xref: /openbmc/qemu/blockdev.c (revision 5a3d2c35)
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             uint64_t length;
345             const char *str = qstring_get_str(qobject_to(QString,
346                                                          entry->value));
347             if (parse_uint_full(str, 10, &length) == 0 &&
348                 length > 0 && length <= UINT_MAX) {
349                 block_acct_add_interval(stats, (unsigned) length);
350             } else {
351                 error_setg(errp, "Invalid interval length: %s", str);
352                 return false;
353             }
354             break;
355         }
356 
357         case QTYPE_QNUM: {
358             int64_t length = qnum_get_int(qobject_to(QNum, entry->value));
359 
360             if (length > 0 && length <= UINT_MAX) {
361                 block_acct_add_interval(stats, (unsigned) length);
362             } else {
363                 error_setg(errp, "Invalid interval length: %" PRId64, length);
364                 return false;
365             }
366             break;
367         }
368 
369         default:
370             error_setg(errp, "The specification of stats-intervals is invalid");
371             return false;
372         }
373     }
374     return true;
375 }
376 
377 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
378 
379 /* All parameters but @opts are optional and may be set to NULL. */
380 static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
381     const char **throttling_group, ThrottleConfig *throttle_cfg,
382     BlockdevDetectZeroesOptions *detect_zeroes, Error **errp)
383 {
384     Error *local_error = NULL;
385     const char *aio;
386 
387     if (bdrv_flags) {
388         if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
389             *bdrv_flags |= BDRV_O_COPY_ON_READ;
390         }
391 
392         if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
393             if (bdrv_parse_aio(aio, bdrv_flags) < 0) {
394                 error_setg(errp, "invalid aio option");
395                 return;
396             }
397         }
398     }
399 
400     /* disk I/O throttling */
401     if (throttling_group) {
402         *throttling_group = qemu_opt_get(opts, "throttling.group");
403     }
404 
405     if (throttle_cfg) {
406         throttle_config_init(throttle_cfg);
407         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
408             qemu_opt_get_number(opts, "throttling.bps-total", 0);
409         throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
410             qemu_opt_get_number(opts, "throttling.bps-read", 0);
411         throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
412             qemu_opt_get_number(opts, "throttling.bps-write", 0);
413         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
414             qemu_opt_get_number(opts, "throttling.iops-total", 0);
415         throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
416             qemu_opt_get_number(opts, "throttling.iops-read", 0);
417         throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
418             qemu_opt_get_number(opts, "throttling.iops-write", 0);
419 
420         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
421             qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
422         throttle_cfg->buckets[THROTTLE_BPS_READ].max  =
423             qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
424         throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
425             qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
426         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
427             qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
428         throttle_cfg->buckets[THROTTLE_OPS_READ].max =
429             qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
430         throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
431             qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
432 
433         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].burst_length =
434             qemu_opt_get_number(opts, "throttling.bps-total-max-length", 1);
435         throttle_cfg->buckets[THROTTLE_BPS_READ].burst_length  =
436             qemu_opt_get_number(opts, "throttling.bps-read-max-length", 1);
437         throttle_cfg->buckets[THROTTLE_BPS_WRITE].burst_length =
438             qemu_opt_get_number(opts, "throttling.bps-write-max-length", 1);
439         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].burst_length =
440             qemu_opt_get_number(opts, "throttling.iops-total-max-length", 1);
441         throttle_cfg->buckets[THROTTLE_OPS_READ].burst_length =
442             qemu_opt_get_number(opts, "throttling.iops-read-max-length", 1);
443         throttle_cfg->buckets[THROTTLE_OPS_WRITE].burst_length =
444             qemu_opt_get_number(opts, "throttling.iops-write-max-length", 1);
445 
446         throttle_cfg->op_size =
447             qemu_opt_get_number(opts, "throttling.iops-size", 0);
448 
449         if (!throttle_is_valid(throttle_cfg, errp)) {
450             return;
451         }
452     }
453 
454     if (detect_zeroes) {
455         *detect_zeroes =
456             qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
457                             qemu_opt_get(opts, "detect-zeroes"),
458                             BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
459                             &local_error);
460         if (local_error) {
461             error_propagate(errp, local_error);
462             return;
463         }
464     }
465 }
466 
467 static OnOffAuto account_get_opt(QemuOpts *opts, const char *name)
468 {
469     if (!qemu_opt_find(opts, name)) {
470         return ON_OFF_AUTO_AUTO;
471     }
472     if (qemu_opt_get_bool(opts, name, true)) {
473         return ON_OFF_AUTO_ON;
474     }
475     return ON_OFF_AUTO_OFF;
476 }
477 
478 /* Takes the ownership of bs_opts */
479 static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
480                                    Error **errp)
481 {
482     const char *buf;
483     int bdrv_flags = 0;
484     int on_read_error, on_write_error;
485     OnOffAuto account_invalid, account_failed;
486     bool writethrough, read_only;
487     BlockBackend *blk;
488     BlockDriverState *bs;
489     ThrottleConfig cfg;
490     int snapshot = 0;
491     Error *error = NULL;
492     QemuOpts *opts;
493     QDict *interval_dict = NULL;
494     QList *interval_list = NULL;
495     const char *id;
496     BlockdevDetectZeroesOptions detect_zeroes =
497         BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
498     const char *throttling_group = NULL;
499 
500     /* Check common options by copying from bs_opts to opts, all other options
501      * stay in bs_opts for processing by bdrv_open(). */
502     id = qdict_get_try_str(bs_opts, "id");
503     opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, errp);
504     if (!opts) {
505         goto err_no_opts;
506     }
507 
508     if (!qemu_opts_absorb_qdict(opts, bs_opts, errp)) {
509         goto early_err;
510     }
511 
512     if (id) {
513         qdict_del(bs_opts, "id");
514     }
515 
516     /* extract parameters */
517     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
518 
519     account_invalid = account_get_opt(opts, "stats-account-invalid");
520     account_failed = account_get_opt(opts, "stats-account-failed");
521 
522     writethrough = !qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true);
523 
524     id = qemu_opts_id(opts);
525 
526     qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals.");
527     qdict_array_split(interval_dict, &interval_list);
528 
529     if (qdict_size(interval_dict) != 0) {
530         error_setg(errp, "Invalid option stats-intervals.%s",
531                    qdict_first(interval_dict)->key);
532         goto early_err;
533     }
534 
535     extract_common_blockdev_options(opts, &bdrv_flags, &throttling_group, &cfg,
536                                     &detect_zeroes, &error);
537     if (error) {
538         error_propagate(errp, error);
539         goto early_err;
540     }
541 
542     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
543         if (is_help_option(buf)) {
544             qemu_printf("Supported formats:");
545             bdrv_iterate_format(bdrv_format_print, NULL, false);
546             qemu_printf("\nSupported formats (read-only):");
547             bdrv_iterate_format(bdrv_format_print, NULL, true);
548             qemu_printf("\n");
549             goto early_err;
550         }
551 
552         if (qdict_haskey(bs_opts, "driver")) {
553             error_setg(errp, "Cannot specify both 'driver' and 'format'");
554             goto early_err;
555         }
556         qdict_put_str(bs_opts, "driver", buf);
557     }
558 
559     on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
560     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
561         on_write_error = parse_block_error_action(buf, 0, &error);
562         if (error) {
563             error_propagate(errp, error);
564             goto early_err;
565         }
566     }
567 
568     on_read_error = BLOCKDEV_ON_ERROR_REPORT;
569     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
570         on_read_error = parse_block_error_action(buf, 1, &error);
571         if (error) {
572             error_propagate(errp, error);
573             goto early_err;
574         }
575     }
576 
577     if (snapshot) {
578         bdrv_flags |= BDRV_O_SNAPSHOT;
579     }
580 
581     read_only = qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false);
582 
583     /* init */
584     if ((!file || !*file) && !qdict_size(bs_opts)) {
585         BlockBackendRootState *blk_rs;
586 
587         blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
588         blk_rs = blk_get_root_state(blk);
589         blk_rs->open_flags    = bdrv_flags | (read_only ? 0 : BDRV_O_RDWR);
590         blk_rs->detect_zeroes = detect_zeroes;
591 
592         qobject_unref(bs_opts);
593     } else {
594         if (file && !*file) {
595             file = NULL;
596         }
597 
598         /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
599          * with other callers) rather than what we want as the real defaults.
600          * Apply the defaults here instead. */
601         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
602         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
603         qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY,
604                               read_only ? "on" : "off");
605         qdict_set_default_str(bs_opts, BDRV_OPT_AUTO_READ_ONLY, "on");
606         assert((bdrv_flags & BDRV_O_CACHE_MASK) == 0);
607 
608         if (runstate_check(RUN_STATE_INMIGRATE)) {
609             bdrv_flags |= BDRV_O_INACTIVE;
610         }
611 
612         blk = blk_new_open(file, NULL, bs_opts, bdrv_flags, errp);
613         if (!blk) {
614             goto err_no_bs_opts;
615         }
616         bs = blk_bs(blk);
617 
618         bs->detect_zeroes = detect_zeroes;
619 
620         block_acct_setup(blk_get_stats(blk), account_invalid, account_failed);
621 
622         if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
623             blk_unref(blk);
624             blk = NULL;
625             goto err_no_bs_opts;
626         }
627     }
628 
629     /* disk I/O throttling */
630     if (throttle_enabled(&cfg)) {
631         if (!throttling_group) {
632             throttling_group = id;
633         }
634         blk_io_limits_enable(blk, throttling_group);
635         blk_set_io_limits(blk, &cfg);
636     }
637 
638     blk_set_enable_write_cache(blk, !writethrough);
639     blk_set_on_error(blk, on_read_error, on_write_error);
640 
641     if (!monitor_add_blk(blk, id, errp)) {
642         blk_unref(blk);
643         blk = NULL;
644         goto err_no_bs_opts;
645     }
646 
647 err_no_bs_opts:
648     qemu_opts_del(opts);
649     qobject_unref(interval_dict);
650     qobject_unref(interval_list);
651     return blk;
652 
653 early_err:
654     qemu_opts_del(opts);
655     qobject_unref(interval_dict);
656     qobject_unref(interval_list);
657 err_no_opts:
658     qobject_unref(bs_opts);
659     return NULL;
660 }
661 
662 /* Takes the ownership of bs_opts */
663 BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
664 {
665     BlockDriverState *bs;
666     int bdrv_flags = 0;
667 
668     GLOBAL_STATE_CODE();
669     /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
670      * with other callers) rather than what we want as the real defaults.
