block.c

   1 /*
   2  * QEMU System Emulator block driver
   3  *
   4  * Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu-common.h"
  25 #ifndef QEMU_IMG
  26 #include "console.h"
  27 #endif
  28 #include "block_int.h"
  29
  30 #ifdef _BSD
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/queue.h>
  35 #include <sys/disk.h>
  36 #endif
  37
  38 #define SECTOR_BITS 9
  39 #define SECTOR_SIZE (1 << SECTOR_BITS)
  40
  41 typedef struct BlockDriverAIOCBSync {
  42     BlockDriverAIOCB common;
  43     QEMUBH *bh;
  44     int ret;
  45 } BlockDriverAIOCBSync;
  46
  47 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
  48         int64_t sector_num, uint8_t *buf, int nb_sectors,
  49         BlockDriverCompletionFunc *cb, void *opaque);
  50 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
  51         int64_t sector_num, const uint8_t *buf, int nb_sectors,
  52         BlockDriverCompletionFunc *cb, void *opaque);
  53 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
  54 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
  55                         uint8_t *buf, int nb_sectors);
  56 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
  57                          const uint8_t *buf, int nb_sectors);
  58
  59 BlockDriverState *bdrv_first;
  60 static BlockDriver *first_drv;
  61
  62 int path_is_absolute(const char *path)
  63 {
  64     const char *p;
  65 #ifdef _WIN32
  66     /* specific case for names like: "\\.\d:" */
  67     if (*path == '/' || *path == '\\')
  68         return 1;
  69 #endif
  70     p = strchr(path, ':');
  71     if (p)
  72         p++;
  73     else
  74         p = path;
  75 #ifdef _WIN32
  76     return (*p == '/' || *p == '\\');
  77 #else
  78     return (*p == '/');
  79 #endif
  80 }
  81
  82 /* if filename is absolute, just copy it to dest. Otherwise, build a
  83    path to it by considering it is relative to base_path. URL are
  84    supported. */
  85 void path_combine(char *dest, int dest_size,
  86                   const char *base_path,
  87                   const char *filename)
  88 {
  89     const char *p, *p1;
  90     int len;
  91
  92     if (dest_size <= 0)
  93         return;
  94     if (path_is_absolute(filename)) {
  95         pstrcpy(dest, dest_size, filename);
  96     } else {
  97         p = strchr(base_path, ':');
  98         if (p)
  99             p++;
 100         else
 101             p = base_path;
 102         p1 = strrchr(base_path, '/');
 103 #ifdef _WIN32
 104         {
 105             const char *p2;
 106             p2 = strrchr(base_path, '\\');
 107             if (!p1 || p2 > p1)
 108                 p1 = p2;
 109         }
 110 #endif
 111         if (p1)
 112             p1++;
 113         else
 114             p1 = base_path;
 115         if (p1 > p)
 116             p = p1;
 117         len = p - base_path;
 118         if (len > dest_size - 1)
 119             len = dest_size - 1;
 120         memcpy(dest, base_path, len);
 121         dest[len] = '\0';
 122         pstrcat(dest, dest_size, filename);
 123     }
 124 }
 125
 126
 127 static void bdrv_register(BlockDriver *bdrv)
 128 {
 129     if (!bdrv->bdrv_aio_read) {
 130         /* add AIO emulation layer */
 131         bdrv->bdrv_aio_read = bdrv_aio_read_em;
 132         bdrv->bdrv_aio_write = bdrv_aio_write_em;
 133         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
 134         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
 135     } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
 136         /* add synchronous IO emulation layer */
 137         bdrv->bdrv_read = bdrv_read_em;
 138         bdrv->bdrv_write = bdrv_write_em;
 139     }
 140     bdrv->next = first_drv;
 141     first_drv = bdrv;
 142 }
 143
 144 /* create a new block device (by default it is empty) */
 145 BlockDriverState *bdrv_new(const char *device_name)
 146 {
 147     BlockDriverState **pbs, *bs;
 148
 149     bs = qemu_mallocz(sizeof(BlockDriverState));
 150     if(!bs)
 151         return NULL;
 152     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
 153     if (device_name[0] != '\0') {
 154         /* insert at the end */
 155         pbs = &bdrv_first;
 156         while (*pbs != NULL)
 157             pbs = &(*pbs)->next;
 158         *pbs = bs;
 159     }
 160     return bs;
 161 }
 162
 163 BlockDriver *bdrv_find_format(const char *format_name)
 164 {
 165     BlockDriver *drv1;
 166     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 167         if (!strcmp(drv1->format_name, format_name))
 168             return drv1;
 169     }
 170     return NULL;
 171 }
 172
 173 int bdrv_create(BlockDriver *drv,
 174                 const char *filename, int64_t size_in_sectors,
 175                 const char *backing_file, int flags)
 176 {
 177     if (!drv->bdrv_create)
 178         return -ENOTSUP;
 179     return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
 180 }
 181
 182 #ifdef _WIN32
 183 void get_tmp_filename(char *filename, int size)
 184 {
 185     char temp_dir[MAX_PATH];
 186
 187     GetTempPath(MAX_PATH, temp_dir);
 188     GetTempFileName(temp_dir, "qem", 0, filename);
 189 }
 190 #else
 191 void get_tmp_filename(char *filename, int size)
