qemu/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 "crypto/cipher.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     QCryptoCipher *cipher; /* current cipher, NULL if no key yet */
 257     uint32_t crypt_method_header;
 258     uint64_t snapshots_offset;
 259     int snapshots_size;
 260     unsigned int nb_snapshots;
 261     QCowSnapshot *snapshots;
 262
 263     int flags;
 264     int qcow_version;
 265     bool use_lazy_refcounts;
 266     int refcount_order;
 267     int refcount_bits;
 268     uint64_t refcount_max;
 269
 270     Qcow2GetRefcountFunc *get_refcount;
 271     Qcow2SetRefcountFunc *set_refcount;
 272
 273     bool discard_passthrough[QCOW2_DISCARD_MAX];
 274
 275     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 276     bool signaled_corruption;
 277
 278     uint64_t incompatible_features;
 279     uint64_t compatible_features;
 280     uint64_t autoclear_features;
 281
 282     size_t unknown_header_fields_size;
 283     void* unknown_header_fields;
 284     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 285     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 286     bool cache_discards;
 287
 288     /* Backing file path and format as stored in the image (this is not the
 289      * effective path/format, which may be the result of a runtime option
 290      * override) */
 291     char *image_backing_file;
 292     char *image_backing_format;
 293 } BDRVQcowState;
 294
 295 struct QCowAIOCB;
 296
 297 typedef struct Qcow2COWRegion {
 298     /**
 299      * Offset of the COW region in bytes from the start of the first cluster
 300      * touched by the request.
 301      */
 302     uint64_t    offset;
 303
 304     /** Number of sectors to copy */
 305     int         nb_sectors;
 306 } Qcow2COWRegion;
 307
 308 /**
 309  * Describes an in-flight (part of a) write request that writes to clusters
 310  * that are not referenced in their L2 table yet.
 311  */
 312 typedef struct QCowL2Meta
 313 {
 314     /** Guest offset of the first newly allocated cluster */
 315     uint64_t offset;
 316
 317     /** Host offset of the first newly allocated cluster */
 318     uint64_t alloc_offset;
 319
 320     /**
 321      * Number of sectors from the start of the first allocated cluster to
 322      * the end of the (possibly shortened) request
 323      */
 324     int nb_available;
 325
 326     /** Number of newly allocated clusters */
 327     int nb_clusters;
 328
 329     /**
 330      * Requests that overlap with this allocation and wait to be restarted
 331      * when the allocating request has completed.
 332      */
 333     CoQueue dependent_requests;
 334
 335     /**
 336      * The COW Region between the start of the first allocated cluster and the
 337      * area the guest actually writes to.
 338      */
 339     Qcow2COWRegion cow_start;
 340
 341     /**
 342      * The COW Region between the area the guest actually writes to and the
 343      * end of the last allocated cluster.
 344      */
 345     Qcow2COWRegion cow_end;
 346
 347     /** Pointer to next L2Meta of the same write request */
 348     struct QCowL2Meta *next;
 349
 350     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 351 } QCowL2Meta;
 352
 353 enum {
 354     QCOW2_CLUSTER_UNALLOCATED,
 355     QCOW2_CLUSTER_NORMAL,
 356     QCOW2_CLUSTER_COMPRESSED,
 357     QCOW2_CLUSTER_ZERO
 358 };
 359
 360 typedef enum QCow2MetadataOverlap {
 361     QCOW2_OL_MAIN_HEADER_BITNR    = 0,
 362     QCOW2_OL_ACTIVE_L1_BITNR      = 1,
 363     QCOW2_OL_ACTIVE_L2_BITNR      = 2,
 364     QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
 365     QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
 366     QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
 367     QCOW2_OL_INACTIVE_L1_BITNR    = 6,
 368     QCOW2_OL_INACTIVE_L2_BITNR    = 7,
 369
 370     QCOW2_OL_MAX_BITNR            = 8,
 371
 372     QCOW2_OL_NONE           = 0,
 373     QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 374     QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 375     QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 376     QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 377     QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 378     QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 379     QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 380     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 381      * reads. */
 382     QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 383 } QCow2MetadataOverlap;
 384
 385 /* Perform all overlap checks which can be done in constant time */
 386 #define QCOW2_OL_CONSTANT \
 387     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 388      QCOW2_OL_SNAPSHOT_TABLE)
 389
 390 /* Perform all overlap checks which don't require disk access */
 391 #define QCOW2_OL_CACHED \
 392     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 393      QCOW2_OL_INACTIVE_L1)
 394
 395 /* Perform all overlap checks */
 396 #define QCOW2_OL_ALL \
 397     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 398
 399 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 400 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 401 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 402
 403 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 404
 405 static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
 406 {
 407     return offset & ~(s->cluster_size - 1);
 408 }
 409
