blockdev.c

   1 /*
   2  * QEMU host block devices
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or
   7  * later.  See the COPYING file in the top-level directory.
   8  */
   9
  10 #include "block.h"
  11 #include "blockdev.h"
  12 #include "monitor.h"
  13 #include "qerror.h"
  14 #include "qemu-option.h"
  15 #include "qemu-config.h"
  16 #include "sysemu.h"
  17 #include "hw/qdev.h"
  18 #include "block_int.h"
  19
  20 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
  21
  22 static const char *const if_name[IF_COUNT] = {
  23     [IF_NONE] = "none",
  24     [IF_IDE] = "ide",
  25     [IF_SCSI] = "scsi",
  26     [IF_FLOPPY] = "floppy",
  27     [IF_PFLASH] = "pflash",
  28     [IF_MTD] = "mtd",
  29     [IF_SD] = "sd",
  30     [IF_VIRTIO] = "virtio",
  31     [IF_XEN] = "xen",
  32 };
  33
  34 static const int if_max_devs[IF_COUNT] = {
  35     /*
  36      * Do not change these numbers!  They govern how drive option
  37      * index maps to unit and bus.  That mapping is ABI.
  38      *
  39      * All controllers used to imlement if=T drives need to support
  40      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
  41      * Otherwise, some index values map to "impossible" bus, unit
  42      * values.
  43      *
  44      * For instance, if you change [IF_SCSI] to 255, -drive
  45      * if=scsi,index=12 no longer means bus=1,unit=5, but
  46      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
  47      * the drive can't be set up.  Regression.
  48      */
  49     [IF_IDE] = 2,
  50     [IF_SCSI] = 7,
  51 };
  52
  53 /*
  54  * We automatically delete the drive when a device using it gets
  55  * unplugged.  Questionable feature, but we can't just drop it.
  56  * Device models call blockdev_mark_auto_del() to schedule the
  57  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  58  * when deletion is actually safe.
  59  */
  60 void blockdev_mark_auto_del(BlockDriverState *bs)
  61 {
  62     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  63
  64     if (dinfo) {
  65         dinfo->auto_del = 1;
  66     }
  67 }
  68
  69 void blockdev_auto_del(BlockDriverState *bs)
  70 {
  71     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  72
  73     if (dinfo && dinfo->auto_del) {
  74         drive_put_ref(dinfo);
  75     }
  76 }
  77
  78 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
  79 {
  80     int max_devs = if_max_devs[type];
  81     return max_devs ? index / max_devs : 0;
  82 }
  83
  84 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
  85 {
  86     int max_devs = if_max_devs[type];
  87     return max_devs ? index % max_devs : index;
  88 }
  89
  90 QemuOpts *drive_def(const char *optstr)
  91 {
  92     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  93 }
  94
  95 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
  96                     const char *optstr)
  97 {
  98     QemuOpts *opts;
  99     char buf[32];
 100
 101     opts = drive_def(optstr);
 102     if (!opts) {
 103         return NULL;
 104     }
 105     if (type != IF_DEFAULT) {
 106         qemu_opt_set(opts, "if", if_name[type]);
 107     }
 108     if (index >= 0) {
 109         snprintf(buf, sizeof(buf), "%d", index);
 110         qemu_opt_set(opts, "index", buf);
 111     }
 112     if (file)
 113         qemu_opt_set(opts, "file", file);
 114     return opts;
 115 }
 116
 117 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
 118 {
 119     DriveInfo *dinfo;
 120
 121     /* seek interface, bus and unit */
 122
 123     QTAILQ_FOREACH(dinfo, &drives, next) {
 124         if (dinfo->type == type &&
 125             dinfo->bus == bus &&
 126             dinfo->unit == unit)
 127             return dinfo;
 128     }
 129
 130     return NULL;
 131 }
 132
 133 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
 134 {
 135     return drive_get(type,
 136                      drive_index_to_bus_id(type, index),
 137                      drive_index_to_unit_id(type, index));
 138 }
 139
 140 int drive_get_max_bus(BlockInterfaceType type)
 141 {
 142     int max_bus;
 143     DriveInfo *dinfo;
