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 #include "osdep.h"
  28
  29 #ifdef _BSD
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/queue.h>
  34 #include <sys/disk.h>
  35 #endif
  36
  37 #define SECTOR_BITS 9
  38 #define SECTOR_SIZE (1 << SECTOR_BITS)
  39
  40 typedef struct BlockDriverAIOCBSync {
  41     BlockDriverAIOCB common;
  42     QEMUBH *bh;
  43     int ret;
  44 } BlockDriverAIOCBSync;
  45
  46 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
  47         int64_t sector_num, uint8_t *buf, int nb_sectors,
  48         BlockDriverCompletionFunc *cb, void *opaque);
  49 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
  50         int64_t sector_num, const uint8_t *buf, int nb_sectors,
  51         BlockDriverCompletionFunc *cb, void *opaque);
  52 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
  53 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
  54                         uint8_t *buf, int nb_sectors);
  55 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
  56                          const uint8_t *buf, int nb_sectors);
  57
  58 BlockDriverState *bdrv_first;
  59
  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     const char *tmpdir;
 195     /* XXX: race condition possible */
 196     tmpdir = getenv("TMPDIR");
 197     if (!tmpdir)
 198         tmpdir = "/tmp";
 199     snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
 200     fd = mkstemp(filename);
 201     close(fd);
 202 }
 203 #endif
 204
 205 #ifdef _WIN32
 206 static int is_windows_drive_prefix(const char *filename)
 207 {
 208     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
 209              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 210             filename[1] == ':');
 211 }
 212
 213 static int is_windows_drive(const char *filename)
 214 {
 215     if (is_windows_drive_prefix(filename) &&
 216         filename[2] == '\0')
 217         return 1;
 218     if (strstart(filename, "\\\\.\\", NULL) ||
 219         strstart(filename, "//./", NULL))
 220         return 1;
 221     return 0;
 222 }
 223 #endif
 224
 225 static BlockDriver *find_protocol(const char *filename)
 226 {
 227     BlockDriver *drv1;
 228     char protocol[128];
 229     int len;
 230     const char *p;
 231
 232 #ifdef _WIN32
 233     if (is_windows_drive(filename) ||
 234         is_windows_drive_prefix(filename))
 235         return &bdrv_raw;
 236 #endif
 237     p = strchr(filename, ':');
 238     if (!p)
 239         return &bdrv_raw;
 240     len = p - filename;
 241     if (len > sizeof(protocol) - 1)
 242         len = sizeof(protocol) - 1;
 243     memcpy(protocol, filename, len);
 244     protocol[len] = '\0';
 245     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 246         if (drv1->protocol_name &&
 247             !strcmp(drv1->protocol_name, protocol))
 248             return drv1;
 249     }
 250     return NULL;
 251 }
 252
 253 /* XXX: force raw format if block or character device ? It would
 254    simplify the BSD case */
 255 static BlockDriver *find_image_format(const char *filename)
 256 {
 257     int ret, score, score_max;
 258     BlockDriver *drv1, *drv;
 259     uint8_t buf[2048];
 260     BlockDriverState *bs;
 261
 262     /* detect host devices. By convention, /dev/cdrom[N] is always
 263        recognized as a host CDROM */
 264     if (strstart(filename, "/dev/cdrom", NULL))
 265         return &bdrv_host_device;
 266 #ifdef _WIN32
 267     if (is_windows_drive(filename))
 268         return &bdrv_host_device;
 269 #else
 270     {
 271         struct stat st;
 272         if (stat(filename, &st) >= 0 &&
 273             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
 274             return &bdrv_host_device;
 275         }
 276     }
 277 #endif
 278
 279     drv = find_protocol(filename);
 280     /* no need to test disk image formats for vvfat */
 281     if (drv == &bdrv_vvfat)
 282         return drv;
 283
 284     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
 285     if (ret < 0)
 286         return NULL;
 287     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
 288     bdrv_delete(bs);
 289     if (ret < 0) {
 290         return NULL;
 291     }
 292
 293     score_max = 0;
 294     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 295         if (drv1->bdrv_probe) {
 296             score = drv1->bdrv_probe(buf, ret, filename);
 297             if (score > score_max) {
 298                 score_max = score;
 299                 drv = drv1;
 300             }
 301         }
 302     }
 303     return drv;
 304 }
 305
 306 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 307 {
 308     BlockDriverState *bs;
 309     int ret;
 310
 311     bs = bdrv_new("");
 312     if (!bs)
 313         return -ENOMEM;
 314     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
 315     if (ret < 0) {
 316         bdrv_delete(bs);
 317         return ret;
 318     }
 319     *pbs = bs;
 320     return 0;
 321 }
 322
 323 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
 324 {
 325     return bdrv_open2(bs, filename, flags, NULL);
 326 }
 327
 328 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 329                BlockDriver *drv)
 330 {
 331     int ret, open_flags;
 332     char tmp_filename[PATH_MAX];
 333     char backing_filename[PATH_MAX];
 334
 335     bs->read_only = 0;
 336     bs->is_temporary = 0;
 337     bs->encrypted = 0;
 338
 339     if (flags & BDRV_O_SNAPSHOT) {
 340         BlockDriverState *bs1;
 341         int64_t total_size;
 342         int is_protocol = 0;
 343
 344         /* if snapshot, we create a temporary backing file and open it
 345            instead of opening 'filename' directly */
 346
 347         /* if there is a backing file, use it */
 348         bs1 = bdrv_new("");
 349         if (!bs1) {
 350             return -ENOMEM;
 351         }
 352         if (bdrv_open(bs1, filename, 0) < 0) {
 353             bdrv_delete(bs1);
 354             return -1;
