xref: /openbmc/qemu/blockdev.c (revision ccc5a4c5)
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, because it gets desugared into -device,
259          * 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_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             unsigned long long length;
345             const char *str = qstring_get_str(qobject_to(QString,
346                                                          entry->value));
347             if (parse_uint_full(str, &length, 10) == 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         AioContext *ctx = bdrv_get_aio_context(bs);
689 
690         aio_context_acquire(ctx);
691         bdrv_unref(bs);
692         aio_context_release(ctx);
693     }
694 }
695 
696 /* Iterates over the list of monitor-owned BlockDriverStates */
697 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs)
698 {
699     GLOBAL_STATE_CODE();
700     return bs ? QTAILQ_NEXT(bs, monitor_list)
701               : QTAILQ_FIRST(&monitor_bdrv_states);
702 }
703 
704 static bool qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
705                             Error **errp)
706 {
707     const char *value;
708 
709     value = qemu_opt_get(opts, from);
710     if (value) {
711         if (qemu_opt_find(opts, to)) {
712             error_setg(errp, "'%s' and its alias '%s' can't be used at the "
713                        "same time", to, from);
714             return false;
715         }
716     }
717 
718     /* rename all items in opts */
719     while ((value = qemu_opt_get(opts, from))) {
720         qemu_opt_set(opts, to, value, &error_abort);
721         qemu_opt_unset(opts, from);
722     }
723     return true;
724 }
725 
726 QemuOptsList qemu_legacy_drive_opts = {
727     .name = "drive",
728     .head = QTAILQ_HEAD_INITIALIZER(qemu_legacy_drive_opts.head),
729     .desc = {
730         {
731             .name = "bus",
732             .type = QEMU_OPT_NUMBER,
733             .help = "bus number",
734         },{
735             .name = "unit",
736             .type = QEMU_OPT_NUMBER,
737             .help = "unit number (i.e. lun for scsi)",
738         },{
739             .name = "index",
740             .type = QEMU_OPT_NUMBER,
741             .help = "index number",
742         },{
743             .name = "media",
744             .type = QEMU_OPT_STRING,
745             .help = "media type (disk, cdrom)",
746         },{
747             .name = "if",
748             .type = QEMU_OPT_STRING,
749             .help = "interface (ide, scsi, sd, mtd, floppy, pflash, virtio)",
750         },{
751             .name = "file",
752             .type = QEMU_OPT_STRING,
753             .help = "file name",
754         },
755 
756         /* Options that are passed on, but have special semantics with -drive */
757         {
758             .name = BDRV_OPT_READ_ONLY,
759             .type = QEMU_OPT_BOOL,
760             .help = "open drive file as read-only",
761         },{
762             .name = "rerror",
763             .type = QEMU_OPT_STRING,
764             .help = "read error action",
765         },{
766             .name = "werror",
767             .type = QEMU_OPT_STRING,
768             .help = "write error action",
769         },{
770             .name = "copy-on-read",
771             .type = QEMU_OPT_BOOL,
772             .help = "copy read data from backing file into image file",
773         },
774 
775         { /* end of list */ }
776     },
777 };
778 
779 DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type,
780                      Error **errp)
781 {
782     const char *value;
783     BlockBackend *blk;
784     DriveInfo *dinfo = NULL;
785     QDict *bs_opts;
786     QemuOpts *legacy_opts;
787     DriveMediaType media = MEDIA_DISK;
788     BlockInterfaceType type;
789     int max_devs, bus_id, unit_id, index;
790     const char *werror, *rerror;
791     bool read_only = false;
792     bool copy_on_read;
793     const char *filename;
794     int i;
795 
796     GLOBAL_STATE_CODE();
797 
798     /* Change legacy command line options into QMP ones */
799     static const struct {
800         const char *from;
801         const char *to;
802     } opt_renames[] = {
803         { "iops",           "throttling.iops-total" },
804         { "iops_rd",        "throttling.iops-read" },
805         { "iops_wr",        "throttling.iops-write" },
806 
807         { "bps",            "throttling.bps-total" },
808         { "bps_rd",         "throttling.bps-read" },
809         { "bps_wr",         "throttling.bps-write" },
810 
811         { "iops_max",       "throttling.iops-total-max" },
812         { "iops_rd_max",    "throttling.iops-read-max" },
813         { "iops_wr_max",    "throttling.iops-write-max" },
814 
815         { "bps_max",        "throttling.bps-total-max" },
816         { "bps_rd_max",     "throttling.bps-read-max" },
817         { "bps_wr_max",     "throttling.bps-write-max" },
818 
819         { "iops_size",      "throttling.iops-size" },
820 
821         { "group",          "throttling.group" },
822 
823         { "readonly",       BDRV_OPT_READ_ONLY },
824     };
825 
826     for (i = 0; i < ARRAY_SIZE(opt_renames); i++) {
827         if (!qemu_opt_rename(all_opts, opt_renames[i].from,
828                              opt_renames[i].to, errp)) {
829             return NULL;
830         }
831     }
832 
833     value = qemu_opt_get(all_opts, "cache");
834     if (value) {
835         int flags = 0;
836         bool writethrough;
837 
838         if (bdrv_parse_cache_mode(value, &flags, &writethrough) != 0) {
839             error_setg(errp, "invalid cache option");
840             return NULL;
841         }
842 
843         /* Specific options take precedence */
844         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_WB)) {
845             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_WB,
846                               !writethrough, &error_abort);
847         }
848         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_DIRECT)) {
849             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_DIRECT,
850                               !!(flags & BDRV_O_NOCACHE), &error_abort);
851         }
852         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_NO_FLUSH)) {
853             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_NO_FLUSH,
854                               !!(flags & BDRV_O_NO_FLUSH), &error_abort);
855         }
856         qemu_opt_unset(all_opts, "cache");
857     }
858 
859     /* Get a QDict for processing the options */
860     bs_opts = qdict_new();
861     qemu_opts_to_qdict(all_opts, bs_opts);
862 
863     legacy_opts = qemu_opts_create(&qemu_legacy_drive_opts, NULL, 0,
864                                    &error_abort);
865     if (!qemu_opts_absorb_qdict(legacy_opts, bs_opts, errp)) {
866         goto fail;
867     }
868 
869     /* Media type */
870     value = qemu_opt_get(legacy_opts, "media");
871     if (value) {
872         if (!strcmp(value, "disk")) {
873             media = MEDIA_DISK;
874         } else if (!strcmp(value, "cdrom")) {
875             media = MEDIA_CDROM;
876             read_only = true;
877         } else {
878             error_setg(errp, "'%s' invalid media", value);
879             goto fail;
880         }
881     }
882 
883     /* copy-on-read is disabled with a warning for read-only devices */
884     read_only |= qemu_opt_get_bool(legacy_opts, BDRV_OPT_READ_ONLY, false);
885     copy_on_read = qemu_opt_get_bool(legacy_opts, "copy-on-read", false);
886 
887     if (read_only && copy_on_read) {
888         warn_report("disabling copy-on-read on read-only drive");
889         copy_on_read = false;
890     }
891 
892     qdict_put_str(bs_opts, BDRV_OPT_READ_ONLY, read_only ? "on" : "off");
893     qdict_put_str(bs_opts, "copy-on-read", copy_on_read ? "on" : "off");
894 
895     /* Controller type */
896     value = qemu_opt_get(legacy_opts, "if");
897     if (value) {
898         for (type = 0;
899              type < IF_COUNT && strcmp(value, if_name[type]);
900              type++) {
901         }
902         if (type == IF_COUNT) {
903             error_setg(errp, "unsupported bus type '%s'", value);
904             goto fail;
905         }
906     } else {
907         type = block_default_type;
908     }
909 
910     /* Device address specified by bus/unit or index.
911      * If none was specified, try to find the first free one. */
912     bus_id  = qemu_opt_get_number(legacy_opts, "bus", 0);
913     unit_id = qemu_opt_get_number(legacy_opts, "unit", -1);
914     index   = qemu_opt_get_number(legacy_opts, "index", -1);
915 
916     max_devs = if_max_devs[type];
917 
918     if (index != -1) {
919         if (bus_id != 0 || unit_id != -1) {
920             error_setg(errp, "index cannot be used with bus and unit");
921             goto fail;
922         }
923         bus_id = drive_index_to_bus_id(type, index);
924         unit_id = drive_index_to_unit_id(type, index);
925     }
926 
927     if (unit_id == -1) {
928        unit_id = 0;
929        while (drive_get(type, bus_id, unit_id) != NULL) {
930            unit_id++;
931            if (max_devs && unit_id >= max_devs) {
932                unit_id -= max_devs;
933                bus_id++;
934            }
935        }
936     }
937 
938     if (max_devs && unit_id >= max_devs) {
939         error_setg(errp, "unit %d too big (max is %d)", unit_id, max_devs - 1);
940         goto fail;
941     }
942 
943     if (drive_get(type, bus_id, unit_id) != NULL) {
944         error_setg(errp, "drive with bus=%d, unit=%d (index=%d) exists",
945                    bus_id, unit_id, index);
946         goto fail;
947     }
948 
949     /* no id supplied -> create one */
950     if (qemu_opts_id(all_opts) == NULL) {
951         char *new_id;
952         const char *mediastr = "";
953         if (type == IF_IDE || type == IF_SCSI) {
954             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
955         }
956         if (max_devs) {
957             new_id = g_strdup_printf("%s%i%s%i", if_name[type], bus_id,
958                                      mediastr, unit_id);
959         } else {
960             new_id = g_strdup_printf("%s%s%i", if_name[type],
961                                      mediastr, unit_id);
962         }
963         qdict_put_str(bs_opts, "id", new_id);
964         g_free(new_id);
965     }
966 
967     /* Add virtio block device */
968     if (type == IF_VIRTIO) {
969         QemuOpts *devopts;
970         devopts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
971                                    &error_abort);
972         qemu_opt_set(devopts, "driver", "virtio-blk", &error_abort);
973         qemu_opt_set(devopts, "drive", qdict_get_str(bs_opts, "id"),
974                      &error_abort);
975     }
976 
977     filename = qemu_opt_get(legacy_opts, "file");
978 
979     /* Check werror/rerror compatibility with if=... */
980     werror = qemu_opt_get(legacy_opts, "werror");
981     if (werror != NULL) {
982         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO &&
983             type != IF_NONE) {
984             error_setg(errp, "werror is not supported by this bus type");
985             goto fail;
986         }
987         qdict_put_str(bs_opts, "werror", werror);
988     }
989 
990     rerror = qemu_opt_get(legacy_opts, "rerror");
991     if (rerror != NULL) {
992         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI &&
993             type != IF_NONE) {
994             error_setg(errp, "rerror is not supported by this bus type");
995             goto fail;
996         }
997         qdict_put_str(bs_opts, "rerror", rerror);
998     }
999 
1000     /* Actual block device init: Functionality shared with blockdev-add */
1001     blk = blockdev_init(filename, bs_opts, errp);
1002     bs_opts = NULL;
1003     if (!blk) {
1004         goto fail;
1005     }
1006 
1007     /* Create legacy DriveInfo */
1008     dinfo = g_malloc0(sizeof(*dinfo));
1009     dinfo->opts = all_opts;
1010 
1011     dinfo->type = type;
1012     dinfo->bus = bus_id;
1013     dinfo->unit = unit_id;
1014 
1015     blk_set_legacy_dinfo(blk, dinfo);
1016 
1017     switch(type) {
1018     case IF_IDE:
1019     case IF_SCSI:
1020     case IF_XEN:
1021     case IF_NONE:
1022         dinfo->media_cd = media == MEDIA_CDROM;
1023         break;
1024     default:
1025         break;
1026     }
1027 
1028 fail:
1029     qemu_opts_del(legacy_opts);
1030     qobject_unref(bs_opts);
1031     return dinfo;
1032 }
1033 
1034 static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
1035 {
1036     BlockDriverState *bs;
1037     AioContext *aio_context;
1038 
1039     bs = bdrv_lookup_bs(name, name, errp);
1040     if (bs == NULL) {
1041         return NULL;
1042     }
1043 
1044     if (!bdrv_is_root_node(bs)) {
1045         error_setg(errp, "Need a root block node");
1046         return NULL;
1047     }
1048 
1049     aio_context = bdrv_get_aio_context(bs);
1050     aio_context_acquire(aio_context);
1051 
1052     if (!bdrv_is_inserted(bs)) {
1053         error_setg(errp, "Device has no medium");
1054         bs = NULL;
1055     }
1056 
1057     aio_context_release(aio_context);
1058 
1059     return bs;
1060 }
1061 
1062 static void blockdev_do_action(TransactionAction *action, Error **errp)
1063 {
1064     TransactionActionList list;
1065 
1066     list.value = action;
1067     list.next = NULL;
1068     qmp_transaction(&list, NULL, errp);
1069 }
1070 
1071 void qmp_blockdev_snapshot_sync(const char *device, const char *node_name,
1072                                 const char *snapshot_file,
1073                                 const char *snapshot_node_name,
1074                                 const char *format,
1075                                 bool has_mode, NewImageMode mode, Error **errp)
1076 {
1077     BlockdevSnapshotSync snapshot = {
1078         .device = (char *) device,
1079         .node_name = (char *) node_name,
1080         .snapshot_file = (char *) snapshot_file,
1081         .snapshot_node_name = (char *) snapshot_node_name,
1082         .format = (char *) format,
