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1.1 ! root 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: #include "qemu-common.h" ! 25: #include "block_int.h" ! 26: #include "module.h" ! 27: #include <zlib.h> ! 28: #include "aes.h" ! 29: #include "block/qcow2.h" ! 30: ! 31: /* ! 32: Differences with QCOW: ! 33: ! 34: - Support for multiple incremental snapshots. ! 35: - Memory management by reference counts. ! 36: - Clusters which have a reference count of one have the bit ! 37: QCOW_OFLAG_COPIED to optimize write performance. ! 38: - Size of compressed clusters is stored in sectors to reduce bit usage ! 39: in the cluster offsets. ! 40: - Support for storing additional data (such as the VM state) in the ! 41: snapshots. ! 42: - If a backing store is used, the cluster size is not constrained ! 43: (could be backported to QCOW). ! 44: - L2 tables have always a size of one cluster. ! 45: */ ! 46: ! 47: ! 48: typedef struct { ! 49: uint32_t magic; ! 50: uint32_t len; ! 51: } QCowExtension; ! 52: #define QCOW_EXT_MAGIC_END 0 ! 53: #define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA ! 54: ! 55: ! 56: ! 57: static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) ! 58: { ! 59: const QCowHeader *cow_header = (const void *)buf; ! 60: ! 61: if (buf_size >= sizeof(QCowHeader) && ! 62: be32_to_cpu(cow_header->magic) == QCOW_MAGIC && ! 63: be32_to_cpu(cow_header->version) == QCOW_VERSION) ! 64: return 100; ! 65: else ! 66: return 0; ! 67: } ! 68: ! 69: ! 70: /* ! 71: * read qcow2 extension and fill bs ! 72: * start reading from start_offset ! 73: * finish reading upon magic of value 0 or when end_offset reached ! 74: * unknown magic is skipped (future extension this version knows nothing about) ! 75: * return 0 upon success, non-0 otherwise ! 76: */ ! 77: static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset, ! 78: uint64_t end_offset) ! 79: { ! 80: BDRVQcowState *s = bs->opaque; ! 81: QCowExtension ext; ! 82: uint64_t offset; ! 83: ! 84: #ifdef DEBUG_EXT ! 85: printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); ! 86: #endif ! 87: offset = start_offset; ! 88: while (offset < end_offset) { ! 89: ! 90: #ifdef DEBUG_EXT ! 91: /* Sanity check */ ! 92: if (offset > s->cluster_size) ! 93: printf("qcow_handle_extension: suspicious offset %lu\n", offset); ! 94: ! 95: printf("attemting to read extended header in offset %lu\n", offset); ! 96: #endif ! 97: ! 98: if (bdrv_pread(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) { ! 99: fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n", ! 100: (unsigned long long)offset); ! 101: return 1; ! 102: } ! 103: be32_to_cpus(&ext.magic); ! 104: be32_to_cpus(&ext.len); ! 105: offset += sizeof(ext); ! 106: #ifdef DEBUG_EXT ! 107: printf("ext.magic = 0x%x\n", ext.magic); ! 108: #endif ! 109: switch (ext.magic) { ! 110: case QCOW_EXT_MAGIC_END: ! 111: return 0; ! 112: ! 113: case QCOW_EXT_MAGIC_BACKING_FORMAT: ! 114: if (ext.len >= sizeof(bs->backing_format)) { ! 115: fprintf(stderr, "ERROR: ext_backing_format: len=%u too large" ! 116: " (>=%zu)\n", ! 117: ext.len, sizeof(bs->backing_format)); ! 118: return 2; ! 119: } ! 120: if (bdrv_pread(s->hd, offset , bs->backing_format, ! 121: ext.len) != ext.len) ! 122: return 3; ! 123: bs->backing_format[ext.len] = '\0'; ! 124: #ifdef DEBUG_EXT ! 125: printf("Qcow2: Got format extension %s\n", bs->backing_format); ! 126: #endif ! 127: offset += ((ext.len + 7) & ~7); ! 128: break; ! 129: ! 130: default: ! 131: /* unknown magic -- just skip it */ ! 132: offset += ((ext.len + 7) & ~7); ! 133: break; ! 134: } ! 135: } ! 136: ! 137: return 0; ! 138: } ! 139: ! 140: ! 141: static int qcow_open(BlockDriverState *bs, const char *filename, int flags) ! 142: { ! 143: BDRVQcowState *s = bs->opaque; ! 144: int len, i, shift, ret; ! 145: QCowHeader header; ! 146: uint64_t ext_end; ! 147: ! 148: ret = bdrv_file_open(&s->hd, filename, flags); ! 149: if (ret < 0) ! 150: return ret; ! 151: if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) ! 152: goto fail; ! 153: be32_to_cpus(&header.magic); ! 