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 #ifndef BLOCK_QCOW2_H 26 #define BLOCK_QCOW2_H 27 28 #include "qemu/aes.h" 29 #include "block/coroutine.h" 30 31 //#define DEBUG_ALLOC 32 //#define DEBUG_ALLOC2 33 //#define DEBUG_EXT 34 35 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) 36 37 #define QCOW_CRYPT_NONE 0 38 #define QCOW_CRYPT_AES 1 39 40 #define QCOW_MAX_CRYPT_CLUSTERS 32 41 #define QCOW_MAX_SNAPSHOTS 65536 42 43 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size 44 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 45 #define QCOW_MAX_REFTABLE_SIZE 0x800000 46 47 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size 48 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 49 #define QCOW_MAX_L1_SIZE 0x2000000 50 51 /* Allow for an average of 1k per snapshot table entry, should be plenty of 52 * space for snapshot names and IDs */ 53 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) 54 55 /* indicate that the refcount of the referenced cluster is exactly one. */ 56 #define QCOW_OFLAG_COPIED (1ULL << 63) 57 /* indicate that the cluster is compressed (they never have the copied flag) */ 58 #define QCOW_OFLAG_COMPRESSED (1ULL << 62) 59 /* The cluster reads as all zeros */ 60 #define QCOW_OFLAG_ZERO (1ULL << 0) 61 62 #define MIN_CLUSTER_BITS 9 63 #define MAX_CLUSTER_BITS 21 64 65 #define MIN_L2_CACHE_SIZE 1 /* cluster */ 66 67 /* Must be at least 4 to cover all cases of refcount table growth */ 68 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ 69 70 #define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */ 71 72 /* The refblock cache needs only a fourth of the L2 cache size to cover as many 73 * clusters */ 74 #define DEFAULT_L2_REFCOUNT_SIZE_RATIO 4 75 76 #define DEFAULT_CLUSTER_SIZE 65536 77 78 79 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" 80 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" 81 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" 82 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other" 83 #define QCOW2_OPT_OVERLAP "overlap-check" 84 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template" 85 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header" 86 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1" 87 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2" 88 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table" 89 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block" 90 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table" 91 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1" 92 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" 93 #define QCOW2_OPT_CACHE_SIZE "cache-size" 94 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" 95 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" 96 97 typedef struct QCowHeader { 98 uint32_t magic; 99 uint32_t version; 100 uint64_t backing_file_offset; 101 uint32_t backing_file_size; 102 uint32_t cluster_bits; 103 uint64_t size; /* in bytes */ 104 uint32_t crypt_method; 105 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 106 uint64_t l1_table_offset; 107 uint64_t refcount_table_offset; 108 uint32_t refcount_table_clusters; 109 uint32_t nb_snapshots; 110 uint64_t snapshots_offset; 111 112 /* The following fields are only valid for version >= 3 */ 113 uint64_t incompatible_features; 114 uint64_t compatible_features; 115 uint64_t autoclear_features; 116 117 uint32_t refcount_order; 118 uint32_t header_length; 119 } QEMU_PACKED QCowHeader; 120 121 typedef struct QEMU_PACKED QCowSnapshotHeader { 122 /* header is 8 byte aligned */ 123 uint64_t l1_table_offset; 124 125 uint32_t l1_size; 126 uint16_t id_str_size; 127 uint16_t name_size; 128 129 uint32_t date_sec; 130 uint32_t date_nsec; 131 132 uint64_t vm_clock_nsec; 133 134 uint32_t vm_state_size; 135 uint32_t extra_data_size; /* for extension */ 136 /* extra data follows */ 137 /* id_str follows */ 138 /* name follows */ 139 } QCowSnapshotHeader; 140 141 typedef struct QEMU_PACKED QCowSnapshotExtraData { 142 uint64_t vm_state_size_large; 143 uint64_t disk_size; 144 } QCowSnapshotExtraData; 145 146 147 typedef struct QCowSnapshot { 148 uint64_t l1_table_offset; 149 uint32_t l1_size; 150 char *id_str; 151 char *name; 152 uint64_t disk_size; 153 uint64_t vm_state_size; 154 uint32_t date_sec; 155 uint32_t date_nsec; 156 uint64_t vm_clock_nsec; 157 } QCowSnapshot; 158 159 struct Qcow2Cache; 160 typedef struct Qcow2Cache Qcow2Cache; 161 162 typedef struct