 192 {
 193     int fd;
 194     /* XXX: race condition possible */
 195     pstrcpy(filename, size, "/tmp/vl.XXXXXX");
 196     fd = mkstemp(filename);
 197     close(fd);
 198 }
 199 #endif
 200
 201 #ifdef _WIN32
 202 static int is_windows_drive_prefix(const char *filename)
 203 {
 204     return (((filename[0] >= 'a' && filename[0] <= 'z') ||
 205              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 206             filename[1] == ':');
 207 }
 208
 209 static int is_windows_drive(const char *filename)
 210 {
 211     if (is_windows_drive_prefix(filename) &&
 212         filename[2] == '\0')
 213         return 1;
 214     if (strstart(filename, "\\\\.\\", NULL) ||
 215         strstart(filename, "//./", NULL))
 216         return 1;
 217     return 0;
 218 }
 219 #endif
 220
 221 static BlockDriver *find_protocol(const char *filename)
 222 {
 223     BlockDriver *drv1;
 224     char protocol[128];
 225     int len;
 226     const char *p;
 227
 228 #ifdef _WIN32
 229     if (is_windows_drive(filename) ||
 230         is_windows_drive_prefix(filename))
 231         return &bdrv_raw;
 232 #endif
 233     p = strchr(filename, ':');
 234     if (!p)
 235         return &bdrv_raw;
 236     len = p - filename;
 237     if (len > sizeof(protocol) - 1)
 238         len = sizeof(protocol) - 1;
 239     memcpy(protocol, filename, len);
 240     protocol[len] = '\0';
 241     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 242         if (drv1->protocol_name &&
 243             !strcmp(drv1->protocol_name, protocol))
 244             return drv1;
 245     }
 246     return NULL;
 247 }
 248
 249 /* XXX: force raw format if block or character device ? It would
 250    simplify the BSD case */
 251 static BlockDriver *find_image_format(const char *filename)
 252 {
 253     int ret, score, score_max;
 254     BlockDriver *drv1, *drv;
 255     uint8_t buf[2048];
 256     BlockDriverState *bs;
 257
 258     /* detect host devices. By convention, /dev/cdrom[N] is always
 259        recognized as a host CDROM */
 260     if (strstart(filename, "/dev/cdrom", NULL))
 261         return &bdrv_host_device;
 262 #ifdef _WIN32
 263     if (is_windows_drive(filename))
 264         return &bdrv_host_device;
 265 #else
 266     {
 267         struct stat st;
 268         if (stat(filename, &st) >= 0 &&
 269             (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
 270             return &bdrv_host_device;
 271         }
 272     }
 273 #endif
 274
 275     drv = find_protocol(filename);
 276     /* no need to test disk image formats for vvfat */
 277     if (drv == &bdrv_vvfat)
 278         return drv;
 279
 280     ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
 281     if (ret < 0)
 282         return NULL;
 283     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
 284     bdrv_delete(bs);
 285     if (ret < 0) {
 286         return NULL;
 287     }
 288
 289     score_max = 0;
 290     for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
 291         if (drv1->bdrv_probe) {
 292             score = drv1->bdrv_probe(buf, ret, filename);
 293             if (score > score_max) {
 294                 score_max = score;
 295                 drv = drv1;
 296             }
 297         }
 298     }
 299     return drv;
 300 }
 301
 302 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 303 {
 304     BlockDriverState *bs;
 305     int ret;
 306
 307     bs = bdrv_new("");
 308     if (!bs)
 309         return -ENOMEM;
 310     ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
 311     if (ret < 0) {
 312         bdrv_delete(bs);
 313         return ret;
 314     }
 315     *pbs = bs;
 316     return 0;
 317 }
 318
 319 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
 320 {
 321     return bdrv_open2(bs, filename, flags, NULL);
 322 }
 323
 324 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
 325                BlockDriver *drv)
 326 {
 327     int ret, open_flags;
 328     char tmp_filename[PATH_MAX];
 329     char backing_filename[PATH_MAX];
 330
 331     bs->read_only = 0;
 332     bs->is_temporary = 0;
 333     bs->encrypted = 0;
 334
 335     if (flags & BDRV_O_SNAPSHOT) {
 336         BlockDriverState *bs1;
 337         int64_t total_size;
 338
 339         /* if snapshot, we create a temporary backing file and open it
 340            instead of opening 'filename' directly */
 341
 342         /* if there is a backing file, use it */
 343         bs1 = bdrv_new("");
 344         if (!bs1) {
 345             return -ENOMEM;
 346         }
 347         if (bdrv_open(bs1, filename, 0) < 0) {
 348             bdrv_delete(bs1);
 349             return -1;
 350         }
 351         total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
 352         bdrv_delete(bs1);
 353
 354         get_tmp_filename(tmp_filename, sizeof(tmp_filename));
 355         realpath(filename, backing_filename);
 356         if (bdrv_create(&bdrv_qcow2, tmp_filename,
 357                         total_size, backing_filename, 0) < 0) {
 358             return -1;
 359         }
 360         filename = tmp_filename;
 361         bs->is_temporary = 1;
 362     }
 363
 364     pstrcpy(bs->filename, sizeof(bs->filename), filename);