671      * Apply the defaults here instead. */
672     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
673     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
674     qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY, "off");
675 
676     if (runstate_check(RUN_STATE_INMIGRATE)) {
677         bdrv_flags |= BDRV_O_INACTIVE;
678     }
679 
680     aio_context_acquire(qemu_get_aio_context());
681     bs = bdrv_open(NULL, NULL, bs_opts, bdrv_flags, errp);
682     aio_context_release(qemu_get_aio_context());
683 
684     return bs;
685 }
686 
687 void blockdev_close_all_bdrv_states(void)
688 {
689     BlockDriverState *bs, *next_bs;
690 
691     GLOBAL_STATE_CODE();
692     QTAILQ_FOREACH_SAFE(bs, &monitor_bdrv_states, monitor_list, next_bs) {
693         AioContext *ctx = bdrv_get_aio_context(bs);
694 
695         aio_context_acquire(ctx);
696         bdrv_unref(bs);
697         aio_context_release(ctx);
698     }
699 }
700 
701 /* Iterates over the list of monitor-owned BlockDriverStates */
702 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs)
703 {
704     GLOBAL_STATE_CODE();
705     return bs ? QTAILQ_NEXT(bs, monitor_list)
706               : QTAILQ_FIRST(&monitor_bdrv_states);
707 }
708 
709 static bool qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
710                             Error **errp)
711 {
712     const char *value;
713 
714     value = qemu_opt_get(opts, from);
715     if (value) {
716         if (qemu_opt_find(opts, to)) {
717             error_setg(errp, "'%s' and its alias '%s' can't be used at the "
718                        "same time", to, from);
719             return false;
720         }
721     }
722 
723     /* rename all items in opts */
724     while ((value = qemu_opt_get(opts, from))) {
725         qemu_opt_set(opts, to, value, &error_abort);
726         qemu_opt_unset(opts, from);
727     }
728     return true;
729 }
730 
731 QemuOptsList qemu_legacy_drive_opts = {
732     .name = "drive",
733     .head = QTAILQ_HEAD_INITIALIZER(qemu_legacy_drive_opts.head),
734     .desc = {
735         {
736             .name = "bus",
737             .type = QEMU_OPT_NUMBER,
738             .help = "bus number",
739         },{
740             .name = "unit",
741             .type = QEMU_OPT_NUMBER,
742             .help = "unit number (i.e. lun for scsi)",
743         },{
744             .name = "index",
745             .type = QEMU_OPT_NUMBER,
746             .help = "index number",
747         },{
748             .name = "media",
749             .type = QEMU_OPT_STRING,
750             .help = "media type (disk, cdrom)",
751         },{
752             .name = "if",
753             .type = QEMU_OPT_STRING,
754             .help = "interface (ide, scsi, sd, mtd, floppy, pflash, virtio)",
755         },{
756             .name = "file",
757             .type = QEMU_OPT_STRING,
758             .help = "file name",
759         },
760 
761         /* Options that are passed on, but have special semantics with -drive */
762         {
763             .name = BDRV_OPT_READ_ONLY,
764             .type = QEMU_OPT_BOOL,
765             .help = "open drive file as read-only",
766         },{
767             .name = "rerror",
768             .type = QEMU_OPT_STRING,
769             .help = "read error action",
770         },{
771             .name = "werror",
772             .type = QEMU_OPT_STRING,
773             .help = "write error action",
774         },{
775             .name = "copy-on-read",
776             .type = QEMU_OPT_BOOL,
777             .help = "copy read data from backing file into image file",
778         },
779 
780         { /* end of list */ }
781     },
782 };
783 
784 DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type,
785                      Error **errp)
786 {
787     const char *value;
788     BlockBackend *blk;
789     DriveInfo *dinfo = NULL;
790     QDict *bs_opts;
791     QemuOpts *legacy_opts;
792     DriveMediaType media = MEDIA_DISK;
793     BlockInterfaceType type;
794     int max_devs, bus_id, unit_id, index;
795     const char *werror, *rerror;
796     bool read_only = false;
797     bool copy_on_read;
798     const char *filename;
799     int i;
800 
801     GLOBAL_STATE_CODE();
802 
803     /* Change legacy command line options into QMP ones */
804     static const struct {
805         const char *from;
806         const char *to;
807     } opt_renames[] = {
808         { "iops",           "throttling.iops-total" },
809         { "iops_rd",        "throttling.iops-read" },
810         { "iops_wr",        "throttling.iops-write" },
811 
812         { "bps",            "throttling.bps-total" },
813         { "bps_rd",         "throttling.bps-read" },
814         { "bps_wr",         "throttling.bps-write" },
815 
816         { "iops_max",       "throttling.iops-total-max" },
817         { "iops_rd_max",    "throttling.iops-read-max" },
818         { "iops_wr_max",    "throttling.iops-write-max" },
819 
820         { "bps_max",        "throttling.bps-total-max" },
821         { "bps_rd_max",     "throttling.bps-read-max" },
822         { "bps_wr_max",     "throttling.bps-write-max" },
823 
824         { "iops_size",      "throttling.iops-size" },
825 
826         { "group",          "throttling.group" },
827 
828         { "readonly",       BDRV_OPT_READ_ONLY },
829     };
830 
831     for (i = 0; i < ARRAY_SIZE(opt_renames); i++) {
832         if (!qemu_opt_rename(all_opts, opt_renames[i].from,
833                              opt_renames[i].to, errp)) {
834             return NULL;
835         }
836     }
837 
838     value = qemu_opt_get(all_opts, "cache");
839     if (value) {
840         int flags = 0;
841         bool writethrough;
842 
843         if (bdrv_parse_cache_mode(value, &flags, &writethrough) != 0) {
844             error_setg(errp, "invalid cache option");
845             return NULL;
846         }
847 
848         /* Specific options take precedence */
849         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_WB)) {
850             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_WB,
851                               !writethrough, &error_abort);
852         }
853         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_DIRECT)) {
854             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_DIRECT,
855                               !!(flags & BDRV_O_NOCACHE), &error_abort);
856         }
857         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_NO_FLUSH)) {
858             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_NO_FLUSH,
859                               !!(flags & BDRV_O_NO_FLUSH), &error_abort);
860         }
861         qemu_opt_unset(all_opts, "cache");
862     }
863 
864     /* Get a QDict for processing the options */
865     bs_opts = qdict_new();
866     qemu_opts_to_qdict(all_opts, bs_opts);
867 
868     legacy_opts = qemu_opts_create(&qemu_legacy_drive_opts, NULL, 0,
869                                    &error_abort);
870     if (!qemu_opts_absorb_qdict(legacy_opts, bs_opts, errp)) {
871         goto fail;
872     }
873 
874     /* Media type */
875     value = qemu_opt_get(legacy_opts, "media");
876     if (value) {
877         if (!strcmp(value, "disk")) {
878             media = MEDIA_DISK;
879         } else if (!strcmp(value, "cdrom")) {
880             media = MEDIA_CDROM;
881             read_only = true;
882         } else {
883             error_setg(errp, "'%s' invalid media", value);
884             goto fail;
885         }
886     }
887 
888     /* copy-on-read is disabled with a warning for read-only devices */
889     read_only |= qemu_opt_get_bool(legacy_opts, BDRV_OPT_READ_ONLY, false);
890     copy_on_read = qemu_opt_get_bool(legacy_opts, "copy-on-read", false);
891 
892     if (read_only && copy_on_read) {
893         warn_report("disabling copy-on-read on read-only drive");
894         copy_on_read = false;
895     }
896 
897     qdict_put_str(bs_opts, BDRV_OPT_READ_ONLY, read_only ? "on" : "off");
898     qdict_put_str(bs_opts, "copy-on-read", copy_on_read ? "on" : "off");
899 
900     /* Controller type */
901     value = qemu_opt_get(legacy_opts, "if");
902     if (value) {
903         for (type = 0;
904              type < IF_COUNT && strcmp(value, if_name[type]);
905              type++) {
906         }
907         if (type == IF_COUNT) {
908             error_setg(errp, "unsupported bus type '%s'", value);
909             goto fail;
910         }
911     } else {
912         type = block_default_type;
913     }
914 
915     /* Device address specified by bus/unit or index.
916      * If none was specified, try to find the first free one. */
917     bus_id  = qemu_opt_get_number(legacy_opts, "bus", 0);
918     unit_id = qemu_opt_get_number(legacy_opts, "unit", -1);
919     index   = qemu_opt_get_number(legacy_opts, "index", -1);
920 
921     max_devs = if_max_devs[type];
922 
923     if (index != -1) {
924         if (bus_id != 0 || unit_id != -1) {
925             error_setg(errp, "index cannot be used with bus and unit");
926             goto fail;
927         }
928         bus_id = drive_index_to_bus_id(type, index);
929         unit_id = drive_index_to_unit_id(type, index);
930     }
931 
932     if (unit_id == -1) {
933        unit_id = 0;
934        while (drive_get(type, bus_id, unit_id) != NULL) {
935            unit_id++;
936            if (max_devs && unit_id >= max_devs) {
937                unit_id -= max_devs;
938                bus_id++;
939            }
940        }
941     }
942 
943     if (max_devs && unit_id >= max_devs) {
944         error_setg(errp, "unit %d too big (max is %d)", unit_id, max_devs - 1);
945         goto fail;
946     }
947 
948     if (drive_get(type, bus_id, unit_id) != NULL) {
949         error_setg(errp, "drive with bus=%d, unit=%d (index=%d) exists",
950                    bus_id, unit_id, index);
951         goto fail;
952     }
953 
954     /* no id supplied -> create one */
955     if (qemu_opts_id(all_opts) == NULL) {
956         char *new_id;
957         const char *mediastr = "";
958         if (type == IF_IDE || type == IF_SCSI) {
959             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
960         }
961         if (max_devs) {
962             new_id = g_strdup_printf("%s%i%s%i", if_name[type], bus_id,
963                                      mediastr, unit_id);
964         } else {
965             new_id = g_strdup_printf("%s%s%i", if_name[type],
966                                      mediastr, unit_id);
967         }
968         qdict_put_str(bs_opts, "id", new_id);
969         g_free(new_id);
970     }
971 
972     /* Add virtio block device */
973     if (type == IF_VIRTIO) {
974         QemuOpts *devopts;
975         devopts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
976                                    &error_abort);
977         qemu_opt_set(devopts, "driver", "virtio-blk", &error_abort);
978         qemu_opt_set(devopts, "drive", qdict_get_str(bs_opts, "id"),
979                      &error_abort);
980     }
981 
982     filename = qemu_opt_get(legacy_opts, "file");
983 
984     /* Check werror/rerror compatibility with if=... */
985     werror = qemu_opt_get(legacy_opts, "werror");
986     if (werror != NULL) {
987         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO &&
988             type != IF_NONE) {
989             error_setg(errp, "werror is not supported by this bus type");
990             goto fail;
991         }
992         qdict_put_str(bs_opts, "werror", werror);
993     }
994 
995     rerror = qemu_opt_get(legacy_opts, "rerror");
996     if (rerror != NULL) {
997         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI &&
998             type != IF_NONE) {
999             error_setg(errp, "rerror is not supported by this bus type");
1000             goto fail;
1001         }
1002         qdict_put_str(bs_opts, "rerror", rerror);
1003     }
1004 
1005     /* Actual block device init: Functionality shared with blockdev-add */
1006     blk = blockdev_init(filename, bs_opts, errp);
1007     bs_opts = NULL;
1008     if (!blk) {
1009         goto fail;
1010     }
1011 
1012     /* Create legacy DriveInfo */
1013     dinfo = g_malloc0(sizeof(*dinfo));
1014     dinfo->opts = all_opts;
1015 
1016     dinfo->type = type;
1017     dinfo->bus = bus_id;
1018     dinfo->unit = unit_id;
1019 
1020     blk_set_legacy_dinfo(blk, dinfo);
1021 
1022     switch(type) {
1023     case IF_IDE:
1024     case IF_SCSI:
1025     case IF_XEN:
1026     case IF_NONE:
1027         dinfo->media_cd = media == MEDIA_CDROM;
1028         break;
1029     default:
1030         break;
1031     }
1032 
1033 fail:
1034     qemu_opts_del(legacy_opts);
1035     qobject_unref(bs_opts);
1036     return dinfo;
1037 }
1038 
1039 static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
1040 {
1041     BlockDriverState *bs;
1042     AioContext *aio_context;
1043 
1044     bs = bdrv_lookup_bs(name, name, errp);
1045     if (bs == NULL) {
1046         return NULL;
1047     }
1048 
1049     if (!bdrv_is_root_node(bs)) {
1050         error_setg(errp, "Need a root block node");
1051         return NULL;
1052     }
1053 
1054     aio_context = bdrv_get_aio_context(bs);
1055     aio_context_acquire(aio_context);
1056 
1057     if (!bdrv_is_inserted(bs)) {
1058         error_setg(errp, "Device has no medium");
1059         bs = NULL;
1060     }
1061 
1062     aio_context_release(aio_context);
1063 
1064     return bs;
1065 }
1066 
1067 static void blockdev_do_action(TransactionAction *action, Error **errp)
1068 {
1069     TransactionActionList list;
1070 
1071     list.value = action;
1072     list.next = NULL;
1073     qmp_transaction(&list, NULL, errp);
1074 }
1075 
1076 void qmp_blockdev_snapshot_sync(const char *device, const char *node_name,
1077                                 const char *snapshot_file,
1078                                 const char *snapshot_node_name,
1079                                 const char *format,
1080                                 bool has_mode, NewImageMode mode, Error **errp)
1081 {
1082     BlockdevSnapshotSync snapshot = {
1083         .device = (char *) device,
1084         .node_name = (char *) node_name,
1085         .snapshot_file = (char *) snapshot_file,
1086         .snapshot_node_name = (char *) snapshot_node_name,
1087         .format = (char *) format,
1088         .has_mode = has_mode,
1089         .mode = mode,
1090     };
1091     TransactionAction action = {
1092         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
1093         .u.blockdev_snapshot_sync.data = &snapshot,
1094     };
1095     blockdev_do_action(&action, errp);
1096 }
1097 
1098 void qmp_blockdev_snapshot(const char *node, const char *overlay,
1099                            Error **errp)
1100 {
1101     BlockdevSnapshot snapshot_data = {
1102         .node = (char *) node,
1103         .overlay = (char *) overlay
1104     };
1105     TransactionAction action = {
1106         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
1107         .u.blockdev_snapshot.data = &snapshot_data,
1108     };
1109     blockdev_do_action(&action, errp);
1110 }
1111 
1112 void qmp_blockdev_snapshot_internal_sync(const char *device,
1113                                          const char *name,
1114                                          Error **errp)
1115 {
1116     BlockdevSnapshotInternal snapshot = {
1117         .device = (char *) device,
1118         .name = (char *) name
1119     };
1120     TransactionAction action = {
1121         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
1122         .u.blockdev_snapshot_internal_sync.data = &snapshot,
1123     };
1124     blockdev_do_action(&action, errp);
1125 }
1126 
