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 #include "block/block_int.h"
  32
  33 //#define DEBUG_ALLOC
  34 //#define DEBUG_ALLOC2
  35 //#define DEBUG_EXT
  36
  37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
  38
  39 #define QCOW_CRYPT_NONE 0
  40 #define QCOW_CRYPT_AES  1
  41 #define QCOW_CRYPT_LUKS 2
  42
  43 #define QCOW_MAX_CRYPT_CLUSTERS 32
  44 #define QCOW_MAX_SNAPSHOTS 65536
  45
  46 /* Field widths in qcow2 mean normal cluster offsets cannot reach
  47  * 64PB; depending on cluster size, compressed clusters can have a
  48  * smaller limit (64PB for up to 16k clusters, then ramps down to
  49  * 512TB for 2M clusters).  */
  50 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
  51
  52 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
  53  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  54 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
  55
  56 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
  57  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  58 #define QCOW_MAX_L1_SIZE (32 * MiB)
  59
  60 /* Allow for an average of 1k per snapshot table entry, should be plenty of
  61  * space for snapshot names and IDs */
  62 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
  63
  64 /* Maximum amount of extra data per snapshot table entry to accept */
  65 #define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024
  66
  67 /* Bitmap header extension constraints */
  68 #define QCOW2_MAX_BITMAPS 65535
  69 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  70
  71 /* Maximum of parallel sub-request per guest request */
  72 #define QCOW2_MAX_WORKERS 8
  73
  74 /* indicate that the refcount of the referenced cluster is exactly one. */
  75 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  76 /* indicate that the cluster is compressed (they never have the copied flag) */
  77 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  78 /* The cluster reads as all zeros */
  79 #define QCOW_OFLAG_ZERO (1ULL << 0)
  80
  81 #define MIN_CLUSTER_BITS 9
  82 #define MAX_CLUSTER_BITS 21
  83
  84 /* Defined in the qcow2 spec (compressed cluster descriptor) */
  85 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
  86 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL))
  87
  88 /* Must be at least 2 to cover COW */
  89 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
  90
  91 /* Must be at least 4 to cover all cases of refcount table growth */
  92 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  93
  94 #ifdef CONFIG_LINUX
  95 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
  96 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
  97 #else
  98 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
  99 /* Cache clean interval is currently available only on Linux, so must be 0 */
 100 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
 101 #endif
 102
 103 #define DEFAULT_CLUSTER_SIZE 65536
 104
 105 #define QCOW2_OPT_DATA_FILE "data-file"
 106 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 107 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 108 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
 109 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
 110 #define QCOW2_OPT_OVERLAP "overlap-check"
 111 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 112 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 113 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 114 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 115 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 116 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 117 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 118 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 119 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 120 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 121 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 122 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 123 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 124 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 125 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 126
 127 typedef struct QCowHeader {
 128     uint32_t magic;
 129     uint32_t version;
 130     uint64_t backing_file_offset;
 131     uint32_t backing_file_size;
 132     uint32_t cluster_bits;
 133     uint64_t size; /* in bytes */
 134     uint32_t crypt_method;
 135     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 136     uint64_t l1_table_offset;
 137     uint64_t refcount_table_offset;
 138     uint32_t refcount_table_clusters;
 139     uint32_t nb_snapshots;
 140     uint64_t snapshots_offset;
 141
