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 QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32
  82
  83 /* The subcluster X [0..31] is allocated */
  84 #define QCOW_OFLAG_SUB_ALLOC(X)   (1ULL << (X))
  85 /* The subcluster X [0..31] reads as zeroes */
  86 #define QCOW_OFLAG_SUB_ZERO(X)    (QCOW_OFLAG_SUB_ALLOC(X) << 32)
  87 /* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */
  88 #define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \
  89     (QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X))
  90 /* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */
  91 #define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \
  92     (QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32)
  93 /* L2 entry bitmap with all allocation bits set */
  94 #define QCOW_L2_BITMAP_ALL_ALLOC  (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32))
  95 /* L2 entry bitmap with all "read as zeroes" bits set */
  96 #define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32))
  97
  98 /* Size of normal and extended L2 entries */
  99 #define L2E_SIZE_NORMAL   (sizeof(uint64_t))
 100 #define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2)
 101
 102 /* Size of L1 table entries */
 103 #define L1E_SIZE (sizeof(uint64_t))
 104
 105 /* Size of reftable entries */
 106 #define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))
 107
 108 #define MIN_CLUSTER_BITS 9
 109 #define MAX_CLUSTER_BITS 21
 110
 111 /* Defined in the qcow2 spec (compressed cluster descriptor) */
 112 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
 113
 114 /* Must be at least 2 to cover COW */
 115 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
 116
 117 /* Must be at least 4 to cover all cases of refcount table growth */
 118 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
 119
 120 #ifdef CONFIG_LINUX
 121 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
 122 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
 123 #else
 124 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
 125 /* Cache clean interval is currently available only on Linux, so must be 0 */
 126 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
 127 #endif
 128
 129 #define DEFAULT_CLUSTER_SIZE 65536
 130
 131 #define QCOW2_OPT_DATA_FILE "data-file"
 132 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 133 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 134 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
 135 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
 136 #define QCOW2_OPT_DISCARD_NO_UNREF "discard-no-unref"
 137 #define QCOW2_OPT_OVERLAP "overlap-check"
 138 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 139 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 140 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 141 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 142 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 143 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 144 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 145 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 146 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 147 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 148 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 149 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 150 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 151 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 152 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 153
 154 typedef struct QCowHeader {
 155     uint32_t magic;
 156     uint32_t version;
 157     uint64_t backing_file_offset;
 158     uint32_t backing_file_size;
 159     uint32_t cluster_bits;
 160     uint64_t size; /* in bytes */
 161     uint32_t crypt_method;
 162     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 163     uint64_t l1_table_offset;
 164     uint64_t refcount_table_offset;
 165     uint32_t refcount_table_clusters;
 166     uint32_t nb_snapshots;
 167     uint64_t snapshots_offset;
 168
 169     /* The following fields are only valid for version >= 3 */
 170     uint64_t incompatible_features;
 171     uint64_t compatible_features;
 172     uint64_t autoclear_features;
 173
 174     uint32_t refcount_order;
 175     uint32_t header_length;
 176
 177     /* Additional fields */
 178     uint8_t compression_type;
 179
 180     /* header must be a multiple of 8 */
 181     uint8_t padding[7];
 182 } QEMU_PACKED QCowHeader;
 183
 184 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
 185
 186 typedef struct QEMU_PACKED QCowSnapshotHeader {
 187     /* header is 8 byte aligned */