 365     if (flags & BDRV_O_FILE) {
 366         drv = find_protocol(filename);
 367         if (!drv)
 368             return -ENOENT;
 369     } else {
 370         if (!drv) {
 371             drv = find_image_format(filename);
 372             if (!drv)
 373                 return -1;
 374         }
 375     }
 376     bs->drv = drv;
 377     bs->opaque = qemu_mallocz(drv->instance_size);
 378     if (bs->opaque == NULL && drv->instance_size > 0)
 379         return -1;
 380     /* Note: for compatibility, we open disk image files as RDWR, and
 381        RDONLY as fallback */
 382     if (!(flags & BDRV_O_FILE))
 383         open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
 384     else
 385         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
 386     ret = drv->bdrv_open(bs, filename, open_flags);
 387     if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
 388         ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
 389         bs->read_only = 1;
 390     }
 391     if (ret < 0) {
 392         qemu_free(bs->opaque);
 393         bs->opaque = NULL;
 394         bs->drv = NULL;
 395         return ret;
 396     }
 397     if (drv->bdrv_getlength) {
 398         bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 399     }
 400 #ifndef _WIN32
 401     if (bs->is_temporary) {
 402         unlink(filename);
 403     }
 404 #endif
 405     if (bs->backing_file[0] != '\0') {
 406         /* if there is a backing file, use it */
 407         bs->backing_hd = bdrv_new("");
 408         if (!bs->backing_hd) {
 409         fail:
 410             bdrv_close(bs);
 411             return -ENOMEM;
 412         }
 413         path_combine(backing_filename, sizeof(backing_filename),
 414                      filename, bs->backing_file);
 415         if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
 416             goto fail;
 417     }
 418
 419     /* call the change callback */
 420     bs->media_changed = 1;
 421     if (bs->change_cb)
 422         bs->change_cb(bs->change_opaque);
 423
 424     return 0;
 425 }
 426
 427 void bdrv_close(BlockDriverState *bs)
 428 {
 429     if (bs->drv) {
 430         if (bs->backing_hd)
 431             bdrv_delete(bs->backing_hd);
 432         bs->drv->bdrv_close(bs);
 433         qemu_free(bs->opaque);
 434 #ifdef _WIN32
 435         if (bs->is_temporary) {
 436             unlink(bs->filename);
 437         }
 438 #endif
 439         bs->opaque = NULL;
 440         bs->drv = NULL;
 441
 442         /* call the change callback */
 443         bs->media_changed = 1;
 444         if (bs->change_cb)
 445             bs->change_cb(bs->change_opaque);
 446     }
 447 }
 448
 449 void bdrv_delete(BlockDriverState *bs)
 450 {
 451     /* XXX: remove the driver list */
 452     bdrv_close(bs);
 453     qemu_free(bs);
 454 }
 455
 456 /* commit COW file into the raw image */
 457 int bdrv_commit(BlockDriverState *bs)
 458 {
 459     BlockDriver *drv = bs->drv;
 460     int64_t i, total_sectors;
 461     int n, j;
 462     unsigned char sector[512];
 463
 464     if (!drv)
 465         return -ENOMEDIUM;
 466
 467     if (bs->read_only) {
 468         return -EACCES;
 469     }
 470
 471     if (!bs->backing_hd) {
 472         return -ENOTSUP;
 473     }
 474
 475     total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
 476     for (i = 0; i < total_sectors;) {
 477         if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
 478             for(j = 0; j < n; j++) {
 479                 if (bdrv_read(bs, i, sector, 1) != 0) {
 480                     return -EIO;
 481                 }
 482
 483                 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
 484                     return -EIO;
 485                 }
 486                 i++;
 487             }
 488         } else {
 489             i += n;
 490         }
 491     }
 492
 493     if (drv->bdrv_make_empty)
 494         return drv->bdrv_make_empty(bs);
 495
 496     return 0;
 497 }
 498
 499 /* return < 0 if error. See bdrv_write() for the return codes */
 500 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
 501               uint8_t *buf, int nb_sectors)
 502 {
 503     BlockDriver *drv = bs->drv;
 504
 505     if (!drv)
 506         return -ENOMEDIUM;
 507
 508     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 509             memcpy(buf, bs->boot_sector_data, 512);
 510         sector_num++;
 511         nb_sectors--;
 512         buf += 512;
 513         if (nb_sectors == 0)
 514             return 0;
 515     }
 516     if (drv->bdrv_pread) {
 517         int ret, len;
 518         len = nb_sectors * 512;
 519         ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
 520         if (ret < 0)
 521             return ret;
 522         else if (ret != len)
 523             return -EINVAL;
 524         else {
 525             bs->rd_bytes += (unsigned) len;
 526             bs->rd_ops ++;
 527             return 0;
 528         }
 529     } else {
 530         return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
 531     }
 532 }
 533
 534 /* Return < 0 if error. Important errors are:
 535   -EIO         generic I/O error (may happen for all errors)
 536   -ENOMEDIUM   No media inserted.
