root / block / qcow2-cluster.c @ 80fa3341
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1 | 45aba42f | Kevin Wolf | /*
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2 | 45aba42f | Kevin Wolf | * Block driver for the QCOW version 2 format
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3 | 45aba42f | Kevin Wolf | *
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4 | 45aba42f | Kevin Wolf | * Copyright (c) 2004-2006 Fabrice Bellard
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5 | 45aba42f | Kevin Wolf | *
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6 | 45aba42f | Kevin Wolf | * Permission is hereby granted, free of charge, to any person obtaining a copy
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7 | 45aba42f | Kevin Wolf | * of this software and associated documentation files (the "Software"), to deal
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8 | 45aba42f | Kevin Wolf | * in the Software without restriction, including without limitation the rights
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9 | 45aba42f | Kevin Wolf | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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10 | 45aba42f | Kevin Wolf | * copies of the Software, and to permit persons to whom the Software is
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11 | 45aba42f | Kevin Wolf | * furnished to do so, subject to the following conditions:
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12 | 45aba42f | Kevin Wolf | *
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13 | 45aba42f | Kevin Wolf | * The above copyright notice and this permission notice shall be included in
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14 | 45aba42f | Kevin Wolf | * all copies or substantial portions of the Software.
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15 | 45aba42f | Kevin Wolf | *
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16 | 45aba42f | Kevin Wolf | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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17 | 45aba42f | Kevin Wolf | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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18 | 45aba42f | Kevin Wolf | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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19 | 45aba42f | Kevin Wolf | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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20 | 45aba42f | Kevin Wolf | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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21 | 45aba42f | Kevin Wolf | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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22 | 45aba42f | Kevin Wolf | * THE SOFTWARE.
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23 | 45aba42f | Kevin Wolf | */
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24 | 45aba42f | Kevin Wolf | |
25 | 45aba42f | Kevin Wolf | #include <zlib.h> |
26 | 45aba42f | Kevin Wolf | |
27 | 45aba42f | Kevin Wolf | #include "qemu-common.h" |
28 | 45aba42f | Kevin Wolf | #include "block_int.h" |
29 | 45aba42f | Kevin Wolf | #include "block/qcow2.h" |
30 | 45aba42f | Kevin Wolf | |
31 | 72893756 | Stefan Hajnoczi | int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size) |
32 | 45aba42f | Kevin Wolf | { |
33 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
34 | 45aba42f | Kevin Wolf | int new_l1_size, new_l1_size2, ret, i;
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35 | 45aba42f | Kevin Wolf | uint64_t *new_l1_table; |
36 | 5d757b56 | Kevin Wolf | int64_t new_l1_table_offset; |
37 | 45aba42f | Kevin Wolf | uint8_t data[12];
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38 | 45aba42f | Kevin Wolf | |
39 | 72893756 | Stefan Hajnoczi | if (min_size <= s->l1_size)
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40 | 45aba42f | Kevin Wolf | return 0; |
41 | 72893756 | Stefan Hajnoczi | |
42 | 72893756 | Stefan Hajnoczi | if (exact_size) {
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43 | 72893756 | Stefan Hajnoczi | new_l1_size = min_size; |
44 | 72893756 | Stefan Hajnoczi | } else {
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45 | 72893756 | Stefan Hajnoczi | /* Bump size up to reduce the number of times we have to grow */
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46 | 72893756 | Stefan Hajnoczi | new_l1_size = s->l1_size; |
47 | 72893756 | Stefan Hajnoczi | if (new_l1_size == 0) { |
48 | 72893756 | Stefan Hajnoczi | new_l1_size = 1;
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49 | 72893756 | Stefan Hajnoczi | } |
50 | 72893756 | Stefan Hajnoczi | while (min_size > new_l1_size) {
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51 | 72893756 | Stefan Hajnoczi | new_l1_size = (new_l1_size * 3 + 1) / 2; |
52 | 72893756 | Stefan Hajnoczi | } |
53 | 45aba42f | Kevin Wolf | } |
54 | 72893756 | Stefan Hajnoczi | |
55 | 45aba42f | Kevin Wolf | #ifdef DEBUG_ALLOC2
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56 | 45aba42f | Kevin Wolf | printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
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57 | 45aba42f | Kevin Wolf | #endif
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58 | 45aba42f | Kevin Wolf | |
59 | 45aba42f | Kevin Wolf | new_l1_size2 = sizeof(uint64_t) * new_l1_size;
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60 | 3f6a3ee5 | Kevin Wolf | new_l1_table = qemu_mallocz(align_offset(new_l1_size2, 512));
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61 | 45aba42f | Kevin Wolf | memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
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62 | 45aba42f | Kevin Wolf | |
63 | 45aba42f | Kevin Wolf | /* write new table (align to cluster) */
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64 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE); |
65 | ed6ccf0f | Kevin Wolf | new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2); |
66 | 5d757b56 | Kevin Wolf | if (new_l1_table_offset < 0) { |
67 | 5d757b56 | Kevin Wolf | qemu_free(new_l1_table); |
68 | 5d757b56 | Kevin Wolf | return new_l1_table_offset;
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69 | 5d757b56 | Kevin Wolf | } |
70 | 29c1a730 | Kevin Wolf | |
71 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
72 | 29c1a730 | Kevin Wolf | if (ret < 0) { |
73 | 80fa3341 | Kevin Wolf | goto fail;
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74 | 29c1a730 | Kevin Wolf | } |
75 | 45aba42f | Kevin Wolf | |
76 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE); |
77 | 45aba42f | Kevin Wolf | for(i = 0; i < s->l1_size; i++) |
78 | 45aba42f | Kevin Wolf | new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
79 | 8b3b7206 | Kevin Wolf | ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2); |
80 | 8b3b7206 | Kevin Wolf | if (ret < 0) |
81 | 45aba42f | Kevin Wolf | goto fail;
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82 | 45aba42f | Kevin Wolf | for(i = 0; i < s->l1_size; i++) |
83 | 45aba42f | Kevin Wolf | new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
84 | 45aba42f | Kevin Wolf | |
85 | 45aba42f | Kevin Wolf | /* set new table */
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86 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE); |
87 | 45aba42f | Kevin Wolf | cpu_to_be32w((uint32_t*)data, new_l1_size); |
88 | 653df36b | Aurelien Jarno | cpu_to_be64wu((uint64_t*)(data + 4), new_l1_table_offset);
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89 | 8b3b7206 | Kevin Wolf | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data));
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90 | 8b3b7206 | Kevin Wolf | if (ret < 0) { |
91 | 45aba42f | Kevin Wolf | goto fail;
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92 | fb8fa77c | Kevin Wolf | } |
93 | 45aba42f | Kevin Wolf | qemu_free(s->l1_table); |
94 | ed6ccf0f | Kevin Wolf | qcow2_free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
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95 | 45aba42f | Kevin Wolf | s->l1_table_offset = new_l1_table_offset; |
96 | 45aba42f | Kevin Wolf | s->l1_table = new_l1_table; |
97 | 45aba42f | Kevin Wolf | s->l1_size = new_l1_size; |
98 | 45aba42f | Kevin Wolf | return 0; |
99 | 45aba42f | Kevin Wolf | fail:
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100 | fb8fa77c | Kevin Wolf | qemu_free(new_l1_table); |
101 | fb8fa77c | Kevin Wolf | qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2); |
102 | 8b3b7206 | Kevin Wolf | return ret;
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103 | 45aba42f | Kevin Wolf | } |
104 | 45aba42f | Kevin Wolf | |
105 | 45aba42f | Kevin Wolf | /*
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106 | 45aba42f | Kevin Wolf | * l2_load
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107 | 45aba42f | Kevin Wolf | *
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108 | 45aba42f | Kevin Wolf | * Loads a L2 table into memory. If the table is in the cache, the cache
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109 | 45aba42f | Kevin Wolf | * is used; otherwise the L2 table is loaded from the image file.
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110 | 45aba42f | Kevin Wolf | *
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111 | 45aba42f | Kevin Wolf | * Returns a pointer to the L2 table on success, or NULL if the read from
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112 | 45aba42f | Kevin Wolf | * the image file failed.
