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 DriveInfo *extboot_drive = NULL;
  21
  22 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
  23
  24 static const char *const if_name[IF_COUNT] = {
  25     [IF_NONE] = "none",
  26     [IF_IDE] = "ide",
  27     [IF_SCSI] = "scsi",
  28     [IF_FLOPPY] = "floppy",
  29     [IF_PFLASH] = "pflash",
  30     [IF_MTD] = "mtd",
  31     [IF_SD] = "sd",
  32     [IF_VIRTIO] = "virtio",
  33     [IF_XEN] = "xen",
  34 };
  35
  36 static const int if_max_devs[IF_COUNT] = {
  37     /*
  38      * Do not change these numbers!  They govern how drive option
  39      * index maps to unit and bus.  That mapping is ABI.
  40      *
  41      * All controllers used to imlement if=T drives need to support
  42      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
  43      * Otherwise, some index values map to "impossible" bus, unit
  44      * values.
  45      *
  46      * For instance, if you change [IF_SCSI] to 255, -drive
  47      * if=scsi,index=12 no longer means bus=1,unit=5, but
  48      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
  49      * the drive can't be set up.  Regression.
  50      */
  51     [IF_IDE] = 2,
  52     [IF_SCSI] = 7,
  53 };
  54
  55 /*
  56  * We automatically delete the drive when a device using it gets
  57  * unplugged.  Questionable feature, but we can't just drop it.
  58  * Device models call blockdev_mark_auto_del() to schedule the
  59  * automatic deletion, and generic qdev code calls blockdev_auto_del()
  60  * when deletion is actually safe.
  61  */
  62 void blockdev_mark_auto_del(BlockDriverState *bs)
  63 {
  64     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  65
  66     if (dinfo) {
  67         dinfo->auto_del = 1;
  68     }
  69 }
  70
  71 void blockdev_auto_del(BlockDriverState *bs)
  72 {
  73     DriveInfo *dinfo = drive_get_by_blockdev(bs);
  74
  75     if (dinfo && dinfo->auto_del) {
  76         drive_put_ref(dinfo);
  77     }
  78 }
  79
  80 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
  81 {
  82     int max_devs = if_max_devs[type];
  83     return max_devs ? index / max_devs : 0;
  84 }
  85
  86 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
  87 {
  88     int max_devs = if_max_devs[type];
  89     return max_devs ? index % max_devs : index;
  90 }
  91
  92 QemuOpts *drive_def(const char *optstr)
  93 {
  94     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
  95 }
  96
  97 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
  98                     const char *optstr)
  99 {
 100     QemuOpts *opts;
 101     char buf[32];
 102
 103     opts = drive_def(optstr);
 104     if (!opts) {
 105         return NULL;
 106     }
 107     if (type != IF_DEFAULT) {
 108         qemu_opt_set(opts, "if", if_name[type]);
 109     }
 110     if (index >= 0) {
 111         snprintf(buf, sizeof(buf), "%d", index);
 112         qemu_opt_set(opts, "index", buf);
 113     }
 114     if (file)
 115         qemu_opt_set(opts, "file", file);
 116     return opts;
 117 }
 118
 119 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
 120 {
 121     DriveInfo *dinfo;
 122
 123     /* seek interface, bus and unit */
 124
 125     QTAILQ_FOREACH(dinfo, &drives, next) {
 126         if (dinfo->type == type &&
 127             dinfo->bus == bus &&
 128             dinfo->unit == unit)
 129             return dinfo;
 130     }
 131
 132     return NULL;
 133 }
 134
 135 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
 136 {
 137     return drive_get(type,
 138                      drive_index_to_bus_id(type, index),
 139                      drive_index_to_unit_id(type, index));
 140 }
 141
 142 int drive_get_max_bus(BlockInterfaceType type)
 143 {
 144     int max_bus;
 145     DriveInfo *dinfo;
 146
 147     max_bus = -1;
 148     QTAILQ_FOREACH(dinfo, &drives, next) {
 149         if(dinfo->type == type &&
 150            dinfo->bus > max_bus)
 151             max_bus = dinfo->bus;
 152     }
