| 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-io.h" |
| 28 | #include "block/block_int.h" |
| 29 | #include "block/blockjob.h" |
| 30 | #include "block/dirty-bitmap.h" |
| 31 | #include "qemu/main-loop.h" |
| 32 | |
| 33 | struct BdrvDirtyBitmap { |
| 34 | BlockDriverState *bs; |
| 35 | HBitmap *bitmap; /* Dirty bitmap implementation */ |
| 36 | bool busy; /* Bitmap is busy, it can't be used via QMP */ |
| 37 | BdrvDirtyBitmap *successor; /* Anonymous child, if any. */ |
| 38 | char *name; /* Optional non-empty unique ID */ |
| 39 | int64_t size; /* Size of the bitmap, in bytes */ |
| 40 | bool disabled; /* Bitmap is disabled. It ignores all writes to |
| 41 | the device */ |
| 42 | int active_iterators; /* How many iterators are active */ |
| 43 | bool readonly; /* Bitmap is read-only. This field also |
| 44 | prevents the respective image from being |
| 45 | modified (i.e. blocks writes and discards). |
| 46 | Such operations must fail and both the image |
| 47 | and this bitmap must remain unchanged while |
| 48 | this flag is set. */ |
| 49 | bool persistent; /* bitmap must be saved to owner disk image */ |
| 50 | bool inconsistent; /* bitmap is persistent, but inconsistent. |
| 51 | It cannot be used at all in any way, except |
| 52 | a QMP user can remove it. */ |
| 53 | bool skip_store; /* We are either migrating or deleting this |
| 54 | * bitmap; it should not be stored on the next |
| 55 | * inactivation. */ |
| 56 | QLIST_ENTRY(BdrvDirtyBitmap) list; |
| 57 | }; |
| 58 | |
| 59 | struct BdrvDirtyBitmapIter { |
| 60 | HBitmapIter hbi; |
| 61 | BdrvDirtyBitmap *bitmap; |
| 62 | }; |
| 63 | |
| 64 | static inline void bdrv_dirty_bitmaps_lock(BlockDriverState *bs) |
| 65 | { |
| 66 | qemu_mutex_lock(&bs->dirty_bitmap_mutex); |
| 67 | } |
| 68 | |
| 69 | static inline void bdrv_dirty_bitmaps_unlock(BlockDriverState *bs) |
| 70 | { |
| 71 | qemu_mutex_unlock(&bs->dirty_bitmap_mutex); |
| 72 | } |
| 73 | |
| 74 | void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap) |
| 75 | { |
| 76 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 77 | } |
| 78 | |
| 79 | void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap) |
| 80 | { |
| 81 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 82 | } |
| 83 | |
| 84 | /* Called with BQL or dirty_bitmap lock taken. */ |
| 85 | BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name) |
| 86 | { |
| 87 | BdrvDirtyBitmap *bm; |
| 88 | |
| 89 | assert(name); |
| 90 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
| 91 | if (bm->name && !strcmp(name, bm->name)) { |
| 92 | return bm; |
| 93 | } |
| 94 | } |
| 95 | return NULL; |
| 96 | } |
| 97 | |
| 98 | /* Called with BQL taken. */ |
| 99 | BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, |
| 100 | uint32_t granularity, |
| 101 | const char *name, |
| 102 | Error **errp) |
| 103 | { |
| 104 | int64_t bitmap_size; |
| 105 | BdrvDirtyBitmap *bitmap; |
| 106 | |
| 107 | assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE); |
| 108 | |
| 109 | if (name) { |
| 110 | if (bdrv_find_dirty_bitmap(bs, name)) { |
| 111 | error_setg(errp, "Bitmap already exists: %s", name); |
| 112 | return NULL; |
| 113 | } |
| 114 | if (strlen(name) > BDRV_BITMAP_MAX_NAME_SIZE) { |
| 115 | error_setg(errp, "Bitmap name too long: %s", name); |
| 116 | return NULL; |
| 117 | } |
| 118 | } |
| 119 | bitmap_size = bdrv_getlength(bs); |
| 120 | if (bitmap_size < 0) { |
| 121 | error_setg_errno(errp, -bitmap_size, "could not get length of device"); |
| 122 | errno = -bitmap_size; |
| 123 | return NULL; |
| 124 | } |
| 125 | bitmap = g_new0(BdrvDirtyBitmap, 1); |
| 126 | bitmap->bs = bs; |
| 127 | bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(granularity)); |