154: be32_to_cpus(&header.version); ! 155: be64_to_cpus(&header.backing_file_offset); ! 156: be32_to_cpus(&header.backing_file_size); ! 157: be64_to_cpus(&header.size); ! 158: be32_to_cpus(&header.cluster_bits); ! 159: be32_to_cpus(&header.crypt_method); ! 160: be64_to_cpus(&header.l1_table_offset); ! 161: be32_to_cpus(&header.l1_size); ! 162: be64_to_cpus(&header.refcount_table_offset); ! 163: be32_to_cpus(&header.refcount_table_clusters); ! 164: be64_to_cpus(&header.snapshots_offset); ! 165: be32_to_cpus(&header.nb_snapshots); ! 166: ! 167: if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION) ! 168: goto fail; ! 169: if (header.size <= 1 || ! 170: header.cluster_bits < MIN_CLUSTER_BITS || ! 171: header.cluster_bits > MAX_CLUSTER_BITS) ! 172: goto fail; ! 173: if (header.crypt_method > QCOW_CRYPT_AES) ! 174: goto fail; ! 175: s->crypt_method_header = header.crypt_method; ! 176: if (s->crypt_method_header) ! 177: bs->encrypted = 1; ! 178: s->cluster_bits = header.cluster_bits; ! 179: s->cluster_size = 1 << s->cluster_bits; ! 180: s->cluster_sectors = 1 << (s->cluster_bits - 9); ! 181: s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ ! 182: s->l2_size = 1 << s->l2_bits; ! 183: bs->total_sectors = header.size / 512; ! 184: s->csize_shift = (62 - (s->cluster_bits - 8)); ! 185: s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; ! 186: s->cluster_offset_mask = (1LL << s->csize_shift) - 1; ! 187: s->refcount_table_offset = header.refcount_table_offset; ! 188: s->refcount_table_size = ! 189: header.refcount_table_clusters << (s->cluster_bits - 3); ! 190: ! 191: s->snapshots_offset = header.snapshots_offset; ! 192: s->nb_snapshots = header.nb_snapshots; ! 193: ! 194: /* read the level 1 table */ ! 195: s->l1_size = header.l1_size; ! 196: shift = s->cluster_bits + s->l2_bits; ! 197: s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift; ! 198: /* the L1 table must contain at least enough entries to put ! 199: header.size bytes */ ! 200: if (s->l1_size < s->l1_vm_state_index) ! 201: goto fail; ! 202: s->l1_table_offset = header.l1_table_offset; ! 203: s->l1_table = qemu_mallocz( ! 204: align_offset(s->l1_size * sizeof(uint64_t), 512)); ! 205: if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != ! 206: s->l1_size * sizeof(uint64_t)) ! 207: goto fail; ! 208: for(i = 0;i < s->l1_size; i++) { ! 209: be64_to_cpus(&s->l1_table[i]); ! 210: } ! 211: /* alloc L2 cache */ ! 212: s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); ! 213: s->cluster_cache = qemu_malloc(s->cluster_size); ! 214: /* one more sector for decompressed data alignment */ ! 215: s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size ! 216: + 512); ! 217: s->cluster_cache_offset = -1; ! 218: ! 219: if (qcow2_refcount_init(bs) < 0) ! 220: goto fail; ! 221: ! 222: LIST_INIT(&s->cluster_allocs); ! 223: ! 224: /* read qcow2 extensions */ ! 225: if (header.backing_file_offset) ! 226: ext_end = header.backing_file_offset; ! 227: else ! 228: ext_end = s->cluster_size; ! 229: if (qcow_read_extensions(bs, sizeof(header), ext_end)) ! 230: goto fail; ! 231: ! 232: /* read the backing file name */ ! 233: if (header.backing_file_offset != 0) { ! 234: len = header.backing_file_size; ! 235: if (len > 1023) ! 236: len = 1023; ! 237: if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) ! 238: goto fail; ! 239: bs->backing_file[len] = '\0'; ! 240: } ! 241: if (qcow2_read_snapshots(bs) < 0) ! 242: goto fail; ! 243: ! 244: #ifdef DEBUG_ALLOC ! 245: qcow2_check_refcounts(bs); ! 246: #endif ! 247: return 0; ! 248: ! 249: fail: ! 250: qcow2_free_snapshots(bs); ! 251: qcow2_refcount_close(bs); ! 252: qemu_free(s->l1_table); ! 253: qemu_free(s->l2_cache); ! 254: qemu_free(s->cluster_cache); ! 255: qemu_free(s->cluster_data); ! 256: bdrv_delete(s->hd); ! 257: return -1; ! 258: } ! 259: ! 260: static int qcow_set_key(BlockDriverState *bs, const char *key) ! 261: { ! 262: BDRVQcowState *s = bs->opaque; ! 263: uint8_t keybuf[16]; ! 264: int len, i; ! 265: ! 266: memset(keybuf, 0, 16); ! 267: len = strlen(key); ! 