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, QCOW2_MAX_THREADS, 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, 1705 QCOW2_MAX_THREADS, errp); 1706 if (!s->crypto) { 1707 ret = -EINVAL; 1708 goto fail; 1709 } 1710 } else if (!(flags & BDRV_O_NO_IO)) { 1711 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1712 s->crypt_method_header); 1713 ret = -EINVAL; 1714 goto fail; 1715 } 1716 } 1717 1718 /* read the backing file name */ 1719 if (header.backing_file_offset != 0) { 1720 len = header.backing_file_size; 1721 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1722 len >= sizeof(bs->backing_file)) { 1723 error_setg(errp, "Backing file name too long"); 1724 ret = -EINVAL; 1725 goto fail; 1726 } 1727 1728 s->image_backing_file = g_malloc(len + 1); 1729 ret = bdrv_co_pread(bs->file, header.backing_file_offset, len, 1730 s->image_backing_file, 0); 1731 if (ret < 0) { 1732 error_setg_errno(errp, -ret, "Could not read backing file name"); 1733 goto fail; 1734 } 1735 s->image_backing_file[len] = '\0'; 1736 1737 /* 1738 * Update only when something has changed. This function is called by 1739 * qcow2_co_invalidate_cache(), and we do not want to reset 1740 * auto_backing_file unless necessary. 1741 */ 1742 if (!g_str_equal(s->image_backing_file, bs->backing_file)) { 1743 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1744 s->image_backing_file); 1745 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 1746 s->image_backing_file); 1747 } 1748 } 1749 1750 /* 1751 * Internal snapshots; skip reading them in check mode, because 1752 * we do not need them then, and we do not want to abort because 1753 * of a broken table. 1754 */ 1755 if (!(flags & BDRV_O_CHECK)) { 1756 s->snapshots_offset = header.snapshots_offset; 1757 s->nb_snapshots = header.nb_snapshots; 1758 1759 ret = qcow2_read_snapshots(bs, errp); 1760 if (ret < 0) { 1761 goto fail; 1762 } 1763 } 1764 1765 /* Clear unknown autoclear feature bits */ 1766 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1767 update_header = update_header && bdrv_is_writable(bs); 1768 if (update_header) { 1769 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1770 } 1771 1772 /* == Handle persistent dirty bitmaps == 1773 * 1774 * We want load dirty bitmaps in three cases: 1775 * 1776 * 1. Normal open of the disk in active mode, not related to invalidation 1777 * after migration. 1778 * 1779 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1780 * bitmaps are _not_ migrating through migration channel, i.e. 1781 * 'dirty-bitmaps' capability is disabled. 1782 * 1783 * 3. Invalidation of source vm after failed or canceled migration. 1784 * This is a very interesting case. There are two possible types of 1785 * bitmaps: 1786 * 1787 * A. Stored on inactivation and removed. They should be loaded from the 1788 * image. 1789 * 1790 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1791 * the migration channel (with dirty-bitmaps capability). 1792 * 1793 * On the other hand, there are two possible sub-cases: 1794 * 1795 * 3.1 disk was changed by somebody else while were inactive. In this 1796 * case all in-RAM dirty bitmaps (both persistent and not) are 1797 * definitely invalid. And we don't have any method to determine 1798 * this. 1799 * 1800 * Simple and safe thing is to just drop all the bitmaps of type B on 1801 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1802 * 1803 * On the other hand, resuming source vm, if disk was already changed 1804 * is a bad thing anyway: not only bitmaps, the whole vm state is 1805 * out of sync with disk. 1806 * 1807 * This means, that user or management tool, who for some reason 1808 * decided to resume source vm, after disk was already changed by 1809 * target vm, should at least drop all dirty bitmaps by hand. 1810 * 1811 * So, we can ignore this case for now, but TODO: "generation" 1812 * extension for qcow2, to determine, that image was changed after 1813 * last inactivation. And if it is changed, we will drop (or at least 1814 * mark as 'invalid' all the bitmaps of type B, both persistent 1815 * and not). 1816 * 1817 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1818 * to disk ('dirty-bitmaps' capability disabled), or not saved 1819 * ('dirty-bitmaps' capability enabled), but we don't need to care 1820 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1821 * and not stored has flag IN_USE=1 in the image and will be skipped 1822 * on loading. 1823 * 1824 * One remaining possible case when we don't want load bitmaps: 1825 * 1826 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1827 * will be loaded on invalidation, no needs try loading them before) 1828 */ 1829 1830 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1831 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1832 bool header_updated; 1833 if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) { 1834 ret = -EINVAL; 1835 goto fail; 1836 } 1837 1838 update_header = update_header && !header_updated; 1839 } 1840 1841 if (update_header) { 1842 ret = qcow2_update_header(bs); 1843 if (ret < 0) { 1844 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1845 goto fail; 1846 } 1847 } 1848 1849 bs->supported_zero_flags = header.version >= 3 ? 1850 BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; 1851 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; 1852 1853 /* Repair image if dirty */ 1854 if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) && 1855 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1856 BdrvCheckResult result = {0}; 1857 1858 ret = qcow2_co_check_locked(bs, &result, 1859 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1860 if (ret < 0 || result.check_errors) { 1861 if (ret >= 0) { 1862 ret = -EIO; 1863 } 1864 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1865 goto fail; 1866 } 1867 } 1868 1869 #ifdef DEBUG_ALLOC 1870 { 1871 BdrvCheckResult result = {0}; 1872 qcow2_check_refcounts(bs, &result, 0); 1873 } 1874 #endif 1875 1876 qemu_co_queue_init(&s->thread_task_queue); 1877 1878 return ret; 1879 1880 fail: 1881 g_free(s->image_data_file); 1882 if (open_data_file && has_data_file(bs)) { 1883 bdrv_graph_co_rdunlock(); 1884 bdrv_co_unref_child(bs, s->data_file); 1885 bdrv_graph_co_rdlock(); 1886 s->data_file = NULL; 1887 } 1888 g_free(s->unknown_header_fields); 1889 cleanup_unknown_header_ext(bs); 1890 qcow2_free_snapshots(bs); 1891 qcow2_refcount_close(bs); 1892 qemu_vfree(s->l1_table); 1893 /* else pre-write overlap checks in cache_destroy may crash */ 1894 s->l1_table = NULL; 1895 cache_clean_timer_del(bs); 1896 if (s->l2_table_cache) { 1897 qcow2_cache_destroy(s->l2_table_cache); 1898 } 1899 if (s->refcount_block_cache) { 1900 qcow2_cache_destroy(s->refcount_block_cache); 1901 } 1902 qcrypto_block_free(s->crypto); 1903 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1904 return ret; 1905 } 1906 1907 typedef struct QCow2OpenCo { 1908 BlockDriverState *bs; 1909 QDict *options; 1910 int flags; 1911 Error **errp; 1912 int ret; 1913 } QCow2OpenCo; 1914 1915 static void coroutine_fn qcow2_open_entry(void *opaque) 1916 { 1917 QCow2OpenCo *qoc = opaque; 1918 BDRVQcow2State *s = qoc->bs->opaque; 1919 1920 GRAPH_RDLOCK_GUARD(); 1921 1922 qemu_co_mutex_lock(&s->lock); 1923 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true, 1924 qoc->errp); 1925 qemu_co_mutex_unlock(&s->lock); 1926 1927 aio_wait_kick(); 1928 } 1929 1930 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1931 Error **errp) 1932 { 1933 BDRVQcow2State *s = bs->opaque; 1934 QCow2OpenCo qoc = { 1935 .bs = bs, 1936 .options = options, 1937 .flags = flags, 1938 .errp = errp, 1939 .ret = -EINPROGRESS 1940 }; 1941 int ret; 1942 1943 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 1944 if (ret < 0) { 1945 return ret; 1946 } 1947 1948 /* Initialise locks */ 1949 qemu_co_mutex_init(&s->lock); 1950 1951 assert(!qemu_in_coroutine()); 1952 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1953 1954 aio_co_enter(bdrv_get_aio_context(bs), 1955 qemu_coroutine_create(qcow2_open_entry, &qoc)); 1956 AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS); 1957 1958 return qoc.ret; 1959 } 1960 1961 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1962 { 1963 BDRVQcow2State *s = bs->opaque; 1964 1965 if (bs->encrypted) { 1966 /* Encryption works on a sector granularity */ 1967 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1968 } 1969 bs->bl.pwrite_zeroes_alignment = s->subcluster_size; 1970 bs->bl.pdiscard_alignment = s->cluster_size; 1971 } 1972 1973 static int GRAPH_UNLOCKED 1974 qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue, 1975 Error **errp) 1976 { 1977 BDRVQcow2State *s = state->bs->opaque; 1978 Qcow2ReopenState *r; 1979 int ret; 1980 1981 GLOBAL_STATE_CODE(); 1982 GRAPH_RDLOCK_GUARD_MAINLOOP(); 1983 1984 r = g_new0(Qcow2ReopenState, 1); 1985 state->opaque = r; 1986 1987 ret = qcow2_update_options_prepare(state->bs, r, state->options, 1988 state->flags, errp); 1989 if (ret < 0) { 1990 goto fail; 1991 } 1992 1993 /* We need to write out any unwritten data if we reopen read-only. */ 1994 if ((state->flags & BDRV_O_RDWR) == 0) { 1995 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 1996 if (ret < 0) { 1997 goto fail; 1998 } 1999 2000 ret = bdrv_flush(state->bs); 2001 if (ret < 0) { 2002 goto fail; 2003 } 2004 2005 ret = qcow2_mark_clean(state->bs); 2006 if (ret < 0) { 2007 goto fail; 2008 } 2009 } 2010 2011 /* 2012 * Without an external data file, s->data_file points to the same BdrvChild 2013 * as bs->file. It needs to be resynced after reopen because bs->file may 2014 * be changed. We can't use it in the meantime. 2015 */ 2016 if (!has_data_file(state->bs)) { 2017 assert(s->data_file == state->bs->file); 2018 s->data_file = NULL; 2019 } 2020 2021 return 0; 2022 2023 fail: 2024 qcow2_update_options_abort(state->bs, r); 2025 g_free(r); 2026 return ret; 2027 } 2028 2029 static void qcow2_reopen_commit(BDRVReopenState *state) 2030 { 2031 BDRVQcow2State *s = state->bs->opaque; 2032 2033 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2034 2035 qcow2_update_options_commit(state->bs, state->opaque); 2036 if (!s->data_file) { 2037 /* 2038 * If we don't have an external data file, s->data_file was cleared by 2039 * qcow2_reopen_prepare() and needs to be updated. 2040 */ 2041 s->data_file = state->bs->file; 2042 } 2043 g_free(state->opaque); 2044 } 2045 2046 static void qcow2_reopen_commit_post(BDRVReopenState *state) 2047 { 2048 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2049 2050 if (state->flags & BDRV_O_RDWR) { 2051 Error *local_err = NULL; 2052 2053 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { 2054 /* 2055 * This is not fatal, bitmaps just left read-only, so all following 2056 * writes will fail. User can remove read-only bitmaps to unblock 2057 * writes or retry reopen. 2058 */ 2059 error_reportf_err(local_err, 2060 "%s: Failed to make dirty bitmaps writable: ", 2061 bdrv_get_node_name(state->bs)); 2062 } 2063 } 2064 } 2065 2066 static void qcow2_reopen_abort(BDRVReopenState *state) 2067 { 2068 BDRVQcow2State *s = state->bs->opaque; 2069 2070 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2071 2072 if (!s->data_file) { 2073 /* 2074 * If we don't have an external data file, s->data_file was cleared by 2075 * qcow2_reopen_prepare() and needs to be restored. 2076 */ 2077 s->data_file = state->bs->file; 2078 } 2079 qcow2_update_options_abort(state->bs, state->opaque); 2080 g_free(state->opaque); 2081 } 2082 2083 static void qcow2_join_options(QDict *options, QDict *old_options) 2084 { 2085 bool has_new_overlap_template = 2086 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 2087 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 2088 bool has_new_total_cache_size = 2089 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 2090 bool has_all_cache_options; 2091 2092 /* New overlap template overrides all old overlap options */ 2093 if (has_new_overlap_template) { 2094 qdict_del(old_options, QCOW2_OPT_OVERLAP); 2095 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 2096 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 2097 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 2098 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 2099 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 2100 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 2101 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 2102 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 2103 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 2104 } 2105 2106 /* New total cache size overrides all old options */ 2107 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 2108 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 2109 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2110 } 2111 2112 qdict_join(options, old_options, false); 2113 2114 /* 2115 * If after merging all cache size options are set, an old total size is 2116 * overwritten. Do keep all options, however, if all three are new. The 2117 * resulting error message is what we want to happen. 2118 */ 2119 has_all_cache_options = 2120 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 2121 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 2122 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2123 2124 if (has_all_cache_options && !has_new_total_cache_size) { 2125 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 2126 } 2127 } 2128 2129 static int coroutine_fn GRAPH_RDLOCK 2130 qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, 2131 int64_t count, int64_t *pnum, int64_t *map, 2132 BlockDriverState **file) 2133 { 2134 BDRVQcow2State *s = bs->opaque; 2135 uint64_t host_offset; 2136 unsigned int bytes; 2137 QCow2SubclusterType type; 2138 int ret, status = 0; 2139 2140 qemu_co_mutex_lock(&s->lock); 2141 2142 if (!s->metadata_preallocation_checked) { 2143 ret = qcow2_detect_metadata_preallocation(bs); 2144 s->metadata_preallocation = (ret == 1); 2145 s->metadata_preallocation_checked = true; 2146 } 2147 2148 bytes = MIN(INT_MAX, count); 2149 ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type); 2150 qemu_co_mutex_unlock(&s->lock); 2151 if (ret < 0) { 2152 return ret; 2153 } 2154 2155 *pnum = bytes; 2156 2157 if ((type == QCOW2_SUBCLUSTER_NORMAL || 2158 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2159 type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) { 2160 *map = host_offset; 2161 *file = s->data_file->bs; 2162 status |= BDRV_BLOCK_OFFSET_VALID; 2163 } 2164 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2165 type == QCOW2_SUBCLUSTER_ZERO_ALLOC) { 2166 status |= BDRV_BLOCK_ZERO; 2167 } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 2168 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) { 2169 status |= BDRV_BLOCK_DATA; 2170 } 2171 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && 2172 (status & BDRV_BLOCK_OFFSET_VALID)) 2173 { 2174 status |= BDRV_BLOCK_RECURSE; 2175 } 2176 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 2177 status |= BDRV_BLOCK_COMPRESSED; 2178 } 2179 return status; 2180 } 2181 2182 static int coroutine_fn GRAPH_RDLOCK 2183 qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2) 2184 { 2185 int ret = 0; 2186 QCowL2Meta *l2meta = *pl2meta; 2187 2188 while (l2meta != NULL) { 2189 QCowL2Meta *next; 2190 2191 if (link_l2) { 2192 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 2193 if (ret) { 2194 goto out; 2195 } 2196 } else { 2197 qcow2_alloc_cluster_abort(bs, l2meta); 2198 } 2199 2200 /* Take the request off the list of running requests */ 2201 QLIST_REMOVE(l2meta, next_in_flight); 2202 2203 qemu_co_queue_restart_all(&l2meta->dependent_requests); 2204 2205 next = l2meta->next; 2206 g_free(l2meta); 2207 l2meta = next; 2208 } 2209 out: 2210 *pl2meta = l2meta; 2211 return ret; 2212 } 2213 2214 static int coroutine_fn GRAPH_RDLOCK 2215 qcow2_co_preadv_encrypted(BlockDriverState *bs, 2216 uint64_t host_offset, 2217 uint64_t offset, 2218 uint64_t bytes, 2219 QEMUIOVector *qiov, 2220 uint64_t qiov_offset) 2221 { 2222 int ret; 2223 BDRVQcow2State *s = bs->opaque; 2224 uint8_t *buf; 2225 2226 assert(bs->encrypted && s->crypto); 2227 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2228 2229 /* 2230 * For encrypted images, read everything into a temporary 2231 * contiguous buffer on which the AES functions can work. 2232 * Also, decryption in a separate buffer is better as it 2233 * prevents the guest from learning information about the 2234 * encrypted nature of the virtual disk. 2235 */ 2236 2237 buf = qemu_try_blockalign(s->data_file->bs, bytes); 2238 if (buf == NULL) { 2239 return -ENOMEM; 2240 } 2241 2242 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2243 ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0); 2244 if (ret < 0) { 2245 goto fail; 2246 } 2247 2248 if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0) 2249 { 2250 ret = -EIO; 2251 goto fail; 2252 } 2253 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); 2254 2255 fail: 2256 qemu_vfree(buf); 2257 2258 return ret; 2259 } 2260 2261 