| 128 | bitmap->size = bitmap_size; |
| 129 | bitmap->name = g_strdup(name); |
| 130 | bitmap->disabled = false; |
| 131 | bdrv_dirty_bitmaps_lock(bs); |
| 132 | QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); |
| 133 | bdrv_dirty_bitmaps_unlock(bs); |
| 134 | return bitmap; |
| 135 | } |
| 136 | |
| 137 | int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap) |
| 138 | { |
| 139 | return bitmap->size; |
| 140 | } |
| 141 | |
| 142 | const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap) |
| 143 | { |
| 144 | return bitmap->name; |
| 145 | } |
| 146 | |
| 147 | /* Called with BQL taken. */ |
| 148 | bool bdrv_dirty_bitmap_has_successor(BdrvDirtyBitmap *bitmap) |
| 149 | { |
| 150 | return bitmap->successor; |
| 151 | } |
| 152 | |
| 153 | static bool bdrv_dirty_bitmap_busy(const BdrvDirtyBitmap *bitmap) |
| 154 | { |
| 155 | return bitmap->busy; |
| 156 | } |
| 157 | |
| 158 | void bdrv_dirty_bitmap_set_busy(BdrvDirtyBitmap *bitmap, bool busy) |
| 159 | { |
| 160 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 161 | bitmap->busy = busy; |
| 162 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 163 | } |
| 164 | |
| 165 | /* Called with BQL taken. */ |
| 166 | bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap) |
| 167 | { |
| 168 | return !bitmap->disabled; |
| 169 | } |
| 170 | |
| 171 | /* Called with BQL taken. */ |
| 172 | static bool bdrv_dirty_bitmap_recording(BdrvDirtyBitmap *bitmap) |
| 173 | { |
| 174 | return !bitmap->disabled || (bitmap->successor && |
| 175 | !bitmap->successor->disabled); |
| 176 | } |
| 177 | |
| 178 | int bdrv_dirty_bitmap_check(const BdrvDirtyBitmap *bitmap, uint32_t flags, |
| 179 | Error **errp) |
| 180 | { |
| 181 | if ((flags & BDRV_BITMAP_BUSY) && bdrv_dirty_bitmap_busy(bitmap)) { |
| 182 | error_setg(errp, "Bitmap '%s' is currently in use by another" |
| 183 | " operation and cannot be used", bitmap->name); |
| 184 | return -1; |
| 185 | } |
| 186 | |
| 187 | if ((flags & BDRV_BITMAP_RO) && bdrv_dirty_bitmap_readonly(bitmap)) { |
| 188 | error_setg(errp, "Bitmap '%s' is readonly and cannot be modified", |
| 189 | bitmap->name); |
| 190 | return -1; |
| 191 | } |
| 192 | |
| 193 | if ((flags & BDRV_BITMAP_INCONSISTENT) && |
| 194 | bdrv_dirty_bitmap_inconsistent(bitmap)) { |
| 195 | error_setg(errp, "Bitmap '%s' is inconsistent and cannot be used", |
| 196 | bitmap->name); |
| 197 | error_append_hint(errp, "Try block-dirty-bitmap-remove to delete" |
| 198 | " this bitmap from disk\n"); |
| 199 | return -1; |
| 200 | } |
| 201 | |
| 202 | return 0; |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * Create a successor bitmap destined to replace this bitmap after an operation. |
| 207 | * Requires that the bitmap is not marked busy and has no successor. |
| 208 | * The successor will be enabled if the parent bitmap was. |
| 209 | * Called with BQL taken. |
| 210 | */ |
| 211 | int bdrv_dirty_bitmap_create_successor(BdrvDirtyBitmap *bitmap, Error **errp) |
| 212 | { |
| 213 | uint64_t granularity; |
| 214 | BdrvDirtyBitmap *child; |
| 215 | |
| 216 | if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_BUSY, errp)) { |
| 217 | return -1; |
| 218 | } |
| 219 | if (bdrv_dirty_bitmap_has_successor(bitmap)) { |
| 220 | error_setg(errp, "Cannot create a successor for a bitmap that already " |
| 221 | "has one"); |
| 222 | return -1; |
| 223 | } |
| 224 | |
| 225 | /* Create an anonymous successor */ |
| 226 | granularity = bdrv_dirty_bitmap_granularity(bitmap); |
| 227 | child = bdrv_create_dirty_bitmap(bitmap->bs, granularity, NULL, errp); |
| 228 | if (!child) { |
| 229 | return -1; |
| 230 | } |
| 231 | |
| 232 | /* Successor will be on or off based on our current state. */ |
