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/block.h"
  29 #include "qemu/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 #define QCOW_CRYPT_LUKS 2
  40
  41 #define QCOW_MAX_CRYPT_CLUSTERS 32
  42 #define QCOW_MAX_SNAPSHOTS 65536
  43
  44 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
  45  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  46 #define QCOW_MAX_REFTABLE_SIZE 0x800000
  47
  48 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
  49  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  50 #define QCOW_MAX_L1_SIZE 0x2000000
  51
  52 /* Allow for an average of 1k per snapshot table entry, should be plenty of
  53  * space for snapshot names and IDs */
  54 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
  55
  56 /* Bitmap header extension constraints */
  57 #define QCOW2_MAX_BITMAPS 65535
  58 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  59
  60 /* indicate that the refcount of the referenced cluster is exactly one. */
  61 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  62 /* indicate that the cluster is compressed (they never have the copied flag) */
  63 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  64 /* The cluster reads as all zeros */
  65 #define QCOW_OFLAG_ZERO (1ULL << 0)
  66
  67 #define MIN_CLUSTER_BITS 9
  68 #define MAX_CLUSTER_BITS 21
  69
  70 /* Must be at least 2 to cover COW */
  71 #define MIN_L2_CACHE_SIZE 2 /* clusters */
  72
  73 /* Must be at least 4 to cover all cases of refcount table growth */
  74 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  75
  76 /* Whichever is more */
  77 #define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
  78 #define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */
  79
  80 /* The refblock cache needs only a fourth of the L2 cache size to cover as many
  81  * clusters */
  82 #define DEFAULT_L2_REFCOUNT_SIZE_RATIO 4
  83
  84 #define DEFAULT_CLUSTER_SIZE 65536
  85
  86
  87 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
  88 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
  89 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
  90 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
  91 #define QCOW2_OPT_OVERLAP "overlap-check"
  92 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
  93 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
  94 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
  95 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
  96 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
  97 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
  98 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
  99 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 100 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 101 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 102 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 103 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 104 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 105
 106 typedef struct QCowHeader {
 107     uint32_t magic;
 108     uint32_t version;
 109     uint64_t backing_file_offset;
 110     uint32_t backing_file_size;
 111     uint32_t cluster_bits;
 112     uint64_t size; /* in bytes */
 113     uint32_t crypt_method;
 114     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 115     uint64_t l1_table_offset;
 116     uint64_t refcount_table_offset;
 117     uint32_t refcount_table_clusters;
 118     uint32_t nb_snapshots;
 119     uint64_t snapshots_offset;
 120
 121     /* The following fields are only valid for version >= 3 */
 122     uint64_t incompatible_features;
 123     uint64_t compatible_features;
 124     uint64_t autoclear_features;
 125
 126     uint32_t refcount_order;
 127     uint32_t header_length;
 128 } QEMU_PACKED QCowHeader;
 129
 130 typedef struct QEMU_PACKED QCowSnapshotHeader {
 131     /* header is 8 byte aligned */
 132     uint64_t l1_table_offset;
 133
 134     uint32_t l1_size;
 135     uint16_t id_str_size;
 136     uint16_t name_size;
 137
 138     uint32_t date_sec;
 139     uint32_t date_nsec;
 140
 141     uint64_t vm_clock_nsec;
 142
 143     uint32_t vm_state_size;
 144     uint32_t extra_data_size; /* for extension */
 145     /* extra data follows */
 146     /* id_str follows */
 147     /* name follows  */
 148 } QCowSnapshotHeader;
 149
 150 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 151     uint64_t vm_state_size_large;
 152     uint64_t disk_size;
 153 } QCowSnapshotExtraData;
 154
 155
 156 typedef struct QCowSnapshot {
 157     uint64_t l1_table_offset;
 158     uint32_t l1_size;
 159     char *id_str;
 160     char *name;
 161     uint64_t disk_size;
 162     uint64_t vm_state_size;
 163     uint32_t date_sec;
 164     uint32_t date_nsec;
 165     uint64_t vm_clock_nsec;
 166 } QCowSnapshot;
 167
 168 struct Qcow2Cache;
 169 typedef struct Qcow2Cache Qcow2Cache;
 170
 171 typedef struct Qcow2CryptoHeaderExtension {
 172     uint64_t offset;
 173     uint64_t length;
 174 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 175
 176 typedef struct Qcow2UnknownHeaderExtension {
 177     uint32_t magic;
 178     uint32_t len;
 179     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 180     uint8_t data[];
 181 } Qcow2UnknownHeaderExtension;
 182
 183 enum {
