xref: /openbmc/qemu/blockdev.c (revision 55567891)
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/qdict.h"
39 #include "block/throttle-groups.h"
40 #include "monitor/monitor.h"
41 #include "qemu/error-report.h"
42 #include "qemu/option.h"
43 #include "qemu/qemu-print.h"
44 #include "qemu/config-file.h"
45 #include "qapi/qapi-commands-block.h"
46 #include "qapi/qapi-commands-transaction.h"
47 #include "qapi/qapi-visit-block-core.h"
48 #include "qapi/qmp/qdict.h"
49 #include "qapi/qmp/qnum.h"
50 #include "qapi/qmp/qstring.h"
51 #include "qapi/error.h"
52 #include "qapi/qmp/qerror.h"
53 #include "qapi/qmp/qlist.h"
54 #include "qapi/qobject-output-visitor.h"
55 #include "sysemu/sysemu.h"
56 #include "sysemu/iothread.h"
57 #include "block/block_int.h"
58 #include "block/trace.h"
59 #include "sysemu/arch_init.h"
60 #include "sysemu/qtest.h"
61 #include "sysemu/runstate.h"
62 #include "sysemu/replay.h"
63 #include "qemu/cutils.h"
64 #include "qemu/help_option.h"
65 #include "qemu/main-loop.h"
66 #include "qemu/throttle-options.h"
67 
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     QTAILQ_INSERT_TAIL(&monitor_bdrv_states, bs, monitor_list);
74 }
75 
76 static const char *const if_name[IF_COUNT] = {
77     [IF_NONE] = "none",
78     [IF_IDE] = "ide",
79     [IF_SCSI] = "scsi",
80     [IF_FLOPPY] = "floppy",
81     [IF_PFLASH] = "pflash",
82     [IF_MTD] = "mtd",
83     [IF_SD] = "sd",
84     [IF_VIRTIO] = "virtio",
85     [IF_XEN] = "xen",
86 };
87 
88 static int if_max_devs[IF_COUNT] = {
89     /*
90      * Do not change these numbers!  They govern how drive option
91      * index maps to unit and bus.  That mapping is ABI.
92      *
93      * All controllers used to implement if=T drives need to support
94      * if_max_devs[T] units, for any T with if_max_devs[T] != 0.
95      * Otherwise, some index values map to "impossible" bus, unit
96      * values.
97      *
98      * For instance, if you change [IF_SCSI] to 255, -drive
99      * if=scsi,index=12 no longer means bus=1,unit=5, but
100      * bus=0,unit=12.  With an lsi53c895a controller (7 units max),
101      * the drive can't be set up.  Regression.
102      */
103     [IF_IDE] = 2,
104     [IF_SCSI] = 7,
105 };
106 
107 /**
108  * Boards may call this to offer board-by-board overrides
109  * of the default, global values.
110  */
111 void override_max_devs(BlockInterfaceType type, int max_devs)
112 {
113     BlockBackend *blk;
114     DriveInfo *dinfo;
115 
116     if (max_devs <= 0) {
117         return;
118     }
119 
120     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
121         dinfo = blk_legacy_dinfo(blk);
122         if (dinfo->type == type) {
123             fprintf(stderr, "Cannot override units-per-bus property of"
124                     " the %s interface, because a drive of that type has"
125                     " already been added.\n", if_name[type]);
126             g_assert_not_reached();
127         }
128     }
129 
130     if_max_devs[type] = max_devs;
131 }
132 
133 /*
134  * We automatically delete the drive when a device using it gets
135  * unplugged.  Questionable feature, but we can't just drop it.
136  * Device models call blockdev_mark_auto_del() to schedule the
137  * automatic deletion, and generic qdev code calls blockdev_auto_del()
138  * when deletion is actually safe.
139  */
140 void blockdev_mark_auto_del(BlockBackend *blk)
141 {
142     DriveInfo *dinfo = blk_legacy_dinfo(blk);
143     BlockJob *job;
144 
145     if (!dinfo) {
146         return;
147     }
148 
149     for (job = block_job_next(NULL); job; job = block_job_next(job)) {
150         if (block_job_has_bdrv(job, blk_bs(blk))) {
151             AioContext *aio_context = job->job.aio_context;
152             aio_context_acquire(aio_context);
153 
154             job_cancel(&job->job, false);
155 
156             aio_context_release(aio_context);
157         }
158     }
159 
160     dinfo->auto_del = 1;
161 }
162 
163 void blockdev_auto_del(BlockBackend *blk)
164 {
165     DriveInfo *dinfo = blk_legacy_dinfo(blk);
166 
167     if (dinfo && dinfo->auto_del) {
168         monitor_remove_blk(blk);
169         blk_unref(blk);
170     }
171 }
172 
173 /**
174  * Returns the current mapping of how many units per bus
175  * a particular interface can support.
176  *
177  *  A positive integer indicates n units per bus.
178  *  0 implies the mapping has not been established.
179  * -1 indicates an invalid BlockInterfaceType was given.
180  */
181 int drive_get_max_devs(BlockInterfaceType type)
182 {
183     if (type >= IF_IDE && type < IF_COUNT) {
184         return if_max_devs[type];
185     }
186 
187     return -1;
188 }
189 
190 static int drive_index_to_bus_id(BlockInterfaceType type, int index)
191 {
192     int max_devs = if_max_devs[type];
193     return max_devs ? index / max_devs : 0;
194 }
195 
196 static int drive_index_to_unit_id(BlockInterfaceType type, int index)
197 {
198     int max_devs = if_max_devs[type];
199     return max_devs ? index % max_devs : index;
200 }
201 
202 QemuOpts *drive_def(const char *optstr)
203 {
204     return qemu_opts_parse_noisily(qemu_find_opts("drive"), optstr, false);
205 }
206 
207 QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
208                     const char *optstr)
209 {
210     QemuOpts *opts;
211 
212     opts = drive_def(optstr);
213     if (!opts) {
214         return NULL;
215     }
216     if (type != IF_DEFAULT) {
217         qemu_opt_set(opts, "if", if_name[type], &error_abort);
218     }
219     if (index >= 0) {
220         qemu_opt_set_number(opts, "index", index, &error_abort);
221     }
222     if (file)
223         qemu_opt_set(opts, "file", file, &error_abort);
224     return opts;
225 }
226 
227 DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
228 {
229     BlockBackend *blk;
230     DriveInfo *dinfo;
231 
232     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
233         dinfo = blk_legacy_dinfo(blk);
234         if (dinfo && dinfo->type == type
235             && dinfo->bus == bus && dinfo->unit == unit) {
236             return dinfo;
237         }
238     }
239 
240     return NULL;
241 }
242 
243 void drive_mark_claimed_by_board(void)
244 {
245     BlockBackend *blk;
246     DriveInfo *dinfo;
247 
248     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
249         dinfo = blk_legacy_dinfo(blk);
250         if (dinfo && blk_get_attached_dev(blk)) {
251             dinfo->claimed_by_board = true;
252         }
253     }
254 }
255 
256 void drive_check_orphaned(void)
257 {
258     BlockBackend *blk;
259     DriveInfo *dinfo;
260     Location loc;
261     bool orphans = false;
262 
263     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
264         dinfo = blk_legacy_dinfo(blk);
265         if (dinfo->is_default || dinfo->type == IF_NONE) {
266             continue;
267         }
268         if (!blk_get_attached_dev(blk)) {
269             loc_push_none(&loc);
270             qemu_opts_loc_restore(dinfo->opts);
271             error_report("machine type does not support"
272                          " if=%s,bus=%d,unit=%d",
273                          if_name[dinfo->type], dinfo->bus, dinfo->unit);
274             loc_pop(&loc);
275             orphans = true;
276             continue;
277         }
278         if (!dinfo->claimed_by_board && dinfo->type != IF_VIRTIO) {
279             loc_push_none(&loc);
280             qemu_opts_loc_restore(dinfo->opts);
281             warn_report("bogus if=%s is deprecated, use if=none",
282                         if_name[dinfo->type]);
283             loc_pop(&loc);
284         }
285     }
286 
287     if (orphans) {
288         exit(1);
289     }
290 }
291 
292 DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
293 {
294     return drive_get(type,
295                      drive_index_to_bus_id(type, index),
296                      drive_index_to_unit_id(type, index));
297 }
298 
299 int drive_get_max_bus(BlockInterfaceType type)
300 {
301     int max_bus;
302     BlockBackend *blk;
303     DriveInfo *dinfo;
304 
305     max_bus = -1;
306     for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
307         dinfo = blk_legacy_dinfo(blk);
308         if (dinfo && dinfo->type == type && dinfo->bus > max_bus) {
309             max_bus = dinfo->bus;
310         }
311     }
312     return max_bus;
313 }
314 
315 /* Get a block device.  This should only be used for single-drive devices
316    (e.g. SD/Floppy/MTD).  Multi-disk devices (scsi/ide) should use the
317    appropriate bus.  */
318 DriveInfo *drive_get_next(BlockInterfaceType type)
319 {
320     static int next_block_unit[IF_COUNT];
321 
322     return drive_get(type, 0, next_block_unit[type]++);
323 }
324 
325 static void bdrv_format_print(void *opaque, const char *name)
326 {
327     qemu_printf(" %s", name);
328 }
329 
330 typedef struct {
331     QEMUBH *bh;
332     BlockDriverState *bs;
333 } BDRVPutRefBH;
334 
335 static int parse_block_error_action(const char *buf, bool is_read, Error **errp)
336 {
337     if (!strcmp(buf, "ignore")) {
338         return BLOCKDEV_ON_ERROR_IGNORE;
339     } else if (!is_read && !strcmp(buf, "enospc")) {
340         return BLOCKDEV_ON_ERROR_ENOSPC;
341     } else if (!strcmp(buf, "stop")) {
342         return BLOCKDEV_ON_ERROR_STOP;
343     } else if (!strcmp(buf, "report")) {
344         return BLOCKDEV_ON_ERROR_REPORT;
345     } else {
346         error_setg(errp, "'%s' invalid %s error action",
347                    buf, is_read ? "read" : "write");
348         return -1;
349     }
350 }
351 
352 static bool parse_stats_intervals(BlockAcctStats *stats, QList *intervals,
353                                   Error **errp)
354 {
355     const QListEntry *entry;
356     for (entry = qlist_first(intervals); entry; entry = qlist_next(entry)) {
357         switch (qobject_type(entry->value)) {
358 
359         case QTYPE_QSTRING: {
360             unsigned long long length;
361             const char *str = qstring_get_str(qobject_to(QString,
362                                                          entry->value));
363             if (parse_uint_full(str, &length, 10) == 0 &&
364                 length > 0 && length <= UINT_MAX) {
365                 block_acct_add_interval(stats, (unsigned) length);
366             } else {
367                 error_setg(errp, "Invalid interval length: %s", str);
368                 return false;
369             }
370             break;
371         }
372 
373         case QTYPE_QNUM: {
374             int64_t length = qnum_get_int(qobject_to(QNum, entry->value));
375 
376             if (length > 0 && length <= UINT_MAX) {
377                 block_acct_add_interval(stats, (unsigned) length);
378             } else {
379                 error_setg(errp, "Invalid interval length: %" PRId64, length);
380                 return false;
381             }
382             break;
383         }
384 
385         default:
386             error_setg(errp, "The specification of stats-intervals is invalid");
387             return false;
388         }
389     }
390     return true;
391 }
392 
393 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
394 
395 /* All parameters but @opts are optional and may be set to NULL. */
396 static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
397     const char **throttling_group, ThrottleConfig *throttle_cfg,
398     BlockdevDetectZeroesOptions *detect_zeroes, Error **errp)
399 {
400     Error *local_error = NULL;
401     const char *aio;
402 
403     if (bdrv_flags) {
404         if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
405             *bdrv_flags |= BDRV_O_COPY_ON_READ;
406         }
407 
408         if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
409             if (bdrv_parse_aio(aio, bdrv_flags) < 0) {
410                 error_setg(errp, "invalid aio option");
411                 return;
412             }
413         }
414     }
415 
416     /* disk I/O throttling */
417     if (throttling_group) {
418         *throttling_group = qemu_opt_get(opts, "throttling.group");
419     }
420 
421     if (throttle_cfg) {
422         throttle_config_init(throttle_cfg);
423         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
424             qemu_opt_get_number(opts, "throttling.bps-total", 0);
425         throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
426             qemu_opt_get_number(opts, "throttling.bps-read", 0);
427         throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
428             qemu_opt_get_number(opts, "throttling.bps-write", 0);
429         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
430             qemu_opt_get_number(opts, "throttling.iops-total", 0);
431         throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
432             qemu_opt_get_number(opts, "throttling.iops-read", 0);
433         throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
434             qemu_opt_get_number(opts, "throttling.iops-write", 0);
435 
436         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
437             qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
438         throttle_cfg->buckets[THROTTLE_BPS_READ].max  =
439             qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
440         throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
441             qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
442         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
443             qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
444         throttle_cfg->buckets[THROTTLE_OPS_READ].max =
445             qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
446         throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
447             qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
448 
449         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].burst_length =
450             qemu_opt_get_number(opts, "throttling.bps-total-max-length", 1);
451         throttle_cfg->buckets[THROTTLE_BPS_READ].burst_length  =
452             qemu_opt_get_number(opts, "throttling.bps-read-max-length", 1);
453         throttle_cfg->buckets[THROTTLE_BPS_WRITE].burst_length =
454             qemu_opt_get_number(opts, "throttling.bps-write-max-length", 1);
455         throttle_cfg->buckets[THROTTLE_OPS_TOTAL].burst_length =
456             qemu_opt_get_number(opts, "throttling.iops-total-max-length", 1);
457         throttle_cfg->buckets[THROTTLE_OPS_READ].burst_length =
458             qemu_opt_get_number(opts, "throttling.iops-read-max-length", 1);
459         throttle_cfg->buckets[THROTTLE_OPS_WRITE].burst_length =
460             qemu_opt_get_number(opts, "throttling.iops-write-max-length", 1);
461 
462         throttle_cfg->op_size =
463             qemu_opt_get_number(opts, "throttling.iops-size", 0);
464 
465         if (!throttle_is_valid(throttle_cfg, errp)) {
466             return;
467         }
468     }
469 
470     if (detect_zeroes) {
471         *detect_zeroes =
472             qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
473                             qemu_opt_get(opts, "detect-zeroes"),
474                             BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
475                             &local_error);
476         if (local_error) {
477             error_propagate(errp, local_error);
478             return;
479         }
480     }
481 }
482 
483 /* Takes the ownership of bs_opts */
484 static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
485                                    Error **errp)
486 {
487     const char *buf;
488     int bdrv_flags = 0;
489     int on_read_error, on_write_error;
490     bool account_invalid, account_failed;
491     bool writethrough, read_only;
492     BlockBackend *blk;
493     BlockDriverState *bs;
494     ThrottleConfig cfg;
495     int snapshot = 0;
496     Error *error = NULL;
497     QemuOpts *opts;
498     QDict *interval_dict = NULL;
499     QList *interval_list = NULL;
500     const char *id;
501     BlockdevDetectZeroesOptions detect_zeroes =
502         BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
503     const char *throttling_group = NULL;
504 
505     /* Check common options by copying from bs_opts to opts, all other options
506      * stay in bs_opts for processing by bdrv_open(). */
507     id = qdict_get_try_str(bs_opts, "id");
508     opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, errp);
509     if (!opts) {
510         goto err_no_opts;
511     }
512 
513     if (!qemu_opts_absorb_qdict(opts, bs_opts, errp)) {
514         goto early_err;
515     }
516 
517     if (id) {
518         qdict_del(bs_opts, "id");
519     }
520 
521     /* extract parameters */
522     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
523 
524     account_invalid = qemu_opt_get_bool(opts, "stats-account-invalid", true);
525     account_failed = qemu_opt_get_bool(opts, "stats-account-failed", true);
526 
527     writethrough = !qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true);
528 
529     id = qemu_opts_id(opts);
530 
531     qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals.");
532     qdict_array_split(interval_dict, &interval_list);
533 
534     if (qdict_size(interval_dict) != 0) {
535         error_setg(errp, "Invalid option stats-intervals.%s",
536                    qdict_first(interval_dict)->key);
537         goto early_err;
538     }
539 
540     extract_common_blockdev_options(opts, &bdrv_flags, &throttling_group, &cfg,
541                                     &detect_zeroes, &error);
542     if (error) {
543         error_propagate(errp, error);
544         goto early_err;
545     }
546 
547     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
548         if (is_help_option(buf)) {
549             qemu_printf("Supported formats:");
550             bdrv_iterate_format(bdrv_format_print, NULL, false);
551             qemu_printf("\nSupported formats (read-only):");
552             bdrv_iterate_format(bdrv_format_print, NULL, true);
553             qemu_printf("\n");
554             goto early_err;
555         }
556 
557         if (qdict_haskey(bs_opts, "driver")) {
558             error_setg(errp, "Cannot specify both 'driver' and 'format'");
559             goto early_err;
560         }
561         qdict_put_str(bs_opts, "driver", buf);
562     }
563 
564     on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
565     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
566         on_write_error = parse_block_error_action(buf, 0, &error);
567         if (error) {
568             error_propagate(errp, error);
569             goto early_err;
570         }
571     }
572 
573     on_read_error = BLOCKDEV_ON_ERROR_REPORT;
574     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
575         on_read_error = parse_block_error_action(buf, 1, &error);
576         if (error) {
577             error_propagate(errp, error);
578             goto early_err;
579         }
580     }
581 
582     if (snapshot) {
583         bdrv_flags |= BDRV_O_SNAPSHOT;
584     }
585 
586     read_only = qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false);
587 
588     /* init */
589     if ((!file || !*file) && !qdict_size(bs_opts)) {
590         BlockBackendRootState *blk_rs;
591 
592         blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
593         blk_rs = blk_get_root_state(blk);
594         blk_rs->open_flags    = bdrv_flags;
595         blk_rs->read_only     = read_only;
596         blk_rs->detect_zeroes = detect_zeroes;
597 
598         qobject_unref(bs_opts);
599     } else {
600         if (file && !*file) {
601             file = NULL;
602         }
603 
604         /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
605          * with other callers) rather than what we want as the real defaults.
