block.c

   1 /*
   2  * QEMU System Emulator block driver
   3  *
   4  * Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "vl.h"
  25 #include "block_int.h"
  26
  27 #ifdef _BSD
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <sys/ioctl.h>
  31 #include <sys/queue.h>
  32 #include <sys/disk.h>
  33 #endif
  34
  35 static BlockDriverState *bdrv_first;
  36 static BlockDriver *first_drv;
  37
  38 void bdrv_register(BlockDriver *bdrv)
  39 {
  40     bdrv->next = first_drv;
  41     first_drv = bdrv;
  42 }
  43
  44 /* create a new block device (by default it is empty) */
  45 BlockDriverState *bdrv_new(const char *device_name)
  46 {
  47     BlockDriverState **pbs, *bs;
  48
  49     bs = qemu_mallocz(sizeof(BlockDriverState));
  50     if(!bs)
  51         return NULL;
  52     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
  53     if (device_name[0] != '\0') {
  54         /* insert at the end */
  55         pbs = &bdrv_first;
  56         while (*pbs != NULL)
  57             pbs = &(*pbs)->next;
  58         *pbs = bs;
  59     }
  60     return bs;
  61 }
  62
  63 BlockDriver *bdrv_find_format(const char *format_name)
  64 {
  65     BlockDriver *drv1;
  66     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
  67         if (!strcmp(drv1->format_name, format_name))
  68             return drv1;
  69     }
  70     return NULL;
  71 }
  72
  73 int bdrv_create(BlockDriver *drv,
  74                 const char *filename, int64_t size_in_sectors,
  75                 const char *backing_file, int flags)
  76 {
  77     if (!drv->bdrv_create)
  78         return -ENOTSUP;
  79     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
  80 }
  81
  82 #ifdef _WIN32
  83 static void get_tmp_filename(char *filename, int size)
  84 {
  85     /* XXX: find a better function */
  86     tmpnam(filename);
  87 }
  88 #else
  89 static void get_tmp_filename(char *filename, int size)
  90 {
  91     int fd;
  92     /* XXX: race condition possible */
  93     pstrcpy(filename, size, "/tmp/vl.XXXXXX");
  94     fd = mkstemp(filename);
  95     close(fd);
  96 }
  97 #endif
  98
  99 /* XXX: force raw format if block or character device ? It would
 100    simplify the BSD case */
 101 static BlockDriver *find_image_format(const char *filename)
 102 {
 103     int fd, ret, score, score_max;
 104     BlockDriver *drv1, *drv;
 105     uint8_t *buf;
 106     size_t bufsize = 1024;
 107
 108     fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
 109     if (fd < 0)
 110         return NULL;
 111 #ifdef DIOCGSECTORSIZE
 112     {
 113         unsigned int sectorsize = 512;
 114         if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
 115             sectorsize > bufsize)
 116             bufsize = sectorsize;
 117     }
 118 #endif
 119     buf = malloc(bufsize);
 120     if (!buf)
 121         return NULL;
 122     ret = read(fd, buf, bufsize);
 123     if (ret < 0) {
 124         close(fd);
 125         free(buf);
 126         return NULL;
 127     }
 128     close(fd);
 129
 130     drv = NULL;
 131     score_max = 0;
 132     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 133         score = drv1->bdrv_probe(buf, ret, filename);
 134         if (score > score_max) {
 135             score_max = score;
 136             drv = drv1;
 137         }
 138     }
 139     free(buf);
 140     return drv;
 141 }
 142
 143 int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
 144 {
 145     return bdrv_open2(bs, filename, snapshot, NULL);
 146 }
 147
 148 int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
 149                BlockDriver *drv)
 150 {
 151     int ret;
 152     char tmp_filename[1024];
 153
 154     bs->read_only = 0;
 155     bs->is_temporary = 0;
 156     bs->encrypted = 0;
 157
 158     if (snapshot) {
 159         BlockDriverState *bs1;
 160         int64_t total_size;
 161
 162         /* if snapshot, we create a temporary backing file and open it
 163            instead of opening 'filename' directly */
 164
 165         /* if there is a backing file, use it */
 166         bs1 = bdrv_new("");
 167         if (!bs1) {
 168             return -1;
 169         }
 170         if (bdrv_open(bs1, filename, 0) < 0) {
 171             bdrv_delete(bs1);
 172             return -1;
 173         }
 174         total_size = bs1->total_sectors;
 175         bdrv_delete(bs1);
 176
 177         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 178         /* XXX: use cow for linux as it is more efficient ? */
