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 #include "osdep.h"
  30
  31 #ifdef _BSD
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/queue.h>
  36 #include <sys/disk.h>
  37 #endif
  38
  39 #define SECTOR_BITS 9
  40 #define SECTOR_SIZE (1 << SECTOR_BITS)
  41
  42 typedef struct BlockDriverAIOCBSync {
  43     BlockDriverAIOCB common;
  44     QEMUBH *bh;
  45     int ret;
  46 } BlockDriverAIOCBSync;
  47
  48 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
  49         int64_t sector_num, uint8_t *buf, int nb_sectors,
  50         BlockDriverCompletionFunc *cb, void *opaque);
  51 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
  52         int64_t sector_num, const uint8_t *buf, int nb_sectors,
  53         BlockDriverCompletionFunc *cb, void *opaque);
  54 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
  55 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
  56                         uint8_t *buf, int nb_sectors);
  57 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
  58                          const uint8_t *buf, int nb_sectors);
  59
  60 BlockDriverState *bdrv_first;
  61 static BlockDriver *first_drv;
  62
  63 int path_is_absolute(const char *path)
  64 {
  65     const char *p;
  66 #ifdef _WIN32
  67     /* specific case for names like: "\\.\d:" */
  68     if (*path == '/' || *path == '\\')
  69         return 1;
  70 #endif
  71     p = strchr(path, ':');
  72     if (p)
  73         p++;
  74     else
  75         p = path;
  76 #ifdef _WIN32
  77     return (*p == '/' || *p == '\\');
  78 #else
  79     return (*p == '/');
  80 #endif
  81 }
  82
  83 /* if filename is absolute, just copy it to dest. Otherwise, build a
  84    path to it by considering it is relative to base_path. URL are
  85    supported. */
  86 void path_combine(char *dest, int dest_size,
  87                   const char *base_path,
  88                   const char *filename)
  89 {
  90     const char *p, *p1;
  91     int len;
  92
  93     if (dest_size <= 0)
  94         return;
  95     if (path_is_absolute(filename)) {
  96         pstrcpy(dest, dest_size, filename);
  97     } else {
  98         p = strchr(base_path, ':');
  99         if (p)
 100             p++;
 101         else
 102             p = base_path;
 103         p1 = strrchr(base_path, '/');
 104 #ifdef _WIN32
 105         {
 106             const char *p2;
 107             p2 = strrchr(base_path, '\\');
 108             if (!p1 || p2 > p1)
 109                 p1 = p2;
 110         }
 111 #endif
 112         if (p1)
 113             p1++;
 114         else
 115             p1 = base_path;
 116         if (p1 > p)
 117             p = p1;
 118         len = p - base_path;
 119         if (len > dest_size - 1)
 120             len = dest_size - 1;
 121         memcpy(dest, base_path, len);
 122         dest[len] = '\0';
 123         pstrcat(dest, dest_size, filename);
 124     }
 125 }
 126
 127
 128 static void bdrv_register(BlockDriver *bdrv)
 129 {
 130     if (!bdrv->bdrv_aio_read) {
 131         /* add AIO emulation layer */
 132         bdrv->bdrv_aio_read = bdrv_aio_read_em;
 133         bdrv->bdrv_aio_write = bdrv_aio_write_em;
 134         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
 135         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
 136     } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
 137         /* add synchronous IO emulation layer */
 138         bdrv->bdrv_read = bdrv_read_em;
 139         bdrv->bdrv_write = bdrv_write_em;
 140     }
 141     bdrv->next = first_drv;
 142     first_drv = bdrv;
 143 }
 144
 145 /* create a new block device (by default it is empty) */
 146 BlockDriverState *bdrv_new(const char *device_name)
 147 {
 148     BlockDriverState **pbs, *bs;
 149
 150     bs = qemu_mallocz(sizeof(BlockDriverState));
 151     if(!bs)
 152         return NULL;
 153     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
 154     if (device_name[0] != '\0') {
 155         /* insert at the end */
 156         pbs = &bdrv_first;
 157         while (*pbs != NULL)
 158             pbs = &(*pbs)->next;
 159         *pbs = bs;
 160     }
 161     return bs;
 162 }
 163
 164 BlockDriver *bdrv_find_format(const char *format_name)
 165 {
 166     BlockDriver *drv1;
 167     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 168         if (!strcmp(drv1->format_name, format_name))
 169             return drv1;
 170     }
 171     return NULL;
 172 }
 173
 174 int bdrv_create(BlockDriver *drv,
 175                 const char *filename, int64_t size_in_sectors,
 176                 const char *backing_file, int flags)
 177 {
 178     if (!drv->bdrv_create)
 179         return -ENOTSUP;
 180     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
 181 }
 182
 183 #ifdef _WIN32
 184 void get_tmp_filename(char *filename, int size)
 185 {
 186     char temp_dir[MAX_PATH];
 187
 188     GetTempPath(MAX_PATH, temp_dir);
 189     GetTempFileName(temp_dir, "qem", 0, filename);
 190 }
 191 #else
 192 void get_tmp_filename(char *filename, int size)
 193 {
 194     int fd;
 195     /* XXX: race condition possible */
 196     pstrcpy(filename, size, "/tmp/vl.XXXXXX");
 197     fd = mkstemp(filename);
 198     close(fd);
 199 }
 200 #endif
 201
 202 #ifdef _WIN32
 203 static int is_windows_drive_prefix(const char *filename)
 204 {
 205     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
 206              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 207             filename[1] == ':');
 208 }
 209
 210 static int is_windows_drive(const char *filename)
 211 {
 212     if (is_windows_drive_prefix(filename) &&
 213         filename[2] == '\0')
 214         return 1;
 215     if (strstart(filename, "\\\\.\\", NULL) ||
 216         strstart(filename, "//./", NULL))
 217         return 1;
 218     return 0;
 219 }
 220 #endif
