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         buf = NULL;
 111         ret = 0;
 112     } else {
 113 #ifdef DIOCGSECTORSIZE
 114         {
 115             unsigned int sectorsize = 512;
 116             if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
 117                 sectorsize > bufsize)
 118                 bufsize = sectorsize;
 119         }
 120 #endif
 121         buf = qemu_malloc(bufsize);
 122         if (!buf)
 123             return NULL;
 124         ret = read(fd, buf, bufsize);
 125         if (ret < 0) {
 126             close(fd);
 127             qemu_free(buf);
 128             return NULL;
 129         }
 130         close(fd);
 131     }
 132
 133     drv = NULL;
 134     score_max = 0;
 135     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 136         score = drv1->bdrv_probe(buf, ret, filename);
 137         if (score > score_max) {
 138             score_max = score;
 139             drv = drv1;
 140         }
 141     }
 142     qemu_free(buf);
 143     return drv;
 144 }
 145
 146 int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
 147 {
 148     return bdrv_open2(bs, filename, snapshot, NULL);
 149 }
 150
 151 int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
 152                BlockDriver *drv)
 153 {
 154     int ret;
 155     char tmp_filename[1024];
 156
 157     bs->read_only = 0;
 158     bs->is_temporary = 0;
 159     bs->encrypted = 0;
 160
 161     if (snapshot) {
 162         BlockDriverState *bs1;
 163         int64_t total_size;
 164
 165         /* if snapshot, we create a temporary backing file and open it
 166            instead of opening 'filename' directly */
 167
 168         /* if there is a backing file, use it */
 169         bs1 = bdrv_new("");
 170         if (!bs1) {
 171             return -1;
 172         }
 173         if (bdrv_open(bs1, filename, 0) < 0) {
 174             bdrv_delete(bs1);
 175             return -1;
 176         }
 177         total_size = bs1->total_sectors;
 178         bdrv_delete(bs1);
 179
 180         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 181         /* XXX: use cow for linux as it is more efficient ? */
 182         if (bdrv_create(&bdrv_qcow, tmp_filename,
 183                         total_size, filename, 0) < 0) {
 184             return -1;
 185         }
 186         filename = tmp_filename;
 187         bs->is_temporary = 1;
 188     }
 189
 190     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 191     if (!drv) {
 192         drv = find_image_format(filename);
 193         if (!drv)
 194             return -1;
 195     }
 196     bs->drv = drv;
 197     bs->opaque = qemu_mallocz(drv->instance_size);
 198     if (bs->opaque == NULL && drv->instance_size > 0)
 199         return -1;
 200
 201     ret = drv->bdrv_open(bs, filename);
 202     if (ret < 0) {
 203         qemu_free(bs->opaque);
 204         return -1;
 205     }
 206 #ifndef _WIN32
 207     if (bs->is_temporary) {
 208         unlink(filename);
 209     }
 210 #endif
 211     if (bs->backing_file[0] != '\0' && drv->bdrv_is_allocated) {
 212         /* if there is a backing file, use it */
 213         bs->backing_hd = bdrv_new("");
 214         if (!bs->backing_hd) {
 215         fail:
 216             bdrv_close(bs);
 217             return -1;
 218         }
 219         if (bdrv_open(bs->backing_hd, bs->backing_file, 0) < 0)
 220             goto fail;
 221     }
 222
 223     bs->inserted = 1;
 224
 225     /* call the change callback */
 226     if (bs->change_cb)
 227         bs->change_cb(bs->change_opaque);
 228
 229     return 0;
 230 }
 231
 232 void bdrv_close(BlockDriverState *bs)
 233 {
 234     if (bs->inserted) {
 235         if (bs->backing_hd)
 236             bdrv_delete(bs->backing_hd);
 237         bs->drv->bdrv_close(bs);
 238         qemu_free(bs->opaque);
 239 #ifdef _WIN32
