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 #include "block/block_int.h" 32 33 //#define DEBUG_ALLOC 34 //#define DEBUG_ALLOC2 35 //#define DEBUG_EXT 36 37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) 38 39 #define QCOW_CRYPT_NONE 0 40 #define QCOW_CRYPT_AES 1 41 #define QCOW_CRYPT_LUKS 2 42 43 #define QCOW_MAX_CRYPT_CLUSTERS 32 44 #define QCOW_MAX_SNAPSHOTS 65536 45 46 /* Field widths in qcow2 mean normal cluster offsets cannot reach 47 * 64PB; depending on cluster size, compressed clusters can have a 48 * smaller limit (64PB for up to 16k clusters, then ramps down to 49 * 512TB for 2M clusters). */ 50 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) 51 52 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size 53 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 54 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB) 55 56 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size 57 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 58 #define QCOW_MAX_L1_SIZE (32 * MiB) 59 60 /* Allow for an average of 1k per snapshot table entry, should be plenty of 61 * space for snapshot names and IDs */ 62 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) 63 64 /* Bitmap header extension constraints */ 65 #define QCOW2_MAX_BITMAPS 65535 66 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) 67 68 /* Maximum of parallel sub-request per guest request */ 69 #define QCOW2_MAX_WORKERS 8 70 71 /* indicate that the refcount of the referenced cluster is exactly one. */ 72 #define QCOW_OFLAG_COPIED (1ULL << 63) 73 /* indicate that the cluster is compressed (they never have the copied flag) */ 74 #define QCOW_OFLAG_COMPRESSED (1ULL << 62) 75 /* The cluster reads as all zeros */ 76 #define QCOW_OFLAG_ZERO (1ULL << 0) 77 78 #define MIN_CLUSTER_BITS 9 79 #define MAX_CLUSTER_BITS 21 80 81 /* Defined in the qcow2 spec (compressed cluster descriptor) */ 82 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U 83 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1)) 84 85 /* Must be at least 2 to cover COW */ 86 #define MIN_L2_CACHE_SIZE 2 /* cache entries */ 87 88 /* Must be at least 4 to cover all cases of refcount table growth */ 89 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ 90 91 #ifdef CONFIG_LINUX 92 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) 93 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ 94 #else 95 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB) 96 /* Cache clean interval is currently available only on Linux, so must be 0 */ 97 #define DEFAULT_CACHE_CLEAN_INTERVAL 0 98 #endif 99 100 #define DEFAULT_CLUSTER_SIZE 65536 101 102 #define QCOW2_OPT_DATA_FILE "data-file" 103 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" 104 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" 105 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" 106 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other" 107 #define QCOW2_OPT_OVERLAP "overlap-check" 108 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template" 109 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header" 110 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1" 111 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2" 112 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table" 113 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block" 114 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table" 115 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1" 116 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" 117 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory" 118 #define QCOW2_OPT_CACHE_SIZE "cache-size" 119 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" 120 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size" 121 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" 122 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval" 123 124 typedef struct QCowHeader { 125 uint32_t magic; 126 uint32_t version; 127 uint64_t backing_file_offset; 128 uint32_t backing_file_size; 129 uint32_t cluster_bits; 130 uint64_t size; /* in bytes */ 131 uint32_t crypt_method; 132 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 133 uint64_t l1_table_offset; 134 uint64_t refcount_table_offset; 135 uint32_t refcount_table_clusters; 136 uint32_t nb_snapshots; 137 uint64_t snapshots_offset; 138 139 /* The following fields are only valid for version >= 3 */ 140 uint64_t incompatible_features; 141 uint64_t compatible_features; 142 uint64_t autoclear_features; 143 144 uint32_t refcount_order; 145 uint32_t header_length; 146 } QEMU_PACKED QCowHeader; 147 148 typedef struct QEMU_PACKED QCowSnapshotHeader { 149 /* header is 8 byte aligned */ 150 uint64_t l1_table_offset; 151 152 uint32_t l1_size; 153 uint16_t id_str_size; 154 uint16_t name_size; 155 156 uint32_t date_sec; 157 uint32_t date_nsec; 158 159 uint64_t vm_clock_nsec; 160 161 uint32_t vm_state_size; 162 