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1 /* |
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2 * Block driver for the QCOW version 2 format |
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3 * |
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4 * Copyright (c) 2004-2006 Fabrice Bellard |
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5 * |
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6 * Permission is hereby granted, free of charge, to any person obtaining a copy |
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7 * of this software and associated documentation files (the "Software"), to deal |
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8 * in the Software without restriction, including without limitation the rights |
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9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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10 * copies of the Software, and to permit persons to whom the Software is |
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11 * furnished to do so, subject to the following conditions: |
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12 * |
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13 * The above copyright notice and this permission notice shall be included in |
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14 * all copies or substantial portions of the Software. |
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15 * |
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16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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22 * THE SOFTWARE. |
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23 */ |
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24 #include "qemu-common.h" |
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25 #include "block_int.h" |
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26 #include <zlib.h> |
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27 #include "aes.h" |
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28 #include <assert.h> |
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29 |
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30 /* |
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31 Differences with QCOW: |
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32 |
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33 - Support for multiple incremental snapshots. |
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34 - Memory management by reference counts. |
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35 - Clusters which have a reference count of one have the bit |
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36 QCOW_OFLAG_COPIED to optimize write performance. |
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37 - Size of compressed clusters is stored in sectors to reduce bit usage |
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38 in the cluster offsets. |
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39 - Support for storing additional data (such as the VM state) in the |
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40 snapshots. |
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41 - If a backing store is used, the cluster size is not constrained |
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42 (could be backported to QCOW). |
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43 - L2 tables have always a size of one cluster. |
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44 */ |
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45 |
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46 //#define DEBUG_ALLOC |
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47 //#define DEBUG_ALLOC2 |
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48 |
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49 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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50 #define QCOW_VERSION 2 |
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51 |
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52 #define QCOW_CRYPT_NONE 0 |
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53 #define QCOW_CRYPT_AES 1 |
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54 |
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55 #define QCOW_MAX_CRYPT_CLUSTERS 32 |
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56 |
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57 /* indicate that the refcount of the referenced cluster is exactly one. */ |
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58 #define QCOW_OFLAG_COPIED (1LL << 63) |
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59 /* indicate that the cluster is compressed (they never have the copied flag) */ |
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60 #define QCOW_OFLAG_COMPRESSED (1LL << 62) |
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61 |
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62 #define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ |
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63 |
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64 typedef struct QCowHeader { |
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65 uint32_t magic; |
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66 uint32_t version; |
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67 uint64_t backing_file_offset; |
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68 uint32_t backing_file_size; |
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69 uint32_t cluster_bits; |
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70 uint64_t size; /* in bytes */ |
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71 uint32_t crypt_method; |
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72 uint32_t l1_size; /* XXX: save number of clusters instead ? */ |
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73 uint64_t l1_table_offset; |
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74 uint64_t refcount_table_offset; |
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75 uint32_t refcount_table_clusters; |
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76 uint32_t nb_snapshots; |
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77 uint64_t snapshots_offset; |
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78 } QCowHeader; |
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79 |
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80 typedef struct __attribute__((packed)) QCowSnapshotHeader { |
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81 /* header is 8 byte aligned */ |
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82 uint64_t l1_table_offset; |
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83 |
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84 uint32_t l1_size; |
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85 uint16_t id_str_size; |
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86 uint16_t name_size; |
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87 |
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88 uint32_t date_sec; |
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89 uint32_t date_nsec; |
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90 |
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91 uint64_t vm_clock_nsec; |
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92 |
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93 uint32_t vm_state_size; |
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94 uint32_t extra_data_size; /* for extension */ |
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95 /* extra data follows */ |
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96 /* id_str follows */ |
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97 /* name follows */ |
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98 } QCowSnapshotHeader; |
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99 |
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100 #define L2_CACHE_SIZE 16 |
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101 |
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102 typedef struct QCowSnapshot { |
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103 uint64_t l1_table_offset; |
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104 uint32_t l1_size; |
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105 char *id_str; |
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106 char *name; |
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107 uint32_t vm_state_size; |
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108 uint32_t date_sec; |
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109 uint32_t date_nsec; |
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110 uint64_t vm_clock_nsec; |
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111 } QCowSnapshot; |
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112 |
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113 typedef struct BDRVQcowState { |
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114 BlockDriverState *hd; |
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115 int cluster_bits; |
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116 int cluster_size; |
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117 int cluster_sectors; |
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118 int l2_bits; |
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119 int l2_size; |
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120 int l1_size; |
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121 int l1_vm_state_index; |
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122 int csize_shift; |
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123 int csize_mask; |
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124 uint64_t cluster_offset_mask; |
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125 uint64_t l1_table_offset; |
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126 uint64_t *l1_table; |
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127 uint64_t *l2_cache; |
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128 uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
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129 uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
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130 uint8_t *cluster_cache; |
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131 uint8_t *cluster_data; |
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132 uint64_t cluster_cache_offset; |
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133 |
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134 uint64_t *refcount_table; |
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135 uint64_t refcount_table_offset; |
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136 uint32_t refcount_table_size; |
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137 uint64_t refcount_block_cache_offset; |
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138 uint16_t *refcount_block_cache; |
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139 int64_t free_cluster_index; |
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140 int64_t free_byte_offset; |
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141 |
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142 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ |
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143 uint32_t crypt_method_header; |
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144 AES_KEY aes_encrypt_key; |
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145 AES_KEY aes_decrypt_key; |
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146 uint64_t snapshots_offset; |
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147 int snapshots_size; |
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148 int nb_snapshots; |
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149 QCowSnapshot *snapshots; |
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150 } BDRVQcowState; |
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151 |
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152 static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
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153 static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
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154 uint8_t *buf, int nb_sectors); |
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155 static int qcow_read_snapshots(BlockDriverState *bs); |
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156 static void qcow_free_snapshots(BlockDriverState *bs); |
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157 static int refcount_init(BlockDriverState *bs); |
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158 static void refcount_close(BlockDriverState *bs); |
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159 static int get_refcount(BlockDriverState *bs, int64_t cluster_index); |
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160 static int update_cluster_refcount(BlockDriverState *bs, |
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161 int64_t cluster_index, |
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162 int addend); |
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163 static void update_refcount(BlockDriverState *bs, |
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164 int64_t offset, int64_t length, |
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165 int addend); |
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166 static int64_t alloc_clusters(BlockDriverState *bs, int64_t size); |
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167 static int64_t alloc_bytes(BlockDriverState *bs, int size); |
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168 static void free_clusters(BlockDriverState *bs, |