1127 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
1128                                                          const char *id,
1129                                                          const char *name,
1130                                                          Error **errp)
1131 {
1132     BlockDriverState *bs;
1133     AioContext *aio_context;
1134     QEMUSnapshotInfo sn;
1135     Error *local_err = NULL;
1136     SnapshotInfo *info = NULL;
1137     int ret;
1138 
1139     bs = qmp_get_root_bs(device, errp);
1140     if (!bs) {
1141         return NULL;
1142     }
1143     aio_context = bdrv_get_aio_context(bs);
1144     aio_context_acquire(aio_context);
1145 
1146     if (!id && !name) {
1147         error_setg(errp, "Name or id must be provided");
1148         goto out_aio_context;
1149     }
1150 
1151     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
1152         goto out_aio_context;
1153     }
1154 
1155     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
1156     if (local_err) {
1157         error_propagate(errp, local_err);
1158         goto out_aio_context;
1159     }
1160     if (!ret) {
1161         error_setg(errp,
1162                    "Snapshot with id '%s' and name '%s' does not exist on "
1163                    "device '%s'",
1164                    STR_OR_NULL(id), STR_OR_NULL(name), device);
1165         goto out_aio_context;
1166     }
1167 
1168     bdrv_snapshot_delete(bs, id, name, &local_err);
1169     if (local_err) {
1170         error_propagate(errp, local_err);
1171         goto out_aio_context;
1172     }
1173 
1174     aio_context_release(aio_context);
1175 
1176     info = g_new0(SnapshotInfo, 1);
1177     info->id = g_strdup(sn.id_str);
1178     info->name = g_strdup(sn.name);
1179     info->date_nsec = sn.date_nsec;
1180     info->date_sec = sn.date_sec;
1181     info->vm_state_size = sn.vm_state_size;
1182     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
1183     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
1184     if (sn.icount != -1ULL) {
1185         info->icount = sn.icount;
1186         info->has_icount = true;
1187     }
1188 
1189     return info;
1190 
1191 out_aio_context:
1192     aio_context_release(aio_context);
1193     return NULL;
1194 }
1195 
1196 /* internal snapshot private data */
1197 typedef struct InternalSnapshotState {
1198     BlockDriverState *bs;
1199     QEMUSnapshotInfo sn;
1200     bool created;
1201 } InternalSnapshotState;
1202 
1203 static void internal_snapshot_abort(void *opaque);
1204 static void internal_snapshot_clean(void *opaque);
1205 TransactionActionDrv internal_snapshot_drv = {
1206     .abort = internal_snapshot_abort,
1207     .clean = internal_snapshot_clean,
1208 };
1209 
1210 static void internal_snapshot_action(BlockdevSnapshotInternal *internal,
1211                                      Transaction *tran, Error **errp)
1212 {
1213     Error *local_err = NULL;
1214     const char *device;
1215     const char *name;
1216     BlockDriverState *bs;
1217     QEMUSnapshotInfo old_sn, *sn;
1218     bool ret;
1219     int64_t rt;
1220     InternalSnapshotState *state = g_new0(InternalSnapshotState, 1);
1221     AioContext *aio_context;
1222     int ret1;
1223 
1224     tran_add(tran, &internal_snapshot_drv, state);
1225 
1226     device = internal->device;
1227     name = internal->name;
1228 
1229     bs = qmp_get_root_bs(device, errp);
1230     if (!bs) {
1231         return;
1232     }
1233 
1234     aio_context = bdrv_get_aio_context(bs);
1235     aio_context_acquire(aio_context);
1236 
1237     state->bs = bs;
1238 
1239     /* Paired with .clean() */
1240     bdrv_drained_begin(bs);
1241 
1242     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
1243         goto out;
1244     }
1245 
1246     if (bdrv_is_read_only(bs)) {
1247         error_setg(errp, "Device '%s' is read only", device);
1248         goto out;
1249     }
1250 
1251     if (!bdrv_can_snapshot(bs)) {
1252         error_setg(errp, "Block format '%s' used by device '%s' "
1253                    "does not support internal snapshots",
1254                    bs->drv->format_name, device);
1255         goto out;
1256     }
1257 
1258     if (!strlen(name)) {
1259         error_setg(errp, "Name is empty");
1260         goto out;
1261     }
1262 
1263     /* check whether a snapshot with name exist */
1264     ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &old_sn,
1265                                             &local_err);
1266     if (local_err) {
1267         error_propagate(errp, local_err);
1268         goto out;
1269     } else if (ret) {
1270         error_setg(errp,
1271                    "Snapshot with name '%s' already exists on device '%s'",
1272                    name, device);
1273         goto out;
1274     }
1275 
1276     /* 3. take the snapshot */
1277     sn = &state->sn;
1278     pstrcpy(sn->name, sizeof(sn->name), name);
1279     rt = g_get_real_time();
1280     sn->date_sec = rt / G_USEC_PER_SEC;
1281     sn->date_nsec = (rt % G_USEC_PER_SEC) * 1000;
1282     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1283     if (replay_mode != REPLAY_MODE_NONE) {
1284         sn->icount = replay_get_current_icount();
1285     } else {
1286         sn->icount = -1ULL;
1287     }
1288 
1289     ret1 = bdrv_snapshot_create(bs, sn);
1290     if (ret1 < 0) {
1291         error_setg_errno(errp, -ret1,
1292                          "Failed to create snapshot '%s' on device '%s'",
1293                          name, device);
1294         goto out;
1295     }
1296 
1297     /* 4. succeed, mark a snapshot is created */
1298     state->created = true;
1299 
1300 out:
1301     aio_context_release(aio_context);
1302 }
1303 
1304 static void internal_snapshot_abort(void *opaque)
1305 {
1306     InternalSnapshotState *state = opaque;
1307     BlockDriverState *bs = state->bs;
1308     QEMUSnapshotInfo *sn = &state->sn;
1309     AioContext *aio_context;
1310     Error *local_error = NULL;
1311 
1312     if (!state->created) {
1313         return;
1314     }
1315 
1316     aio_context = bdrv_get_aio_context(state->bs);
1317     aio_context_acquire(aio_context);
1318 
1319     if (bdrv_snapshot_delete(bs, sn->id_str, sn->name, &local_error) < 0) {
1320         error_reportf_err(local_error,
1321                           "Failed to delete snapshot with id '%s' and "
1322                           "name '%s' on device '%s' in abort: ",
1323                           sn->id_str, sn->name,
1324                           bdrv_get_device_name(bs));
1325     }
1326 
1327     aio_context_release(aio_context);
1328 }
1329 
1330 static void internal_snapshot_clean(void *opaque)
1331 {
1332     g_autofree InternalSnapshotState *state = opaque;
1333     AioContext *aio_context;
1334 
1335     if (!state->bs) {
1336         return;
1337     }
1338 
1339     aio_context = bdrv_get_aio_context(state->bs);
1340     aio_context_acquire(aio_context);
1341 
1342     bdrv_drained_end(state->bs);
1343 
1344     aio_context_release(aio_context);
1345 }
1346 
1347 /* external snapshot private data */
1348 typedef struct ExternalSnapshotState {
1349     BlockDriverState *old_bs;
1350     BlockDriverState *new_bs;
1351     bool overlay_appended;
1352 } ExternalSnapshotState;
1353 
1354 static void external_snapshot_commit(void *opaque);
1355 static void external_snapshot_abort(void *opaque);
1356 static void external_snapshot_clean(void *opaque);
1357 TransactionActionDrv external_snapshot_drv = {
1358     .commit = external_snapshot_commit,
1359     .abort = external_snapshot_abort,
1360     .clean = external_snapshot_clean,
1361 };
1362 
1363 static void external_snapshot_action(TransactionAction *action,
1364                                      Transaction *tran, Error **errp)
1365 {
1366     int ret;
1367     int flags = 0;
1368     QDict *options = NULL;
1369     Error *local_err = NULL;
1370     /* Device and node name of the image to generate the snapshot from */
1371     const char *device;
1372     const char *node_name;
1373     /* Reference to the new image (for 'blockdev-snapshot') */
1374     const char *snapshot_ref;
1375     /* File name of the new image (for 'blockdev-snapshot-sync') */
1376     const char *new_image_file;
1377     ExternalSnapshotState *state = g_new0(ExternalSnapshotState, 1);
1378     AioContext *aio_context;
1379     uint64_t perm, shared;
1380 
1381     /* TODO We'll eventually have to take a writer lock in this function */
1382     GRAPH_RDLOCK_GUARD_MAINLOOP();
1383 
1384     tran_add(tran, &external_snapshot_drv, state);
1385 
1386     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
1387      * purpose but a different set of parameters */
1388     switch (action->type) {
1389     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
1390         {
1391             BlockdevSnapshot *s = action->u.blockdev_snapshot.data;
1392             device = s->node;
1393             node_name = s->node;
1394             new_image_file = NULL;
1395             snapshot_ref = s->overlay;
1396         }
1397         break;
1398     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
1399         {
1400             BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1401             device = s->device;
1402             node_name = s->node_name;
1403             new_image_file = s->snapshot_file;
1404             snapshot_ref = NULL;
1405         }
1406         break;
1407     default:
1408         g_assert_not_reached();
1409     }
1410 
1411     /* start processing */
1412 
1413     state->old_bs = bdrv_lookup_bs(device, node_name, errp);
1414     if (!state->old_bs) {
1415         return;
1416     }
1417 
1418     aio_context = bdrv_get_aio_context(state->old_bs);
1419     aio_context_acquire(aio_context);
1420 
1421     /* Paired with .clean() */
1422     bdrv_drained_begin(state->old_bs);
1423 
1424     if (!bdrv_is_inserted(state->old_bs)) {
1425         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1426         goto out;
1427     }
1428 
1429     if (bdrv_op_is_blocked(state->old_bs,
1430                            BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
1431         goto out;
1432     }
1433 
1434     if (!bdrv_is_read_only(state->old_bs)) {
1435         if (bdrv_flush(state->old_bs)) {
1436             error_setg(errp, QERR_IO_ERROR);
1437             goto out;
1438         }
1439     }
1440 
1441     if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
1442         BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1443         const char *format = s->format ?: "qcow2";
1444         enum NewImageMode mode;
1445         const char *snapshot_node_name = s->snapshot_node_name;
1446 
1447         if (node_name && !snapshot_node_name) {
1448             error_setg(errp, "New overlay node-name missing");
1449             goto out;
1450         }
1451 
1452         if (snapshot_node_name &&
1453             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
1454             error_setg(errp, "New overlay node-name already in use");
1455             goto out;
1456         }
1457 
1458         flags = state->old_bs->open_flags;
1459         flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ);
1460         flags |= BDRV_O_NO_BACKING;
1461 
1462         /* create new image w/backing file */
1463         mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1464         if (mode != NEW_IMAGE_MODE_EXISTING) {
1465             int64_t size = bdrv_getlength(state->old_bs);
1466             if (size < 0) {
1467                 error_setg_errno(errp, -size, "bdrv_getlength failed");
1468                 goto out;
1469             }
1470             bdrv_refresh_filename(state->old_bs);
1471 
1472             aio_context_release(aio_context);
1473             bdrv_img_create(new_image_file, format,
1474                             state->old_bs->filename,
1475                             state->old_bs->drv->format_name,
1476                             NULL, size, flags, false, &local_err);
1477             aio_context_acquire(aio_context);
1478 
1479             if (local_err) {
1480                 error_propagate(errp, local_err);
1481                 goto out;
1482             }
1483         }
1484 
1485         options = qdict_new();
1486         if (snapshot_node_name) {
1487             qdict_put_str(options, "node-name", snapshot_node_name);
1488         }
1489         qdict_put_str(options, "driver", format);
1490     }
1491     aio_context_release(aio_context);
1492 
1493     aio_context_acquire(qemu_get_aio_context());
1494     state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags,
1495                               errp);
1496     aio_context_release(qemu_get_aio_context());
1497 
1498     /* We will manually add the backing_hd field to the bs later */
1499     if (!state->new_bs) {
1500         return;
1501     }
1502 
1503     aio_context_acquire(aio_context);
1504 
1505     /*
1506      * Allow attaching a backing file to an overlay that's already in use only
1507      * if the parents don't assume that they are already seeing a valid image.
1508      * (Specifically, allow it as a mirror target, which is write-only access.)
1509      */
1510     bdrv_get_cumulative_perm(state->new_bs, &perm, &shared);
1511     if (perm & BLK_PERM_CONSISTENT_READ) {
1512         error_setg(errp, "The overlay is already in use");
1513         goto out;
1514     }
1515 
1516     if (state->new_bs->drv->is_filter) {
1517         error_setg(errp, "Filters cannot be used as overlays");
1518         goto out;
1519     }
1520 
1521     if (bdrv_cow_child(state->new_bs)) {
1522         error_setg(errp, "The overlay already has a backing image");
1523         goto out;
1524     }
1525 
1526     if (!state->new_bs->drv->supports_backing) {
1527         error_setg(errp, "The overlay does not support backing images");
1528         goto out;
1529     }
1530 
1531     ret = bdrv_append(state->new_bs, state->old_bs, errp);
1532     if (ret < 0) {
1533         goto out;
1534     }
1535     state->overlay_appended = true;
1536 
1537 out:
1538     aio_context_release(aio_context);
1539 }
1540 
1541 static void external_snapshot_commit(void *opaque)
1542 {
1543     ExternalSnapshotState *state = opaque;
1544     AioContext *aio_context;
1545 
1546     aio_context = bdrv_get_aio_context(state->old_bs);
1547     aio_context_acquire(aio_context);
1548 
1549     /* We don't need (or want) to use the transactional
1550      * bdrv_reopen_multiple() across all the entries at once, because we
1551      * don't want to abort all of them if one of them fails the reopen */
1552     if (!qatomic_read(&state->old_bs->copy_on_read)) {
1553         bdrv_reopen_set_read_only(state->old_bs, true, NULL);
1554     }
1555 
1556     aio_context_release(aio_context);
1557 }
1558 
1559 static void external_snapshot_abort(void *opaque)
1560 {
1561     ExternalSnapshotState *state = opaque;
1562     if (state->new_bs) {
1563         if (state->overlay_appended) {
1564             AioContext *aio_context;
1565             AioContext *tmp_context;
1566             int ret;
1567 
1568             aio_context = bdrv_get_aio_context(state->old_bs);
1569             aio_context_acquire(aio_context);
1570 
1571             bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
1572                                           close state->old_bs; we need it */
1573             bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
1574 
1575             /*
1576              * The call to bdrv_set_backing_hd() above returns state->old_bs to
1577              * the main AioContext. As we're still going to be using it, return
1578              * it to the AioContext it was before.