uint32_t extra_data_size; /* for extension */ 163 /* extra data follows */ 164 /* id_str follows */ 165 /* name follows */ 166 } QCowSnapshotHeader; 167 168 typedef struct QEMU_PACKED QCowSnapshotExtraData { 169 uint64_t vm_state_size_large; 170 uint64_t disk_size; 171 } QCowSnapshotExtraData; 172 173 174 typedef struct QCowSnapshot { 175 uint64_t l1_table_offset; 176 uint32_t l1_size; 177 char *id_str; 178 char *name; 179 uint64_t disk_size; 180 uint64_t vm_state_size; 181 uint32_t date_sec; 182 uint32_t date_nsec; 183 uint64_t vm_clock_nsec; 184 } QCowSnapshot; 185 186 struct Qcow2Cache; 187 typedef struct Qcow2Cache Qcow2Cache; 188 189 typedef struct Qcow2CryptoHeaderExtension { 190 uint64_t offset; 191 uint64_t length; 192 } QEMU_PACKED Qcow2CryptoHeaderExtension; 193 194 typedef struct Qcow2UnknownHeaderExtension { 195 uint32_t magic; 196 uint32_t len; 197 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 198 uint8_t data[]; 199 } Qcow2UnknownHeaderExtension; 200 201 enum { 202 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, 203 QCOW2_FEAT_TYPE_COMPATIBLE = 1, 204 QCOW2_FEAT_TYPE_AUTOCLEAR = 2, 205 }; 206 207 /* Incompatible feature bits */ 208 enum { 209 QCOW2_INCOMPAT_DIRTY_BITNR = 0, 210 QCOW2_INCOMPAT_CORRUPT_BITNR = 1, 211 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2, 212 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, 213 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, 214 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR, 215 216 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY 217 | QCOW2_INCOMPAT_CORRUPT 218 | QCOW2_INCOMPAT_DATA_FILE, 219 }; 220 221 /* Compatible feature bits */ 222 enum { 223 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0, 224 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 225 226 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, 227 }; 228 229 /* Autoclear feature bits */ 230 enum { 231 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0, 232 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, 233 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR, 234 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 235 236 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS 237 | QCOW2_AUTOCLEAR_DATA_FILE_RAW, 238 }; 239 240 enum qcow2_discard_type { 241 QCOW2_DISCARD_NEVER = 0, 242 QCOW2_DISCARD_ALWAYS, 243 QCOW2_DISCARD_REQUEST, 244 QCOW2_DISCARD_SNAPSHOT, 245 QCOW2_DISCARD_OTHER, 246 QCOW2_DISCARD_MAX 247 }; 248 249 typedef struct Qcow2Feature { 250 uint8_t type; 251 uint8_t bit; 252 char name[46]; 253 } QEMU_PACKED Qcow2Feature; 254 255 typedef struct Qcow2DiscardRegion { 256 BlockDriverState *bs; 257 uint64_t offset; 258 uint64_t bytes; 259 QTAILQ_ENTRY(Qcow2DiscardRegion) next; 260 } Qcow2DiscardRegion; 261 262 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, 263 uint64_t index); 264 typedef void Qcow2SetRefcountFunc(void *refcount_array, 265 uint64_t index, uint64_t value); 266 267 typedef struct Qcow2BitmapHeaderExt { 268 uint32_t nb_bitmaps; 269 uint32_t reserved32; 270 uint64_t bitmap_directory_size; 271 uint64_t bitmap_directory_offset; 272 } QEMU_PACKED Qcow2BitmapHeaderExt; 273 274 #define QCOW2_MAX_THREADS 4 275 276 typedef struct BDRVQcow2State { 277 int cluster_bits; 278 int cluster_size; 279 int l2_slice_size; 280 int l2_bits; 281 int l2_size; 282 int l1_size; 283 int l1_vm_state_index; 284 int refcount_block_bits; 285 int refcount_block_size; 286 int csize_shift; 287 int csize_mask; 288 uint64_t cluster_offset_mask; 289 uint64_t l1_table_offset; 290 uint64_t *l1_table; 291 292 Qcow2Cache* l2_table_cache; 293 Qcow2Cache* refcount_block_cache; 294 QEMUTimer *cache_clean_timer; 295 unsigned cache_clean_interval; 296 297 uint8_t *cluster_cache; 298 uint8_t *cluster_data; 299 uint64_t cluster_cache_offset; 300 QLIST_HEAD(, QCowL2Meta) cluster_allocs; 301 302 uint64_t *refcount_table; 303 uint64_t refcount_table_offset; 304 uint32_t refcount_table_size; 305 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */ 306 uint64_t free_cluster_index; 307 uint64_t free_byte_offset; 308 309 CoMutex lock; 310 311 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */ 312 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 313 QCryptoBlock *crypto; /* Disk encryption format driver */ 314 bool crypt_physical_offset; /* Whether to use virtual or physical offset 315 for encryption initialization vector tweak */ 316 uint32_t crypt_method_header; 317 uint64_t snapshots_offset; 318 int snapshots_size; 319 unsigned int nb_snapshots; 320 QCowSnapshot *snapshots; 321 322 uint32_t nb_bitmaps; 323 uint64_t bitmap_directory_size; 324 uint64_t bitmap_directory_offset; 325 326 int flags; 327 int qcow_version; 328 bool use_lazy_refcounts; 329 int refcount_order; 330 int refcount_bits; 331 uint64_t refcount_max; 332 333 Qcow2GetRefcountFunc *get_refcount; 334 Qcow2SetRefcountFunc *set_refcount; 335 336 bool