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 /*
  23  * We automatically delete the drive when a device using it gets
  24  * unplugged.  Questionable feature, but we can't just drop it.
  25  * Device models call blockdev_mark_auto_del() to schedule the
  26  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  27  * when deletion is actually safe.
  28  */
  29 void blockdev_mark_auto_del(BlockDriverState *bs)
  30 {
  31     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  32
  33     if (dinfo) {
  34         dinfo->auto_del = 1;
  35     }
  36 }
  37
  38 void blockdev_auto_del(BlockDriverState *bs)
  39 {
  40     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  41
  42     if (dinfo && dinfo->auto_del) {
  43         drive_uninit(dinfo);
  44     }
  45 }
  46
  47 QemuOpts *drive_add(const char *file, const char *fmt, ...)
  48 {
  49     va_list ap;
  50     char optstr[1024];
  51     QemuOpts *opts;
  52
  53     va_start(ap, fmt);
  54     vsnprintf(optstr, sizeof(optstr), fmt, ap);
  55     va_end(ap);
  56
  57     opts = qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  58     if (!opts) {
  59         return NULL;
  60     }
  61     if (file)
  62         qemu_opt_set(opts, "file", file);
  63     return opts;
  64 }
  65
  66 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
  67 {
  68     DriveInfo *dinfo;
  69
  70     /* seek interface, bus and unit */
  71
  72     QTAILQ_FOREACH(dinfo, &drives, next) {
  73         if (dinfo->type == type &&
  74             dinfo->bus == bus &&
  75             dinfo->unit == unit)
  76             return dinfo;
  77     }
  78
  79     return NULL;
  80 }
  81
  82 int drive_get_max_bus(BlockInterfaceType type)
  83 {
  84     int max_bus;
  85     DriveInfo *dinfo;
  86
  87     max_bus = -1;
  88     QTAILQ_FOREACH(dinfo, &drives, next) {
  89         if(dinfo->type == type &&
  90            dinfo->bus > max_bus)
  91             max_bus = dinfo->bus;
  92     }
  93     return max_bus;
  94 }
  95
  96 /* Get a block device.  This should only be used for single-drive devices
  97    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
  98    appropriate bus.  */
  99 DriveInfo *drive_get_next(BlockInterfaceType type)
 100 {
 101     static int next_block_unit[IF_COUNT];
 102
 103     return drive_get(type, 0, next_block_unit[type]++);
 104 }
 105
 106 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 107 {
 108     DriveInfo *dinfo;
 109
 110     QTAILQ_FOREACH(dinfo, &drives, next) {
 111         if (dinfo->bdrv == bs) {
 112             return dinfo;
 113         }
 114     }
 115     return NULL;
 116 }
 117
 118 static void bdrv_format_print(void *opaque, const char *name)
 119 {
 120     error_printf(" %s", name);
 121 }
 122
 123 void drive_uninit(DriveInfo *dinfo)
 124 {
 125     qemu_opts_del(dinfo->opts);
 126     bdrv_delete(dinfo->bdrv);
 127     QTAILQ_REMOVE(&drives, dinfo, next);
 128     qemu_free(dinfo);
 129 }
 130
 131 static int parse_block_error_action(const char *buf, int is_read)
 132 {
 133     if (!strcmp(buf, "ignore")) {
 134         return BLOCK_ERR_IGNORE;
 135     } else if (!is_read && !strcmp(buf, "enospc")) {
 136         return BLOCK_ERR_STOP_ENOSPC;
 137     } else if (!strcmp(buf, "stop")) {
 138         return BLOCK_ERR_STOP_ANY;
 139     } else if (!strcmp(buf, "report")) {
 140         return BLOCK_ERR_REPORT;
 141     } else {
 142         error_report("'%s' invalid %s error action",
 143                      buf, is_read ? "read" : "write");
 144         return -1;
 145     }
 146 }
 147
 148 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi, int *fatal_error)
 149 {
 150     const char *buf;
 151     const char *file = NULL;
 152     char devname[128];
 153     const char *serial;
 154     const char *mediastr = "";
 155     BlockInterfaceType type;
 156     enum { MEDIA_DISK, MEDIA_CDROM } media;
 157     int bus_id, unit_id;
 158     int cyls, heads, secs, translation;
 159     BlockDriver *drv = NULL;
 160     int max_devs;
 161     int index;
 162     int ro = 0;
 163     int bdrv_flags = 0;
 164     int on_read_error, on_write_error;
 165     const char *devaddr;
 166     DriveInfo *dinfo;
 167     int snapshot = 0;
 168     int ret;
 169
 170     *fatal_error = 1;
 171
 172     translation = BIOS_ATA_TRANSLATION_AUTO;
 173
 174     if (default_to_scsi) {
 175         type = IF_SCSI;
 176         max_devs = MAX_SCSI_DEVS;
 177         pstrcpy(devname, sizeof(devname), "scsi");
 178     } else {
 179         type = IF_IDE;
 180         max_devs = MAX_IDE_DEVS;