 144
 145     max_bus = -1;
 146     QTAILQ_FOREACH(dinfo, &drives, next) {
 147         if(dinfo->type == type &&
 148            dinfo->bus > max_bus)
 149             max_bus = dinfo->bus;
 150     }
 151     return max_bus;
 152 }
 153
 154 /* Get a block device.  This should only be used for single-drive devices
 155    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
 156    appropriate bus.  */
 157 DriveInfo *drive_get_next(BlockInterfaceType type)
 158 {
 159     static int next_block_unit[IF_COUNT];
 160
 161     return drive_get(type, 0, next_block_unit[type]++);
 162 }
 163
 164 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 165 {
 166     DriveInfo *dinfo;
 167
 168     QTAILQ_FOREACH(dinfo, &drives, next) {
 169         if (dinfo->bdrv == bs) {
 170             return dinfo;
 171         }
 172     }
 173     return NULL;
 174 }
 175
 176 static void bdrv_format_print(void *opaque, const char *name)
 177 {
 178     error_printf(" %s", name);
 179 }
 180
 181 static void drive_uninit(DriveInfo *dinfo)
 182 {
 183     qemu_opts_del(dinfo->opts);
 184     bdrv_delete(dinfo->bdrv);
 185     QTAILQ_REMOVE(&drives, dinfo, next);
 186     qemu_free(dinfo);
 187 }
 188
 189 void drive_put_ref(DriveInfo *dinfo)
 190 {
 191     assert(dinfo->refcount);
 192     if (--dinfo->refcount == 0) {
 193         drive_uninit(dinfo);
 194     }
 195 }
 196
 197 void drive_get_ref(DriveInfo *dinfo)
 198 {
 199     dinfo->refcount++;
 200 }
 201
 202 static int parse_block_error_action(const char *buf, int is_read)
 203 {
 204     if (!strcmp(buf, "ignore")) {
 205         return BLOCK_ERR_IGNORE;
 206     } else if (!is_read && !strcmp(buf, "enospc")) {
 207         return BLOCK_ERR_STOP_ENOSPC;
 208     } else if (!strcmp(buf, "stop")) {
 209         return BLOCK_ERR_STOP_ANY;
 210     } else if (!strcmp(buf, "report")) {
 211         return BLOCK_ERR_REPORT;
 212     } else {
 213         error_report("'%s' invalid %s error action",
 214                      buf, is_read ? "read" : "write");
 215         return -1;
 216     }
 217 }
 218
 219 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 220 {
 221     const char *buf;
 222     const char *file = NULL;
 223     char devname[128];
 224     const char *serial;
 225     const char *mediastr = "";
 226     BlockInterfaceType type;
 227     enum { MEDIA_DISK, MEDIA_CDROM } media;
 228     int bus_id, unit_id;
 229     int cyls, heads, secs, translation;
 230     BlockDriver *drv = NULL;
 231     int max_devs;
 232     int index;
 233     int ro = 0;
 234     int bdrv_flags = 0;
 235     int on_read_error, on_write_error;
 236     const char *devaddr;
 237     DriveInfo *dinfo;
 238     int snapshot = 0;
 239     int ret;
 240
 241     translation = BIOS_ATA_TRANSLATION_AUTO;
 242
 243     if (default_to_scsi) {
 244         type = IF_SCSI;
 245         pstrcpy(devname, sizeof(devname), "scsi");
 246     } else {
 247         type = IF_IDE;
 248         pstrcpy(devname, sizeof(devname), "ide");
 249     }
 250     media = MEDIA_DISK;
 251
 252     /* extract parameters */
 253     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 254     unit_id = qemu_opt_get_number(opts, "unit", -1);
 255     index   = qemu_opt_get_number(opts, "index", -1);
 256
 257     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 258     heads = qemu_opt_get_number(opts, "heads", 0);
 259     secs  = qemu_opt_get_number(opts, "secs", 0);
 260
 261     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 262     ro = qemu_opt_get_bool(opts, "readonly", 0);
 263
 264     file = qemu_opt_get(opts, "file");
 265     serial = qemu_opt_get(opts, "serial");
 266
 267     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 268         pstrcpy(devname, sizeof(devname), buf);
 269         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 270             ;
 271         if (type == IF_COUNT) {
 272             error_report("unsupported bus type '%s'", buf);
 273             return NULL;
 274         }
 275     }
 276     max_devs = if_max_devs[type];
 277
 278     if (cyls || heads || secs) {
