block-vmdk.c

   1 /*
   2  * Block driver for the VMDK format
   3  *
   4  * Copyright (c) 2004 Fabrice Bellard
   5  * Copyright (c) 2005 Filip Navara
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include "vl.h"
  27 #include "block_int.h"
  28
  29 #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
  30 #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
  31
  32 typedef struct {
  33     uint32_t version;
  34     uint32_t flags;
  35     uint32_t disk_sectors;
  36     uint32_t granularity;
  37     uint32_t l1dir_offset;
  38     uint32_t l1dir_size;
  39     uint32_t file_sectors;
  40     uint32_t cylinders;
  41     uint32_t heads;
  42     uint32_t sectors_per_track;
  43 } VMDK3Header;
  44
  45 typedef struct {
  46     uint32_t version;
  47     uint32_t flags;
  48     int64_t capacity;
  49     int64_t granularity;
  50     int64_t desc_offset;
  51     int64_t desc_size;
  52     int32_t num_gtes_per_gte;
  53     int64_t rgd_offset;
  54     int64_t gd_offset;
  55     int64_t grain_offset;
  56     char filler[1];
  57     char check_bytes[4];
  58 } __attribute__((packed)) VMDK4Header;
  59
  60 #define L2_CACHE_SIZE 16
  61
  62 typedef struct BDRVVmdkState {
  63     BlockDriverState *hd;
  64     int64_t l1_table_offset;
  65     int64_t l1_backup_table_offset;
  66     uint32_t *l1_table;
  67     uint32_t *l1_backup_table;
  68     unsigned int l1_size;
  69     uint32_t l1_entry_sectors;
  70
  71     unsigned int l2_size;
  72     uint32_t *l2_cache;
  73     uint32_t l2_cache_offsets[L2_CACHE_SIZE];
  74     uint32_t l2_cache_counts[L2_CACHE_SIZE];
  75
  76     unsigned int cluster_sectors;
  77     uint32_t parent_cid;
  78     int is_parent;
  79 } BDRVVmdkState;
  80
  81 typedef struct VmdkMetaData {
  82     uint32_t offset;
  83     unsigned int l1_index;
  84     unsigned int l2_index;
  85     unsigned int l2_offset;
  86     int valid;
  87 } VmdkMetaData;
  88
  89 typedef struct ActiveBDRVState{
  90     BlockDriverState *hd;            // active image handler
  91     uint64_t cluster_offset;         // current write offset
  92 }ActiveBDRVState;
  93
  94 static ActiveBDRVState activeBDRV;
  95
  96
  97 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
  98 {
  99     uint32_t magic;
 100
 101     if (buf_size < 4)
 102         return 0;
 103     magic = be32_to_cpu(*(uint32_t *)buf);
 104     if (magic == VMDK3_MAGIC ||
 105         magic == VMDK4_MAGIC)
 106         return 100;
 107     else
 108         return 0;
 109 }
 110
 111 #define CHECK_CID 1
 112
 113 #define SECTOR_SIZE 512
 114 #define DESC_SIZE 20*SECTOR_SIZE        // 20 sectors of 512 bytes each
 115 #define HEADER_SIZE 512                         // first sector of 512 bytes
 116
 117 static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
 118 {
 119     BDRVVmdkState *s = bs->opaque;
 120     char desc[DESC_SIZE];
 121     uint32_t cid;
 122     char *p_name, *cid_str;
 123     size_t cid_str_size;
 124
 125     /* the descriptor offset = 0x200 */
 126     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 127         return 0;
 128
 129     if (parent) {
 130         cid_str = "parentCID";
 131         cid_str_size = sizeof("parentCID");
 132     } else {
 133         cid_str = "CID";
 134         cid_str_size = sizeof("CID");
 135     }
 136
 137     if ((p_name = strstr(desc,cid_str)) != 0) {
 138         p_name += cid_str_size;
 139         sscanf(p_name,"%x",&cid);
 140     }
 141
 142     return cid;
 143 }
 144
 145 static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
 146 {
 147     BDRVVmdkState *s = bs->opaque;
 148     char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
