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 "qemu-common.h"
  25 #include "console.h"
  26 #include "block_int.h"
  27
  28 #ifdef _BSD
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <sys/ioctl.h>
  32 #include <sys/queue.h>
  33 #include <sys/disk.h>
  34 #endif
  35
  36 #define SECTOR_BITS 9
  37 #define SECTOR_SIZE (1 << SECTOR_BITS)
  38
  39 typedef struct BlockDriverAIOCBSync {
  40     BlockDriverAIOCB common;
  41     QEMUBH *bh;
  42     int ret;
  43 } BlockDriverAIOCBSync;
  44
  45 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
  46         int64_t sector_num, uint8_t *buf, int nb_sectors,
  47         BlockDriverCompletionFunc *cb, void *opaque);
  48 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
  49         int64_t sector_num, const uint8_t *buf, int nb_sectors,
  50         BlockDriverCompletionFunc *cb, void *opaque);
  51 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
  52 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
  53                         uint8_t *buf, int nb_sectors);
  54 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
  55                          const uint8_t *buf, int nb_sectors);
  56
  57 BlockDriverState *bdrv_first;
  58
  59 static BlockDriver *first_drv;
  60
  61 int path_is_absolute(const char *path)
  62 {
  63     const char *p;
  64 #ifdef _WIN32
  65     /* specific case for names like: "\\.\d:" */
  66     if (*path == '/' || *path == '\\')
  67         return 1;
  68 #endif
  69     p = strchr(path, ':');
  70     if (p)
  71         p++;
  72     else
  73         p = path;
  74 #ifdef _WIN32
  75     return (*p == '/' || *p == '\\');
  76 #else
  77     return (*p == '/');
  78 #endif
  79 }
  80
  81 /* if filename is absolute, just copy it to dest. Otherwise, build a
  82    path to it by considering it is relative to base_path. URL are
  83    supported. */
  84 void path_combine(char *dest, int dest_size,
  85                   const char *base_path,
  86                   const char *filename)
  87 {
  88     const char *p, *p1;
  89     int len;
  90
  91     if (dest_size <= 0)
  92         return;
  93     if (path_is_absolute(filename)) {
  94         pstrcpy(dest, dest_size, filename);
  95     } else {
  96         p = strchr(base_path, ':');
  97         if (p)
  98             p++;
  99         else
 100             p = base_path;
 101         p1 = strrchr(base_path, '/');
 102 #ifdef _WIN32
 103         {
 104             const char *p2;
 105             p2 = strrchr(base_path, '\\');
 106             if (!p1 || p2 > p1)
 107                 p1 = p2;
 108         }
 109 #endif
 110         if (p1)
 111             p1++;
 112         else
 113             p1 = base_path;
 114         if (p1 > p)
 115             p = p1;
 116         len = p - base_path;
 117         if (len > dest_size - 1)
 118             len = dest_size - 1;
 119         memcpy(dest, base_path, len);
 120         dest[len] = '\0';
 121         pstrcat(dest, dest_size, filename);
 122     }
 123 }
 124
 125
 126 static void bdrv_register(BlockDriver *bdrv)
 127 {
 128     if (!bdrv->bdrv_aio_read) {
 129         /* add AIO emulation layer */
 130         bdrv->bdrv_aio_read = bdrv_aio_read_em;
 131         bdrv->bdrv_aio_write = bdrv_aio_write_em;
 132         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
 133         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
 134     } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
 135         /* add synchronous IO emulation layer */
 136         bdrv->bdrv_read = bdrv_read_em;
 137         bdrv->bdrv_write = bdrv_write_em;
 138     }
 139     bdrv->next = first_drv;
 140     first_drv = bdrv;
 141 }
 142
 143 /* create a new block device (by default it is empty) */
 144 BlockDriverState *bdrv_new(const char *device_name)
 145 {
 146     BlockDriverState **pbs, *bs;
 147
 148     bs = qemu_mallocz(sizeof(BlockDriverState));
 149     if(!bs)
 150         return NULL;
 151     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
 152     if (device_name[0] != '\0') {
 153         /* insert at the end */
 154         pbs = &bdrv_first;
 155         while (*pbs != NULL)
 156             pbs = &(*pbs)->next;
 157         *pbs = bs;
 158     }
 159     return bs;
 160 }
 161
 162 BlockDriver *bdrv_find_format(const char *format_name)
 163 {
 164     BlockDriver *drv1;
 165     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 166         if (!strcmp(drv1->format_name, format_name))
 167             return drv1;
 168     }
 169     return NULL;
 170 }
 171
 172 int bdrv_create(BlockDriver *drv,
 173                 const char *filename, int64_t size_in_sectors,
 174                 const char *backing_file, int flags)
 175 {
 176     if (!drv->bdrv_create)
 177         return -ENOTSUP;
 178     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
 179 }
 180
 181 #ifdef _WIN32
 182 void get_tmp_filename(char *filename, int size)
 183 {
 184     char temp_dir[MAX_PATH];
 185
 186     GetTempPath(MAX_PATH, temp_dir);
 187     GetTempFileName(temp_dir, "qem", 0, filename);
 188 }
 189 #else
 190 void get_tmp_filename(char *filename, int size)
 191 {
 192     int fd;
 193     const char *tmpdir;
 194     /* XXX: race condition possible */
 195     tmpdir = getenv("TMPDIR");
 196     if (!tmpdir)
 197         tmpdir = "/tmp";
 198     snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
