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 /* Field widths in qcow2 mean normal cluster offsets cannot reach
  46  * 64PB; depending on cluster size, compressed clusters can have a
  47  * smaller limit (64PB for up to 16k clusters, then ramps down to
  48  * 512TB for 2M clusters).  */
  49 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
  50
  51 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
  52  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  53 #define QCOW_MAX_REFTABLE_SIZE S_8MiB
  54
  55 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
  56  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  57 #define QCOW_MAX_L1_SIZE S_32MiB
  58
  59 /* Allow for an average of 1k per snapshot table entry, should be plenty of
  60  * space for snapshot names and IDs */
  61 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
  62
  63 /* Bitmap header extension constraints */
  64 #define QCOW2_MAX_BITMAPS 65535
  65 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  66
  67 /* indicate that the refcount of the referenced cluster is exactly one. */
  68 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  69 /* indicate that the cluster is compressed (they never have the copied flag) */
  70 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  71 /* The cluster reads as all zeros */
  72 #define QCOW_OFLAG_ZERO (1ULL << 0)
  73
  74 #define MIN_CLUSTER_BITS 9
  75 #define MAX_CLUSTER_BITS 21
  76
  77 /* Must be at least 2 to cover COW */
  78 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
  79
  80 /* Must be at least 4 to cover all cases of refcount table growth */
  81 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  82
  83 #ifdef CONFIG_LINUX
  84 #define DEFAULT_L2_CACHE_MAX_SIZE S_32MiB
  85 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
  86 #else
  87 #define DEFAULT_L2_CACHE_MAX_SIZE S_8MiB
  88 /* Cache clean interval is currently available only on Linux, so must be 0 */
  89 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
  90 #endif
  91
  92 #define DEFAULT_CLUSTER_SIZE S_64KiB
  93
  94 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
  95 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
  96 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
  97 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
  98 #define QCOW2_OPT_OVERLAP "overlap-check"
  99 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 100 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 101 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 102 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 103 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 104 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 105 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 106 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 107 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 108 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 109 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 110 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 111 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 112 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 113 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 114
 115 typedef struct QCowHeader {
 116     uint32_t magic;
 117     uint32_t version;
 118     uint64_t backing_file_offset;
 119     uint32_t backing_file_size;
 120     uint32_t cluster_bits;
 121     uint64_t size; /* in bytes */
 122     uint32_t crypt_method;
 123     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 124     uint64_t l1_table_offset;
 125     uint64_t refcount_table_offset;
 126     uint32_t refcount_table_clusters;
 127     uint32_t nb_snapshots;
 128     uint64_t snapshots_offset;
 129
 130     /* The following fields are only valid for version >= 3 */
 131     uint64_t incompatible_features;
 132     uint64_t compatible_features;
 133     uint64_t autoclear_features;
 134
 135     uint32_t refcount_order;
 136     uint32_t header_length;
 137 } QEMU_PACKED QCowHeader;
 138
 139 typedef struct QEMU_PACKED QCowSnapshotHeader {
 140     /* header is 8 byte aligned */
 141     uint64_t l1_table_offset;
 142
 143     uint32_t l1_size;
 144     uint16_t id_str_size;
 145     uint16_t name_size;
 146
 147     uint32_t date_sec;
 148     uint32_t date_nsec;
 149
 150     uint64_t vm_clock_nsec;
 151
 152     uint32_t vm_state_size;
 153     uint32_t extra_data_size; /* for extension */
 154     /* extra data follows */
 155     /* id_str follows */
 156     /* name follows  */
 157 } QCowSnapshotHeader;
 158
 159 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 160     uint64_t vm_state_size_large;
 161     uint64_t disk_size;
 162 } QCowSnapshotExtraData;
 163
 164
 165 typedef struct QCowSnapshot {
 166     uint64_t l1_table_offset;
 167     uint32_t l1_size;
 168     char *id_str;
 169     char *name;
 170     uint64_t disk_size;
 171     uint64_t vm_state_size;
 172     uint32_t date_sec;
 173     uint32_t date_nsec;
 174     uint64_t vm_clock_nsec;
 175 } QCowSnapshot;
 176
 177 struct Qcow2Cache;
 178 typedef struct Qcow2Cache Qcow2Cache;
 179
 180 typedef struct Qcow2CryptoHeaderExtension {
 181     uint64_t offset;
 182     uint64_t length;
 183 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 184
 185 typedef struct Qcow2UnknownHeaderExtension {
