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 /* Bitmap header extension constraints */
  65 #define QCOW2_MAX_BITMAPS 65535
  66 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  67
  68 /* indicate that the refcount of the referenced cluster is exactly one. */
  69 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  70 /* indicate that the cluster is compressed (they never have the copied flag) */
  71 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  72 /* The cluster reads as all zeros */
  73 #define QCOW_OFLAG_ZERO (1ULL << 0)
  74
  75 #define MIN_CLUSTER_BITS 9
  76 #define MAX_CLUSTER_BITS 21
  77
  78 /* Defined in the qcow2 spec (compressed cluster descriptor) */
  79 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
  80 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1))
  81
  82 /* Must be at least 2 to cover COW */
  83 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
  84
  85 /* Must be at least 4 to cover all cases of refcount table growth */
  86 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  87
  88 #ifdef CONFIG_LINUX
  89 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
  90 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
  91 #else
  92 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
  93 /* Cache clean interval is currently available only on Linux, so must be 0 */
  94 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
  95 #endif
  96
  97 #define DEFAULT_CLUSTER_SIZE 65536
  98
  99 #define QCOW2_OPT_DATA_FILE "data-file"
 100 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 101 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 102 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
 103 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
 104 #define QCOW2_OPT_OVERLAP "overlap-check"
 105 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 106 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 107 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 108 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 109 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 110 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 111 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 112 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 113 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 114 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 115 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 116 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 117 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 118 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 119 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 120
 121 typedef struct QCowHeader {
 122     uint32_t magic;
 123     uint32_t version;
 124     uint64_t backing_file_offset;
 125     uint32_t backing_file_size;
 126     uint32_t cluster_bits;
 127     uint64_t size; /* in bytes */
 128     uint32_t crypt_method;
 129     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 130     uint64_t l1_table_offset;
 131     uint64_t refcount_table_offset;
 132     uint32_t refcount_table_clusters;
 133     uint32_t nb_snapshots;
 134     uint64_t snapshots_offset;
 135
 136     /* The following fields are only valid for version >= 3 */
 137     uint64_t incompatible_features;
 138     uint64_t compatible_features;
 139     uint64_t autoclear_features;
 140
 141     uint32_t refcount_order;
 142     uint32_t header_length;
 143 } QEMU_PACKED QCowHeader;
 144
 145 typedef struct QEMU_PACKED QCowSnapshotHeader {
 146     /* header is 8 byte aligned */
 147     uint64_t l1_table_offset;
 148
 149     uint32_t l1_size;
 150     uint16_t id_str_size;
 151     uint16_t name_size;
 152
 153     uint32_t date_sec;
 154     uint32_t date_nsec;
 155
 156     uint64_t vm_clock_nsec;
 157
 158     uint32_t vm_state_size;
 159     uint32_t extra_data_size; /* for extension */
 160     /* extra data follows */
 161     /* id_str follows */
 162     /* name follows  */
 163 } QCowSnapshotHeader;
 164
 165 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 166     uint64_t vm_state_size_large;
 167     uint64_t disk_size;
 168 } QCowSnapshotExtraData;
 169
 170
 171 typedef struct QCowSnapshot {
 172     uint64_t l1_table_offset;
 173     uint32_t l1_size;
 174     char *id_str;
 175     char *name;
 176     uint64_t disk_size;
 177     uint64_t vm_state_size;
 178     uint32_t date_sec;
 179     uint32_t date_nsec;
 180     uint64_t vm_clock_nsec;
 181 } QCowSnapshot;
 182
 183 struct Qcow2Cache;
 184 typedef struct Qcow2Cache Qcow2Cache;
 185
 186 typedef struct Qcow2CryptoHeaderExtension {
 187     uint64_t offset;
 188     uint64_t length;
 189 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 190
 191 typedef struct Qcow2UnknownHeaderExtension {
 192     uint32_t magic;
 193     uint32_t len;
 194     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 195     uint8_t data[];
 196 } Qcow2UnknownHeaderExtension;
 197
 198 enum {
 199     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 200     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 201     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 202 };
 203
 204 /* Incompatible feature bits */
 205 enum {