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169 int64_t offset, int64_t size); |
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170 #ifdef DEBUG_ALLOC |
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171 static void check_refcounts(BlockDriverState *bs); |
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172 #endif |
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173 |
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174 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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175 { |
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176 const QCowHeader *cow_header = (const void *)buf; |
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177 |
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178 if (buf_size >= sizeof(QCowHeader) && |
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179 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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180 be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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181 return 100; |
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182 else |
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183 return 0; |
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184 } |
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185 |
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186 static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
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187 { |
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188 BDRVQcowState *s = bs->opaque; |
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189 int len, i, shift, ret; |
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190 QCowHeader header; |
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191 |
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192 /* Performance is terrible right now with cache=writethrough due mainly |
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193 * to reference count updates. If the user does not explicitly specify |
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194 * a caching type, force to writeback caching. |
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195 */ |
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196 if ((flags & BDRV_O_CACHE_DEF)) { |
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197 flags |= BDRV_O_CACHE_WB; |
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198 flags &= ~BDRV_O_CACHE_DEF; |
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199 } |
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200 ret = bdrv_file_open(&s->hd, filename, flags); |
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201 if (ret < 0) |
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202 return ret; |
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203 if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
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204 goto fail; |
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205 be32_to_cpus(&header.magic); |
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206 be32_to_cpus(&header.version); |
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207 be64_to_cpus(&header.backing_file_offset); |
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208 be32_to_cpus(&header.backing_file_size); |
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209 be64_to_cpus(&header.size); |
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210 be32_to_cpus(&header.cluster_bits); |
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211 be32_to_cpus(&header.crypt_method); |
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212 be64_to_cpus(&header.l1_table_offset); |
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213 be32_to_cpus(&header.l1_size); |
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214 be64_to_cpus(&header.refcount_table_offset); |
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215 be32_to_cpus(&header.refcount_table_clusters); |
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216 be64_to_cpus(&header.snapshots_offset); |
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217 be32_to_cpus(&header.nb_snapshots); |
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218 |
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219 if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) |
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220 goto fail; |
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221 if (header.size <= 1 || |
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222 header.cluster_bits < 9 || |
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223 header.cluster_bits > 16) |
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224 goto fail; |
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225 if (header.crypt_method > QCOW_CRYPT_AES) |
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226 goto fail; |
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227 s->crypt_method_header = header.crypt_method; |
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228 if (s->crypt_method_header) |
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229 bs->encrypted = 1; |
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230 s->cluster_bits = header.cluster_bits; |
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231 s->cluster_size = 1 << s->cluster_bits; |
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232 s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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233 s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ |
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234 s->l2_size = 1 << s->l2_bits; |
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235 bs->total_sectors = header.size / 512; |
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236 s->csize_shift = (62 - (s->cluster_bits - 8)); |
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237 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
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238 s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
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239 s->refcount_table_offset = header.refcount_table_offset; |
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240 s->refcount_table_size = |
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241 header.refcount_table_clusters << (s->cluster_bits - 3); |
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242 |
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243 s->snapshots_offset = header.snapshots_offset; |
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244 s->nb_snapshots = header.nb_snapshots; |
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245 |
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246 /* read the level 1 table */ |
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247 s->l1_size = header.l1_size; |
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248 shift = s->cluster_bits + s->l2_bits; |
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249 s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; |
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250 /* the L1 table must contain at least enough entries to put |
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251 header.size bytes */ |
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252 if (s->l1_size < s->l1_vm_state_index) |
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253 goto fail; |
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254 s->l1_table_offset = header.l1_table_offset; |
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255 s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t)); |
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256 if (!s->l1_table) |
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257 goto fail; |
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258 if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
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259 s->l1_size * sizeof(uint64_t)) |
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260 goto fail; |
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261 for(i = 0;i < s->l1_size; i++) { |
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262 be64_to_cpus(&s->l1_table[i]); |
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263 } |
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264 /* alloc L2 cache */ |
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265 s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
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266 if (!s->l2_cache) |
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267 goto fail; |
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268 s->cluster_cache = qemu_malloc(s->cluster_size); |
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269 if (!s->cluster_cache) |
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270 goto fail; |
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271 /* one more sector for decompressed data alignment */ |
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272 s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
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273 + 512); |
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274 if (!s->cluster_data) |
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275 goto fail; |
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276 s->cluster_cache_offset = -1; |
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277 |
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278 if (refcount_init(bs) < 0) |
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279 goto fail; |
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280 |
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281 /* read the backing file name */ |
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282 if (header.backing_file_offset != 0) { |
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283 len = header.backing_file_size; |
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284 if (len > 1023) |
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285 len = 1023; |
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286 if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) |
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287 goto fail; |
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288 bs->backing_file[len] = '\0'; |
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289 } |
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290 if (qcow_read_snapshots(bs) < 0) |
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291 goto fail; |
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292 |
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293 #ifdef DEBUG_ALLOC |
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294 check_refcounts(bs); |
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295 #endif |
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296 return 0; |
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297 |
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298 fail: |
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299 qcow_free_snapshots(bs); |
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300 refcount_close(bs); |
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301 qemu_free(s->l1_table); |
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302 qemu_free(s->l2_cache); |
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303 qemu_free(s->cluster_cache); |
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304 qemu_free(s->cluster_data); |
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305 bdrv_delete(s->hd); |
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306 return -1; |
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307 } |
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308 |
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309 static int qcow_set_key(BlockDriverState *bs, const char *key) |
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310 { |
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311 BDRVQcowState *s = bs->opaque; |
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312 uint8_t keybuf[16]; |
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313 int len, i; |
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314 |
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315 memset(keybuf, 0, 16); |
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316 len = strlen(key); |
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317 if (len > 16) |
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318 len = 16; |
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319 /* XXX: we could compress the chars to 7 bits to increase |
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320 entropy */ |
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321 for(i = 0;i < len;i++) { |
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322 keybuf[i] = key[i]; |
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323 } |
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324 s->crypt_method = s->crypt_method_header; |
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325 |
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326 if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
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327 return -1; |
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328 if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
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329 return -1; |
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330 #if 0 |
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331 /* test */ |
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332 { |
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333 uint8_t in[16]; |