 142     /* The following fields are only valid for version >= 3 */
 143     uint64_t incompatible_features;
 144     uint64_t compatible_features;
 145     uint64_t autoclear_features;
 146
 147     uint32_t refcount_order;
 148     uint32_t header_length;
 149 } QEMU_PACKED QCowHeader;
 150
 151 typedef struct QEMU_PACKED QCowSnapshotHeader {
 152     /* header is 8 byte aligned */
 153     uint64_t l1_table_offset;
 154
 155     uint32_t l1_size;
 156     uint16_t id_str_size;
 157     uint16_t name_size;
 158
 159     uint32_t date_sec;
 160     uint32_t date_nsec;
 161
 162     uint64_t vm_clock_nsec;
 163
 164     uint32_t vm_state_size;
 165     uint32_t extra_data_size; /* for extension */
 166     /* extra data follows */
 167     /* id_str follows */
 168     /* name follows  */
 169 } QCowSnapshotHeader;
 170
 171 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 172     uint64_t vm_state_size_large;
 173     uint64_t disk_size;
 174 } QCowSnapshotExtraData;
 175
 176
 177 typedef struct QCowSnapshot {
 178     uint64_t l1_table_offset;
 179     uint32_t l1_size;
 180     char *id_str;
 181     char *name;
 182     uint64_t disk_size;
 183     uint64_t vm_state_size;
 184     uint32_t date_sec;
 185     uint32_t date_nsec;
 186     uint64_t vm_clock_nsec;
 187     /* Size of all extra data, including QCowSnapshotExtraData if available */
 188     uint32_t extra_data_size;
 189     /* Data beyond QCowSnapshotExtraData, if any */
 190     void *unknown_extra_data;
 191 } QCowSnapshot;
 192
 193 struct Qcow2Cache;
 194 typedef struct Qcow2Cache Qcow2Cache;
 195
 196 typedef struct Qcow2CryptoHeaderExtension {
 197     uint64_t offset;
 198     uint64_t length;
 199 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 200
 201 typedef struct Qcow2UnknownHeaderExtension {
 202     uint32_t magic;
 203     uint32_t len;
 204     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 205     uint8_t data[];
 206 } Qcow2UnknownHeaderExtension;
 207
 208 enum {
 209     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 210     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 211     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 212 };
 213
 214 /* Incompatible feature bits */
 215 enum {
 216     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 217     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 218     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 219     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 220     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 221     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 222
 223     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 224                                     | QCOW2_INCOMPAT_CORRUPT
 225                                     | QCOW2_INCOMPAT_DATA_FILE,
 226 };
 227
 228 /* Compatible feature bits */
 229 enum {
 230     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 231     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 232
 233     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 234 };
 235
 236 /* Autoclear feature bits */
 237 enum {
 238     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 239     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 240     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 241     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 242
 243     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 244                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 245 };
 246
 247 enum qcow2_discard_type {
 248     QCOW2_DISCARD_NEVER = 0,
 249     QCOW2_DISCARD_ALWAYS,
 250     QCOW2_DISCARD_REQUEST,
 251     QCOW2_DISCARD_SNAPSHOT,
 252     QCOW2_DISCARD_OTHER,
 253     QCOW2_DISCARD_MAX
 254 };
 255
 256 typedef struct Qcow2Feature {
 257     uint8_t type;
 258     uint8_t bit;
 259     char    name[46];
 260 } QEMU_PACKED Qcow2Feature;
 261
 262 typedef struct Qcow2DiscardRegion {
 263     BlockDriverState *bs;
 264     uint64_t offset;
 265     uint64_t bytes;
 266     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 267 } Qcow2DiscardRegion;
 268
 269 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 270                                       uint64_t index);
 271 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 272                                   uint64_t index, uint64_t value);
 273
 274 typedef struct Qcow2BitmapHeaderExt {
 275     uint32_t nb_bitmaps;
 276     uint32_t reserved32;
 277     uint64_t bitmap_directory_size;
 278     uint64_t bitmap_directory_offset;
 279 } QEMU_PACKED Qcow2BitmapHeaderExt;
 280
 281 #define QCOW2_MAX_THREADS 4
 282
 283 typedef struct BDRVQcow2State {
 284     int cluster_bits;
