Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Bitmaps for the QCOW version 2 format |
| 3 | * |
| 4 | * Copyright (c) 2014-2017 Vladimir Sementsov-Ogievskiy |
| 5 | * |
| 6 | * This file is derived from qcow2-snapshot.c, original copyright: |
| 7 | * Copyright (c) 2004-2006 Fabrice Bellard |
| 8 | * |
| 9 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 10 | * of this software and associated documentation files (the "Software"), to deal |
| 11 | * in the Software without restriction, including without limitation the rights |
| 12 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 13 | * copies of the Software, and to permit persons to whom the Software is |
| 14 | * furnished to do so, subject to the following conditions: |
| 15 | * |
| 16 | * The above copyright notice and this permission notice shall be included in |
| 17 | * all copies or substantial portions of the Software. |
| 18 | * |
| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 20 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 22 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 23 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 24 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 25 | * THE SOFTWARE. |
| 26 | */ |
| 27 | |
| 28 | #include "qemu/osdep.h" |
| 29 | #include "qapi/error.h" |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 30 | #include "qemu/cutils.h" |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 31 | |
| 32 | #include "block/block_int.h" |
| 33 | #include "block/qcow2.h" |
| 34 | |
| 35 | /* NOTICE: BME here means Bitmaps Extension and used as a namespace for |
| 36 | * _internal_ constants. Please do not use this _internal_ abbreviation for |
| 37 | * other needs and/or outside of this file. */ |
| 38 | |
| 39 | /* Bitmap directory entry constraints */ |
| 40 | #define BME_MAX_TABLE_SIZE 0x8000000 |
| 41 | #define BME_MAX_PHYS_SIZE 0x20000000 /* restrict BdrvDirtyBitmap size in RAM */ |
| 42 | #define BME_MAX_GRANULARITY_BITS 31 |
| 43 | #define BME_MIN_GRANULARITY_BITS 9 |
| 44 | #define BME_MAX_NAME_SIZE 1023 |
| 45 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 46 | #if BME_MAX_TABLE_SIZE * 8ULL > INT_MAX |
| 47 | #error In the code bitmap table physical size assumed to fit into int |
| 48 | #endif |
| 49 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 50 | /* Bitmap directory entry flags */ |
| 51 | #define BME_RESERVED_FLAGS 0xfffffffcU |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 52 | #define BME_FLAG_IN_USE (1U << 0) |
| 53 | #define BME_FLAG_AUTO (1U << 1) |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 54 | |
| 55 | /* bits [1, 8] U [56, 63] are reserved */ |
| 56 | #define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001feULL |
| 57 | #define BME_TABLE_ENTRY_OFFSET_MASK 0x00fffffffffffe00ULL |
| 58 | #define BME_TABLE_ENTRY_FLAG_ALL_ONES (1ULL << 0) |
| 59 | |
| 60 | typedef struct QEMU_PACKED Qcow2BitmapDirEntry { |
| 61 | /* header is 8 byte aligned */ |
| 62 | uint64_t bitmap_table_offset; |
| 63 | |
| 64 | uint32_t bitmap_table_size; |
| 65 | uint32_t flags; |
| 66 | |
| 67 | uint8_t type; |
| 68 | uint8_t granularity_bits; |
| 69 | uint16_t name_size; |
| 70 | uint32_t extra_data_size; |
| 71 | /* extra data follows */ |
| 72 | /* name follows */ |
| 73 | } Qcow2BitmapDirEntry; |
| 74 | |
| 75 | typedef struct Qcow2BitmapTable { |
| 76 | uint64_t offset; |
| 77 | uint32_t size; /* number of 64bit entries */ |
| 78 | QSIMPLEQ_ENTRY(Qcow2BitmapTable) entry; |
| 79 | } Qcow2BitmapTable; |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 80 | typedef QSIMPLEQ_HEAD(Qcow2BitmapTableList, Qcow2BitmapTable) |
| 81 | Qcow2BitmapTableList; |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 82 | |
| 83 | typedef struct Qcow2Bitmap { |
| 84 | Qcow2BitmapTable table; |
| 85 | uint32_t flags; |
| 86 | uint8_t granularity_bits; |
| 87 | char *name; |
| 88 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 89 | BdrvDirtyBitmap *dirty_bitmap; |
| 90 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 91 | QSIMPLEQ_ENTRY(Qcow2Bitmap) entry; |
| 92 | } Qcow2Bitmap; |
| 93 | typedef QSIMPLEQ_HEAD(Qcow2BitmapList, Qcow2Bitmap) Qcow2BitmapList; |
| 94 | |
| 95 | typedef enum BitmapType { |
| 96 | BT_DIRTY_TRACKING_BITMAP = 1 |
| 97 | } BitmapType; |
| 98 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 99 | static inline bool can_write(BlockDriverState *bs) |
| 100 | { |
| 101 | return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); |
| 102 | } |
| 103 | |
| 104 | static int update_header_sync(BlockDriverState *bs) |
| 105 | { |
| 106 | int ret; |
| 107 | |
| 108 | ret = qcow2_update_header(bs); |
| 109 | if (ret < 0) { |
| 110 | return ret; |
| 111 | } |
| 112 | |
| 113 | return bdrv_flush(bs); |
| 114 | } |
| 115 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 116 | static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size) |
| 117 | { |
| 118 | size_t i; |
| 119 | |
| 120 | for (i = 0; i < size; ++i) { |
| 121 | cpu_to_be64s(&bitmap_table[i]); |
| 122 | } |
| 123 | } |
| 124 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 125 | static int check_table_entry(uint64_t entry, int cluster_size) |
| 126 | { |
| 127 | uint64_t offset; |
| 128 | |
| 129 | if (entry & BME_TABLE_ENTRY_RESERVED_MASK) { |
| 130 | return -EINVAL; |
| 131 | } |
| 132 | |
| 133 | offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
| 134 | if (offset != 0) { |
| 135 | /* if offset specified, bit 0 is reserved */ |
| 136 | if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { |
| 137 | return -EINVAL; |
| 138 | } |
| 139 | |
| 140 | if (offset % cluster_size != 0) { |
| 141 | return -EINVAL; |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 148 | static int check_constraints_on_bitmap(BlockDriverState *bs, |
| 149 | const char *name, |
| 150 | uint32_t granularity, |
| 151 | Error **errp) |
| 152 | { |
| 153 | BDRVQcow2State *s = bs->opaque; |
| 154 | int granularity_bits = ctz32(granularity); |
| 155 | int64_t len = bdrv_getlength(bs); |
| 156 | |
| 157 | assert(granularity > 0); |
| 158 | assert((granularity & (granularity - 1)) == 0); |
| 159 | |
| 160 | if (len < 0) { |
| 161 | error_setg_errno(errp, -len, "Failed to get size of '%s'", |
