| 1 | /* |
| 2 | * Block driver for the QCOW version 2 format |
| 3 | * |
| 4 | * Copyright (c) 2004-2006 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | #include "qemu/osdep.h" |
| 26 | |
| 27 | #include "block/qdict.h" |
| 28 | #include "system/block-backend.h" |
| 29 | #include "qemu/main-loop.h" |
| 30 | #include "qemu/module.h" |
| 31 | #include "qcow2.h" |
| 32 | #include "qemu/error-report.h" |
| 33 | #include "qapi/error.h" |
| 34 | #include "qapi/qapi-events-block-core.h" |
| 35 | #include "qobject/qdict.h" |
| 36 | #include "qobject/qstring.h" |
| 37 | #include "trace.h" |
| 38 | #include "qemu/option_int.h" |
| 39 | #include "qemu/cutils.h" |
| 40 | #include "qemu/bswap.h" |
| 41 | #include "qemu/memalign.h" |
| 42 | #include "qapi/qobject-input-visitor.h" |
| 43 | #include "qapi/qapi-visit-block-core.h" |
| 44 | #include "crypto.h" |
| 45 | #include "block/aio_task.h" |
| 46 | #include "block/dirty-bitmap.h" |
| 47 | |
| 48 | /* |
| 49 | Differences with QCOW: |
| 50 | |
| 51 | - Support for multiple incremental snapshots. |
| 52 | - Memory management by reference counts. |
| 53 | - Clusters which have a reference count of one have the bit |
| 54 | QCOW_OFLAG_COPIED to optimize write performance. |
| 55 | - Size of compressed clusters is stored in sectors to reduce bit usage |
| 56 | in the cluster offsets. |
| 57 | - Support for storing additional data (such as the VM state) in the |
| 58 | snapshots. |
| 59 | - If a backing store is used, the cluster size is not constrained |
| 60 | (could be backported to QCOW). |
| 61 | - L2 tables have always a size of one cluster. |
| 62 | */ |
| 63 | |
| 64 | |
| 65 | typedef struct { |
| 66 | uint32_t magic; |
| 67 | uint32_t len; |
| 68 | } QEMU_PACKED QCowExtension; |
| 69 | |
| 70 | #define QCOW2_EXT_MAGIC_END 0 |
| 71 | #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca |
| 72 | #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 |
| 73 | #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 |
| 74 | #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 |
| 75 | #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 |
| 76 | |
| 77 | static int coroutine_fn |
| 78 | qcow2_co_preadv_compressed(BlockDriverState *bs, |
| 79 | uint64_t l2_entry, |
| 80 | uint64_t offset, |
| 81 | uint64_t bytes, |
| 82 | QEMUIOVector *qiov, |
| 83 | size_t qiov_offset); |
| 84 | |
| 85 | static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) |
| 86 | { |
| 87 | const QCowHeader *cow_header = (const void *)buf; |
| 88 | |
| 89 | if (buf_size >= sizeof(QCowHeader) && |
| 90 | be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
| 91 | be32_to_cpu(cow_header->version) >= 2) |
| 92 | return 100; |
| 93 | else |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | |
| 98 | static int GRAPH_RDLOCK |
| 99 | qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, |
| 100 | uint8_t *buf, size_t buflen, |
| 101 | void *opaque, Error **errp) |
| 102 | { |
| 103 | BlockDriverState *bs = opaque; |
| 104 | BDRVQcow2State *s = bs->opaque; |
| 105 | ssize_t ret; |
| 106 | |
| 107 | if ((offset + buflen) > s->crypto_header.length) { |
| 108 | error_setg(errp, "Request for data outside of extension header"); |
| 109 | return -1; |
| 110 | } |
| 111 | |
| 112 | ret = bdrv_pread(bs->file, s->crypto_header.offset + offset, buflen, buf, |
| 113 | 0); |
| 114 | if (ret < 0) { |
| 115 | error_setg_errno(errp, -ret, "Could not read encryption header"); |
| 116 | return -1; |
| 117 | } |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | |
| 122 | static int coroutine_fn GRAPH_RDLOCK |
| 123 | qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, void *opaque, |
| 124 | Error **errp) |
| 125 | { |
| 126 | BlockDriverState *bs = opaque; |
| 127 | BDRVQcow2State *s = bs->opaque; |
| 128 | int64_t ret; |
| 129 | int64_t clusterlen; |
| 130 | |
| 131 | ret = qcow2_alloc_clusters(bs, headerlen); |
| 132 | if (ret < 0) { |
| 133 | error_setg_errno(errp, -ret, |
| 134 | "Cannot allocate cluster for LUKS header size %zu", |
| 135 | headerlen); |
| 136 | return -1; |
| 137 | } |
| 138 | |
| 139 | s->crypto_header.length = headerlen; |
| 140 | s->crypto_header.offset = ret; |
| 141 | |
| 142 | /* |
| 143 | * Zero fill all space in cluster so it has predictable |
| 144 | * content, as we may not initialize some regions of the |
| 145 | * header (eg only 1 out of 8 key slots will be initialized) |
| 146 | */ |
| 147 | clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; |
| 148 | assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); |
| 149 | ret = bdrv_co_pwrite_zeroes(bs->file, ret, clusterlen, 0); |
| 150 | if (ret < 0) { |
| 151 | error_setg_errno(errp, -ret, "Could not zero fill encryption header"); |
| 152 | return -1; |
| 153 | } |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | |
| 159 | /* The graph lock must be held when called in coroutine context */ |
| 160 | static int coroutine_mixed_fn GRAPH_RDLOCK |
| 161 | qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, |
| 162 | const uint8_t *buf, size_t buflen, |
| 163 | void *opaque, Error **errp) |
| 164 | { |
| 165 | BlockDriverState *bs = opaque; |
| 166 | BDRVQcow2State *s = bs->opaque; |
| 167 | ssize_t ret; |
| 168 | |
| 169 | if ((offset + buflen) > s->crypto_header.length) { |
| 170 | error_setg(errp, "Request for data outside of extension header"); |
| 171 | return -1; |
| 172 | } |
| 173 | |
| 174 | ret = bdrv_pwrite(bs->file, s->crypto_header.offset + offset, buflen, buf, |
| 175 | 0); |
| 176 | if (ret < 0) { |
| 177 | error_setg_errno(errp, -ret, "Could not read encryption header"); |
| 178 | return -1; |
| 179 | } |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | static QDict* |
| 184 | qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp) |
| 185 | { |
| 186 | QDict *cryptoopts_qdict; |
| 187 | QDict *opts_qdict; |
| 188 | |
| 189 | /* Extract "encrypt." options into a qdict */ |
| 190 | opts_qdict = qemu_opts_to_qdict(opts, NULL); |
| 191 | qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt."); |
| 192 | qobject_unref(opts_qdict); |
| 193 | qdict_put_str(cryptoopts_qdict, "format", fmt); |
| 194 | return cryptoopts_qdict; |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * read qcow2 extension and fill bs |
| 199 | * start reading from start_offset |
| 200 | * finish reading upon magic of value 0 or when end_offset reached |
| 201 | * unknown magic is skipped (future extension this version knows nothing about) |
| 202 | * return 0 upon success, non-0 otherwise |
| 203 | */ |
| 204 | static int coroutine_fn GRAPH_RDLOCK |
| 205 | qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
| 206 | uint64_t end_offset, void **p_feature_table, |
| 207 | int flags, bool *need_update_header, Error **errp) |
| 208 | { |
| 209 | BDRVQcow2State *s = bs->opaque; |
| 210 | QCowExtension ext; |
| 211 | uint64_t offset; |
| 212 | int ret; |
| 213 | Qcow2BitmapHeaderExt bitmaps_ext; |
| 214 | |
| 215 | if (need_update_header != NULL) { |
| 216 | *need_update_header = false; |
| 217 | } |
| 218 | |
| 219 | #ifdef DEBUG_EXT |
| 220 | printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); |
| 221 | #endif |
| 222 | offset = start_offset; |
| 223 | while (offset < end_offset) { |
| 224 | |
| 225 | #ifdef DEBUG_EXT |
| 226 | /* Sanity check */ |
| 227 | if (offset > s->cluster_size) |
| 228 | printf("qcow2_read_extension: suspicious offset %lu\n", offset); |
| 229 | |
| 230 | printf("attempting to read extended header in offset %lu\n", offset); |
| 231 | #endif |
| 232 | |
| 233 | ret = bdrv_co_pread(bs->file, offset, sizeof(ext), &ext, 0); |
| 234 | if (ret < 0) { |
| 235 | error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " |
| 236 | "pread fail from offset %" PRIu64, offset); |
| 237 | return 1; |
| 238 | } |
| 239 | ext.magic = be32_to_cpu(ext.magic); |
| 240 | ext.len = be32_to_cpu(ext.len); |
| 241 | offset += sizeof(ext); |
| 242 | #ifdef DEBUG_EXT |
| 243 | printf("ext.magic = 0x%x\n", ext.magic); |
| 244 | #endif |
| 245 | if (offset > end_offset || ext.len > end_offset - offset) { |
| 246 | error_setg(errp, "Header extension too large"); |
| 247 | return -EINVAL; |
| 248 | } |
| 249 | |
| 250 | switch (ext.magic) { |
| 251 | case QCOW2_EXT_MAGIC_END: |
| 252 | return 0; |
| 253 | |
| 254 | case QCOW2_EXT_MAGIC_BACKING_FORMAT: |
| 255 | if (ext.len >= sizeof(bs->backing_format)) { |
| 256 | error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 |
| 257 | " too large (>=%zu)", ext.len, |
| 258 | sizeof(bs->backing_format)); |
| 259 | return 2; |
| 260 | } |
| 261 | ret = bdrv_co_pread(bs->file, offset, ext.len, bs->backing_format, 0); |
| 262 | if (ret < 0) { |
| 263 | error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " |
| 264 | "Could not read format name"); |
| 265 | return 3; |
| 266 | } |
| 267 | bs->backing_format[ext.len] = '\0'; |
| 268 | s->image_backing_format = g_strdup(bs->backing_format); |
| 269 | #ifdef DEBUG_EXT |
| 270 | printf("Qcow2: Got format extension %s\n", bs->backing_format); |
| 271 | #endif |
| 272 | break; |
| 273 | |
| 274 | case QCOW2_EXT_MAGIC_FEATURE_TABLE: |
| 275 | if (p_feature_table != NULL) { |
| 276 | void *feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); |
| 277 | ret = bdrv_co_pread(bs->file, offset, ext.len, feature_table, 0); |
| 278 | if (ret < 0) { |
| 279 | error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " |
| 280 | "Could not read table"); |
| 281 | g_free(feature_table); |
| 282 | return ret; |
| 283 | } |
| 284 | |
| 285 | *p_feature_table = feature_table; |
| 286 | } |
| 287 | break; |
| 288 | |
| 289 | case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { |
| 290 | unsigned int cflags = 0; |
| 291 | if (s->crypt_method_header != QCOW_CRYPT_LUKS) { |
| 292 | error_setg(errp, "CRYPTO header extension only " |
| 293 | "expected with LUKS encryption method"); |
| 294 | return -EINVAL; |
| 295 | } |
| 296 | if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { |
| 297 | error_setg(errp, "CRYPTO header extension size %u, " |
| 298 | "but expected size %zu", ext.len, |
| 299 | sizeof(Qcow2CryptoHeaderExtension)); |
| 300 | return -EINVAL; |
| 301 | } |
| 302 | |
| 303 | ret = bdrv_co_pread(bs->file, offset, ext.len, &s->crypto_header, 0); |
| 304 | if (ret < 0) { |
| 305 | error_setg_errno(errp, -ret, |
| 306 | "Unable to read CRYPTO header extension"); |
| 307 | return ret; |
| 308 | } |
| 309 | s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); |
| 310 | s->crypto_header.length = be64_to_cpu(s->crypto_header.length); |
| 311 | |
| 312 | if ((s->crypto_header.offset % s->cluster_size) != 0) { |
| 313 | error_setg(errp, "Encryption header offset '%" PRIu64 "' is " |
| 314 | "not a multiple of cluster size '%u'", |
| 315 | s->crypto_header.offset, s->cluster_size); |
| 316 | return -EINVAL; |
| 317 | } |
| 318 | |
| 319 | if (flags & BDRV_O_NO_IO) { |
| 320 | cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; |
| 321 | } |
| 322 | s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", |
| 323 | qcow2_crypto_hdr_read_func, |
| 324 | bs, cflags, errp); |
| 325 | if (!s->crypto) { |
| 326 | return -EINVAL; |
| 327 | } |
| 328 | } break; |
| 329 | |
| 330 | case QCOW2_EXT_MAGIC_BITMAPS: |
| 331 | if (ext.len != sizeof(bitmaps_ext)) { |
| 332 | error_setg_errno(errp, -ret, "bitmaps_ext: " |
| 333 | "Invalid extension length"); |
| 334 | return -EINVAL; |
| 335 | } |
| 336 | |
| 337 | if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { |
| 338 | if (s->qcow_version < 3) { |
| 339 | /* Let's be a bit more specific */ |
| 340 | warn_report("This qcow2 v2 image contains bitmaps, but " |
| 341 | "they may have been modified by a program " |
| 342 | "without persistent bitmap support; so now " |
| 343 | "they must all be considered inconsistent"); |
| 344 | } else { |
| 345 | warn_report("a program lacking bitmap support " |
| 346 | "modified this file, so all bitmaps are now " |
| 347 | "considered inconsistent"); |
| 348 | } |
| 349 | error_printf("Some clusters may be leaked, " |
| 350 | "run 'qemu-img check -r' on the image " |
| 351 | "file to fix."); |
| 352 | if (need_update_header != NULL) { |
| 353 | /* Updating is needed to drop invalid bitmap extension. */ |
| 354 | *need_update_header = true; |
| 355 | } |
| 356 | break; |
| 357 | } |
| 358 | |
| 359 | ret = bdrv_co_pread(bs->file, offset, ext.len, &bitmaps_ext, 0); |
| 360 | if (ret < 0) { |
| 361 | error_setg_errno(errp, -ret, "bitmaps_ext: " |
| 362 | "Could not read ext header"); |
| 363 | return ret; |
| 364 | } |
| 365 | |
| 366 | if (bitmaps_ext.reserved32 != 0) { |
| 367 | error_setg_errno(errp, -ret, "bitmaps_ext: " |
| 368 | "Reserved field is not zero"); |
| 369 | return -EINVAL; |
| 370 | } |
| 371 | |
| 372 | bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); |
| 373 | bitmaps_ext.bitmap_directory_size = |
| 374 | be64_to_cpu(bitmaps_ext.bitmap_directory_size); |
| 375 | bitmaps_ext.bitmap_directory_offset = |
| 376 | be64_to_cpu(bitmaps_ext.bitmap_directory_offset); |
| 377 | |
| 378 | if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { |
| 379 | error_setg(errp, |
| 380 | "bitmaps_ext: Image has %" PRIu32 " bitmaps, " |
| 381 | "exceeding the QEMU supported maximum of %d", |
| 382 | bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); |
| 383 | return -EINVAL; |
| 384 | } |
| 385 | |
| 386 | if (bitmaps_ext.nb_bitmaps == 0) { |
| 387 | error_setg(errp, "found bitmaps extension with zero bitmaps"); |
| 388 | return -EINVAL; |
| 389 | } |
| 390 | |
| 391 | if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) { |
| 392 | error_setg(errp, "bitmaps_ext: " |
| 393 | "invalid bitmap directory offset"); |
| 394 | return -EINVAL; |
| 395 | } |
| 396 | |
| 397 | if (bitmaps_ext.bitmap_directory_size > |
| 398 | QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
| 399 | error_setg(errp, "bitmaps_ext: " |
| 400 | "bitmap directory size (%" PRIu64 ") exceeds " |
| 401 | "the maximum supported size (%d)", |
| 402 | bitmaps_ext.bitmap_directory_size, |
| 403 | QCOW2_MAX_BITMAP_DIRECTORY_SIZE); |
| 404 | return -EINVAL; |
| 405 | } |
| 406 | |
| 407 | s->nb_bitmaps = bitmaps_ext.nb_bitmaps; |
| 408 | s->bitmap_directory_offset = |
| 409 | bitmaps_ext.bitmap_directory_offset; |
| 410 | s->bitmap_directory_size = |
| 411 | bitmaps_ext.bitmap_directory_size; |
| 412 | |
| 413 | #ifdef DEBUG_EXT |
| 414 | printf("Qcow2: Got bitmaps extension: " |
| 415 | "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", |
| 416 | s->bitmap_directory_offset, s->nb_bitmaps); |
| 417 | #endif |
| 418 | break; |
| 419 | |
| 420 | case QCOW2_EXT_MAGIC_DATA_FILE: |
| 421 | { |
| 422 | s->image_data_file = g_malloc0(ext.len + 1); |
| 423 | ret = bdrv_co_pread(bs->file, offset, ext.len, s->image_data_file, 0); |
| 424 | if (ret < 0) { |
| 425 | error_setg_errno(errp, -ret, |
| 426 | "ERROR: Could not read data file name"); |
| 427 | return ret; |
| 428 | } |
| 429 | #ifdef DEBUG_EXT |
| 430 | printf("Qcow2: Got external data file %s\n", s->image_data_file); |
| 431 | #endif |
| 432 | break; |
| 433 | } |
| 434 | |
| 435 | default: |
| 436 | /* unknown magic - save it in case we need to rewrite the header */ |
| 437 | /* If you add a new feature, make sure to also update the fast |
| 438 | * path of qcow2_make_empty() to deal with it. */ |
| 439 | { |
| 440 | Qcow2UnknownHeaderExtension *uext; |
| 441 | |
| 442 | uext = g_malloc0(sizeof(*uext) + ext.len); |
| 443 | uext->magic = ext.magic; |
| 444 | uext->len = ext.len; |
| 445 | QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); |
| 446 | |
| 447 | ret = bdrv_co_pread(bs->file, offset, uext->len, uext->data, 0); |
| 448 | if (ret < 0) { |
| 449 | error_setg_errno(errp, -ret, "ERROR: unknown extension: " |
| 450 | "Could not read data"); |
| 451 | return ret; |
| 452 | } |
| 453 | } |
| 454 | break; |
| 455 | } |
| 456 | |
| 457 | offset += ((ext.len + 7) & ~7); |
| 458 | } |
| 459 | |
| 460 | return 0; |
| 461 | } |
| 462 | |
| 463 | static void cleanup_unknown_header_ext(BlockDriverState *bs) |
| 464 | { |
| 465 | BDRVQcow2State *s = bs->opaque; |
| 466 | Qcow2UnknownHeaderExtension *uext, *next; |
| 467 | |
| 468 | QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { |
| 469 | QLIST_REMOVE(uext, next); |
| 470 | g_free(uext); |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | static void report_unsupported_feature(Error **errp, Qcow2Feature *table, |
| 475 | uint64_t mask) |
| 476 | { |
| 477 | g_autoptr(GString) features = g_string_sized_new(60); |
| 478 | |
| 479 | while (table && table->name[0] != '\0') { |
| 480 | if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { |
| 481 | if (mask & (1ULL << table->bit)) { |
| 482 | if (features->len > 0) { |
| 483 | g_string_append(features, ", "); |
| 484 | } |
| 485 | g_string_append_printf(features, "%.46s", table->name); |
| 486 | mask &= ~(1ULL << table->bit); |
| 487 | } |
| 488 | } |
| 489 | table++; |
| 490 | } |
| 491 | |
| 492 | if (mask) { |
| 493 | if (features->len > 0) { |
| 494 | g_string_append(features, ", "); |
| 495 | } |
| 496 | g_string_append_printf(features, |
| 497 | "Unknown incompatible feature: %" PRIx64, mask); |
| 498 | } |
| 499 | |
| 500 | error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); |
| 501 | } |
| 502 | |
| 503 | /* |
| 504 | * Sets the dirty bit and flushes afterwards if necessary. |
| 505 | * |
| 506 | * The incompatible_features bit is only set if the image file header was |
| 507 | * updated successfully. Therefore it is not required to check the return |
| 508 | * value of this function. |
| 509 | */ |
| 510 | int qcow2_mark_dirty(BlockDriverState *bs) |
| 511 | { |
| 512 | BDRVQcow2State *s = bs->opaque; |
| 513 | uint64_t val; |
| 514 | int ret; |
| 515 | |
| 516 | assert(s->qcow_version >= 3); |
| 517 | |
| 518 | if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| 519 | return 0; /* already dirty */ |
| 520 | } |
| 521 | |
| 522 | val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); |
| 523 | ret = bdrv_pwrite_sync(bs->file, |
| 524 | offsetof(QCowHeader, incompatible_features), |
| 525 | sizeof(val), &val, 0); |
| 526 | if (ret < 0) { |
| 527 | return ret; |
| 528 | } |
| 529 | |
| 530 | /* Only treat image as dirty if the header was updated successfully */ |
| 531 | s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; |
| 532 | return 0; |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Clears the dirty bit and flushes before if necessary. Only call this |
| 537 | * function when there are no pending requests, it does not guard against |
| 538 | * concurrent requests dirtying the image. |
| 539 | */ |
| 540 | static int GRAPH_RDLOCK qcow2_mark_clean(BlockDriverState *bs) |
| 541 | { |
| 542 | BDRVQcow2State *s = bs->opaque; |
| 543 | |
| 544 | if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| 545 | int ret; |
| 546 | |
| 547 | s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; |
| 548 | |
| 549 | ret = qcow2_flush_caches(bs); |
| 550 | if (ret < 0) { |
| 551 | return ret; |
| 552 | } |
| 553 | |
| 554 | return qcow2_update_header(bs); |
| 555 | } |
| 556 | return 0; |
| 557 | } |
| 558 | |
| 559 | /* |
| 560 | * Marks the image as corrupt. |
| 561 | */ |
| 562 | int qcow2_mark_corrupt(BlockDriverState *bs) |
| 563 | { |
| 564 | BDRVQcow2State *s = bs->opaque; |
| 565 | |
| 566 | s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; |
| 567 | return qcow2_update_header(bs); |
| 568 | } |
| 569 | |
| 570 | /* |
| 571 | * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes |
| 572 | * before if necessary. |
| 573 | */ |
| 574 | static int coroutine_fn GRAPH_RDLOCK |
| 575 | qcow2_mark_consistent(BlockDriverState *bs) |
| 576 | { |
| 577 | BDRVQcow2State *s = bs->opaque; |
| 578 | |
| 579 | if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { |
| 580 | int ret = qcow2_flush_caches(bs); |
| 581 | if (ret < 0) { |
| 582 | return ret; |
| 583 | } |
| 584 | |
| 585 | s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; |
| 586 | return qcow2_update_header(bs); |
| 587 | } |
| 588 | return 0; |
| 589 | } |
| 590 | |
| 591 | static void qcow2_add_check_result(BdrvCheckResult *out, |
| 592 | const BdrvCheckResult *src, |
| 593 | bool set_allocation_info) |
| 594 | { |
| 595 | out->corruptions += src->corruptions; |
| 596 | out->leaks += src->leaks; |
| 597 | out->check_errors += src->check_errors; |
| 598 | out->corruptions_fixed += src->corruptions_fixed; |
| 599 | out->leaks_fixed += src->leaks_fixed; |
| 600 | |
| 601 | if (set_allocation_info) { |
| 602 | out->image_end_offset = src->image_end_offset; |
| 603 | out->bfi = src->bfi; |
| 604 | } |
| 605 | } |
| 606 | |
| 607 | static int coroutine_fn GRAPH_RDLOCK |
| 608 | qcow2_co_check_locked(BlockDriverState *bs, BdrvCheckResult *result, |
| 609 | BdrvCheckMode fix) |
| 610 | { |
| 611 | BdrvCheckResult snapshot_res = {}; |
| 612 | BdrvCheckResult refcount_res = {}; |
| 613 | int ret; |
| 614 | |
| 615 | memset(result, 0, sizeof(*result)); |
| 616 | |
| 617 | ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix); |
| 618 | if (ret < 0) { |
| 619 | qcow2_add_check_result(result, &snapshot_res, false); |
| 620 | return ret; |
| 621 | } |
| 622 | |
| 623 | ret = qcow2_check_refcounts(bs, &refcount_res, fix); |
| 624 | qcow2_add_check_result(result, &refcount_res, true); |
| 625 | if (ret < 0) { |
| 626 | qcow2_add_check_result(result, &snapshot_res, false); |
| 627 | return ret; |
| 628 | } |
| 629 | |
| 630 | ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix); |
| 631 | qcow2_add_check_result(result, &snapshot_res, false); |
| 632 | if (ret < 0) { |
| 633 | return ret; |
| 634 | } |
| 635 | |
| 636 | if (fix && result->check_errors == 0 && result->corruptions == 0) { |
| 637 | ret = qcow2_mark_clean(bs); |
| 638 | if (ret < 0) { |
| 639 | return ret; |
| 640 | } |
| 641 | return qcow2_mark_consistent(bs); |
| 642 | } |
| 643 | return ret; |
| 644 | } |
| 645 | |
| 646 | static int coroutine_fn GRAPH_RDLOCK |
| 647 | qcow2_co_check(BlockDriverState *bs, BdrvCheckResult *result, |
| 648 | BdrvCheckMode fix) |
| 649 | { |
| 650 | BDRVQcow2State *s = bs->opaque; |
| 651 | int ret; |
| 652 | |
| 653 | qemu_co_mutex_lock(&s->lock); |
| 654 | ret = qcow2_co_check_locked(bs, result, fix); |
| 655 | qemu_co_mutex_unlock(&s->lock); |
| 656 | return ret; |
| 657 | } |
| 658 | |
| 659 | int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, |
| 660 | uint64_t entries, size_t entry_len, |
| 661 | int64_t max_size_bytes, const char *table_name, |
| 662 | Error **errp) |
| 663 | { |
| 664 | BDRVQcow2State *s = bs->opaque; |
| 665 | |