 199     fd = mkstemp(filename);
 200     close(fd);
 201 }
 202 #endif
 203
 204 #ifdef _WIN32
 205 static int is_windows_drive_prefix(const char *filename)
 206 {
 207     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
 208              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 209             filename[1] == ':');
 210 }
 211
 212 static int is_windows_drive(const char *filename)
 213 {
 214     if (is_windows_drive_prefix(filename) &&
 215         filename[2] == '\0')
 216         return 1;
 217     if (strstart(filename, "\\\\.\\", NULL) ||
 218         strstart(filename, "//./", NULL))
 219         return 1;
 220     return 0;
 221 }
 222 #endif
 223
 224 static BlockDriver *find_protocol(const char *filename)
 225 {
 226     BlockDriver *drv1;
 227     char protocol[128];
 228     int len;
 229     const char *p;
 230
 231 #ifdef _WIN32
 232     if (is_windows_drive(filename) ||
 233         is_windows_drive_prefix(filename))
 234         return &bdrv_raw;
 235 #endif
 236     p = strchr(filename, ':');
 237     if (!p)
 238         return &bdrv_raw;
 239     len = p - filename;
 240     if (len > sizeof(protocol) - 1)
 241         len = sizeof(protocol) - 1;
 242     memcpy(protocol, filename, len);
 243     protocol[len] = '\0';
 244     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 245         if (drv1->protocol_name &&
 246             !strcmp(drv1->protocol_name, protocol))
 247             return drv1;
 248     }
 249     return NULL;
 250 }
 251
 252 /* XXX: force raw format if block or character device ? It would
 253    simplify the BSD case */
 254 static BlockDriver *find_image_format(const char *filename)
 255 {
 256     int ret, score, score_max;
 257     BlockDriver *drv1, *drv;
 258     uint8_t buf[2048];
 259     BlockDriverState *bs;
 260
 261     /* detect host devices. By convention, /dev/cdrom[N] is always
 262        recognized as a host CDROM */
 263     if (strstart(filename, "/dev/cdrom", NULL))
 264         return &bdrv_host_device;
 265 #ifdef _WIN32
 266     if (is_windows_drive(filename))
 267         return &bdrv_host_device;
 268 #else
 269     {
 270         struct stat st;
 271         if (stat(filename, &st) >= 0 &&
 272             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
 273             return &bdrv_host_device;
 274         }
 275     }
 276 #endif
 277
 278     drv = find_protocol(filename);
 279     /* no need to test disk image formats for vvfat */
 280     if (drv == &bdrv_vvfat)
 281         return drv;
 282
 283     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
 284     if (ret < 0)
 285         return NULL;
 286     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
 287     bdrv_delete(bs);
 288     if (ret < 0) {
 289         return NULL;
 290     }
 291
 292     score_max = 0;
 293     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 294         if (drv1->bdrv_probe) {
 295             score = drv1->bdrv_probe(buf, ret, filename);
 296             if (score > score_max) {
 297                 score_max = score;
 298                 drv = drv1;
 299             }
 300         }
 301     }
 302     return drv;
 303 }
 304
 305 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 306 {
 307     BlockDriverState *bs;
 308     int ret;
 309
 310     bs = bdrv_new("");
 311     if (!bs)
 312         return -ENOMEM;
 313     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
 314     if (ret < 0) {
 315         bdrv_delete(bs);
 316         return ret;
 317     }
 318     *pbs = bs;
 319     return 0;
 320 }
 321
 322 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
 323 {
 324     return bdrv_open2(bs, filename, flags, NULL);
 325 }
 326
 327 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 328                BlockDriver *drv)
 329 {
 330     int ret, open_flags;
 331     char tmp_filename[PATH_MAX];
 332     char backing_filename[PATH_MAX];
 333
 334     bs->read_only = 0;
 335     bs->is_temporary = 0;
 336     bs->encrypted = 0;
 337
 338     if (flags & BDRV_O_SNAPSHOT) {
 339         BlockDriverState *bs1;
 340         int64_t total_size;
 341         int is_protocol = 0;
 342
 343         /* if snapshot, we create a temporary backing file and open it
 344            instead of opening 'filename' directly */
 345
 346         /* if there is a backing file, use it */
 347         bs1 = bdrv_new("");
 348         if (!bs1) {
 349             return -ENOMEM;
 350         }
 351         if (bdrv_open(bs1, filename, 0) < 0) {
 352             bdrv_delete(bs1);
 353             return -1;
 354         }
 355         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
 356
 357         if (bs1->drv && bs1->drv->protocol_name)
 358             is_protocol = 1;
 359
 360         bdrv_delete(bs1);
 361
 362         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 363
 364         /* Real path is meaningless for protocols */
 365         if (is_protocol)
 366             snprintf(backing_filename, sizeof(backing_filename),
 367                      "%s", filename);
 368         else
 369             realpath(filename, backing_filename);
 370
 371         if (bdrv_create(&bdrv_qcow2, tmp_filename,
 372                         total_size, backing_filename, 0) < 0) {
 373             return -1;
 374         }
 375         filename = tmp_filename;
 376         bs->is_temporary = 1;
 377     }
 378