 149     char *p_name, *tmp_str;
 150
 151     /* the descriptor offset = 0x200 */
 152     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 153         return -1;
 154
 155     tmp_str = strstr(desc,"parentCID");
 156     strcpy(tmp_desc, tmp_str);
 157     if ((p_name = strstr(desc,"CID")) != 0) {
 158         p_name += sizeof("CID");
 159         sprintf(p_name,"%x\n",cid);
 160         strcat(desc,tmp_desc);
 161     }
 162
 163     if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 164         return -1;
 165     return 0;
 166 }
 167
 168 static int vmdk_is_cid_valid(BlockDriverState *bs)
 169 {
 170 #ifdef CHECK_CID
 171     BDRVVmdkState *s = bs->opaque;
 172     BlockDriverState *p_bs = s->hd->backing_hd;
 173     uint32_t cur_pcid;
 174
 175     if (p_bs) {
 176         cur_pcid = vmdk_read_cid(p_bs,0);
 177         if (s->parent_cid != cur_pcid)
 178             // CID not valid
 179             return 0;
 180     }
 181 #endif
 182     // CID valid
 183     return 1;
 184 }
 185
 186 static int vmdk_snapshot_create(const char *filename, const char *backing_file)
 187 {
 188     int snp_fd, p_fd;
 189     uint32_t p_cid;
 190     char *p_name, *gd_buf, *rgd_buf;
 191     const char *real_filename, *temp_str;
 192     VMDK4Header header;
 193     uint32_t gde_entries, gd_size;
 194     int64_t gd_offset, rgd_offset, capacity, gt_size;
 195     char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
 196     char *desc_template =
 197     "# Disk DescriptorFile\n"
 198     "version=1\n"
 199     "CID=%x\n"
 200     "parentCID=%x\n"
 201     "createType=\"monolithicSparse\"\n"
 202     "parentFileNameHint=\"%s\"\n"
 203     "\n"
 204     "# Extent description\n"
 205     "RW %lu SPARSE \"%s\"\n"
 206     "\n"
 207     "# The Disk Data Base \n"
 208     "#DDB\n"
 209     "\n";
 210
 211     snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
 212     if (snp_fd < 0)
 213         return -1;
 214     p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
 215     if (p_fd < 0) {
 216         close(snp_fd);
 217         return -1;
 218     }
 219
 220     /* read the header */
 221     if (lseek(p_fd, 0x0, SEEK_SET) == -1)
 222         goto fail;
 223     if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)
 224         goto fail;
 225
 226     /* write the header */
 227     if (lseek(snp_fd, 0x0, SEEK_SET) == -1)
 228         goto fail;
 229     if (write(snp_fd, hdr, HEADER_SIZE) == -1)
 230         goto fail;
 231
 232     memset(&header, 0, sizeof(header));
 233     memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
 234
 235     ftruncate(snp_fd, header.grain_offset << 9);
 236     /* the descriptor offset = 0x200 */
 237     if (lseek(p_fd, 0x200, SEEK_SET) == -1)
 238         goto fail;
 239     if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)
 240         goto fail;
 241
 242     if ((p_name = strstr(p_desc,"CID")) != 0) {
 243         p_name += sizeof("CID");
 244         sscanf(p_name,"%x",&p_cid);
 245     }
 246
 247     real_filename = filename;
 248     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 249         real_filename = temp_str + 1;
 250     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 251         real_filename = temp_str + 1;
 252     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 253         real_filename = temp_str + 1;
 254
 255     sprintf(s_desc, desc_template, p_cid, p_cid, backing_file
 256             , (uint32_t)header.capacity, real_filename);
 257
 258     /* write the descriptor */
 259     if (lseek(snp_fd, 0x200, SEEK_SET) == -1)
 260         goto fail;
 261     if (write(snp_fd, s_desc, strlen(s_desc)) == -1)
