1 /* 2 * Block driver for the QCOW version 2 format 3 * 4 * Copyright (c) 2004-2006 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 27 #include "block/qdict.h" 28 #include "sysemu/block-backend.h" 29 #include "qemu/main-loop.h" 30 #include "qemu/module.h" 31 #include "qcow2.h" 32 #include "qemu/error-report.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-events-block-core.h" 35 #include "qapi/qmp/qdict.h" 36 #include "qapi/qmp/qstring.h" 37 #include "trace.h" 38 #include "qemu/option_int.h" 39 #include "qemu/cutils.h" 40 #include "qemu/bswap.h" 41 #include "qemu/memalign.h" 42 #include "qapi/qobject-input-visitor.h" 43 #include "qapi/qapi-visit-block-core.h" 44 #include "crypto.h" 45 #include "block/aio_task.h" 46 #include "block/dirty-bitmap.h" 47 48 /* 49 Differences with QCOW: 50 51 - Support for multiple incremental snapshots. 52 - Memory management by reference counts. 53 - Clusters which have a reference count of one have the bit 54 QCOW_OFLAG_COPIED to optimize write performance. 55 - Size of compressed clusters is stored in sectors to reduce bit usage 56 in the cluster offsets. 57 - Support for storing additional data (such as the VM state) in the 58 snapshots. 59 - If a backing store is used, the cluster size is not constrained 60 (could be backported to QCOW). 61 - L2 tables have always a size of one cluster. 62 */ 63 64 65 typedef struct { 66 uint32_t magic; 67 uint32_t len; 68 } QEMU_PACKED QCowExtension; 69 70 #define QCOW2_EXT_MAGIC_END 0 71 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca 72 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 73 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 74 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 75 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 76 77 static int coroutine_fn 78 qcow2_co_preadv_compressed(BlockDriverState *bs, 79 uint64_t l2_entry, 80 uint64_t offset, 81 uint64_t bytes, 82 QEMUIOVector *qiov, 83 size_t qiov_offset); 84 85 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) 86 { 87 const QCowHeader *cow_header = (const void *)buf; 88 89 if (buf_size >= sizeof(QCowHeader) && 90 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 91 be32_to_cpu(cow_header->version) >= 2) 92 return 100; 93 else 94 return 0; 95 } 96 97 98 static int GRAPH_RDLOCK 99 qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, 100 uint8_t *buf, size_t buflen, 101 void *opaque, Error **errp) 102 { 103 BlockDriverState *bs = opaque; 104 BDRVQcow2State *s = bs->opaque; 105 ssize_t ret; 106 107 if ((offset + buflen) > s->crypto_header.length) { 108 error_setg(errp, "Request for data outside of extension header"); 109 return -1; 110 } 111 112 ret = bdrv_pread(bs->file, s->crypto_header.offset + offset, buflen, buf, 113 0); 114 if (ret < 0) { 115 error_setg_errno(errp, -ret, "Could not read encryption header"); 116 return -1; 117 } 118 return 0; 119 } 120 121 122 static int coroutine_fn GRAPH_RDLOCK 123 qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, void *opaque, 124 Error **errp) 125 { 126 BlockDriverState *bs = opaque; 127 BDRVQcow2State *s = bs->opaque; 128 int64_t ret; 129 int64_t clusterlen; 130 131 ret = qcow2_alloc_clusters(bs, headerlen); 132 if (ret < 0) { 133 error_setg_errno(errp, -ret, 134 "Cannot allocate cluster for LUKS header size %zu", 135 headerlen); 136 return -1; 137 } 138 139 s->crypto_header.length = headerlen; 140 s->crypto_header.offset = ret; 141 142 /* 143 * Zero fill all space in cluster so it has predictable 144 * content, as we may not initialize some regions of the 145 * header (eg only 1 out of 8 key slots will be initialized) 146 */ 147 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; 148 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); 149 ret = bdrv_co_pwrite_zeroes(bs->file, ret, clusterlen, 0); 150 if (ret < 0) { 151 error_setg_errno(errp, -ret, "Could not zero fill encryption header"); 152 return -1; 153 } 154 155 return 0; 156 } 157 158 159 /* The graph lock must be held when called in coroutine context */ 160 static int coroutine_mixed_fn GRAPH_RDLOCK 161 qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, 162 const uint8_t *buf, size_t buflen, 163 void *opaque, Error **errp) 164 { 165 BlockDriverState *bs = opaque; 166 BDRVQcow2State *s = bs->opaque; 167 ssize_t ret; 168 169 if ((offset + buflen) > s->crypto_header.length) { 170 error_setg(errp, "Request for data outside of extension header"); 171 return -1; 172 } 173 174 ret = bdrv_pwrite(bs->file, s->crypto_header.offset + offset, buflen, buf, 175 0); 176 if (ret < 0) { 177 error_setg_errno(errp, -ret, "Could not read encryption header"); 178 return -1; 179 } 180 return 0; 181 } 182 183 static QDict* 184 qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp) 185 { 186 QDict *cryptoopts_qdict; 187 QDict *opts_qdict; 188 189 /* Extract "encrypt." options into a qdict */ 190 opts_qdict = qemu_opts_to_qdict(opts, NULL); 191 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); 192 qobject_unref(opts_qdict); 193 qdict_put_str(cryptoopts_qdict, "format", fmt); 194 return cryptoopts_qdict; 195 } 196 197 /* 198 * read qcow2 extension and fill bs 199 * start reading from start_offset 200 * finish reading upon magic of value 0 or when end_offset reached 201 * unknown magic is skipped (future extension this version knows nothing about) 202 * return 0 upon success, non-0 otherwise 203 */ 204 static int coroutine_fn GRAPH_RDLOCK 205 qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, 206 uint64_t end_offset, void **p_feature_table, 207 int flags, bool *need_update_header, Error **errp) 208 { 209 BDRVQcow2State *s = bs->opaque; 210 QCowExtension ext; 211 uint64_t offset; 212 int ret; 213 Qcow2BitmapHeaderExt bitmaps_ext; 214 215 if (need_update_header != NULL) { 216 *need_update_header = false; 217 } 218 219 #ifdef DEBUG_EXT 220 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); 221 #endif 222 offset = start_offset; 223 while (offset < end_offset) { 224 225 #ifdef DEBUG_EXT 226 /* Sanity check */ 227 if (offset > s->cluster_size) 228 printf("qcow2_read_extension: suspicious offset %lu\n", offset); 229 230 printf("attempting to read extended header in offset %lu\n", offset); 231 #endif 232 233 ret = bdrv_co_pread(bs->file, offset, sizeof(ext), &ext, 0); 234 if (ret < 0) { 235 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " 236 "pread fail from offset %" PRIu64, offset); 237 return 1; 238 } 239 ext.magic = be32_to_cpu(ext.magic); 240 ext.len = be32_to_cpu(ext.len); 241 offset += sizeof(ext); 242 #ifdef DEBUG_EXT 243 printf("ext.magic = 0x%x\n", ext.magic); 244 #endif 245 if (offset > end_offset || ext.len > end_offset - offset) { 246 error_setg(errp, "Header extension too large"); 247 return -EINVAL; 248 } 249 250 switch (ext.magic) { 251 case QCOW2_EXT_MAGIC_END: 252 return 0; 253 254 case QCOW2_EXT_MAGIC_BACKING_FORMAT: 255 if (ext.len >= sizeof(bs->backing_format)) { 256 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 257 " too large (>=%zu)", ext.len, 258 sizeof(bs->backing_format)); 259 return 2; 260 } 261 ret = bdrv_co_pread(bs->file, offset, ext.len, bs->backing_format, 0); 262 if (ret < 0) { 263 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " 264 "Could not read format name"); 265 return 3; 266 } 267 bs->backing_format[ext.len] = '\0'; 268 s->image_backing_format = g_strdup(bs->backing_format); 269 #ifdef DEBUG_EXT 270 printf("Qcow2: Got format extension %s\n", bs->backing_format); 271 #endif 272 break; 273 274 case QCOW2_EXT_MAGIC_FEATURE_TABLE: 275 if (p_feature_table != NULL) { 276 void *feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); 277 ret = bdrv_co_pread(bs->file, offset, ext.len, feature_table, 0); 278 if (ret < 0) { 279 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " 280 "Could not read table"); 281 g_free(feature_table); 282 return ret; 283 } 284 285 *p_feature_table = feature_table; 286 } 287 break; 288 289 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { 290 unsigned int cflags = 0; 291 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 292 error_setg(errp, "CRYPTO header extension only " 293 "expected with LUKS encryption method"); 294 return -EINVAL; 295 } 296 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { 297 error_setg(errp, "CRYPTO header extension size %u, " 298 "but expected size %zu", ext.len, 299 sizeof(Qcow2CryptoHeaderExtension)); 300 return -EINVAL; 301 } 302 303 ret = bdrv_co_pread(bs->file, offset, ext.len, &s->crypto_header, 0); 304 if (ret < 0) { 305 error_setg_errno(errp, -ret, 306 "Unable to read CRYPTO header extension"); 307 return ret; 308 } 309 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 310 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 311 312 if ((s->crypto_header.offset % s->cluster_size) != 0) { 313 error_setg(errp, "Encryption header offset '%" PRIu64 "' is " 314 "not a multiple of cluster size '%u'", 315 s->crypto_header.offset, s->cluster_size); 316 return -EINVAL; 317 } 318 319 if (flags & BDRV_O_NO_IO) { 320 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 321 } 322 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 323 qcow2_crypto_hdr_read_func, 324 bs, cflags, errp); 325 if (!s->crypto) { 326 return -EINVAL; 327 } 328 } break; 329 330 case QCOW2_EXT_MAGIC_BITMAPS: 331 if (ext.len != sizeof(bitmaps_ext)) { 332 error_setg_errno(errp, -ret, "bitmaps_ext: " 333 "Invalid extension length"); 334 return -EINVAL; 335 } 336 337 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { 338 if (s->qcow_version < 3) { 339 /* Let's be a bit more specific */ 340 warn_report("This qcow2 v2 image contains bitmaps, but " 341 "they may have been modified by a program " 342 "without persistent bitmap support; so now " 343 "they must all be considered inconsistent"); 344 } else { 345 warn_report("a program lacking bitmap support " 346 "modified this file, so all bitmaps are now " 347 "considered inconsistent"); 348 } 349 error_printf("Some clusters may be leaked, " 350 "run 'qemu-img check -r' on the image " 351 "file to fix."); 352 if (need_update_header != NULL) { 353 /* Updating is needed to drop invalid bitmap extension. */ 354 *need_update_header = true; 355 } 356 break; 357 } 358 359 ret = bdrv_co_pread(bs->file, offset, ext.len, &bitmaps_ext, 0); 360 if (ret < 0) { 361 error_setg_errno(errp, -ret, "bitmaps_ext: " 362 "Could not read ext header"); 363 return ret; 364 } 365 366 if (bitmaps_ext.reserved32 != 0) { 367 error_setg_errno(errp, -ret, "bitmaps_ext: " 368 "Reserved field is not zero"); 369 return -EINVAL; 370 } 371 372 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); 373 bitmaps_ext.bitmap_directory_size = 374 be64_to_cpu(bitmaps_ext.bitmap_directory_size); 375 bitmaps_ext.bitmap_directory_offset = 376 be64_to_cpu(bitmaps_ext.bitmap_directory_offset); 377 378 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { 379 error_setg(errp, 380 "bitmaps_ext: Image has %" PRIu32 " bitmaps, " 381 "exceeding the QEMU supported maximum of %d", 382 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); 383 return -EINVAL; 384 } 385 386 if (bitmaps_ext.nb_bitmaps == 0) { 387 error_setg(errp, "found bitmaps extension with zero bitmaps"); 388 return -EINVAL; 389 } 390 391 if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) { 392 error_setg(errp, "bitmaps_ext: " 393 "invalid bitmap directory offset"); 394 return -EINVAL; 395 } 396 397 if (bitmaps_ext.bitmap_directory_size > 398 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { 399 error_setg(errp, "bitmaps_ext: " 400 "bitmap directory size (%" PRIu64 ") exceeds " 401 "the maximum supported size (%d)", 402 bitmaps_ext.bitmap_directory_size, 403 QCOW2_MAX_BITMAP_DIRECTORY_SIZE); 404 return -EINVAL; 405 } 406 407 s->nb_bitmaps = bitmaps_ext.nb_bitmaps; 408 s->bitmap_directory_offset = 409 bitmaps_ext.bitmap_directory_offset; 410 s->bitmap_directory_size = 411 bitmaps_ext.bitmap_directory_size; 412 413 #ifdef DEBUG_EXT 414 printf("Qcow2: Got bitmaps extension: " 415 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", 416 s->bitmap_directory_offset, s->nb_bitmaps); 417 #endif 418 break; 419 420 case QCOW2_EXT_MAGIC_DATA_FILE: 421 { 422 s->image_data_file = g_malloc0(ext.len + 1); 423 ret = bdrv_co_pread(bs->file, offset, ext.len, s->image_data_file, 0); 424 if (ret < 0) { 425 error_setg_errno(errp, -ret, 426 "ERROR: Could not read data file name"); 427 return ret; 428 } 429 #ifdef DEBUG_EXT 430 printf("Qcow2: Got external data file %s\n", s->image_data_file); 431 #endif 432 break; 433 } 434 435 default: 436 /* unknown magic - save it in case we need to rewrite the header */ 437 /* If you add a new feature, make sure to also update the fast 438 * path of qcow2_make_empty() to deal with it. */ 439 { 440 Qcow2UnknownHeaderExtension *uext; 441 442 uext = g_malloc0(sizeof(*uext) + ext.len); 443 uext->magic = ext.magic; 444 uext->len = ext.len; 445 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); 446 447 ret = bdrv_co_pread(bs->file, offset, uext->len, uext->data, 0); 448 if (ret < 0) { 449 error_setg_errno(errp, -ret, "ERROR: unknown extension: " 450 "Could not read data"); 451 return ret; 452 } 453 } 454 break; 455 } 456 457 offset += ((ext.len + 7) & ~7); 458 } 459 460 return 0; 461 } 462 463 static void cleanup_unknown_header_ext(BlockDriverState *bs) 464 { 465 BDRVQcow2State *s = bs->opaque; 466 Qcow2UnknownHeaderExtension *uext, *next; 467 468 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { 469 QLIST_REMOVE(uext, next); 470 g_free(uext); 471 } 472 } 473 474 static void report_unsupported_feature(Error **errp, Qcow2Feature *table, 475 uint64_t mask) 476 { 477 g_autoptr(GString) features = g_string_sized_new(60); 478 479 while (table && table->name[0] != '\0') { 480 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { 481 if (mask & (1ULL << table->bit)) { 482 if (features->len > 0) { 483 g_string_append(features, ", "); 484 } 485 g_string_append_printf(features, "%.46s", table->name); 486 mask &= ~(1ULL << table->bit); 487 } 488 } 489 table++; 490 } 491 492 if (mask) { 493 if (features->len > 0) { 494 g_string_append(features, ", "); 495 } 496 g_string_append_printf(features, 497 "Unknown incompatible feature: %" PRIx64, mask); 498 } 499 500 error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); 501 } 502 503 /* 504 * Sets the dirty bit and flushes afterwards if necessary. 505 * 506 * The incompatible_features bit is only set if the image file header was 507 * updated successfully. Therefore it is not required to check the return 508 * value of this function. 509 */ 510 int qcow2_mark_dirty(BlockDriverState *bs) 511 { 512 BDRVQcow2State *s = bs->opaque; 513 uint64_t val; 514 int ret; 515 516 assert(s->qcow_version >= 3); 517 518 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 519 return 0; /* already dirty */ 520 } 521 522 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); 523 ret = bdrv_pwrite_sync(bs->file, 524 offsetof(QCowHeader, incompatible_features), 525 sizeof(val), &val, 0); 526 if (ret < 0) { 527 return ret; 528 } 529 530 /* Only treat image as dirty if the header was updated successfully */ 531 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; 532 return 0; 533 } 534 535 /* 536 * Clears the dirty bit and flushes before if necessary. Only call this 537 * function when there are no pending requests, it does not guard against 538 * concurrent requests dirtying the image. 539 */ 540 static int GRAPH_RDLOCK qcow2_mark_clean(BlockDriverState *bs) 541 { 542 BDRVQcow2State *s = bs->opaque; 543 544 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 545 int ret; 546 547 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; 548 549 ret = qcow2_flush_caches(bs); 550 if (ret < 0) { 551 return ret; 552 } 553 554 return qcow2_update_header(bs); 555 } 556 return 0; 557 } 558 559 /* 560 * Marks the image as corrupt. 561 */ 562 int qcow2_mark_corrupt(BlockDriverState *bs) 563 { 564 BDRVQcow2State *s = bs->opaque; 565 566 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; 567 return qcow2_update_header(bs); 568 } 569 570 /* 571 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes 572 * before if necessary. 573 */ 574 static int coroutine_fn GRAPH_RDLOCK 575 qcow2_mark_consistent(BlockDriverState *bs) 576 { 577 BDRVQcow2State *s = bs->opaque; 578 579 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 580 int ret = qcow2_flush_caches(bs); 581 if (ret < 0) { 582 return ret; 583 } 584 585 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; 586 return qcow2_update_header(bs); 587 } 588 return 0; 589 } 590 591 static void qcow2_add_check_result(BdrvCheckResult *out, 592 const BdrvCheckResult *src, 593 bool set_allocation_info) 594 { 595 out->corruptions += src->corruptions; 596 out->leaks += src->leaks; 597 out->check_errors += src->check_errors; 598 out->corruptions_fixed += src->corruptions_fixed; 599 out->leaks_fixed += src->leaks_fixed; 600 601 if (set_allocation_info) { 602 out->image_end_offset = src->image_end_offset; 603 out->bfi = src->bfi; 604 } 605 } 606 607 static int coroutine_fn GRAPH_RDLOCK 608 qcow2_co_check_locked(BlockDriverState *bs, BdrvCheckResult *result, 609 BdrvCheckMode fix) 610 { 611 BdrvCheckResult snapshot_res = {}; 612 BdrvCheckResult refcount_res = {}; 613 int ret; 614 615 memset(result, 0, sizeof(*result)); 616 617 ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix); 618 if (ret < 0) { 619 qcow2_add_check_result(result, &snapshot_res, false); 620 return ret; 621 } 622 623 ret = qcow2_check_refcounts(bs, &refcount_res, fix); 624 qcow2_add_check_result(result, &refcount_res, true); 625 if (ret < 0) { 626 qcow2_add_check_result(result, &snapshot_res, false); 627 return ret; 628 } 629 630 ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix); 631 qcow2_add_check_result(result, &snapshot_res, false); 632 if (ret < 0) { 633 return ret; 634 } 635 636 if (fix && result->check_errors == 0 && result->corruptions == 0) { 637 ret = qcow2_mark_clean(bs); 638 if (ret < 0) { 639 return ret; 640 } 641 return qcow2_mark_consistent(bs); 642 } 643 return ret; 644 } 645 646 static int coroutine_fn GRAPH_RDLOCK 647 qcow2_co_check(BlockDriverState *bs, BdrvCheckResult *result, 648 BdrvCheckMode fix) 649 { 650 BDRVQcow2State *s = bs->opaque; 651 int ret; 652 653 qemu_co_mutex_lock(&s->lock); 654 ret = qcow2_co_check_locked(bs, result, fix); 655 qemu_co_mutex_unlock(&s->lock); 656 return ret; 657 } 658 659 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 660 uint64_t entries, size_t entry_len, 661 int64_t max_size_bytes, const char *table_name, 662 Error **errp) 663 { 664 BDRVQcow2State *s = bs->opaque; 665 666 if (entries > max_size_bytes / entry_len) { 667 error_setg(errp, "%s too large", table_name); 668 return -EFBIG; 669 } 670 671 /* Use signed INT64_MAX as the maximum even for uint64_t header fields, 672 * because values will be passed to qemu functions taking int64_t. */ 673 if ((INT64_MAX - entries * entry_len < offset) || 674 (offset_into_cluster(s, offset) != 0)) { 675 error_setg(errp, "%s offset invalid", table_name); 676 return -EINVAL; 677 } 678 679 return 0; 680 } 681 682 static const char *const mutable_opts[] = { 683 QCOW2_OPT_LAZY_REFCOUNTS, 684 QCOW2_OPT_DISCARD_REQUEST, 685 QCOW2_OPT_DISCARD_SNAPSHOT, 686 QCOW2_OPT_DISCARD_OTHER, 687 QCOW2_OPT_DISCARD_NO_UNREF, 688 QCOW2_OPT_OVERLAP, 689 QCOW2_OPT_OVERLAP_TEMPLATE, 690 QCOW2_OPT_OVERLAP_MAIN_HEADER, 691 QCOW2_OPT_OVERLAP_ACTIVE_L1, 692 QCOW2_OPT_OVERLAP_ACTIVE_L2, 693 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 694 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 695 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 696 QCOW2_OPT_OVERLAP_INACTIVE_L1, 697 QCOW2_OPT_OVERLAP_INACTIVE_L2, 698 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 699 QCOW2_OPT_CACHE_SIZE, 700 QCOW2_OPT_L2_CACHE_SIZE, 701 QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 702 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 703 QCOW2_OPT_CACHE_CLEAN_INTERVAL, 704 NULL 705 }; 706 707 static QemuOptsList qcow2_runtime_opts = { 708 .name = "qcow2", 709 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), 710 .desc = { 711 { 712 .name = QCOW2_OPT_LAZY_REFCOUNTS, 713 .type = QEMU_OPT_BOOL, 714 .help = "Postpone refcount updates", 715 }, 716 { 717 .name = QCOW2_OPT_DISCARD_REQUEST, 718 .type = QEMU_OPT_BOOL, 719 .help = "Pass guest discard requests to the layer below", 720 }, 721 { 722 .name = QCOW2_OPT_DISCARD_SNAPSHOT, 723 .type = QEMU_OPT_BOOL, 724 .help = "Generate discard requests when snapshot related space " 725 "is freed", 726 }, 727 { 728 .name = QCOW2_OPT_DISCARD_OTHER, 729 .type = QEMU_OPT_BOOL, 730 .help = "Generate discard requests when other clusters are freed", 731 }, 732 { 733 .name = QCOW2_OPT_DISCARD_NO_UNREF, 734 .type = QEMU_OPT_BOOL, 735 .help = "Do not unreference discarded clusters", 736 }, 737 { 738 .name = QCOW2_OPT_OVERLAP, 739 .type = QEMU_OPT_STRING, 740 .help = "Selects which overlap checks to perform from a range of " 741 "templates (none, constant, cached, all)", 742 }, 743 { 744 .name = QCOW2_OPT_OVERLAP_TEMPLATE, 745 .type = QEMU_OPT_STRING, 746 .help = "Selects which overlap checks to perform from a range of " 747 "templates (none, constant, cached, all)", 748 }, 749 { 750 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, 751 .type = QEMU_OPT_BOOL, 752 .help = "Check for unintended writes into the main qcow2 header", 753 }, 754 { 755 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, 756 .type = QEMU_OPT_BOOL, 757 .help = "Check for unintended writes into the active L1 table", 758 }, 759 { 760 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, 761 .type = QEMU_OPT_BOOL, 762 .help = "Check for unintended writes into an active L2 table", 763 }, 764 { 765 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 766 .type = QEMU_OPT_BOOL, 767 .help = "Check for unintended writes into the refcount table", 768 }, 769 { 770 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 771 .type = QEMU_OPT_BOOL, 772 .help = "Check for unintended writes into a refcount block", 773 }, 774 { 775 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 776 .type = QEMU_OPT_BOOL, 777 .help = "Check for unintended writes into the snapshot table", 778 }, 779 { 780 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, 781 .type = QEMU_OPT_BOOL, 782 .help = "Check for unintended writes into an inactive L1 table", 783 }, 784 { 785 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, 786 .type = QEMU_OPT_BOOL, 787 .help = "Check for unintended writes into an inactive L2 table", 788 }, 789 { 790 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 791 .type = QEMU_OPT_BOOL, 792 .help = "Check for unintended writes into the bitmap directory", 793 }, 794 { 795 .name = QCOW2_OPT_CACHE_SIZE, 796 .type = QEMU_OPT_SIZE, 797 .help = "Maximum combined metadata (L2 tables and refcount blocks) " 798 "cache size", 799 }, 800 { 801 .name = QCOW2_OPT_L2_CACHE_SIZE, 802 .type = QEMU_OPT_SIZE, 803 .help = "Maximum L2 table cache size", 804 }, 805 { 806 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 807 .type = QEMU_OPT_SIZE, 808 .help = "Size of each entry in the L2 cache", 809 }, 810 { 811 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, 812 .type = QEMU_OPT_SIZE, 813 .help = "Maximum refcount block cache size", 814 }, 815 { 816 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, 817 .type = QEMU_OPT_NUMBER, 818 .help = "Clean unused cache entries after this time (in seconds)", 819 }, 820 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 821 "ID of secret providing qcow2 AES key or LUKS passphrase"), 822 { /* end of