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     DiskIOStatistics io;
  79 } BDRVVmdkState;
  80
  81 DiskIOStatistics vmdk_io_statistics(BlockDriverState *bs)
  82 {
  83     BDRVVmdkState *s = bs->opaque;
  84     // return disk I/O counters
  85     return s->io;
  86 }
  87
  88 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
  89 {
  90     uint32_t magic;
  91
  92     if (buf_size < 4)
  93         return 0;
  94     magic = be32_to_cpu(*(uint32_t *)buf);
  95     if (magic == VMDK3_MAGIC ||
  96         magic == VMDK4_MAGIC)
  97         return 100;
  98     else
  99         return 0;
 100 }
 101
 102 #define CHECK_CID 1
 103
 104 #define SECTOR_SIZE 512
 105 #define DESC_SIZE 20*SECTOR_SIZE        // 20 sectors of 512 bytes each
 106 #define HEADER_SIZE 512                         // first sector of 512 bytes
 107
 108 static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
 109 {
 110     BDRVVmdkState *s = bs->opaque;
 111     char desc[DESC_SIZE];
 112     uint32_t cid;
 113     char *p_name, *cid_str;
 114     size_t cid_str_size;
 115
 116     /* the descriptor offset = 0x200 */
 117     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 118         return 0;
 119
 120     if (parent) {
 121         cid_str = "parentCID";
 122         cid_str_size = sizeof("parentCID");
 123     } else {
 124         cid_str = "CID";
 125         cid_str_size = sizeof("CID");
 126     }
 127
 128     if ((p_name = strstr(desc,cid_str)) != 0) {
 129         p_name += cid_str_size;
 130         sscanf(p_name,"%x",&cid);
 131     }
 132
 133     return cid;
 134 }
 135
 136 static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
 137 {
 138     BDRVVmdkState *s = bs->opaque;
 139     char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
 140     char *p_name, *tmp_str;
 141
 142     /* the descriptor offset = 0x200 */
 143     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 144         return -1;
 145
 146     tmp_str = strstr(desc,"parentCID");
 147     strcpy(tmp_desc, tmp_str);
 148     if ((p_name = strstr(desc,"CID")) != 0) {
 149         p_name += sizeof("CID");
 150         sprintf(p_name,"%x\n",cid);
 151         strcat(desc,tmp_desc);
 152     }
 153
 154     if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 155         return -1;
 156     return 0;
 157 }
 158
 159 static int vmdk_is_cid_valid(BlockDriverState *bs)
 160 {
 161 #ifdef CHECK_CID
 162     BDRVVmdkState *s = bs->opaque;
 163     BlockDriverState *p_bs = s->hd->backing_hd;
 164     uint32_t cur_pcid;
 165
 166     if (p_bs) {
 167         cur_pcid = vmdk_read_cid(p_bs,0);
 168         if (s->parent_cid != cur_pcid)
 169             // CID not valid
 170             return 0;
 171     }
 172 #endif
 173     // CID valid
 174     return 1;
 175 }
 176
 177 static int vmdk_snapshot_create(const char *filename, const char *backing_file)
 178 {
 179     int snp_fd, p_fd;
 180     uint32_t p_cid;
 181     char *p_name, *gd_buf, *rgd_buf;
 182     const char *real_filename, *temp_str;
 183     VMDK4Header header;
 184     uint32_t gde_entries, gd_size;
 185     int64_t gd_offset, rgd_offset, capacity, gt_size;
 186     char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
 187     char *desc_template =
 188     "# Disk DescriptorFile\n"
 189     "version=1\n"
 190     "CID=%x\n"
 191     "parentCID=%x\n"
 192     "createType=\"monolithicSparse\"\n"
 193     "parentFileNameHint=\"%s\"\n"
 194     "\n"
 195     "# Extent description\n"
 196     "RW %lu SPARSE \"%s\"\n"
 197     "\n"
 198     "# The Disk Data Base \n"
 199     "#DDB\n"
 200     "\n";
 201
 202     snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
 203     if (snp_fd < 0)
 204         return -1;
 205     p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
 206     if (p_fd < 0) {
 207         close(snp_fd);
 208         return -1;
 209     }
 210
 211     /* read the header */
 212     if (lseek(p_fd, 0x0, SEEK_SET) == -1)
 213         goto fail;
 214     if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)
 215         goto fail;
 216
 217     /* write the header */