 262         goto fail;
 263
 264     gd_offset = header.gd_offset * SECTOR_SIZE;     // offset of GD table
 265     rgd_offset = header.rgd_offset * SECTOR_SIZE;   // offset of RGD table
 266     capacity = header.capacity * SECTOR_SIZE;       // Extent size
 267     /*
 268      * Each GDE span 32M disk, means:
 269      * 512 GTE per GT, each GTE points to grain
 270      */
 271     gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
 272     if (!gt_size)
 273         goto fail;
 274     gde_entries = (uint32_t)(capacity / gt_size);  // number of gde/rgde
 275     gd_size = gde_entries * sizeof(uint32_t);
 276
 277     /* write RGD */
 278     rgd_buf = qemu_malloc(gd_size);
 279     if (!rgd_buf)
 280         goto fail;
 281     if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)
 282         goto fail_rgd;
 283     if (read(p_fd, rgd_buf, gd_size) != gd_size)
 284         goto fail_rgd;
 285     if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)
 286         goto fail_rgd;
 287     if (write(snp_fd, rgd_buf, gd_size) == -1)
 288         goto fail_rgd;
 289     qemu_free(rgd_buf);
 290
 291     /* write GD */
 292     gd_buf = qemu_malloc(gd_size);
 293     if (!gd_buf)
 294         goto fail_rgd;
 295     if (lseek(p_fd, gd_offset, SEEK_SET) == -1)
 296         goto fail_gd;
 297     if (read(p_fd, gd_buf, gd_size) != gd_size)
 298         goto fail_gd;
 299     if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)
 300         goto fail_gd;
 301     if (write(snp_fd, gd_buf, gd_size) == -1)
 302         goto fail_gd;
 303     qemu_free(gd_buf);
 304
 305     close(p_fd);
 306     close(snp_fd);
 307     return 0;
 308
 309     fail_gd:
 310     qemu_free(gd_buf);
 311     fail_rgd:
 312     qemu_free(rgd_buf);
 313     fail:
 314     close(p_fd);
 315     close(snp_fd);
 316     return -1;
 317 }
 318
 319 static void vmdk_parent_close(BlockDriverState *bs)
 320 {
 321     if (bs->backing_hd)
 322         bdrv_close(bs->backing_hd);
 323 }
 324
 325 int parent_open = 0;
 326 static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
 327 {
 328     BDRVVmdkState *s = bs->opaque;
 329     char *p_name;
 330     char desc[DESC_SIZE];
 331     char parent_img_name[1024];
 332
 333     /* the descriptor offset = 0x200 */
 334     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 335         return -1;
 336
 337     if ((p_name = strstr(desc,"parentFileNameHint")) != 0) {
 338         char *end_name;
 339         struct stat file_buf;
 340
 341         p_name += sizeof("parentFileNameHint") + 1;
 342         if ((end_name = strchr(p_name,'\"')) == 0)
 343             return -1;
 344
 345         strncpy(s->hd->backing_file, p_name, end_name - p_name);
 346         if (stat(s->hd->backing_file, &file_buf) != 0) {
 347             path_combine(parent_img_name, sizeof(parent_img_name),
 348                          filename, s->hd->backing_file);
 349         } else {
 350             strcpy(parent_img_name, s->hd->backing_file);
 351         }
 352
 353         s->hd->backing_hd = bdrv_new("");
 354         if (!s->hd->backing_hd) {
 355             failure:
 356             bdrv_close(s->hd);
 357             return -1;
 358         }
 359         parent_open = 1;
 360         if (bdrv_open(s->hd->backing_hd, parent_img_name, BDRV_O_RDONLY) < 0)
 361             goto failure;
 362         parent_open = 0;
 363     }
 364
 365     return 0;
 366 }
 367
 368 static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
 369 {
 370     BDRVVmdkState *s = bs->opaque;
 371     uint32_t magic;
 372     int l1_size, i, ret;
 373
 374     if (parent_open)
 375         // Parent must be opened as RO.