 181         pstrcpy(devname, sizeof(devname), "ide");
 182     }
 183     media = MEDIA_DISK;
 184
 185     /* extract parameters */
 186     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 187     unit_id = qemu_opt_get_number(opts, "unit", -1);
 188     index   = qemu_opt_get_number(opts, "index", -1);
 189
 190     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 191     heads = qemu_opt_get_number(opts, "heads", 0);
 192     secs  = qemu_opt_get_number(opts, "secs", 0);
 193
 194     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 195     ro = qemu_opt_get_bool(opts, "readonly", 0);
 196
 197     file = qemu_opt_get(opts, "file");
 198     serial = qemu_opt_get(opts, "serial");
 199
 200     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 201         pstrcpy(devname, sizeof(devname), buf);
 202         if (!strcmp(buf, "ide")) {
 203             type = IF_IDE;
 204             max_devs = MAX_IDE_DEVS;
 205         } else if (!strcmp(buf, "scsi")) {
 206             type = IF_SCSI;
 207             max_devs = MAX_SCSI_DEVS;
 208         } else if (!strcmp(buf, "floppy")) {
 209             type = IF_FLOPPY;
 210             max_devs = 0;
 211         } else if (!strcmp(buf, "pflash")) {
 212             type = IF_PFLASH;
 213             max_devs = 0;
 214         } else if (!strcmp(buf, "mtd")) {
 215             type = IF_MTD;
 216             max_devs = 0;
 217         } else if (!strcmp(buf, "sd")) {
 218             type = IF_SD;
 219             max_devs = 0;
 220         } else if (!strcmp(buf, "virtio")) {
 221             type = IF_VIRTIO;
 222             max_devs = 0;
 223         } else if (!strcmp(buf, "xen")) {
 224             type = IF_XEN;
 225             max_devs = 0;
 226         } else if (!strcmp(buf, "none")) {
 227             type = IF_NONE;
 228             max_devs = 0;
 229         } else {
 230             error_report("unsupported bus type '%s'", buf);
 231             return NULL;
 232         }
 233     }
 234
 235     if (cyls || heads || secs) {
 236         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 237             error_report("invalid physical cyls number");
 238             return NULL;
 239         }
 240         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 241             error_report("invalid physical heads number");
 242             return NULL;
 243         }
 244         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 245             error_report("invalid physical secs number");
 246             return NULL;
 247         }
 248     }
 249
 250     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 251         if (!cyls) {
 252             error_report("'%s' trans must be used with cyls,heads and secs",
 253                          buf);
 254             return NULL;
 255         }
 256         if (!strcmp(buf, "none"))
 257             translation = BIOS_ATA_TRANSLATION_NONE;
 258         else if (!strcmp(buf, "lba"))
 259             translation = BIOS_ATA_TRANSLATION_LBA;
 260         else if (!strcmp(buf, "auto"))
 261             translation = BIOS_ATA_TRANSLATION_AUTO;
 262         else {
 263             error_report("'%s' invalid translation type", buf);
 264             return NULL;
 265         }
 266     }
 267
 268     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 269         if (!strcmp(buf, "disk")) {
 270             media = MEDIA_DISK;
 271         } else if (!strcmp(buf, "cdrom")) {
 272             if (cyls || secs || heads) {
 273                 error_report("'%s' invalid physical CHS format", buf);
 274                 return NULL;
 275             }
 276             media = MEDIA_CDROM;
 277         } else {
 278             error_report("'%s' invalid media", buf);
 279             return NULL;
 280         }
 281     }
 282
 283     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 284         if (!strcmp(buf, "off") || !strcmp(buf, "none")) {
 285             bdrv_flags |= BDRV_O_NOCACHE;
 286         } else if (!strcmp(buf, "writeback")) {
 287             bdrv_flags |= BDRV_O_CACHE_WB;
 288         } else if (!strcmp(buf, "unsafe")) {
 289             bdrv_flags |= BDRV_O_CACHE_WB;
 290             bdrv_flags |= BDRV_O_NO_FLUSH;
 291         } else if (!strcmp(buf, "writethrough")) {
 292             /* this is the default */
 293         } else {
 294            error_report("invalid cache option");
 295            return NULL;
 296         }
 297     }
 298
 299 #ifdef CONFIG_LINUX_AIO
 300     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 301         if (!strcmp(buf, "native")) {
 302             bdrv_flags |= BDRV_O_NATIVE_AIO;