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334 uint8_t out[16]; |
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335 uint8_t tmp[16]; |
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336 for(i=0;i<16;i++) |
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337 in[i] = i; |
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338 AES_encrypt(in, tmp, &s->aes_encrypt_key); |
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339 AES_decrypt(tmp, out, &s->aes_decrypt_key); |
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340 for(i = 0; i < 16; i++) |
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341 printf(" %02x", tmp[i]); |
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342 printf("\n"); |
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343 for(i = 0; i < 16; i++) |
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344 printf(" %02x", out[i]); |
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345 printf("\n"); |
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346 } |
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347 #endif |
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348 return 0; |
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349 } |
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350 |
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351 /* The crypt function is compatible with the linux cryptoloop |
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352 algorithm for < 4 GB images. NOTE: out_buf == in_buf is |
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353 supported */ |
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354 static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
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355 uint8_t *out_buf, const uint8_t *in_buf, |
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356 int nb_sectors, int enc, |
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357 const AES_KEY *key) |
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358 { |
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359 union { |
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360 uint64_t ll[2]; |
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361 uint8_t b[16]; |
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362 } ivec; |
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363 int i; |
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364 |
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365 for(i = 0; i < nb_sectors; i++) { |
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366 ivec.ll[0] = cpu_to_le64(sector_num); |
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367 ivec.ll[1] = 0; |
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368 AES_cbc_encrypt(in_buf, out_buf, 512, key, |
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369 ivec.b, enc); |
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370 sector_num++; |
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371 in_buf += 512; |
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372 out_buf += 512; |
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373 } |
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374 } |
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375 |
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376 static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
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377 uint64_t cluster_offset, int n_start, int n_end) |
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378 { |
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379 BDRVQcowState *s = bs->opaque; |
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380 int n, ret; |
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381 |
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382 n = n_end - n_start; |
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383 if (n <= 0) |
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384 return 0; |
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385 ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
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386 if (ret < 0) |
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387 return ret; |
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388 if (s->crypt_method) { |
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389 encrypt_sectors(s, start_sect + n_start, |
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390 s->cluster_data, |
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391 s->cluster_data, n, 1, |
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392 &s->aes_encrypt_key); |
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393 } |
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394 ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start, |
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395 s->cluster_data, n); |
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396 if (ret < 0) |
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397 return ret; |
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398 return 0; |
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399 } |
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400 |
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401 static void l2_cache_reset(BlockDriverState *bs) |
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402 { |
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403 BDRVQcowState *s = bs->opaque; |
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404 |
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405 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
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406 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
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407 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
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408 } |
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409 |
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410 static inline int l2_cache_new_entry(BlockDriverState *bs) |
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411 { |
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412 BDRVQcowState *s = bs->opaque; |
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413 uint32_t min_count; |
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414 int min_index, i; |
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415 |
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416 /* find a new entry in the least used one */ |
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417 min_index = 0; |
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418 min_count = 0xffffffff; |
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419 for(i = 0; i < L2_CACHE_SIZE; i++) { |
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420 if (s->l2_cache_counts[i] < min_count) { |
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421 min_count = s->l2_cache_counts[i]; |
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422 min_index = i; |
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423 } |
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424 } |
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425 return min_index; |
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426 } |
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427 |
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428 static int64_t align_offset(int64_t offset, int n) |
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429 { |
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430 offset = (offset + n - 1) & ~(n - 1); |
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431 return offset; |
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432 } |
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433 |
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434 static int grow_l1_table(BlockDriverState *bs, int min_size) |
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435 { |
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436 BDRVQcowState *s = bs->opaque; |
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437 int new_l1_size, new_l1_size2, ret, i; |
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438 uint64_t *new_l1_table; |
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439 uint64_t new_l1_table_offset; |
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440 uint8_t data[12]; |
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441 |
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442 new_l1_size = s->l1_size; |
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443 if (min_size <= new_l1_size) |
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444 return 0; |
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445 while (min_size > new_l1_size) { |
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446 new_l1_size = (new_l1_size * 3 + 1) / 2; |
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447 } |
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448 #ifdef DEBUG_ALLOC2 |
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449 printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size); |
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450 #endif |
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451 |
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452 new_l1_size2 = sizeof(uint64_t) * new_l1_size; |
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453 new_l1_table = qemu_mallocz(new_l1_size2); |
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454 if (!new_l1_table) |
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455 return -ENOMEM; |
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456 memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); |
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457 |
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458 /* write new table (align to cluster) */ |
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459 new_l1_table_offset = alloc_clusters(bs, new_l1_size2); |
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460 |
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461 for(i = 0; i < s->l1_size; i++) |
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462 new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
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463 ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2); |
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464 if (ret != new_l1_size2) |
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465 goto fail; |
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466 for(i = 0; i < s->l1_size; i++) |
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467 new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
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468 |
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469 /* set new table */ |
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470 cpu_to_be32w((uint32_t*)data, new_l1_size); |
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471 cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset); |
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472 if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data, |
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473 sizeof(data)) != sizeof(data)) |
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474 goto fail; |
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475 qemu_free(s->l1_table); |
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476 free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t)); |
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477 s->l1_table_offset = new_l1_table_offset; |
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478 s->l1_table = new_l1_table; |
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479 s->l1_size = new_l1_size; |
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480 return 0; |
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481 fail: |
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482 qemu_free(s->l1_table); |
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483 return -EIO; |
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484 } |
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485 |
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486 /* |
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487 * seek_l2_table |
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488 * |
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489 * seek l2_offset in the l2_cache table |
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490 * if not found, return NULL, |
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491 * if found, |
|
492 * increments the l2 cache hit count of the entry, |
|
493 * if counter overflow, divide by two all counters |
|
494 * return the pointer to the l2 cache entry |
|
495 * |
|
496 */ |
|
497 |
|
498 static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset) |
|
499 { |
|
500 int i, j; |
|
501 |
|
502 for(i = 0; i < L2_CACHE_SIZE; i++) { |
|
503 if (l2_offset == s->l2_cache_offsets[i]) { |
|
504 /* increment the hit count */ |
|
505 if (++s->l2_cache_counts[i] == 0xffffffff) { |
|
506 for(j = 0; j < L2_CACHE_SIZE; j++) { |
|
507 s->l2_cache_counts[j] >>= 1; |
|
508 } |
|
509 } |
|
510 return s->l2_cache + (i << s->l2_bits); |
|
511 } |
|
512 } |
|
513 return NULL; |
|
514 } |
|
515 |
|
516 /* |
|
517 * l2_load |
|
518 * |
|
519 * Loads a L2 table into memory. If the table is in the cache, the cache |
|
520 * is used; otherwise the L2 table is loaded from the image file. |
|
521 * |
|
522 * Returns a pointer to the L2 table on success, or NULL if the read from |
|
523 * the image file failed. |
|
524 */ |
|
525 |
|
526 static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset) |
|
527 { |
|
528 BDRVQcowState *s = bs->opaque; |