 188     uint64_t l1_table_offset;
 189
 190     uint32_t l1_size;
 191     uint16_t id_str_size;
 192     uint16_t name_size;
 193
 194     uint32_t date_sec;
 195     uint32_t date_nsec;
 196
 197     uint64_t vm_clock_nsec;
 198
 199     uint32_t vm_state_size;
 200     uint32_t extra_data_size; /* for extension */
 201     /* extra data follows */
 202     /* id_str follows */
 203     /* name follows  */
 204 } QCowSnapshotHeader;
 205
 206 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 207     uint64_t vm_state_size_large;
 208     uint64_t disk_size;
 209     uint64_t icount;
 210 } QCowSnapshotExtraData;
 211
 212
 213 typedef struct QCowSnapshot {
 214     uint64_t l1_table_offset;
 215     uint32_t l1_size;
 216     char *id_str;
 217     char *name;
 218     uint64_t disk_size;
 219     uint64_t vm_state_size;
 220     uint32_t date_sec;
 221     uint32_t date_nsec;
 222     uint64_t vm_clock_nsec;
 223     /* icount value for the moment when snapshot was taken */
 224     uint64_t icount;
 225     /* Size of all extra data, including QCowSnapshotExtraData if available */
 226     uint32_t extra_data_size;
 227     /* Data beyond QCowSnapshotExtraData, if any */
 228     void *unknown_extra_data;
 229 } QCowSnapshot;
 230
 231 struct Qcow2Cache;
 232 typedef struct Qcow2Cache Qcow2Cache;
 233
 234 typedef struct Qcow2CryptoHeaderExtension {
 235     uint64_t offset;
 236     uint64_t length;
 237 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 238
 239 typedef struct Qcow2UnknownHeaderExtension {
 240     uint32_t magic;
 241     uint32_t len;
 242     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 243     uint8_t data[];
 244 } Qcow2UnknownHeaderExtension;
 245
 246 enum {
 247     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 248     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 249     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 250 };
 251
 252 /* Incompatible feature bits */
 253 enum {
 254     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 255     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 256     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 257     QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
 258     QCOW2_INCOMPAT_EXTL2_BITNR      = 4,
 259     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 260     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 261     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 262     QCOW2_INCOMPAT_COMPRESSION      = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
 263     QCOW2_INCOMPAT_EXTL2            = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
 264
 265     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 266                                     | QCOW2_INCOMPAT_CORRUPT
 267                                     | QCOW2_INCOMPAT_DATA_FILE
 268                                     | QCOW2_INCOMPAT_COMPRESSION
 269                                     | QCOW2_INCOMPAT_EXTL2,
 270 };
 271
 272 /* Compatible feature bits */
 273 enum {
 274     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 275     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 276
 277     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 278 };
 279
 280 /* Autoclear feature bits */
 281 enum {
 282     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 283     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 284     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 285     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 286
 287     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 288                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 289 };
 290
 291 enum qcow2_discard_type {
 292     QCOW2_DISCARD_NEVER = 0,
 293     QCOW2_DISCARD_ALWAYS,
 294     QCOW2_DISCARD_REQUEST,
 295     QCOW2_DISCARD_SNAPSHOT,
 296     QCOW2_DISCARD_OTHER,
 297     QCOW2_DISCARD_MAX
 298 };
 299
 300 typedef struct Qcow2Feature {
 301     uint8_t type;
 302     uint8_t bit;
 303     char    name[46];
 304 } QEMU_PACKED Qcow2Feature;
 305
 306 typedef struct Qcow2DiscardRegion {
 307     BlockDriverState *bs;
 308     uint64_t offset;
 309     uint64_t bytes;
 310     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 311 } Qcow2DiscardRegion;
 312
 313 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 314                                       uint64_t index);
 315 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 316                                   uint64_t index, uint64_t value);
 317
 318 typedef struct Qcow2BitmapHeaderExt {
 319     uint32_t nb_bitmaps;
