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     [IF_IDE] = MAX_IDE_DEVS,
  36     [IF_SCSI] = MAX_SCSI_DEVS,
  37 };
  38
  39 /*
  40  * We automatically delete the drive when a device using it gets
  41  * unplugged.  Questionable feature, but we can't just drop it.
  42  * Device models call blockdev_mark_auto_del() to schedule the
  43  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  44  * when deletion is actually safe.
  45  */
  46 void blockdev_mark_auto_del(BlockDriverState *bs)
  47 {
  48     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  49
  50     if (dinfo) {
  51         dinfo->auto_del = 1;
  52     }
  53 }
  54
  55 void blockdev_auto_del(BlockDriverState *bs)
  56 {
  57     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  58
  59     if (dinfo && dinfo->auto_del) {
  60         drive_uninit(dinfo);
  61     }
  62 }
  63
  64 QemuOpts *drive_add(const char *file, const char *fmt, ...)
  65 {
  66     va_list ap;
  67     char optstr[1024];
  68     QemuOpts *opts;
  69
  70     va_start(ap, fmt);
  71     vsnprintf(optstr, sizeof(optstr), fmt, ap);
  72     va_end(ap);
  73
  74     opts = qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  75     if (!opts) {
  76         return NULL;
  77     }
  78     if (file)
  79         qemu_opt_set(opts, "file", file);
  80     return opts;
  81 }
  82
  83 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
  84 {
  85     DriveInfo *dinfo;
  86
  87     /* seek interface, bus and unit */
  88
  89     QTAILQ_FOREACH(dinfo, &drives, next) {
  90         if (dinfo->type == type &&
  91             dinfo->bus == bus &&
  92             dinfo->unit == unit)
  93             return dinfo;
  94     }
  95
  96     return NULL;
  97 }
  98
  99 int drive_get_max_bus(BlockInterfaceType type)
 100 {
 101     int max_bus;
 102     DriveInfo *dinfo;
 103
 104     max_bus = -1;
 105     QTAILQ_FOREACH(dinfo, &drives, next) {
 106         if(dinfo->type == type &&
 107            dinfo->bus > max_bus)
 108             max_bus = dinfo->bus;
 109     }
 110     return max_bus;
 111 }
 112
 113 /* Get a block device.  This should only be used for single-drive devices
 114    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
 115    appropriate bus.  */
 116 DriveInfo *drive_get_next(BlockInterfaceType type)
 117 {
 118     static int next_block_unit[IF_COUNT];
 119
 120     return drive_get(type, 0, next_block_unit[type]++);
 121 }
 122
 123 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 124 {
 125     DriveInfo *dinfo;
 126
 127     QTAILQ_FOREACH(dinfo, &drives, next) {
 128         if (dinfo->bdrv == bs) {
 129             return dinfo;
 130         }
 131     }
 132     return NULL;
 133 }
 134
 135 static void bdrv_format_print(void *opaque, const char *name)
 136 {
 137     error_printf(" %s", name);
 138 }
 139
 140 void drive_uninit(DriveInfo *dinfo)
 141 {
 142     qemu_opts_del(dinfo->opts);
 143     bdrv_delete(dinfo->bdrv);
 144     QTAILQ_REMOVE(&drives, dinfo, next);
 145     qemu_free(dinfo);
 146 }
 147
 148 static int parse_block_error_action(const char *buf, int is_read)
 149 {
 150     if (!strcmp(buf, "ignore")) {
 151         return BLOCK_ERR_IGNORE;
 152     } else if (!is_read && !strcmp(buf, "enospc")) {
 153         return BLOCK_ERR_STOP_ENOSPC;
 154     } else if (!strcmp(buf, "stop")) {
 155         return BLOCK_ERR_STOP_ANY;
 156     } else if (!strcmp(buf, "report")) {
 157         return BLOCK_ERR_REPORT;
 158     } else {
 159         error_report("'%s' invalid %s error action",
 160                      buf, is_read ? "read" : "write");
 161         return -1;
 162     }
 163 }
 164
 165 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi, int *fatal_error)
 166 {
 167     const char *buf;
 168     const char *file = NULL;
 169     char devname[128];
 170     const char *serial;
 171     const char *mediastr = "";
 172     BlockInterfaceType type;
 173     enum { MEDIA_DISK, MEDIA_CDROM } media;
 174     int bus_id, unit_id;
 175     int cyls, heads, secs, translation;
 176     BlockDriver *drv = NULL;
 177     int max_devs;
 178     int index;
 179     int ro = 0;
 180     int bdrv_flags = 0;
 181     int on_read_error, on_write_error;
 182     const char *devaddr;
 183     DriveInfo *dinfo;
 184     int snapshot = 0;
 185     int ret;
 186
 187     *fatal_error = 1;
 188
 189     translation = BIOS_ATA_TRANSLATION_AUTO;
 190
