43k 1k" "$TEST_IMG.base" | _filter_qemu_io
    114 $QEMU_IO -c "write -z 41k 1k" "$TEST_IMG" | _filter_qemu_io
    115 $QEMU_IO -c "read -P 0x11 43k 1k" "$TEST_IMG" | _filter_qemu_io
    116 $QEMU_IO -c "read -P 0 40k 3k" "$TEST_IMG" | _filter_qemu_io
    117 
    118 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    119 
    120 echo
    121 echo == write_zeroes covers non-zero data ==
    122 
    123 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    124 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    125 
    126 # non-zero data at front of request
    127 # Backing file: -- XX -- --
    128 # Active layer: -- 00 00 --
    129 
    130 $QEMU_IO -c "write -P 0x11 5k 1k" "$TEST_IMG.base" | _filter_qemu_io
    131 $QEMU_IO -c "write -z 5k 2k" "$TEST_IMG" | _filter_qemu_io
    132 $QEMU_IO -c "read -P 0 4k 4k" "$TEST_IMG" | _filter_qemu_io
    133 
    134 # non-zero data at end of request
    135 # Backing file: -- -- XX --
    136 # Active layer: -- 00 00 --
    137 
    138 $QEMU_IO -c "write -P 0x11 14k 1k" "$TEST_IMG.base" | _filter_qemu_io
    139 $QEMU_IO -c "write -z 13k 2k" "$TEST_IMG" | _filter_qemu_io
    140 $QEMU_IO -c "read -P 0 12k 4k" "$TEST_IMG" | _filter_qemu_io
    141 
    142 # non-zero data matches size of request
    143 # Backing file: -- XX XX --
    144 # Active layer: -- 00 00 --
    145 
    146 $QEMU_IO -c "write -P 0x11 21k 2k" "$TEST_IMG.base" | _filter_qemu_io
    147 $QEMU_IO -c "write -z 21k 2k" "$TEST_IMG" | _filter_qemu_io
    148 $QEMU_IO -c "read -P 0 20k 4k" "$TEST_IMG" | _filter_qemu_io
    149 
    150 # non-zero data smaller than request
    151 # Backing file: -- -X X- --
    152 # Active layer: -- 00 00 --
    153 
    154 $QEMU_IO -c "write -P 0x11 30208 1k" "$TEST_IMG.base" | _filter_qemu_io
    155 $QEMU_IO -c "write -z 29k 2k" "$TEST_IMG" | _filter_qemu_io
    156 $QEMU_IO -c "read -P 0 28k 4k" "$TEST_IMG" | _filter_qemu_io
    157 
    158 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    159 
    160 echo
    161 echo == spanning two clusters, non-zero before request ==
    162 
    163 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    164 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    165 
    166 # Two clusters; non-zero data before request:
    167 # 1. At cluster start:          32k: XX -- -- 00 | 00 -- -- --
    168 # 2. Between unallocated space: 48k: -- XX -- 00 | 00 -- -- --
    169 # 3. Directly before request:   64k: -- -- XX 00 | 00 -- -- --
    170 
    171 $QEMU_IO -c "write -P 0x11 32k 1k" "$TEST_IMG.base" | _filter_qemu_io
    172 $QEMU_IO -c "write -z 35k 2k" "$TEST_IMG" | _filter_qemu_io
    173 $QEMU_IO -c "read -P 0x11 32k 1k" "$TEST_IMG" | _filter_qemu_io
    174 $QEMU_IO -c "read -P 0 33k 7k" "$TEST_IMG" | _filter_qemu_io
    175 
    176 $QEMU_IO -c "write -P 0x11 49k 1k" "$TEST_IMG.base" | _filter_qemu_io
    177 $QEMU_IO -c "write -z 51k 2k" "$TEST_IMG" | _filter_qemu_io
    178 $QEMU_IO -c "read -P 0 48k 1k" "$TEST_IMG" | _filter_qemu_io
    179 $QEMU_IO -c "read -P 0x11 49k 1k" "$TEST_IMG" | _filter_qemu_io
    180 $QEMU_IO -c "read -P 0 50k 6k" "$TEST_IMG" | _filter_qemu_io
    181 
    182 $QEMU_IO -c "write -P 0x11 66k 1k" "$TEST_IMG.base" | _filter_qemu_io
    183 $QEMU_IO -c "write -z 67k 2k" "$TEST_IMG" | _filter_qemu_io
    184 $QEMU_IO -c "read -P 0 64k 2k" "$TEST_IMG" | _filter_qemu_io
    185 $QEMU_IO -c "read -P 0x11 66k 1k" "$TEST_IMG" | _filter_qemu_io
    186 $QEMU_IO -c "read -P 0 67k 5k" "$TEST_IMG" | _filter_qemu_io
    187 
    188 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    189 
    190 echo