| 233 | child->disabled = bitmap->disabled; |
| 234 | bitmap->disabled = true; |
| 235 | |
| 236 | /* Install the successor and mark the parent as busy */ |
| 237 | bitmap->successor = child; |
| 238 | bitmap->busy = true; |
| 239 | return 0; |
| 240 | } |
| 241 | |
| 242 | void bdrv_enable_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap) |
| 243 | { |
| 244 | bitmap->disabled = false; |
| 245 | } |
| 246 | |
| 247 | /* Called with BQL taken. */ |
| 248 | void bdrv_dirty_bitmap_enable_successor(BdrvDirtyBitmap *bitmap) |
| 249 | { |
| 250 | assert(bitmap->bs == bitmap->successor->bs); |
| 251 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 252 | bdrv_enable_dirty_bitmap_locked(bitmap->successor); |
| 253 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 254 | } |
| 255 | |
| 256 | /* Called within bdrv_dirty_bitmap_lock..unlock and with BQL taken. */ |
| 257 | static void bdrv_release_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap) |
| 258 | { |
| 259 | assert(!bitmap->active_iterators); |
| 260 | assert(!bdrv_dirty_bitmap_busy(bitmap)); |
| 261 | assert(!bdrv_dirty_bitmap_has_successor(bitmap)); |
| 262 | QLIST_REMOVE(bitmap, list); |
| 263 | hbitmap_free(bitmap->bitmap); |
| 264 | g_free(bitmap->name); |
| 265 | g_free(bitmap); |
| 266 | } |
| 267 | |
| 268 | /** |
| 269 | * For a bitmap with a successor, yield our name to the successor, |
| 270 | * delete the old bitmap, and return a handle to the new bitmap. |
| 271 | * Called with BQL taken. |
| 272 | */ |
| 273 | BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BdrvDirtyBitmap *bitmap, |
| 274 | Error **errp) |
| 275 | { |
| 276 | char *name; |
| 277 | BdrvDirtyBitmap *successor = bitmap->successor; |
| 278 | |
| 279 | if (successor == NULL) { |
| 280 | error_setg(errp, "Cannot relinquish control if " |
| 281 | "there's no successor present"); |
| 282 | return NULL; |
| 283 | } |
| 284 | |
| 285 | name = bitmap->name; |
| 286 | bitmap->name = NULL; |
| 287 | successor->name = name; |
| 288 | bitmap->successor = NULL; |
| 289 | successor->persistent = bitmap->persistent; |
| 290 | bitmap->persistent = false; |
| 291 | bitmap->busy = false; |
| 292 | bdrv_release_dirty_bitmap(bitmap); |
| 293 | |
| 294 | return successor; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * In cases of failure where we can no longer safely delete the parent, |
| 299 | * we may wish to re-join the parent and child/successor. |
| 300 | * The merged parent will be marked as not busy. |
| 301 | * The marged parent will be enabled if and only if the successor was enabled. |
| 302 | * Called within bdrv_dirty_bitmap_lock..unlock and with BQL taken. |
| 303 | */ |
| 304 | BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap_locked(BdrvDirtyBitmap *parent, |
| 305 | Error **errp) |
| 306 | { |
| 307 | BdrvDirtyBitmap *successor = parent->successor; |
| 308 | |
| 309 | if (!successor) { |
| 310 | error_setg(errp, "Cannot reclaim a successor when none is present"); |
| 311 | return NULL; |
| 312 | } |
| 313 | |
| 314 | hbitmap_merge(parent->bitmap, successor->bitmap, parent->bitmap); |
| 315 | |
| 316 | parent->disabled = successor->disabled; |
| 317 | parent->busy = false; |
| 318 | bdrv_release_dirty_bitmap_locked(successor); |
| 319 | parent->successor = NULL; |
| 320 | |
| 321 | return parent; |
| 322 | } |
| 323 | |
| 324 | /* Called with BQL taken. */ |
| 325 | BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BdrvDirtyBitmap *parent, |
| 326 | Error **errp) |
| 327 | { |
| 328 | BdrvDirtyBitmap *ret; |
| 329 | |
| 330 | bdrv_dirty_bitmaps_lock(parent->bs); |
| 331 | ret = bdrv_reclaim_dirty_bitmap_locked(parent, errp); |
| 332 | bdrv_dirty_bitmaps_unlock(parent->bs); |
| 333 | |
| 334 | return ret; |
| 335 | } |