 218     if (lseek(snp_fd, 0x0, SEEK_SET) == -1)
 219         goto fail;
 220     if (write(snp_fd, hdr, HEADER_SIZE) == -1)
 221         goto fail;
 222
 223     memset(&header, 0, sizeof(header));
 224     memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
 225
 226     ftruncate(snp_fd, header.grain_offset << 9);
 227     /* the descriptor offset = 0x200 */
 228     if (lseek(p_fd, 0x200, SEEK_SET) == -1)
 229         goto fail;
 230     if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)
 231         goto fail;
 232
 233     if ((p_name = strstr(p_desc,"CID")) != 0) {
 234         p_name += sizeof("CID");
 235         sscanf(p_name,"%x",&p_cid);
 236     }
 237
 238     real_filename = filename;
 239     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 240         real_filename = temp_str + 1;
 241     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 242         real_filename = temp_str + 1;
 243     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 244         real_filename = temp_str + 1;
 245
 246     sprintf(s_desc, desc_template, p_cid, p_cid, backing_file
 247             , (uint32_t)header.capacity, real_filename);
 248
 249     /* write the descriptor */
 250     if (lseek(snp_fd, 0x200, SEEK_SET) == -1)
 251         goto fail;
 252     if (write(snp_fd, s_desc, strlen(s_desc)) == -1)
 253         goto fail;
 254
 255     gd_offset = header.gd_offset * SECTOR_SIZE;     // offset of GD table
 256     rgd_offset = header.rgd_offset * SECTOR_SIZE;   // offset of RGD table
 257     capacity = header.capacity * SECTOR_SIZE;       // Extent size
 258     /*
 259      * Each GDE span 32M disk, means:
 260      * 512 GTE per GT, each GTE points to grain
 261      */
 262     gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
 263     if (!gt_size)
 264         goto fail;
 265     gde_entries = (uint32_t)(capacity / gt_size);  // number of gde/rgde
 266     gd_size = gde_entries * sizeof(uint32_t);
 267
 268     /* write RGD */
 269     rgd_buf = qemu_malloc(gd_size);
 270     if (!rgd_buf)
 271         goto fail;
 272     if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)
 273         goto fail_rgd;
 274     if (read(p_fd, rgd_buf, gd_size) != gd_size)
 275         goto fail_rgd;
 276     if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)
 277         goto fail_rgd;
 278     if (write(snp_fd, rgd_buf, gd_size) == -1)
 279         goto fail_rgd;
 280     qemu_free(rgd_buf);
 281
 282     /* write GD */
 283     gd_buf = qemu_malloc(gd_size);
 284     if (!gd_buf)
 285         goto fail_rgd;
 286     if (lseek(p_fd, gd_offset, SEEK_SET) == -1)
 287         goto fail_gd;
 288     if (read(p_fd, gd_buf, gd_size) != gd_size)
 289         goto fail_gd;
 290     if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)
 291         goto fail_gd;
 292     if (write(snp_fd, gd_buf, gd_size) == -1)
 293         goto fail_gd;
 294     qemu_free(gd_buf);
 295
 296     close(p_fd);
 297     close(snp_fd);
 298     return 0;
 299
 300     fail_gd:
 301     qemu_free(gd_buf);
 302     fail_rgd:
 303     qemu_free(rgd_buf);
 304     fail:
 305     close(p_fd);
 306     close(snp_fd);
 307     return -1;
 308 }
 309
 310 static void vmdk_parent_close(BlockDriverState *bs)
 311 {
 312     if (bs->backing_hd)
 313         bdrv_close(bs->backing_hd);
 314 }
 315
 316
 317 static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
 318 {
 319     BDRVVmdkState *s = bs->opaque;
 320     char *p_name;
 321     char desc[DESC_SIZE];
 322     char parent_img_name[1024];
 323
 324     /* the descriptor offset = 0x200 */
 325     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 326         return -1;
 327
 328     if ((p_name = strstr(desc,"parentFileNameHint")) != 0) {
 329         char *end_name;
 330         struct stat file_buf;
 331
 332         p_name += sizeof("parentFileNameHint") + 1;
 333         if ((end_name = strchr(p_name,'\"')) == 0)
 334             return -1;
 335
 336         strncpy(s->hd->backing_file, p_name, end_name - p_name);
 337         if (stat(s->hd->backing_file, &file_buf) != 0) {
 338             path_combine(parent_img_name, sizeof(parent_img_name),