 221
 222 static BlockDriver *find_protocol(const char *filename)
 223 {
 224     BlockDriver *drv1;
 225     char protocol[128];
 226     int len;
 227     const char *p;
 228
 229 #ifdef _WIN32
 230     if (is_windows_drive(filename) ||
 231         is_windows_drive_prefix(filename))
 232         return &bdrv_raw;
 233 #endif
 234     p = strchr(filename, ':');
 235     if (!p)
 236         return &bdrv_raw;
 237     len = p - filename;
 238     if (len > sizeof(protocol) - 1)
 239         len = sizeof(protocol) - 1;
 240     memcpy(protocol, filename, len);
 241     protocol[len] = '\0';
 242     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 243         if (drv1->protocol_name &&
 244             !strcmp(drv1->protocol_name, protocol))
 245             return drv1;
 246     }
 247     return NULL;
 248 }
 249
 250 /* XXX: force raw format if block or character device ? It would
 251    simplify the BSD case */
 252 static BlockDriver *find_image_format(const char *filename)
 253 {
 254     int ret, score, score_max;
 255     BlockDriver *drv1, *drv;
 256     uint8_t buf[2048];
 257     BlockDriverState *bs;
 258
 259     /* detect host devices. By convention, /dev/cdrom[N] is always
 260        recognized as a host CDROM */
 261     if (strstart(filename, "/dev/cdrom", NULL))
 262         return &bdrv_host_device;
 263 #ifdef _WIN32
 264     if (is_windows_drive(filename))
 265         return &bdrv_host_device;
 266 #else
 267     {
 268         struct stat st;
 269         if (stat(filename, &st) >= 0 &&
 270             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
 271             return &bdrv_host_device;
 272         }
 273     }
 274 #endif
 275
 276     drv = find_protocol(filename);
 277     /* no need to test disk image formats for vvfat */
 278     if (drv == &bdrv_vvfat)
 279         return drv;
 280
 281     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
 282     if (ret < 0)
 283         return NULL;
 284     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
 285     bdrv_delete(bs);
 286     if (ret < 0) {
 287         return NULL;
 288     }
 289
 290     score_max = 0;
 291     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 292         if (drv1->bdrv_probe) {
 293             score = drv1->bdrv_probe(buf, ret, filename);
 294             if (score > score_max) {
 295                 score_max = score;
 296                 drv = drv1;
 297             }
 298         }
 299     }
 300     return drv;
 301 }
 302
 303 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 304 {
 305     BlockDriverState *bs;
 306     int ret;
 307
 308     bs = bdrv_new("");
 309     if (!bs)
 310         return -ENOMEM;
 311     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
 312     if (ret < 0) {
 313         bdrv_delete(bs);
 314         return ret;
 315     }
 316     *pbs = bs;
 317     return 0;
 318 }
 319
 320 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
 321 {
 322     return bdrv_open2(bs, filename, flags, NULL);
 323 }
 324
 325 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 326                BlockDriver *drv)
 327 {
 328     int ret, open_flags;
 329     char tmp_filename[PATH_MAX];
 330     char backing_filename[PATH_MAX];
 331
 332     bs->read_only = 0;
 333     bs->is_temporary = 0;
 334     bs->encrypted = 0;
 335
 336     if (flags & BDRV_O_SNAPSHOT) {
 337         BlockDriverState *bs1;
 338         int64_t total_size;
 339
 340         /* if snapshot, we create a temporary backing file and open it
 341            instead of opening 'filename' directly */
 342
 343         /* if there is a backing file, use it */
 344         bs1 = bdrv_new("");
 345         if (!bs1) {
 346             return -ENOMEM;
 347         }
 348         if (bdrv_open(bs1, filename, 0) < 0) {
 349             bdrv_delete(bs1);
 350             return -1;
 351         }
 352         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
 353         bdrv_delete(bs1);
 354
 355         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 356         realpath(filename, backing_filename);
 357         if (bdrv_create(&bdrv_qcow2, tmp_filename,
 358                         total_size, backing_filename, 0) < 0) {
 359             return -1;
 360         }
 361         filename = tmp_filename;
 362         bs->is_temporary = 1;
 363     }
 364
 365     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 366     if (flags & BDRV_O_FILE) {
 367         drv = find_protocol(filename);
 368         if (!drv)
 369             return -ENOENT;
 370     } else {
 371         if (!drv) {
 372             drv = find_image_format(filename);
 373             if (!drv)
 374                 return -1;
 375         }
 376     }
 377     bs->drv = drv;
 378     bs->opaque = qemu_mallocz(drv->instance_size);
 379     if (bs->opaque == NULL && drv->instance_size > 0)
 380         return -1;
 381     /* Note: for compatibility, we open disk image files as RDWR, and
 382        RDONLY as fallback */
 383     if (!(flags & BDRV_O_FILE))
 384         open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
 385     else
 386         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
 387     ret = drv->bdrv_open(bs, filename, open_flags);
 388     if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
 389         ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
 390         bs->read_only = 1;
 391     }
 392     if (ret < 0) {
 393         qemu_free(bs->opaque);
 394         bs->opaque = NULL;
 395         bs->drv = NULL;
 396         return ret;
 397     }
 398     if (drv->bdrv_getlength) {
 399         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 400     }
 401 #ifndef _WIN32
 402     if (bs->is_temporary) {
 403         unlink(filename);
 404     }
 405 #endif
 406     if (bs->backing_file[0] != '\0') {
