xref: /openbmc/qemu/blockdev.c (revision 54d50be6)
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 "block_int.h"
18 
19 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
20 
21 static const char *const if_name[IF_COUNT] = {
22     [IF_NONE] = "none",
23     [IF_IDE] = "ide",
24     [IF_SCSI] = "scsi",
25     [IF_FLOPPY] = "floppy",
26     [IF_PFLASH] = "pflash",
27     [IF_MTD] = "mtd",
28     [IF_SD] = "sd",
29     [IF_VIRTIO] = "virtio",
30     [IF_XEN] = "xen",
31 };
32 
33 static const int if_max_devs[IF_COUNT] = {
34     /*
35      * Do not change these numbers!  They govern how drive option
36      * index maps to unit and bus.  That mapping is ABI.
37      *
38      * All controllers used to imlement if=T drives need to support
39      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
40      * Otherwise, some index values map to "impossible" bus, unit
41      * values.
42      *
43      * For instance, if you change [IF_SCSI] to 255, -drive
44      * if=scsi,index=12 no longer means bus=1,unit=5, but
45      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
46      * the drive can't be set up.  Regression.
47      */
48     [IF_IDE] = 2,
49     [IF_SCSI] = 7,
50 };
51 
52 /*
53  * We automatically delete the drive when a device using it gets
54  * unplugged.  Questionable feature, but we can't just drop it.
55  * Device models call blockdev_mark_auto_del() to schedule the
56  * automatic deletion, and generic qdev code calls blockdev_auto_del()
57  * when deletion is actually safe.
58  */
59 void blockdev_mark_auto_del(BlockDriverState *bs)
60 {
61     DriveInfo *dinfo = drive_get_by_blockdev(bs);
62 
63     if (dinfo) {
64         dinfo->auto_del = 1;
65     }
66 }
67 
68 void blockdev_auto_del(BlockDriverState *bs)
69 {
70     DriveInfo *dinfo = drive_get_by_blockdev(bs);
71 
72     if (dinfo && dinfo->auto_del) {
73         drive_put_ref(dinfo);
74     }
75 }
76 
77 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
78 {
79     int max_devs = if_max_devs[type];
80     return max_devs ? index / max_devs : 0;
81 }
82 
83 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
84 {
85     int max_devs = if_max_devs[type];
86     return max_devs ? index % max_devs : index;
87 }
88 
89 QemuOpts *drive_def(const char *optstr)
90 {
91     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
92 }
93 
94 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
95                     const char *optstr)
96 {
97     QemuOpts *opts;
98     char buf[32];
99 
100     opts = drive_def(optstr);
101     if (!opts) {
102         return NULL;
103     }
104     if (type != IF_DEFAULT) {
105         qemu_opt_set(opts, "if", if_name[type]);
106     }
107     if (index >= 0) {
108         snprintf(buf, sizeof(buf), "%d", index);
109         qemu_opt_set(opts, "index", buf);
110     }
111     if (file)
112         qemu_opt_set(opts, "file", file);
113     return opts;
114 }
115 
116 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
117 {
118     DriveInfo *dinfo;
119 
120     /* seek interface, bus and unit */
121 
122     QTAILQ_FOREACH(dinfo, &drives, next) {
123         if (dinfo->type == type &&
124 	    dinfo->bus == bus &&
125 	    dinfo->unit == unit)
126             return dinfo;
127     }
128 
129     return NULL;
130 }
131 
132 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
133 {
134     return drive_get(type,
135                      drive_index_to_bus_id(type, index),
136                      drive_index_to_unit_id(type, index));
137 }
138 
139 int drive_get_max_bus(BlockInterfaceType type)
140 {
141     int max_bus;
142     DriveInfo *dinfo;
143 
144     max_bus = -1;
145     QTAILQ_FOREACH(dinfo, &drives, next) {
146         if(dinfo->type == type &&
147            dinfo->bus > max_bus)
148             max_bus = dinfo->bus;
149     }
150     return max_bus;
151 }
152 
153 /* Get a block device.  This should only be used for single-drive devices
154    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
155    appropriate bus.  */
156 DriveInfo *drive_get_next(BlockInterfaceType type)
157 {
158     static int next_block_unit[IF_COUNT];
159 
160     return drive_get(type, 0, next_block_unit[type]++);
161 }
162 
163 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
164 {
165     DriveInfo *dinfo;
166 
167     QTAILQ_FOREACH(dinfo, &drives, next) {
168         if (dinfo->bdrv == bs) {
169             return dinfo;
170         }
171     }
172     return NULL;
173 }
174 
175 static void bdrv_format_print(void *opaque, const char *name)
176 {
