1 /* 2 * Block driver for the QCOW version 2 format 3 * 4 * Copyright (c) 2004-2006 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 27 #include "block/qdict.h" 28 #include "sysemu/block-backend.h" 29 #include "qemu/main-loop.h" 30 #include "qemu/module.h" 31 #include "qcow2.h" 32 #include "qemu/error-report.h" 33 #include "qapi/error.h" 34 #include "qapi/qapi-events-block-core.h" 35 #include "qapi/qmp/qdict.h" 36 #include "qapi/qmp/qstring.h" 37 #include "trace.h" 38 #include "qemu/option_int.h" 39 #include "qemu/cutils.h" 40 #include "qemu/bswap.h" 41 #include "qapi/qobject-input-visitor.h" 42 #include "qapi/qapi-visit-block-core.h" 43 #include "crypto.h" 44 45 /* 46 Differences with QCOW: 47 48 - Support for multiple incremental snapshots. 49 - Memory management by reference counts. 50 - Clusters which have a reference count of one have the bit 51 QCOW_OFLAG_COPIED to optimize write performance. 52 - Size of compressed clusters is stored in sectors to reduce bit usage 53 in the cluster offsets. 54 - Support for storing additional data (such as the VM state) in the 55 snapshots. 56 - If a backing store is used, the cluster size is not constrained 57 (could be backported to QCOW). 58 - L2 tables have always a size of one cluster. 59 */ 60 61 62 typedef struct { 63 uint32_t magic; 64 uint32_t len; 65 } QEMU_PACKED QCowExtension; 66 67 #define QCOW2_EXT_MAGIC_END 0 68 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA 69 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 70 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 71 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 72 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 73 74 static int coroutine_fn 75 qcow2_co_preadv_compressed(BlockDriverState *bs, 76 uint64_t file_cluster_offset, 77 uint64_t offset, 78 uint64_t bytes, 79 QEMUIOVector *qiov, 80 size_t qiov_offset); 81 82 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) 83 { 84 const QCowHeader *cow_header = (const void *)buf; 85 86 if (buf_size >= sizeof(QCowHeader) && 87 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 88 be32_to_cpu(cow_header->version) >= 2) 89 return 100; 90 else 91 return 0; 92 } 93 94 95 static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, 96 uint8_t *buf, size_t buflen, 97 void *opaque, Error **errp) 98 { 99 BlockDriverState *bs = opaque; 100 BDRVQcow2State *s = bs->opaque; 101 ssize_t ret; 102 103 if ((offset + buflen) > s->crypto_header.length) { 104 error_setg(errp, "Request for data outside of extension header"); 105 return -1; 106 } 107 108 ret = bdrv_pread(bs->file, 109 s->crypto_header.offset + offset, buf, buflen); 110 if (ret < 0) { 111 error_setg_errno(errp, -ret, "Could not read encryption header"); 112 return -1; 113 } 114 return ret; 115 } 116 117 118 static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, 119 void *opaque, Error **errp) 120 { 121 BlockDriverState *bs = opaque; 122 BDRVQcow2State *s = bs->opaque; 123 int64_t ret; 124 int64_t clusterlen; 125 126 ret = qcow2_alloc_clusters(bs, headerlen); 127 if (ret < 0) { 128 error_setg_errno(errp, -ret, 129 "Cannot allocate cluster for LUKS header size %zu", 130 headerlen); 131 return -1; 132 } 133 134 s->crypto_header.length = headerlen; 135 s->crypto_header.offset = ret; 136 137 /* Zero fill remaining space in cluster so it has predictable 138 * content in case of future spec changes */ 139 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; 140 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); 141 ret = bdrv_pwrite_zeroes(bs->file, 142 ret + headerlen, 143 clusterlen - headerlen, 0); 144 if (ret < 0) { 145 error_setg_errno(errp, -ret, "Could not zero fill encryption header"); 146 return -1; 147 } 148 149 return ret; 150 } 151 152 153 static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, 154 const uint8_t *buf, size_t buflen, 155 void *opaque, Error **errp) 156 { 157 BlockDriverState *bs = opaque; 158 BDRVQcow2State *s = bs->opaque; 159 ssize_t ret; 160 161 if ((offset + buflen) > s->crypto_header.length) { 162 error_setg(errp, "Request for data outside of extension header"); 163 return -1; 164 } 165 166 ret = bdrv_pwrite(bs->file, 167 s->crypto_header.offset + offset, buf, buflen); 168 if (ret < 0) { 169 error_setg_errno(errp, -ret, "Could not read encryption header"); 170 return -1; 171 } 172 return ret; 173 } 174 175 176 /* 177 * read qcow2 extension and fill bs 178 * start reading from start_offset 179 * finish reading upon magic of value 0 or when end_offset reached 180 * unknown magic is skipped (future extension this version knows nothing about) 181 * return 0 upon success, non-0 otherwise 182 */ 183 static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, 184 uint64_t end_offset, void **p_feature_table, 185 int flags, bool *need_update_header, 186 Error **errp) 187 { 188 BDRVQcow2State *s = bs->opaque; 189 QCowExtension ext; 190 uint64_t offset; 191 int ret; 192 Qcow2BitmapHeaderExt bitmaps_ext; 193 194 if (need_update_header != NULL) { 195 *need_update_header = false; 196 } 197 198 #ifdef DEBUG_EXT 199 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); 200 #endif 201 offset = start_offset; 202 while (offset < end_offset) { 203 204 #ifdef DEBUG_EXT 205 /* Sanity check */ 206 if (offset > s->cluster_size) 207 printf("qcow2_read_extension: suspicious offset %lu\n", offset); 208 209 printf("attempting to read extended header in offset %lu\n", offset); 210 #endif 211 212 ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext)); 213 if (ret < 0) { 214 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " 215 "pread fail from offset %" PRIu64, offset); 216 return 1; 217 } 218 ext.magic = be32_to_cpu(ext.magic); 219 ext.len = be32_to_cpu(ext.len); 220 offset += sizeof(ext); 221 #ifdef DEBUG_EXT 222 printf("ext.magic = 0x%x\n", ext.magic); 223 #endif 224 if (offset > end_offset || ext.len > end_offset - offset) { 225 error_setg(errp, "Header extension too large"); 226 return -EINVAL; 227 } 228 229 switch (ext.magic) { 230 case QCOW2_EXT_MAGIC_END: 231 return 0; 232 233 case QCOW2_EXT_MAGIC_BACKING_FORMAT: 234 if (ext.len >= sizeof(bs->backing_format)) { 235 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 236 " too large (>=%zu)", ext.len, 237 sizeof(bs->backing_format)); 238 return 2; 239 } 240 ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len); 241 if (ret < 0) { 242 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " 243 "Could not read format name"); 244 return 3; 245 } 246 bs->backing_format[ext.len] = '\0'; 247 s->image_backing_format = g_strdup(bs->backing_format); 248 #ifdef DEBUG_EXT 249 printf("Qcow2: Got format extension %s\n", bs->backing_format); 250 #endif 251 break; 252 253 case QCOW2_EXT_MAGIC_FEATURE_TABLE: 254 if (p_feature_table != NULL) { 255 void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); 256 ret = bdrv_pread(bs->file, offset , feature_table, ext.len); 257 if (ret < 0) { 258 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " 259 "Could not read table"); 260 return ret; 261 } 262 263 *p_feature_table = feature_table; 264 } 265 break; 266 267 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { 268 unsigned int cflags = 0; 269 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 270 error_setg(errp, "CRYPTO header extension only " 271 "expected with LUKS encryption method"); 272 return -EINVAL; 273 } 274 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { 275 error_setg(errp, "CRYPTO header extension size %u, " 276 "but expected size %zu", ext.len, 277 sizeof(Qcow2CryptoHeaderExtension)); 278 return -EINVAL; 279 } 280 281 ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len); 282 if (ret < 0) { 283 error_setg_errno(errp, -ret, 284 "Unable to read CRYPTO header extension"); 285 return ret; 286 } 287 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 288 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 289 290 if ((s->crypto_header.offset % s->cluster_size) != 0) { 291 error_setg(errp, "Encryption header offset '%" PRIu64 "' is " 292 "not a multiple of cluster size '%u'", 293 s->crypto_header.offset, s->cluster_size); 294 return -EINVAL; 295 } 296 297 if (flags & BDRV_O_NO_IO) { 298 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 299 } 300 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 301 qcow2_crypto_hdr_read_func, 302 bs, cflags, QCOW2_MAX_THREADS, errp); 303 if (!s->crypto) { 304 return -EINVAL; 305 } 306 } break; 307 308 case QCOW2_EXT_MAGIC_BITMAPS: 309 if (ext.len != sizeof(bitmaps_ext)) { 310 error_setg_errno(errp, -ret, "bitmaps_ext: " 311 "Invalid extension length"); 312 return -EINVAL; 313 } 314 315 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { 316 if (s->qcow_version < 3) { 317 /* Let's be a bit more specific */ 318 warn_report("This qcow2 v2 image contains bitmaps, but " 319 "they may have been modified by a program " 320 "without persistent bitmap support; so now " 321 "they must all be considered inconsistent"); 322 } else { 323 warn_report("a program lacking bitmap support " 324 "modified this file, so all bitmaps are now " 325 "considered inconsistent"); 326 } 327 error_printf("Some clusters may be leaked, " 328 "run 'qemu-img check -r' on the image " 329 "file to fix."); 330 if (need_update_header != NULL) { 331 /* Updating is needed to drop invalid bitmap extension. */ 332 *need_update_header = true; 333 } 334 break; 335 } 336 337 ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len); 338 if (ret < 0) { 339 error_setg_errno(errp, -ret, "bitmaps_ext: " 340 "Could not read ext header"); 341 return ret; 342 } 343 344 if (bitmaps_ext.reserved32 != 0) { 345 error_setg_errno(errp, -ret, "bitmaps_ext: " 346 "Reserved field is not zero"); 347 return -EINVAL; 348 } 349 350 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); 351 bitmaps_ext.bitmap_directory_size = 352 be64_to_cpu(bitmaps_ext.bitmap_directory_size); 353 bitmaps_ext.bitmap_directory_offset = 354 be64_to_cpu(bitmaps_ext.bitmap_directory_offset); 355 356 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { 357 error_setg(errp, 358 "bitmaps_ext: Image has %" PRIu32 " bitmaps, " 359 "exceeding the QEMU supported maximum of %d", 360 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); 361 return -EINVAL; 362 } 363 364 if (bitmaps_ext.nb_bitmaps == 0) { 365 error_setg(errp, "found bitmaps extension with zero bitmaps"); 366 return -EINVAL; 367 } 368 369 if (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) { 370 error_setg(errp, "bitmaps_ext: " 371 "invalid bitmap directory offset"); 372 return -EINVAL; 373 } 374 375 if (bitmaps_ext.bitmap_directory_size > 376 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { 377 error_setg(errp, "bitmaps_ext: " 378 "bitmap directory size (%" PRIu64 ") exceeds " 379 "the maximum supported size (%d)", 380 bitmaps_ext.bitmap_directory_size, 381 QCOW2_MAX_BITMAP_DIRECTORY_SIZE); 382 return -EINVAL; 383 } 384 385 s->nb_bitmaps = bitmaps_ext.nb_bitmaps; 386 s->bitmap_directory_offset = 387 bitmaps_ext.bitmap_directory_offset; 388 s->bitmap_directory_size = 389 bitmaps_ext.bitmap_directory_size; 390 391 #ifdef DEBUG_EXT 392 printf("Qcow2: Got bitmaps extension: " 393 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", 394 s->bitmap_directory_offset, s->nb_bitmaps); 395 #endif 396 break; 397 398 case QCOW2_EXT_MAGIC_DATA_FILE: 399 { 400 s->image_data_file = g_malloc0(ext.len + 1); 401 ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len); 402 if (ret < 0) { 403 error_setg_errno(errp, -ret, 404 "ERROR: Could not read data file name"); 405 return ret; 406 } 407 #ifdef DEBUG_EXT 408 printf("Qcow2: Got external data file %s\n", s->image_data_file); 409 #endif 410 break; 411 } 412 413 default: 414 /* unknown magic - save it in case we need to rewrite the header */ 415 /* If you add a new feature, make sure to also update the fast 416 * path of qcow2_make_empty() to deal with it. */ 417 { 418 Qcow2UnknownHeaderExtension *uext; 419 420 uext = g_malloc0(sizeof(*uext) + ext.len); 421 uext->magic = ext.magic; 422 uext->len = ext.len; 423 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); 424 425 ret = bdrv_pread(bs->file, offset , uext->data, uext->len); 426 if (ret < 0) { 427 error_setg_errno(errp, -ret, "ERROR: unknown extension: " 428 "Could not read data"); 429 return ret; 430 } 431 } 432 break; 433 } 434 435 offset += ((ext.len + 7) & ~7); 436 } 437 438 return 0; 439 } 440 441 static void cleanup_unknown_header_ext(BlockDriverState *bs) 442 { 443 BDRVQcow2State *s = bs->opaque; 444 Qcow2UnknownHeaderExtension *uext, *next; 445 446 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { 447 QLIST_REMOVE(uext, next); 448 g_free(uext); 449 } 450 } 451 452 static void report_unsupported_feature(Error **errp, Qcow2Feature *table, 453 uint64_t mask) 454 { 455 char *features = g_strdup(""); 456 char *old; 457 458 while (table && table->name[0] != '\0') { 459 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { 460 if (mask & (1ULL << table->bit)) { 461 old = features; 462 features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", 463 table->name); 464 g_free(old); 465 mask &= ~(1ULL << table->bit); 466 } 467 } 468 table++; 469 } 470 471 if (mask) { 472 old = features; 473 features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, 474 old, *old ? ", " : "", mask); 475 g_free(old); 476 } 477 478 error_setg(errp, "Unsupported qcow2 feature(s): %s", features); 479 g_free(features); 480 } 481 482 /* 483 * Sets the dirty bit and flushes afterwards if necessary. 484 * 485 * The incompatible_features bit is only set if the image file header was 486 * updated successfully. Therefore it is not required to check the return 487 * value of this function. 488 */ 489 int qcow2_mark_dirty(BlockDriverState *bs) 490 { 491 BDRVQcow2State *s = bs->opaque; 492 uint64_t val; 493 int ret; 494 495 assert(s->qcow_version >= 3); 496 497 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 498 return 0; /* already dirty */ 499 } 500 501 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); 502 ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), 503 &val, sizeof(val)); 504 if (ret < 0) { 505 return ret; 506 } 507 ret = bdrv_flush(bs->file->bs); 508 if (ret < 0) { 509 return ret; 510 } 511 512 /* Only treat image as dirty if the header was updated successfully */ 513 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; 514 return 0; 515 } 516 517 /* 518 * Clears the dirty bit and flushes before if necessary. Only call this 519 * function when there are no pending requests, it does not guard against 520 * concurrent requests dirtying the image. 521 */ 522 static int qcow2_mark_clean(BlockDriverState *bs) 523 { 524 BDRVQcow2State *s = bs->opaque; 525 526 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 527 int ret; 528 529 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; 530 531 ret = qcow2_flush_caches(bs); 532 if (ret < 0) { 533 return ret; 534 } 535 536 return qcow2_update_header(bs); 537 } 538 return 0; 539 } 540 541 /* 542 * Marks the image as corrupt. 543 */ 544 int qcow2_mark_corrupt(BlockDriverState *bs) 545 { 546 BDRVQcow2State *s = bs->opaque; 547 548 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; 549 return qcow2_update_header(bs); 550 } 551 552 /* 553 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes 554 * before if necessary. 555 */ 556 int qcow2_mark_consistent(BlockDriverState *bs) 557 { 558 BDRVQcow2State *s = bs->opaque; 559 560 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 561 int ret = qcow2_flush_caches(bs); 562 if (ret < 0) { 563 return ret; 564 } 565 566 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; 567 return qcow2_update_header(bs); 568 } 569 return 0; 570 } 571 572 static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs, 573 BdrvCheckResult *result, 574 BdrvCheckMode fix) 575 { 576 int ret = qcow2_check_refcounts(bs, result, fix); 577 if (ret < 0) { 578 return ret; 579 } 580 581 if (fix && result->check_errors == 0 && result->corruptions == 0) { 582 ret = qcow2_mark_clean(bs); 583 if (ret < 0) { 584 return ret; 585 } 586 return qcow2_mark_consistent(bs); 587 } 588 return ret; 589 } 590 591 static int coroutine_fn qcow2_co_check(BlockDriverState *bs, 592 BdrvCheckResult *result, 593 BdrvCheckMode fix) 594 { 595 BDRVQcow2State *s = bs->opaque; 596 int ret; 597 598 qemu_co_mutex_lock(&s->lock); 599 ret = qcow2_co_check_locked(bs, result, fix); 600 qemu_co_mutex_unlock(&s->lock); 601 return ret; 602 } 603 604 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 605 uint64_t entries, size_t entry_len, 606 int64_t max_size_bytes, const char *table_name, 607 Error **errp) 608 { 609 BDRVQcow2State *s = bs->opaque; 610 611 if (entries > max_size_bytes / entry_len) { 612 error_setg(errp, "%s too large", table_name); 613 return -EFBIG; 614 } 615 616 /* Use signed INT64_MAX as the maximum even for uint64_t header fields, 617 * because values will be passed to qemu functions taking int64_t. */ 618 if ((INT64_MAX - entries * entry_len < offset) || 619 (offset_into_cluster(s, offset) != 0)) { 620 error_setg(errp, "%s offset invalid", table_name); 621 return -EINVAL; 622 } 623 624 return 0; 625 } 626 627 static const char *const mutable_opts[] = { 628 QCOW2_OPT_LAZY_REFCOUNTS, 629 QCOW2_OPT_DISCARD_REQUEST, 630 QCOW2_OPT_DISCARD_SNAPSHOT, 631 QCOW2_OPT_DISCARD_OTHER, 632 QCOW2_OPT_OVERLAP, 633 QCOW2_OPT_OVERLAP_TEMPLATE, 634 QCOW2_OPT_OVERLAP_MAIN_HEADER, 635 QCOW2_OPT_OVERLAP_ACTIVE_L1, 636 QCOW2_OPT_OVERLAP_ACTIVE_L2, 637 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 638 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 639 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 640 QCOW2_OPT_OVERLAP_INACTIVE_L1, 641 QCOW2_OPT_OVERLAP_INACTIVE_L2, 642 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 643 QCOW2_OPT_CACHE_SIZE, 644 QCOW2_OPT_L2_CACHE_SIZE, 645 QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 646 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 647 QCOW2_OPT_CACHE_CLEAN_INTERVAL, 648 NULL 649 }; 650 651 static QemuOptsList qcow2_runtime_opts = { 652 .name = "qcow2", 653 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), 654 .desc = { 655 { 656 .name = QCOW2_OPT_LAZY_REFCOUNTS, 657 .type = QEMU_OPT_BOOL, 658 .help = "Postpone refcount updates", 659 }, 660 { 661 .name = QCOW2_OPT_DISCARD_REQUEST, 662 .type = QEMU_OPT_BOOL, 663 .help = "Pass guest discard requests to the layer below", 664 }, 665 { 666 .name = QCOW2_OPT_DISCARD_SNAPSHOT, 667 .type = QEMU_OPT_BOOL, 668 .help = "Generate discard requests when snapshot related space " 669 "is freed", 670 }, 671 { 672 .name = QCOW2_OPT_DISCARD_OTHER, 673 .type = QEMU_OPT_BOOL, 674 .help = "Generate discard requests when other clusters are freed", 675 }, 676 { 677 .name = QCOW2_OPT_OVERLAP, 678 .type = QEMU_OPT_STRING, 679 .help = "Selects which overlap checks to perform from a range of " 680 "templates (none, constant, cached, all)", 681 }, 682 { 683 .name = QCOW2_OPT_OVERLAP_TEMPLATE, 684 .type = QEMU_OPT_STRING, 685 .help = "Selects which overlap checks to perform from a range of " 686 "templates (none, constant, cached, all)", 687 }, 688 { 689 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, 690 .type = QEMU_OPT_BOOL, 691 .help = "Check for unintended writes into the main qcow2 header", 692 }, 693 { 694 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, 695 .type = QEMU_OPT_BOOL, 696 .help = "Check for unintended writes into the active L1 table", 697 }, 698 { 699 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, 700 .type = QEMU_OPT_BOOL, 701 .help = "Check for unintended writes into an active L2 table", 702 }, 703 { 704 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 705 .type = QEMU_OPT_BOOL, 706 .help = "Check for unintended writes into the refcount table", 707 }, 708 { 709 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 710 .type = QEMU_OPT_BOOL, 711 .help = "Check for unintended writes into a refcount block", 712 }, 713 { 714 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 715 .type = QEMU_OPT_BOOL, 716 .help = "Check for unintended writes into the snapshot table", 717 }, 718 { 719 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, 720 .type = QEMU_OPT_BOOL, 721 .help = "Check for unintended writes into an inactive L1 table", 722 }, 723 { 724 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, 725 .type = QEMU_OPT_BOOL, 726 .help = "Check for unintended writes into an inactive L2 table", 727 }, 728 { 729 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 730 .type = QEMU_OPT_BOOL, 731 .help = "Check for unintended writes into the bitmap directory", 732 }, 733 { 734 .name = QCOW2_OPT_CACHE_SIZE, 735 .type = QEMU_OPT_SIZE, 736 .help = "Maximum combined metadata (L2 tables and refcount blocks) " 737 "cache size", 738 }, 739 { 740 .name = QCOW2_OPT_L2_CACHE_SIZE, 741 .type = QEMU_OPT_SIZE, 742 .help = "Maximum L2 table cache size", 743 }, 744 { 745 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 746 .type = QEMU_OPT_SIZE, 747 .help = "Size of each entry in the L2 cache", 748 }, 749 { 750 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, 751 .type = QEMU_OPT_SIZE, 752 .help = "Maximum refcount block cache size", 753 }, 754 { 755 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, 756 .type = QEMU_OPT_NUMBER, 757 .help = "Clean unused cache entries after this time (in seconds)", 758 }, 759 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 760 "ID of secret providing qcow2 AES key or LUKS passphrase"), 761 { /* end of list */ } 762 }, 763 }; 764 765 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { 766 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, 767 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, 768 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, 769 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 770 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 771 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 772 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, 773 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, 774 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 775 }; 776 777 static void cache_clean_timer_cb(void *opaque) 778 { 779 BlockDriverState *bs = opaque; 780 BDRVQcow2State *s = bs->opaque; 781 qcow2_cache_clean_unused(s->l2_table_cache); 782 qcow2_cache_clean_unused(s->refcount_block_cache); 783 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 784 (int64_t) s->cache_clean_interval * 1000); 785 } 786 787 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) 788 { 789 BDRVQcow2State *s = bs->opaque; 790 if (s->cache_clean_interval > 0) { 791 s->cache_clean_timer = aio_timer_new(context, QEMU_CLOCK_VIRTUAL, 792 SCALE_MS, cache_clean_timer_cb, 793 bs); 794 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 795 (int64_t) s->cache_clean_interval * 1000); 796 } 797 } 798 799 static void cache_clean_timer_del(BlockDriverState *bs) 800 { 801 BDRVQcow2State *s = bs->opaque; 802 if (s->cache_clean_timer) { 803 timer_del(s->cache_clean_timer); 804 timer_free(s->cache_clean_timer); 805 s->cache_clean_timer = NULL; 806 } 807 } 808 809 static void qcow2_detach_aio_context(BlockDriverState *bs) 810 { 811 cache_clean_timer_del(bs); 812 } 813 814 static void qcow2_attach_aio_context(BlockDriverState *bs, 815 AioContext *new_context) 816 { 817 cache_clean_timer_init(bs, new_context); 818 } 819 820 static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, 821 uint64_t *l2_cache_size, 822 uint64_t *l2_cache_entry_size, 823 uint64_t *refcount_cache_size, Error **errp) 824 { 825 BDRVQcow2State *s = bs->opaque; 826 uint64_t combined_cache_size, l2_cache_max_setting; 827 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; 828 bool l2_cache_entry_size_set; 829 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; 830 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; 831 uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); 832 /* An L2 table is always one cluster in size so the max cache size 833 * should be a multiple of the cluster size. */ 834 uint64_t max_l2_cache = ROUND_UP(max_l2_entries * sizeof(uint64_t), 835 s->cluster_size); 836 837 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); 838 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); 839 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 840 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); 841 842 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); 843 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 844 DEFAULT_L2_CACHE_MAX_SIZE); 845 *refcount_cache_size = qemu_opt_get_size(opts, 846 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); 847 848 *l2_cache_entry_size = qemu_opt_get_size( 849 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); 850 851 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); 852 853 if (combined_cache_size_set) { 854 if (l2_cache_size_set && refcount_cache_size_set) { 855 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE 856 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " 857 "at the same time"); 858 return; 859 } else if (l2_cache_size_set && 860 (l2_cache_max_setting > combined_cache_size)) { 861 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " 862 QCOW2_OPT_CACHE_SIZE); 863 return; 864 } else if (*refcount_cache_size > combined_cache_size) { 865 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " 866 QCOW2_OPT_CACHE_SIZE); 867 return; 868 } 869 870 if (l2_cache_size_set) { 871 *refcount_cache_size = combined_cache_size - *l2_cache_size; 872 } else if (refcount_cache_size_set) { 873 *l2_cache_size = combined_cache_size - *refcount_cache_size; 874 } else { 875 /* Assign as much memory as possible to the L2 cache, and 876 * use the remainder for the refcount cache */ 877 if (combined_cache_size >= max_l2_cache + min_refcount_cache) { 878 *l2_cache_size = max_l2_cache; 879 *refcount_cache_size = combined_cache_size - *l2_cache_size; 880 } else { 881 *refcount_cache_size = 882 MIN(combined_cache_size, min_refcount_cache); 883 *l2_cache_size = combined_cache_size - *refcount_cache_size; 884 } 885 } 886 } 887 888 /* 889 * If the L2 cache is not enough to cover the whole disk then 890 * default to 4KB entries. Smaller entries reduce the cost of 891 * loads and evictions and increase I/O performance. 892 */ 893 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { 894 *l2_cache_entry_size = MIN(s->cluster_size, 4096); 895 } 896 897 /* l2_cache_size and refcount_cache_size are ensured to have at least 898 * their minimum values in qcow2_update_options_prepare() */ 899 900 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || 901 *l2_cache_entry_size > s->cluster_size || 902 !is_power_of_2(*l2_cache_entry_size)) { 903 error_setg(errp, "L2 cache entry size must be a power of two " 904 "between %d and the cluster size (%d)", 905 1 << MIN_CLUSTER_BITS, s->cluster_size); 906 return; 907 } 908 } 909 910 typedef struct Qcow2ReopenState { 911 Qcow2Cache *l2_table_cache; 912 Qcow2Cache *refcount_block_cache; 913 int l2_slice_size; /* Number of entries in a slice of the L2 table */ 914 bool use_lazy_refcounts; 915 int overlap_check; 916 bool discard_passthrough[QCOW2_DISCARD_MAX]; 917 uint64_t cache_clean_interval; 918 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 919 } Qcow2ReopenState; 920 921 static int qcow2_update_options_prepare(BlockDriverState *bs, 922 Qcow2ReopenState *r, 923 QDict *options, int flags, 924 Error **errp) 925 { 926 BDRVQcow2State *s = bs->opaque; 927 QemuOpts *opts = NULL; 928 const char *opt_overlap_check, *opt_overlap_check_template; 929 int overlap_check_template = 0; 930 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; 931 int i; 932 const char *encryptfmt; 933 QDict *encryptopts = NULL; 934 Error *local_err = NULL; 935 int ret; 936 937 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 938 encryptfmt = qdict_get_try_str(encryptopts, "format"); 939 940 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); 941 qemu_opts_absorb_qdict(opts, options, &local_err); 942 if (local_err) { 943 error_propagate(errp, local_err); 944 ret = -EINVAL; 945 goto fail; 946 } 947 948 /* get L2 table/refcount block cache size from command line options */ 949 read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, 950 &refcount_cache_size, &local_err); 951 if (local_err) { 952 error_propagate(errp, local_err); 953 ret = -EINVAL; 954 goto fail; 955 } 956 957 l2_cache_size /= l2_cache_entry_size; 958 if (l2_cache_size < MIN_L2_CACHE_SIZE) { 959 l2_cache_size = MIN_L2_CACHE_SIZE; 960 } 961 if (l2_cache_size > INT_MAX) { 962 error_setg(errp, "L2 cache size too big"); 963 ret = -EINVAL; 964 goto fail; 965 } 966 967 refcount_cache_size /= s->cluster_size; 968 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { 969 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; 970 } 971 if (refcount_cache_size > INT_MAX) { 972 error_setg(errp, "Refcount cache size too big"); 973 ret = -EINVAL; 974 goto fail; 975 } 976 977 /* alloc new L2 table/refcount block cache, flush old one */ 978 if (s->l2_table_cache) { 979 ret = qcow2_cache_flush(bs, s->l2_table_cache); 980 if (ret) { 981 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); 982 goto fail; 983 } 984 } 985 986 if (s->refcount_block_cache) { 987 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 988 if (ret) { 989 error_setg_errno(errp, -ret, 990 "Failed to flush the refcount block cache"); 991 goto fail; 992 } 993 } 994 995 r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t); 996 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, 997 l2_cache_entry_size); 998 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, 999 s->cluster_size); 1000 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { 1001 error_setg(errp, "Could not allocate metadata caches"); 1002 ret = -ENOMEM; 1003 goto fail; 1004 } 1005 1006 /* New interval for cache cleanup timer */ 1007 r->cache_clean_interval = 1008 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 1009 DEFAULT_CACHE_CLEAN_INTERVAL); 1010 #ifndef CONFIG_LINUX 1011 if (r->cache_clean_interval != 0) { 1012 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL 1013 " not supported on this host"); 1014 ret = -EINVAL; 1015 goto fail; 1016 } 1017 #endif 1018 if (r->cache_clean_interval > UINT_MAX) { 1019 error_setg(errp, "Cache clean interval too big"); 1020 ret = -EINVAL; 1021 goto fail; 1022 } 1023 1024 /* lazy-refcounts; flush if going from enabled to disabled */ 1025 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, 1026 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); 1027 if (r->use_lazy_refcounts && s->qcow_version < 3) { 1028 error_setg(errp, "Lazy refcounts require a qcow2 image with at least " 1029 "qemu 1.1 compatibility level"); 1030 ret = -EINVAL; 1031 goto fail; 1032 } 1033 1034 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { 1035 ret = qcow2_mark_clean(bs); 1036 if (ret < 0) { 1037 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); 1038 goto fail; 1039 } 1040 } 1041 1042 /* Overlap check options */ 1043 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); 1044 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); 1045 if (opt_overlap_check_template && opt_overlap_check && 1046 strcmp(opt_overlap_check_template, opt_overlap_check)) 1047 { 1048 error_setg(errp, "Conflicting values for qcow2 options '" 1049 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE 1050 "' ('%s')", opt_overlap_check, opt_overlap_check_template); 1051 ret = -EINVAL; 1052 goto fail; 1053 } 1054 if (!opt_overlap_check) { 1055 opt_overlap_check = opt_overlap_check_template ?: "cached"; 1056 } 1057 1058 if (!strcmp(opt_overlap_check, "none")) { 1059 overlap_check_template = 0; 1060 } else if (!strcmp(opt_overlap_check, "constant")) { 1061 overlap_check_template = QCOW2_OL_CONSTANT; 1062 } else if (!strcmp(opt_overlap_check, "cached")) { 1063 overlap_check_template = QCOW2_OL_CACHED; 1064 } else if (!strcmp(opt_overlap_check, "all")) { 1065 overlap_check_template = QCOW2_OL_ALL; 1066 } else { 1067 error_setg(errp, "Unsupported value '%s' for qcow2 option " 1068 "'overlap-check'. Allowed are any of the following: " 1069 "none, constant, cached, all", opt_overlap_check); 1070 ret = -EINVAL; 1071 goto fail; 1072 } 1073 1074 r->overlap_check = 0; 1075 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { 1076 /* overlap-check defines a template bitmask, but every flag may be 1077 * overwritten through the associated boolean option */ 1078 r->overlap_check |= 1079 qemu_opt_get_bool(opts, overlap_bool_option_names[i], 1080 overlap_check_template & (1 << i)) << i; 1081 } 1082 1083 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; 1084 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; 1085 r->discard_passthrough[QCOW2_DISCARD_REQUEST] = 1086 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, 1087 flags & BDRV_O_UNMAP); 1088 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = 1089 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); 1090 r->discard_passthrough[QCOW2_DISCARD_OTHER] = 1091 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); 1092 1093 switch (s->crypt_method_header) { 1094 case QCOW_CRYPT_NONE: 1095 if (encryptfmt) { 1096 error_setg(errp, "No encryption in image header, but options " 1097 "specified format '%s'", encryptfmt); 1098 ret = -EINVAL; 1099 goto fail; 1100 } 1101 break; 1102 1103 case QCOW_CRYPT_AES: 1104 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 1105 error_setg(errp, 1106 "Header reported 'aes' encryption format but " 1107 "options specify '%s'", encryptfmt); 1108 ret = -EINVAL; 1109 goto fail; 1110 } 1111 qdict_put_str(encryptopts, "format", "qcow"); 1112 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1113 break; 1114 1115 case QCOW_CRYPT_LUKS: 1116 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { 1117 error_setg(errp, 1118 "Header reported 'luks' encryption format but " 1119 "options specify '%s'", encryptfmt); 1120 ret = -EINVAL; 1121 goto fail; 1122 } 1123 qdict_put_str(encryptopts, "format", "luks"); 1124 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1125 break; 1126 1127 default: 1128 error_setg(errp, "Unsupported encryption method %d", 1129 s->crypt_method_header); 1130 break; 1131 } 1132 if (s->crypt_method_header != QCOW_CRYPT_NONE && !r->crypto_opts) { 1133 ret = -EINVAL; 1134 goto fail; 1135 } 1136 1137 ret = 0; 1138 fail: 1139 qobject_unref(encryptopts); 1140 qemu_opts_del(opts); 1141 opts = NULL; 1142 return ret; 1143 } 1144 1145 static void qcow2_update_options_commit(BlockDriverState *bs, 1146 Qcow2ReopenState *r) 1147 { 1148 BDRVQcow2State *s = bs->opaque; 1149 int i; 1150 1151 if (s->l2_table_cache) { 1152 qcow2_cache_destroy(s->l2_table_cache); 1153 } 1154 if (s->refcount_block_cache) { 1155 qcow2_cache_destroy(s->refcount_block_cache); 1156 } 1157 s->l2_table_cache = r->l2_table_cache; 1158 s->refcount_block_cache = r->refcount_block_cache; 1159 s->l2_slice_size = r->l2_slice_size; 1160 1161 s->overlap_check = r->overlap_check; 1162 s->use_lazy_refcounts = r->use_lazy_refcounts; 1163 1164 for (i = 0; i < QCOW2_DISCARD_MAX; i++) { 1165 s->discard_passthrough[i] = r->discard_passthrough[i]; 1166 } 1167 1168 if (s->cache_clean_interval != r->cache_clean_interval) { 1169 cache_clean_timer_del(bs); 1170 s->cache_clean_interval = r->cache_clean_interval; 1171 cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); 1172 } 1173 1174 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1175 s->crypto_opts = r->crypto_opts; 1176 } 1177 1178 static void qcow2_update_options_abort(BlockDriverState *bs, 1179 Qcow2ReopenState *r) 1180 { 1181 if (r->l2_table_cache) { 1182 qcow2_cache_destroy(r->l2_table_cache); 1183 } 1184 if (r->refcount_block_cache) { 1185 qcow2_cache_destroy(r->refcount_block_cache); 1186 } 1187 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); 1188 } 1189 1190 static int qcow2_update_options(BlockDriverState *bs, QDict *options, 1191 int flags, Error **errp) 1192 { 1193 Qcow2ReopenState r = {}; 1194 int ret; 1195 1196 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); 1197 if (ret >= 0) { 1198 qcow2_update_options_commit(bs, &r); 1199 } else { 1200 qcow2_update_options_abort(bs, &r); 1201 } 1202 1203 return ret; 1204 } 1205 1206 /* Called with s->lock held. */ 1207 static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, 1208 int flags, Error **errp) 1209 { 1210 BDRVQcow2State *s = bs->opaque; 1211 unsigned int len, i; 1212 int ret = 0; 1213 QCowHeader header; 1214 Error *local_err = NULL; 1215 uint64_t ext_end; 1216 uint64_t l1_vm_state_index; 1217 bool update_header = false; 1218 1219 ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); 1220 if (ret < 0) { 1221 error_setg_errno(errp, -ret, "Could not read qcow2 header"); 1222 goto fail; 1223 } 1224 header.magic = be32_to_cpu(header.magic); 1225 header.version = be32_to_cpu(header.version); 1226 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 1227 header.backing_file_size = be32_to_cpu(header.backing_file_size); 1228 header.size = be64_to_cpu(header.size); 1229 header.cluster_bits = be32_to_cpu(header.cluster_bits); 1230 header.crypt_method = be32_to_cpu(header.crypt_method); 1231 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 1232 header.l1_size = be32_to_cpu(header.l1_size); 1233 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); 1234 header.refcount_table_clusters = 1235 be32_to_cpu(header.refcount_table_clusters); 1236 header.snapshots_offset = be64_to_cpu(header.snapshots_offset); 1237 header.nb_snapshots = be32_to_cpu(header.nb_snapshots); 1238 1239 if (header.magic != QCOW_MAGIC) { 1240 error_setg(errp, "Image is not in qcow2 format"); 1241 ret = -EINVAL; 1242 goto fail; 1243 } 1244 if (header.version < 2 || header.version > 3) { 1245 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); 1246 ret = -ENOTSUP; 1247 goto fail; 1248 } 1249 1250 s->qcow_version = header.version; 1251 1252 /* Initialise cluster size */ 1253 if (header.cluster_bits < MIN_CLUSTER_BITS || 1254 header.cluster_bits > MAX_CLUSTER_BITS) { 1255 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, 1256 header.cluster_bits); 1257 ret = -EINVAL; 1258 goto fail; 1259 } 1260 1261 s->cluster_bits = header.cluster_bits; 1262 s->cluster_size = 1 << s->cluster_bits; 1263 1264 /* Initialise version 3 header fields */ 1265 if (header.version == 2) { 1266 header.incompatible_features = 0; 1267 header.compatible_features = 0; 1268 header.autoclear_features = 0; 1269 header.refcount_order = 4; 1270 header.header_length = 72; 1271 } else { 1272 header.incompatible_features = 1273 be64_to_cpu(header.incompatible_features); 1274 header.compatible_features = be64_to_cpu(header.compatible_features); 1275 header.autoclear_features = be64_to_cpu(header.autoclear_features); 1276 header.refcount_order = be32_to_cpu(header.refcount_order); 1277 header.header_length = be32_to_cpu(header.header_length); 1278 1279 if (header.header_length < 104) { 1280 error_setg(errp, "qcow2 header too short"); 1281 ret = -EINVAL; 1282 goto fail; 1283 } 1284 } 1285 1286 if (header.header_length > s->cluster_size) { 1287 error_setg(errp, "qcow2 header exceeds cluster size"); 1288 ret = -EINVAL; 1289 goto fail; 1290 } 1291 1292 if (header.header_length > sizeof(header)) { 1293 s->unknown_header_fields_size = header.header_length - sizeof(header); 1294 s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); 1295 ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields, 1296 s->unknown_header_fields_size); 1297 if (ret < 0) { 1298 error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " 1299 "fields"); 1300 goto fail; 1301 } 1302 } 1303 1304 if (header.backing_file_offset > s->cluster_size) { 1305 error_setg(errp, "Invalid backing file offset"); 1306 ret = -EINVAL; 1307 goto fail; 1308 } 1309 1310 if (header.backing_file_offset) { 1311 ext_end = header.backing_file_offset; 1312 } else { 1313 ext_end = 1 << header.cluster_bits; 1314 } 1315 1316 /* Handle feature bits */ 1317 s->incompatible_features = header.incompatible_features; 1318 s->compatible_features = header.compatible_features; 1319 s->autoclear_features = header.autoclear_features; 1320 1321 if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { 1322 void *feature_table = NULL; 1323 qcow2_read_extensions(bs, header.header_length, ext_end, 1324 &feature_table, flags, NULL, NULL); 1325 report_unsupported_feature(errp, feature_table, 1326 s->incompatible_features & 1327 ~QCOW2_INCOMPAT_MASK); 1328 ret = -ENOTSUP; 1329 g_free(feature_table); 1330 goto fail; 1331 } 1332 1333 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 1334 /* Corrupt images may not be written to unless they are being repaired 1335 */ 1336 if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { 1337 error_setg(errp, "qcow2: Image is corrupt; cannot be opened " 1338 "read/write"); 1339 ret = -EACCES; 1340 goto fail; 1341 } 1342 } 1343 1344 /* Check support for various header values */ 1345 if (header.refcount_order > 6) { 1346 error_setg(errp, "Reference count entry width too large; may not " 1347 "exceed 64 bits"); 1348 ret = -EINVAL; 1349 goto fail; 1350 } 1351 s->refcount_order = header.refcount_order; 1352 s->refcount_bits = 1 << s->refcount_order; 1353 s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); 1354 s->refcount_max += s->refcount_max - 1; 1355 1356 s->crypt_method_header = header.crypt_method; 1357 if (s->crypt_method_header) { 1358 if (bdrv_uses_whitelist() && 1359 s->crypt_method_header == QCOW_CRYPT_AES) { 1360 error_setg(errp, 1361 "Use of AES-CBC encrypted qcow2 images is no longer " 1362 "supported in system emulators"); 1363 error_append_hint(errp, 1364 "You can use 'qemu-img convert' to convert your " 1365 "image to an alternative supported format, such " 1366 "as unencrypted qcow2, or raw with the LUKS " 1367 "format instead.