David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Block driver for the QCOW version 2 format |
| 3 | * |
| 4 | * Copyright (c) 2004-2006 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | #include <zlib.h> |
| 26 | |
| 27 | #include "qemu-common.h" |
| 28 | #include "block_int.h" |
| 29 | #include "block/qcow2.h" |
| 30 | |
| 31 | int qcow2_grow_l1_table(BlockDriverState *bs, int min_size) |
| 32 | { |
| 33 | BDRVQcowState *s = bs->opaque; |
| 34 | int new_l1_size, new_l1_size2, ret, i; |
| 35 | uint64_t *new_l1_table; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 36 | int64_t new_l1_table_offset; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 37 | uint8_t data[12]; |
| 38 | |
| 39 | new_l1_size = s->l1_size; |
| 40 | if (min_size <= new_l1_size) |
| 41 | return 0; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 42 | if (new_l1_size == 0) { |
| 43 | new_l1_size = 1; |
| 44 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 45 | while (min_size > new_l1_size) { |
| 46 | new_l1_size = (new_l1_size * 3 + 1) / 2; |
| 47 | } |
| 48 | #ifdef DEBUG_ALLOC2 |
| 49 | printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size); |
| 50 | #endif |
| 51 | |
| 52 | new_l1_size2 = sizeof(uint64_t) * new_l1_size; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 53 | new_l1_table = qemu_mallocz(align_offset(new_l1_size2, 512)); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 54 | memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t)); |
| 55 | |
| 56 | /* write new table (align to cluster) */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 57 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ALLOC_TABLE); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 58 | new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 59 | if (new_l1_table_offset < 0) { |
| 60 | qemu_free(new_l1_table); |
| 61 | return new_l1_table_offset; |
| 62 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 63 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 64 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 65 | for(i = 0; i < s->l1_size; i++) |
| 66 | new_l1_table[i] = cpu_to_be64(new_l1_table[i]); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 67 | ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2); |
| 68 | if (ret < 0) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 69 | goto fail; |
| 70 | for(i = 0; i < s->l1_size; i++) |
| 71 | new_l1_table[i] = be64_to_cpu(new_l1_table[i]); |
| 72 | |
| 73 | /* set new table */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 74 | BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 75 | cpu_to_be32w((uint32_t*)data, new_l1_size); |
| 76 | cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 77 | ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data)); |
| 78 | if (ret < 0) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 79 | goto fail; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 80 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 81 | qemu_free(s->l1_table); |
| 82 | qcow2_free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t)); |
| 83 | s->l1_table_offset = new_l1_table_offset; |
| 84 | s->l1_table = new_l1_table; |
| 85 | s->l1_size = new_l1_size; |
| 86 | return 0; |
| 87 | fail: |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 88 | qemu_free(new_l1_table); |
| 89 | qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2); |
| 90 | return ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | void qcow2_l2_cache_reset(BlockDriverState *bs) |
| 94 | { |
| 95 | BDRVQcowState *s = bs->opaque; |
| 96 | |
| 97 | memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
| 98 | memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
| 99 | memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
| 100 | } |
| 101 | |
| 102 | static inline int l2_cache_new_entry(BlockDriverState *bs) |
| 103 | { |
| 104 | BDRVQcowState *s = bs->opaque; |
| 105 | uint32_t min_count; |
| 106 | int min_index, i; |
| 107 | |
| 108 | /* find a new entry in the least used one */ |
| 109 | min_index = 0; |
| 110 | min_count = 0xffffffff; |
| 111 | for(i = 0; i < L2_CACHE_SIZE; i++) { |
| 112 | if (s->l2_cache_counts[i] < min_count) { |
| 113 | min_count = s->l2_cache_counts[i]; |
| 114 | min_index = i; |
| 115 | } |
| 116 | } |
| 117 | return min_index; |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * seek_l2_table |
| 122 | * |
| 123 | * seek l2_offset in the l2_cache table |
| 124 | * if not found, return NULL, |
| 125 | * if found, |
| 126 | * increments the l2 cache hit count of the entry, |
| 127 | * if counter overflow, divide by two all counters |
| 128 | * return the pointer to the l2 cache entry |
| 129 | * |
| 130 | */ |
| 131 | |