|
529 int min_index; |
|
530 uint64_t *l2_table; |
|
531 |
|
532 /* seek if the table for the given offset is in the cache */ |
|
533 |
|
534 l2_table = seek_l2_table(s, l2_offset); |
|
535 if (l2_table != NULL) |
|
536 return l2_table; |
|
537 |
|
538 /* not found: load a new entry in the least used one */ |
|
539 |
|
540 min_index = l2_cache_new_entry(bs); |
|
541 l2_table = s->l2_cache + (min_index << s->l2_bits); |
|
542 if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
|
543 s->l2_size * sizeof(uint64_t)) |
|
544 return NULL; |
|
545 s->l2_cache_offsets[min_index] = l2_offset; |
|
546 s->l2_cache_counts[min_index] = 1; |
|
547 |
|
548 return l2_table; |
|
549 } |
|
550 |
|
551 /* |
|
552 * l2_allocate |
|
553 * |
|
554 * Allocate a new l2 entry in the file. If l1_index points to an already |
|
555 * used entry in the L2 table (i.e. we are doing a copy on write for the L2 |
|
556 * table) copy the contents of the old L2 table into the newly allocated one. |
|
557 * Otherwise the new table is initialized with zeros. |
|
558 * |
|
559 */ |
|
560 |
|
561 static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index) |
|
562 { |
|
563 BDRVQcowState *s = bs->opaque; |
|
564 int min_index; |
|
565 uint64_t old_l2_offset, tmp; |
|
566 uint64_t *l2_table, l2_offset; |
|
567 |
|
568 old_l2_offset = s->l1_table[l1_index]; |
|
569 |
|
570 /* allocate a new l2 entry */ |
|
571 |
|
572 l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t)); |
|
573 |
|
574 /* update the L1 entry */ |
|
575 |
|
576 s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
|
577 |
|
578 tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED); |
|
579 if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
|
580 &tmp, sizeof(tmp)) != sizeof(tmp)) |
|
581 return NULL; |
|
582 |
|
583 /* allocate a new entry in the l2 cache */ |
|
584 |
|
585 min_index = l2_cache_new_entry(bs); |
|
586 l2_table = s->l2_cache + (min_index << s->l2_bits); |
|
587 |
|
588 if (old_l2_offset == 0) { |
|
589 /* if there was no old l2 table, clear the new table */ |
|
590 memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
|
591 } else { |
|
592 /* if there was an old l2 table, read it from the disk */ |
|
593 if (bdrv_pread(s->hd, old_l2_offset, |
|
594 l2_table, s->l2_size * sizeof(uint64_t)) != |
|
595 s->l2_size * sizeof(uint64_t)) |
|
596 return NULL; |
|
597 } |
|
598 /* write the l2 table to the file */ |
|
599 if (bdrv_pwrite(s->hd, l2_offset, |
|
600 l2_table, s->l2_size * sizeof(uint64_t)) != |
|
601 s->l2_size * sizeof(uint64_t)) |
|
602 return NULL; |
|
603 |
|
604 /* update the l2 cache entry */ |
|
605 |
|
606 s->l2_cache_offsets[min_index] = l2_offset; |
|
607 s->l2_cache_counts[min_index] = 1; |
|
608 |
|
609 return l2_table; |
|
610 } |
|
611 |
|
612 static int size_to_clusters(BDRVQcowState *s, int64_t size) |
|
613 { |
|
614 return (size + (s->cluster_size - 1)) >> s->cluster_bits; |
|
615 } |
|
616 |
|
617 static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
|
618 uint64_t *l2_table, uint64_t mask) |
|
619 { |
|
620 int i; |
|
621 uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask; |
|
622 |
|
623 for (i = 0; i < nb_clusters; i++) |
|
624 if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask)) |
|
625 break; |
|
626 |
|
627 return i; |
|
628 } |
|
629 |
|
630 static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
|
631 { |
|
632 int i = 0; |
|
633 |
|
634 while(nb_clusters-- && l2_table[i] == 0) |
|
635 i++; |
|
636 |
|
637 return i; |
|
638 } |
|
639 |
|
640 /* |
|
641 * get_cluster_offset |
|
642 * |
|
643 * For a given offset of the disk image, return cluster offset in |
|
644 * qcow2 file. |
|
645 * |
|
646 * on entry, *num is the number of contiguous clusters we'd like to |
|
647 * access following offset. |
|
648 * |
|
649 * on exit, *num is the number of contiguous clusters we can read. |
|
650 * |
|
651 * Return 1, if the offset is found |
|
652 * Return 0, otherwise. |
|
653 * |
|
654 */ |
|
655 |
|
656 static uint64_t get_cluster_offset(BlockDriverState *bs, |
|
657 uint64_t offset, int *num) |
|
658 { |
|
659 BDRVQcowState *s = bs->opaque; |
|
660 int l1_index, l2_index; |
|
661 uint64_t l2_offset, *l2_table, cluster_offset; |
|
662 int l1_bits, c; |
|
663 int index_in_cluster, nb_available, nb_needed, nb_clusters; |
|
664 |
|
665 index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
|
666 nb_needed = *num + index_in_cluster; |
|
667 |
|
668 l1_bits = s->l2_bits + s->cluster_bits; |
|
669 |
|
670 /* compute how many bytes there are between the offset and |
|
671 * the end of the l1 entry |
|
672 */ |
|
673 |
|
674 nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1)); |
|
675 |
|
676 /* compute the number of available sectors */ |
|
677 |
|
678 nb_available = (nb_available >> 9) + index_in_cluster; |
|
679 |
|
680 cluster_offset = 0; |
|
681 |
|
682 /* seek the the l2 offset in the l1 table */ |
|
683 |
|
684 l1_index = offset >> l1_bits; |
|
685 if (l1_index >= s->l1_size) |
|
686 goto out; |
|
687 |
|
688 l2_offset = s->l1_table[l1_index]; |
|
689 |
|
690 /* seek the l2 table of the given l2 offset */ |
|
691 |
|
692 if (!l2_offset) |
|
693 goto out; |
|
694 |
|
695 /* load the l2 table in memory */ |
|
696 |
|
697 l2_offset &= ~QCOW_OFLAG_COPIED; |
|
698 l2_table = l2_load(bs, l2_offset); |
|
699 if (l2_table == NULL) |
|
700 return 0; |
|
701 |
|
702 /* find the cluster offset for the given disk offset */ |
|
703 |
|
704 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); |
|
705 cluster_offset = be64_to_cpu(l2_table[l2_index]); |
|
706 nb_clusters = size_to_clusters(s, nb_needed << 9); |
|
707 |
|
708 if (!cluster_offset) { |
|
709 /* how many empty clusters ? */ |
|
710 c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
|
711 } else { |
|
712 /* how many allocated clusters ? */ |
|
713 c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
|
714 &l2_table[l2_index], QCOW_OFLAG_COPIED); |
|
715 } |
|
716 |
|
717 nb_available = (c * s->cluster_sectors); |
|
718 out: |
|
719 if (nb_available > nb_needed) |
|
720 nb_available = nb_needed; |
|
721 |
|
722 *num = nb_available - index_in_cluster; |
|
723 |
|
724 return cluster_offset & ~QCOW_OFLAG_COPIED; |
|
725 } |
|
726 |
|
727 /* |
|
728 * free_any_clusters |
|
729 * |
|
730 * free clusters according to its type: compressed or not |
|
731 * |
|
732 */ |
|
733 |
|
734 static void free_any_clusters(BlockDriverState *bs, |
|
735 uint64_t cluster_offset, int nb_clusters) |
|
736 { |
|
737 BDRVQcowState *s = bs->opaque; |
|
738 |
|
739 /* free the cluster */ |
|
740 |
|
741 if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
|
742 int nb_csectors; |
|
743 nb_csectors = ((cluster_offset >> s->csize_shift) & |
|
744 s->csize_mask) + 1; |
|
745 free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511, |
|
746 nb_csectors * 512); |
|
747 return; |
|
748 } |
|
749 |
|
750 free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
|
751 |
|
752 return; |
|
753 } |
|
754 |
|
755 /* |
|
756 * get_cluster_table |
|
757 * |
|
758 * for a given disk offset, load (and allocate if needed) |
|
759 * the l2 table. |
|
760 * |
|
761 * the l2 table offset in the qcow2 file and the cluster index |
|
762 * in the l2 table are given to the caller. |
|
763 * |
|
764 */ |
|
765 |
|
766 static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
|
767 uint64_t **new_l2_table, |
|
768 uint64_t *new_l2_offset, |
|
769 int *new_l2_index) |
|
770 { |
|
771 BDRVQcowState *s = bs->opaque; |
|
772 int l1_index, l2_index, ret; |
|
773 uint64_t l2_offset, *l2_table; |
|
774 |
|
775 /* seek the the l2 offset in the l1 table */ |
|
776 |
|
777 l1_index = offset >> (s->l2_bits + s->cluster_bits); |
|
778 if (l1_index >= s->l1_size) { |
|
779 ret = grow_l1_table(bs, l1_index + 1); |
|
780 if (ret < 0) |
|
781 return 0; |
|
782 } |
|
783 l2_offset = s->l1_table[l1_index]; |
|
784 |
|
785 /* seek the l2 table of the given l2 offset */ |
|
786 |
|
787 if (l2_offset & QCOW_OFLAG_COPIED) { |
|
788 /* load the l2 table in memory */ |
|
789 l2_offset &= ~QCOW_OFLAG_COPIED; |
|
790 l2_table = l2_load(bs, l2_offset); |
|
791 if (l2_table == NULL) |
|
792 return 0; |
|
793 } else { |
|
794 if (l2_offset) |
|
795 free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t)); |
|
796 l2_table = l2_allocate(bs, l1_index); |
|
797 if (l2_table == NULL) |
|
798 return 0; |
|
799 l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
|
800 } |
|
801 |
|
802 /* find the cluster offset for the given disk offset */ |
|
803 |
|
804 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); |
|
805 |
|
806 *new_l2_table = l2_table; |
|
807 *new_l2_offset = l2_offset; |
|
808 *new_l2_index = l2_index; |
|
809 |
|
810 return 1; |
|
811 } |
|
812 |
|
813 /* |
|
814 * alloc_compressed_cluster_offset |
|
815 * |
|
816 * For a given offset of the disk image, return cluster offset in |
|
817 * qcow2 file. |
|
818 * |
|
819 * If the offset is not found, allocate a new compressed cluster. |
|
820 * |
|
821 * Return the cluster offset if successful, |
|
822 * Return 0, otherwise. |
|
823 * |
|
824 */ |
|
825 |
|
826 static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs, |
|
827 uint64_t offset, |
|
828 int compressed_size) |
|
829 { |
|
830 BDRVQcowState *s = bs->opaque; |
|
831 int l2_index, ret; |
|
832 uint64_t l2_offset, *l2_table, cluster_offset; |
|
833 int nb_csectors; |
|
834 |
|
835 ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
|
836 if (ret == 0) |
|
837 return 0; |
|
838 |
|
839 cluster_offset = be64_to_cpu(l2_table[l2_index]); |
|
840 if (cluster_offset & QCOW_OFLAG_COPIED) |
|
841 return cluster_offset & ~QCOW_OFLAG_COPIED; |
|
842 |
|
843 if (cluster_offset) |
|
844 free_any_clusters(bs, cluster_offset, 1); |
|
845 |
|
846 cluster_offset = alloc_bytes(bs, compressed_size); |
|
847 nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
|
848 (cluster_offset >> 9); |
|
849 |
|
850 cluster_offset |= QCOW_OFLAG_COMPRESSED | |
|
851 ((uint64_t)nb_csectors << s->csize_shift); |
|
852 |
|
853 /* update L2 table */ |
|
854 |
|
855 /* compressed clusters never have the copied flag */ |
|
856 |
|
857 l2_table[l2_index] = cpu_to_be64(cluster_offset); |
|
858 if (bdrv_pwrite(s->hd, |
|
859 l2_offset + l2_index * sizeof(uint64_t), |
|
860 l2_table + l2_index, |
|
861 sizeof(uint64_t)) != sizeof(uint64_t)) |
|
862 return 0; |
|
863 |
|
864 return cluster_offset; |
|
865 } |
|
866 |
|
867 typedef struct QCowL2Meta |
|
868 { |
|
869 uint64_t offset; |
|
870 int n_start; |
|
871 int nb_available; |
|
872 int nb_clusters; |
|
873 } QCowL2Meta; |
|
874 |
|
875 static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset, |
|
876 QCowL2Meta *m) |
|
877 { |
|
878 BDRVQcowState *s = bs->opaque; |
|
879 int i, j = 0, l2_index, ret; |
|
880 uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
|
881 |
|
882 if (m->nb_clusters == 0) |
|
883 return 0; |
|
884 |
|
885 if (!(old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t)))) |
|
886 return -ENOMEM; |
|
887 |
|
888 /* copy content of unmodified sectors */ |
|
889 start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
|
890 if (m->n_start) { |
|
891 ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start); |
|
892 if (ret < 0) |
|
893 goto err; |
|
894 } |
|
895 |
|
896 if (m->nb_available & (s->cluster_sectors - 1)) { |
|
897 uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1); |
|
898 ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9), |
|
899 m->nb_available - end, s->cluster_sectors); |
|
900 if (ret < 0) |
|
901 goto err; |
|
902 } |
|
903 |
|
904 ret = -EIO; |
|
905 /* update L2 table */ |
|
906 if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index)) |
|
907 goto err; |
|
908 |
|
909 for (i = 0; i < m->nb_clusters; i++) { |
|
910 if(l2_table[l2_index + i] != 0) |
|
911 old_cluster[j++] = l2_table[l2_index + i]; |
|
912 |
|
913 l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
|
914 (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
|
915 } |
|
916 |
|
917 if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t), |
|
918 l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) != |
|
919 m->nb_clusters * sizeof(uint64_t)) |
|
920 goto err; |
|
921 |
|
922 for (i = 0; i < j; i++) |
|
923 free_any_clusters(bs, old_cluster[i], 1); |
|
924 |
|
925 ret = 0; |
|
926 err: |
|
927 qemu_free(old_cluster); |
|
928 return ret; |
|
929 } |
|
930 |
|
931 /* |
|
932 * alloc_cluster_offset |
|
933 * |
|
934 * For a given offset of the disk image, return cluster offset in |
|
935 * qcow2 file. |
|
936 * |
|
937 * If the offset is not found, allocate a new cluster. |
|
938 * |
|
939 * Return the cluster offset if successful, |
|
940 * Return 0, otherwise. |
|
941 * |
|
942 */ |
|
943 |
|
944 static uint64_t alloc_cluster_offset(BlockDriverState *bs, |
|
945 uint64_t offset, |
|
946 int n_start, int n_end, |
|
947 int *num, QCowL2Meta *m) |
|
948 { |
|
949 BDRVQcowState *s = bs->opaque; |
|
950 int l2_index, ret; |
|
951 uint64_t l2_offset, *l2_table, cluster_offset; |
|
952 int nb_clusters, i = 0; |
|
953 |
|
954 ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
|
955 if (ret == 0) |
|
956 return 0; |
|
957 |
|
958 nb_clusters = size_to_clusters(s, n_end << 9); |
|
959 |
|
960 nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
|
961 |
|
962 cluster_offset = be64_to_cpu(l2_table[l2_index]); |
|
963 |
|
964 /* We keep all QCOW_OFLAG_COPIED clusters */ |
|
965 |
|
966 if (cluster_offset & QCOW_OFLAG_COPIED) { |
|
967 nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
|
968 &l2_table[l2_index], 0); |
|
969 |
|
970 cluster_offset &= ~QCOW_OFLAG_COPIED; |
|
971 m->nb_clusters = 0; |
|
972 |
|
973 goto out; |
|
974 } |
|
975 |
|
976 /* for the moment, multiple compressed clusters are not managed */ |
|
977 |
|
978 if (cluster_offset & QCOW_OFLAG_COMPRESSED) |
|
979 nb_clusters = 1; |
|
980 |
|
981 /* how many available clusters ? */ |
|
982 |
|
983 while (i < nb_clusters) { |
|
984 i += count_contiguous_free_clusters(nb_clusters - i, |
|
985 &l2_table[l2_index + i]); |
|
986 |
|
987 cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