| 336 | |
| 337 | /** |
| 338 | * Truncates _all_ bitmaps attached to a BDS. |
| 339 | * Called with BQL taken. |
| 340 | */ |
| 341 | void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes) |
| 342 | { |
| 343 | BdrvDirtyBitmap *bitmap; |
| 344 | |
| 345 | bdrv_dirty_bitmaps_lock(bs); |
| 346 | QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { |
| 347 | assert(!bdrv_dirty_bitmap_busy(bitmap)); |
| 348 | assert(!bdrv_dirty_bitmap_has_successor(bitmap)); |
| 349 | assert(!bitmap->active_iterators); |
| 350 | hbitmap_truncate(bitmap->bitmap, bytes); |
| 351 | bitmap->size = bytes; |
| 352 | } |
| 353 | bdrv_dirty_bitmaps_unlock(bs); |
| 354 | } |
| 355 | |
| 356 | /* Called with BQL taken. */ |
| 357 | void bdrv_release_dirty_bitmap(BdrvDirtyBitmap *bitmap) |
| 358 | { |
| 359 | BlockDriverState *bs = bitmap->bs; |
| 360 | |
| 361 | bdrv_dirty_bitmaps_lock(bs); |
| 362 | bdrv_release_dirty_bitmap_locked(bitmap); |
| 363 | bdrv_dirty_bitmaps_unlock(bs); |
| 364 | } |
| 365 | |
| 366 | /** |
| 367 | * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()). |
| 368 | * There must not be any busy bitmaps attached. |
| 369 | * This function does not remove persistent bitmaps from the storage. |
| 370 | * Called with BQL taken. |
| 371 | */ |
| 372 | void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs) |
| 373 | { |
| 374 | BdrvDirtyBitmap *bm, *next; |
| 375 | |
| 376 | bdrv_dirty_bitmaps_lock(bs); |
| 377 | QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { |
| 378 | if (bdrv_dirty_bitmap_name(bm)) { |
| 379 | bdrv_release_dirty_bitmap_locked(bm); |
| 380 | } |
| 381 | } |
| 382 | bdrv_dirty_bitmaps_unlock(bs); |
| 383 | } |
| 384 | |
| 385 | /** |
| 386 | * Remove persistent dirty bitmap from the storage if it exists. |
| 387 | * Absence of bitmap is not an error, because we have the following scenario: |
| 388 | * BdrvDirtyBitmap can have .persistent = true but not yet saved and have no |
| 389 | * stored version. For such bitmap bdrv_remove_persistent_dirty_bitmap() should |
| 390 | * not fail. |
| 391 | * This function doesn't release corresponding BdrvDirtyBitmap. |
| 392 | */ |
| 393 | int coroutine_fn |
| 394 | bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *name, |
| 395 | Error **errp) |
| 396 | { |
| 397 | assert_bdrv_graph_readable(); |
| 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 | bool |
| 406 | bdrv_supports_persistent_dirty_bitmap(BlockDriverState *bs) |
| 407 | { |
| 408 | if (bs->drv && bs->drv->bdrv_supports_persistent_dirty_bitmap) { |
| 409 | return bs->drv->bdrv_supports_persistent_dirty_bitmap(bs); |
| 410 | } |
| 411 | return false; |
| 412 | } |
| 413 | |
| 414 | bool coroutine_fn |
| 415 | bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, |
| 416 | uint32_t granularity, Error **errp) |
| 417 | { |
| 418 | BlockDriver *drv = bs->drv; |
| 419 | assert_bdrv_graph_readable(); |
| 420 | |
| 421 | if (!drv) { |
| 422 | error_setg_errno(errp, ENOMEDIUM, |
| 423 | "Can't store persistent bitmaps to %s", |
| 424 | bdrv_get_device_or_node_name(bs)); |
| 425 | return false; |
| 426 | } |
| 427 | |
| 428 | if (!drv->bdrv_co_can_store_new_dirty_bitmap) { |
| 429 | error_setg_errno(errp, ENOTSUP, |
| 430 | "Can't store persistent bitmaps to %s", |
| 431 | bdrv_get_device_or_node_name(bs)); |
| 432 | return false; |
| 433 | } |
| 434 | |
| 435 | return drv->bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, errp); |
| 436 | } |
| 437 | |
| 438 | void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap) |
| 439 | { |
| 440 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 441 | bitmap->disabled = true; |
| 442 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 443 | } |
| 444 | |
