Annotation of qemu/block-vmdk.c, revision 1.1.1.6

1.1       root        1: /*
                      2:  * Block driver for the VMDK format
1.1.1.5   root        3:  *
1.1       root        4:  * Copyright (c) 2004 Fabrice Bellard
                      5:  * Copyright (c) 2005 Filip Navara
1.1.1.5   root        6:  *
1.1       root        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:  */
1.1.1.4   root       25: 
1.1.1.5   root       26: #include "qemu-common.h"
1.1       root       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 {
1.1.1.4   root       63:     BlockDriverState *hd;
1.1       root       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;
1.1.1.4   root       77:     uint32_t parent_cid;
1.1.1.5   root       78:     int is_parent;
1.1       root       79: } BDRVVmdkState;
                     80: 
1.1.1.5   root       81: typedef struct VmdkMetaData {
                     82:     uint32_t offset;
                     83:     unsigned int l1_index;
                     84:     unsigned int l2_index;
                     85:     unsigned int l2_offset;
                     86:     int valid;
                     87: } VmdkMetaData;
                     88: 
                     89: typedef struct ActiveBDRVState{
                     90:     BlockDriverState *hd;            // active image handler
                     91:     uint64_t cluster_offset;         // current write offset
                     92: }ActiveBDRVState;
                     93: 
                     94: static ActiveBDRVState activeBDRV;
                     95: 
                     96: 
1.1       root       97: static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
                     98: {
                     99:     uint32_t magic;
                    100: 
                    101:     if (buf_size < 4)
                    102:         return 0;
                    103:     magic = be32_to_cpu(*(uint32_t *)buf);
                    104:     if (magic == VMDK3_MAGIC ||
                    105:         magic == VMDK4_MAGIC)
                    106:         return 100;
                    107:     else
                    108:         return 0;
                    109: }
                    110: 
1.1.1.4   root      111: #define CHECK_CID 1
                    112: 
1.1.1.5   root      113: #define SECTOR_SIZE 512
1.1.1.4   root      114: #define DESC_SIZE 20*SECTOR_SIZE       // 20 sectors of 512 bytes each
1.1.1.5   root      115: #define HEADER_SIZE 512                        // first sector of 512 bytes
1.1.1.4   root      116: 
                    117: static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)
1.1       root      118: {
                    119:     BDRVVmdkState *s = bs->opaque;
1.1.1.4   root      120:     char desc[DESC_SIZE];
                    121:     uint32_t cid;
1.1.1.6 ! root      122:     const char *p_name, *cid_str;
1.1.1.4   root      123:     size_t cid_str_size;
                    124: 
                    125:     /* the descriptor offset = 0x200 */
                    126:     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
                    127:         return 0;
                    128: 
                    129:     if (parent) {
                    130:         cid_str = "parentCID";
                    131:         cid_str_size = sizeof("parentCID");
                    132:     } else {
                    133:         cid_str = "CID";
                    134:         cid_str_size = sizeof("CID");
                    135:     }
                    136: 
                    137:     if ((p_name = strstr(desc,cid_str)) != 0) {
                    138:         p_name += cid_str_size;
                    139:         sscanf(p_name,"%x",&cid);
                    140:     }
                    141: 
                    142:     return cid;
                    143: }
                    144: 
                    145: static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
                    146: {
                    147:     BDRVVmdkState *s = bs->opaque;
                    148:     char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
                    149:     char *p_name, *tmp_str;
                    150: 
                    151:     /* the descriptor offset = 0x200 */
                    152:     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
                    153:         return -1;
                    154: 
                    155:     tmp_str = strstr(desc,"parentCID");
1.1.1.6 ! root      156:     pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
1.1.1.4   root      157:     if ((p_name = strstr(desc,"CID")) != 0) {
                    158:         p_name += sizeof("CID");
1.1.1.6 ! root      159:         snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);
        !           160:         pstrcat(desc, sizeof(desc), tmp_desc);
1.1.1.4   root      161:     }
                    162: 
                    163:     if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
                    164:         return -1;
                    165:     return 0;
                    166: }
                    167: 
                    168: static int vmdk_is_cid_valid(BlockDriverState *bs)
                    169: {
                    170: #ifdef CHECK_CID
                    171:     BDRVVmdkState *s = bs->opaque;
