block/qcow2.h

   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 /* Must be at least 2 to cover COW */
  66 #define MIN_L2_CACHE_SIZE 2 /* clusters */
  67
  68 /* Must be at least 4 to cover all cases of refcount table growth */
  69 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  70
  71 /* Whichever is more */
  72 #define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
  73 #define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */
  74
  75 /* The refblock cache needs only a fourth of the L2 cache size to cover as many
  76  * clusters */
  77 #define DEFAULT_L2_REFCOUNT_SIZE_RATIO 4
  78
  79 #define DEFAULT_CLUSTER_SIZE 65536
  80
  81
  82 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
  83 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
  84 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
  85 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
  86 #define QCOW2_OPT_OVERLAP "overlap-check"
  87 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
  88 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
  89 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
  90 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
  91 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
  92 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
  93 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
  94 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
  95 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
  96 #define QCOW2_OPT_CACHE_SIZE "cache-size"
  97 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
  98 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
  99
 100 typedef struct QCowHeader {
 101     uint32_t magic;
 102     uint32_t version;
 103     uint64_t backing_file_offset;
 104     uint32_t backing_file_size;
 105     uint32_t cluster_bits;
 106     uint64_t size; /* in bytes */
 107     uint32_t crypt_method;
 108     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 109     uint64_t l1_table_offset;
 110     uint64_t refcount_table_offset;
 111     uint32_t refcount_table_clusters;
 112     uint32_t nb_snapshots;
 113     uint64_t snapshots_offset;
 114
 115     /* The following fields are only valid for version >= 3 */
 116     uint64_t incompatible_features;
 117     uint64_t compatible_features;
 118     uint64_t autoclear_features;
 119
 120     uint32_t refcount_order;
 121     uint32_t header_length;
 122 } QEMU_PACKED QCowHeader;
 123
 124 typedef struct QEMU_PACKED QCowSnapshotHeader {
 125     /* header is 8 byte aligned */
 126     uint64_t l1_table_offset;
 127
 128     uint32_t l1_size;
 129     uint16_t id_str_size;
 130     uint16_t name_size;
 131
 132     uint32_t date_sec;
 133     uint32_t date_nsec;
 134
 135     uint64_t vm_clock_nsec;
 136
 137     uint32_t vm_state_size;
 138     uint32_t extra_data_size; /* for extension */
 139     /* extra data follows */
 140     /* id_str follows */
 141     /* name follows  */
 142 } QCowSnapshotHeader;
 143
 144 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 145     uint64_t vm_state_size_large;
 146     uint64_t disk_size;
 147 } QCowSnapshotExtraData;
 148
 149
 150 typedef struct QCowSnapshot {
 151     uint64_t l1_table_offset;
 152     uint32_t l1_size;
 153     char *id_str;
 154     char *name;
 155     uint64_t disk_size;
 156     uint64_t vm_state_size;
 157     uint32_t date_sec;
 158     uint32_t date_nsec;
 159     uint64_t vm_clock_nsec;
 160 } QCowSnapshot;
 161
 162 struct Qcow2Cache;
 163 typedef struct Qcow2Cache Qcow2Cache;
 164
 165 typedef struct Qcow2UnknownHeaderExtension {
 166     uint32_t magic;
 167     uint32_t len;
 168     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 169     uint8_t data[];
 170 } Qcow2UnknownHeaderExtension;
 171
 172 enum {
 173     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 174     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 175     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 176 };
 177
 178 /* Incompatible feature bits */
 179 enum {
 180     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
 181     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