 186     uint32_t magic;
 187     uint32_t len;
 188     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 189     uint8_t data[];
 190 } Qcow2UnknownHeaderExtension;
 191
 192 enum {
 193     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 194     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 195     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 196 };
 197
 198 /* Incompatible feature bits */
 199 enum {
 200     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
 201     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
 202     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 203     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 204
 205     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
 206                                  | QCOW2_INCOMPAT_CORRUPT,
 207 };
 208
 209 /* Compatible feature bits */
 210 enum {
 211     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 212     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 213
 214     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 215 };
 216
 217 /* Autoclear feature bits */
 218 enum {
 219     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
 220     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 221
 222     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
 223 };
 224
 225 enum qcow2_discard_type {
 226     QCOW2_DISCARD_NEVER = 0,
 227     QCOW2_DISCARD_ALWAYS,
 228     QCOW2_DISCARD_REQUEST,
 229     QCOW2_DISCARD_SNAPSHOT,
 230     QCOW2_DISCARD_OTHER,
 231     QCOW2_DISCARD_MAX
 232 };
 233
 234 typedef struct Qcow2Feature {
 235     uint8_t type;
 236     uint8_t bit;
 237     char    name[46];
 238 } QEMU_PACKED Qcow2Feature;
 239
 240 typedef struct Qcow2DiscardRegion {
 241     BlockDriverState *bs;
 242     uint64_t offset;
 243     uint64_t bytes;
 244     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 245 } Qcow2DiscardRegion;
 246
 247 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 248                                       uint64_t index);
 249 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 250                                   uint64_t index, uint64_t value);
 251
 252 typedef struct Qcow2BitmapHeaderExt {
 253     uint32_t nb_bitmaps;
 254     uint32_t reserved32;
 255     uint64_t bitmap_directory_size;
 256     uint64_t bitmap_directory_offset;
 257 } QEMU_PACKED Qcow2BitmapHeaderExt;
 258
 259 typedef struct BDRVQcow2State {
 260     int cluster_bits;
 261     int cluster_size;
 262     int cluster_sectors;
 263     int l2_slice_size;
 264     int l2_bits;
 265     int l2_size;
 266     int l1_size;
 267     int l1_vm_state_index;
 268     int refcount_block_bits;
 269     int refcount_block_size;
 270     int csize_shift;
 271     int csize_mask;
 272     uint64_t cluster_offset_mask;
 273     uint64_t l1_table_offset;
 274     uint64_t *l1_table;
 275
 276     Qcow2Cache* l2_table_cache;
 277     Qcow2Cache* refcount_block_cache;
 278     QEMUTimer *cache_clean_timer;
 279     unsigned cache_clean_interval;
 280
 281     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
 282
 283     uint64_t *refcount_table;
 284     uint64_t refcount_table_offset;
 285     uint32_t refcount_table_size;
 286     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 287     uint64_t free_cluster_index;
 288     uint64_t free_byte_offset;
 289
 290     CoMutex lock;
 291
 292     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 293     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 294     QCryptoBlock *crypto; /* Disk encryption format driver */
 295     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 296                                    for encryption initialization vector tweak */
 297     uint32_t crypt_method_header;
 298     uint64_t snapshots_offset;
 299     int snapshots_size;
 300     unsigned int nb_snapshots;
 301     QCowSnapshot *snapshots;
 302
 303     uint32_t nb_bitmaps;
 304     uint64_t bitmap_directory_size;
 305     uint64_t bitmap_directory_offset;
 306
 307     int flags;
 308     int qcow_version;
 309     bool use_lazy_refcounts;
 310     int refcount_order;
 311     int refcount_bits;
 312     uint64_t refcount_max;
 313
 314     Qcow2GetRefcountFunc *get_refcount;
 315     Qcow2SetRefcountFunc *set_refcount;
 316
 317     bool discard_passthrough[QCOW2_DISCARD_MAX];
 318
 319     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 320     bool signaled_corruption;
 321
 322     uint64_t incompatible_features;
 323     uint64_t compatible_features;
 324     uint64_t autoclear_features;
 325
 326     size_t unknown_header_fields_size;
 327     void* unknown_header_fields;
 328     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 329     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 330     bool cache_discards;
 331
 332     /* Backing file path and format as stored in the image (this is not the
 333      * effective path/format, which may be the result of a runtime option
 334      * override) */
 335     char *image_backing_file;
 336     char *image_backing_format;
 337
 338     CoQueue compress_wait_queue;
 339     int nb_compress_threads;
 340 } BDRVQcow2State;
 341
 342 typedef struct Qcow2COWRegion {
 343     /**
 344      * Offset of the COW region in bytes from the start of the first cluster
 345      * touched by the request.