\n"); 1368 ret = -ENOSYS; 1369 goto fail; 1370 } 1371 1372 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1373 s->crypt_physical_offset = false; 1374 } else { 1375 /* Assuming LUKS and any future crypt methods we 1376 * add will all use physical offsets, due to the 1377 * fact that the alternative is insecure... */ 1378 s->crypt_physical_offset = true; 1379 } 1380 1381 bs->encrypted = true; 1382 } 1383 1384 s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ 1385 s->l2_size = 1 << s->l2_bits; 1386 /* 2^(s->refcount_order - 3) is the refcount width in bytes */ 1387 s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); 1388 s->refcount_block_size = 1 << s->refcount_block_bits; 1389 bs->total_sectors = header.size / BDRV_SECTOR_SIZE; 1390 s->csize_shift = (62 - (s->cluster_bits - 8)); 1391 s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; 1392 s->cluster_offset_mask = (1LL << s->csize_shift) - 1; 1393 1394 s->refcount_table_offset = header.refcount_table_offset; 1395 s->refcount_table_size = 1396 header.refcount_table_clusters << (s->cluster_bits - 3); 1397 1398 if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { 1399 error_setg(errp, "Image does not contain a reference count table"); 1400 ret = -EINVAL; 1401 goto fail; 1402 } 1403 1404 ret = qcow2_validate_table(bs, s->refcount_table_offset, 1405 header.refcount_table_clusters, 1406 s->cluster_size, QCOW_MAX_REFTABLE_SIZE, 1407 "Reference count table", errp); 1408 if (ret < 0) { 1409 goto fail; 1410 } 1411 1412 /* The total size in bytes of the snapshot table is checked in 1413 * qcow2_read_snapshots() because the size of each snapshot is 1414 * variable and we don't know it yet. 1415 * Here we only check the offset and number of snapshots. */ 1416 ret = qcow2_validate_table(bs, header.snapshots_offset, 1417 header.nb_snapshots, 1418 sizeof(QCowSnapshotHeader), 1419 sizeof(QCowSnapshotHeader) * QCOW_MAX_SNAPSHOTS, 1420 "Snapshot table", errp); 1421 if (ret < 0) { 1422 goto fail; 1423 } 1424 1425 /* read the level 1 table */ 1426 ret = qcow2_validate_table(bs, header.l1_table_offset, 1427 header.l1_size, sizeof(uint64_t), 1428 QCOW_MAX_L1_SIZE, "Active L1 table", errp); 1429 if (ret < 0) { 1430 goto fail; 1431 } 1432 s->l1_size = header.l1_size; 1433 s->l1_table_offset = header.l1_table_offset; 1434 1435 l1_vm_state_index = size_to_l1(s, header.size); 1436 if (l1_vm_state_index > INT_MAX) { 1437 error_setg(errp, "Image is too big"); 1438 ret = -EFBIG; 1439 goto fail; 1440 } 1441 s->l1_vm_state_index = l1_vm_state_index; 1442 1443 /* the L1 table must contain at least enough entries to put 1444 header.size bytes */ 1445 if (s->l1_size < s->l1_vm_state_index) { 1446 error_setg(errp, "L1 table is too small"); 1447 ret = -EINVAL; 1448 goto fail; 1449 } 1450 1451 if (s->l1_size > 0) { 1452 s->l1_table = qemu_try_blockalign(bs->file->bs, 1453 ROUND_UP(s->l1_size * sizeof(uint64_t), 512)); 1454 if (s->l1_table == NULL) { 1455 error_setg(errp, "Could not allocate L1 table"); 1456 ret = -ENOMEM; 1457 goto fail; 1458 } 1459 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, 1460 s->l1_size * sizeof(uint64_t)); 1461 if (ret < 0) { 1462 error_setg_errno(errp, -ret, "Could not read L1 table"); 1463 goto fail; 1464 } 1465 for(i = 0;i < s->l1_size; i++) { 1466 s->l1_table[i] = be64_to_cpu(s->l1_table[i]); 1467 } 1468 } 1469 1470 /* Parse driver-specific options */ 1471 ret = qcow2_update_options(bs, options, flags, errp); 1472 if (ret < 0) { 1473 goto fail; 1474 } 1475 1476 s->flags = flags; 1477 1478 ret = qcow2_refcount_init(bs); 1479 if (ret != 0) { 1480 error_setg_errno(errp, -ret, "Could not initialize refcount handling"); 1481 goto fail; 1482 } 1483 1484 QLIST_INIT(&s->cluster_allocs); 1485 QTAILQ_INIT(&s->discards); 1486 1487 /* read qcow2 extensions */ 1488 if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, 1489 flags, &update_header, &local_err)) { 1490 error_propagate(errp, local_err); 1491 ret = -EINVAL; 1492 goto fail; 1493 } 1494 1495 /* Open external data file */ 1496 s->data_file = bdrv_open_child(NULL, options, "data-file", bs, &child_file, 1497 true, &local_err); 1498 if (local_err) { 1499 error_propagate(errp, local_err); 1500 ret = -EINVAL; 1501 goto fail; 1502 } 1503 1504 if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { 1505 if (!s->data_file && s->image_data_file) { 1506 s->data_file = bdrv_open_child(s->image_data_file, options, 1507 "data-file", bs, &child_file, 1508 false, errp); 1509 if (!s->data_file) { 1510 ret = -EINVAL; 1511 goto fail; 1512 } 1513 } 1514 if (!s->data_file) { 1515 error_setg(errp, "'data-file' is required for this image"); 1516 ret = -EINVAL; 1517 goto fail; 1518 } 1519 } else { 1520 if (s->data_file) { 1521 error_setg(errp, "'data-file' can only be set for images with an " 1522 "external data file"); 1523 ret = -EINVAL; 1524 goto fail; 1525 } 1526 1527 s->data_file = bs->file; 1528 1529 if (data_file_is_raw(bs)) { 1530 error_setg(errp, "data-file-raw requires a data file"); 1531 ret = -EINVAL; 1532 goto fail; 1533 } 1534 } 1535 1536 /* qcow2_read_extension may have set up the crypto context 1537 * if the crypt method needs a header region, some methods 1538 * don't need header extensions, so must check here 1539 */ 1540 if (s->crypt_method_header && !s->crypto) { 1541 if (s->crypt_method_header == QCOW_CRYPT_AES) { 1542 unsigned int cflags = 0; 1543 if (flags & BDRV_O_NO_IO) { 1544 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 1545 } 1546 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 1547 NULL, NULL, cflags, 1548 QCOW2_MAX_THREADS, errp); 1549 if (!s->crypto) { 1550 ret = -EINVAL; 1551 goto fail; 1552 } 1553 } else if (!(flags & BDRV_O_NO_IO)) { 1554 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1555 s->crypt_method_header); 1556 ret = -EINVAL; 1557 goto fail; 1558 } 1559 } 1560 1561 /* read the backing file name */ 1562 if (header.backing_file_offset != 0) { 1563 len = header.backing_file_size; 1564 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1565 len >= sizeof(bs->backing_file)) { 1566 error_setg(errp, "Backing file name too long"); 1567 ret = -EINVAL; 1568 goto fail; 1569 } 1570 ret = bdrv_pread(bs->file, header.backing_file_offset, 1571 bs->auto_backing_file, len); 1572 if (ret < 0) { 1573 error_setg_errno(errp, -ret, "Could not read backing file name"); 1574 goto fail; 1575 } 1576 bs->auto_backing_file[len] = '\0'; 1577 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1578 bs->auto_backing_file); 1579 s->image_backing_file = g_strdup(bs->auto_backing_file); 1580 } 1581 1582 /* Internal snapshots */ 1583 s->snapshots_offset = header.snapshots_offset; 1584 s->nb_snapshots = header.nb_snapshots; 1585 1586 ret = qcow2_read_snapshots(bs); 1587 if (ret < 0) { 1588 error_setg_errno(errp, -ret, "Could not read snapshots"); 1589 goto fail; 1590 } 1591 1592 /* Clear unknown autoclear feature bits */ 1593 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1594 update_header = 1595 update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE); 1596 if (update_header) { 1597 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1598 } 1599 1600 /* == Handle persistent dirty bitmaps == 1601 * 1602 * We want load dirty bitmaps in three cases: 1603 * 1604 * 1. Normal open of the disk in active mode, not related to invalidation 1605 * after migration. 1606 * 1607 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1608 * bitmaps are _not_ migrating through migration channel, i.e. 1609 * 'dirty-bitmaps' capability is disabled. 1610 * 1611 * 3. Invalidation of source vm after failed or canceled migration. 1612 * This is a very interesting case. There are two possible types of 1613 * bitmaps: 1614 * 1615 * A. Stored on inactivation and removed. They should be loaded from the 1616 * image. 1617 * 1618 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1619 * the migration channel (with dirty-bitmaps capability). 1620 * 1621 * On the other hand, there are two possible sub-cases: 1622 * 1623 * 3.1 disk was changed by somebody else while were inactive. In this 1624 * case all in-RAM dirty bitmaps (both persistent and not) are 1625 * definitely invalid. And we don't have any method to determine 1626 * this. 1627 * 1628 * Simple and safe thing is to just drop all the bitmaps of type B on 1629 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1630 * 1631 * On the other hand, resuming source vm, if disk was already changed 1632 * is a bad thing anyway: not only bitmaps, the whole vm state is 1633 * out of sync with disk. 1634 * 1635 * This means, that user or management tool, who for some reason 1636 * decided to resume source vm, after disk was already changed by 1637 * target vm, should at least drop all dirty bitmaps by hand. 1638 * 1639 * So, we can ignore this case for now, but TODO: "generation" 1640 * extension for qcow2, to determine, that image was changed after 1641 * last inactivation. And if it is changed, we will drop (or at least 1642 * mark as 'invalid' all the bitmaps of type B, both persistent 1643 * and not). 1644 * 1645 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1646 * to disk ('dirty-bitmaps' capability disabled), or not saved 1647 * ('dirty-bitmaps' capability enabled), but we don't need to care 1648 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1649 * and not stored has flag IN_USE=1 in the image and will be skipped 1650 * on loading. 1651 * 1652 * One remaining possible case when we don't want load bitmaps: 1653 * 1654 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1655 * will be loaded on invalidation, no needs try loading them before) 1656 */ 1657 1658 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1659 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1660 bool header_updated = qcow2_load_dirty_bitmaps(bs, &local_err); 1661 1662 update_header = update_header && !header_updated; 1663 } 1664 if (local_err != NULL) { 1665 error_propagate(errp, local_err); 1666 ret = -EINVAL; 1667 goto fail; 1668 } 1669 1670 if (update_header) { 1671 ret = qcow2_update_header(bs); 1672 if (ret < 0) { 1673 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1674 goto fail; 1675 } 1676 } 1677 1678 bs->supported_zero_flags = header.version >= 3 ? BDRV_REQ_MAY_UNMAP : 0; 1679 1680 /* Repair image if dirty */ 1681 if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only && 1682 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1683 BdrvCheckResult result = {0}; 1684 1685 ret = qcow2_co_check_locked(bs, &result, 1686 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1687 if (ret < 0 || result.check_errors) { 1688 if (ret >= 0) { 1689 ret = -EIO; 1690 } 1691 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1692 goto fail; 1693 } 1694 } 1695 1696 #ifdef DEBUG_ALLOC 1697 { 1698 BdrvCheckResult result = {0}; 1699 qcow2_check_refcounts(bs, &result, 0); 1700 } 1701 #endif 1702 1703 qemu_co_queue_init(&s->thread_task_queue); 1704 1705 return ret; 1706 1707 fail: 1708 g_free(s->image_data_file); 1709 if (has_data_file(bs)) { 1710 bdrv_unref_child(bs, s->data_file); 1711 } 1712 g_free(s->unknown_header_fields); 1713 cleanup_unknown_header_ext(bs); 1714 qcow2_free_snapshots(bs); 1715 qcow2_refcount_close(bs); 1716 qemu_vfree(s->l1_table); 1717 /* else pre-write overlap checks in cache_destroy may crash */ 1718 s->l1_table = NULL; 1719 cache_clean_timer_del(bs); 1720 if (s->l2_table_cache) { 1721 qcow2_cache_destroy(s->l2_table_cache); 1722 } 1723 if (s->refcount_block_cache) { 1724 qcow2_cache_destroy(s->refcount_block_cache); 1725 } 1726 qcrypto_block_free(s->crypto); 1727 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1728 return ret; 1729 } 1730 1731 typedef struct QCow2OpenCo { 1732 BlockDriverState *bs; 1733 QDict *options; 1734 int flags; 1735 Error **errp; 1736 int ret; 1737 } QCow2OpenCo; 1738 1739 static void coroutine_fn qcow2_open_entry(void *opaque) 1740 { 1741 QCow2OpenCo *qoc = opaque; 1742 BDRVQcow2State *s = qoc->bs->opaque; 1743 1744 qemu_co_mutex_lock(&s->lock); 1745 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 1746 qemu_co_mutex_unlock(&s->lock); 1747 } 1748 1749 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1750 Error **errp) 1751 { 1752 BDRVQcow2State *s = bs->opaque; 1753 QCow2OpenCo qoc = { 1754 .bs = bs, 1755 .options = options, 1756 .flags = flags, 1757 .errp = errp, 1758 .ret = -EINPROGRESS 1759 }; 1760 1761 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 1762 false, errp); 1763 if (!bs->file) { 1764 return -EINVAL; 1765 } 1766 1767 /* Initialise locks */ 1768 qemu_co_mutex_init(&s->lock); 1769 1770 if (qemu_in_coroutine()) { 1771 /* From bdrv_co_create. */ 1772 qcow2_open_entry(&qoc); 1773 } else { 1774 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1775 qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry, &qoc)); 1776 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 1777 } 1778 return qoc.ret; 1779 } 1780 1781 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1782 { 1783 BDRVQcow2State *s = bs->opaque; 1784 1785 if (bs->encrypted) { 1786 /* Encryption works on a sector granularity */ 1787 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1788 } 1789 bs->bl.pwrite_zeroes_alignment = s->cluster_size; 1790 bs->bl.pdiscard_alignment = s->cluster_size; 1791 } 1792 1793 static int qcow2_reopen_prepare(BDRVReopenState *state, 1794 BlockReopenQueue *queue, Error **errp) 1795 { 1796 Qcow2ReopenState *r; 1797 int ret; 1798 1799 r = g_new0(Qcow2ReopenState, 1); 1800 state->opaque = r; 1801 1802 ret = qcow2_update_options_prepare(state->bs, r, state->options, 1803 state->flags, errp); 1804 if (ret < 0) { 1805 goto fail; 1806 } 1807 1808 /* We need to write out any unwritten data if we reopen read-only. */ 1809 if ((state->flags & BDRV_O_RDWR) == 0) { 1810 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 1811 if (ret < 0) { 1812 goto fail; 1813 } 1814 1815 ret = bdrv_flush(state->bs); 1816 if (ret < 0) { 1817 goto fail; 1818 } 1819 1820 ret = qcow2_mark_clean(state->bs); 1821 if (ret < 0) { 1822 goto fail; 1823 } 1824 } 1825 1826 return 0; 1827 1828 fail: 1829 qcow2_update_options_abort(state->bs, r); 1830 g_free(r); 1831 return ret; 1832 } 1833 1834 static void qcow2_reopen_commit(BDRVReopenState *state) 1835 { 1836 qcow2_update_options_commit(state->bs, state->opaque); 1837 g_free(state->opaque); 1838 } 1839 1840 static void qcow2_reopen_abort(BDRVReopenState *state) 1841 { 1842 qcow2_update_options_abort(state->bs, state->opaque); 1843 g_free(state->opaque); 1844 } 1845 1846 static void qcow2_join_options(QDict *options, QDict *old_options) 1847 { 1848 bool has_new_overlap_template = 1849 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 1850 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 1851 bool has_new_total_cache_size = 1852 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 1853 bool has_all_cache_options; 1854 1855 /* New overlap template overrides all old overlap options */ 1856 if (has_new_overlap_template) { 1857 qdict_del(old_options, QCOW2_OPT_OVERLAP); 1858 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 1859 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 1860 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 1861 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 1862 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 1863 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 1864 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 1865 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 1866 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 1867 } 1868 1869 /* New total cache size overrides all old options */ 1870 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 1871 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 1872 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 1873 } 1874 1875 qdict_join(options, old_options, false); 1876 1877 /* 1878 * If after merging all cache size options are set, an old total size is 1879 * overwritten. Do keep all options, however, if all three are new. The 1880 * resulting error message is what we want to happen. 