606          * Apply the defaults here instead. */
607         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
608         qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
609         qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY,
610                               read_only ? "on" : "off");
611         qdict_set_default_str(bs_opts, BDRV_OPT_AUTO_READ_ONLY, "on");
612         assert((bdrv_flags & BDRV_O_CACHE_MASK) == 0);
613 
614         if (runstate_check(RUN_STATE_INMIGRATE)) {
615             bdrv_flags |= BDRV_O_INACTIVE;
616         }
617 
618         blk = blk_new_open(file, NULL, bs_opts, bdrv_flags, errp);
619         if (!blk) {
620             goto err_no_bs_opts;
621         }
622         bs = blk_bs(blk);
623 
624         bs->detect_zeroes = detect_zeroes;
625 
626         block_acct_setup(blk_get_stats(blk), account_invalid, account_failed);
627 
628         if (!parse_stats_intervals(blk_get_stats(blk), interval_list, errp)) {
629             blk_unref(blk);
630             blk = NULL;
631             goto err_no_bs_opts;
632         }
633     }
634 
635     /* disk I/O throttling */
636     if (throttle_enabled(&cfg)) {
637         if (!throttling_group) {
638             throttling_group = id;
639         }
640         blk_io_limits_enable(blk, throttling_group);
641         blk_set_io_limits(blk, &cfg);
642     }
643 
644     blk_set_enable_write_cache(blk, !writethrough);
645     blk_set_on_error(blk, on_read_error, on_write_error);
646 
647     if (!monitor_add_blk(blk, id, errp)) {
648         blk_unref(blk);
649         blk = NULL;
650         goto err_no_bs_opts;
651     }
652 
653 err_no_bs_opts:
654     qemu_opts_del(opts);
655     qobject_unref(interval_dict);
656     qobject_unref(interval_list);
657     return blk;
658 
659 early_err:
660     qemu_opts_del(opts);
661     qobject_unref(interval_dict);
662     qobject_unref(interval_list);
663 err_no_opts:
664     qobject_unref(bs_opts);
665     return NULL;
666 }
667 
668 /* Takes the ownership of bs_opts */
669 BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
670 {
671     int bdrv_flags = 0;
672 
673     /* bdrv_open() defaults to the values in bdrv_flags (for compatibility
674      * with other callers) rather than what we want as the real defaults.
675      * Apply the defaults here instead. */
676     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
677     qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
678     qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY, "off");
679 
680     if (runstate_check(RUN_STATE_INMIGRATE)) {
681         bdrv_flags |= BDRV_O_INACTIVE;
682     }
683 
684     return bdrv_open(NULL, NULL, bs_opts, bdrv_flags, errp);
685 }
686 
687 void blockdev_close_all_bdrv_states(void)
688 {
689     BlockDriverState *bs, *next_bs;
690 
691     QTAILQ_FOREACH_SAFE(bs, &monitor_bdrv_states, monitor_list, next_bs) {
692         AioContext *ctx = bdrv_get_aio_context(bs);
693 
694         aio_context_acquire(ctx);
695         bdrv_unref(bs);
696         aio_context_release(ctx);
697     }
698 }
699 
700 /* Iterates over the list of monitor-owned BlockDriverStates */
701 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs)
702 {
703     return bs ? QTAILQ_NEXT(bs, monitor_list)
704               : QTAILQ_FIRST(&monitor_bdrv_states);
705 }
706 
707 static bool qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
708                             Error **errp)
709 {
710     const char *value;
711 
712     value = qemu_opt_get(opts, from);
713     if (value) {
714         if (qemu_opt_find(opts, to)) {
715             error_setg(errp, "'%s' and its alias '%s' can't be used at the "
716                        "same time", to, from);
717             return false;
718         }
719     }
720 
721     /* rename all items in opts */
722     while ((value = qemu_opt_get(opts, from))) {
723         qemu_opt_set(opts, to, value, &error_abort);
724         qemu_opt_unset(opts, from);
725     }
726     return true;
727 }
728 
729 QemuOptsList qemu_legacy_drive_opts = {
730     .name = "drive",
731     .head = QTAILQ_HEAD_INITIALIZER(qemu_legacy_drive_opts.head),
732     .desc = {
733         {
734             .name = "bus",
735             .type = QEMU_OPT_NUMBER,
736             .help = "bus number",
737         },{
738             .name = "unit",
739             .type = QEMU_OPT_NUMBER,
740             .help = "unit number (i.e. lun for scsi)",
741         },{
742             .name = "index",
743             .type = QEMU_OPT_NUMBER,
744             .help = "index number",
745         },{
746             .name = "media",
747             .type = QEMU_OPT_STRING,
748             .help = "media type (disk, cdrom)",
749         },{
750             .name = "if",
751             .type = QEMU_OPT_STRING,
752             .help = "interface (ide, scsi, sd, mtd, floppy, pflash, virtio)",
753         },{
754             .name = "file",
755             .type = QEMU_OPT_STRING,
756             .help = "file name",
757         },
758 
759         /* Options that are passed on, but have special semantics with -drive */
760         {
761             .name = BDRV_OPT_READ_ONLY,
762             .type = QEMU_OPT_BOOL,
763             .help = "open drive file as read-only",
764         },{
765             .name = "rerror",
766             .type = QEMU_OPT_STRING,
767             .help = "read error action",
768         },{
769             .name = "werror",
770             .type = QEMU_OPT_STRING,
771             .help = "write error action",
772         },{
773             .name = "copy-on-read",
774             .type = QEMU_OPT_BOOL,
775             .help = "copy read data from backing file into image file",
776         },
777 
778         { /* end of list */ }
779     },
780 };
781 
782 DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type,
783                      Error **errp)
784 {
785     const char *value;
786     BlockBackend *blk;
787     DriveInfo *dinfo = NULL;
788     QDict *bs_opts;
789     QemuOpts *legacy_opts;
790     DriveMediaType media = MEDIA_DISK;
791     BlockInterfaceType type;
792     int max_devs, bus_id, unit_id, index;
793     const char *werror, *rerror;
794     bool read_only = false;
795     bool copy_on_read;
796     const char *filename;
797     int i;
798 
799     /* Change legacy command line options into QMP ones */
800     static const struct {
801         const char *from;
802         const char *to;
803     } opt_renames[] = {
804         { "iops",           "throttling.iops-total" },
805         { "iops_rd",        "throttling.iops-read" },
806         { "iops_wr",        "throttling.iops-write" },
807 
808         { "bps",            "throttling.bps-total" },
809         { "bps_rd",         "throttling.bps-read" },
810         { "bps_wr",         "throttling.bps-write" },
811 
812         { "iops_max",       "throttling.iops-total-max" },
813         { "iops_rd_max",    "throttling.iops-read-max" },
814         { "iops_wr_max",    "throttling.iops-write-max" },
815 
816         { "bps_max",        "throttling.bps-total-max" },
817         { "bps_rd_max",     "throttling.bps-read-max" },
818         { "bps_wr_max",     "throttling.bps-write-max" },
819 
820         { "iops_size",      "throttling.iops-size" },
821 
822         { "group",          "throttling.group" },
823 
824         { "readonly",       BDRV_OPT_READ_ONLY },
825     };
826 
827     for (i = 0; i < ARRAY_SIZE(opt_renames); i++) {
828         if (!qemu_opt_rename(all_opts, opt_renames[i].from,
829                              opt_renames[i].to, errp)) {
830             return NULL;
831         }
832     }
833 
834     value = qemu_opt_get(all_opts, "cache");
835     if (value) {
836         int flags = 0;
837         bool writethrough;
838 
839         if (bdrv_parse_cache_mode(value, &flags, &writethrough) != 0) {
840             error_setg(errp, "invalid cache option");
841             return NULL;
842         }
843 
844         /* Specific options take precedence */
845         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_WB)) {
846             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_WB,
847                               !writethrough, &error_abort);
848         }
849         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_DIRECT)) {
850             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_DIRECT,
851                               !!(flags & BDRV_O_NOCACHE), &error_abort);
852         }
853         if (!qemu_opt_get(all_opts, BDRV_OPT_CACHE_NO_FLUSH)) {
854             qemu_opt_set_bool(all_opts, BDRV_OPT_CACHE_NO_FLUSH,
855                               !!(flags & BDRV_O_NO_FLUSH), &error_abort);
856         }
857         qemu_opt_unset(all_opts, "cache");
858     }
859 
860     /* Get a QDict for processing the options */
861     bs_opts = qdict_new();
862     qemu_opts_to_qdict(all_opts, bs_opts);
863 
864     legacy_opts = qemu_opts_create(&qemu_legacy_drive_opts, NULL, 0,
865                                    &error_abort);
866     if (!qemu_opts_absorb_qdict(legacy_opts, bs_opts, errp)) {
867         goto fail;
868     }
869 
870     /* Media type */
871     value = qemu_opt_get(legacy_opts, "media");
872     if (value) {
873         if (!strcmp(value, "disk")) {
874             media = MEDIA_DISK;
875         } else if (!strcmp(value, "cdrom")) {
876             media = MEDIA_CDROM;
877             read_only = true;
878         } else {
879             error_setg(errp, "'%s' invalid media", value);
880             goto fail;
881         }
882     }
883 
884     /* copy-on-read is disabled with a warning for read-only devices */
885     read_only |= qemu_opt_get_bool(legacy_opts, BDRV_OPT_READ_ONLY, false);
886     copy_on_read = qemu_opt_get_bool(legacy_opts, "copy-on-read", false);
887 
888     if (read_only && copy_on_read) {
889         warn_report("disabling copy-on-read on read-only drive");
890         copy_on_read = false;
891     }
892 
893     qdict_put_str(bs_opts, BDRV_OPT_READ_ONLY, read_only ? "on" : "off");
894     qdict_put_str(bs_opts, "copy-on-read", copy_on_read ? "on" : "off");
895 
896     /* Controller type */
897     value = qemu_opt_get(legacy_opts, "if");
898     if (value) {
899         for (type = 0;
900              type < IF_COUNT && strcmp(value, if_name[type]);
901              type++) {
902         }
903         if (type == IF_COUNT) {
904             error_setg(errp, "unsupported bus type '%s'", value);
905             goto fail;
906         }
907     } else {
908         type = block_default_type;
909     }
910 
911     /* Device address specified by bus/unit or index.