| 132 | static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset) |
| 133 | { |
| 134 | int i, j; |
| 135 | |
| 136 | for(i = 0; i < L2_CACHE_SIZE; i++) { |
| 137 | if (l2_offset == s->l2_cache_offsets[i]) { |
| 138 | /* increment the hit count */ |
| 139 | if (++s->l2_cache_counts[i] == 0xffffffff) { |
| 140 | for(j = 0; j < L2_CACHE_SIZE; j++) { |
| 141 | s->l2_cache_counts[j] >>= 1; |
| 142 | } |
| 143 | } |
| 144 | return s->l2_cache + (i << s->l2_bits); |
| 145 | } |
| 146 | } |
| 147 | return NULL; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * l2_load |
| 152 | * |
| 153 | * Loads a L2 table into memory. If the table is in the cache, the cache |
| 154 | * is used; otherwise the L2 table is loaded from the image file. |
| 155 | * |
| 156 | * Returns a pointer to the L2 table on success, or NULL if the read from |
| 157 | * the image file failed. |
| 158 | */ |
| 159 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 160 | static int l2_load(BlockDriverState *bs, uint64_t l2_offset, |
| 161 | uint64_t **l2_table) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 162 | { |
| 163 | BDRVQcowState *s = bs->opaque; |
| 164 | int min_index; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 165 | int ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 166 | |
| 167 | /* seek if the table for the given offset is in the cache */ |
| 168 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 169 | *l2_table = seek_l2_table(s, l2_offset); |
| 170 | if (*l2_table != NULL) { |
| 171 | return 0; |
| 172 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 173 | |
| 174 | /* not found: load a new entry in the least used one */ |
| 175 | |
| 176 | min_index = l2_cache_new_entry(bs); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 177 | *l2_table = s->l2_cache + (min_index << s->l2_bits); |
| 178 | |
| 179 | BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD); |
| 180 | ret = bdrv_pread(bs->file, l2_offset, *l2_table, |
| 181 | s->l2_size * sizeof(uint64_t)); |
| 182 | if (ret < 0) { |
| 183 | return ret; |
| 184 | } |
| 185 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 186 | s->l2_cache_offsets[min_index] = l2_offset; |
| 187 | s->l2_cache_counts[min_index] = 1; |
| 188 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 189 | return 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Writes one sector of the L1 table to the disk (can't update single entries |
| 194 | * and we really don't want bdrv_pread to perform a read-modify-write) |
| 195 | */ |
| 196 | #define L1_ENTRIES_PER_SECTOR (512 / 8) |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 197 | static int write_l1_entry(BlockDriverState *bs, int l1_index) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 198 | { |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 199 | BDRVQcowState *s = bs->opaque; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 200 | uint64_t buf[L1_ENTRIES_PER_SECTOR]; |
| 201 | int l1_start_index; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 202 | int i, ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 203 | |
| 204 | l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); |
| 205 | for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { |
| 206 | buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); |
| 207 | } |
| 208 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 209 | BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); |
| 210 | ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index, |
| 211 | buf, sizeof(buf)); |
| 212 | if (ret < 0) { |
| 213 | return ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 214 | } |
| 215 | |
| 216 | return 0; |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * l2_allocate |
| 221 | * |
| 222 | * Allocate a new l2 entry in the file. If l1_index points to an already |
| 223 | * used entry in the L2 table (i.e. we are doing a copy on write for the L2 |
| 224 | * table) copy the contents of the old L2 table into the newly allocated one. |
| 225 | * Otherwise the new table is initialized with zeros. |
| 226 | * |
| 227 | */ |
| 228 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 229 | static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 230 | { |
| 231 | BDRVQcowState *s = bs->opaque; |
| 232 | int min_index; |
| 233 | uint64_t old_l2_offset; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 234 | uint64_t *l2_table; |
| 235 | int64_t l2_offset; |
| 236 | int ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 237 | |
| 238 | old_l2_offset = s->l1_table[l1_index]; |
| 239 | |
| 240 | /* allocate a new l2 entry */ |
| 241 | |
| 242 | l2_offset = qcow2_alloc_clusters(bs, s->l2_size * sizeof(uint64_t)); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 243 | if (l2_offset < 0) { |
