block/dirty-bitmap.c

   1 /*
   2  * Block Dirty Bitmap
   3  *
   4  * Copyright (c) 2016 Red Hat. Inc
   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 #include "qemu/osdep.h"
  25 #include "qapi/error.h"
  26 #include "qemu-common.h"
  27 #include "trace.h"
  28 #include "block/block_int.h"
  29 #include "block/blockjob.h"
  30
  31 /**
  32  * A BdrvDirtyBitmap can be in three possible states:
  33  * (1) successor is NULL and disabled is false: full r/w mode
  34  * (2) successor is NULL and disabled is true: read only mode ("disabled")
  35  * (3) successor is set: frozen mode.
  36  *     A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
  37  *     or enabled. A frozen bitmap can only abdicate() or reclaim().
  38  */
  39 struct BdrvDirtyBitmap {
  40     QemuMutex *mutex;
  41     HBitmap *bitmap;            /* Dirty sector bitmap implementation */
  42     HBitmap *meta;              /* Meta dirty bitmap */
  43     BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
  44     char *name;                 /* Optional non-empty unique ID */
  45     int64_t size;               /* Size of the bitmap (Number of sectors) */
  46     bool disabled;              /* Bitmap is disabled. It ignores all writes to
  47                                    the device */
  48     int active_iterators;       /* How many iterators are active */
  49     bool readonly;              /* Bitmap is read-only. This field also
  50                                    prevents the respective image from being
  51                                    modified (i.e. blocks writes and discards).
  52                                    Such operations must fail and both the image
  53                                    and this bitmap must remain unchanged while
  54                                    this flag is set. */
  55     bool autoload;              /* For persistent bitmaps: bitmap must be
  56                                    autoloaded on image opening */
  57     bool persistent;            /* bitmap must be saved to owner disk image */
  58     QLIST_ENTRY(BdrvDirtyBitmap) list;
  59 };
  60
  61 struct BdrvDirtyBitmapIter {
  62     HBitmapIter hbi;
  63     BdrvDirtyBitmap *bitmap;
  64 };
  65
  66 static inline void bdrv_dirty_bitmaps_lock(BlockDriverState *bs)
  67 {
  68     qemu_mutex_lock(&bs->dirty_bitmap_mutex);
  69 }
  70
  71 static inline void bdrv_dirty_bitmaps_unlock(BlockDriverState *bs)
  72 {
  73     qemu_mutex_unlock(&bs->dirty_bitmap_mutex);
  74 }
  75
  76 void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap)
  77 {
  78     qemu_mutex_lock(bitmap->mutex);
  79 }
  80
  81 void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap)
  82 {
  83     qemu_mutex_unlock(bitmap->mutex);
  84 }
  85
  86 /* Called with BQL or dirty_bitmap lock taken.  */
  87 BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
  88 {
  89     BdrvDirtyBitmap *bm;
  90
  91     assert(name);
  92     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
  93         if (bm->name && !strcmp(name, bm->name)) {
  94             return bm;
  95         }
  96     }
  97     return NULL;
  98 }
  99
 100 /* Called with BQL taken.  */
 101 void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
 102 {
 103     assert(!bdrv_dirty_bitmap_frozen(bitmap));
 104     g_free(bitmap->name);
 105     bitmap->name = NULL;
 106     bitmap->persistent = false;
 107     bitmap->autoload = false;
 108 }
 109
 110 /* Called with BQL taken.  */
 111 BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
 112                                           uint32_t granularity,
 113                                           const char *name,
 114                                           Error **errp)
 115 {
 116     int64_t bitmap_size;
 117     BdrvDirtyBitmap *bitmap;
 118     uint32_t sector_granularity;
 119
 120     assert((granularity & (granularity - 1)) == 0);
 121
 122     if (name && bdrv_find_dirty_bitmap(bs, name)) {
 123         error_setg(errp, "Bitmap already exists: %s", name);
 124         return NULL;
 125     }
 126     sector_granularity = granularity >> BDRV_SECTOR_BITS;
 127     assert(sector_granularity);
 128     bitmap_size = bdrv_nb_sectors(bs);
 129     if (bitmap_size < 0) {
 130         error_setg_errno(errp, -bitmap_size, "could not get length of device");
 131         errno = -bitmap_size;
 132         return NULL;
 133     }
 134     bitmap = g_new0(BdrvDirtyBitmap, 1);
 135     bitmap->mutex = &bs->dirty_bitmap_mutex;
 136     bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
 137     bitmap->size = bitmap_size;
 138     bitmap->name = g_strdup(name);
 139     bitmap->disabled = false;
 140     bdrv_dirty_bitmaps_lock(bs);
 141     QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
 142     bdrv_dirty_bitmaps_unlock(bs);
 143     return bitmap;
 144 }
 145
 146 /* bdrv_create_meta_dirty_bitmap
 147  *
 148  * Create a meta dirty bitmap that tracks the changes of bits in @bitmap. I.e.