 407         /* if there is a backing file, use it */
 408         bs->backing_hd = bdrv_new("");
 409         if (!bs->backing_hd) {
 410         fail:
 411             bdrv_close(bs);
 412             return -ENOMEM;
 413         }
 414         path_combine(backing_filename, sizeof(backing_filename),
 415                      filename, bs->backing_file);
 416         if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
 417             goto fail;
 418     }
 419
 420     /* call the change callback */
 421     bs->media_changed = 1;
 422     if (bs->change_cb)
 423         bs->change_cb(bs->change_opaque);
 424
 425     return 0;
 426 }
 427
 428 void bdrv_close(BlockDriverState *bs)
 429 {
 430     if (bs->drv) {
 431         if (bs->backing_hd)
 432             bdrv_delete(bs->backing_hd);
 433         bs->drv->bdrv_close(bs);
 434         qemu_free(bs->opaque);
 435 #ifdef _WIN32
 436         if (bs->is_temporary) {
 437             unlink(bs->filename);
 438         }
 439 #endif
 440         bs->opaque = NULL;
 441         bs->drv = NULL;
 442
 443         /* call the change callback */
 444         bs->media_changed = 1;
 445         if (bs->change_cb)
 446             bs->change_cb(bs->change_opaque);
 447     }
 448 }
 449
 450 void bdrv_delete(BlockDriverState *bs)
 451 {
 452     /* XXX: remove the driver list */
 453     bdrv_close(bs);
 454     qemu_free(bs);
 455 }
 456
 457 /* commit COW file into the raw image */
 458 int bdrv_commit(BlockDriverState *bs)
 459 {
 460     BlockDriver *drv = bs->drv;
 461     int64_t i, total_sectors;
 462     int n, j;
 463     unsigned char sector[512];
 464
 465     if (!drv)
 466         return -ENOMEDIUM;
 467
 468     if (bs->read_only) {
 469         return -EACCES;
 470     }
 471
 472     if (!bs->backing_hd) {
 473         return -ENOTSUP;
 474     }
 475
 476     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 477     for (i = 0; i < total_sectors;) {
 478         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 479             for(j = 0; j < n; j++) {
 480                 if (bdrv_read(bs, i, sector, 1) != 0) {
 481                     return -EIO;
 482                 }
 483
 484                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 485                     return -EIO;
 486                 }
 487                 i++;
 488             }
 489         } else {
 490             i += n;
 491         }
 492     }
 493
 494     if (drv->bdrv_make_empty)
 495         return drv->bdrv_make_empty(bs);
 496
 497     return 0;
 498 }
 499
 500 /* return < 0 if error. See bdrv_write() for the return codes */
 501 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 502               uint8_t *buf, int nb_sectors)
 503 {
 504     BlockDriver *drv = bs->drv;
 505
 506     if (!drv)
 507         return -ENOMEDIUM;
 508
 509     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 510             memcpy(buf, bs->boot_sector_data, 512);
 511         sector_num++;
 512         nb_sectors--;
 513         buf += 512;
 514         if (nb_sectors == 0)
 515             return 0;
 516     }
 517     if (drv->bdrv_pread) {
 518         int ret, len;
 519         len = nb_sectors * 512;
 520         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 521         if (ret < 0)
 522             return ret;
 523         else if (ret != len)
 524             return -EINVAL;
 525         else {
 526             bs->rd_bytes += (unsigned) len;
 527             bs->rd_ops ++;
 528             return 0;
 529         }
 530     } else {
 531         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 532     }
 533 }
 534
 535 /* Return < 0 if error. Important errors are:
 536   -EIO         generic I/O error (may happen for all errors)
 537   -ENOMEDIUM   No media inserted.
 538   -EINVAL      Invalid sector number or nb_sectors
 539   -EACCES      Trying to write a read-only device
 540 */
 541 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 542                const uint8_t *buf, int nb_sectors)
 543 {
 544     BlockDriver *drv = bs->drv;
 545     if (!bs->drv)
 546         return -ENOMEDIUM;
 547     if (bs->read_only)
 548         return -EACCES;
 549     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 550         memcpy(bs->boot_sector_data, buf, 512);
 551     }
 552     if (drv->bdrv_pwrite) {
 553         int ret, len;
 554         len = nb_sectors * 512;
 555         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 556         if (ret < 0)
 557             return ret;
 558         else if (ret != len)
 559             return -EIO;
 560         else {
 561             bs->wr_bytes += (unsigned) len;
 562             bs->wr_ops ++;
 563             return 0;
 564         }
 565     } else {
 566         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 567     }
 568 }
 569
 570 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 571                          uint8_t *buf, int count1)
 572 {
 573     uint8_t tmp_buf[SECTOR_SIZE];
 574     int len, nb_sectors, count;
 575     int64_t sector_num;
 576
 577     count = count1;
 578     /* first read to align to sector start */
 579     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 580     if (len > count)
 581         len = count;
 582     sector_num = offset >> SECTOR_BITS;
 583     if (len > 0) {
 584         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 585             return -EIO;
 586         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 587         count -= len;
 588         if (count == 0)
 589             return count1;
 590         sector_num++;
 591         buf += len;
 592     }
 593
 594     /* read the sectors "in place" */
 595     nb_sectors = count >> SECTOR_BITS;
 596     if (nb_sectors > 0) {
 597         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 598             return -EIO;
 599         sector_num += nb_sectors;
