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 "qapi/qobject-input-visitor.h" 42 #include "qapi/qapi-visit-block-core.h" 43 #include "crypto.h" 44 #include "block/aio_task.h" 45 46 /* 47 Differences with QCOW: 48 49 - Support for multiple incremental snapshots. 50 - Memory management by reference counts. 51 - Clusters which have a reference count of one have the bit 52 QCOW_OFLAG_COPIED to optimize write performance. 53 - Size of compressed clusters is stored in sectors to reduce bit usage 54 in the cluster offsets. 55 - Support for storing additional data (such as the VM state) in the 56 snapshots. 57 - If a backing store is used, the cluster size is not constrained 58 (could be backported to QCOW). 59 - L2 tables have always a size of one cluster. 60 */ 61 62 63 typedef struct { 64 uint32_t magic; 65 uint32_t len; 66 } QEMU_PACKED QCowExtension; 67 68 #define QCOW2_EXT_MAGIC_END 0 69 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA 70 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 71 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 72 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 73 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 74 75 static int coroutine_fn 76 qcow2_co_preadv_compressed(BlockDriverState *bs, 77 uint64_t file_cluster_offset, 78 uint64_t offset, 79 uint64_t bytes, 80 QEMUIOVector *qiov, 81 size_t qiov_offset); 82 83 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) 84 { 85 const QCowHeader *cow_header = (const void *)buf; 86 87 if (buf_size >= sizeof(QCowHeader) && 88 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 89 be32_to_cpu(cow_header->version) >= 2) 90 return 100; 91 else 92 return 0; 93 } 94 95 96 static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, 97 uint8_t *buf, size_t buflen, 98 void *opaque, Error **errp) 99 { 100 BlockDriverState *bs = opaque; 101 BDRVQcow2State *s = bs->opaque; 102 ssize_t ret; 103 104 if ((offset + buflen) > s->crypto_header.length) { 105 error_setg(errp, "Request for data outside of extension header"); 106 return -1; 107 } 108 109 ret = bdrv_pread(bs->file, 110 s->crypto_header.offset + offset, buf, buflen); 111 if (ret < 0) { 112 error_setg_errno(errp, -ret, "Could not read encryption header"); 113 return -1; 114 } 115 return ret; 116 } 117 118 119 static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, 120 void *opaque, Error **errp) 121 { 122 BlockDriverState *bs = opaque; 123 BDRVQcow2State *s = bs->opaque; 124 int64_t ret; 125 int64_t clusterlen; 126 127 ret = qcow2_alloc_clusters(bs, headerlen); 128 if (ret < 0) { 129 error_setg_errno(errp, -ret, 130 "Cannot allocate cluster for LUKS header size %zu", 131 headerlen); 132 return -1; 133 } 134 135 s->crypto_header.length = headerlen; 136 s->crypto_header.offset = ret; 137 138 /* 139 * Zero fill all space in cluster so it has predictable 140 * content, as we may not initialize some regions of the 141 * header (eg only 1 out of 8 key slots will be initialized) 142 */ 143 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; 144 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); 145 ret = bdrv_pwrite_zeroes(bs->file, 146 ret, 147 clusterlen, 0); 148 if (ret < 0) { 149 error_setg_errno(errp, -ret, "Could not zero fill encryption header"); 150 return -1; 151 } 152 153 return ret; 154 } 155 156 157 static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, 158 const uint8_t *buf, size_t buflen, 159 void *opaque, Error **errp) 160 { 161 BlockDriverState *bs = opaque; 162 BDRVQcow2State *s = bs->opaque; 163 ssize_t ret; 164 165 if ((offset + buflen) > s->crypto_header.length) { 166 error_setg(errp, "Request for data outside of extension header"); 167 return -1; 168 } 169 170 ret = bdrv_pwrite(bs->file, 171 s->crypto_header.offset + offset, buf, buflen); 172 if (ret < 0) { 173 error_setg_errno(errp, -ret, "Could not read encryption header"); 174 return -1; 175 } 176 return ret; 177 } 178 179 static QDict* 180 qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp) 181 { 182 QDict *cryptoopts_qdict; 183 QDict *opts_qdict; 184 185 /* Extract "encrypt." options into a qdict */ 186 opts_qdict = qemu_opts_to_qdict(opts, NULL); 187 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); 188 qobject_unref(opts_qdict); 189 qdict_put_str(cryptoopts_qdict, "format", fmt); 190 return cryptoopts_qdict; 191 } 192 193 /* 194 * read qcow2 extension and fill bs 195 * start reading from start_offset 196 * finish reading upon magic of value 0 or when end_offset reached 197 * unknown magic is skipped (future extension this version knows nothing about) 198 * return 0 upon success, non-0 otherwise 199 */ 200 static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, 201 uint64_t end_offset, void **p_feature_table, 202 int flags, bool *need_update_header, 203 Error **errp) 204 { 205 BDRVQcow2State *s = bs->opaque; 206 QCowExtension ext; 207 uint64_t offset; 208 int ret; 209 Qcow2BitmapHeaderExt bitmaps_ext; 210 211 if (need_update_header != NULL) { 212 *need_update_header = false; 213 } 214 215 #ifdef DEBUG_EXT 216 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); 217 #endif 218 offset = start_offset; 219 while (offset < end_offset) { 220 221 #ifdef DEBUG_EXT 222 /* Sanity check */ 223 if (offset > s->cluster_size) 224 printf("qcow2_read_extension: suspicious offset %lu\n", offset); 225 226 printf("attempting to read extended header in offset %lu\n", offset); 227 #endif 228 229 ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext)); 230 if (ret < 0) { 231 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " 232 "pread fail from offset %" PRIu64, offset); 233 return 1; 234 } 235 ext.magic = be32_to_cpu(ext.magic); 236 ext.len = be32_to_cpu(ext.len); 237 offset += sizeof(ext); 238 #ifdef DEBUG_EXT 239 printf("ext.magic = 0x%x\n", ext.magic); 240 #endif 241 if (offset > end_offset || ext.len > end_offset - offset) { 242 error_setg(errp, "Header extension too large"); 243 return -EINVAL; 244 } 245 246 switch (ext.magic) { 247 case QCOW2_EXT_MAGIC_END: 248 return 0; 249 250 case QCOW2_EXT_MAGIC_BACKING_FORMAT: 251 if (ext.len >= sizeof(bs->backing_format)) { 252 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 253 " too large (>=%zu)", ext.len, 254 sizeof(bs->backing_format)); 255 return 2; 256 } 257 ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len); 258 if (ret < 0) { 259 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " 260 "Could not read format name"); 261 return 3; 262 } 263 bs->backing_format[ext.len] = '\0'; 264 s->image_backing_format = g_strdup(bs->backing_format); 265 #ifdef DEBUG_EXT 266 printf("Qcow2: Got format extension %s\n", bs->backing_format); 267 #endif 268 break; 269 270 case QCOW2_EXT_MAGIC_FEATURE_TABLE: 271 if (p_feature_table != NULL) { 272 void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); 273 ret = bdrv_pread(bs->file, offset , feature_table, ext.len); 274 if (ret < 0) { 275 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " 276 "Could not read table"); 277 return ret; 278 } 279 280 *p_feature_table = feature_table; 281 } 282 break; 283 284 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { 285 unsigned int cflags = 0; 286 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 287 error_setg(errp, "CRYPTO header extension only " 288 "expected with LUKS encryption method"); 289 return -EINVAL; 290 } 291 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { 292 error_setg(errp, "CRYPTO header extension size %u, " 293 "but expected size %zu", ext.len, 294 sizeof(Qcow2CryptoHeaderExtension)); 295 return -EINVAL; 296 } 297 298 ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len); 299 if (ret < 0) { 300 error_setg_errno(errp, -ret, 301 "Unable to read CRYPTO header extension"); 302 return ret; 303 } 304 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 305 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 306 307 if ((s->crypto_header.offset % s->cluster_size) != 0) { 308 error_setg(errp, "Encryption header offset '%" PRIu64 "' is " 309 "not a multiple of cluster size '%u'", 310 s->crypto_header.offset, s->cluster_size); 311 return -EINVAL; 312 } 313 314 if (flags & BDRV_O_NO_IO) { 315 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 316 } 317 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 318 qcow2_crypto_hdr_read_func, 319 bs, cflags, QCOW2_MAX_THREADS, errp); 320 if (!s->crypto) { 321 return -EINVAL; 322 } 323 } break; 324 325 case QCOW2_EXT_MAGIC_BITMAPS: 326 if (ext.len != sizeof(bitmaps_ext)) { 327 error_setg_errno(errp, -ret, "bitmaps_ext: " 328 "Invalid extension length"); 329 return -EINVAL; 330 } 331 332 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { 333 if (s->qcow_version < 3) { 334 /* Let's be a bit more specific */ 335 warn_report("This qcow2 v2 image contains bitmaps, but " 336 "they may have been modified by a program " 337 "without persistent bitmap support; so now " 338 "they must all be considered inconsistent"); 339 } else { 340 warn_report("a program lacking bitmap support " 341 "modified this file, so all bitmaps are now " 342 "considered inconsistent"); 343 } 344 error_printf("Some clusters may be leaked, " 345 "run 'qemu-img check -r' on the image " 346 "file to fix."); 347 if (need_update_header != NULL) { 348 /* Updating is needed to drop invalid bitmap extension. */ 349 *need_update_header = true; 350 } 351 break; 352 } 353 354 ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len); 355 if (ret < 0) { 356 error_setg_errno(errp, -ret, "bitmaps_ext: " 357 "Could not read ext header"); 358 return ret; 359 } 360 361 if (bitmaps_ext.reserved32 != 0) { 362 error_setg_errno(errp, -ret, "bitmaps_ext: " 363 "Reserved field is not zero"); 364 return -EINVAL; 365 } 366 367 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); 368 bitmaps_ext.bitmap_directory_size = 369 be64_to_cpu(bitmaps_ext.bitmap_directory_size); 370 bitmaps_ext.bitmap_directory_offset = 371 be64_to_cpu(bitmaps_ext.bitmap_directory_offset); 372 373 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { 374 error_setg(errp, 375 "bitmaps_ext: Image has %" PRIu32 " bitmaps, " 376 "exceeding the QEMU supported maximum of %d", 377 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); 378 return -EINVAL; 379 } 380 381 if (bitmaps_ext.nb_bitmaps == 0) { 382 error_setg(errp, "found bitmaps extension with zero bitmaps"); 383 return -EINVAL; 384 } 385 386 if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) { 387 error_setg(errp, "bitmaps_ext: " 388 "invalid bitmap directory offset"); 389 return -EINVAL; 390 } 391 392 if (bitmaps_ext.bitmap_directory_size > 393 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { 394 error_setg(errp, "bitmaps_ext: " 395 "bitmap directory size (%" PRIu64 ") exceeds " 396 "the maximum supported size (%d)", 397 bitmaps_ext.bitmap_directory_size, 398 QCOW2_MAX_BITMAP_DIRECTORY_SIZE); 399 return -EINVAL; 400 } 401 402 s->nb_bitmaps = bitmaps_ext.nb_bitmaps; 403 s->bitmap_directory_offset = 404 bitmaps_ext.bitmap_directory_offset; 405 s->bitmap_directory_size = 406 bitmaps_ext.bitmap_directory_size; 407 408 #ifdef DEBUG_EXT 409 printf("Qcow2: Got bitmaps extension: " 410 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", 411 s->bitmap_directory_offset, s->nb_bitmaps); 412 #endif 413 break; 414 415 case QCOW2_EXT_MAGIC_DATA_FILE: 416 { 417 s->image_data_file = g_malloc0(ext.len + 1); 418 ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len); 419 if (ret < 0) { 420 error_setg_errno(errp, -ret, 421 "ERROR: Could not read data file name"); 422 return ret; 423 } 424 #ifdef DEBUG_EXT 425 printf("Qcow2: Got external data file %s\n", s->image_data_file); 426 #endif 427 break; 428 } 429 430 default: 431 /* unknown magic - save it in case we need to rewrite the header */ 432 /* If you add a new feature, make sure to also update the fast 433 * path of qcow2_make_empty() to deal with it. */ 434 { 435 Qcow2UnknownHeaderExtension *uext; 436 437 uext = g_malloc0(sizeof(*uext) + ext.len); 438 uext->magic = ext.magic; 439 uext->len = ext.len; 440 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); 441 442 ret = bdrv_pread(bs->file, offset , uext->data, uext->len); 443 if (ret < 0) { 444 error_setg_errno(errp, -ret, "ERROR: unknown extension: " 445 "Could not read data"); 446 return ret; 447 } 448 } 449 break; 450 } 451 452 offset += ((ext.len + 7) & ~7); 453 } 454 455 return 0; 456 } 457 458 static void cleanup_unknown_header_ext(BlockDriverState *bs) 459 { 460 BDRVQcow2State *s = bs->opaque; 461 Qcow2UnknownHeaderExtension *uext, *next; 462 463 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { 464 QLIST_REMOVE(uext, next); 465 g_free(uext); 466 } 467 } 468 469 static void report_unsupported_feature(Error **errp, Qcow2Feature *table, 470 uint64_t mask) 471 { 472 g_autoptr(GString) features = g_string_sized_new(60); 473 474 while (table && table->name[0] != '\0') { 475 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { 476 if (mask & (1ULL << table->bit)) { 477 if (features->len > 0) { 478 g_string_append(features, ", "); 479 } 480 g_string_append_printf(features, "%.46s", table->name); 481 mask &= ~(1ULL << table->bit); 482 } 483 } 484 table++; 485 } 486 487 if (mask) { 488 if (features->len > 0) { 489 g_string_append(features, ", "); 490 } 491 g_string_append_printf(features, 492 "Unknown incompatible feature: %" PRIx64, mask); 493 } 494 495 error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); 496 } 497 498 /* 499 * Sets the dirty bit and flushes afterwards if necessary. 500 * 501 * The incompatible_features bit is only set if the image file header was 502 * updated successfully. Therefore it is not required to check the return 503 * value of this function. 504 */ 505 int qcow2_mark_dirty(BlockDriverState *bs) 506 { 507 BDRVQcow2State *s = bs->opaque; 508 uint64_t val; 509 int ret; 510 511 assert(s->qcow_version >= 3); 512 513 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 514 return 0; /* already dirty */ 515 } 516 517 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); 518 ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), 519 &val, sizeof(val)); 520 if (ret < 0) { 521 return ret; 522 } 523 ret = bdrv_flush(bs->file->bs); 524 if (ret < 0) { 525 return ret; 526 } 527 528 /* Only treat image as dirty if the header was updated successfully */ 529 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; 530 return 0; 531 } 532 533 /* 534 * Clears the dirty bit and flushes before if necessary. Only call this 535 * function when there are no pending requests, it does not guard against 536 * concurrent requests dirtying the image. 537 */ 538 static int qcow2_mark_clean(BlockDriverState *bs) 539 { 540 BDRVQcow2State *s = bs->opaque; 541 542 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 543 int ret; 544 545 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; 546 547 ret = qcow2_flush_caches(bs); 548 if (ret < 0) { 549 return ret; 550 } 551 552 return qcow2_update_header(bs); 553 } 554 return 0; 555 } 556 557 /* 558 * Marks the image as corrupt. 559 */ 560 int qcow2_mark_corrupt(BlockDriverState *bs) 561 { 562 BDRVQcow2State *s = bs->opaque; 563 564 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; 565 return qcow2_update_header(bs); 566 } 567 568 /* 569 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes 570 * before if necessary. 571 */ 572 int qcow2_mark_consistent(BlockDriverState *bs) 573 { 574 BDRVQcow2State *s = bs->opaque; 575 576 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 577 int ret = qcow2_flush_caches(bs); 578 if (ret < 0) { 579 return ret; 580 } 581 582 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; 583 return qcow2_update_header(bs); 584 } 585 return 0; 586 } 587 588 static void qcow2_add_check_result(BdrvCheckResult *out, 589 const BdrvCheckResult *src, 590 bool set_allocation_info) 591 { 592 out->corruptions += src->corruptions; 593 out->leaks += src->leaks; 594 out->check_errors += src->check_errors; 595 out->corruptions_fixed += src->corruptions_fixed; 596 out->leaks_fixed += src->leaks_fixed; 597 598 if (set_allocation_info) { 599 out->image_end_offset = src->image_end_offset; 600 out->bfi = src->bfi; 601 } 602 } 603 604 static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs, 605 BdrvCheckResult *result, 606 BdrvCheckMode fix) 607 { 608 BdrvCheckResult snapshot_res = {}; 609 BdrvCheckResult refcount_res = {}; 610 int ret; 611 612 memset(result, 0, sizeof(*result)); 613 614 ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix); 615 if (ret < 0) { 616 qcow2_add_check_result(result, &snapshot_res, false); 617 return ret; 618 } 619 620 ret = qcow2_check_refcounts(bs, &refcount_res, fix); 621 qcow2_add_check_result(result, &refcount_res, true); 622 if (ret < 0) { 623 qcow2_add_check_result(result, &snapshot_res, false); 624 return ret; 625 } 626 627 ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix); 628 qcow2_add_check_result(result, &snapshot_res, false); 629 if (ret < 0) { 630 return ret; 631 } 632 633 if (fix && result->check_errors == 0 && result->corruptions == 0) { 634 ret = qcow2_mark_clean(bs); 635 if (ret < 0) { 636 return ret; 637 } 638 return qcow2_mark_consistent(bs); 639 } 640 return ret; 641 } 642 643 static int coroutine_fn qcow2_co_check(BlockDriverState *bs, 644 BdrvCheckResult *result, 645 BdrvCheckMode fix) 646 { 647 BDRVQcow2State *s = bs->opaque; 648 int ret; 649 650 qemu_co_mutex_lock(&s->lock); 651 ret = qcow2_co_check_locked(bs, result, fix); 652 qemu_co_mutex_unlock(&s->lock); 653 return ret; 654 } 655 656 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 657 uint64_t entries, size_t entry_len, 658 int64_t max_size_bytes, const char *table_name, 659 Error **errp) 660 { 661 BDRVQcow2State *s = bs->opaque; 662 663 if (entries > max_size_bytes / entry_len) { 664 error_setg(errp, "%s too large", table_name); 665 return -EFBIG; 666 } 667 668 /* Use signed INT64_MAX as the maximum even for uint64_t header fields, 669 * because values will be passed to qemu functions taking int64_t. */ 670 if ((INT64_MAX - entries * entry_len < offset) || 671 (offset_into_cluster(s, offset) != 0)) { 672 error_setg(errp, "%s offset invalid", table_name); 673 return -EINVAL; 674 } 675 676 return 0; 677 } 678 679 static const char *const mutable_opts[] = { 680 QCOW2_OPT_LAZY_REFCOUNTS, 681 QCOW2_OPT_DISCARD_REQUEST, 682 QCOW2_OPT_DISCARD_SNAPSHOT, 683 QCOW2_OPT_DISCARD_OTHER, 684 QCOW2_OPT_OVERLAP, 685 QCOW2_OPT_OVERLAP_TEMPLATE, 686 QCOW2_OPT_OVERLAP_MAIN_HEADER, 687 QCOW2_OPT_OVERLAP_ACTIVE_L1, 688 QCOW2_OPT_OVERLAP_ACTIVE_L2, 689 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 690 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 691 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 692 QCOW2_OPT_OVERLAP_INACTIVE_L1, 693 QCOW2_OPT_OVERLAP_INACTIVE_L2, 694 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 695 QCOW2_OPT_CACHE_SIZE, 696 QCOW2_OPT_L2_CACHE_SIZE, 697 QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 698 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 699 QCOW2_OPT_CACHE_CLEAN_INTERVAL, 700 NULL 701 }; 702 703 static QemuOptsList qcow2_runtime_opts = { 704 .name = "qcow2", 705 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), 706 .desc = { 707 { 708 .name = QCOW2_OPT_LAZY_REFCOUNTS, 709 .type = QEMU_OPT_BOOL, 710 .help = "Postpone refcount updates", 711 }, 712 { 713 .name = QCOW2_OPT_DISCARD_REQUEST, 714 .type = QEMU_OPT_BOOL, 715 .help = "Pass guest discard requests to the layer below", 716 }, 717 { 718 .name = QCOW2_OPT_DISCARD_SNAPSHOT, 719 .type = QEMU_OPT_BOOL, 720 .help = "Generate discard requests when snapshot related space " 721 "is freed", 722 }, 723 { 724 .name = QCOW2_OPT_DISCARD_OTHER, 725 .type = QEMU_OPT_BOOL, 726 .help = "Generate discard requests when other clusters are freed", 727 }, 728 { 729 .name = QCOW2_OPT_OVERLAP, 730 .type = QEMU_OPT_STRING, 731 .help = "Selects which overlap checks to perform from a range of " 732 "templates (none, constant, cached, all)", 733 }, 734 { 735 .name = QCOW2_OPT_OVERLAP_TEMPLATE, 736 .type = QEMU_OPT_STRING, 737 .help = "Selects which overlap checks to perform from a range of " 738 "templates (none, constant, cached, all)", 739 }, 740 { 741 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, 742 .type = QEMU_OPT_BOOL, 743 .help = "Check for unintended writes into the main qcow2 header", 744 }, 745 { 746 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, 747 .type = QEMU_OPT_BOOL, 748 .help = "Check for unintended writes into the active L1 table", 749 }, 750 { 751 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, 752 .type = QEMU_OPT_BOOL, 753 .help = "Check for unintended writes into an active L2 table", 754 }, 755 { 756 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 757 .type = QEMU_OPT_BOOL, 758 .help = "Check for unintended writes into the refcount table", 759 }, 760 { 761 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 762 .type = QEMU_OPT_BOOL, 763 .help = "Check for unintended writes into a refcount block", 764 }, 765 { 766 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 767 .type = QEMU_OPT_BOOL, 768 .help = "Check for unintended writes into the snapshot table", 769 }, 770 { 771 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, 772 .type = QEMU_OPT_BOOL, 773 .help = "Check for unintended writes into an inactive L1 table", 774 }, 775 { 776 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, 777 .type = QEMU_OPT_BOOL, 778 .help = "Check for unintended writes into an inactive L2 table", 779 }, 780 { 781 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 782 .type = QEMU_OPT_BOOL, 783 .help = "Check for unintended writes into the bitmap directory", 784 }, 785 { 786 .name = QCOW2_OPT_CACHE_SIZE, 787 .type = QEMU_OPT_SIZE, 788 .help = "Maximum combined metadata (L2 tables and refcount blocks) " 789 "cache size", 790 }, 791 { 792 .name = QCOW2_OPT_L2_CACHE_SIZE, 793 .type = QEMU_OPT_SIZE, 794 .help = "Maximum L2 table cache size", 795 }, 796 { 797 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 798 .type = QEMU_OPT_SIZE, 799 .help = "Size of each entry in the L2 cache", 800 }, 801 { 802 