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 #ifndef QEMU_IMG
  26 #include "console.h"
  27 #endif
  28 #include "block_int.h"
  29
  30 #ifdef _BSD
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/queue.h>
  35 #include <sys/disk.h>
  36 #endif
  37
  38 #define SECTOR_BITS 9
  39 #define SECTOR_SIZE (1 << SECTOR_BITS)
  40
  41 typedef struct BlockDriverAIOCBSync {
  42     BlockDriverAIOCB common;
  43     QEMUBH *bh;
  44     int ret;
  45 } BlockDriverAIOCBSync;
  46
  47 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
  48         int64_t sector_num, uint8_t *buf, int nb_sectors,
  49         BlockDriverCompletionFunc *cb, void *opaque);
  50 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
  51         int64_t sector_num, const uint8_t *buf, int nb_sectors,
  52         BlockDriverCompletionFunc *cb, void *opaque);
  53 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
  54 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
  55                         uint8_t *buf, int nb_sectors);
  56 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
  57                          const uint8_t *buf, int nb_sectors);
  58
  59 BlockDriverState *bdrv_first;
  60 static BlockDriver *first_drv;
  61
  62 int path_is_absolute(const char *path)
  63 {
  64     const char *p;
  65 #ifdef _WIN32
  66     /* specific case for names like: "\\.\d:" */
  67     if (*path == '/' || *path == '\\')
  68         return 1;
  69 #endif
  70     p = strchr(path, ':');
  71     if (p)
  72         p++;
  73     else
  74         p = path;
  75 #ifdef _WIN32
  76     return (*p == '/' || *p == '\\');
  77 #else
  78     return (*p == '/');
  79 #endif
  80 }
  81
  82 /* if filename is absolute, just copy it to dest. Otherwise, build a
  83    path to it by considering it is relative to base_path. URL are
  84    supported. */
  85 void path_combine(char *dest, int dest_size,
  86                   const char *base_path,
  87                   const char *filename)
  88 {
  89     const char *p, *p1;
  90     int len;
  91
  92     if (dest_size <= 0)
  93         return;
  94     if (path_is_absolute(filename)) {
  95         pstrcpy(dest, dest_size, filename);
  96     } else {
  97         p = strchr(base_path, ':');
  98         if (p)
  99             p++;
 100         else
 101             p = base_path;
 102         p1 = strrchr(base_path, '/');
 103 #ifdef _WIN32
 104         {
 105             const char *p2;
 106             p2 = strrchr(base_path, '\\');
 107             if (!p1 || p2 > p1)
 108                 p1 = p2;
 109         }
 110 #endif
 111         if (p1)
 112             p1++;
 113         else
 114             p1 = base_path;
 115         if (p1 > p)
 116             p = p1;
 117         len = p - base_path;
 118         if (len > dest_size - 1)
 119             len = dest_size - 1;
 120         memcpy(dest, base_path, len);
 121         dest[len] = '\0';
 122         pstrcat(dest, dest_size, filename);
 123     }
 124 }
 125
 126
 127 static void bdrv_register(BlockDriver *bdrv)
 128 {
 129     if (!bdrv->bdrv_aio_read) {
 130         /* add AIO emulation layer */
 131         bdrv->bdrv_aio_read = bdrv_aio_read_em;
 132         bdrv->bdrv_aio_write = bdrv_aio_write_em;
 133         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
 134         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
 135     } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
 136         /* add synchronous IO emulation layer */
 137         bdrv->bdrv_read = bdrv_read_em;
 138         bdrv->bdrv_write = bdrv_write_em;
 139     }
 140     bdrv->next = first_drv;
 141     first_drv = bdrv;
 142 }
 143
 144 /* create a new block device (by default it is empty) */
 145 BlockDriverState *bdrv_new(const char *device_name)
 146 {
 147     BlockDriverState **pbs, *bs;
 148
 149     bs = qemu_mallocz(sizeof(BlockDriverState));
 150     if(!bs)
 151         return NULL;
 152     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
 153     if (device_name[0] != '\0') {
 154         /* insert at the end */
 155         pbs = &bdrv_first;
 156         while (*pbs != NULL)
 157             pbs = &(*pbs)->next;
 158         *pbs = bs;
 159     }
 160     return bs;
 161 }
 162
 163 BlockDriver *bdrv_find_format(const char *format_name)
 164 {
 165     BlockDriver *drv1;
 166     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 167         if (!strcmp(drv1->format_name, format_name))
 168             return drv1;
 169     }
 170     return NULL;
 171 }
 172
 173 int bdrv_create(BlockDriver *drv,
 174                 const char *filename, int64_t size_in_sectors,
 175                 const char *backing_file, int flags)
 176 {
 177     if (!drv->bdrv_create)
 178         return -ENOTSUP;
 179     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
 180 }
 181
 182 #ifdef _WIN32
 183 void get_tmp_filename(char *filename, int size)
 184 {
 185     char temp_dir[MAX_PATH];
 186
 187     GetTempPath(MAX_PATH, temp_dir);
 188     GetTempFileName(temp_dir, "qem", 0, filename);
 189 }
 190 #else
 191 void get_tmp_filename(char *filename, int size)
 192 {
 193     int fd;
 194     /* XXX: race condition possible */
 195     pstrcpy(filename, size, "/tmp/vl.XXXXXX");
 196     fd = mkstemp(filename);
 197     close(fd);
 198 }
 199 #endif
 200
 201 #ifdef _WIN32
 202 static int is_windows_drive_prefix(const char *filename)
 203 {
 204     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
 205              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 206             filename[1] == ':');
 207 }
 208
 209 static int is_windows_drive(const char *filename)
 210 {
 211     if (is_windows_drive_prefix(filename) &&
 212         filename[2] == '\0')
 213         return 1;
 214     if (strstart(filename, "\\\\.\\", NULL) ||