 320     uint32_t reserved32;
 321     uint64_t bitmap_directory_size;
 322     uint64_t bitmap_directory_offset;
 323 } QEMU_PACKED Qcow2BitmapHeaderExt;
 324
 325 #define QCOW2_MAX_THREADS 4
 326
 327 typedef struct BDRVQcow2State {
 328     int cluster_bits;
 329     int cluster_size;
 330     int l2_slice_size;
 331     int subcluster_bits;
 332     int subcluster_size;
 333     int subclusters_per_cluster;
 334     int l2_bits;
 335     int l2_size;
 336     int l1_size;
 337     int l1_vm_state_index;
 338     int refcount_block_bits;
 339     int refcount_block_size;
 340     int csize_shift;
 341     int csize_mask;
 342     uint64_t cluster_offset_mask;
 343     uint64_t l1_table_offset;
 344     uint64_t *l1_table;
 345
 346     Qcow2Cache *l2_table_cache;
 347     Qcow2Cache *refcount_block_cache;
 348     QEMUTimer *cache_clean_timer;
 349     unsigned cache_clean_interval;
 350
 351     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 352
 353     uint64_t *refcount_table;
 354     uint64_t refcount_table_offset;
 355     uint32_t refcount_table_size;
 356     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 357     uint64_t free_cluster_index;
 358     uint64_t free_byte_offset;
 359
 360     CoMutex lock;
 361
 362     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 363     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 364     QCryptoBlock *crypto; /* Disk encryption format driver */
 365     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 366                                    for encryption initialization vector tweak */
 367     uint32_t crypt_method_header;
 368     uint64_t snapshots_offset;
 369     int snapshots_size;
 370     unsigned int nb_snapshots;
 371     QCowSnapshot *snapshots;
 372
 373     uint32_t nb_bitmaps;
 374     uint64_t bitmap_directory_size;
 375     uint64_t bitmap_directory_offset;
 376
 377     int flags;
 378     int qcow_version;
 379     bool use_lazy_refcounts;
 380     int refcount_order;
 381     int refcount_bits;
 382     uint64_t refcount_max;
 383
 384     Qcow2GetRefcountFunc *get_refcount;
 385     Qcow2SetRefcountFunc *set_refcount;
 386
 387     bool discard_passthrough[QCOW2_DISCARD_MAX];
 388
 389     bool discard_no_unref;
 390
 391     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 392     bool signaled_corruption;
 393
 394     uint64_t incompatible_features;
 395     uint64_t compatible_features;
 396     uint64_t autoclear_features;
 397
 398     size_t unknown_header_fields_size;
 399     void *unknown_header_fields;
 400     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 401     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 402     bool cache_discards;
 403
 404     /* Backing file path and format as stored in the image (this is not the
 405      * effective path/format, which may be the result of a runtime option
 406      * override) */
 407     char *image_backing_file;
 408     char *image_backing_format;
 409     char *image_data_file;
 410
 411     CoQueue thread_task_queue;
 412     int nb_threads;
 413
 414     BdrvChild *data_file;
 415
 416     bool metadata_preallocation_checked;
 417     bool metadata_preallocation;
 418     /*
 419      * Compression type used for the image. Default: 0 - ZLIB
 420      * The image compression type is set on image creation.
 421      * For now, the only way to change the compression type
 422      * is to convert the image with the desired compression type set.
 423      */
 424     Qcow2CompressionType compression_type;
 425 } BDRVQcow2State;
 426
 427 typedef struct Qcow2COWRegion {
 428     /**
 429      * Offset of the COW region in bytes from the start of the first cluster
 430      * touched by the request.
 431      */
 432     unsigned    offset;
 433
 434     /** Number of bytes to copy */
 435     unsigned    nb_bytes;
 436 } Qcow2COWRegion;
 437
 438 /**
 439  * Describes an in-flight (part of a) write request that writes to clusters
 440  * that need to have their L2 table entries updated (because they are
 441  * newly allocated or need changes in their L2 bitmaps)
 442  */
 443 typedef struct QCowL2Meta
 444 {
 445     /** Guest offset of the first updated cluster */
 446     uint64_t offset;
 447
 448     /** Host offset of the first updated cluster */
 449     uint64_t alloc_offset;
 450
 451     /** Number of updated clusters */
 452     int nb_clusters;
 453
 454     /** Do not free the old clusters */
 455     bool keep_old_clusters;
 456
 457     /**
 458      * Requests that overlap with this allocation and wait to be restarted
 459      * when the allocating request has completed.
