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 "qemu-common.h"
  27 #include "block_int.h"
  28 #include "module.h"
  29
  30 #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
  31 #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
  32
  33 typedef struct {
  34     uint32_t version;
  35     uint32_t flags;
  36     uint32_t disk_sectors;
  37     uint32_t granularity;
  38     uint32_t l1dir_offset;
  39     uint32_t l1dir_size;
  40     uint32_t file_sectors;
  41     uint32_t cylinders;
  42     uint32_t heads;
  43     uint32_t sectors_per_track;
  44 } VMDK3Header;
  45
  46 typedef struct {
  47     uint32_t version;
  48     uint32_t flags;
  49     int64_t capacity;
  50     int64_t granularity;
  51     int64_t desc_offset;
  52     int64_t desc_size;
  53     int32_t num_gtes_per_gte;
  54     int64_t rgd_offset;
  55     int64_t gd_offset;
  56     int64_t grain_offset;
  57     char filler[1];
  58     char check_bytes[4];
  59 } __attribute__((packed)) VMDK4Header;
  60
  61 #define L2_CACHE_SIZE 16
  62
  63 typedef struct BDRVVmdkState {
  64     BlockDriverState *hd;
  65     int64_t l1_table_offset;
  66     int64_t l1_backup_table_offset;
  67     uint32_t *l1_table;
  68     uint32_t *l1_backup_table;
  69     unsigned int l1_size;
  70     uint32_t l1_entry_sectors;
  71
  72     unsigned int l2_size;
  73     uint32_t *l2_cache;
  74     uint32_t l2_cache_offsets[L2_CACHE_SIZE];
  75     uint32_t l2_cache_counts[L2_CACHE_SIZE];
  76
  77     unsigned int cluster_sectors;
  78     uint32_t parent_cid;
  79     int is_parent;
  80 } BDRVVmdkState;
  81
  82 typedef struct VmdkMetaData {
  83     uint32_t offset;
  84     unsigned int l1_index;
  85     unsigned int l2_index;
  86     unsigned int l2_offset;
  87     int valid;
  88 } VmdkMetaData;
  89
  90 typedef struct ActiveBDRVState{
  91     BlockDriverState *hd;            // active image handler
  92     uint64_t cluster_offset;         // current write offset
  93 }ActiveBDRVState;
  94
  95 static ActiveBDRVState activeBDRV;
  96
  97
  98 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
  99 {
 100     uint32_t magic;
 101
 102     if (buf_size < 4)
 103         return 0;
 104     magic = be32_to_cpu(*(uint32_t *)buf);
 105     if (magic == VMDK3_MAGIC ||
 106         magic == VMDK4_MAGIC)
 107         return 100;
 108     else
 109         return 0;
 110 }
 111
 112 #define CHECK_CID 1
 113
 114 #define SECTOR_SIZE 512
 115 #define DESC_SIZE 20*SECTOR_SIZE        // 20 sectors of 512 bytes each
 116 #define HEADER_SIZE 512                         // first sector of 512 bytes
 117
 118 static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
 119 {
 120     BDRVVmdkState *s = bs->opaque;
 121     char desc[DESC_SIZE];
 122     uint32_t cid;
 123     const char *p_name, *cid_str;
 124     size_t cid_str_size;
 125
 126     /* the descriptor offset = 0x200 */
 127     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 128         return 0;
 129
 130     if (parent) {
 131         cid_str = "parentCID";
 132         cid_str_size = sizeof("parentCID");
 133     } else {
 134         cid_str = "CID";
 135         cid_str_size = sizeof("CID");
 136     }
 137
 138     if ((p_name = strstr(desc,cid_str)) != NULL) {
 139         p_name += cid_str_size;
 140         sscanf(p_name,"%x",&cid);
 141     }
 142
 143     return cid;
 144 }
 145
 146 static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
 147 {
 148     BDRVVmdkState *s = bs->opaque;
 149     char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
 150     char *p_name, *tmp_str;
 151
 152     /* the descriptor offset = 0x200 */
 153     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 154         return -1;
 155
 156     tmp_str = strstr(desc,"parentCID");
 157     pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
 158     if ((p_name = strstr(desc,"CID")) != NULL) {
 159         p_name += sizeof("CID");
 160         snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);
 161         pstrcat(desc, sizeof(desc), tmp_desc);
 162     }
 163
 164     if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 165         return -1;
 166     return 0;
 167 }
 168
 169 static int vmdk_is_cid_valid(BlockDriverState *bs)
 170 {
 171 #ifdef CHECK_CID
 172     BDRVVmdkState *s = bs->opaque;
 173     BlockDriverState *p_bs = bs->backing_hd;
