1 /* 2 * Block driver for the QCOW version 2 format 3 * 4 * Copyright (c) 2004-2006 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 27 #include "block/qdict.h" 28 #include "sysemu/block-backend.h" 29 #include "qemu/main-loop.h" 30 #include "qemu/module.h" 31 #include "qcow2.h" 32 #include "qemu/error-report.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-events-block-core.h" 35 #include "qapi/qmp/qdict.h" 36 #include "qapi/qmp/qstring.h" 37 #include "trace.h" 38 #include "qemu/option_int.h" 39 #include "qemu/cutils.h" 40 #include "qemu/bswap.h" 41 #include "qemu/memalign.h" 42 #include "qapi/qobject-input-visitor.h" 43 #include "qapi/qapi-visit-block-core.h" 44 #include "crypto.h" 45 #include "block/aio_task.h" 46 #include "block/dirty-bitmap.h" 47 48 /* 49 Differences with QCOW: 50 51 - Support for multiple incremental snapshots. 52 - Memory management by reference counts. 53 - Clusters which have a reference count of one have the bit 54 QCOW_OFLAG_COPIED to optimize write performance. 55 - Size of compressed clusters is stored in sectors to reduce bit usage 56 in the cluster offsets. 57 - Support for storing additional data (such as the VM state) in the 58 snapshots. 59 - If a backing store is used, the cluster size is not constrained 60 (could be backported to QCOW). 61 - L2 tables have always a size of one cluster. 62 */ 63 64 65 typedef struct { 66 uint32_t magic; 67 uint32_t len; 68 } QEMU_PACKED QCowExtension; 69 70 #define QCOW2_EXT_MAGIC_END 0 71 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca 72 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 73 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 74 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 75 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 76 77 static int coroutine_fn 78 qcow2_co_preadv_compressed(BlockDriverState *bs, 79 uint64_t l2_entry, 80 uint64_t offset, 81 uint64_t bytes, 82 QEMUIOVector *qiov, 83 size_t qiov_offset); 84 85 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) 86 { 87 const QCowHeader *cow_header = (const void *)buf; 88 89 if (buf_size >= sizeof(QCowHeader) && 90 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 91 be32_to_cpu(cow_header->version) >= 2) 92 return 100; 93 else 94 return 0; 95 } 96 97 98 static int GRAPH_RDLOCK 99 qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, 100 uint8_t *buf, size_t buflen, 101 void *opaque, Error **errp) 102 { 103 BlockDriverState *bs = opaque; 104 BDRVQcow2State *s = bs->opaque; 105 ssize_t ret; 106 107 if ((offset + buflen) > s->crypto_header.length) { 108 error_setg(errp, "Request for data outside of extension header"); 109 return -1; 110 } 111 112 ret = bdrv_pread(bs->file, s->crypto_header.offset + offset, buflen, buf, 113 0); 114 if (ret < 0) { 115 error_setg_errno(errp, -ret, "Could not read encryption header"); 116 return -1; 117 } 118 return 0; 119 } 120 121 122 static int coroutine_fn GRAPH_RDLOCK 123 qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, void *opaque, 124 Error **errp) 125 { 126 BlockDriverState *bs = opaque; 127 BDRVQcow2State *s = bs->opaque; 128 int64_t ret; 129 int64_t clusterlen; 130 131 ret = qcow2_alloc_clusters(bs, headerlen); 132 if (ret < 0) { 133 error_setg_errno(errp, -ret, 134 "Cannot allocate cluster for LUKS header size %zu", 135 headerlen); 136 return -1; 137 } 138 139 s->crypto_header.length = headerlen; 140 s->crypto_header.offset = ret; 141 142 /* 143 * Zero fill all space in cluster so it has predictable 144 * content, as we may not initialize some regions of the 145 * header (eg only 1 out of 8 key slots will be initialized) 146 */ 147 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; 148 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); 149 ret = bdrv_co_pwrite_zeroes(bs->file, ret, clusterlen, 0); 150 if (ret < 0) { 151 error_setg_errno(errp, -ret, "Could not zero fill encryption header"); 152 return -1; 153 } 154 155 return 0; 156 } 157 158 159 /* The graph lock must be held when called in coroutine context */ 160 static int coroutine_mixed_fn GRAPH_RDLOCK 161 qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, 162 const uint8_t *buf, size_t buflen, 163 void *opaque, Error **errp) 164 { 165 BlockDriverState *bs = opaque; 166 BDRVQcow2State *s = bs->opaque; 167 ssize_t ret; 168 169 if ((offset + buflen) > s->crypto_header.length) { 170 error_setg(errp, "Request for data outside of extension header"); 171 return -1; 172 } 173 174 ret = bdrv_pwrite(bs->file, s->crypto_header.offset + offset, buflen, buf, 175 0); 176 if (ret < 0) { 177 error_setg_errno(errp, -ret, "Could not read encryption header"); 178 return -1; 179 } 180 return 0; 181 } 182 183 static QDict* 184 qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp) 185 { 186 QDict *cryptoopts_qdict; 187 QDict *opts_qdict; 188 189 /* Extract "encrypt." options into a qdict */ 190 opts_qdict = qemu_opts_to_qdict(opts, NULL); 191 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); 192 qobject_unref(opts_qdict); 193 qdict_put_str(cryptoopts_qdict, "format", fmt); 194 return cryptoopts_qdict; 195 } 196 197 /* 198 * read qcow2 extension and fill bs 199 * start reading from start_offset 200 * finish reading upon magic of value 0 or when end_offset reached 201 * unknown magic is skipped (future extension this version knows nothing about) 202 * return 0 upon success, non-0 otherwise 203 */ 204 static int coroutine_fn GRAPH_RDLOCK 205 qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, 206 uint64_t end_offset, void **p_feature_table, 207 int flags, bool *need_update_header, Error **errp) 208 { 209 BDRVQcow2State *s = bs->opaque; 210 QCowExtension ext; 211 uint64_t offset; 212 int ret; 213 Qcow2BitmapHeaderExt bitmaps_ext; 214 215 if (need_update_header != NULL) { 216 *need_update_header = false; 217 } 218 219 #ifdef DEBUG_EXT 220 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); 221 #endif 222 offset = start_offset; 223 while (offset < end_offset) { 224 225 #ifdef DEBUG_EXT 226 /* Sanity check */ 227 if (offset > s->cluster_size) 228 printf("qcow2_read_extension: suspicious offset %lu\n", offset); 229 230 printf("attempting to read extended header in offset %lu\n", offset); 231 #endif 232 233 ret = bdrv_co_pread(bs->file, offset, sizeof(ext), &ext, 0); 234 if (ret < 0) { 235 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " 236 "pread fail from offset %" PRIu64, offset); 237 return 1; 238 } 239 ext.magic = be32_to_cpu(ext.magic); 240 ext.len = be32_to_cpu(ext.len); 241 offset += sizeof(ext); 242 #ifdef DEBUG_EXT 243 printf("ext.magic = 0x%x\n", ext.magic); 244 #endif 245 if (offset > end_offset || ext.len > end_offset - offset) { 246 error_setg(errp, "Header extension too large"); 247 return -EINVAL; 248 } 249 250 switch (ext.magic) { 251 case QCOW2_EXT_MAGIC_END: 252 return 0; 253 254 case QCOW2_EXT_MAGIC_BACKING_FORMAT: 255 if (ext.len >= sizeof(bs->backing_format)) { 256 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 257 " too large (>=%zu)", ext.len, 258 sizeof(bs->backing_format)); 259 return 2; 260 } 261 ret = bdrv_co_pread(bs->file, offset, ext.len, bs->backing_format, 0); 262 if (ret < 0) { 263 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " 264 "Could not read format name"); 265 return 3; 266 } 267 bs->backing_format[ext.len] = '\0'; 268 s->image_backing_format = g_strdup(bs->backing_format); 269 #ifdef DEBUG_EXT 270 printf("Qcow2: Got format extension %s\n", bs->backing_format); 271 #endif 272 break; 273 274 case QCOW2_EXT_MAGIC_FEATURE_TABLE: 275 if (p_feature_table != NULL) { 276 void *feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); 277 ret = bdrv_co_pread(bs->file, offset, ext.len, feature_table, 0); 278 if (ret < 0) { 279 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " 280 "Could not read table"); 281 g_free(feature_table); 282 return ret; 283 } 284 285 *p_feature_table = feature_table; 286 } 287 break; 288 289 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { 290 unsigned int cflags = 0; 291 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 292 error_setg(errp, "CRYPTO header extension only " 293 "expected with LUKS encryption method"); 294 return -EINVAL; 295 } 296 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { 297 error_setg(errp, "CRYPTO header extension size %u, " 298 "but expected size %zu", ext.len, 299 sizeof(Qcow2CryptoHeaderExtension)); 300 return -EINVAL; 301 } 302 303 ret = bdrv_co_pread(bs->file, offset, ext.len, &s->crypto_header, 0); 304 if (ret < 0) { 305 error_setg_errno(errp, -ret, 306 "Unable to read CRYPTO header extension"); 307 return ret; 308 } 309 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 310 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 311 312 if ((s->crypto_header.offset % s->cluster_size) != 0) { 313 error_setg(errp, "Encryption header offset '%" PRIu64 "' is " 314 "not a multiple of cluster size '%u'", 315 s->crypto_header.offset, s->cluster_size); 316 return -EINVAL; 317 } 318 319 if (flags & BDRV_O_NO_IO) { 320 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 321 } 322 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 323 qcow2_crypto_hdr_read_func, 324 bs, cflags, errp); 325 if (!s->crypto) { 326 return -EINVAL; 327 } 328 } break; 329 330 case QCOW2_EXT_MAGIC_BITMAPS: 331 if (ext.len != sizeof(bitmaps_ext)) { 332 error_setg_errno(errp, -ret, "bitmaps_ext: " 333 "Invalid extension length"); 334 return -EINVAL; 335 } 336 337 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { 338 if (s->qcow_version < 3) { 339 /* Let's be a bit more specific */ 340 warn_report("This qcow2 v2 image contains bitmaps, but " 341 "they may have been modified by a program " 342 "without persistent bitmap support; so now " 343 "they must all be considered inconsistent"); 344 } else { 345 warn_report("a program lacking bitmap support " 346 "modified this file, so all bitmaps are now " 347 "considered inconsistent"); 348 } 349 error_printf("Some clusters may be leaked, " 350 "run 'qemu-img check -r' on the image " 351 "file to fix."); 352 if (need_update_header != NULL) { 353 /* Updating is needed to drop invalid bitmap extension. */ 354 *need_update_header = true; 355 } 356 break; 357 } 358 359 ret = bdrv_co_pread(bs->file, offset, ext.len, &bitmaps_ext, 0); 360 if (ret < 0) { 361 error_setg_errno(errp, -ret, "bitmaps_ext: " 362 "Could not read ext header"); 363 return ret; 364 } 365 366 if (bitmaps_ext.reserved32 != 0) { 367 error_setg_errno(errp, -ret, "bitmaps_ext: " 368 "Reserved field is not zero"); 369 return -EINVAL; 370 } 371 372 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); 373 bitmaps_ext.bitmap_directory_size = 374 be64_to_cpu(bitmaps_ext.bitmap_directory_size); 375 bitmaps_ext.bitmap_directory_offset = 376 be64_to_cpu(bitmaps_ext.bitmap_directory_offset); 377 378 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { 379 error_setg(errp, 380 "bitmaps_ext: Image has %" PRIu32 " bitmaps, " 381 "exceeding the QEMU supported maximum of %d", 382 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); 383 return -EINVAL; 384 } 385 386 if (bitmaps_ext.nb_bitmaps == 0) { 387 error_setg(errp, "found bitmaps extension with zero bitmaps"); 388 return -EINVAL; 389 } 390 391 if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) { 392 error_setg(errp, "bitmaps_ext: " 393 "invalid bitmap directory offset"); 394 return -EINVAL; 395 } 396 397 if (bitmaps_ext.bitmap_directory_size > 398 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { 399 error_setg(errp, "bitmaps_ext: " 400 "bitmap directory size (%" PRIu64 ") exceeds " 401 "the maximum supported size (%d)", 402 bitmaps_ext.bitmap_directory_size, 403 QCOW2_MAX_BITMAP_DIRECTORY_SIZE); 404 return -EINVAL; 405 } 406 407 s->nb_bitmaps = bitmaps_ext.nb_bitmaps; 408 s->bitmap_directory_offset = 409 bitmaps_ext.bitmap_directory_offset; 410 s->bitmap_directory_size = 411 bitmaps_ext.bitmap_directory_size; 412 413 #ifdef DEBUG_EXT 414 printf("Qcow2: Got bitmaps extension: " 415 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", 416 s->bitmap_directory_offset, s->nb_bitmaps); 417 #endif 418 break; 419 420 case QCOW2_EXT_MAGIC_DATA_FILE: 421 { 422 s->image_data_file = g_malloc0(ext.len + 1); 423 ret = bdrv_co_pread(bs->file, offset, ext.len, s->image_data_file, 0); 424 if (ret < 0) { 425 error_setg_errno(errp, -ret, 426 "ERROR: Could not read data file name"); 427 return ret; 428 } 429 #ifdef DEBUG_EXT 430 printf("Qcow2: Got external data file %s\n", s->image_data_file); 431 #endif 432 break; 433 } 434 435 default: 436 /* unknown magic - save it in case we need to rewrite the header */ 437 /* If you add a new feature, make sure to also update the fast 438 * path of qcow2_make_empty() to deal with it. */ 439 { 440 Qcow2UnknownHeaderExtension *uext; 441 442 uext = g_malloc0(sizeof(*uext) + ext.len); 443 uext->magic = ext.magic; 444 uext->len = ext.len; 445 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); 446 447 ret = bdrv_co_pread(bs->file, offset, uext->len, uext->data, 0); 448 if (ret < 0) { 449 error_setg_errno(errp, -ret, "ERROR: unknown extension: " 450 "Could not read data"); 451 return ret; 452 } 453 } 454 break; 455 } 456 457 offset += ((ext.len + 7) & ~7); 458 } 459 460 return 0; 461 } 462 463 static void cleanup_unknown_header_ext(BlockDriverState *bs) 464 { 465 BDRVQcow2State *s = bs->opaque; 466 Qcow2UnknownHeaderExtension *uext, *next; 467 468 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { 469 QLIST_REMOVE(uext, next); 470 g_free(uext); 471 } 472 } 473 474 static void report_unsupported_feature(Error **errp, Qcow2Feature *table, 475 uint64_t mask) 476 { 477 g_autoptr(GString) features = g_string_sized_new(60); 478 479 while (table && table->name[0] != '\0') { 480 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { 481 if (mask & (1ULL << table->bit)) { 482 if (features->len > 0) { 483 g_string_append(features, ", "); 484 } 485 g_string_append_printf(features, "%.46s", table->name); 486 mask &= ~(1ULL << table->bit); 487 } 488 } 489 table++; 490 } 491 492 if (mask) { 493 if (features->len > 0) { 494 g_string_append(features, ", "); 495 } 496 g_string_append_printf(features, 497 "Unknown incompatible feature: %" PRIx64, mask); 498 } 499 500 error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); 501 } 502 503 /* 504 * Sets the dirty bit and flushes afterwards if necessary. 505 * 506 * The incompatible_features bit is only set if the image file header was 507 * updated successfully. Therefore it is not required to check the return 508 * value of this function. 509 */ 510 int qcow2_mark_dirty(BlockDriverState *bs) 511 { 512 BDRVQcow2State *s = bs->opaque; 513 uint64_t val; 514 int ret; 515 516 assert(s->qcow_version >= 3); 517 518 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 519 return 0; /* already dirty */ 520 } 521 522 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); 523 ret = bdrv_pwrite_sync(bs->file, 524 offsetof(QCowHeader, incompatible_features), 525 sizeof(val), &val, 0); 526 if (ret < 0) { 527 return ret; 528 } 529 530 /* Only treat image as dirty if the header was updated successfully */ 531 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; 532 return 0; 533 } 534 535 /* 536 * Clears the dirty bit and flushes before if necessary. Only call this 537 * function when there are no pending requests, it does not guard against 538 * concurrent requests dirtying the image. 539 */ 540 static int GRAPH_RDLOCK qcow2_mark_clean(BlockDriverState *bs) 541 { 542 BDRVQcow2State *s = bs->opaque; 543 544 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 545 int ret; 546 547 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; 548 549 ret = qcow2_flush_caches(bs); 550 if (ret < 0) { 551 return ret; 552 } 553 554 return qcow2_update_header(bs); 555 } 556 return 0; 557 } 558 559 /* 560 * Marks the image as corrupt. 561 */ 562 int qcow2_mark_corrupt(BlockDriverState *bs) 563 { 564 BDRVQcow2State *s = bs->opaque; 565 566 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; 567 return qcow2_update_header(bs); 568 } 569 570 /* 571 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes 572 * before if necessary. 573 */ 574 static int coroutine_fn GRAPH_RDLOCK 575 qcow2_mark_consistent(BlockDriverState *bs) 576 { 577 BDRVQcow2State *s = bs->opaque; 578 579 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 580 int ret = qcow2_flush_caches(bs); 581 if (ret < 0) { 582 return ret; 583 } 584 585 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; 586 return qcow2_update_header(bs); 587 } 588 return 0; 589 } 590 591 static void qcow2_add_check_result(BdrvCheckResult *out, 592 const BdrvCheckResult *src, 593 bool set_allocation_info) 594 { 595 out->corruptions += src->corruptions; 596 out->leaks += src->leaks; 597 out->check_errors += src->check_errors; 598 out->corruptions_fixed += src->corruptions_fixed; 599 out->leaks_fixed += src->leaks_fixed; 600 601 if (set_allocation_info) { 602 out->image_end_offset = src->image_end_offset; 603 out->bfi = src->bfi; 604 } 605 } 606 607 static int coroutine_fn GRAPH_RDLOCK 608 qcow2_co_check_locked(BlockDriverState *bs, BdrvCheckResult *result, 609 BdrvCheckMode fix) 610 { 611 BdrvCheckResult snapshot_res = {}; 612 BdrvCheckResult refcount_res = {}; 613 int ret; 614 615 memset(result, 0, sizeof(*result)); 616 617 ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix); 618 if (ret < 0) { 619 qcow2_add_check_result(result, &snapshot_res, false); 620 return ret; 621 } 622 623 ret = qcow2_check_refcounts(bs, &refcount_res, fix); 624 qcow2_add_check_result(result, &refcount_res, true); 625 if (ret < 0) { 626 qcow2_add_check_result(result, &snapshot_res, false); 627 return ret; 628 } 629 630 ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix); 631 qcow2_add_check_result(result, &snapshot_res, false); 632 if (ret < 0) { 633 return ret; 634 } 635 636 if (fix && result->check_errors == 0 && result->corruptions == 0) { 637 ret = qcow2_mark_clean(bs); 638 if (ret < 0) { 639 return ret; 640 } 641 return qcow2_mark_consistent(bs); 642 } 643 return ret; 644 } 645 646 static int coroutine_fn GRAPH_RDLOCK 647 qcow2_co_check(BlockDriverState *bs, BdrvCheckResult *result, 648 BdrvCheckMode fix) 649 { 650 BDRVQcow2State *s = bs->opaque; 651 int ret; 652 653 qemu_co_mutex_lock(&s->lock); 654 ret = qcow2_co_check_locked(bs, result, fix); 655 qemu_co_mutex_unlock(&s->lock); 656 return ret; 657 } 658 659 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 660 uint64_t entries, size_t entry_len, 661 int64_t max_size_bytes, const char *table_name, 662 Error **errp) 663 { 664 BDRVQcow2State *s = bs->opaque; 665 666 if (entries > max_size_bytes / entry_len) { 667 error_setg(errp, "%s too large", table_name); 668 return -EFBIG; 669 } 670 671 /* Use signed INT64_MAX as the maximum even for uint64_t header fields, 672 * because values will be passed to qemu functions taking int64_t. */ 673 if ((INT64_MAX - entries * entry_len < offset) || 674 (offset_into_cluster(s, offset) != 0)) { 675 error_setg(errp, "%s offset invalid", table_name); 676 return -EINVAL; 677 } 678 679 return 0; 680 } 681 682 static const char *const mutable_opts[] = { 683 QCOW2_OPT_LAZY_REFCOUNTS, 684 QCOW2_OPT_DISCARD_REQUEST, 685 QCOW2_OPT_DISCARD_SNAPSHOT, 686 QCOW2_OPT_DISCARD_OTHER, 687 QCOW2_OPT_DISCARD_NO_UNREF, 688 QCOW2_OPT_OVERLAP, 689 QCOW2_OPT_OVERLAP_TEMPLATE, 690 QCOW2_OPT_OVERLAP_MAIN_HEADER, 691 QCOW2_OPT_OVERLAP_ACTIVE_L1, 692 QCOW2_OPT_OVERLAP_ACTIVE_L2, 693 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 694 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 695 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 696 QCOW2_OPT_OVERLAP_INACTIVE_L1, 697 QCOW2_OPT_OVERLAP_INACTIVE_L2, 698 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 699 QCOW2_OPT_CACHE_SIZE, 700 QCOW2_OPT_L2_CACHE_SIZE, 701 QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 702 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 703 QCOW2_OPT_CACHE_CLEAN_INTERVAL, 704 NULL 705 }; 706 707 static QemuOptsList qcow2_runtime_opts = { 708 .name = "qcow2", 709 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), 710 .desc = { 711 { 712 .name = QCOW2_OPT_LAZY_REFCOUNTS, 713 .type = QEMU_OPT_BOOL, 714 .help = "Postpone refcount updates", 715 }, 716 { 717 .name = QCOW2_OPT_DISCARD_REQUEST, 718 .type = QEMU_OPT_BOOL, 719 .help = "Pass guest discard requests to the layer below", 720 }, 721 { 722 .name = QCOW2_OPT_DISCARD_SNAPSHOT, 723 .type = QEMU_OPT_BOOL, 724 .help = "Generate discard requests when snapshot related space " 725 "is freed", 726 }, 727 { 728 .name = QCOW2_OPT_DISCARD_OTHER, 729 .type = QEMU_OPT_BOOL, 730 .help = "Generate discard requests when other clusters are freed", 731 }, 732 { 733 .name = QCOW2_OPT_DISCARD_NO_UNREF, 734 .type = QEMU_OPT_BOOL, 735 .help = "Do not unreference discarded clusters", 736 }, 737 { 738 .name = QCOW2_OPT_OVERLAP, 739 .type = QEMU_OPT_STRING, 740 .help = "Selects which overlap checks to perform from a range of " 741 "templates (none, constant, cached, all)", 742 }, 743 { 744 .name = QCOW2_OPT_OVERLAP_TEMPLATE, 745 .type = QEMU_OPT_STRING, 746 .help = "Selects which overlap checks to perform from a range of " 747 "templates (none, constant, cached, all)", 748 }, 749 { 750 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, 751 .type = QEMU_OPT_BOOL, 752 .help = "Check for unintended writes into the main qcow2 header", 753 }, 754 { 755 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, 756 .type = QEMU_OPT_BOOL, 757 .help = "Check for unintended writes into the active L1 table", 758 }, 759 { 760 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, 761 .type = QEMU_OPT_BOOL, 762 .help = "Check for unintended writes into an active L2 table", 763 }, 764 { 765 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 766 .type = QEMU_OPT_BOOL, 767 .help = "Check for unintended writes into the refcount table", 768 }, 769 { 770 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 771 .type = QEMU_OPT_BOOL, 772 .help = "Check for unintended writes into a refcount block", 773 }, 774 { 775 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 776 .type = QEMU_OPT_BOOL, 777 .help = "Check for unintended writes into the snapshot table", 778 }, 779 { 780 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, 781 .type = QEMU_OPT_BOOL, 782 .help = "Check for unintended writes into an inactive L1 table", 783 }, 784 { 785 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, 786 .type = QEMU_OPT_BOOL, 787 .help = "Check for unintended writes into an inactive L2 table", 788 }, 789 { 790 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 791 .type = QEMU_OPT_BOOL, 792 .help = "Check for unintended writes into the bitmap directory", 793 }, 794 { 795 .name = QCOW2_OPT_CACHE_SIZE, 796 .type = QEMU_OPT_SIZE, 797 .help = "Maximum combined metadata (L2 tables and refcount blocks) " 798 "cache size", 799 }, 800 { 801 .name = QCOW2_OPT_L2_CACHE_SIZE, 802 .type = QEMU_OPT_SIZE, 803 .help = "Maximum L2 table cache size", 804 }, 805 { 806 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 807 .type = QEMU_OPT_SIZE, 808 .help = "Size of each entry in the L2 cache", 809 }, 810 { 811 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, 812 .type = QEMU_OPT_SIZE, 813 .help = "Maximum refcount block cache size", 814 }, 815 { 816 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, 817 .type = QEMU_OPT_NUMBER, 818 .help = "Clean unused cache entries after this time (in seconds)", 819 }, 820 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 821 "ID of secret