1083         .has_mode = has_mode,
1084         .mode = mode,
1085     };
1086     TransactionAction action = {
1087         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
1088         .u.blockdev_snapshot_sync.data = &snapshot,
1089     };
1090     blockdev_do_action(&action, errp);
1091 }
1092 
1093 void qmp_blockdev_snapshot(const char *node, const char *overlay,
1094                            Error **errp)
1095 {
1096     BlockdevSnapshot snapshot_data = {
1097         .node = (char *) node,
1098         .overlay = (char *) overlay
1099     };
1100     TransactionAction action = {
1101         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
1102         .u.blockdev_snapshot.data = &snapshot_data,
1103     };
1104     blockdev_do_action(&action, errp);
1105 }
1106 
1107 void qmp_blockdev_snapshot_internal_sync(const char *device,
1108                                          const char *name,
1109                                          Error **errp)
1110 {
1111     BlockdevSnapshotInternal snapshot = {
1112         .device = (char *) device,
1113         .name = (char *) name
1114     };
1115     TransactionAction action = {
1116         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
1117         .u.blockdev_snapshot_internal_sync.data = &snapshot,
1118     };
1119     blockdev_do_action(&action, errp);
1120 }
1121 
1122 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
1123                                                          const char *id,
1124                                                          const char *name,
1125                                                          Error **errp)
1126 {
1127     BlockDriverState *bs;
1128     AioContext *aio_context;
1129     QEMUSnapshotInfo sn;
1130     Error *local_err = NULL;
1131     SnapshotInfo *info = NULL;
1132     int ret;
1133 
1134     bs = qmp_get_root_bs(device, errp);
1135     if (!bs) {
1136         return NULL;
1137     }
1138     aio_context = bdrv_get_aio_context(bs);
1139     aio_context_acquire(aio_context);
1140 
1141     if (!id && !name) {
1142         error_setg(errp, "Name or id must be provided");
1143         goto out_aio_context;
1144     }
1145 
1146     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
1147         goto out_aio_context;
1148     }
1149 
1150     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
1151     if (local_err) {
1152         error_propagate(errp, local_err);
1153         goto out_aio_context;
1154     }
1155     if (!ret) {
1156         error_setg(errp,
1157                    "Snapshot with id '%s' and name '%s' does not exist on "
1158                    "device '%s'",
1159                    STR_OR_NULL(id), STR_OR_NULL(name), device);
1160         goto out_aio_context;
1161     }
1162 
1163     bdrv_snapshot_delete(bs, id, name, &local_err);
1164     if (local_err) {
1165         error_propagate(errp, local_err);
1166         goto out_aio_context;
1167     }
1168 
1169     aio_context_release(aio_context);
1170 
1171     info = g_new0(SnapshotInfo, 1);
1172     info->id = g_strdup(sn.id_str);
1173     info->name = g_strdup(sn.name);
1174     info->date_nsec = sn.date_nsec;
1175     info->date_sec = sn.date_sec;
1176     info->vm_state_size = sn.vm_state_size;
1177     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
1178     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
1179     if (sn.icount != -1ULL) {
1180         info->icount = sn.icount;
1181         info->has_icount = true;
1182     }
1183 
1184     return info;
1185 
1186 out_aio_context:
1187     aio_context_release(aio_context);
1188     return NULL;
1189 }
1190 
1191 /* internal snapshot private data */
1192 typedef struct InternalSnapshotState {
1193     BlockDriverState *bs;
1194     QEMUSnapshotInfo sn;
1195     bool created;
1196 } InternalSnapshotState;
1197 
1198 static void internal_snapshot_abort(void *opaque);
1199 static void internal_snapshot_clean(void *opaque);
1200 TransactionActionDrv internal_snapshot_drv = {
1201     .abort = internal_snapshot_abort,
1202     .clean = internal_snapshot_clean,
1203 };
1204 
1205 static void internal_snapshot_action(BlockdevSnapshotInternal *internal,
1206                                      Transaction *tran, Error **errp)
1207 {
1208     Error *local_err = NULL;
1209     const char *device;
1210     const char *name;
1211     BlockDriverState *bs;
1212     QEMUSnapshotInfo old_sn, *sn;
1213     bool ret;
1214     int64_t rt;
1215     InternalSnapshotState *state = g_new0(InternalSnapshotState, 1);
1216     AioContext *aio_context;
1217     int ret1;
1218 
1219     tran_add(tran, &internal_snapshot_drv, state);
1220 
1221     device = internal->device;
1222     name = internal->name;
1223 
1224     bs = qmp_get_root_bs(device, errp);
1225     if (!bs) {
1226         return;
1227     }
1228 
1229     aio_context = bdrv_get_aio_context(bs);
1230     aio_context_acquire(aio_context);
1231 
1232     state->bs = bs;
1233 
1234     /* Paired with .clean() */
1235     bdrv_drained_begin(bs);
1236 
1237     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
1238         goto out;
1239     }
1240 
1241     if (bdrv_is_read_only(bs)) {
1242         error_setg(errp, "Device '%s' is read only", device);
1243         goto out;
1244     }
1245 
1246     if (!bdrv_can_snapshot(bs)) {
1247         error_setg(errp, "Block format '%s' used by device '%s' "
1248                    "does not support internal snapshots",
1249                    bs->drv->format_name, device);
1250         goto out;
1251     }
1252 
1253     if (!strlen(name)) {
1254         error_setg(errp, "Name is empty");
1255         goto out;
1256     }
1257 
1258     /* check whether a snapshot with name exist */
1259     ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &old_sn,
1260                                             &local_err);
1261     if (local_err) {
1262         error_propagate(errp, local_err);
1263         goto out;
1264     } else if (ret) {
1265         error_setg(errp,
1266                    "Snapshot with name '%s' already exists on device '%s'",
1267                    name, device);
1268         goto out;
1269     }
1270 
1271     /* 3. take the snapshot */
1272     sn = &state->sn;
1273     pstrcpy(sn->name, sizeof(sn->name), name);
1274     rt = g_get_real_time();
1275     sn->date_sec = rt / G_USEC_PER_SEC;
1276     sn->date_nsec = (rt % G_USEC_PER_SEC) * 1000;
1277     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1278     if (replay_mode != REPLAY_MODE_NONE) {
1279         sn->icount = replay_get_current_icount();
1280     } else {
1281         sn->icount = -1ULL;
1282     }
1283 
1284     ret1 = bdrv_snapshot_create(bs, sn);
1285     if (ret1 < 0) {
1286         error_setg_errno(errp, -ret1,
1287                          "Failed to create snapshot '%s' on device '%s'",
1288                          name, device);
1289         goto out;
1290     }
1291 
1292     /* 4. succeed, mark a snapshot is created */
1293     state->created = true;
1294 
1295 out:
1296     aio_context_release(aio_context);
1297 }
1298 
1299 static void internal_snapshot_abort(void *opaque)
1300 {
1301     InternalSnapshotState *state = opaque;
1302     BlockDriverState *bs = state->bs;
1303     QEMUSnapshotInfo *sn = &state->sn;
1304     AioContext *aio_context;
1305     Error *local_error = NULL;
1306 
1307     if (!state->created) {
1308         return;
1309     }
1310 
1311     aio_context = bdrv_get_aio_context(state->bs);
1312     aio_context_acquire(aio_context);
1313 
1314     if (bdrv_snapshot_delete(bs, sn->id_str, sn->name, &local_error) < 0) {
1315         error_reportf_err(local_error,
1316                           "Failed to delete snapshot with id '%s' and "
1317                           "name '%s' on device '%s' in abort: ",
1318                           sn->id_str, sn->name,
1319                           bdrv_get_device_name(bs));
1320     }
1321 
1322     aio_context_release(aio_context);
1323 }
1324 
1325 static void internal_snapshot_clean(void *opaque)
1326 {
1327     g_autofree InternalSnapshotState *state = opaque;
1328     AioContext *aio_context;
1329 
1330     if (!state->bs) {
1331         return;
1332     }
1333 
1334     aio_context = bdrv_get_aio_context(state->bs);
1335     aio_context_acquire(aio_context);
1336 
1337     bdrv_drained_end(state->bs);
1338 
1339     aio_context_release(aio_context);
1340 }
1341 
1342 /* external snapshot private data */
1343 typedef struct ExternalSnapshotState {
1344     BlockDriverState *old_bs;
1345     BlockDriverState *new_bs;
1346     bool overlay_appended;
1347 } ExternalSnapshotState;
1348 
1349 static void external_snapshot_commit(void *opaque);
1350 static void external_snapshot_abort(void *opaque);
1351 static void external_snapshot_clean(void *opaque);
1352 TransactionActionDrv external_snapshot_drv = {
1353     .commit = external_snapshot_commit,
1354     .abort = external_snapshot_abort,
1355     .clean = external_snapshot_clean,
1356 };
1357 
1358 static void external_snapshot_action(TransactionAction *action,
1359                                      Transaction *tran, Error **errp)
1360 {
1361     int ret;
1362     int flags = 0;
1363     QDict *options = NULL;
1364     Error *local_err = NULL;
1365     /* Device and node name of the image to generate the snapshot from */
1366     const char *device;
1367     const char *node_name;
1368     /* Reference to the new image (for 'blockdev-snapshot') */
1369     const char *snapshot_ref;
1370     /* File name of the new image (for 'blockdev-snapshot-sync') */
1371     const char *new_image_file;
1372     ExternalSnapshotState *state = g_new0(ExternalSnapshotState, 1);
1373     AioContext *aio_context;
1374     uint64_t perm, shared;
1375 
1376     tran_add(tran, &external_snapshot_drv, state);
1377 
1378     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
1379      * purpose but a different set of parameters */
1380     switch (action->type) {
1381     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
1382         {
1383             BlockdevSnapshot *s = action->u.blockdev_snapshot.data;
1384             device = s->node;
1385             node_name = s->node;
1386             new_image_file = NULL;
1387             snapshot_ref = s->overlay;
1388         }
1389         break;
1390     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
1391         {
1392             BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1393             device = s->device;
1394             node_name = s->node_name;
1395             new_image_file = s->snapshot_file;
1396             snapshot_ref = NULL;
1397         }
1398         break;
1399     default:
1400         g_assert_not_reached();
1401     }
1402 
1403     /* start processing */
1404 
1405     state->old_bs = bdrv_lookup_bs(device, node_name, errp);
1406     if (!state->old_bs) {
1407         return;
1408     }
1409 
1410     aio_context = bdrv_get_aio_context(state->old_bs);
1411     aio_context_acquire(aio_context);
1412 
1413     /* Paired with .clean() */
1414     bdrv_drained_begin(state->old_bs);
1415 
1416     if (!bdrv_is_inserted(state->old_bs)) {
1417         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1418         goto out;
1419     }
1420 
1421     if (bdrv_op_is_blocked(state->old_bs,
1422                            BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
1423         goto out;
1424     }
1425 
1426     if (!bdrv_is_read_only(state->old_bs)) {
1427         if (bdrv_flush(state->old_bs)) {
1428             error_setg(errp, QERR_IO_ERROR);
1429             goto out;
1430         }
1431     }
1432 
1433     if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
1434         BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1435         const char *format = s->format ?: "qcow2";
1436         enum NewImageMode mode;
1437         const char *snapshot_node_name = s->snapshot_node_name;
1438 
1439         if (node_name && !snapshot_node_name) {
1440             error_setg(errp, "New overlay node-name missing");
1441             goto out;
1442         }
1443 
1444         if (snapshot_node_name &&
1445             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
1446             error_setg(errp, "New overlay node-name already in use");
1447             goto out;
1448         }
1449 
1450         flags = state->old_bs->open_flags;
1451         flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ);
1452         flags |= BDRV_O_NO_BACKING;
1453 
1454         /* create new image w/backing file */
1455         mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1456         if (mode != NEW_IMAGE_MODE_EXISTING) {
1457             int64_t size = bdrv_getlength(state->old_bs);
1458             if (size < 0) {
1459                 error_setg_errno(errp, -size, "bdrv_getlength failed");
1460                 goto out;
1461             }
1462             bdrv_refresh_filename(state->old_bs);
1463 
1464             aio_context_release(aio_context);
1465             bdrv_img_create(new_image_file, format,
1466                             state->old_bs->filename,
1467                             state->old_bs->drv->format_name,
1468                             NULL, size, flags, false, &local_err);
1469             aio_context_acquire(aio_context);
1470 
1471             if (local_err) {
1472                 error_propagate(errp, local_err);
1473                 goto out;
1474             }
1475         }
1476 
1477         options = qdict_new();
1478         if (snapshot_node_name) {
1479             qdict_put_str(options, "node-name", snapshot_node_name);
1480         }
1481         qdict_put_str(options, "driver", format);
1482     }
1483 
1484     state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags,
1485                               errp);
1486     /* We will manually add the backing_hd field to the bs later */
1487     if (!state->new_bs) {
1488         goto out;
1489     }
1490 
1491     /*
1492      * Allow attaching a backing file to an overlay that's already in use only
1493      * if the parents don't assume that they are already seeing a valid image.