 339                          filename, s->hd->backing_file);
 340         } else {
 341             strcpy(parent_img_name, s->hd->backing_file);
 342         }
 343
 344         s->hd->backing_hd = bdrv_new("");
 345         if (!s->hd->backing_hd) {
 346             failure:
 347             bdrv_close(s->hd);
 348             return -1;
 349         }
 350         if (bdrv_open(s->hd->backing_hd, parent_img_name, 0) < 0)
 351             goto failure;
 352     }
 353
 354     return 0;
 355 }
 356
 357 static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
 358 {
 359     BDRVVmdkState *s = bs->opaque;
 360     uint32_t magic;
 361     int l1_size, i, ret;
 362
 363     ret = bdrv_file_open(&s->hd, filename, flags);
 364     if (ret < 0)
 365         return ret;
 366     if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
 367         goto fail;
 368
 369     magic = be32_to_cpu(magic);
 370     if (magic == VMDK3_MAGIC) {
 371         VMDK3Header header;
 372
 373         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 374             goto fail;
 375         s->cluster_sectors = le32_to_cpu(header.granularity);
 376         s->l2_size = 1 << 9;
 377         s->l1_size = 1 << 6;
 378         bs->total_sectors = le32_to_cpu(header.disk_sectors);
 379         s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
 380         s->l1_backup_table_offset = 0;
 381         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 382     } else if (magic == VMDK4_MAGIC) {
 383         VMDK4Header header;
 384
 385         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 386             goto fail;
 387         bs->total_sectors = le64_to_cpu(header.capacity);
 388         s->cluster_sectors = le64_to_cpu(header.granularity);
 389         s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
 390         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 391         if (s->l1_entry_sectors <= 0)
 392             goto fail;
 393         s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
 394             / s->l1_entry_sectors;
 395         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
 396         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
 397
 398         // try to open parent images, if exist
 399         if (vmdk_parent_open(bs, filename) != 0)
 400             goto fail;
 401         // write the CID once after the image creation
 402         s->parent_cid = vmdk_read_cid(bs,1);
 403     } else {
 404         goto fail;
 405     }
 406
 407     /* read the L1 table */
 408     l1_size = s->l1_size * sizeof(uint32_t);
 409     s->l1_table = qemu_malloc(l1_size);
 410     if (!s->l1_table)
 411         goto fail;
 412     if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
 413         goto fail;
 414     for(i = 0; i < s->l1_size; i++) {
 415         le32_to_cpus(&s->l1_table[i]);
 416     }
 417
 418     if (s->l1_backup_table_offset) {
 419         s->l1_backup_table = qemu_malloc(l1_size);
 420         if (!s->l1_backup_table)
 421             goto fail;
 422         if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
 423             goto fail;
 424         for(i = 0; i < s->l1_size; i++) {
 425             le32_to_cpus(&s->l1_backup_table[i]);
 426         }
 427     }
 428
 429     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
 430     if (!s->l2_cache)
 431         goto fail;
 432     return 0;
 433  fail:
 434     qemu_free(s->l1_backup_table);
 435     qemu_free(s->l1_table);
 436     qemu_free(s->l2_cache);
 437     bdrv_delete(s->hd);
 438     return -1;
 439 }
 440
 441 static uint64_t get_cluster_offset(BlockDriverState *bs, uint64_t offset, int allocate);
 442
 443 static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
 444                              uint64_t offset, int allocate)
 445 {
 446     uint64_t parent_cluster_offset;
 447     BDRVVmdkState *s = bs->opaque;
 448     uint8_t  whole_grain[s->cluster_sectors*512];        // 128 sectors * 512 bytes each = grain size 64KB
 449
 450     // we will be here if it's first write on non-exist grain(cluster).
