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 "qemu-objects.h"
  17 #include "sysemu.h"
  18 #include "block_int.h"
  19 #include "qmp-commands.h"
  20 #include "trace.h"
  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     g_free(dinfo->id);
 188     QTAILQ_REMOVE(&drives, dinfo, next);
 189     g_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 typedef struct {
 206     QEMUBH *bh;
 207     DriveInfo *dinfo;
 208 } DrivePutRefBH;
 209
 210 static void drive_put_ref_bh(void *opaque)
 211 {
 212     DrivePutRefBH *s = opaque;
 213
 214     drive_put_ref(s->dinfo);
 215     qemu_bh_delete(s->bh);
 216     g_free(s);
 217 }
 218
 219 /*
 220  * Release a drive reference in a BH
 221  *
 222  * It is not possible to use drive_put_ref() from a callback function when the
 223  * callers still need the drive.  In such cases we schedule a BH to release the
 224  * reference.
 225  */
 226 static void drive_put_ref_bh_schedule(DriveInfo *dinfo)
 227 {
 228     DrivePutRefBH *s;
 229
 230     s = g_new(DrivePutRefBH, 1);
 231     s->bh = qemu_bh_new(drive_put_ref_bh, s);
 232     s->dinfo = dinfo;
 233     qemu_bh_schedule(s->bh);
 234 }
 235
 236 static int parse_block_error_action(const char *buf, int is_read)
 237 {
 238     if (!strcmp(buf, "ignore")) {
 239         return BLOCK_ERR_IGNORE;
 240     } else if (!is_read && !strcmp(buf, "enospc")) {
 241         return BLOCK_ERR_STOP_ENOSPC;
 242     } else if (!strcmp(buf, "stop")) {
 243         return BLOCK_ERR_STOP_ANY;
 244     } else if (!strcmp(buf, "report")) {
 245         return BLOCK_ERR_REPORT;
 246     } else {
 247         error_report("'%s' invalid %s error action",
 248                      buf, is_read ? "read" : "write");
 249         return -1;
 250     }
 251 }
 252
 253 static bool do_check_io_limits(BlockIOLimit *io_limits)
 254 {
 255     bool bps_flag;
 256     bool iops_flag;
 257
 258     assert(io_limits);
 259
 260     bps_flag  = (io_limits->bps[BLOCK_IO_LIMIT_TOTAL] != 0)
 261                  && ((io_limits->bps[BLOCK_IO_LIMIT_READ] != 0)
 262                  || (io_limits->bps[BLOCK_IO_LIMIT_WRITE] != 0));
 263     iops_flag = (io_limits->iops[BLOCK_IO_LIMIT_TOTAL] != 0)
 264                  && ((io_limits->iops[BLOCK_IO_LIMIT_READ] != 0)
 265                  || (io_limits->iops[BLOCK_IO_LIMIT_WRITE] != 0));
 266     if (bps_flag || iops_flag) {
 267         return false;
 268     }
 269
 270     return true;
 271 }
 272
 273 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 274 {
 275     const char *buf;
 276     const char *file = NULL;
 277     char devname[128];
 278     const char *serial;
 279     const char *mediastr = "";
 280     BlockInterfaceType type;
 281     enum { MEDIA_DISK, MEDIA_CDROM } media;
 282     int bus_id, unit_id;
 283     int cyls, heads, secs, translation;
 284     BlockDriver *drv = NULL;
 285     int max_devs;
 286     int index;
 287     int ro = 0;
 288     int bdrv_flags = 0;
 289     int on_read_error, on_write_error;
 290     const char *devaddr;
 291     DriveInfo *dinfo;
 292     BlockIOLimit io_limits;
 293     int snapshot = 0;
 294     bool copy_on_read;
 295     int ret;
 296
 297     translation = BIOS_ATA_TRANSLATION_AUTO;
 298     media = MEDIA_DISK;
 299
 300     /* extract parameters */
 301     bus_id  = qemu_opt_get_number(opts, "bus", 0);
 302     unit_id = qemu_opt_get_number(opts, "unit", -1);
 303     index   = qemu_opt_get_number(opts, "index", -1);
 304
 305     cyls  = qemu_opt_get_number(opts, "cyls", 0);
 306     heads = qemu_opt_get_number(opts, "heads", 0);
 307     secs  = qemu_opt_get_number(opts, "secs", 0);
 308
 309     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
 310     ro = qemu_opt_get_bool(opts, "readonly", 0);
 311     copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false);
 312
 313     file = qemu_opt_get(opts, "file");
 314     serial = qemu_opt_get(opts, "serial");
 315
 316     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
 317         pstrcpy(devname, sizeof(devname), buf);
 318         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
 319             ;
 320         if (type == IF_COUNT) {
 321             error_report("unsupported bus type '%s'", buf);
 322             return NULL;
 323         }
 324     } else {