 184     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 185     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 186     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 187 };
 188
 189 /* Incompatible feature bits */
 190 enum {
 191     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
 192     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
 193     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 194     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 195
 196     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
 197                                  | QCOW2_INCOMPAT_CORRUPT,
 198 };
 199
 200 /* Compatible feature bits */
 201 enum {
 202     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 203     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 204
 205     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 206 };
 207
 208 /* Autoclear feature bits */
 209 enum {
 210     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
 211     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 212
 213     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
 214 };
 215
 216 enum qcow2_discard_type {
 217     QCOW2_DISCARD_NEVER = 0,
 218     QCOW2_DISCARD_ALWAYS,
 219     QCOW2_DISCARD_REQUEST,
 220     QCOW2_DISCARD_SNAPSHOT,
 221     QCOW2_DISCARD_OTHER,
 222     QCOW2_DISCARD_MAX
 223 };
 224
 225 typedef struct Qcow2Feature {
 226     uint8_t type;
 227     uint8_t bit;
 228     char    name[46];
 229 } QEMU_PACKED Qcow2Feature;
 230
 231 typedef struct Qcow2DiscardRegion {
 232     BlockDriverState *bs;
 233     uint64_t offset;
 234     uint64_t bytes;
 235     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 236 } Qcow2DiscardRegion;
 237
 238 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 239                                       uint64_t index);
 240 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 241                                   uint64_t index, uint64_t value);
 242
 243 typedef struct Qcow2BitmapHeaderExt {
 244     uint32_t nb_bitmaps;
 245     uint32_t reserved32;
 246     uint64_t bitmap_directory_size;
 247     uint64_t bitmap_directory_offset;
 248 } QEMU_PACKED Qcow2BitmapHeaderExt;
 249
 250 typedef struct BDRVQcow2State {
 251     int cluster_bits;
 252     int cluster_size;
 253     int cluster_sectors;
 254     int l2_bits;
 255     int l2_size;
 256     int l1_size;
 257     int l1_vm_state_index;
 258     int refcount_block_bits;
 259     int refcount_block_size;
 260     int csize_shift;
 261     int csize_mask;
 262     uint64_t cluster_offset_mask;
 263     uint64_t l1_table_offset;
 264     uint64_t *l1_table;
 265
 266     Qcow2Cache* l2_table_cache;
 267     Qcow2Cache* refcount_block_cache;
 268     QEMUTimer *cache_clean_timer;
 269     unsigned cache_clean_interval;
 270
 271     uint8_t *cluster_cache;
 272     uint8_t *cluster_data;
 273     uint64_t cluster_cache_offset;
 274     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
 275
 276     uint64_t *refcount_table;
 277     uint64_t refcount_table_offset;
 278     uint32_t refcount_table_size;
 279     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 280     uint64_t free_cluster_index;
 281     uint64_t free_byte_offset;
 282
 283     CoMutex lock;
 284
 285     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 286     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 287     QCryptoBlock *crypto; /* Disk encryption format driver */
 288     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 289                                    for encryption initialization vector tweak */
 290     uint32_t crypt_method_header;
 291     uint64_t snapshots_offset;
 292     int snapshots_size;
 293     unsigned int nb_snapshots;
 294     QCowSnapshot *snapshots;
 295
 296     uint32_t nb_bitmaps;
 297     uint64_t bitmap_directory_size;
 298     uint64_t bitmap_directory_offset;
 299
 300     int flags;
 301     int qcow_version;
 302     bool use_lazy_refcounts;
 303     int refcount_order;
 304     int refcount_bits;
 305     uint64_t refcount_max;
 306
 307     Qcow2GetRefcountFunc *get_refcount;
 308     Qcow2SetRefcountFunc *set_refcount;
 309
 310     bool discard_passthrough[QCOW2_DISCARD_MAX];
 311
 312     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 313     bool signaled_corruption;
 314
 315     uint64_t incompatible_features;
 316     uint64_t compatible_features;
 317     uint64_t autoclear_features;
 318
 319     size_t unknown_header_fields_size;
 320     void* unknown_header_fields;
 321     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 322     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 323     bool cache_discards;
 324
 325     /* Backing file path and format as stored in the image (this is not the
 326      * effective path/format, which may be the result of a runtime option
 327      * override) */
 328     char *image_backing_file;
 329     char *image_backing_format;
 330 } BDRVQcow2State;
 331
 332 typedef struct Qcow2COWRegion {
 333     /**
 334      * Offset of the COW region in bytes from the start of the first cluster
 335      * touched by the request.
 336      */
 337     unsigned    offset;
 338
 339     /** Number of bytes to copy */
 340     unsigned    nb_bytes;
 341 } Qcow2COWRegion;
 342
 343 /**
 344  * Describes an in-flight (part of a) write request that writes to clusters
 345  * that are not referenced in their L2 table yet.