 149  * when a dirty status bit in @bitmap is changed (either from reset to set or
 150  * the other way around), its respective meta dirty bitmap bit will be marked
 151  * dirty as well.
 152  *
 153  * @bitmap: the block dirty bitmap for which to create a meta dirty bitmap.
 154  * @chunk_size: how many bytes of bitmap data does each bit in the meta bitmap
 155  * track.
 156  */
 157 void bdrv_create_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 158                                    int chunk_size)
 159 {
 160     assert(!bitmap->meta);
 161     qemu_mutex_lock(bitmap->mutex);
 162     bitmap->meta = hbitmap_create_meta(bitmap->bitmap,
 163                                        chunk_size * BITS_PER_BYTE);
 164     qemu_mutex_unlock(bitmap->mutex);
 165 }
 166
 167 void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 168 {
 169     assert(bitmap->meta);
 170     qemu_mutex_lock(bitmap->mutex);
 171     hbitmap_free_meta(bitmap->bitmap);
 172     bitmap->meta = NULL;
 173     qemu_mutex_unlock(bitmap->mutex);
 174 }
 175
 176 int bdrv_dirty_bitmap_get_meta_locked(BlockDriverState *bs,
 177                                       BdrvDirtyBitmap *bitmap, int64_t sector,
 178                                       int nb_sectors)
 179 {
 180     uint64_t i;
 181     int sectors_per_bit = 1 << hbitmap_granularity(bitmap->meta);
 182
 183     /* To optimize: we can make hbitmap to internally check the range in a
 184      * coarse level, or at least do it word by word. */
 185     for (i = sector; i < sector + nb_sectors; i += sectors_per_bit) {
 186         if (hbitmap_get(bitmap->meta, i)) {
 187             return true;
 188         }
 189     }
 190     return false;
 191 }
 192
 193 int bdrv_dirty_bitmap_get_meta(BlockDriverState *bs,
 194                                BdrvDirtyBitmap *bitmap, int64_t sector,
 195                                int nb_sectors)
 196 {
 197     bool dirty;
 198
 199     qemu_mutex_lock(bitmap->mutex);
 200     dirty = bdrv_dirty_bitmap_get_meta_locked(bs, bitmap, sector, nb_sectors);
 201     qemu_mutex_unlock(bitmap->mutex);
 202
 203     return dirty;
 204 }
 205
 206 void bdrv_dirty_bitmap_reset_meta(BlockDriverState *bs,
 207                                   BdrvDirtyBitmap *bitmap, int64_t sector,
 208                                   int nb_sectors)
 209 {
 210     qemu_mutex_lock(bitmap->mutex);
 211     hbitmap_reset(bitmap->meta, sector, nb_sectors);
 212     qemu_mutex_unlock(bitmap->mutex);
 213 }
 214
 215 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
 216 {
 217     return bitmap->size;
 218 }
 219
 220 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
 221 {
 222     return bitmap->name;
 223 }
 224
 225 /* Called with BQL taken.  */
 226 bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
 227 {
 228     return bitmap->successor;
 229 }
 230
 231 /* Called with BQL taken.  */
 232 bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
 233 {
 234     return !(bitmap->disabled || bitmap->successor);
 235 }
 236
 237 /* Called with BQL taken.  */
 238 DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
 239 {
 240     if (bdrv_dirty_bitmap_frozen(bitmap)) {
 241         return DIRTY_BITMAP_STATUS_FROZEN;
 242     } else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
 243         return DIRTY_BITMAP_STATUS_DISABLED;
 244     } else {
 245         return DIRTY_BITMAP_STATUS_ACTIVE;
 246     }
 247 }
 248
 249 /**
 250  * Create a successor bitmap destined to replace this bitmap after an operation.