 600         len = nb_sectors << SECTOR_BITS;
 601         buf += len;
 602         count -= len;
 603     }
 604
 605     /* add data from the last sector */
 606     if (count > 0) {
 607         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 608             return -EIO;
 609         memcpy(buf, tmp_buf, count);
 610     }
 611     return count1;
 612 }
 613
 614 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 615                           const uint8_t *buf, int count1)
 616 {
 617     uint8_t tmp_buf[SECTOR_SIZE];
 618     int len, nb_sectors, count;
 619     int64_t sector_num;
 620
 621     count = count1;
 622     /* first write to align to sector start */
 623     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 624     if (len > count)
 625         len = count;
 626     sector_num = offset >> SECTOR_BITS;
 627     if (len > 0) {
 628         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 629             return -EIO;
 630         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 631         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 632             return -EIO;
 633         count -= len;
 634         if (count == 0)
 635             return count1;
 636         sector_num++;
 637         buf += len;
 638     }
 639
 640     /* write the sectors "in place" */
 641     nb_sectors = count >> SECTOR_BITS;
 642     if (nb_sectors > 0) {
 643         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 644             return -EIO;
 645         sector_num += nb_sectors;
 646         len = nb_sectors << SECTOR_BITS;
 647         buf += len;
 648         count -= len;
 649     }
 650
 651     /* add data from the last sector */
 652     if (count > 0) {
 653         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 654             return -EIO;
 655         memcpy(tmp_buf, buf, count);
 656         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 657             return -EIO;
 658     }
 659     return count1;
 660 }
 661
 662 /**
 663  * Read with byte offsets (needed only for file protocols)
 664  */
 665 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 666                void *buf1, int count1)
 667 {
 668     BlockDriver *drv = bs->drv;
 669
 670     if (!drv)
 671         return -ENOMEDIUM;
 672     if (!drv->bdrv_pread)
 673         return bdrv_pread_em(bs, offset, buf1, count1);
 674     return drv->bdrv_pread(bs, offset, buf1, count1);
 675 }
 676
 677 /**
 678  * Write with byte offsets (needed only for file protocols)
 679  */
 680 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 681                 const void *buf1, int count1)
 682 {
 683     BlockDriver *drv = bs->drv;
 684
 685     if (!drv)
 686         return -ENOMEDIUM;
 687     if (!drv->bdrv_pwrite)
 688         return bdrv_pwrite_em(bs, offset, buf1, count1);
 689     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 690 }
 691
 692 /**
 693  * Truncate file to 'offset' bytes (needed only for file protocols)
 694  */
 695 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 696 {
 697     BlockDriver *drv = bs->drv;
 698     if (!drv)
 699         return -ENOMEDIUM;
 700     if (!drv->bdrv_truncate)
 701         return -ENOTSUP;
 702     return drv->bdrv_truncate(bs, offset);
 703 }
 704
 705 /**
 706  * Length of a file in bytes. Return < 0 if error or unknown.
 707  */
 708 int64_t bdrv_getlength(BlockDriverState *bs)
 709 {
 710     BlockDriver *drv = bs->drv;
 711     if (!drv)
 712         return -ENOMEDIUM;
 713     if (!drv->bdrv_getlength) {
 714         /* legacy mode */
 715         return bs->total_sectors * SECTOR_SIZE;
 716     }
 717     return drv->bdrv_getlength(bs);
 718 }
 719
 720 /* return 0 as number of sectors if no device present or error */
 721 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 722 {
 723     int64_t length;
 724     length = bdrv_getlength(bs);
 725     if (length < 0)
 726         length = 0;
 727     else
 728         length = length >> SECTOR_BITS;
 729     *nb_sectors_ptr = length;
 730 }
 731
 732 /* force a given boot sector. */
 733 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 734 {
 735     bs->boot_sector_enabled = 1;
 736     if (size > 512)
 737         size = 512;
 738     memcpy(bs->boot_sector_data, data, size);
 739     memset(bs->boot_sector_data + size, 0, 512 - size);
 740 }
 741
 742 struct partition {
 743         uint8_t boot_ind;               /* 0x80 - active */
 744         uint8_t head;           /* starting head */
 745         uint8_t sector;         /* starting sector */
 746         uint8_t cyl;            /* starting cylinder */
 747         uint8_t sys_ind;                /* What partition type */
 748         uint8_t end_head;               /* end head */
 749         uint8_t end_sector;     /* end sector */
 750         uint8_t end_cyl;                /* end cylinder */
 751         uint32_t start_sect;    /* starting sector counting from 0 */
 752         uint32_t nr_sects;              /* nr of sectors in partition */
 753 } __attribute__((packed));
 754
 755 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
 756 static int guess_disk_lchs(BlockDriverState *bs,
 757                            int *pcylinders, int *pheads, int *psectors)
 758 {
 759     uint8_t *buf;
 760     int ret, i, heads, sectors, cylinders;
 761     struct partition *p;
 762     uint32_t nr_sects;
 763     int64_t nb_sectors;
 764
 765     buf = qemu_memalign(512, 512);
 766     if (buf == NULL)
 767         return -1;
 768
 769     bdrv_get_geometry(bs, &nb_sectors);
 770
 771     ret = bdrv_read(bs, 0, buf, 1);
 772     if (ret < 0)
 773         return -1;
 774     /* test msdos magic */
 775     if (buf[510] != 0x55 || buf[511] != 0xaa) {
 776         qemu_free(buf);
 777         return -1;
 778     }
 779     for(i = 0; i < 4; i++) {
 780         p = ((struct partition *)(buf + 0x1be)) + i;