 153     return max_bus;
 154 }
 155
 156 /* Get a block device.  This should only be used for single-drive devices
 157    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
 158    appropriate bus.  */
 159 DriveInfo *drive_get_next(BlockInterfaceType type)
 160 {
 161     static int next_block_unit[IF_COUNT];
 162
 163     return drive_get(type, 0, next_block_unit[type]++);
 164 }
 165
 166 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
 167 {
 168     DriveInfo *dinfo;
 169
 170     QTAILQ_FOREACH(dinfo, &drives, next) {
 171         if (dinfo->bdrv == bs) {
 172             return dinfo;
 173         }
 174     }
 175     return NULL;
 176 }
 177
 178 static void bdrv_format_print(void *opaque, const char *name)
 179 {
 180     error_printf(" %s", name);
 181 }
 182
 183 static void drive_uninit(DriveInfo *dinfo)
 184 {
 185     qemu_opts_del(dinfo->opts);
 186     bdrv_delete(dinfo->bdrv);
 187     qemu_free(dinfo->id);
 188     QTAILQ_REMOVE(&drives, dinfo, next);
 189     qemu_free(dinfo);
 190 }
 191
 192 void drive_put_ref(DriveInfo *dinfo)
 193 {
 194     assert(dinfo->refcount);
 195     if (--dinfo->refcount == 0) {
 196         drive_uninit(dinfo);
 197     }
 198 }
 199
 200 void drive_get_ref(DriveInfo *dinfo)
 201 {
 202     dinfo->refcount++;
 203 }
 204
 205 static int parse_block_error_action(const char *buf, int is_read)
 206 {
 207     if (!strcmp(buf, "ignore")) {
 208         return BLOCK_ERR_IGNORE;
 209     } else if (!is_read && !strcmp(buf, "enospc")) {
 210         return BLOCK_ERR_STOP_ENOSPC;
 211     } else if (!strcmp(buf, "stop")) {
 212         return BLOCK_ERR_STOP_ANY;
 213     } else if (!strcmp(buf, "report")) {
 214         return BLOCK_ERR_REPORT;
 215     } else {
 216         error_report("'%s' invalid %s error action",
 217                      buf, is_read ? "read" : "write");
 218         return -1;
 219     }
 220 }
 221
 222 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 223 {
 224     const char *buf;
 225     const char *file = NULL;
 226     char devname[128];
 227     const char *serial;
 228     const char *mediastr = "";
 229     BlockInterfaceType type;
 230     enum { MEDIA_DISK, MEDIA_CDROM } media;
 231     int bus_id, unit_id;
 232     int cyls, heads, secs, translation;
 233     BlockDriver *drv = NULL;
 234     int max_devs;
 235     int index;
 236     int ro = 0;
 237     int bdrv_flags = 0;
 238     int on_read_error, on_write_error;
 239     const char *devaddr;
 240     DriveInfo *dinfo;
 241     int is_extboot = 0;
 242     int snapshot = 0;
 243     int ret;
 244
 245     translation = BIOS_ATA_TRANSLATION_AUTO;
 246
 247     if (default_to_scsi) {
 248         type = IF_SCSI;
 249         pstrcpy(devname, sizeof(devname), "scsi");
 250     } else {
 251         type = IF_IDE;
 252         pstrcpy(devname, sizeof(devname), "ide");
 253     }
 254     media = MEDIA_DISK;
 255
 256     /* extract parameters */
 257     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 258     unit_id = qemu_opt_get_number(opts, "unit", -1);
 259     index   = qemu_opt_get_number(opts, "index", -1);
 260
 261     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 262     heads = qemu_opt_get_number(opts, "heads", 0);
 263     secs  = qemu_opt_get_number(opts, "secs", 0);
 264
 265     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 266     ro = qemu_opt_get_bool(opts, "readonly", 0);
 267
 268     file = qemu_opt_get(opts, "file");
 269     serial = qemu_opt_get(opts, "serial");
 270
 271     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 272         pstrcpy(devname, sizeof(devname), buf);
 273         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 274             ;
 275         if (type == IF_COUNT) {
 276             error_report("unsupported bus type '%s'", buf);
 277             return NULL;
 278         }
 279     }
 280     max_devs = if_max_devs[type];
 281
 282     if (cyls || heads || secs) {
 283         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 284             error_report("invalid physical cyls number");