1881 */ 1882 has_all_cache_options = 1883 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 1884 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 1885 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 1886 1887 if (has_all_cache_options && !has_new_total_cache_size) { 1888 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 1889 } 1890 } 1891 1892 static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs, 1893 bool want_zero, 1894 int64_t offset, int64_t count, 1895 int64_t *pnum, int64_t *map, 1896 BlockDriverState **file) 1897 { 1898 BDRVQcow2State *s = bs->opaque; 1899 uint64_t cluster_offset; 1900 int index_in_cluster, ret; 1901 unsigned int bytes; 1902 int status = 0; 1903 1904 if (!s->metadata_preallocation_checked) { 1905 ret = qcow2_detect_metadata_preallocation(bs); 1906 s->metadata_preallocation = (ret == 1); 1907 s->metadata_preallocation_checked = true; 1908 } 1909 1910 bytes = MIN(INT_MAX, count); 1911 qemu_co_mutex_lock(&s->lock); 1912 ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset); 1913 qemu_co_mutex_unlock(&s->lock); 1914 if (ret < 0) { 1915 return ret; 1916 } 1917 1918 *pnum = bytes; 1919 1920 if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) && 1921 !s->crypto) { 1922 index_in_cluster = offset & (s->cluster_size - 1); 1923 *map = cluster_offset | index_in_cluster; 1924 *file = s->data_file->bs; 1925 status |= BDRV_BLOCK_OFFSET_VALID; 1926 } 1927 if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) { 1928 status |= BDRV_BLOCK_ZERO; 1929 } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { 1930 status |= BDRV_BLOCK_DATA; 1931 } 1932 if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && 1933 (status & BDRV_BLOCK_OFFSET_VALID)) 1934 { 1935 status |= BDRV_BLOCK_RECURSE; 1936 } 1937 return status; 1938 } 1939 1940 static coroutine_fn int qcow2_handle_l2meta(BlockDriverState *bs, 1941 QCowL2Meta **pl2meta, 1942 bool link_l2) 1943 { 1944 int ret = 0; 1945 QCowL2Meta *l2meta = *pl2meta; 1946 1947 while (l2meta != NULL) { 1948 QCowL2Meta *next; 1949 1950 if (link_l2) { 1951 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 1952 if (ret) { 1953 goto out; 1954 } 1955 } else { 1956 qcow2_alloc_cluster_abort(bs, l2meta); 1957 } 1958 1959 /* Take the request off the list of running requests */ 1960 if (l2meta->nb_clusters != 0) { 1961 QLIST_REMOVE(l2meta, next_in_flight); 1962 } 1963 1964 qemu_co_queue_restart_all(&l2meta->dependent_requests); 1965 1966 next = l2meta->next; 1967 g_free(l2meta); 1968 l2meta = next; 1969 } 1970 out: 1971 *pl2meta = l2meta; 1972 return ret; 1973 } 1974 1975 static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs, 1976 uint64_t offset, uint64_t bytes, 1977 QEMUIOVector *qiov, 1978 size_t qiov_offset, int flags) 1979 { 1980 BDRVQcow2State *s = bs->opaque; 1981 int offset_in_cluster; 1982 int ret; 1983 unsigned int cur_bytes; /* number of bytes in current iteration */ 1984 uint64_t cluster_offset = 0; 1985 uint8_t *cluster_data = NULL; 1986 1987 while (bytes != 0) { 1988 1989 /* prepare next request */ 1990 cur_bytes = MIN(bytes, INT_MAX); 1991 if (s->crypto) { 1992 cur_bytes = MIN(cur_bytes, 1993 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 1994 } 1995 1996 qemu_co_mutex_lock(&s->lock); 1997 ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset); 1998 qemu_co_mutex_unlock(&s->lock); 1999 if (ret < 0) { 2000 goto fail; 2001 } 2002 2003 offset_in_cluster = offset_into_cluster(s, offset); 2004 2005 switch (ret) { 2006 case QCOW2_CLUSTER_UNALLOCATED: 2007 2008 if (bs->backing) { 2009 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2010 ret = bdrv_co_preadv_part(bs->backing, offset, cur_bytes, 2011 qiov, qiov_offset, 0); 2012 if (ret < 0) { 2013 goto fail; 2014 } 2015 } else { 2016 /* Note: in this case, no need to wait */ 2017 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2018 } 2019 break; 2020 2021 case QCOW2_CLUSTER_ZERO_PLAIN: 2022 case QCOW2_CLUSTER_ZERO_ALLOC: 2023 qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); 2024 break; 2025 2026 case QCOW2_CLUSTER_COMPRESSED: 2027 ret = qcow2_co_preadv_compressed(bs, cluster_offset, 2028 offset, cur_bytes, 2029 qiov, qiov_offset); 2030 if (ret < 0) { 2031 goto fail; 2032 } 2033 2034 break; 2035 2036 case QCOW2_CLUSTER_NORMAL: 2037 if ((cluster_offset & 511) != 0) { 2038 ret = -EIO; 2039 goto fail; 2040 } 2041 2042 if (bs->encrypted) { 2043 assert(s->crypto); 2044 2045 /* 2046 * For encrypted images, read everything into a temporary 2047 * contiguous buffer on which the AES functions can work. 2048 */ 2049 if (!cluster_data) { 2050 cluster_data = 2051 qemu_try_blockalign(s->data_file->bs, 2052 QCOW_MAX_CRYPT_CLUSTERS 2053 * s->cluster_size); 2054 if (cluster_data == NULL) { 2055 ret = -ENOMEM; 2056 goto fail; 2057 } 2058 } 2059 2060 assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2061 2062 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 2063 ret = bdrv_co_pread(s->data_file, 2064 cluster_offset + offset_in_cluster, 2065 cur_bytes, cluster_data, 0); 2066 if (ret < 0) { 2067 goto fail; 2068 } 2069 2070 assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)); 2071 assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE)); 2072 if (qcow2_co_decrypt(bs, cluster_offset + offset_in_cluster, 2073 offset, 2074 cluster_data, cur_bytes) < 0) { 2075 ret = -EIO; 2076 goto fail; 2077 } 2078 qemu_iovec_from_buf(qiov, qiov_offset, cluster_data, cur_bytes); 2079 } else { 2080 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 2081 ret = bdrv_co_preadv_part(s->data_file, 2082 cluster_offset + offset_in_cluster, 2083 cur_bytes, qiov, qiov_offset, 0); 2084 if (ret < 0) { 2085 goto fail; 2086 } 2087 } 2088 break; 2089 2090 default: 2091 g_assert_not_reached(); 2092 ret = -EIO; 2093 goto fail; 2094 } 2095 2096 bytes -= cur_bytes; 2097 offset += cur_bytes; 2098 qiov_offset += cur_bytes; 2099 } 2100 ret = 0; 2101 2102 fail: 2103 qemu_vfree(cluster_data); 2104 2105 return ret; 2106 } 2107 2108 /* Check if it's possible to merge a write request with the writing of 2109 * the data from the COW regions */ 2110 static bool merge_cow(uint64_t offset, unsigned bytes, 2111 QEMUIOVector *qiov, size_t qiov_offset, 2112 QCowL2Meta *l2meta) 2113 { 2114 QCowL2Meta *m; 2115 2116 for (m = l2meta; m != NULL; m = m->next) { 2117 /* If both COW regions are empty then there's nothing to merge */ 2118 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2119 continue; 2120 } 2121 2122 /* If COW regions are handled already, skip this too */ 2123 if (m->skip_cow) { 2124 continue; 2125 } 2126 2127 /* The data (middle) region must be immediately after the 2128 * start region */ 2129 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2130 continue; 2131 } 2132 2133 /* The end region must be immediately after the data (middle) 2134 * region */ 2135 if (m->offset + m->cow_end.offset != offset + bytes) { 2136 continue; 2137 } 2138 2139 /* Make sure that adding both COW regions to the QEMUIOVector 2140 * does not exceed IOV_MAX */ 2141 if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { 2142 continue; 2143 } 2144 2145 m->data_qiov = qiov; 2146 m->data_qiov_offset = qiov_offset; 2147 return true; 2148 } 2149 2150 return false; 2151 } 2152 2153 static bool is_unallocated(BlockDriverState *bs, int64_t offset, int64_t bytes) 2154 { 2155 int64_t nr; 2156 return !bytes || 2157 (!bdrv_is_allocated_above(bs, NULL, false, offset, bytes, &nr) && 2158 nr == bytes); 2159 } 2160 2161 static bool is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) 2162 { 2163 /* 2164 * This check is designed for optimization shortcut so it must be 2165 * efficient. 2166 * Instead of is_zero(), use is_unallocated() as it is faster (but not 2167 * as accurate and can result in false negatives). 2168 */ 2169 return is_unallocated(bs, m->offset + m->cow_start.offset, 2170 m->cow_start.nb_bytes) && 2171 is_unallocated(bs, m->offset + m->cow_end.offset, 2172 m->cow_end.nb_bytes); 2173 } 2174 2175 static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) 2176 { 2177 BDRVQcow2State *s = bs->opaque; 2178 QCowL2Meta *m; 2179 2180 if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { 2181 return 0; 2182 } 2183 2184 if (bs->encrypted) { 2185 return 0; 2186 } 2187 2188 for (m = l2meta; m != NULL; m = m->next) { 2189 int ret; 2190 2191 if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { 2192 continue; 2193 } 2194 2195 if (!is_zero_cow(bs, m)) { 2196 continue; 2197 } 2198 2199 /* 2200 * instead of writing zero COW buffers, 2201 * efficiently zero out the whole clusters 2202 */ 2203 2204 ret = qcow2_pre_write_overlap_check(bs, 0, m->alloc_offset, 2205 m->nb_clusters * s->cluster_size, 2206 true); 2207 if (ret < 0) { 2208 return ret; 2209 } 2210 2211 BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); 2212 ret = bdrv_co_pwrite_zeroes(s->data_file, m->alloc_offset, 2213 m->nb_clusters * s->cluster_size, 2214 BDRV_REQ_NO_FALLBACK); 2215 if (ret < 0) { 2216 if (ret != -ENOTSUP && ret != -EAGAIN) { 2217 return ret; 2218 } 2219 continue; 2220 } 2221 2222 trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); 2223 m->skip_cow = true; 2224 } 2225 return 0; 2226 } 2227 2228 static coroutine_fn int qcow2_co_pwritev_part( 2229 BlockDriverState *bs, uint64_t offset, uint64_t bytes, 2230 QEMUIOVector *qiov, size_t qiov_offset, int flags) 2231 { 2232 BDRVQcow2State *s = bs->opaque; 2233 int offset_in_cluster; 2234 int ret; 2235 unsigned int cur_bytes; /* number of sectors in current iteration */ 2236 uint64_t cluster_offset; 2237 QEMUIOVector encrypted_qiov; 2238 uint64_t bytes_done = 0; 2239 uint8_t *cluster_data = NULL; 2240 QCowL2Meta *l2meta = NULL; 2241 2242 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2243 2244 qemu_co_mutex_lock(&s->lock); 2245 2246 while (bytes != 0) { 2247 2248 l2meta = NULL; 2249 2250 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2251 offset_in_cluster = offset_into_cluster(s, offset); 2252 cur_bytes = MIN(bytes, INT_MAX); 2253 if (bs->encrypted) { 2254 cur_bytes = MIN(cur_bytes, 2255 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2256 - offset_in_cluster); 2257 } 2258 2259 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 2260 &cluster_offset, &l2meta); 2261 if (ret < 0) { 2262 goto out_locked; 2263 } 2264 2265 assert((cluster_offset & 511) == 0); 2266 2267 ret = qcow2_pre_write_overlap_check(bs, 0, 2268 cluster_offset + offset_in_cluster, 2269 cur_bytes, true); 2270 if (ret < 0) { 2271 goto out_locked; 2272 } 2273 2274 qemu_co_mutex_unlock(&s->lock); 2275 2276 if (bs->encrypted) { 2277 assert(s->crypto); 2278 if (!cluster_data) { 2279 cluster_data = qemu_try_blockalign(bs->file->bs, 2280 QCOW_MAX_CRYPT_CLUSTERS 2281 * s->cluster_size); 2282 if (cluster_data == NULL) { 2283 ret = -ENOMEM; 2284 goto out_unlocked; 2285 } 2286 } 2287 2288 assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2289 qemu_iovec_to_buf(qiov, qiov_offset + bytes_done, 2290 cluster_data, cur_bytes); 2291 2292 if (qcow2_co_encrypt(bs, cluster_offset + offset_in_cluster, offset, 2293 cluster_data, cur_bytes) < 0) { 2294 ret = -EIO; 2295 goto out_unlocked; 2296 } 2297 2298 qemu_iovec_init_buf(&encrypted_qiov, cluster_data, cur_bytes); 2299 } 2300 2301 /* Try to efficiently initialize the physical space with zeroes */ 2302 ret = handle_alloc_space(bs, l2meta); 2303 if (ret < 0) { 2304 goto out_unlocked; 2305 } 2306 2307 /* If we need to do COW, check if it's possible to merge the 2308 * writing of the guest data together with that of the COW regions. 2309 * If it's not possible (or not necessary) then write the 2310 * guest data now. */ 2311 if (!merge_cow(offset, cur_bytes, 2312 bs->encrypted ? &encrypted_qiov : qiov, 2313 bs->encrypted ? 0 : qiov_offset + bytes_done, l2meta)) 2314 { 2315 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); 2316 trace_qcow2_writev_data(qemu_coroutine_self(), 2317 cluster_offset + offset_in_cluster); 2318 ret = bdrv_co_pwritev_part( 2319 s->data_file, cluster_offset + offset_in_cluster, cur_bytes, 2320 bs->encrypted ? &encrypted_qiov : qiov, 2321 bs->encrypted ? 0 : qiov_offset + bytes_done, 0); 2322 if (ret < 0) { 2323 goto out_unlocked; 2324 } 2325 } 2326 2327 qemu_co_mutex_lock(&s->lock); 2328 2329 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2330 if (ret) { 2331 goto out_locked; 2332 } 2333 2334 bytes -= cur_bytes; 2335 offset += cur_bytes; 2336 bytes_done += cur_bytes; 2337 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2338 } 2339 ret = 0; 2340 goto out_locked; 2341 2342 out_unlocked: 2343 qemu_co_mutex_lock(&s->lock); 2344 2345 out_locked: 2346 qcow2_handle_l2meta(bs, &l2meta, false); 2347 2348 qemu_co_mutex_unlock(&s->lock); 2349 2350 qemu_vfree(cluster_data); 2351 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2352 2353 return ret; 2354 } 2355 2356 static int qcow2_inactivate(BlockDriverState *bs) 2357 { 2358 BDRVQcow2State *s = bs->opaque; 2359 int ret, result = 0; 2360 Error *local_err = NULL; 2361 2362 qcow2_store_persistent_dirty_bitmaps(bs, &local_err); 2363 if (local_err != NULL) { 2364 result = -EINVAL; 2365 error_reportf_err(local_err, "Lost persistent bitmaps during " 2366 "inactivation of node '%s': ", 2367 bdrv_get_device_or_node_name(bs)); 2368 } 2369 2370 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2371 if (ret) { 2372 result = ret; 2373 error_report("Failed to flush the L2 table cache: %s", 2374 strerror(-ret)); 2375 } 2376 2377 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2378 if (ret) { 2379 result = ret; 2380 error_report("Failed to flush the refcount block cache: %s", 2381 strerror(-ret)); 2382 } 2383 2384 if (result == 0) { 2385 qcow2_mark_clean(bs); 2386 } 2387 2388 return result; 2389 } 2390 2391 static void qcow2_close(BlockDriverState *bs) 2392 { 2393 BDRVQcow2State *s = bs->opaque; 2394 qemu_vfree(s->l1_table); 2395 /* else pre-write overlap checks in cache_destroy may crash */ 2396 s->l1_table = NULL; 2397 2398 if (!(s->flags & BDRV_O_INACTIVE)) { 2399 qcow2_inactivate(bs); 2400 } 2401 2402 cache_clean_timer_del(bs); 2403 qcow2_cache_destroy(s->l2_table_cache); 2404 qcow2_cache_destroy(s->refcount_block_cache); 2405 2406 qcrypto_block_free(s->crypto); 2407 s->crypto = NULL; 2408 2409 g_free(s->unknown_header_fields); 2410 cleanup_unknown_header_ext(bs); 2411 2412 g_free(s->image_data_file); 2413 g_free(s->image_backing_file); 2414 g_free(s->image_backing_format); 2415 2416 if (has_data_file(bs)) { 2417 bdrv_unref_child(bs, s->data_file); 2418 } 2419 2420 qcow2_refcount_close(bs); 2421 qcow2_free_snapshots(bs); 2422 } 2423 2424 static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs, 2425 Error **errp) 2426 { 2427 BDRVQcow2State *s = bs->opaque; 2428 int flags = s->flags; 2429 QCryptoBlock *crypto = NULL; 2430 QDict *options; 2431 Error *local_err = NULL; 2432 int ret; 2433 2434 /* 2435 * Backing files are read-only which makes all of their metadata immutable, 2436 * that means we don't have to worry about reopening them here. 2437 */ 2438 2439 crypto = s->crypto; 2440 s->crypto = NULL; 2441 2442 qcow2_close(bs); 2443 2444 memset(s, 0, sizeof(BDRVQcow2State)); 2445 options = qdict_clone_shallow(bs->options); 2446 2447 flags &= ~BDRV_O_INACTIVE; 2448 qemu_co_mutex_lock(&s->lock); 2449 ret = qcow2_do_open(bs, options, flags, &local_err); 2450 qemu_co_mutex_unlock(&s->lock); 2451 qobject_unref(options); 2452 if (local_err) { 2453 error_propagate_prepend(errp, local_err, 2454 "Could not reopen qcow2 layer: "); 2455 bs->drv = NULL; 2456 return; 2457 } else if (ret < 0) { 2458 error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); 2459 bs->drv = NULL; 2460 return; 2461 } 2462 2463 s->crypto = crypto; 2464 } 2465 2466 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2467 size_t len, size_t buflen) 2468 { 2469 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2470 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2471 2472 if (buflen < ext_len) { 2473 return -ENOSPC; 2474 } 2475 2476 *ext_backing_fmt = (QCowExtension) { 2477 .magic = cpu_to_be32(magic), 2478 .len = cpu_to_be32(len), 2479 }; 2480 2481 if (len) { 2482 memcpy(buf + sizeof(QCowExtension), s, len); 2483 } 2484 2485 return ext_len; 2486 } 2487 2488 /* 2489 * Updates the qcow2 header, including the variable length parts of it, i.e. 2490 * the backing file name and all extensions. qcow2 was not designed to allow 2491 * such changes, so if we run out of space (we can only use the first cluster) 2492 * this function may fail. 2493 * 2494 * Returns 0 on success, -errno in error cases. 2495 */ 2496 int qcow2_update_header(BlockDriverState *bs) 2497 { 2498 BDRVQcow2State *s = bs->opaque; 2499 QCowHeader *header; 2500 char *buf; 2501 size_t buflen = s->cluster_size; 2502 int ret; 2503 uint64_t total_size; 2504 uint32_t refcount_table_clusters; 2505 size_t header_length; 2506 Qcow2UnknownHeaderExtension *uext; 2507 2508 buf = qemu_blockalign(bs, buflen); 2509 2510 /* Header structure */ 2511 header = (QCowHeader*) buf; 2512 2513 if (buflen < sizeof(*header)) { 2514 ret = -ENOSPC; 2515 goto fail; 2516 } 2517 2518 header_length = sizeof(*header) + s->unknown_header_fields_size; 2519 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2520 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2521 2522 *header = (QCowHeader) { 2523 /* Version 2 fields */ 2524 .magic = cpu_to_be32(QCOW_MAGIC), 2525 .version = cpu_to_be32(s->qcow_version), 2526 .backing_file_offset = 0, 2527 .backing_file_size = 0, 2528 .cluster_bits = cpu_to_be32(s->cluster_bits), 2529 .size = cpu_to_be64(total_size), 2530 .crypt_method = cpu_to_be32(s->crypt_method_header), 2531 .l1_size = cpu_to_be32(s->l1_size), 2532 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2533 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2534 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2535 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2536 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2537 2538 /* Version 3 fields */ 2539 .incompatible_features = cpu_to_be64(s->incompatible_features), 2540 .compatible_features = cpu_to_be64(s->compatible_features), 2541 .autoclear_features = cpu_to_be64(s->autoclear_features), 2542 .refcount_order = cpu_to_be32(s->refcount_order), 2543 .header_length = cpu_to_be32(header_length), 2544 }; 2545 2546 /* For older versions, write a shorter header */ 2547 switch (s->qcow_version) { 2548 case 2: 2549 ret = offsetof(QCowHeader, incompatible_features); 2550 break; 2551 case 3: 2552 ret = sizeof(*header); 2553 break; 2554 default: 2555 ret = -EINVAL; 2556 goto fail; 2557 } 2558 2559 buf += ret; 2560 buflen -= ret; 2561 memset(buf, 0, buflen); 2562 2563 /* Preserve any unknown field in the header */ 2564 if (s->unknown_header_fields_size) { 2565 if (buflen < s->unknown_header_fields_size) { 2566 ret = -ENOSPC; 2567 goto fail; 2568 } 2569 2570 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 2571 buf += s->unknown_header_fields_size; 2572 buflen -= s->unknown_header_fields_size; 2573 } 2574 2575 /* Backing file format header extension */ 2576 if (s->image_backing_format) { 2577 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 2578 s->image_backing_format, 2579 strlen(s->image_backing_format), 2580 buflen); 2581 if (ret < 0) { 2582 goto fail; 2583 } 2584 2585 buf += ret; 2586 buflen -= ret; 2587 } 2588 2589 /* External data file header extension */ 2590 if (has_data_file(bs) && s->image_data_file) { 2591 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 2592 s->image_data_file, strlen(s->image_data_file), 2593 buflen); 2594 if (ret < 0) { 2595 goto fail; 2596 } 2597 2598 buf += ret; 2599 buflen -= ret; 2600 } 2601 2602 /* Full disk encryption header pointer extension */ 2603 if (s->crypto_header.offset != 0) { 2604 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 2605 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 2606 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 2607 &s->crypto_header, sizeof(s->crypto_header), 2608 buflen); 2609 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 2610 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 2611 if (ret < 0) { 2612 goto fail; 2613 } 2614 buf += ret; 2615 buflen -= ret; 2616 } 2617 2618 /* Feature table */ 2619 if (s->qcow_version >= 3) { 2620 Qcow2Feature features[] = { 2621 { 2622 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2623 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 2624 .name = "dirty bit", 2625 }, 2626 { 2627 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2628 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 2629 .name = "corrupt bit", 2630 }, 2631 { 2632 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2633 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 2634 .name = "external data file", 2635 }, 2636 { 2637 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 2638 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 2639 .name = "lazy refcounts", 2640 }, 2641 }; 2642 2643 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 2644 features, sizeof(features), buflen); 2645 if (ret < 0) { 2646 goto fail; 2647 } 2648 buf += ret; 2649 buflen -= ret; 2650 } 2651 2652 /* Bitmap extension */ 2653 if (s->nb_bitmaps > 0) { 2654 Qcow2BitmapHeaderExt bitmaps_header = { 2655 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 2656 .bitmap_directory_size = 2657 cpu_to_be64(s->bitmap_directory_size), 2658 .bitmap_directory_offset = 2659 cpu_to_be64(s->bitmap_directory_offset) 2660 }; 2661 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 2662 &bitmaps_header, sizeof(bitmaps_header), 2663 buflen); 2664 if (ret < 0) { 2665 goto fail; 2666 } 2667 buf += ret; 2668 buflen -= ret; 2669 } 2670 2671 /* Keep unknown header extensions */ 2672 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 2673 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 2674 if (ret < 0) { 2675 goto fail; 2676 } 2677 2678 buf += ret; 2679 buflen -= ret; 