 325         type = default_to_scsi ? IF_SCSI : IF_IDE;
 326         pstrcpy(devname, sizeof(devname), if_name[type]);
 327     }
 328
 329     max_devs = if_max_devs[type];
 330
 331     if (cyls || heads || secs) {
 332         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
 333             error_report("invalid physical cyls number");
 334             return NULL;
 335         }
 336         if (heads < 1 || (type == IF_IDE && heads > 16)) {
 337             error_report("invalid physical heads number");
 338             return NULL;
 339         }
 340         if (secs < 1 || (type == IF_IDE && secs > 63)) {
 341             error_report("invalid physical secs number");
 342             return NULL;
 343         }
 344     }
 345
 346     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
 347         if (!cyls) {
 348             error_report("'%s' trans must be used with cyls, heads and secs",
 349                          buf);
 350             return NULL;
 351         }
 352         if (!strcmp(buf, "none"))
 353             translation = BIOS_ATA_TRANSLATION_NONE;
 354         else if (!strcmp(buf, "lba"))
 355             translation = BIOS_ATA_TRANSLATION_LBA;
 356         else if (!strcmp(buf, "auto"))
 357             translation = BIOS_ATA_TRANSLATION_AUTO;
 358         else {
 359             error_report("'%s' invalid translation type", buf);
 360             return NULL;
 361         }
 362     }
 363
 364     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
 365         if (!strcmp(buf, "disk")) {
 366             media = MEDIA_DISK;
 367         } else if (!strcmp(buf, "cdrom")) {
 368             if (cyls || secs || heads) {
 369                 error_report("CHS can't be set with media=%s", buf);
 370                 return NULL;
 371             }
 372             media = MEDIA_CDROM;
 373         } else {
 374             error_report("'%s' invalid media", buf);
 375             return NULL;
 376         }
 377     }
 378
 379     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
 380         if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
 381             error_report("invalid cache option");
 382             return NULL;
 383         }
 384     }
 385
 386 #ifdef CONFIG_LINUX_AIO
 387     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
 388         if (!strcmp(buf, "native")) {
 389             bdrv_flags |= BDRV_O_NATIVE_AIO;
 390         } else if (!strcmp(buf, "threads")) {
 391             /* this is the default */
 392         } else {
 393            error_report("invalid aio option");
 394            return NULL;
 395         }
 396     }
 397 #endif
 398
 399     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
 400        if (strcmp(buf, "?") == 0) {
 401            error_printf("Supported formats:");
 402            bdrv_iterate_format(bdrv_format_print, NULL);
 403            error_printf("\n");
 404            return NULL;
 405         }
 406         drv = bdrv_find_whitelisted_format(buf);
 407         if (!drv) {
 408             error_report("'%s' invalid format", buf);
 409             return NULL;
 410         }
 411     }
 412
 413     /* disk I/O throttling */
 414     io_limits.bps[BLOCK_IO_LIMIT_TOTAL]  =
 415                            qemu_opt_get_number(opts, "bps", 0);
 416     io_limits.bps[BLOCK_IO_LIMIT_READ]   =
 417                            qemu_opt_get_number(opts, "bps_rd", 0);
 418     io_limits.bps[BLOCK_IO_LIMIT_WRITE]  =
 419                            qemu_opt_get_number(opts, "bps_wr", 0);
 420     io_limits.iops[BLOCK_IO_LIMIT_TOTAL] =
 421                            qemu_opt_get_number(opts, "iops", 0);
 422     io_limits.iops[BLOCK_IO_LIMIT_READ]  =
 423                            qemu_opt_get_number(opts, "iops_rd", 0);
 424     io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
 425                            qemu_opt_get_number(opts, "iops_wr", 0);
 426
 427     if (!do_check_io_limits(&io_limits)) {
 428         error_report("bps(iops) and bps_rd/bps_wr(iops_rd/iops_wr) "
 429                      "cannot be used at the same time");
 430         return NULL;
 431     }
 432
 433     if (qemu_opt_get(opts, "boot") != NULL) {
 434         fprintf(stderr, "qemu-kvm: boot=on|off is deprecated and will be "