                    172:     BlockDriverState *p_bs = s->hd->backing_hd;
                    173:     uint32_t cur_pcid;
                    174: 
                    175:     if (p_bs) {
                    176:         cur_pcid = vmdk_read_cid(p_bs,0);
                    177:         if (s->parent_cid != cur_pcid)
                    178:             // CID not valid
                    179:             return 0;
                    180:     }
                    181: #endif
                    182:     // CID valid
                    183:     return 1;
                    184: }
                    185: 
                    186: static int vmdk_snapshot_create(const char *filename, const char *backing_file)
                    187: {
                    188:     int snp_fd, p_fd;
                    189:     uint32_t p_cid;
1.1.1.5   root      190:     char *p_name, *gd_buf, *rgd_buf;
1.1.1.4   root      191:     const char *real_filename, *temp_str;
                    192:     VMDK4Header header;
                    193:     uint32_t gde_entries, gd_size;
                    194:     int64_t gd_offset, rgd_offset, capacity, gt_size;
                    195:     char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
1.1.1.6 ! root      196:     static const char desc_template[] =
1.1.1.4   root      197:     "# Disk DescriptorFile\n"
                    198:     "version=1\n"
                    199:     "CID=%x\n"
                    200:     "parentCID=%x\n"
                    201:     "createType=\"monolithicSparse\"\n"
                    202:     "parentFileNameHint=\"%s\"\n"
                    203:     "\n"
                    204:     "# Extent description\n"
1.1.1.6 ! root      205:     "RW %u SPARSE \"%s\"\n"
1.1.1.4   root      206:     "\n"
                    207:     "# The Disk Data Base \n"
                    208:     "#DDB\n"
                    209:     "\n";
                    210: 
                    211:     snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
                    212:     if (snp_fd < 0)
                    213:         return -1;
                    214:     p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
                    215:     if (p_fd < 0) {
                    216:         close(snp_fd);
                    217:         return -1;
                    218:     }
                    219: 
                    220:     /* read the header */
                    221:     if (lseek(p_fd, 0x0, SEEK_SET) == -1)
                    222:         goto fail;
                    223:     if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)
                    224:         goto fail;
                    225: 
                    226:     /* write the header */
                    227:     if (lseek(snp_fd, 0x0, SEEK_SET) == -1)
                    228:         goto fail;
                    229:     if (write(snp_fd, hdr, HEADER_SIZE) == -1)
                    230:         goto fail;
                    231: 
                    232:     memset(&header, 0, sizeof(header));
                    233:     memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
                    234: 
                    235:     ftruncate(snp_fd, header.grain_offset << 9);
                    236:     /* the descriptor offset = 0x200 */
                    237:     if (lseek(p_fd, 0x200, SEEK_SET) == -1)
                    238:         goto fail;
                    239:     if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)
                    240:         goto fail;
                    241: 
                    242:     if ((p_name = strstr(p_desc,"CID")) != 0) {
                    243:         p_name += sizeof("CID");
                    244:         sscanf(p_name,"%x",&p_cid);
                    245:     }
                    246: 
                    247:     real_filename = filename;
                    248:     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
                    249:         real_filename = temp_str + 1;
                    250:     if ((temp_str = strrchr(real_filename, '/')) != NULL)
                    251:         real_filename = temp_str + 1;
                    252:     if ((temp_str = strrchr(real_filename, ':')) != NULL)
                    253:         real_filename = temp_str + 1;
                    254: 
1.1.1.6 ! root      255:     snprintf(s_desc, sizeof(s_desc), desc_template, p_cid, p_cid, backing_file,
        !           256:              (uint32_t)header.capacity, real_filename);
1.1.1.4   root      257: 
                    258:     /* write the descriptor */
                    259:     if (lseek(snp_fd, 0x200, SEEK_SET) == -1)
                    260:         goto fail;
                    261:     if (write(snp_fd, s_desc, strlen(s_desc)) == -1)
                    262:         goto fail;
1.1       root      263: 
1.1.1.4   root      264:     gd_offset = header.gd_offset * SECTOR_SIZE;     // offset of GD table
                    265:     rgd_offset = header.rgd_offset * SECTOR_SIZE;   // offset of RGD table
                    266:     capacity = header.capacity * SECTOR_SIZE;       // Extent size
                    267:     /*
                    268:      * Each GDE span 32M disk, means:
                    269:      * 512 GTE per GT, each GTE points to grain
                    270:      */
                    271:     gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
