xref: /openbmc/qemu/blockdev.c (revision 1f32989d)
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 "blockdev.h"
11 #include "hw/block-common.h"
12 #include "blockjob.h"
13 #include "monitor.h"
14 #include "qerror.h"
15 #include "qemu-option.h"
16 #include "qemu-config.h"
17 #include "qemu-objects.h"
18 #include "sysemu.h"
19 #include "block_int.h"
20 #include "qmp-commands.h"
21 #include "trace.h"
22 #include "arch_init.h"
23 
24 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
25 
26 static const char *const if_name[IF_COUNT] = {
27     [IF_NONE] = "none",
28     [IF_IDE] = "ide",
29     [IF_SCSI] = "scsi",
30     [IF_FLOPPY] = "floppy",
31     [IF_PFLASH] = "pflash",
32     [IF_MTD] = "mtd",
33     [IF_SD] = "sd",
34     [IF_VIRTIO] = "virtio",
35     [IF_XEN] = "xen",
36 };
37 
38 static const int if_max_devs[IF_COUNT] = {
39     /*
40      * Do not change these numbers!  They govern how drive option
41      * index maps to unit and bus.  That mapping is ABI.
42      *
43      * All controllers used to imlement if=T drives need to support
44      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
45      * Otherwise, some index values map to "impossible" bus, unit
46      * values.
47      *
48      * For instance, if you change [IF_SCSI] to 255, -drive
49      * if=scsi,index=12 no longer means bus=1,unit=5, but
50      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
51      * the drive can't be set up.  Regression.
52      */
53     [IF_IDE] = 2,
54     [IF_SCSI] = 7,
55 };
56 
57 /*
58  * We automatically delete the drive when a device using it gets
59  * unplugged.  Questionable feature, but we can't just drop it.
60  * Device models call blockdev_mark_auto_del() to schedule the
61  * automatic deletion, and generic qdev code calls blockdev_auto_del()
62  * when deletion is actually safe.
63  */
64 void blockdev_mark_auto_del(BlockDriverState *bs)
65 {
66     DriveInfo *dinfo = drive_get_by_blockdev(bs);
67 
68     if (bs->job) {
69         block_job_cancel(bs->job);
70     }
71     if (dinfo) {
72         dinfo->auto_del = 1;
73     }
74 }
75 
76 void blockdev_auto_del(BlockDriverState *bs)
77 {
78     DriveInfo *dinfo = drive_get_by_blockdev(bs);
79 
80     if (dinfo && dinfo->auto_del) {
81         drive_put_ref(dinfo);
82     }
83 }
84 
85 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
86 {
87     int max_devs = if_max_devs[type];
88     return max_devs ? index / max_devs : 0;
89 }
90 
91 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
92 {
93     int max_devs = if_max_devs[type];
94     return max_devs ? index % max_devs : index;
95 }
96 
97 QemuOpts *drive_def(const char *optstr)
98 {
99     return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
100 }
101 
102 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
103                     const char *optstr)
104 {
105     QemuOpts *opts;
106     char buf[32];
107 
108     opts = drive_def(optstr);
109     if (!opts) {
110         return NULL;
111     }
112     if (type != IF_DEFAULT) {
113         qemu_opt_set(opts, "if", if_name[type]);
114     }
115     if (index >= 0) {
116         snprintf(buf, sizeof(buf), "%d", index);
117         qemu_opt_set(opts, "index", buf);
118     }
119     if (file)
120         qemu_opt_set(opts, "file", file);
121     return opts;
122 }
123 
124 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
125 {
126     DriveInfo *dinfo;
127 
128     /* seek interface, bus and unit */
129 
130     QTAILQ_FOREACH(dinfo, &drives, next) {
131         if (dinfo->type == type &&
132 	    dinfo->bus == bus &&
133 	    dinfo->unit == unit)
134             return dinfo;
135     }
136 
137     return NULL;
138 }
139 
140 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
141 {
142     return drive_get(type,
143                      drive_index_to_bus_id(type, index),
144                      drive_index_to_unit_id(type, index));
145 }
146 
147 int drive_get_max_bus(BlockInterfaceType type)
148 {
149     int max_bus;
150     DriveInfo *dinfo;
151 
152     max_bus = -1;
153     QTAILQ_FOREACH(dinfo, &drives, next) {
154         if(dinfo->type == type &&
155            dinfo->bus > max_bus)
156             max_bus = dinfo->bus;
157     }
158     return max_bus;
159 }
160 
161 /* Get a block device.  This should only be used for single-drive devices
162    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
163    appropriate bus.  */
164 DriveInfo *drive_get_next(BlockInterfaceType type)
165 {
166     static int next_block_unit[IF_COUNT];
167 
168     return drive_get(type, 0, next_block_unit[type]++);
169 }
170 
171 DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
172 {
173     DriveInfo *dinfo;
174 
175     QTAILQ_FOREACH(dinfo, &drives, next) {
176         if (dinfo->bdrv == bs) {
177             return dinfo;
178         }
179     }
180     return NULL;
181 }
182 
183 static void bdrv_format_print(void *opaque, const char *name)
184 {
185     error_printf(" %s", name);
186 }
187 
188 static void drive_uninit(DriveInfo *dinfo)
189 {
190     qemu_opts_del(dinfo->opts);
191     bdrv_delete(dinfo->bdrv);
192     g_free(dinfo->id);
193     QTAILQ_REMOVE(&drives, dinfo, next);
194     g_free(dinfo);
195 }
196 
197 void drive_put_ref(DriveInfo *dinfo)
198 {
199     assert(dinfo->refcount);
200     if (--dinfo->refcount == 0) {
201         drive_uninit(dinfo);
202     }
203 }
204 
205 void drive_get_ref(DriveInfo *dinfo)
206 {
207     dinfo->refcount++;
208 }
209 
210 typedef struct {
211     QEMUBH *bh;
212     DriveInfo *dinfo;
213 } DrivePutRefBH;
214 
215 static void drive_put_ref_bh(void *opaque)
216 {
217     DrivePutRefBH *s = opaque;
218 
219     drive_put_ref(s->dinfo);
220     qemu_bh_delete(s->bh);
221     g_free(s);
222 }
223 
224 /*
225  * Release a drive reference in a BH
226  *
227  * It is not possible to use drive_put_ref() from a callback function when the
228  * callers still need the drive.  In such cases we schedule a BH to release the
229  * reference.