 174     uint32_t cur_pcid;
 175
 176     if (p_bs) {
 177         cur_pcid = vmdk_read_cid(p_bs,0);
 178         if (s->parent_cid != cur_pcid)
 179             // CID not valid
 180             return 0;
 181     }
 182 #endif
 183     // CID valid
 184     return 1;
 185 }
 186
 187 static int vmdk_snapshot_create(const char *filename, const char *backing_file)
 188 {
 189     int snp_fd, p_fd;
 190     int ret;
 191     uint32_t p_cid;
 192     char *p_name, *gd_buf, *rgd_buf;
 193     const char *real_filename, *temp_str;
 194     VMDK4Header header;
 195     uint32_t gde_entries, gd_size;
 196     int64_t gd_offset, rgd_offset, capacity, gt_size;
 197     char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
 198     static const char desc_template[] =
 199     "# Disk DescriptorFile\n"
 200     "version=1\n"
 201     "CID=%x\n"
 202     "parentCID=%x\n"
 203     "createType=\"monolithicSparse\"\n"
 204     "parentFileNameHint=\"%s\"\n"
 205     "\n"
 206     "# Extent description\n"
 207     "RW %u SPARSE \"%s\"\n"
 208     "\n"
 209     "# The Disk Data Base \n"
 210     "#DDB\n"
 211     "\n";
 212
 213     snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
 214     if (snp_fd < 0)
 215         return -errno;
 216     p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
 217     if (p_fd < 0) {
 218         close(snp_fd);
 219         return -errno;
 220     }
 221
 222     /* read the header */
 223     if (lseek(p_fd, 0x0, SEEK_SET) == -1) {
 224         ret = -errno;
 225         goto fail;
 226     }
 227     if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE) {
 228         ret = -errno;
 229         goto fail;
 230     }
 231
 232     /* write the header */
 233     if (lseek(snp_fd, 0x0, SEEK_SET) == -1) {
 234         ret = -errno;
 235         goto fail;
 236     }
 237     if (write(snp_fd, hdr, HEADER_SIZE) == -1) {
 238         ret = -errno;
 239         goto fail;
 240     }
 241
 242     memset(&header, 0, sizeof(header));
 243     memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
 244
 245     if (ftruncate(snp_fd, header.grain_offset << 9)) {
 246         ret = -errno;
 247         goto fail;
 248     }
 249     /* the descriptor offset = 0x200 */
 250     if (lseek(p_fd, 0x200, SEEK_SET) == -1) {
 251         ret = -errno;
 252         goto fail;
 253     }
 254     if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE) {
 255         ret = -errno;
 256         goto fail;
 257     }
 258
 259     if ((p_name = strstr(p_desc,"CID")) != NULL) {
 260         p_name += sizeof("CID");
 261         sscanf(p_name,"%x",&p_cid);
 262     }
 263
 264     real_filename = filename;
 265     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 266         real_filename = temp_str + 1;
 267     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 268         real_filename = temp_str + 1;
 269     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 270         real_filename = temp_str + 1;
 271
 272     snprintf(s_desc, sizeof(s_desc), desc_template, p_cid, p_cid, backing_file,
 273              (uint32_t)header.capacity, real_filename);
 274
 275     /* write the descriptor */
 276     if (lseek(snp_fd, 0x200, SEEK_SET) == -1) {
 277         ret = -errno;
 278         goto fail;
 279     }
 280     if (write(snp_fd, s_desc, strlen(s_desc)) == -1) {
 281         ret = -errno;
 282         goto fail;
 283     }
 284
 285     gd_offset = header.gd_offset * SECTOR_SIZE;     // offset of GD table
 286     rgd_offset = header.rgd_offset * SECTOR_SIZE;   // offset of RGD table
 287     capacity = header.capacity * SECTOR_SIZE;       // Extent size
 288     /*
 289      * Each GDE span 32M disk, means:
 290      * 512 GTE per GT, each GTE points to grain
 291      */
 292     gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
 293     if (!gt_size) {
 294         ret = -EINVAL;
 295         goto fail;
 296     }
 297     gde_entries = (uint32_t)(capacity / gt_size);  // number of gde/rgde
 298     gd_size = gde_entries * sizeof(uint32_t);
 299
 300     /* write RGD */
 301     rgd_buf = qemu_malloc(gd_size);
 302     if (lseek(p_fd, rgd_offset, SEEK_SET) == -1) {
 303         ret = -errno;
 304         goto fail_rgd;
 305     }
 306     if (read(p_fd, rgd_buf, gd_size) != gd_size) {
 307         ret = -errno;
 308         goto fail_rgd;