 376         flags = BDRV_O_RDONLY;
 377     fprintf(stderr, "(VMDK) image open: flags=0x%x filename=%s\n", flags, bs->filename);
 378
 379     ret = bdrv_file_open(&s->hd, filename, flags);
 380     if (ret < 0)
 381         return ret;
 382     if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
 383         goto fail;
 384
 385     magic = be32_to_cpu(magic);
 386     if (magic == VMDK3_MAGIC) {
 387         VMDK3Header header;
 388
 389         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 390             goto fail;
 391         s->cluster_sectors = le32_to_cpu(header.granularity);
 392         s->l2_size = 1 << 9;
 393         s->l1_size = 1 << 6;
 394         bs->total_sectors = le32_to_cpu(header.disk_sectors);
 395         s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
 396         s->l1_backup_table_offset = 0;
 397         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 398     } else if (magic == VMDK4_MAGIC) {
 399         VMDK4Header header;
 400
 401         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 402             goto fail;
 403         bs->total_sectors = le64_to_cpu(header.capacity);
 404         s->cluster_sectors = le64_to_cpu(header.granularity);
 405         s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
 406         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 407         if (s->l1_entry_sectors <= 0)
 408             goto fail;
 409         s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
 410             / s->l1_entry_sectors;
 411         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
 412         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
 413
 414         if (parent_open)
 415             s->is_parent = 1;
 416         else
 417             s->is_parent = 0;
 418
 419         // try to open parent images, if exist
 420         if (vmdk_parent_open(bs, filename) != 0)
 421             goto fail;
 422         // write the CID once after the image creation
 423         s->parent_cid = vmdk_read_cid(bs,1);
 424     } else {
 425         goto fail;
 426     }
 427
 428     /* read the L1 table */
 429     l1_size = s->l1_size * sizeof(uint32_t);
 430     s->l1_table = qemu_malloc(l1_size);
 431     if (!s->l1_table)
 432         goto fail;
 433     if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
 434         goto fail;
 435     for(i = 0; i < s->l1_size; i++) {
 436         le32_to_cpus(&s->l1_table[i]);
 437     }
 438
 439     if (s->l1_backup_table_offset) {
 440         s->l1_backup_table = qemu_malloc(l1_size);
 441         if (!s->l1_backup_table)
 442             goto fail;
 443         if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
 444             goto fail;
 445         for(i = 0; i < s->l1_size; i++) {
 446             le32_to_cpus(&s->l1_backup_table[i]);
 447         }
 448     }
 449
 450     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
 451     if (!s->l2_cache)
 452         goto fail;
 453     return 0;
 454  fail:
 455     qemu_free(s->l1_backup_table);
 456     qemu_free(s->l1_table);
 457     qemu_free(s->l2_cache);
 458     bdrv_delete(s->hd);
 459     return -1;
 460 }
 461
 462 static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
 463                                    uint64_t offset, int allocate);
 464
 465 static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
 466                              uint64_t offset, int allocate)
 467 {
 468     uint64_t parent_cluster_offset;
 469     BDRVVmdkState *s = bs->opaque;
 470     uint8_t  whole_grain[s->cluster_sectors*512];        // 128 sectors * 512 bytes each = grain size 64KB
 471
 472     // we will be here if it's first write on non-exist grain(cluster).
