xref: /openbmc/qemu/blockdev.c (revision 5f69e42d)
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  * This file incorporates work covered by the following copyright and
10  * permission notice:
11  *
12  * Copyright (c) 2003-2008 Fabrice Bellard
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a copy
15  * of this software and associated documentation files (the "Software"), to deal
16  * in the Software without restriction, including without limitation the rights
17  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
18  * copies of the Software, and to permit persons to whom the Software is
19  * furnished to do so, subject to the following conditions:
20  *
21  * The above copyright notice and this permission notice shall be included in
22  * all copies or substantial portions of the Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
27  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
29  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
30  * THE SOFTWARE.
31  */
32 
33 #include "qemu/osdep.h"
34 #include "sysemu/block-backend.h"
35 #include "sysemu/blockdev.h"
36 #include "hw/block/block.h"
37 #include "block/blockjob.h"
38 #include "block/dirty-bitmap.h"
39 #include "block/qdict.h"
40 #include "block/throttle-groups.h"
41 #include "monitor/monitor.h"
42 #include "qemu/error-report.h"
43 #include "qemu/option.h"
44 #include "qemu/qemu-print.h"
45 #include "qemu/config-file.h"
46 #include "qapi/qapi-commands-block.h"
47 #include "qapi/qapi-commands-transaction.h"
48 #include "qapi/qapi-visit-block-core.h"
49 #include "qapi/qmp/qdict.h"
50 #include "qapi/qmp/qnum.h"
51 #include "qapi/qmp/qstring.h"
52 #include "qapi/error.h"
53 #include "qapi/qmp/qerror.h"
54 #include "qapi/qmp/qlist.h"
55 #include "qapi/qobject-output-visitor.h"
56 #include "sysemu/sysemu.h"
57 #include "sysemu/iothread.h"
58 #include "block/block_int.h"
59 #include "block/trace.h"
60 #include "sysemu/runstate.h"
61 #include "sysemu/replay.h"
62 #include "qemu/cutils.h"
63 #include "qemu/help_option.h"
64 #include "qemu/main-loop.h"
65 #include "qemu/throttle-options.h"
66 
67 /* Protected by BQL */
68 QTAILQ_HEAD(, BlockDriverState) monitor_bdrv_states =
69     QTAILQ_HEAD_INITIALIZER(monitor_bdrv_states);
70 
71 void bdrv_set_monitor_owned(BlockDriverState *bs)
72 {
73     GLOBAL_STATE_CODE();
74     QTAILQ_INSERT_TAIL(&monitor_bdrv_states, bs, monitor_list);
75 }
76 
77 static const char *const if_name[IF_COUNT] = {
78     [IF_NONE] = "none",
79     [IF_IDE] = "ide",
80     [IF_SCSI] = "scsi",
81     [IF_FLOPPY] = "floppy",
82     [IF_PFLASH] = "pflash",
83     [IF_MTD] = "mtd",
84     [IF_SD] = "sd",
85     [IF_VIRTIO] = "virtio",
86     [IF_XEN] = "xen",
87 };
88 
89 static int if_max_devs[IF_COUNT] = {
90     /*
91      * Do not change these numbers!  They govern how drive option
92      * index maps to unit and bus.  That mapping is ABI.
93      *
94      * All controllers used to implement if=T drives need to support
95      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
96      * Otherwise, some index values map to "impossible" bus, unit
97      * values.
98      *
99      * For instance, if you change [IF_SCSI] to 255, -drive
100      * if=scsi,index=12 no longer means bus=1,unit=5, but
101      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
102      * the drive can't be set up.  Regression.
103      */
104     [IF_IDE] = 2,
105     [IF_SCSI] = 7,
106 };
107 
108 /**
109  * Boards may call this to offer board-by-board overrides
110  * of the default, global values.
111  */
112 void override_max_devs(BlockInterfaceType type, int max_devs)
113 {
114     BlockBackend *blk;
115     DriveInfo *dinfo;
116 
117     GLOBAL_STATE_CODE();
118 
119     if (max_devs <= 0) {
120         return;
121     }
122 
123     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
124         dinfo = blk_legacy_dinfo(blk);
125         if (dinfo->type == type) {
126             fprintf(stderr, "Cannot override units-per-bus property of"
127                     " the %s interface, because a drive of that type has"
128                     " already been added.\n", if_name[type]);
129             g_assert_not_reached();
130         }
131     }
132 
133     if_max_devs[type] = max_devs;
134 }
135 
136 /*
137  * We automatically delete the drive when a device using it gets
138  * unplugged.  Questionable feature, but we can't just drop it.
139  * Device models call blockdev_mark_auto_del() to schedule the
140  * automatic deletion, and generic qdev code calls blockdev_auto_del()
141  * when deletion is actually safe.
142  */
143 void blockdev_mark_auto_del(BlockBackend *blk)
144 {
145     DriveInfo *dinfo = blk_legacy_dinfo(blk);
146     BlockJob *job;
147 
148     GLOBAL_STATE_CODE();
149 
150     if (!dinfo) {
151         return;
152     }
153 
154     JOB_LOCK_GUARD();
155 
156     do {
157         job = block_job_next_locked(NULL);
158         while (job && (job->job.cancelled ||
159                        job->job.deferred_to_main_loop ||
160                        !block_job_has_bdrv(job, blk_bs(blk))))
161         {
162             job = block_job_next_locked(job);
163         }
164         if (job) {
165             /*
166              * This drops the job lock temporarily and polls, so we need to
167              * restart processing the list from the start after this.
168              */
169             job_cancel_locked(&job->job, false);
170         }
171     } while (job);
172 
173     dinfo->auto_del = 1;
174 }
175 
176 void blockdev_auto_del(BlockBackend *blk)
177 {
178     DriveInfo *dinfo = blk_legacy_dinfo(blk);
179     GLOBAL_STATE_CODE();
180 
181     if (dinfo && dinfo->auto_del) {
182         monitor_remove_blk(blk);
183         blk_unref(blk);
184     }
185 }
186 
187 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
188 {
189     int max_devs = if_max_devs[type];
190     return max_devs ? index / max_devs : 0;
191 }
192 
193 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
194 {
195     int max_devs = if_max_devs[type];
196     return max_devs ? index % max_devs : index;
197 }
198 
199 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
200                     const char *optstr)
201 {
202     QemuOpts *opts;
203 
204     GLOBAL_STATE_CODE();
205 
206     opts = qemu_opts_parse_noisily(qemu_find_opts("drive"), optstr, false);
207     if (!opts) {
208         return NULL;
209     }
210     if (type != IF_DEFAULT) {
211         qemu_opt_set(opts, "if", if_name[type], &error_abort);
212     }
213     if (index >= 0) {
214         qemu_opt_set_number(opts, "index", index, &error_abort);
215     }
216     if (file)
217         qemu_opt_set(opts, "file", file, &error_abort);
218     return opts;
219 }
220 
221 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
222 {
223     BlockBackend *blk;
224     DriveInfo *dinfo;
225 
226     GLOBAL_STATE_CODE();
227 
228     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
229         dinfo = blk_legacy_dinfo(blk);
230         if (dinfo && dinfo->type == type
231             && dinfo->bus == bus && dinfo->unit == unit) {
232             return dinfo;
233         }
234     }
235 
236     return NULL;
237 }
238 
239 /*
240  * Check board claimed all -drive that are meant to be claimed.
241  * Fatal error if any remain unclaimed.
242  */
243 void drive_check_orphaned(void)
244 {
245     BlockBackend *blk;
246     DriveInfo *dinfo;
247     Location loc;
248     bool orphans = false;
249 
250     GLOBAL_STATE_CODE();
251 
252     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
253         dinfo = blk_legacy_dinfo(blk);
254         /*
255          * Ignore default drives, because we create certain default
256          * drives unconditionally, then leave them unclaimed.  Not the
257          * users fault.
258          * Ignore IF_VIRTIO or IF_XEN, because it gets desugared into
259          * -device, so we can leave failing to -device.
260          * Ignore IF_NONE, because leaving unclaimed IF_NONE remains
261          * available for device_add is a feature.
262          */
263         if (dinfo->is_default || dinfo->type == IF_VIRTIO
264             || dinfo->type == IF_XEN || dinfo->type == IF_NONE) {
265             continue;
266         }
267         if (!blk_get_attached_dev(blk)) {
268             loc_push_none(&loc);
269             qemu_opts_loc_restore(dinfo->opts);
270             error_report("machine type does not support"
271                          " if=%s,bus=%d,unit=%d",
272                          if_name[dinfo->type], dinfo->bus, dinfo->unit);
273             loc_pop(&loc);
274             orphans = true;
275         }
276     }
277 
278     if (orphans) {
279         exit(1);
280     }
281 }
282 
283 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
284 {
285     GLOBAL_STATE_CODE();
286     return drive_get(type,
287                      drive_index_to_bus_id(type, index),
288                      drive_index_to_unit_id(type, index));
289 }
290 
291 int drive_get_max_bus(BlockInterfaceType type)
292 {
293     int max_bus;
294     BlockBackend *blk;
295     DriveInfo *dinfo;
296 
297     GLOBAL_STATE_CODE();
298 
299     max_bus = -1;
300     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
301         dinfo = blk_legacy_dinfo(blk);
302         if (dinfo && dinfo->type == type && dinfo->bus > max_bus) {
303             max_bus = dinfo->bus;
304         }
305     }
306     return max_bus;
307 }
308 
309 static void bdrv_format_print(void *opaque, const char *name)
310 {
311     qemu_printf(" %s", name);
312 }
313 
314 typedef struct {
315     QEMUBH *bh;
316     BlockDriverState *bs;
317 } BDRVPutRefBH;
318 
319 static int parse_block_error_action(const char *buf, bool is_read, Error **errp)
320 {
321     if (!strcmp(buf, "ignore")) {
322         return BLOCKDEV_ON_ERROR_IGNORE;
323     } else if (!is_read && !strcmp(buf, "enospc")) {
324         return BLOCKDEV_ON_ERROR_ENOSPC;
325     } else if (!strcmp(buf, "stop")) {
326         return BLOCKDEV_ON_ERROR_STOP;
327     } else if (!strcmp(buf, "report")) {
328         return BLOCKDEV_ON_ERROR_REPORT;
329     } else {
330         error_setg(errp, "'%s' invalid %s error action",
331                    buf, is_read ? "read" : "write");
332         return -1;
333     }
334 }
335 
336 static bool parse_stats_intervals(BlockAcctStats *stats, QList *intervals,
337                                   Error **errp)
338 {
339     const QListEntry *entry;
340     for (entry = qlist_first(intervals); entry; entry = qlist_next(entry)) {
341         switch (qobject_type(entry->value)) {
342 
343         case QTYPE_QSTRING: {
344             uint64_t length;
345             const char *str = qstring_get_str(qobject_to(QString,
346                                                          entry->value));
347             if (parse_uint_full(str, 10, &length) == 0 &&
348                 length > 0 && length <= UINT_MAX) {
349                 block_acct_add_interval(stats, (unsigned) length);
350             } else {
351                 error_setg(errp, "Invalid interval length: %s", str);
352                 return false;
353             }
354             break;
355         }
356 
357         case QTYPE_QNUM: {
358             int64_t length = qnum_get_int(qobject_to(QNum, entry->value));
359 
360             if (length > 0 && length <= UINT_MAX) {
361                 block_acct_add_interval(stats, (unsigned) length);
362             } else {
363                 error_setg(errp, "Invalid interval length: %" PRId64, length);
364                 return false;
365             }
366             break;
367         }
368 
369         default:
370             error_setg(errp, "The specification of stats-intervals is invalid");
371             return false;
372         }
373     }
374     return true;
375 }
376 
377 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
378 
379 /* All parameters but @opts are optional and may be set to NULL. */
380 static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
381     const char **throttling_group, ThrottleConfig *throttle_cfg,
382     BlockdevDetectZeroesOptions *detect_zeroes, Error **errp)
383 {
384     Error *local_error = NULL;
385     const char *aio;
386 
387     if (bdrv_flags) {
388         if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
389             *bdrv_flags |= BDRV_O_COPY_ON_READ;
390         }
391 
392         if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
393             if (bdrv_parse_aio(aio, bdrv_flags) < 0) {
394                 error_setg(errp, "invalid aio option");
395                 return;
396             }
397         }
398     }
399 
400     /* disk I/O throttling */
401     if (throttling_group) {
402         *throttling_group = qemu_opt_get(opts, "throttling.group");
403     }
404 
405     if (throttle_cfg) {
406         throttle_config_init(throttle_cfg);
407         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
408             qemu_opt_get_number(opts, "throttling.bps-total", 0);
409         throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
410             qemu_opt_get_number(opts, "throttling.bps-read", 0);
411         throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
412             qemu_opt_get_number(opts, "throttling.bps-write", 0);
413         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
414             qemu_opt_get_number(opts, "throttling.iops-total", 0);
415         throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
416             qemu_opt_get_number(opts, "throttling.iops-read", 0);
417         throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
418             qemu_opt_get_number(opts, "throttling.iops-write", 0);
419 
420         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
421             qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
422         throttle_cfg->buckets[THROTTLE_BPS_READ].max  =
423             qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
424         throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
425             qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
426         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
427             qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
428         throttle_cfg->buckets[THROTTLE_OPS_READ].max =
429             qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
430         throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
431             qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
432 
433         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].burst_length =
434             qemu_opt_get_number(opts, "throttling.bps-total-max-length", 1);
435         throttle_cfg->buckets[THROTTLE_BPS_READ].burst_length  =
436             qemu_opt_get_number(opts, "throttling.bps-read-max-length", 1);
437         throttle_cfg->buckets[THROTTLE_BPS_WRITE].burst_length =
438             qemu_opt_get_number(opts, "throttling.bps-write-max-length", 1);
439         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].burst_length =
440             qemu_opt_get_number(opts, "throttling.iops-total-max-length", 1);
441         throttle_cfg->buckets[THROTTLE_OPS_READ].burst_length =
442             qemu_opt_get_number(opts, "throttling.iops-read-max-length", 1);
443         throttle_cfg->buckets[THROTTLE_OPS_WRITE].burst_length =
444             qemu_opt_get_number(opts, "throttling.iops-write-max-length", 1);
445 
446         throttle_cfg->op_size =
447             qemu_opt_get_number(opts, "throttling.iops-size", 0);
448 
449         if (!throttle_is_valid(throttle_cfg, errp)) {
450             return;
451         }
452     }
453 
454     if (detect_zeroes) {
455         *detect_zeroes =
456             qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
457                             qemu_opt_get(opts, "detect-zeroes"),
458                             BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
459                             &local_error);
460         if (local_error) {
461             error_propagate(errp, local_error);
462             return;
463         }
464     }
465 }
466 
467 static OnOffAuto account_get_opt(QemuOpts *opts, const char *name)
468 {
469     if (!qemu_opt_find(opts, name)) {
470         return ON_OFF_AUTO_AUTO;
471     }
472     if (qemu_opt_get_bool(opts, name, true)) {
473         return ON_OFF_AUTO_ON;
474     }
475     return ON_OFF_AUTO_OFF;
476 }
477 
478 /* Takes the ownership of bs_opts */
479 static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
480                                    Error **errp)
481 {
482     const char *buf;
483     int bdrv_flags = 0;
484     int on_read_error, on_write_error;
485     OnOffAuto account_invalid, account_failed;
486     bool writethrough, read_only;
487     BlockBackend *blk;
488     BlockDriverState *bs;
489     ThrottleConfig cfg;
490     int snapshot = 0;
491     Error *error = NULL;
492     QemuOpts *opts;
493     QDict *interval_dict = NULL;
494     QList *interval_list = NULL;
495     const char *id;
496     BlockdevDetectZeroesOptions detect_zeroes =
497         BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
498     const char *throttling_group = NULL;
499 
500     /* Check common options by copying from bs_opts to opts, all other options
501      * stay in bs_opts for processing by bdrv_open(). */
502     id = qdict_get_try_str(bs_opts, "id");
503     opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, errp);
504     if (!opts) {
505         goto err_no_opts;
506     }
507 
508     if (!qemu_opts_absorb_qdict(opts, bs_opts, errp)) {
509         goto early_err;
510     }
511 
512     if (id) {
513         qdict_del(bs_opts, "id");
514     }
515 
516     /* extract parameters */
517     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
518 
519     account_invalid = account_get_opt(opts, "stats-account-invalid");
520     account_failed = account_get_opt(opts, "stats-account-failed");
521 
522     writethrough = !qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true);
523 
524     id = qemu_opts_id(opts);
525 
526     qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals.");
527     qdict_array_split(interval_dict, &interval_list);
528 
529     if (qdict_size(interval_dict) != 0) {
530         error_setg(errp, "Invalid option stats-intervals.%s",
531                    qdict_first(interval_dict)->key);
532         goto early_err;
533     }
534 
535     extract_common_blockdev_options(opts, &bdrv_flags, &throttling_group, &cfg,
536                                     &detect_zeroes, &error);
537     if (error) {
538         error_propagate(errp, error);
539         goto early_err;
540     }
541 
542     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
543         if (is_help_option(buf)) {
544             qemu_printf("Supported formats:");
545             bdrv_iterate_format(bdrv_format_print, NULL, false);
546             qemu_printf("\nSupported formats (read-only):");
547             bdrv_iterate_format(bdrv_format_print, NULL, true);
548             qemu_printf("\n");
549             goto early_err;
550         }
551 
552         if (qdict_haskey(bs_opts, "driver")) {
553             error_setg(errp, "Cannot specify both 'driver' and 'format'");
554             goto early_err;
555         }
556         qdict_put_str(bs_opts, "driver", buf);
557     }
558 
559     on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
560     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
561         on_write_error = parse_block_error_action(buf, 0, &error);
562         if (error) {
563             error_propagate(errp, error);
564             goto early_err;
565         }
566     }
567 
568     on_read_error = BLOCKDEV_ON_ERROR_REPORT;
569     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
570         on_read_error = parse_block_error_action(buf, 1, &error);
571         if (error) {
572             error_propagate(errp, error);
573             goto early_err;
574         }
575     }
576 
577     if (snapshot) {
578         bdrv_flags |= BDRV_O_SNAPSHOT;
579     }
580 
581     read_only = qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false);
582 
583     /* init */
584     if ((!file || !*file) && !qdict_size(bs_opts)) {
585         BlockBackendRootState *blk_rs;
586 
587         blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
588         blk_rs = blk_get_root_state(blk);
589         blk_rs->open_flags    = bdrv_flags | (read_only ? 0 : BDRV_O_RDWR);
590         blk_rs->detect_zeroes = detect_zeroes;
591 
592         qobject_unref(bs_opts);
593     } else {
594         if (file && !*file) {
595             file = NULL;
596         }
597 
598         /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
599          * with other callers) rather than what we want as the real defaults.