 537   -EINVAL      Invalid sector number or nb_sectors
 538   -EACCES      Trying to write a read-only device
 539 */
 540 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
 541                const uint8_t *buf, int nb_sectors)
 542 {
 543     BlockDriver *drv = bs->drv;
 544     if (!bs->drv)
 545         return -ENOMEDIUM;
 546     if (bs->read_only)
 547         return -EACCES;
 548     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
 549         memcpy(bs->boot_sector_data, buf, 512);
 550     }
 551     if (drv->bdrv_pwrite) {
 552         int ret, len;
 553         len = nb_sectors * 512;
 554         ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
 555         if (ret < 0)
 556             return ret;
 557         else if (ret != len)
 558             return -EIO;
 559         else {
 560             bs->wr_bytes += (unsigned) len;
 561             bs->wr_ops ++;
 562             return 0;
 563         }
 564     } else {
 565         return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
 566     }
 567 }
 568
 569 static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
 570                          uint8_t *buf, int count1)
 571 {
 572     uint8_t tmp_buf[SECTOR_SIZE];
 573     int len, nb_sectors, count;
 574     int64_t sector_num;
 575
 576     count = count1;
 577     /* first read to align to sector start */
 578     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 579     if (len > count)
 580         len = count;
 581     sector_num = offset >> SECTOR_BITS;
 582     if (len > 0) {
 583         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 584             return -EIO;
 585         memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
 586         count -= len;
 587         if (count == 0)
 588             return count1;
 589         sector_num++;
 590         buf += len;
 591     }
 592
 593     /* read the sectors "in place" */
 594     nb_sectors = count >> SECTOR_BITS;
 595     if (nb_sectors > 0) {
 596         if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
 597             return -EIO;
 598         sector_num += nb_sectors;
 599         len = nb_sectors << SECTOR_BITS;
 600         buf += len;
 601         count -= len;
 602     }
 603
 604     /* add data from the last sector */
 605     if (count > 0) {
 606         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 607             return -EIO;
 608         memcpy(buf, tmp_buf, count);
 609     }
 610     return count1;
 611 }
 612
 613 static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
 614                           const uint8_t *buf, int count1)
 615 {
 616     uint8_t tmp_buf[SECTOR_SIZE];
 617     int len, nb_sectors, count;
 618     int64_t sector_num;
 619
 620     count = count1;
 621     /* first write to align to sector start */
 622     len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
 623     if (len > count)
 624         len = count;
 625     sector_num = offset >> SECTOR_BITS;
 626     if (len > 0) {
 627         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 628             return -EIO;
 629         memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
 630         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 631             return -EIO;
 632         count -= len;
 633         if (count == 0)
 634             return count1;
 635         sector_num++;
 636         buf += len;
 637     }
 638
 639     /* write the sectors "in place" */
 640     nb_sectors = count >> SECTOR_BITS;
 641     if (nb_sectors > 0) {
 642         if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
 643             return -EIO;
 644         sector_num += nb_sectors;
 645         len = nb_sectors << SECTOR_BITS;
 646         buf += len;
 647         count -= len;
 648     }
 649
 650     /* add data from the last sector */
 651     if (count > 0) {
 652         if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
 653             return -EIO;
 654         memcpy(tmp_buf, buf, count);
 655         if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
 656             return -EIO;
 657     }
 658     return count1;
 659 }
 660
 661 /**
 662  * Read with byte offsets (needed only for file protocols)
 663  */
 664 int bdrv_pread(BlockDriverState *bs, int64_t offset,
 665                void *buf1, int count1)
 666 {
 667     BlockDriver *drv = bs->drv;
 668
 669     if (!drv)
 670         return -ENOMEDIUM;
 671     if (!drv->bdrv_pread)
 672         return bdrv_pread_em(bs, offset, buf1, count1);
 673     return drv->bdrv_pread(bs, offset, buf1, count1);
 674 }
 675
 676 /**
 677  * Write with byte offsets (needed only for file protocols)
 678  */
 679 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
 680                 const void *buf1, int count1)
 681 {
 682     BlockDriver *drv = bs->drv;
 683
 684     if (!drv)
 685         return -ENOMEDIUM;
 686     if (!drv->bdrv_pwrite)
 687         return bdrv_pwrite_em(bs, offset, buf1, count1);
 688     return drv->bdrv_pwrite(bs, offset, buf1, count1);
 689 }
 690
 691 /**
 692  * Truncate file to 'offset' bytes (needed only for file protocols)
 693  */
 694 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
 695 {
 696     BlockDriver *drv = bs->drv;
 697     if (!drv)
 698         return -ENOMEDIUM;
 699     if (!drv->bdrv_truncate)
 700         return -ENOTSUP;
 701     return drv->bdrv_truncate(bs, offset);
 702 }
 703
 704 /**
 705  * Length of a file in bytes. Return < 0 if error or unknown.
