block/dirty-bitmap.c

   1 /*
   2  * Block Dirty Bitmap
   3  *
   4  * Copyright (c) 2016-2017 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 "trace.h"
  27 #include "block/block_int.h"
  28 #include "block/blockjob.h"
  29 #include "qemu/main-loop.h"
  30
  31 struct BdrvDirtyBitmap {
  32     BlockDriverState *bs;
  33     HBitmap *bitmap;            /* Dirty bitmap implementation */
  34     bool busy;                  /* Bitmap is busy, it can't be used via QMP */
  35     BdrvDirtyBitmap *successor; /* Anonymous child, if any. */
  36     char *name;                 /* Optional non-empty unique ID */
  37     int64_t size;               /* Size of the bitmap, in bytes */
  38     bool disabled;              /* Bitmap is disabled. It ignores all writes to
  39                                    the device */
  40     int active_iterators;       /* How many iterators are active */
  41     bool readonly;              /* Bitmap is read-only. This field also
  42                                    prevents the respective image from being
  43                                    modified (i.e. blocks writes and discards).
  44                                    Such operations must fail and both the image
  45                                    and this bitmap must remain unchanged while
  46                                    this flag is set. */
  47     bool persistent;            /* bitmap must be saved to owner disk image */
  48     bool inconsistent;          /* bitmap is persistent, but inconsistent.
  49                                    It cannot be used at all in any way, except
  50                                    a QMP user can remove it. */
  51     bool skip_store;            /* We are either migrating or deleting this
  52                                  * bitmap; it should not be stored on the next
  53                                  * inactivation. */
  54     QLIST_ENTRY(BdrvDirtyBitmap) list;
  55 };
  56
  57 struct BdrvDirtyBitmapIter {
  58     HBitmapIter hbi;
  59     BdrvDirtyBitmap *bitmap;
  60 };
  61
  62 static inline void bdrv_dirty_bitmaps_lock(BlockDriverState *bs)
  63 {
  64     qemu_mutex_lock(&bs->dirty_bitmap_mutex);
  65 }
  66
  67 static inline void bdrv_dirty_bitmaps_unlock(BlockDriverState *bs)
  68 {
  69     qemu_mutex_unlock(&bs->dirty_bitmap_mutex);
  70 }
  71
  72 void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap)
  73 {
  74     bdrv_dirty_bitmaps_lock(bitmap->bs);
  75 }
  76
  77 void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap)
  78 {
  79     bdrv_dirty_bitmaps_unlock(bitmap->bs);
  80 }
  81
  82 /* Called with BQL or dirty_bitmap lock taken.  */
  83 BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
  84 {
  85     BdrvDirtyBitmap *bm;
  86
  87     assert(name);
  88     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
  89         if (bm->name && !strcmp(name, bm->name)) {
  90             return bm;
  91         }
  92     }
  93     return NULL;
  94 }
  95
  96 /* Called with BQL taken.  */
  97 BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
  98                                           uint32_t granularity,
  99                                           const char *name,
 100                                           Error **errp)
 101 {
 102     int64_t bitmap_size;
 103     BdrvDirtyBitmap *bitmap;
 104
 105     assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE);
 106
 107     if (name) {
 108         if (bdrv_find_dirty_bitmap(bs, name)) {
 109             error_setg(errp, "Bitmap already exists: %s", name);
 110             return NULL;
 111         }
 112         if (strlen(name) > BDRV_BITMAP_MAX_NAME_SIZE) {
 113             error_setg(errp, "Bitmap name too long: %s", name);
 114             return NULL;
 115         }
 116     }
 117     bitmap_size = bdrv_getlength(bs);
 118     if (bitmap_size < 0) {
 119         error_setg_errno(errp, -bitmap_size, "could not get length of device");
 120         errno = -bitmap_size;
 121         return NULL;
 122     }
 123     bitmap = g_new0(BdrvDirtyBitmap, 1);
 124     bitmap->bs = bs;
 125     bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity));
 126     bitmap->size = bitmap_size;
 127     bitmap->name = g_strdup(name);
 128     bitmap->disabled = false;
 129     bdrv_dirty_bitmaps_lock(bs);
 130     QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
 131     bdrv_dirty_bitmaps_unlock(bs);
 132     return bitmap;
 133 }
 134
 135 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)
 136 {