|
988 |
|
989 if ((cluster_offset & QCOW_OFLAG_COPIED) || |
|
990 (cluster_offset & QCOW_OFLAG_COMPRESSED)) |
|
991 break; |
|
992 |
|
993 i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
|
994 &l2_table[l2_index + i], 0); |
|
995 |
|
996 if(be64_to_cpu(l2_table[l2_index + i])) |
|
997 break; |
|
998 } |
|
999 nb_clusters = i; |
|
1000 |
|
1001 /* allocate a new cluster */ |
|
1002 |
|
1003 cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size); |
|
1004 |
|
1005 /* save info needed for meta data update */ |
|
1006 m->offset = offset; |
|
1007 m->n_start = n_start; |
|
1008 m->nb_clusters = nb_clusters; |
|
1009 |
|
1010 out: |
|
1011 m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end); |
|
1012 |
|
1013 *num = m->nb_available - n_start; |
|
1014 |
|
1015 return cluster_offset; |
|
1016 } |
|
1017 |
|
1018 static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
|
1019 int nb_sectors, int *pnum) |
|
1020 { |
|
1021 uint64_t cluster_offset; |
|
1022 |
|
1023 *pnum = nb_sectors; |
|
1024 cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum); |
|
1025 |
|
1026 return (cluster_offset != 0); |
|
1027 } |
|
1028 |
|
1029 static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
|
1030 const uint8_t *buf, int buf_size) |
|
1031 { |
|
1032 z_stream strm1, *strm = &strm1; |
|
1033 int ret, out_len; |
|
1034 |
|
1035 memset(strm, 0, sizeof(*strm)); |
|
1036 |
|
1037 strm->next_in = (uint8_t *)buf; |
|
1038 strm->avail_in = buf_size; |
|
1039 strm->next_out = out_buf; |
|
1040 strm->avail_out = out_buf_size; |
|
1041 |
|
1042 ret = inflateInit2(strm, -12); |
|
1043 if (ret != Z_OK) |
|
1044 return -1; |
|
1045 ret = inflate(strm, Z_FINISH); |
|
1046 out_len = strm->next_out - out_buf; |
|
1047 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || |
|
1048 out_len != out_buf_size) { |
|
1049 inflateEnd(strm); |
|
1050 return -1; |
|
1051 } |
|
1052 inflateEnd(strm); |
|
1053 return 0; |
|
1054 } |
|
1055 |
|
1056 static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
|
1057 { |
|
1058 int ret, csize, nb_csectors, sector_offset; |
|
1059 uint64_t coffset; |
|
1060 |
|
1061 coffset = cluster_offset & s->cluster_offset_mask; |
|
1062 if (s->cluster_cache_offset != coffset) { |
|
1063 nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1; |
|
1064 sector_offset = coffset & 511; |
|
1065 csize = nb_csectors * 512 - sector_offset; |
|
1066 ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors); |
|
1067 if (ret < 0) { |
|
1068 return -1; |
|
1069 } |
|
1070 if (decompress_buffer(s->cluster_cache, s->cluster_size, |
|
1071 s->cluster_data + sector_offset, csize) < 0) { |
|
1072 return -1; |
|
1073 } |
|
1074 s->cluster_cache_offset = coffset; |
|
1075 } |
|
1076 return 0; |
|
1077 } |
|
1078 |
|
1079 /* handle reading after the end of the backing file */ |
|
1080 static int backing_read1(BlockDriverState *bs, |
|
1081 int64_t sector_num, uint8_t *buf, int nb_sectors) |
|
1082 { |
|
1083 int n1; |
|
1084 if ((sector_num + nb_sectors) <= bs->total_sectors) |
|
1085 return nb_sectors; |
|
1086 if (sector_num >= bs->total_sectors) |
|
1087 n1 = 0; |
|
1088 else |
|
1089 n1 = bs->total_sectors - sector_num; |
|
1090 memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); |
|
1091 return n1; |
|
1092 } |
|
1093 |
|
1094 static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
|
1095 uint8_t *buf, int nb_sectors) |
|
1096 { |
|
1097 BDRVQcowState *s = bs->opaque; |
|
1098 int ret, index_in_cluster, n, n1; |
|
1099 uint64_t cluster_offset; |
|
1100 |
|
1101 while (nb_sectors > 0) { |
|
1102 n = nb_sectors; |
|
1103 cluster_offset = get_cluster_offset(bs, sector_num << 9, &n); |
|
1104 index_in_cluster = sector_num & (s->cluster_sectors - 1); |
|
1105 if (!cluster_offset) { |
|
1106 if (bs->backing_hd) { |
|
1107 /* read from the base image */ |
|
1108 n1 = backing_read1(bs->backing_hd, sector_num, buf, n); |
|
1109 if (n1 > 0) { |
|
1110 ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
|
1111 if (ret < 0) |
|
1112 return -1; |
|
1113 } |
|
1114 } else { |
|
1115 memset(buf, 0, 512 * n); |
|
1116 } |
|
1117 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
|
1118 if (decompress_cluster(s, cluster_offset) < 0) |
|
1119 return -1; |
|
1120 memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
|
1121 } else { |
|
1122 ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
|
1123 if (ret != n * 512) |
|
1124 return -1; |
|
1125 if (s->crypt_method) { |
|
1126 encrypt_sectors(s, sector_num, buf, buf, n, 0, |
|
1127 &s->aes_decrypt_key); |
|
1128 } |
|
1129 } |
|
1130 nb_sectors -= n; |
|
1131 sector_num += n; |
|
1132 buf += n * 512; |
|
1133 } |
|
1134 return 0; |
|
1135 } |
|
1136 |
|
1137 static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
|
1138 const uint8_t *buf, int nb_sectors) |
|
1139 { |
|
1140 BDRVQcowState *s = bs->opaque; |
|
1141 int ret, index_in_cluster, n; |
|
1142 uint64_t cluster_offset; |
|
1143 int n_end; |
|
1144 QCowL2Meta l2meta; |
|
1145 |
|
1146 while (nb_sectors > 0) { |
|
1147 index_in_cluster = sector_num & (s->cluster_sectors - 1); |
|
1148 n_end = index_in_cluster + nb_sectors; |
|
1149 if (s->crypt_method && |
|
1150 n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
|
1151 n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
|
1152 cluster_offset = alloc_cluster_offset(bs, sector_num << 9, |
|
1153 index_in_cluster, |
|
1154 n_end, &n, &l2meta); |
|
1155 if (!cluster_offset) |
|
1156 return -1; |
|
1157 if (s->crypt_method) { |
|
1158 encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1, |
|
1159 &s->aes_encrypt_key); |
|
1160 ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, |
|
1161 s->cluster_data, n * 512); |
|
1162 } else { |
|
1163 ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
|
1164 } |
|
1165 if (ret != n * 512 || alloc_cluster_link_l2(bs, cluster_offset, &l2meta) < 0) { |
|
1166 free_any_clusters(bs, cluster_offset, l2meta.nb_clusters); |
|
1167 return -1; |
|
1168 } |
|
1169 nb_sectors -= n; |
|
1170 sector_num += n; |
|
1171 buf += n * 512; |
|
1172 } |
|
1173 s->cluster_cache_offset = -1; /* disable compressed cache */ |
|
1174 return 0; |
|
1175 } |
|
1176 |
|
1177 typedef struct QCowAIOCB { |
|
1178 BlockDriverAIOCB common; |
|
1179 int64_t sector_num; |
|
1180 uint8_t *buf; |
|
1181 int nb_sectors; |
|
1182 int n; |
|
1183 uint64_t cluster_offset; |
|
1184 uint8_t *cluster_data; |
|
1185 BlockDriverAIOCB *hd_aiocb; |
|
1186 QEMUBH *bh; |
|
1187 QCowL2Meta l2meta; |
|
1188 } QCowAIOCB; |
|
1189 |
|
1190 static void qcow_aio_read_cb(void *opaque, int ret); |
|
1191 static void qcow_aio_read_bh(void *opaque) |
|
1192 { |
|
1193 QCowAIOCB *acb = opaque; |
|
1194 qemu_bh_delete(acb->bh); |
|
1195 acb->bh = NULL; |
|
1196 qcow_aio_read_cb(opaque, 0); |
|
1197 } |
|
1198 |
|
1199 static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) |
|
1200 { |
|
1201 if (acb->bh) |
|
1202 return -EIO; |
|
1203 |
|
1204 acb->bh = qemu_bh_new(cb, acb); |
|
1205 if (!acb->bh) |
|
1206 return -EIO; |
|
1207 |
|
1208 qemu_bh_schedule(acb->bh); |
|
1209 |
|
1210 return 0; |
|
1211 } |
|
1212 |
|
1213 static void qcow_aio_read_cb(void *opaque, int ret) |
|
1214 { |
|
1215 QCowAIOCB *acb = opaque; |
|
1216 BlockDriverState *bs = acb->common.bs; |
|
1217 BDRVQcowState *s = bs->opaque; |
|
1218 int index_in_cluster, n1; |
|
1219 |
|
1220 acb->hd_aiocb = NULL; |
|
1221 if (ret < 0) { |
|
1222 fail: |
|
1223 acb->common.cb(acb->common.opaque, ret); |
|
1224 qemu_aio_release(acb); |
|
1225 return; |
|
1226 } |
|
1227 |
|
1228 /* post process the read buffer */ |
|
1229 if (!acb->cluster_offset) { |
|
1230 /* nothing to do */ |
|
1231 } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
|
1232 /* nothing to do */ |
|
1233 } else { |
|
1234 if (s->crypt_method) { |
|
1235 encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
|
1236 acb->n, 0, |
|
1237 &s->aes_decrypt_key); |
|
1238 } |
|
1239 } |
|
1240 |
|
1241 acb->nb_sectors -= acb->n; |
|
1242 acb->sector_num += acb->n; |
|
1243 acb->buf += acb->n * 512; |
|
1244 |
|
1245 if (acb->nb_sectors == 0) { |
|
1246 /* request completed */ |
|
1247 acb->common.cb(acb->common.opaque, 0); |
|
1248 qemu_aio_release(acb); |
|
1249 return; |
|
1250 } |
|
1251 |
|
1252 /* prepare next AIO request */ |
|
1253 acb->n = acb->nb_sectors; |
|
1254 acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n); |
|
1255 index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); |
|
1256 |
|
1257 if (!acb->cluster_offset) { |
|
1258 if (bs->backing_hd) { |
|
1259 /* read from the base image */ |
|
1260 n1 = backing_read1(bs->backing_hd, acb->sector_num, |
|
1261 acb->buf, acb->n); |
|
1262 if (n1 > 0) { |
|
1263 acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, acb->sector_num, |
|
1264 acb->buf, acb->n, qcow_aio_read_cb, acb); |
|
1265 if (acb->hd_aiocb == NULL) |
|
1266 goto fail; |
|
1267 } else { |
|
1268 ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
|
1269 if (ret < 0) |
|
1270 goto fail; |
|
1271 } |
|
1272 } else { |
|
1273 /* Note: in this case, no need to wait */ |
|
1274 memset(acb->buf, 0, 512 * acb->n); |
|
1275 ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
|
1276 if (ret < 0) |
|
1277 goto fail; |
|
1278 } |
|
1279 } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
|
1280 /* add AIO support for compressed blocks ? */ |
|
1281 if (decompress_cluster(s, acb->cluster_offset) < 0) |
|
1282 goto fail; |
|
1283 memcpy(acb->buf, |
|
1284 s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
|
1285 ret = qcow_schedule_bh(qcow_aio_read_bh, acb); |
|
1286 if (ret < 0) |
|
1287 goto fail; |
|
1288 } else { |
|
1289 if ((acb->cluster_offset & 511) != 0) { |
|
1290 ret = -EIO; |
|
1291 goto fail; |
|
1292 } |
|
1293 acb->hd_aiocb = bdrv_aio_read(s->hd, |
|
1294 (acb->cluster_offset >> 9) + index_in_cluster, |
|
1295 acb->buf, acb->n, qcow_aio_read_cb, acb); |
|
1296 if (acb->hd_aiocb == NULL) |
|
1297 goto fail; |
|
1298 } |
|
1299 } |
|
1300 |
|
1301 static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, |
|
1302 int64_t sector_num, uint8_t *buf, int nb_sectors, |
|
1303 BlockDriverCompletionFunc *cb, void *opaque) |
|
1304 { |
|
1305 QCowAIOCB *acb; |
|
1306 |
|
1307 acb = qemu_aio_get(bs, cb, opaque); |
|
1308 if (!acb) |
|
1309 return NULL; |
|
1310 acb->hd_aiocb = NULL; |
|
1311 acb->sector_num = sector_num; |
|
1312 acb->buf = buf; |
|
1313 acb->nb_sectors = nb_sectors; |
|
1314 acb->n = 0; |
|
1315 acb->cluster_offset = 0; |
|
1316 acb->l2meta.nb_clusters = 0; |
|
1317 return acb; |
|
1318 } |
|
1319 |
|
1320 static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs, |
|
1321 int64_t sector_num, uint8_t *buf, int nb_sectors, |
|
1322 BlockDriverCompletionFunc *cb, void *opaque) |
|
1323 { |
|
1324 QCowAIOCB *acb; |
|
1325 |
|
1326 acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque); |
|
1327 if (!acb) |
|
1328 return NULL; |
|
1329 |
|
1330 qcow_aio_read_cb(acb, 0); |
|
1331 return &acb->common; |
|
1332 } |
|
1333 |
|
1334 static void qcow_aio_write_cb(void *opaque, int ret) |
|
1335 { |
|
1336 QCowAIOCB *acb = opaque; |
|
1337 BlockDriverState *bs = acb->common.bs; |
|
1338 BDRVQcowState *s = bs->opaque; |
|
1339 int index_in_cluster; |
|
1340 const uint8_t *src_buf; |
|
1341 int n_end; |
|
1342 |
|
1343 acb->hd_aiocb = NULL; |
|
1344 |
|
1345 if (ret < 0) { |
|
1346 fail: |
|
1347 acb->common.cb(acb->common.opaque, ret); |
|
1348 qemu_aio_release(acb); |
|
1349 return; |
|
1350 } |
|
1351 |
|
1352 if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) { |
|
1353 free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters); |
|
1354 goto fail; |
|
1355 } |
|
1356 |
|
1357 acb->nb_sectors -= acb->n; |
|
1358 acb->sector_num += acb->n; |
|
1359 acb->buf += acb->n * 512; |
|
1360 |
|
1361 if (acb->nb_sectors == 0) { |
|
1362 /* request completed */ |
|
1363 acb->common.cb(acb->common.opaque, 0); |
|
1364 qemu_aio_release(acb); |
|
1365 return; |
|
1366 } |
|
1367 |
|
1368 index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); |
|
1369 n_end = index_in_cluster + acb->nb_sectors; |
|
1370 if (s->crypt_method && |
|
1371 n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) |
|
1372 n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; |
|
1373 |
|
1374 acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9, |
|
1375 index_in_cluster, |
|
1376 n_end, &acb->n, &acb->l2meta); |
|
1377 if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { |
|
1378 ret = -EIO; |
|
1379 goto fail; |
|
1380 } |
|
1381 if (s->crypt_method) { |
|
1382 if (!acb->cluster_data) { |
|
1383 acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * |
|
1384 s->cluster_size); |
|
1385 if (!acb->cluster_data) { |
|
1386 ret = -ENOMEM; |
|
1387 goto fail; |
|
1388 } |
|
1389 } |
|
1390 encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
|
1391 acb->n, 1, &s->aes_encrypt_key); |
|
1392 src_buf = acb->cluster_data; |
|
1393 } else { |
|
1394 src_buf = acb->buf; |
|
1395 } |
|
1396 acb->hd_aiocb = bdrv_aio_write(s->hd, |
|
1397 (acb->cluster_offset >> 9) + index_in_cluster, |
|
1398 src_buf, acb->n, |
|
1399 qcow_aio_write_cb, acb); |
|
1400 if (acb->hd_aiocb == NULL) |
|
1401 goto fail; |
|
1402 } |
|
1403 |
|
1404 static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs, |
|
1405 int64_t sector_num, const uint8_t *buf, int nb_sectors, |
|
1406 BlockDriverCompletionFunc *cb, void *opaque) |
|
1407 { |
|
1408 BDRVQcowState *s = bs->opaque; |
|
1409 QCowAIOCB *acb; |
|
1410 |
|
1411 s->cluster_cache_offset = -1; /* disable compressed cache */ |
|
1412 |
|
1413 acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque); |
|
1414 if (!acb) |
|
1415 return NULL; |
|
1416 |
|
1417 qcow_aio_write_cb(acb, 0); |
|
1418 return &acb->common; |
|
1419 } |
|
1420 |
|
1421 static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
|
1422 { |
|
1423 QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
|
1424 if (acb->hd_aiocb) |
|
1425 bdrv_aio_cancel(acb->hd_aiocb); |
|
1426 qemu_aio_release(acb); |
|
1427 } |
|
1428 |
|
1429 static void qcow_close(BlockDriverState *bs) |
|
1430 { |