 706  */
 707 int64_t bdrv_getlength(BlockDriverState *bs)
 708 {
 709     BlockDriver *drv = bs->drv;
 710     if (!drv)
 711         return -ENOMEDIUM;
 712     if (!drv->bdrv_getlength) {
 713         /* legacy mode */
 714         return bs->total_sectors * SECTOR_SIZE;
 715     }
 716     return drv->bdrv_getlength(bs);
 717 }
 718
 719 /* return 0 as number of sectors if no device present or error */
 720 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 721 {
 722     int64_t length;
 723     length = bdrv_getlength(bs);
 724     if (length < 0)
 725         length = 0;
 726     else
 727         length = length >> SECTOR_BITS;
 728     *nb_sectors_ptr = length;
 729 }
 730
 731 /* force a given boot sector. */
 732 void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
 733 {
 734     bs->boot_sector_enabled = 1;
 735     if (size > 512)
 736         size = 512;
 737     memcpy(bs->boot_sector_data, data, size);
 738     memset(bs->boot_sector_data + size, 0, 512 - size);
 739 }
 740
 741 void bdrv_set_geometry_hint(BlockDriverState *bs,
 742                             int cyls, int heads, int secs)
 743 {
 744     bs->cyls = cyls;
 745     bs->heads = heads;
 746     bs->secs = secs;
 747 }
 748
 749 void bdrv_set_type_hint(BlockDriverState *bs, int type)
 750 {
 751     bs->type = type;
 752     bs->removable = ((type == BDRV_TYPE_CDROM ||
 753                       type == BDRV_TYPE_FLOPPY));
 754 }
 755
 756 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
 757 {
 758     bs->translation = translation;
 759 }
 760
 761 void bdrv_get_geometry_hint(BlockDriverState *bs,
 762                             int *pcyls, int *pheads, int *psecs)
 763 {
 764     *pcyls = bs->cyls;
 765     *pheads = bs->heads;
 766     *psecs = bs->secs;
 767 }
 768
 769 int bdrv_get_type_hint(BlockDriverState *bs)
 770 {
 771     return bs->type;
 772 }
 773
 774 int bdrv_get_translation_hint(BlockDriverState *bs)
 775 {
 776     return bs->translation;
 777 }
 778
 779 int bdrv_is_removable(BlockDriverState *bs)
 780 {
 781     return bs->removable;
 782 }
 783
 784 int bdrv_is_read_only(BlockDriverState *bs)
 785 {
 786     return bs->read_only;
 787 }
 788
 789 int bdrv_is_sg(BlockDriverState *bs)
 790 {
 791     return bs->sg;
 792 }
 793
 794 /* XXX: no longer used */
 795 void bdrv_set_change_cb(BlockDriverState *bs,
 796                         void (*change_cb)(void *opaque), void *opaque)
 797 {
 798     bs->change_cb = change_cb;
 799     bs->change_opaque = opaque;
 800 }
 801
 802 int bdrv_is_encrypted(BlockDriverState *bs)
 803 {
 804     if (bs->backing_hd && bs->backing_hd->encrypted)
 805         return 1;
 806     return bs->encrypted;
 807 }
 808
 809 int bdrv_set_key(BlockDriverState *bs, const char *key)
 810 {
 811     int ret;
 812     if (bs->backing_hd && bs->backing_hd->encrypted) {
 813         ret = bdrv_set_key(bs->backing_hd, key);
 814         if (ret < 0)
 815             return ret;
 816         if (!bs->encrypted)
 817             return 0;
 818     }
 819     if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
 820         return -1;
 821     return bs->drv->bdrv_set_key(bs, key);
 822 }
 823
 824 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
 825 {
 826     if (!bs->drv) {
 827         buf[0] = '\0';
 828     } else {
 829         pstrcpy(buf, buf_size, bs->drv->format_name);
 830     }
 831 }
 832
 833 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 834                          void *opaque)
 835 {
 836     BlockDriver *drv;
 837
 838     for (drv = first_drv; drv != NULL; drv = drv->next) {
 839         it(opaque, drv->format_name);
 840     }
 841 }
 842
 843 BlockDriverState *bdrv_find(const char *name)
 844 {
 845     BlockDriverState *bs;
 846
 847     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 848         if (!strcmp(name, bs->device_name))
 849             return bs;
 850     }
 851     return NULL;
 852 }
 853
 854 void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
 855 {
 856     BlockDriverState *bs;
 857
 858     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 859         it(opaque, bs->device_name);
 860     }
 861 }
 862
 863 const char *bdrv_get_device_name(BlockDriverState *bs)
 864 {
 865     return bs->device_name;
 866 }
 867
 868 void bdrv_flush(BlockDriverState *bs)
 869 {
 870     if (bs->drv->bdrv_flush)
 871         bs->drv->bdrv_flush(bs);
 872     if (bs->backing_hd)
 873         bdrv_flush(bs->backing_hd);
 874 }
 875
 876 #ifndef QEMU_IMG
 877 void bdrv_info(void)
 878 {
 879     BlockDriverState *bs;
 880
 881     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 882         term_printf("%s:", bs->device_name);
 883         term_printf(" type=");
 884         switch(bs->type) {
 885         case BDRV_TYPE_HD:
 886             term_printf("hd");
 887             break;
 888         case BDRV_TYPE_CDROM:
 889             term_printf("cdrom");
 890             break;
 891         case BDRV_TYPE_FLOPPY:
 892             term_printf("floppy");
 893             break;
 894         }
 895         term_printf(" removable=%d", bs->removable);
 896         if (bs->removable) {
 897             term_printf(" locked=%d", bs->locked);