Qcow2UnknownHeaderExtension { 163 uint32_t magic; 164 uint32_t len; 165 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 166 uint8_t data[]; 167 } Qcow2UnknownHeaderExtension; 168 169 enum { 170 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, 171 QCOW2_FEAT_TYPE_COMPATIBLE = 1, 172 QCOW2_FEAT_TYPE_AUTOCLEAR = 2, 173 }; 174 175 /* Incompatible feature bits */ 176 enum { 177 QCOW2_INCOMPAT_DIRTY_BITNR = 0, 178 QCOW2_INCOMPAT_CORRUPT_BITNR = 1, 179 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, 180 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, 181 182 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY 183 | QCOW2_INCOMPAT_CORRUPT, 184 }; 185 186 /* Compatible feature bits */ 187 enum { 188 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0, 189 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 190 191 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, 192 }; 193 194 enum qcow2_discard_type { 195 QCOW2_DISCARD_NEVER = 0, 196 QCOW2_DISCARD_ALWAYS, 197 QCOW2_DISCARD_REQUEST, 198 QCOW2_DISCARD_SNAPSHOT, 199 QCOW2_DISCARD_OTHER, 200 QCOW2_DISCARD_MAX 201 }; 202 203 typedef struct Qcow2Feature { 204 uint8_t type; 205 uint8_t bit; 206 char name[46]; 207 } QEMU_PACKED Qcow2Feature; 208 209 typedef struct Qcow2DiscardRegion { 210 BlockDriverState *bs; 211 uint64_t offset; 212 uint64_t bytes; 213 QTAILQ_ENTRY(Qcow2DiscardRegion) next; 214 } Qcow2DiscardRegion; 215 216 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, 217 uint64_t index); 218 typedef void Qcow2SetRefcountFunc(void *refcount_array, 219 uint64_t index, uint64_t value); 220 221 typedef struct BDRVQcowState { 222 int cluster_bits; 223 int cluster_size; 224 int cluster_sectors; 225 int l2_bits; 226 int l2_size; 227 int l1_size; 228 int l1_vm_state_index; 229 int refcount_block_bits; 230 int refcount_block_size; 231 int csize_shift; 232 int csize_mask; 233 uint64_t cluster_offset_mask; 234 uint64_t l1_table_offset; 235 uint64_t *l1_table; 236 237 Qcow2Cache* l2_table_cache; 238 Qcow2Cache* refcount_block_cache; 239 240 uint8_t *cluster_cache; 241 uint8_t *cluster_data; 242 uint64_t cluster_cache_offset; 243 QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs; 244 245 uint64_t *refcount_table; 246 uint64_t refcount_table_offset; 247 uint32_t refcount_table_size; 248 uint64_t free_cluster_index; 249 uint64_t free_byte_offset; 250 251 CoMutex lock; 252 253 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ 254 uint32_t crypt_method_header; 255 AES_KEY aes_encrypt_key; 256 AES_KEY aes_decrypt_key; 257 uint64_t snapshots_offset; 258 int snapshots_size; 259 unsigned int nb_snapshots; 260 QCowSnapshot *snapshots; 261 262 int flags; 263 int qcow_version; 264 bool use_lazy_refcounts; 265 int refcount_order; 266 int refcount_bits; 267 uint64_t refcount_max; 268 269 Qcow2GetRefcountFunc *get_refcount; 270 Qcow2SetRefcountFunc *set_refcount; 271 272 bool discard_passthrough[QCOW2_DISCARD_MAX]; 273 274 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */ 275 bool signaled_corruption; 276 277 uint64_t incompatible_features; 278 uint64_t compatible_features; 279 uint64_t autoclear_features; 280 281 size_t unknown_header_fields_size; 282 void* unknown_header_fields; 283 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 284 QTAILQ_HEAD (, Qcow2DiscardRegion) discards; 285 bool cache_discards; 286 287 /* Backing file path and format as stored in the image (this is not the 288 * effective path/format, which may be the result of a runtime option 289 * override) */ 290 char *image_backing_file; 291 char *image_backing_format; 292 } BDRVQcowState; 293 294 struct QCowAIOCB; 295 296 typedef struct Qcow2COWRegion { 297 /** 298 * Offset of the COW region in bytes from the start of the first cluster 299 * touched by the request. 300 */ 301 uint64_t offset; 302 303 /** Number of sectors to copy */ 304 int nb_sectors; 305 } Qcow2COWRegion; 306 307 /** 308 * Describes an in-flight (part of a) write request that writes to clusters 309 * that are not referenced in their L2 table yet. 310 */ 311 typedef struct QCowL2Meta 312 { 313 /** Guest offset of the first newly allocated cluster */ 314 uint64_t offset; 315 316 /** Host offset of the first newly allocated cluster */ 317 uint64_t alloc_offset; 318 319 /** 320 * Number of sectors from the start of the first allocated cluster to 321 * the end of the (possibly shortened) request 322 */ 323 int nb_available; 324 325 /** Number of newly allocated clusters */ 326 int nb_clusters; 327 328 /** 329 * Requests that overlap with this allocation and wait to be restarted 330 * when the allocating request has completed. 