 460      */
 461     CoQueue dependent_requests;
 462
 463     /**
 464      * The COW Region immediately before the area the guest actually
 465      * writes to. This (part of the) write request starts at
 466      * cow_start.offset + cow_start.nb_bytes.
 467      */
 468     Qcow2COWRegion cow_start;
 469
 470     /**
 471      * The COW Region immediately after the area the guest actually
 472      * writes to. This (part of the) write request ends at cow_end.offset
 473      * (which must always be set even when cow_end.nb_bytes is 0).
 474      */
 475     Qcow2COWRegion cow_end;
 476
 477     /*
 478      * Indicates that COW regions are already handled and do not require
 479      * any more processing.
 480      */
 481     bool skip_cow;
 482
 483     /**
 484      * Indicates that this is not a normal write request but a preallocation.
 485      * If the image has extended L2 entries this means that no new individual
 486      * subclusters will be marked as allocated in the L2 bitmap (but any
 487      * existing contents of that bitmap will be kept).
 488      */
 489     bool prealloc;
 490
 491     /**
 492      * The I/O vector with the data from the actual guest write request.
 493      * If non-NULL, this is meant to be merged together with the data
 494      * from @cow_start and @cow_end into one single write operation.
 495      */
 496     QEMUIOVector *data_qiov;
 497     size_t data_qiov_offset;
 498
 499     /** Pointer to next L2Meta of the same write request */
 500     struct QCowL2Meta *next;
 501
 502     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 503 } QCowL2Meta;
 504
 505 /*
 506  * In images with standard L2 entries all clusters are treated as if
 507  * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
 508  * can be mapped to each other and have the exact same meaning
 509  * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
 510  *
 511  * In images with extended L2 entries QCow2ClusterType refers to the
 512  * complete cluster and QCow2SubclusterType to each of the individual
 513  * subclusters, so there are several possible combinations:
 514  *
 515  *     |--------------+---------------------------|
 516  *     | Cluster type | Possible subcluster types |
 517  *     |--------------+---------------------------|
 518  *     | UNALLOCATED  |         UNALLOCATED_PLAIN |
 519  *     |              |                ZERO_PLAIN |
 520  *     |--------------+---------------------------|
 521  *     | NORMAL       |         UNALLOCATED_ALLOC |
 522  *     |              |                ZERO_ALLOC |
 523  *     |              |                    NORMAL |
 524  *     |--------------+---------------------------|
 525  *     | COMPRESSED   |                COMPRESSED |
 526  *     |--------------+---------------------------|
 527  *
 528  * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
 529  * the image should be marked corrupt.
 530  */
 531
 532 typedef enum QCow2ClusterType {
 533     QCOW2_CLUSTER_UNALLOCATED,
 534     QCOW2_CLUSTER_ZERO_PLAIN,
 535     QCOW2_CLUSTER_ZERO_ALLOC,
 536     QCOW2_CLUSTER_NORMAL,
 537     QCOW2_CLUSTER_COMPRESSED,
 538 } QCow2ClusterType;
 539
 540 typedef enum QCow2SubclusterType {
 541     QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
 542     QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
 543     QCOW2_SUBCLUSTER_ZERO_PLAIN,
 544     QCOW2_SUBCLUSTER_ZERO_ALLOC,
 545     QCOW2_SUBCLUSTER_NORMAL,
 546     QCOW2_SUBCLUSTER_COMPRESSED,
 547     QCOW2_SUBCLUSTER_INVALID,
 548 } QCow2SubclusterType;
 549
 550 typedef enum QCow2MetadataOverlap {
 551     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 552     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 553     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 554     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 555     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 556     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 557     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 558     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 559     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 560
 561     QCOW2_OL_MAX_BITNR              = 9,
 562
 563     QCOW2_OL_NONE             = 0,
 564     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 565     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 566     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 567     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 568     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 569     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 570     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 571     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 572      * reads. */
 573     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 574     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 575 } QCow2MetadataOverlap;
 576
 577 /* Perform all overlap checks which can be done in constant time */
 578 #define QCOW2_OL_CONSTANT \
 579     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 580      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 581
 582 /* Perform all overlap checks which don't require disk access */
