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 #include "qemu/units.h"
  31
  32 //#define DEBUG_ALLOC
  33 //#define DEBUG_ALLOC2
  34 //#define DEBUG_EXT
  35
  36 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
  37
  38 #define QCOW_CRYPT_NONE 0
  39 #define QCOW_CRYPT_AES  1
  40 #define QCOW_CRYPT_LUKS 2
  41
  42 #define QCOW_MAX_CRYPT_CLUSTERS 32
  43 #define QCOW_MAX_SNAPSHOTS 65536
  44
  45 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
  46  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  47 #define QCOW_MAX_REFTABLE_SIZE S_8MiB
  48
  49 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
  50  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  51 #define QCOW_MAX_L1_SIZE S_32MiB
  52
  53 /* Allow for an average of 1k per snapshot table entry, should be plenty of
  54  * space for snapshot names and IDs */
  55 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
  56
  57 /* Bitmap header extension constraints */
  58 #define QCOW2_MAX_BITMAPS 65535
  59 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  60
  61 /* indicate that the refcount of the referenced cluster is exactly one. */
  62 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  63 /* indicate that the cluster is compressed (they never have the copied flag) */
  64 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  65 /* The cluster reads as all zeros */
  66 #define QCOW_OFLAG_ZERO (1ULL << 0)
  67
  68 #define MIN_CLUSTER_BITS 9
  69 #define MAX_CLUSTER_BITS 21
  70
  71 /* Must be at least 2 to cover COW */
  72 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
  73
  74 /* Must be at least 4 to cover all cases of refcount table growth */
  75 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  76
  77 #ifdef CONFIG_LINUX
  78 #define DEFAULT_L2_CACHE_MAX_SIZE S_32MiB
  79 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
  80 #else
  81 #define DEFAULT_L2_CACHE_MAX_SIZE S_8MiB
  82 /* Cache clean interval is currently available only on Linux, so must be 0 */
  83 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
  84 #endif
  85
  86 #define DEFAULT_CLUSTER_SIZE S_64KiB
  87
  88 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
  89 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
  90 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
  91 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
  92 #define QCOW2_OPT_OVERLAP "overlap-check"
  93 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
  94 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
  95 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
  96 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
  97 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
  98 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
  99 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 100 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 101 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 102 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 103 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 104 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 105 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 106 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 107 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 108
 109 typedef struct QCowHeader {
 110     uint32_t magic;
 111     uint32_t version;
 112     uint64_t backing_file_offset;
 113     uint32_t backing_file_size;
 114     uint32_t cluster_bits;
 115     uint64_t size; /* in bytes */
 116     uint32_t crypt_method;
 117     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 118     uint64_t l1_table_offset;
 119     uint64_t refcount_table_offset;
 120     uint32_t refcount_table_clusters;
 121     uint32_t nb_snapshots;
 122     uint64_t snapshots_offset;
 123
 124     /* The following fields are only valid for version >= 3 */
 125     uint64_t incompatible_features;
 126     uint64_t compatible_features;
 127     uint64_t autoclear_features;
 128
 129     uint32_t refcount_order;
 130     uint32_t header_length;
 131 } QEMU_PACKED QCowHeader;
 132
 133 typedef struct QEMU_PACKED QCowSnapshotHeader {
 134     /* header is 8 byte aligned */
 135     uint64_t l1_table_offset;
 136
 137     uint32_t l1_size;
 138     uint16_t id_str_size;
 139     uint16_t name_size;
 140
 141     uint32_t date_sec;
 142     uint32_t date_nsec;
 143
 144     uint64_t vm_clock_nsec;
 145
 146     uint32_t vm_state_size;
 147     uint32_t extra_data_size; /* for extension */
 148     /* extra data follows */
 149     /* id_str follows */
 150     /* name follows  */
 151 } QCowSnapshotHeader;
 152
 153 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 154     uint64_t vm_state_size_large;
 155     uint64_t disk_size;
 156 } QCowSnapshotExtraData;
 157
 158
 159 typedef struct QCowSnapshot {
 160     uint64_t l1_table_offset;
 161     uint32_t l1_size;
 162     char *id_str;
 163     char *name;
 164     uint64_t disk_size;
 165     uint64_t vm_state_size;
 166     uint32_t date_sec;
 167     uint32_t date_nsec;
 168     uint64_t vm_clock_nsec;
 169 } QCowSnapshot;
 170
 171 struct Qcow2Cache;
 172 typedef struct Qcow2Cache Qcow2Cache;
 173
 174 typedef struct Qcow2CryptoHeaderExtension {
 175     uint64_t offset;
 176     uint64_t length;
 177 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 178
 179 typedef struct Qcow2UnknownHeaderExtension {
 180     uint32_t magic;