    191 echo == spanning two clusters, non-zero after request ==
    192 
    193 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    194 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    195 
    196 # Two clusters; non-zero data after request:
    197 # 1. Directly after request:    32k: -- -- -- 00 | 00 XX -- --
    198 # 2. Between unallocated space: 48k: -- -- -- 00 | 00 -- XX --
    199 # 3. At cluster end:            64k: -- -- -- 00 | 00 -- -- XX
    200 
    201 $QEMU_IO -c "write -P 0x11 37k 1k" "$TEST_IMG.base" | _filter_qemu_io
    202 $QEMU_IO -c "write -z 35k 2k" "$TEST_IMG" | _filter_qemu_io
    203 $QEMU_IO -c "read -P 0 32k 5k" "$TEST_IMG" | _filter_qemu_io
    204 $QEMU_IO -c "read -P 0x11 37k 1k" "$TEST_IMG" | _filter_qemu_io
    205 $QEMU_IO -c "read -P 0 38k 2k" "$TEST_IMG" | _filter_qemu_io
    206 
    207 $QEMU_IO -c "write -P 0x11 54k 1k" "$TEST_IMG.base" | _filter_qemu_io
    208 $QEMU_IO -c "write -z 51k 2k" "$TEST_IMG" | _filter_qemu_io
    209 $QEMU_IO -c "read -P 0 48k 6k" "$TEST_IMG" | _filter_qemu_io
    210 $QEMU_IO -c "read -P 0x11 54k 1k" "$TEST_IMG" | _filter_qemu_io
    211 $QEMU_IO -c "read -P 0 55k 1k" "$TEST_IMG" | _filter_qemu_io
    212 
    213 $QEMU_IO -c "write -P 0x11 71k 1k" "$TEST_IMG.base" | _filter_qemu_io
    214 $QEMU_IO -c "write -z 67k 2k" "$TEST_IMG" | _filter_qemu_io
    215 $QEMU_IO -c "read -P 0 64k 7k" "$TEST_IMG" | _filter_qemu_io
    216 $QEMU_IO -c "read -P 0x11 71k 1k" "$TEST_IMG" | _filter_qemu_io
    217 
    218 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    219 
    220 echo
    221 echo == spanning two clusters, partially overwriting backing file ==
    222 
    223 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    224 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    225 
    226 # Backing file: -- -- XX XX | XX XX -- --
    227 # Active layer: -- -- XX 00 | 00 XX -- --
    228 
    229 $QEMU_IO -c "write -P 0x11 2k 4k" "$TEST_IMG.base" | _filter_qemu_io
    230 $QEMU_IO -c "write -z 3k 2k" "$TEST_IMG" | _filter_qemu_io
    231 $QEMU_IO -c "read -P 0 0k 2k" "$TEST_IMG" | _filter_qemu_io
    232 $QEMU_IO -c "read -P 0x11 2k 1k" "$TEST_IMG" | _filter_qemu_io
    233 $QEMU_IO -c "read -P 0 3k 2k" "$TEST_IMG" | _filter_qemu_io
    234 $QEMU_IO -c "read -P 0x11 5k 1k" "$TEST_IMG" | _filter_qemu_io
    235 $QEMU_IO -c "read -P 0 6k 2k" "$TEST_IMG" | _filter_qemu_io
    236 
    237 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    238 
    239 echo
    240 echo == spanning multiple clusters, non-zero in first cluster ==
    241 
    242 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    243 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    244 
    245 # Backing file: 64k: XX XX -- -- | -- -- -- -- | -- -- -- --
    246 # Active layer: 64k: XX XX 00 00 | 00 00 00 00 | 00 -- -- --
    247 
    248 $QEMU_IO -c "write -P 0x11 64k 2k" "$TEST_IMG.base" | _filter_qemu_io
    249 $QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
    250 $QEMU_IO -c "read -P 0x11 64k 2k" "$TEST_IMG" | _filter_qemu_io
    251 $QEMU_IO -c "read -P 0 66k 10k" "$TEST_IMG" | _filter_qemu_io
    252 
    253 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    254 
    255 echo
    256 echo == spanning multiple clusters, non-zero in intermediate cluster ==
    257 
    258 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    259 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    260 
    261 # Backing file: 64k: -- -- -- -- | -- XX XX -- | -- -- -- --
    262 # Active layer: 64k: -- -- 00 00 | 00 00 00 00 | 00 -- -- --
    263 