268: if (len > 16) ! 269: len = 16; ! 270: /* XXX: we could compress the chars to 7 bits to increase ! 271: entropy */ ! 272: for(i = 0;i < len;i++) { ! 273: keybuf[i] = key[i]; ! 274: } ! 275: s->crypt_method = s->crypt_method_header; ! 276: ! 277: if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) ! 278: return -1; ! 279: if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) ! 280: return -1; ! 281: #if 0 ! 282: /* test */ ! 283: { ! 284: uint8_t in[16]; ! 285: uint8_t out[16]; ! 286: uint8_t tmp[16]; ! 287: for(i=0;i<16;i++) ! 288: in[i] = i; ! 289: AES_encrypt(in, tmp, &s->aes_encrypt_key); ! 290: AES_decrypt(tmp, out, &s->aes_decrypt_key); ! 291: for(i = 0; i < 16; i++) ! 292: printf(" %02x", tmp[i]); ! 293: printf("\n"); ! 294: for(i = 0; i < 16; i++) ! 295: printf(" %02x", out[i]); ! 296: printf("\n"); ! 297: } ! 298: #endif ! 299: return 0; ! 300: } ! 301: ! 302: static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, ! 303: int nb_sectors, int *pnum) ! 304: { ! 305: uint64_t cluster_offset; ! 306: ! 307: *pnum = nb_sectors; ! 308: cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum); ! 309: ! 310: return (cluster_offset != 0); ! 311: } ! 312: ! 313: /* handle reading after the end of the backing file */ ! 314: int qcow2_backing_read1(BlockDriverState *bs, ! 315: int64_t sector_num, uint8_t *buf, int nb_sectors) ! 316: { ! 317: int n1; ! 318: if ((sector_num + nb_sectors) <= bs->total_sectors) ! 319: return nb_sectors; ! 320: if (sector_num >= bs->total_sectors) ! 321: n1 = 0; ! 322: else ! 323: n1 = bs->total_sectors - sector_num; ! 324: memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1)); ! 325: return n1; ! 326: } ! 327: ! 328: typedef struct QCowAIOCB { ! 329: BlockDriverAIOCB common; ! 330: int64_t sector_num; ! 331: QEMUIOVector *qiov; ! 332: uint8_t *buf; ! 333: void *orig_buf; ! 334: int nb_sectors; ! 335: int n; ! 336: uint64_t cluster_offset; ! 337: uint8_t *cluster_data; ! 338: BlockDriverAIOCB *hd_aiocb; ! 339: struct iovec hd_iov; ! 340: QEMUIOVector hd_qiov; ! 341: QEMUBH *bh; ! 342: QCowL2Meta l2meta; ! 343: LIST_ENTRY(QCowAIOCB) next_depend; ! 344: } QCowAIOCB; ! 345: ! 346: static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) ! 347: { ! 348: QCowAIOCB *acb = (QCowAIOCB *)blockacb; ! 349: if (acb->hd_aiocb) ! 350: bdrv_aio_cancel(acb->hd_aiocb); ! 351: qemu_aio_release(acb); ! 352: } ! 353: ! 354: static AIOPool qcow_aio_pool = { ! 355: .aiocb_size = sizeof(QCowAIOCB), ! 356: .cancel = qcow_aio_cancel, ! 357: }; ! 358: ! 359: static void qcow_aio_read_cb(void *opaque, int ret); ! 360: static void qcow_aio_read_bh(void *opaque) ! 361: { ! 362: QCowAIOCB *acb = opaque; ! 363: qemu_bh_delete(acb->bh); ! 364: acb->bh = NULL; ! 365: qcow_aio_read_cb(opaque, 0); ! 366: } ! 367: ! 368: static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb) ! 369: { ! 370: if (acb->bh) ! 371: return -EIO; ! 372: ! 373: acb->bh = qemu_bh_new(cb, acb); ! 374: if (!acb->bh) ! 375: return -EIO; ! 376: ! 377: qemu_bh_schedule(acb->bh); ! 378: ! 379: return 0; ! 380: } ! 381: ! 382: static void qcow_aio_read_cb(void *opaque, int ret) ! 383: { ! 384: QCowAIOCB *acb = opaque; ! 385: BlockDriverState *bs = acb->common.bs; ! 386: BDRVQcowState *s = bs->opaque; ! 387: int index_in_cluster, n1; ! 388: ! 389: acb->hd_aiocb = NULL; ! 390: if (ret < 0) ! 391: goto done; ! 392: ! 393: /* post process the read buffer */ ! 394: if (!acb->cluster_offset) { ! 395: /* nothing to do */ ! 396: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { ! 397: /* nothing to do */ ! 398: } else { ! 399: if (s->crypt_method) { ! 400: qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, ! 401: acb->n, 0, ! 402: &s->aes_decrypt_key); ! 403: } ! 404: } ! 405: ! 406: acb->nb_sectors -= acb->n; ! 407: acb->sector_num += acb->n; ! 408: acb->buf += acb->n * 512; ! 409: ! 410: if (acb->nb_sectors == 0) { ! 411: /* request completed */ ! 412: ret = 0; ! 413: goto done; ! 414: } ! 415: ! 416: /* prepare next AIO request */ ! 417: acb->n = acb->nb_sectors; ! 