xref: /openbmc/qemu/blockdev.c (revision ea363626)
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     GRAPH_RDLOCK_GUARD_MAINLOOP();
1045 
1046     bs = bdrv_lookup_bs(name, name, errp);
1047     if (bs == NULL) {
1048         return NULL;
1049     }
1050 
1051     if (!bdrv_is_root_node(bs)) {
1052         error_setg(errp, "Need a root block node");
1053         return NULL;
1054     }
1055 
1056     aio_context = bdrv_get_aio_context(bs);
1057     aio_context_acquire(aio_context);
1058 
1059     if (!bdrv_is_inserted(bs)) {
1060         error_setg(errp, "Device has no medium");
1061         bs = NULL;
1062     }
1063 
1064     aio_context_release(aio_context);
1065 
1066     return bs;
1067 }
1068 
1069 static void blockdev_do_action(TransactionAction *action, Error **errp)
1070 {
1071     TransactionActionList list;
1072 
1073     list.value = action;
1074     list.next = NULL;
1075     qmp_transaction(&list, NULL, errp);
1076 }
1077 
1078 void qmp_blockdev_snapshot_sync(const char *device, const char *node_name,
1079                                 const char *snapshot_file,
1080                                 const char *snapshot_node_name,
1081                                 const char *format,
1082                                 bool has_mode, NewImageMode mode, Error **errp)
1083 {
1084     BlockdevSnapshotSync snapshot = {
1085         .device = (char *) device,
1086         .node_name = (char *) node_name,
1087         .snapshot_file = (char *) snapshot_file,
1088         .snapshot_node_name = (char *) snapshot_node_name,
1089         .format = (char *) format,
1090         .has_mode = has_mode,
1091         .mode = mode,
1092     };
1093     TransactionAction action = {
1094         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
1095         .u.blockdev_snapshot_sync.data = &snapshot,
1096     };
1097     blockdev_do_action(&action, errp);
1098 }
1099 
1100 void qmp_blockdev_snapshot(const char *node, const char *overlay,
1101                            Error **errp)
1102 {
1103     BlockdevSnapshot snapshot_data = {
1104         .node = (char *) node,
1105         .overlay = (char *) overlay
1106     };
1107     TransactionAction action = {
1108         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
1109         .u.blockdev_snapshot.data = &snapshot_data,
1110     };
1111     blockdev_do_action(&action, errp);
1112 }
1113 
1114 void qmp_blockdev_snapshot_internal_sync(const char *device,
1115                                          const char *name,
1116                                          Error **errp)
1117 {
1118     BlockdevSnapshotInternal snapshot = {
1119         .device = (char *) device,
1120         .name = (char *) name
1121     };
1122     TransactionAction action = {
1123         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
1124         .u.blockdev_snapshot_internal_sync.data = &snapshot,
1125     };
1126     blockdev_do_action(&action, errp);
1127 }
1128 
1129 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
1130                                                          const char *id,
1131                                                          const char *name,
1132                                                          Error **errp)
1133 {
1134     BlockDriverState *bs;
1135     AioContext *aio_context;
1136     QEMUSnapshotInfo sn;
1137     Error *local_err = NULL;
1138     SnapshotInfo *info = NULL;
1139     int ret;
1140 
1141     GLOBAL_STATE_CODE();
1142     GRAPH_RDLOCK_GUARD_MAINLOOP();
1143 
1144     bs = qmp_get_root_bs(device, errp);
1145     if (!bs) {
1146         return NULL;
1147     }
1148     aio_context = bdrv_get_aio_context(bs);
1149     aio_context_acquire(aio_context);
1150 
1151     if (!id && !name) {
1152         error_setg(errp, "Name or id must be provided");
1153         goto out_aio_context;
1154     }
1155 
1156     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
1157         goto out_aio_context;
1158     }
1159 
1160     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
1161     if (local_err) {
1162         error_propagate(errp, local_err);
1163         goto out_aio_context;
1164     }
1165     if (!ret) {
1166         error_setg(errp,
1167                    "Snapshot with id '%s' and name '%s' does not exist on "
1168                    "device '%s'",
1169                    STR_OR_NULL(id), STR_OR_NULL(name), device);
1170         goto out_aio_context;
1171     }
1172 
1173     bdrv_snapshot_delete(bs, id, name, &local_err);
1174     if (local_err) {
1175         error_propagate(errp, local_err);
1176         goto out_aio_context;
1177     }
1178 
1179     aio_context_release(aio_context);
1180 
1181     info = g_new0(SnapshotInfo, 1);
1182     info->id = g_strdup(sn.id_str);
1183     info->name = g_strdup(sn.name);
1184     info->date_nsec = sn.date_nsec;
1185     info->date_sec = sn.date_sec;
1186     info->vm_state_size = sn.vm_state_size;
1187     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
1188     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
1189     if (sn.icount != -1ULL) {
1190         info->icount = sn.icount;
1191         info->has_icount = true;
1192     }
1193 
1194     return info;
1195 
1196 out_aio_context:
1197     aio_context_release(aio_context);
1198     return NULL;
1199 }
1200 
1201 /* internal snapshot private data */
1202 typedef struct InternalSnapshotState {
1203     BlockDriverState *bs;
1204     QEMUSnapshotInfo sn;
1205     bool created;
1206 } InternalSnapshotState;
1207 
1208 static void internal_snapshot_abort(void *opaque);
1209 static void internal_snapshot_clean(void *opaque);
1210 TransactionActionDrv internal_snapshot_drv = {
1211     .abort = internal_snapshot_abort,
1212     .clean = internal_snapshot_clean,
1213 };
1214 
1215 static void internal_snapshot_action(BlockdevSnapshotInternal *internal,
1216                                      Transaction *tran, Error **errp)
1217 {
1218     Error *local_err = NULL;
1219     const char *device;
1220     const char *name;
1221     BlockDriverState *bs;
1222     QEMUSnapshotInfo old_sn, *sn;
1223     bool ret;
1224     int64_t rt;
1225     InternalSnapshotState *state = g_new0(InternalSnapshotState, 1);
1226     AioContext *aio_context;
1227     int ret1;
1228 
1229     GLOBAL_STATE_CODE();
1230     GRAPH_RDLOCK_GUARD_MAINLOOP();
1231 
1232     tran_add(tran, &internal_snapshot_drv, state);
1233 
1234     device = internal->device;
1235     name = internal->name;
1236 
1237     bs = qmp_get_root_bs(device, errp);
1238     if (!bs) {
1239         return;
1240     }
1241 
1242     aio_context = bdrv_get_aio_context(bs);
1243     aio_context_acquire(aio_context);
1244 
1245     state->bs = bs;
1246 
1247     /* Paired with .clean() */
1248     bdrv_drained_begin(bs);
1249 
1250     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
1251         goto out;
1252     }
1253 
1254     if (bdrv_is_read_only(bs)) {
1255         error_setg(errp, "Device '%s' is read only", device);
1256         goto out;
1257     }
1258 
1259     if (!bdrv_can_snapshot(bs)) {
1260         error_setg(errp, "Block format '%s' used by device '%s' "
1261                    "does not support internal snapshots",
1262                    bs->drv->format_name, device);
1263         goto out;
1264     }
1265 
1266     if (!strlen(name)) {
1267         error_setg(errp, "Name is empty");
1268         goto out;
1269     }
1270 
1271     /* check whether a snapshot with name exist */
1272     ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &old_sn,
1273                                             &local_err);
1274     if (local_err) {
1275         error_propagate(errp, local_err);
1276         goto out;
1277     } else if (ret) {
1278         error_setg(errp,
1279                    "Snapshot with name '%s' already exists on device '%s'",
1280                    name, device);
1281         goto out;
1282     }
1283 
1284     /* 3. take the snapshot */
1285     sn = &state->sn;
1286     pstrcpy(sn->name, sizeof(sn->name), name);
1287     rt = g_get_real_time();
1288     sn->date_sec = rt / G_USEC_PER_SEC;
1289     sn->date_nsec = (rt % G_USEC_PER_SEC) * 1000;
1290     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1291     if (replay_mode != REPLAY_MODE_NONE) {
1292         sn->icount = replay_get_current_icount();
1293     } else {
1294         sn->icount = -1ULL;
1295     }
1296 
1297     ret1 = bdrv_snapshot_create(bs, sn);
1298     if (ret1 < 0) {
1299         error_setg_errno(errp, -ret1,
1300                          "Failed to create snapshot '%s' on device '%s'",
1301                          name, device);
1302         goto out;
1303     }
1304 
1305     /* 4. succeed, mark a snapshot is created */
1306     state->created = true;
1307 
1308 out:
1309     aio_context_release(aio_context);
1310 }
1311 
1312 static void internal_snapshot_abort(void *opaque)
1313 {
1314     InternalSnapshotState *state = opaque;
1315     BlockDriverState *bs = state->bs;
1316     QEMUSnapshotInfo *sn = &state->sn;
1317     AioContext *aio_context;
1318     Error *local_error = NULL;
1319 
1320     GLOBAL_STATE_CODE();
1321     GRAPH_RDLOCK_GUARD_MAINLOOP();
1322 
1323     if (!state->created) {
1324         return;
1325     }
1326 
1327     aio_context = bdrv_get_aio_context(state->bs);
1328     aio_context_acquire(aio_context);
1329 
1330     if (bdrv_snapshot_delete(bs, sn->id_str, sn->name, &local_error) < 0) {
1331         error_reportf_err(local_error,
1332                           "Failed to delete snapshot with id '%s' and "
1333                           "name '%s' on device '%s' in abort: ",
1334                           sn->id_str, sn->name,
1335                           bdrv_get_device_name(bs));
1336     }
1337 
1338     aio_context_release(aio_context);
1339 }
1340 
1341 static void internal_snapshot_clean(void *opaque)
1342 {
1343     g_autofree InternalSnapshotState *state = opaque;
1344     AioContext *aio_context;
1345 
1346     if (!state->bs) {
1347         return;
1348     }
1349 
1350     aio_context = bdrv_get_aio_context(state->bs);
1351     aio_context_acquire(aio_context);
1352 
1353     bdrv_drained_end(state->bs);
1354 
1355     aio_context_release(aio_context);
1356 }
1357 
1358 /* external snapshot private data */
1359 typedef struct ExternalSnapshotState {
1360     BlockDriverState *old_bs;
1361     BlockDriverState *new_bs;
1362     bool overlay_appended;
1363 } ExternalSnapshotState;
1364 
1365 static void external_snapshot_commit(void *opaque);
1366 static void external_snapshot_abort(void *opaque);
1367 static void external_snapshot_clean(void *opaque);
1368 TransactionActionDrv external_snapshot_drv = {
1369     .commit = external_snapshot_commit,
1370     .abort = external_snapshot_abort,
1371     .clean = external_snapshot_clean,
1372 };
1373 
1374 static void external_snapshot_action(TransactionAction *action,
1375                                      Transaction *tran, Error **errp)
1376 {
1377     int ret;
1378     int flags = 0;
1379     QDict *options = NULL;
1380     Error *local_err = NULL;
1381     /* Device and node name of the image to generate the snapshot from */
1382     const char *device;
1383     const char *node_name;
1384     /* Reference to the new image (for 'blockdev-snapshot') */
1385     const char *snapshot_ref;
1386     /* File name of the new image (for 'blockdev-snapshot-sync') */
1387     const char *new_image_file;
1388     ExternalSnapshotState *state = g_new0(ExternalSnapshotState, 1);
1389     AioContext *aio_context;
1390     uint64_t perm, shared;
1391 
