qemu

1
/*
2
 * Block protocol for I/O error injection
3
 *
4
 * Copyright (C) 2016-2017 Red Hat, Inc.
5
 * Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
6
 *
7
 * Permission is hereby granted, free of charge, to any person obtaining a copy
8
 * of this software and associated documentation files (the "Software"), to deal
9
 * in the Software without restriction, including without limitation the rights
10
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11
 * copies of the Software, and to permit persons to whom the Software is
12
 * furnished to do so, subject to the following conditions:
13
 *
14
 * The above copyright notice and this permission notice shall be included in
15
 * all copies or substantial portions of the Software.
16
 *
17
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23
 * THE SOFTWARE.
24
 */
25

26
#include "qemu/osdep.h"
27
#include "qapi/error.h"
28
#include "qemu/cutils.h"
29
#include "qemu/config-file.h"
30
#include "block/block-io.h"
31
#include "block/block_int.h"
32
#include "block/qdict.h"
33
#include "qemu/module.h"
34
#include "qemu/option.h"
35
#include "qapi/qapi-visit-block-core.h"
36
#include "qapi/qmp/qdict.h"
37
#include "qapi/qmp/qlist.h"
38
#include "qapi/qmp/qstring.h"
39
#include "qapi/qobject-input-visitor.h"
40
#include "sysemu/qtest.h"
41

42
/* All APIs are thread-safe */
43

44
typedef struct BDRVBlkdebugState {
45
    /* IN: initialized in blkdebug_open() and never changed */
46
    uint64_t align;
47
    uint64_t max_transfer;
48
    uint64_t opt_write_zero;
49
    uint64_t max_write_zero;
50
    uint64_t opt_discard;
51
    uint64_t max_discard;
52
    char *config_file; /* For blkdebug_refresh_filename() */
53
    /* initialized in blkdebug_parse_perms() */
54
    uint64_t take_child_perms;
55
    uint64_t unshare_child_perms;
56

57
    /* State. Protected by lock */
58
    int state;
59
    QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
60
    QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
61
    QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
62
    QemuMutex lock;
63
} BDRVBlkdebugState;
64

65
typedef struct BlkdebugAIOCB {
66
    BlockAIOCB common;
67
    int ret;
68
} BlkdebugAIOCB;
69

70
typedef struct BlkdebugSuspendedReq {
71
    /* IN: initialized in suspend_request() */
72
    Coroutine *co;
73
    char *tag;
74

75
    /* List entry protected BDRVBlkdebugState's lock */
76
    QLIST_ENTRY(BlkdebugSuspendedReq) next;
77
} BlkdebugSuspendedReq;
78

79
enum {
80
    ACTION_INJECT_ERROR,
81
    ACTION_SET_STATE,
82
    ACTION_SUSPEND,
83
    ACTION__MAX,
84
};
85

86
typedef struct BlkdebugRule {
87
    /* IN: initialized in add_rule() or blkdebug_debug_breakpoint() */
88
    BlkdebugEvent event;
89
    int action;
90
    int state;
91
    union {
92
        struct {
93
            uint64_t iotype_mask;
94
            int error;
95
            int immediately;
96
            int once;
97
            int64_t offset;
98
        } inject;
99
        struct {
100
            int new_state;
101
        } set_state;
102
        struct {
103
            char *tag;
104
        } suspend;
105
    } options;
106

107
    /* List entries protected BDRVBlkdebugState's lock */
108
    QLIST_ENTRY(BlkdebugRule) next;
109
    QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
110
} BlkdebugRule;
111

112
QEMU_BUILD_BUG_MSG(BLKDEBUG_IO_TYPE__MAX > 64,
113
                   "BlkdebugIOType mask does not fit into an uint64_t");
114

115
static QemuOptsList inject_error_opts = {
116
    .name = "inject-error",
117
    .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
118
    .desc = {
119
        {
120
            .name = "event",
121
            .type = QEMU_OPT_STRING,
122
        },
123
        {
124
            .name = "state",
125
            .type = QEMU_OPT_NUMBER,
126
        },
127
        {
128
            .name = "iotype",
129
            .type = QEMU_OPT_STRING,
130
        },
131
        {
132
            .name = "errno",
133
            .type = QEMU_OPT_NUMBER,
134
        },
135
        {
136
            .name = "sector",
137
            .type = QEMU_OPT_NUMBER,
138
        },
139
        {
140
            .name = "once",
141
            .type = QEMU_OPT_BOOL,
142
        },
143
        {
144
            .name = "immediately",
145
            .type = QEMU_OPT_BOOL,
146
        },
147
        { /* end of list */ }
148
    },
149
};
150