 379     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 380     if (flags & BDRV_O_FILE) {
 381         drv = find_protocol(filename);
 382         if (!drv)
 383             return -ENOENT;
 384     } else {
 385         if (!drv) {
 386             drv = find_image_format(filename);
 387             if (!drv)
 388                 return -1;
 389         }
 390     }
 391     bs->drv = drv;
 392     bs->opaque = qemu_mallocz(drv->instance_size);
 393     if (bs->opaque == NULL && drv->instance_size > 0)
 394         return -1;
 395     /* Note: for compatibility, we open disk image files as RDWR, and
 396        RDONLY as fallback */
 397     if (!(flags & BDRV_O_FILE))
 398         open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
 399     else
 400         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
 401     ret = drv->bdrv_open(bs, filename, open_flags);
 402     if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
 403         ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
 404         bs->read_only = 1;
 405     }
 406     if (ret < 0) {
 407         qemu_free(bs->opaque);
 408         bs->opaque = NULL;
 409         bs->drv = NULL;
 410         return ret;
 411     }
 412     if (drv->bdrv_getlength) {
 413         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 414     }
 415 #ifndef _WIN32
 416     if (bs->is_temporary) {
 417         unlink(filename);
 418     }
 419 #endif
 420     if (bs->backing_file[0] != '\0') {
 421         /* if there is a backing file, use it */
 422         bs->backing_hd = bdrv_new("");
 423         if (!bs->backing_hd) {
 424         fail:
 425             bdrv_close(bs);
 426             return -ENOMEM;
 427         }
 428         path_combine(backing_filename, sizeof(backing_filename),
 429                      filename, bs->backing_file);
 430         if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
 431             goto fail;
 432     }
 433
 434     /* call the change callback */
 435     bs->media_changed = 1;
 436     if (bs->change_cb)
 437         bs->change_cb(bs->change_opaque);
 438
 439     return 0;
 440 }
 441
 442 void bdrv_close(BlockDriverState *bs)
 443 {
 444     if (bs->drv) {
 445         if (bs->backing_hd)
 446             bdrv_delete(bs->backing_hd);
 447         bs->drv->bdrv_close(bs);
 448         qemu_free(bs->opaque);
 449 #ifdef _WIN32
 450         if (bs->is_temporary) {
 451             unlink(bs->filename);
 452         }
 453 #endif
 454         bs->opaque = NULL;
 455         bs->drv = NULL;
 456
 457         /* call the change callback */
 458         bs->media_changed = 1;
 459         if (bs->change_cb)
 460             bs->change_cb(bs->change_opaque);
 461     }
 462 }
 463
 464 void bdrv_delete(BlockDriverState *bs)
 465 {
 466     BlockDriverState **pbs;
 467
 468     pbs = &bdrv_first;
 469     while (*pbs != bs && *pbs != NULL)
 470         pbs = &(*pbs)->next;
 471     if (*pbs == bs)
 472         *pbs = bs->next;
 473
 474     bdrv_close(bs);
 475     qemu_free(bs);
 476 }
 477
 478 /* commit COW file into the raw image */
 479 int bdrv_commit(BlockDriverState *bs)
 480 {
 481     BlockDriver *drv = bs->drv;
 482     int64_t i, total_sectors;
 483     int n, j;
 484     unsigned char sector[512];
 485
 486     if (!drv)
 487         return -ENOMEDIUM;
 488
 489     if (bs->read_only) {
 490         return -EACCES;
 491     }
 492
 493     if (!bs->backing_hd) {
 494         return -ENOTSUP;
 495     }
 496
 497     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 498     for (i = 0; i < total_sectors;) {
 499         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 500             for(j = 0; j < n; j++) {
 501                 if (bdrv_read(bs, i, sector, 1) != 0) {
 502                     return -EIO;
 503                 }
 504
 505                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 506                     return -EIO;
 507                 }
 508                 i++;
 509             }
 510         } else {
 511             i += n;
 512         }
 513     }
 514
 515     if (drv->bdrv_make_empty)
 516         return drv->bdrv_make_empty(bs);
 517
 518     return 0;
 519 }
 520
 521 /* return < 0 if error. See bdrv_write() for the return codes */
 522 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 523               uint8_t *buf, int nb_sectors)
 524 {
 525     BlockDriver *drv = bs->drv;
 526
 527     if (!drv)
 528         return -ENOMEDIUM;
 529
 530     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 531             memcpy(buf, bs->boot_sector_data, 512);
 532         sector_num++;
 533         nb_sectors--;
 534         buf += 512;
 535         if (nb_sectors == 0)
 536             return 0;
 537     }
 538     if (drv->bdrv_pread) {
 539         int ret, len;
 540         len = nb_sectors * 512;
 541         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 542         if (ret < 0)
 543             return ret;
 544         else if (ret != len)
 545             return -EINVAL;
 546         else {
 547             bs->rd_bytes += (unsigned) len;
 548             bs->rd_ops ++;
 549             return 0;
 550         }
 551     } else {
 552         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 553     }
 554 }
 555
 556 /* Return < 0 if error. Important errors are:
 557   -EIO         generic I/O error (may happen for all errors)
 558   -ENOMEDIUM   No media inserted.