 781         nr_sects = le32_to_cpu(p->nr_sects);
 782         if (nr_sects && p->end_head) {
 783             /* We make the assumption that the partition terminates on
 784                a cylinder boundary */
 785             heads = p->end_head + 1;
 786             sectors = p->end_sector & 63;
 787             if (sectors == 0)
 788                 continue;
 789             cylinders = nb_sectors / (heads * sectors);
 790             if (cylinders < 1 || cylinders > 16383)
 791                 continue;
 792             *pheads = heads;
 793             *psectors = sectors;
 794             *pcylinders = cylinders;
 795 #if 0
 796             printf("guessed geometry: LCHS=%d %d %d\n",
 797                    cylinders, heads, sectors);
 798 #endif
 799             qemu_free(buf);
 800             return 0;
 801         }
 802     }
 803     qemu_free(buf);
 804     return -1;
 805 }
 806
 807 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
 808 {
 809     int translation, lba_detected = 0;
 810     int cylinders, heads, secs;
 811     int64_t nb_sectors;
 812
 813     /* if a geometry hint is available, use it */
 814     bdrv_get_geometry(bs, &nb_sectors);
 815     bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
 816     translation = bdrv_get_translation_hint(bs);
 817     if (cylinders != 0) {
 818         *pcyls = cylinders;
 819         *pheads = heads;
 820         *psecs = secs;
 821     } else {
 822         if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
 823             if (heads > 16) {
 824                 /* if heads > 16, it means that a BIOS LBA
 825                    translation was active, so the default
 826                    hardware geometry is OK */
 827                 lba_detected = 1;
 828                 goto default_geometry;
 829             } else {
 830                 *pcyls = cylinders;
 831                 *pheads = heads;
 832                 *psecs = secs;
 833                 /* disable any translation to be in sync with
 834                    the logical geometry */
 835                 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
 836                     bdrv_set_translation_hint(bs,
 837                                               BIOS_ATA_TRANSLATION_NONE);
 838                 }
 839             }
 840         } else {
 841         default_geometry:
 842             /* if no geometry, use a standard physical disk geometry */
 843             cylinders = nb_sectors / (16 * 63);
 844
 845             if (cylinders > 16383)
 846                 cylinders = 16383;
 847             else if (cylinders < 2)
 848                 cylinders = 2;
 849             *pcyls = cylinders;
 850             *pheads = 16;
 851             *psecs = 63;
 852             if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
 853                 if ((*pcyls * *pheads) <= 131072) {
 854                     bdrv_set_translation_hint(bs,
 855                                               BIOS_ATA_TRANSLATION_LARGE);
 856                 } else {
 857                     bdrv_set_translation_hint(bs,
 858                                               BIOS_ATA_TRANSLATION_LBA);
 859                 }
 860             }
 861         }
 862         bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
 863     }
 864 }
 865
 866 void bdrv_set_geometry_hint(BlockDriverState *bs,
 867                             int cyls, int heads, int secs)
 868 {
 869     bs->cyls = cyls;
 870     bs->heads = heads;
 871     bs->secs = secs;
 872 }
 873
 874 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 875 {
 876     bs->type = type;
 877     bs->removable = ((type == BDRV_TYPE_CDROM ||
 878                       type == BDRV_TYPE_FLOPPY));
 879 }
 880
 881 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 882 {
 883     bs->translation = translation;
 884 }
 885
 886 void bdrv_get_geometry_hint(BlockDriverState *bs,
 887                             int *pcyls, int *pheads, int *psecs)
 888 {
 889     *pcyls = bs->cyls;
 890     *pheads = bs->heads;
 891     *psecs = bs->secs;
 892 }
 893
 894 int bdrv_get_type_hint(BlockDriverState *bs)
 895 {
 896     return bs->type;
 897 }
 898
 899 int bdrv_get_translation_hint(BlockDriverState *bs)
 900 {
 901     return bs->translation;
 902 }
 903
 904 int bdrv_is_removable(BlockDriverState *bs)
 905 {
 906     return bs->removable;
 907 }
 908
 909 int bdrv_is_read_only(BlockDriverState *bs)
 910 {
 911     return bs->read_only;
 912 }
 913
 914 int bdrv_is_sg(BlockDriverState *bs)
 915 {
 916     return bs->sg;
 917 }
 918
 919 /* XXX: no longer used */
 920 void bdrv_set_change_cb(BlockDriverState *bs,
 921                         void (*change_cb)(void *opaque), void *opaque)
 922 {
 923     bs->change_cb = change_cb;
 924     bs->change_opaque = opaque;
 925 }
 926
 927 int bdrv_is_encrypted(BlockDriverState *bs)
 928 {
 929     if (bs->backing_hd && bs->backing_hd->encrypted)
 930         return 1;
 931     return bs->encrypted;
 932 }
 933
 934 int bdrv_set_key(BlockDriverState *bs, const char *key)
 935 {
 936     int ret;
 937     if (bs->backing_hd && bs->backing_hd->encrypted) {
 938         ret = bdrv_set_key(bs->backing_hd, key);
 939         if (ret < 0)
 940             return ret;
 941         if (!bs->encrypted)
 942             return 0;
 943     }
 944     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 945         return -1;
 946     return bs->drv->bdrv_set_key(bs, key);
 947 }
 948
 949 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 950 {
 951     if (!bs->drv) {
 952         buf[0] = '\0';
 953     } else {
 954         pstrcpy(buf, buf_size, bs->drv->format_name);
 955     }
 956 }
 957
 958 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 959                          void *opaque)
 960 {
 961     BlockDriver *drv;
 962