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113 | 45aba42f | Kevin Wolf | */
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114 | 45aba42f | Kevin Wolf | |
115 | 55c17e98 | Kevin Wolf | static int l2_load(BlockDriverState *bs, uint64_t l2_offset, |
116 | 55c17e98 | Kevin Wolf | uint64_t **l2_table) |
117 | 45aba42f | Kevin Wolf | { |
118 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
119 | 55c17e98 | Kevin Wolf | int ret;
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120 | 45aba42f | Kevin Wolf | |
121 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, (void**) l2_table);
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122 | 45aba42f | Kevin Wolf | |
123 | 29c1a730 | Kevin Wolf | return ret;
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124 | 45aba42f | Kevin Wolf | } |
125 | 45aba42f | Kevin Wolf | |
126 | 45aba42f | Kevin Wolf | /*
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127 | 6583e3c7 | Kevin Wolf | * Writes one sector of the L1 table to the disk (can't update single entries
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128 | 6583e3c7 | Kevin Wolf | * and we really don't want bdrv_pread to perform a read-modify-write)
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129 | 6583e3c7 | Kevin Wolf | */
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130 | 6583e3c7 | Kevin Wolf | #define L1_ENTRIES_PER_SECTOR (512 / 8) |
131 | 66f82cee | Kevin Wolf | static int write_l1_entry(BlockDriverState *bs, int l1_index) |
132 | 6583e3c7 | Kevin Wolf | { |
133 | 66f82cee | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
134 | 6583e3c7 | Kevin Wolf | uint64_t buf[L1_ENTRIES_PER_SECTOR]; |
135 | 6583e3c7 | Kevin Wolf | int l1_start_index;
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136 | f7defcb6 | Kevin Wolf | int i, ret;
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137 | 6583e3c7 | Kevin Wolf | |
138 | 6583e3c7 | Kevin Wolf | l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1);
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139 | 6583e3c7 | Kevin Wolf | for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { |
140 | 6583e3c7 | Kevin Wolf | buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); |
141 | 6583e3c7 | Kevin Wolf | } |
142 | 6583e3c7 | Kevin Wolf | |
143 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); |
144 | 8b3b7206 | Kevin Wolf | ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index,
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145 | f7defcb6 | Kevin Wolf | buf, sizeof(buf));
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146 | f7defcb6 | Kevin Wolf | if (ret < 0) { |
147 | f7defcb6 | Kevin Wolf | return ret;
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148 | 6583e3c7 | Kevin Wolf | } |
149 | 6583e3c7 | Kevin Wolf | |
150 | 6583e3c7 | Kevin Wolf | return 0; |
151 | 6583e3c7 | Kevin Wolf | } |
152 | 6583e3c7 | Kevin Wolf | |
153 | 6583e3c7 | Kevin Wolf | /*
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154 | 45aba42f | Kevin Wolf | * l2_allocate
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155 | 45aba42f | Kevin Wolf | *
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156 | 45aba42f | Kevin Wolf | * Allocate a new l2 entry in the file. If l1_index points to an already
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157 | 45aba42f | Kevin Wolf | * used entry in the L2 table (i.e. we are doing a copy on write for the L2
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158 | 45aba42f | Kevin Wolf | * table) copy the contents of the old L2 table into the newly allocated one.
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159 | 45aba42f | Kevin Wolf | * Otherwise the new table is initialized with zeros.
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160 | 45aba42f | Kevin Wolf | *
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161 | 45aba42f | Kevin Wolf | */
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162 | 45aba42f | Kevin Wolf | |
163 | c46e1167 | Kevin Wolf | static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) |
164 | 45aba42f | Kevin Wolf | { |
165 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
166 | 6583e3c7 | Kevin Wolf | uint64_t old_l2_offset; |
167 | f4f0d391 | Kevin Wolf | uint64_t *l2_table; |
168 | f4f0d391 | Kevin Wolf | int64_t l2_offset; |
169 | c46e1167 | Kevin Wolf | int ret;
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170 | 45aba42f | Kevin Wolf | |
171 | 45aba42f | Kevin Wolf | old_l2_offset = s->l1_table[l1_index]; |
172 | 45aba42f | Kevin Wolf | |
173 | 45aba42f | Kevin Wolf | /* allocate a new l2 entry */
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174 | 45aba42f | Kevin Wolf | |
175 | ed6ccf0f | Kevin Wolf | l2_offset = qcow2_alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
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176 | 5d757b56 | Kevin Wolf | if (l2_offset < 0) { |
177 | c46e1167 | Kevin Wolf | return l2_offset;
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178 | 5d757b56 | Kevin Wolf | } |
179 | 29c1a730 | Kevin Wolf | |
180 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
181 | 29c1a730 | Kevin Wolf | if (ret < 0) { |
182 | 29c1a730 | Kevin Wolf | goto fail;
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183 | 29c1a730 | Kevin Wolf | } |
184 | 45aba42f | Kevin Wolf | |
185 | 45aba42f | Kevin Wolf | /* allocate a new entry in the l2 cache */
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186 | 45aba42f | Kevin Wolf | |
187 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_get_empty(bs, s->l2_table_cache, l2_offset, (void**) table);
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188 | 29c1a730 | Kevin Wolf | if (ret < 0) { |
189 | 29c1a730 | Kevin Wolf | return ret;
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190 | 29c1a730 | Kevin Wolf | } |
191 | 29c1a730 | Kevin Wolf | |
192 | 29c1a730 | Kevin Wolf | l2_table = *table; |
193 | 45aba42f | Kevin Wolf | |
194 | 45aba42f | Kevin Wolf | if (old_l2_offset == 0) { |
195 | 45aba42f | Kevin Wolf | /* if there was no old l2 table, clear the new table */
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196 | 45aba42f | Kevin Wolf | memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
197 | 45aba42f | Kevin Wolf | } else {
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198 | 29c1a730 | Kevin Wolf | uint64_t* old_table; |
199 | 29c1a730 | Kevin Wolf | |
200 | 45aba42f | Kevin Wolf | /* if there was an old l2 table, read it from the disk */
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201 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ); |
202 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_get(bs, s->l2_table_cache, old_l2_offset, |
203 | 29c1a730 | Kevin Wolf | (void**) &old_table);
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204 | 29c1a730 | Kevin Wolf | if (ret < 0) { |
205 | 29c1a730 | Kevin Wolf | goto fail;
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206 | 29c1a730 | Kevin Wolf | } |
207 | 29c1a730 | Kevin Wolf | |
208 | 29c1a730 | Kevin Wolf | memcpy(l2_table, old_table, s->cluster_size); |
209 | 29c1a730 | Kevin Wolf | |
210 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &old_table);
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211 | c46e1167 | Kevin Wolf | if (ret < 0) { |
212 | 175e1152 | Kevin Wolf | goto fail;
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213 | c46e1167 | Kevin Wolf | } |
214 | 45aba42f | Kevin Wolf | } |
215 | 29c1a730 | Kevin Wolf | |
216 | 45aba42f | Kevin Wolf | /* write the l2 table to the file */
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217 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE); |
218 | 29c1a730 | Kevin Wolf | |
219 | 29c1a730 | Kevin Wolf | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
220 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
221 | c46e1167 | Kevin Wolf | if (ret < 0) { |
222 | 175e1152 | Kevin Wolf | goto fail;
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223 | 175e1152 | Kevin Wolf | } |
224 | 175e1152 | Kevin Wolf | |
225 | 175e1152 | Kevin Wolf | /* update the L1 entry */
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226 | 175e1152 | Kevin Wolf | s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
227 | 175e1152 | Kevin Wolf | ret = write_l1_entry(bs, l1_index); |
228 | 175e1152 | Kevin Wolf | if (ret < 0) { |
229 | 175e1152 | Kevin Wolf | goto fail;
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230 | c46e1167 | Kevin Wolf | } |
231 | 45aba42f | Kevin Wolf | |
232 | c46e1167 | Kevin Wolf | *table = l2_table; |
233 | c46e1167 | Kevin Wolf | return 0; |
234 | 175e1152 | Kevin Wolf | |
235 | 175e1152 | Kevin Wolf | fail:
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236 | 29c1a730 | Kevin Wolf | qcow2_cache_put(bs, s->l2_table_cache, (void**) table);
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237 | 68dba0bf | Kevin Wolf | s->l1_table[l1_index] = old_l2_offset; |
238 | 175e1152 | Kevin Wolf | return ret;
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239 | 45aba42f | Kevin Wolf | } |
240 | 45aba42f | Kevin Wolf | |
241 | 45aba42f | Kevin Wolf | static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