230  */
231 static void drive_put_ref_bh_schedule(DriveInfo *dinfo)
232 {
233     DrivePutRefBH *s;
234 
235     s = g_new(DrivePutRefBH, 1);
236     s->bh = qemu_bh_new(drive_put_ref_bh, s);
237     s->dinfo = dinfo;
238     qemu_bh_schedule(s->bh);
239 }
240 
241 static int parse_block_error_action(const char *buf, bool is_read)
242 {
243     if (!strcmp(buf, "ignore")) {
244         return BLOCKDEV_ON_ERROR_IGNORE;
245     } else if (!is_read && !strcmp(buf, "enospc")) {
246         return BLOCKDEV_ON_ERROR_ENOSPC;
247     } else if (!strcmp(buf, "stop")) {
248         return BLOCKDEV_ON_ERROR_STOP;
249     } else if (!strcmp(buf, "report")) {
250         return BLOCKDEV_ON_ERROR_REPORT;
251     } else {
252         error_report("'%s' invalid %s error action",
253                      buf, is_read ? "read" : "write");
254         return -1;
255     }
256 }
257 
258 static bool do_check_io_limits(BlockIOLimit *io_limits)
259 {
260     bool bps_flag;
261     bool iops_flag;
262 
263     assert(io_limits);
264 
265     bps_flag  = (io_limits->bps[BLOCK_IO_LIMIT_TOTAL] != 0)
266                  && ((io_limits->bps[BLOCK_IO_LIMIT_READ] != 0)
267                  || (io_limits->bps[BLOCK_IO_LIMIT_WRITE] != 0));
268     iops_flag = (io_limits->iops[BLOCK_IO_LIMIT_TOTAL] != 0)
269                  && ((io_limits->iops[BLOCK_IO_LIMIT_READ] != 0)
270                  || (io_limits->iops[BLOCK_IO_LIMIT_WRITE] != 0));
271     if (bps_flag || iops_flag) {
272         return false;
273     }
274 
275     return true;
276 }
277 
278 DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
279 {
280     const char *buf;
281     const char *file = NULL;
282     const char *serial;
283     const char *mediastr = "";
284     BlockInterfaceType type;
285     enum { MEDIA_DISK, MEDIA_CDROM } media;
286     int bus_id, unit_id;
287     int cyls, heads, secs, translation;
288     BlockDriver *drv = NULL;
289     int max_devs;
290     int index;
291     int ro = 0;
292     int bdrv_flags = 0;
293     int on_read_error, on_write_error;
294     const char *devaddr;
295     DriveInfo *dinfo;
296     BlockIOLimit io_limits;
297     int snapshot = 0;
298     bool copy_on_read;
299     int ret;
300 
301     translation = BIOS_ATA_TRANSLATION_AUTO;
302     media = MEDIA_DISK;
303 
304     /* extract parameters */
305     bus_id  = qemu_opt_get_number(opts, "bus", 0);
306     unit_id = qemu_opt_get_number(opts, "unit", -1);
307     index   = qemu_opt_get_number(opts, "index", -1);
308 
309     cyls  = qemu_opt_get_number(opts, "cyls", 0);
310     heads = qemu_opt_get_number(opts, "heads", 0);
311     secs  = qemu_opt_get_number(opts, "secs", 0);
312 
313     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
314     ro = qemu_opt_get_bool(opts, "readonly", 0);
315     copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false);
316 
317     file = qemu_opt_get(opts, "file");
318     serial = qemu_opt_get(opts, "serial");
319 
320     if ((buf = qemu_opt_get(opts, "if")) != NULL) {
321         for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
322             ;
323         if (type == IF_COUNT) {
324             error_report("unsupported bus type '%s'", buf);
325             return NULL;
326 	}
327     } else {
328         type = default_to_scsi ? IF_SCSI : IF_IDE;
329     }
330 
331     max_devs = if_max_devs[type];
332 
333     if (cyls || heads || secs) {
334         if (cyls < 1) {
335             error_report("invalid physical cyls number");
336 	    return NULL;
337 	}
338         if (heads < 1) {
339             error_report("invalid physical heads number");
340 	    return NULL;
341 	}
342         if (secs < 1) {
343             error_report("invalid physical secs number");
344 	    return NULL;
345 	}
346     }
347 
348     if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
349         if (!cyls) {
350             error_report("'%s' trans must be used with cyls, heads and secs",
351                          buf);
352             return NULL;
353         }
354         if (!strcmp(buf, "none"))
355             translation = BIOS_ATA_TRANSLATION_NONE;
356         else if (!strcmp(buf, "lba"))
357             translation = BIOS_ATA_TRANSLATION_LBA;
358         else if (!strcmp(buf, "auto"))
359             translation = BIOS_ATA_TRANSLATION_AUTO;
360 	else {
361             error_report("'%s' invalid translation type", buf);
362 	    return NULL;
363 	}
364     }
365 
366     if ((buf = qemu_opt_get(opts, "media")) != NULL) {
367         if (!strcmp(buf, "disk")) {
368 	    media = MEDIA_DISK;
369 	} else if (!strcmp(buf, "cdrom")) {
370             if (cyls || secs || heads) {
371                 error_report("CHS can't be set with media=%s", buf);
372 	        return NULL;
373             }
374 	    media = MEDIA_CDROM;
375 	} else {
376 	    error_report("'%s' invalid media", buf);
377 	    return NULL;
378 	}
379     }
380 
381     bdrv_flags |= BDRV_O_CACHE_WB;
382     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
383         if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
384             error_report("invalid cache option");
385             return NULL;
386         }
387     }
388 
389 #ifdef CONFIG_LINUX_AIO
390     if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
391         if (!strcmp(buf, "native")) {
392             bdrv_flags |= BDRV_O_NATIVE_AIO;