 215         strstart(filename, "//./", NULL))
 216         return 1;
 217     return 0;
 218 }
 219 #endif
 220
 221 static BlockDriver *find_protocol(const char *filename)
 222 {
 223     BlockDriver *drv1;
 224     char protocol[128];
 225     int len;
 226     const char *p;
 227
 228 #ifdef _WIN32
 229     if (is_windows_drive(filename) ||
 230         is_windows_drive_prefix(filename))
 231         return &bdrv_raw;
 232 #endif
 233     p = strchr(filename, ':');
 234     if (!p)
 235         return &bdrv_raw;
 236     len = p - filename;
 237     if (len > sizeof(protocol) - 1)
 238         len = sizeof(protocol) - 1;
 239     memcpy(protocol, filename, len);
 240     protocol[len] = '\0';
 241     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 242         if (drv1->protocol_name &&
 243             !strcmp(drv1->protocol_name, protocol))
 244             return drv1;
 245     }
 246     return NULL;
 247 }
 248
 249 /* XXX: force raw format if block or character device ? It would
 250    simplify the BSD case */
 251 static BlockDriver *find_image_format(const char *filename)
 252 {
 253     int ret, score, score_max;
 254     BlockDriver *drv1, *drv;
 255     uint8_t buf[2048];
 256     BlockDriverState *bs;
 257
 258     /* detect host devices. By convention, /dev/cdrom[N] is always
 259        recognized as a host CDROM */
 260     if (strstart(filename, "/dev/cdrom", NULL))
 261         return &bdrv_host_device;
 262 #ifdef _WIN32
 263     if (is_windows_drive(filename))
 264         return &bdrv_host_device;
 265 #else
 266     {
 267         struct stat st;
 268         if (stat(filename, &st) >= 0 &&
 269             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
 270             return &bdrv_host_device;
 271         }
 272     }
 273 #endif
 274
 275     drv = find_protocol(filename);
 276     /* no need to test disk image formats for vvfat */
 277     if (drv == &bdrv_vvfat)
 278         return drv;
 279
 280     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
 281     if (ret < 0)
 282         return NULL;
 283     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
 284     bdrv_delete(bs);
 285     if (ret < 0) {
 286         return NULL;
 287     }
 288
 289     score_max = 0;
 290     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 291         if (drv1->bdrv_probe) {
 292             score = drv1->bdrv_probe(buf, ret, filename);
 293             if (score > score_max) {
 294                 score_max = score;
 295                 drv = drv1;
 296             }
 297         }
 298     }
 299     return drv;
 300 }
 301
 302 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 303 {
 304     BlockDriverState *bs;
 305     int ret;
 306
 307     bs = bdrv_new("");
 308     if (!bs)
 309         return -ENOMEM;
 310     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
 311     if (ret < 0) {
 312         bdrv_delete(bs);
 313         return ret;
 314     }
 315     *pbs = bs;
 316     return 0;
 317 }
 318
 319 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
 320 {
 321     return bdrv_open2(bs, filename, flags, NULL);
 322 }
 323
 324 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 325                BlockDriver *drv)
 326 {
 327     int ret, open_flags;
 328     char tmp_filename[PATH_MAX];
 329     char backing_filename[PATH_MAX];
 330
 331     bs->read_only = 0;
 332     bs->is_temporary = 0;
 333     bs->encrypted = 0;
 334
 335     if (flags & BDRV_O_SNAPSHOT) {
 336         BlockDriverState *bs1;
 337         int64_t total_size;
 338
 339         /* if snapshot, we create a temporary backing file and open it
 340            instead of opening 'filename' directly */
 341
 342         /* if there is a backing file, use it */
 343         bs1 = bdrv_new("");
 344         if (!bs1) {
 345             return -ENOMEM;
 346         }
 347         if (bdrv_open(bs1, filename, 0) < 0) {
 348             bdrv_delete(bs1);
 349             return -1;
 350         }
 351         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
 352         bdrv_delete(bs1);
 353
 354         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 355         realpath(filename, backing_filename);
 356         if (bdrv_create(&bdrv_qcow2, tmp_filename,
 357                         total_size, backing_filename, 0) < 0) {
 358             return -1;
 359         }
 360         filename = tmp_filename;
 361         bs->is_temporary = 1;
 362     }
 363
 364     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 365     if (flags & BDRV_O_FILE) {
 366         drv = find_protocol(filename);
 367         if (!drv)
 368             return -ENOENT;
 369     } else {
 370         if (!drv) {
 371             drv = find_image_format(filename);
 372             if (!drv)
 373                 return -1;
 374         }
 375     }
 376     bs->drv = drv;
 377     bs->opaque = qemu_mallocz(drv->instance_size);
 378     if (bs->opaque == NULL && drv->instance_size > 0)
 379         return -1;
 380     /* Note: for compatibility, we open disk image files as RDWR, and
 381        RDONLY as fallback */
 382     if (!(flags & BDRV_O_FILE))
 383         open_flags = BDRV_O_RDWR;
 384     else
 385         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
 386     ret = drv->bdrv_open(bs, filename, open_flags);
 387     if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
 388         ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
 389         bs->read_only = 1;
 390     }
 391     if (ret < 0) {
 392         qemu_free(bs->opaque);
 393         bs->opaque = NULL;
 394         bs->drv = NULL;
 395         return ret;
 396     }
 397     if (drv->bdrv_getlength) {
 398         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 399     }
 400 #ifndef _WIN32