 251  * Requires that the bitmap is not frozen and has no successor.
 252  * Called with BQL taken.
 253  */
 254 int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
 255                                        BdrvDirtyBitmap *bitmap, Error **errp)
 256 {
 257     uint64_t granularity;
 258     BdrvDirtyBitmap *child;
 259
 260     if (bdrv_dirty_bitmap_frozen(bitmap)) {
 261         error_setg(errp, "Cannot create a successor for a bitmap that is "
 262                    "currently frozen");
 263         return -1;
 264     }
 265     assert(!bitmap->successor);
 266
 267     /* Create an anonymous successor */
 268     granularity = bdrv_dirty_bitmap_granularity(bitmap);
 269     child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
 270     if (!child) {
 271         return -1;
 272     }
 273
 274     /* Successor will be on or off based on our current state. */
 275     child->disabled = bitmap->disabled;
 276
 277     /* Install the successor and freeze the parent */
 278     bitmap->successor = child;
 279     return 0;
 280 }
 281
 282 /**
 283  * For a bitmap with a successor, yield our name to the successor,
 284  * delete the old bitmap, and return a handle to the new bitmap.
 285  * Called with BQL taken.
 286  */
 287 BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
 288                                             BdrvDirtyBitmap *bitmap,
 289                                             Error **errp)
 290 {
 291     char *name;
 292     BdrvDirtyBitmap *successor = bitmap->successor;
 293
 294     if (successor == NULL) {
 295         error_setg(errp, "Cannot relinquish control if "
 296                    "there's no successor present");
 297         return NULL;
 298     }
 299
 300     name = bitmap->name;
 301     bitmap->name = NULL;
 302     successor->name = name;
 303     bitmap->successor = NULL;
 304     successor->persistent = bitmap->persistent;
 305     bitmap->persistent = false;
 306     successor->autoload = bitmap->autoload;
 307     bitmap->autoload = false;
 308     bdrv_release_dirty_bitmap(bs, bitmap);
 309
 310     return successor;
 311 }
 312
 313 /**
 314  * In cases of failure where we can no longer safely delete the parent,
 315  * we may wish to re-join the parent and child/successor.
 316  * The merged parent will be un-frozen, but not explicitly re-enabled.
 317  * Called with BQL taken.
 318  */
 319 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
 320                                            BdrvDirtyBitmap *parent,
 321                                            Error **errp)
 322 {
 323     BdrvDirtyBitmap *successor = parent->successor;
 324
 325     if (!successor) {
 326         error_setg(errp, "Cannot reclaim a successor when none is present");
 327         return NULL;
 328     }
 329
 330     if (!hbitmap_merge(parent->bitmap, successor->bitmap)) {
 331         error_setg(errp, "Merging of parent and successor bitmap failed");
 332         return NULL;
 333     }
 334     bdrv_release_dirty_bitmap(bs, successor);
 335     parent->successor = NULL;
 336
 337     return parent;
 338 }
 339
 340 /**
 341  * Truncates _all_ bitmaps attached to a BDS.
 342  * Called with BQL taken.