 559   -EINVAL      Invalid sector number or nb_sectors
 560   -EACCES      Trying to write a read-only device
 561 */
 562 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 563                const uint8_t *buf, int nb_sectors)
 564 {
 565     BlockDriver *drv = bs->drv;
 566     if (!bs->drv)
 567         return -ENOMEDIUM;
 568     if (bs->read_only)
 569         return -EACCES;
 570     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 571         memcpy(bs->boot_sector_data, buf, 512);
 572     }
 573     if (drv->bdrv_pwrite) {
 574         int ret, len;
 575         len = nb_sectors * 512;
 576         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 577         if (ret < 0)
 578             return ret;
 579         else if (ret != len)
 580             return -EIO;
 581         else {
 582             bs->wr_bytes += (unsigned) len;
 583             bs->wr_ops ++;
 584             return 0;
 585         }
 586     } else {
 587         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 588     }
 589 }
 590
 591 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 592                          uint8_t *buf, int count1)
 593 {
 594     uint8_t tmp_buf[SECTOR_SIZE];
 595     int len, nb_sectors, count;
 596     int64_t sector_num;
 597
 598     count = count1;
 599     /* first read to align to sector start */
 600     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 601     if (len > count)
 602         len = count;
 603     sector_num = offset >> SECTOR_BITS;
 604     if (len > 0) {
 605         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 606             return -EIO;
 607         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 608         count -= len;
 609         if (count == 0)
 610             return count1;
 611         sector_num++;
 612         buf += len;
 613     }
 614
 615     /* read the sectors "in place" */
 616     nb_sectors = count >> SECTOR_BITS;
 617     if (nb_sectors > 0) {
 618         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 619             return -EIO;
 620         sector_num += nb_sectors;
 621         len = nb_sectors << SECTOR_BITS;
 622         buf += len;
 623         count -= len;
 624     }
 625
 626     /* add data from the last sector */
 627     if (count > 0) {
 628         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 629             return -EIO;
 630         memcpy(buf, tmp_buf, count);
 631     }
 632     return count1;
 633 }
 634
 635 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 636                           const uint8_t *buf, int count1)
 637 {
 638     uint8_t tmp_buf[SECTOR_SIZE];
 639     int len, nb_sectors, count;
 640     int64_t sector_num;
 641
 642     count = count1;
 643     /* first write to align to sector start */
 644     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 645     if (len > count)
 646         len = count;
 647     sector_num = offset >> SECTOR_BITS;
 648     if (len > 0) {
 649         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 650             return -EIO;
 651         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 652         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 653             return -EIO;
 654         count -= len;
 655         if (count == 0)
 656             return count1;
 657         sector_num++;
 658         buf += len;
 659     }
 660
 661     /* write the sectors "in place" */
 662     nb_sectors = count >> SECTOR_BITS;
 663     if (nb_sectors > 0) {
 664         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 665             return -EIO;
 666         sector_num += nb_sectors;
 667         len = nb_sectors << SECTOR_BITS;
 668         buf += len;
 669         count -= len;
 670     }
 671
 672     /* add data from the last sector */
 673     if (count > 0) {
 674         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 675             return -EIO;
 676         memcpy(tmp_buf, buf, count);
 677         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 678             return -EIO;
 679     }
 680     return count1;
 681 }
 682
 683 /**
 684  * Read with byte offsets (needed only for file protocols)
 685  */
 686 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 687                void *buf1, int count1)
 688 {
 689     BlockDriver *drv = bs->drv;
 690
 691     if (!drv)
 692         return -ENOMEDIUM;
 693     if (!drv->bdrv_pread)
 694         return bdrv_pread_em(bs, offset, buf1, count1);
 695     return drv->bdrv_pread(bs, offset, buf1, count1);
 696 }
 697
 698 /**
 699  * Write with byte offsets (needed only for file protocols)
 700  */
 701 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 702                 const void *buf1, int count1)
 703 {
 704     BlockDriver *drv = bs->drv;
 705
 706     if (!drv)
 707         return -ENOMEDIUM;
 708     if (!drv->bdrv_pwrite)
 709         return bdrv_pwrite_em(bs, offset, buf1, count1);
 710     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 711 }
 712
 713 /**
 714  * Truncate file to 'offset' bytes (needed only for file protocols)
 715  */
 716 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 717 {
 718     BlockDriver *drv = bs->drv;
 719     if (!drv)
 720         return -ENOMEDIUM;
 721     if (!drv->bdrv_truncate)
 722         return -ENOTSUP;
 723     return drv->bdrv_truncate(bs, offset);
 724 }
 725
 726 /**
 727  * Length of a file in bytes. Return < 0 if error or unknown.