1392     /* TODO We'll eventually have to take a writer lock in this function */
1393     GRAPH_RDLOCK_GUARD_MAINLOOP();
1394 
1395     tran_add(tran, &external_snapshot_drv, state);
1396 
1397     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
1398      * purpose but a different set of parameters */
1399     switch (action->type) {
1400     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
1401         {
1402             BlockdevSnapshot *s = action->u.blockdev_snapshot.data;
1403             device = s->node;
1404             node_name = s->node;
1405             new_image_file = NULL;
1406             snapshot_ref = s->overlay;
1407         }
1408         break;
1409     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
1410         {
1411             BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1412             device = s->device;
1413             node_name = s->node_name;
1414             new_image_file = s->snapshot_file;
1415             snapshot_ref = NULL;
1416         }
1417         break;
1418     default:
1419         g_assert_not_reached();
1420     }
1421 
1422     /* start processing */
1423 
1424     state->old_bs = bdrv_lookup_bs(device, node_name, errp);
1425     if (!state->old_bs) {
1426         return;
1427     }
1428 
1429     aio_context = bdrv_get_aio_context(state->old_bs);
1430     aio_context_acquire(aio_context);
1431 
1432     /* Paired with .clean() */
1433     bdrv_drained_begin(state->old_bs);
1434 
1435     if (!bdrv_is_inserted(state->old_bs)) {
1436         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1437         goto out;
1438     }
1439 
1440     if (bdrv_op_is_blocked(state->old_bs,
1441                            BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
1442         goto out;
1443     }
1444 
1445     if (!bdrv_is_read_only(state->old_bs)) {
1446         if (bdrv_flush(state->old_bs)) {
1447             error_setg(errp, QERR_IO_ERROR);
1448             goto out;
1449         }
1450     }
1451 
1452     if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
1453         BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1454         const char *format = s->format ?: "qcow2";
1455         enum NewImageMode mode;
1456         const char *snapshot_node_name = s->snapshot_node_name;
1457 
1458         if (node_name && !snapshot_node_name) {
1459             error_setg(errp, "New overlay node-name missing");
1460             goto out;
1461         }
1462 
1463         if (snapshot_node_name &&
1464             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
1465             error_setg(errp, "New overlay node-name already in use");
1466             goto out;
1467         }
1468 
1469         flags = state->old_bs->open_flags;
1470         flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ);
1471         flags |= BDRV_O_NO_BACKING;
1472 
1473         /* create new image w/backing file */
1474         mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1475         if (mode != NEW_IMAGE_MODE_EXISTING) {
1476             int64_t size = bdrv_getlength(state->old_bs);
1477             if (size < 0) {
1478                 error_setg_errno(errp, -size, "bdrv_getlength failed");
1479                 goto out;
1480             }
1481             bdrv_refresh_filename(state->old_bs);
1482 
1483             aio_context_release(aio_context);
1484             bdrv_img_create(new_image_file, format,
1485                             state->old_bs->filename,
1486                             state->old_bs->drv->format_name,
1487                             NULL, size, flags, false, &local_err);
1488             aio_context_acquire(aio_context);
1489 
1490             if (local_err) {
1491                 error_propagate(errp, local_err);
1492                 goto out;
1493             }
1494         }
1495 
1496         options = qdict_new();
1497         if (snapshot_node_name) {
1498             qdict_put_str(options, "node-name", snapshot_node_name);
1499         }
1500         qdict_put_str(options, "driver", format);
1501     }
1502     aio_context_release(aio_context);
1503 
1504     aio_context_acquire(qemu_get_aio_context());
1505     state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags,
1506                               errp);
1507     aio_context_release(qemu_get_aio_context());
1508 
1509     /* We will manually add the backing_hd field to the bs later */
1510     if (!state->new_bs) {
1511         return;
1512     }
1513 
1514     aio_context_acquire(aio_context);
1515 
1516     /*
1517      * Allow attaching a backing file to an overlay that's already in use only
1518      * if the parents don't assume that they are already seeing a valid image.
1519      * (Specifically, allow it as a mirror target, which is write-only access.)
1520      */
1521     bdrv_get_cumulative_perm(state->new_bs, &perm, &shared);
1522     if (perm & BLK_PERM_CONSISTENT_READ) {
1523         error_setg(errp, "The overlay is already in use");
1524         goto out;
1525     }
1526 
1527     if (state->new_bs->drv->is_filter) {
1528         error_setg(errp, "Filters cannot be used as overlays");
1529         goto out;
1530     }
1531 
1532     if (bdrv_cow_child(state->new_bs)) {
1533         error_setg(errp, "The overlay already has a backing image");
1534         goto out;
1535     }
1536 
1537     if (!state->new_bs->drv->supports_backing) {
1538         error_setg(errp, "The overlay does not support backing images");
1539         goto out;
1540     }
1541 
1542     ret = bdrv_append(state->new_bs, state->old_bs, errp);
1543     if (ret < 0) {
1544         goto out;
1545     }
1546     state->overlay_appended = true;
1547 
1548 out:
1549     aio_context_release(aio_context);
1550 }
1551 
1552 static void external_snapshot_commit(void *opaque)
1553 {
1554     ExternalSnapshotState *state = opaque;
1555     AioContext *aio_context;
1556 
1557     aio_context = bdrv_get_aio_context(state->old_bs);
1558     aio_context_acquire(aio_context);
1559 
1560     /* We don't need (or want) to use the transactional
1561      * bdrv_reopen_multiple() across all the entries at once, because we
1562      * don't want to abort all of them if one of them fails the reopen */
1563     if (!qatomic_read(&state->old_bs->copy_on_read)) {
1564         bdrv_reopen_set_read_only(state->old_bs, true, NULL);
1565     }
1566 
1567     aio_context_release(aio_context);
1568 }
1569 
1570 static void external_snapshot_abort(void *opaque)
1571 {
1572     ExternalSnapshotState *state = opaque;
1573     if (state->new_bs) {
1574         if (state->overlay_appended) {
1575             AioContext *aio_context;
1576             AioContext *tmp_context;
1577             int ret;
1578 
1579             aio_context = bdrv_get_aio_context(state->old_bs);
1580             aio_context_acquire(aio_context);
1581 
1582             bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
1583                                           close state->old_bs; we need it */
1584             bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
1585 
1586             /*
1587              * The call to bdrv_set_backing_hd() above returns state->old_bs to
1588              * the main AioContext. As we're still going to be using it, return
1589              * it to the AioContext it was before.
1590              */
1591             tmp_context = bdrv_get_aio_context(state->old_bs);
1592             if (aio_context != tmp_context) {
1593                 aio_context_release(aio_context);
1594                 aio_context_acquire(tmp_context);
1595 
1596                 ret = bdrv_try_change_aio_context(state->old_bs,
1597                                                   aio_context, NULL, NULL);
1598                 assert(ret == 0);
1599 
1600                 aio_context_release(tmp_context);
1601                 aio_context_acquire(aio_context);
1602             }
1603 
1604             bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
1605             bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
1606 
1607             aio_context_release(aio_context);
1608         }
1609     }
1610 }
1611 
1612 static void external_snapshot_clean(void *opaque)
1613 {
1614     g_autofree ExternalSnapshotState *state = opaque;
1615     AioContext *aio_context;
1616 
1617     if (!state->old_bs) {
1618         return;
1619     }
1620 
1621     aio_context = bdrv_get_aio_context(state->old_bs);
1622     aio_context_acquire(aio_context);
1623 
1624     bdrv_drained_end(state->old_bs);
1625     bdrv_unref(state->new_bs);
1626 
1627     aio_context_release(aio_context);
1628 }
1629 
1630 typedef struct DriveBackupState {
1631     BlockDriverState *bs;
1632     BlockJob *job;
1633 } DriveBackupState;
1634 
1635 static BlockJob *do_backup_common(BackupCommon *backup,
1636                                   BlockDriverState *bs,
1637                                   BlockDriverState *target_bs,
1638                                   AioContext *aio_context,
1639                                   JobTxn *txn, Error **errp);
1640 
1641 static void drive_backup_commit(void *opaque);
1642 static void drive_backup_abort(void *opaque);
1643 static void drive_backup_clean(void *opaque);
1644 TransactionActionDrv drive_backup_drv = {
1645     .commit = drive_backup_commit,
1646     .abort = drive_backup_abort,
1647     .clean = drive_backup_clean,
1648 };
1649 
1650 static void drive_backup_action(DriveBackup *backup,
1651                                 JobTxn *block_job_txn,
1652                                 Transaction *tran, Error **errp)
1653 {
1654     DriveBackupState *state = g_new0(DriveBackupState, 1);
1655     BlockDriverState *bs;
1656     BlockDriverState *target_bs;
1657     BlockDriverState *source = NULL;
1658     AioContext *aio_context;
1659     AioContext *old_context;
1660     const char *format;
1661     QDict *options;
1662     Error *local_err = NULL;
1663     int flags;
1664     int64_t size;
1665     bool set_backing_hd = false;
1666     int ret;
1667 
1668     GLOBAL_STATE_CODE();
1669 
1670     tran_add(tran, &drive_backup_drv, state);
1671 
1672     if (!backup->has_mode) {
1673         backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1674     }
1675 
1676     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1677     if (!bs) {
1678         return;
1679     }
1680 
1681     if (!bs->drv) {
1682         error_setg(errp, "Device has no medium");
1683         return;
1684     }
1685 
1686     aio_context = bdrv_get_aio_context(bs);
1687     aio_context_acquire(aio_context);
1688 
1689     state->bs = bs;
1690     /* Paired with .clean() */
1691     bdrv_drained_begin(bs);
1692 
1693     format = backup->format;
1694     if (!format && backup->mode != NEW_IMAGE_MODE_EXISTING) {
1695         format = bs->drv->format_name;
1696     }
1697 
1698     /* Early check to avoid creating target */
1699     bdrv_graph_rdlock_main_loop();
1700     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
1701         bdrv_graph_rdunlock_main_loop();
1702         goto out;
1703     }
1704     bdrv_graph_rdunlock_main_loop();
1705 
1706     flags = bs->open_flags | BDRV_O_RDWR;
1707 
1708     /*
1709      * See if we have a backing HD we can use to create our new image
1710      * on top of.
1711      */
1712     if (backup->sync == MIRROR_SYNC_MODE_TOP) {
1713         /*
1714          * Backup will not replace the source by the target, so none
1715          * of the filters skipped here will be removed (in contrast to
1716          * mirror).  Therefore, we can skip all of them when looking
1717          * for the first COW relationship.