    264 $QEMU_IO -c "write -P 0x11 69k 2k" "$TEST_IMG.base" | _filter_qemu_io
    265 $QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
    266 $QEMU_IO -c "read -P 0 64k 12k" "$TEST_IMG" | _filter_qemu_io
    267 
    268 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    269 
    270 echo
    271 echo == spanning multiple clusters, non-zero in final cluster ==
    272 
    273 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    274 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    275 
    276 # Backing file: 64k: -- -- -- -- | -- -- -- -- | -- -- XX XX
    277 # Active layer: 64k: -- -- 00 00 | 00 00 00 00 | 00 -- XX XX
    278 
    279 $QEMU_IO -c "write -P 0x11 74k 2k" "$TEST_IMG.base" | _filter_qemu_io
    280 $QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
    281 $QEMU_IO -c "read -P 0 64k 10k" "$TEST_IMG" | _filter_qemu_io
    282 $QEMU_IO -c "read -P 0x11 74k 2k" "$TEST_IMG" | _filter_qemu_io
    283 
    284 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    285 
    286 echo
    287 echo == spanning multiple clusters, partially overwriting backing file ==
    288 
    289 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
    290 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
    291 
    292 # Backing file: 64k: -- XX XX XX | XX XX XX XX | XX XX XX --
    293 # Active layer: 64k: -- XX 00 00 | 00 00 00 00 | 00 XX XX --
    294 
    295 $QEMU_IO -c "write -P 0x11 65k 10k" "$TEST_IMG.base" | _filter_qemu_io
    296 $QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
    297 $QEMU_IO -c "read -P 0 64k 1k" "$TEST_IMG" | _filter_qemu_io
    298 $QEMU_IO -c "read -P 0x11 65k 1k" "$TEST_IMG" | _filter_qemu_io
    299 $QEMU_IO -c "read -P 0 66k 7k" "$TEST_IMG" | _filter_qemu_io
    300 $QEMU_IO -c "read -P 0x11 73k 2k" "$TEST_IMG" | _filter_qemu_io
    301 $QEMU_IO -c "read -P 0 75k 1k" "$TEST_IMG" | _filter_qemu_io
    302 
    303 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    304 
    305 echo
    306 echo == unaligned image tail cluster, no allocation needed ==
    307 
    308 # With no backing file, write to all or part of unallocated partial cluster
    309 # will mark the cluster as zero, but does not allocate.
    310 # Re-create the image each time to get back to unallocated clusters.
    311 
    312 # Write at the front: sector-wise, the request is: 128m... | 00 -- -- --
    313 _make_test_img $((size + 2048))
    314 $QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
    315 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    316 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    317 
    318 # Write at the back: sector-wise, the request is: 128m... | -- -- -- 00
    319 _make_test_img $((size + 2048))
    320 $QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
    321 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    322 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    323 
    324 # Write at middle: sector-wise, the request is: 128m... | -- 00 00 --
    325 _make_test_img $((size + 2048))
    326 $QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
    327 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    328 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    329 
    330 # Write entire cluster: sector-wise, the request is: 128m... | 00 00 00 00
    331 _make_test_img $((size + 2048))
    332 $QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
    333 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    334 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    335 
    336 # Repeat with backing file holding unallocated cluster.