 137     return bitmap->size;
 138 }
 139
 140 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)
 141 {
 142     return bitmap->name;
 143 }
 144
 145 /* Called with BQL taken.  */
 146 bool bdrv_dirty_bitmap_has_successor(BdrvDirtyBitmap *bitmap)
 147 {
 148     return bitmap->successor;
 149 }
 150
 151 static bool bdrv_dirty_bitmap_busy(const BdrvDirtyBitmap *bitmap)
 152 {
 153     return bitmap->busy;
 154 }
 155
 156 void bdrv_dirty_bitmap_set_busy(BdrvDirtyBitmap *bitmap, bool busy)
 157 {
 158     bdrv_dirty_bitmaps_lock(bitmap->bs);
 159     bitmap->busy = busy;
 160     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 161 }
 162
 163 /* Called with BQL taken.  */
 164 bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
 165 {
 166     return !bitmap->disabled;
 167 }
 168
 169 /* Called with BQL taken.  */
 170 static bool bdrv_dirty_bitmap_recording(BdrvDirtyBitmap *bitmap)
 171 {
 172     return !bitmap->disabled || (bitmap->successor &&
 173                                  !bitmap->successor->disabled);
 174 }
 175
 176 int bdrv_dirty_bitmap_check(const BdrvDirtyBitmap *bitmap, uint32_t flags,
 177                             Error **errp)
 178 {
 179     if ((flags & BDRV_BITMAP_BUSY) && bdrv_dirty_bitmap_busy(bitmap)) {
 180         error_setg(errp, "Bitmap '%s' is currently in use by another"
 181                    " operation and cannot be used", bitmap->name);
 182         return -1;
 183     }
 184
 185     if ((flags & BDRV_BITMAP_RO) && bdrv_dirty_bitmap_readonly(bitmap)) {
 186         error_setg(errp, "Bitmap '%s' is readonly and cannot be modified",
 187                    bitmap->name);
 188         return -1;
 189     }
 190
 191     if ((flags & BDRV_BITMAP_INCONSISTENT) &&
 192         bdrv_dirty_bitmap_inconsistent(bitmap)) {
 193         error_setg(errp, "Bitmap '%s' is inconsistent and cannot be used",
 194                    bitmap->name);
 195         error_append_hint(errp, "Try block-dirty-bitmap-remove to delete"
 196                           " this bitmap from disk\n");
 197         return -1;
 198     }
 199
 200     return 0;
 201 }
 202
 203 /**
 204  * Create a successor bitmap destined to replace this bitmap after an operation.
 205  * Requires that the bitmap is not marked busy and has no successor.
 206  * The successor will be enabled if the parent bitmap was.
 207  * Called with BQL taken.
 208  */
 209 int bdrv_dirty_bitmap_create_successor(BdrvDirtyBitmap *bitmap, Error **errp)
 210 {
 211     uint64_t granularity;
 212     BdrvDirtyBitmap *child;
 213
 214     if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_BUSY, errp)) {
 215         return -1;
 216     }
 217     if (bdrv_dirty_bitmap_has_successor(bitmap)) {
 218         error_setg(errp, "Cannot create a successor for a bitmap that already "
 219                    "has one");
 220         return -1;
 221     }
 222
 223     /* Create an anonymous successor */
 224     granularity = bdrv_dirty_bitmap_granularity(bitmap);
 225     child = bdrv_create_dirty_bitmap(bitmap->bs, granularity, NULL, errp);
 226     if (!child) {
 227         return -1;
 228     }
 229
 230     /* Successor will be on or off based on our current state. */
 231     child->disabled = bitmap->disabled;
 232     bitmap->disabled = true;
 233
 234     /* Install the successor and mark the parent as busy */
 235     bitmap->successor = child;
 236     bitmap->busy = true;
 237     return 0;
 238 }
 239
 240 void bdrv_enable_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap)
 241 {
 242     bitmap->disabled = false;
 243 }
 244
 245 /* Called with BQL taken. */
 246 void bdrv_dirty_bitmap_enable_successor(BdrvDirtyBitmap *bitmap)
 247 {
 248     assert(bitmap->bs == bitmap->successor->bs);
 249     bdrv_dirty_bitmaps_lock(bitmap->bs);
 250     bdrv_enable_dirty_bitmap_locked(bitmap->successor);
 251     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 252 }
 253
 254 /* Called within bdrv_dirty_bitmap_lock..unlock and with BQL taken.  */
 255 static void bdrv_release_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap)
 256 {
 257     assert(!bitmap->active_iterators);
 258     assert(!bdrv_dirty_bitmap_busy(bitmap));
 259     assert(!bdrv_dirty_bitmap_has_successor(bitmap));
 260     QLIST_REMOVE(bitmap, list);
 261     hbitmap_free(bitmap->bitmap);
 262     g_free(bitmap->name);
 263     g_free(bitmap);
 264 }
 265
 266 /**
 267  * For a bitmap with a successor, yield our name to the successor,
 268  * delete the old bitmap, and return a handle to the new bitmap.