1579              */
1580             tmp_context = bdrv_get_aio_context(state->old_bs);
1581             if (aio_context != tmp_context) {
1582                 aio_context_release(aio_context);
1583                 aio_context_acquire(tmp_context);
1584 
1585                 ret = bdrv_try_change_aio_context(state->old_bs,
1586                                                   aio_context, NULL, NULL);
1587                 assert(ret == 0);
1588 
1589                 aio_context_release(tmp_context);
1590                 aio_context_acquire(aio_context);
1591             }
1592 
1593             bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
1594             bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
1595 
1596             aio_context_release(aio_context);
1597         }
1598     }
1599 }
1600 
1601 static void external_snapshot_clean(void *opaque)
1602 {
1603     g_autofree ExternalSnapshotState *state = opaque;
1604     AioContext *aio_context;
1605 
1606     if (!state->old_bs) {
1607         return;
1608     }
1609 
1610     aio_context = bdrv_get_aio_context(state->old_bs);
1611     aio_context_acquire(aio_context);
1612 
1613     bdrv_drained_end(state->old_bs);
1614     bdrv_unref(state->new_bs);
1615 
1616     aio_context_release(aio_context);
1617 }
1618 
1619 typedef struct DriveBackupState {
1620     BlockDriverState *bs;
1621     BlockJob *job;
1622 } DriveBackupState;
1623 
1624 static BlockJob *do_backup_common(BackupCommon *backup,
1625                                   BlockDriverState *bs,
1626                                   BlockDriverState *target_bs,
1627                                   AioContext *aio_context,
1628                                   JobTxn *txn, Error **errp);
1629 
1630 static void drive_backup_commit(void *opaque);
1631 static void drive_backup_abort(void *opaque);
1632 static void drive_backup_clean(void *opaque);
1633 TransactionActionDrv drive_backup_drv = {
1634     .commit = drive_backup_commit,
1635     .abort = drive_backup_abort,
1636     .clean = drive_backup_clean,
1637 };
1638 
1639 static void drive_backup_action(DriveBackup *backup,
1640                                 JobTxn *block_job_txn,
1641                                 Transaction *tran, Error **errp)
1642 {
1643     DriveBackupState *state = g_new0(DriveBackupState, 1);
1644     BlockDriverState *bs;
1645     BlockDriverState *target_bs;
1646     BlockDriverState *source = NULL;
1647     AioContext *aio_context;
1648     AioContext *old_context;
1649     const char *format;
1650     QDict *options;
1651     Error *local_err = NULL;
1652     int flags;
1653     int64_t size;
1654     bool set_backing_hd = false;
1655     int ret;
1656 
1657     tran_add(tran, &drive_backup_drv, state);
1658 
1659     if (!backup->has_mode) {
1660         backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1661     }
1662 
1663     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1664     if (!bs) {
1665         return;
1666     }
1667 
1668     if (!bs->drv) {
1669         error_setg(errp, "Device has no medium");
1670         return;
1671     }
1672 
1673     aio_context = bdrv_get_aio_context(bs);
1674     aio_context_acquire(aio_context);
1675 
1676     state->bs = bs;
1677     /* Paired with .clean() */
1678     bdrv_drained_begin(bs);
1679 
1680     format = backup->format;
1681     if (!format && backup->mode != NEW_IMAGE_MODE_EXISTING) {
1682         format = bs->drv->format_name;
1683     }
1684 
1685     /* Early check to avoid creating target */
1686     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
1687         goto out;
1688     }
1689 
1690     flags = bs->open_flags | BDRV_O_RDWR;
1691 
1692     /*
1693      * See if we have a backing HD we can use to create our new image
1694      * on top of.
1695      */
1696     if (backup->sync == MIRROR_SYNC_MODE_TOP) {
1697         /*
1698          * Backup will not replace the source by the target, so none
1699          * of the filters skipped here will be removed (in contrast to
1700          * mirror).  Therefore, we can skip all of them when looking
1701          * for the first COW relationship.
1702          */
1703         source = bdrv_cow_bs(bdrv_skip_filters(bs));
1704         if (!source) {
1705             backup->sync = MIRROR_SYNC_MODE_FULL;
1706         }
1707     }
1708     if (backup->sync == MIRROR_SYNC_MODE_NONE) {
1709         source = bs;
1710         flags |= BDRV_O_NO_BACKING;
1711         set_backing_hd = true;
1712     }
1713 
1714     size = bdrv_getlength(bs);
1715     if (size < 0) {
1716         error_setg_errno(errp, -size, "bdrv_getlength failed");
1717         goto out;
1718     }
1719 
1720     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
1721         assert(format);
1722         if (source) {
1723             /* Implicit filters should not appear in the filename */
1724             BlockDriverState *explicit_backing =
1725                 bdrv_skip_implicit_filters(source);
1726 
1727             bdrv_refresh_filename(explicit_backing);
1728             bdrv_img_create(backup->target, format,
1729                             explicit_backing->filename,
1730                             explicit_backing->drv->format_name, NULL,
1731                             size, flags, false, &local_err);
1732         } else {
1733             bdrv_img_create(backup->target, format, NULL, NULL, NULL,
1734                             size, flags, false, &local_err);
1735         }
1736     }
1737 
1738     if (local_err) {
1739         error_propagate(errp, local_err);
1740         goto out;
1741     }
1742 
1743     options = qdict_new();
1744     qdict_put_str(options, "discard", "unmap");
1745     qdict_put_str(options, "detect-zeroes", "unmap");
1746     if (format) {
1747         qdict_put_str(options, "driver", format);
1748     }
1749     aio_context_release(aio_context);
1750 
1751     aio_context_acquire(qemu_get_aio_context());
1752     target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
1753     aio_context_release(qemu_get_aio_context());
1754 
1755     if (!target_bs) {
1756         return;
1757     }
1758 
1759     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1760     old_context = bdrv_get_aio_context(target_bs);
1761     aio_context_acquire(old_context);
1762 
1763     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1764     if (ret < 0) {
1765         bdrv_unref(target_bs);
1766         aio_context_release(old_context);
1767         return;
1768     }
1769 
1770     aio_context_release(old_context);
1771     aio_context_acquire(aio_context);
1772 
1773     if (set_backing_hd) {
1774         if (bdrv_set_backing_hd(target_bs, source, errp) < 0) {
1775             goto unref;
1776         }
1777     }
1778 
1779     state->job = do_backup_common(qapi_DriveBackup_base(backup),
1780                                   bs, target_bs, aio_context,
1781                                   block_job_txn, errp);
1782 
1783 unref:
1784     bdrv_unref(target_bs);
1785 out:
1786     aio_context_release(aio_context);
1787 }
1788 
1789 static void drive_backup_commit(void *opaque)
1790 {
1791     DriveBackupState *state = opaque;
1792     AioContext *aio_context;
1793 
1794     aio_context = bdrv_get_aio_context(state->bs);
1795     aio_context_acquire(aio_context);
1796 
1797     assert(state->job);
1798     job_start(&state->job->job);
1799 
1800     aio_context_release(aio_context);
1801 }
1802 
1803 static void drive_backup_abort(void *opaque)
1804 {
1805     DriveBackupState *state = opaque;
1806 
1807     if (state->job) {
1808         job_cancel_sync(&state->job->job, true);
1809     }
1810 }
1811 
1812 static void drive_backup_clean(void *opaque)
1813 {
1814     g_autofree DriveBackupState *state = opaque;
1815     AioContext *aio_context;
1816 
1817     if (!state->bs) {
1818         return;
1819     }
1820 
1821     aio_context = bdrv_get_aio_context(state->bs);
1822     aio_context_acquire(aio_context);
1823 
1824     bdrv_drained_end(state->bs);
1825 
1826     aio_context_release(aio_context);
1827 }
1828 
1829 typedef struct BlockdevBackupState {
1830     BlockDriverState *bs;
1831     BlockJob *job;
1832 } BlockdevBackupState;
1833 
1834 static void blockdev_backup_commit(void *opaque);
1835 static void blockdev_backup_abort(void *opaque);
1836 static void blockdev_backup_clean(void *opaque);
1837 TransactionActionDrv blockdev_backup_drv = {
1838     .commit = blockdev_backup_commit,
1839     .abort = blockdev_backup_abort,
1840     .clean = blockdev_backup_clean,
1841 };
1842 
1843 static void blockdev_backup_action(BlockdevBackup *backup,
1844                                    JobTxn *block_job_txn,
1845                                    Transaction *tran, Error **errp)
1846 {
1847     BlockdevBackupState *state = g_new0(BlockdevBackupState, 1);
1848     BlockDriverState *bs;
1849     BlockDriverState *target_bs;
1850     AioContext *aio_context;
1851     AioContext *old_context;
1852     int ret;
1853 
1854     tran_add(tran, &blockdev_backup_drv, state);
1855 
1856     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1857     if (!bs) {
1858         return;
1859     }
1860 
1861     target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);
1862     if (!target_bs) {
1863         return;
1864     }
1865 
1866     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1867     aio_context = bdrv_get_aio_context(bs);
1868     old_context = bdrv_get_aio_context(target_bs);
1869     aio_context_acquire(old_context);
1870 
1871     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1872     if (ret < 0) {
1873         aio_context_release(old_context);
1874         return;
1875     }
1876 
1877     aio_context_release(old_context);
1878     aio_context_acquire(aio_context);
1879     state->bs = bs;
1880 
1881     /* Paired with .clean() */
1882     bdrv_drained_begin(state->bs);
1883 
1884     state->job = do_backup_common(qapi_BlockdevBackup_base(backup),
1885                                   bs, target_bs, aio_context,
1886                                   block_job_txn, errp);
1887 
1888     aio_context_release(aio_context);
1889 }
1890 
1891 static void blockdev_backup_commit(void *opaque)
1892 {
1893     BlockdevBackupState *state = opaque;
1894     AioContext *aio_context;
1895 
1896     aio_context = bdrv_get_aio_context(state->bs);
1897     aio_context_acquire(aio_context);
1898 
1899     assert(state->job);
1900     job_start(&state->job->job);
1901 
1902     aio_context_release(aio_context);
1903 }
1904 
1905 static void blockdev_backup_abort(void *opaque)
1906 {
1907     BlockdevBackupState *state = opaque;
1908 
1909     if (state->job) {
1910         job_cancel_sync(&state->job->job, true);
1911     }
1912 }
1913 
1914 static void blockdev_backup_clean(void *opaque)
1915 {
1916     g_autofree BlockdevBackupState *state = opaque;
1917     AioContext *aio_context;
1918 
1919     if (!state->bs) {
1920         return;
1921     }
1922 
1923     aio_context = bdrv_get_aio_context(state->bs);
1924     aio_context_acquire(aio_context);
1925 
1926     bdrv_drained_end(state->bs);
1927 
1928     aio_context_release(aio_context);
1929 }
1930 
1931 typedef struct BlockDirtyBitmapState {
1932     BdrvDirtyBitmap *bitmap;
1933     BlockDriverState *bs;
1934     HBitmap *backup;
1935     bool was_enabled;
1936 } BlockDirtyBitmapState;
1937 
1938 static void block_dirty_bitmap_add_abort(void *opaque);
1939 TransactionActionDrv block_dirty_bitmap_add_drv = {
1940     .abort = block_dirty_bitmap_add_abort,
1941     .clean = g_free,
1942 };
1943 
1944 static void block_dirty_bitmap_add_action(BlockDirtyBitmapAdd *action,
1945                                           Transaction *tran, Error **errp)
1946 {
1947     Error *local_err = NULL;
1948     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1949 
1950     tran_add(tran, &block_dirty_bitmap_add_drv, state);
1951 
1952     /* AIO context taken and released within qmp_block_dirty_bitmap_add */
1953     qmp_block_dirty_bitmap_add(action->node, action->name,
1954                                action->has_granularity, action->granularity,
1955                                action->has_persistent, action->persistent,
1956                                action->has_disabled, action->disabled,
1957                                &local_err);
1958 
1959     if (!local_err) {
1960         state->bitmap = block_dirty_bitmap_lookup(action->node, action->name,
1961                                                   NULL, &error_abort);
1962     } else {
1963         error_propagate(errp, local_err);
1964     }
1965 }
1966 
1967 static void block_dirty_bitmap_add_abort(void *opaque)
1968 {
1969     BlockDirtyBitmapState *state = opaque;
1970 
1971     if (state->bitmap) {
1972         bdrv_release_dirty_bitmap(state->bitmap);
1973     }
1974 }
1975 
1976 static void block_dirty_bitmap_restore(void *opaque);
1977 static void block_dirty_bitmap_free_backup(void *opaque);
1978 TransactionActionDrv block_dirty_bitmap_clear_drv = {
1979     .abort = block_dirty_bitmap_restore,
1980     .commit = block_dirty_bitmap_free_backup,
1981     .clean = g_free,
1982 };
1983 
1984 static void block_dirty_bitmap_clear_action(BlockDirtyBitmap *action,
1985                                             Transaction *tran, Error **errp)
1986 {
1987     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1988 
1989     tran_add(tran, &block_dirty_bitmap_clear_drv, state);
1990 
1991     state->bitmap = block_dirty_bitmap_lookup(action->node,
1992                                               action->name,
1993                                               &state->bs,
1994                                               errp);
1995     if (!state->bitmap) {
1996         return;
1997     }
1998 
1999     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_DEFAULT, errp)) {
2000         return;
2001     }
2002 
2003     bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
2004 }
2005 
2006 static void block_dirty_bitmap_restore(void *opaque)
2007 {
2008     BlockDirtyBitmapState *state = opaque;
2009 
2010     if (state->backup) {
2011         bdrv_restore_dirty_bitmap(state->bitmap, state->backup);
2012     }
2013 }
2014 
2015 static void block_dirty_bitmap_free_backup(void *opaque)
2016 {
2017     BlockDirtyBitmapState *state = opaque;
2018 
2019     hbitmap_free(state->backup);
2020 }
2021 
2022 static void block_dirty_bitmap_enable_abort(void *opaque);
2023 TransactionActionDrv block_dirty_bitmap_enable_drv = {
2024     .abort = block_dirty_bitmap_enable_abort,
2025     .clean = g_free,
2026 };
2027 
2028 static void block_dirty_bitmap_enable_action(BlockDirtyBitmap *action,
2029                                              Transaction *tran, Error **errp)
2030 {
2031     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2032 
2033     tran_add(tran, &block_dirty_bitmap_enable_drv, state);
2034 
2035     state->bitmap = block_dirty_bitmap_lookup(action->node,
2036                                               action->name,
2037                                               NULL,
2038                                               errp);
2039     if (!state->bitmap) {
2040         return;