 279         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 280             error_report("invalid physical cyls number");
 281             return NULL;
 282         }
 283         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 284             error_report("invalid physical heads number");
 285             return NULL;
 286         }
 287         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 288             error_report("invalid physical secs number");
 289             return NULL;
 290         }
 291     }
 292
 293     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 294         if (!cyls) {
 295             error_report("'%s' trans must be used with cyls,heads and secs",
 296                          buf);
 297             return NULL;
 298         }
 299         if (!strcmp(buf, "none"))
 300             translation = BIOS_ATA_TRANSLATION_NONE;
 301         else if (!strcmp(buf, "lba"))
 302             translation = BIOS_ATA_TRANSLATION_LBA;
 303         else if (!strcmp(buf, "auto"))
 304             translation = BIOS_ATA_TRANSLATION_AUTO;
 305         else {
 306             error_report("'%s' invalid translation type", buf);
 307             return NULL;
 308         }
 309     }
 310
 311     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 312         if (!strcmp(buf, "disk")) {
 313             media = MEDIA_DISK;
 314         } else if (!strcmp(buf, "cdrom")) {
 315             if (cyls || secs || heads) {
 316                 error_report("'%s' invalid physical CHS format", buf);
 317                 return NULL;
 318             }
 319             media = MEDIA_CDROM;
 320         } else {
 321             error_report("'%s' invalid media", buf);
 322             return NULL;
 323         }
 324     }
 325
 326     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 327         if (!strcmp(buf, "off") || !strcmp(buf, "none")) {
 328             bdrv_flags |= BDRV_O_NOCACHE;
 329         } else if (!strcmp(buf, "writeback")) {
 330             bdrv_flags |= BDRV_O_CACHE_WB;
 331         } else if (!strcmp(buf, "unsafe")) {
 332             bdrv_flags |= BDRV_O_CACHE_WB;
 333             bdrv_flags |= BDRV_O_NO_FLUSH;
 334         } else if (!strcmp(buf, "writethrough")) {
 335             /* this is the default */
 336         } else {
 337            error_report("invalid cache option");
 338            return NULL;
 339         }
 340     }
 341
 342 #ifdef CONFIG_LINUX_AIO
 343     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 344         if (!strcmp(buf, "native")) {
 345             bdrv_flags |= BDRV_O_NATIVE_AIO;
 346         } else if (!strcmp(buf, "threads")) {
 347             /* this is the default */
 348         } else {
 349            error_report("invalid aio option");
 350            return NULL;
 351         }
 352     }
 353 #endif
 354
 355     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 356        if (strcmp(buf, "?") == 0) {
 357            error_printf("Supported formats:");
 358            bdrv_iterate_format(bdrv_format_print, NULL);
 359            error_printf("\n");
 360            return NULL;
 361         }
 362         drv = bdrv_find_whitelisted_format(buf);
 363         if (!drv) {
 364             error_report("'%s' invalid format", buf);
 365             return NULL;
 366         }
 367     }
 368
 369     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 370     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 371         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 372             error_report("werror is not supported by this bus type");
 373             return NULL;
 374         }
 375
 376         on_write_error = parse_block_error_action(buf, 0);
 377         if (on_write_error < 0) {
 378             return NULL;
 379         }
 380     }
 381
 382     on_read_error = BLOCK_ERR_REPORT;
 383     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 384         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 385             error_report("rerror is not supported by this bus type");
 386             return NULL;
 387         }
 388