 410 static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
 411 {
 412     return offset & (s->cluster_size - 1);
 413 }
 414
 415 static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
 416 {
 417     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 418 }
 419
 420 static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size)
 421 {
 422     int shift = s->cluster_bits + s->l2_bits;
 423     return (size + (1ULL << shift) - 1) >> shift;
 424 }
 425
 426 static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
 427 {
 428     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 429 }
 430
 431 static inline int64_t align_offset(int64_t offset, int n)
 432 {
 433     offset = (offset + n - 1) & ~(n - 1);
 434     return offset;
 435 }
 436
 437 static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s)
 438 {
 439     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 440 }
 441
 442 static inline uint64_t qcow2_max_refcount_clusters(BDRVQcowState *s)
 443 {
 444     return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
 445 }
 446
 447 static inline int qcow2_get_cluster_type(uint64_t l2_entry)
 448 {
 449     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 450         return QCOW2_CLUSTER_COMPRESSED;
 451     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 452         return QCOW2_CLUSTER_ZERO;
 453     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 454         return QCOW2_CLUSTER_UNALLOCATED;
 455     } else {
 456         return QCOW2_CLUSTER_NORMAL;
 457     }
 458 }
 459
 460 /* Check whether refcounts are eager or lazy */
 461 static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
 462 {
 463     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 464 }
 465
 466 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 467 {
 468     return m->offset + m->cow_start.offset;
 469 }
 470
 471 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 472 {
 473     return m->offset + m->cow_end.offset
 474         + (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
 475 }
 476
 477 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 478 {
 479     return r1 > r2 ? r1 - r2 : r2 - r1;
 480 }
 481
 482 // FIXME Need qcow2_ prefix to global functions
 483
 484 /* qcow2.c functions */
 485 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
 486                   int64_t sector_num, int nb_sectors);
 487
 488 int qcow2_mark_dirty(BlockDriverState *bs);
 489 int qcow2_mark_corrupt(BlockDriverState *bs);
 490 int qcow2_mark_consistent(BlockDriverState *bs);
 491 int qcow2_update_header(BlockDriverState *bs);
 492
 493 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 494                              int64_t size, const char *message_format, ...)
 495                              GCC_FMT_ATTR(5, 6);
 496
 497 /* qcow2-refcount.c functions */
 498 int qcow2_refcount_init(BlockDriverState *bs);
 499 void qcow2_refcount_close(BlockDriverState *bs);
 500
 501 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 502                        uint64_t *refcount);
 503
 504 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 505                                   uint64_t addend, bool decrease,
 506                                   enum qcow2_discard_type type);
 507
 508 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 509 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 510     int nb_clusters);
 511 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 512 void qcow2_free_clusters(BlockDriverState *bs,
 513                           int64_t offset, int64_t size,
 514                           enum qcow2_discard_type type);
 515 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 516                              int nb_clusters, enum qcow2_discard_type type);
 517
 518 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 519     int64_t l1_table_offset, int l1_size, int addend);
 520
 521 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 522                           BdrvCheckMode fix);
 523
 524 void qcow2_process_discards(BlockDriverState *bs, int ret);
 525
 526 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 527                                  int64_t size);
 528 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 529                                   int64_t size);
 530
 531 /* qcow2-cluster.c functions */
 532 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 533                         bool exact_size);
 534 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 535 void qcow2_l2_cache_reset(BlockDriverState *bs);
 536 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 537 int qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 538                           uint8_t *out_buf, const uint8_t *in_buf,
 539                           int nb_sectors, bool enc, Error **errp);
 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(BlockDriverState *bs, Qcow2Cache *c,
 578      void *table);
 579 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 580 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 581     Qcow2Cache *dependency);
 582 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 583
 584 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 585
 586 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 587     void **table);
 588 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 589     void **table);
 590 void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table);
 591
 592 #endif