600          * Apply the defaults here instead. */
601         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
602         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
603         qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY,
604                               read_only ? "on" : "off");
605         qdict_set_default_str(bs_opts, BDRV_OPT_AUTO_READ_ONLY, "on");
606         assert((bdrv_flags & BDRV_O_CACHE_MASK) == 0);
607 
608         if (runstate_check(RUN_STATE_INMIGRATE)) {
609             bdrv_flags |= BDRV_O_INACTIVE;
610         }
611 
612         blk = blk_new_open(file, NULL, bs_opts, bdrv_flags, errp);
613         if (!blk) {
614             goto err_no_bs_opts;
615         }
616         bs = blk_bs(blk);
617 
618         bs->detect_zeroes = detect_zeroes;
619 
620         block_acct_setup(blk_get_stats(blk), account_invalid, account_failed);
621 
622         if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
623             blk_unref(blk);
624             blk = NULL;
625             goto err_no_bs_opts;
626         }
627     }
628 
629     /* disk I/O throttling */
630     if (throttle_enabled(&cfg)) {
631         if (!throttling_group) {
632             throttling_group = id;
633         }
634         blk_io_limits_enable(blk, throttling_group);
635         blk_set_io_limits(blk, &cfg);
636     }
637 
638     blk_set_enable_write_cache(blk, !writethrough);
639     blk_set_on_error(blk, on_read_error, on_write_error);
640 
641     if (!monitor_add_blk(blk, id, errp)) {
642         blk_unref(blk);
643         blk = NULL;
644         goto err_no_bs_opts;
645     }
646 
647 err_no_bs_opts:
648     qemu_opts_del(opts);
649     qobject_unref(interval_dict);
650     qobject_unref(interval_list);
651     return blk;
652 
653 early_err:
654     qemu_opts_del(opts);
655     qobject_unref(interval_dict);
656     qobject_unref(interval_list);
657 err_no_opts:
658     qobject_unref(bs_opts);
659     return NULL;
660 }
661 
662 /* Takes the ownership of bs_opts */
663 BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
664 {
665     int bdrv_flags = 0;
666 
667     GLOBAL_STATE_CODE();
668     /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
669      * with other callers) rather than what we want as the real defaults.
670      * Apply the defaults here instead. */
671     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
672     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
673     qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY, "off");
674 
675     if (runstate_check(RUN_STATE_INMIGRATE)) {
676         bdrv_flags |= BDRV_O_INACTIVE;
677     }
678 
679     return bdrv_open(NULL, NULL, bs_opts, bdrv_flags, errp);
680 }
681 
682 void blockdev_close_all_bdrv_states(void)
683 {
684     BlockDriverState *bs, *next_bs;
685 
686     GLOBAL_STATE_CODE();
687     QTAILQ_FOREACH_SAFE(bs, &monitor_bdrv_states, monitor_list, next_bs) {
688         bdrv_unref(bs);
689     }
690 }
691 
692 /* Iterates over the list of monitor-owned BlockDriverStates */
693 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs)
694 {
695     GLOBAL_STATE_CODE();
696     return bs ? QTAILQ_NEXT(bs, monitor_list)
697               : QTAILQ_FIRST(&monitor_bdrv_states);
698 }
699 
700 static bool qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
701                             Error **errp)
702 {
703     const char *value;
704 
705     value = qemu_opt_get(opts, from);
706     if (value) {
707         if (qemu_opt_find(opts, to)) {
708             error_setg(errp, "'%s' and its alias '%s' can't be used at the "
709                        "same time", to, from);
710             return false;
711         }
712     }
713 
714     /* rename all items in opts */
715     while ((value = qemu_opt_get(opts, from))) {
716         qemu_opt_set(opts, to, value, &error_abort);
717         qemu_opt_unset(opts, from);
718     }
719     return true;
720 }
721 
722 QemuOptsList qemu_legacy_drive_opts = {
723     .name = "drive",
724     .head = QTAILQ_HEAD_INITIALIZER(qemu_legacy_drive_opts.head),
725     .desc = {
726         {
727             .name = "bus",
728             .type = QEMU_OPT_NUMBER,
729             .help = "bus number",
730         },{
731             .name = "unit",
732             .type = QEMU_OPT_NUMBER,
733             .help = "unit number (i.e. lun for scsi)",
734         },{
735             .name = "index",
736             .type = QEMU_OPT_NUMBER,
737             .help = "index number",
738         },{
739             .name = "media",
740             .type = QEMU_OPT_STRING,
741             .help = "media type (disk, cdrom)",
742         },{
743             .name = "if",
744             .type = QEMU_OPT_STRING,
745             .help = "interface (ide, scsi, sd, mtd, floppy, pflash, virtio)",
746         },{
747             .name = "file",
748             .type = QEMU_OPT_STRING,
749             .help = "file name",
750         },
751 
752         /* Options that are passed on, but have special semantics with -drive */
753         {
754             .name = BDRV_OPT_READ_ONLY,
755             .type = QEMU_OPT_BOOL,
756             .help = "open drive file as read-only",
757         },{
758             .name = "rerror",
759             .type = QEMU_OPT_STRING,
760             .help = "read error action",
761         },{
762             .name = "werror",
763             .type = QEMU_OPT_STRING,
764             .help = "write error action",
765         },{
766             .name = "copy-on-read",
767             .type = QEMU_OPT_BOOL,
768             .help = "copy read data from backing file into image file",
769         },
770 
771         { /* end of list */ }
772     },
773 };
774 
775 DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type,
776                      Error **errp)
777 {
778     const char *value;
779     BlockBackend *blk;
780     DriveInfo *dinfo = NULL;
781     QDict *bs_opts;
782     QemuOpts *legacy_opts;
783     DriveMediaType media = MEDIA_DISK;
784     BlockInterfaceType type;
785     int max_devs, bus_id, unit_id, index;
786     const char *werror, *rerror;
787     bool read_only = false;
788     bool copy_on_read;
789     const char *filename;
790     int i;
791 
792     GLOBAL_STATE_CODE();
793 
794     /* Change legacy command line options into QMP ones */
795     static const struct {
796         const char *from;
797         const char *to;
798     } opt_renames[] = {
799         { "iops",           "throttling.iops-total" },
800         { "iops_rd",        "throttling.iops-read" },
801         { "iops_wr",        "throttling.iops-write" },
802 
803         { "bps",            "throttling.bps-total" },
804         { "bps_rd",         "throttling.bps-read" },
805         { "bps_wr",         "throttling.bps-write" },
806 
807         { "iops_max",       "throttling.iops-total-max" },
808         { "iops_rd_max",    "throttling.iops-read-max" },
809         { "iops_wr_max",    "throttling.iops-write-max" },
810 
811         { "bps_max",        "throttling.bps-total-max" },
812         { "bps_rd_max",     "throttling.bps-read-max" },
813         { "bps_wr_max",     "throttling.bps-write-max" },
814 
815         { "iops_size",      "throttling.iops-size" },
816 
817         { "group",          "throttling.group" },
818 
819         { "readonly",       BDRV_OPT_READ_ONLY },
820     };
821 
822     for (i = 0; i < ARRAY_SIZE(opt_renames); i++) {
823         if (!qemu_opt_rename(all_opts, opt_renames[i].from,
824                              opt_renames[i].to, errp)) {
825             return NULL;
826         }
827     }
828 
829     value = qemu_opt_get(all_opts, "cache");
830     if (value) {
831         int flags = 0;
832         bool writethrough;
833 
834         if (bdrv_parse_cache_mode(value, &flags, &writethrough) != 0) {
835             error_setg(errp, "invalid cache option");
836             return NULL;
837         }
838 
839         /* Specific options take precedence */
840         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_WB)) {
841             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_WB,
842                               !writethrough, &error_abort);
843         }
844         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_DIRECT)) {
845             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_DIRECT,
846                               !!(flags & BDRV_O_NOCACHE), &error_abort);
847         }
848         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_NO_FLUSH)) {
849             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_NO_FLUSH,
850                               !!(flags & BDRV_O_NO_FLUSH), &error_abort);
851         }
852         qemu_opt_unset(all_opts, "cache");
853     }
854 
855     /* Get a QDict for processing the options */
856     bs_opts = qdict_new();
857     qemu_opts_to_qdict(all_opts, bs_opts);
858 
859     legacy_opts = qemu_opts_create(&qemu_legacy_drive_opts, NULL, 0,
860                                    &error_abort);
861     if (!qemu_opts_absorb_qdict(legacy_opts, bs_opts, errp)) {
862         goto fail;
863     }
864 
865     /* Media type */
866     value = qemu_opt_get(legacy_opts, "media");
867     if (value) {
868         if (!strcmp(value, "disk")) {
869             media = MEDIA_DISK;
870         } else if (!strcmp(value, "cdrom")) {
871             media = MEDIA_CDROM;
872             read_only = true;
873         } else {
874             error_setg(errp, "'%s' invalid media", value);
875             goto fail;
876         }
877     }
878 
879     /* copy-on-read is disabled with a warning for read-only devices */
880     read_only |= qemu_opt_get_bool(legacy_opts, BDRV_OPT_READ_ONLY, false);
881     copy_on_read = qemu_opt_get_bool(legacy_opts, "copy-on-read", false);
882 
883     if (read_only && copy_on_read) {
884         warn_report("disabling copy-on-read on read-only drive");
885         copy_on_read = false;
886     }
887 
888     qdict_put_str(bs_opts, BDRV_OPT_READ_ONLY, read_only ? "on" : "off");
889     qdict_put_str(bs_opts, "copy-on-read", copy_on_read ? "on" : "off");
890 
891     /* Controller type */
892     value = qemu_opt_get(legacy_opts, "if");
893     if (value) {
894         for (type = 0;
895              type < IF_COUNT && strcmp(value, if_name[type]);
896              type++) {
897         }
898         if (type == IF_COUNT) {
899             error_setg(errp, "unsupported bus type '%s'", value);
900             goto fail;
901         }
902     } else {
903         type = block_default_type;
904     }
905 
906     /* Device address specified by bus/unit or index.