 473     // try to read from parent image, if exist
 474     if (s->hd->backing_hd) {
 475         BDRVVmdkState *ps = s->hd->backing_hd->opaque;
 476
 477         if (!vmdk_is_cid_valid(bs))
 478             return -1;
 479
 480         parent_cluster_offset = get_cluster_offset(s->hd->backing_hd, NULL, offset, allocate);
 481
 482         if (parent_cluster_offset) {
 483             BDRVVmdkState *act_s = activeBDRV.hd->opaque;
 484
 485             if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)
 486                 return -1;
 487
 488             //Write grain only into the active image
 489             if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))
 490                 return -1;
 491         }
 492     }
 493     return 0;
 494 }
 495
 496 static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
 497 {
 498     BDRVVmdkState *s = bs->opaque;
 499
 500     /* update L2 table */
 501     if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
 502                     &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
 503         return -1;
 504     /* update backup L2 table */
 505     if (s->l1_backup_table_offset != 0) {
 506         m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
 507         if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
 508                         &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
 509             return -1;
 510     }
 511
 512     return 0;
 513 }
 514
 515 static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
 516                                    uint64_t offset, int allocate)
 517 {
 518     BDRVVmdkState *s = bs->opaque;
 519     unsigned int l1_index, l2_offset, l2_index;
 520     int min_index, i, j;
 521     uint32_t min_count, *l2_table, tmp = 0;
 522     uint64_t cluster_offset;
 523
 524     if (m_data)
 525         m_data->valid = 0;
 526
 527     l1_index = (offset >> 9) / s->l1_entry_sectors;
 528     if (l1_index >= s->l1_size)
 529         return 0;
 530     l2_offset = s->l1_table[l1_index];
 531     if (!l2_offset)
 532         return 0;
 533     for(i = 0; i < L2_CACHE_SIZE; i++) {
 534         if (l2_offset == s->l2_cache_offsets[i]) {
 535             /* increment the hit count */
 536             if (++s->l2_cache_counts[i] == 0xffffffff) {
 537                 for(j = 0; j < L2_CACHE_SIZE; j++) {
 538                     s->l2_cache_counts[j] >>= 1;
 539                 }
 540             }
 541             l2_table = s->l2_cache + (i * s->l2_size);
 542             goto found;
 543         }
 544     }
 545     /* not found: load a new entry in the least used one */
 546     min_index = 0;
 547     min_count = 0xffffffff;
 548     for(i = 0; i < L2_CACHE_SIZE; i++) {
 549         if (s->l2_cache_counts[i] < min_count) {
 550             min_count = s->l2_cache_counts[i];
 551             min_index = i;
 552         }
 553     }
 554     l2_table = s->l2_cache + (min_index * s->l2_size);
 555     if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
 556                                                                         s->l2_size * sizeof(uint32_t))
 557         return 0;
 558
 559     s->l2_cache_offsets[min_index] = l2_offset;
 560     s->l2_cache_counts[min_index] = 1;
 561  found:
 562     l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
 563     cluster_offset = le32_to_cpu(l2_table[l2_index]);
 564
 565     if (!cluster_offset) {
 566         if (!allocate)
 567             return 0;
 568         // Avoid the L2 tables update for the images that have snapshots.
 569         if (!s->is_parent) {
 570             cluster_offset = bdrv_getlength(s->hd);
 571             bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
 572
 573             cluster_offset >>= 9;
 574             tmp = cpu_to_le32(cluster_offset);
 575             l2_table[l2_index] = tmp;
 576             // Save the active image state
 577             activeBDRV.cluster_offset = cluster_offset;
 578             activeBDRV.hd = bs;
 579         }
 580         /* First of all we write grain itself, to avoid race condition
 581          * that may to corrupt the image.
 582          * This problem may occur because of insufficient space on host disk
 583          * or inappropriate VM shutdown.
