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 #define ZLIB_CONST 28 #include <zlib.h> 29 30 #include "block/block_int.h" 31 #include "block/qdict.h" 32 #include "sysemu/block-backend.h" 33 #include "qemu/module.h" 34 #include "qcow2.h" 35 #include "qemu/error-report.h" 36 #include "qapi/error.h" 37 #include "qapi/qapi-events-block-core.h" 38 #include "qapi/qmp/qdict.h" 39 #include "qapi/qmp/qstring.h" 40 #include "trace.h" 41 #include "qemu/option_int.h" 42 #include "qemu/cutils.h" 43 #include "qemu/bswap.h" 44 #include "qapi/qobject-input-visitor.h" 45 #include "qapi/qapi-visit-block-core.h" 46 #include "crypto.h" 47 #include "block/thread-pool.h" 48 49 /* 50 Differences with QCOW: 51 52 - Support for multiple incremental snapshots. 53 - Memory management by reference counts. 54 - Clusters which have a reference count of one have the bit 55 QCOW_OFLAG_COPIED to optimize write performance. 56 - Size of compressed clusters is stored in sectors to reduce bit usage 57 in the cluster offsets. 58 - Support for storing additional data (such as the VM state) in the 59 snapshots. 60 - If a backing store is used, the cluster size is not constrained 61 (could be backported to QCOW). 62 - L2 tables have always a size of one cluster. 63 */ 64 65 66 typedef struct { 67 uint32_t magic; 68 uint32_t len; 69 } QEMU_PACKED QCowExtension; 70 71 #define QCOW2_EXT_MAGIC_END 0 72 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA 73 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 74 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 75 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 76 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 77 78 static int coroutine_fn 79 qcow2_co_preadv_compressed(BlockDriverState *bs, 80 uint64_t file_cluster_offset, 81 uint64_t offset, 82 uint64_t bytes, 83 QEMUIOVector *qiov); 84 85 static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) 86 { 87 const QCowHeader *cow_header = (const void *)buf; 88 89 if (buf_size >= sizeof(QCowHeader) && 90 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 91 be32_to_cpu(cow_header->version) >= 2) 92 return 100; 93 else 94 return 0; 95 } 96 97 98 static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, 99 uint8_t *buf, size_t buflen, 100 void *opaque, Error **errp) 101 { 102 BlockDriverState *bs = opaque; 103 BDRVQcow2State *s = bs->opaque; 104 ssize_t ret; 105 106 if ((offset + buflen) > s->crypto_header.length) { 107 error_setg(errp, "Request for data outside of extension header"); 108 return -1; 109 } 110 111 ret = bdrv_pread(bs->file, 112 s->crypto_header.offset + offset, buf, buflen); 113 if (ret < 0) { 114 error_setg_errno(errp, -ret, "Could not read encryption header"); 115 return -1; 116 } 117 return ret; 118 } 119 120 121 static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, 122 void *opaque, Error **errp) 123 { 124 BlockDriverState *bs = opaque; 125 BDRVQcow2State *s = bs->opaque; 126 int64_t ret; 127 int64_t clusterlen; 128 129 ret = qcow2_alloc_clusters(bs, headerlen); 130 if (ret < 0) { 131 error_setg_errno(errp, -ret, 132 "Cannot allocate cluster for LUKS header size %zu", 133 headerlen); 134 return -1; 135 } 136 137 s->crypto_header.length = headerlen; 138 s->crypto_header.offset = ret; 139 140 /* Zero fill remaining space in cluster so it has predictable 141 * content in case of future spec changes */ 142 clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; 143 assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); 144 ret = bdrv_pwrite_zeroes(bs->file, 145 ret + headerlen, 146 clusterlen - headerlen, 0); 147 if (ret < 0) { 148 error_setg_errno(errp, -ret, "Could not zero fill encryption header"); 149 return -1; 150 } 151 152 return ret; 153 } 154 155 156 static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, 157 const uint8_t *buf, size_t buflen, 158 void *opaque, Error **errp) 159 { 160 BlockDriverState *bs = opaque; 161 BDRVQcow2State *s = bs->opaque; 162 ssize_t ret; 163 164 if ((offset + buflen) > s->crypto_header.length) { 165 error_setg(errp, "Request for data outside of extension header"); 166 return -1; 167 } 168 169 ret = bdrv_pwrite(bs->file, 170 s->crypto_header.offset + offset, buf, buflen); 171 if (ret < 0) { 172 error_setg_errno(errp, -ret, "Could not read encryption header"); 173 return -1; 174 } 175 return ret; 176 } 177 178 179 /* 180 * read qcow2 extension and fill bs 181 * start reading from start_offset 182 * finish reading upon magic of value 0 or when end_offset reached 183 * unknown magic is skipped (future extension this version knows nothing about) 184 * return 0 upon success, non-0 otherwise 185 */ 186 static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, 187 uint64_t end_offset, void **p_feature_table, 188 int flags, bool *need_update_header, 189 Error **errp) 190 { 191 BDRVQcow2State *s = bs->opaque; 192 QCowExtension ext; 193 uint64_t offset; 194 int ret; 195 Qcow2BitmapHeaderExt bitmaps_ext; 196 197 if (need_update_header != NULL) { 198 *need_update_header = false; 199 } 200 201 #ifdef DEBUG_EXT 202 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); 203 #endif 204 offset = start_offset; 205 while (offset < end_offset) { 206 207 #ifdef DEBUG_EXT 208 /* Sanity check */ 209 if (offset > s->cluster_size) 210 printf("qcow2_read_extension: suspicious offset %lu\n", offset); 211 212 printf("attempting to read extended header in offset %lu\n", offset); 213 #endif 214 215 ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext)); 216 if (ret < 0) { 217 error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " 218 "pread fail from offset %" PRIu64, offset); 219 return 1; 220 } 221 ext.magic = be32_to_cpu(ext.magic); 222 ext.len = be32_to_cpu(ext.len); 223 offset += sizeof(ext); 224 #ifdef DEBUG_EXT 225 printf("ext.magic = 0x%x\n", ext.magic); 226 #endif 227 if (offset > end_offset || ext.len > end_offset - offset) { 228 error_setg(errp, "Header extension too large"); 229 return -EINVAL; 230 } 231 232 switch (ext.magic) { 233 case QCOW2_EXT_MAGIC_END: 234 return 0; 235 236 case QCOW2_EXT_MAGIC_BACKING_FORMAT: 237 if (ext.len >= sizeof(bs->backing_format)) { 238 error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 239 " too large (>=%zu)", ext.len, 240 sizeof(bs->backing_format)); 241 return 2; 242 } 243 ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len); 244 if (ret < 0) { 245 error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " 246 "Could not read format name"); 247 return 3; 248 } 249 bs->backing_format[ext.len] = '\0'; 250 s->image_backing_format = g_strdup(bs->backing_format); 251 #ifdef DEBUG_EXT 252 printf("Qcow2: Got format extension %s\n", bs->backing_format); 253 #endif 254 break; 255 256 case QCOW2_EXT_MAGIC_FEATURE_TABLE: 257 if (p_feature_table != NULL) { 258 void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); 259 ret = bdrv_pread(bs->file, offset , feature_table, ext.len); 260 if (ret < 0) { 261 error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " 262 "Could not read table"); 263 return ret; 264 } 265 266 *p_feature_table = feature_table; 267 } 268 break; 269 270 case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { 271 unsigned int cflags = 0; 272 if (s->crypt_method_header != QCOW_CRYPT_LUKS) { 273 error_setg(errp, "CRYPTO header extension only " 274 "expected with LUKS encryption method"); 275 return -EINVAL; 276 } 277 if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { 278 error_setg(errp, "CRYPTO header extension size %u, " 279 "but expected size %zu", ext.len, 280 sizeof(Qcow2CryptoHeaderExtension)); 281 return -EINVAL; 282 } 283 284 ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len); 285 if (ret < 0) { 286 error_setg_errno(errp, -ret, 287 "Unable to read CRYPTO header extension"); 288 return ret; 289 } 290 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 291 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 292 293 if ((s->crypto_header.offset % s->cluster_size) != 0) { 294 error_setg(errp, "Encryption header offset '%" PRIu64 "' is " 295 "not a multiple of cluster size '%u'", 296 s->crypto_header.offset, s->cluster_size); 297 return -EINVAL; 298 } 299 300 if (flags & BDRV_O_NO_IO) { 301 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 302 } 303 s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", 304 qcow2_crypto_hdr_read_func, 305 bs, cflags, 1, errp); 306 if (!s->crypto) { 307 return -EINVAL; 308 } 309 } break; 310 311 case QCOW2_EXT_MAGIC_BITMAPS: 312 if (ext.len != sizeof(bitmaps_ext)) { 313 error_setg_errno(errp, -ret, "bitmaps_ext: " 314 "Invalid extension length"); 315 return -EINVAL; 316 } 317 318 if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { 319 if (s->qcow_version < 3) { 320 /* Let's be a bit more specific */ 321 warn_report("This qcow2 v2 image contains bitmaps, but " 322 "they may have been modified by a program " 323 "without persistent bitmap support; so now " 324 "they must all be considered inconsistent"); 325 } else { 326 warn_report("a program lacking bitmap support " 327 "modified this file, so all bitmaps are now " 328 "considered inconsistent"); 329 } 330 error_printf("Some clusters may be leaked, " 331 "run 'qemu-img check -r' on the image " 332 "file to fix."); 333 if (need_update_header != NULL) { 334 /* Updating is needed to drop invalid bitmap extension. */ 335 *need_update_header = true; 336 } 337 break; 338 } 339 340 ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len); 341 if (ret < 0) { 342 error_setg_errno(errp, -ret, "bitmaps_ext: " 343 "Could not read ext header"); 344 return ret; 345 } 346 347 if (bitmaps_ext.reserved32 != 0) { 348 error_setg_errno(errp, -ret, "bitmaps_ext: " 349 "Reserved field is not zero"); 350 return -EINVAL; 351 } 352 353 bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); 354 bitmaps_ext.bitmap_directory_size = 355 be64_to_cpu(bitmaps_ext.bitmap_directory_size); 356 bitmaps_ext.bitmap_directory_offset = 357 be64_to_cpu(bitmaps_ext.bitmap_directory_offset); 358 359 if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { 360 error_setg(errp, 361 "bitmaps_ext: Image has %" PRIu32 " bitmaps, " 362 "exceeding the QEMU supported maximum of %d", 363 bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); 364 return -EINVAL; 365 } 366 367 if (bitmaps_ext.nb_bitmaps == 0) { 368 error_setg(errp, "found bitmaps extension with zero bitmaps"); 369 return -EINVAL; 370 } 371 372 if (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) { 373 error_setg(errp, "bitmaps_ext: " 374 "invalid bitmap directory offset"); 375 return -EINVAL; 376 } 377 378 if (bitmaps_ext.bitmap_directory_size > 379 QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { 380 error_setg(errp, "bitmaps_ext: " 381 "bitmap directory size (%" PRIu64 ") exceeds " 382 "the maximum supported size (%d)", 383 bitmaps_ext.bitmap_directory_size, 384 QCOW2_MAX_BITMAP_DIRECTORY_SIZE); 385 return -EINVAL; 386 } 387 388 s->nb_bitmaps = bitmaps_ext.nb_bitmaps; 389 s->bitmap_directory_offset = 390 bitmaps_ext.bitmap_directory_offset; 391 s->bitmap_directory_size = 392 bitmaps_ext.bitmap_directory_size; 393 394 #ifdef DEBUG_EXT 395 printf("Qcow2: Got bitmaps extension: " 396 "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", 397 s->bitmap_directory_offset, s->nb_bitmaps); 398 #endif 399 break; 400 401 case QCOW2_EXT_MAGIC_DATA_FILE: 402 { 403 s->image_data_file = g_malloc0(ext.len + 1); 404 ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len); 405 if (ret < 0) { 406 error_setg_errno(errp, -ret, 407 "ERROR: Could not read data file name"); 408 return ret; 409 } 410 #ifdef DEBUG_EXT 411 printf("Qcow2: Got external data file %s\n", s->image_data_file); 412 #endif 413 break; 414 } 415 416 default: 417 /* unknown magic - save it in case we need to rewrite the header */ 418 /* If you add a new feature, make sure to also update the fast 419 * path of qcow2_make_empty() to deal with it. */ 420 { 421 Qcow2UnknownHeaderExtension *uext; 422 423 uext = g_malloc0(sizeof(*uext) + ext.len); 424 uext->magic = ext.magic; 425 uext->len = ext.len; 426 QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); 427 428 ret = bdrv_pread(bs->file, offset , uext->data, uext->len); 429 if (ret < 0) { 430 error_setg_errno(errp, -ret, "ERROR: unknown extension: " 431 "Could not read data"); 432 return ret; 433 } 434 } 435 break; 436 } 437 438 offset += ((ext.len + 7) & ~7); 439 } 440 441 return 0; 442 } 443 444 static void cleanup_unknown_header_ext(BlockDriverState *bs) 445 { 446 BDRVQcow2State *s = bs->opaque; 447 Qcow2UnknownHeaderExtension *uext, *next; 448 449 QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { 450 QLIST_REMOVE(uext, next); 451 g_free(uext); 452 } 453 } 454 455 static void report_unsupported_feature(Error **errp, Qcow2Feature *table, 456 uint64_t mask) 457 { 458 char *features = g_strdup(""); 459 char *old; 460 461 while (table && table->name[0] != '\0') { 462 if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { 463 if (mask & (1ULL << table->bit)) { 464 old = features; 465 features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", 466 table->name); 467 g_free(old); 468 mask &= ~(1ULL << table->bit); 469 } 470 } 471 table++; 472 } 473 474 if (mask) { 475 old = features; 476 features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, 477 old, *old ? ", " : "", mask); 478 g_free(old); 479 } 480 481 error_setg(errp, "Unsupported qcow2 feature(s): %s", features); 482 g_free(features); 483 } 484 485 /* 486 * Sets the dirty bit and flushes afterwards if necessary. 487 * 488 * The incompatible_features bit is only set if the image file header was 489 * updated successfully. Therefore it is not required to check the return 490 * value of this function. 491 */ 492 int qcow2_mark_dirty(BlockDriverState *bs) 493 { 494 BDRVQcow2State *s = bs->opaque; 495 uint64_t val; 496 int ret; 497 498 assert(s->qcow_version >= 3); 499 500 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 501 return 0; /* already dirty */ 502 } 503 504 val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); 505 ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), 506 &val, sizeof(val)); 507 if (ret < 0) { 508 return ret; 509 } 510 ret = bdrv_flush(bs->file->bs); 511 if (ret < 0) { 512 return ret; 513 } 514 515 /* Only treat image as dirty if the header was updated successfully */ 516 s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; 517 return 0; 518 } 519 520 /* 521 * Clears the dirty bit and flushes before if necessary. Only call this 522 * function when there are no pending requests, it does not guard against 523 * concurrent requests dirtying the image. 524 */ 525 static int qcow2_mark_clean(BlockDriverState *bs) 526 { 527 BDRVQcow2State *s = bs->opaque; 528 529 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 530 int ret; 531 532 s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; 533 534 ret = qcow2_flush_caches(bs); 535 if (ret < 0) { 536 return ret; 537 } 538 539 return qcow2_update_header(bs); 540 } 541 return 0; 542 } 543 544 /* 545 * Marks the image as corrupt. 546 */ 547 int qcow2_mark_corrupt(BlockDriverState *bs) 548 { 549 BDRVQcow2State *s = bs->opaque; 550 551 s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; 552 return qcow2_update_header(bs); 553 } 554 555 /* 556 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes 557 * before if necessary. 558 */ 559 int qcow2_mark_consistent(BlockDriverState *bs) 560 { 561 BDRVQcow2State *s = bs->opaque; 562 563 if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { 564 int ret = qcow2_flush_caches(bs); 565 if (ret < 0) { 566 return ret; 567 } 568 569 s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; 570 return qcow2_update_header(bs); 571 } 572 return 0; 573 } 574 575 static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs, 576 BdrvCheckResult *result, 577 BdrvCheckMode fix) 578 { 579 int ret = qcow2_check_refcounts(bs, result, fix); 580 if (ret < 0) { 581 return ret; 582 } 583 584 if (fix && result->check_errors == 0 && result->corruptions == 0) { 585 ret = qcow2_mark_clean(bs); 586 if (ret < 0) { 587 return ret; 588 } 589 return qcow2_mark_consistent(bs); 590 } 591 return ret; 592 } 593 594 static int coroutine_fn qcow2_co_check(BlockDriverState *bs, 595 BdrvCheckResult *result, 596 BdrvCheckMode fix) 597 { 598 BDRVQcow2State *s = bs->opaque; 599 int ret; 600 601 qemu_co_mutex_lock(&s->lock); 602 ret = qcow2_co_check_locked(bs, result, fix); 603 qemu_co_mutex_unlock(&s->lock); 604 return ret; 605 } 606 607 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 608 uint64_t entries, size_t entry_len, 609 int64_t max_size_bytes, const char *table_name, 610 Error **errp) 611 { 612 BDRVQcow2State *s = bs->opaque; 613 614 if (entries > max_size_bytes / entry_len) { 615 error_setg(errp, "%s too large", table_name); 616 return -EFBIG; 617 } 618 619 /* Use signed INT64_MAX as the maximum even for uint64_t header fields, 620 * because values will be passed to qemu functions taking int64_t. */ 621 if ((INT64_MAX - entries * entry_len < offset) || 622 (offset_into_cluster(s, offset) != 0)) { 623 error_setg(errp, "%s offset invalid", table_name); 624 return -EINVAL; 625 } 626 627 return 0; 628 } 629 630 static const char *const mutable_opts[] = { 631 QCOW2_OPT_LAZY_REFCOUNTS, 632 QCOW2_OPT_DISCARD_REQUEST, 633 QCOW2_OPT_DISCARD_SNAPSHOT, 634 QCOW2_OPT_DISCARD_OTHER, 635 QCOW2_OPT_OVERLAP, 636 QCOW2_OPT_OVERLAP_TEMPLATE, 637 QCOW2_OPT_OVERLAP_MAIN_HEADER, 638 QCOW2_OPT_OVERLAP_ACTIVE_L1, 639 QCOW2_OPT_OVERLAP_ACTIVE_L2, 640 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 641 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 642 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 643 QCOW2_OPT_OVERLAP_INACTIVE_L1, 644 QCOW2_OPT_OVERLAP_INACTIVE_L2, 645 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 646 QCOW2_OPT_CACHE_SIZE, 647 QCOW2_OPT_L2_CACHE_SIZE, 648 QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 649 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 650 QCOW2_OPT_CACHE_CLEAN_INTERVAL, 651 NULL 652 }; 653 654 static QemuOptsList qcow2_runtime_opts = { 655 .name = "qcow2", 656 .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), 657 .desc = { 658 { 659 .name = QCOW2_OPT_LAZY_REFCOUNTS, 660 .type = QEMU_OPT_BOOL, 661 .help = "Postpone refcount updates", 662 }, 663 { 664 .name = QCOW2_OPT_DISCARD_REQUEST, 665 .type = QEMU_OPT_BOOL, 666 .help = "Pass guest discard requests to the layer below", 667 }, 668 { 669 .name = QCOW2_OPT_DISCARD_SNAPSHOT, 670 .type = QEMU_OPT_BOOL, 671 .help = "Generate discard requests when snapshot related space " 672 "is freed", 673 }, 674 { 675 .name = QCOW2_OPT_DISCARD_OTHER, 676 .type = QEMU_OPT_BOOL, 677 .help = "Generate discard requests when other clusters are freed", 678 }, 679 { 680 .name = QCOW2_OPT_OVERLAP, 681 .type = QEMU_OPT_STRING, 682 .help = "Selects which overlap checks to perform from a range of " 683 "templates (none, constant, cached, all)", 684 }, 685 { 686 .name = QCOW2_OPT_OVERLAP_TEMPLATE, 687 .type = QEMU_OPT_STRING, 688 .help = "Selects which overlap checks to perform from a range of " 689 "templates (none, constant, cached, all)", 690 }, 691 { 692 .