block/qcow2.h

   1 /*
   2  * Block driver for the QCOW version 2 format
   3  *
   4  * Copyright (c) 2004-2006 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #ifndef BLOCK_QCOW2_H
  26 #define BLOCK_QCOW2_H
  27
  28 #include "crypto/block.h"
  29 #include "qemu/coroutine.h"
  30 #include "qemu/units.h"
  31
  32 //#define DEBUG_ALLOC
  33 //#define DEBUG_ALLOC2
  34 //#define DEBUG_EXT
  35
  36 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
  37
  38 #define QCOW_CRYPT_NONE 0
  39 #define QCOW_CRYPT_AES  1
  40 #define QCOW_CRYPT_LUKS 2
  41
  42 #define QCOW_MAX_CRYPT_CLUSTERS 32
  43 #define QCOW_MAX_SNAPSHOTS 65536
  44
  45 /* Field widths in qcow2 mean normal cluster offsets cannot reach
  46  * 64PB; depending on cluster size, compressed clusters can have a
  47  * smaller limit (64PB for up to 16k clusters, then ramps down to
  48  * 512TB for 2M clusters).  */
  49 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
  50
  51 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
  52  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  53 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
  54
  55 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
  56  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
  57 #define QCOW_MAX_L1_SIZE (32 * MiB)
  58
  59 /* Allow for an average of 1k per snapshot table entry, should be plenty of
  60  * space for snapshot names and IDs */
  61 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
  62
  63 /* Bitmap header extension constraints */
  64 #define QCOW2_MAX_BITMAPS 65535
  65 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
  66
  67 /* indicate that the refcount of the referenced cluster is exactly one. */
  68 #define QCOW_OFLAG_COPIED     (1ULL << 63)
  69 /* indicate that the cluster is compressed (they never have the copied flag) */
  70 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
  71 /* The cluster reads as all zeros */
  72 #define QCOW_OFLAG_ZERO (1ULL << 0)
  73
  74 #define MIN_CLUSTER_BITS 9
  75 #define MAX_CLUSTER_BITS 21
  76
  77 /* Defined in the qcow2 spec (compressed cluster descriptor) */
  78 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
  79 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1))
  80
  81 /* Must be at least 2 to cover COW */
  82 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
  83
  84 /* Must be at least 4 to cover all cases of refcount table growth */
  85 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
  86
  87 #ifdef CONFIG_LINUX
  88 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
  89 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
  90 #else
  91 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
  92 /* Cache clean interval is currently available only on Linux, so must be 0 */
  93 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
  94 #endif
  95
  96 #define DEFAULT_CLUSTER_SIZE 65536
  97
  98 #define QCOW2_OPT_DATA_FILE "data-file"
  99 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 100 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 101 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
 102 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
 103 #define QCOW2_OPT_OVERLAP "overlap-check"
 104 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 105 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 106 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 107 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 108 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 109 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 110 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 111 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 112 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 113 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 114 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 115 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 116 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 117 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 118 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 119
 120 typedef struct QCowHeader {
 121     uint32_t magic;
 122     uint32_t version;
 123     uint64_t backing_file_offset;
 124     uint32_t backing_file_size;
 125     uint32_t cluster_bits;
 126     uint64_t size; /* in bytes */
 127     uint32_t crypt_method;
 128     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 129     uint64_t l1_table_offset;
 130     uint64_t refcount_table_offset;
 131     uint32_t refcount_table_clusters;