 355         }
 356         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
 357
 358         if (bs1->drv && bs1->drv->protocol_name)
 359             is_protocol = 1;
 360
 361         bdrv_delete(bs1);
 362
 363         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 364
 365         /* Real path is meaningless for protocols */
 366         if (is_protocol)
 367             snprintf(backing_filename, sizeof(backing_filename),
 368                      "%s", filename);
 369         else
 370             realpath(filename, backing_filename);
 371
 372         if (bdrv_create(&bdrv_qcow2, tmp_filename,
 373                         total_size, backing_filename, 0) < 0) {
 374             return -1;
 375         }
 376         filename = tmp_filename;
 377         bs->is_temporary = 1;
 378     }
 379
 380     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 381     if (flags & BDRV_O_FILE) {
 382         drv = find_protocol(filename);
 383         if (!drv)
 384             return -ENOENT;
 385     } else {
 386         if (!drv) {
 387             drv = find_image_format(filename);
 388             if (!drv)
 389                 return -1;
 390         }
 391     }
 392     bs->drv = drv;
 393     bs->opaque = qemu_mallocz(drv->instance_size);
 394     if (bs->opaque == NULL && drv->instance_size > 0)
 395         return -1;
 396     /* Note: for compatibility, we open disk image files as RDWR, and
 397        RDONLY as fallback */
 398     if (!(flags & BDRV_O_FILE))
 399         open_flags = BDRV_O_RDWR | (flags & BDRV_O_CACHE_MASK);
 400     else
 401         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
 402     ret = drv->bdrv_open(bs, filename, open_flags);
 403     if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
 404         ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
 405         bs->read_only = 1;
 406     }
 407     if (ret < 0) {
 408         qemu_free(bs->opaque);
 409         bs->opaque = NULL;
 410         bs->drv = NULL;
 411         return ret;
 412     }
 413     if (drv->bdrv_getlength) {
 414         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 415     }
 416 #ifndef _WIN32
 417     if (bs->is_temporary) {
 418         unlink(filename);
 419     }
 420 #endif
 421     if (bs->backing_file[0] != '\0') {
 422         /* if there is a backing file, use it */
 423         bs->backing_hd = bdrv_new("");
 424         if (!bs->backing_hd) {
 425         fail:
 426             bdrv_close(bs);
 427             return -ENOMEM;
 428         }
 429         path_combine(backing_filename, sizeof(backing_filename),
 430                      filename, bs->backing_file);
 431         if (bdrv_open(bs->backing_hd, backing_filename, open_flags) < 0)
 432             goto fail;
 433     }
 434
 435     /* call the change callback */
 436     bs->media_changed = 1;
 437     if (bs->change_cb)
 438         bs->change_cb(bs->change_opaque);
 439
 440     return 0;
 441 }
 442
 443 void bdrv_close(BlockDriverState *bs)
 444 {
 445     if (bs->drv) {
 446         if (bs->backing_hd)
 447             bdrv_delete(bs->backing_hd);
 448         bs->drv->bdrv_close(bs);
 449         qemu_free(bs->opaque);
 450 #ifdef _WIN32
 451         if (bs->is_temporary) {
 452             unlink(bs->filename);
 453         }
 454 #endif
 455         bs->opaque = NULL;
 456         bs->drv = NULL;
 457
 458         /* call the change callback */
 459         bs->media_changed = 1;
 460         if (bs->change_cb)
 461             bs->change_cb(bs->change_opaque);
 462     }
 463 }
 464
 465 void bdrv_delete(BlockDriverState *bs)
 466 {
 467     BlockDriverState **pbs;
 468
 469     pbs = &bdrv_first;
 470     while (*pbs != bs && *pbs != NULL)
 471         pbs = &(*pbs)->next;
 472     if (*pbs == bs)
 473         *pbs = bs->next;
 474
 475     bdrv_close(bs);
 476     qemu_free(bs);
 477 }
 478
 479 /* commit COW file into the raw image */
 480 int bdrv_commit(BlockDriverState *bs)
 481 {
 482     BlockDriver *drv = bs->drv;
 483     int64_t i, total_sectors;
 484     int n, j;
 485     unsigned char sector[512];
 486
 487     if (!drv)
 488         return -ENOMEDIUM;
 489
 490     if (bs->read_only) {
 491         return -EACCES;
 492     }
 493
 494     if (!bs->backing_hd) {
 495         return -ENOTSUP;
 496     }
 497
 498     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 499     for (i = 0; i < total_sectors;) {
 500         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 501             for(j = 0; j < n; j++) {
 502                 if (bdrv_read(bs, i, sector, 1) != 0) {
 503                     return -EIO;
 504                 }
 505
 506                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 507                     return -EIO;
 508                 }
 509                 i++;
 510             }
 511         } else {
 512             i += n;
 513         }
 514     }
 515
 516     if (drv->bdrv_make_empty)
 517         return drv->bdrv_make_empty(bs);
 518
 519     return 0;
 520 }
 521
 522 /* return < 0 if error. See bdrv_write() for the return codes */
 523 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 524               uint8_t *buf, int nb_sectors)
 525 {
 526     BlockDriver *drv = bs->drv;
 527
 528     if (!drv)
 529         return -ENOMEDIUM;
 530
 531     if (drv->bdrv_pread) {
 532         int ret, len;
 533         len = nb_sectors * 512;
 534         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 535         if (ret < 0)
 536             return ret;
 537         else if (ret != len)
 538             return -EINVAL;
 539         else {
 540             bs->rd_bytes += (unsigned) len;
 541             bs->rd_ops ++;
 542             return 0;
 543         }
 544     } else {
 545         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 546     }
 547 }
 548
 549 /* Return < 0 if error. Important errors are:
 550   -EIO         generic I/O error (may happen for all errors)
 551   -ENOMEDIUM   No media inserted.
