tests/qemu-iotests/220

   1 #!/usr/bin/env bash
   2 #
   3 # max limits on compression in huge qcow2 files
   4 #
   5 # Copyright (C) 2018 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 $seq"
  23
  24 status=1    # failure is the default!
  25
  26 _cleanup()
  27 {
  28     _cleanup_test_img
  29 }
  30 trap "_cleanup; exit \$status" 0 1 2 3 15
  31
  32 # get standard environment, filters and checks
  33 . ./common.rc
  34 . ./common.filter
  35 . ./common.pattern
  36
  37 _supported_fmt qcow2
  38 _supported_proto file
  39 _supported_os Linux
  40
  41 echo "== Creating huge file =="
  42
  43 # Sanity check: We require a file system that permits the creation
  44 # of a HUGE (but very sparse) file.  tmpfs works, ext4 does not.
  45 if ! truncate --size=513T "$TEST_IMG"; then
  46     _notrun "file system on $TEST_DIR does not support large enough files"
  47 fi
  48 rm "$TEST_IMG"
  49 IMGOPTS='cluster_size=2M,refcount_bits=1' _make_test_img 513T
  50
  51 echo "== Populating refcounts =="
  52 # We want an image with 256M refcounts * 2M clusters = 512T referenced.
  53 # Each 2M cluster holds 16M refcounts; the refcount table initially uses
  54 # 1 refblock, so we need to add 15 more.  The refcount table lives at 2M,
  55 # first refblock at 4M, L2 at 6M, so our remaining additions start at 8M.
  56 # Then, for each refblock, mark it as fully populated.
  57 to_hex() {
  58     printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g'
  59 }
  60 truncate --size=38m "$TEST_IMG"
  61 entry=$((0x200000))
  62 $QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io
  63 for i in {1..15}; do
  64     offs=$((0x600000 + i*0x200000))
  65     poke_file "$TEST_IMG" $((i*8 + entry)) $(to_hex $offs)
  66     $QEMU_IO_PROG -f raw -c "w -P 0xff $offs 2m" "$TEST_IMG" | _filter_qemu_io
  67 done
  68
  69 echo "== Checking file before =="
  70 # FIXME: 'qemu-img check' doesn't diagnose refcounts beyond the end of
  71 # the file as leaked clusters
  72 _check_test_img 2>&1 | sed '/^Leaked cluster/d'
  73 stat -c 'image size %s' "$TEST_IMG"
  74
  75 echo "== Trying to write compressed cluster =="
  76 # Given our file size, the next available cluster at 512T lies beyond the
  77 # maximum offset that a compressed 2M cluster can reside in
  78 $QEMU_IO_PROG -c 'w -c 0 2m' "$TEST_IMG" | _filter_qemu_io
  79 # The attempt failed, but ended up allocating a new refblock
  80 stat -c 'image size %s' "$TEST_IMG"
  81
  82 echo "== Writing normal cluster =="
  83 # The failed write should not corrupt the image, so a normal write succeeds
  84 $QEMU_IO_PROG -c 'w 0 2m' "$TEST_IMG" | _filter_qemu_io
  85
  86 echo "== Checking file after =="
  87 # qemu-img now sees the millions of leaked clusters, thanks to the allocations
  88 # at 512T.  Undo many of our faked references to speed up the check.
  89 $QEMU_IO_PROG -f raw -c "w -z 5m 1m" -c "w -z 8m 30m" "$TEST_IMG" |
  90     _filter_qemu_io
  91 _check_test_img 2>&1 | sed '/^Leaked cluster/d'
  92
  93 # success, all done
  94 echo "*** done"
  95 rm -f $seq.full
  96 status=0