1718          */
1719         source = bdrv_cow_bs(bdrv_skip_filters(bs));
1720         if (!source) {
1721             backup->sync = MIRROR_SYNC_MODE_FULL;
1722         }
1723     }
1724     if (backup->sync == MIRROR_SYNC_MODE_NONE) {
1725         source = bs;
1726         flags |= BDRV_O_NO_BACKING;
1727         set_backing_hd = true;
1728     }
1729 
1730     size = bdrv_getlength(bs);
1731     if (size < 0) {
1732         error_setg_errno(errp, -size, "bdrv_getlength failed");
1733         goto out;
1734     }
1735 
1736     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
1737         assert(format);
1738         if (source) {
1739             /* Implicit filters should not appear in the filename */
1740             BlockDriverState *explicit_backing =
1741                 bdrv_skip_implicit_filters(source);
1742 
1743             bdrv_graph_rdlock_main_loop();
1744             bdrv_refresh_filename(explicit_backing);
1745             bdrv_graph_rdunlock_main_loop();
1746 
1747             bdrv_img_create(backup->target, format,
1748                             explicit_backing->filename,
1749                             explicit_backing->drv->format_name, NULL,
1750                             size, flags, false, &local_err);
1751         } else {
1752             bdrv_img_create(backup->target, format, NULL, NULL, NULL,
1753                             size, flags, false, &local_err);
1754         }
1755     }
1756 
1757     if (local_err) {
1758         error_propagate(errp, local_err);
1759         goto out;
1760     }
1761 
1762     options = qdict_new();
1763     qdict_put_str(options, "discard", "unmap");
1764     qdict_put_str(options, "detect-zeroes", "unmap");
1765     if (format) {
1766         qdict_put_str(options, "driver", format);
1767     }
1768     aio_context_release(aio_context);
1769 
1770     aio_context_acquire(qemu_get_aio_context());
1771     target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
1772     aio_context_release(qemu_get_aio_context());
1773 
1774     if (!target_bs) {
1775         return;
1776     }
1777 
1778     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1779     old_context = bdrv_get_aio_context(target_bs);
1780     aio_context_acquire(old_context);
1781 
1782     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1783     if (ret < 0) {
1784         bdrv_unref(target_bs);
1785         aio_context_release(old_context);
1786         return;
1787     }
1788 
1789     aio_context_release(old_context);
1790     aio_context_acquire(aio_context);
1791 
1792     if (set_backing_hd) {
1793         if (bdrv_set_backing_hd(target_bs, source, errp) < 0) {
1794             goto unref;
1795         }
1796     }
1797 
1798     state->job = do_backup_common(qapi_DriveBackup_base(backup),
1799                                   bs, target_bs, aio_context,
1800                                   block_job_txn, errp);
1801 
1802 unref:
1803     bdrv_unref(target_bs);
1804 out:
1805     aio_context_release(aio_context);
1806 }
1807 
1808 static void drive_backup_commit(void *opaque)
1809 {
1810     DriveBackupState *state = opaque;
1811     AioContext *aio_context;
1812 
1813     aio_context = bdrv_get_aio_context(state->bs);
1814     aio_context_acquire(aio_context);
1815 
1816     assert(state->job);
1817     job_start(&state->job->job);
1818 
1819     aio_context_release(aio_context);
1820 }
1821 
1822 static void drive_backup_abort(void *opaque)
1823 {
1824     DriveBackupState *state = opaque;
1825 
1826     if (state->job) {
1827         job_cancel_sync(&state->job->job, true);
1828     }
1829 }
1830 
1831 static void drive_backup_clean(void *opaque)
1832 {
1833     g_autofree DriveBackupState *state = opaque;
1834     AioContext *aio_context;
1835 
1836     if (!state->bs) {
1837         return;
1838     }
1839 
1840     aio_context = bdrv_get_aio_context(state->bs);
1841     aio_context_acquire(aio_context);
1842 
1843     bdrv_drained_end(state->bs);
1844 
1845     aio_context_release(aio_context);
1846 }
1847 
1848 typedef struct BlockdevBackupState {
1849     BlockDriverState *bs;
1850     BlockJob *job;
1851 } BlockdevBackupState;
1852 
1853 static void blockdev_backup_commit(void *opaque);
1854 static void blockdev_backup_abort(void *opaque);
1855 static void blockdev_backup_clean(void *opaque);
1856 TransactionActionDrv blockdev_backup_drv = {
1857     .commit = blockdev_backup_commit,
1858     .abort = blockdev_backup_abort,
1859     .clean = blockdev_backup_clean,
1860 };
1861 
1862 static void blockdev_backup_action(BlockdevBackup *backup,
1863                                    JobTxn *block_job_txn,
1864                                    Transaction *tran, Error **errp)
1865 {
1866     BlockdevBackupState *state = g_new0(BlockdevBackupState, 1);
1867     BlockDriverState *bs;
1868     BlockDriverState *target_bs;
1869     AioContext *aio_context;
1870     AioContext *old_context;
1871     int ret;
1872 
1873     tran_add(tran, &blockdev_backup_drv, state);
1874 
1875     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1876     if (!bs) {
1877         return;
1878     }
1879 
1880     target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);
1881     if (!target_bs) {
1882         return;
1883     }
1884 
1885     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
1886     aio_context = bdrv_get_aio_context(bs);
1887     old_context = bdrv_get_aio_context(target_bs);
1888     aio_context_acquire(old_context);
1889 
1890     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
1891     if (ret < 0) {
1892         aio_context_release(old_context);
1893         return;
1894     }
1895 
1896     aio_context_release(old_context);
1897     aio_context_acquire(aio_context);
1898     state->bs = bs;
1899 
1900     /* Paired with .clean() */
1901     bdrv_drained_begin(state->bs);
1902 
1903     state->job = do_backup_common(qapi_BlockdevBackup_base(backup),
1904                                   bs, target_bs, aio_context,
1905                                   block_job_txn, errp);
1906 
1907     aio_context_release(aio_context);
1908 }
1909 
1910 static void blockdev_backup_commit(void *opaque)
1911 {
1912     BlockdevBackupState *state = opaque;
1913     AioContext *aio_context;
1914 
1915     aio_context = bdrv_get_aio_context(state->bs);
1916     aio_context_acquire(aio_context);
1917 
1918     assert(state->job);
1919     job_start(&state->job->job);
1920 
1921     aio_context_release(aio_context);
1922 }
1923 
1924 static void blockdev_backup_abort(void *opaque)
1925 {
1926     BlockdevBackupState *state = opaque;
1927 
1928     if (state->job) {
1929         job_cancel_sync(&state->job->job, true);
1930     }
1931 }
1932 
1933 static void blockdev_backup_clean(void *opaque)
1934 {
1935     g_autofree BlockdevBackupState *state = opaque;
1936     AioContext *aio_context;
1937 
1938     if (!state->bs) {
1939         return;
1940     }
1941 
1942     aio_context = bdrv_get_aio_context(state->bs);
1943     aio_context_acquire(aio_context);
1944 
1945     bdrv_drained_end(state->bs);
1946 
1947     aio_context_release(aio_context);
1948 }
1949 
1950 typedef struct BlockDirtyBitmapState {
1951     BdrvDirtyBitmap *bitmap;
1952     BlockDriverState *bs;
1953     HBitmap *backup;
1954     bool was_enabled;
1955 } BlockDirtyBitmapState;
1956 
1957 static void block_dirty_bitmap_add_abort(void *opaque);
1958 TransactionActionDrv block_dirty_bitmap_add_drv = {
1959     .abort = block_dirty_bitmap_add_abort,
1960     .clean = g_free,
1961 };
1962 
1963 static void block_dirty_bitmap_add_action(BlockDirtyBitmapAdd *action,
1964                                           Transaction *tran, Error **errp)
1965 {
1966     Error *local_err = NULL;
1967     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
1968 
1969     tran_add(tran, &block_dirty_bitmap_add_drv, state);
1970 
1971     /* AIO context taken and released within qmp_block_dirty_bitmap_add */
1972     qmp_block_dirty_bitmap_add(action->node, action->name,
1973                                action->has_granularity, action->granularity,
1974                                action->has_persistent, action->persistent,
1975                                action->has_disabled, action->disabled,
1976                                &local_err);
1977 
1978     if (!local_err) {
1979         state->bitmap = block_dirty_bitmap_lookup(action->node, action->name,
1980                                                   NULL, &error_abort);
1981     } else {
1982         error_propagate(errp, local_err);
1983     }
1984 }
1985 
1986 static void block_dirty_bitmap_add_abort(void *opaque)
1987 {
1988     BlockDirtyBitmapState *state = opaque;
1989 
1990     if (state->bitmap) {
1991         bdrv_release_dirty_bitmap(state->bitmap);
1992     }
1993 }
1994 
1995 static void block_dirty_bitmap_restore(void *opaque);
1996 static void block_dirty_bitmap_free_backup(void *opaque);
1997 TransactionActionDrv block_dirty_bitmap_clear_drv = {
1998     .abort = block_dirty_bitmap_restore,
1999     .commit = block_dirty_bitmap_free_backup,
2000     .clean = g_free,
2001 };
2002 
2003 static void block_dirty_bitmap_clear_action(BlockDirtyBitmap *action,
2004                                             Transaction *tran, Error **errp)
2005 {
2006     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2007 
2008     tran_add(tran, &block_dirty_bitmap_clear_drv, state);
2009 
2010     state->bitmap = block_dirty_bitmap_lookup(action->node,
2011                                               action->name,
2012                                               &state->bs,
2013                                               errp);
2014     if (!state->bitmap) {
2015         return;
2016     }
2017 
2018     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_DEFAULT, errp)) {
2019         return;
2020     }
2021 
2022     bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
2023 }
2024 
2025 static void block_dirty_bitmap_restore(void *opaque)
2026 {
2027     BlockDirtyBitmapState *state = opaque;
2028 
2029     if (state->backup) {
2030         bdrv_restore_dirty_bitmap(state->bitmap, state->backup);
2031     }
2032 }
2033 
2034 static void block_dirty_bitmap_free_backup(void *opaque)
2035 {
2036     BlockDirtyBitmapState *state = opaque;
2037 
2038     hbitmap_free(state->backup);
2039 }
2040 
2041 static void block_dirty_bitmap_enable_abort(void *opaque);
2042 TransactionActionDrv block_dirty_bitmap_enable_drv = {
2043     .abort = block_dirty_bitmap_enable_abort,
2044     .clean = g_free,
2045 };
2046 
2047 static void block_dirty_bitmap_enable_action(BlockDirtyBitmap *action,
2048                                              Transaction *tran, Error **errp)
2049 {
2050     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2051 
2052     tran_add(tran, &block_dirty_bitmap_enable_drv, state);
2053 
2054     state->bitmap = block_dirty_bitmap_lookup(action->node,
2055                                               action->name,
2056                                               NULL,
2057                                               errp);
2058     if (!state->bitmap) {
2059         return;
2060     }
2061 
2062     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2063         return;
2064     }
2065 