| 244 | return l2_offset; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 245 | } |
| 246 | |
| 247 | /* allocate a new entry in the l2 cache */ |
| 248 | |
| 249 | min_index = l2_cache_new_entry(bs); |
| 250 | l2_table = s->l2_cache + (min_index << s->l2_bits); |
| 251 | |
| 252 | if (old_l2_offset == 0) { |
| 253 | /* if there was no old l2 table, clear the new table */ |
| 254 | memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
| 255 | } else { |
| 256 | /* if there was an old l2 table, read it from the disk */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 257 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_COW_READ); |
| 258 | ret = bdrv_pread(bs->file, old_l2_offset, l2_table, |
| 259 | s->l2_size * sizeof(uint64_t)); |
| 260 | if (ret < 0) { |
| 261 | goto fail; |
| 262 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 263 | } |
| 264 | /* write the l2 table to the file */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 265 | BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE); |
| 266 | ret = bdrv_pwrite_sync(bs->file, l2_offset, l2_table, |
| 267 | s->l2_size * sizeof(uint64_t)); |
| 268 | if (ret < 0) { |
| 269 | goto fail; |
| 270 | } |
| 271 | |
| 272 | /* update the L1 entry */ |
| 273 | s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED; |
| 274 | ret = write_l1_entry(bs, l1_index); |
| 275 | if (ret < 0) { |
| 276 | goto fail; |
| 277 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 278 | |
| 279 | /* update the l2 cache entry */ |
| 280 | |
| 281 | s->l2_cache_offsets[min_index] = l2_offset; |
| 282 | s->l2_cache_counts[min_index] = 1; |
| 283 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 284 | *table = l2_table; |
| 285 | return 0; |
| 286 | |
| 287 | fail: |
| 288 | s->l1_table[l1_index] = old_l2_offset; |
| 289 | qcow2_l2_cache_reset(bs); |
| 290 | return ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 291 | } |
| 292 | |
| 293 | static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
| 294 | uint64_t *l2_table, uint64_t start, uint64_t mask) |
| 295 | { |
| 296 | int i; |
| 297 | uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask; |
| 298 | |
| 299 | if (!offset) |
| 300 | return 0; |
| 301 | |
| 302 | for (i = start; i < start + nb_clusters; i++) |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 303 | if (offset + (uint64_t) i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask)) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 304 | break; |
| 305 | |
| 306 | return (i - start); |
| 307 | } |
| 308 | |
| 309 | static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table) |
| 310 | { |
| 311 | int i = 0; |
| 312 | |
| 313 | while(nb_clusters-- && l2_table[i] == 0) |
| 314 | i++; |
| 315 | |
| 316 | return i; |
| 317 | } |
| 318 | |
| 319 | /* The crypt function is compatible with the linux cryptoloop |
| 320 | algorithm for < 4 GB images. NOTE: out_buf == in_buf is |
| 321 | supported */ |
| 322 | void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
| 323 | uint8_t *out_buf, const uint8_t *in_buf, |
| 324 | int nb_sectors, int enc, |
| 325 | const AES_KEY *key) |
| 326 | { |
| 327 | union { |
| 328 | uint64_t ll[2]; |
| 329 | uint8_t b[16]; |
| 330 | } ivec; |
| 331 | int i; |
| 332 | |
| 333 | for(i = 0; i < nb_sectors; i++) { |
| 334 | ivec.ll[0] = cpu_to_le64(sector_num); |
| 335 | ivec.ll[1] = 0; |
| 336 | AES_cbc_encrypt(in_buf, out_buf, 512, key, |
| 337 | ivec.b, enc); |
| 338 | sector_num++; |
| 339 | in_buf += 512; |
| 340 | out_buf += 512; |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 345 | static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
| 346 | uint8_t *buf, int nb_sectors) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 347 | { |
| 348 | BDRVQcowState *s = bs->opaque; |
| 349 | int ret, index_in_cluster, n, n1; |
| 350 | uint64_t cluster_offset; |
| 351 | |
| 352 | while (nb_sectors > 0) { |
| 353 | n = nb_sectors; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 354 | |
| 355 | ret = qcow2_get_cluster_offset(bs, sector_num << 9, &n, |
| 356 | &cluster_offset); |
| 357 | if (ret < 0) { |
| 358 | return ret; |
| 359 | } |
| 360 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 361 | index_in_cluster = sector_num & (s->cluster_sectors - 1); |
| 362 | if (!cluster_offset) { |
| 363 | if (bs->backing_hd) { |
| 364 | /* read from the base image */ |
| 365 | n1 = qcow2_backing_read1(bs->backing_hd, sector_num, buf, n); |
| 366 | if (n1 > 0) { |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 367 | BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 368 | ret = bdrv_read(bs->backing_hd, sector_num, buf, n1); |
| 369 | if (ret < 0) |
| 370 | return -1; |
| 371 | } |
| 372 | } else { |