 552   -EINVAL      Invalid sector number or nb_sectors
 553   -EACCES      Trying to write a read-only device
 554 */
 555 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 556                const uint8_t *buf, int nb_sectors)
 557 {
 558     BlockDriver *drv = bs->drv;
 559     if (!bs->drv)
 560         return -ENOMEDIUM;
 561     if (bs->read_only)
 562         return -EACCES;
 563     if (drv->bdrv_pwrite) {
 564         int ret, len;
 565         len = nb_sectors * 512;
 566         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 567         if (ret < 0)
 568             return ret;
 569         else if (ret != len)
 570             return -EIO;
 571         else {
 572             bs->wr_bytes += (unsigned) len;
 573             bs->wr_ops ++;
 574             return 0;
 575         }
 576     } else {
 577         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 578     }
 579 }
 580
 581 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 582                          uint8_t *buf, int count1)
 583 {
 584     uint8_t tmp_buf[SECTOR_SIZE];
 585     int len, nb_sectors, count;
 586     int64_t sector_num;
 587
 588     count = count1;
 589     /* first read to align to sector start */
 590     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 591     if (len > count)
 592         len = count;
 593     sector_num = offset >> SECTOR_BITS;
 594     if (len > 0) {
 595         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 596             return -EIO;
 597         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 598         count -= len;
 599         if (count == 0)
 600             return count1;
 601         sector_num++;
 602         buf += len;
 603     }
 604
 605     /* read the sectors "in place" */
 606     nb_sectors = count >> SECTOR_BITS;
 607     if (nb_sectors > 0) {
 608         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 609             return -EIO;
 610         sector_num += nb_sectors;
 611         len = nb_sectors << SECTOR_BITS;
 612         buf += len;
 613         count -= len;
 614     }
 615
 616     /* add data from the last sector */
 617     if (count > 0) {
 618         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 619             return -EIO;
 620         memcpy(buf, tmp_buf, count);
 621     }
 622     return count1;
 623 }
 624
 625 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 626                           const uint8_t *buf, int count1)
 627 {
 628     uint8_t tmp_buf[SECTOR_SIZE];
 629     int len, nb_sectors, count;
 630     int64_t sector_num;
 631
 632     count = count1;
 633     /* first write to align to sector start */
 634     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 635     if (len > count)
 636         len = count;
 637     sector_num = offset >> SECTOR_BITS;
 638     if (len > 0) {
 639         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 640             return -EIO;
 641         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 642         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 643             return -EIO;
 644         count -= len;
 645         if (count == 0)
 646             return count1;
 647         sector_num++;
 648         buf += len;
 649     }
 650
 651     /* write the sectors "in place" */
 652     nb_sectors = count >> SECTOR_BITS;
 653     if (nb_sectors > 0) {
 654         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 655             return -EIO;
 656         sector_num += nb_sectors;
 657         len = nb_sectors << SECTOR_BITS;
 658         buf += len;
 659         count -= len;
 660     }
 661
 662     /* add data from the last sector */
 663     if (count > 0) {
 664         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 665             return -EIO;
 666         memcpy(tmp_buf, buf, count);
 667         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 668             return -EIO;
 669     }
 670     return count1;
 671 }
 672
 673 /**
 674  * Read with byte offsets (needed only for file protocols)
 675  */
 676 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 677                void *buf1, int count1)
 678 {
 679     BlockDriver *drv = bs->drv;
 680
 681     if (!drv)
 682         return -ENOMEDIUM;
 683     if (!drv->bdrv_pread)
 684         return bdrv_pread_em(bs, offset, buf1, count1);
 685     return drv->bdrv_pread(bs, offset, buf1, count1);
 686 }
 687
 688 /**
 689  * Write with byte offsets (needed only for file protocols)
 690  */
 691 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 692                 const void *buf1, int count1)
 693 {
 694     BlockDriver *drv = bs->drv;
 695
 696     if (!drv)
 697         return -ENOMEDIUM;
 698     if (!drv->bdrv_pwrite)
 699         return bdrv_pwrite_em(bs, offset, buf1, count1);
 700     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 701 }
 702
 703 /**
 704  * Truncate file to 'offset' bytes (needed only for file protocols)
 705  */
 706 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 707 {
 708     BlockDriver *drv = bs->drv;
 709     if (!drv)
 710         return -ENOMEDIUM;
 711     if (!drv->bdrv_truncate)
 712         return -ENOTSUP;
 713     return drv->bdrv_truncate(bs, offset);
 714 }
 715
 716 /**
 717  * Length of a file in bytes. Return < 0 if error or unknown.