242 | 45aba42f | Kevin Wolf | uint64_t *l2_table, uint64_t start, uint64_t mask) |
243 | 45aba42f | Kevin Wolf | { |
244 | 45aba42f | Kevin Wolf | int i;
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245 | 45aba42f | Kevin Wolf | uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
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246 | 45aba42f | Kevin Wolf | |
247 | 45aba42f | Kevin Wolf | if (!offset)
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248 | 45aba42f | Kevin Wolf | return 0; |
249 | 45aba42f | Kevin Wolf | |
250 | 45aba42f | Kevin Wolf | for (i = start; i < start + nb_clusters; i++)
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251 | 80ee15a6 | Kevin Wolf | if (offset + (uint64_t) i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
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252 | 45aba42f | Kevin Wolf | break;
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253 | 45aba42f | Kevin Wolf | |
254 | 45aba42f | Kevin Wolf | return (i - start);
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255 | 45aba42f | Kevin Wolf | } |
256 | 45aba42f | Kevin Wolf | |
257 | 45aba42f | Kevin Wolf | static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
258 | 45aba42f | Kevin Wolf | { |
259 | 45aba42f | Kevin Wolf | int i = 0; |
260 | 45aba42f | Kevin Wolf | |
261 | 45aba42f | Kevin Wolf | while(nb_clusters-- && l2_table[i] == 0) |
262 | 45aba42f | Kevin Wolf | i++; |
263 | 45aba42f | Kevin Wolf | |
264 | 45aba42f | Kevin Wolf | return i;
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265 | 45aba42f | Kevin Wolf | } |
266 | 45aba42f | Kevin Wolf | |
267 | 45aba42f | Kevin Wolf | /* The crypt function is compatible with the linux cryptoloop
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268 | 45aba42f | Kevin Wolf | algorithm for < 4 GB images. NOTE: out_buf == in_buf is
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269 | 45aba42f | Kevin Wolf | supported */
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270 | ed6ccf0f | Kevin Wolf | void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
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271 | ed6ccf0f | Kevin Wolf | uint8_t *out_buf, const uint8_t *in_buf,
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272 | ed6ccf0f | Kevin Wolf | int nb_sectors, int enc, |
273 | ed6ccf0f | Kevin Wolf | const AES_KEY *key)
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274 | 45aba42f | Kevin Wolf | { |
275 | 45aba42f | Kevin Wolf | union {
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276 | 45aba42f | Kevin Wolf | uint64_t ll[2];
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277 | 45aba42f | Kevin Wolf | uint8_t b[16];
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278 | 45aba42f | Kevin Wolf | } ivec; |
279 | 45aba42f | Kevin Wolf | int i;
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280 | 45aba42f | Kevin Wolf | |
281 | 45aba42f | Kevin Wolf | for(i = 0; i < nb_sectors; i++) { |
282 | 45aba42f | Kevin Wolf | ivec.ll[0] = cpu_to_le64(sector_num);
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283 | 45aba42f | Kevin Wolf | ivec.ll[1] = 0; |
284 | 45aba42f | Kevin Wolf | AES_cbc_encrypt(in_buf, out_buf, 512, key,
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285 | 45aba42f | Kevin Wolf | ivec.b, enc); |
286 | 45aba42f | Kevin Wolf | sector_num++; |
287 | 45aba42f | Kevin Wolf | in_buf += 512;
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288 | 45aba42f | Kevin Wolf | out_buf += 512;
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289 | 45aba42f | Kevin Wolf | } |
290 | 45aba42f | Kevin Wolf | } |
291 | 45aba42f | Kevin Wolf | |
292 | 45aba42f | Kevin Wolf | |
293 | 7c80ab3f | Jes Sorensen | static int qcow2_read(BlockDriverState *bs, int64_t sector_num, |
294 | 7c80ab3f | Jes Sorensen | uint8_t *buf, int nb_sectors)
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295 | 45aba42f | Kevin Wolf | { |
296 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
297 | 45aba42f | Kevin Wolf | int ret, index_in_cluster, n, n1;
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298 | 45aba42f | Kevin Wolf | uint64_t cluster_offset; |
299 | bd28f835 | Kevin Wolf | struct iovec iov;
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300 | bd28f835 | Kevin Wolf | QEMUIOVector qiov; |
301 | 45aba42f | Kevin Wolf | |
302 | 45aba42f | Kevin Wolf | while (nb_sectors > 0) { |
303 | 45aba42f | Kevin Wolf | n = nb_sectors; |
304 | 1c46efaa | Kevin Wolf | |
305 | 1c46efaa | Kevin Wolf | ret = qcow2_get_cluster_offset(bs, sector_num << 9, &n,
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306 | 1c46efaa | Kevin Wolf | &cluster_offset); |
307 | 1c46efaa | Kevin Wolf | if (ret < 0) { |
308 | 1c46efaa | Kevin Wolf | return ret;
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309 | 1c46efaa | Kevin Wolf | } |
310 | 1c46efaa | Kevin Wolf | |
311 | 45aba42f | Kevin Wolf | index_in_cluster = sector_num & (s->cluster_sectors - 1);
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312 | 45aba42f | Kevin Wolf | if (!cluster_offset) {
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313 | 45aba42f | Kevin Wolf | if (bs->backing_hd) {
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314 | 45aba42f | Kevin Wolf | /* read from the base image */
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315 | bd28f835 | Kevin Wolf | iov.iov_base = buf; |
316 | bd28f835 | Kevin Wolf | iov.iov_len = n * 512;
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317 | bd28f835 | Kevin Wolf | qemu_iovec_init_external(&qiov, &iov, 1);
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318 | bd28f835 | Kevin Wolf | |
319 | bd28f835 | Kevin Wolf | n1 = qcow2_backing_read1(bs->backing_hd, &qiov, sector_num, n); |
320 | 45aba42f | Kevin Wolf | if (n1 > 0) { |
321 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING); |
322 | 45aba42f | Kevin Wolf | ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
323 | 45aba42f | Kevin Wolf | if (ret < 0) |
324 | 45aba42f | Kevin Wolf | return -1; |
325 | 45aba42f | Kevin Wolf | } |
326 | 45aba42f | Kevin Wolf | } else {
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327 | 45aba42f | Kevin Wolf | memset(buf, 0, 512 * n); |
328 | 45aba42f | Kevin Wolf | } |
329 | 45aba42f | Kevin Wolf | } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
330 | 66f82cee | Kevin Wolf | if (qcow2_decompress_cluster(bs, cluster_offset) < 0) |
331 | 45aba42f | Kevin Wolf | return -1; |
332 | 45aba42f | Kevin Wolf | memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
333 | 45aba42f | Kevin Wolf | } else {
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334 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_READ); |
335 | 66f82cee | Kevin Wolf | ret = bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512); |
336 | 45aba42f | Kevin Wolf | if (ret != n * 512) |
337 | 45aba42f | Kevin Wolf | return -1; |
338 | 45aba42f | Kevin Wolf | if (s->crypt_method) {
|
339 | ed6ccf0f | Kevin Wolf | qcow2_encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
340 | 45aba42f | Kevin Wolf | &s->aes_decrypt_key); |
341 | 45aba42f | Kevin Wolf | } |
342 | 45aba42f | Kevin Wolf | } |
343 | 45aba42f | Kevin Wolf | nb_sectors -= n; |
344 | 45aba42f | Kevin Wolf | sector_num += n; |
345 | 45aba42f | Kevin Wolf | buf += n * 512;
|
346 | 45aba42f | Kevin Wolf | } |
347 | 45aba42f | Kevin Wolf | return 0; |
348 | 45aba42f | Kevin Wolf | } |
349 | 45aba42f | Kevin Wolf | |
350 | 45aba42f | Kevin Wolf | static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
351 | 45aba42f | Kevin Wolf | uint64_t cluster_offset, int n_start, int n_end) |
352 | 45aba42f | Kevin Wolf | { |
353 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
354 | 45aba42f | Kevin Wolf | int n, ret;
|
355 | 45aba42f | Kevin Wolf | |
356 | 45aba42f | Kevin Wolf | n = n_end - n_start; |
357 | 45aba42f | Kevin Wolf | if (n <= 0) |
358 | 45aba42f | Kevin Wolf | return 0; |
359 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_COW_READ); |
360 | 7c80ab3f | Jes Sorensen | ret = qcow2_read(bs, start_sect + n_start, s->cluster_data, n); |
361 | 45aba42f | Kevin Wolf | if (ret < 0) |
362 | 45aba42f | Kevin Wolf | return ret;
|
363 | 45aba42f | Kevin Wolf | if (s->crypt_method) {
|
364 | ed6ccf0f | Kevin Wolf | qcow2_encrypt_sectors(s, start_sect + n_start, |
365 | 45aba42f | Kevin Wolf | s->cluster_data, |
366 | 45aba42f | Kevin Wolf | s->cluster_data, n, 1,
|
367 | 45aba42f | Kevin Wolf | &s->aes_encrypt_key); |
368 | 45aba42f | Kevin Wolf | } |
369 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE); |
370 | 9f8e668e | Kevin Wolf | ret = bdrv_write(bs->file, (cluster_offset >> 9) + n_start,
|
371 | 8b3b7206 | Kevin Wolf | s->cluster_data, n); |
372 | 45aba42f | Kevin Wolf | if (ret < 0) |
373 | 45aba42f | Kevin Wolf | return ret;
|
374 | 45aba42f | Kevin Wolf | return 0; |
375 | 45aba42f | Kevin Wolf | } |
376 | 45aba42f | Kevin Wolf | |
377 | 45aba42f | Kevin Wolf | |
378 | 45aba42f | Kevin Wolf | /*
|
379 | 45aba42f | Kevin Wolf | * get_cluster_offset
|
380 | 45aba42f | Kevin Wolf | *
|
381 | 1c46efaa | Kevin Wolf | * For a given offset of the disk image, find the cluster offset in
|
382 | 1c46efaa | Kevin Wolf | * qcow2 file. The offset is stored in *cluster_offset.