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, 803 .type = QEMU_OPT_SIZE, 804 .help = "Maximum refcount block cache size", 805 }, 806 { 807 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, 808 .type = QEMU_OPT_NUMBER, 809 .help = "Clean unused cache entries after this time (in seconds)", 810 }, 811 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 812 "ID of secret providing qcow2 AES key or LUKS passphrase"), 813 { /* end of list */ } 814 }, 815 }; 816 817 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { 818 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, 819 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, 820 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, 821 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 822 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 823 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 824 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, 825 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, 826 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 827 }; 828 829 static void cache_clean_timer_cb(void *opaque) 830 { 831 BlockDriverState *bs = opaque; 832 BDRVQcow2State *s = bs->opaque; 833 qcow2_cache_clean_unused(s->l2_table_cache); 834 qcow2_cache_clean_unused(s->refcount_block_cache); 835 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 836 (int64_t) s->cache_clean_interval * 1000); 837 } 838 839 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) 840 { 841 BDRVQcow2State *s = bs->opaque; 842 if (s->cache_clean_interval > 0) { 843 s->cache_clean_timer = aio_timer_new(context, QEMU_CLOCK_VIRTUAL, 844 SCALE_MS, cache_clean_timer_cb, 845 bs); 846 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 847 (int64_t) s->cache_clean_interval * 1000); 848 } 849 } 850 851 static void cache_clean_timer_del(BlockDriverState *bs) 852 { 853 BDRVQcow2State *s = bs->opaque; 854 if (s->cache_clean_timer) { 855 timer_del(s->cache_clean_timer); 856 timer_free(s->cache_clean_timer); 857 s->cache_clean_timer = NULL; 858 } 859 } 860 861 static void qcow2_detach_aio_context(BlockDriverState *bs) 862 { 863 cache_clean_timer_del(bs); 864 } 865 866 static void qcow2_attach_aio_context(BlockDriverState *bs, 867 AioContext *new_context) 868 { 869 cache_clean_timer_init(bs, new_context); 870 } 871 872 static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, 873 uint64_t *l2_cache_size, 874 uint64_t *l2_cache_entry_size, 875 uint64_t *refcount_cache_size, Error **errp) 876 { 877 BDRVQcow2State *s = bs->opaque; 878 uint64_t combined_cache_size, l2_cache_max_setting; 879 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; 880 bool l2_cache_entry_size_set; 881 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; 882 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; 883 uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); 884 /* An L2 table is always one cluster in size so the max cache size 885 * should be a multiple of the cluster size. */ 886 uint64_t max_l2_cache = ROUND_UP(max_l2_entries * sizeof(uint64_t), 887 s->cluster_size); 888 889 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); 890 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); 891 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 892 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); 893 894 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); 895 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 896 DEFAULT_L2_CACHE_MAX_SIZE); 897 *refcount_cache_size = qemu_opt_get_size(opts, 898 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); 899 900 *l2_cache_entry_size = qemu_opt_get_size( 901 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); 902 903 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); 904 905 if (combined_cache_size_set) { 906 if (l2_cache_size_set && refcount_cache_size_set) { 907 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE 908 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " 909 "at the same time"); 910 return; 911 } else if (l2_cache_size_set && 912 (l2_cache_max_setting > combined_cache_size)) { 913 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " 914 QCOW2_OPT_CACHE_SIZE); 915 return; 916 } else if (*refcount_cache_size > combined_cache_size) { 917 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " 918 QCOW2_OPT_CACHE_SIZE); 919 return; 920 } 921 922 if (l2_cache_size_set) { 923 *refcount_cache_size = combined_cache_size - *l2_cache_size; 924 } else if (refcount_cache_size_set) { 925 *l2_cache_size = combined_cache_size - *refcount_cache_size; 926 } else { 927 /* Assign as much memory as possible to the L2 cache, and 928 * use the remainder for the refcount cache */ 929 if (combined_cache_size >= max_l2_cache + min_refcount_cache) { 930 *l2_cache_size = max_l2_cache; 931 *refcount_cache_size = combined_cache_size - *l2_cache_size; 932 } else { 933 *refcount_cache_size = 934 MIN(combined_cache_size, min_refcount_cache); 935 *l2_cache_size = combined_cache_size - *refcount_cache_size; 936 } 937 } 938 } 939 940 /* 941 * If the L2 cache is not enough to cover the whole disk then 942 * default to 4KB entries. Smaller entries reduce the cost of 943 * loads and evictions and increase I/O performance. 944 */ 945 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { 946 *l2_cache_entry_size = MIN(s->cluster_size, 4096); 947 } 948 949 /* l2_cache_size and refcount_cache_size are ensured to have at least 950 * their minimum values in qcow2_update_options_prepare() */ 951 952 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || 953 *l2_cache_entry_size > s->cluster_size || 954 !is_power_of_2(*l2_cache_entry_size)) { 955 error_setg(errp, "L2 cache entry size must be a power of two " 956 "between %d and the cluster size (%d)", 957 1 << MIN_CLUSTER_BITS, s->cluster_size); 958 return; 959 } 960 } 961 962 typedef struct Qcow2ReopenState { 963 Qcow2Cache *l2_table_cache; 964 Qcow2Cache *refcount_block_cache; 965 int l2_slice_size; /* Number of entries in a slice of the L2 table */ 966 bool use_lazy_refcounts; 967 int overlap_check; 968 bool discard_passthrough[QCOW2_DISCARD_MAX]; 969 uint64_t cache_clean_interval; 970 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 971 } Qcow2ReopenState; 972 973 static int qcow2_update_options_prepare(BlockDriverState *bs, 974 Qcow2ReopenState *r, 975 QDict *options, int flags, 976 Error **errp) 977 { 978 BDRVQcow2State *s = bs->opaque; 979 QemuOpts *opts = NULL; 980 const char *opt_overlap_check, *opt_overlap_check_template; 981 int overlap_check_template = 0; 982 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; 983 int i; 984 const char *encryptfmt; 985 QDict *encryptopts = NULL; 986 Error *local_err = NULL; 987 int ret; 988 989 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 990 encryptfmt = qdict_get_try_str(encryptopts, "format"); 991 992 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); 993 if (!qemu_opts_absorb_qdict(opts, options, &local_err)) { 994 error_propagate(errp, local_err); 995 ret = -EINVAL; 996 goto fail; 997 } 998 999 /* get L2 table/refcount block cache size from command line options */ 1000 read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, 1001 &refcount_cache_size, &local_err); 1002 if (local_err) { 1003 error_propagate(errp, local_err); 1004 ret = -EINVAL; 1005 goto fail; 1006 } 1007 1008 l2_cache_size /= l2_cache_entry_size; 1009 if (l2_cache_size < MIN_L2_CACHE_SIZE) { 1010 l2_cache_size = MIN_L2_CACHE_SIZE; 1011 } 1012 if (l2_cache_size > INT_MAX) { 1013 error_setg(errp, "L2 cache size too big"); 1014 ret = -EINVAL; 1015 goto fail; 1016 } 1017 1018 refcount_cache_size /= s->cluster_size; 1019 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { 1020 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; 1021 } 1022 if (refcount_cache_size > INT_MAX) { 1023 error_setg(errp, "Refcount cache size too big"); 1024 ret = -EINVAL; 1025 goto fail; 1026 } 1027 1028 /* alloc new L2 table/refcount block cache, flush old one */ 1029 if (s->l2_table_cache) { 1030 ret = qcow2_cache_flush(bs, s->l2_table_cache); 1031 if (ret) { 1032 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); 1033 goto fail; 1034 } 1035 } 1036 1037 if (s->refcount_block_cache) { 1038 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 1039 if (ret) { 1040 error_setg_errno(errp, -ret, 1041 "Failed to flush the refcount block cache"); 1042 goto fail; 1043 } 1044 } 1045 1046 r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t); 1047 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, 1048 l2_cache_entry_size); 1049 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, 1050 s->cluster_size); 1051 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { 1052 error_setg(errp, "Could not allocate metadata caches"); 1053 ret = -ENOMEM; 1054 goto fail; 1055 } 1056 1057 /* New interval for cache cleanup timer */ 1058 r->cache_clean_interval = 1059 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 1060 DEFAULT_CACHE_CLEAN_INTERVAL); 1061 #ifndef CONFIG_LINUX 1062 if (r->cache_clean_interval != 0) { 1063 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL 1064 " not supported on this host"); 1065 ret = -EINVAL; 1066 goto fail; 1067 } 1068 #endif 1069 if (r->cache_clean_interval > UINT_MAX) { 1070 error_setg(errp, "Cache clean interval too big"); 1071 ret = -EINVAL; 1072 goto fail; 1073 } 1074 1075 /* lazy-refcounts; flush if going from enabled to disabled */ 1076 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, 1077 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); 1078 if (r->use_lazy_refcounts && s->qcow_version < 3) { 1079 error_setg(errp, "Lazy refcounts require a qcow2 image with at least " 1080 "qemu 1.1 compatibility level"); 1081 ret = -EINVAL; 1082 goto fail; 1083 } 1084 1085 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { 1086 ret = qcow2_mark_clean(bs); 1087 if (ret < 0) { 1088 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); 1089 goto fail; 1090 } 1091 } 1092 1093 /* Overlap check options */ 1094 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); 1095 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); 1096 if (opt_overlap_check_template && opt_overlap_check && 1097 strcmp(opt_overlap_check_template, opt_overlap_check)) 1098 { 1099 error_setg(errp, "Conflicting values for qcow2 options '" 1100 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE 1101 "' ('%s')", opt_overlap_check, opt_overlap_check_template); 1102 ret = -EINVAL; 1103 goto fail; 1104 } 1105 if (!opt_overlap_check) { 1106 opt_overlap_check = opt_overlap_check_template ?: "cached"; 1107 } 1108 1109 if (!strcmp(opt_overlap_check, "none")) { 1110 overlap_check_template = 0; 1111 } else if (!strcmp(opt_overlap_check, "constant")) { 1112 overlap_check_template = QCOW2_OL_CONSTANT; 1113 } else if (!strcmp(opt_overlap_check, "cached")) { 1114 overlap_check_template = QCOW2_OL_CACHED; 1115 } else if (!strcmp(opt_overlap_check, "all")) { 1116 overlap_check_template = QCOW2_OL_ALL; 1117 } else { 1118 error_setg(errp, "Unsupported value '%s' for qcow2 option " 1119 "'overlap-check'. Allowed are any of the following: " 1120 "none, constant, cached, all", opt_overlap_check); 1121 ret = -EINVAL; 1122 goto fail; 1123 } 1124 1125 r->overlap_check = 0; 1126 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { 1127 /* overlap-check defines a template bitmask, but every flag may be 1128 * overwritten through the associated boolean option */ 1129 r->overlap_check |= 1130 qemu_opt_get_bool(opts, overlap_bool_option_names[i], 1131 overlap_check_template & (1 << i)) << i; 1132 } 1133 1134 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; 1135 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; 1136 r->discard_passthrough[QCOW2_DISCARD_REQUEST] = 1137 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, 1138 flags & BDRV_O_UNMAP); 1139 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = 1140 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); 1141 r->discard_passthrough[QCOW2_DISCARD_OTHER] = 1142 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); 1143 1144 switch (s->crypt_method_header) { 1145 case QCOW_CRYPT_NONE: 1146 if (encryptfmt) { 1147 error_setg(errp, "No encryption in image header, but options " 1148 "specified format '%s'", encryptfmt); 1149 ret = -EINVAL; 1150 goto fail; 1151 } 1152 break; 1153 1154 case QCOW_CRYPT_AES: 1155 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 1156 error_setg(errp, 1157 "Header reported 'aes' encryption format but " 1158 "options specify '%s'", encryptfmt); 1159 ret = -EINVAL; 1160 goto fail; 1161 } 1162 qdict_put_str(encryptopts, "format", "qcow"); 1163 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1164 break; 1165 1166 case QCOW_CRYPT_LUKS: 1167 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { 1168 error_setg(errp, 1169 "Header reported 'luks' encryption format but " 1170 "options specify '%s'", encryptfmt); 1171 ret = -EINVAL; 1172 goto fail; 1173 } 1174 qdict_put_str(encryptopts, "format", "luks"); 1175 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1176 break; 1177 1178 default: 1179 error_setg(errp, "Unsupported encryption method %d", 1180 s->crypt_method_header); 1181 break; 1182 } 1183 if (s->crypt_method_header != QCOW_CRYPT_NONE && !r->crypto_opts) { 1184 ret = -EINVAL; 1185 goto fail; 1186 } 1187 1188 ret = 0; 1189 fail: 1190 qobject_unref(encryptopts); 1191 qemu_opts_del(opts); 1192 opts = NULL; 1193 return ret; 1194 } 1195 1196 static void qcow2_update_options_commit(BlockDriverState *bs, 1197 Qcow2ReopenState *r) 1198 { 1199 BDRVQcow2State *s = bs->opaque; 1200 int i; 1201 1202 if (s->l2_table_cache) { 1203 qcow2_cache_destroy(s->l2_table_cache); 1204 } 1205 if (s->refcount_block_cache) { 1206 qcow2_cache_destroy(s->refcount_block_cache); 1207 } 1208 s->l2_table_cache = r->l2_table_cache; 1209 s->refcount_block_cache = r->refcount_block_cache; 1210 s->l2_slice_size = r->l2_slice_size; 1211 1212 s->overlap_check = r->overlap_check; 1213 s->use_lazy_refcounts = r->use_lazy_refcounts; 1214 1215 for (i = 0; i < QCOW2_DISCARD_MAX; i++) { 1216 s->discard_passthrough[i] = r->discard_passthrough[i]; 1217 } 1218 1219 if (s->cache_clean_interval != r->cache_clean_interval) { 1220 cache_clean_timer_del(bs); 1221 s->cache_clean_interval = r->cache_clean_interval; 1222 cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); 1223 } 1224 1225 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1226 s->crypto_opts = r->crypto_opts; 1227 } 1228 1229 static void qcow2_update_options_abort(BlockDriverState *bs, 1230 Qcow2ReopenState *r) 1231 { 1232 if (r->l2_table_cache) { 1233 qcow2_cache_destroy(r->l2_table_cache); 1234 } 1235 if (r->refcount_block_cache) { 1236 qcow2_cache_destroy(r->refcount_block_cache); 1237 } 1238 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); 1239 } 1240 1241 static int qcow2_update_options(BlockDriverState *bs, QDict *options, 1242 int flags, Error **errp) 1243 { 1244 Qcow2ReopenState r = {}; 1245 int ret; 1246 1247 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); 1248 if (ret >= 0) { 1249 qcow2_update_options_commit(bs, &r); 1250 } else { 1251 qcow2_update_options_abort(bs, &r); 1252 } 1253 1254 return ret; 1255 } 1256 1257 static int validate_compression_type(BDRVQcow2State *s, Error **errp) 1258 { 1259 switch (s->compression_type) { 1260 case QCOW2_COMPRESSION_TYPE_ZLIB: 1261 #ifdef CONFIG_ZSTD 1262 case QCOW2_COMPRESSION_TYPE_ZSTD: 1263 #endif 1264 break; 1265 1266 default: 1267 error_setg(errp, "qcow2: unknown compression type: %u", 1268 s->compression_type); 1269 return -ENOTSUP; 1270 } 1271 1272 /* 1273 * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB 1274 * the incompatible feature flag must be set 1275 */ 1276 if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) { 1277 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 1278 error_setg(errp, "qcow2: Compression type incompatible feature " 1279 "bit must not be set"); 1280 return -EINVAL; 1281 } 1282 } else { 1283 if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) { 1284 error_setg(errp, "qcow2: Compression type incompatible feature " 1285 "bit must be set"); 1286 return -EINVAL; 1287 } 1288 } 1289 1290 return 0; 1291 } 1292 1293 /* Called with s->lock held. */ 1294 static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, 1295 int flags, Error **errp) 1296 { 1297 BDRVQcow2State *s = bs->opaque; 1298 unsigned int len, i; 1299 int ret = 0; 1300 QCowHeader header; 1301 Error *local_err = NULL; 1302 uint64_t ext_end; 1303 uint64_t l1_vm_state_index; 1304 bool update_header = false; 1305 1306 ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); 1307 if (ret < 0) { 1308 error_setg_errno(errp, -ret, "Could not read qcow2 header"); 1309 goto fail; 1310 } 1311 header.magic = be32_to_cpu(header.magic); 1312 header.version = be32_to_cpu(header.version); 1313 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 1314 header.backing_file_size = be32_to_cpu(header.backing_file_size); 1315 header.size = be64_to_cpu(header.size); 1316 header.cluster_bits = be32_to_cpu(header.cluster_bits); 1317 header.crypt_method = be32_to_cpu(header.crypt_method); 1318 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 1319 header.l1_size = be32_to_cpu(header.l1_size); 1320 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); 1321 header.refcount_table_clusters = 1322 be32_to_cpu(header.refcount_table_clusters); 1323 header.snapshots_offset = be64_to_cpu(header.snapshots_offset); 1324 header.nb_snapshots = be32_to_cpu(header.nb_snapshots); 1325 1326 if (header.magic != QCOW_MAGIC) { 1327 error_setg(errp, "Image is not in qcow2 format"); 1328 ret = -EINVAL; 1329 goto fail; 1330 } 1331 if (header.version < 2 || header.version > 3) { 1332 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); 1333 ret = -ENOTSUP; 1334 goto fail; 1335 } 1336 1337 s->qcow_version = header.version; 1338 1339 /* Initialise cluster size */ 1340 if (header.cluster_bits < MIN_CLUSTER_BITS || 1341 header.cluster_bits > MAX_CLUSTER_BITS) { 1342 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, 1343 header.cluster_bits); 1344 ret = -EINVAL; 1345 goto fail; 1346 } 1347 1348 s->cluster_bits = header.cluster_bits; 1349 s->cluster_size = 1 << s->cluster_bits; 1350 1351 /* Initialise version 3 header fields */ 1352 if (header.version == 2) { 1353 header.incompatible_features = 0; 1354 header.compatible_features = 0; 1355 header.autoclear_features = 0; 1356 header.refcount_order = 4; 1357 header.header_length = 72; 1358 } else { 1359 header.incompatible_features = 1360 be64_to_cpu(header.incompatible_features); 1361 header.compatible_features = be64_to_cpu(header.compatible_features); 1362 header.autoclear_features = be64_to_cpu(header.autoclear_features); 1363 header.refcount_order = be32_to_cpu(header.refcount_order); 1364 header.header_length = be32_to_cpu(header.header_length); 1365 1366 if (header.header_length < 104) { 1367 error_setg(errp, "qcow2 header too short"); 1368 ret = -EINVAL; 1369 goto fail; 1370 } 1371 } 1372 1373 if (header.header_length > s->cluster_size) { 1374 error_setg(errp, "qcow2 header exceeds cluster size"); 1375 ret = -EINVAL; 1376 goto fail; 1377 } 1378 1379 if (header.header_length > sizeof(header)) { 1380 s->unknown_header_fields_size = header.header_length - sizeof(header); 1381 s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); 1382 ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields, 1383 s->unknown_header_fields_size); 1384 if (ret < 0) { 1385 error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " 1386 "fields"); 1387 goto fail; 1388 } 1389 } 1390 1391 if (header.backing_file_offset > s->cluster_size) { 1392 error_setg(errp, "Invalid backing file offset"); 1393 ret = -EINVAL; 1394 goto fail; 1395 } 1396 1397 if (header.backing_file_offset) { 1398 ext_end = header.backing_file_offset; 1399 } else { 1400 ext_end = 1 << header.cluster_bits; 1401 } 1402 1403 /* Handle feature bits */ 1404 s->incompatible_features = header.incompatible_features; 1405 s->compatible_features = header.compatible_features; 1406 s->autoclear_features = header.autoclear_features; 1407 1408 /* 1409 * Handle compression type 1410 * Older qcow2 images don't contain the compression type header. 1411 * Distinguish them by the header length and use 1412 * the only valid (default) compression type in that case 1413 */ 1414 if (header.header_length > offsetof(QCowHeader, compression_type)) { 1415 s->compression_type = header.compression_type; 1416 } else { 1417 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 1418 } 1419 1420 ret = validate_compression_type(s, errp); 1421 if (ret) { 1422 goto fail; 1423 } 1424 1425 if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { 1426 void *feature_table = NULL; 1427 qcow2_read_extensions(bs, header.header_length, ext_end, 1428 &feature_table, flags, NULL, NULL); 1429 report_unsupported_feature(errp, feature_table, 1430 s->incompatible_features & 1431 ~QCOW2_INCOMPAT_MASK); 1432 ret = -ENOTSUP; 1433 g_free(feature_table); 1434 goto fail; 1435 } 1436 1437 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 1438 /* Corrupt images may not be written to unless they are being repaired 1439 */ 1440 if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { 1441 error_setg(errp, "qcow2: Image is corrupt; cannot be opened " 1442 "read/write"); 1443 ret = -EACCES; 1444 goto fail; 1445 } 1446 } 1447 1448 /* Check support for various header values */ 1449 if (header.refcount_order > 6) { 1450 error_setg(errp, "Reference count entry width too large; may not " 1451 "exceed 64 bits"); 1452 ret = -EINVAL; 1453 goto fail; 1454 } 1455 s->refcount_order = header.refcount_order; 1456 s->refcount_bits = 1 << s->refcount_order; 1457 s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); 1458 s->refcount_max += s->refcount_max - 1; 1459 1460 s->crypt_method_header = header.crypt_method; 1461 if (s->crypt_method_header) { 1462 if (bdrv_uses_whitelist() && 1463 s->crypt_method_header == QCOW_CRYPT_AES) { 1464 error_setg(errp, 1465 "Use of AES-CBC encrypted qcow2 images is no longer " 1466 "supported in system emulators"); 1467 error_append_hint(errp, 1468 "You can use 'qemu-img convert' to convert your " 1469 "image to an alternative supported format, such " 1470 "as unencrypted qcow2, or raw with the LUKS " 1471 "format instead.