 343  */
 344 void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
 345 {
 346     BdrvDirtyBitmap *bitmap;
 347     uint64_t size = bdrv_nb_sectors(bs);
 348
 349     bdrv_dirty_bitmaps_lock(bs);
 350     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
 351         assert(!bdrv_dirty_bitmap_frozen(bitmap));
 352         assert(!bitmap->active_iterators);
 353         hbitmap_truncate(bitmap->bitmap, size);
 354         bitmap->size = size;
 355     }
 356     bdrv_dirty_bitmaps_unlock(bs);
 357 }
 358
 359 static bool bdrv_dirty_bitmap_has_name(BdrvDirtyBitmap *bitmap)
 360 {
 361     return !!bdrv_dirty_bitmap_name(bitmap);
 362 }
 363
 364 /* Called with BQL taken.  */
 365 static void bdrv_do_release_matching_dirty_bitmap(
 366     BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
 367     bool (*cond)(BdrvDirtyBitmap *bitmap))
 368 {
 369     BdrvDirtyBitmap *bm, *next;
 370     bdrv_dirty_bitmaps_lock(bs);
 371     QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
 372         if ((!bitmap || bm == bitmap) && (!cond || cond(bm))) {
 373             assert(!bm->active_iterators);
 374             assert(!bdrv_dirty_bitmap_frozen(bm));
 375             assert(!bm->meta);
 376             QLIST_REMOVE(bm, list);
 377             hbitmap_free(bm->bitmap);
 378             g_free(bm->name);
 379             g_free(bm);
 380
 381             if (bitmap) {
 382                 goto out;
 383             }
 384         }
 385     }
 386     if (bitmap) {
 387         abort();
 388     }
 389
 390 out:
 391     bdrv_dirty_bitmaps_unlock(bs);
 392 }
 393
 394 /* Called with BQL taken.  */
 395 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
 396 {
 397     bdrv_do_release_matching_dirty_bitmap(bs, bitmap, NULL);
 398 }
 399
 400 /**
 401  * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
 402  * There must not be any frozen bitmaps attached.
 403  * This function does not remove persistent bitmaps from the storage.
 404  * Called with BQL taken.
 405  */
 406 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
 407 {
 408     bdrv_do_release_matching_dirty_bitmap(bs, NULL, bdrv_dirty_bitmap_has_name);
 409 }
 410
 411 /**
 412  * Release all persistent dirty bitmaps attached to a BDS (for use in
 413  * bdrv_inactivate_recurse()).
 414  * There must not be any frozen bitmaps attached.
 415  * This function does not remove persistent bitmaps from the storage.
 416  */
 417 void bdrv_release_persistent_dirty_bitmaps(BlockDriverState *bs)
 418 {
 419     bdrv_do_release_matching_dirty_bitmap(bs, NULL,
 420                                           bdrv_dirty_bitmap_get_persistance);
 421 }
 422
 423 /**
 424  * Remove persistent dirty bitmap from the storage if it exists.
 425  * Absence of bitmap is not an error, because we have the following scenario:
 426  * BdrvDirtyBitmap can have .persistent = true but not yet saved and have no
 427  * stored version. For such bitmap bdrv_remove_persistent_dirty_bitmap() should
 428  * not fail.
 429  * This function doesn't release corresponding BdrvDirtyBitmap.
 430  */
 431 void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 432                                          const char *name,
 433                                          Error **errp)
 434 {
 435     if (bs->drv && bs->drv->bdrv_remove_persistent_dirty_bitmap) {
 436         bs->drv->bdrv_remove_persistent_dirty_bitmap(bs, name, errp);
 437     }
 438 }
 439
 440 /* Called with BQL taken.  */
 441 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 442 {
 443     assert(!bdrv_dirty_bitmap_frozen(bitmap));
 444     bitmap->disabled = true;
 445 }
 446
 447 /* Called with BQL taken.  */
 448 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 449 {
 450     assert(!bdrv_dirty_bitmap_frozen(bitmap));
 451     bitmap->disabled = false;
 452 }
 453
 454 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
 455 {
 456     BdrvDirtyBitmap *bm;
 457     BlockDirtyInfoList *list = NULL;
 458     BlockDirtyInfoList **plist = &list;
 459
 460     bdrv_dirty_bitmaps_lock(bs);
 461     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 462         BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
 463         BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
 464         info->count = bdrv_get_dirty_count(bm);
 465         info->granularity = bdrv_dirty_bitmap_granularity(bm);
 466         info->has_name = !!bm->name;
 467         info->name = g_strdup(bm->name);
 468         info->status = bdrv_dirty_bitmap_status(bm);
 469         entry->value = info;
 470         *plist = entry;
 471         plist = &entry->next;
 472     }
 473     bdrv_dirty_bitmaps_unlock(bs);
 474
 475     return list;
 476 }
 477
 478 /* Called within bdrv_dirty_bitmap_lock..unlock */
 479 int bdrv_get_dirty_locked(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
 480                           int64_t sector)
 481 {
 482     if (bitmap) {
 483         return hbitmap_get(bitmap->bitmap, sector);
 484     } else {
 485         return 0;
 486     }
 487 }
 488
 489 /**
 490  * Chooses a default granularity based on the existing cluster size,
 491  * but clamped between [4K, 64K]. Defaults to 64K in the case that there
 492  * is no cluster size information available.