discard_passthrough[QCOW2_DISCARD_MAX]; 337 338 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */ 339 bool signaled_corruption; 340 341 uint64_t incompatible_features; 342 uint64_t compatible_features; 343 uint64_t autoclear_features; 344 345 size_t unknown_header_fields_size; 346 void* unknown_header_fields; 347 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 348 QTAILQ_HEAD (, Qcow2DiscardRegion) discards; 349 bool cache_discards; 350 351 /* Backing file path and format as stored in the image (this is not the 352 * effective path/format, which may be the result of a runtime option 353 * override) */ 354 char *image_backing_file; 355 char *image_backing_format; 356 char *image_data_file; 357 358 CoQueue thread_task_queue; 359 int nb_threads; 360 361 BdrvChild *data_file; 362 363 bool metadata_preallocation_checked; 364 bool metadata_preallocation; 365 } BDRVQcow2State; 366 367 typedef struct Qcow2COWRegion { 368 /** 369 * Offset of the COW region in bytes from the start of the first cluster 370 * touched by the request. 371 */ 372 unsigned offset; 373 374 /** Number of bytes to copy */ 375 unsigned nb_bytes; 376 } Qcow2COWRegion; 377 378 /** 379 * Describes an in-flight (part of a) write request that writes to clusters 380 * that are not referenced in their L2 table yet. 381 */ 382 typedef struct QCowL2Meta 383 { 384 /** Guest offset of the first newly allocated cluster */ 385 uint64_t offset; 386 387 /** Host offset of the first newly allocated cluster */ 388 uint64_t alloc_offset; 389 390 /** Number of newly allocated clusters */ 391 int nb_clusters; 392 393 /** Do not free the old clusters */ 394 bool keep_old_clusters; 395 396 /** 397 * Requests that overlap with this allocation and wait to be restarted 398 * when the allocating request has completed. 399 */ 400 CoQueue dependent_requests; 401 402 /** 403 * The COW Region between the start of the first allocated cluster and the 404 * area the guest actually writes to. 405 */ 406 Qcow2COWRegion cow_start; 407 408 /** 409 * The COW Region between the area the guest actually writes to and the 410 * end of the last allocated cluster. 411 */ 412 Qcow2COWRegion cow_end; 413 414 /* 415 * Indicates that COW regions are already handled and do not require 416 * any more processing. 417 */ 418 bool skip_cow; 419 420 /** 421 * The I/O vector with the data from the actual guest write request. 422 * If non-NULL, this is meant to be merged together with the data 423 * from @cow_start and @cow_end into one single write operation. 424 */ 425 QEMUIOVector *data_qiov; 426 size_t data_qiov_offset; 427 428 /** Pointer to next L2Meta of the same write request */ 429 struct QCowL2Meta *next; 430 431 QLIST_ENTRY(QCowL2Meta) next_in_flight; 432 } QCowL2Meta; 433 434 typedef enum QCow2ClusterType { 435 QCOW2_CLUSTER_UNALLOCATED, 436 QCOW2_CLUSTER_ZERO_PLAIN, 437 QCOW2_CLUSTER_ZERO_ALLOC, 438 QCOW2_CLUSTER_NORMAL, 439 QCOW2_CLUSTER_COMPRESSED, 440 } QCow2ClusterType; 441 442 typedef enum QCow2MetadataOverlap { 443 QCOW2_OL_MAIN_HEADER_BITNR = 0, 444 QCOW2_OL_ACTIVE_L1_BITNR = 1, 445 QCOW2_OL_ACTIVE_L2_BITNR = 2, 446 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3, 447 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4, 448 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5, 449 QCOW2_OL_INACTIVE_L1_BITNR = 6, 450 QCOW2_OL_INACTIVE_L2_BITNR = 7, 451 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8, 452 453 QCOW2_OL_MAX_BITNR = 9, 454 455 QCOW2_OL_NONE = 0, 456 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR), 457 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR), 458 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR), 459 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR), 460 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR), 461 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR), 462 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR), 463 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv 464 * reads. */ 465 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR), 466 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR), 467 } QCow2MetadataOverlap; 468 469 /* Perform all overlap checks which can be done in constant time */ 470 #define QCOW2_OL_CONSTANT \ 471 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \ 472 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY) 473 474 /* Perform all overlap checks which don't require disk access */ 475 #define QCOW2_OL_CACHED \ 476 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \ 477 QCOW2_OL_INACTIVE_L1) 478 479 /* Perform all overlap checks */ 480 #define QCOW2_OL_ALL \ 481 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2) 482 483 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL 484 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL 485 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL 486 487 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL 488 489 #define INV_OFFSET (-1ULL) 490 491 static inline bool has_data_file(BlockDriverState *bs) 492 { 493 BDRVQcow2State *s = bs->opaque; 494 return (s->data_file != bs->file); 495 } 496 497 static inline bool data_file_is_raw(BlockDriverState *bs) 498 { 499 BDRVQcow2State *s = bs->opaque; 500 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW); 501 } 502 503 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset) 504 { 505 return offset & ~(s->cluster_size - 1); 506 } 507 508 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset) 509 { 510 return offset & (s->cluster_size - 1); 511 } 512 513 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size) 514 { 515 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 516 } 517 518 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size) 519 { 520 int shift = s->cluster_bits + s->l2_bits; 521 return (size + (1ULL << shift) - 1) >> shift; 522 } 523 524 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset) 525 { 526 return offset >> (s->l2_bits + s->cluster_bits); 527 } 528 529 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset) 530 { 531 return (offset >> s->cluster_bits) & (s->l2_size - 1); 532 } 533 534 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset) 535 { 536 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1); 537 } 538 539 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s) 540 { 541 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); 542 } 543 544 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs, 545 uint64_t l2_entry) 546 { 547 if (l2_entry & QCOW_OFLAG_COMPRESSED) { 548 return QCOW2_CLUSTER_COMPRESSED; 549 } else if (l2_entry & QCOW_OFLAG_ZERO) { 550 if (l2_entry & L2E_OFFSET_MASK) { 551 return QCOW2_CLUSTER_ZERO_ALLOC; 552 } 553 return QCOW2_CLUSTER_ZERO_PLAIN; 554 } else if (!(l2_entry & L2E_OFFSET_MASK)) { 555 /* Offset 0 generally means unallocated, but it is ambiguous with 556 * external data files because 0 is a valid offset there. However, all 557 * clusters in external data files always have refcount 1, so we can 558 * rely on QCOW_OFLAG_COPIED to disambiguate. */ 559 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) { 560 return QCOW2_CLUSTER_NORMAL; 561 } else { 562 return QCOW2_CLUSTER_UNALLOCATED; 563 } 564 } else { 565 return QCOW2_CLUSTER_NORMAL; 566 } 567 } 568 569 /* Check whether refcounts are eager or lazy */ 570 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s) 571 { 572 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY); 573 } 574 575 static inline uint64_t l2meta_cow_start(QCowL2Meta *m) 576 { 577 return m->offset + m->cow_start.offset; 578 } 579 580 static inline uint64_t l2meta_cow_end(QCowL2Meta *m) 581 { 582 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes; 583 } 584 585 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2) 586 { 587 return r1 > r2 ? r1 - r2 : r2 - r1; 588 } 589 590 static inline 591 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset) 592 { 593 return offset >> (s->refcount_block_bits + s->cluster_bits); 594 } 595 596 /* qcow2.c functions */ 597 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 598 int refcount_order, bool generous_increase, 599 uint64_t *refblock_count); 600 601 int qcow2_mark_dirty(BlockDriverState *bs); 602 int qcow2_mark_corrupt(BlockDriverState *bs); 603 int qcow2_mark_consistent(BlockDriverState *bs); 604 int qcow2_update_header(BlockDriverState *bs); 605 606 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 607 int64_t size, const char *message_format, ...) 608 GCC_FMT_ATTR(5, 6); 609 610 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 611 uint64_t entries, size_t entry_len, 612 int64_t max_size_bytes, const char *table_name, 613 Error **errp); 614 615 /* qcow2-refcount.c functions */ 616 int qcow2_refcount_init(BlockDriverState *bs); 617 void qcow2_refcount_close(BlockDriverState *bs); 618 619 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, 620 uint64_t *refcount); 621 622 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, 623 uint64_t addend, bool decrease, 624 enum qcow2_discard_type type); 625 626 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset, 627 uint64_t additional_clusters, bool exact_size, 628 int new_refblock_index, 629 uint64_t new_refblock_offset); 630 631 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); 632 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, 633 int64_t nb_clusters); 634 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 635 void qcow2_free_clusters(BlockDriverState *bs, 636 int64_t offset, int64_t size, 637 enum qcow2_discard_type type); 638 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, 639 int nb_clusters, enum qcow2_discard_type type); 640 641 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 642 int64_t l1_table_offset, int l1_size, int addend); 643 644 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs); 645 int coroutine_fn