 132     uint32_t nb_snapshots;
 133     uint64_t snapshots_offset;
 134
 135     /* The following fields are only valid for version >= 3 */
 136     uint64_t incompatible_features;
 137     uint64_t compatible_features;
 138     uint64_t autoclear_features;
 139
 140     uint32_t refcount_order;
 141     uint32_t header_length;
 142 } QEMU_PACKED QCowHeader;
 143
 144 typedef struct QEMU_PACKED QCowSnapshotHeader {
 145     /* header is 8 byte aligned */
 146     uint64_t l1_table_offset;
 147
 148     uint32_t l1_size;
 149     uint16_t id_str_size;
 150     uint16_t name_size;
 151
 152     uint32_t date_sec;
 153     uint32_t date_nsec;
 154
 155     uint64_t vm_clock_nsec;
 156
 157     uint32_t vm_state_size;
 158     uint32_t extra_data_size; /* for extension */
 159     /* extra data follows */
 160     /* id_str follows */
 161     /* name follows  */
 162 } QCowSnapshotHeader;
 163
 164 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 165     uint64_t vm_state_size_large;
 166     uint64_t disk_size;
 167 } QCowSnapshotExtraData;
 168
 169
 170 typedef struct QCowSnapshot {
 171     uint64_t l1_table_offset;
 172     uint32_t l1_size;
 173     char *id_str;
 174     char *name;
 175     uint64_t disk_size;
 176     uint64_t vm_state_size;
 177     uint32_t date_sec;
 178     uint32_t date_nsec;
 179     uint64_t vm_clock_nsec;
 180 } QCowSnapshot;
 181
 182 struct Qcow2Cache;
 183 typedef struct Qcow2Cache Qcow2Cache;
 184
 185 typedef struct Qcow2CryptoHeaderExtension {
 186     uint64_t offset;
 187     uint64_t length;
 188 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 189
 190 typedef struct Qcow2UnknownHeaderExtension {
 191     uint32_t magic;
 192     uint32_t len;
 193     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 194     uint8_t data[];
 195 } Qcow2UnknownHeaderExtension;
 196
 197 enum {
 198     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 199     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 200     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 201 };
 202
 203 /* Incompatible feature bits */
 204 enum {
 205     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 206     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 207     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 208     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 209     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 210     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 211
 212     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 213                                     | QCOW2_INCOMPAT_CORRUPT
 214                                     | QCOW2_INCOMPAT_DATA_FILE,
 215 };
 216
 217 /* Compatible feature bits */
 218 enum {
 219     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 220     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 221
 222     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 223 };
 224
 225 /* Autoclear feature bits */
 226 enum {
 227     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 228     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 229     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 230     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 231
 232     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 233                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 234 };
 235
 236 enum qcow2_discard_type {
 237     QCOW2_DISCARD_NEVER = 0,
 238     QCOW2_DISCARD_ALWAYS,
 239     QCOW2_DISCARD_REQUEST,
 240     QCOW2_DISCARD_SNAPSHOT,
 241     QCOW2_DISCARD_OTHER,
 242     QCOW2_DISCARD_MAX
 243 };
 244
 245 typedef struct Qcow2Feature {
 246     uint8_t type;
 247     uint8_t bit;
 248     char    name[46];
 249 } QEMU_PACKED Qcow2Feature;
 250
 251 typedef struct Qcow2DiscardRegion {
 252     BlockDriverState *bs;
 253     uint64_t offset;
 254     uint64_t bytes;
 255     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 256 } Qcow2DiscardRegion;
 257
 258 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 259                                       uint64_t index);
 260 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 261                                   uint64_t index, uint64_t value);
 262
 263 typedef struct Qcow2BitmapHeaderExt {
 264     uint32_t nb_bitmaps;
 265     uint32_t reserved32;
 266     uint64_t bitmap_directory_size;
 267     uint64_t bitmap_directory_offset;
 268 } QEMU_PACKED Qcow2BitmapHeaderExt;
 269
 270 typedef struct BDRVQcow2State {
 271     int cluster_bits;