|
383 | 45aba42f | Kevin Wolf | *
|
384 | 45aba42f | Kevin Wolf | * on entry, *num is the number of contiguous clusters we'd like to
|
385 | 45aba42f | Kevin Wolf | * access following offset.
|
386 | 45aba42f | Kevin Wolf | *
|
387 | 45aba42f | Kevin Wolf | * on exit, *num is the number of contiguous clusters we can read.
|
388 | 45aba42f | Kevin Wolf | *
|
389 | 1c46efaa | Kevin Wolf | * Return 0, if the offset is found
|
390 | 1c46efaa | Kevin Wolf | * Return -errno, otherwise.
|
391 | 45aba42f | Kevin Wolf | *
|
392 | 45aba42f | Kevin Wolf | */
|
393 | 45aba42f | Kevin Wolf | |
394 | 1c46efaa | Kevin Wolf | int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
|
395 | 1c46efaa | Kevin Wolf | int *num, uint64_t *cluster_offset)
|
396 | 45aba42f | Kevin Wolf | { |
397 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
398 | 80ee15a6 | Kevin Wolf | unsigned int l1_index, l2_index; |
399 | 1c46efaa | Kevin Wolf | uint64_t l2_offset, *l2_table; |
400 | 45aba42f | Kevin Wolf | int l1_bits, c;
|
401 | 80ee15a6 | Kevin Wolf | unsigned int index_in_cluster, nb_clusters; |
402 | 80ee15a6 | Kevin Wolf | uint64_t nb_available, nb_needed; |
403 | 55c17e98 | Kevin Wolf | int ret;
|
404 | 45aba42f | Kevin Wolf | |
405 | 45aba42f | Kevin Wolf | index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
406 | 45aba42f | Kevin Wolf | nb_needed = *num + index_in_cluster; |
407 | 45aba42f | Kevin Wolf | |
408 | 45aba42f | Kevin Wolf | l1_bits = s->l2_bits + s->cluster_bits; |
409 | 45aba42f | Kevin Wolf | |
410 | 45aba42f | Kevin Wolf | /* compute how many bytes there are between the offset and
|
411 | 45aba42f | Kevin Wolf | * the end of the l1 entry
|
412 | 45aba42f | Kevin Wolf | */
|
413 | 45aba42f | Kevin Wolf | |
414 | 80ee15a6 | Kevin Wolf | nb_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1)); |
415 | 45aba42f | Kevin Wolf | |
416 | 45aba42f | Kevin Wolf | /* compute the number of available sectors */
|
417 | 45aba42f | Kevin Wolf | |
418 | 45aba42f | Kevin Wolf | nb_available = (nb_available >> 9) + index_in_cluster;
|
419 | 45aba42f | Kevin Wolf | |
420 | 45aba42f | Kevin Wolf | if (nb_needed > nb_available) {
|
421 | 45aba42f | Kevin Wolf | nb_needed = nb_available; |
422 | 45aba42f | Kevin Wolf | } |
423 | 45aba42f | Kevin Wolf | |
424 | 1c46efaa | Kevin Wolf | *cluster_offset = 0;
|
425 | 45aba42f | Kevin Wolf | |
426 | 45aba42f | Kevin Wolf | /* seek the the l2 offset in the l1 table */
|
427 | 45aba42f | Kevin Wolf | |
428 | 45aba42f | Kevin Wolf | l1_index = offset >> l1_bits; |
429 | 45aba42f | Kevin Wolf | if (l1_index >= s->l1_size)
|
430 | 45aba42f | Kevin Wolf | goto out;
|
431 | 45aba42f | Kevin Wolf | |
432 | 45aba42f | Kevin Wolf | l2_offset = s->l1_table[l1_index]; |
433 | 45aba42f | Kevin Wolf | |
434 | 45aba42f | Kevin Wolf | /* seek the l2 table of the given l2 offset */
|
435 | 45aba42f | Kevin Wolf | |
436 | 45aba42f | Kevin Wolf | if (!l2_offset)
|
437 | 45aba42f | Kevin Wolf | goto out;
|
438 | 45aba42f | Kevin Wolf | |
439 | 45aba42f | Kevin Wolf | /* load the l2 table in memory */
|
440 | 45aba42f | Kevin Wolf | |
441 | 45aba42f | Kevin Wolf | l2_offset &= ~QCOW_OFLAG_COPIED; |
442 | 55c17e98 | Kevin Wolf | ret = l2_load(bs, l2_offset, &l2_table); |
443 | 55c17e98 | Kevin Wolf | if (ret < 0) { |
444 | 55c17e98 | Kevin Wolf | return ret;
|
445 | 1c46efaa | Kevin Wolf | } |
446 | 45aba42f | Kevin Wolf | |
447 | 45aba42f | Kevin Wolf | /* find the cluster offset for the given disk offset */
|
448 | 45aba42f | Kevin Wolf | |
449 | 45aba42f | Kevin Wolf | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
450 | 1c46efaa | Kevin Wolf | *cluster_offset = be64_to_cpu(l2_table[l2_index]); |
451 | 45aba42f | Kevin Wolf | nb_clusters = size_to_clusters(s, nb_needed << 9);
|
452 | 45aba42f | Kevin Wolf | |
453 | 1c46efaa | Kevin Wolf | if (!*cluster_offset) {
|
454 | 45aba42f | Kevin Wolf | /* how many empty clusters ? */
|
455 | 45aba42f | Kevin Wolf | c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
456 | 45aba42f | Kevin Wolf | } else {
|
457 | 45aba42f | Kevin Wolf | /* how many allocated clusters ? */
|
458 | 45aba42f | Kevin Wolf | c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
459 | 45aba42f | Kevin Wolf | &l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
|
460 | 45aba42f | Kevin Wolf | } |
461 | 45aba42f | Kevin Wolf | |
462 | 29c1a730 | Kevin Wolf | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
463 | 29c1a730 | Kevin Wolf | |
464 | 45aba42f | Kevin Wolf | nb_available = (c * s->cluster_sectors); |
465 | 45aba42f | Kevin Wolf | out:
|
466 | 45aba42f | Kevin Wolf | if (nb_available > nb_needed)
|
467 | 45aba42f | Kevin Wolf | nb_available = nb_needed; |
468 | 45aba42f | Kevin Wolf | |
469 | 45aba42f | Kevin Wolf | *num = nb_available - index_in_cluster; |
470 | 45aba42f | Kevin Wolf | |
471 | 1c46efaa | Kevin Wolf | *cluster_offset &=~QCOW_OFLAG_COPIED; |
472 | 1c46efaa | Kevin Wolf | return 0; |
473 | 45aba42f | Kevin Wolf | } |
474 | 45aba42f | Kevin Wolf | |
475 | 45aba42f | Kevin Wolf | /*
|
476 | 45aba42f | Kevin Wolf | * get_cluster_table
|
477 | 45aba42f | Kevin Wolf | *
|
478 | 45aba42f | Kevin Wolf | * for a given disk offset, load (and allocate if needed)
|
479 | 45aba42f | Kevin Wolf | * the l2 table.
|
480 | 45aba42f | Kevin Wolf | *
|
481 | 45aba42f | Kevin Wolf | * the l2 table offset in the qcow2 file and the cluster index
|
482 | 45aba42f | Kevin Wolf | * in the l2 table are given to the caller.