| 373 | memset(buf, 0, 512 * n); |
| 374 | } |
| 375 | } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 376 | if (qcow2_decompress_cluster(bs, cluster_offset) < 0) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 377 | return -1; |
| 378 | memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
| 379 | } else { |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 380 | BLKDBG_EVENT(bs->file, BLKDBG_READ); |
| 381 | ret = bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 382 | if (ret != n * 512) |
| 383 | return -1; |
| 384 | if (s->crypt_method) { |
| 385 | qcow2_encrypt_sectors(s, sector_num, buf, buf, n, 0, |
| 386 | &s->aes_decrypt_key); |
| 387 | } |
| 388 | } |
| 389 | nb_sectors -= n; |
| 390 | sector_num += n; |
| 391 | buf += n * 512; |
| 392 | } |
| 393 | return 0; |
| 394 | } |
| 395 | |
| 396 | static int copy_sectors(BlockDriverState *bs, uint64_t start_sect, |
| 397 | uint64_t cluster_offset, int n_start, int n_end) |
| 398 | { |
| 399 | BDRVQcowState *s = bs->opaque; |
| 400 | int n, ret; |
| 401 | |
| 402 | n = n_end - n_start; |
| 403 | if (n <= 0) |
| 404 | return 0; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 405 | BLKDBG_EVENT(bs->file, BLKDBG_COW_READ); |
| 406 | ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 407 | if (ret < 0) |
| 408 | return ret; |
| 409 | if (s->crypt_method) { |
| 410 | qcow2_encrypt_sectors(s, start_sect + n_start, |
| 411 | s->cluster_data, |
| 412 | s->cluster_data, n, 1, |
| 413 | &s->aes_encrypt_key); |
| 414 | } |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 415 | BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE); |
| 416 | ret = bdrv_write_sync(bs->file, (cluster_offset >> 9) + n_start, |
| 417 | s->cluster_data, n); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 418 | if (ret < 0) |
| 419 | return ret; |
| 420 | return 0; |
| 421 | } |
| 422 | |
| 423 | |
| 424 | /* |
| 425 | * get_cluster_offset |
| 426 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 427 | * For a given offset of the disk image, find the cluster offset in |
| 428 | * qcow2 file. The offset is stored in *cluster_offset. |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 429 | * |
| 430 | * on entry, *num is the number of contiguous clusters we'd like to |
| 431 | * access following offset. |
| 432 | * |
| 433 | * on exit, *num is the number of contiguous clusters we can read. |
| 434 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 435 | * Return 0, if the offset is found |
| 436 | * Return -errno, otherwise. |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 437 | * |
| 438 | */ |
| 439 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 440 | int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, |
| 441 | int *num, uint64_t *cluster_offset) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 442 | { |
| 443 | BDRVQcowState *s = bs->opaque; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 444 | unsigned int l1_index, l2_index; |
| 445 | uint64_t l2_offset, *l2_table; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 446 | int l1_bits, c; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 447 | unsigned int index_in_cluster, nb_clusters; |
| 448 | uint64_t nb_available, nb_needed; |
| 449 | int ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 450 | |
| 451 | index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1); |
| 452 | nb_needed = *num + index_in_cluster; |
| 453 | |
| 454 | l1_bits = s->l2_bits + s->cluster_bits; |
| 455 | |
| 456 | /* compute how many bytes there are between the offset and |
| 457 | * the end of the l1 entry |
| 458 | */ |
| 459 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 460 | nb_available = (1ULL << l1_bits) - (offset & ((1ULL << l1_bits) - 1)); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 461 | |
| 462 | /* compute the number of available sectors */ |
| 463 | |
| 464 | nb_available = (nb_available >> 9) + index_in_cluster; |
| 465 | |
| 466 | if (nb_needed > nb_available) { |
| 467 | nb_needed = nb_available; |
| 468 | } |
| 469 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 470 | *cluster_offset = 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 471 | |
| 472 | /* seek the the l2 offset in the l1 table */ |
| 473 | |
| 474 | l1_index = offset >> l1_bits; |
| 475 | if (l1_index >= s->l1_size) |
| 476 | goto out; |
| 477 | |
| 478 | l2_offset = s->l1_table[l1_index]; |
| 479 | |
| 480 | /* seek the l2 table of the given l2 offset */ |
| 481 | |
| 482 | if (!l2_offset) |
| 483 | goto out; |
| 484 | |
| 485 | /* load the l2 table in memory */ |
| 486 | |
| 487 | l2_offset &= ~QCOW_OFLAG_COPIED; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 488 | ret = l2_load(bs, l2_offset, &l2_table); |