typedef struct Qcow2AioTask { 2262 AioTask task; 2263 2264 BlockDriverState *bs; 2265 QCow2SubclusterType subcluster_type; /* only for read */ 2266 uint64_t host_offset; /* or l2_entry for compressed read */ 2267 uint64_t offset; 2268 uint64_t bytes; 2269 QEMUIOVector *qiov; 2270 uint64_t qiov_offset; 2271 QCowL2Meta *l2meta; /* only for write */ 2272 } Qcow2AioTask; 2273 2274 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); 2275 static coroutine_fn int qcow2_add_task(BlockDriverState *bs, 2276 AioTaskPool *pool, 2277 AioTaskFunc func, 2278 QCow2SubclusterType subcluster_type, 2279 uint64_t host_offset, 2280 uint64_t offset, 2281 uint64_t bytes, 2282 QEMUIOVector *qiov, 2283 size_t qiov_offset, 2284 QCowL2Meta *l2meta) 2285 { 2286 Qcow2AioTask local_task; 2287 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; 2288 2289 *task = (Qcow2AioTask) { 2290 .task.func = func, 2291 .bs = bs, 2292 .subcluster_type = subcluster_type, 2293 .qiov = qiov, 2294 .host_offset = host_offset, 2295 .offset = offset, 2296 .bytes = bytes, 2297 .qiov_offset = qiov_offset, 2298 .l2meta = l2meta, 2299 }; 2300 2301 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, 2302 func == qcow2_co_preadv_task_entry ? "read" : "write", 2303 subcluster_type, host_offset, offset, bytes, 2304 qiov, qiov_offset); 2305 2306 if (!pool) { 2307 return func(&task->task); 2308 } 2309 2310 aio_task_pool_start_task(pool, &task->task); 2311 2312 return 0; 2313 } 2314 2315 static int coroutine_fn GRAPH_RDLOCK 2316 qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type, 2317 uint64_t host_offset, uint64_t offset, uint64_t bytes, 2318 QEMUIOVector *qiov, size_t qiov_offset) 2319 { 2320 BDRVQcow2State *s = bs->opaque; 2321 2322 switch (subc_type) { 2323 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 2324 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 2325 /* Both zero types are handled in qcow2_co_preadv_part */ 2326 g_assert_not_reached(); 2327 2328 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 2329 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 2330 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ 2331 2332 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2333 return bdrv_co_preadv_part(bs->backing, offset, bytes, 2334 qiov, qiov_offset, 0); 2335 2336 case QCOW2_SUBCLUSTER_COMPRESSED: 2337 return qcow2_co_preadv_compressed(bs, host_offset, 2338 offset, bytes, qiov, qiov_offset); 2339 2340 case QCOW2_SUBCLUSTER_NORMAL: 2341 if (bs->encrypted) { 2342 return qcow2_co_preadv_encrypted(bs, host_offset, 2343 offset, bytes, qiov, qiov_offset); 2344 } 2345 2346 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2347 return bdrv_co_preadv_part(s->data_file, host_offset, 2348 bytes, qiov, qiov_offset, 0); 2349 2350 default: 2351 g_assert_not_reached(); 2352 } 2353 2354 g_assert_not_reached(); 2355 } 2356 2357 /* 2358 * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds 2359 * the graph lock and keeps it until this coroutine has terminated. 2360 */ 2361 static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task) 2362 { 2363 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2364 2365 assert(!t->l2meta); 2366 2367 return qcow2_co_preadv_task(t->bs, t->subcluster_type, 2368 t->host_offset, t->offset, t->bytes, 2369 t->qiov, t->qiov_offset); 2370 } 2371 2372 static int coroutine_fn GRAPH_RDLOCK 2373 qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2374 QEMUIOVector *qiov, size_t qiov_offset, 2375 BdrvRequestFlags flags) 2376 { 2377 BDRVQcow2State *s = bs->opaque; 2378 int ret = 0; 2379 unsigned int cur_bytes; /* number of bytes in current iteration */ 2380 uint64_t host_offset = 0; 2381 QCow2SubclusterType type; 2382 AioTaskPool *aio = NULL; 2383 2384 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2385 /* prepare next request */ 2386 cur_bytes = MIN(bytes, INT_MAX); 2387 if (s->crypto) { 2388 cur_bytes = MIN(cur_bytes, 2389 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2390 } 2391 2392 qemu_co_mutex_lock(&s->lock); 2393 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, 2394 &host_offset, &type); 2395 qemu_co_mutex_unlock(&s->lock); 2396 if (ret < 0) { 2397 goto out; 2398 } 2399 2400 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2401 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2402 (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) || 2403 (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing)) 2404 { 2405 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2406 } else { 2407 if (!aio && cur_bytes != bytes) { 2408 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2409 } 2410 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type, 2411 host_offset, offset, cur_bytes, 2412 qiov, qiov_offset, NULL); 2413 if (ret < 0) { 2414 goto out; 2415 } 2416 } 2417 2418 bytes -= cur_bytes; 2419 offset += cur_bytes; 2420 qiov_offset += cur_bytes; 2421 } 2422 2423 out: 2424 if (aio) { 2425 aio_task_pool_wait_all(aio); 2426 if (ret == 0) { 2427 ret = aio_task_pool_status(aio); 2428 } 2429 g_free(aio); 2430 } 2431 2432 return ret; 2433 } 2434 2435 /* Check if it's possible to merge a write request with the writing of 2436 * the data from the COW regions */ 2437 static bool merge_cow(uint64_t offset, unsigned bytes, 2438 QEMUIOVector *qiov, size_t qiov_offset, 2439 QCowL2Meta *l2meta) 2440 { 2441 QCowL2Meta *m; 2442 2443 for (m = l2meta; m != NULL; m = m->next) { 2444 /* If both COW regions are empty then there's nothing to merge */ 2445 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2446 continue; 2447 } 2448 2449 /* If COW regions are handled already, skip this too */ 2450 if (m->skip_cow) { 2451 continue; 2452 } 2453 2454 /* 2455 * The write request should start immediately after the first 2456 * COW region. This does not always happen because the area 2457 * touched by the request can be larger than the one defined 2458 * by @m (a single request can span an area consisting of a 2459 * mix of previously unallocated and allocated clusters, that 2460 * is why @l2meta is a list). 2461 */ 2462 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2463 /* In this case the request starts before this region */ 2464 assert(offset < l2meta_cow_start(m)); 2465 assert(m->cow_start.nb_bytes == 0); 2466 continue; 2467 } 2468 2469 /* The write request should end immediately before the second 2470 * COW region (see above for why it does not always happen) */ 2471 if (m->offset + m->cow_end.offset != offset + bytes) { 2472 assert(offset + bytes > m->offset + m->cow_end.offset); 2473 assert(m->cow_end.nb_bytes == 0); 2474 continue; 2475 } 2476 2477 /* Make sure that adding both COW regions to the QEMUIOVector 2478 * does not exceed IOV_MAX */ 2479 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { 2480 continue; 2481 } 2482 2483 m->data_qiov = qiov; 2484 m->data_qiov_offset = qiov_offset; 2485 return true; 2486 } 2487 2488 return false; 2489 } 2490 2491 /* 2492 * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error. 2493 * Note that returning 0 does not guarantee non-zero data. 2494 */ 2495 static int coroutine_fn GRAPH_RDLOCK 2496 is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) 2497 { 2498 /* 2499 * This check is designed for optimization shortcut so it must be 2500 * efficient. 2501 * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is 2502 * faster (but not as accurate and can result in false negatives). 2503 */ 2504 int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset, 2505 m->cow_start.nb_bytes); 2506 if (ret <= 0) { 2507 return ret; 2508 } 2509 2510 return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset, 2511 m->cow_end.nb_bytes); 2512 } 2513 2514 static int coroutine_fn GRAPH_RDLOCK 2515 handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) 2516 { 2517 BDRVQcow2State *s = bs->opaque; 2518 QCowL2Meta *m; 2519 2520 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { 2521 return 0; 2522 } 2523 2524 if (bs->encrypted) { 2525 return 0; 2526 } 2527 2528 for (m = l2meta; m != NULL; m = m->next) { 2529 int ret; 2530 uint64_t start_offset = m->alloc_offset + m->cow_start.offset; 2531 unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes - 2532 m->cow_start.offset; 2533 2534 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { 2535 continue; 2536 } 2537 2538 ret = is_zero_cow(bs, m); 2539 if (ret < 0) { 2540 return ret; 2541 } else if (ret == 0) { 2542 continue; 2543 } 2544 2545 /* 2546 * instead of writing zero COW buffers, 2547 * efficiently zero out the whole clusters 2548 */ 2549 2550 ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes, 2551 true); 2552 if (ret < 0) { 2553 return ret; 2554 } 2555 2556 BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); 2557 ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes, 2558 BDRV_REQ_NO_FALLBACK); 2559 if (ret < 0) { 2560 if (ret != -ENOTSUP && ret != -EAGAIN) { 2561 return ret; 2562 } 2563 continue; 2564 } 2565 2566 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); 2567 m->skip_cow = true; 2568 } 2569 return 0; 2570 } 2571 2572 /* 2573 * qcow2_co_pwritev_task 2574 * Called with s->lock unlocked 2575 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must 2576 * not use it somehow after qcow2_co_pwritev_task() call 2577 */ 2578 static coroutine_fn GRAPH_RDLOCK 2579 int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset, 2580 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, 2581 uint64_t qiov_offset, QCowL2Meta *l2meta) 2582 { 2583 int ret; 2584 BDRVQcow2State *s = bs->opaque; 2585 void *crypt_buf = NULL; 2586 QEMUIOVector encrypted_qiov; 2587 2588 if (bs->encrypted) { 2589 assert(s->crypto); 2590 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2591 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); 2592 if (crypt_buf == NULL) { 2593 ret = -ENOMEM; 2594 goto out_unlocked; 2595 } 2596 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); 2597 2598 if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) { 2599 ret = -EIO; 2600 goto out_unlocked; 2601 } 2602 2603 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); 2604 qiov = &encrypted_qiov; 2605 qiov_offset = 0; 2606 } 2607 2608 /* Try to efficiently initialize the physical space with zeroes */ 2609 ret = handle_alloc_space(bs, l2meta); 2610 if (ret < 0) { 2611 goto out_unlocked; 2612 } 2613 2614 /* 2615 * If we need to do COW, check if it's possible to merge the 2616 * writing of the guest data together with that of the COW regions. 2617 * If it's not possible (or not necessary) then write the 2618 * guest data now. 2619 */ 2620 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { 2621 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 2622 trace_qcow2_writev_data(qemu_coroutine_self(), host_offset); 2623 ret = bdrv_co_pwritev_part(s->data_file, host_offset, 2624 bytes, qiov, qiov_offset, 0); 2625 if (ret < 0) { 2626 goto out_unlocked; 2627 } 2628 } 2629 2630 qemu_co_mutex_lock(&s->lock); 2631 2632 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2633 goto out_locked; 2634 2635 out_unlocked: 2636 qemu_co_mutex_lock(&s->lock); 2637 2638 out_locked: 2639 qcow2_handle_l2meta(bs, &l2meta, false); 2640 qemu_co_mutex_unlock(&s->lock); 2641 2642 qemu_vfree(crypt_buf); 2643 2644 return ret; 2645 } 2646 2647 /* 2648 * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds 2649 * the graph lock and keeps it until this coroutine has terminated. 2650 */ 2651 static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task) 2652 { 2653 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2654 2655 assert(!t->subcluster_type); 2656 2657 return qcow2_co_pwritev_task(t->bs, t->host_offset, 2658 t->offset, t->bytes, t->qiov, t->qiov_offset, 2659 t->l2meta); 2660 } 2661 2662 static int coroutine_fn GRAPH_RDLOCK 2663 qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2664 QEMUIOVector *qiov, size_t qiov_offset, 2665 BdrvRequestFlags flags) 2666 { 2667 BDRVQcow2State *s = bs->opaque; 2668 int offset_in_cluster; 2669 int ret; 2670 unsigned int cur_bytes; /* number of sectors in current iteration */ 2671 uint64_t host_offset; 2672 QCowL2Meta *l2meta = NULL; 2673 AioTaskPool *aio = NULL; 2674 2675 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2676 2677 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2678 2679 l2meta = NULL; 2680 2681 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2682 offset_in_cluster = offset_into_cluster(s, offset); 2683 cur_bytes = MIN(bytes, INT_MAX); 2684 if (bs->encrypted) { 2685 cur_bytes = MIN(cur_bytes, 2686 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2687 - offset_in_cluster); 2688 } 2689 2690 qemu_co_mutex_lock(&s->lock); 2691 2692 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 2693 &host_offset, &l2meta); 2694 if (ret < 0) { 2695 goto out_locked; 2696 } 2697 2698 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, 2699 cur_bytes, true); 2700 if (ret < 0) { 2701 goto out_locked; 2702 } 2703 2704 qemu_co_mutex_unlock(&s->lock); 2705 2706 if (!aio && cur_bytes != bytes) { 2707 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2708 } 2709 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, 2710 host_offset, offset, 2711 cur_bytes, qiov, qiov_offset, l2meta); 2712 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ 2713 if (ret < 0) { 2714 goto fail_nometa; 2715 } 2716 2717 bytes -= cur_bytes; 2718 offset += cur_bytes; 2719 qiov_offset += cur_bytes; 2720 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2721 } 2722 ret = 0; 2723 2724 qemu_co_mutex_lock(&s->lock); 2725 2726 out_locked: 2727 qcow2_handle_l2meta(bs, &l2meta, false); 2728 2729 qemu_co_mutex_unlock(&s->lock); 2730 2731 fail_nometa: 2732 if (aio) { 2733 aio_task_pool_wait_all(aio); 2734 if (ret == 0) { 2735 ret = aio_task_pool_status(aio); 2736 } 2737 g_free(aio); 2738 } 2739 2740 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2741 2742 return ret; 2743 } 2744 2745 static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs) 2746 { 2747 BDRVQcow2State *s = bs->opaque; 2748 int ret, result = 0; 2749 Error *local_err = NULL; 2750 2751 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); 2752 if (local_err != NULL) { 2753 result = -EINVAL; 2754 error_reportf_err(local_err, "Lost persistent bitmaps during " 2755 "inactivation of node '%s': ", 2756 bdrv_get_device_or_node_name(bs)); 2757 } 2758 2759 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2760 if (ret) { 2761 result = ret; 2762 error_report("Failed to flush the L2 table cache: %s", 2763 strerror(-ret)); 2764 } 2765 2766 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2767 if (ret) { 2768 result = ret; 2769 error_report("Failed to flush the refcount block cache: %s", 2770 strerror(-ret)); 2771 } 2772 2773 if (result == 0) { 2774 qcow2_mark_clean(bs); 2775 } 2776 2777 return result; 2778 } 2779 2780 static void coroutine_mixed_fn GRAPH_RDLOCK 2781 qcow2_do_close(BlockDriverState *bs, bool close_data_file) 2782 { 2783 BDRVQcow2State *s = bs->opaque; 2784 qemu_vfree(s->l1_table); 2785 /* else pre-write overlap checks in cache_destroy may crash */ 2786 s->l1_table = NULL; 2787 2788 if (!(s->flags & BDRV_O_INACTIVE)) { 2789 qcow2_inactivate(bs); 2790 } 2791 2792 cache_clean_timer_del(bs); 2793 qcow2_cache_destroy(s->l2_table_cache); 2794 qcow2_cache_destroy(s->refcount_block_cache); 2795 2796 qcrypto_block_free(s->crypto); 2797 s->crypto = NULL; 2798 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 2799 2800 g_free(s->unknown_header_fields); 2801 cleanup_unknown_header_ext(bs); 2802 2803 g_free(s->image_data_file); 2804 g_free(s->image_backing_file); 2805 g_free(s->image_backing_format); 2806 2807 if (close_data_file && has_data_file(bs)) { 2808 GLOBAL_STATE_CODE(); 2809 bdrv_graph_rdunlock_main_loop(); 2810 bdrv_graph_wrlock(); 2811 bdrv_unref_child(bs, s->data_file); 2812 bdrv_graph_wrunlock(); 2813 s->data_file = NULL; 2814 bdrv_graph_rdlock_main_loop(); 2815 } 2816 2817 qcow2_refcount_close(bs); 2818 qcow2_free_snapshots(bs); 2819 } 2820 2821 static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs) 2822 { 2823 GLOBAL_STATE_CODE(); 2824 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2825 2826 qcow2_do_close(bs, true); 2827 } 2828 2829 static void coroutine_fn GRAPH_RDLOCK 2830 qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp) 2831 { 2832 ERRP_GUARD(); 2833 BDRVQcow2State *s = bs->opaque; 2834 BdrvChild *data_file; 2835 int flags = s->flags; 2836 QCryptoBlock *crypto = NULL; 2837 QDict *options; 2838 int ret; 2839 2840 /* 2841 * Backing files are read-only which makes all of their metadata immutable, 2842 * that means we don't have to worry about reopening them here. 2843 */ 2844 2845 crypto = s->crypto; 2846 s->crypto = NULL; 2847 2848 /* 2849 * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it, 2850 * and then prevent qcow2_do_open() from opening it), because this function 2851 * runs in the I/O path and as such we must not invoke global-state 2852 * functions like bdrv_unref_child() and bdrv_open_child(). 