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, 693 .type = QEMU_OPT_BOOL, 694 .help = "Check for unintended writes into the main qcow2 header", 695 }, 696 { 697 .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, 698 .type = QEMU_OPT_BOOL, 699 .help = "Check for unintended writes into the active L1 table", 700 }, 701 { 702 .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, 703 .type = QEMU_OPT_BOOL, 704 .help = "Check for unintended writes into an active L2 table", 705 }, 706 { 707 .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 708 .type = QEMU_OPT_BOOL, 709 .help = "Check for unintended writes into the refcount table", 710 }, 711 { 712 .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 713 .type = QEMU_OPT_BOOL, 714 .help = "Check for unintended writes into a refcount block", 715 }, 716 { 717 .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 718 .type = QEMU_OPT_BOOL, 719 .help = "Check for unintended writes into the snapshot table", 720 }, 721 { 722 .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, 723 .type = QEMU_OPT_BOOL, 724 .help = "Check for unintended writes into an inactive L1 table", 725 }, 726 { 727 .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, 728 .type = QEMU_OPT_BOOL, 729 .help = "Check for unintended writes into an inactive L2 table", 730 }, 731 { 732 .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 733 .type = QEMU_OPT_BOOL, 734 .help = "Check for unintended writes into the bitmap directory", 735 }, 736 { 737 .name = QCOW2_OPT_CACHE_SIZE, 738 .type = QEMU_OPT_SIZE, 739 .help = "Maximum combined metadata (L2 tables and refcount blocks) " 740 "cache size", 741 }, 742 { 743 .name = QCOW2_OPT_L2_CACHE_SIZE, 744 .type = QEMU_OPT_SIZE, 745 .help = "Maximum L2 table cache size", 746 }, 747 { 748 .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, 749 .type = QEMU_OPT_SIZE, 750 .help = "Size of each entry in the L2 cache", 751 }, 752 { 753 .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, 754 .type = QEMU_OPT_SIZE, 755 .help = "Maximum refcount block cache size", 756 }, 757 { 758 .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, 759 .type = QEMU_OPT_NUMBER, 760 .help = "Clean unused cache entries after this time (in seconds)", 761 }, 762 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 763 "ID of secret providing qcow2 AES key or LUKS passphrase"), 764 { /* end of list */ } 765 }, 766 }; 767 768 static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { 769 [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, 770 [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, 771 [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, 772 [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, 773 [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, 774 [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, 775 [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, 776 [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, 777 [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, 778 }; 779 780 static void cache_clean_timer_cb(void *opaque) 781 { 782 BlockDriverState *bs = opaque; 783 BDRVQcow2State *s = bs->opaque; 784 qcow2_cache_clean_unused(s->l2_table_cache); 785 qcow2_cache_clean_unused(s->refcount_block_cache); 786 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 787 (int64_t) s->cache_clean_interval * 1000); 788 } 789 790 static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) 791 { 792 BDRVQcow2State *s = bs->opaque; 793 if (s->cache_clean_interval > 0) { 794 s->cache_clean_timer = aio_timer_new(context, QEMU_CLOCK_VIRTUAL, 795 SCALE_MS, cache_clean_timer_cb, 796 bs); 797 timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 798 (int64_t) s->cache_clean_interval * 1000); 799 } 800 } 801 802 static void cache_clean_timer_del(BlockDriverState *bs) 803 { 804 BDRVQcow2State *s = bs->opaque; 805 if (s->cache_clean_timer) { 806 timer_del(s->cache_clean_timer); 807 timer_free(s->cache_clean_timer); 808 s->cache_clean_timer = NULL; 809 } 810 } 811 812 static void qcow2_detach_aio_context(BlockDriverState *bs) 813 { 814 cache_clean_timer_del(bs); 815 } 816 817 static void qcow2_attach_aio_context(BlockDriverState *bs, 818 AioContext *new_context) 819 { 820 cache_clean_timer_init(bs, new_context); 821 } 822 823 static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, 824 uint64_t *l2_cache_size, 825 uint64_t *l2_cache_entry_size, 826 uint64_t *refcount_cache_size, Error **errp) 827 { 828 BDRVQcow2State *s = bs->opaque; 829 uint64_t combined_cache_size, l2_cache_max_setting; 830 bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; 831 bool l2_cache_entry_size_set; 832 int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; 833 uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; 834 uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8); 835 836 combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); 837 l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); 838 refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 839 l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); 840 841 combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); 842 l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 843 DEFAULT_L2_CACHE_MAX_SIZE); 844 *refcount_cache_size = qemu_opt_get_size(opts, 845 QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); 846 847 *l2_cache_entry_size = qemu_opt_get_size( 848 opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); 849 850 *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); 851 852 if (combined_cache_size_set) { 853 if (l2_cache_size_set && refcount_cache_size_set) { 854 error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE 855 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " 856 "at the same time"); 857 return; 858 } else if (l2_cache_size_set && 859 (l2_cache_max_setting > combined_cache_size)) { 860 error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " 861 QCOW2_OPT_CACHE_SIZE); 862 return; 863 } else if (*refcount_cache_size > combined_cache_size) { 864 error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " 865 QCOW2_OPT_CACHE_SIZE); 866 return; 867 } 868 869 if (l2_cache_size_set) { 870 *refcount_cache_size = combined_cache_size - *l2_cache_size; 871 } else if (refcount_cache_size_set) { 872 *l2_cache_size = combined_cache_size - *refcount_cache_size; 873 } else { 874 /* Assign as much memory as possible to the L2 cache, and 875 * use the remainder for the refcount cache */ 876 if (combined_cache_size >= max_l2_cache + min_refcount_cache) { 877 *l2_cache_size = max_l2_cache; 878 *refcount_cache_size = combined_cache_size - *l2_cache_size; 879 } else { 880 *refcount_cache_size = 881 MIN(combined_cache_size, min_refcount_cache); 882 *l2_cache_size = combined_cache_size - *refcount_cache_size; 883 } 884 } 885 } 886 887 /* 888 * If the L2 cache is not enough to cover the whole disk then 889 * default to 4KB entries. Smaller entries reduce the cost of 890 * loads and evictions and increase I/O performance. 891 */ 892 if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { 893 *l2_cache_entry_size = MIN(s->cluster_size, 4096); 894 } 895 896 /* l2_cache_size and refcount_cache_size are ensured to have at least 897 * their minimum values in qcow2_update_options_prepare() */ 898 899 if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || 900 *l2_cache_entry_size > s->cluster_size || 901 !is_power_of_2(*l2_cache_entry_size)) { 902 error_setg(errp, "L2 cache entry size must be a power of two " 903 "between %d and the cluster size (%d)", 904 1 << MIN_CLUSTER_BITS, s->cluster_size); 905 return; 906 } 907 } 908 909 typedef struct Qcow2ReopenState { 910 Qcow2Cache *l2_table_cache; 911 Qcow2Cache *refcount_block_cache; 912 int l2_slice_size; /* Number of entries in a slice of the L2 table */ 913 bool use_lazy_refcounts; 914 int overlap_check; 915 bool discard_passthrough[QCOW2_DISCARD_MAX]; 916 uint64_t cache_clean_interval; 917 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 918 } Qcow2ReopenState; 919 920 static int qcow2_update_options_prepare(BlockDriverState *bs, 921 Qcow2ReopenState *r, 922 QDict *options, int flags, 923 Error **errp) 924 { 925 BDRVQcow2State *s = bs->opaque; 926 QemuOpts *opts = NULL; 927 const char *opt_overlap_check, *opt_overlap_check_template; 928 int overlap_check_template = 0; 929 uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; 930 int i; 931 const char *encryptfmt; 932 QDict *encryptopts = NULL; 933 Error *local_err = NULL; 934 int ret; 935 936 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 937 encryptfmt = qdict_get_try_str(encryptopts, "format"); 938 939 opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); 940 qemu_opts_absorb_qdict(opts, options, &local_err); 941 if (local_err) { 942 error_propagate(errp, local_err); 943 ret = -EINVAL; 944 goto fail; 945 } 946 947 /* get L2 table/refcount block cache size from command line options */ 948 read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, 949 &refcount_cache_size, &local_err); 950 if (local_err) { 951 error_propagate(errp, local_err); 952 ret = -EINVAL; 953 goto fail; 954 } 955 956 l2_cache_size /= l2_cache_entry_size; 957 if (l2_cache_size < MIN_L2_CACHE_SIZE) { 958 l2_cache_size = MIN_L2_CACHE_SIZE; 959 } 960 if (l2_cache_size > INT_MAX) { 961 error_setg(errp, "L2 cache size too big"); 962 ret = -EINVAL; 963 goto fail; 964 } 965 966 refcount_cache_size /= s->cluster_size; 967 if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { 968 refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; 969 } 970 if (refcount_cache_size > INT_MAX) { 971 error_setg(errp, "Refcount cache size too big"); 972 ret = -EINVAL; 973 goto fail; 974 } 975 976 /* alloc new L2 table/refcount block cache, flush old one */ 977 if (s->l2_table_cache) { 978 ret = qcow2_cache_flush(bs, s->l2_table_cache); 979 if (ret) { 980 error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); 981 goto fail; 982 } 983 } 984 985 if (s->refcount_block_cache) { 986 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 987 if (ret) { 988 error_setg_errno(errp, -ret, 989 "Failed to flush the refcount block cache"); 990 goto fail; 991 } 992 } 993 994 r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t); 995 r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, 996 l2_cache_entry_size); 997 r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, 998 s->cluster_size); 999 if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { 1000 error_setg(errp, "Could not allocate metadata caches"); 1001 ret = -ENOMEM; 1002 goto fail; 1003 } 1004 1005 /* New interval for cache cleanup timer */ 1006 r->cache_clean_interval = 1007 qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, 1008 DEFAULT_CACHE_CLEAN_INTERVAL); 1009 #ifndef CONFIG_LINUX 1010 if (r->cache_clean_interval != 0) { 1011 error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL 1012 " not supported on this host"); 1013 ret = -EINVAL; 1014 goto fail; 1015 } 1016 #endif 1017 if (r->cache_clean_interval > UINT_MAX) { 1018 error_setg(errp, "Cache clean interval too big"); 1019 ret = -EINVAL; 1020 goto fail; 1021 } 1022 1023 /* lazy-refcounts; flush if going from enabled to disabled */ 1024 r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, 1025 (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); 1026 if (r->use_lazy_refcounts && s->qcow_version < 3) { 1027 error_setg(errp, "Lazy refcounts require a qcow2 image with at least " 1028 "qemu 1.1 compatibility level"); 1029 ret = -EINVAL; 1030 goto fail; 1031 } 1032 1033 if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { 1034 ret = qcow2_mark_clean(bs); 1035 if (ret < 0) { 1036 error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); 1037 goto fail; 1038 } 1039 } 1040 1041 /* Overlap check options */ 1042 opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); 1043 opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); 1044 if (opt_overlap_check_template && opt_overlap_check && 1045 strcmp(opt_overlap_check_template, opt_overlap_check)) 1046 { 1047 error_setg(errp, "Conflicting values for qcow2 options '" 1048 QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE 1049 "' ('%s')", opt_overlap_check, opt_overlap_check_template); 1050 ret = -EINVAL; 1051 goto fail; 1052 } 1053 if (!opt_overlap_check) { 1054 opt_overlap_check = opt_overlap_check_template ?: "cached"; 1055 } 1056 1057 if (!strcmp(opt_overlap_check, "none")) { 1058 overlap_check_template = 0; 1059 } else if (!strcmp(opt_overlap_check, "constant")) { 1060 overlap_check_template = QCOW2_OL_CONSTANT; 1061 } else if (!strcmp(opt_overlap_check, "cached")) { 1062 overlap_check_template = QCOW2_OL_CACHED; 1063 } else if (!strcmp(opt_overlap_check, "all")) { 1064 overlap_check_template = QCOW2_OL_ALL; 1065 } else { 1066 error_setg(errp, "Unsupported value '%s' for qcow2 option " 1067 "'overlap-check'. Allowed are any of the following: " 1068 "none, constant, cached, all", opt_overlap_check); 1069 ret = -EINVAL; 1070 goto fail; 1071 } 1072 1073 r->overlap_check = 0; 1074 for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { 1075 /* overlap-check defines a template bitmask, but every flag may be 1076 * overwritten through the associated boolean option */ 1077 r->overlap_check |= 1078 qemu_opt_get_bool(opts, overlap_bool_option_names[i], 1079 overlap_check_template & (1 << i)) << i; 1080 } 1081 1082 r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; 1083 r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; 1084 r->discard_passthrough[QCOW2_DISCARD_REQUEST] = 1085 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, 1086 flags & BDRV_O_UNMAP); 1087 r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = 1088 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); 1089 r->discard_passthrough[QCOW2_DISCARD_OTHER] = 1090 qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); 1091 1092 switch (s->crypt_method_header) { 1093 case QCOW_CRYPT_NONE: 1094 if (encryptfmt) { 1095 error_setg(errp, "No encryption in image header, but options " 1096 "specified format '%s'", encryptfmt); 1097 ret = -EINVAL; 1098 goto fail; 1099 } 1100 break; 1101 1102 case QCOW_CRYPT_AES: 1103 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 1104 error_setg(errp, 1105 "Header reported 'aes' encryption format but " 1106 "options specify '%s'", encryptfmt); 1107 ret = -EINVAL; 1108 goto fail; 1109 } 1110 qdict_put_str(encryptopts, "format", "qcow"); 1111 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1112 break; 1113 1114 case QCOW_CRYPT_LUKS: 1115 if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { 1116 error_setg(errp, 1117 "Header reported 'luks' encryption format but " 1118 "options specify '%s'", encryptfmt); 1119 ret = -EINVAL; 1120 goto fail; 1121 } 1122 qdict_put_str(encryptopts, "format", "luks"); 1123 r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 1124 break; 1125 1126 default: 1127 error_setg(errp, "Unsupported encryption method %d", 1128 s->crypt_method_header); 1129 break; 1130 } 1131 if (s->crypt_method_header != QCOW_CRYPT_NONE && !r->crypto_opts) { 1132 ret = -EINVAL; 1133 goto fail; 1134 } 1135 1136 ret = 0; 1137 fail: 1138 qobject_unref(encryptopts); 1139 qemu_opts_del(opts); 1140 opts = NULL; 1141 return ret; 1142 } 1143 1144 static void qcow2_update_options_commit(BlockDriverState *bs, 1145 Qcow2ReopenState *r) 1146 { 1147 BDRVQcow2State *s = bs->opaque; 1148 int i; 1149 1150 if (s->l2_table_cache) { 1151 qcow2_cache_destroy(s->l2_table_cache); 1152 } 1153 if (s->refcount_block_cache) { 1154 qcow2_cache_destroy(s->refcount_block_cache); 1155 } 1156 s->l2_table_cache = r->l2_table_cache; 1157 s->refcount_block_cache = r->refcount_block_cache; 1158 s->l2_slice_size = r->l2_slice_size; 1159 1160 s->overlap_check = r->overlap_check; 1161 s->use_lazy_refcounts = r->use_lazy_refcounts; 1162 1163 for (i = 0; i < QCOW2_DISCARD_MAX; i++) { 1164 s->discard_passthrough[i] = r->discard_passthrough[i]; 1165 } 1166 1167 if (s->cache_clean_interval != r->cache_clean_interval) { 1168 cache_clean_timer_del(bs); 1169 s->cache_clean_interval = r->cache_clean_interval; 1170 cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); 1171 } 1172 1173 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1174 s->crypto_opts = r->crypto_opts; 1175 } 1176 1177 static void qcow2_update_options_abort(BlockDriverState *bs, 1178 Qcow2ReopenState *r) 1179 { 1180 if (r->l2_table_cache) { 1181 qcow2_cache_destroy(r->l2_table_cache); 1182 } 1183 if (r->refcount_block_cache) { 1184 qcow2_cache_destroy(r->refcount_block_cache); 1185 } 1186 qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); 1187 } 1188 1189 static int qcow2_update_options(BlockDriverState *bs, QDict *options, 1190 int flags, Error **errp) 1191 { 1192 Qcow2ReopenState r = {}; 1193 int ret; 1194 1195 ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); 1196 if (ret >= 0) { 1197 qcow2_update_options_commit(bs, &r); 1198 } else { 1199 qcow2_update_options_abort(bs, &r); 1200 } 1201 1202 return ret; 1203 } 1204 1205 /* Called with s->lock held. */ 1206 static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, 1207 int flags, Error **errp) 1208 { 1209 BDRVQcow2State *s = bs->opaque; 1210 unsigned int len, i; 1211 int ret = 0; 1212 QCowHeader header; 1213 Error *local_err = NULL; 1214 uint64_t ext_end; 1215 uint64_t l1_vm_state_index; 1216 bool update_header = false; 1217 1218 ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); 1219 if (ret < 0) { 1220 error_setg_errno(errp, -ret, "Could not read qcow2 header"); 1221 goto fail; 1222 } 1223 header.magic = be32_to_cpu(header.magic); 1224 header.version = be32_to_cpu(header.version); 1225 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 1226 header.backing_file_size = be32_to_cpu(header.backing_file_size); 1227 header.size = be64_to_cpu(header.size); 1228 header.cluster_bits = be32_to_cpu(header.cluster_bits); 1229 header.crypt_method = be32_to_cpu(header.crypt_method); 1230 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 1231 header.l1_size = be32_to_cpu(header.l1_size); 1232 header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); 1233 header.refcount_table_clusters = 1234 be32_to_cpu(header.refcount_table_clusters); 1235 header.snapshots_offset = be64_to_cpu(header.snapshots_offset); 1236 header.nb_snapshots = be32_to_cpu(header.nb_snapshots); 1237 1238 if (header.magic != QCOW_MAGIC) { 1239 error_setg(errp, "Image is not in qcow2 format"); 1240 ret = -EINVAL; 1241 goto fail; 1242 } 1243 if (header.version < 2 || header.version > 3) { 1244 error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); 1245 ret = -ENOTSUP; 1246 goto fail; 1247 } 1248 1249 s->qcow_version = header.version; 1250 1251 /* Initialise cluster size */ 1252 if (header.cluster_bits < MIN_CLUSTER_BITS || 1253 header.cluster_bits > MAX_CLUSTER_BITS) { 1254 error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, 1255 header.cluster_bits); 1256 ret = -EINVAL; 1257 goto fail; 1258 } 1259 1260 s->cluster_bits = header.cluster_bits; 1261 s->cluster_size = 1 << s->cluster_bits; 1262 s->cluster_sectors = 1 << (s->cluster_bits - BDRV_SECTOR_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, 1, errp); 1548 if (!s->crypto) { 1549 ret = -EINVAL; 1550 goto fail; 1551 } 1552 } else if (!