393         } else if (!strcmp(buf, "threads")) {
394             /* this is the default */
395         } else {
396            error_report("invalid aio option");
397            return NULL;
398         }
399     }
400 #endif
401 
402     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
403         if (is_help_option(buf)) {
404             error_printf("Supported formats:");
405             bdrv_iterate_format(bdrv_format_print, NULL);
406             error_printf("\n");
407             return NULL;
408         }
409         drv = bdrv_find_whitelisted_format(buf);
410         if (!drv) {
411             error_report("'%s' invalid format", buf);
412             return NULL;
413         }
414     }
415 
416     /* disk I/O throttling */
417     io_limits.bps[BLOCK_IO_LIMIT_TOTAL]  =
418                            qemu_opt_get_number(opts, "bps", 0);
419     io_limits.bps[BLOCK_IO_LIMIT_READ]   =
420                            qemu_opt_get_number(opts, "bps_rd", 0);
421     io_limits.bps[BLOCK_IO_LIMIT_WRITE]  =
422                            qemu_opt_get_number(opts, "bps_wr", 0);
423     io_limits.iops[BLOCK_IO_LIMIT_TOTAL] =
424                            qemu_opt_get_number(opts, "iops", 0);
425     io_limits.iops[BLOCK_IO_LIMIT_READ]  =
426                            qemu_opt_get_number(opts, "iops_rd", 0);
427     io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
428                            qemu_opt_get_number(opts, "iops_wr", 0);
429 
430     if (!do_check_io_limits(&io_limits)) {
431         error_report("bps(iops) and bps_rd/bps_wr(iops_rd/iops_wr) "
432                      "cannot be used at the same time");
433         return NULL;
434     }
435 
436     if (qemu_opt_get(opts, "boot") != NULL) {
437         fprintf(stderr, "qemu-kvm: boot=on|off is deprecated and will be "
438                 "ignored. Future versions will reject this parameter. Please "
439                 "update your scripts.\n");
440     }
441 
442     on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
443     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
444         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
445             error_report("werror is not supported by this bus type");
446             return NULL;
447         }
448 
449         on_write_error = parse_block_error_action(buf, 0);
450         if (on_write_error < 0) {
451             return NULL;
452         }
453     }
454 
455     on_read_error = BLOCKDEV_ON_ERROR_REPORT;
456     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
457         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
458             error_report("rerror is not supported by this bus type");
459             return NULL;
460         }
461 
462         on_read_error = parse_block_error_action(buf, 1);
463         if (on_read_error < 0) {
464             return NULL;
465         }
466     }
467 
468     if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
469         if (type != IF_VIRTIO) {
470             error_report("addr is not supported by this bus type");
471             return NULL;
472         }
473     }
474 
475     /* compute bus and unit according index */
476 
477     if (index != -1) {
478         if (bus_id != 0 || unit_id != -1) {
479             error_report("index cannot be used with bus and unit");
480             return NULL;
481         }
482         bus_id = drive_index_to_bus_id(type, index);
483         unit_id = drive_index_to_unit_id(type, index);
484     }
485 
486     /* if user doesn't specify a unit_id,
487      * try to find the first free
488      */
489 
490     if (unit_id == -1) {
491        unit_id = 0;
492        while (drive_get(type, bus_id, unit_id) != NULL) {
493            unit_id++;
494            if (max_devs && unit_id >= max_devs) {
495                unit_id -= max_devs;
496                bus_id++;
497            }
498        }
499     }
500 
501     /* check unit id */
502 
503     if (max_devs && unit_id >= max_devs) {
504         error_report("unit %d too big (max is %d)",
505                      unit_id, max_devs - 1);
506         return NULL;
507     }
508 
509     /*
510      * catch multiple definitions
511      */
512 
513     if (drive_get(type, bus_id, unit_id) != NULL) {
514         error_report("drive with bus=%d, unit=%d (index=%d) exists",
515                      bus_id, unit_id, index);
516         return NULL;
517     }
518 
519     /* init */
520 
521     dinfo = g_malloc0(sizeof(*dinfo));
522     if ((buf = qemu_opts_id(opts)) != NULL) {
523         dinfo->id = g_strdup(buf);
524     } else {
525         /* no id supplied -> create one */
526         dinfo->id = g_malloc0(32);
527         if (type == IF_IDE || type == IF_SCSI)
528             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
529         if (max_devs)
530             snprintf(dinfo->id, 32, "%s%i%s%i",
531                      if_name[type], bus_id, mediastr, unit_id);
532         else
533             snprintf(dinfo->id, 32, "%s%s%i",
534                      if_name[type], mediastr, unit_id);
535     }
536     dinfo->bdrv = bdrv_new(dinfo->id);
537     dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0;
538     dinfo->bdrv->read_only = ro;
539     dinfo->devaddr = devaddr;
540     dinfo->type = type;
541     dinfo->bus = bus_id;