| 162 | bdrv_get_device_or_node_name(bs)); |
| 163 | return len; |
| 164 | } |
| 165 | |
| 166 | if (granularity_bits > BME_MAX_GRANULARITY_BITS) { |
| 167 | error_setg(errp, "Granularity exceeds maximum (%llu bytes)", |
| 168 | 1ULL << BME_MAX_GRANULARITY_BITS); |
| 169 | return -EINVAL; |
| 170 | } |
| 171 | if (granularity_bits < BME_MIN_GRANULARITY_BITS) { |
| 172 | error_setg(errp, "Granularity is under minimum (%llu bytes)", |
| 173 | 1ULL << BME_MIN_GRANULARITY_BITS); |
| 174 | return -EINVAL; |
| 175 | } |
| 176 | |
| 177 | if ((len > (uint64_t)BME_MAX_PHYS_SIZE << granularity_bits) || |
| 178 | (len > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size << |
| 179 | granularity_bits)) |
| 180 | { |
| 181 | error_setg(errp, "Too much space will be occupied by the bitmap. " |
| 182 | "Use larger granularity"); |
| 183 | return -EINVAL; |
| 184 | } |
| 185 | |
| 186 | if (strlen(name) > BME_MAX_NAME_SIZE) { |
| 187 | error_setg(errp, "Name length exceeds maximum (%u characters)", |
| 188 | BME_MAX_NAME_SIZE); |
| 189 | return -EINVAL; |
| 190 | } |
| 191 | |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table, |
| 196 | uint32_t bitmap_table_size) |
| 197 | { |
| 198 | BDRVQcow2State *s = bs->opaque; |
| 199 | int i; |
| 200 | |
| 201 | for (i = 0; i < bitmap_table_size; ++i) { |
| 202 | uint64_t addr = bitmap_table[i] & BME_TABLE_ENTRY_OFFSET_MASK; |
| 203 | if (!addr) { |
| 204 | continue; |
| 205 | } |
| 206 | |
| 207 | qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_OTHER); |
| 208 | bitmap_table[i] = 0; |
| 209 | } |
| 210 | } |
| 211 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 212 | static int bitmap_table_load(BlockDriverState *bs, Qcow2BitmapTable *tb, |
| 213 | uint64_t **bitmap_table) |
| 214 | { |
| 215 | int ret; |
| 216 | BDRVQcow2State *s = bs->opaque; |
| 217 | uint32_t i; |
| 218 | uint64_t *table; |
| 219 | |
| 220 | assert(tb->size != 0); |
| 221 | table = g_try_new(uint64_t, tb->size); |
| 222 | if (table == NULL) { |
| 223 | return -ENOMEM; |
| 224 | } |
| 225 | |
| 226 | assert(tb->size <= BME_MAX_TABLE_SIZE); |
| 227 | ret = bdrv_pread(bs->file, tb->offset, |
| 228 | table, tb->size * sizeof(uint64_t)); |
| 229 | if (ret < 0) { |
| 230 | goto fail; |
| 231 | } |
| 232 | |
| 233 | for (i = 0; i < tb->size; ++i) { |
| 234 | be64_to_cpus(&table[i]); |
| 235 | ret = check_table_entry(table[i], s->cluster_size); |
| 236 | if (ret < 0) { |
| 237 | goto fail; |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | *bitmap_table = table; |
| 242 | return 0; |
| 243 | |
| 244 | fail: |
| 245 | g_free(table); |
| 246 | |
| 247 | return ret; |
| 248 | } |
| 249 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 250 | static int free_bitmap_clusters(BlockDriverState *bs, Qcow2BitmapTable *tb) |
| 251 | { |
| 252 | int ret; |
| 253 | uint64_t *bitmap_table; |
| 254 | |
| 255 | ret = bitmap_table_load(bs, tb, &bitmap_table); |
| 256 | if (ret < 0) { |
| 257 | assert(bitmap_table == NULL); |
| 258 | return ret; |
| 259 | } |
| 260 | |
| 261 | clear_bitmap_table(bs, bitmap_table, tb->size); |
| 262 | qcow2_free_clusters(bs, tb->offset, tb->size * sizeof(uint64_t), |
| 263 | QCOW2_DISCARD_OTHER); |
| 264 | g_free(bitmap_table); |
| 265 | |
| 266 | tb->offset = 0; |
| 267 | tb->size = 0; |
| 268 | |
| 269 | return 0; |
| 270 | } |
| 271 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 272 | /* This function returns the number of disk sectors covered by a single qcow2 |
| 273 | * cluster of bitmap data. */ |
| 274 | static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s, |
| 275 | const BdrvDirtyBitmap *bitmap) |
| 276 | { |
| 277 | uint32_t sector_granularity = |
| 278 | bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS; |
| 279 | |
| 280 | return (uint64_t)sector_granularity * (s->cluster_size << 3); |
| 281 | } |
| 282 | |
| 283 | /* load_bitmap_data |
| 284 | * @bitmap_table entries must satisfy specification constraints. |
| 285 | * @bitmap must be cleared */ |
| 286 | static int load_bitmap_data(BlockDriverState *bs, |
| 287 | const uint64_t *bitmap_table, |
| 288 | uint32_t bitmap_table_size, |
| 289 | BdrvDirtyBitmap *bitmap) |
| 290 | { |
| 291 | int ret = 0; |
| 292 | BDRVQcow2State *s = bs->opaque; |
| 293 | uint64_t sector, sbc; |
| 294 | uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); |
| 295 | uint8_t *buf = NULL; |
| 296 | uint64_t i, tab_size = |
| 297 | size_to_clusters(s, |
| 298 | bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size)); |
| 299 | |
| 300 | if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) { |
| 301 | return -EINVAL; |
| 302 | } |
| 303 | |
| 304 | buf = g_malloc(s->cluster_size); |
| 305 | sbc = sectors_covered_by_bitmap_cluster(s, bitmap); |
| 306 | for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) { |
| 307 | uint64_t count = MIN(bm_size - sector, sbc); |
| 308 | uint64_t entry = bitmap_table[i]; |
| 309 | uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
| 310 | |
| 311 | assert(check_table_entry(entry, s->cluster_size) == 0); |
| 312 | |
| 313 | if (offset == 0) { |
| 314 | if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) { |
| 315 | bdrv_dirty_bitmap_deserialize_ones(bitmap, sector, count, |
| 316 | false); |
| 317 | } else { |
| 318 | /* No need to deserialize zeros because the dirty bitmap is |
| 319 | * already cleared */ |
| 320 | } |
| 321 | } else { |
| 322 | ret = bdrv_pread(bs->file, offset, buf, s->cluster_size); |
| 323 | if (ret < 0) { |
| 324 | goto finish; |
| 325 | } |
| 326 | bdrv_dirty_bitmap_deserialize_part(bitmap, buf, sector, count, |
| 327 | false); |
| 328 | } |
| 329 | } |
| 330 | ret = 0; |
| 331 | |
| 332 | bdrv_dirty_bitmap_deserialize_finish(bitmap); |
| 333 | |
| 334 | finish: |
| 335 | g_free(buf); |
| 336 | |
| 337 | return ret; |
| 338 | } |
| 339 | |
| 340 | static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, |
| 341 | Qcow2Bitmap *bm, Error **errp) |
| 342 | { |
| 343 | int ret; |
| 344 | uint64_t *bitmap_table = NULL; |
| 345 | uint32_t granularity; |
| 346 | BdrvDirtyBitmap *bitmap = NULL; |
| 347 | |
| 348 | if (bm->flags & BME_FLAG_IN_USE) { |
| 349 | error_setg(errp, "Bitmap '%s' is in use", bm->name); |
| 350 | goto fail; |
