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_CACHE_MASK);
 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 || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
 403         ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
 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, open_flags) < 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 (drv->bdrv_pread) {
 531         int ret, len;
 532         len = nb_sectors * 512;
 533         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 534         if (ret < 0)
 535             return ret;
 536         else if (ret != len)
 537             return -EINVAL;
 538         else {
 539             bs->rd_bytes += (unsigned) len;
 540             bs->rd_ops ++;
 541             return 0;
 542         }
 543     } else {
 544         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 545     }
 546 }
 547
 548 /* Return < 0 if error. Important errors are:
 549   -EIO         generic I/O error (may happen for all errors)
 550   -ENOMEDIUM   No media inserted.
 551   -EINVAL      Invalid sector number or nb_sectors
 552   -EACCES      Trying to write a read-only device
 553 */
 554 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 555                const uint8_t *buf, int nb_sectors)
 556 {
 557     BlockDriver *drv = bs->drv;
 558     if (!bs->drv)
 559         return -ENOMEDIUM;
 560     if (bs->read_only)
 561         return -EACCES;
 562     if (drv->bdrv_pwrite) {
 563         int ret, len;
 564         len = nb_sectors * 512;
 565         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 566         if (ret < 0)
 567             return ret;
 568         else if (ret != len)
 569             return -EIO;
 570         else {
 571             bs->wr_bytes += (unsigned) len;
 572             bs->wr_ops ++;
 573             return 0;
 574         }
 575     } else {
 576         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 577     }
 578 }
 579
 580 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 581                          uint8_t *buf, int count1)
 582 {
 583     uint8_t tmp_buf[SECTOR_SIZE];
 584     int len, nb_sectors, count;
 585     int64_t sector_num;
 586
 587     count = count1;
 588     /* first read to align to sector start */
 589     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 590     if (len > count)
 591         len = count;
 592     sector_num = offset >> SECTOR_BITS;
 593     if (len > 0) {
 594         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 595             return -EIO;
 596         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 597         count -= len;
 598         if (count == 0)
 599             return count1;
 600         sector_num++;
 601         buf += len;
 602     }
 603
 604     /* read the sectors "in place" */
 605     nb_sectors = count >> SECTOR_BITS;
 606     if (nb_sectors > 0) {
 607         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 608             return -EIO;
 609         sector_num += nb_sectors;
 610         len = nb_sectors << SECTOR_BITS;
 611         buf += len;
 612         count -= len;
 613     }
 614
 615     /* add data from the last sector */
 616     if (count > 0) {
 617         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 618             return -EIO;
 619         memcpy(buf, tmp_buf, count);
 620     }
 621     return count1;
 622 }
 623
 624 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 625                           const uint8_t *buf, int count1)
 626 {
 627     uint8_t tmp_buf[SECTOR_SIZE];
 628     int len, nb_sectors, count;
 629     int64_t sector_num;
 630
 631     count = count1;
 632     /* first write to align to sector start */
 633     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 634     if (len > count)
 635         len = count;
 636     sector_num = offset >> SECTOR_BITS;
 637     if (len > 0) {
 638         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 639             return -EIO;
 640         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 641         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 642             return -EIO;
 643         count -= len;
 644         if (count == 0)
 645             return count1;
 646         sector_num++;
 647         buf += len;
 648     }
 649
 650     /* write the sectors "in place" */
 651     nb_sectors = count >> SECTOR_BITS;
 652     if (nb_sectors > 0) {
 653         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 654             return -EIO;
 655         sector_num += nb_sectors;
 656         len = nb_sectors << SECTOR_BITS;
 657         buf += len;
 658         count -= len;
 659     }
 660
 661     /* add data from the last sector */
 662     if (count > 0) {
 663         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 664             return -EIO;
 665         memcpy(tmp_buf, buf, count);
 666         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 667             return -EIO;
 668     }
 669     return count1;
 670 }
 671
 672 /**
 673  * Read with byte offsets (needed only for file protocols)
 674  */
 675 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 676                void *buf1, int count1)
 677 {
 678     BlockDriver *drv = bs->drv;
 679
 680     if (!drv)
 681         return -ENOMEDIUM;
 682     if (!drv->bdrv_pread)
 683         return bdrv_pread_em(bs, offset, buf1, count1);
 684     return drv->bdrv_pread(bs, offset, buf1, count1);
 685 }
 686
 687 /**
 688  * Write with byte offsets (needed only for file protocols)
 689  */
 690 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 691                 const void *buf1, int count1)
 692 {
 693     BlockDriver *drv = bs->drv;
 694
 695     if (!drv)
 696         return -ENOMEDIUM;
 697     if (!drv->bdrv_pwrite)
 698         return bdrv_pwrite_em(bs, offset, buf1, count1);
 699     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 700 }
 701
 702 /**
 703  * Truncate file to 'offset' bytes (needed only for file protocols)
 704  */
 705 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 706 {
 707     BlockDriver *drv = bs->drv;
 708     if (!drv)
 709         return -ENOMEDIUM;
 710     if (!drv->bdrv_truncate)
 711         return -ENOTSUP;
 712     return drv->bdrv_truncate(bs, offset);
 713 }
 714
 715 /**
 716  * Length of a file in bytes. Return < 0 if error or unknown.