 206     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 207     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 208     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 209     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 210     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 211     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 212
 213     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 214                                     | QCOW2_INCOMPAT_CORRUPT
 215                                     | QCOW2_INCOMPAT_DATA_FILE,
 216 };
 217
 218 /* Compatible feature bits */
 219 enum {
 220     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 221     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 222
 223     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 224 };
 225
 226 /* Autoclear feature bits */
 227 enum {
 228     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 229     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 230     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 231     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 232
 233     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 234                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 235 };
 236
 237 enum qcow2_discard_type {
 238     QCOW2_DISCARD_NEVER = 0,
 239     QCOW2_DISCARD_ALWAYS,
 240     QCOW2_DISCARD_REQUEST,
 241     QCOW2_DISCARD_SNAPSHOT,
 242     QCOW2_DISCARD_OTHER,
 243     QCOW2_DISCARD_MAX
 244 };
 245
 246 typedef struct Qcow2Feature {
 247     uint8_t type;
 248     uint8_t bit;
 249     char    name[46];
 250 } QEMU_PACKED Qcow2Feature;
 251
 252 typedef struct Qcow2DiscardRegion {
 253     BlockDriverState *bs;
 254     uint64_t offset;
 255     uint64_t bytes;
 256     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 257 } Qcow2DiscardRegion;
 258
 259 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 260                                       uint64_t index);
 261 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 262                                   uint64_t index, uint64_t value);
 263
 264 typedef struct Qcow2BitmapHeaderExt {
 265     uint32_t nb_bitmaps;
 266     uint32_t reserved32;
 267     uint64_t bitmap_directory_size;
 268     uint64_t bitmap_directory_offset;
 269 } QEMU_PACKED Qcow2BitmapHeaderExt;
 270
 271 #define QCOW2_MAX_THREADS 4
 272
 273 typedef struct BDRVQcow2State {
 274     int cluster_bits;
 275     int cluster_size;
 276     int l2_slice_size;
 277     int l2_bits;
 278     int l2_size;
 279     int l1_size;
 280     int l1_vm_state_index;
 281     int refcount_block_bits;
 282     int refcount_block_size;
 283     int csize_shift;
 284     int csize_mask;
 285     uint64_t cluster_offset_mask;
 286     uint64_t l1_table_offset;
 287     uint64_t *l1_table;
 288
 289     Qcow2Cache* l2_table_cache;
 290     Qcow2Cache* refcount_block_cache;
 291     QEMUTimer *cache_clean_timer;
 292     unsigned cache_clean_interval;
 293
 294     uint8_t *cluster_cache;
 295     uint8_t *cluster_data;
 296     uint64_t cluster_cache_offset;
 297     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 298
 299     uint64_t *refcount_table;
 300     uint64_t refcount_table_offset;
 301     uint32_t refcount_table_size;
 302     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 303     uint64_t free_cluster_index;
 304     uint64_t free_byte_offset;
 305
 306     CoMutex lock;
 307
 308     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 309     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 310     QCryptoBlock *crypto; /* Disk encryption format driver */
 311     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 312                                    for encryption initialization vector tweak */
 313     uint32_t crypt_method_header;
 314     uint64_t snapshots_offset;
 315     int snapshots_size;
 316     unsigned int nb_snapshots;
 317     QCowSnapshot *snapshots;
 318
 319     uint32_t nb_bitmaps;
 320     uint64_t bitmap_directory_size;
 321     uint64_t bitmap_directory_offset;
 322
 323     int flags;
 324     int qcow_version;
 325     bool use_lazy_refcounts;
 326     int refcount_order;
 327     int refcount_bits;
 328     uint64_t refcount_max;
 329
 330     Qcow2GetRefcountFunc *get_refcount;
 331     Qcow2SetRefcountFunc *set_refcount;
 332
 333     bool discard_passthrough[QCOW2_DISCARD_MAX];
 334
 335     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 336     bool signaled_corruption;
 337
 338     uint64_t incompatible_features;
 339     uint64_t compatible_features;
 340     uint64_t autoclear_features;
 341
 342     size_t unknown_header_fields_size;
 343     void* unknown_header_fields;
 344     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 345     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 346     bool cache_discards;
 347
 348     /* Backing file path and format as stored in the image (this is not the
 349      * effective path/format, which may be the result of a runtime option
 350      * override) */
 351     char *image_backing_file;
 352     char *image_backing_format;
 353     char *image_data_file;
 354
 355     CoQueue thread_task_queue;
 356     int nb_threads;
 357
 358     BdrvChild *data_file;
 359
 360     bool metadata_preallocation_checked;
 361     bool metadata_preallocation;
 362 } BDRVQcow2State;
 363
 364 typedef struct Qcow2COWRegion {
 365     /**
 366      * Offset of the COW region in bytes from the start of the first cluster
 367      * touched by the request.