\n"); 1472 ret = -ENOSYS; 1473 goto fail; 1474 } 1475 1476 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1477 s->crypt_physical_offset = false; 1478 } else { 1479 /* Assuming LUKS and any future crypt methods we 1480 * add will all use physical offsets, due to the 1481 * fact that the alternative is insecure... */ 1482 s->crypt_physical_offset = true; 1483 } 1484 1485 bs->encrypted = true; 1486 } 1487 1488 s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ 1489 s->l2_size = 1 << s->l2_bits; 1490 /* 2^(s->refcount_order - 3) is the refcount width in bytes */ 1491 s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); 1492 s->refcount_block_size = 1 << s->refcount_block_bits; 1493 bs->total_sectors = header.size / BDRV_SECTOR_SIZE; 1494 s->csize_shift = (62 - (s->cluster_bits - 8)); 1495 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; 1496 s->cluster_offset_mask = (1LL << s->csize_shift) - 1; 1497 1498 s->refcount_table_offset = header.refcount_table_offset; 1499 s->refcount_table_size = 1500 header.refcount_table_clusters << (s->cluster_bits - 3); 1501 1502 if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { 1503 error_setg(errp, "Image does not contain a reference count table"); 1504 ret = -EINVAL; 1505 goto fail; 1506 } 1507 1508 ret = qcow2_validate_table(bs, s->refcount_table_offset, 1509 header.refcount_table_clusters, 1510 s->cluster_size, QCOW_MAX_REFTABLE_SIZE, 1511 "Reference count table", errp); 1512 if (ret < 0) { 1513 goto fail; 1514 } 1515 1516 if (!(flags & BDRV_O_CHECK)) { 1517 /* 1518 * The total size in bytes of the snapshot table is checked in 1519 * qcow2_read_snapshots() because the size of each snapshot is 1520 * variable and we don't know it yet. 1521 * Here we only check the offset and number of snapshots. 1522 */ 1523 ret = qcow2_validate_table(bs, header.snapshots_offset, 1524 header.nb_snapshots, 1525 sizeof(QCowSnapshotHeader), 1526 sizeof(QCowSnapshotHeader) * 1527 QCOW_MAX_SNAPSHOTS, 1528 "Snapshot table", errp); 1529 if (ret < 0) { 1530 goto fail; 1531 } 1532 } 1533 1534 /* read the level 1 table */ 1535 ret = qcow2_validate_table(bs, header.l1_table_offset, 1536 header.l1_size, sizeof(uint64_t), 1537 QCOW_MAX_L1_SIZE, "Active L1 table", errp); 1538 if (ret < 0) { 1539 goto fail; 1540 } 1541 s->l1_size = header.l1_size; 1542 s->l1_table_offset = header.l1_table_offset; 1543 1544 l1_vm_state_index = size_to_l1(s, header.size); 1545 if (l1_vm_state_index > INT_MAX) { 1546 error_setg(errp, "Image is too big"); 1547 ret = -EFBIG; 1548 goto fail; 1549 } 1550 s->l1_vm_state_index = l1_vm_state_index; 1551 1552 /* the L1 table must contain at least enough entries to put 1553 header.size bytes */ 1554 if (s->l1_size < s->l1_vm_state_index) { 1555 error_setg(errp, "L1 table is too small"); 1556 ret = -EINVAL; 1557 goto fail; 1558 } 1559 1560 if (s->l1_size > 0) { 1561 s->l1_table = qemu_try_blockalign(bs->file->bs, 1562 s->l1_size * sizeof(uint64_t)); 1563 if (s->l1_table == NULL) { 1564 error_setg(errp, "Could not allocate L1 table"); 1565 ret = -ENOMEM; 1566 goto fail; 1567 } 1568 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, 1569 s->l1_size * sizeof(uint64_t)); 1570 if (ret < 0) { 1571 error_setg_errno(errp, -ret, "Could not read L1 table"); 1572 goto fail; 1573 } 1574 for(i = 0;i < s->l1_size; i++) { 1575 s->l1_table[i] = be64_to_cpu(s->l1_table[i]); 1576 } 1577 } 1578 1579 /* Parse driver-specific options */ 1580 ret = qcow2_update_options(bs, options, flags, errp); 1581 if (ret < 0) { 1582 goto fail; 1583 } 1584 1585 s->flags = flags; 1586 1587 ret = qcow2_refcount_init(bs); 1588 if (ret != 0) { 1589 error_setg_errno(errp, -ret, "Could not initialize refcount handling"); 1590 goto fail; 1591 } 1592 1593 QLIST_INIT(&s->cluster_allocs); 1594 QTAILQ_INIT(&s->discards); 1595 1596 /* read qcow2 extensions */ 1597 if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, 1598 flags, &update_header, &local_err)) { 1599 error_propagate(errp, local_err); 1600 ret = -EINVAL; 1601 goto fail; 1602 } 1603 1604 /* Open external data file */ 1605 s->data_file = bdrv_open_child(NULL, options, "data-file", bs, 1606 &child_of_bds, BDRV_CHILD_DATA, 1607 true, &local_err); 1608 if (local_err) { 1609 error_propagate(errp, local_err); 1610 ret = -EINVAL; 1611 goto fail; 1612 } 1613 1614 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { 1615 if (!s->data_file && s->image_data_file) { 1616 s->data_file = bdrv_open_child(s->image_data_file, options, 1617 "data-file", bs, &child_of_bds, 1618 BDRV_CHILD_DATA, false, errp); 1619 if (!s->data_file) { 1620 ret = -EINVAL; 1621 goto fail; 1622 } 1623 } 1624 if (!s->data_file) { 1625 error_setg(errp, "'data-file' is required for this image"); 1626 ret = -EINVAL; 1627 goto fail; 1628 } 1629 1630 /* No data here */ 1631 bs->file->role &= ~BDRV_CHILD_DATA; 1632 1633 /* Must succeed because we have given up permissions if anything */ 1634 bdrv_child_refresh_perms(bs, bs->file, &error_abort); 1635 } else { 1636 if (s->data_file) { 1637 error_setg(errp, "'data-file' can only be set for images with an " 1638 "external data file"); 1639 ret = -EINVAL; 1640 goto fail; 1641 } 1642 1643 s->data_file = bs->file; 1644 1645 if (data_file_is_raw(bs)) { 1646 error_setg(errp, "data-file-raw requires a data file"); 1647 ret = -EINVAL; 1648 goto fail; 1649 } 1650 } 1651 1652 /* qcow2_read_extension may have set up the crypto context 1653 * if the crypt method needs a header region, some methods 1654 * don't need header extensions, so must check here 1655 */ 1656 if (s->crypt_method_header && !s->crypto) { 1657 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1658 unsigned int cflags = 0; 1659 if (flags & BDRV_O_NO_IO) { 1660 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 1661 } 1662 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 1663 NULL, NULL, cflags, 1664 QCOW2_MAX_THREADS, errp); 1665 if (!s->crypto) { 1666 ret = -EINVAL; 1667 goto fail; 1668 } 1669 } else if (!(flags & BDRV_O_NO_IO)) { 1670 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1671 s->crypt_method_header); 1672 ret = -EINVAL; 1673 goto fail; 1674 } 1675 } 1676 1677 /* read the backing file name */ 1678 if (header.backing_file_offset != 0) { 1679 len = header.backing_file_size; 1680 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1681 len >= sizeof(bs->backing_file)) { 1682 error_setg(errp, "Backing file name too long"); 1683 ret = -EINVAL; 1684 goto fail; 1685 } 1686 ret = bdrv_pread(bs->file, header.backing_file_offset, 1687 bs->auto_backing_file, len); 1688 if (ret < 0) { 1689 error_setg_errno(errp, -ret, "Could not read backing file name"); 1690 goto fail; 1691 } 1692 bs->auto_backing_file[len] = '\0'; 1693 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1694 bs->auto_backing_file); 1695 s->image_backing_file = g_strdup(bs->auto_backing_file); 1696 } 1697 1698 /* 1699 * Internal snapshots; skip reading them in check mode, because 1700 * we do not need them then, and we do not want to abort because 1701 * of a broken table. 1702 */ 1703 if (!(flags & BDRV_O_CHECK)) { 1704 s->snapshots_offset = header.snapshots_offset; 1705 s->nb_snapshots = header.nb_snapshots; 1706 1707 ret = qcow2_read_snapshots(bs, errp); 1708 if (ret < 0) { 1709 goto fail; 1710 } 1711 } 1712 1713 /* Clear unknown autoclear feature bits */ 1714 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1715 update_header = 1716 update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE); 1717 if (update_header) { 1718 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1719 } 1720 1721 /* == Handle persistent dirty bitmaps == 1722 * 1723 * We want load dirty bitmaps in three cases: 1724 * 1725 * 1. Normal open of the disk in active mode, not related to invalidation 1726 * after migration. 1727 * 1728 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1729 * bitmaps are _not_ migrating through migration channel, i.e. 1730 * 'dirty-bitmaps' capability is disabled. 1731 * 1732 * 3. Invalidation of source vm after failed or canceled migration. 1733 * This is a very interesting case. There are two possible types of 1734 * bitmaps: 1735 * 1736 * A. Stored on inactivation and removed. They should be loaded from the 1737 * image. 1738 * 1739 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1740 * the migration channel (with dirty-bitmaps capability). 1741 * 1742 * On the other hand, there are two possible sub-cases: 1743 * 1744 * 3.1 disk was changed by somebody else while were inactive. In this 1745 * case all in-RAM dirty bitmaps (both persistent and not) are 1746 * definitely invalid. And we don't have any method to determine 1747 * this. 1748 * 1749 * Simple and safe thing is to just drop all the bitmaps of type B on 1750 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1751 * 1752 * On the other hand, resuming source vm, if disk was already changed 1753 * is a bad thing anyway: not only bitmaps, the whole vm state is 1754 * out of sync with disk. 1755 * 1756 * This means, that user or management tool, who for some reason 1757 * decided to resume source vm, after disk was already changed by 1758 * target vm, should at least drop all dirty bitmaps by hand. 1759 * 1760 * So, we can ignore this case for now, but TODO: "generation" 1761 * extension for qcow2, to determine, that image was changed after 1762 * last inactivation. And if it is changed, we will drop (or at least 1763 * mark as 'invalid' all the bitmaps of type B, both persistent 1764 * and not). 1765 * 1766 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1767 * to disk ('dirty-bitmaps' capability disabled), or not saved 1768 * ('dirty-bitmaps' capability enabled), but we don't need to care 1769 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1770 * and not stored has flag IN_USE=1 in the image and will be skipped 1771 * on loading. 1772 * 1773 * One remaining possible case when we don't want load bitmaps: 1774 * 1775 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1776 * will be loaded on invalidation, no needs try loading them before) 1777 */ 1778 1779 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1780 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1781 bool header_updated = qcow2_load_dirty_bitmaps(bs, &local_err); 1782 if (local_err != NULL) { 1783 error_propagate(errp, local_err); 1784 ret = -EINVAL; 1785 goto fail; 1786 } 1787 1788 update_header = update_header && !header_updated; 1789 } 1790 1791 if (update_header) { 1792 ret = qcow2_update_header(bs); 1793 if (ret < 0) { 1794 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1795 goto fail; 1796 } 1797 } 1798 1799 bs->supported_zero_flags = header.version >= 3 ? 1800 BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; 1801 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; 1802 1803 /* Repair image if dirty */ 1804 if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only && 1805 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1806 BdrvCheckResult result = {0}; 1807 1808 ret = qcow2_co_check_locked(bs, &result, 1809 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1810 if (ret < 0 || result.check_errors) { 1811 if (ret >= 0) { 1812 ret = -EIO; 1813 } 1814 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1815 goto fail; 1816 } 1817 } 1818 1819 #ifdef DEBUG_ALLOC 1820 { 1821 BdrvCheckResult result = {0}; 1822 qcow2_check_refcounts(bs, &result, 0); 1823 } 1824 #endif 1825 1826 qemu_co_queue_init(&s->thread_task_queue); 1827 1828 return ret; 1829 1830 fail: 1831 g_free(s->image_data_file); 1832 if (has_data_file(bs)) { 1833 bdrv_unref_child(bs, s->data_file); 1834 s->data_file = NULL; 1835 } 1836 g_free(s->unknown_header_fields); 1837 cleanup_unknown_header_ext(bs); 1838 qcow2_free_snapshots(bs); 1839 qcow2_refcount_close(bs); 1840 qemu_vfree(s->l1_table); 1841 /* else pre-write overlap checks in cache_destroy may crash */ 1842 s->l1_table = NULL; 1843 cache_clean_timer_del(bs); 1844 if (s->l2_table_cache) { 1845 qcow2_cache_destroy(s->l2_table_cache); 1846 } 1847 if (s->refcount_block_cache) { 1848 qcow2_cache_destroy(s->refcount_block_cache); 1849 } 1850 qcrypto_block_free(s->crypto); 1851 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1852 return ret; 1853 } 1854 1855 typedef struct QCow2OpenCo { 1856 BlockDriverState *bs; 1857 QDict *options; 1858 int flags; 1859 Error **errp; 1860 int ret; 1861 } QCow2OpenCo; 1862 1863 static void coroutine_fn qcow2_open_entry(void *opaque) 1864 { 1865 QCow2OpenCo *qoc = opaque; 1866 BDRVQcow2State *s = qoc->bs->opaque; 1867 1868 qemu_co_mutex_lock(&s->lock); 1869 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 1870 qemu_co_mutex_unlock(&s->lock); 1871 } 1872 1873 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1874 Error **errp) 1875 { 1876 BDRVQcow2State *s = bs->opaque; 1877 QCow2OpenCo qoc = { 1878 .bs = bs, 1879 .options = options, 1880 .flags = flags, 1881 .errp = errp, 1882 .ret = -EINPROGRESS 1883 }; 1884 1885 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 1886 BDRV_CHILD_IMAGE, false, errp); 1887 if (!bs->file) { 1888 return -EINVAL; 1889 } 1890 1891 /* Initialise locks */ 1892 qemu_co_mutex_init(&s->lock); 1893 1894 if (qemu_in_coroutine()) { 1895 /* From bdrv_co_create. */ 1896 qcow2_open_entry(&qoc); 1897 } else { 1898 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1899 qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry, &qoc)); 1900 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 1901 } 1902 return qoc.ret; 1903 } 1904 1905 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1906 { 1907 BDRVQcow2State *s = bs->opaque; 1908 1909 if (bs->encrypted) { 1910 /* Encryption works on a sector granularity */ 1911 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1912 } 1913 bs->bl.pwrite_zeroes_alignment = s->cluster_size; 1914 bs->bl.pdiscard_alignment = s->cluster_size; 1915 } 1916 1917 static int qcow2_reopen_prepare(BDRVReopenState *state, 1918 BlockReopenQueue *queue, Error **errp) 1919 { 1920 Qcow2ReopenState *r; 1921 int ret; 1922 1923 r = g_new0(Qcow2ReopenState, 1); 1924 state->opaque = r; 1925 1926 ret = qcow2_update_options_prepare(state->bs, r, state->options, 1927 state->flags, errp); 1928 if (ret < 0) { 1929 goto fail; 1930 } 1931 1932 /* We need to write out any unwritten data if we reopen read-only. */ 1933 if ((state->flags & BDRV_O_RDWR) == 0) { 1934 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 1935 if (ret < 0) { 1936 goto fail; 1937 } 1938 1939 ret = bdrv_flush(state->bs); 1940 if (ret < 0) { 1941 goto fail; 1942 } 1943 1944 ret = qcow2_mark_clean(state->bs); 1945 if (ret < 0) { 1946 goto fail; 1947 } 1948 } 1949 1950 return 0; 1951 1952 fail: 1953 qcow2_update_options_abort(state->bs, r); 1954 g_free(r); 1955 return ret; 1956 } 1957 1958 static void qcow2_reopen_commit(BDRVReopenState *state) 1959 { 1960 qcow2_update_options_commit(state->bs, state->opaque); 1961 g_free(state->opaque); 1962 } 1963 1964 static void qcow2_reopen_commit_post(BDRVReopenState *state) 1965 { 1966 if (state->flags & BDRV_O_RDWR) { 1967 Error *local_err = NULL; 1968 1969 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { 1970 /* 1971 * This is not fatal, bitmaps just left read-only, so all following 1972 * writes will fail. User can remove read-only bitmaps to unblock 1973 * writes or retry reopen. 1974 */ 1975 error_reportf_err(local_err, 1976 "%s: Failed to make dirty bitmaps writable: ", 1977 bdrv_get_node_name(state->bs)); 1978 } 1979 } 1980 } 1981 1982 static void qcow2_reopen_abort(BDRVReopenState *state) 1983 { 1984 qcow2_update_options_abort(state->bs, state->opaque); 1985 g_free(state->opaque); 1986 } 1987 1988 static void qcow2_join_options(QDict *options, QDict *old_options) 1989 { 1990 bool has_new_overlap_template = 1991 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 1992 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 1993 bool has_new_total_cache_size = 1994 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 1995 bool has_all_cache_options; 1996 1997 /* New overlap template overrides all old overlap options */ 1998 if (has_new_overlap_template) { 1999 qdict_del(old_options, QCOW2_OPT_OVERLAP); 2000 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 2001 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 2002 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 2003 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 2004 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 2005 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 2006 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 2007 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 2008 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 2009 } 2010 2011 /* New total cache size overrides all old options */ 2012 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 2013 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 2014 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2015 } 2016 2017 qdict_join(options, old_options, false); 2018 2019 /* 2020 * If after merging all cache size options are set, an old total size is 2021 * overwritten. Do keep all options, however, if all three are new. The 2022 * resulting error message is what we want to happen. 2023 */ 2024 has_all_cache_options = 2025 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 2026 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 2027 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2028 2029 if (has_all_cache_options && !has_new_total_cache_size) { 2030 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 2031 } 2032 } 2033 2034 static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs, 2035 bool want_zero, 2036 int64_t offset, int64_t count, 2037 int64_t *pnum, int64_t *map, 2038 BlockDriverState **file) 2039 { 2040 BDRVQcow2State *s = bs->opaque; 2041 uint64_t cluster_offset; 2042 unsigned int bytes; 2043 int ret, status = 0; 2044 2045 qemu_co_mutex_lock(&s->lock); 2046 2047 if (!s->metadata_preallocation_checked) { 2048 ret = qcow2_detect_metadata_preallocation(bs); 2049 s->metadata_preallocation = (ret == 1); 2050 s->metadata_preallocation_checked = true; 2051 } 2052 2053 bytes = MIN(INT_MAX, count); 2054 ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset); 2055 qemu_co_mutex_unlock(&s->lock); 2056 if (ret < 0) { 2057 return ret; 2058 } 2059 2060 *pnum = bytes; 2061 2062 if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) && 2063 !s->crypto) { 2064 *map = cluster_offset | offset_into_cluster(s, offset); 2065 *file = s->data_file->bs; 2066 status |= BDRV_BLOCK_OFFSET_VALID; 2067 } 2068 if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) { 2069 status |= BDRV_BLOCK_ZERO; 2070 } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { 2071 status |= BDRV_BLOCK_DATA; 2072 } 2073 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && 2074 (status & BDRV_BLOCK_OFFSET_VALID)) 2075 { 2076 status |= BDRV_BLOCK_RECURSE; 2077 } 2078 return status; 2079 } 2080 2081 static coroutine_fn int qcow2_handle_l2meta(BlockDriverState *bs, 2082 QCowL2Meta **pl2meta, 2083 bool link_l2) 2084 { 2085 int ret = 0; 2086 QCowL2Meta *l2meta = *pl2meta; 2087 2088 while (l2meta != NULL) { 2089 QCowL2Meta *next; 2090 2091 if (link_l2) { 2092 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 2093 if (ret) { 2094 goto out; 2095 } 2096 } else { 2097 qcow2_alloc_cluster_abort(bs, l2meta); 2098 } 2099 2100 /* Take the request off the list of running requests */ 2101 if (l2meta->nb_clusters != 0) { 2102 QLIST_REMOVE(l2meta, next_in_flight); 2103 } 2104 2105 qemu_co_queue_restart_all(&l2meta->dependent_requests); 2106 2107 next = l2meta->next; 2108 g_free(l2meta); 2109 l2meta = next; 2110 } 2111 out: 2112 *pl2meta = l2meta; 2113 return ret; 2114 } 2115 2116 static coroutine_fn int 2117 qcow2_co_preadv_encrypted(BlockDriverState *bs, 2118 uint64_t file_cluster_offset, 2119 uint64_t offset, 2120 uint64_t bytes, 2121 QEMUIOVector *qiov, 2122 uint64_t qiov_offset) 2123 { 2124 int ret; 2125 BDRVQcow2State *s = bs->opaque; 2126 uint8_t *buf; 2127 2128 assert(bs->encrypted && s->crypto); 2129 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2130 2131 /* 2132 * For encrypted images, read everything into a temporary 2133 * contiguous buffer on which the AES functions can work. 2134 * Also, decryption in a separate buffer is better as it 2135 * prevents the guest from learning information about the 2136 * encrypted nature of the virtual disk. 2137 */ 2138 2139 buf = qemu_try_blockalign(s->data_file->bs, bytes); 2140 if (buf == NULL) { 2141 return -ENOMEM; 2142 } 2143 2144 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 2145 ret = bdrv_co_pread(s->data_file, 2146 file_cluster_offset + offset_into_cluster(s, offset), 2147 bytes, buf, 0); 2148 if (ret < 0) { 2149 goto fail; 2150 } 2151 2152 if (qcow2_co_decrypt(bs, 2153 file_cluster_offset + offset_into_cluster(s, offset), 2154 offset, buf, bytes) < 0) 2155 { 2156 ret = -EIO; 2157 goto fail; 2158 } 2159 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); 2160 2161 fail: 2162 qemu_vfree(buf); 2163 2164 return ret; 2165 } 2166 2167 typedef struct Qcow2AioTask { 2168 AioTask task; 2169 2170 BlockDriverState *bs; 2171 QCow2ClusterType cluster_type; /* only for read */ 2172 uint64_t file_cluster_offset; 2173 uint64_t offset; 2174 uint64_t bytes; 2175 QEMUIOVector *qiov; 2176 uint64_t qiov_offset; 2177 QCowL2Meta *l2meta; /* only for write */ 2178 } Qcow2AioTask; 2179 2180 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); 2181 static coroutine_fn int qcow2_add_task(BlockDriverState *bs, 2182 AioTaskPool *pool, 2183 AioTaskFunc func, 2184 QCow2ClusterType cluster_type, 2185 uint64_t file_cluster_offset, 2186 uint64_t offset, 2187 uint64_t bytes, 2188 QEMUIOVector *qiov, 2189 size_t qiov_offset, 2190 QCowL2Meta *l2meta) 2191 { 2192 Qcow2AioTask local_task; 2193 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; 2194 2195 *task = (Qcow2AioTask) { 2196 .task.func = func, 2197 .bs = bs, 2198 .cluster_type = cluster_type, 2199 .qiov = qiov, 2200 .file_cluster_offset = file_cluster_offset, 2201 .offset = offset, 2202 .bytes = bytes, 2203 .qiov_offset = qiov_offset, 2204 .l2meta = l2meta, 2205 }; 2206 2207 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, 2208 func == qcow2_co_preadv_task_entry ? "read" : "write", 2209 cluster_type, file_cluster_offset, offset, bytes, 2210 qiov, qiov_offset); 2211 2212 if (!pool) { 2213 return func(&task->task); 2214 } 2215 2216 aio_task_pool_start_task(pool, &task->task); 2217 2218 return 0; 2219 } 2220 2221 static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs, 2222 QCow2ClusterType cluster_type, 2223 uint64_t file_cluster_offset, 2224 uint64_t offset, uint64_t bytes, 2225 QEMUIOVector *qiov, 2226 size_t qiov_offset) 2227 { 2228 BDRVQcow2State *s = bs->opaque; 2229 int offset_in_cluster = offset_into_cluster(s, offset); 2230 2231 switch (cluster_type) { 2232 case QCOW2_CLUSTER_ZERO_PLAIN: 2233 case QCOW2_CLUSTER_ZERO_ALLOC: 2234 /* Both zero types are handled in qcow2_co_preadv_part */ 2235 g_assert_not_reached(); 2236 2237 case QCOW2_CLUSTER_UNALLOCATED: 2238 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ 2239 2240 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2241 return bdrv_co_preadv_part(bs->backing, offset, bytes, 2242 qiov, qiov_offset, 0); 2243 2244 case QCOW2_CLUSTER_COMPRESSED: 2245 return qcow2_co_preadv_compressed(bs, file_cluster_offset, 2246 offset, bytes, qiov, qiov_offset); 2247 2248 case QCOW2_CLUSTER_NORMAL: 2249 assert(offset_into_cluster(s, file_cluster_offset) == 0); 2250 if (bs->encrypted) { 2251 return qcow2_co_preadv_encrypted(bs, file_cluster_offset, 2252 offset, bytes, qiov, qiov_offset); 2253 } 2254 2255 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 2256 return bdrv_co_preadv_part(s->data_file, 2257 file_cluster_offset + offset_in_cluster, 2258 bytes, qiov, qiov_offset, 0); 2259 2260 default: 2261 g_assert_not_reached(); 2262 } 2263 2264 g_assert_not_reached(); 2265 } 2266 2267 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task) 2268 { 2269 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2270 2271 assert(!t->l2meta); 2272 2273 return qcow2_co_preadv_task(t->bs, t->cluster_type, t->file_cluster_offset, 2274 t->offset, t->bytes, t->qiov, t->qiov_offset); 2275 } 2276 2277 static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs, 2278 uint64_t offset, uint64_t bytes, 2279 QEMUIOVector *qiov, 2280 size_t qiov_offset, int flags) 2281 { 2282 BDRVQcow2State *s = bs->opaque; 2283 int ret = 0; 2284 unsigned int cur_bytes; /* number of bytes in current iteration */ 2285 uint64_t cluster_offset = 0; 2286 AioTaskPool *aio = NULL; 2287 2288 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2289 /* prepare next request */ 2290 cur_bytes = MIN(bytes, INT_MAX); 2291 if (s->crypto) { 2292 cur_bytes = MIN(cur_bytes, 2293 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2294 } 2295 2296 qemu_co_mutex_lock(&s->lock); 2297 ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset); 2298 qemu_co_mutex_unlock(&s->lock); 2299 if (ret < 0) { 2300 goto out; 2301 } 2302 2303 if (ret == QCOW2_CLUSTER_ZERO_PLAIN || 2304 ret == QCOW2_CLUSTER_ZERO_ALLOC || 2305 (ret == QCOW2_CLUSTER_UNALLOCATED && !bs->backing)) 2306 { 2307 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2308 } else { 2309 if (!aio && cur_bytes != bytes) { 2310 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2311 } 2312 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, ret, 2313 cluster_offset, offset, cur_bytes, 2314 qiov, qiov_offset, NULL); 2315 if (ret < 0) { 2316 goto out; 2317 } 2318 } 2319 2320 bytes -= cur_bytes; 2321 offset += cur_bytes; 2322 qiov_offset += cur_bytes; 2323 } 2324 2325 out: 2326 if (aio) { 2327 aio_task_pool_wait_all(aio); 2328 if (ret == 0) { 2329 ret = aio_task_pool_status(aio); 2330 } 2331 g_free(aio); 2332 } 2333 2334 return ret; 2335 } 2336 2337 /* Check if it's possible to merge a write request with the writing of 2338 * the data from the COW regions */ 2339 static bool merge_cow(uint64_t offset, unsigned bytes, 2340 QEMUIOVector *qiov, size_t qiov_offset, 2341 QCowL2Meta *l2meta) 2342 { 2343 QCowL2Meta *m; 2344 2345 for (m = l2meta; m != NULL; m = m->next) { 2346 /* If both COW regions are empty then there's nothing to merge */ 2347 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2348 continue; 2349 } 2350 2351 /* If COW regions are handled already, skip this too */ 2352 if (m->skip_cow) { 2353 continue; 2354 } 2355 2356 /* The data (middle) region must be immediately after the 2357 * start region */ 2358 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2359 continue; 2360 } 2361 2362 /* The end region must be immediately after the data (middle) 2363 * region */ 2364 if (m->offset + m->cow_end.offset != offset + bytes) { 2365 continue; 2366 } 2367 2368 /* Make sure that adding both COW regions to the QEMUIOVector 2369 * does not exceed IOV_MAX */ 2370 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { 2371 continue; 2372 } 2373 2374 m->data_qiov = qiov; 2375 m->data_qiov_offset = qiov_offset; 2376 return true; 2377 } 2378 2379 return false; 2380 } 2381 2382 static bool is_unallocated(BlockDriverState *bs, int64_t offset, int64_t bytes) 2383 { 2384 int64_t nr; 2385 return !bytes || 2386 (!bdrv_is_allocated_above(bs, NULL, false, offset, bytes, &nr) && 2387 nr == bytes); 2388 } 2389 2390 static bool is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) 2391 { 2392 /* 2393 * This check is designed for optimization shortcut so it must be 2394 * efficient. 2395 * Instead of is_zero(), use is_unallocated() as it is faster (but not 2396 * as accurate and can result in false negatives). 2397 */ 2398 return is_unallocated(bs, m->offset + m->cow_start.offset, 2399 m->cow_start.nb_bytes) && 2400 is_unallocated(bs, m->offset + m->cow_end.offset, 2401 m->cow_end.nb_bytes); 2402 } 2403 2404 static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) 2405 { 2406 BDRVQcow2State *s = bs->opaque; 2407 QCowL2Meta *m; 2408 2409 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { 2410 return 0; 2411 } 2412 2413 if (bs->encrypted) { 2414 return 0; 2415 } 2416 2417 for (m = l2meta; m != NULL; m = m->next) { 2418 int ret; 2419 2420 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { 2421 continue; 2422 } 2423 2424 if (!is_zero_cow(bs, m)) { 2425 continue; 2426 } 2427 2428 /* 2429 * instead of writing zero COW buffers, 2430 * efficiently zero out the whole clusters 2431 */ 2432 2433 ret = qcow2_pre_write_overlap_check(bs, 0, m->alloc_offset, 2434 m->nb_clusters * s->cluster_size, 2435 true); 2436 if (ret < 0) { 2437 return ret; 2438 } 2439 2440 BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); 2441 ret = bdrv_co_pwrite_zeroes(s->data_file, m->alloc_offset, 2442 m->nb_clusters * s->cluster_size, 2443 BDRV_REQ_NO_FALLBACK); 2444 if (ret < 0) { 2445 if (ret != -ENOTSUP && ret != -EAGAIN) { 2446 return ret; 2447 } 2448 continue; 2449 } 2450 2451 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); 2452 m->skip_cow = true; 2453 } 2454 return 0; 2455 } 2456 2457 /* 2458 * qcow2_co_pwritev_task 2459 * Called with s->lock unlocked 2460 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must 2461 * not use it somehow after qcow2_co_pwritev_task() call 2462 */ 2463 static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs, 2464 uint64_t file_cluster_offset, 2465 uint64_t offset, uint64_t bytes, 2466 QEMUIOVector *qiov, 2467 uint64_t qiov_offset, 2468 QCowL2Meta *l2meta) 2469 { 2470 int ret; 2471 BDRVQcow2State *s = bs->opaque; 2472 void *crypt_buf = NULL; 2473 int offset_in_cluster = offset_into_cluster(s, offset); 2474 QEMUIOVector encrypted_qiov; 2475 2476 if (bs->encrypted) { 2477 assert(s->crypto); 2478 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2479 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); 2480 if (crypt_buf == NULL) { 2481 ret = -ENOMEM; 2482 goto out_unlocked; 2483 } 2484 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); 2485 2486 if (qcow2_co_encrypt(bs, file_cluster_offset + offset_in_cluster, 2487 offset, crypt_buf, bytes) < 0) 2488 { 2489 ret = -EIO; 2490 goto out_unlocked; 2491 } 2492 2493 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); 2494 qiov = &encrypted_qiov; 2495 qiov_offset = 0; 2496 } 2497 2498 /* Try to efficiently initialize the physical space with zeroes */ 2499 ret = handle_alloc_space(bs, l2meta); 2500 if (ret < 0) { 2501 goto out_unlocked; 2502 } 2503 2504 /* 2505 * If we need to do COW, check if it's possible to merge the 2506 * writing of the guest data together with that of the COW regions. 2507 * If it's not possible (or not necessary) then write the 2508 * guest data now. 2509 */ 2510 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { 2511 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); 2512 trace_qcow2_writev_data(qemu_coroutine_self(), 2513 file_cluster_offset + offset_in_cluster); 2514 ret = bdrv_co_pwritev_part(s->data_file, 2515 file_cluster_offset + offset_in_cluster, 2516 bytes, qiov, qiov_offset, 0); 2517 if (ret < 0) { 2518 goto out_unlocked; 2519 } 2520 } 2521 2522 qemu_co_mutex_lock(&s->lock); 2523 2524 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2525 goto out_locked; 2526 2527 out_unlocked: 2528 qemu_co_mutex_lock(&s->lock); 2529 2530 out_locked: 2531 qcow2_handle_l2meta(bs, &l2meta, false); 2532 qemu_co_mutex_unlock(&s->lock); 2533 2534 qemu_vfree(crypt_buf); 2535 2536 return ret; 2537 } 2538 2539 static coroutine_fn int qcow2_co_pwritev_task_entry(AioTask *task) 2540 { 2541 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2542 2543 assert(!t->cluster_type); 2544 2545 return qcow2_co_pwritev_task(t->bs, t->file_cluster_offset, 2546 t->offset, t->bytes, t->qiov, t->qiov_offset, 2547 t->l2meta); 2548 } 2549 2550 static coroutine_fn int qcow2_co_pwritev_part( 2551 BlockDriverState *bs, uint64_t offset, uint64_t bytes, 2552 QEMUIOVector *qiov, size_t qiov_offset, int flags) 2553 { 2554 BDRVQcow2State *s = bs->opaque; 2555 int offset_in_cluster; 2556 int ret; 2557 unsigned int cur_bytes; /* number of sectors in current iteration */ 2558 uint64_t cluster_offset; 2559 QCowL2Meta *l2meta = NULL; 2560 AioTaskPool *aio = NULL; 2561 2562 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2563 2564 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2565 2566 l2meta = NULL; 2567 2568 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2569 offset_in_cluster = offset_into_cluster(s, offset); 2570 cur_bytes = MIN(bytes, INT_MAX); 2571 if (bs->encrypted) { 2572 cur_bytes = MIN(cur_bytes, 2573 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2574 - offset_in_cluster); 2575 } 2576 2577 qemu_co_mutex_lock(&s->lock); 2578 2579 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 2580 &cluster_offset, &l2meta); 2581 if (ret < 0) { 2582 goto out_locked; 2583 } 2584 2585 assert(offset_into_cluster(s, cluster_offset) == 0); 2586 2587 ret = qcow2_pre_write_overlap_check(bs, 0, 2588 cluster_offset + offset_in_cluster, 2589 cur_bytes, true); 2590 if (ret < 0) { 2591 goto out_locked; 2592 } 2593 2594 qemu_co_mutex_unlock(&s->lock); 2595 2596 if (!aio && cur_bytes != bytes) { 2597 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2598 } 2599 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, 2600 cluster_offset, offset, cur_bytes, 2601 qiov, qiov_offset, l2meta); 2602 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ 2603 if (ret < 0) { 2604 goto fail_nometa; 2605 } 2606 2607 bytes -= cur_bytes; 2608 offset += cur_bytes; 2609 qiov_offset += cur_bytes; 2610 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2611 } 2612 ret = 0; 2613 2614 qemu_co_mutex_lock(&s->lock); 2615 2616 out_locked: 2617 qcow2_handle_l2meta(bs, &l2meta, false); 2618 2619 qemu_co_mutex_unlock(&s->lock); 2620 2621 fail_nometa: 2622 if (aio) { 2623 aio_task_pool_wait_all(aio); 2624 if (ret == 0) { 2625 ret = aio_task_pool_status(aio); 2626 } 2627 g_free(aio); 2628 } 2629 2630 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2631 2632 return ret; 2633 } 2634 2635 static int qcow2_inactivate(BlockDriverState *bs) 2636 { 2637 BDRVQcow2State *s = bs->opaque; 2638 int ret, result = 0; 2639 Error *local_err = NULL; 2640 2641 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); 2642 if (local_err != NULL) { 2643 result = -EINVAL; 2644 error_reportf_err(local_err, "Lost persistent bitmaps during " 2645 "inactivation of node '%s': ", 2646 bdrv_get_device_or_node_name(bs)); 2647 } 2648 2649 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2650 if (ret) { 2651 result = ret; 2652 error_report("Failed to flush the L2 table cache: %s", 2653 strerror(-ret)); 2654 } 2655 2656 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2657 if (ret) { 2658 result = ret; 2659 error_report("Failed to flush the refcount block cache: %s", 2660 strerror(-ret)); 2661 } 2662 2663 if (result == 0) { 2664 qcow2_mark_clean(bs); 2665 } 2666 2667 return result; 2668 } 2669 2670 static void qcow2_close(BlockDriverState *bs) 2671 { 2672 BDRVQcow2State *s = bs->opaque; 2673 qemu_vfree(s->l1_table); 2674 /* else pre-write overlap checks in cache_destroy may crash */ 2675 s->l1_table = NULL; 2676 2677 if (!(s->flags & BDRV_O_INACTIVE)) { 2678 qcow2_inactivate(bs); 2679 } 2680 2681 cache_clean_timer_del(bs); 2682 qcow2_cache_destroy(s->l2_table_cache); 2683 qcow2_cache_destroy(s->refcount_block_cache); 2684 2685 qcrypto_block_free(s->crypto); 2686 s->crypto = NULL; 2687 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 2688 2689 g_free(s->unknown_header_fields); 2690 cleanup_unknown_header_ext(bs); 2691 2692 g_free(s->image_data_file); 2693 g_free(s->image_backing_file); 2694 g_free(s->image_backing_format); 2695 2696 if (has_data_file(bs)) { 2697 bdrv_unref_child(bs, s->data_file); 2698 s->data_file = NULL; 2699 } 2700 2701 qcow2_refcount_close(bs); 2702 qcow2_free_snapshots(bs); 2703 } 2704 2705 static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs, 2706 Error **errp) 2707 { 2708 BDRVQcow2State *s = bs->opaque; 2709 int flags = s->flags; 2710 QCryptoBlock *crypto = NULL; 2711 QDict *options; 2712 Error *local_err = NULL; 2713 int ret; 2714 2715 /* 2716 * Backing files are read-only which makes all of their metadata immutable, 2717 * that means we don't have to worry about reopening them here. 2718 */ 2719 2720 crypto = s->crypto; 2721 s->crypto = NULL; 2722 2723 qcow2_close(bs); 2724 2725 memset(s, 0, sizeof(BDRVQcow2State)); 2726 options = qdict_clone_shallow(bs->options); 2727 2728 flags &= ~BDRV_O_INACTIVE; 2729 qemu_co_mutex_lock(&s->lock); 2730 ret = qcow2_do_open(bs, options, flags, &local_err); 2731 qemu_co_mutex_unlock(&s->lock); 2732 qobject_unref(options); 2733 if (local_err) { 2734 error_propagate_prepend(errp, local_err, 2735 "Could not reopen qcow2 layer: "); 2736 bs->drv = NULL; 2737 return; 2738 } else if (ret < 0) { 2739 error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); 2740 bs->drv = NULL; 2741 return; 2742 } 2743 2744 s->crypto = crypto; 2745 } 2746 2747 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2748 size_t len, size_t buflen) 2749 { 2750 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2751 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2752 2753 if (buflen < ext_len) { 2754 return -ENOSPC; 2755 } 2756 2757 *ext_backing_fmt = (QCowExtension) { 2758 .magic = cpu_to_be32(magic), 2759 .len = cpu_to_be32(len), 2760 }; 2761 2762 if (len) { 2763 memcpy(buf + sizeof(QCowExtension), s, len); 2764 } 2765 2766 return ext_len; 2767 } 2768 2769 /* 2770 * Updates the qcow2 header, including the variable length parts of it, i.e. 2771 * the backing file name and all extensions. qcow2 was not designed to allow 2772 * such changes, so if we run out of space (we can only use the first cluster) 2773 * this function may fail. 2774 * 2775 * Returns 0 on success, -errno in error cases. 2776 */ 2777 int qcow2_update_header(BlockDriverState *bs) 2778 { 2779 BDRVQcow2State *s = bs->opaque; 2780 QCowHeader *header; 2781 char *buf; 2782 size_t buflen = s->cluster_size; 2783 int ret; 2784 uint64_t total_size; 2785 uint32_t refcount_table_clusters; 2786 size_t header_length; 2787 Qcow2UnknownHeaderExtension *uext; 2788 2789 buf = qemu_blockalign(bs, buflen); 2790 2791 /* Header structure */ 2792 header = (QCowHeader*) buf; 2793 2794 if (buflen < sizeof(*header)) { 2795 ret = -ENOSPC; 2796 goto fail; 2797 } 2798 2799 header_length = sizeof(*header) + s->unknown_header_fields_size; 2800 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2801 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2802 2803 ret = validate_compression_type(s, NULL); 2804 if (ret) { 2805 goto fail; 2806 } 2807 2808 *header = (QCowHeader) { 2809 /* Version 2 fields */ 2810 .magic = cpu_to_be32(QCOW_MAGIC), 2811 .version = cpu_to_be32(s->qcow_version), 2812 .backing_file_offset = 0, 2813 .backing_file_size = 0, 2814 .cluster_bits = cpu_to_be32(s->cluster_bits), 2815 .size = cpu_to_be64(total_size), 2816 .crypt_method = cpu_to_be32(s->crypt_method_header), 2817 .l1_size = cpu_to_be32(s->l1_size), 2818 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2819 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2820 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2821 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2822 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2823 2824 /* Version 3 fields */ 2825 .incompatible_features = cpu_to_be64(s->incompatible_features), 2826 .compatible_features = cpu_to_be64(s->compatible_features), 2827 .autoclear_features = cpu_to_be64(s->autoclear_features), 2828 .refcount_order = cpu_to_be32(s->refcount_order), 2829 .header_length = cpu_to_be32(header_length), 2830 .compression_type = s->compression_type, 2831 }; 2832 2833 /* For older versions, write a shorter header */ 2834 switch (s->qcow_version) { 2835 case 2: 2836 ret = offsetof(QCowHeader, incompatible_features); 2837 break; 2838 case 3: 2839 ret = sizeof(*header); 2840 break; 2841 default: 2842 ret = -EINVAL; 2843 goto fail; 2844 } 2845 2846 buf += ret; 2847 buflen -= ret; 2848 memset(buf, 0, buflen); 2849 2850 /* Preserve any unknown field in the header */ 2851 if (s->unknown_header_fields_size) { 2852 if (buflen < s->unknown_header_fields_size) { 2853 ret = -ENOSPC; 2854 goto fail; 2855 } 2856 2857 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 2858 buf += s->unknown_header_fields_size; 2859 buflen -= s->unknown_header_fields_size; 2860 } 2861 2862 /* Backing file format header extension */ 2863 if (s->image_backing_format) { 2864 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 2865 s->image_backing_format, 2866 strlen(s->image_backing_format), 2867 buflen); 2868 if (ret < 0) { 2869 goto fail; 2870 } 2871 2872 buf += ret; 2873 buflen -= ret; 2874 } 2875 2876 /* External data file header extension */ 2877 if (has_data_file(bs) && s->image_data_file) { 2878 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 2879 s->image_data_file, strlen(s->image_data_file), 2880 buflen); 2881 if (ret < 0) { 2882 goto fail; 2883 } 2884 2885 buf += ret; 2886 buflen -= ret; 2887 } 2888 2889 /* Full disk encryption header pointer extension */ 2890 if (s->crypto_header.offset != 0) { 2891 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 2892 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 2893 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 2894 &s->crypto_header, sizeof(s->crypto_header), 2895 buflen); 2896 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 2897 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 2898 if (ret < 0) { 2899 goto fail; 2900 } 2901 buf += ret; 2902 buflen -= ret; 2903 } 2904 2905 /* 2906 * Feature table. A mere 8 feature names occupies 392 bytes, and 2907 * when coupled with the v3 minimum header of 104 bytes plus the 2908 * 8-byte end-of-extension marker, that would leave only 8 bytes 2909 * for a backing file name in an image with 512-byte clusters. 2910 * Thus, we choose to omit this header for cluster sizes 4k and 2911 * smaller. 