 717  */
 718 int64_t bdrv_getlength(BlockDriverState *bs)
 719 {
 720     BlockDriver *drv = bs->drv;
 721     if (!drv)
 722         return -ENOMEDIUM;
 723     if (!drv->bdrv_getlength) {
 724         /* legacy mode */
 725         return bs->total_sectors * SECTOR_SIZE;
 726     }
 727     return drv->bdrv_getlength(bs);
 728 }
 729
 730 /* return 0 as number of sectors if no device present or error */
 731 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 732 {
 733     int64_t length;
 734     length = bdrv_getlength(bs);
 735     if (length < 0)
 736         length = 0;
 737     else
 738         length = length >> SECTOR_BITS;
 739     *nb_sectors_ptr = length;
 740 }
 741
 742 struct partition {
 743         uint8_t boot_ind;           /* 0x80 - active */
 744         uint8_t head;               /* starting head */
 745         uint8_t sector;             /* starting sector */
 746         uint8_t cyl;                /* starting cylinder */
 747         uint8_t sys_ind;            /* What partition type */
 748         uint8_t end_head;           /* end head */
 749         uint8_t end_sector;         /* end sector */
 750         uint8_t end_cyl;            /* end cylinder */
 751         uint32_t start_sect;        /* starting sector counting from 0 */
 752         uint32_t nr_sects;          /* nr of sectors in partition */
 753 } __attribute__((packed));
 754
 755 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
 756 static int guess_disk_lchs(BlockDriverState *bs,
 757                            int *pcylinders, int *pheads, int *psectors)
 758 {
 759     uint8_t buf[512];
 760     int ret, i, heads, sectors, cylinders;
 761     struct partition *p;
 762     uint32_t nr_sects;
 763     int64_t nb_sectors;
 764
 765     bdrv_get_geometry(bs, &nb_sectors);
 766
 767     ret = bdrv_read(bs, 0, buf, 1);
 768     if (ret < 0)
 769         return -1;
 770     /* test msdos magic */
 771     if (buf[510] != 0x55 || buf[511] != 0xaa)
 772         return -1;
 773     for(i = 0; i < 4; i++) {
 774         p = ((struct partition *)(buf + 0x1be)) + i;
 775         nr_sects = le32_to_cpu(p->nr_sects);
 776         if (nr_sects && p->end_head) {
 777             /* We make the assumption that the partition terminates on
 778                a cylinder boundary */
 779             heads = p->end_head + 1;
 780             sectors = p->end_sector & 63;
 781             if (sectors == 0)
 782                 continue;
 783             cylinders = nb_sectors / (heads * sectors);
 784             if (cylinders < 1 || cylinders > 16383)
 785                 continue;
 786             *pheads = heads;
 787             *psectors = sectors;
 788             *pcylinders = cylinders;
 789 #if 0
 790             printf("guessed geometry: LCHS=%d %d %d\n",
 791                    cylinders, heads, sectors);
 792 #endif
 793             return 0;
 794         }
 795     }
 796     return -1;
 797 }
 798
 799 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
 800 {
 801     int translation, lba_detected = 0;
 802     int cylinders, heads, secs;
 803     int64_t nb_sectors;
 804
 805     /* if a geometry hint is available, use it */
 806     bdrv_get_geometry(bs, &nb_sectors);
 807     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
 808     translation = bdrv_get_translation_hint(bs);
 809     if (cylinders != 0) {
 810         *pcyls = cylinders;
 811         *pheads = heads;
 812         *psecs = secs;
 813     } else {
 814         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
 815             if (heads > 16) {
 816                 /* if heads > 16, it means that a BIOS LBA
 817                    translation was active, so the default
 818                    hardware geometry is OK */
 819                 lba_detected = 1;
 820                 goto default_geometry;
 821             } else {
 822                 *pcyls = cylinders;
 823                 *pheads = heads;
 824                 *psecs = secs;
 825                 /* disable any translation to be in sync with
 826                    the logical geometry */
 827                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
