4 # max limits on compression in huge qcow2 files
6 # Copyright (C) 2018 Red Hat, Inc.
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.
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.
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/>.
23 echo "QA output created by $seq"
25 status=1 # failure is the default!
31 trap "_cleanup; exit \$status" 0 1 2 3 15
33 # get standard environment, filters and checks
39 _supported_proto file fuse
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
45 echo "== Creating huge file =="
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
51 _make_test_img -o 'cluster_size=2M,refcount_bits=1' 513T
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.
60 printf %016x\\n $1 | sed 's/\(..\)/\\x\1/g'
62 truncate --size=38m "$TEST_IMG"
64 $QEMU_IO_PROG -f raw -c "w -P 0xff 4m 2m" "$TEST_IMG" | _filter_qemu_io
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
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"
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"
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
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" |
93 _check_test_img 2>&1 | sed '/^Leaked cluster/d'