2853 */ 2854 2855 qcow2_do_close(bs, false); 2856 2857 data_file = s->data_file; 2858 memset(s, 0, sizeof(BDRVQcow2State)); 2859 s->data_file = data_file; 2860 2861 options = qdict_clone_shallow(bs->options); 2862 2863 flags &= ~BDRV_O_INACTIVE; 2864 qemu_co_mutex_lock(&s->lock); 2865 ret = qcow2_do_open(bs, options, flags, false, errp); 2866 qemu_co_mutex_unlock(&s->lock); 2867 qobject_unref(options); 2868 if (ret < 0) { 2869 error_prepend(errp, "Could not reopen qcow2 layer: "); 2870 bs->drv = NULL; 2871 return; 2872 } 2873 2874 s->crypto = crypto; 2875 } 2876 2877 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2878 size_t len, size_t buflen) 2879 { 2880 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2881 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2882 2883 if (buflen < ext_len) { 2884 return -ENOSPC; 2885 } 2886 2887 *ext_backing_fmt = (QCowExtension) { 2888 .magic = cpu_to_be32(magic), 2889 .len = cpu_to_be32(len), 2890 }; 2891 2892 if (len) { 2893 memcpy(buf + sizeof(QCowExtension), s, len); 2894 } 2895 2896 return ext_len; 2897 } 2898 2899 /* 2900 * Updates the qcow2 header, including the variable length parts of it, i.e. 2901 * the backing file name and all extensions. qcow2 was not designed to allow 2902 * such changes, so if we run out of space (we can only use the first cluster) 2903 * this function may fail. 2904 * 2905 * Returns 0 on success, -errno in error cases. 2906 */ 2907 int qcow2_update_header(BlockDriverState *bs) 2908 { 2909 BDRVQcow2State *s = bs->opaque; 2910 QCowHeader *header; 2911 char *buf; 2912 size_t buflen = s->cluster_size; 2913 int ret; 2914 uint64_t total_size; 2915 uint32_t refcount_table_clusters; 2916 size_t header_length; 2917 Qcow2UnknownHeaderExtension *uext; 2918 2919 buf = qemu_blockalign(bs, buflen); 2920 2921 /* Header structure */ 2922 header = (QCowHeader*) buf; 2923 2924 if (buflen < sizeof(*header)) { 2925 ret = -ENOSPC; 2926 goto fail; 2927 } 2928 2929 header_length = sizeof(*header) + s->unknown_header_fields_size; 2930 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2931 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2932 2933 ret = validate_compression_type(s, NULL); 2934 if (ret) { 2935 goto fail; 2936 } 2937 2938 *header = (QCowHeader) { 2939 /* Version 2 fields */ 2940 .magic = cpu_to_be32(QCOW_MAGIC), 2941 .version = cpu_to_be32(s->qcow_version), 2942 .backing_file_offset = 0, 2943 .backing_file_size = 0, 2944 .cluster_bits = cpu_to_be32(s->cluster_bits), 2945 .size = cpu_to_be64(total_size), 2946 .crypt_method = cpu_to_be32(s->crypt_method_header), 2947 .l1_size = cpu_to_be32(s->l1_size), 2948 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2949 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2950 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2951 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2952 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2953 2954 /* Version 3 fields */ 2955 .incompatible_features = cpu_to_be64(s->incompatible_features), 2956 .compatible_features = cpu_to_be64(s->compatible_features), 2957 .autoclear_features = cpu_to_be64(s->autoclear_features), 2958 .refcount_order = cpu_to_be32(s->refcount_order), 2959 .header_length = cpu_to_be32(header_length), 2960 .compression_type = s->compression_type, 2961 }; 2962 2963 /* For older versions, write a shorter header */ 2964 switch (s->qcow_version) { 2965 case 2: 2966 ret = offsetof(QCowHeader, incompatible_features); 2967 break; 2968 case 3: 2969 ret = sizeof(*header); 2970 break; 2971 default: 2972 ret = -EINVAL; 2973 goto fail; 2974 } 2975 2976 buf += ret; 2977 buflen -= ret; 2978 memset(buf, 0, buflen); 2979 2980 /* Preserve any unknown field in the header */ 2981 if (s->unknown_header_fields_size) { 2982 if (buflen < s->unknown_header_fields_size) { 2983 ret = -ENOSPC; 2984 goto fail; 2985 } 2986 2987 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 2988 buf += s->unknown_header_fields_size; 2989 buflen -= s->unknown_header_fields_size; 2990 } 2991 2992 /* Backing file format header extension */ 2993 if (s->image_backing_format) { 2994 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 2995 s->image_backing_format, 2996 strlen(s->image_backing_format), 2997 buflen); 2998 if (ret < 0) { 2999 goto fail; 3000 } 3001 3002 buf += ret; 3003 buflen -= ret; 3004 } 3005 3006 /* External data file header extension */ 3007 if (has_data_file(bs) && s->image_data_file) { 3008 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 3009 s->image_data_file, strlen(s->image_data_file), 3010 buflen); 3011 if (ret < 0) { 3012 goto fail; 3013 } 3014 3015 buf += ret; 3016 buflen -= ret; 3017 } 3018 3019 /* Full disk encryption header pointer extension */ 3020 if (s->crypto_header.offset != 0) { 3021 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 3022 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 3023 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 3024 &s->crypto_header, sizeof(s->crypto_header), 3025 buflen); 3026 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 3027 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 3028 if (ret < 0) { 3029 goto fail; 3030 } 3031 buf += ret; 3032 buflen -= ret; 3033 } 3034 3035 /* 3036 * Feature table. A mere 8 feature names occupies 392 bytes, and 3037 * when coupled with the v3 minimum header of 104 bytes plus the 3038 * 8-byte end-of-extension marker, that would leave only 8 bytes 3039 * for a backing file name in an image with 512-byte clusters. 3040 * Thus, we choose to omit this header for cluster sizes 4k and 3041 * smaller. 3042 */ 3043 if (s->qcow_version >= 3 && s->cluster_size > 4096) { 3044 static const Qcow2Feature features[] = { 3045 { 3046 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3047 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 3048 .name = "dirty bit", 3049 }, 3050 { 3051 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3052 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 3053 .name = "corrupt bit", 3054 }, 3055 { 3056 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3057 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 3058 .name = "external data file", 3059 }, 3060 { 3061 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3062 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, 3063 .name = "compression type", 3064 }, 3065 { 3066 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3067 .bit = QCOW2_INCOMPAT_EXTL2_BITNR, 3068 .name = "extended L2 entries", 3069 }, 3070 { 3071 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 3072 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 3073 .name = "lazy refcounts", 3074 }, 3075 { 3076 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3077 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, 3078 .name = "bitmaps", 3079 }, 3080 { 3081 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3082 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 3083 .name = "raw external data", 3084 }, 3085 }; 3086 3087 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 3088 features, sizeof(features), buflen); 3089 if (ret < 0) { 3090 goto fail; 3091 } 3092 buf += ret; 3093 buflen -= ret; 3094 } 3095 3096 /* Bitmap extension */ 3097 if (s->nb_bitmaps > 0) { 3098 Qcow2BitmapHeaderExt bitmaps_header = { 3099 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 3100 .bitmap_directory_size = 3101 cpu_to_be64(s->bitmap_directory_size), 3102 .bitmap_directory_offset = 3103 cpu_to_be64(s->bitmap_directory_offset) 3104 }; 3105 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 3106 &bitmaps_header, sizeof(bitmaps_header), 3107 buflen); 3108 if (ret < 0) { 3109 goto fail; 3110 } 3111 buf += ret; 3112 buflen -= ret; 3113 } 3114 3115 /* Keep unknown header extensions */ 3116 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 3117 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 3118 if (ret < 0) { 3119 goto fail; 3120 } 3121 3122 buf += ret; 3123 buflen -= ret; 3124 } 3125 3126 /* End of header extensions */ 3127 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 3128 if (ret < 0) { 3129 goto fail; 3130 } 3131 3132 buf += ret; 3133 buflen -= ret; 3134 3135 /* Backing file name */ 3136 if (s->image_backing_file) { 3137 size_t backing_file_len = strlen(s->image_backing_file); 3138 3139 if (buflen < backing_file_len) { 3140 ret = -ENOSPC; 3141 goto fail; 3142 } 3143 3144 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 3145 strncpy(buf, s->image_backing_file, buflen); 3146 3147 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 3148 header->backing_file_size = cpu_to_be32(backing_file_len); 3149 } 3150 3151 /* Write the new header */ 3152 ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0); 3153 if (ret < 0) { 3154 goto fail; 3155 } 3156 3157 ret = 0; 3158 fail: 3159 qemu_vfree(header); 3160 return ret; 3161 } 3162 3163 static int coroutine_fn GRAPH_RDLOCK 3164 qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file, 3165 const char *backing_fmt) 3166 { 3167 BDRVQcow2State *s = bs->opaque; 3168 3169 /* Adding a backing file means that the external data file alone won't be 3170 * enough to make sense of the content */ 3171 if (backing_file && data_file_is_raw(bs)) { 3172 return -EINVAL; 3173 } 3174 3175 if (backing_file && strlen(backing_file) > 1023) { 3176 return -EINVAL; 3177 } 3178 3179 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 3180 backing_file ?: ""); 3181 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 3182 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 3183 3184 g_free(s->image_backing_file); 3185 g_free(s->image_backing_format); 3186 3187 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 3188 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 3189 3190 return qcow2_update_header(bs); 3191 } 3192 3193 static int coroutine_fn GRAPH_RDLOCK 3194 qcow2_set_up_encryption(BlockDriverState *bs, 3195 QCryptoBlockCreateOptions *cryptoopts, 3196 Error **errp) 3197 { 3198 BDRVQcow2State *s = bs->opaque; 3199 QCryptoBlock *crypto = NULL; 3200 int fmt, ret; 3201 3202 switch (cryptoopts->format) { 3203 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 3204 fmt = QCOW_CRYPT_LUKS; 3205 break; 3206 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 3207 fmt = QCOW_CRYPT_AES; 3208 break; 3209 default: 3210 error_setg(errp, "Crypto format not supported in qcow2"); 3211 return -EINVAL; 3212 } 3213 3214 s->crypt_method_header = fmt; 3215 3216 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 3217 qcow2_crypto_hdr_init_func, 3218 qcow2_crypto_hdr_write_func, 3219 bs, 0, errp); 3220 if (!crypto) { 3221 return -EINVAL; 3222 } 3223 3224 ret = qcow2_update_header(bs); 3225 if (ret < 0) { 3226 error_setg_errno(errp, -ret, "Could not write encryption header"); 3227 goto out; 3228 } 3229 3230 ret = 0; 3231 out: 3232 qcrypto_block_free(crypto); 3233 return ret; 3234 } 3235 3236 /** 3237 * Preallocates metadata structures for data clusters between @offset (in the 3238 * guest disk) and @new_length (which is thus generally the new guest disk 3239 * size). 3240 * 3241 * Returns: 0 on success, -errno on failure. 3242 */ 3243 static int coroutine_fn GRAPH_RDLOCK 3244 preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length, 3245 PreallocMode mode, Error **errp) 3246 { 3247 BDRVQcow2State *s = bs->opaque; 3248 uint64_t bytes; 3249 uint64_t host_offset = 0; 3250 int64_t file_length; 3251 unsigned int cur_bytes; 3252 int ret; 3253 QCowL2Meta *meta = NULL, *m; 3254 3255 assert(offset <= new_length); 3256 bytes = new_length - offset; 3257 3258 while (bytes) { 3259 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); 3260 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 3261 &host_offset, &meta); 3262 if (ret < 0) { 3263 error_setg_errno(errp, -ret, "Allocating clusters failed"); 3264 goto out; 3265 } 3266 3267 for (m = meta; m != NULL; m = m->next) { 3268 m->prealloc = true; 3269 } 3270 3271 ret = qcow2_handle_l2meta(bs, &meta, true); 3272 if (ret < 0) { 3273 error_setg_errno(errp, -ret, "Mapping clusters failed"); 3274 goto out; 3275 } 3276 3277 /* TODO Preallocate data if requested */ 3278 3279 bytes -= cur_bytes; 3280 offset += cur_bytes; 3281 } 3282 3283 /* 3284 * It is expected that the image file is large enough to actually contain 3285 * all of the allocated clusters (otherwise we get failing reads after 3286 * EOF). Extend the image to the last allocated sector. 3287 */ 3288 file_length = bdrv_co_getlength(s->data_file->bs); 3289 if (file_length < 0) { 3290 error_setg_errno(errp, -file_length, "Could not get file size"); 3291 ret = file_length; 3292 goto out; 3293 } 3294 3295 if (host_offset + cur_bytes > file_length) { 3296 if (mode == PREALLOC_MODE_METADATA) { 3297 mode = PREALLOC_MODE_OFF; 3298 } 3299 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false, 3300 mode, 0, errp); 3301 if (ret < 0) { 3302 goto out; 3303 } 3304 } 3305 3306 ret = 0; 3307 3308 out: 3309 qcow2_handle_l2meta(bs, &meta, false); 3310 return ret; 3311 } 3312 3313 /* qcow2_refcount_metadata_size: 3314 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 3315 * @cluster_size: size of a cluster, in bytes 3316 * @refcount_order: refcount bits power-of-2 exponent 3317 * @generous_increase: allow for the refcount table to be 1.5x as large as it 3318 * needs to be 3319 * 3320 * Returns: Number of bytes required for refcount blocks and table metadata. 3321 */ 3322 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 3323 int refcount_order, bool generous_increase, 3324 uint64_t *refblock_count) 3325 { 3326 /* 3327 * Every host cluster is reference-counted, including metadata (even 3328 * refcount metadata is recursively included). 3329 * 3330 * An accurate formula for the size of refcount metadata size is difficult 3331 * to derive. An easier method of calculation is finding the fixed point 3332 * where no further refcount blocks or table clusters are required to 3333 * reference count every cluster. 3334 */ 3335 int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE; 3336 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 3337 int64_t table = 0; /* number of refcount table clusters */ 3338 int64_t blocks = 0; /* number of refcount block clusters */ 3339 int64_t last; 3340 int64_t n = 0; 3341 3342 do { 3343 last = n; 3344 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 3345 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 3346 n = clusters + blocks + table; 3347 3348 if (n == last && generous_increase) { 3349 clusters += DIV_ROUND_UP(table, 2); 3350 n = 0; /* force another loop */ 3351 generous_increase = false; 3352 } 3353 } while (n != last); 3354 3355 if (refblock_count) { 3356 *refblock_count = blocks; 3357 } 3358 3359 return (blocks + table) * cluster_size; 3360 } 3361 3362 /** 3363 * qcow2_calc_prealloc_size: 3364 * @total_size: virtual disk size in bytes 3365 * @cluster_size: cluster size in bytes 3366 * @refcount_order: refcount bits power-of-2 exponent 3367 * @extended_l2: true if the image has extended L2 entries 3368 * 3369 * Returns: Total number of bytes required for the fully allocated image 3370 * (including metadata). 3371 */ 3372 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 3373 size_t cluster_size, 3374 int refcount_order, 3375 bool extended_l2) 3376 { 3377 int64_t meta_size = 0; 3378 uint64_t nl1e, nl2e; 3379 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 3380 size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 3381 3382 /* header: 1 cluster */ 3383 meta_size += cluster_size; 3384 3385 /* total size of L2 tables */ 3386 nl2e = aligned_total_size / cluster_size; 3387 nl2e = ROUND_UP(nl2e, cluster_size / l2e_size); 3388 meta_size += nl2e * l2e_size; 3389 3390 /* total size of L1 tables */ 3391 nl1e = nl2e * l2e_size / cluster_size; 3392 nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE); 3393 meta_size += nl1e * L1E_SIZE; 3394 3395 /* total size of refcount table and blocks */ 3396 meta_size += qcow2_refcount_metadata_size( 3397 (meta_size + aligned_total_size) / cluster_size, 3398 cluster_size, refcount_order, false, NULL); 3399 3400 return meta_size + aligned_total_size; 3401 } 3402 3403 static bool validate_cluster_size(size_t cluster_size, bool extended_l2, 3404 Error **errp) 3405 { 3406 int cluster_bits = ctz32(cluster_size); 3407 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 3408 (1 << cluster_bits) != cluster_size) 3409 { 3410 error_setg(errp, "Cluster size must be a power of two between %d and " 3411 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 3412 return false; 3413 } 3414 3415 if (extended_l2) { 3416 unsigned min_cluster_size = 3417 (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER; 3418 if (cluster_size < min_cluster_size) { 3419 error_setg(errp, "Extended L2 entries are only supported with " 3420 "cluster sizes of at least %u bytes", min_cluster_size); 3421 return false; 3422 } 3423 } 3424 3425 return true; 3426 } 3427 3428 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2, 3429 Error **errp) 3430 { 3431 size_t cluster_size; 3432 3433 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 3434 DEFAULT_CLUSTER_SIZE); 3435 if (!validate_cluster_size(cluster_size, extended_l2, errp)) { 3436 return 0; 3437 } 3438 return cluster_size; 3439 } 3440 3441 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 3442 { 3443 char *buf; 3444 int ret; 3445 3446 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 3447 if (!buf) { 3448 ret = 3; /* default */ 3449 } else if (!strcmp(buf, "0.10")) { 3450 ret = 2; 3451 } else if (!strcmp(buf, "1.1")) { 3452 ret = 3; 3453 } else { 3454 error_setg(errp, "Invalid compatibility level: '%s'", buf); 3455 ret = -EINVAL; 3456 } 3457 g_free(buf); 3458 return ret; 3459 } 3460 3461 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 3462 Error **errp) 3463 { 3464 uint64_t refcount_bits; 3465 3466 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 3467 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 3468 error_setg(errp, "Refcount width must be a power of two and may not " 3469 "exceed 64 bits"); 3470 return 0; 3471 } 3472 3473 if (version < 3 && refcount_bits != 16) { 3474 error_setg(errp, "Different refcount widths than 16 bits require " 3475 "compatibility level 1.1 or above (use compat=1.1 or " 3476 "greater)"); 3477 return 0; 3478 } 3479 3480 return refcount_bits; 3481 } 3482 3483 static int coroutine_fn GRAPH_UNLOCKED 3484 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 3485 { 3486 ERRP_GUARD(); 3487 BlockdevCreateOptionsQcow2 *qcow2_opts; 3488 QDict *options; 3489 3490 /* 3491 * Open the image file and write a minimal qcow2 header. 