912      * If none was specified, try to find the first free one. */
913     bus_id  = qemu_opt_get_number(legacy_opts, "bus", 0);
914     unit_id = qemu_opt_get_number(legacy_opts, "unit", -1);
915     index   = qemu_opt_get_number(legacy_opts, "index", -1);
916 
917     max_devs = if_max_devs[type];
918 
919     if (index != -1) {
920         if (bus_id != 0 || unit_id != -1) {
921             error_setg(errp, "index cannot be used with bus and unit");
922             goto fail;
923         }
924         bus_id = drive_index_to_bus_id(type, index);
925         unit_id = drive_index_to_unit_id(type, index);
926     }
927 
928     if (unit_id == -1) {
929        unit_id = 0;
930        while (drive_get(type, bus_id, unit_id) != NULL) {
931            unit_id++;
932            if (max_devs && unit_id >= max_devs) {
933                unit_id -= max_devs;
934                bus_id++;
935            }
936        }
937     }
938 
939     if (max_devs && unit_id >= max_devs) {
940         error_setg(errp, "unit %d too big (max is %d)", unit_id, max_devs - 1);
941         goto fail;
942     }
943 
944     if (drive_get(type, bus_id, unit_id) != NULL) {
945         error_setg(errp, "drive with bus=%d, unit=%d (index=%d) exists",
946                    bus_id, unit_id, index);
947         goto fail;
948     }
949 
950     /* no id supplied -> create one */
951     if (qemu_opts_id(all_opts) == NULL) {
952         char *new_id;
953         const char *mediastr = "";
954         if (type == IF_IDE || type == IF_SCSI) {
955             mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
956         }
957         if (max_devs) {
958             new_id = g_strdup_printf("%s%i%s%i", if_name[type], bus_id,
959                                      mediastr, unit_id);
960         } else {
961             new_id = g_strdup_printf("%s%s%i", if_name[type],
962                                      mediastr, unit_id);
963         }
964         qdict_put_str(bs_opts, "id", new_id);
965         g_free(new_id);
966     }
967 
968     /* Add virtio block device */
969     if (type == IF_VIRTIO) {
970         QemuOpts *devopts;
971         devopts = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
972                                    &error_abort);
973         if (arch_type == QEMU_ARCH_S390X) {
974             qemu_opt_set(devopts, "driver", "virtio-blk-ccw", &error_abort);
975         } else {
976             qemu_opt_set(devopts, "driver", "virtio-blk-pci", &error_abort);
977         }
978         qemu_opt_set(devopts, "drive", qdict_get_str(bs_opts, "id"),
979                      &error_abort);
980     }
981 
982     filename = qemu_opt_get(legacy_opts, "file");
983 
984     /* Check werror/rerror compatibility with if=... */
985     werror = qemu_opt_get(legacy_opts, "werror");
986     if (werror != NULL) {
987         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO &&
988             type != IF_NONE) {
989             error_setg(errp, "werror is not supported by this bus type");
990             goto fail;
991         }
992         qdict_put_str(bs_opts, "werror", werror);
993     }
994 
995     rerror = qemu_opt_get(legacy_opts, "rerror");
996     if (rerror != NULL) {
997         if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI &&
998             type != IF_NONE) {
999             error_setg(errp, "rerror is not supported by this bus type");
1000             goto fail;
1001         }
1002         qdict_put_str(bs_opts, "rerror", rerror);
1003     }
1004 
1005     /* Actual block device init: Functionality shared with blockdev-add */
1006     blk = blockdev_init(filename, bs_opts, errp);
1007     bs_opts = NULL;
1008     if (!blk) {
1009         goto fail;
1010     }
1011 
1012     /* Create legacy DriveInfo */
1013     dinfo = g_malloc0(sizeof(*dinfo));
1014     dinfo->opts = all_opts;
1015 
1016     dinfo->type = type;
1017     dinfo->bus = bus_id;
1018     dinfo->unit = unit_id;
1019 
1020     blk_set_legacy_dinfo(blk, dinfo);
1021 
1022     switch(type) {
1023     case IF_IDE:
1024     case IF_SCSI:
1025     case IF_XEN:
1026     case IF_NONE:
1027         dinfo->media_cd = media == MEDIA_CDROM;
1028         break;
1029     default:
1030         break;
1031     }
1032 
1033 fail:
1034     qemu_opts_del(legacy_opts);
1035     qobject_unref(bs_opts);
1036     return dinfo;
1037 }
1038 
1039 static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
1040 {
1041     BlockDriverState *bs;
1042 
1043     bs = bdrv_lookup_bs(name, name, errp);
1044     if (bs == NULL) {
1045         return NULL;
1046     }
1047 
1048     if (!bdrv_is_root_node(bs)) {
1049         error_setg(errp, "Need a root block node");
1050         return NULL;
1051     }
1052 
1053     if (!bdrv_is_inserted(bs)) {
1054         error_setg(errp, "Device has no medium");
1055         return NULL;
1056     }
1057 
1058     return bs;
1059 }
1060 
1061 static void blockdev_do_action(TransactionAction *action, Error **errp)
1062 {
1063     TransactionActionList list;
1064 
1065     list.value = action;
1066     list.next = NULL;
1067     qmp_transaction(&list, false, NULL, errp);
1068 }
1069 
1070 void qmp_blockdev_snapshot_sync(bool has_device, const char *device,
1071                                 bool has_node_name, const char *node_name,
1072                                 const char *snapshot_file,
1073                                 bool has_snapshot_node_name,
1074                                 const char *snapshot_node_name,
1075                                 bool has_format, const char *format,
1076                                 bool has_mode, NewImageMode mode, Error **errp)
1077 {
1078     BlockdevSnapshotSync snapshot = {
1079         .has_device = has_device,
1080         .device = (char *) device,
1081         .has_node_name = has_node_name,
1082         .node_name = (char *) node_name,
1083         .snapshot_file = (char *) snapshot_file,
1084         .has_snapshot_node_name = has_snapshot_node_name,
1085         .snapshot_node_name = (char *) snapshot_node_name,
1086         .has_format = has_format,
1087         .format = (char *) format,
1088         .has_mode = has_mode,
1089         .mode = mode,
1090     };
1091     TransactionAction action = {
1092         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
1093         .u.blockdev_snapshot_sync.data = &snapshot,
1094     };
1095     blockdev_do_action(&action, errp);
1096 }
1097 
1098 void qmp_blockdev_snapshot(const char *node, const char *overlay,
1099                            Error **errp)
1100 {
1101     BlockdevSnapshot snapshot_data = {
1102         .node = (char *) node,
1103         .overlay = (char *) overlay
1104     };
1105     TransactionAction action = {
1106         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
1107         .u.blockdev_snapshot.data = &snapshot_data,
1108     };
1109     blockdev_do_action(&action, errp);
1110 }
1111 
1112 void qmp_blockdev_snapshot_internal_sync(const char *device,
1113                                          const char *name,
1114                                          Error **errp)
1115 {
1116     BlockdevSnapshotInternal snapshot = {
1117         .device = (char *) device,
1118         .name = (char *) name
1119     };
1120     TransactionAction action = {
1121         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
1122         .u.blockdev_snapshot_internal_sync.data = &snapshot,
1123     };
1124     blockdev_do_action(&action, errp);
1125 }
1126 
1127 SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
1128                                                          bool has_id,
1129                                                          const char *id,
1130                                                          bool has_name,
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     bs = qmp_get_root_bs(device, errp);
1142     if (!bs) {
1143         return NULL;
1144     }
1145     aio_context = bdrv_get_aio_context(bs);
1146     aio_context_acquire(aio_context);
1147 
1148     if (!has_id) {
1149         id = NULL;
1150     }
1151 
1152     if (!has_name) {
1153         name = NULL;
1154     }
1155 
1156     if (!id && !name) {
1157         error_setg(errp, "Name or id must be provided");
1158         goto out_aio_context;
1159     }
1160 
1161     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
1162         goto out_aio_context;
1163     }
1164 
1165     ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
1166     if (local_err) {
1167         error_propagate(errp, local_err);
1168         goto out_aio_context;
1169     }
1170     if (!ret) {
1171         error_setg(errp,
1172                    "Snapshot with id '%s' and name '%s' does not exist on "
1173                    "device '%s'",
1174                    STR_OR_NULL(id), STR_OR_NULL(name), device);
1175         goto out_aio_context;
1176     }
1177 
1178     bdrv_snapshot_delete(bs, id, name, &local_err);
1179     if (local_err) {
1180         error_propagate(errp, local_err);
1181         goto out_aio_context;
1182     }
1183 
1184     aio_context_release(aio_context);
1185 
1186     info = g_new0(SnapshotInfo, 1);
1187     info->id = g_strdup(sn.id_str);
1188     info->name = g_strdup(sn.name);
1189     info->date_nsec = sn.date_nsec;
1190     info->date_sec = sn.date_sec;
1191     info->vm_state_size = sn.vm_state_size;
1192     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
1193     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
1194     if (sn.icount != -1ULL) {
1195         info->icount = sn.icount;
1196         info->has_icount = true;
1197     }
1198 
1199     return info;
1200 
1201 out_aio_context:
1202     aio_context_release(aio_context);
1203     return NULL;
1204 }
1205 
1206 /* New and old BlockDriverState structs for atomic group operations */
1207 
1208 typedef struct BlkActionState BlkActionState;
1209 
1210 /**
1211  * BlkActionOps:
1212  * Table of operations that define an Action.
1213  *
1214  * @instance_size: Size of state struct, in bytes.
1215  * @prepare: Prepare the work, must NOT be NULL.
1216  * @commit: Commit the changes, can be NULL.
1217  * @abort: Abort the changes on fail, can be NULL.
1218  * @clean: Clean up resources after all transaction actions have called
1219  *         commit() or abort(). Can be NULL.
1220  *
1221  * Only prepare() may fail. In a single transaction, only one of commit() or
1222  * abort() will be called. clean() will always be called if it is present.
1223  */
1224 typedef struct BlkActionOps {
1225     size_t instance_size;
1226     void (*prepare)(BlkActionState *common, Error **errp);
1227     void (*commit)(BlkActionState *common);
1228     void (*abort)(BlkActionState *common);
1229     void (*clean)(BlkActionState *common);
1230 } BlkActionOps;
1231 
1232 /**
1233  * BlkActionState:
1234  * Describes one Action's state within a Transaction.
1235  *
1236  * @action: QAPI-defined enum identifying which Action to perform.
1237  * @ops: Table of ActionOps this Action can perform.
1238  * @block_job_txn: Transaction which this action belongs to.
1239  * @entry: List membership for all Actions in this Transaction.
1240  *
1241  * This structure must be arranged as first member in a subclassed type,
1242  * assuming that the compiler will also arrange it to the same offsets as the
1243  * base class.
1244  */
1245 struct BlkActionState {
1246     TransactionAction *action;
1247     const BlkActionOps *ops;
1248     JobTxn *block_job_txn;
1249     TransactionProperties *txn_props;
1250     QTAILQ_ENTRY(BlkActionState) entry;
1251 };
1252 
1253 /* internal snapshot private data */
1254 typedef struct InternalSnapshotState {
1255     BlkActionState common;
1256     BlockDriverState *bs;
1257     QEMUSnapshotInfo sn;
1258     bool created;
1259 } InternalSnapshotState;
1260 
1261 
1262 static int action_check_completion_mode(BlkActionState *s, Error **errp)
1263 {
1264     if (s->txn_props->completion_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
1265         error_setg(errp,
1266                    "Action '%s' does not support Transaction property "
1267                    "completion-mode = %s",
1268                    TransactionActionKind_str(s->action->type),
1269                    ActionCompletionMode_str(s->txn_props->completion_mode));
1270         return -1;
1271     }
1272     return 0;
1273 }
1274 
1275 static void internal_snapshot_prepare(BlkActionState *common,
1276                                       Error **errp)
1277 {
1278     Error *local_err = NULL;
1279     const char *device;
1280     const char *name;
1281     BlockDriverState *bs;
1282     QEMUSnapshotInfo old_sn, *sn;
1283     bool ret;
1284     qemu_timeval tv;
1285     BlockdevSnapshotInternal *internal;
1286     InternalSnapshotState *state;
1287     AioContext *aio_context;
1288     int ret1;
1289 
1290     g_assert(common->action->type ==
1291              TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC);
1292     internal = common->action->u.blockdev_snapshot_internal_sync.data;
1293     state = DO_UPCAST(InternalSnapshotState, common, common);
1294 
1295     /* 1. parse input */
1296     device = internal->device;
1297     name = internal->name;
1298 
1299     /* 2. check for validation */
1300     if (action_check_completion_mode(common, errp) < 0) {
1301         return;
1302     }
1303 
1304     bs = qmp_get_root_bs(device, errp);
1305     if (!bs) {
1306         return;
1307     }
1308 
1309     aio_context = bdrv_get_aio_context(bs);
1310     aio_context_acquire(aio_context);
1311 
1312     state->bs = bs;
1313 
1314     /* Paired with .clean() */
1315     bdrv_drained_begin(bs);
1316 
1317     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
1318         goto out;
1319     }
1320 
1321     if (bdrv_is_read_only(bs)) {
1322         error_setg(errp, "Device '%s' is read only", device);
1323         goto out;
1324     }
1325 
1326     if (!bdrv_can_snapshot(bs)) {
1327         error_setg(errp, "Block format '%s' used by device '%s' "
1328                    "does not support internal snapshots",
1329                    bs->drv->format_name, device);
1330         goto out;
1331     }
1332 
1333     if (!strlen(name)) {
1334         error_setg(errp, "Name is empty");
1335         goto out;
1336     }
1337 
1338     /* check whether a snapshot with name exist */
1339     ret = bdrv_snapshot_find_by_id_and_name(bs, NULL, name, &old_sn,
1340                                             &local_err);
1341     if (local_err) {
1342         error_propagate(errp, local_err);
1343         goto out;
1344     } else if (ret) {
1345         error_setg(errp,
1346                    "Snapshot with name '%s' already exists on device '%s'",
1347                    name, device);
1348         goto out;
1349     }
1350 
1351     /* 3. take the snapshot */