 181     uint32_t len;
 182     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 183     uint8_t data[];
 184 } Qcow2UnknownHeaderExtension;
 185
 186 enum {
 187     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 188     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 189     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 190 };
 191
 192 /* Incompatible feature bits */
 193 enum {
 194     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
 195     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
 196     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 197     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 198
 199     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
 200                                  | QCOW2_INCOMPAT_CORRUPT,
 201 };
 202
 203 /* Compatible feature bits */
 204 enum {
 205     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 206     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 207
 208     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 209 };
 210
 211 /* Autoclear feature bits */
 212 enum {
 213     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
 214     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 215
 216     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
 217 };
 218
 219 enum qcow2_discard_type {
 220     QCOW2_DISCARD_NEVER = 0,
 221     QCOW2_DISCARD_ALWAYS,
 222     QCOW2_DISCARD_REQUEST,
 223     QCOW2_DISCARD_SNAPSHOT,
 224     QCOW2_DISCARD_OTHER,
 225     QCOW2_DISCARD_MAX
 226 };
 227
 228 typedef struct Qcow2Feature {
 229     uint8_t type;
 230     uint8_t bit;
 231     char    name[46];
 232 } QEMU_PACKED Qcow2Feature;
 233
 234 typedef struct Qcow2DiscardRegion {
 235     BlockDriverState *bs;
 236     uint64_t offset;
 237     uint64_t bytes;
 238     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 239 } Qcow2DiscardRegion;
 240
 241 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 242                                       uint64_t index);
 243 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 244                                   uint64_t index, uint64_t value);
 245
 246 typedef struct Qcow2BitmapHeaderExt {
 247     uint32_t nb_bitmaps;
 248     uint32_t reserved32;
 249     uint64_t bitmap_directory_size;
 250     uint64_t bitmap_directory_offset;
 251 } QEMU_PACKED Qcow2BitmapHeaderExt;
 252
 253 typedef struct BDRVQcow2State {
 254     int cluster_bits;
 255     int cluster_size;
 256     int cluster_sectors;
 257     int l2_slice_size;
 258     int l2_bits;
 259     int l2_size;
 260     int l1_size;
 261     int l1_vm_state_index;
 262     int refcount_block_bits;
 263     int refcount_block_size;
 264     int csize_shift;
 265     int csize_mask;
 266     uint64_t cluster_offset_mask;
 267     uint64_t l1_table_offset;
 268     uint64_t *l1_table;
 269
 270     Qcow2Cache* l2_table_cache;
 271     Qcow2Cache* refcount_block_cache;
 272     QEMUTimer *cache_clean_timer;
 273     unsigned cache_clean_interval;
 274
 275     uint8_t *cluster_cache;
 276     uint8_t *cluster_data;
 277     uint64_t cluster_cache_offset;
 278     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
 279
 280     uint64_t *refcount_table;
 281     uint64_t refcount_table_offset;
 282     uint32_t refcount_table_size;
 283     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 284     uint64_t free_cluster_index;
 285     uint64_t free_byte_offset;
 286
 287     CoMutex lock;
 288
 289     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 290     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 291     QCryptoBlock *crypto; /* Disk encryption format driver */
 292     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 293                                    for encryption initialization vector tweak */
 294     uint32_t crypt_method_header;
 295     uint64_t snapshots_offset;
 296     int snapshots_size;
 297     unsigned int nb_snapshots;
 298     QCowSnapshot *snapshots;
 299
 300     uint32_t nb_bitmaps;
 301     uint64_t bitmap_directory_size;
 302     uint64_t bitmap_directory_offset;
 303     bool dirty_bitmaps_loaded;
 304
 305     int flags;
 306     int qcow_version;
 307     bool use_lazy_refcounts;
 308     int refcount_order;
 309     int refcount_bits;
 310     uint64_t refcount_max;
 311
 312     Qcow2GetRefcountFunc *get_refcount;
 313     Qcow2SetRefcountFunc *set_refcount;
 314
 315     bool discard_passthrough[QCOW2_DISCARD_MAX];
 316
 317     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 318     bool signaled_corruption;
 319
 320     uint64_t incompatible_features;
 321     uint64_t compatible_features;
 322     uint64_t autoclear_features;
 323
 324     size_t unknown_header_fields_size;
 325     void* unknown_header_fields;
 326     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 327     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 328     bool cache_discards;
 329
 330     /* Backing file path and format as stored in the image (this is not the
 331      * effective path/format, which may be the result of a runtime option
 332      * override) */
 333     char *image_backing_file;
 334     char *image_backing_format;
 335
 336     CoQueue compress_wait_queue;
 337     int nb_compress_threads;
 338 } BDRVQcow2State;
 339
 340 typedef struct Qcow2COWRegion {
 341     /**
 342      * Offset of the COW region in bytes from the start of the first cluster
 343      * touched by the request.