 240         if (bs->is_temporary) {
 241             unlink(bs->filename);
 242         }
 243 #endif
 244         bs->opaque = NULL;
 245         bs->drv = NULL;
 246         bs->inserted = 0;
 247
 248         /* call the change callback */
 249         if (bs->change_cb)
 250             bs->change_cb(bs->change_opaque);
 251     }
 252 }
 253
 254 void bdrv_delete(BlockDriverState *bs)
 255 {
 256     /* XXX: remove the driver list */
 257     bdrv_close(bs);
 258     qemu_free(bs);
 259 }
 260
 261 /* commit COW file into the raw image */
 262 int bdrv_commit(BlockDriverState *bs)
 263 {
 264     int64_t i;
 265     int n, j;
 266     unsigned char sector[512];
 267
 268     if (!bs->inserted)
 269         return -ENOENT;
 270
 271     if (bs->read_only) {
 272         return -EACCES;
 273     }
 274
 275     if (!bs->backing_hd) {
 276         return -ENOTSUP;
 277     }
 278
 279     for (i = 0; i < bs->total_sectors;) {
 280         if (bs->drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 281             for(j = 0; j < n; j++) {
 282                 if (bdrv_read(bs, i, sector, 1) != 0) {
 283                     return -EIO;
 284                 }
 285
 286                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 287                     return -EIO;
 288                 }
 289                 i++;
 290             }
 291         } else {
 292             i += n;
 293         }
 294     }
 295     return 0;
 296 }
 297
 298 /* return -1 if error */
 299 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 300               uint8_t *buf, int nb_sectors)
 301 {
 302     int ret, n;
 303     BlockDriver *drv = bs->drv;
 304
 305     if (!bs->inserted)
 306         return -1;
 307
 308     while (nb_sectors > 0) {
 309         if (sector_num == 0 && bs->boot_sector_enabled) {
 310             memcpy(buf, bs->boot_sector_data, 512);
 311             n = 1;
 312         } else if (bs->backing_hd) {
 313             if (drv->bdrv_is_allocated(bs, sector_num, nb_sectors, &n)) {
 314                 ret = drv->bdrv_read(bs, sector_num, buf, n);
 315                 if (ret < 0)
 316                     return -1;
 317             } else {
 318                 /* read from the base image */
 319                 ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
 320                 if (ret < 0)
 321                     return -1;
 322             }
 323         } else {
 324             ret = drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 325             if (ret < 0)
 326                 return -1;
 327             /* no need to loop */
 328             break;
 329         }
 330         nb_sectors -= n;
 331         sector_num += n;
 332         buf += n * 512;
 333     }
 334     return 0;
 335 }
 336
 337 /* return -1 if error */
 338 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 339                const uint8_t *buf, int nb_sectors)
 340 {
 341     if (!bs->inserted)
 342         return -1;
 343     if (bs->read_only)
 344         return -1;
 345     return bs->drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 346 }
 347
 348 void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
 349 {
 350     *nb_sectors_ptr = bs->total_sectors;
 351 }
 352
 353 /* force a given boot sector. */
 354 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 355 {
 356     bs->boot_sector_enabled = 1;
 357     if (size > 512)
 358         size = 512;
 359     memcpy(bs->boot_sector_data, data, size);
 360     memset(bs->boot_sector_data + size, 0, 512 - size);
 361 }
 362
 363 void bdrv_set_geometry_hint(BlockDriverState *bs,
 364                             int cyls, int heads, int secs)
 365 {
 366     bs->cyls = cyls;
 367     bs->heads = heads;
 368     bs->secs = secs;
 369 }
 370
 371 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 372 {
 373     bs->type = type;
 374     bs->removable = ((type == BDRV_TYPE_CDROM ||