| 666 | if (entries > max_size_bytes / entry_len) { |
| 667 | error_setg(errp, "%s too large", table_name); |
| 668 | return -EFBIG; |
| 669 | } |
| 670 | |
| 671 | /* Use signed INT64_MAX as the maximum even for uint64_t header fields, |
| 672 | * because values will be passed to qemu functions taking int64_t. */ |
| 673 | if ((INT64_MAX - entries * entry_len < offset) || |
| 674 | (offset_into_cluster(s, offset) != 0)) { |
| 675 | error_setg(errp, "%s offset invalid", table_name); |
| 676 | return -EINVAL; |
| 677 | } |
| 678 | |
| 679 | return 0; |
| 680 | } |
| 681 | |
| 682 | static const char *const mutable_opts[] = { |
| 683 | QCOW2_OPT_LAZY_REFCOUNTS, |
| 684 | QCOW2_OPT_DISCARD_REQUEST, |
| 685 | QCOW2_OPT_DISCARD_SNAPSHOT, |
| 686 | QCOW2_OPT_DISCARD_OTHER, |
| 687 | QCOW2_OPT_DISCARD_NO_UNREF, |
| 688 | QCOW2_OPT_OVERLAP, |
| 689 | QCOW2_OPT_OVERLAP_TEMPLATE, |
| 690 | QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| 691 | QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| 692 | QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| 693 | QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| 694 | QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| 695 | QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| 696 | QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| 697 | QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| 698 | QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| 699 | QCOW2_OPT_CACHE_SIZE, |
| 700 | QCOW2_OPT_L2_CACHE_SIZE, |
| 701 | QCOW2_OPT_L2_CACHE_ENTRY_SIZE, |
| 702 | QCOW2_OPT_REFCOUNT_CACHE_SIZE, |
| 703 | QCOW2_OPT_CACHE_CLEAN_INTERVAL, |
| 704 | NULL |
| 705 | }; |
| 706 | |
| 707 | static QemuOptsList qcow2_runtime_opts = { |
| 708 | .name = "qcow2", |
| 709 | .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), |
| 710 | .desc = { |
| 711 | { |
| 712 | .name = QCOW2_OPT_LAZY_REFCOUNTS, |
| 713 | .type = QEMU_OPT_BOOL, |
| 714 | .help = "Postpone refcount updates", |
| 715 | }, |
| 716 | { |
| 717 | .name = QCOW2_OPT_DISCARD_REQUEST, |
| 718 | .type = QEMU_OPT_BOOL, |
| 719 | .help = "Pass guest discard requests to the layer below", |
| 720 | }, |
| 721 | { |
| 722 | .name = QCOW2_OPT_DISCARD_SNAPSHOT, |
| 723 | .type = QEMU_OPT_BOOL, |
| 724 | .help = "Generate discard requests when snapshot related space " |
| 725 | "is freed", |
| 726 | }, |
| 727 | { |
| 728 | .name = QCOW2_OPT_DISCARD_OTHER, |
| 729 | .type = QEMU_OPT_BOOL, |
| 730 | .help = "Generate discard requests when other clusters are freed", |
| 731 | }, |
| 732 | { |
| 733 | .name = QCOW2_OPT_DISCARD_NO_UNREF, |
| 734 | .type = QEMU_OPT_BOOL, |
| 735 | .help = "Do not unreference discarded clusters", |
| 736 | }, |
| 737 | { |
| 738 | .name = QCOW2_OPT_OVERLAP, |
| 739 | .type = QEMU_OPT_STRING, |
| 740 | .help = "Selects which overlap checks to perform from a range of " |
| 741 | "templates (none, constant, cached, all)", |
| 742 | }, |
| 743 | { |
| 744 | .name = QCOW2_OPT_OVERLAP_TEMPLATE, |
| 745 | .type = QEMU_OPT_STRING, |
| 746 | .help = "Selects which overlap checks to perform from a range of " |
| 747 | "templates (none, constant, cached, all)", |
| 748 | }, |
| 749 | { |
| 750 | .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| 751 | .type = QEMU_OPT_BOOL, |
| 752 | .help = "Check for unintended writes into the main qcow2 header", |
| 753 | }, |
| 754 | { |
| 755 | .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| 756 | .type = QEMU_OPT_BOOL, |
| 757 | .help = "Check for unintended writes into the active L1 table", |
| 758 | }, |
| 759 | { |
| 760 | .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| 761 | .type = QEMU_OPT_BOOL, |
| 762 | .help = "Check for unintended writes into an active L2 table", |
| 763 | }, |
| 764 | { |
| 765 | .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| 766 | .type = QEMU_OPT_BOOL, |
| 767 | .help = "Check for unintended writes into the refcount table", |
| 768 | }, |
| 769 | { |
| 770 | .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| 771 | .type = QEMU_OPT_BOOL, |
| 772 | .help = "Check for unintended writes into a refcount block", |
| 773 | }, |
| 774 | { |
| 775 | .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| 776 | .type = QEMU_OPT_BOOL, |
| 777 | .help = "Check for unintended writes into the snapshot table", |
| 778 | }, |
| 779 | { |
| 780 | .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| 781 | .type = QEMU_OPT_BOOL, |
| 782 | .help = "Check for unintended writes into an inactive L1 table", |
| 783 | }, |
| 784 | { |
| 785 | .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| 786 | .type = QEMU_OPT_BOOL, |
| 787 | .help = "Check for unintended writes into an inactive L2 table", |
| 788 | }, |
| 789 | { |
| 790 | .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| 791 | .type = QEMU_OPT_BOOL, |
| 792 | .help = "Check for unintended writes into the bitmap directory", |
| 793 | }, |
| 794 | { |
| 795 | .name = QCOW2_OPT_CACHE_SIZE, |
| 796 | .type = QEMU_OPT_SIZE, |
| 797 | .help = "Maximum combined metadata (L2 tables and refcount blocks) " |
| 798 | "cache size", |
| 799 | }, |
| 800 | { |
| 801 | .name = QCOW2_OPT_L2_CACHE_SIZE, |
| 802 | .type = QEMU_OPT_SIZE, |
| 803 | .help = "Maximum L2 table cache size", |
| 804 | }, |
| 805 | { |
| 806 | .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, |
| 807 | .type = QEMU_OPT_SIZE, |
| 808 | .help = "Size of each entry in the L2 cache", |
| 809 | }, |
| 810 | { |
| 811 | .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, |
| 812 | .type = QEMU_OPT_SIZE, |
| 813 | .help = "Maximum refcount block cache size", |
| 814 | }, |
| 815 | { |
| 816 | .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, |
| 817 | .type = QEMU_OPT_NUMBER, |
| 818 | .help = "Clean unused cache entries after this time (in seconds)", |
| 819 | }, |
| 820 | BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", |
| 821 | "ID of secret providing qcow2 AES key or LUKS passphrase"), |
| 822 | { /* end of list */ } |
| 823 | }, |
| 824 | }; |
| 825 | |
| 826 | static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { |
| 827 | [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| 828 | [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| 829 | [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| 830 | [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| 831 | [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| 832 | [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| 833 | [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| 834 | [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| 835 | [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| 836 | }; |
| 837 | |
| 838 | static void coroutine_fn cache_clean_timer(void *opaque) |
| 839 | { |
| 840 | BDRVQcow2State *s = opaque; |
| 841 | uint64_t wait_ns; |
| 842 | |
| 843 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
| 844 | wait_ns = s->cache_clean_interval * NANOSECONDS_PER_SECOND; |
| 845 | } |
| 846 | |
| 847 | while (wait_ns > 0) { |
| 848 | qemu_co_sleep_ns_wakeable(&s->cache_clean_timer_wake, |
| 849 | QEMU_CLOCK_REALTIME, wait_ns); |
| 850 | |
| 851 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
| 852 | if (s->cache_clean_interval > 0) { |
| 853 | qcow2_cache_clean_unused(s->l2_table_cache); |
| 854 | qcow2_cache_clean_unused(s->refcount_block_cache); |
| 855 | } |
| 856 | |
| 857 | wait_ns = s->cache_clean_interval * NANOSECONDS_PER_SECOND; |
| 858 | } |
| 859 | } |
| 860 | |
| 861 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
| 862 | s->cache_clean_timer_co = NULL; |
| 863 | qemu_co_queue_restart_all(&s->cache_clean_timer_exit); |
| 864 | } |
| 865 | } |
| 866 | |
| 867 | static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) |
| 868 | { |
| 869 | BDRVQcow2State *s = bs->opaque; |
| 870 | if (s->cache_clean_interval > 0) { |
| 871 | assert(!s->cache_clean_timer_co); |
| 872 | s->cache_clean_timer_co = qemu_coroutine_create(cache_clean_timer, s); |
| 873 | aio_co_enter(context, s->cache_clean_timer_co); |
| 874 | } |
| 875 | } |
| 876 | |
| 877 | /** |
| 878 | * Delete the cache clean timer and await any yet running instance. |
| 879 | * Called holding s->lock. |
| 880 | */ |
| 881 | static void coroutine_fn |
| 882 | cache_clean_timer_co_locked_del_and_wait(BlockDriverState *bs) |
| 883 | { |
| 884 | BDRVQcow2State *s = bs->opaque; |
| 885 | |
| 886 | if (s->cache_clean_timer_co) { |
| 887 | s->cache_clean_interval = 0; |
| 888 | qemu_co_sleep_wake(&s->cache_clean_timer_wake); |
| 889 | qemu_co_queue_wait(&s->cache_clean_timer_exit, &s->lock); |
| 890 | } |
| 891 | } |
| 892 | |
| 893 | /** |
| 894 | * Same as cache_clean_timer_co_locked_del_and_wait(), but takes s->lock. |
| 895 | */ |
| 896 | static void coroutine_fn |
| 897 | cache_clean_timer_co_del_and_wait(BlockDriverState *bs) |
| 898 | { |
| 899 | BDRVQcow2State *s = bs->opaque; |
| 900 | |
| 901 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
| 902 | cache_clean_timer_co_locked_del_and_wait(bs); |
| 903 | } |
| 904 | } |
| 905 | |
| 906 | struct CacheCleanTimerDelAndWaitCoParams { |
| 907 | BlockDriverState *bs; |
| 908 | bool done; |
| 909 | }; |
| 910 | |
| 911 | static void coroutine_fn cache_clean_timer_del_and_wait_co_entry(void *opaque) |
| 912 | { |
| 913 | struct CacheCleanTimerDelAndWaitCoParams *p = opaque; |
| 914 | |
| 915 | cache_clean_timer_co_del_and_wait(p->bs); |
| 916 | p->done = true; |
| 917 | aio_wait_kick(); |
| 918 | } |
| 919 | |
| 920 | /** |
| 921 | * Delete the cache clean timer and await any yet running instance. |
| 922 | * Must be called from the main or BDS AioContext without s->lock held. |
| 923 | */ |
| 924 | static void coroutine_mixed_fn |
| 925 | cache_clean_timer_del_and_wait(BlockDriverState *bs) |
| 926 | { |
| 927 | IO_OR_GS_CODE(); |
| 928 | |
| 929 | if (qemu_in_coroutine()) { |
| 930 | cache_clean_timer_co_del_and_wait(bs); |
| 931 | } else { |
| 932 | struct CacheCleanTimerDelAndWaitCoParams p = { .bs = bs }; |
| 933 | Coroutine *co; |
| 934 | |
| 935 | co = qemu_coroutine_create(cache_clean_timer_del_and_wait_co_entry, &p); |
| 936 | qemu_coroutine_enter(co); |
| 937 | |
| 938 | BDRV_POLL_WHILE(bs, !p.done); |
| 939 | } |
| 940 | } |
| 941 | |
| 942 | static void qcow2_detach_aio_context(BlockDriverState *bs) |
| 943 | { |
| 944 | cache_clean_timer_del_and_wait(bs); |
| 945 | } |
| 946 | |
| 947 | static void qcow2_attach_aio_context(BlockDriverState *bs, |
| 948 | AioContext *new_context) |
| 949 | { |
| 950 | cache_clean_timer_init(bs, new_context); |
| 951 | } |
| 952 | |
| 953 | static bool read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, |
| 954 | uint64_t *l2_cache_size, |
| 955 | uint64_t *l2_cache_entry_size, |
| 956 | uint64_t *refcount_cache_size, Error **errp) |
| 957 | { |
| 958 | BDRVQcow2State *s = bs->opaque; |
| 959 | uint64_t combined_cache_size, l2_cache_max_setting; |
| 960 | bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; |
| 961 | bool l2_cache_entry_size_set; |
| 962 | int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; |
| 963 | uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
| 964 | uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); |
| 965 | /* An L2 table is always one cluster in size so the max cache size |
| 966 | * should be a multiple of the cluster size. */ |
| 967 | uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s), |
| 968 | s->cluster_size); |
| 969 | |
| 970 | combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); |
| 971 | l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); |
| 972 | refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); |
| 973 | l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); |
| 974 | |
| 975 | combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); |
| 976 | l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, |
| 977 | DEFAULT_L2_CACHE_MAX_SIZE); |
| 978 | *refcount_cache_size = qemu_opt_get_size(opts, |
| 979 | QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); |
| 980 | |
| 981 | *l2_cache_entry_size = qemu_opt_get_size( |
| 982 | opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); |
| 983 | |
| 984 | *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); |
| 985 | |
| 986 | if (combined_cache_size_set) { |
| 987 | if (l2_cache_size_set && refcount_cache_size_set) { |
| 988 | error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE |
| 989 | " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " |
| 990 | "at the same time"); |
| 991 | return false; |
| 992 | } else if (l2_cache_size_set && |
| 993 | (l2_cache_max_setting > combined_cache_size)) { |
| 994 | error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " |
| 995 | QCOW2_OPT_CACHE_SIZE); |
| 996 | return false; |
| 997 | } else if (*refcount_cache_size > combined_cache_size) { |
| 998 | error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " |
| 999 | QCOW2_OPT_CACHE_SIZE); |
| 1000 | return false; |
| 1001 | } |
| 1002 | |
| 1003 | if (l2_cache_size_set) { |
| 1004 | *refcount_cache_size = combined_cache_size - *l2_cache_size; |
| 1005 | } else if (refcount_cache_size_set) { |
| 1006 | *l2_cache_size = combined_cache_size - *refcount_cache_size; |
| 1007 | } else { |
| 1008 | /* Assign as much memory as possible to the L2 cache, and |
| 1009 | * use the remainder for the refcount cache */ |
| 1010 | if (combined_cache_size >= max_l2_cache + min_refcount_cache) { |
| 1011 | *l2_cache_size = max_l2_cache; |
| 1012 | *refcount_cache_size = combined_cache_size - *l2_cache_size; |
| 1013 | } else { |
| 1014 | *refcount_cache_size = |
| 1015 | MIN(combined_cache_size, min_refcount_cache); |
| 1016 | *l2_cache_size = combined_cache_size - *refcount_cache_size; |
| 1017 | } |
| 1018 | } |
| 1019 | } |
| 1020 | |
| 1021 | /* |
| 1022 | * If the L2 cache is not enough to cover the whole disk then |
| 1023 | * default to 4KB entries. Smaller entries reduce the cost of |
| 1024 | * loads and evictions and increase I/O performance. |
| 1025 | */ |
| 1026 | if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { |
| 1027 | *l2_cache_entry_size = MIN(s->cluster_size, 4096); |
| 1028 | } |
| 1029 | |
| 1030 | /* l2_cache_size and refcount_cache_size are ensured to have at least |
| 1031 | * their minimum values in qcow2_update_options_prepare() */ |
| 1032 | |
| 1033 | if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || |
| 1034 | *l2_cache_entry_size > s->cluster_size || |
| 1035 | !is_power_of_2(*l2_cache_entry_size)) { |
| 1036 | error_setg(errp, "L2 cache entry size must be a power of two " |
| 1037 | "between %d and the cluster size (%d)", |
| 1038 | 1 << MIN_CLUSTER_BITS, s->cluster_size); |
| 1039 | return false; |
| 1040 | } |
| 1041 | |
| 1042 | return true; |
| 1043 | } |
| 1044 | |
| 1045 | typedef struct Qcow2ReopenState { |
| 1046 | Qcow2Cache *l2_table_cache; |
| 1047 | Qcow2Cache *refcount_block_cache; |
| 1048 | int l2_slice_size; /* Number of entries in a slice of the L2 table */ |
| 1049 | bool use_lazy_refcounts; |
| 1050 | int overlap_check; |
| 1051 | bool discard_passthrough[QCOW2_DISCARD_MAX]; |
| 1052 | bool discard_no_unref; |
| 1053 | uint64_t cache_clean_interval; |
| 1054 | QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ |
| 1055 | } Qcow2ReopenState; |
| 1056 | |
| 1057 | static int GRAPH_RDLOCK |
| 1058 | qcow2_update_options_prepare(BlockDriverState *bs, Qcow2ReopenState *r, |
| 1059 | QDict *options, int flags, Error **errp) |
| 1060 | { |
| 1061 | BDRVQcow2State *s = bs->opaque; |
| 1062 | QemuOpts *opts = NULL; |
| 1063 | const char *opt_overlap_check, *opt_overlap_check_template; |
| 1064 | int overlap_check_template = 0; |
| 1065 | uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; |
| 1066 | int i; |
| 1067 | const char *encryptfmt; |
| 1068 | QDict *encryptopts = NULL; |
| 1069 | int ret; |
| 1070 | |
| 1071 | qdict_extract_subqdict(options, &encryptopts, "encrypt."); |
| 1072 | encryptfmt = qdict_get_try_str(encryptopts, "format"); |
| 1073 | |
| 1074 | opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort); |
| 1075 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { |
| 1076 | ret = -EINVAL; |
| 1077 | goto fail; |
| 1078 | } |
| 1079 | |
| 1080 | /* get L2 table/refcount block cache size from command line options */ |
| 1081 | if (!read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, |
| 1082 | &refcount_cache_size, errp)) { |
| 1083 | ret = -EINVAL; |
| 1084 | goto fail; |
| 1085 | } |
| 1086 | |
| 1087 | l2_cache_size /= l2_cache_entry_size; |
| 1088 | if (l2_cache_size < MIN_L2_CACHE_SIZE) { |
| 1089 | l2_cache_size = MIN_L2_CACHE_SIZE; |
| 1090 | } |
| 1091 | if (l2_cache_size > INT_MAX) { |
| 1092 | error_setg(errp, "L2 cache size too big"); |
| 1093 | ret = -EINVAL; |
| 1094 | goto fail; |
| 1095 | } |
| 1096 | |
| 1097 | refcount_cache_size /= s->cluster_size; |
| 1098 | if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) { |
| 1099 | refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE; |
| 1100 | } |
| 1101 | if (refcount_cache_size > INT_MAX) { |
| 1102 | error_setg(errp, "Refcount cache size too big"); |
| 1103 | ret = -EINVAL; |
| 1104 | goto fail; |
| 1105 | } |
| 1106 | |
| 1107 | /* alloc new L2 table/refcount block cache, flush old one */ |
| 1108 | if (s->l2_table_cache) { |
| 1109 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
| 1110 | if (ret) { |
| 1111 | error_setg_errno(errp, -ret, "Failed to flush the L2 table cache"); |
| 1112 | goto fail; |
| 1113 | } |
| 1114 | } |
| 1115 | |
| 1116 | if (s->refcount_block_cache) { |
| 1117 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| 1118 | if (ret) { |
| 1119 | error_setg_errno(errp, -ret, |
| 1120 | "Failed to flush the refcount block cache"); |
| 1121 | goto fail; |
| 1122 | } |
| 1123 | } |
| 1124 | |
| 1125 | r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s); |
| 1126 | r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, |
| 1127 | l2_cache_entry_size); |
| 1128 | r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, |
| 1129 | s->cluster_size); |
| 1130 | if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { |
| 1131 | error_setg(errp, "Could not allocate metadata caches"); |
| 1132 | ret = -ENOMEM; |
| 1133 | goto fail; |
| 1134 | } |
| 1135 | |
| 1136 | /* New interval for cache cleanup timer */ |
| 1137 | r->cache_clean_interval = |
| 1138 | qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, |
| 1139 | DEFAULT_CACHE_CLEAN_INTERVAL); |
| 1140 | #ifndef CONFIG_LINUX |
| 1141 | if (r->cache_clean_interval != 0) { |
| 1142 | error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL |
| 1143 | " not supported on this host"); |
| 1144 | ret = -EINVAL; |
| 1145 | goto fail; |
| 1146 | } |
| 1147 | #endif |
| 1148 | if (r->cache_clean_interval > UINT_MAX) { |
| 1149 | error_setg(errp, "Cache clean interval too big"); |
| 1150 | ret = -EINVAL; |
| 1151 | goto fail; |
| 1152 | } |
| 1153 | |
| 1154 | /* lazy-refcounts; flush if going from enabled to disabled */ |
| 1155 | r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, |
| 1156 | (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); |
| 1157 | if (r->use_lazy_refcounts && s->qcow_version < 3) { |
| 1158 | error_setg(errp, "Lazy refcounts require a qcow2 image with at least " |
| 1159 | "qemu 1.1 compatibility level"); |
| 1160 | ret = -EINVAL; |
| 1161 | goto fail; |
| 1162 | } |
| 1163 | |
| 1164 | if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { |
| 1165 | ret = qcow2_mark_clean(bs); |
| 1166 | if (ret < 0) { |
| 1167 | error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); |
| 1168 | goto fail; |
| 1169 | } |
| 1170 | } |
| 1171 | |
| 1172 | /* Overlap check options */ |
| 1173 | opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); |
| 1174 | opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); |
| 1175 | if (opt_overlap_check_template && opt_overlap_check && |
| 1176 | strcmp(opt_overlap_check_template, opt_overlap_check)) |
| 1177 | { |
| 1178 | error_setg(errp, "Conflicting values for qcow2 options '" |
| 1179 | QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE |
| 1180 | "' ('%s')", opt_overlap_check, opt_overlap_check_template); |
| 1181 | ret = -EINVAL; |
| 1182 | goto fail; |
| 1183 | } |
| 1184 | if (!opt_overlap_check) { |
| 1185 | opt_overlap_check = opt_overlap_check_template ?: "cached"; |
| 1186 | } |
| 1187 | |
| 1188 | if (!strcmp(opt_overlap_check, "none")) { |
| 1189 | overlap_check_template = 0; |
| 1190 | } else if (!strcmp(opt_overlap_check, "constant")) { |
| 1191 | overlap_check_template = QCOW2_OL_CONSTANT; |
| 1192 | } else if (!strcmp(opt_overlap_check, "cached")) { |
| 1193 | overlap_check_template = QCOW2_OL_CACHED; |
| 1194 | } else if (!strcmp(opt_overlap_check, "all")) { |
| 1195 | overlap_check_template = QCOW2_OL_ALL; |
| 1196 | } else { |
| 1197 | error_setg(errp, "Unsupported value '%s' for qcow2 option " |
| 1198 | "'overlap-check'. Allowed are any of the following: " |
| 1199 | "none, constant, cached, all", opt_overlap_check); |
| 1200 | ret = -EINVAL; |
| 1201 | goto fail; |
| 1202 | } |
| 1203 | |
| 1204 | r->overlap_check = 0; |
| 1205 | for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { |
| 1206 | /* overlap-check defines a template bitmask, but every flag may be |
| 1207 | * overwritten through the associated boolean option */ |
| 1208 | r->overlap_check |= |
| 1209 | qemu_opt_get_bool(opts, overlap_bool_option_names[i], |
| 1210 | overlap_check_template & (1 << i)) << i; |
| 1211 | } |
| 1212 | |
| 1213 | r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; |
| 1214 | r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; |
| 1215 | r->discard_passthrough[QCOW2_DISCARD_REQUEST] = |
| 1216 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, |
| 1217 | flags & BDRV_O_UNMAP); |
| 1218 | r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = |
| 1219 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); |
| 1220 | r->discard_passthrough[QCOW2_DISCARD_OTHER] = |
| 1221 | qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); |
| 1222 | |
| 1223 | r->discard_no_unref = qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_NO_UNREF, |
| 1224 | false); |
| 1225 | if (r->discard_no_unref && s->qcow_version < 3) { |
| 1226 | error_setg(errp, |
| 1227 | "discard-no-unref is only supported since qcow2 version 3"); |
| 1228 | ret = -EINVAL; |
| 1229 | goto fail; |
| 1230 | } |
| 1231 | |
| 1232 | switch (s->crypt_method_header) { |
| 1233 | case QCOW_CRYPT_NONE: |
| 1234 | if (encryptfmt) { |
| 1235 | error_setg(errp, "No encryption in image header, but options " |
| 1236 | "specified format '%s'", encryptfmt); |
