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