providing qcow2 AES key or LUKS passphrase"), 822 { /* end of list */ } 823 }, 824 }; 825 826 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { 827 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, 828 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, 829 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, 830 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 831 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 832 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 833 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, 834 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, 835 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 836 }; 837 838 static void cache_clean_timer_cb(void *opaque) 839 { 840 BlockDriverState *bs = opaque; 841 BDRVQcow2State *s = bs->opaque; 842 qcow2_cache_clean_unused(s->l2_table_cache); 843 qcow2_cache_clean_unused(s->refcount_block_cache); 844 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 845 (int64_t) s->cache_clean_interval * 1000); 846 } 847 848 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) 849 { 850 BDRVQcow2State *s = bs->opaque; 851 if (s->cache_clean_interval > 0) { 852 s->cache_clean_timer = 853 aio_timer_new_with_attrs(context, QEMU_CLOCK_VIRTUAL, 854 SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL, 855 cache_clean_timer_cb, bs); 856 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 857 (int64_t) s->cache_clean_interval * 1000); 858 } 859 } 860 861 static void cache_clean_timer_del(BlockDriverState *bs) 862 { 863 BDRVQcow2State *s = bs->opaque; 864 if (s->cache_clean_timer) { 865 timer_free(s->cache_clean_timer); 866 s->cache_clean_timer = NULL; 867 } 868 } 869 870 static void qcow2_detach_aio_context(BlockDriverState *bs) 871 { 872 cache_clean_timer_del(bs); 873 } 874 875 static void qcow2_attach_aio_context(BlockDriverState *bs, 876 AioContext *new_context) 877 { 878 cache_clean_timer_init(bs, new_context); 879 } 880 881 static bool read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, 882 uint64_t *l2_cache_size, 883 uint64_t *l2_cache_entry_size, 884 uint64_t *refcount_cache_size, Error **errp) 885 { 886 BDRVQcow2State *s = bs->opaque; 887 uint64_t combined_cache_size, l2_cache_max_setting; 888 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; 889 bool l2_cache_entry_size_set; 890 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; 891 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; 892 uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); 893 /* An L2 table is always one cluster in size so the max cache size 894 * should be a multiple of the cluster size. */ 895 uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s), 896 s->cluster_size); 897 898 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); 899 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); 900 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 901 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); 902 903 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); 904 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 905 DEFAULT_L2_CACHE_MAX_SIZE); 906 *refcount_cache_size = qemu_opt_get_size(opts, 907 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); 908 909 *l2_cache_entry_size = qemu_opt_get_size( 910 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); 911 912 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); 913 914 if (combined_cache_size_set) { 915 if (l2_cache_size_set && refcount_cache_size_set) { 916 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE 917 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " 918 "at the same time"); 919 return false; 920 } else if (l2_cache_size_set && 921 (l2_cache_max_setting > combined_cache_size)) { 922 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " 923 QCOW2_OPT_CACHE_SIZE); 924 return false; 925 } else if (*refcount_cache_size > combined_cache_size) { 926 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " 927 QCOW2_OPT_CACHE_SIZE); 928 return false; 929 } 930 931 if (l2_cache_size_set) { 932 *refcount_cache_size = combined_cache_size - *l2_cache_size; 933 } else if (refcount_cache_size_set) { 934 *l2_cache_size = combined_cache_size - *refcount_cache_size; 935 } else { 936 /* Assign as much memory as possible to the L2 cache, and 937 * use the remainder for the refcount cache */ 938 if (combined_cache_size >= max_l2_cache + min_refcount_cache) { 939 *l2_cache_size = max_l2_cache; 940 *refcount_cache_size = combined_cache_size - *l2_cache_size; 941 } else { 942 *refcount_cache_size = 943 MIN(combined_cache_size, min_refcount_cache); 944 *l2_cache_size = combined_cache_size - *refcount_cache_size; 945 } 946 } 947 } 948 949 /* 950 * If the L2 cache is not enough to cover the whole disk then 951 * default to 4KB entries. Smaller entries reduce the cost of 952 * loads and evictions and increase I/O performance. 953 */ 954 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { 955 *l2_cache_entry_size = MIN(s->cluster_size, 4096); 956 } 957 958 /* l2_cache_size and refcount_cache_size are ensured to have at least 959 * their minimum values in qcow2_update_options_prepare() */ 960 961 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || 962 *l2_cache_entry_size > s->cluster_size || 963 !is_power_of_2(*l2_cache_entry_size)) { 964 error_setg(errp, "L2 cache entry size must be a power of two " 965 "between %d and the cluster size (%d)", 966 1 << MIN_CLUSTER_BITS, s->cluster_size); 967 return false; 968 } 969 970 return true; 971 } 972 973 typedef struct Qcow2ReopenState { 974 Qcow2Cache *l2_table_cache; 975 Qcow2Cache *refcount_block_cache; 976 int l2_slice_size; /* Number of entries in a slice of the L2 table */ 977 bool use_lazy_refcounts; 978 int overlap_check; 979 bool discard_passthrough[QCOW2_DISCARD_MAX]; 980 bool discard_no_unref; 981 uint64_t cache_clean_interval; 982 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 983 } Qcow2ReopenState; 984 985 static int GRAPH_RDLOCK 986 qcow2_update_options_prepare(BlockDriverState *bs, Qcow2ReopenState *r, 987 QDict *options, int flags, Error **errp) 988 { 989 BDRVQcow2State *s = bs->opaque; 990 QemuOpts *opts = NULL; 991 const char *opt_overlap_check, *opt_overlap_check_template; 992 int overlap_check_template = 0; 993 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; 994 int i; 995 const char *encryptfmt; 996 QDict *encryptopts = NULL; 997 int ret; 998 999 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 1000 encryptfmt = qdict_get_try_str(encryptopts, "format"); 1001 1002 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); 1003 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1004 ret = -EINVAL; 1005 goto fail; 1006 } 1007 1008 /* get L2 table/refcount block cache size from command line options */ 1009 if (!read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, 1010 &refcount_cache_size, errp)) { 1011 ret = -EINVAL; 1012 goto fail; 1013 } 1014 1015 l2_cache_size /= l2_cache_entry_size; 1016 if (l2_cache_size < MIN_L2_CACHE_SIZE) { 1017 l2_cache_size = MIN_L2_CACHE_SIZE; 1018 } 1019 if (l2_cache_size > INT_MAX) { 1020 error_setg(errp, "L2 cache size too big"); 1021 ret = -EINVAL; 1022 goto fail; 1023 } 1024 1025 refcount_cache_size /= s->cluster_size; 1026 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { 1027 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; 1028 } 1029 if (refcount_cache_size > INT_MAX) { 1030 error_setg(errp, "Refcount cache size too big"); 1031 ret = -EINVAL; 1032 goto fail; 1033 } 1034 1035 /* alloc new L2 table/refcount block cache, flush old one */ 1036 if (s->l2_table_cache) { 1037 ret = qcow2_cache_flush(bs, s->l2_table_cache); 1038 if (ret) { 1039 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); 1040 goto fail; 1041 } 1042 } 1043 1044 if (s->refcount_block_cache) { 1045 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 1046 if (ret) { 1047 error_setg_errno(errp, -ret, 1048 "Failed to flush the refcount block cache"); 1049 goto fail; 1050 } 1051 } 1052 1053 r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s); 1054 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, 1055 l2_cache_entry_size); 1056 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, 1057 s->cluster_size); 1058 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { 1059 error_setg(errp, "Could not allocate metadata caches"); 1060 ret = -ENOMEM; 1061 goto fail; 1062 } 1063 1064 /* New interval for cache cleanup timer */ 1065 r->cache_clean_interval = 1066 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 1067 DEFAULT_CACHE_CLEAN_INTERVAL); 1068 #ifndef CONFIG_LINUX 1069 if (r->cache_clean_interval != 0) { 1070 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL 1071 " not supported on this host"); 1072 ret = -EINVAL; 1073 goto fail; 1074 } 1075 #endif 1076 if (r->cache_clean_interval > UINT_MAX) { 1077 error_setg(errp, "Cache clean interval too big"); 1078 ret = -EINVAL; 1079 goto fail; 1080 } 1081 1082 /* lazy-refcounts; flush if going from enabled to disabled */ 1083 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, 1084 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); 1085 if (r->use_lazy_refcounts && s->qcow_version < 3) { 1086 error_setg(errp, "Lazy refcounts require a qcow2 image with at least " 1087 "qemu 1.1 compatibility level"); 1088 ret = -EINVAL; 1089 goto fail; 1090 } 1091 1092 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { 1093 ret = qcow2_mark_clean(bs); 1094 if (ret < 0) { 1095 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); 1096 goto fail; 1097 } 1098 } 1099 1100 /* Overlap check options */ 1101 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); 1102 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); 1103 if (opt_overlap_check_template && opt_overlap_check && 1104 strcmp(opt_overlap_check_template, opt_overlap_check)) 1105 { 1106 error_setg(errp, "Conflicting values for qcow2 options '" 1107 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE 1108 "' ('%s')", opt_overlap_check, opt_overlap_check_template); 1109 ret = -EINVAL; 1110 goto fail; 1111 } 1112 if (!opt_overlap_check) { 1113 opt_overlap_check = opt_overlap_check_template ?: "cached"; 1114 } 1115 1116 if (!strcmp(opt_overlap_check, "none")) { 1117 overlap_check_template = 0; 1118 } else if (!strcmp(opt_overlap_check, "constant")) { 1119 overlap_check_template = QCOW2_OL_CONSTANT; 1120 } else if (!strcmp(opt_overlap_check, "cached")) { 1121 overlap_check_template = QCOW2_OL_CACHED; 1122 } else if (!strcmp(opt_overlap_check, "all")) { 1123 overlap_check_template = QCOW2_OL_ALL; 1124 } else { 1125 error_setg(errp, "Unsupported value '%s' for qcow2 option " 1126 "'overlap-check'. Allowed are any of the following: " 1127 "none, constant, cached, all", opt_overlap_check); 1128 ret = -EINVAL; 1129 goto fail; 1130 } 1131 1132 r->overlap_check = 0; 1133 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { 1134 /* overlap-check defines a template bitmask, but every flag may be 1135 * overwritten through the associated boolean option */ 1136 r->overlap_check |= 1137 qemu_opt_get_bool(opts, overlap_bool_option_names[i], 1138 overlap_check_template & (1 << i)) << i; 1139 } 1140 1141 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; 1142 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; 1143 r->discard_passthrough[QCOW2_DISCARD_REQUEST] = 1144 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, 1145 flags & BDRV_O_UNMAP); 1146 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = 1147 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); 1148 r->discard_passthrough[QCOW2_DISCARD_OTHER] = 1149 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); 1150 1151 r->discard_no_unref = qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_NO_UNREF, 1152 false); 1153 if (r->discard_no_unref && s->qcow_version < 3) { 1154 error_setg(errp, 1155 "discard-no-unref is only supported since qcow2 version 3"); 1156 ret = -EINVAL; 1157 goto fail; 1158 } 1159 1160 switch (s->crypt_method_header) { 1161 case QCOW_CRYPT_NONE: 1162 if (encryptfmt) { 1163 error_setg(errp, "No encryption in image header, but options " 1164 "specified format '%s'", encryptfmt); 1165 ret = -EINVAL; 1166 goto fail; 1167 } 1168 break; 1169 1170 case QCOW_CRYPT_AES: 1171 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 1172 error_setg(errp, 1173 "Header reported 'aes' encryption format but " 1174 "options specify '%s'", encryptfmt); 1175 ret = -EINVAL; 1176 goto fail; 1177 } 1178 qdict_put_str(encryptopts, "format", "qcow"); 1179 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1180 if (!r->crypto_opts) { 1181 ret = -EINVAL; 1182 goto fail; 1183 } 1184 break; 1185 1186 case QCOW_CRYPT_LUKS: 1187 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { 1188 error_setg(errp, 1189 "Header reported 'luks' encryption format but " 1190 "options specify '%s'", encryptfmt); 1191 ret = -EINVAL; 1192 goto fail; 1193 } 1194 qdict_put_str(encryptopts, "format", "luks"); 1195 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1196 if (!r->crypto_opts) { 1197 ret = -EINVAL; 1198 goto fail; 1199 } 1200 break; 1201 1202 default: 1203 error_setg(errp, "Unsupported encryption method %d", 1204 s->crypt_method_header); 1205 ret = -EINVAL; 1206 goto fail; 1207 } 1208 1209 ret = 0; 1210 fail: 1211 qobject_unref(encryptopts); 1212 qemu_opts_del(opts); 1213 opts = NULL; 1214 return ret; 1215 } 1216 1217 static void qcow2_update_options_commit(BlockDriverState *bs, 1218 Qcow2ReopenState *r) 1219 { 1220 BDRVQcow2State *s = bs->opaque; 1221 int i; 1222 1223 if (s->l2_table_cache) { 1224 qcow2_cache_destroy(s->l2_table_cache); 1225 } 1226 if (s->refcount_block_cache) { 1227 qcow2_cache_destroy(s->refcount_block_cache); 1228 } 1229 s->l2_table_cache = r->l2_table_cache; 1230 s->refcount_block_cache = r->refcount_block_cache; 1231 s->l2_slice_size = r->l2_slice_size; 1232 1233 s->overlap_check = r->overlap_check; 1234 s->use_lazy_refcounts = r->use_lazy_refcounts; 1235 1236 for (i = 0; i < QCOW2_DISCARD_MAX; i++) { 1237 s->discard_passthrough[i] = r->discard_passthrough[i]; 1238 } 1239 1240 s->discard_no_unref = r->discard_no_unref; 1241 1242 if (s->cache_clean_interval != r->cache_clean_interval) { 1243 cache_clean_timer_del(bs); 1244 s->cache_clean_interval = r->cache_clean_interval; 1245 cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); 1246 } 1247 1248 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1249 s->crypto_opts = r->crypto_opts; 1250 } 1251 1252 static void qcow2_update_options_abort(BlockDriverState *bs, 1253 Qcow2ReopenState *r) 1254 { 1255 if (r->l2_table_cache) { 1256 qcow2_cache_destroy(r->l2_table_cache); 1257 } 1258 if (r->refcount_block_cache) { 1259 qcow2_cache_destroy(r->refcount_block_cache); 1260 } 1261 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); 1262 } 1263 1264 static int coroutine_fn GRAPH_RDLOCK 1265 qcow2_update_options(BlockDriverState *bs, QDict *options, int flags, 1266 Error **errp) 1267 { 1268 Qcow2ReopenState r = {}; 1269 int ret; 1270 1271 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); 1272 if (ret >= 0) { 1273 qcow2_update_options_commit(bs, &r); 1274 } else { 1275 qcow2_update_options_abort(bs, &r); 1276 } 1277 1278 return ret; 1279 } 1280 1281 static int validate_compression_type(BDRVQcow2State *s, Error **errp) 1282 { 1283 switch (s->compression_type) { 1284 case QCOW2_COMPRESSION_TYPE_ZLIB: 1285 #ifdef CONFIG_ZSTD 1286 case QCOW2_COMPRESSION_TYPE_ZSTD: 1287 #endif 1288 break; 1289 1290 default: 1291 error_setg(errp, "qcow2: unknown compression type: %u", 1292 s->compression_type); 1293 return -ENOTSUP; 1294 } 1295 1296 /* 1297 * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB 1298 * the incompatible feature flag must be set 1299 */ 1300 if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) { 1301 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 1302 error_setg(errp, "qcow2: Compression type incompatible feature " 1303 "bit must not be set"); 1304 return -EINVAL; 1305 } 1306 } else { 1307 if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) { 1308 error_setg(errp, "qcow2: Compression type incompatible feature " 1309 "bit must be set"); 1310 return -EINVAL; 1311 } 1312 } 1313 1314 return 0; 1315 } 1316 1317 /* Called with s->lock held. */ 1318 static int coroutine_fn GRAPH_RDLOCK 1319 qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, 1320 bool open_data_file, Error **errp) 1321 { 1322 ERRP_GUARD(); 1323 BDRVQcow2State *s = bs->opaque; 1324 unsigned int len, i; 1325 int ret = 0; 1326 QCowHeader header; 1327 uint64_t ext_end; 1328 uint64_t l1_vm_state_index; 1329 bool update_header = false; 1330 1331 ret = bdrv_co_pread(bs->file, 0, sizeof(header), &header, 0); 1332 if (ret < 0) { 1333 error_setg_errno(errp, -ret, "Could not read qcow2 header"); 1334 goto fail; 1335 } 1336 header.magic = be32_to_cpu(header.magic); 1337 header.version = be32_to_cpu(header.version); 1338 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 1339 header.backing_file_size = be32_to_cpu(header.backing_file_size); 1340 header.size = be64_to_cpu(header.size); 1341 header.cluster_bits = be32_to_cpu(header.cluster_bits); 1342 header.crypt_method = be32_to_cpu(header.crypt_method); 1343 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 1344 header.l1_size = be32_to_cpu(header.l1_size); 1345 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); 1346 header.refcount_table_clusters = 1347 be32_to_cpu(header.refcount_table_clusters); 1348 header.snapshots_offset = be64_to_cpu(header.snapshots_offset); 1349 header.nb_snapshots = be32_to_cpu(header.nb_snapshots); 1350 1351 if (header.magic != QCOW_MAGIC) { 1352 error_setg(errp, "Image is not in qcow2 format"); 1353 ret = -EINVAL; 1354 goto fail; 1355 } 1356 if (header.version < 2 || header.version > 3) { 1357 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); 1358 ret = -ENOTSUP; 1359 goto fail; 1360 } 1361 1362 s->qcow_version = header.version; 1363 1364 /* Initialise cluster size */ 1365 if (header.cluster_bits < MIN_CLUSTER_BITS || 1366 header.cluster_bits > MAX_CLUSTER_BITS) { 1367 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, 1368 header.cluster_bits); 1369 ret = -EINVAL; 1370 goto fail; 1371 } 1372 1373 s->cluster_bits = header.cluster_bits; 1374 s->cluster_size = 1 << s->cluster_bits; 1375 1376 /* Initialise version 3 header fields */ 1377 if (header.version == 2) { 1378 header.incompatible_features = 0; 1379 header.compatible_features = 0; 1380 header.autoclear_features = 0; 1381 header.refcount_order = 4; 1382 header.header_length = 72; 1383 } else { 1384 header.incompatible_features = 1385 be64_to_cpu(header.incompatible_features); 1386 header.compatible_features = be64_to_cpu(header.compatible_features); 1387 header.autoclear_features = be64_to_cpu(header.autoclear_features); 1388 header.refcount_order = be32_to_cpu(header.refcount_order); 1389 header.header_length = be32_to_cpu(header.header_length); 1390 1391 if (header.header_length < 104) { 1392 error_setg(errp, "qcow2 header too short"); 1393 ret = -EINVAL; 1394 goto fail; 1395 } 1396 } 1397 1398 if (header.header_length > s->cluster_size) { 1399 error_setg(errp, "qcow2 header exceeds cluster size"); 1400 ret = -EINVAL; 1401 goto fail; 1402 } 1403 1404 if (header.header_length > sizeof(header)) { 1405 s->unknown_header_fields_size = header.header_length - sizeof(header); 1406 s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); 1407 ret = bdrv_co_pread(bs->file, sizeof(header), 1408 s->unknown_header_fields_size, 1409 s->unknown_header_fields, 0); 1410 if (ret < 0) { 1411 error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " 1412 "fields"); 1413 goto fail; 1414 } 1415 } 1416 1417 if (header.backing_file_offset > s->cluster_size) { 1418 error_setg(errp, "Invalid backing file offset"); 1419 ret = -EINVAL; 1420 goto fail; 1421 } 1422 1423 if (header.backing_file_offset) { 1424 ext_end = header.backing_file_offset; 1425 } else { 1426 ext_end = 1 << header.cluster_bits; 1427 } 1428 1429 /* Handle feature bits */ 1430 s->incompatible_features = header.incompatible_features; 1431 s->compatible_features = header.compatible_features; 1432 s->autoclear_features = header.autoclear_features; 1433 1434 /* 1435 * Handle compression type 1436 * Older qcow2 images don't contain the compression type header. 1437 * Distinguish them by the header length and use 1438 * the only valid (default) compression type in that case 1439 */ 1440 if (header.header_length > offsetof(QCowHeader, compression_type)) { 1441 s->compression_type = header.compression_type; 1442 } else { 1443 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 1444 } 1445 1446 ret = validate_compression_type(s, errp); 1447 if (ret) { 1448 goto fail; 1449 } 1450 1451 if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { 1452 void *feature_table = NULL; 1453 qcow2_read_extensions(bs, header.header_length, ext_end, 1454 &feature_table, flags, NULL, NULL); 1455 report_unsupported_feature(errp, feature_table, 1456 s->incompatible_features & 1457 ~QCOW2_INCOMPAT_MASK); 1458 ret = -ENOTSUP; 1459 g_free(feature_table); 1460 goto fail; 1461 } 1462 1463 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 1464 /* Corrupt images may not be written to unless they are being repaired 1465 */ 1466 if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { 1467 error_setg(errp, "qcow2: Image is corrupt; cannot be opened " 1468 "read/write"); 1469 ret = -EACCES; 1470 goto fail; 1471 } 1472 } 1473 1474 s->subclusters_per_cluster = 1475 has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1; 1476 s->subcluster_size = s->cluster_size / s->subclusters_per_cluster; 1477 s->subcluster_bits = ctz32(s->subcluster_size); 1478 1479 if (s->subcluster_size < (1 << MIN_CLUSTER_BITS)) { 1480 error_setg(errp, "Unsupported subcluster size: %d", s->subcluster_size); 1481 ret = -EINVAL; 1482 goto fail; 1483 } 1484 1485 /* Check support for various header values */ 1486 if (header.refcount_order > 6) { 1487 error_setg(errp, "Reference count entry width too large; may not " 1488 "exceed 64 bits"); 1489 ret = -EINVAL; 1490 goto fail; 1491 } 1492 s->refcount_order = header.refcount_order; 1493 s->refcount_bits = 1 << s->refcount_order; 1494 s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); 1495 s->refcount_max += s->refcount_max - 1; 1496 1497 s->crypt_method_header = header.crypt_method; 1498 if (s->crypt_method_header) { 1499 if (bdrv_uses_whitelist() && 1500 s->crypt_method_header == QCOW_CRYPT_AES) { 1501 error_setg(errp, 1502 "Use of AES-CBC encrypted qcow2 images is no longer " 1503 "supported in system emulators"); 1504 error_append_hint(errp, 1505 "You can use 'qemu-img convert' to convert your " 1506 "image to an alternative supported format, such " 1507 "as unencrypted qcow2, or raw with the LUKS " 1508 "format instead.