 584          */
 585         if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
 586             return 0;
 587
 588         if (m_data) {
 589             m_data->offset = tmp;
 590             m_data->l1_index = l1_index;
 591             m_data->l2_index = l2_index;
 592             m_data->l2_offset = l2_offset;
 593             m_data->valid = 1;
 594         }
 595     }
 596     cluster_offset <<= 9;
 597     return cluster_offset;
 598 }
 599
 600 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
 601                              int nb_sectors, int *pnum)
 602 {
 603     BDRVVmdkState *s = bs->opaque;
 604     int index_in_cluster, n;
 605     uint64_t cluster_offset;
 606
 607     cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
 608     index_in_cluster = sector_num % s->cluster_sectors;
 609     n = s->cluster_sectors - index_in_cluster;
 610     if (n > nb_sectors)
 611         n = nb_sectors;
 612     *pnum = n;
 613     return (cluster_offset != 0);
 614 }
 615
 616 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
 617                     uint8_t *buf, int nb_sectors)
 618 {
 619     BDRVVmdkState *s = bs->opaque;
 620     int index_in_cluster, n, ret;
 621     uint64_t cluster_offset;
 622
 623     while (nb_sectors > 0) {
 624         cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
 625         index_in_cluster = sector_num % s->cluster_sectors;
 626         n = s->cluster_sectors - index_in_cluster;
 627         if (n > nb_sectors)
 628             n = nb_sectors;
 629         if (!cluster_offset) {
 630             // try to read from parent image, if exist
 631             if (s->hd->backing_hd) {
 632                 if (!vmdk_is_cid_valid(bs))
 633                     return -1;
 634                 ret = bdrv_read(s->hd->backing_hd, sector_num, buf, n);
 635                 if (ret < 0)
 636                     return -1;
 637             } else {
 638                 memset(buf, 0, 512 * n);
 639             }
 640         } else {
 641             if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 642                 return -1;
 643         }
 644         nb_sectors -= n;
 645         sector_num += n;
 646         buf += n * 512;
 647     }
 648     return 0;
 649 }
 650
 651 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
 652                      const uint8_t *buf, int nb_sectors)
 653 {
 654     BDRVVmdkState *s = bs->opaque;
 655     VmdkMetaData m_data;
 656     int index_in_cluster, n;
 657     uint64_t cluster_offset;
 658     static int cid_update = 0;
 659
 660     if (sector_num > bs->total_sectors) {
 661         fprintf(stderr,
 662                 "(VMDK) Wrong offset: sector_num=0x%llx total_sectors=0x%llx\n",
 663                 sector_num, bs->total_sectors);
 664         return -1;
 665     }
 666
 667     while (nb_sectors > 0) {
 668         index_in_cluster = sector_num & (s->cluster_sectors - 1);
 669         n = s->cluster_sectors - index_in_cluster;
 670         if (n > nb_sectors)
 671             n = nb_sectors;
 672         cluster_offset = get_cluster_offset(bs, &m_data, sector_num << 9, 1);
 673         if (!cluster_offset)
 674             return -1;
 675
 676         if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 677             return -1;
 678         if (m_data.valid) {
 679             /* update L2 tables */
 680             if (vmdk_L2update(bs, &m_data) == -1)
 681                 return -1;
 682         }
 683         nb_sectors -= n;
 684         sector_num += n;
 685         buf += n * 512;
 686
 687         // update CID on the first write every time the virtual disk is opened
 688         if (!cid_update) {
 689             vmdk_write_cid(bs, time(NULL));
 690             cid_update++;
 691         }
 692     }
 693     return 0;
 694 }
 695
 696 static int vmdk_create(const char *filename, int64_t total_size,
 697                        const char *backing_file, int flags)
 698 {
 699     int fd, i;
 700     VMDK4Header header;
 701     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
 702     char *desc_template =
 703         "# Disk DescriptorFile\n"
 704         "version=1\n"
 705         "CID=%x\n"
 706         "parentCID=ffffffff\n"
 707         "createType=\"monolithicSparse\"\n"
 708         "\n"
 709         "# Extent description\n"