 375                       type == BDRV_TYPE_FLOPPY));
 376 }
 377
 378 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 379 {
 380     bs->translation = translation;
 381 }
 382
 383 void bdrv_get_geometry_hint(BlockDriverState *bs,
 384                             int *pcyls, int *pheads, int *psecs)
 385 {
 386     *pcyls = bs->cyls;
 387     *pheads = bs->heads;
 388     *psecs = bs->secs;
 389 }
 390
 391 int bdrv_get_type_hint(BlockDriverState *bs)
 392 {
 393     return bs->type;
 394 }
 395
 396 int bdrv_get_translation_hint(BlockDriverState *bs)
 397 {
 398     return bs->translation;
 399 }
 400
 401 int bdrv_is_removable(BlockDriverState *bs)
 402 {
 403     return bs->removable;
 404 }
 405
 406 int bdrv_is_read_only(BlockDriverState *bs)
 407 {
 408     return bs->read_only;
 409 }
 410
 411 int bdrv_is_inserted(BlockDriverState *bs)
 412 {
 413     return bs->inserted;
 414 }
 415
 416 int bdrv_is_locked(BlockDriverState *bs)
 417 {
 418     return bs->locked;
 419 }
 420
 421 void bdrv_set_locked(BlockDriverState *bs, int locked)
 422 {
 423     bs->locked = locked;
 424 }
 425
 426 void bdrv_set_change_cb(BlockDriverState *bs,
 427                         void (*change_cb)(void *opaque), void *opaque)
 428 {
 429     bs->change_cb = change_cb;
 430     bs->change_opaque = opaque;
 431 }
 432
 433 int bdrv_is_encrypted(BlockDriverState *bs)
 434 {
 435     if (bs->backing_hd && bs->backing_hd->encrypted)
 436         return 1;
 437     return bs->encrypted;
 438 }
 439
 440 int bdrv_set_key(BlockDriverState *bs, const char *key)
 441 {
 442     int ret;
 443     if (bs->backing_hd && bs->backing_hd->encrypted) {
 444         ret = bdrv_set_key(bs->backing_hd, key);
 445         if (ret < 0)
 446             return ret;
 447         if (!bs->encrypted)
 448             return 0;
 449     }
 450     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 451         return -1;
 452     return bs->drv->bdrv_set_key(bs, key);
 453 }
 454
 455 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 456 {
 457     if (!bs->inserted || !bs->drv) {
 458         buf[0] = '\0';
 459     } else {
 460         pstrcpy(buf, buf_size, bs->drv->format_name);
 461     }
 462 }
 463
 464 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 465                          void *opaque)
 466 {
 467     BlockDriver *drv;
 468
 469     for (drv = first_drv; drv != NULL; drv = drv->next) {
 470         it(opaque, drv->format_name);
 471     }
 472 }
 473
 474 BlockDriverState *bdrv_find(const char *name)
 475 {
 476     BlockDriverState *bs;
 477
 478     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 479         if (!strcmp(name, bs->device_name))
 480             return bs;
 481     }
 482     return NULL;
 483 }
 484
 485 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 486 {
 487     BlockDriverState *bs;
 488
 489     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 490         it(opaque, bs->device_name);
 491     }
 492 }
 493
 494 const char *bdrv_get_device_name(BlockDriverState *bs)
 495 {
 496     return bs->device_name;
 497 }
 498
 499 void bdrv_info(void)
 500 {
 501     BlockDriverState *bs;
 502
 503     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 504         term_printf("%s:", bs->device_name);
 505         term_printf(" type=");
 506         switch(bs->type) {
 507         case BDRV_TYPE_HD:
 508             term_printf("hd");
 509             break;
 510         case BDRV_TYPE_CDROM:
 511             term_printf("cdrom");
 512             break;
 513         case BDRV_TYPE_FLOPPY:
 514             term_printf("floppy");
 515             break;
 516         }
 517         term_printf(" removable=%d", bs->removable);
 518         if (bs->removable) {
 519             term_printf(" locked=%d", bs->locked);
 520         }
 521         if (bs->inserted) {
 522             term_printf(" file=%s", bs->filename);