542     dinfo->unit = unit_id;
543     dinfo->cyls = cyls;
544     dinfo->heads = heads;
545     dinfo->secs = secs;
546     dinfo->trans = translation;
547     dinfo->opts = opts;
548     dinfo->refcount = 1;
549     dinfo->serial = serial;
550     QTAILQ_INSERT_TAIL(&drives, dinfo, next);
551 
552     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
553 
554     /* disk I/O throttling */
555     bdrv_set_io_limits(dinfo->bdrv, &io_limits);
556 
557     switch(type) {
558     case IF_IDE:
559     case IF_SCSI:
560     case IF_XEN:
561     case IF_NONE:
562         dinfo->media_cd = media == MEDIA_CDROM;
563         break;
564     case IF_SD:
565     case IF_FLOPPY:
566     case IF_PFLASH:
567     case IF_MTD:
568         break;
569     case IF_VIRTIO:
570         /* add virtio block device */
571         opts = qemu_opts_create(qemu_find_opts("device"), NULL, 0, NULL);
572         if (arch_type == QEMU_ARCH_S390X) {
573             qemu_opt_set(opts, "driver", "virtio-blk-s390");
574         } else {
575             qemu_opt_set(opts, "driver", "virtio-blk-pci");
576         }
577         qemu_opt_set(opts, "drive", dinfo->id);
578         if (devaddr)
579             qemu_opt_set(opts, "addr", devaddr);
580         break;
581     default:
582         abort();
583     }
584     if (!file || !*file) {
585         return dinfo;
586     }
587     if (snapshot) {
588         /* always use cache=unsafe with snapshot */
589         bdrv_flags &= ~BDRV_O_CACHE_MASK;
590         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
591     }
592 
593     if (copy_on_read) {
594         bdrv_flags |= BDRV_O_COPY_ON_READ;
595     }
596 
597     if (runstate_check(RUN_STATE_INMIGRATE)) {
598         bdrv_flags |= BDRV_O_INCOMING;
599     }
600 
601     if (media == MEDIA_CDROM) {
602         /* CDROM is fine for any interface, don't check.  */
603         ro = 1;
604     } else if (ro == 1) {
605         if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY &&
606             type != IF_NONE && type != IF_PFLASH) {
607             error_report("readonly not supported by this bus type");
608             goto err;
609         }
610     }
611 
612     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
613 
614     if (ro && copy_on_read) {
615         error_report("warning: disabling copy_on_read on readonly drive");
616     }
617 
618     ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
619     if (ret < 0) {
620         error_report("could not open disk image %s: %s",
621                      file, strerror(-ret));
622         goto err;
623     }
624 
625     if (bdrv_key_required(dinfo->bdrv))
626         autostart = 0;
627     return dinfo;
628 
629 err:
630     bdrv_delete(dinfo->bdrv);
631     g_free(dinfo->id);
632     QTAILQ_REMOVE(&drives, dinfo, next);
633     g_free(dinfo);
634     return NULL;
635 }
636 
637 void do_commit(Monitor *mon, const QDict *qdict)
638 {
639     const char *device = qdict_get_str(qdict, "device");
640     BlockDriverState *bs;
641     int ret;
642 
643     if (!strcmp(device, "all")) {
644         ret = bdrv_commit_all();
645         if (ret == -EBUSY) {
646             qerror_report(QERR_DEVICE_IN_USE, device);
647             return;
648         }
649     } else {
650         bs = bdrv_find(device);
651         if (!bs) {
652             qerror_report(QERR_DEVICE_NOT_FOUND, device);
653             return;
654         }
655         ret = bdrv_commit(bs);
656         if (ret == -EBUSY) {
657             qerror_report(QERR_DEVICE_IN_USE, device);
658             return;
659         }
660     }
661 }
662 
663 static void blockdev_do_action(int kind, void *data, Error **errp)
664 {
665     BlockdevAction action;
666     BlockdevActionList list;
667 
668     action.kind = kind;
669     action.data = data;
670     list.value = &action;
671     list.next = NULL;
672     qmp_transaction(&list, errp);
673 }
674 
675 void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
676                                 bool has_format, const char *format,
677                                 bool has_mode, enum NewImageMode mode,
678                                 Error **errp)
679 {
680     BlockdevSnapshot snapshot = {
681         .device = (char *) device,
682         .snapshot_file = (char *) snapshot_file,
683         .has_format = has_format,
684         .format = (char *) format,
685         .has_mode = has_mode,
686         .mode = mode,
687     };
688     blockdev_do_action(BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC, &snapshot,
689                        errp);
690 }
691 
692 
693 /* New and old BlockDriverState structs for group snapshots */
694 typedef struct BlkTransactionStates {
695     BlockDriverState *old_bs;
696     BlockDriverState *new_bs;
697     QSIMPLEQ_ENTRY(BlkTransactionStates) entry;
698 } BlkTransactionStates;
699 
700 /*
701  * 'Atomic' group snapshots.  The snapshots are taken as a set, and if any fail
702  *  then we do not pivot any of the devices in the group, and abandon the
703  *  snapshots
704  */
705 void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
706 {
707     int ret = 0;
708     BlockdevActionList *dev_entry = dev_list;
709     BlkTransactionStates *states, *next;
710 
711     QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionStates) snap_bdrv_states;