 182     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 183     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 184
 185     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
 186                                  | QCOW2_INCOMPAT_CORRUPT,
 187 };
 188
 189 /* Compatible feature bits */
 190 enum {
 191     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 192     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 193
 194     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 195 };
 196
 197 enum qcow2_discard_type {
 198     QCOW2_DISCARD_NEVER = 0,
 199     QCOW2_DISCARD_ALWAYS,
 200     QCOW2_DISCARD_REQUEST,
 201     QCOW2_DISCARD_SNAPSHOT,
 202     QCOW2_DISCARD_OTHER,
 203     QCOW2_DISCARD_MAX
 204 };
 205
 206 typedef struct Qcow2Feature {
 207     uint8_t type;
 208     uint8_t bit;
 209     char    name[46];
 210 } QEMU_PACKED Qcow2Feature;
 211
 212 typedef struct Qcow2DiscardRegion {
 213     BlockDriverState *bs;
 214     uint64_t offset;
 215     uint64_t bytes;
 216     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 217 } Qcow2DiscardRegion;
 218
 219 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 220                                       uint64_t index);
 221 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 222                                   uint64_t index, uint64_t value);
 223
 224 typedef struct BDRVQcowState {
 225     int cluster_bits;
 226     int cluster_size;
 227     int cluster_sectors;
 228     int l2_bits;
 229     int l2_size;
 230     int l1_size;
 231     int l1_vm_state_index;
 232     int refcount_block_bits;
 233     int refcount_block_size;
 234     int csize_shift;
 235     int csize_mask;
 236     uint64_t cluster_offset_mask;
 237     uint64_t l1_table_offset;
 238     uint64_t *l1_table;
 239
 240     Qcow2Cache* l2_table_cache;
 241     Qcow2Cache* refcount_block_cache;
 242
 243     uint8_t *cluster_cache;
 244     uint8_t *cluster_data;
 245     uint64_t cluster_cache_offset;
 246     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
 247
 248     uint64_t *refcount_table;
 249     uint64_t refcount_table_offset;
 250     uint32_t refcount_table_size;
 251     uint64_t free_cluster_index;
 252     uint64_t free_byte_offset;
 253
 254     CoMutex lock;
 255
 256     uint32_t crypt_method; /* current crypt method, 0 if no key yet */
 257     uint32_t crypt_method_header;
 258     AES_KEY aes_encrypt_key;
 259     AES_KEY aes_decrypt_key;
 260     uint64_t snapshots_offset;
 261     int snapshots_size;
 262     unsigned int nb_snapshots;
 263     QCowSnapshot *snapshots;
 264
 265     int flags;
 266     int qcow_version;
 267     bool use_lazy_refcounts;
 268     int refcount_order;
 269     int refcount_bits;
 270     uint64_t refcount_max;
 271
 272     Qcow2GetRefcountFunc *get_refcount;
 273     Qcow2SetRefcountFunc *set_refcount;
 274
 275     bool discard_passthrough[QCOW2_DISCARD_MAX];
 276
 277     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 278     bool signaled_corruption;
 279
 280     uint64_t incompatible_features;
 281     uint64_t compatible_features;
 282     uint64_t autoclear_features;
 283
 284     size_t unknown_header_fields_size;
 285     void* unknown_header_fields;
 286     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 287     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 288     bool cache_discards;
 289
 290     /* Backing file path and format as stored in the image (this is not the
 291      * effective path/format, which may be the result of a runtime option
 292      * override) */
 293     char *image_backing_file;
 294     char *image_backing_format;
 295 } BDRVQcowState;
 296
 297 struct QCowAIOCB;
 298
 299 typedef struct Qcow2COWRegion {
 300     /**
 301      * Offset of the COW region in bytes from the start of the first cluster
 302      * touched by the request.
 303      */
 304     uint64_t    offset;
 305
 306     /** Number of sectors to copy */
 307     int         nb_sectors;
 308 } Qcow2COWRegion;
 309
 310 /**
 311  * Describes an in-flight (part of a) write request that writes to clusters
 312  * that are not referenced in their L2 table yet.