 963     for (drv = first_drv; drv != NULL; drv = drv->next) {
 964         it(opaque, drv->format_name);
 965     }
 966 }
 967
 968 BlockDriverState *bdrv_find(const char *name)
 969 {
 970     BlockDriverState *bs;
 971
 972     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 973         if (!strcmp(name, bs->device_name))
 974             return bs;
 975     }
 976     return NULL;
 977 }
 978
 979 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 980 {
 981     BlockDriverState *bs;
 982
 983     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 984         it(opaque, bs->device_name);
 985     }
 986 }
 987
 988 const char *bdrv_get_device_name(BlockDriverState *bs)
 989 {
 990     return bs->device_name;
 991 }
 992
 993 void bdrv_flush(BlockDriverState *bs)
 994 {
 995     if (bs->drv->bdrv_flush)
 996         bs->drv->bdrv_flush(bs);
 997     if (bs->backing_hd)
 998         bdrv_flush(bs->backing_hd);
 999 }
1000
1001 void bdrv_iterate_writeable(void (*it)(BlockDriverState *bs))
1002 {
1003     BlockDriverState *bs;
1004
1005     for (bs = bdrv_first; bs != NULL; bs = bs->next)
1006         if (bs->drv && !bdrv_is_read_only(bs) &&
1007             (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1008             it(bs);
1009 }
1010
1011 void bdrv_flush_all(void)
1012 {
1013     bdrv_iterate_writeable(bdrv_flush);
1014 }
1015
1016 #ifndef QEMU_IMG
1017 void bdrv_info(void)
1018 {
1019     BlockDriverState *bs;
1020
1021     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1022         term_printf("%s:", bs->device_name);
1023         term_printf(" type=");
1024         switch(bs->type) {
1025         case BDRV_TYPE_HD:
1026             term_printf("hd");
1027             break;
1028         case BDRV_TYPE_CDROM:
1029             term_printf("cdrom");
1030             break;
1031         case BDRV_TYPE_FLOPPY:
1032             term_printf("floppy");
1033             break;
1034         }
1035         term_printf(" removable=%d", bs->removable);
1036         if (bs->removable) {
1037             term_printf(" locked=%d", bs->locked);
1038         }
1039         if (bs->drv) {
1040             term_printf(" file=");
1041             term_print_filename(bs->filename);
1042             if (bs->backing_file[0] != '\0') {
1043                 term_printf(" backing_file=");
1044                 term_print_filename(bs->backing_file);
1045             }
1046             term_printf(" ro=%d", bs->read_only);
1047             term_printf(" drv=%s", bs->drv->format_name);
1048             if (bs->encrypted)
1049                 term_printf(" encrypted");
1050         } else {
1051             term_printf(" [not inserted]");
1052         }
1053         term_printf("\n");
1054     }
1055 }
1056
1057 /* The "info blockstats" command. */
1058 void bdrv_info_stats (void)
1059 {
1060     BlockDriverState *bs;
1061
1062     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1063         term_printf ("%s:"
1064                      " rd_bytes=%" PRIu64
1065                      " wr_bytes=%" PRIu64
1066                      " rd_operations=%" PRIu64
1067                      " wr_operations=%" PRIu64
1068                      "\n",
1069                      bs->device_name,
1070                      bs->rd_bytes, bs->wr_bytes,
1071                      bs->rd_ops, bs->wr_ops);
1072     }
1073 }
1074 #endif
1075
1076 void bdrv_get_backing_filename(BlockDriverState *bs,
1077                                char *filename, int filename_size)
1078 {
1079     if (!bs->backing_hd) {
1080         pstrcpy(filename, filename_size, "");
1081     } else {
1082         pstrcpy(filename, filename_size, bs->backing_file);
1083     }
1084 }
1085
1086 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1087                           const uint8_t *buf, int nb_sectors)
1088 {
1089     BlockDriver *drv = bs->drv;
1090     if (!drv)
1091         return -ENOMEDIUM;
1092     if (!drv->bdrv_write_compressed)
1093         return -ENOTSUP;
1094     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1095 }
1096
1097 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1098 {
1099     BlockDriver *drv = bs->drv;
1100     if (!drv)
1101         return -ENOMEDIUM;
1102     if (!drv->bdrv_get_info)
1103         return -ENOTSUP;
1104     memset(bdi, 0, sizeof(*bdi));
1105     return drv->bdrv_get_info(bs, bdi);
1106 }
1107
1108 /**************************************************************/
1109 /* handling of snapshots */
1110
1111 int bdrv_snapshot_create(BlockDriverState *bs,
1112                          QEMUSnapshotInfo *sn_info)
1113 {
1114     BlockDriver *drv = bs->drv;
1115     if (!drv)
1116         return -ENOMEDIUM;
1117     if (!drv->bdrv_snapshot_create)
1118         return -ENOTSUP;
1119     return drv->bdrv_snapshot_create(bs, sn_info);
1120 }
1121
1122 int bdrv_snapshot_goto(BlockDriverState *bs,
1123                        const char *snapshot_id)
1124 {
1125     BlockDriver *drv = bs->drv;
1126     if (!drv)
1127         return -ENOMEDIUM;
1128     if (!drv->bdrv_snapshot_goto)
1129         return -ENOTSUP;
1130     return drv->bdrv_snapshot_goto(bs, snapshot_id);
1131 }
1132
1133 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1134 {
1135     BlockDriver *drv = bs->drv;
1136     if (!drv)
1137         return -ENOMEDIUM;
1138     if (!drv->bdrv_snapshot_delete)
1139         return -ENOTSUP;
1140     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1141 }
1142
1143 int bdrv_snapshot_list(BlockDriverState *bs,
1144                        QEMUSnapshotInfo **psn_info)
1145 {
1146     BlockDriver *drv = bs->drv;
1147     if (!drv)
1148         return -ENOMEDIUM;
1149     if (!drv->bdrv_snapshot_list)
1150         return -ENOTSUP;
1151     return drv->bdrv_snapshot_list(bs, psn_info);
1152 }
1153
1154 #define NB_SUFFIXES 4
1155
1156 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1157 {