 285             return NULL;
 286         }
 287         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 288             error_report("invalid physical heads number");
 289             return NULL;
 290         }
 291         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 292             error_report("invalid physical secs number");
 293             return NULL;
 294         }
 295     }
 296
 297     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 298         if (!cyls) {
 299             error_report("'%s' trans must be used with cyls,heads and secs",
 300                          buf);
 301             return NULL;
 302         }
 303         if (!strcmp(buf, "none"))
 304             translation = BIOS_ATA_TRANSLATION_NONE;
 305         else if (!strcmp(buf, "lba"))
 306             translation = BIOS_ATA_TRANSLATION_LBA;
 307         else if (!strcmp(buf, "auto"))
 308             translation = BIOS_ATA_TRANSLATION_AUTO;
 309         else {
 310             error_report("'%s' invalid translation type", buf);
 311             return NULL;
 312         }
 313     }
 314
 315     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 316         if (!strcmp(buf, "disk")) {
 317             media = MEDIA_DISK;
 318         } else if (!strcmp(buf, "cdrom")) {
 319             if (cyls || secs || heads) {
 320                 error_report("'%s' invalid physical CHS format", buf);
 321                 return NULL;
 322             }
 323             media = MEDIA_CDROM;
 324         } else {
 325             error_report("'%s' invalid media", buf);
 326             return NULL;
 327         }
 328     }
 329
 330     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 331         if (!strcmp(buf, "off") || !strcmp(buf, "none")) {
 332             bdrv_flags |= BDRV_O_NOCACHE;
 333         } else if (!strcmp(buf, "writeback")) {
 334             bdrv_flags |= BDRV_O_CACHE_WB;
 335         } else if (!strcmp(buf, "unsafe")) {
 336             bdrv_flags |= BDRV_O_CACHE_WB;
 337             bdrv_flags |= BDRV_O_NO_FLUSH;
 338         } else if (!strcmp(buf, "writethrough")) {
 339             /* this is the default */
 340         } else {
 341            error_report("invalid cache option");
 342            return NULL;
 343         }
 344     }
 345
 346 #ifdef CONFIG_LINUX_AIO
 347     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 348         if (!strcmp(buf, "native")) {
 349             bdrv_flags |= BDRV_O_NATIVE_AIO;
 350         } else if (!strcmp(buf, "threads")) {
 351             /* this is the default */
 352         } else {
 353            error_report("invalid aio option");
 354            return NULL;
 355         }
 356     }
 357 #endif
 358
 359     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 360        if (strcmp(buf, "?") == 0) {
 361            error_printf("Supported formats:");
 362            bdrv_iterate_format(bdrv_format_print, NULL);
 363            error_printf("\n");
 364            return NULL;
 365         }
 366         drv = bdrv_find_whitelisted_format(buf);
 367         if (!drv) {
 368             error_report("'%s' invalid format", buf);
 369             return NULL;
 370         }
 371     }
 372
 373     is_extboot = qemu_opt_get_bool(opts, "boot", 0);
 374     if (is_extboot && extboot_drive) {
 375         fprintf(stderr, "qemu: two bootable drives specified\n");
 376         return NULL;
 377     }
 378
 379     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 380     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 381         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 382             error_report("werror is not supported by this bus type");
 383             return NULL;
 384         }
 385
 386         on_write_error = parse_block_error_action(buf, 0);
 387         if (on_write_error < 0) {
 388             return NULL;
 389         }
 390     }
 391
 392     on_read_error = BLOCK_ERR_REPORT;