| 351 | } |
| 352 | |
| 353 | ret = bitmap_table_load(bs, &bm->table, &bitmap_table); |
| 354 | if (ret < 0) { |
| 355 | error_setg_errno(errp, -ret, |
| 356 | "Could not read bitmap_table table from image for " |
| 357 | "bitmap '%s'", bm->name); |
| 358 | goto fail; |
| 359 | } |
| 360 | |
| 361 | granularity = 1U << bm->granularity_bits; |
| 362 | bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp); |
| 363 | if (bitmap == NULL) { |
| 364 | goto fail; |
| 365 | } |
| 366 | |
| 367 | ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap); |
| 368 | if (ret < 0) { |
| 369 | error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image", |
| 370 | bm->name); |
| 371 | goto fail; |
| 372 | } |
| 373 | |
| 374 | g_free(bitmap_table); |
| 375 | return bitmap; |
| 376 | |
| 377 | fail: |
| 378 | g_free(bitmap_table); |
| 379 | if (bitmap != NULL) { |
| 380 | bdrv_release_dirty_bitmap(bs, bitmap); |
| 381 | } |
| 382 | |
| 383 | return NULL; |
| 384 | } |
| 385 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 386 | /* |
| 387 | * Bitmap List |
| 388 | */ |
| 389 | |
| 390 | /* |
| 391 | * Bitmap List private functions |
| 392 | * Only Bitmap List knows about bitmap directory structure in Qcow2. |
| 393 | */ |
| 394 | |
| 395 | static inline void bitmap_dir_entry_to_cpu(Qcow2BitmapDirEntry *entry) |
| 396 | { |
| 397 | be64_to_cpus(&entry->bitmap_table_offset); |
| 398 | be32_to_cpus(&entry->bitmap_table_size); |
| 399 | be32_to_cpus(&entry->flags); |
| 400 | be16_to_cpus(&entry->name_size); |
| 401 | be32_to_cpus(&entry->extra_data_size); |
| 402 | } |
| 403 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 404 | static inline void bitmap_dir_entry_to_be(Qcow2BitmapDirEntry *entry) |
| 405 | { |
| 406 | cpu_to_be64s(&entry->bitmap_table_offset); |
| 407 | cpu_to_be32s(&entry->bitmap_table_size); |
| 408 | cpu_to_be32s(&entry->flags); |
| 409 | cpu_to_be16s(&entry->name_size); |
| 410 | cpu_to_be32s(&entry->extra_data_size); |
| 411 | } |
| 412 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 413 | static inline int calc_dir_entry_size(size_t name_size, size_t extra_data_size) |
| 414 | { |
| 415 | return align_offset(sizeof(Qcow2BitmapDirEntry) + |
| 416 | name_size + extra_data_size, 8); |
| 417 | } |
| 418 | |
| 419 | static inline int dir_entry_size(Qcow2BitmapDirEntry *entry) |
| 420 | { |
| 421 | return calc_dir_entry_size(entry->name_size, entry->extra_data_size); |
| 422 | } |
| 423 | |
| 424 | static inline const char *dir_entry_name_field(Qcow2BitmapDirEntry *entry) |
| 425 | { |
| 426 | return (const char *)(entry + 1) + entry->extra_data_size; |
| 427 | } |
| 428 | |
| 429 | static inline char *dir_entry_copy_name(Qcow2BitmapDirEntry *entry) |
| 430 | { |
| 431 | const char *name_field = dir_entry_name_field(entry); |
| 432 | return g_strndup(name_field, entry->name_size); |
| 433 | } |
| 434 | |
| 435 | static inline Qcow2BitmapDirEntry *next_dir_entry(Qcow2BitmapDirEntry *entry) |
| 436 | { |
| 437 | return (Qcow2BitmapDirEntry *)((uint8_t *)entry + dir_entry_size(entry)); |
| 438 | } |
| 439 | |
| 440 | static int check_dir_entry(BlockDriverState *bs, Qcow2BitmapDirEntry *entry) |
| 441 | { |
| 442 | BDRVQcow2State *s = bs->opaque; |
| 443 | uint64_t phys_bitmap_bytes; |
| 444 | int64_t len; |
| 445 | |
| 446 | bool fail = (entry->bitmap_table_size == 0) || |
| 447 | (entry->bitmap_table_offset == 0) || |
| 448 | (entry->bitmap_table_offset % s->cluster_size) || |
| 449 | (entry->bitmap_table_size > BME_MAX_TABLE_SIZE) || |
| 450 | (entry->granularity_bits > BME_MAX_GRANULARITY_BITS) || |
| 451 | (entry->granularity_bits < BME_MIN_GRANULARITY_BITS) || |
| 452 | (entry->flags & BME_RESERVED_FLAGS) || |
| 453 | (entry->name_size > BME_MAX_NAME_SIZE) || |
| 454 | (entry->type != BT_DIRTY_TRACKING_BITMAP); |
| 455 | |
| 456 | if (fail) { |
| 457 | return -EINVAL; |
| 458 | } |
| 459 | |
| 460 | phys_bitmap_bytes = (uint64_t)entry->bitmap_table_size * s->cluster_size; |
| 461 | len = bdrv_getlength(bs); |
| 462 | |
| 463 | if (len < 0) { |
| 464 | return len; |
| 465 | } |
| 466 | |
| 467 | fail = (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) || |
| 468 | (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)); |
| 469 | |
| 470 | return fail ? -EINVAL : 0; |
| 471 | } |
| 472 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 473 | static inline void bitmap_directory_to_be(uint8_t *dir, size_t size) |
| 474 | { |
| 475 | uint8_t *end = dir + size; |
| 476 | while (dir < end) { |
| 477 | Qcow2BitmapDirEntry *e = (Qcow2BitmapDirEntry *)dir; |
| 478 | dir += dir_entry_size(e); |
| 479 | |
| 480 | bitmap_dir_entry_to_be(e); |
| 481 | } |
| 482 | } |
| 483 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 484 | /* |
| 485 | * Bitmap List public functions |
| 486 | */ |
| 487 | |
| 488 | static void bitmap_free(Qcow2Bitmap *bm) |
| 489 | { |
| 490 | g_free(bm->name); |
| 491 | g_free(bm); |
| 492 | } |
| 493 | |
| 494 | static void bitmap_list_free(Qcow2BitmapList *bm_list) |
| 495 | { |
| 496 | Qcow2Bitmap *bm; |
| 497 | |
| 498 | if (bm_list == NULL) { |
| 499 | return; |
| 500 | } |
| 501 | |
| 502 | while ((bm = QSIMPLEQ_FIRST(bm_list)) != NULL) { |
| 503 | QSIMPLEQ_REMOVE_HEAD(bm_list, entry); |
| 504 | bitmap_free(bm); |
| 505 | } |
| 506 | |
| 507 | g_free(bm_list); |
| 508 | } |
| 509 | |
| 510 | static Qcow2BitmapList *bitmap_list_new(void) |
| 511 | { |
| 512 | Qcow2BitmapList *bm_list = g_new(Qcow2BitmapList, 1); |
| 513 | QSIMPLEQ_INIT(bm_list); |
| 514 | |
| 515 | return bm_list; |
| 516 | } |
| 517 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 518 | static uint32_t bitmap_list_count(Qcow2BitmapList *bm_list) |
| 519 | { |
| 520 | Qcow2Bitmap *bm; |
| 521 | uint32_t nb_bitmaps = 0; |
| 522 | |
| 523 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 524 | nb_bitmaps++; |
| 525 | } |
| 526 | |
| 527 | return nb_bitmaps; |
| 528 | } |
| 529 | |
Vladimir Sementsov-Ogievskiy | 88ddffa | 2017-06-28 15:05:08 +0300 | [diff] [blame] | 530 | /* bitmap_list_load |
| 531 | * Get bitmap list from qcow2 image. Actually reads bitmap directory, |
| 532 | * checks it and convert to bitmap list. |
| 533 | */ |
| 534 | static Qcow2BitmapList *bitmap_list_load(BlockDriverState *bs, uint64_t offset, |