1352     sn = &state->sn;
1353     pstrcpy(sn->name, sizeof(sn->name), name);
1354     qemu_gettimeofday(&tv);
1355     sn->date_sec = tv.tv_sec;
1356     sn->date_nsec = tv.tv_usec * 1000;
1357     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
1358     if (replay_mode != REPLAY_MODE_NONE) {
1359         sn->icount = replay_get_current_icount();
1360     } else {
1361         sn->icount = -1ULL;
1362     }
1363 
1364     ret1 = bdrv_snapshot_create(bs, sn);
1365     if (ret1 < 0) {
1366         error_setg_errno(errp, -ret1,
1367                          "Failed to create snapshot '%s' on device '%s'",
1368                          name, device);
1369         goto out;
1370     }
1371 
1372     /* 4. succeed, mark a snapshot is created */
1373     state->created = true;
1374 
1375 out:
1376     aio_context_release(aio_context);
1377 }
1378 
1379 static void internal_snapshot_abort(BlkActionState *common)
1380 {
1381     InternalSnapshotState *state =
1382                              DO_UPCAST(InternalSnapshotState, common, common);
1383     BlockDriverState *bs = state->bs;
1384     QEMUSnapshotInfo *sn = &state->sn;
1385     AioContext *aio_context;
1386     Error *local_error = NULL;
1387 
1388     if (!state->created) {
1389         return;
1390     }
1391 
1392     aio_context = bdrv_get_aio_context(state->bs);
1393     aio_context_acquire(aio_context);
1394 
1395     if (bdrv_snapshot_delete(bs, sn->id_str, sn->name, &local_error) < 0) {
1396         error_reportf_err(local_error,
1397                           "Failed to delete snapshot with id '%s' and "
1398                           "name '%s' on device '%s' in abort: ",
1399                           sn->id_str, sn->name,
1400                           bdrv_get_device_name(bs));
1401     }
1402 
1403     aio_context_release(aio_context);
1404 }
1405 
1406 static void internal_snapshot_clean(BlkActionState *common)
1407 {
1408     InternalSnapshotState *state = DO_UPCAST(InternalSnapshotState,
1409                                              common, common);
1410     AioContext *aio_context;
1411 
1412     if (!state->bs) {
1413         return;
1414     }
1415 
1416     aio_context = bdrv_get_aio_context(state->bs);
1417     aio_context_acquire(aio_context);
1418 
1419     bdrv_drained_end(state->bs);
1420 
1421     aio_context_release(aio_context);
1422 }
1423 
1424 /* external snapshot private data */
1425 typedef struct ExternalSnapshotState {
1426     BlkActionState common;
1427     BlockDriverState *old_bs;
1428     BlockDriverState *new_bs;
1429     bool overlay_appended;
1430 } ExternalSnapshotState;
1431 
1432 static void external_snapshot_prepare(BlkActionState *common,
1433                                       Error **errp)
1434 {
1435     int flags = 0;
1436     QDict *options = NULL;
1437     Error *local_err = NULL;
1438     /* Device and node name of the image to generate the snapshot from */
1439     const char *device;
1440     const char *node_name;
1441     /* Reference to the new image (for 'blockdev-snapshot') */
1442     const char *snapshot_ref;
1443     /* File name of the new image (for 'blockdev-snapshot-sync') */
1444     const char *new_image_file;
1445     ExternalSnapshotState *state =
1446                              DO_UPCAST(ExternalSnapshotState, common, common);
1447     TransactionAction *action = common->action;
1448     AioContext *aio_context;
1449     uint64_t perm, shared;
1450 
1451     /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
1452      * purpose but a different set of parameters */
1453     switch (action->type) {
1454     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
1455         {
1456             BlockdevSnapshot *s = action->u.blockdev_snapshot.data;
1457             device = s->node;
1458             node_name = s->node;
1459             new_image_file = NULL;
1460             snapshot_ref = s->overlay;
1461         }
1462         break;
1463     case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
1464         {
1465             BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1466             device = s->has_device ? s->device : NULL;
1467             node_name = s->has_node_name ? s->node_name : NULL;
1468             new_image_file = s->snapshot_file;
1469             snapshot_ref = NULL;
1470         }
1471         break;
1472     default:
1473         g_assert_not_reached();
1474     }
1475 
1476     /* start processing */
1477     if (action_check_completion_mode(common, errp) < 0) {
1478         return;
1479     }
1480 
1481     state->old_bs = bdrv_lookup_bs(device, node_name, errp);
1482     if (!state->old_bs) {
1483         return;
1484     }
1485 
1486     aio_context = bdrv_get_aio_context(state->old_bs);
1487     aio_context_acquire(aio_context);
1488 
1489     /* Paired with .clean() */
1490     bdrv_drained_begin(state->old_bs);
1491 
1492     if (!bdrv_is_inserted(state->old_bs)) {
1493         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
1494         goto out;
1495     }
1496 
1497     if (bdrv_op_is_blocked(state->old_bs,
1498                            BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) {
1499         goto out;
1500     }
1501 
1502     if (!bdrv_is_read_only(state->old_bs)) {
1503         if (bdrv_flush(state->old_bs)) {
1504             error_setg(errp, QERR_IO_ERROR);
1505             goto out;
1506         }
1507     }
1508 
1509     if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
1510         BlockdevSnapshotSync *s = action->u.blockdev_snapshot_sync.data;
1511         const char *format = s->has_format ? s->format : "qcow2";
1512         enum NewImageMode mode;
1513         const char *snapshot_node_name =
1514             s->has_snapshot_node_name ? s->snapshot_node_name : NULL;
1515 
1516         if (node_name && !snapshot_node_name) {
1517             error_setg(errp, "New overlay node name missing");
1518             goto out;
1519         }
1520 
1521         if (snapshot_node_name &&
1522             bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
1523             error_setg(errp, "New overlay node name already in use");
1524             goto out;
1525         }
1526 
1527         flags = state->old_bs->open_flags;
1528         flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_COPY_ON_READ);
1529         flags |= BDRV_O_NO_BACKING;
1530 
1531         /* create new image w/backing file */
1532         mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1533         if (mode != NEW_IMAGE_MODE_EXISTING) {
1534             int64_t size = bdrv_getlength(state->old_bs);
1535             if (size < 0) {
1536                 error_setg_errno(errp, -size, "bdrv_getlength failed");
1537                 goto out;
1538             }
1539             bdrv_refresh_filename(state->old_bs);
1540             bdrv_img_create(new_image_file, format,
1541                             state->old_bs->filename,
1542                             state->old_bs->drv->format_name,
1543                             NULL, size, flags, false, &local_err);
1544             if (local_err) {
1545                 error_propagate(errp, local_err);
1546                 goto out;
1547             }
1548         }
1549 
1550         options = qdict_new();
1551         if (snapshot_node_name) {
1552             qdict_put_str(options, "node-name", snapshot_node_name);
1553         }
1554         qdict_put_str(options, "driver", format);
1555     }
1556 
1557     state->new_bs = bdrv_open(new_image_file, snapshot_ref, options, flags,
1558                               errp);
1559     /* We will manually add the backing_hd field to the bs later */
1560     if (!state->new_bs) {
1561         goto out;
1562     }
1563 
1564     /*
1565      * Allow attaching a backing file to an overlay that's already in use only
1566      * if the parents don't assume that they are already seeing a valid image.
1567      * (Specifically, allow it as a mirror target, which is write-only access.)
1568      */
1569     bdrv_get_cumulative_perm(state->new_bs, &perm, &shared);
1570     if (perm & BLK_PERM_CONSISTENT_READ) {
1571         error_setg(errp, "The overlay is already in use");
1572         goto out;
1573     }
1574 
1575     if (state->new_bs->drv->is_filter) {
1576         error_setg(errp, "Filters cannot be used as overlays");
1577         goto out;
1578     }
1579 
1580     if (bdrv_cow_child(state->new_bs)) {
1581         error_setg(errp, "The overlay already has a backing image");
1582         goto out;
1583     }
1584 
1585     if (!state->new_bs->drv->supports_backing) {
1586         error_setg(errp, "The overlay does not support backing images");
1587         goto out;
1588     }
1589 
1590     /* This removes our old bs and adds the new bs. This is an operation that
1591      * can fail, so we need to do it in .prepare; undoing it for abort is
1592      * always possible. */
1593     bdrv_ref(state->new_bs);
1594     bdrv_append(state->new_bs, state->old_bs, &local_err);
1595     if (local_err) {
1596         error_propagate(errp, local_err);
1597         goto out;
1598     }
1599     state->overlay_appended = true;
1600 
1601 out:
1602     aio_context_release(aio_context);
1603 }
1604 
1605 static void external_snapshot_commit(BlkActionState *common)
1606 {
1607     ExternalSnapshotState *state =
1608                              DO_UPCAST(ExternalSnapshotState, common, common);
1609     AioContext *aio_context;
1610 
1611     aio_context = bdrv_get_aio_context(state->old_bs);
1612     aio_context_acquire(aio_context);
1613 
1614     /* We don't need (or want) to use the transactional
1615      * bdrv_reopen_multiple() across all the entries at once, because we
1616      * don't want to abort all of them if one of them fails the reopen */
1617     if (!qatomic_read(&state->old_bs->copy_on_read)) {
1618         bdrv_reopen_set_read_only(state->old_bs, true, NULL);
1619     }
1620 
1621     aio_context_release(aio_context);
1622 }
1623 
1624 static void external_snapshot_abort(BlkActionState *common)
1625 {
1626     ExternalSnapshotState *state =
1627                              DO_UPCAST(ExternalSnapshotState, common, common);
1628     if (state->new_bs) {
1629         if (state->overlay_appended) {
1630             AioContext *aio_context;
1631             AioContext *tmp_context;
1632             int ret;
1633 
1634             aio_context = bdrv_get_aio_context(state->old_bs);
1635             aio_context_acquire(aio_context);
1636 
1637             bdrv_ref(state->old_bs);   /* we can't let bdrv_set_backind_hd()
1638                                           close state->old_bs; we need it */
1639             bdrv_set_backing_hd(state->new_bs, NULL, &error_abort);
1640 
1641             /*
1642              * The call to bdrv_set_backing_hd() above returns state->old_bs to
1643              * the main AioContext. As we're still going to be using it, return
1644              * it to the AioContext it was before.
1645              */
1646             tmp_context = bdrv_get_aio_context(state->old_bs);
1647             if (aio_context != tmp_context) {
1648                 aio_context_release(aio_context);
1649                 aio_context_acquire(tmp_context);
1650 
1651                 ret = bdrv_try_set_aio_context(state->old_bs,
1652                                                aio_context, NULL);
1653                 assert(ret == 0);
1654 
1655                 aio_context_release(tmp_context);
1656                 aio_context_acquire(aio_context);
1657             }
1658 
1659             bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
1660             bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */
1661 
1662             aio_context_release(aio_context);
1663         }
1664     }
1665 }
1666 
1667 static void external_snapshot_clean(BlkActionState *common)
1668 {
1669     ExternalSnapshotState *state =
1670                              DO_UPCAST(ExternalSnapshotState, common, common);
1671     AioContext *aio_context;
1672 
1673     if (!state->old_bs) {
1674         return;
1675     }
1676 
1677     aio_context = bdrv_get_aio_context(state->old_bs);
1678     aio_context_acquire(aio_context);
1679 
1680     bdrv_drained_end(state->old_bs);
1681     bdrv_unref(state->new_bs);
1682 
1683     aio_context_release(aio_context);
1684 }
1685 
1686 typedef struct DriveBackupState {
1687     BlkActionState common;
1688     BlockDriverState *bs;
1689     BlockJob *job;
1690 } DriveBackupState;
1691 
1692 static BlockJob *do_backup_common(BackupCommon *backup,
1693                                   BlockDriverState *bs,
1694                                   BlockDriverState *target_bs,
1695                                   AioContext *aio_context,
1696                                   JobTxn *txn, Error **errp);
1697 
1698 static void drive_backup_prepare(BlkActionState *common, Error **errp)
1699 {
1700     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
1701     DriveBackup *backup;
1702     BlockDriverState *bs;
1703     BlockDriverState *target_bs;
1704     BlockDriverState *source = NULL;
1705     AioContext *aio_context;
1706     AioContext *old_context;
1707     QDict *options;
1708     Error *local_err = NULL;
1709     int flags;
1710     int64_t size;
1711     bool set_backing_hd = false;
1712     int ret;
1713 
1714     assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
1715     backup = common->action->u.drive_backup.data;
1716 
1717     if (!backup->has_mode) {
1718         backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
1719     }
1720 
1721     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1722     if (!bs) {
1723         return;
1724     }
1725 
1726     if (!bs->drv) {
1727         error_setg(errp, "Device has no medium");
1728         return;
1729     }
1730 
1731     aio_context = bdrv_get_aio_context(bs);
1732     aio_context_acquire(aio_context);
1733 
1734     /* Paired with .clean() */
1735     bdrv_drained_begin(bs);
1736 
1737     if (!backup->has_format) {
1738         backup->format = backup->mode == NEW_IMAGE_MODE_EXISTING ?
1739                          NULL : (char *) bs->drv->format_name;
1740     }
1741 
1742     /* Early check to avoid creating target */
1743     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
1744         goto out;
1745     }
1746 
1747     flags = bs->open_flags | BDRV_O_RDWR;
1748 
1749     /*
1750      * See if we have a backing HD we can use to create our new image
1751      * on top of.
1752      */
1753     if (backup->sync == MIRROR_SYNC_MODE_TOP) {
1754         /*
1755          * Backup will not replace the source by the target, so none
1756          * of the filters skipped here will be removed (in contrast to
1757          * mirror).  Therefore, we can skip all of them when looking
1758          * for the first COW relationship.