| 445 | void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap) |
| 446 | { |
| 447 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 448 | bdrv_enable_dirty_bitmap_locked(bitmap); |
| 449 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 450 | } |
| 451 | |
| 452 | BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) |
| 453 | { |
| 454 | BdrvDirtyBitmap *bm; |
| 455 | BlockDirtyInfoList *list = NULL; |
| 456 | BlockDirtyInfoList **tail = &list; |
| 457 | |
| 458 | bdrv_dirty_bitmaps_lock(bs); |
| 459 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
| 460 | BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1); |
| 461 | |
| 462 | info->count = bdrv_get_dirty_count(bm); |
| 463 | info->granularity = bdrv_dirty_bitmap_granularity(bm); |
| 464 | info->name = g_strdup(bm->name); |
| 465 | info->recording = bdrv_dirty_bitmap_recording(bm); |
| 466 | info->busy = bdrv_dirty_bitmap_busy(bm); |
| 467 | info->persistent = bm->persistent; |
| 468 | info->has_inconsistent = bm->inconsistent; |
| 469 | info->inconsistent = bm->inconsistent; |
| 470 | QAPI_LIST_APPEND(tail, info); |
| 471 | } |
| 472 | bdrv_dirty_bitmaps_unlock(bs); |
| 473 | |
| 474 | return list; |
| 475 | } |
| 476 | |
| 477 | /* Called within bdrv_dirty_bitmap_lock..unlock */ |
| 478 | bool bdrv_dirty_bitmap_get_locked(BdrvDirtyBitmap *bitmap, int64_t offset) |
| 479 | { |
| 480 | return hbitmap_get(bitmap->bitmap, offset); |
| 481 | } |
| 482 | |
| 483 | bool bdrv_dirty_bitmap_get(BdrvDirtyBitmap *bitmap, int64_t offset) |
| 484 | { |
| 485 | bool ret; |
| 486 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 487 | ret = bdrv_dirty_bitmap_get_locked(bitmap, offset); |
| 488 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 489 | |
| 490 | return ret; |
| 491 | } |
| 492 | |
| 493 | /** |
| 494 | * Chooses a default granularity based on the existing cluster size, |
| 495 | * but clamped between [4K, 64K]. Defaults to 64K in the case that there |
| 496 | * is no cluster size information available. |
| 497 | */ |
| 498 | uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs) |
| 499 | { |
| 500 | BlockDriverInfo bdi; |
| 501 | uint32_t granularity; |
| 502 | |
| 503 | if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) { |
| 504 | granularity = MAX(4096, bdi.cluster_size); |
| 505 | granularity = MIN(65536, granularity); |
| 506 | } else { |
| 507 | granularity = 65536; |
| 508 | } |
| 509 | |
| 510 | return granularity; |
| 511 | } |
| 512 | |
| 513 | uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap) |
| 514 | { |
| 515 | return 1U << hbitmap_granularity(bitmap->bitmap); |
| 516 | } |
| 517 | |
| 518 | BdrvDirtyBitmapIter *bdrv_dirty_iter_new(BdrvDirtyBitmap *bitmap) |
| 519 | { |
| 520 | BdrvDirtyBitmapIter *iter = g_new(BdrvDirtyBitmapIter, 1); |
| 521 | hbitmap_iter_init(&iter->hbi, bitmap->bitmap, 0); |
| 522 | iter->bitmap = bitmap; |
| 523 | bitmap->active_iterators++; |
| 524 | return iter; |
| 525 | } |
| 526 | |
| 527 | void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter) |
| 528 | { |
| 529 | if (!iter) { |
| 530 | return; |
| 531 | } |
| 532 | assert(iter->bitmap->active_iterators > 0); |
| 533 | iter->bitmap->active_iterators--; |
| 534 | g_free(iter); |
| 535 | } |
| 536 | |
| 537 | int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter) |
| 538 | { |
| 539 | return hbitmap_iter_next(&iter->hbi); |
| 540 | } |
| 541 | |
| 542 | /* Called within bdrv_dirty_bitmap_lock..unlock */ |
| 543 | void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap, |
| 544 | int64_t offset, int64_t bytes) |
| 545 | { |
| 546 | assert(!bdrv_dirty_bitmap_readonly(bitmap)); |
| 547 | hbitmap_set(bitmap->bitmap, offset, bytes); |
| 548 | } |
| 549 | |