2041     }
2042 
2043     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2044         return;
2045     }
2046 
2047     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2048     bdrv_enable_dirty_bitmap(state->bitmap);
2049 }
2050 
2051 static void block_dirty_bitmap_enable_abort(void *opaque)
2052 {
2053     BlockDirtyBitmapState *state = opaque;
2054 
2055     if (!state->was_enabled) {
2056         bdrv_disable_dirty_bitmap(state->bitmap);
2057     }
2058 }
2059 
2060 static void block_dirty_bitmap_disable_abort(void *opaque);
2061 TransactionActionDrv block_dirty_bitmap_disable_drv = {
2062     .abort = block_dirty_bitmap_disable_abort,
2063     .clean = g_free,
2064 };
2065 
2066 static void block_dirty_bitmap_disable_action(BlockDirtyBitmap *action,
2067                                               Transaction *tran, Error **errp)
2068 {
2069     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2070 
2071     tran_add(tran, &block_dirty_bitmap_disable_drv, state);
2072 
2073     state->bitmap = block_dirty_bitmap_lookup(action->node,
2074                                               action->name,
2075                                               NULL,
2076                                               errp);
2077     if (!state->bitmap) {
2078         return;
2079     }
2080 
2081     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2082         return;
2083     }
2084 
2085     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2086     bdrv_disable_dirty_bitmap(state->bitmap);
2087 }
2088 
2089 static void block_dirty_bitmap_disable_abort(void *opaque)
2090 {
2091     BlockDirtyBitmapState *state = opaque;
2092 
2093     if (state->was_enabled) {
2094         bdrv_enable_dirty_bitmap(state->bitmap);
2095     }
2096 }
2097 
2098 TransactionActionDrv block_dirty_bitmap_merge_drv = {
2099     .commit = block_dirty_bitmap_free_backup,
2100     .abort = block_dirty_bitmap_restore,
2101     .clean = g_free,
2102 };
2103 
2104 static void block_dirty_bitmap_merge_action(BlockDirtyBitmapMerge *action,
2105                                             Transaction *tran, Error **errp)
2106 {
2107     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2108 
2109     tran_add(tran, &block_dirty_bitmap_merge_drv, state);
2110 
2111     state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
2112                                              action->bitmaps, &state->backup,
2113                                              errp);
2114 }
2115 
2116 static void block_dirty_bitmap_remove_commit(void *opaque);
2117 static void block_dirty_bitmap_remove_abort(void *opaque);
2118 TransactionActionDrv block_dirty_bitmap_remove_drv = {
2119     .commit = block_dirty_bitmap_remove_commit,
2120     .abort = block_dirty_bitmap_remove_abort,
2121     .clean = g_free,
2122 };
2123 
2124 static void block_dirty_bitmap_remove_action(BlockDirtyBitmap *action,
2125                                              Transaction *tran, Error **errp)
2126 {
2127     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2128 
2129     tran_add(tran, &block_dirty_bitmap_remove_drv, state);
2130 
2131 
2132     state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
2133                                               false, &state->bs, errp);
2134     if (state->bitmap) {
2135         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
2136         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
2137     }
2138 }
2139 
2140 static void block_dirty_bitmap_remove_abort(void *opaque)
2141 {
2142     BlockDirtyBitmapState *state = opaque;
2143 
2144     if (state->bitmap) {
2145         bdrv_dirty_bitmap_skip_store(state->bitmap, false);
2146         bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2147     }
2148 }
2149 
2150 static void block_dirty_bitmap_remove_commit(void *opaque)
2151 {
2152     BlockDirtyBitmapState *state = opaque;
2153 
2154     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2155     bdrv_release_dirty_bitmap(state->bitmap);
2156 }
2157 
2158 static void abort_commit(void *opaque);
2159 TransactionActionDrv abort_drv = {
2160     .commit = abort_commit,
2161 };
2162 
2163 static void abort_action(Transaction *tran, Error **errp)
2164 {
2165     tran_add(tran, &abort_drv, NULL);
2166     error_setg(errp, "Transaction aborted using Abort action");
2167 }
2168 
2169 static void abort_commit(void *opaque)
2170 {
2171     g_assert_not_reached(); /* this action never succeeds */
2172 }
2173 
2174 static void transaction_action(TransactionAction *act, JobTxn *block_job_txn,
2175                                Transaction *tran, Error **errp)
2176 {
2177     switch (act->type) {
2178     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
2179     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
2180         external_snapshot_action(act, tran, errp);
2181         return;
2182     case TRANSACTION_ACTION_KIND_DRIVE_BACKUP:
2183         drive_backup_action(act->u.drive_backup.data,
2184                             block_job_txn, tran, errp);
2185         return;
2186     case TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP:
2187         blockdev_backup_action(act->u.blockdev_backup.data,
2188                                block_job_txn, tran, errp);
2189         return;
2190     case TRANSACTION_ACTION_KIND_ABORT:
2191         abort_action(tran, errp);
2192         return;
2193     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC:
2194         internal_snapshot_action(act->u.blockdev_snapshot_internal_sync.data,
2195                                  tran, errp);
2196         return;
2197     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD:
2198         block_dirty_bitmap_add_action(act->u.block_dirty_bitmap_add.data,
2199                                       tran, errp);
2200         return;
2201     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR:
2202         block_dirty_bitmap_clear_action(act->u.block_dirty_bitmap_clear.data,
2203                                         tran, errp);
2204         return;
2205     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE:
2206         block_dirty_bitmap_enable_action(act->u.block_dirty_bitmap_enable.data,
2207                                          tran, errp);
2208         return;
2209     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE:
2210         block_dirty_bitmap_disable_action(
2211                 act->u.block_dirty_bitmap_disable.data, tran, errp);
2212         return;
2213     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE:
2214         block_dirty_bitmap_merge_action(act->u.block_dirty_bitmap_merge.data,
2215                                         tran, errp);
2216         return;
2217     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_REMOVE:
2218         block_dirty_bitmap_remove_action(act->u.block_dirty_bitmap_remove.data,
2219                                          tran, errp);
2220         return;
2221     /*
2222      * Where are transactions for MIRROR, COMMIT and STREAM?
2223      * Although these blockjobs use transaction callbacks like the backup job,
2224      * these jobs do not necessarily adhere to transaction semantics.
2225      * These jobs may not fully undo all of their actions on abort, nor do they
2226      * necessarily work in transactions with more than one job in them.
2227      */
2228     case TRANSACTION_ACTION_KIND__MAX:
2229     default:
2230         g_assert_not_reached();
2231     };
2232 }
2233 
2234 
2235 /*
2236  * 'Atomic' group operations.  The operations are performed as a set, and if
2237  * any fail then we roll back all operations in the group.
2238  *
2239  * Always run under BQL.
2240  */
2241 void qmp_transaction(TransactionActionList *actions,
2242                      struct TransactionProperties *properties,
2243                      Error **errp)
2244 {
2245     TransactionActionList *act;
2246     JobTxn *block_job_txn = NULL;
2247     Error *local_err = NULL;
2248     Transaction *tran;
2249     ActionCompletionMode comp_mode =
2250         properties ? properties->completion_mode :
2251         ACTION_COMPLETION_MODE_INDIVIDUAL;
2252 
2253     GLOBAL_STATE_CODE();
2254 
2255     /* Does this transaction get canceled as a group on failure?
2256      * If not, we don't really need to make a JobTxn.
2257      */
2258     if (comp_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
2259         for (act = actions; act; act = act->next) {
2260             TransactionActionKind type = act->value->type;
2261 
2262             if (type != TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP &&
2263                 type != TRANSACTION_ACTION_KIND_DRIVE_BACKUP)
2264             {
2265                 error_setg(errp,
2266                            "Action '%s' does not support transaction property "
2267                            "completion-mode = %s",
2268                            TransactionActionKind_str(type),
2269                            ActionCompletionMode_str(comp_mode));
2270                 return;
2271             }
2272         }
2273 
2274         block_job_txn = job_txn_new();
2275     }
2276 
2277     /* drain all i/o before any operations */
2278     bdrv_drain_all();
2279 
2280     tran = tran_new();
2281 
2282     /* We don't do anything in this loop that commits us to the operations */
2283     for (act = actions; act; act = act->next) {
2284         transaction_action(act->value, block_job_txn, tran, &local_err);
2285         if (local_err) {
2286             error_propagate(errp, local_err);
2287             goto delete_and_fail;
2288         }
2289     }
2290 
2291     tran_commit(tran);
2292 
2293     /* success */
2294     goto exit;
2295 
2296 delete_and_fail:
2297     /* failure, and it is all-or-none; roll back all operations */
2298     tran_abort(tran);
2299 exit:
2300     job_txn_unref(block_job_txn);
2301 }
2302 
2303 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
2304                                                               const char *name,
2305                                                               Error **errp)
2306 {
2307     BdrvDirtyBitmap *bitmap;
2308     BlockDriverState *bs;
2309     BlockDirtyBitmapSha256 *ret = NULL;
2310     char *sha256;
2311 
2312     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
2313     if (!bitmap || !bs) {
2314         return NULL;
2315     }
2316 
2317     sha256 = bdrv_dirty_bitmap_sha256(bitmap, errp);
2318     if (sha256 == NULL) {
2319         return NULL;
2320     }
2321 
2322     ret = g_new(BlockDirtyBitmapSha256, 1);
2323     ret->sha256 = sha256;
2324 
2325     return ret;
2326 }
2327 
2328 void coroutine_fn qmp_block_resize(const char *device, const char *node_name,
2329                                    int64_t size, Error **errp)
2330 {
2331     Error *local_err = NULL;
2332     BlockBackend *blk;
2333     BlockDriverState *bs;
2334     AioContext *old_ctx;
2335 
2336     bs = bdrv_lookup_bs(device, node_name, &local_err);
2337     if (local_err) {
2338         error_propagate(errp, local_err);
2339         return;
2340     }
2341 
2342     if (size < 0) {
2343         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
2344         return;
2345     }
2346 
2347     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
2348         error_setg(errp, QERR_DEVICE_IN_USE, device);
2349         return;
2350     }
2351 
2352     blk = blk_co_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, errp);
2353     if (!blk) {
2354         return;
2355     }
2356 
2357     bdrv_co_lock(bs);
2358     bdrv_drained_begin(bs);
2359     bdrv_co_unlock(bs);
2360 
2361     old_ctx = bdrv_co_enter(bs);
2362     blk_co_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
2363     bdrv_co_leave(bs, old_ctx);
2364 
2365     bdrv_co_lock(bs);
2366     bdrv_drained_end(bs);
2367     blk_co_unref(blk);
2368     bdrv_co_unlock(bs);
2369 }
2370 
2371 void qmp_block_stream(const char *job_id, const char *device,
2372                       const char *base,
2373                       const char *base_node,
2374                       const char *backing_file,
2375                       const char *bottom,
2376                       bool has_speed, int64_t speed,
2377                       bool has_on_error, BlockdevOnError on_error,
2378                       const char *filter_node_name,
2379                       bool has_auto_finalize, bool auto_finalize,
2380                       bool has_auto_dismiss, bool auto_dismiss,
2381                       Error **errp)
2382 {
2383     BlockDriverState *bs, *iter, *iter_end;
2384     BlockDriverState *base_bs = NULL;
2385     BlockDriverState *bottom_bs = NULL;
2386     AioContext *aio_context;
2387     Error *local_err = NULL;
2388     int job_flags = JOB_DEFAULT;
2389 
2390     if (base && base_node) {
2391         error_setg(errp, "'base' and 'base-node' cannot be specified "
2392                    "at the same time");
2393         return;
2394     }
2395 
2396     if (base && bottom) {
2397         error_setg(errp, "'base' and 'bottom' cannot be specified "
2398                    "at the same time");
2399         return;
2400     }
2401 
2402     if (bottom && base_node) {
2403         error_setg(errp, "'bottom' and 'base-node' cannot be specified "
2404                    "at the same time");
2405         return;
2406     }
2407 
2408     if (!has_on_error) {
2409         on_error = BLOCKDEV_ON_ERROR_REPORT;
2410     }
2411 
2412     bs = bdrv_lookup_bs(device, device, errp);
2413     if (!bs) {
2414         return;
2415     }
2416 
2417     aio_context = bdrv_get_aio_context(bs);
2418     aio_context_acquire(aio_context);
2419 
2420     if (base) {
2421         base_bs = bdrv_find_backing_image(bs, base);
2422         if (base_bs == NULL) {
2423             error_setg(errp, "Can't find '%s' in the backing chain", base);
2424             goto out;
2425         }
2426         assert(bdrv_get_aio_context(base_bs) == aio_context);
2427     }
2428 
2429     if (base_node) {
2430         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2431         if (!base_bs) {
2432             goto out;
2433         }
2434         if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) {
2435             error_setg(errp, "Node '%s' is not a backing image of '%s'",
2436                        base_node, device);
2437             goto out;
2438         }
2439         assert(bdrv_get_aio_context(base_bs) == aio_context);
2440         bdrv_refresh_filename(base_bs);
2441     }
2442 
2443     if (bottom) {
2444         bottom_bs = bdrv_lookup_bs(NULL, bottom, errp);
2445         if (!bottom_bs) {
2446             goto out;
2447         }
2448         if (!bottom_bs->drv) {
2449             error_setg(errp, "Node '%s' is not open", bottom);
2450             goto out;
2451         }
2452         if (bottom_bs->drv->is_filter) {
2453             error_setg(errp, "Node '%s' is a filter, use a non-filter node "
2454                        "as 'bottom'", bottom);
2455             goto out;
2456         }
2457         if (!bdrv_chain_contains(bs, bottom_bs)) {
2458             error_setg(errp, "Node '%s' is not in a chain starting from '%s'",