2912 */ 2913 if (s->qcow_version >= 3 && s->cluster_size > 4096) { 2914 static const Qcow2Feature features[] = { 2915 { 2916 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2917 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 2918 .name = "dirty bit", 2919 }, 2920 { 2921 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2922 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 2923 .name = "corrupt bit", 2924 }, 2925 { 2926 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2927 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 2928 .name = "external data file", 2929 }, 2930 { 2931 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2932 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, 2933 .name = "compression type", 2934 }, 2935 { 2936 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 2937 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 2938 .name = "lazy refcounts", 2939 }, 2940 { 2941 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 2942 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, 2943 .name = "bitmaps", 2944 }, 2945 { 2946 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 2947 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 2948 .name = "raw external data", 2949 }, 2950 }; 2951 2952 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 2953 features, sizeof(features), buflen); 2954 if (ret < 0) { 2955 goto fail; 2956 } 2957 buf += ret; 2958 buflen -= ret; 2959 } 2960 2961 /* Bitmap extension */ 2962 if (s->nb_bitmaps > 0) { 2963 Qcow2BitmapHeaderExt bitmaps_header = { 2964 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 2965 .bitmap_directory_size = 2966 cpu_to_be64(s->bitmap_directory_size), 2967 .bitmap_directory_offset = 2968 cpu_to_be64(s->bitmap_directory_offset) 2969 }; 2970 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 2971 &bitmaps_header, sizeof(bitmaps_header), 2972 buflen); 2973 if (ret < 0) { 2974 goto fail; 2975 } 2976 buf += ret; 2977 buflen -= ret; 2978 } 2979 2980 /* Keep unknown header extensions */ 2981 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 2982 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 2983 if (ret < 0) { 2984 goto fail; 2985 } 2986 2987 buf += ret; 2988 buflen -= ret; 2989 } 2990 2991 /* End of header extensions */ 2992 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 2993 if (ret < 0) { 2994 goto fail; 2995 } 2996 2997 buf += ret; 2998 buflen -= ret; 2999 3000 /* Backing file name */ 3001 if (s->image_backing_file) { 3002 size_t backing_file_len = strlen(s->image_backing_file); 3003 3004 if (buflen < backing_file_len) { 3005 ret = -ENOSPC; 3006 goto fail; 3007 } 3008 3009 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 3010 strncpy(buf, s->image_backing_file, buflen); 3011 3012 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 3013 header->backing_file_size = cpu_to_be32(backing_file_len); 3014 } 3015 3016 /* Write the new header */ 3017 ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size); 3018 if (ret < 0) { 3019 goto fail; 3020 } 3021 3022 ret = 0; 3023 fail: 3024 qemu_vfree(header); 3025 return ret; 3026 } 3027 3028 static int qcow2_change_backing_file(BlockDriverState *bs, 3029 const char *backing_file, const char *backing_fmt) 3030 { 3031 BDRVQcow2State *s = bs->opaque; 3032 3033 /* Adding a backing file means that the external data file alone won't be 3034 * enough to make sense of the content */ 3035 if (backing_file && data_file_is_raw(bs)) { 3036 return -EINVAL; 3037 } 3038 3039 if (backing_file && strlen(backing_file) > 1023) { 3040 return -EINVAL; 3041 } 3042 3043 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 3044 backing_file ?: ""); 3045 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 3046 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 3047 3048 g_free(s->image_backing_file); 3049 g_free(s->image_backing_format); 3050 3051 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 3052 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 3053 3054 return qcow2_update_header(bs); 3055 } 3056 3057 static int qcow2_set_up_encryption(BlockDriverState *bs, 3058 QCryptoBlockCreateOptions *cryptoopts, 3059 Error **errp) 3060 { 3061 BDRVQcow2State *s = bs->opaque; 3062 QCryptoBlock *crypto = NULL; 3063 int fmt, ret; 3064 3065 switch (cryptoopts->format) { 3066 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 3067 fmt = QCOW_CRYPT_LUKS; 3068 break; 3069 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 3070 fmt = QCOW_CRYPT_AES; 3071 break; 3072 default: 3073 error_setg(errp, "Crypto format not supported in qcow2"); 3074 return -EINVAL; 3075 } 3076 3077 s->crypt_method_header = fmt; 3078 3079 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 3080 qcow2_crypto_hdr_init_func, 3081 qcow2_crypto_hdr_write_func, 3082 bs, errp); 3083 if (!crypto) { 3084 return -EINVAL; 3085 } 3086 3087 ret = qcow2_update_header(bs); 3088 if (ret < 0) { 3089 error_setg_errno(errp, -ret, "Could not write encryption header"); 3090 goto out; 3091 } 3092 3093 ret = 0; 3094 out: 3095 qcrypto_block_free(crypto); 3096 return ret; 3097 } 3098 3099 /** 3100 * Preallocates metadata structures for data clusters between @offset (in the 3101 * guest disk) and @new_length (which is thus generally the new guest disk 3102 * size). 3103 * 3104 * Returns: 0 on success, -errno on failure. 3105 */ 3106 static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset, 3107 uint64_t new_length, PreallocMode mode, 3108 Error **errp) 3109 { 3110 BDRVQcow2State *s = bs->opaque; 3111 uint64_t bytes; 3112 uint64_t host_offset = 0; 3113 int64_t file_length; 3114 unsigned int cur_bytes; 3115 int ret; 3116 QCowL2Meta *meta; 3117 3118 assert(offset <= new_length); 3119 bytes = new_length - offset; 3120 3121 while (bytes) { 3122 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); 3123 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 3124 &host_offset, &meta); 3125 if (ret < 0) { 3126 error_setg_errno(errp, -ret, "Allocating clusters failed"); 3127 return ret; 3128 } 3129 3130 while (meta) { 3131 QCowL2Meta *next = meta->next; 3132 3133 ret = qcow2_alloc_cluster_link_l2(bs, meta); 3134 if (ret < 0) { 3135 error_setg_errno(errp, -ret, "Mapping clusters failed"); 3136 qcow2_free_any_clusters(bs, meta->alloc_offset, 3137 meta->nb_clusters, QCOW2_DISCARD_NEVER); 3138 return ret; 3139 } 3140 3141 /* There are no dependent requests, but we need to remove our 3142 * request from the list of in-flight requests */ 3143 QLIST_REMOVE(meta, next_in_flight); 3144 3145 g_free(meta); 3146 meta = next; 3147 } 3148 3149 /* TODO Preallocate data if requested */ 3150 3151 bytes -= cur_bytes; 3152 offset += cur_bytes; 3153 } 3154 3155 /* 3156 * It is expected that the image file is large enough to actually contain 3157 * all of the allocated clusters (otherwise we get failing reads after 3158 * EOF). Extend the image to the last allocated sector. 3159 */ 3160 file_length = bdrv_getlength(s->data_file->bs); 3161 if (file_length < 0) { 3162 error_setg_errno(errp, -file_length, "Could not get file size"); 3163 return file_length; 3164 } 3165 3166 if (host_offset + cur_bytes > file_length) { 3167 if (mode == PREALLOC_MODE_METADATA) { 3168 mode = PREALLOC_MODE_OFF; 3169 } 3170 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false, 3171 mode, 0, errp); 3172 if (ret < 0) { 3173 return ret; 3174 } 3175 } 3176 3177 return 0; 3178 } 3179 3180 /* qcow2_refcount_metadata_size: 3181 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 3182 * @cluster_size: size of a cluster, in bytes 3183 * @refcount_order: refcount bits power-of-2 exponent 3184 * @generous_increase: allow for the refcount table to be 1.5x as large as it 3185 * needs to be 3186 * 3187 * Returns: Number of bytes required for refcount blocks and table metadata. 3188 */ 3189 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 3190 int refcount_order, bool generous_increase, 3191 uint64_t *refblock_count) 3192 { 3193 /* 3194 * Every host cluster is reference-counted, including metadata (even 3195 * refcount metadata is recursively included). 3196 * 3197 * An accurate formula for the size of refcount metadata size is difficult 3198 * to derive. An easier method of calculation is finding the fixed point 3199 * where no further refcount blocks or table clusters are required to 3200 * reference count every cluster. 3201 */ 3202 int64_t blocks_per_table_cluster = cluster_size / sizeof(uint64_t); 3203 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 3204 int64_t table = 0; /* number of refcount table clusters */ 3205 int64_t blocks = 0; /* number of refcount block clusters */ 3206 int64_t last; 3207 int64_t n = 0; 3208 3209 do { 3210 last = n; 3211 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 3212 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 3213 n = clusters + blocks + table; 3214 3215 if (n == last && generous_increase) { 3216 clusters += DIV_ROUND_UP(table, 2); 3217 n = 0; /* force another loop */ 3218 generous_increase = false; 3219 } 3220 } while (n != last); 3221 3222 if (refblock_count) { 3223 *refblock_count = blocks; 3224 } 3225 3226 return (blocks + table) * cluster_size; 3227 } 3228 3229 /** 3230 * qcow2_calc_prealloc_size: 3231 * @total_size: virtual disk size in bytes 3232 * @cluster_size: cluster size in bytes 3233 * @refcount_order: refcount bits power-of-2 exponent 3234 * 3235 * Returns: Total number of bytes required for the fully allocated image 3236 * (including metadata). 3237 */ 3238 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 3239 size_t cluster_size, 3240 int refcount_order) 3241 { 3242 int64_t meta_size = 0; 3243 uint64_t nl1e, nl2e; 3244 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 3245 3246 /* header: 1 cluster */ 3247 meta_size += cluster_size; 3248 3249 /* total size of L2 tables */ 3250 nl2e = aligned_total_size / cluster_size; 3251 nl2e = ROUND_UP(nl2e, cluster_size / sizeof(uint64_t)); 3252 meta_size += nl2e * sizeof(uint64_t); 3253 3254 /* total size of L1 tables */ 3255 nl1e = nl2e * sizeof(uint64_t) / cluster_size; 3256 nl1e = ROUND_UP(nl1e, cluster_size / sizeof(uint64_t)); 3257 meta_size += nl1e * sizeof(uint64_t); 3258 3259 /* total size of refcount table and blocks */ 3260 meta_size += qcow2_refcount_metadata_size( 3261 (meta_size + aligned_total_size) / cluster_size, 3262 cluster_size, refcount_order, false, NULL); 3263 3264 return meta_size + aligned_total_size; 3265 } 3266 3267 static bool validate_cluster_size(size_t cluster_size, Error **errp) 3268 { 3269 int cluster_bits = ctz32(cluster_size); 3270 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 3271 (1 << cluster_bits) != cluster_size) 3272 { 3273 error_setg(errp, "Cluster size must be a power of two between %d and " 3274 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 3275 return false; 3276 } 3277 return true; 3278 } 3279 3280 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, Error **errp) 3281 { 3282 size_t cluster_size; 3283 3284 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 3285 DEFAULT_CLUSTER_SIZE); 3286 if (!validate_cluster_size(cluster_size, errp)) { 3287 return 0; 3288 } 3289 return cluster_size; 3290 } 3291 3292 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 3293 { 3294 char *buf; 3295 int ret; 3296 3297 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 3298 if (!buf) { 3299 ret = 3; /* default */ 3300 } else if (!strcmp(buf, "0.10")) { 3301 ret = 2; 3302 } else if (!strcmp(buf, "1.1")) { 3303 ret = 3; 3304 } else { 3305 error_setg(errp, "Invalid compatibility level: '%s'", buf); 3306 ret = -EINVAL; 3307 } 3308 g_free(buf); 3309 return ret; 3310 } 3311 3312 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 3313 Error **errp) 3314 { 3315 uint64_t refcount_bits; 3316 3317 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 3318 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 3319 error_setg(errp, "Refcount width must be a power of two and may not " 3320 "exceed 64 bits"); 3321 return 0; 3322 } 3323 3324 if (version < 3 && refcount_bits != 16) { 3325 error_setg(errp, "Different refcount widths than 16 bits require " 3326 "compatibility level 1.1 or above (use compat=1.1 or " 3327 "greater)"); 3328 return 0; 3329 } 3330 3331 return refcount_bits; 3332 } 3333 3334 static int coroutine_fn 3335 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 3336 { 3337 BlockdevCreateOptionsQcow2 *qcow2_opts; 3338 QDict *options; 3339 3340 /* 3341 * Open the image file and write a minimal qcow2 header. 3342 * 3343 * We keep things simple and start with a zero-sized image. We also 3344 * do without refcount blocks or a L1 table for now. We'll fix the 3345 * inconsistency later. 3346 * 3347 * We do need a refcount table because growing the refcount table means 3348 * allocating two new refcount blocks - the second of which would be at 3349 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 3350 * size for any qcow2 image. 3351 */ 3352 BlockBackend *blk = NULL; 3353 BlockDriverState *bs = NULL; 3354 BlockDriverState *data_bs = NULL; 3355 QCowHeader *header; 3356 size_t cluster_size; 3357 int version; 3358 int refcount_order; 3359 uint64_t* refcount_table; 3360 Error *local_err = NULL; 3361 int ret; 3362 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 3363 3364 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 3365 qcow2_opts = &create_options->u.qcow2; 3366 3367 bs = bdrv_open_blockdev_ref(qcow2_opts->file, errp); 3368 if (bs == NULL) { 3369 return -EIO; 3370 } 3371 3372 /* Validate options and set default values */ 3373 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 3374 error_setg(errp, "Image size must be a multiple of %u bytes", 3375 (unsigned) BDRV_SECTOR_SIZE); 3376 ret = -EINVAL; 3377 goto out; 3378 } 3379 3380 if (qcow2_opts->has_version) { 3381 switch (qcow2_opts->version) { 3382 case BLOCKDEV_QCOW2_VERSION_V2: 3383 version = 2; 3384 break; 3385 case BLOCKDEV_QCOW2_VERSION_V3: 3386 version = 3; 3387 break; 3388 default: 3389 g_assert_not_reached(); 3390 } 3391 } else { 3392 version = 3; 3393 } 3394 3395 if (qcow2_opts->has_cluster_size) { 3396 cluster_size = qcow2_opts->cluster_size; 3397 } else { 3398 cluster_size = DEFAULT_CLUSTER_SIZE; 3399 } 3400 3401 if (!validate_cluster_size(cluster_size, errp)) { 3402 ret = -EINVAL; 3403 goto out; 3404 } 3405 3406 if (!qcow2_opts->has_preallocation) { 3407 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3408 } 3409 if (qcow2_opts->has_backing_file && 3410 qcow2_opts->preallocation != PREALLOC_MODE_OFF) 3411 { 3412 error_setg(errp, "Backing file and preallocation cannot be used at " 3413 "the same time"); 3414 ret = -EINVAL; 3415 goto out; 3416 } 3417 if (qcow2_opts->has_backing_fmt && !qcow2_opts->has_backing_file) { 3418 error_setg(errp, "Backing format cannot be used without backing file"); 3419 ret = -EINVAL; 3420 goto out; 3421 } 3422 3423 if (!qcow2_opts->has_lazy_refcounts) { 3424 qcow2_opts->lazy_refcounts = false; 3425 } 3426 if (version < 3 && qcow2_opts->lazy_refcounts) { 3427 error_setg(errp, "Lazy refcounts only supported with compatibility " 3428 "level 1.1 and above (use version=v3 or greater)"); 3429 ret = -EINVAL; 3430 goto out; 3431 } 3432 3433 if (!qcow2_opts->has_refcount_bits) { 3434 qcow2_opts->refcount_bits = 16; 3435 } 3436 if (qcow2_opts->refcount_bits > 64 || 3437 !is_power_of_2(qcow2_opts->refcount_bits)) 3438 { 3439 error_setg(errp, "Refcount width must be a power of two and may not " 3440 "exceed 64 bits"); 3441 ret = -EINVAL; 3442 goto out; 3443 } 3444 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3445 error_setg(errp, "Different refcount widths than 16 bits require " 3446 "compatibility level 1.1 or above (use version=v3 or " 3447 "greater)"); 3448 ret = -EINVAL; 3449 goto out; 3450 } 3451 refcount_order = ctz32(qcow2_opts->refcount_bits); 3452 3453 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3454 error_setg(errp, "data-file-raw requires data-file"); 3455 ret = -EINVAL; 3456 goto out; 3457 } 3458 if (qcow2_opts->data_file_raw && qcow2_opts->has_backing_file) { 3459 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3460 "the same time"); 3461 ret = -EINVAL; 3462 goto out; 3463 } 3464 3465 if (qcow2_opts->data_file) { 3466 if (version < 3) { 3467 error_setg(errp, "External data files are only supported with " 3468 "compatibility level 1.1 and above (use version=v3 or " 3469 "greater)"); 3470 ret = -EINVAL; 3471 goto out; 3472 } 3473 data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp); 3474 if (data_bs == NULL) { 3475 ret = -EIO; 3476 goto out; 3477 } 3478 } 3479 3480 if (qcow2_opts->has_compression_type && 3481 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3482 3483 ret = -EINVAL; 3484 3485 if (version < 3) { 3486 error_setg(errp, "Non-zlib compression type is only supported with " 3487 "compatibility level 1.1 and above (use version=v3 or " 3488 "greater)"); 3489 goto out; 3490 } 3491 3492 switch (qcow2_opts->compression_type) { 3493 #ifdef CONFIG_ZSTD 3494 case QCOW2_COMPRESSION_TYPE_ZSTD: 3495 break; 3496 #endif 3497 default: 3498 error_setg(errp, "Unknown compression type"); 3499 goto out; 3500 } 3501 3502 compression_type = qcow2_opts->compression_type; 3503 } 3504 3505 /* Create BlockBackend to write to the image */ 3506 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 3507 errp); 3508 if (!blk) { 3509 ret = -EPERM; 3510 goto out; 3511 } 3512 blk_set_allow_write_beyond_eof(blk, true); 3513 3514 /* Write the header */ 3515 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3516 header = g_malloc0(cluster_size); 3517 *header = (QCowHeader) { 3518 .magic = cpu_to_be32(QCOW_MAGIC), 3519 .version = cpu_to_be32(version), 3520 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3521 .size = cpu_to_be64(0), 3522 .l1_table_offset = cpu_to_be64(0), 3523 .l1_size = cpu_to_be32(0), 3524 .refcount_table_offset = cpu_to_be64(cluster_size), 3525 .refcount_table_clusters = cpu_to_be32(1), 3526 .refcount_order = cpu_to_be32(refcount_order), 3527 /* don't deal with endianness since compression_type is 1 byte long */ 3528 .compression_type = compression_type, 3529 .header_length = cpu_to_be32(sizeof(*header)), 3530 }; 3531 3532 /* We'll update this to correct value later */ 3533 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3534 3535 if (qcow2_opts->lazy_refcounts) { 3536 header->compatible_features |= 3537 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3538 } 3539 if (data_bs) { 3540 header->incompatible_features |= 3541 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3542 } 3543 if (qcow2_opts->data_file_raw) { 3544 header->autoclear_features |= 3545 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3546 } 3547 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3548 header->incompatible_features |= 3549 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); 3550 } 3551 3552 ret = blk_pwrite(blk, 0, header, cluster_size, 0); 3553 g_free(header); 3554 if (ret < 0) { 3555 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3556 goto out; 3557 } 3558 3559 /* Write a refcount table with one refcount block */ 3560 refcount_table = g_malloc0(2 * cluster_size); 3561 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3562 ret = blk_pwrite(blk, cluster_size, refcount_table, 2 * cluster_size, 0); 3563 g_free(refcount_table); 3564 3565 if (ret < 0) { 3566 error_setg_errno(errp, -ret, "Could not write refcount table"); 3567 goto out; 3568 } 3569 3570 blk_unref(blk); 3571 blk = NULL; 3572 3573 /* 3574 * And now open the image and make it consistent first (i.e. increase the 3575 * refcount of the cluster that is occupied by the header and the refcount 3576 * table) 3577 */ 3578 options = qdict_new(); 3579 qdict_put_str(options, "driver", "qcow2"); 3580 qdict_put_str(options, "file", bs->node_name); 3581 if (data_bs) { 3582 qdict_put_str(options, "data-file", data_bs->node_name); 3583 } 3584 blk = blk_new_open(NULL, NULL, options, 3585 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3586 &local_err); 3587 if (blk == NULL) { 3588 error_propagate(errp, local_err); 3589 ret = -EIO; 3590 goto out; 3591 } 3592 3593 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3594 if (ret < 0) { 3595 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3596 "header and refcount table"); 3597 goto out; 3598 3599 } else if (ret != 0) { 3600 error_report("Huh, first cluster in empty image is already in use?"); 3601 abort(); 3602 } 3603 3604 /* Set the external data file if necessary */ 3605 if (data_bs) { 3606 BDRVQcow2State *s = blk_bs(blk)->opaque; 3607 s->image_data_file = g_strdup(data_bs->filename); 3608 } 3609 3610 /* Create a full header (including things like feature table) */ 3611 ret = qcow2_update_header(blk_bs(blk)); 3612 if (ret < 0) { 3613 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3614 goto out; 3615 } 3616 3617 /* Okay, now that we have a valid image, let's give it the right size */ 3618 ret = blk_truncate(blk, qcow2_opts->size, false, qcow2_opts->preallocation, 3619 0, errp); 3620 if (ret < 0) { 3621 error_prepend(errp, "Could not resize image: "); 3622 goto out; 3623 } 3624 3625 /* Want a backing file? There you go. */ 3626 if (qcow2_opts->has_backing_file) { 3627 const char *backing_format = NULL; 3628 3629 if (qcow2_opts->has_backing_fmt) { 3630 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3631 } 3632 3633 ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3634 backing_format); 3635 if (ret < 0) { 3636 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3637 "with format '%s'", qcow2_opts->backing_file, 3638 backing_format); 3639 goto out; 3640 } 3641 } 3642 3643 /* Want encryption? There you go. */ 3644 if (qcow2_opts->has_encrypt) { 3645 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3646 if (ret < 0) { 3647 goto out; 3648 } 3649 } 3650 3651 blk_unref(blk); 3652 blk = NULL; 3653 3654 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3655 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3656 * have to setup decryption context. We're not doing any I/O on the top 3657 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3658 * not have effect. 