                    272:     if (!gt_size)
                    273:         goto fail;
1.1.1.5   root      274:     gde_entries = (uint32_t)(capacity / gt_size);  // number of gde/rgde
1.1.1.4   root      275:     gd_size = gde_entries * sizeof(uint32_t);
                    276: 
                    277:     /* write RGD */
                    278:     rgd_buf = qemu_malloc(gd_size);
                    279:     if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)
                    280:         goto fail_rgd;
                    281:     if (read(p_fd, rgd_buf, gd_size) != gd_size)
                    282:         goto fail_rgd;
                    283:     if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)
                    284:         goto fail_rgd;
                    285:     if (write(snp_fd, rgd_buf, gd_size) == -1)
                    286:         goto fail_rgd;
                    287:     qemu_free(rgd_buf);
                    288: 
                    289:     /* write GD */
                    290:     gd_buf = qemu_malloc(gd_size);
                    291:     if (lseek(p_fd, gd_offset, SEEK_SET) == -1)
                    292:         goto fail_gd;
                    293:     if (read(p_fd, gd_buf, gd_size) != gd_size)
                    294:         goto fail_gd;
                    295:     if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)
                    296:         goto fail_gd;
                    297:     if (write(snp_fd, gd_buf, gd_size) == -1)
                    298:         goto fail_gd;
                    299:     qemu_free(gd_buf);
                    300: 
                    301:     close(p_fd);
                    302:     close(snp_fd);
                    303:     return 0;
                    304: 
                    305:     fail_gd:
                    306:     qemu_free(gd_buf);
1.1.1.5   root      307:     fail_rgd:
1.1.1.4   root      308:     qemu_free(rgd_buf);
                    309:     fail:
                    310:     close(p_fd);
                    311:     close(snp_fd);
                    312:     return -1;
                    313: }
                    314: 
                    315: static void vmdk_parent_close(BlockDriverState *bs)
                    316: {
                    317:     if (bs->backing_hd)
                    318:         bdrv_close(bs->backing_hd);
                    319: }
                    320: 
1.1.1.6 ! root      321: static int parent_open = 0;
1.1.1.4   root      322: static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
                    323: {
                    324:     BDRVVmdkState *s = bs->opaque;
1.1.1.5   root      325:     char *p_name;
1.1.1.4   root      326:     char desc[DESC_SIZE];
                    327:     char parent_img_name[1024];
                    328: 
                    329:     /* the descriptor offset = 0x200 */
                    330:     if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
                    331:         return -1;
                    332: 
                    333:     if ((p_name = strstr(desc,"parentFileNameHint")) != 0) {
                    334:         char *end_name;
                    335:         struct stat file_buf;
                    336: 
                    337:         p_name += sizeof("parentFileNameHint") + 1;
                    338:         if ((end_name = strchr(p_name,'\"')) == 0)
1.1       root      339:             return -1;
1.1.1.6 ! root      340:         if ((end_name - p_name) > sizeof (s->hd->backing_file) - 1)
        !           341:             return -1;
1.1.1.5   root      342: 
1.1.1.6 ! root      343:         pstrcpy(s->hd->backing_file, end_name - p_name + 1, p_name);
1.1.1.4   root      344:         if (stat(s->hd->backing_file, &file_buf) != 0) {
                    345:             path_combine(parent_img_name, sizeof(parent_img_name),
                    346:                          filename, s->hd->backing_file);
                    347:         } else {
1.1.1.6 ! root      348:             pstrcpy(parent_img_name, sizeof(parent_img_name),
        !           349:                     s->hd->backing_file);
1.1.1.4   root      350:         }
                    351: 
                    352:         s->hd->backing_hd = bdrv_new("");
                    353:         if (!s->hd->backing_hd) {
                    354:             failure:
                    355:             bdrv_close(s->hd);
                    356:             return -1;
                    357:         }
1.1.1.5   root      358:         parent_open = 1;
                    359:         if (bdrv_open(s->hd->backing_hd, parent_img_name, BDRV_O_RDONLY) < 0)
1.1.1.4   root      360:             goto failure;
1.1.1.5   root      361:         parent_open = 0;
1.1       root      362:     }
1.1.1.4   root      363: 
                    364:     return 0;
                    365: }
                    366: 
                    367: static int vmdk_open(BlockDriverState *bs, const char *filename, int flags)
                    368: {
                    369:     BDRVVmdkState *s = bs->opaque;
                    370:     uint32_t magic;
                    371:     int l1_size, i, ret;
                    372: 
1.1.1.5   root      373:     if (parent_open)
                    374:         // Parent must be opened as RO.