(flags & BDRV_O_NO_IO)) { 1553 error_setg(errp, "Missing CRYPTO header for crypt method %d", 1554 s->crypt_method_header); 1555 ret = -EINVAL; 1556 goto fail; 1557 } 1558 } 1559 1560 /* read the backing file name */ 1561 if (header.backing_file_offset != 0) { 1562 len = header.backing_file_size; 1563 if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || 1564 len >= sizeof(bs->backing_file)) { 1565 error_setg(errp, "Backing file name too long"); 1566 ret = -EINVAL; 1567 goto fail; 1568 } 1569 ret = bdrv_pread(bs->file, header.backing_file_offset, 1570 bs->auto_backing_file, len); 1571 if (ret < 0) { 1572 error_setg_errno(errp, -ret, "Could not read backing file name"); 1573 goto fail; 1574 } 1575 bs->auto_backing_file[len] = '\0'; 1576 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 1577 bs->auto_backing_file); 1578 s->image_backing_file = g_strdup(bs->auto_backing_file); 1579 } 1580 1581 /* Internal snapshots */ 1582 s->snapshots_offset = header.snapshots_offset; 1583 s->nb_snapshots = header.nb_snapshots; 1584 1585 ret = qcow2_read_snapshots(bs); 1586 if (ret < 0) { 1587 error_setg_errno(errp, -ret, "Could not read snapshots"); 1588 goto fail; 1589 } 1590 1591 /* Clear unknown autoclear feature bits */ 1592 update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; 1593 update_header = 1594 update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE); 1595 if (update_header) { 1596 s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; 1597 } 1598 1599 /* == Handle persistent dirty bitmaps == 1600 * 1601 * We want load dirty bitmaps in three cases: 1602 * 1603 * 1. Normal open of the disk in active mode, not related to invalidation 1604 * after migration. 1605 * 1606 * 2. Invalidation of the target vm after pre-copy phase of migration, if 1607 * bitmaps are _not_ migrating through migration channel, i.e. 1608 * 'dirty-bitmaps' capability is disabled. 1609 * 1610 * 3. Invalidation of source vm after failed or canceled migration. 1611 * This is a very interesting case. There are two possible types of 1612 * bitmaps: 1613 * 1614 * A. Stored on inactivation and removed. They should be loaded from the 1615 * image. 1616 * 1617 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through 1618 * the migration channel (with dirty-bitmaps capability). 1619 * 1620 * On the other hand, there are two possible sub-cases: 1621 * 1622 * 3.1 disk was changed by somebody else while were inactive. In this 1623 * case all in-RAM dirty bitmaps (both persistent and not) are 1624 * definitely invalid. And we don't have any method to determine 1625 * this. 1626 * 1627 * Simple and safe thing is to just drop all the bitmaps of type B on 1628 * inactivation. But in this case we lose bitmaps in valid 4.2 case. 1629 * 1630 * On the other hand, resuming source vm, if disk was already changed 1631 * is a bad thing anyway: not only bitmaps, the whole vm state is 1632 * out of sync with disk. 1633 * 1634 * This means, that user or management tool, who for some reason 1635 * decided to resume source vm, after disk was already changed by 1636 * target vm, should at least drop all dirty bitmaps by hand. 1637 * 1638 * So, we can ignore this case for now, but TODO: "generation" 1639 * extension for qcow2, to determine, that image was changed after 1640 * last inactivation. And if it is changed, we will drop (or at least 1641 * mark as 'invalid' all the bitmaps of type B, both persistent 1642 * and not). 1643 * 1644 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved 1645 * to disk ('dirty-bitmaps' capability disabled), or not saved 1646 * ('dirty-bitmaps' capability enabled), but we don't need to care 1647 * of: let's load bitmaps as always: stored bitmaps will be loaded, 1648 * and not stored has flag IN_USE=1 in the image and will be skipped 1649 * on loading. 1650 * 1651 * One remaining possible case when we don't want load bitmaps: 1652 * 1653 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or 1654 * will be loaded on invalidation, no needs try loading them before) 1655 */ 1656 1657 if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { 1658 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ 1659 bool header_updated = qcow2_load_dirty_bitmaps(bs, &local_err); 1660 1661 update_header = update_header && !header_updated; 1662 } 1663 if (local_err != NULL) { 1664 error_propagate(errp, local_err); 1665 ret = -EINVAL; 1666 goto fail; 1667 } 1668 1669 if (update_header) { 1670 ret = qcow2_update_header(bs); 1671 if (ret < 0) { 1672 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 1673 goto fail; 1674 } 1675 } 1676 1677 bs->supported_zero_flags = header.version >= 3 ? BDRV_REQ_MAY_UNMAP : 0; 1678 1679 /* Repair image if dirty */ 1680 if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only && 1681 (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { 1682 BdrvCheckResult result = {0}; 1683 1684 ret = qcow2_co_check_locked(bs, &result, 1685 BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); 1686 if (ret < 0 || result.check_errors) { 1687 if (ret >= 0) { 1688 ret = -EIO; 1689 } 1690 error_setg_errno(errp, -ret, "Could not repair dirty image"); 1691 goto fail; 1692 } 1693 } 1694 1695 #ifdef DEBUG_ALLOC 1696 { 1697 BdrvCheckResult result = {0}; 1698 qcow2_check_refcounts(bs, &result, 0); 1699 } 1700 #endif 1701 1702 qemu_co_queue_init(&s->compress_wait_queue); 1703 1704 return ret; 1705 1706 fail: 1707 g_free(s->image_data_file); 1708 if (has_data_file(bs)) { 1709 bdrv_unref_child(bs, s->data_file); 1710 } 1711 g_free(s->unknown_header_fields); 1712 cleanup_unknown_header_ext(bs); 1713 qcow2_free_snapshots(bs); 1714 qcow2_refcount_close(bs); 1715 qemu_vfree(s->l1_table); 1716 /* else pre-write overlap checks in cache_destroy may crash */ 1717 s->l1_table = NULL; 1718 cache_clean_timer_del(bs); 1719 if (s->l2_table_cache) { 1720 qcow2_cache_destroy(s->l2_table_cache); 1721 } 1722 if (s->refcount_block_cache) { 1723 qcow2_cache_destroy(s->refcount_block_cache); 1724 } 1725 qcrypto_block_free(s->crypto); 1726 qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); 1727 return ret; 1728 } 1729 1730 typedef struct QCow2OpenCo { 1731 BlockDriverState *bs; 1732 QDict *options; 1733 int flags; 1734 Error **errp; 1735 int ret; 1736 } QCow2OpenCo; 1737 1738 static void coroutine_fn qcow2_open_entry(void *opaque) 1739 { 1740 QCow2OpenCo *qoc = opaque; 1741 BDRVQcow2State *s = qoc->bs->opaque; 1742 1743 qemu_co_mutex_lock(&s->lock); 1744 qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 1745 qemu_co_mutex_unlock(&s->lock); 1746 } 1747 1748 static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, 1749 Error **errp) 1750 { 1751 BDRVQcow2State *s = bs->opaque; 1752 QCow2OpenCo qoc = { 1753 .bs = bs, 1754 .options = options, 1755 .flags = flags, 1756 .errp = errp, 1757 .ret = -EINPROGRESS 1758 }; 1759 1760 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 1761 false, errp); 1762 if (!bs->file) { 1763 return -EINVAL; 1764 } 1765 1766 /* Initialise locks */ 1767 qemu_co_mutex_init(&s->lock); 1768 1769 if (qemu_in_coroutine()) { 1770 /* From bdrv_co_create. */ 1771 qcow2_open_entry(&qoc); 1772 } else { 1773 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 1774 qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry, &qoc)); 1775 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 1776 } 1777 return qoc.ret; 1778 } 1779 1780 static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) 1781 { 1782 BDRVQcow2State *s = bs->opaque; 1783 1784 if (bs->encrypted) { 1785 /* Encryption works on a sector granularity */ 1786 bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); 1787 } 1788 bs->bl.pwrite_zeroes_alignment = s->cluster_size; 1789 bs->bl.pdiscard_alignment = s->cluster_size; 1790 } 1791 1792 static int qcow2_reopen_prepare(BDRVReopenState *state, 1793 BlockReopenQueue *queue, Error **errp) 1794 { 1795 Qcow2ReopenState *r; 1796 int ret; 1797 1798 r = g_new0(Qcow2ReopenState, 1); 1799 state->opaque = r; 1800 1801 ret = qcow2_update_options_prepare(state->bs, r, state->options, 1802 state->flags, errp); 1803 if (ret < 0) { 1804 goto fail; 1805 } 1806 1807 /* We need to write out any unwritten data if we reopen read-only. */ 1808 if ((state->flags & BDRV_O_RDWR) == 0) { 1809 ret = qcow2_reopen_bitmaps_ro(state->bs, errp); 1810 if (ret < 0) { 1811 goto fail; 1812 } 1813 1814 ret = bdrv_flush(state->bs); 1815 if (ret < 0) { 1816 goto fail; 1817 } 1818 1819 ret = qcow2_mark_clean(state->bs); 1820 if (ret < 0) { 1821 goto fail; 1822 } 1823 } 1824 1825 return 0; 1826 1827 fail: 1828 qcow2_update_options_abort(state->bs, r); 1829 g_free(r); 1830 return ret; 1831 } 1832 1833 static void qcow2_reopen_commit(BDRVReopenState *state) 1834 { 1835 qcow2_update_options_commit(state->bs, state->opaque); 1836 g_free(state->opaque); 1837 } 1838 1839 static void qcow2_reopen_abort(BDRVReopenState *state) 1840 { 1841 qcow2_update_options_abort(state->bs, state->opaque); 1842 g_free(state->opaque); 1843 } 1844 1845 static void qcow2_join_options(QDict *options, QDict *old_options) 1846 { 1847 bool has_new_overlap_template = 1848 qdict_haskey(options, QCOW2_OPT_OVERLAP) || 1849 qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); 1850 bool has_new_total_cache_size = 1851 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); 1852 bool has_all_cache_options; 1853 1854 /* New overlap template overrides all old overlap options */ 1855 if (has_new_overlap_template) { 1856 qdict_del(old_options, QCOW2_OPT_OVERLAP); 1857 qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); 1858 qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); 1859 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); 1860 qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); 1861 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); 1862 qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); 1863 qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); 1864 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); 1865 qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); 1866 } 1867 1868 /* New total cache size overrides all old options */ 1869 if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { 1870 qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); 1871 qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 1872 } 1873 1874 qdict_join(options, old_options, false); 1875 1876 /* 1877 * If after merging all cache size options are set, an old total size is 1878 * overwritten. Do keep all options, however, if all three are new. The 1879 * resulting error message is what we want to happen. 1880 */ 1881 has_all_cache_options = 1882 qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || 1883 qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || 1884 qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); 1885 1886 if (has_all_cache_options && !has_new_total_cache_size) { 1887 qdict_del(options, QCOW2_OPT_CACHE_SIZE); 1888 } 1889 } 1890 1891 static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs, 1892 bool want_zero, 1893 int64_t offset, int64_t count, 1894 int64_t *pnum, int64_t *map, 1895 BlockDriverState **file) 1896 { 1897 BDRVQcow2State *s = bs->opaque; 1898 uint64_t cluster_offset; 1899 int index_in_cluster, ret; 1900 unsigned int bytes; 1901 int status = 0; 1902 1903 bytes = MIN(INT_MAX, count); 1904 qemu_co_mutex_lock(&s->lock); 1905 ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset); 1906 qemu_co_mutex_unlock(&s->lock); 1907 if (ret < 0) { 1908 return ret; 1909 } 1910 1911 *pnum = bytes; 1912 1913 if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) && 1914 !s->crypto) { 1915 index_in_cluster = offset & (s->cluster_size - 1); 1916 *map = cluster_offset | index_in_cluster; 1917 *file = s->data_file->bs; 1918 status |= BDRV_BLOCK_OFFSET_VALID; 1919 } 1920 if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) { 1921 status |= BDRV_BLOCK_ZERO; 1922 } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { 1923 status |= BDRV_BLOCK_DATA; 1924 } 1925 return status; 1926 } 1927 1928 static coroutine_fn int qcow2_handle_l2meta(BlockDriverState *bs, 1929 QCowL2Meta **pl2meta, 1930 bool link_l2) 1931 { 1932 int ret = 0; 1933 QCowL2Meta *l2meta = *pl2meta; 1934 1935 while (l2meta != NULL) { 1936 QCowL2Meta *next; 1937 1938 if (link_l2) { 1939 ret = qcow2_alloc_cluster_link_l2(bs, l2meta); 1940 if (ret) { 1941 goto out; 1942 } 1943 } else { 1944 qcow2_alloc_cluster_abort(bs, l2meta); 1945 } 1946 1947 /* Take the request off the list of running requests */ 1948 if (l2meta->nb_clusters != 0) { 1949 QLIST_REMOVE(l2meta, next_in_flight); 1950 } 1951 1952 qemu_co_queue_restart_all(&l2meta->dependent_requests); 1953 1954 next = l2meta->next; 1955 g_free(l2meta); 1956 l2meta = next; 1957 } 1958 out: 1959 *pl2meta = l2meta; 1960 return ret; 1961 } 1962 1963 static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, 1964 uint64_t bytes, QEMUIOVector *qiov, 1965 int flags) 1966 { 1967 BDRVQcow2State *s = bs->opaque; 1968 int offset_in_cluster; 1969 int ret; 1970 unsigned int cur_bytes; /* number of bytes in current iteration */ 1971 uint64_t cluster_offset = 0; 1972 uint64_t bytes_done = 0; 1973 QEMUIOVector hd_qiov; 1974 uint8_t *cluster_data = NULL; 1975 1976 qemu_iovec_init(&hd_qiov, qiov->niov); 1977 1978 qemu_co_mutex_lock(&s->lock); 1979 1980 while (bytes != 0) { 1981 1982 /* prepare next request */ 1983 cur_bytes = MIN(bytes, INT_MAX); 1984 if (s->crypto) { 1985 cur_bytes = MIN(cur_bytes, 1986 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 1987 } 1988 1989 ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset); 1990 if (ret < 0) { 1991 goto fail; 1992 } 1993 1994 offset_in_cluster = offset_into_cluster(s, offset); 1995 1996 qemu_iovec_reset(&hd_qiov); 1997 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes); 1998 1999 switch (ret) { 2000 case QCOW2_CLUSTER_UNALLOCATED: 2001 2002 if (bs->backing) { 2003 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 2004 qemu_co_mutex_unlock(&s->lock); 2005 ret = bdrv_co_preadv(bs->backing, offset, cur_bytes, 2006 &hd_qiov, 0); 2007 qemu_co_mutex_lock(&s->lock); 2008 if (ret < 0) { 2009 goto fail; 2010 } 2011 } else { 2012 /* Note: in this case, no need to wait */ 2013 qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); 2014 } 2015 break; 2016 2017 case QCOW2_CLUSTER_ZERO_PLAIN: 2018 case QCOW2_CLUSTER_ZERO_ALLOC: 2019 qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); 2020 break; 2021 2022 case QCOW2_CLUSTER_COMPRESSED: 2023 qemu_co_mutex_unlock(&s->lock); 2024 ret = qcow2_co_preadv_compressed(bs, cluster_offset, 2025 offset, cur_bytes, 2026 &hd_qiov); 2027 qemu_co_mutex_lock(&s->lock); 2028 if (ret < 0) { 2029 goto fail; 2030 } 2031 2032 break; 2033 2034 case QCOW2_CLUSTER_NORMAL: 2035 if ((cluster_offset & 511) != 0) { 2036 ret = -EIO; 2037 goto fail; 2038 } 2039 2040 if (bs->encrypted) { 2041 assert(s->crypto); 2042 2043 /* 2044 * For encrypted images, read everything into a temporary 2045 * contiguous buffer on which the AES functions can work. 2046 */ 2047 if (!cluster_data) { 2048 cluster_data = 2049 qemu_try_blockalign(s->data_file->bs, 2050 QCOW_MAX_CRYPT_CLUSTERS 2051 * s->cluster_size); 2052 if (cluster_data == NULL) { 2053 ret = -ENOMEM; 2054 goto fail; 2055 } 2056 } 2057 2058 assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2059 qemu_iovec_reset(&hd_qiov); 2060 qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes); 2061 } 2062 2063 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 2064 qemu_co_mutex_unlock(&s->lock); 2065 ret = bdrv_co_preadv(s->data_file, 2066 cluster_offset + offset_in_cluster, 2067 cur_bytes, &hd_qiov, 0); 2068 qemu_co_mutex_lock(&s->lock); 2069 if (ret < 0) { 2070 goto fail; 2071 } 2072 if (bs->encrypted) { 2073 assert(s->crypto); 2074 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); 2075 assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0); 2076 if (qcrypto_block_decrypt(s->crypto, 2077 (s->crypt_physical_offset ? 2078 cluster_offset + offset_in_cluster : 2079 offset), 2080 cluster_data, 2081 cur_bytes, 2082 NULL) < 0) { 2083 ret = -EIO; 2084 goto fail; 2085 } 2086 qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes); 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 bytes_done += cur_bytes; 2099 } 2100 ret = 0; 2101 2102 fail: 2103 qemu_co_mutex_unlock(&s->lock); 2104 2105 qemu_iovec_destroy(&hd_qiov); 2106 qemu_vfree(cluster_data); 2107 2108 return ret; 2109 } 2110 2111 /* Check if it's possible to merge a write request with the writing of 2112 * the data from the COW regions */ 2113 static bool merge_cow(uint64_t offset, unsigned bytes, 2114 QEMUIOVector *hd_qiov, QCowL2Meta *l2meta) 2115 { 2116 QCowL2Meta *m; 2117 2118 for (m = l2meta; m != NULL; m = m->next) { 2119 /* If both COW regions are empty then there's nothing to merge */ 2120 if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { 2121 continue; 2122 } 2123 2124 /* The data (middle) region must be immediately after the 2125 * start region */ 2126 if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { 2127 continue; 2128 } 2129 2130 /* The end region must be immediately after the data (middle) 2131 * region */ 2132 if (m->offset + m->cow_end.offset != offset + bytes) { 2133 continue; 2134 } 2135 2136 /* Make sure that adding both COW regions to the QEMUIOVector 2137 * does not exceed IOV_MAX */ 2138 if (hd_qiov->niov > IOV_MAX - 2) { 2139 continue; 2140 } 2141 2142 m->data_qiov = hd_qiov; 2143 return true; 2144 } 2145 2146 return false; 2147 } 2148 2149 static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset, 2150 uint64_t bytes, QEMUIOVector *qiov, 2151 int flags) 2152 { 2153 BDRVQcow2State *s = bs->opaque; 2154 int offset_in_cluster; 2155 int ret; 2156 unsigned int cur_bytes; /* number of sectors in current iteration */ 2157 uint64_t cluster_offset; 2158 QEMUIOVector hd_qiov; 2159 uint64_t bytes_done = 0; 2160 uint8_t *cluster_data = NULL; 2161 QCowL2Meta *l2meta = NULL; 2162 2163 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); 2164 2165 qemu_iovec_init(&hd_qiov, qiov->niov); 2166 2167 qemu_co_mutex_lock(&s->lock); 2168 2169 while (bytes != 0) { 2170 2171 l2meta = NULL; 2172 2173 trace_qcow2_writev_start_part(qemu_coroutine_self()); 2174 offset_in_cluster = offset_into_cluster(s, offset); 2175 cur_bytes = MIN(bytes, INT_MAX); 2176 if (bs->encrypted) { 2177 cur_bytes = MIN(cur_bytes, 2178 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size 2179 - offset_in_cluster); 2180 } 2181 2182 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 2183 &cluster_offset, &l2meta); 2184 if (ret < 0) { 2185 goto fail; 2186 } 2187 2188 assert((cluster_offset & 511) == 0); 2189 2190 qemu_iovec_reset(&hd_qiov); 2191 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes); 2192 2193 if (bs->encrypted) { 2194 assert(s->crypto); 2195 if (!cluster_data) { 2196 cluster_data = qemu_try_blockalign(bs->file->bs, 2197 QCOW_MAX_CRYPT_CLUSTERS 2198 * s->cluster_size); 2199 if (cluster_data == NULL) { 2200 ret = -ENOMEM; 2201 goto fail; 2202 } 2203 } 2204 2205 assert(hd_qiov.size <= 2206 QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); 2207 qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size); 2208 2209 if (qcrypto_block_encrypt(s->crypto, 2210 (s->crypt_physical_offset ? 