1158     static const char suffixes[NB_SUFFIXES] = "KMGT";
1159     int64_t base;
1160     int i;
1161
1162     if (size <= 999) {
1163         snprintf(buf, buf_size, "%" PRId64, size);
1164     } else {
1165         base = 1024;
1166         for(i = 0; i < NB_SUFFIXES; i++) {
1167             if (size < (10 * base)) {
1168                 snprintf(buf, buf_size, "%0.1f%c",
1169                          (double)size / base,
1170                          suffixes[i]);
1171                 break;
1172             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1173                 snprintf(buf, buf_size, "%" PRId64 "%c",
1174                          ((size + (base >> 1)) / base),
1175                          suffixes[i]);
1176                 break;
1177             }
1178             base = base * 1024;
1179         }
1180     }
1181     return buf;
1182 }
1183
1184 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1185 {
1186     char buf1[128], date_buf[128], clock_buf[128];
1187 #ifdef _WIN32
1188     struct tm *ptm;
1189 #else
1190     struct tm tm;
1191 #endif
1192     time_t ti;
1193     int64_t secs;
1194
1195     if (!sn) {
1196         snprintf(buf, buf_size,
1197                  "%-10s%-20s%7s%20s%15s",
1198                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1199     } else {
1200         ti = sn->date_sec;
1201 #ifdef _WIN32
1202         ptm = localtime(&ti);
1203         strftime(date_buf, sizeof(date_buf),
1204                  "%Y-%m-%d %H:%M:%S", ptm);
1205 #else
1206         localtime_r(&ti, &tm);
1207         strftime(date_buf, sizeof(date_buf),
1208                  "%Y-%m-%d %H:%M:%S", &tm);
1209 #endif
1210         secs = sn->vm_clock_nsec / 1000000000;
1211         snprintf(clock_buf, sizeof(clock_buf),
1212                  "%02d:%02d:%02d.%03d",
1213                  (int)(secs / 3600),
1214                  (int)((secs / 60) % 60),
1215                  (int)(secs % 60),
1216                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1217         snprintf(buf, buf_size,
1218                  "%-10s%-20s%7s%20s%15s",
1219                  sn->id_str, sn->name,
1220                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1221                  date_buf,
1222                  clock_buf);
1223     }
1224     return buf;
1225 }
1226
1227
1228 /**************************************************************/
1229 /* async I/Os */
1230
1231 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1232                                 uint8_t *buf, int nb_sectors,
1233                                 BlockDriverCompletionFunc *cb, void *opaque)
1234 {
1235     BlockDriver *drv = bs->drv;
1236     BlockDriverAIOCB *ret;
1237
1238     if (!drv)
1239         return NULL;
1240
1241     /* XXX: we assume that nb_sectors == 0 is suppored by the async read */
1242     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1243         memcpy(buf, bs->boot_sector_data, 512);
1244         sector_num++;
1245         nb_sectors--;
1246         buf += 512;
1247     }
1248
1249     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1250
1251     if (ret) {
1252         /* Update stats even though technically transfer has not happened. */
1253         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1254         bs->rd_ops ++;
1255     }
1256
1257     return ret;
1258 }
1259
1260 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1261                                  const uint8_t *buf, int nb_sectors,
1262                                  BlockDriverCompletionFunc *cb, void *opaque)
1263 {
1264     BlockDriver *drv = bs->drv;
1265     BlockDriverAIOCB *ret;
1266
1267     if (!drv)
1268         return NULL;
1269     if (bs->read_only)
1270         return NULL;
1271     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1272         memcpy(bs->boot_sector_data, buf, 512);
1273     }
1274
1275     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1276
1277     if (ret) {
1278         /* Update stats even though technically transfer has not happened. */
1279         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1280         bs->wr_ops ++;
1281     }
1282
1283     return ret;
1284 }
1285
1286 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1287 {
1288     BlockDriver *drv = acb->bs->drv;
1289
1290     drv->bdrv_aio_cancel(acb);
1291 }
1292
1293
1294 /**************************************************************/
1295 /* async block device emulation */
1296
1297 #ifdef QEMU_IMG
1298 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1299         int64_t sector_num, uint8_t *buf, int nb_sectors,
1300         BlockDriverCompletionFunc *cb, void *opaque)
1301 {
1302     int ret;
1303     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1304     cb(opaque, ret);
1305     return NULL;
1306 }
1307
1308 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1309         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1310         BlockDriverCompletionFunc *cb, void *opaque)
1311 {
1312     int ret;
1313     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1314     cb(opaque, ret);
1315     return NULL;
1316 }
1317
1318 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb)
1319 {
1320 }
1321 #else
1322 static void bdrv_aio_bh_cb(void *opaque)
1323 {
1324     BlockDriverAIOCBSync *acb = opaque;
1325     acb->common.cb(acb->common.opaque, acb->ret);
1326     qemu_aio_release(acb);
1327 }
1328
1329 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1330         int64_t sector_num, uint8_t *buf, int nb_sectors,
1331         BlockDriverCompletionFunc *cb, void *opaque)
1332 {
1333     BlockDriverAIOCBSync *acb;
1334     int ret;
1335
1336     acb = qemu_aio_get(bs, cb, opaque);
1337     if (!acb->bh)
1338         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1339     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1340     acb->ret = ret;