                    375:         flags = BDRV_O_RDONLY;
                    376: 
1.1.1.4   root      377:     ret = bdrv_file_open(&s->hd, filename, flags);
                    378:     if (ret < 0)
                    379:         return ret;
                    380:     if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
1.1       root      381:         goto fail;
1.1.1.4   root      382: 
1.1       root      383:     magic = be32_to_cpu(magic);
                    384:     if (magic == VMDK3_MAGIC) {
                    385:         VMDK3Header header;
1.1.1.4   root      386: 
                    387:         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
1.1       root      388:             goto fail;
                    389:         s->cluster_sectors = le32_to_cpu(header.granularity);
                    390:         s->l2_size = 1 << 9;
                    391:         s->l1_size = 1 << 6;
                    392:         bs->total_sectors = le32_to_cpu(header.disk_sectors);
                    393:         s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
                    394:         s->l1_backup_table_offset = 0;
                    395:         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
                    396:     } else if (magic == VMDK4_MAGIC) {
                    397:         VMDK4Header header;
1.1.1.4   root      398: 
                    399:         if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))
1.1       root      400:             goto fail;
1.1.1.2   root      401:         bs->total_sectors = le64_to_cpu(header.capacity);
                    402:         s->cluster_sectors = le64_to_cpu(header.granularity);
1.1       root      403:         s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
                    404:         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
                    405:         if (s->l1_entry_sectors <= 0)
                    406:             goto fail;
1.1.1.5   root      407:         s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
1.1       root      408:             / s->l1_entry_sectors;
                    409:         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
                    410:         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
1.1.1.4   root      411: 
1.1.1.5   root      412:         if (parent_open)
                    413:             s->is_parent = 1;
                    414:         else
                    415:             s->is_parent = 0;
                    416: 
1.1.1.4   root      417:         // try to open parent images, if exist
                    418:         if (vmdk_parent_open(bs, filename) != 0)
                    419:             goto fail;
                    420:         // write the CID once after the image creation
                    421:         s->parent_cid = vmdk_read_cid(bs,1);
1.1       root      422:     } else {
                    423:         goto fail;
                    424:     }
1.1.1.4   root      425: 
1.1       root      426:     /* read the L1 table */
                    427:     l1_size = s->l1_size * sizeof(uint32_t);
                    428:     s->l1_table = qemu_malloc(l1_size);
1.1.1.4   root      429:     if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)
1.1       root      430:         goto fail;
                    431:     for(i = 0; i < s->l1_size; i++) {
                    432:         le32_to_cpus(&s->l1_table[i]);
                    433:     }
                    434: 
                    435:     if (s->l1_backup_table_offset) {
                    436:         s->l1_backup_table = qemu_malloc(l1_size);
1.1.1.4   root      437:         if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)
1.1       root      438:             goto fail;
                    439:         for(i = 0; i < s->l1_size; i++) {
                    440:             le32_to_cpus(&s->l1_backup_table[i]);
                    441:         }
                    442:     }
                    443: 
                    444:     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
                    445:     return 0;
                    446:  fail:
                    447:     qemu_free(s->l1_backup_table);
                    448:     qemu_free(s->l1_table);
                    449:     qemu_free(s->l2_cache);
1.1.1.4   root      450:     bdrv_delete(s->hd);
1.1       root      451:     return -1;
                    452: }
                    453: 
1.1.1.5   root      454: static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
                    455:                                    uint64_t offset, int allocate);
1.1.1.4   root      456: 
                    457: static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,
                    458:                              uint64_t offset, int allocate)
                    459: {
                    460:     uint64_t parent_cluster_offset;
                    461:     BDRVVmdkState *s = bs->opaque;
                    462:     uint8_t  whole_grain[s->cluster_sectors*512];        // 128 sectors * 512 bytes each = grain size 64KB
                    463: 
                    464:     // we will be here if it's first write on non-exist grain(cluster).