| 535 | uint64_t size, Error **errp) |
| 536 | { |
| 537 | int ret; |
| 538 | BDRVQcow2State *s = bs->opaque; |
| 539 | uint8_t *dir, *dir_end; |
| 540 | Qcow2BitmapDirEntry *e; |
| 541 | uint32_t nb_dir_entries = 0; |
| 542 | Qcow2BitmapList *bm_list = NULL; |
| 543 | |
| 544 | if (size == 0) { |
| 545 | error_setg(errp, "Requested bitmap directory size is zero"); |
| 546 | return NULL; |
| 547 | } |
| 548 | |
| 549 | if (size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
| 550 | error_setg(errp, "Requested bitmap directory size is too big"); |
| 551 | return NULL; |
| 552 | } |
| 553 | |
| 554 | dir = g_try_malloc(size); |
| 555 | if (dir == NULL) { |
| 556 | error_setg(errp, "Failed to allocate space for bitmap directory"); |
| 557 | return NULL; |
| 558 | } |
| 559 | dir_end = dir + size; |
| 560 | |
| 561 | ret = bdrv_pread(bs->file, offset, dir, size); |
| 562 | if (ret < 0) { |
| 563 | error_setg_errno(errp, -ret, "Failed to read bitmap directory"); |
| 564 | goto fail; |
| 565 | } |
| 566 | |
| 567 | bm_list = bitmap_list_new(); |
| 568 | for (e = (Qcow2BitmapDirEntry *)dir; |
| 569 | e < (Qcow2BitmapDirEntry *)dir_end; |
| 570 | e = next_dir_entry(e)) |
| 571 | { |
| 572 | Qcow2Bitmap *bm; |
| 573 | |
| 574 | if ((uint8_t *)(e + 1) > dir_end) { |
| 575 | goto broken_dir; |
| 576 | } |
| 577 | |
| 578 | if (++nb_dir_entries > s->nb_bitmaps) { |
| 579 | error_setg(errp, "More bitmaps found than specified in header" |
| 580 | " extension"); |
| 581 | goto fail; |
| 582 | } |
| 583 | bitmap_dir_entry_to_cpu(e); |
| 584 | |
| 585 | if ((uint8_t *)next_dir_entry(e) > dir_end) { |
| 586 | goto broken_dir; |
| 587 | } |
| 588 | |
| 589 | if (e->extra_data_size != 0) { |
| 590 | error_setg(errp, "Bitmap extra data is not supported"); |
| 591 | goto fail; |
| 592 | } |
| 593 | |
| 594 | ret = check_dir_entry(bs, e); |
| 595 | if (ret < 0) { |
| 596 | error_setg(errp, "Bitmap '%.*s' doesn't satisfy the constraints", |
| 597 | e->name_size, dir_entry_name_field(e)); |
| 598 | goto fail; |
| 599 | } |
| 600 | |
| 601 | bm = g_new(Qcow2Bitmap, 1); |
| 602 | bm->table.offset = e->bitmap_table_offset; |
| 603 | bm->table.size = e->bitmap_table_size; |
| 604 | bm->flags = e->flags; |
| 605 | bm->granularity_bits = e->granularity_bits; |
| 606 | bm->name = dir_entry_copy_name(e); |
| 607 | QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); |
| 608 | } |
| 609 | |
| 610 | if (nb_dir_entries != s->nb_bitmaps) { |
| 611 | error_setg(errp, "Less bitmaps found than specified in header" |
| 612 | " extension"); |
| 613 | goto fail; |
| 614 | } |
| 615 | |
| 616 | if ((uint8_t *)e != dir_end) { |
| 617 | goto broken_dir; |
| 618 | } |
| 619 | |
| 620 | g_free(dir); |
| 621 | return bm_list; |
| 622 | |
| 623 | broken_dir: |
| 624 | ret = -EINVAL; |
| 625 | error_setg(errp, "Broken bitmap directory"); |
| 626 | |
| 627 | fail: |
| 628 | g_free(dir); |
| 629 | bitmap_list_free(bm_list); |
| 630 | |
| 631 | return NULL; |
| 632 | } |
| 633 | |
| 634 | int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, |
| 635 | void **refcount_table, |
| 636 | int64_t *refcount_table_size) |
| 637 | { |
| 638 | int ret; |
| 639 | BDRVQcow2State *s = bs->opaque; |
| 640 | Qcow2BitmapList *bm_list; |
| 641 | Qcow2Bitmap *bm; |
| 642 | |
| 643 | if (s->nb_bitmaps == 0) { |
| 644 | return 0; |
| 645 | } |
| 646 | |
| 647 | ret = qcow2_inc_refcounts_imrt(bs, res, refcount_table, refcount_table_size, |
| 648 | s->bitmap_directory_offset, |
| 649 | s->bitmap_directory_size); |
| 650 | if (ret < 0) { |
| 651 | return ret; |
| 652 | } |
| 653 | |
| 654 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 655 | s->bitmap_directory_size, NULL); |
| 656 | if (bm_list == NULL) { |
| 657 | res->corruptions++; |
| 658 | return -EINVAL; |
| 659 | } |
| 660 | |
| 661 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 662 | uint64_t *bitmap_table = NULL; |
| 663 | int i; |
| 664 | |
| 665 | ret = qcow2_inc_refcounts_imrt(bs, res, |
| 666 | refcount_table, refcount_table_size, |
| 667 | bm->table.offset, |
| 668 | bm->table.size * sizeof(uint64_t)); |
| 669 | if (ret < 0) { |
| 670 | goto out; |
| 671 | } |
| 672 | |
| 673 | ret = bitmap_table_load(bs, &bm->table, &bitmap_table); |
| 674 | if (ret < 0) { |
| 675 | res->corruptions++; |
| 676 | goto out; |
| 677 | } |
| 678 | |
| 679 | for (i = 0; i < bm->table.size; ++i) { |
| 680 | uint64_t entry = bitmap_table[i]; |
| 681 | uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK; |
| 682 | |
| 683 | if (check_table_entry(entry, s->cluster_size) < 0) { |
| 684 | res->corruptions++; |
| 685 | continue; |
| 686 | } |
| 687 | |
| 688 | if (offset == 0) { |
| 689 | continue; |
| 690 | } |
| 691 | |
| 692 | ret = qcow2_inc_refcounts_imrt(bs, res, |
| 693 | refcount_table, refcount_table_size, |
| 694 | offset, s->cluster_size); |
| 695 | if (ret < 0) { |
| 696 | g_free(bitmap_table); |
| 697 | goto out; |
| 698 | } |
| 699 | } |
| 700 | |
| 701 | g_free(bitmap_table); |
| 702 | } |
| 703 | |
| 704 | out: |
| 705 | bitmap_list_free(bm_list); |
| 706 | |
| 707 | return ret; |
| 708 | } |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 709 | |
| 710 | /* bitmap_list_store |
| 711 | * Store bitmap list to qcow2 image as a bitmap directory. |
| 712 | * Everything is checked. |
| 713 | */ |
| 714 | static int bitmap_list_store(BlockDriverState *bs, Qcow2BitmapList *bm_list, |
| 715 | uint64_t *offset, uint64_t *size, bool in_place) |
| 716 | { |
| 717 | int ret; |
| 718 | uint8_t *dir; |
| 719 | int64_t dir_offset = 0; |
| 720 | uint64_t dir_size = 0; |
| 721 | Qcow2Bitmap *bm; |
| 722 | Qcow2BitmapDirEntry *e; |
| 723 | |
| 724 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 725 | dir_size += calc_dir_entry_size(strlen(bm->name), 0); |
| 726 | } |
| 727 | |
| 728 | if (dir_size == 0 || dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
| 729 | return -EINVAL; |
| 730 | } |
| 731 | |
| 732 | if (in_place) { |
| 733 | if (*size != dir_size || *offset == 0) { |
| 734 | return -EINVAL; |
| 735 | } |
| 736 | |
| 737 | dir_offset = *offset; |
| 738 | } |
| 739 | |
| 740 | dir = g_try_malloc(dir_size); |
| 741 | if (dir == NULL) { |
| 742 | return -ENOMEM; |
| 743 | } |