|
483 | 45aba42f | Kevin Wolf | *
|
484 | 1e3e8f1a | Kevin Wolf | * Returns 0 on success, -errno in failure case
|
485 | 45aba42f | Kevin Wolf | */
|
486 | 45aba42f | Kevin Wolf | static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
487 | 45aba42f | Kevin Wolf | uint64_t **new_l2_table, |
488 | 45aba42f | Kevin Wolf | uint64_t *new_l2_offset, |
489 | 45aba42f | Kevin Wolf | int *new_l2_index)
|
490 | 45aba42f | Kevin Wolf | { |
491 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
492 | 80ee15a6 | Kevin Wolf | unsigned int l1_index, l2_index; |
493 | c46e1167 | Kevin Wolf | uint64_t l2_offset; |
494 | c46e1167 | Kevin Wolf | uint64_t *l2_table = NULL;
|
495 | 80ee15a6 | Kevin Wolf | int ret;
|
496 | 45aba42f | Kevin Wolf | |
497 | 45aba42f | Kevin Wolf | /* seek the the l2 offset in the l1 table */
|
498 | 45aba42f | Kevin Wolf | |
499 | 45aba42f | Kevin Wolf | l1_index = offset >> (s->l2_bits + s->cluster_bits); |
500 | 45aba42f | Kevin Wolf | if (l1_index >= s->l1_size) {
|
501 | 72893756 | Stefan Hajnoczi | ret = qcow2_grow_l1_table(bs, l1_index + 1, false); |
502 | 1e3e8f1a | Kevin Wolf | if (ret < 0) { |
503 | 1e3e8f1a | Kevin Wolf | return ret;
|
504 | 1e3e8f1a | Kevin Wolf | } |
505 | 45aba42f | Kevin Wolf | } |
506 | 45aba42f | Kevin Wolf | l2_offset = s->l1_table[l1_index]; |
507 | 45aba42f | Kevin Wolf | |
508 | 45aba42f | Kevin Wolf | /* seek the l2 table of the given l2 offset */
|
509 | 45aba42f | Kevin Wolf | |
510 | 45aba42f | Kevin Wolf | if (l2_offset & QCOW_OFLAG_COPIED) {
|
511 | 45aba42f | Kevin Wolf | /* load the l2 table in memory */
|
512 | 45aba42f | Kevin Wolf | l2_offset &= ~QCOW_OFLAG_COPIED; |
513 | 55c17e98 | Kevin Wolf | ret = l2_load(bs, l2_offset, &l2_table); |
514 | 55c17e98 | Kevin Wolf | if (ret < 0) { |
515 | 55c17e98 | Kevin Wolf | return ret;
|
516 | 1e3e8f1a | Kevin Wolf | } |
517 | 45aba42f | Kevin Wolf | } else {
|
518 | 16fde5f2 | Kevin Wolf | /* First allocate a new L2 table (and do COW if needed) */
|
519 | c46e1167 | Kevin Wolf | ret = l2_allocate(bs, l1_index, &l2_table); |
520 | c46e1167 | Kevin Wolf | if (ret < 0) { |
521 | c46e1167 | Kevin Wolf | return ret;
|
522 | 1e3e8f1a | Kevin Wolf | } |
523 | 16fde5f2 | Kevin Wolf | |
524 | 16fde5f2 | Kevin Wolf | /* Then decrease the refcount of the old table */
|
525 | 16fde5f2 | Kevin Wolf | if (l2_offset) {
|
526 | 16fde5f2 | Kevin Wolf | qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
|
527 | 16fde5f2 | Kevin Wolf | } |
528 | 45aba42f | Kevin Wolf | l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
529 | 45aba42f | Kevin Wolf | } |
530 | 45aba42f | Kevin Wolf | |
531 | 45aba42f | Kevin Wolf | /* find the cluster offset for the given disk offset */
|
532 | 45aba42f | Kevin Wolf | |
533 | 45aba42f | Kevin Wolf | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
534 | 45aba42f | Kevin Wolf | |
535 | 45aba42f | Kevin Wolf | *new_l2_table = l2_table; |
536 | 45aba42f | Kevin Wolf | *new_l2_offset = l2_offset; |
537 | 45aba42f | Kevin Wolf | *new_l2_index = l2_index; |
538 | 45aba42f | Kevin Wolf | |
539 | 1e3e8f1a | Kevin Wolf | return 0; |
540 | 45aba42f | Kevin Wolf | } |
541 | 45aba42f | Kevin Wolf | |
542 | 45aba42f | Kevin Wolf | /*
|
543 | 45aba42f | Kevin Wolf | * alloc_compressed_cluster_offset
|
544 | 45aba42f | Kevin Wolf | *
|
545 | 45aba42f | Kevin Wolf | * For a given offset of the disk image, return cluster offset in
|
546 | 45aba42f | Kevin Wolf | * qcow2 file.
|
547 | 45aba42f | Kevin Wolf | *
|
548 | 45aba42f | Kevin Wolf | * If the offset is not found, allocate a new compressed cluster.
|
549 | 45aba42f | Kevin Wolf | *
|
550 | 45aba42f | Kevin Wolf | * Return the cluster offset if successful,
|
551 | 45aba42f | Kevin Wolf | * Return 0, otherwise.
|
552 | 45aba42f | Kevin Wolf | *
|
553 | 45aba42f | Kevin Wolf | */
|
554 | 45aba42f | Kevin Wolf | |
555 | ed6ccf0f | Kevin Wolf | uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, |
556 | ed6ccf0f | Kevin Wolf | uint64_t offset, |
557 | ed6ccf0f | Kevin Wolf | int compressed_size)
|
558 | 45aba42f | Kevin Wolf | { |
559 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
560 | 45aba42f | Kevin Wolf | int l2_index, ret;
|
561 | f4f0d391 | Kevin Wolf | uint64_t l2_offset, *l2_table; |
562 | f4f0d391 | Kevin Wolf | int64_t cluster_offset; |
563 | 45aba42f | Kevin Wolf | int nb_csectors;
|
564 | 45aba42f | Kevin Wolf | |
565 | 45aba42f | Kevin Wolf | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
566 | 1e3e8f1a | Kevin Wolf | if (ret < 0) { |
567 | 45aba42f | Kevin Wolf | return 0; |
568 | 1e3e8f1a | Kevin Wolf | } |
569 | 45aba42f | Kevin Wolf | |
570 | 45aba42f | Kevin Wolf | cluster_offset = be64_to_cpu(l2_table[l2_index]); |
571 | 45aba42f | Kevin Wolf | if (cluster_offset & QCOW_OFLAG_COPIED)
|
572 | 45aba42f | Kevin Wolf | return cluster_offset & ~QCOW_OFLAG_COPIED;
|
573 | 45aba42f | Kevin Wolf | |
574 | 45aba42f | Kevin Wolf | if (cluster_offset)
|
575 | ed6ccf0f | Kevin Wolf | qcow2_free_any_clusters(bs, cluster_offset, 1);
|
576 | 45aba42f | Kevin Wolf | |
577 | ed6ccf0f | Kevin Wolf | cluster_offset = qcow2_alloc_bytes(bs, compressed_size); |
578 | 5d757b56 | Kevin Wolf | if (cluster_offset < 0) { |
579 | 29c1a730 | Kevin Wolf | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
580 | 5d757b56 | Kevin Wolf | return 0; |
581 | 5d757b56 | Kevin Wolf | } |
582 | 5d757b56 | Kevin Wolf | |
583 | 45aba42f | Kevin Wolf | nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
584 | 45aba42f | Kevin Wolf | (cluster_offset >> 9);
|
585 | 45aba42f | Kevin Wolf | |
586 | 45aba42f | Kevin Wolf | cluster_offset |= QCOW_OFLAG_COMPRESSED | |
587 | 45aba42f | Kevin Wolf | ((uint64_t)nb_csectors << s->csize_shift); |
588 | 45aba42f | Kevin Wolf | |
589 | 45aba42f | Kevin Wolf | /* update L2 table */
|
590 | 45aba42f | Kevin Wolf | |
591 | 45aba42f | Kevin Wolf | /* compressed clusters never have the copied flag */
|
592 | 45aba42f | Kevin Wolf | |
593 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED); |
594 | 29c1a730 | Kevin Wolf | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
595 | 45aba42f | Kevin Wolf | l2_table[l2_index] = cpu_to_be64(cluster_offset); |
596 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
597 | 79a31189 | Kevin Wolf | if (ret < 0) { |
598 | 29c1a730 | Kevin Wolf | return 0; |
599 | 4c1612d9 | Kevin Wolf | } |
600 | 4c1612d9 | Kevin Wolf | |
601 | 29c1a730 | Kevin Wolf | return cluster_offset;
|
602 | 4c1612d9 | Kevin Wolf | } |
603 | 4c1612d9 | Kevin Wolf | |
604 | 148da7ea | Kevin Wolf | int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
|
605 | 45aba42f | Kevin Wolf | { |
606 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
607 | 45aba42f | Kevin Wolf | int i, j = 0, l2_index, ret; |
608 | 45aba42f | Kevin Wolf | uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
609 | 148da7ea | Kevin Wolf | uint64_t cluster_offset = m->cluster_offset; |
610 | 29c1a730 | Kevin Wolf | bool cow = false; |
611 | 45aba42f | Kevin Wolf | |
612 | 45aba42f | Kevin Wolf | if (m->nb_clusters == 0) |
613 | 45aba42f | Kevin Wolf | return 0; |
614 | 45aba42f | Kevin Wolf | |
615 | 45aba42f | Kevin Wolf | old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
|
616 | 45aba42f | Kevin Wolf | |
617 | 45aba42f | Kevin Wolf | /* copy content of unmodified sectors */
|
618 | 45aba42f | Kevin Wolf | start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
619 | 45aba42f | Kevin Wolf | if (m->n_start) {
|
620 | 29c1a730 | Kevin Wolf | cow = true;
|
621 | 45aba42f | Kevin Wolf | ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
|
622 | 45aba42f | Kevin Wolf | if (ret < 0) |
623 | 45aba42f | Kevin Wolf | goto err;
|
624 | 45aba42f | Kevin Wolf | } |
625 | 45aba42f | Kevin Wolf | |
626 | 45aba42f | Kevin Wolf | if (m->nb_available & (s->cluster_sectors - 1)) { |
627 | 45aba42f | Kevin Wolf | uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
|
628 | 29c1a730 | Kevin Wolf | cow = true;
|
629 | 45aba42f | Kevin Wolf | ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
|
630 | 45aba42f | Kevin Wolf | m->nb_available - end, s->cluster_sectors); |
631 | 45aba42f | Kevin Wolf | if (ret < 0) |
632 | 45aba42f | Kevin Wolf | goto err;
|
633 | 45aba42f | Kevin Wolf | } |
634 | 45aba42f | Kevin Wolf | |
635 | 29c1a730 | Kevin Wolf | /*
|
636 | 29c1a730 | Kevin Wolf | * Update L2 table.