 272     int cluster_size;
 273     int l2_slice_size;
 274     int l2_bits;
 275     int l2_size;
 276     int l1_size;
 277     int l1_vm_state_index;
 278     int refcount_block_bits;
 279     int refcount_block_size;
 280     int csize_shift;
 281     int csize_mask;
 282     uint64_t cluster_offset_mask;
 283     uint64_t l1_table_offset;
 284     uint64_t *l1_table;
 285
 286     Qcow2Cache* l2_table_cache;
 287     Qcow2Cache* refcount_block_cache;
 288     QEMUTimer *cache_clean_timer;
 289     unsigned cache_clean_interval;
 290
 291     uint8_t *cluster_cache;
 292     uint8_t *cluster_data;
 293     uint64_t cluster_cache_offset;
 294     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 295
 296     uint64_t *refcount_table;
 297     uint64_t refcount_table_offset;
 298     uint32_t refcount_table_size;
 299     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 300     uint64_t free_cluster_index;
 301     uint64_t free_byte_offset;
 302
 303     CoMutex lock;
 304
 305     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 306     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 307     QCryptoBlock *crypto; /* Disk encryption format driver */
 308     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 309                                    for encryption initialization vector tweak */
 310     uint32_t crypt_method_header;
 311     uint64_t snapshots_offset;
 312     int snapshots_size;
 313     unsigned int nb_snapshots;
 314     QCowSnapshot *snapshots;
 315
 316     uint32_t nb_bitmaps;
 317     uint64_t bitmap_directory_size;
 318     uint64_t bitmap_directory_offset;
 319
 320     int flags;
 321     int qcow_version;
 322     bool use_lazy_refcounts;
 323     int refcount_order;
 324     int refcount_bits;
 325     uint64_t refcount_max;
 326
 327     Qcow2GetRefcountFunc *get_refcount;
 328     Qcow2SetRefcountFunc *set_refcount;
 329
 330     bool discard_passthrough[QCOW2_DISCARD_MAX];
 331
 332     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 333     bool signaled_corruption;
 334
 335     uint64_t incompatible_features;
 336     uint64_t compatible_features;
 337     uint64_t autoclear_features;
 338
 339     size_t unknown_header_fields_size;
 340     void* unknown_header_fields;
 341     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 342     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 343     bool cache_discards;
 344
 345     /* Backing file path and format as stored in the image (this is not the
 346      * effective path/format, which may be the result of a runtime option
 347      * override) */
 348     char *image_backing_file;
 349     char *image_backing_format;
 350     char *image_data_file;
 351
 352     CoQueue compress_wait_queue;
 353     int nb_compress_threads;
 354
 355     BdrvChild *data_file;
 356 } BDRVQcow2State;
 357
 358 typedef struct Qcow2COWRegion {
 359     /**
 360      * Offset of the COW region in bytes from the start of the first cluster
 361      * touched by the request.
 362      */
 363     unsigned    offset;
 364
 365     /** Number of bytes to copy */
 366     unsigned    nb_bytes;
 367 } Qcow2COWRegion;
 368
 369 /**
 370  * Describes an in-flight (part of a) write request that writes to clusters
 371  * that are not referenced in their L2 table yet.
 372  */
 373 typedef struct QCowL2Meta
 374 {
 375     /** Guest offset of the first newly allocated cluster */
 376     uint64_t offset;
 377
 378     /** Host offset of the first newly allocated cluster */
 379     uint64_t alloc_offset;
 380
 381     /** Number of newly allocated clusters */
 382     int nb_clusters;
 383
 384     /** Do not free the old clusters */
 385     bool keep_old_clusters;
 386
 387     /**
 388      * Requests that overlap with this allocation and wait to be restarted
 389      * when the allocating request has completed.
 390      */
 391     CoQueue dependent_requests;
 392
 393     /**
 394      * The COW Region between the start of the first allocated cluster and the
 395      * area the guest actually writes to.
 396      */
 397     Qcow2COWRegion cow_start;
 398
 399     /**
 400      * The COW Region between the area the guest actually writes to and the
 401      * end of the last allocated cluster.
 402      */
 403     Qcow2COWRegion cow_end;
 404
 405     /**
 406      * The I/O vector with the data from the actual guest write request.
 407      * If non-NULL, this is meant to be merged together with the data
 408      * from @cow_start and @cow_end into one single write operation.