 368      */
 369     unsigned    offset;
 370
 371     /** Number of bytes to copy */
 372     unsigned    nb_bytes;
 373 } Qcow2COWRegion;
 374
 375 /**
 376  * Describes an in-flight (part of a) write request that writes to clusters
 377  * that are not referenced in their L2 table yet.
 378  */
 379 typedef struct QCowL2Meta
 380 {
 381     /** Guest offset of the first newly allocated cluster */
 382     uint64_t offset;
 383
 384     /** Host offset of the first newly allocated cluster */
 385     uint64_t alloc_offset;
 386
 387     /** Number of newly allocated clusters */
 388     int nb_clusters;
 389
 390     /** Do not free the old clusters */
 391     bool keep_old_clusters;
 392
 393     /**
 394      * Requests that overlap with this allocation and wait to be restarted
 395      * when the allocating request has completed.
 396      */
 397     CoQueue dependent_requests;
 398
 399     /**
 400      * The COW Region between the start of the first allocated cluster and the
 401      * area the guest actually writes to.
 402      */
 403     Qcow2COWRegion cow_start;
 404
 405     /**
 406      * The COW Region between the area the guest actually writes to and the
 407      * end of the last allocated cluster.
 408      */
 409     Qcow2COWRegion cow_end;
 410
 411     /*
 412      * Indicates that COW regions are already handled and do not require
 413      * any more processing.
 414      */
 415     bool skip_cow;
 416
 417     /**
 418      * The I/O vector with the data from the actual guest write request.
 419      * If non-NULL, this is meant to be merged together with the data
 420      * from @cow_start and @cow_end into one single write operation.
 421      */
 422     QEMUIOVector *data_qiov;
 423
 424     /** Pointer to next L2Meta of the same write request */
 425     struct QCowL2Meta *next;
 426
 427     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 428 } QCowL2Meta;
 429
 430 typedef enum QCow2ClusterType {
 431     QCOW2_CLUSTER_UNALLOCATED,
 432     QCOW2_CLUSTER_ZERO_PLAIN,
 433     QCOW2_CLUSTER_ZERO_ALLOC,
 434     QCOW2_CLUSTER_NORMAL,
 435     QCOW2_CLUSTER_COMPRESSED,
 436 } QCow2ClusterType;
 437
 438 typedef enum QCow2MetadataOverlap {
 439     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 440     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 441     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 442     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 443     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 444     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 445     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 446     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 447     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 448
 449     QCOW2_OL_MAX_BITNR              = 9,
 450
 451     QCOW2_OL_NONE             = 0,
 452     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 453     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 454     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 455     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 456     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 457     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 458     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 459     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 460      * reads. */
 461     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 462     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 463 } QCow2MetadataOverlap;
 464
 465 /* Perform all overlap checks which can be done in constant time */
 466 #define QCOW2_OL_CONSTANT \
 467     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 468      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 469
 470 /* Perform all overlap checks which don't require disk access */
 471 #define QCOW2_OL_CACHED \
 472     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 473      QCOW2_OL_INACTIVE_L1)
 474
 475 /* Perform all overlap checks */
 476 #define QCOW2_OL_ALL \
 477     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 478