 828                     bdrv_set_translation_hint(bs,
 829                                               BIOS_ATA_TRANSLATION_NONE);
 830                 }
 831             }
 832         } else {
 833         default_geometry:
 834             /* if no geometry, use a standard physical disk geometry */
 835             cylinders = nb_sectors / (16 * 63);
 836
 837             if (cylinders > 16383)
 838                 cylinders = 16383;
 839             else if (cylinders < 2)
 840                 cylinders = 2;
 841             *pcyls = cylinders;
 842             *pheads = 16;
 843             *psecs = 63;
 844             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
 845                 if ((*pcyls * *pheads) <= 131072) {
 846                     bdrv_set_translation_hint(bs,
 847                                               BIOS_ATA_TRANSLATION_LARGE);
 848                 } else {
 849                     bdrv_set_translation_hint(bs,
 850                                               BIOS_ATA_TRANSLATION_LBA);
 851                 }
 852             }
 853         }
 854         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
 855     }
 856 }
 857
 858 void bdrv_set_geometry_hint(BlockDriverState *bs,
 859                             int cyls, int heads, int secs)
 860 {
 861     bs->cyls = cyls;
 862     bs->heads = heads;
 863     bs->secs = secs;
 864 }
 865
 866 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 867 {
 868     bs->type = type;
 869     bs->removable = ((type == BDRV_TYPE_CDROM ||
 870                       type == BDRV_TYPE_FLOPPY));
 871 }
 872
 873 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 874 {
 875     bs->translation = translation;
 876 }
 877
 878 void bdrv_get_geometry_hint(BlockDriverState *bs,
 879                             int *pcyls, int *pheads, int *psecs)
 880 {
 881     *pcyls = bs->cyls;
 882     *pheads = bs->heads;
 883     *psecs = bs->secs;
 884 }
 885
 886 int bdrv_get_type_hint(BlockDriverState *bs)
 887 {
 888     return bs->type;
 889 }
 890
 891 int bdrv_get_translation_hint(BlockDriverState *bs)
 892 {
 893     return bs->translation;
 894 }
 895
 896 int bdrv_is_removable(BlockDriverState *bs)
 897 {
 898     return bs->removable;
 899 }
 900
 901 int bdrv_is_read_only(BlockDriverState *bs)
 902 {
 903     return bs->read_only;
 904 }
 905
 906 int bdrv_is_sg(BlockDriverState *bs)
 907 {
 908     return bs->sg;
 909 }
 910
 911 /* XXX: no longer used */
 912 void bdrv_set_change_cb(BlockDriverState *bs,
 913                         void (*change_cb)(void *opaque), void *opaque)
 914 {
 915     bs->change_cb = change_cb;
 916     bs->change_opaque = opaque;
 917 }
 918
 919 int bdrv_is_encrypted(BlockDriverState *bs)
 920 {
 921     if (bs->backing_hd && bs->backing_hd->encrypted)
 922         return 1;
 923     return bs->encrypted;
 924 }
 925
 926 int bdrv_set_key(BlockDriverState *bs, const char *key)
 927 {
 928     int ret;
 929     if (bs->backing_hd && bs->backing_hd->encrypted) {
 930         ret = bdrv_set_key(bs->backing_hd, key);
 931         if (ret < 0)
 932             return ret;
 933         if (!bs->encrypted)
 934             return 0;
 935     }
 936     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 937         return -1;
 938     return bs->drv->bdrv_set_key(bs, key);
 939 }
 940
 941 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 942 {
 943     if (!bs->drv) {
 944         buf[0] = '\0';
 945     } else {
 946         pstrcpy(buf, buf_size, bs->drv->format_name);
 947     }
 948 }
 949
 950 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 951                          void *opaque)
 952 {
 953     BlockDriver *drv;
 954
 955     for (drv = first_drv; drv != NULL; drv = drv->next) {
 956         it(opaque, drv->format_name);
 957     }
 958 }
 959
 960 BlockDriverState *bdrv_find(const char *name)
 961 {
 962     BlockDriverState *bs;
 963
 964     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 965         if (!strcmp(name, bs->device_name))
 966             return bs;
 967     }
 968     return NULL;
 969 }
 970
 971 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 972 {