907      * If none was specified, try to find the first free one. */
908     bus_id  = qemu_opt_get_number(legacy_opts, "bus", 0);
909     unit_id = qemu_opt_get_number(legacy_opts, "unit", -1);
910     index   = qemu_opt_get_number(legacy_opts, "index", -1);
911 
912     max_devs = if_max_devs[type];
913 
914     if (index != -1) {
915         if (bus_id != 0 || unit_id != -1) {
916             error_setg(errp, "index cannot be used with bus and unit");
917             goto fail;
918         }
919         bus_id = drive_index_to_bus_id(type, index);
920         unit_id = drive_index_to_unit_id(type, index);
921     }
922 
923     if (unit_id == -1) {
924        unit_id = 0;
925        while (drive_get(type, bus_id, unit_id) != NULL) {
926            unit_id++;
927            if (max_devs && unit_id >= max_devs) {
928                unit_id -= max_devs;
929                bus_id++;
930            }
931        }
932     }
933 
934     if (max_devs && unit_id >= max_devs) {
935         error_setg(errp, "unit %d too big (max is %d)", unit_id, max_devs - 1);
936         goto fail;
937     }
938 
939     if (drive_get(type, bus_id, unit_id) != NULL) {
940         error_setg(errp, "drive with bus=%d, unit=%d (index=%d) exists",
941                    bus_id, unit_id, index);
942         goto fail;
943     }
944 
945     /* no id supplied -> create one */
946     if (qemu_opts_id(all_opts) == NULL) {
947         char *new_id;
948         const char *mediastr = "";
949         if (type == IF_IDE || type == IF_SCSI) {
950             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
951         }
952         if (max_devs) {
953             new_id = g_strdup_printf("%s%i%s%i", if_name[type], bus_id,
954                                      mediastr, unit_id);
955         } else {
956             new_id = g_strdup_printf("%s%s%i", if_name[type],
957                                      mediastr, unit_id);
958         }
959         qdict_put_str(bs_opts, "id", new_id);
960         g_free(new_id);
961     }
962 
963     /* Add virtio block device */
964     if (type == IF_VIRTIO) {
965         QemuOpts *devopts;
966         devopts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
967                                    &error_abort);
968         qemu_opt_set(devopts, "driver", "virtio-blk", &error_abort);
969         qemu_opt_set(devopts, "drive", qdict_get_str(bs_opts, "id"),
970                      &error_abort);
971     } else if (type == IF_XEN) {
972         QemuOpts *devopts;
973         devopts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
974                                    &error_abort);
975         qemu_opt_set(devopts, "driver",
976                      (media == MEDIA_CDROM) ? "xen-cdrom" : "xen-disk",
977                      &error_abort);
978         qemu_opt_set(devopts, "drive", qdict_get_str(bs_opts, "id"),
979                      &error_abort);
980     }
981 
982     filename = qemu_opt_get(legacy_opts, "file");
983 
984     /* Check werror/rerror compatibility with if=... */
985     werror = qemu_opt_get(legacy_opts, "werror");
986     if (werror != NULL) {
987         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO &&
988             type != IF_NONE) {
989             error_setg(errp, "werror is not supported by this bus type");
990             goto fail;
991         }
992         qdict_put_str(bs_opts, "werror", werror);
993     }
994 
995     rerror = qemu_opt_get(legacy_opts, "rerror");
996     if (rerror != NULL) {
997         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI &&
998             type != IF_NONE) {
999             error_setg(errp, "rerror is not supported by this bus type");
1000             goto fail;
1001         }
1002         qdict_put_str(bs_opts, "rerror", rerror);
1003     }
1004 
1005     /* Actual block device init: Functionality shared with blockdev-add */
1006     blk = blockdev_init(filename, bs_opts, errp);
1007     bs_opts = NULL;
1008     if (!blk) {
1009         goto fail;
1010     }
1011 
1012     /* Create legacy DriveInfo */
1013     dinfo = g_malloc0(sizeof(*dinfo));
1014     dinfo->opts = all_opts;
1015 
1016     dinfo->type = type;
1017     dinfo->bus = bus_id;
1018     dinfo->unit = unit_id;
1019 
1020     blk_set_legacy_dinfo(blk, dinfo);
1021 
1022     switch(type) {
1023     case IF_IDE:
1024     case IF_SCSI:
1025     case IF_XEN:
1026     case IF_NONE:
1027         dinfo->media_cd = media == MEDIA_CDROM;
1028         break;
1029     default:
1030         break;
1031     }
1032 
1033 fail:
1034     qemu_opts_del(legacy_opts);
1035     qobject_unref(bs_opts);
1036     return dinfo;
1037 }
1038 
1039 static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
1040 {
1041     BlockDriverState *bs;
1042 
1043     GRAPH_RDLOCK_GUARD_MAINLOOP();
1044 
1045     bs = bdrv_lookup_bs(name, name, errp);
1046     if (bs == NULL) {
1047         return NULL;
1048     }
1049 
1050     if (!bdrv_is_root_node(bs)) {
1051         error_setg(errp, "Need a root block node");
1052         return NULL;
1053     }
1054 
1055     if (!bdrv_is_inserted(bs)) {
1056         error_setg(errp, "Device has no medium");
1057         bs = NULL;
1058     }
1059 
1060     return bs;
1061 }
1062 
1063 static void blockdev_do_action(TransactionAction *action, Error **errp)
1064 {
1065     TransactionActionList list;
1066 
1067     list.value = action;
1068     list.next = NULL;
1069     qmp_transaction(&list, NULL, errp);
1070 }
1071 
1072 void qmp_blockdev_snapshot_sync(const char *device, const char *node_name,
1073                                 const char *snapshot_file,
1074                                 const char *snapshot_node_name,
1075                                 const char *format,
1076                                 bool has_mode, NewImageMode mode, Error **errp)
1077 {
1078     BlockdevSnapshotSync snapshot = {
1079         .device = (char *) device,
1080         .node_name = (char *) node_name,
1081         .snapshot_file = (char *) snapshot_file,
1082         .snapshot_node_name = (char *) snapshot_node_name,
1083         .format = (char *) format,
1084         .has_mode = has_mode,
1085         .mode = mode,
1086     };
1087     TransactionAction action = {
1088         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
1089         .u.blockdev_snapshot_sync.data = &snapshot,
1090     };
1091     blockdev_do_action(&action, errp);
1092 }
1093 
1094 void qmp_blockdev_snapshot(const char *node, const char *overlay,
1095                            Error **errp)
1096 {
1097     BlockdevSnapshot snapshot_data = {
1098         .node = (char *) node,
1099         .overlay = (char *) overlay
1100     };
1101     TransactionAction action = {
1102         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
1103         .u.blockdev_snapshot.data = &snapshot_data,
1104     };
1105     blockdev_do_action(&action, errp);
1106 }
1107 
1108 void qmp_blockdev_snapshot_internal_sync(const char *device,
1109                                          const char *name,
1110                                          Error **errp)
1111 {
1112     BlockdevSnapshotInternal snapshot = {
1113         .device = (char *) device,
1114         .name = (char *) name
1115     };
1116     TransactionAction action = {
1117         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
1118         .u.blockdev_snapshot_internal_sync.data = &snapshot,
1119     };
1120     blockdev_do_action(&action, errp);
1121 }
1122 
1123 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
1124                                                          const char *id,
1125                                                          const char *name,
1126                                                          Error **errp)
1127 {
1128     BlockDriverState *bs;
1129     QEMUSnapshotInfo sn;
1130     Error *local_err = NULL;
1131     SnapshotInfo *info = NULL;
1132     int ret;
1133 
1134     GLOBAL_STATE_CODE();
1135     GRAPH_RDLOCK_GUARD_MAINLOOP();
1136 
1137     bs = qmp_get_root_bs(device, errp);
1138     if (!bs) {
1139         return NULL;
1140     }
1141 
1142     if (!id && !name) {
1143         error_setg(errp, "Name or id must be provided");
1144         return NULL;
1145     }
1146 
1147     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
1148         return NULL;
1149     }
1150 
1151     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
1152     if (local_err) {
1153         error_propagate(errp, local_err);
1154         return NULL;
1155     }
1156     if (!ret) {
1157         error_setg(errp,
1158                    "Snapshot with id '%s' and name '%s' does not exist on "
1159                    "device '%s'",
1160                    STR_OR_NULL(id), STR_OR_NULL(name), device);
1161         return NULL;
1162     }
1163 
1164     bdrv_snapshot_delete(bs, id, name, &local_err);
1165     if (local_err) {
1166         error_propagate(errp, local_err);
1167         return NULL;
1168     }
1169 
1170     info = g_new0(SnapshotInfo, 1);
1171     info->id = g_strdup(sn.id_str);
1172     info->name = g_strdup(sn.name);
1173     info->date_nsec = sn.date_nsec;
1174     info->date_sec = sn.date_sec;
1175     info->vm_state_size = sn.vm_state_size;
1176     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
1177     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
1178     if (sn.icount != -1ULL) {
1179         info->icount = sn.icount;
1180         info->has_icount = true;
1181     }
1182 
1183     return info;
1184 }
1185 
1186 /* internal snapshot private data */
1187 typedef struct InternalSnapshotState {
1188     BlockDriverState *bs;
1189     QEMUSnapshotInfo sn;
1190     bool created;
1191 } InternalSnapshotState;
1192 
1193 static void internal_snapshot_abort(void *opaque);
1194 static void internal_snapshot_clean(void *opaque);
1195 TransactionActionDrv internal_snapshot_drv = {
1196     .abort = internal_snapshot_abort,
1197     .clean = internal_snapshot_clean,
1198 };
1199 
1200 static void internal_snapshot_action(BlockdevSnapshotInternal *internal,
1201                                      Transaction *tran, Error **errp)
1202 {
1203     Error *local_err = NULL;
1204     const char *device;
1205     const char *name;
1206     BlockDriverState *bs;
1207     QEMUSnapshotInfo old_sn, *sn;
1208     bool ret;
1209     int64_t rt;
1210     InternalSnapshotState *state = g_new0(InternalSnapshotState, 1);
1211     int ret1;
1212 
1213     GLOBAL_STATE_CODE();
1214     GRAPH_RDLOCK_GUARD_MAINLOOP();
1215 
1216     tran_add(tran, &internal_snapshot_drv, state);
1217 
1218     device = internal->device;
1219     name = internal->name;
1220 
1221     bs = qmp_get_root_bs(device, errp);
1222     if (!bs) {
1223         return;
1224     }
1225 
1226     state->bs = bs;
1227 
1228     /* Paired with .clean() */
1229     bdrv_drained_begin(bs);
1230 
1231     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
1232         return;
1233     }
1234 
1235     if (bdrv_is_read_only(bs)) {
1236         error_setg(errp, "Device '%s' is read only", device);
1237         return;
1238     }
1239 
1240     if (!bdrv_can_snapshot(bs)) {
1241         error_setg(errp, "Block format '%s' used by device '%s' "
1242                    "does not support internal snapshots",
1243                    bs->drv->format_name, device);
1244         return;
1245     }
1246 
1247     if (!strlen(name)) {
1248         error_setg(errp, "Name is empty");
1249         return;
1250     }
1251 
1252     /* check whether a snapshot with name exist */
1253     ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &old_sn,
1254                                             &local_err);
1255     if (local_err) {
1256         error_propagate(errp, local_err);
1257         return;
1258     } else if (ret) {
1259         error_setg(errp,
1260                    "Snapshot with name '%s' already exists on device '%s'",
1261                    name, device);
1262         return;
1263     }
1264 
1265     /* 3. take the snapshot */
1266     sn = &state->sn;
1267     pstrcpy(sn->name, sizeof(sn->name), name);
1268     rt = g_get_real_time();
1269     sn->date_sec = rt / G_USEC_PER_SEC;
1270     sn->date_nsec = (rt % G_USEC_PER_SEC) * 1000;
1271     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1272     if (replay_mode != REPLAY_MODE_NONE) {
1273         sn->icount = replay_get_current_icount();
1274     } else {
1275         sn->icount = -1ULL;
1276     }
1277 
1278     ret1 = bdrv_snapshot_create(bs, sn);
1279     if (ret1 < 0) {
1280         error_setg_errno(errp, -ret1,
1281                          "Failed to create snapshot '%s' on device '%s'",
1282                          name, device);
1283         return;
1284     }
1285 
1286     /* 4. succeed, mark a snapshot is created */
1287     state->created = true;
1288 }
1289 
1290 static void internal_snapshot_abort(void *opaque)
1291 {
1292     InternalSnapshotState *state = opaque;
1293     BlockDriverState *bs = state->bs;
1294     QEMUSnapshotInfo *sn = &state->sn;
1295     Error *local_error = NULL;
1296 
1297     GLOBAL_STATE_CODE();
1298     GRAPH_RDLOCK_GUARD_MAINLOOP();
1299 
1300     if (!state->created) {
1301         return;
1302     }
1303 
1304     if (bdrv_snapshot_delete(bs, sn->id_str, sn->name, &local_error) < 0) {
1305         error_reportf_err(local_error,
1306                           "Failed to delete snapshot with id '%s' and "
1307                           "name '%s' on device '%s' in abort: ",
1308                           sn->id_str, sn->name,
1309                           bdrv_get_device_name(bs));
1310     }
1311 }
1312 
1313 static void internal_snapshot_clean(void *opaque)
1314 {
1315     g_autofree InternalSnapshotState *state = opaque;
1316 
1317     if (!state->bs) {
1318         return;
1319     }
1320 
1321     bdrv_drained_end(state->bs);
1322 }
1323 
1324 /* external snapshot private data */
1325 typedef struct ExternalSnapshotState {
1326     BlockDriverState *old_bs;
1327     BlockDriverState *new_bs;
1328     bool overlay_appended;
1329 } ExternalSnapshotState;
1330 
1331 static void external_snapshot_commit(void *opaque);
1332 static void external_snapshot_abort(void *opaque);
1333 static void external_snapshot_clean(void *opaque);
1334 TransactionActionDrv external_snapshot_drv = {
1335     .commit = external_snapshot_commit,
1336     .abort = external_snapshot_abort,
1337     .clean = external_snapshot_clean,
1338 };
1339 
1340 static void external_snapshot_action(TransactionAction *action,
1341                                      Transaction *tran, Error **errp)
1342 {
1343     int ret;
1344     int flags = 0;
1345     QDict *options = NULL;
1346     Error *local_err = NULL;
1347     /* Device and node name of the image to generate the snapshot from */
1348     const char *device;
1349     const char *node_name;
1350     /* Reference to the new image (for 'blockdev-snapshot') */
1351     const char *snapshot_ref;
1352     /* File name of the new image (for 'blockdev-snapshot-sync') */
1353     const char *new_image_file;
1354     ExternalSnapshotState *state = g_new0(ExternalSnapshotState, 1);
1355     uint64_t perm, shared;
1356 
1357     /* TODO We'll eventually have to take a writer lock in this function */
1358     GRAPH_RDLOCK_GUARD_MAINLOOP();
1359 
1360     tran_add(tran, &external_snapshot_drv, state);
1361 
1362     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
1363      * purpose but a different set of parameters */
1364     switch (action->type) {
1365     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
1366         {
1367             BlockdevSnapshot *s = action->u.blockdev_snapshot.data;
1368             device = s->node;
1369             node_name = s->node;
1370             new_image_file = NULL;
1371             snapshot_ref = s->overlay;
1372         }
1373         break;
1374     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
1375         {
1376             BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1377             device = s->device;
1378             node_name = s->node_name;
1379             new_image_file = s->snapshot_file;
1380             snapshot_ref = NULL;
1381         }
1382         break;
1383     default:
1384         g_assert_not_reached();
1385     }
1386 
1387     /* start processing */
1388 
1389     state->old_bs = bdrv_lookup_bs(device, node_name, errp);
1390     if (!state->old_bs) {
1391         return;
1392     }
1393 
1394     /* Paired with .clean() */
1395     bdrv_drained_begin(state->old_bs);
1396 
1397     if (!bdrv_is_inserted(state->old_bs)) {
1398         error_setg(errp, "Device '%s' has no medium",
1399                    bdrv_get_device_or_node_name(state->old_bs));
1400         return;
1401     }
1402 
1403     if (bdrv_op_is_blocked(state->old_bs,
1404                            BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
1405         return;
1406     }
1407 
1408     if (!bdrv_is_read_only(state->old_bs)) {
1409         ret = bdrv_flush(state->old_bs);
1410         if (ret < 0) {
1411             error_setg_errno(errp, -ret, "Write to node '%s' failed",
1412                              bdrv_get_device_or_node_name(state->old_bs));
1413             return;
1414         }
1415     }
1416 
1417     if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
1418         BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1419         const char *format = s->format ?: "qcow2";
1420         enum NewImageMode mode;
1421         const char *snapshot_node_name = s->snapshot_node_name;
1422 
1423         if (node_name && !snapshot_node_name) {
1424             error_setg(errp, "New overlay node-name missing");
1425             return;
1426         }
1427 
1428         if (snapshot_node_name &&
1429             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
1430             error_setg(errp, "New overlay node-name already in use");
1431             return;
1432         }
1433 
1434         flags = state->old_bs->open_flags;
1435         flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ);
1436         flags |= BDRV_O_NO_BACKING;
1437 
1438         /* create new image w/backing file */
1439         mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1440         if (mode != NEW_IMAGE_MODE_EXISTING) {
1441             int64_t size = bdrv_getlength(state->old_bs);
1442             if (size < 0) {
1443                 error_setg_errno(errp, -size, "bdrv_getlength failed");
1444                 return;
1445             }
1446             bdrv_refresh_filename(state->old_bs);
1447 
1448             bdrv_img_create(new_image_file, format,
1449                             state->old_bs->filename,
1450                             state->old_bs->drv->format_name,
1451                             NULL, size, flags, false, &local_err);
1452 
1453             if (local_err) {
1454                 error_propagate(errp, local_err);
1455                 return;
1456             }
1457         }
1458 
1459         options = qdict_new();
1460         if (snapshot_node_name) {
1461             qdict_put_str(options, "node-name", snapshot_node_name);
1462         }
1463         qdict_put_str(options, "driver", format);
1464     }
1465 
1466     state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags,
1467                               errp);
1468 
1469     /* We will manually add the backing_hd field to the bs later */
1470     if (!state->new_bs) {
1471         return;
1472     }
1473 
1474     /*
1475      * Allow attaching a backing file to an overlay that's already in use only
1476      * if the parents don't assume that they are already seeing a valid image.