 401     if (bs->is_temporary) {
 402         unlink(filename);
 403     }
 404 #endif
 405     if (bs->backing_file[0] != '\0') {
 406         /* if there is a backing file, use it */
 407         bs->backing_hd = bdrv_new("");
 408         if (!bs->backing_hd) {
 409         fail:
 410             bdrv_close(bs);
 411             return -ENOMEM;
 412         }
 413         path_combine(backing_filename, sizeof(backing_filename),
 414                      filename, bs->backing_file);
 415         if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
 416             goto fail;
 417     }
 418
 419     /* call the change callback */
 420     bs->media_changed = 1;
 421     if (bs->change_cb)
 422         bs->change_cb(bs->change_opaque);
 423
 424     return 0;
 425 }
 426
 427 void bdrv_close(BlockDriverState *bs)
 428 {
 429     if (bs->drv) {
 430         if (bs->backing_hd)
 431             bdrv_delete(bs->backing_hd);
 432         bs->drv->bdrv_close(bs);
 433         qemu_free(bs->opaque);
 434 #ifdef _WIN32
 435         if (bs->is_temporary) {
 436             unlink(bs->filename);
 437         }
 438 #endif
 439         bs->opaque = NULL;
 440         bs->drv = NULL;
 441
 442         /* call the change callback */
 443         bs->media_changed = 1;
 444         if (bs->change_cb)
 445             bs->change_cb(bs->change_opaque);
 446     }
 447 }
 448
 449 void bdrv_delete(BlockDriverState *bs)
 450 {
 451     /* XXX: remove the driver list */
 452     bdrv_close(bs);
 453     qemu_free(bs);
 454 }
 455
 456 /* commit COW file into the raw image */
 457 int bdrv_commit(BlockDriverState *bs)
 458 {
 459     BlockDriver *drv = bs->drv;
 460     int64_t i, total_sectors;
 461     int n, j;
 462     unsigned char sector[512];
 463
 464     if (!drv)
 465         return -ENOMEDIUM;
 466
 467     if (bs->read_only) {
 468         return -EACCES;
 469     }
 470
 471     if (!bs->backing_hd) {
 472         return -ENOTSUP;
 473     }
 474
 475     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 476     for (i = 0; i < total_sectors;) {
 477         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 478             for(j = 0; j < n; j++) {
 479                 if (bdrv_read(bs, i, sector, 1) != 0) {
 480                     return -EIO;
 481                 }
 482
 483                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 484                     return -EIO;
 485                 }
 486                 i++;
 487             }
 488         } else {
 489             i += n;
 490         }
 491     }
 492
 493     if (drv->bdrv_make_empty)
 494         return drv->bdrv_make_empty(bs);
 495
 496     return 0;
 497 }
 498
 499 /* return < 0 if error. See bdrv_write() for the return codes */
 500 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 501               uint8_t *buf, int nb_sectors)
 502 {
 503     BlockDriver *drv = bs->drv;
 504
 505     if (!drv)
 506         return -ENOMEDIUM;
 507
 508     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 509             memcpy(buf, bs->boot_sector_data, 512);
 510         sector_num++;
 511         nb_sectors--;
 512         buf += 512;
 513         if (nb_sectors == 0)
 514             return 0;
 515     }
 516     if (drv->bdrv_pread) {
 517         int ret, len;
 518         len = nb_sectors * 512;
 519         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 520         if (ret < 0)
 521             return ret;
 522         else if (ret != len)
 523             return -EINVAL;
 524         else {
 525             bs->rd_bytes += (unsigned) len;
 526             bs->rd_ops ++;
 527             return 0;
 528         }
 529     } else {
 530         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 531     }
 532 }
 533
 534 /* Return < 0 if error. Important errors are:
 535   -EIO         generic I/O error (may happen for all errors)
 536   -ENOMEDIUM   No media inserted.
 537   -EINVAL      Invalid sector number or nb_sectors
 538   -EACCES      Trying to write a read-only device
 539 */
 540 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 541                const uint8_t *buf, int nb_sectors)
 542 {
 543     BlockDriver *drv = bs->drv;
 544     if (!bs->drv)
 545         return -ENOMEDIUM;
 546     if (bs->read_only)
 547         return -EACCES;
 548     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 549         memcpy(bs->boot_sector_data, buf, 512);
 550     }
 551     if (drv->bdrv_pwrite) {
 552         int ret, len;
 553         len = nb_sectors * 512;
 554         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 555         if (ret < 0)
 556             return ret;
 557         else if (ret != len)
 558             return -EIO;
 559         else {
 560             bs->wr_bytes += (unsigned) len;
 561             bs->wr_ops ++;
 562             return 0;
 563         }
 564     } else {
 565         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 566     }
 567 }
 568
 569 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 570                          uint8_t *buf, int count1)
 571 {
 572     uint8_t tmp_buf[SECTOR_SIZE];
 573     int len, nb_sectors, count;
 574     int64_t sector_num;
 575
 576     count = count1;
 577     /* first read to align to sector start */
 578     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 579     if (len > count)
 580         len = count;
 581     sector_num = offset >> SECTOR_BITS;
 582     if (len > 0) {
 583         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 584             return -EIO;
 585         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 586         count -= len;
 587         if (count == 0)
 588             return count1;
 589         sector_num++;
 590         buf += len;
 591     }
 592
 593     /* read the sectors "in place" */