 728  */
 729 int64_t bdrv_getlength(BlockDriverState *bs)
 730 {
 731     BlockDriver *drv = bs->drv;
 732     if (!drv)
 733         return -ENOMEDIUM;
 734     if (!drv->bdrv_getlength) {
 735         /* legacy mode */
 736         return bs->total_sectors * SECTOR_SIZE;
 737     }
 738     return drv->bdrv_getlength(bs);
 739 }
 740
 741 /* return 0 as number of sectors if no device present or error */
 742 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 743 {
 744     int64_t length;
 745     length = bdrv_getlength(bs);
 746     if (length < 0)
 747         length = 0;
 748     else
 749         length = length >> SECTOR_BITS;
 750     *nb_sectors_ptr = length;
 751 }
 752
 753 /* force a given boot sector. */
 754 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 755 {
 756     bs->boot_sector_enabled = 1;
 757     if (size > 512)
 758         size = 512;
 759     memcpy(bs->boot_sector_data, data, size);
 760     memset(bs->boot_sector_data + size, 0, 512 - size);
 761 }
 762
 763 void bdrv_set_geometry_hint(BlockDriverState *bs,
 764                             int cyls, int heads, int secs)
 765 {
 766     bs->cyls = cyls;
 767     bs->heads = heads;
 768     bs->secs = secs;
 769 }
 770
 771 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 772 {
 773     bs->type = type;
 774     bs->removable = ((type == BDRV_TYPE_CDROM ||
 775                       type == BDRV_TYPE_FLOPPY));
 776 }
 777
 778 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 779 {
 780     bs->translation = translation;
 781 }
 782
 783 void bdrv_get_geometry_hint(BlockDriverState *bs,
 784                             int *pcyls, int *pheads, int *psecs)
 785 {
 786     *pcyls = bs->cyls;
 787     *pheads = bs->heads;
 788     *psecs = bs->secs;
 789 }
 790
 791 int bdrv_get_type_hint(BlockDriverState *bs)
 792 {
 793     return bs->type;
 794 }
 795
 796 int bdrv_get_translation_hint(BlockDriverState *bs)
 797 {
 798     return bs->translation;
 799 }
 800
 801 int bdrv_is_removable(BlockDriverState *bs)
 802 {
 803     return bs->removable;
 804 }
 805
 806 int bdrv_is_read_only(BlockDriverState *bs)
 807 {
 808     return bs->read_only;
 809 }
 810
 811 int bdrv_is_sg(BlockDriverState *bs)
 812 {
 813     return bs->sg;
 814 }
 815
 816 /* XXX: no longer used */
 817 void bdrv_set_change_cb(BlockDriverState *bs,
 818                         void (*change_cb)(void *opaque), void *opaque)
 819 {
 820     bs->change_cb = change_cb;
 821     bs->change_opaque = opaque;
 822 }
 823
 824 int bdrv_is_encrypted(BlockDriverState *bs)
 825 {
 826     if (bs->backing_hd && bs->backing_hd->encrypted)
 827         return 1;
 828     return bs->encrypted;
 829 }
 830
 831 int bdrv_set_key(BlockDriverState *bs, const char *key)
 832 {
 833     int ret;
 834     if (bs->backing_hd && bs->backing_hd->encrypted) {
 835         ret = bdrv_set_key(bs->backing_hd, key);
 836         if (ret < 0)
 837             return ret;
 838         if (!bs->encrypted)
 839             return 0;
 840     }
 841     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 842         return -1;
 843     return bs->drv->bdrv_set_key(bs, key);
 844 }
 845
 846 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 847 {
 848     if (!bs->drv) {
 849         buf[0] = '\0';
 850     } else {
 851         pstrcpy(buf, buf_size, bs->drv->format_name);
 852     }
 853 }
 854
 855 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 856                          void *opaque)
 857 {
 858     BlockDriver *drv;
 859
 860     for (drv = first_drv; drv != NULL; drv = drv->next) {
 861         it(opaque, drv->format_name);
 862     }
 863 }
 864
 865 BlockDriverState *bdrv_find(const char *name)
 866 {
 867     BlockDriverState *bs;
 868
 869     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 870         if (!strcmp(name, bs->device_name))
 871             return bs;
 872     }
 873     return NULL;
 874 }
 875
 876 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 877 {
 878     BlockDriverState *bs;
 879
 880     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 881         it(opaque, bs->device_name);
 882     }
 883 }
 884
 885 const char *bdrv_get_device_name(BlockDriverState *bs)
 886 {
 887     return bs->device_name;
 888 }
 889
 890 void bdrv_flush(BlockDriverState *bs)
 891 {
 892     if (bs->drv->bdrv_flush)
 893         bs->drv->bdrv_flush(bs);
 894     if (bs->backing_hd)
 895         bdrv_flush(bs->backing_hd);
 896 }
 897
 898 /*
 899  * Returns true iff the specified sector is present in the disk image. Drivers
 900  * not implementing the functionality are assumed to not support backing files,
 901  * hence all their sectors are reported as allocated.
 902  *
 903  * 'pnum' is set to the number of sectors (including and immediately following
 904  * the specified sector) that are known to be in the same
 905  * allocated/unallocated state.
 906  *
 907  * 'nb_sectors' is the max value 'pnum' should be set to.