list */ } 823 }, 824 }; 825 826 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { 827 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, 828 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, 829 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, 830 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 831 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 832 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 833 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, 834 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, 835 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 836 }; 837 838 static void cache_clean_timer_cb(void *opaque) 839 { 840 BlockDriverState *bs = opaque; 841 BDRVQcow2State *s = bs->opaque; 842 qcow2_cache_clean_unused(s->l2_table_cache); 843 qcow2_cache_clean_unused(s->refcount_block_cache); 844 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 845 (int64_t) s->cache_clean_interval * 1000); 846 } 847 848 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) 849 { 850 BDRVQcow2State *s = bs->opaque; 851 if (s->cache_clean_interval > 0) { 852 s->cache_clean_timer = 853 aio_timer_new_with_attrs(context, QEMU_CLOCK_VIRTUAL, 854 SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL, 855 cache_clean_timer_cb, bs); 856 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 857 (int64_t) s->cache_clean_interval * 1000); 858 } 859 } 860 861 static void cache_clean_timer_del(BlockDriverState *bs) 862 { 863 BDRVQcow2State *s = bs->opaque; 864 if (s->cache_clean_timer) { 865 timer_free(s->cache_clean_timer); 866 s->cache_clean_timer = NULL; 867 } 868 } 869 870 static void qcow2_detach_aio_context(BlockDriverState *bs) 871 { 872 cache_clean_timer_del(bs); 873 } 874 875 static void qcow2_attach_aio_context(BlockDriverState *bs, 876 AioContext *new_context) 877 { 878 cache_clean_timer_init(bs, new_context); 879 } 880 881 static bool read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, 882 uint64_t *l2_cache_size, 883 uint64_t *l2_cache_entry_size, 884 uint64_t *refcount_cache_size, Error **errp) 885 { 886 BDRVQcow2State *s = bs->opaque; 887 uint64_t combined_cache_size, l2_cache_max_setting; 888 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; 889 bool l2_cache_entry_size_set; 890 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; 891 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; 892 uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); 893 /* An L2 table is always one cluster in size so the max cache size 894 * should be a multiple of the cluster size. */ 895 uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s), 896 s->cluster_size); 897 898 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); 899 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); 900 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 901 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); 902 903 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); 904 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 905 DEFAULT_L2_CACHE_MAX_SIZE); 906 *refcount_cache_size = qemu_opt_get_size(opts, 907 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); 908 909 *l2_cache_entry_size = qemu_opt_get_size( 910 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); 911 912 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); 913 914 if (combined_cache_size_set) { 915 if (l2_cache_size_set && refcount_cache_size_set) { 916 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE 917 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " 918 "at the same time"); 919 return false; 920 } else if (l2_cache_size_set && 921 (l2_cache_max_setting > combined_cache_size)) { 922 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " 923 QCOW2_OPT_CACHE_SIZE); 924 return false; 925 } else if (*refcount_cache_size > combined_cache_size) { 926 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " 927 QCOW2_OPT_CACHE_SIZE); 928 return false; 929 } 930 931 if (l2_cache_size_set) { 932 *refcount_cache_size = combined_cache_size - *l2_cache_size; 933 } else if (refcount_cache_size_set) { 934 *l2_cache_size = combined_cache_size - *refcount_cache_size; 935 } else { 936 /* Assign as much memory as possible to the L2 cache, and 937 * use the remainder for the refcount cache */ 938 if (combined_cache_size >= max_l2_cache + min_refcount_cache) { 939 *l2_cache_size = max_l2_cache; 940 *refcount_cache_size = combined_cache_size - *l2_cache_size; 941 } else { 942 *refcount_cache_size = 943 MIN(combined_cache_size, min_refcount_cache); 944 *l2_cache_size = combined_cache_size - *refcount_cache_size; 945 } 946 } 947 } 948 949 /* 950 * If the L2 cache is not enough to cover the whole disk then 951 * default to 4KB entries. Smaller entries reduce the cost of 952 * loads and evictions and increase I/O performance. 953 */ 954 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { 955 *l2_cache_entry_size = MIN(s->cluster_size, 4096); 956 } 957 958 /* l2_cache_size and refcount_cache_size are ensured to have at least 959 * their minimum values in qcow2_update_options_prepare() */ 960 961 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || 962 *l2_cache_entry_size > s->cluster_size || 963 !is_power_of_2(*l2_cache_entry_size)) { 964 error_setg(errp, "L2 cache entry size must be a power of two " 965 "between %d and the cluster size (%d)", 966 1 << MIN_CLUSTER_BITS, s->cluster_size); 967 return false; 968 } 969 970 return true; 971 } 972 973 typedef struct Qcow2ReopenState { 974 Qcow2Cache *l2_table_cache; 975 Qcow2Cache *refcount_block_cache; 976 int l2_slice_size; /* Number of entries in a slice of the L2 table */ 977 bool use_lazy_refcounts; 978 int overlap_check; 979 bool discard_passthrough[QCOW2_DISCARD_MAX]; 980 bool discard_no_unref; 981 uint64_t cache_clean_interval; 982 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 983 } Qcow2ReopenState; 984 985 static int GRAPH_RDLOCK 986 qcow2_update_options_prepare(BlockDriverState *bs, Qcow2ReopenState *r, 987 QDict *options, int flags, Error **errp) 988 { 989 BDRVQcow2State *s = bs->opaque; 990 QemuOpts *opts = NULL; 991 const char *opt_overlap_check, *opt_overlap_check_template; 992 int overlap_check_template = 0; 993 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; 994 int i; 995 const char *encryptfmt; 996 QDict *encryptopts = NULL; 997 int ret; 998 999 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 1000 encryptfmt = qdict_get_try_str(encryptopts, "format"); 1001 1002 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); 1003 if (!qemu_opts_absorb_qdict(opts, options, errp)) { 1004 ret = -EINVAL; 1005 goto fail; 1006 } 1007 1008 /* get L2 table/refcount block cache size from command line options */ 1009 if (!read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, 1010 &refcount_cache_size, errp)) { 1011 ret = -EINVAL; 1012 goto fail; 1013 } 1014 1015 l2_cache_size /= l2_cache_entry_size; 1016 if (l2_cache_size < MIN_L2_CACHE_SIZE) { 1017 l2_cache_size = MIN_L2_CACHE_SIZE; 1018 } 1019 if (l2_cache_size > INT_MAX) { 1020 error_setg(errp, "L2 cache size too big"); 1021 ret = -EINVAL; 1022 goto fail; 1023 } 1024 1025 refcount_cache_size /= s->cluster_size; 1026 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { 1027 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; 1028 } 1029 if (refcount_cache_size > INT_MAX) { 1030 error_setg(errp, "Refcount cache size too big"); 1031 ret = -EINVAL; 1032 goto fail; 1033 } 1034 1035 /* alloc new L2 table/refcount block cache, flush old one */ 1036 if (s->l2_table_cache) { 1037 ret = qcow2_cache_flush(bs, s->l2_table_cache); 1038 if (ret) { 1039 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); 1040 goto fail; 1041 } 1042 } 1043 1044 if (s->refcount_block_cache) { 1045 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 1046 if (ret) { 1047 error_setg_errno(errp, -ret, 1048 "Failed to flush the refcount block cache"); 1049 goto fail; 1050 } 1051 } 1052 1053 r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s); 1054 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, 1055 l2_cache_entry_size); 1056 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, 1057 s->cluster_size); 1058 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { 1059 error_setg(errp, "Could not allocate metadata caches"); 1060 ret = -ENOMEM; 1061 goto fail; 1062 } 1063 1064 /* New interval for cache cleanup timer */ 1065 r->cache_clean_interval = 1066 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 1067 DEFAULT_CACHE_CLEAN_INTERVAL); 1068 #ifndef CONFIG_LINUX 1069 if (r->cache_clean_interval != 0) { 1070 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL 1071 " not supported on this host"); 1072 ret = -EINVAL; 1073 goto fail; 1074 } 1075 #endif 1076 if (r->cache_clean_interval > UINT_MAX) { 1077 error_setg(errp, "Cache clean interval too big"); 1078 ret = -EINVAL; 1079 goto fail; 1080 } 1081 1082 /* lazy-refcounts; flush if going from enabled to disabled */ 1083 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, 1084 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); 1085 if (r->use_lazy_refcounts && s->qcow_version < 3) { 1086 error_setg(errp, "Lazy refcounts require a qcow2 image with at least " 1087 "qemu 1.1 compatibility level"); 1088 ret = -EINVAL; 1089 goto fail; 1090 } 1091 1092 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { 1093 ret = qcow2_mark_clean(bs); 1094 if (ret < 0) { 1095 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); 1096 goto fail; 1097 } 1098 } 1099 1100 /* Overlap check options */ 1101 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); 1102 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); 1103 if (opt_overlap_check_template && opt_overlap_check && 1104 strcmp(opt_overlap_check_template, opt_overlap_check)) 1105 { 1106 error_setg(errp, "Conflicting values for qcow2 options '" 1107 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE 1108 "' ('%s')", opt_overlap_check, opt_overlap_check_template); 1109 ret = -EINVAL; 1110 goto fail; 1111 } 1112 if (!opt_overlap_check) { 1113 opt_overlap_check = opt_overlap_check_template ?: "cached"; 1114 } 1115 1116 if (!strcmp(opt_overlap_check, "none")) { 1117 overlap_check_template = 0; 1118 } else if (!strcmp(opt_overlap_check, "constant")) { 1119 overlap_check_template = QCOW2_OL_CONSTANT; 1120 } else if (!strcmp(opt_overlap_check, "cached")) { 1121 overlap_check_template = QCOW2_OL_CACHED; 1122 } else if (!strcmp(opt_overlap_check, "all")) { 1123 overlap_check_template = QCOW2_OL_ALL; 1124 } else { 1125 error_setg(errp, "Unsupported value '%s' for qcow2 option " 1126 "'overlap-check'. Allowed are any of the following: " 1127 "none, constant, cached, all", opt_overlap_check); 1128 ret = -EINVAL; 1129 goto fail; 1130 } 1131 1132 r->overlap_check = 0; 1133 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { 1134 /* overlap-check defines a template bitmask, but every flag may be 1135 * overwritten through the associated boolean option */ 1136 r->overlap_check |= 1137 qemu_opt_get_bool(opts, overlap_bool_option_names[i], 1138 overlap_check_template & (1 << i)) << i; 1139 } 1140 1141 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; 1142 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; 1143 r->discard_passthrough[QCOW2_DISCARD_REQUEST] = 1144 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, 1145 flags & BDRV_O_UNMAP); 1146 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = 1147 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); 1148 r->discard_passthrough[QCOW2_DISCARD_OTHER] = 1149 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); 1150 1151 r->discard_no_unref = qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_NO_UNREF, 1152 false); 1153 if (r->discard_no_unref && s->qcow_version < 3) { 1154 error_setg(errp, 1155 "discard-no-unref is only supported since qcow2 version 3"); 1156 ret = -EINVAL; 1157 goto fail; 1158 } 1159 1160 switch (s->crypt_method_header) { 1161 case QCOW_CRYPT_NONE: 1162 if (encryptfmt) { 1163 error_setg(errp, "No encryption in image header, but options " 1164 "specified format '%s'", encryptfmt); 1165 ret = -EINVAL; 1166 goto fail; 1167 } 1168 break; 1169 1170 case QCOW_CRYPT_AES: 1171 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 1172 error_setg(errp, 1173 "Header reported 'aes' encryption format but " 1174 "options specify '%s'", encryptfmt); 1175 ret = -EINVAL; 1176 goto fail; 1177 } 1178 qdict_put_str(encryptopts, "format", "qcow"); 1179 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1180 if (!r->crypto_opts) { 1181 ret = -EINVAL; 1182 goto fail; 1183 } 1184 break; 1185 1186 case QCOW_CRYPT_LUKS: 1187 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { 1188 error_setg(errp, 1189 "Header reported 'luks' encryption format but " 1190 "options specify '%s'", encryptfmt); 1191 ret = -EINVAL; 1192 goto fail; 1193 } 1194 qdict_put_str(encryptopts, "format", "luks"); 1195 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1196 if (!r->crypto_opts) { 1197 ret = -EINVAL; 1198 goto fail; 1199 } 1200 break; 1201 1202 default: 1203 error_setg(errp, "Unsupported encryption method %d", 1204 s->crypt_method_header); 1205 ret = -EINVAL; 1206 goto fail; 1207 } 1208 1209 ret = 0; 1210 fail: 1211 qobject_unref(encryptopts); 1212 qemu_opts_del(opts); 1213 opts = NULL; 1214 return ret; 1215 } 1216 1217 static void qcow2_update_options_commit(BlockDriverState *bs, 1218 Qcow2ReopenState *r) 1219 { 1220 BDRVQcow2State *s = bs->opaque; 1221 int i; 1222 1223 if (s->l2_table_cache) { 1224 qcow2_cache_destroy(s->l2_table_cache); 1225 } 1226 if (s->refcount_block_cache) { 1227 qcow2_cache_destroy(s->refcount_block_cache); 1228 } 1229 s->l2_table_cache = r->l2_table_cache; 1230 s->refcount_block_cache = r->refcount_block_cache; 1231 s->l2_slice_size = r->l2_slice_size; 1232 1233 s->overlap_check = r->overlap_check; 1234 s->use_lazy_refcounts = r->use_lazy_refcounts; 1235 1236 for (i = 0; i < QCOW2_DISCARD_MAX; i++) { 1237 s->discard_passthrough[i] = r->discard_passthrough[i]; 1238 } 1239 1240 s->discard_no_unref = r->discard_no_unref; 1241 1242 if (s->cache_clean_interval != r->cache_clean_interval) { 1243 cache_clean_timer_del(bs); 1244 s->cache_clean_interval = r->cache_clean_interval; 1245 cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); 1246 } 1247 1248 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1249 s->crypto_opts = r->crypto_opts; 1250 } 1251 1252 static void qcow2_update_options_abort(BlockDriverState *bs, 1253 Qcow2ReopenState *r) 1254 { 1255 if (r->l2_table_cache) { 1256 qcow2_cache_destroy(r->l2_table_cache); 1257 } 1258 if (r->refcount_block_cache) { 1259 qcow2_cache_destroy(r->refcount_block_cache); 1260 } 1261 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); 1262 } 1263 1264 static int coroutine_fn GRAPH_RDLOCK 1265 qcow2_update_options(BlockDriverState *bs, QDict *options, int flags, 1266 Error **errp) 1267 { 1268 Qcow2ReopenState r = {}; 1269 int ret; 1270 1271 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); 1272 if (ret >= 0) { 1273 qcow2_update_options_commit(bs, &r); 1274 } else { 1275 qcow2_update_options_abort(bs, &r); 1276 } 1277 1278 return ret; 1279 } 1280 1281 static int validate_compression_type(BDRVQcow2State *s, Error **errp) 1282 { 1283 switch (s->compression_type) { 1284 case QCOW2_COMPRESSION_TYPE_ZLIB: 1285 #ifdef CONFIG_ZSTD 1286 case QCOW2_COMPRESSION_TYPE_ZSTD: 1287 #endif 1288 break; 1289 1290 default: 1291 error_setg(errp, "qcow2: unknown compression type: %u", 1292 s->compression_type); 1293 return -ENOTSUP; 1294 } 1295 1296 /* 1297 * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB 1298 * the incompatible feature flag must be set 1299 */ 1300 if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) { 1301 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 1302 error_setg(errp, "qcow2: Compression type incompatible feature " 1303 "bit must not be set"); 1304 return -EINVAL; 1305 } 1306 } else { 1307 if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) { 1308 error_setg(errp, "qcow2: Compression type incompatible feature " 1309 "bit must be set"); 1310 return -EINVAL; 1311 } 1312 } 1313 1314 return 0; 1315 } 1316 1317 /* Called with s->lock held. */ 1318 static int coroutine_fn GRAPH_RDLOCK 1319 qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, 1320 bool open_data_file, Error **errp) 1321 { 1322 ERRP_GUARD(); 1323 BDRVQcow2State *s = bs->opaque; 1324 unsigned int len, i; 1325 int ret = 0; 1326 QCowHeader header; 1327 uint64_t ext_end; 1328 uint64_t l1_vm_state_index; 1329 bool update_header = false; 1330 1331 ret = bdrv_co_pread(bs->file, 0, sizeof(header), &header, 0); 1332 if (ret < 0) { 1333 error_setg_errno(errp, -ret, "Could not read qcow2 header"); 1334 goto fail; 1335 } 1336 header.magic = be32_to_cpu(header.magic); 1337 header.version = be32_to_cpu(header.version); 1338 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 1339 header.backing_file_size = be32_to_cpu(header.backing_file_size); 1340 header.size = be64_to_cpu(header.size); 1341 header.cluster_bits = be32_to_cpu(header.cluster_bits); 1342 header.crypt_method = be32_to_cpu(header.crypt_method); 1343 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 1344 header.l1_size = be32_to_cpu(header.l1_size); 1345 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); 1346 header.refcount_table_clusters = 1347 be32_to_cpu(header.refcount_table_clusters); 1348 header.snapshots_offset = be64_to_cpu(header.snapshots_offset); 1349 header.nb_snapshots = be32_to_cpu(header.nb_snapshots); 1350 1351 if (header.magic != QCOW_MAGIC) { 1352 error_setg(errp, "Image is not in qcow2 format"); 1353 ret = -EINVAL; 1354 goto fail; 1355 } 1356 if (header.version < 2 || header.version > 3) { 1357 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); 1358 ret = -ENOTSUP; 1359 goto fail; 1360 } 1361 1362 s->qcow_version = header.version; 1363 1364 /* Initialise cluster size */ 1365 if (header.cluster_bits < MIN_CLUSTER_BITS || 1366 header.cluster_bits > MAX_CLUSTER_BITS) { 1367 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, 1368 header.cluster_bits); 1369 ret = -EINVAL; 1370 goto fail; 1371 } 1372 1373 s->cluster_bits = header.cluster_bits; 1374 s->cluster_size = 1 << s->cluster_bits; 1375 1376 /* Initialise version 3 header fields */ 1377 if (header.version == 2) { 1378 header.incompatible_features = 0; 1379 header.compatible_features = 0; 1380 header.autoclear_features = 0; 1381 header.refcount_order = 4; 1382 header.header_length = 72; 1383 } else { 1384 header.incompatible_features = 1385 be64_to_cpu(header.incompatible_features); 1386 header.compatible_features = be64_to_cpu(header.compatible_features); 1387 header.autoclear_features = be64_to_cpu(header.autoclear_features); 1388 header.refcount_order = be32_to_cpu(header.refcount_order); 1389 header.header_length = be32_to_cpu(header.header_length); 1390 1391 if (header.header_length < 104) { 1392 error_setg(errp, "qcow2 header too short"); 1393 ret = -EINVAL; 1394 goto fail; 1395 } 1396 } 1397 1398 if (header.header_length > s->cluster_size) { 1399 error_setg(errp, "qcow2 header exceeds cluster size"); 1400 ret = -EINVAL; 1401 goto fail; 1402 } 1403 1404 if (header.header_length > sizeof(header)) { 1405 s->unknown_header_fields_size = header.header_length - sizeof(header); 1406 s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); 1407 ret = bdrv_co_pread(bs->file, sizeof(header), 1408 s->unknown_header_fields_size, 1409 s->unknown_header_fields, 0); 1410 if (ret < 0) { 1411 error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " 1412 "fields"); 1413 goto fail; 1414 } 1415 } 1416 1417 if (header.backing_file_offset > s->cluster_size) { 1418 error_setg(errp, "Invalid backing file offset"); 1419 ret = -EINVAL; 1420 goto fail; 1421 } 1422 1423 if (header.backing_file_offset) { 1424 ext_end = header.backing_file_offset; 1425 } else { 1426 ext_end = 1 << header.cluster_bits; 1427 } 1428 1429 /* Handle feature bits */ 1430 s->incompatible_features = header.incompatible_features; 1431 s->compatible_features = header.compatible_features; 1432 s->autoclear_features = header.autoclear_features; 1433 1434 /* 1435 * Handle compression type 1436 * Older qcow2 images don't contain the compression type header. 1437 * Distinguish them by the header length and use 1438 * the only valid (default) compression type in that case 1439 */ 1440 if (header.header_length > offsetof(QCowHeader, compression_type)) { 1441 s->compression_type = header.compression_type; 1442 } else { 1443 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 1444 } 1445 1446 ret = validate_compression_type(s, errp); 1447 if (ret) { 1448 goto fail; 1449 } 1450 1451 if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { 1452 void *feature_table = NULL; 1453 qcow2_read_extensions(bs, header.header_length, ext_end, 1454 &feature_table, flags, NULL, NULL); 1455 report_unsupported_feature(errp, feature_table, 1456 s->incompatible_features & 1457 ~QCOW2_INCOMPAT_MASK); 1458 ret = -ENOTSUP; 1459 g_free(feature_table); 1460 goto fail; 1461 } 1462 1463 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 1464 /* Corrupt images may not be written to unless they are being repaired 1465 */ 1466 if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { 1467 error_setg(errp, "qcow2: Image is corrupt; cannot be opened " 1468 "read/write"); 1469 ret = -EACCES; 1470 goto fail; 1471 } 1472 } 1473 1474 s->subclusters_per_cluster = 1475 has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1; 1476 s->subcluster_size = s->cluster_size / s->subclusters_per_cluster; 1477 s->subcluster_bits = ctz32(s->subcluster_size); 1478 1479 if (s->subcluster_size < (1 << MIN_CLUSTER_BITS)) { 1480 error_setg(errp, "Unsupported subcluster size: %d", s->subcluster_size); 1481 ret = -EINVAL; 1482 goto fail; 1483 } 1484 1485 /* Check support for various header values */ 1486 if (header.refcount_order > 6) { 1487 error_setg(errp, "Reference count entry width too large; may not " 1488 "exceed 64 bits"); 1489 ret = -EINVAL; 1490 goto fail; 1491 } 1492 s->refcount_order = header.refcount_order; 1493 s->refcount_bits = 1 << s->refcount_order; 1494 s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); 1495 s->refcount_max += s->refcount_max - 1; 1496 1497 s->crypt_method_header = header.crypt_method; 1498 if (s->crypt_method_header) { 1499 if (bdrv_uses_whitelist() && 1500 s->crypt_method_header == QCOW_CRYPT_AES) { 1501 error_setg(errp, 1502 "Use of AES-CBC encrypted qcow2 images is no longer " 1503 "supported in system emulators"); 1504 error_append_hint(errp, 1505 "You can use 'qemu-img convert' to convert your " 1506 "image to an alternative supported format, such " 1507 "as unencrypted qcow2, or raw with the LUKS " 1508 "format instead.\n"); 1509 ret = -ENOSYS; 1510 goto fail; 1511 } 1512 1513 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1514 s->crypt_physical_offset = false; 1515 } else { 1516 /* Assuming LUKS and any future crypt methods we 1517 * add will all use physical offsets, due to the 1518 * fact that the alternative is insecure... */ 1519 s->crypt_physical_offset = true; 1520 } 1521 1522 bs->encrypted = true; 1523 } 1524 1525 s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s)); 1526 s->l2_size = 1 << s->l2_bits; 1527 /* 2^(s->refcount_order - 3) is the refcount width in bytes */ 1528 s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); 1529 s->refcount_block_size = 1 << s->refcount_block_bits; 1530 bs->total_sectors = header.size / BDRV_SECTOR_SIZE; 1531 s->csize_shift = (62 - (s->cluster_bits - 8)); 1532 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; 1533 s->cluster_offset_mask = (1LL << s->csize_shift) - 1; 1534 1535 s->refcount_table_offset = header.refcount_table_offset; 1536 s->refcount_table_size = 1537 header.refcount_table_clusters << (s->cluster_bits - 3); 1538 1539 if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { 1540 error_setg(errp, "Image does not contain a reference count table"); 1541 ret = -EINVAL; 1542 goto fail; 1543 } 1544 1545 ret = qcow2_validate_table(bs, s->refcount_table_offset, 1546 header.refcount_table_clusters, 1547 s->cluster_size, QCOW_MAX_REFTABLE_SIZE, 1548 "Reference count table", errp); 1549 if (ret < 0) { 1550 goto fail; 1551 } 1552 1553 if (!