2459                        bottom, device);
2460             goto out;
2461         }
2462         assert(bdrv_get_aio_context(bottom_bs) == aio_context);
2463     }
2464 
2465     /*
2466      * Check for op blockers in the whole chain between bs and base (or bottom)
2467      */
2468     iter_end = bottom ? bdrv_filter_or_cow_bs(bottom_bs) : base_bs;
2469     for (iter = bs; iter && iter != iter_end;
2470          iter = bdrv_filter_or_cow_bs(iter))
2471     {
2472         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
2473             goto out;
2474         }
2475     }
2476 
2477     /* if we are streaming the entire chain, the result will have no backing
2478      * file, and specifying one is therefore an error */
2479     if (!base_bs && backing_file) {
2480         error_setg(errp, "backing file specified, but streaming the "
2481                          "entire chain");
2482         goto out;
2483     }
2484 
2485     if (has_auto_finalize && !auto_finalize) {
2486         job_flags |= JOB_MANUAL_FINALIZE;
2487     }
2488     if (has_auto_dismiss && !auto_dismiss) {
2489         job_flags |= JOB_MANUAL_DISMISS;
2490     }
2491 
2492     stream_start(job_id, bs, base_bs, backing_file,
2493                  bottom_bs, job_flags, has_speed ? speed : 0, on_error,
2494                  filter_node_name, &local_err);
2495     if (local_err) {
2496         error_propagate(errp, local_err);
2497         goto out;
2498     }
2499 
2500     trace_qmp_block_stream(bs);
2501 
2502 out:
2503     aio_context_release(aio_context);
2504 }
2505 
2506 void qmp_block_commit(const char *job_id, const char *device,
2507                       const char *base_node,
2508                       const char *base,
2509                       const char *top_node,
2510                       const char *top,
2511                       const char *backing_file,
2512                       bool has_speed, int64_t speed,
2513                       bool has_on_error, BlockdevOnError on_error,
2514                       const char *filter_node_name,
2515                       bool has_auto_finalize, bool auto_finalize,
2516                       bool has_auto_dismiss, bool auto_dismiss,
2517                       Error **errp)
2518 {
2519     BlockDriverState *bs;
2520     BlockDriverState *iter;
2521     BlockDriverState *base_bs, *top_bs;
2522     AioContext *aio_context;
2523     Error *local_err = NULL;
2524     int job_flags = JOB_DEFAULT;
2525     uint64_t top_perm, top_shared;
2526 
2527     /* TODO We'll eventually have to take a writer lock in this function */
2528     GRAPH_RDLOCK_GUARD_MAINLOOP();
2529 
2530     if (!has_speed) {
2531         speed = 0;
2532     }
2533     if (!has_on_error) {
2534         on_error = BLOCKDEV_ON_ERROR_REPORT;
2535     }
2536     if (has_auto_finalize && !auto_finalize) {
2537         job_flags |= JOB_MANUAL_FINALIZE;
2538     }
2539     if (has_auto_dismiss && !auto_dismiss) {
2540         job_flags |= JOB_MANUAL_DISMISS;
2541     }
2542 
2543     /* Important Note:
2544      *  libvirt relies on the DeviceNotFound error class in order to probe for
2545      *  live commit feature versions; for this to work, we must make sure to
2546      *  perform the device lookup before any generic errors that may occur in a
2547      *  scenario in which all optional arguments are omitted. */
2548     bs = qmp_get_root_bs(device, &local_err);
2549     if (!bs) {
2550         bs = bdrv_lookup_bs(device, device, NULL);
2551         if (!bs) {
2552             error_free(local_err);
2553             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
2554                       "Device '%s' not found", device);
2555         } else {
2556             error_propagate(errp, local_err);
2557         }
2558         return;
2559     }
2560 
2561     aio_context = bdrv_get_aio_context(bs);
2562     aio_context_acquire(aio_context);
2563 
2564     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
2565         goto out;
2566     }
2567 
2568     /* default top_bs is the active layer */
2569     top_bs = bs;
2570 
2571     if (top_node && top) {
2572         error_setg(errp, "'top-node' and 'top' are mutually exclusive");
2573         goto out;
2574     } else if (top_node) {
2575         top_bs = bdrv_lookup_bs(NULL, top_node, errp);
2576         if (top_bs == NULL) {
2577             goto out;
2578         }
2579         if (!bdrv_chain_contains(bs, top_bs)) {
2580             error_setg(errp, "'%s' is not in this backing file chain",
2581                        top_node);
2582             goto out;
2583         }
2584     } else if (top) {
2585         /* This strcmp() is just a shortcut, there is no need to
2586          * refresh @bs's filename.  If it mismatches,
2587          * bdrv_find_backing_image() will do the refresh and may still
2588          * return @bs. */
2589         if (strcmp(bs->filename, top) != 0) {
2590             top_bs = bdrv_find_backing_image(bs, top);
2591         }
2592     }
2593 
2594     if (top_bs == NULL) {
2595         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
2596         goto out;
2597     }
2598 
2599     assert(bdrv_get_aio_context(top_bs) == aio_context);
2600 
2601     if (base_node && base) {
2602         error_setg(errp, "'base-node' and 'base' are mutually exclusive");
2603         goto out;
2604     } else if (base_node) {
2605         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2606         if (base_bs == NULL) {
2607             goto out;
2608         }
2609         if (!bdrv_chain_contains(top_bs, base_bs)) {
2610             error_setg(errp, "'%s' is not in this backing file chain",
2611                        base_node);
2612             goto out;
2613         }
2614     } else if (base) {
2615         base_bs = bdrv_find_backing_image(top_bs, base);
2616         if (base_bs == NULL) {
2617             error_setg(errp, "Can't find '%s' in the backing chain", base);
2618             goto out;
2619         }
2620     } else {
2621         base_bs = bdrv_find_base(top_bs);
2622         if (base_bs == NULL) {
2623             error_setg(errp, "There is no backimg image");
2624             goto out;
2625         }
2626     }
2627 
2628     assert(bdrv_get_aio_context(base_bs) == aio_context);
2629 
2630     for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs);
2631          iter = bdrv_filter_or_cow_bs(iter))
2632     {
2633         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2634             goto out;
2635         }
2636     }
2637 
2638     /* Do not allow attempts to commit an image into itself */
2639     if (top_bs == base_bs) {
2640         error_setg(errp, "cannot commit an image into itself");
2641         goto out;
2642     }
2643 
2644     /*
2645      * Active commit is required if and only if someone has taken a
2646      * WRITE permission on the top node.  Historically, we have always
2647      * used active commit for top nodes, so continue that practice
2648      * lest we possibly break clients that rely on this behavior, e.g.
2649      * to later attach this node to a writing parent.
2650      * (Active commit is never really wrong.)
2651      */
2652     bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared);
2653     if (top_perm & BLK_PERM_WRITE ||
2654         bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs))
2655     {
2656         if (backing_file) {
2657             if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) {
2658                 error_setg(errp, "'backing-file' specified,"
2659                                  " but 'top' is the active layer");
2660             } else {
2661                 error_setg(errp, "'backing-file' specified, but 'top' has a "
2662                                  "writer on it");
2663             }
2664             goto out;
2665         }
2666         if (!job_id) {
2667             /*
2668              * Emulate here what block_job_create() does, because it
2669              * is possible that @bs != @top_bs (the block job should
2670              * be named after @bs, even if @top_bs is the actual
2671              * source)
2672              */
2673             job_id = bdrv_get_device_name(bs);
2674         }
2675         commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error,
2676                             filter_node_name, NULL, NULL, false, &local_err);
2677     } else {
2678         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
2679         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2680             goto out;
2681         }
2682         commit_start(job_id, bs, base_bs, top_bs, job_flags,
2683                      speed, on_error, backing_file,
2684                      filter_node_name, &local_err);
2685     }
2686     if (local_err != NULL) {
2687         error_propagate(errp, local_err);
2688         goto out;
2689     }
2690 
2691 out:
2692     aio_context_release(aio_context);
2693 }
2694 
2695 /* Common QMP interface for drive-backup and blockdev-backup */
2696 static BlockJob *do_backup_common(BackupCommon *backup,
2697                                   BlockDriverState *bs,
2698                                   BlockDriverState *target_bs,
2699                                   AioContext *aio_context,
2700                                   JobTxn *txn, Error **errp)
2701 {
2702     BlockJob *job = NULL;
2703     BdrvDirtyBitmap *bmap = NULL;
2704     BackupPerf perf = { .max_workers = 64 };
2705     int job_flags = JOB_DEFAULT;
2706 
2707     if (!backup->has_speed) {
2708         backup->speed = 0;
2709     }
2710     if (!backup->has_on_source_error) {
2711         backup->on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2712     }
2713     if (!backup->has_on_target_error) {
2714         backup->on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2715     }
2716     if (!backup->has_auto_finalize) {
2717         backup->auto_finalize = true;
2718     }
2719     if (!backup->has_auto_dismiss) {
2720         backup->auto_dismiss = true;
2721     }
2722     if (!backup->has_compress) {
2723         backup->compress = false;
2724     }
2725 
2726     if (backup->x_perf) {
2727         if (backup->x_perf->has_use_copy_range) {
2728             perf.use_copy_range = backup->x_perf->use_copy_range;
2729         }
2730         if (backup->x_perf->has_max_workers) {
2731             perf.max_workers = backup->x_perf->max_workers;
2732         }
2733         if (backup->x_perf->has_max_chunk) {
2734             perf.max_chunk = backup->x_perf->max_chunk;
2735         }
2736     }
2737 
2738     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||
2739         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
2740         /* done before desugaring 'incremental' to print the right message */
2741         if (!backup->bitmap) {
2742             error_setg(errp, "must provide a valid bitmap name for "
2743                        "'%s' sync mode", MirrorSyncMode_str(backup->sync));
2744             return NULL;
2745         }
2746     }
2747 
2748     if (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL) {
2749         if (backup->has_bitmap_mode &&
2750             backup->bitmap_mode != BITMAP_SYNC_MODE_ON_SUCCESS) {
2751             error_setg(errp, "Bitmap sync mode must be '%s' "
2752                        "when using sync mode '%s'",
2753                        BitmapSyncMode_str(BITMAP_SYNC_MODE_ON_SUCCESS),
2754                        MirrorSyncMode_str(backup->sync));
2755             return NULL;
2756         }
2757         backup->has_bitmap_mode = true;
2758         backup->sync = MIRROR_SYNC_MODE_BITMAP;
2759         backup->bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
2760     }
2761 
2762     if (backup->bitmap) {
2763         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
2764         if (!bmap) {
2765             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
2766             return NULL;
2767         }
2768         if (!backup->has_bitmap_mode) {
2769             error_setg(errp, "Bitmap sync mode must be given "
2770                        "when providing a bitmap");
2771             return NULL;
2772         }
2773         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2774             return NULL;
2775         }
2776 
2777         /* This does not produce a useful bitmap artifact: */
2778         if (backup->sync == MIRROR_SYNC_MODE_NONE) {
2779             error_setg(errp, "sync mode '%s' does not produce meaningful bitmap"
2780                        " outputs", MirrorSyncMode_str(backup->sync));
2781             return NULL;
2782         }
2783 
2784         /* If the bitmap isn't used for input or output, this is useless: */
2785         if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER &&
2786             backup->sync != MIRROR_SYNC_MODE_BITMAP) {
2787             error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect"
2788                        " when combined with sync mode '%s'",
2789                        BitmapSyncMode_str(backup->bitmap_mode),
2790                        MirrorSyncMode_str(backup->sync));
2791             return NULL;
2792         }
2793     }
2794 
2795     if (!backup->bitmap && backup->has_bitmap_mode) {
2796         error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
2797         return NULL;
2798     }
2799 
2800     if (!backup->auto_finalize) {
2801         job_flags |= JOB_MANUAL_FINALIZE;
2802     }
2803     if (!backup->auto_dismiss) {
2804         job_flags |= JOB_MANUAL_DISMISS;
2805     }
2806 
2807     job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
2808                             backup->sync, bmap, backup->bitmap_mode,
2809                             backup->compress,
2810                             backup->filter_node_name,
2811                             &perf,
2812                             backup->on_source_error,
2813                             backup->on_target_error,
2814                             job_flags, NULL, NULL, txn, errp);
2815     return job;
2816 }
2817 
2818 void qmp_drive_backup(DriveBackup *backup, Error **errp)
2819 {
2820     TransactionAction action = {
2821         .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
2822         .u.drive_backup.data = backup,
2823     };
2824     blockdev_do_action(&action, errp);
2825 }
2826 
2827 BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
2828                                                  bool flat,
2829                                                  Error **errp)
2830 {
2831     bool return_flat = has_flat && flat;
2832 
2833     return bdrv_named_nodes_list(return_flat, errp);
2834 }
2835 
2836 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
2837 {
2838     return bdrv_get_xdbg_block_graph(errp);
2839 }
2840 
2841 void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)
2842 {
2843     TransactionAction action = {
2844         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,
2845         .u.blockdev_backup.data = backup,
2846     };
2847     blockdev_do_action(&action, errp);
2848 }
2849 
2850 /* Parameter check and block job starting for drive mirroring.
2851  * Caller should hold @device and @target's aio context (must be the same).