151
static QemuOptsList set_state_opts = {
152
    .name = "set-state",
153
    .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
154
    .desc = {
155
        {
156
            .name = "event",
157
            .type = QEMU_OPT_STRING,
158
        },
159
        {
160
            .name = "state",
161
            .type = QEMU_OPT_NUMBER,
162
        },
163
        {
164
            .name = "new_state",
165
            .type = QEMU_OPT_NUMBER,
166
        },
167
        { /* end of list */ }
168
    },
169
};
170

171
static QemuOptsList *config_groups[] = {
172
    &inject_error_opts,
173
    &set_state_opts,
174
    NULL
175
};
176

177
struct add_rule_data {
178
    BDRVBlkdebugState *s;
179
    int action;
180
};
181

182
static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
183
{
184
    struct add_rule_data *d = opaque;
185
    BDRVBlkdebugState *s = d->s;
186
    const char *event_name;
187
    int event;
188
    struct BlkdebugRule *rule;
189
    int64_t sector;
190
    BlkdebugIOType iotype;
191
    Error *local_error = NULL;
192

193
    /* Find the right event for the rule */
194
    event_name = qemu_opt_get(opts, "event");
195
    if (!event_name) {
196
        error_setg(errp, "Missing event name for rule");
197
        return -1;
198
    }
199
    event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
200
    if (event < 0) {
201
        return -1;
202
    }
203

204
    /* Set attributes common for all actions */
205
    rule = g_malloc0(sizeof(*rule));
206
    *rule = (struct BlkdebugRule) {
207
        .event  = event,
208
        .action = d->action,
209
        .state  = qemu_opt_get_number(opts, "state", 0),
210
    };
211

212
    /* Parse action-specific options */
213
    switch (d->action) {
214
    case ACTION_INJECT_ERROR:
215
        rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
216
        rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
217
        rule->options.inject.immediately =
218
            qemu_opt_get_bool(opts, "immediately", 0);
219
        sector = qemu_opt_get_number(opts, "sector", -1);
220
        rule->options.inject.offset =
221
            sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
222

223
        iotype = qapi_enum_parse(&BlkdebugIOType_lookup,
224
                                 qemu_opt_get(opts, "iotype"),
225
                                 BLKDEBUG_IO_TYPE__MAX, &local_error);
226
        if (local_error) {
227
            error_propagate(errp, local_error);
228
            g_free(rule);
229
            return -1;
230
        }
231
        if (iotype != BLKDEBUG_IO_TYPE__MAX) {
232
            rule->options.inject.iotype_mask = (1ull << iotype);
233
        } else {
234
            /* Apply the default */
235
            rule->options.inject.iotype_mask =
236
                (1ull << BLKDEBUG_IO_TYPE_READ)
237
                | (1ull << BLKDEBUG_IO_TYPE_WRITE)
238
                | (1ull << BLKDEBUG_IO_TYPE_WRITE_ZEROES)
239
                | (1ull << BLKDEBUG_IO_TYPE_DISCARD)
240
                | (1ull << BLKDEBUG_IO_TYPE_FLUSH);
241
        }
242

243
        break;
244

245
    case ACTION_SET_STATE:
246
        rule->options.set_state.new_state =
247
            qemu_opt_get_number(opts, "new_state", 0);
248
        break;
249

250
    case ACTION_SUSPEND:
251
        rule->options.suspend.tag =
252
            g_strdup(qemu_opt_get(opts, "tag"));
253
        break;
254
    };
255

256
    /* Add the rule */
257
    qemu_mutex_lock(&s->lock);
258
    QLIST_INSERT_HEAD(&s->rules[event], rule, next);
259
    qemu_mutex_unlock(&s->lock);
260

261
    return 0;
262
}
263

264
/* Called with lock held or from .bdrv_close */
265
static void remove_rule(BlkdebugRule *rule)
266
{
267
    switch (rule->action) {
268
    case ACTION_INJECT_ERROR:
269
    case ACTION_SET_STATE:
270
        break;
271
    case ACTION_SUSPEND:
272
        g_free(rule->options.suspend.tag);
273
        break;
274
    }
275

276
    QLIST_REMOVE(rule, next);
277
    g_free(rule);
278
}
279

280
static int read_config(BDRVBlkdebugState *s, const char *filename,
281
                       QDict *options, Error **errp)
282
{
283
    FILE *f = NULL;
284
    int ret;
285
    struct add_rule_data d;
286
    Error *local_err = NULL;
287

288
    if (filename) {
289
        f = fopen(filename, "r");
290
        if (f == NULL) {
291
            error_setg_errno(errp, errno, "Could not read blkdebug config file");
292
            return -errno;
293
        }
294