 309     }
 310     if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1) {
 311         ret = -errno;
 312         goto fail_rgd;
 313     }
 314     if (write(snp_fd, rgd_buf, gd_size) == -1) {
 315         ret = -errno;
 316         goto fail_rgd;
 317     }
 318
 319     /* write GD */
 320     gd_buf = qemu_malloc(gd_size);
 321     if (lseek(p_fd, gd_offset, SEEK_SET) == -1) {
 322         ret = -errno;
 323         goto fail_gd;
 324     }
 325     if (read(p_fd, gd_buf, gd_size) != gd_size) {
 326         ret = -errno;
 327         goto fail_gd;
 328     }
 329     if (lseek(snp_fd, gd_offset, SEEK_SET) == -1) {
 330         ret = -errno;
 331         goto fail_gd;
 332     }
 333     if (write(snp_fd, gd_buf, gd_size) == -1) {
 334         ret = -errno;
 335         goto fail_gd;
 336     }
 337     ret = 0;
 338
 339 fail_gd:
 340     qemu_free(gd_buf);
 341 fail_rgd:
 342     qemu_free(rgd_buf);
 343 fail:
 344     close(p_fd);
 345     close(snp_fd);
 346     return ret;
 347 }
 348
 349 static void vmdk_parent_close(BlockDriverState *bs)
 350 {
 351     if (bs->backing_hd)
 352         bdrv_close(bs->backing_hd);
 353 }
 354
 355 static int parent_open = 0;
 356 static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
 357 {
 358     BDRVVmdkState *s = bs->opaque;
 359     char *p_name;
 360     char desc[DESC_SIZE];
 361     char parent_img_name[1024];
 362
 363     /* the descriptor offset = 0x200 */
 364     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
 365         return -1;
 366
 367     if ((p_name = strstr(desc,"parentFileNameHint")) != NULL) {
 368         char *end_name;
 369         struct stat file_buf;
 370
 371         p_name += sizeof("parentFileNameHint") + 1;
 372         if ((end_name = strchr(p_name,'\"')) == NULL)
 373             return -1;
 374         if ((end_name - p_name) > sizeof (bs->backing_file) - 1)
 375             return -1;
 376
 377         pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
 378         if (stat(bs->backing_file, &file_buf) != 0) {
 379             path_combine(parent_img_name, sizeof(parent_img_name),
 380                          filename, bs->backing_file);
 381         } else {
 382             pstrcpy(parent_img_name, sizeof(parent_img_name),
 383                     bs->backing_file);
 384         }
 385
 386         bs->backing_hd = bdrv_new("");
 387         if (!bs->backing_hd) {
 388             failure:
 389             bdrv_close(s->hd);
 390             return -1;
 391         }
 392         parent_open = 1;
 393         if (bdrv_open(bs->backing_hd, parent_img_name, 0, NULL) < 0)
 394             goto failure;
 395         parent_open = 0;
 396     }
 397
 398     return 0;
 399 }
 400
 401 static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
 402 {
 403     BDRVVmdkState *s = bs->opaque;
 404     uint32_t magic;
 405     int l1_size, i, ret;
 406
 407     if (parent_open) {
 408         /* Parent must be opened as RO, no RDWR. */
 409         flags = 0;
 410     }
 411
 412     ret = bdrv_file_open(&s->hd, filename, flags);
 413     if (ret < 0)
 414         return ret;
 415     if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
 416         goto fail;
 417
 418     magic = be32_to_cpu(magic);
 419     if (magic == VMDK3_MAGIC) {
 420         VMDK3Header header;
 421
 422         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 423             goto fail;
 424         s->cluster_sectors = le32_to_cpu(header.granularity);
 425         s->l2_size = 1 << 9;
 426         s->l1_size = 1 << 6;
 427         bs->total_sectors = le32_to_cpu(header.disk_sectors);
 428         s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
 429         s->l1_backup_table_offset = 0;
 430         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 431     } else if (magic == VMDK4_MAGIC) {
 432         VMDK4Header header;
 433
 434         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
 435             goto fail;
 436         bs->total_sectors = le64_to_cpu(header.capacity);
 437         s->cluster_sectors = le64_to_cpu(header.granularity);
 438         s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
 439         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 440         if (s->l1_entry_sectors <= 0)
 441             goto fail;
 442         s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