 898         }
 899         if (bs->drv) {
 900             term_printf(" file=");
 901             term_print_filename(bs->filename);
 902             if (bs->backing_file[0] != '\0') {
 903                 term_printf(" backing_file=");
 904                 term_print_filename(bs->backing_file);
 905             }
 906             term_printf(" ro=%d", bs->read_only);
 907             term_printf(" drv=%s", bs->drv->format_name);
 908             if (bs->encrypted)
 909                 term_printf(" encrypted");
 910         } else {
 911             term_printf(" [not inserted]");
 912         }
 913         term_printf("\n");
 914     }
 915 }
 916
 917 /* The "info blockstats" command. */
 918 void bdrv_info_stats (void)
 919 {
 920     BlockDriverState *bs;
 921
 922     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
 923         term_printf ("%s:"
 924                      " rd_bytes=%" PRIu64
 925                      " wr_bytes=%" PRIu64
 926                      " rd_operations=%" PRIu64
 927                      " wr_operations=%" PRIu64
 928                      "\n",
 929                      bs->device_name,
 930                      bs->rd_bytes, bs->wr_bytes,
 931                      bs->rd_ops, bs->wr_ops);
 932     }
 933 }
 934 #endif
 935
 936 void bdrv_get_backing_filename(BlockDriverState *bs,
 937                                char *filename, int filename_size)
 938 {
 939     if (!bs->backing_hd) {
 940         pstrcpy(filename, filename_size, "");
 941     } else {
 942         pstrcpy(filename, filename_size, bs->backing_file);
 943     }
 944 }
 945
 946 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
 947                           const uint8_t *buf, int nb_sectors)
 948 {
 949     BlockDriver *drv = bs->drv;
 950     if (!drv)
 951         return -ENOMEDIUM;
 952     if (!drv->bdrv_write_compressed)
 953         return -ENOTSUP;
 954     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
 955 }
 956
 957 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 958 {
 959     BlockDriver *drv = bs->drv;
 960     if (!drv)
 961         return -ENOMEDIUM;
 962     if (!drv->bdrv_get_info)
 963         return -ENOTSUP;
 964     memset(bdi, 0, sizeof(*bdi));
 965     return drv->bdrv_get_info(bs, bdi);
 966 }
 967
 968 /**************************************************************/
 969 /* handling of snapshots */
 970
 971 int bdrv_snapshot_create(BlockDriverState *bs,
 972                          QEMUSnapshotInfo *sn_info)
 973 {
 974     BlockDriver *drv = bs->drv;
 975     if (!drv)
 976         return -ENOMEDIUM;
 977     if (!drv->bdrv_snapshot_create)
 978         return -ENOTSUP;
 979     return drv->bdrv_snapshot_create(bs, sn_info);
 980 }
 981
 982 int bdrv_snapshot_goto(BlockDriverState *bs,
 983                        const char *snapshot_id)
 984 {
 985     BlockDriver *drv = bs->drv;
 986     if (!drv)
 987         return -ENOMEDIUM;
 988     if (!drv->bdrv_snapshot_goto)
 989         return -ENOTSUP;
 990     return drv->bdrv_snapshot_goto(bs, snapshot_id);
 991 }
 992
 993 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
 994 {
 995     BlockDriver *drv = bs->drv;
 996     if (!drv)
 997         return -ENOMEDIUM;
 998     if (!drv->bdrv_snapshot_delete)
 999         return -ENOTSUP;
1000     return drv->bdrv_snapshot_delete(bs, snapshot_id);
1001 }
1002
1003 int bdrv_snapshot_list(BlockDriverState *bs,
1004                        QEMUSnapshotInfo **psn_info)
1005 {
1006     BlockDriver *drv = bs->drv;
1007     if (!drv)
1008         return -ENOMEDIUM;
1009     if (!drv->bdrv_snapshot_list)
1010         return -ENOTSUP;
1011     return drv->bdrv_snapshot_list(bs, psn_info);
1012 }
1013
1014 #define NB_SUFFIXES 4
1015
1016 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1017 {
1018     static const char suffixes[NB_SUFFIXES] = "KMGT";
1019     int64_t base;
1020     int i;
1021
1022     if (size <= 999) {
1023         snprintf(buf, buf_size, "%" PRId64, size);
1024     } else {
1025         base = 1024;
1026         for(i = 0; i < NB_SUFFIXES; i++) {
1027             if (size < (10 * base)) {
1028                 snprintf(buf, buf_size, "%0.1f%c",
1029                          (double)size / base,
1030                          suffixes[i]);
1031                 break;
1032             } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1033                 snprintf(buf, buf_size, "%" PRId64 "%c",
1034                          ((size + (base >> 1)) / base),
1035                          suffixes[i]);
1036                 break;
1037             }
1038             base = base * 1024;
1039         }
1040     }
1041     return buf;
1042 }
1043
1044 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1045 {
1046     char buf1[128], date_buf[128], clock_buf[128];
1047 #ifdef _WIN32
1048     struct tm *ptm;
1049 #else
1050     struct tm tm;
1051 #endif
1052     time_t ti;
1053     int64_t secs;
1054
1055     if (!sn) {
1056         snprintf(buf, buf_size,
1057                  "%-10s%-20s%7s%20s%15s",
1058                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1059     } else {
1060         ti = sn->date_sec;
1061 #ifdef _WIN32