1341     qemu_bh_schedule(acb->bh);
1342     return &acb->common;
1343 }
1344
1345 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1346         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1347         BlockDriverCompletionFunc *cb, void *opaque)
1348 {
1349     BlockDriverAIOCBSync *acb;
1350     int ret;
1351
1352     acb = qemu_aio_get(bs, cb, opaque);
1353     if (!acb->bh)
1354         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1355     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1356     acb->ret = ret;
1357     qemu_bh_schedule(acb->bh);
1358     return &acb->common;
1359 }
1360
1361 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1362 {
1363     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1364     qemu_bh_cancel(acb->bh);
1365     qemu_aio_release(acb);
1366 }
1367 #endif /* !QEMU_IMG */
1368
1369 /**************************************************************/
1370 /* sync block device emulation */
1371
1372 static void bdrv_rw_em_cb(void *opaque, int ret)
1373 {
1374     *(int *)opaque = ret;
1375 }
1376
1377 #define NOT_DONE 0x7fffffff
1378
1379 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1380                         uint8_t *buf, int nb_sectors)
1381 {
1382     int async_ret;
1383     BlockDriverAIOCB *acb;
1384
1385     async_ret = NOT_DONE;
1386     qemu_aio_wait_start();
1387     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1388                         bdrv_rw_em_cb, &async_ret);
1389     if (acb == NULL) {
1390         qemu_aio_wait_end();
1391         return -1;
1392     }
1393     while (async_ret == NOT_DONE) {
1394         qemu_aio_wait();
1395     }
1396     qemu_aio_wait_end();
1397     return async_ret;
1398 }
1399
1400 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1401                          const uint8_t *buf, int nb_sectors)
1402 {
1403     int async_ret;
1404     BlockDriverAIOCB *acb;
1405
1406     async_ret = NOT_DONE;
1407     qemu_aio_wait_start();
1408     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1409                          bdrv_rw_em_cb, &async_ret);
1410     if (acb == NULL) {
1411         qemu_aio_wait_end();
1412         return -1;
1413     }
1414     while (async_ret == NOT_DONE) {
1415         qemu_aio_wait();
1416     }
1417     qemu_aio_wait_end();
1418     return async_ret;
1419 }
1420
1421 void bdrv_init(void)
1422 {
1423     bdrv_register(&bdrv_raw);
1424     bdrv_register(&bdrv_host_device);
1425 #ifndef _WIN32
1426     bdrv_register(&bdrv_cow);
1427 #endif
1428     bdrv_register(&bdrv_qcow);
1429     bdrv_register(&bdrv_vmdk);
1430     bdrv_register(&bdrv_cloop);
1431     bdrv_register(&bdrv_dmg);
1432     bdrv_register(&bdrv_bochs);
1433     bdrv_register(&bdrv_vpc);
1434     bdrv_register(&bdrv_vvfat);
1435     bdrv_register(&bdrv_qcow2);
1436     bdrv_register(&bdrv_parallels);
1437 }
1438
1439 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1440                    void *opaque)
1441 {
1442     BlockDriver *drv;
1443     BlockDriverAIOCB *acb;
1444
1445     drv = bs->drv;
1446     if (drv->free_aiocb) {
1447         acb = drv->free_aiocb;
1448         drv->free_aiocb = acb->next;
1449     } else {
1450         acb = qemu_mallocz(drv->aiocb_size);
1451         if (!acb)
1452             return NULL;
1453     }
1454     acb->bs = bs;
1455     acb->cb = cb;
1456     acb->opaque = opaque;
1457     return acb;
1458 }
1459
1460 void qemu_aio_release(void *p)
1461 {
1462     BlockDriverAIOCB *acb = p;
1463     BlockDriver *drv = acb->bs->drv;
1464     acb->next = drv->free_aiocb;
1465     drv->free_aiocb = acb;
1466 }
1467
1468 /**************************************************************/
1469 /* removable device support */
1470
1471 /**
1472  * Return TRUE if the media is present
1473  */
1474 int bdrv_is_inserted(BlockDriverState *bs)
1475 {
1476     BlockDriver *drv = bs->drv;
1477     int ret;
1478     if (!drv)
1479         return 0;
1480     if (!drv->bdrv_is_inserted)
1481         return 1;
1482     ret = drv->bdrv_is_inserted(bs);
1483     return ret;
1484 }
1485
1486 /**
1487  * Return TRUE if the media changed since the last call to this
1488  * function. It is currently only used for floppy disks
1489  */
1490 int bdrv_media_changed(BlockDriverState *bs)
1491 {
1492     BlockDriver *drv = bs->drv;
1493     int ret;
1494
1495     if (!drv || !drv->bdrv_media_changed)
1496         ret = -ENOTSUP;
1497     else
1498         ret = drv->bdrv_media_changed(bs);
1499     if (ret == -ENOTSUP)
1500         ret = bs->media_changed;
1501     bs->media_changed = 0;
1502     return ret;
1503 }
1504
1505 /**
1506  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1507  */
1508 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1509 {
1510     BlockDriver *drv = bs->drv;
1511     int ret;
1512
1513     if (!drv || !drv->bdrv_eject) {
1514         ret = -ENOTSUP;
1515     } else {
1516         ret = drv->bdrv_eject(bs, eject_flag);
1517     }
1518     if (ret == -ENOTSUP) {
1519         if (eject_flag)
1520             bdrv_close(bs);
1521     }
1522 }
1523
1524 int bdrv_is_locked(BlockDriverState *bs)
1525 {
1526     return bs->locked;
1527 }
1528
1529 /**
1530  * Lock or unlock the media (if it is locked, the user won't be able
1531  * to eject it manually).
1532  */
1533 void bdrv_set_locked(BlockDriverState *bs, int locked)
1534 {
1535     BlockDriver *drv = bs->drv;
1536
1537     bs->locked = locked;
1538     if (drv && drv->bdrv_set_locked) {
1539         drv->bdrv_set_locked(bs, locked);
1540     }
1541 }
1542
1543 /* needed for generic scsi interface */
1544
1545 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1546 {
1547     BlockDriver *drv = bs->drv;
1548
1549     if (drv && drv->bdrv_ioctl)
1550         return drv->bdrv_ioctl(bs, req, buf);
1551     return -ENOTSUP;
1552 }