 443             / s->l1_entry_sectors;
 444         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
 445         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
 446
 447         if (parent_open)
 448             s->is_parent = 1;
 449         else
 450             s->is_parent = 0;
 451
 452         // try to open parent images, if exist
 453         if (vmdk_parent_open(bs, filename) != 0)
 454             goto fail;
 455         // write the CID once after the image creation
 456         s->parent_cid = vmdk_read_cid(bs,1);
 457     } else {
 458         goto fail;
 459     }
 460
 461     /* read the L1 table */
 462     l1_size = s->l1_size * sizeof(uint32_t);
 463     s->l1_table = qemu_malloc(l1_size);
 464     if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
 465         goto fail;
 466     for(i = 0; i < s->l1_size; i++) {
 467         le32_to_cpus(&s->l1_table[i]);
 468     }
 469
 470     if (s->l1_backup_table_offset) {
 471         s->l1_backup_table = qemu_malloc(l1_size);
 472         if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
 473             goto fail;
 474         for(i = 0; i < s->l1_size; i++) {
 475             le32_to_cpus(&s->l1_backup_table[i]);
 476         }
 477     }
 478
 479     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
 480     return 0;
 481  fail:
 482     qemu_free(s->l1_backup_table);
 483     qemu_free(s->l1_table);
 484     qemu_free(s->l2_cache);
 485     bdrv_delete(s->hd);
 486     return -1;
 487 }
 488
 489 static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
 490                                    uint64_t offset, int allocate);
 491
 492 static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
 493                              uint64_t offset, int allocate)
 494 {
 495     uint64_t parent_cluster_offset;
 496     BDRVVmdkState *s = bs->opaque;
 497     uint8_t  whole_grain[s->cluster_sectors*512];        // 128 sectors * 512 bytes each = grain size 64KB
 498
 499     // we will be here if it's first write on non-exist grain(cluster).
 500     // try to read from parent image, if exist
 501     if (bs->backing_hd) {
 502         BDRVVmdkState *ps = bs->backing_hd->opaque;
 503
 504         if (!vmdk_is_cid_valid(bs))
 505             return -1;
 506
 507         parent_cluster_offset = get_cluster_offset(bs->backing_hd, NULL,
 508             offset, allocate);
 509
 510         if (parent_cluster_offset) {
 511             BDRVVmdkState *act_s = activeBDRV.hd->opaque;
 512
 513             if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)
 514                 return -1;
 515
 516             //Write grain only into the active image
 517             if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))
 518                 return -1;
 519         }
 520     }
 521     return 0;
 522 }
 523
 524 static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
 525 {
 526     BDRVVmdkState *s = bs->opaque;
 527
 528     /* update L2 table */
 529     if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
 530                     &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
 531         return -1;
 532     /* update backup L2 table */
 533     if (s->l1_backup_table_offset != 0) {
 534         m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
 535         if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
 536                         &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
 537             return -1;
 538     }
 539
 540     return 0;
 541 }
 542
 543 static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
 544                                    uint64_t offset, int allocate)
 545 {
 546     BDRVVmdkState *s = bs->opaque;
 547     unsigned int l1_index, l2_offset, l2_index;
 548     int min_index, i, j;
 549     uint32_t min_count, *l2_table, tmp = 0;
 550     uint64_t cluster_offset;
 551
 552     if (m_data)
 553         m_data->valid = 0;
 554
 555     l1_index = (offset >> 9) / s->l1_entry_sectors;
 556     if (l1_index >= s->l1_size)
 557         return 0;
 558     l2_offset = s->l1_table[l1_index];
 559     if (!l2_offset)
 560         return 0;
 561     for(i = 0; i < L2_CACHE_SIZE; i++) {
 562         if (l2_offset == s->l2_cache_offsets[i]) {
 563             /* increment the hit count */