                    465:     // try to read from parent image, if exist
                    466:     if (s->hd->backing_hd) {
                    467:         BDRVVmdkState *ps = s->hd->backing_hd->opaque;
                    468: 
                    469:         if (!vmdk_is_cid_valid(bs))
                    470:             return -1;
                    471: 
1.1.1.5   root      472:         parent_cluster_offset = get_cluster_offset(s->hd->backing_hd, NULL, offset, allocate);
                    473: 
                    474:         if (parent_cluster_offset) {
                    475:             BDRVVmdkState *act_s = activeBDRV.hd->opaque;
                    476: 
                    477:             if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)
                    478:                 return -1;
                    479: 
                    480:             //Write grain only into the active image
                    481:             if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))
                    482:                 return -1;
                    483:         }
                    484:     }
                    485:     return 0;
                    486: }
                    487: 
                    488: static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)
                    489: {
                    490:     BDRVVmdkState *s = bs->opaque;
                    491: 
                    492:     /* update L2 table */
                    493:     if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
                    494:                     &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
                    495:         return -1;
                    496:     /* update backup L2 table */
                    497:     if (s->l1_backup_table_offset != 0) {
                    498:         m_data->l2_offset = s->l1_backup_table[m_data->l1_index];
                    499:         if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),
                    500:                         &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))
1.1.1.4   root      501:             return -1;
                    502:     }
1.1.1.5   root      503: 
1.1.1.4   root      504:     return 0;
                    505: }
                    506: 
1.1.1.5   root      507: static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,
1.1       root      508:                                    uint64_t offset, int allocate)
                    509: {
                    510:     BDRVVmdkState *s = bs->opaque;
                    511:     unsigned int l1_index, l2_offset, l2_index;
                    512:     int min_index, i, j;
1.1.1.5   root      513:     uint32_t min_count, *l2_table, tmp = 0;
1.1       root      514:     uint64_t cluster_offset;
1.1.1.5   root      515: 
                    516:     if (m_data)
                    517:         m_data->valid = 0;
                    518: 
1.1       root      519:     l1_index = (offset >> 9) / s->l1_entry_sectors;
                    520:     if (l1_index >= s->l1_size)
                    521:         return 0;
                    522:     l2_offset = s->l1_table[l1_index];
                    523:     if (!l2_offset)
                    524:         return 0;
                    525:     for(i = 0; i < L2_CACHE_SIZE; i++) {
                    526:         if (l2_offset == s->l2_cache_offsets[i]) {
                    527:             /* increment the hit count */
                    528:             if (++s->l2_cache_counts[i] == 0xffffffff) {
                    529:                 for(j = 0; j < L2_CACHE_SIZE; j++) {
                    530:                     s->l2_cache_counts[j] >>= 1;
                    531:                 }
                    532:             }
                    533:             l2_table = s->l2_cache + (i * s->l2_size);
                    534:             goto found;
                    535:         }
                    536:     }
                    537:     /* not found: load a new entry in the least used one */
                    538:     min_index = 0;
                    539:     min_count = 0xffffffff;
                    540:     for(i = 0; i < L2_CACHE_SIZE; i++) {
                    541:         if (s->l2_cache_counts[i] < min_count) {
                    542:             min_count = s->l2_cache_counts[i];
                    543:             min_index = i;
                    544:         }
                    545:     }
                    546:     l2_table = s->l2_cache + (min_index * s->l2_size);
1.1.1.5   root      547:     if (bdrv_pread(s->hd, (int64_t)l2_offset * 512, l2_table, s->l2_size * sizeof(uint32_t)) !=
1.1.1.4   root      548:                                                                         s->l2_size * sizeof(uint32_t))
1.1       root      549:         return 0;
1.1.1.4   root      550: 
1.1       root      551:     s->l2_cache_offsets[min_index] = l2_offset;
                    552:     s->l2_cache_counts[min_index] = 1;
                    553:  found:
                    554:     l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
                    555:     cluster_offset = le32_to_cpu(l2_table[l2_index]);
1.1.1.4   root      556: 
1.1.1.5   root      557:     if (!cluster_offset) {
1.1       root      558:         if (!allocate)
                    559:             return 0;
1.1.1.5   root      560:         // Avoid the L2 tables update for the images that have snapshots.