(flags & BDRV_O_CHECK)) { 1554 /* 1555 * The total size in bytes of the snapshot table is checked in 1556 * qcow2_read_snapshots() because the size of each snapshot is 1557 * variable and we don't know it yet. 1558 * Here we only check the offset and number of snapshots. 1559 */ 1560 ret = qcow2_validate_table(bs, header.snapshots_offset, 1561 header.nb_snapshots, 1562 sizeof(QCowSnapshotHeader), 1563 sizeof(QCowSnapshotHeader) * 1564 QCOW_MAX_SNAPSHOTS, 1565 "Snapshot table", errp); 1566 if (ret < 0) { 1567 goto fail; 1568 } 1569 } 1570 1571 /* read the level 1 table */ 1572 ret = qcow2_validate_table(bs, header.l1_table_offset, 1573 header.l1_size, L1E_SIZE, 1574 QCOW_MAX_L1_SIZE, "Active L1 table", errp); 1575 if (ret < 0) { 1576 goto fail; 1577 } 1578 s->l1_size = header.l1_size; 1579 s->l1_table_offset = header.l1_table_offset; 1580 1581 l1_vm_state_index = size_to_l1(s, header.size); 1582 if (l1_vm_state_index > INT_MAX) { 1583 error_setg(errp, "Image is too big"); 1584 ret = -EFBIG; 1585 goto fail; 1586 } 1587 s->l1_vm_state_index = l1_vm_state_index; 1588 1589 /* the L1 table must contain at least enough entries to put 1590 header.size bytes */ 1591 if (s->l1_size < s->l1_vm_state_index) { 1592 error_setg(errp, "L1 table is too small"); 1593 ret = -EINVAL; 1594 goto fail; 1595 } 1596 1597 if (s->l1_size > 0) { 1598 s->l1_table = qemu_try_blockalign(bs->file->bs, s->l1_size * L1E_SIZE); 1599 if (s->l1_table == NULL) { 1600 error_setg(errp, "Could not allocate L1 table"); 1601 ret = -ENOMEM; 1602 goto fail; 1603 } 1604 ret = bdrv_co_pread(bs->file, s->l1_table_offset, s->l1_size * L1E_SIZE, 1605 s->l1_table, 0); 1606 if (ret < 0) { 1607 error_setg_errno(errp, -ret, "Could not read L1 table"); 1608 goto fail; 1609 } 1610 for(i = 0;i < s->l1_size; i++) { 1611 s->l1_table[i] = be64_to_cpu(s->l1_table[i]); 1612 } 1613 } 1614 1615 /* Parse driver-specific options */ 1616 ret = qcow2_update_options(bs, options, flags, errp); 1617 if (ret < 0) { 1618 goto fail; 1619 } 1620 1621 s->flags = flags; 1622 1623 ret = qcow2_refcount_init(bs); 1624 if (ret != 0) { 1625 error_setg_errno(errp, -ret, "Could not initialize refcount handling"); 1626 goto fail; 1627 } 1628 1629 QLIST_INIT(&s->cluster_allocs); 1630 QTAILQ_INIT(&s->discards); 1631 1632 /* read qcow2 extensions */ 1633 if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, 1634 flags, &update_header, errp)) { 1635 ret = -EINVAL; 1636 goto fail; 1637 } 1638 1639 if (open_data_file && (flags & BDRV_O_NO_IO)) { 1640 /* 1641 * Don't open the data file for 'qemu-img info' so that it can be used 1642 * to verify that an untrusted qcow2 image doesn't refer to external 1643 * files. 1644 * 1645 * Note: This still makes has_data_file() return true. 1646 */ 1647 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { 1648 s->data_file = NULL; 1649 } else { 1650 s->data_file = bs->file; 1651 } 1652 qdict_extract_subqdict(options, NULL, "data-file."); 1653 qdict_del(options, "data-file"); 1654 } else if (open_data_file) { 1655 /* Open external data file */ 1656 bdrv_graph_co_rdunlock(); 1657 s->data_file = bdrv_co_open_child(NULL, options, "data-file", bs, 1658 &child_of_bds, BDRV_CHILD_DATA, 1659 true, errp); 1660 bdrv_graph_co_rdlock(); 1661 if (*errp) { 1662 ret = -EINVAL; 1663 goto fail; 1664 } 1665 1666 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { 1667 if (!s->data_file && s->image_data_file) { 1668 bdrv_graph_co_rdunlock(); 1669 s->data_file = bdrv_co_open_child(s->image_data_file, options, 1670 "data-file", bs, 1671 &child_of_bds, 1672 BDRV_CHILD_DATA, false, errp); 1673 bdrv_graph_co_rdlock(); 1674 if (!s->data_file) { 1675 ret = -EINVAL; 1676 goto fail; 1677 } 1678 } 1679 if (!s->data_file) { 1680 error_setg(errp, "'data-file' is required for this image"); 1681 ret = -EINVAL; 1682 goto fail; 1683 } 1684 1685 /* No data here */ 1686 bs->file->role &= ~BDRV_CHILD_DATA; 1687 1688 /* Must succeed because we have given up permissions if anything */ 1689 bdrv_child_refresh_perms(bs, bs->file, &error_abort); 1690 } else { 1691 if (s->data_file) { 1692 error_setg(errp, "'data-file' can only be set for images with " 1693 "an external data file"); 1694 ret = -EINVAL; 1695 goto fail; 1696 } 1697 1698 s->data_file = bs->file; 1699 1700 if (data_file_is_raw(bs)) { 1701 error_setg(errp, "data-file-raw requires a data file"); 1702 ret = -EINVAL; 1703 goto fail; 1704 } 1705 } 1706 } 1707 1708 /* qcow2_read_extension may have set up the crypto context 1709 * if the crypt method needs a header region, some methods 1710 * don't need header extensions, so must check here 1711 */ 1712 if (s->crypt_method_header && !s->crypto) { 1713 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1714 unsigned int cflags = 0; 1715 if (flags & BDRV_O_NO_IO) { 1716 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 1717 } 1718 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 1719 NULL, NULL, cflags, errp); 1720 if (!s->crypto) { 1721 ret = -EINVAL; 1722 goto fail; 1723 } 1724 } else if (!(flags & BDRV_O_NO_IO)) { 1725 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1726 s->crypt_method_header); 1727 ret = -EINVAL; 1728 goto fail; 1729 } 1730 } 1731 1732 /* read the backing file name */ 1733 if (header.backing_file_offset != 0) { 1734 len = header.backing_file_size; 1735 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1736 len >= sizeof(bs->backing_file)) { 1737 error_setg(errp, "Backing file name too long"); 1738 ret = -EINVAL; 1739 goto fail; 1740 } 1741 1742 s->image_backing_file = g_malloc(len + 1); 1743 ret = bdrv_co_pread(bs->file, header.backing_file_offset, len, 1744 s->image_backing_file, 0); 1745 if (ret < 0) { 1746 error_setg_errno(errp, -ret, "Could not read backing file name"); 1747 goto fail; 1748 } 1749 s->image_backing_file[len] = '\0'; 1750 1751 /* 1752 * Update only when something has changed. This function is called by 1753 * qcow2_co_invalidate_cache(), and we do not want to reset 1754 * auto_backing_file unless necessary. 1755 */ 1756 if (!g_str_equal(s->image_backing_file, bs->backing_file)) { 1757 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1758 s->image_backing_file); 1759 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 1760 s->image_backing_file); 1761 } 1762 } 1763 1764 /* 1765 * Internal snapshots; skip reading them in check mode, because 1766 * we do not need them then, and we do not want to abort because 1767 * of a broken table. 1768 */ 1769 if (!(flags & BDRV_O_CHECK)) { 1770 s->snapshots_offset = header.snapshots_offset; 1771 s->nb_snapshots = header.nb_snapshots; 1772 1773 ret = qcow2_read_snapshots(bs, errp); 1774 if (ret < 0) { 1775 goto fail; 1776 } 1777 } 1778 1779 /* Clear unknown autoclear feature bits */ 1780 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1781 update_header = update_header && bdrv_is_writable(bs); 1782 if (update_header) { 1783 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1784 } 1785 1786 /* == Handle persistent dirty bitmaps == 1787 * 1788 * We want load dirty bitmaps in three cases: 1789 * 1790 * 1. Normal open of the disk in active mode, not related to invalidation 1791 * after migration. 1792 * 1793 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1794 * bitmaps are _not_ migrating through migration channel, i.e. 1795 * 'dirty-bitmaps' capability is disabled. 1796 * 1797 * 3. Invalidation of source vm after failed or canceled migration. 1798 * This is a very interesting case. There are two possible types of 1799 * bitmaps: 1800 * 1801 * A. Stored on inactivation and removed. They should be loaded from the 1802 * image. 1803 * 1804 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1805 * the migration channel (with dirty-bitmaps capability). 1806 * 1807 * On the other hand, there are two possible sub-cases: 1808 * 1809 * 3.1 disk was changed by somebody else while were inactive. In this 1810 * case all in-RAM dirty bitmaps (both persistent and not) are 1811 * definitely invalid. And we don't have any method to determine 1812 * this. 1813 * 1814 * Simple and safe thing is to just drop all the bitmaps of type B on 1815 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1816 * 1817 * On the other hand, resuming source vm, if disk was already changed 1818 * is a bad thing anyway: not only bitmaps, the whole vm state is 1819 * out of sync with disk. 1820 * 1821 * This means, that user or management tool, who for some reason 1822 * decided to resume source vm, after disk was already changed by 1823 * target vm, should at least drop all dirty bitmaps by hand. 1824 * 1825 * So, we can ignore this case for now, but TODO: "generation" 1826 * extension for qcow2, to determine, that image was changed after 1827 * last inactivation. And if it is changed, we will drop (or at least 1828 * mark as 'invalid' all the bitmaps of type B, both persistent 1829 * and not). 1830 * 1831 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1832 * to disk ('dirty-bitmaps' capability disabled), or not saved 1833 * ('dirty-bitmaps' capability enabled), but we don't need to care 1834 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1835 * and not stored has flag IN_USE=1 in the image and will be skipped 1836 * on loading. 1837 * 1838 * One remaining possible case when we don't want load bitmaps: 1839 * 1840 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1841 * will be loaded on invalidation, no needs try loading them before) 1842 */ 1843 1844 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1845 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1846 bool header_updated; 1847 if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) { 1848 ret = -EINVAL; 1849 goto fail; 1850 } 1851 1852 update_header = update_header && !header_updated; 1853 } 1854 1855 if (update_header) { 1856 ret = qcow2_update_header(bs); 1857 if (ret < 0) { 1858 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1859 goto fail; 1860 } 1861 } 1862 1863 bs->supported_zero_flags = header.version >= 3 ? 1864 BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; 1865 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; 1866 1867 /* Repair image if dirty */ 1868 if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) && 1869 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1870 BdrvCheckResult result = {0}; 1871 1872 ret = qcow2_co_check_locked(bs, &result, 1873 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1874 if (ret < 0 || result.check_errors) { 1875 if (ret >= 0) { 1876 ret = -EIO; 1877 } 1878 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1879 goto fail; 1880 } 1881 } 1882 1883 #ifdef DEBUG_ALLOC 1884 { 1885 BdrvCheckResult result = {0}; 1886 qcow2_check_refcounts(bs, &result, 0); 1887 } 1888 #endif 1889 1890 qemu_co_queue_init(&s->thread_task_queue); 1891 1892 return ret; 1893 1894 fail: 1895 g_free(s->image_data_file); 1896 if (open_data_file && has_data_file(bs)) { 1897 bdrv_graph_co_rdunlock(); 1898 bdrv_co_unref_child(bs, s->data_file); 1899 bdrv_graph_co_rdlock(); 1900 s->data_file = NULL; 1901 } 1902 g_free(s->unknown_header_fields); 1903 cleanup_unknown_header_ext(bs); 1904 qcow2_free_snapshots(bs); 1905 qcow2_refcount_close(bs); 1906 qemu_vfree(s->l1_table); 1907 /* else pre-write overlap checks in cache_destroy may crash */ 1908 s->l1_table = NULL; 1909 cache_clean_timer_del(bs); 1910 if (s->l2_table_cache) { 1911 qcow2_cache_destroy(s->l2_table_cache); 1912 } 1913 if (s->refcount_block_cache) { 1914 qcow2_cache_destroy(s->refcount_block_cache); 1915 } 1916 qcrypto_block_free(s->crypto); 1917 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1918 return ret; 1919 } 1920 1921 typedef struct QCow2OpenCo { 1922 BlockDriverState *bs; 1923 QDict *options; 1924 int flags; 1925 Error **errp; 1926 int ret; 1927 } QCow2OpenCo; 1928 1929 static void coroutine_fn qcow2_open_entry(void *opaque) 1930 { 1931 QCow2OpenCo *qoc = opaque; 1932 BDRVQcow2State *s = qoc->bs->opaque; 1933 1934 GRAPH_RDLOCK_GUARD(); 1935 1936 qemu_co_mutex_lock(&s->lock); 1937 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true, 1938 qoc->errp); 1939 qemu_co_mutex_unlock(&s->lock); 1940 1941 aio_wait_kick(); 1942 } 1943 1944 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1945 Error **errp) 1946 { 1947 BDRVQcow2State *s = bs->opaque; 1948 QCow2OpenCo qoc = { 1949 .bs = bs, 1950 .options = options, 1951 .flags = flags, 1952 .errp = errp, 1953 .ret = -EINPROGRESS 1954 }; 1955 int ret; 1956 1957 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 1958 if (ret < 0) { 1959 return ret; 1960 } 1961 1962 /* Initialise locks */ 1963 qemu_co_mutex_init(&s->lock); 1964 1965 assert(!qemu_in_coroutine()); 1966 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1967 1968 aio_co_enter(bdrv_get_aio_context(bs), 1969 qemu_coroutine_create(qcow2_open_entry, &qoc)); 1970 AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS); 1971 1972 return qoc.ret; 1973 } 1974 1975 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1976 { 1977 BDRVQcow2State *s = bs->opaque; 1978 1979 if (bs->encrypted) { 1980 /* Encryption works on a sector granularity */ 1981 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1982 } 1983 bs->bl.pwrite_zeroes_alignment = s->subcluster_size; 1984 bs->bl.pdiscard_alignment = s->cluster_size; 1985 } 1986 1987 static int GRAPH_UNLOCKED 1988 qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue, 1989 Error **errp) 1990 { 1991 BDRVQcow2State *s = state->bs->opaque; 1992 Qcow2ReopenState *r; 1993 int ret; 1994 1995 GLOBAL_STATE_CODE(); 1996 GRAPH_RDLOCK_GUARD_MAINLOOP(); 1997 1998 r = g_new0(Qcow2ReopenState, 1); 1999 state->opaque = r; 2000 2001 ret = qcow2_update_options_prepare(state->bs, r, state->options, 2002 state->flags, errp); 2003 if (ret < 0) { 2004 goto fail; 2005 } 2006 2007 /* We need to write out any unwritten data if we reopen read-only. */ 2008 if ((state->flags & BDRV_O_RDWR) == 0) { 2009 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 2010 if (ret < 0) { 2011 goto fail; 2012 } 2013 2014 ret = bdrv_flush(state->bs); 2015 if (ret < 0) { 2016 goto fail; 2017 } 2018 2019 ret = qcow2_mark_clean(state->bs); 2020 if (ret < 0) { 2021 goto fail; 2022 } 2023 } 2024 2025 /* 2026 * Without an external data file, s->data_file points to the same BdrvChild 2027 * as bs->file. It needs to be resynced after reopen because bs->file may 2028 * be changed. We can't use it in the meantime. 2029 */ 2030 if (!has_data_file(state->bs)) { 2031 assert(s->data_file == state->bs->file); 2032 s->data_file = NULL; 2033 } 2034 2035 return 0; 2036 2037 fail: 2038 qcow2_update_options_abort(state->bs, r); 2039 g_free(r); 2040 return ret; 2041 } 2042 2043 static void qcow2_reopen_commit(BDRVReopenState *state) 2044 { 2045 BDRVQcow2State *s = state->bs->opaque; 2046 2047 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2048 2049 qcow2_update_options_commit(state->bs, state->opaque); 2050 if (!s->data_file) { 2051 /* 2052 * If we don't have an external data file, s->data_file was cleared by 2053 * qcow2_reopen_prepare() and needs to be updated. 2054 */ 2055 s->data_file = state->bs->file; 2056 } 2057 g_free(state->opaque); 2058 } 2059 2060 static void qcow2_reopen_commit_post(BDRVReopenState *state) 2061 { 2062 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2063 2064 if (state->flags & BDRV_O_RDWR) { 2065 Error *local_err = NULL; 2066 2067 if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { 2068 /* 2069 * This is not fatal, bitmaps just left read-only, so all following 2070 * writes will fail. User can remove read-only bitmaps to unblock 2071 * writes or retry reopen. 2072 */ 2073 error_reportf_err(local_err, 2074 "%s: Failed to make dirty bitmaps writable: ", 2075 bdrv_get_node_name(state->bs)); 2076 } 2077 } 2078 } 2079 2080 static void qcow2_reopen_abort(BDRVReopenState *state) 2081 { 2082 BDRVQcow2State *s = state->bs->opaque; 2083 2084 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2085 2086 if (!s->data_file) { 2087 /* 2088 * If we don't have an external data file, s->data_file was cleared by 2089 * qcow2_reopen_prepare() and needs to be restored. 2090 */ 2091 s->data_file = state->bs->file; 2092 } 2093 qcow2_update_options_abort(state->bs, state->opaque); 2094 g_free(state->opaque); 2095 } 2096 2097 static void qcow2_join_options(QDict *options, QDict *old_options) 2098 { 2099 bool has_new_overlap_template = 2100 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 2101 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 2102 bool has_new_total_cache_size = 2103 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 2104 bool has_all_cache_options; 2105 2106 /* New overlap template overrides all old overlap options */ 2107 if (has_new_overlap_template) { 2108 qdict_del(old_options, QCOW2_OPT_OVERLAP); 2109 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 2110 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 2111 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 2112 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 2113 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 2114 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 2115 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 2116 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 2117 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 2118 } 2119 2120 /* New total cache size overrides all old options */ 2121 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 2122 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 2123 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2124 } 2125 2126 qdict_join(options, old_options, false); 2127 2128 /* 2129 * If after merging all cache size options are set, an old total size is 2130 * overwritten. Do keep all options, however, if all three are new. The 2131 * resulting error message is what we want to happen. 2132 */ 2133 has_all_cache_options = 2134 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 2135 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 2136 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 2137 2138 if (has_all_cache_options && !has_new_total_cache_size) { 2139 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 2140 } 2141 } 2142 2143 static int coroutine_fn GRAPH_RDLOCK 2144 qcow2_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, 2145 int64_t count, int64_t *pnum, int64_t *map, 2146 BlockDriverState **file) 2147 { 2148 BDRVQcow2State *s = bs->opaque; 2149 uint64_t host_offset; 2150 unsigned int bytes; 2151 QCow2SubclusterType type; 2152 int ret, status = 0; 2153 2154 qemu_co_mutex_lock(&s->lock); 2155 2156 if (!s->metadata_preallocation_checked) { 2157 ret = qcow2_detect_metadata_preallocation(bs); 2158 s->metadata_preallocation = (ret == 1); 2159 s->metadata_preallocation_checked = true; 2160 } 2161 2162 bytes = MIN(INT_MAX, count); 2163 ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type); 2164 qemu_co_mutex_unlock(&s->lock); 2165 if (ret < 0) { 2166 return ret; 2167 } 2168 2169 *pnum = bytes; 2170 2171 if ((type == QCOW2_SUBCLUSTER_NORMAL || 2172 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2173 type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) { 2174 *map = host_offset; 2175 *file = s->data_file->bs; 2176 status |= BDRV_BLOCK_OFFSET_VALID; 2177 } 2178 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2179 type == QCOW2_SUBCLUSTER_ZERO_ALLOC) { 2180 status |= BDRV_BLOCK_ZERO; 2181 } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 2182 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) { 2183 status |= BDRV_BLOCK_DATA; 2184 } 2185 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && 2186 (status & BDRV_BLOCK_OFFSET_VALID)) 2187 { 2188 status |= BDRV_BLOCK_RECURSE; 2189 } 2190 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 2191 status |= BDRV_BLOCK_COMPRESSED; 2192 } 2193 return status; 2194 } 2195 2196 static int coroutine_fn GRAPH_RDLOCK 2197 qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2) 2198 { 2199 int ret = 0; 2200 QCowL2Meta *l2meta = *pl2meta; 2201 2202 while (l2meta != NULL) { 2203 QCowL2Meta *next; 2204 2205 if (link_l2) { 2206 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 2207 if (ret) { 2208 goto out; 2209 } 2210 } else { 2211 qcow2_alloc_cluster_abort(bs, l2meta); 2212 } 2213 2214 /* Take the request off the list of running requests */ 2215 QLIST_REMOVE(l2meta, next_in_flight); 2216 2217 qemu_co_queue_restart_all(&l2meta->dependent_requests); 2218 2219 next = l2meta->next; 2220 g_free(l2meta); 2221 l2meta = next; 2222 } 2223 out: 2224 *pl2meta = l2meta; 2225 return ret; 2226 } 2227 2228 static int coroutine_fn GRAPH_RDLOCK 2229 qcow2_co_preadv_encrypted(BlockDriverState *bs, 2230 uint64_t host_offset, 2231 uint64_t offset, 2232 uint64_t bytes, 2233 QEMUIOVector *qiov, 2234 uint64_t qiov_offset) 2235 { 2236 int ret; 2237 BDRVQcow2State *s = bs->opaque; 2238 uint8_t *buf; 2239 2240 assert(bs->encrypted && s->crypto); 2241 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2242 2243 /* 2244 * For encrypted images, read everything into a temporary 2245 * contiguous buffer on which the AES functions can work. 2246 * Also, decryption in a separate buffer is better as it 2247 * prevents the guest from learning information about the 2248 * encrypted nature of the virtual disk. 2249 */ 2250 2251 buf = qemu_try_blockalign(s->data_file->bs, bytes); 2252 if (buf == NULL) { 2253 return -ENOMEM; 2254 } 2255 2256 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2257 ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0); 2258 if (ret < 0) { 2259 goto fail; 2260 } 2261 2262 if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0) 2263 { 2264 ret = -EIO; 2265 goto fail; 2266 } 2267 qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); 2268 2269 fail: 2270 qemu_vfree(buf); 2271 2272 return ret; 2273 } 2274 2275 typedef struct Qcow2AioTask { 2276 AioTask task; 2277 2278 BlockDriverState *bs; 2279 QCow2SubclusterType subcluster_type; /* only for read */ 2280 uint64_t host_offset; /* or l2_entry for compressed read */ 2281 uint64_t offset; 2282 uint64_t bytes; 2283 QEMUIOVector *qiov; 2284 uint64_t qiov_offset; 2285 QCowL2Meta *l2meta; /* only for write */ 2286 } Qcow2AioTask; 2287 2288 static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); 2289 static coroutine_fn int qcow2_add_task(BlockDriverState *bs, 2290 AioTaskPool *pool, 2291 AioTaskFunc func, 2292 QCow2SubclusterType subcluster_type, 2293 uint64_t host_offset, 2294 uint64_t offset, 2295 uint64_t bytes, 2296 QEMUIOVector *qiov, 2297 size_t qiov_offset, 2298 QCowL2Meta *l2meta) 2299 { 2300 Qcow2AioTask local_task; 2301 Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; 2302 2303 *task = (Qcow2AioTask) { 2304 .task.func = func, 2305 .bs = bs, 2306 .subcluster_type = subcluster_type, 2307 .qiov = qiov, 2308 .host_offset = host_offset, 2309 .offset = offset, 2310 .bytes = bytes, 2311 .qiov_offset = qiov_offset, 2312 .l2meta = l2meta, 2313 }; 2314 2315 trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, 2316 func == qcow2_co_preadv_task_entry ? "read" : "write", 2317 subcluster_type, host_offset, offset, bytes, 2318 qiov, qiov_offset); 2319 2320 if (!pool) { 2321 return func(&task->task); 2322 } 2323 2324 aio_task_pool_start_task(pool, &task->task); 2325 2326 return 0; 2327 } 2328 2329 static int coroutine_fn GRAPH_RDLOCK 2330 qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type, 2331 uint64_t host_offset, uint64_t offset, uint64_t bytes, 2332 QEMUIOVector *qiov, size_t qiov_offset) 2333 { 2334 BDRVQcow2State *s = bs->opaque; 2335 2336 switch (subc_type) { 2337 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 2338 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 2339 /* Both zero types are handled in qcow2_co_preadv_part */ 2340 g_assert_not_reached(); 2341 2342 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 2343 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 2344 assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ 2345 2346 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2347 return bdrv_co_preadv_part(bs->backing, offset, bytes, 2348 qiov, qiov_offset, 0); 2349 2350 case QCOW2_SUBCLUSTER_COMPRESSED: 2351 return qcow2_co_preadv_compressed(bs, host_offset, 2352 offset, bytes, qiov, qiov_offset); 2353 2354 case QCOW2_SUBCLUSTER_NORMAL: 2355 if (bs->encrypted) { 2356 return qcow2_co_preadv_encrypted(bs, host_offset, 2357 offset, bytes, qiov, qiov_offset); 2358 } 2359 2360 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 2361 return bdrv_co_preadv_part(s->data_file, host_offset, 2362 bytes, qiov, qiov_offset, 0); 2363 2364 default: 2365 g_assert_not_reached(); 2366 } 2367 2368 g_assert_not_reached(); 2369 } 2370 2371 /* 2372 * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds 2373 * the graph lock and keeps it until this coroutine has terminated. 