 285     int cluster_size;
 286     int l2_slice_size;
 287     int l2_bits;
 288     int l2_size;
 289     int l1_size;
 290     int l1_vm_state_index;
 291     int refcount_block_bits;
 292     int refcount_block_size;
 293     int csize_shift;
 294     int csize_mask;
 295     uint64_t cluster_offset_mask;
 296     uint64_t l1_table_offset;
 297     uint64_t *l1_table;
 298
 299     Qcow2Cache* l2_table_cache;
 300     Qcow2Cache* refcount_block_cache;
 301     QEMUTimer *cache_clean_timer;
 302     unsigned cache_clean_interval;
 303
 304     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 305
 306     uint64_t *refcount_table;
 307     uint64_t refcount_table_offset;
 308     uint32_t refcount_table_size;
 309     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 310     uint64_t free_cluster_index;
 311     uint64_t free_byte_offset;
 312
 313     CoMutex lock;
 314
 315     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 316     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 317     QCryptoBlock *crypto; /* Disk encryption format driver */
 318     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 319                                    for encryption initialization vector tweak */
 320     uint32_t crypt_method_header;
 321     uint64_t snapshots_offset;
 322     int snapshots_size;
 323     unsigned int nb_snapshots;
 324     QCowSnapshot *snapshots;
 325
 326     uint32_t nb_bitmaps;
 327     uint64_t bitmap_directory_size;
 328     uint64_t bitmap_directory_offset;
 329
 330     int flags;
 331     int qcow_version;
 332     bool use_lazy_refcounts;
 333     int refcount_order;
 334     int refcount_bits;
 335     uint64_t refcount_max;
 336
 337     Qcow2GetRefcountFunc *get_refcount;
 338     Qcow2SetRefcountFunc *set_refcount;
 339
 340     bool discard_passthrough[QCOW2_DISCARD_MAX];
 341
 342     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 343     bool signaled_corruption;
 344
 345     uint64_t incompatible_features;
 346     uint64_t compatible_features;
 347     uint64_t autoclear_features;
 348
 349     size_t unknown_header_fields_size;
 350     void* unknown_header_fields;
 351     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 352     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 353     bool cache_discards;
 354
 355     /* Backing file path and format as stored in the image (this is not the
 356      * effective path/format, which may be the result of a runtime option
 357      * override) */
 358     char *image_backing_file;
 359     char *image_backing_format;
 360     char *image_data_file;
 361
 362     CoQueue thread_task_queue;
 363     int nb_threads;
 364
 365     BdrvChild *data_file;
 366
 367     bool metadata_preallocation_checked;
 368     bool metadata_preallocation;
 369 } BDRVQcow2State;
 370
 371 typedef struct Qcow2COWRegion {
 372     /**
 373      * Offset of the COW region in bytes from the start of the first cluster
 374      * touched by the request.
 375      */
 376     unsigned    offset;
 377
 378     /** Number of bytes to copy */
 379     unsigned    nb_bytes;
 380 } Qcow2COWRegion;
 381
 382 /**
 383  * Describes an in-flight (part of a) write request that writes to clusters
 384  * that are not referenced in their L2 table yet.
 385  */
 386 typedef struct QCowL2Meta
 387 {
 388     /** Guest offset of the first newly allocated cluster */
 389     uint64_t offset;
 390
 391     /** Host offset of the first newly allocated cluster */
 392     uint64_t alloc_offset;
 393
 394     /** Number of newly allocated clusters */
 395     int nb_clusters;
 396
 397     /** Do not free the old clusters */
 398     bool keep_old_clusters;
 399
 400     /**
 401      * Requests that overlap with this allocation and wait to be restarted
 402      * when the allocating request has completed.
 403      */
 404     CoQueue dependent_requests;
 405
 406     /**
 407      * The COW Region between the start of the first allocated cluster and the
 408      * area the guest actually writes to.
 409      */
 410     Qcow2COWRegion cow_start;
 411
 412     /**
 413      * The COW Region between the area the guest actually writes to and the
 414      * end of the last allocated cluster.
 415      */
 416     Qcow2COWRegion cow_end;
 417
 418     /*
 419      * Indicates that COW regions are already handled and do not require
 420      * any more processing.
 421      */
 422     bool skip_cow;
 423
 424     /**
 425      * The I/O vector with the data from the actual guest write request.
 426      * If non-NULL, this is meant to be merged together with the data
 427      * from @cow_start and @cow_end into one single write operation.