| 1237 | ret = -EINVAL; |
| 1238 | goto fail; |
| 1239 | } |
| 1240 | break; |
| 1241 | |
| 1242 | case QCOW_CRYPT_AES: |
| 1243 | if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { |
| 1244 | error_setg(errp, |
| 1245 | "Header reported 'aes' encryption format but " |
| 1246 | "options specify '%s'", encryptfmt); |
| 1247 | ret = -EINVAL; |
| 1248 | goto fail; |
| 1249 | } |
| 1250 | qdict_put_str(encryptopts, "format", "qcow"); |
| 1251 | r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); |
| 1252 | if (!r->crypto_opts) { |
| 1253 | ret = -EINVAL; |
| 1254 | goto fail; |
| 1255 | } |
| 1256 | break; |
| 1257 | |
| 1258 | case QCOW_CRYPT_LUKS: |
| 1259 | if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { |
| 1260 | error_setg(errp, |
| 1261 | "Header reported 'luks' encryption format but " |
| 1262 | "options specify '%s'", encryptfmt); |
| 1263 | ret = -EINVAL; |
| 1264 | goto fail; |
| 1265 | } |
| 1266 | qdict_put_str(encryptopts, "format", "luks"); |
| 1267 | r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); |
| 1268 | if (!r->crypto_opts) { |
| 1269 | ret = -EINVAL; |
| 1270 | goto fail; |
| 1271 | } |
| 1272 | break; |
| 1273 | |
| 1274 | default: |
| 1275 | error_setg(errp, "Unsupported encryption method %d", |
| 1276 | s->crypt_method_header); |
| 1277 | ret = -EINVAL; |
| 1278 | goto fail; |
| 1279 | } |
| 1280 | |
| 1281 | ret = 0; |
| 1282 | fail: |
| 1283 | qobject_unref(encryptopts); |
| 1284 | qemu_opts_del(opts); |
| 1285 | opts = NULL; |
| 1286 | return ret; |
| 1287 | } |
| 1288 | |
| 1289 | /* s_locked specifies whether s->lock is held or not */ |
| 1290 | static void qcow2_update_options_commit(BlockDriverState *bs, |
| 1291 | Qcow2ReopenState *r, |
| 1292 | bool s_locked) |
| 1293 | { |
| 1294 | BDRVQcow2State *s = bs->opaque; |
| 1295 | int i; |
| 1296 | |
| 1297 | /* |
| 1298 | * We need to stop the cache-clean-timer before destroying the metadata |
| 1299 | * table caches |
| 1300 | */ |
| 1301 | if (s_locked) { |
| 1302 | cache_clean_timer_co_locked_del_and_wait(bs); |
| 1303 | } else { |
| 1304 | cache_clean_timer_del_and_wait(bs); |
| 1305 | } |
| 1306 | |
| 1307 | if (s->l2_table_cache) { |
| 1308 | qcow2_cache_destroy(s->l2_table_cache); |
| 1309 | } |
| 1310 | if (s->refcount_block_cache) { |
| 1311 | qcow2_cache_destroy(s->refcount_block_cache); |
| 1312 | } |
| 1313 | s->l2_table_cache = r->l2_table_cache; |
| 1314 | s->refcount_block_cache = r->refcount_block_cache; |
| 1315 | |
| 1316 | s->l2_slice_size = r->l2_slice_size; |
| 1317 | |
| 1318 | s->overlap_check = r->overlap_check; |
| 1319 | s->use_lazy_refcounts = r->use_lazy_refcounts; |
| 1320 | |
| 1321 | for (i = 0; i < QCOW2_DISCARD_MAX; i++) { |
| 1322 | s->discard_passthrough[i] = r->discard_passthrough[i]; |
| 1323 | } |
| 1324 | |
| 1325 | s->discard_no_unref = r->discard_no_unref; |
| 1326 | |
| 1327 | s->cache_clean_interval = r->cache_clean_interval; |
| 1328 | cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); |
| 1329 | |
| 1330 | qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| 1331 | s->crypto_opts = r->crypto_opts; |
| 1332 | } |
| 1333 | |
| 1334 | static void qcow2_update_options_abort(BlockDriverState *bs, |
| 1335 | Qcow2ReopenState *r) |
| 1336 | { |
| 1337 | if (r->l2_table_cache) { |
| 1338 | qcow2_cache_destroy(r->l2_table_cache); |
| 1339 | } |
| 1340 | if (r->refcount_block_cache) { |
| 1341 | qcow2_cache_destroy(r->refcount_block_cache); |
| 1342 | } |
| 1343 | qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); |
| 1344 | } |
| 1345 | |
| 1346 | /* Called with s->lock held */ |
| 1347 | static int coroutine_fn GRAPH_RDLOCK |
| 1348 | qcow2_update_options(BlockDriverState *bs, QDict *options, int flags, |
| 1349 | Error **errp) |
| 1350 | { |
| 1351 | Qcow2ReopenState r = {}; |
| 1352 | int ret; |
| 1353 | |
| 1354 | ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); |
| 1355 | if (ret >= 0) { |
| 1356 | qcow2_update_options_commit(bs, &r, true); |
| 1357 | } else { |
| 1358 | qcow2_update_options_abort(bs, &r); |
| 1359 | } |
| 1360 | |
| 1361 | return ret; |
| 1362 | } |
| 1363 | |
| 1364 | static int validate_compression_type(BDRVQcow2State *s, Error **errp) |
| 1365 | { |
| 1366 | switch (s->compression_type) { |
| 1367 | case QCOW2_COMPRESSION_TYPE_ZLIB: |
| 1368 | #ifdef CONFIG_ZSTD |
| 1369 | case QCOW2_COMPRESSION_TYPE_ZSTD: |
| 1370 | #endif |
| 1371 | break; |
| 1372 | |
| 1373 | default: |
| 1374 | error_setg(errp, "qcow2: unknown compression type: %u", |
| 1375 | s->compression_type); |
| 1376 | return -ENOTSUP; |
| 1377 | } |
| 1378 | |
| 1379 | /* |
| 1380 | * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB |
| 1381 | * the incompatible feature flag must be set |
| 1382 | */ |
| 1383 | if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) { |
| 1384 | if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) { |
| 1385 | error_setg(errp, "qcow2: Compression type incompatible feature " |
| 1386 | "bit must not be set"); |
| 1387 | return -EINVAL; |
| 1388 | } |
| 1389 | } else { |
| 1390 | if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) { |
| 1391 | error_setg(errp, "qcow2: Compression type incompatible feature " |
| 1392 | "bit must be set"); |
| 1393 | return -EINVAL; |
| 1394 | } |
| 1395 | } |
| 1396 | |
| 1397 | return 0; |
| 1398 | } |
| 1399 | |
| 1400 | /* Called with s->lock held. */ |
| 1401 | static int coroutine_fn GRAPH_RDLOCK |
| 1402 | qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, |
| 1403 | bool open_data_file, Error **errp) |
| 1404 | { |
| 1405 | ERRP_GUARD(); |
| 1406 | BDRVQcow2State *s = bs->opaque; |
| 1407 | unsigned int len, i; |
| 1408 | int ret = 0; |
| 1409 | QCowHeader header; |
| 1410 | uint64_t ext_end; |
| 1411 | uint64_t l1_vm_state_index; |
| 1412 | bool update_header = false; |
| 1413 | |
| 1414 | ret = bdrv_co_pread(bs->file, 0, sizeof(header), &header, 0); |
| 1415 | if (ret < 0) { |
| 1416 | error_setg_errno(errp, -ret, "Could not read qcow2 header"); |
| 1417 | goto fail; |
| 1418 | } |
| 1419 | header.magic = be32_to_cpu(header.magic); |
| 1420 | header.version = be32_to_cpu(header.version); |
| 1421 | header.backing_file_offset = be64_to_cpu(header.backing_file_offset); |
| 1422 | header.backing_file_size = be32_to_cpu(header.backing_file_size); |
| 1423 | header.size = be64_to_cpu(header.size); |
| 1424 | header.cluster_bits = be32_to_cpu(header.cluster_bits); |
| 1425 | header.crypt_method = be32_to_cpu(header.crypt_method); |
| 1426 | header.l1_table_offset = be64_to_cpu(header.l1_table_offset); |
| 1427 | header.l1_size = be32_to_cpu(header.l1_size); |
| 1428 | header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); |
| 1429 | header.refcount_table_clusters = |
| 1430 | be32_to_cpu(header.refcount_table_clusters); |
| 1431 | header.snapshots_offset = be64_to_cpu(header.snapshots_offset); |
| 1432 | header.nb_snapshots = be32_to_cpu(header.nb_snapshots); |
| 1433 | |
| 1434 | if (header.magic != QCOW_MAGIC) { |
| 1435 | error_setg(errp, "Image is not in qcow2 format"); |
| 1436 | ret = -EINVAL; |
| 1437 | goto fail; |
| 1438 | } |
| 1439 | if (header.version < 2 || header.version > 3) { |
| 1440 | error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); |
| 1441 | ret = -ENOTSUP; |
| 1442 | goto fail; |
| 1443 | } |
| 1444 | |
| 1445 | s->qcow_version = header.version; |
| 1446 | |
| 1447 | /* Initialise cluster size */ |
| 1448 | if (header.cluster_bits < MIN_CLUSTER_BITS || |
| 1449 | header.cluster_bits > MAX_CLUSTER_BITS) { |
| 1450 | error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, |
| 1451 | header.cluster_bits); |
| 1452 | ret = -EINVAL; |
| 1453 | goto fail; |
| 1454 | } |
| 1455 | |
| 1456 | s->cluster_bits = header.cluster_bits; |
| 1457 | s->cluster_size = 1 << s->cluster_bits; |
| 1458 | |
| 1459 | /* Initialise version 3 header fields */ |
| 1460 | if (header.version == 2) { |
| 1461 | header.incompatible_features = 0; |
| 1462 | header.compatible_features = 0; |
| 1463 | header.autoclear_features = 0; |
| 1464 | header.refcount_order = 4; |
| 1465 | header.header_length = 72; |
| 1466 | } else { |
| 1467 | header.incompatible_features = |
| 1468 | be64_to_cpu(header.incompatible_features); |
| 1469 | header.compatible_features = be64_to_cpu(header.compatible_features); |
| 1470 | header.autoclear_features = be64_to_cpu(header.autoclear_features); |
| 1471 | header.refcount_order = be32_to_cpu(header.refcount_order); |
| 1472 | header.header_length = be32_to_cpu(header.header_length); |
| 1473 | |
| 1474 | if (header.header_length < 104) { |
| 1475 | error_setg(errp, "qcow2 header too short"); |
| 1476 | ret = -EINVAL; |
| 1477 | goto fail; |
| 1478 | } |
| 1479 | } |
| 1480 | |
| 1481 | if (header.header_length > s->cluster_size) { |
| 1482 | error_setg(errp, "qcow2 header exceeds cluster size"); |
| 1483 | ret = -EINVAL; |
| 1484 | goto fail; |
| 1485 | } |
| 1486 | |
| 1487 | if (header.header_length > sizeof(header)) { |
| 1488 | s->unknown_header_fields_size = header.header_length - sizeof(header); |
| 1489 | s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); |
| 1490 | ret = bdrv_co_pread(bs->file, sizeof(header), |
| 1491 | s->unknown_header_fields_size, |
| 1492 | s->unknown_header_fields, 0); |
| 1493 | if (ret < 0) { |
| 1494 | error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " |
| 1495 | "fields"); |
| 1496 | goto fail; |
| 1497 | } |
| 1498 | } |
| 1499 | |
| 1500 | if (header.backing_file_offset > s->cluster_size) { |
| 1501 | error_setg(errp, "Invalid backing file offset"); |
| 1502 | ret = -EINVAL; |
| 1503 | goto fail; |
| 1504 | } |
| 1505 | |
| 1506 | if (header.backing_file_offset) { |
| 1507 | ext_end = header.backing_file_offset; |
| 1508 | } else { |
| 1509 | ext_end = 1 << header.cluster_bits; |
| 1510 | } |
| 1511 | |
| 1512 | /* Handle feature bits */ |
| 1513 | s->incompatible_features = header.incompatible_features; |
| 1514 | s->compatible_features = header.compatible_features; |
| 1515 | s->autoclear_features = header.autoclear_features; |
| 1516 | |
| 1517 | /* |
| 1518 | * Handle compression type |
| 1519 | * Older qcow2 images don't contain the compression type header. |
| 1520 | * Distinguish them by the header length and use |
| 1521 | * the only valid (default) compression type in that case |
| 1522 | */ |
| 1523 | if (header.header_length > offsetof(QCowHeader, compression_type)) { |
| 1524 | s->compression_type = header.compression_type; |
| 1525 | } else { |
| 1526 | s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; |
| 1527 | } |
| 1528 | |
| 1529 | ret = validate_compression_type(s, errp); |
| 1530 | if (ret) { |
| 1531 | goto fail; |
| 1532 | } |
| 1533 | |
| 1534 | if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) { |
| 1535 | void *feature_table = NULL; |
| 1536 | qcow2_read_extensions(bs, header.header_length, ext_end, |
| 1537 | &feature_table, flags, NULL, NULL); |
| 1538 | report_unsupported_feature(errp, feature_table, |
| 1539 | s->incompatible_features & |
| 1540 | ~QCOW2_INCOMPAT_MASK); |
| 1541 | ret = -ENOTSUP; |
| 1542 | g_free(feature_table); |
| 1543 | goto fail; |
| 1544 | } |
| 1545 | |
| 1546 | if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { |
| 1547 | /* Corrupt images may not be written to unless they are being repaired |
| 1548 | */ |
| 1549 | if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) { |
| 1550 | error_setg(errp, "qcow2: Image is corrupt; cannot be opened " |
| 1551 | "read/write"); |
| 1552 | ret = -EACCES; |
| 1553 | goto fail; |
| 1554 | } |
| 1555 | } |
| 1556 | |
| 1557 | s->subclusters_per_cluster = |
| 1558 | has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1; |
| 1559 | s->subcluster_size = s->cluster_size / s->subclusters_per_cluster; |
| 1560 | s->subcluster_bits = ctz32(s->subcluster_size); |
| 1561 | |
| 1562 | if (s->subcluster_size < (1 << MIN_CLUSTER_BITS)) { |
| 1563 | error_setg(errp, "Unsupported subcluster size: %d", s->subcluster_size); |
| 1564 | ret = -EINVAL; |
| 1565 | goto fail; |
| 1566 | } |
| 1567 | |
| 1568 | /* Check support for various header values */ |
| 1569 | if (header.refcount_order > 6) { |
| 1570 | error_setg(errp, "Reference count entry width too large; may not " |
| 1571 | "exceed 64 bits"); |
| 1572 | ret = -EINVAL; |
| 1573 | goto fail; |
| 1574 | } |
| 1575 | s->refcount_order = header.refcount_order; |
| 1576 | s->refcount_bits = 1 << s->refcount_order; |
| 1577 | s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1); |
| 1578 | s->refcount_max += s->refcount_max - 1; |
| 1579 | |
| 1580 | s->crypt_method_header = header.crypt_method; |
| 1581 | if (s->crypt_method_header) { |
| 1582 | if (bdrv_uses_whitelist() && |
| 1583 | s->crypt_method_header == QCOW_CRYPT_AES) { |
| 1584 | error_setg(errp, |
| 1585 | "Use of AES-CBC encrypted qcow2 images is no longer " |
| 1586 | "supported in system emulators"); |
| 1587 | error_append_hint(errp, |
| 1588 | "You can use 'qemu-img convert' to convert your " |
| 1589 | "image to an alternative supported format, such " |
| 1590 | "as unencrypted qcow2, or raw with the LUKS " |
| 1591 | "format instead.\n"); |
| 1592 | ret = -ENOSYS; |
| 1593 | goto fail; |
| 1594 | } |
| 1595 | |
| 1596 | if (s->crypt_method_header == QCOW_CRYPT_AES) { |
| 1597 | s->crypt_physical_offset = false; |
| 1598 | } else { |
| 1599 | /* Assuming LUKS and any future crypt methods we |
| 1600 | * add will all use physical offsets, due to the |
| 1601 | * fact that the alternative is insecure... */ |
| 1602 | s->crypt_physical_offset = true; |
| 1603 | } |
| 1604 | |
| 1605 | bs->encrypted = true; |
| 1606 | } |
| 1607 | |
| 1608 | s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s)); |
| 1609 | s->l2_size = 1 << s->l2_bits; |
| 1610 | /* 2^(s->refcount_order - 3) is the refcount width in bytes */ |
| 1611 | s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); |
| 1612 | s->refcount_block_size = 1 << s->refcount_block_bits; |
| 1613 | bs->total_sectors = header.size / BDRV_SECTOR_SIZE; |
| 1614 | s->csize_shift = (62 - (s->cluster_bits - 8)); |
| 1615 | s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
| 1616 | s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
| 1617 | |
| 1618 | s->refcount_table_offset = header.refcount_table_offset; |
| 1619 | s->refcount_table_size = |
| 1620 | header.refcount_table_clusters << (s->cluster_bits - 3); |
| 1621 | |
| 1622 | if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { |
| 1623 | error_setg(errp, "Image does not contain a reference count table"); |
| 1624 | ret = -EINVAL; |
| 1625 | goto fail; |
| 1626 | } |
| 1627 | |
| 1628 | ret = qcow2_validate_table(bs, s->refcount_table_offset, |
| 1629 | header.refcount_table_clusters, |
| 1630 | s->cluster_size, QCOW_MAX_REFTABLE_SIZE, |
| 1631 | "Reference count table", errp); |
| 1632 | if (ret < 0) { |
| 1633 | goto fail; |
| 1634 | } |
| 1635 | |
| 1636 | if (!(flags & BDRV_O_CHECK)) { |
| 1637 | /* |
| 1638 | * The total size in bytes of the snapshot table is checked in |
| 1639 | * qcow2_read_snapshots() because the size of each snapshot is |
| 1640 | * variable and we don't know it yet. |
| 1641 | * Here we only check the offset and number of snapshots. |
| 1642 | */ |
| 1643 | ret = qcow2_validate_table(bs, header.snapshots_offset, |
| 1644 | header.nb_snapshots, |
| 1645 | sizeof(QCowSnapshotHeader), |
| 1646 | sizeof(QCowSnapshotHeader) * |
| 1647 | QCOW_MAX_SNAPSHOTS, |
| 1648 | "Snapshot table", errp); |
| 1649 | if (ret < 0) { |
| 1650 | goto fail; |
| 1651 | } |
| 1652 | } |
| 1653 | |
| 1654 | /* read the level 1 table */ |
| 1655 | ret = qcow2_validate_table(bs, header.l1_table_offset, |
| 1656 | header.l1_size, L1E_SIZE, |
| 1657 | QCOW_MAX_L1_SIZE, "Active L1 table", errp); |
| 1658 | if (ret < 0) { |
| 1659 | goto fail; |
| 1660 | } |
| 1661 | s->l1_size = header.l1_size; |
| 1662 | s->l1_table_offset = header.l1_table_offset; |
| 1663 | |
| 1664 | l1_vm_state_index = size_to_l1(s, header.size); |
| 1665 | if (l1_vm_state_index > INT_MAX) { |
| 1666 | error_setg(errp, "Image is too big"); |
| 1667 | ret = -EFBIG; |
| 1668 | goto fail; |
| 1669 | } |
| 1670 | s->l1_vm_state_index = l1_vm_state_index; |
| 1671 | |
| 1672 | /* the L1 table must contain at least enough entries to put |
| 1673 | header.size bytes */ |
| 1674 | if (s->l1_size < s->l1_vm_state_index) { |
| 1675 | error_setg(errp, "L1 table is too small"); |
| 1676 | ret = -EINVAL; |
| 1677 | goto fail; |
| 1678 | } |
| 1679 | |
| 1680 | if (s->l1_size > 0) { |
| 1681 | s->l1_table = qemu_try_blockalign(bs->file->bs, s->l1_size * L1E_SIZE); |
| 1682 | if (s->l1_table == NULL) { |
| 1683 | error_setg(errp, "Could not allocate L1 table"); |
| 1684 | ret = -ENOMEM; |
| 1685 | goto fail; |
| 1686 | } |
| 1687 | ret = bdrv_co_pread(bs->file, s->l1_table_offset, s->l1_size * L1E_SIZE, |
| 1688 | s->l1_table, 0); |
| 1689 | if (ret < 0) { |
| 1690 | error_setg_errno(errp, -ret, "Could not read L1 table"); |
| 1691 | goto fail; |
| 1692 | } |
| 1693 | for(i = 0;i < s->l1_size; i++) { |
| 1694 | s->l1_table[i] = be64_to_cpu(s->l1_table[i]); |
| 1695 | } |
| 1696 | } |
| 1697 | |
| 1698 | /* Parse driver-specific options */ |
| 1699 | ret = qcow2_update_options(bs, options, flags, errp); |
| 1700 | if (ret < 0) { |
| 1701 | goto fail; |
| 1702 | } |
| 1703 | |
| 1704 | s->flags = flags; |
| 1705 | |
| 1706 | ret = qcow2_refcount_init(bs); |
| 1707 | if (ret != 0) { |
| 1708 | error_setg_errno(errp, -ret, "Could not initialize refcount handling"); |
| 1709 | goto fail; |
| 1710 | } |
| 1711 | |
| 1712 | QLIST_INIT(&s->cluster_allocs); |
| 1713 | QTAILQ_INIT(&s->discards); |
| 1714 | |
| 1715 | /* read qcow2 extensions */ |
| 1716 | if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, |
| 1717 | flags, &update_header, errp)) { |
| 1718 | ret = -EINVAL; |
| 1719 | goto fail; |
| 1720 | } |
| 1721 | |
| 1722 | if (open_data_file && (flags & BDRV_O_NO_IO)) { |
| 1723 | /* |
| 1724 | * Don't open the data file for 'qemu-img info' so that it can be used |
| 1725 | * to verify that an untrusted qcow2 image doesn't refer to external |
| 1726 | * files. |
| 1727 | * |
| 1728 | * Note: This still makes has_data_file() return true. |
| 1729 | */ |
| 1730 | if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { |
| 1731 | s->data_file = NULL; |
| 1732 | } else { |
| 1733 | s->data_file = bs->file; |
| 1734 | } |
| 1735 | qdict_extract_subqdict(options, NULL, "data-file."); |
| 1736 | qdict_del(options, "data-file"); |
| 1737 | } else if (open_data_file) { |
| 1738 | /* Open external data file */ |
| 1739 | bdrv_graph_co_rdunlock(); |
| 1740 | s->data_file = bdrv_co_open_child(NULL, options, "data-file", bs, |
| 1741 | &child_of_bds, BDRV_CHILD_DATA, |
| 1742 | true, errp); |
| 1743 | bdrv_graph_co_rdlock(); |
| 1744 | if (*errp) { |
| 1745 | ret = -EINVAL; |
| 1746 | goto fail; |
| 1747 | } |
| 1748 | |
| 1749 | if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { |
| 1750 | if (!s->data_file && s->image_data_file) { |
| 1751 | bdrv_graph_co_rdunlock(); |
| 1752 | s->data_file = bdrv_co_open_child(s->image_data_file, options, |
| 1753 | "data-file", bs, |
| 1754 | &child_of_bds, |
| 1755 | BDRV_CHILD_DATA, false, errp); |
| 1756 | bdrv_graph_co_rdlock(); |
| 1757 | if (!s->data_file) { |
| 1758 | ret = -EINVAL; |
| 1759 | goto fail; |
| 1760 | } |
| 1761 | } |
| 1762 | if (!s->data_file) { |
| 1763 | error_setg(errp, "'data-file' is required for this image"); |
| 1764 | ret = -EINVAL; |
| 1765 | goto fail; |
| 1766 | } |
| 1767 | |
| 1768 | /* No data here */ |
| 1769 | bs->file->role &= ~BDRV_CHILD_DATA; |
| 1770 | |
| 1771 | /* Must succeed because we have given up permissions if anything */ |
| 1772 | bdrv_child_refresh_perms(bs, bs->file, &error_abort); |
| 1773 | } else { |
| 1774 | if (s->data_file) { |
| 1775 | error_setg(errp, "'data-file' can only be set for images with " |
| 1776 | "an external data file"); |
| 1777 | ret = -EINVAL; |
| 1778 | goto fail; |
| 1779 | } |
| 1780 | |
| 1781 | s->data_file = bs->file; |
| 1782 | |
| 1783 | if (data_file_is_raw(bs)) { |
| 1784 | error_setg(errp, "data-file-raw requires a data file"); |
| 1785 | ret = -EINVAL; |
| 1786 | goto fail; |
| 1787 | } |
| 1788 | } |
| 1789 | } |
| 1790 | |
| 1791 | /* qcow2_read_extension may have set up the crypto context |
| 1792 | * if the crypt method needs a header region, some methods |
| 1793 | * don't need header extensions, so must check here |
| 1794 | */ |
| 1795 | if (s->crypt_method_header && !s->crypto) { |
| 1796 | if (s->crypt_method_header == QCOW_CRYPT_AES) { |
| 1797 | unsigned int cflags = 0; |
| 1798 | if (flags & BDRV_O_NO_IO) { |
| 1799 | cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; |
| 1800 | } |
| 1801 | s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", |
| 1802 | NULL, NULL, cflags, errp); |
| 1803 | if (!s->crypto) { |
| 1804 | ret = -EINVAL; |
| 1805 | goto fail; |
| 1806 | } |
| 1807 | } else { |
| 1808 | error_setg(errp, "Missing CRYPTO header for crypt method %d", |
| 1809 | s->crypt_method_header); |
| 1810 | ret = -EINVAL; |
| 1811 | goto fail; |
| 1812 | } |
| 1813 | } |
| 1814 | |
| 1815 | /* read the backing file name */ |
| 1816 | if (header.backing_file_offset != 0) { |
| 1817 | len = header.backing_file_size; |
| 1818 | if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || |
| 1819 | len >= sizeof(bs->backing_file)) { |
| 1820 | error_setg(errp, "Backing file name too long"); |
| 1821 | ret = -EINVAL; |
| 1822 | goto fail; |
| 1823 | } |
| 1824 | |
| 1825 | s->image_backing_file = g_malloc(len + 1); |
| 1826 | ret = bdrv_co_pread(bs->file, header.backing_file_offset, len, |
| 1827 | s->image_backing_file, 0); |
| 1828 | if (ret < 0) { |
| 1829 | error_setg_errno(errp, -ret, "Could not read backing file name"); |
| 1830 | goto fail; |
| 1831 | } |
| 1832 | s->image_backing_file[len] = '\0'; |
| 1833 | |
| 1834 | /* |
| 1835 | * Update only when something has changed. This function is called by |
| 1836 | * qcow2_co_invalidate_cache(), and we do not want to reset |
| 1837 | * auto_backing_file unless necessary. |
| 1838 | */ |
| 1839 | if (!g_str_equal(s->image_backing_file, bs->backing_file)) { |
| 1840 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), |
| 1841 | s->image_backing_file); |
| 1842 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), |
| 1843 | s->image_backing_file); |
| 1844 | } |
| 1845 | } |
| 1846 | |
| 1847 | /* |
| 1848 | * Internal snapshots; skip reading them in check mode, because |
| 1849 | * we do not need them then, and we do not want to abort because |
| 1850 | * of a broken table. |
| 1851 | */ |