2374 */ 2375 static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task) 2376 { 2377 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2378 2379 assert(!t->l2meta); 2380 2381 return qcow2_co_preadv_task(t->bs, t->subcluster_type, 2382 t->host_offset, t->offset, t->bytes, 2383 t->qiov, t->qiov_offset); 2384 } 2385 2386 static int coroutine_fn GRAPH_RDLOCK 2387 qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2388 QEMUIOVector *qiov, size_t qiov_offset, 2389 BdrvRequestFlags flags) 2390 { 2391 BDRVQcow2State *s = bs->opaque; 2392 int ret = 0; 2393 unsigned int cur_bytes; /* number of bytes in current iteration */ 2394 uint64_t host_offset = 0; 2395 QCow2SubclusterType type; 2396 AioTaskPool *aio = NULL; 2397 2398 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2399 /* prepare next request */ 2400 cur_bytes = MIN(bytes, INT_MAX); 2401 if (s->crypto) { 2402 cur_bytes = MIN(cur_bytes, 2403 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2404 } 2405 2406 qemu_co_mutex_lock(&s->lock); 2407 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, 2408 &host_offset, &type); 2409 qemu_co_mutex_unlock(&s->lock); 2410 if (ret < 0) { 2411 goto out; 2412 } 2413 2414 if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || 2415 type == QCOW2_SUBCLUSTER_ZERO_ALLOC || 2416 (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) || 2417 (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing)) 2418 { 2419 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2420 } else { 2421 if (!aio && cur_bytes != bytes) { 2422 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2423 } 2424 ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type, 2425 host_offset, offset, cur_bytes, 2426 qiov, qiov_offset, NULL); 2427 if (ret < 0) { 2428 goto out; 2429 } 2430 } 2431 2432 bytes -= cur_bytes; 2433 offset += cur_bytes; 2434 qiov_offset += cur_bytes; 2435 } 2436 2437 out: 2438 if (aio) { 2439 aio_task_pool_wait_all(aio); 2440 if (ret == 0) { 2441 ret = aio_task_pool_status(aio); 2442 } 2443 g_free(aio); 2444 } 2445 2446 return ret; 2447 } 2448 2449 /* Check if it's possible to merge a write request with the writing of 2450 * the data from the COW regions */ 2451 static bool merge_cow(uint64_t offset, unsigned bytes, 2452 QEMUIOVector *qiov, size_t qiov_offset, 2453 QCowL2Meta *l2meta) 2454 { 2455 QCowL2Meta *m; 2456 2457 for (m = l2meta; m != NULL; m = m->next) { 2458 /* If both COW regions are empty then there's nothing to merge */ 2459 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2460 continue; 2461 } 2462 2463 /* If COW regions are handled already, skip this too */ 2464 if (m->skip_cow) { 2465 continue; 2466 } 2467 2468 /* 2469 * The write request should start immediately after the first 2470 * COW region. This does not always happen because the area 2471 * touched by the request can be larger than the one defined 2472 * by @m (a single request can span an area consisting of a 2473 * mix of previously unallocated and allocated clusters, that 2474 * is why @l2meta is a list). 2475 */ 2476 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2477 /* In this case the request starts before this region */ 2478 assert(offset < l2meta_cow_start(m)); 2479 assert(m->cow_start.nb_bytes == 0); 2480 continue; 2481 } 2482 2483 /* The write request should end immediately before the second 2484 * COW region (see above for why it does not always happen) */ 2485 if (m->offset + m->cow_end.offset != offset + bytes) { 2486 assert(offset + bytes > m->offset + m->cow_end.offset); 2487 assert(m->cow_end.nb_bytes == 0); 2488 continue; 2489 } 2490 2491 /* Make sure that adding both COW regions to the QEMUIOVector 2492 * does not exceed IOV_MAX */ 2493 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { 2494 continue; 2495 } 2496 2497 m->data_qiov = qiov; 2498 m->data_qiov_offset = qiov_offset; 2499 return true; 2500 } 2501 2502 return false; 2503 } 2504 2505 /* 2506 * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error. 2507 * Note that returning 0 does not guarantee non-zero data. 2508 */ 2509 static int coroutine_fn GRAPH_RDLOCK 2510 is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) 2511 { 2512 /* 2513 * This check is designed for optimization shortcut so it must be 2514 * efficient. 2515 * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is 2516 * faster (but not as accurate and can result in false negatives). 2517 */ 2518 int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset, 2519 m->cow_start.nb_bytes); 2520 if (ret <= 0) { 2521 return ret; 2522 } 2523 2524 return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset, 2525 m->cow_end.nb_bytes); 2526 } 2527 2528 static int coroutine_fn GRAPH_RDLOCK 2529 handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) 2530 { 2531 BDRVQcow2State *s = bs->opaque; 2532 QCowL2Meta *m; 2533 2534 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { 2535 return 0; 2536 } 2537 2538 if (bs->encrypted) { 2539 return 0; 2540 } 2541 2542 for (m = l2meta; m != NULL; m = m->next) { 2543 int ret; 2544 uint64_t start_offset = m->alloc_offset + m->cow_start.offset; 2545 unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes - 2546 m->cow_start.offset; 2547 2548 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { 2549 continue; 2550 } 2551 2552 ret = is_zero_cow(bs, m); 2553 if (ret < 0) { 2554 return ret; 2555 } else if (ret == 0) { 2556 continue; 2557 } 2558 2559 /* 2560 * instead of writing zero COW buffers, 2561 * efficiently zero out the whole clusters 2562 */ 2563 2564 ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes, 2565 true); 2566 if (ret < 0) { 2567 return ret; 2568 } 2569 2570 BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); 2571 ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes, 2572 BDRV_REQ_NO_FALLBACK); 2573 if (ret < 0) { 2574 if (ret != -ENOTSUP && ret != -EAGAIN) { 2575 return ret; 2576 } 2577 continue; 2578 } 2579 2580 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); 2581 m->skip_cow = true; 2582 } 2583 return 0; 2584 } 2585 2586 /* 2587 * qcow2_co_pwritev_task 2588 * Called with s->lock unlocked 2589 * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must 2590 * not use it somehow after qcow2_co_pwritev_task() call 2591 */ 2592 static coroutine_fn GRAPH_RDLOCK 2593 int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset, 2594 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, 2595 uint64_t qiov_offset, QCowL2Meta *l2meta) 2596 { 2597 int ret; 2598 BDRVQcow2State *s = bs->opaque; 2599 void *crypt_buf = NULL; 2600 QEMUIOVector encrypted_qiov; 2601 2602 if (bs->encrypted) { 2603 assert(s->crypto); 2604 assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2605 crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); 2606 if (crypt_buf == NULL) { 2607 ret = -ENOMEM; 2608 goto out_unlocked; 2609 } 2610 qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); 2611 2612 if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) { 2613 ret = -EIO; 2614 goto out_unlocked; 2615 } 2616 2617 qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); 2618 qiov = &encrypted_qiov; 2619 qiov_offset = 0; 2620 } 2621 2622 /* Try to efficiently initialize the physical space with zeroes */ 2623 ret = handle_alloc_space(bs, l2meta); 2624 if (ret < 0) { 2625 goto out_unlocked; 2626 } 2627 2628 /* 2629 * If we need to do COW, check if it's possible to merge the 2630 * writing of the guest data together with that of the COW regions. 2631 * If it's not possible (or not necessary) then write the 2632 * guest data now. 2633 */ 2634 if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { 2635 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 2636 trace_qcow2_writev_data(qemu_coroutine_self(), host_offset); 2637 ret = bdrv_co_pwritev_part(s->data_file, host_offset, 2638 bytes, qiov, qiov_offset, 0); 2639 if (ret < 0) { 2640 goto out_unlocked; 2641 } 2642 } 2643 2644 qemu_co_mutex_lock(&s->lock); 2645 2646 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2647 goto out_locked; 2648 2649 out_unlocked: 2650 qemu_co_mutex_lock(&s->lock); 2651 2652 out_locked: 2653 qcow2_handle_l2meta(bs, &l2meta, false); 2654 qemu_co_mutex_unlock(&s->lock); 2655 2656 qemu_vfree(crypt_buf); 2657 2658 return ret; 2659 } 2660 2661 /* 2662 * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds 2663 * the graph lock and keeps it until this coroutine has terminated. 2664 */ 2665 static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task) 2666 { 2667 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 2668 2669 assert(!t->subcluster_type); 2670 2671 return qcow2_co_pwritev_task(t->bs, t->host_offset, 2672 t->offset, t->bytes, t->qiov, t->qiov_offset, 2673 t->l2meta); 2674 } 2675 2676 static int coroutine_fn GRAPH_RDLOCK 2677 qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes, 2678 QEMUIOVector *qiov, size_t qiov_offset, 2679 BdrvRequestFlags flags) 2680 { 2681 BDRVQcow2State *s = bs->opaque; 2682 int offset_in_cluster; 2683 int ret; 2684 unsigned int cur_bytes; /* number of sectors in current iteration */ 2685 uint64_t host_offset; 2686 QCowL2Meta *l2meta = NULL; 2687 AioTaskPool *aio = NULL; 2688 2689 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2690 2691 while (bytes != 0 && aio_task_pool_status(aio) == 0) { 2692 2693 l2meta = NULL; 2694 2695 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2696 offset_in_cluster = offset_into_cluster(s, offset); 2697 cur_bytes = MIN(bytes, INT_MAX); 2698 if (bs->encrypted) { 2699 cur_bytes = MIN(cur_bytes, 2700 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2701 - offset_in_cluster); 2702 } 2703 2704 qemu_co_mutex_lock(&s->lock); 2705 2706 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 2707 &host_offset, &l2meta); 2708 if (ret < 0) { 2709 goto out_locked; 2710 } 2711 2712 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, 2713 cur_bytes, true); 2714 if (ret < 0) { 2715 goto out_locked; 2716 } 2717 2718 qemu_co_mutex_unlock(&s->lock); 2719 2720 if (!aio && cur_bytes != bytes) { 2721 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 2722 } 2723 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, 2724 host_offset, offset, 2725 cur_bytes, qiov, qiov_offset, l2meta); 2726 l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ 2727 if (ret < 0) { 2728 goto fail_nometa; 2729 } 2730 2731 bytes -= cur_bytes; 2732 offset += cur_bytes; 2733 qiov_offset += cur_bytes; 2734 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2735 } 2736 ret = 0; 2737 2738 qemu_co_mutex_lock(&s->lock); 2739 2740 out_locked: 2741 qcow2_handle_l2meta(bs, &l2meta, false); 2742 2743 qemu_co_mutex_unlock(&s->lock); 2744 2745 fail_nometa: 2746 if (aio) { 2747 aio_task_pool_wait_all(aio); 2748 if (ret == 0) { 2749 ret = aio_task_pool_status(aio); 2750 } 2751 g_free(aio); 2752 } 2753 2754 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2755 2756 return ret; 2757 } 2758 2759 static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs) 2760 { 2761 BDRVQcow2State *s = bs->opaque; 2762 int ret, result = 0; 2763 Error *local_err = NULL; 2764 2765 qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); 2766 if (local_err != NULL) { 2767 result = -EINVAL; 2768 error_reportf_err(local_err, "Lost persistent bitmaps during " 2769 "inactivation of node '%s': ", 2770 bdrv_get_device_or_node_name(bs)); 2771 } 2772 2773 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2774 if (ret) { 2775 result = ret; 2776 error_report("Failed to flush the L2 table cache: %s", 2777 strerror(-ret)); 2778 } 2779 2780 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2781 if (ret) { 2782 result = ret; 2783 error_report("Failed to flush the refcount block cache: %s", 2784 strerror(-ret)); 2785 } 2786 2787 if (result == 0) { 2788 qcow2_mark_clean(bs); 2789 } 2790 2791 return result; 2792 } 2793 2794 static void coroutine_mixed_fn GRAPH_RDLOCK 2795 qcow2_do_close(BlockDriverState *bs, bool close_data_file) 2796 { 2797 BDRVQcow2State *s = bs->opaque; 2798 qemu_vfree(s->l1_table); 2799 /* else pre-write overlap checks in cache_destroy may crash */ 2800 s->l1_table = NULL; 2801 2802 if (!(s->flags & BDRV_O_INACTIVE)) { 2803 qcow2_inactivate(bs); 2804 } 2805 2806 cache_clean_timer_del(bs); 2807 qcow2_cache_destroy(s->l2_table_cache); 2808 qcow2_cache_destroy(s->refcount_block_cache); 2809 2810 qcrypto_block_free(s->crypto); 2811 s->crypto = NULL; 2812 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 2813 2814 g_free(s->unknown_header_fields); 2815 cleanup_unknown_header_ext(bs); 2816 2817 g_free(s->image_data_file); 2818 g_free(s->image_backing_file); 2819 g_free(s->image_backing_format); 2820 2821 if (close_data_file && has_data_file(bs)) { 2822 GLOBAL_STATE_CODE(); 2823 bdrv_graph_rdunlock_main_loop(); 2824 bdrv_graph_wrlock(); 2825 bdrv_unref_child(bs, s->data_file); 2826 bdrv_graph_wrunlock(); 2827 s->data_file = NULL; 2828 bdrv_graph_rdlock_main_loop(); 2829 } 2830 2831 qcow2_refcount_close(bs); 2832 qcow2_free_snapshots(bs); 2833 } 2834 2835 static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs) 2836 { 2837 GLOBAL_STATE_CODE(); 2838 GRAPH_RDLOCK_GUARD_MAINLOOP(); 2839 2840 qcow2_do_close(bs, true); 2841 } 2842 2843 static void coroutine_fn GRAPH_RDLOCK 2844 qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp) 2845 { 2846 ERRP_GUARD(); 2847 BDRVQcow2State *s = bs->opaque; 2848 BdrvChild *data_file; 2849 int flags = s->flags; 2850 QCryptoBlock *crypto = NULL; 2851 QDict *options; 2852 int ret; 2853 2854 /* 2855 * Backing files are read-only which makes all of their metadata immutable, 2856 * that means we don't have to worry about reopening them here. 2857 */ 2858 2859 crypto = s->crypto; 2860 s->crypto = NULL; 2861 2862 /* 2863 * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it, 2864 * and then prevent qcow2_do_open() from opening it), because this function 2865 * runs in the I/O path and as such we must not invoke global-state 2866 * functions like bdrv_unref_child() and bdrv_open_child(). 2867 */ 2868 2869 qcow2_do_close(bs, false); 2870 2871 data_file = s->data_file; 2872 memset(s, 0, sizeof(BDRVQcow2State)); 2873 s->data_file = data_file; 2874 2875 options = qdict_clone_shallow(bs->options); 2876 2877 flags &= ~BDRV_O_INACTIVE; 2878 qemu_co_mutex_lock(&s->lock); 2879 ret = qcow2_do_open(bs, options, flags, false, errp); 2880 qemu_co_mutex_unlock(&s->lock); 2881 qobject_unref(options); 2882 if (ret < 0) { 2883 error_prepend(errp, "Could not reopen qcow2 layer: "); 2884 bs->drv = NULL; 2885 return; 2886 } 2887 2888 s->crypto = crypto; 2889 } 2890 2891 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2892 size_t len, size_t buflen) 2893 { 2894 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2895 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2896 2897 if (buflen < ext_len) { 2898 return -ENOSPC; 2899 } 2900 2901 *ext_backing_fmt = (QCowExtension) { 2902 .magic = cpu_to_be32(magic), 2903 .len = cpu_to_be32(len), 2904 }; 2905 2906 if (len) { 2907 memcpy(buf + sizeof(QCowExtension), s, len); 2908 } 2909 2910 return ext_len; 2911 } 2912 2913 /* 2914 * Updates the qcow2 header, including the variable length parts of it, i.e. 2915 * the backing file name and all extensions. qcow2 was not designed to allow 2916 * such changes, so if we run out of space (we can only use the first cluster) 2917 * this function may fail. 2918 * 2919 * Returns 0 on success, -errno in error cases. 2920 */ 2921 int qcow2_update_header(BlockDriverState *bs) 2922 { 2923 BDRVQcow2State *s = bs->opaque; 2924 QCowHeader *header; 2925 char *buf; 2926 size_t buflen = s->cluster_size; 2927 int ret; 2928 uint64_t total_size; 2929 uint32_t refcount_table_clusters; 2930 size_t header_length; 2931 Qcow2UnknownHeaderExtension *uext; 2932 2933 buf = qemu_blockalign(bs, buflen); 2934 2935 /* Header structure */ 2936 header = (QCowHeader*) buf; 2937 2938 if (buflen < sizeof(*header)) { 2939 ret = -ENOSPC; 2940 goto fail; 2941 } 2942 2943 header_length = sizeof(*header) + s->unknown_header_fields_size; 2944 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2945 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2946 2947 ret = validate_compression_type(s, NULL); 2948 if (ret) { 2949 goto fail; 2950 } 2951 2952 *header = (QCowHeader) { 2953 /* Version 2 fields */ 2954 .magic = cpu_to_be32(QCOW_MAGIC), 2955 .version = cpu_to_be32(s->qcow_version), 2956 .backing_file_offset = 0, 2957 .backing_file_size = 0, 2958 .cluster_bits = cpu_to_be32(s->cluster_bits), 2959 .size = cpu_to_be64(total_size), 2960 .crypt_method = cpu_to_be32(s->crypt_method_header), 2961 .l1_size = cpu_to_be32(s->l1_size), 2962 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2963 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2964 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2965 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2966 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2967 2968 /* Version 3 fields */ 2969 .incompatible_features = cpu_to_be64(s->incompatible_features), 2970 .compatible_features = cpu_to_be64(s->compatible_features), 2971 .autoclear_features = cpu_to_be64(s->autoclear_features), 2972 .refcount_order = cpu_to_be32(s->refcount_order), 2973 .header_length = cpu_to_be32(header_length), 2974 .compression_type = s->compression_type, 2975 }; 2976 2977 /* For older versions, write a shorter header */ 2978 switch (s->qcow_version) { 2979 case 2: 2980 ret = offsetof(QCowHeader, incompatible_features); 2981 break; 2982 case 3: 2983 ret = sizeof(*header); 2984 break; 2985 default: 2986 ret = -EINVAL; 2987 goto fail; 2988 } 2989 2990 buf += ret; 2991 buflen -= ret; 2992 memset(buf, 0, buflen); 2993 2994 /* Preserve any unknown field in the header */ 2995 if (s->unknown_header_fields_size) { 2996 if (buflen < s->unknown_header_fields_size) { 2997 ret = -ENOSPC; 2998 goto fail; 2999 } 3000 3001 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 3002 buf += s->unknown_header_fields_size; 3003 buflen -= s->unknown_header_fields_size; 3004 } 3005 3006 /* Backing file format header extension */ 3007 if (s->image_backing_format) { 3008 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 3009 s->image_backing_format, 3010 strlen(s->image_backing_format), 3011 buflen); 3012 if (ret < 0) { 3013 goto fail; 3014 } 3015 3016 buf += ret; 3017 buflen -= ret; 3018 } 3019 3020 /* External data file header extension */ 3021 if (has_data_file(bs) && s->image_data_file) { 3022 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 3023 s->image_data_file, strlen(s->image_data_file), 3024 buflen); 3025 if (ret < 0) { 3026 goto fail; 3027 } 3028 3029 buf += ret; 3030 buflen -= ret; 3031 } 3032 3033 /* Full disk encryption header pointer extension */ 3034 if (s->crypto_header.offset != 0) { 3035 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 3036 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 3037 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 3038 &s->crypto_header, sizeof(s->crypto_header), 3039 buflen); 3040 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 3041 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 3042 if (ret < 0) { 3043 goto fail; 3044 } 3045 buf += ret; 3046 buflen -= ret; 3047 } 3048 3049 /* 3050 * Feature table. A mere 8 feature names occupies 392 bytes, and 3051 * when coupled with the v3 minimum header of 104 bytes plus the 3052 * 8-byte end-of-extension marker, that would leave only 8 bytes 3053 * for a backing file name in an image with 512-byte clusters. 3054 * Thus, we choose to omit this header for cluster sizes 4k and 3055 * smaller. 3056 */ 3057 if (s->qcow_version >= 3 && s->cluster_size > 4096) { 3058 static const Qcow2Feature features[] = { 3059 { 3060 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3061 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 3062 .name = "dirty bit", 3063 }, 3064 { 3065 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3066 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 3067 .name = "corrupt bit", 3068 }, 3069 { 3070 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3071 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 3072 .name = "external data file", 3073 }, 3074 { 3075 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3076 .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, 3077 .name = "compression type", 3078 }, 3079 { 3080 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 3081 .bit = QCOW2_INCOMPAT_EXTL2_BITNR, 3082 .name = "extended L2 entries", 3083 }, 3084 { 3085 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 3086 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 3087 .name = "lazy refcounts", 3088 }, 3089 { 3090 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3091 .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, 3092 .name = "bitmaps", 3093 }, 3094 { 3095 .type = QCOW2_FEAT_TYPE_AUTOCLEAR, 3096 .