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11a82d14 | 1 | #!/usr/bin/env bash |
9dd003a9 | 2 | # group: rw |
0e8a3714 HR |
3 | # |
4 | # Test cases for qcow2 refcount table growth | |
5 | # | |
6 | # Copyright (C) 2015 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 | # creator | |
42a5009d | 23 | owner=hreitz@redhat.com |
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24 | |
25 | seq="$(basename $0)" | |
26 | echo "QA output created by $seq" | |
27 | ||
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28 | status=1 # failure is the default! |
29 | ||
30 | _cleanup() | |
31 | { | |
32 | _cleanup_test_img | |
33 | } | |
34 | trap "_cleanup; exit \$status" 0 1 2 3 15 | |
35 | ||
36 | # get standard environment, filters and checks | |
37 | . ./common.rc | |
38 | . ./common.filter | |
39 | ||
40 | _supported_fmt qcow2 | |
57284d2a | 41 | _supported_proto file fuse |
0e8a3714 | 42 | _supported_os Linux |
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43 | # Refcount structures are used much differently with external data |
44 | # files | |
45 | _unsupported_imgopts data_file | |
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46 | |
47 | echo | |
48 | echo '=== New refcount structures may not conflict with existing structures ===' | |
49 | ||
50 | echo | |
51 | echo '--- Test 1 ---' | |
52 | echo | |
53 | ||
54 | # Preallocation speeds up the write operation, but preallocating everything will | |
55 | # destroy the purpose of the write; so preallocate one KB less than what would | |
56 | # cause a reftable growth... | |
407fb56a | 57 | _make_test_img -o 'preallocation=metadata,cluster_size=1k' 64512K |
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58 | # ...and make the image the desired size afterwards. |
59 | $QEMU_IMG resize "$TEST_IMG" 65M | |
60 | ||
61 | # The first write results in a growth of the refcount table during an allocation | |
62 | # which has precisely the required size so that the new refcount block allocated | |
63 | # in alloc_refcount_block() is right after cluster_index; this did lead to a | |
64 | # different refcount block being written to disk (a zeroed cluster) than what is | |
65 | # cached (a refblock with one entry having a refcount of 1), and the second | |
66 | # write would then result in that cached cluster being marked dirty and then | |
67 | # in it being written to disk. | |
68 | # This should not happen, the new refcount structures may not conflict with | |
69 | # new_block. | |
70 | # (Note that for some reason, 'write 63M 1K' does not trigger the problem) | |
71 | $QEMU_IO -c 'write 62M 1025K' -c 'write 64M 1M' "$TEST_IMG" | _filter_qemu_io | |
72 | ||
73 | _check_test_img | |
74 | ||
75 | ||
76 | echo | |
77 | echo '--- Test 2 ---' | |
78 | echo | |
79 | ||
407fb56a | 80 | _make_test_img -o 'preallocation=metadata,cluster_size=1k' 64513K |
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81 | # This results in an L1 table growth which in turn results in some clusters at |
82 | # the start of the image becoming free | |
83 | $QEMU_IMG resize "$TEST_IMG" 65M | |
84 | ||
85 | # This write results in a refcount table growth; but the refblock allocated | |
86 | # immediately before that (new_block) takes cluster index 4 (which is now free) | |
87 | # and is thus not self-describing (in contrast to test 1, where new_block was | |
88 | # self-describing). The refcount table growth algorithm then used to place the | |
89 | # new refcount structures at cluster index 65536 (which is the same as the | |
90 | # cluster_index parameter in this case), allocating a new refcount block for | |
91 | # that cluster while new_block already existed, leaking new_block. | |
92 | # Therefore, the new refcount structures may not be put at cluster_index | |
93 | # (because new_block already describes that cluster, and the new structures try | |
94 | # to be self-describing). | |
95 | $QEMU_IO -c 'write 63M 130K' "$TEST_IMG" | _filter_qemu_io | |
96 | ||
97 | _check_test_img | |
98 | ||
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99 | echo |
100 | echo '=== Allocating a new refcount block must not leave holes in the image ===' | |
101 | echo | |
102 | ||
407fb56a | 103 | _make_test_img -o 'cluster_size=512,refcount_bits=16' 1M |
abf754fe AG |
104 | |
105 | # This results in an image with 256 used clusters: the qcow2 header, | |
106 | # the refcount table, one refcount block, the L1 table, four L2 tables | |
107 | # and 248 data clusters | |
108 | $QEMU_IO -c 'write 0 124k' "$TEST_IMG" | _filter_qemu_io | |
109 | ||
110 | # 256 clusters of 512 bytes each give us a 128K image | |
111 | stat -c "size=%s (expected 131072)" $TEST_IMG | |
112 | ||
113 | # All 256 entries of the refcount block are used, so writing a new | |
114 | # data cluster also allocates a new refcount block | |
115 | $QEMU_IO -c 'write 124k 512' "$TEST_IMG" | _filter_qemu_io | |
116 | ||
117 | # Two more clusters, the image size should be 129K now | |
118 | stat -c "size=%s (expected 132096)" $TEST_IMG | |
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119 | |
120 | # success, all done | |
121 | echo | |
122 | echo '*** done' | |
123 | rm -f $seq.full | |
124 | status=0 |