 594     nb_sectors = count >> SECTOR_BITS;
 595     if (nb_sectors > 0) {
 596         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 597             return -EIO;
 598         sector_num += nb_sectors;
 599         len = nb_sectors << SECTOR_BITS;
 600         buf += len;
 601         count -= len;
 602     }
 603
 604     /* add data from the last sector */
 605     if (count > 0) {
 606         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 607             return -EIO;
 608         memcpy(buf, tmp_buf, count);
 609     }
 610     return count1;
 611 }
 612
 613 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 614                           const uint8_t *buf, int count1)
 615 {
 616     uint8_t tmp_buf[SECTOR_SIZE];
 617     int len, nb_sectors, count;
 618     int64_t sector_num;
 619
 620     count = count1;
 621     /* first write to align to sector start */
 622     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 623     if (len > count)
 624         len = count;
 625     sector_num = offset >> SECTOR_BITS;
 626     if (len > 0) {
 627         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 628             return -EIO;
 629         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 630         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 631             return -EIO;
 632         count -= len;
 633         if (count == 0)
 634             return count1;
 635         sector_num++;
 636         buf += len;
 637     }
 638
 639     /* write the sectors "in place" */
 640     nb_sectors = count >> SECTOR_BITS;
 641     if (nb_sectors > 0) {
 642         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 643             return -EIO;
 644         sector_num += nb_sectors;
 645         len = nb_sectors << SECTOR_BITS;
 646         buf += len;
 647         count -= len;
 648     }
 649
 650     /* add data from the last sector */
 651     if (count > 0) {
 652         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 653             return -EIO;
 654         memcpy(tmp_buf, buf, count);
 655         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 656             return -EIO;
 657     }
 658     return count1;
 659 }
 660
 661 /**
 662  * Read with byte offsets (needed only for file protocols)
 663  */
 664 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 665                void *buf1, int count1)
 666 {
 667     BlockDriver *drv = bs->drv;
 668
 669     if (!drv)
 670         return -ENOMEDIUM;
 671     if (!drv->bdrv_pread)
 672         return bdrv_pread_em(bs, offset, buf1, count1);
 673     return drv->bdrv_pread(bs, offset, buf1, count1);
 674 }
 675
 676 /**
 677  * Write with byte offsets (needed only for file protocols)
 678  */
 679 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 680                 const void *buf1, int count1)
 681 {
 682     BlockDriver *drv = bs->drv;
 683
 684     if (!drv)
 685         return -ENOMEDIUM;
 686     if (!drv->bdrv_pwrite)
 687         return bdrv_pwrite_em(bs, offset, buf1, count1);
 688     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 689 }
 690
 691 /**
 692  * Truncate file to 'offset' bytes (needed only for file protocols)
 693  */
 694 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 695 {
 696     BlockDriver *drv = bs->drv;
 697     if (!drv)
 698         return -ENOMEDIUM;
 699     if (!drv->bdrv_truncate)
 700         return -ENOTSUP;
 701     return drv->bdrv_truncate(bs, offset);
 702 }
 703
 704 /**
 705  * Length of a file in bytes. Return < 0 if error or unknown.
 706  */
 707 int64_t bdrv_getlength(BlockDriverState *bs)
 708 {
 709     BlockDriver *drv = bs->drv;
 710     if (!drv)
 711         return -ENOMEDIUM;
 712     if (!drv->bdrv_getlength) {
 713         /* legacy mode */
 714         return bs->total_sectors * SECTOR_SIZE;
 715     }
 716     return drv->bdrv_getlength(bs);
 717 }
 718
 719 /* return 0 as number of sectors if no device present or error */
 720 void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
 721 {
 722     int64_t length;
 723     length = bdrv_getlength(bs);
 724     if (length < 0)
 725         length = 0;
 726     else
 727         length = length >> SECTOR_BITS;
 728     *nb_sectors_ptr = length;
 729 }
 730
 731 /* force a given boot sector. */
 732 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 733 {
 734     bs->boot_sector_enabled = 1;
 735     if (size > 512)
 736         size = 512;
 737     memcpy(bs->boot_sector_data, data, size);
 738     memset(bs->boot_sector_data + size, 0, 512 - size);
 739 }
 740
 741 struct partition {
 742         uint8_t boot_ind;               /* 0x80 - active */
 743         uint8_t head;           /* starting head */
 744         uint8_t sector;         /* starting sector */
 745         uint8_t cyl;            /* starting cylinder */
 746         uint8_t sys_ind;                /* What partition type */
 747         uint8_t end_head;               /* end head */
 748         uint8_t end_sector;     /* end sector */
 749         uint8_t end_cyl;                /* end cylinder */
 750         uint32_t start_sect;    /* starting sector counting from 0 */
 751         uint32_t nr_sects;              /* nr of sectors in partition */
 752 } __attribute__((packed));
 753
 754 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
 755 static int guess_disk_lchs(BlockDriverState *bs,
 756                            int *pcylinders, int *pheads, int *psectors)
 757 {
 758     uint8_t buf[512];
 759     int ret, i, heads, sectors, cylinders;
 760     struct partition *p;
 761     uint32_t nr_sects;
 762     int64_t nb_sectors;
 763
 764     bdrv_get_geometry(bs, &nb_sectors);
 765
 766     ret = bdrv_read(bs, 0, buf, 1);
 767     if (ret < 0)
 768         return -1;
 769     /* test msdos magic */