 346      */
 347     unsigned    offset;
 348
 349     /** Number of bytes to copy */
 350     unsigned    nb_bytes;
 351 } Qcow2COWRegion;
 352
 353 /**
 354  * Describes an in-flight (part of a) write request that writes to clusters
 355  * that are not referenced in their L2 table yet.
 356  */
 357 typedef struct QCowL2Meta
 358 {
 359     /** Guest offset of the first newly allocated cluster */
 360     uint64_t offset;
 361
 362     /** Host offset of the first newly allocated cluster */
 363     uint64_t alloc_offset;
 364
 365     /** Number of newly allocated clusters */
 366     int nb_clusters;
 367
 368     /** Do not free the old clusters */
 369     bool keep_old_clusters;
 370
 371     /**
 372      * Requests that overlap with this allocation and wait to be restarted
 373      * when the allocating request has completed.
 374      */
 375     CoQueue dependent_requests;
 376
 377     /**
 378      * The COW Region between the start of the first allocated cluster and the
 379      * area the guest actually writes to.
 380      */
 381     Qcow2COWRegion cow_start;
 382
 383     /**
 384      * The COW Region between the area the guest actually writes to and the
 385      * end of the last allocated cluster.
 386      */
 387     Qcow2COWRegion cow_end;
 388
 389     /**
 390      * The I/O vector with the data from the actual guest write request.
 391      * If non-NULL, this is meant to be merged together with the data
 392      * from @cow_start and @cow_end into one single write operation.
 393      */
 394     QEMUIOVector *data_qiov;
 395
 396     /** Pointer to next L2Meta of the same write request */
 397     struct QCowL2Meta *next;
 398
 399     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 400 } QCowL2Meta;
 401
 402 typedef enum QCow2ClusterType {
 403     QCOW2_CLUSTER_UNALLOCATED,
 404     QCOW2_CLUSTER_ZERO_PLAIN,
 405     QCOW2_CLUSTER_ZERO_ALLOC,
 406     QCOW2_CLUSTER_NORMAL,
 407     QCOW2_CLUSTER_COMPRESSED,
 408 } QCow2ClusterType;
 409
 410 typedef enum QCow2MetadataOverlap {
 411     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 412     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 413     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 414     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 415     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 416     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 417     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 418     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 419     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 420
 421     QCOW2_OL_MAX_BITNR              = 9,
 422
 423     QCOW2_OL_NONE             = 0,
 424     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 425     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 426     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 427     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 428     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 429     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 430     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 431     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 432      * reads. */
 433     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 434     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 435 } QCow2MetadataOverlap;
 436
 437 /* Perform all overlap checks which can be done in constant time */
 438 #define QCOW2_OL_CONSTANT \
 439     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 440      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 441
 442 /* Perform all overlap checks which don't require disk access */
 443 #define QCOW2_OL_CACHED \
 444     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 445      QCOW2_OL_INACTIVE_L1)
 446
 447 /* Perform all overlap checks */
 448 #define QCOW2_OL_ALL \
 449     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 450
 451 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 452 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 453 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 454
 455 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 456
 457 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 458 {
 459     return offset & ~(s->cluster_size - 1);
 460 }
 461
 462 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 463 {
 464     return offset & (s->cluster_size - 1);
 465 }
 466
 467 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 468 {
 469     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 470 }
 471
 472 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 473 {
 474     int shift = s->cluster_bits + s->l2_bits;
 475     return (size + (1ULL << shift) - 1) >> shift;
 476 }
 477
 478 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 479 {
 480     return offset >> (s->l2_bits + s->cluster_bits);
 481 }
 482
 483 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 484 {
 485     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 486 }
 487
 488 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 489 {
 490     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 491 }
 492
 493 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 494 {
 495     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 496 }
 497
 498 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
 499 {
 500     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 501         return QCOW2_CLUSTER_COMPRESSED;
 502     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 503         if (l2_entry & L2E_OFFSET_MASK) {
 504             return QCOW2_CLUSTER_ZERO_ALLOC;
 505         }
 506         return QCOW2_CLUSTER_ZERO_PLAIN;
 507     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 508         return QCOW2_CLUSTER_UNALLOCATED;
 509     } else {
 510         return QCOW2_CLUSTER_NORMAL;
 511     }
 512 }
 513
 514 /* Check whether refcounts are eager or lazy */
 515 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 516 {
 517     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 518 }
 519
 520 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 521 {
 522     return m->offset + m->cow_start.offset;
 523 }
 524
 525 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 526 {
 527     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 528 }
 529
 530 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 531 {
 532     return r1 > r2 ? r1 - r2 : r2 - r1;
 533 }
 534
 535 static inline
 536 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 537 {
 538     return offset >> (s->refcount_block_bits + s->cluster_bits);
 539 }
 540
 541 /* qcow2.c functions */
 542 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 543                                      int refcount_order, bool generous_increase,
 544                                      uint64_t *refblock_count);
 545
 546 int qcow2_mark_dirty(BlockDriverState *bs);
 547 int qcow2_mark_corrupt(BlockDriverState *bs);
 548 int qcow2_mark_consistent(BlockDriverState *bs);
 549 int qcow2_update_header(BlockDriverState *bs);
 550
 551 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 552                              int64_t size, const char *message_format, ...)