2211 cluster_offset + offset_in_cluster : 2212 offset), 2213 cluster_data, 2214 cur_bytes, NULL) < 0) { 2215 ret = -EIO; 2216 goto fail; 2217 } 2218 2219 qemu_iovec_reset(&hd_qiov); 2220 qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes); 2221 } 2222 2223 ret = qcow2_pre_write_overlap_check(bs, 0, 2224 cluster_offset + offset_in_cluster, cur_bytes, true); 2225 if (ret < 0) { 2226 goto fail; 2227 } 2228 2229 /* If we need to do COW, check if it's possible to merge the 2230 * writing of the guest data together with that of the COW regions. 2231 * If it's not possible (or not necessary) then write the 2232 * guest data now. */ 2233 if (!merge_cow(offset, cur_bytes, &hd_qiov, l2meta)) { 2234 qemu_co_mutex_unlock(&s->lock); 2235 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); 2236 trace_qcow2_writev_data(qemu_coroutine_self(), 2237 cluster_offset + offset_in_cluster); 2238 ret = bdrv_co_pwritev(s->data_file, 2239 cluster_offset + offset_in_cluster, 2240 cur_bytes, &hd_qiov, 0); 2241 qemu_co_mutex_lock(&s->lock); 2242 if (ret < 0) { 2243 goto fail; 2244 } 2245 } 2246 2247 ret = qcow2_handle_l2meta(bs, &l2meta, true); 2248 if (ret) { 2249 goto fail; 2250 } 2251 2252 bytes -= cur_bytes; 2253 offset += cur_bytes; 2254 bytes_done += cur_bytes; 2255 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); 2256 } 2257 ret = 0; 2258 2259 fail: 2260 qcow2_handle_l2meta(bs, &l2meta, false); 2261 2262 qemu_co_mutex_unlock(&s->lock); 2263 2264 qemu_iovec_destroy(&hd_qiov); 2265 qemu_vfree(cluster_data); 2266 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 2267 2268 return ret; 2269 } 2270 2271 static int qcow2_inactivate(BlockDriverState *bs) 2272 { 2273 BDRVQcow2State *s = bs->opaque; 2274 int ret, result = 0; 2275 Error *local_err = NULL; 2276 2277 qcow2_store_persistent_dirty_bitmaps(bs, &local_err); 2278 if (local_err != NULL) { 2279 result = -EINVAL; 2280 error_reportf_err(local_err, "Lost persistent bitmaps during " 2281 "inactivation of node '%s': ", 2282 bdrv_get_device_or_node_name(bs)); 2283 } 2284 2285 ret = qcow2_cache_flush(bs, s->l2_table_cache); 2286 if (ret) { 2287 result = ret; 2288 error_report("Failed to flush the L2 table cache: %s", 2289 strerror(-ret)); 2290 } 2291 2292 ret = qcow2_cache_flush(bs, s->refcount_block_cache); 2293 if (ret) { 2294 result = ret; 2295 error_report("Failed to flush the refcount block cache: %s", 2296 strerror(-ret)); 2297 } 2298 2299 if (result == 0) { 2300 qcow2_mark_clean(bs); 2301 } 2302 2303 return result; 2304 } 2305 2306 static void qcow2_close(BlockDriverState *bs) 2307 { 2308 BDRVQcow2State *s = bs->opaque; 2309 qemu_vfree(s->l1_table); 2310 /* else pre-write overlap checks in cache_destroy may crash */ 2311 s->l1_table = NULL; 2312 2313 if (!(s->flags & BDRV_O_INACTIVE)) { 2314 qcow2_inactivate(bs); 2315 } 2316 2317 cache_clean_timer_del(bs); 2318 qcow2_cache_destroy(s->l2_table_cache); 2319 qcow2_cache_destroy(s->refcount_block_cache); 2320 2321 qcrypto_block_free(s->crypto); 2322 s->crypto = NULL; 2323 2324 g_free(s->unknown_header_fields); 2325 cleanup_unknown_header_ext(bs); 2326 2327 g_free(s->image_data_file); 2328 g_free(s->image_backing_file); 2329 g_free(s->image_backing_format); 2330 2331 if (has_data_file(bs)) { 2332 bdrv_unref_child(bs, s->data_file); 2333 } 2334 2335 qcow2_refcount_close(bs); 2336 qcow2_free_snapshots(bs); 2337 } 2338 2339 static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs, 2340 Error **errp) 2341 { 2342 BDRVQcow2State *s = bs->opaque; 2343 int flags = s->flags; 2344 QCryptoBlock *crypto = NULL; 2345 QDict *options; 2346 Error *local_err = NULL; 2347 int ret; 2348 2349 /* 2350 * Backing files are read-only which makes all of their metadata immutable, 2351 * that means we don't have to worry about reopening them here. 2352 */ 2353 2354 crypto = s->crypto; 2355 s->crypto = NULL; 2356 2357 qcow2_close(bs); 2358 2359 memset(s, 0, sizeof(BDRVQcow2State)); 2360 options = qdict_clone_shallow(bs->options); 2361 2362 flags &= ~BDRV_O_INACTIVE; 2363 qemu_co_mutex_lock(&s->lock); 2364 ret = qcow2_do_open(bs, options, flags, &local_err); 2365 qemu_co_mutex_unlock(&s->lock); 2366 qobject_unref(options); 2367 if (local_err) { 2368 error_propagate_prepend(errp, local_err, 2369 "Could not reopen qcow2 layer: "); 2370 bs->drv = NULL; 2371 return; 2372 } else if (ret < 0) { 2373 error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); 2374 bs->drv = NULL; 2375 return; 2376 } 2377 2378 s->crypto = crypto; 2379 } 2380 2381 static size_t header_ext_add(char *buf, uint32_t magic, const void *s, 2382 size_t len, size_t buflen) 2383 { 2384 QCowExtension *ext_backing_fmt = (QCowExtension*) buf; 2385 size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); 2386 2387 if (buflen < ext_len) { 2388 return -ENOSPC; 2389 } 2390 2391 *ext_backing_fmt = (QCowExtension) { 2392 .magic = cpu_to_be32(magic), 2393 .len = cpu_to_be32(len), 2394 }; 2395 2396 if (len) { 2397 memcpy(buf + sizeof(QCowExtension), s, len); 2398 } 2399 2400 return ext_len; 2401 } 2402 2403 /* 2404 * Updates the qcow2 header, including the variable length parts of it, i.e. 2405 * the backing file name and all extensions. qcow2 was not designed to allow 2406 * such changes, so if we run out of space (we can only use the first cluster) 2407 * this function may fail. 2408 * 2409 * Returns 0 on success, -errno in error cases. 2410 */ 2411 int qcow2_update_header(BlockDriverState *bs) 2412 { 2413 BDRVQcow2State *s = bs->opaque; 2414 QCowHeader *header; 2415 char *buf; 2416 size_t buflen = s->cluster_size; 2417 int ret; 2418 uint64_t total_size; 2419 uint32_t refcount_table_clusters; 2420 size_t header_length; 2421 Qcow2UnknownHeaderExtension *uext; 2422 2423 buf = qemu_blockalign(bs, buflen); 2424 2425 /* Header structure */ 2426 header = (QCowHeader*) buf; 2427 2428 if (buflen < sizeof(*header)) { 2429 ret = -ENOSPC; 2430 goto fail; 2431 } 2432 2433 header_length = sizeof(*header) + s->unknown_header_fields_size; 2434 total_size = bs->total_sectors * BDRV_SECTOR_SIZE; 2435 refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); 2436 2437 *header = (QCowHeader) { 2438 /* Version 2 fields */ 2439 .magic = cpu_to_be32(QCOW_MAGIC), 2440 .version = cpu_to_be32(s->qcow_version), 2441 .backing_file_offset = 0, 2442 .backing_file_size = 0, 2443 .cluster_bits = cpu_to_be32(s->cluster_bits), 2444 .size = cpu_to_be64(total_size), 2445 .crypt_method = cpu_to_be32(s->crypt_method_header), 2446 .l1_size = cpu_to_be32(s->l1_size), 2447 .l1_table_offset = cpu_to_be64(s->l1_table_offset), 2448 .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), 2449 .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), 2450 .nb_snapshots = cpu_to_be32(s->nb_snapshots), 2451 .snapshots_offset = cpu_to_be64(s->snapshots_offset), 2452 2453 /* Version 3 fields */ 2454 .incompatible_features = cpu_to_be64(s->incompatible_features), 2455 .compatible_features = cpu_to_be64(s->compatible_features), 2456 .autoclear_features = cpu_to_be64(s->autoclear_features), 2457 .refcount_order = cpu_to_be32(s->refcount_order), 2458 .header_length = cpu_to_be32(header_length), 2459 }; 2460 2461 /* For older versions, write a shorter header */ 2462 switch (s->qcow_version) { 2463 case 2: 2464 ret = offsetof(QCowHeader, incompatible_features); 2465 break; 2466 case 3: 2467 ret = sizeof(*header); 2468 break; 2469 default: 2470 ret = -EINVAL; 2471 goto fail; 2472 } 2473 2474 buf += ret; 2475 buflen -= ret; 2476 memset(buf, 0, buflen); 2477 2478 /* Preserve any unknown field in the header */ 2479 if (s->unknown_header_fields_size) { 2480 if (buflen < s->unknown_header_fields_size) { 2481 ret = -ENOSPC; 2482 goto fail; 2483 } 2484 2485 memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); 2486 buf += s->unknown_header_fields_size; 2487 buflen -= s->unknown_header_fields_size; 2488 } 2489 2490 /* Backing file format header extension */ 2491 if (s->image_backing_format) { 2492 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, 2493 s->image_backing_format, 2494 strlen(s->image_backing_format), 2495 buflen); 2496 if (ret < 0) { 2497 goto fail; 2498 } 2499 2500 buf += ret; 2501 buflen -= ret; 2502 } 2503 2504 /* External data file header extension */ 2505 if (has_data_file(bs) && s->image_data_file) { 2506 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, 2507 s->image_data_file, strlen(s->image_data_file), 2508 buflen); 2509 if (ret < 0) { 2510 goto fail; 2511 } 2512 2513 buf += ret; 2514 buflen -= ret; 2515 } 2516 2517 /* Full disk encryption header pointer extension */ 2518 if (s->crypto_header.offset != 0) { 2519 s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); 2520 s->crypto_header.length = cpu_to_be64(s->crypto_header.length); 2521 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, 2522 &s->crypto_header, sizeof(s->crypto_header), 2523 buflen); 2524 s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); 2525 s->crypto_header.length = be64_to_cpu(s->crypto_header.length); 2526 if (ret < 0) { 2527 goto fail; 2528 } 2529 buf += ret; 2530 buflen -= ret; 2531 } 2532 2533 /* Feature table */ 2534 if (s->qcow_version >= 3) { 2535 Qcow2Feature features[] = { 2536 { 2537 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2538 .bit = QCOW2_INCOMPAT_DIRTY_BITNR, 2539 .name = "dirty bit", 2540 }, 2541 { 2542 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2543 .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, 2544 .name = "corrupt bit", 2545 }, 2546 { 2547 .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, 2548 .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, 2549 .name = "external data file", 2550 }, 2551 { 2552 .type = QCOW2_FEAT_TYPE_COMPATIBLE, 2553 .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 2554 .name = "lazy refcounts", 2555 }, 2556 }; 2557 2558 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, 2559 features, sizeof(features), buflen); 2560 if (ret < 0) { 2561 goto fail; 2562 } 2563 buf += ret; 2564 buflen -= ret; 2565 } 2566 2567 /* Bitmap extension */ 2568 if (s->nb_bitmaps > 0) { 2569 Qcow2BitmapHeaderExt bitmaps_header = { 2570 .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), 2571 .bitmap_directory_size = 2572 cpu_to_be64(s->bitmap_directory_size), 2573 .bitmap_directory_offset = 2574 cpu_to_be64(s->bitmap_directory_offset) 2575 }; 2576 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, 2577 &bitmaps_header, sizeof(bitmaps_header), 2578 buflen); 2579 if (ret < 0) { 2580 goto fail; 2581 } 2582 buf += ret; 2583 buflen -= ret; 2584 } 2585 2586 /* Keep unknown header extensions */ 2587 QLIST_FOREACH(uext, &s->unknown_header_ext, next) { 2588 ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); 2589 if (ret < 0) { 2590 goto fail; 2591 } 2592 2593 buf += ret; 2594 buflen -= ret; 2595 } 2596 2597 /* End of header extensions */ 2598 ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); 2599 if (ret < 0) { 2600 goto fail; 2601 } 2602 2603 buf += ret; 2604 buflen -= ret; 2605 2606 /* Backing file name */ 2607 if (s->image_backing_file) { 2608 size_t backing_file_len = strlen(s->image_backing_file); 2609 2610 if (buflen < backing_file_len) { 2611 ret = -ENOSPC; 2612 goto fail; 2613 } 2614 2615 /* Using strncpy is ok here, since buf is not NUL-terminated. */ 2616 strncpy(buf, s->image_backing_file, buflen); 2617 2618 header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); 2619 header->backing_file_size = cpu_to_be32(backing_file_len); 2620 } 2621 2622 /* Write the new header */ 2623 ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size); 2624 if (ret < 0) { 2625 goto fail; 2626 } 2627 2628 ret = 0; 2629 fail: 2630 qemu_vfree(header); 2631 return ret; 2632 } 2633 2634 static int qcow2_change_backing_file(BlockDriverState *bs, 2635 const char *backing_file, const char *backing_fmt) 2636 { 2637 BDRVQcow2State *s = bs->opaque; 2638 2639 /* Adding a backing file means that the external data file alone won't be 2640 * enough to make sense of the content */ 2641 if (backing_file && data_file_is_raw(bs)) { 2642 return -EINVAL; 2643 } 2644 2645 if (backing_file && strlen(backing_file) > 1023) { 2646 return -EINVAL; 2647 } 2648 2649 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 2650 backing_file ?: ""); 2651 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 2652 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 2653 2654 g_free(s->image_backing_file); 2655 g_free(s->image_backing_format); 2656 2657 s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; 2658 s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; 2659 2660 return qcow2_update_header(bs); 2661 } 2662 2663 static int qcow2_crypt_method_from_format(const char *encryptfmt) 2664 { 2665 if (g_str_equal(encryptfmt, "luks")) { 2666 return QCOW_CRYPT_LUKS; 2667 } else if (g_str_equal(encryptfmt, "aes")) { 2668 return QCOW_CRYPT_AES; 2669 } else { 2670 return -EINVAL; 2671 } 2672 } 2673 2674 static int qcow2_set_up_encryption(BlockDriverState *bs, 2675 QCryptoBlockCreateOptions *cryptoopts, 2676 Error **errp) 2677 { 2678 BDRVQcow2State *s = bs->opaque; 2679 QCryptoBlock *crypto = NULL; 2680 int fmt, ret; 2681 2682 switch (cryptoopts->format) { 2683 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 2684 fmt = QCOW_CRYPT_LUKS; 2685 break; 2686 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 2687 fmt = QCOW_CRYPT_AES; 2688 break; 2689 default: 2690 error_setg(errp, "Crypto format not supported in qcow2"); 2691 return -EINVAL; 2692 } 2693 2694 s->crypt_method_header = fmt; 2695 2696 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 2697 qcow2_crypto_hdr_init_func, 2698 qcow2_crypto_hdr_write_func, 2699 bs, errp); 2700 if (!crypto) { 2701 return -EINVAL; 2702 } 2703 2704 ret = qcow2_update_header(bs); 2705 if (ret < 0) { 2706 error_setg_errno(errp, -ret, "Could not write encryption header"); 2707 goto out; 2708 } 2709 2710 ret = 0; 2711 out: 2712 qcrypto_block_free(crypto); 2713 return ret; 2714 } 2715 2716 /** 2717 * Preallocates metadata structures for data clusters between @offset (in the 2718 * guest disk) and @new_length (which is thus generally the new guest disk 2719 * size). 2720 * 2721 * Returns: 0 on success, -errno on failure. 2722 */ 2723 static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset, 2724 uint64_t new_length) 2725 { 2726 uint64_t bytes; 2727 uint64_t host_offset = 0; 2728 unsigned int cur_bytes; 2729 int ret; 2730 QCowL2Meta *meta; 2731 2732 assert(offset <= new_length); 2733 bytes = new_length - offset; 2734 2735 while (bytes) { 2736 cur_bytes = MIN(bytes, INT_MAX); 2737 ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, 2738 &host_offset, &meta); 2739 if (ret < 0) { 2740 return ret; 2741 } 2742 2743 while (meta) { 2744 QCowL2Meta *next = meta->next; 2745 2746 ret = qcow2_alloc_cluster_link_l2(bs, meta); 2747 if (ret < 0) { 2748 qcow2_free_any_clusters(bs, meta->alloc_offset, 2749 meta->nb_clusters, QCOW2_DISCARD_NEVER); 2750 return ret; 2751 } 2752 2753 /* There are no dependent requests, but we need to remove our 2754 * request from the list of in-flight requests */ 2755 QLIST_REMOVE(meta, next_in_flight); 2756 2757 g_free(meta); 2758 meta = next; 2759 } 2760 2761 /* TODO Preallocate data if requested */ 2762 2763 bytes -= cur_bytes; 2764 offset += cur_bytes; 2765 } 2766 2767 /* 2768 * It is expected that the image file is large enough to actually contain 2769 * all of the allocated clusters (otherwise we get failing reads after 2770 * EOF). Extend the image to the last allocated sector. 2771 */ 2772 if (host_offset != 0) { 2773 uint8_t data = 0; 2774 ret = bdrv_pwrite(bs->file, (host_offset + cur_bytes) - 1, 2775 &data, 1); 2776 if (ret < 0) { 2777 return ret; 2778 } 2779 } 2780 2781 return 0; 2782 } 2783 2784 /* qcow2_refcount_metadata_size: 2785 * @clusters: number of clusters to refcount (including data and L1/L2 tables) 2786 * @cluster_size: size of a cluster, in bytes 2787 * @refcount_order: refcount bits power-of-2 exponent 2788 * @generous_increase: allow for the refcount table to be 1.5x as large as it 2789 * needs to be 2790 * 2791 * Returns: Number of bytes required for refcount blocks and table metadata. 2792 */ 2793 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 2794 int refcount_order, bool generous_increase, 2795 uint64_t *refblock_count) 2796 { 2797 /* 2798 * Every host cluster is reference-counted, including metadata (even 2799 * refcount metadata is recursively included). 2800 * 2801 * An accurate formula for the size of refcount metadata size is difficult 2802 * to derive. An easier method of calculation is finding the fixed point 2803 * where no further refcount blocks or table clusters are required to 2804 * reference count every cluster. 2805 */ 2806 int64_t blocks_per_table_cluster = cluster_size / sizeof(uint64_t); 2807 int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); 2808 int64_t table = 0; /* number of refcount table clusters */ 2809 int64_t blocks = 0; /* number of refcount block clusters */ 2810 int64_t last; 2811 int64_t n = 0; 2812 2813 do { 2814 last = n; 2815 blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); 2816 table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); 2817 n = clusters + blocks + table; 2818 2819 if (n == last && generous_increase) { 2820 clusters += DIV_ROUND_UP(table, 2); 2821 n = 0; /* force another loop */ 2822 generous_increase = false; 2823 } 2824 } while (n != last); 2825 2826 if (refblock_count) { 2827 *refblock_count = blocks; 2828 } 2829 2830 return (blocks + table) * cluster_size; 2831 } 2832 2833 /** 2834 * qcow2_calc_prealloc_size: 2835 * @total_size: virtual disk size in bytes 2836 * @cluster_size: cluster size in bytes 2837 * @refcount_order: refcount bits power-of-2 exponent 2838 * 2839 * Returns: Total number of bytes required for the fully allocated image 2840 * (including metadata). 