tests/qemu-iotests/270

   1 #!/usr/bin/env bash
   2 #
   3 # Test large write to a qcow2 image
   4 #
   5 # Copyright (C) 2019 Red Hat, Inc.
   6 #
   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.
  11 #
  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.
  16 #
  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/>.
  19 #
  20
  21 seq=$(basename "$0")
  22 echo "QA output created by $seq"
  23
  24 status=1        # failure is the default!
  25
  26 _cleanup()
  27 {
  28     _cleanup_test_img
  29 }
  30 trap "_cleanup; exit \$status" 0 1 2 3 15
  31
  32 # get standard environment, filters and checks
  33 . ./common.rc
  34 . ./common.filter
  35
  36 # This is a qcow2 regression test
  37 _supported_fmt qcow2
  38 _supported_proto file
  39 _supported_os Linux
  40
  41 # We use our own external data file and our own cluster size, and we
  42 # require v3 images
  43 _unsupported_imgopts data_file cluster_size 'compat=0.10'
  44
  45
  46 # We need a backing file so that handle_alloc_space() will not do
  47 # anything.  (If it were to do anything, it would simply fail its
  48 # write-zeroes request because the request range is too large.)
  49 TEST_IMG="$TEST_IMG.base" _make_test_img 4G
  50 $QEMU_IO -c 'write 0 512' "$TEST_IMG.base" | _filter_qemu_io
  51
  52 # (Use .orig because _cleanup_test_img will remove that file)
  53 # We need a large cluster size, see below for why (above the $QEMU_IO
  54 # invocation)
  55 _make_test_img -o cluster_size=2M,data_file="$TEST_IMG.orig" \
  56     -b "$TEST_IMG.base" 4G
  57
  58 # We want a null-co as the data file, because it allows us to quickly
  59 # "write" 2G of data without using any space.
  60 # (qemu-img create does not like it, though, because null-co does not
  61 # support image creation.)
  62 $QEMU_IMG amend -o data_file="json:{'driver':'null-co',,'size':'4294967296'}" \
  63     "$TEST_IMG"
  64
  65 # This gives us a range of:
  66 #   2^31 - 512 + 768 - 1 = 2^31 + 255 > 2^31
  67 # until the beginning of the end COW block.  (The total allocation
  68 # size depends on the cluster size, but all that is important is that
  69 # it exceeds INT_MAX.)
  70 #
  71 # 2^31 - 512 is the maximum request size.  We want this to result in a
  72 # single allocation, and because the qcow2 driver splits allocations
  73 # on L2 boundaries, we need large L2 tables; hence the cluster size of
  74 # 2 MB.  (Anything from 256 kB should work, though, because then one L2
  75 # table covers 8 GB.)
  76 $QEMU_IO -c "write 768 $((2 ** 31 - 512))" "$TEST_IMG" | _filter_qemu_io
  77
  78 _check_test_img
  79
  80 # success, all done
  81 echo "*** done"
  82 rm -f $seq.full
  83 status=0