 409      */
 410     QEMUIOVector *data_qiov;
 411
 412     /** Pointer to next L2Meta of the same write request */
 413     struct QCowL2Meta *next;
 414
 415     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 416 } QCowL2Meta;
 417
 418 typedef enum QCow2ClusterType {
 419     QCOW2_CLUSTER_UNALLOCATED,
 420     QCOW2_CLUSTER_ZERO_PLAIN,
 421     QCOW2_CLUSTER_ZERO_ALLOC,
 422     QCOW2_CLUSTER_NORMAL,
 423     QCOW2_CLUSTER_COMPRESSED,
 424 } QCow2ClusterType;
 425
 426 typedef enum QCow2MetadataOverlap {
 427     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 428     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 429     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 430     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 431     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 432     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 433     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 434     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 435     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 436
 437     QCOW2_OL_MAX_BITNR              = 9,
 438
 439     QCOW2_OL_NONE             = 0,
 440     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 441     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 442     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 443     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 444     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 445     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 446     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 447     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 448      * reads. */
 449     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 450     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 451 } QCow2MetadataOverlap;
 452
 453 /* Perform all overlap checks which can be done in constant time */
 454 #define QCOW2_OL_CONSTANT \
 455     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 456      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 457
 458 /* Perform all overlap checks which don't require disk access */
 459 #define QCOW2_OL_CACHED \
 460     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 461      QCOW2_OL_INACTIVE_L1)
 462
 463 /* Perform all overlap checks */
 464 #define QCOW2_OL_ALL \
 465     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 466
 467 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 468 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 469 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 470
 471 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 472
 473 #define INV_OFFSET (-1ULL)
 474
 475 static inline bool has_data_file(BlockDriverState *bs)
 476 {
 477     BDRVQcow2State *s = bs->opaque;
 478     return (s->data_file != bs->file);
 479 }
 480
 481 static inline bool data_file_is_raw(BlockDriverState *bs)
 482 {
 483     BDRVQcow2State *s = bs->opaque;
 484     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 485 }
 486
 487 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 488 {
 489     return offset & ~(s->cluster_size - 1);
 490 }
 491
 492 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 493 {
 494     return offset & (s->cluster_size - 1);
 495 }
 496
 497 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 498 {
 499     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 500 }
 501
 502 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 503 {
 504     int shift = s->cluster_bits + s->l2_bits;
 505     return (size + (1ULL << shift) - 1) >> shift;
 506 }
 507
 508 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 509 {
 510     return offset >> (s->l2_bits + s->cluster_bits);
 511 }
 512
 513 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 514 {
 515     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 516 }
 517
 518 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 519 {
 520     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 521 }
 522
 523 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 524 {
 525     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 526 }
 527
 528 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 529                                                       uint64_t l2_entry)
 530 {
 531     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 532         return QCOW2_CLUSTER_COMPRESSED;
 533     } else if (l2_entry & QCOW_OFLAG_ZERO) {
 534         if (l2_entry & L2E_OFFSET_MASK) {
 535             return QCOW2_CLUSTER_ZERO_ALLOC;
 536         }
 537         return QCOW2_CLUSTER_ZERO_PLAIN;
 538     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 539         /* Offset 0 generally means unallocated, but it is ambiguous with
 540          * external data files because 0 is a valid offset there. However, all
 541          * clusters in external data files always have refcount 1, so we can
 542          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 543         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 544             return QCOW2_CLUSTER_NORMAL;
 545         } else {
 546             return QCOW2_CLUSTER_UNALLOCATED;
 547         }
 548     } else {
 549         return QCOW2_CLUSTER_NORMAL;
 550     }
 551 }
 552
 553 /* Check whether refcounts are eager or lazy */
 554 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 555 {
 556     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 557 }
 558
 559 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 560 {
 561     return m->offset + m->cow_start.offset;
 562 }
 563
 564 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 565 {
 566     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 567 }
 568
 569 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 570 {
 571     return r1 > r2 ? r1 - r2 : r2 - r1;
 572 }
 573
 574 static inline
 575 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 576 {
 577     return offset >> (s->refcount_block_bits + s->cluster_bits);
 578 }
 579
 580 /* qcow2.c functions */
 581 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 582                                      int refcount_order, bool generous_increase,
 583                                      uint64_t *refblock_count);
 584
 585 int qcow2_mark_dirty(BlockDriverState *bs);
 586 int qcow2_mark_corrupt(BlockDriverState *bs);
 587 int qcow2_mark_consistent(BlockDriverState *bs);
 588 int qcow2_update_header(BlockDriverState *bs);
 589
 590 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 591                              int64_t size, const char *message_format, ...)