 564             if (++s->l2_cache_counts[i] == 0xffffffff) {
 565                 for(j = 0; j < L2_CACHE_SIZE; j++) {
 566                     s->l2_cache_counts[j] >>= 1;
 567                 }
 568             }
 569             l2_table = s->l2_cache + (i * s->l2_size);
 570             goto found;
 571         }
 572     }
 573     /* not found: load a new entry in the least used one */
 574     min_index = 0;
 575     min_count = 0xffffffff;
 576     for(i = 0; i < L2_CACHE_SIZE; i++) {
 577         if (s->l2_cache_counts[i] < min_count) {
 578             min_count = s->l2_cache_counts[i];
 579             min_index = i;
 580         }
 581     }
 582     l2_table = s->l2_cache + (min_index * s->l2_size);
 583     if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
 584                                                                         s->l2_size * sizeof(uint32_t))
 585         return 0;
 586
 587     s->l2_cache_offsets[min_index] = l2_offset;
 588     s->l2_cache_counts[min_index] = 1;
 589  found:
 590     l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
 591     cluster_offset = le32_to_cpu(l2_table[l2_index]);
 592
 593     if (!cluster_offset) {
 594         if (!allocate)
 595             return 0;
 596         // Avoid the L2 tables update for the images that have snapshots.
 597         if (!s->is_parent) {
 598             cluster_offset = bdrv_getlength(s->hd);
 599             bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
 600
 601             cluster_offset >>= 9;
 602             tmp = cpu_to_le32(cluster_offset);
 603             l2_table[l2_index] = tmp;
 604             // Save the active image state
 605             activeBDRV.cluster_offset = cluster_offset;
 606             activeBDRV.hd = bs;
 607         }
 608         /* First of all we write grain itself, to avoid race condition
 609          * that may to corrupt the image.
 610          * This problem may occur because of insufficient space on host disk
 611          * or inappropriate VM shutdown.
 612          */
 613         if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
 614             return 0;
 615
 616         if (m_data) {
 617             m_data->offset = tmp;
 618             m_data->l1_index = l1_index;
 619             m_data->l2_index = l2_index;
 620             m_data->l2_offset = l2_offset;
 621             m_data->valid = 1;
 622         }
 623     }
 624     cluster_offset <<= 9;
 625     return cluster_offset;
 626 }
 627
 628 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
 629                              int nb_sectors, int *pnum)
 630 {
 631     BDRVVmdkState *s = bs->opaque;
 632     int index_in_cluster, n;
 633     uint64_t cluster_offset;
 634
 635     cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
 636     index_in_cluster = sector_num % s->cluster_sectors;
 637     n = s->cluster_sectors - index_in_cluster;
 638     if (n > nb_sectors)
 639         n = nb_sectors;
 640     *pnum = n;
 641     return (cluster_offset != 0);
 642 }
 643
 644 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
 645                     uint8_t *buf, int nb_sectors)
 646 {
 647     BDRVVmdkState *s = bs->opaque;
 648     int index_in_cluster, n, ret;
 649     uint64_t cluster_offset;
 650
 651     while (nb_sectors > 0) {
 652         cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
 653         index_in_cluster = sector_num % s->cluster_sectors;
 654         n = s->cluster_sectors - index_in_cluster;
 655         if (n > nb_sectors)
 656             n = nb_sectors;
 657         if (!cluster_offset) {
 658             // try to read from parent image, if exist
 659             if (bs->backing_hd) {
 660                 if (!vmdk_is_cid_valid(bs))
 661                     return -1;
 662                 ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
 663                 if (ret < 0)
 664                     return -1;
 665             } else {
 666                 memset(buf, 0, 512 * n);
 667             }
 668         } else {
 669             if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 670                 return -1;
 671         }
 672         nb_sectors -= n;
 673         sector_num += n;
 674         buf += n * 512;
 675     }
 676     return 0;
 677 }
 678
 679 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
 680                      const uint8_t *buf, int nb_sectors)