2066     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2067     bdrv_enable_dirty_bitmap(state->bitmap);
2068 }
2069 
2070 static void block_dirty_bitmap_enable_abort(void *opaque)
2071 {
2072     BlockDirtyBitmapState *state = opaque;
2073 
2074     if (!state->was_enabled) {
2075         bdrv_disable_dirty_bitmap(state->bitmap);
2076     }
2077 }
2078 
2079 static void block_dirty_bitmap_disable_abort(void *opaque);
2080 TransactionActionDrv block_dirty_bitmap_disable_drv = {
2081     .abort = block_dirty_bitmap_disable_abort,
2082     .clean = g_free,
2083 };
2084 
2085 static void block_dirty_bitmap_disable_action(BlockDirtyBitmap *action,
2086                                               Transaction *tran, Error **errp)
2087 {
2088     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2089 
2090     tran_add(tran, &block_dirty_bitmap_disable_drv, state);
2091 
2092     state->bitmap = block_dirty_bitmap_lookup(action->node,
2093                                               action->name,
2094                                               NULL,
2095                                               errp);
2096     if (!state->bitmap) {
2097         return;
2098     }
2099 
2100     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2101         return;
2102     }
2103 
2104     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2105     bdrv_disable_dirty_bitmap(state->bitmap);
2106 }
2107 
2108 static void block_dirty_bitmap_disable_abort(void *opaque)
2109 {
2110     BlockDirtyBitmapState *state = opaque;
2111 
2112     if (state->was_enabled) {
2113         bdrv_enable_dirty_bitmap(state->bitmap);
2114     }
2115 }
2116 
2117 TransactionActionDrv block_dirty_bitmap_merge_drv = {
2118     .commit = block_dirty_bitmap_free_backup,
2119     .abort = block_dirty_bitmap_restore,
2120     .clean = g_free,
2121 };
2122 
2123 static void block_dirty_bitmap_merge_action(BlockDirtyBitmapMerge *action,
2124                                             Transaction *tran, Error **errp)
2125 {
2126     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2127 
2128     tran_add(tran, &block_dirty_bitmap_merge_drv, state);
2129 
2130     state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
2131                                              action->bitmaps, &state->backup,
2132                                              errp);
2133 }
2134 
2135 static void block_dirty_bitmap_remove_commit(void *opaque);
2136 static void block_dirty_bitmap_remove_abort(void *opaque);
2137 TransactionActionDrv block_dirty_bitmap_remove_drv = {
2138     .commit = block_dirty_bitmap_remove_commit,
2139     .abort = block_dirty_bitmap_remove_abort,
2140     .clean = g_free,
2141 };
2142 
2143 static void block_dirty_bitmap_remove_action(BlockDirtyBitmap *action,
2144                                              Transaction *tran, Error **errp)
2145 {
2146     BlockDirtyBitmapState *state = g_new0(BlockDirtyBitmapState, 1);
2147 
2148     tran_add(tran, &block_dirty_bitmap_remove_drv, state);
2149 
2150 
2151     state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
2152                                               false, &state->bs, errp);
2153     if (state->bitmap) {
2154         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
2155         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
2156     }
2157 }
2158 
2159 static void block_dirty_bitmap_remove_abort(void *opaque)
2160 {
2161     BlockDirtyBitmapState *state = opaque;
2162 
2163     if (state->bitmap) {
2164         bdrv_dirty_bitmap_skip_store(state->bitmap, false);
2165         bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2166     }
2167 }
2168 
2169 static void block_dirty_bitmap_remove_commit(void *opaque)
2170 {
2171     BlockDirtyBitmapState *state = opaque;
2172 
2173     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2174     bdrv_release_dirty_bitmap(state->bitmap);
2175 }
2176 
2177 static void abort_commit(void *opaque);
2178 TransactionActionDrv abort_drv = {
2179     .commit = abort_commit,
2180 };
2181 
2182 static void abort_action(Transaction *tran, Error **errp)
2183 {
2184     tran_add(tran, &abort_drv, NULL);
2185     error_setg(errp, "Transaction aborted using Abort action");
2186 }
2187 
2188 static void abort_commit(void *opaque)
2189 {
2190     g_assert_not_reached(); /* this action never succeeds */
2191 }
2192 
2193 static void transaction_action(TransactionAction *act, JobTxn *block_job_txn,
2194                                Transaction *tran, Error **errp)
2195 {
2196     switch (act->type) {
2197     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
2198     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
2199         external_snapshot_action(act, tran, errp);
2200         return;
2201     case TRANSACTION_ACTION_KIND_DRIVE_BACKUP:
2202         drive_backup_action(act->u.drive_backup.data,
2203                             block_job_txn, tran, errp);
2204         return;
2205     case TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP:
2206         blockdev_backup_action(act->u.blockdev_backup.data,
2207                                block_job_txn, tran, errp);
2208         return;
2209     case TRANSACTION_ACTION_KIND_ABORT:
2210         abort_action(tran, errp);
2211         return;
2212     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC:
2213         internal_snapshot_action(act->u.blockdev_snapshot_internal_sync.data,
2214                                  tran, errp);
2215         return;
2216     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD:
2217         block_dirty_bitmap_add_action(act->u.block_dirty_bitmap_add.data,
2218                                       tran, errp);
2219         return;
2220     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR:
2221         block_dirty_bitmap_clear_action(act->u.block_dirty_bitmap_clear.data,
2222                                         tran, errp);
2223         return;
2224     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE:
2225         block_dirty_bitmap_enable_action(act->u.block_dirty_bitmap_enable.data,
2226                                          tran, errp);
2227         return;
2228     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE:
2229         block_dirty_bitmap_disable_action(
2230                 act->u.block_dirty_bitmap_disable.data, tran, errp);
2231         return;
2232     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE:
2233         block_dirty_bitmap_merge_action(act->u.block_dirty_bitmap_merge.data,
2234                                         tran, errp);
2235         return;
2236     case TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_REMOVE:
2237         block_dirty_bitmap_remove_action(act->u.block_dirty_bitmap_remove.data,
2238                                          tran, errp);
2239         return;
2240     /*
2241      * Where are transactions for MIRROR, COMMIT and STREAM?
2242      * Although these blockjobs use transaction callbacks like the backup job,
2243      * these jobs do not necessarily adhere to transaction semantics.
2244      * These jobs may not fully undo all of their actions on abort, nor do they
2245      * necessarily work in transactions with more than one job in them.
2246      */
2247     case TRANSACTION_ACTION_KIND__MAX:
2248     default:
2249         g_assert_not_reached();
2250     };
2251 }
2252 
2253 
2254 /*
2255  * 'Atomic' group operations.  The operations are performed as a set, and if
2256  * any fail then we roll back all operations in the group.
2257  *
2258  * Always run under BQL.
2259  */
2260 void qmp_transaction(TransactionActionList *actions,
2261                      struct TransactionProperties *properties,
2262                      Error **errp)
2263 {
2264     TransactionActionList *act;
2265     JobTxn *block_job_txn = NULL;
2266     Error *local_err = NULL;
2267     Transaction *tran;
2268     ActionCompletionMode comp_mode =
2269         properties ? properties->completion_mode :
2270         ACTION_COMPLETION_MODE_INDIVIDUAL;
2271 
2272     GLOBAL_STATE_CODE();
2273 
2274     /* Does this transaction get canceled as a group on failure?
2275      * If not, we don't really need to make a JobTxn.
2276      */
2277     if (comp_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
2278         for (act = actions; act; act = act->next) {
2279             TransactionActionKind type = act->value->type;
2280 
2281             if (type != TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP &&
2282                 type != TRANSACTION_ACTION_KIND_DRIVE_BACKUP)
2283             {
2284                 error_setg(errp,
2285                            "Action '%s' does not support transaction property "
2286                            "completion-mode = %s",
2287                            TransactionActionKind_str(type),
2288                            ActionCompletionMode_str(comp_mode));
2289                 return;
2290             }
2291         }
2292 
2293         block_job_txn = job_txn_new();
2294     }
2295 
2296     /* drain all i/o before any operations */
2297     bdrv_drain_all();
2298 
2299     tran = tran_new();
2300 
2301     /* We don't do anything in this loop that commits us to the operations */
2302     for (act = actions; act; act = act->next) {
2303         transaction_action(act->value, block_job_txn, tran, &local_err);
2304         if (local_err) {
2305             error_propagate(errp, local_err);
2306             goto delete_and_fail;
2307         }
2308     }
2309 
2310     tran_commit(tran);
2311 
2312     /* success */
2313     goto exit;
2314 
2315 delete_and_fail:
2316     /* failure, and it is all-or-none; roll back all operations */
2317     tran_abort(tran);
2318 exit:
2319     job_txn_unref(block_job_txn);
2320 }
2321 
2322 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
2323                                                               const char *name,
2324                                                               Error **errp)
2325 {
2326     BdrvDirtyBitmap *bitmap;
2327     BlockDriverState *bs;
2328     BlockDirtyBitmapSha256 *ret = NULL;
2329     char *sha256;
2330 
2331     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
2332     if (!bitmap || !bs) {
2333         return NULL;
2334     }
2335 
2336     sha256 = bdrv_dirty_bitmap_sha256(bitmap, errp);
2337     if (sha256 == NULL) {
2338         return NULL;
2339     }
2340 
2341     ret = g_new(BlockDirtyBitmapSha256, 1);
2342     ret->sha256 = sha256;
2343 
2344     return ret;
2345 }
2346 
2347 void coroutine_fn qmp_block_resize(const char *device, const char *node_name,
2348                                    int64_t size, Error **errp)
2349 {
2350     Error *local_err = NULL;
2351     BlockBackend *blk;
2352     BlockDriverState *bs;
2353     AioContext *old_ctx;
2354 
2355     bs = bdrv_lookup_bs(device, node_name, &local_err);
2356     if (local_err) {
2357         error_propagate(errp, local_err);
2358         return;
2359     }
2360 
2361     if (size < 0) {
2362         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
2363         return;
2364     }
2365 
2366     bdrv_graph_co_rdlock();
2367     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
2368         error_setg(errp, QERR_DEVICE_IN_USE, device);