 179         if (bdrv_create(&bdrv_qcow, tmp_filename,
 180                         total_size, filename, 0) < 0) {
 181             return -1;
 182         }
 183         filename = tmp_filename;
 184         bs->is_temporary = 1;
 185     }
 186
 187     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 188     if (!drv) {
 189         drv = find_image_format(filename);
 190         if (!drv)
 191             return -1;
 192     }
 193     bs->drv = drv;
 194     bs->opaque = qemu_mallocz(drv->instance_size);
 195     if (bs->opaque == NULL && drv->instance_size > 0)
 196         return -1;
 197
 198     ret = drv->bdrv_open(bs, filename);
 199     if (ret < 0) {
 200         qemu_free(bs->opaque);
 201         return -1;
 202     }
 203 #ifndef _WIN32
 204     if (bs->is_temporary) {
 205         unlink(filename);
 206     }
 207 #endif
 208     if (bs->backing_file[0] != '\0' && drv->bdrv_is_allocated) {
 209         /* if there is a backing file, use it */
 210         bs->backing_hd = bdrv_new("");
 211         if (!bs->backing_hd) {
 212         fail:
 213             bdrv_close(bs);
 214             return -1;
 215         }
 216         if (bdrv_open(bs->backing_hd, bs->backing_file, 0) < 0)
 217             goto fail;
 218     }
 219
 220     bs->inserted = 1;
 221
 222     /* call the change callback */
 223     if (bs->change_cb)
 224         bs->change_cb(bs->change_opaque);
 225
 226     return 0;
 227 }
 228
 229 void bdrv_close(BlockDriverState *bs)
 230 {
 231     if (bs->inserted) {
 232         if (bs->backing_hd)
 233             bdrv_delete(bs->backing_hd);
 234         bs->drv->bdrv_close(bs);
 235         qemu_free(bs->opaque);
 236 #ifdef _WIN32
 237         if (bs->is_temporary) {
 238             unlink(bs->filename);
 239         }
 240 #endif
 241         bs->opaque = NULL;
 242         bs->drv = NULL;
 243         bs->inserted = 0;
 244
 245         /* call the change callback */
 246         if (bs->change_cb)
 247             bs->change_cb(bs->change_opaque);
 248     }
 249 }
 250
 251 void bdrv_delete(BlockDriverState *bs)
 252 {
 253     /* XXX: remove the driver list */
 254     bdrv_close(bs);
 255     qemu_free(bs);
 256 }
 257
 258 /* commit COW file into the raw image */
 259 int bdrv_commit(BlockDriverState *bs)
 260 {
 261     int64_t i;
 262     int n, j;
 263     unsigned char sector[512];
 264
 265     if (!bs->inserted)
 266         return -ENOENT;
 267
 268     if (bs->read_only) {
 269         return -EACCES;
 270     }
 271
 272     if (!bs->backing_hd) {
 273         return -ENOTSUP;
 274     }
 275
 276     for (i = 0; i < bs->total_sectors;) {
 277         if (bs->drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 278             for(j = 0; j < n; j++) {
 279                 if (bdrv_read(bs, i, sector, 1) != 0) {
 280                     return -EIO;
 281                 }
 282
 283                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 284                     return -EIO;
 285                 }
 286                 i++;
 287             }
 288         } else {
 289             i += n;
 290         }
 291     }
 292     return 0;
 293 }
 294
 295 /* return -1 if error */
 296 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 297               uint8_t *buf, int nb_sectors)
 298 {
 299     int ret, n;
 300     BlockDriver *drv = bs->drv;
 301
 302     if (!bs->inserted)
 303         return -1;
 304
 305     while (nb_sectors > 0) {
 306         if (sector_num == 0 && bs->boot_sector_enabled) {
 307             memcpy(buf, bs->boot_sector_data, 512);
 308             n = 1;
 309         } else if (bs->backing_hd) {
 310             if (drv->bdrv_is_allocated(bs, sector_num, nb_sectors, &n)) {
 311                 ret = drv->bdrv_read(bs, sector_num, buf, n);
 312                 if (ret < 0)
 313                     return -1;
 314             } else {
 315                 /* read from the base image */
 316                 ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
 317                 if (ret < 0)
 318                     return -1;
 319             }
 320         } else {
 321             ret = drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 322             if (ret < 0)
 323                 return -1;
 324             /* no need to loop */
 325             break;
 326         }
 327         nb_sectors -= n;
 328         sector_num += n;