| 489 | if (ret < 0) { |
| 490 | return ret; |
| 491 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 492 | |
| 493 | /* find the cluster offset for the given disk offset */ |
| 494 | |
| 495 | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 496 | *cluster_offset = be64_to_cpu(l2_table[l2_index]); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 497 | nb_clusters = size_to_clusters(s, nb_needed << 9); |
| 498 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 499 | if (!*cluster_offset) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 500 | /* how many empty clusters ? */ |
| 501 | c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]); |
| 502 | } else { |
| 503 | /* how many allocated clusters ? */ |
| 504 | c = count_contiguous_clusters(nb_clusters, s->cluster_size, |
| 505 | &l2_table[l2_index], 0, QCOW_OFLAG_COPIED); |
| 506 | } |
| 507 | |
| 508 | nb_available = (c * s->cluster_sectors); |
| 509 | out: |
| 510 | if (nb_available > nb_needed) |
| 511 | nb_available = nb_needed; |
| 512 | |
| 513 | *num = nb_available - index_in_cluster; |
| 514 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 515 | *cluster_offset &=~QCOW_OFLAG_COPIED; |
| 516 | return 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 517 | } |
| 518 | |
| 519 | /* |
| 520 | * get_cluster_table |
| 521 | * |
| 522 | * for a given disk offset, load (and allocate if needed) |
| 523 | * the l2 table. |
| 524 | * |
| 525 | * the l2 table offset in the qcow2 file and the cluster index |
| 526 | * in the l2 table are given to the caller. |
| 527 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 528 | * Returns 0 on success, -errno in failure case |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 529 | */ |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 530 | static int get_cluster_table(BlockDriverState *bs, uint64_t offset, |
| 531 | uint64_t **new_l2_table, |
| 532 | uint64_t *new_l2_offset, |
| 533 | int *new_l2_index) |
| 534 | { |
| 535 | BDRVQcowState *s = bs->opaque; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 536 | unsigned int l1_index, l2_index; |
| 537 | uint64_t l2_offset; |
| 538 | uint64_t *l2_table = NULL; |
| 539 | int ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 540 | |
| 541 | /* seek the the l2 offset in the l1 table */ |
| 542 | |
| 543 | l1_index = offset >> (s->l2_bits + s->cluster_bits); |
| 544 | if (l1_index >= s->l1_size) { |
| 545 | ret = qcow2_grow_l1_table(bs, l1_index + 1); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 546 | if (ret < 0) { |
| 547 | return ret; |
| 548 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 549 | } |
| 550 | l2_offset = s->l1_table[l1_index]; |
| 551 | |
| 552 | /* seek the l2 table of the given l2 offset */ |
| 553 | |
| 554 | if (l2_offset & QCOW_OFLAG_COPIED) { |
| 555 | /* load the l2 table in memory */ |
| 556 | l2_offset &= ~QCOW_OFLAG_COPIED; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 557 | ret = l2_load(bs, l2_offset, &l2_table); |
| 558 | if (ret < 0) { |
| 559 | return ret; |
| 560 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 561 | } else { |
| 562 | if (l2_offset) |
| 563 | qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t)); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 564 | ret = l2_allocate(bs, l1_index, &l2_table); |
| 565 | if (ret < 0) { |
| 566 | return ret; |
| 567 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 568 | l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED; |
| 569 | } |
| 570 | |
| 571 | /* find the cluster offset for the given disk offset */ |
| 572 | |
| 573 | l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); |
| 574 | |
| 575 | *new_l2_table = l2_table; |
| 576 | *new_l2_offset = l2_offset; |
| 577 | *new_l2_index = l2_index; |
| 578 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 579 | return 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 580 | } |
| 581 | |
| 582 | /* |
| 583 | * alloc_compressed_cluster_offset |
| 584 | * |
| 585 | * For a given offset of the disk image, return cluster offset in |
| 586 | * qcow2 file. |
| 587 | * |
| 588 | * If the offset is not found, allocate a new compressed cluster. |
| 589 | * |
| 590 | * Return the cluster offset if successful, |
| 591 | * Return 0, otherwise. |
| 592 | * |
| 593 | */ |
| 594 | |
| 595 | uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, |
| 596 | uint64_t offset, |
| 597 | int compressed_size) |
| 598 | { |
| 599 | BDRVQcowState *s = bs->opaque; |
| 600 | int l2_index, ret; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 601 | uint64_t l2_offset, *l2_table; |
| 602 | int64_t cluster_offset; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 603 | int nb_csectors; |
| 604 | |