1494      * (Specifically, allow it as a mirror target, which is write-only access.)
1495      */
1496     bdrv_get_cumulative_perm(state->new_bs, &perm, &shared);
1497     if (perm & BLK_PERM_CONSISTENT_READ) {
1498         error_setg(errp, "The overlay is already in use");
1499         goto out;
1500     }
1501 
1502     if (state->new_bs->drv->is_filter) {
1503         error_setg(errp, "Filters cannot be used as overlays");
1504         goto out;
1505     }
1506 
1507     if (bdrv_cow_child(state->new_bs)) {
1508         error_setg(errp, "The overlay already has a backing image");
1509         goto out;
1510     }
1511 
1512     if (!state->new_bs->drv->supports_backing) {
1513         error_setg(errp, "The overlay does not support backing images");
1514         goto out;
1515     }
1516 
1517     ret = bdrv_append(state->new_bs, state->old_bs, errp);
1518     if (ret < 0) {
1519         goto out;
1520     }
1521     state->overlay_appended = true;
1522 
1523 out:
1524     aio_context_release(aio_context);
1525 }
1526 
1527 static void external_snapshot_commit(void *opaque)
1528 {
1529     ExternalSnapshotState *state = opaque;
1530     AioContext *aio_context;
1531 
1532     aio_context = bdrv_get_aio_context(state->old_bs);
1533     aio_context_acquire(aio_context);
1534 
1535     /* We don't need (or want) to use the transactional
1536      * bdrv_reopen_multiple() across all the entries at once, because we
1537      * don't want to abort all of them if one of them fails the reopen */
1538     if (!qatomic_read(&state->old_bs->copy_on_read)) {
1539         bdrv_reopen_set_read_only(state->old_bs, true, NULL);
1540     }
1541 
1542     aio_context_release(aio_context);
1543 }
1544 
1545 static void external_snapshot_abort(void *opaque)
1546 {
1547     ExternalSnapshotState *state = opaque;
1548     if (state->new_bs) {
1549         if (state->overlay_appended) {
1550             AioContext *aio_context;
1551             AioContext *tmp_context;
1552             int ret;
1553 
1554             aio_context = bdrv_get_aio_context(state->old_bs);
1555             aio_context_acquire(aio_context);
1556 
1557             bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
1558                                           close state->old_bs; we need it */
1559             bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
1560 
1561             /*
1562              * The call to bdrv_set_backing_hd() above returns state->old_bs to
1563              * the main AioContext. As we're still going to be using it, return
1564              * it to the AioContext it was before.
1565              */
1566             tmp_context = bdrv_get_aio_context(state->old_bs);
1567             if (aio_context != tmp_context) {
1568                 aio_context_release(aio_context);
1569                 aio_context_acquire(tmp_context);
1570 
1571                 ret = bdrv_try_change_aio_context(state->old_bs,
1572                                                   aio_context, NULL, NULL);
1573                 assert(ret == 0);
1574 
1575                 aio_context_release(tmp_context);
1576                 aio_context_acquire(aio_context);
1577             }
1578 
1579             bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
1580             bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
1581 
1582             aio_context_release(aio_context);
1583         }
1584     }
1585 }
1586 
1587 static void external_snapshot_clean(void *opaque)
1588 {
1589     g_autofree ExternalSnapshotState *state = opaque;
1590     AioContext *aio_context;
1591 
1592     if (!state->old_bs) {
1593         return;
1594     }
1595 
1596     aio_context = bdrv_get_aio_context(state->old_bs);
1597     aio_context_acquire(aio_context);
1598 
1599     bdrv_drained_end(state->old_bs);
1600     bdrv_unref(state->new_bs);
1601 
1602     aio_context_release(aio_context);
1603 }
1604 
1605 typedef struct DriveBackupState {
1606     BlockDriverState *bs;
1607     BlockJob *job;
1608 } DriveBackupState;
1609 
1610 static BlockJob *do_backup_common(BackupCommon *backup,
1611                                   BlockDriverState *bs,
1612                                   BlockDriverState *target_bs,
1613                                   AioContext *aio_context,
1614                                   JobTxn *txn, Error **errp);
1615 
1616 static void drive_backup_commit(void *opaque);
1617 static void drive_backup_abort(void *opaque);
1618 static void drive_backup_clean(void *opaque);
1619 TransactionActionDrv drive_backup_drv = {
1620     .commit = drive_backup_commit,
1621     .abort = drive_backup_abort,
1622     .clean = drive_backup_clean,
1623 };
1624 
1625 static void drive_backup_action(DriveBackup *backup,
1626                                 JobTxn *block_job_txn,
1627                                 Transaction *tran, Error **errp)
1628 {
1629     DriveBackupState *state = g_new0(DriveBackupState, 1);
1630     BlockDriverState *bs;
1631     BlockDriverState *target_bs;
1632     BlockDriverState *source = NULL;
1633     AioContext *aio_context;
1634     AioContext *old_context;
1635     const char *format;
1636     QDict *options;
1637     Error *local_err = NULL;
1638     int flags;
1639     int64_t size;
1640     bool set_backing_hd = false;
1641     int ret;
1642 
1643     tran_add(tran, &drive_backup_drv, state);
1644 
1645     if (!backup->has_mode) {
1646         backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1647     }
1648 
1649     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1650     if (!bs) {
1651         return;
1652     }
1653 
1654     if (!bs->drv) {
1655         error_setg(errp, "Device has no medium");
1656         return;
1657     }
1658 
1659     aio_context = bdrv_get_aio_context(bs);
1660     aio_context_acquire(aio_context);
1661 
1662     state->bs = bs;
1663     /* Paired with .clean() */
1664     bdrv_drained_begin(bs);
1665 
1666     format = backup->format;
1667     if (!format && backup->mode != NEW_IMAGE_MODE_EXISTING) {
1668         format = bs->drv->format_name;
1669     }
1670 
1671     /* Early check to avoid creating target */
1672     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
1673         goto out;
1674     }
1675 
1676     flags = bs->open_flags | BDRV_O_RDWR;
1677 
1678     /*
1679      * See if we have a backing HD we can use to create our new image
1680      * on top of.
1681      */
1682     if (backup->sync == MIRROR_SYNC_MODE_TOP) {
1683         /*
1684          * Backup will not replace the source by the target, so none
1685          * of the filters skipped here will be removed (in contrast to
1686          * mirror).  Therefore, we can skip all of them when looking
1687          * for the first COW relationship.
1688          */
1689         source = bdrv_cow_bs(bdrv_skip_filters(bs));
1690         if (!source) {
1691             backup->sync = MIRROR_SYNC_MODE_FULL;
1692         }
1693     }
1694     if (backup->sync == MIRROR_SYNC_MODE_NONE) {
1695         source = bs;
1696         flags |= BDRV_O_NO_BACKING;
1697         set_backing_hd = true;
1698     }
1699 
1700     size = bdrv_getlength(bs);
1701     if (size < 0) {
1702         error_setg_errno(errp, -size, "bdrv_getlength failed");
1703         goto out;
1704     }
1705 
1706     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
1707         assert(format);
1708         if (source) {
1709             /* Implicit filters should not appear in the filename */
1710             BlockDriverState *explicit_backing =
1711                 bdrv_skip_implicit_filters(source);
1712 
1713             bdrv_refresh_filename(explicit_backing);
1714             bdrv_img_create(backup->target, format,
1715                             explicit_backing->filename,
1716                             explicit_backing->drv->format_name, NULL,
1717                             size, flags, false, &local_err);
1718         } else {
1719             bdrv_img_create(backup->target, format, NULL, NULL, NULL,
1720                             size, flags, false, &local_err);
1721         }
1722     }
1723 
1724     if (local_err) {
1725         error_propagate(errp, local_err);
1726         goto out;
1727     }
1728 
1729     options = qdict_new();
1730     qdict_put_str(options, "discard", "unmap");
1731     qdict_put_str(options, "detect-zeroes", "unmap");
1732     if (format) {
1733         qdict_put_str(options, "driver", format);
1734     }
1735 
1736     target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
1737     if (!target_bs) {
1738         goto out;
1739     }
1740 
1741     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1742     old_context = bdrv_get_aio_context(target_bs);
1743     aio_context_release(aio_context);
1744     aio_context_acquire(old_context);
1745 
1746     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1747     if (ret < 0) {
1748         bdrv_unref(target_bs);
1749         aio_context_release(old_context);
1750         return;
1751     }
1752 
1753     aio_context_release(old_context);
1754     aio_context_acquire(aio_context);
1755 
1756     if (set_backing_hd) {
1757         if (bdrv_set_backing_hd(target_bs, source, errp) < 0) {
1758             goto unref;
1759         }
1760     }
1761 
1762     state->job = do_backup_common(qapi_DriveBackup_base(backup),
1763                                   bs, target_bs, aio_context,
1764                                   block_job_txn, errp);
1765 
1766 unref:
1767     bdrv_unref(target_bs);
1768 out:
1769     aio_context_release(aio_context);
1770 }
1771 
1772 static void drive_backup_commit(void *opaque)
1773 {
1774     DriveBackupState *state = opaque;
1775     AioContext *aio_context;
1776 
1777     aio_context = bdrv_get_aio_context(state->bs);
1778     aio_context_acquire(aio_context);
1779 
1780     assert(state->job);
1781     job_start(&state->job->job);
1782 
1783     aio_context_release(aio_context);
1784 }
1785 
1786 static void drive_backup_abort(void *opaque)
1787 {
1788     DriveBackupState *state = opaque;
1789 
1790     if (state->job) {
1791         job_cancel_sync(&state->job->job, true);
1792     }
1793 }
1794 
1795 static void drive_backup_clean(void *opaque)
1796 {
1797     g_autofree DriveBackupState *state = opaque;
1798     AioContext *aio_context;
1799 
1800     if (!state->bs) {
1801         return;
1802     }
1803 
1804     aio_context = bdrv_get_aio_context(state->bs);
1805     aio_context_acquire(aio_context);
1806 
1807     bdrv_drained_end(state->bs);
1808 
1809     aio_context_release(aio_context);
1810 }
1811 
1812 typedef struct BlockdevBackupState {
1813     BlockDriverState *bs;
1814     BlockJob *job;
1815 } BlockdevBackupState;
1816 
1817 static void blockdev_backup_commit(void *opaque);
1818 static void blockdev_backup_abort(void *opaque);
1819 static void blockdev_backup_clean(void *opaque);
1820 TransactionActionDrv blockdev_backup_drv = {
1821     .commit = blockdev_backup_commit,
1822     .abort = blockdev_backup_abort,
1823     .clean = blockdev_backup_clean,
1824 };
1825 
1826 static void blockdev_backup_action(BlockdevBackup *backup,
1827                                    JobTxn *block_job_txn,
1828                                    Transaction *tran, Error **errp)
1829 {
1830     BlockdevBackupState *state = g_new0(BlockdevBackupState, 1);
1831     BlockDriverState *bs;
1832     BlockDriverState *target_bs;
1833     AioContext *aio_context;
1834     AioContext *old_context;
1835     int ret;
1836 
1837     tran_add(tran, &blockdev_backup_drv, state);
1838 
1839     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1840     if (!bs) {
1841         return;
1842     }
1843 
1844     target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);
1845     if (!target_bs) {
1846         return;
1847     }
1848 
1849     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1850     aio_context = bdrv_get_aio_context(bs);
1851     old_context = bdrv_get_aio_context(target_bs);
1852     aio_context_acquire(old_context);
1853 
1854     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1855     if (ret < 0) {
1856         aio_context_release(old_context);
1857         return;
1858     }
1859 
1860     aio_context_release(old_context);
1861     aio_context_acquire(aio_context);
1862     state->bs = bs;
1863 
1864     /* Paired with .clean() */
1865     bdrv_drained_begin(state->bs);
