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