| 605 | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 606 | if (ret < 0) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 607 | return 0; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 608 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 609 | |
| 610 | cluster_offset = be64_to_cpu(l2_table[l2_index]); |
| 611 | if (cluster_offset & QCOW_OFLAG_COPIED) |
| 612 | return cluster_offset & ~QCOW_OFLAG_COPIED; |
| 613 | |
| 614 | if (cluster_offset) |
| 615 | qcow2_free_any_clusters(bs, cluster_offset, 1); |
| 616 | |
| 617 | cluster_offset = qcow2_alloc_bytes(bs, compressed_size); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 618 | if (cluster_offset < 0) { |
| 619 | return 0; |
| 620 | } |
| 621 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 622 | nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) - |
| 623 | (cluster_offset >> 9); |
| 624 | |
| 625 | cluster_offset |= QCOW_OFLAG_COMPRESSED | |
| 626 | ((uint64_t)nb_csectors << s->csize_shift); |
| 627 | |
| 628 | /* update L2 table */ |
| 629 | |
| 630 | /* compressed clusters never have the copied flag */ |
| 631 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 632 | BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 633 | l2_table[l2_index] = cpu_to_be64(cluster_offset); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 634 | if (bdrv_pwrite_sync(bs->file, |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 635 | l2_offset + l2_index * sizeof(uint64_t), |
| 636 | l2_table + l2_index, |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 637 | sizeof(uint64_t)) < 0) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 638 | return 0; |
| 639 | |
| 640 | return cluster_offset; |
| 641 | } |
| 642 | |
| 643 | /* |
| 644 | * Write L2 table updates to disk, writing whole sectors to avoid a |
| 645 | * read-modify-write in bdrv_pwrite |
| 646 | */ |
| 647 | #define L2_ENTRIES_PER_SECTOR (512 / 8) |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 648 | static int write_l2_entries(BlockDriverState *bs, uint64_t *l2_table, |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 649 | uint64_t l2_offset, int l2_index, int num) |
| 650 | { |
| 651 | int l2_start_index = l2_index & ~(L1_ENTRIES_PER_SECTOR - 1); |
| 652 | int start_offset = (8 * l2_index) & ~511; |
| 653 | int end_offset = (8 * (l2_index + num) + 511) & ~511; |
| 654 | size_t len = end_offset - start_offset; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 655 | int ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 656 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 657 | BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE); |
| 658 | ret = bdrv_pwrite_sync(bs->file, l2_offset + start_offset, |
| 659 | &l2_table[l2_start_index], len); |
| 660 | if (ret < 0) { |
| 661 | return ret; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 662 | } |
| 663 | |
| 664 | return 0; |
| 665 | } |
| 666 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 667 | int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 668 | { |
| 669 | BDRVQcowState *s = bs->opaque; |
| 670 | int i, j = 0, l2_index, ret; |
| 671 | uint64_t *old_cluster, start_sect, l2_offset, *l2_table; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 672 | uint64_t cluster_offset = m->cluster_offset; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 673 | |
| 674 | if (m->nb_clusters == 0) |
| 675 | return 0; |
| 676 | |
| 677 | old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t)); |
| 678 | |
| 679 | /* copy content of unmodified sectors */ |
| 680 | start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9; |
| 681 | if (m->n_start) { |
| 682 | ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start); |
| 683 | if (ret < 0) |
| 684 | goto err; |
| 685 | } |
| 686 | |
| 687 | if (m->nb_available & (s->cluster_sectors - 1)) { |
| 688 | uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1); |
| 689 | ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9), |
| 690 | m->nb_available - end, s->cluster_sectors); |
| 691 | if (ret < 0) |
| 692 | goto err; |
| 693 | } |
| 694 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 695 | /* update L2 table */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 696 | ret = get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index); |
| 697 | if (ret < 0) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 698 | goto err; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 699 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 700 | |
| 701 | for (i = 0; i < m->nb_clusters; i++) { |
| 702 | /* if two concurrent writes happen to the same unallocated cluster |
| 703 | * each write allocates separate cluster and writes data concurrently. |