712     QSIMPLEQ_INIT(&snap_bdrv_states);
713 
714     /* drain all i/o before any snapshots */
715     bdrv_drain_all();
716 
717     /* We don't do anything in this loop that commits us to the snapshot */
718     while (NULL != dev_entry) {
719         BlockdevAction *dev_info = NULL;
720         BlockDriver *proto_drv;
721         BlockDriver *drv;
722         int flags;
723         enum NewImageMode mode;
724         const char *new_image_file;
725         const char *device;
726         const char *format = "qcow2";
727 
728         dev_info = dev_entry->value;
729         dev_entry = dev_entry->next;
730 
731         states = g_malloc0(sizeof(BlkTransactionStates));
732         QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, states, entry);
733 
734         switch (dev_info->kind) {
735         case BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
736             device = dev_info->blockdev_snapshot_sync->device;
737             if (!dev_info->blockdev_snapshot_sync->has_mode) {
738                 dev_info->blockdev_snapshot_sync->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
739             }
740             new_image_file = dev_info->blockdev_snapshot_sync->snapshot_file;
741             if (dev_info->blockdev_snapshot_sync->has_format) {
742                 format = dev_info->blockdev_snapshot_sync->format;
743             }
744             mode = dev_info->blockdev_snapshot_sync->mode;
745             break;
746         default:
747             abort();
748         }
749 
750         drv = bdrv_find_format(format);
751         if (!drv) {
752             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
753             goto delete_and_fail;
754         }
755 
756         states->old_bs = bdrv_find(device);
757         if (!states->old_bs) {
758             error_set(errp, QERR_DEVICE_NOT_FOUND, device);
759             goto delete_and_fail;
760         }
761 
762         if (!bdrv_is_inserted(states->old_bs)) {
763             error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
764             goto delete_and_fail;
765         }
766 
767         if (bdrv_in_use(states->old_bs)) {
768             error_set(errp, QERR_DEVICE_IN_USE, device);
769             goto delete_and_fail;
770         }
771 
772         if (!bdrv_is_read_only(states->old_bs)) {
773             if (bdrv_flush(states->old_bs)) {
774                 error_set(errp, QERR_IO_ERROR);
775                 goto delete_and_fail;
776             }
777         }
778 
779         flags = states->old_bs->open_flags;
780 
781         proto_drv = bdrv_find_protocol(new_image_file);
782         if (!proto_drv) {
783             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
784             goto delete_and_fail;
785         }
786 
787         /* create new image w/backing file */
788         if (mode != NEW_IMAGE_MODE_EXISTING) {
789             ret = bdrv_img_create(new_image_file, format,
790                                   states->old_bs->filename,
791                                   states->old_bs->drv->format_name,
792                                   NULL, -1, flags);
793             if (ret) {
794                 error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
795                 goto delete_and_fail;
796             }
797         }
798 
799         /* We will manually add the backing_hd field to the bs later */
800         states->new_bs = bdrv_new("");
801         ret = bdrv_open(states->new_bs, new_image_file,
802                         flags | BDRV_O_NO_BACKING, drv);
803         if (ret != 0) {
804             error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
805             goto delete_and_fail;
806         }
807     }
808 
809 
810     /* Now we are going to do the actual pivot.  Everything up to this point
811      * is reversible, but we are committed at this point */
812     QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) {
813         /* This removes our old bs from the bdrv_states, and adds the new bs */
814         bdrv_append(states->new_bs, states->old_bs);
815         /* We don't need (or want) to use the transactional
816          * bdrv_reopen_multiple() across all the entries at once, because we
817          * don't want to abort all of them if one of them fails the reopen */
818         bdrv_reopen(states->new_bs, states->new_bs->open_flags & ~BDRV_O_RDWR,
819                     NULL);
820     }
821 
822     /* success */
823     goto exit;
824 
825 delete_and_fail:
826     /*
827     * failure, and it is all-or-none; abandon each new bs, and keep using
828     * the original bs for all images
829     */
830     QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) {
831         if (states->new_bs) {
832              bdrv_delete(states->new_bs);
833         }
834     }
835 exit:
836     QSIMPLEQ_FOREACH_SAFE(states, &snap_bdrv_states, entry, next) {
837         g_free(states);
838     }
839 }
840 
841 
842 static void eject_device(BlockDriverState *bs, int force, Error **errp)
843 {
844     if (bdrv_in_use(bs)) {
845         error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
846         return;
847     }
848     if (!bdrv_dev_has_removable_media(bs)) {
849         error_set(errp, QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
850         return;
851     }
852 