1759          */
1760         source = bdrv_cow_bs(bdrv_skip_filters(bs));
1761         if (!source) {
1762             backup->sync = MIRROR_SYNC_MODE_FULL;
1763         }
1764     }
1765     if (backup->sync == MIRROR_SYNC_MODE_NONE) {
1766         source = bs;
1767         flags |= BDRV_O_NO_BACKING;
1768         set_backing_hd = true;
1769     }
1770 
1771     size = bdrv_getlength(bs);
1772     if (size < 0) {
1773         error_setg_errno(errp, -size, "bdrv_getlength failed");
1774         goto out;
1775     }
1776 
1777     if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
1778         assert(backup->format);
1779         if (source) {
1780             /* Implicit filters should not appear in the filename */
1781             BlockDriverState *explicit_backing =
1782                 bdrv_skip_implicit_filters(source);
1783 
1784             bdrv_refresh_filename(explicit_backing);
1785             bdrv_img_create(backup->target, backup->format,
1786                             explicit_backing->filename,
1787                             explicit_backing->drv->format_name, NULL,
1788                             size, flags, false, &local_err);
1789         } else {
1790             bdrv_img_create(backup->target, backup->format, NULL, NULL, NULL,
1791                             size, flags, false, &local_err);
1792         }
1793     }
1794 
1795     if (local_err) {
1796         error_propagate(errp, local_err);
1797         goto out;
1798     }
1799 
1800     options = qdict_new();
1801     qdict_put_str(options, "discard", "unmap");
1802     qdict_put_str(options, "detect-zeroes", "unmap");
1803     if (backup->format) {
1804         qdict_put_str(options, "driver", backup->format);
1805     }
1806 
1807     target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
1808     if (!target_bs) {
1809         goto out;
1810     }
1811 
1812     /* Honor bdrv_try_set_aio_context() context acquisition requirements. */
1813     old_context = bdrv_get_aio_context(target_bs);
1814     aio_context_release(aio_context);
1815     aio_context_acquire(old_context);
1816 
1817     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);
1818     if (ret < 0) {
1819         bdrv_unref(target_bs);
1820         aio_context_release(old_context);
1821         return;
1822     }
1823 
1824     aio_context_release(old_context);
1825     aio_context_acquire(aio_context);
1826 
1827     if (set_backing_hd) {
1828         bdrv_set_backing_hd(target_bs, source, &local_err);
1829         if (local_err) {
1830             goto unref;
1831         }
1832     }
1833 
1834     state->bs = bs;
1835 
1836     state->job = do_backup_common(qapi_DriveBackup_base(backup),
1837                                   bs, target_bs, aio_context,
1838                                   common->block_job_txn, errp);
1839 
1840 unref:
1841     bdrv_unref(target_bs);
1842 out:
1843     aio_context_release(aio_context);
1844 }
1845 
1846 static void drive_backup_commit(BlkActionState *common)
1847 {
1848     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
1849     AioContext *aio_context;
1850 
1851     aio_context = bdrv_get_aio_context(state->bs);
1852     aio_context_acquire(aio_context);
1853 
1854     assert(state->job);
1855     job_start(&state->job->job);
1856 
1857     aio_context_release(aio_context);
1858 }
1859 
1860 static void drive_backup_abort(BlkActionState *common)
1861 {
1862     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
1863 
1864     if (state->job) {
1865         AioContext *aio_context;
1866 
1867         aio_context = bdrv_get_aio_context(state->bs);
1868         aio_context_acquire(aio_context);
1869 
1870         job_cancel_sync(&state->job->job);
1871 
1872         aio_context_release(aio_context);
1873     }
1874 }
1875 
1876 static void drive_backup_clean(BlkActionState *common)
1877 {
1878     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
1879     AioContext *aio_context;
1880 
1881     if (!state->bs) {
1882         return;
1883     }
1884 
1885     aio_context = bdrv_get_aio_context(state->bs);
1886     aio_context_acquire(aio_context);
1887 
1888     bdrv_drained_end(state->bs);
1889 
1890     aio_context_release(aio_context);
1891 }
1892 
1893 typedef struct BlockdevBackupState {
1894     BlkActionState common;
1895     BlockDriverState *bs;
1896     BlockJob *job;
1897 } BlockdevBackupState;
1898 
1899 static void blockdev_backup_prepare(BlkActionState *common, Error **errp)
1900 {
1901     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
1902     BlockdevBackup *backup;
1903     BlockDriverState *bs;
1904     BlockDriverState *target_bs;
1905     AioContext *aio_context;
1906     AioContext *old_context;
1907     int ret;
1908 
1909     assert(common->action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
1910     backup = common->action->u.blockdev_backup.data;
1911 
1912     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
1913     if (!bs) {
1914         return;
1915     }
1916 
1917     target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);
1918     if (!target_bs) {
1919         return;
1920     }
1921 
1922     /* Honor bdrv_try_set_aio_context() context acquisition requirements. */
1923     aio_context = bdrv_get_aio_context(bs);
1924     old_context = bdrv_get_aio_context(target_bs);
1925     aio_context_acquire(old_context);
1926 
1927     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);
1928     if (ret < 0) {
1929         aio_context_release(old_context);
1930         return;
1931     }
1932 
1933     aio_context_release(old_context);
1934     aio_context_acquire(aio_context);
1935     state->bs = bs;
1936 
1937     /* Paired with .clean() */
1938     bdrv_drained_begin(state->bs);
1939 
1940     state->job = do_backup_common(qapi_BlockdevBackup_base(backup),
1941                                   bs, target_bs, aio_context,
1942                                   common->block_job_txn, errp);
1943 
1944     aio_context_release(aio_context);
1945 }
1946 
1947 static void blockdev_backup_commit(BlkActionState *common)
1948 {
1949     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
1950     AioContext *aio_context;
1951 
1952     aio_context = bdrv_get_aio_context(state->bs);
1953     aio_context_acquire(aio_context);
1954 
1955     assert(state->job);
1956     job_start(&state->job->job);
1957 
1958     aio_context_release(aio_context);
1959 }
1960 
1961 static void blockdev_backup_abort(BlkActionState *common)
1962 {
1963     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
1964 
1965     if (state->job) {
1966         AioContext *aio_context;
1967 
1968         aio_context = bdrv_get_aio_context(state->bs);
1969         aio_context_acquire(aio_context);
1970 
1971         job_cancel_sync(&state->job->job);
1972 
1973         aio_context_release(aio_context);
1974     }
1975 }
1976 
1977 static void blockdev_backup_clean(BlkActionState *common)
1978 {
1979     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
1980     AioContext *aio_context;
1981 
1982     if (!state->bs) {
1983         return;
1984     }
1985 
1986     aio_context = bdrv_get_aio_context(state->bs);
1987     aio_context_acquire(aio_context);
1988 
1989     bdrv_drained_end(state->bs);
1990 
1991     aio_context_release(aio_context);
1992 }
1993 
1994 typedef struct BlockDirtyBitmapState {
1995     BlkActionState common;
1996     BdrvDirtyBitmap *bitmap;
1997     BlockDriverState *bs;
1998     HBitmap *backup;
1999     bool prepared;
2000     bool was_enabled;
2001 } BlockDirtyBitmapState;
2002 
2003 static void block_dirty_bitmap_add_prepare(BlkActionState *common,
2004                                            Error **errp)
2005 {
2006     Error *local_err = NULL;
2007     BlockDirtyBitmapAdd *action;
2008     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2009                                              common, common);
2010 
2011     if (action_check_completion_mode(common, errp) < 0) {
2012         return;
2013     }
2014 
2015     action = common->action->u.block_dirty_bitmap_add.data;
2016     /* AIO context taken and released within qmp_block_dirty_bitmap_add */
2017     qmp_block_dirty_bitmap_add(action->node, action->name,
2018                                action->has_granularity, action->granularity,
2019                                action->has_persistent, action->persistent,
2020                                action->has_disabled, action->disabled,
2021                                &local_err);
2022 
2023     if (!local_err) {
2024         state->prepared = true;
2025     } else {
2026         error_propagate(errp, local_err);
2027     }
2028 }
2029 
2030 static void block_dirty_bitmap_add_abort(BlkActionState *common)
2031 {
2032     BlockDirtyBitmapAdd *action;
2033     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2034                                              common, common);
2035 
2036     action = common->action->u.block_dirty_bitmap_add.data;
2037     /* Should not be able to fail: IF the bitmap was added via .prepare(),
2038      * then the node reference and bitmap name must have been valid.
2039      */
2040     if (state->prepared) {
2041         qmp_block_dirty_bitmap_remove(action->node, action->name, &error_abort);
2042     }
2043 }
2044 
2045 static void block_dirty_bitmap_clear_prepare(BlkActionState *common,
2046                                              Error **errp)
2047 {
2048     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2049                                              common, common);
2050     BlockDirtyBitmap *action;
2051 
2052     if (action_check_completion_mode(common, errp) < 0) {
2053         return;
2054     }
2055 
2056     action = common->action->u.block_dirty_bitmap_clear.data;
2057     state->bitmap = block_dirty_bitmap_lookup(action->node,
2058                                               action->name,
2059                                               &state->bs,
2060                                               errp);
2061     if (!state->bitmap) {
2062         return;
2063     }
2064 
2065     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_DEFAULT, errp)) {
2066         return;
2067     }
2068 
2069     bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
2070 }
2071 
2072 static void block_dirty_bitmap_restore(BlkActionState *common)
2073 {
2074     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2075                                              common, common);
2076 
2077     if (state->backup) {
2078         bdrv_restore_dirty_bitmap(state->bitmap, state->backup);
2079     }
2080 }
2081 
2082 static void block_dirty_bitmap_free_backup(BlkActionState *common)
2083 {
2084     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2085                                              common, common);
2086 
2087     hbitmap_free(state->backup);
2088 }
2089 
2090 static void block_dirty_bitmap_enable_prepare(BlkActionState *common,
2091                                               Error **errp)
2092 {
2093     BlockDirtyBitmap *action;
2094     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2095                                              common, common);
2096 
2097     if (action_check_completion_mode(common, errp) < 0) {
2098         return;
2099     }
2100 
2101     action = common->action->u.block_dirty_bitmap_enable.data;
2102     state->bitmap = block_dirty_bitmap_lookup(action->node,
2103                                               action->name,
2104                                               NULL,
2105                                               errp);
2106     if (!state->bitmap) {
2107         return;
2108     }
2109 
2110     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2111         return;
2112     }
2113 
2114     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2115     bdrv_enable_dirty_bitmap(state->bitmap);
2116 }
2117 
2118 static void block_dirty_bitmap_enable_abort(BlkActionState *common)
2119 {
2120     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2121                                              common, common);
2122 
2123     if (!state->was_enabled) {
2124         bdrv_disable_dirty_bitmap(state->bitmap);
2125     }
2126 }
2127 
2128 static void block_dirty_bitmap_disable_prepare(BlkActionState *common,
2129                                                Error **errp)
2130 {
2131     BlockDirtyBitmap *action;
2132     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2133                                              common, common);
2134 
2135     if (action_check_completion_mode(common, errp) < 0) {
2136         return;
2137     }
2138 
2139     action = common->action->u.block_dirty_bitmap_disable.data;
2140     state->bitmap = block_dirty_bitmap_lookup(action->node,
2141                                               action->name,
2142                                               NULL,
2143                                               errp);
2144     if (!state->bitmap) {
2145         return;
2146     }
2147 
2148     if (bdrv_dirty_bitmap_check(state->bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2149         return;
2150     }
2151 
2152     state->was_enabled = bdrv_dirty_bitmap_enabled(state->bitmap);
2153     bdrv_disable_dirty_bitmap(state->bitmap);
2154 }
2155 
2156 static void block_dirty_bitmap_disable_abort(BlkActionState *common)
2157 {
2158     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2159                                              common, common);
2160 
2161     if (state->was_enabled) {
2162         bdrv_enable_dirty_bitmap(state->bitmap);
2163     }
2164 }
2165 
2166 static void block_dirty_bitmap_merge_prepare(BlkActionState *common,
2167                                              Error **errp)
2168 {
2169     BlockDirtyBitmapMerge *action;
2170     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2171                                              common, common);
2172 
2173     if (action_check_completion_mode(common, errp) < 0) {
2174         return;
2175     }
2176 
2177     action = common->action->u.block_dirty_bitmap_merge.data;
2178 
2179     state->bitmap = block_dirty_bitmap_merge(action->node, action->target,
2180                                              action->bitmaps, &state->backup,
2181                                              errp);
2182 }
2183 
2184 static void block_dirty_bitmap_remove_prepare(BlkActionState *common,
2185                                               Error **errp)
2186 {
2187     BlockDirtyBitmap *action;
2188     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2189                                              common, common);
2190 
2191     if (action_check_completion_mode(common, errp) < 0) {
2192         return;
2193     }
2194 
2195     action = common->action->u.block_dirty_bitmap_remove.data;
2196 
2197     state->bitmap = block_dirty_bitmap_remove(action->node, action->name,
2198                                               false, &state->bs, errp);
2199     if (state->bitmap) {
2200         bdrv_dirty_bitmap_skip_store(state->bitmap, true);
2201         bdrv_dirty_bitmap_set_busy(state->bitmap, true);
2202     }
2203 }
2204 
2205 static void block_dirty_bitmap_remove_abort(BlkActionState *common)
2206 {
2207     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2208                                              common, common);
2209 
2210     if (state->bitmap) {
2211         bdrv_dirty_bitmap_skip_store(state->bitmap, false);
2212         bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2213     }
2214 }
2215 
2216 static void block_dirty_bitmap_remove_commit(BlkActionState *common)
2217 {
2218     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
2219                                              common, common);
2220 
2221     bdrv_dirty_bitmap_set_busy(state->bitmap, false);
2222     bdrv_release_dirty_bitmap(state->bitmap);
2223 }
2224 
2225 static void abort_prepare(BlkActionState *common, Error **errp)
2226 {
2227     error_setg(errp, "Transaction aborted using Abort action");
2228 }
2229 
2230 static void abort_commit(BlkActionState *common)
2231 {
2232     g_assert_not_reached(); /* this action never succeeds */
2233 }
2234 
2235 static const BlkActionOps actions[] = {
2236     [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT] = {
2237         .instance_size = sizeof(ExternalSnapshotState),
2238         .prepare  = external_snapshot_prepare,
2239         .commit   = external_snapshot_commit,
2240         .abort = external_snapshot_abort,
2241         .clean = external_snapshot_clean,
2242     },
2243     [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC] = {
2244         .instance_size = sizeof(ExternalSnapshotState),
2245         .prepare  = external_snapshot_prepare,
2246         .commit   = external_snapshot_commit,
2247         .abort = external_snapshot_abort,
2248         .clean = external_snapshot_clean,
2249     },
2250     [TRANSACTION_ACTION_KIND_DRIVE_BACKUP] = {
2251         .instance_size = sizeof(DriveBackupState),
2252         .prepare = drive_backup_prepare,
2253         .commit = drive_backup_commit,
2254         .abort = drive_backup_abort,
2255         .clean = drive_backup_clean,
2256     },
2257     [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
2258         .instance_size = sizeof(BlockdevBackupState),
2259         .prepare = blockdev_backup_prepare,
2260         .commit = blockdev_backup_commit,
2261         .abort = blockdev_backup_abort,
2262         .clean = blockdev_backup_clean,
2263     },
2264     [TRANSACTION_ACTION_KIND_ABORT] = {
2265         .instance_size = sizeof(BlkActionState),
2266         .prepare = abort_prepare,
2267         .commit = abort_commit,
2268     },
2269     [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC] = {
2270         .instance_size = sizeof(InternalSnapshotState),
2271         .prepare  = internal_snapshot_prepare,
2272         .abort = internal_snapshot_abort,
2273         .clean = internal_snapshot_clean,
2274     },
2275     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD] = {
2276         .instance_size = sizeof(BlockDirtyBitmapState),
2277         .prepare = block_dirty_bitmap_add_prepare,
2278         .abort = block_dirty_bitmap_add_abort,
2279     },
2280     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR] = {
2281         .instance_size = sizeof(BlockDirtyBitmapState),
2282         .prepare = block_dirty_bitmap_clear_prepare,
2283         .commit = block_dirty_bitmap_free_backup,
2284         .abort = block_dirty_bitmap_restore,
2285     },
2286     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE] = {
2287         .instance_size = sizeof(BlockDirtyBitmapState),
2288         .prepare = block_dirty_bitmap_enable_prepare,
2289         .abort = block_dirty_bitmap_enable_abort,
2290     },
2291     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE] = {
2292         .instance_size = sizeof(BlockDirtyBitmapState),
2293         .prepare = block_dirty_bitmap_disable_prepare,
2294         .abort = block_dirty_bitmap_disable_abort,
2295     },
2296     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_MERGE] = {
2297         .instance_size = sizeof(BlockDirtyBitmapState),
2298         .prepare = block_dirty_bitmap_merge_prepare,
2299         .commit = block_dirty_bitmap_free_backup,
2300         .abort = block_dirty_bitmap_restore,
2301     },
2302     [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_REMOVE] = {
2303         .instance_size = sizeof(BlockDirtyBitmapState),
2304         .prepare = block_dirty_bitmap_remove_prepare,
2305         .commit = block_dirty_bitmap_remove_commit,
2306         .abort = block_dirty_bitmap_remove_abort,
2307     },
2308     /* Where are transactions for MIRROR, COMMIT and STREAM?
2309      * Although these blockjobs use transaction callbacks like the backup job,
2310      * these jobs do not necessarily adhere to transaction semantics.
2311      * These jobs may not fully undo all of their actions on abort, nor do they
2312      * necessarily work in transactions with more than one job in them.
2313      */
2314 };
2315 
2316 /**
2317  * Allocate a TransactionProperties structure if necessary, and fill
2318  * that structure with desired defaults if they are unset.
2319  */
2320 static TransactionProperties *get_transaction_properties(
2321     TransactionProperties *props)
2322 {
2323     if (!props) {
2324         props = g_new0(TransactionProperties, 1);
2325     }
2326 
2327     if (!props->has_completion_mode) {
2328         props->has_completion_mode = true;
2329         props->completion_mode = ACTION_COMPLETION_MODE_INDIVIDUAL;
2330     }
2331 
2332     return props;
2333 }
2334 
2335 /*
2336  * 'Atomic' group operations.  The operations are performed as a set, and if
2337  * any fail then we roll back all operations in the group.
2338  */
2339 void qmp_transaction(TransactionActionList *dev_list,
2340                      bool has_props,
2341                      struct TransactionProperties *props,
2342                      Error **errp)
2343 {
2344     TransactionActionList *dev_entry = dev_list;
2345     JobTxn *block_job_txn = NULL;
2346     BlkActionState *state, *next;
2347     Error *local_err = NULL;
2348 
2349     QTAILQ_HEAD(, BlkActionState) snap_bdrv_states;
2350     QTAILQ_INIT(&snap_bdrv_states);
2351 
2352     /* Does this transaction get canceled as a group on failure?