| 704 | * The first one to complete updates l2 table with pointer to its |
| 705 | * cluster the second one has to do RMW (which is done above by |
| 706 | * copy_sectors()), update l2 table with its cluster pointer and free |
| 707 | * old cluster. This is what this loop does */ |
| 708 | if(l2_table[l2_index + i] != 0) |
| 709 | old_cluster[j++] = l2_table[l2_index + i]; |
| 710 | |
| 711 | l2_table[l2_index + i] = cpu_to_be64((cluster_offset + |
| 712 | (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |
| 713 | } |
| 714 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 715 | ret = write_l2_entries(bs, l2_table, l2_offset, l2_index, m->nb_clusters); |
| 716 | if (ret < 0) { |
| 717 | qcow2_l2_cache_reset(bs); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 718 | goto err; |
| 719 | } |
| 720 | |
| 721 | for (i = 0; i < j; i++) |
| 722 | qcow2_free_any_clusters(bs, |
| 723 | be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1); |
| 724 | |
| 725 | ret = 0; |
| 726 | err: |
| 727 | qemu_free(old_cluster); |
| 728 | return ret; |
| 729 | } |
| 730 | |
| 731 | /* |
| 732 | * alloc_cluster_offset |
| 733 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 734 | * For a given offset of the disk image, return cluster offset in qcow2 file. |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 735 | * If the offset is not found, allocate a new cluster. |
| 736 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 737 | * If the cluster was already allocated, m->nb_clusters is set to 0, |
| 738 | * m->depends_on is set to NULL and the other fields in m are meaningless. |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 739 | * |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 740 | * If the cluster is newly allocated, m->nb_clusters is set to the number of |
| 741 | * contiguous clusters that have been allocated. This may be 0 if the request |
| 742 | * conflict with another write request in flight; in this case, m->depends_on |
| 743 | * is set and the remaining fields of m are meaningless. |
| 744 | * |
| 745 | * If m->nb_clusters is non-zero, the other fields of m are valid and contain |
| 746 | * information about the first allocated cluster. |
| 747 | * |
| 748 | * Return 0 on success and -errno in error cases |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 749 | */ |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 750 | int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, |
| 751 | int n_start, int n_end, int *num, QCowL2Meta *m) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 752 | { |
| 753 | BDRVQcowState *s = bs->opaque; |
| 754 | int l2_index, ret; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 755 | uint64_t l2_offset, *l2_table; |
| 756 | int64_t cluster_offset; |
| 757 | unsigned int nb_clusters, i = 0; |
| 758 | QCowL2Meta *old_alloc; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 759 | |
| 760 | ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 761 | if (ret < 0) { |
| 762 | return ret; |
| 763 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 764 | |
| 765 | nb_clusters = size_to_clusters(s, n_end << 9); |
| 766 | |
| 767 | nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); |
| 768 | |
| 769 | cluster_offset = be64_to_cpu(l2_table[l2_index]); |
| 770 | |
| 771 | /* We keep all QCOW_OFLAG_COPIED clusters */ |
| 772 | |
| 773 | if (cluster_offset & QCOW_OFLAG_COPIED) { |
| 774 | nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size, |
| 775 | &l2_table[l2_index], 0, 0); |
| 776 | |
| 777 | cluster_offset &= ~QCOW_OFLAG_COPIED; |
| 778 | m->nb_clusters = 0; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 779 | m->depends_on = NULL; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 780 | |
| 781 | goto out; |
| 782 | } |
| 783 | |
| 784 | /* for the moment, multiple compressed clusters are not managed */ |
| 785 | |
| 786 | if (cluster_offset & QCOW_OFLAG_COMPRESSED) |
| 787 | nb_clusters = 1; |
| 788 | |
| 789 | /* how many available clusters ? */ |
| 790 | |
| 791 | while (i < nb_clusters) { |
| 792 | i += count_contiguous_clusters(nb_clusters - i, s->cluster_size, |
| 793 | &l2_table[l2_index], i, 0); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 794 | if ((i >= nb_clusters) || be64_to_cpu(l2_table[l2_index + i])) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 795 | break; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 796 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 797 | |
| 798 | i += count_contiguous_free_clusters(nb_clusters - i, |
| 799 | &l2_table[l2_index + i]); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 800 | if (i >= nb_clusters) { |
| 801 | break; |
| 802 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 803 | |