\n"); 1509 ret = -ENOSYS; 1510 goto fail; 1511 } 1512 1513 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1514 s->crypt_physical_offset = false; 1515 } else { 1516 /* Assuming LUKS and any future crypt methods we 1517 * add will all use physical offsets, due to the 1518 * fact that the alternative is insecure... */ 1519 s->crypt_physical_offset = true; 1520 } 1521 1522 bs->encrypted = true; 1523 } 1524 1525 s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s)); 1526 s->l2_size = 1 << s->l2_bits; 1527 /* 2^(s->refcount_order - 3) is the refcount width in bytes */ 1528 s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); 1529 s->refcount_block_size = 1 << s->refcount_block_bits; 1530 bs->total_sectors = header.size / BDRV_SECTOR_SIZE; 1531 s->csize_shift = (62 - (s->cluster_bits - 8)); 1532 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; 1533 s->cluster_offset_mask = (1LL << s->csize_shift) - 1; 1534 1535 s->refcount_table_offset = header.refcount_table_offset; 1536 s->refcount_table_size = 1537 header.refcount_table_clusters << (s->cluster_bits - 3); 1538 1539 if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { 1540 error_setg(errp, "Image does not contain a reference count table"); 1541 ret = -EINVAL; 1542 goto fail; 1543 } 1544 1545 ret = qcow2_validate_table(bs, s->refcount_table_offset, 1546 header.refcount_table_clusters, 1547 s->cluster_size, QCOW_MAX_REFTABLE_SIZE, 1548 "Reference count table", errp); 1549 if (ret < 0) { 1550 goto fail; 1551 } 1552 1553 if (!(flags & BDRV_O_CHECK)) { 1554 /* 1555 * The total size in bytes of the snapshot table is checked in 1556 * qcow2_read_snapshots() because the size of each snapshot is 1557 * variable and we don't know it yet. 1558 * Here we only check the offset and number of snapshots. 1559 */ 1560 ret = qcow2_validate_table(bs, header.snapshots_offset, 1561 header.nb_snapshots, 1562 sizeof(QCowSnapshotHeader), 1563 sizeof(QCowSnapshotHeader) * 1564 QCOW_MAX_SNAPSHOTS, 1565 "Snapshot table", errp); 1566 if (ret < 0) { 1567 goto fail; 1568 } 1569 } 1570 1571 /* read the level 1 table */ 1572 ret = qcow2_validate_table(bs, header.l1_table_offset, 1573 header.l1_size, L1E_SIZE, 1574 QCOW_MAX_L1_SIZE, "Active L1 table", errp); 1575 if (ret < 0) { 1576 goto fail; 1577 } 1578 s->l1_size = header.l1_size; 1579 s->l1_table_offset = header.l1_table_offset; 1580 1581 l1_vm_state_index = size_to_l1(s, header.size); 1582 if (l1_vm_state_index > INT_MAX) { 1583 error_setg(errp, "Image is too big"); 1584 ret = -EFBIG; 1585 goto fail; 1586 } 1587 s->l1_vm_state_index = l1_vm_state_index; 1588 1589 /* the L1 table must contain at least enough entries to put 1590 header.size bytes */ 1591 if (s->l1_size < s->l1_vm_state_index) { 1592 error_setg(errp, "L1 table is too small"); 1593 ret = -EINVAL; 1594 goto fail; 1595 } 1596 1597 if (s->l1_size > 0) { 1598 s->l1_table = qemu_try_blockalign(bs->file->bs, s->l1_size * L1E_SIZE); 1599 if (s->l1_table == NULL) { 1600 error_setg(errp, "Could not allocate L1 table"); 1601 ret = -ENOMEM; 1602 goto fail; 1603 } 1604 ret = bdrv_co_pread(bs->file, s->l1_table_offset, s->l1_size * L1E_SIZE, 1605 s->l1_table, 0); 1606 if (ret < 0) { 1607 error_setg_errno(errp, -ret, "Could not read L1 table"); 1608 goto fail; 1609 } 1610 for(i = 0;i < s->l1_size; i++) { 1611 s->l1_table[i] = be64_to_cpu(s->l1_table[i]); 1612 } 1613 } 1614 1615 /* Parse driver-specific options */ 1616 ret = qcow2_update_options(bs, options, flags, errp); 1617 if (ret < 0) { 1618 goto fail; 1619 } 1620 1621 s->flags = flags; 1622 1623 ret = qcow2_refcount_init(bs); 1624 if (ret != 0) { 1625 error_setg_errno(errp, -ret, "Could not initialize refcount handling"); 1626 goto fail; 1627 } 1628 1629 QLIST_INIT(&s->cluster_allocs); 1630 QTAILQ_INIT(&s->discards); 1631 1632 /* read qcow2 extensions */ 1633 if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, 1634 flags, &update_header, errp)) { 1635 ret = -EINVAL; 1636 goto fail; 1637 } 1638 1639 if (open_data_file) { 1640 /* Open external data file */ 1641 bdrv_graph_co_rdunlock(); 1642 s->data_file = bdrv_co_open_child(NULL, options, "data-file", bs, 1643 &child_of_bds, BDRV_CHILD_DATA, 1644 true, errp); 1645 bdrv_graph_co_rdlock(); 1646 if (*errp) { 1647 ret = -EINVAL; 1648 goto fail; 1649 } 1650 1651 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { 1652 if (!s->data_file && s->image_data_file) { 1653 bdrv_graph_co_rdunlock(); 1654 s->data_file = bdrv_co_open_child(s->image_data_file, options, 1655 "data-file", bs, 1656 &child_of_bds, 1657 BDRV_CHILD_DATA, false, errp); 1658 bdrv_graph_co_rdlock(); 1659 if (!s->data_file) { 1660 ret = -EINVAL; 1661 goto fail; 1662 } 1663 } 1664 if (!s->data_file) { 1665 error_setg(errp, "'data-file' is required for this image"); 1666 ret = -EINVAL; 1667 goto fail; 1668 } 1669 1670 /* No data here */ 1671 bs->file->role &= ~BDRV_CHILD_DATA; 1672 1673 /* Must succeed because we have given up permissions if anything */ 1674 bdrv_child_refresh_perms(bs, bs->file, &error_abort); 1675 } else { 1676 if (s->data_file) { 1677 error_setg(errp, "'data-file' can only be set for images with " 1678 "an external data file"); 1679 ret = -EINVAL; 1680 goto fail; 1681 } 1682 1683 s->data_file = bs->file; 1684 1685 if (data_file_is_raw(bs)) { 1686 error_setg(errp, "data-file-raw requires a data file"); 1687 ret = -EINVAL; 1688 goto fail; 1689 } 1690 } 1691 } 1692 1693 /* qcow2_read_extension may have set up the crypto context 1694 * if the crypt method needs a header region, some methods 1695 * don't need header extensions, so must check here 1696 */ 1697 if (s->crypt_method_header && !s->crypto) { 1698 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1699 unsigned int cflags = 0; 1700 if (flags & BDRV_O_NO_IO) { 1701 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 1702 } 1703 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 1704 NULL, NULL, cflags, errp); 1705 if (!s->crypto) { 1706 ret = -EINVAL; 1707 goto fail; 1708 } 1709 } else if (!(flags & BDRV_O_NO_IO)) { 1710 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1711 s->crypt_method_header); 1712 ret = -EINVAL; 1713 goto fail; 1714 } 1715 } 1716 1717 /* read the backing file name */ 1718 if (header.backing_file_offset != 0) { 1719 len = header.backing_file_size; 1720 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1721 len >= sizeof(bs->backing_file)) { 1722 error_setg(errp, "Backing file name too long"); 1723 ret = -EINVAL; 1724 goto fail; 1725 } 1726 1727 s->image_backing_file = g_malloc(len + 1); 1728 ret = bdrv_co_pread(bs->file, header.backing_file_offset, len, 1729 s->image_backing_file, 0); 1730 if (ret < 0) { 1731 error_setg_errno(errp, -ret, "Could not read backing file name"); 1732 goto fail; 1733 } 1734 s->image_backing_file[len] = '\0'; 1735 1736 /* 1737 * Update only when something has changed. This function is called by 1738 * qcow2_co_invalidate_cache(), and we do not want to reset 1739 * auto_backing_file unless necessary. 1740 */ 1741 if (!g_str_equal(s->image_backing_file, bs->backing_file)) { 1742 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1743 s->image_backing_file); 1744 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 1745 s->image_backing_file); 1746 } 1747 } 1748 1749 /* 1750 * Internal snapshots; skip reading them in check mode, because 1751 * we do not need them then, and we do not want to abort because 1752 * of a broken table. 1753 */ 1754 if (!(flags & BDRV_O_CHECK)) { 1755 s->snapshots_offset = header.snapshots_offset; 1756 s->nb_snapshots = header.nb_snapshots; 1757 1758 ret = qcow2_read_snapshots(bs, errp); 1759 if (ret < 0) { 1760 goto fail; 1761 } 1762 } 1763 1764 /* Clear unknown autoclear feature bits */ 1765 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1766 update_header = update_header && bdrv_is_writable(bs); 1767 if (update_header) { 1768 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1769 } 1770 1771 /* == Handle persistent dirty bitmaps == 1772 * 1773 * We want load dirty bitmaps in three cases: 1774 * 1775 * 1. Normal open of the disk in active mode, not related to invalidation 1776 * after migration. 1777 * 1778 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1779 * bitmaps are _not_ migrating through migration channel, i.e. 1780 * 'dirty-bitmaps' capability is disabled. 1781 * 1782 * 3. Invalidation of source vm after failed or canceled migration. 1783 * This is a very interesting case. There are two possible types of 1784 * bitmaps: 1785 * 1786 * A. Stored on inactivation and removed. They should be loaded from the 1787 * image. 1788 * 1789 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1790 * the migration channel (with dirty-bitmaps capability). 1791 * 1792 * On the other hand, there are two possible sub-cases: 1793 * 1794 * 3.1 disk was changed by somebody else while were inactive. In this 1795 * case all in-RAM dirty bitmaps (both persistent and not) are 1796 * definitely invalid. And we don't have any method to determine 1797 * this. 1798 * 1799 * Simple and safe thing is to just drop all the bitmaps of type B on 1800 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1801 * 1802 * On the other hand, resuming source vm, if disk was already changed 1803 * is a bad thing anyway: not only bitmaps, the whole vm state is 1804 * out of sync with disk. 1805 * 1806 * This means, that user or management tool, who for some reason 1807 * decided to resume source vm, after disk was already changed by 1808 * target vm, should at least drop all dirty bitmaps by hand. 1809 * 1810 * So, we can ignore this case for now, but TODO: "generation" 1811 * extension for qcow2, to determine, that image was changed after 1812 * last inactivation. And if it is changed, we will drop (or at least 1813 * mark as 'invalid' all the bitmaps of type B, both persistent 1814 * and not). 1815 * 1816 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1817 * to disk ('dirty-bitmaps' capability disabled), or not saved 1818 * ('dirty-bitmaps' capability enabled), but we don't need to care 1819 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1820 * and not stored has flag IN_USE=1 in the image and will be skipped 1821 * on loading. 1822 * 1823 * One remaining possible case when we don't want load bitmaps: 1824 * 1825 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1826 * will be loaded on invalidation, no needs try loading them before) 1827 */ 1828 1829 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1830 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1831 bool header_updated; 1832 if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) { 1833 ret = -EINVAL; 1834 goto fail; 1835 } 1836 1837 update_header = update_header && !header_updated; 1838 } 1839 1840 if (update_header) { 1841 ret = qcow2_update_header(bs); 1842 if (ret < 0) { 1843 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1844 goto fail; 1845 } 1846 } 1847 1848 bs->supported_zero_flags = header.version >= 3 ? 1849 BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; 1850 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; 1851 1852 /* Repair image if dirty */ 1853 if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) && 1854 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1855 BdrvCheckResult result = {0}; 1856 1857 ret = qcow2_co_check_locked(bs, &result, 1858 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1859 if (ret < 0 || result.check_errors) { 1860 if (ret >= 0) { 1861 ret = -EIO; 1862 } 1863 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1864 goto fail; 1865 } 1866 } 1867 1868 #ifdef DEBUG_ALLOC 1869 { 1870 BdrvCheckResult result = {0}; 1871 qcow2_check_refcounts(bs, &result, 0); 1872 } 1873 #endif 1874 1875 qemu_co_queue_init(&s->thread_task_queue); 1876 1877 return ret; 1878 1879 fail: 1880 g_free(s->image_data_file); 1881 if (open_data_file && has_data_file(bs)) { 1882 bdrv_graph_co_rdunlock(); 1883 bdrv_co_unref_child(bs, s->data_file); 1884 bdrv_graph_co_rdlock(); 1885 s->data_file = NULL; 1886 } 1887 g_free(s->unknown_header_fields); 1888 cleanup_unknown_header_ext(bs); 1889 qcow2_free_snapshots(bs); 1890 qcow2_refcount_close(bs); 1891 qemu_vfree(s->l1_table); 1892 /* else pre-write overlap checks in cache_destroy may crash */ 1893 s->l1_table = NULL; 1894 cache_clean_timer_del(bs); 1895 if (s->l2_table_cache) { 1896 qcow2_cache_destroy(s->l2_table_cache); 1897 } 1898 if (s->refcount_block_cache) { 1899 qcow2_cache_destroy(s->refcount_block_cache); 1900 } 1901 qcrypto_block_free(s->crypto); 1902 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1903 return ret; 1904 } 1905 1906 typedef struct QCow2OpenCo { 1907 BlockDriverState *bs; 1908 QDict *options; 1909 int flags; 1910 Error **errp; 1911 int ret; 1912 } QCow2OpenCo; 1913 1914 static void coroutine_fn qcow2_open_entry(void *opaque) 1915 { 1916 QCow2OpenCo *qoc = opaque; 1917 BDRVQcow2State *s = qoc->bs->opaque; 1918 1919 GRAPH_RDLOCK_GUARD(); 1920 1921 qemu_co_mutex_lock(&s->lock); 1922 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true, 1923 qoc->errp); 1924 qemu_co_mutex_unlock(&s->lock); 1925 1926 aio_wait_kick(); 1927 } 1928 1929 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1930 Error **errp) 1931 { 1932 BDRVQcow2State *s = bs->opaque; 1933 QCow2OpenCo qoc = { 1934 .bs = bs, 1935 .options = options, 1936 .flags = flags, 1937 .errp = errp, 1938 .ret = -EINPROGRESS 1939 }; 1940 int ret; 1941 1942 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 1943 if (ret < 0) { 1944 return ret; 1945 } 1946 1947 /* Initialise locks */ 1948 qemu_co_mutex_init(&s->lock); 1949 1950 assert(!qemu_in_coroutine()); 1951 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1952 1953 aio_co_enter(bdrv_get_aio_context(bs), 1954 qemu_coroutine_create(qcow2_open_entry, &qoc)); 1955 AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS); 1956 1957 return qoc.ret; 1958 } 1959 1960 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1961 { 1962 BDRVQcow2State *s = bs->opaque; 1963 1964 if (bs->encrypted) { 1965 /* Encryption works on a sector granularity */ 1966 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1967 } 1968 bs->bl.pwrite_zeroes_alignment = s->subcluster_size; 1969 bs->bl.pdiscard_alignment = s->cluster_size; 1970 } 1971 1972 static int GRAPH_UNLOCKED 1973 qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue, 1974 Error **errp) 1975 { 1976 BDRVQcow2State *s = state->bs->opaque; 1977 Qcow2ReopenState *r; 1978 int ret; 1979 1980 GLOBAL_STATE_CODE(); 1981 GRAPH_RDLOCK_GUARD_MAINLOOP(); 1982 1983 r = g_new0(Qcow2ReopenState, 1); 1984 state->opaque = r; 1985 1986 ret = qcow2_update_options_prepare(state->bs, r, state->options, 1987 state->flags, errp); 1988 if (ret < 0) { 1989 goto fail; 1990 } 1991 1992 /* We need to write out any unwritten data if we reopen read-only. */ 1993 if ((state->flags & BDRV_O_RDWR) == 0) { 1994 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 1995 if (ret < 0) { 1996 goto fail; 1997 } 1998 1999 ret = bdrv_flush(state->bs); 2000 if (ret < 0) { 2001 goto fail; 2002 } 2003 2004 ret = qcow2_mark_clean(state->bs); 2005 if (ret < 0) { 2006 goto fail; 2007 } 2008 } 2009 2010 /* 2011 * Without an external data file, s->data_file points to the same BdrvChild 2012 * as bs->file. It needs to be resynced after reopen because bs->file may 2013 * be changed. We can't use it in the meantime. 2014 */ 2015 if (!has_data_file(state->bs)) { 2016 assert(s->data_file == state->bs->file); 2017 s->data_file = NULL; 2018 } 2019 2020 return 0; 2021 2022 fail: 2023 qcow2_update_options_abort(state->bs, r); 2024 g_free(r); 2025 return ret; 2026 } 2027 2028 static void qcow2_reopen_commit(BDRVReopenState *state) 2029 { 2030 BDRVQcow2State *s = state->bs->opaque; 2031 2032 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2033 2034 qcow2_update_options_commit(state->bs, state->opaque); 2035 if (!s->data_file) { 2036 /* 2037 * If we don't have an external data file, s->data_file was cleared by 2038 * qcow2_reopen_prepare() and needs to be updated. 2039 */ 2040 s->data_file = state->bs->file; 2041 } 2042 g_free(state->opaque); 2043 } 2044 2045 static void qcow2_reopen_commit_post(BDRVReopenState *state) 2046 { 2047 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2048 2049 if (state->flags & BDRV_O_RDWR) { 2050 Error *local_err = NULL; 2051 2052 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { 2053 /* 2054 * This is not fatal, bitmaps just left read-only, so all following 2055 * writes will fail. User can remove read-only bitmaps to unblock 2056 * writes or retry reopen. 2057 */ 2058 error_reportf_err(local_err, 2059 "%s: Failed to make dirty bitmaps writable: ", 2060 bdrv_get_node_name(state->bs)); 2061 } 2062 } 2063 } 2064 2065 static void qcow2_reopen_abort(BDRVReopenState *state) 2066 { 2067 BDRVQcow2State *s = state->bs->opaque; 2068 2069 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2070 2071 if (!s->data_file) { 2072 /* 2073 * If we don't have an external data file, s->data_file was cleared by 2074 * qcow2_reopen_prepare() and needs to be restored. 2075 */ 2076 s->data_file = state->bs->file; 2077 } 2078 qcow2_update_options_abort(state->bs, state->opaque); 2079 g_free(state->opaque); 2080 } 2081 2082 static void qcow2_join_options(QDict *options, QDict *old_options) 2083 { 2084 bool has_new_overlap_template = 2085 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 2086 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 2087 bool has_new_total_cache_size = 2088 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 2089 bool has_all_cache_options; 2090 2091 /* New overlap template overrides all old overlap options */ 2092 if (has_new_overlap_template) { 2093 qdict_del(old_options, QCOW2_OPT_OVERLAP); 2094 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 2095 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 2096 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 2097 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 2098 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 2099 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 2100 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 2101 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 2102 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 2103 } 2104 2105 /* New total cache size overrides all old options */ 2106 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 2107 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 2108 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2109 } 2110 2111 qdict_join(options, old_options, false); 2112 2113 /* 2114 * If after merging all cache size options are set, an old total size is 2115 * overwritten. Do keep all options, however, if all three are new. The 2116 * resulting error message is what we want to happen. 2117 */ 2118 has_all_cache_options = 2119 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 2120 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 2121 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2122 2123 if (has_all_cache_options && !has_new_total_cache_size) { 2124 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 2125 } 2126 } 2127 2128 static int coroutine_fn GRAPH_RDLOCK 2129 qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, 2130 int64_t count, int64_t *pnum, int64_t *map, 2131 BlockDriverState **file) 2132 { 2133 BDRVQcow2State *s = bs->opaque; 2134 uint64_t host_offset; 2135 unsigned int bytes; 2136 QCow2SubclusterType type; 2137 int ret, status = 0; 2138 2139 qemu_co_mutex_lock(&s->lock); 2140 2141 if (!s->metadata_preallocation_checked) { 2142 ret = qcow2_detect_metadata_preallocation(bs); 2143 s->metadata_preallocation = (ret == 1); 2144 s->metadata_preallocation_checked = true; 2145 } 2146 2147 bytes = MIN(INT_MAX, count); 2148 ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type); 2149 qemu_co_mutex_unlock(&s->lock); 2150 if (ret < 0) { 2151 return ret; 2152 } 2153 2154 *pnum = bytes; 2155 2156 if ((type == QCOW2_SUBCLUSTER_NORMAL || 2157 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2158 type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) { 2159 *map = host_offset; 2160 *file = s->data_file->bs; 2161 status |= BDRV_BLOCK_OFFSET_VALID; 2162 } 2163 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2164 type == QCOW2_SUBCLUSTER_ZERO_ALLOC) { 2165 status |= BDRV_BLOCK_ZERO; 2166 } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 2167 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) { 2168 status |= BDRV_BLOCK_DATA; 2169 } 2170 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && 2171 (status & BDRV_BLOCK_OFFSET_VALID)) 2172 { 2173 status |= BDRV_BLOCK_RECURSE; 2174 } 2175 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 2176 status |= BDRV_BLOCK_COMPRESSED; 2177 } 2178 return status; 2179 } 2180 2181 static int coroutine_fn GRAPH_RDLOCK 2182 qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2) 2183 { 2184 int ret = 0; 2185 QCowL2Meta *l2meta = *pl2meta; 2186 2187 while (l2meta != NULL) { 2188 QCowL2Meta *next; 2189 2190 if (link_l2) { 2191 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 2192 if (ret) { 2193 goto out; 2194 } 2195 } else { 2196 qcow2_alloc_cluster_abort(bs, l2meta); 2197 } 2198 2199 /* Take the request off the list of running requests */ 2200 QLIST_REMOVE(l2meta, next_in_flight); 2201 2202 qemu_co_queue_restart_all(&l2meta->dependent_requests); 2203 2204 next = l2meta->next; 2205 g_free(l2meta); 2206 l2meta = next; 2207 } 2208 out: 2209 *pl2meta = l2meta; 2210 return ret; 2211 } 2212 2213 static int coroutine_fn GRAPH_RDLOCK 2214 qcow2_co_preadv_encrypted(BlockDriverState *bs, 2215 uint64_t host_offset, 2216 uint64_t offset, 2217 uint64_t bytes, 2218 QEMUIOVector *qiov, 2219 uint64_t qiov_offset) 2220 { 2221 int ret; 2222 BDRVQcow2State *s = bs->opaque; 2223 uint8_t *buf; 2224 2225 assert(bs->encrypted && s->crypto); 2226 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2227 2228 /* 2229 * For encrypted images, read everything into a temporary 2230 * contiguous buffer on which the AES functions can work. 2231 * Also, decryption in a separate buffer is better as it 2232 * prevents the guest from learning information about the 2233 * encrypted nature of the virtual disk. 2234 */ 2235 2236 buf = qemu_try_blockalign(s->data_file->bs, bytes); 2237 if (buf == NULL) { 2238 return -ENOMEM; 2239 } 2240 2241 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2242 ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0); 2243 if (ret < 0) { 2244 goto fail; 2245 } 2246 2247 if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0) 2248 { 2249 ret = -EIO; 2250 goto fail; 2251 } 2252 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); 2253 2254 fail: 2255 qemu_vfree(buf); 2256 2257 return ret; 2258 } 2259 2260 typedef struct Qcow2AioTask { 2261 AioTask task; 2262 2263 BlockDriverState *bs; 2264 QCow2SubclusterType subcluster_type; /* only for read */ 2265 uint64_t host_offset; /* or l2_entry for compressed read */ 2266 uint64_t offset; 2267 uint64_t bytes; 2268 QEMUIOVector *qiov; 2269 uint64_t qiov_offset; 2270 QCowL2Meta *l2meta; /* only for write */ 2271 } Qcow2AioTask; 2272 2273 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); 2274 static coroutine_fn int qcow2_add_task(BlockDriverState *bs, 2275 AioTaskPool *pool, 2276 AioTaskFunc func, 2277 QCow2SubclusterType subcluster_type, 2278 uint64_t host_offset, 2279 uint64_t offset, 2280 uint64_t bytes, 2281 QEMUIOVector *qiov, 2282 size_t qiov_offset, 2283 QCowL2Meta *l2meta) 2284 { 2285 Qcow2AioTask local_task; 2286 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; 2287 2288 *task = (Qcow2AioTask) { 2289 .task.func = func, 2290 .bs = bs, 2291 .subcluster_type = subcluster_type, 2292 .qiov = qiov, 2293 .host_offset = host_offset, 2294 .offset = offset, 2295 .bytes = bytes, 2296 .qiov_offset = qiov_offset, 2297 .l2meta = l2meta, 2298 }; 2299 2300 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, 2301 func == qcow2_co_preadv_task_entry ? "read" : "write", 2302 subcluster_type, host_offset, offset, bytes, 2303 qiov, qiov_offset); 2304 2305 if (!pool) { 2306 return func(&task->task); 2307 } 2308 2309 aio_task_pool_start_task(pool, &task->task); 2310 2311 return 0; 2312 } 2313 2314 static int coroutine_fn GRAPH_RDLOCK 2315 qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type, 2316 uint64_t host_offset, uint64_t offset, uint64_t bytes, 2317 QEMUIOVector *qiov, size_t qiov_offset) 2318 { 2319 BDRVQcow2State *s = bs->opaque; 2320 2321 switch (subc_type) { 2322 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 2323 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 2324 /* Both zero types are handled in qcow2_co_preadv_part */ 2325 g_assert_not_reached(); 2326 2327 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 2328 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 2329 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ 2330 2331 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2332 return bdrv_co_preadv_part(bs->backing, offset, bytes, 2333 qiov, qiov_offset, 0); 2334 2335 case QCOW2_SUBCLUSTER_COMPRESSED: 2336 return qcow2_co_preadv_compressed(bs, host_offset, 2337 offset, bytes, qiov, qiov_offset); 2338 2339 case QCOW2_SUBCLUSTER_NORMAL: 2340 if (bs->encrypted) { 2341 return qcow2_co_preadv_encrypted(bs, host_offset, 2342 offset, bytes, qiov, qiov_offset); 2343 } 2344 2345 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2346 return bdrv_co_preadv_part(s->data_file, host_offset, 2347 bytes, qiov, qiov_offset, 0); 2348 2349 default: 2350 g_assert_not_reached(); 2351 } 2352 2353 g_assert_not_reached(); 2354 } 2355 2356 /* 2357 * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds 2358 * the graph lock and keeps it until this coroutine has terminated. 