 718  */
 719 int64_t bdrv_getlength(BlockDriverState *bs)
 720 {
 721     BlockDriver *drv = bs->drv;
 722     if (!drv)
 723         return -ENOMEDIUM;
 724     if (!drv->bdrv_getlength) {
 725         /* legacy mode */
 726         return bs->total_sectors * SECTOR_SIZE;
 727     }
 728     return drv->bdrv_getlength(bs);
 729 }
 730
 731 /* return 0 as number of sectors if no device present or error */
 732 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 733 {
 734     int64_t length;
 735     length = bdrv_getlength(bs);
 736     if (length < 0)
 737         length = 0;
 738     else
 739         length = length >> SECTOR_BITS;
 740     *nb_sectors_ptr = length;
 741 }
 742
 743 struct partition {
 744         uint8_t boot_ind;               /* 0x80 - active */
 745         uint8_t head;           /* starting head */
 746         uint8_t sector;         /* starting sector */
 747         uint8_t cyl;            /* starting cylinder */
 748         uint8_t sys_ind;                /* What partition type */
 749         uint8_t end_head;               /* end head */
 750         uint8_t end_sector;     /* end sector */
 751         uint8_t end_cyl;                /* end cylinder */
 752         uint32_t start_sect;    /* starting sector counting from 0 */
 753         uint32_t nr_sects;              /* nr of sectors in partition */
 754 } __attribute__((packed));
 755
 756 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
 757 static int guess_disk_lchs(BlockDriverState *bs,
 758                            int *pcylinders, int *pheads, int *psectors)
 759 {
 760     uint8_t *buf;
 761     int ret, i, heads, sectors, cylinders;
 762     struct partition *p;
 763     uint32_t nr_sects;
 764     int64_t nb_sectors;
 765
 766     buf = qemu_memalign(512, 512);
 767     if (buf == NULL)
 768         return -1;
 769
 770     bdrv_get_geometry(bs, &nb_sectors);
 771
 772     ret = bdrv_read(bs, 0, buf, 1);
 773     if (ret < 0)
 774         return -1;
 775     /* test msdos magic */
 776     if (buf[510] != 0x55 || buf[511] != 0xaa) {
 777         qemu_free(buf);
 778         return -1;
 779     }
 780     for(i = 0; i < 4; i++) {
 781         p = ((struct partition *)(buf + 0x1be)) + i;
 782         nr_sects = le32_to_cpu(p->nr_sects);
 783         if (nr_sects && p->end_head) {
 784             /* We make the assumption that the partition terminates on
 785                a cylinder boundary */
 786             heads = p->end_head + 1;
 787             sectors = p->end_sector & 63;
 788             if (sectors == 0)
 789                 continue;
 790             cylinders = nb_sectors / (heads * sectors);
 791             if (cylinders < 1 || cylinders > 16383)
 792                 continue;
 793             *pheads = heads;
 794             *psectors = sectors;
 795             *pcylinders = cylinders;
 796 #if 0
 797             printf("guessed geometry: LCHS=%d %d %d\n",
 798                    cylinders, heads, sectors);
 799 #endif
 800             qemu_free(buf);
 801             return 0;
 802         }
 803     }
 804     qemu_free(buf);
 805     return -1;
 806 }
 807
 808 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
 809 {
 810     int translation, lba_detected = 0;
 811     int cylinders, heads, secs;
 812     int64_t nb_sectors;
 813
 814     /* if a geometry hint is available, use it */
 815     bdrv_get_geometry(bs, &nb_sectors);
 816     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
 817     translation = bdrv_get_translation_hint(bs);
 818     if (cylinders != 0) {
 819         *pcyls = cylinders;
 820         *pheads = heads;
 821         *psecs = secs;
 822     } else {
 823         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
 824             if (heads > 16) {
 825                 /* if heads > 16, it means that a BIOS LBA
 826                    translation was active, so the default
 827                    hardware geometry is OK */
 828                 lba_detected = 1;
 829                 goto default_geometry;
 830             } else {
 831                 *pcyls = cylinders;
 832                 *pheads = heads;
 833                 *psecs = secs;
 834                 /* disable any translation to be in sync with
 835                    the logical geometry */
 836                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
 837                     bdrv_set_translation_hint(bs,
 838                                               BIOS_ATA_TRANSLATION_NONE);
 839                 }
 840             }
 841         } else {
 842         default_geometry:
 843             /* if no geometry, use a standard physical disk geometry */
 844             cylinders = nb_sectors / (16 * 63);
 845
 846             if (cylinders > 16383)
 847                 cylinders = 16383;
 848             else if (cylinders < 2)
 849                 cylinders = 2;
 850             *pcyls = cylinders;
 851             *pheads = 16;