 583 #define QCOW2_OL_CACHED \
 584     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 585      QCOW2_OL_INACTIVE_L1)
 586
 587 /* Perform all overlap checks */
 588 #define QCOW2_OL_ALL \
 589     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 590
 591 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 592 #define L1E_RESERVED_MASK 0x7f000000000001ffULL
 593 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 594 #define L2E_STD_RESERVED_MASK 0x3f000000000001feULL
 595
 596 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 597 #define REFT_RESERVED_MASK 0x1ffULL
 598
 599 #define INV_OFFSET (-1ULL)
 600
 601 static inline bool has_subclusters(BDRVQcow2State *s)
 602 {
 603     return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
 604 }
 605
 606 static inline size_t l2_entry_size(BDRVQcow2State *s)
 607 {
 608     return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
 609 }
 610
 611 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 612                                     int idx)
 613 {
 614     idx *= l2_entry_size(s) / sizeof(uint64_t);
 615     return be64_to_cpu(l2_slice[idx]);
 616 }
 617
 618 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 619                                      int idx)
 620 {
 621     if (has_subclusters(s)) {
 622         idx *= l2_entry_size(s) / sizeof(uint64_t);
 623         return be64_to_cpu(l2_slice[idx + 1]);
 624     } else {
 625         return 0; /* For convenience only; this value has no meaning. */
 626     }
 627 }
 628
 629 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 630                                 int idx, uint64_t entry)
 631 {
 632     idx *= l2_entry_size(s) / sizeof(uint64_t);
 633     l2_slice[idx] = cpu_to_be64(entry);
 634 }
 635
 636 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 637                                  int idx, uint64_t bitmap)
 638 {
 639     assert(has_subclusters(s));
 640     idx *= l2_entry_size(s) / sizeof(uint64_t);
 641     l2_slice[idx + 1] = cpu_to_be64(bitmap);
 642 }
 643
 644 static inline bool GRAPH_RDLOCK has_data_file(BlockDriverState *bs)
 645 {
 646     BDRVQcow2State *s = bs->opaque;
 647     return (s->data_file != bs->file);
 648 }
 649
 650 static inline bool data_file_is_raw(BlockDriverState *bs)
 651 {
 652     BDRVQcow2State *s = bs->opaque;
 653     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 654 }
 655
 656 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 657 {
 658     return offset & ~(s->cluster_size - 1);
 659 }
 660
 661 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 662 {
 663     return offset & (s->cluster_size - 1);
 664 }
 665
 666 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
 667 {
 668     return offset & (s->subcluster_size - 1);
 669 }
 670
 671 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 672 {
 673     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 674 }
 675
 676 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
 677 {
 678     return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
 679 }
 680
 681 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 682 {
 683     int shift = s->cluster_bits + s->l2_bits;
 684     return (size + (1ULL << shift) - 1) >> shift;
 685 }
 686
 687 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 688 {
 689     return offset >> (s->l2_bits + s->cluster_bits);
 690 }
 691
 692 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 693 {
 694     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 695 }
 696
 697 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 698 {
 699     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 700 }
 701
 702 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
 703 {
 704     return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
 705 }
 706
 707 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 708 {
 709     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 710 }
 711
 712 static inline QCow2ClusterType GRAPH_RDLOCK
 713 qcow2_get_cluster_type(BlockDriverState *bs, uint64_t l2_entry)
 714 {
 715     BDRVQcow2State *s = bs->opaque;
 716
 717     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 718         return QCOW2_CLUSTER_COMPRESSED;
 719     } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
 720         if (l2_entry & L2E_OFFSET_MASK) {
 721             return QCOW2_CLUSTER_ZERO_ALLOC;
 722         }
 723         return QCOW2_CLUSTER_ZERO_PLAIN;
 724     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 725         /* Offset 0 generally means unallocated, but it is ambiguous with
 726          * external data files because 0 is a valid offset there. However, all
 727          * clusters in external data files always have refcount 1, so we can
 728          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 729         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 730             return QCOW2_CLUSTER_NORMAL;
 731         } else {
 732             return QCOW2_CLUSTER_UNALLOCATED;
 733         }
 734     } else {
 735         return QCOW2_CLUSTER_NORMAL;
 736     }
 737 }
 738
 739 /*
 740  * In an image without subsclusters @l2_bitmap is ignored and
 741  * @sc_index must be 0.