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 3097 .name = "raw external data", 3098 }, 3099 }; 3100 3101 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 3102 features, sizeof(features), buflen); 3103 if (ret < 0) { 3104 goto fail; 3105 } 3106 buf += ret; 3107 buflen -= ret; 3108 } 3109 3110 /* Bitmap extension */ 3111 if (s->nb_bitmaps > 0) { 3112 Qcow2BitmapHeaderExt bitmaps_header = { 3113 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 3114 .bitmap_directory_size = 3115 cpu_to_be64(s->bitmap_directory_size), 3116 .bitmap_directory_offset = 3117 cpu_to_be64(s->bitmap_directory_offset) 3118 }; 3119 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 3120 &bitmaps_header, sizeof(bitmaps_header), 3121 buflen); 3122 if (ret < 0) { 3123 goto fail; 3124 } 3125 buf += ret; 3126 buflen -= ret; 3127 } 3128 3129 /* Keep unknown header extensions */ 3130 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 3131 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 3132 if (ret < 0) { 3133 goto fail; 3134 } 3135 3136 buf += ret; 3137 buflen -= ret; 3138 } 3139 3140 /* End of header extensions */ 3141 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 3142 if (ret < 0) { 3143 goto fail; 3144 } 3145 3146 buf += ret; 3147 buflen -= ret; 3148 3149 /* Backing file name */ 3150 if (s->image_backing_file) { 3151 size_t backing_file_len = strlen(s->image_backing_file); 3152 3153 if (buflen < backing_file_len) { 3154 ret = -ENOSPC; 3155 goto fail; 3156 } 3157 3158 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 3159 strncpy(buf, s->image_backing_file, buflen); 3160 3161 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 3162 header->backing_file_size = cpu_to_be32(backing_file_len); 3163 } 3164 3165 /* Write the new header */ 3166 ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0); 3167 if (ret < 0) { 3168 goto fail; 3169 } 3170 3171 ret = 0; 3172 fail: 3173 qemu_vfree(header); 3174 return ret; 3175 } 3176 3177 static int coroutine_fn GRAPH_RDLOCK 3178 qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file, 3179 const char *backing_fmt) 3180 { 3181 BDRVQcow2State *s = bs->opaque; 3182 3183 /* Adding a backing file means that the external data file alone won't be 3184 * enough to make sense of the content */ 3185 if (backing_file && data_file_is_raw(bs)) { 3186 return -EINVAL; 3187 } 3188 3189 if (backing_file && strlen(backing_file) > 1023) { 3190 return -EINVAL; 3191 } 3192 3193 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 3194 backing_file ?: ""); 3195 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 3196 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 3197 3198 g_free(s->image_backing_file); 3199 g_free(s->image_backing_format); 3200 3201 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 3202 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 3203 3204 return qcow2_update_header(bs); 3205 } 3206 3207 static int coroutine_fn GRAPH_RDLOCK 3208 qcow2_set_up_encryption(BlockDriverState *bs, 3209 QCryptoBlockCreateOptions *cryptoopts, 3210 Error **errp) 3211 { 3212 BDRVQcow2State *s = bs->opaque; 3213 QCryptoBlock *crypto = NULL; 3214 int fmt, ret; 3215 3216 switch (cryptoopts->format) { 3217 case QCRYPTO_BLOCK_FORMAT_LUKS: 3218 fmt = QCOW_CRYPT_LUKS; 3219 break; 3220 case QCRYPTO_BLOCK_FORMAT_QCOW: 3221 fmt = QCOW_CRYPT_AES; 3222 break; 3223 default: 3224 error_setg(errp, "Crypto format not supported in qcow2"); 3225 return -EINVAL; 3226 } 3227 3228 s->crypt_method_header = fmt; 3229 3230 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 3231 qcow2_crypto_hdr_init_func, 3232 qcow2_crypto_hdr_write_func, 3233 bs, 0, errp); 3234 if (!crypto) { 3235 return -EINVAL; 3236 } 3237 3238 ret = qcow2_update_header(bs); 3239 if (ret < 0) { 3240 error_setg_errno(errp, -ret, "Could not write encryption header"); 3241 goto out; 3242 } 3243 3244 ret = 0; 3245 out: 3246 qcrypto_block_free(crypto); 3247 return ret; 3248 } 3249 3250 /** 3251 * Preallocates metadata structures for data clusters between @offset (in the 3252 * guest disk) and @new_length (which is thus generally the new guest disk 3253 * size). 3254 * 3255 * Returns: 0 on success, -errno on failure. 3256 */ 3257 static int coroutine_fn GRAPH_RDLOCK 3258 preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length, 3259 PreallocMode mode, Error **errp) 3260 { 3261 BDRVQcow2State *s = bs->opaque; 3262 uint64_t bytes; 3263 uint64_t host_offset = 0; 3264 int64_t file_length; 3265 unsigned int cur_bytes; 3266 int ret; 3267 QCowL2Meta *meta = NULL, *m; 3268 3269 assert(offset <= new_length); 3270 bytes = new_length - offset; 3271 3272 while (bytes) { 3273 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); 3274 ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, 3275 &host_offset, &meta); 3276 if (ret < 0) { 3277 error_setg_errno(errp, -ret, "Allocating clusters failed"); 3278 goto out; 3279 } 3280 3281 for (m = meta; m != NULL; m = m->next) { 3282 m->prealloc = true; 3283 } 3284 3285 ret = qcow2_handle_l2meta(bs, &meta, true); 3286 if (ret < 0) { 3287 error_setg_errno(errp, -ret, "Mapping clusters failed"); 3288 goto out; 3289 } 3290 3291 /* TODO Preallocate data if requested */ 3292 3293 bytes -= cur_bytes; 3294 offset += cur_bytes; 3295 } 3296 3297 /* 3298 * It is expected that the image file is large enough to actually contain 3299 * all of the allocated clusters (otherwise we get failing reads after 3300 * EOF). Extend the image to the last allocated sector. 3301 */ 3302 file_length = bdrv_co_getlength(s->data_file->bs); 3303 if (file_length < 0) { 3304 error_setg_errno(errp, -file_length, "Could not get file size"); 3305 ret = file_length; 3306 goto out; 3307 } 3308 3309 if (host_offset + cur_bytes > file_length) { 3310 if (mode == PREALLOC_MODE_METADATA) { 3311 mode = PREALLOC_MODE_OFF; 3312 } 3313 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false, 3314 mode, 0, errp); 3315 if (ret < 0) { 3316 goto out; 3317 } 3318 } 3319 3320 ret = 0; 3321 3322 out: 3323 qcow2_handle_l2meta(bs, &meta, false); 3324 return ret; 3325 } 3326 3327 /* qcow2_refcount_metadata_size: 3328 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 3329 * @cluster_size: size of a cluster, in bytes 3330 * @refcount_order: refcount bits power-of-2 exponent 3331 * @generous_increase: allow for the refcount table to be 1.5x as large as it 3332 * needs to be 3333 * 3334 * Returns: Number of bytes required for refcount blocks and table metadata. 3335 */ 3336 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 3337 int refcount_order, bool generous_increase, 3338 uint64_t *refblock_count) 3339 { 3340 /* 3341 * Every host cluster is reference-counted, including metadata (even 3342 * refcount metadata is recursively included). 3343 * 3344 * An accurate formula for the size of refcount metadata size is difficult 3345 * to derive. An easier method of calculation is finding the fixed point 3346 * where no further refcount blocks or table clusters are required to 3347 * reference count every cluster. 3348 */ 3349 int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE; 3350 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 3351 int64_t table = 0; /* number of refcount table clusters */ 3352 int64_t blocks = 0; /* number of refcount block clusters */ 3353 int64_t last; 3354 int64_t n = 0; 3355 3356 do { 3357 last = n; 3358 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 3359 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 3360 n = clusters + blocks + table; 3361 3362 if (n == last && generous_increase) { 3363 clusters += DIV_ROUND_UP(table, 2); 3364 n = 0; /* force another loop */ 3365 generous_increase = false; 3366 } 3367 } while (n != last); 3368 3369 if (refblock_count) { 3370 *refblock_count = blocks; 3371 } 3372 3373 return (blocks + table) * cluster_size; 3374 } 3375 3376 /** 3377 * qcow2_calc_prealloc_size: 3378 * @total_size: virtual disk size in bytes 3379 * @cluster_size: cluster size in bytes 3380 * @refcount_order: refcount bits power-of-2 exponent 3381 * @extended_l2: true if the image has extended L2 entries 3382 * 3383 * Returns: Total number of bytes required for the fully allocated image 3384 * (including metadata). 3385 */ 3386 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 3387 size_t cluster_size, 3388 int refcount_order, 3389 bool extended_l2) 3390 { 3391 int64_t meta_size = 0; 3392 uint64_t nl1e, nl2e; 3393 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 3394 size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 3395 3396 /* header: 1 cluster */ 3397 meta_size += cluster_size; 3398 3399 /* total size of L2 tables */ 3400 nl2e = aligned_total_size / cluster_size; 3401 nl2e = ROUND_UP(nl2e, cluster_size / l2e_size); 3402 meta_size += nl2e * l2e_size; 3403 3404 /* total size of L1 tables */ 3405 nl1e = nl2e * l2e_size / cluster_size; 3406 nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE); 3407 meta_size += nl1e * L1E_SIZE; 3408 3409 /* total size of refcount table and blocks */ 3410 meta_size += qcow2_refcount_metadata_size( 3411 (meta_size + aligned_total_size) / cluster_size, 3412 cluster_size, refcount_order, false, NULL); 3413 3414 return meta_size + aligned_total_size; 3415 } 3416 3417 static bool validate_cluster_size(size_t cluster_size, bool extended_l2, 3418 Error **errp) 3419 { 3420 int cluster_bits = ctz32(cluster_size); 3421 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 3422 (1 << cluster_bits) != cluster_size) 3423 { 3424 error_setg(errp, "Cluster size must be a power of two between %d and " 3425 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 3426 return false; 3427 } 3428 3429 if (extended_l2) { 3430 unsigned min_cluster_size = 3431 (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER; 3432 if (cluster_size < min_cluster_size) { 3433 error_setg(errp, "Extended L2 entries are only supported with " 3434 "cluster sizes of at least %u bytes", min_cluster_size); 3435 return false; 3436 } 3437 } 3438 3439 return true; 3440 } 3441 3442 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2, 3443 Error **errp) 3444 { 3445 size_t cluster_size; 3446 3447 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 3448 DEFAULT_CLUSTER_SIZE); 3449 if (!validate_cluster_size(cluster_size, extended_l2, errp)) { 3450 return 0; 3451 } 3452 return cluster_size; 3453 } 3454 3455 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 3456 { 3457 char *buf; 3458 int ret; 3459 3460 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 3461 if (!buf) { 3462 ret = 3; /* default */ 3463 } else if (!strcmp(buf, "0.10")) { 3464 ret = 2; 3465 } else if (!strcmp(buf, "1.1")) { 3466 ret = 3; 3467 } else { 3468 error_setg(errp, "Invalid compatibility level: '%s'", buf); 3469 ret = -EINVAL; 3470 } 3471 g_free(buf); 3472 return ret; 3473 } 3474 3475 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 3476 Error **errp) 3477 { 3478 uint64_t refcount_bits; 3479 3480 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 3481 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 3482 error_setg(errp, "Refcount width must be a power of two and may not " 3483 "exceed 64 bits"); 3484 return 0; 3485 } 3486 3487 if (version < 3 && refcount_bits != 16) { 3488 error_setg(errp, "Different refcount widths than 16 bits require " 3489 "compatibility level 1.1 or above (use compat=1.1 or " 3490 "greater)"); 3491 return 0; 3492 } 3493 3494 return refcount_bits; 3495 } 3496 3497 static int coroutine_fn GRAPH_UNLOCKED 3498 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 3499 { 3500 ERRP_GUARD(); 3501 BlockdevCreateOptionsQcow2 *qcow2_opts; 3502 QDict *options; 3503 3504 /* 3505 * Open the image file and write a minimal qcow2 header. 3506 * 3507 * We keep things simple and start with a zero-sized image. We also 3508 * do without refcount blocks or a L1 table for now. We'll fix the 3509 * inconsistency later. 3510 * 3511 * We do need a refcount table because growing the refcount table means 3512 * allocating two new refcount blocks - the second of which would be at 3513 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 3514 * size for any qcow2 image. 3515 */ 3516 BlockBackend *blk = NULL; 3517 BlockDriverState *bs = NULL; 3518 BlockDriverState *data_bs = NULL; 3519 QCowHeader *header; 3520 size_t cluster_size; 3521 int version; 3522 int refcount_order; 3523 uint64_t *refcount_table; 3524 int ret; 3525 uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 3526 3527 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 3528 qcow2_opts = &create_options->u.qcow2; 3529 3530 bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp); 3531 if (bs == NULL) { 3532 return -EIO; 3533 } 3534 3535 /* Validate options and set default values */ 3536 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 3537 error_setg(errp, "Image size must be a multiple of %u bytes", 3538 (unsigned) BDRV_SECTOR_SIZE); 3539 ret = -EINVAL; 3540 goto out; 3541 } 3542 3543 if (qcow2_opts->has_version) { 3544 switch (qcow2_opts->version) { 3545 case BLOCKDEV_QCOW2_VERSION_V2: 3546 version = 2; 3547 break; 3548 case BLOCKDEV_QCOW2_VERSION_V3: 3549 version = 3; 3550 break; 3551 default: 3552 g_assert_not_reached(); 3553 } 3554 } else { 3555 version = 3; 3556 } 3557 3558 if (qcow2_opts->has_cluster_size) { 3559 cluster_size = qcow2_opts->cluster_size; 3560 } else { 3561 cluster_size = DEFAULT_CLUSTER_SIZE; 3562 } 3563 3564 if (!qcow2_opts->has_extended_l2) { 3565 qcow2_opts->extended_l2 = false; 3566 } 3567 if (qcow2_opts->extended_l2) { 3568 if (version < 3) { 3569 error_setg(errp, "Extended L2 entries are only supported with " 3570 "compatibility level 1.1 and above (use version=v3 or " 3571 "greater)"); 3572 ret = -EINVAL; 3573 goto out; 3574 } 3575 } 3576 3577 if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) { 3578 ret = -EINVAL; 3579 goto out; 3580 } 3581 3582 if (!qcow2_opts->has_preallocation) { 3583 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3584 } 3585 if (qcow2_opts->backing_file && 3586 qcow2_opts->preallocation != PREALLOC_MODE_OFF && 3587 !qcow2_opts->extended_l2) 3588 { 3589 error_setg(errp, "Backing file and preallocation can only be used at " 3590 "the same time if extended_l2 is on"); 3591 ret = -EINVAL; 3592 goto out; 3593 } 3594 if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) { 3595 error_setg(errp, "Backing format cannot be used without backing file"); 3596 ret = -EINVAL; 3597 goto out; 3598 } 3599 3600 if (!qcow2_opts->has_lazy_refcounts) { 3601 qcow2_opts->lazy_refcounts = false; 3602 } 3603 if (version < 3 && qcow2_opts->lazy_refcounts) { 3604 error_setg(errp, "Lazy refcounts only supported with compatibility " 3605 "level 1.1 and above (use version=v3 or greater)"); 3606 ret = -EINVAL; 3607 goto out; 3608 } 3609 3610 if (!qcow2_opts->has_refcount_bits) { 3611 qcow2_opts->refcount_bits = 16; 3612 } 3613 if (qcow2_opts->refcount_bits > 64 || 3614 !is_power_of_2(qcow2_opts->refcount_bits)) 3615 { 3616 error_setg(errp, "Refcount width must be a power of two and may not " 3617 "exceed 64 bits"); 3618 ret = -EINVAL; 3619 goto out; 3620 } 3621 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3622 error_setg(errp, "Different refcount widths than 16 bits require " 3623 "compatibility level 1.1 or above (use version=v3 or " 3624 "greater)"); 3625 ret = -EINVAL; 3626 goto out; 3627 } 3628 refcount_order = ctz32(qcow2_opts->refcount_bits); 3629 3630 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3631 error_setg(errp, "data-file-raw requires data-file"); 3632 ret = -EINVAL; 3633 goto out; 3634 } 3635 if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) { 3636 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3637 "the same time"); 3638 ret = -EINVAL; 3639 goto out; 3640 } 3641 if (qcow2_opts->data_file_raw && 3642 qcow2_opts->preallocation == PREALLOC_MODE_OFF) 3643 { 3644 /* 3645 * data-file-raw means that "the external data file can be 3646 * read as a consistent standalone raw image without looking 3647 * at the qcow2 metadata." It does not say that the metadata 3648 * must be ignored, though (and the qcow2 driver in fact does 3649 * not ignore it), so the L1/L2 tables must be present and 3650 * give a 1:1 mapping, so you get the same result regardless 3651 * of whether you look at the metadata or whether you ignore 3652 * it. 3653 */ 3654 qcow2_opts->preallocation = PREALLOC_MODE_METADATA; 3655 3656 /* 3657 * Cannot use preallocation with backing files, but giving a 3658 * backing file when specifying data_file_raw is an error 3659 * anyway. 3660 */ 3661 assert(!qcow2_opts->backing_file); 3662 } 3663 3664 if (qcow2_opts->data_file) { 3665 if (version < 3) { 3666 error_setg(errp, "External data files are only supported with " 3667 "compatibility level 1.1 and above (use version=v3 or " 3668 "greater)"); 3669 ret = -EINVAL; 3670 goto out; 3671 } 3672 data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp); 3673 if (data_bs == NULL) { 3674 ret = -EIO; 3675 goto out; 3676 } 3677 } 3678 3679 if (qcow2_opts->has_compression_type && 3680 qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3681 3682 ret = -EINVAL; 3683 3684 if (version < 3) { 3685 error_setg(errp, "Non-zlib compression type is only supported with " 3686 "compatibility level 1.1 and above (use version=v3 or " 3687 "greater)"); 3688 goto out; 3689 } 3690 3691 switch (qcow2_opts->compression_type) { 3692 #ifdef CONFIG_ZSTD 3693 case QCOW2_COMPRESSION_TYPE_ZSTD: 3694 break; 3695 #endif 3696 default: 3697 error_setg(errp, "Unknown compression type"); 3698 goto out; 3699 } 3700 3701 compression_type = qcow2_opts->compression_type; 3702 } 3703 3704 /* Create BlockBackend to write to the image */ 3705 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 3706 errp); 3707 if (!blk) { 3708 ret = -EPERM; 3709 goto out; 3710 } 3711 blk_set_allow_write_beyond_eof(blk, true); 3712 3713 /* Write the header */ 3714 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3715 header = g_malloc0(cluster_size); 3716 *header = (QCowHeader) { 3717 .magic = cpu_to_be32(QCOW_MAGIC), 3718 .version = cpu_to_be32(version), 3719 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3720 .size = cpu_to_be64(0), 3721 .l1_table_offset = cpu_to_be64(0), 3722 .l1_size = cpu_to_be32(0), 3723 .refcount_table_offset = cpu_to_be64(cluster_size), 3724 .refcount_table_clusters = cpu_to_be32(1), 3725 .refcount_order = cpu_to_be32(refcount_order), 3726 /* don't deal with endianness since compression_type is 1 byte long */ 3727 .compression_type = compression_type, 3728 .header_length = cpu_to_be32(sizeof(*header)), 3729 }; 3730 3731 /* We'll update this to correct value later */ 3732 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3733 3734 if (qcow2_opts->lazy_refcounts) { 3735 header->compatible_features |= 3736 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3737 } 3738 if (data_bs) { 3739 header->incompatible_features |= 3740 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3741 } 3742 if (qcow2_opts->data_file_raw) { 3743 header->autoclear_features |= 3744 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3745 } 3746 if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { 3747 header->incompatible_features |= 3748 cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); 3749 } 3750 3751 if (qcow2_opts->extended_l2) { 3752 header->incompatible_features |= 3753 cpu_to_be64(QCOW2_INCOMPAT_EXTL2); 3754 } 3755 3756 ret = blk_co_pwrite(blk, 0, cluster_size, header, 0); 3757 g_free(header); 3758 if (ret < 0) { 3759 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3760 goto out; 3761 } 3762 3763 /* Write a refcount table with one refcount block */ 3764 refcount_table = g_malloc0(2 * cluster_size); 3765 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3766 ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0); 3767 g_free(refcount_table); 3768 3769 if (ret < 0) { 3770 error_setg_errno(errp, -ret, "Could not write refcount table"); 3771 goto out; 3772 } 3773 3774 blk_co_unref(blk); 3775 blk = NULL; 3776 3777 /* 3778 * And now open the image and make it consistent first (i.e. increase the 3779 * refcount of the cluster that is occupied by the header and the refcount 3780 * table) 3781 */ 3782 options = qdict_new(); 3783 qdict_put_str(options, "driver", "qcow2"); 3784 qdict_put_str(options, "file", bs->node_name); 3785 if (data_bs) { 3786 qdict_put_str(options, "data-file", data_bs->node_name); 3787 } 3788 blk = blk_co_new_open(NULL, NULL, options, 3789 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3790 errp); 3791 if (blk == NULL) { 3792 ret = -EIO; 3793 goto out; 3794 } 3795 3796 bdrv_graph_co_rdlock(); 3797 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3798 if (ret < 0) { 3799 bdrv_graph_co_rdunlock(); 3800 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3801 "header and refcount table"); 3802 goto out; 3803 3804 } else if (ret != 0) { 3805 error_report("Huh, first cluster in empty image is already in use?"); 3806 abort(); 3807 } 3808 3809 /* Set the external data file if necessary */ 3810 if (data_bs) { 3811 BDRVQcow2State *s = blk_bs(blk)->opaque; 3812 s->image_data_file = g_strdup(data_bs->filename); 3813 } 3814 3815 /* Create a full header (including things like feature table) */ 3816 ret = qcow2_update_header(blk_bs(blk)); 3817 bdrv_graph_co_rdunlock(); 3818 3819 if (ret < 0) { 3820 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3821 goto out; 3822 } 3823 3824 /* Okay, now that we have a valid image, let's give it the right size */ 3825 ret = blk_co_truncate(blk, qcow2_opts->size, false, 3826 qcow2_opts->preallocation, 0, errp); 3827 if (ret < 0) { 3828 error_prepend(errp, "Could not resize image: "); 3829 goto out; 3830 } 3831 3832 /* Want a backing file? There you go. */ 3833 if (qcow2_opts->backing_file) { 3834 const char *backing_format = NULL; 3835 3836 if (qcow2_opts->has_backing_fmt) { 3837 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3838 } 3839 3840 bdrv_graph_co_rdlock(); 3841 ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3842 backing_format, false); 3843 bdrv_graph_co_rdunlock(); 3844 3845 if (ret < 0) { 3846 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3847 "with format '%s'", qcow2_opts->backing_file, 3848 backing_format); 3849 goto out; 3850 } 3851 } 3852 3853 /* Want encryption? There you go. */ 3854 if (qcow2_opts->encrypt) { 3855 bdrv_graph_co_rdlock(); 3856 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3857 bdrv_graph_co_rdunlock(); 3858 3859 if (ret < 0) { 3860 goto out; 3861 } 3862 } 3863 3864 blk_co_unref(blk); 3865 blk = NULL; 3866 3867 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3868 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3869 * have to setup decryption context. We're not doing any I/O on the top 3870 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3871 * not have effect. 