418: acb->cluster_offset = ! 419: qcow2_get_cluster_offset(bs, acb->sector_num << 9, &acb->n); ! 420: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); ! 421: ! 422: if (!acb->cluster_offset) { ! 423: if (bs->backing_hd) { ! 424: /* read from the base image */ ! 425: n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num, ! 426: acb->buf, acb->n); ! 427: if (n1 > 0) { ! 428: acb->hd_iov.iov_base = (void *)acb->buf; ! 429: acb->hd_iov.iov_len = acb->n * 512; ! 430: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); ! 431: acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, ! 432: &acb->hd_qiov, acb->n, ! 433: qcow_aio_read_cb, acb); ! 434: if (acb->hd_aiocb == NULL) ! 435: goto done; ! 436: } else { ! 437: ret = qcow_schedule_bh(qcow_aio_read_bh, acb); ! 438: if (ret < 0) ! 439: goto done; ! 440: } ! 441: } else { ! 442: /* Note: in this case, no need to wait */ ! 443: memset(acb->buf, 0, 512 * acb->n); ! 444: ret = qcow_schedule_bh(qcow_aio_read_bh, acb); ! 445: if (ret < 0) ! 446: goto done; ! 447: } ! 448: } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { ! 449: /* add AIO support for compressed blocks ? */ ! 450: if (qcow2_decompress_cluster(s, acb->cluster_offset) < 0) ! 451: goto done; ! 452: memcpy(acb->buf, ! 453: s->cluster_cache + index_in_cluster * 512, 512 * acb->n); ! 454: ret = qcow_schedule_bh(qcow_aio_read_bh, acb); ! 455: if (ret < 0) ! 456: goto done; ! 457: } else { ! 458: if ((acb->cluster_offset & 511) != 0) { ! 459: ret = -EIO; ! 460: goto done; ! 461: } ! 462: ! 463: acb->hd_iov.iov_base = (void *)acb->buf; ! 464: acb->hd_iov.iov_len = acb->n * 512; ! 465: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); ! 466: acb->hd_aiocb = bdrv_aio_readv(s->hd, ! 467: (acb->cluster_offset >> 9) + index_in_cluster, ! 468: &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); ! 469: if (acb->hd_aiocb == NULL) ! 470: goto done; ! 471: } ! 472: ! 473: return; ! 474: done: ! 475: if (acb->qiov->niov > 1) { ! 476: qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); ! 477: qemu_vfree(acb->orig_buf); ! 478: } ! 479: acb->common.cb(acb->common.opaque, ret); ! 480: qemu_aio_release(acb); ! 481: } ! 482: ! 483: static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs, ! 484: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, ! 485: BlockDriverCompletionFunc *cb, void *opaque, int is_write) ! 486: { ! 487: QCowAIOCB *acb; ! 488: ! 489: acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); ! 490: if (!acb) ! 491: return NULL; ! 492: acb->hd_aiocb = NULL; ! 493: acb->sector_num = sector_num; ! 494: acb->qiov = qiov; ! 495: if (qiov->niov > 1) { ! 496: acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); ! 497: if (is_write) ! 498: qemu_iovec_to_buffer(qiov, acb->buf); ! 499: } else { ! 500: acb->buf = (uint8_t *)qiov->iov->iov_base; ! 501: } ! 502: acb->nb_sectors = nb_sectors; ! 503: acb->n = 0; ! 504: acb->cluster_offset = 0; ! 505: acb->l2meta.nb_clusters = 0; ! 506: LIST_INIT(&acb->l2meta.dependent_requests); ! 507: return acb; ! 508: } ! 509: ! 510: static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs, ! 511: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, ! 512: BlockDriverCompletionFunc *cb, void *opaque) ! 513: { ! 514: QCowAIOCB *acb; ! 515: ! 516: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); ! 517: if (!acb) ! 518: return NULL; ! 519: ! 520: qcow_aio_read_cb(acb, 0); ! 521: return &acb->common; ! 522: } ! 523: ! 524: static void qcow_aio_write_cb(void *opaque, int ret); ! 525: ! 526: static void run_dependent_requests(QCowL2Meta *m) ! 527: { ! 528: QCowAIOCB *req; ! 529: QCowAIOCB *next; ! 530: ! 531: /* Take the request off the list of running requests */ ! 532: if (m->nb_clusters != 0) { ! 533: LIST_REMOVE(m, next_in_flight); ! 534: } ! 535: ! 536: /* ! 537: * Restart all dependent requests. ! 538: * Can't use LIST_FOREACH here - the next link might not be the same ! 539: * any more after the callback (request could depend on a different ! 540: * request now) ! 541: */ ! 542: for (req = m->dependent_requests.lh_first; req != NULL; req = next) { ! 