331 */ 332 CoQueue dependent_requests; 333 334 /** 335 * The COW Region between the start of the first allocated cluster and the 336 * area the guest actually writes to. 337 */ 338 Qcow2COWRegion cow_start; 339 340 /** 341 * The COW Region between the area the guest actually writes to and the 342 * end of the last allocated cluster. 343 */ 344 Qcow2COWRegion cow_end; 345 346 /** Pointer to next L2Meta of the same write request */ 347 struct QCowL2Meta *next; 348 349 QLIST_ENTRY(QCowL2Meta) next_in_flight; 350 } QCowL2Meta; 351 352 enum { 353 QCOW2_CLUSTER_UNALLOCATED, 354 QCOW2_CLUSTER_NORMAL, 355 QCOW2_CLUSTER_COMPRESSED, 356 QCOW2_CLUSTER_ZERO 357 }; 358 359 typedef enum QCow2MetadataOverlap { 360 QCOW2_OL_MAIN_HEADER_BITNR = 0, 361 QCOW2_OL_ACTIVE_L1_BITNR = 1, 362 QCOW2_OL_ACTIVE_L2_BITNR = 2, 363 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3, 364 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4, 365 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5, 366 QCOW2_OL_INACTIVE_L1_BITNR = 6, 367 QCOW2_OL_INACTIVE_L2_BITNR = 7, 368 369 QCOW2_OL_MAX_BITNR = 8, 370 371 QCOW2_OL_NONE = 0, 372 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR), 373 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR), 374 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR), 375 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR), 376 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR), 377 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR), 378 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR), 379 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv 380 * reads. */ 381 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR), 382 } QCow2MetadataOverlap; 383 384 /* Perform all overlap checks which can be done in constant time */ 385 #define QCOW2_OL_CONSTANT \ 386 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \ 387 QCOW2_OL_SNAPSHOT_TABLE) 388 389 /* Perform all overlap checks which don't require disk access */ 390 #define QCOW2_OL_CACHED \ 391 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \ 392 QCOW2_OL_INACTIVE_L1) 393 394 /* Perform all overlap checks */ 395 #define QCOW2_OL_ALL \ 396 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2) 397 398 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL 399 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL 400 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL 401 402 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL 403 404 static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset) 405 { 406 return offset & ~(s->cluster_size - 1); 407 } 408 409 static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset) 410 { 411 return offset & (s->cluster_size - 1); 412 } 413 414 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 415 { 416 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 417 } 418 419 static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size) 420 { 421 int shift = s->cluster_bits + s->l2_bits; 422 return (size + (1ULL << shift) - 1) >> shift; 423 } 424 425 static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset) 426 { 427 return (offset >> s->cluster_bits) & (s->l2_size - 1); 428 } 429 430 static inline int64_t align_offset(int64_t offset, int n) 431 { 432 offset = (offset + n - 1) & ~(n - 1); 433 return offset; 434 } 435 436 static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s) 437 { 438 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); 439 } 440 441 static inline uint64_t qcow2_max_refcount_clusters(BDRVQcowState *s) 442 { 443 return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits; 444 } 445 446 static inline int qcow2_get_cluster_type(uint64_t l2_entry) 447 { 448 if (l2_entry & QCOW_OFLAG_COMPRESSED) { 449 return QCOW2_CLUSTER_COMPRESSED; 450 } else if (l2_entry & QCOW_OFLAG_ZERO) { 451 return QCOW2_CLUSTER_ZERO; 452 } else if (!