 344      */
 345     unsigned    offset;
 346
 347     /** Number of bytes to copy */
 348     unsigned    nb_bytes;
 349 } Qcow2COWRegion;
 350
 351 /**
 352  * Describes an in-flight (part of a) write request that writes to clusters
 353  * that are not referenced in their L2 table yet.
 354  */
 355 typedef struct QCowL2Meta
 356 {
 357     /** Guest offset of the first newly allocated cluster */
 358     uint64_t offset;
 359
 360     /** Host offset of the first newly allocated cluster */
 361     uint64_t alloc_offset;
 362
 363     /** Number of newly allocated clusters */
 364     int nb_clusters;
 365
 366     /** Do not free the old clusters */
 367     bool keep_old_clusters;
 368
 369     /**
 370      * Requests that overlap with this allocation and wait to be restarted
 371      * when the allocating request has completed.
 372      */
 373     CoQueue dependent_requests;
 374
 375     /**
 376      * The COW Region between the start of the first allocated cluster and the
 377      * area the guest actually writes to.
 378      */
 379     Qcow2COWRegion cow_start;
 380
 381     /**
 382      * The COW Region between the area the guest actually writes to and the
 383      * end of the last allocated cluster.
 384      */
 385     Qcow2COWRegion cow_end;
 386
 387     /**
 388      * The I/O vector with the data from the actual guest write request.
 389      * If non-NULL, this is meant to be merged together with the data
 390      * from @cow_start and @cow_end into one single write operation.
 391      */
 392     QEMUIOVector *data_qiov;
 393
 394     /** Pointer to next L2Meta of the same write request */
 395     struct QCowL2Meta *next;
 396
 397     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 398 } QCowL2Meta;
 399
 400 typedef enum QCow2ClusterType {
 401     QCOW2_CLUSTER_UNALLOCATED,
 402     QCOW2_CLUSTER_ZERO_PLAIN,
 403     QCOW2_CLUSTER_ZERO_ALLOC,
 404     QCOW2_CLUSTER_NORMAL,
 405     QCOW2_CLUSTER_COMPRESSED,
 406 } QCow2ClusterType;
 407
 408 typedef enum QCow2MetadataOverlap {
 409     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 410     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 411     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 412     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 413     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 414     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 415     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 416     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 417     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 418
 419     QCOW2_OL_MAX_BITNR              = 9,
 420
 421     QCOW2_OL_NONE             = 0,
 422     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 423     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 424     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 425     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 426     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 427     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 428     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 429     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 430      * reads. */
 431     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 432     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 433 } QCow2MetadataOverlap;
 434
 435 /* Perform all overlap checks which can be done in constant time */
 436 #define QCOW2_OL_CONSTANT \
 437     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 438      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 439
 440 /* Perform all overlap checks which don't require disk access */
 441 #define QCOW2_OL_CACHED \
 442     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 443      QCOW2_OL_INACTIVE_L1)
 444
 445 /* Perform all overlap checks */
 446 #define QCOW2_OL_ALL \
 447     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 448
 449 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 450 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 451 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 452
 453 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 454
 455 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 456 {
 457     return offset & ~(s->cluster_size - 1);
 458 }
 459
 460 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 461 {
 462     return offset & (s->cluster_size - 1);
 463 }
 464
 465 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 466 {
 467     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 468 }
 469
 470 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 471 {
 472     int shift = s->cluster_bits + s->l2_bits;
 473     return (size + (1ULL << shift) - 1) >> shift;
 474 }
 475
 476 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 477 {
 478     return offset >> (s->l2_bits + s->cluster_bits);
 479 }
 480
 481 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 482 {
 483     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 484 }
 485
 486 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 487 {
 488     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 489 }
 490
 491 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 492 {
 493     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 494 }
 495
 496 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
 497 {
 498     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 499         return QCOW2_CLUSTER_COMPRESSED;
 500     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 501         if (l2_entry & L2E_OFFSET_MASK) {
 502             return QCOW2_CLUSTER_ZERO_ALLOC;
 503         }
 504         return QCOW2_CLUSTER_ZERO_PLAIN;
 505     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 506         return QCOW2_CLUSTER_UNALLOCATED;
 507     } else {
 508         return QCOW2_CLUSTER_NORMAL;
 509     }
 510 }
 511
 512 /* Check whether refcounts are eager or lazy */
 513 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 514 {
 515     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 516 }
 517
 518 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 519 {
 520     return m->offset + m->cow_start.offset;
 521 }
 522
 523 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 524 {
 525     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 526 }
 527
 528 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 529 {
 530     return r1 > r2 ? r1 - r2 : r2 - r1;
 531 }
 532
 533 static inline
 534 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 535 {
 536     return offset >> (s->refcount_block_bits + s->cluster_bits);
 537 }
 538
 539 /* qcow2.c functions */
 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 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 554                          uint64_t entries, size_t entry_len,
 555                          int64_t max_size_bytes, const char *table_name,