3872 */ 3873 options = qdict_new(); 3874 qdict_put_str(options, "driver", "qcow2"); 3875 qdict_put_str(options, "file", bs->node_name); 3876 if (data_bs) { 3877 qdict_put_str(options, "data-file", data_bs->node_name); 3878 } 3879 blk = blk_co_new_open(NULL, NULL, options, 3880 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3881 errp); 3882 if (blk == NULL) { 3883 ret = -EIO; 3884 goto out; 3885 } 3886 3887 ret = 0; 3888 out: 3889 blk_co_unref(blk); 3890 bdrv_co_unref(bs); 3891 bdrv_co_unref(data_bs); 3892 return ret; 3893 } 3894 3895 static int coroutine_fn GRAPH_UNLOCKED 3896 qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, 3897 Error **errp) 3898 { 3899 BlockdevCreateOptions *create_options = NULL; 3900 QDict *qdict; 3901 Visitor *v; 3902 BlockDriverState *bs = NULL; 3903 BlockDriverState *data_bs = NULL; 3904 const char *val; 3905 int ret; 3906 3907 /* Only the keyval visitor supports the dotted syntax needed for 3908 * encryption, so go through a QDict before getting a QAPI type. Ignore 3909 * options meant for the protocol layer so that the visitor doesn't 3910 * complain. */ 3911 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3912 true); 3913 3914 /* Handle encryption options */ 3915 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3916 if (val && !strcmp(val, "on")) { 3917 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3918 } else if (val && !strcmp(val, "off")) { 3919 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3920 } 3921 3922 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3923 if (val && !strcmp(val, "aes")) { 3924 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3925 } 3926 3927 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3928 * version=v2/v3 below. */ 3929 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3930 if (val && !strcmp(val, "0.10")) { 3931 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3932 } else if (val && !strcmp(val, "1.1")) { 3933 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3934 } 3935 3936 /* Change legacy command line options into QMP ones */ 3937 static const QDictRenames opt_renames[] = { 3938 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3939 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3940 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3941 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3942 { BLOCK_OPT_EXTL2, "extended-l2" }, 3943 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3944 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3945 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3946 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3947 { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, 3948 { NULL, NULL }, 3949 }; 3950 3951 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3952 ret = -EINVAL; 3953 goto finish; 3954 } 3955 3956 /* Create and open the file (protocol layer) */ 3957 ret = bdrv_co_create_file(filename, opts, errp); 3958 if (ret < 0) { 3959 goto finish; 3960 } 3961 3962 bs = bdrv_co_open(filename, NULL, NULL, 3963 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3964 if (bs == NULL) { 3965 ret = -EIO; 3966 goto finish; 3967 } 3968 3969 /* Create and open an external data file (protocol layer) */ 3970 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3971 if (val) { 3972 ret = bdrv_co_create_file(val, opts, errp); 3973 if (ret < 0) { 3974 goto finish; 3975 } 3976 3977 data_bs = bdrv_co_open(val, NULL, NULL, 3978 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3979 errp); 3980 if (data_bs == NULL) { 3981 ret = -EIO; 3982 goto finish; 3983 } 3984 3985 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3986 qdict_put_str(qdict, "data-file", data_bs->node_name); 3987 } 3988 3989 /* Set 'driver' and 'node' options */ 3990 qdict_put_str(qdict, "driver", "qcow2"); 3991 qdict_put_str(qdict, "file", bs->node_name); 3992 3993 /* Now get the QAPI type BlockdevCreateOptions */ 3994 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3995 if (!v) { 3996 ret = -EINVAL; 3997 goto finish; 3998 } 3999 4000 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 4001 visit_free(v); 4002 if (!create_options) { 4003 ret = -EINVAL; 4004 goto finish; 4005 } 4006 4007 /* Silently round up size */ 4008 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 4009 BDRV_SECTOR_SIZE); 4010 4011 /* Create the qcow2 image (format layer) */ 4012 ret = qcow2_co_create(create_options, errp); 4013 finish: 4014 if (ret < 0) { 4015 bdrv_graph_co_rdlock(); 4016 bdrv_co_delete_file_noerr(bs); 4017 bdrv_co_delete_file_noerr(data_bs); 4018 bdrv_graph_co_rdunlock(); 4019 } else { 4020 ret = 0; 4021 } 4022 4023 qobject_unref(qdict); 4024 bdrv_co_unref(bs); 4025 bdrv_co_unref(data_bs); 4026 qapi_free_BlockdevCreateOptions(create_options); 4027 return ret; 4028 } 4029 4030 4031 static bool coroutine_fn GRAPH_RDLOCK 4032 is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 4033 { 4034 int64_t nr; 4035 int res; 4036 4037 /* Clamp to image length, before checking status of underlying sectors */ 4038 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 4039 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 4040 } 4041 4042 if (!bytes) { 4043 return true; 4044 } 4045 4046 /* 4047 * bdrv_block_status_above doesn't merge different types of zeros, for 4048 * example, zeros which come from the region which is unallocated in 4049 * the whole backing chain, and zeros which come because of a short 4050 * backing file. So, we need a loop. 4051 */ 4052 do { 4053 res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 4054 offset += nr; 4055 bytes -= nr; 4056 } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes); 4057 4058 return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0; 4059 } 4060 4061 static int coroutine_fn GRAPH_RDLOCK 4062 qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, 4063 BdrvRequestFlags flags) 4064 { 4065 int ret; 4066 BDRVQcow2State *s = bs->opaque; 4067 4068 uint32_t head = offset_into_subcluster(s, offset); 4069 uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) - 4070 (offset + bytes); 4071 4072 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 4073 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 4074 tail = 0; 4075 } 4076 4077 if (head || tail) { 4078 uint64_t off; 4079 unsigned int nr; 4080 QCow2SubclusterType type; 4081 4082 assert(head + bytes + tail <= s->subcluster_size); 4083 4084 /* check whether remainder of cluster already reads as zero */ 4085 if (!(is_zero(bs, offset - head, head) && 4086 is_zero(bs, offset + bytes, tail))) { 4087 return -ENOTSUP; 4088 } 4089 4090 qemu_co_mutex_lock(&s->lock); 4091 /* We can have new write after previous check */ 4092 offset -= head; 4093 bytes = s->subcluster_size; 4094 nr = s->subcluster_size; 4095 ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type); 4096 if (ret < 0 || 4097 (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && 4098 type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && 4099 type != QCOW2_SUBCLUSTER_ZERO_PLAIN && 4100 type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) { 4101 qemu_co_mutex_unlock(&s->lock); 4102 return ret < 0 ? ret : -ENOTSUP; 4103 } 4104 } else { 4105 qemu_co_mutex_lock(&s->lock); 4106 } 4107 4108 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 4109 4110 /* Whatever is left can use real zero subclusters */ 4111 ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags); 4112 qemu_co_mutex_unlock(&s->lock); 4113 4114 return ret; 4115 } 4116 4117 static int coroutine_fn GRAPH_RDLOCK 4118 qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) 4119 { 4120 int ret; 4121 BDRVQcow2State *s = bs->opaque; 4122 4123 /* If the image does not support QCOW_OFLAG_ZERO then discarding 4124 * clusters could expose stale data from the backing file. */ 4125 if (s->qcow_version < 3 && bs->backing) { 4126 return -ENOTSUP; 4127 } 4128 4129 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 4130 assert(bytes < s->cluster_size); 4131 /* Ignore partial clusters, except for the special case of the 4132 * complete partial cluster at the end of an unaligned file */ 4133 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 4134 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 4135 return -ENOTSUP; 4136 } 4137 } 4138 4139 qemu_co_mutex_lock(&s->lock); 4140 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 4141 false); 4142 qemu_co_mutex_unlock(&s->lock); 4143 return ret; 4144 } 4145 4146 static int coroutine_fn GRAPH_RDLOCK 4147 qcow2_co_copy_range_from(BlockDriverState *bs, 4148 BdrvChild *src, int64_t src_offset, 4149 BdrvChild *dst, int64_t dst_offset, 4150 int64_t bytes, BdrvRequestFlags read_flags, 4151 BdrvRequestFlags write_flags) 4152 { 4153 BDRVQcow2State *s = bs->opaque; 4154 int ret; 4155 unsigned int cur_bytes; /* number of bytes in current iteration */ 4156 BdrvChild *child = NULL; 4157 BdrvRequestFlags cur_write_flags; 4158 4159 assert(!bs->encrypted); 4160 qemu_co_mutex_lock(&s->lock); 4161 4162 while (bytes != 0) { 4163 uint64_t copy_offset = 0; 4164 QCow2SubclusterType type; 4165 /* prepare next request */ 4166 cur_bytes = MIN(bytes, INT_MAX); 4167 cur_write_flags = write_flags; 4168 4169 ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes, 4170 ©_offset, &type); 4171 if (ret < 0) { 4172 goto out; 4173 } 4174 4175 switch (type) { 4176 case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: 4177 case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: 4178 if (bs->backing && bs->backing->bs) { 4179 int64_t backing_length = bdrv_co_getlength(bs->backing->bs); 4180 if (src_offset >= backing_length) { 4181 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4182 } else { 4183 child = bs->backing; 4184 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 4185 copy_offset = src_offset; 4186 } 4187 } else { 4188 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4189 } 4190 break; 4191 4192 case QCOW2_SUBCLUSTER_ZERO_PLAIN: 4193 case QCOW2_SUBCLUSTER_ZERO_ALLOC: 4194 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 4195 break; 4196 4197 case QCOW2_SUBCLUSTER_COMPRESSED: 4198 ret = -ENOTSUP; 4199 goto out; 4200 4201 case QCOW2_SUBCLUSTER_NORMAL: 4202 child = s->data_file; 4203 break; 4204 4205 default: 4206 abort(); 4207 } 4208 qemu_co_mutex_unlock(&s->lock); 4209 ret = bdrv_co_copy_range_from(child, 4210 copy_offset, 4211 dst, dst_offset, 4212 cur_bytes, read_flags, cur_write_flags); 4213 qemu_co_mutex_lock(&s->lock); 4214 if (ret < 0) { 4215 goto out; 4216 } 4217 4218 bytes -= cur_bytes; 4219 src_offset += cur_bytes; 4220 dst_offset += cur_bytes; 4221 } 4222 ret = 0; 4223 4224 out: 4225 qemu_co_mutex_unlock(&s->lock); 4226 return ret; 4227 } 4228 4229 static int coroutine_fn GRAPH_RDLOCK 4230 qcow2_co_copy_range_to(BlockDriverState *bs, 4231 BdrvChild *src, int64_t src_offset, 4232 BdrvChild *dst, int64_t dst_offset, 4233 int64_t bytes, BdrvRequestFlags read_flags, 4234 BdrvRequestFlags write_flags) 4235 { 4236 BDRVQcow2State *s = bs->opaque; 4237 int ret; 4238 unsigned int cur_bytes; /* number of sectors in current iteration */ 4239 uint64_t host_offset; 4240 QCowL2Meta *l2meta = NULL; 4241 4242 assert(!bs->encrypted); 4243 4244 qemu_co_mutex_lock(&s->lock); 4245 4246 while (bytes != 0) { 4247 4248 l2meta = NULL; 4249 4250 cur_bytes = MIN(bytes, INT_MAX); 4251 4252 /* TODO: 4253 * If src->bs == dst->bs, we could simply copy by incrementing 4254 * the refcnt, without copying user data. 4255 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 4256 ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes, 4257 &host_offset, &l2meta); 4258 if (ret < 0) { 4259 goto fail; 4260 } 4261 4262 ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes, 4263 true); 4264 if (ret < 0) { 4265 goto fail; 4266 } 4267 4268 qemu_co_mutex_unlock(&s->lock); 4269 ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset, 4270 cur_bytes, read_flags, write_flags); 4271 qemu_co_mutex_lock(&s->lock); 4272 if (ret < 0) { 4273 goto fail; 4274 } 4275 4276 ret = qcow2_handle_l2meta(bs, &l2meta, true); 4277 if (ret) { 4278 goto fail; 4279 } 4280 4281 bytes -= cur_bytes; 4282 src_offset += cur_bytes; 4283 dst_offset += cur_bytes; 4284 } 4285 ret = 0; 4286 4287 fail: 4288 qcow2_handle_l2meta(bs, &l2meta, false); 4289 4290 qemu_co_mutex_unlock(&s->lock); 4291 4292 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 4293 4294 return ret; 4295 } 4296 4297 static int coroutine_fn GRAPH_RDLOCK 4298 qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, 4299 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) 4300 { 4301 ERRP_GUARD(); 4302 BDRVQcow2State *s = bs->opaque; 4303 uint64_t old_length; 4304 int64_t new_l1_size; 4305 int ret; 4306 QDict *options; 4307 4308 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 4309 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 4310 { 4311 error_setg(errp, "Unsupported preallocation mode '%s'", 4312 PreallocMode_str(prealloc)); 4313 return -ENOTSUP; 4314 } 4315 4316 if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) { 4317 error_setg(errp, "The new size must be a multiple of %u", 4318 (unsigned) BDRV_SECTOR_SIZE); 4319 return -EINVAL; 4320 } 4321 4322 qemu_co_mutex_lock(&s->lock); 4323 4324 /* 4325 * Even though we store snapshot size for all images, it was not 4326 * required until v3, so it is not safe to proceed for v2. 4327 */ 4328 if (s->nb_snapshots && s->qcow_version < 3) { 4329 error_setg(errp, "Can't resize a v2 image which has snapshots"); 4330 ret = -ENOTSUP; 4331 goto fail; 4332 } 4333 4334 /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */ 4335 if (qcow2_truncate_bitmaps_check(bs, errp)) { 4336 ret = -ENOTSUP; 4337 goto fail; 4338 } 4339 4340 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 4341 new_l1_size = size_to_l1(s, offset); 4342 4343 if (offset < old_length) { 4344 int64_t last_cluster, old_file_size; 4345 if (prealloc != PREALLOC_MODE_OFF) { 4346 error_setg(errp, 4347 "Preallocation can't be used for shrinking an image"); 4348 ret = -EINVAL; 4349 goto fail; 4350 } 4351 4352 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 4353 old_length - ROUND_UP(offset, 4354 s->cluster_size), 4355 QCOW2_DISCARD_ALWAYS, true); 4356 if (ret < 0) { 4357 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 4358 goto fail; 4359 } 4360 4361 ret = qcow2_shrink_l1_table(bs, new_l1_size); 4362 if (ret < 0) { 4363 error_setg_errno(errp, -ret, 4364 "Failed to reduce the number of L2 tables"); 4365 goto fail; 4366 } 4367 4368 ret = qcow2_shrink_reftable(bs); 4369 if (ret < 0) { 4370 error_setg_errno(errp, -ret, 4371 "Failed to discard unused refblocks"); 4372 goto fail; 4373 } 4374 4375 old_file_size = bdrv_co_getlength(bs->file->bs); 4376 if (old_file_size < 0) { 4377 error_setg_errno(errp, -old_file_size, 4378 "Failed to inquire current file length"); 4379 ret = old_file_size; 4380 goto fail; 4381 } 4382 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4383 if (last_cluster < 0) { 4384 error_setg_errno(errp, -last_cluster, 4385 "Failed to find the last cluster"); 4386 ret = last_cluster; 4387 goto fail; 4388 } 4389 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 4390 Error *local_err = NULL; 4391 4392 /* 4393 * Do not pass @exact here: It will not help the user if 4394 * we get an error here just because they wanted to shrink 4395 * their qcow2 image (on a block device) with qemu-img. 4396 * (And on the qcow2 layer, the @exact requirement is 4397 * always fulfilled, so there is no need to pass it on.) 4398 */ 4399 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 4400 false, PREALLOC_MODE_OFF, 0, &local_err); 4401 if (local_err) { 4402 warn_reportf_err(local_err, 4403 "Failed to truncate the tail of the image: "); 4404 } 4405 } 4406 } else { 4407 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 4408 if (ret < 0) { 4409 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 4410 goto fail; 4411 } 4412 4413 if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) { 4414 /* 4415 * When creating a qcow2 image with data-file-raw, we enforce 4416 * at least prealloc=metadata, so that the L1/L2 tables are 4417 * fully allocated and reading from the data file will return 4418 * the same data as reading from the qcow2 image. When the 4419 * image is grown, we must consequently preallocate the 4420 * metadata structures to cover the added area. 4421 */ 4422 prealloc = PREALLOC_MODE_METADATA; 4423 } 4424 } 4425 4426 switch (prealloc) { 4427 case PREALLOC_MODE_OFF: 4428 if (has_data_file(bs)) { 4429 /* 4430 * If the caller wants an exact resize, the external data 4431 * file should be resized to the exact target size, too, 4432 * so we pass @exact here. 4433 */ 4434 ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0, 4435 errp); 4436 if (ret < 0) { 4437 goto fail; 4438 } 4439 } 4440 break; 4441 4442 case PREALLOC_MODE_METADATA: 4443 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4444 if (ret < 0) { 4445 goto fail; 4446 } 4447 break; 4448 4449 case PREALLOC_MODE_FALLOC: 4450 case PREALLOC_MODE_FULL: 4451 { 4452 int64_t allocation_start, host_offset, guest_offset; 4453 int64_t clusters_allocated; 4454 int64_t old_file_size, last_cluster, new_file_size; 4455 uint64_t nb_new_data_clusters, nb_new_l2_tables; 4456 bool subclusters_need_allocation = false; 4457 4458 /* With a data file, preallocation means just allocating the metadata 4459 * and forwarding the truncate request to the data file */ 4460 if (has_data_file(bs)) { 4461 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 4462 if (ret < 0) { 4463 goto fail; 4464 } 4465 break; 4466 } 4467 4468 old_file_size = bdrv_co_getlength(bs->file->bs); 4469 if (old_file_size < 0) { 4470 error_setg_errno(errp, -old_file_size, 4471 "Failed to inquire current file length"); 4472 ret = old_file_size; 4473 goto fail; 4474 } 4475 4476 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 4477 if (last_cluster >= 0) { 4478 old_file_size = (last_cluster + 1) * s->cluster_size; 4479 } else { 4480 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 4481 } 4482 4483 nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) - 4484 start_of_cluster(s, old_length)) >> s->cluster_bits; 4485 4486 /* This is an overestimation; we will not actually allocate space for 4487 * these in the file but just make sure the new refcount structures are 4488 * able to cover them so we will not have to allocate new refblocks 4489 * while entering the data blocks in the potentially new L2 tables. 4490 * (We do not actually care where the L2 tables are placed. Maybe they 4491 * are already allocated or they can be placed somewhere before 4492 * @old_file_size. It does not matter because they will be fully 4493 * allocated automatically, so they do not need to be covered by the 4494 * preallocation. All that matters is that we will not have to allocate 4495 * new refcount structures for them.) */ 4496 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 4497 s->cluster_size / l2_entry_size(s)); 4498 /* The cluster range may not be aligned to L2 boundaries, so add one L2 4499 * table for a potential head/tail */ 4500 nb_new_l2_tables++; 4501 4502 allocation_start = qcow2_refcount_area(bs, old_file_size, 4503 nb_new_data_clusters + 4504 nb_new_l2_tables, 4505 true, 0, 0); 4506 if (allocation_start < 0) { 4507 error_setg_errno(errp, -allocation_start, 4508 "Failed to resize refcount structures"); 4509 ret = allocation_start; 4510 goto fail; 4511 } 4512 4513 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 4514 nb_new_data_clusters); 4515 if (clusters_allocated < 0) { 4516 error_setg_errno(errp, -clusters_allocated, 4517 "Failed to allocate data clusters"); 4518 ret = clusters_allocated; 4519 goto fail; 4520 } 4521 4522 assert(clusters_allocated == nb_new_data_clusters); 4523 4524 /* Allocate the data area */ 4525 new_file_size = allocation_start + 4526 nb_new_data_clusters * s->cluster_size; 4527 /* 4528 * Image file grows, so @exact does not matter. 4529 * 4530 * If we need to zero out the new area, try first whether the protocol 4531 * driver can already take care of this. 4532 */ 4533 if (flags & BDRV_REQ_ZERO_WRITE) { 4534 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 4535 BDRV_REQ_ZERO_WRITE, NULL); 4536 if (ret >= 0) { 4537 flags &= ~BDRV_REQ_ZERO_WRITE; 4538 /* Ensure that we read zeroes and not backing file data */ 4539 subclusters_need_allocation = true; 4540 } 4541 } else { 4542 ret = -1; 4543 } 4544 if (ret < 0) { 4545 ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0, 4546 errp); 4547 } 4548 if (ret < 0) { 4549 error_prepend(errp, "Failed to resize underlying file: "); 4550 qcow2_free_clusters(bs, allocation_start, 4551 nb_new_data_clusters * s->cluster_size, 4552 QCOW2_DISCARD_OTHER); 4553 goto fail; 4554 } 4555 4556 /* Create the necessary L2 entries */ 4557 host_offset = allocation_start; 4558 guest_offset = old_length; 4559 while (nb_new_data_clusters) { 4560 int64_t nb_clusters = MIN( 4561 nb_new_data_clusters, 4562 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 4563 unsigned cow_start_length = offset_into_cluster(s, guest_offset); 4564 QCowL2Meta allocation; 4565 guest_offset = start_of_cluster(s, guest_offset); 4566 allocation = (QCowL2Meta) { 4567 .offset = guest_offset, 4568 .alloc_offset = host_offset, 4569 .nb_clusters = nb_clusters, 4570 .cow_start = { 4571 .offset = 0, 4572 .nb_bytes = cow_start_length, 4573 }, 4574 .cow_end = { 4575 .offset = nb_clusters << s->cluster_bits, 4576 .nb_bytes = 0, 4577 }, 4578 .prealloc = !subclusters_need_allocation, 4579 }; 4580 qemu_co_queue_init(&allocation.dependent_requests); 4581 4582 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 4583 if (ret < 0) { 4584 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 4585 qcow2_free_clusters(bs, host_offset, 4586 nb_new_data_clusters * s->cluster_size, 4587 QCOW2_DISCARD_OTHER); 4588 goto fail; 4589 } 4590 4591 guest_offset += nb_clusters * s->cluster_size; 4592 host_offset += nb_clusters * s->cluster_size; 4593 nb_new_data_clusters -= nb_clusters; 4594 } 4595 break; 4596 } 4597 4598 default: 4599 g_assert_not_reached(); 4600 } 4601 4602 if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { 4603 uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size); 4604 4605 /* 4606 * Use zero clusters as much as we can. qcow2_subcluster_zeroize() 4607 * requires a subcluster-aligned start. The end may be unaligned if 4608 * it is at the end of the image (which it is here). 4609 */ 4610 if (offset > zero_start) { 4611 ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start, 4612 0); 4613 if (ret < 0) { 4614 error_setg_errno(errp, -ret, "Failed to zero out new clusters"); 4615 goto fail; 4616 } 4617 } 4618 4619 /* Write explicit zeros for the unaligned head */ 4620 if (zero_start > old_length) { 4621 uint64_t len = MIN(zero_start, offset) - old_length; 4622 uint8_t *buf = qemu_blockalign0(bs, len); 4623 QEMUIOVector qiov; 4624 qemu_iovec_init_buf(&qiov, buf, len); 4625 4626 qemu_co_mutex_unlock(&s->lock); 4627 ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0); 4628 qemu_co_mutex_lock(&s->lock); 4629 4630 qemu_vfree(buf); 4631 if (ret < 0) { 4632 error_setg_errno(errp, -ret, "Failed to zero out the new area"); 4633 goto fail; 4634 } 4635 } 4636 } 4637 4638 if (prealloc != PREALLOC_MODE_OFF) { 4639 /* Flush metadata before actually changing the image size */ 4640 ret = qcow2_write_caches(bs); 4641 if (ret < 0) { 4642 error_setg_errno(errp, -ret, 4643 "Failed to flush the preallocated area to disk"); 4644 goto fail; 4645 } 4646 } 4647 4648 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 4649 4650 /* write updated header.size */ 4651 offset = cpu_to_be64(offset); 4652 ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size), 4653 sizeof(offset), &offset, 0); 4654 if (ret < 0) { 4655 error_setg_errno(errp, -ret, "Failed to update the image size"); 4656 goto fail; 4657 } 4658 4659 s->l1_vm_state_index = new_l1_size; 4660 4661 /* Update cache sizes */ 4662 options = qdict_clone_shallow(bs->options); 4663 ret = qcow2_update_options(bs, options, s->flags, errp); 4664 qobject_unref(options); 4665 if (ret < 0) { 4666 goto fail; 4667 } 4668 ret = 0; 4669 fail: 4670 qemu_co_mutex_unlock(&s->lock); 4671 return ret; 4672 } 4673 4674 static int coroutine_fn GRAPH_RDLOCK 4675 qcow2_co_pwritev_compressed_task(BlockDriverState *bs, 4676 uint64_t offset, uint64_t bytes, 4677 QEMUIOVector *qiov, size_t qiov_offset) 4678 { 4679 BDRVQcow2State *s = bs->opaque; 4680 int ret; 4681 ssize_t out_len; 4682 uint8_t *buf, *out_buf; 4683 uint64_t cluster_offset; 4684 4685 assert(bytes == s->cluster_size || (bytes < s->cluster_size && 4686 (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))); 4687 4688 buf = qemu_blockalign(bs, s->cluster_size); 4689 if (bytes < s->cluster_size) { 4690 /* Zero-pad last write if image size is not cluster aligned */ 4691 memset(buf + bytes, 0, s->cluster_size - bytes); 4692 } 4693 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); 4694 4695 out_buf = g_malloc(s->cluster_size); 4696 4697 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4698 buf, s->cluster_size); 4699 if (out_len == -ENOMEM) { 4700 /* could not compress: write normal cluster */ 4701 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); 4702 if (ret < 0) { 4703 goto fail; 4704 } 4705 goto success; 4706 } else if (out_len < 0) { 4707 ret = -EINVAL; 4708 goto fail; 4709 } 4710 4711 qemu_co_mutex_lock(&s->lock); 4712 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4713 &cluster_offset); 4714 if (ret < 0) { 4715 qemu_co_mutex_unlock(&s->lock); 4716 goto fail; 4717 } 4718 4719 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4720 qemu_co_mutex_unlock(&s->lock); 4721 if (ret < 0) { 4722 goto fail; 4723 } 4724 4725 BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4726 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); 4727 if (ret < 0) { 4728 goto fail; 4729 } 4730 success: 4731 ret = 0; 4732 fail: 4733 qemu_vfree(buf); 4734 g_free(out_buf); 4735 return ret; 4736 } 4737 4738 /* 4739 * This function can count as GRAPH_RDLOCK because 4740 * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until 4741 * this coroutine has terminated. 