543: next = req->next_depend.le_next; ! 544: qcow_aio_write_cb(req, 0); ! 545: } ! 546: ! 547: /* Empty the list for the next part of the request */ ! 548: LIST_INIT(&m->dependent_requests); ! 549: } ! 550: ! 551: static void qcow_aio_write_cb(void *opaque, int ret) ! 552: { ! 553: QCowAIOCB *acb = opaque; ! 554: BlockDriverState *bs = acb->common.bs; ! 555: BDRVQcowState *s = bs->opaque; ! 556: int index_in_cluster; ! 557: const uint8_t *src_buf; ! 558: int n_end; ! 559: ! 560: acb->hd_aiocb = NULL; ! 561: ! 562: if (ret >= 0) { ! 563: ret = qcow2_alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta); ! 564: } ! 565: ! 566: run_dependent_requests(&acb->l2meta); ! 567: ! 568: if (ret < 0) ! 569: goto done; ! 570: ! 571: acb->nb_sectors -= acb->n; ! 572: acb->sector_num += acb->n; ! 573: acb->buf += acb->n * 512; ! 574: ! 575: if (acb->nb_sectors == 0) { ! 576: /* request completed */ ! 577: ret = 0; ! 578: goto done; ! 579: } ! 580: ! 581: index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); ! 582: n_end = index_in_cluster + acb->nb_sectors; ! 583: if (s->crypt_method && ! 584: n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors) ! 585: n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors; ! 586: ! 587: acb->cluster_offset = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9, ! 588: index_in_cluster, ! 589: n_end, &acb->n, &acb->l2meta); ! 590: ! 591: /* Need to wait for another request? If so, we are done for now. */ ! 592: if (!acb->cluster_offset && acb->l2meta.depends_on != NULL) { ! 593: LIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests, ! 594: acb, next_depend); ! 595: return; ! 596: } ! 597: ! 598: if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) { ! 599: ret = -EIO; ! 600: goto done; ! 601: } ! 602: if (s->crypt_method) { ! 603: if (!acb->cluster_data) { ! 604: acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS * ! 605: s->cluster_size); ! 606: } ! 607: qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, ! 608: acb->n, 1, &s->aes_encrypt_key); ! 609: src_buf = acb->cluster_data; ! 610: } else { ! 611: src_buf = acb->buf; ! 612: } ! 613: acb->hd_iov.iov_base = (void *)src_buf; ! 614: acb->hd_iov.iov_len = acb->n * 512; ! 615: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); ! 616: acb->hd_aiocb = bdrv_aio_writev(s->hd, ! 617: (acb->cluster_offset >> 9) + index_in_cluster, ! 618: &acb->hd_qiov, acb->n, ! 619: qcow_aio_write_cb, acb); ! 620: if (acb->hd_aiocb == NULL) ! 621: goto done; ! 622: ! 623: return; ! 624: ! 625: done: ! 626: if (acb->qiov->niov > 1) ! 627: qemu_vfree(acb->orig_buf); ! 628: acb->common.cb(acb->common.opaque, ret); ! 629: qemu_aio_release(acb); ! 630: } ! 631: ! 632: static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs, ! 633: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, ! 634: BlockDriverCompletionFunc *cb, void *opaque) ! 635: { ! 636: BDRVQcowState *s = bs->opaque; ! 637: QCowAIOCB *acb; ! 638: ! 639: s->cluster_cache_offset = -1; /* disable compressed cache */ ! 640: ! 641: acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); ! 642: if (!acb) ! 643: return NULL; ! 644: ! 645: qcow_aio_write_cb(acb, 0); ! 646: return &acb->common; ! 647: } ! 648: ! 649: static void qcow_close(BlockDriverState *bs) ! 650: { ! 651: BDRVQcowState *s = bs->opaque; ! 652: qemu_free(s->l1_table); ! 653: qemu_free(s->l2_cache); ! 654: qemu_free(s->cluster_cache); ! 655: qemu_free(s->cluster_data); ! 656: qcow2_refcount_close(bs); ! 657: bdrv_delete(s->hd); ! 658: } ! 659: ! 660: static int get_bits_from_size(size_t size) ! 661: { ! 662: int res = 0; ! 663: ! 664: if (size == 0) { ! 665: return -1; ! 666: } ! 667: ! 668: while (size != 1) { ! 669: /* Not a power of two */ ! 670: if (size & 1) { ! 671: return -1; ! 672: } ! 673: ! 674: size >>= 1; ! 675: res++; ! 676: } ! 677: ! 678: return res; ! 679: } ! 680: ! 681: static int qcow_create2(const char *filename, int64_t total_size, ! 682: const char *backing_file, const char *backing_format, ! 