|
637 | 29c1a730 | Kevin Wolf | *
|
638 | 29c1a730 | Kevin Wolf | * Before we update the L2 table to actually point to the new cluster, we
|
639 | 29c1a730 | Kevin Wolf | * need to be sure that the refcounts have been increased and COW was
|
640 | 29c1a730 | Kevin Wolf | * handled.
|
641 | 29c1a730 | Kevin Wolf | */
|
642 | 29c1a730 | Kevin Wolf | if (cow) {
|
643 | 3de0a294 | Kevin Wolf | qcow2_cache_depends_on_flush(s->l2_table_cache); |
644 | 29c1a730 | Kevin Wolf | } |
645 | 29c1a730 | Kevin Wolf | |
646 | 29c1a730 | Kevin Wolf | qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache); |
647 | 1e3e8f1a | Kevin Wolf | ret = get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index); |
648 | 1e3e8f1a | Kevin Wolf | if (ret < 0) { |
649 | 45aba42f | Kevin Wolf | goto err;
|
650 | 1e3e8f1a | Kevin Wolf | } |
651 | 29c1a730 | Kevin Wolf | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
652 | 45aba42f | Kevin Wolf | |
653 | 45aba42f | Kevin Wolf | for (i = 0; i < m->nb_clusters; i++) { |
654 | 45aba42f | Kevin Wolf | /* if two concurrent writes happen to the same unallocated cluster
|
655 | 45aba42f | Kevin Wolf | * each write allocates separate cluster and writes data concurrently.
|
656 | 45aba42f | Kevin Wolf | * The first one to complete updates l2 table with pointer to its
|
657 | 45aba42f | Kevin Wolf | * cluster the second one has to do RMW (which is done above by
|
658 | 45aba42f | Kevin Wolf | * copy_sectors()), update l2 table with its cluster pointer and free
|
659 | 45aba42f | Kevin Wolf | * old cluster. This is what this loop does */
|
660 | 45aba42f | Kevin Wolf | if(l2_table[l2_index + i] != 0) |
661 | 45aba42f | Kevin Wolf | old_cluster[j++] = l2_table[l2_index + i]; |
662 | 45aba42f | Kevin Wolf | |
663 | 45aba42f | Kevin Wolf | l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
664 | 45aba42f | Kevin Wolf | (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
665 | 45aba42f | Kevin Wolf | } |
666 | 45aba42f | Kevin Wolf | |
667 | 9f8e668e | Kevin Wolf | |
668 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
669 | c835d00f | Kevin Wolf | if (ret < 0) { |
670 | 45aba42f | Kevin Wolf | goto err;
|
671 | 4c1612d9 | Kevin Wolf | } |
672 | 45aba42f | Kevin Wolf | |
673 | 7ec5e6a4 | Kevin Wolf | /*
|
674 | 7ec5e6a4 | Kevin Wolf | * If this was a COW, we need to decrease the refcount of the old cluster.
|
675 | 7ec5e6a4 | Kevin Wolf | * Also flush bs->file to get the right order for L2 and refcount update.
|
676 | 7ec5e6a4 | Kevin Wolf | */
|
677 | 7ec5e6a4 | Kevin Wolf | if (j != 0) { |
678 | 7ec5e6a4 | Kevin Wolf | for (i = 0; i < j; i++) { |
679 | 7ec5e6a4 | Kevin Wolf | qcow2_free_any_clusters(bs, |
680 | 7ec5e6a4 | Kevin Wolf | be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
|
681 | 7ec5e6a4 | Kevin Wolf | } |
682 | 7ec5e6a4 | Kevin Wolf | } |
683 | 45aba42f | Kevin Wolf | |
684 | 45aba42f | Kevin Wolf | ret = 0;
|
685 | 45aba42f | Kevin Wolf | err:
|
686 | 45aba42f | Kevin Wolf | qemu_free(old_cluster); |
687 | 45aba42f | Kevin Wolf | return ret;
|
688 | 45aba42f | Kevin Wolf | } |
689 | 45aba42f | Kevin Wolf | |
690 | 45aba42f | Kevin Wolf | /*
|
691 | 45aba42f | Kevin Wolf | * alloc_cluster_offset
|
692 | 45aba42f | Kevin Wolf | *
|
693 | 148da7ea | Kevin Wolf | * For a given offset of the disk image, return cluster offset in qcow2 file.
|
694 | 45aba42f | Kevin Wolf | * If the offset is not found, allocate a new cluster.
|
695 | 45aba42f | Kevin Wolf | *
|
696 | 148da7ea | Kevin Wolf | * If the cluster was already allocated, m->nb_clusters is set to 0,
|
697 | 148da7ea | Kevin Wolf | * m->depends_on is set to NULL and the other fields in m are meaningless.
|
698 | 148da7ea | Kevin Wolf | *
|
699 | 148da7ea | Kevin Wolf | * If the cluster is newly allocated, m->nb_clusters is set to the number of
|
700 | 148da7ea | Kevin Wolf | * contiguous clusters that have been allocated. This may be 0 if the request
|
701 | 148da7ea | Kevin Wolf | * conflict with another write request in flight; in this case, m->depends_on
|
702 | 148da7ea | Kevin Wolf | * is set and the remaining fields of m are meaningless.
|
703 | 45aba42f | Kevin Wolf | *
|
704 | 148da7ea | Kevin Wolf | * If m->nb_clusters is non-zero, the other fields of m are valid and contain
|
705 | 148da7ea | Kevin Wolf | * information about the first allocated cluster.