853     if (bdrv_dev_is_medium_locked(bs) && !bdrv_dev_is_tray_open(bs)) {
854         bdrv_dev_eject_request(bs, force);
855         if (!force) {
856             error_set(errp, QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
857             return;
858         }
859     }
860 
861     bdrv_close(bs);
862 }
863 
864 void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
865 {
866     BlockDriverState *bs;
867 
868     bs = bdrv_find(device);
869     if (!bs) {
870         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
871         return;
872     }
873 
874     eject_device(bs, force, errp);
875 }
876 
877 void qmp_block_passwd(const char *device, const char *password, Error **errp)
878 {
879     BlockDriverState *bs;
880     int err;
881 
882     bs = bdrv_find(device);
883     if (!bs) {
884         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
885         return;
886     }
887 
888     err = bdrv_set_key(bs, password);
889     if (err == -EINVAL) {
890         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
891         return;
892     } else if (err < 0) {
893         error_set(errp, QERR_INVALID_PASSWORD);
894         return;
895     }
896 }
897 
898 static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
899                                     int bdrv_flags, BlockDriver *drv,
900                                     const char *password, Error **errp)
901 {
902     if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
903         error_set(errp, QERR_OPEN_FILE_FAILED, filename);
904         return;
905     }
906 
907     if (bdrv_key_required(bs)) {
908         if (password) {
909             if (bdrv_set_key(bs, password) < 0) {
910                 error_set(errp, QERR_INVALID_PASSWORD);
911             }
912         } else {
913             error_set(errp, QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs),
914                       bdrv_get_encrypted_filename(bs));
915         }
916     } else if (password) {
917         error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
918     }
919 }
920 
921 void qmp_change_blockdev(const char *device, const char *filename,
922                          bool has_format, const char *format, Error **errp)
923 {
924     BlockDriverState *bs;
925     BlockDriver *drv = NULL;
926     int bdrv_flags;
927     Error *err = NULL;
928 
929     bs = bdrv_find(device);
930     if (!bs) {
931         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
932         return;
933     }
934 
935     if (format) {
936         drv = bdrv_find_whitelisted_format(format);
937         if (!drv) {
938             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
939             return;
940         }
941     }
942 
943     eject_device(bs, 0, &err);
944     if (error_is_set(&err)) {
945         error_propagate(errp, err);
946         return;
947     }
948 
949     bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
950     bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
951 
952     qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, errp);
953 }
954 
955 /* throttling disk I/O limits */
956 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
957                                int64_t bps_wr, int64_t iops, int64_t iops_rd,
958                                int64_t iops_wr, Error **errp)
959 {
960     BlockIOLimit io_limits;
961     BlockDriverState *bs;
962 
963     bs = bdrv_find(device);
964     if (!bs) {
965         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
966         return;
967     }
968 
969     io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
970     io_limits.bps[BLOCK_IO_LIMIT_READ]  = bps_rd;
971     io_limits.bps[BLOCK_IO_LIMIT_WRITE] = bps_wr;
972     io_limits.iops[BLOCK_IO_LIMIT_TOTAL]= iops;
973     io_limits.iops[BLOCK_IO_LIMIT_READ] = iops_rd;
974     io_limits.iops[BLOCK_IO_LIMIT_WRITE]= iops_wr;
975 
976     if (!do_check_io_limits(&io_limits)) {
977         error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
978         return;
979     }
980 
981     bs->io_limits = io_limits;
982     bs->slice_time = BLOCK_IO_SLICE_TIME;
983 
984     if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
985         bdrv_io_limits_enable(bs);
986     } else if (bs->io_limits_enabled && !bdrv_io_limits_enabled(bs)) {
987         bdrv_io_limits_disable(bs);
988     } else {
989         if (bs->block_timer) {
990             qemu_mod_timer(bs->block_timer, qemu_get_clock_ns(vm_clock));
991         }
992     }
993 }
994 
995 int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
996 {
997     const char *id = qdict_get_str(qdict, "id");
998     BlockDriverState *bs;
999 
1000     bs = bdrv_find(id);
1001     if (!bs) {
1002         qerror_report(QERR_DEVICE_NOT_FOUND, id);
1003         return -1;
1004     }
1005     if (bdrv_in_use(bs)) {
1006         qerror_report(QERR_DEVICE_IN_USE, id);
1007         return -1;
1008     }
1009 
1010     /* quiesce block driver; prevent further io */
1011     bdrv_drain_all();
1012     bdrv_flush(bs);
1013     bdrv_close(bs);
1014 
1015     /* if we have a device attached to this BlockDriverState
1016      * then we need to make the drive anonymous until the device
1017      * can be removed.  If this is a drive with no device backing
1018      * then we can just get rid of the block driver state right here.