 428      */
 429     QEMUIOVector *data_qiov;
 430     size_t data_qiov_offset;
 431
 432     /** Pointer to next L2Meta of the same write request */
 433     struct QCowL2Meta *next;
 434
 435     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 436 } QCowL2Meta;
 437
 438 typedef enum QCow2ClusterType {
 439     QCOW2_CLUSTER_UNALLOCATED,
 440     QCOW2_CLUSTER_ZERO_PLAIN,
 441     QCOW2_CLUSTER_ZERO_ALLOC,
 442     QCOW2_CLUSTER_NORMAL,
 443     QCOW2_CLUSTER_COMPRESSED,
 444 } QCow2ClusterType;
 445
 446 typedef enum QCow2MetadataOverlap {
 447     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 448     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 449     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 450     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 451     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 452     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 453     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 454     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 455     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 456
 457     QCOW2_OL_MAX_BITNR              = 9,
 458
 459     QCOW2_OL_NONE             = 0,
 460     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 461     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 462     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 463     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 464     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 465     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 466     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 467     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 468      * reads. */
 469     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 470     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 471 } QCow2MetadataOverlap;
 472
 473 /* Perform all overlap checks which can be done in constant time */
 474 #define QCOW2_OL_CONSTANT \
 475     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 476      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 477
 478 /* Perform all overlap checks which don't require disk access */
 479 #define QCOW2_OL_CACHED \
 480     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 481      QCOW2_OL_INACTIVE_L1)
 482
 483 /* Perform all overlap checks */
 484 #define QCOW2_OL_ALL \
 485     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 486
 487 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 488 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 489 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 490
 491 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 492
 493 #define INV_OFFSET (-1ULL)
 494
 495 static inline bool has_data_file(BlockDriverState *bs)
 496 {
 497     BDRVQcow2State *s = bs->opaque;
 498     return (s->data_file != bs->file);
 499 }
 500
 501 static inline bool data_file_is_raw(BlockDriverState *bs)
 502 {
 503     BDRVQcow2State *s = bs->opaque;
 504     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 505 }
 506
 507 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 508 {
 509     return offset & ~(s->cluster_size - 1);
 510 }
 511
 512 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 513 {
 514     return offset & (s->cluster_size - 1);
 515 }
 516
 517 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 518 {
 519     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 520 }
 521
 522 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 523 {
 524     int shift = s->cluster_bits + s->l2_bits;
 525     return (size + (1ULL << shift) - 1) >> shift;
 526 }
 527
 528 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 529 {
 530     return offset >> (s->l2_bits + s->cluster_bits);
 531 }
 532
 533 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 534 {
 535     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 536 }
 537
 538 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 539 {
 540     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 541 }
 542
 543 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 544 {
 545     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 546 }
 547
 548 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 549                                                       uint64_t l2_entry)
 550 {
 551     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 552         return QCOW2_CLUSTER_COMPRESSED;
 553     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 554         if (l2_entry & L2E_OFFSET_MASK) {
 555             return QCOW2_CLUSTER_ZERO_ALLOC;
 556         }
 557         return QCOW2_CLUSTER_ZERO_PLAIN;
 558     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 559         /* Offset 0 generally means unallocated, but it is ambiguous with
 560          * external data files because 0 is a valid offset there. However, all
 561          * clusters in external data files always have refcount 1, so we can
 562          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 563         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 564             return QCOW2_CLUSTER_NORMAL;
 565         } else {
 566             return QCOW2_CLUSTER_UNALLOCATED;
 567         }
 568     } else {
 569         return QCOW2_CLUSTER_NORMAL;
 570     }
 571 }
 572
 573 /* Check whether refcounts are eager or lazy */
 574 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 575 {
 576     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 577 }
 578
 579 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 580 {
 581     return m->offset + m->cow_start.offset;
 582 }
 583
 584 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 585 {
 586     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 587 }
 588
 589 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 590 {
 591     return r1 > r2 ? r1 - r2 : r2 - r1;
 592 }
 593
 594 static inline
 595 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 596 {
 597     return offset >> (s->refcount_block_bits + s->cluster_bits);
 598 }
 599
 600 /* qcow2.c functions */
 601 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 602                                      int refcount_order, bool generous_increase,
 603                                      uint64_t *refblock_count);
 604
 605 int qcow2_mark_dirty(BlockDriverState *bs);
 606 int qcow2_mark_corrupt(BlockDriverState *bs);
 607 int qcow2_mark_consistent(BlockDriverState *bs);
 608 int qcow2_update_header(BlockDriverState *bs);
 609
 610 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 611                              int64_t size, const char *message_format, ...)