 313  */
 314 typedef struct QCowL2Meta
 315 {
 316     /** Guest offset of the first newly allocated cluster */
 317     uint64_t offset;
 318
 319     /** Host offset of the first newly allocated cluster */
 320     uint64_t alloc_offset;
 321
 322     /**
 323      * Number of sectors from the start of the first allocated cluster to
 324      * the end of the (possibly shortened) request
 325      */
 326     int nb_available;
 327
 328     /** Number of newly allocated clusters */
 329     int nb_clusters;
 330
 331     /**
 332      * Requests that overlap with this allocation and wait to be restarted
 333      * when the allocating request has completed.
 334      */
 335     CoQueue dependent_requests;
 336
 337     /**
 338      * The COW Region between the start of the first allocated cluster and the
 339      * area the guest actually writes to.
 340      */
 341     Qcow2COWRegion cow_start;
 342
 343     /**
 344      * The COW Region between the area the guest actually writes to and the
 345      * end of the last allocated cluster.
 346      */
 347     Qcow2COWRegion cow_end;
 348
 349     /** Pointer to next L2Meta of the same write request */
 350     struct QCowL2Meta *next;
 351
 352     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 353 } QCowL2Meta;
 354
 355 enum {
 356     QCOW2_CLUSTER_UNALLOCATED,
 357     QCOW2_CLUSTER_NORMAL,
 358     QCOW2_CLUSTER_COMPRESSED,
 359     QCOW2_CLUSTER_ZERO
 360 };
 361
 362 typedef enum QCow2MetadataOverlap {
 363     QCOW2_OL_MAIN_HEADER_BITNR    = 0,
 364     QCOW2_OL_ACTIVE_L1_BITNR      = 1,
 365     QCOW2_OL_ACTIVE_L2_BITNR      = 2,
 366     QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
 367     QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
 368     QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
 369     QCOW2_OL_INACTIVE_L1_BITNR    = 6,
 370     QCOW2_OL_INACTIVE_L2_BITNR    = 7,
 371
 372     QCOW2_OL_MAX_BITNR            = 8,
 373
 374     QCOW2_OL_NONE           = 0,
 375     QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 376     QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 377     QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 378     QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 379     QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 380     QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 381     QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 382     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 383      * reads. */
 384     QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 385 } QCow2MetadataOverlap;
 386
 387 /* Perform all overlap checks which can be done in constant time */
 388 #define QCOW2_OL_CONSTANT \
 389     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 390      QCOW2_OL_SNAPSHOT_TABLE)
 391
 392 /* Perform all overlap checks which don't require disk access */
 393 #define QCOW2_OL_CACHED \
 394     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 395      QCOW2_OL_INACTIVE_L1)
 396
 397 /* Perform all overlap checks */
 398 #define QCOW2_OL_ALL \
 399     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 400
 401 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 402 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 403 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 404
 405 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 406
 407 static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
 408 {
 409     return offset & ~(s->cluster_size - 1);
 410 }
 411
 412 static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
 413 {
 414     return offset & (s->cluster_size - 1);
 415 }
 416
 417 static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
 418 {
 419     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 420 }
 421
 422 static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size)
 423 {
 424     int shift = s->cluster_bits + s->l2_bits;
 425     return (size + (1ULL << shift) - 1) >> shift;
 426 }
 427
 428 static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
 429 {
 430     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 431 }
 432
 433 static inline int64_t align_offset(int64_t offset, int n)
 434 {
 435     offset = (offset + n - 1) & ~(n - 1);
 436     return offset;
 437 }
 438
 439 static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s)
 440 {
 441     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 442 }
 443
 444 static inline uint64_t qcow2_max_refcount_clusters(BDRVQcowState *s)
 445 {
 446     return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
 447 }
 448
 449 static inline int qcow2_get_cluster_type(uint64_t l2_entry)
 450 {
 451     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 452         return QCOW2_CLUSTER_COMPRESSED;
 453     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 454         return QCOW2_CLUSTER_ZERO;
 455     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 456         return QCOW2_CLUSTER_UNALLOCATED;
 457     } else {
 458         return QCOW2_CLUSTER_NORMAL;
 459     }
 460 }
 461
 462 /* Check whether refcounts are eager or lazy */
 463 static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
 464 {
 465     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 466 }
 467
 468 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 469 {
 470     return m->offset + m->cow_start.offset;
 471 }
 472
 473 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 474 {
 475     return m->offset + m->cow_end.offset
 476         + (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
 477 }
 478
 479 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 480 {
 481     return r1 > r2 ? r1 - r2 : r2 - r1;
 482 }
 483
 484 // FIXME Need qcow2_ prefix to global functions
 485
 486 /* qcow2.c functions */
 487 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
 488                   int64_t sector_num, int nb_sectors);
 489
 490 int qcow2_mark_dirty(BlockDriverState *bs);
 491 int qcow2_mark_corrupt(BlockDriverState *bs);
 492 int qcow2_mark_consistent(BlockDriverState *bs);
 493 int qcow2_update_header(BlockDriverState *bs);
 494
 495 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 496                              int64_t size, const char *message_format, ...)