177     error_printf(" %s", name);
178 }
179 
180 static void drive_uninit(DriveInfo *dinfo)
181 {
182     qemu_opts_del(dinfo->opts);
183     bdrv_delete(dinfo->bdrv);
184     g_free(dinfo->id);
185     QTAILQ_REMOVE(&drives, dinfo, next);
186     g_free(dinfo);
187 }
188 
189 void drive_put_ref(DriveInfo *dinfo)
190 {
191     assert(dinfo->refcount);
192     if (--dinfo->refcount == 0) {
193         drive_uninit(dinfo);
194     }
195 }
196 
197 void drive_get_ref(DriveInfo *dinfo)
198 {
199     dinfo->refcount++;
200 }
201 
202 static int parse_block_error_action(const char *buf, int is_read)
203 {
204     if (!strcmp(buf, "ignore")) {
205         return BLOCK_ERR_IGNORE;
206     } else if (!is_read && !strcmp(buf, "enospc")) {
207         return BLOCK_ERR_STOP_ENOSPC;
208     } else if (!strcmp(buf, "stop")) {
209         return BLOCK_ERR_STOP_ANY;
210     } else if (!strcmp(buf, "report")) {
211         return BLOCK_ERR_REPORT;
212     } else {
213         error_report("'%s' invalid %s error action",
214                      buf, is_read ? "read" : "write");
215         return -1;
216     }
217 }
218 
219 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
220 {
221     const char *buf;
222     const char *file = NULL;
223     char devname[128];
224     const char *serial;
225     const char *mediastr = "";
226     BlockInterfaceType type;
227     enum { MEDIA_DISK, MEDIA_CDROM } media;
228     int bus_id, unit_id;
229     int cyls, heads, secs, translation;
230     BlockDriver *drv = NULL;
231     int max_devs;
232     int index;
233     int ro = 0;
234     int bdrv_flags = 0;
235     int on_read_error, on_write_error;
236     const char *devaddr;
237     DriveInfo *dinfo;
238     int snapshot = 0;
239     int ret;
240 
241     translation = BIOS_ATA_TRANSLATION_AUTO;
242     media = MEDIA_DISK;
243 
244     /* extract parameters */
245     bus_id  = qemu_opt_get_number(opts, "bus", 0);
246     unit_id = qemu_opt_get_number(opts, "unit", -1);
247     index   = qemu_opt_get_number(opts, "index", -1);
248 
249     cyls  = qemu_opt_get_number(opts, "cyls", 0);
250     heads = qemu_opt_get_number(opts, "heads", 0);
251     secs  = qemu_opt_get_number(opts, "secs", 0);
252 
253     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
254     ro = qemu_opt_get_bool(opts, "readonly", 0);
255 
256     file = qemu_opt_get(opts, "file");
257     serial = qemu_opt_get(opts, "serial");
258 
259     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
260         pstrcpy(devname, sizeof(devname), buf);
261         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
262             ;
263         if (type == IF_COUNT) {
264             error_report("unsupported bus type '%s'", buf);
265             return NULL;
266 	}
267     } else {
268         type = default_to_scsi ? IF_SCSI : IF_IDE;
269         pstrcpy(devname, sizeof(devname), if_name[type]);
270     }
271 
272     max_devs = if_max_devs[type];
273 
274     if (cyls || heads || secs) {
275         if (cyls < 1 || (type == IF_IDE && cyls > 16383)) {
276             error_report("invalid physical cyls number");
277 	    return NULL;
278 	}
279         if (heads < 1 || (type == IF_IDE && heads > 16)) {
280             error_report("invalid physical heads number");
281 	    return NULL;
282 	}
283         if (secs < 1 || (type == IF_IDE && secs > 63)) {
284             error_report("invalid physical secs number");
285 	    return NULL;
286 	}
287     }
288 
289     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
290         if (!cyls) {
291             error_report("'%s' trans must be used with cyls, heads and secs",
292                          buf);
293             return NULL;
294         }
295         if (!strcmp(buf, "none"))
296             translation = BIOS_ATA_TRANSLATION_NONE;
297         else if (!strcmp(buf, "lba"))
298             translation = BIOS_ATA_TRANSLATION_LBA;
299         else if (!strcmp(buf, "auto"))
300             translation = BIOS_ATA_TRANSLATION_AUTO;
301 	else {
302             error_report("'%s' invalid translation type", buf);
303 	    return NULL;
304 	}
305     }
306 
307     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
308         if (!strcmp(buf, "disk")) {
309 	    media = MEDIA_DISK;
310 	} else if (!strcmp(buf, "cdrom")) {
311             if (cyls || secs || heads) {
312                 error_report("CHS can't be set with media=%s", buf);
313 	        return NULL;
314             }
315 	    media = MEDIA_CDROM;
316 	} else {
317 	    error_report("'%s' invalid media", buf);
318 	    return NULL;