4742 */ 4743 static int coroutine_fn GRAPH_RDLOCK 4744 qcow2_co_pwritev_compressed_task_entry(AioTask *task) 4745 { 4746 Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); 4747 4748 assert(!t->subcluster_type && !t->l2meta); 4749 4750 return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov, 4751 t->qiov_offset); 4752 } 4753 4754 /* 4755 * XXX: put compressed sectors first, then all the cluster aligned 4756 * tables to avoid losing bytes in alignment 4757 */ 4758 static int coroutine_fn GRAPH_RDLOCK 4759 qcow2_co_pwritev_compressed_part(BlockDriverState *bs, 4760 int64_t offset, int64_t bytes, 4761 QEMUIOVector *qiov, size_t qiov_offset) 4762 { 4763 BDRVQcow2State *s = bs->opaque; 4764 AioTaskPool *aio = NULL; 4765 int ret = 0; 4766 4767 if (has_data_file(bs)) { 4768 return -ENOTSUP; 4769 } 4770 4771 if (bytes == 0) { 4772 /* 4773 * align end of file to a sector boundary to ease reading with 4774 * sector based I/Os 4775 */ 4776 int64_t len = bdrv_co_getlength(bs->file->bs); 4777 if (len < 0) { 4778 return len; 4779 } 4780 return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0, 4781 NULL); 4782 } 4783 4784 if (offset_into_cluster(s, offset)) { 4785 return -EINVAL; 4786 } 4787 4788 if (offset_into_cluster(s, bytes) && 4789 (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) { 4790 return -EINVAL; 4791 } 4792 4793 while (bytes && aio_task_pool_status(aio) == 0) { 4794 uint64_t chunk_size = MIN(bytes, s->cluster_size); 4795 4796 if (!aio && chunk_size != bytes) { 4797 aio = aio_task_pool_new(QCOW2_MAX_WORKERS); 4798 } 4799 4800 ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry, 4801 0, 0, offset, chunk_size, qiov, qiov_offset, NULL); 4802 if (ret < 0) { 4803 break; 4804 } 4805 qiov_offset += chunk_size; 4806 offset += chunk_size; 4807 bytes -= chunk_size; 4808 } 4809 4810 if (aio) { 4811 aio_task_pool_wait_all(aio); 4812 if (ret == 0) { 4813 ret = aio_task_pool_status(aio); 4814 } 4815 g_free(aio); 4816 } 4817 4818 return ret; 4819 } 4820 4821 static int coroutine_fn GRAPH_RDLOCK 4822 qcow2_co_preadv_compressed(BlockDriverState *bs, 4823 uint64_t l2_entry, 4824 uint64_t offset, 4825 uint64_t bytes, 4826 QEMUIOVector *qiov, 4827 size_t qiov_offset) 4828 { 4829 BDRVQcow2State *s = bs->opaque; 4830 int ret = 0, csize; 4831 uint64_t coffset; 4832 uint8_t *buf, *out_buf; 4833 int offset_in_cluster = offset_into_cluster(s, offset); 4834 4835 qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize); 4836 4837 buf = g_try_malloc(csize); 4838 if (!buf) { 4839 return -ENOMEM; 4840 } 4841 4842 out_buf = qemu_blockalign(bs, s->cluster_size); 4843 4844 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4845 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0); 4846 if (ret < 0) { 4847 goto fail; 4848 } 4849 4850 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4851 ret = -EIO; 4852 goto fail; 4853 } 4854 4855 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); 4856 4857 fail: 4858 qemu_vfree(out_buf); 4859 g_free(buf); 4860 4861 return ret; 4862 } 4863 4864 static int GRAPH_RDLOCK make_completely_empty(BlockDriverState *bs) 4865 { 4866 BDRVQcow2State *s = bs->opaque; 4867 Error *local_err = NULL; 4868 int ret, l1_clusters; 4869 int64_t offset; 4870 uint64_t *new_reftable = NULL; 4871 uint64_t rt_entry, l1_size2; 4872 struct { 4873 uint64_t l1_offset; 4874 uint64_t reftable_offset; 4875 uint32_t reftable_clusters; 4876 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4877 4878 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4879 if (ret < 0) { 4880 goto fail; 4881 } 4882 4883 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4884 if (ret < 0) { 4885 goto fail; 4886 } 4887 4888 /* Refcounts will be broken utterly */ 4889 ret = qcow2_mark_dirty(bs); 4890 if (ret < 0) { 4891 goto fail; 4892 } 4893 4894 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4895 4896 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 4897 l1_size2 = (uint64_t)s->l1_size * L1E_SIZE; 4898 4899 /* After this call, neither the in-memory nor the on-disk refcount 4900 * information accurately describe the actual references */ 4901 4902 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4903 l1_clusters * s->cluster_size, 0); 4904 if (ret < 0) { 4905 goto fail_broken_refcounts; 4906 } 4907 memset(s->l1_table, 0, l1_size2); 4908 4909 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4910 4911 /* Overwrite enough clusters at the beginning of the sectors to place 4912 * the refcount table, a refcount block and the L1 table in; this may 4913 * overwrite parts of the existing refcount and L1 table, which is not 4914 * an issue because the dirty flag is set, complete data loss is in fact 4915 * desired and partial data loss is consequently fine as well */ 4916 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4917 (2 + l1_clusters) * s->cluster_size, 0); 4918 /* This call (even if it failed overall) may have overwritten on-disk 4919 * refcount structures; in that case, the in-memory refcount information 4920 * will probably differ from the on-disk information which makes the BDS 4921 * unusable */ 4922 if (ret < 0) { 4923 goto fail_broken_refcounts; 4924 } 4925 4926 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4927 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4928 4929 /* "Create" an empty reftable (one cluster) directly after the image 4930 * header and an empty L1 table three clusters after the image header; 4931 * the cluster between those two will be used as the first refblock */ 4932 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4933 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4934 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4935 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4936 sizeof(l1_ofs_rt_ofs_cls), &l1_ofs_rt_ofs_cls, 0); 4937 if (ret < 0) { 4938 goto fail_broken_refcounts; 4939 } 4940 4941 s->l1_table_offset = 3 * s->cluster_size; 4942 4943 new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE); 4944 if (!new_reftable) { 4945 ret = -ENOMEM; 4946 goto fail_broken_refcounts; 4947 } 4948 4949 s->refcount_table_offset = s->cluster_size; 4950 s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE; 4951 s->max_refcount_table_index = 0; 4952 4953 g_free(s->refcount_table); 4954 s->refcount_table = new_reftable; 4955 new_reftable = NULL; 4956 4957 /* Now the in-memory refcount information again corresponds to the on-disk 4958 * information (reftable is empty and no refblocks (the refblock cache is 4959 * empty)); however, this means some clusters (e.g. the image header) are 4960 * referenced, but not refcounted, but the normal qcow2 code assumes that 4961 * the in-memory information is always correct */ 4962 4963 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4964 4965 /* Enter the first refblock into the reftable */ 4966 rt_entry = cpu_to_be64(2 * s->cluster_size); 4967 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, sizeof(rt_entry), 4968 &rt_entry, 0); 4969 if (ret < 0) { 4970 goto fail_broken_refcounts; 4971 } 4972 s->refcount_table[0] = 2 * s->cluster_size; 4973 4974 s->free_cluster_index = 0; 4975 assert(3 + l1_clusters <= s->refcount_block_size); 4976 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4977 if (offset < 0) { 4978 ret = offset; 4979 goto fail_broken_refcounts; 4980 } else if (offset > 0) { 4981 error_report("First cluster in emptied image is in use"); 4982 abort(); 4983 } 4984 4985 /* Now finally the in-memory information corresponds to the on-disk 4986 * structures and is correct */ 4987 ret = qcow2_mark_clean(bs); 4988 if (ret < 0) { 4989 goto fail; 4990 } 4991 4992 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false, 4993 PREALLOC_MODE_OFF, 0, &local_err); 4994 if (ret < 0) { 4995 error_report_err(local_err); 4996 goto fail; 4997 } 4998 4999 return 0; 5000 5001 fail_broken_refcounts: 5002 /* The BDS is unusable at this point. If we wanted to make it usable, we 5003 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 5004 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 5005 * again. However, because the functions which could have caused this error 5006 * path to be taken are used by those functions as well, it's very likely 5007 * that that sequence will fail as well. Therefore, just eject the BDS. */ 5008 bs->drv = NULL; 5009 5010 fail: 5011 g_free(new_reftable); 5012 return ret; 5013 } 5014 5015 static int GRAPH_RDLOCK qcow2_make_empty(BlockDriverState *bs) 5016 { 5017 BDRVQcow2State *s = bs->opaque; 5018 uint64_t offset, end_offset; 5019 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 5020 int l1_clusters, ret = 0; 5021 5022 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE); 5023 5024 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 5025 3 + l1_clusters <= s->refcount_block_size && 5026 s->crypt_method_header != QCOW_CRYPT_LUKS && 5027 !has_data_file(bs)) { 5028 /* The following function only works for qcow2 v3 images (it 5029 * requires the dirty flag) and only as long as there are no 5030 * features that reserve extra clusters (such as snapshots, 5031 * LUKS header, or persistent bitmaps), because it completely 5032 * empties the image. Furthermore, the L1 table and three 5033 * additional clusters (image header, refcount table, one 5034 * refcount block) have to fit inside one refcount block. It 5035 * only resets the image file, i.e. does not work with an 5036 * external data file. */ 5037 return make_completely_empty(bs); 5038 } 5039 5040 /* This fallback code simply discards every active cluster; this is slow, 5041 * but works in all cases */ 5042 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 5043 for (offset = 0; offset < end_offset; offset += step) { 5044 /* As this function is generally used after committing an external 5045 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 5046 * default action for this kind of discard is to pass the discard, 5047 * which will ideally result in an actually smaller image file, as 5048 * is probably desired. */ 5049 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 5050 QCOW2_DISCARD_SNAPSHOT, true); 5051 if (ret < 0) { 5052 break; 5053 } 5054 } 5055 5056 return ret; 5057 } 5058 5059 static coroutine_fn GRAPH_RDLOCK int qcow2_co_flush_to_os(BlockDriverState *bs) 5060 { 5061 BDRVQcow2State *s = bs->opaque; 5062 int ret; 5063 5064 qemu_co_mutex_lock(&s->lock); 5065 ret = qcow2_write_caches(bs); 5066 qemu_co_mutex_unlock(&s->lock); 5067 5068 return ret; 5069 } 5070 5071 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 5072 Error **errp) 5073 { 5074 Error *local_err = NULL; 5075 BlockMeasureInfo *info; 5076 uint64_t required = 0; /* bytes that contribute to required size */ 5077 uint64_t virtual_size; /* disk size as seen by guest */ 5078 uint64_t refcount_bits; 5079 uint64_t l2_tables; 5080 uint64_t luks_payload_size = 0; 5081 size_t cluster_size; 5082 int version; 5083 char *optstr; 5084 PreallocMode prealloc; 5085 bool has_backing_file; 5086 bool has_luks; 5087 bool extended_l2; 5088 size_t l2e_size; 5089 5090 /* Parse image creation options */ 5091 extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false); 5092 5093 cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2, 5094 &local_err); 5095 if (local_err) { 5096 goto err; 5097 } 5098 5099 version = qcow2_opt_get_version_del(opts, &local_err); 5100 if (local_err) { 5101 goto err; 5102 } 5103 5104 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 5105 if (local_err) { 5106 goto err; 5107 } 5108 5109 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 5110 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 5111 PREALLOC_MODE_OFF, &local_err); 5112 g_free(optstr); 5113 if (local_err) { 5114 goto err; 5115 } 5116 5117 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 5118 has_backing_file = !!optstr; 5119 g_free(optstr); 5120 5121 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 5122 has_luks = optstr && strcmp(optstr, "luks") == 0; 5123 g_free(optstr); 5124 5125 if (has_luks) { 5126 g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL; 5127 QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp); 5128 size_t headerlen; 5129 5130 create_opts = block_crypto_create_opts_init(cryptoopts, errp); 5131 qobject_unref(cryptoopts); 5132 if (!create_opts) { 5133 goto err; 5134 } 5135 5136 if (!qcrypto_block_calculate_payload_offset(create_opts, 5137 "encrypt.", 5138 &headerlen, 5139 &local_err)) { 5140 goto err; 5141 } 5142 5143 luks_payload_size = ROUND_UP(headerlen, cluster_size); 5144 } 5145 5146 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 5147 virtual_size = ROUND_UP(virtual_size, cluster_size); 5148 5149 /* Check that virtual disk size is valid */ 5150 l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 5151 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 5152 cluster_size / l2e_size); 5153 if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) { 5154 error_setg(&local_err, "The image size is too large " 5155 "(try using a larger cluster size)"); 5156 goto err; 5157 } 5158 5159 /* Account for input image */ 5160 if (in_bs) { 5161 int64_t ssize = bdrv_getlength(in_bs); 5162 if (ssize < 0) { 5163 error_setg_errno(&local_err, -ssize, 5164 "Unable to get image virtual_size"); 5165 goto err; 5166 } 5167 5168 virtual_size = ROUND_UP(ssize, cluster_size); 5169 5170 if (has_backing_file) { 5171 /* We don't how much of the backing chain is shared by the input 5172 * image and the new image file. In the worst case the new image's 5173 * backing file has nothing in common with the input image. Be 5174 * conservative and assume all clusters need to be written. 5175 */ 5176 required = virtual_size; 5177 } else { 5178 int64_t offset; 5179 int64_t pnum = 0; 5180 5181 for (offset = 0; offset < ssize; offset += pnum) { 5182 int ret; 5183 5184 ret = bdrv_block_status_above(in_bs, NULL, offset, 5185 ssize - offset, &pnum, NULL, 5186 NULL); 5187 if (ret < 0) { 5188 error_setg_errno(&local_err, -ret, 5189 "Unable to get block status"); 5190 goto err; 5191 } 5192 5193 if (ret & BDRV_BLOCK_ZERO) { 5194 /* Skip zero regions (safe with no backing file) */ 5195 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 5196 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 5197 /* Extend pnum to end of cluster for next iteration */ 5198 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 5199 5200 /* Count clusters we've seen */ 5201 required += offset % cluster_size + pnum; 5202 } 5203 } 5204 } 5205 } 5206 5207 /* Take into account preallocation. Nothing special is needed for 5208 * PREALLOC_MODE_METADATA since metadata is always counted. 5209 */ 5210 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 5211 required = virtual_size; 5212 } 5213 5214 info = g_new0(BlockMeasureInfo, 1); 5215 info->fully_allocated = luks_payload_size + 5216 qcow2_calc_prealloc_size(virtual_size, cluster_size, 5217 ctz32(refcount_bits), extended_l2); 5218 5219 /* 5220 * Remove data clusters that are not required. This overestimates the 5221 * required size because metadata needed for the fully allocated file is 5222 * still counted. Show bitmaps only if both source and destination 5223 * would support them. 5224 */ 5225 info->required = info->fully_allocated - virtual_size + required; 5226 info->has_bitmaps = version >= 3 && in_bs && 5227 bdrv_supports_persistent_dirty_bitmap(in_bs); 5228 if (info->has_bitmaps) { 5229 info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs, 5230 cluster_size); 5231 } 5232 return info; 5233 5234 err: 5235 error_propagate(errp, local_err); 5236 return NULL; 5237 } 5238 5239 static int coroutine_fn 5240 qcow2_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 5241 { 5242 BDRVQcow2State *s = bs->opaque; 5243 bdi->cluster_size = s->cluster_size; 5244 bdi->subcluster_size = s->subcluster_size; 5245 bdi->vm_state_offset = qcow2_vm_state_offset(s); 5246 bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY; 5247 return 0; 5248 } 5249 5250 static ImageInfoSpecific * GRAPH_RDLOCK 5251 qcow2_get_specific_info(BlockDriverState *bs, Error **errp) 5252 { 5253 BDRVQcow2State *s = bs->opaque; 5254 ImageInfoSpecific *spec_info; 5255 QCryptoBlockInfo *encrypt_info = NULL; 5256 5257 if (s->crypto != NULL) { 5258 encrypt_info = qcrypto_block_get_info(s->crypto, errp); 5259 if (!encrypt_info) { 5260 return NULL; 5261 } 5262 } 5263 5264 spec_info = g_new(ImageInfoSpecific, 1); 5265 *spec_info = (ImageInfoSpecific){ 5266 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 5267 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 5268 }; 5269 if (s->qcow_version == 2) { 5270 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5271 .compat = g_strdup("0.10"), 5272 .refcount_bits = s->refcount_bits, 5273 }; 5274 } else if (s->qcow_version == 3) { 5275 Qcow2BitmapInfoList *bitmaps; 5276 if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) { 5277 qapi_free_ImageInfoSpecific(spec_info); 5278 qapi_free_QCryptoBlockInfo(encrypt_info); 5279 return NULL; 5280 } 5281 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 5282 .compat = g_strdup("1.1"), 5283 .lazy_refcounts = s->compatible_features & 5284 QCOW2_COMPAT_LAZY_REFCOUNTS, 5285 .has_lazy_refcounts = true, 5286 .corrupt = s->incompatible_features & 5287 QCOW2_INCOMPAT_CORRUPT, 5288 .has_corrupt = true, 5289 .has_extended_l2 = true, 5290 .extended_l2 = has_subclusters(s), 5291 .refcount_bits = s->refcount_bits, 5292 .has_bitmaps = !!bitmaps, 5293 .bitmaps = bitmaps, 5294 .data_file = g_strdup(s->image_data_file), 5295 .has_data_file_raw = has_data_file(bs), 5296 .data_file_raw = data_file_is_raw(bs), 5297 .compression_type = s->compression_type, 5298 }; 5299 } else { 5300 /* if this assertion fails, this probably means a new version was 5301 * added without having it covered here */ 5302 assert(false); 5303 } 5304 5305 if (encrypt_info) { 5306 ImageInfoSpecificQCow2Encryption *qencrypt = 5307 g_new(ImageInfoSpecificQCow2Encryption, 1); 5308 switch (encrypt_info->format) { 5309 case QCRYPTO_BLOCK_FORMAT_QCOW: 5310 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 5311 break; 5312 case QCRYPTO_BLOCK_FORMAT_LUKS: 5313 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 5314 qencrypt->u.luks = encrypt_info->u.luks; 5315 break; 5316 default: 5317 abort(); 5318 } 5319 /* Since we did shallow copy above, erase any pointers 5320 * in the original info */ 5321 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 5322 qapi_free_QCryptoBlockInfo(encrypt_info); 5323 5324 spec_info->u.qcow2.data->encrypt = qencrypt; 5325 } 5326 5327 return spec_info; 5328 } 5329 5330 static int coroutine_mixed_fn GRAPH_RDLOCK 5331 qcow2_has_zero_init(BlockDriverState *bs) 5332 { 5333 BDRVQcow2State *s = bs->opaque; 5334 bool preallocated; 5335 5336 if (qemu_in_coroutine()) { 5337 qemu_co_mutex_lock(&s->lock); 5338 } 5339 /* 5340 * Check preallocation status: Preallocated images have all L2 5341 * tables allocated, nonpreallocated images have none. It is 5342 * therefore enough to check the first one. 5343 */ 5344 preallocated = s->l1_size > 0 && s->l1_table[0] != 0; 5345 if (qemu_in_coroutine()) { 5346 qemu_co_mutex_unlock(&s->lock); 5347 } 5348 5349 if (!preallocated) { 5350 return 1; 5351 } else if (bs->encrypted) { 5352 return 0; 5353 } else { 5354 return bdrv_has_zero_init(s->data_file->bs); 5355 } 5356 } 5357 5358 /* 5359 * Check the request to vmstate. On success return 5360 * qcow2_vm_state_offset(bs) + @pos 5361 */ 5362 static int64_t qcow2_check_vmstate_request(BlockDriverState *bs, 5363 QEMUIOVector *qiov, int64_t pos) 5364 { 5365 BDRVQcow2State *s = bs->opaque; 5366 int64_t vmstate_offset = qcow2_vm_state_offset(s); 5367 int ret; 5368 5369 /* Incoming requests must be OK */ 5370 bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort); 5371 5372 if (INT64_MAX - pos < vmstate_offset) { 5373 return -EIO; 5374 } 5375 5376 pos += vmstate_offset; 5377 ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL); 5378 if (ret < 0) { 5379 return ret; 5380 } 5381 5382 return pos; 5383 } 5384 5385 static int coroutine_fn GRAPH_RDLOCK 5386 qcow2_co_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5387 { 5388 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5389 if (offset < 0) { 5390 return offset; 5391 } 5392 5393 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 5394 return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0); 5395 } 5396 5397 static int coroutine_fn GRAPH_RDLOCK 5398 qcow2_co_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) 5399 { 5400 int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos); 5401 if (offset < 0) { 5402 return offset; 5403 } 5404 5405 BLKDBG_CO_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 5406 return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0); 5407 } 5408 5409 static int GRAPH_RDLOCK qcow2_has_compressed_clusters(BlockDriverState *bs) 5410 { 5411 int64_t offset = 0; 5412 int64_t bytes = bdrv_getlength(bs); 5413 5414 if (bytes < 0) { 5415 return bytes; 5416 } 5417 5418 while (bytes != 0) { 5419 int ret; 5420 QCow2SubclusterType type; 5421 unsigned int cur_bytes = MIN(INT_MAX, bytes); 5422 uint64_t host_offset; 5423 5424 ret = qcow2_get_host_offset(bs, offset, &cur_bytes, &host_offset, 5425 &type); 5426 if (ret < 0) { 5427 return ret; 5428 } 5429 5430 if (type == QCOW2_SUBCLUSTER_COMPRESSED) { 5431 return 1; 5432 } 5433 5434 offset += cur_bytes; 5435 bytes -= cur_bytes; 5436 } 5437 5438 return 0; 5439 } 5440 5441 /* 5442 * Downgrades an image's version. To achieve this, any incompatible features 5443 * have to be removed. 5444 */ 5445 static int GRAPH_RDLOCK 5446 qcow2_downgrade(BlockDriverState *bs, int target_version, 5447 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5448 Error **errp) 5449 { 5450 BDRVQcow2State *s = bs->opaque; 5451 int current_version = s->qcow_version; 5452 int ret; 5453 int i; 5454 5455 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 5456 assert(target_version < current_version); 5457 5458 /* There are no other versions (now) that you can downgrade to */ 5459 assert(target_version == 2); 5460 5461 if (s->refcount_order != 4) { 5462 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 5463 return -ENOTSUP; 5464 } 5465 5466 if (has_data_file(bs)) { 5467 error_setg(errp, "Cannot downgrade an image with a data file"); 5468 return -ENOTSUP; 5469 } 5470 5471 /* 5472 * If any internal snapshot has a different size than the current 5473 * image size, or VM state size that exceeds 32 bits, downgrading 5474 * is unsafe. Even though we would still use v3-compliant output 5475 * to preserve that data, other v2 programs might not realize 5476 * those optional fields are important. 