 770     if (buf[510] != 0x55 || buf[511] != 0xaa)
 771         return -1;
 772     for(i = 0; i < 4; i++) {
 773         p = ((struct partition *)(buf + 0x1be)) + i;
 774         nr_sects = le32_to_cpu(p->nr_sects);
 775         if (nr_sects && p->end_head) {
 776             /* We make the assumption that the partition terminates on
 777                a cylinder boundary */
 778             heads = p->end_head + 1;
 779             sectors = p->end_sector & 63;
 780             if (sectors == 0)
 781                 continue;
 782             cylinders = nb_sectors / (heads * sectors);
 783             if (cylinders < 1 || cylinders > 16383)
 784                 continue;
 785             *pheads = heads;
 786             *psectors = sectors;
 787             *pcylinders = cylinders;
 788 #if 0
 789             printf("guessed geometry: LCHS=%d %d %d\n",
 790                    cylinders, heads, sectors);
 791 #endif
 792             return 0;
 793         }
 794     }
 795     return -1;
 796 }
 797
 798 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
 799 {
 800     int translation, lba_detected = 0;
 801     int cylinders, heads, secs;
 802     int64_t nb_sectors;
 803
 804     /* if a geometry hint is available, use it */
 805     bdrv_get_geometry(bs, &nb_sectors);
 806     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
 807     translation = bdrv_get_translation_hint(bs);
 808     if (cylinders != 0) {
 809         *pcyls = cylinders;
 810         *pheads = heads;
 811         *psecs = secs;
 812     } else {
 813         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
 814             if (heads > 16) {
 815                 /* if heads > 16, it means that a BIOS LBA
 816                    translation was active, so the default
 817                    hardware geometry is OK */
 818                 lba_detected = 1;
 819                 goto default_geometry;
 820             } else {
 821                 *pcyls = cylinders;
 822                 *pheads = heads;
 823                 *psecs = secs;
 824                 /* disable any translation to be in sync with
 825                    the logical geometry */
 826                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
 827                     bdrv_set_translation_hint(bs,
 828                                               BIOS_ATA_TRANSLATION_NONE);
 829                 }
 830             }
 831         } else {
 832         default_geometry:
 833             /* if no geometry, use a standard physical disk geometry */
 834             cylinders = nb_sectors / (16 * 63);
 835
 836             if (cylinders > 16383)
 837                 cylinders = 16383;
 838             else if (cylinders < 2)
 839                 cylinders = 2;
 840             *pcyls = cylinders;
 841             *pheads = 16;
 842             *psecs = 63;
 843             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
 844                 if ((*pcyls * *pheads) <= 131072) {
 845                     bdrv_set_translation_hint(bs,
 846                                               BIOS_ATA_TRANSLATION_LARGE);
 847                 } else {
 848                     bdrv_set_translation_hint(bs,
 849                                               BIOS_ATA_TRANSLATION_LBA);
 850                 }
 851             }
 852         }
 853         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
 854     }
 855 }
 856
 857 void bdrv_set_geometry_hint(BlockDriverState *bs,
 858                             int cyls, int heads, int secs)
 859 {
 860     bs->cyls = cyls;
 861     bs->heads = heads;
 862     bs->secs = secs;
 863 }
 864
 865 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 866 {
 867     bs->type = type;
 868     bs->removable = ((type == BDRV_TYPE_CDROM ||
 869                       type == BDRV_TYPE_FLOPPY));
 870 }
 871
 872 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 873 {
 874     bs->translation = translation;
 875 }
 876
 877 void bdrv_get_geometry_hint(BlockDriverState *bs,
 878                             int *pcyls, int *pheads, int *psecs)
 879 {
 880     *pcyls = bs->cyls;
 881     *pheads = bs->heads;
 882     *psecs = bs->secs;
 883 }
 884
 885 int bdrv_get_type_hint(BlockDriverState *bs)
 886 {
 887     return bs->type;
 888 }
 889
 890 int bdrv_get_translation_hint(BlockDriverState *bs)
 891 {
 892     return bs->translation;
 893 }
 894
 895 int bdrv_is_removable(BlockDriverState *bs)
 896 {
 897     return bs->removable;
 898 }
 899
 900 int bdrv_is_read_only(BlockDriverState *bs)
 901 {
 902     return bs->read_only;
 903 }
 904
 905 /* XXX: no longer used */
 906 void bdrv_set_change_cb(BlockDriverState *bs,
 907                         void (*change_cb)(void *opaque), void *opaque)
 908 {
 909     bs->change_cb = change_cb;
 910     bs->change_opaque = opaque;
 911 }
 912
 913 int bdrv_is_encrypted(BlockDriverState *bs)
 914 {
 915     if (bs->backing_hd && bs->backing_hd->encrypted)
 916         return 1;
 917     return bs->encrypted;
 918 }
 919
 920 int bdrv_set_key(BlockDriverState *bs, const char *key)
 921 {
 922     int ret;
 923     if (bs->backing_hd && bs->backing_hd->encrypted) {
 924         ret = bdrv_set_key(bs->backing_hd, key);
 925         if (ret < 0)
 926             return ret;
 927         if (!bs->encrypted)
 928             return 0;
 929     }
 930     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 931         return -1;
 932     return bs->drv->bdrv_set_key(bs, key);
 933 }
 934
 935 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 936 {
 937     if (!bs->drv) {
 938         buf[0] = '\0';
 939     } else {
 940         pstrcpy(buf, buf_size, bs->drv->format_name);
 941     }
 942 }
 943
 944 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 945                          void *opaque)
