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 "crypto/block.h" 29 #include "qemu/coroutine.h" 30 #include "qemu/units.h" 31 32 //#define DEBUG_ALLOC 33 //#define DEBUG_ALLOC2 34 //#define DEBUG_EXT 35 36 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) 37 38 #define QCOW_CRYPT_NONE 0 39 #define QCOW_CRYPT_AES 1 40 #define QCOW_CRYPT_LUKS 2 41 42 #define QCOW_MAX_CRYPT_CLUSTERS 32 43 #define QCOW_MAX_SNAPSHOTS 65536 44 45 /* Field widths in qcow2 mean normal cluster offsets cannot reach 46 * 64PB; depending on cluster size, compressed clusters can have a 47 * smaller limit (64PB for up to 16k clusters, then ramps down to 48 * 512TB for 2M clusters). */ 49 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) 50 51 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size 52 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 53 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB) 54 55 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size 56 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 57 #define QCOW_MAX_L1_SIZE (32 * MiB) 58 59 /* Allow for an average of 1k per snapshot table entry, should be plenty of 60 * space for snapshot names and IDs */ 61 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) 62 63 /* Bitmap header extension constraints */ 64 #define QCOW2_MAX_BITMAPS 65535 65 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) 66 67 /* indicate that the refcount of the referenced cluster is exactly one. */ 68 #define QCOW_OFLAG_COPIED (1ULL << 63) 69 /* indicate that the cluster is compressed (they never have the copied flag) */ 70 #define QCOW_OFLAG_COMPRESSED (1ULL << 62) 71 /* The cluster reads as all zeros */ 72 #define QCOW_OFLAG_ZERO (1ULL << 0) 73 74 #define MIN_CLUSTER_BITS 9 75 #define MAX_CLUSTER_BITS 21 76 77 /* Defined in the qcow2 spec (compressed cluster descriptor) */ 78 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U 79 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1)) 80 81 /* Must be at least 2 to cover COW */ 82 #define MIN_L2_CACHE_SIZE 2 /* cache entries */ 83 84 /* Must be at least 4 to cover all cases of refcount table growth */ 85 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ 86 87 #ifdef CONFIG_LINUX 88 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) 89 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ 90 #else 91 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB) 92 /* Cache clean interval is currently available only on Linux, so must be 0 */ 93 #define DEFAULT_CACHE_CLEAN_INTERVAL 0 94 #endif 95 96 #define DEFAULT_CLUSTER_SIZE 65536 97 98 #define QCOW2_OPT_DATA_FILE "data-file" 99 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" 100 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" 101 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" 102 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other" 103 #define QCOW2_OPT_OVERLAP "overlap-check" 104 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template" 105 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header" 106 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1" 107 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2" 108 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table" 109 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block" 110 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table" 111 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1" 112 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" 113 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory" 114 #define QCOW2_OPT_CACHE_SIZE "cache-size" 115 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" 116 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size" 117 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" 118 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval" 119 120 typedef struct QCowHeader { 121 uint32_t magic; 122 uint32_t version; 123 uint64_t backing_file_offset; 124 uint32_t backing_file_size; 125 uint32_t cluster_bits; 126 uint64_t size; /* in bytes */ 127 uint32_t crypt_method; 128 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 129 uint64_t l1_table_offset; 130 uint64_t refcount_table_offset; 131 uint32_t refcount_table_clusters; 132 uint32_t nb_snapshots; 133 uint64_t snapshots_offset; 134 135 /* The following fields are only valid for version >= 3 */ 136 uint64_t incompatible_features; 137 uint64_t compatible_features; 138 uint64_t autoclear_features; 139 140 uint32_t refcount_order; 141 uint32_t header_length; 142 } QEMU_PACKED QCowHeader; 143 144 typedef struct QEMU_PACKED QCowSnapshotHeader { 145 /* header is 8 byte aligned */ 146 uint64_t l1_table_offset; 147 148 uint32_t l1_size; 149 uint16_t id_str_size; 150 uint16_t name_size; 