 389         on_read_error = parse_block_error_action(buf, 1);
 390         if (on_read_error < 0) {
 391             return NULL;
 392         }
 393     }
 394
 395     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 396         if (type != IF_VIRTIO) {
 397             error_report("addr is not supported by this bus type");
 398             return NULL;
 399         }
 400     }
 401
 402     /* compute bus and unit according index */
 403
 404     if (index != -1) {
 405         if (bus_id != 0 || unit_id != -1) {
 406             error_report("index cannot be used with bus and unit");
 407             return NULL;
 408         }
 409         bus_id = drive_index_to_bus_id(type, index);
 410         unit_id = drive_index_to_unit_id(type, index);
 411     }
 412
 413     /* if user doesn't specify a unit_id,
 414      * try to find the first free
 415      */
 416
 417     if (unit_id == -1) {
 418        unit_id = 0;
 419        while (drive_get(type, bus_id, unit_id) != NULL) {
 420            unit_id++;
 421            if (max_devs && unit_id >= max_devs) {
 422                unit_id -= max_devs;
 423                bus_id++;
 424            }
 425        }
 426     }
 427
 428     /* check unit id */
 429
 430     if (max_devs && unit_id >= max_devs) {
 431         error_report("unit %d too big (max is %d)",
 432                      unit_id, max_devs - 1);
 433         return NULL;
 434     }
 435
 436     /*
 437      * catch multiple definitions
 438      */
 439
 440     if (drive_get(type, bus_id, unit_id) != NULL) {
 441         error_report("drive with bus=%d, unit=%d (index=%d) exists",
 442                      bus_id, unit_id, index);
 443         return NULL;
 444     }
 445
 446     /* init */
 447
 448     dinfo = qemu_mallocz(sizeof(*dinfo));
 449     if ((buf = qemu_opts_id(opts)) != NULL) {
 450         dinfo->id = qemu_strdup(buf);
 451     } else {
 452         /* no id supplied -> create one */
 453         dinfo->id = qemu_mallocz(32);
 454         if (type == IF_IDE || type == IF_SCSI)
 455             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 456         if (max_devs)
 457             snprintf(dinfo->id, 32, "%s%i%s%i",
 458                      devname, bus_id, mediastr, unit_id);
 459         else
 460             snprintf(dinfo->id, 32, "%s%s%i",
 461                      devname, mediastr, unit_id);
 462     }
 463     dinfo->bdrv = bdrv_new(dinfo->id);
 464     dinfo->devaddr = devaddr;
 465     dinfo->type = type;
 466     dinfo->bus = bus_id;
 467     dinfo->unit = unit_id;
 468     dinfo->opts = opts;
 469     dinfo->refcount = 1;
 470     if (serial)
 471         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 472     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 473
 474     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 475
 476     switch(type) {
 477     case IF_IDE:
 478     case IF_SCSI:
 479     case IF_XEN:
 480     case IF_NONE:
 481         switch(media) {
 482         case MEDIA_DISK:
 483             if (cyls != 0) {
 484                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 485                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 486             }
 487             break;
 488         case MEDIA_CDROM:
 489             bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_CDROM);
 490             break;
 491         }
 492         break;
 493     case IF_SD:
 494         /* FIXME: This isn't really a floppy, but it's a reasonable
 495            approximation.  */
 496     case IF_FLOPPY:
 497         bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_FLOPPY);
 498         break;
 499     case IF_PFLASH:
 500     case IF_MTD:
 501         break;
 502     case IF_VIRTIO:
 503         /* add virtio block device */
 504         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 505         qemu_opt_set(opts, "driver", "virtio-blk-pci");
 506         qemu_opt_set(opts, "drive", dinfo->id);
 507         if (devaddr)
 508             qemu_opt_set(opts, "addr", devaddr);
 509         break;
 510     default:
 511         abort();
 512     }