1866 
1867     state->job = do_backup_common(qapi_BlockdevBackup_base(backup),
1868                                   bs, target_bs, aio_context,
1869                                   block_job_txn, errp);
1870 
1871     aio_context_release(aio_context);
1872 }
1873 
1874 static void blockdev_backup_commit(void *opaque)
1875 {
1876     BlockdevBackupState *state = opaque;
1877     AioContext *aio_context;
1878 
1879     aio_context = bdrv_get_aio_context(state->bs);
1880     aio_context_acquire(aio_context);
1881 
1882     assert(state->job);
1883     job_start(&state->job->job);
1884 
1885     aio_context_release(aio_context);
1886 }
1887 
1888 static void blockdev_backup_abort(void *opaque)
1889 {
1890     BlockdevBackupState *state = opaque;
1891 
1892     if (state->job) {
1893         job_cancel_sync(&state->job->job, true);
1894     }
1895 }
1896 
1897 static void blockdev_backup_clean(void *opaque)
1898 {
1899     g_autofree BlockdevBackupState *state = opaque;
1900     AioContext *aio_context;
1901 
1902     if (!state->bs) {
1903         return;
1904     }
1905 
1906     aio_context = bdrv_get_aio_context(state->bs);
1907     aio_context_acquire(aio_context);
1908 
1909     bdrv_drained_end(state->bs);
1910 
1911     aio_context_release(aio_context);
1912 }
1913 
1914 typedef struct BlockDirtyBitmapState {
1915     BdrvDirtyBitmap *bitmap;
1916     BlockDriverState *bs;
1917     HBitmap *backup;
1918     bool was_enabled;
1919 } BlockDirtyBitmapState;
1920 
1921 static void block_dirty_bitmap_add_abort(void *opaque);
1922 TransactionActionDrv block_dirty_bitmap_add_drv = {
1923     .abort = block_dirty_bitmap_add_abort,
1924     .clean = g_free,
1925 };
1926 
1927 static void block_dirty_bitmap_add_action(BlockDirtyBitmapAdd *action,
1928                                           Transaction *tran, Error **errp)
1929 {
1930     Error *local_err = NULL;
1931     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1932 
1933     tran_add(tran, &block_dirty_bitmap_add_drv, state);
1934 
1935     /* AIO context taken and released within qmp_block_dirty_bitmap_add */
1936     qmp_block_dirty_bitmap_add(action->node, action->name,
1937                                action->has_granularity, action->granularity,
1938                                action->has_persistent, action->persistent,
1939                                action->has_disabled, action->disabled,
1940                                &local_err);
1941 
1942     if (!local_err) {
1943         state->bitmap = block_dirty_bitmap_lookup(action->node, action->name,
1944                                                   NULL, &error_abort);
1945     } else {
1946         error_propagate(errp, local_err);
1947     }
1948 }
1949 
1950 static void block_dirty_bitmap_add_abort(void *opaque)
1951 {
1952     BlockDirtyBitmapState *state = opaque;
1953 
1954     if (state->bitmap) {
1955         bdrv_release_dirty_bitmap(state->bitmap);
1956     }
1957 }
1958 
1959 static void block_dirty_bitmap_restore(void *opaque);
1960 static void block_dirty_bitmap_free_backup(void *opaque);
1961 TransactionActionDrv block_dirty_bitmap_clear_drv = {
1962     .abort = block_dirty_bitmap_restore,
1963     .commit = block_dirty_bitmap_free_backup,
1964     .clean = g_free,
1965 };
1966 
1967 static void block_dirty_bitmap_clear_action(BlockDirtyBitmap *action,
1968                                             Transaction *tran, Error **errp)
1969 {
1970     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1971 
1972     tran_add(tran, &block_dirty_bitmap_clear_drv, state);
1973 
1974     state->bitmap = block_dirty_bitmap_lookup(action->node,
1975                                               action->name,
1976                                               &state->bs,
1977                                               errp);
1978     if (!state->bitmap) {
1979         return;
1980     }
1981 
1982     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_DEFAULT, errp)) {
1983         return;
1984     }
1985 
1986     bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
1987 }
1988 
1989 static void block_dirty_bitmap_restore(void *opaque)
1990 {
1991     BlockDirtyBitmapState *state = opaque;
1992 
1993     if (state->backup) {
1994         bdrv_restore_dirty_bitmap(state->bitmap, state->backup);
1995     }
1996 }
1997 
1998 static void block_dirty_bitmap_free_backup(void *opaque)
1999 {
2000     BlockDirtyBitmapState *state = opaque;
2001 
2002     hbitmap_free(state->backup);
2003 }
2004 
2005 static void block_dirty_bitmap_enable_abort(void *opaque);
2006 TransactionActionDrv block_dirty_bitmap_enable_drv = {
2007     .abort = block_dirty_bitmap_enable_abort,
2008     .clean = g_free,
2009 };
2010 
2011 static void block_dirty_bitmap_enable_action(BlockDirtyBitmap *action,
2012                                              Transaction *tran, Error **errp)
2013 {
2014     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2015 
2016     tran_add(tran, &block_dirty_bitmap_enable_drv, state);
2017 
2018     state->bitmap = block_dirty_bitmap_lookup(action->node,
2019                                               action->name,
2020                                               NULL,
2021                                               errp);
2022     if (!state->bitmap) {
2023         return;
2024     }
2025 
2026     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2027         return;
2028     }
2029 
2030     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2031     bdrv_enable_dirty_bitmap(state->bitmap);
2032 }
2033 
2034 static void block_dirty_bitmap_enable_abort(void *opaque)
2035 {
2036     BlockDirtyBitmapState *state = opaque;
2037 
2038     if (!state->was_enabled) {
2039         bdrv_disable_dirty_bitmap(state->bitmap);
2040     }
2041 }
2042 
2043 static void block_dirty_bitmap_disable_abort(void *opaque);
2044 TransactionActionDrv block_dirty_bitmap_disable_drv = {
2045     .abort = block_dirty_bitmap_disable_abort,
2046     .clean = g_free,
2047 };
2048 
2049 static void block_dirty_bitmap_disable_action(BlockDirtyBitmap *action,
2050                                               Transaction *tran, Error **errp)
2051 {
2052     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2053 
2054     tran_add(tran, &block_dirty_bitmap_disable_drv, state);
2055 
2056     state->bitmap = block_dirty_bitmap_lookup(action->node,
2057                                               action->name,
2058                                               NULL,
2059                                               errp);
2060     if (!state->bitmap) {
2061         return;
2062     }
2063 
2064     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2065         return;
2066     }
2067 
2068     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2069     bdrv_disable_dirty_bitmap(state->bitmap);
2070 }
2071 
2072 static void block_dirty_bitmap_disable_abort(void *opaque)
2073 {
2074     BlockDirtyBitmapState *state = opaque;
2075 
2076     if (state->was_enabled) {
2077         bdrv_enable_dirty_bitmap(state->bitmap);
2078     }
2079 }
2080 
2081 TransactionActionDrv block_dirty_bitmap_merge_drv = {
2082     .commit = block_dirty_bitmap_free_backup,
2083     .abort = block_dirty_bitmap_restore,
2084     .clean = g_free,
2085 };
2086 
2087 static void block_dirty_bitmap_merge_action(BlockDirtyBitmapMerge *action,
2088                                             Transaction *tran, Error **errp)
2089 {
2090     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2091 
2092     tran_add(tran, &block_dirty_bitmap_merge_drv, state);
2093 
2094     state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
2095                                              action->bitmaps, &state->backup,
2096                                              errp);
2097 }
2098 
2099 static void block_dirty_bitmap_remove_commit(void *opaque);
2100 static void block_dirty_bitmap_remove_abort(void *opaque);
2101 TransactionActionDrv block_dirty_bitmap_remove_drv = {
2102     .commit = block_dirty_bitmap_remove_commit,
2103     .abort = block_dirty_bitmap_remove_abort,
2104     .clean = g_free,
2105 };
2106 
2107 static void block_dirty_bitmap_remove_action(BlockDirtyBitmap *action,
2108                                              Transaction *tran, Error **errp)
2109 {
2110     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2111 
2112     tran_add(tran, &block_dirty_bitmap_remove_drv, state);
2113 
2114 
2115     state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
2116                                               false, &state->bs, errp);
2117     if (state->bitmap) {
2118         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
2119         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
2120     }
2121 }
2122 
2123 static void block_dirty_bitmap_remove_abort(void *opaque)
2124 {
2125     BlockDirtyBitmapState *state = opaque;
2126 
2127     if (state->bitmap) {
2128         bdrv_dirty_bitmap_skip_store(state->bitmap, false);
2129         bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2130     }
2131 }
2132 
2133 static void block_dirty_bitmap_remove_commit(void *opaque)
2134 {
2135     BlockDirtyBitmapState *state = opaque;
2136 
2137     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2138     bdrv_release_dirty_bitmap(state->bitmap);
2139 }
2140 
2141 static void abort_commit(void *opaque);
2142 TransactionActionDrv abort_drv = {
2143     .commit = abort_commit,
2144 };
2145 
2146 static void abort_action(Transaction *tran, Error **errp)
2147 {
2148     tran_add(tran, &abort_drv, NULL);
2149     error_setg(errp, "Transaction aborted using Abort action");
2150 }
2151 
2152 static void abort_commit(void *opaque)
2153 {
2154     g_assert_not_reached(); /* this action never succeeds */
2155 }
2156 
2157 static void transaction_action(TransactionAction *act, JobTxn *block_job_txn,
2158                                Transaction *tran, Error **errp)
2159 {
2160     switch (act->type) {
2161     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
2162     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
2163         external_snapshot_action(act, tran, errp);
2164         return;
2165     case TRANSACTION_ACTION_KIND_DRIVE_BACKUP:
2166         drive_backup_action(act->u.drive_backup.data,
2167                             block_job_txn, tran, errp);
2168         return;
2169     case TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP:
2170         blockdev_backup_action(act->u.blockdev_backup.data,
2171                                block_job_txn, tran, errp);
2172         return;
2173     case TRANSACTION_ACTION_KIND_ABORT:
2174         abort_action(tran, errp);
2175         return;
2176     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC:
2177         internal_snapshot_action(act->u.blockdev_snapshot_internal_sync.data,
2178                                  tran, errp);
2179         return;
2180     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD:
2181         block_dirty_bitmap_add_action(act->u.block_dirty_bitmap_add.data,
2182                                       tran, errp);
2183         return;
2184     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR:
2185         block_dirty_bitmap_clear_action(act->u.block_dirty_bitmap_clear.data,
2186                                         tran, errp);
2187         return;
2188     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE:
2189         block_dirty_bitmap_enable_action(act->u.block_dirty_bitmap_enable.data,
2190                                          tran, errp);
2191         return;
2192     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE:
2193         block_dirty_bitmap_disable_action(
2194                 act->u.block_dirty_bitmap_disable.data, tran, errp);
2195         return;
2196     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE:
2197         block_dirty_bitmap_merge_action(act->u.block_dirty_bitmap_merge.data,
2198                                         tran, errp);
2199         return;
2200     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_REMOVE:
2201         block_dirty_bitmap_remove_action(act->u.block_dirty_bitmap_remove.data,
2202                                          tran, errp);
2203         return;
2204     /*
2205      * Where are transactions for MIRROR, COMMIT and STREAM?