151 152 uint32_t date_sec; 153 uint32_t date_nsec; 154 155 uint64_t vm_clock_nsec; 156 157 uint32_t vm_state_size; 158 uint32_t extra_data_size; /* for extension */ 159 /* extra data follows */ 160 /* id_str follows */ 161 /* name follows */ 162 } QCowSnapshotHeader; 163 164 typedef struct QEMU_PACKED QCowSnapshotExtraData { 165 uint64_t vm_state_size_large; 166 uint64_t disk_size; 167 } QCowSnapshotExtraData; 168 169 170 typedef struct QCowSnapshot { 171 uint64_t l1_table_offset; 172 uint32_t l1_size; 173 char *id_str; 174 char *name; 175 uint64_t disk_size; 176 uint64_t vm_state_size; 177 uint32_t date_sec; 178 uint32_t date_nsec; 179 uint64_t vm_clock_nsec; 180 } QCowSnapshot; 181 182 struct Qcow2Cache; 183 typedef struct Qcow2Cache Qcow2Cache; 184 185 typedef struct Qcow2CryptoHeaderExtension { 186 uint64_t offset; 187 uint64_t length; 188 } QEMU_PACKED Qcow2CryptoHeaderExtension; 189 190 typedef struct Qcow2UnknownHeaderExtension { 191 uint32_t magic; 192 uint32_t len; 193 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 194 uint8_t data[]; 195 } Qcow2UnknownHeaderExtension; 196 197 enum { 198 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, 199 QCOW2_FEAT_TYPE_COMPATIBLE = 1, 200 QCOW2_FEAT_TYPE_AUTOCLEAR = 2, 201 }; 202 203 /* Incompatible feature bits */ 204 enum { 205 QCOW2_INCOMPAT_DIRTY_BITNR = 0, 206 QCOW2_INCOMPAT_CORRUPT_BITNR = 1, 207 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2, 208 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, 209 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, 210 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR, 211 212 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY 213 | QCOW2_INCOMPAT_CORRUPT 214 | QCOW2_INCOMPAT_DATA_FILE, 215 }; 216 217 /* Compatible feature bits */ 218 enum { 219 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0, 220 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 221 222 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, 223 }; 224 225 /* Autoclear feature bits */ 226 enum { 227 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0, 228 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, 229 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR, 230 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 231 232 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS 233 | QCOW2_AUTOCLEAR_DATA_FILE_RAW, 234 }; 235 236 enum qcow2_discard_type { 237 QCOW2_DISCARD_NEVER = 0, 238 QCOW2_DISCARD_ALWAYS, 239 QCOW2_DISCARD_REQUEST, 240 QCOW2_DISCARD_SNAPSHOT, 241 QCOW2_DISCARD_OTHER, 242 QCOW2_DISCARD_MAX 243 }; 244 245 typedef struct Qcow2Feature { 246 uint8_t type; 247 uint8_t bit; 248 char name[46]; 249 } QEMU_PACKED Qcow2Feature; 250 251 typedef struct Qcow2DiscardRegion { 252 BlockDriverState *bs; 253 uint64_t offset; 254 uint64_t bytes; 255 QTAILQ_ENTRY(Qcow2DiscardRegion) next; 256 } Qcow2DiscardRegion; 257 258 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, 259 uint64_t index); 260 typedef void Qcow2SetRefcountFunc(void *refcount_array, 261 uint64_t index, uint64_t value); 262 263 typedef struct Qcow2BitmapHeaderExt { 264 uint32_t nb_bitmaps; 265 uint32_t reserved32; 266 uint64_t bitmap_directory_size; 267 uint64_t bitmap_directory_offset; 268 } QEMU_PACKED Qcow2BitmapHeaderExt; 269 270 typedef struct BDRVQcow2State { 271 int cluster_bits; 272 int cluster_size; 273 int l2_slice_size; 274 int l2_bits; 275 int l2_size; 276 int l1_size; 277 int l1_vm_state_index; 278 int refcount_block_bits; 279 int refcount_block_size; 280 int csize_shift; 281 int csize_mask; 282 uint64_t cluster_offset_mask; 283 uint64_t l1_table_offset; 284 uint64_t *l1_table; 285 286 Qcow2Cache* l2_table_cache; 287 Qcow2Cache* refcount_block_cache; 288 QEMUTimer *cache_clean_timer; 289 unsigned cache_clean_interval; 290 291 uint8_t *cluster_cache; 292 uint8_t *cluster_data; 293 uint64_t cluster_cache_offset; 294 QLIST_HEAD(, QCowL2Meta) cluster_allocs; 295 296 uint64_t *refcount_table; 297 uint64_t refcount_table_offset; 298 uint32_t refcount_table_size; 299 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */ 300 uint64_t free_cluster_index; 301 uint64_t free_byte_offset; 302 303 CoMutex lock; 304 305 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */ 306 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 307 QCryptoBlock *crypto; /* Disk encryption format driver */ 308 bool crypt_physical_offset; /* Whether to use virtual or physical offset 309 for encryption initialization vector tweak */ 310 uint32_t crypt_method_header; 311 uint64_t snapshots_offset; 312 int snapshots_size; 313 unsigned int nb_snapshots; 314 QCowSnapshot *snapshots; 315 316 uint32_t nb_bitmaps; 317 uint64_t bitmap_directory_size; 318 uint64_t bitmap_directory_offset; 