 852             *psecs = 63;
 853             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
 854                 if ((*pcyls * *pheads) <= 131072) {
 855                     bdrv_set_translation_hint(bs,
 856                                               BIOS_ATA_TRANSLATION_LARGE);
 857                 } else {
 858                     bdrv_set_translation_hint(bs,
 859                                               BIOS_ATA_TRANSLATION_LBA);
 860                 }
 861             }
 862         }
 863         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
 864     }
 865 }
 866
 867 void bdrv_set_geometry_hint(BlockDriverState *bs,
 868                             int cyls, int heads, int secs)
 869 {
 870     bs->cyls = cyls;
 871     bs->heads = heads;
 872     bs->secs = secs;
 873 }
 874
 875 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 876 {
 877     bs->type = type;
 878     bs->removable = ((type == BDRV_TYPE_CDROM ||
 879                       type == BDRV_TYPE_FLOPPY));
 880 }
 881
 882 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 883 {
 884     bs->translation = translation;
 885 }
 886
 887 void bdrv_get_geometry_hint(BlockDriverState *bs,
 888                             int *pcyls, int *pheads, int *psecs)
 889 {
 890     *pcyls = bs->cyls;
 891     *pheads = bs->heads;
 892     *psecs = bs->secs;
 893 }
 894
 895 int bdrv_get_type_hint(BlockDriverState *bs)
 896 {
 897     return bs->type;
 898 }
 899
 900 int bdrv_get_translation_hint(BlockDriverState *bs)
 901 {
 902     return bs->translation;
 903 }
 904
 905 int bdrv_is_removable(BlockDriverState *bs)
 906 {
 907     return bs->removable;
 908 }
 909
 910 int bdrv_is_read_only(BlockDriverState *bs)
 911 {
 912     return bs->read_only;
 913 }
 914
 915 int bdrv_is_sg(BlockDriverState *bs)
 916 {
 917     return bs->sg;
 918 }
 919
 920 /* XXX: no longer used */
 921 void bdrv_set_change_cb(BlockDriverState *bs,
 922                         void (*change_cb)(void *opaque), void *opaque)
 923 {
 924     bs->change_cb = change_cb;
 925     bs->change_opaque = opaque;
 926 }
 927
 928 int bdrv_is_encrypted(BlockDriverState *bs)
 929 {
 930     if (bs->backing_hd && bs->backing_hd->encrypted)
 931         return 1;
 932     return bs->encrypted;
 933 }
 934
 935 int bdrv_set_key(BlockDriverState *bs, const char *key)
 936 {
 937     int ret;
 938     if (bs->backing_hd && bs->backing_hd->encrypted) {
 939         ret = bdrv_set_key(bs->backing_hd, key);
 940         if (ret < 0)
 941             return ret;
 942         if (!bs->encrypted)
 943             return 0;
 944     }
 945     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 946         return -1;
 947     return bs->drv->bdrv_set_key(bs, key);
 948 }
 949
 950 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 951 {
 952     if (!bs->drv) {
 953         buf[0] = '\0';
 954     } else {
 955         pstrcpy(buf, buf_size, bs->drv->format_name);
 956     }
 957 }
 958
 959 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 960                          void *opaque)
 961 {
 962     BlockDriver *drv;
 963
 964     for (drv = first_drv; drv != NULL; drv = drv->next) {
 965         it(opaque, drv->format_name);
 966     }
 967 }
 968
 969 BlockDriverState *bdrv_find(const char *name)
 970 {
 971     BlockDriverState *bs;
 972
 973     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 974         if (!strcmp(name, bs->device_name))
 975             return bs;
 976     }
 977     return NULL;
 978 }
 979
 980 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 981 {
 982     BlockDriverState *bs;
 983
 984     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 985         it(opaque, bs->device_name);
 986     }
 987 }
 988
 989 const char *bdrv_get_device_name(BlockDriverState *bs)
 990 {
 991     return bs->device_name;
 992 }
 993
 994 void bdrv_flush(BlockDriverState *bs)
 995 {
 996     if (bs->drv->bdrv_flush)
 997         bs->drv->bdrv_flush(bs);
 998     if (bs->backing_hd)
 999         bdrv_flush(bs->backing_hd);
1000 }
1001
1002 void bdrv_iterate_writeable(void (*it)(BlockDriverState *bs))
1003 {
1004     BlockDriverState *bs;
1005
1006     for (bs = bdrv_first; bs != NULL; bs = bs->next)
1007         if (bs->drv && !bdrv_is_read_only(bs) &&
1008             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1009             it(bs);
1010 }
1011
1012 void bdrv_flush_all(void)
1013 {
1014     BlockDriverState *bs;
1015
1016     for (bs = bdrv_first; bs != NULL; bs = bs->next)
1017         if (bs->drv && !bdrv_is_read_only(bs) &&
1018             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1019             bdrv_flush(bs);
1020 }
1021
1022 /*
1023  * Returns true iff the specified sector is present in the disk image. Drivers
1024  * not implementing the functionality are assumed to not support backing files,
1025  * hence all their sectors are reported as allocated.