 191     if (default_to_scsi) {
 192         type = IF_SCSI;
 193         pstrcpy(devname, sizeof(devname), "scsi");
 194     } else {
 195         type = IF_IDE;
 196         pstrcpy(devname, sizeof(devname), "ide");
 197     }
 198     media = MEDIA_DISK;
 199
 200     /* extract parameters */
 201     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 202     unit_id = qemu_opt_get_number(opts, "unit", -1);
 203     index   = qemu_opt_get_number(opts, "index", -1);
 204
 205     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 206     heads = qemu_opt_get_number(opts, "heads", 0);
 207     secs  = qemu_opt_get_number(opts, "secs", 0);
 208
 209     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 210     ro = qemu_opt_get_bool(opts, "readonly", 0);
 211
 212     file = qemu_opt_get(opts, "file");
 213     serial = qemu_opt_get(opts, "serial");
 214
 215     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 216         pstrcpy(devname, sizeof(devname), buf);
 217         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 218             ;
 219         if (type == IF_COUNT) {
 220             error_report("unsupported bus type '%s'", buf);
 221             return NULL;
 222         }
 223     }
 224     max_devs = if_max_devs[type];
 225
 226     if (cyls || heads || secs) {
 227         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 228             error_report("invalid physical cyls number");
 229             return NULL;
 230         }
 231         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 232             error_report("invalid physical heads number");
 233             return NULL;
 234         }
 235         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 236             error_report("invalid physical secs number");
 237             return NULL;
 238         }
 239     }
 240
 241     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 242         if (!cyls) {
 243             error_report("'%s' trans must be used with cyls,heads and secs",
 244                          buf);
 245             return NULL;
 246         }
 247         if (!strcmp(buf, "none"))
 248             translation = BIOS_ATA_TRANSLATION_NONE;
 249         else if (!strcmp(buf, "lba"))
 250             translation = BIOS_ATA_TRANSLATION_LBA;
 251         else if (!strcmp(buf, "auto"))
 252             translation = BIOS_ATA_TRANSLATION_AUTO;
 253         else {
 254             error_report("'%s' invalid translation type", buf);
 255             return NULL;
 256         }
 257     }
 258
 259     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 260         if (!strcmp(buf, "disk")) {
 261             media = MEDIA_DISK;
 262         } else if (!strcmp(buf, "cdrom")) {
 263             if (cyls || secs || heads) {
 264                 error_report("'%s' invalid physical CHS format", buf);
 265                 return NULL;
 266             }
 267             media = MEDIA_CDROM;
 268         } else {
 269             error_report("'%s' invalid media", buf);
 270             return NULL;
 271         }
 272     }
 273
 274     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 275         if (!strcmp(buf, "off") || !strcmp(buf, "none")) {
 276             bdrv_flags |= BDRV_O_NOCACHE;
 277         } else if (!strcmp(buf, "writeback")) {
 278             bdrv_flags |= BDRV_O_CACHE_WB;
 279         } else if (!strcmp(buf, "unsafe")) {
 280             bdrv_flags |= BDRV_O_CACHE_WB;
 281             bdrv_flags |= BDRV_O_NO_FLUSH;
 282         } else if (!strcmp(buf, "writethrough")) {
 283             /* this is the default */
 284         } else {
 285            error_report("invalid cache option");
 286            return NULL;
 287         }
 288     }
 289
 290 #ifdef CONFIG_LINUX_AIO
 291     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 292         if (!strcmp(buf, "native")) {
 293             bdrv_flags |= BDRV_O_NATIVE_AIO;
 294         } else if (!strcmp(buf, "threads")) {
 295             /* this is the default */
 296         } else {
 297            error_report("invalid aio option");
 298            return NULL;
 299         }
 300     }
 301 #endif
 302
 303     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 304        if (strcmp(buf, "?") == 0) {
 305            error_printf("Supported formats:");
 306            bdrv_iterate_format(bdrv_format_print, NULL);
 307            error_printf("\n");
 308            return NULL;