| 1852 | if (!(flags & BDRV_O_CHECK)) { |
| 1853 | s->snapshots_offset = header.snapshots_offset; |
| 1854 | s->nb_snapshots = header.nb_snapshots; |
| 1855 | |
| 1856 | ret = qcow2_read_snapshots(bs, errp); |
| 1857 | if (ret < 0) { |
| 1858 | goto fail; |
| 1859 | } |
| 1860 | } |
| 1861 | |
| 1862 | /* Clear unknown autoclear feature bits */ |
| 1863 | update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; |
| 1864 | update_header = update_header && bdrv_is_writable(bs); |
| 1865 | if (update_header) { |
| 1866 | s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; |
| 1867 | } |
| 1868 | |
| 1869 | /* == Handle persistent dirty bitmaps == |
| 1870 | * |
| 1871 | * We want load dirty bitmaps in three cases: |
| 1872 | * |
| 1873 | * 1. Normal open of the disk in active mode, not related to invalidation |
| 1874 | * after migration. |
| 1875 | * |
| 1876 | * 2. Invalidation of the target vm after pre-copy phase of migration, if |
| 1877 | * bitmaps are _not_ migrating through migration channel, i.e. |
| 1878 | * 'dirty-bitmaps' capability is disabled. |
| 1879 | * |
| 1880 | * 3. Invalidation of source vm after failed or canceled migration. |
| 1881 | * This is a very interesting case. There are two possible types of |
| 1882 | * bitmaps: |
| 1883 | * |
| 1884 | * A. Stored on inactivation and removed. They should be loaded from the |
| 1885 | * image. |
| 1886 | * |
| 1887 | * B. Not stored: not-persistent bitmaps and bitmaps, migrated through |
| 1888 | * the migration channel (with dirty-bitmaps capability). |
| 1889 | * |
| 1890 | * On the other hand, there are two possible sub-cases: |
| 1891 | * |
| 1892 | * 3.1 disk was changed by somebody else while were inactive. In this |
| 1893 | * case all in-RAM dirty bitmaps (both persistent and not) are |
| 1894 | * definitely invalid. And we don't have any method to determine |
| 1895 | * this. |
| 1896 | * |
| 1897 | * Simple and safe thing is to just drop all the bitmaps of type B on |
| 1898 | * inactivation. But in this case we lose bitmaps in valid 4.2 case. |
| 1899 | * |
| 1900 | * On the other hand, resuming source vm, if disk was already changed |
| 1901 | * is a bad thing anyway: not only bitmaps, the whole vm state is |
| 1902 | * out of sync with disk. |
| 1903 | * |
| 1904 | * This means, that user or management tool, who for some reason |
| 1905 | * decided to resume source vm, after disk was already changed by |
| 1906 | * target vm, should at least drop all dirty bitmaps by hand. |
| 1907 | * |
| 1908 | * So, we can ignore this case for now, but TODO: "generation" |
| 1909 | * extension for qcow2, to determine, that image was changed after |
| 1910 | * last inactivation. And if it is changed, we will drop (or at least |
| 1911 | * mark as 'invalid' all the bitmaps of type B, both persistent |
| 1912 | * and not). |
| 1913 | * |
| 1914 | * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved |
| 1915 | * to disk ('dirty-bitmaps' capability disabled), or not saved |
| 1916 | * ('dirty-bitmaps' capability enabled), but we don't need to care |
| 1917 | * of: let's load bitmaps as always: stored bitmaps will be loaded, |
| 1918 | * and not stored has flag IN_USE=1 in the image and will be skipped |
| 1919 | * on loading. |
| 1920 | * |
| 1921 | * One remaining possible case when we don't want load bitmaps: |
| 1922 | * |
| 1923 | * 4. Open disk in inactive mode in target vm (bitmaps are migrating or |
| 1924 | * will be loaded on invalidation, no needs try loading them before) |
| 1925 | */ |
| 1926 | |
| 1927 | if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { |
| 1928 | /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ |
| 1929 | bool header_updated; |
| 1930 | if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) { |
| 1931 | ret = -EINVAL; |
| 1932 | goto fail; |
| 1933 | } |
| 1934 | |
| 1935 | update_header = update_header && !header_updated; |
| 1936 | } |
| 1937 | |
| 1938 | if (update_header) { |
| 1939 | ret = qcow2_update_header(bs); |
| 1940 | if (ret < 0) { |
| 1941 | error_setg_errno(errp, -ret, "Could not update qcow2 header"); |
| 1942 | goto fail; |
| 1943 | } |
| 1944 | } |
| 1945 | |
| 1946 | bs->supported_zero_flags = header.version >= 3 ? |
| 1947 | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; |
| 1948 | bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; |
| 1949 | |
| 1950 | /* Repair image if dirty */ |
| 1951 | if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) && |
| 1952 | (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { |
| 1953 | BdrvCheckResult result = {0}; |
| 1954 | |
| 1955 | ret = qcow2_co_check_locked(bs, &result, |
| 1956 | BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); |
| 1957 | if (ret < 0 || result.check_errors) { |
| 1958 | if (ret >= 0) { |
| 1959 | ret = -EIO; |
| 1960 | } |
| 1961 | error_setg_errno(errp, -ret, "Could not repair dirty image"); |
| 1962 | goto fail; |
| 1963 | } |
| 1964 | } |
| 1965 | |
| 1966 | #ifdef DEBUG_ALLOC |
| 1967 | { |
| 1968 | BdrvCheckResult result = {0}; |
| 1969 | qcow2_check_refcounts(bs, &result, 0); |
| 1970 | } |
| 1971 | #endif |
| 1972 | |
| 1973 | qemu_co_queue_init(&s->thread_task_queue); |
| 1974 | |
| 1975 | return ret; |
| 1976 | |
| 1977 | fail: |
| 1978 | g_free(s->image_data_file); |
| 1979 | if (open_data_file && has_data_file(bs)) { |
| 1980 | bdrv_graph_co_rdunlock(); |
| 1981 | bdrv_drain_all_begin(); |
| 1982 | bdrv_co_unref_child(bs, s->data_file); |
| 1983 | bdrv_drain_all_end(); |
| 1984 | bdrv_graph_co_rdlock(); |
| 1985 | s->data_file = NULL; |
| 1986 | } |
| 1987 | g_free(s->unknown_header_fields); |
| 1988 | cleanup_unknown_header_ext(bs); |
| 1989 | qcow2_free_snapshots(bs); |
| 1990 | qcow2_refcount_close(bs); |
| 1991 | qemu_vfree(s->l1_table); |
| 1992 | /* else pre-write overlap checks in cache_destroy may crash */ |
| 1993 | s->l1_table = NULL; |
| 1994 | cache_clean_timer_co_locked_del_and_wait(bs); |
| 1995 | if (s->l2_table_cache) { |
| 1996 | qcow2_cache_destroy(s->l2_table_cache); |
| 1997 | } |
| 1998 | if (s->refcount_block_cache) { |
| 1999 | qcow2_cache_destroy(s->refcount_block_cache); |
| 2000 | } |
| 2001 | qcrypto_block_free(s->crypto); |
| 2002 | qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| 2003 | return ret; |
| 2004 | } |
| 2005 | |
| 2006 | typedef struct QCow2OpenCo { |
| 2007 | BlockDriverState *bs; |
| 2008 | QDict *options; |
| 2009 | int flags; |
| 2010 | Error **errp; |
| 2011 | int ret; |
| 2012 | } QCow2OpenCo; |
| 2013 | |
| 2014 | static void coroutine_fn qcow2_open_entry(void *opaque) |
| 2015 | { |
| 2016 | QCow2OpenCo *qoc = opaque; |
| 2017 | BDRVQcow2State *s = qoc->bs->opaque; |
| 2018 | |
| 2019 | GRAPH_RDLOCK_GUARD(); |
| 2020 | |
| 2021 | qemu_co_mutex_lock(&s->lock); |
| 2022 | qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, true, |
| 2023 | qoc->errp); |
| 2024 | qemu_co_mutex_unlock(&s->lock); |
| 2025 | |
| 2026 | aio_wait_kick(); |
| 2027 | } |
| 2028 | |
| 2029 | static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, |
| 2030 | Error **errp) |
| 2031 | { |
| 2032 | BDRVQcow2State *s = bs->opaque; |
| 2033 | QCow2OpenCo qoc = { |
| 2034 | .bs = bs, |
| 2035 | .options = options, |
| 2036 | .flags = flags, |
| 2037 | .errp = errp, |
| 2038 | .ret = -EINPROGRESS |
| 2039 | }; |
| 2040 | int ret; |
| 2041 | |
| 2042 | ret = bdrv_open_file_child(NULL, options, "file", bs, errp); |
| 2043 | if (ret < 0) { |
| 2044 | return ret; |
| 2045 | } |
| 2046 | |
| 2047 | /* Initialise locks */ |
| 2048 | qemu_co_mutex_init(&s->lock); |
| 2049 | qemu_co_queue_init(&s->cache_clean_timer_exit); |
| 2050 | |
| 2051 | assert(!qemu_in_coroutine()); |
| 2052 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
| 2053 | |
| 2054 | aio_co_enter(bdrv_get_aio_context(bs), |
| 2055 | qemu_coroutine_create(qcow2_open_entry, &qoc)); |
| 2056 | AIO_WAIT_WHILE_UNLOCKED(NULL, qoc.ret == -EINPROGRESS); |
| 2057 | |
| 2058 | return qoc.ret; |
| 2059 | } |
| 2060 | |
| 2061 | static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) |
| 2062 | { |
| 2063 | BDRVQcow2State *s = bs->opaque; |
| 2064 | |
| 2065 | if (s->crypto) { |
| 2066 | /* Encryption works on a sector granularity */ |
| 2067 | bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); |
| 2068 | } |
| 2069 | bs->bl.pwrite_zeroes_alignment = s->subcluster_size; |
| 2070 | bs->bl.pdiscard_alignment = s->cluster_size; |
| 2071 | } |
| 2072 | |
| 2073 | static int GRAPH_UNLOCKED |
| 2074 | qcow2_reopen_prepare(BDRVReopenState *state,BlockReopenQueue *queue, |
| 2075 | Error **errp) |
| 2076 | { |
| 2077 | BDRVQcow2State *s = state->bs->opaque; |
| 2078 | Qcow2ReopenState *r; |
| 2079 | int ret; |
| 2080 | |
| 2081 | GLOBAL_STATE_CODE(); |
| 2082 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 2083 | |
| 2084 | r = g_new0(Qcow2ReopenState, 1); |
| 2085 | state->opaque = r; |
| 2086 | |
| 2087 | ret = qcow2_update_options_prepare(state->bs, r, state->options, |
| 2088 | state->flags, errp); |
| 2089 | if (ret < 0) { |
| 2090 | goto fail; |
| 2091 | } |
| 2092 | |
| 2093 | /* We need to write out any unwritten data if we reopen read-only. */ |
| 2094 | if ((state->flags & BDRV_O_RDWR) == 0) { |
| 2095 | ret = qcow2_reopen_bitmaps_ro(state->bs, errp); |
| 2096 | if (ret < 0) { |
| 2097 | goto fail; |
| 2098 | } |
| 2099 | |
| 2100 | ret = bdrv_flush(state->bs); |
| 2101 | if (ret < 0) { |
| 2102 | goto fail; |
| 2103 | } |
| 2104 | |
| 2105 | ret = qcow2_mark_clean(state->bs); |
| 2106 | if (ret < 0) { |
| 2107 | goto fail; |
| 2108 | } |
| 2109 | } |
| 2110 | |
| 2111 | /* |
| 2112 | * Without an external data file, s->data_file points to the same BdrvChild |
| 2113 | * as bs->file. It needs to be resynced after reopen because bs->file may |
| 2114 | * be changed. We can't use it in the meantime. |
| 2115 | */ |
| 2116 | if (!has_data_file(state->bs)) { |
| 2117 | assert(s->data_file == state->bs->file); |
| 2118 | s->data_file = NULL; |
| 2119 | } |
| 2120 | |
| 2121 | return 0; |
| 2122 | |
| 2123 | fail: |
| 2124 | qcow2_update_options_abort(state->bs, r); |
| 2125 | g_free(r); |
| 2126 | return ret; |
| 2127 | } |
| 2128 | |
| 2129 | static void qcow2_reopen_commit(BDRVReopenState *state) |
| 2130 | { |
| 2131 | BDRVQcow2State *s = state->bs->opaque; |
| 2132 | |
| 2133 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 2134 | |
| 2135 | qcow2_update_options_commit(state->bs, state->opaque, false); |
| 2136 | if (!s->data_file) { |
| 2137 | /* |
| 2138 | * If we don't have an external data file, s->data_file was cleared by |
| 2139 | * qcow2_reopen_prepare() and needs to be updated. |
| 2140 | */ |
| 2141 | s->data_file = state->bs->file; |
| 2142 | } |
| 2143 | g_free(state->opaque); |
| 2144 | } |
| 2145 | |
| 2146 | static void qcow2_reopen_commit_post(BDRVReopenState *state) |
| 2147 | { |
| 2148 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 2149 | |
| 2150 | if (state->flags & BDRV_O_RDWR) { |
| 2151 | Error *local_err = NULL; |
| 2152 | |
| 2153 | if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { |
| 2154 | /* |
| 2155 | * This is not fatal, bitmaps just left read-only, so all following |
| 2156 | * writes will fail. User can remove read-only bitmaps to unblock |
| 2157 | * writes or retry reopen. |
| 2158 | */ |
| 2159 | error_reportf_err(local_err, |
| 2160 | "%s: Failed to make dirty bitmaps writable: ", |
| 2161 | bdrv_get_node_name(state->bs)); |
| 2162 | } |
| 2163 | } |
| 2164 | } |
| 2165 | |
| 2166 | static void qcow2_reopen_abort(BDRVReopenState *state) |
| 2167 | { |
| 2168 | BDRVQcow2State *s = state->bs->opaque; |
| 2169 | |
| 2170 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 2171 | |
| 2172 | if (!s->data_file) { |
| 2173 | /* |
| 2174 | * If we don't have an external data file, s->data_file was cleared by |
| 2175 | * qcow2_reopen_prepare() and needs to be restored. |
| 2176 | */ |
| 2177 | s->data_file = state->bs->file; |
| 2178 | } |
| 2179 | qcow2_update_options_abort(state->bs, state->opaque); |
| 2180 | g_free(state->opaque); |
| 2181 | } |
| 2182 | |
| 2183 | static void qcow2_join_options(QDict *options, QDict *old_options) |
| 2184 | { |
| 2185 | bool has_new_overlap_template = |
| 2186 | qdict_haskey(options, QCOW2_OPT_OVERLAP) || |
| 2187 | qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); |
| 2188 | bool has_new_total_cache_size = |
| 2189 | qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); |
| 2190 | bool has_all_cache_options; |
| 2191 | |
| 2192 | /* New overlap template overrides all old overlap options */ |
| 2193 | if (has_new_overlap_template) { |
| 2194 | qdict_del(old_options, QCOW2_OPT_OVERLAP); |
| 2195 | qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); |
| 2196 | qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); |
| 2197 | qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); |
| 2198 | qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); |
| 2199 | qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); |
| 2200 | qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); |
| 2201 | qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); |
| 2202 | qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); |
| 2203 | qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); |
| 2204 | } |
| 2205 | |
| 2206 | /* New total cache size overrides all old options */ |
| 2207 | if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { |
| 2208 | qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); |
| 2209 | qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); |
| 2210 | } |
| 2211 | |
| 2212 | qdict_join(options, old_options, false); |
| 2213 | |
| 2214 | /* |
| 2215 | * If after merging all cache size options are set, an old total size is |
| 2216 | * overwritten. Do keep all options, however, if all three are new. The |
| 2217 | * resulting error message is what we want to happen. |
| 2218 | */ |
| 2219 | has_all_cache_options = |
| 2220 | qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || |
| 2221 | qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || |
| 2222 | qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); |
| 2223 | |
| 2224 | if (has_all_cache_options && !has_new_total_cache_size) { |
| 2225 | qdict_del(options, QCOW2_OPT_CACHE_SIZE); |
| 2226 | } |
| 2227 | } |
| 2228 | |
| 2229 | static int coroutine_fn GRAPH_RDLOCK |
| 2230 | qcow2_co_block_status(BlockDriverState *bs, unsigned int mode, |
| 2231 | int64_t offset, int64_t count, int64_t *pnum, |
| 2232 | int64_t *map, BlockDriverState **file) |
| 2233 | { |
| 2234 | BDRVQcow2State *s = bs->opaque; |
| 2235 | uint64_t host_offset; |
| 2236 | unsigned int bytes; |
| 2237 | QCow2SubclusterType type; |
| 2238 | int ret, status = 0; |
| 2239 | |
| 2240 | qemu_co_mutex_lock(&s->lock); |
| 2241 | |
| 2242 | if (!s->metadata_preallocation_checked) { |
| 2243 | ret = qcow2_detect_metadata_preallocation(bs); |
| 2244 | s->metadata_preallocation = (ret == 1); |
| 2245 | s->metadata_preallocation_checked = true; |
| 2246 | } |
| 2247 | |
| 2248 | bytes = MIN(INT_MAX, count); |
| 2249 | ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type); |
| 2250 | qemu_co_mutex_unlock(&s->lock); |
| 2251 | if (ret < 0) { |
| 2252 | return ret; |
| 2253 | } |
| 2254 | |
| 2255 | *pnum = bytes; |
| 2256 | |
| 2257 | if ((type == QCOW2_SUBCLUSTER_NORMAL || |
| 2258 | type == QCOW2_SUBCLUSTER_ZERO_ALLOC || |
| 2259 | type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) { |
| 2260 | *map = host_offset; |
| 2261 | *file = s->data_file->bs; |
| 2262 | status |= BDRV_BLOCK_OFFSET_VALID; |
| 2263 | } |
| 2264 | if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || |
| 2265 | type == QCOW2_SUBCLUSTER_ZERO_ALLOC) { |
| 2266 | status |= BDRV_BLOCK_ZERO; |
| 2267 | } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && |
| 2268 | type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) { |
| 2269 | status |= BDRV_BLOCK_DATA; |
| 2270 | } |
| 2271 | if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && |
| 2272 | (status & BDRV_BLOCK_OFFSET_VALID)) |
| 2273 | { |
| 2274 | status |= BDRV_BLOCK_RECURSE; |
| 2275 | } |
| 2276 | if (type == QCOW2_SUBCLUSTER_COMPRESSED) { |
| 2277 | status |= BDRV_BLOCK_COMPRESSED; |
| 2278 | } |
| 2279 | return status; |
| 2280 | } |
| 2281 | |
| 2282 | static int coroutine_fn GRAPH_RDLOCK |
| 2283 | qcow2_handle_l2meta(BlockDriverState *bs, QCowL2Meta **pl2meta, bool link_l2) |
| 2284 | { |
| 2285 | int ret = 0; |
| 2286 | QCowL2Meta *l2meta = *pl2meta; |
| 2287 | |
| 2288 | while (l2meta != NULL) { |
| 2289 | QCowL2Meta *next; |
| 2290 | |
| 2291 | if (link_l2) { |
| 2292 | ret = qcow2_alloc_cluster_link_l2(bs, l2meta); |
| 2293 | if (ret) { |
| 2294 | goto out; |
| 2295 | } |
| 2296 | } else { |
| 2297 | qcow2_alloc_cluster_abort(bs, l2meta); |
| 2298 | } |
| 2299 | |
| 2300 | /* Take the request off the list of running requests */ |
| 2301 | QLIST_REMOVE(l2meta, next_in_flight); |
| 2302 | |
| 2303 | qemu_co_queue_restart_all(&l2meta->dependent_requests); |
| 2304 | |
| 2305 | next = l2meta->next; |
| 2306 | g_free(l2meta); |
| 2307 | l2meta = next; |
| 2308 | } |
| 2309 | out: |
| 2310 | *pl2meta = l2meta; |
| 2311 | return ret; |
| 2312 | } |
| 2313 | |
| 2314 | static int coroutine_fn GRAPH_RDLOCK |
| 2315 | qcow2_co_preadv_encrypted(BlockDriverState *bs, |
| 2316 | uint64_t host_offset, |
| 2317 | uint64_t offset, |
| 2318 | uint64_t bytes, |
| 2319 | QEMUIOVector *qiov, |
| 2320 | uint64_t qiov_offset) |
| 2321 | { |
| 2322 | int ret; |
| 2323 | BDRVQcow2State *s = bs->opaque; |
| 2324 | uint8_t *buf; |
| 2325 | |
| 2326 | assert(bs->encrypted && s->crypto); |
| 2327 | assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| 2328 | |
| 2329 | /* |
| 2330 | * For encrypted images, read everything into a temporary |
| 2331 | * contiguous buffer on which the AES functions can work. |
| 2332 | * Also, decryption in a separate buffer is better as it |
| 2333 | * prevents the guest from learning information about the |
| 2334 | * encrypted nature of the virtual disk. |
| 2335 | */ |
| 2336 | |
| 2337 | buf = qemu_try_blockalign(s->data_file->bs, bytes); |
| 2338 | if (buf == NULL) { |
| 2339 | return -ENOMEM; |
| 2340 | } |
| 2341 | |
| 2342 | BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); |
| 2343 | ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0); |
| 2344 | if (ret < 0) { |
| 2345 | goto fail; |
| 2346 | } |
| 2347 | |
| 2348 | if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0) |
| 2349 | { |
| 2350 | ret = -EIO; |
| 2351 | goto fail; |
| 2352 | } |
| 2353 | qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); |
| 2354 | |
| 2355 | fail: |
| 2356 | qemu_vfree(buf); |
| 2357 | |
| 2358 | return ret; |
| 2359 | } |
| 2360 | |
| 2361 | typedef struct Qcow2AioTask { |
| 2362 | AioTask task; |
| 2363 | |
| 2364 | BlockDriverState *bs; |
| 2365 | QCow2SubclusterType subcluster_type; /* only for read */ |
| 2366 | uint64_t host_offset; /* or l2_entry for compressed read */ |
| 2367 | uint64_t offset; |
| 2368 | uint64_t bytes; |
| 2369 | QEMUIOVector *qiov; |
| 2370 | uint64_t qiov_offset; |
| 2371 | QCowL2Meta *l2meta; /* only for write */ |
| 2372 | } Qcow2AioTask; |
| 2373 | |
| 2374 | static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); |
| 2375 | static coroutine_fn int qcow2_add_task(BlockDriverState *bs, |
| 2376 | AioTaskPool *pool, |
| 2377 | AioTaskFunc func, |
| 2378 | QCow2SubclusterType subcluster_type, |
| 2379 | uint64_t host_offset, |
| 2380 | uint64_t offset, |
| 2381 | uint64_t bytes, |
| 2382 | QEMUIOVector *qiov, |
| 2383 | size_t qiov_offset, |
| 2384 | QCowL2Meta *l2meta) |
| 2385 | { |
| 2386 | Qcow2AioTask local_task; |
| 2387 | Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; |
| 2388 | |
| 2389 | *task = (Qcow2AioTask) { |
| 2390 | .task.func = func, |
| 2391 | .bs = bs, |
| 2392 | .subcluster_type = subcluster_type, |
| 2393 | .qiov = qiov, |
| 2394 | .host_offset = host_offset, |
| 2395 | .offset = offset, |
| 2396 | .bytes = bytes, |
| 2397 | .qiov_offset = qiov_offset, |
| 2398 | .l2meta = l2meta, |
| 2399 | }; |
| 2400 | |
| 2401 | trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, |
| 2402 | func == qcow2_co_preadv_task_entry ? "read" : "write", |
| 2403 | subcluster_type, host_offset, offset, bytes, |
| 2404 | qiov, qiov_offset); |
| 2405 | |
| 2406 | if (!pool) { |
| 2407 | return func(&task->task); |
| 2408 | } |
| 2409 | |
| 2410 | aio_task_pool_start_task(pool, &task->task); |
| 2411 | |
| 2412 | return 0; |
| 2413 | } |
| 2414 | |
| 2415 | static int coroutine_fn GRAPH_RDLOCK |
| 2416 | qcow2_co_preadv_task(BlockDriverState *bs, QCow2SubclusterType subc_type, |
| 2417 | uint64_t host_offset, uint64_t offset, uint64_t bytes, |
| 2418 | QEMUIOVector *qiov, size_t qiov_offset) |
| 2419 | { |
| 2420 | BDRVQcow2State *s = bs->opaque; |
| 2421 | |
| 2422 | switch (subc_type) { |
| 2423 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 2424 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 2425 | /* Both zero types are handled in qcow2_co_preadv_part */ |
| 2426 | g_assert_not_reached(); |
| 2427 | |
| 2428 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
| 2429 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 2430 | assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ |
| 2431 | |
| 2432 | BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
| 2433 | return bdrv_co_preadv_part(bs->backing, offset, bytes, |
| 2434 | qiov, qiov_offset, 0); |
| 2435 | |
| 2436 | case QCOW2_SUBCLUSTER_COMPRESSED: |
| 2437 | return qcow2_co_preadv_compressed(bs, host_offset, |
| 2438 | offset, bytes, qiov, qiov_offset); |
| 2439 | |
| 2440 | case QCOW2_SUBCLUSTER_NORMAL: |
| 2441 | if (bs->encrypted) { |
| 2442 | return qcow2_co_preadv_encrypted(bs, host_offset, |
| 2443 | offset, bytes, qiov, qiov_offset); |
| 2444 | } |
| 2445 | |
| 2446 | BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); |
| 2447 | return bdrv_co_preadv_part(s->data_file, host_offset, |
| 2448 | bytes, qiov, qiov_offset, 0); |
| 2449 | |
| 2450 | default: |
| 2451 | g_assert_not_reached(); |
| 2452 | } |
| 2453 | |
| 2454 | g_assert_not_reached(); |
| 2455 | } |
| 2456 | |
| 2457 | /* |
| 2458 | * This function can count as GRAPH_RDLOCK because qcow2_co_preadv_part() holds |
| 2459 | * the graph lock and keeps it until this coroutine has terminated. |
| 2460 | */ |
| 2461 | static int coroutine_fn GRAPH_RDLOCK qcow2_co_preadv_task_entry(AioTask *task) |
| 2462 | { |
| 2463 | Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); |
| 2464 | |
| 2465 | assert(!t->l2meta); |
| 2466 | |