 451     // try to read from parent image, if exist
 452     if (s->hd->backing_hd) {
 453         BDRVVmdkState *ps = s->hd->backing_hd->opaque;
 454
 455         if (!vmdk_is_cid_valid(bs))
 456             return -1;
 457         parent_cluster_offset = get_cluster_offset(s->hd->backing_hd, offset, allocate);
 458         if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) !=
 459                                                                             ps->cluster_sectors*512)
 460             return -1;
 461
 462         if (bdrv_pwrite(s->hd, cluster_offset << 9, whole_grain, sizeof(whole_grain)) !=
 463                                                                             sizeof(whole_grain))
 464             return -1;
 465     }
 466     return 0;
 467 }
 468
 469 static uint64_t get_cluster_offset(BlockDriverState *bs,
 470                                    uint64_t offset, int allocate)
 471 {
 472     BDRVVmdkState *s = bs->opaque;
 473     unsigned int l1_index, l2_offset, l2_index;
 474     int min_index, i, j;
 475     uint32_t min_count, *l2_table, tmp;
 476     uint64_t cluster_offset;
 477
 478     l1_index = (offset >> 9) / s->l1_entry_sectors;
 479     if (l1_index >= s->l1_size)
 480         return 0;
 481     l2_offset = s->l1_table[l1_index];
 482     if (!l2_offset)
 483         return 0;
 484     for(i = 0; i < L2_CACHE_SIZE; i++) {
 485         if (l2_offset == s->l2_cache_offsets[i]) {
 486             /* increment the hit count */
 487             if (++s->l2_cache_counts[i] == 0xffffffff) {
 488                 for(j = 0; j < L2_CACHE_SIZE; j++) {
 489                     s->l2_cache_counts[j] >>= 1;
 490                 }
 491             }
 492             l2_table = s->l2_cache + (i * s->l2_size);
 493             goto found;
 494         }
 495     }
 496     /* not found: load a new entry in the least used one */
 497     min_index = 0;
 498     min_count = 0xffffffff;
 499     for(i = 0; i < L2_CACHE_SIZE; i++) {
 500         if (s->l2_cache_counts[i] < min_count) {
 501             min_count = s->l2_cache_counts[i];
 502             min_index = i;
 503         }
 504     }
 505     l2_table = s->l2_cache + (min_index * s->l2_size);
 506     if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
 507                                                                         s->l2_size * sizeof(uint32_t))
 508         return 0;
 509
 510     s->l2_cache_offsets[min_index] = l2_offset;
 511     s->l2_cache_counts[min_index] = 1;
 512  found:
 513     l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
 514     cluster_offset = le32_to_cpu(l2_table[l2_index]);
 515     if (!cluster_offset) {
 516         struct stat file_buf;
 517
 518         if (!allocate)
 519             return 0;
 520         stat(s->hd->filename, &file_buf);
 521         cluster_offset = file_buf.st_size;
 522         bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
 523
 524         cluster_offset >>= 9;
 525         /* update L2 table */
 526         tmp = cpu_to_le32(cluster_offset);
 527         l2_table[l2_index] = tmp;
 528         if (bdrv_pwrite(s->hd, ((int64_t)l2_offset * 512) + (l2_index * sizeof(tmp)),
 529                         &tmp, sizeof(tmp)) != sizeof(tmp))
 530             return 0;
 531         /* update backup L2 table */
 532         if (s->l1_backup_table_offset != 0) {
 533             l2_offset = s->l1_backup_table[l1_index];
 534             if (bdrv_pwrite(s->hd, ((int64_t)l2_offset * 512) + (l2_index * sizeof(tmp)),
 535                             &tmp, sizeof(tmp)) != sizeof(tmp))
 536                 return 0;
 537         }
 538
 539         if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
 540             return 0;
 541     }
 542     cluster_offset <<= 9;
 543     return cluster_offset;
 544 }
 545
 546 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