 946 {
 947     BlockDriver *drv;
 948
 949     for (drv = first_drv; drv != NULL; drv = drv->next) {
 950         it(opaque, drv->format_name);
 951     }
 952 }
 953
 954 BlockDriverState *bdrv_find(const char *name)
 955 {
 956     BlockDriverState *bs;
 957
 958     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 959         if (!strcmp(name, bs->device_name))
 960             return bs;
 961     }
 962     return NULL;
 963 }
 964
 965 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 966 {
 967     BlockDriverState *bs;
 968
 969     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 970         it(opaque, bs->device_name);
 971     }
 972 }
 973
 974 const char *bdrv_get_device_name(BlockDriverState *bs)
 975 {
 976     return bs->device_name;
 977 }
 978
 979 void bdrv_flush(BlockDriverState *bs)
 980 {
 981     if (bs->drv->bdrv_flush)
 982         bs->drv->bdrv_flush(bs);
 983     if (bs->backing_hd)
 984         bdrv_flush(bs->backing_hd);
 985 }
 986
 987 void bdrv_iterate_writeable(void (*it)(BlockDriverState *bs))
 988 {
 989     BlockDriverState *bs;
 990
 991     for (bs = bdrv_first; bs != NULL; bs = bs->next)
 992         if (bs->drv && !bdrv_is_read_only(bs) &&
 993             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
 994             it(bs);
 995 }
 996
 997 void bdrv_flush_all(void)
 998 {
 999     bdrv_iterate_writeable(bdrv_flush);
1000 }
1001
1002 #ifndef QEMU_IMG
1003 void bdrv_info(void)
1004 {
1005     BlockDriverState *bs;
1006
1007     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1008         term_printf("%s:", bs->device_name);
1009         term_printf(" type=");
1010         switch(bs->type) {
1011         case BDRV_TYPE_HD:
1012             term_printf("hd");
1013             break;
1014         case BDRV_TYPE_CDROM:
1015             term_printf("cdrom");
1016             break;
1017         case BDRV_TYPE_FLOPPY:
1018             term_printf("floppy");
1019             break;
1020         }
1021         term_printf(" removable=%d", bs->removable);
1022         if (bs->removable) {
1023             term_printf(" locked=%d", bs->locked);
1024         }
1025         if (bs->drv) {
1026             term_printf(" file=");
1027             term_print_filename(bs->filename);
1028             if (bs->backing_file[0] != '\0') {
1029                 term_printf(" backing_file=");
1030                 term_print_filename(bs->backing_file);
1031             }
1032             term_printf(" ro=%d", bs->read_only);
1033             term_printf(" drv=%s", bs->drv->format_name);
1034             if (bs->encrypted)
1035                 term_printf(" encrypted");
1036         } else {
1037             term_printf(" [not inserted]");
1038         }
1039         term_printf("\n");
1040     }
1041 }
1042
1043 /* The "info blockstats" command. */
1044 void bdrv_info_stats (void)
1045 {
1046     BlockDriverState *bs;
1047
1048     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1049         term_printf ("%s:"
1050                      " rd_bytes=%" PRIu64
1051                      " wr_bytes=%" PRIu64
1052                      " rd_operations=%" PRIu64
1053                      " wr_operations=%" PRIu64
1054                      "\n",
1055                      bs->device_name,
1056                      bs->rd_bytes, bs->wr_bytes,
1057                      bs->rd_ops, bs->wr_ops);
1058     }
1059 }
1060 #endif
1061
1062 void bdrv_get_backing_filename(BlockDriverState *bs,
1063                                char *filename, int filename_size)
1064 {
1065     if (!bs->backing_hd) {
1066         pstrcpy(filename, filename_size, "");
1067     } else {
1068         pstrcpy(filename, filename_size, bs->backing_file);
1069     }
1070 }
1071
1072 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1073                           const uint8_t *buf, int nb_sectors)
1074 {
1075     BlockDriver *drv = bs->drv;
1076     if (!drv)
1077         return -ENOMEDIUM;
1078     if (!drv->bdrv_write_compressed)
1079         return -ENOTSUP;
1080     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1081 }
1082
1083 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1084 {
1085     BlockDriver *drv = bs->drv;
1086     if (!drv)
1087         return -ENOMEDIUM;
1088     if (!drv->bdrv_get_info)
1089         return -ENOTSUP;
1090     memset(bdi, 0, sizeof(*bdi));
1091     return drv->bdrv_get_info(bs, bdi);
1092 }
1093
1094 /**************************************************************/
1095 /* handling of snapshots */
1096
1097 int bdrv_snapshot_create(BlockDriverState *bs,
1098                          QEMUSnapshotInfo *sn_info)
1099 {
1100     BlockDriver *drv = bs->drv;
1101     if (!drv)
1102         return -ENOMEDIUM;
1103     if (!drv->bdrv_snapshot_create)
1104         return -ENOTSUP;
1105     return drv->bdrv_snapshot_create(bs, sn_info);
1106 }
1107
1108 int bdrv_snapshot_goto(BlockDriverState *bs,
1109                        const char *snapshot_id)
1110 {
1111     BlockDriver *drv = bs->drv;
1112     if (!drv)
1113         return -ENOMEDIUM;
1114     if (!drv->bdrv_snapshot_goto)
1115         return -ENOTSUP;
1116     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1117 }
1118
1119 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1120 {
1121     BlockDriver *drv = bs->drv;
1122     if (!drv)
1123         return -ENOMEDIUM;
1124     if (!drv->bdrv_snapshot_delete)
1125         return -ENOTSUP;
1126     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1127 }
1128
1129 int bdrv_snapshot_list(BlockDriverState *bs,
1130                        QEMUSnapshotInfo **psn_info)
1131 {
1132     BlockDriver *drv = bs->drv;
1133     if (!drv)
1134         return -ENOMEDIUM;
1135     if (!drv->bdrv_snapshot_list)
1136         return -ENOTSUP;