 309         }
 310         drv = bdrv_find_whitelisted_format(buf);
 311         if (!drv) {
 312             error_report("'%s' invalid format", buf);
 313             return NULL;
 314         }
 315     }
 316
 317     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 318     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 319         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 320             error_report("werror is not supported by this bus type");
 321             return NULL;
 322         }
 323
 324         on_write_error = parse_block_error_action(buf, 0);
 325         if (on_write_error < 0) {
 326             return NULL;
 327         }
 328     }
 329
 330     on_read_error = BLOCK_ERR_REPORT;
 331     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 332         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 333             error_report("rerror is not supported by this bus type");
 334             return NULL;
 335         }
 336
 337         on_read_error = parse_block_error_action(buf, 1);
 338         if (on_read_error < 0) {
 339             return NULL;
 340         }
 341     }
 342
 343     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 344         if (type != IF_VIRTIO) {
 345             error_report("addr is not supported by this bus type");
 346             return NULL;
 347         }
 348     }
 349
 350     /* compute bus and unit according index */
 351
 352     if (index != -1) {
 353         if (bus_id != 0 || unit_id != -1) {
 354             error_report("index cannot be used with bus and unit");
 355             return NULL;
 356         }
 357         if (max_devs == 0)
 358         {
 359             unit_id = index;
 360             bus_id = 0;
 361         } else {
 362             unit_id = index % max_devs;
 363             bus_id = index / max_devs;
 364         }
 365     }
 366
 367     /* if user doesn't specify a unit_id,
 368      * try to find the first free
 369      */
 370
 371     if (unit_id == -1) {
 372        unit_id = 0;
 373        while (drive_get(type, bus_id, unit_id) != NULL) {
 374            unit_id++;
 375            if (max_devs && unit_id >= max_devs) {
 376                unit_id -= max_devs;
 377                bus_id++;
 378            }
 379        }
 380     }
 381
 382     /* check unit id */
 383
 384     if (max_devs && unit_id >= max_devs) {
 385         error_report("unit %d too big (max is %d)",
 386                      unit_id, max_devs - 1);
 387         return NULL;
 388     }
 389
 390     /*
 391      * ignore multiple definitions
 392      */
 393
 394     if (drive_get(type, bus_id, unit_id) != NULL) {
 395         *fatal_error = 0;
 396         return NULL;
 397     }
 398
 399     /* init */
 400
 401     dinfo = qemu_mallocz(sizeof(*dinfo));
 402     if ((buf = qemu_opts_id(opts)) != NULL) {
 403         dinfo->id = qemu_strdup(buf);
 404     } else {
 405         /* no id supplied -> create one */
 406         dinfo->id = qemu_mallocz(32);
 407         if (type == IF_IDE || type == IF_SCSI)
 408             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 409         if (max_devs)
 410             snprintf(dinfo->id, 32, "%s%i%s%i",
 411                      devname, bus_id, mediastr, unit_id);
 412         else
 413             snprintf(dinfo->id, 32, "%s%s%i",
 414                      devname, mediastr, unit_id);
 415     }
 416     dinfo->bdrv = bdrv_new(dinfo->id);
 417     dinfo->devaddr = devaddr;
 418     dinfo->type = type;
 419     dinfo->bus = bus_id;
 420     dinfo->unit = unit_id;
 421     dinfo->opts = opts;
 422     if (serial)
 423         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 424     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 425
 426     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 427
 428     switch(type) {
 429     case IF_IDE:
 430     case IF_SCSI:
 431     case IF_XEN:
 432     case IF_NONE:
 433         switch(media) {
 434         case MEDIA_DISK:
 435             if (cyls != 0) {
 436                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 437                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 438             }
 439             break;
 440         case MEDIA_CDROM:
 441             bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_CDROM);
 442             break;
 443         }
 444         break;
 445     case IF_SD:
 446         /* FIXME: This isn't really a floppy, but it's a reasonable
 447            approximation.  */
 448     case IF_FLOPPY:
 449         bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_FLOPPY);
 450         break;
 451     case IF_PFLASH:
 452     case IF_MTD:
 453         break;
 454     case IF_VIRTIO:
 455         /* add virtio block device */
 456         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 457         qemu_opt_set(opts, "driver", "virtio-blk-pci");
 458         qemu_opt_set(opts, "drive", dinfo->id);
 459         if (devaddr)
 460             qemu_opt_set(opts, "addr", devaddr);
 461         break;
 462     case IF_COUNT:
 463         abort();
 464     }
 465     if (!file || !*file) {
 466         *fatal_error = 0;
 467         return NULL;
 468     }
 469     if (snapshot) {
 470         /* always use cache=unsafe with snapshot */
 471         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 472         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 473     }
 474
 475     if (media == MEDIA_CDROM) {
 476         /* CDROM is fine for any interface, don't check.  */
 477         ro = 1;
 478     } else if (ro == 1) {
 479         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 480             error_report("readonly not supported by this bus type");
 481             return NULL;
 482         }
 483     }
 484
 485     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 486
 487     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 488     if (ret < 0) {
 489         error_report("could not open disk image %s: %s",
 490                      file, strerror(-ret));
 491         return NULL;
 492     }
 493
 494     if (bdrv_key_required(dinfo->bdrv))
 495         autostart = 0;
 496     *fatal_error = 0;
 497     return dinfo;
 498 }
 499
 500 void do_commit(Monitor *mon, const QDict *qdict)
 501 {
 502     const char *device = qdict_get_str(qdict, "device");
 503     BlockDriverState *bs;
 504
 505     if (!strcmp(device, "all")) {
 506         bdrv_commit_all();
 507     } else {
 508         bs = bdrv_find(device);
 509         if (!bs) {
 510             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 511             return;
 512         }
 513         bdrv_commit(bs);
 514     }
 515 }
 516
 517 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
 518 {
 519     const char *device = qdict_get_str(qdict, "device");
 520     const char *filename = qdict_get_try_str(qdict, "snapshot_file");
 521     const char *format = qdict_get_try_str(qdict, "format");
 522     BlockDriverState *bs;
 523     BlockDriver *drv, *proto_drv;
 524     int ret = 0;
 525     int flags;
 526
 527     if (!filename) {
 528         qerror_report(QERR_MISSING_PARAMETER, "snapshot_file");
 529         ret = -1;
 530         goto out;
 531     }
 532
 533     bs = bdrv_find(device);
 534     if (!bs) {
 535         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 536         ret = -1;
 537         goto out;
 538     }
 539
 540     if (!format) {
 541         format = "qcow2";
 542     }
 543
 544     drv = bdrv_find_format(format);
 545     if (!drv) {
 546         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 547         ret = -1;
 548         goto out;
 549     }
 550
 551     proto_drv = bdrv_find_protocol(filename);
 552     if (!proto_drv) {
 553         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 554         ret = -1;
 555         goto out;
 556     }
 557
 558     ret = bdrv_img_create(filename, format, bs->filename,
 559                           bs->drv->format_name, NULL, -1, bs->open_flags);
 560     if (ret) {
 561         goto out;
 562     }
 563
 564     qemu_aio_flush();
 565     bdrv_flush(bs);
 566
 567     flags = bs->open_flags;
 568     bdrv_close(bs);
 569     ret = bdrv_open(bs, filename, flags, drv);
 570     /*
 571      * If reopening the image file we just created fails, we really
 572      * are in trouble :(
 573      */
 574     if (ret != 0) {
 575         abort();
 576     }
 577 out:
 578     if (ret) {
 579         ret = -1;
 580     }
 581
 582     return ret;
 583 }
 584
 585 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
 586 {
 587     if (!force) {
 588         if (!bdrv_is_removable(bs)) {
 589             qerror_report(QERR_DEVICE_NOT_REMOVABLE,
 590                            bdrv_get_device_name(bs));
 591             return -1;
 592         }
 593         if (bdrv_is_locked(bs)) {