 269  * Called with BQL taken.
 270  */
 271 BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BdrvDirtyBitmap *bitmap,
 272                                             Error **errp)
 273 {
 274     char *name;
 275     BdrvDirtyBitmap *successor = bitmap->successor;
 276
 277     if (successor == NULL) {
 278         error_setg(errp, "Cannot relinquish control if "
 279                    "there's no successor present");
 280         return NULL;
 281     }
 282
 283     name = bitmap->name;
 284     bitmap->name = NULL;
 285     successor->name = name;
 286     bitmap->successor = NULL;
 287     successor->persistent = bitmap->persistent;
 288     bitmap->persistent = false;
 289     bitmap->busy = false;
 290     bdrv_release_dirty_bitmap(bitmap);
 291
 292     return successor;
 293 }
 294
 295 /**
 296  * In cases of failure where we can no longer safely delete the parent,
 297  * we may wish to re-join the parent and child/successor.
 298  * The merged parent will be marked as not busy.
 299  * The marged parent will be enabled if and only if the successor was enabled.
 300  * Called within bdrv_dirty_bitmap_lock..unlock and with BQL taken.
 301  */
 302 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap_locked(BdrvDirtyBitmap *parent,
 303                                                   Error **errp)
 304 {
 305     BdrvDirtyBitmap *successor = parent->successor;
 306
 307     if (!successor) {
 308         error_setg(errp, "Cannot reclaim a successor when none is present");
 309         return NULL;
 310     }
 311
 312     if (!hbitmap_merge(parent->bitmap, successor->bitmap, parent->bitmap)) {
 313         error_setg(errp, "Merging of parent and successor bitmap failed");
 314         return NULL;
 315     }
 316
 317     parent->disabled = successor->disabled;
 318     parent->busy = false;
 319     bdrv_release_dirty_bitmap_locked(successor);
 320     parent->successor = NULL;
 321
 322     return parent;
 323 }
 324
 325 /* Called with BQL taken. */
 326 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BdrvDirtyBitmap *parent,
 327                                            Error **errp)
 328 {
 329     BdrvDirtyBitmap *ret;
 330
 331     bdrv_dirty_bitmaps_lock(parent->bs);
 332     ret = bdrv_reclaim_dirty_bitmap_locked(parent, errp);
 333     bdrv_dirty_bitmaps_unlock(parent->bs);
 334
 335     return ret;
 336 }
 337
 338 /**
 339  * Truncates _all_ bitmaps attached to a BDS.
 340  * Called with BQL taken.
 341  */
 342 void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes)
 343 {
 344     BdrvDirtyBitmap *bitmap;
 345
 346     bdrv_dirty_bitmaps_lock(bs);
 347     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
 348         assert(!bdrv_dirty_bitmap_busy(bitmap));
 349         assert(!bdrv_dirty_bitmap_has_successor(bitmap));
 350         assert(!bitmap->active_iterators);
 351         hbitmap_truncate(bitmap->bitmap, bytes);
 352         bitmap->size = bytes;
 353     }
 354     bdrv_dirty_bitmaps_unlock(bs);
 355 }
 356
 357 /* Called with BQL taken.  */
 358 void bdrv_release_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 359 {
 360     BlockDriverState *bs = bitmap->bs;
 361
 362     bdrv_dirty_bitmaps_lock(bs);
 363     bdrv_release_dirty_bitmap_locked(bitmap);
 364     bdrv_dirty_bitmaps_unlock(bs);
 365 }
 366
 367 /**
 368  * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
 369  * There must not be any busy bitmaps attached.