3492 * 3493 * We keep things simple and start with a zero-sized image. We also 3494 * do without refcount blocks or a L1 table for now. We'll fix the 3495 * inconsistency later. 3496 * 3497 * We do need a refcount table because growing the refcount table means 3498 * allocating two new refcount blocks - the second of which would be at 3499 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 3500 * size for any qcow2 image. 3501 */ 3502 BlockBackend *blk = NULL; 3503 BlockDriverState *bs = NULL; 3504 BlockDriverState *data_bs = NULL; 3505 QCowHeader *header; 3506 size_t cluster_size; 3507 int version; 3508 int refcount_order; 3509 uint64_t *refcount_table; 3510 int ret; 3511 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 3512 3513 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 3514 qcow2_opts = &create_options->u.qcow2; 3515 3516 bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp); 3517 if (bs == NULL) { 3518 return -EIO; 3519 } 3520 3521 /* Validate options and set default values */ 3522 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 3523 error_setg(errp, "Image size must be a multiple of %u bytes", 3524 (unsigned) BDRV_SECTOR_SIZE); 3525 ret = -EINVAL; 3526 goto out; 3527 } 3528 3529 if (qcow2_opts->has_version) { 3530 switch (qcow2_opts->version) { 3531 case BLOCKDEV_QCOW2_VERSION_V2: 3532 version = 2; 3533 break; 3534 case BLOCKDEV_QCOW2_VERSION_V3: 3535 version = 3; 3536 break; 3537 default: 3538 g_assert_not_reached(); 3539 } 3540 } else { 3541 version = 3; 3542 } 3543 3544 if (qcow2_opts->has_cluster_size) { 3545 cluster_size = qcow2_opts->cluster_size; 3546 } else { 3547 cluster_size = DEFAULT_CLUSTER_SIZE; 3548 } 3549 3550 if (!qcow2_opts->has_extended_l2) { 3551 qcow2_opts->extended_l2 = false; 3552 } 3553 if (qcow2_opts->extended_l2) { 3554 if (version < 3) { 3555 error_setg(errp, "Extended L2 entries are only supported with " 3556 "compatibility level 1.1 and above (use version=v3 or " 3557 "greater)"); 3558 ret = -EINVAL; 3559 goto out; 3560 } 3561 } 3562 3563 if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) { 3564 ret = -EINVAL; 3565 goto out; 3566 } 3567 3568 if (!qcow2_opts->has_preallocation) { 3569 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3570 } 3571 if (qcow2_opts->backing_file && 3572 qcow2_opts->preallocation != PREALLOC_MODE_OFF && 3573 !qcow2_opts->extended_l2) 3574 { 3575 error_setg(errp, "Backing file and preallocation can only be used at " 3576 "the same time if extended_l2 is on"); 3577 ret = -EINVAL; 3578 goto out; 3579 } 3580 if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) { 3581 error_setg(errp, "Backing format cannot be used without backing file"); 3582 ret = -EINVAL; 3583 goto out; 3584 } 3585 3586 if (!qcow2_opts->has_lazy_refcounts) { 3587 qcow2_opts->lazy_refcounts = false; 3588 } 3589 if (version < 3 && qcow2_opts->lazy_refcounts) { 3590 error_setg(errp, "Lazy refcounts only supported with compatibility " 3591 "level 1.1 and above (use version=v3 or greater)"); 3592 ret = -EINVAL; 3593 goto out; 3594 } 3595 3596 if (!qcow2_opts->has_refcount_bits) { 3597 qcow2_opts->refcount_bits = 16; 3598 } 3599 if (qcow2_opts->refcount_bits > 64 || 3600 !is_power_of_2(qcow2_opts->refcount_bits)) 3601 { 3602 error_setg(errp, "Refcount width must be a power of two and may not " 3603 "exceed 64 bits"); 3604 ret = -EINVAL; 3605 goto out; 3606 } 3607 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3608 error_setg(errp, "Different refcount widths than 16 bits require " 3609 "compatibility level 1.1 or above (use version=v3 or " 3610 "greater)"); 3611 ret = -EINVAL; 3612 goto out; 3613 } 3614 refcount_order = ctz32(qcow2_opts->refcount_bits); 3615 3616 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3617 error_setg(errp, "data-file-raw requires data-file"); 3618 ret = -EINVAL; 3619 goto out; 3620 } 3621 if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) { 3622 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3623 "the same time"); 3624 ret = -EINVAL; 3625 goto out; 3626 } 3627 if (qcow2_opts->data_file_raw && 3628 qcow2_opts->preallocation == PREALLOC_MODE_OFF) 3629 { 3630 /* 3631 * data-file-raw means that "the external data file can be 3632 * read as a consistent standalone raw image without looking 3633 * at the qcow2 metadata." It does not say that the metadata 3634 * must be ignored, though (and the qcow2 driver in fact does 3635 * not ignore it), so the L1/L2 tables must be present and 3636 * give a 1:1 mapping, so you get the same result regardless 3637 * of whether you look at the metadata or whether you ignore 3638 * it. 3639 */ 3640 qcow2_opts->preallocation = PREALLOC_MODE_METADATA; 3641 3642 /* 3643 * Cannot use preallocation with backing files, but giving a 3644 * backing file when specifying data_file_raw is an error 3645 * anyway. 3646 */ 3647 assert(!qcow2_opts->backing_file); 3648 } 3649 3650 if (qcow2_opts->data_file) { 3651 if (version < 3) { 3652 error_setg(errp, "External data files are only supported with " 3653 "compatibility level 1.1 and above (use version=v3 or " 3654 "greater)"); 3655 ret = -EINVAL; 3656 goto out; 3657 } 3658 data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp); 3659 if (data_bs == NULL) { 3660 ret = -EIO; 3661 goto out; 3662 } 3663 } 3664 3665 if (qcow2_opts->has_compression_type && 3666 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3667 3668 ret = -EINVAL; 3669 3670 if (version < 3) { 3671 error_setg(errp, "Non-zlib compression type is only supported with " 3672 "compatibility level 1.1 and above (use version=v3 or " 3673 "greater)"); 3674 goto out; 3675 } 3676 3677 switch (qcow2_opts->compression_type) { 3678 #ifdef CONFIG_ZSTD 3679 case QCOW2_COMPRESSION_TYPE_ZSTD: 3680 break; 3681 #endif 3682 default: 3683 error_setg(errp, "Unknown compression type"); 3684 goto out; 3685 } 3686 3687 compression_type = qcow2_opts->compression_type; 3688 } 3689 3690 /* Create BlockBackend to write to the image */ 3691 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 3692 errp); 3693 if (!blk) { 3694 ret = -EPERM; 3695 goto out; 3696 } 3697 blk_set_allow_write_beyond_eof(blk, true); 3698 3699 /* Write the header */ 3700 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3701 header = g_malloc0(cluster_size); 3702 *header = (QCowHeader) { 3703 .magic = cpu_to_be32(QCOW_MAGIC), 3704 .version = cpu_to_be32(version), 3705 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3706 .size = cpu_to_be64(0), 3707 .l1_table_offset = cpu_to_be64(0), 3708 .l1_size = cpu_to_be32(0), 3709 .refcount_table_offset = cpu_to_be64(cluster_size), 3710 .refcount_table_clusters = cpu_to_be32(1), 3711 .refcount_order = cpu_to_be32(refcount_order), 3712 /* don't deal with endianness since compression_type is 1 byte long */ 3713 .compression_type = compression_type, 3714 .header_length = cpu_to_be32(sizeof(*header)), 3715 }; 3716 3717 /* We'll update this to correct value later */ 3718 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3719 3720 if (qcow2_opts->lazy_refcounts) { 3721 header->compatible_features |= 3722 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3723 } 3724 if (data_bs) { 3725 header->incompatible_features |= 3726 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3727 } 3728 if (qcow2_opts->data_file_raw) { 3729 header->autoclear_features |= 3730 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3731 } 3732 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3733 header->incompatible_features |= 3734 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); 3735 } 3736 3737 if (qcow2_opts->extended_l2) { 3738 header->incompatible_features |= 3739 cpu_to_be64(QCOW2_INCOMPAT_EXTL2); 3740 } 3741 3742 ret = blk_co_pwrite(blk, 0, cluster_size, header, 0); 3743 g_free(header); 3744 if (ret < 0) { 3745 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3746 goto out; 3747 } 3748 3749 /* Write a refcount table with one refcount block */ 3750 refcount_table = g_malloc0(2 * cluster_size); 3751 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3752 ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0); 3753 g_free(refcount_table); 3754 3755 if (ret < 0) { 3756 error_setg_errno(errp, -ret, "Could not write refcount table"); 3757 goto out; 3758 } 3759 3760 blk_co_unref(blk); 3761 blk = NULL; 3762 3763 /* 3764 * And now open the image and make it consistent first (i.e. increase the 3765 * refcount of the cluster that is occupied by the header and the refcount 3766 * table) 3767 */ 3768 options = qdict_new(); 3769 qdict_put_str(options, "driver", "qcow2"); 3770 qdict_put_str(options, "file", bs->node_name); 3771 if (data_bs) { 3772 qdict_put_str(options, "data-file", data_bs->node_name); 3773 } 3774 blk = blk_co_new_open(NULL, NULL, options, 3775 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3776 errp); 3777 if (blk == NULL) { 3778 ret = -EIO; 3779 goto out; 3780 } 3781 3782 bdrv_graph_co_rdlock(); 3783 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3784 if (ret < 0) { 3785 bdrv_graph_co_rdunlock(); 3786 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3787 "header and refcount table"); 3788 goto out; 3789 3790 } else if (ret != 0) { 3791 error_report("Huh, first cluster in empty image is already in use?"); 3792 abort(); 3793 } 3794 3795 /* Set the external data file if necessary */ 3796 if (data_bs) { 3797 BDRVQcow2State *s = blk_bs(blk)->opaque; 3798 s->image_data_file = g_strdup(data_bs->filename); 3799 } 3800 3801 /* Create a full header (including things like feature table) */ 3802 ret = qcow2_update_header(blk_bs(blk)); 3803 bdrv_graph_co_rdunlock(); 3804 3805 if (ret < 0) { 3806 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3807 goto out; 3808 } 3809 3810 /* Okay, now that we have a valid image, let's give it the right size */ 3811 ret = blk_co_truncate(blk, qcow2_opts->size, false, 3812 qcow2_opts->preallocation, 0, errp); 3813 if (ret < 0) { 3814 error_prepend(errp, "Could not resize image: "); 3815 goto out; 3816 } 3817 3818 /* Want a backing file? There you go. */ 3819 if (qcow2_opts->backing_file) { 3820 const char *backing_format = NULL; 3821 3822 if (qcow2_opts->has_backing_fmt) { 3823 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3824 } 3825 3826 bdrv_graph_co_rdlock(); 3827 ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3828 backing_format, false); 3829 bdrv_graph_co_rdunlock(); 3830 3831 if (ret < 0) { 3832 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3833 "with format '%s'", qcow2_opts->backing_file, 3834 backing_format); 3835 goto out; 3836 } 3837 } 3838 3839 /* Want encryption? There you go. */ 3840 if (qcow2_opts->encrypt) { 3841 bdrv_graph_co_rdlock(); 3842 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3843 bdrv_graph_co_rdunlock(); 3844 3845 if (ret < 0) { 3846 goto out; 3847 } 3848 } 3849 3850 blk_co_unref(blk); 3851 blk = NULL; 3852 3853 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3854 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3855 * have to setup decryption context. We're not doing any I/O on the top 3856 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3857 * not have effect. 3858 */ 3859 options = qdict_new(); 3860 qdict_put_str(options, "driver", "qcow2"); 3861 qdict_put_str(options, "file", bs->node_name); 3862 if (data_bs) { 3863 qdict_put_str(options, "data-file", data_bs->node_name); 3864 } 3865 blk = blk_co_new_open(NULL, NULL, options, 3866 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3867 errp); 3868 if (blk == NULL) { 3869 ret = -EIO; 3870 goto out; 3871 } 3872 3873 ret = 0; 3874 out: 3875 blk_co_unref(blk); 3876 bdrv_co_unref(bs); 3877 bdrv_co_unref(data_bs); 3878 return ret; 3879 } 3880 3881 static int coroutine_fn GRAPH_UNLOCKED 3882 qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, 3883 Error **errp) 3884 { 3885 BlockdevCreateOptions *create_options = NULL; 3886 QDict *qdict; 3887 Visitor *v; 3888 BlockDriverState *bs = NULL; 3889 BlockDriverState *data_bs = NULL; 3890 const char *val; 3891 int ret; 3892 3893 /* Only the keyval visitor supports the dotted syntax needed for 3894 * encryption, so go through a QDict before getting a QAPI type. Ignore 3895 * options meant for the protocol layer so that the visitor doesn't 3896 * complain. */ 3897 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3898 true); 3899 3900 /* Handle encryption options */ 3901 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3902 if (val && !strcmp(val, "on")) { 3903 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3904 } else if (val && !strcmp(val, "off")) { 3905 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3906 } 3907 3908 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3909 if (val && !strcmp(val, "aes")) { 3910 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3911 } 3912 3913 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3914 * version=v2/v3 below. */ 3915 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3916 if (val && !strcmp(val, "0.10")) { 3917 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3918 } else if (val && !strcmp(val, "1.1")) { 3919 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3920 } 3921 3922 /* Change legacy command line options into QMP ones */ 3923 static const QDictRenames opt_renames[] = { 3924 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3925 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3926 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3927 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3928 { BLOCK_OPT_EXTL2, "extended-l2" }, 3929 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3930 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3931 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3932 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3933 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, 3934 { NULL, NULL }, 3935 }; 3936 3937 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3938 ret = -EINVAL; 3939 goto finish; 3940 } 3941 3942 /* Create and open the file (protocol layer) */ 3943 ret = bdrv_co_create_file(filename, opts, errp); 3944 if (ret < 0) { 3945 goto finish; 3946 } 3947 3948 bs = bdrv_co_open(filename, NULL, NULL, 3949 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3950 if (bs == NULL) { 3951 ret = -EIO; 3952 goto finish; 3953 } 3954 3955 /* Create and open an external data file (protocol layer) */ 3956 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3957 if (val) { 3958 ret = bdrv_co_create_file(val, opts, errp); 3959 if (ret < 0) { 3960 goto finish; 3961 } 3962 3963 data_bs = bdrv_co_open(val, NULL, NULL, 3964 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3965 errp); 3966 if (data_bs == NULL) { 3967 ret = -EIO; 3968 goto finish; 3969 } 3970 3971 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3972 qdict_put_str(qdict, "data-file", data_bs->node_name); 3973 } 3974 3975 /* Set 'driver' and 'node' options */ 3976 qdict_put_str(qdict, "driver", "qcow2"); 3977 qdict_put_str(qdict, "file", bs->node_name); 3978 3979 /* Now get the QAPI type BlockdevCreateOptions */ 3980 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3981 if (!v) { 3982 ret = -EINVAL; 3983 goto finish; 3984 } 3985 3986 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 3987 visit_free(v); 3988 if (!create_options) { 3989 ret = -EINVAL; 3990 goto finish; 3991 } 3992 3993 /* Silently round up size */ 3994 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 3995 BDRV_SECTOR_SIZE); 3996 3997 /* Create the qcow2 image (format layer) */ 3998 ret = qcow2_co_create(create_options, errp); 3999 finish: 4000 if (ret < 0) { 4001 bdrv_graph_co_rdlock(); 4002 bdrv_co_delete_file_noerr(bs); 4003 bdrv_co_delete_file_noerr(data_bs); 4004 bdrv_graph_co_rdunlock(); 4005 } else { 4006 ret = 0; 4007 } 4008 4009 qobject_unref(qdict); 4010 bdrv_co_unref(bs); 4011 bdrv_co_unref(data_bs); 4012 qapi_free_BlockdevCreateOptions(create_options); 4013 return ret; 4014 } 4015 4016 4017 static bool coroutine_fn GRAPH_RDLOCK 4018 is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 4019 { 4020 int64_t nr; 4021 int res; 4022 4023 /* Clamp to image length, before checking status of underlying sectors */ 4024 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 4025 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 4026 } 4027 4028 if (!bytes) { 4029 return true; 4030 } 4031 4032 /* 4033 * bdrv_block_status_above doesn't merge different types of zeros, for 4034 * example, zeros which come from the region which is unallocated in 4035 * the whole backing chain, and zeros which come because of a short 4036 * backing file. So, we need a loop. 4037 */ 4038 do { 4039 res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 4040 offset += nr; 4041 bytes -= nr; 4042 } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes); 4043 4044 return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0; 4045 } 4046 4047 static int coroutine_fn GRAPH_RDLOCK 4048 qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 4049 BdrvRequestFlags flags) 4050 { 4051 int ret; 4052 BDRVQcow2State *s = bs->opaque; 4053 4054 uint32_t head = offset_into_subcluster(s, offset); 4055 uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) - 4056 (offset + bytes); 4057 4058 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 4059 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 4060 tail = 0; 4061 } 4062 4063 if (head || tail) { 4064 uint64_t off; 4065 unsigned int nr; 4066 QCow2SubclusterType type; 4067 4068 assert(head + bytes + tail <= s->subcluster_size); 4069 4070 /* check whether remainder of cluster already reads as zero */ 4071 if (!