1477      * (Specifically, allow it as a mirror target, which is write-only access.)
1478      */
1479     bdrv_get_cumulative_perm(state->new_bs, &perm, &shared);
1480     if (perm & BLK_PERM_CONSISTENT_READ) {
1481         error_setg(errp, "The overlay is already in use");
1482         return;
1483     }
1484 
1485     if (state->new_bs->drv->is_filter) {
1486         error_setg(errp, "Filters cannot be used as overlays");
1487         return;
1488     }
1489 
1490     if (bdrv_cow_child(state->new_bs)) {
1491         error_setg(errp, "The overlay already has a backing image");
1492         return;
1493     }
1494 
1495     if (!state->new_bs->drv->supports_backing) {
1496         error_setg(errp, "The overlay does not support backing images");
1497         return;
1498     }
1499 
1500     ret = bdrv_append(state->new_bs, state->old_bs, errp);
1501     if (ret < 0) {
1502         return;
1503     }
1504     state->overlay_appended = true;
1505 }
1506 
1507 static void external_snapshot_commit(void *opaque)
1508 {
1509     ExternalSnapshotState *state = opaque;
1510 
1511     /* We don't need (or want) to use the transactional
1512      * bdrv_reopen_multiple() across all the entries at once, because we
1513      * don't want to abort all of them if one of them fails the reopen */
1514     if (!qatomic_read(&state->old_bs->copy_on_read)) {
1515         bdrv_reopen_set_read_only(state->old_bs, true, NULL);
1516     }
1517 }
1518 
1519 static void external_snapshot_abort(void *opaque)
1520 {
1521     ExternalSnapshotState *state = opaque;
1522     if (state->new_bs) {
1523         if (state->overlay_appended) {
1524             AioContext *aio_context;
1525             AioContext *tmp_context;
1526             int ret;
1527 
1528             aio_context = bdrv_get_aio_context(state->old_bs);
1529 
1530             bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
1531                                           close state->old_bs; we need it */
1532             bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
1533 
1534             /*
1535              * The call to bdrv_set_backing_hd() above returns state->old_bs to
1536              * the main AioContext. As we're still going to be using it, return
1537              * it to the AioContext it was before.
1538              */
1539             tmp_context = bdrv_get_aio_context(state->old_bs);
1540             if (aio_context != tmp_context) {
1541                 ret = bdrv_try_change_aio_context(state->old_bs,
1542                                                   aio_context, NULL, NULL);
1543                 assert(ret == 0);
1544             }
1545 
1546             bdrv_drained_begin(state->new_bs);
1547             bdrv_graph_wrlock();
1548             bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
1549             bdrv_graph_wrunlock();
1550             bdrv_drained_end(state->new_bs);
1551 
1552             bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
1553         }
1554     }
1555 }
1556 
1557 static void external_snapshot_clean(void *opaque)
1558 {
1559     g_autofree ExternalSnapshotState *state = opaque;
1560 
1561     if (!state->old_bs) {
1562         return;
1563     }
1564 
1565     bdrv_drained_end(state->old_bs);
1566     bdrv_unref(state->new_bs);
1567 }
1568 
1569 typedef struct DriveBackupState {
1570     BlockDriverState *bs;
1571     BlockJob *job;
1572 } DriveBackupState;
1573 
1574 static BlockJob *do_backup_common(BackupCommon *backup,
1575                                   BlockDriverState *bs,
1576                                   BlockDriverState *target_bs,
1577                                   AioContext *aio_context,
1578                                   JobTxn *txn, Error **errp);
1579 
1580 static void drive_backup_commit(void *opaque);
1581 static void drive_backup_abort(void *opaque);
1582 static void drive_backup_clean(void *opaque);
1583 TransactionActionDrv drive_backup_drv = {
1584     .commit = drive_backup_commit,
1585     .abort = drive_backup_abort,
1586     .clean = drive_backup_clean,
1587 };
1588 
1589 static void drive_backup_action(DriveBackup *backup,
1590                                 JobTxn *block_job_txn,
1591                                 Transaction *tran, Error **errp)
1592 {
1593     DriveBackupState *state = g_new0(DriveBackupState, 1);
1594     BlockDriverState *bs;
1595     BlockDriverState *target_bs;
1596     BlockDriverState *source = NULL;
1597     AioContext *aio_context;
1598     const char *format;
1599     QDict *options;
1600     Error *local_err = NULL;
1601     int flags;
1602     int64_t size;
1603     bool set_backing_hd = false;
1604     int ret;
1605 
1606     GLOBAL_STATE_CODE();
1607 
1608     tran_add(tran, &drive_backup_drv, state);
1609 
1610     if (!backup->has_mode) {
1611         backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1612     }
1613 
1614     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1615     if (!bs) {
1616         return;
1617     }
1618 
1619     if (!bs->drv) {
1620         error_setg(errp, "Device has no medium");
1621         return;
1622     }
1623 
1624     aio_context = bdrv_get_aio_context(bs);
1625 
1626     state->bs = bs;
1627     /* Paired with .clean() */
1628     bdrv_drained_begin(bs);
1629 
1630     format = backup->format;
1631     if (!format && backup->mode != NEW_IMAGE_MODE_EXISTING) {
1632         format = bs->drv->format_name;
1633     }
1634 
1635     /* Early check to avoid creating target */
1636     bdrv_graph_rdlock_main_loop();
1637     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
1638         bdrv_graph_rdunlock_main_loop();
1639         return;
1640     }
1641 
1642     flags = bs->open_flags | BDRV_O_RDWR;
1643 
1644     /*
1645      * See if we have a backing HD we can use to create our new image
1646      * on top of.
1647      */
1648     if (backup->sync == MIRROR_SYNC_MODE_TOP) {
1649         /*
1650          * Backup will not replace the source by the target, so none
1651          * of the filters skipped here will be removed (in contrast to
1652          * mirror).  Therefore, we can skip all of them when looking
1653          * for the first COW relationship.
1654          */
1655         source = bdrv_cow_bs(bdrv_skip_filters(bs));
1656         if (!source) {
1657             backup->sync = MIRROR_SYNC_MODE_FULL;
1658         }
1659     }
1660     if (backup->sync == MIRROR_SYNC_MODE_NONE) {
1661         source = bs;
1662         flags |= BDRV_O_NO_BACKING;
1663         set_backing_hd = true;
1664     }
1665     bdrv_graph_rdunlock_main_loop();
1666 
1667     size = bdrv_getlength(bs);
1668     if (size < 0) {
1669         error_setg_errno(errp, -size, "bdrv_getlength failed");
1670         return;
1671     }
1672 
1673     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
1674         assert(format);
1675         if (source) {
1676             /* Implicit filters should not appear in the filename */
1677             BlockDriverState *explicit_backing;
1678 
1679             bdrv_graph_rdlock_main_loop();
1680             explicit_backing = bdrv_skip_implicit_filters(source);
1681             bdrv_refresh_filename(explicit_backing);
1682             bdrv_graph_rdunlock_main_loop();
1683 
1684             bdrv_img_create(backup->target, format,
1685                             explicit_backing->filename,
1686                             explicit_backing->drv->format_name, NULL,
1687                             size, flags, false, &local_err);
1688         } else {
1689             bdrv_img_create(backup->target, format, NULL, NULL, NULL,
1690                             size, flags, false, &local_err);
1691         }
1692     }
1693 
1694     if (local_err) {
1695         error_propagate(errp, local_err);
1696         return;
1697     }
1698 
1699     options = qdict_new();
1700     qdict_put_str(options, "discard", "unmap");
1701     qdict_put_str(options, "detect-zeroes", "unmap");
1702     if (format) {
1703         qdict_put_str(options, "driver", format);
1704     }
1705 
1706     target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
1707     if (!target_bs) {
1708         return;
1709     }
1710 
1711     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1712     if (ret < 0) {
1713         bdrv_unref(target_bs);
1714         return;
1715     }
1716 
1717     if (set_backing_hd) {
1718         if (bdrv_set_backing_hd(target_bs, source, errp) < 0) {
1719             goto unref;
1720         }
1721     }
1722 
1723     state->job = do_backup_common(qapi_DriveBackup_base(backup),
1724                                   bs, target_bs, aio_context,
1725                                   block_job_txn, errp);
1726 
1727 unref:
1728     bdrv_unref(target_bs);
1729 }
1730 
1731 static void drive_backup_commit(void *opaque)
1732 {
1733     DriveBackupState *state = opaque;
1734 
1735     assert(state->job);
1736     job_start(&state->job->job);
1737 }
1738 
1739 static void drive_backup_abort(void *opaque)
1740 {
1741     DriveBackupState *state = opaque;
1742 
1743     if (state->job) {
1744         job_cancel_sync(&state->job->job, true);
1745     }
1746 }
1747 
1748 static void drive_backup_clean(void *opaque)
1749 {
1750     g_autofree DriveBackupState *state = opaque;
1751 
1752     if (!state->bs) {
1753         return;
1754     }
1755 
1756     bdrv_drained_end(state->bs);
1757 }
1758 
1759 typedef struct BlockdevBackupState {
1760     BlockDriverState *bs;
1761     BlockJob *job;
1762 } BlockdevBackupState;
1763 
1764 static void blockdev_backup_commit(void *opaque);
1765 static void blockdev_backup_abort(void *opaque);
1766 static void blockdev_backup_clean(void *opaque);
1767 TransactionActionDrv blockdev_backup_drv = {
1768     .commit = blockdev_backup_commit,
1769     .abort = blockdev_backup_abort,
1770     .clean = blockdev_backup_clean,
1771 };
1772 
1773 static void blockdev_backup_action(BlockdevBackup *backup,
1774                                    JobTxn *block_job_txn,
1775                                    Transaction *tran, Error **errp)
1776 {
1777     BlockdevBackupState *state = g_new0(BlockdevBackupState, 1);
1778     BlockDriverState *bs;
1779     BlockDriverState *target_bs;
1780     AioContext *aio_context;
1781     int ret;
1782 
1783     tran_add(tran, &blockdev_backup_drv, state);
1784 
1785     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1786     if (!bs) {
1787         return;
1788     }
1789 
1790     target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);
1791     if (!target_bs) {
1792         return;
1793     }
1794 
1795     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1796     aio_context = bdrv_get_aio_context(bs);
1797 
1798     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1799     if (ret < 0) {
1800         return;
1801     }
1802 
1803     state->bs = bs;
1804 
1805     /* Paired with .clean() */
1806     bdrv_drained_begin(state->bs);
1807 
1808     state->job = do_backup_common(qapi_BlockdevBackup_base(backup),
1809                                   bs, target_bs, aio_context,
1810                                   block_job_txn, errp);
1811 }
1812 
1813 static void blockdev_backup_commit(void *opaque)
1814 {
1815     BlockdevBackupState *state = opaque;
1816 
1817     assert(state->job);
1818     job_start(&state->job->job);
1819 }
1820 
1821 static void blockdev_backup_abort(void *opaque)
1822 {
1823     BlockdevBackupState *state = opaque;
1824 
1825     if (state->job) {
1826         job_cancel_sync(&state->job->job, true);
1827     }
1828 }
1829 
1830 static void blockdev_backup_clean(void *opaque)
1831 {
1832     g_autofree BlockdevBackupState *state = opaque;
1833 
1834     if (!state->bs) {
1835         return;
1836     }
1837 
1838     bdrv_drained_end(state->bs);
1839 }
1840 
1841 typedef struct BlockDirtyBitmapState {
1842     BdrvDirtyBitmap *bitmap;
1843     BlockDriverState *bs;
1844     HBitmap *backup;
1845     bool was_enabled;
1846 } BlockDirtyBitmapState;
1847 
1848 static void block_dirty_bitmap_add_abort(void *opaque);