319 	}
320     }
321 
322     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
323         if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
324             error_report("invalid cache option");
325             return NULL;
326         }
327     }
328 
329 #ifdef CONFIG_LINUX_AIO
330     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
331         if (!strcmp(buf, "native")) {
332             bdrv_flags |= BDRV_O_NATIVE_AIO;
333         } else if (!strcmp(buf, "threads")) {
334             /* this is the default */
335         } else {
336            error_report("invalid aio option");
337            return NULL;
338         }
339     }
340 #endif
341 
342     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
343        if (strcmp(buf, "?") == 0) {
344            error_printf("Supported formats:");
345            bdrv_iterate_format(bdrv_format_print, NULL);
346            error_printf("\n");
347            return NULL;
348         }
349         drv = bdrv_find_whitelisted_format(buf);
350         if (!drv) {
351             error_report("'%s' invalid format", buf);
352             return NULL;
353         }
354     }
355 
356     on_write_error = BLOCK_ERR_STOP_ENOSPC;
357     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
358         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
359             error_report("werror is not supported by this bus type");
360             return NULL;
361         }
362 
363         on_write_error = parse_block_error_action(buf, 0);
364         if (on_write_error < 0) {
365             return NULL;
366         }
367     }
368 
369     on_read_error = BLOCK_ERR_REPORT;
370     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
371         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
372             error_report("rerror is not supported by this bus type");
373             return NULL;
374         }
375 
376         on_read_error = parse_block_error_action(buf, 1);
377         if (on_read_error < 0) {
378             return NULL;
379         }
380     }
381 
382     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
383         if (type != IF_VIRTIO) {
384             error_report("addr is not supported by this bus type");
385             return NULL;
386         }
387     }
388 
389     /* compute bus and unit according index */
390 
391     if (index != -1) {
392         if (bus_id != 0 || unit_id != -1) {
393             error_report("index cannot be used with bus and unit");
394             return NULL;
395         }
396         bus_id = drive_index_to_bus_id(type, index);
397         unit_id = drive_index_to_unit_id(type, index);
398     }
399 
400     /* if user doesn't specify a unit_id,
401      * try to find the first free
402      */
403 
404     if (unit_id == -1) {
405        unit_id = 0;
406        while (drive_get(type, bus_id, unit_id) != NULL) {
407            unit_id++;
408            if (max_devs && unit_id >= max_devs) {
409                unit_id -= max_devs;
410                bus_id++;
411            }
412        }
413     }
414 
415     /* check unit id */
416 
417     if (max_devs && unit_id >= max_devs) {
418         error_report("unit %d too big (max is %d)",
419                      unit_id, max_devs - 1);
420         return NULL;
421     }
422 
423     /*
424      * catch multiple definitions
425      */
426 
427     if (drive_get(type, bus_id, unit_id) != NULL) {
428         error_report("drive with bus=%d, unit=%d (index=%d) exists",
429                      bus_id, unit_id, index);
430         return NULL;
431     }
432 
433     /* init */
434 
435     dinfo = g_malloc0(sizeof(*dinfo));
436     if ((buf = qemu_opts_id(opts)) != NULL) {
437         dinfo->id = g_strdup(buf);
438     } else {
439         /* no id supplied -> create one */
440         dinfo->id = g_malloc0(32);
441         if (type == IF_IDE || type == IF_SCSI)
442             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
443         if (max_devs)
444             snprintf(dinfo->id, 32, "%s%i%s%i",
445                      devname, bus_id, mediastr, unit_id);
446         else
447             snprintf(dinfo->id, 32, "%s%s%i",
448                      devname, mediastr, unit_id);
449     }
450     dinfo->bdrv = bdrv_new(dinfo->id);
451     dinfo->devaddr = devaddr;
452     dinfo->type = type;
453     dinfo->bus = bus_id;
454     dinfo->unit = unit_id;
455     dinfo->opts = opts;
456     dinfo->refcount = 1;
457     if (serial)
458         strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