|
1431 BDRVQcowState *s = bs->opaque; |
|
1432 qemu_free(s->l1_table); |
|
1433 qemu_free(s->l2_cache); |
|
1434 qemu_free(s->cluster_cache); |
|
1435 qemu_free(s->cluster_data); |
|
1436 refcount_close(bs); |
|
1437 bdrv_delete(s->hd); |
|
1438 } |
|
1439 |
|
1440 /* XXX: use std qcow open function ? */ |
|
1441 typedef struct QCowCreateState { |
|
1442 int cluster_size; |
|
1443 int cluster_bits; |
|
1444 uint16_t *refcount_block; |
|
1445 uint64_t *refcount_table; |
|
1446 int64_t l1_table_offset; |
|
1447 int64_t refcount_table_offset; |
|
1448 int64_t refcount_block_offset; |
|
1449 } QCowCreateState; |
|
1450 |
|
1451 static void create_refcount_update(QCowCreateState *s, |
|
1452 int64_t offset, int64_t size) |
|
1453 { |
|
1454 int refcount; |
|
1455 int64_t start, last, cluster_offset; |
|
1456 uint16_t *p; |
|
1457 |
|
1458 start = offset & ~(s->cluster_size - 1); |
|
1459 last = (offset + size - 1) & ~(s->cluster_size - 1); |
|
1460 for(cluster_offset = start; cluster_offset <= last; |
|
1461 cluster_offset += s->cluster_size) { |
|
1462 p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
|
1463 refcount = be16_to_cpu(*p); |
|
1464 refcount++; |
|
1465 *p = cpu_to_be16(refcount); |
|
1466 } |
|
1467 } |
|
1468 |
|
1469 static int qcow_create(const char *filename, int64_t total_size, |
|
1470 const char *backing_file, int flags) |
|
1471 { |
|
1472 int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; |
|
1473 QCowHeader header; |
|
1474 uint64_t tmp, offset; |
|
1475 QCowCreateState s1, *s = &s1; |
|
1476 |
|
1477 memset(s, 0, sizeof(*s)); |
|
1478 |
|
1479 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); |
|
1480 if (fd < 0) |
|
1481 return -1; |
|
1482 memset(&header, 0, sizeof(header)); |
|
1483 header.magic = cpu_to_be32(QCOW_MAGIC); |
|
1484 header.version = cpu_to_be32(QCOW_VERSION); |
|
1485 header.size = cpu_to_be64(total_size * 512); |
|
1486 header_size = sizeof(header); |
|
1487 backing_filename_len = 0; |
|
1488 if (backing_file) { |
|
1489 header.backing_file_offset = cpu_to_be64(header_size); |
|
1490 backing_filename_len = strlen(backing_file); |
|
1491 header.backing_file_size = cpu_to_be32(backing_filename_len); |
|
1492 header_size += backing_filename_len; |
|
1493 } |
|
1494 s->cluster_bits = 12; /* 4 KB clusters */ |
|
1495 s->cluster_size = 1 << s->cluster_bits; |
|
1496 header.cluster_bits = cpu_to_be32(s->cluster_bits); |
|
1497 header_size = (header_size + 7) & ~7; |
|
1498 if (flags & BLOCK_FLAG_ENCRYPT) { |
|
1499 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
|
1500 } else { |
|
1501 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
|
1502 } |
|
1503 l2_bits = s->cluster_bits - 3; |
|
1504 shift = s->cluster_bits + l2_bits; |
|
1505 l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); |
|
1506 offset = align_offset(header_size, s->cluster_size); |
|
1507 s->l1_table_offset = offset; |
|
1508 header.l1_table_offset = cpu_to_be64(s->l1_table_offset); |
|
1509 header.l1_size = cpu_to_be32(l1_size); |
|
1510 offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); |
|
1511 |
|
1512 s->refcount_table = qemu_mallocz(s->cluster_size); |
|
1513 if (!s->refcount_table) |
|
1514 goto fail; |
|
1515 s->refcount_block = qemu_mallocz(s->cluster_size); |
|
1516 if (!s->refcount_block) |
|
1517 goto fail; |
|
1518 |
|
1519 s->refcount_table_offset = offset; |
|
1520 header.refcount_table_offset = cpu_to_be64(offset); |
|
1521 header.refcount_table_clusters = cpu_to_be32(1); |
|
1522 offset += s->cluster_size; |
|
1523 |
|
1524 s->refcount_table[0] = cpu_to_be64(offset); |
|
1525 s->refcount_block_offset = offset; |
|
1526 offset += s->cluster_size; |
|
1527 |
|
1528 /* update refcounts */ |
|
1529 create_refcount_update(s, 0, header_size); |
|
1530 create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t)); |
|
1531 create_refcount_update(s, s->refcount_table_offset, s->cluster_size); |
|
1532 create_refcount_update(s, s->refcount_block_offset, s->cluster_size); |
|
1533 |
|
1534 /* write all the data */ |
|
1535 write(fd, &header, sizeof(header)); |
|
1536 if (backing_file) { |
|
1537 write(fd, backing_file, backing_filename_len); |
|
1538 } |
|
1539 lseek(fd, s->l1_table_offset, SEEK_SET); |
|
1540 tmp = 0; |
|
1541 for(i = 0;i < l1_size; i++) { |
|
1542 write(fd, &tmp, sizeof(tmp)); |
|
1543 } |
|
1544 lseek(fd, s->refcount_table_offset, SEEK_SET); |
|
1545 write(fd, s->refcount_table, s->cluster_size); |
|
1546 |
|
1547 lseek(fd, s->refcount_block_offset, SEEK_SET); |
|
1548 write(fd, s->refcount_block, s->cluster_size); |
|
1549 |
|
1550 qemu_free(s->refcount_table); |
|
1551 qemu_free(s->refcount_block); |
|
1552 close(fd); |
|
1553 return 0; |
|
1554 fail: |
|
1555 qemu_free(s->refcount_table); |
|
1556 qemu_free(s->refcount_block); |
|
1557 close(fd); |
|
1558 return -ENOMEM; |
|
1559 } |
|
1560 |
|
1561 static int qcow_make_empty(BlockDriverState *bs) |
|
1562 { |
|
1563 #if 0 |
|
1564 /* XXX: not correct */ |
|
1565 BDRVQcowState *s = bs->opaque; |
|
1566 uint32_t l1_length = s->l1_size * sizeof(uint64_t); |
|
1567 int ret; |
|
1568 |
|
1569 memset(s->l1_table, 0, l1_length); |
|
1570 if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) |
|
1571 return -1; |
|
1572 ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); |
|
1573 if (ret < 0) |
|
1574 return ret; |
|
1575 |
|
1576 l2_cache_reset(bs); |
|
1577 #endif |
|
1578 return 0; |
|
1579 } |
|
1580 |
|
1581 /* XXX: put compressed sectors first, then all the cluster aligned |
|
1582 tables to avoid losing bytes in alignment */ |
|
1583 static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
|
1584 const uint8_t *buf, int nb_sectors) |
|
1585 { |
|
1586 BDRVQcowState *s = bs->opaque; |
|
1587 z_stream strm; |
|
1588 int ret, out_len; |
|
1589 uint8_t *out_buf; |
|
1590 uint64_t cluster_offset; |
|
1591 |
|
1592 if (nb_sectors == 0) { |
|
1593 /* align end of file to a sector boundary to ease reading with |
|
1594 sector based I/Os */ |
|
1595 cluster_offset = bdrv_getlength(s->hd); |
|
1596 cluster_offset = (cluster_offset + 511) & ~511; |
|
1597 bdrv_truncate(s->hd, cluster_offset); |
|
1598 return 0; |
|
1599 } |
|
1600 |
|
1601 if (nb_sectors != s->cluster_sectors) |
|
1602 return -EINVAL; |
|
1603 |
|
1604 out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
|
1605 if (!out_buf) |
|
1606 return -ENOMEM; |
|
1607 |
|
1608 /* best compression, small window, no zlib header */ |
|
1609 memset(&strm, 0, sizeof(strm)); |
|
1610 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
|
1611 Z_DEFLATED, -12, |
|
1612 9, Z_DEFAULT_STRATEGY); |
|
1613 if (ret != 0) { |
|
1614 qemu_free(out_buf); |
|
1615 return -1; |
|
1616 } |
|
1617 |
|
1618 strm.avail_in = s->cluster_size; |
|
1619 strm.next_in = (uint8_t *)buf; |
|
1620 strm.avail_out = s->cluster_size; |
|
1621 strm.next_out = out_buf; |
|
1622 |
|
1623 ret = deflate(&strm, Z_FINISH); |
|
1624 if (ret != Z_STREAM_END && ret != Z_OK) { |
|
1625 qemu_free(out_buf); |
|
1626 deflateEnd(&strm); |
|
1627 return -1; |
|
1628 } |
|
1629 out_len = strm.next_out - out_buf; |
|
1630 |
|
1631 deflateEnd(&strm); |
|
1632 |
|
1633 if (ret != Z_STREAM_END || out_len >= s->cluster_size) { |
|
1634 /* could not compress: write normal cluster */ |
|
1635 qcow_write(bs, sector_num, buf, s->cluster_sectors); |
|
1636 } else { |
|
1637 cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9, |
|
1638 out_len); |
|
1639 if (!cluster_offset) |
|
1640 return -1; |
|
1641 cluster_offset &= s->cluster_offset_mask; |
|
1642 if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) { |
|
1643 qemu_free(out_buf); |
|
1644 return -1; |
|
1645 } |
|
1646 } |
|
1647 |
|
1648 qemu_free(out_buf); |
|
1649 return 0; |
|
1650 } |
|
1651 |
|
1652 static void qcow_flush(BlockDriverState *bs) |
|
1653 { |
|
1654 BDRVQcowState *s = bs->opaque; |
|
1655 bdrv_flush(s->hd); |
|
1656 } |
|
1657 |
|
1658 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
|
1659 { |
|
1660 BDRVQcowState *s = bs->opaque; |
|
1661 bdi->cluster_size = s->cluster_size; |
|
1662 bdi->vm_state_offset = (int64_t)s->l1_vm_state_index << |
|
1663 (s->cluster_bits + s->l2_bits); |
|
1664 return 0; |
|
1665 } |
|
1666 |
|
1667 /*********************************************************/ |
|
1668 /* snapshot support */ |
|
1669 |
|
1670 /* update the refcounts of snapshots and the copied flag */ |
|
1671 static int update_snapshot_refcount(BlockDriverState *bs, |
|
1672 int64_t l1_table_offset, |
|
1673 int l1_size, |
|
1674 int addend) |
|
1675 { |
|
1676 BDRVQcowState *s = bs->opaque; |
|
1677 uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
|
1678 int64_t old_offset, old_l2_offset; |
|
1679 int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount; |
|
1680 |
|
1681 l2_cache_reset(bs); |
|
1682 |
|
1683 l2_table = NULL; |
|
1684 l1_table = NULL; |
|
1685 l1_size2 = l1_size * sizeof(uint64_t); |
|
1686 l1_allocated = 0; |
|
1687 if (l1_table_offset != s->l1_table_offset) { |
|
1688 l1_table = qemu_malloc(l1_size2); |
|
1689 if (!l1_table) |
|
1690 goto fail; |
|
1691 l1_allocated = 1; |
|
1692 if (bdrv_pread(s->hd, l1_table_offset, |
|
1693 l1_table, l1_size2) != l1_size2) |
|
1694 goto fail; |
|
1695 for(i = 0;i < l1_size; i++) |
|
1696 be64_to_cpus(&l1_table[i]); |
|
1697 } else { |
|
1698 assert(l1_size == s->l1_size); |
|
1699 l1_table = s->l1_table; |
|
1700 l1_allocated = 0; |
|
1701 } |
|
1702 |
|
1703 l2_size = s->l2_size * sizeof(uint64_t); |
|
1704 l2_table = qemu_malloc(l2_size); |
|
1705 if (!l2_table) |
|
1706 goto fail; |
|
1707 l1_modified = 0; |
|
1708 for(i = 0; i < l1_size; i++) { |
|
1709 l2_offset = l1_table[i]; |
|
1710 if (l2_offset) { |
|
1711 old_l2_offset = l2_offset; |
|
1712 l2_offset &= ~QCOW_OFLAG_COPIED; |
|
1713 l2_modified = 0; |
|
1714 if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) |
|
1715 goto fail; |
|
1716 for(j = 0; j < s->l2_size; j++) { |
|
1717 offset = be64_to_cpu(l2_table[j]); |
|
1718 if (offset != 0) { |
|
1719 old_offset = offset; |
|
1720 offset &= ~QCOW_OFLAG_COPIED; |
|
1721 if (offset & QCOW_OFLAG_COMPRESSED) { |
|
1722 nb_csectors = ((offset >> s->csize_shift) & |
|
1723 s->csize_mask) + 1; |
|
1724 if (addend != 0) |
|
1725 update_refcount(bs, (offset & s->cluster_offset_mask) & ~511, |
|
1726 nb_csectors * 512, addend); |
|
1727 /* compressed clusters are never modified */ |
|
1728 refcount = 2; |
|
1729 } else { |
|
1730 if (addend != 0) { |
|
1731 refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
|
1732 } else { |
|
1733 refcount = get_refcount(bs, offset >> s->cluster_bits); |
|
1734 } |
|
1735 } |
|
1736 |
|
1737 if (refcount == 1) { |
|
1738 offset |= QCOW_OFLAG_COPIED; |
|
1739 } |
|
1740 if (offset != old_offset) { |
|
1741 l2_table[j] = cpu_to_be64(offset); |
|
1742 l2_modified = 1; |
|
1743 } |
|
1744 } |
|
1745 } |
|
1746 if (l2_modified) { |
|
1747 if (bdrv_pwrite(s->hd, |
|
1748 l2_offset, l2_table, l2_size) != l2_size) |
|
1749 goto fail; |
|
1750 } |
|
1751 |
|
1752 if (addend != 0) { |
|
1753 refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
|
1754 } else { |
|
1755 refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
|
1756 } |
|
1757 if (refcount == 1) { |
|
1758 l2_offset |= QCOW_OFLAG_COPIED; |
|
1759 } |
|
1760 if (l2_offset != old_l2_offset) { |
|
1761 l1_table[i] = l2_offset; |
|
1762 l1_modified = 1; |
|
1763 } |
|
1764 } |
|
1765 } |
|
1766 if (l1_modified) { |
|
1767 for(i = 0; i < l1_size; i++) |
|
1768 cpu_to_be64s(&l1_table[i]); |
|
1769 if (bdrv_pwrite(s->hd, l1_table_offset, l1_table, |
|
1770 l1_size2) != l1_size2) |
|
1771 goto fail; |
|
1772 for(i = 0; i < l1_size; i++) |
|
1773 be64_to_cpus(&l1_table[i]); |
|
1774 } |
|
1775 if (l1_allocated) |
|
1776 qemu_free(l1_table); |
|
1777 qemu_free(l2_table); |
|
1778 return 0; |
|
1779 fail: |
|
1780 if (l1_allocated) |
|
1781 qemu_free(l1_table); |
|
1782 qemu_free(l2_table); |
|
1783 return -EIO; |
|
1784 } |
|
1785 |
|
1786 static void qcow_free_snapshots(BlockDriverState *bs) |
|
1787 { |
|
1788 BDRVQcowState *s = bs->opaque; |
|
1789 int i; |
|
1790 |
|
1791 for(i = 0; i < s->nb_snapshots; i++) { |
|
1792 qemu_free(s->snapshots[i].name); |
|
1793 qemu_free(s->snapshots[i].id_str); |
|
1794 } |
|
1795 qemu_free(s->snapshots); |
|
1796 s->snapshots = NULL; |
|
1797 s->nb_snapshots = 0; |
|
1798 } |
|
1799 |
|
1800 static int qcow_read_snapshots(BlockDriverState *bs) |
|
1801 { |
|
1802 BDRVQcowState *s = bs->opaque; |
|
1803 QCowSnapshotHeader h; |
|
1804 QCowSnapshot *sn; |
|
1805 int i, id_str_size, name_size; |
|
1806 int64_t offset; |
|
1807 uint32_t extra_data_size; |
|
1808 |
|
1809 offset = s->snapshots_offset; |
|
1810 s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot)); |
|
1811 if (!s->snapshots) |
|
1812 goto fail; |
|
1813 for(i = 0; i < s->nb_snapshots; i++) { |
|
1814 offset = align_offset(offset, 8); |
|
1815 if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
|
1816 goto fail; |
|
1817 offset += sizeof(h); |
|
1818 sn = s->snapshots + i; |
|
1819 sn->l1_table_offset = be64_to_cpu(h.l1_table_offset); |
|
1820 sn->l1_size = be32_to_cpu(h.l1_size); |
|
1821 sn->vm_state_size = be32_to_cpu(h.vm_state_size); |
|
1822 sn->date_sec = be32_to_cpu(h.date_sec); |
|
1823 sn->date_nsec = be32_to_cpu(h.date_nsec); |
|
1824 sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec); |
|
1825 extra_data_size = be32_to_cpu(h.extra_data_size); |
|
1826 |
|
1827 id_str_size = be16_to_cpu(h.id_str_size); |
|
1828 name_size = be16_to_cpu(h.name_size); |
|
1829 |
|
1830 offset += extra_data_size; |
|
1831 |
|
1832 sn->id_str = qemu_malloc(id_str_size + 1); |
|
1833 if (!sn->id_str) |
|
1834 goto fail; |
|
1835 if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size) |
|
1836 goto fail; |
|
1837 offset += id_str_size; |
|
1838 sn->id_str[id_str_size] = '\0'; |
|
1839 |
|
1840 sn->name = qemu_malloc(name_size + 1); |
|
1841 if (!sn->name) |
|
1842 goto fail; |
|
1843 if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size) |
|
1844 goto fail; |
|
1845 offset += name_size; |
|
1846 sn->name[name_size] = '\0'; |
|
1847 } |
|