 370  * This function does not remove persistent bitmaps from the storage.
 371  * Called with BQL taken.
 372  */
 373 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
 374 {
 375     BdrvDirtyBitmap *bm, *next;
 376
 377     bdrv_dirty_bitmaps_lock(bs);
 378     QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
 379         if (bdrv_dirty_bitmap_name(bm)) {
 380             bdrv_release_dirty_bitmap_locked(bm);
 381         }
 382     }
 383     bdrv_dirty_bitmaps_unlock(bs);
 384 }
 385
 386 /**
 387  * Remove persistent dirty bitmap from the storage if it exists.
 388  * Absence of bitmap is not an error, because we have the following scenario:
 389  * BdrvDirtyBitmap can have .persistent = true but not yet saved and have no
 390  * stored version. For such bitmap bdrv_remove_persistent_dirty_bitmap() should
 391  * not fail.
 392  * This function doesn't release corresponding BdrvDirtyBitmap.
 393  */
 394 static int coroutine_fn
 395 bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
 396                                        Error **errp)
 397 {
 398     if (bs->drv && bs->drv->bdrv_co_remove_persistent_dirty_bitmap) {
 399         return bs->drv->bdrv_co_remove_persistent_dirty_bitmap(bs, name, errp);
 400     }
 401
 402     return 0;
 403 }
 404
 405 typedef struct BdrvRemovePersistentDirtyBitmapCo {
 406     BlockDriverState *bs;
 407     const char *name;
 408     Error **errp;
 409     int ret;
 410 } BdrvRemovePersistentDirtyBitmapCo;
 411
 412 static void coroutine_fn
 413 bdrv_co_remove_persistent_dirty_bitmap_entry(void *opaque)
 414 {
 415     BdrvRemovePersistentDirtyBitmapCo *s = opaque;
 416
 417     s->ret = bdrv_co_remove_persistent_dirty_bitmap(s->bs, s->name, s->errp);
 418     aio_wait_kick();
 419 }
 420
 421 int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name,
 422                                         Error **errp)
 423 {
 424     if (qemu_in_coroutine()) {
 425         return bdrv_co_remove_persistent_dirty_bitmap(bs, name, errp);
 426     } else {
 427         Coroutine *co;
 428         BdrvRemovePersistentDirtyBitmapCo s = {
 429             .bs = bs,
 430             .name = name,
 431             .errp = errp,
 432             .ret = -EINPROGRESS,
 433         };
 434
 435         co = qemu_coroutine_create(bdrv_co_remove_persistent_dirty_bitmap_entry,
 436                                    &s);
 437         bdrv_coroutine_enter(bs, co);
 438         BDRV_POLL_WHILE(bs, s.ret == -EINPROGRESS);
 439
 440         return s.ret;
 441     }
 442 }
 443
 444 bool
 445 bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs)
 446 {
 447     if (bs->drv && bs->drv->bdrv_supports_persistent_dirty_bitmap) {
 448         return bs->drv->bdrv_supports_persistent_dirty_bitmap(bs);
 449     }
 450     return false;
 451 }
 452
 453 static bool coroutine_fn
 454 bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
 455                                    uint32_t granularity, Error **errp)
 456 {
 457     BlockDriver *drv = bs->drv;
 458
 459     if (!drv) {
 460         error_setg_errno(errp, ENOMEDIUM,
 461                          "Can't store persistent bitmaps to %s",
 462                          bdrv_get_device_or_node_name(bs));
 463         return false;
 464     }
 465
 466     if (!drv->bdrv_co_can_store_new_dirty_bitmap) {
 467         error_setg_errno(errp, ENOTSUP,
 468                          "Can't store persistent bitmaps to %s",
 469                          bdrv_get_device_or_node_name(bs));
 470         return false;
 471     }
 472
 473     return drv->bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, errp);