 497                              GCC_FMT_ATTR(5, 6);
 498
 499 /* qcow2-refcount.c functions */
 500 int qcow2_refcount_init(BlockDriverState *bs);
 501 void qcow2_refcount_close(BlockDriverState *bs);
 502
 503 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 504                        uint64_t *refcount);
 505
 506 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 507                                   uint64_t addend, bool decrease,
 508                                   enum qcow2_discard_type type);
 509
 510 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 511 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 512     int nb_clusters);
 513 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 514 void qcow2_free_clusters(BlockDriverState *bs,
 515                           int64_t offset, int64_t size,
 516                           enum qcow2_discard_type type);
 517 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 518                              int nb_clusters, enum qcow2_discard_type type);
 519
 520 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 521     int64_t l1_table_offset, int l1_size, int addend);
 522
 523 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 524                           BdrvCheckMode fix);
 525
 526 void qcow2_process_discards(BlockDriverState *bs, int ret);
 527
 528 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 529                                  int64_t size);
 530 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 531                                   int64_t size);
 532
 533 /* qcow2-cluster.c functions */
 534 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 535                         bool exact_size);
 536 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 537 void qcow2_l2_cache_reset(BlockDriverState *bs);
 538 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 539 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 540                      uint8_t *out_buf, const uint8_t *in_buf,
 541                      int nb_sectors, int enc,
 542                      const AES_KEY *key);
 543
 544 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 545     int *num, uint64_t *cluster_offset);
 546 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 547     int *num, uint64_t *host_offset, QCowL2Meta **m);
 548 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 549                                          uint64_t offset,
 550                                          int compressed_size);
 551
 552 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 553 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
 554     int nb_sectors, enum qcow2_discard_type type, bool full_discard);
 555 int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
 556
 557 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 558                                BlockDriverAmendStatusCB *status_cb);
 559
 560 /* qcow2-snapshot.c functions */
 561 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 562 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 563 int qcow2_snapshot_delete(BlockDriverState *bs,
 564                           const char *snapshot_id,
 565                           const char *name,
 566                           Error **errp);
 567 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 568 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 569                             const char *snapshot_id,
 570                             const char *name,
 571                             Error **errp);
 572
 573 void qcow2_free_snapshots(BlockDriverState *bs);
 574 int qcow2_read_snapshots(BlockDriverState *bs);
 575
 576 /* qcow2-cache.c functions */
 577 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
 578 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
 579
 580 void qcow2_cache_entry_mark_dirty(BlockDriverState *bs, Qcow2Cache *c,
 581      void *table);
 582 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 583 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 584     Qcow2Cache *dependency);
 585 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 586
 587 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 588
 589 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 590     void **table);
 591 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 592     void **table);
 593 void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table);
 594
 595 #endif