1848 s->snapshots_size = offset - s->snapshots_offset; |
|
1849 return 0; |
|
1850 fail: |
|
1851 qcow_free_snapshots(bs); |
|
1852 return -1; |
|
1853 } |
|
1854 |
|
1855 /* add at the end of the file a new list of snapshots */ |
|
1856 static int qcow_write_snapshots(BlockDriverState *bs) |
|
1857 { |
|
1858 BDRVQcowState *s = bs->opaque; |
|
1859 QCowSnapshot *sn; |
|
1860 QCowSnapshotHeader h; |
|
1861 int i, name_size, id_str_size, snapshots_size; |
|
1862 uint64_t data64; |
|
1863 uint32_t data32; |
|
1864 int64_t offset, snapshots_offset; |
|
1865 |
|
1866 /* compute the size of the snapshots */ |
|
1867 offset = 0; |
|
1868 for(i = 0; i < s->nb_snapshots; i++) { |
|
1869 sn = s->snapshots + i; |
|
1870 offset = align_offset(offset, 8); |
|
1871 offset += sizeof(h); |
|
1872 offset += strlen(sn->id_str); |
|
1873 offset += strlen(sn->name); |
|
1874 } |
|
1875 snapshots_size = offset; |
|
1876 |
|
1877 snapshots_offset = alloc_clusters(bs, snapshots_size); |
|
1878 offset = snapshots_offset; |
|
1879 |
|
1880 for(i = 0; i < s->nb_snapshots; i++) { |
|
1881 sn = s->snapshots + i; |
|
1882 memset(&h, 0, sizeof(h)); |
|
1883 h.l1_table_offset = cpu_to_be64(sn->l1_table_offset); |
|
1884 h.l1_size = cpu_to_be32(sn->l1_size); |
|
1885 h.vm_state_size = cpu_to_be32(sn->vm_state_size); |
|
1886 h.date_sec = cpu_to_be32(sn->date_sec); |
|
1887 h.date_nsec = cpu_to_be32(sn->date_nsec); |
|
1888 h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec); |
|
1889 |
|
1890 id_str_size = strlen(sn->id_str); |
|
1891 name_size = strlen(sn->name); |
|
1892 h.id_str_size = cpu_to_be16(id_str_size); |
|
1893 h.name_size = cpu_to_be16(name_size); |
|
1894 offset = align_offset(offset, 8); |
|
1895 if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h)) |
|
1896 goto fail; |
|
1897 offset += sizeof(h); |
|
1898 if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size) |
|
1899 goto fail; |
|
1900 offset += id_str_size; |
|
1901 if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size) |
|
1902 goto fail; |
|
1903 offset += name_size; |
|
1904 } |
|
1905 |
|
1906 /* update the various header fields */ |
|
1907 data64 = cpu_to_be64(snapshots_offset); |
|
1908 if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset), |
|
1909 &data64, sizeof(data64)) != sizeof(data64)) |
|
1910 goto fail; |
|
1911 data32 = cpu_to_be32(s->nb_snapshots); |
|
1912 if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots), |
|
1913 &data32, sizeof(data32)) != sizeof(data32)) |
|
1914 goto fail; |
|
1915 |
|
1916 /* free the old snapshot table */ |
|
1917 free_clusters(bs, s->snapshots_offset, s->snapshots_size); |
|
1918 s->snapshots_offset = snapshots_offset; |
|
1919 s->snapshots_size = snapshots_size; |
|
1920 return 0; |
|
1921 fail: |
|
1922 return -1; |
|
1923 } |
|
1924 |
|
1925 static void find_new_snapshot_id(BlockDriverState *bs, |
|
1926 char *id_str, int id_str_size) |
|
1927 { |
|
1928 BDRVQcowState *s = bs->opaque; |
|
1929 QCowSnapshot *sn; |
|
1930 int i, id, id_max = 0; |
|
1931 |
|
1932 for(i = 0; i < s->nb_snapshots; i++) { |
|
1933 sn = s->snapshots + i; |
|
1934 id = strtoul(sn->id_str, NULL, 10); |
|
1935 if (id > id_max) |
|
1936 id_max = id; |
|
1937 } |
|
1938 snprintf(id_str, id_str_size, "%d", id_max + 1); |
|
1939 } |
|
1940 |
|
1941 static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str) |
|
1942 { |
|
1943 BDRVQcowState *s = bs->opaque; |
|
1944 int i; |
|
1945 |
|
1946 for(i = 0; i < s->nb_snapshots; i++) { |
|
1947 if (!strcmp(s->snapshots[i].id_str, id_str)) |
|
1948 return i; |
|
1949 } |
|
1950 return -1; |
|
1951 } |
|
1952 |
|
1953 static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name) |
|
1954 { |
|
1955 BDRVQcowState *s = bs->opaque; |
|
1956 int i, ret; |
|
1957 |
|
1958 ret = find_snapshot_by_id(bs, name); |
|
1959 if (ret >= 0) |
|
1960 return ret; |
|
1961 for(i = 0; i < s->nb_snapshots; i++) { |
|
1962 if (!strcmp(s->snapshots[i].name, name)) |
|
1963 return i; |
|
1964 } |
|
1965 return -1; |
|
1966 } |
|
1967 |
|
1968 /* if no id is provided, a new one is constructed */ |
|
1969 static int qcow_snapshot_create(BlockDriverState *bs, |
|
1970 QEMUSnapshotInfo *sn_info) |
|
1971 { |
|
1972 BDRVQcowState *s = bs->opaque; |
|
1973 QCowSnapshot *snapshots1, sn1, *sn = &sn1; |
|
1974 int i, ret; |
|
1975 uint64_t *l1_table = NULL; |
|
1976 |
|
1977 memset(sn, 0, sizeof(*sn)); |
|
1978 |
|
1979 if (sn_info->id_str[0] == '\0') { |
|
1980 /* compute a new id */ |
|
1981 find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str)); |
|
1982 } |
|
1983 |
|
1984 /* check that the ID is unique */ |
|
1985 if (find_snapshot_by_id(bs, sn_info->id_str) >= 0) |
|
1986 return -ENOENT; |
|
1987 |
|
1988 sn->id_str = qemu_strdup(sn_info->id_str); |
|
1989 if (!sn->id_str) |
|
1990 goto fail; |
|
1991 sn->name = qemu_strdup(sn_info->name); |
|
1992 if (!sn->name) |
|
1993 goto fail; |
|
1994 sn->vm_state_size = sn_info->vm_state_size; |
|
1995 sn->date_sec = sn_info->date_sec; |
|
1996 sn->date_nsec = sn_info->date_nsec; |
|
1997 sn->vm_clock_nsec = sn_info->vm_clock_nsec; |
|
1998 |
|
1999 ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1); |
|
2000 if (ret < 0) |
|
2001 goto fail; |
|
2002 |
|
2003 /* create the L1 table of the snapshot */ |
|
2004 sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t)); |
|
2005 sn->l1_size = s->l1_size; |
|
2006 |
|
2007 l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t)); |
|
2008 if (!l1_table) |
|
2009 goto fail; |
|
2010 for(i = 0; i < s->l1_size; i++) { |
|
2011 l1_table[i] = cpu_to_be64(s->l1_table[i]); |
|
2012 } |
|
2013 if (bdrv_pwrite(s->hd, sn->l1_table_offset, |
|
2014 l1_table, s->l1_size * sizeof(uint64_t)) != |
|
2015 (s->l1_size * sizeof(uint64_t))) |
|
2016 goto fail; |
|
2017 qemu_free(l1_table); |
|
2018 l1_table = NULL; |
|
2019 |
|
2020 snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot)); |
|
2021 if (!snapshots1) |
|
2022 goto fail; |
|
2023 memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot)); |
|
2024 s->snapshots = snapshots1; |
|
2025 s->snapshots[s->nb_snapshots++] = *sn; |
|
2026 |
|
2027 if (qcow_write_snapshots(bs) < 0) |
|
2028 goto fail; |
|
2029 #ifdef DEBUG_ALLOC |
|
2030 check_refcounts(bs); |
|
2031 #endif |
|
2032 return 0; |
|
2033 fail: |
|
2034 qemu_free(sn->name); |
|
2035 qemu_free(l1_table); |
|
2036 return -1; |
|
2037 } |
|
2038 |
|
2039 /* copy the snapshot 'snapshot_name' into the current disk image */ |
|
2040 static int qcow_snapshot_goto(BlockDriverState *bs, |
|
2041 const char *snapshot_id) |
|
2042 { |
|
2043 BDRVQcowState *s = bs->opaque; |
|
2044 QCowSnapshot *sn; |
|
2045 int i, snapshot_index, l1_size2; |
|
2046 |
|
2047 snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
|
2048 if (snapshot_index < 0) |
|
2049 return -ENOENT; |
|
2050 sn = &s->snapshots[snapshot_index]; |
|
2051 |
|
2052 if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0) |
|
2053 goto fail; |
|
2054 |
|
2055 if (grow_l1_table(bs, sn->l1_size) < 0) |
|
2056 goto fail; |
|
2057 |
|
2058 s->l1_size = sn->l1_size; |
|
2059 l1_size2 = s->l1_size * sizeof(uint64_t); |
|
2060 /* copy the snapshot l1 table to the current l1 table */ |
|
2061 if (bdrv_pread(s->hd, sn->l1_table_offset, |
|
2062 s->l1_table, l1_size2) != l1_size2) |
|
2063 goto fail; |
|
2064 if (bdrv_pwrite(s->hd, s->l1_table_offset, |
|
2065 s->l1_table, l1_size2) != l1_size2) |
|
2066 goto fail; |
|
2067 for(i = 0;i < s->l1_size; i++) { |
|
2068 be64_to_cpus(&s->l1_table[i]); |
|
2069 } |
|
2070 |
|
2071 if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0) |
|
2072 goto fail; |
|
2073 |
|
2074 #ifdef DEBUG_ALLOC |
|
2075 check_refcounts(bs); |
|
2076 #endif |
|
2077 return 0; |
|
2078 fail: |
|
2079 return -EIO; |
|
2080 } |
|
2081 |
|
2082 static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
|
2083 { |
|
2084 BDRVQcowState *s = bs->opaque; |
|
2085 QCowSnapshot *sn; |
|
2086 int snapshot_index, ret; |
|
2087 |
|
2088 snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id); |
|
2089 if (snapshot_index < 0) |
|
2090 return -ENOENT; |
|
2091 sn = &s->snapshots[snapshot_index]; |
|
2092 |
|
2093 ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1); |
|
2094 if (ret < 0) |
|
2095 return ret; |
|
2096 /* must update the copied flag on the current cluster offsets */ |
|
2097 ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0); |
|
2098 if (ret < 0) |
|
2099 return ret; |
|
2100 free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t)); |
|
2101 |
|
2102 qemu_free(sn->id_str); |
|
2103 qemu_free(sn->name); |
|
2104 memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn)); |
|
2105 s->nb_snapshots--; |
|
2106 ret = qcow_write_snapshots(bs); |
|
2107 if (ret < 0) { |
|
2108 /* XXX: restore snapshot if error ? */ |
|
2109 return ret; |
|
2110 } |
|
2111 #ifdef DEBUG_ALLOC |
|
2112 check_refcounts(bs); |
|
2113 #endif |
|
2114 return 0; |
|
2115 } |
|
2116 |
|
2117 static int qcow_snapshot_list(BlockDriverState *bs, |
|
2118 QEMUSnapshotInfo **psn_tab) |
|
2119 { |
|
2120 BDRVQcowState *s = bs->opaque; |
|
2121 QEMUSnapshotInfo *sn_tab, *sn_info; |
|
2122 QCowSnapshot *sn; |
|
2123 int i; |
|
2124 |
|
2125 sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo)); |
|
2126 if (!sn_tab) |
|
2127 goto fail; |
|
2128 for(i = 0; i < s->nb_snapshots; i++) { |
|
2129 sn_info = sn_tab + i; |
|
2130 sn = s->snapshots + i; |
|
2131 pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), |
|
2132 sn->id_str); |
|
2133 pstrcpy(sn_info->name, sizeof(sn_info->name), |
|
2134 sn->name); |
|
2135 sn_info->vm_state_size = sn->vm_state_size; |
|
2136 sn_info->date_sec = sn->date_sec; |
|
2137 sn_info->date_nsec = sn->date_nsec; |
|
2138 sn_info->vm_clock_nsec = sn->vm_clock_nsec; |
|
2139 } |
|
2140 *psn_tab = sn_tab; |
|
2141 return s->nb_snapshots; |
|
2142 fail: |
|
2143 qemu_free(sn_tab); |
|
2144 *psn_tab = NULL; |
|
2145 return -ENOMEM; |
|
2146 } |
|
2147 |
|
2148 /*********************************************************/ |
|
2149 /* refcount handling */ |
|
2150 |
|
2151 static int refcount_init(BlockDriverState *bs) |
|
2152 { |
|
2153 BDRVQcowState *s = bs->opaque; |
|
2154 int ret, refcount_table_size2, i; |
|
2155 |
|
2156 s->refcount_block_cache = qemu_malloc(s->cluster_size); |
|
2157 if (!s->refcount_block_cache) |
|
2158 goto fail; |
|
2159 refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
|
2160 s->refcount_table = qemu_malloc(refcount_table_size2); |
|
2161 if (!s->refcount_table) |
|
2162 goto fail; |
|
2163 if (s->refcount_table_size > 0) { |
|
2164 ret = bdrv_pread(s->hd, s->refcount_table_offset, |
|
2165 s->refcount_table, refcount_table_size2); |
|
2166 if (ret != refcount_table_size2) |
|
2167 goto fail; |
|
2168 for(i = 0; i < s->refcount_table_size; i++) |
|
2169 be64_to_cpus(&s->refcount_table[i]); |
|
2170 } |
|
2171 return 0; |
|
2172 fail: |
|
2173 return -ENOMEM; |
|
2174 } |
|
2175 |
|
2176 static void refcount_close(BlockDriverState *bs) |
|
2177 { |
|
2178 BDRVQcowState *s = bs->opaque; |
|
2179 qemu_free(s->refcount_block_cache); |
|
2180 qemu_free(s->refcount_table); |
|
2181 } |
|
2182 |
|
2183 |
|
2184 static int load_refcount_block(BlockDriverState *bs, |
|
2185 int64_t refcount_block_offset) |
|
2186 { |
|
2187 BDRVQcowState *s = bs->opaque; |
|
2188 int ret; |
|
2189 ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
|
2190 s->cluster_size); |
|
2191 if (ret != s->cluster_size) |
|
2192 return -EIO; |
|
2193 s->refcount_block_cache_offset = refcount_block_offset; |
|
2194 return 0; |
|
2195 } |
|
2196 |
|
2197 static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
|
2198 { |
|
2199 BDRVQcowState *s = bs->opaque; |
|
2200 int refcount_table_index, block_index; |
|
2201 int64_t refcount_block_offset; |
|
2202 |
|
2203 refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
2204 if (refcount_table_index >= s->refcount_table_size) |
|
2205 return 0; |
|
2206 refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
2207 if (!refcount_block_offset) |
|
2208 return 0; |
|
2209 if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
2210 /* better than nothing: return allocated if read error */ |
|
2211 if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
2212 return 1; |
|
2213 } |
|
2214 block_index = cluster_index & |
|
2215 ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
2216 return be16_to_cpu(s->refcount_block_cache[block_index]); |
|
2217 } |
|
2218 |
|
2219 /* return < 0 if error */ |
|
2220 static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) |
|
2221 { |
|
2222 BDRVQcowState *s = bs->opaque; |
|
2223 int i, nb_clusters; |
|
2224 |
|
2225 nb_clusters = size_to_clusters(s, size); |
|
2226 retry: |
|
2227 for(i = 0; i < nb_clusters; i++) { |
|
2228 int64_t i = s->free_cluster_index++; |
|
2229 if (get_refcount(bs, i) != 0) |
|
2230 goto retry; |
|
2231 } |
|
2232 #ifdef DEBUG_ALLOC2 |
|
2233 printf("alloc_clusters: size=%lld -> %lld\n", |
|
2234 size, |
|
2235 (s->free_cluster_index - nb_clusters) << s->cluster_bits); |
|
2236 #endif |
|
2237 return (s->free_cluster_index - nb_clusters) << s->cluster_bits; |
|
2238 } |
|
2239 |
|
2240 static int64_t alloc_clusters(BlockDriverState *bs, int64_t size) |
|
2241 { |
|
2242 int64_t offset; |
|
2243 |
|
2244 offset = alloc_clusters_noref(bs, size); |
|
2245 update_refcount(bs, offset, size, 1); |
|
2246 return offset; |
|
2247 } |
|
2248 |
|
2249 /* only used to allocate compressed sectors. We try to allocate |
|
2250 contiguous sectors. size must be <= cluster_size */ |
|
2251 static int64_t alloc_bytes(BlockDriverState *bs, int size) |
|
2252 { |
|
2253 BDRVQcowState *s = bs->opaque; |
|
2254 int64_t offset, cluster_offset; |
|
2255 int free_in_cluster; |
|
2256 |
|
2257 assert(size > 0 && size <= s->cluster_size); |
|
2258 if (s->free_byte_offset == 0) { |
|
2259 s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
|
2260 } |
|
2261 redo: |
|
2262 free_in_cluster = s->cluster_size - |
|
2263 (s->free_byte_offset & (s->cluster_size - 1)); |
|
2264 if (size <= free_in_cluster) { |
|
2265 /* enough space in current cluster */ |
|
2266 offset = s->free_byte_offset; |