2852  **/
2853 static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
2854                                    BlockDriverState *target,
2855                                    const char *replaces,
2856                                    enum MirrorSyncMode sync,
2857                                    BlockMirrorBackingMode backing_mode,
2858                                    bool zero_target,
2859                                    bool has_speed, int64_t speed,
2860                                    bool has_granularity, uint32_t granularity,
2861                                    bool has_buf_size, int64_t buf_size,
2862                                    bool has_on_source_error,
2863                                    BlockdevOnError on_source_error,
2864                                    bool has_on_target_error,
2865                                    BlockdevOnError on_target_error,
2866                                    bool has_unmap, bool unmap,
2867                                    const char *filter_node_name,
2868                                    bool has_copy_mode, MirrorCopyMode copy_mode,
2869                                    bool has_auto_finalize, bool auto_finalize,
2870                                    bool has_auto_dismiss, bool auto_dismiss,
2871                                    Error **errp)
2872 {
2873     BlockDriverState *unfiltered_bs;
2874     int job_flags = JOB_DEFAULT;
2875 
2876     GLOBAL_STATE_CODE();
2877     GRAPH_RDLOCK_GUARD_MAINLOOP();
2878 
2879     if (!has_speed) {
2880         speed = 0;
2881     }
2882     if (!has_on_source_error) {
2883         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2884     }
2885     if (!has_on_target_error) {
2886         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2887     }
2888     if (!has_granularity) {
2889         granularity = 0;
2890     }
2891     if (!has_buf_size) {
2892         buf_size = 0;
2893     }
2894     if (!has_unmap) {
2895         unmap = true;
2896     }
2897     if (!has_copy_mode) {
2898         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
2899     }
2900     if (has_auto_finalize && !auto_finalize) {
2901         job_flags |= JOB_MANUAL_FINALIZE;
2902     }
2903     if (has_auto_dismiss && !auto_dismiss) {
2904         job_flags |= JOB_MANUAL_DISMISS;
2905     }
2906 
2907     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
2908         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2909                    "a value in range [512B, 64MB]");
2910         return;
2911     }
2912     if (granularity & (granularity - 1)) {
2913         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2914                    "a power of 2");
2915         return;
2916     }
2917 
2918     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2919         return;
2920     }
2921     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
2922         return;
2923     }
2924 
2925     if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) {
2926         sync = MIRROR_SYNC_MODE_FULL;
2927     }
2928 
2929     if (!replaces) {
2930         /* We want to mirror from @bs, but keep implicit filters on top */
2931         unfiltered_bs = bdrv_skip_implicit_filters(bs);
2932         if (unfiltered_bs != bs) {
2933             replaces = unfiltered_bs->node_name;
2934         }
2935     }
2936 
2937     if (replaces) {
2938         BlockDriverState *to_replace_bs;
2939         AioContext *replace_aio_context;
2940         int64_t bs_size, replace_size;
2941 
2942         bs_size = bdrv_getlength(bs);
2943         if (bs_size < 0) {
2944             error_setg_errno(errp, -bs_size, "Failed to query device's size");
2945             return;
2946         }
2947 
2948         to_replace_bs = check_to_replace_node(bs, replaces, errp);
2949         if (!to_replace_bs) {
2950             return;
2951         }
2952 
2953         replace_aio_context = bdrv_get_aio_context(to_replace_bs);
2954         aio_context_acquire(replace_aio_context);
2955         replace_size = bdrv_getlength(to_replace_bs);
2956         aio_context_release(replace_aio_context);
2957 
2958         if (replace_size < 0) {
2959             error_setg_errno(errp, -replace_size,
2960                              "Failed to query the replacement node's size");
2961             return;
2962         }
2963         if (bs_size != replace_size) {
2964             error_setg(errp, "cannot replace image with a mirror image of "
2965                              "different size");
2966             return;
2967         }
2968     }
2969 
2970     /* pass the node name to replace to mirror start since it's loose coupling
2971      * and will allow to check whether the node still exist at mirror completion
2972      */
2973     mirror_start(job_id, bs, target,
2974                  replaces, job_flags,
2975                  speed, granularity, buf_size, sync, backing_mode, zero_target,
2976                  on_source_error, on_target_error, unmap, filter_node_name,
2977                  copy_mode, errp);
2978 }
2979 
2980 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
2981 {
2982     BlockDriverState *bs;
2983     BlockDriverState *target_backing_bs, *target_bs;
2984     AioContext *aio_context;
2985     AioContext *old_context;
2986     BlockMirrorBackingMode backing_mode;
2987     Error *local_err = NULL;
2988     QDict *options = NULL;
2989     int flags;
2990     int64_t size;
2991     const char *format = arg->format;
2992     bool zero_target;
2993     int ret;
2994 
2995     bs = qmp_get_root_bs(arg->device, errp);
2996     if (!bs) {
2997         return;
2998     }
2999 
3000     /* Early check to avoid creating target */
3001     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
3002         return;
3003     }
3004 
3005     aio_context = bdrv_get_aio_context(bs);
3006     aio_context_acquire(aio_context);
3007 
3008     if (!arg->has_mode) {
3009         arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
3010     }
3011 
3012     if (!arg->format) {
3013         format = (arg->mode == NEW_IMAGE_MODE_EXISTING
3014                   ? NULL : bs->drv->format_name);
3015     }
3016 
3017     flags = bs->open_flags | BDRV_O_RDWR;
3018     target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs));
3019     if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) {
3020         arg->sync = MIRROR_SYNC_MODE_FULL;
3021     }
3022     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
3023         target_backing_bs = bs;
3024     }
3025 
3026     size = bdrv_getlength(bs);
3027     if (size < 0) {
3028         error_setg_errno(errp, -size, "bdrv_getlength failed");
3029         goto out;
3030     }
3031 
3032     if (arg->replaces) {
3033         if (!arg->node_name) {
3034             error_setg(errp, "a node-name must be provided when replacing a"
3035                              " named node of the graph");
3036             goto out;
3037         }
3038     }
3039 
3040     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
3041         backing_mode = MIRROR_SOURCE_BACKING_CHAIN;
3042     } else {
3043         backing_mode = MIRROR_OPEN_BACKING_CHAIN;
3044     }
3045 
3046     /* Don't open backing image in create() */
3047     flags |= BDRV_O_NO_BACKING;
3048 
3049     if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs)
3050         && arg->mode != NEW_IMAGE_MODE_EXISTING)
3051     {
3052         /* create new image w/o backing file */
3053         assert(format);
3054         bdrv_img_create(arg->target, format,
3055                         NULL, NULL, NULL, size, flags, false, &local_err);
3056     } else {
3057         /* Implicit filters should not appear in the filename */
3058         BlockDriverState *explicit_backing =
3059             bdrv_skip_implicit_filters(target_backing_bs);
3060 
3061         switch (arg->mode) {
3062         case NEW_IMAGE_MODE_EXISTING:
3063             break;
3064         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
3065             /* create new image with backing file */
3066             bdrv_refresh_filename(explicit_backing);
3067             bdrv_img_create(arg->target, format,
3068                             explicit_backing->filename,
3069                             explicit_backing->drv->format_name,
3070                             NULL, size, flags, false, &local_err);
3071             break;
3072         default:
3073             abort();
3074         }
3075     }
3076 
3077     if (local_err) {
3078         error_propagate(errp, local_err);
3079         goto out;
3080     }
3081 
3082     options = qdict_new();
3083     if (arg->node_name) {
3084         qdict_put_str(options, "node-name", arg->node_name);
3085     }
3086     if (format) {
3087         qdict_put_str(options, "driver", format);
3088     }
3089     aio_context_release(aio_context);
3090 
3091     /* Mirroring takes care of copy-on-write using the source's backing
3092      * file.
3093      */
3094     aio_context_acquire(qemu_get_aio_context());
3095     target_bs = bdrv_open(arg->target, NULL, options, flags, errp);
3096     aio_context_release(qemu_get_aio_context());
3097 
3098     if (!target_bs) {
3099         return;
3100     }
3101 
3102     zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
3103                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||
3104                     !bdrv_has_zero_init(target_bs)));
3105 
3106 
3107     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3108     old_context = bdrv_get_aio_context(target_bs);
3109     aio_context_acquire(old_context);
3110 
3111     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3112     if (ret < 0) {
3113         bdrv_unref(target_bs);
3114         aio_context_release(old_context);
3115         return;
3116     }
3117 
3118     aio_context_release(old_context);
3119     aio_context_acquire(aio_context);
3120 
3121     blockdev_mirror_common(arg->job_id, bs, target_bs,
3122                            arg->replaces, arg->sync,
3123                            backing_mode, zero_target,
3124                            arg->has_speed, arg->speed,
3125                            arg->has_granularity, arg->granularity,
3126                            arg->has_buf_size, arg->buf_size,
3127                            arg->has_on_source_error, arg->on_source_error,
3128                            arg->has_on_target_error, arg->on_target_error,
3129                            arg->has_unmap, arg->unmap,
3130                            NULL,
3131                            arg->has_copy_mode, arg->copy_mode,
3132                            arg->has_auto_finalize, arg->auto_finalize,
3133                            arg->has_auto_dismiss, arg->auto_dismiss,
3134                            errp);
3135     bdrv_unref(target_bs);
3136 out:
3137     aio_context_release(aio_context);
3138 }
3139 
3140 void qmp_blockdev_mirror(const char *job_id,
3141                          const char *device, const char *target,
3142                          const char *replaces,
3143                          MirrorSyncMode sync,
3144                          bool has_speed, int64_t speed,
3145                          bool has_granularity, uint32_t granularity,
3146                          bool has_buf_size, int64_t buf_size,
3147                          bool has_on_source_error,
3148                          BlockdevOnError on_source_error,
3149                          bool has_on_target_error,
3150                          BlockdevOnError on_target_error,
3151                          const char *filter_node_name,
3152                          bool has_copy_mode, MirrorCopyMode copy_mode,
3153                          bool has_auto_finalize, bool auto_finalize,
3154                          bool has_auto_dismiss, bool auto_dismiss,
3155                          Error **errp)
3156 {
3157     BlockDriverState *bs;
3158     BlockDriverState *target_bs;
3159     AioContext *aio_context;
3160     AioContext *old_context;
3161     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;
3162     bool zero_target;
3163     int ret;
3164 
3165     bs = qmp_get_root_bs(device, errp);
3166     if (!bs) {
3167         return;
3168     }
3169 
3170     target_bs = bdrv_lookup_bs(target, target, errp);
3171     if (!target_bs) {
3172         return;
3173     }
3174 
3175     zero_target = (sync == MIRROR_SYNC_MODE_FULL);
3176 
3177     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3178     old_context = bdrv_get_aio_context(target_bs);
3179     aio_context = bdrv_get_aio_context(bs);
3180     aio_context_acquire(old_context);
3181 
3182     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3183 
3184     aio_context_release(old_context);
3185     aio_context_acquire(aio_context);
3186 
3187     if (ret < 0) {
3188         goto out;
3189     }
3190 
3191     blockdev_mirror_common(job_id, bs, target_bs,
3192                            replaces, sync, backing_mode,
3193                            zero_target, has_speed, speed,
3194                            has_granularity, granularity,
3195                            has_buf_size, buf_size,
3196                            has_on_source_error, on_source_error,
3197                            has_on_target_error, on_target_error,
3198                            true, true, filter_node_name,
3199                            has_copy_mode, copy_mode,
3200                            has_auto_finalize, auto_finalize,
3201                            has_auto_dismiss, auto_dismiss,
3202                            errp);
3203 out:
3204     aio_context_release(aio_context);
3205 }
3206 
3207 /*
3208  * Get a block job using its ID. Called with job_mutex held.
