aboutsummaryrefslogtreecommitdiff
path: root/block/blkdebug.c
blob: 71b4275b9860ff72a3d741bafde30d08b2a3cbcf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
/*
 * Block protocol for I/O error injection
 *
 * Copyright (C) 2016-2017 Red Hat, Inc.
 * Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#include "qemu/config-file.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "sysemu/qtest.h"

typedef struct BDRVBlkdebugState {
    int state;
    int new_state;
    uint64_t align;
    uint64_t max_transfer;
    uint64_t opt_write_zero;
    uint64_t max_write_zero;
    uint64_t opt_discard;
    uint64_t max_discard;

    /* For blkdebug_refresh_filename() */
    char *config_file;

    QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
    QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
    QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
} BDRVBlkdebugState;

typedef struct BlkdebugAIOCB {
    BlockAIOCB common;
    int ret;
} BlkdebugAIOCB;

typedef struct BlkdebugSuspendedReq {
    Coroutine *co;
    char *tag;
    QLIST_ENTRY(BlkdebugSuspendedReq) next;
} BlkdebugSuspendedReq;

enum {
    ACTION_INJECT_ERROR,
    ACTION_SET_STATE,
    ACTION_SUSPEND,
};

typedef struct BlkdebugRule {
    BlkdebugEvent event;
    int action;
    int state;
    union {
        struct {
            int error;
            int immediately;
            int once;
            int64_t offset;
        } inject;
        struct {
            int new_state;
        } set_state;
        struct {
            char *tag;
        } suspend;
    } options;
    QLIST_ENTRY(BlkdebugRule) next;
    QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
} BlkdebugRule;

static QemuOptsList inject_error_opts = {
    .name = "inject-error",
    .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
    .desc = {
        {
            .name = "event",
            .type = QEMU_OPT_STRING,
        },
        {
            .name = "state",
            .type = QEMU_OPT_NUMBER,
        },
        {
            .name = "errno",
            .type = QEMU_OPT_NUMBER,
        },
        {
            .name = "sector",
            .type = QEMU_OPT_NUMBER,
        },
        {
            .name = "once",
            .type = QEMU_OPT_BOOL,
        },
        {
            .name = "immediately",
            .type = QEMU_OPT_BOOL,
        },
        { /* end of list */ }
    },
};

static QemuOptsList set_state_opts = {
    .name = "set-state",
    .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
    .desc = {
        {
            .name = "event",
            .type = QEMU_OPT_STRING,
        },
        {
            .name = "state",
            .type = QEMU_OPT_NUMBER,
        },
        {
            .name = "new_state",
            .type = QEMU_OPT_NUMBER,
        },
        { /* end of list */ }
    },
};

static QemuOptsList *config_groups[] = {
    &inject_error_opts,
    &set_state_opts,
    NULL
};

struct add_rule_data {
    BDRVBlkdebugState *s;
    int action;
};

static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
{
    struct add_rule_data *d = opaque;
    BDRVBlkdebugState *s = d->s;
    const char* event_name;
    int event;
    struct BlkdebugRule *rule;
    int64_t sector;

    /* Find the right event for the rule */
    event_name = qemu_opt_get(opts, "event");
    if (!event_name) {
        error_setg(errp, "Missing event name for rule");
        return -1;
    }
    event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
    if (event < 0) {
        return -1;
    }

    /* Set attributes common for all actions */
    rule = g_malloc0(sizeof(*rule));
    *rule = (struct BlkdebugRule) {
        .event  = event,
        .action = d->action,
        .state  = qemu_opt_get_number(opts, "state", 0),
    };

    /* Parse action-specific options */
    switch (d->action) {
    case ACTION_INJECT_ERROR:
        rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
        rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
        rule->options.inject.immediately =
            qemu_opt_get_bool(opts, "immediately", 0);
        sector = qemu_opt_get_number(opts, "sector", -1);
        rule->options.inject.offset =
            sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
        break;

    case ACTION_SET_STATE:
        rule->options.set_state.new_state =
            qemu_opt_get_number(opts, "new_state", 0);
        break;

    case ACTION_SUSPEND:
        rule->options.suspend.tag =
            g_strdup(qemu_opt_get(opts, "tag"));
        break;
    };