 329         buf += n * 512;
 330     }
 331     return 0;
 332 }
 333
 334 /* return -1 if error */
 335 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 336                const uint8_t *buf, int nb_sectors)
 337 {
 338     if (!bs->inserted)
 339         return -1;
 340     if (bs->read_only)
 341         return -1;
 342     return bs->drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 343 }
 344
 345 void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
 346 {
 347     *nb_sectors_ptr = bs->total_sectors;
 348 }
 349
 350 /* force a given boot sector. */
 351 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 352 {
 353     bs->boot_sector_enabled = 1;
 354     if (size > 512)
 355         size = 512;
 356     memcpy(bs->boot_sector_data, data, size);
 357     memset(bs->boot_sector_data + size, 0, 512 - size);
 358 }
 359
 360 void bdrv_set_geometry_hint(BlockDriverState *bs,
 361                             int cyls, int heads, int secs)
 362 {
 363     bs->cyls = cyls;
 364     bs->heads = heads;
 365     bs->secs = secs;
 366 }
 367
 368 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 369 {
 370     bs->type = type;
 371     bs->removable = ((type == BDRV_TYPE_CDROM ||
 372                       type == BDRV_TYPE_FLOPPY));
 373 }
 374
 375 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 376 {
 377     bs->translation = translation;
 378 }
 379
 380 void bdrv_get_geometry_hint(BlockDriverState *bs,
 381                             int *pcyls, int *pheads, int *psecs)
 382 {
 383     *pcyls = bs->cyls;
 384     *pheads = bs->heads;
 385     *psecs = bs->secs;
 386 }
 387
 388 int bdrv_get_type_hint(BlockDriverState *bs)
 389 {
 390     return bs->type;
 391 }
 392
 393 int bdrv_get_translation_hint(BlockDriverState *bs)
 394 {
 395     return bs->translation;
 396 }
 397
 398 int bdrv_is_removable(BlockDriverState *bs)
 399 {
 400     return bs->removable;
 401 }
 402
 403 int bdrv_is_read_only(BlockDriverState *bs)
 404 {
 405     return bs->read_only;
 406 }
 407
 408 int bdrv_is_inserted(BlockDriverState *bs)
 409 {
 410     return bs->inserted;
 411 }
 412
 413 int bdrv_is_locked(BlockDriverState *bs)
 414 {
 415     return bs->locked;
 416 }
 417
 418 void bdrv_set_locked(BlockDriverState *bs, int locked)
 419 {
 420     bs->locked = locked;
 421 }
 422
 423 void bdrv_set_change_cb(BlockDriverState *bs,
 424                         void (*change_cb)(void *opaque), void *opaque)
 425 {
 426     bs->change_cb = change_cb;
 427     bs->change_opaque = opaque;
 428 }
 429
 430 int bdrv_is_encrypted(BlockDriverState *bs)
 431 {
 432     if (bs->backing_hd && bs->backing_hd->encrypted)
 433         return 1;
 434     return bs->encrypted;
 435 }
 436
 437 int bdrv_set_key(BlockDriverState *bs, const char *key)
 438 {
 439     int ret;
 440     if (bs->backing_hd && bs->backing_hd->encrypted) {
 441         ret = bdrv_set_key(bs->backing_hd, key);
 442         if (ret < 0)
 443             return ret;
 444         if (!bs->encrypted)
 445             return 0;
 446     }
 447     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 448         return -1;
 449     return bs->drv->bdrv_set_key(bs, key);
 450 }
 451
 452 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 453 {
 454     if (!bs->inserted || !bs->drv) {
 455         buf[0] = '\0';
 456     } else {
 457         pstrcpy(buf, buf_size, bs->drv->format_name);
 458     }
 459 }
 460
 461 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 462                          void *opaque)
 463 {
 464     BlockDriver *drv;
 465
 466     for (drv = first_drv; drv != NULL; drv = drv->next) {
 467         it(opaque, drv->format_name);
 468     }
 469 }
 470
 471 BlockDriverState *bdrv_find(const char *name)
 472 {
 473     BlockDriverState *bs;
 474
 475     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 476         if (!strcmp(name, bs->device_name))
 477             return bs;
 478     }
 479     return NULL;
 480 }
 481
 482 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 483 {
 484     BlockDriverState *bs;
 485
 486     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 487         it(opaque, bs->device_name);
 488     }
 489 }
 490
 491 const char *bdrv_get_device_name(BlockDriverState *bs)
 492 {
 493     return bs->device_name;
 494 }
 495
 496 void bdrv_info(void)
 497 {
 498     BlockDriverState *bs;
 499
 500     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 501         term_printf("%s:", bs->device_name);