3659 */ 3660 options = qdict_new(); 3661 qdict_put_str(options, "driver", "qcow2"); 3662 qdict_put_str(options, "file", bs->node_name); 3663 if (data_bs) { 3664 qdict_put_str(options, "data-file", data_bs->node_name); 3665 } 3666 blk = blk_new_open(NULL, NULL, options, 3667 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3668 &local_err); 3669 if (blk == NULL) { 3670 error_propagate(errp, local_err); 3671 ret = -EIO; 3672 goto out; 3673 } 3674 3675 ret = 0; 3676 out: 3677 blk_unref(blk); 3678 bdrv_unref(bs); 3679 bdrv_unref(data_bs); 3680 return ret; 3681 } 3682 3683 static int coroutine_fn qcow2_co_create_opts(BlockDriver *drv, 3684 const char *filename, 3685 QemuOpts *opts, 3686 Error **errp) 3687 { 3688 BlockdevCreateOptions *create_options = NULL; 3689 QDict *qdict; 3690 Visitor *v; 3691 BlockDriverState *bs = NULL; 3692 BlockDriverState *data_bs = NULL; 3693 Error *local_err = NULL; 3694 const char *val; 3695 int ret; 3696 3697 /* Only the keyval visitor supports the dotted syntax needed for 3698 * encryption, so go through a QDict before getting a QAPI type. Ignore 3699 * options meant for the protocol layer so that the visitor doesn't 3700 * complain. */ 3701 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3702 true); 3703 3704 /* Handle encryption options */ 3705 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3706 if (val && !strcmp(val, "on")) { 3707 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3708 } else if (val && !strcmp(val, "off")) { 3709 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3710 } 3711 3712 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3713 if (val && !strcmp(val, "aes")) { 3714 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3715 } 3716 3717 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3718 * version=v2/v3 below. */ 3719 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3720 if (val && !strcmp(val, "0.10")) { 3721 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3722 } else if (val && !strcmp(val, "1.1")) { 3723 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3724 } 3725 3726 /* Change legacy command line options into QMP ones */ 3727 static const QDictRenames opt_renames[] = { 3728 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3729 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3730 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3731 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3732 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3733 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3734 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3735 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3736 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, 3737 { NULL, NULL }, 3738 }; 3739 3740 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3741 ret = -EINVAL; 3742 goto finish; 3743 } 3744 3745 /* Create and open the file (protocol layer) */ 3746 ret = bdrv_create_file(filename, opts, errp); 3747 if (ret < 0) { 3748 goto finish; 3749 } 3750 3751 bs = bdrv_open(filename, NULL, NULL, 3752 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3753 if (bs == NULL) { 3754 ret = -EIO; 3755 goto finish; 3756 } 3757 3758 /* Create and open an external data file (protocol layer) */ 3759 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3760 if (val) { 3761 ret = bdrv_create_file(val, opts, errp); 3762 if (ret < 0) { 3763 goto finish; 3764 } 3765 3766 data_bs = bdrv_open(val, NULL, NULL, 3767 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3768 errp); 3769 if (data_bs == NULL) { 3770 ret = -EIO; 3771 goto finish; 3772 } 3773 3774 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3775 qdict_put_str(qdict, "data-file", data_bs->node_name); 3776 } 3777 3778 /* Set 'driver' and 'node' options */ 3779 qdict_put_str(qdict, "driver", "qcow2"); 3780 qdict_put_str(qdict, "file", bs->node_name); 3781 3782 /* Now get the QAPI type BlockdevCreateOptions */ 3783 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3784 if (!v) { 3785 ret = -EINVAL; 3786 goto finish; 3787 } 3788 3789 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 3790 visit_free(v); 3791 3792 if (local_err) { 3793 error_propagate(errp, local_err); 3794 ret = -EINVAL; 3795 goto finish; 3796 } 3797 3798 /* Silently round up size */ 3799 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 3800 BDRV_SECTOR_SIZE); 3801 3802 /* Create the qcow2 image (format layer) */ 3803 ret = qcow2_co_create(create_options, errp); 3804 if (ret < 0) { 3805 goto finish; 3806 } 3807 3808 ret = 0; 3809 finish: 3810 qobject_unref(qdict); 3811 bdrv_unref(bs); 3812 bdrv_unref(data_bs); 3813 qapi_free_BlockdevCreateOptions(create_options); 3814 return ret; 3815 } 3816 3817 3818 static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 3819 { 3820 int64_t nr; 3821 int res; 3822 3823 /* Clamp to image length, before checking status of underlying sectors */ 3824 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 3825 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 3826 } 3827 3828 if (!bytes) { 3829 return true; 3830 } 3831 res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 3832 return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; 3833 } 3834 3835 static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, 3836 int64_t offset, int bytes, BdrvRequestFlags flags) 3837 { 3838 int ret; 3839 BDRVQcow2State *s = bs->opaque; 3840 3841 uint32_t head = offset % s->cluster_size; 3842 uint32_t tail = (offset + bytes) % s->cluster_size; 3843 3844 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 3845 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 3846 tail = 0; 3847 } 3848 3849 if (head || tail) { 3850 uint64_t off; 3851 unsigned int nr; 3852 3853 assert(head + bytes <= s->cluster_size); 3854 3855 /* check whether remainder of cluster already reads as zero */ 3856 if (!(is_zero(bs, offset - head, head) && 3857 is_zero(bs, offset + bytes, 3858 tail ? s->cluster_size - tail : 0))) { 3859 return -ENOTSUP; 3860 } 3861 3862 qemu_co_mutex_lock(&s->lock); 3863 /* We can have new write after previous check */ 3864 offset = QEMU_ALIGN_DOWN(offset, s->cluster_size); 3865 bytes = s->cluster_size; 3866 nr = s->cluster_size; 3867 ret = qcow2_get_cluster_offset(bs, offset, &nr, &off); 3868 if (ret != QCOW2_CLUSTER_UNALLOCATED && 3869 ret != QCOW2_CLUSTER_ZERO_PLAIN && 3870 ret != QCOW2_CLUSTER_ZERO_ALLOC) { 3871 qemu_co_mutex_unlock(&s->lock); 3872 return -ENOTSUP; 3873 } 3874 } else { 3875 qemu_co_mutex_lock(&s->lock); 3876 } 3877 3878 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 3879 3880 /* Whatever is left can use real zero clusters */ 3881 ret = qcow2_cluster_zeroize(bs, offset, bytes, flags); 3882 qemu_co_mutex_unlock(&s->lock); 3883 3884 return ret; 3885 } 3886 3887 static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs, 3888 int64_t offset, int bytes) 3889 { 3890 int ret; 3891 BDRVQcow2State *s = bs->opaque; 3892 3893 /* If the image does not support QCOW_OFLAG_ZERO then discarding 3894 * clusters could expose stale data from the backing file. */ 3895 if (s->qcow_version < 3 && bs->backing) { 3896 return -ENOTSUP; 3897 } 3898 3899 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 3900 assert(bytes < s->cluster_size); 3901 /* Ignore partial clusters, except for the special case of the 3902 * complete partial cluster at the end of an unaligned file */ 3903 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 3904 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 3905 return -ENOTSUP; 3906 } 3907 } 3908 3909 qemu_co_mutex_lock(&s->lock); 3910 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 3911 false); 3912 qemu_co_mutex_unlock(&s->lock); 3913 return ret; 3914 } 3915 3916 static int coroutine_fn 3917 qcow2_co_copy_range_from(BlockDriverState *bs, 3918 BdrvChild *src, uint64_t src_offset, 3919 BdrvChild *dst, uint64_t dst_offset, 3920 uint64_t bytes, BdrvRequestFlags read_flags, 3921 BdrvRequestFlags write_flags) 3922 { 3923 BDRVQcow2State *s = bs->opaque; 3924 int ret; 3925 unsigned int cur_bytes; /* number of bytes in current iteration */ 3926 BdrvChild *child = NULL; 3927 BdrvRequestFlags cur_write_flags; 3928 3929 assert(!bs->encrypted); 3930 qemu_co_mutex_lock(&s->lock); 3931 3932 while (bytes != 0) { 3933 uint64_t copy_offset = 0; 3934 /* prepare next request */ 3935 cur_bytes = MIN(bytes, INT_MAX); 3936 cur_write_flags = write_flags; 3937 3938 ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, ©_offset); 3939 if (ret < 0) { 3940 goto out; 3941 } 3942 3943 switch (ret) { 3944 case QCOW2_CLUSTER_UNALLOCATED: 3945 if (bs->backing && bs->backing->bs) { 3946 int64_t backing_length = bdrv_getlength(bs->backing->bs); 3947 if (src_offset >= backing_length) { 3948 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3949 } else { 3950 child = bs->backing; 3951 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 3952 copy_offset = src_offset; 3953 } 3954 } else { 3955 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3956 } 3957 break; 3958 3959 case QCOW2_CLUSTER_ZERO_PLAIN: 3960 case QCOW2_CLUSTER_ZERO_ALLOC: 3961 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3962 break; 3963 3964 case QCOW2_CLUSTER_COMPRESSED: 3965 ret = -ENOTSUP; 3966 goto out; 3967 3968 case QCOW2_CLUSTER_NORMAL: 3969 child = s->data_file; 3970 copy_offset += offset_into_cluster(s, src_offset); 3971 break; 3972 3973 default: 3974 abort(); 3975 } 3976 qemu_co_mutex_unlock(&s->lock); 3977 ret = bdrv_co_copy_range_from(child, 3978 copy_offset, 3979 dst, dst_offset, 3980 cur_bytes, read_flags, cur_write_flags); 3981 qemu_co_mutex_lock(&s->lock); 3982 if (ret < 0) { 3983 goto out; 3984 } 3985 3986 bytes -= cur_bytes; 3987 src_offset += cur_bytes; 3988 dst_offset += cur_bytes; 3989 } 3990 ret = 0; 3991 3992 out: 3993 qemu_co_mutex_unlock(&s->lock); 3994 return ret; 3995 } 3996 3997 static int coroutine_fn 3998 qcow2_co_copy_range_to(BlockDriverState *bs, 3999 BdrvChild *src, uint64_t src_offset, 4000 BdrvChild *dst, uint64_t dst_offset, 4001 uint64_t bytes, BdrvRequestFlags read_flags, 4002 BdrvRequestFlags write_flags) 4003 { 4004 BDRVQcow2State *s = bs->opaque; 4005 int offset_in_cluster; 4006 int ret; 4007 unsigned int cur_bytes; /* number of sectors in current iteration */ 4008 uint64_t cluster_offset; 4009 QCowL2Meta *l2meta = NULL; 4010 4011 assert(!bs->encrypted); 4012 4013 qemu_co_mutex_lock(&s->lock); 4014 4015 while (bytes != 0) { 4016 4017 l2meta = NULL; 4018 4019 offset_in_cluster = offset_into_cluster(s, dst_offset); 4020 cur_bytes = MIN(bytes, INT_MAX); 4021 4022 /* TODO: 4023 * If src->bs == dst->bs, we could simply copy by incrementing 4024 * the refcnt, without copying user data. 4025 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 4026 ret = qcow2_alloc_cluster_offset(bs, dst_offset, &cur_bytes, 4027 &cluster_offset, &l2meta); 4028 if (ret < 0) { 4029 goto fail; 4030 } 4031 4032 assert(offset_into_cluster(s, cluster_offset) == 0); 4033 4034 ret = qcow2_pre_write_overlap_check(bs, 0, 4035 cluster_offset + offset_in_cluster, cur_bytes, true); 4036 if (ret < 0) { 4037 goto fail; 4038 } 4039 4040 qemu_co_mutex_unlock(&s->lock); 4041 ret = bdrv_co_copy_range_to(src, src_offset, 4042 s->data_file, 4043 cluster_offset + offset_in_cluster, 4044 cur_bytes, read_flags, write_flags); 4045 qemu_co_mutex_lock(&s->lock); 4046 if (ret < 0) { 4047 goto fail; 4048 } 4049 4050 ret = qcow2_handle_l2meta(bs, &l2meta, true); 4051 if (ret) { 4052 goto fail; 4053 } 4054 4055 bytes -= cur_bytes; 4056 src_offset += cur_bytes; 4057 dst_offset += cur_bytes; 4058 } 4059 ret = 0; 4060 4061 fail: 4062 qcow2_handle_l2meta(bs, &l2meta, false); 4063 4064 qemu_co_mutex_unlock(&s->lock); 4065 4066 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 4067 4068 return ret; 4069 } 4070 4071 static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, 4072 bool exact, PreallocMode prealloc, 4073 BdrvRequestFlags flags, Error **errp) 4074 { 4075 BDRVQcow2State *s = bs->opaque; 4076 uint64_t old_length; 4077 int64_t new_l1_size; 4078 int ret; 4079 QDict *options; 4080 4081 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 4082 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 4083 { 4084 error_setg(errp, "Unsupported preallocation mode '%s'", 4085 PreallocMode_str(prealloc)); 4086 return -ENOTSUP; 4087 } 4088 4089 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) { 4090 error_setg(errp, "The new size must be a multiple of %u", 4091 (unsigned) BDRV_SECTOR_SIZE); 4092 return -EINVAL; 4093 } 4094 4095 qemu_co_mutex_lock(&s->lock); 4096 4097 /* 4098 * Even though we store snapshot size for all images, it was not 4099 * required until v3, so it is not safe to proceed for v2. 4100 */ 4101 if (s->nb_snapshots && s->qcow_version < 3) { 4102 error_setg(errp, "Can't resize a v2 image which has snapshots"); 4103 ret = -ENOTSUP; 4104 goto fail; 4105 } 4106 4107 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */ 4108 if (qcow2_truncate_bitmaps_check(bs, errp)) { 4109 ret = -ENOTSUP; 4110 goto fail; 4111 } 4112 4113 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 4114 new_l1_size = size_to_l1(s, offset); 4115 4116 if (offset < old_length) { 4117 int64_t last_cluster, old_file_size; 4118 if (prealloc != PREALLOC_MODE_OFF) { 4119 error_setg(errp, 4120 "Preallocation can't be used for shrinking an image"); 4121 ret = -EINVAL; 4122 goto fail; 4123 } 4124 4125 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 4126 old_length - ROUND_UP(offset, 4127 s->cluster_size), 4128 QCOW2_DISCARD_ALWAYS, true); 4129 if (ret < 0) { 4130 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 4131 goto fail; 4132 } 4133 4134 ret = qcow2_shrink_l1_table(bs, new_l1_size); 4135 if (ret < 0) { 4136 error_setg_errno(errp, -ret, 4137 "Failed to reduce the number of L2 tables"); 4138 goto fail; 4139 } 4140 4141 ret = qcow2_shrink_reftable(bs); 4142 if (ret < 0) { 4143 error_setg_errno(errp, -ret, 4144 "Failed to discard unused refblocks"); 4145 goto fail; 4146 } 4147 4148 old_file_size = bdrv_getlength(bs->file->bs); 4149 if (old_file_size < 0) { 4150 error_setg_errno(errp, -old_file_size, 4151 "Failed to inquire current file length"); 4152 ret = old_file_size; 4153 goto fail; 4154 } 4155 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4156 if (last_cluster < 0) { 4157 error_setg_errno(errp, -last_cluster, 4158 "Failed to find the last cluster"); 4159 ret = last_cluster; 4160 goto fail; 4161 } 4162 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 4163 Error *local_err = NULL; 4164 4165 /* 4166 * Do not pass @exact here: It will not help the user if 4167 * we get an error here just because they wanted to shrink 4168 * their qcow2 image (on a block device) with qemu-img. 4169 * (And on the qcow2 layer, the @exact requirement is 4170 * always fulfilled, so there is no need to pass it on.) 4171 */ 4172 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 4173 false, PREALLOC_MODE_OFF, 0, &local_err); 4174 if (local_err) { 4175 warn_reportf_err(local_err, 4176 "Failed to truncate the tail of the image: "); 4177 } 4178 } 4179 } else { 4180 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 4181 if (ret < 0) { 4182 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 4183 goto fail; 4184 } 4185 } 4186 4187 switch (prealloc) { 4188 case PREALLOC_MODE_OFF: 4189 if (has_data_file(bs)) { 4190 /* 4191 * If the caller wants an exact resize, the external data 4192 * file should be resized to the exact target size, too, 4193 * so we pass @exact here. 4194 */ 4195 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0, 4196 errp); 4197 if (ret < 0) { 4198 goto fail; 4199 } 4200 } 4201 break; 4202 4203 case PREALLOC_MODE_METADATA: 4204 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4205 if (ret < 0) { 4206 goto fail; 4207 } 4208 break; 4209 4210 case PREALLOC_MODE_FALLOC: 4211 case PREALLOC_MODE_FULL: 4212 { 4213 int64_t allocation_start, host_offset, guest_offset; 4214 int64_t clusters_allocated; 4215 int64_t old_file_size, last_cluster, new_file_size; 4216 uint64_t nb_new_data_clusters, nb_new_l2_tables; 4217 4218 /* With a data file, preallocation means just allocating the metadata 4219 * and forwarding the truncate request to the data file */ 4220 if (has_data_file(bs)) { 4221 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4222 if (ret < 0) { 4223 goto fail; 4224 } 4225 break; 4226 } 4227 4228 old_file_size = bdrv_getlength(bs->file->bs); 4229 if (old_file_size < 0) { 4230 error_setg_errno(errp, -old_file_size, 4231 "Failed to inquire current file length"); 4232 ret = old_file_size; 4233 goto fail; 4234 } 4235 4236 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4237 if (last_cluster >= 0) { 4238 old_file_size = (last_cluster + 1) * s->cluster_size; 4239 } else { 4240 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 4241 } 4242 4243 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) - 4244 start_of_cluster(s, old_length)) >> s->cluster_bits; 4245 4246 /* This is an overestimation; we will not actually allocate space for 4247 * these in the file but just make sure the new refcount structures are 4248 * able to cover them so we will not have to allocate new refblocks 4249 * while entering the data blocks in the potentially new L2 tables. 4250 * (We do not actually care where the L2 tables are placed. Maybe they 4251 * are already allocated or they can be placed somewhere before 4252 * @old_file_size. It does not matter because they will be fully 4253 * allocated automatically, so they do not need to be covered by the 4254 * preallocation. All that matters is that we will not have to allocate 4255 * new refcount structures for them.) */ 4256 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 4257 s->cluster_size / sizeof(uint64_t)); 4258 /* The cluster range may not be aligned to L2 boundaries, so add one L2 4259 * table for a potential head/tail */ 4260 nb_new_l2_tables++; 4261 4262 allocation_start = qcow2_refcount_area(bs, old_file_size, 4263 nb_new_data_clusters + 4264 nb_new_l2_tables, 4265 true, 0, 0); 4266 if (allocation_start < 0) { 4267 error_setg_errno(errp, -allocation_start, 4268 "Failed to resize refcount structures"); 4269 ret = allocation_start; 4270 goto fail; 4271 } 4272 4273 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 4274 nb_new_data_clusters); 4275 if (clusters_allocated < 0) { 4276 error_setg_errno(errp, -clusters_allocated, 4277 "Failed to allocate data clusters"); 4278 ret = clusters_allocated; 4279 goto fail; 4280 } 4281 4282 assert(clusters_allocated == nb_new_data_clusters); 4283 4284 /* Allocate the data area */ 4285 new_file_size = allocation_start + 4286 nb_new_data_clusters * s->cluster_size; 4287 /* 4288 * Image file grows, so @exact does not matter. 4289 * 4290 * If we need to zero out the new area, try first whether the protocol 4291 * driver can already take care of this. 4292 */ 4293 if (flags & BDRV_REQ_ZERO_WRITE) { 4294 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 4295 BDRV_REQ_ZERO_WRITE, NULL); 4296 if (ret >= 0) { 4297 flags &= ~BDRV_REQ_ZERO_WRITE; 4298 } 4299 } else { 4300 ret = -1; 4301 } 4302 if (ret < 0) { 4303 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0, 4304 errp); 4305 } 4306 if (ret < 0) { 4307 error_prepend(errp, "Failed to resize underlying file: "); 4308 qcow2_free_clusters(bs, allocation_start, 4309 nb_new_data_clusters * s->cluster_size, 4310 QCOW2_DISCARD_OTHER); 4311 goto fail; 4312 } 4313 4314 /* Create the necessary L2 entries */ 4315 host_offset = allocation_start; 4316 guest_offset = old_length; 4317 while (nb_new_data_clusters) { 4318 int64_t nb_clusters = MIN( 4319 nb_new_data_clusters, 4320 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 4321 unsigned cow_start_length = offset_into_cluster(s, guest_offset); 4322 QCowL2Meta allocation; 4323 guest_offset = start_of_cluster(s, guest_offset); 4324 allocation = (QCowL2Meta) { 4325 .offset = guest_offset, 4326 .alloc_offset = host_offset, 4327 .nb_clusters = nb_clusters, 4328 .cow_start = { 4329 .offset = 0, 4330 .nb_bytes = cow_start_length, 4331 }, 4332 .cow_end = { 4333 .offset = nb_clusters << s->cluster_bits, 4334 .nb_bytes = 0, 4335 }, 4336 }; 4337 qemu_co_queue_init(&allocation.dependent_requests); 4338 4339 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 4340 if (ret < 0) { 4341 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 4342 qcow2_free_clusters(bs, host_offset, 4343 nb_new_data_clusters * s->cluster_size, 4344 QCOW2_DISCARD_OTHER); 4345 goto fail; 4346 } 4347 4348 guest_offset += nb_clusters * s->cluster_size; 4349 host_offset += nb_clusters * s->cluster_size; 4350 nb_new_data_clusters -= nb_clusters; 4351 } 4352 break; 4353 } 4354 4355 default: 4356 g_assert_not_reached(); 4357 } 4358 4359 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { 4360 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->cluster_size); 4361 4362 /* 4363 * Use zero clusters as much as we can. qcow2_cluster_zeroize() 4364 * requires a cluster-aligned start. The end may be unaligned if it is 4365 * at the end of the image (which it is here). 