 479 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 480 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 481 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 482
 483 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 484
 485 #define INV_OFFSET (-1ULL)
 486
 487 static inline bool has_data_file(BlockDriverState *bs)
 488 {
 489     BDRVQcow2State *s = bs->opaque;
 490     return (s->data_file != bs->file);
 491 }
 492
 493 static inline bool data_file_is_raw(BlockDriverState *bs)
 494 {
 495     BDRVQcow2State *s = bs->opaque;
 496     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 497 }
 498
 499 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 500 {
 501     return offset & ~(s->cluster_size - 1);
 502 }
 503
 504 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 505 {
 506     return offset & (s->cluster_size - 1);
 507 }
 508
 509 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 510 {
 511     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 512 }
 513
 514 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 515 {
 516     int shift = s->cluster_bits + s->l2_bits;
 517     return (size + (1ULL << shift) - 1) >> shift;
 518 }
 519
 520 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 521 {
 522     return offset >> (s->l2_bits + s->cluster_bits);
 523 }
 524
 525 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 526 {
 527     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 528 }
 529
 530 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 531 {
 532     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 533 }
 534
 535 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 536 {
 537     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 538 }
 539
 540 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 541                                                       uint64_t l2_entry)
 542 {
 543     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 544         return QCOW2_CLUSTER_COMPRESSED;
 545     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 546         if (l2_entry & L2E_OFFSET_MASK) {
 547             return QCOW2_CLUSTER_ZERO_ALLOC;
 548         }
 549         return QCOW2_CLUSTER_ZERO_PLAIN;
 550     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 551         /* Offset 0 generally means unallocated, but it is ambiguous with
 552          * external data files because 0 is a valid offset there. However, all
 553          * clusters in external data files always have refcount 1, so we can
 554          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 555         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 556             return QCOW2_CLUSTER_NORMAL;
 557         } else {
 558             return QCOW2_CLUSTER_UNALLOCATED;
 559         }
 560     } else {
 561         return QCOW2_CLUSTER_NORMAL;
 562     }
 563 }
 564
 565 /* Check whether refcounts are eager or lazy */
 566 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 567 {
 568     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 569 }
 570
 571 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 572 {
 573     return m->offset + m->cow_start.offset;
 574 }
 575
 576 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 577 {
 578     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 579 }
 580
 581 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 582 {
 583     return r1 > r2 ? r1 - r2 : r2 - r1;
 584 }
 585
 586 static inline
 587 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 588 {
 589     return offset >> (s->refcount_block_bits + s->cluster_bits);
 590 }
 591
 592 /* qcow2.c functions */
 593 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 594                                      int refcount_order, bool generous_increase,
 595                                      uint64_t *refblock_count);
 596
 597 int qcow2_mark_dirty(BlockDriverState *bs);
 598 int qcow2_mark_corrupt(BlockDriverState *bs);
 599 int qcow2_mark_consistent(BlockDriverState *bs);
 600 int qcow2_update_header(BlockDriverState *bs);
 601
 602 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 603                              int64_t size, const char *message_format, ...)