|
706 | 148da7ea | Kevin Wolf | *
|
707 | 148da7ea | Kevin Wolf | * Return 0 on success and -errno in error cases
|
708 | 45aba42f | Kevin Wolf | */
|
709 | f4f0d391 | Kevin Wolf | int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
|
710 | f4f0d391 | Kevin Wolf | int n_start, int n_end, int *num, QCowL2Meta *m) |
711 | 45aba42f | Kevin Wolf | { |
712 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
713 | 45aba42f | Kevin Wolf | int l2_index, ret;
|
714 | 5d757b56 | Kevin Wolf | uint64_t l2_offset, *l2_table; |
715 | 5d757b56 | Kevin Wolf | int64_t cluster_offset; |
716 | 80ee15a6 | Kevin Wolf | unsigned int nb_clusters, i = 0; |
717 | f214978a | Kevin Wolf | QCowL2Meta *old_alloc; |
718 | 45aba42f | Kevin Wolf | |
719 | 45aba42f | Kevin Wolf | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
720 | 1e3e8f1a | Kevin Wolf | if (ret < 0) { |
721 | 148da7ea | Kevin Wolf | return ret;
|
722 | 1e3e8f1a | Kevin Wolf | } |
723 | 45aba42f | Kevin Wolf | |
724 | 45aba42f | Kevin Wolf | nb_clusters = size_to_clusters(s, n_end << 9);
|
725 | 45aba42f | Kevin Wolf | |
726 | 45aba42f | Kevin Wolf | nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
727 | 45aba42f | Kevin Wolf | |
728 | 45aba42f | Kevin Wolf | cluster_offset = be64_to_cpu(l2_table[l2_index]); |
729 | 45aba42f | Kevin Wolf | |
730 | 45aba42f | Kevin Wolf | /* We keep all QCOW_OFLAG_COPIED clusters */
|
731 | 45aba42f | Kevin Wolf | |
732 | 45aba42f | Kevin Wolf | if (cluster_offset & QCOW_OFLAG_COPIED) {
|
733 | 45aba42f | Kevin Wolf | nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
734 | 45aba42f | Kevin Wolf | &l2_table[l2_index], 0, 0); |
735 | 45aba42f | Kevin Wolf | |
736 | 45aba42f | Kevin Wolf | cluster_offset &= ~QCOW_OFLAG_COPIED; |
737 | 45aba42f | Kevin Wolf | m->nb_clusters = 0;
|
738 | 148da7ea | Kevin Wolf | m->depends_on = NULL;
|
739 | 45aba42f | Kevin Wolf | |
740 | 45aba42f | Kevin Wolf | goto out;
|
741 | 45aba42f | Kevin Wolf | } |
742 | 45aba42f | Kevin Wolf | |
743 | 45aba42f | Kevin Wolf | /* for the moment, multiple compressed clusters are not managed */
|
744 | 45aba42f | Kevin Wolf | |
745 | 45aba42f | Kevin Wolf | if (cluster_offset & QCOW_OFLAG_COMPRESSED)
|
746 | 45aba42f | Kevin Wolf | nb_clusters = 1;
|
747 | 45aba42f | Kevin Wolf | |
748 | 45aba42f | Kevin Wolf | /* how many available clusters ? */
|
749 | 45aba42f | Kevin Wolf | |
750 | 45aba42f | Kevin Wolf | while (i < nb_clusters) {
|
751 | 45aba42f | Kevin Wolf | i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
752 | 45aba42f | Kevin Wolf | &l2_table[l2_index], i, 0);
|
753 | 4805bb66 | Kevin Wolf | if ((i >= nb_clusters) || be64_to_cpu(l2_table[l2_index + i])) {
|
754 | 45aba42f | Kevin Wolf | break;
|
755 | 4805bb66 | Kevin Wolf | } |
756 | 45aba42f | Kevin Wolf | |
757 | 45aba42f | Kevin Wolf | i += count_contiguous_free_clusters(nb_clusters - i, |
758 | 45aba42f | Kevin Wolf | &l2_table[l2_index + i]); |
759 | 4805bb66 | Kevin Wolf | if (i >= nb_clusters) {
|
760 | 4805bb66 | Kevin Wolf | break;
|
761 | 4805bb66 | Kevin Wolf | } |
762 | 45aba42f | Kevin Wolf | |
763 | 45aba42f | Kevin Wolf | cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
764 | 45aba42f | Kevin Wolf | |
765 | 45aba42f | Kevin Wolf | if ((cluster_offset & QCOW_OFLAG_COPIED) ||
|
766 | 45aba42f | Kevin Wolf | (cluster_offset & QCOW_OFLAG_COMPRESSED)) |
767 | 45aba42f | Kevin Wolf | break;
|
768 | 45aba42f | Kevin Wolf | } |
769 | 4805bb66 | Kevin Wolf | assert(i <= nb_clusters); |
770 | 45aba42f | Kevin Wolf | nb_clusters = i; |
771 | 45aba42f | Kevin Wolf | |
772 | f214978a | Kevin Wolf | /*
|
773 | f214978a | Kevin Wolf | * Check if there already is an AIO write request in flight which allocates
|
774 | f214978a | Kevin Wolf | * the same cluster. In this case we need to wait until the previous
|
775 | f214978a | Kevin Wolf | * request has completed and updated the L2 table accordingly.
|
776 | f214978a | Kevin Wolf | */
|
777 | 72cf2d4f | Blue Swirl | QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { |
778 | f214978a | Kevin Wolf | |
779 | f214978a | Kevin Wolf | uint64_t end_offset = offset + nb_clusters * s->cluster_size; |
780 | f214978a | Kevin Wolf | uint64_t old_offset = old_alloc->offset; |
781 | f214978a | Kevin Wolf | uint64_t old_end_offset = old_alloc->offset + |
782 | f214978a | Kevin Wolf | old_alloc->nb_clusters * s->cluster_size; |
783 | f214978a | Kevin Wolf | |
784 | f214978a | Kevin Wolf | if (end_offset < old_offset || offset > old_end_offset) {
|
785 | f214978a | Kevin Wolf | /* No intersection */
|
786 | f214978a | Kevin Wolf | } else {
|
787 | f214978a | Kevin Wolf | if (offset < old_offset) {
|
788 | f214978a | Kevin Wolf | /* Stop at the start of a running allocation */
|
789 | f214978a | Kevin Wolf | nb_clusters = (old_offset - offset) >> s->cluster_bits; |
790 | f214978a | Kevin Wolf | } else {
|
791 | f214978a | Kevin Wolf | nb_clusters = 0;
|
792 | f214978a | Kevin Wolf | } |
793 | f214978a | Kevin Wolf | |
794 | f214978a | Kevin Wolf | if (nb_clusters == 0) { |
795 | f214978a | Kevin Wolf | /* Set dependency and wait for a callback */
|
796 | f214978a | Kevin Wolf | m->depends_on = old_alloc; |
797 | f214978a | Kevin Wolf | m->nb_clusters = 0;
|
798 | f214978a | Kevin Wolf | *num = 0;
|
799 | 29c1a730 | Kevin Wolf | ret = 0;
|
800 | 29c1a730 | Kevin Wolf | goto fail;
|
801 | f214978a | Kevin Wolf | } |
802 | f214978a | Kevin Wolf | } |
803 | f214978a | Kevin Wolf | } |
804 | f214978a | Kevin Wolf | |
805 | f214978a | Kevin Wolf | if (!nb_clusters) {
|
806 | f214978a | Kevin Wolf | abort(); |
807 | f214978a | Kevin Wolf | } |
808 | f214978a | Kevin Wolf | |
809 | 72cf2d4f | Blue Swirl | QLIST_INSERT_HEAD(&s->cluster_allocs, m, next_in_flight); |
810 | f214978a | Kevin Wolf | |
811 | 45aba42f | Kevin Wolf | /* allocate a new cluster */
|
812 | 45aba42f | Kevin Wolf | |
813 | ed6ccf0f | Kevin Wolf | cluster_offset = qcow2_alloc_clusters(bs, nb_clusters * s->cluster_size); |
814 | 5d757b56 | Kevin Wolf | if (cluster_offset < 0) { |
815 | c644db3d | Kevin Wolf | QLIST_REMOVE(m, next_in_flight); |
816 | 29c1a730 | Kevin Wolf | ret = cluster_offset; |
817 | 29c1a730 | Kevin Wolf | goto fail;
|
818 | 5d757b56 | Kevin Wolf | } |
819 | 45aba42f | Kevin Wolf | |
820 | 45aba42f | Kevin Wolf | /* save info needed for meta data update */
|
821 | 45aba42f | Kevin Wolf | m->offset = offset; |
822 | 45aba42f | Kevin Wolf | m->n_start = n_start; |
823 | 45aba42f | Kevin Wolf | m->nb_clusters = nb_clusters; |
824 | 45aba42f | Kevin Wolf | |
825 | 45aba42f | Kevin Wolf | out:
|
826 | 29c1a730 | Kevin Wolf | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
827 | 29c1a730 | Kevin Wolf | if (ret < 0) { |
828 | 29c1a730 | Kevin Wolf | return ret;
|
829 | 29c1a730 | Kevin Wolf | } |
830 | 29c1a730 | Kevin Wolf | |
831 | 45aba42f | Kevin Wolf | m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
|
832 | 148da7ea | Kevin Wolf | m->cluster_offset = cluster_offset; |
833 | 45aba42f | Kevin Wolf | |
834 | 45aba42f | Kevin Wolf | *num = m->nb_available - n_start; |
835 | 45aba42f | Kevin Wolf | |
836 | 148da7ea | Kevin Wolf | return 0; |
837 | 29c1a730 | Kevin Wolf | |
838 | 29c1a730 | Kevin Wolf | fail:
|
839 | 29c1a730 | Kevin Wolf | qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
