tests/qemu-iotests/270

   1 #!/usr/bin/env bash
   2 # group: rw backing quick
   3 #
   4 # Test large write to a qcow2 image
   5 #
   6 # Copyright (C) 2019 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 seq=$(basename "$0")
  23 echo "QA output created by $seq"
  24
  25 status=1        # failure is the default!
  26
  27 _cleanup()
  28 {
  29     _cleanup_test_img
  30 }
  31 trap "_cleanup; exit \$status" 0 1 2 3 15
  32
  33 # get standard environment, filters and checks
  34 . ./common.rc
  35 . ./common.filter
  36
  37 # This is a qcow2 regression test
  38 _supported_fmt qcow2
  39 _supported_proto file
  40 _supported_os Linux
  41
  42 # We use our own external data file and our own cluster size, and we
  43 # require v3 images
  44 _unsupported_imgopts data_file cluster_size 'compat=0.10'
  45
  46
  47 # We need a backing file so that handle_alloc_space() will not do
  48 # anything.  (If it were to do anything, it would simply fail its
  49 # write-zeroes request because the request range is too large.)
  50 TEST_IMG="$TEST_IMG.base" _make_test_img 4G
  51 $QEMU_IO -c 'write 0 512' "$TEST_IMG.base" | _filter_qemu_io
  52
  53 # (Use .orig because _cleanup_test_img will remove that file)
  54 # We need a large cluster size, see below for why (above the $QEMU_IO
  55 # invocation)
  56 _make_test_img -o cluster_size=2M,data_file="$TEST_IMG.orig" \
  57     -b "$TEST_IMG.base" -F $IMGFMT 4G
  58
  59 # We want a null-co as the data file, because it allows us to quickly
  60 # "write" 2G of data without using any space.
  61 # (qemu-img create does not like it, though, because null-co does not
  62 # support image creation.)
  63 test_img_with_null_data="json:{
  64     'driver': '$IMGFMT',
  65     'file': {
  66         'filename': '$TEST_IMG'
  67     },
  68     'data-file': {
  69         'driver': 'null-co',
  70         'size':'4294967296'
  71     }
  72 }"
  73
  74 # This gives us a range of:
  75 #   2^31 - 512 + 768 - 1 = 2^31 + 255 > 2^31
  76 # until the beginning of the end COW block.  (The total allocation
  77 # size depends on the cluster size, but all that is important is that
  78 # it exceeds INT_MAX.)
  79 #
  80 # 2^31 - 512 is the maximum request size.  We want this to result in a
  81 # single allocation, and because the qcow2 driver splits allocations
  82 # on L2 boundaries, we need large L2 tables; hence the cluster size of
  83 # 2 MB.  (Anything from 256 kB should work, though, because then one L2
  84 # table covers 8 GB.)
  85 $QEMU_IO -c "write 768 $((2 ** 31 - 512))" "$test_img_with_null_data" | _filter_qemu_io
  86
  87 _check_test_img
  88
  89 # success, all done
  90 echo "*** done"
  91 rm -f $seq.full
  92 status=0