tests/qemu-iotests/060

   1 #!/bin/bash
   2 #
   3 # Test case for image corruption (overlapping data structures) in qcow2
   4 #
   5 # Copyright (C) 2013 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 # creator
  22 owner=mreitz@redhat.com
  23
  24 seq="$(basename $0)"
  25 echo "QA output created by $seq"
  26
  27 here="$PWD"
  28 tmp=/tmp/$$
  29 status=1        # failure is the default!
  30
  31 _cleanup()
  32 {
  33         _cleanup_test_img
  34 }
  35 trap "_cleanup; exit \$status" 0 1 2 3 15
  36
  37 # get standard environment, filters and checks
  38 . ./common.env
  39 . ./common.rc
  40 . ./common.filter
  41
  42 # This tests qocw2-specific low-level functionality
  43 _supported_fmt qcow2
  44 _supported_proto file
  45 _supported_os Linux
  46
  47 rt_offset=65536  # 0x10000 (XXX: just an assumption)
  48 rb_offset=131072 # 0x20000 (XXX: just an assumption)
  49 l1_offset=196608 # 0x30000 (XXX: just an assumption)
  50 l2_offset=262144 # 0x40000 (XXX: just an assumption)
  51 l2_offset_after_snapshot=524288 # 0x80000 (XXX: just an assumption)
  52
  53 IMGOPTS="compat=1.1"
  54
  55 OPEN_RW="open -o overlap-check=all $TEST_IMG"
  56 # Overlap checks are done before write operations only, therefore opening an
  57 # image read-only makes the overlap-check option irrelevant
  58 OPEN_RO="open -r $TEST_IMG"
  59
  60 echo
  61 echo "=== Testing L2 reference into L1 ==="
  62 echo
  63 _make_test_img 64M
  64 # Link first L1 entry (first L2 table) onto itself
  65 # (Note the MSb in the L1 entry is set, ensuring the refcount is one - else any
  66 # later write will result in a COW operation, effectively ruining this attempt
  67 # on image corruption)
  68 poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x03\x00\x00"
  69 _check_test_img
  70
  71 # The corrupt bit should not be set anyway
  72 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
  73
  74 # Try to write something, thereby forcing the corrupt bit to be set
  75 $QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io
  76
  77 # The corrupt bit must now be set
  78 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
  79
  80 # Try to open the image R/W (which should fail)
  81 $QEMU_IO -c "$OPEN_RW" -c "read 0 512" 2>&1 | _filter_qemu_io \
  82                                             | _filter_testdir \
  83                                             | _filter_imgfmt
  84
  85 # Try to open it RO (which should succeed)
  86 $QEMU_IO -c "$OPEN_RO" -c "read 0 512" | _filter_qemu_io
  87
  88 # We could now try to fix the image, but this would probably fail (how should an
  89 # L2 table linked onto the L1 table be fixed?)
  90
  91 echo
  92 echo "=== Testing cluster data reference into refcount block ==="
  93 echo
  94 _make_test_img 64M
  95 # Allocate L2 table
  96 truncate -s "$(($l2_offset+65536))" "$TEST_IMG"
  97 poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x04\x00\x00"
  98 # Mark cluster as used
  99 poke_file "$TEST_IMG" "$(($rb_offset+8))" "\x00\x01"
 100 # Redirect new data cluster onto refcount block
 101 poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x02\x00\x00"
 102 _check_test_img
 103 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 104 $QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io
 105 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 106
 107 # Try to fix it
 108 _check_test_img -r all
 109
 110 # The corrupt bit should be cleared
 111 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 112
 113 # Look if it's really really fixed
 114 $QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io
 115 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 116
 117 echo
 118 echo "=== Testing cluster data reference into inactive L2 table ==="
 119 echo
 120 _make_test_img 64M
 121 $QEMU_IO -c "$OPEN_RW" -c "write -P 1 0 512" | _filter_qemu_io
 122 $QEMU_IMG snapshot -c foo "$TEST_IMG"
 123 $QEMU_IO -c "$OPEN_RW" -c "write -P 2 0 512" | _filter_qemu_io
 124 # The inactive L2 table remains at its old offset
 125 poke_file "$TEST_IMG" "$l2_offset_after_snapshot" \
 126                       "\x80\x00\x00\x00\x00\x04\x00\x00"
 127 _check_test_img
 128 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 129 $QEMU_IO -c "$OPEN_RW" -c "write -P 3 0 512" | _filter_qemu_io
 130 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 131 _check_test_img -r all
 132 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 133 $QEMU_IO -c "$OPEN_RW" -c "write -P 4 0 512" | _filter_qemu_io
 134 $PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features
 135
 136 # Check data
 137 $QEMU_IO -c "$OPEN_RO" -c "read -P 4 0 512" | _filter_qemu_io
 138 $QEMU_IMG snapshot -a foo "$TEST_IMG"
 139 _check_test_img
 140 $QEMU_IO -c "$OPEN_RO" -c "read -P 1 0 512" | _filter_qemu_io
 141
 142 echo
 143 echo "=== Testing overlap while COW is in flight ==="
 144 echo
 145 # compat=0.10 is required in order to make the following discard actually
 146 # unallocate the sector rather than make it a zero sector - we want COW, after
 147 # all.
 148 IMGOPTS='compat=0.10' _make_test_img 1G
 149 # Write two clusters, the second one enforces creation of an L2 table after
 150 # the first data cluster.
 151 $QEMU_IO -c 'write 0k 64k' -c 'write 512M 64k' "$TEST_IMG" | _filter_qemu_io
 152 # Discard the first cluster. This cluster will soon enough be reallocated and
 153 # used for COW.
 154 $QEMU_IO -c 'discard 0k 64k' "$TEST_IMG" | _filter_qemu_io
 155 # Now, corrupt the image by marking the second L2 table cluster as free.
 156 poke_file "$TEST_IMG" '131084' "\x00\x00" # 0x2000c
 157 # Start a write operation requiring COW on the image stopping it right before
 158 # doing the read; then, trigger the corruption prevention by writing anything to
 159 # any unallocated cluster, leading to an attempt to overwrite the second L2
 160 # table. Finally, resume the COW write and see it fail (but not crash).
 161 echo "open -o file.driver=blkdebug $TEST_IMG
 162 break cow_read 0
 163 aio_write 0k 1k
 164 wait_break 0
 165 write 64k 64k
 166 resume 0" | $QEMU_IO | _filter_qemu_io
 167
 168 # success, all done
 169 echo "*** done"
 170 rm -f $seq.full
 171 status=0