 513     if (!file || !*file) {
 514         return dinfo;
 515     }
 516     if (snapshot) {
 517         /* always use cache=unsafe with snapshot */
 518         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 519         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 520     }
 521
 522     if (media == MEDIA_CDROM) {
 523         /* CDROM is fine for any interface, don't check.  */
 524         ro = 1;
 525     } else if (ro == 1) {
 526         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 527             error_report("readonly not supported by this bus type");
 528             return NULL;
 529         }
 530     }
 531
 532     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 533
 534     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 535     if (ret < 0) {
 536         error_report("could not open disk image %s: %s",
 537                      file, strerror(-ret));
 538         return NULL;
 539     }
 540
 541     if (bdrv_key_required(dinfo->bdrv))
 542         autostart = 0;
 543     return dinfo;
 544 }
 545
 546 void do_commit(Monitor *mon, const QDict *qdict)
 547 {
 548     const char *device = qdict_get_str(qdict, "device");
 549     BlockDriverState *bs;
 550
 551     if (!strcmp(device, "all")) {
 552         bdrv_commit_all();
 553     } else {
 554         bs = bdrv_find(device);
 555         if (!bs) {
 556             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 557             return;
 558         }
 559         bdrv_commit(bs);
 560     }
 561 }
 562
 563 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
 564 {
 565     const char *device = qdict_get_str(qdict, "device");
 566     const char *filename = qdict_get_try_str(qdict, "snapshot_file");
 567     const char *format = qdict_get_try_str(qdict, "format");
 568     BlockDriverState *bs;
 569     BlockDriver *drv, *proto_drv;
 570     int ret = 0;
 571     int flags;
 572
 573     if (!filename) {
 574         qerror_report(QERR_MISSING_PARAMETER, "snapshot_file");
 575         ret = -1;
 576         goto out;
 577     }
 578
 579     bs = bdrv_find(device);
 580     if (!bs) {
 581         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 582         ret = -1;
 583         goto out;
 584     }
 585
 586     if (!format) {
 587         format = "qcow2";
 588     }
 589
 590     drv = bdrv_find_format(format);
 591     if (!drv) {
 592         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 593         ret = -1;
 594         goto out;
 595     }
 596
 597     proto_drv = bdrv_find_protocol(filename);
 598     if (!proto_drv) {
 599         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 600         ret = -1;
 601         goto out;
 602     }
 603
 604     ret = bdrv_img_create(filename, format, bs->filename,
 605                           bs->drv->format_name, NULL, -1, bs->open_flags);
 606     if (ret) {
 607         goto out;
 608     }
 609
 610     qemu_aio_flush();
 611     bdrv_flush(bs);
 612
 613     flags = bs->open_flags;
 614     bdrv_close(bs);
 615     ret = bdrv_open(bs, filename, flags, drv);
 616     /*
 617      * If reopening the image file we just created fails, we really
 618      * are in trouble :(
 619      */
 620     if (ret != 0) {
 621         abort();
 622     }
 623 out:
 624     if (ret) {
 625         ret = -1;
 626     }
 627
 628     return ret;
 629 }
 630
 631 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
 632 {
 633     if (!force) {
 634         if (!bdrv_is_removable(bs)) {
 635             qerror_report(QERR_DEVICE_NOT_REMOVABLE,
 636                            bdrv_get_device_name(bs));
 637             return -1;
 638         }
 639         if (bdrv_is_locked(bs)) {
 640             qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 641             return -1;
 642         }
 643     }
 644     bdrv_close(bs);
 645     return 0;
 646 }
 647
 648 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 649 {
 650     BlockDriverState *bs;
 651     int force = qdict_get_try_bool(qdict, "force", 0);
 652     const char *filename = qdict_get_str(qdict, "device");
 653