 908  */
 909 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 910         int *pnum)
 911 {
 912     int64_t n;
 913     if (!bs->drv->bdrv_is_allocated) {
 914         if (sector_num >= bs->total_sectors) {
 915             *pnum = 0;
 916             return 0;
 917         }
 918         n = bs->total_sectors - sector_num;
 919         *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
 920         return 1;
 921     }
 922     return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
 923 }
 924
 925 void bdrv_info(void)
 926 {
 927     BlockDriverState *bs;
 928
 929     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 930         term_printf("%s:", bs->device_name);
 931         term_printf(" type=");
 932         switch(bs->type) {
 933         case BDRV_TYPE_HD:
 934             term_printf("hd");
 935             break;
 936         case BDRV_TYPE_CDROM:
 937             term_printf("cdrom");
 938             break;
 939         case BDRV_TYPE_FLOPPY:
 940             term_printf("floppy");
 941             break;
 942         }
 943         term_printf(" removable=%d", bs->removable);
 944         if (bs->removable) {
 945             term_printf(" locked=%d", bs->locked);
 946         }
 947         if (bs->drv) {
 948             term_printf(" file=");
 949             term_print_filename(bs->filename);
 950             if (bs->backing_file[0] != '\0') {
 951                 term_printf(" backing_file=");
 952                 term_print_filename(bs->backing_file);
 953             }
 954             term_printf(" ro=%d", bs->read_only);
 955             term_printf(" drv=%s", bs->drv->format_name);
 956             if (bs->encrypted)
 957                 term_printf(" encrypted");
 958         } else {
 959             term_printf(" [not inserted]");
 960         }
 961         term_printf("\n");
 962     }
 963 }
 964
 965 /* The "info blockstats" command. */
 966 void bdrv_info_stats (void)
 967 {
 968     BlockDriverState *bs;
 969
 970     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 971         term_printf ("%s:"
 972                      " rd_bytes=%" PRIu64
 973                      " wr_bytes=%" PRIu64
 974                      " rd_operations=%" PRIu64
 975                      " wr_operations=%" PRIu64
 976                      "\n",
 977                      bs->device_name,
 978                      bs->rd_bytes, bs->wr_bytes,
 979                      bs->rd_ops, bs->wr_ops);
 980     }
 981 }
 982
 983 void bdrv_get_backing_filename(BlockDriverState *bs,
 984                                char *filename, int filename_size)
 985 {
 986     if (!bs->backing_hd) {
 987         pstrcpy(filename, filename_size, "");
 988     } else {
 989         pstrcpy(filename, filename_size, bs->backing_file);
 990     }
 991 }
 992
 993 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
 994                           const uint8_t *buf, int nb_sectors)
 995 {
 996     BlockDriver *drv = bs->drv;
 997     if (!drv)
 998         return -ENOMEDIUM;
 999     if (!drv->bdrv_write_compressed)
1000         return -ENOTSUP;
1001     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1002 }
1003
1004 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1005 {
1006     BlockDriver *drv = bs->drv;
1007     if (!drv)
1008         return -ENOMEDIUM;
1009     if (!drv->bdrv_get_info)
1010         return -ENOTSUP;
1011     memset(bdi, 0, sizeof(*bdi));
1012     return drv->bdrv_get_info(bs, bdi);
1013 }
1014
1015 /**************************************************************/
1016 /* handling of snapshots */
1017
1018 int bdrv_snapshot_create(BlockDriverState *bs,
1019                          QEMUSnapshotInfo *sn_info)
1020 {
1021     BlockDriver *drv = bs->drv;
1022     if (!drv)
1023         return -ENOMEDIUM;
1024     if (!drv->bdrv_snapshot_create)
1025         return -ENOTSUP;
1026     return drv->bdrv_snapshot_create(bs, sn_info);
1027 }
1028
1029 int bdrv_snapshot_goto(BlockDriverState *bs,
1030                        const char *snapshot_id)
1031 {
1032     BlockDriver *drv = bs->drv;
1033     if (!drv)
1034         return -ENOMEDIUM;
1035     if (!drv->bdrv_snapshot_goto)
1036         return -ENOTSUP;
1037     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1038 }
1039
1040 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1041 {
1042     BlockDriver *drv = bs->drv;
1043     if (!drv)
1044         return -ENOMEDIUM;
1045     if (!drv->bdrv_snapshot_delete)
1046         return -ENOTSUP;
1047     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1048 }
1049
1050 int bdrv_snapshot_list(BlockDriverState *bs,
1051                        QEMUSnapshotInfo **psn_info)
1052 {
1053     BlockDriver *drv = bs->drv;
1054     if (!drv)
1055         return -ENOMEDIUM;
1056     if (!drv->bdrv_snapshot_list)
1057         return -ENOTSUP;
1058     return drv->bdrv_snapshot_list(bs, psn_info);
1059 }
1060
1061 #define NB_SUFFIXES 4
1062
1063 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1064 {
1065     static const char suffixes[NB_SUFFIXES] = "KMGT";
1066     int64_t base;
1067     int i;
1068
1069     if (size <= 999) {
1070         snprintf(buf, buf_size, "%" PRId64, size);
1071     } else {
1072         base = 1024;
1073         for(i = 0; i < NB_SUFFIXES; i++) {