| 550 | void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap, |
| 551 | int64_t offset, int64_t bytes) |
| 552 | { |
| 553 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 554 | bdrv_set_dirty_bitmap_locked(bitmap, offset, bytes); |
| 555 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 556 | } |
| 557 | |
| 558 | /* Called within bdrv_dirty_bitmap_lock..unlock */ |
| 559 | void bdrv_reset_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap, |
| 560 | int64_t offset, int64_t bytes) |
| 561 | { |
| 562 | assert(!bdrv_dirty_bitmap_readonly(bitmap)); |
| 563 | hbitmap_reset(bitmap->bitmap, offset, bytes); |
| 564 | } |
| 565 | |
| 566 | void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, |
| 567 | int64_t offset, int64_t bytes) |
| 568 | { |
| 569 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 570 | bdrv_reset_dirty_bitmap_locked(bitmap, offset, bytes); |
| 571 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 572 | } |
| 573 | |
| 574 | void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) |
| 575 | { |
| 576 | IO_CODE(); |
| 577 | assert(!bdrv_dirty_bitmap_readonly(bitmap)); |
| 578 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 579 | if (!out) { |
| 580 | hbitmap_reset_all(bitmap->bitmap); |
| 581 | } else { |
| 582 | HBitmap *backup = bitmap->bitmap; |
| 583 | bitmap->bitmap = hbitmap_alloc(bitmap->size, |
| 584 | hbitmap_granularity(backup)); |
| 585 | *out = backup; |
| 586 | } |
| 587 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 588 | } |
| 589 | |
| 590 | void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup) |
| 591 | { |
| 592 | HBitmap *tmp = bitmap->bitmap; |
| 593 | assert(!bdrv_dirty_bitmap_readonly(bitmap)); |
| 594 | GLOBAL_STATE_CODE(); |
| 595 | bitmap->bitmap = backup; |
| 596 | hbitmap_free(tmp); |
| 597 | } |
| 598 | |
| 599 | uint64_t bdrv_dirty_bitmap_serialization_size(const BdrvDirtyBitmap *bitmap, |
| 600 | uint64_t offset, uint64_t bytes) |
| 601 | { |
| 602 | return hbitmap_serialization_size(bitmap->bitmap, offset, bytes); |
| 603 | } |
| 604 | |
| 605 | uint64_t bdrv_dirty_bitmap_serialization_align(const BdrvDirtyBitmap *bitmap) |
| 606 | { |
| 607 | return hbitmap_serialization_align(bitmap->bitmap); |
| 608 | } |
| 609 | |
| 610 | /* Return the disk size covered by a chunk of serialized bitmap data. */ |
| 611 | uint64_t bdrv_dirty_bitmap_serialization_coverage(int serialized_chunk_size, |
| 612 | const BdrvDirtyBitmap *bitmap) |
| 613 | { |
| 614 | uint64_t granularity = bdrv_dirty_bitmap_granularity(bitmap); |
| 615 | uint64_t limit = granularity * ((uint64_t)serialized_chunk_size << 3); |
| 616 | |
| 617 | assert(QEMU_IS_ALIGNED(limit, |
| 618 | bdrv_dirty_bitmap_serialization_align(bitmap))); |
| 619 | return limit; |
| 620 | } |
| 621 | |
| 622 | |
| 623 | void bdrv_dirty_bitmap_serialize_part(const BdrvDirtyBitmap *bitmap, |
| 624 | uint8_t *buf, uint64_t offset, |
| 625 | uint64_t bytes) |
| 626 | { |
| 627 | hbitmap_serialize_part(bitmap->bitmap, buf, offset, bytes); |
| 628 | } |
| 629 | |
| 630 | void bdrv_dirty_bitmap_deserialize_part(BdrvDirtyBitmap *bitmap, |
| 631 | uint8_t *buf, uint64_t offset, |
| 632 | uint64_t bytes, bool finish) |
| 633 | { |
| 634 | hbitmap_deserialize_part(bitmap->bitmap, buf, offset, bytes, finish); |
| 635 | } |
| 636 | |
| 637 | void bdrv_dirty_bitmap_deserialize_zeroes(BdrvDirtyBitmap *bitmap, |
| 638 | uint64_t offset, uint64_t bytes, |
| 639 | bool finish) |
| 640 | { |
| 641 | hbitmap_deserialize_zeroes(bitmap->bitmap, offset, bytes, finish); |
| 642 | } |
| 643 | |
| 644 | void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap, |
| 645 | uint64_t offset, uint64_t bytes, |
| 646 | bool finish) |
| 647 | { |