 654     bs = bdrv_find(filename);
 655     if (!bs) {
 656         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
 657         return -1;
 658     }
 659     return eject_device(mon, bs, force);
 660 }
 661
 662 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 663                         QObject **ret_data)
 664 {
 665     BlockDriverState *bs;
 666     int err;
 667
 668     bs = bdrv_find(qdict_get_str(qdict, "device"));
 669     if (!bs) {
 670         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
 671         return -1;
 672     }
 673
 674     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
 675     if (err == -EINVAL) {
 676         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 677         return -1;
 678     } else if (err < 0) {
 679         qerror_report(QERR_INVALID_PASSWORD);
 680         return -1;
 681     }
 682
 683     return 0;
 684 }
 685
 686 int do_change_block(Monitor *mon, const char *device,
 687                     const char *filename, const char *fmt)
 688 {
 689     BlockDriverState *bs;
 690     BlockDriver *drv = NULL;
 691     int bdrv_flags;
 692
 693     bs = bdrv_find(device);
 694     if (!bs) {
 695         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 696         return -1;
 697     }
 698     if (fmt) {
 699         drv = bdrv_find_whitelisted_format(fmt);
 700         if (!drv) {
 701             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
 702             return -1;
 703         }
 704     }
 705     if (eject_device(mon, bs, 0) < 0) {
 706         return -1;
 707     }
 708     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 709     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 710     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 711         qerror_report(QERR_OPEN_FILE_FAILED, filename);
 712         return -1;
 713     }
 714     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 715 }
 716
 717 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 718 {
 719     const char *id = qdict_get_str(qdict, "id");
 720     BlockDriverState *bs;
 721     BlockDriverState **ptr;
 722     Property *prop;
 723
 724     bs = bdrv_find(id);
 725     if (!bs) {
 726         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 727         return -1;
 728     }
 729     if (bdrv_in_use(bs)) {
 730         qerror_report(QERR_DEVICE_IN_USE, id);
 731         return -1;
 732     }
 733
 734     /* quiesce block driver; prevent further io */
 735     qemu_aio_flush();
 736     bdrv_flush(bs);
 737     bdrv_close(bs);
 738
 739     /* clean up guest state from pointing to host resource by
 740      * finding and removing DeviceState "drive" property */
 741     if (bs->peer) {
 742         for (prop = bs->peer->info->props; prop && prop->name; prop++) {
 743             if (prop->info->type == PROP_TYPE_DRIVE) {
 744                 ptr = qdev_get_prop_ptr(bs->peer, prop);
 745                 if (*ptr == bs) {
 746                     bdrv_detach(bs, bs->peer);
 747                     *ptr = NULL;
 748                     break;
 749                 }
 750             }
 751         }
 752     }
 753
 754     /* clean up host side */
 755     drive_uninit(drive_get_by_blockdev(bs));
 756
 757     return 0;
 758 }
 759
 760 /*
 761  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
 762  * existing QERR_ macro mess is cleaned up.  A good example for better
 763  * error reports can be found in the qemu-img resize code.
 764  */
 765 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
 766 {
 767     const char *device = qdict_get_str(qdict, "device");
 768     int64_t size = qdict_get_int(qdict, "size");
 769     BlockDriverState *bs;
 770
 771     bs = bdrv_find(device);
 772     if (!bs) {
 773         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 774         return -1;
 775     }
 776
 777     if (size < 0) {
 778         qerror_report(QERR_UNDEFINED_ERROR);
 779         return -1;
 780     }
 781
 782     if (bdrv_truncate(bs, size)) {
 783         qerror_report(QERR_UNDEFINED_ERROR);
 784         return -1;
 785     }
 786
 787     return 0;
 788 }