 973     BlockDriverState *bs;
 974
 975     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 976         it(opaque, bs->device_name);
 977     }
 978 }
 979
 980 const char *bdrv_get_device_name(BlockDriverState *bs)
 981 {
 982     return bs->device_name;
 983 }
 984
 985 void bdrv_flush(BlockDriverState *bs)
 986 {
 987     if (bs->drv->bdrv_flush)
 988         bs->drv->bdrv_flush(bs);
 989     if (bs->backing_hd)
 990         bdrv_flush(bs->backing_hd);
 991 }
 992
 993 void bdrv_flush_all(void)
 994 {
 995     BlockDriverState *bs;
 996
 997     for (bs = bdrv_first; bs != NULL; bs = bs->next)
 998         if (bs->drv && !bdrv_is_read_only(bs) &&
 999             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1000             bdrv_flush(bs);
1001 }
1002
1003 /*
1004  * Returns true iff the specified sector is present in the disk image. Drivers
1005  * not implementing the functionality are assumed to not support backing files,
1006  * hence all their sectors are reported as allocated.
1007  *
1008  * 'pnum' is set to the number of sectors (including and immediately following
1009  * the specified sector) that are known to be in the same
1010  * allocated/unallocated state.
1011  *
1012  * 'nb_sectors' is the max value 'pnum' should be set to.
1013  */
1014 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1015         int *pnum)
1016 {
1017     int64_t n;
1018     if (!bs->drv->bdrv_is_allocated) {
1019         if (sector_num >= bs->total_sectors) {
1020             *pnum = 0;
1021             return 0;
1022         }
1023         n = bs->total_sectors - sector_num;
1024         *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1025         return 1;
1026     }
1027     return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1028 }
1029
1030 void bdrv_info(void)
1031 {
1032     BlockDriverState *bs;
1033
1034     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1035         term_printf("%s:", bs->device_name);
1036         term_printf(" type=");
1037         switch(bs->type) {
1038         case BDRV_TYPE_HD:
1039             term_printf("hd");
1040             break;
1041         case BDRV_TYPE_CDROM:
1042             term_printf("cdrom");
1043             break;
1044         case BDRV_TYPE_FLOPPY:
1045             term_printf("floppy");
1046             break;
1047         }
1048         term_printf(" removable=%d", bs->removable);
1049         if (bs->removable) {
1050             term_printf(" locked=%d", bs->locked);
1051         }
1052         if (bs->drv) {
1053             term_printf(" file=");
1054             term_print_filename(bs->filename);
1055             if (bs->backing_file[0] != '\0') {
1056                 term_printf(" backing_file=");
1057                 term_print_filename(bs->backing_file);
1058             }
1059             term_printf(" ro=%d", bs->read_only);
1060             term_printf(" drv=%s", bs->drv->format_name);
1061             if (bs->encrypted)
1062                 term_printf(" encrypted");
1063         } else {
1064             term_printf(" [not inserted]");
1065         }
1066         term_printf("\n");
1067     }
1068 }
1069
1070 /* The "info blockstats" command. */
1071 void bdrv_info_stats (void)
1072 {
1073     BlockDriverState *bs;
1074
1075     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1076         term_printf ("%s:"
1077                      " rd_bytes=%" PRIu64
1078                      " wr_bytes=%" PRIu64
1079                      " rd_operations=%" PRIu64
1080                      " wr_operations=%" PRIu64
1081                      "\n",
1082                      bs->device_name,
1083                      bs->rd_bytes, bs->wr_bytes,
1084                      bs->rd_ops, bs->wr_ops);
1085     }
1086 }
1087
1088 void bdrv_get_backing_filename(BlockDriverState *bs,
1089                                char *filename, int filename_size)
1090 {
1091     if (!bs->backing_hd) {
1092         pstrcpy(filename, filename_size, "");
1093     } else {
1094         pstrcpy(filename, filename_size, bs->backing_file);
1095     }
1096 }
1097