1137     return drv->bdrv_snapshot_list(bs, psn_info);
1138 }
1139
1140 #define NB_SUFFIXES 4
1141
1142 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1143 {
1144     static const char suffixes[NB_SUFFIXES] = "KMGT";
1145     int64_t base;
1146     int i;
1147
1148     if (size <= 999) {
1149         snprintf(buf, buf_size, "%" PRId64, size);
1150     } else {
1151         base = 1024;
1152         for(i = 0; i < NB_SUFFIXES; i++) {
1153             if (size < (10 * base)) {
1154                 snprintf(buf, buf_size, "%0.1f%c",
1155                          (double)size / base,
1156                          suffixes[i]);
1157                 break;
1158             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1159                 snprintf(buf, buf_size, "%" PRId64 "%c",
1160                          ((size + (base >> 1)) / base),
1161                          suffixes[i]);
1162                 break;
1163             }
1164             base = base * 1024;
1165         }
1166     }
1167     return buf;
1168 }
1169
1170 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1171 {
1172     char buf1[128], date_buf[128], clock_buf[128];
1173 #ifdef _WIN32
1174     struct tm *ptm;
1175 #else
1176     struct tm tm;
1177 #endif
1178     time_t ti;
1179     int64_t secs;
1180
1181     if (!sn) {
1182         snprintf(buf, buf_size,
1183                  "%-10s%-20s%7s%20s%15s",
1184                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1185     } else {
1186         ti = sn->date_sec;
1187 #ifdef _WIN32
1188         ptm = localtime(&ti);
1189         strftime(date_buf, sizeof(date_buf),
1190                  "%Y-%m-%d %H:%M:%S", ptm);
1191 #else
1192         localtime_r(&ti, &tm);
1193         strftime(date_buf, sizeof(date_buf),
1194                  "%Y-%m-%d %H:%M:%S", &tm);
1195 #endif
1196         secs = sn->vm_clock_nsec / 1000000000;
1197         snprintf(clock_buf, sizeof(clock_buf),
1198                  "%02d:%02d:%02d.%03d",
1199                  (int)(secs / 3600),
1200                  (int)((secs / 60) % 60),
1201                  (int)(secs % 60),
1202                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1203         snprintf(buf, buf_size,
1204                  "%-10s%-20s%7s%20s%15s",
1205                  sn->id_str, sn->name,
1206                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1207                  date_buf,
1208                  clock_buf);
1209     }
1210     return buf;
1211 }
1212
1213
1214 /**************************************************************/
1215 /* async I/Os */
1216
1217 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1218                                 uint8_t *buf, int nb_sectors,
1219                                 BlockDriverCompletionFunc *cb, void *opaque)
1220 {
1221     BlockDriver *drv = bs->drv;
1222     BlockDriverAIOCB *ret;
1223
1224     if (!drv)
1225         return NULL;
1226
1227     /* XXX: we assume that nb_sectors == 0 is suppored by the async read */
1228     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1229         memcpy(buf, bs->boot_sector_data, 512);
1230         sector_num++;
1231         nb_sectors--;
1232         buf += 512;
1233     }
1234
1235     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1236
1237     if (ret) {
1238         /* Update stats even though technically transfer has not happened. */
1239         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1240         bs->rd_ops ++;
1241     }
1242
1243     return ret;
1244 }
1245
1246 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1247                                  const uint8_t *buf, int nb_sectors,
1248                                  BlockDriverCompletionFunc *cb, void *opaque)
1249 {
1250     BlockDriver *drv = bs->drv;
1251     BlockDriverAIOCB *ret;
1252
1253     if (!drv)
1254         return NULL;
1255     if (bs->read_only)
1256         return NULL;
1257     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1258         memcpy(bs->boot_sector_data, buf, 512);
1259     }
1260
1261     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1262
1263     if (ret) {
1264         /* Update stats even though technically transfer has not happened. */
1265         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1266         bs->wr_ops ++;
1267     }
1268
1269     return ret;
1270 }
1271
1272 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1273 {
1274     BlockDriver *drv = acb->bs->drv;
1275
1276     drv->bdrv_aio_cancel(acb);
1277 }
1278
1279
1280 /**************************************************************/
1281 /* async block device emulation */
1282
1283 #ifdef QEMU_IMG
1284 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1285         int64_t sector_num, uint8_t *buf, int nb_sectors,
1286         BlockDriverCompletionFunc *cb, void *opaque)
1287 {
1288     int ret;
1289     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1290     cb(opaque, ret);
1291     return NULL;
1292 }
1293
1294 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1295         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1296         BlockDriverCompletionFunc *cb, void *opaque)
1297 {
1298     int ret;
1299     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1300     cb(opaque, ret);
1301     return NULL;
1302 }
1303
1304 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb)
1305 {
1306 }
1307 #else
1308 static void bdrv_aio_bh_cb(void *opaque)
1309 {
1310     BlockDriverAIOCBSync *acb = opaque;
1311     acb->common.cb(acb->common.opaque, acb->ret);
1312     qemu_aio_release(acb);
1313 }
1314
1315 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1316         int64_t sector_num, uint8_t *buf, int nb_sectors,
1317         BlockDriverCompletionFunc *cb, void *opaque)
1318 {