| 2467 | return qcow2_co_preadv_task(t->bs, t->subcluster_type, |
| 2468 | t->host_offset, t->offset, t->bytes, |
| 2469 | t->qiov, t->qiov_offset); |
| 2470 | } |
| 2471 | |
| 2472 | static int coroutine_fn GRAPH_RDLOCK |
| 2473 | qcow2_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 2474 | QEMUIOVector *qiov, size_t qiov_offset, |
| 2475 | BdrvRequestFlags flags) |
| 2476 | { |
| 2477 | BDRVQcow2State *s = bs->opaque; |
| 2478 | int ret = 0; |
| 2479 | unsigned int cur_bytes; /* number of bytes in current iteration */ |
| 2480 | uint64_t host_offset = 0; |
| 2481 | QCow2SubclusterType type; |
| 2482 | AioTaskPool *aio = NULL; |
| 2483 | |
| 2484 | while (bytes != 0 && aio_task_pool_status(aio) == 0) { |
| 2485 | /* prepare next request */ |
| 2486 | cur_bytes = MIN(bytes, INT_MAX); |
| 2487 | if (s->crypto) { |
| 2488 | cur_bytes = MIN(cur_bytes, |
| 2489 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| 2490 | } |
| 2491 | |
| 2492 | qemu_co_mutex_lock(&s->lock); |
| 2493 | ret = qcow2_get_host_offset(bs, offset, &cur_bytes, |
| 2494 | &host_offset, &type); |
| 2495 | qemu_co_mutex_unlock(&s->lock); |
| 2496 | if (ret < 0) { |
| 2497 | goto out; |
| 2498 | } |
| 2499 | |
| 2500 | if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN || |
| 2501 | type == QCOW2_SUBCLUSTER_ZERO_ALLOC || |
| 2502 | (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) || |
| 2503 | (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing)) |
| 2504 | { |
| 2505 | qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); |
| 2506 | } else { |
| 2507 | if (!aio && cur_bytes != bytes) { |
| 2508 | aio = aio_task_pool_new(QCOW2_MAX_WORKERS); |
| 2509 | } |
| 2510 | ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type, |
| 2511 | host_offset, offset, cur_bytes, |
| 2512 | qiov, qiov_offset, NULL); |
| 2513 | if (ret < 0) { |
| 2514 | goto out; |
| 2515 | } |
| 2516 | } |
| 2517 | |
| 2518 | bytes -= cur_bytes; |
| 2519 | offset += cur_bytes; |
| 2520 | qiov_offset += cur_bytes; |
| 2521 | } |
| 2522 | |
| 2523 | out: |
| 2524 | if (aio) { |
| 2525 | aio_task_pool_wait_all(aio); |
| 2526 | if (ret == 0) { |
| 2527 | ret = aio_task_pool_status(aio); |
| 2528 | } |
| 2529 | g_free(aio); |
| 2530 | } |
| 2531 | |
| 2532 | return ret; |
| 2533 | } |
| 2534 | |
| 2535 | /* Check if it's possible to merge a write request with the writing of |
| 2536 | * the data from the COW regions */ |
| 2537 | static bool merge_cow(uint64_t offset, unsigned bytes, |
| 2538 | QEMUIOVector *qiov, size_t qiov_offset, |
| 2539 | QCowL2Meta *l2meta) |
| 2540 | { |
| 2541 | QCowL2Meta *m; |
| 2542 | |
| 2543 | for (m = l2meta; m != NULL; m = m->next) { |
| 2544 | /* If both COW regions are empty then there's nothing to merge */ |
| 2545 | if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { |
| 2546 | continue; |
| 2547 | } |
| 2548 | |
| 2549 | /* If COW regions are handled already, skip this too */ |
| 2550 | if (m->skip_cow) { |
| 2551 | continue; |
| 2552 | } |
| 2553 | |
| 2554 | /* |
| 2555 | * The write request should start immediately after the first |
| 2556 | * COW region. This does not always happen because the area |
| 2557 | * touched by the request can be larger than the one defined |
| 2558 | * by @m (a single request can span an area consisting of a |
| 2559 | * mix of previously unallocated and allocated clusters, that |
| 2560 | * is why @l2meta is a list). |
| 2561 | */ |
| 2562 | if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { |
| 2563 | /* In this case the request starts before this region */ |
| 2564 | assert(offset < l2meta_cow_start(m)); |
| 2565 | assert(m->cow_start.nb_bytes == 0); |
| 2566 | continue; |
| 2567 | } |
| 2568 | |
| 2569 | /* The write request should end immediately before the second |
| 2570 | * COW region (see above for why it does not always happen) */ |
| 2571 | if (m->offset + m->cow_end.offset != offset + bytes) { |
| 2572 | assert(offset + bytes > m->offset + m->cow_end.offset); |
| 2573 | assert(m->cow_end.nb_bytes == 0); |
| 2574 | continue; |
| 2575 | } |
| 2576 | |
| 2577 | /* Make sure that adding both COW regions to the QEMUIOVector |
| 2578 | * does not exceed IOV_MAX */ |
| 2579 | if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { |
| 2580 | continue; |
| 2581 | } |
| 2582 | |
| 2583 | m->data_qiov = qiov; |
| 2584 | m->data_qiov_offset = qiov_offset; |
| 2585 | return true; |
| 2586 | } |
| 2587 | |
| 2588 | return false; |
| 2589 | } |
| 2590 | |
| 2591 | /* |
| 2592 | * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error. |
| 2593 | * Note that returning 0 does not guarantee non-zero data. |
| 2594 | */ |
| 2595 | static int coroutine_fn GRAPH_RDLOCK |
| 2596 | is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) |
| 2597 | { |
| 2598 | /* |
| 2599 | * This check is designed for optimization shortcut so it must be |
| 2600 | * efficient. |
| 2601 | * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is |
| 2602 | * faster (but not as accurate and can result in false negatives). |
| 2603 | */ |
| 2604 | int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset, |
| 2605 | m->cow_start.nb_bytes); |
| 2606 | if (ret <= 0) { |
| 2607 | return ret; |
| 2608 | } |
| 2609 | |
| 2610 | return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset, |
| 2611 | m->cow_end.nb_bytes); |
| 2612 | } |
| 2613 | |
| 2614 | static int coroutine_fn GRAPH_RDLOCK |
| 2615 | handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) |
| 2616 | { |
| 2617 | BDRVQcow2State *s = bs->opaque; |
| 2618 | QCowL2Meta *m; |
| 2619 | |
| 2620 | if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { |
| 2621 | return 0; |
| 2622 | } |
| 2623 | |
| 2624 | if (bs->encrypted) { |
| 2625 | return 0; |
| 2626 | } |
| 2627 | |
| 2628 | for (m = l2meta; m != NULL; m = m->next) { |
| 2629 | int ret; |
| 2630 | uint64_t start_offset = m->alloc_offset + m->cow_start.offset; |
| 2631 | unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes - |
| 2632 | m->cow_start.offset; |
| 2633 | |
| 2634 | if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { |
| 2635 | continue; |
| 2636 | } |
| 2637 | |
| 2638 | ret = is_zero_cow(bs, m); |
| 2639 | if (ret < 0) { |
| 2640 | return ret; |
| 2641 | } else if (ret == 0) { |
| 2642 | continue; |
| 2643 | } |
| 2644 | |
| 2645 | /* |
| 2646 | * instead of writing zero COW buffers, |
| 2647 | * efficiently zero out the whole clusters |
| 2648 | */ |
| 2649 | |
| 2650 | ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes, |
| 2651 | true); |
| 2652 | if (ret < 0) { |
| 2653 | return ret; |
| 2654 | } |
| 2655 | |
| 2656 | BLKDBG_CO_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); |
| 2657 | ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes, |
| 2658 | BDRV_REQ_NO_FALLBACK); |
| 2659 | if (ret < 0) { |
| 2660 | if (ret != -ENOTSUP && ret != -EAGAIN) { |
| 2661 | return ret; |
| 2662 | } |
| 2663 | continue; |
| 2664 | } |
| 2665 | |
| 2666 | trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); |
| 2667 | m->skip_cow = true; |
| 2668 | } |
| 2669 | return 0; |
| 2670 | } |
| 2671 | |
| 2672 | /* |
| 2673 | * qcow2_co_pwritev_task |
| 2674 | * Called with s->lock unlocked |
| 2675 | * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must |
| 2676 | * not use it somehow after qcow2_co_pwritev_task() call |
| 2677 | */ |
| 2678 | static coroutine_fn GRAPH_RDLOCK |
| 2679 | int qcow2_co_pwritev_task(BlockDriverState *bs, uint64_t host_offset, |
| 2680 | uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, |
| 2681 | uint64_t qiov_offset, QCowL2Meta *l2meta) |
| 2682 | { |
| 2683 | int ret; |
| 2684 | BDRVQcow2State *s = bs->opaque; |
| 2685 | void *crypt_buf = NULL; |
| 2686 | QEMUIOVector encrypted_qiov; |
| 2687 | |
| 2688 | if (bs->encrypted) { |
| 2689 | assert(s->crypto); |
| 2690 | assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| 2691 | crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); |
| 2692 | if (crypt_buf == NULL) { |
| 2693 | ret = -ENOMEM; |
| 2694 | goto out_unlocked; |
| 2695 | } |
| 2696 | qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); |
| 2697 | |
| 2698 | if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) { |
| 2699 | ret = -EIO; |
| 2700 | goto out_unlocked; |
| 2701 | } |
| 2702 | |
| 2703 | qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); |
| 2704 | qiov = &encrypted_qiov; |
| 2705 | qiov_offset = 0; |
| 2706 | } |
| 2707 | |
| 2708 | /* Try to efficiently initialize the physical space with zeroes */ |
| 2709 | ret = handle_alloc_space(bs, l2meta); |
| 2710 | if (ret < 0) { |
| 2711 | goto out_unlocked; |
| 2712 | } |
| 2713 | |
| 2714 | /* |
| 2715 | * If we need to do COW, check if it's possible to merge the |
| 2716 | * writing of the guest data together with that of the COW regions. |
| 2717 | * If it's not possible (or not necessary) then write the |
| 2718 | * guest data now. |
| 2719 | */ |
| 2720 | if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { |
| 2721 | BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); |
| 2722 | trace_qcow2_writev_data(qemu_coroutine_self(), host_offset); |
| 2723 | ret = bdrv_co_pwritev_part(s->data_file, host_offset, |
| 2724 | bytes, qiov, qiov_offset, 0); |
| 2725 | if (ret < 0) { |
| 2726 | goto out_unlocked; |
| 2727 | } |
| 2728 | } |
| 2729 | |
| 2730 | qemu_co_mutex_lock(&s->lock); |
| 2731 | |
| 2732 | ret = qcow2_handle_l2meta(bs, &l2meta, true); |
| 2733 | goto out_locked; |
| 2734 | |
| 2735 | out_unlocked: |
| 2736 | qemu_co_mutex_lock(&s->lock); |
| 2737 | |
| 2738 | out_locked: |
| 2739 | qcow2_handle_l2meta(bs, &l2meta, false); |
| 2740 | qemu_co_mutex_unlock(&s->lock); |
| 2741 | |
| 2742 | qemu_vfree(crypt_buf); |
| 2743 | |
| 2744 | return ret; |
| 2745 | } |
| 2746 | |
| 2747 | /* |
| 2748 | * This function can count as GRAPH_RDLOCK because qcow2_co_pwritev_part() holds |
| 2749 | * the graph lock and keeps it until this coroutine has terminated. |
| 2750 | */ |
| 2751 | static coroutine_fn GRAPH_RDLOCK int qcow2_co_pwritev_task_entry(AioTask *task) |
| 2752 | { |
| 2753 | Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); |
| 2754 | |
| 2755 | assert(!t->subcluster_type); |
| 2756 | |
| 2757 | return qcow2_co_pwritev_task(t->bs, t->host_offset, |
| 2758 | t->offset, t->bytes, t->qiov, t->qiov_offset, |
| 2759 | t->l2meta); |
| 2760 | } |
| 2761 | |
| 2762 | static int coroutine_fn GRAPH_RDLOCK |
| 2763 | qcow2_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 2764 | QEMUIOVector *qiov, size_t qiov_offset, |
| 2765 | BdrvRequestFlags flags) |
| 2766 | { |
| 2767 | BDRVQcow2State *s = bs->opaque; |
| 2768 | int offset_in_cluster; |
| 2769 | int ret; |
| 2770 | unsigned int cur_bytes; /* number of sectors in current iteration */ |
| 2771 | uint64_t host_offset; |
| 2772 | QCowL2Meta *l2meta = NULL; |
| 2773 | AioTaskPool *aio = NULL; |
| 2774 | |
| 2775 | trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); |
| 2776 | |
| 2777 | while (bytes != 0 && aio_task_pool_status(aio) == 0) { |
| 2778 | |
| 2779 | l2meta = NULL; |
| 2780 | |
| 2781 | trace_qcow2_writev_start_part(qemu_coroutine_self()); |
| 2782 | offset_in_cluster = offset_into_cluster(s, offset); |
| 2783 | cur_bytes = MIN(bytes, INT_MAX); |
| 2784 | if (bs->encrypted) { |
| 2785 | cur_bytes = MIN(cur_bytes, |
| 2786 | QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
| 2787 | - offset_in_cluster); |
| 2788 | } |
| 2789 | |
| 2790 | qemu_co_mutex_lock(&s->lock); |
| 2791 | |
| 2792 | ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, |
| 2793 | &host_offset, &l2meta); |
| 2794 | if (ret < 0) { |
| 2795 | goto out_locked; |
| 2796 | } |
| 2797 | |
| 2798 | ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, |
| 2799 | cur_bytes, true); |
| 2800 | if (ret < 0) { |
| 2801 | goto out_locked; |
| 2802 | } |
| 2803 | |
| 2804 | qemu_co_mutex_unlock(&s->lock); |
| 2805 | |
| 2806 | if (!aio && cur_bytes != bytes) { |
| 2807 | aio = aio_task_pool_new(QCOW2_MAX_WORKERS); |
| 2808 | } |
| 2809 | ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, |
| 2810 | host_offset, offset, |
| 2811 | cur_bytes, qiov, qiov_offset, l2meta); |
| 2812 | l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ |
| 2813 | if (ret < 0) { |
| 2814 | goto fail_nometa; |
| 2815 | } |
| 2816 | |
| 2817 | bytes -= cur_bytes; |
| 2818 | offset += cur_bytes; |
| 2819 | qiov_offset += cur_bytes; |
| 2820 | trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); |
| 2821 | } |
| 2822 | ret = 0; |
| 2823 | |
| 2824 | qemu_co_mutex_lock(&s->lock); |
| 2825 | |
| 2826 | out_locked: |
| 2827 | qcow2_handle_l2meta(bs, &l2meta, false); |
| 2828 | |
| 2829 | qemu_co_mutex_unlock(&s->lock); |
| 2830 | |
| 2831 | fail_nometa: |
| 2832 | if (aio) { |
| 2833 | aio_task_pool_wait_all(aio); |
| 2834 | if (ret == 0) { |
| 2835 | ret = aio_task_pool_status(aio); |
| 2836 | } |
| 2837 | g_free(aio); |
| 2838 | } |
| 2839 | |
| 2840 | trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
| 2841 | |
| 2842 | return ret; |
| 2843 | } |
| 2844 | |
| 2845 | static int GRAPH_RDLOCK qcow2_inactivate(BlockDriverState *bs) |
| 2846 | { |
| 2847 | BDRVQcow2State *s = bs->opaque; |
| 2848 | int ret, result = 0; |
| 2849 | Error *local_err = NULL; |
| 2850 | |
| 2851 | qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); |
| 2852 | if (local_err != NULL) { |
| 2853 | result = -EINVAL; |
| 2854 | error_reportf_err(local_err, "Lost persistent bitmaps during " |
| 2855 | "inactivation of node '%s': ", |
| 2856 | bdrv_get_device_or_node_name(bs)); |
| 2857 | } |
| 2858 | |
| 2859 | ret = qcow2_cache_flush(bs, s->l2_table_cache); |
| 2860 | if (ret) { |
| 2861 | result = ret; |
| 2862 | error_report("Failed to flush the L2 table cache: %s", |
| 2863 | strerror(-ret)); |
| 2864 | } |
| 2865 | |
| 2866 | ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| 2867 | if (ret) { |
| 2868 | result = ret; |
| 2869 | error_report("Failed to flush the refcount block cache: %s", |
| 2870 | strerror(-ret)); |
| 2871 | } |
| 2872 | |
| 2873 | /* |
| 2874 | * A read-only node cannot resolve an inherited dirty bit here; |
| 2875 | * leave it dirty, same as plain read access already does. |
| 2876 | */ |
| 2877 | if (result == 0 && !bdrv_is_read_only(bs)) { |
| 2878 | qcow2_mark_clean(bs); |
| 2879 | } |
| 2880 | |
| 2881 | return result; |
| 2882 | } |
| 2883 | |
| 2884 | static void coroutine_mixed_fn GRAPH_RDLOCK |
| 2885 | qcow2_do_close(BlockDriverState *bs, bool close_data_file) |
| 2886 | { |
| 2887 | BDRVQcow2State *s = bs->opaque; |
| 2888 | qemu_vfree(s->l1_table); |
| 2889 | /* else pre-write overlap checks in cache_destroy may crash */ |
| 2890 | s->l1_table = NULL; |
| 2891 | |
| 2892 | if (!(s->flags & BDRV_O_INACTIVE)) { |
| 2893 | qcow2_inactivate(bs); |
| 2894 | } |
| 2895 | |
| 2896 | cache_clean_timer_del_and_wait(bs); |
| 2897 | qcow2_cache_destroy(s->l2_table_cache); |
| 2898 | qcow2_cache_destroy(s->refcount_block_cache); |
| 2899 | |
| 2900 | qcrypto_block_free(s->crypto); |
| 2901 | s->crypto = NULL; |
| 2902 | qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| 2903 | |
| 2904 | g_free(s->unknown_header_fields); |
| 2905 | cleanup_unknown_header_ext(bs); |
| 2906 | |
| 2907 | g_free(s->image_data_file); |
| 2908 | g_free(s->image_backing_file); |
| 2909 | g_free(s->image_backing_format); |
| 2910 | |
| 2911 | if (close_data_file && has_data_file(bs)) { |
| 2912 | GLOBAL_STATE_CODE(); |
| 2913 | bdrv_graph_rdunlock_main_loop(); |
| 2914 | bdrv_graph_wrlock_drained(); |
| 2915 | bdrv_unref_child(bs, s->data_file); |
| 2916 | bdrv_graph_wrunlock(); |
| 2917 | s->data_file = NULL; |
| 2918 | bdrv_graph_rdlock_main_loop(); |
| 2919 | } |
| 2920 | |
| 2921 | qcow2_refcount_close(bs); |
| 2922 | qcow2_free_snapshots(bs); |
| 2923 | } |
| 2924 | |
| 2925 | static void GRAPH_UNLOCKED qcow2_close(BlockDriverState *bs) |
| 2926 | { |
| 2927 | GLOBAL_STATE_CODE(); |
| 2928 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 2929 | |
| 2930 | qcow2_do_close(bs, true); |
| 2931 | } |
| 2932 | |
| 2933 | static void coroutine_fn GRAPH_RDLOCK |
| 2934 | qcow2_co_invalidate_cache(BlockDriverState *bs, Error **errp) |
| 2935 | { |
| 2936 | ERRP_GUARD(); |
| 2937 | BDRVQcow2State *s = bs->opaque; |
| 2938 | BdrvChild *data_file; |
| 2939 | int flags = s->flags; |
| 2940 | QCryptoBlock *crypto = NULL; |
| 2941 | QDict *options; |
| 2942 | int ret; |
| 2943 | |
| 2944 | /* |
| 2945 | * Backing files are read-only which makes all of their metadata immutable, |
| 2946 | * that means we don't have to worry about reopening them here. |
| 2947 | */ |
| 2948 | |
| 2949 | crypto = s->crypto; |
| 2950 | s->crypto = NULL; |
| 2951 | |
| 2952 | /* |
| 2953 | * Do not reopen s->data_file (i.e., have qcow2_do_close() not close it, |
| 2954 | * and then prevent qcow2_do_open() from opening it), because this function |
| 2955 | * runs in the I/O path and as such we must not invoke global-state |
| 2956 | * functions like bdrv_unref_child() and bdrv_open_child(). |
| 2957 | */ |
| 2958 | |
| 2959 | qcow2_do_close(bs, false); |
| 2960 | |
| 2961 | data_file = s->data_file; |
| 2962 | memset(s, 0, sizeof(BDRVQcow2State)); |
| 2963 | s->data_file = data_file; |
| 2964 | /* Re-initialize objects initialized in qcow2_open() */ |
| 2965 | qemu_co_mutex_init(&s->lock); |
| 2966 | qemu_co_queue_init(&s->cache_clean_timer_exit); |
| 2967 | |
| 2968 | options = qdict_clone_shallow(bs->options); |
| 2969 | |
| 2970 | flags &= ~BDRV_O_INACTIVE; |
| 2971 | qemu_co_mutex_lock(&s->lock); |
| 2972 | ret = qcow2_do_open(bs, options, flags, false, errp); |
| 2973 | qemu_co_mutex_unlock(&s->lock); |
| 2974 | qobject_unref(options); |
| 2975 | if (ret < 0) { |
| 2976 | error_prepend(errp, "Could not reopen qcow2 layer: "); |
| 2977 | bs->drv = NULL; |
| 2978 | return; |
| 2979 | } |
| 2980 | |
| 2981 | s->crypto = crypto; |
| 2982 | } |
| 2983 | |
| 2984 | static size_t header_ext_add(char *buf, uint32_t magic, const void *s, |
| 2985 | size_t len, size_t buflen) |
| 2986 | { |
| 2987 | QCowExtension *ext_backing_fmt = (QCowExtension*) buf; |
| 2988 | size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7); |
| 2989 | |
| 2990 | if (buflen < ext_len) { |
| 2991 | return -ENOSPC; |
| 2992 | } |
| 2993 | |
| 2994 | *ext_backing_fmt = (QCowExtension) { |
| 2995 | .magic = cpu_to_be32(magic), |
| 2996 | .len = cpu_to_be32(len), |
| 2997 | }; |
| 2998 | |
| 2999 | if (len) { |
| 3000 | memcpy(buf + sizeof(QCowExtension), s, len); |
| 3001 | } |
| 3002 | |
| 3003 | return ext_len; |
| 3004 | } |
| 3005 | |
| 3006 | /* |
| 3007 | * Updates the qcow2 header, including the variable length parts of it, i.e. |
| 3008 | * the backing file name and all extensions. qcow2 was not designed to allow |
| 3009 | * such changes, so if we run out of space (we can only use the first cluster) |
| 3010 | * this function may fail. |
| 3011 | * |
| 3012 | * Returns 0 on success, -errno in error cases. |
| 3013 | */ |
| 3014 | int qcow2_update_header(BlockDriverState *bs) |
| 3015 | { |
| 3016 | BDRVQcow2State *s = bs->opaque; |
| 3017 | QCowHeader *header; |
| 3018 | char *buf; |
| 3019 | size_t buflen = s->cluster_size; |
| 3020 | int ret; |
| 3021 | uint64_t total_size; |
| 3022 | uint32_t refcount_table_clusters; |
| 3023 | size_t header_length; |
| 3024 | Qcow2UnknownHeaderExtension *uext; |
| 3025 | |
| 3026 | buf = qemu_blockalign(bs, buflen); |
| 3027 | |
| 3028 | /* Header structure */ |
| 3029 | header = (QCowHeader*) buf; |
| 3030 | |
| 3031 | if (buflen < sizeof(*header)) { |
| 3032 | ret = -ENOSPC; |
| 3033 | goto fail; |
| 3034 | } |
| 3035 | |
| 3036 | header_length = sizeof(*header) + s->unknown_header_fields_size; |
| 3037 | total_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
| 3038 | refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); |
| 3039 | |
| 3040 | ret = validate_compression_type(s, NULL); |
| 3041 | if (ret) { |
| 3042 | goto fail; |
| 3043 | } |
| 3044 | |
| 3045 | *header = (QCowHeader) { |
| 3046 | /* Version 2 fields */ |
| 3047 | .magic = cpu_to_be32(QCOW_MAGIC), |
| 3048 | .version = cpu_to_be32(s->qcow_version), |
| 3049 | .backing_file_offset = 0, |
| 3050 | .backing_file_size = 0, |
| 3051 | .cluster_bits = cpu_to_be32(s->cluster_bits), |
| 3052 | .size = cpu_to_be64(total_size), |
| 3053 | .crypt_method = cpu_to_be32(s->crypt_method_header), |
| 3054 | .l1_size = cpu_to_be32(s->l1_size), |
| 3055 | .l1_table_offset = cpu_to_be64(s->l1_table_offset), |
| 3056 | .refcount_table_offset = cpu_to_be64(s->refcount_table_offset), |
| 3057 | .refcount_table_clusters = cpu_to_be32(refcount_table_clusters), |
| 3058 | .nb_snapshots = cpu_to_be32(s->nb_snapshots), |
| 3059 | .snapshots_offset = cpu_to_be64(s->snapshots_offset), |
| 3060 | |
| 3061 | /* Version 3 fields */ |
| 3062 | .incompatible_features = cpu_to_be64(s->incompatible_features), |
| 3063 | .compatible_features = cpu_to_be64(s->compatible_features), |
| 3064 | .autoclear_features = cpu_to_be64(s->autoclear_features), |
| 3065 | .refcount_order = cpu_to_be32(s->refcount_order), |
| 3066 | .header_length = cpu_to_be32(header_length), |
| 3067 | .compression_type = s->compression_type, |
| 3068 | }; |
| 3069 | |
| 3070 | /* For older versions, write a shorter header */ |
| 3071 | switch (s->qcow_version) { |
| 3072 | case 2: |
| 3073 | ret = offsetof(QCowHeader, incompatible_features); |
| 3074 | break; |
| 3075 | case 3: |
| 3076 | ret = sizeof(*header); |
| 3077 | break; |
| 3078 | default: |
| 3079 | ret = -EINVAL; |
| 3080 | goto fail; |
| 3081 | } |
| 3082 | |
| 3083 | buf += ret; |
| 3084 | buflen -= ret; |
| 3085 | memset(buf, 0, buflen); |
| 3086 | |
| 3087 | /* Preserve any unknown field in the header */ |
| 3088 | if (s->unknown_header_fields_size) { |
| 3089 | if (buflen < s->unknown_header_fields_size) { |
| 3090 | ret = -ENOSPC; |
| 3091 | goto fail; |
| 3092 | } |
| 3093 | |
| 3094 | memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size); |
| 3095 | buf += s->unknown_header_fields_size; |
| 3096 | buflen -= s->unknown_header_fields_size; |
| 3097 | } |
| 3098 | |
| 3099 | /* Backing file format header extension */ |
| 3100 | if (s->image_backing_format) { |
| 3101 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, |
| 3102 | s->image_backing_format, |
| 3103 | strlen(s->image_backing_format), |
| 3104 | buflen); |
| 3105 | if (ret < 0) { |
| 3106 | goto fail; |
| 3107 | } |
| 3108 | |
| 3109 | buf += ret; |
| 3110 | buflen -= ret; |
| 3111 | } |
| 3112 | |
| 3113 | /* External data file header extension */ |
| 3114 | if (has_data_file(bs) && s->image_data_file) { |
| 3115 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, |