                    561:         if (!s->is_parent) {
                    562:             cluster_offset = bdrv_getlength(s->hd);
                    563:             bdrv_truncate(s->hd, cluster_offset + (s->cluster_sectors << 9));
                    564: 
                    565:             cluster_offset >>= 9;
                    566:             tmp = cpu_to_le32(cluster_offset);
                    567:             l2_table[l2_index] = tmp;
                    568:             // Save the active image state
                    569:             activeBDRV.cluster_offset = cluster_offset;
                    570:             activeBDRV.hd = bs;
1.1       root      571:         }
1.1.1.5   root      572:         /* First of all we write grain itself, to avoid race condition
                    573:          * that may to corrupt the image.
                    574:          * This problem may occur because of insufficient space on host disk
                    575:          * or inappropriate VM shutdown.
                    576:          */
1.1.1.4   root      577:         if (get_whole_cluster(bs, cluster_offset, offset, allocate) == -1)
                    578:             return 0;
1.1.1.5   root      579: 
                    580:         if (m_data) {
                    581:             m_data->offset = tmp;
                    582:             m_data->l1_index = l1_index;
                    583:             m_data->l2_index = l2_index;
                    584:             m_data->l2_offset = l2_offset;
                    585:             m_data->valid = 1;
                    586:         }
1.1       root      587:     }
                    588:     cluster_offset <<= 9;
                    589:     return cluster_offset;
                    590: }
                    591: 
1.1.1.5   root      592: static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
1.1       root      593:                              int nb_sectors, int *pnum)
                    594: {
                    595:     BDRVVmdkState *s = bs->opaque;
                    596:     int index_in_cluster, n;
                    597:     uint64_t cluster_offset;
                    598: 
1.1.1.5   root      599:     cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
1.1       root      600:     index_in_cluster = sector_num % s->cluster_sectors;
                    601:     n = s->cluster_sectors - index_in_cluster;
                    602:     if (n > nb_sectors)
                    603:         n = nb_sectors;
                    604:     *pnum = n;
                    605:     return (cluster_offset != 0);
                    606: }
                    607: 
1.1.1.5   root      608: static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
1.1       root      609:                     uint8_t *buf, int nb_sectors)
                    610: {
                    611:     BDRVVmdkState *s = bs->opaque;
1.1.1.4   root      612:     int index_in_cluster, n, ret;
1.1       root      613:     uint64_t cluster_offset;
1.1.1.4   root      614: 
1.1       root      615:     while (nb_sectors > 0) {
1.1.1.5   root      616:         cluster_offset = get_cluster_offset(bs, NULL, sector_num << 9, 0);
1.1       root      617:         index_in_cluster = sector_num % s->cluster_sectors;
                    618:         n = s->cluster_sectors - index_in_cluster;
                    619:         if (n > nb_sectors)
                    620:             n = nb_sectors;
                    621:         if (!cluster_offset) {
1.1.1.4   root      622:             // try to read from parent image, if exist
                    623:             if (s->hd->backing_hd) {
                    624:                 if (!vmdk_is_cid_valid(bs))
                    625:                     return -1;
                    626:                 ret = bdrv_read(s->hd->backing_hd, sector_num, buf, n);
                    627:                 if (ret < 0)
                    628:                     return -1;
                    629:             } else {
                    630:                 memset(buf, 0, 512 * n);
                    631:             }
1.1       root      632:         } else {
1.1.1.4   root      633:             if(bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
1.1       root      634:                 return -1;
                    635:         }
                    636:         nb_sectors -= n;
                    637:         sector_num += n;
                    638:         buf += n * 512;
                    639:     }
                    640:     return 0;
                    641: }
                    642: 
1.1.1.5   root      643: static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
1.1       root      644:                      const uint8_t *buf, int nb_sectors)
                    645: {
                    646:     BDRVVmdkState *s = bs->opaque;
1.1.1.5   root      647:     VmdkMetaData m_data;