2369         bdrv_graph_co_rdunlock();
2370         return;
2371     }
2372     bdrv_graph_co_rdunlock();
2373 
2374     blk = blk_co_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, errp);
2375     if (!blk) {
2376         return;
2377     }
2378 
2379     bdrv_co_lock(bs);
2380     bdrv_drained_begin(bs);
2381     bdrv_co_unlock(bs);
2382 
2383     old_ctx = bdrv_co_enter(bs);
2384     blk_co_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
2385     bdrv_co_leave(bs, old_ctx);
2386 
2387     bdrv_co_lock(bs);
2388     bdrv_drained_end(bs);
2389     blk_co_unref(blk);
2390     bdrv_co_unlock(bs);
2391 }
2392 
2393 void qmp_block_stream(const char *job_id, const char *device,
2394                       const char *base,
2395                       const char *base_node,
2396                       const char *backing_file,
2397                       const char *bottom,
2398                       bool has_speed, int64_t speed,
2399                       bool has_on_error, BlockdevOnError on_error,
2400                       const char *filter_node_name,
2401                       bool has_auto_finalize, bool auto_finalize,
2402                       bool has_auto_dismiss, bool auto_dismiss,
2403                       Error **errp)
2404 {
2405     BlockDriverState *bs, *iter, *iter_end;
2406     BlockDriverState *base_bs = NULL;
2407     BlockDriverState *bottom_bs = NULL;
2408     AioContext *aio_context;
2409     Error *local_err = NULL;
2410     int job_flags = JOB_DEFAULT;
2411 
2412     GLOBAL_STATE_CODE();
2413 
2414     if (base && base_node) {
2415         error_setg(errp, "'base' and 'base-node' cannot be specified "
2416                    "at the same time");
2417         return;
2418     }
2419 
2420     if (base && bottom) {
2421         error_setg(errp, "'base' and 'bottom' cannot be specified "
2422                    "at the same time");
2423         return;
2424     }
2425 
2426     if (bottom && base_node) {
2427         error_setg(errp, "'bottom' and 'base-node' cannot be specified "
2428                    "at the same time");
2429         return;
2430     }
2431 
2432     if (!has_on_error) {
2433         on_error = BLOCKDEV_ON_ERROR_REPORT;
2434     }
2435 
2436     bs = bdrv_lookup_bs(device, device, errp);
2437     if (!bs) {
2438         return;
2439     }
2440 
2441     aio_context = bdrv_get_aio_context(bs);
2442     aio_context_acquire(aio_context);
2443 
2444     if (base) {
2445         base_bs = bdrv_find_backing_image(bs, base);
2446         if (base_bs == NULL) {
2447             error_setg(errp, "Can't find '%s' in the backing chain", base);
2448             goto out;
2449         }
2450         assert(bdrv_get_aio_context(base_bs) == aio_context);
2451     }
2452 
2453     if (base_node) {
2454         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2455         if (!base_bs) {
2456             goto out;
2457         }
2458         if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) {
2459             error_setg(errp, "Node '%s' is not a backing image of '%s'",
2460                        base_node, device);
2461             goto out;
2462         }
2463         assert(bdrv_get_aio_context(base_bs) == aio_context);
2464 
2465         bdrv_graph_rdlock_main_loop();
2466         bdrv_refresh_filename(base_bs);
2467         bdrv_graph_rdunlock_main_loop();
2468     }
2469 
2470     if (bottom) {
2471         bottom_bs = bdrv_lookup_bs(NULL, bottom, errp);
2472         if (!bottom_bs) {
2473             goto out;
2474         }
2475         if (!bottom_bs->drv) {
2476             error_setg(errp, "Node '%s' is not open", bottom);
2477             goto out;
2478         }
2479         if (bottom_bs->drv->is_filter) {
2480             error_setg(errp, "Node '%s' is a filter, use a non-filter node "
2481                        "as 'bottom'", bottom);
2482             goto out;
2483         }
2484         if (!bdrv_chain_contains(bs, bottom_bs)) {
2485             error_setg(errp, "Node '%s' is not in a chain starting from '%s'",
2486                        bottom, device);
2487             goto out;
2488         }
2489         assert(bdrv_get_aio_context(bottom_bs) == aio_context);
2490     }
2491 
2492     /*
2493      * Check for op blockers in the whole chain between bs and base (or bottom)
2494      */
2495     iter_end = bottom ? bdrv_filter_or_cow_bs(bottom_bs) : base_bs;
2496     bdrv_graph_rdlock_main_loop();
2497     for (iter = bs; iter && iter != iter_end;
2498          iter = bdrv_filter_or_cow_bs(iter))
2499     {
2500         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
2501             bdrv_graph_rdunlock_main_loop();
2502             goto out;
2503         }
2504     }
2505     bdrv_graph_rdunlock_main_loop();
2506 
2507     /* if we are streaming the entire chain, the result will have no backing
2508      * file, and specifying one is therefore an error */
2509     if (!base_bs && backing_file) {
2510         error_setg(errp, "backing file specified, but streaming the "
2511                          "entire chain");
2512         goto out;
2513     }
2514 
2515     if (has_auto_finalize && !auto_finalize) {
2516         job_flags |= JOB_MANUAL_FINALIZE;
2517     }
2518     if (has_auto_dismiss && !auto_dismiss) {
2519         job_flags |= JOB_MANUAL_DISMISS;
2520     }
2521 
2522     stream_start(job_id, bs, base_bs, backing_file,
2523                  bottom_bs, job_flags, has_speed ? speed : 0, on_error,
2524                  filter_node_name, &local_err);
2525     if (local_err) {
2526         error_propagate(errp, local_err);
2527         goto out;
2528     }
2529 
2530     trace_qmp_block_stream(bs);
2531 
2532 out:
2533     aio_context_release(aio_context);
2534 }
2535 
2536 void qmp_block_commit(const char *job_id, const char *device,
2537                       const char *base_node,
2538                       const char *base,
2539                       const char *top_node,
2540                       const char *top,
2541                       const char *backing_file,
2542                       bool has_speed, int64_t speed,
2543                       bool has_on_error, BlockdevOnError on_error,
2544                       const char *filter_node_name,
2545                       bool has_auto_finalize, bool auto_finalize,
2546                       bool has_auto_dismiss, bool auto_dismiss,
2547                       Error **errp)
2548 {
2549     BlockDriverState *bs;
2550     BlockDriverState *iter;
2551     BlockDriverState *base_bs, *top_bs;
2552     AioContext *aio_context;
2553     Error *local_err = NULL;
2554     int job_flags = JOB_DEFAULT;
2555     uint64_t top_perm, top_shared;
2556 
2557     /* TODO We'll eventually have to take a writer lock in this function */
2558     GRAPH_RDLOCK_GUARD_MAINLOOP();
2559 
2560     if (!has_speed) {
2561         speed = 0;
2562     }
2563     if (!has_on_error) {
2564         on_error = BLOCKDEV_ON_ERROR_REPORT;
2565     }
2566     if (has_auto_finalize && !auto_finalize) {
2567         job_flags |= JOB_MANUAL_FINALIZE;
2568     }
2569     if (has_auto_dismiss && !auto_dismiss) {
2570         job_flags |= JOB_MANUAL_DISMISS;
2571     }
2572 
2573     /* Important Note:
2574      *  libvirt relies on the DeviceNotFound error class in order to probe for
2575      *  live commit feature versions; for this to work, we must make sure to
2576      *  perform the device lookup before any generic errors that may occur in a
2577      *  scenario in which all optional arguments are omitted. */
2578     bs = qmp_get_root_bs(device, &local_err);
2579     if (!bs) {
2580         bs = bdrv_lookup_bs(device, device, NULL);
2581         if (!bs) {
2582             error_free(local_err);
2583             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
2584                       "Device '%s' not found", device);
2585         } else {
2586             error_propagate(errp, local_err);
2587         }
2588         return;
2589     }
2590 
2591     aio_context = bdrv_get_aio_context(bs);
2592     aio_context_acquire(aio_context);
2593 
2594     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
2595         goto out;
2596     }
2597 
2598     /* default top_bs is the active layer */
2599     top_bs = bs;
2600 
2601     if (top_node && top) {
2602         error_setg(errp, "'top-node' and 'top' are mutually exclusive");
2603         goto out;
2604     } else if (top_node) {
2605         top_bs = bdrv_lookup_bs(NULL, top_node, errp);
2606         if (top_bs == NULL) {
2607             goto out;
2608         }
2609         if (!bdrv_chain_contains(bs, top_bs)) {
2610             error_setg(errp, "'%s' is not in this backing file chain",
2611                        top_node);
2612             goto out;
2613         }
2614     } else if (top) {
2615         /* This strcmp() is just a shortcut, there is no need to
2616          * refresh @bs's filename.  If it mismatches,
2617          * bdrv_find_backing_image() will do the refresh and may still
2618          * return @bs. */
2619         if (strcmp(bs->filename, top) != 0) {
2620             top_bs = bdrv_find_backing_image(bs, top);
2621         }
2622     }
2623 
2624     if (top_bs == NULL) {
2625         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
2626         goto out;
2627     }
2628 
2629     assert(bdrv_get_aio_context(top_bs) == aio_context);
2630 
2631     if (base_node && base) {
2632         error_setg(errp, "'base-node' and 'base' are mutually exclusive");
2633         goto out;
2634     } else if (base_node) {
2635         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2636         if (base_bs == NULL) {
2637             goto out;
2638         }
2639         if (!bdrv_chain_contains(top_bs, base_bs)) {
2640             error_setg(errp, "'%s' is not in this backing file chain",
2641                        base_node);
2642             goto out;
2643         }
2644     } else if (base) {
2645         base_bs = bdrv_find_backing_image(top_bs, base);
2646         if (base_bs == NULL) {
2647             error_setg(errp, "Can't find '%s' in the backing chain", base);
2648             goto out;
2649         }
2650     } else {
2651         base_bs = bdrv_find_base(top_bs);
2652         if (base_bs == NULL) {
2653             error_setg(errp, "There is no backimg image");
2654             goto out;
2655         }
2656     }
2657 
2658     assert(bdrv_get_aio_context(base_bs) == aio_context);
2659 
2660     for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs);
2661          iter = bdrv_filter_or_cow_bs(iter))
2662     {
2663         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2664             goto out;
2665         }
2666     }
2667 
2668     /* Do not allow attempts to commit an image into itself */
2669     if (top_bs == base_bs) {
2670         error_setg(errp, "cannot commit an image into itself");
2671         goto out;
2672     }
2673 
2674     /*
2675      * Active commit is required if and only if someone has taken a
2676      * WRITE permission on the top node.  Historically, we have always
2677      * used active commit for top nodes, so continue that practice
2678      * lest we possibly break clients that rely on this behavior, e.g.
2679      * to later attach this node to a writing parent.
2680      * (Active commit is never really wrong.)