 435                 "ignored. Future versions will reject this parameter. Please "
 436                 "update your scripts.\n");
 437     }
 438
 439     on_write_error = BLOCK_ERR_STOP_ENOSPC;
 440     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
 441         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
 442             error_report("werror is not supported by this bus type");
 443             return NULL;
 444         }
 445
 446         on_write_error = parse_block_error_action(buf, 0);
 447         if (on_write_error < 0) {
 448             return NULL;
 449         }
 450     }
 451
 452     on_read_error = BLOCK_ERR_REPORT;
 453     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
 454         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
 455             error_report("rerror is not supported by this bus type");
 456             return NULL;
 457         }
 458
 459         on_read_error = parse_block_error_action(buf, 1);
 460         if (on_read_error < 0) {
 461             return NULL;
 462         }
 463     }
 464
 465     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
 466         if (type != IF_VIRTIO) {
 467             error_report("addr is not supported by this bus type");
 468             return NULL;
 469         }
 470     }
 471
 472     /* compute bus and unit according index */
 473
 474     if (index != -1) {
 475         if (bus_id != 0 || unit_id != -1) {
 476             error_report("index cannot be used with bus and unit");
 477             return NULL;
 478         }
 479         bus_id = drive_index_to_bus_id(type, index);
 480         unit_id = drive_index_to_unit_id(type, index);
 481     }
 482
 483     /* if user doesn't specify a unit_id,
 484      * try to find the first free
 485      */
 486
 487     if (unit_id == -1) {
 488        unit_id = 0;
 489        while (drive_get(type, bus_id, unit_id) != NULL) {
 490            unit_id++;
 491            if (max_devs && unit_id >= max_devs) {
 492                unit_id -= max_devs;
 493                bus_id++;
 494            }
 495        }
 496     }
 497
 498     /* check unit id */
 499
 500     if (max_devs && unit_id >= max_devs) {
 501         error_report("unit %d too big (max is %d)",
 502                      unit_id, max_devs - 1);
 503         return NULL;
 504     }
 505
 506     /*
 507      * catch multiple definitions
 508      */
 509
 510     if (drive_get(type, bus_id, unit_id) != NULL) {
 511         error_report("drive with bus=%d, unit=%d (index=%d) exists",
 512                      bus_id, unit_id, index);
 513         return NULL;
 514     }
 515
 516     /* init */
 517
 518     dinfo = g_malloc0(sizeof(*dinfo));
 519     if ((buf = qemu_opts_id(opts)) != NULL) {
 520         dinfo->id = g_strdup(buf);
 521     } else {
 522         /* no id supplied -> create one */
 523         dinfo->id = g_malloc0(32);
 524         if (type == IF_IDE || type == IF_SCSI)
 525             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
 526         if (max_devs)
 527             snprintf(dinfo->id, 32, "%s%i%s%i",
 528                      devname, bus_id, mediastr, unit_id);
 529         else
 530             snprintf(dinfo->id, 32, "%s%s%i",
 531                      devname, mediastr, unit_id);
 532     }
 533     dinfo->bdrv = bdrv_new(dinfo->id);
 534     dinfo->devaddr = devaddr;
 535     dinfo->type = type;
 536     dinfo->bus = bus_id;
 537     dinfo->unit = unit_id;
 538     dinfo->opts = opts;
 539     dinfo->refcount = 1;
 540     if (serial)
 541         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
 542     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
 543
 544     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
 545
 546     /* disk I/O throttling */
 547     bdrv_set_io_limits(dinfo->bdrv, &io_limits);
 548
 549     switch(type) {
 550     case IF_IDE:
 551     case IF_SCSI:
 552     case IF_XEN:
 553     case IF_NONE:
 554         switch(media) {
 555         case MEDIA_DISK:
 556             if (cyls != 0) {
 557                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
 558                 bdrv_set_translation_hint(dinfo->bdrv, translation);
 559             }
 560             break;
 561         case MEDIA_CDROM:
 562             dinfo->media_cd = 1;
