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