683: int flags, size_t cluster_size) ! 684: { ! 685: ! 686: int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; ! 687: int ref_clusters, backing_format_len = 0; ! 688: QCowHeader header; ! 689: uint64_t tmp, offset; ! 690: QCowCreateState s1, *s = &s1; ! 691: QCowExtension ext_bf = {0, 0}; ! 692: ! 693: ! 694: memset(s, 0, sizeof(*s)); ! 695: ! 696: fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); ! 697: if (fd < 0) ! 698: return -1; ! 699: memset(&header, 0, sizeof(header)); ! 700: header.magic = cpu_to_be32(QCOW_MAGIC); ! 701: header.version = cpu_to_be32(QCOW_VERSION); ! 702: header.size = cpu_to_be64(total_size * 512); ! 703: header_size = sizeof(header); ! 704: backing_filename_len = 0; ! 705: if (backing_file) { ! 706: if (backing_format) { ! 707: ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT; ! 708: backing_format_len = strlen(backing_format); ! 709: ext_bf.len = (backing_format_len + 7) & ~7; ! 710: header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7); ! 711: } ! 712: header.backing_file_offset = cpu_to_be64(header_size); ! 713: backing_filename_len = strlen(backing_file); ! 714: header.backing_file_size = cpu_to_be32(backing_filename_len); ! 715: header_size += backing_filename_len; ! 716: } ! 717: ! 718: /* Cluster size */ ! 719: s->cluster_bits = get_bits_from_size(cluster_size); ! 720: if (s->cluster_bits < MIN_CLUSTER_BITS || ! 721: s->cluster_bits > MAX_CLUSTER_BITS) ! 722: { ! 723: fprintf(stderr, "Cluster size must be a power of two between " ! 724: "%d and %dk\n", ! 725: 1 << MIN_CLUSTER_BITS, ! 726: 1 << (MAX_CLUSTER_BITS - 10)); ! 727: return -EINVAL; ! 728: } ! 729: s->cluster_size = 1 << s->cluster_bits; ! 730: ! 731: header.cluster_bits = cpu_to_be32(s->cluster_bits); ! 732: header_size = (header_size + 7) & ~7; ! 733: if (flags & BLOCK_FLAG_ENCRYPT) { ! 734: header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); ! 735: } else { ! 736: header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); ! 737: } ! 738: l2_bits = s->cluster_bits - 3; ! 739: shift = s->cluster_bits + l2_bits; ! 740: l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift); ! 741: offset = align_offset(header_size, s->cluster_size); ! 742: s->l1_table_offset = offset; ! 743: header.l1_table_offset = cpu_to_be64(s->l1_table_offset); ! 744: header.l1_size = cpu_to_be32(l1_size); ! 745: offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); ! 746: ! 747: s->refcount_table = qemu_mallocz(s->cluster_size); ! 748: ! 749: s->refcount_table_offset = offset; ! 750: header.refcount_table_offset = cpu_to_be64(offset); ! 751: header.refcount_table_clusters = cpu_to_be32(1); ! 752: offset += s->cluster_size; ! 753: s->refcount_block_offset = offset; ! 754: ! 755: /* count how many refcount blocks needed */ ! 756: tmp = offset >> s->cluster_bits; ! 757: ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1; ! 758: for (i=0; i < ref_clusters; i++) { ! 759: s->refcount_table[i] = cpu_to_be64(offset); ! 760: offset += s->cluster_size; ! 761: } ! 762: ! 763: s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size); ! 764: ! 765: /* update refcounts */ ! 766: qcow2_create_refcount_update(s, 0, header_size); ! 767: qcow2_create_refcount_update(s, s->l1_table_offset, ! 768: l1_size * sizeof(uint64_t)); ! 769: qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size); ! 770: qcow2_create_refcount_update(s, s->refcount_block_offset, ! 771: ref_clusters * s->cluster_size); ! 772: ! 773: /* write all the data */ ! 774: write(fd, &header, sizeof(header)); ! 775: if (backing_file) { ! 776: if (backing_format_len) { ! 777: char zero[16]; ! 778: int d = ext_bf.len - backing_format_len; ! 779: ! 780: memset(zero, 0, sizeof(zero)); ! 781: cpu_to_be32s(&ext_bf.magic); ! 782: cpu_to_be32s(&ext_bf.len); ! 783: write(fd, &ext_bf, sizeof(ext_bf)); ! 784: write(fd, backing_format, backing_format_len); ! 785: if (d>0) { ! 786: write(fd, zero, d); ! 787: } ! 788: } ! 789: write(fd, backing_file, backing_filename_len); ! 790: } ! 791: lseek(fd, s->l1_table_offset, SEEK_SET); ! 792: tmp = 0; ! 