| 744 | |
| 745 | e = (Qcow2BitmapDirEntry *)dir; |
| 746 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 747 | e->bitmap_table_offset = bm->table.offset; |
| 748 | e->bitmap_table_size = bm->table.size; |
| 749 | e->flags = bm->flags; |
| 750 | e->type = BT_DIRTY_TRACKING_BITMAP; |
| 751 | e->granularity_bits = bm->granularity_bits; |
| 752 | e->name_size = strlen(bm->name); |
| 753 | e->extra_data_size = 0; |
| 754 | memcpy(e + 1, bm->name, e->name_size); |
| 755 | |
| 756 | if (check_dir_entry(bs, e) < 0) { |
| 757 | ret = -EINVAL; |
| 758 | goto fail; |
| 759 | } |
| 760 | |
| 761 | e = next_dir_entry(e); |
| 762 | } |
| 763 | |
| 764 | bitmap_directory_to_be(dir, dir_size); |
| 765 | |
| 766 | if (!in_place) { |
| 767 | dir_offset = qcow2_alloc_clusters(bs, dir_size); |
| 768 | if (dir_offset < 0) { |
| 769 | ret = dir_offset; |
| 770 | goto fail; |
| 771 | } |
| 772 | } |
| 773 | |
| 774 | ret = qcow2_pre_write_overlap_check(bs, 0, dir_offset, dir_size); |
| 775 | if (ret < 0) { |
| 776 | goto fail; |
| 777 | } |
| 778 | |
| 779 | ret = bdrv_pwrite(bs->file, dir_offset, dir, dir_size); |
| 780 | if (ret < 0) { |
| 781 | goto fail; |
| 782 | } |
| 783 | |
| 784 | g_free(dir); |
| 785 | |
| 786 | if (!in_place) { |
| 787 | *size = dir_size; |
| 788 | *offset = dir_offset; |
| 789 | } |
| 790 | |
| 791 | return 0; |
| 792 | |
| 793 | fail: |
| 794 | g_free(dir); |
| 795 | |
| 796 | if (!in_place && dir_offset > 0) { |
| 797 | qcow2_free_clusters(bs, dir_offset, dir_size, QCOW2_DISCARD_OTHER); |
| 798 | } |
| 799 | |
| 800 | return ret; |
| 801 | } |
| 802 | |
| 803 | /* |
| 804 | * Bitmap List end |
| 805 | */ |
| 806 | |
| 807 | static int update_ext_header_and_dir_in_place(BlockDriverState *bs, |
| 808 | Qcow2BitmapList *bm_list) |
| 809 | { |
| 810 | BDRVQcow2State *s = bs->opaque; |
| 811 | int ret; |
| 812 | |
| 813 | if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS) || |
| 814 | bm_list == NULL || QSIMPLEQ_EMPTY(bm_list) || |
| 815 | bitmap_list_count(bm_list) != s->nb_bitmaps) |
| 816 | { |
| 817 | return -EINVAL; |
| 818 | } |
| 819 | |
| 820 | s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; |
| 821 | ret = update_header_sync(bs); |
| 822 | if (ret < 0) { |
| 823 | /* Two variants are possible here: |
| 824 | * 1. Autoclear flag is dropped, all bitmaps will be lost. |
| 825 | * 2. Autoclear flag is not dropped, old state is left. |
| 826 | */ |
| 827 | return ret; |
| 828 | } |
| 829 | |
| 830 | /* autoclear bit is not set, so we can safely update bitmap directory */ |
| 831 | |
| 832 | ret = bitmap_list_store(bs, bm_list, &s->bitmap_directory_offset, |
| 833 | &s->bitmap_directory_size, true); |
| 834 | if (ret < 0) { |
| 835 | /* autoclear bit is cleared, so all leaked clusters would be removed on |
| 836 | * qemu-img check */ |
| 837 | return ret; |
| 838 | } |
| 839 | |
| 840 | ret = update_header_sync(bs); |
| 841 | if (ret < 0) { |
| 842 | /* autoclear bit is cleared, so all leaked clusters would be removed on |
| 843 | * qemu-img check */ |
| 844 | return ret; |
| 845 | } |
| 846 | |
| 847 | s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS; |
| 848 | return update_header_sync(bs); |
| 849 | /* If final update_header_sync() fails, two variants are possible: |
| 850 | * 1. Autoclear flag is not set, all bitmaps will be lost. |
| 851 | * 2. Autoclear flag is set, header and directory are successfully updated. |
| 852 | */ |
| 853 | } |
| 854 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 855 | static int update_ext_header_and_dir(BlockDriverState *bs, |
| 856 | Qcow2BitmapList *bm_list) |
| 857 | { |
| 858 | BDRVQcow2State *s = bs->opaque; |
| 859 | int ret; |
| 860 | uint64_t new_offset = 0; |
| 861 | uint64_t new_size = 0; |
| 862 | uint32_t new_nb_bitmaps = 0; |
| 863 | uint64_t old_offset = s->bitmap_directory_offset; |
| 864 | uint64_t old_size = s->bitmap_directory_size; |
| 865 | uint32_t old_nb_bitmaps = s->nb_bitmaps; |
| 866 | uint64_t old_autocl = s->autoclear_features; |
| 867 | |
| 868 | if (bm_list != NULL && !QSIMPLEQ_EMPTY(bm_list)) { |
| 869 | new_nb_bitmaps = bitmap_list_count(bm_list); |
| 870 | |
| 871 | if (new_nb_bitmaps > QCOW2_MAX_BITMAPS) { |
| 872 | return -EINVAL; |
| 873 | } |
| 874 | |
| 875 | ret = bitmap_list_store(bs, bm_list, &new_offset, &new_size, false); |
| 876 | if (ret < 0) { |
| 877 | return ret; |
| 878 | } |
| 879 | |
| 880 | ret = bdrv_flush(bs->file->bs); |
| 881 | if (ret < 0) { |
| 882 | goto fail; |
| 883 | } |
| 884 | |
| 885 | s->autoclear_features |= QCOW2_AUTOCLEAR_BITMAPS; |
| 886 | } else { |
| 887 | s->autoclear_features &= ~(uint64_t)QCOW2_AUTOCLEAR_BITMAPS; |
| 888 | } |
| 889 | |
| 890 | s->bitmap_directory_offset = new_offset; |
| 891 | s->bitmap_directory_size = new_size; |
| 892 | s->nb_bitmaps = new_nb_bitmaps; |
| 893 | |
| 894 | ret = update_header_sync(bs); |
| 895 | if (ret < 0) { |
| 896 | goto fail; |
| 897 | } |
| 898 | |
| 899 | if (old_size > 0) { |
| 900 | qcow2_free_clusters(bs, old_offset, old_size, QCOW2_DISCARD_OTHER); |
| 901 | } |
| 902 | |
| 903 | return 0; |
| 904 | |
| 905 | fail: |
| 906 | if (new_offset > 0) { |
| 907 | qcow2_free_clusters(bs, new_offset, new_size, QCOW2_DISCARD_OTHER); |
| 908 | } |
| 909 | |
| 910 | s->bitmap_directory_offset = old_offset; |
| 911 | s->bitmap_directory_size = old_size; |
| 912 | s->nb_bitmaps = old_nb_bitmaps; |
| 913 | s->autoclear_features = old_autocl; |
| 914 | |
| 915 | return ret; |
| 916 | } |
| 917 | |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 918 | /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ |
| 919 | static void release_dirty_bitmap_helper(gpointer bitmap, |
| 920 | gpointer bs) |
| 921 | { |
| 922 | bdrv_release_dirty_bitmap(bs, bitmap); |
| 923 | } |
| 924 | |
| 925 | /* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */ |
| 926 | static void set_readonly_helper(gpointer bitmap, gpointer value) |
| 927 | { |
| 928 | bdrv_dirty_bitmap_set_readonly(bitmap, (bool)value); |
| 929 | } |
| 930 | |
| 931 | /* qcow2_load_autoloading_dirty_bitmaps() |
| 932 | * Return value is a hint for caller: true means that the Qcow2 header was |
| 933 | * updated. (false doesn't mean that the header should be updated by the |