2680 } 2681 2682 /* End of header extensions */ 2683 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 2684 if (ret < 0) { 2685 goto fail; 2686 } 2687 2688 buf += ret; 2689 buflen -= ret; 2690 2691 /* Backing file name */ 2692 if (s->image_backing_file) { 2693 size_t backing_file_len = strlen(s->image_backing_file); 2694 2695 if (buflen < backing_file_len) { 2696 ret = -ENOSPC; 2697 goto fail; 2698 } 2699 2700 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 2701 strncpy(buf, s->image_backing_file, buflen); 2702 2703 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 2704 header->backing_file_size = cpu_to_be32(backing_file_len); 2705 } 2706 2707 /* Write the new header */ 2708 ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size); 2709 if (ret < 0) { 2710 goto fail; 2711 } 2712 2713 ret = 0; 2714 fail: 2715 qemu_vfree(header); 2716 return ret; 2717 } 2718 2719 static int qcow2_change_backing_file(BlockDriverState *bs, 2720 const char *backing_file, const char *backing_fmt) 2721 { 2722 BDRVQcow2State *s = bs->opaque; 2723 2724 /* Adding a backing file means that the external data file alone won't be 2725 * enough to make sense of the content */ 2726 if (backing_file && data_file_is_raw(bs)) { 2727 return -EINVAL; 2728 } 2729 2730 if (backing_file && strlen(backing_file) > 1023) { 2731 return -EINVAL; 2732 } 2733 2734 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 2735 backing_file ?: ""); 2736 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 2737 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 2738 2739 g_free(s->image_backing_file); 2740 g_free(s->image_backing_format); 2741 2742 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 2743 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 2744 2745 return qcow2_update_header(bs); 2746 } 2747 2748 static int qcow2_crypt_method_from_format(const char *encryptfmt) 2749 { 2750 if (g_str_equal(encryptfmt, "luks")) { 2751 return QCOW_CRYPT_LUKS; 2752 } else if (g_str_equal(encryptfmt, "aes")) { 2753 return QCOW_CRYPT_AES; 2754 } else { 2755 return -EINVAL; 2756 } 2757 } 2758 2759 static int qcow2_set_up_encryption(BlockDriverState *bs, 2760 QCryptoBlockCreateOptions *cryptoopts, 2761 Error **errp) 2762 { 2763 BDRVQcow2State *s = bs->opaque; 2764 QCryptoBlock *crypto = NULL; 2765 int fmt, ret; 2766 2767 switch (cryptoopts->format) { 2768 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 2769 fmt = QCOW_CRYPT_LUKS; 2770 break; 2771 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 2772 fmt = QCOW_CRYPT_AES; 2773 break; 2774 default: 2775 error_setg(errp, "Crypto format not supported in qcow2"); 2776 return -EINVAL; 2777 } 2778 2779 s->crypt_method_header = fmt; 2780 2781 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 2782 qcow2_crypto_hdr_init_func, 2783 qcow2_crypto_hdr_write_func, 2784 bs, errp); 2785 if (!crypto) { 2786 return -EINVAL; 2787 } 2788 2789 ret = qcow2_update_header(bs); 2790 if (ret < 0) { 2791 error_setg_errno(errp, -ret, "Could not write encryption header"); 2792 goto out; 2793 } 2794 2795 ret = 0; 2796 out: 2797 qcrypto_block_free(crypto); 2798 return ret; 2799 } 2800 2801 /** 2802 * Preallocates metadata structures for data clusters between @offset (in the 2803 * guest disk) and @new_length (which is thus generally the new guest disk 2804 * size). 2805 * 2806 * Returns: 0 on success, -errno on failure. 2807 */ 2808 static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset, 2809 uint64_t new_length, PreallocMode mode, 2810 Error **errp) 2811 { 2812 BDRVQcow2State *s = bs->opaque; 2813 uint64_t bytes; 2814 uint64_t host_offset = 0; 2815 int64_t file_length; 2816 unsigned int cur_bytes; 2817 int ret; 2818 QCowL2Meta *meta; 2819 2820 assert(offset <= new_length); 2821 bytes = new_length - offset; 2822 2823 while (bytes) { 2824 cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); 2825 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 2826 &host_offset, &meta); 2827 if (ret < 0) { 2828 error_setg_errno(errp, -ret, "Allocating clusters failed"); 2829 return ret; 2830 } 2831 2832 while (meta) { 2833 QCowL2Meta *next = meta->next; 2834 2835 ret = qcow2_alloc_cluster_link_l2(bs, meta); 2836 if (ret < 0) { 2837 error_setg_errno(errp, -ret, "Mapping clusters failed"); 2838 qcow2_free_any_clusters(bs, meta->alloc_offset, 2839 meta->nb_clusters, QCOW2_DISCARD_NEVER); 2840 return ret; 2841 } 2842 2843 /* There are no dependent requests, but we need to remove our 2844 * request from the list of in-flight requests */ 2845 QLIST_REMOVE(meta, next_in_flight); 2846 2847 g_free(meta); 2848 meta = next; 2849 } 2850 2851 /* TODO Preallocate data if requested */ 2852 2853 bytes -= cur_bytes; 2854 offset += cur_bytes; 2855 } 2856 2857 /* 2858 * It is expected that the image file is large enough to actually contain 2859 * all of the allocated clusters (otherwise we get failing reads after 2860 * EOF). Extend the image to the last allocated sector. 2861 */ 2862 file_length = bdrv_getlength(s->data_file->bs); 2863 if (file_length < 0) { 2864 error_setg_errno(errp, -file_length, "Could not get file size"); 2865 return file_length; 2866 } 2867 2868 if (host_offset + cur_bytes > file_length) { 2869 if (mode == PREALLOC_MODE_METADATA) { 2870 mode = PREALLOC_MODE_OFF; 2871 } 2872 ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, mode, 2873 errp); 2874 if (ret < 0) { 2875 return ret; 2876 } 2877 } 2878 2879 return 0; 2880 } 2881 2882 /* qcow2_refcount_metadata_size: 2883 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 2884 * @cluster_size: size of a cluster, in bytes 2885 * @refcount_order: refcount bits power-of-2 exponent 2886 * @generous_increase: allow for the refcount table to be 1.5x as large as it 2887 * needs to be 2888 * 2889 * Returns: Number of bytes required for refcount blocks and table metadata. 2890 */ 2891 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 2892 int refcount_order, bool generous_increase, 2893 uint64_t *refblock_count) 2894 { 2895 /* 2896 * Every host cluster is reference-counted, including metadata (even 2897 * refcount metadata is recursively included). 2898 * 2899 * An accurate formula for the size of refcount metadata size is difficult 2900 * to derive. An easier method of calculation is finding the fixed point 2901 * where no further refcount blocks or table clusters are required to 2902 * reference count every cluster. 2903 */ 2904 int64_t blocks_per_table_cluster = cluster_size / sizeof(uint64_t); 2905 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 2906 int64_t table = 0; /* number of refcount table clusters */ 2907 int64_t blocks = 0; /* number of refcount block clusters */ 2908 int64_t last; 2909 int64_t n = 0; 2910 2911 do { 2912 last = n; 2913 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 2914 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 2915 n = clusters + blocks + table; 2916 2917 if (n == last && generous_increase) { 2918 clusters += DIV_ROUND_UP(table, 2); 2919 n = 0; /* force another loop */ 2920 generous_increase = false; 2921 } 2922 } while (n != last); 2923 2924 if (refblock_count) { 2925 *refblock_count = blocks; 2926 } 2927 2928 return (blocks + table) * cluster_size; 2929 } 2930 2931 /** 2932 * qcow2_calc_prealloc_size: 2933 * @total_size: virtual disk size in bytes 2934 * @cluster_size: cluster size in bytes 2935 * @refcount_order: refcount bits power-of-2 exponent 2936 * 2937 * Returns: Total number of bytes required for the fully allocated image 2938 * (including metadata). 2939 */ 2940 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 2941 size_t cluster_size, 2942 int refcount_order) 2943 { 2944 int64_t meta_size = 0; 2945 uint64_t nl1e, nl2e; 2946 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 2947 2948 /* header: 1 cluster */ 2949 meta_size += cluster_size; 2950 2951 /* total size of L2 tables */ 2952 nl2e = aligned_total_size / cluster_size; 2953 nl2e = ROUND_UP(nl2e, cluster_size / sizeof(uint64_t)); 2954 meta_size += nl2e * sizeof(uint64_t); 2955 2956 /* total size of L1 tables */ 2957 nl1e = nl2e * sizeof(uint64_t) / cluster_size; 2958 nl1e = ROUND_UP(nl1e, cluster_size / sizeof(uint64_t)); 2959 meta_size += nl1e * sizeof(uint64_t); 2960 2961 /* total size of refcount table and blocks */ 2962 meta_size += qcow2_refcount_metadata_size( 2963 (meta_size + aligned_total_size) / cluster_size, 2964 cluster_size, refcount_order, false, NULL); 2965 2966 return meta_size + aligned_total_size; 2967 } 2968 2969 static bool validate_cluster_size(size_t cluster_size, Error **errp) 2970 { 2971 int cluster_bits = ctz32(cluster_size); 2972 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 2973 (1 << cluster_bits) != cluster_size) 2974 { 2975 error_setg(errp, "Cluster size must be a power of two between %d and " 2976 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 2977 return false; 2978 } 2979 return true; 2980 } 2981 2982 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, Error **errp) 2983 { 2984 size_t cluster_size; 2985 2986 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 2987 DEFAULT_CLUSTER_SIZE); 2988 if (!validate_cluster_size(cluster_size, errp)) { 2989 return 0; 2990 } 2991 return cluster_size; 2992 } 2993 2994 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 2995 { 2996 char *buf; 2997 int ret; 2998 2999 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 3000 if (!buf) { 3001 ret = 3; /* default */ 3002 } else if (!strcmp(buf, "0.10")) { 3003 ret = 2; 3004 } else if (!strcmp(buf, "1.1")) { 3005 ret = 3; 3006 } else { 3007 error_setg(errp, "Invalid compatibility level: '%s'", buf); 3008 ret = -EINVAL; 3009 } 3010 g_free(buf); 3011 return ret; 3012 } 3013 3014 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 3015 Error **errp) 3016 { 3017 uint64_t refcount_bits; 3018 3019 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 3020 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 3021 error_setg(errp, "Refcount width must be a power of two and may not " 3022 "exceed 64 bits"); 3023 return 0; 3024 } 3025 3026 if (version < 3 && refcount_bits != 16) { 3027 error_setg(errp, "Different refcount widths than 16 bits require " 3028 "compatibility level 1.1 or above (use compat=1.1 or " 3029 "greater)"); 3030 return 0; 3031 } 3032 3033 return refcount_bits; 3034 } 3035 3036 static int coroutine_fn 3037 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 3038 { 3039 BlockdevCreateOptionsQcow2 *qcow2_opts; 3040 QDict *options; 3041 3042 /* 3043 * Open the image file and write a minimal qcow2 header. 3044 * 3045 * We keep things simple and start with a zero-sized image. We also 3046 * do without refcount blocks or a L1 table for now. We'll fix the 3047 * inconsistency later. 3048 * 3049 * We do need a refcount table because growing the refcount table means 3050 * allocating two new refcount blocks - the seconds of which would be at 3051 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 3052 * size for any qcow2 image. 3053 */ 3054 BlockBackend *blk = NULL; 3055 BlockDriverState *bs = NULL; 3056 BlockDriverState *data_bs = NULL; 3057 QCowHeader *header; 3058 size_t cluster_size; 3059 int version; 3060 int refcount_order; 3061 uint64_t* refcount_table; 3062 Error *local_err = NULL; 3063 int ret; 3064 3065 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 3066 qcow2_opts = &create_options->u.qcow2; 3067 3068 bs = bdrv_open_blockdev_ref(qcow2_opts->file, errp); 3069 if (bs == NULL) { 3070 return -EIO; 3071 } 3072 3073 /* Validate options and set default values */ 3074 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 3075 error_setg(errp, "Image size must be a multiple of 512 bytes"); 3076 ret = -EINVAL; 3077 goto out; 3078 } 3079 3080 if (qcow2_opts->has_version) { 3081 switch (qcow2_opts->version) { 3082 case BLOCKDEV_QCOW2_VERSION_V2: 3083 version = 2; 3084 break; 3085 case BLOCKDEV_QCOW2_VERSION_V3: 3086 version = 3; 3087 break; 3088 default: 3089 g_assert_not_reached(); 3090 } 3091 } else { 3092 version = 3; 3093 } 3094 3095 if (qcow2_opts->has_cluster_size) { 3096 cluster_size = qcow2_opts->cluster_size; 3097 } else { 3098 cluster_size = DEFAULT_CLUSTER_SIZE; 3099 } 3100 3101 if (!validate_cluster_size(cluster_size, errp)) { 3102 ret = -EINVAL; 3103 goto out; 3104 } 3105 3106 if (!qcow2_opts->has_preallocation) { 3107 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3108 } 3109 if (qcow2_opts->has_backing_file && 3110 qcow2_opts->preallocation != PREALLOC_MODE_OFF) 3111 { 3112 error_setg(errp, "Backing file and preallocation cannot be used at " 3113 "the same time"); 3114 ret = -EINVAL; 3115 goto out; 3116 } 3117 if (qcow2_opts->has_backing_fmt && !qcow2_opts->has_backing_file) { 3118 error_setg(errp, "Backing format cannot be used without backing file"); 3119 ret = -EINVAL; 3120 goto out; 3121 } 3122 3123 if (!qcow2_opts->has_lazy_refcounts) { 3124 qcow2_opts->lazy_refcounts = false; 3125 } 3126 if (version < 3 && qcow2_opts->lazy_refcounts) { 3127 error_setg(errp, "Lazy refcounts only supported with compatibility " 3128 "level 1.1 and above (use version=v3 or greater)"); 3129 ret = -EINVAL; 3130 goto out; 3131 } 3132 3133 if (!qcow2_opts->has_refcount_bits) { 3134 qcow2_opts->refcount_bits = 16; 3135 } 3136 if (qcow2_opts->refcount_bits > 64 || 3137 !is_power_of_2(qcow2_opts->refcount_bits)) 3138 { 3139 error_setg(errp, "Refcount width must be a power of two and may not " 3140 "exceed 64 bits"); 3141 ret = -EINVAL; 3142 goto out; 3143 } 3144 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3145 error_setg(errp, "Different refcount widths than 16 bits require " 3146 "compatibility level 1.1 or above (use version=v3 or " 3147 "greater)"); 3148 ret = -EINVAL; 3149 goto out; 3150 } 3151 refcount_order = ctz32(qcow2_opts->refcount_bits); 3152 3153 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3154 error_setg(errp, "data-file-raw requires data-file"); 3155 ret = -EINVAL; 3156 goto out; 3157 } 3158 if (qcow2_opts->data_file_raw && qcow2_opts->has_backing_file) { 3159 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3160 "the same time"); 3161 ret = -EINVAL; 3162 goto out; 3163 } 3164 3165 if (qcow2_opts->data_file) { 3166 if (version < 3) { 3167 error_setg(errp, "External data files are only supported with " 3168 "compatibility level 1.1 and above (use version=v3 or " 3169 "greater)"); 3170 ret = -EINVAL; 3171 goto out; 3172 } 3173 data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp); 3174 if (data_bs == NULL) { 3175 ret = -EIO; 3176 goto out; 3177 } 3178 } 3179 3180 /* Create BlockBackend to write to the image */ 3181 blk = blk_new(bdrv_get_aio_context(bs), 3182 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 3183 ret = blk_insert_bs(blk, bs, errp); 3184 if (ret < 0) { 3185 goto out; 3186 } 3187 blk_set_allow_write_beyond_eof(blk, true); 3188 3189 /* Clear the protocol layer and preallocate it if necessary */ 3190 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp); 3191 if (ret < 0) { 3192 goto out; 3193 } 3194 3195 /* Write the header */ 3196 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3197 header = g_malloc0(cluster_size); 3198 *header = (QCowHeader) { 3199 .magic = cpu_to_be32(QCOW_MAGIC), 3200 .version = cpu_to_be32(version), 3201 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3202 .size = cpu_to_be64(0), 3203 .l1_table_offset = cpu_to_be64(0), 3204 .l1_size = cpu_to_be32(0), 3205 .refcount_table_offset = cpu_to_be64(cluster_size), 3206 .refcount_table_clusters = cpu_to_be32(1), 3207 .refcount_order = cpu_to_be32(refcount_order), 3208 .header_length = cpu_to_be32(sizeof(*header)), 3209 }; 3210 3211 /* We'll update this to correct value later */ 3212 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3213 3214 if (qcow2_opts->lazy_refcounts) { 3215 header->compatible_features |= 3216 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3217 } 3218 if (data_bs) { 3219 header->incompatible_features |= 3220 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3221 } 3222 if (qcow2_opts->data_file_raw) { 3223 header->autoclear_features |= 3224 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3225 } 3226 3227 ret = blk_pwrite(blk, 0, header, cluster_size, 0); 3228 g_free(header); 3229 if (ret < 0) { 3230 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3231 goto out; 3232 } 3233 3234 /* Write a refcount table with one refcount block */ 3235 refcount_table = g_malloc0(2 * cluster_size); 3236 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3237 ret = blk_pwrite(blk, cluster_size, refcount_table, 2 * cluster_size, 0); 3238 g_free(refcount_table); 3239 3240 if (ret < 0) { 3241 error_setg_errno(errp, -ret, "Could not write refcount table"); 3242 goto out; 3243 } 3244 3245 blk_unref(blk); 3246 blk = NULL; 3247 3248 /* 3249 * And now open the image and make it consistent first (i.e. increase the 3250 * refcount of the cluster that is occupied by the header and the refcount 3251 * table) 3252 */ 3253 options = qdict_new(); 3254 qdict_put_str(options, "driver", "qcow2"); 3255 qdict_put_str(options, "file", bs->node_name); 3256 if (data_bs) { 3257 qdict_put_str(options, "data-file", data_bs->node_name); 3258 } 3259 blk = blk_new_open(NULL, NULL, options, 3260 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3261 &local_err); 3262 if (blk == NULL) { 3263 error_propagate(errp, local_err); 3264 ret = -EIO; 3265 goto out; 3266 } 3267 3268 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3269 if (ret < 0) { 3270 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3271 "header and refcount table"); 3272 goto out; 3273 3274 } else if (ret != 0) { 3275 error_report("Huh, first cluster in empty image is already in use?"); 3276 abort(); 3277 } 3278 3279 /* Set the external data file if necessary */ 3280 if (data_bs) { 3281 BDRVQcow2State *s = blk_bs(blk)->opaque; 3282 s->image_data_file = g_strdup(data_bs->filename); 3283 } 3284 3285 /* Create a full header (including things like feature table) */ 3286 ret = qcow2_update_header(blk_bs(blk)); 3287 if (ret < 0) { 3288 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3289 goto out; 3290 } 3291 3292 /* Okay, now that we have a valid image, let's give it the right size */ 3293 ret = blk_truncate(blk, qcow2_opts->size, qcow2_opts->preallocation, errp); 3294 if (ret < 0) { 3295 error_prepend(errp, "Could not resize image: "); 3296 goto out; 3297 } 3298 3299 /* Want a backing file? There you go.*/ 3300 if (qcow2_opts->has_backing_file) { 3301 const char *backing_format = NULL; 3302 3303 if (qcow2_opts->has_backing_fmt) { 3304 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3305 } 3306 3307 ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3308 backing_format); 3309 if (ret < 0) { 3310 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3311 "with format '%s'", qcow2_opts->backing_file, 3312 backing_format); 3313 goto out; 3314 } 3315 } 3316 3317 /* Want encryption? There you go. */ 3318 if (qcow2_opts->has_encrypt) { 3319 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3320 if (ret < 0) { 3321 goto out; 3322 } 3323 } 3324 3325 blk_unref(blk); 3326 blk = NULL; 3327 3328 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3329 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3330 * have to setup decryption context. We're not doing any I/O on the top 3331 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3332 * not have effect. 