| 3116 | s->image_data_file, strlen(s->image_data_file), |
| 3117 | buflen); |
| 3118 | if (ret < 0) { |
| 3119 | goto fail; |
| 3120 | } |
| 3121 | |
| 3122 | buf += ret; |
| 3123 | buflen -= ret; |
| 3124 | } |
| 3125 | |
| 3126 | /* Full disk encryption header pointer extension */ |
| 3127 | if (s->crypto_header.offset != 0) { |
| 3128 | s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); |
| 3129 | s->crypto_header.length = cpu_to_be64(s->crypto_header.length); |
| 3130 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, |
| 3131 | &s->crypto_header, sizeof(s->crypto_header), |
| 3132 | buflen); |
| 3133 | s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); |
| 3134 | s->crypto_header.length = be64_to_cpu(s->crypto_header.length); |
| 3135 | if (ret < 0) { |
| 3136 | goto fail; |
| 3137 | } |
| 3138 | buf += ret; |
| 3139 | buflen -= ret; |
| 3140 | } |
| 3141 | |
| 3142 | /* |
| 3143 | * Feature table. A mere 8 feature names occupies 392 bytes, and |
| 3144 | * when coupled with the v3 minimum header of 104 bytes plus the |
| 3145 | * 8-byte end-of-extension marker, that would leave only 8 bytes |
| 3146 | * for a backing file name in an image with 512-byte clusters. |
| 3147 | * Thus, we choose to omit this header for cluster sizes 4k and |
| 3148 | * smaller. |
| 3149 | */ |
| 3150 | if (s->qcow_version >= 3 && s->cluster_size > 4096) { |
| 3151 | static const Qcow2Feature features[] = { |
| 3152 | { |
| 3153 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| 3154 | .bit = QCOW2_INCOMPAT_DIRTY_BITNR, |
| 3155 | .name = "dirty bit", |
| 3156 | }, |
| 3157 | { |
| 3158 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| 3159 | .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, |
| 3160 | .name = "corrupt bit", |
| 3161 | }, |
| 3162 | { |
| 3163 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| 3164 | .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, |
| 3165 | .name = "external data file", |
| 3166 | }, |
| 3167 | { |
| 3168 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| 3169 | .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, |
| 3170 | .name = "compression type", |
| 3171 | }, |
| 3172 | { |
| 3173 | .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| 3174 | .bit = QCOW2_INCOMPAT_EXTL2_BITNR, |
| 3175 | .name = "extended L2 entries", |
| 3176 | }, |
| 3177 | { |
| 3178 | .type = QCOW2_FEAT_TYPE_COMPATIBLE, |
| 3179 | .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, |
| 3180 | .name = "lazy refcounts", |
| 3181 | }, |
| 3182 | { |
| 3183 | .type = QCOW2_FEAT_TYPE_AUTOCLEAR, |
| 3184 | .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, |
| 3185 | .name = "bitmaps", |
| 3186 | }, |
| 3187 | { |
| 3188 | .type = QCOW2_FEAT_TYPE_AUTOCLEAR, |
| 3189 | .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, |
| 3190 | .name = "raw external data", |
| 3191 | }, |
| 3192 | }; |
| 3193 | |
| 3194 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, |
| 3195 | features, sizeof(features), buflen); |
| 3196 | if (ret < 0) { |
| 3197 | goto fail; |
| 3198 | } |
| 3199 | buf += ret; |
| 3200 | buflen -= ret; |
| 3201 | } |
| 3202 | |
| 3203 | /* Bitmap extension */ |
| 3204 | if (s->nb_bitmaps > 0) { |
| 3205 | Qcow2BitmapHeaderExt bitmaps_header = { |
| 3206 | .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), |
| 3207 | .bitmap_directory_size = |
| 3208 | cpu_to_be64(s->bitmap_directory_size), |
| 3209 | .bitmap_directory_offset = |
| 3210 | cpu_to_be64(s->bitmap_directory_offset) |
| 3211 | }; |
| 3212 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, |
| 3213 | &bitmaps_header, sizeof(bitmaps_header), |
| 3214 | buflen); |
| 3215 | if (ret < 0) { |
| 3216 | goto fail; |
| 3217 | } |
| 3218 | buf += ret; |
| 3219 | buflen -= ret; |
| 3220 | } |
| 3221 | |
| 3222 | /* Keep unknown header extensions */ |
| 3223 | QLIST_FOREACH(uext, &s->unknown_header_ext, next) { |
| 3224 | ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); |
| 3225 | if (ret < 0) { |
| 3226 | goto fail; |
| 3227 | } |
| 3228 | |
| 3229 | buf += ret; |
| 3230 | buflen -= ret; |
| 3231 | } |
| 3232 | |
| 3233 | /* End of header extensions */ |
| 3234 | ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); |
| 3235 | if (ret < 0) { |
| 3236 | goto fail; |
| 3237 | } |
| 3238 | |
| 3239 | buf += ret; |
| 3240 | buflen -= ret; |
| 3241 | |
| 3242 | /* Backing file name */ |
| 3243 | if (s->image_backing_file) { |
| 3244 | size_t backing_file_len = strlen(s->image_backing_file); |
| 3245 | |
| 3246 | if (buflen < backing_file_len) { |
| 3247 | ret = -ENOSPC; |
| 3248 | goto fail; |
| 3249 | } |
| 3250 | |
| 3251 | /* Using strncpy is ok here, since buf is not NUL-terminated. */ |
| 3252 | strncpy(buf, s->image_backing_file, buflen); |
| 3253 | |
| 3254 | header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); |
| 3255 | header->backing_file_size = cpu_to_be32(backing_file_len); |
| 3256 | } |
| 3257 | |
| 3258 | /* Write the new header */ |
| 3259 | ret = bdrv_pwrite(bs->file, 0, s->cluster_size, header, 0); |
| 3260 | if (ret < 0) { |
| 3261 | goto fail; |
| 3262 | } |
| 3263 | |
| 3264 | ret = 0; |
| 3265 | fail: |
| 3266 | qemu_vfree(header); |
| 3267 | return ret; |
| 3268 | } |
| 3269 | |
| 3270 | static int coroutine_fn GRAPH_RDLOCK |
| 3271 | qcow2_co_change_backing_file(BlockDriverState *bs, const char *backing_file, |
| 3272 | const char *backing_fmt) |
| 3273 | { |
| 3274 | BDRVQcow2State *s = bs->opaque; |
| 3275 | |
| 3276 | /* Adding a backing file means that the external data file alone won't be |
| 3277 | * enough to make sense of the content */ |
| 3278 | if (backing_file && data_file_is_raw(bs)) { |
| 3279 | return -EINVAL; |
| 3280 | } |
| 3281 | |
| 3282 | if (backing_file && strlen(backing_file) > 1023) { |
| 3283 | return -EINVAL; |
| 3284 | } |
| 3285 | |
| 3286 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), |
| 3287 | backing_file ?: ""); |
| 3288 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
| 3289 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
| 3290 | |
| 3291 | g_free(s->image_backing_file); |
| 3292 | g_free(s->image_backing_format); |
| 3293 | |
| 3294 | s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; |
| 3295 | s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; |
| 3296 | |
| 3297 | return qcow2_update_header(bs); |
| 3298 | } |
| 3299 | |
| 3300 | static int coroutine_fn GRAPH_RDLOCK |
| 3301 | qcow2_set_up_encryption(BlockDriverState *bs, |
| 3302 | QCryptoBlockCreateOptions *cryptoopts, |
| 3303 | Error **errp) |
| 3304 | { |
| 3305 | BDRVQcow2State *s = bs->opaque; |
| 3306 | QCryptoBlock *crypto = NULL; |
| 3307 | int fmt, ret; |
| 3308 | |
| 3309 | switch (cryptoopts->format) { |
| 3310 | case QCRYPTO_BLOCK_FORMAT_LUKS: |
| 3311 | fmt = QCOW_CRYPT_LUKS; |
| 3312 | break; |
| 3313 | case QCRYPTO_BLOCK_FORMAT_QCOW: |
| 3314 | fmt = QCOW_CRYPT_AES; |
| 3315 | break; |
| 3316 | default: |
| 3317 | error_setg(errp, "Crypto format not supported in qcow2"); |
| 3318 | return -EINVAL; |
| 3319 | } |
| 3320 | |
| 3321 | s->crypt_method_header = fmt; |
| 3322 | |
| 3323 | crypto = qcrypto_block_create(cryptoopts, "encrypt.", |
| 3324 | qcow2_crypto_hdr_init_func, |
| 3325 | qcow2_crypto_hdr_write_func, |
| 3326 | bs, 0, errp); |
| 3327 | if (!crypto) { |
| 3328 | return -EINVAL; |
| 3329 | } |
| 3330 | |
| 3331 | ret = qcow2_update_header(bs); |
| 3332 | if (ret < 0) { |
| 3333 | error_setg_errno(errp, -ret, "Could not write encryption header"); |
| 3334 | goto out; |
| 3335 | } |
| 3336 | |
| 3337 | ret = 0; |
| 3338 | out: |
| 3339 | qcrypto_block_free(crypto); |
| 3340 | return ret; |
| 3341 | } |
| 3342 | |
| 3343 | /** |
| 3344 | * Preallocates metadata structures for data clusters between @offset (in the |
| 3345 | * guest disk) and @new_length (which is thus generally the new guest disk |
| 3346 | * size). |
| 3347 | * |
| 3348 | * Returns: 0 on success, -errno on failure. |
| 3349 | */ |
| 3350 | static int coroutine_fn GRAPH_RDLOCK |
| 3351 | preallocate_co(BlockDriverState *bs, uint64_t offset, uint64_t new_length, |
| 3352 | PreallocMode mode, Error **errp) |
| 3353 | { |
| 3354 | BDRVQcow2State *s = bs->opaque; |
| 3355 | uint64_t bytes; |
| 3356 | uint64_t host_offset = 0; |
| 3357 | int64_t file_length; |
| 3358 | unsigned int cur_bytes; |
| 3359 | int ret; |
| 3360 | QCowL2Meta *meta = NULL, *m; |
| 3361 | |
| 3362 | assert(offset <= new_length); |
| 3363 | bytes = new_length - offset; |
| 3364 | |
| 3365 | while (bytes) { |
| 3366 | cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size)); |
| 3367 | ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes, |
| 3368 | &host_offset, &meta); |
| 3369 | if (ret < 0) { |
| 3370 | error_setg_errno(errp, -ret, "Allocating clusters failed"); |
| 3371 | goto out; |
| 3372 | } |
| 3373 | |
| 3374 | for (m = meta; m != NULL; m = m->next) { |
| 3375 | m->prealloc = true; |
| 3376 | } |
| 3377 | |
| 3378 | ret = qcow2_handle_l2meta(bs, &meta, true); |
| 3379 | if (ret < 0) { |
| 3380 | error_setg_errno(errp, -ret, "Mapping clusters failed"); |
| 3381 | goto out; |
| 3382 | } |
| 3383 | |
| 3384 | /* TODO Preallocate data if requested */ |
| 3385 | |
| 3386 | bytes -= cur_bytes; |
| 3387 | offset += cur_bytes; |
| 3388 | } |
| 3389 | |
| 3390 | /* |
| 3391 | * It is expected that the image file is large enough to actually contain |
| 3392 | * all of the allocated clusters (otherwise we get failing reads after |
| 3393 | * EOF). Extend the image to the last allocated sector. |
| 3394 | */ |
| 3395 | file_length = bdrv_co_getlength(s->data_file->bs); |
| 3396 | if (file_length < 0) { |
| 3397 | error_setg_errno(errp, -file_length, "Could not get file size"); |
| 3398 | ret = file_length; |
| 3399 | goto out; |
| 3400 | } |
| 3401 | |
| 3402 | if (host_offset + cur_bytes > file_length) { |
| 3403 | if (mode == PREALLOC_MODE_METADATA) { |
| 3404 | mode = PREALLOC_MODE_OFF; |
| 3405 | } |
| 3406 | ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false, |
| 3407 | mode, 0, errp); |
| 3408 | if (ret < 0) { |
| 3409 | goto out; |
| 3410 | } |
| 3411 | } |
| 3412 | |
| 3413 | ret = 0; |
| 3414 | |
| 3415 | out: |
| 3416 | qcow2_handle_l2meta(bs, &meta, false); |
| 3417 | return ret; |
| 3418 | } |
| 3419 | |
| 3420 | /* qcow2_refcount_metadata_size: |
| 3421 | * @clusters: number of clusters to refcount (including data and L1/L2 tables) |
| 3422 | * @cluster_size: size of a cluster, in bytes |
| 3423 | * @refcount_order: refcount bits power-of-2 exponent |
| 3424 | * @generous_increase: allow for the refcount table to be 1.5x as large as it |
| 3425 | * needs to be |
| 3426 | * |
| 3427 | * Returns: Number of bytes required for refcount blocks and table metadata. |
| 3428 | */ |
| 3429 | int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, |
| 3430 | int refcount_order, bool generous_increase, |
| 3431 | uint64_t *refblock_count) |
| 3432 | { |
| 3433 | /* |
| 3434 | * Every host cluster is reference-counted, including metadata (even |
| 3435 | * refcount metadata is recursively included). |
| 3436 | * |
| 3437 | * An accurate formula for the size of refcount metadata size is difficult |
| 3438 | * to derive. An easier method of calculation is finding the fixed point |
| 3439 | * where no further refcount blocks or table clusters are required to |
| 3440 | * reference count every cluster. |
| 3441 | */ |
| 3442 | int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE; |
| 3443 | int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order); |
| 3444 | int64_t table = 0; /* number of refcount table clusters */ |
| 3445 | int64_t blocks = 0; /* number of refcount block clusters */ |
| 3446 | int64_t last; |
| 3447 | int64_t n = 0; |
| 3448 | |
| 3449 | do { |
| 3450 | last = n; |
| 3451 | blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block); |
| 3452 | table = DIV_ROUND_UP(blocks, blocks_per_table_cluster); |
| 3453 | n = clusters + blocks + table; |
| 3454 | |
| 3455 | if (n == last && generous_increase) { |
| 3456 | clusters += DIV_ROUND_UP(table, 2); |
| 3457 | n = 0; /* force another loop */ |
| 3458 | generous_increase = false; |
| 3459 | } |
| 3460 | } while (n != last); |
| 3461 | |
| 3462 | if (refblock_count) { |
| 3463 | *refblock_count = blocks; |
| 3464 | } |
| 3465 | |
| 3466 | return (blocks + table) * cluster_size; |
| 3467 | } |
| 3468 | |
| 3469 | /** |
| 3470 | * qcow2_calc_prealloc_size: |
| 3471 | * @total_size: virtual disk size in bytes |
| 3472 | * @cluster_size: cluster size in bytes |
| 3473 | * @refcount_order: refcount bits power-of-2 exponent |
| 3474 | * @extended_l2: true if the image has extended L2 entries |
| 3475 | * |
| 3476 | * Returns: Total number of bytes required for the fully allocated image |
| 3477 | * (including metadata). |
| 3478 | */ |
| 3479 | static int64_t qcow2_calc_prealloc_size(int64_t total_size, |
| 3480 | size_t cluster_size, |
| 3481 | int refcount_order, |
| 3482 | bool extended_l2) |
| 3483 | { |
| 3484 | int64_t meta_size = 0; |
| 3485 | uint64_t nl1e, nl2e; |
| 3486 | int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); |
| 3487 | size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; |
| 3488 | |
| 3489 | /* header: 1 cluster */ |
| 3490 | meta_size += cluster_size; |
| 3491 | |
| 3492 | /* total size of L2 tables */ |
| 3493 | nl2e = aligned_total_size / cluster_size; |
| 3494 | nl2e = ROUND_UP(nl2e, cluster_size / l2e_size); |
| 3495 | meta_size += nl2e * l2e_size; |
| 3496 | |
| 3497 | /* total size of L1 tables */ |
| 3498 | nl1e = nl2e * l2e_size / cluster_size; |
| 3499 | nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE); |
| 3500 | meta_size += nl1e * L1E_SIZE; |
| 3501 | |
| 3502 | /* total size of refcount table and blocks */ |
| 3503 | meta_size += qcow2_refcount_metadata_size( |
| 3504 | (meta_size + aligned_total_size) / cluster_size, |
| 3505 | cluster_size, refcount_order, false, NULL); |
| 3506 | |
| 3507 | return meta_size + aligned_total_size; |
| 3508 | } |
| 3509 | |
| 3510 | static bool validate_cluster_size(size_t cluster_size, bool extended_l2, |
| 3511 | Error **errp) |
| 3512 | { |
| 3513 | int cluster_bits = ctz32(cluster_size); |
| 3514 | if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || |
| 3515 | (1 << cluster_bits) != cluster_size) |
| 3516 | { |
| 3517 | error_setg(errp, "Cluster size must be a power of two between %d and " |
| 3518 | "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); |
| 3519 | return false; |
| 3520 | } |
| 3521 | |
| 3522 | if (extended_l2) { |
| 3523 | unsigned min_cluster_size = |
| 3524 | (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER; |
| 3525 | if (cluster_size < min_cluster_size) { |
| 3526 | error_setg(errp, "Extended L2 entries are only supported with " |
| 3527 | "cluster sizes of at least %u bytes", min_cluster_size); |
| 3528 | return false; |
| 3529 | } |
| 3530 | } |
| 3531 | |
| 3532 | return true; |
| 3533 | } |
| 3534 | |
| 3535 | static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2, |
| 3536 | Error **errp) |
| 3537 | { |
| 3538 | size_t cluster_size; |
| 3539 | |
| 3540 | cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, |
| 3541 | DEFAULT_CLUSTER_SIZE); |
| 3542 | if (!validate_cluster_size(cluster_size, extended_l2, errp)) { |
| 3543 | return 0; |
| 3544 | } |
| 3545 | return cluster_size; |
| 3546 | } |
| 3547 | |
| 3548 | static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp) |
| 3549 | { |
| 3550 | char *buf; |
| 3551 | int ret; |
| 3552 | |
| 3553 | buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); |
| 3554 | if (!buf) { |
| 3555 | ret = 3; /* default */ |
| 3556 | } else if (!strcmp(buf, "0.10")) { |
| 3557 | ret = 2; |
| 3558 | } else if (!strcmp(buf, "1.1")) { |
| 3559 | ret = 3; |
| 3560 | } else { |
| 3561 | error_setg(errp, "Invalid compatibility level: '%s'", buf); |
| 3562 | ret = -EINVAL; |
| 3563 | } |
| 3564 | g_free(buf); |
| 3565 | return ret; |
| 3566 | } |
| 3567 | |
| 3568 | static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version, |
| 3569 | Error **errp) |
| 3570 | { |
| 3571 | uint64_t refcount_bits; |
| 3572 | |
| 3573 | refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16); |
| 3574 | if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { |
| 3575 | error_setg(errp, "Refcount width must be a power of two and may not " |
| 3576 | "exceed 64 bits"); |
| 3577 | return 0; |
| 3578 | } |
| 3579 | |
| 3580 | if (version < 3 && refcount_bits != 16) { |
| 3581 | error_setg(errp, "Different refcount widths than 16 bits require " |
| 3582 | "compatibility level 1.1 or above (use compat=1.1 or " |
| 3583 | "greater)"); |
| 3584 | return 0; |
| 3585 | } |
| 3586 | |
| 3587 | return refcount_bits; |
| 3588 | } |
| 3589 | |
| 3590 | static int coroutine_fn GRAPH_UNLOCKED |
| 3591 | qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp) |
| 3592 | { |
| 3593 | ERRP_GUARD(); |
| 3594 | BlockdevCreateOptionsQcow2 *qcow2_opts; |
| 3595 | QDict *options; |
| 3596 | |
| 3597 | /* |
| 3598 | * Open the image file and write a minimal qcow2 header. |
| 3599 | * |
| 3600 | * We keep things simple and start with a zero-sized image. We also |
| 3601 | * do without refcount blocks or a L1 table for now. We'll fix the |
| 3602 | * inconsistency later. |
| 3603 | * |
| 3604 | * We do need a refcount table because growing the refcount table means |
| 3605 | * allocating two new refcount blocks - the second of which would be at |
| 3606 | * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file |
| 3607 | * size for any qcow2 image. |
| 3608 | */ |
| 3609 | BlockBackend *blk = NULL; |
| 3610 | BlockDriverState *bs = NULL; |
| 3611 | BlockDriverState *data_bs = NULL; |
| 3612 | QCowHeader *header; |
| 3613 | size_t cluster_size; |
| 3614 | int version; |
| 3615 | int refcount_order; |
| 3616 | uint64_t *refcount_table; |
| 3617 | int ret; |
| 3618 | uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB; |
| 3619 | |
| 3620 | assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2); |
| 3621 | qcow2_opts = &create_options->u.qcow2; |
| 3622 | |
| 3623 | bs = bdrv_co_open_blockdev_ref(qcow2_opts->file, errp); |
| 3624 | if (bs == NULL) { |
| 3625 | return -EIO; |
| 3626 | } |
| 3627 | |
| 3628 | /* Validate options and set default values */ |
| 3629 | if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) { |
| 3630 | error_setg(errp, "Image size must be a multiple of %u bytes", |
| 3631 | (unsigned) BDRV_SECTOR_SIZE); |
| 3632 | ret = -EINVAL; |
| 3633 | goto out; |
| 3634 | } |
| 3635 | |
| 3636 | if (qcow2_opts->has_version) { |
| 3637 | switch (qcow2_opts->version) { |
| 3638 | case BLOCKDEV_QCOW2_VERSION_V2: |
| 3639 | version = 2; |
| 3640 | break; |
| 3641 | case BLOCKDEV_QCOW2_VERSION_V3: |
| 3642 | version = 3; |
| 3643 | break; |
| 3644 | default: |
| 3645 | g_assert_not_reached(); |
| 3646 | } |
| 3647 | } else { |
| 3648 | version = 3; |
| 3649 | } |
| 3650 | |
| 3651 | if (qcow2_opts->has_cluster_size) { |
| 3652 | cluster_size = qcow2_opts->cluster_size; |
| 3653 | } else { |
| 3654 | cluster_size = DEFAULT_CLUSTER_SIZE; |
| 3655 | } |
| 3656 | |
| 3657 | if (!qcow2_opts->has_extended_l2) { |
| 3658 | qcow2_opts->extended_l2 = false; |
| 3659 | } |
| 3660 | if (qcow2_opts->extended_l2) { |
| 3661 | if (version < 3) { |
| 3662 | error_setg(errp, "Extended L2 entries are only supported with " |
| 3663 | "compatibility level 1.1 and above (use version=v3 or " |
| 3664 | "greater)"); |
| 3665 | ret = -EINVAL; |
| 3666 | goto out; |
| 3667 | } |
| 3668 | } |
| 3669 | |
| 3670 | if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) { |
| 3671 | ret = -EINVAL; |
| 3672 | goto out; |
| 3673 | } |
| 3674 | |
| 3675 | if (!qcow2_opts->has_preallocation) { |
| 3676 | qcow2_opts->preallocation = PREALLOC_MODE_OFF; |
| 3677 | } |
| 3678 | if (qcow2_opts->backing_file && |
| 3679 | qcow2_opts->preallocation != PREALLOC_MODE_OFF && |
| 3680 | !qcow2_opts->extended_l2) |
| 3681 | { |
| 3682 | error_setg(errp, "Backing file and preallocation can only be used at " |
| 3683 | "the same time if extended_l2 is on"); |
| 3684 | ret = -EINVAL; |
| 3685 | goto out; |
| 3686 | } |
| 3687 | if (qcow2_opts->has_backing_fmt && !qcow2_opts->backing_file) { |
| 3688 | error_setg(errp, "Backing format cannot be used without backing file"); |
| 3689 | ret = -EINVAL; |
| 3690 | goto out; |
| 3691 | } |
| 3692 | |
| 3693 | if (!qcow2_opts->has_lazy_refcounts) { |
| 3694 | qcow2_opts->lazy_refcounts = false; |
| 3695 | } |
| 3696 | if (version < 3 && qcow2_opts->lazy_refcounts) { |
| 3697 | error_setg(errp, "Lazy refcounts only supported with compatibility " |
| 3698 | "level 1.1 and above (use version=v3 or greater)"); |
| 3699 | ret = -EINVAL; |
| 3700 | goto out; |
| 3701 | } |
| 3702 | |
| 3703 | if (!qcow2_opts->has_refcount_bits) { |
| 3704 | qcow2_opts->refcount_bits = 16; |
| 3705 | } |
| 3706 | if (qcow2_opts->refcount_bits > 64 || |
| 3707 | !is_power_of_2(qcow2_opts->refcount_bits)) |
| 3708 | { |
| 3709 | error_setg(errp, "Refcount width must be a power of two and may not " |
| 3710 | "exceed 64 bits"); |
| 3711 | ret = -EINVAL; |
| 3712 | goto out; |
| 3713 | } |
| 3714 | if (version < 3 && qcow2_opts->refcount_bits != 16) { |
| 3715 | error_setg(errp, "Different refcount widths than 16 bits require " |
| 3716 | "compatibility level 1.1 or above (use version=v3 or " |
| 3717 | "greater)"); |
| 3718 | ret = -EINVAL; |
| 3719 | goto out; |
| 3720 | } |
| 3721 | refcount_order = ctz32(qcow2_opts->refcount_bits); |
| 3722 | |
| 3723 | if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) { |
| 3724 | error_setg(errp, "data-file-raw requires data-file"); |
| 3725 | ret = -EINVAL; |
| 3726 | goto out; |
| 3727 | } |
| 3728 | if (qcow2_opts->data_file_raw && qcow2_opts->backing_file) { |
| 3729 | error_setg(errp, "Backing file and data-file-raw cannot be used at " |
| 3730 | "the same time"); |
| 3731 | ret = -EINVAL; |
| 3732 | goto out; |
| 3733 | } |
| 3734 | if (qcow2_opts->data_file_raw && |
| 3735 | qcow2_opts->preallocation == PREALLOC_MODE_OFF) |
| 3736 | { |
| 3737 | /* |
| 3738 | * data-file-raw means that "the external data file can be |
| 3739 | * read as a consistent standalone raw image without looking |
| 3740 | * at the qcow2 metadata." It does not say that the metadata |
| 3741 | * must be ignored, though (and the qcow2 driver in fact does |
| 3742 | * not ignore it), so the L1/L2 tables must be present and |
| 3743 | * give a 1:1 mapping, so you get the same result regardless |
| 3744 | * of whether you look at the metadata or whether you ignore |
| 3745 | * it. |
| 3746 | */ |