1074             if (size < (10 * base)) {
1075                 snprintf(buf, buf_size, "%0.1f%c",
1076                          (double)size / base,
1077                          suffixes[i]);
1078                 break;
1079             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1080                 snprintf(buf, buf_size, "%" PRId64 "%c",
1081                          ((size + (base >> 1)) / base),
1082                          suffixes[i]);
1083                 break;
1084             }
1085             base = base * 1024;
1086         }
1087     }
1088     return buf;
1089 }
1090
1091 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1092 {
1093     char buf1[128], date_buf[128], clock_buf[128];
1094 #ifdef _WIN32
1095     struct tm *ptm;
1096 #else
1097     struct tm tm;
1098 #endif
1099     time_t ti;
1100     int64_t secs;
1101
1102     if (!sn) {
1103         snprintf(buf, buf_size,
1104                  "%-10s%-20s%7s%20s%15s",
1105                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1106     } else {
1107         ti = sn->date_sec;
1108 #ifdef _WIN32
1109         ptm = localtime(&ti);
1110         strftime(date_buf, sizeof(date_buf),
1111                  "%Y-%m-%d %H:%M:%S", ptm);
1112 #else
1113         localtime_r(&ti, &tm);
1114         strftime(date_buf, sizeof(date_buf),
1115                  "%Y-%m-%d %H:%M:%S", &tm);
1116 #endif
1117         secs = sn->vm_clock_nsec / 1000000000;
1118         snprintf(clock_buf, sizeof(clock_buf),
1119                  "%02d:%02d:%02d.%03d",
1120                  (int)(secs / 3600),
1121                  (int)((secs / 60) % 60),
1122                  (int)(secs % 60),
1123                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1124         snprintf(buf, buf_size,
1125                  "%-10s%-20s%7s%20s%15s",
1126                  sn->id_str, sn->name,
1127                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1128                  date_buf,
1129                  clock_buf);
1130     }
1131     return buf;
1132 }
1133
1134
1135 /**************************************************************/
1136 /* async I/Os */
1137
1138 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1139                                 uint8_t *buf, int nb_sectors,
1140                                 BlockDriverCompletionFunc *cb, void *opaque)
1141 {
1142     BlockDriver *drv = bs->drv;
1143     BlockDriverAIOCB *ret;
1144
1145     if (!drv)
1146         return NULL;
1147
1148     /* XXX: we assume that nb_sectors == 0 is suppored by the async read */
1149     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1150         memcpy(buf, bs->boot_sector_data, 512);
1151         sector_num++;
1152         nb_sectors--;
1153         buf += 512;
1154     }
1155
1156     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1157
1158     if (ret) {
1159         /* Update stats even though technically transfer has not happened. */
1160         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1161         bs->rd_ops ++;
1162     }
1163
1164     return ret;
1165 }
1166
1167 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1168                                  const uint8_t *buf, int nb_sectors,
1169                                  BlockDriverCompletionFunc *cb, void *opaque)
1170 {
1171     BlockDriver *drv = bs->drv;
1172     BlockDriverAIOCB *ret;
1173
1174     if (!drv)
1175         return NULL;
1176     if (bs->read_only)
1177         return NULL;
1178     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1179         memcpy(bs->boot_sector_data, buf, 512);
1180     }
1181
1182     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1183
1184     if (ret) {
1185         /* Update stats even though technically transfer has not happened. */
1186         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1187         bs->wr_ops ++;
1188     }
1189
1190     return ret;
1191 }
1192
1193 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1194 {
1195     BlockDriver *drv = acb->bs->drv;
1196
1197     drv->bdrv_aio_cancel(acb);
1198 }
1199
1200
1201 /**************************************************************/
1202 /* async block device emulation */
1203
1204 static void bdrv_aio_bh_cb(void *opaque)
1205 {
1206     BlockDriverAIOCBSync *acb = opaque;
1207     acb->common.cb(acb->common.opaque, acb->ret);
1208     qemu_aio_release(acb);
1209 }
1210
1211 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1212         int64_t sector_num, uint8_t *buf, int nb_sectors,
1213         BlockDriverCompletionFunc *cb, void *opaque)
1214 {
1215     BlockDriverAIOCBSync *acb;
1216     int ret;
1217
1218     acb = qemu_aio_get(bs, cb, opaque);
1219     if (!acb->bh)
1220         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1221     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1222     acb->ret = ret;
1223     qemu_bh_schedule(acb->bh);
1224     return &acb->common;
1225 }
1226
1227 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1228         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1229         BlockDriverCompletionFunc *cb, void *opaque)
1230 {
1231     BlockDriverAIOCBSync *acb;
1232     int ret;
1233
1234     acb = qemu_aio_get(bs, cb, opaque);