1062         ptm = localtime(&ti);
1063         strftime(date_buf, sizeof(date_buf),
1064                  "%Y-%m-%d %H:%M:%S", ptm);
1065 #else
1066         localtime_r(&ti, &tm);
1067         strftime(date_buf, sizeof(date_buf),
1068                  "%Y-%m-%d %H:%M:%S", &tm);
1069 #endif
1070         secs = sn->vm_clock_nsec / 1000000000;
1071         snprintf(clock_buf, sizeof(clock_buf),
1072                  "%02d:%02d:%02d.%03d",
1073                  (int)(secs / 3600),
1074                  (int)((secs / 60) % 60),
1075                  (int)(secs % 60),
1076                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
1077         snprintf(buf, buf_size,
1078                  "%-10s%-20s%7s%20s%15s",
1079                  sn->id_str, sn->name,
1080                  get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1081                  date_buf,
1082                  clock_buf);
1083     }
1084     return buf;
1085 }
1086
1087
1088 /**************************************************************/
1089 /* async I/Os */
1090
1091 BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
1092                                 uint8_t *buf, int nb_sectors,
1093                                 BlockDriverCompletionFunc *cb, void *opaque)
1094 {
1095     BlockDriver *drv = bs->drv;
1096     BlockDriverAIOCB *ret;
1097
1098     if (!drv)
1099         return NULL;
1100
1101     /* XXX: we assume that nb_sectors == 0 is suppored by the async read */
1102     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1103         memcpy(buf, bs->boot_sector_data, 512);
1104         sector_num++;
1105         nb_sectors--;
1106         buf += 512;
1107     }
1108
1109     ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
1110
1111     if (ret) {
1112         /* Update stats even though technically transfer has not happened. */
1113         bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1114         bs->rd_ops ++;
1115     }
1116
1117     return ret;
1118 }
1119
1120 BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
1121                                  const uint8_t *buf, int nb_sectors,
1122                                  BlockDriverCompletionFunc *cb, void *opaque)
1123 {
1124     BlockDriver *drv = bs->drv;
1125     BlockDriverAIOCB *ret;
1126
1127     if (!drv)
1128         return NULL;
1129     if (bs->read_only)
1130         return NULL;
1131     if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
1132         memcpy(bs->boot_sector_data, buf, 512);
1133     }
1134
1135     ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
1136
1137     if (ret) {
1138         /* Update stats even though technically transfer has not happened. */
1139         bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
1140         bs->wr_ops ++;
1141     }
1142
1143     return ret;
1144 }
1145
1146 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1147 {
1148     BlockDriver *drv = acb->bs->drv;
1149
1150     drv->bdrv_aio_cancel(acb);
1151 }
1152
1153
1154 /**************************************************************/
1155 /* async block device emulation */
1156
1157 #ifdef QEMU_IMG
1158 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1159         int64_t sector_num, uint8_t *buf, int nb_sectors,
1160         BlockDriverCompletionFunc *cb, void *opaque)
1161 {
1162     int ret;
1163     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1164     cb(opaque, ret);
1165     return NULL;
1166 }
1167
1168 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1169         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1170         BlockDriverCompletionFunc *cb, void *opaque)
1171 {
1172     int ret;
1173     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1174     cb(opaque, ret);
1175     return NULL;
1176 }
1177
1178 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb)
1179 {
1180 }
1181 #else
1182 static void bdrv_aio_bh_cb(void *opaque)
1183 {
1184     BlockDriverAIOCBSync *acb = opaque;
1185     acb->common.cb(acb->common.opaque, acb->ret);
1186     qemu_aio_release(acb);
1187 }
1188
1189 static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
1190         int64_t sector_num, uint8_t *buf, int nb_sectors,
1191         BlockDriverCompletionFunc *cb, void *opaque)
1192 {
1193     BlockDriverAIOCBSync *acb;
1194     int ret;
1195
1196     acb = qemu_aio_get(bs, cb, opaque);
1197     if (!acb->bh)
1198         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1199     ret = bdrv_read(bs, sector_num, buf, nb_sectors);
1200     acb->ret = ret;
1201     qemu_bh_schedule(acb->bh);
1202     return &acb->common;
1203 }
1204
1205 static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
1206         int64_t sector_num, const uint8_t *buf, int nb_sectors,
1207         BlockDriverCompletionFunc *cb, void *opaque)
1208 {
1209     BlockDriverAIOCBSync *acb;
1210     int ret;
1211
1212     acb = qemu_aio_get(bs, cb, opaque);
1213     if (!acb->bh)
1214         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1215     ret = bdrv_write(bs, sector_num, buf, nb_sectors);
1216     acb->ret = ret;
1217     qemu_bh_schedule(acb->bh);
1218     return &acb->common;
1219 }
1220