| 934 | * caller, it just means that updating was not needed or the image cannot be |
| 935 | * written to). |
| 936 | * On failure the function returns false. |
| 937 | */ |
| 938 | bool qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp) |
| 939 | { |
| 940 | BDRVQcow2State *s = bs->opaque; |
| 941 | Qcow2BitmapList *bm_list; |
| 942 | Qcow2Bitmap *bm; |
| 943 | GSList *created_dirty_bitmaps = NULL; |
| 944 | bool header_updated = false; |
| 945 | |
| 946 | if (s->nb_bitmaps == 0) { |
| 947 | /* No bitmaps - nothing to do */ |
| 948 | return false; |
| 949 | } |
| 950 | |
| 951 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 952 | s->bitmap_directory_size, errp); |
| 953 | if (bm_list == NULL) { |
| 954 | return false; |
| 955 | } |
| 956 | |
| 957 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 958 | if ((bm->flags & BME_FLAG_AUTO) && !(bm->flags & BME_FLAG_IN_USE)) { |
| 959 | BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); |
| 960 | if (bitmap == NULL) { |
| 961 | goto fail; |
| 962 | } |
Vladimir Sementsov-Ogievskiy | a0319aa | 2017-06-28 15:05:15 +0300 | [diff] [blame] | 963 | |
Vladimir Sementsov-Ogievskiy | a88b179 | 2017-06-28 15:05:17 +0300 | [diff] [blame] | 964 | bdrv_dirty_bitmap_set_persistance(bitmap, true); |
Vladimir Sementsov-Ogievskiy | a0319aa | 2017-06-28 15:05:15 +0300 | [diff] [blame] | 965 | bdrv_dirty_bitmap_set_autoload(bitmap, true); |
Vladimir Sementsov-Ogievskiy | d1258dd | 2017-06-28 15:05:11 +0300 | [diff] [blame] | 966 | bm->flags |= BME_FLAG_IN_USE; |
| 967 | created_dirty_bitmaps = |
| 968 | g_slist_append(created_dirty_bitmaps, bitmap); |
| 969 | } |
| 970 | } |
| 971 | |
| 972 | if (created_dirty_bitmaps != NULL) { |
| 973 | if (can_write(bs)) { |
| 974 | /* in_use flags must be updated */ |
| 975 | int ret = update_ext_header_and_dir_in_place(bs, bm_list); |
| 976 | if (ret < 0) { |
| 977 | error_setg_errno(errp, -ret, "Can't update bitmap directory"); |
| 978 | goto fail; |
| 979 | } |
| 980 | header_updated = true; |
| 981 | } else { |
| 982 | g_slist_foreach(created_dirty_bitmaps, set_readonly_helper, |
| 983 | (gpointer)true); |
| 984 | } |
| 985 | } |
| 986 | |
| 987 | g_slist_free(created_dirty_bitmaps); |
| 988 | bitmap_list_free(bm_list); |
| 989 | |
| 990 | return header_updated; |
| 991 | |
| 992 | fail: |
| 993 | g_slist_foreach(created_dirty_bitmaps, release_dirty_bitmap_helper, bs); |
| 994 | g_slist_free(created_dirty_bitmaps); |
| 995 | bitmap_list_free(bm_list); |
| 996 | |
| 997 | return false; |
| 998 | } |
Vladimir Sementsov-Ogievskiy | 1b6b056 | 2017-06-28 15:05:14 +0300 | [diff] [blame] | 999 | |
| 1000 | int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp) |
| 1001 | { |
| 1002 | BDRVQcow2State *s = bs->opaque; |
| 1003 | Qcow2BitmapList *bm_list; |
| 1004 | Qcow2Bitmap *bm; |
| 1005 | GSList *ro_dirty_bitmaps = NULL; |
| 1006 | int ret = 0; |
| 1007 | |
| 1008 | if (s->nb_bitmaps == 0) { |
| 1009 | /* No bitmaps - nothing to do */ |
| 1010 | return 0; |
| 1011 | } |
| 1012 | |
| 1013 | if (!can_write(bs)) { |
| 1014 | error_setg(errp, "Can't write to the image on reopening bitmaps rw"); |
| 1015 | return -EINVAL; |
| 1016 | } |
| 1017 | |
| 1018 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 1019 | s->bitmap_directory_size, errp); |
| 1020 | if (bm_list == NULL) { |
| 1021 | return -EINVAL; |
| 1022 | } |
| 1023 | |
| 1024 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 1025 | if (!(bm->flags & BME_FLAG_IN_USE)) { |
| 1026 | BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); |
| 1027 | if (bitmap == NULL) { |
| 1028 | continue; |
| 1029 | } |
| 1030 | |
| 1031 | if (!bdrv_dirty_bitmap_readonly(bitmap)) { |
| 1032 | error_setg(errp, "Bitmap %s is not readonly but not marked" |
| 1033 | "'IN_USE' in the image. Something went wrong," |
| 1034 | "all the bitmaps may be corrupted", bm->name); |
| 1035 | ret = -EINVAL; |
| 1036 | goto out; |
| 1037 | } |
| 1038 | |
| 1039 | bm->flags |= BME_FLAG_IN_USE; |
| 1040 | ro_dirty_bitmaps = g_slist_append(ro_dirty_bitmaps, bitmap); |
| 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | if (ro_dirty_bitmaps != NULL) { |
| 1045 | /* in_use flags must be updated */ |
| 1046 | ret = update_ext_header_and_dir_in_place(bs, bm_list); |
| 1047 | if (ret < 0) { |
| 1048 | error_setg_errno(errp, -ret, "Can't update bitmap directory"); |
| 1049 | goto out; |
| 1050 | } |
| 1051 | g_slist_foreach(ro_dirty_bitmaps, set_readonly_helper, false); |
| 1052 | } |
| 1053 | |
| 1054 | out: |
| 1055 | g_slist_free(ro_dirty_bitmaps); |
| 1056 | bitmap_list_free(bm_list); |
| 1057 | |
| 1058 | return ret; |
| 1059 | } |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 1060 | |
| 1061 | /* store_bitmap_data() |
| 1062 | * Store bitmap to image, filling bitmap table accordingly. |
| 1063 | */ |
| 1064 | static uint64_t *store_bitmap_data(BlockDriverState *bs, |
| 1065 | BdrvDirtyBitmap *bitmap, |
| 1066 | uint32_t *bitmap_table_size, Error **errp) |
| 1067 | { |
| 1068 | int ret; |
| 1069 | BDRVQcow2State *s = bs->opaque; |
| 1070 | int64_t sector; |
| 1071 | uint64_t sbc; |
| 1072 | uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); |
| 1073 | const char *bm_name = bdrv_dirty_bitmap_name(bitmap); |
| 1074 | uint8_t *buf = NULL; |
| 1075 | BdrvDirtyBitmapIter *dbi; |
| 1076 | uint64_t *tb; |
| 1077 | uint64_t tb_size = |
| 1078 | size_to_clusters(s, |
| 1079 | bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size)); |
| 1080 | |
| 1081 | if (tb_size > BME_MAX_TABLE_SIZE || |
| 1082 | tb_size * s->cluster_size > BME_MAX_PHYS_SIZE) |
| 1083 | { |
| 1084 | error_setg(errp, "Bitmap '%s' is too big", bm_name); |
| 1085 | return NULL; |
| 1086 | } |
| 1087 | |
| 1088 | tb = g_try_new0(uint64_t, tb_size); |
| 1089 | if (tb == NULL) { |
| 1090 | error_setg(errp, "No memory"); |
| 1091 | return NULL; |
| 1092 | } |
| 1093 | |
| 1094 | dbi = bdrv_dirty_iter_new(bitmap, 0); |
| 1095 | buf = g_malloc(s->cluster_size); |
| 1096 | sbc = sectors_covered_by_bitmap_cluster(s, bitmap); |
| 1097 | assert(DIV_ROUND_UP(bm_size, sbc) == tb_size); |
| 1098 | |
| 1099 | while ((sector = bdrv_dirty_iter_next(dbi)) != -1) { |
| 1100 | uint64_t cluster = sector / sbc; |
| 1101 | uint64_t end, write_size; |