3209  */
3210 static BlockJob *find_block_job_locked(const char *id, Error **errp)
3211 {
3212     BlockJob *job;
3213 
3214     assert(id != NULL);
3215 
3216     job = block_job_get_locked(id);
3217 
3218     if (!job) {
3219         error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
3220                   "Block job '%s' not found", id);
3221         return NULL;
3222     }
3223 
3224     return job;
3225 }
3226 
3227 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
3228 {
3229     BlockJob *job;
3230 
3231     JOB_LOCK_GUARD();
3232     job = find_block_job_locked(device, errp);
3233 
3234     if (!job) {
3235         return;
3236     }
3237 
3238     block_job_set_speed_locked(job, speed, errp);
3239 }
3240 
3241 void qmp_block_job_cancel(const char *device,
3242                           bool has_force, bool force, Error **errp)
3243 {
3244     BlockJob *job;
3245 
3246     JOB_LOCK_GUARD();
3247     job = find_block_job_locked(device, errp);
3248 
3249     if (!job) {
3250         return;
3251     }
3252 
3253     if (!has_force) {
3254         force = false;
3255     }
3256 
3257     if (job_user_paused_locked(&job->job) && !force) {
3258         error_setg(errp, "The block job for device '%s' is currently paused",
3259                    device);
3260         return;
3261     }
3262 
3263     trace_qmp_block_job_cancel(job);
3264     job_user_cancel_locked(&job->job, force, errp);
3265 }
3266 
3267 void qmp_block_job_pause(const char *device, Error **errp)
3268 {
3269     BlockJob *job;
3270 
3271     JOB_LOCK_GUARD();
3272     job = find_block_job_locked(device, errp);
3273 
3274     if (!job) {
3275         return;
3276     }
3277 
3278     trace_qmp_block_job_pause(job);
3279     job_user_pause_locked(&job->job, errp);
3280 }
3281 
3282 void qmp_block_job_resume(const char *device, Error **errp)
3283 {
3284     BlockJob *job;
3285 
3286     JOB_LOCK_GUARD();
3287     job = find_block_job_locked(device, errp);
3288 
3289     if (!job) {
3290         return;
3291     }
3292 
3293     trace_qmp_block_job_resume(job);
3294     job_user_resume_locked(&job->job, errp);
3295 }
3296 
3297 void qmp_block_job_complete(const char *device, Error **errp)
3298 {
3299     BlockJob *job;
3300 
3301     JOB_LOCK_GUARD();
3302     job = find_block_job_locked(device, errp);
3303 
3304     if (!job) {
3305         return;
3306     }
3307 
3308     trace_qmp_block_job_complete(job);
3309     job_complete_locked(&job->job, errp);
3310 }
3311 
3312 void qmp_block_job_finalize(const char *id, Error **errp)
3313 {
3314     BlockJob *job;
3315 
3316     JOB_LOCK_GUARD();
3317     job = find_block_job_locked(id, errp);
3318 
3319     if (!job) {
3320         return;
3321     }
3322 
3323     trace_qmp_block_job_finalize(job);
3324     job_ref_locked(&job->job);
3325     job_finalize_locked(&job->job, errp);
3326 
3327     job_unref_locked(&job->job);
3328 }
3329 
3330 void qmp_block_job_dismiss(const char *id, Error **errp)
3331 {
3332     BlockJob *bjob;
3333     Job *job;
3334 
3335     JOB_LOCK_GUARD();
3336     bjob = find_block_job_locked(id, errp);
3337 
3338     if (!bjob) {
3339         return;
3340     }
3341 
3342     trace_qmp_block_job_dismiss(bjob);
3343     job = &bjob->job;
3344     job_dismiss_locked(&job, errp);
3345 }
3346 
3347 void qmp_change_backing_file(const char *device,
3348                              const char *image_node_name,
3349                              const char *backing_file,
3350                              Error **errp)
3351 {
3352     BlockDriverState *bs = NULL;
3353     AioContext *aio_context;
3354     BlockDriverState *image_bs = NULL;
3355     Error *local_err = NULL;
3356     bool ro;
3357     int ret;
3358 
3359     bs = qmp_get_root_bs(device, errp);
3360     if (!bs) {
3361         return;
3362     }
3363 
3364     aio_context = bdrv_get_aio_context(bs);
3365     aio_context_acquire(aio_context);
3366 
3367     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
3368     if (local_err) {
3369         error_propagate(errp, local_err);
3370         goto out;
3371     }
3372 
3373     if (!image_bs) {
3374         error_setg(errp, "image file not found");
3375         goto out;
3376     }
3377 
3378     if (bdrv_find_base(image_bs) == image_bs) {
3379         error_setg(errp, "not allowing backing file change on an image "
3380                          "without a backing file");
3381         goto out;
3382     }
3383 
3384     /* even though we are not necessarily operating on bs, we need it to
3385      * determine if block ops are currently prohibited on the chain */
3386     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
3387         goto out;
3388     }
3389 
3390     /* final sanity check */
3391     if (!bdrv_chain_contains(bs, image_bs)) {
3392         error_setg(errp, "'%s' and image file are not in the same chain",
3393                    device);
3394         goto out;
3395     }
3396 
3397     /* if not r/w, reopen to make r/w */
3398     ro = bdrv_is_read_only(image_bs);
3399 
3400     if (ro) {
3401         if (bdrv_reopen_set_read_only(image_bs, false, errp) != 0) {
3402             goto out;
3403         }
3404     }
3405 
3406     ret = bdrv_change_backing_file(image_bs, backing_file,
3407                                    image_bs->drv ? image_bs->drv->format_name : "",
3408                                    false);
3409 
3410     if (ret < 0) {
3411         error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
3412                          backing_file);
3413         /* don't exit here, so we can try to restore open flags if
3414          * appropriate */
3415     }
3416 
3417     if (ro) {
3418         bdrv_reopen_set_read_only(image_bs, true, errp);
3419     }
3420 
3421 out:
3422     aio_context_release(aio_context);
3423 }
3424 
3425 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
3426 {
3427     BlockDriverState *bs;
3428     QObject *obj;
3429     Visitor *v = qobject_output_visitor_new(&obj);
3430     QDict *qdict;
3431 
3432     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3433     visit_complete(v, &obj);
3434     qdict = qobject_to(QDict, obj);
3435 
3436     qdict_flatten(qdict);
3437 
3438     if (!qdict_get_try_str(qdict, "node-name")) {
3439         error_setg(errp, "'node-name' must be specified for the root node");
3440         goto fail;
3441     }
3442 
3443     bs = bds_tree_init(qdict, errp);
3444     if (!bs) {
3445         goto fail;
3446     }
3447 
3448     bdrv_set_monitor_owned(bs);
3449 
3450 fail:
3451     visit_free(v);
3452 }
3453 
3454 void qmp_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
3455 {
3456     BlockReopenQueue *queue = NULL;
3457 
3458     /* Add each one of the BDS that we want to reopen to the queue */
3459     for (; reopen_list != NULL; reopen_list = reopen_list->next) {
3460         BlockdevOptions *options = reopen_list->value;
3461         BlockDriverState *bs;
3462         AioContext *ctx;
3463         QObject *obj;
3464         Visitor *v;
3465         QDict *qdict;
3466 
3467         /* Check for the selected node name */
3468         if (!options->node_name) {
3469             error_setg(errp, "node-name not specified");
3470             goto fail;
3471         }
3472 
3473         bs = bdrv_find_node(options->node_name);
3474         if (!bs) {
3475             error_setg(errp, "Failed to find node with node-name='%s'",
3476                        options->node_name);
3477             goto fail;
3478         }
3479 
3480         /* Put all options in a QDict and flatten it */
3481         v = qobject_output_visitor_new(&obj);
3482         visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3483         visit_complete(v, &obj);
3484         visit_free(v);
3485 
3486         qdict = qobject_to(QDict, obj);
3487 
3488         qdict_flatten(qdict);
3489 
3490         ctx = bdrv_get_aio_context(bs);
3491         aio_context_acquire(ctx);
3492 
3493         queue = bdrv_reopen_queue(queue, bs, qdict, false);
3494 
3495         aio_context_release(ctx);
3496     }
3497 
3498     /* Perform the reopen operation */
3499     bdrv_reopen_multiple(queue, errp);
3500     queue = NULL;
3501 
3502 fail:
3503     bdrv_reopen_queue_free(queue);
3504 }
3505 
3506 void qmp_blockdev_del(const char *node_name, Error **errp)
3507 {
3508     AioContext *aio_context;
3509     BlockDriverState *bs;
3510 
3511     GLOBAL_STATE_CODE();
3512 
3513     bs = bdrv_find_node(node_name);
3514     if (!bs) {
3515         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3516         return;
3517     }
3518     if (bdrv_has_blk(bs)) {
3519         error_setg(errp, "Node %s is in use", node_name);
3520         return;
3521     }
3522     aio_context = bdrv_get_aio_context(bs);
3523     aio_context_acquire(aio_context);
3524 
3525     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
3526         goto out;
3527     }
3528 
3529     if (!QTAILQ_IN_USE(bs, monitor_list)) {
3530         error_setg(errp, "Node %s is not owned by the monitor",
3531                    bs->node_name);
3532         goto out;
3533     }
3534 
3535     if (bs->refcnt > 1) {
3536         error_setg(errp, "Block device %s is in use",
3537                    bdrv_get_device_or_node_name(bs));
3538         goto out;
3539     }
3540 
3541     QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
3542     bdrv_unref(bs);
3543 
3544 out:
3545     aio_context_release(aio_context);
3546 }
3547 
3548 static BdrvChild * GRAPH_RDLOCK
3549 bdrv_find_child(BlockDriverState *parent_bs, const char *child_name)
3550 {
3551     BdrvChild *child;
3552 
3553     QLIST_FOREACH(child, &parent_bs->children, next) {
3554         if (strcmp(child->name, child_name) == 0) {
3555             return child;
3556         }
3557     }
3558 
3559     return NULL;
3560 }
3561 
3562 void qmp_x_blockdev_change(const char *parent, const char *child,
3563                            const char *node, Error **errp)
3564 {
3565     BlockDriverState *parent_bs, *new_bs = NULL;
3566     BdrvChild *p_child;
3567 
3568     bdrv_graph_wrlock(NULL);
3569 
3570     parent_bs = bdrv_lookup_bs(parent, parent, errp);
3571     if (!parent_bs) {
3572         goto out;
3573     }
3574 
3575     if (!child == !node) {
3576         if (child) {
3577             error_setg(errp, "The parameters child and node are in conflict");
3578         } else {
3579             error_setg(errp, "Either child or node must be specified");
3580         }
3581         goto out;
3582     }
3583 
3584     if (child) {
3585         p_child = bdrv_find_child(parent_bs, child);
3586         if (!p_child) {
3587             error_setg(errp, "Node '%s' does not have child '%s'",
3588                        parent, child);
3589             goto out;
3590         }
3591         bdrv_del_child(parent_bs, p_child, errp);
3592     }
3593 
3594     if (node) {
3595         new_bs = bdrv_find_node(node);
3596         if (!new_bs) {
3597             error_setg(errp, "Node '%s' not found", node);
3598             goto out;
3599         }
3600         bdrv_add_child(parent_bs, new_bs, errp);
3601     }
3602 
3603 out:
3604     bdrv_graph_wrunlock();
3605 }
3606 
3607 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
3608 {
3609     BlockJobInfoList *head = NULL, **tail = &head;
3610     BlockJob *job;
3611 
3612     JOB_LOCK_GUARD();
3613 
3614     for (job = block_job_next_locked(NULL); job;
3615          job = block_job_next_locked(job)) {
3616         BlockJobInfo *value;
3617 
3618         if (block_job_is_internal(job)) {
3619             continue;
3620         }
3621         value = block_job_query_locked(job, errp);
3622         if (!value) {
3623             qapi_free_BlockJobInfoList(head);
3624             return NULL;
3625         }
3626         QAPI_LIST_APPEND(tail, value);
3627     }
3628 
3629     return head;
3630 }
3631 
3632 void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
3633                                  bool has_force, bool force, Error **errp)
3634 {
3635     AioContext *old_context;
3636     AioContext *new_context;
3637     BlockDriverState *bs;
3638 
3639     bs = bdrv_find_node(node_name);
3640     if (!bs) {
3641         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3642         return;
3643     }
3644 
3645     /* Protects against accidents. */
3646     if (!(has_force && force) && bdrv_has_blk(bs)) {
3647         error_setg(errp, "Node %s is associated with a BlockBackend and could "
3648                          "be in use (use force=true to override this check)",
3649                          node_name);
3650         return;
3651     }
3652 
3653     if (iothread->type == QTYPE_QSTRING) {
3654         IOThread *obj = iothread_by_id(iothread->u.s);
3655         if (!obj) {
3656             error_setg(errp, "Cannot find iothread %s", iothread->u.s);
3657             return;
3658         }
3659 
3660         new_context = iothread_get_aio_context(obj);
3661     } else {
3662         new_context = qemu_get_aio_context();
3663     }
3664 
3665     old_context = bdrv_get_aio_context(bs);
3666     aio_context_acquire(old_context);
3667 
3668     bdrv_try_change_aio_context(bs, new_context, NULL, errp);
3669 
3670     aio_context_release(old_context);
3671 }
3672 
3673 QemuOptsList qemu_common_drive_opts = {
3674     .name = "drive",
3675     .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
3676     .desc = {
3677         {
3678             .name = "snapshot",
3679             .type = QEMU_OPT_BOOL,
3680             .help = "enable/disable snapshot mode",
3681         },{
3682             .name = "aio",
3683             .type = QEMU_OPT_STRING,
3684             .help = "host AIO implementation (threads, native, io_uring)",
3685         },{
3686             .name = BDRV_OPT_CACHE_WB,
3687             .type = QEMU_OPT_BOOL,
3688             .help = "Enable writeback mode",
3689         },{
3690             .name = "format",
3691             .type = QEMU_OPT_STRING,
3692             .help = "disk format (raw, qcow2, ...)",
3693         },{
3694             .name = "rerror",
3695             .type = QEMU_OPT_STRING,
3696             .help = "read error action",
3697         },{
3698             .name = "werror",
3699             .type = QEMU_OPT_STRING,
3700             .help = "write error action",
3701         },{
3702             .name = BDRV_OPT_READ_ONLY,
3703             .type = QEMU_OPT_BOOL,
3704             .help = "open drive file as read-only",
3705         },
3706 
3707         THROTTLE_OPTS,
3708 
3709         {
3710             .name = "throttling.group",
3711             .type = QEMU_OPT_STRING,
3712             .help = "name of the block throttling group",
3713         },{
3714             .name = "copy-on-read",
3715             .type = QEMU_OPT_BOOL,
3716             .help = "copy read data from backing file into image file",
3717         },{
3718             .name = "detect-zeroes",
3719             .type = QEMU_OPT_STRING,
3720             .help = "try to optimize zero writes (off, on, unmap)",
3721         },{
3722             .name = "stats-account-invalid",
3723             .type = QEMU_OPT_BOOL,
3724             .help = "whether to account for invalid I/O operations "
3725                     "in the statistics",
3726         },{
3727             .name = "stats-account-failed",
3728             .type = QEMU_OPT_BOOL,
3729             .help = "whether to account for failed I/O operations "
3730                     "in the statistics",
3731         },
3732         { /* end of list */ }
3733     },
3734 };
3735 
3736 QemuOptsList qemu_drive_opts = {
3737     .name = "drive",
3738     .head = QTAILQ_HEAD_INITIALIZER(qemu_drive_opts.head),
3739     .desc = {
3740         /*
3741          * no elements => accept any params
3742          * validation will happen later
3743          */
3744         { /* end of list */ }
3745     },
3746 };
3747