2681      */
2682     bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared);
2683     if (top_perm & BLK_PERM_WRITE ||
2684         bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs))
2685     {
2686         if (backing_file) {
2687             if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) {
2688                 error_setg(errp, "'backing-file' specified,"
2689                                  " but 'top' is the active layer");
2690             } else {
2691                 error_setg(errp, "'backing-file' specified, but 'top' has a "
2692                                  "writer on it");
2693             }
2694             goto out;
2695         }
2696         if (!job_id) {
2697             /*
2698              * Emulate here what block_job_create() does, because it
2699              * is possible that @bs != @top_bs (the block job should
2700              * be named after @bs, even if @top_bs is the actual
2701              * source)
2702              */
2703             job_id = bdrv_get_device_name(bs);
2704         }
2705         commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error,
2706                             filter_node_name, NULL, NULL, false, &local_err);
2707     } else {
2708         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
2709         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2710             goto out;
2711         }
2712         commit_start(job_id, bs, base_bs, top_bs, job_flags,
2713                      speed, on_error, backing_file,
2714                      filter_node_name, &local_err);
2715     }
2716     if (local_err != NULL) {
2717         error_propagate(errp, local_err);
2718         goto out;
2719     }
2720 
2721 out:
2722     aio_context_release(aio_context);
2723 }
2724 
2725 /* Common QMP interface for drive-backup and blockdev-backup */
2726 static BlockJob *do_backup_common(BackupCommon *backup,
2727                                   BlockDriverState *bs,
2728                                   BlockDriverState *target_bs,
2729                                   AioContext *aio_context,
2730                                   JobTxn *txn, Error **errp)
2731 {
2732     BlockJob *job = NULL;
2733     BdrvDirtyBitmap *bmap = NULL;
2734     BackupPerf perf = { .max_workers = 64 };
2735     int job_flags = JOB_DEFAULT;
2736 
2737     if (!backup->has_speed) {
2738         backup->speed = 0;
2739     }
2740     if (!backup->has_on_source_error) {
2741         backup->on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2742     }
2743     if (!backup->has_on_target_error) {
2744         backup->on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2745     }
2746     if (!backup->has_auto_finalize) {
2747         backup->auto_finalize = true;
2748     }
2749     if (!backup->has_auto_dismiss) {
2750         backup->auto_dismiss = true;
2751     }
2752     if (!backup->has_compress) {
2753         backup->compress = false;
2754     }
2755 
2756     if (backup->x_perf) {
2757         if (backup->x_perf->has_use_copy_range) {
2758             perf.use_copy_range = backup->x_perf->use_copy_range;
2759         }
2760         if (backup->x_perf->has_max_workers) {
2761             perf.max_workers = backup->x_perf->max_workers;
2762         }
2763         if (backup->x_perf->has_max_chunk) {
2764             perf.max_chunk = backup->x_perf->max_chunk;
2765         }
2766     }
2767 
2768     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||
2769         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
2770         /* done before desugaring 'incremental' to print the right message */
2771         if (!backup->bitmap) {
2772             error_setg(errp, "must provide a valid bitmap name for "
2773                        "'%s' sync mode", MirrorSyncMode_str(backup->sync));
2774             return NULL;
2775         }
2776     }
2777 
2778     if (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL) {
2779         if (backup->has_bitmap_mode &&
2780             backup->bitmap_mode != BITMAP_SYNC_MODE_ON_SUCCESS) {
2781             error_setg(errp, "Bitmap sync mode must be '%s' "
2782                        "when using sync mode '%s'",
2783                        BitmapSyncMode_str(BITMAP_SYNC_MODE_ON_SUCCESS),
2784                        MirrorSyncMode_str(backup->sync));
2785             return NULL;
2786         }
2787         backup->has_bitmap_mode = true;
2788         backup->sync = MIRROR_SYNC_MODE_BITMAP;
2789         backup->bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
2790     }
2791 
2792     if (backup->bitmap) {
2793         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
2794         if (!bmap) {
2795             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
2796             return NULL;
2797         }
2798         if (!backup->has_bitmap_mode) {
2799             error_setg(errp, "Bitmap sync mode must be given "
2800                        "when providing a bitmap");
2801             return NULL;
2802         }
2803         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2804             return NULL;
2805         }
2806 
2807         /* This does not produce a useful bitmap artifact: */
2808         if (backup->sync == MIRROR_SYNC_MODE_NONE) {
2809             error_setg(errp, "sync mode '%s' does not produce meaningful bitmap"
2810                        " outputs", MirrorSyncMode_str(backup->sync));
2811             return NULL;
2812         }
2813 
2814         /* If the bitmap isn't used for input or output, this is useless: */
2815         if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER &&
2816             backup->sync != MIRROR_SYNC_MODE_BITMAP) {
2817             error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect"
2818                        " when combined with sync mode '%s'",
2819                        BitmapSyncMode_str(backup->bitmap_mode),
2820                        MirrorSyncMode_str(backup->sync));
2821             return NULL;
2822         }
2823     }
2824 
2825     if (!backup->bitmap && backup->has_bitmap_mode) {
2826         error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
2827         return NULL;
2828     }
2829 
2830     if (!backup->auto_finalize) {
2831         job_flags |= JOB_MANUAL_FINALIZE;
2832     }
2833     if (!backup->auto_dismiss) {
2834         job_flags |= JOB_MANUAL_DISMISS;
2835     }
2836 
2837     job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
2838                             backup->sync, bmap, backup->bitmap_mode,
2839                             backup->compress,
2840                             backup->filter_node_name,
2841                             &perf,
2842                             backup->on_source_error,
2843                             backup->on_target_error,
2844                             job_flags, NULL, NULL, txn, errp);
2845     return job;
2846 }
2847 
2848 void qmp_drive_backup(DriveBackup *backup, Error **errp)
2849 {
2850     TransactionAction action = {
2851         .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
2852         .u.drive_backup.data = backup,
2853     };
2854     blockdev_do_action(&action, errp);
2855 }
2856 
2857 BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
2858                                                  bool flat,
2859                                                  Error **errp)
2860 {
2861     bool return_flat = has_flat && flat;
2862 
2863     return bdrv_named_nodes_list(return_flat, errp);
2864 }
2865 
2866 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
2867 {
2868     GRAPH_RDLOCK_GUARD_MAINLOOP();
2869 
2870     return bdrv_get_xdbg_block_graph(errp);
2871 }
2872 
2873 void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)
2874 {
2875     TransactionAction action = {
2876         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,
2877         .u.blockdev_backup.data = backup,
2878     };
2879     blockdev_do_action(&action, errp);
2880 }
2881 
2882 /* Parameter check and block job starting for drive mirroring.
2883  * Caller should hold @device and @target's aio context (must be the same).
2884  **/
2885 static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
2886                                    BlockDriverState *target,
2887                                    const char *replaces,
2888                                    enum MirrorSyncMode sync,
2889                                    BlockMirrorBackingMode backing_mode,
2890                                    bool zero_target,
2891                                    bool has_speed, int64_t speed,
2892                                    bool has_granularity, uint32_t granularity,
2893                                    bool has_buf_size, int64_t buf_size,
2894                                    bool has_on_source_error,
2895                                    BlockdevOnError on_source_error,
2896                                    bool has_on_target_error,
2897                                    BlockdevOnError on_target_error,
2898                                    bool has_unmap, bool unmap,
2899                                    const char *filter_node_name,
2900                                    bool has_copy_mode, MirrorCopyMode copy_mode,
2901                                    bool has_auto_finalize, bool auto_finalize,
2902                                    bool has_auto_dismiss, bool auto_dismiss,
2903                                    Error **errp)
2904 {
2905     BlockDriverState *unfiltered_bs;
2906     int job_flags = JOB_DEFAULT;
2907 
2908     GLOBAL_STATE_CODE();
2909     GRAPH_RDLOCK_GUARD_MAINLOOP();
2910 
2911     if (!has_speed) {
2912         speed = 0;
2913     }
2914     if (!has_on_source_error) {
2915         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2916     }
2917     if (!has_on_target_error) {
2918         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2919     }
2920     if (!has_granularity) {
2921         granularity = 0;
2922     }
2923     if (!has_buf_size) {
2924         buf_size = 0;
2925     }
2926     if (!has_unmap) {
2927         unmap = true;
2928     }
2929     if (!has_copy_mode) {
2930         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
2931     }
2932     if (has_auto_finalize && !auto_finalize) {
2933         job_flags |= JOB_MANUAL_FINALIZE;
2934     }
2935     if (has_auto_dismiss && !auto_dismiss) {
2936         job_flags |= JOB_MANUAL_DISMISS;
2937     }
2938 
2939     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
2940         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2941                    "a value in range [512B, 64MB]");
2942         return;
2943     }
2944     if (granularity & (granularity - 1)) {
2945         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2946                    "a power of 2");
2947         return;
2948     }
2949 
2950     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2951         return;
2952     }
2953     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
2954         return;
2955     }
2956 
2957     if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) {
2958         sync = MIRROR_SYNC_MODE_FULL;
2959     }
2960 
2961     if (!replaces) {
2962         /* We want to mirror from @bs, but keep implicit filters on top */
2963         unfiltered_bs = bdrv_skip_implicit_filters(bs);
2964         if (unfiltered_bs != bs) {
2965             replaces = unfiltered_bs->node_name;
2966         }
2967     }
2968 
2969     if (replaces) {
2970         BlockDriverState *to_replace_bs;
2971         AioContext *aio_context;
2972         AioContext *replace_aio_context;
2973         int64_t bs_size, replace_size;
2974 
2975         bs_size = bdrv_getlength(bs);
2976         if (bs_size < 0) {
2977             error_setg_errno(errp, -bs_size, "Failed to query device's size");
2978             return;
2979         }
2980 
2981         to_replace_bs = check_to_replace_node(bs, replaces, errp);
2982         if (!to_replace_bs) {
2983             return;
2984         }
2985 
2986         aio_context = bdrv_get_aio_context(bs);
2987         replace_aio_context = bdrv_get_aio_context(to_replace_bs);
2988         /*
2989          * bdrv_getlength() is a co-wrapper and uses AIO_WAIT_WHILE. Be sure not
2990          * to acquire the same AioContext twice.
2991          */
2992         if (replace_aio_context != aio_context) {
2993             aio_context_acquire(replace_aio_context);
2994         }
2995         replace_size = bdrv_getlength(to_replace_bs);
2996         if (replace_aio_context != aio_context) {
2997             aio_context_release(replace_aio_context);
2998         }
2999 
3000         if (replace_size < 0) {
3001             error_setg_errno(errp, -replace_size,
3002                              "Failed to query the replacement node's size");
3003             return;
3004         }
3005         if (bs_size != replace_size) {
3006             error_setg(errp, "cannot replace image with a mirror image of "
3007                              "different size");
3008             return;
3009         }
3010     }
3011 
3012     /* pass the node name to replace to mirror start since it's loose coupling
3013      * and will allow to check whether the node still exist at mirror completion
3014      */
3015     mirror_start(job_id, bs, target,
3016                  replaces, job_flags,
3017                  speed, granularity, buf_size, sync, backing_mode, zero_target,
3018                  on_source_error, on_target_error, unmap, filter_node_name,
3019                  copy_mode, errp);
3020 }
3021 
3022 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
3023 {
3024     BlockDriverState *bs;
3025     BlockDriverState *target_backing_bs, *target_bs;
3026     AioContext *aio_context;
3027     AioContext *old_context;
3028     BlockMirrorBackingMode backing_mode;
3029     Error *local_err = NULL;
3030     QDict *options = NULL;
3031     int flags;
3032     int64_t size;
3033     const char *format = arg->format;
3034     bool zero_target;
3035     int ret;
3036 
3037     bs = qmp_get_root_bs(arg->device, errp);
3038     if (!bs) {
3039         return;
3040     }
3041 
3042     /* Early check to avoid creating target */
3043     bdrv_graph_rdlock_main_loop();
3044     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
3045         bdrv_graph_rdunlock_main_loop();
3046         return;
3047     }
3048     bdrv_graph_rdunlock_main_loop();
3049 
3050     aio_context = bdrv_get_aio_context(bs);
3051     aio_context_acquire(aio_context);
3052 
3053     if (!arg->has_mode) {
3054         arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
3055     }
3056 
3057     if (!arg->format) {
3058         format = (arg->mode == NEW_IMAGE_MODE_EXISTING
3059                   ? NULL : bs->drv->format_name);
3060     }
3061 
3062     flags = bs->open_flags | BDRV_O_RDWR;
3063     target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs));
3064     if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) {
3065         arg->sync = MIRROR_SYNC_MODE_FULL;
3066     }
3067     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
3068         target_backing_bs = bs;
3069     }
3070 
3071     size = bdrv_getlength(bs);
3072     if (size < 0) {
3073         error_setg_errno(errp, -size, "bdrv_getlength failed");
3074         goto out;
3075     }
3076 
3077     if (arg->replaces) {
3078         if (!arg->node_name) {
3079             error_setg(errp, "a node-name must be provided when replacing a"
3080                              " named node of the graph");
3081             goto out;
3082         }
3083     }
3084 
3085     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
3086         backing_mode = MIRROR_SOURCE_BACKING_CHAIN;
3087     } else {
3088         backing_mode = MIRROR_OPEN_BACKING_CHAIN;
3089     }
3090 
3091     /* Don't open backing image in create() */
3092     flags |= BDRV_O_NO_BACKING;
3093 
3094     if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs)
3095         && arg->mode != NEW_IMAGE_MODE_EXISTING)
3096     {
3097         /* create new image w/o backing file */
3098         assert(format);
3099         bdrv_img_create(arg->target, format,
3100                         NULL, NULL, NULL, size, flags, false, &local_err);
3101     } else {
3102         /* Implicit filters should not appear in the filename */
3103         BlockDriverState *explicit_backing =
3104             bdrv_skip_implicit_filters(target_backing_bs);
3105 
3106         switch (arg->mode) {
3107         case NEW_IMAGE_MODE_EXISTING:
3108             break;
3109         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
3110             /* create new image with backing file */
3111             bdrv_graph_rdlock_main_loop();
3112             bdrv_refresh_filename(explicit_backing);
3113             bdrv_graph_rdunlock_main_loop();
3114 
3115             bdrv_img_create(arg->target, format,
3116                             explicit_backing->filename,
3117                             explicit_backing->drv->format_name,
3118                             NULL, size, flags, false, &local_err);
3119             break;
3120         default:
3121             abort();
3122         }
3123     }
3124 
3125     if (local_err) {
3126         error_propagate(errp, local_err);
3127         goto out;
3128     }
3129 
3130     options = qdict_new();
3131     if (arg->node_name) {
3132         qdict_put_str(options, "node-name", arg->node_name);
3133     }
3134     if (format) {
3135         qdict_put_str(options, "driver", format);
3136     }
3137     aio_context_release(aio_context);
3138 
3139     /* Mirroring takes care of copy-on-write using the source's backing
3140      * file.