2841 */ 2842 static int64_t qcow2_calc_prealloc_size(int64_t total_size, 2843 size_t cluster_size, 2844 int refcount_order) 2845 { 2846 int64_t meta_size = 0; 2847 uint64_t nl1e, nl2e; 2848 int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); 2849 2850 /* header: 1 cluster */ 2851 meta_size += cluster_size; 2852 2853 /* total size of L2 tables */ 2854 nl2e = aligned_total_size / cluster_size; 2855 nl2e = ROUND_UP(nl2e, cluster_size / sizeof(uint64_t)); 2856 meta_size += nl2e * sizeof(uint64_t); 2857 2858 /* total size of L1 tables */ 2859 nl1e = nl2e * sizeof(uint64_t) / cluster_size; 2860 nl1e = ROUND_UP(nl1e, cluster_size / sizeof(uint64_t)); 2861 meta_size += nl1e * sizeof(uint64_t); 2862 2863 /* total size of refcount table and blocks */ 2864 meta_size += qcow2_refcount_metadata_size( 2865 (meta_size + aligned_total_size) / cluster_size, 2866 cluster_size, refcount_order, false, NULL); 2867 2868 return meta_size + aligned_total_size; 2869 } 2870 2871 static bool validate_cluster_size(size_t cluster_size, Error **errp) 2872 { 2873 int cluster_bits = ctz32(cluster_size); 2874 if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || 2875 (1 << cluster_bits) != cluster_size) 2876 { 2877 error_setg(errp, "Cluster size must be a power of two between %d and " 2878 "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); 2879 return false; 2880 } 2881 return true; 2882 } 2883 2884 static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, Error **errp) 2885 { 2886 size_t cluster_size; 2887 2888 cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 2889 DEFAULT_CLUSTER_SIZE); 2890 if (!validate_cluster_size(cluster_size, errp)) { 2891 return 0; 2892 } 2893 return cluster_size; 2894 } 2895 2896 static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) 2897 { 2898 char *buf; 2899 int ret; 2900 2901 buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); 2902 if (!buf) { 2903 ret = 3; /* default */ 2904 } else if (!strcmp(buf, "0.10")) { 2905 ret = 2; 2906 } else if (!strcmp(buf, "1.1")) { 2907 ret = 3; 2908 } else { 2909 error_setg(errp, "Invalid compatibility level: '%s'", buf); 2910 ret = -EINVAL; 2911 } 2912 g_free(buf); 2913 return ret; 2914 } 2915 2916 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, 2917 Error **errp) 2918 { 2919 uint64_t refcount_bits; 2920 2921 refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); 2922 if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { 2923 error_setg(errp, "Refcount width must be a power of two and may not " 2924 "exceed 64 bits"); 2925 return 0; 2926 } 2927 2928 if (version < 3 && refcount_bits != 16) { 2929 error_setg(errp, "Different refcount widths than 16 bits require " 2930 "compatibility level 1.1 or above (use compat=1.1 or " 2931 "greater)"); 2932 return 0; 2933 } 2934 2935 return refcount_bits; 2936 } 2937 2938 static int coroutine_fn 2939 qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) 2940 { 2941 BlockdevCreateOptionsQcow2 *qcow2_opts; 2942 QDict *options; 2943 2944 /* 2945 * Open the image file and write a minimal qcow2 header. 2946 * 2947 * We keep things simple and start with a zero-sized image. We also 2948 * do without refcount blocks or a L1 table for now. We'll fix the 2949 * inconsistency later. 2950 * 2951 * We do need a refcount table because growing the refcount table means 2952 * allocating two new refcount blocks - the seconds of which would be at 2953 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file 2954 * size for any qcow2 image. 2955 */ 2956 BlockBackend *blk = NULL; 2957 BlockDriverState *bs = NULL; 2958 BlockDriverState *data_bs = NULL; 2959 QCowHeader *header; 2960 size_t cluster_size; 2961 int version; 2962 int refcount_order; 2963 uint64_t* refcount_table; 2964 Error *local_err = NULL; 2965 int ret; 2966 2967 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); 2968 qcow2_opts = &create_options->u.qcow2; 2969 2970 bs = bdrv_open_blockdev_ref(qcow2_opts->file, errp); 2971 if (bs == NULL) { 2972 return -EIO; 2973 } 2974 2975 /* Validate options and set default values */ 2976 if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { 2977 error_setg(errp, "Image size must be a multiple of 512 bytes"); 2978 ret = -EINVAL; 2979 goto out; 2980 } 2981 2982 if (qcow2_opts->has_version) { 2983 switch (qcow2_opts->version) { 2984 case BLOCKDEV_QCOW2_VERSION_V2: 2985 version = 2; 2986 break; 2987 case BLOCKDEV_QCOW2_VERSION_V3: 2988 version = 3; 2989 break; 2990 default: 2991 g_assert_not_reached(); 2992 } 2993 } else { 2994 version = 3; 2995 } 2996 2997 if (qcow2_opts->has_cluster_size) { 2998 cluster_size = qcow2_opts->cluster_size; 2999 } else { 3000 cluster_size = DEFAULT_CLUSTER_SIZE; 3001 } 3002 3003 if (!validate_cluster_size(cluster_size, errp)) { 3004 ret = -EINVAL; 3005 goto out; 3006 } 3007 3008 if (!qcow2_opts->has_preallocation) { 3009 qcow2_opts->preallocation = PREALLOC_MODE_OFF; 3010 } 3011 if (qcow2_opts->has_backing_file && 3012 qcow2_opts->preallocation != PREALLOC_MODE_OFF) 3013 { 3014 error_setg(errp, "Backing file and preallocation cannot be used at " 3015 "the same time"); 3016 ret = -EINVAL; 3017 goto out; 3018 } 3019 if (qcow2_opts->has_backing_fmt && !qcow2_opts->has_backing_file) { 3020 error_setg(errp, "Backing format cannot be used without backing file"); 3021 ret = -EINVAL; 3022 goto out; 3023 } 3024 3025 if (!qcow2_opts->has_lazy_refcounts) { 3026 qcow2_opts->lazy_refcounts = false; 3027 } 3028 if (version < 3 && qcow2_opts->lazy_refcounts) { 3029 error_setg(errp, "Lazy refcounts only supported with compatibility " 3030 "level 1.1 and above (use version=v3 or greater)"); 3031 ret = -EINVAL; 3032 goto out; 3033 } 3034 3035 if (!qcow2_opts->has_refcount_bits) { 3036 qcow2_opts->refcount_bits = 16; 3037 } 3038 if (qcow2_opts->refcount_bits > 64 || 3039 !is_power_of_2(qcow2_opts->refcount_bits)) 3040 { 3041 error_setg(errp, "Refcount width must be a power of two and may not " 3042 "exceed 64 bits"); 3043 ret = -EINVAL; 3044 goto out; 3045 } 3046 if (version < 3 && qcow2_opts->refcount_bits != 16) { 3047 error_setg(errp, "Different refcount widths than 16 bits require " 3048 "compatibility level 1.1 or above (use version=v3 or " 3049 "greater)"); 3050 ret = -EINVAL; 3051 goto out; 3052 } 3053 refcount_order = ctz32(qcow2_opts->refcount_bits); 3054 3055 if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { 3056 error_setg(errp, "data-file-raw requires data-file"); 3057 ret = -EINVAL; 3058 goto out; 3059 } 3060 if (qcow2_opts->data_file_raw && qcow2_opts->has_backing_file) { 3061 error_setg(errp, "Backing file and data-file-raw cannot be used at " 3062 "the same time"); 3063 ret = -EINVAL; 3064 goto out; 3065 } 3066 3067 if (qcow2_opts->data_file) { 3068 if (version < 3) { 3069 error_setg(errp, "External data files are only supported with " 3070 "compatibility level 1.1 and above (use version=v3 or " 3071 "greater)"); 3072 ret = -EINVAL; 3073 goto out; 3074 } 3075 data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp); 3076 if (data_bs == NULL) { 3077 ret = -EIO; 3078 goto out; 3079 } 3080 } 3081 3082 /* Create BlockBackend to write to the image */ 3083 blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 3084 ret = blk_insert_bs(blk, bs, errp); 3085 if (ret < 0) { 3086 goto out; 3087 } 3088 blk_set_allow_write_beyond_eof(blk, true); 3089 3090 /* Clear the protocol layer and preallocate it if necessary */ 3091 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp); 3092 if (ret < 0) { 3093 goto out; 3094 } 3095 3096 /* Write the header */ 3097 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); 3098 header = g_malloc0(cluster_size); 3099 *header = (QCowHeader) { 3100 .magic = cpu_to_be32(QCOW_MAGIC), 3101 .version = cpu_to_be32(version), 3102 .cluster_bits = cpu_to_be32(ctz32(cluster_size)), 3103 .size = cpu_to_be64(0), 3104 .l1_table_offset = cpu_to_be64(0), 3105 .l1_size = cpu_to_be32(0), 3106 .refcount_table_offset = cpu_to_be64(cluster_size), 3107 .refcount_table_clusters = cpu_to_be32(1), 3108 .refcount_order = cpu_to_be32(refcount_order), 3109 .header_length = cpu_to_be32(sizeof(*header)), 3110 }; 3111 3112 /* We'll update this to correct value later */ 3113 header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 3114 3115 if (qcow2_opts->lazy_refcounts) { 3116 header->compatible_features |= 3117 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); 3118 } 3119 if (data_bs) { 3120 header->incompatible_features |= 3121 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); 3122 } 3123 if (qcow2_opts->data_file_raw) { 3124 header->autoclear_features |= 3125 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); 3126 } 3127 3128 ret = blk_pwrite(blk, 0, header, cluster_size, 0); 3129 g_free(header); 3130 if (ret < 0) { 3131 error_setg_errno(errp, -ret, "Could not write qcow2 header"); 3132 goto out; 3133 } 3134 3135 /* Write a refcount table with one refcount block */ 3136 refcount_table = g_malloc0(2 * cluster_size); 3137 refcount_table[0] = cpu_to_be64(2 * cluster_size); 3138 ret = blk_pwrite(blk, cluster_size, refcount_table, 2 * cluster_size, 0); 3139 g_free(refcount_table); 3140 3141 if (ret < 0) { 3142 error_setg_errno(errp, -ret, "Could not write refcount table"); 3143 goto out; 3144 } 3145 3146 blk_unref(blk); 3147 blk = NULL; 3148 3149 /* 3150 * And now open the image and make it consistent first (i.e. increase the 3151 * refcount of the cluster that is occupied by the header and the refcount 3152 * table) 3153 */ 3154 options = qdict_new(); 3155 qdict_put_str(options, "driver", "qcow2"); 3156 qdict_put_str(options, "file", bs->node_name); 3157 if (data_bs) { 3158 qdict_put_str(options, "data-file", data_bs->node_name); 3159 } 3160 blk = blk_new_open(NULL, NULL, options, 3161 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, 3162 &local_err); 3163 if (blk == NULL) { 3164 error_propagate(errp, local_err); 3165 ret = -EIO; 3166 goto out; 3167 } 3168 3169 ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); 3170 if (ret < 0) { 3171 error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " 3172 "header and refcount table"); 3173 goto out; 3174 3175 } else if (ret != 0) { 3176 error_report("Huh, first cluster in empty image is already in use?"); 3177 abort(); 3178 } 3179 3180 /* Set the external data file if necessary */ 3181 if (data_bs) { 3182 BDRVQcow2State *s = blk_bs(blk)->opaque; 3183 s->image_data_file = g_strdup(data_bs->filename); 3184 } 3185 3186 /* Create a full header (including things like feature table) */ 3187 ret = qcow2_update_header(blk_bs(blk)); 3188 if (ret < 0) { 3189 error_setg_errno(errp, -ret, "Could not update qcow2 header"); 3190 goto out; 3191 } 3192 3193 /* Okay, now that we have a valid image, let's give it the right size */ 3194 ret = blk_truncate(blk, qcow2_opts->size, qcow2_opts->preallocation, errp); 3195 if (ret < 0) { 3196 error_prepend(errp, "Could not resize image: "); 3197 goto out; 3198 } 3199 3200 /* Want a backing file? There you go.*/ 3201 if (qcow2_opts->has_backing_file) { 3202 const char *backing_format = NULL; 3203 3204 if (qcow2_opts->has_backing_fmt) { 3205 backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); 3206 } 3207 3208 ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, 3209 backing_format); 3210 if (ret < 0) { 3211 error_setg_errno(errp, -ret, "Could not assign backing file '%s' " 3212 "with format '%s'", qcow2_opts->backing_file, 3213 backing_format); 3214 goto out; 3215 } 3216 } 3217 3218 /* Want encryption? There you go. */ 3219 if (qcow2_opts->has_encrypt) { 3220 ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); 3221 if (ret < 0) { 3222 goto out; 3223 } 3224 } 3225 3226 blk_unref(blk); 3227 blk = NULL; 3228 3229 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. 3230 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to 3231 * have to setup decryption context. We're not doing any I/O on the top 3232 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does 3233 * not have effect. 3234 */ 3235 options = qdict_new(); 3236 qdict_put_str(options, "driver", "qcow2"); 3237 qdict_put_str(options, "file", bs->node_name); 3238 if (data_bs) { 3239 qdict_put_str(options, "data-file", data_bs->node_name); 3240 } 3241 blk = blk_new_open(NULL, NULL, options, 3242 BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, 3243 &local_err); 3244 if (blk == NULL) { 3245 error_propagate(errp, local_err); 3246 ret = -EIO; 3247 goto out; 3248 } 3249 3250 ret = 0; 3251 out: 3252 blk_unref(blk); 3253 bdrv_unref(bs); 3254 bdrv_unref(data_bs); 3255 return ret; 3256 } 3257 3258 static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opts, 3259 Error **errp) 3260 { 3261 BlockdevCreateOptions *create_options = NULL; 3262 QDict *qdict; 3263 Visitor *v; 3264 BlockDriverState *bs = NULL; 3265 BlockDriverState *data_bs = NULL; 3266 Error *local_err = NULL; 3267 const char *val; 3268 int ret; 3269 3270 /* Only the keyval visitor supports the dotted syntax needed for 3271 * encryption, so go through a QDict before getting a QAPI type. Ignore 3272 * options meant for the protocol layer so that the visitor doesn't 3273 * complain. */ 3274 qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, 3275 true); 3276 3277 /* Handle encryption options */ 3278 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 3279 if (val && !strcmp(val, "on")) { 3280 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 3281 } else if (val && !strcmp(val, "off")) { 3282 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 3283 } 3284 3285 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 3286 if (val && !strcmp(val, "aes")) { 3287 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 3288 } 3289 3290 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into 3291 * version=v2/v3 below. */ 3292 val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); 3293 if (val && !strcmp(val, "0.10")) { 3294 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); 3295 } else if (val && !strcmp(val, "1.1")) { 3296 qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); 3297 } 3298 3299 /* Change legacy command line options into QMP ones */ 3300 static const QDictRenames opt_renames[] = { 3301 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 3302 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 3303 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 3304 { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, 3305 { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, 3306 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 3307 { BLOCK_OPT_COMPAT_LEVEL, "version" }, 3308 { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, 3309 { NULL, NULL }, 3310 }; 3311 3312 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 3313 ret = -EINVAL; 3314 goto finish; 3315 } 3316 3317 /* Create and open the file (protocol layer) */ 3318 ret = bdrv_create_file(filename, opts, errp); 3319 if (ret < 0) { 3320 goto finish; 3321 } 3322 3323 bs = bdrv_open(filename, NULL, NULL, 3324 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 3325 if (bs == NULL) { 3326 ret = -EIO; 3327 goto finish; 3328 } 3329 3330 /* Create and open an external data file (protocol layer) */ 3331 val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); 3332 if (val) { 3333 ret = bdrv_create_file(val, opts, errp); 3334 if (ret < 0) { 3335 goto finish; 3336 } 3337 3338 data_bs = bdrv_open(val, NULL, NULL, 3339 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 3340 errp); 3341 if (data_bs == NULL) { 3342 ret = -EIO; 3343 goto finish; 3344 } 3345 3346 qdict_del(qdict, BLOCK_OPT_DATA_FILE); 3347 qdict_put_str(qdict, "data-file", data_bs->node_name); 3348 } 3349 3350 /* Set 'driver' and 'node' options */ 3351 qdict_put_str(qdict, "driver", "qcow2"); 3352 qdict_put_str(qdict, "file", bs->node_name); 3353 3354 /* Now get the QAPI type BlockdevCreateOptions */ 3355 v = qobject_input_visitor_new_flat_confused(qdict, errp); 3356 if (!v) { 3357 ret = -EINVAL; 3358 goto finish; 3359 } 3360 3361 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 3362 visit_free(v); 3363 3364 if (local_err) { 3365 error_propagate(errp, local_err); 3366 ret = -EINVAL; 3367 goto finish; 3368 } 3369 3370 /* Silently round up size */ 3371 create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size, 3372 BDRV_SECTOR_SIZE); 3373 3374 /* Create the qcow2 image (format layer) */ 3375 ret = qcow2_co_create(create_options, errp); 3376 if (ret < 0) { 3377 goto finish; 3378 } 3379 3380 ret = 0; 3381 finish: 3382 qobject_unref(qdict); 3383 bdrv_unref(bs); 3384 bdrv_unref(data_bs); 3385 qapi_free_BlockdevCreateOptions(create_options); 3386 return ret; 3387 } 3388 3389 3390 static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) 3391 { 3392 int64_t nr; 3393 int res; 3394 3395 /* Clamp to image length, before checking status of underlying sectors */ 3396 if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { 3397 bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; 3398 } 3399 3400 if (!bytes) { 3401 return true; 3402 } 3403 res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); 3404 return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; 3405 } 3406 3407 static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, 3408 int64_t offset, int bytes, BdrvRequestFlags flags) 3409 { 3410 int ret; 3411 BDRVQcow2State *s = bs->opaque; 3412 3413 uint32_t head = offset % s->cluster_size; 3414 uint32_t tail = (offset + bytes) % s->cluster_size; 3415 3416 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); 3417 if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { 3418 tail = 0; 3419 } 3420 3421 if (head || tail) { 3422 uint64_t off; 3423 unsigned int nr; 3424 3425 assert(head + bytes <= s->cluster_size); 3426 3427 /* check whether remainder of cluster already reads as zero */ 3428 if (!