793: for(i = 0;i < l1_size; i++) { ! 794: write(fd, &tmp, sizeof(tmp)); ! 795: } ! 796: lseek(fd, s->refcount_table_offset, SEEK_SET); ! 797: write(fd, s->refcount_table, s->cluster_size); ! 798: ! 799: lseek(fd, s->refcount_block_offset, SEEK_SET); ! 800: write(fd, s->refcount_block, ref_clusters * s->cluster_size); ! 801: ! 802: qemu_free(s->refcount_table); ! 803: qemu_free(s->refcount_block); ! 804: close(fd); ! 805: return 0; ! 806: } ! 807: ! 808: static int qcow_create(const char *filename, QEMUOptionParameter *options) ! 809: { ! 810: const char *backing_file = NULL; ! 811: const char *backing_fmt = NULL; ! 812: uint64_t sectors = 0; ! 813: int flags = 0; ! 814: size_t cluster_size = 65536; ! 815: ! 816: /* Read out options */ ! 817: while (options && options->name) { ! 818: if (!strcmp(options->name, BLOCK_OPT_SIZE)) { ! 819: sectors = options->value.n / 512; ! 820: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { ! 821: backing_file = options->value.s; ! 822: } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { ! 823: backing_fmt = options->value.s; ! 824: } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { ! 825: flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0; ! 826: } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { ! 827: if (options->value.n) { ! 828: cluster_size = options->value.n; ! 829: } ! 830: } ! 831: options++; ! 832: } ! 833: ! 834: return qcow_create2(filename, sectors, backing_file, backing_fmt, flags, ! 835: cluster_size); ! 836: } ! 837: ! 838: static int qcow_make_empty(BlockDriverState *bs) ! 839: { ! 840: #if 0 ! 841: /* XXX: not correct */ ! 842: BDRVQcowState *s = bs->opaque; ! 843: uint32_t l1_length = s->l1_size * sizeof(uint64_t); ! 844: int ret; ! 845: ! 846: memset(s->l1_table, 0, l1_length); ! 847: if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) ! 848: return -1; ! 849: ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); ! 850: if (ret < 0) ! 851: return ret; ! 852: ! 853: l2_cache_reset(bs); ! 854: #endif ! 855: return 0; ! 856: } ! 857: ! 858: /* XXX: put compressed sectors first, then all the cluster aligned ! 859: tables to avoid losing bytes in alignment */ ! 860: static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, ! 861: const uint8_t *buf, int nb_sectors) ! 862: { ! 863: BDRVQcowState *s = bs->opaque; ! 864: z_stream strm; ! 865: int ret, out_len; ! 866: uint8_t *out_buf; ! 867: uint64_t cluster_offset; ! 868: ! 869: if (nb_sectors == 0) { ! 870: /* align end of file to a sector boundary to ease reading with ! 871: sector based I/Os */ ! 872: cluster_offset = bdrv_getlength(s->hd); ! 873: cluster_offset = (cluster_offset + 511) & ~511; ! 874: bdrv_truncate(s->hd, cluster_offset); ! 875: return 0; ! 876: } ! 877: ! 878: if (nb_sectors != s->cluster_sectors) ! 879: return -EINVAL; ! 880: ! 881: out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); ! 882: ! 883: /* best compression, small window, no zlib header */ ! 884: memset(&strm, 0, sizeof(strm)); ! 885: ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, ! 886: Z_DEFLATED, -12, ! 887: 9, Z_DEFAULT_STRATEGY); ! 888: if (ret != 0) { ! 889: qemu_free(out_buf); ! 890: return -1; ! 891: } ! 892: ! 893: strm.avail_in = s->cluster_size; ! 894: strm.next_in = (uint8_t *)buf; ! 895: strm.avail_out = s->cluster_size; ! 896: strm.next_out = out_buf; ! 897: ! 898: ret = deflate(&strm, Z_FINISH); ! 899: if (ret != Z_STREAM_END && ret != Z_OK) { ! 900: qemu_free(out_buf); ! 901: deflateEnd(&strm); ! 902: return -1; ! 903: } ! 904: out_len = strm.next_out - out_buf; ! 905: ! 906: deflateEnd(&strm); ! 907: ! 908: if (ret != Z_STREAM_END || out_len >= s->cluster_size) { ! 909: /* could not compress: write normal cluster */ ! 910: bdrv_write(bs, sector_num, buf, s->cluster_sectors); ! 911: } else { ! 912: cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, ! 913: sector_num << 9, out_len); ! 914: if (!cluster_offset) ! 915: return -1; ! 916: cluster_offset &= s->cluster_offset_mask; ! 917: if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) { ! 