1.1.1.4   root      648:     int index_in_cluster, n;
1.1       root      649:     uint64_t cluster_offset;
1.1.1.4   root      650:     static int cid_update = 0;
1.1       root      651: 
1.1.1.5   root      652:     if (sector_num > bs->total_sectors) {
                    653:         fprintf(stderr,
                    654:                 "(VMDK) Wrong offset: sector_num=0x%" PRIx64
                    655:                 " total_sectors=0x%" PRIx64 "\n",
                    656:                 sector_num, bs->total_sectors);
                    657:         return -1;
                    658:     }
                    659: 
1.1       root      660:     while (nb_sectors > 0) {
                    661:         index_in_cluster = sector_num & (s->cluster_sectors - 1);
                    662:         n = s->cluster_sectors - index_in_cluster;
                    663:         if (n > nb_sectors)
                    664:             n = nb_sectors;
1.1.1.5   root      665:         cluster_offset = get_cluster_offset(bs, &m_data, sector_num << 9, 1);
1.1       root      666:         if (!cluster_offset)
                    667:             return -1;
1.1.1.5   root      668: 
1.1.1.4   root      669:         if (bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512) != n * 512)
1.1       root      670:             return -1;
1.1.1.5   root      671:         if (m_data.valid) {
                    672:             /* update L2 tables */
                    673:             if (vmdk_L2update(bs, &m_data) == -1)
                    674:                 return -1;
                    675:         }
1.1       root      676:         nb_sectors -= n;
                    677:         sector_num += n;
                    678:         buf += n * 512;
1.1.1.4   root      679: 
                    680:         // update CID on the first write every time the virtual disk is opened
                    681:         if (!cid_update) {
                    682:             vmdk_write_cid(bs, time(NULL));
                    683:             cid_update++;
                    684:         }
1.1       root      685:     }
                    686:     return 0;
                    687: }
                    688: 
                    689: static int vmdk_create(const char *filename, int64_t total_size,
                    690:                        const char *backing_file, int flags)
                    691: {
                    692:     int fd, i;
                    693:     VMDK4Header header;
                    694:     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
1.1.1.6 ! root      695:     static const char desc_template[] =
1.1       root      696:         "# Disk DescriptorFile\n"
                    697:         "version=1\n"
                    698:         "CID=%x\n"
                    699:         "parentCID=ffffffff\n"
                    700:         "createType=\"monolithicSparse\"\n"
                    701:         "\n"
                    702:         "# Extent description\n"
1.1.1.6 ! root      703:         "RW %" PRId64 " SPARSE \"%s\"\n"
1.1       root      704:         "\n"
                    705:         "# The Disk Data Base \n"
                    706:         "#DDB\n"
                    707:         "\n"
1.1.1.5   root      708:         "ddb.virtualHWVersion = \"%d\"\n"
1.1.1.6 ! root      709:         "ddb.geometry.cylinders = \"%" PRId64 "\"\n"
1.1       root      710:         "ddb.geometry.heads = \"16\"\n"
                    711:         "ddb.geometry.sectors = \"63\"\n"
                    712:         "ddb.adapterType = \"ide\"\n";
                    713:     char desc[1024];
                    714:     const char *real_filename, *temp_str;
                    715: 
                    716:     /* XXX: add support for backing file */
1.1.1.4   root      717:     if (backing_file) {
                    718:         return vmdk_snapshot_create(filename, backing_file);
                    719:     }
1.1       root      720: 
                    721:     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
                    722:               0644);
                    723:     if (fd < 0)
                    724:         return -1;
                    725:     magic = cpu_to_be32(VMDK4_MAGIC);
                    726:     memset(&header, 0, sizeof(header));
                    727:     header.version = cpu_to_le32(1);
                    728:     header.flags = cpu_to_le32(3); /* ?? */
                    729:     header.capacity = cpu_to_le64(total_size);
                    730:     header.granularity = cpu_to_le64(128);
                    731:     header.num_gtes_per_gte = cpu_to_le32(512);
                    732: 
                    733:     grains = (total_size + header.granularity - 1) / header.granularity;
                    734:     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
                    735:     gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