459     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
460 
461     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
462 
463     switch(type) {
464     case IF_IDE:
465     case IF_SCSI:
466     case IF_XEN:
467     case IF_NONE:
468         switch(media) {
469 	case MEDIA_DISK:
470             if (cyls != 0) {
471                 bdrv_set_geometry_hint(dinfo->bdrv, cyls, heads, secs);
472                 bdrv_set_translation_hint(dinfo->bdrv, translation);
473             }
474 	    break;
475 	case MEDIA_CDROM:
476             dinfo->media_cd = 1;
477 	    break;
478 	}
479         break;
480     case IF_SD:
481     case IF_FLOPPY:
482     case IF_PFLASH:
483     case IF_MTD:
484         break;
485     case IF_VIRTIO:
486         /* add virtio block device */
487         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0);
488         qemu_opt_set(opts, "driver", "virtio-blk");
489         qemu_opt_set(opts, "drive", dinfo->id);
490         if (devaddr)
491             qemu_opt_set(opts, "addr", devaddr);
492         break;
493     default:
494         abort();
495     }
496     if (!file || !*file) {
497         return dinfo;
498     }
499     if (snapshot) {
500         /* always use cache=unsafe with snapshot */
501         bdrv_flags &= ~BDRV_O_CACHE_MASK;
502         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
503     }
504 
505     if (media == MEDIA_CDROM) {
506         /* CDROM is fine for any interface, don't check.  */
507         ro = 1;
508     } else if (ro == 1) {
509         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
510             error_report("readonly not supported by this bus type");
511             goto err;
512         }
513     }
514 
515     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
516 
517     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
518     if (ret < 0) {
519         error_report("could not open disk image %s: %s",
520                      file, strerror(-ret));
521         goto err;
522     }
523 
524     if (bdrv_key_required(dinfo->bdrv))
525         autostart = 0;
526     return dinfo;
527 
528 err:
529     bdrv_delete(dinfo->bdrv);
530     g_free(dinfo->id);
531     QTAILQ_REMOVE(&drives, dinfo, next);
532     g_free(dinfo);
533     return NULL;
534 }
535 
536 void do_commit(Monitor *mon, const QDict *qdict)
537 {
538     const char *device = qdict_get_str(qdict, "device");
539     BlockDriverState *bs;
540 
541     if (!strcmp(device, "all")) {
542         bdrv_commit_all();
543     } else {
544         bs = bdrv_find(device);
545         if (!bs) {
546             qerror_report(QERR_DEVICE_NOT_FOUND, device);
547             return;
548         }
549         bdrv_commit(bs);
550     }
551 }
552 
553 int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
554 {
555     const char *device = qdict_get_str(qdict, "device");
556     const char *filename = qdict_get_try_str(qdict, "snapshot-file");
557     const char *format = qdict_get_try_str(qdict, "format");
558     BlockDriverState *bs;
559     BlockDriver *drv, *old_drv, *proto_drv;
560     int ret = 0;
561     int flags;
562     char old_filename[1024];
563 
564     if (!filename) {
565         qerror_report(QERR_MISSING_PARAMETER, "snapshot-file");
566         ret = -1;
567         goto out;
568     }
569 
570     bs = bdrv_find(device);
571     if (!bs) {
572         qerror_report(QERR_DEVICE_NOT_FOUND, device);
573         ret = -1;
574         goto out;
575     }
576 
577     pstrcpy(old_filename, sizeof(old_filename), bs->filename);
578 
579     old_drv = bs->drv;
580     flags = bs->open_flags;
581 
582     if (!format) {
583         format = "qcow2";
584     }
585 
586     drv = bdrv_find_format(format);
587     if (!drv) {
588         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
589         ret = -1;
590         goto out;
591     }
592 
593     proto_drv = bdrv_find_protocol(filename);
594     if (!proto_drv) {
595         qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
596         ret = -1;
597         goto out;
598     }
599 
600     ret = bdrv_img_create(filename, format, bs->filename,
601                           bs->drv->format_name, NULL, -1, flags);
602     if (ret) {
603         goto out;
604     }
605 
606     qemu_aio_flush();
607     bdrv_flush(bs);
608 
609     bdrv_close(bs);
610     ret = bdrv_open(bs, filename, flags, drv);
611     /*
612      * If reopening the image file we just created fails, fall back
613      * and try to re-open the original image. If that fails too, we
614      * are in serious trouble.