 303         } else if (!strcmp(buf, "threads")) {
 304             /* this is the default */
 305         } else {
 306            error_report("invalid aio option");
 307            return NULL;
 308         }
 309     }
 310 #endif
 311
 312     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 313        if (strcmp(buf, "?") == 0) {
 314            error_printf("Supported formats:");
 315            bdrv_iterate_format(bdrv_format_print, NULL);
 316            error_printf("\n");
 317            return NULL;
 318         }
 319         drv = bdrv_find_whitelisted_format(buf);
 320         if (!drv) {
 321             error_report("'%s' invalid format", buf);
 322             return NULL;
 323         }
 324     }
 325
 326     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 327     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 328         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 329             error_report("werror is not supported by this bus type");
 330             return NULL;
 331         }
 332
 333         on_write_error = parse_block_error_action(buf, 0);
 334         if (on_write_error < 0) {
 335             return NULL;
 336         }
 337     }
 338
 339     on_read_error = BLOCK_ERR_REPORT;
 340     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 341         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 342             error_report("rerror is not supported by this bus type");
 343             return NULL;
 344         }
 345
 346         on_read_error = parse_block_error_action(buf, 1);
 347         if (on_read_error < 0) {
 348             return NULL;
 349         }
 350     }
 351
 352     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 353         if (type != IF_VIRTIO) {
 354             error_report("addr is not supported by this bus type");
 355             return NULL;
 356         }
 357     }
 358
 359     /* compute bus and unit according index */
 360
 361     if (index != -1) {
 362         if (bus_id != 0 || unit_id != -1) {
 363             error_report("index cannot be used with bus and unit");
 364             return NULL;
 365         }
 366         if (max_devs == 0)
 367         {
 368             unit_id = index;
 369             bus_id = 0;
 370         } else {
 371             unit_id = index % max_devs;
 372             bus_id = index / max_devs;
 373         }
 374     }
 375
 376     /* if user doesn't specify a unit_id,
 377      * try to find the first free
 378      */
 379
 380     if (unit_id == -1) {
 381        unit_id = 0;
 382        while (drive_get(type, bus_id, unit_id) != NULL) {
 383            unit_id++;
 384            if (max_devs && unit_id >= max_devs) {
 385                unit_id -= max_devs;
 386                bus_id++;
 387            }
 388        }
 389     }
 390
 391     /* check unit id */
 392
 393     if (max_devs && unit_id >= max_devs) {
 394         error_report("unit %d too big (max is %d)",
 395                      unit_id, max_devs - 1);
 396         return NULL;
 397     }
 398
 399     /*
 400      * ignore multiple definitions
 401      */
 402
 403     if (drive_get(type, bus_id, unit_id) != NULL) {
 404         *fatal_error = 0;
 405         return NULL;
 406     }
 407
 408     /* init */
 409
 410     dinfo = qemu_mallocz(sizeof(*dinfo));
 411     if ((buf = qemu_opts_id(opts)) != NULL) {
 412         dinfo->id = qemu_strdup(buf);
 413     } else {
 414         /* no id supplied -> create one */
 415         dinfo->id = qemu_mallocz(32);
 416         if (type == IF_IDE || type == IF_SCSI)
 417             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 418         if (max_devs)
 419             snprintf(dinfo->id, 32, "%s%i%s%i",
 420                      devname, bus_id, mediastr, unit_id);
 421         else
 422             snprintf(dinfo->id, 32, "%s%s%i",
 423                      devname, mediastr, unit_id);
 424     }
 425     dinfo->bdrv = bdrv_new(dinfo->id);
 426     dinfo->devaddr = devaddr;
 427     dinfo->type = type;
 428     dinfo->bus = bus_id;
 429     dinfo->unit = unit_id;
 430     dinfo->opts = opts;
 431     if (serial)
 432         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 433     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 434
 435     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 436
 437     switch(type) {
 438     case IF_IDE:
 439     case IF_SCSI:
 440     case IF_XEN:
 441     case IF_NONE:
 442         switch(media) {
 443         case MEDIA_DISK:
 444             if (cyls != 0) {