(l2_entry & L2E_OFFSET_MASK)) { 453 return QCOW2_CLUSTER_UNALLOCATED; 454 } else { 455 return QCOW2_CLUSTER_NORMAL; 456 } 457 } 458 459 /* Check whether refcounts are eager or lazy */ 460 static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s) 461 { 462 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY); 463 } 464 465 static inline uint64_t l2meta_cow_start(QCowL2Meta *m) 466 { 467 return m->offset + m->cow_start.offset; 468 } 469 470 static inline uint64_t l2meta_cow_end(QCowL2Meta *m) 471 { 472 return m->offset + m->cow_end.offset 473 + (m->cow_end.nb_sectors << BDRV_SECTOR_BITS); 474 } 475 476 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2) 477 { 478 return r1 > r2 ? r1 - r2 : r2 - r1; 479 } 480 481 // FIXME Need qcow2_ prefix to global functions 482 483 /* qcow2.c functions */ 484 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 485 int64_t sector_num, int nb_sectors); 486 487 int qcow2_mark_dirty(BlockDriverState *bs); 488 int qcow2_mark_corrupt(BlockDriverState *bs); 489 int qcow2_mark_consistent(BlockDriverState *bs); 490 int qcow2_update_header(BlockDriverState *bs); 491 492 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 493 int64_t size, const char *message_format, ...) 494 GCC_FMT_ATTR(5, 6); 495 496 /* qcow2-refcount.c functions */ 497 int qcow2_refcount_init(BlockDriverState *bs); 498 void qcow2_refcount_close(BlockDriverState *bs); 499 500 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, 501 uint64_t *refcount); 502 503 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, 504 uint64_t addend, bool decrease, 505 enum qcow2_discard_type type); 506 507 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); 508 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, 509 int nb_clusters); 510 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 511 void qcow2_free_clusters(BlockDriverState *bs, 512 int64_t offset, int64_t size, 513 enum qcow2_discard_type type); 514 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, 515 int nb_clusters, enum qcow2_discard_type type); 516 517 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 518 int64_t l1_table_offset, int l1_size, int addend); 519 520 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 521 BdrvCheckMode fix); 522 523 void qcow2_process_discards(BlockDriverState *bs, int ret); 524 525 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, 526 int64_t size); 527 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, 528 int64_t size); 529 530 /* qcow2-cluster.c functions */ 531 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, 532 bool exact_size); 533 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); 534 void qcow2_l2_cache_reset(BlockDriverState *bs); 535 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 536 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 537 uint8_t *out_buf, const uint8_t *in_buf, 538 int nb_sectors, int enc, 539 const AES_KEY *key); 540 541 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 542 int *num, uint64_t *cluster_offset); 543 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 544 int *num, uint64_t *host_offset, QCowL2Meta **m); 545 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 546 uint64_t offset, 547 int compressed_size); 548 549 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 550 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, 551 int nb_sectors, enum qcow2_discard_type type, bool full_discard); 552 int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors); 553 554 int qcow2_expand_zero_clusters(BlockDriverState *bs, 555 BlockDriverAmendStatusCB *status_cb); 556 557 /* qcow2-snapshot.c functions */ 558 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 559 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 560 int qcow2_snapshot_delete(BlockDriverState *bs, 561 const char *snapshot_id, 562 const char *name, 563 Error **errp); 564 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 565 int qcow2_snapshot_load_tmp(BlockDriverState *bs, 566 const char *snapshot_id, 567 const char *name, 568 Error **errp); 569 570 void qcow2_free_snapshots(BlockDriverState *bs); 571 int qcow2_read_snapshots(BlockDriverState *bs); 572 573 /* qcow2-cache.c functions */ 574 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables); 575 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c); 576 577 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 578 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 579 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 580 Qcow2Cache *dependency); 581 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 582 583 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c); 584 585 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 586 void **table); 587 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 588 void **table); 589 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 590 591 #endif 592