 563             break;
 564         }
 565         break;
 566     case IF_SD:
 567     case IF_FLOPPY:
 568     case IF_PFLASH:
 569     case IF_MTD:
 570         break;
 571     case IF_VIRTIO:
 572         /* add virtio block device */
 573         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
 574         qemu_opt_set(opts, "driver", "virtio-blk");
 575         qemu_opt_set(opts, "drive", dinfo->id);
 576         if (devaddr)
 577             qemu_opt_set(opts, "addr", devaddr);
 578         break;
 579     default:
 580         abort();
 581     }
 582     if (!file || !*file) {
 583         return dinfo;
 584     }
 585     if (snapshot) {
 586         /* always use cache=unsafe with snapshot */
 587         bdrv_flags &= ~BDRV_O_CACHE_MASK;
 588         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
 589     }
 590
 591     if (copy_on_read) {
 592         bdrv_flags |= BDRV_O_COPY_ON_READ;
 593     }
 594
 595     if (media == MEDIA_CDROM) {
 596         /* CDROM is fine for any interface, don't check.  */
 597         ro = 1;
 598     } else if (ro == 1) {
 599         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
 600             error_report("readonly not supported by this bus type");
 601             goto err;
 602         }
 603     }
 604
 605     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 606
 607     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
 608     if (ret < 0) {
 609         error_report("could not open disk image %s: %s",
 610                      file, strerror(-ret));
 611         goto err;
 612     }
 613
 614     if (bdrv_key_required(dinfo->bdrv))
 615         autostart = 0;
 616     return dinfo;
 617
 618 err:
 619     bdrv_delete(dinfo->bdrv);
 620     g_free(dinfo->id);
 621     QTAILQ_REMOVE(&drives, dinfo, next);
 622     g_free(dinfo);
 623     return NULL;
 624 }
 625
 626 void do_commit(Monitor *mon, const QDict *qdict)
 627 {
 628     const char *device = qdict_get_str(qdict, "device");
 629     BlockDriverState *bs;
 630
 631     if (!strcmp(device, "all")) {
 632         bdrv_commit_all();
 633     } else {
 634         int ret;
 635
 636         bs = bdrv_find(device);
 637         if (!bs) {
 638             qerror_report(QERR_DEVICE_NOT_FOUND, device);
 639             return;
 640         }
 641         ret = bdrv_commit(bs);
 642         if (ret == -EBUSY) {
 643             qerror_report(QERR_DEVICE_IN_USE, device);
 644             return;
 645         }
 646     }
 647 }
 648
 649 void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
 650                                 bool has_format, const char *format,
 651                                 Error **errp)
 652 {
 653     BlockDriverState *bs;
 654     BlockDriver *drv, *old_drv, *proto_drv;
 655     int ret = 0;
 656     int flags;
 657     char old_filename[1024];
 658
 659     bs = bdrv_find(device);
 660     if (!bs) {
 661         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 662         return;
 663     }
 664     if (bdrv_in_use(bs)) {
 665         error_set(errp, QERR_DEVICE_IN_USE, device);
 666         return;
 667     }
 668
 669     pstrcpy(old_filename, sizeof(old_filename), bs->filename);
 670
 671     old_drv = bs->drv;
 672     flags = bs->open_flags;
 673
 674     if (!has_format) {
 675         format = "qcow2";
 676     }
 677
 678     drv = bdrv_find_format(format);
 679     if (!drv) {
 680         error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 681         return;
 682     }
 683
 684     proto_drv = bdrv_find_protocol(snapshot_file);
 685     if (!proto_drv) {
 686         error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 687         return;
 688     }
 689
 690     ret = bdrv_img_create(snapshot_file, format, bs->filename,
 691                           bs->drv->format_name, NULL, -1, flags);
 692     if (ret) {
 693         error_set(errp, QERR_UNDEFINED_ERROR);
 694         return;
 695     }
 696
 697     bdrv_drain_all();
 698     bdrv_flush(bs);
 699
 700     bdrv_close(bs);
 701     ret = bdrv_open(bs, snapshot_file, flags, drv);
 702     /*
 703      * If reopening the image file we just created fails, fall back
 704      * and try to re-open the original image. If that fails too, we
 705      * are in serious trouble.