 474 }
 475
 476 typedef struct BdrvCanStoreNewDirtyBitmapCo {
 477     BlockDriverState *bs;
 478     const char *name;
 479     uint32_t granularity;
 480     Error **errp;
 481     bool ret;
 482
 483     bool in_progress;
 484 } BdrvCanStoreNewDirtyBitmapCo;
 485
 486 static void coroutine_fn bdrv_co_can_store_new_dirty_bitmap_entry(void *opaque)
 487 {
 488     BdrvCanStoreNewDirtyBitmapCo *s = opaque;
 489
 490     s->ret = bdrv_co_can_store_new_dirty_bitmap(s->bs, s->name, s->granularity,
 491                                                 s->errp);
 492     s->in_progress = false;
 493     aio_wait_kick();
 494 }
 495
 496 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
 497                                      uint32_t granularity, Error **errp)
 498 {
 499     if (qemu_in_coroutine()) {
 500         return bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, errp);
 501     } else {
 502         Coroutine *co;
 503         BdrvCanStoreNewDirtyBitmapCo s = {
 504             .bs = bs,
 505             .name = name,
 506             .granularity = granularity,
 507             .errp = errp,
 508             .in_progress = true,
 509         };
 510
 511         co = qemu_coroutine_create(bdrv_co_can_store_new_dirty_bitmap_entry,
 512                                    &s);
 513         bdrv_coroutine_enter(bs, co);
 514         BDRV_POLL_WHILE(bs, s.in_progress);
 515
 516         return s.ret;
 517     }
 518 }
 519
 520 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 521 {
 522     bdrv_dirty_bitmaps_lock(bitmap->bs);
 523     bitmap->disabled = true;
 524     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 525 }
 526
 527 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 528 {
 529     bdrv_dirty_bitmaps_lock(bitmap->bs);
 530     bdrv_enable_dirty_bitmap_locked(bitmap);
 531     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 532 }
 533
 534 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
 535 {
 536     BdrvDirtyBitmap *bm;
 537     BlockDirtyInfoList *list = NULL;
 538     BlockDirtyInfoList **tail = &list;
 539
 540     bdrv_dirty_bitmaps_lock(bs);
 541     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 542         BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
 543
 544         info->count = bdrv_get_dirty_count(bm);
 545         info->granularity = bdrv_dirty_bitmap_granularity(bm);
 546         info->has_name = !!bm->name;
 547         info->name = g_strdup(bm->name);
 548         info->recording = bdrv_dirty_bitmap_recording(bm);
 549         info->busy = bdrv_dirty_bitmap_busy(bm);
 550         info->persistent = bm->persistent;
 551         info->has_inconsistent = bm->inconsistent;
 552         info->inconsistent = bm->inconsistent;
 553         QAPI_LIST_APPEND(tail, info);
 554     }
 555     bdrv_dirty_bitmaps_unlock(bs);
 556
 557     return list;
 558 }
 559
 560 /* Called within bdrv_dirty_bitmap_lock..unlock */
 561 bool bdrv_dirty_bitmap_get_locked(BdrvDirtyBitmap *bitmap, int64_t offset)
 562 {
 563     return hbitmap_get(bitmap->bitmap, offset);
 564 }
 565
 566 bool bdrv_dirty_bitmap_get(BdrvDirtyBitmap *bitmap, int64_t offset)
 567 {
 568     bool ret;
 569     bdrv_dirty_bitmaps_lock(bitmap->bs);
 570     ret = bdrv_dirty_bitmap_get_locked(bitmap, offset);
 571     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 572
 573     return ret;
 574 }
 575
 576 /**
 577  * Chooses a default granularity based on the existing cluster size,
 578  * but clamped between [4K, 64K]. Defaults to 64K in the case that there
 579  * is no cluster size information available.