 604                              GCC_FMT_ATTR(5, 6);
 605
 606 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 607                          uint64_t entries, size_t entry_len,
 608                          int64_t max_size_bytes, const char *table_name,
 609                          Error **errp);
 610
 611 /* qcow2-refcount.c functions */
 612 int qcow2_refcount_init(BlockDriverState *bs);
 613 void qcow2_refcount_close(BlockDriverState *bs);
 614
 615 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 616                        uint64_t *refcount);
 617
 618 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 619                                   uint64_t addend, bool decrease,
 620                                   enum qcow2_discard_type type);
 621
 622 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 623                             uint64_t additional_clusters, bool exact_size,
 624                             int new_refblock_index,
 625                             uint64_t new_refblock_offset);
 626
 627 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 628 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 629                                 int64_t nb_clusters);
 630 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 631 void qcow2_free_clusters(BlockDriverState *bs,
 632                           int64_t offset, int64_t size,
 633                           enum qcow2_discard_type type);
 634 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 635                              int nb_clusters, enum qcow2_discard_type type);
 636
 637 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 638     int64_t l1_table_offset, int l1_size, int addend);
 639
 640 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 641 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 642 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 643                           BdrvCheckMode fix);
 644
 645 void qcow2_process_discards(BlockDriverState *bs, int ret);
 646
 647 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 648                                  int64_t size);
 649 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 650                                   int64_t size, bool data_file);
 651 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 652                              void **refcount_table,
 653                              int64_t *refcount_table_size,
 654                              int64_t offset, int64_t size);
 655
 656 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 657                                 BlockDriverAmendStatusCB *status_cb,
 658                                 void *cb_opaque, Error **errp);
 659 int qcow2_shrink_reftable(BlockDriverState *bs);
 660 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 661 int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
 662
 663 /* qcow2-cluster.c functions */
 664 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 665                         bool exact_size);
 666 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 667 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 668 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 669                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 670
 671 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 672                              unsigned int *bytes, uint64_t *cluster_offset);
 673 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 674                                unsigned int *bytes, uint64_t *host_offset,
 675                                QCowL2Meta **m);
 676 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 677                                           uint64_t offset,
 678                                           int compressed_size,
 679                                           uint64_t *host_offset);
 680
 681 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 682 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 683 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 684                           uint64_t bytes, enum qcow2_discard_type type,
 685                           bool full_discard);
 686 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 687                           uint64_t bytes, int flags);
 688
 689 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 690                                BlockDriverAmendStatusCB *status_cb,
 691                                void *cb_opaque);
 692
 693 /* qcow2-snapshot.c functions */
 694 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 695 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 696 int qcow2_snapshot_delete(BlockDriverState *bs,
 697                           const char *snapshot_id,
 698                           const char *name,
 699                           Error **errp);
 700 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 701 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 702                             const char *snapshot_id,
 703                             const char *name,
 704                             Error **errp);
 705
 706 void qcow2_free_snapshots(BlockDriverState *bs);
 707 int qcow2_read_snapshots(BlockDriverState *bs);
 708
 709 /* qcow2-cache.c functions */
 710 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 711                                unsigned table_size);
 712 int qcow2_cache_destroy(Qcow2Cache *c);
 713
 714 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 715 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 716 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 717 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 718     Qcow2Cache *dependency);
 719 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 720
 721 void qcow2_cache_clean_unused(Qcow2Cache *c);
 722 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 723
 724 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 725     void **table);
 726 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 727     void **table);
 728 void qcow2_cache_put(Qcow2Cache *c, void **table);
 729 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 730 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 731
 732 /* qcow2-bitmap.c functions */
 733 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 734                                   void **refcount_table,
 735                                   int64_t *refcount_table_size);
 736 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 737 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
 738                                                 Error **errp);
 739 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
 740                                  Error **errp);
 741 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 742 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
 743 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 744 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 745 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 746                                       const char *name,
 747                                       uint32_t granularity,
 748                                       Error **errp);
 749 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 750                                           const char *name,
 751                                           Error **errp);
 752
 753 ssize_t coroutine_fn
 754 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
 755                   const void *src, size_t src_size);
 756 ssize_t coroutine_fn
 757 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
 758                     const void *src, size_t src_size);
 759 int coroutine_fn
 760 qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
 761                  uint64_t offset, void *buf, size_t len);
 762 int coroutine_fn
 763 qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
 764                  uint64_t offset, void *buf, size_t len);
 765
 766 #endif