319 320 int flags; 321 int qcow_version; 322 bool use_lazy_refcounts; 323 int refcount_order; 324 int refcount_bits; 325 uint64_t refcount_max; 326 327 Qcow2GetRefcountFunc *get_refcount; 328 Qcow2SetRefcountFunc *set_refcount; 329 330 bool discard_passthrough[QCOW2_DISCARD_MAX]; 331 332 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */ 333 bool signaled_corruption; 334 335 uint64_t incompatible_features; 336 uint64_t compatible_features; 337 uint64_t autoclear_features; 338 339 size_t unknown_header_fields_size; 340 void* unknown_header_fields; 341 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 342 QTAILQ_HEAD (, Qcow2DiscardRegion) discards; 343 bool cache_discards; 344 345 /* Backing file path and format as stored in the image (this is not the 346 * effective path/format, which may be the result of a runtime option 347 * override) */ 348 char *image_backing_file; 349 char *image_backing_format; 350 char *image_data_file; 351 352 CoQueue compress_wait_queue; 353 int nb_compress_threads; 354 355 BdrvChild *data_file; 356 } BDRVQcow2State; 357 358 typedef struct Qcow2COWRegion { 359 /** 360 * Offset of the COW region in bytes from the start of the first cluster 361 * touched by the request. 362 */ 363 unsigned offset; 364 365 /** Number of bytes to copy */ 366 unsigned nb_bytes; 367 } Qcow2COWRegion; 368 369 /** 370 * Describes an in-flight (part of a) write request that writes to clusters 371 * that are not referenced in their L2 table yet. 372 */ 373 typedef struct QCowL2Meta 374 { 375 /** Guest offset of the first newly allocated cluster */ 376 uint64_t offset; 377 378 /** Host offset of the first newly allocated cluster */ 379 uint64_t alloc_offset; 380 381 /** Number of newly allocated clusters */ 382 int nb_clusters; 383 384 /** Do not free the old clusters */ 385 bool keep_old_clusters; 386 387 /** 388 * Requests that overlap with this allocation and wait to be restarted 389 * when the allocating request has completed. 390 */ 391 CoQueue dependent_requests; 392 393 /** 394 * The COW Region between the start of the first allocated cluster and the 395 * area the guest actually writes to. 396 */ 397 Qcow2COWRegion cow_start; 398 399 /** 400 * The COW Region between the area the guest actually writes to and the 401 * end of the last allocated cluster. 402 */ 403 Qcow2COWRegion cow_end; 404 405 /** 406 * The I/O vector with the data from the actual guest write request. 407 * If non-NULL, this is meant to be merged together with the data 408 * from @cow_start and @cow_end into one single write operation. 409 */ 410 QEMUIOVector *data_qiov; 411 412 /** Pointer to next L2Meta of the same write request */ 413 struct QCowL2Meta *next; 414 415 QLIST_ENTRY(QCowL2Meta) next_in_flight; 416 } QCowL2Meta; 417 418 typedef enum QCow2ClusterType { 419 QCOW2_CLUSTER_UNALLOCATED, 420 QCOW2_CLUSTER_ZERO_PLAIN, 421 QCOW2_CLUSTER_ZERO_ALLOC, 422 QCOW2_CLUSTER_NORMAL, 423 QCOW2_CLUSTER_COMPRESSED, 424 } QCow2ClusterType; 425 426 typedef enum QCow2MetadataOverlap { 427 QCOW2_OL_MAIN_HEADER_BITNR = 0, 428 QCOW2_OL_ACTIVE_L1_BITNR = 1, 429 QCOW2_OL_ACTIVE_L2_BITNR = 2, 430 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3, 431 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4, 432 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5, 433 QCOW2_OL_INACTIVE_L1_BITNR = 6, 434 QCOW2_OL_INACTIVE_L2_BITNR = 7, 435 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8, 436 437 QCOW2_OL_MAX_BITNR = 9, 438 439 QCOW2_OL_NONE = 0, 440 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR), 441 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR), 442 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR), 443 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR), 444 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR), 445 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR), 446 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR), 447 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv 448 * reads. */ 449 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR), 450 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR), 451 } QCow2MetadataOverlap; 452 453 /* Perform all overlap checks which can be done in constant time */ 454 #define QCOW2_OL_CONSTANT \ 455 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \ 456 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY) 457 458 /* Perform all overlap checks which don't require disk access */ 459 #define QCOW2_OL_CACHED \ 460 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \ 461 QCOW2_OL_INACTIVE_L1) 462 463 /* Perform all overlap checks */ 464 #define QCOW2_OL_ALL \ 465 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2) 466 467 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL 468 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL 469 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL 470 471 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL 472 473 #define INV_OFFSET (-1ULL) 474 475 static inline bool has_data_file(BlockDriverState *bs) 476 { 477 BDRVQcow2State *s = bs->opaque; 478 return (s->data_file != bs->file); 479 } 480 481 static inline bool data_file_is_raw(BlockDriverState *bs) 482 { 483 BDRVQcow2State *s = bs->opaque; 484 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW); 485 } 486 487 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset) 488 { 489 return offset & ~(s->cluster_size - 1); 490 } 491 492 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset) 493 { 494 return offset & (s->cluster_size - 1); 495 } 496 497 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size) 498 { 499 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 500 } 501 502 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size) 503 { 504 int shift = s->cluster_bits + s->l2_bits; 505 return (size + (1ULL << shift) - 1) >> shift; 506 } 507 508 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset) 509 { 510 return offset >> (s->l2_bits + s->cluster_bits); 511 } 512 513 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset) 514 { 515 return (offset >> s->cluster_bits) & (s->l2_size - 1); 516 } 517 518 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset) 519 { 520 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1); 521 } 522 523 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s) 524 { 525 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); 526 } 527 528 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs, 529 uint64_t l2_entry) 530 { 531 if (l2_entry & QCOW_OFLAG_COMPRESSED) { 532 return QCOW2_CLUSTER_COMPRESSED; 533 } else if (l2_entry & QCOW_OFLAG_ZERO) { 534 if (l2_entry & L2E_OFFSET_MASK) { 535 return QCOW2_CLUSTER_ZERO_ALLOC; 536 } 537 return QCOW2_CLUSTER_ZERO_PLAIN; 538 } else if (!(l2_entry & L2E_OFFSET_MASK)) { 539 /* Offset 0 generally means unallocated, but it is ambiguous with 540 * external data files because 0 is a valid offset there. However, all 541 * clusters in external data files always have refcount 1, so we can 542 * rely on QCOW_OFLAG_COPIED to disambiguate. */ 543 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) { 544 return QCOW2_CLUSTER_NORMAL; 545 } else { 546 return QCOW2_CLUSTER_UNALLOCATED; 547 } 548 } else { 549 return QCOW2_CLUSTER_NORMAL; 550 } 551 } 552 553 /* Check whether refcounts are eager or lazy */ 554 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s) 555 { 556 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY); 557 } 558 559 static inline uint64_t l2meta_cow_start(QCowL2Meta *m) 560 { 561 return m->offset + m->cow_start.offset; 562 } 563 564 static inline uint64_t l2meta_cow_end(QCowL2Meta *m) 565 { 566 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes; 567 } 568 569 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2) 570 { 571 return r1 > r2 ? r1 - r2 : r2 - r1; 572 } 573 574 static inline 575 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset) 576 { 577 return offset >> (s->refcount_block_bits + s->cluster_bits); 578 } 579 580 /* qcow2.c functions */ 581 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 582 int refcount_order, bool generous_increase, 583 uint64_t *refblock_count); 584 585 int qcow2_mark_dirty(BlockDriverState *bs); 586 int qcow2_mark_corrupt(BlockDriverState *bs); 587 int qcow2_mark_consistent(BlockDriverState *bs); 588 int qcow2_update_header(BlockDriverState *bs); 589 590 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 591 int64_t size, const char *message_format, ...) 592 GCC_FMT_ATTR(5, 6); 593 594 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 595 uint64_t entries, size_t entry_len, 596 int64_t max_size_bytes, const char *table_name, 597 Error **errp); 598 599 /* qcow2-refcount.c functions */ 600 int qcow2_refcount_init(BlockDriverState *bs); 601 void qcow2_refcount_close(BlockDriverState *bs); 602 603 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, 604 uint64_t *refcount); 605 606 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, 607 uint64_t addend, bool decrease, 608 enum qcow2_discard_type type); 609 610 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset, 611 uint64_t additional_clusters, bool exact_size, 612 int new_refblock_index, 613 uint64_t new_refblock_offset); 614 615 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); 616 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, 617 int64_t nb_clusters); 618 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 619 void qcow2_free_clusters(BlockDriverState *bs, 620 int64_t