1235     if (!acb->bh)
1236         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1237     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1238     acb->ret = ret;
1239     qemu_bh_schedule(acb->bh);
1240     return &acb->common;
1241 }
1242
1243 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1244 {
1245     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1246     qemu_bh_cancel(acb->bh);
1247     qemu_aio_release(acb);
1248 }
1249
1250 /**************************************************************/
1251 /* sync block device emulation */
1252
1253 static void bdrv_rw_em_cb(void *opaque, int ret)
1254 {
1255     *(int *)opaque = ret;
1256 }
1257
1258 #define NOT_DONE 0x7fffffff
1259
1260 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1261                         uint8_t *buf, int nb_sectors)
1262 {
1263     int async_ret;
1264     BlockDriverAIOCB *acb;
1265
1266     async_ret = NOT_DONE;
1267     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1268                         bdrv_rw_em_cb, &async_ret);
1269     if (acb == NULL)
1270         return -1;
1271
1272     while (async_ret == NOT_DONE) {
1273         qemu_aio_wait();
1274     }
1275
1276     return async_ret;
1277 }
1278
1279 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1280                          const uint8_t *buf, int nb_sectors)
1281 {
1282     int async_ret;
1283     BlockDriverAIOCB *acb;
1284
1285     async_ret = NOT_DONE;
1286     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1287                          bdrv_rw_em_cb, &async_ret);
1288     if (acb == NULL)
1289         return -1;
1290     while (async_ret == NOT_DONE) {
1291         qemu_aio_wait();
1292     }
1293     return async_ret;
1294 }
1295
1296 void bdrv_init(void)
1297 {
1298     bdrv_register(&bdrv_raw);
1299     bdrv_register(&bdrv_host_device);
1300 #ifndef _WIN32
1301     bdrv_register(&bdrv_cow);
1302 #endif
1303     bdrv_register(&bdrv_qcow);
1304     bdrv_register(&bdrv_vmdk);
1305     bdrv_register(&bdrv_cloop);
1306     bdrv_register(&bdrv_dmg);
1307     bdrv_register(&bdrv_bochs);
1308     bdrv_register(&bdrv_vpc);
1309     bdrv_register(&bdrv_vvfat);
1310     bdrv_register(&bdrv_qcow2);
1311     bdrv_register(&bdrv_parallels);
1312     bdrv_register(&bdrv_nbd);
1313
1314     qemu_aio_init();
1315 }
1316
1317 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1318                    void *opaque)
1319 {
1320     BlockDriver *drv;
1321     BlockDriverAIOCB *acb;
1322
1323     drv = bs->drv;
1324     if (drv->free_aiocb) {
1325         acb = drv->free_aiocb;
1326         drv->free_aiocb = acb->next;
1327     } else {
1328         acb = qemu_mallocz(drv->aiocb_size);
1329         if (!acb)
1330             return NULL;
1331     }
1332     acb->bs = bs;
1333     acb->cb = cb;
1334     acb->opaque = opaque;
1335     return acb;
1336 }
1337
1338 void qemu_aio_release(void *p)
1339 {
1340     BlockDriverAIOCB *acb = p;
1341     BlockDriver *drv = acb->bs->drv;
1342     acb->next = drv->free_aiocb;
1343     drv->free_aiocb = acb;
1344 }
1345
1346 /**************************************************************/
1347 /* removable device support */
1348
1349 /**
1350  * Return TRUE if the media is present
1351  */
1352 int bdrv_is_inserted(BlockDriverState *bs)
1353 {
1354     BlockDriver *drv = bs->drv;
1355     int ret;
1356     if (!drv)
1357         return 0;
1358     if (!drv->bdrv_is_inserted)
1359         return 1;
1360     ret = drv->bdrv_is_inserted(bs);
1361     return ret;
1362 }
1363
1364 /**
1365  * Return TRUE if the media changed since the last call to this
1366  * function. It is currently only used for floppy disks
1367  */
1368 int bdrv_media_changed(BlockDriverState *bs)
1369 {
1370     BlockDriver *drv = bs->drv;
1371     int ret;
1372
1373     if (!drv || !drv->bdrv_media_changed)
1374         ret = -ENOTSUP;
1375     else
1376         ret = drv->bdrv_media_changed(bs);
1377     if (ret == -ENOTSUP)
1378         ret = bs->media_changed;
1379     bs->media_changed = 0;
1380     return ret;
1381 }
1382
1383 /**
1384  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1385  */
1386 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1387 {
1388     BlockDriver *drv = bs->drv;
1389     int ret;
1390
1391     if (!drv || !drv->bdrv_eject) {
1392         ret = -ENOTSUP;
1393     } else {
1394         ret = drv->bdrv_eject(bs, eject_flag);
1395     }
1396     if (ret == -ENOTSUP) {
1397         if (eject_flag)
1398             bdrv_close(bs);
1399     }
1400 }
1401
1402 int bdrv_is_locked(BlockDriverState *bs)
1403 {
1404     return bs->locked;
1405 }
1406
1407 /**
1408  * Lock or unlock the media (if it is locked, the user won't be able
1409  * to eject it manually).
1410  */
1411 void bdrv_set_locked(BlockDriverState *bs, int locked)
1412 {
1413     BlockDriver *drv = bs->drv;
1414
1415     bs->locked = locked;
1416     if (drv && drv->bdrv_set_locked) {
1417         drv->bdrv_set_locked(bs, locked);
1418     }
1419 }
1420
1421 /* needed for generic scsi interface */
1422
1423 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1424 {
1425     BlockDriver *drv = bs->drv;
1426
1427     if (drv && drv->bdrv_ioctl)
1428         return drv->bdrv_ioctl(bs, req, buf);
1429     return -ENOTSUP;
1430 }