 706      */
 707     if (ret != 0) {
 708         ret = bdrv_open(bs, old_filename, flags, old_drv);
 709         if (ret != 0) {
 710             error_set(errp, QERR_OPEN_FILE_FAILED, old_filename);
 711         } else {
 712             error_set(errp, QERR_OPEN_FILE_FAILED, snapshot_file);
 713         }
 714     }
 715 }
 716
 717 static void eject_device(BlockDriverState *bs, int force, Error **errp)
 718 {
 719     if (bdrv_in_use(bs)) {
 720         error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
 721         return;
 722     }
 723     if (!bdrv_dev_has_removable_media(bs)) {
 724         error_set(errp, QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
 725         return;
 726     }
 727
 728     if (bdrv_dev_is_medium_locked(bs) && !bdrv_dev_is_tray_open(bs)) {
 729         bdrv_dev_eject_request(bs, force);
 730         if (!force) {
 731             error_set(errp, QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
 732             return;
 733         }
 734     }
 735
 736     bdrv_close(bs);
 737 }
 738
 739 void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
 740 {
 741     BlockDriverState *bs;
 742
 743     bs = bdrv_find(device);
 744     if (!bs) {
 745         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 746         return;
 747     }
 748
 749     eject_device(bs, force, errp);
 750 }
 751
 752 void qmp_block_passwd(const char *device, const char *password, Error **errp)
 753 {
 754     BlockDriverState *bs;
 755     int err;
 756
 757     bs = bdrv_find(device);
 758     if (!bs) {
 759         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 760         return;
 761     }
 762
 763     err = bdrv_set_key(bs, password);
 764     if (err == -EINVAL) {
 765         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 766         return;
 767     } else if (err < 0) {
 768         error_set(errp, QERR_INVALID_PASSWORD);
 769         return;
 770     }
 771 }
 772
 773 static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
 774                                     int bdrv_flags, BlockDriver *drv,
 775                                     const char *password, Error **errp)
 776 {
 777     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
 778         error_set(errp, QERR_OPEN_FILE_FAILED, filename);
 779         return;
 780     }
 781
 782     if (bdrv_key_required(bs)) {
 783         if (password) {
 784             if (bdrv_set_key(bs, password) < 0) {
 785                 error_set(errp, QERR_INVALID_PASSWORD);
 786             }
 787         } else {
 788             error_set(errp, QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs),
 789                       bdrv_get_encrypted_filename(bs));
 790         }
 791     } else if (password) {
 792         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
 793     }
 794 }
 795
 796 void qmp_change_blockdev(const char *device, const char *filename,
 797                          bool has_format, const char *format, Error **errp)
 798 {
 799     BlockDriverState *bs;
 800     BlockDriver *drv = NULL;
 801     int bdrv_flags;
 802     Error *err = NULL;
 803
 804     bs = bdrv_find(device);
 805     if (!bs) {
 806         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 807         return;
 808     }
 809
 810     if (format) {
 811         drv = bdrv_find_whitelisted_format(format);
 812         if (!drv) {
 813             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
 814             return;
 815         }
 816     }
 817
 818     eject_device(bs, 0, &err);
 819     if (error_is_set(&err)) {
 820         error_propagate(errp, err);
 821         return;
 822     }
 823
 824     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
 825     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
 826
 827     qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, errp);
 828 }
 829
 830 /* throttling disk I/O limits */
 831 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