2359 */ 2360 static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task) 2361 { 2362 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2363 2364 assert(!t->l2meta); 2365 2366 return qcow2_co_preadv_task(t->bs, t->subcluster_type, 2367 t->host_offset, t->offset, t->bytes, 2368 t->qiov, t->qiov_offset); 2369 } 2370 2371 static int coroutine_fn GRAPH_RDLOCK 2372 qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2373 QEMUIOVector *qiov, size_t qiov_offset, 2374 BdrvRequestFlags flags) 2375 { 2376 BDRVQcow2State *s = bs->opaque; 2377 int ret = 0; 2378 unsigned int cur_bytes; /* number of bytes in current iteration */ 2379 uint64_t host_offset = 0; 2380 QCow2SubclusterType type; 2381 AioTaskPool *aio = NULL; 2382 2383 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2384 /* prepare next request */ 2385 cur_bytes = MIN(bytes, INT_MAX); 2386 if (s->crypto) { 2387 cur_bytes = MIN(cur_bytes, 2388 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2389 } 2390 2391 qemu_co_mutex_lock(&s->lock); 2392 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, 2393 &host_offset, &type); 2394 qemu_co_mutex_unlock(&s->lock); 2395 if (ret < 0) { 2396 goto out; 2397 } 2398 2399 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2400 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2401 (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) || 2402 (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing)) 2403 { 2404 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2405 } else { 2406 if (!aio && cur_bytes != bytes) { 2407 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2408 } 2409 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type, 2410 host_offset, offset, cur_bytes, 2411 qiov, qiov_offset, NULL); 2412 if (ret < 0) { 2413 goto out; 2414 } 2415 } 2416 2417 bytes -= cur_bytes; 2418 offset += cur_bytes; 2419 qiov_offset += cur_bytes; 2420 } 2421 2422 out: 2423 if (aio) { 2424 aio_task_pool_wait_all(aio); 2425 if (ret == 0) { 2426 ret = aio_task_pool_status(aio); 2427 } 2428 g_free(aio); 2429 } 2430 2431 return ret; 2432 } 2433 2434 /* Check if it's possible to merge a write request with the writing of 2435 * the data from the COW regions */ 2436 static bool merge_cow(uint64_t offset, unsigned bytes, 2437 QEMUIOVector *qiov, size_t qiov_offset, 2438 QCowL2Meta *l2meta) 2439 { 2440 QCowL2Meta *m; 2441 2442 for (m = l2meta; m != NULL; m = m->next) { 2443 /* If both COW regions are empty then there's nothing to merge */ 2444 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2445 continue; 2446 } 2447 2448 /* If COW regions are handled already, skip this too */ 2449 if (m->skip_cow) { 2450 continue; 2451 } 2452 2453 /* 2454 * The write request should start immediately after the first 2455 * COW region. This does not always happen because the area 2456 * touched by the request can be larger than the one defined 2457 * by @m (a single request can span an area consisting of a 2458 * mix of previously unallocated and allocated clusters, that 2459 * is why @l2meta is a list). 2460 */ 2461 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2462 /* In this case the request starts before this region */ 2463 assert(offset < l2meta_cow_start(m)); 2464 assert(m->cow_start.nb_bytes == 0); 2465 continue; 2466 } 2467 2468 /* The write request should end immediately before the second 2469 * COW region (see above for why it does not always happen) */ 2470 if (m->offset + m->cow_end.offset != offset + bytes) { 2471 assert(offset + bytes > m->offset + m->cow_end.offset); 2472 assert(m->cow_end.nb_bytes == 0); 2473 continue; 2474 } 2475 2476 /* Make sure that adding both COW regions to the QEMUIOVector 2477 * does not exceed IOV_MAX */ 2478 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { 2479 continue; 2480 } 2481 2482 m->data_qiov = qiov; 2483 m->data_qiov_offset = qiov_offset; 2484 return true; 2485 } 2486 2487 return false; 2488 } 2489 2490 /* 2491 * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error. 2492 * Note that returning 0 does not guarantee non-zero data. 2493 */ 2494 static int coroutine_fn GRAPH_RDLOCK 2495 is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) 2496 { 2497 /* 2498 * This check is designed for optimization shortcut so it must be 2499 * efficient. 2500 * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is 2501 * faster (but not as accurate and can result in false negatives). 2502 */ 2503 int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset, 2504 m->cow_start.nb_bytes); 2505 if (ret <= 0) { 2506 return ret; 2507 } 2508 2509 return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset, 2510 m->cow_end.nb_bytes); 2511 } 2512 2513 static int coroutine_fn GRAPH_RDLOCK 2514 handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) 2515 { 2516 BDRVQcow2State *s = bs->opaque; 2517 QCowL2Meta *m; 2518 2519 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { 2520 return 0; 2521 } 2522 2523 if (bs->encrypted) { 2524 return 0; 2525 } 2526 2527 for (m = l2meta; m != NULL; m = m->next) { 2528 int ret; 2529 uint64_t start_offset = m->alloc_offset + m->cow_start.offset; 2530 unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes - 2531 m->cow_start.offset; 2532 2533 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { 2534 continue; 2535 } 2536 2537 ret = is_zero_cow(bs, m); 2538 if (ret < 0) { 2539 return ret; 2540 } else if (ret == 0) { 2541 continue; 2542 } 2543 2544 /* 2545 * instead of writing zero COW buffers, 2546 * efficiently zero out the whole clusters 2547 */ 2548 2549 ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes, 2550 true); 2551 if (ret < 0) { 2552 return ret; 2553 } 2554 2555 BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); 2556 ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes, 2557 BDRV_REQ_NO_FALLBACK); 2558 if (ret < 0) { 2559 if (ret != -ENOTSUP && ret != -EAGAIN) { 2560 return ret; 2561 } 2562 continue; 2563 } 2564 2565 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); 2566 m->skip_cow = true; 2567 } 2568 return 0; 2569 } 2570 2571 /* 2572 * qcow2_co_pwritev_task 2573 * Called with s->lock unlocked 2574 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must 2575 * not use it somehow after qcow2_co_pwritev_task() call 2576 */ 2577 static coroutine_fn GRAPH_RDLOCK 2578 int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset, 2579 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, 2580 uint64_t qiov_offset, QCowL2Meta *l2meta) 2581 { 2582 int ret; 2583 BDRVQcow2State *s = bs->opaque; 2584 void *crypt_buf = NULL; 2585 QEMUIOVector encrypted_qiov; 2586 2587 if (bs->encrypted) { 2588 assert(s->crypto); 2589 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2590 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); 2591 if (crypt_buf == NULL) { 2592 ret = -ENOMEM; 2593 goto out_unlocked; 2594 } 2595 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); 2596 2597 if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) { 2598 ret = -EIO; 2599 goto out_unlocked; 2600 } 2601 2602 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); 2603 qiov = &encrypted_qiov; 2604 qiov_offset = 0; 2605 } 2606 2607 /* Try to efficiently initialize the physical space with zeroes */ 2608 ret = handle_alloc_space(bs, l2meta); 2609 if (ret < 0) { 2610 goto out_unlocked; 2611 } 2612 2613 /* 2614 * If we need to do COW, check if it's possible to merge the 2615 * writing of the guest data together with that of the COW regions. 2616 * If it's not possible (or not necessary) then write the 2617 * guest data now. 2618 */ 2619 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { 2620 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 2621 trace_qcow2_writev_data(qemu_coroutine_self(), host_offset); 2622 ret = bdrv_co_pwritev_part(s->data_file, host_offset, 2623 bytes, qiov, qiov_offset, 0); 2624 if (ret < 0) { 2625 goto out_unlocked; 2626 } 2627 } 2628 2629 qemu_co_mutex_lock(&s->lock); 2630 2631 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2632 goto out_locked; 2633 2634 out_unlocked: 2635 qemu_co_mutex_lock(&s->lock); 2636 2637 out_locked: 2638 qcow2_handle_l2meta(bs, &l2meta, false); 2639 qemu_co_mutex_unlock(&s->lock); 2640 2641 qemu_vfree(crypt_buf); 2642 2643 return ret; 2644 } 2645 2646 /* 2647 * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds 2648 * the graph lock and keeps it until this coroutine has terminated. 2649 */ 2650 static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task) 2651 { 2652 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2653 2654 assert(!t->subcluster_type); 2655 2656 return qcow2_co_pwritev_task(t->bs, t->host_offset, 2657 t->offset, t->bytes, t->qiov, t->qiov_offset, 2658 t->l2meta); 2659 } 2660 2661 static int coroutine_fn GRAPH_RDLOCK 2662 qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2663 QEMUIOVector *qiov, size_t qiov_offset, 2664 BdrvRequestFlags flags) 2665 { 2666 BDRVQcow2State *s = bs->opaque; 2667 int offset_in_cluster; 2668 int ret; 2669 unsigned int cur_bytes; /* number of sectors in current iteration */ 2670 uint64_t host_offset; 2671 QCowL2Meta *l2meta = NULL; 2672 AioTaskPool *aio = NULL; 2673 2674 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2675 2676 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2677 2678 l2meta = NULL; 2679 2680 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2681 offset_in_cluster = offset_into_cluster(s, offset); 2682 cur_bytes = MIN(bytes, INT_MAX); 2683 if (bs->encrypted) { 2684 cur_bytes = MIN(cur_bytes, 2685 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2686 - offset_in_cluster); 2687 } 2688 2689 qemu_co_mutex_lock(&s->lock); 2690 2691 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 2692 &host_offset, &l2meta); 2693 if (ret < 0) { 2694 goto out_locked; 2695 } 2696 2697 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, 2698 cur_bytes, true); 2699 if (ret < 0) { 2700 goto out_locked; 2701 } 2702 2703 qemu_co_mutex_unlock(&s->lock); 2704 2705 if (!aio && cur_bytes != bytes) { 2706 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2707 } 2708 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, 2709 host_offset, offset, 2710 cur_bytes, qiov, qiov_offset, l2meta); 2711 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ 2712 if (ret < 0) { 2713 goto fail_nometa; 2714 } 2715 2716 bytes -= cur_bytes; 2717 offset += cur_bytes; 2718 qiov_offset += cur_bytes; 2719 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2720 } 2721 ret = 0; 2722 2723 qemu_co_mutex_lock(&s->lock); 2724 2725 out_locked: 2726 qcow2_handle_l2meta(bs, &l2meta, false); 2727 2728 qemu_co_mutex_unlock(&s->lock); 2729 2730 fail_nometa: 2731 if (aio) { 2732 aio_task_pool_wait_all(aio); 2733 if (ret == 0) { 2734 ret = aio_task_pool_status(aio); 2735 } 2736 g_free(aio); 2737 } 2738 2739 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2740 2741 return ret; 2742 } 2743 2744 static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs) 2745 { 2746 BDRVQcow2State *s = bs->opaque; 2747 int ret, result = 0; 2748 Error *local_err = NULL; 2749 2750 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); 2751 if (local_err != NULL) { 2752 result = -EINVAL; 2753 error_reportf_err(local_err, "Lost persistent bitmaps during " 2754 "inactivation of node '%s': ", 2755 bdrv_get_device_or_node_name(bs)); 2756 } 2757 2758 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2759 if (ret) { 2760 result = ret; 2761 error_report("Failed to flush the L2 table cache: %s", 2762 strerror(-ret)); 2763 } 2764 2765 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2766 if (ret) { 2767 result = ret; 2768 error_report("Failed to flush the refcount block cache: %s", 2769 strerror(-ret)); 2770 } 2771 2772 if (result == 0) { 2773 qcow2_mark_clean(bs); 2774 } 2775 2776 return result; 2777 } 2778 2779 static void coroutine_mixed_fn GRAPH_RDLOCK 2780 qcow2_do_close(BlockDriverState *bs, bool close_data_file) 2781 { 2782 BDRVQcow2State *s = bs->opaque; 2783 qemu_vfree(s->l1_table); 2784 /* else pre-write overlap checks in cache_destroy may crash */ 2785 s->l1_table = NULL; 2786 2787 if (!(s->flags & BDRV_O_INACTIVE)) { 2788 qcow2_inactivate(bs); 2789 } 2790 2791 cache_clean_timer_del(bs); 2792 qcow2_cache_destroy(s->l2_table_cache); 2793 qcow2_cache_destroy(s->refcount_block_cache); 2794 2795 qcrypto_block_free(s->crypto); 2796 s->crypto = NULL; 2797 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 2798 2799 g_free(s->unknown_header_fields); 2800 cleanup_unknown_header_ext(bs); 2801 2802 g_free(s->image_data_file); 2803 g_free(s->image_backing_file); 2804 g_free(s->image_backing_format); 2805 2806 if (close_data_file && has_data_file(bs)) { 2807 GLOBAL_STATE_CODE(); 2808 bdrv_graph_rdunlock_main_loop(); 2809 bdrv_graph_wrlock(); 2810 bdrv_unref_child(bs, s->data_file); 2811 bdrv_graph_wrunlock(); 2812 s->data_file = NULL; 2813 bdrv_graph_rdlock_main_loop(); 2814 } 2815 2816 qcow2_refcount_close(bs); 2817 qcow2_free_snapshots(bs); 2818 } 2819 2820 static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs) 2821 { 2822 GLOBAL_STATE_CODE(); 2823 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2824 2825 qcow2_do_close(bs, true); 2826 } 2827 2828 static void coroutine_fn GRAPH_RDLOCK 2829 qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp) 2830 { 2831 ERRP_GUARD(); 2832 BDRVQcow2State *s = bs->opaque; 2833 BdrvChild *data_file; 2834 int flags = s->flags; 2835 QCryptoBlock *crypto = NULL; 2836 QDict *options; 2837 int ret; 2838 2839 /* 2840 * Backing files are read-only which makes all of their metadata immutable, 2841 * that means we don't have to worry about reopening them here. 2842 */ 2843 2844 crypto = s->crypto; 2845 s->crypto = NULL; 2846 2847 /* 2848 * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it, 2849 * and then prevent qcow2_do_open() from opening it), because this function 2850 * runs in the I/O path and as such we must not invoke global-state 2851 * functions like bdrv_unref_child() and bdrv_open_child(). 2852 */ 2853 2854 qcow2_do_close(bs, false); 2855 2856 data_file = s->data_file; 2857 memset(s, 0, sizeof(BDRVQcow2State)); 2858 s->data_file = data_file; 2859 2860 options = qdict_clone_shallow(bs->options); 2861 2862 flags &= ~BDRV_O_INACTIVE; 2863 qemu_co_mutex_lock(&s->lock); 2864 ret = qcow2_do_open(bs, options, flags, false, errp); 2865 qemu_co_mutex_unlock(&s->lock); 2866 qobject_unref(options); 2867 if (ret < 0) { 2868 error_prepend(errp, "Could not reopen qcow2 layer: "); 2869 bs->drv = NULL; 2870 return; 2871 } 2872 2873 s->crypto = crypto; 2874 } 2875 2876 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2877 size_t len, size_t buflen) 2878 { 2879 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2880 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2881 2882 if (buflen < ext_len) { 2883 return -ENOSPC; 2884 } 2885 2886 *ext_backing_fmt = (QCowExtension) { 2887 .magic = cpu_to_be32(magic), 2888 .len = cpu_to_be32(len), 2889 }; 2890 2891 if (len) { 2892 memcpy(buf + sizeof(QCowExtension), s, len); 2893 } 2894 2895 return ext_len; 2896 } 2897 2898 /* 2899 * Updates the qcow2 header, including the variable length parts of it, i.e. 2900 * the backing file name and all extensions. qcow2 was not designed to allow 2901 * such changes, so if we run out of space (we can only use the first cluster) 2902 * this function may fail. 2903 * 2904 * Returns 0 on success, -errno in error cases. 2905 */ 2906 int qcow2_update_header(BlockDriverState *bs) 2907 { 2908 BDRVQcow2State *s = bs->opaque; 2909 QCowHeader *header; 2910 char *buf; 2911 size_t buflen = s->cluster_size; 2912 int ret; 2913 uint64_t total_size; 2914 uint32_t refcount_table_clusters; 2915 size_t header_length; 2916 Qcow2UnknownHeaderExtension *uext; 2917 2918 buf = qemu_blockalign(bs, buflen); 2919 2920 /* Header structure */ 2921 header = (QCowHeader*) buf; 2922 2923 if (buflen < sizeof(*header)) { 2924 ret = -ENOSPC; 2925 goto fail; 2926 } 2927 2928 header_length = sizeof(*header) + s->unknown_header_fields_size; 2929 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2930 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2931 2932 ret = validate_compression_type(s, NULL); 2933 if (ret) { 2934 goto fail; 2935 } 2936 2937 *header = (QCowHeader) { 2938 /* Version 2 fields */ 2939 .magic = cpu_to_be32(QCOW_MAGIC), 2940 .version = cpu_to_be32(s->qcow_version), 2941 .backing_file_offset = 0, 2942 .backing_file_size = 0, 2943 .cluster_bits = cpu_to_be32(s->cluster_bits), 2944 .size = cpu_to_be64(total_size), 2945 .crypt_method = cpu_to_be32(s->crypt_method_header), 2946 .l1_size = cpu_to_be32(s->l1_size), 2947 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2948 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2949 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2950 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2951 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2952 2953 /* Version 3 fields */ 2954 .incompatible_features = cpu_to_be64(s->incompatible_features), 2955 .compatible_features = cpu_to_be64(s->compatible_features), 2956 .autoclear_features = cpu_to_be64(s->autoclear_features), 2957 .refcount_order = cpu_to_be32(s->refcount_order), 2958 .header_length = cpu_to_be32(header_length), 2959 .compression_type = s->compression_type, 2960 }; 2961 2962 /* For older versions, write a shorter header */ 2963 switch (s->qcow_version) { 2964 case 2: 2965 ret = offsetof(QCowHeader, incompatible_features); 2966 break; 2967 case 3: 2968 ret = sizeof(*header); 2969 break; 2970 default: 2971 ret = -EINVAL; 2972 goto fail; 2973 } 2974 2975 buf += ret; 2976 buflen -= ret; 2977 memset(buf, 0, buflen); 2978 2979 /* Preserve any unknown field in the header */ 2980 if (s->unknown_header_fields_size) { 2981 if (buflen < s->unknown_header_fields_size) { 2982 ret = -ENOSPC; 2983 goto fail; 2984 } 2985 2986 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 2987 buf += s->unknown_header_fields_size; 2988 buflen -= s->unknown_header_fields_size; 2989 } 2990 2991 /* Backing file format header extension */ 2992 if (s->image_backing_format) { 2993 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 2994 s->image_backing_format, 2995 strlen(s->image_backing_format), 2996 buflen); 2997 if (ret < 0) { 2998 goto fail; 2999 } 3000 3001 buf += ret; 3002 buflen -= ret; 3003 } 3004 3005 /* External data file header extension */ 3006 if (has_data_file(bs) && s->image_data_file) { 3007 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 3008 s->image_data_file, strlen(s->image_data_file), 3009 buflen); 3010 if (ret < 0) { 3011 goto fail; 3012 } 3013 3014 buf += ret; 3015 buflen -= ret; 3016 } 3017 3018 /* Full disk encryption header pointer extension */ 3019 if (s->crypto_header.offset != 0) { 3020 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 3021 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 3022 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 3023 &s->crypto_header, sizeof(s->crypto_header), 3024 buflen); 3025 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 3026 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 3027 if (ret < 0) { 3028 goto fail; 3029 } 3030 buf += ret; 3031 buflen -= ret; 3032 } 3033 3034 /* 3035 * Feature table. A mere 8 feature names occupies 392 bytes, and 3036 * when coupled with the v3 minimum header of 104 bytes plus the 3037 * 8-byte end-of-extension marker, that would leave only 8 bytes 3038 * for a backing file name in an image with 512-byte clusters. 3039 * Thus, we choose to omit this header for cluster sizes 4k and 3040 * smaller. 