3333 */ 3334 options = qdict_new(); 3335 qdict_put_str(options, "driver", "qcow2"); 3336 qdict_put_str(options, "file", bs->node_name); 3337 if (data_bs) { 3338 qdict_put_str(options, "data-file", data_bs->node_name); 3339 } 3340 blk = blk_new_open(NULL, NULL, options, 3341 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3342 &local_err); 3343 if (blk == NULL) { 3344 error_propagate(errp, local_err); 3345 ret = -EIO; 3346 goto out; 3347 } 3348 3349 ret = 0; 3350 out: 3351 blk_unref(blk); 3352 bdrv_unref(bs); 3353 bdrv_unref(data_bs); 3354 return ret; 3355 } 3356 3357 static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opts, 3358 Error **errp) 3359 { 3360 BlockdevCreateOptions *create_options = NULL; 3361 QDict *qdict; 3362 Visitor *v; 3363 BlockDriverState *bs = NULL; 3364 BlockDriverState *data_bs = NULL; 3365 Error *local_err = NULL; 3366 const char *val; 3367 int ret; 3368 3369 /* Only the keyval visitor supports the dotted syntax needed for 3370 * encryption, so go through a QDict before getting a QAPI type. Ignore 3371 * options meant for the protocol layer so that the visitor doesn't 3372 * complain. */ 3373 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3374 true); 3375 3376 /* Handle encryption options */ 3377 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3378 if (val && !strcmp(val, "on")) { 3379 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3380 } else if (val && !strcmp(val, "off")) { 3381 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3382 } 3383 3384 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3385 if (val && !strcmp(val, "aes")) { 3386 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3387 } 3388 3389 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3390 * version=v2/v3 below. */ 3391 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3392 if (val && !strcmp(val, "0.10")) { 3393 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3394 } else if (val && !strcmp(val, "1.1")) { 3395 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3396 } 3397 3398 /* Change legacy command line options into QMP ones */ 3399 static const QDictRenames opt_renames[] = { 3400 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3401 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3402 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3403 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3404 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3405 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3406 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3407 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3408 { NULL, NULL }, 3409 }; 3410 3411 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3412 ret = -EINVAL; 3413 goto finish; 3414 } 3415 3416 /* Create and open the file (protocol layer) */ 3417 ret = bdrv_create_file(filename, opts, errp); 3418 if (ret < 0) { 3419 goto finish; 3420 } 3421 3422 bs = bdrv_open(filename, NULL, NULL, 3423 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3424 if (bs == NULL) { 3425 ret = -EIO; 3426 goto finish; 3427 } 3428 3429 /* Create and open an external data file (protocol layer) */ 3430 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3431 if (val) { 3432 ret = bdrv_create_file(val, opts, errp); 3433 if (ret < 0) { 3434 goto finish; 3435 } 3436 3437 data_bs = bdrv_open(val, NULL, NULL, 3438 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3439 errp); 3440 if (data_bs == NULL) { 3441 ret = -EIO; 3442 goto finish; 3443 } 3444 3445 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3446 qdict_put_str(qdict, "data-file", data_bs->node_name); 3447 } 3448 3449 /* Set 'driver' and 'node' options */ 3450 qdict_put_str(qdict, "driver", "qcow2"); 3451 qdict_put_str(qdict, "file", bs->node_name); 3452 3453 /* Now get the QAPI type BlockdevCreateOptions */ 3454 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3455 if (!v) { 3456 ret = -EINVAL; 3457 goto finish; 3458 } 3459 3460 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 3461 visit_free(v); 3462 3463 if (local_err) { 3464 error_propagate(errp, local_err); 3465 ret = -EINVAL; 3466 goto finish; 3467 } 3468 3469 /* Silently round up size */ 3470 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 3471 BDRV_SECTOR_SIZE); 3472 3473 /* Create the qcow2 image (format layer) */ 3474 ret = qcow2_co_create(create_options, errp); 3475 if (ret < 0) { 3476 goto finish; 3477 } 3478 3479 ret = 0; 3480 finish: 3481 qobject_unref(qdict); 3482 bdrv_unref(bs); 3483 bdrv_unref(data_bs); 3484 qapi_free_BlockdevCreateOptions(create_options); 3485 return ret; 3486 } 3487 3488 3489 static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 3490 { 3491 int64_t nr; 3492 int res; 3493 3494 /* Clamp to image length, before checking status of underlying sectors */ 3495 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 3496 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 3497 } 3498 3499 if (!bytes) { 3500 return true; 3501 } 3502 res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 3503 return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; 3504 } 3505 3506 static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, 3507 int64_t offset, int bytes, BdrvRequestFlags flags) 3508 { 3509 int ret; 3510 BDRVQcow2State *s = bs->opaque; 3511 3512 uint32_t head = offset % s->cluster_size; 3513 uint32_t tail = (offset + bytes) % s->cluster_size; 3514 3515 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 3516 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 3517 tail = 0; 3518 } 3519 3520 if (head || tail) { 3521 uint64_t off; 3522 unsigned int nr; 3523 3524 assert(head + bytes <= s->cluster_size); 3525 3526 /* check whether remainder of cluster already reads as zero */ 3527 if (!(is_zero(bs, offset - head, head) && 3528 is_zero(bs, offset + bytes, 3529 tail ? s->cluster_size - tail : 0))) { 3530 return -ENOTSUP; 3531 } 3532 3533 qemu_co_mutex_lock(&s->lock); 3534 /* We can have new write after previous check */ 3535 offset = QEMU_ALIGN_DOWN(offset, s->cluster_size); 3536 bytes = s->cluster_size; 3537 nr = s->cluster_size; 3538 ret = qcow2_get_cluster_offset(bs, offset, &nr, &off); 3539 if (ret != QCOW2_CLUSTER_UNALLOCATED && 3540 ret != QCOW2_CLUSTER_ZERO_PLAIN && 3541 ret != QCOW2_CLUSTER_ZERO_ALLOC) { 3542 qemu_co_mutex_unlock(&s->lock); 3543 return -ENOTSUP; 3544 } 3545 } else { 3546 qemu_co_mutex_lock(&s->lock); 3547 } 3548 3549 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 3550 3551 /* Whatever is left can use real zero clusters */ 3552 ret = qcow2_cluster_zeroize(bs, offset, bytes, flags); 3553 qemu_co_mutex_unlock(&s->lock); 3554 3555 return ret; 3556 } 3557 3558 static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs, 3559 int64_t offset, int bytes) 3560 { 3561 int ret; 3562 BDRVQcow2State *s = bs->opaque; 3563 3564 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 3565 assert(bytes < s->cluster_size); 3566 /* Ignore partial clusters, except for the special case of the 3567 * complete partial cluster at the end of an unaligned file */ 3568 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 3569 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 3570 return -ENOTSUP; 3571 } 3572 } 3573 3574 qemu_co_mutex_lock(&s->lock); 3575 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 3576 false); 3577 qemu_co_mutex_unlock(&s->lock); 3578 return ret; 3579 } 3580 3581 static int coroutine_fn 3582 qcow2_co_copy_range_from(BlockDriverState *bs, 3583 BdrvChild *src, uint64_t src_offset, 3584 BdrvChild *dst, uint64_t dst_offset, 3585 uint64_t bytes, BdrvRequestFlags read_flags, 3586 BdrvRequestFlags write_flags) 3587 { 3588 BDRVQcow2State *s = bs->opaque; 3589 int ret; 3590 unsigned int cur_bytes; /* number of bytes in current iteration */ 3591 BdrvChild *child = NULL; 3592 BdrvRequestFlags cur_write_flags; 3593 3594 assert(!bs->encrypted); 3595 qemu_co_mutex_lock(&s->lock); 3596 3597 while (bytes != 0) { 3598 uint64_t copy_offset = 0; 3599 /* prepare next request */ 3600 cur_bytes = MIN(bytes, INT_MAX); 3601 cur_write_flags = write_flags; 3602 3603 ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, ©_offset); 3604 if (ret < 0) { 3605 goto out; 3606 } 3607 3608 switch (ret) { 3609 case QCOW2_CLUSTER_UNALLOCATED: 3610 if (bs->backing && bs->backing->bs) { 3611 int64_t backing_length = bdrv_getlength(bs->backing->bs); 3612 if (src_offset >= backing_length) { 3613 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3614 } else { 3615 child = bs->backing; 3616 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 3617 copy_offset = src_offset; 3618 } 3619 } else { 3620 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3621 } 3622 break; 3623 3624 case QCOW2_CLUSTER_ZERO_PLAIN: 3625 case QCOW2_CLUSTER_ZERO_ALLOC: 3626 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3627 break; 3628 3629 case QCOW2_CLUSTER_COMPRESSED: 3630 ret = -ENOTSUP; 3631 goto out; 3632 3633 case QCOW2_CLUSTER_NORMAL: 3634 child = s->data_file; 3635 copy_offset += offset_into_cluster(s, src_offset); 3636 if ((copy_offset & 511) != 0) { 3637 ret = -EIO; 3638 goto out; 3639 } 3640 break; 3641 3642 default: 3643 abort(); 3644 } 3645 qemu_co_mutex_unlock(&s->lock); 3646 ret = bdrv_co_copy_range_from(child, 3647 copy_offset, 3648 dst, dst_offset, 3649 cur_bytes, read_flags, cur_write_flags); 3650 qemu_co_mutex_lock(&s->lock); 3651 if (ret < 0) { 3652 goto out; 3653 } 3654 3655 bytes -= cur_bytes; 3656 src_offset += cur_bytes; 3657 dst_offset += cur_bytes; 3658 } 3659 ret = 0; 3660 3661 out: 3662 qemu_co_mutex_unlock(&s->lock); 3663 return ret; 3664 } 3665 3666 static int coroutine_fn 3667 qcow2_co_copy_range_to(BlockDriverState *bs, 3668 BdrvChild *src, uint64_t src_offset, 3669 BdrvChild *dst, uint64_t dst_offset, 3670 uint64_t bytes, BdrvRequestFlags read_flags, 3671 BdrvRequestFlags write_flags) 3672 { 3673 BDRVQcow2State *s = bs->opaque; 3674 int offset_in_cluster; 3675 int ret; 3676 unsigned int cur_bytes; /* number of sectors in current iteration */ 3677 uint64_t cluster_offset; 3678 QCowL2Meta *l2meta = NULL; 3679 3680 assert(!bs->encrypted); 3681 3682 qemu_co_mutex_lock(&s->lock); 3683 3684 while (bytes != 0) { 3685 3686 l2meta = NULL; 3687 3688 offset_in_cluster = offset_into_cluster(s, dst_offset); 3689 cur_bytes = MIN(bytes, INT_MAX); 3690 3691 /* TODO: 3692 * If src->bs == dst->bs, we could simply copy by incrementing 3693 * the refcnt, without copying user data. 3694 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 3695 ret = qcow2_alloc_cluster_offset(bs, dst_offset, &cur_bytes, 3696 &cluster_offset, &l2meta); 3697 if (ret < 0) { 3698 goto fail; 3699 } 3700 3701 assert((cluster_offset & 511) == 0); 3702 3703 ret = qcow2_pre_write_overlap_check(bs, 0, 3704 cluster_offset + offset_in_cluster, cur_bytes, true); 3705 if (ret < 0) { 3706 goto fail; 3707 } 3708 3709 qemu_co_mutex_unlock(&s->lock); 3710 ret = bdrv_co_copy_range_to(src, src_offset, 3711 s->data_file, 3712 cluster_offset + offset_in_cluster, 3713 cur_bytes, read_flags, write_flags); 3714 qemu_co_mutex_lock(&s->lock); 3715 if (ret < 0) { 3716 goto fail; 3717 } 3718 3719 ret = qcow2_handle_l2meta(bs, &l2meta, true); 3720 if (ret) { 3721 goto fail; 3722 } 3723 3724 bytes -= cur_bytes; 3725 src_offset += cur_bytes; 3726 dst_offset += cur_bytes; 3727 } 3728 ret = 0; 3729 3730 fail: 3731 qcow2_handle_l2meta(bs, &l2meta, false); 3732 3733 qemu_co_mutex_unlock(&s->lock); 3734 3735 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 3736 3737 return ret; 3738 } 3739 3740 static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, 3741 PreallocMode prealloc, Error **errp) 3742 { 3743 BDRVQcow2State *s = bs->opaque; 3744 uint64_t old_length; 3745 int64_t new_l1_size; 3746 int ret; 3747 QDict *options; 3748 3749 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 3750 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 3751 { 3752 error_setg(errp, "Unsupported preallocation mode '%s'", 3753 PreallocMode_str(prealloc)); 3754 return -ENOTSUP; 3755 } 3756 3757 if (offset & 511) { 3758 error_setg(errp, "The new size must be a multiple of 512"); 3759 return -EINVAL; 3760 } 3761 3762 qemu_co_mutex_lock(&s->lock); 3763 3764 /* cannot proceed if image has snapshots */ 3765 if (s->nb_snapshots) { 3766 error_setg(errp, "Can't resize an image which has snapshots"); 3767 ret = -ENOTSUP; 3768 goto fail; 3769 } 3770 3771 /* cannot proceed if image has bitmaps */ 3772 if (qcow2_truncate_bitmaps_check(bs, errp)) { 3773 ret = -ENOTSUP; 3774 goto fail; 3775 } 3776 3777 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 3778 new_l1_size = size_to_l1(s, offset); 3779 3780 if (offset < old_length) { 3781 int64_t last_cluster, old_file_size; 3782 if (prealloc != PREALLOC_MODE_OFF) { 3783 error_setg(errp, 3784 "Preallocation can't be used for shrinking an image"); 3785 ret = -EINVAL; 3786 goto fail; 3787 } 3788 3789 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 3790 old_length - ROUND_UP(offset, 3791 s->cluster_size), 3792 QCOW2_DISCARD_ALWAYS, true); 3793 if (ret < 0) { 3794 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 3795 goto fail; 3796 } 3797 3798 ret = qcow2_shrink_l1_table(bs, new_l1_size); 3799 if (ret < 0) { 3800 error_setg_errno(errp, -ret, 3801 "Failed to reduce the number of L2 tables"); 3802 goto fail; 3803 } 3804 3805 ret = qcow2_shrink_reftable(bs); 3806 if (ret < 0) { 3807 error_setg_errno(errp, -ret, 3808 "Failed to discard unused refblocks"); 3809 goto fail; 3810 } 3811 3812 old_file_size = bdrv_getlength(bs->file->bs); 3813 if (old_file_size < 0) { 3814 error_setg_errno(errp, -old_file_size, 3815 "Failed to inquire current file length"); 3816 ret = old_file_size; 3817 goto fail; 3818 } 3819 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 3820 if (last_cluster < 0) { 3821 error_setg_errno(errp, -last_cluster, 3822 "Failed to find the last cluster"); 3823 ret = last_cluster; 3824 goto fail; 3825 } 3826 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 3827 Error *local_err = NULL; 3828 3829 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 3830 PREALLOC_MODE_OFF, &local_err); 3831 if (local_err) { 3832 warn_reportf_err(local_err, 3833 "Failed to truncate the tail of the image: "); 3834 } 3835 } 3836 } else { 3837 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 3838 if (ret < 0) { 3839 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 3840 goto fail; 3841 } 3842 } 3843 3844 switch (prealloc) { 3845 case PREALLOC_MODE_OFF: 3846 if (has_data_file(bs)) { 3847 ret = bdrv_co_truncate(s->data_file, offset, prealloc, errp); 3848 if (ret < 0) { 3849 goto fail; 3850 } 3851 } 3852 break; 3853 3854 case PREALLOC_MODE_METADATA: 3855 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 3856 if (ret < 0) { 3857 goto fail; 3858 } 3859 break; 3860 3861 case PREALLOC_MODE_FALLOC: 3862 case PREALLOC_MODE_FULL: 3863 { 3864 int64_t allocation_start, host_offset, guest_offset; 3865 int64_t clusters_allocated; 3866 int64_t old_file_size, new_file_size; 3867 uint64_t nb_new_data_clusters, nb_new_l2_tables; 3868 3869 /* With a data file, preallocation means just allocating the metadata 3870 * and forwarding the truncate request to the data file */ 3871 if (has_data_file(bs)) { 3872 ret = preallocate_co(bs, old_length, offset, prealloc, errp); 3873 if (ret < 0) { 3874 goto fail; 3875 } 3876 break; 3877 } 3878 3879 old_file_size = bdrv_getlength(bs->file->bs); 3880 if (old_file_size < 0) { 3881 error_setg_errno(errp, -old_file_size, 3882 "Failed to inquire current file length"); 3883 ret = old_file_size; 3884 goto fail; 3885 } 3886 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 3887 3888 nb_new_data_clusters = DIV_ROUND_UP(offset - old_length, 3889 s->cluster_size); 3890 3891 /* This is an overestimation; we will not actually allocate space for 3892 * these in the file but just make sure the new refcount structures are 3893 * able to cover them so we will not have to allocate new refblocks 3894 * while entering the data blocks in the potentially new L2 tables. 3895 * (We do not actually care where the L2 tables are placed. Maybe they 3896 * are already allocated or they can be placed somewhere before 3897 * @old_file_size. It does not matter because they will be fully 3898 * allocated automatically, so they do not need to be covered by the 3899 * preallocation. All that matters is that we will not have to allocate 3900 * new refcount structures for them.) */ 3901 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 3902 s->cluster_size / sizeof(uint64_t)); 3903 /* The cluster range may not be aligned to L2 boundaries, so add one L2 3904 * table for a potential head/tail */ 3905 nb_new_l2_tables++; 3906 3907 allocation_start = qcow2_refcount_area(bs, old_file_size, 3908 nb_new_data_clusters + 3909 nb_new_l2_tables, 3910 true, 0, 0); 3911 if (allocation_start < 0) { 3912 error_setg_errno(errp, -allocation_start, 3913 "Failed to resize refcount structures"); 3914 ret = allocation_start; 3915 goto fail; 3916 } 3917 3918 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 3919 nb_new_data_clusters); 3920 if (clusters_allocated < 0) { 3921 error_setg_errno(errp, -clusters_allocated, 3922 "Failed to allocate data clusters"); 3923 ret = clusters_allocated; 3924 goto fail; 3925 } 3926 3927 assert(clusters_allocated == nb_new_data_clusters); 3928 3929 /* Allocate the data area */ 3930 new_file_size = allocation_start + 3931 nb_new_data_clusters * s->cluster_size; 3932 ret = bdrv_co_truncate(bs->file, new_file_size, prealloc, errp); 3933 if (ret < 0) { 3934 error_prepend(errp, "Failed to resize underlying file: "); 3935 qcow2_free_clusters(bs, allocation_start, 3936 nb_new_data_clusters * s->cluster_size, 3937 QCOW2_DISCARD_OTHER); 3938 goto fail; 3939 } 3940 3941 /* Create the necessary L2 entries */ 3942 host_offset = allocation_start; 3943 guest_offset = old_length; 3944 while (nb_new_data_clusters) { 3945 int64_t nb_clusters = MIN( 3946 nb_new_data_clusters, 3947 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 3948 QCowL2Meta allocation = { 3949 .offset = guest_offset, 3950 .alloc_offset = host_offset, 3951 .nb_clusters = nb_clusters, 3952 }; 3953 qemu_co_queue_init(&allocation.dependent_requests); 3954 3955 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 3956 if (ret < 0) { 3957 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 3958 qcow2_free_clusters(bs, host_offset, 3959 nb_new_data_clusters * s->cluster_size, 3960 QCOW2_DISCARD_OTHER); 3961 goto fail; 3962 } 3963 3964 guest_offset += nb_clusters * s->cluster_size; 3965 host_offset += nb_clusters * s->cluster_size; 3966 nb_new_data_clusters -= nb_clusters; 3967 } 3968 break; 3969 } 3970 3971 default: 3972 g_assert_not_reached(); 3973 } 3974 3975 if (prealloc != PREALLOC_MODE_OFF) { 3976 /* Flush metadata before actually changing the image size */ 3977 ret = qcow2_write_caches(bs); 3978 if (ret < 0) { 3979 error_setg_errno(errp, -ret, 3980 "Failed to flush the preallocated area to disk"); 3981 goto fail; 3982 } 3983 } 3984 3985 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 3986 3987 /* write updated header.size */ 3988 offset = cpu_to_be64(offset); 3989 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), 3990 &offset, sizeof(uint64_t)); 3991 if (ret < 0) { 3992 error_setg_errno(errp, -ret, "Failed to update the image size"); 3993 goto fail; 3994 } 3995 3996 s->l1_vm_state_index = new_l1_size; 3997 3998 /* Update cache sizes */ 3999 options = qdict_clone_shallow(bs->options); 4000 ret = qcow2_update_options(bs, options, s->flags, errp); 4001 qobject_unref(options); 4002 if (ret < 0) { 4003 goto fail; 4004 } 4005 ret = 0; 4006 fail: 4007 qemu_co_mutex_unlock(&s->lock); 4008 return ret; 4009 } 4010 4011 /* XXX: put compressed sectors first, then all the cluster aligned 4012 tables to avoid losing bytes in alignment */ 4013 static coroutine_fn int 4014 qcow2_co_pwritev_compressed_part(BlockDriverState *bs, 4015 uint64_t offset, uint64_t bytes, 4016 QEMUIOVector *qiov, size_t qiov_offset) 4017 { 4018 BDRVQcow2State *s = bs->opaque; 4019 int ret; 4020 ssize_t out_len; 4021 uint8_t *buf, *out_buf; 4022 uint64_t cluster_offset; 4023 4024 if (has_data_file(bs)) { 4025 return -ENOTSUP; 4026 } 4027 4028 if (bytes == 0) { 4029 /* align end of file to a sector boundary to ease reading with 4030 sector based I/Os */ 4031 int64_t len = bdrv_getlength(bs->file->bs); 4032 if (len < 0) { 4033 return len; 4034 } 4035 return bdrv_co_truncate(bs->file, len, PREALLOC_MODE_OFF, NULL); 4036 } 4037 4038 if (offset_into_cluster(s, offset)) { 