    337 CLUSTER_SIZE=2048 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
    338 
    339 # Write at the front: sector-wise, the request is:
    340 # backing: 128m... | -- --
    341 # active:  128m... | 00 -- -- --
    342 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    343 $QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
    344 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    345 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    346 
    347 # Write at the back: sector-wise, the request is:
    348 # backing: 128m... | -- --
    349 # active:  128m... | -- -- -- 00
    350 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    351 $QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
    352 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    353 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    354 
    355 # Write at middle: sector-wise, the request is:
    356 # backing: 128m... | -- --
    357 # active:  128m... | -- 00 00 --
    358 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    359 $QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
    360 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    361 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    362 
    363 # Write entire cluster: sector-wise, the request is:
    364 # backing: 128m... | -- --
    365 # active:  128m... | 00 00 00 00
    366 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    367 $QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
    368 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    369 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    370 
    371 # Repeat with backing file holding zero'd cluster
    372 $QEMU_IO -c "write -z $size 512" "$TEST_IMG.base" | _filter_qemu_io
    373 
    374 # Write at the front: sector-wise, the request is:
    375 # backing: 128m... | 00 00
    376 # active:  128m... | 00 -- -- --
    377 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    378 $QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
    379 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    380 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    381 
    382 # Write at the back: sector-wise, the request is:
    383 # backing: 128m... | 00 00
    384 # active:  128m... | -- -- -- 00
    385 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    386 $QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
    387 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    388 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    389 
    390 # Write at middle: sector-wise, the request is:
    391 # backing: 128m... | 00 00
    392 # active:  128m... | -- 00 00 --
    393 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    394 $QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
    395 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    396 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    397 
    398 # Write entire cluster: sector-wise, the request is:
    399 # backing: 128m... | 00 00
    400 # active:  128m... | 00 00 00 00
    401 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    402 $QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
    403 $QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
    404 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    405 
    406 # A preallocated cluster maintains its allocation, whether it stays as
    407 # data due to a partial write:
    408 # Convert 128m... | XX XX => ... | XX 00
    409 _make_test_img $((size + 1024))
    410 $QEMU_IO -c "write -P 1 $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
    411 $QEMU_IO -c "write -z $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
    412 $QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
    413 $QEMU_IO -c "read -P 0 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
    414 $QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
    415 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    416 
    417 # or because it is the entire cluster and can use the zero flag:
    418 # Convert 128m... | XX XX => ... | 00 00
    419 $QEMU_IO -c "write -z $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
    420 $QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
    421 $QEMU_IO -c "read -P 0 $size 1024" "$TEST_IMG" | _filter_qemu_io
    422 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    423 
    424 echo
    425 echo == unaligned image tail cluster, allocation required ==
    426 
    427 # Write beyond backing file must COW
    428 # Backing file: 128m... | XX --
    429 # Active layer: 128m... | -- -- 00 --
    430 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
    431 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    432 $QEMU_IO -c "write -P 1 $((size)) 512" "$TEST_IMG.base" | _filter_qemu_io
    433 $QEMU_IO -c "write -z $((size + 1024)) 512" "$TEST_IMG" | _filter_qemu_io
    434 $QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
    435 $QEMU_IO -c "read -P 0 $((size + 512)) 1536" "$TEST_IMG" | _filter_qemu_io
    436 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    437 
    438 # Writes at boundaries of (partial) cluster must not lose mid-cluster data
    439 # Backing file: 128m: ... | -- XX
    440 # Active layer: 128m: ... | 00 -- -- 00
    441 CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
    442 _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $((size + 2048))
    443 $QEMU_IO -c "write -P 1 $((size + 512)) 512" "$TEST_IMG.base" | _filter_qemu_io
    444 $QEMU_IO -c "write -z $((size)) 512" "$TEST_IMG" | _filter_qemu_io
    445 $QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
    446 $QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
    447 $QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
    448 $QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
    449 $QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
    450 $QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
    451 $QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
    452 $QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
    453 
    454 # success, all done
    455 echo "*** done"
    456 rm -f $seq.full
    457 status=0