 445                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 446                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 447             }
 448             break;
 449         case MEDIA_CDROM:
 450             bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_CDROM);
 451             break;
 452         }
 453         break;
 454     case IF_SD:
 455         /* FIXME: This isn't really a floppy, but it's a reasonable
 456            approximation.  */
 457     case IF_FLOPPY:
 458         bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_FLOPPY);
 459         break;
 460     case IF_PFLASH:
 461     case IF_MTD:
 462         break;
 463     case IF_VIRTIO:
 464         /* add virtio block device */
 465         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 466         qemu_opt_set(opts, "driver", "virtio-blk-pci");
 467         qemu_opt_set(opts, "drive", dinfo->id);
 468         if (devaddr)
 469             qemu_opt_set(opts, "addr", devaddr);
 470         break;
 471     case IF_COUNT:
 472         abort();
 473     }
 474     if (!file || !*file) {
 475         *fatal_error = 0;
 476         return NULL;
 477     }
 478     if (snapshot) {
 479         /* always use cache=unsafe with snapshot */
 480         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 481         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 482     }
 483
 484     if (media == MEDIA_CDROM) {
 485         /* CDROM is fine for any interface, don't check.  */
 486         ro = 1;
 487     } else if (ro == 1) {
 488         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 489             error_report("readonly not supported by this bus type");
 490             return NULL;
 491         }
 492     }
 493
 494     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 495
 496     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 497     if (ret < 0) {
 498         error_report("could not open disk image %s: %s",
 499                      file, strerror(-ret));
 500         return NULL;
 501     }
 502
 503     if (bdrv_key_required(dinfo->bdrv))
 504         autostart = 0;
 505     *fatal_error = 0;
 506     return dinfo;
 507 }
 508
 509 void do_commit(Monitor *mon, const QDict *qdict)
 510 {
 511     const char *device = qdict_get_str(qdict, "device");
 512     BlockDriverState *bs;
 513
 514     if (!strcmp(device, "all")) {
 515         bdrv_commit_all();
 516     } else {
 517         bs = bdrv_find(device);
 518         if (!bs) {
 519             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 520             return;
 521         }
 522         bdrv_commit(bs);
 523     }
 524 }
 525
 526 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
 527 {
 528     const char *device = qdict_get_str(qdict, "device");
 529     const char *filename = qdict_get_try_str(qdict, "snapshot_file");
 530     const char *format = qdict_get_try_str(qdict, "format");
 531     BlockDriverState *bs;
 532     BlockDriver *drv, *proto_drv;
 533     int ret = 0;
 534     int flags;
 535
 536     if (!filename) {
 537         qerror_report(QERR_MISSING_PARAMETER, "snapshot_file");
 538         ret = -1;
 539         goto out;
 540     }
 541
 542     bs = bdrv_find(device);
 543     if (!bs) {
 544         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 545         ret = -1;
 546         goto out;
 547     }
 548
 549     if (!format) {
 550         format = "qcow2";
 551     }
 552
 553     drv = bdrv_find_format(format);
 554     if (!drv) {
 555         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 556         ret = -1;
 557         goto out;
 558     }
 559
 560     proto_drv = bdrv_find_protocol(filename);
 561     if (!proto_drv) {
 562         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 563         ret = -1;
 564         goto out;
 565     }
 566
 567     ret = bdrv_img_create(filename, format, bs->filename,
 568                           bs->drv->format_name, NULL, -1, bs->open_flags);
 569     if (ret) {
 570         goto out;
 571     }
 572
 573     qemu_aio_flush();
 574     bdrv_flush(bs);
 575
 576     flags = bs->open_flags;
 577     bdrv_close(bs);
 578     ret = bdrv_open(bs, filename, flags, drv);
 579     /*
 580      * If reopening the image file we just created fails, we really
 581      * are in trouble :(
 582      */
 583     if (ret != 0) {
 584         abort();
 585     }
 586 out:
 587     if (ret) {
 588         ret = -1;
 589     }
 590
 591     return ret;
 592 }
 593
 594 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
 595 {
 596     if (!force) {
 597         if (!bdrv_is_removable(bs)) {