 556                          Error **errp);
 557
 558 /* qcow2-refcount.c functions */
 559 int qcow2_refcount_init(BlockDriverState *bs);
 560 void qcow2_refcount_close(BlockDriverState *bs);
 561
 562 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 563                        uint64_t *refcount);
 564
 565 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 566                                   uint64_t addend, bool decrease,
 567                                   enum qcow2_discard_type type);
 568
 569 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 570                             uint64_t additional_clusters, bool exact_size,
 571                             int new_refblock_index,
 572                             uint64_t new_refblock_offset);
 573
 574 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 575 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 576                                 int64_t nb_clusters);
 577 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 578 void qcow2_free_clusters(BlockDriverState *bs,
 579                           int64_t offset, int64_t size,
 580                           enum qcow2_discard_type type);
 581 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 582                              int nb_clusters, enum qcow2_discard_type type);
 583
 584 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 585     int64_t l1_table_offset, int l1_size, int addend);
 586
 587 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 588 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 589 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 590                           BdrvCheckMode fix);
 591
 592 void qcow2_process_discards(BlockDriverState *bs, int ret);
 593
 594 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 595                                  int64_t size);
 596 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 597                                   int64_t size);
 598 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 599                              void **refcount_table,
 600                              int64_t *refcount_table_size,
 601                              int64_t offset, int64_t size);
 602
 603 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 604                                 BlockDriverAmendStatusCB *status_cb,
 605                                 void *cb_opaque, Error **errp);
 606 int qcow2_shrink_reftable(BlockDriverState *bs);
 607 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 608
 609 /* qcow2-cluster.c functions */
 610 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 611                         bool exact_size);
 612 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 613 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 614 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 615 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 616                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 617
 618 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 619                              unsigned int *bytes, uint64_t *cluster_offset);
 620 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 621                                unsigned int *bytes, uint64_t *host_offset,
 622                                QCowL2Meta **m);
 623 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 624                                          uint64_t offset,
 625                                          int compressed_size);
 626
 627 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 628 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 629 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 630                           uint64_t bytes, enum qcow2_discard_type type,
 631                           bool full_discard);
 632 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 633                           uint64_t bytes, int flags);
 634
 635 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 636                                BlockDriverAmendStatusCB *status_cb,
 637                                void *cb_opaque);
 638
 639 /* qcow2-snapshot.c functions */
 640 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 641 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 642 int qcow2_snapshot_delete(BlockDriverState *bs,
 643                           const char *snapshot_id,
 644                           const char *name,
 645                           Error **errp);
 646 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 647 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 648                             const char *snapshot_id,
 649                             const char *name,
 650                             Error **errp);
 651
 652 void qcow2_free_snapshots(BlockDriverState *bs);
 653 int qcow2_read_snapshots(BlockDriverState *bs);
 654
 655 /* qcow2-cache.c functions */
 656 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 657                                unsigned table_size);
 658 int qcow2_cache_destroy(Qcow2Cache *c);
 659
 660 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 661 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 662 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 663 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 664     Qcow2Cache *dependency);
 665 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 666
 667 void qcow2_cache_clean_unused(Qcow2Cache *c);
 668 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 669
 670 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 671     void **table);
 672 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 673     void **table);
 674 void qcow2_cache_put(Qcow2Cache *c, void **table);
 675 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 676 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 677
 678 /* qcow2-bitmap.c functions */
 679 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 680                                   void **refcount_table,
 681                                   int64_t *refcount_table_size);
 682 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 683 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
 684                                  Error **errp);
 685 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 686 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 687 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 688 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 689                                       const char *name,
 690                                       uint32_t granularity,
 691                                       Error **errp);
 692 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 693                                           const char *name,
 694                                           Error **errp);
 695
 696 #endif