615      */
616     if (ret != 0) {
617         ret = bdrv_open(bs, old_filename, flags, old_drv);
618         if (ret != 0) {
619             qerror_report(QERR_OPEN_FILE_FAILED, old_filename);
620         } else {
621             qerror_report(QERR_OPEN_FILE_FAILED, filename);
622         }
623     }
624 out:
625     if (ret) {
626         ret = -1;
627     }
628 
629     return ret;
630 }
631 
632 static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
633 {
634     if (!bdrv_dev_has_removable_media(bs)) {
635         qerror_report(QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
636         return -1;
637     }
638     if (bdrv_dev_is_medium_locked(bs) && !bdrv_dev_is_tray_open(bs)) {
639         bdrv_dev_eject_request(bs, force);
640         if (!force) {
641             qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
642             return -1;
643         }
644     }
645     bdrv_close(bs);
646     return 0;
647 }
648 
649 int do_eject(Monitor *mon, const QDict *qdict, QObject **ret_data)
650 {
651     BlockDriverState *bs;
652     int force = qdict_get_try_bool(qdict, "force", 0);
653     const char *filename = qdict_get_str(qdict, "device");
654 
655     bs = bdrv_find(filename);
656     if (!bs) {
657         qerror_report(QERR_DEVICE_NOT_FOUND, filename);
658         return -1;
659     }
660     return eject_device(mon, bs, force);
661 }
662 
663 int do_block_set_passwd(Monitor *mon, const QDict *qdict,
664                         QObject **ret_data)
665 {
666     BlockDriverState *bs;
667     int err;
668 
669     bs = bdrv_find(qdict_get_str(qdict, "device"));
670     if (!bs) {
671         qerror_report(QERR_DEVICE_NOT_FOUND, qdict_get_str(qdict, "device"));
672         return -1;
673     }
674 
675     err = bdrv_set_key(bs, qdict_get_str(qdict, "password"));
676     if (err == -EINVAL) {
677         qerror_report(QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
678         return -1;
679     } else if (err < 0) {
680         qerror_report(QERR_INVALID_PASSWORD);
681         return -1;
682     }
683 
684     return 0;
685 }
686 
687 int do_change_block(Monitor *mon, const char *device,
688                     const char *filename, const char *fmt)
689 {
690     BlockDriverState *bs;
691     BlockDriver *drv = NULL;
692     int bdrv_flags;
693 
694     bs = bdrv_find(device);
695     if (!bs) {
696         qerror_report(QERR_DEVICE_NOT_FOUND, device);
697         return -1;
698     }
699     if (fmt) {
700         drv = bdrv_find_whitelisted_format(fmt);
701         if (!drv) {
702             qerror_report(QERR_INVALID_BLOCK_FORMAT, fmt);
703             return -1;
704         }
705     }
706     if (eject_device(mon, bs, 0) < 0) {
707         return -1;
708     }
709     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
710     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
711     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
712         qerror_report(QERR_OPEN_FILE_FAILED, filename);
713         return -1;
714     }
715     return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
716 }
717 
718 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
719 {
720     const char *id = qdict_get_str(qdict, "id");
721     BlockDriverState *bs;
722 
723     bs = bdrv_find(id);
724     if (!bs) {
725         qerror_report(QERR_DEVICE_NOT_FOUND, id);
726         return -1;
727     }
728     if (bdrv_in_use(bs)) {
729         qerror_report(QERR_DEVICE_IN_USE, id);
730         return -1;
731     }
732 
733     /* quiesce block driver; prevent further io */
734     qemu_aio_flush();
735     bdrv_flush(bs);
736     bdrv_close(bs);
737 
738     /* if we have a device attached to this BlockDriverState
739      * then we need to make the drive anonymous until the device
740      * can be removed.  If this is a drive with no device backing
741      * then we can just get rid of the block driver state right here.
742      */
743     if (bdrv_get_attached_dev(bs)) {
744         bdrv_make_anon(bs);
745     } else {
746         drive_uninit(drive_get_by_blockdev(bs));
747     }
748 
749     return 0;
750 }
751 
752 /*
753  * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
754  * existing QERR_ macro mess is cleaned up.  A good example for better
755  * error reports can be found in the qemu-img resize code.
756  */
757 int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
758 {
759     const char *device = qdict_get_str(qdict, "device");
760     int64_t size = qdict_get_int(qdict, "size");
761     BlockDriverState *bs;
762 
763     bs = bdrv_find(device);
764     if (!bs) {
765         qerror_report(QERR_DEVICE_NOT_FOUND, device);
766         return -1;
767     }
768 
769     if (size < 0) {
770         qerror_report(QERR_UNDEFINED_ERROR);
771         return -1;
772     }
773 
774     if (bdrv_truncate(bs, size)) {
775         qerror_report(QERR_UNDEFINED_ERROR);
776         return -1;
777     }
778 
779     return 0;
780 }
781