 598             qerror_report(QERR_DEVICE_NOT_REMOVABLE,
 599                            bdrv_get_device_name(bs));
 600             return -1;
 601         }
 602         if (bdrv_is_locked(bs)) {
 603             qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 604             return -1;
 605         }
 606     }
 607     bdrv_close(bs);
 608     return 0;
 609 }
 610
 611 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 612 {
 613     BlockDriverState *bs;
 614     int force = qdict_get_try_bool(qdict, "force", 0);
 615     const char *filename = qdict_get_str(qdict, "device");
 616
 617     bs = bdrv_find(filename);
 618     if (!bs) {
 619         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
 620         return -1;
 621     }
 622     return eject_device(mon, bs, force);
 623 }
 624
 625 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 626                         QObject **ret_data)
 627 {
 628     BlockDriverState *bs;
 629     int err;
 630
 631     bs = bdrv_find(qdict_get_str(qdict, "device"));
 632     if (!bs) {
 633         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
 634         return -1;
 635     }
 636
 637     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
 638     if (err == -EINVAL) {
 639         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 640         return -1;
 641     } else if (err < 0) {
 642         qerror_report(QERR_INVALID_PASSWORD);
 643         return -1;
 644     }
 645
 646     return 0;
 647 }
 648
 649 int do_change_block(Monitor *mon, const char *device,
 650                     const char *filename, const char *fmt)
 651 {
 652     BlockDriverState *bs;
 653     BlockDriver *drv = NULL;
 654     int bdrv_flags;
 655
 656     bs = bdrv_find(device);
 657     if (!bs) {
 658         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 659         return -1;
 660     }
 661     if (fmt) {
 662         drv = bdrv_find_whitelisted_format(fmt);
 663         if (!drv) {
 664             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
 665             return -1;
 666         }
 667     }
 668     if (eject_device(mon, bs, 0) < 0) {
 669         return -1;
 670     }
 671     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 672     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 673     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 674         qerror_report(QERR_OPEN_FILE_FAILED, filename);
 675         return -1;
 676     }
 677     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 678 }
 679
 680 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 681 {
 682     const char *id = qdict_get_str(qdict, "id");
 683     BlockDriverState *bs;
 684     BlockDriverState **ptr;
 685     Property *prop;
 686
 687     bs = bdrv_find(id);
 688     if (!bs) {
 689         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 690         return -1;
 691     }
 692
 693     /* quiesce block driver; prevent further io */
 694     qemu_aio_flush();
 695     bdrv_flush(bs);
 696     bdrv_close(bs);
 697
 698     /* clean up guest state from pointing to host resource by
 699      * finding and removing DeviceState "drive" property */
 700     if (bs->peer) {
 701         for (prop = bs->peer->info->props; prop && prop->name; prop++) {
 702             if (prop->info->type == PROP_TYPE_DRIVE) {
 703                 ptr = qdev_get_prop_ptr(bs->peer, prop);
 704                 if (*ptr == bs) {
 705                     bdrv_detach(bs, bs->peer);
 706                     *ptr = NULL;
 707                     break;
 708                 }
 709             }
 710         }
 711     }
 712
 713     /* clean up host side */
 714     drive_uninit(drive_get_by_blockdev(bs));
 715
 716     return 0;
 717 }
 718
 719 /*
 720  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
 721  * existing QERR_ macro mess is cleaned up.  A good example for better
 722  * error reports can be found in the qemu-img resize code.
 723  */
 724 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
 725 {
 726     const char *device = qdict_get_str(qdict, "device");
 727     int64_t size = qdict_get_int(qdict, "size");
 728     BlockDriverState *bs;
 729
 730     bs = bdrv_find(device);
 731     if (!bs) {
 732         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 733         return -1;
 734     }
 735
 736     if (size < 0) {
 737         qerror_report(QERR_UNDEFINED_ERROR);
 738         return -1;
 739     }
 740
 741     if (bdrv_truncate(bs, size)) {
 742         qerror_report(QERR_UNDEFINED_ERROR);
 743         return -1;
 744     }
 745
 746     return 0;
 747 }