 742  * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
 743  * (this checks the whole entry and bitmap, not only the bits related
 744  * to subcluster @sc_index).
 745  */
 746 static inline GRAPH_RDLOCK
 747 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
 748                                               uint64_t l2_entry,
 749                                               uint64_t l2_bitmap,
 750                                               unsigned sc_index)
 751 {
 752     BDRVQcow2State *s = bs->opaque;
 753     QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
 754     assert(sc_index < s->subclusters_per_cluster);
 755
 756     if (has_subclusters(s)) {
 757         switch (type) {
 758         case QCOW2_CLUSTER_COMPRESSED:
 759             return QCOW2_SUBCLUSTER_COMPRESSED;
 760         case QCOW2_CLUSTER_NORMAL:
 761             if ((l2_bitmap >> 32) & l2_bitmap) {
 762                 return QCOW2_SUBCLUSTER_INVALID;
 763             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 764                 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 765             } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
 766                 return QCOW2_SUBCLUSTER_NORMAL;
 767             } else {
 768                 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
 769             }
 770         case QCOW2_CLUSTER_UNALLOCATED:
 771             if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
 772                 return QCOW2_SUBCLUSTER_INVALID;
 773             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 774                 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 775             } else {
 776                 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 777             }
 778         default:
 779             g_assert_not_reached();
 780         }
 781     } else {
 782         switch (type) {
 783         case QCOW2_CLUSTER_COMPRESSED:
 784             return QCOW2_SUBCLUSTER_COMPRESSED;
 785         case QCOW2_CLUSTER_ZERO_PLAIN:
 786             return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 787         case QCOW2_CLUSTER_ZERO_ALLOC:
 788             return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 789         case QCOW2_CLUSTER_NORMAL:
 790             return QCOW2_SUBCLUSTER_NORMAL;
 791         case QCOW2_CLUSTER_UNALLOCATED:
 792             return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 793         default:
 794             g_assert_not_reached();
 795         }
 796     }
 797 }
 798
 799 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
 800 {
 801     return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
 802             type == QCOW2_CLUSTER_ZERO_ALLOC);
 803 }
 804
 805 /* Check whether refcounts are eager or lazy */
 806 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 807 {
 808     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 809 }
 810
 811 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 812 {
 813     return m->offset + m->cow_start.offset;
 814 }
 815
 816 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 817 {
 818     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 819 }
 820
 821 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 822 {
 823     return r1 > r2 ? r1 - r2 : r2 - r1;
 824 }
 825
 826 static inline
 827 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 828 {
 829     return offset >> (s->refcount_block_bits + s->cluster_bits);
 830 }
 831
 832 /* qcow2.c functions */
 833 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 834                                      int refcount_order, bool generous_increase,
 835                                      uint64_t *refblock_count);
 836
 837 int GRAPH_RDLOCK qcow2_mark_dirty(BlockDriverState *bs);
 838 int GRAPH_RDLOCK qcow2_mark_corrupt(BlockDriverState *bs);
 839 int GRAPH_RDLOCK qcow2_update_header(BlockDriverState *bs);
 840
 841 void GRAPH_RDLOCK
 842 qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 843                         int64_t size, const char *message_format, ...)