 523             if (bs->backing_file[0] != '\0')
 524                 term_printf(" backing_file=%s", bs->backing_file);
 525             term_printf(" ro=%d", bs->read_only);
 526             term_printf(" drv=%s", bs->drv->format_name);
 527             if (bs->encrypted)
 528                 term_printf(" encrypted");
 529         } else {
 530             term_printf(" [not inserted]");
 531         }
 532         term_printf("\n");
 533     }
 534 }
 535
 536
 537 /**************************************************************/
 538 /* RAW block driver */
 539
 540 typedef struct BDRVRawState {
 541     int fd;
 542 } BDRVRawState;
 543
 544 static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
 545 {
 546     return 1; /* maybe */
 547 }
 548
 549 static int raw_open(BlockDriverState *bs, const char *filename)
 550 {
 551     BDRVRawState *s = bs->opaque;
 552     int fd;
 553     int64_t size;
 554 #ifdef _BSD
 555     struct stat sb;
 556 #endif
 557
 558     fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
 559     if (fd < 0) {
 560         fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
 561         if (fd < 0)
 562             return -1;
 563         bs->read_only = 1;
 564     }
 565 #ifdef _BSD
 566     if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
 567 #ifdef DIOCGMEDIASIZE
 568         if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
 569 #endif
 570             size = lseek(fd, 0LL, SEEK_END);
 571     } else
 572 #endif
 573     {
 574         size = lseek(fd, 0, SEEK_END);
 575     }
 576 #ifdef _WIN32
 577     /* On Windows hosts it can happen that we're unable to get file size
 578        for CD-ROM raw device (it's inherent limitation of the CDFS driver). */
 579     if (size == -1)
 580         size = LONG_LONG_MAX;
 581 #endif
 582     bs->total_sectors = size / 512;
 583     s->fd = fd;
 584     return 0;
 585 }
 586
 587 static int raw_read(BlockDriverState *bs, int64_t sector_num,
 588                     uint8_t *buf, int nb_sectors)
 589 {
 590     BDRVRawState *s = bs->opaque;
 591     int ret;
 592
 593     lseek(s->fd, sector_num * 512, SEEK_SET);
 594     ret = read(s->fd, buf, nb_sectors * 512);
 595     if (ret != nb_sectors * 512)
 596         return -1;
 597     return 0;
 598 }
 599
 600 static int raw_write(BlockDriverState *bs, int64_t sector_num,
 601                      const uint8_t *buf, int nb_sectors)
 602 {
 603     BDRVRawState *s = bs->opaque;
 604     int ret;
 605
 606     lseek(s->fd, sector_num * 512, SEEK_SET);
 607     ret = write(s->fd, buf, nb_sectors * 512);
 608     if (ret != nb_sectors * 512)
 609         return -1;
 610     return 0;
 611 }
 612
 613 static void raw_close(BlockDriverState *bs)
 614 {
 615     BDRVRawState *s = bs->opaque;
 616     close(s->fd);
 617 }
 618
 619 static int raw_create(const char *filename, int64_t total_size,
 620                       const char *backing_file, int flags)
 621 {
 622     int fd;
 623
 624     if (flags || backing_file)
 625         return -ENOTSUP;
 626
 627     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 628               0644);
 629     if (fd < 0)
 630         return -EIO;
 631     ftruncate(fd, total_size * 512);
 632     close(fd);
 633     return 0;
 634 }
 635
 636 BlockDriver bdrv_raw = {
 637     "raw",
 638     sizeof(BDRVRawState),
 639     raw_probe,
 640     raw_open,
 641     raw_read,
 642     raw_write,
 643     raw_close,
 644     raw_create,
 645 };
 646
 647 void bdrv_init(void)
 648 {
 649     bdrv_register(&bdrv_raw);
 650 #ifndef _WIN32
 651     bdrv_register(&bdrv_cow);
 652 #endif
 653     bdrv_register(&bdrv_qcow);
 654     bdrv_register(&bdrv_vmdk);
 655     bdrv_register(&bdrv_cloop);
 656     bdrv_register(&bdrv_dmg);
 657     bdrv_register(&bdrv_bochs);
 658     bdrv_register(&bdrv_vpc);
 659     bdrv_register(&bdrv_vvfat);
 660 }