4039 return -EINVAL; 4040 } 4041 4042 buf = qemu_blockalign(bs, s->cluster_size); 4043 if (bytes != s->cluster_size) { 4044 if (bytes > s->cluster_size || 4045 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS) 4046 { 4047 qemu_vfree(buf); 4048 return -EINVAL; 4049 } 4050 /* Zero-pad last write if image size is not cluster aligned */ 4051 memset(buf + bytes, 0, s->cluster_size - bytes); 4052 } 4053 qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); 4054 4055 out_buf = g_malloc(s->cluster_size); 4056 4057 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4058 buf, s->cluster_size); 4059 if (out_len == -ENOMEM) { 4060 /* could not compress: write normal cluster */ 4061 ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); 4062 if (ret < 0) { 4063 goto fail; 4064 } 4065 goto success; 4066 } else if (out_len < 0) { 4067 ret = -EINVAL; 4068 goto fail; 4069 } 4070 4071 qemu_co_mutex_lock(&s->lock); 4072 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4073 &cluster_offset); 4074 if (ret < 0) { 4075 qemu_co_mutex_unlock(&s->lock); 4076 goto fail; 4077 } 4078 4079 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4080 qemu_co_mutex_unlock(&s->lock); 4081 if (ret < 0) { 4082 goto fail; 4083 } 4084 4085 BLKDBG_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4086 ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); 4087 if (ret < 0) { 4088 goto fail; 4089 } 4090 success: 4091 ret = 0; 4092 fail: 4093 qemu_vfree(buf); 4094 g_free(out_buf); 4095 return ret; 4096 } 4097 4098 static int coroutine_fn 4099 qcow2_co_preadv_compressed(BlockDriverState *bs, 4100 uint64_t file_cluster_offset, 4101 uint64_t offset, 4102 uint64_t bytes, 4103 QEMUIOVector *qiov, 4104 size_t qiov_offset) 4105 { 4106 BDRVQcow2State *s = bs->opaque; 4107 int ret = 0, csize, nb_csectors; 4108 uint64_t coffset; 4109 uint8_t *buf, *out_buf; 4110 int offset_in_cluster = offset_into_cluster(s, offset); 4111 4112 coffset = file_cluster_offset & s->cluster_offset_mask; 4113 nb_csectors = ((file_cluster_offset >> s->csize_shift) & s->csize_mask) + 1; 4114 csize = nb_csectors * QCOW2_COMPRESSED_SECTOR_SIZE - 4115 (coffset & ~QCOW2_COMPRESSED_SECTOR_MASK); 4116 4117 buf = g_try_malloc(csize); 4118 if (!buf) { 4119 return -ENOMEM; 4120 } 4121 4122 out_buf = qemu_blockalign(bs, s->cluster_size); 4123 4124 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4125 ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0); 4126 if (ret < 0) { 4127 goto fail; 4128 } 4129 4130 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4131 ret = -EIO; 4132 goto fail; 4133 } 4134 4135 qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); 4136 4137 fail: 4138 qemu_vfree(out_buf); 4139 g_free(buf); 4140 4141 return ret; 4142 } 4143 4144 static int make_completely_empty(BlockDriverState *bs) 4145 { 4146 BDRVQcow2State *s = bs->opaque; 4147 Error *local_err = NULL; 4148 int ret, l1_clusters; 4149 int64_t offset; 4150 uint64_t *new_reftable = NULL; 4151 uint64_t rt_entry, l1_size2; 4152 struct { 4153 uint64_t l1_offset; 4154 uint64_t reftable_offset; 4155 uint32_t reftable_clusters; 4156 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4157 4158 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4159 if (ret < 0) { 4160 goto fail; 4161 } 4162 4163 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4164 if (ret < 0) { 4165 goto fail; 4166 } 4167 4168 /* Refcounts will be broken utterly */ 4169 ret = qcow2_mark_dirty(bs); 4170 if (ret < 0) { 4171 goto fail; 4172 } 4173 4174 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4175 4176 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4177 l1_size2 = (uint64_t)s->l1_size * sizeof(uint64_t); 4178 4179 /* After this call, neither the in-memory nor the on-disk refcount 4180 * information accurately describe the actual references */ 4181 4182 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4183 l1_clusters * s->cluster_size, 0); 4184 if (ret < 0) { 4185 goto fail_broken_refcounts; 4186 } 4187 memset(s->l1_table, 0, l1_size2); 4188 4189 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4190 4191 /* Overwrite enough clusters at the beginning of the sectors to place 4192 * the refcount table, a refcount block and the L1 table in; this may 4193 * overwrite parts of the existing refcount and L1 table, which is not 4194 * an issue because the dirty flag is set, complete data loss is in fact 4195 * desired and partial data loss is consequently fine as well */ 4196 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4197 (2 + l1_clusters) * s->cluster_size, 0); 4198 /* This call (even if it failed overall) may have overwritten on-disk 4199 * refcount structures; in that case, the in-memory refcount information 4200 * will probably differ from the on-disk information which makes the BDS 4201 * unusable */ 4202 if (ret < 0) { 4203 goto fail_broken_refcounts; 4204 } 4205 4206 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4207 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4208 4209 /* "Create" an empty reftable (one cluster) directly after the image 4210 * header and an empty L1 table three clusters after the image header; 4211 * the cluster between those two will be used as the first refblock */ 4212 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4213 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4214 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4215 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4216 &l1_ofs_rt_ofs_cls, sizeof(l1_ofs_rt_ofs_cls)); 4217 if (ret < 0) { 4218 goto fail_broken_refcounts; 4219 } 4220 4221 s->l1_table_offset = 3 * s->cluster_size; 4222 4223 new_reftable = g_try_new0(uint64_t, s->cluster_size / sizeof(uint64_t)); 4224 if (!new_reftable) { 4225 ret = -ENOMEM; 4226 goto fail_broken_refcounts; 4227 } 4228 4229 s->refcount_table_offset = s->cluster_size; 4230 s->refcount_table_size = s->cluster_size / sizeof(uint64_t); 4231 s->max_refcount_table_index = 0; 4232 4233 g_free(s->refcount_table); 4234 s->refcount_table = new_reftable; 4235 new_reftable = NULL; 4236 4237 /* Now the in-memory refcount information again corresponds to the on-disk 4238 * information (reftable is empty and no refblocks (the refblock cache is 4239 * empty)); however, this means some clusters (e.g. the image header) are 4240 * referenced, but not refcounted, but the normal qcow2 code assumes that 4241 * the in-memory information is always correct */ 4242 4243 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4244 4245 /* Enter the first refblock into the reftable */ 4246 rt_entry = cpu_to_be64(2 * s->cluster_size); 4247 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, 4248 &rt_entry, sizeof(rt_entry)); 4249 if (ret < 0) { 4250 goto fail_broken_refcounts; 4251 } 4252 s->refcount_table[0] = 2 * s->cluster_size; 4253 4254 s->free_cluster_index = 0; 4255 assert(3 + l1_clusters <= s->refcount_block_size); 4256 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4257 if (offset < 0) { 4258 ret = offset; 4259 goto fail_broken_refcounts; 4260 } else if (offset > 0) { 4261 error_report("First cluster in emptied image is in use"); 4262 abort(); 4263 } 4264 4265 /* Now finally the in-memory information corresponds to the on-disk 4266 * structures and is correct */ 4267 ret = qcow2_mark_clean(bs); 4268 if (ret < 0) { 4269 goto fail; 4270 } 4271 4272 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, 4273 PREALLOC_MODE_OFF, &local_err); 4274 if (ret < 0) { 4275 error_report_err(local_err); 4276 goto fail; 4277 } 4278 4279 return 0; 4280 4281 fail_broken_refcounts: 4282 /* The BDS is unusable at this point. If we wanted to make it usable, we 4283 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 4284 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 4285 * again. However, because the functions which could have caused this error 4286 * path to be taken are used by those functions as well, it's very likely 4287 * that that sequence will fail as well. Therefore, just eject the BDS. */ 4288 bs->drv = NULL; 4289 4290 fail: 4291 g_free(new_reftable); 4292 return ret; 4293 } 4294 4295 static int qcow2_make_empty(BlockDriverState *bs) 4296 { 4297 BDRVQcow2State *s = bs->opaque; 4298 uint64_t offset, end_offset; 4299 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 4300 int l1_clusters, ret = 0; 4301 4302 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4303 4304 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 4305 3 + l1_clusters <= s->refcount_block_size && 4306 s->crypt_method_header != QCOW_CRYPT_LUKS && 4307 !has_data_file(bs)) { 4308 /* The following function only works for qcow2 v3 images (it 4309 * requires the dirty flag) and only as long as there are no 4310 * features that reserve extra clusters (such as snapshots, 4311 * LUKS header, or persistent bitmaps), because it completely 4312 * empties the image. Furthermore, the L1 table and three 4313 * additional clusters (image header, refcount table, one 4314 * refcount block) have to fit inside one refcount block. It 4315 * only resets the image file, i.e. does not work with an 4316 * external data file. */ 4317 return make_completely_empty(bs); 4318 } 4319 4320 /* This fallback code simply discards every active cluster; this is slow, 4321 * but works in all cases */ 4322 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 4323 for (offset = 0; offset < end_offset; offset += step) { 4324 /* As this function is generally used after committing an external 4325 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 4326 * default action for this kind of discard is to pass the discard, 4327 * which will ideally result in an actually smaller image file, as 4328 * is probably desired. */ 4329 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 4330 QCOW2_DISCARD_SNAPSHOT, true); 4331 if (ret < 0) { 4332 break; 4333 } 4334 } 4335 4336 return ret; 4337 } 4338 4339 static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) 4340 { 4341 BDRVQcow2State *s = bs->opaque; 4342 int ret; 4343 4344 qemu_co_mutex_lock(&s->lock); 4345 ret = qcow2_write_caches(bs); 4346 qemu_co_mutex_unlock(&s->lock); 4347 4348 return ret; 4349 } 4350 4351 static ssize_t qcow2_measure_crypto_hdr_init_func(QCryptoBlock *block, 4352 size_t headerlen, void *opaque, Error **errp) 4353 { 4354 size_t *headerlenp = opaque; 4355 4356 /* Stash away the payload size */ 4357 *headerlenp = headerlen; 4358 return 0; 4359 } 4360 4361 static ssize_t qcow2_measure_crypto_hdr_write_func(QCryptoBlock *block, 4362 size_t offset, const uint8_t *buf, size_t buflen, 4363 void *opaque, Error **errp) 4364 { 4365 /* Discard the bytes, we're not actually writing to an image */ 4366 return buflen; 4367 } 4368 4369 /* Determine the number of bytes for the LUKS payload */ 4370 static bool qcow2_measure_luks_headerlen(QemuOpts *opts, size_t *len, 4371 Error **errp) 4372 { 4373 QDict *opts_qdict; 4374 QDict *cryptoopts_qdict; 4375 QCryptoBlockCreateOptions *cryptoopts; 4376 QCryptoBlock *crypto; 4377 4378 /* Extract "encrypt." options into a qdict */ 4379 opts_qdict = qemu_opts_to_qdict(opts, NULL); 4380 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); 4381 qobject_unref(opts_qdict); 4382 4383 /* Build QCryptoBlockCreateOptions object from qdict */ 4384 qdict_put_str(cryptoopts_qdict, "format", "luks"); 4385 cryptoopts = block_crypto_create_opts_init(cryptoopts_qdict, errp); 4386 qobject_unref(cryptoopts_qdict); 4387 if (!cryptoopts) { 4388 return false; 4389 } 4390 4391 /* Fake LUKS creation in order to determine the payload size */ 4392 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 4393 qcow2_measure_crypto_hdr_init_func, 4394 qcow2_measure_crypto_hdr_write_func, 4395 len, errp); 4396 qapi_free_QCryptoBlockCreateOptions(cryptoopts); 4397 if (!crypto) { 4398 return false; 4399 } 4400 4401 qcrypto_block_free(crypto); 4402 return true; 4403 } 4404 4405 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 4406 Error **errp) 4407 { 4408 Error *local_err = NULL; 4409 BlockMeasureInfo *info; 4410 uint64_t required = 0; /* bytes that contribute to required size */ 4411 uint64_t virtual_size; /* disk size as seen by guest */ 4412 uint64_t refcount_bits; 4413 uint64_t l2_tables; 4414 uint64_t luks_payload_size = 0; 4415 size_t cluster_size; 4416 int version; 4417 char *optstr; 4418 PreallocMode prealloc; 4419 bool has_backing_file; 4420 bool has_luks; 4421 4422 /* Parse image creation options */ 4423 cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err); 4424 if (local_err) { 4425 goto err; 4426 } 4427 4428 version = qcow2_opt_get_version_del(opts, &local_err); 4429 if (local_err) { 4430 goto err; 4431 } 4432 4433 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 4434 if (local_err) { 4435 goto err; 4436 } 4437 4438 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 4439 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 4440 PREALLOC_MODE_OFF, &local_err); 4441 g_free(optstr); 4442 if (local_err) { 4443 goto err; 4444 } 4445 4446 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 4447 has_backing_file = !!optstr; 4448 g_free(optstr); 4449 4450 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 4451 has_luks = optstr && strcmp(optstr, "luks") == 0; 4452 g_free(optstr); 4453 4454 if (has_luks) { 4455 size_t headerlen; 4456 4457 if (!qcow2_measure_luks_headerlen(opts, &headerlen, &local_err)) { 4458 goto err; 4459 } 4460 4461 luks_payload_size = ROUND_UP(headerlen, cluster_size); 4462 } 4463 4464 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 4465 virtual_size = ROUND_UP(virtual_size, cluster_size); 4466 4467 /* Check that virtual disk size is valid */ 4468 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 4469 cluster_size / sizeof(uint64_t)); 4470 if (l2_tables * sizeof(uint64_t) > QCOW_MAX_L1_SIZE) { 4471 error_setg(&local_err, "The image size is too large " 4472 "(try using a larger cluster size)"); 4473 goto err; 4474 } 4475 4476 /* Account for input image */ 4477 if (in_bs) { 4478 int64_t ssize = bdrv_getlength(in_bs); 4479 if (ssize < 0) { 4480 error_setg_errno(&local_err, -ssize, 4481 "Unable to get image virtual_size"); 4482 goto err; 4483 } 4484 4485 virtual_size = ROUND_UP(ssize, cluster_size); 4486 4487 if (has_backing_file) { 4488 /* We don't how much of the backing chain is shared by the input 4489 * image and the new image file. In the worst case the new image's 4490 * backing file has nothing in common with the input image. Be 4491 * conservative and assume all clusters need to be written. 4492 */ 4493 required = virtual_size; 4494 } else { 4495 int64_t offset; 4496 int64_t pnum = 0; 4497 4498 for (offset = 0; offset < ssize; offset += pnum) { 4499 int ret; 4500 4501 ret = bdrv_block_status_above(in_bs, NULL, offset, 4502 ssize - offset, &pnum, NULL, 4503 NULL); 4504 if (ret < 0) { 4505 error_setg_errno(&local_err, -ret, 4506 "Unable to get block status"); 4507 goto err; 4508 } 4509 4510 if (ret & BDRV_BLOCK_ZERO) { 4511 /* Skip zero regions (safe with no backing file) */ 4512 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 4513 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 4514 /* Extend pnum to end of cluster for next iteration */ 4515 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 4516 4517 /* Count clusters we've seen */ 4518 required += offset % cluster_size + pnum; 4519 } 4520 } 4521 } 4522 } 4523 4524 /* Take into account preallocation. Nothing special is needed for 4525 * PREALLOC_MODE_METADATA since metadata is always counted. 4526 */ 4527 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 4528 required = virtual_size; 4529 } 4530 4531 info = g_new(BlockMeasureInfo, 1); 4532 info->fully_allocated = 4533 qcow2_calc_prealloc_size(virtual_size, cluster_size, 4534 ctz32(refcount_bits)) + luks_payload_size; 4535 4536 /* Remove data clusters that are not required. This overestimates the 4537 * required size because metadata needed for the fully allocated file is 4538 * still counted. 4539 */ 4540 info->required = info->fully_allocated - virtual_size + required; 4541 return info; 4542 4543 err: 4544 error_propagate(errp, local_err); 4545 return NULL; 4546 } 4547 4548 static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 4549 { 4550 BDRVQcow2State *s = bs->opaque; 4551 bdi->unallocated_blocks_are_zero = true; 4552 bdi->cluster_size = s->cluster_size; 4553 bdi->vm_state_offset = qcow2_vm_state_offset(s); 4554 return 0; 4555 } 4556 4557 static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs, 4558 Error **errp) 4559 { 4560 BDRVQcow2State *s = bs->opaque; 4561 ImageInfoSpecific *spec_info; 4562 QCryptoBlockInfo *encrypt_info = NULL; 4563 Error *local_err = NULL; 4564 4565 if (s->crypto != NULL) { 4566 encrypt_info = qcrypto_block_get_info(s->crypto, &local_err); 4567 if (local_err) { 4568 error_propagate(errp, local_err); 4569 return NULL; 4570 } 4571 } 4572 4573 spec_info = g_new(ImageInfoSpecific, 1); 4574 *spec_info = (ImageInfoSpecific){ 4575 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 4576 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 4577 }; 4578 if (s->qcow_version == 2) { 4579 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 4580 .compat = g_strdup("0.10"), 4581 .refcount_bits = s->refcount_bits, 4582 }; 4583 } else if (s->qcow_version == 3) { 4584 Qcow2BitmapInfoList *bitmaps; 4585 bitmaps = qcow2_get_bitmap_info_list(bs, &local_err); 4586 if (local_err) { 4587 error_propagate(errp, local_err); 4588 qapi_free_ImageInfoSpecific(spec_info); 4589 return NULL; 4590 } 4591 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 4592 .compat = g_strdup("1.1"), 4593 .lazy_refcounts = s->compatible_features & 4594 QCOW2_COMPAT_LAZY_REFCOUNTS, 4595 .has_lazy_refcounts = true, 4596 .corrupt = s->incompatible_features & 4597 QCOW2_INCOMPAT_CORRUPT, 4598 .has_corrupt = true, 4599 .refcount_bits = s->refcount_bits, 4600 .has_bitmaps = !!bitmaps, 4601 .bitmaps = bitmaps, 4602 .has_data_file = !!s->image_data_file, 4603 .data_file = g_strdup(s->image_data_file), 4604 .has_data_file_raw = has_data_file(bs), 4605 .data_file_raw = data_file_is_raw(bs), 4606 }; 4607 } else { 4608 /* if this assertion fails, this probably means a new version was 4609 * added without having it covered here */ 4610 assert(false); 4611 } 4612 4613 if (encrypt_info) { 4614 ImageInfoSpecificQCow2Encryption *qencrypt = 4615 g_new(ImageInfoSpecificQCow2Encryption, 1); 4616 switch (encrypt_info->format) { 4617 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 4618 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 4619 break; 4620 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 4621 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 4622 qencrypt->u.luks = encrypt_info->u.luks; 4623 break; 4624 default: 4625 abort(); 4626 } 4627 /* Since we did shallow copy above, erase any pointers 4628 * in the original info */ 4629 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 4630 qapi_free_QCryptoBlockInfo(encrypt_info); 4631 4632 spec_info->u.qcow2.data->has_encrypt = true; 4633 spec_info->u.qcow2.data->encrypt = qencrypt; 4634 } 4635 4636 return spec_info; 4637 } 4638 4639 static int qcow2_has_zero_init(BlockDriverState *bs) 4640 { 4641 BDRVQcow2State *s = bs->opaque; 4642 bool preallocated; 4643 4644 if (qemu_in_coroutine()) { 4645 qemu_co_mutex_lock(&s->lock); 4646 } 4647 /* 4648 * Check preallocation status: Preallocated images have all L2 4649 * tables allocated, nonpreallocated images have none. It is 4650 * therefore enough to check the first one. 4651 */ 4652 preallocated = s->l1_size > 0 && s->l1_table[0] != 0; 4653 if (qemu_in_coroutine()) { 4654 qemu_co_mutex_unlock(&s->lock); 4655 } 4656 4657 if (!preallocated) { 4658 return 1; 4659 } else if (bs->encrypted) { 4660 return 0; 4661 } else { 4662 return bdrv_has_zero_init(s->data_file->bs); 4663 } 4664 } 4665 4666 static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 4667 int64_t pos) 4668 { 4669 BDRVQcow2State *s = bs->opaque; 4670 4671 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 4672 return bs->drv->bdrv_co_pwritev_part(bs, qcow2_vm_state_offset(s) + pos, 4673 qiov->size, qiov, 0, 0); 4674 } 4675 4676 static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 4677 int64_t pos) 4678 { 4679 BDRVQcow2State *s = bs->opaque; 4680 4681 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 4682 return bs->drv->bdrv_co_preadv_part(bs, qcow2_vm_state_offset(s) + pos, 4683 qiov->size, qiov, 0, 0); 4684 } 4685 4686 /* 4687 * Downgrades an image's version. To achieve this, any incompatible features 4688 * have to be removed. 