 594             qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 595             return -1;
 596         }
 597     }
 598     bdrv_close(bs);
 599     return 0;
 600 }
 601
 602 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 603 {
 604     BlockDriverState *bs;
 605     int force = qdict_get_try_bool(qdict, "force", 0);
 606     const char *filename = qdict_get_str(qdict, "device");
 607
 608     bs = bdrv_find(filename);
 609     if (!bs) {
 610         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
 611         return -1;
 612     }
 613     return eject_device(mon, bs, force);
 614 }
 615
 616 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 617                         QObject **ret_data)
 618 {
 619     BlockDriverState *bs;
 620     int err;
 621
 622     bs = bdrv_find(qdict_get_str(qdict, "device"));
 623     if (!bs) {
 624         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
 625         return -1;
 626     }
 627
 628     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
 629     if (err == -EINVAL) {
 630         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 631         return -1;
 632     } else if (err < 0) {
 633         qerror_report(QERR_INVALID_PASSWORD);
 634         return -1;
 635     }
 636
 637     return 0;
 638 }
 639
 640 int do_change_block(Monitor *mon, const char *device,
 641                     const char *filename, const char *fmt)
 642 {
 643     BlockDriverState *bs;
 644     BlockDriver *drv = NULL;
 645     int bdrv_flags;
 646
 647     bs = bdrv_find(device);
 648     if (!bs) {
 649         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 650         return -1;
 651     }
 652     if (fmt) {
 653         drv = bdrv_find_whitelisted_format(fmt);
 654         if (!drv) {
 655             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
 656             return -1;
 657         }
 658     }
 659     if (eject_device(mon, bs, 0) < 0) {
 660         return -1;
 661     }
 662     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 663     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 664     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 665         qerror_report(QERR_OPEN_FILE_FAILED, filename);
 666         return -1;
 667     }
 668     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 669 }
 670
 671 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 672 {
 673     const char *id = qdict_get_str(qdict, "id");
 674     BlockDriverState *bs;
 675     BlockDriverState **ptr;
 676     Property *prop;
 677
 678     bs = bdrv_find(id);
 679     if (!bs) {
 680         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 681         return -1;
 682     }
 683
 684     /* quiesce block driver; prevent further io */
 685     qemu_aio_flush();
 686     bdrv_flush(bs);
 687     bdrv_close(bs);
 688
 689     /* clean up guest state from pointing to host resource by
 690      * finding and removing DeviceState "drive" property */
 691     if (bs->peer) {
 692         for (prop = bs->peer->info->props; prop && prop->name; prop++) {
 693             if (prop->info->type == PROP_TYPE_DRIVE) {
 694                 ptr = qdev_get_prop_ptr(bs->peer, prop);
 695                 if (*ptr == bs) {
 696                     bdrv_detach(bs, bs->peer);
 697                     *ptr = NULL;
 698                     break;
 699                 }
 700             }
 701         }
 702     }
 703
 704     /* clean up host side */
 705     drive_uninit(drive_get_by_blockdev(bs));
 706
 707     return 0;
 708 }
 709
 710 /*
 711  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
 712  * existing QERR_ macro mess is cleaned up.  A good example for better
 713  * error reports can be found in the qemu-img resize code.
 714  */
 715 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
 716 {
 717     const char *device = qdict_get_str(qdict, "device");
 718     int64_t size = qdict_get_int(qdict, "size");
 719     BlockDriverState *bs;
 720
 721     bs = bdrv_find(device);
 722     if (!bs) {
 723         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 724         return -1;
 725     }
 726
 727     if (size < 0) {
 728         qerror_report(QERR_UNDEFINED_ERROR);
 729         return -1;
 730     }
 731
 732     if (bdrv_truncate(bs, size)) {
 733         qerror_report(QERR_UNDEFINED_ERROR);
 734         return -1;
 735     }
 736
 737     return 0;
 738 }