 844                         G_GNUC_PRINTF(5, 6);
 845
 846 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 847                          uint64_t entries, size_t entry_len,
 848                          int64_t max_size_bytes, const char *table_name,
 849                          Error **errp);
 850
 851 /* qcow2-refcount.c functions */
 852 int coroutine_fn GRAPH_RDLOCK qcow2_refcount_init(BlockDriverState *bs);
 853 void qcow2_refcount_close(BlockDriverState *bs);
 854
 855 int GRAPH_RDLOCK qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 856                                     uint64_t *refcount);
 857
 858 int GRAPH_RDLOCK
 859 qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 860                               uint64_t addend, bool decrease,
 861                               enum qcow2_discard_type type);
 862
 863 int64_t GRAPH_RDLOCK
 864 qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 865                     uint64_t additional_clusters, bool exact_size,
 866                     int new_refblock_index,
 867                     uint64_t new_refblock_offset);
 868
 869 int64_t GRAPH_RDLOCK
 870 qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 871
 872 int64_t GRAPH_RDLOCK coroutine_fn
 873 qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 874                         int64_t nb_clusters);
 875
 876 int64_t coroutine_fn GRAPH_RDLOCK qcow2_alloc_bytes(BlockDriverState *bs, int size);
 877 void GRAPH_RDLOCK qcow2_free_clusters(BlockDriverState *bs,
 878                                       int64_t offset, int64_t size,
 879                                       enum qcow2_discard_type type);
 880 void GRAPH_RDLOCK
 881 qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
 882                        enum qcow2_discard_type type);
 883
 884 int GRAPH_RDLOCK
 885 qcow2_update_snapshot_refcount(BlockDriverState *bs, int64_t l1_table_offset,
 886                                int l1_size, int addend);
 887
 888 int GRAPH_RDLOCK qcow2_flush_caches(BlockDriverState *bs);
 889 int GRAPH_RDLOCK qcow2_write_caches(BlockDriverState *bs);
 890 int coroutine_fn qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 891                                        BdrvCheckMode fix);
 892
 893 void GRAPH_RDLOCK qcow2_process_discards(BlockDriverState *bs, int ret);
 894
 895 int GRAPH_RDLOCK
 896 qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 897                              int64_t size);
 898 int GRAPH_RDLOCK
 899 qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 900                               int64_t size, bool data_file);
 901
 902 int coroutine_fn qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 903                                           void **refcount_table,
 904                                           int64_t *refcount_table_size,
 905                                           int64_t offset, int64_t size);
 906
 907 int GRAPH_RDLOCK
 908 qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 909                             BlockDriverAmendStatusCB *status_cb,
 910                             void *cb_opaque, Error **errp);
 911 int coroutine_fn GRAPH_RDLOCK qcow2_shrink_reftable(BlockDriverState *bs);
 912
 913 int64_t coroutine_fn GRAPH_RDLOCK
 914 qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 915
 916 int coroutine_fn GRAPH_RDLOCK
 917 qcow2_detect_metadata_preallocation(BlockDriverState *bs);
 918
 919 /* qcow2-cluster.c functions */
 920 int GRAPH_RDLOCK
 921 qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, bool exact_size);
 922
 923 int coroutine_fn GRAPH_RDLOCK
 924 qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 925
 926 int GRAPH_RDLOCK qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 927 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 928                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 929
 930 int GRAPH_RDLOCK
 931 qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
 932                       unsigned int *bytes, uint64_t *host_offset,
 933                       QCow2SubclusterType *subcluster_type);
 934
 935 int coroutine_fn GRAPH_RDLOCK
 936 qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
 937                         unsigned int *bytes, uint64_t *host_offset,
 938                         QCowL2Meta **m);
 939
 940 int coroutine_fn GRAPH_RDLOCK
 941 qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset,
 942                                       int compressed_size, uint64_t *host_offset);
 943 void GRAPH_RDLOCK
 944 qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry,
 945                                 uint64_t *coffset, int *csize);
 946
 947 int coroutine_fn GRAPH_RDLOCK
 948 qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 949
 950 void coroutine_fn GRAPH_RDLOCK
 951 qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 952
 953 int GRAPH_RDLOCK