1221 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1222 {
1223     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1224     qemu_bh_cancel(acb->bh);
1225     qemu_aio_release(acb);
1226 }
1227 #endif /* !QEMU_IMG */
1228
1229 /**************************************************************/
1230 /* sync block device emulation */
1231
1232 static void bdrv_rw_em_cb(void *opaque, int ret)
1233 {
1234     *(int *)opaque = ret;
1235 }
1236
1237 #define NOT_DONE 0x7fffffff
1238
1239 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1240                         uint8_t *buf, int nb_sectors)
1241 {
1242     int async_ret;
1243     BlockDriverAIOCB *acb;
1244
1245     async_ret = NOT_DONE;
1246     qemu_aio_wait_start();
1247     acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
1248                         bdrv_rw_em_cb, &async_ret);
1249     if (acb == NULL) {
1250         qemu_aio_wait_end();
1251         return -1;
1252     }
1253     while (async_ret == NOT_DONE) {
1254         qemu_aio_wait();
1255     }
1256     qemu_aio_wait_end();
1257     return async_ret;
1258 }
1259
1260 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1261                          const uint8_t *buf, int nb_sectors)
1262 {
1263     int async_ret;
1264     BlockDriverAIOCB *acb;
1265
1266     async_ret = NOT_DONE;
1267     qemu_aio_wait_start();
1268     acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
1269                          bdrv_rw_em_cb, &async_ret);
1270     if (acb == NULL) {
1271         qemu_aio_wait_end();
1272         return -1;
1273     }
1274     while (async_ret == NOT_DONE) {
1275         qemu_aio_wait();
1276     }
1277     qemu_aio_wait_end();
1278     return async_ret;
1279 }
1280
1281 void bdrv_init(void)
1282 {
1283     bdrv_register(&bdrv_raw);
1284     bdrv_register(&bdrv_host_device);
1285 #ifndef _WIN32
1286     bdrv_register(&bdrv_cow);
1287 #endif
1288     bdrv_register(&bdrv_qcow);
1289     bdrv_register(&bdrv_vmdk);
1290     bdrv_register(&bdrv_cloop);
1291     bdrv_register(&bdrv_dmg);
1292     bdrv_register(&bdrv_bochs);
1293     bdrv_register(&bdrv_vpc);
1294     bdrv_register(&bdrv_vvfat);
1295     bdrv_register(&bdrv_qcow2);
1296     bdrv_register(&bdrv_parallels);
1297 }
1298
1299 void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
1300                    void *opaque)
1301 {
1302     BlockDriver *drv;
1303     BlockDriverAIOCB *acb;
1304
1305     drv = bs->drv;
1306     if (drv->free_aiocb) {
1307         acb = drv->free_aiocb;
1308         drv->free_aiocb = acb->next;
1309     } else {
1310         acb = qemu_mallocz(drv->aiocb_size);
1311         if (!acb)
1312             return NULL;
1313     }
1314     acb->bs = bs;
1315     acb->cb = cb;
1316     acb->opaque = opaque;
1317     return acb;
1318 }
1319
1320 void qemu_aio_release(void *p)
1321 {
1322     BlockDriverAIOCB *acb = p;
1323     BlockDriver *drv = acb->bs->drv;
1324     acb->next = drv->free_aiocb;
1325     drv->free_aiocb = acb;
1326 }
1327
1328 /**************************************************************/
1329 /* removable device support */
1330
1331 /**
1332  * Return TRUE if the media is present
1333  */
1334 int bdrv_is_inserted(BlockDriverState *bs)
1335 {
1336     BlockDriver *drv = bs->drv;
1337     int ret;
1338     if (!drv)
1339         return 0;
1340     if (!drv->bdrv_is_inserted)
1341         return 1;
1342     ret = drv->bdrv_is_inserted(bs);
1343     return ret;
1344 }
1345
1346 /**
1347  * Return TRUE if the media changed since the last call to this
1348  * function. It is currently only used for floppy disks
1349  */
1350 int bdrv_media_changed(BlockDriverState *bs)
1351 {
1352     BlockDriver *drv = bs->drv;
1353     int ret;
1354
1355     if (!drv || !drv->bdrv_media_changed)
1356         ret = -ENOTSUP;
1357     else
1358         ret = drv->bdrv_media_changed(bs);
1359     if (ret == -ENOTSUP)
1360         ret = bs->media_changed;
1361     bs->media_changed = 0;
1362     return ret;
1363 }
1364
1365 /**
1366  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1367  */
1368 void bdrv_eject(BlockDriverState *bs, int eject_flag)
1369 {
1370     BlockDriver *drv = bs->drv;
1371     int ret;
1372
1373     if (!drv || !drv->bdrv_eject) {
1374         ret = -ENOTSUP;
1375     } else {
1376         ret = drv->bdrv_eject(bs, eject_flag);
1377     }
1378     if (ret == -ENOTSUP) {
1379         if (eject_flag)
1380             bdrv_close(bs);
1381     }
1382 }
1383
1384 int bdrv_is_locked(BlockDriverState *bs)
1385 {
1386     return bs->locked;
1387 }
1388
1389 /**
1390  * Lock or unlock the media (if it is locked, the user won't be able
1391  * to eject it manually).
1392  */
1393 void bdrv_set_locked(BlockDriverState *bs, int locked)
1394 {
1395     BlockDriver *drv = bs->drv;
1396
1397     bs->locked = locked;
1398     if (drv && drv->bdrv_set_locked) {
1399         drv->bdrv_set_locked(bs, locked);
1400     }
1401 }
1402
1403 /* needed for generic scsi interface */
1404
1405 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1406 {
1407     BlockDriver *drv = bs->drv;
1408
1409     if (drv && drv->bdrv_ioctl)
1410         return drv->bdrv_ioctl(bs, req, buf);
1411     return -ENOTSUP;
1412 }