1026  *
1027  * 'pnum' is set to the number of sectors (including and immediately following
1028  * the specified sector) that are known to be in the same
1029  * allocated/unallocated state.
1030  *
1031  * 'nb_sectors' is the max value 'pnum' should be set to.
1032  */
1033 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1034         int *pnum)
1035 {
1036     int64_t n;
1037     if (!bs->drv->bdrv_is_allocated) {
1038         if (sector_num >= bs->total_sectors) {
1039             *pnum = 0;
1040             return 0;
1041         }
1042         n = bs->total_sectors - sector_num;
1043         *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1044         return 1;
1045     }
1046     return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1047 }
1048
1049 void bdrv_info(void)
1050 {
1051     BlockDriverState *bs;
1052
1053     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1054         term_printf("%s:", bs->device_name);
1055         term_printf(" type=");
1056         switch(bs->type) {
1057         case BDRV_TYPE_HD:
1058             term_printf("hd");
1059             break;
1060         case BDRV_TYPE_CDROM:
1061             term_printf("cdrom");
1062             break;
1063         case BDRV_TYPE_FLOPPY:
1064             term_printf("floppy");
1065             break;
1066         }
1067         term_printf(" removable=%d", bs->removable);
1068         if (bs->removable) {
1069             term_printf(" locked=%d", bs->locked);
1070         }
1071         if (bs->drv) {
1072             term_printf(" file=");
1073             term_print_filename(bs->filename);
1074             if (bs->backing_file[0] != '\0') {
1075                 term_printf(" backing_file=");
1076                 term_print_filename(bs->backing_file);
1077             }
1078             term_printf(" ro=%d", bs->read_only);
1079             term_printf(" drv=%s", bs->drv->format_name);
1080             if (bs->encrypted)
1081                 term_printf(" encrypted");
1082         } else {
1083             term_printf(" [not inserted]");
1084         }
1085         term_printf("\n");
1086     }
1087 }
1088
1089 /* The "info blockstats" command. */
1090 void bdrv_info_stats (void)
1091 {
1092     BlockDriverState *bs;
1093
1094     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1095         term_printf ("%s:"
1096                      " rd_bytes=%" PRIu64
1097                      " wr_bytes=%" PRIu64
1098                      " rd_operations=%" PRIu64
1099                      " wr_operations=%" PRIu64
1100                      "\n",
1101                      bs->device_name,
1102                      bs->rd_bytes, bs->wr_bytes,
1103                      bs->rd_ops, bs->wr_ops);
1104     }
1105 }
1106
1107 void bdrv_get_backing_filename(BlockDriverState *bs,
1108                                char *filename, int filename_size)
1109 {
1110     if (!bs->backing_hd) {
1111         pstrcpy(filename, filename_size, "");
1112     } else {
1113         pstrcpy(filename, filename_size, bs->backing_file);
1114     }
1115 }
1116
1117 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1118                           const uint8_t *buf, int nb_sectors)
1119 {
1120     BlockDriver *drv = bs->drv;
1121     if (!drv)
1122         return -ENOMEDIUM;
1123     if (!drv->bdrv_write_compressed)
1124         return -ENOTSUP;
1125     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1126 }
1127
1128 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1129 {
1130     BlockDriver *drv = bs->drv;
1131     if (!drv)
1132         return -ENOMEDIUM;
1133     if (!drv->bdrv_get_info)
1134         return -ENOTSUP;
1135     memset(bdi, 0, sizeof(*bdi));
1136     return drv->bdrv_get_info(bs, bdi);
1137 }
1138
1139 /**************************************************************/
1140 /* handling of snapshots */
1141
1142 int bdrv_snapshot_create(BlockDriverState *bs,
1143                          QEMUSnapshotInfo *sn_info)
1144 {
1145     BlockDriver *drv = bs->drv;
1146     if (!drv)
1147         return -ENOMEDIUM;
1148     if (!drv->bdrv_snapshot_create)
1149         return -ENOTSUP;
1150     return drv->bdrv_snapshot_create(bs, sn_info);
1151 }
1152
1153 int bdrv_snapshot_goto(BlockDriverState *bs,
1154                        const char *snapshot_id)
1155 {
1156     BlockDriver *drv = bs->drv;
1157     if (!drv)
1158         return -ENOMEDIUM;
1159     if (!drv->bdrv_snapshot_goto)
1160         return -ENOTSUP;
1161     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1162 }
1163
1164 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1165 {
1166     BlockDriver *drv = bs->drv;
1167     if (!drv)
1168         return -ENOMEDIUM;
1169     if (!drv->bdrv_snapshot_delete)
1170         return -ENOTSUP;
1171     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1172 }
1173
1174 int bdrv_snapshot_list(BlockDriverState *bs,
1175                        QEMUSnapshotInfo **psn_info)
1176 {
1177     BlockDriver *drv = bs->drv;
1178     if (!drv)
1179         return -ENOMEDIUM;
1180     if (!drv->bdrv_snapshot_list)
1181         return -ENOTSUP;
1182     return drv->bdrv_snapshot_list(bs, psn_info);
1183 }
1184
1185 #define NB_SUFFIXES 4
1186