3141      */
3142     aio_context_acquire(qemu_get_aio_context());
3143     target_bs = bdrv_open(arg->target, NULL, options, flags, errp);
3144     aio_context_release(qemu_get_aio_context());
3145 
3146     if (!target_bs) {
3147         return;
3148     }
3149 
3150     zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
3151                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||
3152                     !bdrv_has_zero_init(target_bs)));
3153 
3154 
3155     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3156     old_context = bdrv_get_aio_context(target_bs);
3157     aio_context_acquire(old_context);
3158 
3159     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3160     if (ret < 0) {
3161         bdrv_unref(target_bs);
3162         aio_context_release(old_context);
3163         return;
3164     }
3165 
3166     aio_context_release(old_context);
3167     aio_context_acquire(aio_context);
3168 
3169     blockdev_mirror_common(arg->job_id, bs, target_bs,
3170                            arg->replaces, arg->sync,
3171                            backing_mode, zero_target,
3172                            arg->has_speed, arg->speed,
3173                            arg->has_granularity, arg->granularity,
3174                            arg->has_buf_size, arg->buf_size,
3175                            arg->has_on_source_error, arg->on_source_error,
3176                            arg->has_on_target_error, arg->on_target_error,
3177                            arg->has_unmap, arg->unmap,
3178                            NULL,
3179                            arg->has_copy_mode, arg->copy_mode,
3180                            arg->has_auto_finalize, arg->auto_finalize,
3181                            arg->has_auto_dismiss, arg->auto_dismiss,
3182                            errp);
3183     bdrv_unref(target_bs);
3184 out:
3185     aio_context_release(aio_context);
3186 }
3187 
3188 void qmp_blockdev_mirror(const char *job_id,
3189                          const char *device, const char *target,
3190                          const char *replaces,
3191                          MirrorSyncMode sync,
3192                          bool has_speed, int64_t speed,
3193                          bool has_granularity, uint32_t granularity,
3194                          bool has_buf_size, int64_t buf_size,
3195                          bool has_on_source_error,
3196                          BlockdevOnError on_source_error,
3197                          bool has_on_target_error,
3198                          BlockdevOnError on_target_error,
3199                          const char *filter_node_name,
3200                          bool has_copy_mode, MirrorCopyMode copy_mode,
3201                          bool has_auto_finalize, bool auto_finalize,
3202                          bool has_auto_dismiss, bool auto_dismiss,
3203                          Error **errp)
3204 {
3205     BlockDriverState *bs;
3206     BlockDriverState *target_bs;
3207     AioContext *aio_context;
3208     AioContext *old_context;
3209     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;
3210     bool zero_target;
3211     int ret;
3212 
3213     bs = qmp_get_root_bs(device, errp);
3214     if (!bs) {
3215         return;
3216     }
3217 
3218     target_bs = bdrv_lookup_bs(target, target, errp);
3219     if (!target_bs) {
3220         return;
3221     }
3222 
3223     zero_target = (sync == MIRROR_SYNC_MODE_FULL);
3224 
3225     /* Honor bdrv_try_change_aio_context() context acquisition requirements. */
3226     old_context = bdrv_get_aio_context(target_bs);
3227     aio_context = bdrv_get_aio_context(bs);
3228     aio_context_acquire(old_context);
3229 
3230     ret = bdrv_try_change_aio_context(target_bs, aio_context, NULL, errp);
3231 
3232     aio_context_release(old_context);
3233     aio_context_acquire(aio_context);
3234 
3235     if (ret < 0) {
3236         goto out;
3237     }
3238 
3239     blockdev_mirror_common(job_id, bs, target_bs,
3240                            replaces, sync, backing_mode,
3241                            zero_target, has_speed, speed,
3242                            has_granularity, granularity,
3243                            has_buf_size, buf_size,
3244                            has_on_source_error, on_source_error,
3245                            has_on_target_error, on_target_error,
3246                            true, true, filter_node_name,
3247                            has_copy_mode, copy_mode,
3248                            has_auto_finalize, auto_finalize,
3249                            has_auto_dismiss, auto_dismiss,
3250                            errp);
3251 out:
3252     aio_context_release(aio_context);
3253 }
3254 
3255 /*
3256  * Get a block job using its ID. Called with job_mutex held.
3257  */
3258 static BlockJob *find_block_job_locked(const char *id, Error **errp)
3259 {
3260     BlockJob *job;
3261 
3262     assert(id != NULL);
3263 
3264     job = block_job_get_locked(id);
3265 
3266     if (!job) {
3267         error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
3268                   "Block job '%s' not found", id);
3269         return NULL;
3270     }
3271 
3272     return job;
3273 }
3274 
3275 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
3276 {
3277     BlockJob *job;
3278 
3279     JOB_LOCK_GUARD();
3280     job = find_block_job_locked(device, errp);
3281 
3282     if (!job) {
3283         return;
3284     }
3285 
3286     block_job_set_speed_locked(job, speed, errp);
3287 }
3288 
3289 void qmp_block_job_cancel(const char *device,
3290                           bool has_force, bool force, Error **errp)
3291 {
3292     BlockJob *job;
3293 
3294     JOB_LOCK_GUARD();
3295     job = find_block_job_locked(device, errp);
3296 
3297     if (!job) {
3298         return;
3299     }
3300 
3301     if (!has_force) {
3302         force = false;
3303     }
3304 
3305     if (job_user_paused_locked(&job->job) && !force) {
3306         error_setg(errp, "The block job for device '%s' is currently paused",
3307                    device);
3308         return;
3309     }
3310 
3311     trace_qmp_block_job_cancel(job);
3312     job_user_cancel_locked(&job->job, force, errp);
3313 }
3314 
3315 void qmp_block_job_pause(const char *device, Error **errp)
3316 {
3317     BlockJob *job;
3318 
3319     JOB_LOCK_GUARD();
3320     job = find_block_job_locked(device, errp);
3321 
3322     if (!job) {
3323         return;
3324     }
3325 
3326     trace_qmp_block_job_pause(job);
3327     job_user_pause_locked(&job->job, errp);
3328 }
3329 
3330 void qmp_block_job_resume(const char *device, Error **errp)
3331 {
3332     BlockJob *job;
3333 
3334     JOB_LOCK_GUARD();
3335     job = find_block_job_locked(device, errp);
3336 
3337     if (!job) {
3338         return;
3339     }
3340 
3341     trace_qmp_block_job_resume(job);
3342     job_user_resume_locked(&job->job, errp);
3343 }
3344 
3345 void qmp_block_job_complete(const char *device, Error **errp)
3346 {
3347     BlockJob *job;
3348 
3349     JOB_LOCK_GUARD();
3350     job = find_block_job_locked(device, errp);
3351 
3352     if (!job) {
3353         return;
3354     }
3355 
3356     trace_qmp_block_job_complete(job);
3357     job_complete_locked(&job->job, errp);
3358 }
3359 
3360 void qmp_block_job_finalize(const char *id, Error **errp)
3361 {
3362     BlockJob *job;
3363 
3364     JOB_LOCK_GUARD();
3365     job = find_block_job_locked(id, errp);
3366 
3367     if (!job) {
3368         return;
3369     }
3370 
3371     trace_qmp_block_job_finalize(job);
3372     job_ref_locked(&job->job);
3373     job_finalize_locked(&job->job, errp);
3374 
3375     job_unref_locked(&job->job);
3376 }
3377 
3378 void qmp_block_job_dismiss(const char *id, Error **errp)
3379 {
3380     BlockJob *bjob;
3381     Job *job;
3382 
3383     JOB_LOCK_GUARD();
3384     bjob = find_block_job_locked(id, errp);
3385 
3386     if (!bjob) {
3387         return;
3388     }
3389 
3390     trace_qmp_block_job_dismiss(bjob);
3391     job = &bjob->job;
3392     job_dismiss_locked(&job, errp);
3393 }
3394 
3395 void qmp_block_job_change(BlockJobChangeOptions *opts, Error **errp)
3396 {
3397     BlockJob *job;
3398 
3399     JOB_LOCK_GUARD();
3400     job = find_block_job_locked(opts->id, errp);
3401 
3402     if (!job) {
3403         return;
3404     }
3405 
3406     block_job_change_locked(job, opts, errp);
3407 }
3408 
3409 void qmp_change_backing_file(const char *device,
3410                              const char *image_node_name,
3411                              const char *backing_file,
3412                              Error **errp)
3413 {
3414     BlockDriverState *bs = NULL;
3415     AioContext *aio_context;
3416     BlockDriverState *image_bs = NULL;
3417     Error *local_err = NULL;
3418     bool ro;
3419     int ret;
3420 
3421     bs = qmp_get_root_bs(device, errp);
3422     if (!bs) {
3423         return;
3424     }
3425 
3426     aio_context = bdrv_get_aio_context(bs);
3427     aio_context_acquire(aio_context);
3428 
3429     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
3430     if (local_err) {
3431         error_propagate(errp, local_err);
3432         goto out;
3433     }
3434 
3435     if (!image_bs) {
3436         error_setg(errp, "image file not found");
3437         goto out;
3438     }
3439 
3440     if (bdrv_find_base(image_bs) == image_bs) {
3441         error_setg(errp, "not allowing backing file change on an image "
3442                          "without a backing file");
3443         goto out;
3444     }
3445 
3446     /* even though we are not necessarily operating on bs, we need it to
3447      * determine if block ops are currently prohibited on the chain */
3448     bdrv_graph_rdlock_main_loop();
3449     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
3450         bdrv_graph_rdunlock_main_loop();
3451         goto out;
3452     }
3453     bdrv_graph_rdunlock_main_loop();
3454 
3455     /* final sanity check */
3456     if (!bdrv_chain_contains(bs, image_bs)) {
3457         error_setg(errp, "'%s' and image file are not in the same chain",
3458                    device);
3459         goto out;
3460     }
3461 
3462     /* if not r/w, reopen to make r/w */
3463     ro = bdrv_is_read_only(image_bs);
3464 
3465     if (ro) {
3466         if (bdrv_reopen_set_read_only(image_bs, false, errp) != 0) {
3467             goto out;
3468         }
3469     }
3470 
3471     ret = bdrv_change_backing_file(image_bs, backing_file,
3472                                    image_bs->drv ? image_bs->drv->format_name : "",
3473                                    false);