 493  */
 494 uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
 495 {
 496     BlockDriverInfo bdi;
 497     uint32_t granularity;
 498
 499     if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) {
 500         granularity = MAX(4096, bdi.cluster_size);
 501         granularity = MIN(65536, granularity);
 502     } else {
 503         granularity = 65536;
 504     }
 505
 506     return granularity;
 507 }
 508
 509 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
 510 {
 511     return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
 512 }
 513
 514 uint32_t bdrv_dirty_bitmap_meta_granularity(BdrvDirtyBitmap *bitmap)
 515 {
 516     return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->meta);
 517 }
 518
 519 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap,
 520                                          uint64_t first_sector)
 521 {
 522     BdrvDirtyBitmapIter *iter = g_new(BdrvDirtyBitmapIter, 1);
 523     hbitmap_iter_init(&iter->hbi, bitmap->bitmap, first_sector);
 524     iter->bitmap = bitmap;
 525     bitmap->active_iterators++;
 526     return iter;
 527 }
 528
 529 BdrvDirtyBitmapIter *bdrv_dirty_meta_iter_new(BdrvDirtyBitmap *bitmap)
 530 {
 531     BdrvDirtyBitmapIter *iter = g_new(BdrvDirtyBitmapIter, 1);
 532     hbitmap_iter_init(&iter->hbi, bitmap->meta, 0);
 533     iter->bitmap = bitmap;
 534     bitmap->active_iterators++;
 535     return iter;
 536 }
 537
 538 void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 539 {
 540     if (!iter) {
 541         return;
 542     }
 543     assert(iter->bitmap->active_iterators > 0);
 544     iter->bitmap->active_iterators--;
 545     g_free(iter);
 546 }
 547
 548 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 549 {
 550     return hbitmap_iter_next(&iter->hbi);
 551 }
 552
 553 /* Called within bdrv_dirty_bitmap_lock..unlock */
 554 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 555                                   int64_t cur_sector, int64_t nr_sectors)
 556 {
 557     assert(bdrv_dirty_bitmap_enabled(bitmap));
 558     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 559     hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
 560 }
 561
 562 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 563                            int64_t cur_sector, int64_t nr_sectors)
 564 {
 565     bdrv_dirty_bitmap_lock(bitmap);
 566     bdrv_set_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
 567     bdrv_dirty_bitmap_unlock(bitmap);
 568 }
 569
 570 /* Called within bdrv_dirty_bitmap_lock..unlock */
 571 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 572                                     int64_t cur_sector, int64_t nr_sectors)
 573 {
 574     assert(bdrv_dirty_bitmap_enabled(bitmap));
 575     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 576     hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
 577 }
 578
 579 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 580                              int64_t cur_sector, int64_t nr_sectors)
 581 {
 582     bdrv_dirty_bitmap_lock(bitmap);
 583     bdrv_reset_dirty_bitmap_locked(bitmap, cur_sector, nr_sectors);
 584     bdrv_dirty_bitmap_unlock(bitmap);
 585 }
 586
 587 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
 588 {
 589     assert(bdrv_dirty_bitmap_enabled(bitmap));
 590     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 591     bdrv_dirty_bitmap_lock(bitmap);
 592     if (!out) {
 593         hbitmap_reset_all(bitmap->bitmap);
 594     } else {
 595         HBitmap *backup = bitmap->bitmap;
 596         bitmap->bitmap = hbitmap_alloc(bitmap->size,
 597                                        hbitmap_granularity(backup));
 598         *out = backup;
 599     }
 600     bdrv_dirty_bitmap_unlock(bitmap);
 601 }
 602
 603 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
 604 {
 605     HBitmap *tmp = bitmap->bitmap;
 606     assert(bdrv_dirty_bitmap_enabled(bitmap));
 607     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 608     bitmap->bitmap = in;
 609     hbitmap_free(tmp);
 610 }
 611
 612 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
 613                                               uint64_t start, uint64_t count)
 614 {
 615     return hbitmap_serialization_size(bitmap->bitmap, start, count);
 616 }
 617
 618 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 619 {
 620     return hbitmap_serialization_granularity(bitmap->bitmap);
 621 }
 622
 623 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