2353      * If not, we don't really need to make a JobTxn.
2354      */
2355     props = get_transaction_properties(props);
2356     if (props->completion_mode != ACTION_COMPLETION_MODE_INDIVIDUAL) {
2357         block_job_txn = job_txn_new();
2358     }
2359 
2360     /* drain all i/o before any operations */
2361     bdrv_drain_all();
2362 
2363     /* We don't do anything in this loop that commits us to the operations */
2364     while (NULL != dev_entry) {
2365         TransactionAction *dev_info = NULL;
2366         const BlkActionOps *ops;
2367 
2368         dev_info = dev_entry->value;
2369         dev_entry = dev_entry->next;
2370 
2371         assert(dev_info->type < ARRAY_SIZE(actions));
2372 
2373         ops = &actions[dev_info->type];
2374         assert(ops->instance_size > 0);
2375 
2376         state = g_malloc0(ops->instance_size);
2377         state->ops = ops;
2378         state->action = dev_info;
2379         state->block_job_txn = block_job_txn;
2380         state->txn_props = props;
2381         QTAILQ_INSERT_TAIL(&snap_bdrv_states, state, entry);
2382 
2383         state->ops->prepare(state, &local_err);
2384         if (local_err) {
2385             error_propagate(errp, local_err);
2386             goto delete_and_fail;
2387         }
2388     }
2389 
2390     QTAILQ_FOREACH(state, &snap_bdrv_states, entry) {
2391         if (state->ops->commit) {
2392             state->ops->commit(state);
2393         }
2394     }
2395 
2396     /* success */
2397     goto exit;
2398 
2399 delete_and_fail:
2400     /* failure, and it is all-or-none; roll back all operations */
2401     QTAILQ_FOREACH_REVERSE(state, &snap_bdrv_states, entry) {
2402         if (state->ops->abort) {
2403             state->ops->abort(state);
2404         }
2405     }
2406 exit:
2407     QTAILQ_FOREACH_SAFE(state, &snap_bdrv_states, entry, next) {
2408         if (state->ops->clean) {
2409             state->ops->clean(state);
2410         }
2411         g_free(state);
2412     }
2413     if (!has_props) {
2414         qapi_free_TransactionProperties(props);
2415     }
2416     job_txn_unref(block_job_txn);
2417 }
2418 
2419 void qmp_block_passwd(bool has_device, const char *device,
2420                       bool has_node_name, const char *node_name,
2421                       const char *password, Error **errp)
2422 {
2423     error_setg(errp,
2424                "Setting block passwords directly is no longer supported");
2425 }
2426 
2427 BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char *node,
2428                                                               const char *name,
2429                                                               Error **errp)
2430 {
2431     BdrvDirtyBitmap *bitmap;
2432     BlockDriverState *bs;
2433     BlockDirtyBitmapSha256 *ret = NULL;
2434     char *sha256;
2435 
2436     bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
2437     if (!bitmap || !bs) {
2438         return NULL;
2439     }
2440 
2441     sha256 = bdrv_dirty_bitmap_sha256(bitmap, errp);
2442     if (sha256 == NULL) {
2443         return NULL;
2444     }
2445 
2446     ret = g_new(BlockDirtyBitmapSha256, 1);
2447     ret->sha256 = sha256;
2448 
2449     return ret;
2450 }
2451 
2452 void coroutine_fn qmp_block_resize(bool has_device, const char *device,
2453                                    bool has_node_name, const char *node_name,
2454                                    int64_t size, Error **errp)
2455 {
2456     Error *local_err = NULL;
2457     BlockBackend *blk = NULL;
2458     BlockDriverState *bs;
2459     AioContext *old_ctx;
2460 
2461     bs = bdrv_lookup_bs(has_device ? device : NULL,
2462                         has_node_name ? node_name : NULL,
2463                         &local_err);
2464     if (local_err) {
2465         error_propagate(errp, local_err);
2466         return;
2467     }
2468 
2469     if (size < 0) {
2470         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
2471         goto out;
2472     }
2473 
2474     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) {
2475         error_setg(errp, QERR_DEVICE_IN_USE, device);
2476         goto out;
2477     }
2478 
2479     blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL, errp);
2480     if (!blk) {
2481         goto out;
2482     }
2483 
2484     bdrv_drained_begin(bs);
2485     old_ctx = bdrv_co_enter(bs);
2486     blk_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
2487     bdrv_co_leave(bs, old_ctx);
2488     bdrv_drained_end(bs);
2489 
2490 out:
2491     bdrv_co_lock(bs);
2492     blk_unref(blk);
2493     bdrv_co_unlock(bs);
2494 }
2495 
2496 void qmp_block_stream(bool has_job_id, const char *job_id, const char *device,
2497                       bool has_base, const char *base,
2498                       bool has_base_node, const char *base_node,
2499                       bool has_backing_file, const char *backing_file,
2500                       bool has_speed, int64_t speed,
2501                       bool has_on_error, BlockdevOnError on_error,
2502                       bool has_auto_finalize, bool auto_finalize,
2503                       bool has_auto_dismiss, bool auto_dismiss,
2504                       Error **errp)
2505 {
2506     BlockDriverState *bs, *iter;
2507     BlockDriverState *base_bs = NULL;
2508     AioContext *aio_context;
2509     Error *local_err = NULL;
2510     const char *base_name = NULL;
2511     int job_flags = JOB_DEFAULT;
2512 
2513     if (!has_on_error) {
2514         on_error = BLOCKDEV_ON_ERROR_REPORT;
2515     }
2516 
2517     bs = bdrv_lookup_bs(device, device, errp);
2518     if (!bs) {
2519         return;
2520     }
2521 
2522     aio_context = bdrv_get_aio_context(bs);
2523     aio_context_acquire(aio_context);
2524 
2525     if (has_base && has_base_node) {
2526         error_setg(errp, "'base' and 'base-node' cannot be specified "
2527                    "at the same time");
2528         goto out;
2529     }
2530 
2531     if (has_base) {
2532         base_bs = bdrv_find_backing_image(bs, base);
2533         if (base_bs == NULL) {
2534             error_setg(errp, QERR_BASE_NOT_FOUND, base);
2535             goto out;
2536         }
2537         assert(bdrv_get_aio_context(base_bs) == aio_context);
2538         base_name = base;
2539     }
2540 
2541     if (has_base_node) {
2542         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2543         if (!base_bs) {
2544             goto out;
2545         }
2546         if (bs == base_bs || !bdrv_chain_contains(bs, base_bs)) {
2547             error_setg(errp, "Node '%s' is not a backing image of '%s'",
2548                        base_node, device);
2549             goto out;
2550         }
2551         assert(bdrv_get_aio_context(base_bs) == aio_context);
2552         bdrv_refresh_filename(base_bs);
2553         base_name = base_bs->filename;
2554     }
2555 
2556     /* Check for op blockers in the whole chain between bs and base */
2557     for (iter = bs; iter && iter != base_bs;
2558          iter = bdrv_filter_or_cow_bs(iter))
2559     {
2560         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) {
2561             goto out;
2562         }
2563     }
2564 
2565     /* if we are streaming the entire chain, the result will have no backing
2566      * file, and specifying one is therefore an error */
2567     if (base_bs == NULL && has_backing_file) {
2568         error_setg(errp, "backing file specified, but streaming the "
2569                          "entire chain");
2570         goto out;
2571     }
2572 
2573     /* backing_file string overrides base bs filename */
2574     base_name = has_backing_file ? backing_file : base_name;
2575 
2576     if (has_auto_finalize && !auto_finalize) {
2577         job_flags |= JOB_MANUAL_FINALIZE;
2578     }
2579     if (has_auto_dismiss && !auto_dismiss) {
2580         job_flags |= JOB_MANUAL_DISMISS;
2581     }
2582 
2583     stream_start(has_job_id ? job_id : NULL, bs, base_bs, base_name,
2584                  job_flags, has_speed ? speed : 0, on_error, &local_err);
2585     if (local_err) {
2586         error_propagate(errp, local_err);
2587         goto out;
2588     }
2589 
2590     trace_qmp_block_stream(bs);
2591 
2592 out:
2593     aio_context_release(aio_context);
2594 }
2595 
2596 void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
2597                       bool has_base_node, const char *base_node,
2598                       bool has_base, const char *base,
2599                       bool has_top_node, const char *top_node,
2600                       bool has_top, const char *top,
2601                       bool has_backing_file, const char *backing_file,
2602                       bool has_speed, int64_t speed,
2603                       bool has_on_error, BlockdevOnError on_error,
2604                       bool has_filter_node_name, const char *filter_node_name,
2605                       bool has_auto_finalize, bool auto_finalize,
2606                       bool has_auto_dismiss, bool auto_dismiss,
2607                       Error **errp)
2608 {
2609     BlockDriverState *bs;
2610     BlockDriverState *iter;
2611     BlockDriverState *base_bs, *top_bs;
2612     AioContext *aio_context;
2613     Error *local_err = NULL;
2614     int job_flags = JOB_DEFAULT;
2615     uint64_t top_perm, top_shared;
2616 
2617     if (!has_speed) {
2618         speed = 0;
2619     }
2620     if (!has_on_error) {
2621         on_error = BLOCKDEV_ON_ERROR_REPORT;
2622     }
2623     if (!has_filter_node_name) {
2624         filter_node_name = NULL;
2625     }
2626     if (has_auto_finalize && !auto_finalize) {
2627         job_flags |= JOB_MANUAL_FINALIZE;
2628     }
2629     if (has_auto_dismiss && !auto_dismiss) {
2630         job_flags |= JOB_MANUAL_DISMISS;
2631     }
2632 
2633     /* Important Note:
2634      *  libvirt relies on the DeviceNotFound error class in order to probe for
2635      *  live commit feature versions; for this to work, we must make sure to
2636      *  perform the device lookup before any generic errors that may occur in a
2637      *  scenario in which all optional arguments are omitted. */
2638     bs = qmp_get_root_bs(device, &local_err);
2639     if (!bs) {
2640         bs = bdrv_lookup_bs(device, device, NULL);
2641         if (!bs) {
2642             error_free(local_err);
2643             error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
2644                       "Device '%s' not found", device);
2645         } else {
2646             error_propagate(errp, local_err);
2647         }
2648         return;
2649     }
2650 
2651     aio_context = bdrv_get_aio_context(bs);
2652     aio_context_acquire(aio_context);
2653 
2654     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
2655         goto out;
2656     }
2657 
2658     /* default top_bs is the active layer */
2659     top_bs = bs;
2660 
2661     if (has_top_node && has_top) {
2662         error_setg(errp, "'top-node' and 'top' are mutually exclusive");
2663         goto out;
2664     } else if (has_top_node) {
2665         top_bs = bdrv_lookup_bs(NULL, top_node, errp);
2666         if (top_bs == NULL) {
2667             goto out;
2668         }
2669         if (!bdrv_chain_contains(bs, top_bs)) {
2670             error_setg(errp, "'%s' is not in this backing file chain",
2671                        top_node);
2672             goto out;
2673         }
2674     } else if (has_top && top) {
2675         /* This strcmp() is just a shortcut, there is no need to
2676          * refresh @bs's filename.  If it mismatches,
2677          * bdrv_find_backing_image() will do the refresh and may still
2678          * return @bs. */
2679         if (strcmp(bs->filename, top) != 0) {
2680             top_bs = bdrv_find_backing_image(bs, top);
2681         }
2682     }
2683 
2684     if (top_bs == NULL) {
2685         error_setg(errp, "Top image file %s not found", top ? top : "NULL");
2686         goto out;
2687     }
2688 
2689     assert(bdrv_get_aio_context(top_bs) == aio_context);
2690 
2691     if (has_base_node && has_base) {
2692         error_setg(errp, "'base-node' and 'base' are mutually exclusive");
2693         goto out;
2694     } else if (has_base_node) {
2695         base_bs = bdrv_lookup_bs(NULL, base_node, errp);
2696         if (base_bs == NULL) {
2697             goto out;
2698         }
2699         if (!bdrv_chain_contains(top_bs, base_bs)) {
2700             error_setg(errp, "'%s' is not in this backing file chain",
2701                        base_node);
2702             goto out;
2703         }
2704     } else if (has_base && base) {
2705         base_bs = bdrv_find_backing_image(top_bs, base);
2706     } else {
2707         base_bs = bdrv_find_base(top_bs);
2708     }
2709 
2710     if (base_bs == NULL) {
2711         error_setg(errp, QERR_BASE_NOT_FOUND, base ? base : "NULL");
2712         goto out;
2713     }
2714 
2715     assert(bdrv_get_aio_context(base_bs) == aio_context);
2716 
2717     for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs);
2718          iter = bdrv_filter_or_cow_bs(iter))
2719     {
2720         if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2721             goto out;
2722         }
2723     }
2724 
2725     /* Do not allow attempts to commit an image into itself */
2726     if (top_bs == base_bs) {
2727         error_setg(errp, "cannot commit an image into itself");
2728         goto out;
2729     }
2730 
2731     /*
2732      * Active commit is required if and only if someone has taken a
2733      * WRITE permission on the top node.  Historically, we have always
2734      * used active commit for top nodes, so continue that practice
2735      * lest we possibly break clients that rely on this behavior, e.g.
2736      * to later attach this node to a writing parent.
2737      * (Active commit is never really wrong.)