    /* Add the rule */
    QLIST_INSERT_HEAD(&s->rules[event], rule, next);

    return 0;
}

static void remove_rule(BlkdebugRule *rule)
{
    switch (rule->action) {
    case ACTION_INJECT_ERROR:
    case ACTION_SET_STATE:
        break;
    case ACTION_SUSPEND:
        g_free(rule->options.suspend.tag);
        break;
    }

    QLIST_REMOVE(rule, next);
    g_free(rule);
}

static int read_config(BDRVBlkdebugState *s, const char *filename,
                       QDict *options, Error **errp)
{
    FILE *f = NULL;
    int ret;
    struct add_rule_data d;
    Error *local_err = NULL;

    if (filename) {
        f = fopen(filename, "r");
        if (f == NULL) {
            error_setg_errno(errp, errno, "Could not read blkdebug config file");
            return -errno;
        }

        ret = qemu_config_parse(f, config_groups, filename);
        if (ret < 0) {
            error_setg(errp, "Could not parse blkdebug config file");
            goto fail;
        }
    }

    qemu_config_parse_qdict(options, config_groups, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        ret = -EINVAL;
        goto fail;
    }

    d.s = s;
    d.action = ACTION_INJECT_ERROR;
    qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        ret = -EINVAL;
        goto fail;
    }

    d.action = ACTION_SET_STATE;
    qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        ret = -EINVAL;
        goto fail;
    }

    ret = 0;
fail:
    qemu_opts_reset(&inject_error_opts);
    qemu_opts_reset(&set_state_opts);
    if (f) {
        fclose(f);
    }
    return ret;
}

/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
static void blkdebug_parse_filename(const char *filename, QDict *options,
                                    Error **errp)
{
    const char *c;

    /* Parse the blkdebug: prefix */
    if (!strstart(filename, "blkdebug:", &filename)) {
        /* There was no prefix; therefore, all options have to be already
           present in the QDict (except for the filename) */
        qdict_put_str(options, "x-image", filename);
        return;
    }

    /* Parse config file path */
    c = strchr(filename, ':');
    if (c == NULL) {
        error_setg(errp, "blkdebug requires both config file and image path");
        return;
    }

    if (c != filename) {
        QString *config_path;
        config_path = qstring_from_substr(filename, 0, c - filename);
        qdict_put(options, "config", config_path);
    }

    /* TODO Allow multi-level nesting and set file.filename here */
    filename = c + 1;
    qdict_put_str(options, "x-image", filename);
}

static QemuOptsList runtime_opts = {
    .name = "blkdebug",
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
    .desc = {
        {
            .name = "config",
            .type = QEMU_OPT_STRING,
            .help = "Path to the configuration file",
        },
        {
            .name = "x-image",
            .type = QEMU_OPT_STRING,
            .help = "[internal use only, will be removed]",
        },
        {
            .name = "align",
            .type = QEMU_OPT_SIZE,
            .help = "Required alignment in bytes",
        },
        {
            .name = "max-transfer",
            .type = QEMU_OPT_SIZE,
            .help = "Maximum transfer size in bytes",
        },
        {
            .name = "opt-write-zero",
            .type = QEMU_OPT_SIZE,
            .help = "Optimum write zero alignment in bytes",
        },
        {
            .name = "max-write-zero",
            .type = QEMU_OPT_SIZE,
            .help = "Maximum write zero size in bytes",
        },
        {
            .name = "opt-discard",
            .type = QEMU_OPT_SIZE,
            .help = "Optimum discard alignment in bytes",
        },
        {
            .name = "max-discard",
            .type = QEMU_OPT_SIZE,
            .help = "Maximum discard size in bytes",
        },
        { /* end of list */ }
    },
};

static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
                         Error **errp)
{
    BDRVBlkdebugState *s = bs->opaque;
    QemuOpts *opts;
    Error *local_err = NULL;
    int ret;
    uint64_t align;

    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
    qemu_opts_absorb_qdict(opts, options, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        ret = -EINVAL;
        goto out;
    }

    /* Read rules from config file or command line options */
    s->config_file = g_strdup(qemu_opt_get(opts, "config"));
    ret = read_config(s, s->config_file, options, errp);
    if (ret) {
        goto out;
    }

    /* Set initial state */
    s->state = 1;

    /* Open the image file */
    bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
                               bs, &child_file, false, &local_err);
    if (local_err) {
        ret = -EINVAL;
        error_propagate(errp, local_err);
        goto out;
    }

    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
        (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
        ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
            bs->file->bs->supported_zero_flags);
    ret = -EINVAL;