| 3747 | qcow2_opts->preallocation = PREALLOC_MODE_METADATA; |
| 3748 | |
| 3749 | /* |
| 3750 | * Cannot use preallocation with backing files, but giving a |
| 3751 | * backing file when specifying data_file_raw is an error |
| 3752 | * anyway. |
| 3753 | */ |
| 3754 | assert(!qcow2_opts->backing_file); |
| 3755 | } |
| 3756 | |
| 3757 | if (qcow2_opts->data_file) { |
| 3758 | if (version < 3) { |
| 3759 | error_setg(errp, "External data files are only supported with " |
| 3760 | "compatibility level 1.1 and above (use version=v3 or " |
| 3761 | "greater)"); |
| 3762 | ret = -EINVAL; |
| 3763 | goto out; |
| 3764 | } |
| 3765 | data_bs = bdrv_co_open_blockdev_ref(qcow2_opts->data_file, errp); |
| 3766 | if (data_bs == NULL) { |
| 3767 | ret = -EIO; |
| 3768 | goto out; |
| 3769 | } |
| 3770 | } |
| 3771 | |
| 3772 | if (qcow2_opts->has_compression_type && |
| 3773 | qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { |
| 3774 | |
| 3775 | ret = -EINVAL; |
| 3776 | |
| 3777 | if (version < 3) { |
| 3778 | error_setg(errp, "Non-zlib compression type is only supported with " |
| 3779 | "compatibility level 1.1 and above (use version=v3 or " |
| 3780 | "greater)"); |
| 3781 | goto out; |
| 3782 | } |
| 3783 | |
| 3784 | switch (qcow2_opts->compression_type) { |
| 3785 | #ifdef CONFIG_ZSTD |
| 3786 | case QCOW2_COMPRESSION_TYPE_ZSTD: |
| 3787 | break; |
| 3788 | #endif |
| 3789 | default: |
| 3790 | error_setg(errp, "Unknown compression type"); |
| 3791 | goto out; |
| 3792 | } |
| 3793 | |
| 3794 | compression_type = qcow2_opts->compression_type; |
| 3795 | } |
| 3796 | |
| 3797 | /* Create BlockBackend to write to the image */ |
| 3798 | blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, |
| 3799 | errp); |
| 3800 | if (!blk) { |
| 3801 | ret = -EPERM; |
| 3802 | goto out; |
| 3803 | } |
| 3804 | blk_set_allow_write_beyond_eof(blk, true); |
| 3805 | |
| 3806 | /* Write the header */ |
| 3807 | QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); |
| 3808 | header = g_malloc0(cluster_size); |
| 3809 | *header = (QCowHeader) { |
| 3810 | .magic = cpu_to_be32(QCOW_MAGIC), |
| 3811 | .version = cpu_to_be32(version), |
| 3812 | .cluster_bits = cpu_to_be32(ctz32(cluster_size)), |
| 3813 | .size = cpu_to_be64(0), |
| 3814 | .l1_table_offset = cpu_to_be64(0), |
| 3815 | .l1_size = cpu_to_be32(0), |
| 3816 | .refcount_table_offset = cpu_to_be64(cluster_size), |
| 3817 | .refcount_table_clusters = cpu_to_be32(1), |
| 3818 | .refcount_order = cpu_to_be32(refcount_order), |
| 3819 | /* don't deal with endianness since compression_type is 1 byte long */ |
| 3820 | .compression_type = compression_type, |
| 3821 | .header_length = cpu_to_be32(sizeof(*header)), |
| 3822 | }; |
| 3823 | |
| 3824 | /* We'll update this to correct value later */ |
| 3825 | header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
| 3826 | |
| 3827 | if (qcow2_opts->lazy_refcounts) { |
| 3828 | header->compatible_features |= |
| 3829 | cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); |
| 3830 | } |
| 3831 | if (data_bs) { |
| 3832 | header->incompatible_features |= |
| 3833 | cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE); |
| 3834 | } |
| 3835 | if (qcow2_opts->data_file_raw) { |
| 3836 | header->autoclear_features |= |
| 3837 | cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW); |
| 3838 | } |
| 3839 | if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) { |
| 3840 | header->incompatible_features |= |
| 3841 | cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); |
| 3842 | } |
| 3843 | |
| 3844 | if (qcow2_opts->extended_l2) { |
| 3845 | header->incompatible_features |= |
| 3846 | cpu_to_be64(QCOW2_INCOMPAT_EXTL2); |
| 3847 | } |
| 3848 | |
| 3849 | ret = blk_co_pwrite(blk, 0, cluster_size, header, 0); |
| 3850 | g_free(header); |
| 3851 | if (ret < 0) { |
| 3852 | error_setg_errno(errp, -ret, "Could not write qcow2 header"); |
| 3853 | goto out; |
| 3854 | } |
| 3855 | |
| 3856 | /* Write a refcount table with one refcount block */ |
| 3857 | refcount_table = g_malloc0(2 * cluster_size); |
| 3858 | refcount_table[0] = cpu_to_be64(2 * cluster_size); |
| 3859 | ret = blk_co_pwrite(blk, cluster_size, 2 * cluster_size, refcount_table, 0); |
| 3860 | g_free(refcount_table); |
| 3861 | |
| 3862 | if (ret < 0) { |
| 3863 | error_setg_errno(errp, -ret, "Could not write refcount table"); |
| 3864 | goto out; |
| 3865 | } |
| 3866 | |
| 3867 | blk_co_unref(blk); |
| 3868 | blk = NULL; |
| 3869 | |
| 3870 | /* |
| 3871 | * And now open the image and make it consistent first (i.e. increase the |
| 3872 | * refcount of the cluster that is occupied by the header and the refcount |
| 3873 | * table) |
| 3874 | */ |
| 3875 | options = qdict_new(); |
| 3876 | qdict_put_str(options, "driver", "qcow2"); |
| 3877 | qdict_put_str(options, "file", bs->node_name); |
| 3878 | if (data_bs) { |
| 3879 | qdict_put_str(options, "data-file", data_bs->node_name); |
| 3880 | } |
| 3881 | blk = blk_co_new_open(NULL, NULL, options, |
| 3882 | BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, |
| 3883 | errp); |
| 3884 | if (blk == NULL) { |
| 3885 | ret = -EIO; |
| 3886 | goto out; |
| 3887 | } |
| 3888 | |
| 3889 | bdrv_graph_co_rdlock(); |
| 3890 | ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); |
| 3891 | if (ret < 0) { |
| 3892 | bdrv_graph_co_rdunlock(); |
| 3893 | error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " |
| 3894 | "header and refcount table"); |
| 3895 | goto out; |
| 3896 | |
| 3897 | } else if (ret != 0) { |
| 3898 | error_report("Huh, first cluster in empty image is already in use?"); |
| 3899 | abort(); |
| 3900 | } |
| 3901 | |
| 3902 | /* Set the external data file if necessary */ |
| 3903 | if (data_bs) { |
| 3904 | BDRVQcow2State *s = blk_bs(blk)->opaque; |
| 3905 | s->image_data_file = g_strdup(data_bs->filename); |
| 3906 | } |
| 3907 | |
| 3908 | /* Create a full header (including things like feature table) */ |
| 3909 | ret = qcow2_update_header(blk_bs(blk)); |
| 3910 | bdrv_graph_co_rdunlock(); |
| 3911 | |
| 3912 | if (ret < 0) { |
| 3913 | error_setg_errno(errp, -ret, "Could not update qcow2 header"); |
| 3914 | goto out; |
| 3915 | } |
| 3916 | |
| 3917 | /* Okay, now that we have a valid image, let's give it the right size */ |
| 3918 | ret = blk_co_truncate(blk, qcow2_opts->size, false, |
| 3919 | qcow2_opts->preallocation, 0, errp); |
| 3920 | if (ret < 0) { |
| 3921 | error_prepend(errp, "Could not resize image: "); |
| 3922 | goto out; |
| 3923 | } |
| 3924 | |
| 3925 | /* Want a backing file? There you go. */ |
| 3926 | if (qcow2_opts->backing_file) { |
| 3927 | const char *backing_format = NULL; |
| 3928 | |
| 3929 | if (qcow2_opts->has_backing_fmt) { |
| 3930 | backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt); |
| 3931 | } |
| 3932 | |
| 3933 | bdrv_graph_co_rdlock(); |
| 3934 | ret = bdrv_co_change_backing_file(blk_bs(blk), qcow2_opts->backing_file, |
| 3935 | backing_format, false); |
| 3936 | bdrv_graph_co_rdunlock(); |
| 3937 | |
| 3938 | if (ret < 0) { |
| 3939 | error_setg_errno(errp, -ret, "Could not assign backing file '%s' " |
| 3940 | "with format '%s'", qcow2_opts->backing_file, |
| 3941 | backing_format); |
| 3942 | goto out; |
| 3943 | } |
| 3944 | } |
| 3945 | |
| 3946 | /* Want encryption? There you go. */ |
| 3947 | if (qcow2_opts->encrypt) { |
| 3948 | bdrv_graph_co_rdlock(); |
| 3949 | ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp); |
| 3950 | bdrv_graph_co_rdunlock(); |
| 3951 | |
| 3952 | if (ret < 0) { |
| 3953 | goto out; |
| 3954 | } |
| 3955 | } |
| 3956 | |
| 3957 | blk_co_unref(blk); |
| 3958 | blk = NULL; |
| 3959 | |
| 3960 | /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning. |
| 3961 | * Using BDRV_O_NO_IO, since encryption is now setup we don't want to |
| 3962 | * have to setup decryption context. We're not doing any I/O on the top |
| 3963 | * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does |
| 3964 | * not have effect. |
| 3965 | */ |
| 3966 | options = qdict_new(); |
| 3967 | qdict_put_str(options, "driver", "qcow2"); |
| 3968 | qdict_put_str(options, "file", bs->node_name); |
| 3969 | if (data_bs) { |
| 3970 | qdict_put_str(options, "data-file", data_bs->node_name); |
| 3971 | } |
| 3972 | blk = blk_co_new_open(NULL, NULL, options, |
| 3973 | BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, |
| 3974 | errp); |
| 3975 | if (blk == NULL) { |
| 3976 | ret = -EIO; |
| 3977 | goto out; |
| 3978 | } |
| 3979 | |
| 3980 | ret = 0; |
| 3981 | out: |
| 3982 | blk_co_unref(blk); |
| 3983 | bdrv_co_unref(bs); |
| 3984 | bdrv_co_unref(data_bs); |
| 3985 | return ret; |
| 3986 | } |
| 3987 | |
| 3988 | static int coroutine_fn GRAPH_UNLOCKED |
| 3989 | qcow2_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, |
| 3990 | Error **errp) |
| 3991 | { |
| 3992 | BlockdevCreateOptions *create_options = NULL; |
| 3993 | QDict *qdict; |
| 3994 | Visitor *v; |
| 3995 | BlockDriverState *bs = NULL; |
| 3996 | BlockDriverState *data_bs = NULL; |
| 3997 | const char *val; |
| 3998 | bool keep_data_file = false; |
| 3999 | BlockdevCreateOptionsQcow2 *qcow2_opts; |
| 4000 | int ret; |
| 4001 | |
| 4002 | /* Only the keyval visitor supports the dotted syntax needed for |
| 4003 | * encryption, so go through a QDict before getting a QAPI type. Ignore |
| 4004 | * options meant for the protocol layer so that the visitor doesn't |
| 4005 | * complain. */ |
| 4006 | qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts, |
| 4007 | true); |
| 4008 | |
| 4009 | /* Handle encryption options */ |
| 4010 | val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); |
| 4011 | if (val && !strcmp(val, "on")) { |
| 4012 | qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); |
| 4013 | } else if (val && !strcmp(val, "off")) { |
| 4014 | qdict_del(qdict, BLOCK_OPT_ENCRYPT); |
| 4015 | } |
| 4016 | |
| 4017 | val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); |
| 4018 | if (val && !strcmp(val, "aes")) { |
| 4019 | qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); |
| 4020 | } |
| 4021 | |
| 4022 | /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into |
| 4023 | * version=v2/v3 below. */ |
| 4024 | val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL); |
| 4025 | if (val && !strcmp(val, "0.10")) { |
| 4026 | qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2"); |
| 4027 | } else if (val && !strcmp(val, "1.1")) { |
| 4028 | qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3"); |
| 4029 | } |
| 4030 | |
| 4031 | val = qdict_get_try_str(qdict, BLOCK_OPT_KEEP_DATA_FILE); |
| 4032 | if (val) { |
| 4033 | if (!strcmp(val, "on")) { |
| 4034 | keep_data_file = true; |
| 4035 | } else if (!strcmp(val, "off")) { |
| 4036 | keep_data_file = false; |
| 4037 | } else { |
| 4038 | error_setg(errp, |
| 4039 | "Invalid value '%s' for '%s': Must be 'on' or 'off'", |
| 4040 | val, BLOCK_OPT_KEEP_DATA_FILE); |
| 4041 | ret = -EINVAL; |
| 4042 | goto finish; |
| 4043 | } |
| 4044 | qdict_del(qdict, BLOCK_OPT_KEEP_DATA_FILE); |
| 4045 | } |
| 4046 | |
| 4047 | /* Change legacy command line options into QMP ones */ |
| 4048 | static const QDictRenames opt_renames[] = { |
| 4049 | { BLOCK_OPT_BACKING_FILE, "backing-file" }, |
| 4050 | { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, |
| 4051 | { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, |
| 4052 | { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" }, |
| 4053 | { BLOCK_OPT_EXTL2, "extended-l2" }, |
| 4054 | { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" }, |
| 4055 | { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, |
| 4056 | { BLOCK_OPT_COMPAT_LEVEL, "version" }, |
| 4057 | { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" }, |
| 4058 | { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" }, |
| 4059 | { NULL, NULL }, |
| 4060 | }; |
| 4061 | |
| 4062 | if (!qdict_rename_keys(qdict, opt_renames, errp)) { |
| 4063 | ret = -EINVAL; |
| 4064 | goto finish; |
| 4065 | } |
| 4066 | |
| 4067 | /* Create and open the file (protocol layer) */ |
| 4068 | ret = bdrv_co_create_file(filename, opts, true, errp); |
| 4069 | if (ret < 0) { |
| 4070 | goto finish; |
| 4071 | } |
| 4072 | |
| 4073 | bs = bdrv_co_open(filename, NULL, NULL, |
| 4074 | BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); |
| 4075 | if (bs == NULL) { |
| 4076 | ret = -EIO; |
| 4077 | goto finish; |
| 4078 | } |
| 4079 | |
| 4080 | /* Create and open an external data file (protocol layer) */ |
| 4081 | val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE); |
| 4082 | if (val) { |
| 4083 | if (!keep_data_file) { |
| 4084 | ret = bdrv_co_create_file(val, opts, false, errp); |
| 4085 | if (ret < 0) { |
| 4086 | goto finish; |
| 4087 | } |
| 4088 | } |
| 4089 | |
| 4090 | data_bs = bdrv_co_open(val, NULL, NULL, |
| 4091 | BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, |
| 4092 | errp); |
| 4093 | if (data_bs == NULL) { |
| 4094 | ret = -EIO; |
| 4095 | goto finish; |
| 4096 | } |
| 4097 | |
| 4098 | qdict_del(qdict, BLOCK_OPT_DATA_FILE); |
| 4099 | qdict_put_str(qdict, "data-file", data_bs->node_name); |
| 4100 | } else if (keep_data_file) { |
| 4101 | error_setg(errp, "Must not use '%s=on' without '%s'", |
| 4102 | BLOCK_OPT_KEEP_DATA_FILE, BLOCK_OPT_DATA_FILE); |
| 4103 | ret = -EINVAL; |
| 4104 | goto finish; |
| 4105 | } |
| 4106 | |
| 4107 | /* Set 'driver' and 'node' options */ |
| 4108 | qdict_put_str(qdict, "driver", "qcow2"); |
| 4109 | qdict_put_str(qdict, "file", bs->node_name); |
| 4110 | |
| 4111 | /* Now get the QAPI type BlockdevCreateOptions */ |
| 4112 | v = qobject_input_visitor_new_flat_confused(qdict, errp); |
| 4113 | if (!v) { |
| 4114 | ret = -EINVAL; |
| 4115 | goto finish; |
| 4116 | } |
| 4117 | |
| 4118 | visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); |
| 4119 | visit_free(v); |
| 4120 | if (!create_options) { |
| 4121 | ret = -EINVAL; |
| 4122 | goto finish; |
| 4123 | } |
| 4124 | |
| 4125 | qcow2_opts = &create_options->u.qcow2; |
| 4126 | |
| 4127 | if (!qcow2_opts->has_preallocation) { |
| 4128 | qcow2_opts->preallocation = PREALLOC_MODE_OFF; |
| 4129 | } |
| 4130 | |
| 4131 | if (keep_data_file && |
| 4132 | qcow2_opts->preallocation != PREALLOC_MODE_OFF && |
| 4133 | qcow2_opts->preallocation != PREALLOC_MODE_METADATA) |
| 4134 | { |
| 4135 | error_setg(errp, "Preallocating more than only metadata would " |
| 4136 | "overwrite the external data file's content and is " |
| 4137 | "therefore incompatible with '%s=on'", |
| 4138 | BLOCK_OPT_KEEP_DATA_FILE); |
| 4139 | ret = -EINVAL; |
| 4140 | goto finish; |
| 4141 | } |
| 4142 | |
| 4143 | if (keep_data_file && |
| 4144 | qcow2_opts->preallocation == PREALLOC_MODE_OFF && |
| 4145 | !qcow2_opts->data_file_raw) |
| 4146 | { |
| 4147 | error_setg(errp, "'%s=on' requires '%s=metadata' or '%s=on', or the " |
| 4148 | "file contents will not be visible", |
| 4149 | BLOCK_OPT_KEEP_DATA_FILE, |
| 4150 | BLOCK_OPT_PREALLOC, |
| 4151 | BLOCK_OPT_DATA_FILE_RAW); |
| 4152 | ret = -EINVAL; |
| 4153 | goto finish; |
| 4154 | } |
| 4155 | |
| 4156 | /* Silently round up size */ |
| 4157 | qcow2_opts->size = ROUND_UP(qcow2_opts->size, BDRV_SECTOR_SIZE); |
| 4158 | |
| 4159 | /* Create the qcow2 image (format layer) */ |
| 4160 | ret = qcow2_co_create(create_options, errp); |
| 4161 | finish: |
| 4162 | if (ret < 0) { |
| 4163 | bdrv_graph_co_rdlock(); |
| 4164 | bdrv_co_delete_file_noerr(bs); |
| 4165 | if (!keep_data_file) { |
| 4166 | bdrv_co_delete_file_noerr(data_bs); |
| 4167 | } |
| 4168 | bdrv_graph_co_rdunlock(); |
| 4169 | } else { |
| 4170 | ret = 0; |
| 4171 | } |
| 4172 | |
| 4173 | qobject_unref(qdict); |
| 4174 | bdrv_co_unref(bs); |
| 4175 | bdrv_co_unref(data_bs); |
| 4176 | qapi_free_BlockdevCreateOptions(create_options); |
| 4177 | return ret; |
| 4178 | } |
| 4179 | |
| 4180 | |
| 4181 | static bool coroutine_fn GRAPH_RDLOCK |
| 4182 | is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) |
| 4183 | { |
| 4184 | int64_t nr; |
| 4185 | int res; |
| 4186 | |
| 4187 | /* Clamp to image length, before checking status of underlying sectors */ |
| 4188 | if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { |
| 4189 | bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset; |
| 4190 | } |
| 4191 | |
| 4192 | if (!bytes) { |
| 4193 | return true; |
| 4194 | } |
| 4195 | |
| 4196 | /* |
| 4197 | * bdrv_block_status_above doesn't merge different types of zeros, for |
| 4198 | * example, zeros which come from the region which is unallocated in |
| 4199 | * the whole backing chain, and zeros which come because of a short |
| 4200 | * backing file. So, we need a loop. |
| 4201 | */ |
| 4202 | do { |
| 4203 | res = bdrv_co_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); |
| 4204 | offset += nr; |
| 4205 | bytes -= nr; |
| 4206 | } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes); |
| 4207 | |
| 4208 | return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0; |
| 4209 | } |
| 4210 | |
| 4211 | static int coroutine_fn GRAPH_RDLOCK |
| 4212 | qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 4213 | BdrvRequestFlags flags) |
| 4214 | { |
| 4215 | int ret; |
| 4216 | BDRVQcow2State *s = bs->opaque; |
| 4217 | |
| 4218 | uint32_t head = offset_into_subcluster(s, offset); |
| 4219 | uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) - |
| 4220 | (offset + bytes); |
| 4221 | |
| 4222 | trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); |
| 4223 | if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { |
| 4224 | tail = 0; |
| 4225 | } |
| 4226 | |
| 4227 | if (head || tail) { |
| 4228 | uint64_t off; |
| 4229 | unsigned int nr; |
| 4230 | QCow2SubclusterType type; |
| 4231 | |
| 4232 | assert(head + bytes + tail <= s->subcluster_size); |
| 4233 | |
| 4234 | /* check whether remainder of cluster already reads as zero */ |
| 4235 | if (!(is_zero(bs, offset - head, head) && |
| 4236 | is_zero(bs, offset + bytes, tail))) { |
| 4237 | return -ENOTSUP; |
| 4238 | } |
| 4239 | |
| 4240 | qemu_co_mutex_lock(&s->lock); |
| 4241 | offset -= head; |
| 4242 | bytes = s->subcluster_size; |
| 4243 | nr = s->subcluster_size; |
| 4244 | /* |
| 4245 | * Wait for in-flight allocating writes first: otherwise the type |
| 4246 | * check below could pass on UNALLOCATED while a yet-to-link_l2 write |
| 4247 | * completes during qcow2_subcluster_zeroize()'s own wait, letting the |
| 4248 | * resumed MAY_UNMAP discard the just-written data. |
| 4249 | */ |
| 4250 | qcow2_wait_for_dependencies(bs, offset, bytes); |
| 4251 | ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type); |
| 4252 | if (ret < 0 || |
| 4253 | (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && |
| 4254 | type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && |
| 4255 | type != QCOW2_SUBCLUSTER_ZERO_PLAIN && |
| 4256 | type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) { |
| 4257 | qemu_co_mutex_unlock(&s->lock); |
| 4258 | return ret < 0 ? ret : -ENOTSUP; |
| 4259 | } |
| 4260 | } else { |
| 4261 | qemu_co_mutex_lock(&s->lock); |
| 4262 | } |
| 4263 | |
| 4264 | trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); |
| 4265 | |
| 4266 | /* Whatever is left can use real zero subclusters */ |
| 4267 | ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags); |
| 4268 | qemu_co_mutex_unlock(&s->lock); |
| 4269 | |
| 4270 | return ret; |
| 4271 | } |
| 4272 | |
| 4273 | static int coroutine_fn GRAPH_RDLOCK |
| 4274 | qcow2_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) |
| 4275 | { |
| 4276 | int ret; |
| 4277 | BDRVQcow2State *s = bs->opaque; |
| 4278 | |
| 4279 | /* If the image does not support QCOW_OFLAG_ZERO then discarding |
| 4280 | * clusters could expose stale data from the backing file. */ |
| 4281 | if (s->qcow_version < 3 && bs->backing) { |
| 4282 | return -ENOTSUP; |
| 4283 | } |
| 4284 | |
| 4285 | if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) { |
| 4286 | assert(bytes < s->cluster_size); |
| 4287 | /* Ignore partial clusters, except for the special case of the |
| 4288 | * complete partial cluster at the end of an unaligned file */ |
| 4289 | if (!QEMU_IS_ALIGNED(offset, s->cluster_size) || |
| 4290 | offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) { |
| 4291 | return -ENOTSUP; |
| 4292 | } |
| 4293 | } |
| 4294 | |
| 4295 | qemu_co_mutex_lock(&s->lock); |
| 4296 | ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST, |
| 4297 | false); |
| 4298 | qemu_co_mutex_unlock(&s->lock); |
| 4299 | return ret; |
| 4300 | } |
| 4301 | |
| 4302 | static int coroutine_fn GRAPH_RDLOCK |
| 4303 | qcow2_co_copy_range_from(BlockDriverState *bs, |
| 4304 | BdrvChild *src, int64_t src_offset, |
| 4305 | BdrvChild *dst, int64_t dst_offset, |
| 4306 | int64_t bytes, BdrvRequestFlags read_flags, |
| 4307 | BdrvRequestFlags write_flags) |
| 4308 | { |
| 4309 | BDRVQcow2State *s = bs->opaque; |
| 4310 | int ret; |
| 4311 | unsigned int cur_bytes; /* number of bytes in current iteration */ |
| 4312 | BdrvChild *child = NULL; |
| 4313 | BdrvRequestFlags cur_write_flags; |
| 4314 | |
| 4315 | assert(!bs->encrypted); |
| 4316 | qemu_co_mutex_lock(&s->lock); |
| 4317 | |
| 4318 | while (bytes != 0) { |
| 4319 | uint64_t copy_offset = 0; |
| 4320 | QCow2SubclusterType type; |
| 4321 | /* prepare next request */ |
| 4322 | cur_bytes = MIN(bytes, INT_MAX); |
| 4323 | cur_write_flags = write_flags; |
| 4324 | |
| 4325 | ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes, |
| 4326 | ©_offset, &type); |
| 4327 | if (ret < 0) { |
| 4328 | goto out; |
| 4329 | } |
| 4330 | |
| 4331 | switch (type) { |
| 4332 | case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN: |
| 4333 | case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC: |
| 4334 | if (bs->backing && bs->backing->bs) { |
| 4335 | int64_t backing_length = bdrv_co_getlength(bs->backing->bs); |
| 4336 | if (src_offset >= backing_length) { |
| 4337 | cur_write_flags |= BDRV_REQ_ZERO_WRITE; |
| 4338 | } else { |
| 4339 | child = bs->backing; |
| 4340 | cur_bytes = MIN(cur_bytes, backing_length - src_offset); |
| 4341 | copy_offset = src_offset; |
| 4342 | } |
| 4343 | } else { |
| 4344 | cur_write_flags |= BDRV_REQ_ZERO_WRITE; |
| 4345 | } |
| 4346 | break; |
| 4347 | |
| 4348 | case QCOW2_SUBCLUSTER_ZERO_PLAIN: |
| 4349 | case QCOW2_SUBCLUSTER_ZERO_ALLOC: |
| 4350 | cur_write_flags |= BDRV_REQ_ZERO_WRITE; |
| 4351 | break; |
| 4352 | |
| 4353 | case QCOW2_SUBCLUSTER_COMPRESSED: |
| 4354 | ret = -ENOTSUP; |
| 4355 | goto out; |
| 4356 | |
| 4357 | case QCOW2_SUBCLUSTER_NORMAL: |
| 4358 | child = s->data_file; |
| 4359 | break; |
| 4360 | |
| 4361 | default: |
| 4362 | abort(); |