1849 TransactionActionDrv block_dirty_bitmap_add_drv = {
1850     .abort = block_dirty_bitmap_add_abort,
1851     .clean = g_free,
1852 };
1853 
1854 static void block_dirty_bitmap_add_action(BlockDirtyBitmapAdd *action,
1855                                           Transaction *tran, Error **errp)
1856 {
1857     Error *local_err = NULL;
1858     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1859 
1860     tran_add(tran, &block_dirty_bitmap_add_drv, state);
1861 
1862     /* AIO context taken and released within qmp_block_dirty_bitmap_add */
1863     qmp_block_dirty_bitmap_add(action->node, action->name,
1864                                action->has_granularity, action->granularity,
1865                                action->has_persistent, action->persistent,
1866                                action->has_disabled, action->disabled,
1867                                &local_err);
1868 
1869     if (!local_err) {
1870         state->bitmap = block_dirty_bitmap_lookup(action->node, action->name,
1871                                                   NULL, &error_abort);
1872     } else {
1873         error_propagate(errp, local_err);
1874     }
1875 }
1876 
1877 static void block_dirty_bitmap_add_abort(void *opaque)
1878 {
1879     BlockDirtyBitmapState *state = opaque;
1880 
1881     if (state->bitmap) {
1882         bdrv_release_dirty_bitmap(state->bitmap);
1883     }
1884 }
1885 
1886 static void block_dirty_bitmap_restore(void *opaque);
1887 static void block_dirty_bitmap_free_backup(void *opaque);
1888 TransactionActionDrv block_dirty_bitmap_clear_drv = {
1889     .abort = block_dirty_bitmap_restore,
1890     .commit = block_dirty_bitmap_free_backup,
1891     .clean = g_free,
1892 };
1893 
1894 static void block_dirty_bitmap_clear_action(BlockDirtyBitmap *action,
1895                                             Transaction *tran, Error **errp)
1896 {
1897     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1898 
1899     tran_add(tran, &block_dirty_bitmap_clear_drv, state);
1900 
1901     state->bitmap = block_dirty_bitmap_lookup(action->node,
1902                                               action->name,
1903                                               &state->bs,
1904                                               errp);
1905     if (!state->bitmap) {
1906         return;
1907     }
1908 
1909     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_DEFAULT, errp)) {
1910         return;
1911     }
1912 
1913     bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
1914 }
1915 
1916 static void block_dirty_bitmap_restore(void *opaque)
1917 {
1918     BlockDirtyBitmapState *state = opaque;
1919 
1920     if (state->backup) {
1921         bdrv_restore_dirty_bitmap(state->bitmap, state->backup);
1922     }
1923 }
1924 
1925 static void block_dirty_bitmap_free_backup(void *opaque)
1926 {
1927     BlockDirtyBitmapState *state = opaque;
1928 
1929     hbitmap_free(state->backup);
1930 }
1931 
1932 static void block_dirty_bitmap_enable_abort(void *opaque);
1933 TransactionActionDrv block_dirty_bitmap_enable_drv = {
1934     .abort = block_dirty_bitmap_enable_abort,
1935     .clean = g_free,
1936 };
1937 
1938 static void block_dirty_bitmap_enable_action(BlockDirtyBitmap *action,
1939                                              Transaction *tran, Error **errp)
1940 {
1941     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1942 
1943     tran_add(tran, &block_dirty_bitmap_enable_drv, state);
1944 
1945     state->bitmap = block_dirty_bitmap_lookup(action->node,
1946                                               action->name,
1947                                               NULL,
1948                                               errp);
1949     if (!state->bitmap) {
1950         return;
1951     }
1952 
1953     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
1954         return;
1955     }
1956 
1957     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
1958     bdrv_enable_dirty_bitmap(state->bitmap);
1959 }
1960 
1961 static void block_dirty_bitmap_enable_abort(void *opaque)
1962 {
1963     BlockDirtyBitmapState *state = opaque;
1964 
1965     if (!state->was_enabled) {
1966         bdrv_disable_dirty_bitmap(state->bitmap);
1967     }
1968 }
1969 
1970 static void block_dirty_bitmap_disable_abort(void *opaque);
1971 TransactionActionDrv block_dirty_bitmap_disable_drv = {
1972     .abort = block_dirty_bitmap_disable_abort,
1973     .clean = g_free,
1974 };
1975 
1976 static void block_dirty_bitmap_disable_action(BlockDirtyBitmap *action,
1977                                               Transaction *tran, Error **errp)
1978 {
1979     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1980 
1981     tran_add(tran, &block_dirty_bitmap_disable_drv, state);
1982 
1983     state->bitmap = block_dirty_bitmap_lookup(action->node,
1984                                               action->name,
1985                                               NULL,
1986                                               errp);
1987     if (!state->bitmap) {
1988         return;
1989     }
1990 
1991     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
1992         return;
1993     }
1994 
1995     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
1996     bdrv_disable_dirty_bitmap(state->bitmap);
1997 }
1998 
1999 static void block_dirty_bitmap_disable_abort(void *opaque)
2000 {
2001     BlockDirtyBitmapState *state = opaque;
2002 
2003     if (state->was_enabled) {
2004         bdrv_enable_dirty_bitmap(state->bitmap);
2005     }
2006 }
2007 
2008 TransactionActionDrv block_dirty_bitmap_merge_drv = {
2009     .commit = block_dirty_bitmap_free_backup,
2010     .abort = block_dirty_bitmap_restore,
2011     .clean = g_free,
2012 };
2013 
2014 static void block_dirty_bitmap_merge_action(BlockDirtyBitmapMerge *action,
2015                                             Transaction *tran, Error **errp)
2016 {
2017     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2018 
2019     tran_add(tran, &block_dirty_bitmap_merge_drv, state);
2020 
2021     state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
2022                                              action->bitmaps, &state->backup,
2023                                              errp);
2024 }
2025 
2026 static void block_dirty_bitmap_remove_commit(void *opaque);
2027 static void block_dirty_bitmap_remove_abort(void *opaque);
2028 TransactionActionDrv block_dirty_bitmap_remove_drv = {
2029     .commit = block_dirty_bitmap_remove_commit,
2030     .abort = block_dirty_bitmap_remove_abort,
2031     .clean = g_free,
2032 };
2033 
2034 static void block_dirty_bitmap_remove_action(BlockDirtyBitmap *action,
2035                                              Transaction *tran, Error **errp)
2036 {
2037     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2038 
2039     tran_add(tran, &block_dirty_bitmap_remove_drv, state);
2040 
2041 
2042     state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
2043                                               false, &state->bs, errp);
2044     if (state->bitmap) {
2045         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
2046         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
2047     }
2048 }
2049 
2050 static void block_dirty_bitmap_remove_abort(void *opaque)
2051 {
2052     BlockDirtyBitmapState *state = opaque;
2053 
2054     if (state->bitmap) {
2055         bdrv_dirty_bitmap_skip_store(state->bitmap, false);
2056         bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2057     }
2058 }
2059 
2060 static void block_dirty_bitmap_remove_commit(void *opaque)
2061 {
2062     BlockDirtyBitmapState *state = opaque;
2063 
2064     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2065     bdrv_release_dirty_bitmap(state->bitmap);
2066 }
2067 
2068 static void abort_commit(void *opaque);
2069 TransactionActionDrv abort_drv = {
2070     .commit = abort_commit,
2071 };
2072 
2073 static void abort_action(Transaction *tran, Error **errp)
2074 {
2075     tran_add(tran, &abort_drv, NULL);
2076     error_setg(errp, "Transaction aborted using Abort action");
2077 }
2078 
2079 static void abort_commit(void *opaque)
2080 {
2081     g_assert_not_reached(); /* this action never succeeds */
2082 }
2083 
2084 static void transaction_action(TransactionAction *act, JobTxn *block_job_txn,
2085                                Transaction *tran, Error **errp)
2086 {
2087     switch (act->type) {
2088     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
2089     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
2090         external_snapshot_action(act, tran, errp);
2091         return;
2092     case TRANSACTION_ACTION_KIND_DRIVE_BACKUP:
2093         drive_backup_action(act->u.drive_backup.data,
2094                             block_job_txn, tran, errp);
2095         return;
2096     case TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP:
2097         blockdev_backup_action(act->u.blockdev_backup.data,
2098                                block_job_txn, tran, errp);
2099         return;
2100     case TRANSACTION_ACTION_KIND_ABORT:
2101         abort_action(tran, errp);
2102         return;
2103     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC:
2104         internal_snapshot_action(act->u.blockdev_snapshot_internal_sync.data,
2105                                  tran, errp);
2106         return;
2107     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD:
2108         block_dirty_bitmap_add_action(act->u.block_dirty_bitmap_add.data,
2109                                       tran, errp);
2110         return;
2111     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR:
2112         block_dirty_bitmap_clear_action(act->u.block_dirty_bitmap_clear.data,
2113                                         tran, errp);
2114         return;
2115     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE:
2116         block_dirty_bitmap_enable_action(act->u.block_dirty_bitmap_enable.data,
2117                                          tran, errp);
2118         return;
2119     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE:
2120         block_dirty_bitmap_disable_action(
2121                 act->u.block_dirty_bitmap_disable.data, tran, errp);
2122         return;
2123     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE:
2124         block_dirty_bitmap_merge_action(act->u.block_dirty_bitmap_merge.data,
2125                                         tran, errp);
2126         return;
2127     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_REMOVE:
2128         block_dirty_bitmap_remove_action(act->u.block_dirty_bitmap_remove.data,
2129                                          tran, errp);
2130         return;
2131     /*
2132      * Where are transactions for MIRROR, COMMIT and STREAM?
2133      * Although these blockjobs use transaction callbacks like the backup job,
2134      * these jobs do not necessarily adhere to transaction semantics.
2135      * These jobs may not fully undo all of their actions on abort, nor do they
2136      * necessarily work in transactions with more than one job in them.
2137      */
2138     case TRANSACTION_ACTION_KIND__MAX:
2139     default:
2140         g_assert_not_reached();
2141     };
2142 }
2143 
2144 
2145 /*
2146  * 'Atomic' group operations.  The operations are performed as a set, and if
2147  * any fail then we roll back all operations in the group.
2148  *
2149  * Always run under BQL.
2150  */
2151 void qmp_transaction(TransactionActionList *actions,
2152                      struct TransactionProperties *properties,
2153                      Error **errp)
2154 {
2155     TransactionActionList *act;
2156     JobTxn *block_job_txn = NULL;
2157     Error *local_err = NULL;
2158     Transaction *tran;
2159     ActionCompletionMode comp_mode =
2160         properties ? properties->completion_mode :
2161         ACTION_COMPLETION_MODE_INDIVIDUAL;
2162 
2163     GLOBAL_STATE_CODE();
2164 
2165     /* Does this transaction get canceled as a group on failure?
2166      * If not, we don't really need to make a JobTxn.