5477 */ 5478 for (i = 0; i < s->nb_snapshots; i++) { 5479 if (s->snapshots[i].vm_state_size > UINT32_MAX || 5480 s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) { 5481 error_setg(errp, "Internal snapshots prevent downgrade of image"); 5482 return -ENOTSUP; 5483 } 5484 } 5485 5486 /* clear incompatible features */ 5487 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 5488 ret = qcow2_mark_clean(bs); 5489 if (ret < 0) { 5490 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5491 return ret; 5492 } 5493 } 5494 5495 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 5496 * the first place; if that happens nonetheless, returning -ENOTSUP is the 5497 * best thing to do anyway */ 5498 5499 if (s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION) { 5500 error_setg(errp, "Cannot downgrade an image with incompatible features " 5501 "0x%" PRIx64 " set", 5502 s->incompatible_features & ~QCOW2_INCOMPAT_COMPRESSION); 5503 return -ENOTSUP; 5504 } 5505 5506 /* since we can ignore compatible features, we can set them to 0 as well */ 5507 s->compatible_features = 0; 5508 /* if lazy refcounts have been used, they have already been fixed through 5509 * clearing the dirty flag */ 5510 5511 /* clearing autoclear features is trivial */ 5512 s->autoclear_features = 0; 5513 5514 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 5515 if (ret < 0) { 5516 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 5517 return ret; 5518 } 5519 5520 if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { 5521 ret = qcow2_has_compressed_clusters(bs); 5522 if (ret < 0) { 5523 error_setg(errp, "Failed to check block status"); 5524 return -EINVAL; 5525 } 5526 if (ret) { 5527 error_setg(errp, "Cannot downgrade an image with zstd compression " 5528 "type and existing compressed clusters"); 5529 return -ENOTSUP; 5530 } 5531 /* 5532 * No compressed clusters for now, so just chose default zlib 5533 * compression. 5534 */ 5535 s->incompatible_features &= ~QCOW2_INCOMPAT_COMPRESSION; 5536 s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; 5537 } 5538 5539 assert(s->incompatible_features == 0); 5540 5541 s->qcow_version = target_version; 5542 ret = qcow2_update_header(bs); 5543 if (ret < 0) { 5544 s->qcow_version = current_version; 5545 error_setg_errno(errp, -ret, "Failed to update the image header"); 5546 return ret; 5547 } 5548 return 0; 5549 } 5550 5551 /* 5552 * Upgrades an image's version. While newer versions encompass all 5553 * features of older versions, some things may have to be presented 5554 * differently. 5555 */ 5556 static int GRAPH_RDLOCK 5557 qcow2_upgrade(BlockDriverState *bs, int target_version, 5558 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5559 Error **errp) 5560 { 5561 BDRVQcow2State *s = bs->opaque; 5562 bool need_snapshot_update; 5563 int current_version = s->qcow_version; 5564 int i; 5565 int ret; 5566 5567 /* This is qcow2_upgrade(), not qcow2_downgrade() */ 5568 assert(target_version > current_version); 5569 5570 /* There are no other versions (yet) that you can upgrade to */ 5571 assert(target_version == 3); 5572 5573 status_cb(bs, 0, 2, cb_opaque); 5574 5575 /* 5576 * In v2, snapshots do not need to have extra data. v3 requires 5577 * the 64-bit VM state size and the virtual disk size to be 5578 * present. 5579 * qcow2_write_snapshots() will always write the list in the 5580 * v3-compliant format. 5581 */ 5582 need_snapshot_update = false; 5583 for (i = 0; i < s->nb_snapshots; i++) { 5584 if (s->snapshots[i].extra_data_size < 5585 sizeof_field(QCowSnapshotExtraData, vm_state_size_large) + 5586 sizeof_field(QCowSnapshotExtraData, disk_size)) 5587 { 5588 need_snapshot_update = true; 5589 break; 5590 } 5591 } 5592 if (need_snapshot_update) { 5593 ret = qcow2_write_snapshots(bs); 5594 if (ret < 0) { 5595 error_setg_errno(errp, -ret, "Failed to update the snapshot table"); 5596 return ret; 5597 } 5598 } 5599 status_cb(bs, 1, 2, cb_opaque); 5600 5601 s->qcow_version = target_version; 5602 ret = qcow2_update_header(bs); 5603 if (ret < 0) { 5604 s->qcow_version = current_version; 5605 error_setg_errno(errp, -ret, "Failed to update the image header"); 5606 return ret; 5607 } 5608 status_cb(bs, 2, 2, cb_opaque); 5609 5610 return 0; 5611 } 5612 5613 typedef enum Qcow2AmendOperation { 5614 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 5615 * statically initialized to so that the helper CB can discern the first 5616 * invocation from an operation change */ 5617 QCOW2_NO_OPERATION = 0, 5618 5619 QCOW2_UPGRADING, 5620 QCOW2_UPDATING_ENCRYPTION, 5621 QCOW2_CHANGING_REFCOUNT_ORDER, 5622 QCOW2_DOWNGRADING, 5623 } Qcow2AmendOperation; 5624 5625 typedef struct Qcow2AmendHelperCBInfo { 5626 /* The code coordinating the amend operations should only modify 5627 * these four fields; the rest will be managed by the CB */ 5628 BlockDriverAmendStatusCB *original_status_cb; 5629 void *original_cb_opaque; 5630 5631 Qcow2AmendOperation current_operation; 5632 5633 /* Total number of operations to perform (only set once) */ 5634 int total_operations; 5635 5636 /* The following fields are managed by the CB */ 5637 5638 /* Number of operations completed */ 5639 int operations_completed; 5640 5641 /* Cumulative offset of all completed operations */ 5642 int64_t offset_completed; 5643 5644 Qcow2AmendOperation last_operation; 5645 int64_t last_work_size; 5646 } Qcow2AmendHelperCBInfo; 5647 5648 static void qcow2_amend_helper_cb(BlockDriverState *bs, 5649 int64_t operation_offset, 5650 int64_t operation_work_size, void *opaque) 5651 { 5652 Qcow2AmendHelperCBInfo *info = opaque; 5653 int64_t current_work_size; 5654 int64_t projected_work_size; 5655 5656 if (info->current_operation != info->last_operation) { 5657 if (info->last_operation != QCOW2_NO_OPERATION) { 5658 info->offset_completed += info->last_work_size; 5659 info->operations_completed++; 5660 } 5661 5662 info->last_operation = info->current_operation; 5663 } 5664 5665 assert(info->total_operations > 0); 5666 assert(info->operations_completed < info->total_operations); 5667 5668 info->last_work_size = operation_work_size; 5669 5670 current_work_size = info->offset_completed + operation_work_size; 5671 5672 /* current_work_size is the total work size for (operations_completed + 1) 5673 * operations (which includes this one), so multiply it by the number of 5674 * operations not covered and divide it by the number of operations 5675 * covered to get a projection for the operations not covered */ 5676 projected_work_size = current_work_size * (info->total_operations - 5677 info->operations_completed - 1) 5678 / (info->operations_completed + 1); 5679 5680 info->original_status_cb(bs, info->offset_completed + operation_offset, 5681 current_work_size + projected_work_size, 5682 info->original_cb_opaque); 5683 } 5684 5685 static int GRAPH_RDLOCK 5686 qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 5687 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 5688 bool force, Error **errp) 5689 { 5690 BDRVQcow2State *s = bs->opaque; 5691 int old_version = s->qcow_version, new_version = old_version; 5692 uint64_t new_size = 0; 5693 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 5694 bool lazy_refcounts = s->use_lazy_refcounts; 5695 bool data_file_raw = data_file_is_raw(bs); 5696 const char *compat = NULL; 5697 int refcount_bits = s->refcount_bits; 5698 int ret; 5699 QemuOptDesc *desc = opts->list->desc; 5700 Qcow2AmendHelperCBInfo helper_cb_info; 5701 bool encryption_update = false; 5702 5703 while (desc && desc->name) { 5704 if (!qemu_opt_find(opts, desc->name)) { 5705 /* only change explicitly defined options */ 5706 desc++; 5707 continue; 5708 } 5709 5710 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 5711 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 5712 if (!compat) { 5713 /* preserve default */ 5714 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) { 5715 new_version = 2; 5716 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) { 5717 new_version = 3; 5718 } else { 5719 error_setg(errp, "Unknown compatibility level %s", compat); 5720 return -EINVAL; 5721 } 5722 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 5723 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 5724 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 5725 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 5726 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 5727 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 5728 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 5729 if (!s->crypto) { 5730 error_setg(errp, 5731 "Can't amend encryption options - encryption not present"); 5732 return -EINVAL; 5733 } 5734 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5735 error_setg(errp, 5736 "Only LUKS encryption options can be amended"); 5737 return -ENOTSUP; 5738 } 5739 encryption_update = true; 5740 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 5741 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 5742 lazy_refcounts); 5743 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 5744 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 5745 refcount_bits); 5746 5747 if (refcount_bits <= 0 || refcount_bits > 64 || 5748 !is_power_of_2(refcount_bits)) 5749 { 5750 error_setg(errp, "Refcount width must be a power of two and " 5751 "may not exceed 64 bits"); 5752 return -EINVAL; 5753 } 5754 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 5755 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 5756 if (data_file && !has_data_file(bs)) { 5757 error_setg(errp, "data-file can only be set for images that " 5758 "use an external data file"); 5759 return -EINVAL; 5760 } 5761 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 5762 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 5763 data_file_raw); 5764 if (data_file_raw && !data_file_is_raw(bs)) { 5765 error_setg(errp, "data-file-raw cannot be set on existing " 5766 "images"); 5767 return -EINVAL; 5768 } 5769 } else { 5770 /* if this point is reached, this probably means a new option was 5771 * added without having it covered here */ 5772 abort(); 5773 } 5774 5775 desc++; 5776 } 5777 5778 helper_cb_info = (Qcow2AmendHelperCBInfo){ 5779 .original_status_cb = status_cb, 5780 .original_cb_opaque = cb_opaque, 5781 .total_operations = (new_version != old_version) 5782 + (s->refcount_bits != refcount_bits) + 5783 (encryption_update == true) 5784 }; 5785 5786 /* Upgrade first (some features may require compat=1.1) */ 5787 if (new_version > old_version) { 5788 helper_cb_info.current_operation = QCOW2_UPGRADING; 5789 ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb, 5790 &helper_cb_info, errp); 5791 if (ret < 0) { 5792 return ret; 5793 } 5794 } 5795 5796 if (encryption_update) { 5797 QDict *amend_opts_dict; 5798 QCryptoBlockAmendOptions *amend_opts; 5799 5800 helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION; 5801 amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp); 5802 if (!amend_opts_dict) { 5803 return -EINVAL; 5804 } 5805 amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp); 5806 qobject_unref(amend_opts_dict); 5807 if (!amend_opts) { 5808 return -EINVAL; 5809 } 5810 ret = qcrypto_block_amend_options(s->crypto, 5811 qcow2_crypto_hdr_read_func, 5812 qcow2_crypto_hdr_write_func, 5813 bs, 5814 amend_opts, 5815 force, 5816 errp); 5817 qapi_free_QCryptoBlockAmendOptions(amend_opts); 5818 if (ret < 0) { 5819 return ret; 5820 } 5821 } 5822 5823 if (s->refcount_bits != refcount_bits) { 5824 int refcount_order = ctz32(refcount_bits); 5825 5826 if (new_version < 3 && refcount_bits != 16) { 5827 error_setg(errp, "Refcount widths other than 16 bits require " 5828 "compatibility level 1.1 or above (use compat=1.1 or " 5829 "greater)"); 5830 return -EINVAL; 5831 } 5832 5833 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 5834 ret = qcow2_change_refcount_order(bs, refcount_order, 5835 &qcow2_amend_helper_cb, 5836 &helper_cb_info, errp); 5837 if (ret < 0) { 5838 return ret; 5839 } 5840 } 5841 5842 /* data-file-raw blocks backing files, so clear it first if requested */ 5843 if (data_file_raw) { 5844 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5845 } else { 5846 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5847 } 5848 5849 if (data_file) { 5850 g_free(s->image_data_file); 5851 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 5852 } 5853 5854 ret = qcow2_update_header(bs); 5855 if (ret < 0) { 5856 error_setg_errno(errp, -ret, "Failed to update the image header"); 5857 return ret; 5858 } 5859 5860 if (backing_file || backing_format) { 5861 if (g_strcmp0(backing_file, s->image_backing_file) || 5862 g_strcmp0(backing_format, s->image_backing_format)) { 5863 error_setg(errp, "Cannot amend the backing file"); 5864 error_append_hint(errp, 5865 "You can use 'qemu-img rebase' instead.\n"); 5866 return -EINVAL; 5867 } 5868 } 5869 5870 if (s->use_lazy_refcounts != lazy_refcounts) { 5871 if (lazy_refcounts) { 5872 if (new_version < 3) { 5873 error_setg(errp, "Lazy refcounts only supported with " 5874 "compatibility level 1.1 and above (use compat=1.1 " 5875 "or greater)"); 5876 return -EINVAL; 5877 } 5878 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5879 ret = qcow2_update_header(bs); 5880 if (ret < 0) { 5881 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5882 error_setg_errno(errp, -ret, "Failed to update the image header"); 5883 return ret; 5884 } 5885 s->use_lazy_refcounts = true; 5886 } else { 5887 /* make image clean first */ 5888 ret = qcow2_mark_clean(bs); 5889 if (ret < 0) { 5890 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5891 return ret; 5892 } 5893 /* now disallow lazy refcounts */ 5894 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5895 ret = qcow2_update_header(bs); 5896 if (ret < 0) { 5897 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5898 error_setg_errno(errp, -ret, "Failed to update the image header"); 5899 return ret; 5900 } 5901 s->use_lazy_refcounts = false; 5902 } 5903 } 5904 5905 if (new_size) { 5906 BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, 5907 errp); 5908 if (!blk) { 5909 return -EPERM; 5910 } 5911 5912 /* 5913 * Amending image options should ensure that the image has 5914 * exactly the given new values, so pass exact=true here. 5915 */ 5916 ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp); 5917 blk_unref(blk); 5918 if (ret < 0) { 5919 return ret; 5920 } 5921 } 5922 5923 /* Downgrade last (so unsupported features can be removed before) */ 5924 if (new_version < old_version) { 5925 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5926 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5927 &helper_cb_info, errp); 5928 if (ret < 0) { 5929 return ret; 5930 } 5931 } 5932 5933 return 0; 5934 } 5935 5936 static int coroutine_fn qcow2_co_amend(BlockDriverState *bs, 5937 BlockdevAmendOptions *opts, 5938 bool force, 5939 Error **errp) 5940 { 5941 BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2; 5942 BDRVQcow2State *s = bs->opaque; 5943 int ret = 0; 5944 5945 if (qopts->encrypt) { 5946 if (!s->crypto) { 5947 error_setg(errp, "image is not encrypted, can't amend"); 5948 return -EOPNOTSUPP; 5949 } 5950 5951 if (qopts->encrypt->format != QCRYPTO_BLOCK_FORMAT_LUKS) { 5952 error_setg(errp, 5953 "Amend can't be used to change the qcow2 encryption format"); 5954 return -EOPNOTSUPP; 5955 } 5956 5957 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 5958 error_setg(errp, 5959 "Only LUKS encryption options can be amended for qcow2 with blockdev-amend"); 5960 return -EOPNOTSUPP; 5961 } 5962 5963 ret = qcrypto_block_amend_options(s->crypto, 5964 qcow2_crypto_hdr_read_func, 5965 qcow2_crypto_hdr_write_func, 5966 bs, 5967 qopts->encrypt, 5968 force, 5969 errp); 5970 } 5971 return ret; 5972 } 5973 5974 /* 5975 * If offset or size are negative, respectively, they will not be included in 5976 * the BLOCK_IMAGE_CORRUPTED event emitted. 5977 * fatal will be ignored for read-only BDS; corruptions found there will always 5978 * be considered non-fatal. 5979 */ 5980 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5981 int64_t size, const char *message_format, ...) 5982 { 5983 BDRVQcow2State *s = bs->opaque; 5984 const char *node_name; 5985 char *message; 5986 va_list ap; 5987 5988 fatal = fatal && bdrv_is_writable(bs); 5989 5990 if (s->signaled_corruption && 5991 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5992 { 5993 return; 5994 } 5995 5996 va_start(ap, message_format); 5997 message = g_strdup_vprintf(message_format, ap); 5998 va_end(ap); 5999 6000 if (fatal) { 6001 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 6002 "corruption events will be suppressed\n", message); 6003 } else { 6004 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 6005 "corruption events will be suppressed\n", message); 6006 } 6007 6008 node_name = bdrv_get_node_name(bs); 6009 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 6010 *node_name ? node_name : NULL, 6011 message, offset >= 0, offset, 6012 size >= 0, size, 6013 fatal); 6014 g_free(message); 6015 6016 if (fatal) { 6017 qcow2_mark_corrupt(bs); 6018 bs->drv = NULL; /* make BDS unusable */ 6019 } 6020 6021 s->signaled_corruption = true; 6022 } 6023 6024 #define QCOW_COMMON_OPTIONS \ 6025 { \ 6026 .name = BLOCK_OPT_SIZE, \ 6027 .type = QEMU_OPT_SIZE, \ 6028 .help = "Virtual disk size" \ 6029 }, \ 6030 { \ 6031 .name = BLOCK_OPT_COMPAT_LEVEL, \ 6032 .type = QEMU_OPT_STRING, \ 6033 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \ 6034 }, \ 6035 { \ 6036 .name = BLOCK_OPT_BACKING_FILE, \ 6037 .type = QEMU_OPT_STRING, \ 6038 .help = "File name of a base image" \ 6039 }, \ 6040 { \ 6041 .name = BLOCK_OPT_BACKING_FMT, \ 6042 .type = QEMU_OPT_STRING, \ 6043 .help = "Image format of the base image" \ 6044 }, \ 6045 { \ 6046 .name = BLOCK_OPT_DATA_FILE, \ 6047 .type = QEMU_OPT_STRING, \ 6048 .help = "File name of an external data file" \ 6049 }, \ 6050 { \ 6051 .name = BLOCK_OPT_DATA_FILE_RAW, \ 6052 .type = QEMU_OPT_BOOL, \ 6053 .help = "The external data file must stay valid " \ 6054 "as a raw image" \ 6055 }, \ 6056 { \ 6057 .name = BLOCK_OPT_LAZY_REFCOUNTS, \ 6058 .type = QEMU_OPT_BOOL, \ 6059 .help = "Postpone refcount updates", \ 6060 .def_value_str = "off" \ 6061 }, \ 6062 { \ 6063 .name = BLOCK_OPT_REFCOUNT_BITS, \ 6064 .type = QEMU_OPT_NUMBER, \ 6065 .help = "Width of a reference count entry in bits", \ 6066 .def_value_str = "16" \ 6067 } 6068 6069 static QemuOptsList qcow2_create_opts = { 6070 .name = "qcow2-create-opts", 6071 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 6072 .desc = { 6073 { \ 6074 .name = BLOCK_OPT_ENCRYPT, \ 6075 .type = QEMU_OPT_BOOL, \ 6076 .help = "Encrypt the image with format 'aes'. (Deprecated " \ 6077 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \ 6078 }, \ 6079 { \ 6080 .name = BLOCK_OPT_ENCRYPT_FORMAT, \ 6081 .type = QEMU_OPT_STRING, \ 6082 .help = "Encrypt the image, format choices: 'aes', 'luks'", \ 6083 }, \ 6084 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \ 6085 "ID of secret providing qcow AES key or LUKS passphrase"), \ 6086 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \ 6087 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \ 6088 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \ 6089 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \ 6090 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \ 6091 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \ 6092 { \ 6093 .name = BLOCK_OPT_CLUSTER_SIZE, \ 6094 .type = QEMU_OPT_SIZE, \ 6095 .help = "qcow2 cluster size", \ 6096 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \ 6097 }, \ 6098 { \ 6099 .name = BLOCK_OPT_EXTL2, \ 6100 .type = QEMU_OPT_BOOL, \ 6101 .help = "Extended L2 tables", \ 6102 .def_value_str = "off" \ 6103 }, \ 6104 { \ 6105 .name = BLOCK_OPT_PREALLOC, \ 6106 .type = QEMU_OPT_STRING, \ 6107 .help = "Preallocation mode (allowed values: off, " \ 6108 "metadata, falloc, full)" \ 6109 }, \ 6110 { \ 6111 .name = BLOCK_OPT_COMPRESSION_TYPE, \ 6112 .type = QEMU_OPT_STRING, \ 6113 .help = "Compression method used for image cluster " \ 6114 "compression", \ 6115 .def_value_str = "zlib" \ 6116 }, 6117 QCOW_COMMON_OPTIONS, 6118 { /* end of list */ } 6119 } 6120 }; 6121 6122 static QemuOptsList qcow2_amend_opts = { 6123 .name = "qcow2-amend-opts", 6124 .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head), 6125 .desc = { 6126 BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."), 6127 BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."), 6128 BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."), 6129 BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."), 6130 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 6131 QCOW_COMMON_OPTIONS, 6132 { /* end of list */ } 6133 } 6134 }; 6135 6136 static const char *const qcow2_strong_runtime_opts[] = { 6137 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 6138 6139 NULL 6140 }; 6141 6142 BlockDriver bdrv_qcow2 = { 6143 .format_name = "qcow2", 6144 .instance_size = sizeof(BDRVQcow2State), 6145 .bdrv_probe = qcow2_probe, 6146 .bdrv_open = qcow2_open, 6147 .bdrv_close = qcow2_close, 6148 .bdrv_reopen_prepare = qcow2_reopen_prepare, 6149 .bdrv_reopen_commit = qcow2_reopen_commit, 6150 .bdrv_reopen_commit_post = qcow2_reopen_commit_post, 6151 .bdrv_reopen_abort = qcow2_reopen_abort, 6152 .bdrv_join_options = qcow2_join_options, 6153 .bdrv_child_perm = bdrv_default_perms, 6154 .bdrv_co_create_opts = qcow2_co_create_opts, 6155 .bdrv_co_create = qcow2_co_create, 6156 .bdrv_has_zero_init = qcow2_has_zero_init, 6157 .bdrv_co_block_status = qcow2_co_block_status, 6158 6159 .bdrv_co_preadv_part = qcow2_co_preadv_part, 6160 .bdrv_co_pwritev_part = qcow2_co_pwritev_part, 6161 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 6162 6163 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 6164 .bdrv_co_pdiscard = qcow2_co_pdiscard, 6165 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 6166 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 6167 .bdrv_co_truncate = qcow2_co_truncate, 6168 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part, 6169 .bdrv_make_empty = qcow2_make_empty, 6170 6171 .bdrv_snapshot_create = qcow2_snapshot_create, 6172 .bdrv_snapshot_goto = qcow2_snapshot_goto, 6173 .bdrv_snapshot_delete = qcow2_snapshot_delete, 6174 .bdrv_snapshot_list = qcow2_snapshot_list, 6175 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 6176 .bdrv_measure = qcow2_measure, 6177 .bdrv_co_get_info = qcow2_co_get_info, 6178 .bdrv_get_specific_info = qcow2_get_specific_info, 6179 6180 .bdrv_co_save_vmstate = qcow2_co_save_vmstate, 6181 .bdrv_co_load_vmstate = qcow2_co_load_vmstate, 6182 6183 .is_format = true, 6184 .supports_backing = true, 6185 .bdrv_co_change_backing_file = qcow2_co_change_backing_file, 6186 6187 .bdrv_refresh_limits = qcow2_refresh_limits, 6188 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 6189 .bdrv_inactivate = qcow2_inactivate, 6190 6191 .create_opts = &qcow2_create_opts, 6192 .amend_opts = &qcow2_amend_opts, 6193 .strong_runtime_opts = qcow2_strong_runtime_opts, 6194 .mutable_opts = mutable_opts, 6195 .bdrv_co_check = qcow2_co_check, 6196 .bdrv_amend_options = qcow2_amend_options, 6197 .bdrv_co_amend = qcow2_co_amend, 6198 6199 .bdrv_detach_aio_context = qcow2_detach_aio_context, 6200 .bdrv_attach_aio_context = qcow2_attach_aio_context, 6201 6202 .bdrv_supports_persistent_dirty_bitmap = 6203 qcow2_supports_persistent_dirty_bitmap, 6204 .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap, 6205 .bdrv_co_remove_persistent_dirty_bitmap = 6206 qcow2_co_remove_persistent_dirty_bitmap, 6207 }; 6208 6209 static void bdrv_qcow2_init(void) 6210 { 6211 bdrv_register(&bdrv_qcow2); 6212 } 6213 6214 block_init(bdrv_qcow2_init); 6215