(is_zero(bs, offset - head, head) && 3429 is_zero(bs, offset + bytes, 3430 tail ? s->cluster_size - tail : 0))) { 3431 return -ENOTSUP; 3432 } 3433 3434 qemu_co_mutex_lock(&s->lock); 3435 /* We can have new write after previous check */ 3436 offset = QEMU_ALIGN_DOWN(offset, s->cluster_size); 3437 bytes = s->cluster_size; 3438 nr = s->cluster_size; 3439 ret = qcow2_get_cluster_offset(bs, offset, &nr, &off); 3440 if (ret != QCOW2_CLUSTER_UNALLOCATED && 3441 ret != QCOW2_CLUSTER_ZERO_PLAIN && 3442 ret != QCOW2_CLUSTER_ZERO_ALLOC) { 3443 qemu_co_mutex_unlock(&s->lock); 3444 return -ENOTSUP; 3445 } 3446 } else { 3447 qemu_co_mutex_lock(&s->lock); 3448 } 3449 3450 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); 3451 3452 /* Whatever is left can use real zero clusters */ 3453 ret = qcow2_cluster_zeroize(bs, offset, bytes, flags); 3454 qemu_co_mutex_unlock(&s->lock); 3455 3456 return ret; 3457 } 3458 3459 static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs, 3460 int64_t offset, int bytes) 3461 { 3462 int ret; 3463 BDRVQcow2State *s = bs->opaque; 3464 3465 if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { 3466 assert(bytes < s->cluster_size); 3467 /* Ignore partial clusters, except for the special case of the 3468 * complete partial cluster at the end of an unaligned file */ 3469 if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || 3470 offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { 3471 return -ENOTSUP; 3472 } 3473 } 3474 3475 qemu_co_mutex_lock(&s->lock); 3476 ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, 3477 false); 3478 qemu_co_mutex_unlock(&s->lock); 3479 return ret; 3480 } 3481 3482 static int coroutine_fn 3483 qcow2_co_copy_range_from(BlockDriverState *bs, 3484 BdrvChild *src, uint64_t src_offset, 3485 BdrvChild *dst, uint64_t dst_offset, 3486 uint64_t bytes, BdrvRequestFlags read_flags, 3487 BdrvRequestFlags write_flags) 3488 { 3489 BDRVQcow2State *s = bs->opaque; 3490 int ret; 3491 unsigned int cur_bytes; /* number of bytes in current iteration */ 3492 BdrvChild *child = NULL; 3493 BdrvRequestFlags cur_write_flags; 3494 3495 assert(!bs->encrypted); 3496 qemu_co_mutex_lock(&s->lock); 3497 3498 while (bytes != 0) { 3499 uint64_t copy_offset = 0; 3500 /* prepare next request */ 3501 cur_bytes = MIN(bytes, INT_MAX); 3502 cur_write_flags = write_flags; 3503 3504 ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, ©_offset); 3505 if (ret < 0) { 3506 goto out; 3507 } 3508 3509 switch (ret) { 3510 case QCOW2_CLUSTER_UNALLOCATED: 3511 if (bs->backing && bs->backing->bs) { 3512 int64_t backing_length = bdrv_getlength(bs->backing->bs); 3513 if (src_offset >= backing_length) { 3514 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3515 } else { 3516 child = bs->backing; 3517 cur_bytes = MIN(cur_bytes, backing_length - src_offset); 3518 copy_offset = src_offset; 3519 } 3520 } else { 3521 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3522 } 3523 break; 3524 3525 case QCOW2_CLUSTER_ZERO_PLAIN: 3526 case QCOW2_CLUSTER_ZERO_ALLOC: 3527 cur_write_flags |= BDRV_REQ_ZERO_WRITE; 3528 break; 3529 3530 case QCOW2_CLUSTER_COMPRESSED: 3531 ret = -ENOTSUP; 3532 goto out; 3533 3534 case QCOW2_CLUSTER_NORMAL: 3535 child = s->data_file; 3536 copy_offset += offset_into_cluster(s, src_offset); 3537 if ((copy_offset & 511) != 0) { 3538 ret = -EIO; 3539 goto out; 3540 } 3541 break; 3542 3543 default: 3544 abort(); 3545 } 3546 qemu_co_mutex_unlock(&s->lock); 3547 ret = bdrv_co_copy_range_from(child, 3548 copy_offset, 3549 dst, dst_offset, 3550 cur_bytes, read_flags, cur_write_flags); 3551 qemu_co_mutex_lock(&s->lock); 3552 if (ret < 0) { 3553 goto out; 3554 } 3555 3556 bytes -= cur_bytes; 3557 src_offset += cur_bytes; 3558 dst_offset += cur_bytes; 3559 } 3560 ret = 0; 3561 3562 out: 3563 qemu_co_mutex_unlock(&s->lock); 3564 return ret; 3565 } 3566 3567 static int coroutine_fn 3568 qcow2_co_copy_range_to(BlockDriverState *bs, 3569 BdrvChild *src, uint64_t src_offset, 3570 BdrvChild *dst, uint64_t dst_offset, 3571 uint64_t bytes, BdrvRequestFlags read_flags, 3572 BdrvRequestFlags write_flags) 3573 { 3574 BDRVQcow2State *s = bs->opaque; 3575 int offset_in_cluster; 3576 int ret; 3577 unsigned int cur_bytes; /* number of sectors in current iteration */ 3578 uint64_t cluster_offset; 3579 QCowL2Meta *l2meta = NULL; 3580 3581 assert(!bs->encrypted); 3582 3583 qemu_co_mutex_lock(&s->lock); 3584 3585 while (bytes != 0) { 3586 3587 l2meta = NULL; 3588 3589 offset_in_cluster = offset_into_cluster(s, dst_offset); 3590 cur_bytes = MIN(bytes, INT_MAX); 3591 3592 /* TODO: 3593 * If src->bs == dst->bs, we could simply copy by incrementing 3594 * the refcnt, without copying user data. 3595 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ 3596 ret = qcow2_alloc_cluster_offset(bs, dst_offset, &cur_bytes, 3597 &cluster_offset, &l2meta); 3598 if (ret < 0) { 3599 goto fail; 3600 } 3601 3602 assert((cluster_offset & 511) == 0); 3603 3604 ret = qcow2_pre_write_overlap_check(bs, 0, 3605 cluster_offset + offset_in_cluster, cur_bytes, true); 3606 if (ret < 0) { 3607 goto fail; 3608 } 3609 3610 qemu_co_mutex_unlock(&s->lock); 3611 ret = bdrv_co_copy_range_to(src, src_offset, 3612 s->data_file, 3613 cluster_offset + offset_in_cluster, 3614 cur_bytes, read_flags, write_flags); 3615 qemu_co_mutex_lock(&s->lock); 3616 if (ret < 0) { 3617 goto fail; 3618 } 3619 3620 ret = qcow2_handle_l2meta(bs, &l2meta, true); 3621 if (ret) { 3622 goto fail; 3623 } 3624 3625 bytes -= cur_bytes; 3626 src_offset += cur_bytes; 3627 dst_offset += cur_bytes; 3628 } 3629 ret = 0; 3630 3631 fail: 3632 qcow2_handle_l2meta(bs, &l2meta, false); 3633 3634 qemu_co_mutex_unlock(&s->lock); 3635 3636 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); 3637 3638 return ret; 3639 } 3640 3641 static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, 3642 PreallocMode prealloc, Error **errp) 3643 { 3644 BDRVQcow2State *s = bs->opaque; 3645 uint64_t old_length; 3646 int64_t new_l1_size; 3647 int ret; 3648 QDict *options; 3649 3650 if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && 3651 prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) 3652 { 3653 error_setg(errp, "Unsupported preallocation mode '%s'", 3654 PreallocMode_str(prealloc)); 3655 return -ENOTSUP; 3656 } 3657 3658 if (offset & 511) { 3659 error_setg(errp, "The new size must be a multiple of 512"); 3660 return -EINVAL; 3661 } 3662 3663 qemu_co_mutex_lock(&s->lock); 3664 3665 /* cannot proceed if image has snapshots */ 3666 if (s->nb_snapshots) { 3667 error_setg(errp, "Can't resize an image which has snapshots"); 3668 ret = -ENOTSUP; 3669 goto fail; 3670 } 3671 3672 /* cannot proceed if image has bitmaps */ 3673 if (qcow2_truncate_bitmaps_check(bs, errp)) { 3674 ret = -ENOTSUP; 3675 goto fail; 3676 } 3677 3678 old_length = bs->total_sectors * BDRV_SECTOR_SIZE; 3679 new_l1_size = size_to_l1(s, offset); 3680 3681 if (offset < old_length) { 3682 int64_t last_cluster, old_file_size; 3683 if (prealloc != PREALLOC_MODE_OFF) { 3684 error_setg(errp, 3685 "Preallocation can't be used for shrinking an image"); 3686 ret = -EINVAL; 3687 goto fail; 3688 } 3689 3690 ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), 3691 old_length - ROUND_UP(offset, 3692 s->cluster_size), 3693 QCOW2_DISCARD_ALWAYS, true); 3694 if (ret < 0) { 3695 error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); 3696 goto fail; 3697 } 3698 3699 ret = qcow2_shrink_l1_table(bs, new_l1_size); 3700 if (ret < 0) { 3701 error_setg_errno(errp, -ret, 3702 "Failed to reduce the number of L2 tables"); 3703 goto fail; 3704 } 3705 3706 ret = qcow2_shrink_reftable(bs); 3707 if (ret < 0) { 3708 error_setg_errno(errp, -ret, 3709 "Failed to discard unused refblocks"); 3710 goto fail; 3711 } 3712 3713 old_file_size = bdrv_getlength(bs->file->bs); 3714 if (old_file_size < 0) { 3715 error_setg_errno(errp, -old_file_size, 3716 "Failed to inquire current file length"); 3717 ret = old_file_size; 3718 goto fail; 3719 } 3720 last_cluster = qcow2_get_last_cluster(bs, old_file_size); 3721 if (last_cluster < 0) { 3722 error_setg_errno(errp, -last_cluster, 3723 "Failed to find the last cluster"); 3724 ret = last_cluster; 3725 goto fail; 3726 } 3727 if ((last_cluster + 1) * s->cluster_size < old_file_size) { 3728 Error *local_err = NULL; 3729 3730 bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, 3731 PREALLOC_MODE_OFF, &local_err); 3732 if (local_err) { 3733 warn_reportf_err(local_err, 3734 "Failed to truncate the tail of the image: "); 3735 } 3736 } 3737 } else { 3738 ret = qcow2_grow_l1_table(bs, new_l1_size, true); 3739 if (ret < 0) { 3740 error_setg_errno(errp, -ret, "Failed to grow the L1 table"); 3741 goto fail; 3742 } 3743 } 3744 3745 switch (prealloc) { 3746 case PREALLOC_MODE_OFF: 3747 break; 3748 3749 case PREALLOC_MODE_METADATA: 3750 ret = preallocate_co(bs, old_length, offset); 3751 if (ret < 0) { 3752 error_setg_errno(errp, -ret, "Preallocation failed"); 3753 goto fail; 3754 } 3755 break; 3756 3757 case PREALLOC_MODE_FALLOC: 3758 case PREALLOC_MODE_FULL: 3759 { 3760 int64_t allocation_start, host_offset, guest_offset; 3761 int64_t clusters_allocated; 3762 int64_t old_file_size, new_file_size; 3763 uint64_t nb_new_data_clusters, nb_new_l2_tables; 3764 3765 /* With a data file, preallocation means just allocating the metadata 3766 * and forwarding the truncate request to the data file */ 3767 if (has_data_file(bs)) { 3768 ret = preallocate_co(bs, old_length, offset); 3769 if (ret < 0) { 3770 error_setg_errno(errp, -ret, "Preallocation failed"); 3771 goto fail; 3772 } 3773 break; 3774 } 3775 3776 old_file_size = bdrv_getlength(bs->file->bs); 3777 if (old_file_size < 0) { 3778 error_setg_errno(errp, -old_file_size, 3779 "Failed to inquire current file length"); 3780 ret = old_file_size; 3781 goto fail; 3782 } 3783 old_file_size = ROUND_UP(old_file_size, s->cluster_size); 3784 3785 nb_new_data_clusters = DIV_ROUND_UP(offset - old_length, 3786 s->cluster_size); 3787 3788 /* This is an overestimation; we will not actually allocate space for 3789 * these in the file but just make sure the new refcount structures are 3790 * able to cover them so we will not have to allocate new refblocks 3791 * while entering the data blocks in the potentially new L2 tables. 3792 * (We do not actually care where the L2 tables are placed. Maybe they 3793 * are already allocated or they can be placed somewhere before 3794 * @old_file_size. It does not matter because they will be fully 3795 * allocated automatically, so they do not need to be covered by the 3796 * preallocation. All that matters is that we will not have to allocate 3797 * new refcount structures for them.) */ 3798 nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, 3799 s->cluster_size / sizeof(uint64_t)); 3800 /* The cluster range may not be aligned to L2 boundaries, so add one L2 3801 * table for a potential head/tail */ 3802 nb_new_l2_tables++; 3803 3804 allocation_start = qcow2_refcount_area(bs, old_file_size, 3805 nb_new_data_clusters + 3806 nb_new_l2_tables, 3807 true, 0, 0); 3808 if (allocation_start < 0) { 3809 error_setg_errno(errp, -allocation_start, 3810 "Failed to resize refcount structures"); 3811 ret = allocation_start; 3812 goto fail; 3813 } 3814 3815 clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, 3816 nb_new_data_clusters); 3817 if (clusters_allocated < 0) { 3818 error_setg_errno(errp, -clusters_allocated, 3819 "Failed to allocate data clusters"); 3820 ret = clusters_allocated; 3821 goto fail; 3822 } 3823 3824 assert(clusters_allocated == nb_new_data_clusters); 3825 3826 /* Allocate the data area */ 3827 new_file_size = allocation_start + 3828 nb_new_data_clusters * s->cluster_size; 3829 ret = bdrv_co_truncate(bs->file, new_file_size, prealloc, errp); 3830 if (ret < 0) { 3831 error_prepend(errp, "Failed to resize underlying file: "); 3832 qcow2_free_clusters(bs, allocation_start, 3833 nb_new_data_clusters * s->cluster_size, 3834 QCOW2_DISCARD_OTHER); 3835 goto fail; 3836 } 3837 3838 /* Create the necessary L2 entries */ 3839 host_offset = allocation_start; 3840 guest_offset = old_length; 3841 while (nb_new_data_clusters) { 3842 int64_t nb_clusters = MIN( 3843 nb_new_data_clusters, 3844 s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); 3845 QCowL2Meta allocation = { 3846 .offset = guest_offset, 3847 .alloc_offset = host_offset, 3848 .nb_clusters = nb_clusters, 3849 }; 3850 qemu_co_queue_init(&allocation.dependent_requests); 3851 3852 ret = qcow2_alloc_cluster_link_l2(bs, &allocation); 3853 if (ret < 0) { 3854 error_setg_errno(errp, -ret, "Failed to update L2 tables"); 3855 qcow2_free_clusters(bs, host_offset, 3856 nb_new_data_clusters * s->cluster_size, 3857 QCOW2_DISCARD_OTHER); 3858 goto fail; 3859 } 3860 3861 guest_offset += nb_clusters * s->cluster_size; 3862 host_offset += nb_clusters * s->cluster_size; 3863 nb_new_data_clusters -= nb_clusters; 3864 } 3865 break; 3866 } 3867 3868 default: 3869 g_assert_not_reached(); 3870 } 3871 3872 if (prealloc != PREALLOC_MODE_OFF) { 3873 /* Flush metadata before actually changing the image size */ 3874 ret = qcow2_write_caches(bs); 3875 if (ret < 0) { 3876 error_setg_errno(errp, -ret, 3877 "Failed to flush the preallocated area to disk"); 3878 goto fail; 3879 } 3880 } 3881 3882 bs->total_sectors = offset / BDRV_SECTOR_SIZE; 3883 3884 if (has_data_file(bs)) { 3885 if (prealloc == PREALLOC_MODE_METADATA) { 3886 prealloc = PREALLOC_MODE_OFF; 3887 } 3888 ret = bdrv_co_truncate(s->data_file, offset, prealloc, errp); 3889 if (ret < 0) { 3890 goto fail; 3891 } 3892 } 3893 3894 /* write updated header.size */ 3895 offset = cpu_to_be64(offset); 3896 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), 3897 &offset, sizeof(uint64_t)); 3898 if (ret < 0) { 3899 error_setg_errno(errp, -ret, "Failed to update the image size"); 3900 goto fail; 3901 } 3902 3903 s->l1_vm_state_index = new_l1_size; 3904 3905 /* Update cache sizes */ 3906 options = qdict_clone_shallow(bs->options); 3907 ret = qcow2_update_options(bs, options, s->flags, errp); 3908 qobject_unref(options); 3909 if (ret < 0) { 3910 goto fail; 3911 } 3912 ret = 0; 3913 fail: 3914 qemu_co_mutex_unlock(&s->lock); 3915 return ret; 3916 } 3917 3918 /* 3919 * qcow2_compress() 3920 * 3921 * @dest - destination buffer, @dest_size bytes 3922 * @src - source buffer, @src_size bytes 3923 * 3924 * Returns: compressed size on success 3925 * -1 destination buffer is not enough to store compressed data 3926 * -2 on any other error 3927 */ 3928 static ssize_t qcow2_compress(void *dest, size_t dest_size, 3929 const void *src, size_t src_size) 3930 { 3931 ssize_t ret; 3932 z_stream strm; 3933 3934 /* best compression, small window, no zlib header */ 3935 memset(&strm, 0, sizeof(strm)); 3936 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 3937 -12, 9, Z_DEFAULT_STRATEGY); 3938 if (ret != Z_OK) { 3939 return -2; 3940 } 3941 3942 /* strm.next_in is not const in old zlib versions, such as those used on 3943 * OpenBSD/NetBSD, so cast the const away */ 3944 strm.avail_in = src_size; 3945 strm.next_in = (void *) src; 3946 strm.avail_out = dest_size; 3947 strm.next_out = dest; 3948 3949 ret = deflate(&strm, Z_FINISH); 3950 if (ret == Z_STREAM_END) { 3951 ret = dest_size - strm.avail_out; 3952 } else { 3953 ret = (ret == Z_OK ? -1 : -2); 3954 } 3955 3956 deflateEnd(&strm); 3957 3958 return ret; 3959 } 3960 3961 /* 3962 * qcow2_decompress() 3963 * 3964 * Decompress some data (not more than @src_size bytes) to produce exactly 3965 * @dest_size bytes. 3966 * 3967 * @dest - destination buffer, @dest_size bytes 3968 * @src - source buffer, @src_size bytes 3969 * 3970 * Returns: 0 on success 3971 * -1 on fail 3972 */ 3973 static ssize_t qcow2_decompress(void *dest, size_t dest_size, 3974 const void *src, size_t src_size) 3975 { 3976 int ret = 0; 3977 z_stream strm; 3978 3979 memset(&strm, 0, sizeof(strm)); 3980 strm.avail_in = src_size; 3981 strm.next_in = (void *) src; 3982 strm.avail_out = dest_size; 3983 strm.next_out = dest; 3984 3985 ret = inflateInit2(&strm, -12); 3986 if (ret != Z_OK) { 3987 return -1; 3988 } 3989 3990 ret = inflate(&strm, Z_FINISH); 3991 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || strm.avail_out != 0) { 3992 /* We approve Z_BUF_ERROR because we need @dest buffer to be filled, but 3993 * @src buffer may be processed partly (because in qcow2 we know size of 3994 * compressed data with precision of one sector) */ 3995 ret = -1; 3996 } 3997 3998 inflateEnd(&strm); 3999 4000 return ret; 4001 } 4002 4003 #define MAX_COMPRESS_THREADS 4 4004 4005 typedef ssize_t (*Qcow2CompressFunc)(void *dest, size_t dest_size, 4006 const void *src, size_t src_size); 4007 typedef struct Qcow2CompressData { 4008 void *dest; 4009 size_t dest_size; 4010 const void *src; 4011 size_t src_size; 4012 ssize_t ret; 4013 4014 Qcow2CompressFunc func; 4015 } Qcow2CompressData; 4016 4017 static int qcow2_compress_pool_func(void *opaque) 4018 { 4019 Qcow2CompressData *data = opaque; 4020 4021 data->ret = data->func(data->dest, data->dest_size, 4022 data->src, data->src_size); 4023 4024 return 0; 4025 } 4026 4027 static void qcow2_compress_complete(void *opaque, int ret) 4028 { 4029 qemu_coroutine_enter(opaque); 4030 } 4031 4032 static ssize_t coroutine_fn 4033 qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size, 4034 const void *src, size_t src_size, Qcow2CompressFunc func) 4035 { 4036 BDRVQcow2State *s = bs->opaque; 4037 BlockAIOCB *acb; 4038 ThreadPool *pool = aio_get_thread_pool(bdrv_get_aio_context(bs)); 4039 Qcow2CompressData arg = { 4040 .dest = dest, 4041 .dest_size = dest_size, 4042 .src = src, 4043 .src_size = src_size, 4044 .func = func, 4045 }; 4046 4047 while (s->nb_compress_threads >= MAX_COMPRESS_THREADS) { 4048 qemu_co_queue_wait(&s->compress_wait_queue, NULL); 4049 } 4050 4051 s->nb_compress_threads++; 4052 acb = thread_pool_submit_aio(pool, qcow2_compress_pool_func, &arg, 4053 qcow2_compress_complete, 4054 qemu_coroutine_self()); 4055 4056 if (!acb) { 4057 s->nb_compress_threads--; 4058 return -EINVAL; 4059 } 4060 qemu_coroutine_yield(); 4061 s->nb_compress_threads--; 4062 qemu_co_queue_next(&s->compress_wait_queue); 4063 4064 return arg.ret; 4065 } 4066 4067 static ssize_t coroutine_fn 4068 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size, 4069 const void *src, size_t src_size) 4070 { 4071 return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, 4072 qcow2_compress); 4073 } 4074 4075 static ssize_t coroutine_fn 4076 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size, 4077 const void *src, size_t src_size) 4078 { 4079 return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, 4080 qcow2_decompress); 4081 } 4082 4083 /* XXX: put compressed sectors first, then all the cluster aligned 4084 tables to avoid losing bytes in alignment */ 4085 static coroutine_fn int 4086 qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset, 4087 uint64_t bytes, QEMUIOVector *qiov) 4088 { 4089 BDRVQcow2State *s = bs->opaque; 4090 QEMUIOVector hd_qiov; 4091 int ret; 4092 size_t out_len; 4093 uint8_t *buf, *out_buf; 4094 uint64_t cluster_offset; 4095 4096 if (has_data_file(bs)) { 4097 return -ENOTSUP; 4098 } 4099 4100 if (bytes == 0) { 4101 /* align end of file to a sector boundary to ease reading with 4102 sector based I/Os */ 4103 int64_t len = bdrv_getlength(bs->file->bs); 4104 if (len < 0) { 4105 return len; 4106 } 4107 return bdrv_co_truncate(bs->file, len, PREALLOC_MODE_OFF, NULL); 4108 } 4109 4110 if (offset_into_cluster(s, offset)) { 4111 return -EINVAL; 4112 } 4113 4114 buf = qemu_blockalign(bs, s->cluster_size); 4115 if (bytes != s->cluster_size) { 4116 if (bytes > s->cluster_size || 4117 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS) 4118 { 4119 qemu_vfree(buf); 4120 return -EINVAL; 4121 } 4122 /* Zero-pad last write if image size is not cluster aligned */ 4123 memset(buf + bytes, 0, s->cluster_size - bytes); 4124 } 4125 qemu_iovec_to_buf(qiov, 0, buf, bytes); 4126 4127 out_buf = g_malloc(s->cluster_size); 4128 4129 out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, 4130 buf, s->cluster_size); 4131 if (out_len == -2) { 4132 ret = -EINVAL; 4133 goto fail; 4134 } else if (out_len == -1) { 4135 /* could not compress: write normal cluster */ 4136 ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0); 4137 if (ret < 0) { 4138 goto fail; 4139 } 4140 goto success; 4141 } 4142 4143 qemu_co_mutex_lock(&s->lock); 4144 ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, 4145 &cluster_offset); 4146 if (ret < 0) { 4147 qemu_co_mutex_unlock(&s->lock); 4148 goto fail; 4149 } 4150 4151 ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); 4152 qemu_co_mutex_unlock(&s->lock); 4153 if (ret < 0) { 4154 goto fail; 4155 } 4156 4157 