| 648 | hbitmap_deserialize_ones(bitmap->bitmap, offset, bytes, 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 offset, int64_t bytes) |
| 657 | { |
| 658 | BdrvDirtyBitmap *bitmap; |
| 659 | IO_CODE(); |
| 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, offset, bytes); |
| 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 offset) |
| 680 | { |
| 681 | hbitmap_iter_init(&iter->hbi, iter->hbi.hb, offset); |
| 682 | } |
| 683 | |
| 684 | int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap) |
| 685 | { |
| 686 | return hbitmap_count(bitmap->bitmap); |
| 687 | } |
| 688 | |
| 689 | bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap) |
| 690 | { |
| 691 | return bitmap->readonly; |
| 692 | } |
| 693 | |
| 694 | /* Called with BQL taken. */ |
| 695 | void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value) |
| 696 | { |
| 697 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 698 | bitmap->readonly = value; |
| 699 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 700 | } |
| 701 | |
| 702 | bool bdrv_has_readonly_bitmaps(BlockDriverState *bs) |
| 703 | { |
| 704 | BdrvDirtyBitmap *bm; |
| 705 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
| 706 | if (bm->readonly) { |
| 707 | return true; |
| 708 | } |
| 709 | } |
| 710 | |
| 711 | return false; |
| 712 | } |
| 713 | |
| 714 | bool bdrv_has_named_bitmaps(BlockDriverState *bs) |
| 715 | { |
| 716 | BdrvDirtyBitmap *bm; |
| 717 | |
| 718 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
| 719 | if (bdrv_dirty_bitmap_name(bm)) { |
| 720 | return true; |
| 721 | } |
| 722 | } |
| 723 | |
| 724 | return false; |
| 725 | } |
| 726 | |
| 727 | /* Called with BQL taken. */ |
| 728 | void bdrv_dirty_bitmap_set_persistence(BdrvDirtyBitmap *bitmap, bool persistent) |
| 729 | { |
| 730 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 731 | bitmap->persistent = persistent; |
| 732 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 733 | } |
| 734 | |
| 735 | /* Called with BQL taken. */ |
| 736 | void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap) |
| 737 | { |
| 738 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 739 | assert(bitmap->persistent == true); |
| 740 | bitmap->inconsistent = true; |
| 741 | bitmap->disabled = true; |
| 742 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 743 | } |
| 744 | |
| 745 | /* Called with BQL taken. */ |
| 746 | void bdrv_dirty_bitmap_skip_store(BdrvDirtyBitmap *bitmap, bool skip) |
| 747 | { |
| 748 | bdrv_dirty_bitmaps_lock(bitmap->bs); |
| 749 | bitmap->skip_store = skip; |
| 750 | bdrv_dirty_bitmaps_unlock(bitmap->bs); |
| 751 | } |
| 752 | |
| 753 | bool bdrv_dirty_bitmap_get_persistence(BdrvDirtyBitmap *bitmap) |
| 754 | { |
| 755 | return bitmap->persistent && !bitmap->skip_store; |
| 756 | } |
| 757 | |
| 758 | bool bdrv_dirty_bitmap_inconsistent(const BdrvDirtyBitmap *bitmap) |
| 759 | { |
| 760 | return bitmap->inconsistent; |
| 761 | } |
| 762 | |
| 763 | BdrvDirtyBitmap *bdrv_dirty_bitmap_first(BlockDriverState *bs) |
| 764 | { |
| 765 | return QLIST_FIRST(&bs->dirty_bitmaps); |
| 766 | } |
| 767 | |
| 768 | BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BdrvDirtyBitmap *bitmap) |
| 769 | { |
| 770 | return QLIST_NEXT(bitmap, list); |
| 771 | } |
| 772 | |
| 773 | char *bdrv_dirty_bitmap_sha256(const BdrvDirtyBitmap *bitmap, Error **errp) |
| 774 | { |
| 775 | return hbitmap_sha256(bitmap->bitmap, errp); |
| 776 | } |
| 777 | |
| 778 | int64_t bdrv_dirty_bitmap_next_dirty(BdrvDirtyBitmap *bitmap, int64_t offset, |
| 779 | int64_t bytes) |
| 780 | { |
| 781 | return hbitmap_next_dirty(bitmap->bitmap, offset, bytes); |
| 782 | } |
| 783 | |
| 784 | int64_t bdrv_dirty_bitmap_next_zero(BdrvDirtyBitmap *bitmap, int64_t offset, |
| 785 | int64_t bytes) |