(is_zero(bs, offset - head, head) && 4072 is_zero(bs, offset + bytes, tail))) { 4073 return -ENOTSUP; 4074 } 4075 4076 qemu_co_mutex_lock(&s->lock); 4077 /* We can have new write after previous check */ 4078 offset -= head; 4079 bytes = s->subcluster_size; 4080 nr = s->subcluster_size; 4081 ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type); 4082 if (ret < 0 || 4083 (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 4084 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && 4085 type != QCOW2_SUBCLUSTER_ZERO_PLAIN && 4086 type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) { 4087 qemu_co_mutex_unlock(&s->lock); 4088 return ret < 0 ? ret : -ENOTSUP; 4089 } 4090 } else { 4091 qemu_co_mutex_lock(&s->lock); 4092 } 4093 4094 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 4095 4096 /* Whatever is left can use real zero subclusters */ 4097 ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags); 4098 qemu_co_mutex_unlock(&s->lock); 4099 4100 return ret; 4101 } 4102 4103 static int coroutine_fn GRAPH_RDLOCK 4104 qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 4105 { 4106 int ret; 4107 BDRVQcow2State *s = bs->opaque; 4108 4109 /* If the image does not support QCOW_OFLAG_ZERO then discarding 4110 * clusters could expose stale data from the backing file. */ 4111 if (s->qcow_version < 3 && bs->backing) { 4112 return -ENOTSUP; 4113 } 4114 4115 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 4116 assert(bytes < s->cluster_size); 4117 /* Ignore partial clusters, except for the special case of the 4118 * complete partial cluster at the end of an unaligned file */ 4119 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 4120 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 4121 return -ENOTSUP; 4122 } 4123 } 4124 4125 qemu_co_mutex_lock(&s->lock); 4126 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 4127 false); 4128 qemu_co_mutex_unlock(&s->lock); 4129 return ret; 4130 } 4131 4132 static int coroutine_fn GRAPH_RDLOCK 4133 qcow2_co_copy_range_from(BlockDriverState *bs, 4134 BdrvChild *src, int64_t src_offset, 4135 BdrvChild *dst, int64_t dst_offset, 4136 int64_t bytes, BdrvRequestFlags read_flags, 4137 BdrvRequestFlags write_flags) 4138 { 4139 BDRVQcow2State *s = bs->opaque; 4140 int ret; 4141 unsigned int cur_bytes; /* number of bytes in current iteration */ 4142 BdrvChild *child = NULL; 4143 BdrvRequestFlags cur_write_flags; 4144 4145 assert(!bs->encrypted); 4146 qemu_co_mutex_lock(&s->lock); 4147 4148 while (bytes != 0) { 4149 uint64_t copy_offset = 0; 4150 QCow2SubclusterType type; 4151 /* prepare next request */ 4152 cur_bytes = MIN(bytes, INT_MAX); 4153 cur_write_flags = write_flags; 4154 4155 ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes, 4156 ©_offset, &type); 4157 if (ret < 0) { 4158 goto out; 4159 } 4160 4161 switch (type) { 4162 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 4163 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 4164 if (bs->backing && bs->backing->bs) { 4165 int64_t backing_length = bdrv_co_getlength(bs->backing->bs); 4166 if (src_offset >= backing_length) { 4167 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4168 } else { 4169 child = bs->backing; 4170 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 4171 copy_offset = src_offset; 4172 } 4173 } else { 4174 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4175 } 4176 break; 4177 4178 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 4179 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 4180 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4181 break; 4182 4183 case QCOW2_SUBCLUSTER_COMPRESSED: 4184 ret = -ENOTSUP; 4185 goto out; 4186 4187 case QCOW2_SUBCLUSTER_NORMAL: 4188 child = s->data_file; 4189 break; 4190 4191 default: 4192 abort(); 4193 } 4194 qemu_co_mutex_unlock(&s->lock); 4195 ret = bdrv_co_copy_range_from(child, 4196 copy_offset, 4197 dst, dst_offset, 4198 cur_bytes, read_flags, cur_write_flags); 4199 qemu_co_mutex_lock(&s->lock); 4200 if (ret < 0) { 4201 goto out; 4202 } 4203 4204 bytes -= cur_bytes; 4205 src_offset += cur_bytes; 4206 dst_offset += cur_bytes; 4207 } 4208 ret = 0; 4209 4210 out: 4211 qemu_co_mutex_unlock(&s->lock); 4212 return ret; 4213 } 4214 4215 static int coroutine_fn GRAPH_RDLOCK 4216 qcow2_co_copy_range_to(BlockDriverState *bs, 4217 BdrvChild *src, int64_t src_offset, 4218 BdrvChild *dst, int64_t dst_offset, 4219 int64_t bytes, BdrvRequestFlags read_flags, 4220 BdrvRequestFlags write_flags) 4221 { 4222 BDRVQcow2State *s = bs->opaque; 4223 int ret; 4224 unsigned int cur_bytes; /* number of sectors in current iteration */ 4225 uint64_t host_offset; 4226 QCowL2Meta *l2meta = NULL; 4227 4228 assert(!bs->encrypted); 4229 4230 qemu_co_mutex_lock(&s->lock); 4231 4232 while (bytes != 0) { 4233 4234 l2meta = NULL; 4235 4236 cur_bytes = MIN(bytes, INT_MAX); 4237 4238 /* TODO: 4239 * If src->bs == dst->bs, we could simply copy by incrementing 4240 * the refcnt, without copying user data. 4241 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 4242 ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes, 4243 &host_offset, &l2meta); 4244 if (ret < 0) { 4245 goto fail; 4246 } 4247 4248 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes, 4249 true); 4250 if (ret < 0) { 4251 goto fail; 4252 } 4253 4254 qemu_co_mutex_unlock(&s->lock); 4255 ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset, 4256 cur_bytes, read_flags, write_flags); 4257 qemu_co_mutex_lock(&s->lock); 4258 if (ret < 0) { 4259 goto fail; 4260 } 4261 4262 ret = qcow2_handle_l2meta(bs, &l2meta, true); 4263 if (ret) { 4264 goto fail; 4265 } 4266 4267 bytes -= cur_bytes; 4268 src_offset += cur_bytes; 4269 dst_offset += cur_bytes; 4270 } 4271 ret = 0; 4272 4273 fail: 4274 qcow2_handle_l2meta(bs, &l2meta, false); 4275 4276 qemu_co_mutex_unlock(&s->lock); 4277 4278 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 4279 4280 return ret; 4281 } 4282 4283 static int coroutine_fn GRAPH_RDLOCK 4284 qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, 4285 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) 4286 { 4287 ERRP_GUARD(); 4288 BDRVQcow2State *s = bs->opaque; 4289 uint64_t old_length; 4290 int64_t new_l1_size; 4291 int ret; 4292 QDict *options; 4293 4294 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 4295 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 4296 { 4297 error_setg(errp, "Unsupported preallocation mode '%s'", 4298 PreallocMode_str(prealloc)); 4299 return -ENOTSUP; 4300 } 4301 4302 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) { 4303 error_setg(errp, "The new size must be a multiple of %u", 4304 (unsigned) BDRV_SECTOR_SIZE); 4305 return -EINVAL; 4306 } 4307 4308 qemu_co_mutex_lock(&s->lock); 4309 4310 /* 4311 * Even though we store snapshot size for all images, it was not 4312 * required until v3, so it is not safe to proceed for v2. 4313 */ 4314 if (s->nb_snapshots && s->qcow_version < 3) { 4315 error_setg(errp, "Can't resize a v2 image which has snapshots"); 4316 ret = -ENOTSUP; 4317 goto fail; 4318 } 4319 4320 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */ 4321 if (qcow2_truncate_bitmaps_check(bs, errp)) { 4322 ret = -ENOTSUP; 4323 goto fail; 4324 } 4325 4326 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 4327 new_l1_size = size_to_l1(s, offset); 4328 4329 if (offset < old_length) { 4330 int64_t last_cluster, old_file_size; 4331 if (prealloc != PREALLOC_MODE_OFF) { 4332 error_setg(errp, 4333 "Preallocation can't be used for shrinking an image"); 4334 ret = -EINVAL; 4335 goto fail; 4336 } 4337 4338 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 4339 old_length - ROUND_UP(offset, 4340 s->cluster_size), 4341 QCOW2_DISCARD_ALWAYS, true); 4342 if (ret < 0) { 4343 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 4344 goto fail; 4345 } 4346 4347 ret = qcow2_shrink_l1_table(bs, new_l1_size); 4348 if (ret < 0) { 4349 error_setg_errno(errp, -ret, 4350 "Failed to reduce the number of L2 tables"); 4351 goto fail; 4352 } 4353 4354 ret = qcow2_shrink_reftable(bs); 4355 if (ret < 0) { 4356 error_setg_errno(errp, -ret, 4357 "Failed to discard unused refblocks"); 4358 goto fail; 4359 } 4360 4361 old_file_size = bdrv_co_getlength(bs->file->bs); 4362 if (old_file_size < 0) { 4363 error_setg_errno(errp, -old_file_size, 4364 "Failed to inquire current file length"); 4365 ret = old_file_size; 4366 goto fail; 4367 } 4368 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4369 if (last_cluster < 0) { 4370 error_setg_errno(errp, -last_cluster, 4371 "Failed to find the last cluster"); 4372 ret = last_cluster; 4373 goto fail; 4374 } 4375 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 4376 Error *local_err = NULL; 4377 4378 /* 4379 * Do not pass @exact here: It will not help the user if 4380 * we get an error here just because they wanted to shrink 4381 * their qcow2 image (on a block device) with qemu-img. 4382 * (And on the qcow2 layer, the @exact requirement is 4383 * always fulfilled, so there is no need to pass it on.) 4384 */ 4385 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 4386 false, PREALLOC_MODE_OFF, 0, &local_err); 4387 if (local_err) { 4388 warn_reportf_err(local_err, 4389 "Failed to truncate the tail of the image: "); 4390 } 4391 } 4392 } else { 4393 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 4394 if (ret < 0) { 4395 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 4396 goto fail; 4397 } 4398 4399 if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) { 4400 /* 4401 * When creating a qcow2 image with data-file-raw, we enforce 4402 * at least prealloc=metadata, so that the L1/L2 tables are 4403 * fully allocated and reading from the data file will return 4404 * the same data as reading from the qcow2 image. When the 4405 * image is grown, we must consequently preallocate the 4406 * metadata structures to cover the added area. 4407 */ 4408 prealloc = PREALLOC_MODE_METADATA; 4409 } 4410 } 4411 4412 switch (prealloc) { 4413 case PREALLOC_MODE_OFF: 4414 if (has_data_file(bs)) { 4415 /* 4416 * If the caller wants an exact resize, the external data 4417 * file should be resized to the exact target size, too, 4418 * so we pass @exact here. 4419 */ 4420 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0, 4421 errp); 4422 if (ret < 0) { 4423 goto fail; 4424 } 4425 } 4426 break; 4427 4428 case PREALLOC_MODE_METADATA: 4429 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4430 if (ret < 0) { 4431 goto fail; 4432 } 4433 break; 4434 4435 case PREALLOC_MODE_FALLOC: 4436 case PREALLOC_MODE_FULL: 4437 { 4438 int64_t allocation_start, host_offset, guest_offset; 4439 int64_t clusters_allocated; 4440 int64_t old_file_size, last_cluster, new_file_size; 4441 uint64_t nb_new_data_clusters, nb_new_l2_tables; 4442 bool subclusters_need_allocation = false; 4443 4444 /* With a data file, preallocation means just allocating the metadata 4445 * and forwarding the truncate request to the data file */ 4446 if (has_data_file(bs)) { 4447 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4448 if (ret < 0) { 4449 goto fail; 4450 } 4451 break; 4452 } 4453 4454 old_file_size = bdrv_co_getlength(bs->file->bs); 4455 if (old_file_size < 0) { 4456 error_setg_errno(errp, -old_file_size, 4457 "Failed to inquire current file length"); 4458 ret = old_file_size; 4459 goto fail; 4460 } 4461 4462 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4463 if (last_cluster >= 0) { 4464 old_file_size = (last_cluster + 1) * s->cluster_size; 4465 } else { 4466 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 4467 } 4468 4469 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) - 4470 start_of_cluster(s, old_length)) >> s->cluster_bits; 4471 4472 /* This is an overestimation; we will not actually allocate space for 4473 * these in the file but just make sure the new refcount structures are 4474 * able to cover them so we will not have to allocate new refblocks 4475 * while entering the data blocks in the potentially new L2 tables. 4476 * (We do not actually care where the L2 tables are placed. Maybe they 4477 * are already allocated or they can be placed somewhere before 4478 * @old_file_size. It does not matter because they will be fully 4479 * allocated automatically, so they do not need to be covered by the 4480 * preallocation. All that matters is that we will not have to allocate 4481 * new refcount structures for them.) */ 4482 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 4483 s->cluster_size / l2_entry_size(s)); 4484 /* The cluster range may not be aligned to L2 boundaries, so add one L2 4485 * table for a potential head/tail */ 4486 nb_new_l2_tables++; 4487 4488 allocation_start = qcow2_refcount_area(bs, old_file_size, 4489 nb_new_data_clusters + 4490 nb_new_l2_tables, 4491 true, 0, 0); 4492 if (allocation_start < 0) { 4493 error_setg_errno(errp, -allocation_start, 4494 "Failed to resize refcount structures"); 4495 ret = allocation_start; 4496 goto fail; 4497 } 4498 4499 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 4500 nb_new_data_clusters); 4501 if (clusters_allocated < 0) { 4502 error_setg_errno(errp, -clusters_allocated, 4503 "Failed to allocate data clusters"); 4504 ret = clusters_allocated; 4505 goto fail; 4506 } 4507 4508 assert(clusters_allocated == nb_new_data_clusters); 4509 4510 /* Allocate the data area */ 4511 new_file_size = allocation_start + 4512 nb_new_data_clusters * s->cluster_size; 4513 /* 4514 * Image file grows, so @exact does not matter. 4515 * 4516 * If we need to zero out the new area, try first whether the protocol 4517 * driver can already take care of this. 4518 */ 4519 if (flags & BDRV_REQ_ZERO_WRITE) { 4520 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 4521 BDRV_REQ_ZERO_WRITE, NULL); 4522 if (ret >= 0) { 4523 flags &= ~BDRV_REQ_ZERO_WRITE; 4524 /* Ensure that we read zeroes and not backing file data */ 4525 subclusters_need_allocation = true; 4526 } 4527 } else { 4528 ret = -1; 4529 } 4530 if (ret < 0) { 4531 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0, 4532 errp); 4533 } 4534 if (ret < 0) { 4535 error_prepend(errp, "Failed to resize underlying file: "); 4536 qcow2_free_clusters(bs, allocation_start, 4537 nb_new_data_clusters * s->cluster_size, 4538 QCOW2_DISCARD_OTHER); 4539 goto fail; 4540 } 4541 4542 /* Create the necessary L2 entries */ 4543 host_offset = allocation_start; 4544 guest_offset = old_length; 4545 while (nb_new_data_clusters) { 4546 int64_t nb_clusters = MIN( 4547 nb_new_data_clusters, 4548 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 4549 unsigned cow_start_length = offset_into_cluster(s, guest_offset); 4550 QCowL2Meta allocation; 4551 guest_offset = start_of_cluster(s, guest_offset); 4552 allocation = (QCowL2Meta) { 4553 .offset = guest_offset, 4554 .alloc_offset = host_offset, 4555 .nb_clusters = nb_clusters, 4556 .cow_start = { 4557 .offset = 0, 4558 .nb_bytes = cow_start_length, 4559 }, 4560 .cow_end = { 4561 .offset = nb_clusters << s->cluster_bits, 4562 .nb_bytes = 0, 4563 }, 4564 .prealloc = !subclusters_need_allocation, 4565 }; 4566 qemu_co_queue_init(&allocation.dependent_requests); 4567 4568 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 4569 if (ret < 0) { 4570 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 4571 qcow2_free_clusters(bs, host_offset, 4572 nb_new_data_clusters * s->cluster_size, 4573 QCOW2_DISCARD_OTHER); 4574 goto fail; 4575 } 4576 4577 guest_offset += nb_clusters * s->cluster_size; 4578 host_offset += nb_clusters * s->cluster_size; 4579 nb_new_data_clusters -= nb_clusters; 4580 } 4581 break; 4582 } 4583 4584 default: 4585 g_assert_not_reached(); 4586 } 4587 4588 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { 4589 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size); 4590 4591 /* 4592 * Use zero clusters as much as we can. qcow2_subcluster_zeroize() 4593 * requires a subcluster-aligned start. The end may be unaligned if 4594 * it is at the end of the image (which it is here). 