295
        ret = qemu_config_parse(f, config_groups, filename, errp);
296
        if (ret < 0) {
297
            goto fail;
298
        }
299
    }
300

301
    if (!qemu_config_parse_qdict(options, config_groups, errp)) {
302
        ret = -EINVAL;
303
        goto fail;
304
    }
305

306
    d.s = s;
307
    d.action = ACTION_INJECT_ERROR;
308
    qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
309
    if (local_err) {
310
        error_propagate(errp, local_err);
311
        ret = -EINVAL;
312
        goto fail;
313
    }
314

315
    d.action = ACTION_SET_STATE;
316
    qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
317
    if (local_err) {
318
        error_propagate(errp, local_err);
319
        ret = -EINVAL;
320
        goto fail;
321
    }
322

323
    ret = 0;
324
fail:
325
    qemu_opts_reset(&inject_error_opts);
326
    qemu_opts_reset(&set_state_opts);
327
    if (f) {
328
        fclose(f);
329
    }
330
    return ret;
331
}
332

333
/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
334
static void blkdebug_parse_filename(const char *filename, QDict *options,
335
                                    Error **errp)
336
{
337
    const char *c;
338

339
    /* Parse the blkdebug: prefix */
340
    if (!strstart(filename, "blkdebug:", &filename)) {
341
        /* There was no prefix; therefore, all options have to be already
342
           present in the QDict (except for the filename) */
343
        qdict_put_str(options, "x-image", filename);
344
        return;
345
    }
346

347
    /* Parse config file path */
348
    c = strchr(filename, ':');
349
    if (c == NULL) {
350
        error_setg(errp, "blkdebug requires both config file and image path");
351
        return;
352
    }
353

354
    if (c != filename) {
355
        QString *config_path;
356
        config_path = qstring_from_substr(filename, 0, c - filename);
357
        qdict_put(options, "config", config_path);
358
    }
359

360
    /* TODO Allow multi-level nesting and set file.filename here */
361
    filename = c + 1;
362
    qdict_put_str(options, "x-image", filename);
363
}
364

365
static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
366
                                    const char *prefix, Error **errp)
367
{
368
    int ret = 0;
369
    QDict *subqdict = NULL;
370
    QObject *crumpled_subqdict = NULL;
371
    Visitor *v = NULL;
372
    BlockPermissionList *perm_list = NULL, *element;
373

374
    *dest = 0;
375

376
    qdict_extract_subqdict(options, &subqdict, prefix);
377
    if (!qdict_size(subqdict)) {
378
        goto out;
379
    }
380

381
    crumpled_subqdict = qdict_crumple(subqdict, errp);
382
    if (!crumpled_subqdict) {
383
        ret = -EINVAL;
384
        goto out;
385
    }
386

387
    v = qobject_input_visitor_new(crumpled_subqdict);
388
    if (!visit_type_BlockPermissionList(v, NULL, &perm_list, errp)) {
389
        ret = -EINVAL;
390
        goto out;
391
    }
392

393
    for (element = perm_list; element; element = element->next) {
394
        *dest |= bdrv_qapi_perm_to_blk_perm(element->value);
395
    }
396

397
out:
398
    qapi_free_BlockPermissionList(perm_list);
399
    visit_free(v);
400
    qobject_unref(subqdict);
401
    qobject_unref(crumpled_subqdict);
402
    return ret;
403
}
404

405
static int blkdebug_parse_perms(BDRVBlkdebugState *s, QDict *options,
406
                                Error **errp)
407
{
408
    int ret;
409

410
    ret = blkdebug_parse_perm_list(&s->take_child_perms, options,
411
                                   "take-child-perms.", errp);
412
    if (ret < 0) {
413
        return ret;
414
    }
415

416
    ret = blkdebug_parse_perm_list(&s->unshare_child_perms, options,
417
                                   "unshare-child-perms.", errp);
418
    if (ret < 0) {
419
        return ret;
420
    }
421

422
    return 0;
423
}
424

425
static QemuOptsList runtime_opts = {
426
    .name = "blkdebug",
427
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
428
    .desc = {
429
        {
430
            .name = "config",
431
            .type = QEMU_OPT_STRING,
432
            .help = "Path to the configuration file",
433
        },
434
        {
435
            .name = "x-image",
436
            .type = QEMU_OPT_STRING,
437
            .help = "[internal use only, will be removed]",
438
        },
439
        {
440
            .name = "align",
441
            .type = QEMU_OPT_SIZE,
442
            .help = "Required alignment in bytes",
443
        },
444
        {
445
            .name = "max-transfer",
446
            .type = QEMU_OPT_SIZE,
447
            .help = "Maximum transfer size in bytes",
448
        },
449
        {
450
            .name = "opt-write-zero",
451
            .type = QEMU_OPT_SIZE,
452
            .help = "Optimum write zero alignment in bytes",
453
        },
454
        {
455
            .name = "max-write-zero",
456
            .type = QEMU_OPT_SIZE,
457
            .help = "Maximum write zero size in bytes",
458
        },
459
        {
460
            .name = "opt-discard",
461
            .type = QEMU_OPT_SIZE,
462
            .help = "Optimum discard alignment in bytes",
463
        },
464
        {
465
            .name = "max-discard",
466
            .type = QEMU_OPT_SIZE,
467
            .help = "Maximum discard size in bytes",
468
        },
469
        { /* end of list */ }
470
    },
471
};
472