3041 */ 3042 if (s->qcow_version >= 3 && s->cluster_size > 4096) { 3043 static const Qcow2Feature features[] = { 3044 { 3045 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3046 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 3047 .name = "dirty bit", 3048 }, 3049 { 3050 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3051 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 3052 .name = "corrupt bit", 3053 }, 3054 { 3055 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3056 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 3057 .name = "external data file", 3058 }, 3059 { 3060 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3061 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, 3062 .name = "compression type", 3063 }, 3064 { 3065 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3066 .bit = QCOW2_INCOMPAT_EXTL2_BITNR, 3067 .name = "extended L2 entries", 3068 }, 3069 { 3070 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 3071 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 3072 .name = "lazy refcounts", 3073 }, 3074 { 3075 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3076 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, 3077 .name = "bitmaps", 3078 }, 3079 { 3080 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3081 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 3082 .name = "raw external data", 3083 }, 3084 }; 3085 3086 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 3087 features, sizeof(features), buflen); 3088 if (ret < 0) { 3089 goto fail; 3090 } 3091 buf += ret; 3092 buflen -= ret; 3093 } 3094 3095 /* Bitmap extension */ 3096 if (s->nb_bitmaps > 0) { 3097 Qcow2BitmapHeaderExt bitmaps_header = { 3098 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 3099 .bitmap_directory_size = 3100 cpu_to_be64(s->bitmap_directory_size), 3101 .bitmap_directory_offset = 3102 cpu_to_be64(s->bitmap_directory_offset) 3103 }; 3104 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 3105 &bitmaps_header, sizeof(bitmaps_header), 3106 buflen); 3107 if (ret < 0) { 3108 goto fail; 3109 } 3110 buf += ret; 3111 buflen -= ret; 3112 } 3113 3114 /* Keep unknown header extensions */ 3115 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 3116 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 3117 if (ret < 0) { 3118 goto fail; 3119 } 3120 3121 buf += ret; 3122 buflen -= ret; 3123 } 3124 3125 /* End of header extensions */ 3126 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 3127 if (ret < 0) { 3128 goto fail; 3129 } 3130 3131 buf += ret; 3132 buflen -= ret; 3133 3134 /* Backing file name */ 3135 if (s->image_backing_file) { 3136 size_t backing_file_len = strlen(s->image_backing_file); 3137 3138 if (buflen < backing_file_len) { 3139 ret = -ENOSPC; 3140 goto fail; 3141 } 3142 3143 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 3144 strncpy(buf, s->image_backing_file, buflen); 3145 3146 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 3147 header->backing_file_size = cpu_to_be32(backing_file_len); 3148 } 3149 3150 /* Write the new header */ 3151 ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0); 3152 if (ret < 0) { 3153 goto fail; 3154 } 3155 3156 ret = 0; 3157 fail: 3158 qemu_vfree(header); 3159 return ret; 3160 } 3161 3162 static int coroutine_fn GRAPH_RDLOCK 3163 qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file, 3164 const char *backing_fmt) 3165 { 3166 BDRVQcow2State *s = bs->opaque; 3167 3168 /* Adding a backing file means that the external data file alone won't be 3169 * enough to make sense of the content */ 3170 if (backing_file && data_file_is_raw(bs)) { 3171 return -EINVAL; 3172 } 3173 3174 if (backing_file && strlen(backing_file) > 1023) { 3175 return -EINVAL; 3176 } 3177 3178 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 3179 backing_file ?: ""); 3180 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 3181 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 3182 3183 g_free(s->image_backing_file); 3184 g_free(s->image_backing_format); 3185 3186 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 3187 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 3188 3189 return qcow2_update_header(bs); 3190 } 3191 3192 static int coroutine_fn GRAPH_RDLOCK 3193 qcow2_set_up_encryption(BlockDriverState *bs, 3194 QCryptoBlockCreateOptions *cryptoopts, 3195 Error **errp) 3196 { 3197 BDRVQcow2State *s = bs->opaque; 3198 QCryptoBlock *crypto = NULL; 3199 int fmt, ret; 3200 3201 switch (cryptoopts->format) { 3202 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 3203 fmt = QCOW_CRYPT_LUKS; 3204 break; 3205 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 3206 fmt = QCOW_CRYPT_AES; 3207 break; 3208 default: 3209 error_setg(errp, "Crypto format not supported in qcow2"); 3210 return -EINVAL; 3211 } 3212 3213 s->crypt_method_header = fmt; 3214 3215 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 3216 qcow2_crypto_hdr_init_func, 3217 qcow2_crypto_hdr_write_func, 3218 bs, 0, errp); 3219 if (!crypto) { 3220 return -EINVAL; 3221 } 3222 3223 ret = qcow2_update_header(bs); 3224 if (ret < 0) { 3225 error_setg_errno(errp, -ret, "Could not write encryption header"); 3226 goto out; 3227 } 3228 3229 ret = 0; 3230 out: 3231 qcrypto_block_free(crypto); 3232 return ret; 3233 } 3234 3235 /** 3236 * Preallocates metadata structures for data clusters between @offset (in the 3237 * guest disk) and @new_length (which is thus generally the new guest disk 3238 * size). 3239 * 3240 * Returns: 0 on success, -errno on failure. 3241 */ 3242 static int coroutine_fn GRAPH_RDLOCK 3243 preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length, 3244 PreallocMode mode, Error **errp) 3245 { 3246 BDRVQcow2State *s = bs->opaque; 3247 uint64_t bytes; 3248 uint64_t host_offset = 0; 3249 int64_t file_length; 3250 unsigned int cur_bytes; 3251 int ret; 3252 QCowL2Meta *meta = NULL, *m; 3253 3254 assert(offset <= new_length); 3255 bytes = new_length - offset; 3256 3257 while (bytes) { 3258 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); 3259 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 3260 &host_offset, &meta); 3261 if (ret < 0) { 3262 error_setg_errno(errp, -ret, "Allocating clusters failed"); 3263 goto out; 3264 } 3265 3266 for (m = meta; m != NULL; m = m->next) { 3267 m->prealloc = true; 3268 } 3269 3270 ret = qcow2_handle_l2meta(bs, &meta, true); 3271 if (ret < 0) { 3272 error_setg_errno(errp, -ret, "Mapping clusters failed"); 3273 goto out; 3274 } 3275 3276 /* TODO Preallocate data if requested */ 3277 3278 bytes -= cur_bytes; 3279 offset += cur_bytes; 3280 } 3281 3282 /* 3283 * It is expected that the image file is large enough to actually contain 3284 * all of the allocated clusters (otherwise we get failing reads after 3285 * EOF). Extend the image to the last allocated sector. 3286 */ 3287 file_length = bdrv_co_getlength(s->data_file->bs); 3288 if (file_length < 0) { 3289 error_setg_errno(errp, -file_length, "Could not get file size"); 3290 ret = file_length; 3291 goto out; 3292 } 3293 3294 if (host_offset + cur_bytes > file_length) { 3295 if (mode == PREALLOC_MODE_METADATA) { 3296 mode = PREALLOC_MODE_OFF; 3297 } 3298 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false, 3299 mode, 0, errp); 3300 if (ret < 0) { 3301 goto out; 3302 } 3303 } 3304 3305 ret = 0; 3306 3307 out: 3308 qcow2_handle_l2meta(bs, &meta, false); 3309 return ret; 3310 } 3311 3312 /* qcow2_refcount_metadata_size: 3313 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 3314 * @cluster_size: size of a cluster, in bytes 3315 * @refcount_order: refcount bits power-of-2 exponent 3316 * @generous_increase: allow for the refcount table to be 1.5x as large as it 3317 * needs to be 3318 * 3319 * Returns: Number of bytes required for refcount blocks and table metadata. 3320 */ 3321 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 3322 int refcount_order, bool generous_increase, 3323 uint64_t *refblock_count) 3324 { 3325 /* 3326 * Every host cluster is reference-counted, including metadata (even 3327 * refcount metadata is recursively included). 3328 * 3329 * An accurate formula for the size of refcount metadata size is difficult 3330 * to derive. An easier method of calculation is finding the fixed point 3331 * where no further refcount blocks or table clusters are required to 3332 * reference count every cluster. 3333 */ 3334 int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE; 3335 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 3336 int64_t table = 0; /* number of refcount table clusters */ 3337 int64_t blocks = 0; /* number of refcount block clusters */ 3338 int64_t last; 3339 int64_t n = 0; 3340 3341 do { 3342 last = n; 3343 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 3344 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 3345 n = clusters + blocks + table; 3346 3347 if (n == last && generous_increase) { 3348 clusters += DIV_ROUND_UP(table, 2); 3349 n = 0; /* force another loop */ 3350 generous_increase = false; 3351 } 3352 } while (n != last); 3353 3354 if (refblock_count) { 3355 *refblock_count = blocks; 3356 } 3357 3358 return (blocks + table) * cluster_size; 3359 } 3360 3361 /** 3362 * qcow2_calc_prealloc_size: 3363 * @total_size: virtual disk size in bytes 3364 * @cluster_size: cluster size in bytes 3365 * @refcount_order: refcount bits power-of-2 exponent 3366 * @extended_l2: true if the image has extended L2 entries 3367 * 3368 * Returns: Total number of bytes required for the fully allocated image 3369 * (including metadata). 3370 */ 3371 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 3372 size_t cluster_size, 3373 int refcount_order, 3374 bool extended_l2) 3375 { 3376 int64_t meta_size = 0; 3377 uint64_t nl1e, nl2e; 3378 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 3379 size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 3380 3381 /* header: 1 cluster */ 3382 meta_size += cluster_size; 3383 3384 /* total size of L2 tables */ 3385 nl2e = aligned_total_size / cluster_size; 3386 nl2e = ROUND_UP(nl2e, cluster_size / l2e_size); 3387 meta_size += nl2e * l2e_size; 3388 3389 /* total size of L1 tables */ 3390 nl1e = nl2e * l2e_size / cluster_size; 3391 nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE); 3392 meta_size += nl1e * L1E_SIZE; 3393 3394 /* total size of refcount table and blocks */ 3395 meta_size += qcow2_refcount_metadata_size( 3396 (meta_size + aligned_total_size) / cluster_size, 3397 cluster_size, refcount_order, false, NULL); 3398 3399 return meta_size + aligned_total_size; 3400 } 3401 3402 static bool validate_cluster_size(size_t cluster_size, bool extended_l2, 3403 Error **errp) 3404 { 3405 int cluster_bits = ctz32(cluster_size); 3406 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 3407 (1 << cluster_bits) != cluster_size) 3408 { 3409 error_setg(errp, "Cluster size must be a power of two between %d and " 3410 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 3411 return false; 3412 } 3413 3414 if (extended_l2) { 3415 unsigned min_cluster_size = 3416 (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER; 3417 if (cluster_size < min_cluster_size) { 3418 error_setg(errp, "Extended L2 entries are only supported with " 3419 "cluster sizes of at least %u bytes", min_cluster_size); 3420 return false; 3421 } 3422 } 3423 3424 return true; 3425 } 3426 3427 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2, 3428 Error **errp) 3429 { 3430 size_t cluster_size; 3431 3432 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 3433 DEFAULT_CLUSTER_SIZE); 3434 if (!validate_cluster_size(cluster_size, extended_l2, errp)) { 3435 return 0; 3436 } 3437 return cluster_size; 3438 } 3439 3440 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 3441 { 3442 char *buf; 3443 int ret; 3444 3445 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 3446 if (!buf) { 3447 ret = 3; /* default */ 3448 } else if (!strcmp(buf, "0.10")) { 3449 ret = 2; 3450 } else if (!strcmp(buf, "1.1")) { 3451 ret = 3; 3452 } else { 3453 error_setg(errp, "Invalid compatibility level: '%s'", buf); 3454 ret = -EINVAL; 3455 } 3456 g_free(buf); 3457 return ret; 3458 } 3459 3460 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 3461 Error **errp) 3462 { 3463 uint64_t refcount_bits; 3464 3465 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 3466 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 3467 error_setg(errp, "Refcount width must be a power of two and may not " 3468 "exceed 64 bits"); 3469 return 0; 3470 } 3471 3472 if (version < 3 && refcount_bits != 16) { 3473 error_setg(errp, "Different refcount widths than 16 bits require " 3474 "compatibility level 1.1 or above (use compat=1.1 or " 3475 "greater)"); 3476 return 0; 3477 } 3478 3479 return refcount_bits; 3480 } 3481 3482 static int coroutine_fn GRAPH_UNLOCKED 3483 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 3484 { 3485 ERRP_GUARD(); 3486 BlockdevCreateOptionsQcow2 *qcow2_opts; 3487 QDict *options; 3488 3489 /* 3490 * Open the image file and write a minimal qcow2 header. 3491 * 3492 * We keep things simple and start with a zero-sized image. We also 3493 * do without refcount blocks or a L1 table for now. We'll fix the 3494 * inconsistency later. 3495 * 3496 * We do need a refcount table because growing the refcount table means 3497 * allocating two new refcount blocks - the second of which would be at 3498 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 3499 * size for any qcow2 image. 3500 */ 3501 BlockBackend *blk = NULL; 3502 BlockDriverState *bs = NULL; 3503 BlockDriverState *data_bs = NULL; 3504 QCowHeader *header; 3505 size_t cluster_size; 3506 int version; 3507 int refcount_order; 3508 uint64_t *refcount_table; 3509 int ret; 3510 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 3511 3512 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 3513 qcow2_opts = &create_options->u.qcow2; 3514 3515 bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp); 3516 if (bs == NULL) { 3517 return -EIO; 3518 } 3519 3520 /* Validate options and set default values */ 3521 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 3522 error_setg(errp, "Image size must be a multiple of %u bytes", 3523 (unsigned) BDRV_SECTOR_SIZE); 3524 ret = -EINVAL; 3525 goto out; 3526 } 3527 3528 if (qcow2_opts->has_version) { 3529 switch (qcow2_opts->version) { 3530 case BLOCKDEV_QCOW2_VERSION_V2: 3531 version = 2; 3532 break; 3533 case BLOCKDEV_QCOW2_VERSION_V3: 3534 version = 3; 3535 break; 3536 default: 3537 g_assert_not_reached(); 3538 } 3539 } else { 3540 version = 3; 3541 } 3542 3543 if (qcow2_opts->has_cluster_size) { 3544 cluster_size = qcow2_opts->cluster_size; 3545 } else { 3546 cluster_size = DEFAULT_CLUSTER_SIZE; 3547 } 3548 3549 if (!qcow2_opts->has_extended_l2) { 3550 qcow2_opts->extended_l2 = false; 3551 } 3552 if (qcow2_opts->extended_l2) { 3553 if (version < 3) { 3554 error_setg(errp, "Extended L2 entries are only supported with " 3555 "compatibility level 1.1 and above (use version=v3 or " 3556 "greater)"); 3557 ret = -EINVAL; 3558 goto out; 3559 } 3560 } 3561 3562 if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) { 3563 ret = -EINVAL; 3564 goto out; 3565 } 3566 3567 if (!qcow2_opts->has_preallocation) { 3568 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3569 } 3570 if (qcow2_opts->backing_file && 3571 qcow2_opts->preallocation != PREALLOC_MODE_OFF && 3572 !qcow2_opts->extended_l2) 3573 { 3574 error_setg(errp, "Backing file and preallocation can only be used at " 3575 "the same time if extended_l2 is on"); 3576 ret = -EINVAL; 3577 goto out; 3578 } 3579 if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) { 3580 error_setg(errp, "Backing format cannot be used without backing file"); 3581 ret = -EINVAL; 3582 goto out; 3583 } 3584 3585 if (!qcow2_opts->has_lazy_refcounts) { 3586 qcow2_opts->lazy_refcounts = false; 3587 } 3588 if (version < 3 && qcow2_opts->lazy_refcounts) { 3589 error_setg(errp, "Lazy refcounts only supported with compatibility " 3590 "level 1.1 and above (use version=v3 or greater)"); 3591 ret = -EINVAL; 3592 goto out; 3593 } 3594 3595 if (!qcow2_opts->has_refcount_bits) { 3596 qcow2_opts->refcount_bits = 16; 3597 } 3598 if (qcow2_opts->refcount_bits > 64 || 3599 !is_power_of_2(qcow2_opts->refcount_bits)) 3600 { 3601 error_setg(errp, "Refcount width must be a power of two and may not " 3602 "exceed 64 bits"); 3603 ret = -EINVAL; 3604 goto out; 3605 } 3606 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3607 error_setg(errp, "Different refcount widths than 16 bits require " 3608 "compatibility level 1.1 or above (use version=v3 or " 3609 "greater)"); 3610 ret = -EINVAL; 3611 goto out; 3612 } 3613 refcount_order = ctz32(qcow2_opts->refcount_bits); 3614 3615 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3616 error_setg(errp, "data-file-raw requires data-file"); 3617 ret = -EINVAL; 3618 goto out; 3619 } 3620 if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) { 3621 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3622 "the same time"); 3623 ret = -EINVAL; 3624 goto out; 3625 } 3626 if (qcow2_opts->data_file_raw && 3627 qcow2_opts->preallocation == PREALLOC_MODE_OFF) 3628 { 3629 /* 3630 * data-file-raw means that "the external data file can be 3631 * read as a consistent standalone raw image without looking 3632 * at the qcow2 metadata." It does not say that the metadata 3633 * must be ignored, though (and the qcow2 driver in fact does 3634 * not ignore it), so the L1/L2 tables must be present and 3635 * give a 1:1 mapping, so you get the same result regardless 3636 * of whether you look at the metadata or whether you ignore 3637 * it. 3638 */ 3639 qcow2_opts->preallocation = PREALLOC_MODE_METADATA; 3640 3641 /* 3642 * Cannot use preallocation with backing files, but giving a 3643 * backing file when specifying data_file_raw is an error 3644 * anyway. 3645 */ 3646 assert(!qcow2_opts->backing_file); 3647 } 3648 3649 if (qcow2_opts->data_file) { 3650 if (version < 3) { 3651 error_setg(errp, "External data files are only supported with " 3652 "compatibility level 1.1 and above (use version=v3 or " 3653 "greater)"); 3654 ret = -EINVAL; 3655 goto out; 3656 } 3657 data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp); 3658 if (data_bs == NULL) { 3659 ret = -EIO; 3660 goto out; 3661 } 3662 } 3663 3664 if (qcow2_opts->has_compression_type && 3665 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3666 3667 ret = -EINVAL; 3668 3669 if (version < 3) { 3670 error_setg(errp, "Non-zlib compression type is only supported with " 3671 "compatibility level 1.1 and above (use version=v3 or " 3672 "greater)"); 3673 goto out; 3674 } 3675 3676 switch (qcow2_opts->compression_type) { 3677 #ifdef CONFIG_ZSTD 3678 case QCOW2_COMPRESSION_TYPE_ZSTD: 3679 break; 3680 #endif 3681 default: 3682 error_setg(errp, "Unknown compression type"); 3683 goto out; 3684 } 3685 3686 compression_type = qcow2_opts->compression_type; 3687 } 3688 3689 /* Create BlockBackend to write to the image */ 3690 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 3691 errp); 3692 if (!blk) { 3693 ret = -EPERM; 3694 goto out; 3695 } 3696 blk_set_allow_write_beyond_eof(blk, true); 3697 3698 /* Write the header */ 3699 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3700 header = g_malloc0(cluster_size); 3701 *header = (QCowHeader) { 3702 .magic = cpu_to_be32(QCOW_MAGIC), 3703 .version = cpu_to_be32(version), 3704 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3705 .size = cpu_to_be64(0), 3706 .l1_table_offset = cpu_to_be64(0), 3707 .l1_size = cpu_to_be32(0), 3708 .refcount_table_offset = cpu_to_be64(cluster_size), 3709 .refcount_table_clusters = cpu_to_be32(1), 3710 .refcount_order = cpu_to_be32(refcount_order), 3711 /* don't deal with endianness since compression_type is 1 byte long */ 3712 .compression_type = compression_type, 3713 .header_length = cpu_to_be32(sizeof(*header)), 3714 }; 3715 3716 /* We'll update this to correct value later */ 3717 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3718 3719 if (qcow2_opts->lazy_refcounts) { 3720 header->compatible_features |= 3721 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3722 } 3723 if (data_bs) { 3724 header->incompatible_features |= 3725 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3726 } 3727 if (qcow2_opts->data_file_raw) { 3728 header->autoclear_features |= 3729 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3730 } 3731 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3732 header->incompatible_features |= 3733 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); 3734 } 3735 3736 if (qcow2_opts->extended_l2) { 3737 header->incompatible_features |= 3738 cpu_to_be64(QCOW2_INCOMPAT_EXTL2); 3739 } 3740 3741 ret = blk_co_pwrite(blk, 0, cluster_size, header, 0); 3742 g_free(header); 3743 if (ret < 0) { 3744 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3745 goto out; 3746 } 3747 3748 /* Write a refcount table with one refcount block */ 3749 refcount_table = g_malloc0(2 * cluster_size); 3750 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3751 ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0); 3752 g_free(refcount_table); 3753 3754 if (ret < 0) { 3755 error_setg_errno(errp, -ret, "Could not write refcount table"); 3756 goto out; 3757 } 3758 3759 blk_co_unref(blk); 3760 blk = NULL; 3761 3762 /* 3763 * And now open the image and make it consistent first (i.e. increase the 3764 * refcount of the cluster that is occupied by the header and the refcount 3765 * table) 3766 */ 3767 options = qdict_new(); 3768 qdict_put_str(options, "driver", "qcow2"); 3769 qdict_put_str(options, "file", bs->node_name); 3770 if (data_bs) { 3771 qdict_put_str(options, "data-file", data_bs->node_name); 3772 } 3773 blk = blk_co_new_open(NULL, NULL, options, 3774 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3775 errp); 3776 if (blk == NULL) { 3777 ret = -EIO; 3778 goto out; 3779 } 3780 3781 bdrv_graph_co_rdlock(); 3782 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3783 if (ret < 0) { 3784 bdrv_graph_co_rdunlock(); 3785 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3786 "header and refcount table"); 3787 goto out; 3788 3789 } else if (ret != 0) { 3790 error_report("Huh, first cluster in empty image is already in use?"); 3791 abort(); 3792 } 3793 3794 /* Set the external data file if necessary */ 3795 if (data_bs) { 3796 BDRVQcow2State *s = blk_bs(blk)->opaque; 3797 s->image_data_file = g_strdup(data_bs->filename); 3798 } 3799 3800 /* Create a full header (including things like feature table) */ 3801 ret = qcow2_update_header(blk_bs(blk)); 3802 bdrv_graph_co_rdunlock(); 3803 3804 if (ret < 0) { 3805 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3806 goto out; 3807 } 3808 3809 /* Okay, now that we have a valid image, let's give it the right size */ 3810 ret = blk_co_truncate(blk, qcow2_opts->size, false, 3811 qcow2_opts->preallocation, 0, errp); 3812 if (ret < 0) { 3813 error_prepend(errp, "Could not resize image: "); 3814 goto out; 3815 } 3816 3817 /* Want a backing file? There you go. */ 3818 if (qcow2_opts->backing_file) { 3819 const char *backing_format = NULL; 3820 3821 if (qcow2_opts->has_backing_fmt) { 3822 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3823 } 3824 3825 bdrv_graph_co_rdlock(); 3826 ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3827 backing_format, false); 3828 bdrv_graph_co_rdunlock(); 3829 3830 if (ret < 0) { 3831 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3832 "with format '%s'", qcow2_opts->backing_file, 3833 backing_format); 3834 goto out; 3835 } 3836 } 3837 3838 /* Want encryption? There you go. */ 3839 if (qcow2_opts->encrypt) { 3840 bdrv_graph_co_rdlock(); 3841 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3842 bdrv_graph_co_rdunlock(); 3843 3844 if (ret < 0) { 3845 goto out; 3846 } 3847 } 3848 3849 blk_co_unref(blk); 3850 blk = NULL; 3851 3852 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3853 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3854 * have to setup decryption context. We're not doing any I/O on the top 3855 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3856 * not have effect. 