| 1 | #!/usr/bin/env bash |
| 2 | # group: rw auto |
| 3 | # |
| 4 | # max limits on compression in huge qcow2 files |
| 5 | # |
| 6 | # Copyright (C) 2018 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 | . ./common.pattern |
| 37 | |
| 38 | _supported_fmt qcow2 |
| 39 | _supported_proto file fuse |
| 40 | _supported_os Linux |
| 41 | # To use a different refcount width but 16 bits we need compat=1.1, |
| 42 | # and external data files do not support compressed clusters. |
| 43 | _unsupported_imgopts 'compat=0.10' data_file |
| 44 | |
| 45 | echo "== Creating huge file ==" |
| 46 | |
| 47 | # Sanity check: We require a file system that permits the creation |
| 48 | # of a HUGE (but very sparse) file. tmpfs works, ext4 does not. |
| 49 | _require_large_file 513T |
| 50 | |
| 51 | _make_test_img -o 'cluster_size=2M,refcount_bits=1' 513T |
| 52 | |
| 53 | echo "== Populating refcounts ==" |
| 54 | # We want an image with 256M refcounts * 2M clusters = 512T referenced. |
| 55 | # Each 2M cluster holds 16M refcounts; the refcount table initially uses |
| 56 | # 1 refblock, so we need to add 15 more. The refcount table lives at 2M, |
| 57 | # first refblock at 4M, L2 at 6M, so our remaining additions start at 8M. |
| 58 | # Then, for each refblock, mark it as fully populated. |
| 59 | to_hex() { |
| 60 | printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g' |
| 61 | } |
| 62 | truncate --size=38m "$TEST_IMG" |
| 63 | entry=$((0x200000)) |
| 64 | $QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io |
| 65 | for i in {1..15}; do |
| 66 | offs=$((0x600000 + i*0x200000)) |
| 67 | poke_file "$TEST_IMG" $((i*8 + entry)) $(to_hex $offs) |
| 68 | $QEMU_IO_PROG -f raw -c "w -P 0xff $offs 2m" "$TEST_IMG" | _filter_qemu_io |
| 69 | done |
| 70 | |
| 71 | echo "== Checking file before ==" |
| 72 | # FIXME: 'qemu-img check' doesn't diagnose refcounts beyond the end of |
| 73 | # the file as leaked clusters |
| 74 | _check_test_img 2>&1 | sed '/^Leaked cluster/d' |
| 75 | stat -c 'image size %s' "$TEST_IMG" |
| 76 | |
| 77 | echo "== Trying to write compressed cluster ==" |
| 78 | # Given our file size, the next available cluster at 512T lies beyond the |
| 79 | # maximum offset that a compressed 2M cluster can reside in |
| 80 | $QEMU_IO_PROG -c 'w -c 0 2m' "$TEST_IMG" | _filter_qemu_io |
| 81 | # The attempt failed, but ended up allocating a new refblock |
| 82 | stat -c 'image size %s' "$TEST_IMG" |
| 83 | |
| 84 | echo "== Writing normal cluster ==" |
| 85 | # The failed write should not corrupt the image, so a normal write succeeds |
| 86 | $QEMU_IO_PROG -c 'w 0 2m' "$TEST_IMG" | _filter_qemu_io |
| 87 | |
| 88 | echo "== Checking file after ==" |
| 89 | # qemu-img now sees the millions of leaked clusters, thanks to the allocations |
| 90 | # at 512T. Undo many of our faked references to speed up the check. |
| 91 | $QEMU_IO_PROG -f raw -c "w -z 5m 1m" -c "w -z 8m 30m" "$TEST_IMG" | |
| 92 | _filter_qemu_io |
| 93 | _check_test_img 2>&1 | sed '/^Leaked cluster/d' |
| 94 | |
| 95 | # success, all done |
| 96 | echo "*** done" |
| 97 | rm -f $seq.full |
| 98 | status=0 |