 393     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 394         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 395             error_report("rerror is not supported by this bus type");
 396             return NULL;
 397         }
 398
 399         on_read_error = parse_block_error_action(buf, 1);
 400         if (on_read_error < 0) {
 401             return NULL;
 402         }
 403     }
 404
 405     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 406         if (type != IF_VIRTIO) {
 407             error_report("addr is not supported by this bus type");
 408             return NULL;
 409         }
 410     }
 411
 412     /* compute bus and unit according index */
 413
 414     if (index != -1) {
 415         if (bus_id != 0 || unit_id != -1) {
 416             error_report("index cannot be used with bus and unit");
 417             return NULL;
 418         }
 419         bus_id = drive_index_to_bus_id(type, index);
 420         unit_id = drive_index_to_unit_id(type, index);
 421     }
 422
 423     /* if user doesn't specify a unit_id,
 424      * try to find the first free
 425      */
 426
 427     if (unit_id == -1) {
 428        unit_id = 0;
 429        while (drive_get(type, bus_id, unit_id) != NULL) {
 430            unit_id++;
 431            if (max_devs && unit_id >= max_devs) {
 432                unit_id -= max_devs;
 433                bus_id++;
 434            }
 435        }
 436     }
 437
 438     /* check unit id */
 439
 440     if (max_devs && unit_id >= max_devs) {
 441         error_report("unit %d too big (max is %d)",
 442                      unit_id, max_devs - 1);
 443         return NULL;
 444     }
 445
 446     /*
 447      * catch multiple definitions
 448      */
 449
 450     if (drive_get(type, bus_id, unit_id) != NULL) {
 451         error_report("drive with bus=%d, unit=%d (index=%d) exists",
 452                      bus_id, unit_id, index);
 453         return NULL;
 454     }
 455
 456     /* init */
 457
 458     dinfo = qemu_mallocz(sizeof(*dinfo));
 459     if ((buf = qemu_opts_id(opts)) != NULL) {
 460         dinfo->id = qemu_strdup(buf);
 461     } else {
 462         /* no id supplied -> create one */
 463         dinfo->id = qemu_mallocz(32);
 464         if (type == IF_IDE || type == IF_SCSI)
 465             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 466         if (max_devs)
 467             snprintf(dinfo->id, 32, "%s%i%s%i",
 468                      devname, bus_id, mediastr, unit_id);
 469         else
 470             snprintf(dinfo->id, 32, "%s%s%i",
 471                      devname, mediastr, unit_id);
 472     }
 473     dinfo->bdrv = bdrv_new(dinfo->id);
 474     dinfo->devaddr = devaddr;
 475     dinfo->type = type;
 476     dinfo->bus = bus_id;
 477     dinfo->unit = unit_id;
 478     dinfo->opts = opts;
 479     dinfo->refcount = 1;
 480     if (serial)
 481         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 482     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 483
 484     if (is_extboot) {
 485         extboot_drive = dinfo;
 486     }
 487
 488     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 489
 490     switch(type) {
 491     case IF_IDE:
 492     case IF_SCSI:
 493     case IF_XEN:
 494     case IF_NONE:
 495         switch(media) {
 496         case MEDIA_DISK:
 497             if (cyls != 0) {
 498                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 499                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 500             }
 501             break;
 502         case MEDIA_CDROM:
 503             bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_CDROM);
 504             break;
 505         }
 506         break;
 507     case IF_SD:
 508         /* FIXME: This isn't really a floppy, but it's a reasonable
 509            approximation.  */
 510     case IF_FLOPPY:
 511         bdrv_set_type_hint(dinfo->bdrv, BDRV_TYPE_FLOPPY);
 512         break;
 513     case IF_PFLASH:
 514     case IF_MTD:
 515         break;
 516     case IF_VIRTIO:
 517         /* add virtio block device */
 518         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 519         qemu_opt_set(opts, "driver", "virtio-blk");
 520         qemu_opt_set(opts, "drive", dinfo->id);
 521         if (devaddr)
 522             qemu_opt_set(opts, "addr", devaddr);
 523         break;
 524     default:
 525         abort();
 526     }
 527     if (!file || !*file) {
 528         return dinfo;
 529     }
 530     if (snapshot) {
 531         /* always use cache=unsafe with snapshot */
 532         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 533         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 534     }
 535
 536     if (media == MEDIA_CDROM) {
 537         /* CDROM is fine for any interface, don't check.  */
 538         ro = 1;
 539     } else if (ro == 1) {
 540         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 541             error_report("readonly not supported by this bus type");
 542             goto err;
 543         }
 544     }
 545
 546     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 547
 548     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 549     if (ret < 0) {
 550         error_report("could not open disk image %s: %s",
 551                      file, strerror(-ret));
 552         goto err;
 553     }
 554
 555     if (bdrv_key_required(dinfo->bdrv))
 556         autostart = 0;
 557     return dinfo;
 558
 559 err:
 560     bdrv_delete(dinfo->bdrv);
 561     qemu_free(dinfo->id);
 562     QTAILQ_REMOVE(&drives, dinfo, next);
 563     qemu_free(dinfo);
 564     return NULL;
 565 }
 566
 567 void do_commit(Monitor *mon, const QDict *qdict)
 568 {
 569     const char *device = qdict_get_str(qdict, "device");
 570     BlockDriverState *bs;
 571
 572     if (!strcmp(device, "all")) {
 573         bdrv_commit_all();
 574     } else {
 575         bs = bdrv_find(device);
 576         if (!bs) {
 577             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 578             return;
 579         }
 580         bdrv_commit(bs);
 581     }
 582 }
 583
 584 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
 585 {
 586     const char *device = qdict_get_str(qdict, "device");
 587     const char *filename = qdict_get_try_str(qdict, "snapshot_file");
 588     const char *format = qdict_get_try_str(qdict, "format");
 589     BlockDriverState *bs;
 590     BlockDriver *drv, *old_drv, *proto_drv;
 591     int ret = 0;
 592     int flags;
 593     char old_filename[1024];
 594
 595     if (!filename) {
 596         qerror_report(QERR_MISSING_PARAMETER, "snapshot_file");
 597         ret = -1;
 598         goto out;
 599     }
 600
 601     bs = bdrv_find(device);
 602     if (!bs) {
 603         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 604         ret = -1;
 605         goto out;
 606     }
 607
 608     pstrcpy(old_filename, sizeof(old_filename), bs->filename);
 609
 610     old_drv = bs->drv;
 611     flags = bs->open_flags;
 612
 613     if (!format) {
 614         format = "qcow2";
 615     }
 616
 617     drv = bdrv_find_format(format);
 618     if (!drv) {
 619         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 620         ret = -1;
 621         goto out;
 622     }
 623
 624     proto_drv = bdrv_find_protocol(filename);
 625     if (!proto_drv) {
 626         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
 627         ret = -1;
 628         goto out;
 629     }
 630
 631     ret = bdrv_img_create(filename, format, bs->filename,
 632                           bs->drv->format_name, NULL, -1, flags);
 633     if (ret) {
 634         goto out;
 635     }
 636
 637     qemu_aio_flush();
 638     bdrv_flush(bs);
 639
 640     bdrv_close(bs);
 641     ret = bdrv_open(bs, filename, flags, drv);
 642     /*
 643      * If reopening the image file we just created fails, fall back
 644      * and try to re-open the original image. If that fails too, we
 645      * are in serious trouble.