 553                              GCC_FMT_ATTR(5, 6);
 554
 555 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 556                          uint64_t entries, size_t entry_len,
 557                          int64_t max_size_bytes, const char *table_name,
 558                          Error **errp);
 559
 560 /* qcow2-refcount.c functions */
 561 int qcow2_refcount_init(BlockDriverState *bs);
 562 void qcow2_refcount_close(BlockDriverState *bs);
 563
 564 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 565                        uint64_t *refcount);
 566
 567 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 568                                   uint64_t addend, bool decrease,
 569                                   enum qcow2_discard_type type);
 570
 571 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 572                             uint64_t additional_clusters, bool exact_size,
 573                             int new_refblock_index,
 574                             uint64_t new_refblock_offset);
 575
 576 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 577 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 578                                 int64_t nb_clusters);
 579 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 580 void qcow2_free_clusters(BlockDriverState *bs,
 581                           int64_t offset, int64_t size,
 582                           enum qcow2_discard_type type);
 583 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 584                              int nb_clusters, enum qcow2_discard_type type);
 585
 586 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 587     int64_t l1_table_offset, int l1_size, int addend);
 588
 589 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 590 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 591 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 592                           BdrvCheckMode fix);
 593
 594 void qcow2_process_discards(BlockDriverState *bs, int ret);
 595
 596 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 597                                  int64_t size);
 598 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 599                                   int64_t size);
 600 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 601                              void **refcount_table,
 602                              int64_t *refcount_table_size,
 603                              int64_t offset, int64_t size);
 604
 605 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 606                                 BlockDriverAmendStatusCB *status_cb,
 607                                 void *cb_opaque, Error **errp);
 608 int qcow2_shrink_reftable(BlockDriverState *bs);
 609 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 610
 611 /* qcow2-cluster.c functions */
 612 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 613                         bool exact_size);
 614 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 615 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 616 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 617                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 618
 619 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 620                              unsigned int *bytes, uint64_t *cluster_offset);
 621 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 622                                unsigned int *bytes, uint64_t *host_offset,
 623                                QCowL2Meta **m);
 624 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 625                                          uint64_t offset,
 626                                          int compressed_size);
 627
 628 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 629 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 630 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 631                           uint64_t bytes, enum qcow2_discard_type type,
 632                           bool full_discard);
 633 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 634                           uint64_t bytes, int flags);
 635
 636 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 637                                BlockDriverAmendStatusCB *status_cb,
 638                                void *cb_opaque);
 639
 640 /* qcow2-snapshot.c functions */
 641 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 642 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 643 int qcow2_snapshot_delete(BlockDriverState *bs,
 644                           const char *snapshot_id,
 645                           const char *name,
 646                           Error **errp);
 647 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 648 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 649                             const char *snapshot_id,
 650                             const char *name,
 651                             Error **errp);
 652
 653 void qcow2_free_snapshots(BlockDriverState *bs);
 654 int qcow2_read_snapshots(BlockDriverState *bs);
 655
 656 /* qcow2-cache.c functions */
 657 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 658                                unsigned table_size);
 659 int qcow2_cache_destroy(Qcow2Cache *c);
 660
 661 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 662 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 663 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 664 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 665     Qcow2Cache *dependency);
 666 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 667
 668 void qcow2_cache_clean_unused(Qcow2Cache *c);
 669 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 670
 671 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 672     void **table);
 673 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 674     void **table);
 675 void qcow2_cache_put(Qcow2Cache *c, void **table);
 676 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 677 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 678
 679 /* qcow2-bitmap.c functions */
 680 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 681                                   void **refcount_table,
 682                                   int64_t *refcount_table_size);
 683 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 684 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
 685                                  Error **errp);
 686 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 687 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 688 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 689 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 690                                       const char *name,
 691                                       uint32_t granularity,
 692                                       Error **errp);
 693 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 694                                           const char *name,
 695                                           Error **errp);
 696
 697 #endif