1187 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1188 {
1189     static const char suffixes[NB_SUFFIXES] = "KMGT";
1190     int64_t base;
1191     int i;
1192
1193     if (size <= 999) {
1194         snprintf(buf, buf_size, "%" PRId64, size);
1195     } else {
1196         base = 1024;
1197         for(i = 0; i < NB_SUFFIXES; i++) {
1198             if (size < (10 * base)) {
1199                 snprintf(buf, buf_size, "%0.1f%c",
1200                          (double)size / base,
1201                          suffixes[i]);
1202                 break;
1203             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1204                 snprintf(buf, buf_size, "%" PRId64 "%c",
1205                          ((size + (base >> 1)) / base),
1206                          suffixes[i]);
1207                 break;
1208             }
1209             base = base * 1024;
1210         }
1211     }
1212     return buf;
1213 }
1214
1215 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1216 {
1217     char buf1[128], date_buf[128], clock_buf[128];
1218 #ifdef _WIN32
1219     struct tm *ptm;
1220 #else
1221     struct tm tm;
1222 #endif
1223     time_t ti;
1224     int64_t secs;
1225
1226     if (!sn) {
1227         snprintf(buf, buf_size,
1228                  "%-10s%-20s%7s%20s%15s",
1229                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1230     } else {
1231         ti = sn->date_sec;
1232 #ifdef _WIN32
1233         ptm = localtime(&ti);
1234         strftime(date_buf, sizeof(date_buf),
1235                  "%Y-%m-%d %H:%M:%S", ptm);
1236 #else
1237         localtime_r(&ti, &tm);
1238         strftime(date_buf, sizeof(date_buf),
1239                  "%Y-%m-%d %H:%M:%S", &tm);
1240 #endif
1241         secs = sn->vm_clock_nsec / 1000000000;
1242         snprintf(clock_buf, sizeof(clock_buf),
1243                  "%02d:%02d:%02d.%03d",
1244                  (int)(secs / 3600),
1245                  (int)((secs / 60) % 60),
1246                  (int)(secs % 60),
1247                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1248         snprintf(buf, buf_size,
1249                  "%-10s%-20s%7s%20s%15s",
1250                  sn->id_str, sn->name,
1251                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1252                  date_buf,
1253                  clock_buf);
1254     }
1255     return buf;
1256 }
1257
1258
1259 /**************************************************************/
1260 /* async I/Os */
1261
1262 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1263                                 uint8_t *buf, int nb_sectors,
1264                                 BlockDriverCompletionFunc *cb, void *opaque)
1265 {
1266     BlockDriver *drv = bs->drv;
1267     BlockDriverAIOCB *ret;
1268
1269     if (!drv)
1270         return NULL;
1271
1272     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1273
1274     if (ret) {
1275         /* Update stats even though technically transfer has not happened. */
1276         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1277         bs->rd_ops ++;
1278     }
1279
1280     return ret;
1281 }
1282
1283 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1284                                  const uint8_t *buf, int nb_sectors,
1285                                  BlockDriverCompletionFunc *cb, void *opaque)
1286 {
1287     BlockDriver *drv = bs->drv;
1288     BlockDriverAIOCB *ret;
1289
1290     if (!drv)
1291         return NULL;
1292     if (bs->read_only)
1293         return NULL;
1294
1295     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1296
1297     if (ret) {
1298         /* Update stats even though technically transfer has not happened. */
1299         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1300         bs->wr_ops ++;
1301     }
1302
1303     return ret;
1304 }
1305
1306 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1307 {
1308     BlockDriver *drv = acb->bs->drv;
1309
1310     drv->bdrv_aio_cancel(acb);
1311 }
1312
1313
1314 /**************************************************************/
1315 /* async block device emulation */
1316
1317 static void bdrv_aio_bh_cb(void *opaque)
1318 {
1319     BlockDriverAIOCBSync *acb = opaque;
1320     acb->common.cb(acb->common.opaque, acb->ret);
1321     qemu_aio_release(acb);
1322 }
1323
1324 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1325         int64_t sector_num, uint8_t *buf, int nb_sectors,
1326         BlockDriverCompletionFunc *cb, void *opaque)
1327 {
1328     BlockDriverAIOCBSync *acb;
1329     int ret;
1330
1331     acb = qemu_aio_get(bs, cb, opaque);
1332     if (!acb->bh)
1333         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1334     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1335     acb->ret = ret;
1336     qemu_bh_schedule(acb->bh);
1337     return &acb->common;
1338 }
1339
1340 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1341         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1342         BlockDriverCompletionFunc *cb, void *opaque)
1343 {
1344     BlockDriverAIOCBSync *acb;
1345     int ret;
1346
1347     acb = qemu_aio_get(bs, cb, opaque);
1348     if (!acb->bh)