2206      * Although these blockjobs use transaction callbacks like the backup job,
2207      * these jobs do not necessarily adhere to transaction semantics.
2208      * These jobs may not fully undo all of their actions on abort, nor do they
2209      * necessarily work in transactions with more than one job in them.
2210      */
2211     case TRANSACTION_ACTION_KIND__MAX:
2212     default:
2213         g_assert_not_reached();
2214     };
2215 }
2216 
2217 
2218 /*
2219  * 'Atomic' group operations.  The operations are performed as a set, and if
2220  * any fail then we roll back all operations in the group.
2221  *
2222  * Always run under BQL.
2223  */
2224 void qmp_transaction(TransactionActionList *actions,
2225                      struct TransactionProperties *properties,
2226                      Error **errp)
2227 {
2228     TransactionActionList *act;
2229     JobTxn *block_job_txn = NULL;
2230     Error *local_err = NULL;
2231     Transaction *tran;
2232     ActionCompletionMode comp_mode =
2233         properties ? properties->completion_mode :
2234         ACTION_COMPLETION_MODE_INDIVIDUAL;
2235 
2236     GLOBAL_STATE_CODE();
2237 
2238     /* Does this transaction get canceled as a group on failure?
2239      * If not, we don't really need to make a JobTxn.
2240      */
2241     if (comp_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
2242         for (act = actions; act; act = act->next) {
2243             TransactionActionKind type = act->value->type;
2244 
2245             if (type != TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP &&
2246                 type != TRANSACTION_ACTION_KIND_DRIVE_BACKUP)
2247             {
2248                 error_setg(errp,
2249                            "Action '%s' does not support transaction property "
2250                            "completion-mode = %s",
2251                            TransactionActionKind_str(type),
2252                            ActionCompletionMode_str(comp_mode));
2253                 return;
2254             }
2255         }
2256 
2257         block_job_txn = job_txn_new();
2258     }
2259 
2260     /* drain all i/o before any operations */
2261     bdrv_drain_all();
2262 
2263     tran = tran_new();
2264 
2265     /* We don't do anything in this loop that commits us to the operations */
2266     for (act = actions; act; act = act->next) {
2267         transaction_action(act->value, block_job_txn, tran, &local_err);
2268         if (local_err) {
2269             error_propagate(errp, local_err);
2270             goto delete_and_fail;
2271         }
2272     }
2273 
2274     tran_commit(tran);
2275 
2276     /* success */
2277     goto exit;
2278 
2279 delete_and_fail:
2280     /* failure, and it is all-or-none; roll back all operations */
2281     tran_abort(tran);
2282 exit:
2283     job_txn_unref(block_job_txn);
2284 }
2285 
2286 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
2287                                                               const char *name,
2288                                                               Error **errp)
2289 {
2290     BdrvDirtyBitmap *bitmap;
2291     BlockDriverState *bs;
2292     BlockDirtyBitmapSha256 *ret = NULL;
2293     char *sha256;
2294 
2295     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
2296     if (!bitmap || !bs) {
2297         return NULL;
2298     }
2299 
2300     sha256 = bdrv_dirty_bitmap_sha256(bitmap, errp);
2301     if (sha256 == NULL) {
2302         return NULL;
2303     }
2304 
2305     ret = g_new(BlockDirtyBitmapSha256, 1);
2306     ret->sha256 = sha256;
2307 
2308     return ret;
2309 }
2310 
2311 void coroutine_fn qmp_block_resize(const char *device, const char *node_name,
2312                                    int64_t size, Error **errp)
2313 {
2314     Error *local_err = NULL;
2315     BlockBackend *blk;
2316     BlockDriverState *bs;
2317     AioContext *old_ctx;
2318 
2319     bs = bdrv_lookup_bs(device, node_name, &local_err);
2320     if (local_err) {
2321         error_propagate(errp, local_err);
2322         return;
2323     }
2324 
2325     if (size < 0) {
2326         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
2327         return;
2328     }
2329 
2330     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
2331         error_setg(errp, QERR_DEVICE_IN_USE, device);
2332         return;
2333     }
2334 
2335     blk = blk_co_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, errp);
2336     if (!blk) {
2337         return;
2338     }
2339 
2340     bdrv_co_lock(bs);
2341     bdrv_drained_begin(bs);
2342     bdrv_co_unlock(bs);
2343 
2344     old_ctx = bdrv_co_enter(bs);
2345     blk_co_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
2346     bdrv_co_leave(bs, old_ctx);
2347 
2348     bdrv_co_lock(bs);
2349     bdrv_drained_end(bs);
2350     blk_co_unref(blk);
2351     bdrv_co_unlock(bs);
2352 }
2353 
2354 void qmp_block_stream(const char *job_id, const char *device,
2355                       const char *base,
2356                       const char *base_node,
2357                       const char *backing_file,
2358                       const char *bottom,
2359                       bool has_speed, int64_t speed,
2360                       bool has_on_error, BlockdevOnError on_error,
2361                       const char *filter_node_name,
2362                       bool has_auto_finalize, bool auto_finalize,
2363                       bool has_auto_dismiss, bool auto_dismiss,
2364                       Error **errp)
2365 {
2366     BlockDriverState *bs, *iter, *iter_end;
2367     BlockDriverState *base_bs = NULL;
2368     BlockDriverState *bottom_bs = NULL;
2369     AioContext *aio_context;
2370     Error *local_err = NULL;
2371     int job_flags = JOB_DEFAULT;
2372 
2373     if (base && base_node) {
2374         error_setg(errp, "'base' and 'base-node' cannot be specified "
2375                    "at the same time");
2376         return;
2377     }
2378 
2379     if (base && bottom) {
2380         error_setg(errp, "'base' and 'bottom' cannot be specified "
2381                    "at the same time");
2382         return;
2383     }
2384 
2385     if (bottom && base_node) {
2386         error_setg(errp, "'bottom' and 'base-node' cannot be specified "
2387                    "at the same time");
2388         return;
2389     }
2390 
2391     if (!has_on_error) {
2392         on_error = BLOCKDEV_ON_ERROR_REPORT;
2393     }
2394 
2395     bs = bdrv_lookup_bs(device, device, errp);
2396     if (!bs) {
2397         return;
2398     }
2399 
2400     aio_context = bdrv_get_aio_context(bs);
2401     aio_context_acquire(aio_context);
2402 
2403     if (base) {
2404         base_bs = bdrv_find_backing_image(bs, base);
2405         if (base_bs == NULL) {
2406             error_setg(errp, "Can't find '%s' in the backing chain", base);
2407             goto out;
2408         }
2409         assert(bdrv_get_aio_context(base_bs) == aio_context);
2410     }
2411 
2412     if (base_node) {
2413         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2414         if (!base_bs) {
2415             goto out;
2416         }
2417         if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) {
2418             error_setg(errp, "Node '%s' is not a backing image of '%s'",
2419                        base_node, device);
2420             goto out;
2421         }
2422         assert(bdrv_get_aio_context(base_bs) == aio_context);
2423         bdrv_refresh_filename(base_bs);
2424     }
2425 
2426     if (bottom) {
2427         bottom_bs = bdrv_lookup_bs(NULL, bottom, errp);
2428         if (!bottom_bs) {
2429             goto out;
2430         }
2431         if (!bottom_bs->drv) {
2432             error_setg(errp, "Node '%s' is not open", bottom);
2433             goto out;
2434         }
2435         if (bottom_bs->drv->is_filter) {
2436             error_setg(errp, "Node '%s' is a filter, use a non-filter node "
2437                        "as 'bottom'", bottom);
2438             goto out;
2439         }
2440         if (!bdrv_chain_contains(bs, bottom_bs)) {
2441             error_setg(errp, "Node '%s' is not in a chain starting from '%s'",
2442                        bottom, device);
2443             goto out;
2444         }
2445         assert(bdrv_get_aio_context(bottom_bs) == aio_context);
2446     }
2447 
2448     /*
2449      * Check for op blockers in the whole chain between bs and base (or bottom)
2450      */
2451     iter_end = bottom ? bdrv_filter_or_cow_bs(bottom_bs) : base_bs;
2452     for (iter = bs; iter && iter != iter_end;
2453          iter = bdrv_filter_or_cow_bs(iter))
2454     {
2455         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
2456             goto out;
2457         }
2458     }
2459 
2460     /* if we are streaming the entire chain, the result will have no backing
2461      * file, and specifying one is therefore an error */
2462     if (!base_bs && backing_file) {
2463         error_setg(errp, "backing file specified, but streaming the "
2464                          "entire chain");
2465         goto out;
2466     }
2467 
2468     if (has_auto_finalize && !auto_finalize) {
2469         job_flags |= JOB_MANUAL_FINALIZE;
2470     }
2471     if (has_auto_dismiss && !auto_dismiss) {
2472         job_flags |= JOB_MANUAL_DISMISS;
2473     }
2474 
2475     stream_start(job_id, bs, base_bs, backing_file,
2476                  bottom_bs, job_flags, has_speed ? speed : 0, on_error,
2477                  filter_node_name, &local_err);
2478     if (local_err) {
2479         error_propagate(errp, local_err);
2480         goto out;
2481     }
2482 
2483     trace_qmp_block_stream(bs);
2484 
2485 out:
2486     aio_context_release(aio_context);
2487 }
2488 
2489 void qmp_block_commit(const char *job_id, const char *device,
2490                       const char *base_node,
2491                       const char *base,
2492                       const char *top_node,
2493                       const char *top,
2494                       const char *backing_file,
2495                       bool has_speed, int64_t speed,
2496                       bool has_on_error, BlockdevOnError on_error,
2497                       const char *filter_node_name,
2498                       bool has_auto_finalize, bool auto_finalize,
2499                       bool has_auto_dismiss, bool auto_dismiss,
2500                       Error **errp)
2501 {
2502     BlockDriverState *bs;
2503     BlockDriverState *iter;
2504     BlockDriverState *base_bs, *top_bs;
2505     AioContext *aio_context;
2506     Error *local_err = NULL;
2507     int job_flags = JOB_DEFAULT;
2508     uint64_t top_perm, top_shared;
2509 
2510     if (!has_speed) {
2511         speed = 0;
2512     }
2513     if (!has_on_error) {
2514         on_error = BLOCKDEV_ON_ERROR_REPORT;
2515     }
2516     if (has_auto_finalize && !auto_finalize) {
2517         job_flags |= JOB_MANUAL_FINALIZE;
2518     }
2519     if (has_auto_dismiss && !auto_dismiss) {
2520         job_flags |= JOB_MANUAL_DISMISS;
2521     }
2522 
2523     /* Important Note:
2524      *  libvirt relies on the DeviceNotFound error class in order to probe for
2525      *  live commit feature versions; for this to work, we must make sure to
2526      *  perform the device lookup before any generic errors that may occur in a
2527      *  scenario in which all optional arguments are omitted. */
2528     bs = qmp_get_root_bs(device, &local_err);
2529     if (!bs) {
2530         bs = bdrv_lookup_bs(device, device, NULL);
2531         if (!bs) {
2532             error_free(local_err);
2533             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
2534                       "Device '%s' not found", device);
2535         } else {
2536             error_propagate(errp, local_err);
2537         }
2538         return;
2539     }
2540 
2541     aio_context = bdrv_get_aio_context(bs);
2542     aio_context_acquire(aio_context);
2543 
2544     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
2545         goto out;
2546     }
2547 
2548     /* default top_bs is the active layer */
2549     top_bs = bs;
2550 
2551     if (top_node && top) {
2552         error_setg(errp, "'top-node' and 'top' are mutually exclusive");
2553         goto out;
2554     } else if (top_node) {
2555         top_bs = bdrv_lookup_bs(NULL, top_node, errp);
2556         if (top_bs == NULL) {
2557             goto out;
2558         }
2559         if (!bdrv_chain_contains(bs, top_bs)) {
2560             error_setg(errp, "'%s' is not in this backing file chain",
2561                        top_node);
2562             goto out;
2563         }
2564     } else if (top) {
2565         /* This strcmp() is just a shortcut, there is no need to
2566          * refresh @bs's filename.  If it mismatches,
2567          * bdrv_find_backing_image() will do the refresh and may still
2568          * return @bs. */
2569         if (strcmp(bs->filename, top) != 0) {
2570             top_bs = bdrv_find_backing_image(bs, top);
2571         }
2572     }
2573 
2574     if (top_bs == NULL) {
2575         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
2576         goto out;
2577     }
2578 
2579     assert(bdrv_get_aio_context(top_bs) == aio_context);
2580 
2581     if (base_node && base) {
2582         error_setg(errp, "'base-node' and 'base' are mutually exclusive");
2583         goto out;
2584     } else if (base_node) {
2585         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2586         if (base_bs == NULL) {
2587             goto out;
2588         }
2589         if (!bdrv_chain_contains(top_bs, base_bs)) {
2590             error_setg(errp, "'%s' is not in this backing file chain",
2591                        base_node);
2592             goto out;
2593         }
2594     } else if (base) {
2595         base_bs = bdrv_find_backing_image(top_bs, base);
2596         if (base_bs == NULL) {
2597             error_setg(errp, "Can't find '%s' in the backing chain", base);
2598             goto out;
2599         }
2600     } else {
2601         base_bs = bdrv_find_base(top_bs);
2602         if (base_bs == NULL) {
2603             error_setg(errp, "There is no backimg image");
2604             goto out;
2605         }
2606     }
2607 
2608     assert(bdrv_get_aio_context(base_bs) == aio_context);
2609 
2610     for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs);
2611          iter = bdrv_filter_or_cow_bs(iter))
2612     {
2613         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2614             goto out;
2615         }
2616     }
2617 
2618     /* Do not allow attempts to commit an image into itself */
2619     if (top_bs == base_bs) {
2620         error_setg(errp, "cannot commit an image into itself");
2621         goto out;
2622     }
2623 
2624     /*
2625      * Active commit is required if and only if someone has taken a
2626      * WRITE permission on the top node.  Historically, we have always
2627      * used active commit for top nodes, so continue that practice
2628      * lest we possibly break clients that rely on this behavior, e.g.