 646      */
 647     if (ret != 0) {
 648         ret = bdrv_open(bs, old_filename, flags, old_drv);
 649         if (ret != 0) {
 650             qerror_report(QERR_OPEN_FILE_FAILED, old_filename);
 651         } else {
 652             qerror_report(QERR_OPEN_FILE_FAILED, filename);
 653         }
 654     }
 655 out:
 656     if (ret) {
 657         ret = -1;
 658     }
 659
 660     return ret;
 661 }
 662
 663 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
 664 {
 665     if (!force) {
 666         if (!bdrv_is_removable(bs)) {
 667             qerror_report(QERR_DEVICE_NOT_REMOVABLE,
 668                            bdrv_get_device_name(bs));
 669             return -1;
 670         }
 671         if (bdrv_is_locked(bs)) {
 672             qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 673             return -1;
 674         }
 675     }
 676     bdrv_close(bs);
 677     return 0;
 678 }
 679
 680 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
 681 {
 682     BlockDriverState *bs;
 683     int force = qdict_get_try_bool(qdict, "force", 0);
 684     const char *filename = qdict_get_str(qdict, "device");
 685
 686     bs = bdrv_find(filename);
 687     if (!bs) {
 688         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
 689         return -1;
 690     }
 691     return eject_device(mon, bs, force);
 692 }
 693
 694 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
 695                         QObject **ret_data)
 696 {
 697     BlockDriverState *bs;
 698     int err;
 699
 700     bs = bdrv_find(qdict_get_str(qdict, "device"));
 701     if (!bs) {
 702         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
 703         return -1;
 704     }
 705
 706     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
 707     if (err == -EINVAL) {
 708         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 709         return -1;
 710     } else if (err < 0) {
 711         qerror_report(QERR_INVALID_PASSWORD);
 712         return -1;
 713     }
 714
 715     return 0;
 716 }
 717
 718 int do_change_block(Monitor *mon, const char *device,
 719                     const char *filename, const char *fmt)
 720 {
 721     BlockDriverState *bs;
 722     BlockDriver *drv = NULL;
 723     int bdrv_flags;
 724
 725     bs = bdrv_find(device);
 726     if (!bs) {
 727         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 728         return -1;
 729     }
 730     if (fmt) {
 731         drv = bdrv_find_whitelisted_format(fmt);
 732         if (!drv) {
 733             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
 734             return -1;
 735         }
 736     }
 737     if (eject_device(mon, bs, 0) < 0) {
 738         return -1;
 739     }
 740     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 741     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 742     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 743         qerror_report(QERR_OPEN_FILE_FAILED, filename);
 744         return -1;
 745     }
 746     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
 747 }
 748
 749 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 750 {
 751     const char *id = qdict_get_str(qdict, "id");
 752     BlockDriverState *bs;
 753
 754     bs = bdrv_find(id);
 755     if (!bs) {
 756         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 757         return -1;
 758     }
 759     if (bdrv_in_use(bs)) {
 760         qerror_report(QERR_DEVICE_IN_USE, id);
 761         return -1;
 762     }
 763
 764     /* quiesce block driver; prevent further io */
 765     qemu_aio_flush();
 766     bdrv_flush(bs);
 767     bdrv_close(bs);
 768
 769     /* if we have a device associated with this BlockDriverState (bs->peer)
 770      * then we need to make the drive anonymous until the device
 771      * can be removed.  If this is a drive with no device backing
 772      * then we can just get rid of the block driver state right here.
 773      */
 774     if (bs->peer) {
 775         bdrv_make_anon(bs);
 776     } else {
 777         drive_uninit(drive_get_by_blockdev(bs));
 778     }
 779
 780     return 0;
 781 }
 782
 783 /*
 784  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
 785  * existing QERR_ macro mess is cleaned up.  A good example for better
 786  * error reports can be found in the qemu-img resize code.
 787  */
 788 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
 789 {
 790     const char *device = qdict_get_str(qdict, "device");
 791     int64_t size = qdict_get_int(qdict, "size");
 792     BlockDriverState *bs;
 793
 794     bs = bdrv_find(device);
 795     if (!bs) {
 796         qerror_report(QERR_DEVICE_NOT_FOUND, device);
 797         return -1;
 798     }
 799
 800     if (size < 0) {
 801         qerror_report(QERR_UNDEFINED_ERROR);
 802         return -1;
 803     }
 804
 805     if (bdrv_truncate(bs, size)) {
 806         qerror_report(QERR_UNDEFINED_ERROR);
 807         return -1;
 808     }
 809
 810     return 0;
 811 }