 954 qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 955                       enum qcow2_discard_type type, bool full_discard);
 956
 957 int coroutine_fn GRAPH_RDLOCK
 958 qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
 959                          int flags);
 960
 961 int GRAPH_RDLOCK
 962 qcow2_expand_zero_clusters(BlockDriverState *bs,
 963                            BlockDriverAmendStatusCB *status_cb,
 964                            void *cb_opaque);
 965
 966 /* qcow2-snapshot.c functions */
 967 int GRAPH_RDLOCK
 968 qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 969
 970 int GRAPH_RDLOCK
 971 qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 972
 973 int GRAPH_RDLOCK
 974 qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id,
 975                           const char *name, Error **errp);
 976
 977 int GRAPH_RDLOCK
 978 qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 979
 980 int GRAPH_RDLOCK
 981 qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_id,
 982                         const char *name, Error **errp);
 983
 984 void qcow2_free_snapshots(BlockDriverState *bs);
 985 int coroutine_fn GRAPH_RDLOCK
 986 qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
 987 int GRAPH_RDLOCK qcow2_write_snapshots(BlockDriverState *bs);
 988
 989 int coroutine_fn GRAPH_RDLOCK
 990 qcow2_check_read_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
 991                                 BdrvCheckMode fix);
 992
 993 int coroutine_fn GRAPH_RDLOCK
 994 qcow2_check_fix_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
 995                                BdrvCheckMode fix);
 996
 997 /* qcow2-cache.c functions */
 998 Qcow2Cache * GRAPH_RDLOCK
 999 qcow2_cache_create(BlockDriverState *bs, int num_tables, unsigned table_size);
1000
1001 int qcow2_cache_destroy(Qcow2Cache *c);
1002
1003 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
1004 int GRAPH_RDLOCK qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
1005 int GRAPH_RDLOCK qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
1006 int GRAPH_RDLOCK qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
1007                                             Qcow2Cache *dependency);
1008 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
1009
1010 void qcow2_cache_clean_unused(Qcow2Cache *c);
1011 int GRAPH_RDLOCK qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
1012
1013 int GRAPH_RDLOCK
1014 qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
1015                 void **table);
1016
1017 int GRAPH_RDLOCK
1018 qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
1019                       void **table);
1020
1021 void qcow2_cache_put(Qcow2Cache *c, void **table);
1022 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
1023 void qcow2_cache_discard(Qcow2Cache *c, void *table);
1024
1025 /* qcow2-bitmap.c functions */
1026 int coroutine_fn GRAPH_RDLOCK
1027 qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
1028                               void **refcount_table,
1029                               int64_t *refcount_table_size);
1030
1031 bool coroutine_fn GRAPH_RDLOCK
1032 qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated,
1033                          Error **errp);
1034
1035 bool GRAPH_RDLOCK
1036 qcow2_get_bitmap_info_list(BlockDriverState *bs,
1037                            Qcow2BitmapInfoList **info_list, Error **errp);
1038
1039 int GRAPH_RDLOCK qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
1040 int GRAPH_RDLOCK qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
1041
1042 int coroutine_fn GRAPH_RDLOCK
1043 qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
1044
1045 bool GRAPH_RDLOCK
1046 qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, bool release_stored,
1047                                      Error **errp);
1048
1049 bool coroutine_fn GRAPH_RDLOCK
1050 qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
1051                                     uint32_t granularity, Error **errp);
1052
1053 int coroutine_fn GRAPH_RDLOCK
1054 qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
1055                                         Error **errp);
1056
1057 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
1058 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
1059                                                 uint32_t cluster_size);
1060
1061 ssize_t coroutine_fn
1062 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
1063                   const void *src, size_t src_size);
1064 ssize_t coroutine_fn
1065 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
1066                     const void *src, size_t src_size);
1067 int coroutine_fn
1068 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
1069                  uint64_t guest_offset, void *buf, size_t len);
1070 int coroutine_fn
1071 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
1072                  uint64_t guest_offset, void *buf, size_t len);
1073
1074 #endif