918: qemu_free(out_buf); ! 919: return -1; ! 920: } ! 921: } ! 922: ! 923: qemu_free(out_buf); ! 924: return 0; ! 925: } ! 926: ! 927: static void qcow_flush(BlockDriverState *bs) ! 928: { ! 929: BDRVQcowState *s = bs->opaque; ! 930: bdrv_flush(s->hd); ! 931: } ! 932: ! 933: static int64_t qcow_vm_state_offset(BDRVQcowState *s) ! 934: { ! 935: return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); ! 936: } ! 937: ! 938: static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) ! 939: { ! 940: BDRVQcowState *s = bs->opaque; ! 941: bdi->cluster_size = s->cluster_size; ! 942: bdi->vm_state_offset = qcow_vm_state_offset(s); ! 943: return 0; ! 944: } ! 945: ! 946: ! 947: static int qcow_check(BlockDriverState *bs) ! 948: { ! 949: return qcow2_check_refcounts(bs); ! 950: } ! 951: ! 952: #if 0 ! 953: static void dump_refcounts(BlockDriverState *bs) ! 954: { ! 955: BDRVQcowState *s = bs->opaque; ! 956: int64_t nb_clusters, k, k1, size; ! 957: int refcount; ! 958: ! 959: size = bdrv_getlength(s->hd); ! 960: nb_clusters = size_to_clusters(s, size); ! 961: for(k = 0; k < nb_clusters;) { ! 962: k1 = k; ! 963: refcount = get_refcount(bs, k); ! 964: k++; ! 965: while (k < nb_clusters && get_refcount(bs, k) == refcount) ! 966: k++; ! 967: printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1); ! 968: } ! 969: } ! 970: #endif ! 971: ! 972: static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf, ! 973: int64_t pos, int size) ! 974: { ! 975: BDRVQcowState *s = bs->opaque; ! 976: int growable = bs->growable; ! 977: ! 978: bs->growable = 1; ! 979: bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size); ! 980: bs->growable = growable; ! 981: ! 982: return size; ! 983: } ! 984: ! 985: static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf, ! 986: int64_t pos, int size) ! 987: { ! 988: BDRVQcowState *s = bs->opaque; ! 989: int growable = bs->growable; ! 990: int ret; ! 991: ! 992: bs->growable = 1; ! 993: ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size); ! 994: bs->growable = growable; ! 995: ! 996: return ret; ! 997: } ! 998: ! 999: static QEMUOptionParameter qcow_create_options[] = { ! 1000: { ! 1001: .name = BLOCK_OPT_SIZE, ! 1002: .type = OPT_SIZE, ! 1003: .help = "Virtual disk size" ! 1004: }, ! 1005: { ! 1006: .name = BLOCK_OPT_BACKING_FILE, ! 1007: .type = OPT_STRING, ! 1008: .help = "File name of a base image" ! 1009: }, ! 1010: { ! 1011: .name = BLOCK_OPT_BACKING_FMT, ! 1012: .type = OPT_STRING, ! 1013: .help = "Image format of the base image" ! 1014: }, ! 1015: { ! 1016: .name = BLOCK_OPT_ENCRYPT, ! 1017: .type = OPT_FLAG, ! 1018: .help = "Encrypt the image" ! 1019: }, ! 1020: { ! 1021: .name = BLOCK_OPT_CLUSTER_SIZE, ! 1022: .type = OPT_SIZE, ! 1023: .help = "qcow2 cluster size" ! 1024: }, ! 1025: { NULL } ! 1026: }; ! 1027: ! 1028: static BlockDriver bdrv_qcow2 = { ! 1029: .format_name = "qcow2", ! 1030: .instance_size = sizeof(BDRVQcowState), ! 1031: .bdrv_probe = qcow_probe, ! 1032: .bdrv_open = qcow_open, ! 1033: .bdrv_close = qcow_close, ! 1034: .bdrv_create = qcow_create, ! 1035: .bdrv_flush = qcow_flush, ! 1036: .bdrv_is_allocated = qcow_is_allocated, ! 1037: .bdrv_set_key = qcow_set_key, ! 1038: .bdrv_make_empty = qcow_make_empty, ! 1039: ! 1040: .bdrv_aio_readv = qcow_aio_readv, ! 1041: .bdrv_aio_writev = qcow_aio_writev, ! 1042: .bdrv_write_compressed = qcow_write_compressed, ! 1043: ! 1044: .bdrv_snapshot_create = qcow2_snapshot_create, ! 1045: .bdrv_snapshot_goto = qcow2_snapshot_goto, ! 1046: .bdrv_snapshot_delete = qcow2_snapshot_delete, ! 1047: .bdrv_snapshot_list = qcow2_snapshot_list, ! 1048: .bdrv_get_info = qcow_get_info, ! 1049: ! 1050: .bdrv_save_vmstate = qcow_save_vmstate, ! 1051: .bdrv_load_vmstate = qcow_load_vmstate, ! 1052: ! 1053: .create_options = qcow_create_options, ! 1054: .bdrv_check = qcow_check, ! 1055: }; ! 1056: ! 1057: static void bdrv_qcow2_init(void) ! 1058: { ! 1059: bdrv_register(&bdrv_qcow2); ! 1060: } ! 1061: ! 1062: block_init(bdrv_qcow2_init);
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