| 804 | cluster_offset = be64_to_cpu(l2_table[l2_index + i]); |
| 805 | |
| 806 | if ((cluster_offset & QCOW_OFLAG_COPIED) || |
| 807 | (cluster_offset & QCOW_OFLAG_COMPRESSED)) |
| 808 | break; |
| 809 | } |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 810 | assert(i <= nb_clusters); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 811 | nb_clusters = i; |
| 812 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 813 | /* |
| 814 | * Check if there already is an AIO write request in flight which allocates |
| 815 | * the same cluster. In this case we need to wait until the previous |
| 816 | * request has completed and updated the L2 table accordingly. |
| 817 | */ |
| 818 | QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { |
| 819 | |
| 820 | uint64_t end_offset = offset + nb_clusters * s->cluster_size; |
| 821 | uint64_t old_offset = old_alloc->offset; |
| 822 | uint64_t old_end_offset = old_alloc->offset + |
| 823 | old_alloc->nb_clusters * s->cluster_size; |
| 824 | |
| 825 | if (end_offset < old_offset || offset > old_end_offset) { |
| 826 | /* No intersection */ |
| 827 | } else { |
| 828 | if (offset < old_offset) { |
| 829 | /* Stop at the start of a running allocation */ |
| 830 | nb_clusters = (old_offset - offset) >> s->cluster_bits; |
| 831 | } else { |
| 832 | nb_clusters = 0; |
| 833 | } |
| 834 | |
| 835 | if (nb_clusters == 0) { |
| 836 | /* Set dependency and wait for a callback */ |
| 837 | m->depends_on = old_alloc; |
| 838 | m->nb_clusters = 0; |
| 839 | *num = 0; |
| 840 | return 0; |
| 841 | } |
| 842 | } |
| 843 | } |
| 844 | |
Ot ten Thije | 7fd67eb | 2010-07-29 10:26:01 +0100 | [diff] [blame] | 845 | if (!nb_clusters) { |
| 846 | abort(); |
| 847 | } |
| 848 | |
| 849 | QLIST_INSERT_HEAD(&s->cluster_allocs, m, next_in_flight); |
| 850 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 851 | /* allocate a new cluster */ |
| 852 | |
| 853 | cluster_offset = qcow2_alloc_clusters(bs, nb_clusters * s->cluster_size); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 854 | if (cluster_offset < 0) { |
| 855 | QLIST_REMOVE(m, next_in_flight); |
| 856 | return cluster_offset; |
| 857 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 858 | |
| 859 | /* save info needed for meta data update */ |
| 860 | m->offset = offset; |
| 861 | m->n_start = n_start; |
| 862 | m->nb_clusters = nb_clusters; |
| 863 | |
| 864 | out: |
| 865 | m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 866 | m->cluster_offset = cluster_offset; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 867 | |
| 868 | *num = m->nb_available - n_start; |
| 869 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 870 | return 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 871 | } |
| 872 | |
| 873 | static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
| 874 | const uint8_t *buf, int buf_size) |
| 875 | { |
| 876 | z_stream strm1, *strm = &strm1; |
| 877 | int ret, out_len; |
| 878 | |
| 879 | memset(strm, 0, sizeof(*strm)); |
| 880 | |
| 881 | strm->next_in = (uint8_t *)buf; |
| 882 | strm->avail_in = buf_size; |
| 883 | strm->next_out = out_buf; |
| 884 | strm->avail_out = out_buf_size; |
| 885 | |
| 886 | ret = inflateInit2(strm, -12); |
| 887 | if (ret != Z_OK) |
| 888 | return -1; |
| 889 | ret = inflate(strm, Z_FINISH); |
| 890 | out_len = strm->next_out - out_buf; |
| 891 | if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || |
| 892 | out_len != out_buf_size) { |
| 893 | inflateEnd(strm); |
| 894 | return -1; |
| 895 | } |
| 896 | inflateEnd(strm); |
| 897 | return 0; |
| 898 | } |
| 899 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 900 | int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 901 | { |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 902 | BDRVQcowState *s = bs->opaque; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 903 | int ret, csize, nb_csectors, sector_offset; |
| 904 | uint64_t coffset; |
| 905 | |
| 906 | coffset = cluster_offset & s->cluster_offset_mask; |
| 907 | if (s->cluster_cache_offset != coffset) { |
| 908 | nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1; |
| 909 | sector_offset = coffset & 511; |
| 910 | csize = nb_csectors * 512 - sector_offset; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 911 | BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); |
| 912 | ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data, nb_csectors); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 913 | if (ret < 0) { |
| 914 | return -1; |
| 915 | } |
| 916 | if (decompress_buffer(s->cluster_cache, s->cluster_size, |
| 917 | s->cluster_data + sector_offset, csize) < 0) { |
| 918 | return -1; |
| 919 | } |
| 920 | s->cluster_cache_offset = coffset; |
| 921 | } |
| 922 | return 0; |
| 923 | } |