 580  */
 581 uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
 582 {
 583     BlockDriverInfo bdi;
 584     uint32_t granularity;
 585
 586     if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) {
 587         granularity = MAX(4096, bdi.cluster_size);
 588         granularity = MIN(65536, granularity);
 589     } else {
 590         granularity = 65536;
 591     }
 592
 593     return granularity;
 594 }
 595
 596 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap)
 597 {
 598     return 1U << hbitmap_granularity(bitmap->bitmap);
 599 }
 600
 601 BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap)
 602 {
 603     BdrvDirtyBitmapIter *iter = g_new(BdrvDirtyBitmapIter, 1);
 604     hbitmap_iter_init(&iter->hbi, bitmap->bitmap, 0);
 605     iter->bitmap = bitmap;
 606     bitmap->active_iterators++;
 607     return iter;
 608 }
 609
 610 void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
 611 {
 612     if (!iter) {
 613         return;
 614     }
 615     assert(iter->bitmap->active_iterators > 0);
 616     iter->bitmap->active_iterators--;
 617     g_free(iter);
 618 }
 619
 620 int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
 621 {
 622     return hbitmap_iter_next(&iter->hbi);
 623 }
 624
 625 /* Called within bdrv_dirty_bitmap_lock..unlock */
 626 void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 627                                   int64_t offset, int64_t bytes)
 628 {
 629     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 630     hbitmap_set(bitmap->bitmap, offset, bytes);
 631 }
 632
 633 void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 634                            int64_t offset, int64_t bytes)
 635 {
 636     bdrv_dirty_bitmaps_lock(bitmap->bs);
 637     bdrv_set_dirty_bitmap_locked(bitmap, offset, bytes);
 638     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 639 }
 640
 641 /* Called within bdrv_dirty_bitmap_lock..unlock */
 642 void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
 643                                     int64_t offset, int64_t bytes)
 644 {
 645     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 646     hbitmap_reset(bitmap->bitmap, offset, bytes);
 647 }
 648
 649 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
 650                              int64_t offset, int64_t bytes)
 651 {
 652     bdrv_dirty_bitmaps_lock(bitmap->bs);
 653     bdrv_reset_dirty_bitmap_locked(bitmap, offset, bytes);
 654     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 655 }
 656
 657 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
 658 {
 659     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 660     bdrv_dirty_bitmaps_lock(bitmap->bs);
 661     if (!out) {
 662         hbitmap_reset_all(bitmap->bitmap);
 663     } else {
 664         HBitmap *backup = bitmap->bitmap;
 665         bitmap->bitmap = hbitmap_alloc(bitmap->size,
 666                                        hbitmap_granularity(backup));
 667         *out = backup;
 668     }
 669     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 670 }
 671
 672 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup)
 673 {
 674     HBitmap *tmp = bitmap->bitmap;
 675     assert(!bdrv_dirty_bitmap_readonly(bitmap));
 676     bitmap->bitmap = backup;
 677     hbitmap_free(tmp);
 678 }
 679
 680 uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap,
 681                                               uint64_t offset, uint64_t bytes)
 682 {
 683     return hbitmap_serialization_size(bitmap->bitmap, offset, bytes);
 684 }
 685
 686 uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap)
 687 {
 688     return hbitmap_serialization_align(bitmap->bitmap);
 689 }
 690
 691 /* Return the disk size covered by a chunk of serialized bitmap data. */
 692 uint64_t bdrv_dirty_bitmap_serialization_coverage(int serialized_chunk_size,
 693                                                   const BdrvDirtyBitmap *bitmap)
 694 {
 695     uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap);
 696     uint64_t limit = granularity * (serialized_chunk_size << 3);
 697
 698     assert(QEMU_IS_ALIGNED(limit,
 699                            bdrv_dirty_bitmap_serialization_align(bitmap)));
 700     return limit;
 701 }
 702
 703
 704 void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap,
 705                                       uint8_t *buf, uint64_t offset,
 706                                       uint64_t bytes)
 707 {
 708     hbitmap_serialize_part(bitmap->bitmap, buf, offset, bytes);
 709 }
 710
 711 void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap,
 712                                         uint8_t *buf, uint64_t offset,
 713                                         uint64_t bytes, bool finish)
 714 {
 715     hbitmap_deserialize_part(bitmap->bitmap, buf, offset, bytes, finish);
 716 }
 717
 718 void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap,
 719                                           uint64_t offset, uint64_t bytes,