1098 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1099                           const uint8_t *buf, int nb_sectors)
1100 {
1101     BlockDriver *drv = bs->drv;
1102     if (!drv)
1103         return -ENOMEDIUM;
1104     if (!drv->bdrv_write_compressed)
1105         return -ENOTSUP;
1106     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1107 }
1108
1109 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1110 {
1111     BlockDriver *drv = bs->drv;
1112     if (!drv)
1113         return -ENOMEDIUM;
1114     if (!drv->bdrv_get_info)
1115         return -ENOTSUP;
1116     memset(bdi, 0, sizeof(*bdi));
1117     return drv->bdrv_get_info(bs, bdi);
1118 }
1119
1120 /**************************************************************/
1121 /* handling of snapshots */
1122
1123 int bdrv_snapshot_create(BlockDriverState *bs,
1124                          QEMUSnapshotInfo *sn_info)
1125 {
1126     BlockDriver *drv = bs->drv;
1127     if (!drv)
1128         return -ENOMEDIUM;
1129     if (!drv->bdrv_snapshot_create)
1130         return -ENOTSUP;
1131     return drv->bdrv_snapshot_create(bs, sn_info);
1132 }
1133
1134 int bdrv_snapshot_goto(BlockDriverState *bs,
1135                        const char *snapshot_id)
1136 {
1137     BlockDriver *drv = bs->drv;
1138     if (!drv)
1139         return -ENOMEDIUM;
1140     if (!drv->bdrv_snapshot_goto)
1141         return -ENOTSUP;
1142     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1143 }
1144
1145 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1146 {
1147     BlockDriver *drv = bs->drv;
1148     if (!drv)
1149         return -ENOMEDIUM;
1150     if (!drv->bdrv_snapshot_delete)
1151         return -ENOTSUP;
1152     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1153 }
1154
1155 int bdrv_snapshot_list(BlockDriverState *bs,
1156                        QEMUSnapshotInfo **psn_info)
1157 {
1158     BlockDriver *drv = bs->drv;
1159     if (!drv)
1160         return -ENOMEDIUM;
1161     if (!drv->bdrv_snapshot_list)
1162         return -ENOTSUP;
1163     return drv->bdrv_snapshot_list(bs, psn_info);
1164 }
1165
1166 #define NB_SUFFIXES 4
1167
1168 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1169 {
1170     static const char suffixes[NB_SUFFIXES] = "KMGT";
1171     int64_t base;
1172     int i;
1173
1174     if (size <= 999) {
1175         snprintf(buf, buf_size, "%" PRId64, size);
1176     } else {
1177         base = 1024;
1178         for(i = 0; i < NB_SUFFIXES; i++) {
1179             if (size < (10 * base)) {
1180                 snprintf(buf, buf_size, "%0.1f%c",
1181                          (double)size / base,
1182                          suffixes[i]);
1183                 break;
1184             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1185                 snprintf(buf, buf_size, "%" PRId64 "%c",
1186                          ((size + (base >> 1)) / base),
1187                          suffixes[i]);
1188                 break;
1189             }
1190             base = base * 1024;
1191         }
1192     }
1193     return buf;
1194 }
1195
1196 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1197 {
1198     char buf1[128], date_buf[128], clock_buf[128];
1199 #ifdef _WIN32
1200     struct tm *ptm;
1201 #else
1202     struct tm tm;
1203 #endif
1204     time_t ti;
1205     int64_t secs;
1206
1207     if (!sn) {
1208         snprintf(buf, buf_size,
1209                  "%-10s%-20s%7s%20s%15s",
1210                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1211     } else {
1212         ti = sn->date_sec;
1213 #ifdef _WIN32
1214         ptm = localtime(&ti);
1215         strftime(date_buf, sizeof(date_buf),
1216                  "%Y-%m-%d %H:%M:%S", ptm);
1217 #else
1218         localtime_r(&ti, &tm);
1219         strftime(date_buf, sizeof(date_buf),
1220                  "%Y-%m-%d %H:%M:%S", &tm);
1221 #endif
1222         secs = sn->vm_clock_nsec / 1000000000;
1223         snprintf(clock_buf, sizeof(clock_buf),
1224                  "%02d:%02d:%02d.%03d",
1225                  (int)(secs / 3600),
1226                  (int)((secs / 60) % 60),
1227                  (int)(secs % 60),
1228                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1229         snprintf(buf, buf_size,