2738      */
2739     bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared);
2740     if (top_perm & BLK_PERM_WRITE ||
2741         bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs))
2742     {
2743         if (has_backing_file) {
2744             if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) {
2745                 error_setg(errp, "'backing-file' specified,"
2746                                  " but 'top' is the active layer");
2747             } else {
2748                 error_setg(errp, "'backing-file' specified, but 'top' has a "
2749                                  "writer on it");
2750             }
2751             goto out;
2752         }
2753         if (!has_job_id) {
2754             /*
2755              * Emulate here what block_job_create() does, because it
2756              * is possible that @bs != @top_bs (the block job should
2757              * be named after @bs, even if @top_bs is the actual
2758              * source)
2759              */
2760             job_id = bdrv_get_device_name(bs);
2761         }
2762         commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error,
2763                             filter_node_name, NULL, NULL, false, &local_err);
2764     } else {
2765         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
2766         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
2767             goto out;
2768         }
2769         commit_start(has_job_id ? job_id : NULL, bs, base_bs, top_bs, job_flags,
2770                      speed, on_error, has_backing_file ? backing_file : NULL,
2771                      filter_node_name, &local_err);
2772     }
2773     if (local_err != NULL) {
2774         error_propagate(errp, local_err);
2775         goto out;
2776     }
2777 
2778 out:
2779     aio_context_release(aio_context);
2780 }
2781 
2782 /* Common QMP interface for drive-backup and blockdev-backup */
2783 static BlockJob *do_backup_common(BackupCommon *backup,
2784                                   BlockDriverState *bs,
2785                                   BlockDriverState *target_bs,
2786                                   AioContext *aio_context,
2787                                   JobTxn *txn, Error **errp)
2788 {
2789     BlockJob *job = NULL;
2790     BdrvDirtyBitmap *bmap = NULL;
2791     int job_flags = JOB_DEFAULT;
2792 
2793     if (!backup->has_speed) {
2794         backup->speed = 0;
2795     }
2796     if (!backup->has_on_source_error) {
2797         backup->on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2798     }
2799     if (!backup->has_on_target_error) {
2800         backup->on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2801     }
2802     if (!backup->has_job_id) {
2803         backup->job_id = NULL;
2804     }
2805     if (!backup->has_auto_finalize) {
2806         backup->auto_finalize = true;
2807     }
2808     if (!backup->has_auto_dismiss) {
2809         backup->auto_dismiss = true;
2810     }
2811     if (!backup->has_compress) {
2812         backup->compress = false;
2813     }
2814 
2815     if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) ||
2816         (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
2817         /* done before desugaring 'incremental' to print the right message */
2818         if (!backup->has_bitmap) {
2819             error_setg(errp, "must provide a valid bitmap name for "
2820                        "'%s' sync mode", MirrorSyncMode_str(backup->sync));
2821             return NULL;
2822         }
2823     }
2824 
2825     if (backup->sync == MIRROR_SYNC_MODE_INCREMENTAL) {
2826         if (backup->has_bitmap_mode &&
2827             backup->bitmap_mode != BITMAP_SYNC_MODE_ON_SUCCESS) {
2828             error_setg(errp, "Bitmap sync mode must be '%s' "
2829                        "when using sync mode '%s'",
2830                        BitmapSyncMode_str(BITMAP_SYNC_MODE_ON_SUCCESS),
2831                        MirrorSyncMode_str(backup->sync));
2832             return NULL;
2833         }
2834         backup->has_bitmap_mode = true;
2835         backup->sync = MIRROR_SYNC_MODE_BITMAP;
2836         backup->bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
2837     }
2838 
2839     if (backup->has_bitmap) {
2840         bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
2841         if (!bmap) {
2842             error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
2843             return NULL;
2844         }
2845         if (!backup->has_bitmap_mode) {
2846             error_setg(errp, "Bitmap sync mode must be given "
2847                        "when providing a bitmap");
2848             return NULL;
2849         }
2850         if (bdrv_dirty_bitmap_check(bmap, BDRV_BITMAP_ALLOW_RO, errp)) {
2851             return NULL;
2852         }
2853 
2854         /* This does not produce a useful bitmap artifact: */
2855         if (backup->sync == MIRROR_SYNC_MODE_NONE) {
2856             error_setg(errp, "sync mode '%s' does not produce meaningful bitmap"
2857                        " outputs", MirrorSyncMode_str(backup->sync));
2858             return NULL;
2859         }
2860 
2861         /* If the bitmap isn't used for input or output, this is useless: */
2862         if (backup->bitmap_mode == BITMAP_SYNC_MODE_NEVER &&
2863             backup->sync != MIRROR_SYNC_MODE_BITMAP) {
2864             error_setg(errp, "Bitmap sync mode '%s' has no meaningful effect"
2865                        " when combined with sync mode '%s'",
2866                        BitmapSyncMode_str(backup->bitmap_mode),
2867                        MirrorSyncMode_str(backup->sync));
2868             return NULL;
2869         }
2870     }
2871 
2872     if (!backup->has_bitmap && backup->has_bitmap_mode) {
2873         error_setg(errp, "Cannot specify bitmap sync mode without a bitmap");
2874         return NULL;
2875     }
2876 
2877     if (!backup->auto_finalize) {
2878         job_flags |= JOB_MANUAL_FINALIZE;
2879     }
2880     if (!backup->auto_dismiss) {
2881         job_flags |= JOB_MANUAL_DISMISS;
2882     }
2883 
2884     job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
2885                             backup->sync, bmap, backup->bitmap_mode,
2886                             backup->compress,
2887                             backup->filter_node_name,
2888                             backup->on_source_error,
2889                             backup->on_target_error,
2890                             job_flags, NULL, NULL, txn, errp);
2891     return job;
2892 }
2893 
2894 void qmp_drive_backup(DriveBackup *backup, Error **errp)
2895 {
2896     TransactionAction action = {
2897         .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
2898         .u.drive_backup.data = backup,
2899     };
2900     blockdev_do_action(&action, errp);
2901 }
2902 
2903 BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
2904                                                  bool flat,
2905                                                  Error **errp)
2906 {
2907     bool return_flat = has_flat && flat;
2908 
2909     return bdrv_named_nodes_list(return_flat, errp);
2910 }
2911 
2912 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
2913 {
2914     return bdrv_get_xdbg_block_graph(errp);
2915 }
2916 
2917 void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)
2918 {
2919     TransactionAction action = {
2920         .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,
2921         .u.blockdev_backup.data = backup,
2922     };
2923     blockdev_do_action(&action, errp);
2924 }
2925 
2926 /* Parameter check and block job starting for drive mirroring.
2927  * Caller should hold @device and @target's aio context (must be the same).
2928  **/
2929 static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
2930                                    BlockDriverState *target,
2931                                    bool has_replaces, const char *replaces,
2932                                    enum MirrorSyncMode sync,
2933                                    BlockMirrorBackingMode backing_mode,
2934                                    bool zero_target,
2935                                    bool has_speed, int64_t speed,
2936                                    bool has_granularity, uint32_t granularity,
2937                                    bool has_buf_size, int64_t buf_size,
2938                                    bool has_on_source_error,
2939                                    BlockdevOnError on_source_error,
2940                                    bool has_on_target_error,
2941                                    BlockdevOnError on_target_error,
2942                                    bool has_unmap, bool unmap,
2943                                    bool has_filter_node_name,
2944                                    const char *filter_node_name,
2945                                    bool has_copy_mode, MirrorCopyMode copy_mode,
2946                                    bool has_auto_finalize, bool auto_finalize,
2947                                    bool has_auto_dismiss, bool auto_dismiss,
2948                                    Error **errp)
2949 {
2950     BlockDriverState *unfiltered_bs;
2951     int job_flags = JOB_DEFAULT;
2952 
2953     if (!has_speed) {
2954         speed = 0;
2955     }
2956     if (!has_on_source_error) {
2957         on_source_error = BLOCKDEV_ON_ERROR_REPORT;
2958     }
2959     if (!has_on_target_error) {
2960         on_target_error = BLOCKDEV_ON_ERROR_REPORT;
2961     }
2962     if (!has_granularity) {
2963         granularity = 0;
2964     }
2965     if (!has_buf_size) {
2966         buf_size = 0;
2967     }
2968     if (!has_unmap) {
2969         unmap = true;
2970     }
2971     if (!has_filter_node_name) {
2972         filter_node_name = NULL;
2973     }
2974     if (!has_copy_mode) {
2975         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
2976     }
2977     if (has_auto_finalize && !auto_finalize) {
2978         job_flags |= JOB_MANUAL_FINALIZE;
2979     }
2980     if (has_auto_dismiss && !auto_dismiss) {
2981         job_flags |= JOB_MANUAL_DISMISS;
2982     }
2983 
2984     if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64)) {
2985         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2986                    "a value in range [512B, 64MB]");
2987         return;
2988     }
2989     if (granularity & (granularity - 1)) {
2990         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "granularity",
2991                    "power of 2");
2992         return;
2993     }
2994 
2995     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
2996         return;
2997     }
2998     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
2999         return;
3000     }
3001 
3002     if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) {
3003         sync = MIRROR_SYNC_MODE_FULL;
3004     }
3005 
3006     if (!has_replaces) {
3007         /* We want to mirror from @bs, but keep implicit filters on top */
3008         unfiltered_bs = bdrv_skip_implicit_filters(bs);
3009         if (unfiltered_bs != bs) {
3010             replaces = unfiltered_bs->node_name;
3011             has_replaces = true;
3012         }
3013     }
3014 
3015     if (has_replaces) {
3016         BlockDriverState *to_replace_bs;
3017         AioContext *replace_aio_context;
3018         int64_t bs_size, replace_size;
3019 
3020         bs_size = bdrv_getlength(bs);
3021         if (bs_size < 0) {
3022             error_setg_errno(errp, -bs_size, "Failed to query device's size");
3023             return;
3024         }
3025 
3026         to_replace_bs = check_to_replace_node(bs, replaces, errp);
3027         if (!to_replace_bs) {
3028             return;
3029         }
3030 
3031         replace_aio_context = bdrv_get_aio_context(to_replace_bs);
3032         aio_context_acquire(replace_aio_context);
3033         replace_size = bdrv_getlength(to_replace_bs);
3034         aio_context_release(replace_aio_context);
3035 
3036         if (replace_size < 0) {
3037             error_setg_errno(errp, -replace_size,
3038                              "Failed to query the replacement node's size");
3039             return;
3040         }
3041         if (bs_size != replace_size) {
3042             error_setg(errp, "cannot replace image with a mirror image of "
3043                              "different size");
3044             return;
3045         }
3046     }
3047 
3048     /* pass the node name to replace to mirror start since it's loose coupling
3049      * and will allow to check whether the node still exist at mirror completion
3050      */
3051     mirror_start(job_id, bs, target,
3052                  has_replaces ? replaces : NULL, job_flags,
3053                  speed, granularity, buf_size, sync, backing_mode, zero_target,
3054                  on_source_error, on_target_error, unmap, filter_node_name,
3055                  copy_mode, errp);
3056 }
3057 
3058 void qmp_drive_mirror(DriveMirror *arg, Error **errp)
3059 {
3060     BlockDriverState *bs;
3061     BlockDriverState *target_backing_bs, *target_bs;
3062     AioContext *aio_context;
3063     AioContext *old_context;
3064     BlockMirrorBackingMode backing_mode;
3065     Error *local_err = NULL;
3066     QDict *options = NULL;
3067     int flags;
3068     int64_t size;
3069     const char *format = arg->format;
3070     bool zero_target;
3071     int ret;
3072 
3073     bs = qmp_get_root_bs(arg->device, errp);
3074     if (!bs) {
3075         return;
3076     }
3077 
3078     /* Early check to avoid creating target */
3079     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR_SOURCE, errp)) {
3080         return;
3081     }
3082 
3083     aio_context = bdrv_get_aio_context(bs);
3084     aio_context_acquire(aio_context);
3085 
3086     if (!arg->has_mode) {
3087         arg->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
3088     }
3089 
3090     if (!arg->has_format) {
3091         format = (arg->mode == NEW_IMAGE_MODE_EXISTING
3092                   ? NULL : bs->drv->format_name);
3093     }
3094 
3095     flags = bs->open_flags | BDRV_O_RDWR;
3096     target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs));
3097     if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) {
3098         arg->sync = MIRROR_SYNC_MODE_FULL;
3099     }
3100     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
3101         target_backing_bs = bs;
3102     }
3103 
3104     size = bdrv_getlength(bs);
3105     if (size < 0) {
3106         error_setg_errno(errp, -size, "bdrv_getlength failed");
3107         goto out;
3108     }
3109 
3110     if (arg->has_replaces) {
3111         if (!arg->has_node_name) {
3112             error_setg(errp, "a node-name must be provided when replacing a"
3113                              " named node of the graph");
3114             goto out;
3115         }
3116     }
3117 
3118     if (arg->mode == NEW_IMAGE_MODE_ABSOLUTE_PATHS) {
3119         backing_mode = MIRROR_SOURCE_BACKING_CHAIN;
3120     } else {
3121         backing_mode = MIRROR_OPEN_BACKING_CHAIN;
3122     }
3123 
3124     /* Don't open backing image in create() */
3125     flags |= BDRV_O_NO_BACKING;
3126 
3127     if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs)
3128         && arg->mode != NEW_IMAGE_MODE_EXISTING)
3129     {
3130         /* create new image w/o backing file */
3131         assert(format);
3132         bdrv_img_create(arg->target, format,
3133                         NULL, NULL, NULL, size, flags, false, &local_err);
3134     } else {
3135         /* Implicit filters should not appear in the filename */
3136         BlockDriverState *explicit_backing =
3137             bdrv_skip_implicit_filters(target_backing_bs);
3138 
3139         switch (arg->mode) {
3140         case NEW_IMAGE_MODE_EXISTING:
3141             break;
3142         case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
3143             /* create new image with backing file */
3144             bdrv_refresh_filename(explicit_backing);
3145             bdrv_img_create(arg->target, format,
3146                             explicit_backing->filename,
3147                             explicit_backing->drv->format_name,
3148                             NULL, size, flags, false, &local_err);
3149             break;
3150         default:
3151             abort();
3152         }
3153     }
3154 
3155     if (local_err) {
3156         error_propagate(errp, local_err);
3157         goto out;
3158     }
3159 
3160     options = qdict_new();
3161     if (arg->has_node_name) {
3162         qdict_put_str(options, "node-name", arg->node_name);
3163     }
3164     if (format) {
3165         qdict_put_str(options, "driver", format);
3166     }
3167 
3168     /* Mirroring takes care of copy-on-write using the source's backing
3169      * file.