 720                                           bool finish)
 721 {
 722     hbitmap_deserialize_zeroes(bitmap->bitmap, offset, bytes, finish);
 723 }
 724
 725 void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap,
 726                                         uint64_t offset, uint64_t bytes,
 727                                         bool finish)
 728 {
 729     hbitmap_deserialize_ones(bitmap->bitmap, offset, bytes, finish);
 730 }
 731
 732 void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap)
 733 {
 734     hbitmap_deserialize_finish(bitmap->bitmap);
 735 }
 736
 737 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes)
 738 {
 739     BdrvDirtyBitmap *bitmap;
 740
 741     if (QLIST_EMPTY(&bs->dirty_bitmaps)) {
 742         return;
 743     }
 744
 745     bdrv_dirty_bitmaps_lock(bs);
 746     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
 747         if (!bdrv_dirty_bitmap_enabled(bitmap)) {
 748             continue;
 749         }
 750         assert(!bdrv_dirty_bitmap_readonly(bitmap));
 751         hbitmap_set(bitmap->bitmap, offset, bytes);
 752     }
 753     bdrv_dirty_bitmaps_unlock(bs);
 754 }
 755
 756 /**
 757  * Advance a BdrvDirtyBitmapIter to an arbitrary offset.
 758  */
 759 void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *iter, int64_t offset)
 760 {
 761     hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset);
 762 }
 763
 764 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
 765 {
 766     return hbitmap_count(bitmap->bitmap);
 767 }
 768
 769 bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap)
 770 {
 771     return bitmap->readonly;
 772 }
 773
 774 /* Called with BQL taken. */
 775 void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value)
 776 {
 777     bdrv_dirty_bitmaps_lock(bitmap->bs);
 778     bitmap->readonly = value;
 779     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 780 }
 781
 782 bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
 783 {
 784     BdrvDirtyBitmap *bm;
 785     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 786         if (bm->readonly) {
 787             return true;
 788         }
 789     }
 790
 791     return false;
 792 }
 793
 794 bool bdrv_has_named_bitmaps(BlockDriverState *bs)
 795 {
 796     BdrvDirtyBitmap *bm;
 797
 798     QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
 799         if (bdrv_dirty_bitmap_name(bm)) {
 800             return true;
 801         }
 802     }
 803
 804     return false;
 805 }
 806
 807 /* Called with BQL taken. */
 808 void bdrv_dirty_bitmap_set_persistence(BdrvDirtyBitmap *bitmap, bool persistent)
 809 {
 810     bdrv_dirty_bitmaps_lock(bitmap->bs);
 811     bitmap->persistent = persistent;
 812     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 813 }
 814
 815 /* Called with BQL taken. */
 816 void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap)
 817 {
 818     bdrv_dirty_bitmaps_lock(bitmap->bs);
 819     assert(bitmap->persistent == true);
 820     bitmap->inconsistent = true;
 821     bitmap->disabled = true;
 822     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 823 }
 824
 825 /* Called with BQL taken. */
 826 void bdrv_dirty_bitmap_skip_store(BdrvDirtyBitmap *bitmap, bool skip)
 827 {
 828     bdrv_dirty_bitmaps_lock(bitmap->bs);
 829     bitmap->skip_store = skip;
 830     bdrv_dirty_bitmaps_unlock(bitmap->bs);
 831 }
 832
 833 bool bdrv_dirty_bitmap_get_persistence(BdrvDirtyBitmap *bitmap)
 834 {
 835     return bitmap->persistent && !bitmap->skip_store;
 836 }
 837
 838 bool bdrv_dirty_bitmap_inconsistent(const BdrvDirtyBitmap *bitmap)
 839 {
 840     return bitmap->inconsistent;
 841 }
 842
 843 BdrvDirtyBitmap *bdrv_dirty_bitmap_first(BlockDriverState *bs)
 844 {
 845     return QLIST_FIRST(&bs->dirty_bitmaps);
 846 }
 847
 848 BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BdrvDirtyBitmap *bitmap)
 849 {
 850     return QLIST_NEXT(bitmap, list);
 851 }
 852
 853 char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp)
 854 {
 855     return hbitmap_sha256(bitmap->bitmap, errp);
 856 }
 857
 858 int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset,
 859                                      int64_t bytes)
 860 {
 861     return hbitmap_next_dirty(bitmap->bitmap, offset, bytes);
 862 }
 863
 864 int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset,
 865                                     int64_t bytes)
 866 {
 867     return hbitmap_next_zero(bitmap->bitmap, offset, bytes);
 868 }
 869
 870 bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap,
 871         int64_t start, int64_t end, int64_t max_dirty_count,
 872         int64_t *dirty_start, int64_t *dirty_count)
 873 {
 874     return hbitmap_next_dirty_area(bitmap->bitmap, start, end, max_dirty_count,
 875                                    dirty_start, dirty_count);
 876 }
 877
 878 /**
 879  * bdrv_merge_dirty_bitmap: merge src into dest.