4366 */ 4367 if (offset > zero_start) { 4368 ret = qcow2_cluster_zeroize(bs, zero_start, offset - zero_start, 0); 4369 if (ret < 0) { 4370 error_setg_errno(errp, -ret, "Failed to zero out new clusters"); 4371 goto fail; 4372 } 4373 } 4374 4375 /* Write explicit zeros for the unaligned head */ 4376 if (zero_start > old_length) { 4377 uint64_t len = MIN(zero_start, offset) - old_length; 4378 uint8_t *buf = qemu_blockalign0(bs, len); 4379 QEMUIOVector qiov; 4380 qemu_iovec_init_buf(&qiov, buf, len); 4381 4382 qemu_co_mutex_unlock(&s->lock); 4383 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0); 4384 qemu_co_mutex_lock(&s->lock); 4385 4386 qemu_vfree(buf); 4387 if (ret < 0) { 4388 error_setg_errno(errp, -ret, "Failed to zero out the new area"); 4389 goto fail; 4390 } 4391 } 4392 } 4393 4394 if (prealloc != PREALLOC_MODE_OFF) { 4395 /* Flush metadata before actually changing the image size */ 4396 ret = qcow2_write_caches(bs); 4397 if (ret < 0) { 4398 error_setg_errno(errp, -ret, 4399 "Failed to flush the preallocated area to disk"); 4400 goto fail; 4401 } 4402 } 4403 4404 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 4405 4406 /* write updated header.size */ 4407 offset = cpu_to_be64(offset); 4408 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), 4409 &offset, sizeof(uint64_t)); 4410 if (ret < 0) { 4411 error_setg_errno(errp, -ret, "Failed to update the image size"); 4412 goto fail; 4413 } 4414 4415 s->l1_vm_state_index = new_l1_size; 4416 4417 /* Update cache sizes */ 4418 options = qdict_clone_shallow(bs->options); 4419 ret = qcow2_update_options(bs, options, s->flags, errp); 4420 qobject_unref(options); 4421 if (ret < 0) { 4422 goto fail; 4423 } 4424 ret = 0; 4425 fail: 4426 qemu_co_mutex_unlock(&s->lock); 4427 return ret; 4428 } 4429 4430 static coroutine_fn int 4431 qcow2_co_pwritev_compressed_task(BlockDriverState *bs, 4432 uint64_t offset, uint64_t bytes, 4433 QEMUIOVector *qiov, size_t qiov_offset) 4434 { 4435 BDRVQcow2State *s = bs->opaque; 4436 int ret; 4437 ssize_t out_len; 4438 uint8_t *buf, *out_buf; 4439 uint64_t cluster_offset; 4440 4441 assert(bytes == s->cluster_size || (bytes < s->cluster_size && 4442 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))); 4443 4444 buf = qemu_blockalign(bs, s->cluster_size); 4445 if (bytes < s->cluster_size) { 4446 /* Zero-pad last write if image size is not cluster aligned */ 4447 memset(buf + bytes, 0, s->cluster_size - bytes); 4448 } 4449 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); 4450 4451 out_buf = g_malloc(s->cluster_size); 4452 4453 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4454 buf, s->cluster_size); 4455 if (out_len == -ENOMEM) { 4456 /* could not compress: write normal cluster */ 4457 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); 4458 if (ret < 0) { 4459 goto fail; 4460 } 4461 goto success; 4462 } else if (out_len < 0) { 4463 ret = -EINVAL; 4464 goto fail; 4465 } 4466 4467 qemu_co_mutex_lock(&s->lock); 4468 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4469 &cluster_offset); 4470 if (ret < 0) { 4471 qemu_co_mutex_unlock(&s->lock); 4472 goto fail; 4473 } 4474 4475 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4476 qemu_co_mutex_unlock(&s->lock); 4477 if (ret < 0) { 4478 goto fail; 4479 } 4480 4481 BLKDBG_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4482 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); 4483 if (ret < 0) { 4484 goto fail; 4485 } 4486 success: 4487 ret = 0; 4488 fail: 4489 qemu_vfree(buf); 4490 g_free(out_buf); 4491 return ret; 4492 } 4493 4494 static coroutine_fn int qcow2_co_pwritev_compressed_task_entry(AioTask *task) 4495 { 4496 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 4497 4498 assert(!t->cluster_type && !t->l2meta); 4499 4500 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov, 4501 t->qiov_offset); 4502 } 4503 4504 /* 4505 * XXX: put compressed sectors first, then all the cluster aligned 4506 * tables to avoid losing bytes in alignment 4507 */ 4508 static coroutine_fn int 4509 qcow2_co_pwritev_compressed_part(BlockDriverState *bs, 4510 uint64_t offset, uint64_t bytes, 4511 QEMUIOVector *qiov, size_t qiov_offset) 4512 { 4513 BDRVQcow2State *s = bs->opaque; 4514 AioTaskPool *aio = NULL; 4515 int ret = 0; 4516 4517 if (has_data_file(bs)) { 4518 return -ENOTSUP; 4519 } 4520 4521 if (bytes == 0) { 4522 /* 4523 * align end of file to a sector boundary to ease reading with 4524 * sector based I/Os 4525 */ 4526 int64_t len = bdrv_getlength(bs->file->bs); 4527 if (len < 0) { 4528 return len; 4529 } 4530 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0, 4531 NULL); 4532 } 4533 4534 if (offset_into_cluster(s, offset)) { 4535 return -EINVAL; 4536 } 4537 4538 if (offset_into_cluster(s, bytes) && 4539 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) { 4540 return -EINVAL; 4541 } 4542 4543 while (bytes && aio_task_pool_status(aio) == 0) { 4544 uint64_t chunk_size = MIN(bytes, s->cluster_size); 4545 4546 if (!aio && chunk_size != bytes) { 4547 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 4548 } 4549 4550 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry, 4551 0, 0, offset, chunk_size, qiov, qiov_offset, NULL); 4552 if (ret < 0) { 4553 break; 4554 } 4555 qiov_offset += chunk_size; 4556 offset += chunk_size; 4557 bytes -= chunk_size; 4558 } 4559 4560 if (aio) { 4561 aio_task_pool_wait_all(aio); 4562 if (ret == 0) { 4563 ret = aio_task_pool_status(aio); 4564 } 4565 g_free(aio); 4566 } 4567 4568 return ret; 4569 } 4570 4571 static int coroutine_fn 4572 qcow2_co_preadv_compressed(BlockDriverState *bs, 4573 uint64_t file_cluster_offset, 4574 uint64_t offset, 4575 uint64_t bytes, 4576 QEMUIOVector *qiov, 4577 size_t qiov_offset) 4578 { 4579 BDRVQcow2State *s = bs->opaque; 4580 int ret = 0, csize, nb_csectors; 4581 uint64_t coffset; 4582 uint8_t *buf, *out_buf; 4583 int offset_in_cluster = offset_into_cluster(s, offset); 4584 4585 coffset = file_cluster_offset & s->cluster_offset_mask; 4586 nb_csectors = ((file_cluster_offset >> s->csize_shift) & s->csize_mask) + 1; 4587 csize = nb_csectors * QCOW2_COMPRESSED_SECTOR_SIZE - 4588 (coffset & ~QCOW2_COMPRESSED_SECTOR_MASK); 4589 4590 buf = g_try_malloc(csize); 4591 if (!buf) { 4592 return -ENOMEM; 4593 } 4594 4595 out_buf = qemu_blockalign(bs, s->cluster_size); 4596 4597 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4598 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0); 4599 if (ret < 0) { 4600 goto fail; 4601 } 4602 4603 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4604 ret = -EIO; 4605 goto fail; 4606 } 4607 4608 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); 4609 4610 fail: 4611 qemu_vfree(out_buf); 4612 g_free(buf); 4613 4614 return ret; 4615 } 4616 4617 static int make_completely_empty(BlockDriverState *bs) 4618 { 4619 BDRVQcow2State *s = bs->opaque; 4620 Error *local_err = NULL; 4621 int ret, l1_clusters; 4622 int64_t offset; 4623 uint64_t *new_reftable = NULL; 4624 uint64_t rt_entry, l1_size2; 4625 struct { 4626 uint64_t l1_offset; 4627 uint64_t reftable_offset; 4628 uint32_t reftable_clusters; 4629 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4630 4631 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4632 if (ret < 0) { 4633 goto fail; 4634 } 4635 4636 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4637 if (ret < 0) { 4638 goto fail; 4639 } 4640 4641 /* Refcounts will be broken utterly */ 4642 ret = qcow2_mark_dirty(bs); 4643 if (ret < 0) { 4644 goto fail; 4645 } 4646 4647 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4648 4649 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4650 l1_size2 = (uint64_t)s->l1_size * sizeof(uint64_t); 4651 4652 /* After this call, neither the in-memory nor the on-disk refcount 4653 * information accurately describe the actual references */ 4654 4655 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4656 l1_clusters * s->cluster_size, 0); 4657 if (ret < 0) { 4658 goto fail_broken_refcounts; 4659 } 4660 memset(s->l1_table, 0, l1_size2); 4661 4662 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4663 4664 /* Overwrite enough clusters at the beginning of the sectors to place 4665 * the refcount table, a refcount block and the L1 table in; this may 4666 * overwrite parts of the existing refcount and L1 table, which is not 4667 * an issue because the dirty flag is set, complete data loss is in fact 4668 * desired and partial data loss is consequently fine as well */ 4669 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4670 (2 + l1_clusters) * s->cluster_size, 0); 4671 /* This call (even if it failed overall) may have overwritten on-disk 4672 * refcount structures; in that case, the in-memory refcount information 4673 * will probably differ from the on-disk information which makes the BDS 4674 * unusable */ 4675 if (ret < 0) { 4676 goto fail_broken_refcounts; 4677 } 4678 4679 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4680 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4681 4682 /* "Create" an empty reftable (one cluster) directly after the image 4683 * header and an empty L1 table three clusters after the image header; 4684 * the cluster between those two will be used as the first refblock */ 4685 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4686 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4687 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4688 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4689 &l1_ofs_rt_ofs_cls, sizeof(l1_ofs_rt_ofs_cls)); 4690 if (ret < 0) { 4691 goto fail_broken_refcounts; 4692 } 4693 4694 s->l1_table_offset = 3 * s->cluster_size; 4695 4696 new_reftable = g_try_new0(uint64_t, s->cluster_size / sizeof(uint64_t)); 4697 if (!new_reftable) { 4698 ret = -ENOMEM; 4699 goto fail_broken_refcounts; 4700 } 4701 4702 s->refcount_table_offset = s->cluster_size; 4703 s->refcount_table_size = s->cluster_size / sizeof(uint64_t); 4704 s->max_refcount_table_index = 0; 4705 4706 g_free(s->refcount_table); 4707 s->refcount_table = new_reftable; 4708 new_reftable = NULL; 4709 4710 /* Now the in-memory refcount information again corresponds to the on-disk 4711 * information (reftable is empty and no refblocks (the refblock cache is 4712 * empty)); however, this means some clusters (e.g. the image header) are 4713 * referenced, but not refcounted, but the normal qcow2 code assumes that 4714 * the in-memory information is always correct */ 4715 4716 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4717 4718 /* Enter the first refblock into the reftable */ 4719 rt_entry = cpu_to_be64(2 * s->cluster_size); 4720 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, 4721 &rt_entry, sizeof(rt_entry)); 4722 if (ret < 0) { 4723 goto fail_broken_refcounts; 4724 } 4725 s->refcount_table[0] = 2 * s->cluster_size; 4726 4727 s->free_cluster_index = 0; 4728 assert(3 + l1_clusters <= s->refcount_block_size); 4729 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4730 if (offset < 0) { 4731 ret = offset; 4732 goto fail_broken_refcounts; 4733 } else if (offset > 0) { 4734 error_report("First cluster in emptied image is in use"); 4735 abort(); 4736 } 4737 4738 /* Now finally the in-memory information corresponds to the on-disk 4739 * structures and is correct */ 4740 ret = qcow2_mark_clean(bs); 4741 if (ret < 0) { 4742 goto fail; 4743 } 4744 4745 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false, 4746 PREALLOC_MODE_OFF, 0, &local_err); 4747 if (ret < 0) { 4748 error_report_err(local_err); 4749 goto fail; 4750 } 4751 4752 return 0; 4753 4754 fail_broken_refcounts: 4755 /* The BDS is unusable at this point. If we wanted to make it usable, we 4756 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 4757 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 4758 * again. However, because the functions which could have caused this error 4759 * path to be taken are used by those functions as well, it's very likely 4760 * that that sequence will fail as well. Therefore, just eject the BDS. */ 4761 bs->drv = NULL; 4762 4763 fail: 4764 g_free(new_reftable); 4765 return ret; 4766 } 4767 4768 static int qcow2_make_empty(BlockDriverState *bs) 4769 { 4770 BDRVQcow2State *s = bs->opaque; 4771 uint64_t offset, end_offset; 4772 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 4773 int l1_clusters, ret = 0; 4774 4775 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4776 4777 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 4778 3 + l1_clusters <= s->refcount_block_size && 4779 s->crypt_method_header != QCOW_CRYPT_LUKS && 4780 !has_data_file(bs)) { 4781 /* The following function only works for qcow2 v3 images (it 4782 * requires the dirty flag) and only as long as there are no 4783 * features that reserve extra clusters (such as snapshots, 4784 * LUKS header, or persistent bitmaps), because it completely 4785 * empties the image. Furthermore, the L1 table and three 4786 * additional clusters (image header, refcount table, one 4787 * refcount block) have to fit inside one refcount block. It 4788 * only resets the image file, i.e. does not work with an 4789 * external data file. */ 4790 return make_completely_empty(bs); 4791 } 4792 4793 /* This fallback code simply discards every active cluster; this is slow, 4794 * but works in all cases */ 4795 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 4796 for (offset = 0; offset < end_offset; offset += step) { 4797 /* As this function is generally used after committing an external 4798 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 4799 * default action for this kind of discard is to pass the discard, 4800 * which will ideally result in an actually smaller image file, as 4801 * is probably desired. */ 4802 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 4803 QCOW2_DISCARD_SNAPSHOT, true); 4804 if (ret < 0) { 4805 break; 4806 } 4807 } 4808 4809 return ret; 4810 } 4811 4812 static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) 4813 { 4814 BDRVQcow2State *s = bs->opaque; 4815 int ret; 4816 4817 qemu_co_mutex_lock(&s->lock); 4818 ret = qcow2_write_caches(bs); 4819 qemu_co_mutex_unlock(&s->lock); 4820 4821 return ret; 4822 } 4823 4824 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 4825 Error **errp) 4826 { 4827 Error *local_err = NULL; 4828 BlockMeasureInfo *info; 4829 uint64_t required = 0; /* bytes that contribute to required size */ 4830 uint64_t virtual_size; /* disk size as seen by guest */ 4831 uint64_t refcount_bits; 4832 uint64_t l2_tables; 4833 uint64_t luks_payload_size = 0; 4834 size_t cluster_size; 4835 int version; 4836 char *optstr; 4837 PreallocMode prealloc; 4838 bool has_backing_file; 4839 bool has_luks; 4840 4841 /* Parse image creation options */ 4842 cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err); 4843 if (local_err) { 4844 goto err; 4845 } 4846 4847 version = qcow2_opt_get_version_del(opts, &local_err); 4848 if (local_err) { 4849 goto err; 4850 } 4851 4852 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 4853 if (local_err) { 4854 goto err; 4855 } 4856 4857 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 4858 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 4859 PREALLOC_MODE_OFF, &local_err); 4860 g_free(optstr); 4861 if (local_err) { 4862 goto err; 4863 } 4864 4865 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 4866 has_backing_file = !!optstr; 4867 g_free(optstr); 4868 4869 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 4870 has_luks = optstr && strcmp(optstr, "luks") == 0; 4871 g_free(optstr); 4872 4873 if (has_luks) { 4874 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL; 4875 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp); 4876 size_t headerlen; 4877 4878 create_opts = block_crypto_create_opts_init(cryptoopts, errp); 4879 qobject_unref(cryptoopts); 4880 if (!create_opts) { 4881 goto err; 4882 } 4883 4884 if (!qcrypto_block_calculate_payload_offset(create_opts, 4885 "encrypt.", 4886 &headerlen, 4887 &local_err)) { 4888 goto err; 4889 } 4890 4891 luks_payload_size = ROUND_UP(headerlen, cluster_size); 4892 } 4893 4894 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 4895 virtual_size = ROUND_UP(virtual_size, cluster_size); 4896 4897 /* Check that virtual disk size is valid */ 4898 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 4899 cluster_size / sizeof(uint64_t)); 4900 if (l2_tables * sizeof(uint64_t) > QCOW_MAX_L1_SIZE) { 4901 error_setg(&local_err, "The image size is too large " 4902 "(try using a larger cluster size)"); 4903 goto err; 4904 } 4905 4906 /* Account for input image */ 4907 if (in_bs) { 4908 int64_t ssize = bdrv_getlength(in_bs); 4909 if (ssize < 0) { 4910 error_setg_errno(&local_err, -ssize, 4911 "Unable to get image virtual_size"); 4912 goto err; 4913 } 4914 4915 virtual_size = ROUND_UP(ssize, cluster_size); 4916 4917 if (has_backing_file) { 4918 /* We don't how much of the backing chain is shared by the input 4919 * image and the new image file. In the worst case the new image's 4920 * backing file has nothing in common with the input image. Be 4921 * conservative and assume all clusters need to be written. 4922 */ 4923 required = virtual_size; 4924 } else { 4925 int64_t offset; 4926 int64_t pnum = 0; 4927 4928 for (offset = 0; offset < ssize; offset += pnum) { 4929 int ret; 4930 4931 ret = bdrv_block_status_above(in_bs, NULL, offset, 4932 ssize - offset, &pnum, NULL, 4933 NULL); 4934 if (ret < 0) { 4935 error_setg_errno(&local_err, -ret, 4936 "Unable to get block status"); 4937 goto err; 4938 } 4939 4940 if (ret & BDRV_BLOCK_ZERO) { 4941 /* Skip zero regions (safe with no backing file) */ 4942 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 4943 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 4944 /* Extend pnum to end of cluster for next iteration */ 4945 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 4946 4947 /* Count clusters we've seen */ 4948 required += offset % cluster_size + pnum; 4949 } 4950 } 4951 } 4952 } 4953 4954 /* Take into account preallocation. Nothing special is needed for 4955 * PREALLOC_MODE_METADATA since metadata is always counted. 4956 */ 4957 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 4958 required = virtual_size; 4959 } 4960 4961 info = g_new0(BlockMeasureInfo, 1); 4962 info->fully_allocated = 4963 qcow2_calc_prealloc_size(virtual_size, cluster_size, 4964 ctz32(refcount_bits)) + luks_payload_size; 4965 4966 /* 4967 * Remove data clusters that are not required. This overestimates the 4968 * required size because metadata needed for the fully allocated file is 4969 * still counted. Show bitmaps only if both source and destination 4970 * would support them. 4971 */ 4972 info->required = info->fully_allocated - virtual_size + required; 4973 info->has_bitmaps = version >= 3 && in_bs && 4974 bdrv_supports_persistent_dirty_bitmap(in_bs); 4975 if (info->has_bitmaps) { 4976 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs, 4977 cluster_size); 4978 } 4979 return info; 4980 4981 err: 4982 error_propagate(errp, local_err); 4983 return NULL; 4984 } 4985 4986 static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 4987 { 4988 BDRVQcow2State *s = bs->opaque; 4989 bdi->cluster_size = s->cluster_size; 4990 bdi->vm_state_offset = qcow2_vm_state_offset(s); 4991 return 0; 4992 } 4993 4994 static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs, 4995 Error **errp) 4996 { 4997 BDRVQcow2State *s = bs->opaque; 4998 ImageInfoSpecific *spec_info; 4999 QCryptoBlockInfo *encrypt_info = NULL; 5000 Error *local_err = NULL; 5001 5002 if (s->crypto != NULL) { 5003 encrypt_info = qcrypto_block_get_info(s->crypto, &local_err); 5004 if (local_err) { 5005 error_propagate(errp, local_err); 5006 return NULL; 5007 } 5008 } 5009 5010 spec_info = g_new(ImageInfoSpecific, 1); 5011 *spec_info = (ImageInfoSpecific){ 5012 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 5013 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 5014 }; 5015 if (s->qcow_version == 2) { 5016 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5017 .compat = g_strdup("0.10"), 5018 .refcount_bits = s->refcount_bits, 5019 }; 5020 } else if (s->qcow_version == 3) { 5021 Qcow2BitmapInfoList *bitmaps; 5022 bitmaps = qcow2_get_bitmap_info_list(bs, &local_err); 5023 if (local_err) { 5024 error_propagate(errp, local_err); 5025 qapi_free_ImageInfoSpecific(spec_info); 5026 qapi_free_QCryptoBlockInfo(encrypt_info); 5027 return NULL; 5028 } 5029 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5030 .compat = g_strdup("1.1"), 5031 .lazy_refcounts = s->compatible_features & 5032 QCOW2_COMPAT_LAZY_REFCOUNTS, 5033 .has_lazy_refcounts = true, 5034 .corrupt = s->incompatible_features & 5035 QCOW2_INCOMPAT_CORRUPT, 5036 .has_corrupt = true, 5037 .refcount_bits = s->refcount_bits, 5038 .has_bitmaps = !!bitmaps, 5039 .bitmaps = bitmaps, 5040 .has_data_file = !!s->image_data_file, 5041 .data_file = g_strdup(s->image_data_file), 5042 .has_data_file_raw = has_data_file(bs), 5043 .data_file_raw = data_file_is_raw(bs), 5044 .compression_type = s->compression_type, 5045 }; 5046 } else { 5047 /* if this assertion fails, this probably means a new version was 5048 * added without having it covered here */ 5049 assert(false); 5050 } 5051 5052 if (encrypt_info) { 5053 ImageInfoSpecificQCow2Encryption *qencrypt = 5054 g_new(ImageInfoSpecificQCow2Encryption, 1); 5055 switch (encrypt_info->format) { 5056 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 5057 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 5058 break; 5059 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 5060 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 5061 qencrypt->u.luks = encrypt_info->u.luks; 5062 break; 5063 default: 5064 abort(); 5065 } 5066 /* Since we did shallow copy above, erase any pointers 5067 * in the original info */ 5068 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 5069 qapi_free_QCryptoBlockInfo(encrypt_info); 5070 5071 spec_info->u.qcow2.data->has_encrypt = true; 5072 spec_info->u.qcow2.data->encrypt = qencrypt; 5073 } 5074 5075 return spec_info; 5076 } 5077 5078 static int qcow2_has_zero_init(BlockDriverState *bs) 5079 { 5080 BDRVQcow2State *s = bs->opaque; 5081 bool preallocated; 5082 5083 if (qemu_in_coroutine()) { 5084 qemu_co_mutex_lock(&s->lock); 5085 } 5086 /* 5087 * Check preallocation status: Preallocated images have all L2 5088 * tables allocated, nonpreallocated images have none. It is 5089 * therefore enough to check the first one. 5090 */ 5091 preallocated = s->l1_size > 0 && s->l1_table[0] != 0; 5092 if (qemu_in_coroutine()) { 5093 qemu_co_mutex_unlock(&s->lock); 5094 } 5095 5096 if (!preallocated) { 5097 return 1; 5098 } else if (bs->encrypted) { 5099 return 0; 5100 } else { 5101 return bdrv_has_zero_init(s->data_file->bs); 5102 } 5103 } 5104 5105 static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 5106 int64_t pos) 5107 { 5108 BDRVQcow2State *s = bs->opaque; 5109 5110 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 5111 return bs->drv->bdrv_co_pwritev_part(bs, qcow2_vm_state_offset(s) + pos, 5112 qiov->size, qiov, 0, 0); 5113 } 5114 5115 static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 5116 int64_t pos) 5117 { 5118 BDRVQcow2State *s = bs->opaque; 5119 5120 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 5121 return bs->drv->bdrv_co_preadv_part(bs, qcow2_vm_state_offset(s) + pos, 5122 qiov->size, qiov, 0, 0); 5123 } 5124 5125 /* 5126 * Downgrades an image's version. To achieve this, any incompatible features 5127 * have to be removed. 5128 */ 5129 static int qcow2_downgrade(BlockDriverState *bs, int target_version, 5130 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5131 Error **errp) 5132 { 5133 BDRVQcow2State *s = bs->opaque; 5134 int current_version = s->qcow_version; 5135 int ret; 5136 int i; 5137 5138 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 5139 assert(target_version < current_version); 5140 5141 /* There are no other versions (now) that you can downgrade to */ 5142 assert(target_version == 2); 5143 5144 if (s->refcount_order != 4) { 5145 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 5146 return -ENOTSUP; 5147 } 5148 5149 if (has_data_file(bs)) { 5150 error_setg(errp, "Cannot downgrade an image with a data file"); 5151 return -ENOTSUP; 5152 } 5153 5154 /* 5155 * If any internal snapshot has a different size than the current 5156 * image size, or VM state size that exceeds 32 bits, downgrading 5157 * is unsafe. Even though we would still use v3-compliant output 5158 * to preserve that data, other v2 programs might not realize 5159 * those optional fields are important. 