4595 */ 4596 if (offset > zero_start) { 4597 ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start, 4598 0); 4599 if (ret < 0) { 4600 error_setg_errno(errp, -ret, "Failed to zero out new clusters"); 4601 goto fail; 4602 } 4603 } 4604 4605 /* Write explicit zeros for the unaligned head */ 4606 if (zero_start > old_length) { 4607 uint64_t len = MIN(zero_start, offset) - old_length; 4608 uint8_t *buf = qemu_blockalign0(bs, len); 4609 QEMUIOVector qiov; 4610 qemu_iovec_init_buf(&qiov, buf, len); 4611 4612 qemu_co_mutex_unlock(&s->lock); 4613 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0); 4614 qemu_co_mutex_lock(&s->lock); 4615 4616 qemu_vfree(buf); 4617 if (ret < 0) { 4618 error_setg_errno(errp, -ret, "Failed to zero out the new area"); 4619 goto fail; 4620 } 4621 } 4622 } 4623 4624 if (prealloc != PREALLOC_MODE_OFF) { 4625 /* Flush metadata before actually changing the image size */ 4626 ret = qcow2_write_caches(bs); 4627 if (ret < 0) { 4628 error_setg_errno(errp, -ret, 4629 "Failed to flush the preallocated area to disk"); 4630 goto fail; 4631 } 4632 } 4633 4634 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 4635 4636 /* write updated header.size */ 4637 offset = cpu_to_be64(offset); 4638 ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size), 4639 sizeof(offset), &offset, 0); 4640 if (ret < 0) { 4641 error_setg_errno(errp, -ret, "Failed to update the image size"); 4642 goto fail; 4643 } 4644 4645 s->l1_vm_state_index = new_l1_size; 4646 4647 /* Update cache sizes */ 4648 options = qdict_clone_shallow(bs->options); 4649 ret = qcow2_update_options(bs, options, s->flags, errp); 4650 qobject_unref(options); 4651 if (ret < 0) { 4652 goto fail; 4653 } 4654 ret = 0; 4655 fail: 4656 qemu_co_mutex_unlock(&s->lock); 4657 return ret; 4658 } 4659 4660 static int coroutine_fn GRAPH_RDLOCK 4661 qcow2_co_pwritev_compressed_task(BlockDriverState *bs, 4662 uint64_t offset, uint64_t bytes, 4663 QEMUIOVector *qiov, size_t qiov_offset) 4664 { 4665 BDRVQcow2State *s = bs->opaque; 4666 int ret; 4667 ssize_t out_len; 4668 uint8_t *buf, *out_buf; 4669 uint64_t cluster_offset; 4670 4671 assert(bytes == s->cluster_size || (bytes < s->cluster_size && 4672 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))); 4673 4674 buf = qemu_blockalign(bs, s->cluster_size); 4675 if (bytes < s->cluster_size) { 4676 /* Zero-pad last write if image size is not cluster aligned */ 4677 memset(buf + bytes, 0, s->cluster_size - bytes); 4678 } 4679 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); 4680 4681 out_buf = g_malloc(s->cluster_size); 4682 4683 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4684 buf, s->cluster_size); 4685 if (out_len == -ENOMEM) { 4686 /* could not compress: write normal cluster */ 4687 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); 4688 if (ret < 0) { 4689 goto fail; 4690 } 4691 goto success; 4692 } else if (out_len < 0) { 4693 ret = -EINVAL; 4694 goto fail; 4695 } 4696 4697 qemu_co_mutex_lock(&s->lock); 4698 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4699 &cluster_offset); 4700 if (ret < 0) { 4701 qemu_co_mutex_unlock(&s->lock); 4702 goto fail; 4703 } 4704 4705 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4706 qemu_co_mutex_unlock(&s->lock); 4707 if (ret < 0) { 4708 goto fail; 4709 } 4710 4711 BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4712 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); 4713 if (ret < 0) { 4714 goto fail; 4715 } 4716 success: 4717 ret = 0; 4718 fail: 4719 qemu_vfree(buf); 4720 g_free(out_buf); 4721 return ret; 4722 } 4723 4724 /* 4725 * This function can count as GRAPH_RDLOCK because 4726 * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until 4727 * this coroutine has terminated. 4728 */ 4729 static int coroutine_fn GRAPH_RDLOCK 4730 qcow2_co_pwritev_compressed_task_entry(AioTask *task) 4731 { 4732 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 4733 4734 assert(!t->subcluster_type && !t->l2meta); 4735 4736 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov, 4737 t->qiov_offset); 4738 } 4739 4740 /* 4741 * XXX: put compressed sectors first, then all the cluster aligned 4742 * tables to avoid losing bytes in alignment 4743 */ 4744 static int coroutine_fn GRAPH_RDLOCK 4745 qcow2_co_pwritev_compressed_part(BlockDriverState *bs, 4746 int64_t offset, int64_t bytes, 4747 QEMUIOVector *qiov, size_t qiov_offset) 4748 { 4749 BDRVQcow2State *s = bs->opaque; 4750 AioTaskPool *aio = NULL; 4751 int ret = 0; 4752 4753 if (has_data_file(bs)) { 4754 return -ENOTSUP; 4755 } 4756 4757 if (bytes == 0) { 4758 /* 4759 * align end of file to a sector boundary to ease reading with 4760 * sector based I/Os 4761 */ 4762 int64_t len = bdrv_co_getlength(bs->file->bs); 4763 if (len < 0) { 4764 return len; 4765 } 4766 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0, 4767 NULL); 4768 } 4769 4770 if (offset_into_cluster(s, offset)) { 4771 return -EINVAL; 4772 } 4773 4774 if (offset_into_cluster(s, bytes) && 4775 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) { 4776 return -EINVAL; 4777 } 4778 4779 while (bytes && aio_task_pool_status(aio) == 0) { 4780 uint64_t chunk_size = MIN(bytes, s->cluster_size); 4781 4782 if (!aio && chunk_size != bytes) { 4783 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 4784 } 4785 4786 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry, 4787 0, 0, offset, chunk_size, qiov, qiov_offset, NULL); 4788 if (ret < 0) { 4789 break; 4790 } 4791 qiov_offset += chunk_size; 4792 offset += chunk_size; 4793 bytes -= chunk_size; 4794 } 4795 4796 if (aio) { 4797 aio_task_pool_wait_all(aio); 4798 if (ret == 0) { 4799 ret = aio_task_pool_status(aio); 4800 } 4801 g_free(aio); 4802 } 4803 4804 return ret; 4805 } 4806 4807 static int coroutine_fn GRAPH_RDLOCK 4808 qcow2_co_preadv_compressed(BlockDriverState *bs, 4809 uint64_t l2_entry, 4810 uint64_t offset, 4811 uint64_t bytes, 4812 QEMUIOVector *qiov, 4813 size_t qiov_offset) 4814 { 4815 BDRVQcow2State *s = bs->opaque; 4816 int ret = 0, csize; 4817 uint64_t coffset; 4818 uint8_t *buf, *out_buf; 4819 int offset_in_cluster = offset_into_cluster(s, offset); 4820 4821 qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize); 4822 4823 buf = g_try_malloc(csize); 4824 if (!buf) { 4825 return -ENOMEM; 4826 } 4827 4828 out_buf = qemu_blockalign(bs, s->cluster_size); 4829 4830 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4831 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0); 4832 if (ret < 0) { 4833 goto fail; 4834 } 4835 4836 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4837 ret = -EIO; 4838 goto fail; 4839 } 4840 4841 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); 4842 4843 fail: 4844 qemu_vfree(out_buf); 4845 g_free(buf); 4846 4847 return ret; 4848 } 4849 4850 static int GRAPH_RDLOCK make_completely_empty(BlockDriverState *bs) 4851 { 4852 BDRVQcow2State *s = bs->opaque; 4853 Error *local_err = NULL; 4854 int ret, l1_clusters; 4855 int64_t offset; 4856 uint64_t *new_reftable = NULL; 4857 uint64_t rt_entry, l1_size2; 4858 struct { 4859 uint64_t l1_offset; 4860 uint64_t reftable_offset; 4861 uint32_t reftable_clusters; 4862 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4863 4864 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4865 if (ret < 0) { 4866 goto fail; 4867 } 4868 4869 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4870 if (ret < 0) { 4871 goto fail; 4872 } 4873 4874 /* Refcounts will be broken utterly */ 4875 ret = qcow2_mark_dirty(bs); 4876 if (ret < 0) { 4877 goto fail; 4878 } 4879 4880 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4881 4882 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 4883 l1_size2 = (uint64_t)s->l1_size * L1E_SIZE; 4884 4885 /* After this call, neither the in-memory nor the on-disk refcount 4886 * information accurately describe the actual references */ 4887 4888 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4889 l1_clusters * s->cluster_size, 0); 4890 if (ret < 0) { 4891 goto fail_broken_refcounts; 4892 } 4893 memset(s->l1_table, 0, l1_size2); 4894 4895 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4896 4897 /* Overwrite enough clusters at the beginning of the sectors to place 4898 * the refcount table, a refcount block and the L1 table in; this may 4899 * overwrite parts of the existing refcount and L1 table, which is not 4900 * an issue because the dirty flag is set, complete data loss is in fact 4901 * desired and partial data loss is consequently fine as well */ 4902 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4903 (2 + l1_clusters) * s->cluster_size, 0); 4904 /* This call (even if it failed overall) may have overwritten on-disk 4905 * refcount structures; in that case, the in-memory refcount information 4906 * will probably differ from the on-disk information which makes the BDS 4907 * unusable */ 4908 if (ret < 0) { 4909 goto fail_broken_refcounts; 4910 } 4911 4912 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4913 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4914 4915 /* "Create" an empty reftable (one cluster) directly after the image 4916 * header and an empty L1 table three clusters after the image header; 4917 * the cluster between those two will be used as the first refblock */ 4918 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4919 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4920 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4921 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4922 sizeof(l1_ofs_rt_ofs_cls), &l1_ofs_rt_ofs_cls, 0); 4923 if (ret < 0) { 4924 goto fail_broken_refcounts; 4925 } 4926 4927 s->l1_table_offset = 3 * s->cluster_size; 4928 4929 new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE); 4930 if (!new_reftable) { 4931 ret = -ENOMEM; 4932 goto fail_broken_refcounts; 4933 } 4934 4935 s->refcount_table_offset = s->cluster_size; 4936 s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE; 4937 s->max_refcount_table_index = 0; 4938 4939 g_free(s->refcount_table); 4940 s->refcount_table = new_reftable; 4941 new_reftable = NULL; 4942 4943 /* Now the in-memory refcount information again corresponds to the on-disk 4944 * information (reftable is empty and no refblocks (the refblock cache is 4945 * empty)); however, this means some clusters (e.g. the image header) are 4946 * referenced, but not refcounted, but the normal qcow2 code assumes that 4947 * the in-memory information is always correct */ 4948 4949 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4950 4951 /* Enter the first refblock into the reftable */ 4952 rt_entry = cpu_to_be64(2 * s->cluster_size); 4953 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, sizeof(rt_entry), 4954 &rt_entry, 0); 4955 if (ret < 0) { 4956 goto fail_broken_refcounts; 4957 } 4958 s->refcount_table[0] = 2 * s->cluster_size; 4959 4960 s->free_cluster_index = 0; 4961 assert(3 + l1_clusters <= s->refcount_block_size); 4962 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4963 if (offset < 0) { 4964 ret = offset; 4965 goto fail_broken_refcounts; 4966 } else if (offset > 0) { 4967 error_report("First cluster in emptied image is in use"); 4968 abort(); 4969 } 4970 4971 /* Now finally the in-memory information corresponds to the on-disk 4972 * structures and is correct */ 4973 ret = qcow2_mark_clean(bs); 4974 if (ret < 0) { 4975 goto fail; 4976 } 4977 4978 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false, 4979 PREALLOC_MODE_OFF, 0, &local_err); 4980 if (ret < 0) { 4981 error_report_err(local_err); 4982 goto fail; 4983 } 4984 4985 return 0; 4986 4987 fail_broken_refcounts: 4988 /* The BDS is unusable at this point. If we wanted to make it usable, we 4989 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 4990 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 4991 * again. However, because the functions which could have caused this error 4992 * path to be taken are used by those functions as well, it's very likely 4993 * that that sequence will fail as well. Therefore, just eject the BDS. */ 4994 bs->drv = NULL; 4995 4996 fail: 4997 g_free(new_reftable); 4998 return ret; 4999 } 5000 5001 static int GRAPH_RDLOCK qcow2_make_empty(BlockDriverState *bs) 5002 { 5003 BDRVQcow2State *s = bs->opaque; 5004 uint64_t offset, end_offset; 5005 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 5006 int l1_clusters, ret = 0; 5007 5008 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 5009 5010 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 5011 3 + l1_clusters <= s->refcount_block_size && 5012 s->crypt_method_header != QCOW_CRYPT_LUKS && 5013 !has_data_file(bs)) { 5014 /* The following function only works for qcow2 v3 images (it 5015 * requires the dirty flag) and only as long as there are no 5016 * features that reserve extra clusters (such as snapshots, 5017 * LUKS header, or persistent bitmaps), because it completely 5018 * empties the image. Furthermore, the L1 table and three 5019 * additional clusters (image header, refcount table, one 5020 * refcount block) have to fit inside one refcount block. It 5021 * only resets the image file, i.e. does not work with an 5022 * external data file. */ 5023 return make_completely_empty(bs); 5024 } 5025 5026 /* This fallback code simply discards every active cluster; this is slow, 5027 * but works in all cases */ 5028 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 5029 for (offset = 0; offset < end_offset; offset += step) { 5030 /* As this function is generally used after committing an external 5031 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 5032 * default action for this kind of discard is to pass the discard, 5033 * which will ideally result in an actually smaller image file, as 5034 * is probably desired. */ 5035 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 5036 QCOW2_DISCARD_SNAPSHOT, true); 5037 if (ret < 0) { 5038 break; 5039 } 5040 } 5041 5042 return ret; 5043 } 5044 5045 static coroutine_fn GRAPH_RDLOCK int qcow2_co_flush_to_os(BlockDriverState *bs) 5046 { 5047 BDRVQcow2State *s = bs->opaque; 5048 int ret; 5049 5050 qemu_co_mutex_lock(&s->lock); 5051 ret = qcow2_write_caches(bs); 5052 qemu_co_mutex_unlock(&s->lock); 5053 5054 return ret; 5055 } 5056 5057 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 5058 Error **errp) 5059 { 5060 Error *local_err = NULL; 5061 BlockMeasureInfo *info; 5062 uint64_t required = 0; /* bytes that contribute to required size */ 5063 uint64_t virtual_size; /* disk size as seen by guest */ 5064 uint64_t refcount_bits; 5065 uint64_t l2_tables; 5066 uint64_t luks_payload_size = 0; 5067 size_t cluster_size; 5068 int version; 5069 char *optstr; 5070 PreallocMode prealloc; 5071 bool has_backing_file; 5072 bool has_luks; 5073 bool extended_l2; 5074 size_t l2e_size; 5075 5076 /* Parse image creation options */ 5077 extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false); 5078 5079 cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2, 5080 &local_err); 5081 if (local_err) { 5082 goto err; 5083 } 5084 5085 version = qcow2_opt_get_version_del(opts, &local_err); 5086 if (local_err) { 5087 goto err; 5088 } 5089 5090 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 5091 if (local_err) { 5092 goto err; 5093 } 5094 5095 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 5096 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 5097 PREALLOC_MODE_OFF, &local_err); 5098 g_free(optstr); 5099 if (local_err) { 5100 goto err; 5101 } 5102 5103 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 5104 has_backing_file = !!optstr; 5105 g_free(optstr); 5106 5107 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 5108 has_luks = optstr && strcmp(optstr, "luks") == 0; 5109 g_free(optstr); 5110 5111 if (has_luks) { 5112 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL; 5113 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp); 5114 size_t headerlen; 5115 5116 create_opts = block_crypto_create_opts_init(cryptoopts, errp); 5117 qobject_unref(cryptoopts); 5118 if (!create_opts) { 5119 goto err; 5120 } 5121 5122 if (!qcrypto_block_calculate_payload_offset(create_opts, 5123 "encrypt.", 5124 &headerlen, 5125 &local_err)) { 5126 goto err; 5127 } 5128 5129 luks_payload_size = ROUND_UP(headerlen, cluster_size); 5130 } 5131 5132 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 5133 virtual_size = ROUND_UP(virtual_size, cluster_size); 5134 5135 /* Check that virtual disk size is valid */ 5136 l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 5137 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 5138 cluster_size / l2e_size); 5139 if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) { 5140 error_setg(&local_err, "The image size is too large " 5141 "(try using a larger cluster size)"); 5142 goto err; 5143 } 5144 5145 /* Account for input image */ 5146 if (in_bs) { 5147 int64_t ssize = bdrv_getlength(in_bs); 5148 if (ssize < 0) { 5149 error_setg_errno(&local_err, -ssize, 5150 "Unable to get image virtual_size"); 5151 goto err; 5152 } 5153 5154 virtual_size = ROUND_UP(ssize, cluster_size); 5155 5156 if (has_backing_file) { 5157 /* We don't how much of the backing chain is shared by the input 5158 * image and the new image file. In the worst case the new image's 5159 * backing file has nothing in common with the input image. Be 5160 * conservative and assume all clusters need to be written. 