| 4363 | } |
| 4364 | qemu_co_mutex_unlock(&s->lock); |
| 4365 | ret = bdrv_co_copy_range_from(child, |
| 4366 | copy_offset, |
| 4367 | dst, dst_offset, |
| 4368 | cur_bytes, read_flags, cur_write_flags); |
| 4369 | qemu_co_mutex_lock(&s->lock); |
| 4370 | if (ret < 0) { |
| 4371 | goto out; |
| 4372 | } |
| 4373 | |
| 4374 | bytes -= cur_bytes; |
| 4375 | src_offset += cur_bytes; |
| 4376 | dst_offset += cur_bytes; |
| 4377 | } |
| 4378 | ret = 0; |
| 4379 | |
| 4380 | out: |
| 4381 | qemu_co_mutex_unlock(&s->lock); |
| 4382 | return ret; |
| 4383 | } |
| 4384 | |
| 4385 | static int coroutine_fn GRAPH_RDLOCK |
| 4386 | qcow2_co_copy_range_to(BlockDriverState *bs, |
| 4387 | BdrvChild *src, int64_t src_offset, |
| 4388 | BdrvChild *dst, int64_t dst_offset, |
| 4389 | int64_t bytes, BdrvRequestFlags read_flags, |
| 4390 | BdrvRequestFlags write_flags) |
| 4391 | { |
| 4392 | BDRVQcow2State *s = bs->opaque; |
| 4393 | int ret; |
| 4394 | unsigned int cur_bytes; /* number of sectors in current iteration */ |
| 4395 | uint64_t host_offset; |
| 4396 | QCowL2Meta *l2meta = NULL; |
| 4397 | |
| 4398 | assert(!bs->encrypted); |
| 4399 | |
| 4400 | qemu_co_mutex_lock(&s->lock); |
| 4401 | |
| 4402 | while (bytes != 0) { |
| 4403 | |
| 4404 | l2meta = NULL; |
| 4405 | |
| 4406 | cur_bytes = MIN(bytes, INT_MAX); |
| 4407 | |
| 4408 | /* TODO: |
| 4409 | * If src->bs == dst->bs, we could simply copy by incrementing |
| 4410 | * the refcnt, without copying user data. |
| 4411 | * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */ |
| 4412 | ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes, |
| 4413 | &host_offset, &l2meta); |
| 4414 | if (ret < 0) { |
| 4415 | goto fail; |
| 4416 | } |
| 4417 | |
| 4418 | ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes, |
| 4419 | true); |
| 4420 | if (ret < 0) { |
| 4421 | goto fail; |
| 4422 | } |
| 4423 | |
| 4424 | qemu_co_mutex_unlock(&s->lock); |
| 4425 | ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset, |
| 4426 | cur_bytes, read_flags, write_flags); |
| 4427 | qemu_co_mutex_lock(&s->lock); |
| 4428 | if (ret < 0) { |
| 4429 | goto fail; |
| 4430 | } |
| 4431 | |
| 4432 | ret = qcow2_handle_l2meta(bs, &l2meta, true); |
| 4433 | if (ret) { |
| 4434 | goto fail; |
| 4435 | } |
| 4436 | |
| 4437 | bytes -= cur_bytes; |
| 4438 | src_offset += cur_bytes; |
| 4439 | dst_offset += cur_bytes; |
| 4440 | } |
| 4441 | ret = 0; |
| 4442 | |
| 4443 | fail: |
| 4444 | qcow2_handle_l2meta(bs, &l2meta, false); |
| 4445 | |
| 4446 | qemu_co_mutex_unlock(&s->lock); |
| 4447 | |
| 4448 | trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
| 4449 | |
| 4450 | return ret; |
| 4451 | } |
| 4452 | |
| 4453 | static int coroutine_fn GRAPH_RDLOCK |
| 4454 | qcow2_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, |
| 4455 | PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) |
| 4456 | { |
| 4457 | ERRP_GUARD(); |
| 4458 | BDRVQcow2State *s = bs->opaque; |
| 4459 | uint64_t old_length; |
| 4460 | int64_t new_l1_size; |
| 4461 | int ret; |
| 4462 | QDict *options; |
| 4463 | |
| 4464 | if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA && |
| 4465 | prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL) |
| 4466 | { |
| 4467 | error_setg(errp, "Unsupported preallocation mode '%s'", |
| 4468 | PreallocMode_str(prealloc)); |
| 4469 | return -ENOTSUP; |
| 4470 | } |
| 4471 | |
| 4472 | if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) { |
| 4473 | error_setg(errp, "The new size must be a multiple of %u", |
| 4474 | (unsigned) BDRV_SECTOR_SIZE); |
| 4475 | return -EINVAL; |
| 4476 | } |
| 4477 | |
| 4478 | qemu_co_mutex_lock(&s->lock); |
| 4479 | |
| 4480 | /* |
| 4481 | * Even though we store snapshot size for all images, it was not |
| 4482 | * required until v3, so it is not safe to proceed for v2. |
| 4483 | */ |
| 4484 | if (s->nb_snapshots && s->qcow_version < 3) { |
| 4485 | error_setg(errp, "Can't resize a v2 image which has snapshots"); |
| 4486 | ret = -ENOTSUP; |
| 4487 | goto fail; |
| 4488 | } |
| 4489 | |
| 4490 | /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */ |
| 4491 | if (qcow2_truncate_bitmaps_check(bs, errp)) { |
| 4492 | ret = -ENOTSUP; |
| 4493 | goto fail; |
| 4494 | } |
| 4495 | |
| 4496 | old_length = bs->total_sectors * BDRV_SECTOR_SIZE; |
| 4497 | new_l1_size = size_to_l1(s, offset); |
| 4498 | |
| 4499 | if (offset < old_length) { |
| 4500 | int64_t last_cluster, old_file_size; |
| 4501 | if (prealloc != PREALLOC_MODE_OFF) { |
| 4502 | error_setg(errp, |
| 4503 | "Preallocation can't be used for shrinking an image"); |
| 4504 | ret = -EINVAL; |
| 4505 | goto fail; |
| 4506 | } |
| 4507 | |
| 4508 | ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size), |
| 4509 | old_length - ROUND_UP(offset, |
| 4510 | s->cluster_size), |
| 4511 | QCOW2_DISCARD_ALWAYS, true); |
| 4512 | if (ret < 0) { |
| 4513 | error_setg_errno(errp, -ret, "Failed to discard cropped clusters"); |
| 4514 | goto fail; |
| 4515 | } |
| 4516 | |
| 4517 | ret = qcow2_shrink_l1_table(bs, new_l1_size); |
| 4518 | if (ret < 0) { |
| 4519 | error_setg_errno(errp, -ret, |
| 4520 | "Failed to reduce the number of L2 tables"); |
| 4521 | goto fail; |
| 4522 | } |
| 4523 | |
| 4524 | ret = qcow2_shrink_reftable(bs); |
| 4525 | if (ret < 0) { |
| 4526 | error_setg_errno(errp, -ret, |
| 4527 | "Failed to discard unused refblocks"); |
| 4528 | goto fail; |
| 4529 | } |
| 4530 | |
| 4531 | old_file_size = bdrv_co_getlength(bs->file->bs); |
| 4532 | if (old_file_size < 0) { |
| 4533 | error_setg_errno(errp, -old_file_size, |
| 4534 | "Failed to inquire current file length"); |
| 4535 | ret = old_file_size; |
| 4536 | goto fail; |
| 4537 | } |
| 4538 | last_cluster = qcow2_get_last_cluster(bs, old_file_size); |
| 4539 | if (last_cluster < 0) { |
| 4540 | error_setg_errno(errp, -last_cluster, |
| 4541 | "Failed to find the last cluster"); |
| 4542 | ret = last_cluster; |
| 4543 | goto fail; |
| 4544 | } |
| 4545 | if ((last_cluster + 1) * s->cluster_size < old_file_size) { |
| 4546 | Error *local_err = NULL; |
| 4547 | |
| 4548 | /* |
| 4549 | * Do not pass @exact here: It will not help the user if |
| 4550 | * we get an error here just because they wanted to shrink |
| 4551 | * their qcow2 image (on a block device) with qemu-img. |
| 4552 | * (And on the qcow2 layer, the @exact requirement is |
| 4553 | * always fulfilled, so there is no need to pass it on.) |
| 4554 | */ |
| 4555 | bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size, |
| 4556 | false, PREALLOC_MODE_OFF, 0, &local_err); |
| 4557 | if (local_err) { |
| 4558 | warn_reportf_err(local_err, |
| 4559 | "Failed to truncate the tail of the image: "); |
| 4560 | } |
| 4561 | } |
| 4562 | } else { |
| 4563 | ret = qcow2_grow_l1_table(bs, new_l1_size, true); |
| 4564 | if (ret < 0) { |
| 4565 | error_setg_errno(errp, -ret, "Failed to grow the L1 table"); |
| 4566 | goto fail; |
| 4567 | } |
| 4568 | |
| 4569 | if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) { |
| 4570 | /* |
| 4571 | * When creating a qcow2 image with data-file-raw, we enforce |
| 4572 | * at least prealloc=metadata, so that the L1/L2 tables are |
| 4573 | * fully allocated and reading from the data file will return |
| 4574 | * the same data as reading from the qcow2 image. When the |
| 4575 | * image is grown, we must consequently preallocate the |
| 4576 | * metadata structures to cover the added area. |
| 4577 | */ |
| 4578 | prealloc = PREALLOC_MODE_METADATA; |
| 4579 | } |
| 4580 | } |
| 4581 | |
| 4582 | switch (prealloc) { |
| 4583 | case PREALLOC_MODE_OFF: |
| 4584 | if (has_data_file(bs)) { |
| 4585 | /* |
| 4586 | * If the caller wants an exact resize, the external data |
| 4587 | * file should be resized to the exact target size, too, |
| 4588 | * so we pass @exact here. |
| 4589 | */ |
| 4590 | ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0, |
| 4591 | errp); |
| 4592 | if (ret < 0) { |
| 4593 | goto fail; |
| 4594 | } |
| 4595 | } |
| 4596 | break; |
| 4597 | |
| 4598 | case PREALLOC_MODE_METADATA: |
| 4599 | ret = preallocate_co(bs, old_length, offset, prealloc, errp); |
| 4600 | if (ret < 0) { |
| 4601 | goto fail; |
| 4602 | } |
| 4603 | break; |
| 4604 | |
| 4605 | case PREALLOC_MODE_FALLOC: |
| 4606 | case PREALLOC_MODE_FULL: |
| 4607 | { |
| 4608 | int64_t allocation_start, host_offset, guest_offset; |
| 4609 | int64_t clusters_allocated; |
| 4610 | int64_t old_file_size, last_cluster, new_file_size; |
| 4611 | uint64_t nb_new_data_clusters, nb_new_l2_tables; |
| 4612 | bool subclusters_need_allocation = false; |
| 4613 | |
| 4614 | /* With a data file, preallocation means just allocating the metadata |
| 4615 | * and forwarding the truncate request to the data file */ |
| 4616 | if (has_data_file(bs)) { |
| 4617 | ret = preallocate_co(bs, old_length, offset, prealloc, errp); |
| 4618 | if (ret < 0) { |
| 4619 | goto fail; |
| 4620 | } |
| 4621 | break; |
| 4622 | } |
| 4623 | |
| 4624 | old_file_size = bdrv_co_getlength(bs->file->bs); |
| 4625 | if (old_file_size < 0) { |
| 4626 | error_setg_errno(errp, -old_file_size, |
| 4627 | "Failed to inquire current file length"); |
| 4628 | ret = old_file_size; |
| 4629 | goto fail; |
| 4630 | } |
| 4631 | |
| 4632 | last_cluster = qcow2_get_last_cluster(bs, old_file_size); |
| 4633 | if (last_cluster >= 0) { |
| 4634 | old_file_size = (last_cluster + 1) * s->cluster_size; |
| 4635 | } else { |
| 4636 | old_file_size = ROUND_UP(old_file_size, s->cluster_size); |
| 4637 | } |
| 4638 | |
| 4639 | nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) - |
| 4640 | start_of_cluster(s, old_length)) >> s->cluster_bits; |
| 4641 | |
| 4642 | /* This is an overestimation; we will not actually allocate space for |
| 4643 | * these in the file but just make sure the new refcount structures are |
| 4644 | * able to cover them so we will not have to allocate new refblocks |
| 4645 | * while entering the data blocks in the potentially new L2 tables. |
| 4646 | * (We do not actually care where the L2 tables are placed. Maybe they |
| 4647 | * are already allocated or they can be placed somewhere before |
| 4648 | * @old_file_size. It does not matter because they will be fully |
| 4649 | * allocated automatically, so they do not need to be covered by the |
| 4650 | * preallocation. All that matters is that we will not have to allocate |
| 4651 | * new refcount structures for them.) */ |
| 4652 | nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, |
| 4653 | s->cluster_size / l2_entry_size(s)); |
| 4654 | /* The cluster range may not be aligned to L2 boundaries, so add one L2 |
| 4655 | * table for a potential head/tail */ |
| 4656 | nb_new_l2_tables++; |
| 4657 | |
| 4658 | allocation_start = qcow2_refcount_area(bs, old_file_size, |
| 4659 | nb_new_data_clusters + |
| 4660 | nb_new_l2_tables, |
| 4661 | true, 0, 0); |
| 4662 | if (allocation_start < 0) { |
| 4663 | error_setg_errno(errp, -allocation_start, |
| 4664 | "Failed to resize refcount structures"); |
| 4665 | ret = allocation_start; |
| 4666 | goto fail; |
| 4667 | } |
| 4668 | |
| 4669 | clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start, |
| 4670 | nb_new_data_clusters); |
| 4671 | if (clusters_allocated < 0) { |
| 4672 | error_setg_errno(errp, -clusters_allocated, |
| 4673 | "Failed to allocate data clusters"); |
| 4674 | ret = clusters_allocated; |
| 4675 | goto fail; |
| 4676 | } |
| 4677 | |
| 4678 | assert(clusters_allocated == nb_new_data_clusters); |
| 4679 | |
| 4680 | /* Allocate the data area */ |
| 4681 | new_file_size = allocation_start + |
| 4682 | nb_new_data_clusters * s->cluster_size; |
| 4683 | /* |
| 4684 | * Image file grows, so @exact does not matter. |
| 4685 | * |
| 4686 | * If we need to zero out the new area, try first whether the protocol |
| 4687 | * driver can already take care of this. |
| 4688 | */ |
| 4689 | if (flags & BDRV_REQ_ZERO_WRITE) { |
| 4690 | ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, |
| 4691 | BDRV_REQ_ZERO_WRITE, NULL); |
| 4692 | if (ret >= 0) { |
| 4693 | flags &= ~BDRV_REQ_ZERO_WRITE; |
| 4694 | /* Ensure that we read zeroes and not backing file data */ |
| 4695 | subclusters_need_allocation = true; |
| 4696 | } |
| 4697 | } else { |
| 4698 | ret = -1; |
| 4699 | } |
| 4700 | if (ret < 0) { |
| 4701 | ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0, |
| 4702 | errp); |
| 4703 | } |
| 4704 | if (ret < 0) { |
| 4705 | error_prepend(errp, "Failed to resize underlying file: "); |
| 4706 | qcow2_free_clusters(bs, allocation_start, |
| 4707 | nb_new_data_clusters * s->cluster_size, |
| 4708 | QCOW2_DISCARD_OTHER); |
| 4709 | goto fail; |
| 4710 | } |
| 4711 | |
| 4712 | /* Create the necessary L2 entries */ |
| 4713 | host_offset = allocation_start; |
| 4714 | guest_offset = old_length; |
| 4715 | while (nb_new_data_clusters) { |
| 4716 | int64_t nb_clusters = MIN( |
| 4717 | nb_new_data_clusters, |
| 4718 | s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset)); |
| 4719 | unsigned cow_start_length = offset_into_cluster(s, guest_offset); |
| 4720 | QCowL2Meta allocation; |
| 4721 | guest_offset = start_of_cluster(s, guest_offset); |
| 4722 | allocation = (QCowL2Meta) { |
| 4723 | .offset = guest_offset, |
| 4724 | .alloc_offset = host_offset, |
| 4725 | .nb_clusters = nb_clusters, |
| 4726 | .cow_start = { |
| 4727 | .offset = 0, |
| 4728 | .nb_bytes = cow_start_length, |
| 4729 | }, |
| 4730 | .cow_end = { |
| 4731 | .offset = nb_clusters << s->cluster_bits, |
| 4732 | .nb_bytes = 0, |
| 4733 | }, |
| 4734 | .prealloc = !subclusters_need_allocation, |
| 4735 | }; |
| 4736 | qemu_co_queue_init(&allocation.dependent_requests); |
| 4737 | |
| 4738 | ret = qcow2_alloc_cluster_link_l2(bs, &allocation); |
| 4739 | if (ret < 0) { |
| 4740 | error_setg_errno(errp, -ret, "Failed to update L2 tables"); |
| 4741 | qcow2_free_clusters(bs, host_offset, |
| 4742 | nb_new_data_clusters * s->cluster_size, |
| 4743 | QCOW2_DISCARD_OTHER); |
| 4744 | goto fail; |
| 4745 | } |
| 4746 | |
| 4747 | guest_offset += nb_clusters * s->cluster_size; |
| 4748 | host_offset += nb_clusters * s->cluster_size; |
| 4749 | nb_new_data_clusters -= nb_clusters; |
| 4750 | } |
| 4751 | break; |
| 4752 | } |
| 4753 | |
| 4754 | default: |
| 4755 | g_assert_not_reached(); |
| 4756 | } |
| 4757 | |
| 4758 | if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { |
| 4759 | uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size); |
| 4760 | |
| 4761 | /* |
| 4762 | * Use zero clusters as much as we can. qcow2_subcluster_zeroize() |
| 4763 | * requires a subcluster-aligned start. The end may be unaligned if |
| 4764 | * it is at the end of the image (which it is here). |
| 4765 | */ |
| 4766 | if (offset > zero_start) { |
| 4767 | ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start, |
| 4768 | 0); |
| 4769 | if (ret < 0) { |
| 4770 | error_setg_errno(errp, -ret, "Failed to zero out new clusters"); |
| 4771 | goto fail; |
| 4772 | } |
| 4773 | } |
| 4774 | |
| 4775 | /* Write explicit zeros for the unaligned head */ |
| 4776 | if (zero_start > old_length) { |
| 4777 | uint64_t len = MIN(zero_start, offset) - old_length; |
| 4778 | uint8_t *buf = qemu_blockalign0(bs, len); |
| 4779 | QEMUIOVector qiov; |
| 4780 | qemu_iovec_init_buf(&qiov, buf, len); |
| 4781 | |
| 4782 | qemu_co_mutex_unlock(&s->lock); |
| 4783 | ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0); |
| 4784 | qemu_co_mutex_lock(&s->lock); |
| 4785 | |
| 4786 | qemu_vfree(buf); |
| 4787 | if (ret < 0) { |
| 4788 | error_setg_errno(errp, -ret, "Failed to zero out the new area"); |
| 4789 | goto fail; |
| 4790 | } |
| 4791 | } |
| 4792 | } |
| 4793 | |
| 4794 | if (prealloc != PREALLOC_MODE_OFF) { |
| 4795 | /* Flush metadata before actually changing the image size */ |
| 4796 | ret = qcow2_write_caches(bs); |
| 4797 | if (ret < 0) { |
| 4798 | error_setg_errno(errp, -ret, |
| 4799 | "Failed to flush the preallocated area to disk"); |
| 4800 | goto fail; |
| 4801 | } |
| 4802 | } |
| 4803 | |
| 4804 | bs->total_sectors = offset / BDRV_SECTOR_SIZE; |
| 4805 | |
| 4806 | /* write updated header.size */ |
| 4807 | offset = cpu_to_be64(offset); |
| 4808 | ret = bdrv_co_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
| 4809 | sizeof(offset), &offset, 0); |
| 4810 | if (ret < 0) { |
| 4811 | error_setg_errno(errp, -ret, "Failed to update the image size"); |
| 4812 | goto fail; |
| 4813 | } |
| 4814 | |
| 4815 | s->l1_vm_state_index = new_l1_size; |
| 4816 | |
| 4817 | /* Update cache sizes */ |
| 4818 | options = qdict_clone_shallow(bs->options); |
| 4819 | ret = qcow2_update_options(bs, options, s->flags, errp); |
| 4820 | qobject_unref(options); |
| 4821 | if (ret < 0) { |
| 4822 | goto fail; |
| 4823 | } |
| 4824 | ret = 0; |
| 4825 | fail: |
| 4826 | qemu_co_mutex_unlock(&s->lock); |
| 4827 | return ret; |
| 4828 | } |
| 4829 | |
| 4830 | static int coroutine_fn GRAPH_RDLOCK |
| 4831 | qcow2_co_pwritev_compressed_task(BlockDriverState *bs, |
| 4832 | uint64_t offset, uint64_t bytes, |
| 4833 | QEMUIOVector *qiov, size_t qiov_offset) |
| 4834 | { |
| 4835 | BDRVQcow2State *s = bs->opaque; |
| 4836 | int ret; |
| 4837 | ssize_t out_len; |
| 4838 | uint8_t *buf, *out_buf; |
| 4839 | uint64_t cluster_offset; |
| 4840 | |
| 4841 | assert(bytes == s->cluster_size || (bytes < s->cluster_size && |
| 4842 | (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))); |
| 4843 | |
| 4844 | buf = qemu_blockalign(bs, s->cluster_size); |
| 4845 | if (bytes < s->cluster_size) { |
| 4846 | /* Zero-pad last write if image size is not cluster aligned */ |
| 4847 | memset(buf + bytes, 0, s->cluster_size - bytes); |
| 4848 | } |
| 4849 | qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes); |
| 4850 | |
| 4851 | out_buf = g_malloc(s->cluster_size); |
| 4852 | |
| 4853 | out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1, |
| 4854 | buf, s->cluster_size); |
| 4855 | if (out_len == -ENOMEM) { |
| 4856 | /* could not compress: write normal cluster */ |
| 4857 | ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0); |
| 4858 | if (ret < 0) { |
| 4859 | goto fail; |
| 4860 | } |
| 4861 | goto success; |
| 4862 | } else if (out_len < 0) { |
| 4863 | ret = -EINVAL; |
| 4864 | goto fail; |
| 4865 | } |
| 4866 | |
| 4867 | qemu_co_mutex_lock(&s->lock); |
| 4868 | ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len, |
| 4869 | &cluster_offset); |
| 4870 | if (ret < 0) { |
| 4871 | qemu_co_mutex_unlock(&s->lock); |
| 4872 | goto fail; |
| 4873 | } |
| 4874 | |
| 4875 | ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true); |
| 4876 | qemu_co_mutex_unlock(&s->lock); |
| 4877 | if (ret < 0) { |
| 4878 | goto fail; |
| 4879 | } |
| 4880 | |
| 4881 | BLKDBG_CO_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED); |
| 4882 | ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0); |
| 4883 | if (ret < 0) { |
| 4884 | goto fail; |
| 4885 | } |
| 4886 | success: |
| 4887 | ret = 0; |
| 4888 | fail: |
| 4889 | qemu_vfree(buf); |
| 4890 | g_free(out_buf); |
| 4891 | return ret; |
| 4892 | } |
| 4893 | |
| 4894 | /* |
| 4895 | * This function can count as GRAPH_RDLOCK because |
| 4896 | * qcow2_co_pwritev_compressed_part() holds the graph lock and keeps it until |
| 4897 | * this coroutine has terminated. |
| 4898 | */ |
| 4899 | static int coroutine_fn GRAPH_RDLOCK |
| 4900 | qcow2_co_pwritev_compressed_task_entry(AioTask *task) |
| 4901 | { |
| 4902 | Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); |
| 4903 | |
| 4904 | assert(!t->subcluster_type && !t->l2meta); |
| 4905 | |
| 4906 | return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov, |
| 4907 | t->qiov_offset); |
| 4908 | } |
| 4909 | |
| 4910 | /* |
| 4911 | * XXX: put compressed sectors first, then all the cluster aligned |
| 4912 | * tables to avoid losing bytes in alignment |
| 4913 | */ |
| 4914 | static int coroutine_fn GRAPH_RDLOCK |
| 4915 | qcow2_co_pwritev_compressed_part(BlockDriverState *bs, |
| 4916 | int64_t offset, int64_t bytes, |
| 4917 | QEMUIOVector *qiov, size_t qiov_offset) |
| 4918 | { |
| 4919 | BDRVQcow2State *s = bs->opaque; |
| 4920 | AioTaskPool *aio = NULL; |
| 4921 | int ret = 0; |
| 4922 | |
| 4923 | if (has_data_file(bs)) { |
| 4924 | return -ENOTSUP; |
| 4925 | } |
| 4926 | |
| 4927 | if (bytes == 0) { |
| 4928 | /* |
| 4929 | * align end of file to a sector boundary to ease reading with |
| 4930 | * sector based I/Os |
| 4931 | */ |
| 4932 | int64_t len = bdrv_co_getlength(bs->file->bs); |
| 4933 | if (len < 0) { |
| 4934 | return len; |
| 4935 | } |
| 4936 | return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0, |
| 4937 | NULL); |
| 4938 | } |
| 4939 | |
| 4940 | if (offset_into_cluster(s, offset)) { |
| 4941 | return -EINVAL; |
| 4942 | } |
| 4943 | |
| 4944 | if (offset_into_cluster(s, bytes) && |
| 4945 | (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) { |
| 4946 | return -EINVAL; |
| 4947 | } |
| 4948 | |
| 4949 | while (bytes && aio_task_pool_status(aio) == 0) { |
| 4950 | uint64_t chunk_size = MIN(bytes, s->cluster_size); |
| 4951 | |
| 4952 | if (!aio && chunk_size != bytes) { |
| 4953 | aio = aio_task_pool_new(QCOW2_MAX_WORKERS); |
| 4954 | } |
| 4955 | |
| 4956 | ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry, |
| 4957 | 0, 0, offset, chunk_size, qiov, qiov_offset, NULL); |
| 4958 | if (ret < 0) { |
| 4959 | break; |
| 4960 | } |
| 4961 | qiov_offset += chunk_size; |
| 4962 | offset += chunk_size; |
| 4963 | bytes -= chunk_size; |
| 4964 | } |
| 4965 | |
| 4966 | if (aio) { |
| 4967 | aio_task_pool_wait_all(aio); |
| 4968 | if (ret == 0) { |
| 4969 | ret = aio_task_pool_status(aio); |
| 4970 | } |
| 4971 | g_free(aio); |
| 4972 | } |
| 4973 | |
| 4974 | return ret; |
| 4975 | } |
| 4976 | |
| 4977 | static int coroutine_fn GRAPH_RDLOCK |
| 4978 | qcow2_co_preadv_compressed(BlockDriverState *bs, |
| 4979 | uint64_t l2_entry, |
| 4980 | uint64_t offset, |
| 4981 | uint64_t bytes, |
| 4982 | QEMUIOVector *qiov, |
| 4983 | size_t qiov_offset) |
| 4984 | { |
| 4985 | BDRVQcow2State *s = bs->opaque; |
| 4986 | int ret = 0, csize; |
| 4987 | uint64_t coffset; |
| 4988 | uint8_t *buf, *out_buf; |
| 4989 | int offset_in_cluster = offset_into_cluster(s, offset); |
| 4990 | |
| 4991 | qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize); |
| 4992 | |
| 4993 | buf = g_try_malloc(csize); |
| 4994 | if (!buf) { |
| 4995 | return -ENOMEM; |
| 4996 | } |
| 4997 | |
| 4998 | out_buf = qemu_blockalign(bs, s->cluster_size); |
| 4999 | |
| 5000 | BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED); |
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