3474 
3475     if (ret < 0) {
3476         error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
3477                          backing_file);
3478         /* don't exit here, so we can try to restore open flags if
3479          * appropriate */
3480     }
3481 
3482     if (ro) {
3483         bdrv_reopen_set_read_only(image_bs, true, errp);
3484     }
3485 
3486 out:
3487     aio_context_release(aio_context);
3488 }
3489 
3490 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
3491 {
3492     BlockDriverState *bs;
3493     QObject *obj;
3494     Visitor *v = qobject_output_visitor_new(&obj);
3495     QDict *qdict;
3496 
3497     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3498     visit_complete(v, &obj);
3499     qdict = qobject_to(QDict, obj);
3500 
3501     qdict_flatten(qdict);
3502 
3503     if (!qdict_get_try_str(qdict, "node-name")) {
3504         error_setg(errp, "'node-name' must be specified for the root node");
3505         goto fail;
3506     }
3507 
3508     bs = bds_tree_init(qdict, errp);
3509     if (!bs) {
3510         goto fail;
3511     }
3512 
3513     bdrv_set_monitor_owned(bs);
3514 
3515 fail:
3516     visit_free(v);
3517 }
3518 
3519 void qmp_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
3520 {
3521     BlockReopenQueue *queue = NULL;
3522 
3523     /* Add each one of the BDS that we want to reopen to the queue */
3524     for (; reopen_list != NULL; reopen_list = reopen_list->next) {
3525         BlockdevOptions *options = reopen_list->value;
3526         BlockDriverState *bs;
3527         AioContext *ctx;
3528         QObject *obj;
3529         Visitor *v;
3530         QDict *qdict;
3531 
3532         /* Check for the selected node name */
3533         if (!options->node_name) {
3534             error_setg(errp, "node-name not specified");
3535             goto fail;
3536         }
3537 
3538         bs = bdrv_find_node(options->node_name);
3539         if (!bs) {
3540             error_setg(errp, "Failed to find node with node-name='%s'",
3541                        options->node_name);
3542             goto fail;
3543         }
3544 
3545         /* Put all options in a QDict and flatten it */
3546         v = qobject_output_visitor_new(&obj);
3547         visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3548         visit_complete(v, &obj);
3549         visit_free(v);
3550 
3551         qdict = qobject_to(QDict, obj);
3552 
3553         qdict_flatten(qdict);
3554 
3555         ctx = bdrv_get_aio_context(bs);
3556         aio_context_acquire(ctx);
3557 
3558         queue = bdrv_reopen_queue(queue, bs, qdict, false);
3559 
3560         aio_context_release(ctx);
3561     }
3562 
3563     /* Perform the reopen operation */
3564     bdrv_reopen_multiple(queue, errp);
3565     queue = NULL;
3566 
3567 fail:
3568     bdrv_reopen_queue_free(queue);
3569 }
3570 
3571 void qmp_blockdev_del(const char *node_name, Error **errp)
3572 {
3573     AioContext *aio_context;
3574     BlockDriverState *bs;
3575 
3576     GLOBAL_STATE_CODE();
3577     GRAPH_RDLOCK_GUARD_MAINLOOP();
3578 
3579     bs = bdrv_find_node(node_name);
3580     if (!bs) {
3581         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3582         return;
3583     }
3584     if (bdrv_has_blk(bs)) {
3585         error_setg(errp, "Node %s is in use", node_name);
3586         return;
3587     }
3588     aio_context = bdrv_get_aio_context(bs);
3589     aio_context_acquire(aio_context);
3590 
3591     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
3592         goto out;
3593     }
3594 
3595     if (!QTAILQ_IN_USE(bs, monitor_list)) {
3596         error_setg(errp, "Node %s is not owned by the monitor",
3597                    bs->node_name);
3598         goto out;
3599     }
3600 
3601     if (bs->refcnt > 1) {
3602         error_setg(errp, "Block device %s is in use",
3603                    bdrv_get_device_or_node_name(bs));
3604         goto out;
3605     }
3606 
3607     QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
3608     bdrv_unref(bs);
3609 
3610 out:
3611     aio_context_release(aio_context);
3612 }
3613 
3614 static BdrvChild * GRAPH_RDLOCK
3615 bdrv_find_child(BlockDriverState *parent_bs, const char *child_name)
3616 {
3617     BdrvChild *child;
3618 
3619     QLIST_FOREACH(child, &parent_bs->children, next) {
3620         if (strcmp(child->name, child_name) == 0) {
3621             return child;
3622         }
3623     }
3624 
3625     return NULL;
3626 }
3627 
3628 void qmp_x_blockdev_change(const char *parent, const char *child,
3629                            const char *node, Error **errp)
3630 {
3631     BlockDriverState *parent_bs, *new_bs = NULL;
3632     BdrvChild *p_child;
3633 
3634     bdrv_graph_wrlock(NULL);
3635 
3636     parent_bs = bdrv_lookup_bs(parent, parent, errp);
3637     if (!parent_bs) {
3638         goto out;
3639     }
3640 
3641     if (!child == !node) {
3642         if (child) {
3643             error_setg(errp, "The parameters child and node are in conflict");
3644         } else {
3645             error_setg(errp, "Either child or node must be specified");
3646         }
3647         goto out;
3648     }
3649 
3650     if (child) {
3651         p_child = bdrv_find_child(parent_bs, child);
3652         if (!p_child) {
3653             error_setg(errp, "Node '%s' does not have child '%s'",
3654                        parent, child);
3655             goto out;
3656         }
3657         bdrv_del_child(parent_bs, p_child, errp);
3658     }
3659 
3660     if (node) {
3661         new_bs = bdrv_find_node(node);
3662         if (!new_bs) {
3663             error_setg(errp, "Node '%s' not found", node);
3664             goto out;
3665         }
3666         bdrv_add_child(parent_bs, new_bs, errp);
3667     }
3668 
3669 out:
3670     bdrv_graph_wrunlock();
3671 }
3672 
3673 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
3674 {
3675     BlockJobInfoList *head = NULL, **tail = &head;
3676     BlockJob *job;
3677 
3678     JOB_LOCK_GUARD();
3679 
3680     for (job = block_job_next_locked(NULL); job;
3681          job = block_job_next_locked(job)) {
3682         BlockJobInfo *value;
3683 
3684         if (block_job_is_internal(job)) {
3685             continue;
3686         }
3687         value = block_job_query_locked(job, errp);
3688         if (!value) {
3689             qapi_free_BlockJobInfoList(head);
3690             return NULL;
3691         }
3692         QAPI_LIST_APPEND(tail, value);
3693     }
3694 
3695     return head;
3696 }
3697 
3698 void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
3699                                  bool has_force, bool force, Error **errp)
3700 {
3701     AioContext *old_context;
3702     AioContext *new_context;
3703     BlockDriverState *bs;
3704 
3705     GRAPH_RDLOCK_GUARD_MAINLOOP();
3706 
3707     bs = bdrv_find_node(node_name);
3708     if (!bs) {
3709         error_setg(errp, "Failed to find node with node-name='%s'", node_name);
3710         return;
3711     }
3712 
3713     /* Protects against accidents. */
3714     if (!(has_force && force) && bdrv_has_blk(bs)) {
3715         error_setg(errp, "Node %s is associated with a BlockBackend and could "
3716                          "be in use (use force=true to override this check)",
3717                          node_name);
3718         return;
3719     }
3720 
3721     if (iothread->type == QTYPE_QSTRING) {
3722         IOThread *obj = iothread_by_id(iothread->u.s);
3723         if (!obj) {
3724             error_setg(errp, "Cannot find iothread %s", iothread->u.s);
3725             return;
3726         }
3727 
3728         new_context = iothread_get_aio_context(obj);
3729     } else {
3730         new_context = qemu_get_aio_context();
3731     }
3732 
3733     old_context = bdrv_get_aio_context(bs);
3734     aio_context_acquire(old_context);
3735 
3736     bdrv_try_change_aio_context(bs, new_context, NULL, errp);
3737 
3738     aio_context_release(old_context);
3739 }
3740 
3741 QemuOptsList qemu_common_drive_opts = {
3742     .name = "drive",
3743     .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
3744     .desc = {
3745         {
3746             .name = "snapshot",
3747             .type = QEMU_OPT_BOOL,
3748             .help = "enable/disable snapshot mode",
3749         },{
3750             .name = "aio",
3751             .type = QEMU_OPT_STRING,
3752             .help = "host AIO implementation (threads, native, io_uring)",
3753         },{
3754             .name = BDRV_OPT_CACHE_WB,
3755             .type = QEMU_OPT_BOOL,
3756             .help = "Enable writeback mode",
3757         },{
3758             .name = "format",
3759             .type = QEMU_OPT_STRING,
3760             .help = "disk format (raw, qcow2, ...)",
3761         },{
3762             .name = "rerror",
3763             .type = QEMU_OPT_STRING,
3764             .help = "read error action",
3765         },{
3766             .name = "werror",
3767             .type = QEMU_OPT_STRING,
3768             .help = "write error action",
3769         },{
3770             .name = BDRV_OPT_READ_ONLY,
3771             .type = QEMU_OPT_BOOL,
3772             .help = "open drive file as read-only",
3773         },
3774 
3775         THROTTLE_OPTS,
3776 
3777         {
3778             .name = "throttling.group",
3779             .type = QEMU_OPT_STRING,
3780             .help = "name of the block throttling group",
3781         },{
3782             .name = "copy-on-read",
3783             .type = QEMU_OPT_BOOL,
3784             .help = "copy read data from backing file into image file",
3785         },{
3786             .name = "detect-zeroes",
3787             .type = QEMU_OPT_STRING,
3788             .help = "try to optimize zero writes (off, on, unmap)",
3789         },{
3790             .name = "stats-account-invalid",
3791             .type = QEMU_OPT_BOOL,
3792             .help = "whether to account for invalid I/O operations "
3793                     "in the statistics",
3794         },{
3795             .name = "stats-account-failed",
3796             .type = QEMU_OPT_BOOL,
3797             .help = "whether to account for failed I/O operations "
3798                     "in the statistics",
3799         },
3800         { /* end of list */ }
3801     },
3802 };
3803 
3804 QemuOptsList qemu_drive_opts = {
3805     .name = "drive",
3806     .head = QTAILQ_HEAD_INITIALIZER(qemu_drive_opts.head),
3807     .desc = {
3808         /*
3809          * no elements => accept any params
3810          * validation will happen later
3811          */
3812         { /* end of list */ }
3813     },
3814 };
3815