 346  */
 347 typedef struct QCowL2Meta
 348 {
 349     /** Guest offset of the first newly allocated cluster */
 350     uint64_t offset;
 351
 352     /** Host offset of the first newly allocated cluster */
 353     uint64_t alloc_offset;
 354
 355     /** Number of newly allocated clusters */
 356     int nb_clusters;
 357
 358     /** Do not free the old clusters */
 359     bool keep_old_clusters;
 360
 361     /**
 362      * Requests that overlap with this allocation and wait to be restarted
 363      * when the allocating request has completed.
 364      */
 365     CoQueue dependent_requests;
 366
 367     /**
 368      * The COW Region between the start of the first allocated cluster and the
 369      * area the guest actually writes to.
 370      */
 371     Qcow2COWRegion cow_start;
 372
 373     /**
 374      * The COW Region between the area the guest actually writes to and the
 375      * end of the last allocated cluster.
 376      */
 377     Qcow2COWRegion cow_end;
 378
 379     /**
 380      * The I/O vector with the data from the actual guest write request.
 381      * If non-NULL, this is meant to be merged together with the data
 382      * from @cow_start and @cow_end into one single write operation.
 383      */
 384     QEMUIOVector *data_qiov;
 385
 386     /** Pointer to next L2Meta of the same write request */
 387     struct QCowL2Meta *next;
 388
 389     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 390 } QCowL2Meta;
 391
 392 typedef enum QCow2ClusterType {
 393     QCOW2_CLUSTER_UNALLOCATED,
 394     QCOW2_CLUSTER_ZERO_PLAIN,
 395     QCOW2_CLUSTER_ZERO_ALLOC,
 396     QCOW2_CLUSTER_NORMAL,
 397     QCOW2_CLUSTER_COMPRESSED,
 398 } QCow2ClusterType;
 399
 400 typedef enum QCow2MetadataOverlap {
 401     QCOW2_OL_MAIN_HEADER_BITNR    = 0,
 402     QCOW2_OL_ACTIVE_L1_BITNR      = 1,
 403     QCOW2_OL_ACTIVE_L2_BITNR      = 2,
 404     QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
 405     QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
 406     QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
 407     QCOW2_OL_INACTIVE_L1_BITNR    = 6,
 408     QCOW2_OL_INACTIVE_L2_BITNR    = 7,
 409
 410     QCOW2_OL_MAX_BITNR            = 8,
 411
 412     QCOW2_OL_NONE           = 0,
 413     QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 414     QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 415     QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 416     QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 417     QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 418     QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 419     QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 420     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 421      * reads. */
 422     QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 423 } QCow2MetadataOverlap;
 424
 425 /* Perform all overlap checks which can be done in constant time */
 426 #define QCOW2_OL_CONSTANT \
 427     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 428      QCOW2_OL_SNAPSHOT_TABLE)
 429
 430 /* Perform all overlap checks which don't require disk access */
 431 #define QCOW2_OL_CACHED \
 432     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 433      QCOW2_OL_INACTIVE_L1)
 434
 435 /* Perform all overlap checks */
 436 #define QCOW2_OL_ALL \
 437     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 438
 439 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 440 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 441 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 442
 443 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 444
 445 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 446 {
 447     return offset & ~(s->cluster_size - 1);
 448 }
 449
 450 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 451 {
 452     return offset & (s->cluster_size - 1);
 453 }
 454
 455 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 456 {
 457     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 458 }
 459
 460 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 461 {
 462     int shift = s->cluster_bits + s->l2_bits;
 463     return (size + (1ULL << shift) - 1) >> shift;
 464 }
 465
 466 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 467 {
 468     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 469 }
 470
 471 static inline int64_t align_offset(int64_t offset, int n)
 472 {
 473     offset = (offset + n - 1) & ~(n - 1);
 474     return offset;
 475 }
 476
 477 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 478 {
 479     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 480 }
 481
 482 static inline uint64_t qcow2_max_refcount_clusters(BDRVQcow2State *s)
 483 {
 484     return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
 485 }
 486
 487 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
 488 {
 489     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 490         return QCOW2_CLUSTER_COMPRESSED;
 491     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 492         if (l2_entry & L2E_OFFSET_MASK) {
 493             return QCOW2_CLUSTER_ZERO_ALLOC;
 494         }
 495         return QCOW2_CLUSTER_ZERO_PLAIN;
 496     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 497         return QCOW2_CLUSTER_UNALLOCATED;
 498     } else {
 499         return QCOW2_CLUSTER_NORMAL;
 500     }
 501 }
 502
 503 /* Check whether refcounts are eager or lazy */
 504 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 505 {
 506     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 507 }
 508
 509 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 510 {
 511     return m->offset + m->cow_start.offset;
 512 }
 513
 514 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 515 {
 516     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 517 }
 518
 519 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 520 {
 521     return r1 > r2 ? r1 - r2 : r2 - r1;
 522 }
 523
 524 static inline
 525 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 526 {
 527     return offset >> (s->refcount_block_bits + s->cluster_bits);
 528 }
 529
 530 static inline uint64_t get_refblock_offset(BDRVQcow2State *s, uint64_t offset)
 531 {
 532     uint32_t index = offset_to_reftable_index(s, offset);
 533     return s->refcount_table[index] & REFT_OFFSET_MASK;
 534 }
 535
 536 /* qcow2.c functions */
 537 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
 538                   int64_t sector_num, int nb_sectors);
 539
 540 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 541                                      int refcount_order, bool generous_increase,
 542                                      uint64_t *refblock_count);
 543
 544 int qcow2_mark_dirty(BlockDriverState *bs);
 545 int qcow2_mark_corrupt(BlockDriverState *bs);
 546 int qcow2_mark_consistent(BlockDriverState *bs);
 547 int qcow2_update_header(BlockDriverState *bs);
 548
 549 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 550                              int64_t size, const char *message_format, ...)