4689 */ 4690 static int qcow2_downgrade(BlockDriverState *bs, int target_version, 4691 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 4692 Error **errp) 4693 { 4694 BDRVQcow2State *s = bs->opaque; 4695 int current_version = s->qcow_version; 4696 int ret; 4697 4698 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 4699 assert(target_version < current_version); 4700 4701 /* There are no other versions (now) that you can downgrade to */ 4702 assert(target_version == 2); 4703 4704 if (s->refcount_order != 4) { 4705 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 4706 return -ENOTSUP; 4707 } 4708 4709 if (has_data_file(bs)) { 4710 error_setg(errp, "Cannot downgrade an image with a data file"); 4711 return -ENOTSUP; 4712 } 4713 4714 /* clear incompatible features */ 4715 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 4716 ret = qcow2_mark_clean(bs); 4717 if (ret < 0) { 4718 error_setg_errno(errp, -ret, "Failed to make the image clean"); 4719 return ret; 4720 } 4721 } 4722 4723 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 4724 * the first place; if that happens nonetheless, returning -ENOTSUP is the 4725 * best thing to do anyway */ 4726 4727 if (s->incompatible_features) { 4728 error_setg(errp, "Cannot downgrade an image with incompatible features " 4729 "%#" PRIx64 " set", s->incompatible_features); 4730 return -ENOTSUP; 4731 } 4732 4733 /* since we can ignore compatible features, we can set them to 0 as well */ 4734 s->compatible_features = 0; 4735 /* if lazy refcounts have been used, they have already been fixed through 4736 * clearing the dirty flag */ 4737 4738 /* clearing autoclear features is trivial */ 4739 s->autoclear_features = 0; 4740 4741 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 4742 if (ret < 0) { 4743 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 4744 return ret; 4745 } 4746 4747 s->qcow_version = target_version; 4748 ret = qcow2_update_header(bs); 4749 if (ret < 0) { 4750 s->qcow_version = current_version; 4751 error_setg_errno(errp, -ret, "Failed to update the image header"); 4752 return ret; 4753 } 4754 return 0; 4755 } 4756 4757 typedef enum Qcow2AmendOperation { 4758 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 4759 * statically initialized to so that the helper CB can discern the first 4760 * invocation from an operation change */ 4761 QCOW2_NO_OPERATION = 0, 4762 4763 QCOW2_CHANGING_REFCOUNT_ORDER, 4764 QCOW2_DOWNGRADING, 4765 } Qcow2AmendOperation; 4766 4767 typedef struct Qcow2AmendHelperCBInfo { 4768 /* The code coordinating the amend operations should only modify 4769 * these four fields; the rest will be managed by the CB */ 4770 BlockDriverAmendStatusCB *original_status_cb; 4771 void *original_cb_opaque; 4772 4773 Qcow2AmendOperation current_operation; 4774 4775 /* Total number of operations to perform (only set once) */ 4776 int total_operations; 4777 4778 /* The following fields are managed by the CB */ 4779 4780 /* Number of operations completed */ 4781 int operations_completed; 4782 4783 /* Cumulative offset of all completed operations */ 4784 int64_t offset_completed; 4785 4786 Qcow2AmendOperation last_operation; 4787 int64_t last_work_size; 4788 } Qcow2AmendHelperCBInfo; 4789 4790 static void qcow2_amend_helper_cb(BlockDriverState *bs, 4791 int64_t operation_offset, 4792 int64_t operation_work_size, void *opaque) 4793 { 4794 Qcow2AmendHelperCBInfo *info = opaque; 4795 int64_t current_work_size; 4796 int64_t projected_work_size; 4797 4798 if (info->current_operation != info->last_operation) { 4799 if (info->last_operation != QCOW2_NO_OPERATION) { 4800 info->offset_completed += info->last_work_size; 4801 info->operations_completed++; 4802 } 4803 4804 info->last_operation = info->current_operation; 4805 } 4806 4807 assert(info->total_operations > 0); 4808 assert(info->operations_completed < info->total_operations); 4809 4810 info->last_work_size = operation_work_size; 4811 4812 current_work_size = info->offset_completed + operation_work_size; 4813 4814 /* current_work_size is the total work size for (operations_completed + 1) 4815 * operations (which includes this one), so multiply it by the number of 4816 * operations not covered and divide it by the number of operations 4817 * covered to get a projection for the operations not covered */ 4818 projected_work_size = current_work_size * (info->total_operations - 4819 info->operations_completed - 1) 4820 / (info->operations_completed + 1); 4821 4822 info->original_status_cb(bs, info->offset_completed + operation_offset, 4823 current_work_size + projected_work_size, 4824 info->original_cb_opaque); 4825 } 4826 4827 static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 4828 BlockDriverAmendStatusCB *status_cb, 4829 void *cb_opaque, 4830 Error **errp) 4831 { 4832 BDRVQcow2State *s = bs->opaque; 4833 int old_version = s->qcow_version, new_version = old_version; 4834 uint64_t new_size = 0; 4835 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 4836 bool lazy_refcounts = s->use_lazy_refcounts; 4837 bool data_file_raw = data_file_is_raw(bs); 4838 const char *compat = NULL; 4839 uint64_t cluster_size = s->cluster_size; 4840 bool encrypt; 4841 int encformat; 4842 int refcount_bits = s->refcount_bits; 4843 int ret; 4844 QemuOptDesc *desc = opts->list->desc; 4845 Qcow2AmendHelperCBInfo helper_cb_info; 4846 4847 while (desc && desc->name) { 4848 if (!qemu_opt_find(opts, desc->name)) { 4849 /* only change explicitly defined options */ 4850 desc++; 4851 continue; 4852 } 4853 4854 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 4855 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 4856 if (!compat) { 4857 /* preserve default */ 4858 } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) { 4859 new_version = 2; 4860 } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) { 4861 new_version = 3; 4862 } else { 4863 error_setg(errp, "Unknown compatibility level %s", compat); 4864 return -EINVAL; 4865 } 4866 } else if (!strcmp(desc->name, BLOCK_OPT_PREALLOC)) { 4867 error_setg(errp, "Cannot change preallocation mode"); 4868 return -ENOTSUP; 4869 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 4870 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 4871 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 4872 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 4873 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 4874 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 4875 } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) { 4876 encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, 4877 !!s->crypto); 4878 4879 if (encrypt != !!s->crypto) { 4880 error_setg(errp, 4881 "Changing the encryption flag is not supported"); 4882 return -ENOTSUP; 4883 } 4884 } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT_FORMAT)) { 4885 encformat = qcow2_crypt_method_from_format( 4886 qemu_opt_get(opts, BLOCK_OPT_ENCRYPT_FORMAT)); 4887 4888 if (encformat != s->crypt_method_header) { 4889 error_setg(errp, 4890 "Changing the encryption format is not supported"); 4891 return -ENOTSUP; 4892 } 4893 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 4894 error_setg(errp, 4895 "Changing the encryption parameters is not supported"); 4896 return -ENOTSUP; 4897 } else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) { 4898 cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 4899 cluster_size); 4900 if (cluster_size != s->cluster_size) { 4901 error_setg(errp, "Changing the cluster size is not supported"); 4902 return -ENOTSUP; 4903 } 4904 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 4905 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 4906 lazy_refcounts); 4907 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 4908 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 4909 refcount_bits); 4910 4911 if (refcount_bits <= 0 || refcount_bits > 64 || 4912 !is_power_of_2(refcount_bits)) 4913 { 4914 error_setg(errp, "Refcount width must be a power of two and " 4915 "may not exceed 64 bits"); 4916 return -EINVAL; 4917 } 4918 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 4919 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 4920 if (data_file && !has_data_file(bs)) { 4921 error_setg(errp, "data-file can only be set for images that " 4922 "use an external data file"); 4923 return -EINVAL; 4924 } 4925 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 4926 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 4927 data_file_raw); 4928 if (data_file_raw && !data_file_is_raw(bs)) { 4929 error_setg(errp, "data-file-raw cannot be set on existing " 4930 "images"); 4931 return -EINVAL; 4932 } 4933 } else { 4934 /* if this point is reached, this probably means a new option was 4935 * added without having it covered here */ 4936 abort(); 4937 } 4938 4939 desc++; 4940 } 4941 4942 helper_cb_info = (Qcow2AmendHelperCBInfo){ 4943 .original_status_cb = status_cb, 4944 .original_cb_opaque = cb_opaque, 4945 .total_operations = (new_version < old_version) 4946 + (s->refcount_bits != refcount_bits) 4947 }; 4948 4949 /* Upgrade first (some features may require compat=1.1) */ 4950 if (new_version > old_version) { 4951 s->qcow_version = new_version; 4952 ret = qcow2_update_header(bs); 4953 if (ret < 0) { 4954 s->qcow_version = old_version; 4955 error_setg_errno(errp, -ret, "Failed to update the image header"); 4956 return ret; 4957 } 4958 } 4959 4960 if (s->refcount_bits != refcount_bits) { 4961 int refcount_order = ctz32(refcount_bits); 4962 4963 if (new_version < 3 && refcount_bits != 16) { 4964 error_setg(errp, "Refcount widths other than 16 bits require " 4965 "compatibility level 1.1 or above (use compat=1.1 or " 4966 "greater)"); 4967 return -EINVAL; 4968 } 4969 4970 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 4971 ret = qcow2_change_refcount_order(bs, refcount_order, 4972 &qcow2_amend_helper_cb, 4973 &helper_cb_info, errp); 4974 if (ret < 0) { 4975 return ret; 4976 } 4977 } 4978 4979 /* data-file-raw blocks backing files, so clear it first if requested */ 4980 if (data_file_raw) { 4981 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 4982 } else { 4983 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 4984 } 4985 4986 if (data_file) { 4987 g_free(s->image_data_file); 4988 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 4989 } 4990 4991 ret = qcow2_update_header(bs); 4992 if (ret < 0) { 4993 error_setg_errno(errp, -ret, "Failed to update the image header"); 4994 return ret; 4995 } 4996 4997 if (backing_file || backing_format) { 4998 ret = qcow2_change_backing_file(bs, 4999 backing_file ?: s->image_backing_file, 5000 backing_format ?: s->image_backing_format); 5001 if (ret < 0) { 5002 error_setg_errno(errp, -ret, "Failed to change the backing file"); 5003 return ret; 5004 } 5005 } 5006 5007 if (s->use_lazy_refcounts != lazy_refcounts) { 5008 if (lazy_refcounts) { 5009 if (new_version < 3) { 5010 error_setg(errp, "Lazy refcounts only supported with " 5011 "compatibility level 1.1 and above (use compat=1.1 " 5012 "or greater)"); 5013 return -EINVAL; 5014 } 5015 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5016 ret = qcow2_update_header(bs); 5017 if (ret < 0) { 5018 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5019 error_setg_errno(errp, -ret, "Failed to update the image header"); 5020 return ret; 5021 } 5022 s->use_lazy_refcounts = true; 5023 } else { 5024 /* make image clean first */ 5025 ret = qcow2_mark_clean(bs); 5026 if (ret < 0) { 5027 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5028 return ret; 5029 } 5030 /* now disallow lazy refcounts */ 5031 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5032 ret = qcow2_update_header(bs); 5033 if (ret < 0) { 5034 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5035 error_setg_errno(errp, -ret, "Failed to update the image header"); 5036 return ret; 5037 } 5038 s->use_lazy_refcounts = false; 5039 } 5040 } 5041 5042 if (new_size) { 5043 BlockBackend *blk = blk_new(bdrv_get_aio_context(bs), 5044 BLK_PERM_RESIZE, BLK_PERM_ALL); 5045 ret = blk_insert_bs(blk, bs, errp); 5046 if (ret < 0) { 5047 blk_unref(blk); 5048 return ret; 5049 } 5050 5051 ret = blk_truncate(blk, new_size, PREALLOC_MODE_OFF, errp); 5052 blk_unref(blk); 5053 if (ret < 0) { 5054 return ret; 5055 } 5056 } 5057 5058 /* Downgrade last (so unsupported features can be removed before) */ 5059 if (new_version < old_version) { 5060 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5061 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5062 &helper_cb_info, errp); 5063 if (ret < 0) { 5064 return ret; 5065 } 5066 } 5067 5068 return 0; 5069 } 5070 5071 /* 5072 * If offset or size are negative, respectively, they will not be included in 5073 * the BLOCK_IMAGE_CORRUPTED event emitted. 5074 * fatal will be ignored for read-only BDS; corruptions found there will always 5075 * be considered non-fatal. 5076 */ 5077 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5078 int64_t size, const char *message_format, ...) 5079 { 5080 BDRVQcow2State *s = bs->opaque; 5081 const char *node_name; 5082 char *message; 5083 va_list ap; 5084 5085 fatal = fatal && bdrv_is_writable(bs); 5086 5087 if (s->signaled_corruption && 5088 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5089 { 5090 return; 5091 } 5092 5093 va_start(ap, message_format); 5094 message = g_strdup_vprintf(message_format, ap); 5095 va_end(ap); 5096 5097 if (fatal) { 5098 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 5099 "corruption events will be suppressed\n", message); 5100 } else { 5101 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 5102 "corruption events will be suppressed\n", message); 5103 } 5104 5105 node_name = bdrv_get_node_name(bs); 5106 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 5107 *node_name != '\0', node_name, 5108 message, offset >= 0, offset, 5109 size >= 0, size, 5110 fatal); 5111 g_free(message); 5112 5113 if (fatal) { 5114 qcow2_mark_corrupt(bs); 5115 bs->drv = NULL; /* make BDS unusable */ 5116 } 5117 5118 s->signaled_corruption = true; 5119 } 5120 5121 static QemuOptsList qcow2_create_opts = { 5122 .name = "qcow2-create-opts", 5123 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 5124 .desc = { 5125 { 5126 .name = BLOCK_OPT_SIZE, 5127 .type = QEMU_OPT_SIZE, 5128 .help = "Virtual disk size" 5129 }, 5130 { 5131 .name = BLOCK_OPT_COMPAT_LEVEL, 5132 .type = QEMU_OPT_STRING, 5133 .help = "Compatibility level (v2 [0.10] or v3 [1.1])" 5134 }, 5135 { 5136 .name = BLOCK_OPT_BACKING_FILE, 5137 .type = QEMU_OPT_STRING, 5138 .help = "File name of a base image" 5139 }, 5140 { 5141 .name = BLOCK_OPT_BACKING_FMT, 5142 .type = QEMU_OPT_STRING, 5143 .help = "Image format of the base image" 5144 }, 5145 { 5146 .name = BLOCK_OPT_DATA_FILE, 5147 .type = QEMU_OPT_STRING, 5148 .help = "File name of an external data file" 5149 }, 5150 { 5151 .name = BLOCK_OPT_DATA_FILE_RAW, 5152 .type = QEMU_OPT_BOOL, 5153 .help = "The external data file must stay valid as a raw image" 5154 }, 5155 { 5156 .name = BLOCK_OPT_ENCRYPT, 5157 .type = QEMU_OPT_BOOL, 5158 .help = "Encrypt the image with format 'aes'. (Deprecated " 5159 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", 5160 }, 5161 { 5162 .name = BLOCK_OPT_ENCRYPT_FORMAT, 5163 .type = QEMU_OPT_STRING, 5164 .help = "Encrypt the image, format choices: 'aes', 'luks'", 5165 }, 5166 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 5167 "ID of secret providing qcow AES key or LUKS passphrase"), 5168 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), 5169 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), 5170 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), 5171 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), 5172 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), 5173 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 5174 { 5175 .name = BLOCK_OPT_CLUSTER_SIZE, 5176 .type = QEMU_OPT_SIZE, 5177 .help = "qcow2 cluster size", 5178 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) 5179 }, 5180 { 5181 .name = BLOCK_OPT_PREALLOC, 5182 .type = QEMU_OPT_STRING, 5183 .help = "Preallocation mode (allowed values: off, metadata, " 5184 "falloc, full)" 5185 }, 5186 { 5187 .name = BLOCK_OPT_LAZY_REFCOUNTS, 5188 .type = QEMU_OPT_BOOL, 5189 .help = "Postpone refcount updates", 5190 .def_value_str = "off" 5191 }, 5192 { 5193 .name = BLOCK_OPT_REFCOUNT_BITS, 5194 .type = QEMU_OPT_NUMBER, 5195 .help = "Width of a reference count entry in bits", 5196 .def_value_str = "16" 5197 }, 5198 { /* end of list */ } 5199 } 5200 }; 5201 5202 static const char *const qcow2_strong_runtime_opts[] = { 5203 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 5204 5205 NULL 5206 }; 5207 5208 BlockDriver bdrv_qcow2 = { 5209 .format_name = "qcow2", 5210 .instance_size = sizeof(BDRVQcow2State), 5211 .bdrv_probe = qcow2_probe, 5212 .bdrv_open = qcow2_open, 5213 .bdrv_close = qcow2_close, 5214 .bdrv_reopen_prepare = qcow2_reopen_prepare, 5215 .bdrv_reopen_commit = qcow2_reopen_commit, 5216 .bdrv_reopen_abort = qcow2_reopen_abort, 5217 .bdrv_join_options = qcow2_join_options, 5218 .bdrv_child_perm = bdrv_format_default_perms, 5219 .bdrv_co_create_opts = qcow2_co_create_opts, 5220 .bdrv_co_create = qcow2_co_create, 5221 .bdrv_has_zero_init = qcow2_has_zero_init, 5222 .bdrv_has_zero_init_truncate = bdrv_has_zero_init_1, 5223 .bdrv_co_block_status = qcow2_co_block_status, 5224 5225 .bdrv_co_preadv_part = qcow2_co_preadv_part, 5226 .bdrv_co_pwritev_part = qcow2_co_pwritev_part, 5227 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 5228 5229 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 5230 .bdrv_co_pdiscard = qcow2_co_pdiscard, 5231 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 5232 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 5233 .bdrv_co_truncate = qcow2_co_truncate, 5234 .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part, 5235 .bdrv_make_empty = qcow2_make_empty, 5236 5237 .bdrv_snapshot_create = qcow2_snapshot_create, 5238 .bdrv_snapshot_goto = qcow2_snapshot_goto, 5239 .bdrv_snapshot_delete = qcow2_snapshot_delete, 5240 .bdrv_snapshot_list = qcow2_snapshot_list, 5241 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 5242 .bdrv_measure = qcow2_measure, 5243 .bdrv_get_info = qcow2_get_info, 5244 .bdrv_get_specific_info = qcow2_get_specific_info, 5245 5246 .bdrv_save_vmstate = qcow2_save_vmstate, 5247 .bdrv_load_vmstate = qcow2_load_vmstate, 5248 5249 .supports_backing = true, 5250 .bdrv_change_backing_file = qcow2_change_backing_file, 5251 5252 .bdrv_refresh_limits = qcow2_refresh_limits, 5253 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 5254 .bdrv_inactivate = qcow2_inactivate, 5255 5256 .create_opts = &qcow2_create_opts, 5257 .strong_runtime_opts = qcow2_strong_runtime_opts, 5258 .mutable_opts = mutable_opts, 5259 .bdrv_co_check = qcow2_co_check, 5260 .bdrv_amend_options = qcow2_amend_options, 5261 5262 .bdrv_detach_aio_context = qcow2_detach_aio_context, 5263 .bdrv_attach_aio_context = qcow2_attach_aio_context, 5264 5265 .bdrv_reopen_bitmaps_rw = qcow2_reopen_bitmaps_rw, 5266 .bdrv_can_store_new_dirty_bitmap = qcow2_can_store_new_dirty_bitmap, 5267 .bdrv_remove_persistent_dirty_bitmap = qcow2_remove_persistent_dirty_bitmap, 5268 }; 5269 5270 static void bdrv_qcow2_init(void) 5271 { 5272 bdrv_register(&bdrv_qcow2); 5273 } 5274 5275 block_init(bdrv_qcow2_init); 5276