 880  * Ensures permissions on bitmaps are reasonable; use for public API.
 881  *
 882  * @backup: If provided, make a copy of dest here prior to merge.
 883  */
 884 void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src,
 885                              HBitmap **backup, Error **errp)
 886 {
 887     bool ret;
 888
 889     bdrv_dirty_bitmaps_lock(dest->bs);
 890     if (src->bs != dest->bs) {
 891         bdrv_dirty_bitmaps_lock(src->bs);
 892     }
 893
 894     if (bdrv_dirty_bitmap_check(dest, BDRV_BITMAP_DEFAULT, errp)) {
 895         goto out;
 896     }
 897
 898     if (bdrv_dirty_bitmap_check(src, BDRV_BITMAP_ALLOW_RO, errp)) {
 899         goto out;
 900     }
 901
 902     if (!hbitmap_can_merge(dest->bitmap, src->bitmap)) {
 903         error_setg(errp, "Bitmaps are incompatible and can't be merged");
 904         goto out;
 905     }
 906
 907     ret = bdrv_dirty_bitmap_merge_internal(dest, src, backup, false);
 908     assert(ret);
 909
 910 out:
 911     bdrv_dirty_bitmaps_unlock(dest->bs);
 912     if (src->bs != dest->bs) {
 913         bdrv_dirty_bitmaps_unlock(src->bs);
 914     }
 915 }
 916
 917 /**
 918  * bdrv_dirty_bitmap_merge_internal: merge src into dest.
 919  * Does NOT check bitmap permissions; not suitable for use as public API.
 920  *
 921  * @backup: If provided, make a copy of dest here prior to merge.
 922  * @lock: If true, lock and unlock bitmaps on the way in/out.
 923  * returns true if the merge succeeded; false if unattempted.
 924  */
 925 bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
 926                                       const BdrvDirtyBitmap *src,
 927                                       HBitmap **backup,
 928                                       bool lock)
 929 {
 930     bool ret;
 931
 932     assert(!bdrv_dirty_bitmap_readonly(dest));
 933     assert(!bdrv_dirty_bitmap_inconsistent(dest));
 934     assert(!bdrv_dirty_bitmap_inconsistent(src));
 935
 936     if (lock) {
 937         bdrv_dirty_bitmaps_lock(dest->bs);
 938         if (src->bs != dest->bs) {
 939             bdrv_dirty_bitmaps_lock(src->bs);
 940         }
 941     }
 942
 943     if (backup) {
 944         *backup = dest->bitmap;
 945         dest->bitmap = hbitmap_alloc(dest->size, hbitmap_granularity(*backup));
 946         ret = hbitmap_merge(*backup, src->bitmap, dest->bitmap);
 947     } else {
 948         ret = hbitmap_merge(dest->bitmap, src->bitmap, dest->bitmap);
 949     }
 950
 951     if (lock) {
 952         bdrv_dirty_bitmaps_unlock(dest->bs);
 953         if (src->bs != dest->bs) {
 954             bdrv_dirty_bitmaps_unlock(src->bs);
 955         }
 956     }
 957
 958     return ret;
 959 }