 832                                int64_t bps_wr, int64_t iops, int64_t iops_rd,
 833                                int64_t iops_wr, Error **errp)
 834 {
 835     BlockIOLimit io_limits;
 836     BlockDriverState *bs;
 837
 838     bs = bdrv_find(device);
 839     if (!bs) {
 840         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 841         return;
 842     }
 843
 844     io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
 845     io_limits.bps[BLOCK_IO_LIMIT_READ]  = bps_rd;
 846     io_limits.bps[BLOCK_IO_LIMIT_WRITE] = bps_wr;
 847     io_limits.iops[BLOCK_IO_LIMIT_TOTAL]= iops;
 848     io_limits.iops[BLOCK_IO_LIMIT_READ] = iops_rd;
 849     io_limits.iops[BLOCK_IO_LIMIT_WRITE]= iops_wr;
 850
 851     if (!do_check_io_limits(&io_limits)) {
 852         error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
 853         return;
 854     }
 855
 856     bs->io_limits = io_limits;
 857     bs->slice_time = BLOCK_IO_SLICE_TIME;
 858
 859     if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
 860         bdrv_io_limits_enable(bs);
 861     } else if (bs->io_limits_enabled && !bdrv_io_limits_enabled(bs)) {
 862         bdrv_io_limits_disable(bs);
 863     } else {
 864         if (bs->block_timer) {
 865             qemu_mod_timer(bs->block_timer, qemu_get_clock_ns(vm_clock));
 866         }
 867     }
 868 }
 869
 870 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
 871 {
 872     const char *id = qdict_get_str(qdict, "id");
 873     BlockDriverState *bs;
 874
 875     bs = bdrv_find(id);
 876     if (!bs) {
 877         qerror_report(QERR_DEVICE_NOT_FOUND, id);
 878         return -1;
 879     }
 880     if (bdrv_in_use(bs)) {
 881         qerror_report(QERR_DEVICE_IN_USE, id);
 882         return -1;
 883     }
 884
 885     /* quiesce block driver; prevent further io */
 886     bdrv_drain_all();
 887     bdrv_flush(bs);
 888     bdrv_close(bs);
 889
 890     /* if we have a device attached to this BlockDriverState
 891      * then we need to make the drive anonymous until the device
 892      * can be removed.  If this is a drive with no device backing
 893      * then we can just get rid of the block driver state right here.
 894      */
 895     if (bdrv_get_attached_dev(bs)) {
 896         bdrv_make_anon(bs);
 897     } else {
 898         drive_uninit(drive_get_by_blockdev(bs));
 899     }
 900
 901     return 0;
 902 }
 903
 904 void qmp_block_resize(const char *device, int64_t size, Error **errp)
 905 {
 906     BlockDriverState *bs;
 907
 908     bs = bdrv_find(device);
 909     if (!bs) {
 910         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 911         return;
 912     }
 913
 914     if (size < 0) {
 915         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
 916         return;
 917     }
 918
 919     switch (bdrv_truncate(bs, size)) {
 920     case 0:
 921         break;
 922     case -ENOMEDIUM:
 923         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
 924         break;
 925     case -ENOTSUP:
 926         error_set(errp, QERR_UNSUPPORTED);
 927         break;
 928     case -EACCES:
 929         error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 930         break;
 931     case -EBUSY:
 932         error_set(errp, QERR_DEVICE_IN_USE, device);
 933         break;
 934     default:
 935         error_set(errp, QERR_UNDEFINED_ERROR);
 936         break;
 937     }
 938 }
 939
 940 static QObject *qobject_from_block_job(BlockJob *job)
 941 {
 942     return qobject_from_jsonf("{ 'type': %s,"
 943                               "'device': %s,"
 944                               "'len': %" PRId64 ","
 945                               "'offset': %" PRId64 ","
 946                               "'speed': %" PRId64 " }",
 947                               job->job_type->job_type,
 948                               bdrv_get_device_name(job->bs),
 949                               job->len,
 950                               job->offset,
 951                               job->speed);