    /* Set alignment overrides */
    s->align = qemu_opt_get_size(opts, "align", 0);
    if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
        error_setg(errp, "Cannot meet constraints with align %" PRIu64,
                   s->align);
        goto out;
    }
    align = MAX(s->align, bs->file->bs->bl.request_alignment);

    s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
    if (s->max_transfer &&
        (s->max_transfer >= INT_MAX ||
         !QEMU_IS_ALIGNED(s->max_transfer, align))) {
        error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
                   s->max_transfer);
        goto out;
    }

    s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
    if (s->opt_write_zero &&
        (s->opt_write_zero >= INT_MAX ||
         !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
        error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
                   s->opt_write_zero);
        goto out;
    }

    s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
    if (s->max_write_zero &&
        (s->max_write_zero >= INT_MAX ||
         !QEMU_IS_ALIGNED(s->max_write_zero,
                          MAX(s->opt_write_zero, align)))) {
        error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
                   s->max_write_zero);
        goto out;
    }

    s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
    if (s->opt_discard &&
        (s->opt_discard >= INT_MAX ||
         !QEMU_IS_ALIGNED(s->opt_discard, align))) {
        error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
                   s->opt_discard);
        goto out;
    }

    s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
    if (s->max_discard &&
        (s->max_discard >= INT_MAX ||
         !QEMU_IS_ALIGNED(s->max_discard,
                          MAX(s->opt_discard, align)))) {
        error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
                   s->max_discard);
        goto out;
    }

    ret = 0;
out:
    if (ret < 0) {
        g_free(s->config_file);
    }
    qemu_opts_del(opts);
    return ret;
}

static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugRule *rule = NULL;
    int error;
    bool immediately;

    QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
        uint64_t inject_offset = rule->options.inject.offset;

        if (inject_offset == -1 ||
            (bytes && inject_offset >= offset &&
             inject_offset < offset + bytes))
        {
            break;
        }
    }

    if (!rule || !rule->options.inject.error) {
        return 0;
    }

    immediately = rule->options.inject.immediately;
    error = rule->options.inject.error;

    if (rule->options.inject.once) {
        QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
        remove_rule(rule);
    }

    if (!immediately) {
        aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
        qemu_coroutine_yield();
    }

    return -error;
}

static int coroutine_fn
blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                   QEMUIOVector *qiov, int flags)
{
    int err;

    /* Sanity check block layer guarantees */
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
    if (bs->bl.max_transfer) {
        assert(bytes <= bs->bl.max_transfer);
    }

    err = rule_check(bs, offset, bytes);
    if (err) {
        return err;
    }

    return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
}

static int coroutine_fn
blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                    QEMUIOVector *qiov, int flags)
{
    int err;

    /* Sanity check block layer guarantees */
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
    if (bs->bl.max_transfer) {
        assert(bytes <= bs->bl.max_transfer);
    }

    err = rule_check(bs, offset, bytes);
    if (err) {
        return err;
    }

    return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
}

static int blkdebug_co_flush(BlockDriverState *bs)
{
    int err = rule_check(bs, 0, 0);

    if (err) {
        return err;
    }

    return bdrv_co_flush(bs->file->bs);
}

static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
                                                  int64_t offset, int bytes,
                                                  BdrvRequestFlags flags)
{
    uint32_t align = MAX(bs->bl.request_alignment,
                         bs->bl.pwrite_zeroes_alignment);
    int err;

    /* Only pass through requests that are larger than requested
     * preferred alignment (so that we test the fallback to writes on
     * unaligned portions), and check that the block layer never hands
     * us anything unaligned that crosses an alignment boundary.  */
    if (bytes < align) {
        assert(QEMU_IS_ALIGNED(offset, align) ||
               QEMU_IS_ALIGNED(offset + bytes, align) ||
               DIV_ROUND_UP(offset, align) ==
               DIV_ROUND_UP(offset + bytes, align));
        return -ENOTSUP;
    }
    assert(QEMU_IS_ALIGNED(offset, align));
    assert(QEMU_IS_ALIGNED(bytes, align));
    if (bs->bl.max_pwrite_zeroes) {
        assert(bytes <= bs->bl.max_pwrite_zeroes);
    }

    err = rule_check(bs, offset, bytes);
    if (err) {
        return err;
    }

    return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
}

static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
                                             int64_t offset, int bytes)
{
    uint32_t align = bs->bl.pdiscard_alignment;
    int err;