2167      */
2168     if (comp_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
2169         for (act = actions; act; act = act->next) {
2170             TransactionActionKind type = act->value->type;
2171 
2172             if (type != TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP &&
2173                 type != TRANSACTION_ACTION_KIND_DRIVE_BACKUP)
2174             {
2175                 error_setg(errp,
2176                            "Action '%s' does not support transaction property "
2177                            "completion-mode = %s",
2178                            TransactionActionKind_str(type),
2179                            ActionCompletionMode_str(comp_mode));
2180                 return;
2181             }
2182         }
2183 
2184         block_job_txn = job_txn_new();
2185     }
2186 
2187     /* drain all i/o before any operations */
2188     bdrv_drain_all();
2189 
2190     tran = tran_new();
2191 
2192     /* We don't do anything in this loop that commits us to the operations */
2193     for (act = actions; act; act = act->next) {
2194         transaction_action(act->value, block_job_txn, tran, &local_err);
2195         if (local_err) {
2196             error_propagate(errp, local_err);
2197             goto delete_and_fail;
2198         }
2199     }
2200 
2201     tran_commit(tran);
2202 
2203     /* success */
2204     goto exit;
2205 
2206 delete_and_fail:
2207     /* failure, and it is all-or-none; roll back all operations */
2208     tran_abort(tran);
2209 exit:
2210     job_txn_unref(block_job_txn);
2211 }
2212 
2213 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
2214                                                               const char *name,
2215                                                               Error **errp)
2216 {
2217     BdrvDirtyBitmap *bitmap;
2218     BlockDriverState *bs;
2219     BlockDirtyBitmapSha256 *ret = NULL;
2220     char *sha256;
2221 
2222     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
2223     if (!bitmap || !bs) {
2224         return NULL;
2225     }
2226 
2227     sha256 = bdrv_dirty_bitmap_sha256(bitmap, errp);
2228     if (sha256 == NULL) {
2229         return NULL;
2230     }
2231 
2232     ret = g_new(BlockDirtyBitmapSha256, 1);
2233     ret->sha256 = sha256;
2234 
2235     return ret;
2236 }
2237 
2238 void coroutine_fn qmp_block_resize(const char *device, const char *node_name,
2239                                    int64_t size, Error **errp)
2240 {
2241     Error *local_err = NULL;
2242     BlockBackend *blk;
2243     BlockDriverState *bs;
2244     AioContext *old_ctx;
2245 
2246     bs = bdrv_lookup_bs(device, node_name, &local_err);
2247     if (local_err) {
2248         error_propagate(errp, local_err);
2249         return;
2250     }
2251 
2252     if (size < 0) {
2253         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
2254         return;
2255     }
2256 
2257     bdrv_graph_co_rdlock();
2258     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, errp)) {
2259         bdrv_graph_co_rdunlock();
2260         return;
2261     }
2262     bdrv_graph_co_rdunlock();
2263 
2264     blk = blk_co_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, errp);
2265     if (!blk) {
2266         return;
2267     }
2268 
2269     bdrv_drained_begin(bs);
2270 
2271     old_ctx = bdrv_co_enter(bs);
2272     blk_co_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
2273     bdrv_co_leave(bs, old_ctx);
2274 
2275     bdrv_drained_end(bs);
2276     blk_co_unref(blk);
2277 }
2278 
2279 void qmp_block_stream(const char *job_id, const char *device,
2280                       const char *base,
2281                       const char *base_node,
2282                       const char *backing_file,
2283                       bool has_backing_mask_protocol,
2284                       bool backing_mask_protocol,
2285                       const char *bottom,
2286                       bool has_speed, int64_t speed,
2287                       bool has_on_error, BlockdevOnError on_error,
2288                       const char *filter_node_name,
2289                       bool has_auto_finalize, bool auto_finalize,
2290                       bool has_auto_dismiss, bool auto_dismiss,
2291                       Error **errp)
2292 {
2293     BlockDriverState *bs, *iter, *iter_end;
2294     BlockDriverState *base_bs = NULL;
2295     BlockDriverState *bottom_bs = NULL;
2296     AioContext *aio_context;
2297     Error *local_err = NULL;
2298     int job_flags = JOB_DEFAULT;
2299 
2300     GLOBAL_STATE_CODE();
2301 
2302     if (base && base_node) {
2303         error_setg(errp, "'base' and 'base-node' cannot be specified "
2304                    "at the same time");
2305         return;
2306     }
2307 
2308     if (base && bottom) {
2309         error_setg(errp, "'base' and 'bottom' cannot be specified "
2310                    "at the same time");
2311         return;
2312     }
2313 
2314     if (bottom && base_node) {
2315         error_setg(errp, "'bottom' and 'base-node' cannot be specified "
2316                    "at the same time");
2317         return;
2318     }
2319 
2320     if (!has_backing_mask_protocol) {
2321         backing_mask_protocol = false;
2322     }
2323 
2324     if (!has_on_error) {
2325         on_error = BLOCKDEV_ON_ERROR_REPORT;
2326     }
2327 
2328     bs = bdrv_lookup_bs(device, device, errp);
2329     if (!bs) {
2330         return;
2331     }
2332 
2333     aio_context = bdrv_get_aio_context(bs);
2334 
2335     bdrv_graph_rdlock_main_loop();
2336     if (base) {
2337         base_bs = bdrv_find_backing_image(bs, base);
2338         if (base_bs == NULL) {
2339             error_setg(errp, "Can't find '%s' in the backing chain", base);
2340             goto out_rdlock;
2341         }
2342         assert(bdrv_get_aio_context(base_bs) == aio_context);
2343     }
2344 
2345     if (base_node) {
2346         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2347         if (!base_bs) {
2348             goto out_rdlock;
2349         }
2350         if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) {
2351             error_setg(errp, "Node '%s' is not a backing image of '%s'",
2352                        base_node, device);
2353             goto out_rdlock;
2354         }
2355         assert(bdrv_get_aio_context(base_bs) == aio_context);
2356 
2357         bdrv_refresh_filename(base_bs);
2358     }
2359 
2360     if (bottom) {
2361         bottom_bs = bdrv_lookup_bs(NULL, bottom, errp);
2362         if (!bottom_bs) {
2363             goto out_rdlock;
2364         }
2365         if (!bottom_bs->drv) {
2366             error_setg(errp, "Node '%s' is not open", bottom);
2367             goto out_rdlock;
2368         }
2369         if (bottom_bs->drv->is_filter) {
2370             error_setg(errp, "Node '%s' is a filter, use a non-filter node "
2371                        "as 'bottom'", bottom);
2372             goto out_rdlock;
2373         }
2374         if (!bdrv_chain_contains(bs, bottom_bs)) {
2375             error_setg(errp, "Node '%s' is not in a chain starting from '%s'",
2376                        bottom, device);
2377             goto out_rdlock;
2378         }
2379         assert(bdrv_get_aio_context(bottom_bs) == aio_context);
2380     }
2381 
2382     /*
2383      * Check for op blockers in the whole chain between bs and base (or bottom)
2384      */
2385     iter_end = bottom ? bdrv_filter_or_cow_bs(bottom_bs) : base_bs;
2386     for (iter = bs; iter && iter != iter_end;
2387          iter = bdrv_filter_or_cow_bs(iter))
2388     {
2389         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
2390             goto out_rdlock;
2391         }
2392     }
2393     bdrv_graph_rdunlock_main_loop();
2394 
2395     /* if we are streaming the entire chain, the result will have no backing
2396      * file, and specifying one is therefore an error */
2397     if (!base_bs && backing_file) {
2398         error_setg(errp, "backing file specified, but streaming the "
2399                          "entire chain");
2400         return;
2401     }
2402 
2403     if (has_auto_finalize && !auto_finalize) {
2404         job_flags |= JOB_MANUAL_FINALIZE;
2405     }
2406     if (has_auto_dismiss && !auto_dismiss) {
2407         job_flags |= JOB_MANUAL_DISMISS;
2408     }
2409 
2410     stream_start(job_id, bs, base_bs, backing_file,
2411                  backing_mask_protocol,
2412                  bottom_bs, job_flags, has_speed ? speed : 0, on_error,
2413                  filter_node_name, &local_err);
2414     if (local_err) {
2415         error_propagate(errp, local_err);
2416         return;
2417     }
2418 
2419     trace_qmp_block_stream(bs);
2420     return;
2421 
2422 out_rdlock:
2423     bdrv_graph_rdunlock_main_loop();
2424 }
2425 
2426 void qmp_block_commit(const char *job_id, const char *device,
2427                       const char *base_node,
2428                       const char *base,
2429                       const char *top_node,
2430                       const char *top,
2431                       const char *backing_file,
2432                       bool has_backing_mask_protocol,
2433                       bool backing_mask_protocol,
2434                       bool has_speed, int64_t speed,
2435                       bool has_on_error, BlockdevOnError on_error,
2436                       const char *filter_node_name,
2437                       bool has_auto_finalize, bool auto_finalize,
2438                       bool has_auto_dismiss, bool auto_dismiss,
2439                       Error **errp)
2440 {
2441     BlockDriverState *bs;
2442     BlockDriverState *iter;
2443     BlockDriverState *base_bs, *top_bs;
2444     AioContext *aio_context;
2445     Error *local_err = NULL;
2446     int job_flags = JOB_DEFAULT;
2447     uint64_t top_perm, top_shared;
2448 
2449     /* TODO We'll eventually have to take a writer lock in this function */
2450     GRAPH_RDLOCK_GUARD_MAINLOOP();
2451 
2452     if (!has_speed) {
2453         speed = 0;
2454     }
2455     if (!has_on_error) {
2456         on_error = BLOCKDEV_ON_ERROR_REPORT;
2457     }
2458     if (has_auto_finalize && !auto_finalize) {
2459         job_flags |= JOB_MANUAL_FINALIZE;
2460     }
2461     if (has_auto_dismiss && !auto_dismiss) {
2462         job_flags |= JOB_MANUAL_DISMISS;
2463     }
2464     if (!has_backing_mask_protocol) {
2465         backing_mask_protocol = false;
2466     }
2467 
2468     /* Important Note:
2469      *  libvirt relies on the DeviceNotFound error class in order to probe for
2470      *  live commit feature versions; for this to work, we must make sure to
2471      *  perform the device lookup before any generic errors that may occur in a
2472      *  scenario in which all optional arguments are omitted. */
2473     bs = qmp_get_root_bs(device, &local_err);
2474     if (!bs) {
2475         bs = bdrv_lookup_bs(device, device, NULL);
2476         if (!bs) {
2477             error_free(local_err);
2478             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
2479                       "Device '%s' not found", device);
2480         } else {
2481             error_propagate(errp, local_err);
2482         }
2483         return;
2484     }
2485 
2486     aio_context = bdrv_get_aio_context(bs);
2487 
2488     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
2489         return;
2490     }
2491 
2492     /* default top_bs is the active layer */
2493     top_bs = bs;
2494 
2495     if (top_node && top) {
2496         error_setg(errp, "'top-node' and 'top' are mutually exclusive");
2497         return;
2498     } else if (top_node) {
2499         top_bs = bdrv_lookup_bs(NULL, top_node, errp);
2500         if (top_bs == NULL) {
2501             return;
2502         }
2503         if (!bdrv_chain_contains(bs, top_bs)) {
2504             error_setg(errp, "'%s' is not in this backing file chain",
2505                        top_node);
2506             return;
2507         }
2508     } else if (top) {
2509         /* This strcmp() is just a shortcut, there is no need to
2510          * refresh @bs's filename.  If it mismatches,
2511          * bdrv_find_backing_image() will do the refresh and may still
2512          * return @bs. */
2513         if (strcmp(bs->filename, top) != 0) {
2514             top_bs = bdrv_find_backing_image(bs, top);
2515         }
2516     }
2517 
2518     if (top_bs == NULL) {
2519         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
2520         return;
2521     }
2522 
2523     assert(bdrv_get_aio_context(top_bs) == aio_context);
2524 
2525     if (base_node && base) {
2526         error_setg(errp, "'base-node' and 'base' are mutually exclusive");
2527         return;
2528     } else if (base_node) {
2529         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2530         if (base_bs == NULL) {
2531             return;
2532         }
2533         if (!bdrv_chain_contains(top_bs, base_bs)) {
2534             error_setg(errp, "'%s' is not in this backing file chain",
2535                        base_node);
2536             return;
2537         }
2538     } else if (base) {
2539         base_bs = bdrv_find_backing_image(top_bs, base);
2540         if (base_bs == NULL) {
2541             error_setg(errp, "Can't find '%s' in the backing chain", base);
2542             return;
2543         }
2544     } else {
2545         base_bs = bdrv_find_base(top_bs);
2546         if (base_bs == NULL) {
2547             error_setg(errp, "There is no backimg image");
2548             return;
2549         }
2550     }
2551 
2552     assert(bdrv_get_aio_context(base_bs) == aio_context);
2553 
2554     for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs);
2555          iter = bdrv_filter_or_cow_bs(iter))
2556     {
2557         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2558             return;
2559         }
2560     }
2561 
2562     /* Do not allow attempts to commit an image into itself */
2563     if (top_bs == base_bs) {
2564         error_setg(errp, "cannot commit an image into itself");
2565         return;
2566     }
2567 
2568     /*
2569      * Active commit is required if and only if someone has taken a
2570      * WRITE permission on the top node.  Historically, we have always
2571      * used active commit for top nodes, so continue that practice
2572      * lest we possibly break clients that rely on this behavior, e.g.
2573      * to later attach this node to a writing parent.
2574      * (Active commit is never really wrong.)
2575      */
2576     bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared);
2577     if (top_perm & BLK_PERM_WRITE ||
2578         bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs))
2579     {
2580         if (backing_file) {
2581             if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) {
2582                 error_setg(errp, "'backing-file' specified,"
2583                                  " but 'top' is the active layer");
2584             } else {
2585                 error_setg(errp, "'backing-file' specified, but 'top' has a "
2586                                  "writer on it");
2587             }
2588             return;
2589         }
2590         if (!job_id) {
2591             /*
2592              * Emulate here what block_job_create() does, because it
2593              * is possible that @bs != @top_bs (the block job should
2594              * be named after @bs, even if @top_bs is the actual
2595              * source)
2596              */
2597             job_id = bdrv_get_device_name(bs);
2598         }
2599         commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error,
2600                             filter_node_name, NULL, NULL, false, &local_err);
2601     } else {
2602         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
2603         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2604             return;
2605         }
2606         commit_start(job_id, bs, base_bs, top_bs, job_flags,
2607                      speed, on_error, backing_file,
2608                      backing_mask_protocol,
2609                      filter_node_name, &local_err);
2610     }
2611     if (local_err != NULL) {
2612         error_propagate(errp, local_err);
2613         return;
2614     }
2615 }
2616 
2617 /* Common QMP interface for drive-backup and blockdev-backup */
2618 static BlockJob *do_backup_common(BackupCommon *backup,
2619                                   BlockDriverState *bs,
2620                                   BlockDriverState *target_bs,
2621                                   AioContext *aio_context,
2622                                   JobTxn *txn, Error **errp)
2623 {
2624     BlockJob *job = NULL;
2625     BdrvDirtyBitmap *bmap = NULL;
2626     BackupPerf perf = { .max_workers = 64 };
2627     int job_flags = JOB_DEFAULT;
2628 
2629     if (!backup->has_speed) {
2630         backup->speed = 0;
2631     }
2632     if (!backup->has_on_source_error) {
2633         backup->on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2634     }
2635     if (!backup->has_on_target_error) {
2636         backup->on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2637     }
2638     if (!backup->has_auto_finalize) {
2639         backup->auto_finalize = true;
2640     }
2641     if (!backup->has_auto_dismiss) {
2642         backup->auto_dismiss = true;
2643     }
2644     if (!backup->has_compress) {
2645         backup->compress = false;
2646     }
2647 
2648     if (backup->x_perf) {
2649         if (backup->x_perf->has_use_copy_range) {
2650             perf.use_copy_range = backup->x_perf->use_copy_range;
2651         }
2652         if (backup->x_perf->has_max_workers) {
2653             perf.max_workers = backup->x_perf->max_workers;
2654         }
2655         if (backup->x_perf->has_max_chunk) {
2656             perf.max_chunk = backup->x_perf->max_chunk;
2657         }
2658     }
2659 
2660     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||
2661         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
2662         /* done before desugaring 'incremental' to print the right message */
2663         if (!backup->bitmap) {
2664             error_setg(errp, "must provide a valid bitmap name for "
2665                        "'%s' sync mode", MirrorSyncMode_str(backup->sync));
2666             return NULL;
2667         }
2668     }
2669 
2670     if (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL) {
2671         if (backup->has_bitmap_mode &&
2672             backup->bitmap_mode != BITMAP_SYNC_MODE_ON_SUCCESS) {
2673             error_setg(errp, "Bitmap sync mode must be '%s' "
2674                        "when using sync mode '%s'",
2675                        BitmapSyncMode_str(BITMAP_SYNC_MODE_ON_SUCCESS),
2676                        MirrorSyncMode_str(backup->sync));
2677             return NULL;
2678         }
2679         backup->has_bitmap_mode = true;
2680         backup->sync = MIRROR_SYNC_MODE_BITMAP;
2681         backup->bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
2682     }
2683 
2684     if (backup->bitmap) {
2685         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
2686         if (!bmap) {
2687             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
2688             return NULL;
2689         }
2690         if (!backup->has_bitmap_mode) {
2691             error_setg(errp, "Bitmap sync mode must be given "
2692                        "when providing a bitmap");
2693             return NULL;
2694         }
2695         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2696             return NULL;
2697         }
2698 
2699         /* This does not produce a useful bitmap artifact: */
2700         if (backup->sync == MIRROR_SYNC_MODE_NONE) {
2701             error_setg(errp, "sync mode '%s' does not produce meaningful bitmap"
2702                        " outputs", MirrorSyncMode_str(backup->sync));
2703             return NULL;
2704         }
2705 
2706         /* If the bitmap isn't used for input or output, this is useless: */
2707         if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER &&
2708             backup->sync != MIRROR_SYNC_MODE_BITMAP) {
2709             error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect"
2710                        " when combined with sync mode '%s'",
2711                        BitmapSyncMode_str(backup->bitmap_mode),
2712                        MirrorSyncMode_str(backup->sync));
2713             return NULL;
2714         }
2715     }
2716 
2717     if (!backup->bitmap && backup->has_bitmap_mode) {
2718         error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
2719         return NULL;
2720     }
2721 
2722     if (!backup->auto_finalize) {
2723         job_flags |= JOB_MANUAL_FINALIZE;
2724     }
2725     if (!backup->auto_dismiss) {
2726         job_flags |= JOB_MANUAL_DISMISS;
2727     }
2728 
2729     job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
2730                             backup->sync, bmap, backup->bitmap_mode,
2731                             backup->compress, backup->discard_source,
2732                             backup->filter_node_name,
2733                             &perf,
2734                             backup->on_source_error,
2735                             backup->on_target_error,
2736                             job_flags, NULL, NULL, txn, errp);
2737     return job;
2738 }
2739 
2740 void qmp_drive_backup(DriveBackup *backup, Error **errp)
2741 {
2742     TransactionAction action = {
2743         .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
2744         .u.drive_backup.data = backup,
2745     };
2746     blockdev_do_action(&action, errp);
2747 }
2748 
2749 BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
2750                                                  bool flat,
2751                                                  Error **errp)
2752 {
2753     bool return_flat = has_flat && flat;
2754 
2755     return bdrv_named_nodes_list(return_flat, errp);
2756 }
2757 
2758 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
2759 {
2760     GRAPH_RDLOCK_GUARD_MAINLOOP();
2761 
2762     return bdrv_get_xdbg_block_graph(errp);
2763 }
2764 
2765 void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)
2766 {
2767     TransactionAction action = {
2768         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,
2769         .u.blockdev_backup.data = backup,
2770     };
2771     blockdev_do_action(&action, errp);
2772 }
2773 
2774 /* Parameter check and block job starting for drive mirroring.