5160 */ 5161 for (i = 0; i < s->nb_snapshots; i++) { 5162 if (s->snapshots[i].vm_state_size > UINT32_MAX || 5163 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { 5164 error_setg(errp, "Internal snapshots prevent downgrade of image"); 5165 return -ENOTSUP; 5166 } 5167 } 5168 5169 /* clear incompatible features */ 5170 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 5171 ret = qcow2_mark_clean(bs); 5172 if (ret < 0) { 5173 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5174 return ret; 5175 } 5176 } 5177 5178 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 5179 * the first place; if that happens nonetheless, returning -ENOTSUP is the 5180 * best thing to do anyway */ 5181 5182 if (s->incompatible_features) { 5183 error_setg(errp, "Cannot downgrade an image with incompatible features " 5184 "%#" PRIx64 " set", s->incompatible_features); 5185 return -ENOTSUP; 5186 } 5187 5188 /* since we can ignore compatible features, we can set them to 0 as well */ 5189 s->compatible_features = 0; 5190 /* if lazy refcounts have been used, they have already been fixed through 5191 * clearing the dirty flag */ 5192 5193 /* clearing autoclear features is trivial */ 5194 s->autoclear_features = 0; 5195 5196 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 5197 if (ret < 0) { 5198 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 5199 return ret; 5200 } 5201 5202 s->qcow_version = target_version; 5203 ret = qcow2_update_header(bs); 5204 if (ret < 0) { 5205 s->qcow_version = current_version; 5206 error_setg_errno(errp, -ret, "Failed to update the image header"); 5207 return ret; 5208 } 5209 return 0; 5210 } 5211 5212 /* 5213 * Upgrades an image's version. While newer versions encompass all 5214 * features of older versions, some things may have to be presented 5215 * differently. 5216 */ 5217 static int qcow2_upgrade(BlockDriverState *bs, int target_version, 5218 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5219 Error **errp) 5220 { 5221 BDRVQcow2State *s = bs->opaque; 5222 bool need_snapshot_update; 5223 int current_version = s->qcow_version; 5224 int i; 5225 int ret; 5226 5227 /* This is qcow2_upgrade(), not qcow2_downgrade() */ 5228 assert(target_version > current_version); 5229 5230 /* There are no other versions (yet) that you can upgrade to */ 5231 assert(target_version == 3); 5232 5233 status_cb(bs, 0, 2, cb_opaque); 5234 5235 /* 5236 * In v2, snapshots do not need to have extra data. v3 requires 5237 * the 64-bit VM state size and the virtual disk size to be 5238 * present. 5239 * qcow2_write_snapshots() will always write the list in the 5240 * v3-compliant format. 5241 */ 5242 need_snapshot_update = false; 5243 for (i = 0; i < s->nb_snapshots; i++) { 5244 if (s->snapshots[i].extra_data_size < 5245 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) + 5246 sizeof_field(QCowSnapshotExtraData, disk_size)) 5247 { 5248 need_snapshot_update = true; 5249 break; 5250 } 5251 } 5252 if (need_snapshot_update) { 5253 ret = qcow2_write_snapshots(bs); 5254 if (ret < 0) { 5255 error_setg_errno(errp, -ret, "Failed to update the snapshot table"); 5256 return ret; 5257 } 5258 } 5259 status_cb(bs, 1, 2, cb_opaque); 5260 5261 s->qcow_version = target_version; 5262 ret = qcow2_update_header(bs); 5263 if (ret < 0) { 5264 s->qcow_version = current_version; 5265 error_setg_errno(errp, -ret, "Failed to update the image header"); 5266 return ret; 5267 } 5268 status_cb(bs, 2, 2, cb_opaque); 5269 5270 return 0; 5271 } 5272 5273 typedef enum Qcow2AmendOperation { 5274 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 5275 * statically initialized to so that the helper CB can discern the first 5276 * invocation from an operation change */ 5277 QCOW2_NO_OPERATION = 0, 5278 5279 QCOW2_UPGRADING, 5280 QCOW2_UPDATING_ENCRYPTION, 5281 QCOW2_CHANGING_REFCOUNT_ORDER, 5282 QCOW2_DOWNGRADING, 5283 } Qcow2AmendOperation; 5284 5285 typedef struct Qcow2AmendHelperCBInfo { 5286 /* The code coordinating the amend operations should only modify 5287 * these four fields; the rest will be managed by the CB */ 5288 BlockDriverAmendStatusCB *original_status_cb; 5289 void *original_cb_opaque; 5290 5291 Qcow2AmendOperation current_operation; 5292 5293 /* Total number of operations to perform (only set once) */ 5294 int total_operations; 5295 5296 /* The following fields are managed by the CB */ 5297 5298 /* Number of operations completed */ 5299 int operations_completed; 5300 5301 /* Cumulative offset of all completed operations */ 5302 int64_t offset_completed; 5303 5304 Qcow2AmendOperation last_operation; 5305 int64_t last_work_size; 5306 } Qcow2AmendHelperCBInfo; 5307 5308 static void qcow2_amend_helper_cb(BlockDriverState *bs, 5309 int64_t operation_offset, 5310 int64_t operation_work_size, void *opaque) 5311 { 5312 Qcow2AmendHelperCBInfo *info = opaque; 5313 int64_t current_work_size; 5314 int64_t projected_work_size; 5315 5316 if (info->current_operation != info->last_operation) { 5317 if (info->last_operation != QCOW2_NO_OPERATION) { 5318 info->offset_completed += info->last_work_size; 5319 info->operations_completed++; 5320 } 5321 5322 info->last_operation = info->current_operation; 5323 } 5324 5325 assert(info->total_operations > 0); 5326 assert(info->operations_completed < info->total_operations); 5327 5328 info->last_work_size = operation_work_size; 5329 5330 current_work_size = info->offset_completed + operation_work_size; 5331 5332 /* current_work_size is the total work size for (operations_completed + 1) 5333 * operations (which includes this one), so multiply it by the number of 5334 * operations not covered and divide it by the number of operations 5335 * covered to get a projection for the operations not covered */ 5336 projected_work_size = current_work_size * (info->total_operations - 5337 info->operations_completed - 1) 5338 / (info->operations_completed + 1); 5339 5340 info->original_status_cb(bs, info->offset_completed + operation_offset, 5341 current_work_size + projected_work_size, 5342 info->original_cb_opaque); 5343 } 5344 5345 static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 5346 BlockDriverAmendStatusCB *status_cb, 5347 void *cb_opaque, 5348 bool force, 5349 Error **errp) 5350 { 5351 BDRVQcow2State *s = bs->opaque; 5352 int old_version = s->qcow_version, new_version = old_version; 5353 uint64_t new_size = 0; 5354 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 5355 bool lazy_refcounts = s->use_lazy_refcounts; 5356 bool data_file_raw = data_file_is_raw(bs); 5357 const char *compat = NULL; 5358 int refcount_bits = s->refcount_bits; 5359 int ret; 5360 QemuOptDesc *desc = opts->list->desc; 5361 Qcow2AmendHelperCBInfo helper_cb_info; 5362 bool encryption_update = false; 5363 5364 while (desc && desc->name) { 5365 if (!qemu_opt_find(opts, desc->name)) { 5366 /* only change explicitly defined options */ 5367 desc++; 5368 continue; 5369 } 5370 5371 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 5372 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 5373 if (!compat) { 5374 /* preserve default */ 5375 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) { 5376 new_version = 2; 5377 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) { 5378 new_version = 3; 5379 } else { 5380 error_setg(errp, "Unknown compatibility level %s", compat); 5381 return -EINVAL; 5382 } 5383 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 5384 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 5385 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 5386 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 5387 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 5388 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 5389 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 5390 if (!s->crypto) { 5391 error_setg(errp, 5392 "Can't amend encryption options - encryption not present"); 5393 return -EINVAL; 5394 } 5395 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5396 error_setg(errp, 5397 "Only LUKS encryption options can be amended"); 5398 return -ENOTSUP; 5399 } 5400 encryption_update = true; 5401 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 5402 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 5403 lazy_refcounts); 5404 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 5405 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 5406 refcount_bits); 5407 5408 if (refcount_bits <= 0 || refcount_bits > 64 || 5409 !is_power_of_2(refcount_bits)) 5410 { 5411 error_setg(errp, "Refcount width must be a power of two and " 5412 "may not exceed 64 bits"); 5413 return -EINVAL; 5414 } 5415 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 5416 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 5417 if (data_file && !has_data_file(bs)) { 5418 error_setg(errp, "data-file can only be set for images that " 5419 "use an external data file"); 5420 return -EINVAL; 5421 } 5422 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 5423 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 5424 data_file_raw); 5425 if (data_file_raw && !data_file_is_raw(bs)) { 5426 error_setg(errp, "data-file-raw cannot be set on existing " 5427 "images"); 5428 return -EINVAL; 5429 } 5430 } else { 5431 /* if this point is reached, this probably means a new option was 5432 * added without having it covered here */ 5433 abort(); 5434 } 5435 5436 desc++; 5437 } 5438 5439 helper_cb_info = (Qcow2AmendHelperCBInfo){ 5440 .original_status_cb = status_cb, 5441 .original_cb_opaque = cb_opaque, 5442 .total_operations = (new_version != old_version) 5443 + (s->refcount_bits != refcount_bits) + 5444 (encryption_update == true) 5445 }; 5446 5447 /* Upgrade first (some features may require compat=1.1) */ 5448 if (new_version > old_version) { 5449 helper_cb_info.current_operation = QCOW2_UPGRADING; 5450 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb, 5451 &helper_cb_info, errp); 5452 if (ret < 0) { 5453 return ret; 5454 } 5455 } 5456 5457 if (encryption_update) { 5458 QDict *amend_opts_dict; 5459 QCryptoBlockAmendOptions *amend_opts; 5460 5461 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION; 5462 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp); 5463 if (!amend_opts_dict) { 5464 return -EINVAL; 5465 } 5466 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp); 5467 qobject_unref(amend_opts_dict); 5468 if (!amend_opts) { 5469 return -EINVAL; 5470 } 5471 ret = qcrypto_block_amend_options(s->crypto, 5472 qcow2_crypto_hdr_read_func, 5473 qcow2_crypto_hdr_write_func, 5474 bs, 5475 amend_opts, 5476 force, 5477 errp); 5478 qapi_free_QCryptoBlockAmendOptions(amend_opts); 5479 if (ret < 0) { 5480 return ret; 5481 } 5482 } 5483 5484 if (s->refcount_bits != refcount_bits) { 5485 int refcount_order = ctz32(refcount_bits); 5486 5487 if (new_version < 3 && refcount_bits != 16) { 5488 error_setg(errp, "Refcount widths other than 16 bits require " 5489 "compatibility level 1.1 or above (use compat=1.1 or " 5490 "greater)"); 5491 return -EINVAL; 5492 } 5493 5494 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 5495 ret = qcow2_change_refcount_order(bs, refcount_order, 5496 &qcow2_amend_helper_cb, 5497 &helper_cb_info, errp); 5498 if (ret < 0) { 5499 return ret; 5500 } 5501 } 5502 5503 /* data-file-raw blocks backing files, so clear it first if requested */ 5504 if (data_file_raw) { 5505 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5506 } else { 5507 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5508 } 5509 5510 if (data_file) { 5511 g_free(s->image_data_file); 5512 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 5513 } 5514 5515 ret = qcow2_update_header(bs); 5516 if (ret < 0) { 5517 error_setg_errno(errp, -ret, "Failed to update the image header"); 5518 return ret; 5519 } 5520 5521 if (backing_file || backing_format) { 5522 ret = qcow2_change_backing_file(bs, 5523 backing_file ?: s->image_backing_file, 5524 backing_format ?: s->image_backing_format); 5525 if (ret < 0) { 5526 error_setg_errno(errp, -ret, "Failed to change the backing file"); 5527 return ret; 5528 } 5529 } 5530 5531 if (s->use_lazy_refcounts != lazy_refcounts) { 5532 if (lazy_refcounts) { 5533 if (new_version < 3) { 5534 error_setg(errp, "Lazy refcounts only supported with " 5535 "compatibility level 1.1 and above (use compat=1.1 " 5536 "or greater)"); 5537 return -EINVAL; 5538 } 5539 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5540 ret = qcow2_update_header(bs); 5541 if (ret < 0) { 5542 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5543 error_setg_errno(errp, -ret, "Failed to update the image header"); 5544 return ret; 5545 } 5546 s->use_lazy_refcounts = true; 5547 } else { 5548 /* make image clean first */ 5549 ret = qcow2_mark_clean(bs); 5550 if (ret < 0) { 5551 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5552 return ret; 5553 } 5554 /* now disallow lazy refcounts */ 5555 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5556 ret = qcow2_update_header(bs); 5557 if (ret < 0) { 5558 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5559 error_setg_errno(errp, -ret, "Failed to update the image header"); 5560 return ret; 5561 } 5562 s->use_lazy_refcounts = false; 5563 } 5564 } 5565 5566 if (new_size) { 5567 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, 5568 errp); 5569 if (!blk) { 5570 return -EPERM; 5571 } 5572 5573 /* 5574 * Amending image options should ensure that the image has 5575 * exactly the given new values, so pass exact=true here. 5576 */ 5577 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp); 5578 blk_unref(blk); 5579 if (ret < 0) { 5580 return ret; 5581 } 5582 } 5583 5584 /* Downgrade last (so unsupported features can be removed before) */ 5585 if (new_version < old_version) { 5586 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5587 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5588 &helper_cb_info, errp); 5589 if (ret < 0) { 5590 return ret; 5591 } 5592 } 5593 5594 return 0; 5595 } 5596 5597 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs, 5598 BlockdevAmendOptions *opts, 5599 bool force, 5600 Error **errp) 5601 { 5602 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2; 5603 BDRVQcow2State *s = bs->opaque; 5604 int ret = 0; 5605 5606 if (qopts->has_encrypt) { 5607 if (!s->crypto) { 5608 error_setg(errp, "image is not encrypted, can't amend"); 5609 return -EOPNOTSUPP; 5610 } 5611 5612 if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) { 5613 error_setg(errp, 5614 "Amend can't be used to change the qcow2 encryption format"); 5615 return -EOPNOTSUPP; 5616 } 5617 5618 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5619 error_setg(errp, 5620 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend"); 5621 return -EOPNOTSUPP; 5622 } 5623 5624 ret = qcrypto_block_amend_options(s->crypto, 5625 qcow2_crypto_hdr_read_func, 5626 qcow2_crypto_hdr_write_func, 5627 bs, 5628 qopts->encrypt, 5629 force, 5630 errp); 5631 } 5632 return ret; 5633 } 5634 5635 /* 5636 * If offset or size are negative, respectively, they will not be included in 5637 * the BLOCK_IMAGE_CORRUPTED event emitted. 5638 * fatal will be ignored for read-only BDS; corruptions found there will always 5639 * be considered non-fatal. 5640 */ 5641 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5642 int64_t size, const char *message_format, ...) 5643 { 5644 BDRVQcow2State *s = bs->opaque; 5645 const char *node_name; 5646 char *message; 5647 va_list ap; 5648 5649 fatal = fatal && bdrv_is_writable(bs); 5650 5651 if (s->signaled_corruption && 5652 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5653 { 5654 return; 5655 } 5656 5657 va_start(ap, message_format); 5658 message = g_strdup_vprintf(message_format, ap); 5659 va_end(ap); 5660 5661 if (fatal) { 5662 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 5663 "corruption events will be suppressed\n", message); 5664 } else { 5665 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 5666 "corruption events will be suppressed\n", message); 5667 } 5668 5669 node_name = bdrv_get_node_name(bs); 5670 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 5671 *node_name != '\0', node_name, 5672 message, offset >= 0, offset, 5673 size >= 0, size, 5674 fatal); 5675 g_free(message); 5676 5677 if (fatal) { 5678 qcow2_mark_corrupt(bs); 5679 bs->drv = NULL; /* make BDS unusable */ 5680 } 5681 5682 s->signaled_corruption = true; 5683 } 5684 5685 #define QCOW_COMMON_OPTIONS \ 5686 { \ 5687 .name = BLOCK_OPT_SIZE, \ 5688 .type = QEMU_OPT_SIZE, \ 5689 .help = "Virtual disk size" \ 5690 }, \ 5691 { \ 5692 .name = BLOCK_OPT_COMPAT_LEVEL, \ 5693 .type = QEMU_OPT_STRING, \ 5694 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \ 5695 }, \ 5696 { \ 5697 .name = BLOCK_OPT_BACKING_FILE, \ 5698 .type = QEMU_OPT_STRING, \ 5699 .help = "File name of a base image" \ 5700 }, \ 5701 { \ 5702 .name = BLOCK_OPT_BACKING_FMT, \ 5703 .type = QEMU_OPT_STRING, \ 5704 .help = "Image format of the base image" \ 5705 }, \ 5706 { \ 5707 .name = BLOCK_OPT_DATA_FILE, \ 5708 .type = QEMU_OPT_STRING, \ 5709 .help = "File name of an external data file" \ 5710 }, \ 5711 { \ 5712 .name = BLOCK_OPT_DATA_FILE_RAW, \ 5713 .type = QEMU_OPT_BOOL, \ 5714 .help = "The external data file must stay valid " \ 5715 "as a raw image" \ 5716 }, \ 5717 { \ 5718 .name = BLOCK_OPT_LAZY_REFCOUNTS, \ 5719 .type = QEMU_OPT_BOOL, \ 5720 .help = "Postpone refcount updates", \ 5721 .def_value_str = "off" \ 5722 }, \ 5723 { \ 5724 .name = BLOCK_OPT_REFCOUNT_BITS, \ 5725 .type = QEMU_OPT_NUMBER, \ 5726 .help = "Width of a reference count entry in bits", \ 5727 .def_value_str = "16" \ 5728 } 5729 5730 static QemuOptsList qcow2_create_opts = { 5731 .name = "qcow2-create-opts", 5732 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 5733 .desc = { 5734 { \ 5735 .name = BLOCK_OPT_ENCRYPT, \ 5736 .type = QEMU_OPT_BOOL, \ 5737 .help = "Encrypt the image with format 'aes'. (Deprecated " \ 5738 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \ 5739 }, \ 5740 { \ 5741 .name = BLOCK_OPT_ENCRYPT_FORMAT, \ 5742 .type = QEMU_OPT_STRING, \ 5743 .help = "Encrypt the image, format choices: 'aes', 'luks'", \ 5744 }, \ 5745 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \ 5746 "ID of secret providing qcow AES key or LUKS passphrase"), \ 5747 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \ 5748 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \ 5749 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \ 5750 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \ 5751 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \ 5752 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \ 5753 { \ 5754 .name = BLOCK_OPT_CLUSTER_SIZE, \ 5755 .type = QEMU_OPT_SIZE, \ 5756 .help = "qcow2 cluster size", \ 5757 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \ 5758 }, \ 5759 { \ 5760 .name = BLOCK_OPT_PREALLOC, \ 5761 .type = QEMU_OPT_STRING, \ 5762 .help = "Preallocation mode (allowed values: off, " \ 5763 "metadata, falloc, full)" \ 5764 }, \ 5765 { \ 5766 .name = BLOCK_OPT_COMPRESSION_TYPE, \ 5767 .type = QEMU_OPT_STRING, \ 5768 .help = "Compression method used for image cluster " \ 5769 "compression", \ 5770 .def_value_str = "zlib" \ 5771 }, 5772 QCOW_COMMON_OPTIONS, 5773 { /* end of list */ } 5774 } 5775 }; 5776 5777 static QemuOptsList qcow2_amend_opts = { 5778 .name = "qcow2-amend-opts", 5779 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head), 5780 .desc = { 5781 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."), 5782 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."), 5783 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."), 5784 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."), 5785 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 5786 QCOW_COMMON_OPTIONS, 5787 { /* end of list */ } 5788 } 5789 }; 5790 5791 static const char *const qcow2_strong_runtime_opts[] = { 5792 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 5793 5794 NULL 5795 }; 5796 5797 BlockDriver bdrv_qcow2 = { 5798 .format_name = "qcow2", 5799 .instance_size = sizeof(BDRVQcow2State), 5800 .bdrv_probe = qcow2_probe, 5801 .bdrv_open = qcow2_open, 5802 .bdrv_close = qcow2_close, 5803 .bdrv_reopen_prepare = qcow2_reopen_prepare, 5804 .bdrv_reopen_commit = qcow2_reopen_commit, 5805 .bdrv_reopen_commit_post = qcow2_reopen_commit_post, 5806 .bdrv_reopen_abort = qcow2_reopen_abort, 5807 .bdrv_join_options = qcow2_join_options, 5808 .bdrv_child_perm = bdrv_default_perms, 5809 .bdrv_co_create_opts = qcow2_co_create_opts, 5810 .bdrv_co_create = qcow2_co_create, 5811 .bdrv_has_zero_init = qcow2_has_zero_init, 5812 .bdrv_co_block_status = qcow2_co_block_status, 5813 5814 .bdrv_co_preadv_part = qcow2_co_preadv_part, 5815 .bdrv_co_pwritev_part = qcow2_co_pwritev_part, 5816 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 5817 5818 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 5819 .bdrv_co_pdiscard = qcow2_co_pdiscard, 5820 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 5821 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 5822 .bdrv_co_truncate = qcow2_co_truncate, 5823 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part, 5824 .bdrv_make_empty = qcow2_make_empty, 5825 5826 .bdrv_snapshot_create = qcow2_snapshot_create, 5827 .bdrv_snapshot_goto = qcow2_snapshot_goto, 5828 .bdrv_snapshot_delete = qcow2_snapshot_delete, 5829 .bdrv_snapshot_list = qcow2_snapshot_list, 5830 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 5831 .bdrv_measure = qcow2_measure, 5832 .bdrv_get_info = qcow2_get_info, 5833 .bdrv_get_specific_info = qcow2_get_specific_info, 5834 5835 .bdrv_save_vmstate = qcow2_save_vmstate, 5836 .bdrv_load_vmstate = qcow2_load_vmstate, 5837 5838 .is_format = true, 5839 .supports_backing = true, 5840 .bdrv_change_backing_file = qcow2_change_backing_file, 5841 5842 .bdrv_refresh_limits = qcow2_refresh_limits, 5843 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 5844 .bdrv_inactivate = qcow2_inactivate, 5845 5846 .create_opts = &qcow2_create_opts, 5847 .amend_opts = &qcow2_amend_opts, 5848 .strong_runtime_opts = qcow2_strong_runtime_opts, 5849 .mutable_opts = mutable_opts, 5850 .bdrv_co_check = qcow2_co_check, 5851 .bdrv_amend_options = qcow2_amend_options, 5852 .bdrv_co_amend = qcow2_co_amend, 5853 5854 .bdrv_detach_aio_context = qcow2_detach_aio_context, 5855 .bdrv_attach_aio_context = qcow2_attach_aio_context, 5856 5857 .bdrv_supports_persistent_dirty_bitmap = 5858 qcow2_supports_persistent_dirty_bitmap, 5859 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap, 5860 .bdrv_co_remove_persistent_dirty_bitmap = 5861 qcow2_co_remove_persistent_dirty_bitmap, 5862 }; 5863 5864 static void bdrv_qcow2_init(void) 5865 { 5866 bdrv_register(&bdrv_qcow2); 5867 } 5868 5869 block_init(bdrv_qcow2_init); 5870