    /* Only pass through requests that are larger than requested
     * minimum alignment, and ensure that unaligned requests do not
     * cross optimum discard boundaries. */
    if (bytes < bs->bl.request_alignment) {
        assert(QEMU_IS_ALIGNED(offset, align) ||
               QEMU_IS_ALIGNED(offset + bytes, align) ||
               DIV_ROUND_UP(offset, align) ==
               DIV_ROUND_UP(offset + bytes, align));
        return -ENOTSUP;
    }
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
    if (align && bytes >= align) {
        assert(QEMU_IS_ALIGNED(offset, align));
        assert(QEMU_IS_ALIGNED(bytes, align));
    }
    if (bs->bl.max_pdiscard) {
        assert(bytes <= bs->bl.max_pdiscard);
    }

    err = rule_check(bs, offset, bytes);
    if (err) {
        return err;
    }

    return bdrv_co_pdiscard(bs->file, offset, bytes);
}

static int coroutine_fn blkdebug_co_block_status(BlockDriverState *bs,
                                                 bool want_zero,
                                                 int64_t offset,
                                                 int64_t bytes,
                                                 int64_t *pnum,
                                                 int64_t *map,
                                                 BlockDriverState **file)
{
    assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
    return bdrv_co_block_status_from_file(bs, want_zero, offset, bytes,
                                          pnum, map, file);
}

static void blkdebug_close(BlockDriverState *bs)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugRule *rule, *next;
    int i;

    for (i = 0; i < BLKDBG__MAX; i++) {
        QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
            remove_rule(rule);
        }
    }

    g_free(s->config_file);
}

static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugSuspendedReq r;

    r = (BlkdebugSuspendedReq) {
        .co         = qemu_coroutine_self(),
        .tag        = g_strdup(rule->options.suspend.tag),
    };

    remove_rule(rule);
    QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);

    if (!qtest_enabled()) {
        printf("blkdebug: Suspended request '%s'\n", r.tag);
    }
    qemu_coroutine_yield();
    if (!qtest_enabled()) {
        printf("blkdebug: Resuming request '%s'\n", r.tag);
    }

    QLIST_REMOVE(&r, next);
    g_free(r.tag);
}

static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
    bool injected)
{
    BDRVBlkdebugState *s = bs->opaque;

    /* Only process rules for the current state */
    if (rule->state && rule->state != s->state) {
        return injected;
    }

    /* Take the action */
    switch (rule->action) {
    case ACTION_INJECT_ERROR:
        if (!injected) {
            QSIMPLEQ_INIT(&s->active_rules);
            injected = true;
        }
        QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
        break;

    case ACTION_SET_STATE:
        s->new_state = rule->options.set_state.new_state;
        break;

    case ACTION_SUSPEND:
        suspend_request(bs, rule);
        break;
    }
    return injected;
}

static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
{
    BDRVBlkdebugState *s = bs->opaque;
    struct BlkdebugRule *rule, *next;
    bool injected;

    assert((int)event >= 0 && event < BLKDBG__MAX);

    injected = false;
    s->new_state = s->state;
    QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
        injected = process_rule(bs, rule, injected);
    }
    s->state = s->new_state;
}

static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
                                     const char *tag)
{
    BDRVBlkdebugState *s = bs->opaque;
    struct BlkdebugRule *rule;
    int blkdebug_event;

    blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
    if (blkdebug_event < 0) {
        return -ENOENT;
    }

    rule = g_malloc(sizeof(*rule));
    *rule = (struct BlkdebugRule) {
        .event  = blkdebug_event,
        .action = ACTION_SUSPEND,
        .state  = 0,
        .options.suspend.tag = g_strdup(tag),
    };

    QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);

    return 0;
}

static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugSuspendedReq *r, *next;

    QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
        if (!strcmp(r->tag, tag)) {
            qemu_coroutine_enter(r->co);
            return 0;
        }
    }
    return -ENOENT;
}

static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
                                            const char *tag)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugSuspendedReq *r, *r_next;
    BlkdebugRule *rule, *next;
    int i, ret = -ENOENT;

    for (i = 0; i < BLKDBG__MAX; i++) {
        QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
            if (rule->action == ACTION_SUSPEND &&
                !strcmp(rule->options.suspend.tag, tag)) {
                remove_rule(rule);
                ret = 0;
            }
        }
    }
    QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
        if (!strcmp(r->tag, tag)) {
            qemu_coroutine_enter(r->co);
            ret = 0;
        }
    }
    return ret;
}

static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
{
    BDRVBlkdebugState *s = bs->opaque;
    BlkdebugSuspendedReq *r;