3857 */ 3858 options = qdict_new(); 3859 qdict_put_str(options, "driver", "qcow2"); 3860 qdict_put_str(options, "file", bs->node_name); 3861 if (data_bs) { 3862 qdict_put_str(options, "data-file", data_bs->node_name); 3863 } 3864 blk = blk_co_new_open(NULL, NULL, options, 3865 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3866 errp); 3867 if (blk == NULL) { 3868 ret = -EIO; 3869 goto out; 3870 } 3871 3872 ret = 0; 3873 out: 3874 blk_co_unref(blk); 3875 bdrv_co_unref(bs); 3876 bdrv_co_unref(data_bs); 3877 return ret; 3878 } 3879 3880 static int coroutine_fn GRAPH_UNLOCKED 3881 qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, 3882 Error **errp) 3883 { 3884 BlockdevCreateOptions *create_options = NULL; 3885 QDict *qdict; 3886 Visitor *v; 3887 BlockDriverState *bs = NULL; 3888 BlockDriverState *data_bs = NULL; 3889 const char *val; 3890 int ret; 3891 3892 /* Only the keyval visitor supports the dotted syntax needed for 3893 * encryption, so go through a QDict before getting a QAPI type. Ignore 3894 * options meant for the protocol layer so that the visitor doesn't 3895 * complain. */ 3896 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3897 true); 3898 3899 /* Handle encryption options */ 3900 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3901 if (val && !strcmp(val, "on")) { 3902 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3903 } else if (val && !strcmp(val, "off")) { 3904 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3905 } 3906 3907 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3908 if (val && !strcmp(val, "aes")) { 3909 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3910 } 3911 3912 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3913 * version=v2/v3 below. */ 3914 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3915 if (val && !strcmp(val, "0.10")) { 3916 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3917 } else if (val && !strcmp(val, "1.1")) { 3918 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3919 } 3920 3921 /* Change legacy command line options into QMP ones */ 3922 static const QDictRenames opt_renames[] = { 3923 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3924 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3925 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3926 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3927 { BLOCK_OPT_EXTL2, "extended-l2" }, 3928 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3929 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3930 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3931 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3932 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, 3933 { NULL, NULL }, 3934 }; 3935 3936 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3937 ret = -EINVAL; 3938 goto finish; 3939 } 3940 3941 /* Create and open the file (protocol layer) */ 3942 ret = bdrv_co_create_file(filename, opts, errp); 3943 if (ret < 0) { 3944 goto finish; 3945 } 3946 3947 bs = bdrv_co_open(filename, NULL, NULL, 3948 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3949 if (bs == NULL) { 3950 ret = -EIO; 3951 goto finish; 3952 } 3953 3954 /* Create and open an external data file (protocol layer) */ 3955 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3956 if (val) { 3957 ret = bdrv_co_create_file(val, opts, errp); 3958 if (ret < 0) { 3959 goto finish; 3960 } 3961 3962 data_bs = bdrv_co_open(val, NULL, NULL, 3963 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3964 errp); 3965 if (data_bs == NULL) { 3966 ret = -EIO; 3967 goto finish; 3968 } 3969 3970 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3971 qdict_put_str(qdict, "data-file", data_bs->node_name); 3972 } 3973 3974 /* Set 'driver' and 'node' options */ 3975 qdict_put_str(qdict, "driver", "qcow2"); 3976 qdict_put_str(qdict, "file", bs->node_name); 3977 3978 /* Now get the QAPI type BlockdevCreateOptions */ 3979 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3980 if (!v) { 3981 ret = -EINVAL; 3982 goto finish; 3983 } 3984 3985 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 3986 visit_free(v); 3987 if (!create_options) { 3988 ret = -EINVAL; 3989 goto finish; 3990 } 3991 3992 /* Silently round up size */ 3993 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 3994 BDRV_SECTOR_SIZE); 3995 3996 /* Create the qcow2 image (format layer) */ 3997 ret = qcow2_co_create(create_options, errp); 3998 finish: 3999 if (ret < 0) { 4000 bdrv_graph_co_rdlock(); 4001 bdrv_co_delete_file_noerr(bs); 4002 bdrv_co_delete_file_noerr(data_bs); 4003 bdrv_graph_co_rdunlock(); 4004 } else { 4005 ret = 0; 4006 } 4007 4008 qobject_unref(qdict); 4009 bdrv_co_unref(bs); 4010 bdrv_co_unref(data_bs); 4011 qapi_free_BlockdevCreateOptions(create_options); 4012 return ret; 4013 } 4014 4015 4016 static bool coroutine_fn GRAPH_RDLOCK 4017 is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 4018 { 4019 int64_t nr; 4020 int res; 4021 4022 /* Clamp to image length, before checking status of underlying sectors */ 4023 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 4024 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 4025 } 4026 4027 if (!bytes) { 4028 return true; 4029 } 4030 4031 /* 4032 * bdrv_block_status_above doesn't merge different types of zeros, for 4033 * example, zeros which come from the region which is unallocated in 4034 * the whole backing chain, and zeros which come because of a short 4035 * backing file. So, we need a loop. 4036 */ 4037 do { 4038 res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 4039 offset += nr; 4040 bytes -= nr; 4041 } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes); 4042 4043 return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0; 4044 } 4045 4046 static int coroutine_fn GRAPH_RDLOCK 4047 qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 4048 BdrvRequestFlags flags) 4049 { 4050 int ret; 4051 BDRVQcow2State *s = bs->opaque; 4052 4053 uint32_t head = offset_into_subcluster(s, offset); 4054 uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) - 4055 (offset + bytes); 4056 4057 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 4058 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 4059 tail = 0; 4060 } 4061 4062 if (head || tail) { 4063 uint64_t off; 4064 unsigned int nr; 4065 QCow2SubclusterType type; 4066 4067 assert(head + bytes + tail <= s->subcluster_size); 4068 4069 /* check whether remainder of cluster already reads as zero */ 4070 if (!(is_zero(bs, offset - head, head) && 4071 is_zero(bs, offset + bytes, tail))) { 4072 return -ENOTSUP; 4073 } 4074 4075 qemu_co_mutex_lock(&s->lock); 4076 /* We can have new write after previous check */ 4077 offset -= head; 4078 bytes = s->subcluster_size; 4079 nr = s->subcluster_size; 4080 ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type); 4081 if (ret < 0 || 4082 (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 4083 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && 4084 type != QCOW2_SUBCLUSTER_ZERO_PLAIN && 4085 type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) { 4086 qemu_co_mutex_unlock(&s->lock); 4087 return ret < 0 ? ret : -ENOTSUP; 4088 } 4089 } else { 4090 qemu_co_mutex_lock(&s->lock); 4091 } 4092 4093 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 4094 4095 /* Whatever is left can use real zero subclusters */ 4096 ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags); 4097 qemu_co_mutex_unlock(&s->lock); 4098 4099 return ret; 4100 } 4101 4102 static int coroutine_fn GRAPH_RDLOCK 4103 qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 4104 { 4105 int ret; 4106 BDRVQcow2State *s = bs->opaque; 4107 4108 /* If the image does not support QCOW_OFLAG_ZERO then discarding 4109 * clusters could expose stale data from the backing file. */ 4110 if (s->qcow_version < 3 && bs->backing) { 4111 return -ENOTSUP; 4112 } 4113 4114 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 4115 assert(bytes < s->cluster_size); 4116 /* Ignore partial clusters, except for the special case of the 4117 * complete partial cluster at the end of an unaligned file */ 4118 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 4119 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 4120 return -ENOTSUP; 4121 } 4122 } 4123 4124 qemu_co_mutex_lock(&s->lock); 4125 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 4126 false); 4127 qemu_co_mutex_unlock(&s->lock); 4128 return ret; 4129 } 4130 4131 static int coroutine_fn GRAPH_RDLOCK 4132 qcow2_co_copy_range_from(BlockDriverState *bs, 4133 BdrvChild *src, int64_t src_offset, 4134 BdrvChild *dst, int64_t dst_offset, 4135 int64_t bytes, BdrvRequestFlags read_flags, 4136 BdrvRequestFlags write_flags) 4137 { 4138 BDRVQcow2State *s = bs->opaque; 4139 int ret; 4140 unsigned int cur_bytes; /* number of bytes in current iteration */ 4141 BdrvChild *child = NULL; 4142 BdrvRequestFlags cur_write_flags; 4143 4144 assert(!bs->encrypted); 4145 qemu_co_mutex_lock(&s->lock); 4146 4147 while (bytes != 0) { 4148 uint64_t copy_offset = 0; 4149 QCow2SubclusterType type; 4150 /* prepare next request */ 4151 cur_bytes = MIN(bytes, INT_MAX); 4152 cur_write_flags = write_flags; 4153 4154 ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes, 4155 ©_offset, &type); 4156 if (ret < 0) { 4157 goto out; 4158 } 4159 4160 switch (type) { 4161 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 4162 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 4163 if (bs->backing && bs->backing->bs) { 4164 int64_t backing_length = bdrv_co_getlength(bs->backing->bs); 4165 if (src_offset >= backing_length) { 4166 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4167 } else { 4168 child = bs->backing; 4169 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 4170 copy_offset = src_offset; 4171 } 4172 } else { 4173 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4174 } 4175 break; 4176 4177 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 4178 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 4179 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4180 break; 4181 4182 case QCOW2_SUBCLUSTER_COMPRESSED: 4183 ret = -ENOTSUP; 4184 goto out; 4185 4186 case QCOW2_SUBCLUSTER_NORMAL: 4187 child = s->data_file; 4188 break; 4189 4190 default: 4191 abort(); 4192 } 4193 qemu_co_mutex_unlock(&s->lock); 4194 ret = bdrv_co_copy_range_from(child, 4195 copy_offset, 4196 dst, dst_offset, 4197 cur_bytes, read_flags, cur_write_flags); 4198 qemu_co_mutex_lock(&s->lock); 4199 if (ret < 0) { 4200 goto out; 4201 } 4202 4203 bytes -= cur_bytes; 4204 src_offset += cur_bytes; 4205 dst_offset += cur_bytes; 4206 } 4207 ret = 0; 4208 4209 out: 4210 qemu_co_mutex_unlock(&s->lock); 4211 return ret; 4212 } 4213 4214 static int coroutine_fn GRAPH_RDLOCK 4215 qcow2_co_copy_range_to(BlockDriverState *bs, 4216 BdrvChild *src, int64_t src_offset, 4217 BdrvChild *dst, int64_t dst_offset, 4218 int64_t bytes, BdrvRequestFlags read_flags, 4219 BdrvRequestFlags write_flags) 4220 { 4221 BDRVQcow2State *s = bs->opaque; 4222 int ret; 4223 unsigned int cur_bytes; /* number of sectors in current iteration */ 4224 uint64_t host_offset; 4225 QCowL2Meta *l2meta = NULL; 4226 4227 assert(!bs->encrypted); 4228 4229 qemu_co_mutex_lock(&s->lock); 4230 4231 while (bytes != 0) { 4232 4233 l2meta = NULL; 4234 4235 cur_bytes = MIN(bytes, INT_MAX); 4236 4237 /* TODO: 4238 * If src->bs == dst->bs, we could simply copy by incrementing 4239 * the refcnt, without copying user data. 4240 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 4241 ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes, 4242 &host_offset, &l2meta); 4243 if (ret < 0) { 4244 goto fail; 4245 } 4246 4247 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes, 4248 true); 4249 if (ret < 0) { 4250 goto fail; 4251 } 4252 4253 qemu_co_mutex_unlock(&s->lock); 4254 ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset, 4255 cur_bytes, read_flags, write_flags); 4256 qemu_co_mutex_lock(&s->lock); 4257 if (ret < 0) { 4258 goto fail; 4259 } 4260 4261 ret = qcow2_handle_l2meta(bs, &l2meta, true); 4262 if (ret) { 4263 goto fail; 4264 } 4265 4266 bytes -= cur_bytes; 4267 src_offset += cur_bytes; 4268 dst_offset += cur_bytes; 4269 } 4270 ret = 0; 4271 4272 fail: 4273 qcow2_handle_l2meta(bs, &l2meta, false); 4274 4275 qemu_co_mutex_unlock(&s->lock); 4276 4277 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 4278 4279 return ret; 4280 } 4281 4282 static int coroutine_fn GRAPH_RDLOCK 4283 qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, 4284 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) 4285 { 4286 ERRP_GUARD(); 4287 BDRVQcow2State *s = bs->opaque; 4288 uint64_t old_length; 4289 int64_t new_l1_size; 4290 int ret; 4291 QDict *options; 4292 4293 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 4294 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 4295 { 4296 error_setg(errp, "Unsupported preallocation mode '%s'", 4297 PreallocMode_str(prealloc)); 4298 return -ENOTSUP; 4299 } 4300 4301 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) { 4302 error_setg(errp, "The new size must be a multiple of %u", 4303 (unsigned) BDRV_SECTOR_SIZE); 4304 return -EINVAL; 4305 } 4306 4307 qemu_co_mutex_lock(&s->lock); 4308 4309 /* 4310 * Even though we store snapshot size for all images, it was not 4311 * required until v3, so it is not safe to proceed for v2. 4312 */ 4313 if (s->nb_snapshots && s->qcow_version < 3) { 4314 error_setg(errp, "Can't resize a v2 image which has snapshots"); 4315 ret = -ENOTSUP; 4316 goto fail; 4317 } 4318 4319 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */ 4320 if (qcow2_truncate_bitmaps_check(bs, errp)) { 4321 ret = -ENOTSUP; 4322 goto fail; 4323 } 4324 4325 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 4326 new_l1_size = size_to_l1(s, offset); 4327 4328 if (offset < old_length) { 4329 int64_t last_cluster, old_file_size; 4330 if (prealloc != PREALLOC_MODE_OFF) { 4331 error_setg(errp, 4332 "Preallocation can't be used for shrinking an image"); 4333 ret = -EINVAL; 4334 goto fail; 4335 } 4336 4337 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 4338 old_length - ROUND_UP(offset, 4339 s->cluster_size), 4340 QCOW2_DISCARD_ALWAYS, true); 4341 if (ret < 0) { 4342 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 4343 goto fail; 4344 } 4345 4346 ret = qcow2_shrink_l1_table(bs, new_l1_size); 4347 if (ret < 0) { 4348 error_setg_errno(errp, -ret, 4349 "Failed to reduce the number of L2 tables"); 4350 goto fail; 4351 } 4352 4353 ret = qcow2_shrink_reftable(bs); 4354 if (ret < 0) { 4355 error_setg_errno(errp, -ret, 4356 "Failed to discard unused refblocks"); 4357 goto fail; 4358 } 4359 4360 old_file_size = bdrv_co_getlength(bs->file->bs); 4361 if (old_file_size < 0) { 4362 error_setg_errno(errp, -old_file_size, 4363 "Failed to inquire current file length"); 4364 ret = old_file_size; 4365 goto fail; 4366 } 4367 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4368 if (last_cluster < 0) { 4369 error_setg_errno(errp, -last_cluster, 4370 "Failed to find the last cluster"); 4371 ret = last_cluster; 4372 goto fail; 4373 } 4374 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 4375 Error *local_err = NULL; 4376 4377 /* 4378 * Do not pass @exact here: It will not help the user if 4379 * we get an error here just because they wanted to shrink 4380 * their qcow2 image (on a block device) with qemu-img. 4381 * (And on the qcow2 layer, the @exact requirement is 4382 * always fulfilled, so there is no need to pass it on.) 4383 */ 4384 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 4385 false, PREALLOC_MODE_OFF, 0, &local_err); 4386 if (local_err) { 4387 warn_reportf_err(local_err, 4388 "Failed to truncate the tail of the image: "); 4389 } 4390 } 4391 } else { 4392 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 4393 if (ret < 0) { 4394 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 4395 goto fail; 4396 } 4397 4398 if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) { 4399 /* 4400 * When creating a qcow2 image with data-file-raw, we enforce 4401 * at least prealloc=metadata, so that the L1/L2 tables are 4402 * fully allocated and reading from the data file will return 4403 * the same data as reading from the qcow2 image. When the 4404 * image is grown, we must consequently preallocate the 4405 * metadata structures to cover the added area. 4406 */ 4407 prealloc = PREALLOC_MODE_METADATA; 4408 } 4409 } 4410 4411 switch (prealloc) { 4412 case PREALLOC_MODE_OFF: 4413 if (has_data_file(bs)) { 4414 /* 4415 * If the caller wants an exact resize, the external data 4416 * file should be resized to the exact target size, too, 4417 * so we pass @exact here. 4418 */ 4419 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0, 4420 errp); 4421 if (ret < 0) { 4422 goto fail; 4423 } 4424 } 4425 break; 4426 4427 case PREALLOC_MODE_METADATA: 4428 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4429 if (ret < 0) { 4430 goto fail; 4431 } 4432 break; 4433 4434 case PREALLOC_MODE_FALLOC: 4435 case PREALLOC_MODE_FULL: 4436 { 4437 int64_t allocation_start, host_offset, guest_offset; 4438 int64_t clusters_allocated; 4439 int64_t old_file_size, last_cluster, new_file_size; 4440 uint64_t nb_new_data_clusters, nb_new_l2_tables; 4441 bool subclusters_need_allocation = false; 4442 4443 /* With a data file, preallocation means just allocating the metadata 4444 * and forwarding the truncate request to the data file */ 4445 if (has_data_file(bs)) { 4446 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4447 if (ret < 0) { 4448 goto fail; 4449 } 4450 break; 4451 } 4452 4453 old_file_size = bdrv_co_getlength(bs->file->bs); 4454 if (old_file_size < 0) { 4455 error_setg_errno(errp, -old_file_size, 4456 "Failed to inquire current file length"); 4457 ret = old_file_size; 4458 goto fail; 4459 } 4460 4461 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4462 if (last_cluster >= 0) { 4463 old_file_size = (last_cluster + 1) * s->cluster_size; 4464 } else { 4465 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 4466 } 4467 4468 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) - 4469 start_of_cluster(s, old_length)) >> s->cluster_bits; 4470 4471 /* This is an overestimation; we will not actually allocate space for 4472 * these in the file but just make sure the new refcount structures are 4473 * able to cover them so we will not have to allocate new refblocks 4474 * while entering the data blocks in the potentially new L2 tables. 4475 * (We do not actually care where the L2 tables are placed. Maybe they 4476 * are already allocated or they can be placed somewhere before 4477 * @old_file_size. It does not matter because they will be fully 4478 * allocated automatically, so they do not need to be covered by the 4479 * preallocation. All that matters is that we will not have to allocate 4480 * new refcount structures for them.) */ 4481 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 4482 s->cluster_size / l2_entry_size(s)); 4483 /* The cluster range may not be aligned to L2 boundaries, so add one L2 4484 * table for a potential head/tail */ 4485 nb_new_l2_tables++; 4486 4487 allocation_start = qcow2_refcount_area(bs, old_file_size, 4488 nb_new_data_clusters + 4489 nb_new_l2_tables, 4490 true, 0, 0); 4491 if (allocation_start < 0) { 4492 error_setg_errno(errp, -allocation_start, 4493 "Failed to resize refcount structures"); 4494 ret = allocation_start; 4495 goto fail; 4496 } 4497 4498 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 4499 nb_new_data_clusters); 4500 if (clusters_allocated < 0) { 4501 error_setg_errno(errp, -clusters_allocated, 4502 "Failed to allocate data clusters"); 4503 ret = clusters_allocated; 4504 goto fail; 4505 } 4506 4507 assert(clusters_allocated == nb_new_data_clusters); 4508 4509 /* Allocate the data area */ 4510 new_file_size = allocation_start + 4511 nb_new_data_clusters * s->cluster_size; 4512 /* 4513 * Image file grows, so @exact does not matter. 4514 * 4515 * If we need to zero out the new area, try first whether the protocol 4516 * driver can already take care of this. 4517 */ 4518 if (flags & BDRV_REQ_ZERO_WRITE) { 4519 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 4520 BDRV_REQ_ZERO_WRITE, NULL); 4521 if (ret >= 0) { 4522 flags &= ~BDRV_REQ_ZERO_WRITE; 4523 /* Ensure that we read zeroes and not backing file data */ 4524 subclusters_need_allocation = true; 4525 } 4526 } else { 4527 ret = -1; 4528 } 4529 if (ret < 0) { 4530 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0, 4531 errp); 4532 } 4533 if (ret < 0) { 4534 error_prepend(errp, "Failed to resize underlying file: "); 4535 qcow2_free_clusters(bs, allocation_start, 4536 nb_new_data_clusters * s->cluster_size, 4537 QCOW2_DISCARD_OTHER); 4538 goto fail; 4539 } 4540 4541 /* Create the necessary L2 entries */ 4542 host_offset = allocation_start; 4543 guest_offset = old_length; 4544 while (nb_new_data_clusters) { 4545 int64_t nb_clusters = MIN( 4546 nb_new_data_clusters, 4547 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 4548 unsigned cow_start_length = offset_into_cluster(s, guest_offset); 4549 QCowL2Meta allocation; 4550 guest_offset = start_of_cluster(s, guest_offset); 4551 allocation = (QCowL2Meta) { 4552 .offset = guest_offset, 4553 .alloc_offset = host_offset, 4554 .nb_clusters = nb_clusters, 4555 .cow_start = { 4556 .offset = 0, 4557 .nb_bytes = cow_start_length, 4558 }, 4559 .cow_end = { 4560 .offset = nb_clusters << s->cluster_bits, 4561 .nb_bytes = 0, 4562 }, 4563 .prealloc = !subclusters_need_allocation, 4564 }; 4565 qemu_co_queue_init(&allocation.dependent_requests); 4566 4567 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 4568 if (ret < 0) { 4569 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 4570 qcow2_free_clusters(bs, host_offset, 4571 nb_new_data_clusters * s->cluster_size, 4572 QCOW2_DISCARD_OTHER); 4573 goto fail; 4574 } 4575 4576 guest_offset += nb_clusters * s->cluster_size; 4577 host_offset += nb_clusters * s->cluster_size; 4578 nb_new_data_clusters -= nb_clusters; 4579 } 4580 break; 4581 } 4582 4583 default: 4584 g_assert_not_reached(); 4585 } 4586 4587 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { 4588 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size); 4589 4590 /* 4591 * Use zero clusters as much as we can. qcow2_subcluster_zeroize() 4592 * requires a subcluster-aligned start. The end may be unaligned if 4593 * it is at the end of the image (which it is here). 4594 */ 4595 if (offset > zero_start) { 4596 ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start, 4597 0); 4598 if (ret < 0) { 4599 error_setg_errno(errp, -ret, "Failed to zero out new clusters"); 4600 goto fail; 4601 } 4602 } 4603 4604 /* Write explicit zeros for the unaligned head */ 4605 if (zero_start > old_length) { 4606 uint64_t len = MIN(zero_start, offset) - old_length; 4607 uint8_t *buf = qemu_blockalign0(bs, len); 4608 QEMUIOVector qiov; 4609 qemu_iovec_init_buf(&qiov, buf, len); 4610 4611 qemu_co_mutex_unlock(&s->lock); 4612 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0); 4613 qemu_co_mutex_lock(&s->lock); 4614 4615 qemu_vfree(buf); 4616 if (ret < 0) { 4617 error_setg_errno(errp, -ret, "Failed to zero out the new area"); 4618 goto fail; 4619 } 4620 } 4621 } 4622 4623 if (prealloc != PREALLOC_MODE_OFF) { 4624 /* Flush metadata before actually changing the image size */ 4625 ret = qcow2_write_caches(bs); 4626 if (ret < 0) { 4627 error_setg_errno(errp, -ret, 4628 "Failed to flush the preallocated area to disk"); 4629 goto fail; 4630 } 4631 } 4632 4633 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 4634 4635 /* write updated header.size */ 4636 offset = cpu_to_be64(offset); 4637 ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size), 4638 sizeof(offset), &offset, 0); 4639 if (ret < 0) { 4640 error_setg_errno(errp, -ret, "Failed to update the image size"); 4641 goto fail; 4642 } 4643 4644 s->l1_vm_state_index = new_l1_size; 4645 4646 /* Update cache sizes */ 4647 options = qdict_clone_shallow(bs->options); 4648 ret = qcow2_update_options(bs, options, s->flags, errp); 4649 qobject_unref(options); 4650 if (ret < 0) { 4651 goto fail; 4652 } 4653 ret = 0; 4654 fail: 4655 qemu_co_mutex_unlock(&s->lock); 4656 return ret; 4657 } 4658 4659 static int coroutine_fn GRAPH_RDLOCK 4660 qcow2_co_pwritev_compressed_task(BlockDriverState *bs, 4661 uint64_t offset, uint64_t bytes, 4662 QEMUIOVector *qiov, size_t qiov_offset) 4663 { 4664 BDRVQcow2State *s = bs->opaque; 4665 int ret; 4666 ssize_t out_len; 4667 uint8_t *buf, *out_buf; 4668 uint64_t cluster_offset; 4669 4670 assert(bytes == s->cluster_size || (bytes < s->cluster_size && 4671 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))); 4672 4673 buf = qemu_blockalign(bs, s->cluster_size); 4674 if (bytes < s->cluster_size) { 4675 /* Zero-pad last write if image size is not cluster aligned */ 4676 memset(buf + bytes, 0, s->cluster_size - bytes); 4677 } 4678 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); 4679 4680 out_buf = g_malloc(s->cluster_size); 4681 4682 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4683 buf, s->cluster_size); 4684 if (out_len == -ENOMEM) { 4685 /* could not compress: write normal cluster */ 4686 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); 4687 if (ret < 0) { 4688 goto fail; 4689 } 4690 goto success; 4691 } else if (out_len < 0) { 4692 ret = -EINVAL; 4693 goto fail; 4694 } 4695 4696 qemu_co_mutex_lock(&s->lock); 4697 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4698 &cluster_offset); 4699 if (ret < 0) { 4700 qemu_co_mutex_unlock(&s->lock); 4701 goto fail; 4702 } 4703 4704 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4705 qemu_co_mutex_unlock(&s->lock); 4706 if (ret < 0) { 4707 goto fail; 4708 } 4709 4710 BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4711 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); 4712 if (ret < 0) { 4713 goto fail; 4714 } 4715 success: 4716 ret = 0; 4717 fail: 4718 qemu_vfree(buf); 4719 g_free(out_buf); 4720 return ret; 4721 } 4722 4723 /* 4724 * This function can count as GRAPH_RDLOCK because 4725 * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until 4726 * this coroutine has terminated. 