| 1102 | int64_t off; |
| 1103 | |
| 1104 | sector = cluster * sbc; |
| 1105 | end = MIN(bm_size, sector + sbc); |
| 1106 | write_size = |
| 1107 | bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector); |
| 1108 | assert(write_size <= s->cluster_size); |
| 1109 | |
| 1110 | off = qcow2_alloc_clusters(bs, s->cluster_size); |
| 1111 | if (off < 0) { |
| 1112 | error_setg_errno(errp, -off, |
| 1113 | "Failed to allocate clusters for bitmap '%s'", |
| 1114 | bm_name); |
| 1115 | goto fail; |
| 1116 | } |
| 1117 | tb[cluster] = off; |
| 1118 | |
| 1119 | bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end - sector); |
| 1120 | if (write_size < s->cluster_size) { |
| 1121 | memset(buf + write_size, 0, s->cluster_size - write_size); |
| 1122 | } |
| 1123 | |
| 1124 | ret = qcow2_pre_write_overlap_check(bs, 0, off, s->cluster_size); |
| 1125 | if (ret < 0) { |
| 1126 | error_setg_errno(errp, -ret, "Qcow2 overlap check failed"); |
| 1127 | goto fail; |
| 1128 | } |
| 1129 | |
| 1130 | ret = bdrv_pwrite(bs->file, off, buf, s->cluster_size); |
| 1131 | if (ret < 0) { |
| 1132 | error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file", |
| 1133 | bm_name); |
| 1134 | goto fail; |
| 1135 | } |
| 1136 | |
| 1137 | if (end >= bm_size) { |
| 1138 | break; |
| 1139 | } |
| 1140 | |
| 1141 | bdrv_set_dirty_iter(dbi, end); |
| 1142 | } |
| 1143 | |
| 1144 | *bitmap_table_size = tb_size; |
| 1145 | g_free(buf); |
| 1146 | bdrv_dirty_iter_free(dbi); |
| 1147 | |
| 1148 | return tb; |
| 1149 | |
| 1150 | fail: |
| 1151 | clear_bitmap_table(bs, tb, tb_size); |
| 1152 | g_free(buf); |
| 1153 | bdrv_dirty_iter_free(dbi); |
| 1154 | g_free(tb); |
| 1155 | |
| 1156 | return NULL; |
| 1157 | } |
| 1158 | |
| 1159 | /* store_bitmap() |
| 1160 | * Store bm->dirty_bitmap to qcow2. |
| 1161 | * Set bm->table_offset and bm->table_size accordingly. |
| 1162 | */ |
| 1163 | static int store_bitmap(BlockDriverState *bs, Qcow2Bitmap *bm, Error **errp) |
| 1164 | { |
| 1165 | int ret; |
| 1166 | uint64_t *tb; |
| 1167 | int64_t tb_offset; |
| 1168 | uint32_t tb_size; |
| 1169 | BdrvDirtyBitmap *bitmap = bm->dirty_bitmap; |
| 1170 | const char *bm_name; |
| 1171 | |
| 1172 | assert(bitmap != NULL); |
| 1173 | |
| 1174 | bm_name = bdrv_dirty_bitmap_name(bitmap); |
| 1175 | |
| 1176 | tb = store_bitmap_data(bs, bitmap, &tb_size, errp); |
| 1177 | if (tb == NULL) { |
| 1178 | return -EINVAL; |
| 1179 | } |
| 1180 | |
| 1181 | assert(tb_size <= BME_MAX_TABLE_SIZE); |
| 1182 | tb_offset = qcow2_alloc_clusters(bs, tb_size * sizeof(tb[0])); |
| 1183 | if (tb_offset < 0) { |
| 1184 | error_setg_errno(errp, -tb_offset, |
| 1185 | "Failed to allocate clusters for bitmap '%s'", |
| 1186 | bm_name); |
| 1187 | ret = tb_offset; |
| 1188 | goto fail; |
| 1189 | } |
| 1190 | |
| 1191 | ret = qcow2_pre_write_overlap_check(bs, 0, tb_offset, |
| 1192 | tb_size * sizeof(tb[0])); |
| 1193 | if (ret < 0) { |
| 1194 | error_setg_errno(errp, -ret, "Qcow2 overlap check failed"); |
| 1195 | goto fail; |
| 1196 | } |
| 1197 | |
| 1198 | bitmap_table_to_be(tb, tb_size); |
| 1199 | ret = bdrv_pwrite(bs->file, tb_offset, tb, tb_size * sizeof(tb[0])); |
| 1200 | if (ret < 0) { |
| 1201 | error_setg_errno(errp, -ret, "Failed to write bitmap '%s' to file", |
| 1202 | bm_name); |
| 1203 | goto fail; |
| 1204 | } |
| 1205 | |
| 1206 | g_free(tb); |
| 1207 | |
| 1208 | bm->table.offset = tb_offset; |
| 1209 | bm->table.size = tb_size; |
| 1210 | |
| 1211 | return 0; |
| 1212 | |
| 1213 | fail: |
| 1214 | clear_bitmap_table(bs, tb, tb_size); |
| 1215 | |
| 1216 | if (tb_offset > 0) { |
| 1217 | qcow2_free_clusters(bs, tb_offset, tb_size * sizeof(tb[0]), |
| 1218 | QCOW2_DISCARD_OTHER); |
| 1219 | } |
| 1220 | |
| 1221 | g_free(tb); |
| 1222 | |
| 1223 | return ret; |
| 1224 | } |
| 1225 | |
| 1226 | static Qcow2Bitmap *find_bitmap_by_name(Qcow2BitmapList *bm_list, |
| 1227 | const char *name) |
| 1228 | { |
| 1229 | Qcow2Bitmap *bm; |
| 1230 | |
| 1231 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 1232 | if (strcmp(name, bm->name) == 0) { |
| 1233 | return bm; |
| 1234 | } |
| 1235 | } |
| 1236 | |
| 1237 | return NULL; |
| 1238 | } |
| 1239 | |
Vladimir Sementsov-Ogievskiy | 469c71e | 2017-06-28 15:05:28 +0300 | [diff] [blame] | 1240 | void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs, |
| 1241 | const char *name, |
| 1242 | Error **errp) |
| 1243 | { |
| 1244 | int ret; |
| 1245 | BDRVQcow2State *s = bs->opaque; |
| 1246 | Qcow2Bitmap *bm; |
| 1247 | Qcow2BitmapList *bm_list; |
| 1248 | |
| 1249 | if (s->nb_bitmaps == 0) { |
| 1250 | /* Absence of the bitmap is not an error: see explanation above |
| 1251 | * bdrv_remove_persistent_dirty_bitmap() definition. */ |
| 1252 | return; |
| 1253 | } |
| 1254 | |
| 1255 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 1256 | s->bitmap_directory_size, errp); |
| 1257 | if (bm_list == NULL) { |
| 1258 | return; |
| 1259 | } |
| 1260 | |
| 1261 | bm = find_bitmap_by_name(bm_list, name); |
| 1262 | if (bm == NULL) { |
| 1263 | goto fail; |
| 1264 | } |
| 1265 | |
| 1266 | QSIMPLEQ_REMOVE(bm_list, bm, Qcow2Bitmap, entry); |
| 1267 | |
| 1268 | ret = update_ext_header_and_dir(bs, bm_list); |
| 1269 | if (ret < 0) { |
| 1270 | error_setg_errno(errp, -ret, "Failed to update bitmap extension"); |
| 1271 | goto fail; |
| 1272 | } |
| 1273 | |
| 1274 | free_bitmap_clusters(bs, &bm->table); |
| 1275 | |
| 1276 | fail: |
| 1277 | bitmap_free(bm); |
| 1278 | bitmap_list_free(bm_list); |
| 1279 | } |
| 1280 | |
Vladimir Sementsov-Ogievskiy | 5f72826 | 2017-06-28 15:05:19 +0300 | [diff] [blame] | 1281 | void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp) |
| 1282 | { |
| 1283 | BdrvDirtyBitmap *bitmap; |
| 1284 | BDRVQcow2State *s = bs->opaque; |
| 1285 | uint32_t new_nb_bitmaps = s->nb_bitmaps; |
| 1286 | uint64_t new_dir_size = s->bitmap_directory_size; |
| 1287 | int ret; |
| 1288 | Qcow2BitmapList *bm_list; |
| 1289 | Qcow2Bitmap *bm; |
| 1290 | Qcow2BitmapTableList drop_tables; |
| 1291 | Qcow2BitmapTable *tb, *tb_next; |
| 1292 | |
| 1293 | if (!bdrv_has_changed_persistent_bitmaps(bs)) { |
| 1294 | /* nothing to do */ |
| 1295 | return; |
| 1296 | } |
| 1297 | |
| 1298 | if (!can_write(bs)) { |