5161 */ 5162 required = virtual_size; 5163 } else { 5164 int64_t offset; 5165 int64_t pnum = 0; 5166 5167 for (offset = 0; offset < ssize; offset += pnum) { 5168 int ret; 5169 5170 ret = bdrv_block_status_above(in_bs, NULL, offset, 5171 ssize - offset, &pnum, NULL, 5172 NULL); 5173 if (ret < 0) { 5174 error_setg_errno(&local_err, -ret, 5175 "Unable to get block status"); 5176 goto err; 5177 } 5178 5179 if (ret & BDRV_BLOCK_ZERO) { 5180 /* Skip zero regions (safe with no backing file) */ 5181 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 5182 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 5183 /* Extend pnum to end of cluster for next iteration */ 5184 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 5185 5186 /* Count clusters we've seen */ 5187 required += offset % cluster_size + pnum; 5188 } 5189 } 5190 } 5191 } 5192 5193 /* Take into account preallocation. Nothing special is needed for 5194 * PREALLOC_MODE_METADATA since metadata is always counted. 5195 */ 5196 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 5197 required = virtual_size; 5198 } 5199 5200 info = g_new0(BlockMeasureInfo, 1); 5201 info->fully_allocated = luks_payload_size + 5202 qcow2_calc_prealloc_size(virtual_size, cluster_size, 5203 ctz32(refcount_bits), extended_l2); 5204 5205 /* 5206 * Remove data clusters that are not required. This overestimates the 5207 * required size because metadata needed for the fully allocated file is 5208 * still counted. Show bitmaps only if both source and destination 5209 * would support them. 5210 */ 5211 info->required = info->fully_allocated - virtual_size + required; 5212 info->has_bitmaps = version >= 3 && in_bs && 5213 bdrv_supports_persistent_dirty_bitmap(in_bs); 5214 if (info->has_bitmaps) { 5215 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs, 5216 cluster_size); 5217 } 5218 return info; 5219 5220 err: 5221 error_propagate(errp, local_err); 5222 return NULL; 5223 } 5224 5225 static int coroutine_fn 5226 qcow2_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 5227 { 5228 BDRVQcow2State *s = bs->opaque; 5229 bdi->cluster_size = s->cluster_size; 5230 bdi->subcluster_size = s->subcluster_size; 5231 bdi->vm_state_offset = qcow2_vm_state_offset(s); 5232 bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY; 5233 return 0; 5234 } 5235 5236 static ImageInfoSpecific * GRAPH_RDLOCK 5237 qcow2_get_specific_info(BlockDriverState *bs, Error **errp) 5238 { 5239 BDRVQcow2State *s = bs->opaque; 5240 ImageInfoSpecific *spec_info; 5241 QCryptoBlockInfo *encrypt_info = NULL; 5242 5243 if (s->crypto != NULL) { 5244 encrypt_info = qcrypto_block_get_info(s->crypto, errp); 5245 if (!encrypt_info) { 5246 return NULL; 5247 } 5248 } 5249 5250 spec_info = g_new(ImageInfoSpecific, 1); 5251 *spec_info = (ImageInfoSpecific){ 5252 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 5253 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 5254 }; 5255 if (s->qcow_version == 2) { 5256 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5257 .compat = g_strdup("0.10"), 5258 .refcount_bits = s->refcount_bits, 5259 }; 5260 } else if (s->qcow_version == 3) { 5261 Qcow2BitmapInfoList *bitmaps; 5262 if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) { 5263 qapi_free_ImageInfoSpecific(spec_info); 5264 qapi_free_QCryptoBlockInfo(encrypt_info); 5265 return NULL; 5266 } 5267 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5268 .compat = g_strdup("1.1"), 5269 .lazy_refcounts = s->compatible_features & 5270 QCOW2_COMPAT_LAZY_REFCOUNTS, 5271 .has_lazy_refcounts = true, 5272 .corrupt = s->incompatible_features & 5273 QCOW2_INCOMPAT_CORRUPT, 5274 .has_corrupt = true, 5275 .has_extended_l2 = true, 5276 .extended_l2 = has_subclusters(s), 5277 .refcount_bits = s->refcount_bits, 5278 .has_bitmaps = !!bitmaps, 5279 .bitmaps = bitmaps, 5280 .data_file = g_strdup(s->image_data_file), 5281 .has_data_file_raw = has_data_file(bs), 5282 .data_file_raw = data_file_is_raw(bs), 5283 .compression_type = s->compression_type, 5284 }; 5285 } else { 5286 /* if this assertion fails, this probably means a new version was 5287 * added without having it covered here */ 5288 assert(false); 5289 } 5290 5291 if (encrypt_info) { 5292 ImageInfoSpecificQCow2Encryption *qencrypt = 5293 g_new(ImageInfoSpecificQCow2Encryption, 1); 5294 switch (encrypt_info->format) { 5295 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 5296 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 5297 break; 5298 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 5299 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 5300 qencrypt->u.luks = encrypt_info->u.luks; 5301 break; 5302 default: 5303 abort(); 5304 } 5305 /* Since we did shallow copy above, erase any pointers 5306 * in the original info */ 5307 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 5308 qapi_free_QCryptoBlockInfo(encrypt_info); 5309 5310 spec_info->u.qcow2.data->encrypt = qencrypt; 5311 } 5312 5313 return spec_info; 5314 } 5315 5316 static int coroutine_mixed_fn GRAPH_RDLOCK 5317 qcow2_has_zero_init(BlockDriverState *bs) 5318 { 5319 BDRVQcow2State *s = bs->opaque; 5320 bool preallocated; 5321 5322 if (qemu_in_coroutine()) { 5323 qemu_co_mutex_lock(&s->lock); 5324 } 5325 /* 5326 * Check preallocation status: Preallocated images have all L2 5327 * tables allocated, nonpreallocated images have none. It is 5328 * therefore enough to check the first one. 5329 */ 5330 preallocated = s->l1_size > 0 && s->l1_table[0] != 0; 5331 if (qemu_in_coroutine()) { 5332 qemu_co_mutex_unlock(&s->lock); 5333 } 5334 5335 if (!preallocated) { 5336 return 1; 5337 } else if (bs->encrypted) { 5338 return 0; 5339 } else { 5340 return bdrv_has_zero_init(s->data_file->bs); 5341 } 5342 } 5343 5344 /* 5345 * Check the request to vmstate. On success return 5346 * qcow2_vm_state_offset(bs) + @pos 5347 */ 5348 static int64_t qcow2_check_vmstate_request(BlockDriverState *bs, 5349 QEMUIOVector *qiov, int64_t pos) 5350 { 5351 BDRVQcow2State *s = bs->opaque; 5352 int64_t vmstate_offset = qcow2_vm_state_offset(s); 5353 int ret; 5354 5355 /* Incoming requests must be OK */ 5356 bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort); 5357 5358 if (INT64_MAX - pos < vmstate_offset) { 5359 return -EIO; 5360 } 5361 5362 pos += vmstate_offset; 5363 ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL); 5364 if (ret < 0) { 5365 return ret; 5366 } 5367 5368 return pos; 5369 } 5370 5371 static int coroutine_fn GRAPH_RDLOCK 5372 qcow2_co_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5373 { 5374 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5375 if (offset < 0) { 5376 return offset; 5377 } 5378 5379 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 5380 return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0); 5381 } 5382 5383 static int coroutine_fn GRAPH_RDLOCK 5384 qcow2_co_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5385 { 5386 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5387 if (offset < 0) { 5388 return offset; 5389 } 5390 5391 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 5392 return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0); 5393 } 5394 5395 static int GRAPH_RDLOCK qcow2_has_compressed_clusters(BlockDriverState *bs) 5396 { 5397 int64_t offset = 0; 5398 int64_t bytes = bdrv_getlength(bs); 5399 5400 if (bytes < 0) { 5401 return bytes; 5402 } 5403 5404 while (bytes != 0) { 5405 int ret; 5406 QCow2SubclusterType type; 5407 unsigned int cur_bytes = MIN(INT_MAX, bytes); 5408 uint64_t host_offset; 5409 5410 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset, 5411 &type); 5412 if (ret < 0) { 5413 return ret; 5414 } 5415 5416 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 5417 return 1; 5418 } 5419 5420 offset += cur_bytes; 5421 bytes -= cur_bytes; 5422 } 5423 5424 return 0; 5425 } 5426 5427 /* 5428 * Downgrades an image's version. To achieve this, any incompatible features 5429 * have to be removed. 5430 */ 5431 static int GRAPH_RDLOCK 5432 qcow2_downgrade(BlockDriverState *bs, int target_version, 5433 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5434 Error **errp) 5435 { 5436 BDRVQcow2State *s = bs->opaque; 5437 int current_version = s->qcow_version; 5438 int ret; 5439 int i; 5440 5441 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 5442 assert(target_version < current_version); 5443 5444 /* There are no other versions (now) that you can downgrade to */ 5445 assert(target_version == 2); 5446 5447 if (s->refcount_order != 4) { 5448 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 5449 return -ENOTSUP; 5450 } 5451 5452 if (has_data_file(bs)) { 5453 error_setg(errp, "Cannot downgrade an image with a data file"); 5454 return -ENOTSUP; 5455 } 5456 5457 /* 5458 * If any internal snapshot has a different size than the current 5459 * image size, or VM state size that exceeds 32 bits, downgrading 5460 * is unsafe. Even though we would still use v3-compliant output 5461 * to preserve that data, other v2 programs might not realize 5462 * those optional fields are important. 5463 */ 5464 for (i = 0; i < s->nb_snapshots; i++) { 5465 if (s->snapshots[i].vm_state_size > UINT32_MAX || 5466 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { 5467 error_setg(errp, "Internal snapshots prevent downgrade of image"); 5468 return -ENOTSUP; 5469 } 5470 } 5471 5472 /* clear incompatible features */ 5473 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 5474 ret = qcow2_mark_clean(bs); 5475 if (ret < 0) { 5476 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5477 return ret; 5478 } 5479 } 5480 5481 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 5482 * the first place; if that happens nonetheless, returning -ENOTSUP is the 5483 * best thing to do anyway */ 5484 5485 if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) { 5486 error_setg(errp, "Cannot downgrade an image with incompatible features " 5487 "0x%" PRIx64 " set", 5488 s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION); 5489 return -ENOTSUP; 5490 } 5491 5492 /* since we can ignore compatible features, we can set them to 0 as well */ 5493 s->compatible_features = 0; 5494 /* if lazy refcounts have been used, they have already been fixed through 5495 * clearing the dirty flag */ 5496 5497 /* clearing autoclear features is trivial */ 5498 s->autoclear_features = 0; 5499 5500 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 5501 if (ret < 0) { 5502 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 5503 return ret; 5504 } 5505 5506 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 5507 ret = qcow2_has_compressed_clusters(bs); 5508 if (ret < 0) { 5509 error_setg(errp, "Failed to check block status"); 5510 return -EINVAL; 5511 } 5512 if (ret) { 5513 error_setg(errp, "Cannot downgrade an image with zstd compression " 5514 "type and existing compressed clusters"); 5515 return -ENOTSUP; 5516 } 5517 /* 5518 * No compressed clusters for now, so just chose default zlib 5519 * compression. 5520 */ 5521 s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION; 5522 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 5523 } 5524 5525 assert(s->incompatible_features == 0); 5526 5527 s->qcow_version = target_version; 5528 ret = qcow2_update_header(bs); 5529 if (ret < 0) { 5530 s->qcow_version = current_version; 5531 error_setg_errno(errp, -ret, "Failed to update the image header"); 5532 return ret; 5533 } 5534 return 0; 5535 } 5536 5537 /* 5538 * Upgrades an image's version. While newer versions encompass all 5539 * features of older versions, some things may have to be presented 5540 * differently. 5541 */ 5542 static int GRAPH_RDLOCK 5543 qcow2_upgrade(BlockDriverState *bs, int target_version, 5544 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5545 Error **errp) 5546 { 5547 BDRVQcow2State *s = bs->opaque; 5548 bool need_snapshot_update; 5549 int current_version = s->qcow_version; 5550 int i; 5551 int ret; 5552 5553 /* This is qcow2_upgrade(), not qcow2_downgrade() */ 5554 assert(target_version > current_version); 5555 5556 /* There are no other versions (yet) that you can upgrade to */ 5557 assert(target_version == 3); 5558 5559 status_cb(bs, 0, 2, cb_opaque); 5560 5561 /* 5562 * In v2, snapshots do not need to have extra data. v3 requires 5563 * the 64-bit VM state size and the virtual disk size to be 5564 * present. 5565 * qcow2_write_snapshots() will always write the list in the 5566 * v3-compliant format. 5567 */ 5568 need_snapshot_update = false; 5569 for (i = 0; i < s->nb_snapshots; i++) { 5570 if (s->snapshots[i].extra_data_size < 5571 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) + 5572 sizeof_field(QCowSnapshotExtraData, disk_size)) 5573 { 5574 need_snapshot_update = true; 5575 break; 5576 } 5577 } 5578 if (need_snapshot_update) { 5579 ret = qcow2_write_snapshots(bs); 5580 if (ret < 0) { 5581 error_setg_errno(errp, -ret, "Failed to update the snapshot table"); 5582 return ret; 5583 } 5584 } 5585 status_cb(bs, 1, 2, cb_opaque); 5586 5587 s->qcow_version = target_version; 5588 ret = qcow2_update_header(bs); 5589 if (ret < 0) { 5590 s->qcow_version = current_version; 5591 error_setg_errno(errp, -ret, "Failed to update the image header"); 5592 return ret; 5593 } 5594 status_cb(bs, 2, 2, cb_opaque); 5595 5596 return 0; 5597 } 5598 5599 typedef enum Qcow2AmendOperation { 5600 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 5601 * statically initialized to so that the helper CB can discern the first 5602 * invocation from an operation change */ 5603 QCOW2_NO_OPERATION = 0, 5604 5605 QCOW2_UPGRADING, 5606 QCOW2_UPDATING_ENCRYPTION, 5607 QCOW2_CHANGING_REFCOUNT_ORDER, 5608 QCOW2_DOWNGRADING, 5609 } Qcow2AmendOperation; 5610 5611 typedef struct Qcow2AmendHelperCBInfo { 5612 /* The code coordinating the amend operations should only modify 5613 * these four fields; the rest will be managed by the CB */ 5614 BlockDriverAmendStatusCB *original_status_cb; 5615 void *original_cb_opaque; 5616 5617 Qcow2AmendOperation current_operation; 5618 5619 /* Total number of operations to perform (only set once) */ 5620 int total_operations; 5621 5622 /* The following fields are managed by the CB */ 5623 5624 /* Number of operations completed */ 5625 int operations_completed; 5626 5627 /* Cumulative offset of all completed operations */ 5628 int64_t offset_completed; 5629 5630 Qcow2AmendOperation last_operation; 5631 int64_t last_work_size; 5632 } Qcow2AmendHelperCBInfo; 5633 5634 static void qcow2_amend_helper_cb(BlockDriverState *bs, 5635 int64_t operation_offset, 5636 int64_t operation_work_size, void *opaque) 5637 { 5638 Qcow2AmendHelperCBInfo *info = opaque; 5639 int64_t current_work_size; 5640 int64_t projected_work_size; 5641 5642 if (info->current_operation != info->last_operation) { 5643 if (info->last_operation != QCOW2_NO_OPERATION) { 5644 info->offset_completed += info->last_work_size; 5645 info->operations_completed++; 5646 } 5647 5648 info->last_operation = info->current_operation; 5649 } 5650 5651 assert(info->total_operations > 0); 5652 assert(info->operations_completed < info->total_operations); 5653 5654 info->last_work_size = operation_work_size; 5655 5656 current_work_size = info->offset_completed + operation_work_size; 5657 5658 /* current_work_size is the total work size for (operations_completed + 1) 5659 * operations (which includes this one), so multiply it by the number of 5660 * operations not covered and divide it by the number of operations 5661 * covered to get a projection for the operations not covered */ 5662 projected_work_size = current_work_size * (info->total_operations - 5663 info->operations_completed - 1) 5664 / (info->operations_completed + 1); 5665 5666 info->original_status_cb(bs, info->offset_completed + operation_offset, 5667 current_work_size + projected_work_size, 5668 info->original_cb_opaque); 5669 } 5670 5671 static int GRAPH_RDLOCK 5672 qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 5673 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5674 bool force, Error **errp) 5675 { 5676 BDRVQcow2State *s = bs->opaque; 5677 int old_version = s->qcow_version, new_version = old_version; 5678 uint64_t new_size = 0; 5679 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 5680 bool lazy_refcounts = s->use_lazy_refcounts; 5681 bool data_file_raw = data_file_is_raw(bs); 5682 const char *compat = NULL; 5683 int refcount_bits = s->refcount_bits; 5684 int ret; 5685 QemuOptDesc *desc = opts->list->desc; 5686 Qcow2AmendHelperCBInfo helper_cb_info; 5687 bool encryption_update = false; 5688 5689 while (desc && desc->name) { 5690 if (!qemu_opt_find(opts, desc->name)) { 5691 /* only change explicitly defined options */ 5692 desc++; 5693 continue; 5694 } 5695 5696 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 5697 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 5698 if (!compat) { 5699 /* preserve default */ 5700 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) { 5701 new_version = 2; 5702 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) { 5703 new_version = 3; 5704 } else { 5705 error_setg(errp, "Unknown compatibility level %s", compat); 5706 return -EINVAL; 5707 } 5708 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 5709 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 5710 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 5711 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 5712 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 5713 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 5714 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 5715 if (!s->crypto) { 5716 error_setg(errp, 5717 "Can't amend encryption options - encryption not present"); 5718 return -EINVAL; 5719 } 5720 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5721 error_setg(errp, 5722 "Only LUKS encryption options can be amended"); 5723 return -ENOTSUP; 5724 } 5725 encryption_update = true; 5726 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 5727 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 5728 lazy_refcounts); 5729 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 5730 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 5731 refcount_bits); 5732 5733 if (refcount_bits <= 0 || refcount_bits > 64 || 5734 !is_power_of_2(refcount_bits)) 5735 { 5736 error_setg(errp, "Refcount width must be a power of two and " 5737 "may not exceed 64 bits"); 5738 return -EINVAL; 5739 } 5740 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 5741 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 5742 if (data_file && !has_data_file(bs)) { 5743 error_setg(errp, "data-file can only be set for images that " 5744 "use an external data file"); 5745 return -EINVAL; 5746 } 5747 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 5748 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 5749 data_file_raw); 5750 if (data_file_raw && !data_file_is_raw(bs)) { 5751 error_setg(errp, "data-file-raw cannot be set on existing " 5752 "images"); 5753 return -EINVAL; 5754 } 5755 } else { 5756 /* if this point is reached, this probably means a new option was 5757 * added without having it covered here */ 5758 abort(); 5759 } 5760 5761 desc++; 5762 } 5763 5764 helper_cb_info = (Qcow2AmendHelperCBInfo){ 5765 .original_status_cb = status_cb, 5766 .original_cb_opaque = cb_opaque, 5767 .total_operations = (new_version != old_version) 5768 + (s->refcount_bits != refcount_bits) + 5769 (encryption_update == true) 5770 }; 5771 5772 /* Upgrade first (some features may require compat=1.1) */ 5773 if (new_version > old_version) { 5774 helper_cb_info.current_operation = QCOW2_UPGRADING; 5775 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb, 5776 &helper_cb_info, errp); 5777 if (ret < 0) { 5778 return ret; 5779 } 5780 } 5781 5782 if (encryption_update) { 5783 QDict *amend_opts_dict; 5784 QCryptoBlockAmendOptions *amend_opts; 5785 5786 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION; 5787 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp); 5788 if (!amend_opts_dict) { 5789 return -EINVAL; 5790 } 5791 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp); 5792 qobject_unref(amend_opts_dict); 5793 if (!amend_opts) { 5794 return -EINVAL; 5795 } 5796 ret = qcrypto_block_amend_options(s->crypto, 5797 qcow2_crypto_hdr_read_func, 5798 qcow2_crypto_hdr_write_func, 5799 bs, 5800 amend_opts, 5801 force, 5802 errp); 5803 qapi_free_QCryptoBlockAmendOptions(amend_opts); 5804 if (ret < 0) { 5805 return ret; 5806 } 5807 } 5808 5809 if (s->refcount_bits != refcount_bits) { 5810 int refcount_order = ctz32(refcount_bits); 5811 5812 if (new_version < 3 && refcount_bits != 16) { 5813 error_setg(errp, "Refcount widths other than 16 bits require " 5814 "compatibility level 1.1 or above (use compat=1.1 or " 5815 "greater)"); 5816 return -EINVAL; 5817 } 5818 5819 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 5820 ret = qcow2_change_refcount_order(bs, refcount_order, 5821 &qcow2_amend_helper_cb, 5822 &helper_cb_info, errp); 5823 if (ret < 0) { 5824 return ret; 5825 } 5826 } 5827 5828 /* data-file-raw blocks backing files, so clear it first if requested */ 5829 if (data_file_raw) { 5830 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5831 } else { 5832 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5833 } 5834 5835 if (data_file) { 5836 g_free(s->image_data_file); 5837 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 5838 } 5839 5840 ret = qcow2_update_header(bs); 5841 if (ret < 0) { 5842 error_setg_errno(errp, -ret, "Failed to update the image header"); 5843 return ret; 5844 } 5845 5846 if (backing_file || backing_format) { 5847 if (g_strcmp0(backing_file, s->image_backing_file) || 5848 g_strcmp0(backing_format, s->image_backing_format)) { 5849 error_setg(errp, "Cannot amend the backing file"); 5850 error_append_hint(errp, 5851 "You can use 'qemu-img rebase' instead.\n"); 5852 return -EINVAL; 5853 } 5854 } 5855 5856 if (s->use_lazy_refcounts != lazy_refcounts) { 5857 if (lazy_refcounts) { 5858 if (new_version < 3) { 5859 error_setg(errp, "Lazy refcounts only supported with " 5860 "compatibility level 1.1 and above (use compat=1.1 " 5861 "or greater)"); 5862 return -EINVAL; 5863 } 5864 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5865 ret = qcow2_update_header(bs); 5866 if (ret < 0) { 5867 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5868 error_setg_errno(errp, -ret, "Failed to update the image header"); 5869 return ret; 5870 } 5871 s->use_lazy_refcounts = true; 5872 } else { 5873 /* make image clean first */ 5874 ret = qcow2_mark_clean(bs); 5875 if (ret < 0) { 5876 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5877 return ret; 5878 } 5879 /* now disallow lazy refcounts */ 5880 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5881 ret = qcow2_update_header(bs); 5882 if (ret < 0) { 5883 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5884 error_setg_errno(errp, -ret, "Failed to update the image header"); 5885 return ret; 5886 } 5887 s->use_lazy_refcounts = false; 5888 } 5889 } 5890 5891 if (new_size) { 5892 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, 5893 errp); 5894 if (!blk) { 5895 return -EPERM; 5896 } 5897 5898 /* 5899 * Amending image options should ensure that the image has 5900 * exactly the given new values, so pass exact=true here. 5901 */ 5902 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp); 5903 blk_unref(blk); 5904 if (ret < 0) { 5905 return ret; 5906 } 5907 } 5908 5909 /* Downgrade last (so unsupported features can be removed before) */ 5910 if (new_version < old_version) { 5911 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5912 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5913 &helper_cb_info, errp); 5914 if (ret < 0) { 5915 return ret; 5916 } 5917 } 5918 5919 return 0; 5920 } 5921 5922 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs, 5923 BlockdevAmendOptions *opts, 5924 bool force, 5925 Error **errp) 5926 { 5927 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2; 5928 BDRVQcow2State *s = bs->opaque; 5929 int ret = 0; 5930 5931 if (qopts->encrypt) { 5932 if (!s->crypto) { 5933 error_setg(errp, "image is not encrypted, can't amend"); 5934 return -EOPNOTSUPP; 5935 } 5936 5937 if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) { 5938 error_setg(errp, 5939 "Amend can't be used to change the qcow2 encryption format"); 5940 return -EOPNOTSUPP; 5941 } 5942 5943 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5944 error_setg(errp, 5945 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend"); 5946 return -EOPNOTSUPP; 5947 } 5948 5949 ret = qcrypto_block_amend_options(s->crypto, 5950 qcow2_crypto_hdr_read_func, 5951 qcow2_crypto_hdr_write_func, 5952 bs, 5953 qopts->encrypt, 5954 force, 5955 errp); 5956 } 5957 return ret; 5958 } 5959 5960 /* 5961 * If offset or size are negative, respectively, they will not be included in 5962 * the BLOCK_IMAGE_CORRUPTED event emitted. 5963 * fatal will be ignored for read-only BDS; corruptions found there will always 5964 * be considered non-fatal. 5965 */ 5966 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5967 int64_t size, const char *message_format, ...) 5968 { 5969 BDRVQcow2State *s = bs->opaque; 5970 const char *node_name; 5971 char *message; 5972 va_list ap; 5973 5974 fatal = fatal && bdrv_is_writable(bs); 5975 5976 if (s->signaled_corruption && 5977 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5978 { 5979 return; 5980 } 5981 5982 va_start(ap, message_format); 5983 message = g_strdup_vprintf(message_format, ap); 5984 va_end(ap); 5985 5986 if (fatal) { 5987 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 5988 "corruption events will be suppressed\n", message); 5989 } else { 5990 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 5991 "corruption events will be suppressed\n", message); 5992 } 5993 5994 node_name = bdrv_get_node_name(bs); 5995 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 5996 *node_name ? node_name : NULL, 5997 message, offset >= 0, offset, 5998 size >= 0, size, 5999 fatal); 6000 g_free(message); 6001 6002 if (fatal) { 6003 qcow2_mark_corrupt(bs); 6004 bs->drv = NULL; /* make BDS unusable */ 6005 } 6006 6007 s->signaled_corruption = true; 6008 } 6009 6010 #define QCOW_COMMON_OPTIONS \ 6011 { \ 6012 .name = BLOCK_OPT_SIZE, \ 6013 .type = QEMU_OPT_SIZE, \ 6014 .help = "Virtual disk size" \ 6015 }, \ 6016 { \ 6017 .name = BLOCK_OPT_COMPAT_LEVEL, \ 6018 .type = QEMU_OPT_STRING, \ 6019 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \ 6020 }, \ 6021 { \ 6022 .name = BLOCK_OPT_BACKING_FILE, \ 6023 .type = QEMU_OPT_STRING, \ 6024 .help = "File name of a base image" \ 6025 }, \ 6026 { \ 6027 .name = BLOCK_OPT_BACKING_FMT, \ 6028 .type = QEMU_OPT_STRING, \ 6029 .help = "Image format of the base image" \ 6030 }, \ 6031 { \ 6032 .name = BLOCK_OPT_DATA_FILE, \ 6033 .type = QEMU_OPT_STRING, \ 6034 .help = "File name of an external data file" \ 6035 }, \ 6036 { \ 6037 .name = BLOCK_OPT_DATA_FILE_RAW, \ 6038 .type = QEMU_OPT_BOOL, \ 6039 .help = "The external data file must stay valid " \ 6040 "as a raw image" \ 6041 }, \ 6042 { \ 6043 .name = BLOCK_OPT_LAZY_REFCOUNTS, \ 6044 .type = QEMU_OPT_BOOL, \ 6045 .help = "Postpone refcount updates", \ 6046 .def_value_str = "off" \ 6047 }, \ 6048 { \ 6049 .name = BLOCK_OPT_REFCOUNT_BITS, \ 6050 .type = QEMU_OPT_NUMBER, \ 6051 .help = "Width of a reference count entry in bits", \ 6052 .def_value_str = "16" \ 6053 } 6054 6055 static QemuOptsList qcow2_create_opts = { 6056 .name = "qcow2-create-opts", 6057 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 6058 .desc = { 6059 { \ 6060 .name = BLOCK_OPT_ENCRYPT, \ 6061 .type = QEMU_OPT_BOOL, \ 6062 .help = "Encrypt the image with format 'aes'. (Deprecated " \ 6063 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \ 6064 }, \ 6065 { \ 6066 .name = BLOCK_OPT_ENCRYPT_FORMAT, \ 6067 .type = QEMU_OPT_STRING, \ 6068 .help = "Encrypt the image, format choices: 'aes', 'luks'", \ 6069 }, \ 6070 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \ 6071 "ID of secret providing qcow AES key or LUKS passphrase"), \ 6072 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \ 6073 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \ 6074 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \ 6075 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \ 6076 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \ 6077 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \ 6078 { \ 6079 .name = BLOCK_OPT_CLUSTER_SIZE, \ 6080 .type = QEMU_OPT_SIZE, \ 6081 .help = "qcow2 cluster size", \ 6082 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \ 6083 }, \ 6084 { \ 6085 .name = BLOCK_OPT_EXTL2, \ 6086 .type = QEMU_OPT_BOOL, \ 6087 .help = "Extended L2 tables", \ 6088 .def_value_str = "off" \ 6089 }, \ 6090 { \ 6091 .name = BLOCK_OPT_PREALLOC, \ 6092 .type = QEMU_OPT_STRING, \ 6093 .help = "Preallocation mode (allowed values: off, " \ 6094 "metadata, falloc, full)" \ 6095 }, \ 6096 { \ 6097 .name = BLOCK_OPT_COMPRESSION_TYPE, \ 6098 .type = QEMU_OPT_STRING, \ 6099 .help = "Compression method used for image cluster " \ 6100 "compression", \ 6101 .def_value_str = "zlib" \ 6102 }, 6103 QCOW_COMMON_OPTIONS, 6104 { /* end of list */ } 6105 } 6106 }; 6107 6108 static QemuOptsList qcow2_amend_opts = { 6109 .name = "qcow2-amend-opts", 6110 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head), 6111 .desc = { 6112 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."), 6113 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."), 6114 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."), 6115 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."), 6116 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 6117 QCOW_COMMON_OPTIONS, 6118 { /* end of list */ } 6119 } 6120 }; 6121 6122 static const char *const qcow2_strong_runtime_opts[] = { 6123 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 6124 6125 NULL 6126 }; 6127 6128 BlockDriver bdrv_qcow2 = { 6129 .format_name = "qcow2", 6130 .instance_size = sizeof(BDRVQcow2State), 6131 .bdrv_probe = qcow2_probe, 6132 .bdrv_open = qcow2_open, 6133 .bdrv_close = qcow2_close, 6134 .bdrv_reopen_prepare = qcow2_reopen_prepare, 6135 .bdrv_reopen_commit = qcow2_reopen_commit, 6136 .bdrv_reopen_commit_post = qcow2_reopen_commit_post, 6137 .bdrv_reopen_abort = qcow2_reopen_abort, 6138 .bdrv_join_options = qcow2_join_options, 6139 .bdrv_child_perm = bdrv_default_perms, 6140 .bdrv_co_create_opts = qcow2_co_create_opts, 6141 .bdrv_co_create = qcow2_co_create, 6142 .bdrv_has_zero_init = qcow2_has_zero_init, 6143 .bdrv_co_block_status = qcow2_co_block_status, 6144 6145 .bdrv_co_preadv_part = qcow2_co_preadv_part, 6146 .bdrv_co_pwritev_part = qcow2_co_pwritev_part, 6147 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 6148 6149 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 6150 .bdrv_co_pdiscard = qcow2_co_pdiscard, 6151 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 6152 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 6153 .bdrv_co_truncate = qcow2_co_truncate, 6154 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part, 6155 .bdrv_make_empty = qcow2_make_empty, 6156 6157 .bdrv_snapshot_create = qcow2_snapshot_create, 6158 .bdrv_snapshot_goto = qcow2_snapshot_goto, 6159 .bdrv_snapshot_delete = qcow2_snapshot_delete, 6160 .bdrv_snapshot_list = qcow2_snapshot_list, 6161 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 6162 .bdrv_measure = qcow2_measure, 6163 .bdrv_co_get_info = qcow2_co_get_info, 6164 .bdrv_get_specific_info = qcow2_get_specific_info, 6165 6166 .bdrv_co_save_vmstate = qcow2_co_save_vmstate, 6167 .bdrv_co_load_vmstate = qcow2_co_load_vmstate, 6168 6169 .is_format = true, 6170 .supports_backing = true, 6171 .bdrv_co_change_backing_file = qcow2_co_change_backing_file, 6172 6173 .bdrv_refresh_limits = qcow2_refresh_limits, 6174 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 6175 .bdrv_inactivate = qcow2_inactivate, 6176 6177 .create_opts = &qcow2_create_opts, 6178 .amend_opts = &qcow2_amend_opts, 6179 .strong_runtime_opts = qcow2_strong_runtime_opts, 6180 .mutable_opts = mutable_opts, 6181 .bdrv_co_check = qcow2_co_check, 6182 .bdrv_amend_options = qcow2_amend_options, 6183 .bdrv_co_amend = qcow2_co_amend, 6184 6185 .bdrv_detach_aio_context = qcow2_detach_aio_context, 6186 .bdrv_attach_aio_context = qcow2_attach_aio_context, 6187 6188 .bdrv_supports_persistent_dirty_bitmap = 6189 qcow2_supports_persistent_dirty_bitmap, 6190 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap, 6191 .bdrv_co_remove_persistent_dirty_bitmap = 6192 qcow2_co_remove_persistent_dirty_bitmap, 6193 }; 6194 6195 static void bdrv_qcow2_init(void) 6196 { 6197 bdrv_register(&bdrv_qcow2); 6198 } 6199 6200 block_init(bdrv_qcow2_init); 6201