2629      * to later attach this node to a writing parent.
2630      * (Active commit is never really wrong.)
2631      */
2632     bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared);
2633     if (top_perm & BLK_PERM_WRITE ||
2634         bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs))
2635     {
2636         if (backing_file) {
2637             if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) {
2638                 error_setg(errp, "'backing-file' specified,"
2639                                  " but 'top' is the active layer");
2640             } else {
2641                 error_setg(errp, "'backing-file' specified, but 'top' has a "
2642                                  "writer on it");
2643             }
2644             goto out;
2645         }
2646         if (!job_id) {
2647             /*
2648              * Emulate here what block_job_create() does, because it
2649              * is possible that @bs != @top_bs (the block job should
2650              * be named after @bs, even if @top_bs is the actual
2651              * source)
2652              */
2653             job_id = bdrv_get_device_name(bs);
2654         }
2655         commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error,
2656                             filter_node_name, NULL, NULL, false, &local_err);
2657     } else {
2658         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
2659         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2660             goto out;
2661         }
2662         commit_start(job_id, bs, base_bs, top_bs, job_flags,
2663                      speed, on_error, backing_file,
2664                      filter_node_name, &local_err);
2665     }
2666     if (local_err != NULL) {
2667         error_propagate(errp, local_err);
2668         goto out;
2669     }
2670 
2671 out:
2672     aio_context_release(aio_context);
2673 }
2674 
2675 /* Common QMP interface for drive-backup and blockdev-backup */
2676 static BlockJob *do_backup_common(BackupCommon *backup,
2677                                   BlockDriverState *bs,
2678                                   BlockDriverState *target_bs,
2679                                   AioContext *aio_context,
2680                                   JobTxn *txn, Error **errp)
2681 {
2682     BlockJob *job = NULL;
2683     BdrvDirtyBitmap *bmap = NULL;
2684     BackupPerf perf = { .max_workers = 64 };
2685     int job_flags = JOB_DEFAULT;
2686 
2687     if (!backup->has_speed) {
2688         backup->speed = 0;
2689     }
2690     if (!backup->has_on_source_error) {
2691         backup->on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2692     }
2693     if (!backup->has_on_target_error) {
2694         backup->on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2695     }
2696     if (!backup->has_auto_finalize) {
2697         backup->auto_finalize = true;
2698     }
2699     if (!backup->has_auto_dismiss) {
2700         backup->auto_dismiss = true;
2701     }
2702     if (!backup->has_compress) {
2703         backup->compress = false;
2704     }
2705 
2706     if (backup->x_perf) {
2707         if (backup->x_perf->has_use_copy_range) {
2708             perf.use_copy_range = backup->x_perf->use_copy_range;
2709         }
2710         if (backup->x_perf->has_max_workers) {
2711             perf.max_workers = backup->x_perf->max_workers;
2712         }
2713         if (backup->x_perf->has_max_chunk) {
2714             perf.max_chunk = backup->x_perf->max_chunk;
2715         }
2716     }
2717 
2718     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||
2719         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
2720         /* done before desugaring 'incremental' to print the right message */
2721         if (!backup->bitmap) {
2722             error_setg(errp, "must provide a valid bitmap name for "
2723                        "'%s' sync mode", MirrorSyncMode_str(backup->sync));
2724             return NULL;
2725         }
2726     }
2727 
2728     if (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL) {
2729         if (backup->has_bitmap_mode &&
2730             backup->bitmap_mode != BITMAP_SYNC_MODE_ON_SUCCESS) {
2731             error_setg(errp, "Bitmap sync mode must be '%s' "
2732                        "when using sync mode '%s'",
2733                        BitmapSyncMode_str(BITMAP_SYNC_MODE_ON_SUCCESS),
2734                        MirrorSyncMode_str(backup->sync));
2735             return NULL;
2736         }
2737         backup->has_bitmap_mode = true;
2738         backup->sync = MIRROR_SYNC_MODE_BITMAP;
2739         backup->bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
2740     }
2741 
2742     if (backup->bitmap) {
2743         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
2744         if (!bmap) {
2745             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
2746             return NULL;
2747         }
2748         if (!backup->has_bitmap_mode) {
2749             error_setg(errp, "Bitmap sync mode must be given "
2750                        "when providing a bitmap");
2751             return NULL;
2752         }
2753         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2754             return NULL;
2755         }
2756 
2757         /* This does not produce a useful bitmap artifact: */
2758         if (backup->sync == MIRROR_SYNC_MODE_NONE) {
2759             error_setg(errp, "sync mode '%s' does not produce meaningful bitmap"
2760                        " outputs", MirrorSyncMode_str(backup->sync));
2761             return NULL;
2762         }
2763 
2764         /* If the bitmap isn't used for input or output, this is useless: */
2765         if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER &&
2766             backup->sync != MIRROR_SYNC_MODE_BITMAP) {
2767             error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect"
2768                        " when combined with sync mode '%s'",
2769                        BitmapSyncMode_str(backup->bitmap_mode),
2770                        MirrorSyncMode_str(backup->sync));
2771             return NULL;
2772         }
2773     }
2774 
2775     if (!backup->bitmap && backup->has_bitmap_mode) {
2776         error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
2777         return NULL;
2778     }
2779 
2780     if (!backup->auto_finalize) {
2781         job_flags |= JOB_MANUAL_FINALIZE;
2782     }
2783     if (!backup->auto_dismiss) {
2784         job_flags |= JOB_MANUAL_DISMISS;
2785     }
2786 
2787     job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
2788                             backup->sync, bmap, backup->bitmap_mode,
2789                             backup->compress,
2790                             backup->filter_node_name,
2791                             &perf,
2792                             backup->on_source_error,
2793                             backup->on_target_error,
2794                             job_flags, NULL, NULL, txn, errp);
2795     return job;
2796 }
2797 
2798 void qmp_drive_backup(DriveBackup *backup, Error **errp)
2799 {
2800     TransactionAction action = {
2801         .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
2802         .u.drive_backup.data = backup,
2803     };
2804     blockdev_do_action(&action, errp);
2805 }
2806 
2807 BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
2808                                                  bool flat,
2809                                                  Error **errp)
2810 {
2811     bool return_flat = has_flat && flat;
2812 
2813     return bdrv_named_nodes_list(return_flat, errp);
2814 }
2815 
2816 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
2817 {
2818     return bdrv_get_xdbg_block_graph(errp);
2819 }
2820 
2821 void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)
2822 {
2823     TransactionAction action = {
2824         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,
2825         .u.blockdev_backup.data = backup,
2826     };
2827     blockdev_do_action(&action, errp);
2828 }
2829 
2830 /* Parameter check and block job starting for drive mirroring.
2831  * Caller should hold @device and @target's aio context (must be the same).