| 1299 | error_setg(errp, "No write access"); |
| 1300 | return; |
| 1301 | } |
| 1302 | |
| 1303 | QSIMPLEQ_INIT(&drop_tables); |
| 1304 | |
| 1305 | if (s->nb_bitmaps == 0) { |
| 1306 | bm_list = bitmap_list_new(); |
| 1307 | } else { |
| 1308 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 1309 | s->bitmap_directory_size, errp); |
| 1310 | if (bm_list == NULL) { |
| 1311 | return; |
| 1312 | } |
| 1313 | } |
| 1314 | |
| 1315 | /* check constraints and names */ |
| 1316 | for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; |
| 1317 | bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) |
| 1318 | { |
| 1319 | const char *name = bdrv_dirty_bitmap_name(bitmap); |
| 1320 | uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap); |
| 1321 | Qcow2Bitmap *bm; |
| 1322 | |
| 1323 | if (!bdrv_dirty_bitmap_get_persistance(bitmap) || |
| 1324 | bdrv_dirty_bitmap_readonly(bitmap)) |
| 1325 | { |
| 1326 | continue; |
| 1327 | } |
| 1328 | |
| 1329 | if (check_constraints_on_bitmap(bs, name, granularity, errp) < 0) { |
| 1330 | error_prepend(errp, "Bitmap '%s' doesn't satisfy the constraints: ", |
| 1331 | name); |
| 1332 | goto fail; |
| 1333 | } |
| 1334 | |
| 1335 | bm = find_bitmap_by_name(bm_list, name); |
| 1336 | if (bm == NULL) { |
| 1337 | if (++new_nb_bitmaps > QCOW2_MAX_BITMAPS) { |
| 1338 | error_setg(errp, "Too many persistent bitmaps"); |
| 1339 | goto fail; |
| 1340 | } |
| 1341 | |
| 1342 | new_dir_size += calc_dir_entry_size(strlen(name), 0); |
| 1343 | if (new_dir_size > QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
| 1344 | error_setg(errp, "Bitmap directory is too large"); |
| 1345 | goto fail; |
| 1346 | } |
| 1347 | |
| 1348 | bm = g_new0(Qcow2Bitmap, 1); |
| 1349 | bm->name = g_strdup(name); |
| 1350 | QSIMPLEQ_INSERT_TAIL(bm_list, bm, entry); |
| 1351 | } else { |
| 1352 | if (!(bm->flags & BME_FLAG_IN_USE)) { |
| 1353 | error_setg(errp, "Bitmap '%s' already exists in the image", |
| 1354 | name); |
| 1355 | goto fail; |
| 1356 | } |
| 1357 | tb = g_memdup(&bm->table, sizeof(bm->table)); |
| 1358 | bm->table.offset = 0; |
| 1359 | bm->table.size = 0; |
| 1360 | QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry); |
| 1361 | } |
| 1362 | bm->flags = bdrv_dirty_bitmap_get_autoload(bitmap) ? BME_FLAG_AUTO : 0; |
| 1363 | bm->granularity_bits = ctz32(bdrv_dirty_bitmap_granularity(bitmap)); |
| 1364 | bm->dirty_bitmap = bitmap; |
| 1365 | } |
| 1366 | |
| 1367 | /* allocate clusters and store bitmaps */ |
| 1368 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 1369 | if (bm->dirty_bitmap == NULL) { |
| 1370 | continue; |
| 1371 | } |
| 1372 | |
| 1373 | ret = store_bitmap(bs, bm, errp); |
| 1374 | if (ret < 0) { |
| 1375 | goto fail; |
| 1376 | } |
| 1377 | } |
| 1378 | |
| 1379 | ret = update_ext_header_and_dir(bs, bm_list); |
| 1380 | if (ret < 0) { |
| 1381 | error_setg_errno(errp, -ret, "Failed to update bitmap extension"); |
| 1382 | goto fail; |
| 1383 | } |
| 1384 | |
| 1385 | /* Bitmap directory was successfully updated, so, old data can be dropped. |
| 1386 | * TODO it is better to reuse these clusters */ |
| 1387 | QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { |
| 1388 | free_bitmap_clusters(bs, tb); |
| 1389 | g_free(tb); |
| 1390 | } |
| 1391 | |
| 1392 | bitmap_list_free(bm_list); |
| 1393 | return; |
| 1394 | |
| 1395 | fail: |
| 1396 | QSIMPLEQ_FOREACH(bm, bm_list, entry) { |
| 1397 | if (bm->dirty_bitmap == NULL || bm->table.offset == 0) { |
| 1398 | continue; |
| 1399 | } |
| 1400 | |
| 1401 | free_bitmap_clusters(bs, &bm->table); |
| 1402 | } |
| 1403 | |
| 1404 | QSIMPLEQ_FOREACH_SAFE(tb, &drop_tables, entry, tb_next) { |
| 1405 | g_free(tb); |
| 1406 | } |
| 1407 | |
| 1408 | bitmap_list_free(bm_list); |
| 1409 | } |
Vladimir Sementsov-Ogievskiy | 169b879 | 2017-06-28 15:05:20 +0300 | [diff] [blame] | 1410 | |
| 1411 | int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp) |
| 1412 | { |
| 1413 | BdrvDirtyBitmap *bitmap; |
| 1414 | Error *local_err = NULL; |
| 1415 | |
| 1416 | qcow2_store_persistent_dirty_bitmaps(bs, &local_err); |
| 1417 | if (local_err != NULL) { |
| 1418 | error_propagate(errp, local_err); |
| 1419 | return -EINVAL; |
| 1420 | } |
| 1421 | |
| 1422 | for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; |
| 1423 | bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) |
| 1424 | { |
| 1425 | if (bdrv_dirty_bitmap_get_persistance(bitmap)) { |
| 1426 | bdrv_dirty_bitmap_set_readonly(bitmap, true); |
| 1427 | } |
| 1428 | } |
| 1429 | |
| 1430 | return 0; |
| 1431 | } |
Vladimir Sementsov-Ogievskiy | da0eb24 | 2017-06-28 15:05:22 +0300 | [diff] [blame] | 1432 | |
| 1433 | bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, |
| 1434 | const char *name, |
| 1435 | uint32_t granularity, |
| 1436 | Error **errp) |
| 1437 | { |
| 1438 | BDRVQcow2State *s = bs->opaque; |
| 1439 | bool found; |
| 1440 | Qcow2BitmapList *bm_list; |
| 1441 | |
| 1442 | if (check_constraints_on_bitmap(bs, name, granularity, errp) != 0) { |
| 1443 | goto fail; |
| 1444 | } |
| 1445 | |
| 1446 | if (s->nb_bitmaps == 0) { |
| 1447 | return true; |
| 1448 | } |
| 1449 | |
| 1450 | if (s->nb_bitmaps >= QCOW2_MAX_BITMAPS) { |
| 1451 | error_setg(errp, |
| 1452 | "Maximum number of persistent bitmaps is already reached"); |
| 1453 | goto fail; |
| 1454 | } |
| 1455 | |
| 1456 | if (s->bitmap_directory_size + calc_dir_entry_size(strlen(name), 0) > |
| 1457 | QCOW2_MAX_BITMAP_DIRECTORY_SIZE) |
| 1458 | { |
| 1459 | error_setg(errp, "Not enough space in the bitmap directory"); |
| 1460 | goto fail; |
| 1461 | } |
| 1462 | |
| 1463 | bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, |
| 1464 | s->bitmap_directory_size, errp); |
| 1465 | if (bm_list == NULL) { |
| 1466 | goto fail; |
| 1467 | } |
| 1468 | |
| 1469 | found = find_bitmap_by_name(bm_list, name); |
| 1470 | bitmap_list_free(bm_list); |
| 1471 | if (found) { |
| 1472 | error_setg(errp, "Bitmap with the same name is already stored"); |
| 1473 | goto fail; |
| 1474 | } |
| 1475 | |
| 1476 | return true; |
| 1477 | |
| 1478 | fail: |
| 1479 | error_prepend(errp, "Can't make bitmap '%s' persistent in '%s': ", |
| 1480 | name, bdrv_get_device_or_node_name(bs)); |
| 1481 | return false; |
| 1482 | } |