1319     BlockDriverAIOCBSync *acb;
1320     int ret;
1321
1322     acb = qemu_aio_get(bs, cb, opaque);
1323     if (!acb->bh)
1324         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1325     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1326     acb->ret = ret;
1327     qemu_bh_schedule(acb->bh);
1328     return &acb->common;
1329 }
1330
1331 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1332         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1333         BlockDriverCompletionFunc *cb, void *opaque)
1334 {
1335     BlockDriverAIOCBSync *acb;
1336     int ret;
1337
1338     acb = qemu_aio_get(bs, cb, opaque);
1339     if (!acb->bh)
1340         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1341     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1342     acb->ret = ret;
1343     qemu_bh_schedule(acb->bh);
1344     return &acb->common;
1345 }
1346
1347 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1348 {
1349     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1350     qemu_bh_cancel(acb->bh);
1351     qemu_aio_release(acb);
1352 }
1353 #endif /* !QEMU_IMG */
1354
1355 /**************************************************************/
1356 /* sync block device emulation */
1357
1358 static void bdrv_rw_em_cb(void *opaque, int ret)
1359 {
1360     *(int *)opaque = ret;
1361 }
1362
1363 #define NOT_DONE 0x7fffffff
1364
1365 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1366                         uint8_t *buf, int nb_sectors)
1367 {
1368     int async_ret;
1369     BlockDriverAIOCB *acb;
1370
1371     async_ret = NOT_DONE;
1372     qemu_aio_wait_start();
1373     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1374                         bdrv_rw_em_cb, &async_ret);
1375     if (acb == NULL) {
1376         qemu_aio_wait_end();
1377         return -1;
1378     }
1379     while (async_ret == NOT_DONE) {
1380         qemu_aio_wait();
1381     }
1382     qemu_aio_wait_end();
1383     return async_ret;
1384 }
1385
1386 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1387                          const uint8_t *buf, int nb_sectors)
1388 {
1389     int async_ret;
1390     BlockDriverAIOCB *acb;
1391
1392     async_ret = NOT_DONE;
1393     qemu_aio_wait_start();
1394     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1395                          bdrv_rw_em_cb, &async_ret);
1396     if (acb == NULL) {
1397         qemu_aio_wait_end();
1398         return -1;
1399     }
1400     while (async_ret == NOT_DONE) {
1401         qemu_aio_wait();
1402     }
1403     qemu_aio_wait_end();
1404     return async_ret;
1405 }
1406
1407 void bdrv_init(void)
1408 {
1409     bdrv_register(&bdrv_raw);
1410     bdrv_register(&bdrv_host_device);
1411 #ifndef _WIN32
1412     bdrv_register(&bdrv_cow);
1413 #endif
1414     bdrv_register(&bdrv_qcow);
1415     bdrv_register(&bdrv_vmdk);
1416     bdrv_register(&bdrv_cloop);
1417     bdrv_register(&bdrv_dmg);
1418     bdrv_register(&bdrv_bochs);
1419     bdrv_register(&bdrv_vpc);
1420     bdrv_register(&bdrv_vvfat);
1421     bdrv_register(&bdrv_qcow2);
1422     bdrv_register(&bdrv_parallels);
1423 }
1424
1425 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1426                    void *opaque)
1427 {
1428     BlockDriver *drv;
1429     BlockDriverAIOCB *acb;
1430
1431     drv = bs->drv;
1432     if (drv->free_aiocb) {
1433         acb = drv->free_aiocb;
1434         drv->free_aiocb = acb->next;
1435     } else {
1436         acb = qemu_mallocz(drv->aiocb_size);
1437         if (!acb)
1438             return NULL;
1439     }
1440     acb->bs = bs;
1441     acb->cb = cb;
1442     acb->opaque = opaque;
1443     return acb;
1444 }
1445
1446 void qemu_aio_release(void *p)
1447 {
1448     BlockDriverAIOCB *acb = p;
1449     BlockDriver *drv = acb->bs->drv;
1450     acb->next = drv->free_aiocb;
1451     drv->free_aiocb = acb;
1452 }
1453
1454 /**************************************************************/
1455 /* removable device support */
1456
1457 /**
1458  * Return TRUE if the media is present
1459  */
1460 int bdrv_is_inserted(BlockDriverState *bs)
1461 {
1462     BlockDriver *drv = bs->drv;
1463     int ret;
1464     if (!drv)
1465         return 0;
1466     if (!drv->bdrv_is_inserted)
1467         return 1;
1468     ret = drv->bdrv_is_inserted(bs);
1469     return ret;
1470 }
1471
1472 /**
1473  * Return TRUE if the media changed since the last call to this
1474  * function. It is currently only used for floppy disks
1475  */
1476 int bdrv_media_changed(BlockDriverState *bs)
1477 {
1478     BlockDriver *drv = bs->drv;
1479     int ret;
1480
1481     if (!drv || !drv->bdrv_media_changed)
1482         ret = -ENOTSUP;
1483     else
1484         ret = drv->bdrv_media_changed(bs);
1485     if (ret == -ENOTSUP)
1486         ret = bs->media_changed;
1487     bs->media_changed = 0;
1488     return ret;
1489 }
1490
1491 /**
1492  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1493  */
1494 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1495 {
1496     BlockDriver *drv = bs->drv;
1497     int ret;
1498
1499     if (!drv || !drv->bdrv_eject) {
1500         ret = -ENOTSUP;
1501     } else {
1502         ret = drv->bdrv_eject(bs, eject_flag);
1503     }
1504     if (ret == -ENOTSUP) {
1505         if (eject_flag)
1506             bdrv_close(bs);
1507     }
1508 }
1509
1510 int bdrv_is_locked(BlockDriverState *bs)
1511 {
1512     return bs->locked;
1513 }
1514
1515 /**
1516  * Lock or unlock the media (if it is locked, the user won't be able
1517  * to eject it manually).
1518  */
1519 void bdrv_set_locked(BlockDriverState *bs, int locked)
1520 {
1521     BlockDriver *drv = bs->drv;
1522
1523     bs->locked = locked;
1524     if (drv && drv->bdrv_set_locked) {
1525         drv->bdrv_set_locked(bs, locked);
1526     }
1527 }