2775  * Caller should hold @device and @target's aio context (must be the same).
2776  **/
2777 static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
2778                                    BlockDriverState *target,
2779                                    const char *replaces,
2780                                    enum MirrorSyncMode sync,
2781                                    BlockMirrorBackingMode backing_mode,
2782                                    bool zero_target,
2783                                    bool has_speed, int64_t speed,
2784                                    bool has_granularity, uint32_t granularity,
2785                                    bool has_buf_size, int64_t buf_size,
2786                                    bool has_on_source_error,
2787                                    BlockdevOnError on_source_error,
2788                                    bool has_on_target_error,
2789                                    BlockdevOnError on_target_error,
2790                                    bool has_unmap, bool unmap,
2791                                    const char *filter_node_name,
2792                                    bool has_copy_mode, MirrorCopyMode copy_mode,
2793                                    bool has_auto_finalize, bool auto_finalize,
2794                                    bool has_auto_dismiss, bool auto_dismiss,
2795                                    Error **errp)
2796 {
2797     BlockDriverState *unfiltered_bs;
2798     int job_flags = JOB_DEFAULT;
2799 
2800     GLOBAL_STATE_CODE();
2801     GRAPH_RDLOCK_GUARD_MAINLOOP();
2802 
2803     if (!has_speed) {
2804         speed = 0;
2805     }
2806     if (!has_on_source_error) {
2807         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2808     }
2809     if (!has_on_target_error) {
2810         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2811     }
2812     if (!has_granularity) {
2813         granularity = 0;
2814     }
2815     if (!has_buf_size) {
2816         buf_size = 0;
2817     }
2818     if (!has_unmap) {
2819         unmap = true;
2820     }
2821     if (!has_copy_mode) {
2822         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
2823     }
2824     if (has_auto_finalize && !auto_finalize) {
2825         job_flags |= JOB_MANUAL_FINALIZE;
2826     }
2827     if (has_auto_dismiss && !auto_dismiss) {
2828         job_flags |= JOB_MANUAL_DISMISS;
2829     }
2830 
2831     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
2832         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2833                    "a value in range [512B, 64MB]");
2834         return;
2835     }
2836     if (granularity & (granularity - 1)) {
2837         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2838                    "a power of 2");
2839         return;
2840     }
2841 
2842     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2843         return;
2844     }
2845     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
2846         return;
2847     }
2848 
2849     if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) {
2850         sync = MIRROR_SYNC_MODE_FULL;
2851     }
2852 
2853     if (!replaces) {
2854         /* We want to mirror from @bs, but keep implicit filters on top */
2855         unfiltered_bs = bdrv_skip_implicit_filters(bs);
2856         if (unfiltered_bs != bs) {
2857             replaces = unfiltered_bs->node_name;
2858         }
2859     }
2860 
2861     if (replaces) {
2862         BlockDriverState *to_replace_bs;
2863         int64_t bs_size, replace_size;
2864 
2865         bs_size = bdrv_getlength(bs);
2866         if (bs_size < 0) {
2867             error_setg_errno(errp, -bs_size, "Failed to query device's size");
2868             return;
2869         }
2870 
2871         to_replace_bs = check_to_replace_node(bs, replaces, errp);
2872         if (!to_replace_bs) {
2873             return;
2874         }
2875 
2876         replace_size = bdrv_getlength(to_replace_bs);
2877 
2878         if (replace_size < 0) {
2879             error_setg_errno(errp, -replace_size,
2880                              "Failed to query the replacement node's size");
2881             return;
2882         }
2883         if (bs_size != replace_size) {
2884             error_setg(errp, "cannot replace image with a mirror image of "
2885                              "different size");
2886             return;
2887         }
2888     }
2889 
2890     /* pass the node name to replace to mirror start since it's loose coupling
2891      * and will allow to check whether the node still exist at mirror completion
2892      */
2893     mirror_start(job_id, bs, target,
2894                  replaces, job_flags,
2895                  speed, granularity, buf_size, sync, backing_mode, zero_target,
2896                  on_source_error, on_target_error, unmap, filter_node_name,
2897                  copy_mode, errp);
2898 }
2899 
2900 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
2901 {
2902     BlockDriverState *bs;
2903     BlockDriverState *target_backing_bs, *target_bs;
2904     AioContext *aio_context;
2905     BlockMirrorBackingMode backing_mode;
2906     Error *local_err = NULL;
2907     QDict *options = NULL;
2908     int flags;
2909     int64_t size;
2910     const char *format = arg->format;
2911     bool zero_target;
2912     int ret;
2913 
2914     bs = qmp_get_root_bs(arg->device, errp);
2915     if (!bs) {
2916         return;
2917     }
2918 
2919     /* Early check to avoid creating target */
2920     bdrv_graph_rdlock_main_loop();
2921     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2922         bdrv_graph_rdunlock_main_loop();
2923         return;
2924     }
2925 
2926     aio_context = bdrv_get_aio_context(bs);
2927 
2928     if (!arg->has_mode) {
2929         arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
2930     }
2931 
2932     if (!arg->format) {
2933         format = (arg->mode == NEW_IMAGE_MODE_EXISTING
2934                   ? NULL : bs->drv->format_name);
2935     }
2936 
2937     flags = bs->open_flags | BDRV_O_RDWR;
2938     target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs));
2939     if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) {
2940         arg->sync = MIRROR_SYNC_MODE_FULL;
2941     }
2942     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
2943         target_backing_bs = bs;
2944     }
2945     bdrv_graph_rdunlock_main_loop();
2946 
2947     size = bdrv_getlength(bs);
2948     if (size < 0) {
2949         error_setg_errno(errp, -size, "bdrv_getlength failed");
2950         return;
2951     }
2952 
2953     if (arg->replaces) {
2954         if (!arg->node_name) {
2955             error_setg(errp, "a node-name must be provided when replacing a"
2956                              " named node of the graph");
2957             return;
2958         }
2959     }
2960 
2961     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
2962         backing_mode = MIRROR_SOURCE_BACKING_CHAIN;
2963     } else {
2964         backing_mode = MIRROR_OPEN_BACKING_CHAIN;
2965     }
2966 
2967     /* Don't open backing image in create() */
2968     flags |= BDRV_O_NO_BACKING;
2969 
2970     if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs)
2971         && arg->mode != NEW_IMAGE_MODE_EXISTING)
2972     {
2973         /* create new image w/o backing file */
2974         assert(format);
2975         bdrv_img_create(arg->target, format,
2976                         NULL, NULL, NULL, size, flags, false, &local_err);
2977     } else {
2978         BlockDriverState *explicit_backing;
2979 
2980         switch (arg->mode) {
2981         case NEW_IMAGE_MODE_EXISTING:
2982             break;
2983         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
2984             /*
2985              * Create new image with backing file.
2986              * Implicit filters should not appear in the filename.
2987              */
2988             bdrv_graph_rdlock_main_loop();
2989             explicit_backing = bdrv_skip_implicit_filters(target_backing_bs);
2990             bdrv_refresh_filename(explicit_backing);
2991             bdrv_graph_rdunlock_main_loop();
2992 
2993             bdrv_img_create(arg->target, format,
2994                             explicit_backing->filename,
2995                             explicit_backing->drv->format_name,
2996                             NULL, size, flags, false, &local_err);
2997             break;
2998         default:
2999             abort();
3000         }
3001     }
3002 
3003     if (local_err) {
3004         error_propagate(errp, local_err);
3005         return;
3006     }
3007 
3008     options = qdict_new();
3009     if (arg->node_name) {
3010         qdict_put_str(options, "node-name", arg->node_name);
3011     }
3012     if (format) {
3013         qdict_put_str(options, "driver", format);
3014     }
3015 
3016     /* Mirroring takes care of copy-on-write using the source's backing
3017      * file.
3018      */
3019     target_bs = bdrv_open(arg->target, NULL, options, flags, errp);
3020     if (!target_bs) {
3021         return;
3022     }
3023 
3024     bdrv_graph_rdlock_main_loop();
3025     zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
3026                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||
3027                     !bdrv_has_zero_init(target_bs)));
3028     bdrv_graph_rdunlock_main_loop();
3029 
3030 
3031     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3032     if (ret < 0) {
3033         bdrv_unref(target_bs);
3034         return;
3035     }
3036 
3037     blockdev_mirror_common(arg->job_id, bs, target_bs,
3038                            arg->replaces, arg->sync,
3039                            backing_mode, zero_target,
3040                            arg->has_speed, arg->speed,
3041                            arg->has_granularity, arg->granularity,
3042                            arg->has_buf_size, arg->buf_size,
3043                            arg->has_on_source_error, arg->on_source_error,
3044                            arg->has_on_target_error, arg->on_target_error,
3045                            arg->has_unmap, arg->unmap,
3046                            NULL,
3047                            arg->has_copy_mode, arg->copy_mode,
3048                            arg->has_auto_finalize, arg->auto_finalize,
3049                            arg->has_auto_dismiss, arg->auto_dismiss,
3050                            errp);
3051     bdrv_unref(target_bs);
3052 }
3053 
3054 void qmp_blockdev_mirror(const char *job_id,
3055                          const char *device, const char *target,
3056                          const char *replaces,
3057                          MirrorSyncMode sync,
3058                          bool has_speed, int64_t speed,
3059                          bool has_granularity, uint32_t granularity,
3060                          bool has_buf_size, int64_t buf_size,
3061                          bool has_on_source_error,
3062                          BlockdevOnError on_source_error,
3063                          bool has_on_target_error,
3064                          BlockdevOnError on_target_error,
3065                          const char *filter_node_name,
3066                          bool has_copy_mode, MirrorCopyMode copy_mode,
3067                          bool has_auto_finalize, bool auto_finalize,
3068                          bool has_auto_dismiss, bool auto_dismiss,
3069                          Error **errp)
3070 {
3071     BlockDriverState *bs;
3072     BlockDriverState *target_bs;
3073     AioContext *aio_context;
3074     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;
3075     bool zero_target;
3076     int ret;
3077 
3078     bs = qmp_get_root_bs(device, errp);
3079     if (!bs) {
3080         return;
3081     }
3082 
3083     target_bs = bdrv_lookup_bs(target, target, errp);
3084     if (!target_bs) {
3085         return;
3086     }
3087 
3088     zero_target = (sync == MIRROR_SYNC_MODE_FULL);
3089 
3090     aio_context = bdrv_get_aio_context(bs);
3091 
3092     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3093     if (ret < 0) {
3094         return;
3095     }
3096 
3097     blockdev_mirror_common(job_id, bs, target_bs,
3098                            replaces, sync, backing_mode,
3099                            zero_target, has_speed, speed,
3100                            has_granularity, granularity,
3101                            has_buf_size, buf_size,
3102                            has_on_source_error, on_source_error,
3103                            has_on_target_error, on_target_error,
3104                            true, true, filter_node_name,
3105                            has_copy_mode, copy_mode,
3106                            has_auto_finalize, auto_finalize,
3107                            has_auto_dismiss, auto_dismiss,
3108                            errp);
3109 }
3110 
3111 /*
3112  * Get a block job using its ID. Called with job_mutex held.
