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