 624                                       uint8_t *buf, uint64_t start,
 625                                       uint64_t count)
 626 {
 627     hbitmap_serialize_part(bitmap->bitmap, buf, start, count);
 628 }
 629
 630 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
 631                                         uint8_t *buf, uint64_t start,
 632                                         uint64_t count, bool finish)
 633 {
 634     hbitmap_deserialize_part(bitmap->bitmap, buf, start, count, finish);
 635 }
 636
 637 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
 638                                           uint64_t start, uint64_t count,
 639                                           bool finish)
 640 {
 641     hbitmap_deserialize_zeroes(bitmap->bitmap, start, count, finish);
 642 }
 643
 644 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
 645                                         uint64_t start, uint64_t count,
 646                                         bool finish)
 647 {
 648     hbitmap_deserialize_ones(bitmap->bitmap, start, count, finish);
 649 }
 650
 651 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
 652 {
 653     hbitmap_deserialize_finish(bitmap->bitmap);
 654 }
 655
 656 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
 657                     int64_t nr_sectors)
 658 {
 659     BdrvDirtyBitmap *bitmap;
 660
 661     if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
 662         return;
 663     }
 664
 665     bdrv_dirty_bitmaps_lock(bs);
 666     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
 667         if (!bdrv_dirty_bitmap_enabled(bitmap)) {
 668             continue;
 669         }
 670         assert(!bdrv_dirty_bitmap_readonly(bitmap));
 671         hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
 672     }
 673     bdrv_dirty_bitmaps_unlock(bs);
 674 }
 675
 676 /**
 677  * Advance a BdrvDirtyBitmapIter to an arbitrary offset.
 678  */
 679 void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t sector_num)
 680 {
 681     hbitmap_iter_init(&iter->hbi, iter->hbi.hb, sector_num);
 682 }
 683
 684 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
 685 {
 686     return hbitmap_count(bitmap->bitmap);
 687 }
 688
 689 int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
 690 {
 691     return hbitmap_count(bitmap->meta);
 692 }
 693
 694 bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap)
 695 {
 696     return bitmap->readonly;
 697 }
 698
 699 /* Called with BQL taken. */
 700 void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value)
 701 {
 702     qemu_mutex_lock(bitmap->mutex);
 703     bitmap->readonly = value;
 704     qemu_mutex_unlock(bitmap->mutex);
 705 }
 706
 707 bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
 708 {
 709     BdrvDirtyBitmap *bm;
 710     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 711         if (bm->readonly) {
 712             return true;
 713         }
 714     }
 715
 716     return false;
 717 }
 718
 719 /* Called with BQL taken. */
 720 void bdrv_dirty_bitmap_set_autoload(BdrvDirtyBitmap *bitmap, bool autoload)
 721 {
 722     qemu_mutex_lock(bitmap->mutex);
 723     bitmap->autoload = autoload;
 724     qemu_mutex_unlock(bitmap->mutex);
 725 }
 726
 727 bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap)
 728 {
 729     return bitmap->autoload;
 730 }
 731
 732 /* Called with BQL taken. */
 733 void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap, bool persistent)
 734 {
 735     qemu_mutex_lock(bitmap->mutex);
 736     bitmap->persistent = persistent;
 737     qemu_mutex_unlock(bitmap->mutex);
 738 }
 739
 740 bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap)
 741 {
 742     return bitmap->persistent;
 743 }
 744
 745 bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs)
 746 {
 747     BdrvDirtyBitmap *bm;
 748     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 749         if (bm->persistent && !bm->readonly) {
 750             return true;
 751         }
 752     }
 753
 754     return false;
 755 }
 756
 757 BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
 758                                         BdrvDirtyBitmap *bitmap)
 759 {
 760     return bitmap == NULL ? QLIST_FIRST(&bs->dirty_bitmaps) :
 761                             QLIST_NEXT(bitmap, list);
 762 }
 763
 764 char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp)
 765 {
 766     return hbitmap_sha256(bitmap->bitmap, errp);
 767 }