1230                  "%-10s%-20s%7s%20s%15s",
1231                  sn->id_str, sn->name,
1232                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1233                  date_buf,
1234                  clock_buf);
1235     }
1236     return buf;
1237 }
1238
1239
1240 /**************************************************************/
1241 /* async I/Os */
1242
1243 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1244                                 uint8_t *buf, int nb_sectors,
1245                                 BlockDriverCompletionFunc *cb, void *opaque)
1246 {
1247     BlockDriver *drv = bs->drv;
1248     BlockDriverAIOCB *ret;
1249
1250     if (!drv)
1251         return NULL;
1252
1253     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1254
1255     if (ret) {
1256         /* Update stats even though technically transfer has not happened. */
1257         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1258         bs->rd_ops ++;
1259     }
1260
1261     return ret;
1262 }
1263
1264 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1265                                  const uint8_t *buf, int nb_sectors,
1266                                  BlockDriverCompletionFunc *cb, void *opaque)
1267 {
1268     BlockDriver *drv = bs->drv;
1269     BlockDriverAIOCB *ret;
1270
1271     if (!drv)
1272         return NULL;
1273     if (bs->read_only)
1274         return NULL;
1275
1276     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1277
1278     if (ret) {
1279         /* Update stats even though technically transfer has not happened. */
1280         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1281         bs->wr_ops ++;
1282     }
1283
1284     return ret;
1285 }
1286
1287 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1288 {
1289     BlockDriver *drv = acb->bs->drv;
1290
1291     drv->bdrv_aio_cancel(acb);
1292 }
1293
1294
1295 /**************************************************************/
1296 /* async block device emulation */
1297
1298 static void bdrv_aio_bh_cb(void *opaque)
1299 {
1300     BlockDriverAIOCBSync *acb = opaque;
1301     acb->common.cb(acb->common.opaque, acb->ret);
1302     qemu_aio_release(acb);
1303 }
1304
1305 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1306         int64_t sector_num, uint8_t *buf, int nb_sectors,
1307         BlockDriverCompletionFunc *cb, void *opaque)
1308 {
1309     BlockDriverAIOCBSync *acb;
1310     int ret;
1311
1312     acb = qemu_aio_get(bs, cb, opaque);
1313     if (!acb->bh)
1314         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1315     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1316     acb->ret = ret;
1317     qemu_bh_schedule(acb->bh);
1318     return &acb->common;
1319 }
1320
1321 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1322         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1323         BlockDriverCompletionFunc *cb, void *opaque)
1324 {
1325     BlockDriverAIOCBSync *acb;
1326     int ret;
1327
1328     acb = qemu_aio_get(bs, cb, opaque);
1329     if (!acb->bh)
1330         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1331     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1332     acb->ret = ret;
1333     qemu_bh_schedule(acb->bh);
1334     return &acb->common;
1335 }
1336
1337 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1338 {
1339     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1340     qemu_bh_cancel(acb->bh);
1341     qemu_aio_release(acb);
1342 }
1343
1344 /**************************************************************/
1345 /* sync block device emulation */
1346
1347 static void bdrv_rw_em_cb(void *opaque, int ret)
1348 {
1349     *(int *)opaque = ret;
1350 }
1351
1352 #define NOT_DONE 0x7fffffff
1353
1354 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1355                         uint8_t *buf, int nb_sectors)
1356 {
1357     int async_ret;
1358     BlockDriverAIOCB *acb;
1359
1360     async_ret = NOT_DONE;
1361     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1362                         bdrv_rw_em_cb, &async_ret);
1363     if (acb == NULL)