 681 {
 682     BDRVVmdkState *s = bs->opaque;
 683     VmdkMetaData m_data;
 684     int index_in_cluster, n;
 685     uint64_t cluster_offset;
 686     static int cid_update = 0;
 687
 688     if (sector_num > bs->total_sectors) {
 689         fprintf(stderr,
 690                 "(VMDK) Wrong offset: sector_num=0x%" PRIx64
 691                 " total_sectors=0x%" PRIx64 "\n",
 692                 sector_num, bs->total_sectors);
 693         return -1;
 694     }
 695
 696     while (nb_sectors > 0) {
 697         index_in_cluster = sector_num & (s->cluster_sectors - 1);
 698         n = s->cluster_sectors - index_in_cluster;
 699         if (n > nb_sectors)
 700             n = nb_sectors;
 701         cluster_offset = get_cluster_offset(bs, &m_data, sector_num << 9, 1);
 702         if (!cluster_offset)
 703             return -1;
 704
 705         if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
 706             return -1;
 707         if (m_data.valid) {
 708             /* update L2 tables */
 709             if (vmdk_L2update(bs, &m_data) == -1)
 710                 return -1;
 711         }
 712         nb_sectors -= n;
 713         sector_num += n;
 714         buf += n * 512;
 715
 716         // update CID on the first write every time the virtual disk is opened
 717         if (!cid_update) {
 718             vmdk_write_cid(bs, time(NULL));
 719             cid_update++;
 720         }
 721     }
 722     return 0;
 723 }
 724
 725 static int vmdk_create(const char *filename, QEMUOptionParameter *options)
 726 {
 727     int fd, i;
 728     VMDK4Header header;
 729     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
 730     static const char desc_template[] =
 731         "# Disk DescriptorFile\n"
 732         "version=1\n"
 733         "CID=%x\n"
 734         "parentCID=ffffffff\n"
 735         "createType=\"monolithicSparse\"\n"
 736         "\n"
 737         "# Extent description\n"
 738         "RW %" PRId64 " SPARSE \"%s\"\n"
 739         "\n"
 740         "# The Disk Data Base \n"
 741         "#DDB\n"
 742         "\n"
 743         "ddb.virtualHWVersion = \"%d\"\n"
 744         "ddb.geometry.cylinders = \"%" PRId64 "\"\n"
 745         "ddb.geometry.heads = \"16\"\n"
 746         "ddb.geometry.sectors = \"63\"\n"
 747         "ddb.adapterType = \"ide\"\n";
 748     char desc[1024];
 749     const char *real_filename, *temp_str;
 750     int64_t total_size = 0;
 751     const char *backing_file = NULL;
 752     int flags = 0;
 753     int ret;
 754
 755     // Read out options
 756     while (options && options->name) {
 757         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
 758             total_size = options->value.n / 512;
 759         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
 760             backing_file = options->value.s;
 761         } else if (!strcmp(options->name, BLOCK_OPT_COMPAT6)) {
 762             flags |= options->value.n ? BLOCK_FLAG_COMPAT6: 0;
 763         }
 764         options++;
 765     }
 766
 767     /* XXX: add support for backing file */
 768     if (backing_file) {
 769         return vmdk_snapshot_create(filename, backing_file);
 770     }
 771
 772     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 773               0644);
 774     if (fd < 0)
 775         return -errno;
 776     magic = cpu_to_be32(VMDK4_MAGIC);
 777     memset(&header, 0, sizeof(header));
 778     header.version = cpu_to_le32(1);
 779     header.flags = cpu_to_le32(3); /* ?? */
 780     header.capacity = cpu_to_le64(total_size);
 781     header.granularity = cpu_to_le64(128);
 782     header.num_gtes_per_gte = cpu_to_le32(512);
 783
 784     grains = (total_size + header.granularity - 1) / header.granularity;
 785     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
 786     gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
 787     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
 788
 789     header.desc_offset = 1;
 790     header.desc_size = 20;
 791     header.rgd_offset = header.desc_offset + header.desc_size;
 792     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
 793     header.grain_offset =
 794        ((header.gd_offset + gd_size + (gt_size * gt_count) +
 795          header.granularity - 1) / header.granularity) *
 796         header.granularity;
 797