3113  */
3114 static BlockJob *find_block_job_locked(const char *id, Error **errp)
3115 {
3116     BlockJob *job;
3117 
3118     assert(id != NULL);
3119 
3120     job = block_job_get_locked(id);
3121 
3122     if (!job) {
3123         error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
3124                   "Block job '%s' not found", id);
3125         return NULL;
3126     }
3127 
3128     return job;
3129 }
3130 
3131 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
3132 {
3133     BlockJob *job;
3134 
3135     JOB_LOCK_GUARD();
3136     job = find_block_job_locked(device, errp);
3137 
3138     if (!job) {
3139         return;
3140     }
3141 
3142     block_job_set_speed_locked(job, speed, errp);
3143 }
3144 
3145 void qmp_block_job_cancel(const char *device,
3146                           bool has_force, bool force, Error **errp)
3147 {
3148     BlockJob *job;
3149 
3150     JOB_LOCK_GUARD();
3151     job = find_block_job_locked(device, errp);
3152 
3153     if (!job) {
3154         return;
3155     }
3156 
3157     if (!has_force) {
3158         force = false;
3159     }
3160 
3161     if (job_user_paused_locked(&job->job) && !force) {
3162         error_setg(errp, "The block job for device '%s' is currently paused",
3163                    device);
3164         return;
3165     }
3166 
3167     trace_qmp_block_job_cancel(job);
3168     job_user_cancel_locked(&job->job, force, errp);
3169 }
3170 
3171 void qmp_block_job_pause(const char *device, Error **errp)
3172 {
3173     BlockJob *job;
3174 
3175     JOB_LOCK_GUARD();
3176     job = find_block_job_locked(device, errp);
3177 
3178     if (!job) {
3179         return;
3180     }
3181 
3182     trace_qmp_block_job_pause(job);
3183     job_user_pause_locked(&job->job, errp);
3184 }
3185 
3186 void qmp_block_job_resume(const char *device, Error **errp)
3187 {
3188     BlockJob *job;
3189 
3190     JOB_LOCK_GUARD();
3191     job = find_block_job_locked(device, errp);
3192 
3193     if (!job) {
3194         return;
3195     }
3196 
3197     trace_qmp_block_job_resume(job);
3198     job_user_resume_locked(&job->job, errp);
3199 }
3200 
3201 void qmp_block_job_complete(const char *device, Error **errp)
3202 {
3203     BlockJob *job;
3204 
3205     JOB_LOCK_GUARD();
3206     job = find_block_job_locked(device, errp);
3207 
3208     if (!job) {
3209         return;
3210     }
3211 
3212     trace_qmp_block_job_complete(job);
3213     job_complete_locked(&job->job, errp);
3214 }
3215 
3216 void qmp_block_job_finalize(const char *id, Error **errp)
3217 {
3218     BlockJob *job;
3219 
3220     JOB_LOCK_GUARD();
3221     job = find_block_job_locked(id, errp);
3222 
3223     if (!job) {
3224         return;
3225     }
3226 
3227     trace_qmp_block_job_finalize(job);
3228     job_ref_locked(&job->job);
3229     job_finalize_locked(&job->job, errp);
3230 
3231     job_unref_locked(&job->job);
3232 }
3233 
3234 void qmp_block_job_dismiss(const char *id, Error **errp)
3235 {
3236     BlockJob *bjob;
3237     Job *job;
3238 
3239     JOB_LOCK_GUARD();
3240     bjob = find_block_job_locked(id, errp);
3241 
3242     if (!bjob) {
3243         return;
3244     }
3245 
3246     trace_qmp_block_job_dismiss(bjob);
3247     job = &bjob->job;
3248     job_dismiss_locked(&job, errp);
3249 }
3250 
3251 void qmp_block_job_change(BlockJobChangeOptions *opts, Error **errp)
3252 {
3253     BlockJob *job;
3254 
3255     JOB_LOCK_GUARD();
3256     job = find_block_job_locked(opts->id, errp);
3257 
3258     if (!job) {
3259         return;
3260     }
3261 
3262     block_job_change_locked(job, opts, errp);
3263 }
3264 
3265 void qmp_change_backing_file(const char *device,
3266                              const char *image_node_name,
3267                              const char *backing_file,
3268                              Error **errp)
3269 {
3270     BlockDriverState *bs = NULL;
3271     BlockDriverState *image_bs = NULL;
3272     Error *local_err = NULL;
3273     bool ro;
3274     int ret;
3275 
3276     bs = qmp_get_root_bs(device, errp);
3277     if (!bs) {
3278         return;
3279     }
3280 
3281     bdrv_graph_rdlock_main_loop();
3282 
3283     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
3284     if (local_err) {
3285         error_propagate(errp, local_err);
3286         goto out_rdlock;
3287     }
3288 
3289     if (!image_bs) {
3290         error_setg(errp, "image file not found");
3291         goto out_rdlock;
3292     }
3293 
3294     if (bdrv_find_base(image_bs) == image_bs) {
3295         error_setg(errp, "not allowing backing file change on an image "
3296                          "without a backing file");
3297         goto out_rdlock;
3298     }
3299 
3300     /* even though we are not necessarily operating on bs, we need it to
3301      * determine if block ops are currently prohibited on the chain */
3302     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
3303         goto out_rdlock;
3304     }
3305 
3306     /* final sanity check */
3307     if (!bdrv_chain_contains(bs, image_bs)) {
3308         error_setg(errp, "'%s' and image file are not in the same chain",
3309                    device);
3310         goto out_rdlock;
3311     }
3312     bdrv_graph_rdunlock_main_loop();
3313 
3314     /* if not r/w, reopen to make r/w */
3315     ro = bdrv_is_read_only(image_bs);
3316 
3317     if (ro) {
3318         if (bdrv_reopen_set_read_only(image_bs, false, errp) != 0) {
3319             return;
3320         }
3321     }
3322 
3323     ret = bdrv_change_backing_file(image_bs, backing_file,
3324                                    image_bs->drv ? image_bs->drv->format_name : "",
3325                                    false);
3326 
3327     if (ret < 0) {
3328         error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
3329                          backing_file);
3330         /* don't exit here, so we can try to restore open flags if
3331          * appropriate */
3332     }
3333 
3334     if (ro) {
3335         bdrv_reopen_set_read_only(image_bs, true, errp);
3336     }
3337     return;
3338 
3339 out_rdlock:
3340     bdrv_graph_rdunlock_main_loop();
3341 }
3342 
3343 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
3344 {
3345     BlockDriverState *bs;
3346     QObject *obj;
3347     Visitor *v = qobject_output_visitor_new(&obj);
3348     QDict *qdict;
3349 
3350     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3351     visit_complete(v, &obj);
3352     qdict = qobject_to(QDict, obj);
3353 
3354     qdict_flatten(qdict);
3355 
3356     if (!qdict_get_try_str(qdict, "node-name")) {
3357         error_setg(errp, "'node-name' must be specified for the root node");
3358         goto fail;
3359     }
3360 
3361     bs = bds_tree_init(qdict, errp);
3362     if (!bs) {
3363         goto fail;
3364     }
3365 
3366     bdrv_set_monitor_owned(bs);
3367 
3368 fail:
3369     visit_free(v);
3370 }
3371 
3372 void qmp_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
3373 {
3374     BlockReopenQueue *queue = NULL;
3375 
3376     /* Add each one of the BDS that we want to reopen to the queue */
3377     for (; reopen_list != NULL; reopen_list = reopen_list->next) {
3378         BlockdevOptions *options = reopen_list->value;
3379         BlockDriverState *bs;
3380         QObject *obj;
3381         Visitor *v;
3382         QDict *qdict;
3383 
3384         /* Check for the selected node name */
3385         if (!options->node_name) {
3386             error_setg(errp, "node-name not specified");
3387             goto fail;
3388         }
3389 
3390         bs = bdrv_find_node(options->node_name);
3391         if (!bs) {
3392             error_setg(errp, "Failed to find node with node-name='%s'",
3393                        options->node_name);
3394             goto fail;
3395         }
3396 
3397         /* Put all options in a QDict and flatten it */
3398         v = qobject_output_visitor_new(&obj);
3399         visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3400         visit_complete(v, &obj);
3401         visit_free(v);
3402 
3403         qdict = qobject_to(QDict, obj);
3404 
3405         qdict_flatten(qdict);
3406 
3407         queue = bdrv_reopen_queue(queue, bs, qdict, false);
3408     }
3409 
3410     /* Perform the reopen operation */
3411     bdrv_reopen_multiple(queue, errp);
3412     queue = NULL;
3413 
3414 fail:
3415     bdrv_reopen_queue_free(queue);
3416 }
3417 
3418 void qmp_blockdev_del(const char *node_name, Error **errp)
3419 {
3420     BlockDriverState *bs;
3421 
3422     GLOBAL_STATE_CODE();
3423     GRAPH_RDLOCK_GUARD_MAINLOOP();
3424 
3425     bs = bdrv_find_node(node_name);
3426     if (!bs) {
3427         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3428         return;
3429     }
3430     if (bdrv_has_blk(bs)) {
3431         error_setg(errp, "Node %s is in use", node_name);
3432         return;
3433     }
3434 
3435     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
3436         return;
3437     }
3438 
3439     if (!QTAILQ_IN_USE(bs, monitor_list)) {
3440         error_setg(errp, "Node %s is not owned by the monitor",
3441                    bs->node_name);
3442         return;
3443     }
3444 
3445     if (bs->refcnt > 1) {
3446         error_setg(errp, "Block device %s is in use",
3447                    bdrv_get_device_or_node_name(bs));
3448         return;
3449     }
3450 
3451     QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
3452     bdrv_unref(bs);
3453 }
3454 
3455 static BdrvChild * GRAPH_RDLOCK
3456 bdrv_find_child(BlockDriverState *parent_bs, const char *child_name)
3457 {
3458     BdrvChild *child;
3459 
3460     QLIST_FOREACH(child, &parent_bs->children, next) {
3461         if (strcmp(child->name, child_name) == 0) {
3462             return child;
3463         }
3464     }
3465 
3466     return NULL;
3467 }
3468 
3469 void qmp_x_blockdev_change(const char *parent, const char *child,
3470                            const char *node, Error **errp)
3471 {
3472     BlockDriverState *parent_bs, *new_bs = NULL;
3473     BdrvChild *p_child;
3474 
3475     bdrv_graph_wrlock();
3476 
3477     parent_bs = bdrv_lookup_bs(parent, parent, errp);
3478     if (!parent_bs) {
3479         goto out;
3480     }
3481 
3482     if (!child == !node) {
3483         if (child) {
3484             error_setg(errp, "The parameters child and node are in conflict");
3485         } else {
3486             error_setg(errp, "Either child or node must be specified");
3487         }
3488         goto out;
3489     }
3490 
3491     if (child) {
3492         p_child = bdrv_find_child(parent_bs, child);
3493         if (!p_child) {
3494             error_setg(errp, "Node '%s' does not have child '%s'",
3495                        parent, child);
3496             goto out;
3497         }
3498         bdrv_del_child(parent_bs, p_child, errp);
3499     }
3500 
3501     if (node) {
3502         new_bs = bdrv_find_node(node);
3503         if (!new_bs) {
3504             error_setg(errp, "Node '%s' not found", node);
3505             goto out;
3506         }
3507         bdrv_add_child(parent_bs, new_bs, errp);
3508     }
3509 
3510 out:
3511     bdrv_graph_wrunlock();
3512 }
3513 
3514 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
3515 {
3516     BlockJobInfoList *head = NULL, **tail = &head;
3517     BlockJob *job;
3518 
3519     JOB_LOCK_GUARD();
3520 
3521     for (job = block_job_next_locked(NULL); job;
3522          job = block_job_next_locked(job)) {
3523         BlockJobInfo *value;
3524 
3525         if (block_job_is_internal(job)) {
3526             continue;
3527         }
3528         value = block_job_query_locked(job, errp);
3529         if (!value) {
3530             qapi_free_BlockJobInfoList(head);
3531             return NULL;
3532         }
3533         QAPI_LIST_APPEND(tail, value);
3534     }
3535 
3536     return head;
3537 }
3538 
3539 void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
3540                                  bool has_force, bool force, Error **errp)
3541 {
3542     AioContext *new_context;
3543     BlockDriverState *bs;
3544 
3545     GRAPH_RDLOCK_GUARD_MAINLOOP();
3546 
3547     bs = bdrv_find_node(node_name);
3548     if (!bs) {
3549         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3550         return;
3551     }
3552 
3553     /* Protects against accidents. */
3554     if (!(has_force && force) && bdrv_has_blk(bs)) {
3555         error_setg(errp, "Node %s is associated with a BlockBackend and could "
3556                          "be in use (use force=true to override this check)",
3557                          node_name);
3558         return;
3559     }
3560 
3561     if (iothread->type == QTYPE_QSTRING) {
3562         IOThread *obj = iothread_by_id(iothread->u.s);
3563         if (!obj) {
3564             error_setg(errp, "Cannot find iothread %s", iothread->u.s);
3565             return;
3566         }
3567 
3568         new_context = iothread_get_aio_context(obj);
3569     } else {
3570         new_context = qemu_get_aio_context();
3571     }
3572 
3573     bdrv_try_change_aio_context(bs, new_context, NULL, errp);
3574 }
3575 
3576 QemuOptsList qemu_common_drive_opts = {
3577     .name = "drive",
3578     .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
3579     .desc = {
3580         {
3581             .name = "snapshot",
3582             .type = QEMU_OPT_BOOL,
3583             .help = "enable/disable snapshot mode",
3584         },{
3585             .name = "aio",
3586             .type = QEMU_OPT_STRING,
3587             .help = "host AIO implementation (threads, native, io_uring)",
3588         },{
3589             .name = BDRV_OPT_CACHE_WB,
3590             .type = QEMU_OPT_BOOL,
3591             .help = "Enable writeback mode",
3592         },{
3593             .name = "format",
3594             .type = QEMU_OPT_STRING,
3595             .help = "disk format (raw, qcow2, ...)",
3596         },{
3597             .name = "rerror",
3598             .type = QEMU_OPT_STRING,
3599             .help = "read error action",
3600         },{
3601             .name = "werror",
3602             .type = QEMU_OPT_STRING,
3603             .help = "write error action",
3604         },{
3605             .name = BDRV_OPT_READ_ONLY,
3606             .type = QEMU_OPT_BOOL,
3607             .help = "open drive file as read-only",
3608         },
3609 
3610         THROTTLE_OPTS,
3611 
3612         {
3613             .name = "throttling.group",
3614             .type = QEMU_OPT_STRING,
3615             .help = "name of the block throttling group",
3616         },{
3617             .name = "copy-on-read",
3618             .type = QEMU_OPT_BOOL,
3619             .help = "copy read data from backing file into image file",
3620         },{
3621             .name = "detect-zeroes",
3622             .type = QEMU_OPT_STRING,
3623             .help = "try to optimize zero writes (off, on, unmap)",
3624         },{
3625             .name = "stats-account-invalid",
3626             .type = QEMU_OPT_BOOL,
3627             .help = "whether to account for invalid I/O operations "
3628                     "in the statistics",
3629         },{
3630             .name = "stats-account-failed",
3631             .type = QEMU_OPT_BOOL,
3632             .help = "whether to account for failed I/O operations "
3633                     "in the statistics",
3634         },
3635         { /* end of list */ }
3636     },
3637 };
3638 
3639 QemuOptsList qemu_drive_opts = {
3640     .name = "drive",
3641     .head = QTAILQ_HEAD_INITIALIZER(qemu_drive_opts.head),
3642     .desc = {
3643         /*
3644          * no elements => accept any params
3645          * validation will happen later
3646          */
3647         { /* end of list */ }
3648     },
3649 };
3650