1364         return -1;
1365
1366     while (async_ret == NOT_DONE) {
1367         qemu_aio_wait();
1368     }
1369
1370     return async_ret;
1371 }
1372
1373 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1374                          const uint8_t *buf, int nb_sectors)
1375 {
1376     int async_ret;
1377     BlockDriverAIOCB *acb;
1378
1379     async_ret = NOT_DONE;
1380     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1381                          bdrv_rw_em_cb, &async_ret);
1382     if (acb == NULL)
1383         return -1;
1384     while (async_ret == NOT_DONE) {
1385         qemu_aio_wait();
1386     }
1387     return async_ret;
1388 }
1389
1390 void bdrv_init(void)
1391 {
1392     bdrv_register(&bdrv_raw);
1393     bdrv_register(&bdrv_host_device);
1394 #ifndef _WIN32
1395     bdrv_register(&bdrv_cow);
1396 #endif
1397     bdrv_register(&bdrv_qcow);
1398     bdrv_register(&bdrv_vmdk);
1399     bdrv_register(&bdrv_cloop);
1400     bdrv_register(&bdrv_dmg);
1401     bdrv_register(&bdrv_bochs);
1402     bdrv_register(&bdrv_vpc);
1403     bdrv_register(&bdrv_vvfat);
1404     bdrv_register(&bdrv_qcow2);
1405     bdrv_register(&bdrv_parallels);
1406     bdrv_register(&bdrv_nbd);
1407 }
1408
1409 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1410                    void *opaque)
1411 {
1412     BlockDriver *drv;
1413     BlockDriverAIOCB *acb;
1414
1415     drv = bs->drv;
1416     if (drv->free_aiocb) {
1417         acb = drv->free_aiocb;
1418         drv->free_aiocb = acb->next;
1419     } else {
1420         acb = qemu_mallocz(drv->aiocb_size);
1421         if (!acb)
1422             return NULL;
1423     }
1424     acb->bs = bs;
1425     acb->cb = cb;
1426     acb->opaque = opaque;
1427     return acb;
1428 }
1429
1430 void qemu_aio_release(void *p)
1431 {
1432     BlockDriverAIOCB *acb = p;
1433     BlockDriver *drv = acb->bs->drv;
1434     acb->next = drv->free_aiocb;
1435     drv->free_aiocb = acb;
1436 }
1437
1438 /**************************************************************/
1439 /* removable device support */
1440
1441 /**
1442  * Return TRUE if the media is present
1443  */
1444 int bdrv_is_inserted(BlockDriverState *bs)
1445 {
1446     BlockDriver *drv = bs->drv;
1447     int ret;
1448     if (!drv)
1449         return 0;
1450     if (!drv->bdrv_is_inserted)
1451         return 1;
1452     ret = drv->bdrv_is_inserted(bs);
1453     return ret;
1454 }
1455
1456 /**
1457  * Return TRUE if the media changed since the last call to this
1458  * function. It is currently only used for floppy disks
1459  */
1460 int bdrv_media_changed(BlockDriverState *bs)
1461 {
1462     BlockDriver *drv = bs->drv;
1463     int ret;
1464
1465     if (!drv || !drv->bdrv_media_changed)
1466         ret = -ENOTSUP;
1467     else
1468         ret = drv->bdrv_media_changed(bs);
1469     if (ret == -ENOTSUP)
1470         ret = bs->media_changed;
1471     bs->media_changed = 0;
1472     return ret;
1473 }
1474
1475 /**
1476  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1477  */
1478 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1479 {
1480     BlockDriver *drv = bs->drv;
1481     int ret;
1482
1483     if (!drv || !drv->bdrv_eject) {
1484         ret = -ENOTSUP;
1485     } else {
1486         ret = drv->bdrv_eject(bs, eject_flag);
1487     }
1488     if (ret == -ENOTSUP) {
1489         if (eject_flag)
1490             bdrv_close(bs);
1491     }
1492 }
1493
1494 int bdrv_is_locked(BlockDriverState *bs)
1495 {
1496     return bs->locked;
1497 }
1498
1499 /**
1500  * Lock or unlock the media (if it is locked, the user won't be able
1501  * to eject it manually).
1502  */
1503 void bdrv_set_locked(BlockDriverState *bs, int locked)
1504 {
1505     BlockDriver *drv = bs->drv;
1506
1507     bs->locked = locked;
1508     if (drv && drv->bdrv_set_locked) {
1509         drv->bdrv_set_locked(bs, locked);
1510     }
1511 }
1512
1513 /* needed for generic scsi interface */
1514
1515 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1516 {
1517     BlockDriver *drv = bs->drv;
1518
1519     if (drv && drv->bdrv_ioctl)
1520         return drv->bdrv_ioctl(bs, req, buf);
1521     return -ENOTSUP;
1522 }