 502         term_printf(" type=");
 503         switch(bs->type) {
 504         case BDRV_TYPE_HD:
 505             term_printf("hd");
 506             break;
 507         case BDRV_TYPE_CDROM:
 508             term_printf("cdrom");
 509             break;
 510         case BDRV_TYPE_FLOPPY:
 511             term_printf("floppy");
 512             break;
 513         }
 514         term_printf(" removable=%d", bs->removable);
 515         if (bs->removable) {
 516             term_printf(" locked=%d", bs->locked);
 517         }
 518         if (bs->inserted) {
 519             term_printf(" file=%s", bs->filename);
 520             if (bs->backing_file[0] != '\0')
 521                 term_printf(" backing_file=%s", bs->backing_file);
 522             term_printf(" ro=%d", bs->read_only);
 523             term_printf(" drv=%s", bs->drv->format_name);
 524             if (bs->encrypted)
 525                 term_printf(" encrypted");
 526         } else {
 527             term_printf(" [not inserted]");
 528         }
 529         term_printf("\n");
 530     }
 531 }
 532
 533
 534 /**************************************************************/
 535 /* RAW block driver */
 536
 537 typedef struct BDRVRawState {
 538     int fd;
 539 } BDRVRawState;
 540
 541 static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
 542 {
 543     return 1; /* maybe */
 544 }
 545
 546 static int raw_open(BlockDriverState *bs, const char *filename)
 547 {
 548     BDRVRawState *s = bs->opaque;
 549     int fd;
 550     int64_t size;
 551 #ifdef _BSD
 552     struct stat sb;
 553 #endif
 554
 555     fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
 556     if (fd < 0) {
 557         fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
 558         if (fd < 0)
 559             return -1;
 560         bs->read_only = 1;
 561     }
 562 #ifdef _BSD
 563     if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
 564 #ifdef DIOCGMEDIASIZE
 565         if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
 566 #endif
 567             size = lseek(fd, 0LL, SEEK_END);
 568     } else
 569 #endif
 570     {
 571         size = lseek(fd, 0, SEEK_END);
 572     }
 573 #ifdef _WIN32
 574     /* On Windows hosts it can happen that we're unable to get file size
 575        for CD-ROM raw device (it's inherent limitation of the CDFS driver). */
 576     if (size == -1)
 577         size = LONG_LONG_MAX;
 578 #endif
 579     bs->total_sectors = size / 512;
 580     s->fd = fd;
 581     return 0;
 582 }
 583
 584 static int raw_read(BlockDriverState *bs, int64_t sector_num,
 585                     uint8_t *buf, int nb_sectors)
 586 {
 587     BDRVRawState *s = bs->opaque;
 588     int ret;
 589
 590     lseek(s->fd, sector_num * 512, SEEK_SET);
 591     ret = read(s->fd, buf, nb_sectors * 512);
 592     if (ret != nb_sectors * 512)
 593         return -1;
 594     return 0;
 595 }
 596
 597 static int raw_write(BlockDriverState *bs, int64_t sector_num,
 598                      const uint8_t *buf, int nb_sectors)
 599 {
 600     BDRVRawState *s = bs->opaque;
 601     int ret;
 602
 603     lseek(s->fd, sector_num * 512, SEEK_SET);
 604     ret = write(s->fd, buf, nb_sectors * 512);
 605     if (ret != nb_sectors * 512)
 606         return -1;
 607     return 0;
 608 }
 609
 610 static void raw_close(BlockDriverState *bs)
 611 {
 612     BDRVRawState *s = bs->opaque;
 613     close(s->fd);
 614 }
 615
 616 static int raw_create(const char *filename, int64_t total_size,
 617                       const char *backing_file, int flags)
 618 {
 619     int fd;
 620
 621     if (flags || backing_file)
 622         return -ENOTSUP;
 623
 624     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 625               0644);
 626     if (fd < 0)
 627         return -EIO;
 628     ftruncate(fd, total_size * 512);
 629     close(fd);
 630     return 0;
 631 }
 632
 633 BlockDriver bdrv_raw = {
 634     "raw",
 635     sizeof(BDRVRawState),
 636     raw_probe,
 637     raw_open,
 638     raw_read,
 639     raw_write,
 640     raw_close,
 641     raw_create,
 642 };
 643
 644 void bdrv_init(void)
 645 {
 646     bdrv_register(&bdrv_raw);
 647 #ifndef _WIN32
 648     bdrv_register(&bdrv_cow);
 649 #endif
 650     bdrv_register(&bdrv_qcow);
 651     bdrv_register(&bdrv_vmdk);
 652     bdrv_register(&bdrv_cloop);
 653     bdrv_register(&bdrv_dmg);
 654     bdrv_register(&bdrv_bochs);
 655     bdrv_register(&bdrv_vpc);
 656 }