1349         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1350     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1351     acb->ret = ret;
1352     qemu_bh_schedule(acb->bh);
1353     return &acb->common;
1354 }
1355
1356 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1357 {
1358     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1359     qemu_bh_cancel(acb->bh);
1360     qemu_aio_release(acb);
1361 }
1362
1363 /**************************************************************/
1364 /* sync block device emulation */
1365
1366 static void bdrv_rw_em_cb(void *opaque, int ret)
1367 {
1368     *(int *)opaque = ret;
1369 }
1370
1371 #define NOT_DONE 0x7fffffff
1372
1373 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1374                         uint8_t *buf, int nb_sectors)
1375 {
1376     int async_ret;
1377     BlockDriverAIOCB *acb;
1378
1379     async_ret = NOT_DONE;
1380     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1381                         bdrv_rw_em_cb, &async_ret);
1382     if (acb == NULL)
1383         return -1;
1384
1385     while (async_ret == NOT_DONE) {
1386         qemu_aio_wait();
1387     }
1388
1389     return async_ret;
1390 }
1391
1392 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1393                          const uint8_t *buf, int nb_sectors)
1394 {
1395     int async_ret;
1396     BlockDriverAIOCB *acb;
1397
1398     async_ret = NOT_DONE;
1399     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1400                          bdrv_rw_em_cb, &async_ret);
1401     if (acb == NULL)
1402         return -1;
1403     while (async_ret == NOT_DONE) {
1404         qemu_aio_wait();
1405     }
1406     return async_ret;
1407 }
1408
1409 void bdrv_init(void)
1410 {
1411     bdrv_register(&bdrv_raw);
1412     bdrv_register(&bdrv_host_device);
1413 #ifndef _WIN32
1414     bdrv_register(&bdrv_cow);
1415 #endif
1416     bdrv_register(&bdrv_qcow);
1417     bdrv_register(&bdrv_vmdk);
1418     bdrv_register(&bdrv_cloop);
1419     bdrv_register(&bdrv_dmg);
1420     bdrv_register(&bdrv_bochs);
1421     bdrv_register(&bdrv_vpc);
1422     bdrv_register(&bdrv_vvfat);
1423     bdrv_register(&bdrv_qcow2);
1424     bdrv_register(&bdrv_parallels);
1425     bdrv_register(&bdrv_nbd);
1426 }
1427
1428 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1429                    void *opaque)
1430 {
1431     BlockDriver *drv;
1432     BlockDriverAIOCB *acb;
1433
1434     drv = bs->drv;
1435     if (drv->free_aiocb) {
1436         acb = drv->free_aiocb;
1437         drv->free_aiocb = acb->next;
1438     } else {
1439         acb = qemu_mallocz(drv->aiocb_size);
1440         if (!acb)
1441             return NULL;
1442     }
1443     acb->bs = bs;
1444     acb->cb = cb;
1445     acb->opaque = opaque;
1446     return acb;
1447 }
1448
1449 void qemu_aio_release(void *p)
1450 {
1451     BlockDriverAIOCB *acb = p;
1452     BlockDriver *drv = acb->bs->drv;
1453     acb->next = drv->free_aiocb;
1454     drv->free_aiocb = acb;
1455 }
1456
1457 /**************************************************************/
1458 /* removable device support */
1459
1460 /**
1461  * Return TRUE if the media is present
1462  */
1463 int bdrv_is_inserted(BlockDriverState *bs)
1464 {
1465     BlockDriver *drv = bs->drv;
1466     int ret;
1467     if (!drv)
1468         return 0;
1469     if (!drv->bdrv_is_inserted)
1470         return 1;
1471     ret = drv->bdrv_is_inserted(bs);
1472     return ret;
1473 }
1474
1475 /**
1476  * Return TRUE if the media changed since the last call to this
1477  * function. It is currently only used for floppy disks
1478  */
1479 int bdrv_media_changed(BlockDriverState *bs)
1480 {
1481     BlockDriver *drv = bs->drv;
1482     int ret;
1483
1484     if (!drv || !drv->bdrv_media_changed)
1485         ret = -ENOTSUP;
1486     else
1487         ret = drv->bdrv_media_changed(bs);
1488     if (ret == -ENOTSUP)
1489         ret = bs->media_changed;
1490     bs->media_changed = 0;
1491     return ret;
1492 }
1493
1494 /**
1495  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1496  */
1497 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1498 {
1499     BlockDriver *drv = bs->drv;
1500     int ret;
1501
1502     if (!drv || !drv->bdrv_eject) {
1503         ret = -ENOTSUP;
1504     } else {
1505         ret = drv->bdrv_eject(bs, eject_flag);
1506     }
1507     if (ret == -ENOTSUP) {
1508         if (eject_flag)
1509             bdrv_close(bs);
1510     }
1511 }
1512
1513 int bdrv_is_locked(BlockDriverState *bs)
1514 {
1515     return bs->locked;
1516 }
1517
1518 /**
1519  * Lock or unlock the media (if it is locked, the user won't be able
1520  * to eject it manually).
1521  */
1522 void bdrv_set_locked(BlockDriverState *bs, int locked)
1523 {
1524     BlockDriver *drv = bs->drv;
1525
1526     bs->locked = locked;
1527     if (drv && drv->bdrv_set_locked) {
1528         drv->bdrv_set_locked(bs, locked);
1529     }
1530 }
1531
1532 /* needed for generic scsi interface */
1533
1534 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1535 {
1536     BlockDriver *drv = bs->drv;
1537
1538     if (drv && drv->bdrv_ioctl)
1539         return drv->bdrv_ioctl(bs, req, buf);
1540     return -ENOTSUP;
1541 }