|
2267 s->free_byte_offset += size; |
|
2268 free_in_cluster -= size; |
|
2269 if (free_in_cluster == 0) |
|
2270 s->free_byte_offset = 0; |
|
2271 if ((offset & (s->cluster_size - 1)) != 0) |
|
2272 update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
2273 } else { |
|
2274 offset = alloc_clusters(bs, s->cluster_size); |
|
2275 cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); |
|
2276 if ((cluster_offset + s->cluster_size) == offset) { |
|
2277 /* we are lucky: contiguous data */ |
|
2278 offset = s->free_byte_offset; |
|
2279 update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
2280 s->free_byte_offset += size; |
|
2281 } else { |
|
2282 s->free_byte_offset = offset; |
|
2283 goto redo; |
|
2284 } |
|
2285 } |
|
2286 return offset; |
|
2287 } |
|
2288 |
|
2289 static void free_clusters(BlockDriverState *bs, |
|
2290 int64_t offset, int64_t size) |
|
2291 { |
|
2292 update_refcount(bs, offset, size, -1); |
|
2293 } |
|
2294 |
|
2295 static int grow_refcount_table(BlockDriverState *bs, int min_size) |
|
2296 { |
|
2297 BDRVQcowState *s = bs->opaque; |
|
2298 int new_table_size, new_table_size2, refcount_table_clusters, i, ret; |
|
2299 uint64_t *new_table; |
|
2300 int64_t table_offset; |
|
2301 uint8_t data[12]; |
|
2302 int old_table_size; |
|
2303 int64_t old_table_offset; |
|
2304 |
|
2305 if (min_size <= s->refcount_table_size) |
|
2306 return 0; |
|
2307 /* compute new table size */ |
|
2308 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); |
|
2309 for(;;) { |
|
2310 if (refcount_table_clusters == 0) { |
|
2311 refcount_table_clusters = 1; |
|
2312 } else { |
|
2313 refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
|
2314 } |
|
2315 new_table_size = refcount_table_clusters << (s->cluster_bits - 3); |
|
2316 if (min_size <= new_table_size) |
|
2317 break; |
|
2318 } |
|
2319 #ifdef DEBUG_ALLOC2 |
|
2320 printf("grow_refcount_table from %d to %d\n", |
|
2321 s->refcount_table_size, |
|
2322 new_table_size); |
|
2323 #endif |
|
2324 new_table_size2 = new_table_size * sizeof(uint64_t); |
|
2325 new_table = qemu_mallocz(new_table_size2); |
|
2326 if (!new_table) |
|
2327 return -ENOMEM; |
|
2328 memcpy(new_table, s->refcount_table, |
|
2329 s->refcount_table_size * sizeof(uint64_t)); |
|
2330 for(i = 0; i < s->refcount_table_size; i++) |
|
2331 cpu_to_be64s(&new_table[i]); |
|
2332 /* Note: we cannot update the refcount now to avoid recursion */ |
|
2333 table_offset = alloc_clusters_noref(bs, new_table_size2); |
|
2334 ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
|
2335 if (ret != new_table_size2) |
|
2336 goto fail; |
|
2337 for(i = 0; i < s->refcount_table_size; i++) |
|
2338 be64_to_cpus(&new_table[i]); |
|
2339 |
|
2340 cpu_to_be64w((uint64_t*)data, table_offset); |
|
2341 cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters); |
|
2342 if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset), |
|
2343 data, sizeof(data)) != sizeof(data)) |
|
2344 goto fail; |
|
2345 qemu_free(s->refcount_table); |
|
2346 old_table_offset = s->refcount_table_offset; |
|
2347 old_table_size = s->refcount_table_size; |
|
2348 s->refcount_table = new_table; |
|
2349 s->refcount_table_size = new_table_size; |
|
2350 s->refcount_table_offset = table_offset; |
|
2351 |
|
2352 update_refcount(bs, table_offset, new_table_size2, 1); |
|
2353 free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); |
|
2354 return 0; |
|
2355 fail: |
|
2356 free_clusters(bs, table_offset, new_table_size2); |
|
2357 qemu_free(new_table); |
|
2358 return -EIO; |
|
2359 } |
|
2360 |
|
2361 /* addend must be 1 or -1 */ |
|
2362 /* XXX: cache several refcount block clusters ? */ |
|
2363 static int update_cluster_refcount(BlockDriverState *bs, |
|
2364 int64_t cluster_index, |
|
2365 int addend) |
|
2366 { |
|
2367 BDRVQcowState *s = bs->opaque; |
|
2368 int64_t offset, refcount_block_offset; |
|
2369 int ret, refcount_table_index, block_index, refcount; |
|
2370 uint64_t data64; |
|
2371 |
|
2372 refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
2373 if (refcount_table_index >= s->refcount_table_size) { |
|
2374 if (addend < 0) |
|
2375 return -EINVAL; |
|
2376 ret = grow_refcount_table(bs, refcount_table_index + 1); |
|
2377 if (ret < 0) |
|
2378 return ret; |
|
2379 } |
|
2380 refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
2381 if (!refcount_block_offset) { |
|
2382 if (addend < 0) |
|
2383 return -EINVAL; |
|
2384 /* create a new refcount block */ |
|
2385 /* Note: we cannot update the refcount now to avoid recursion */ |
|
2386 offset = alloc_clusters_noref(bs, s->cluster_size); |
|
2387 memset(s->refcount_block_cache, 0, s->cluster_size); |
|
2388 ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
|
2389 if (ret != s->cluster_size) |
|
2390 return -EINVAL; |
|
2391 s->refcount_table[refcount_table_index] = offset; |
|
2392 data64 = cpu_to_be64(offset); |
|
2393 ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
|
2394 refcount_table_index * sizeof(uint64_t), |
|
2395 &data64, sizeof(data64)); |
|
2396 if (ret != sizeof(data64)) |
|
2397 return -EINVAL; |
|
2398 |
|
2399 refcount_block_offset = offset; |
|
2400 s->refcount_block_cache_offset = offset; |
|
2401 update_refcount(bs, offset, s->cluster_size, 1); |
|
2402 } else { |
|
2403 if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
2404 if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
2405 return -EIO; |
|
2406 } |
|
2407 } |
|
2408 /* we can update the count and save it */ |
|
2409 block_index = cluster_index & |
|
2410 ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
2411 refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
|
2412 refcount += addend; |
|
2413 if (refcount < 0 || refcount > 0xffff) |
|
2414 return -EINVAL; |
|
2415 if (refcount == 0 && cluster_index < s->free_cluster_index) { |
|
2416 s->free_cluster_index = cluster_index; |
|
2417 } |
|
2418 s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
|
2419 if (bdrv_pwrite(s->hd, |
|
2420 refcount_block_offset + (block_index << REFCOUNT_SHIFT), |
|
2421 &s->refcount_block_cache[block_index], 2) != 2) |
|
2422 return -EIO; |
|
2423 return refcount; |
|
2424 } |
|
2425 |
|
2426 static void update_refcount(BlockDriverState *bs, |
|
2427 int64_t offset, int64_t length, |
|
2428 int addend) |
|
2429 { |
|
2430 BDRVQcowState *s = bs->opaque; |
|
2431 int64_t start, last, cluster_offset; |
|
2432 |
|
2433 #ifdef DEBUG_ALLOC2 |
|
2434 printf("update_refcount: offset=%lld size=%lld addend=%d\n", |
|
2435 offset, length, addend); |
|
2436 #endif |
|
2437 if (length <= 0) |
|
2438 return; |
|
2439 start = offset & ~(s->cluster_size - 1); |
|
2440 last = (offset + length - 1) & ~(s->cluster_size - 1); |
|
2441 for(cluster_offset = start; cluster_offset <= last; |
|
2442 cluster_offset += s->cluster_size) { |
|
2443 update_cluster_refcount(bs, cluster_offset >> s->cluster_bits, addend); |
|
2444 } |
|
2445 } |
|
2446 |
|
2447 #ifdef DEBUG_ALLOC |
|
2448 static void inc_refcounts(BlockDriverState *bs, |
|
2449 uint16_t *refcount_table, |
|
2450 int refcount_table_size, |
|
2451 int64_t offset, int64_t size) |
|
2452 { |
|
2453 BDRVQcowState *s = bs->opaque; |
|
2454 int64_t start, last, cluster_offset; |
|
2455 int k; |
|
2456 |
|
2457 if (size <= 0) |
|
2458 return; |
|
2459 |
|
2460 start = offset & ~(s->cluster_size - 1); |
|
2461 last = (offset + size - 1) & ~(s->cluster_size - 1); |
|
2462 for(cluster_offset = start; cluster_offset <= last; |
|
2463 cluster_offset += s->cluster_size) { |
|
2464 k = cluster_offset >> s->cluster_bits; |
|
2465 if (k < 0 || k >= refcount_table_size) { |
|
2466 printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset); |
|
2467 } else { |
|
2468 if (++refcount_table[k] == 0) { |
|
2469 printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset); |
|
2470 } |
|
2471 } |
|
2472 } |
|
2473 } |
|
2474 |
|
2475 static int check_refcounts_l1(BlockDriverState *bs, |
|
2476 uint16_t *refcount_table, |
|
2477 int refcount_table_size, |
|
2478 int64_t l1_table_offset, int l1_size, |
|
2479 int check_copied) |
|
2480 { |
|
2481 BDRVQcowState *s = bs->opaque; |
|
2482 uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2; |
|
2483 int l2_size, i, j, nb_csectors, refcount; |
|
2484 |
|
2485 l2_table = NULL; |
|
2486 l1_size2 = l1_size * sizeof(uint64_t); |
|
2487 |
|
2488 inc_refcounts(bs, refcount_table, refcount_table_size, |
|
2489 l1_table_offset, l1_size2); |
|
2490 |
|
2491 l1_table = qemu_malloc(l1_size2); |
|
2492 if (!l1_table) |
|
2493 goto fail; |
|
2494 if (bdrv_pread(s->hd, l1_table_offset, |
|
2495 l1_table, l1_size2) != l1_size2) |
|
2496 goto fail; |
|
2497 for(i = 0;i < l1_size; i++) |
|
2498 be64_to_cpus(&l1_table[i]); |
|
2499 |
|
2500 l2_size = s->l2_size * sizeof(uint64_t); |
|
2501 l2_table = qemu_malloc(l2_size); |
|
2502 if (!l2_table) |
|
2503 goto fail; |
|
2504 for(i = 0; i < l1_size; i++) { |
|
2505 l2_offset = l1_table[i]; |
|
2506 if (l2_offset) { |
|
2507 if (check_copied) { |
|
2508 refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
|
2509 if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
|
2510 printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n", |
|
2511 l2_offset, refcount); |
|
2512 } |
|
2513 } |
|
2514 l2_offset &= ~QCOW_OFLAG_COPIED; |
|
2515 if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) |
|
2516 goto fail; |
|
2517 for(j = 0; j < s->l2_size; j++) { |
|
2518 offset = be64_to_cpu(l2_table[j]); |
|
2519 if (offset != 0) { |
|
2520 if (offset & QCOW_OFLAG_COMPRESSED) { |
|
2521 if (offset & QCOW_OFLAG_COPIED) { |
|
2522 printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n", |
|
2523 offset >> s->cluster_bits); |
|
2524 offset &= ~QCOW_OFLAG_COPIED; |
|
2525 } |
|
2526 nb_csectors = ((offset >> s->csize_shift) & |
|
2527 s->csize_mask) + 1; |
|
2528 offset &= s->cluster_offset_mask; |
|
2529 inc_refcounts(bs, refcount_table, |
|
2530 refcount_table_size, |
|
2531 offset & ~511, nb_csectors * 512); |
|
2532 } else { |
|
2533 if (check_copied) { |
|
2534 refcount = get_refcount(bs, (offset & ~QCOW_OFLAG_COPIED) >> s->cluster_bits); |
|
2535 if ((refcount == 1) != ((offset & QCOW_OFLAG_COPIED) != 0)) { |
|
2536 printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n", |
|
2537 offset, refcount); |
|
2538 } |
|
2539 } |
|
2540 offset &= ~QCOW_OFLAG_COPIED; |
|
2541 inc_refcounts(bs, refcount_table, |
|
2542 refcount_table_size, |
|
2543 offset, s->cluster_size); |
|
2544 } |
|
2545 } |
|
2546 } |
|
2547 inc_refcounts(bs, refcount_table, |
|
2548 refcount_table_size, |
|
2549 l2_offset, |
|
2550 s->cluster_size); |
|
2551 } |
|
2552 } |
|
2553 qemu_free(l1_table); |
|
2554 qemu_free(l2_table); |
|
2555 return 0; |
|
2556 fail: |
|
2557 printf("ERROR: I/O error in check_refcounts_l1\n"); |
|
2558 qemu_free(l1_table); |
|
2559 qemu_free(l2_table); |
|
2560 return -EIO; |
|
2561 } |
|
2562 |
|
2563 static void check_refcounts(BlockDriverState *bs) |
|
2564 { |
|
2565 BDRVQcowState *s = bs->opaque; |
|
2566 int64_t size; |
|
2567 int nb_clusters, refcount1, refcount2, i; |
|
2568 QCowSnapshot *sn; |
|
2569 uint16_t *refcount_table; |
|
2570 |
|
2571 size = bdrv_getlength(s->hd); |
|
2572 nb_clusters = size_to_clusters(s, size); |
|
2573 refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t)); |
|
2574 |
|
2575 /* header */ |
|
2576 inc_refcounts(bs, refcount_table, nb_clusters, |
|
2577 0, s->cluster_size); |
|
2578 |
|
2579 check_refcounts_l1(bs, refcount_table, nb_clusters, |
|
2580 s->l1_table_offset, s->l1_size, 1); |
|
2581 |
|
2582 /* snapshots */ |
|
2583 for(i = 0; i < s->nb_snapshots; i++) { |
|
2584 sn = s->snapshots + i; |
|
2585 check_refcounts_l1(bs, refcount_table, nb_clusters, |
|
2586 sn->l1_table_offset, sn->l1_size, 0); |
|
2587 } |
|
2588 inc_refcounts(bs, refcount_table, nb_clusters, |
|
2589 s->snapshots_offset, s->snapshots_size); |
|
2590 |
|
2591 /* refcount data */ |
|
2592 inc_refcounts(bs, refcount_table, nb_clusters, |
|
2593 s->refcount_table_offset, |
|
2594 s->refcount_table_size * sizeof(uint64_t)); |
|
2595 for(i = 0; i < s->refcount_table_size; i++) { |
|
2596 int64_t offset; |
|
2597 offset = s->refcount_table[i]; |
|
2598 if (offset != 0) { |
|
2599 inc_refcounts(bs, refcount_table, nb_clusters, |
|
2600 offset, s->cluster_size); |
|
2601 } |
|
2602 } |
|
2603 |
|
2604 /* compare ref counts */ |
|
2605 for(i = 0; i < nb_clusters; i++) { |
|
2606 refcount1 = get_refcount(bs, i); |
|
2607 refcount2 = refcount_table[i]; |
|
2608 if (refcount1 != refcount2) |
|
2609 printf("ERROR cluster %d refcount=%d reference=%d\n", |
|
2610 i, refcount1, refcount2); |
|
2611 } |
|
2612 |
|
2613 qemu_free(refcount_table); |
|
2614 } |
|
2615 |
|
2616 #if 0 |
|
2617 static void dump_refcounts(BlockDriverState *bs) |
|
2618 { |
|
2619 BDRVQcowState *s = bs->opaque; |
|
2620 int64_t nb_clusters, k, k1, size; |
|
2621 int refcount; |
|
2622 |
|
2623 size = bdrv_getlength(s->hd); |
|
2624 nb_clusters = size_to_clusters(s, size); |
|
2625 for(k = 0; k < nb_clusters;) { |
|
2626 k1 = k; |
|
2627 refcount = get_refcount(bs, k); |
|
2628 k++; |
|
2629 while (k < nb_clusters && get_refcount(bs, k) == refcount) |
|
2630 k++; |
|
2631 printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1); |
|
2632 } |
|
2633 } |
|
2634 #endif |
|
2635 #endif |
|
2636 |
|
2637 BlockDriver bdrv_qcow2 = { |
|
2638 "qcow2", |
|
2639 sizeof(BDRVQcowState), |
|
2640 qcow_probe, |
|
2641 qcow_open, |
|
2642 NULL, |
|
2643 NULL, |
|
2644 qcow_close, |
|
2645 qcow_create, |
|
2646 qcow_flush, |
|
2647 qcow_is_allocated, |
|
2648 qcow_set_key, |
|
2649 qcow_make_empty, |
|
2650 |
|
2651 .bdrv_aio_read = qcow_aio_read, |
|
2652 .bdrv_aio_write = qcow_aio_write, |
|
2653 .bdrv_aio_cancel = qcow_aio_cancel, |
|
2654 .aiocb_size = sizeof(QCowAIOCB), |
|
2655 .bdrv_write_compressed = qcow_write_compressed, |
|
2656 |
|
2657 .bdrv_snapshot_create = qcow_snapshot_create, |
|
2658 .bdrv_snapshot_goto = qcow_snapshot_goto, |
|
2659 .bdrv_snapshot_delete = qcow_snapshot_delete, |
|
2660 .bdrv_snapshot_list = qcow_snapshot_list, |
|
2661 .bdrv_get_info = qcow_get_info, |
|
2662 }; |