840 | 29c1a730 | Kevin Wolf | return ret;
|
841 | 45aba42f | Kevin Wolf | } |
842 | 45aba42f | Kevin Wolf | |
843 | 45aba42f | Kevin Wolf | static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
844 | 45aba42f | Kevin Wolf | const uint8_t *buf, int buf_size) |
845 | 45aba42f | Kevin Wolf | { |
846 | 45aba42f | Kevin Wolf | z_stream strm1, *strm = &strm1; |
847 | 45aba42f | Kevin Wolf | int ret, out_len;
|
848 | 45aba42f | Kevin Wolf | |
849 | 45aba42f | Kevin Wolf | memset(strm, 0, sizeof(*strm)); |
850 | 45aba42f | Kevin Wolf | |
851 | 45aba42f | Kevin Wolf | strm->next_in = (uint8_t *)buf; |
852 | 45aba42f | Kevin Wolf | strm->avail_in = buf_size; |
853 | 45aba42f | Kevin Wolf | strm->next_out = out_buf; |
854 | 45aba42f | Kevin Wolf | strm->avail_out = out_buf_size; |
855 | 45aba42f | Kevin Wolf | |
856 | 45aba42f | Kevin Wolf | ret = inflateInit2(strm, -12);
|
857 | 45aba42f | Kevin Wolf | if (ret != Z_OK)
|
858 | 45aba42f | Kevin Wolf | return -1; |
859 | 45aba42f | Kevin Wolf | ret = inflate(strm, Z_FINISH); |
860 | 45aba42f | Kevin Wolf | out_len = strm->next_out - out_buf; |
861 | 45aba42f | Kevin Wolf | if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
862 | 45aba42f | Kevin Wolf | out_len != out_buf_size) { |
863 | 45aba42f | Kevin Wolf | inflateEnd(strm); |
864 | 45aba42f | Kevin Wolf | return -1; |
865 | 45aba42f | Kevin Wolf | } |
866 | 45aba42f | Kevin Wolf | inflateEnd(strm); |
867 | 45aba42f | Kevin Wolf | return 0; |
868 | 45aba42f | Kevin Wolf | } |
869 | 45aba42f | Kevin Wolf | |
870 | 66f82cee | Kevin Wolf | int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
|
871 | 45aba42f | Kevin Wolf | { |
872 | 66f82cee | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
873 | 45aba42f | Kevin Wolf | int ret, csize, nb_csectors, sector_offset;
|
874 | 45aba42f | Kevin Wolf | uint64_t coffset; |
875 | 45aba42f | Kevin Wolf | |
876 | 45aba42f | Kevin Wolf | coffset = cluster_offset & s->cluster_offset_mask; |
877 | 45aba42f | Kevin Wolf | if (s->cluster_cache_offset != coffset) {
|
878 | 45aba42f | Kevin Wolf | nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
|
879 | 45aba42f | Kevin Wolf | sector_offset = coffset & 511;
|
880 | 45aba42f | Kevin Wolf | csize = nb_csectors * 512 - sector_offset;
|
881 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); |
882 | 66f82cee | Kevin Wolf | ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data, nb_csectors);
|
883 | 45aba42f | Kevin Wolf | if (ret < 0) { |
884 | 8af36488 | Kevin Wolf | return ret;
|
885 | 45aba42f | Kevin Wolf | } |
886 | 45aba42f | Kevin Wolf | if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
887 | 45aba42f | Kevin Wolf | s->cluster_data + sector_offset, csize) < 0) {
|
888 | 8af36488 | Kevin Wolf | return -EIO;
|
889 | 45aba42f | Kevin Wolf | } |
890 | 45aba42f | Kevin Wolf | s->cluster_cache_offset = coffset; |
891 | 45aba42f | Kevin Wolf | } |
892 | 45aba42f | Kevin Wolf | return 0; |
893 | 45aba42f | Kevin Wolf | } |
894 | 5ea929e3 | Kevin Wolf | |
895 | 5ea929e3 | Kevin Wolf | /*
|
896 | 5ea929e3 | Kevin Wolf | * This discards as many clusters of nb_clusters as possible at once (i.e.
|
897 | 5ea929e3 | Kevin Wolf | * all clusters in the same L2 table) and returns the number of discarded
|
898 | 5ea929e3 | Kevin Wolf | * clusters.
|
899 | 5ea929e3 | Kevin Wolf | */
|
900 | 5ea929e3 | Kevin Wolf | static int discard_single_l2(BlockDriverState *bs, uint64_t offset, |
901 | 5ea929e3 | Kevin Wolf | unsigned int nb_clusters) |
902 | 5ea929e3 | Kevin Wolf | { |
903 | 5ea929e3 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
904 | 5ea929e3 | Kevin Wolf | uint64_t l2_offset, *l2_table; |
905 | 5ea929e3 | Kevin Wolf | int l2_index;
|
906 | 5ea929e3 | Kevin Wolf | int ret;
|
907 | 5ea929e3 | Kevin Wolf | int i;
|
908 | 5ea929e3 | Kevin Wolf | |
909 | 5ea929e3 | Kevin Wolf | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
910 | 5ea929e3 | Kevin Wolf | if (ret < 0) { |
911 | 5ea929e3 | Kevin Wolf | return ret;
|
912 | 5ea929e3 | Kevin Wolf | } |
913 | 5ea929e3 | Kevin Wolf | |
914 | 5ea929e3 | Kevin Wolf | /* Limit nb_clusters to one L2 table */
|
915 | 5ea929e3 | Kevin Wolf | nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
916 | 5ea929e3 | Kevin Wolf | |
917 | 5ea929e3 | Kevin Wolf | for (i = 0; i < nb_clusters; i++) { |
918 | 5ea929e3 | Kevin Wolf | uint64_t old_offset; |
919 | 5ea929e3 | Kevin Wolf | |
920 | 5ea929e3 | Kevin Wolf | old_offset = be64_to_cpu(l2_table[l2_index + i]); |
921 | 5ea929e3 | Kevin Wolf | old_offset &= ~QCOW_OFLAG_COPIED; |
922 | 5ea929e3 | Kevin Wolf | |
923 | 5ea929e3 | Kevin Wolf | if (old_offset == 0) { |
924 | 5ea929e3 | Kevin Wolf | continue;
|
925 | 5ea929e3 | Kevin Wolf | } |
926 | 5ea929e3 | Kevin Wolf | |
927 | 5ea929e3 | Kevin Wolf | /* First remove L2 entries */
|
928 | 5ea929e3 | Kevin Wolf | qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); |
929 | 5ea929e3 | Kevin Wolf | l2_table[l2_index + i] = cpu_to_be64(0);
|
930 | 5ea929e3 | Kevin Wolf | |
931 | 5ea929e3 | Kevin Wolf | /* Then decrease the refcount */
|
932 | 5ea929e3 | Kevin Wolf | qcow2_free_any_clusters(bs, old_offset, 1);
|
933 | 5ea929e3 | Kevin Wolf | } |
934 | 5ea929e3 | Kevin Wolf | |
935 | 5ea929e3 | Kevin Wolf | ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table);
|
936 | 5ea929e3 | Kevin Wolf | if (ret < 0) { |
937 | 5ea929e3 | Kevin Wolf | return ret;
|
938 | 5ea929e3 | Kevin Wolf | } |
939 | 5ea929e3 | Kevin Wolf | |
940 | 5ea929e3 | Kevin Wolf | return nb_clusters;
|
941 | 5ea929e3 | Kevin Wolf | } |
942 | 5ea929e3 | Kevin Wolf | |
943 | 5ea929e3 | Kevin Wolf | int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
|
944 | 5ea929e3 | Kevin Wolf | int nb_sectors)
|
945 | 5ea929e3 | Kevin Wolf | { |
946 | 5ea929e3 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
947 | 5ea929e3 | Kevin Wolf | uint64_t end_offset; |
948 | 5ea929e3 | Kevin Wolf | unsigned int nb_clusters; |
949 | 5ea929e3 | Kevin Wolf | int ret;
|
950 | 5ea929e3 | Kevin Wolf | |
951 | 5ea929e3 | Kevin Wolf | end_offset = offset + (nb_sectors << BDRV_SECTOR_BITS); |
952 | 5ea929e3 | Kevin Wolf | |
953 | 5ea929e3 | Kevin Wolf | /* Round start up and end down */
|
954 | 5ea929e3 | Kevin Wolf | offset = align_offset(offset, s->cluster_size); |
955 | 5ea929e3 | Kevin Wolf | end_offset &= ~(s->cluster_size - 1);
|
956 | 5ea929e3 | Kevin Wolf | |
957 | 5ea929e3 | Kevin Wolf | if (offset > end_offset) {
|
958 | 5ea929e3 | Kevin Wolf | return 0; |
959 | 5ea929e3 | Kevin Wolf | } |
960 | 5ea929e3 | Kevin Wolf | |
961 | 5ea929e3 | Kevin Wolf | nb_clusters = size_to_clusters(s, end_offset - offset); |
962 | 5ea929e3 | Kevin Wolf | |
963 | 5ea929e3 | Kevin Wolf | /* Each L2 table is handled by its own loop iteration */
|
964 | 5ea929e3 | Kevin Wolf | while (nb_clusters > 0) { |
965 | 5ea929e3 | Kevin Wolf | ret = discard_single_l2(bs, offset, nb_clusters); |
966 | 5ea929e3 | Kevin Wolf | if (ret < 0) { |
967 | 5ea929e3 | Kevin Wolf | return ret;
|
968 | 5ea929e3 | Kevin Wolf | } |
969 | 5ea929e3 | Kevin Wolf | |
970 | 5ea929e3 | Kevin Wolf | nb_clusters -= ret; |
971 | 5ea929e3 | Kevin Wolf | offset += (ret * s->cluster_size); |
972 | 5ea929e3 | Kevin Wolf | } |
973 | 5ea929e3 | Kevin Wolf | |
974 | 5ea929e3 | Kevin Wolf | return 0; |
975 | 5ea929e3 | Kevin Wolf | } |