 952 }
 953
 954 static void block_stream_cb(void *opaque, int ret)
 955 {
 956     BlockDriverState *bs = opaque;
 957     QObject *obj;
 958
 959     trace_block_stream_cb(bs, bs->job, ret);
 960
 961     assert(bs->job);
 962     obj = qobject_from_block_job(bs->job);
 963     if (ret < 0) {
 964         QDict *dict = qobject_to_qdict(obj);
 965         qdict_put(dict, "error", qstring_from_str(strerror(-ret)));
 966     }
 967
 968     if (block_job_is_cancelled(bs->job)) {
 969         monitor_protocol_event(QEVENT_BLOCK_JOB_CANCELLED, obj);
 970     } else {
 971         monitor_protocol_event(QEVENT_BLOCK_JOB_COMPLETED, obj);
 972     }
 973     qobject_decref(obj);
 974
 975     drive_put_ref_bh_schedule(drive_get_by_blockdev(bs));
 976 }
 977
 978 void qmp_block_stream(const char *device, bool has_base,
 979                       const char *base, Error **errp)
 980 {
 981     BlockDriverState *bs;
 982     BlockDriverState *base_bs = NULL;
 983     int ret;
 984
 985     bs = bdrv_find(device);
 986     if (!bs) {
 987         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 988         return;
 989     }
 990
 991     if (base) {
 992         base_bs = bdrv_find_backing_image(bs, base);
 993         if (base_bs == NULL) {
 994             error_set(errp, QERR_BASE_NOT_FOUND, base);
 995             return;
 996         }
 997     }
 998
 999     ret = stream_start(bs, base_bs, base, block_stream_cb, bs);
1000     if (ret < 0) {
1001         switch (ret) {
1002         case -EBUSY:
1003             error_set(errp, QERR_DEVICE_IN_USE, device);
1004             return;
1005         default:
1006             error_set(errp, QERR_NOT_SUPPORTED);
1007             return;
1008         }
1009     }
1010
1011     /* Grab a reference so hotplug does not delete the BlockDriverState from
1012      * underneath us.
1013      */
1014     drive_get_ref(drive_get_by_blockdev(bs));
1015
1016     trace_qmp_block_stream(bs, bs->job);
1017 }
1018
1019 static BlockJob *find_block_job(const char *device)
1020 {
1021     BlockDriverState *bs;
1022
1023     bs = bdrv_find(device);
1024     if (!bs || !bs->job) {
1025         return NULL;
1026     }
1027     return bs->job;
1028 }
1029
1030 void qmp_block_job_set_speed(const char *device, int64_t value, Error **errp)
1031 {
1032     BlockJob *job = find_block_job(device);
1033
1034     if (!job) {
1035         error_set(errp, QERR_DEVICE_NOT_ACTIVE, device);
1036         return;
1037     }
1038
1039     if (block_job_set_speed(job, value) < 0) {
1040         error_set(errp, QERR_NOT_SUPPORTED);
1041     }
1042 }
1043
1044 void qmp_block_job_cancel(const char *device, Error **errp)
1045 {
1046     BlockJob *job = find_block_job(device);
1047
1048     if (!job) {
1049         error_set(errp, QERR_DEVICE_NOT_ACTIVE, device);
1050         return;
1051     }
1052
1053     trace_qmp_block_job_cancel(job);
1054     block_job_cancel(job);
1055 }
1056
1057 static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
1058 {
1059     BlockJobInfoList **prev = opaque;
1060     BlockJob *job = bs->job;
1061
1062     if (job) {
1063         BlockJobInfoList *elem;
1064         BlockJobInfo *info = g_new(BlockJobInfo, 1);
1065         *info = (BlockJobInfo){
1066             .type   = g_strdup(job->job_type->job_type),
1067             .device = g_strdup(bdrv_get_device_name(bs)),
1068             .len    = job->len,
1069             .offset = job->offset,
1070             .speed  = job->speed,
1071         };
1072
1073         elem = g_new0(BlockJobInfoList, 1);
1074         elem->value = info;
1075
1076         (*prev)->next = elem;
1077         *prev = elem;
1078     }
1079 }
1080
1081 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
1082 {
1083     /* Dummy is a fake list element for holding the head pointer */
1084     BlockJobInfoList dummy = {};
1085     BlockJobInfoList *prev = &dummy;
1086     bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
1087     return dummy.next;
1088 }