    QLIST_FOREACH(r, &s->suspended_reqs, next) {
        if (!strcmp(r->tag, tag)) {
            return true;
        }
    }
    return false;
}

static int64_t blkdebug_getlength(BlockDriverState *bs)
{
    return bdrv_getlength(bs->file->bs);
}

static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
{
    BDRVBlkdebugState *s = bs->opaque;
    QDict *opts;
    const QDictEntry *e;
    bool force_json = false;

    for (e = qdict_first(options); e; e = qdict_next(options, e)) {
        if (strcmp(qdict_entry_key(e), "config") &&
            strcmp(qdict_entry_key(e), "x-image"))
        {
            force_json = true;
            break;
        }
    }

    if (force_json && !bs->file->bs->full_open_options) {
        /* The config file cannot be recreated, so creating a plain filename
         * is impossible */
        return;
    }

    if (!force_json && bs->file->bs->exact_filename[0]) {
        int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
                           "blkdebug:%s:%s", s->config_file ?: "",
                           bs->file->bs->exact_filename);
        if (ret >= sizeof(bs->exact_filename)) {
            /* An overflow makes the filename unusable, so do not report any */
            bs->exact_filename[0] = 0;
        }
    }

    opts = qdict_new();
    qdict_put_str(opts, "driver", "blkdebug");

    qdict_put(opts, "image", qobject_ref(bs->file->bs->full_open_options));

    for (e = qdict_first(options); e; e = qdict_next(options, e)) {
        if (strcmp(qdict_entry_key(e), "x-image")) {
            qdict_put_obj(opts, qdict_entry_key(e),
                          qobject_ref(qdict_entry_value(e)));
        }
    }

    bs->full_open_options = opts;
}

static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
{
    BDRVBlkdebugState *s = bs->opaque;

    if (s->align) {
        bs->bl.request_alignment = s->align;
    }
    if (s->max_transfer) {
        bs->bl.max_transfer = s->max_transfer;
    }
    if (s->opt_write_zero) {
        bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
    }
    if (s->max_write_zero) {
        bs->bl.max_pwrite_zeroes = s->max_write_zero;
    }
    if (s->opt_discard) {
        bs->bl.pdiscard_alignment = s->opt_discard;
    }
    if (s->max_discard) {
        bs->bl.max_pdiscard = s->max_discard;
    }
}

static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
                                   BlockReopenQueue *queue, Error **errp)
{
    return 0;
}

static const char *const blkdebug_strong_runtime_opts[] = {
    "config",
    "inject-error.",
    "set-state.",
    "align",
    "max-transfer",
    "opt-write-zero",
    "max-write-zero",
    "opt-discard",
    "max-discard",

    NULL
};

static BlockDriver bdrv_blkdebug = {
    .format_name            = "blkdebug",
    .protocol_name          = "blkdebug",
    .instance_size          = sizeof(BDRVBlkdebugState),
    .is_filter              = true,

    .bdrv_parse_filename    = blkdebug_parse_filename,
    .bdrv_file_open         = blkdebug_open,
    .bdrv_close             = blkdebug_close,
    .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
    .bdrv_child_perm        = bdrv_filter_default_perms,

    .bdrv_getlength         = blkdebug_getlength,
    .bdrv_refresh_filename  = blkdebug_refresh_filename,
    .bdrv_refresh_limits    = blkdebug_refresh_limits,

    .bdrv_co_preadv         = blkdebug_co_preadv,
    .bdrv_co_pwritev        = blkdebug_co_pwritev,
    .bdrv_co_flush_to_disk  = blkdebug_co_flush,
    .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
    .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
    .bdrv_co_block_status   = blkdebug_co_block_status,

    .bdrv_debug_event           = blkdebug_debug_event,
    .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
    .bdrv_debug_remove_breakpoint
                                = blkdebug_debug_remove_breakpoint,
    .bdrv_debug_resume          = blkdebug_debug_resume,
    .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,

    .strong_runtime_opts        = blkdebug_strong_runtime_opts,
};

static void bdrv_blkdebug_init(void)
{
    bdrv_register(&bdrv_blkdebug);
}

block_init(bdrv_blkdebug_init);