2832  **/
2833 static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
2834                                    BlockDriverState *target,
2835                                    const char *replaces,
2836                                    enum MirrorSyncMode sync,
2837                                    BlockMirrorBackingMode backing_mode,
2838                                    bool zero_target,
2839                                    bool has_speed, int64_t speed,
2840                                    bool has_granularity, uint32_t granularity,
2841                                    bool has_buf_size, int64_t buf_size,
2842                                    bool has_on_source_error,
2843                                    BlockdevOnError on_source_error,
2844                                    bool has_on_target_error,
2845                                    BlockdevOnError on_target_error,
2846                                    bool has_unmap, bool unmap,
2847                                    const char *filter_node_name,
2848                                    bool has_copy_mode, MirrorCopyMode copy_mode,
2849                                    bool has_auto_finalize, bool auto_finalize,
2850                                    bool has_auto_dismiss, bool auto_dismiss,
2851                                    Error **errp)
2852 {
2853     BlockDriverState *unfiltered_bs;
2854     int job_flags = JOB_DEFAULT;
2855 
2856     GLOBAL_STATE_CODE();
2857     GRAPH_RDLOCK_GUARD_MAINLOOP();
2858 
2859     if (!has_speed) {
2860         speed = 0;
2861     }
2862     if (!has_on_source_error) {
2863         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2864     }
2865     if (!has_on_target_error) {
2866         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2867     }
2868     if (!has_granularity) {
2869         granularity = 0;
2870     }
2871     if (!has_buf_size) {
2872         buf_size = 0;
2873     }
2874     if (!has_unmap) {
2875         unmap = true;
2876     }
2877     if (!has_copy_mode) {
2878         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
2879     }
2880     if (has_auto_finalize && !auto_finalize) {
2881         job_flags |= JOB_MANUAL_FINALIZE;
2882     }
2883     if (has_auto_dismiss && !auto_dismiss) {
2884         job_flags |= JOB_MANUAL_DISMISS;
2885     }
2886 
2887     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
2888         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2889                    "a value in range [512B, 64MB]");
2890         return;
2891     }
2892     if (granularity & (granularity - 1)) {
2893         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2894                    "a power of 2");
2895         return;
2896     }
2897 
2898     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2899         return;
2900     }
2901     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
2902         return;
2903     }
2904 
2905     if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) {
2906         sync = MIRROR_SYNC_MODE_FULL;
2907     }
2908 
2909     if (!replaces) {
2910         /* We want to mirror from @bs, but keep implicit filters on top */
2911         unfiltered_bs = bdrv_skip_implicit_filters(bs);
2912         if (unfiltered_bs != bs) {
2913             replaces = unfiltered_bs->node_name;
2914         }
2915     }
2916 
2917     if (replaces) {
2918         BlockDriverState *to_replace_bs;
2919         AioContext *replace_aio_context;
2920         int64_t bs_size, replace_size;
2921 
2922         bs_size = bdrv_getlength(bs);
2923         if (bs_size < 0) {
2924             error_setg_errno(errp, -bs_size, "Failed to query device's size");
2925             return;
2926         }
2927 
2928         to_replace_bs = check_to_replace_node(bs, replaces, errp);
2929         if (!to_replace_bs) {
2930             return;
2931         }
2932 
2933         replace_aio_context = bdrv_get_aio_context(to_replace_bs);
2934         aio_context_acquire(replace_aio_context);
2935         replace_size = bdrv_getlength(to_replace_bs);
2936         aio_context_release(replace_aio_context);
2937 
2938         if (replace_size < 0) {
2939             error_setg_errno(errp, -replace_size,
2940                              "Failed to query the replacement node's size");
2941             return;
2942         }
2943         if (bs_size != replace_size) {
2944             error_setg(errp, "cannot replace image with a mirror image of "
2945                              "different size");
2946             return;
2947         }
2948     }
2949 
2950     /* pass the node name to replace to mirror start since it's loose coupling
2951      * and will allow to check whether the node still exist at mirror completion
2952      */
2953     mirror_start(job_id, bs, target,
2954                  replaces, job_flags,
2955                  speed, granularity, buf_size, sync, backing_mode, zero_target,
2956                  on_source_error, on_target_error, unmap, filter_node_name,
2957                  copy_mode, errp);
2958 }
2959 
2960 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
2961 {
2962     BlockDriverState *bs;
2963     BlockDriverState *target_backing_bs, *target_bs;
2964     AioContext *aio_context;
2965     AioContext *old_context;
2966     BlockMirrorBackingMode backing_mode;
2967     Error *local_err = NULL;
2968     QDict *options = NULL;
2969     int flags;
2970     int64_t size;
2971     const char *format = arg->format;
2972     bool zero_target;
2973     int ret;
2974 
2975     bs = qmp_get_root_bs(arg->device, errp);
2976     if (!bs) {
2977         return;
2978     }
2979 
2980     /* Early check to avoid creating target */
2981     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2982         return;
2983     }
2984 
2985     aio_context = bdrv_get_aio_context(bs);
2986     aio_context_acquire(aio_context);
2987 
2988     if (!arg->has_mode) {
2989         arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
2990     }
2991 
2992     if (!arg->format) {
2993         format = (arg->mode == NEW_IMAGE_MODE_EXISTING
2994                   ? NULL : bs->drv->format_name);
2995     }
2996 
2997     flags = bs->open_flags | BDRV_O_RDWR;
2998     target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs));
2999     if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) {
3000         arg->sync = MIRROR_SYNC_MODE_FULL;
3001     }
3002     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
3003         target_backing_bs = bs;
3004     }
3005 
3006     size = bdrv_getlength(bs);
3007     if (size < 0) {
3008         error_setg_errno(errp, -size, "bdrv_getlength failed");
3009         goto out;
3010     }
3011 
3012     if (arg->replaces) {
3013         if (!arg->node_name) {
3014             error_setg(errp, "a node-name must be provided when replacing a"
3015                              " named node of the graph");
3016             goto out;
3017         }
3018     }
3019 
3020     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
3021         backing_mode = MIRROR_SOURCE_BACKING_CHAIN;
3022     } else {
3023         backing_mode = MIRROR_OPEN_BACKING_CHAIN;
3024     }
3025 
3026     /* Don't open backing image in create() */
3027     flags |= BDRV_O_NO_BACKING;
3028 
3029     if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs)
3030         && arg->mode != NEW_IMAGE_MODE_EXISTING)
3031     {
3032         /* create new image w/o backing file */
3033         assert(format);
3034         bdrv_img_create(arg->target, format,
3035                         NULL, NULL, NULL, size, flags, false, &local_err);
3036     } else {
3037         /* Implicit filters should not appear in the filename */
3038         BlockDriverState *explicit_backing =
3039             bdrv_skip_implicit_filters(target_backing_bs);
3040 
3041         switch (arg->mode) {
3042         case NEW_IMAGE_MODE_EXISTING:
3043             break;
3044         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
3045             /* create new image with backing file */
3046             bdrv_refresh_filename(explicit_backing);
3047             bdrv_img_create(arg->target, format,
3048                             explicit_backing->filename,
3049                             explicit_backing->drv->format_name,
3050                             NULL, size, flags, false, &local_err);
3051             break;
3052         default:
3053             abort();
3054         }
3055     }
3056 
3057     if (local_err) {
3058         error_propagate(errp, local_err);
3059         goto out;
3060     }
3061 
3062     options = qdict_new();
3063     if (arg->node_name) {
3064         qdict_put_str(options, "node-name", arg->node_name);
3065     }
3066     if (format) {
3067         qdict_put_str(options, "driver", format);
3068     }
3069 
3070     /* Mirroring takes care of copy-on-write using the source's backing
3071      * file.
3072      */
3073     target_bs = bdrv_open(arg->target, NULL, options, flags, errp);
3074     if (!target_bs) {
3075         goto out;
3076     }
3077 
3078     zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
3079                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||
3080                     !bdrv_has_zero_init(target_bs)));
3081 
3082 
3083     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3084     old_context = bdrv_get_aio_context(target_bs);
3085     aio_context_release(aio_context);
3086     aio_context_acquire(old_context);
3087 
3088     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3089     if (ret < 0) {
3090         bdrv_unref(target_bs);
3091         aio_context_release(old_context);
3092         return;
3093     }
3094 
3095     aio_context_release(old_context);
3096     aio_context_acquire(aio_context);
3097 
3098     blockdev_mirror_common(arg->job_id, bs, target_bs,
3099                            arg->replaces, arg->sync,
3100                            backing_mode, zero_target,
3101                            arg->has_speed, arg->speed,
3102                            arg->has_granularity, arg->granularity,
3103                            arg->has_buf_size, arg->buf_size,
3104                            arg->has_on_source_error, arg->on_source_error,
3105                            arg->has_on_target_error, arg->on_target_error,
3106                            arg->has_unmap, arg->unmap,
3107                            NULL,
3108                            arg->has_copy_mode, arg->copy_mode,
3109                            arg->has_auto_finalize, arg->auto_finalize,
3110                            arg->has_auto_dismiss, arg->auto_dismiss,
3111                            errp);
3112     bdrv_unref(target_bs);
3113 out:
3114     aio_context_release(aio_context);
3115 }
3116 
3117 void qmp_blockdev_mirror(const char *job_id,
3118                          const char *device, const char *target,
3119                          const char *replaces,
3120                          MirrorSyncMode sync,
3121                          bool has_speed, int64_t speed,
3122                          bool has_granularity, uint32_t granularity,
3123                          bool has_buf_size, int64_t buf_size,
3124                          bool has_on_source_error,
3125                          BlockdevOnError on_source_error,
3126                          bool has_on_target_error,
3127                          BlockdevOnError on_target_error,
3128                          const char *filter_node_name,
3129                          bool has_copy_mode, MirrorCopyMode copy_mode,
3130                          bool has_auto_finalize, bool auto_finalize,
3131                          bool has_auto_dismiss, bool auto_dismiss,
3132                          Error **errp)
3133 {
3134     BlockDriverState *bs;
3135     BlockDriverState *target_bs;
3136     AioContext *aio_context;
3137     AioContext *old_context;
3138     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;
3139     bool zero_target;
3140     int ret;
3141 
3142     bs = qmp_get_root_bs(device, errp);
3143     if (!bs) {
3144         return;
3145     }
3146 
3147     target_bs = bdrv_lookup_bs(target, target, errp);
3148     if (!target_bs) {
3149         return;
3150     }
3151 
3152     zero_target = (sync == MIRROR_SYNC_MODE_FULL);
3153 
3154     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3155     old_context = bdrv_get_aio_context(target_bs);
3156     aio_context = bdrv_get_aio_context(bs);
3157     aio_context_acquire(old_context);
3158 
3159     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3160 
3161     aio_context_release(old_context);
3162     aio_context_acquire(aio_context);
3163 
3164     if (ret < 0) {
3165         goto out;
3166     }
3167 
3168     blockdev_mirror_common(job_id, bs, target_bs,
3169                            replaces, sync, backing_mode,
3170                            zero_target, has_speed, speed,
3171                            has_granularity, granularity,
3172                            has_buf_size, buf_size,
3173                            has_on_source_error, on_source_error,
3174                            has_on_target_error, on_target_error,
3175                            true, true, filter_node_name,
3176                            has_copy_mode, copy_mode,
3177                            has_auto_finalize, auto_finalize,
3178                            has_auto_dismiss, auto_dismiss,
3179                            errp);
3180 out:
3181     aio_context_release(aio_context);
3182 }
3183 
3184 /*
3185  * Get a block job using its ID. Called with job_mutex held.