 798     header.desc_offset = cpu_to_le64(header.desc_offset);
 799     header.desc_size = cpu_to_le64(header.desc_size);
 800     header.rgd_offset = cpu_to_le64(header.rgd_offset);
 801     header.gd_offset = cpu_to_le64(header.gd_offset);
 802     header.grain_offset = cpu_to_le64(header.grain_offset);
 803
 804     header.check_bytes[0] = 0xa;
 805     header.check_bytes[1] = 0x20;
 806     header.check_bytes[2] = 0xd;
 807     header.check_bytes[3] = 0xa;
 808
 809     /* write all the data */
 810     ret = qemu_write_full(fd, &magic, sizeof(magic));
 811     if (ret != sizeof(magic)) {
 812         ret = -errno;
 813         goto exit;
 814     }
 815     ret = qemu_write_full(fd, &header, sizeof(header));
 816     if (ret != sizeof(header)) {
 817         ret = -errno;
 818         goto exit;
 819     }
 820
 821     ret = ftruncate(fd, header.grain_offset << 9);
 822     if (ret < 0) {
 823         ret = -errno;
 824         goto exit;
 825     }
 826
 827     /* write grain directory */
 828     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
 829     for (i = 0, tmp = header.rgd_offset + gd_size;
 830          i < gt_count; i++, tmp += gt_size) {
 831         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
 832         if (ret != sizeof(tmp)) {
 833             ret = -errno;
 834             goto exit;
 835         }
 836     }
 837
 838     /* write backup grain directory */
 839     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
 840     for (i = 0, tmp = header.gd_offset + gd_size;
 841          i < gt_count; i++, tmp += gt_size) {
 842         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
 843         if (ret != sizeof(tmp)) {
 844             ret = -errno;
 845             goto exit;
 846         }
 847     }
 848
 849     /* compose the descriptor */
 850     real_filename = filename;
 851     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 852         real_filename = temp_str + 1;
 853     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 854         real_filename = temp_str + 1;
 855     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 856         real_filename = temp_str + 1;
 857     snprintf(desc, sizeof(desc), desc_template, (unsigned int)time(NULL),
 858              total_size, real_filename,
 859              (flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
 860              total_size / (int64_t)(63 * 16));
 861
 862     /* write the descriptor */
 863     lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
 864     ret = qemu_write_full(fd, desc, strlen(desc));
 865     if (ret != strlen(desc)) {
 866         ret = -errno;
 867         goto exit;
 868     }
 869
 870     ret = 0;
 871 exit:
 872     close(fd);
 873     return ret;
 874 }
 875
 876 static void vmdk_close(BlockDriverState *bs)
 877 {
 878     BDRVVmdkState *s = bs->opaque;
 879
 880     qemu_free(s->l1_table);
 881     qemu_free(s->l2_cache);
 882     // try to close parent image, if exist
 883     vmdk_parent_close(s->hd);
 884     bdrv_delete(s->hd);
 885 }
 886
 887 static void vmdk_flush(BlockDriverState *bs)
 888 {
 889     BDRVVmdkState *s = bs->opaque;
 890     bdrv_flush(s->hd);
 891 }
 892
 893
 894 static QEMUOptionParameter vmdk_create_options[] = {
 895     {
 896         .name = BLOCK_OPT_SIZE,
 897         .type = OPT_SIZE,
 898         .help = "Virtual disk size"
 899     },
 900     {
 901         .name = BLOCK_OPT_BACKING_FILE,
 902         .type = OPT_STRING,
 903         .help = "File name of a base image"
 904     },
 905     {
 906         .name = BLOCK_OPT_COMPAT6,
 907         .type = OPT_FLAG,
 908         .help = "VMDK version 6 image"
 909     },
 910     { NULL }
 911 };
 912
 913 static BlockDriver bdrv_vmdk = {
 914     .format_name        = "vmdk",
 915     .instance_size      = sizeof(BDRVVmdkState),
 916     .bdrv_probe         = vmdk_probe,
 917     .bdrv_open          = vmdk_open,
 918     .bdrv_read          = vmdk_read,
 919     .bdrv_write         = vmdk_write,
 920     .bdrv_close         = vmdk_close,
 921     .bdrv_create        = vmdk_create,
 922     .bdrv_flush         = vmdk_flush,
 923     .bdrv_is_allocated  = vmdk_is_allocated,
 924
 925     .create_options = vmdk_create_options,
 926 };
 927
 928 static void bdrv_vmdk_init(void)
 929 {
 930     bdrv_register(&bdrv_vmdk);
 931 }
 932
 933 block_init(bdrv_vmdk_init);