 547                              int nb_sectors, int *pnum)
 548 {
 549     BDRVVmdkState *s = bs->opaque;
 550     int index_in_cluster, n;
 551     uint64_t cluster_offset;
 552
 553     cluster_offset = get_cluster_offset(bs, sector_num << 9, 0);
 554     index_in_cluster = sector_num % s->cluster_sectors;
 555     n = s->cluster_sectors - index_in_cluster;
 556     if (n > nb_sectors)
 557         n = nb_sectors;
 558     *pnum = n;
 559     return (cluster_offset != 0);
 560 }
 561
 562 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
 563                     uint8_t *buf, int nb_sectors)
 564 {
 565     BDRVVmdkState *s = bs->opaque;
 566     int index_in_cluster, n, ret;
 567     uint64_t cluster_offset;
 568
 569     while (nb_sectors > 0) {
 570         cluster_offset = get_cluster_offset(bs, sector_num << 9, 0);
 571         index_in_cluster = sector_num % s->cluster_sectors;
 572         n = s->cluster_sectors - index_in_cluster;
 573         if (n > nb_sectors)
 574             n = nb_sectors;
 575         if (!cluster_offset) {
 576             // try to read from parent image, if exist
 577             if (s->hd->backing_hd) {
 578                 if (!vmdk_is_cid_valid(bs))
 579                     return -1;
 580                 ret = bdrv_read(s->hd->backing_hd, sector_num, buf, n);
 581                 if (ret < 0)
 582                     return -1;
 583             } else {
 584                 memset(buf, 0, 512 * n);
 585             }
 586         } else {
 587             if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 588                 return -1;
 589         }
 590         nb_sectors -= n;
 591         sector_num += n;
 592         buf += n * 512;
 593         s->io.read_byte_counter += (uint64_t)(n*512);
 594     }
 595     return 0;
 596 }
 597
 598 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
 599                      const uint8_t *buf, int nb_sectors)
 600 {
 601     BDRVVmdkState *s = bs->opaque;
 602     int index_in_cluster, n;
 603     uint64_t cluster_offset;
 604     static int cid_update = 0;
 605
 606     while (nb_sectors > 0) {
 607         index_in_cluster = sector_num & (s->cluster_sectors - 1);
 608         n = s->cluster_sectors - index_in_cluster;
 609         if (n > nb_sectors)
 610             n = nb_sectors;
 611         cluster_offset = get_cluster_offset(bs, sector_num << 9, 1);
 612         if (!cluster_offset)
 613             return -1;
 614         if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 615             return -1;
 616         nb_sectors -= n;
 617         sector_num += n;
 618         buf += n * 512;
 619         s->io.write_byte_counter += (uint64_t)(n*512);
 620
 621         // update CID on the first write every time the virtual disk is opened
 622         if (!cid_update) {
 623             vmdk_write_cid(bs, time(NULL));
 624             cid_update++;
 625         }
 626     }
 627     return 0;
 628 }
 629
 630 static int vmdk_create(const char *filename, int64_t total_size,
 631                        const char *backing_file, int flags)
 632 {
 633     int fd, i;
 634     VMDK4Header header;
 635     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
 636     char *desc_template =
 637         "# Disk DescriptorFile\n"
 638         "version=1\n"
 639         "CID=%x\n"
 640         "parentCID=ffffffff\n"
 641         "createType=\"monolithicSparse\"\n"
 642         "\n"
 643         "# Extent description\n"
 644         "RW %lu SPARSE \"%s\"\n"
 645         "\n"
 646         "# The Disk Data Base \n"
 647         "#DDB\n"
 648         "\n"
 649         "ddb.virtualHWVersion = \"4\"\n"
 650         "ddb.geometry.cylinders = \"%lu\"\n"
 651         "ddb.geometry.heads = \"16\"\n"
 652         "ddb.geometry.sectors = \"63\"\n"
 653         "ddb.adapterType = \"ide\"\n";
 654     char desc[1024];
 655     const char *real_filename, *temp_str;