                    736:     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
                    737: 
                    738:     header.desc_offset = 1;
                    739:     header.desc_size = 20;
                    740:     header.rgd_offset = header.desc_offset + header.desc_size;
                    741:     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
                    742:     header.grain_offset =
                    743:        ((header.gd_offset + gd_size + (gt_size * gt_count) +
                    744:          header.granularity - 1) / header.granularity) *
                    745:         header.granularity;
                    746: 
                    747:     header.desc_offset = cpu_to_le64(header.desc_offset);
                    748:     header.desc_size = cpu_to_le64(header.desc_size);
                    749:     header.rgd_offset = cpu_to_le64(header.rgd_offset);
                    750:     header.gd_offset = cpu_to_le64(header.gd_offset);
                    751:     header.grain_offset = cpu_to_le64(header.grain_offset);
                    752: 
                    753:     header.check_bytes[0] = 0xa;
                    754:     header.check_bytes[1] = 0x20;
                    755:     header.check_bytes[2] = 0xd;
                    756:     header.check_bytes[3] = 0xa;
1.1.1.5   root      757: 
                    758:     /* write all the data */
1.1       root      759:     write(fd, &magic, sizeof(magic));
                    760:     write(fd, &header, sizeof(header));
                    761: 
                    762:     ftruncate(fd, header.grain_offset << 9);
                    763: 
                    764:     /* write grain directory */
                    765:     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
                    766:     for (i = 0, tmp = header.rgd_offset + gd_size;
                    767:          i < gt_count; i++, tmp += gt_size)
                    768:         write(fd, &tmp, sizeof(tmp));
1.1.1.5   root      769: 
1.1       root      770:     /* write backup grain directory */
                    771:     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
                    772:     for (i = 0, tmp = header.gd_offset + gd_size;
                    773:          i < gt_count; i++, tmp += gt_size)
                    774:         write(fd, &tmp, sizeof(tmp));
                    775: 
                    776:     /* compose the descriptor */
                    777:     real_filename = filename;
                    778:     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
                    779:         real_filename = temp_str + 1;
                    780:     if ((temp_str = strrchr(real_filename, '/')) != NULL)
                    781:         real_filename = temp_str + 1;
                    782:     if ((temp_str = strrchr(real_filename, ':')) != NULL)
                    783:         real_filename = temp_str + 1;
1.1.1.6 ! root      784:     snprintf(desc, sizeof(desc), desc_template, (unsigned int)time(NULL),
        !           785:              total_size, real_filename,
        !           786:              (flags & BLOCK_FLAG_COMPAT6 ? 6 : 4),
        !           787:              total_size / (int64_t)(63 * 16));
1.1       root      788: 
                    789:     /* write the descriptor */
                    790:     lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
                    791:     write(fd, desc, strlen(desc));
                    792: 
                    793:     close(fd);
                    794:     return 0;
                    795: }
                    796: 
                    797: static void vmdk_close(BlockDriverState *bs)
                    798: {
                    799:     BDRVVmdkState *s = bs->opaque;
1.1.1.4   root      800: 
1.1       root      801:     qemu_free(s->l1_table);
                    802:     qemu_free(s->l2_cache);
1.1.1.4   root      803:     // try to close parent image, if exist
                    804:     vmdk_parent_close(s->hd);
1.1.1.6 ! root      805:     bdrv_delete(s->hd);
1.1       root      806: }
                    807: 
1.1.1.3   root      808: static void vmdk_flush(BlockDriverState *bs)
                    809: {
                    810:     BDRVVmdkState *s = bs->opaque;
1.1.1.4   root      811:     bdrv_flush(s->hd);
1.1.1.3   root      812: }
                    813: 
1.1       root      814: BlockDriver bdrv_vmdk = {
                    815:     "vmdk",
                    816:     sizeof(BDRVVmdkState),
                    817:     vmdk_probe,
                    818:     vmdk_open,
                    819:     vmdk_read,
                    820:     vmdk_write,
                    821:     vmdk_close,
                    822:     vmdk_create,
1.1.1.3   root      823:     vmdk_flush,
1.1       root      824:     vmdk_is_allocated,
                    825: };

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