 592                              GCC_FMT_ATTR(5, 6);
 593
 594 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 595                          uint64_t entries, size_t entry_len,
 596                          int64_t max_size_bytes, const char *table_name,
 597                          Error **errp);
 598
 599 /* qcow2-refcount.c functions */
 600 int qcow2_refcount_init(BlockDriverState *bs);
 601 void qcow2_refcount_close(BlockDriverState *bs);
 602
 603 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 604                        uint64_t *refcount);
 605
 606 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 607                                   uint64_t addend, bool decrease,
 608                                   enum qcow2_discard_type type);
 609
 610 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 611                             uint64_t additional_clusters, bool exact_size,
 612                             int new_refblock_index,
 613                             uint64_t new_refblock_offset);
 614
 615 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 616 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 617                                 int64_t nb_clusters);
 618 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 619 void qcow2_free_clusters(BlockDriverState *bs,
 620                           int64_t offset, int64_t size,
 621                           enum qcow2_discard_type type);
 622 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 623                              int nb_clusters, enum qcow2_discard_type type);
 624
 625 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 626     int64_t l1_table_offset, int l1_size, int addend);
 627
 628 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 629 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 630 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 631                           BdrvCheckMode fix);
 632
 633 void qcow2_process_discards(BlockDriverState *bs, int ret);
 634
 635 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 636                                  int64_t size);
 637 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 638                                   int64_t size, bool data_file);
 639 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 640                              void **refcount_table,
 641                              int64_t *refcount_table_size,
 642                              int64_t offset, int64_t size);
 643
 644 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 645                                 BlockDriverAmendStatusCB *status_cb,
 646                                 void *cb_opaque, Error **errp);
 647 int qcow2_shrink_reftable(BlockDriverState *bs);
 648 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 649
 650 /* qcow2-cluster.c functions */
 651 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 652                         bool exact_size);
 653 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 654 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 655 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 656                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 657
 658 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 659                              unsigned int *bytes, uint64_t *cluster_offset);
 660 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 661                                unsigned int *bytes, uint64_t *host_offset,
 662                                QCowL2Meta **m);
 663 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 664                                           uint64_t offset,
 665                                           int compressed_size,
 666                                           uint64_t *host_offset);
 667
 668 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 669 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 670 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 671                           uint64_t bytes, enum qcow2_discard_type type,
 672                           bool full_discard);
 673 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
 674                           uint64_t bytes, int flags);
 675
 676 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 677                                BlockDriverAmendStatusCB *status_cb,
 678                                void *cb_opaque);
 679
 680 /* qcow2-snapshot.c functions */
 681 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 682 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 683 int qcow2_snapshot_delete(BlockDriverState *bs,
 684                           const char *snapshot_id,
 685                           const char *name,
 686                           Error **errp);
 687 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 688 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 689                             const char *snapshot_id,
 690                             const char *name,
 691                             Error **errp);
 692
 693 void qcow2_free_snapshots(BlockDriverState *bs);
 694 int qcow2_read_snapshots(BlockDriverState *bs);
 695
 696 /* qcow2-cache.c functions */
 697 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 698                                unsigned table_size);
 699 int qcow2_cache_destroy(Qcow2Cache *c);
 700
 701 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 702 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 703 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 704 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 705     Qcow2Cache *dependency);
 706 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 707
 708 void qcow2_cache_clean_unused(Qcow2Cache *c);
 709 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 710
 711 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 712     void **table);
 713 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 714     void **table);
 715 void qcow2_cache_put(Qcow2Cache *c, void **table);
 716 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 717 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 718
 719 /* qcow2-bitmap.c functions */
 720 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 721                                   void **refcount_table,
 722                                   int64_t *refcount_table_size);
 723 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 724 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
 725                                                 Error **errp);
 726 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
 727                                  Error **errp);
 728 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 729 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
 730 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 731 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 732 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
 733                                       const char *name,
 734                                       uint32_t granularity,
 735                                       Error **errp);
 736 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 737                                           const char *name,
 738                                           Error **errp);
 739
 740 #endif