4727 */ 4728 static int coroutine_fn GRAPH_RDLOCK 4729 qcow2_co_pwritev_compressed_task_entry(AioTask *task) 4730 { 4731 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 4732 4733 assert(!t->subcluster_type && !t->l2meta); 4734 4735 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov, 4736 t->qiov_offset); 4737 } 4738 4739 /* 4740 * XXX: put compressed sectors first, then all the cluster aligned 4741 * tables to avoid losing bytes in alignment 4742 */ 4743 static int coroutine_fn GRAPH_RDLOCK 4744 qcow2_co_pwritev_compressed_part(BlockDriverState *bs, 4745 int64_t offset, int64_t bytes, 4746 QEMUIOVector *qiov, size_t qiov_offset) 4747 { 4748 BDRVQcow2State *s = bs->opaque; 4749 AioTaskPool *aio = NULL; 4750 int ret = 0; 4751 4752 if (has_data_file(bs)) { 4753 return -ENOTSUP; 4754 } 4755 4756 if (bytes == 0) { 4757 /* 4758 * align end of file to a sector boundary to ease reading with 4759 * sector based I/Os 4760 */ 4761 int64_t len = bdrv_co_getlength(bs->file->bs); 4762 if (len < 0) { 4763 return len; 4764 } 4765 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0, 4766 NULL); 4767 } 4768 4769 if (offset_into_cluster(s, offset)) { 4770 return -EINVAL; 4771 } 4772 4773 if (offset_into_cluster(s, bytes) && 4774 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) { 4775 return -EINVAL; 4776 } 4777 4778 while (bytes && aio_task_pool_status(aio) == 0) { 4779 uint64_t chunk_size = MIN(bytes, s->cluster_size); 4780 4781 if (!aio && chunk_size != bytes) { 4782 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 4783 } 4784 4785 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry, 4786 0, 0, offset, chunk_size, qiov, qiov_offset, NULL); 4787 if (ret < 0) { 4788 break; 4789 } 4790 qiov_offset += chunk_size; 4791 offset += chunk_size; 4792 bytes -= chunk_size; 4793 } 4794 4795 if (aio) { 4796 aio_task_pool_wait_all(aio); 4797 if (ret == 0) { 4798 ret = aio_task_pool_status(aio); 4799 } 4800 g_free(aio); 4801 } 4802 4803 return ret; 4804 } 4805 4806 static int coroutine_fn GRAPH_RDLOCK 4807 qcow2_co_preadv_compressed(BlockDriverState *bs, 4808 uint64_t l2_entry, 4809 uint64_t offset, 4810 uint64_t bytes, 4811 QEMUIOVector *qiov, 4812 size_t qiov_offset) 4813 { 4814 BDRVQcow2State *s = bs->opaque; 4815 int ret = 0, csize; 4816 uint64_t coffset; 4817 uint8_t *buf, *out_buf; 4818 int offset_in_cluster = offset_into_cluster(s, offset); 4819 4820 qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize); 4821 4822 buf = g_try_malloc(csize); 4823 if (!buf) { 4824 return -ENOMEM; 4825 } 4826 4827 out_buf = qemu_blockalign(bs, s->cluster_size); 4828 4829 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4830 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0); 4831 if (ret < 0) { 4832 goto fail; 4833 } 4834 4835 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4836 ret = -EIO; 4837 goto fail; 4838 } 4839 4840 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); 4841 4842 fail: 4843 qemu_vfree(out_buf); 4844 g_free(buf); 4845 4846 return ret; 4847 } 4848 4849 static int GRAPH_RDLOCK make_completely_empty(BlockDriverState *bs) 4850 { 4851 BDRVQcow2State *s = bs->opaque; 4852 Error *local_err = NULL; 4853 int ret, l1_clusters; 4854 int64_t offset; 4855 uint64_t *new_reftable = NULL; 4856 uint64_t rt_entry, l1_size2; 4857 struct { 4858 uint64_t l1_offset; 4859 uint64_t reftable_offset; 4860 uint32_t reftable_clusters; 4861 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4862 4863 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4864 if (ret < 0) { 4865 goto fail; 4866 } 4867 4868 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4869 if (ret < 0) { 4870 goto fail; 4871 } 4872 4873 /* Refcounts will be broken utterly */ 4874 ret = qcow2_mark_dirty(bs); 4875 if (ret < 0) { 4876 goto fail; 4877 } 4878 4879 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4880 4881 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 4882 l1_size2 = (uint64_t)s->l1_size * L1E_SIZE; 4883 4884 /* After this call, neither the in-memory nor the on-disk refcount 4885 * information accurately describe the actual references */ 4886 4887 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4888 l1_clusters * s->cluster_size, 0); 4889 if (ret < 0) { 4890 goto fail_broken_refcounts; 4891 } 4892 memset(s->l1_table, 0, l1_size2); 4893 4894 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4895 4896 /* Overwrite enough clusters at the beginning of the sectors to place 4897 * the refcount table, a refcount block and the L1 table in; this may 4898 * overwrite parts of the existing refcount and L1 table, which is not 4899 * an issue because the dirty flag is set, complete data loss is in fact 4900 * desired and partial data loss is consequently fine as well */ 4901 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4902 (2 + l1_clusters) * s->cluster_size, 0); 4903 /* This call (even if it failed overall) may have overwritten on-disk 4904 * refcount structures; in that case, the in-memory refcount information 4905 * will probably differ from the on-disk information which makes the BDS 4906 * unusable */ 4907 if (ret < 0) { 4908 goto fail_broken_refcounts; 4909 } 4910 4911 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4912 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4913 4914 /* "Create" an empty reftable (one cluster) directly after the image 4915 * header and an empty L1 table three clusters after the image header; 4916 * the cluster between those two will be used as the first refblock */ 4917 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4918 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4919 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4920 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4921 sizeof(l1_ofs_rt_ofs_cls), &l1_ofs_rt_ofs_cls, 0); 4922 if (ret < 0) { 4923 goto fail_broken_refcounts; 4924 } 4925 4926 s->l1_table_offset = 3 * s->cluster_size; 4927 4928 new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE); 4929 if (!new_reftable) { 4930 ret = -ENOMEM; 4931 goto fail_broken_refcounts; 4932 } 4933 4934 s->refcount_table_offset = s->cluster_size; 4935 s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE; 4936 s->max_refcount_table_index = 0; 4937 4938 g_free(s->refcount_table); 4939 s->refcount_table = new_reftable; 4940 new_reftable = NULL; 4941 4942 /* Now the in-memory refcount information again corresponds to the on-disk 4943 * information (reftable is empty and no refblocks (the refblock cache is 4944 * empty)); however, this means some clusters (e.g. the image header) are 4945 * referenced, but not refcounted, but the normal qcow2 code assumes that 4946 * the in-memory information is always correct */ 4947 4948 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4949 4950 /* Enter the first refblock into the reftable */ 4951 rt_entry = cpu_to_be64(2 * s->cluster_size); 4952 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, sizeof(rt_entry), 4953 &rt_entry, 0); 4954 if (ret < 0) { 4955 goto fail_broken_refcounts; 4956 } 4957 s->refcount_table[0] = 2 * s->cluster_size; 4958 4959 s->free_cluster_index = 0; 4960 assert(3 + l1_clusters <= s->refcount_block_size); 4961 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4962 if (offset < 0) { 4963 ret = offset; 4964 goto fail_broken_refcounts; 4965 } else if (offset > 0) { 4966 error_report("First cluster in emptied image is in use"); 4967 abort(); 4968 } 4969 4970 /* Now finally the in-memory information corresponds to the on-disk 4971 * structures and is correct */ 4972 ret = qcow2_mark_clean(bs); 4973 if (ret < 0) { 4974 goto fail; 4975 } 4976 4977 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false, 4978 PREALLOC_MODE_OFF, 0, &local_err); 4979 if (ret < 0) { 4980 error_report_err(local_err); 4981 goto fail; 4982 } 4983 4984 return 0; 4985 4986 fail_broken_refcounts: 4987 /* The BDS is unusable at this point. If we wanted to make it usable, we 4988 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 4989 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 4990 * again. However, because the functions which could have caused this error 4991 * path to be taken are used by those functions as well, it's very likely 4992 * that that sequence will fail as well. Therefore, just eject the BDS. */ 4993 bs->drv = NULL; 4994 4995 fail: 4996 g_free(new_reftable); 4997 return ret; 4998 } 4999 5000 static int GRAPH_RDLOCK qcow2_make_empty(BlockDriverState *bs) 5001 { 5002 BDRVQcow2State *s = bs->opaque; 5003 uint64_t offset, end_offset; 5004 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 5005 int l1_clusters, ret = 0; 5006 5007 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 5008 5009 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 5010 3 + l1_clusters <= s->refcount_block_size && 5011 s->crypt_method_header != QCOW_CRYPT_LUKS && 5012 !has_data_file(bs)) { 5013 /* The following function only works for qcow2 v3 images (it 5014 * requires the dirty flag) and only as long as there are no 5015 * features that reserve extra clusters (such as snapshots, 5016 * LUKS header, or persistent bitmaps), because it completely 5017 * empties the image. Furthermore, the L1 table and three 5018 * additional clusters (image header, refcount table, one 5019 * refcount block) have to fit inside one refcount block. It 5020 * only resets the image file, i.e. does not work with an 5021 * external data file. */ 5022 return make_completely_empty(bs); 5023 } 5024 5025 /* This fallback code simply discards every active cluster; this is slow, 5026 * but works in all cases */ 5027 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 5028 for (offset = 0; offset < end_offset; offset += step) { 5029 /* As this function is generally used after committing an external 5030 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 5031 * default action for this kind of discard is to pass the discard, 5032 * which will ideally result in an actually smaller image file, as 5033 * is probably desired. */ 5034 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 5035 QCOW2_DISCARD_SNAPSHOT, true); 5036 if (ret < 0) { 5037 break; 5038 } 5039 } 5040 5041 return ret; 5042 } 5043 5044 static coroutine_fn GRAPH_RDLOCK int qcow2_co_flush_to_os(BlockDriverState *bs) 5045 { 5046 BDRVQcow2State *s = bs->opaque; 5047 int ret; 5048 5049 qemu_co_mutex_lock(&s->lock); 5050 ret = qcow2_write_caches(bs); 5051 qemu_co_mutex_unlock(&s->lock); 5052 5053 return ret; 5054 } 5055 5056 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 5057 Error **errp) 5058 { 5059 Error *local_err = NULL; 5060 BlockMeasureInfo *info; 5061 uint64_t required = 0; /* bytes that contribute to required size */ 5062 uint64_t virtual_size; /* disk size as seen by guest */ 5063 uint64_t refcount_bits; 5064 uint64_t l2_tables; 5065 uint64_t luks_payload_size = 0; 5066 size_t cluster_size; 5067 int version; 5068 char *optstr; 5069 PreallocMode prealloc; 5070 bool has_backing_file; 5071 bool has_luks; 5072 bool extended_l2; 5073 size_t l2e_size; 5074 5075 /* Parse image creation options */ 5076 extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false); 5077 5078 cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2, 5079 &local_err); 5080 if (local_err) { 5081 goto err; 5082 } 5083 5084 version = qcow2_opt_get_version_del(opts, &local_err); 5085 if (local_err) { 5086 goto err; 5087 } 5088 5089 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 5090 if (local_err) { 5091 goto err; 5092 } 5093 5094 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 5095 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 5096 PREALLOC_MODE_OFF, &local_err); 5097 g_free(optstr); 5098 if (local_err) { 5099 goto err; 5100 } 5101 5102 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 5103 has_backing_file = !!optstr; 5104 g_free(optstr); 5105 5106 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 5107 has_luks = optstr && strcmp(optstr, "luks") == 0; 5108 g_free(optstr); 5109 5110 if (has_luks) { 5111 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL; 5112 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp); 5113 size_t headerlen; 5114 5115 create_opts = block_crypto_create_opts_init(cryptoopts, errp); 5116 qobject_unref(cryptoopts); 5117 if (!create_opts) { 5118 goto err; 5119 } 5120 5121 if (!qcrypto_block_calculate_payload_offset(create_opts, 5122 "encrypt.", 5123 &headerlen, 5124 &local_err)) { 5125 goto err; 5126 } 5127 5128 luks_payload_size = ROUND_UP(headerlen, cluster_size); 5129 } 5130 5131 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 5132 virtual_size = ROUND_UP(virtual_size, cluster_size); 5133 5134 /* Check that virtual disk size is valid */ 5135 l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 5136 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 5137 cluster_size / l2e_size); 5138 if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) { 5139 error_setg(&local_err, "The image size is too large " 5140 "(try using a larger cluster size)"); 5141 goto err; 5142 } 5143 5144 /* Account for input image */ 5145 if (in_bs) { 5146 int64_t ssize = bdrv_getlength(in_bs); 5147 if (ssize < 0) { 5148 error_setg_errno(&local_err, -ssize, 5149 "Unable to get image virtual_size"); 5150 goto err; 5151 } 5152 5153 virtual_size = ROUND_UP(ssize, cluster_size); 5154 5155 if (has_backing_file) { 5156 /* We don't how much of the backing chain is shared by the input 5157 * image and the new image file. In the worst case the new image's 5158 * backing file has nothing in common with the input image. Be 5159 * conservative and assume all clusters need to be written. 5160 */ 5161 required = virtual_size; 5162 } else { 5163 int64_t offset; 5164 int64_t pnum = 0; 5165 5166 for (offset = 0; offset < ssize; offset += pnum) { 5167 int ret; 5168 5169 ret = bdrv_block_status_above(in_bs, NULL, offset, 5170 ssize - offset, &pnum, NULL, 5171 NULL); 5172 if (ret < 0) { 5173 error_setg_errno(&local_err, -ret, 5174 "Unable to get block status"); 5175 goto err; 5176 } 5177 5178 if (ret & BDRV_BLOCK_ZERO) { 5179 /* Skip zero regions (safe with no backing file) */ 5180 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 5181 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 5182 /* Extend pnum to end of cluster for next iteration */ 5183 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 5184 5185 /* Count clusters we've seen */ 5186 required += offset % cluster_size + pnum; 5187 } 5188 } 5189 } 5190 } 5191 5192 /* Take into account preallocation. Nothing special is needed for 5193 * PREALLOC_MODE_METADATA since metadata is always counted. 5194 */ 5195 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 5196 required = virtual_size; 5197 } 5198 5199 info = g_new0(BlockMeasureInfo, 1); 5200 info->fully_allocated = luks_payload_size + 5201 qcow2_calc_prealloc_size(virtual_size, cluster_size, 5202 ctz32(refcount_bits), extended_l2); 5203 5204 /* 5205 * Remove data clusters that are not required. This overestimates the 5206 * required size because metadata needed for the fully allocated file is 5207 * still counted. Show bitmaps only if both source and destination 5208 * would support them. 5209 */ 5210 info->required = info->fully_allocated - virtual_size + required; 5211 info->has_bitmaps = version >= 3 && in_bs && 5212 bdrv_supports_persistent_dirty_bitmap(in_bs); 5213 if (info->has_bitmaps) { 5214 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs, 5215 cluster_size); 5216 } 5217 return info; 5218 5219 err: 5220 error_propagate(errp, local_err); 5221 return NULL; 5222 } 5223 5224 static int coroutine_fn 5225 qcow2_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 5226 { 5227 BDRVQcow2State *s = bs->opaque; 5228 bdi->cluster_size = s->cluster_size; 5229 bdi->subcluster_size = s->subcluster_size; 5230 bdi->vm_state_offset = qcow2_vm_state_offset(s); 5231 bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY; 5232 return 0; 5233 } 5234 5235 static ImageInfoSpecific * GRAPH_RDLOCK 5236 qcow2_get_specific_info(BlockDriverState *bs, Error **errp) 5237 { 5238 BDRVQcow2State *s = bs->opaque; 5239 ImageInfoSpecific *spec_info; 5240 QCryptoBlockInfo *encrypt_info = NULL; 5241 5242 if (s->crypto != NULL) { 5243 encrypt_info = qcrypto_block_get_info(s->crypto, errp); 5244 if (!encrypt_info) { 5245 return NULL; 5246 } 5247 } 5248 5249 spec_info = g_new(ImageInfoSpecific, 1); 5250 *spec_info = (ImageInfoSpecific){ 5251 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 5252 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 5253 }; 5254 if (s->qcow_version == 2) { 5255 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5256 .compat = g_strdup("0.10"), 5257 .refcount_bits = s->refcount_bits, 5258 }; 5259 } else if (s->qcow_version == 3) { 5260 Qcow2BitmapInfoList *bitmaps; 5261 if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) { 5262 qapi_free_ImageInfoSpecific(spec_info); 5263 qapi_free_QCryptoBlockInfo(encrypt_info); 5264 return NULL; 5265 } 5266 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5267 .compat = g_strdup("1.1"), 5268 .lazy_refcounts = s->compatible_features & 5269 QCOW2_COMPAT_LAZY_REFCOUNTS, 5270 .has_lazy_refcounts = true, 5271 .corrupt = s->incompatible_features & 5272 QCOW2_INCOMPAT_CORRUPT, 5273 .has_corrupt = true, 5274 .has_extended_l2 = true, 5275 .extended_l2 = has_subclusters(s), 5276 .refcount_bits = s->refcount_bits, 5277 .has_bitmaps = !!bitmaps, 5278 .bitmaps = bitmaps, 5279 .data_file = g_strdup(s->image_data_file), 5280 .has_data_file_raw = has_data_file(bs), 5281 .data_file_raw = data_file_is_raw(bs), 5282 .compression_type = s->compression_type, 5283 }; 5284 } else { 5285 /* if this assertion fails, this probably means a new version was 5286 * added without having it covered here */ 5287 assert(false); 5288 } 5289 5290 if (encrypt_info) { 5291 ImageInfoSpecificQCow2Encryption *qencrypt = 5292 g_new(ImageInfoSpecificQCow2Encryption, 1); 5293 switch (encrypt_info->format) { 5294 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 5295 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 5296 break; 5297 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 5298 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 5299 qencrypt->u.luks = encrypt_info->u.luks; 5300 break; 5301 default: 5302 abort(); 5303 } 5304 /* Since we did shallow copy above, erase any pointers 5305 * in the original info */ 5306 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 5307 qapi_free_QCryptoBlockInfo(encrypt_info); 5308 5309 spec_info->u.qcow2.data->encrypt = qencrypt; 5310 } 5311 5312 return spec_info; 5313 } 5314 5315 static int coroutine_mixed_fn GRAPH_RDLOCK 5316 qcow2_has_zero_init(BlockDriverState *bs) 5317 { 5318 BDRVQcow2State *s = bs->opaque; 5319 bool preallocated; 5320 5321 if (qemu_in_coroutine()) { 5322 qemu_co_mutex_lock(&s->lock); 5323 } 5324 /* 5325 * Check preallocation status: Preallocated images have all L2 5326 * tables allocated, nonpreallocated images have none. It is 5327 * therefore enough to check the first one. 5328 */ 5329 preallocated = s->l1_size > 0 && s->l1_table[0] != 0; 5330 if (qemu_in_coroutine()) { 5331 qemu_co_mutex_unlock(&s->lock); 5332 } 5333 5334 if (!preallocated) { 5335 return 1; 5336 } else if (bs->encrypted) { 5337 return 0; 5338 } else { 5339 return bdrv_has_zero_init(s->data_file->bs); 5340 } 5341 } 5342 5343 /* 5344 * Check the request to vmstate. On success return 5345 * qcow2_vm_state_offset(bs) + @pos 5346 */ 5347 static int64_t qcow2_check_vmstate_request(BlockDriverState *bs, 5348 QEMUIOVector *qiov, int64_t pos) 5349 { 5350 BDRVQcow2State *s = bs->opaque; 5351 int64_t vmstate_offset = qcow2_vm_state_offset(s); 5352 int ret; 5353 5354 /* Incoming requests must be OK */ 5355 bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort); 5356 5357 if (INT64_MAX - pos < vmstate_offset) { 5358 return -EIO; 5359 } 5360 5361 pos += vmstate_offset; 5362 ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL); 5363 if (ret < 0) { 5364 return ret; 5365 } 5366 5367 return pos; 5368 } 5369 5370 static int coroutine_fn GRAPH_RDLOCK 5371 qcow2_co_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5372 { 5373 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5374 if (offset < 0) { 5375 return offset; 5376 } 5377 5378 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 5379 return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0); 5380 } 5381 5382 static int coroutine_fn GRAPH_RDLOCK 5383 qcow2_co_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5384 { 5385 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5386 if (offset < 0) { 5387 return offset; 5388 } 5389 5390 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 5391 return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0); 5392 } 5393 5394 static int GRAPH_RDLOCK qcow2_has_compressed_clusters(BlockDriverState *bs) 5395 { 5396 int64_t offset = 0; 5397 int64_t bytes = bdrv_getlength(bs); 5398 5399 if (bytes < 0) { 5400 return bytes; 5401 } 5402 5403 while (bytes != 0) { 5404 int ret; 5405 QCow2SubclusterType type; 5406 unsigned int cur_bytes = MIN(INT_MAX, bytes); 5407 uint64_t host_offset; 5408 5409 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset, 5410 &type); 5411 if (ret < 0) { 5412 return ret; 5413 } 5414 5415 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 5416 return 1; 5417 } 5418 5419 offset += cur_bytes; 5420 bytes -= cur_bytes; 5421 } 5422 5423 return 0; 5424 } 5425 5426 /* 5427 * Downgrades an image's version. To achieve this, any incompatible features 5428 * have to be removed. 5429 */ 5430 static int GRAPH_RDLOCK 5431 qcow2_downgrade(BlockDriverState *bs, int target_version, 5432 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5433 Error **errp) 5434 { 5435 BDRVQcow2State *s = bs->opaque; 5436 int current_version = s->qcow_version; 5437 int ret; 5438 int i; 5439 5440 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 5441 assert(target_version < current_version); 5442 5443 /* There are no other versions (now) that you can downgrade to */ 5444 assert(target_version == 2); 5445 5446 if (s->refcount_order != 4) { 5447 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 5448 return -ENOTSUP; 5449 } 5450 5451 if (has_data_file(bs)) { 5452 error_setg(errp, "Cannot downgrade an image with a data file"); 5453 return -ENOTSUP; 5454 } 5455 5456 /* 5457 * If any internal snapshot has a different size than the current 5458 * image size, or VM state size that exceeds 32 bits, downgrading 5459 * is unsafe. Even though we would still use v3-compliant output 5460 * to preserve that data, other v2 programs might not realize 5461 * those optional fields are important. 