3186  */
3187 static BlockJob *find_block_job_locked(const char *id, Error **errp)
3188 {
3189     BlockJob *job;
3190 
3191     assert(id != NULL);
3192 
3193     job = block_job_get_locked(id);
3194 
3195     if (!job) {
3196         error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
3197                   "Block job '%s' not found", id);
3198         return NULL;
3199     }
3200 
3201     return job;
3202 }
3203 
3204 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
3205 {
3206     BlockJob *job;
3207 
3208     JOB_LOCK_GUARD();
3209     job = find_block_job_locked(device, errp);
3210 
3211     if (!job) {
3212         return;
3213     }
3214 
3215     block_job_set_speed_locked(job, speed, errp);
3216 }
3217 
3218 void qmp_block_job_cancel(const char *device,
3219                           bool has_force, bool force, Error **errp)
3220 {
3221     BlockJob *job;
3222 
3223     JOB_LOCK_GUARD();
3224     job = find_block_job_locked(device, errp);
3225 
3226     if (!job) {
3227         return;
3228     }
3229 
3230     if (!has_force) {
3231         force = false;
3232     }
3233 
3234     if (job_user_paused_locked(&job->job) && !force) {
3235         error_setg(errp, "The block job for device '%s' is currently paused",
3236                    device);
3237         return;
3238     }
3239 
3240     trace_qmp_block_job_cancel(job);
3241     job_user_cancel_locked(&job->job, force, errp);
3242 }
3243 
3244 void qmp_block_job_pause(const char *device, Error **errp)
3245 {
3246     BlockJob *job;
3247 
3248     JOB_LOCK_GUARD();
3249     job = find_block_job_locked(device, errp);
3250 
3251     if (!job) {
3252         return;
3253     }
3254 
3255     trace_qmp_block_job_pause(job);
3256     job_user_pause_locked(&job->job, errp);
3257 }
3258 
3259 void qmp_block_job_resume(const char *device, Error **errp)
3260 {
3261     BlockJob *job;
3262 
3263     JOB_LOCK_GUARD();
3264     job = find_block_job_locked(device, errp);
3265 
3266     if (!job) {
3267         return;
3268     }
3269 
3270     trace_qmp_block_job_resume(job);
3271     job_user_resume_locked(&job->job, errp);
3272 }
3273 
3274 void qmp_block_job_complete(const char *device, Error **errp)
3275 {
3276     BlockJob *job;
3277 
3278     JOB_LOCK_GUARD();
3279     job = find_block_job_locked(device, errp);
3280 
3281     if (!job) {
3282         return;
3283     }
3284 
3285     trace_qmp_block_job_complete(job);
3286     job_complete_locked(&job->job, errp);
3287 }
3288 
3289 void qmp_block_job_finalize(const char *id, Error **errp)
3290 {
3291     BlockJob *job;
3292 
3293     JOB_LOCK_GUARD();
3294     job = find_block_job_locked(id, errp);
3295 
3296     if (!job) {
3297         return;
3298     }
3299 
3300     trace_qmp_block_job_finalize(job);
3301     job_ref_locked(&job->job);
3302     job_finalize_locked(&job->job, errp);
3303 
3304     job_unref_locked(&job->job);
3305 }
3306 
3307 void qmp_block_job_dismiss(const char *id, Error **errp)
3308 {
3309     BlockJob *bjob;
3310     Job *job;
3311 
3312     JOB_LOCK_GUARD();
3313     bjob = find_block_job_locked(id, errp);
3314 
3315     if (!bjob) {
3316         return;
3317     }
3318 
3319     trace_qmp_block_job_dismiss(bjob);
3320     job = &bjob->job;
3321     job_dismiss_locked(&job, errp);
3322 }
3323 
3324 void qmp_change_backing_file(const char *device,
3325                              const char *image_node_name,
3326                              const char *backing_file,
3327                              Error **errp)
3328 {
3329     BlockDriverState *bs = NULL;
3330     AioContext *aio_context;
3331     BlockDriverState *image_bs = NULL;
3332     Error *local_err = NULL;
3333     bool ro;
3334     int ret;
3335 
3336     bs = qmp_get_root_bs(device, errp);
3337     if (!bs) {
3338         return;
3339     }
3340 
3341     aio_context = bdrv_get_aio_context(bs);
3342     aio_context_acquire(aio_context);
3343 
3344     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
3345     if (local_err) {
3346         error_propagate(errp, local_err);
3347         goto out;
3348     }
3349 
3350     if (!image_bs) {
3351         error_setg(errp, "image file not found");
3352         goto out;
3353     }
3354 
3355     if (bdrv_find_base(image_bs) == image_bs) {
3356         error_setg(errp, "not allowing backing file change on an image "
3357                          "without a backing file");
3358         goto out;
3359     }
3360 
3361     /* even though we are not necessarily operating on bs, we need it to
3362      * determine if block ops are currently prohibited on the chain */
3363     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
3364         goto out;
3365     }
3366 
3367     /* final sanity check */
3368     if (!bdrv_chain_contains(bs, image_bs)) {
3369         error_setg(errp, "'%s' and image file are not in the same chain",
3370                    device);
3371         goto out;
3372     }
3373 
3374     /* if not r/w, reopen to make r/w */
3375     ro = bdrv_is_read_only(image_bs);
3376 
3377     if (ro) {
3378         if (bdrv_reopen_set_read_only(image_bs, false, errp) != 0) {
3379             goto out;
3380         }
3381     }
3382 
3383     ret = bdrv_change_backing_file(image_bs, backing_file,
3384                                    image_bs->drv ? image_bs->drv->format_name : "",
3385                                    false);
3386 
3387     if (ret < 0) {
3388         error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
3389                          backing_file);
3390         /* don't exit here, so we can try to restore open flags if
3391          * appropriate */
3392     }
3393 
3394     if (ro) {
3395         bdrv_reopen_set_read_only(image_bs, true, errp);
3396     }
3397 
3398 out:
3399     aio_context_release(aio_context);
3400 }
3401 
3402 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
3403 {
3404     BlockDriverState *bs;
3405     QObject *obj;
3406     Visitor *v = qobject_output_visitor_new(&obj);
3407     QDict *qdict;
3408 
3409     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3410     visit_complete(v, &obj);
3411     qdict = qobject_to(QDict, obj);
3412 
3413     qdict_flatten(qdict);
3414 
3415     if (!qdict_get_try_str(qdict, "node-name")) {
3416         error_setg(errp, "'node-name' must be specified for the root node");
3417         goto fail;
3418     }
3419 
3420     bs = bds_tree_init(qdict, errp);
3421     if (!bs) {
3422         goto fail;
3423     }
3424 
3425     bdrv_set_monitor_owned(bs);
3426 
3427 fail:
3428     visit_free(v);
3429 }
3430 
3431 void qmp_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
3432 {
3433     BlockReopenQueue *queue = NULL;
3434 
3435     /* Add each one of the BDS that we want to reopen to the queue */
3436     for (; reopen_list != NULL; reopen_list = reopen_list->next) {
3437         BlockdevOptions *options = reopen_list->value;
3438         BlockDriverState *bs;
3439         AioContext *ctx;
3440         QObject *obj;
3441         Visitor *v;
3442         QDict *qdict;
3443 
3444         /* Check for the selected node name */
3445         if (!options->node_name) {
3446             error_setg(errp, "node-name not specified");
3447             goto fail;
3448         }
3449 
3450         bs = bdrv_find_node(options->node_name);
3451         if (!bs) {
3452             error_setg(errp, "Failed to find node with node-name='%s'",
3453                        options->node_name);
3454             goto fail;
3455         }
3456 
3457         /* Put all options in a QDict and flatten it */
3458         v = qobject_output_visitor_new(&obj);
3459         visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3460         visit_complete(v, &obj);
3461         visit_free(v);
3462 
3463         qdict = qobject_to(QDict, obj);
3464 
3465         qdict_flatten(qdict);
3466 
3467         ctx = bdrv_get_aio_context(bs);
3468         aio_context_acquire(ctx);
3469 
3470         queue = bdrv_reopen_queue(queue, bs, qdict, false);
3471 
3472         aio_context_release(ctx);
3473     }
3474 
3475     /* Perform the reopen operation */
3476     bdrv_reopen_multiple(queue, errp);
3477     queue = NULL;
3478 
3479 fail:
3480     bdrv_reopen_queue_free(queue);
3481 }
3482 
3483 void qmp_blockdev_del(const char *node_name, Error **errp)
3484 {
3485     AioContext *aio_context;
3486     BlockDriverState *bs;
3487 
3488     GLOBAL_STATE_CODE();
3489 
3490     bs = bdrv_find_node(node_name);
3491     if (!bs) {
3492         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3493         return;
3494     }
3495     if (bdrv_has_blk(bs)) {
3496         error_setg(errp, "Node %s is in use", node_name);
3497         return;
3498     }
3499     aio_context = bdrv_get_aio_context(bs);
3500     aio_context_acquire(aio_context);
3501 
3502     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
3503         goto out;
3504     }
3505 
3506     if (!QTAILQ_IN_USE(bs, monitor_list)) {
3507         error_setg(errp, "Node %s is not owned by the monitor",
3508                    bs->node_name);
3509         goto out;
3510     }
3511 
3512     if (bs->refcnt > 1) {
3513         error_setg(errp, "Block device %s is in use",
3514                    bdrv_get_device_or_node_name(bs));
3515         goto out;
3516     }
3517 
3518     QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
3519     bdrv_unref(bs);
3520 
3521 out:
3522     aio_context_release(aio_context);
3523 }
3524 
3525 static BdrvChild *bdrv_find_child(BlockDriverState *parent_bs,
3526                                   const char *child_name)
3527 {
3528     BdrvChild *child;
3529 
3530     QLIST_FOREACH(child, &parent_bs->children, next) {
3531         if (strcmp(child->name, child_name) == 0) {
3532             return child;
3533         }
3534     }
3535 
3536     return NULL;
3537 }
3538 
3539 void qmp_x_blockdev_change(const char *parent, const char *child,
3540                            const char *node, Error **errp)
3541 {
3542     BlockDriverState *parent_bs, *new_bs = NULL;
3543     BdrvChild *p_child;
3544 
3545     parent_bs = bdrv_lookup_bs(parent, parent, errp);
3546     if (!parent_bs) {
3547         return;
3548     }
3549 
3550     if (!child == !node) {
3551         if (child) {
3552             error_setg(errp, "The parameters child and node are in conflict");
3553         } else {
3554             error_setg(errp, "Either child or node must be specified");
3555         }
3556         return;
3557     }
3558 
3559     if (child) {
3560         p_child = bdrv_find_child(parent_bs, child);
3561         if (!p_child) {
3562             error_setg(errp, "Node '%s' does not have child '%s'",
3563                        parent, child);
3564             return;
3565         }
3566         bdrv_del_child(parent_bs, p_child, errp);
3567     }
3568 
3569     if (node) {
3570         new_bs = bdrv_find_node(node);
3571         if (!new_bs) {
3572             error_setg(errp, "Node '%s' not found", node);
3573             return;
3574         }
3575         bdrv_add_child(parent_bs, new_bs, errp);
3576     }
3577 }
3578 
3579 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
3580 {
3581     BlockJobInfoList *head = NULL, **tail = &head;
3582     BlockJob *job;
3583 
3584     JOB_LOCK_GUARD();
3585 
3586     for (job = block_job_next_locked(NULL); job;
3587          job = block_job_next_locked(job)) {
3588         BlockJobInfo *value;
3589 
3590         if (block_job_is_internal(job)) {
3591             continue;
3592         }
3593         value = block_job_query_locked(job, errp);
3594         if (!value) {
3595             qapi_free_BlockJobInfoList(head);
3596             return NULL;
3597         }
3598         QAPI_LIST_APPEND(tail, value);
3599     }
3600 
3601     return head;
3602 }
3603 
3604 void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
3605                                  bool has_force, bool force, Error **errp)
3606 {
3607     AioContext *old_context;
3608     AioContext *new_context;
3609     BlockDriverState *bs;
3610 
3611     bs = bdrv_find_node(node_name);
3612     if (!bs) {
3613         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3614         return;
3615     }
3616 
3617     /* Protects against accidents. */
3618     if (!(has_force && force) && bdrv_has_blk(bs)) {
3619         error_setg(errp, "Node %s is associated with a BlockBackend and could "
3620                          "be in use (use force=true to override this check)",
3621                          node_name);
3622         return;
3623     }
3624 
3625     if (iothread->type == QTYPE_QSTRING) {
3626         IOThread *obj = iothread_by_id(iothread->u.s);
3627         if (!obj) {
3628             error_setg(errp, "Cannot find iothread %s", iothread->u.s);
3629             return;
3630         }
3631 
3632         new_context = iothread_get_aio_context(obj);
3633     } else {
3634         new_context = qemu_get_aio_context();
3635     }
3636 
3637     old_context = bdrv_get_aio_context(bs);
3638     aio_context_acquire(old_context);
3639 
3640     bdrv_try_change_aio_context(bs, new_context, NULL, errp);
3641 
3642     aio_context_release(old_context);
3643 }
3644 
3645 QemuOptsList qemu_common_drive_opts = {
3646     .name = "drive",
3647     .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
3648     .desc = {
3649         {
3650             .name = "snapshot",
3651             .type = QEMU_OPT_BOOL,
3652             .help = "enable/disable snapshot mode",
3653         },{
3654             .name = "aio",
3655             .type = QEMU_OPT_STRING,
3656             .help = "host AIO implementation (threads, native, io_uring)",
3657         },{
3658             .name = BDRV_OPT_CACHE_WB,
3659             .type = QEMU_OPT_BOOL,
3660             .help = "Enable writeback mode",
3661         },{
3662             .name = "format",
3663             .type = QEMU_OPT_STRING,
3664             .help = "disk format (raw, qcow2, ...)",
3665         },{
3666             .name = "rerror",
3667             .type = QEMU_OPT_STRING,
3668             .help = "read error action",
3669         },{
3670             .name = "werror",
3671             .type = QEMU_OPT_STRING,
3672             .help = "write error action",
3673         },{
3674             .name = BDRV_OPT_READ_ONLY,
3675             .type = QEMU_OPT_BOOL,
3676             .help = "open drive file as read-only",
3677         },
3678 
3679         THROTTLE_OPTS,
3680 
3681         {
3682             .name = "throttling.group",
3683             .type = QEMU_OPT_STRING,
3684             .help = "name of the block throttling group",
3685         },{
3686             .name = "copy-on-read",
3687             .type = QEMU_OPT_BOOL,
3688             .help = "copy read data from backing file into image file",
3689         },{
3690             .name = "detect-zeroes",
3691             .type = QEMU_OPT_STRING,
3692             .help = "try to optimize zero writes (off, on, unmap)",
3693         },{
3694             .name = "stats-account-invalid",
3695             .type = QEMU_OPT_BOOL,
3696             .help = "whether to account for invalid I/O operations "
3697                     "in the statistics",
3698         },{
3699             .name = "stats-account-failed",
3700             .type = QEMU_OPT_BOOL,
3701             .help = "whether to account for failed I/O operations "
3702                     "in the statistics",
3703         },
3704         { /* end of list */ }
3705     },
3706 };
3707 
3708 QemuOptsList qemu_drive_opts = {
3709     .name = "drive",
3710     .head = QTAILQ_HEAD_INITIALIZER(qemu_drive_opts.head),
3711     .desc = {
3712         /*
3713          * no elements => accept any params
3714          * validation will happen later
3715          */
3716         { /* end of list */ }
3717     },
3718 };
3719