 612                              GCC_FMT_ATTR(5, 6);
 613
 614 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 615                          uint64_t entries, size_t entry_len,
 616                          int64_t max_size_bytes, const char *table_name,
 617                          Error **errp);
 618
 619 /* qcow2-refcount.c functions */
 620 int qcow2_refcount_init(BlockDriverState *bs);
 621 void qcow2_refcount_close(BlockDriverState *bs);
 622
 623 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 624                        uint64_t *refcount);
 625
 626 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 627                                   uint64_t addend, bool decrease,
 628                                   enum qcow2_discard_type type);
 629
 630 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 631                             uint64_t additional_clusters, bool exact_size,
 632                             int new_refblock_index,
 633                             uint64_t new_refblock_offset);
 634
 635 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 636 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 637                                 int64_t nb_clusters);
 638 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 639 void qcow2_free_clusters(BlockDriverState *bs,
 640                           int64_t offset, int64_t size,
 641                           enum qcow2_discard_type type);
 642 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 643                              int nb_clusters, enum qcow2_discard_type type);
 644
 645 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 646     int64_t l1_table_offset, int l1_size, int addend);
 647
 648 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 649 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 650 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 651                           BdrvCheckMode fix);
 652
 653 void qcow2_process_discards(BlockDriverState *bs, int ret);
 654
 655 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 656                                  int64_t size);
 657 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 658                                   int64_t size, bool data_file);
 659 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 660                              void **refcount_table,
 661                              int64_t *refcount_table_size,
 662                              int64_t offset, int64_t size);
 663
 664 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 665                                 BlockDriverAmendStatusCB *status_cb,
 666                                 void *cb_opaque, Error **errp);
 667 int qcow2_shrink_reftable(BlockDriverState *bs);
 668 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 669 int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
 670
 671 /* qcow2-cluster.c functions */
 672 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 673                         bool exact_size);
 674 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 675 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 676 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 677                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 678
 679 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 680                              unsigned int *bytes, uint64_t *cluster_offset);
 681 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 682                                unsigned int *bytes, uint64_t *host_offset,
 683                                QCowL2Meta **m);
 684 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 685                                           uint64_t offset,
 686                                           int compressed_size,
 687                                           uint64_t *host_offset);
 688
 689 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 690 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 691 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 692                           uint64_t bytes, enum qcow2_discard_type type,
 693                           bool full_discard);
 694 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 695                           uint64_t bytes, int flags);
 696
 697 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 698                                BlockDriverAmendStatusCB *status_cb,
 699                                void *cb_opaque);
 700
 701 /* qcow2-snapshot.c functions */
 702 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 703 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 704 int qcow2_snapshot_delete(BlockDriverState *bs,
 705                           const char *snapshot_id,
 706                           const char *name,
 707                           Error **errp);
 708 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 709 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 710                             const char *snapshot_id,
 711                             const char *name,
 712                             Error **errp);
 713
 714 void qcow2_free_snapshots(BlockDriverState *bs);
 715 int qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
 716 int qcow2_write_snapshots(BlockDriverState *bs);
 717
 718 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
 719                                                  BdrvCheckResult *result,
 720                                                  BdrvCheckMode fix);
 721 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
 722                                                 BdrvCheckResult *result,
 723                                                 BdrvCheckMode fix);
 724
 725 /* qcow2-cache.c functions */
 726 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 727                                unsigned table_size);
 728 int qcow2_cache_destroy(Qcow2Cache *c);
 729
 730 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 731 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 732 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 733 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 734     Qcow2Cache *dependency);
 735 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 736
 737 void qcow2_cache_clean_unused(Qcow2Cache *c);
 738 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 739
 740 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 741     void **table);
 742 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 743     void **table);
 744 void qcow2_cache_put(Qcow2Cache *c, void **table);
 745 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 746 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 747
 748 /* qcow2-bitmap.c functions */
 749 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 750                                   void **refcount_table,
 751                                   int64_t *refcount_table_size);
 752 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 753 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
 754                                                 Error **errp);
 755 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 756 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
 757 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
 758                                           bool release_stored, Error **errp);
 759 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 760 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
 761                                          const char *name,
 762                                          uint32_t granularity,
 763                                          Error **errp);
 764 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 765                                             const char *name,
 766                                             Error **errp);
 767
 768 ssize_t coroutine_fn
 769 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
 770                   const void *src, size_t src_size);
 771 ssize_t coroutine_fn
 772 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
 773                     const void *src, size_t src_size);
 774 int coroutine_fn
 775 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
 776                  uint64_t guest_offset, void *buf, size_t len);
 777 int coroutine_fn
 778 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
 779                  uint64_t guest_offset, void *buf, size_t len);
 780
 781 #endif