1019      */
1020     if (bdrv_get_attached_dev(bs)) {
1021         bdrv_make_anon(bs);
1022     } else {
1023         drive_uninit(drive_get_by_blockdev(bs));
1024     }
1025 
1026     return 0;
1027 }
1028 
1029 void qmp_block_resize(const char *device, int64_t size, Error **errp)
1030 {
1031     BlockDriverState *bs;
1032 
1033     bs = bdrv_find(device);
1034     if (!bs) {
1035         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
1036         return;
1037     }
1038 
1039     if (size < 0) {
1040         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
1041         return;
1042     }
1043 
1044     switch (bdrv_truncate(bs, size)) {
1045     case 0:
1046         break;
1047     case -ENOMEDIUM:
1048         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1049         break;
1050     case -ENOTSUP:
1051         error_set(errp, QERR_UNSUPPORTED);
1052         break;
1053     case -EACCES:
1054         error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
1055         break;
1056     case -EBUSY:
1057         error_set(errp, QERR_DEVICE_IN_USE, device);
1058         break;
1059     default:
1060         error_set(errp, QERR_UNDEFINED_ERROR);
1061         break;
1062     }
1063 }
1064 
1065 static void block_job_cb(void *opaque, int ret)
1066 {
1067     BlockDriverState *bs = opaque;
1068     QObject *obj;
1069 
1070     trace_block_job_cb(bs, bs->job, ret);
1071 
1072     assert(bs->job);
1073     obj = qobject_from_block_job(bs->job);
1074     if (ret < 0) {
1075         QDict *dict = qobject_to_qdict(obj);
1076         qdict_put(dict, "error", qstring_from_str(strerror(-ret)));
1077     }
1078 
1079     if (block_job_is_cancelled(bs->job)) {
1080         monitor_protocol_event(QEVENT_BLOCK_JOB_CANCELLED, obj);
1081     } else {
1082         monitor_protocol_event(QEVENT_BLOCK_JOB_COMPLETED, obj);
1083     }
1084     qobject_decref(obj);
1085 
1086     drive_put_ref_bh_schedule(drive_get_by_blockdev(bs));
1087 }
1088 
1089 void qmp_block_stream(const char *device, bool has_base,
1090                       const char *base, bool has_speed, int64_t speed,
1091                       bool has_on_error, BlockdevOnError on_error,
1092                       Error **errp)
1093 {
1094     BlockDriverState *bs;
1095     BlockDriverState *base_bs = NULL;
1096     Error *local_err = NULL;
1097 
1098     if (!has_on_error) {
1099         on_error = BLOCKDEV_ON_ERROR_REPORT;
1100     }
1101 
1102     bs = bdrv_find(device);
1103     if (!bs) {
1104         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
1105         return;
1106     }
1107 
1108     if (base) {
1109         base_bs = bdrv_find_backing_image(bs, base);
1110         if (base_bs == NULL) {
1111             error_set(errp, QERR_BASE_NOT_FOUND, base);
1112             return;
1113         }
1114     }
1115 
1116     stream_start(bs, base_bs, base, has_speed ? speed : 0,
1117                  on_error, block_job_cb, bs, &local_err);
1118     if (error_is_set(&local_err)) {
1119         error_propagate(errp, local_err);
1120         return;
1121     }
1122 
1123     /* Grab a reference so hotplug does not delete the BlockDriverState from
1124      * underneath us.
1125      */
1126     drive_get_ref(drive_get_by_blockdev(bs));
1127 
1128     trace_qmp_block_stream(bs, bs->job);
1129 }
1130 
1131 void qmp_block_commit(const char *device,
1132                       bool has_base, const char *base, const char *top,
1133                       bool has_speed, int64_t speed,
1134                       Error **errp)
1135 {
1136     BlockDriverState *bs;
1137     BlockDriverState *base_bs, *top_bs;
1138     Error *local_err = NULL;
1139     /* This will be part of the QMP command, if/when the
1140      * BlockdevOnError change for blkmirror makes it in
1141      */
1142     BlockdevOnError on_error = BLOCKDEV_ON_ERROR_REPORT;
1143 
1144     /* drain all i/o before commits */
1145     bdrv_drain_all();
1146 
1147     bs = bdrv_find(device);
1148     if (!bs) {
1149         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
1150         return;
1151     }
1152 
1153     /* default top_bs is the active layer */
1154     top_bs = bs;
1155 
1156     if (top) {
1157         if (strcmp(bs->filename, top) != 0) {
1158             top_bs = bdrv_find_backing_image(bs, top);
1159         }
1160     }
1161 
1162     if (top_bs == NULL) {
1163         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
1164         return;
1165     }
1166 
1167     if (has_base && base) {
1168         base_bs = bdrv_find_backing_image(top_bs, base);
1169     } else {
1170         base_bs = bdrv_find_base(top_bs);
1171     }
1172 
1173     if (base_bs == NULL) {
1174         error_set(errp, QERR_BASE_NOT_FOUND, base ? base : "NULL");
1175         return;
1176     }
1177 
1178     commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,
1179                 &local_err);
1180     if (local_err != NULL) {
1181         error_propagate(errp, local_err);
1182         return;
1183     }
1184     /* Grab a reference so hotplug does not delete the BlockDriverState from
1185      * underneath us.
1186      */
1187     drive_get_ref(drive_get_by_blockdev(bs));
1188 }
1189 
1190 void qmp_drive_mirror(const char *device, const char *target,
1191                       bool has_format, const char *format,
1192                       enum MirrorSyncMode sync,
1193                       bool has_mode, enum NewImageMode mode,
1194                       bool has_speed, int64_t speed,
1195                       bool has_on_source_error, BlockdevOnError on_source_error,
1196                       bool has_on_target_error, BlockdevOnError on_target_error,
1197                       Error **errp)
1198 {
1199     BlockDriverInfo bdi;
1200     BlockDriverState *bs;
1201     BlockDriverState *source, *target_bs;
1202     BlockDriver *proto_drv;
1203     BlockDriver *drv = NULL;
1204     Error *local_err = NULL;
1205     int flags;
1206     uint64_t size;
1207     int ret;
1208 
1209     if (!has_speed) {
1210         speed = 0;
1211     }
1212     if (!has_on_source_error) {
1213         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
1214     }
1215     if (!has_on_target_error) {
1216         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
1217     }
1218     if (!has_mode) {
1219         mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1220     }