offset, int64_t size, 621 enum qcow2_discard_type type); 622 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, 623 int nb_clusters, enum qcow2_discard_type type); 624 625 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 626 int64_t l1_table_offset, int l1_size, int addend); 627 628 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs); 629 int coroutine_fn qcow2_write_caches(BlockDriverState *bs); 630 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 631 BdrvCheckMode fix); 632 633 void qcow2_process_discards(BlockDriverState *bs, int ret); 634 635 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, 636 int64_t size); 637 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, 638 int64_t size, bool data_file); 639 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res, 640 void **refcount_table, 641 int64_t *refcount_table_size, 642 int64_t offset, int64_t size); 643 644 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, 645 BlockDriverAmendStatusCB *status_cb, 646 void *cb_opaque, Error **errp); 647 int qcow2_shrink_reftable(BlockDriverState *bs); 648 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size); 649 650 /* qcow2-cluster.c functions */ 651 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, 652 bool exact_size); 653 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size); 654 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); 655 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num, 656 uint8_t *buf, int nb_sectors, bool enc, Error **errp); 657 658 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 659 unsigned int *bytes, uint64_t *cluster_offset); 660 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 661 unsigned int *bytes, uint64_t *host_offset, 662 QCowL2Meta **m); 663 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 664 uint64_t offset, 665 int compressed_size, 666 uint64_t *host_offset); 667 668 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 669 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m); 670 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, 671 uint64_t bytes, enum qcow2_discard_type type, 672 bool full_discard); 673 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, 674 uint64_t bytes, int flags); 675 676 int qcow2_expand_zero_clusters(BlockDriverState *bs, 677 BlockDriverAmendStatusCB *status_cb, 678 void *cb_opaque); 679 680 /* qcow2-snapshot.c functions */ 681 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 682 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 683 int qcow2_snapshot_delete(BlockDriverState *bs, 684 const char *snapshot_id, 685 const char *name, 686 Error **errp); 687 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 688 int qcow2_snapshot_load_tmp(BlockDriverState *bs, 689 const char *snapshot_id, 690 const char *name, 691 Error **errp); 692 693 void qcow2_free_snapshots(BlockDriverState *bs); 694 int qcow2_read_snapshots(BlockDriverState *bs); 695 696 /* qcow2-cache.c functions */ 697 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 698 unsigned table_size); 699 int qcow2_cache_destroy(Qcow2Cache *c); 700 701 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 702 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 703 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c); 704 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 705 Qcow2Cache *dependency); 706 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 707 708 void qcow2_cache_clean_unused(Qcow2Cache *c); 709 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c); 710 711 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 712 void **table); 713 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 714 void **table); 715 void qcow2_cache_put(Qcow2Cache *c, void **table); 716 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset); 717 void qcow2_cache_discard(Qcow2Cache *c, void *table); 718 719 /* qcow2-bitmap.c functions */ 720 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 721 void **refcount_table, 722 int64_t *refcount_table_size); 723 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp); 724 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs, 725 Error **errp); 726 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated, 727 Error **errp); 728 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp); 729 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp); 730 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp); 731 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp); 732 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, 733 const char *name, 734 uint32_t granularity, 735 Error **errp); 736 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs, 737 const char *name, 738 Error **errp); 739 740 #endif 741