5462 */ 5463 for (i = 0; i < s->nb_snapshots; i++) { 5464 if (s->snapshots[i].vm_state_size > UINT32_MAX || 5465 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { 5466 error_setg(errp, "Internal snapshots prevent downgrade of image"); 5467 return -ENOTSUP; 5468 } 5469 } 5470 5471 /* clear incompatible features */ 5472 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 5473 ret = qcow2_mark_clean(bs); 5474 if (ret < 0) { 5475 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5476 return ret; 5477 } 5478 } 5479 5480 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 5481 * the first place; if that happens nonetheless, returning -ENOTSUP is the 5482 * best thing to do anyway */ 5483 5484 if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) { 5485 error_setg(errp, "Cannot downgrade an image with incompatible features " 5486 "0x%" PRIx64 " set", 5487 s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION); 5488 return -ENOTSUP; 5489 } 5490 5491 /* since we can ignore compatible features, we can set them to 0 as well */ 5492 s->compatible_features = 0; 5493 /* if lazy refcounts have been used, they have already been fixed through 5494 * clearing the dirty flag */ 5495 5496 /* clearing autoclear features is trivial */ 5497 s->autoclear_features = 0; 5498 5499 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 5500 if (ret < 0) { 5501 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 5502 return ret; 5503 } 5504 5505 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 5506 ret = qcow2_has_compressed_clusters(bs); 5507 if (ret < 0) { 5508 error_setg(errp, "Failed to check block status"); 5509 return -EINVAL; 5510 } 5511 if (ret) { 5512 error_setg(errp, "Cannot downgrade an image with zstd compression " 5513 "type and existing compressed clusters"); 5514 return -ENOTSUP; 5515 } 5516 /* 5517 * No compressed clusters for now, so just chose default zlib 5518 * compression. 5519 */ 5520 s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION; 5521 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 5522 } 5523 5524 assert(s->incompatible_features == 0); 5525 5526 s->qcow_version = target_version; 5527 ret = qcow2_update_header(bs); 5528 if (ret < 0) { 5529 s->qcow_version = current_version; 5530 error_setg_errno(errp, -ret, "Failed to update the image header"); 5531 return ret; 5532 } 5533 return 0; 5534 } 5535 5536 /* 5537 * Upgrades an image's version. While newer versions encompass all 5538 * features of older versions, some things may have to be presented 5539 * differently. 5540 */ 5541 static int GRAPH_RDLOCK 5542 qcow2_upgrade(BlockDriverState *bs, int target_version, 5543 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5544 Error **errp) 5545 { 5546 BDRVQcow2State *s = bs->opaque; 5547 bool need_snapshot_update; 5548 int current_version = s->qcow_version; 5549 int i; 5550 int ret; 5551 5552 /* This is qcow2_upgrade(), not qcow2_downgrade() */ 5553 assert(target_version > current_version); 5554 5555 /* There are no other versions (yet) that you can upgrade to */ 5556 assert(target_version == 3); 5557 5558 status_cb(bs, 0, 2, cb_opaque); 5559 5560 /* 5561 * In v2, snapshots do not need to have extra data. v3 requires 5562 * the 64-bit VM state size and the virtual disk size to be 5563 * present. 5564 * qcow2_write_snapshots() will always write the list in the 5565 * v3-compliant format. 5566 */ 5567 need_snapshot_update = false; 5568 for (i = 0; i < s->nb_snapshots; i++) { 5569 if (s->snapshots[i].extra_data_size < 5570 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) + 5571 sizeof_field(QCowSnapshotExtraData, disk_size)) 5572 { 5573 need_snapshot_update = true; 5574 break; 5575 } 5576 } 5577 if (need_snapshot_update) { 5578 ret = qcow2_write_snapshots(bs); 5579 if (ret < 0) { 5580 error_setg_errno(errp, -ret, "Failed to update the snapshot table"); 5581 return ret; 5582 } 5583 } 5584 status_cb(bs, 1, 2, cb_opaque); 5585 5586 s->qcow_version = target_version; 5587 ret = qcow2_update_header(bs); 5588 if (ret < 0) { 5589 s->qcow_version = current_version; 5590 error_setg_errno(errp, -ret, "Failed to update the image header"); 5591 return ret; 5592 } 5593 status_cb(bs, 2, 2, cb_opaque); 5594 5595 return 0; 5596 } 5597 5598 typedef enum Qcow2AmendOperation { 5599 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 5600 * statically initialized to so that the helper CB can discern the first 5601 * invocation from an operation change */ 5602 QCOW2_NO_OPERATION = 0, 5603 5604 QCOW2_UPGRADING, 5605 QCOW2_UPDATING_ENCRYPTION, 5606 QCOW2_CHANGING_REFCOUNT_ORDER, 5607 QCOW2_DOWNGRADING, 5608 } Qcow2AmendOperation; 5609 5610 typedef struct Qcow2AmendHelperCBInfo { 5611 /* The code coordinating the amend operations should only modify 5612 * these four fields; the rest will be managed by the CB */ 5613 BlockDriverAmendStatusCB *original_status_cb; 5614 void *original_cb_opaque; 5615 5616 Qcow2AmendOperation current_operation; 5617 5618 /* Total number of operations to perform (only set once) */ 5619 int total_operations; 5620 5621 /* The following fields are managed by the CB */ 5622 5623 /* Number of operations completed */ 5624 int operations_completed; 5625 5626 /* Cumulative offset of all completed operations */ 5627 int64_t offset_completed; 5628 5629 Qcow2AmendOperation last_operation; 5630 int64_t last_work_size; 5631 } Qcow2AmendHelperCBInfo; 5632 5633 static void qcow2_amend_helper_cb(BlockDriverState *bs, 5634 int64_t operation_offset, 5635 int64_t operation_work_size, void *opaque) 5636 { 5637 Qcow2AmendHelperCBInfo *info = opaque; 5638 int64_t current_work_size; 5639 int64_t projected_work_size; 5640 5641 if (info->current_operation != info->last_operation) { 5642 if (info->last_operation != QCOW2_NO_OPERATION) { 5643 info->offset_completed += info->last_work_size; 5644 info->operations_completed++; 5645 } 5646 5647 info->last_operation = info->current_operation; 5648 } 5649 5650 assert(info->total_operations > 0); 5651 assert(info->operations_completed < info->total_operations); 5652 5653 info->last_work_size = operation_work_size; 5654 5655 current_work_size = info->offset_completed + operation_work_size; 5656 5657 /* current_work_size is the total work size for (operations_completed + 1) 5658 * operations (which includes this one), so multiply it by the number of 5659 * operations not covered and divide it by the number of operations 5660 * covered to get a projection for the operations not covered */ 5661 projected_work_size = current_work_size * (info->total_operations - 5662 info->operations_completed - 1) 5663 / (info->operations_completed + 1); 5664 5665 info->original_status_cb(bs, info->offset_completed + operation_offset, 5666 current_work_size + projected_work_size, 5667 info->original_cb_opaque); 5668 } 5669 5670 static int GRAPH_RDLOCK 5671 qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 5672 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5673 bool force, Error **errp) 5674 { 5675 BDRVQcow2State *s = bs->opaque; 5676 int old_version = s->qcow_version, new_version = old_version; 5677 uint64_t new_size = 0; 5678 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 5679 bool lazy_refcounts = s->use_lazy_refcounts; 5680 bool data_file_raw = data_file_is_raw(bs); 5681 const char *compat = NULL; 5682 int refcount_bits = s->refcount_bits; 5683 int ret; 5684 QemuOptDesc *desc = opts->list->desc; 5685 Qcow2AmendHelperCBInfo helper_cb_info; 5686 bool encryption_update = false; 5687 5688 while (desc && desc->name) { 5689 if (!qemu_opt_find(opts, desc->name)) { 5690 /* only change explicitly defined options */ 5691 desc++; 5692 continue; 5693 } 5694 5695 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 5696 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 5697 if (!compat) { 5698 /* preserve default */ 5699 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) { 5700 new_version = 2; 5701 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) { 5702 new_version = 3; 5703 } else { 5704 error_setg(errp, "Unknown compatibility level %s", compat); 5705 return -EINVAL; 5706 } 5707 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 5708 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 5709 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 5710 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 5711 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 5712 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 5713 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 5714 if (!s->crypto) { 5715 error_setg(errp, 5716 "Can't amend encryption options - encryption not present"); 5717 return -EINVAL; 5718 } 5719 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5720 error_setg(errp, 5721 "Only LUKS encryption options can be amended"); 5722 return -ENOTSUP; 5723 } 5724 encryption_update = true; 5725 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 5726 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 5727 lazy_refcounts); 5728 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 5729 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 5730 refcount_bits); 5731 5732 if (refcount_bits <= 0 || refcount_bits > 64 || 5733 !is_power_of_2(refcount_bits)) 5734 { 5735 error_setg(errp, "Refcount width must be a power of two and " 5736 "may not exceed 64 bits"); 5737 return -EINVAL; 5738 } 5739 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 5740 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 5741 if (data_file && !has_data_file(bs)) { 5742 error_setg(errp, "data-file can only be set for images that " 5743 "use an external data file"); 5744 return -EINVAL; 5745 } 5746 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 5747 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 5748 data_file_raw); 5749 if (data_file_raw && !data_file_is_raw(bs)) { 5750 error_setg(errp, "data-file-raw cannot be set on existing " 5751 "images"); 5752 return -EINVAL; 5753 } 5754 } else { 5755 /* if this point is reached, this probably means a new option was 5756 * added without having it covered here */ 5757 abort(); 5758 } 5759 5760 desc++; 5761 } 5762 5763 helper_cb_info = (Qcow2AmendHelperCBInfo){ 5764 .original_status_cb = status_cb, 5765 .original_cb_opaque = cb_opaque, 5766 .total_operations = (new_version != old_version) 5767 + (s->refcount_bits != refcount_bits) + 5768 (encryption_update == true) 5769 }; 5770 5771 /* Upgrade first (some features may require compat=1.1) */ 5772 if (new_version > old_version) { 5773 helper_cb_info.current_operation = QCOW2_UPGRADING; 5774 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb, 5775 &helper_cb_info, errp); 5776 if (ret < 0) { 5777 return ret; 5778 } 5779 } 5780 5781 if (encryption_update) { 5782 QDict *amend_opts_dict; 5783 QCryptoBlockAmendOptions *amend_opts; 5784 5785 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION; 5786 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp); 5787 if (!amend_opts_dict) { 5788 return -EINVAL; 5789 } 5790 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp); 5791 qobject_unref(amend_opts_dict); 5792 if (!amend_opts) { 5793 return -EINVAL; 5794 } 5795 ret = qcrypto_block_amend_options(s->crypto, 5796 qcow2_crypto_hdr_read_func, 5797 qcow2_crypto_hdr_write_func, 5798 bs, 5799 amend_opts, 5800 force, 5801 errp); 5802 qapi_free_QCryptoBlockAmendOptions(amend_opts); 5803 if (ret < 0) { 5804 return ret; 5805 } 5806 } 5807 5808 if (s->refcount_bits != refcount_bits) { 5809 int refcount_order = ctz32(refcount_bits); 5810 5811 if (new_version < 3 && refcount_bits != 16) { 5812 error_setg(errp, "Refcount widths other than 16 bits require " 5813 "compatibility level 1.1 or above (use compat=1.1 or " 5814 "greater)"); 5815 return -EINVAL; 5816 } 5817 5818 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 5819 ret = qcow2_change_refcount_order(bs, refcount_order, 5820 &qcow2_amend_helper_cb, 5821 &helper_cb_info, errp); 5822 if (ret < 0) { 5823 return ret; 5824 } 5825 } 5826 5827 /* data-file-raw blocks backing files, so clear it first if requested */ 5828 if (data_file_raw) { 5829 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5830 } else { 5831 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5832 } 5833 5834 if (data_file) { 5835 g_free(s->image_data_file); 5836 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 5837 } 5838 5839 ret = qcow2_update_header(bs); 5840 if (ret < 0) { 5841 error_setg_errno(errp, -ret, "Failed to update the image header"); 5842 return ret; 5843 } 5844 5845 if (backing_file || backing_format) { 5846 if (g_strcmp0(backing_file, s->image_backing_file) || 5847 g_strcmp0(backing_format, s->image_backing_format)) { 5848 error_setg(errp, "Cannot amend the backing file"); 5849 error_append_hint(errp, 5850 "You can use 'qemu-img rebase' instead.\n"); 5851 return -EINVAL; 5852 } 5853 } 5854 5855 if (s->use_lazy_refcounts != lazy_refcounts) { 5856 if (lazy_refcounts) { 5857 if (new_version < 3) { 5858 error_setg(errp, "Lazy refcounts only supported with " 5859 "compatibility level 1.1 and above (use compat=1.1 " 5860 "or greater)"); 5861 return -EINVAL; 5862 } 5863 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5864 ret = qcow2_update_header(bs); 5865 if (ret < 0) { 5866 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5867 error_setg_errno(errp, -ret, "Failed to update the image header"); 5868 return ret; 5869 } 5870 s->use_lazy_refcounts = true; 5871 } else { 5872 /* make image clean first */ 5873 ret = qcow2_mark_clean(bs); 5874 if (ret < 0) { 5875 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5876 return ret; 5877 } 5878 /* now disallow lazy refcounts */ 5879 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5880 ret = qcow2_update_header(bs); 5881 if (ret < 0) { 5882 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5883 error_setg_errno(errp, -ret, "Failed to update the image header"); 5884 return ret; 5885 } 5886 s->use_lazy_refcounts = false; 5887 } 5888 } 5889 5890 if (new_size) { 5891 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, 5892 errp); 5893 if (!blk) { 5894 return -EPERM; 5895 } 5896 5897 /* 5898 * Amending image options should ensure that the image has 5899 * exactly the given new values, so pass exact=true here. 5900 */ 5901 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp); 5902 blk_unref(blk); 5903 if (ret < 0) { 5904 return ret; 5905 } 5906 } 5907 5908 /* Downgrade last (so unsupported features can be removed before) */ 5909 if (new_version < old_version) { 5910 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5911 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5912 &helper_cb_info, errp); 5913 if (ret < 0) { 5914 return ret; 5915 } 5916 } 5917 5918 return 0; 5919 } 5920 5921 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs, 5922 BlockdevAmendOptions *opts, 5923 bool force, 5924 Error **errp) 5925 { 5926 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2; 5927 BDRVQcow2State *s = bs->opaque; 5928 int ret = 0; 5929 5930 if (qopts->encrypt) { 5931 if (!s->crypto) { 5932 error_setg(errp, "image is not encrypted, can't amend"); 5933 return -EOPNOTSUPP; 5934 } 5935 5936 if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) { 5937 error_setg(errp, 5938 "Amend can't be used to change the qcow2 encryption format"); 5939 return -EOPNOTSUPP; 5940 } 5941 5942 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5943 error_setg(errp, 5944 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend"); 5945 return -EOPNOTSUPP; 5946 } 5947 5948 ret = qcrypto_block_amend_options(s->crypto, 5949 qcow2_crypto_hdr_read_func, 5950 qcow2_crypto_hdr_write_func, 5951 bs, 5952 qopts->encrypt, 5953 force, 5954 errp); 5955 } 5956 return ret; 5957 } 5958 5959 /* 5960 * If offset or size are negative, respectively, they will not be included in 5961 * the BLOCK_IMAGE_CORRUPTED event emitted. 5962 * fatal will be ignored for read-only BDS; corruptions found there will always 5963 * be considered non-fatal. 5964 */ 5965 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5966 int64_t size, const char *message_format, ...) 5967 { 5968 BDRVQcow2State *s = bs->opaque; 5969 const char *node_name; 5970 char *message; 5971 va_list ap; 5972 5973 fatal = fatal && bdrv_is_writable(bs); 5974 5975 if (s->signaled_corruption && 5976 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5977 { 5978 return; 5979 } 5980 5981 va_start(ap, message_format); 5982 message = g_strdup_vprintf(message_format, ap); 5983 va_end(ap); 5984 5985 if (fatal) { 5986 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 5987 "corruption events will be suppressed\n", message); 5988 } else { 5989 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 5990 "corruption events will be suppressed\n", message); 5991 } 5992 5993 node_name = bdrv_get_node_name(bs); 5994 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 5995 *node_name ? node_name : NULL, 5996 message, offset >= 0, offset, 5997 size >= 0, size, 5998 fatal); 5999 g_free(message); 6000 6001 if (fatal) { 6002 qcow2_mark_corrupt(bs); 6003 bs->drv = NULL; /* make BDS unusable */ 6004 } 6005 6006 s->signaled_corruption = true; 6007 } 6008 6009 #define QCOW_COMMON_OPTIONS \ 6010 { \ 6011 .name = BLOCK_OPT_SIZE, \ 6012 .type = QEMU_OPT_SIZE, \ 6013 .help = "Virtual disk size" \ 6014 }, \ 6015 { \ 6016 .name = BLOCK_OPT_COMPAT_LEVEL, \ 6017 .type = QEMU_OPT_STRING, \ 6018 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \ 6019 }, \ 6020 { \ 6021 .name = BLOCK_OPT_BACKING_FILE, \ 6022 .type = QEMU_OPT_STRING, \ 6023 .help = "File name of a base image" \ 6024 }, \ 6025 { \ 6026 .name = BLOCK_OPT_BACKING_FMT, \ 6027 .type = QEMU_OPT_STRING, \ 6028 .help = "Image format of the base image" \ 6029 }, \ 6030 { \ 6031 .name = BLOCK_OPT_DATA_FILE, \ 6032 .type = QEMU_OPT_STRING, \ 6033 .help = "File name of an external data file" \ 6034 }, \ 6035 { \ 6036 .name = BLOCK_OPT_DATA_FILE_RAW, \ 6037 .type = QEMU_OPT_BOOL, \ 6038 .help = "The external data file must stay valid " \ 6039 "as a raw image" \ 6040 }, \ 6041 { \ 6042 .name = BLOCK_OPT_LAZY_REFCOUNTS, \ 6043 .type = QEMU_OPT_BOOL, \ 6044 .help = "Postpone refcount updates", \ 6045 .def_value_str = "off" \ 6046 }, \ 6047 { \ 6048 .name = BLOCK_OPT_REFCOUNT_BITS, \ 6049 .type = QEMU_OPT_NUMBER, \ 6050 .help = "Width of a reference count entry in bits", \ 6051 .def_value_str = "16" \ 6052 } 6053 6054 static QemuOptsList qcow2_create_opts = { 6055 .name = "qcow2-create-opts", 6056 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 6057 .desc = { 6058 { \ 6059 .name = BLOCK_OPT_ENCRYPT, \ 6060 .type = QEMU_OPT_BOOL, \ 6061 .help = "Encrypt the image with format 'aes'. (Deprecated " \ 6062 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \ 6063 }, \ 6064 { \ 6065 .name = BLOCK_OPT_ENCRYPT_FORMAT, \ 6066 .type = QEMU_OPT_STRING, \ 6067 .help = "Encrypt the image, format choices: 'aes', 'luks'", \ 6068 }, \ 6069 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \ 6070 "ID of secret providing qcow AES key or LUKS passphrase"), \ 6071 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \ 6072 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \ 6073 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \ 6074 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \ 6075 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \ 6076 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \ 6077 { \ 6078 .name = BLOCK_OPT_CLUSTER_SIZE, \ 6079 .type = QEMU_OPT_SIZE, \ 6080 .help = "qcow2 cluster size", \ 6081 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \ 6082 }, \ 6083 { \ 6084 .name = BLOCK_OPT_EXTL2, \ 6085 .type = QEMU_OPT_BOOL, \ 6086 .help = "Extended L2 tables", \ 6087 .def_value_str = "off" \ 6088 }, \ 6089 { \ 6090 .name = BLOCK_OPT_PREALLOC, \ 6091 .type = QEMU_OPT_STRING, \ 6092 .help = "Preallocation mode (allowed values: off, " \ 6093 "metadata, falloc, full)" \ 6094 }, \ 6095 { \ 6096 .name = BLOCK_OPT_COMPRESSION_TYPE, \ 6097 .type = QEMU_OPT_STRING, \ 6098 .help = "Compression method used for image cluster " \ 6099 "compression", \ 6100 .def_value_str = "zlib" \ 6101 }, 6102 QCOW_COMMON_OPTIONS, 6103 { /* end of list */ } 6104 } 6105 }; 6106 6107 static QemuOptsList qcow2_amend_opts = { 6108 .name = "qcow2-amend-opts", 6109 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head), 6110 .desc = { 6111 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."), 6112 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."), 6113 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."), 6114 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."), 6115 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 6116 QCOW_COMMON_OPTIONS, 6117 { /* end of list */ } 6118 } 6119 }; 6120 6121 static const char *const qcow2_strong_runtime_opts[] = { 6122 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 6123 6124 NULL 6125 }; 6126 6127 BlockDriver bdrv_qcow2 = { 6128 .format_name = "qcow2", 6129 .instance_size = sizeof(BDRVQcow2State), 6130 .bdrv_probe = qcow2_probe, 6131 .bdrv_open = qcow2_open, 6132 .bdrv_close = qcow2_close, 6133 .bdrv_reopen_prepare = qcow2_reopen_prepare, 6134 .bdrv_reopen_commit = qcow2_reopen_commit, 6135 .bdrv_reopen_commit_post = qcow2_reopen_commit_post, 6136 .bdrv_reopen_abort = qcow2_reopen_abort, 6137 .bdrv_join_options = qcow2_join_options, 6138 .bdrv_child_perm = bdrv_default_perms, 6139 .bdrv_co_create_opts = qcow2_co_create_opts, 6140 .bdrv_co_create = qcow2_co_create, 6141 .bdrv_has_zero_init = qcow2_has_zero_init, 6142 .bdrv_co_block_status = qcow2_co_block_status, 6143 6144 .bdrv_co_preadv_part = qcow2_co_preadv_part, 6145 .bdrv_co_pwritev_part = qcow2_co_pwritev_part, 6146 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 6147 6148 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 6149 .bdrv_co_pdiscard = qcow2_co_pdiscard, 6150 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 6151 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 6152 .bdrv_co_truncate = qcow2_co_truncate, 6153 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part, 6154 .bdrv_make_empty = qcow2_make_empty, 6155 6156 .bdrv_snapshot_create = qcow2_snapshot_create, 6157 .bdrv_snapshot_goto = qcow2_snapshot_goto, 6158 .bdrv_snapshot_delete = qcow2_snapshot_delete, 6159 .bdrv_snapshot_list = qcow2_snapshot_list, 6160 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 6161 .bdrv_measure = qcow2_measure, 6162 .bdrv_co_get_info = qcow2_co_get_info, 6163 .bdrv_get_specific_info = qcow2_get_specific_info, 6164 6165 .bdrv_co_save_vmstate = qcow2_co_save_vmstate, 6166 .bdrv_co_load_vmstate = qcow2_co_load_vmstate, 6167 6168 .is_format = true, 6169 .supports_backing = true, 6170 .bdrv_co_change_backing_file = qcow2_co_change_backing_file, 6171 6172 .bdrv_refresh_limits = qcow2_refresh_limits, 6173 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 6174 .bdrv_inactivate = qcow2_inactivate, 6175 6176 .create_opts = &qcow2_create_opts, 6177 .amend_opts = &qcow2_amend_opts, 6178 .strong_runtime_opts = qcow2_strong_runtime_opts, 6179 .mutable_opts = mutable_opts, 6180 .bdrv_co_check = qcow2_co_check, 6181 .bdrv_amend_options = qcow2_amend_options, 6182 .bdrv_co_amend = qcow2_co_amend, 6183 6184 .bdrv_detach_aio_context = qcow2_detach_aio_context, 6185 .bdrv_attach_aio_context = qcow2_attach_aio_context, 6186 6187 .bdrv_supports_persistent_dirty_bitmap = 6188 qcow2_supports_persistent_dirty_bitmap, 6189 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap, 6190 .bdrv_co_remove_persistent_dirty_bitmap = 6191 qcow2_co_remove_persistent_dirty_bitmap, 6192 }; 6193 6194 static void bdrv_qcow2_init(void) 6195 { 6196 bdrv_register(&bdrv_qcow2); 6197 } 6198 6199 block_init(bdrv_qcow2_init); 6200