qemu_iovec_init_buf(&hd_qiov, out_buf, out_len); 4158 4159 BLKDBG_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); 4160 ret = bdrv_co_pwritev(s->data_file, cluster_offset, out_len, &hd_qiov, 0); 4161 if (ret < 0) { 4162 goto fail; 4163 } 4164 success: 4165 ret = 0; 4166 fail: 4167 qemu_vfree(buf); 4168 g_free(out_buf); 4169 return ret; 4170 } 4171 4172 static int coroutine_fn 4173 qcow2_co_preadv_compressed(BlockDriverState *bs, 4174 uint64_t file_cluster_offset, 4175 uint64_t offset, 4176 uint64_t bytes, 4177 QEMUIOVector *qiov) 4178 { 4179 BDRVQcow2State *s = bs->opaque; 4180 int ret = 0, csize, nb_csectors; 4181 uint64_t coffset; 4182 uint8_t *buf, *out_buf; 4183 QEMUIOVector local_qiov; 4184 int offset_in_cluster = offset_into_cluster(s, offset); 4185 4186 coffset = file_cluster_offset & s->cluster_offset_mask; 4187 nb_csectors = ((file_cluster_offset >> s->csize_shift) & s->csize_mask) + 1; 4188 csize = nb_csectors * 512 - (coffset & 511); 4189 4190 buf = g_try_malloc(csize); 4191 if (!buf) { 4192 return -ENOMEM; 4193 } 4194 qemu_iovec_init_buf(&local_qiov, buf, csize); 4195 4196 out_buf = qemu_blockalign(bs, s->cluster_size); 4197 4198 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 4199 ret = bdrv_co_preadv(bs->file, coffset, csize, &local_qiov, 0); 4200 if (ret < 0) { 4201 goto fail; 4202 } 4203 4204 if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) { 4205 ret = -EIO; 4206 goto fail; 4207 } 4208 4209 qemu_iovec_from_buf(qiov, 0, out_buf + offset_in_cluster, bytes); 4210 4211 fail: 4212 qemu_vfree(out_buf); 4213 g_free(buf); 4214 4215 return ret; 4216 } 4217 4218 static int make_completely_empty(BlockDriverState *bs) 4219 { 4220 BDRVQcow2State *s = bs->opaque; 4221 Error *local_err = NULL; 4222 int ret, l1_clusters; 4223 int64_t offset; 4224 uint64_t *new_reftable = NULL; 4225 uint64_t rt_entry, l1_size2; 4226 struct { 4227 uint64_t l1_offset; 4228 uint64_t reftable_offset; 4229 uint32_t reftable_clusters; 4230 } QEMU_PACKED l1_ofs_rt_ofs_cls; 4231 4232 ret = qcow2_cache_empty(bs, s->l2_table_cache); 4233 if (ret < 0) { 4234 goto fail; 4235 } 4236 4237 ret = qcow2_cache_empty(bs, s->refcount_block_cache); 4238 if (ret < 0) { 4239 goto fail; 4240 } 4241 4242 /* Refcounts will be broken utterly */ 4243 ret = qcow2_mark_dirty(bs); 4244 if (ret < 0) { 4245 goto fail; 4246 } 4247 4248 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4249 4250 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4251 l1_size2 = (uint64_t)s->l1_size * sizeof(uint64_t); 4252 4253 /* After this call, neither the in-memory nor the on-disk refcount 4254 * information accurately describe the actual references */ 4255 4256 ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset, 4257 l1_clusters * s->cluster_size, 0); 4258 if (ret < 0) { 4259 goto fail_broken_refcounts; 4260 } 4261 memset(s->l1_table, 0, l1_size2); 4262 4263 BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE); 4264 4265 /* Overwrite enough clusters at the beginning of the sectors to place 4266 * the refcount table, a refcount block and the L1 table in; this may 4267 * overwrite parts of the existing refcount and L1 table, which is not 4268 * an issue because the dirty flag is set, complete data loss is in fact 4269 * desired and partial data loss is consequently fine as well */ 4270 ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size, 4271 (2 + l1_clusters) * s->cluster_size, 0); 4272 /* This call (even if it failed overall) may have overwritten on-disk 4273 * refcount structures; in that case, the in-memory refcount information 4274 * will probably differ from the on-disk information which makes the BDS 4275 * unusable */ 4276 if (ret < 0) { 4277 goto fail_broken_refcounts; 4278 } 4279 4280 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE); 4281 BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE); 4282 4283 /* "Create" an empty reftable (one cluster) directly after the image 4284 * header and an empty L1 table three clusters after the image header; 4285 * the cluster between those two will be used as the first refblock */ 4286 l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size); 4287 l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size); 4288 l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1); 4289 ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset), 4290 &l1_ofs_rt_ofs_cls, sizeof(l1_ofs_rt_ofs_cls)); 4291 if (ret < 0) { 4292 goto fail_broken_refcounts; 4293 } 4294 4295 s->l1_table_offset = 3 * s->cluster_size; 4296 4297 new_reftable = g_try_new0(uint64_t, s->cluster_size / sizeof(uint64_t)); 4298 if (!new_reftable) { 4299 ret = -ENOMEM; 4300 goto fail_broken_refcounts; 4301 } 4302 4303 s->refcount_table_offset = s->cluster_size; 4304 s->refcount_table_size = s->cluster_size / sizeof(uint64_t); 4305 s->max_refcount_table_index = 0; 4306 4307 g_free(s->refcount_table); 4308 s->refcount_table = new_reftable; 4309 new_reftable = NULL; 4310 4311 /* Now the in-memory refcount information again corresponds to the on-disk 4312 * information (reftable is empty and no refblocks (the refblock cache is 4313 * empty)); however, this means some clusters (e.g. the image header) are 4314 * referenced, but not refcounted, but the normal qcow2 code assumes that 4315 * the in-memory information is always correct */ 4316 4317 BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); 4318 4319 /* Enter the first refblock into the reftable */ 4320 rt_entry = cpu_to_be64(2 * s->cluster_size); 4321 ret = bdrv_pwrite_sync(bs->file, s->cluster_size, 4322 &rt_entry, sizeof(rt_entry)); 4323 if (ret < 0) { 4324 goto fail_broken_refcounts; 4325 } 4326 s->refcount_table[0] = 2 * s->cluster_size; 4327 4328 s->free_cluster_index = 0; 4329 assert(3 + l1_clusters <= s->refcount_block_size); 4330 offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2); 4331 if (offset < 0) { 4332 ret = offset; 4333 goto fail_broken_refcounts; 4334 } else if (offset > 0) { 4335 error_report("First cluster in emptied image is in use"); 4336 abort(); 4337 } 4338 4339 /* Now finally the in-memory information corresponds to the on-disk 4340 * structures and is correct */ 4341 ret = qcow2_mark_clean(bs); 4342 if (ret < 0) { 4343 goto fail; 4344 } 4345 4346 ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, 4347 PREALLOC_MODE_OFF, &local_err); 4348 if (ret < 0) { 4349 error_report_err(local_err); 4350 goto fail; 4351 } 4352 4353 return 0; 4354 4355 fail_broken_refcounts: 4356 /* The BDS is unusable at this point. If we wanted to make it usable, we 4357 * would have to call qcow2_refcount_close(), qcow2_refcount_init(), 4358 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init() 4359 * again. However, because the functions which could have caused this error 4360 * path to be taken are used by those functions as well, it's very likely 4361 * that that sequence will fail as well. Therefore, just eject the BDS. */ 4362 bs->drv = NULL; 4363 4364 fail: 4365 g_free(new_reftable); 4366 return ret; 4367 } 4368 4369 static int qcow2_make_empty(BlockDriverState *bs) 4370 { 4371 BDRVQcow2State *s = bs->opaque; 4372 uint64_t offset, end_offset; 4373 int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size); 4374 int l1_clusters, ret = 0; 4375 4376 l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / sizeof(uint64_t)); 4377 4378 if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && 4379 3 + l1_clusters <= s->refcount_block_size && 4380 s->crypt_method_header != QCOW_CRYPT_LUKS) { 4381 /* The following function only works for qcow2 v3 images (it 4382 * requires the dirty flag) and only as long as there are no 4383 * features that reserve extra clusters (such as snapshots, 4384 * LUKS header, or persistent bitmaps), because it completely 4385 * empties the image. Furthermore, the L1 table and three 4386 * additional clusters (image header, refcount table, one 4387 * refcount block) have to fit inside one refcount block. */ 4388 return make_completely_empty(bs); 4389 } 4390 4391 /* This fallback code simply discards every active cluster; this is slow, 4392 * but works in all cases */ 4393 end_offset = bs->total_sectors * BDRV_SECTOR_SIZE; 4394 for (offset = 0; offset < end_offset; offset += step) { 4395 /* As this function is generally used after committing an external 4396 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the 4397 * default action for this kind of discard is to pass the discard, 4398 * which will ideally result in an actually smaller image file, as 4399 * is probably desired. */ 4400 ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset), 4401 QCOW2_DISCARD_SNAPSHOT, true); 4402 if (ret < 0) { 4403 break; 4404 } 4405 } 4406 4407 return ret; 4408 } 4409 4410 static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) 4411 { 4412 BDRVQcow2State *s = bs->opaque; 4413 int ret; 4414 4415 qemu_co_mutex_lock(&s->lock); 4416 ret = qcow2_write_caches(bs); 4417 qemu_co_mutex_unlock(&s->lock); 4418 4419 return ret; 4420 } 4421 4422 static ssize_t qcow2_measure_crypto_hdr_init_func(QCryptoBlock *block, 4423 size_t headerlen, void *opaque, Error **errp) 4424 { 4425 size_t *headerlenp = opaque; 4426 4427 /* Stash away the payload size */ 4428 *headerlenp = headerlen; 4429 return 0; 4430 } 4431 4432 static ssize_t qcow2_measure_crypto_hdr_write_func(QCryptoBlock *block, 4433 size_t offset, const uint8_t *buf, size_t buflen, 4434 void *opaque, Error **errp) 4435 { 4436 /* Discard the bytes, we're not actually writing to an image */ 4437 return buflen; 4438 } 4439 4440 /* Determine the number of bytes for the LUKS payload */ 4441 static bool qcow2_measure_luks_headerlen(QemuOpts *opts, size_t *len, 4442 Error **errp) 4443 { 4444 QDict *opts_qdict; 4445 QDict *cryptoopts_qdict; 4446 QCryptoBlockCreateOptions *cryptoopts; 4447 QCryptoBlock *crypto; 4448 4449 /* Extract "encrypt." options into a qdict */ 4450 opts_qdict = qemu_opts_to_qdict(opts, NULL); 4451 qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); 4452 qobject_unref(opts_qdict); 4453 4454 /* Build QCryptoBlockCreateOptions object from qdict */ 4455 qdict_put_str(cryptoopts_qdict, "format", "luks"); 4456 cryptoopts = block_crypto_create_opts_init(cryptoopts_qdict, errp); 4457 qobject_unref(cryptoopts_qdict); 4458 if (!cryptoopts) { 4459 return false; 4460 } 4461 4462 /* Fake LUKS creation in order to determine the payload size */ 4463 crypto = qcrypto_block_create(cryptoopts, "encrypt.", 4464 qcow2_measure_crypto_hdr_init_func, 4465 qcow2_measure_crypto_hdr_write_func, 4466 len, errp); 4467 qapi_free_QCryptoBlockCreateOptions(cryptoopts); 4468 if (!crypto) { 4469 return false; 4470 } 4471 4472 qcrypto_block_free(crypto); 4473 return true; 4474 } 4475 4476 static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs, 4477 Error **errp) 4478 { 4479 Error *local_err = NULL; 4480 BlockMeasureInfo *info; 4481 uint64_t required = 0; /* bytes that contribute to required size */ 4482 uint64_t virtual_size; /* disk size as seen by guest */ 4483 uint64_t refcount_bits; 4484 uint64_t l2_tables; 4485 uint64_t luks_payload_size = 0; 4486 size_t cluster_size; 4487 int version; 4488 char *optstr; 4489 PreallocMode prealloc; 4490 bool has_backing_file; 4491 bool has_luks; 4492 4493 /* Parse image creation options */ 4494 cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err); 4495 if (local_err) { 4496 goto err; 4497 } 4498 4499 version = qcow2_opt_get_version_del(opts, &local_err); 4500 if (local_err) { 4501 goto err; 4502 } 4503 4504 refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); 4505 if (local_err) { 4506 goto err; 4507 } 4508 4509 optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); 4510 prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr, 4511 PREALLOC_MODE_OFF, &local_err); 4512 g_free(optstr); 4513 if (local_err) { 4514 goto err; 4515 } 4516 4517 optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 4518 has_backing_file = !!optstr; 4519 g_free(optstr); 4520 4521 optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); 4522 has_luks = optstr && strcmp(optstr, "luks") == 0; 4523 g_free(optstr); 4524 4525 if (has_luks) { 4526 size_t headerlen; 4527 4528 if (!qcow2_measure_luks_headerlen(opts, &headerlen, &local_err)) { 4529 goto err; 4530 } 4531 4532 luks_payload_size = ROUND_UP(headerlen, cluster_size); 4533 } 4534 4535 virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 4536 virtual_size = ROUND_UP(virtual_size, cluster_size); 4537 4538 /* Check that virtual disk size is valid */ 4539 l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, 4540 cluster_size / sizeof(uint64_t)); 4541 if (l2_tables * sizeof(uint64_t) > QCOW_MAX_L1_SIZE) { 4542 error_setg(&local_err, "The image size is too large " 4543 "(try using a larger cluster size)"); 4544 goto err; 4545 } 4546 4547 /* Account for input image */ 4548 if (in_bs) { 4549 int64_t ssize = bdrv_getlength(in_bs); 4550 if (ssize < 0) { 4551 error_setg_errno(&local_err, -ssize, 4552 "Unable to get image virtual_size"); 4553 goto err; 4554 } 4555 4556 virtual_size = ROUND_UP(ssize, cluster_size); 4557 4558 if (has_backing_file) { 4559 /* We don't how much of the backing chain is shared by the input 4560 * image and the new image file. In the worst case the new image's 4561 * backing file has nothing in common with the input image. Be 4562 * conservative and assume all clusters need to be written. 4563 */ 4564 required = virtual_size; 4565 } else { 4566 int64_t offset; 4567 int64_t pnum = 0; 4568 4569 for (offset = 0; offset < ssize; offset += pnum) { 4570 int ret; 4571 4572 ret = bdrv_block_status_above(in_bs, NULL, offset, 4573 ssize - offset, &pnum, NULL, 4574 NULL); 4575 if (ret < 0) { 4576 error_setg_errno(&local_err, -ret, 4577 "Unable to get block status"); 4578 goto err; 4579 } 4580 4581 if (ret & BDRV_BLOCK_ZERO) { 4582 /* Skip zero regions (safe with no backing file) */ 4583 } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) == 4584 (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) { 4585 /* Extend pnum to end of cluster for next iteration */ 4586 pnum = ROUND_UP(offset + pnum, cluster_size) - offset; 4587 4588 /* Count clusters we've seen */ 4589 required += offset % cluster_size + pnum; 4590 } 4591 } 4592 } 4593 } 4594 4595 /* Take into account preallocation. Nothing special is needed for 4596 * PREALLOC_MODE_METADATA since metadata is always counted. 4597 */ 4598 if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { 4599 required = virtual_size; 4600 } 4601 4602 info = g_new(BlockMeasureInfo, 1); 4603 info->fully_allocated = 4604 qcow2_calc_prealloc_size(virtual_size, cluster_size, 4605 ctz32(refcount_bits)) + luks_payload_size; 4606 4607 /* Remove data clusters that are not required. This overestimates the 4608 * required size because metadata needed for the fully allocated file is 4609 * still counted. 4610 */ 4611 info->required = info->fully_allocated - virtual_size + required; 4612 return info; 4613 4614 err: 4615 error_propagate(errp, local_err); 4616 return NULL; 4617 } 4618 4619 static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 4620 { 4621 BDRVQcow2State *s = bs->opaque; 4622 bdi->unallocated_blocks_are_zero = true; 4623 bdi->cluster_size = s->cluster_size; 4624 bdi->vm_state_offset = qcow2_vm_state_offset(s); 4625 return 0; 4626 } 4627 4628 static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs, 4629 Error **errp) 4630 { 4631 BDRVQcow2State *s = bs->opaque; 4632 ImageInfoSpecific *spec_info; 4633 QCryptoBlockInfo *encrypt_info = NULL; 4634 Error *local_err = NULL; 4635 4636 if (s->crypto != NULL) { 4637 encrypt_info = qcrypto_block_get_info(s->crypto, &local_err); 4638 if (local_err) { 4639 error_propagate(errp, local_err); 4640 return NULL; 4641 } 4642 } 4643 4644 spec_info = g_new(ImageInfoSpecific, 1); 4645 *spec_info = (ImageInfoSpecific){ 4646 .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, 4647 .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1), 4648 }; 4649 if (s->qcow_version == 2) { 4650 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 4651 .compat = g_strdup("0.10"), 4652 .refcount_bits = s->refcount_bits, 4653 }; 4654 } else if (s->qcow_version == 3) { 4655 Qcow2BitmapInfoList *bitmaps; 4656 bitmaps = qcow2_get_bitmap_info_list(bs, &local_err); 4657 if (local_err) { 4658 error_propagate(errp, local_err); 4659 qapi_free_ImageInfoSpecific(spec_info); 4660 return NULL; 4661 } 4662 *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ 4663 .compat = g_strdup("1.1"), 4664 .lazy_refcounts = s->compatible_features & 4665 QCOW2_COMPAT_LAZY_REFCOUNTS, 4666 .has_lazy_refcounts = true, 4667 .corrupt = s->incompatible_features & 4668 QCOW2_INCOMPAT_CORRUPT, 4669 .has_corrupt = true, 4670 .refcount_bits = s->refcount_bits, 4671 .has_bitmaps = !!bitmaps, 4672 .bitmaps = bitmaps, 4673 .has_data_file = !!s->image_data_file, 4674 .data_file = g_strdup(s->image_data_file), 4675 .has_data_file_raw = has_data_file(bs), 4676 .data_file_raw = data_file_is_raw(bs), 4677 }; 4678 } else { 4679 /* if this assertion fails, this probably means a new version was 4680 * added without having it covered here */ 4681 assert(false); 4682 } 4683 4684 if (encrypt_info) { 4685 ImageInfoSpecificQCow2Encryption *qencrypt = 4686 g_new(ImageInfoSpecificQCow2Encryption, 1); 4687 switch (encrypt_info->format) { 4688 case Q_CRYPTO_BLOCK_FORMAT_QCOW: 4689 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES; 4690 break; 4691 case Q_CRYPTO_BLOCK_FORMAT_LUKS: 4692 qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS; 4693 qencrypt->u.luks = encrypt_info->u.luks; 4694 break; 4695 default: 4696 abort(); 4697 } 4698 /* Since we did shallow copy above, erase any pointers 4699 * in the original info */ 4700 memset(&encrypt_info->u, 0, sizeof(encrypt_info->u)); 4701 qapi_free_QCryptoBlockInfo(encrypt_info); 4702 4703 spec_info->u.qcow2.data->has_encrypt = true; 4704 spec_info->u.qcow2.data->encrypt = qencrypt; 4705 } 4706 4707 return spec_info; 4708 } 4709 4710 static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 4711 int64_t pos) 4712 { 4713 BDRVQcow2State *s = bs->opaque; 4714 4715 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); 4716 return bs->drv->bdrv_co_pwritev(bs, qcow2_vm_state_offset(s) + pos, 4717 qiov->size, qiov, 0); 4718 } 4719 4720 static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, 4721 int64_t pos) 4722 { 4723 BDRVQcow2State *s = bs->opaque; 4724 4725 BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); 4726 return bs->drv->bdrv_co_preadv(bs, qcow2_vm_state_offset(s) + pos, 4727 qiov->size, qiov, 0); 4728 } 4729 4730 /* 4731 * Downgrades an image's version. To achieve this, any incompatible features 4732 * have to be removed. 