qcow2_write_caches(BlockDriverState *bs); 646 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 647 BdrvCheckMode fix); 648 649 void qcow2_process_discards(BlockDriverState *bs, int ret); 650 651 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, 652 int64_t size); 653 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, 654 int64_t size, bool data_file); 655 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res, 656 void **refcount_table, 657 int64_t *refcount_table_size, 658 int64_t offset, int64_t size); 659 660 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, 661 BlockDriverAmendStatusCB *status_cb, 662 void *cb_opaque, Error **errp); 663 int qcow2_shrink_reftable(BlockDriverState *bs); 664 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size); 665 int qcow2_detect_metadata_preallocation(BlockDriverState *bs); 666 667 /* qcow2-cluster.c functions */ 668 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, 669 bool exact_size); 670 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size); 671 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); 672 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num, 673 uint8_t *buf, int nb_sectors, bool enc, Error **errp); 674 675 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 676 unsigned int *bytes, uint64_t *cluster_offset); 677 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 678 unsigned int *bytes, uint64_t *host_offset, 679 QCowL2Meta **m); 680 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 681 uint64_t offset, 682 int compressed_size, 683 uint64_t *host_offset); 684 685 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 686 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m); 687 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, 688 uint64_t bytes, enum qcow2_discard_type type, 689 bool full_discard); 690 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, 691 uint64_t bytes, int flags); 692 693 int qcow2_expand_zero_clusters(BlockDriverState *bs, 694 BlockDriverAmendStatusCB *status_cb, 695 void *cb_opaque); 696 697 /* qcow2-snapshot.c functions */ 698 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 699 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 700 int qcow2_snapshot_delete(BlockDriverState *bs, 701 const char *snapshot_id, 702 const char *name, 703 Error **errp); 704 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 705 int qcow2_snapshot_load_tmp(BlockDriverState *bs, 706 const char *snapshot_id, 707 const char *name, 708 Error **errp); 709 710 void qcow2_free_snapshots(BlockDriverState *bs); 711 int qcow2_read_snapshots(BlockDriverState *bs); 712 713 /* qcow2-cache.c functions */ 714 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 715 unsigned table_size); 716 int qcow2_cache_destroy(Qcow2Cache *c); 717 718 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 719 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 720 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c); 721 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 722 Qcow2Cache *dependency); 723 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 724 725 void qcow2_cache_clean_unused(Qcow2Cache *c); 726 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c); 727 728 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 729 void **table); 730 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 731 void **table); 732 void qcow2_cache_put(Qcow2Cache *c, void **table); 733 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset); 734 void qcow2_cache_discard(Qcow2Cache *c, void *table); 735 736 /* qcow2-bitmap.c functions */ 737 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 738 void **refcount_table, 739 int64_t *refcount_table_size); 740 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp); 741 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs, 742 Error **errp); 743 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp); 744 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp); 745 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, 746 bool release_stored, Error **errp); 747 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp); 748 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, 749 const char *name, 750 uint32_t granularity, 751 Error **errp); 752 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, 753 const char *name, 754 Error **errp); 755 756 ssize_t coroutine_fn 757 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size, 758 const void *src, size_t src_size); 759 ssize_t coroutine_fn 760 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size, 761 const void *src, size_t src_size); 762 int coroutine_fn 763 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset, 764 uint64_t guest_offset, void *buf, size_t len); 765 int coroutine_fn 766 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset, 767 uint64_t guest_offset, void *buf, size_t len); 768 769 #endif 770