 656
 657     /* XXX: add support for backing file */
 658     if (backing_file) {
 659         return vmdk_snapshot_create(filename, backing_file);
 660     }
 661
 662     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 663               0644);
 664     if (fd < 0)
 665         return -1;
 666     magic = cpu_to_be32(VMDK4_MAGIC);
 667     memset(&header, 0, sizeof(header));
 668     header.version = cpu_to_le32(1);
 669     header.flags = cpu_to_le32(3); /* ?? */
 670     header.capacity = cpu_to_le64(total_size);
 671     header.granularity = cpu_to_le64(128);
 672     header.num_gtes_per_gte = cpu_to_le32(512);
 673
 674     grains = (total_size + header.granularity - 1) / header.granularity;
 675     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
 676     gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
 677     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
 678
 679     header.desc_offset = 1;
 680     header.desc_size = 20;
 681     header.rgd_offset = header.desc_offset + header.desc_size;
 682     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
 683     header.grain_offset =
 684        ((header.gd_offset + gd_size + (gt_size * gt_count) +
 685          header.granularity - 1) / header.granularity) *
 686         header.granularity;
 687
 688     header.desc_offset = cpu_to_le64(header.desc_offset);
 689     header.desc_size = cpu_to_le64(header.desc_size);
 690     header.rgd_offset = cpu_to_le64(header.rgd_offset);
 691     header.gd_offset = cpu_to_le64(header.gd_offset);
 692     header.grain_offset = cpu_to_le64(header.grain_offset);
 693
 694     header.check_bytes[0] = 0xa;
 695     header.check_bytes[1] = 0x20;
 696     header.check_bytes[2] = 0xd;
 697     header.check_bytes[3] = 0xa;
 698
 699     /* write all the data */
 700     write(fd, &magic, sizeof(magic));
 701     write(fd, &header, sizeof(header));
 702
 703     ftruncate(fd, header.grain_offset << 9);
 704
 705     /* write grain directory */
 706     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
 707     for (i = 0, tmp = header.rgd_offset + gd_size;
 708          i < gt_count; i++, tmp += gt_size)
 709         write(fd, &tmp, sizeof(tmp));
 710
 711     /* write backup grain directory */
 712     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
 713     for (i = 0, tmp = header.gd_offset + gd_size;
 714          i < gt_count; i++, tmp += gt_size)
 715         write(fd, &tmp, sizeof(tmp));
 716
 717     /* compose the descriptor */
 718     real_filename = filename;
 719     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 720         real_filename = temp_str + 1;
 721     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 722         real_filename = temp_str + 1;
 723     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 724         real_filename = temp_str + 1;
 725     sprintf(desc, desc_template, time(NULL), (unsigned long)total_size,
 726             real_filename, total_size / (63 * 16));
 727
 728     /* write the descriptor */
 729     lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
 730     write(fd, desc, strlen(desc));
 731
 732     close(fd);
 733     return 0;
 734 }
 735
 736 static void vmdk_close(BlockDriverState *bs)
 737 {
 738     BDRVVmdkState *s = bs->opaque;
 739
 740     qemu_free(s->l1_table);
 741     qemu_free(s->l2_cache);
 742     bdrv_delete(s->hd);
 743     // try to close parent image, if exist
 744     vmdk_parent_close(s->hd);
 745 }
 746
 747 static void vmdk_flush(BlockDriverState *bs)
 748 {
 749     BDRVVmdkState *s = bs->opaque;
 750     bdrv_flush(s->hd);
 751 }
 752
 753 BlockDriver bdrv_vmdk = {
 754     "vmdk",
 755     sizeof(BDRVVmdkState),
 756     vmdk_probe,
 757     vmdk_open,
 758     vmdk_read,
 759     vmdk_write,
 760     vmdk_close,
 761     vmdk_create,
 762     vmdk_flush,
 763     vmdk_is_allocated,
 764 };