4733 */ 4734 static int qcow2_downgrade(BlockDriverState *bs, int target_version, 4735 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 4736 Error **errp) 4737 { 4738 BDRVQcow2State *s = bs->opaque; 4739 int current_version = s->qcow_version; 4740 int ret; 4741 4742 /* This is qcow2_downgrade(), not qcow2_upgrade() */ 4743 assert(target_version < current_version); 4744 4745 /* There are no other versions (now) that you can downgrade to */ 4746 assert(target_version == 2); 4747 4748 if (s->refcount_order != 4) { 4749 error_setg(errp, "compat=0.10 requires refcount_bits=16"); 4750 return -ENOTSUP; 4751 } 4752 4753 if (has_data_file(bs)) { 4754 error_setg(errp, "Cannot downgrade an image with a data file"); 4755 return -ENOTSUP; 4756 } 4757 4758 /* clear incompatible features */ 4759 if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { 4760 ret = qcow2_mark_clean(bs); 4761 if (ret < 0) { 4762 error_setg_errno(errp, -ret, "Failed to make the image clean"); 4763 return ret; 4764 } 4765 } 4766 4767 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in 4768 * the first place; if that happens nonetheless, returning -ENOTSUP is the 4769 * best thing to do anyway */ 4770 4771 if (s->incompatible_features) { 4772 error_setg(errp, "Cannot downgrade an image with incompatible features " 4773 "%#" PRIx64 " set", s->incompatible_features); 4774 return -ENOTSUP; 4775 } 4776 4777 /* since we can ignore compatible features, we can set them to 0 as well */ 4778 s->compatible_features = 0; 4779 /* if lazy refcounts have been used, they have already been fixed through 4780 * clearing the dirty flag */ 4781 4782 /* clearing autoclear features is trivial */ 4783 s->autoclear_features = 0; 4784 4785 ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); 4786 if (ret < 0) { 4787 error_setg_errno(errp, -ret, "Failed to turn zero into data clusters"); 4788 return ret; 4789 } 4790 4791 s->qcow_version = target_version; 4792 ret = qcow2_update_header(bs); 4793 if (ret < 0) { 4794 s->qcow_version = current_version; 4795 error_setg_errno(errp, -ret, "Failed to update the image header"); 4796 return ret; 4797 } 4798 return 0; 4799 } 4800 4801 typedef enum Qcow2AmendOperation { 4802 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be 4803 * statically initialized to so that the helper CB can discern the first 4804 * invocation from an operation change */ 4805 QCOW2_NO_OPERATION = 0, 4806 4807 QCOW2_CHANGING_REFCOUNT_ORDER, 4808 QCOW2_DOWNGRADING, 4809 } Qcow2AmendOperation; 4810 4811 typedef struct Qcow2AmendHelperCBInfo { 4812 /* The code coordinating the amend operations should only modify 4813 * these four fields; the rest will be managed by the CB */ 4814 BlockDriverAmendStatusCB *original_status_cb; 4815 void *original_cb_opaque; 4816 4817 Qcow2AmendOperation current_operation; 4818 4819 /* Total number of operations to perform (only set once) */ 4820 int total_operations; 4821 4822 /* The following fields are managed by the CB */ 4823 4824 /* Number of operations completed */ 4825 int operations_completed; 4826 4827 /* Cumulative offset of all completed operations */ 4828 int64_t offset_completed; 4829 4830 Qcow2AmendOperation last_operation; 4831 int64_t last_work_size; 4832 } Qcow2AmendHelperCBInfo; 4833 4834 static void qcow2_amend_helper_cb(BlockDriverState *bs, 4835 int64_t operation_offset, 4836 int64_t operation_work_size, void *opaque) 4837 { 4838 Qcow2AmendHelperCBInfo *info = opaque; 4839 int64_t current_work_size; 4840 int64_t projected_work_size; 4841 4842 if (info->current_operation != info->last_operation) { 4843 if (info->last_operation != QCOW2_NO_OPERATION) { 4844 info->offset_completed += info->last_work_size; 4845 info->operations_completed++; 4846 } 4847 4848 info->last_operation = info->current_operation; 4849 } 4850 4851 assert(info->total_operations > 0); 4852 assert(info->operations_completed < info->total_operations); 4853 4854 info->last_work_size = operation_work_size; 4855 4856 current_work_size = info->offset_completed + operation_work_size; 4857 4858 /* current_work_size is the total work size for (operations_completed + 1) 4859 * operations (which includes this one), so multiply it by the number of 4860 * operations not covered and divide it by the number of operations 4861 * covered to get a projection for the operations not covered */ 4862 projected_work_size = current_work_size * (info->total_operations - 4863 info->operations_completed - 1) 4864 / (info->operations_completed + 1); 4865 4866 info->original_status_cb(bs, info->offset_completed + operation_offset, 4867 current_work_size + projected_work_size, 4868 info->original_cb_opaque); 4869 } 4870 4871 static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, 4872 BlockDriverAmendStatusCB *status_cb, 4873 void *cb_opaque, 4874 Error **errp) 4875 { 4876 BDRVQcow2State *s = bs->opaque; 4877 int old_version = s->qcow_version, new_version = old_version; 4878 uint64_t new_size = 0; 4879 const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL; 4880 bool lazy_refcounts = s->use_lazy_refcounts; 4881 bool data_file_raw = data_file_is_raw(bs); 4882 const char *compat = NULL; 4883 uint64_t cluster_size = s->cluster_size; 4884 bool encrypt; 4885 int encformat; 4886 int refcount_bits = s->refcount_bits; 4887 int ret; 4888 QemuOptDesc *desc = opts->list->desc; 4889 Qcow2AmendHelperCBInfo helper_cb_info; 4890 4891 while (desc && desc->name) { 4892 if (!qemu_opt_find(opts, desc->name)) { 4893 /* only change explicitly defined options */ 4894 desc++; 4895 continue; 4896 } 4897 4898 if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { 4899 compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); 4900 if (!compat) { 4901 /* preserve default */ 4902 } else if (!strcmp(compat, "0.10")) { 4903 new_version = 2; 4904 } else if (!strcmp(compat, "1.1")) { 4905 new_version = 3; 4906 } else { 4907 error_setg(errp, "Unknown compatibility level %s", compat); 4908 return -EINVAL; 4909 } 4910 } else if (!strcmp(desc->name, BLOCK_OPT_PREALLOC)) { 4911 error_setg(errp, "Cannot change preallocation mode"); 4912 return -ENOTSUP; 4913 } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { 4914 new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); 4915 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { 4916 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); 4917 } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { 4918 backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); 4919 } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) { 4920 encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, 4921 !!s->crypto); 4922 4923 if (encrypt != !!s->crypto) { 4924 error_setg(errp, 4925 "Changing the encryption flag is not supported"); 4926 return -ENOTSUP; 4927 } 4928 } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT_FORMAT)) { 4929 encformat = qcow2_crypt_method_from_format( 4930 qemu_opt_get(opts, BLOCK_OPT_ENCRYPT_FORMAT)); 4931 4932 if (encformat != s->crypt_method_header) { 4933 error_setg(errp, 4934 "Changing the encryption format is not supported"); 4935 return -ENOTSUP; 4936 } 4937 } else if (g_str_has_prefix(desc->name, "encrypt.")) { 4938 error_setg(errp, 4939 "Changing the encryption parameters is not supported"); 4940 return -ENOTSUP; 4941 } else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) { 4942 cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 4943 cluster_size); 4944 if (cluster_size != s->cluster_size) { 4945 error_setg(errp, "Changing the cluster size is not supported"); 4946 return -ENOTSUP; 4947 } 4948 } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { 4949 lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, 4950 lazy_refcounts); 4951 } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { 4952 refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, 4953 refcount_bits); 4954 4955 if (refcount_bits <= 0 || refcount_bits > 64 || 4956 !is_power_of_2(refcount_bits)) 4957 { 4958 error_setg(errp, "Refcount width must be a power of two and " 4959 "may not exceed 64 bits"); 4960 return -EINVAL; 4961 } 4962 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) { 4963 data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE); 4964 if (data_file && !has_data_file(bs)) { 4965 error_setg(errp, "data-file can only be set for images that " 4966 "use an external data file"); 4967 return -EINVAL; 4968 } 4969 } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) { 4970 data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW, 4971 data_file_raw); 4972 if (data_file_raw && !data_file_is_raw(bs)) { 4973 error_setg(errp, "data-file-raw cannot be set on existing " 4974 "images"); 4975 return -EINVAL; 4976 } 4977 } else { 4978 /* if this point is reached, this probably means a new option was 4979 * added without having it covered here */ 4980 abort(); 4981 } 4982 4983 desc++; 4984 } 4985 4986 helper_cb_info = (Qcow2AmendHelperCBInfo){ 4987 .original_status_cb = status_cb, 4988 .original_cb_opaque = cb_opaque, 4989 .total_operations = (new_version < old_version) 4990 + (s->refcount_bits != refcount_bits) 4991 }; 4992 4993 /* Upgrade first (some features may require compat=1.1) */ 4994 if (new_version > old_version) { 4995 s->qcow_version = new_version; 4996 ret = qcow2_update_header(bs); 4997 if (ret < 0) { 4998 s->qcow_version = old_version; 4999 error_setg_errno(errp, -ret, "Failed to update the image header"); 5000 return ret; 5001 } 5002 } 5003 5004 if (s->refcount_bits != refcount_bits) { 5005 int refcount_order = ctz32(refcount_bits); 5006 5007 if (new_version < 3 && refcount_bits != 16) { 5008 error_setg(errp, "Refcount widths other than 16 bits require " 5009 "compatibility level 1.1 or above (use compat=1.1 or " 5010 "greater)"); 5011 return -EINVAL; 5012 } 5013 5014 helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; 5015 ret = qcow2_change_refcount_order(bs, refcount_order, 5016 &qcow2_amend_helper_cb, 5017 &helper_cb_info, errp); 5018 if (ret < 0) { 5019 return ret; 5020 } 5021 } 5022 5023 /* data-file-raw blocks backing files, so clear it first if requested */ 5024 if (data_file_raw) { 5025 s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5026 } else { 5027 s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW; 5028 } 5029 5030 if (data_file) { 5031 g_free(s->image_data_file); 5032 s->image_data_file = *data_file ? g_strdup(data_file) : NULL; 5033 } 5034 5035 ret = qcow2_update_header(bs); 5036 if (ret < 0) { 5037 error_setg_errno(errp, -ret, "Failed to update the image header"); 5038 return ret; 5039 } 5040 5041 if (backing_file || backing_format) { 5042 ret = qcow2_change_backing_file(bs, 5043 backing_file ?: s->image_backing_file, 5044 backing_format ?: s->image_backing_format); 5045 if (ret < 0) { 5046 error_setg_errno(errp, -ret, "Failed to change the backing file"); 5047 return ret; 5048 } 5049 } 5050 5051 if (s->use_lazy_refcounts != lazy_refcounts) { 5052 if (lazy_refcounts) { 5053 if (new_version < 3) { 5054 error_setg(errp, "Lazy refcounts only supported with " 5055 "compatibility level 1.1 and above (use compat=1.1 " 5056 "or greater)"); 5057 return -EINVAL; 5058 } 5059 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5060 ret = qcow2_update_header(bs); 5061 if (ret < 0) { 5062 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5063 error_setg_errno(errp, -ret, "Failed to update the image header"); 5064 return ret; 5065 } 5066 s->use_lazy_refcounts = true; 5067 } else { 5068 /* make image clean first */ 5069 ret = qcow2_mark_clean(bs); 5070 if (ret < 0) { 5071 error_setg_errno(errp, -ret, "Failed to make the image clean"); 5072 return ret; 5073 } 5074 /* now disallow lazy refcounts */ 5075 s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; 5076 ret = qcow2_update_header(bs); 5077 if (ret < 0) { 5078 s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; 5079 error_setg_errno(errp, -ret, "Failed to update the image header"); 5080 return ret; 5081 } 5082 s->use_lazy_refcounts = false; 5083 } 5084 } 5085 5086 if (new_size) { 5087 BlockBackend *blk = blk_new(BLK_PERM_RESIZE, BLK_PERM_ALL); 5088 ret = blk_insert_bs(blk, bs, errp); 5089 if (ret < 0) { 5090 blk_unref(blk); 5091 return ret; 5092 } 5093 5094 ret = blk_truncate(blk, new_size, PREALLOC_MODE_OFF, errp); 5095 blk_unref(blk); 5096 if (ret < 0) { 5097 return ret; 5098 } 5099 } 5100 5101 /* Downgrade last (so unsupported features can be removed before) */ 5102 if (new_version < old_version) { 5103 helper_cb_info.current_operation = QCOW2_DOWNGRADING; 5104 ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, 5105 &helper_cb_info, errp); 5106 if (ret < 0) { 5107 return ret; 5108 } 5109 } 5110 5111 return 0; 5112 } 5113 5114 /* 5115 * If offset or size are negative, respectively, they will not be included in 5116 * the BLOCK_IMAGE_CORRUPTED event emitted. 5117 * fatal will be ignored for read-only BDS; corruptions found there will always 5118 * be considered non-fatal. 5119 */ 5120 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 5121 int64_t size, const char *message_format, ...) 5122 { 5123 BDRVQcow2State *s = bs->opaque; 5124 const char *node_name; 5125 char *message; 5126 va_list ap; 5127 5128 fatal = fatal && bdrv_is_writable(bs); 5129 5130 if (s->signaled_corruption && 5131 (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) 5132 { 5133 return; 5134 } 5135 5136 va_start(ap, message_format); 5137 message = g_strdup_vprintf(message_format, ap); 5138 va_end(ap); 5139 5140 if (fatal) { 5141 fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " 5142 "corruption events will be suppressed\n", message); 5143 } else { 5144 fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " 5145 "corruption events will be suppressed\n", message); 5146 } 5147 5148 node_name = bdrv_get_node_name(bs); 5149 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 5150 *node_name != '\0', node_name, 5151 message, offset >= 0, offset, 5152 size >= 0, size, 5153 fatal); 5154 g_free(message); 5155 5156 if (fatal) { 5157 qcow2_mark_corrupt(bs); 5158 bs->drv = NULL; /* make BDS unusable */ 5159 } 5160 5161 s->signaled_corruption = true; 5162 } 5163 5164 static QemuOptsList qcow2_create_opts = { 5165 .name = "qcow2-create-opts", 5166 .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), 5167 .desc = { 5168 { 5169 .name = BLOCK_OPT_SIZE, 5170 .type = QEMU_OPT_SIZE, 5171 .help = "Virtual disk size" 5172 }, 5173 { 5174 .name = BLOCK_OPT_COMPAT_LEVEL, 5175 .type = QEMU_OPT_STRING, 5176 .help = "Compatibility level (0.10 or 1.1)" 5177 }, 5178 { 5179 .name = BLOCK_OPT_BACKING_FILE, 5180 .type = QEMU_OPT_STRING, 5181 .help = "File name of a base image" 5182 }, 5183 { 5184 .name = BLOCK_OPT_BACKING_FMT, 5185 .type = QEMU_OPT_STRING, 5186 .help = "Image format of the base image" 5187 }, 5188 { 5189 .name = BLOCK_OPT_DATA_FILE, 5190 .type = QEMU_OPT_STRING, 5191 .help = "File name of an external data file" 5192 }, 5193 { 5194 .name = BLOCK_OPT_DATA_FILE_RAW, 5195 .type = QEMU_OPT_BOOL, 5196 .help = "The external data file must stay valid as a raw image" 5197 }, 5198 { 5199 .name = BLOCK_OPT_ENCRYPT, 5200 .type = QEMU_OPT_BOOL, 5201 .help = "Encrypt the image with format 'aes'. (Deprecated " 5202 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", 5203 }, 5204 { 5205 .name = BLOCK_OPT_ENCRYPT_FORMAT, 5206 .type = QEMU_OPT_STRING, 5207 .help = "Encrypt the image, format choices: 'aes', 'luks'", 5208 }, 5209 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", 5210 "ID of secret providing qcow AES key or LUKS passphrase"), 5211 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), 5212 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), 5213 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), 5214 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), 5215 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), 5216 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), 5217 { 5218 .name = BLOCK_OPT_CLUSTER_SIZE, 5219 .type = QEMU_OPT_SIZE, 5220 .help = "qcow2 cluster size", 5221 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) 5222 }, 5223 { 5224 .name = BLOCK_OPT_PREALLOC, 5225 .type = QEMU_OPT_STRING, 5226 .help = "Preallocation mode (allowed values: off, metadata, " 5227 "falloc, full)" 5228 }, 5229 { 5230 .name = BLOCK_OPT_LAZY_REFCOUNTS, 5231 .type = QEMU_OPT_BOOL, 5232 .help = "Postpone refcount updates", 5233 .def_value_str = "off" 5234 }, 5235 { 5236 .name = BLOCK_OPT_REFCOUNT_BITS, 5237 .type = QEMU_OPT_NUMBER, 5238 .help = "Width of a reference count entry in bits", 5239 .def_value_str = "16" 5240 }, 5241 { /* end of list */ } 5242 } 5243 }; 5244 5245 static const char *const qcow2_strong_runtime_opts[] = { 5246 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 5247 5248 NULL 5249 }; 5250 5251 BlockDriver bdrv_qcow2 = { 5252 .format_name = "qcow2", 5253 .instance_size = sizeof(BDRVQcow2State), 5254 .bdrv_probe = qcow2_probe, 5255 .bdrv_open = qcow2_open, 5256 .bdrv_close = qcow2_close, 5257 .bdrv_reopen_prepare = qcow2_reopen_prepare, 5258 .bdrv_reopen_commit = qcow2_reopen_commit, 5259 .bdrv_reopen_abort = qcow2_reopen_abort, 5260 .bdrv_join_options = qcow2_join_options, 5261 .bdrv_child_perm = bdrv_format_default_perms, 5262 .bdrv_co_create_opts = qcow2_co_create_opts, 5263 .bdrv_co_create = qcow2_co_create, 5264 .bdrv_has_zero_init = bdrv_has_zero_init_1, 5265 .bdrv_co_block_status = qcow2_co_block_status, 5266 5267 .bdrv_co_preadv = qcow2_co_preadv, 5268 .bdrv_co_pwritev = qcow2_co_pwritev, 5269 .bdrv_co_flush_to_os = qcow2_co_flush_to_os, 5270 5271 .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes, 5272 .bdrv_co_pdiscard = qcow2_co_pdiscard, 5273 .bdrv_co_copy_range_from = qcow2_co_copy_range_from, 5274 .bdrv_co_copy_range_to = qcow2_co_copy_range_to, 5275 .bdrv_co_truncate = qcow2_co_truncate, 5276 .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed, 5277 .bdrv_make_empty = qcow2_make_empty, 5278 5279 .bdrv_snapshot_create = qcow2_snapshot_create, 5280 .bdrv_snapshot_goto = qcow2_snapshot_goto, 5281 .bdrv_snapshot_delete = qcow2_snapshot_delete, 5282 .bdrv_snapshot_list = qcow2_snapshot_list, 5283 .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, 5284 .bdrv_measure = qcow2_measure, 5285 .bdrv_get_info = qcow2_get_info, 5286 .bdrv_get_specific_info = qcow2_get_specific_info, 5287 5288 .bdrv_save_vmstate = qcow2_save_vmstate, 5289 .bdrv_load_vmstate = qcow2_load_vmstate, 5290 5291 .supports_backing = true, 5292 .bdrv_change_backing_file = qcow2_change_backing_file, 5293 5294 .bdrv_refresh_limits = qcow2_refresh_limits, 5295 .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache, 5296 .bdrv_inactivate = qcow2_inactivate, 5297 5298 .create_opts = &qcow2_create_opts, 5299 .strong_runtime_opts = qcow2_strong_runtime_opts, 5300 .mutable_opts = mutable_opts, 5301 .bdrv_co_check = qcow2_co_check, 5302 .bdrv_amend_options = qcow2_amend_options, 5303 5304 .bdrv_detach_aio_context = qcow2_detach_aio_context, 5305 .bdrv_attach_aio_context = qcow2_attach_aio_context, 5306 5307 .bdrv_reopen_bitmaps_rw = qcow2_reopen_bitmaps_rw, 5308 .bdrv_can_store_new_dirty_bitmap = qcow2_can_store_new_dirty_bitmap, 5309 .bdrv_remove_persistent_dirty_bitmap = qcow2_remove_persistent_dirty_bitmap, 5310 }; 5311 5312 static void bdrv_qcow2_init(void) 5313 { 5314 bdrv_register(&bdrv_qcow2); 5315 } 5316 5317 block_init(bdrv_qcow2_init); 5318