 551                              GCC_FMT_ATTR(5, 6);
 552
 553 /* qcow2-refcount.c functions */
 554 int qcow2_refcount_init(BlockDriverState *bs);
 555 void qcow2_refcount_close(BlockDriverState *bs);
 556
 557 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 558                        uint64_t *refcount);
 559
 560 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 561                                   uint64_t addend, bool decrease,
 562                                   enum qcow2_discard_type type);
 563
 564 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 565                             uint64_t additional_clusters, bool exact_size,
 566                             int new_refblock_index,
 567                             uint64_t new_refblock_offset);
 568
 569 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 570 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 571                                 int64_t nb_clusters);
 572 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 573 void qcow2_free_clusters(BlockDriverState *bs,
 574                           int64_t offset, int64_t size,
 575                           enum qcow2_discard_type type);
 576 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 577                              int nb_clusters, enum qcow2_discard_type type);
 578
 579 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 580     int64_t l1_table_offset, int l1_size, int addend);
 581
 582 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 583                           BdrvCheckMode fix);
 584
 585 void qcow2_process_discards(BlockDriverState *bs, int ret);
 586
 587 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 588                                  int64_t size);
 589 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 590                                   int64_t size);
 591 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 592                              void **refcount_table,
 593                              int64_t *refcount_table_size,
 594                              int64_t offset, int64_t size);
 595
 596 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 597                                 BlockDriverAmendStatusCB *status_cb,
 598                                 void *cb_opaque, Error **errp);
 599 int qcow2_shrink_reftable(BlockDriverState *bs);
 600 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 601
 602 /* qcow2-cluster.c functions */
 603 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 604                         bool exact_size);
 605 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 606 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 607 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 608 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 609                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 610
 611 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 612                              unsigned int *bytes, uint64_t *cluster_offset);
 613 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 614                                unsigned int *bytes, uint64_t *host_offset,
 615                                QCowL2Meta **m);
 616 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 617                                          uint64_t offset,
 618                                          int compressed_size);
 619
 620 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 621 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 622                           uint64_t bytes, enum qcow2_discard_type type,
 623                           bool full_discard);
 624 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 625                           uint64_t bytes, int flags);
 626
 627 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 628                                BlockDriverAmendStatusCB *status_cb,
 629                                void *cb_opaque);
 630
 631 /* qcow2-snapshot.c functions */
 632 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 633 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 634 int qcow2_snapshot_delete(BlockDriverState *bs,
 635                           const char *snapshot_id,
 636                           const char *name,
 637                           Error **errp);
 638 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 639 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 640                             const char *snapshot_id,
 641                             const char *name,
 642                             Error **errp);
 643
 644 void qcow2_free_snapshots(BlockDriverState *bs);
 645 int qcow2_read_snapshots(BlockDriverState *bs);
 646
 647 /* qcow2-cache.c functions */
 648 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
 649 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
 650
 651 void qcow2_cache_entry_mark_dirty(BlockDriverState *bs, Qcow2Cache *c,
 652      void *table);
 653 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 654 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 655 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 656     Qcow2Cache *dependency);
 657 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 658
 659 void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c);
 660 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 661
 662 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 663     void **table);
 664 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 665     void **table);
 666 void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table);
 667 void *qcow2_cache_is_table_offset(BlockDriverState *bs, Qcow2Cache *c,
 668                                   uint64_t offset);
 669 void qcow2_cache_discard(BlockDriverState *bs, Qcow2Cache *c, void *table);
 670
 671 /* qcow2-bitmap.c functions */
 672 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 673                                   void **refcount_table,
 674                                   int64_t *refcount_table_size);
 675 bool qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 676 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 677 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 678 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 679 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 680                                       const char *name,
 681                                       uint32_t granularity,
 682                                       Error **errp);
 683 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 684                                           const char *name,
 685                                           Error **errp);
 686
 687 #endif