 710         "RW %lu SPARSE \"%s\"\n"
 711         "\n"
 712         "# The Disk Data Base \n"
 713         "#DDB\n"
 714         "\n"
 715         "ddb.virtualHWVersion = \"%d\"\n"
 716         "ddb.geometry.cylinders = \"%lu\"\n"
 717         "ddb.geometry.heads = \"16\"\n"
 718         "ddb.geometry.sectors = \"63\"\n"
 719         "ddb.adapterType = \"ide\"\n";
 720     char desc[1024];
 721     const char *real_filename, *temp_str;
 722
 723     /* XXX: add support for backing file */
 724     if (backing_file) {
 725         return vmdk_snapshot_create(filename, backing_file);
 726     }
 727
 728     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 729               0644);
 730     if (fd < 0)
 731         return -1;
 732     magic = cpu_to_be32(VMDK4_MAGIC);
 733     memset(&header, 0, sizeof(header));
 734     header.version = cpu_to_le32(1);
 735     header.flags = cpu_to_le32(3); /* ?? */
 736     header.capacity = cpu_to_le64(total_size);
 737     header.granularity = cpu_to_le64(128);
 738     header.num_gtes_per_gte = cpu_to_le32(512);
 739
 740     grains = (total_size + header.granularity - 1) / header.granularity;
 741     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
 742     gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
 743     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
 744
 745     header.desc_offset = 1;
 746     header.desc_size = 20;
 747     header.rgd_offset = header.desc_offset + header.desc_size;
 748     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
 749     header.grain_offset =
 750        ((header.gd_offset + gd_size + (gt_size * gt_count) +
 751          header.granularity - 1) / header.granularity) *
 752         header.granularity;
 753
 754     header.desc_offset = cpu_to_le64(header.desc_offset);
 755     header.desc_size = cpu_to_le64(header.desc_size);
 756     header.rgd_offset = cpu_to_le64(header.rgd_offset);
 757     header.gd_offset = cpu_to_le64(header.gd_offset);
 758     header.grain_offset = cpu_to_le64(header.grain_offset);
 759
 760     header.check_bytes[0] = 0xa;
 761     header.check_bytes[1] = 0x20;
 762     header.check_bytes[2] = 0xd;
 763     header.check_bytes[3] = 0xa;
 764
 765     /* write all the data */
 766     write(fd, &magic, sizeof(magic));
 767     write(fd, &header, sizeof(header));
 768
 769     ftruncate(fd, header.grain_offset << 9);
 770
 771     /* write grain directory */
 772     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
 773     for (i = 0, tmp = header.rgd_offset + gd_size;
 774          i < gt_count; i++, tmp += gt_size)
 775         write(fd, &tmp, sizeof(tmp));
 776
 777     /* write backup grain directory */
 778     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
 779     for (i = 0, tmp = header.gd_offset + gd_size;
 780          i < gt_count; i++, tmp += gt_size)
 781         write(fd, &tmp, sizeof(tmp));
 782
 783     /* compose the descriptor */
 784     real_filename = filename;
 785     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 786         real_filename = temp_str + 1;
 787     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 788         real_filename = temp_str + 1;
 789     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 790         real_filename = temp_str + 1;
 791     sprintf(desc, desc_template, time(NULL), (unsigned long)total_size,
 792             real_filename, (flags & BLOCK_FLAG_COMPAT6 ? 6 : 4), total_size / (63 * 16));
 793
 794     /* write the descriptor */
 795     lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
 796     write(fd, desc, strlen(desc));
 797
 798     close(fd);
 799     return 0;
 800 }
 801
 802 static void vmdk_close(BlockDriverState *bs)
 803 {
 804     BDRVVmdkState *s = bs->opaque;
 805
 806     qemu_free(s->l1_table);
 807     qemu_free(s->l2_cache);
 808     bdrv_delete(s->hd);
 809     // try to close parent image, if exist
 810     vmdk_parent_close(s->hd);
 811 }
 812
 813 static void vmdk_flush(BlockDriverState *bs)
 814 {
 815     BDRVVmdkState *s = bs->opaque;
 816     bdrv_flush(s->hd);
 817 }
 818
 819 BlockDriver bdrv_vmdk = {
 820     "vmdk",
 821     sizeof(BDRVVmdkState),
 822     vmdk_probe,
 823     vmdk_open,
 824     vmdk_read,
 825     vmdk_write,
 826     vmdk_close,
 827     vmdk_create,
 828     vmdk_flush,
 829     vmdk_is_allocated,
 830 };