1221 
1222     bs = bdrv_find(device);
1223     if (!bs) {
1224         error_set(errp, QERR_DEVICE_NOT_FOUND, device);
1225         return;
1226     }
1227 
1228     if (!bdrv_is_inserted(bs)) {
1229         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1230         return;
1231     }
1232 
1233     if (!has_format) {
1234         format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : bs->drv->format_name;
1235     }
1236     if (format) {
1237         drv = bdrv_find_format(format);
1238         if (!drv) {
1239             error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
1240             return;
1241         }
1242     }
1243 
1244     if (bdrv_in_use(bs)) {
1245         error_set(errp, QERR_DEVICE_IN_USE, device);
1246         return;
1247     }
1248 
1249     flags = bs->open_flags | BDRV_O_RDWR;
1250     source = bs->backing_hd;
1251     if (!source && sync == MIRROR_SYNC_MODE_TOP) {
1252         sync = MIRROR_SYNC_MODE_FULL;
1253     }
1254 
1255     proto_drv = bdrv_find_protocol(target);
1256     if (!proto_drv) {
1257         error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
1258         return;
1259     }
1260 
1261     if (sync == MIRROR_SYNC_MODE_FULL && mode != NEW_IMAGE_MODE_EXISTING) {
1262         /* create new image w/o backing file */
1263         assert(format && drv);
1264         bdrv_get_geometry(bs, &size);
1265         size *= 512;
1266         ret = bdrv_img_create(target, format,
1267                               NULL, NULL, NULL, size, flags);
1268     } else {
1269         switch (mode) {
1270         case NEW_IMAGE_MODE_EXISTING:
1271             ret = 0;
1272             break;
1273         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
1274             /* create new image with backing file */
1275             ret = bdrv_img_create(target, format,
1276                                   source->filename,
1277                                   source->drv->format_name,
1278                                   NULL, -1, flags);
1279             break;
1280         default:
1281             abort();
1282         }
1283     }
1284 
1285     if (ret) {
1286         error_set(errp, QERR_OPEN_FILE_FAILED, target);
1287         return;
1288     }
1289 
1290     target_bs = bdrv_new("");
1291     ret = bdrv_open(target_bs, target, flags | BDRV_O_NO_BACKING, drv);
1292 
1293     if (ret < 0) {
1294         bdrv_delete(target_bs);
1295         error_set(errp, QERR_OPEN_FILE_FAILED, target);
1296         return;
1297     }
1298 
1299     /* We need a backing file if we will copy parts of a cluster.  */
1300     if (bdrv_get_info(target_bs, &bdi) >= 0 && bdi.cluster_size != 0 &&
1301         bdi.cluster_size >= BDRV_SECTORS_PER_DIRTY_CHUNK * 512) {
1302         ret = bdrv_open_backing_file(target_bs);
1303         if (ret < 0) {
1304             bdrv_delete(target_bs);
1305             error_set(errp, QERR_OPEN_FILE_FAILED, target);
1306             return;
1307         }
1308     }
1309 
1310     mirror_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
1311                  block_job_cb, bs, &local_err);
1312     if (local_err != NULL) {
1313         bdrv_delete(target_bs);
1314         error_propagate(errp, local_err);
1315         return;
1316     }
1317 
1318     /* Grab a reference so hotplug does not delete the BlockDriverState from
1319      * underneath us.
1320      */
1321     drive_get_ref(drive_get_by_blockdev(bs));
1322 }
1323 
1324 static BlockJob *find_block_job(const char *device)
1325 {
1326     BlockDriverState *bs;
1327 
1328     bs = bdrv_find(device);
1329     if (!bs || !bs->job) {
1330         return NULL;
1331     }
1332     return bs->job;
1333 }
1334 
1335 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
1336 {
1337     BlockJob *job = find_block_job(device);
1338 
1339     if (!job) {
1340         error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
1341         return;
1342     }
1343 
1344     block_job_set_speed(job, speed, errp);
1345 }
1346 
1347 void qmp_block_job_cancel(const char *device,
1348                           bool has_force, bool force, Error **errp)
1349 {
1350     BlockJob *job = find_block_job(device);
1351 
1352     if (!has_force) {
1353         force = false;
1354     }
1355 
1356     if (!job) {
1357         error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
1358         return;
1359     }
1360     if (job->paused && !force) {
1361         error_set(errp, QERR_BLOCK_JOB_PAUSED, device);
1362         return;
1363     }
1364 
1365     trace_qmp_block_job_cancel(job);
1366     block_job_cancel(job);
1367 }
1368 
1369 void qmp_block_job_pause(const char *device, Error **errp)
1370 {
1371     BlockJob *job = find_block_job(device);
1372 
1373     if (!job) {
1374         error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
1375         return;
1376     }
1377 
1378     trace_qmp_block_job_pause(job);
1379     block_job_pause(job);
1380 }
1381 
1382 void qmp_block_job_resume(const char *device, Error **errp)
1383 {
1384     BlockJob *job = find_block_job(device);
1385 
1386     if (!job) {
1387         error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
1388         return;
1389     }
1390 
1391     trace_qmp_block_job_resume(job);
1392     block_job_resume(job);
1393 }
1394 
1395 void qmp_block_job_complete(const char *device, Error **errp)
1396 {
1397     BlockJob *job = find_block_job(device);
1398 
1399     if (!job) {
1400         error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
1401         return;
1402     }
1403 
1404     trace_qmp_block_job_complete(job);
1405     block_job_complete(job, errp);
1406 }
1407 
1408 static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
1409 {
1410     BlockJobInfoList **prev = opaque;
1411     BlockJob *job = bs->job;
1412 
1413     if (job) {
1414         BlockJobInfoList *elem = g_new0(BlockJobInfoList, 1);
1415         elem->value = block_job_query(bs->job);
1416         (*prev)->next = elem;
1417         *prev = elem;
1418     }
1419 }
1420 
1421 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
1422 {
1423     /* Dummy is a fake list element for holding the head pointer */
1424     BlockJobInfoList dummy = {};
1425     BlockJobInfoList *prev = &dummy;
1426     bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
1427     return dummy.next;
1428 }
1429