| 786 | { |
| 787 | return hbitmap_next_zero(bitmap->bitmap, offset, bytes); |
| 788 | } |
| 789 | |
| 790 | bool bdrv_dirty_bitmap_next_dirty_area(BdrvDirtyBitmap *bitmap, |
| 791 | int64_t start, int64_t end, int64_t max_dirty_count, |
| 792 | int64_t *dirty_start, int64_t *dirty_count) |
| 793 | { |
| 794 | return hbitmap_next_dirty_area(bitmap->bitmap, start, end, max_dirty_count, |
| 795 | dirty_start, dirty_count); |
| 796 | } |
| 797 | |
| 798 | bool bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap, int64_t offset, |
| 799 | int64_t bytes, int64_t *count) |
| 800 | { |
| 801 | return hbitmap_status(bitmap->bitmap, offset, bytes, count); |
| 802 | } |
| 803 | |
| 804 | /** |
| 805 | * bdrv_merge_dirty_bitmap: merge src into dest. |
| 806 | * Ensures permissions on bitmaps are reasonable; use for public API. |
| 807 | * |
| 808 | * @backup: If provided, make a copy of dest here prior to merge. |
| 809 | * |
| 810 | * Returns true on success, false on failure. In case of failure bitmaps are |
| 811 | * untouched. |
| 812 | */ |
| 813 | bool bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap *src, |
| 814 | HBitmap **backup, Error **errp) |
| 815 | { |
| 816 | bool ret = false; |
| 817 | |
| 818 | bdrv_dirty_bitmaps_lock(dest->bs); |
| 819 | if (src->bs != dest->bs) { |
| 820 | bdrv_dirty_bitmaps_lock(src->bs); |
| 821 | } |
| 822 | |
| 823 | if (bdrv_dirty_bitmap_check(dest, BDRV_BITMAP_DEFAULT, errp)) { |
| 824 | goto out; |
| 825 | } |
| 826 | |
| 827 | if (bdrv_dirty_bitmap_check(src, BDRV_BITMAP_ALLOW_RO, errp)) { |
| 828 | goto out; |
| 829 | } |
| 830 | |
| 831 | if (bdrv_dirty_bitmap_size(src) != bdrv_dirty_bitmap_size(dest)) { |
| 832 | error_setg(errp, "Bitmaps are of different sizes (destination size is %" |
| 833 | PRId64 ", source size is %" PRId64 ") and can't be merged", |
| 834 | bdrv_dirty_bitmap_size(dest), bdrv_dirty_bitmap_size(src)); |
| 835 | goto out; |
| 836 | } |
| 837 | |
| 838 | bdrv_dirty_bitmap_merge_internal(dest, src, backup, false); |
| 839 | ret = true; |
| 840 | |
| 841 | out: |
| 842 | bdrv_dirty_bitmaps_unlock(dest->bs); |
| 843 | if (src->bs != dest->bs) { |
| 844 | bdrv_dirty_bitmaps_unlock(src->bs); |
| 845 | } |
| 846 | |
| 847 | return ret; |
| 848 | } |
| 849 | |
| 850 | /** |
| 851 | * bdrv_dirty_bitmap_merge_internal: merge src into dest. |
| 852 | * Does NOT check bitmap permissions; not suitable for use as public API. |
| 853 | * @dest, @src and @backup (if not NULL) must have same size. |
| 854 | * |
| 855 | * @backup: If provided, make a copy of dest here prior to merge. |
| 856 | * @lock: If true, lock and unlock bitmaps on the way in/out. |
| 857 | */ |
| 858 | void bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest, |
| 859 | const BdrvDirtyBitmap *src, |
| 860 | HBitmap **backup, |
| 861 | bool lock) |
| 862 | { |
| 863 | IO_CODE(); |
| 864 | |
| 865 | assert(!bdrv_dirty_bitmap_readonly(dest)); |
| 866 | assert(!bdrv_dirty_bitmap_inconsistent(dest)); |
| 867 | assert(!bdrv_dirty_bitmap_inconsistent(src)); |
| 868 | |
| 869 | if (lock) { |
| 870 | bdrv_dirty_bitmaps_lock(dest->bs); |
| 871 | if (src->bs != dest->bs) { |
| 872 | bdrv_dirty_bitmaps_lock(src->bs); |
| 873 | } |
| 874 | } |
| 875 | |
| 876 | if (backup) { |
| 877 | *backup = dest->bitmap; |
| 878 | dest->bitmap = hbitmap_alloc(dest->size, hbitmap_granularity(*backup)); |
| 879 | hbitmap_merge(*backup, src->bitmap, dest->bitmap); |
| 880 | } else { |
| 881 | hbitmap_merge(dest->bitmap, src->bitmap, dest->bitmap); |
| 882 | } |
| 883 | |
| 884 | if (lock) { |
| 885 | bdrv_dirty_bitmaps_unlock(dest->bs); |
| 886 | if (src->bs != dest->bs) { |
| 887 | bdrv_dirty_bitmaps_unlock(src->bs); |
| 888 | } |
| 889 | } |
| 890 | } |