3170      */
3171     target_bs = bdrv_open(arg->target, NULL, options, flags, errp);
3172     if (!target_bs) {
3173         goto out;
3174     }
3175 
3176     zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL &&
3177                    (arg->mode == NEW_IMAGE_MODE_EXISTING ||
3178                     !bdrv_has_zero_init(target_bs)));
3179 
3180 
3181     /* Honor bdrv_try_set_aio_context() context acquisition requirements. */
3182     old_context = bdrv_get_aio_context(target_bs);
3183     aio_context_release(aio_context);
3184     aio_context_acquire(old_context);
3185 
3186     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);
3187     if (ret < 0) {
3188         bdrv_unref(target_bs);
3189         aio_context_release(old_context);
3190         return;
3191     }
3192 
3193     aio_context_release(old_context);
3194     aio_context_acquire(aio_context);
3195 
3196     blockdev_mirror_common(arg->has_job_id ? arg->job_id : NULL, bs, target_bs,
3197                            arg->has_replaces, arg->replaces, arg->sync,
3198                            backing_mode, zero_target,
3199                            arg->has_speed, arg->speed,
3200                            arg->has_granularity, arg->granularity,
3201                            arg->has_buf_size, arg->buf_size,
3202                            arg->has_on_source_error, arg->on_source_error,
3203                            arg->has_on_target_error, arg->on_target_error,
3204                            arg->has_unmap, arg->unmap,
3205                            false, NULL,
3206                            arg->has_copy_mode, arg->copy_mode,
3207                            arg->has_auto_finalize, arg->auto_finalize,
3208                            arg->has_auto_dismiss, arg->auto_dismiss,
3209                            errp);
3210     bdrv_unref(target_bs);
3211 out:
3212     aio_context_release(aio_context);
3213 }
3214 
3215 void qmp_blockdev_mirror(bool has_job_id, const char *job_id,
3216                          const char *device, const char *target,
3217                          bool has_replaces, const char *replaces,
3218                          MirrorSyncMode sync,
3219                          bool has_speed, int64_t speed,
3220                          bool has_granularity, uint32_t granularity,
3221                          bool has_buf_size, int64_t buf_size,
3222                          bool has_on_source_error,
3223                          BlockdevOnError on_source_error,
3224                          bool has_on_target_error,
3225                          BlockdevOnError on_target_error,
3226                          bool has_filter_node_name,
3227                          const char *filter_node_name,
3228                          bool has_copy_mode, MirrorCopyMode copy_mode,
3229                          bool has_auto_finalize, bool auto_finalize,
3230                          bool has_auto_dismiss, bool auto_dismiss,
3231                          Error **errp)
3232 {
3233     BlockDriverState *bs;
3234     BlockDriverState *target_bs;
3235     AioContext *aio_context;
3236     AioContext *old_context;
3237     BlockMirrorBackingMode backing_mode = MIRROR_LEAVE_BACKING_CHAIN;
3238     bool zero_target;
3239     int ret;
3240 
3241     bs = qmp_get_root_bs(device, errp);
3242     if (!bs) {
3243         return;
3244     }
3245 
3246     target_bs = bdrv_lookup_bs(target, target, errp);
3247     if (!target_bs) {
3248         return;
3249     }
3250 
3251     zero_target = (sync == MIRROR_SYNC_MODE_FULL);
3252 
3253     /* Honor bdrv_try_set_aio_context() context acquisition requirements. */
3254     old_context = bdrv_get_aio_context(target_bs);
3255     aio_context = bdrv_get_aio_context(bs);
3256     aio_context_acquire(old_context);
3257 
3258     ret = bdrv_try_set_aio_context(target_bs, aio_context, errp);
3259 
3260     aio_context_release(old_context);
3261     aio_context_acquire(aio_context);
3262 
3263     if (ret < 0) {
3264         goto out;
3265     }
3266 
3267     blockdev_mirror_common(has_job_id ? job_id : NULL, bs, target_bs,
3268                            has_replaces, replaces, sync, backing_mode,
3269                            zero_target, has_speed, speed,
3270                            has_granularity, granularity,
3271                            has_buf_size, buf_size,
3272                            has_on_source_error, on_source_error,
3273                            has_on_target_error, on_target_error,
3274                            true, true,
3275                            has_filter_node_name, filter_node_name,
3276                            has_copy_mode, copy_mode,
3277                            has_auto_finalize, auto_finalize,
3278                            has_auto_dismiss, auto_dismiss,
3279                            errp);
3280 out:
3281     aio_context_release(aio_context);
3282 }
3283 
3284 /* Get a block job using its ID and acquire its AioContext */
3285 static BlockJob *find_block_job(const char *id, AioContext **aio_context,
3286                                 Error **errp)
3287 {
3288     BlockJob *job;
3289 
3290     assert(id != NULL);
3291 
3292     *aio_context = NULL;
3293 
3294     job = block_job_get(id);
3295 
3296     if (!job) {
3297         error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
3298                   "Block job '%s' not found", id);
3299         return NULL;
3300     }
3301 
3302     *aio_context = blk_get_aio_context(job->blk);
3303     aio_context_acquire(*aio_context);
3304 
3305     return job;
3306 }
3307 
3308 void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
3309 {
3310     AioContext *aio_context;
3311     BlockJob *job = find_block_job(device, &aio_context, errp);
3312 
3313     if (!job) {
3314         return;
3315     }
3316 
3317     block_job_set_speed(job, speed, errp);
3318     aio_context_release(aio_context);
3319 }
3320 
3321 void qmp_block_job_cancel(const char *device,
3322                           bool has_force, bool force, Error **errp)
3323 {
3324     AioContext *aio_context;
3325     BlockJob *job = find_block_job(device, &aio_context, errp);
3326 
3327     if (!job) {
3328         return;
3329     }
3330 
3331     if (!has_force) {
3332         force = false;
3333     }
3334 
3335     if (job_user_paused(&job->job) && !force) {
3336         error_setg(errp, "The block job for device '%s' is currently paused",
3337                    device);
3338         goto out;
3339     }
3340 
3341     trace_qmp_block_job_cancel(job);
3342     job_user_cancel(&job->job, force, errp);
3343 out:
3344     aio_context_release(aio_context);
3345 }
3346 
3347 void qmp_block_job_pause(const char *device, Error **errp)
3348 {
3349     AioContext *aio_context;
3350     BlockJob *job = find_block_job(device, &aio_context, errp);
3351 
3352     if (!job) {
3353         return;
3354     }
3355 
3356     trace_qmp_block_job_pause(job);
3357     job_user_pause(&job->job, errp);
3358     aio_context_release(aio_context);
3359 }
3360 
3361 void qmp_block_job_resume(const char *device, Error **errp)
3362 {
3363     AioContext *aio_context;
3364     BlockJob *job = find_block_job(device, &aio_context, errp);
3365 
3366     if (!job) {
3367         return;
3368     }
3369 
3370     trace_qmp_block_job_resume(job);
3371     job_user_resume(&job->job, errp);
3372     aio_context_release(aio_context);
3373 }
3374 
3375 void qmp_block_job_complete(const char *device, Error **errp)
3376 {
3377     AioContext *aio_context;
3378     BlockJob *job = find_block_job(device, &aio_context, errp);
3379 
3380     if (!job) {
3381         return;
3382     }
3383 
3384     trace_qmp_block_job_complete(job);
3385     job_complete(&job->job, errp);
3386     aio_context_release(aio_context);
3387 }
3388 
3389 void qmp_block_job_finalize(const char *id, Error **errp)
3390 {
3391     AioContext *aio_context;
3392     BlockJob *job = find_block_job(id, &aio_context, errp);
3393 
3394     if (!job) {
3395         return;
3396     }
3397 
3398     trace_qmp_block_job_finalize(job);
3399     job_ref(&job->job);
3400     job_finalize(&job->job, errp);
3401 
3402     /*
3403      * Job's context might have changed via job_finalize (and job_txn_apply
3404      * automatically acquires the new one), so make sure we release the correct
3405      * one.
3406      */
3407     aio_context = blk_get_aio_context(job->blk);
3408     job_unref(&job->job);
3409     aio_context_release(aio_context);
3410 }
3411 
3412 void qmp_block_job_dismiss(const char *id, Error **errp)
3413 {
3414     AioContext *aio_context;
3415     BlockJob *bjob = find_block_job(id, &aio_context, errp);
3416     Job *job;
3417 
3418     if (!bjob) {
3419         return;
3420     }
3421 
3422     trace_qmp_block_job_dismiss(bjob);
3423     job = &bjob->job;
3424     job_dismiss(&job, errp);
3425     aio_context_release(aio_context);
3426 }
3427 
3428 void qmp_change_backing_file(const char *device,
3429                              const char *image_node_name,
3430                              const char *backing_file,
3431                              Error **errp)
3432 {
3433     BlockDriverState *bs = NULL;
3434     AioContext *aio_context;
3435     BlockDriverState *image_bs = NULL;
3436     Error *local_err = NULL;
3437     bool ro;
3438     int ret;
3439 
3440     bs = qmp_get_root_bs(device, errp);
3441     if (!bs) {
3442         return;
3443     }
3444 
3445     aio_context = bdrv_get_aio_context(bs);
3446     aio_context_acquire(aio_context);
3447 
3448     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
3449     if (local_err) {
3450         error_propagate(errp, local_err);
3451         goto out;
3452     }
3453 
3454     if (!image_bs) {
3455         error_setg(errp, "image file not found");
3456         goto out;
3457     }
3458 
3459     if (bdrv_find_base(image_bs) == image_bs) {
3460         error_setg(errp, "not allowing backing file change on an image "
3461                          "without a backing file");
3462         goto out;
3463     }
3464 
3465     /* even though we are not necessarily operating on bs, we need it to
3466      * determine if block ops are currently prohibited on the chain */
3467     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
3468         goto out;
3469     }
3470 
3471     /* final sanity check */
3472     if (!bdrv_chain_contains(bs, image_bs)) {
3473         error_setg(errp, "'%s' and image file are not in the same chain",
3474                    device);
3475         goto out;
3476     }
3477 
3478     /* if not r/w, reopen to make r/w */
3479     ro = bdrv_is_read_only(image_bs);
3480 
3481     if (ro) {
3482         if (bdrv_reopen_set_read_only(image_bs, false, errp) != 0) {
3483             goto out;
3484         }
3485     }
3486 
3487     ret = bdrv_change_backing_file(image_bs, backing_file,
3488                                    image_bs->drv ? image_bs->drv->format_name : "",
3489                                    false);
3490 
3491     if (ret < 0) {
3492         error_setg_errno(errp, -ret, "Could not change backing file to '%s'",
3493                          backing_file);
3494         /* don't exit here, so we can try to restore open flags if
3495          * appropriate */
3496     }
3497 
3498     if (ro) {
3499         bdrv_reopen_set_read_only(image_bs, true, errp);
3500     }
3501 
3502 out:
3503     aio_context_release(aio_context);
3504 }
3505 
3506 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
3507 {
3508     BlockDriverState *bs;
3509     QObject *obj;
3510     Visitor *v = qobject_output_visitor_new(&obj);
3511     QDict *qdict;
3512 
3513     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3514     visit_complete(v, &obj);
3515     qdict = qobject_to(QDict, obj);
3516 
3517     qdict_flatten(qdict);
3518 
3519     if (!qdict_get_try_str(qdict, "node-name")) {
3520         error_setg(errp, "'node-name' must be specified for the root node");
3521         goto fail;
3522     }
3523 
3524     bs = bds_tree_init(qdict, errp);
3525     if (!bs) {
3526         goto fail;
3527     }
3528 
3529     bdrv_set_monitor_owned(bs);
3530 
3531 fail:
3532     visit_free(v);
3533 }
3534 
3535 void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
3536 {
3537     BlockDriverState *bs;
3538     AioContext *ctx;
3539     QObject *obj;
3540     Visitor *v = qobject_output_visitor_new(&obj);
3541     BlockReopenQueue *queue;
3542     QDict *qdict;
3543 
3544     /* Check for the selected node name */
3545     if (!options->has_node_name) {
3546         error_setg(errp, "Node name not specified");
3547         goto fail;
3548     }
3549 
3550     bs = bdrv_find_node(options->node_name);
3551     if (!bs) {
3552         error_setg(errp, "Cannot find node named '%s'", options->node_name);
3553         goto fail;
3554     }
3555 
3556     /* Put all options in a QDict and flatten it */
3557     visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
3558     visit_complete(v, &obj);
3559     qdict = qobject_to(QDict, obj);
3560 
3561     qdict_flatten(qdict);
3562 
3563     /* Perform the reopen operation */
3564     ctx = bdrv_get_aio_context(bs);
3565     aio_context_acquire(ctx);
3566     bdrv_subtree_drained_begin(bs);
3567     queue = bdrv_reopen_queue(NULL, bs, qdict, false);
3568     bdrv_reopen_multiple(queue, errp);
3569     bdrv_subtree_drained_end(bs);
3570     aio_context_release(ctx);
3571 
3572 fail:
3573     visit_free(v);
3574 }
3575 
3576 void qmp_blockdev_del(const char *node_name, Error **errp)
3577 {
3578     AioContext *aio_context;
3579     BlockDriverState *bs;
3580 
3581     bs = bdrv_find_node(node_name);
3582     if (!bs) {
3583         error_setg(errp, "Cannot find node %s", node_name);
3584         return;
3585     }
3586     if (bdrv_has_blk(bs)) {
3587         error_setg(errp, "Node %s is in use", node_name);
3588         return;
3589     }
3590     aio_context = bdrv_get_aio_context(bs);
3591     aio_context_acquire(aio_context);
3592 
3593     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, errp)) {
3594         goto out;
3595     }
3596 
3597     if (!QTAILQ_IN_USE(bs, monitor_list)) {
3598         error_setg(errp, "Node %s is not owned by the monitor",
3599                    bs->node_name);
3600         goto out;
3601     }
3602 
3603     if (bs->refcnt > 1) {
3604         error_setg(errp, "Block device %s is in use",
3605                    bdrv_get_device_or_node_name(bs));
3606         goto out;
3607     }
3608 
3609     QTAILQ_REMOVE(&monitor_bdrv_states, bs, monitor_list);
3610     bdrv_unref(bs);
3611 
3612 out:
3613     aio_context_release(aio_context);
3614 }
3615 
3616 static BdrvChild *bdrv_find_child(BlockDriverState *parent_bs,
3617                                   const char *child_name)
3618 {
3619     BdrvChild *child;
3620 
3621     QLIST_FOREACH(child, &parent_bs->children, next) {
3622         if (strcmp(child->name, child_name) == 0) {
3623             return child;
3624         }
3625     }
3626 
3627     return NULL;
3628 }
3629 
3630 void qmp_x_blockdev_change(const char *parent, bool has_child,
3631                            const char *child, bool has_node,
3632                            const char *node, Error **errp)
3633 {
3634     BlockDriverState *parent_bs, *new_bs = NULL;
3635     BdrvChild *p_child;
3636 
3637     parent_bs = bdrv_lookup_bs(parent, parent, errp);
3638     if (!parent_bs) {
3639         return;
3640     }
3641 
3642     if (has_child == has_node) {
3643         if (has_child) {
3644             error_setg(errp, "The parameters child and node are in conflict");
3645         } else {
3646             error_setg(errp, "Either child or node must be specified");
3647         }
3648         return;
3649     }
3650 
3651     if (has_child) {
3652         p_child = bdrv_find_child(parent_bs, child);
3653         if (!p_child) {
3654             error_setg(errp, "Node '%s' does not have child '%s'",
3655                        parent, child);
3656             return;
3657         }
3658         bdrv_del_child(parent_bs, p_child, errp);
3659     }
3660 
3661     if (has_node) {
3662         new_bs = bdrv_find_node(node);
3663         if (!new_bs) {
3664             error_setg(errp, "Node '%s' not found", node);
3665             return;
3666         }
3667         bdrv_add_child(parent_bs, new_bs, errp);
3668     }
3669 }
3670 
3671 BlockJobInfoList *qmp_query_block_jobs(Error **errp)
3672 {
3673     BlockJobInfoList *head = NULL, **p_next = &head;
3674     BlockJob *job;
3675 
3676     for (job = block_job_next(NULL); job; job = block_job_next(job)) {
3677         BlockJobInfoList *elem;
3678         AioContext *aio_context;
3679 
3680         if (block_job_is_internal(job)) {
3681             continue;
3682         }
3683         elem = g_new0(BlockJobInfoList, 1);
3684         aio_context = blk_get_aio_context(job->blk);
3685         aio_context_acquire(aio_context);
3686         elem->value = block_job_query(job, errp);
3687         aio_context_release(aio_context);
3688         if (!elem->value) {
3689             g_free(elem);
3690             qapi_free_BlockJobInfoList(head);
3691             return NULL;
3692         }
3693         *p_next = elem;
3694         p_next = &elem->next;
3695     }
3696 
3697     return head;
3698 }
3699 
3700 void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
3701                                  bool has_force, bool force, Error **errp)
3702 {
3703     AioContext *old_context;
3704     AioContext *new_context;
3705     BlockDriverState *bs;
3706 
3707     bs = bdrv_find_node(node_name);
3708     if (!bs) {
3709         error_setg(errp, "Cannot find node %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_set_aio_context(bs, new_context, 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