473
static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
474
                         Error **errp)
475
{
476
    BDRVBlkdebugState *s = bs->opaque;
477
    QemuOpts *opts;
478
    int ret;
479
    uint64_t align;
480

481
    qemu_mutex_init(&s->lock);
482
    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
483
    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
484
        ret = -EINVAL;
485
        goto out;
486
    }
487

488
    /* Read rules from config file or command line options */
489
    s->config_file = g_strdup(qemu_opt_get(opts, "config"));
490
    ret = read_config(s, s->config_file, options, errp);
491
    if (ret) {
492
        goto out;
493
    }
494

495
    /* Set initial state */
496
    s->state = 1;
497

498
    /* Parse permissions modifiers before opening the image file */
499
    ret = blkdebug_parse_perms(s, options, errp);
500
    if (ret < 0) {
501
        goto out;
502
    }
503

504
    /* Open the image file */
505
    ret = bdrv_open_file_child(qemu_opt_get(opts, "x-image"), options, "image",
506
                               bs, errp);
507
    if (ret < 0) {
508
        goto out;
509
    }
510

511
    bdrv_graph_rdlock_main_loop();
512

513
    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
514
        (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
515
    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
516
        ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
517
            bs->file->bs->supported_zero_flags);
518
    ret = -EINVAL;
519

520
    /* Set alignment overrides */
521
    s->align = qemu_opt_get_size(opts, "align", 0);
522
    if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
523
        error_setg(errp, "Cannot meet constraints with align %" PRIu64,
524
                   s->align);
525
        goto out_rdlock;
526
    }
527
    align = MAX(s->align, bs->file->bs->bl.request_alignment);
528

529
    s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
530
    if (s->max_transfer &&
531
        (s->max_transfer >= INT_MAX ||
532
         !QEMU_IS_ALIGNED(s->max_transfer, align))) {
533
        error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
534
                   s->max_transfer);
535
        goto out_rdlock;
536
    }
537

538
    s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
539
    if (s->opt_write_zero &&
540
        (s->opt_write_zero >= INT_MAX ||
541
         !QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
542
        error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
543
                   s->opt_write_zero);
544
        goto out_rdlock;
545
    }
546

547
    s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
548
    if (s->max_write_zero &&
549
        (s->max_write_zero >= INT_MAX ||
550
         !QEMU_IS_ALIGNED(s->max_write_zero,
551
                          MAX(s->opt_write_zero, align)))) {
552
        error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
553
                   s->max_write_zero);
554
        goto out_rdlock;
555
    }
556

557
    s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
558
    if (s->opt_discard &&
559
        (s->opt_discard >= INT_MAX ||
560
         !QEMU_IS_ALIGNED(s->opt_discard, align))) {
561
        error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
562
                   s->opt_discard);
563
        goto out_rdlock;
564
    }
565

566
    s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
567
    if (s->max_discard &&
568
        (s->max_discard >= INT_MAX ||
569
         !QEMU_IS_ALIGNED(s->max_discard,
570
                          MAX(s->opt_discard, align)))) {
571
        error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
572
                   s->max_discard);
573
        goto out_rdlock;
574
    }
575

576
    bdrv_debug_event(bs, BLKDBG_NONE);
577

578
    ret = 0;
579
out_rdlock:
580
    bdrv_graph_rdunlock_main_loop();
581
out:
582
    if (ret < 0) {
583
        qemu_mutex_destroy(&s->lock);
584
        g_free(s->config_file);
585
    }
586
    qemu_opts_del(opts);
587
    return ret;
588
}
589

590
static int coroutine_fn rule_check(BlockDriverState *bs, uint64_t offset,
591
                                   uint64_t bytes, BlkdebugIOType iotype)
592
{
593
    BDRVBlkdebugState *s = bs->opaque;
594
    BlkdebugRule *rule = NULL;
595
    int error;
596
    bool immediately;
597

598
    qemu_mutex_lock(&s->lock);
599
    QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
600
        uint64_t inject_offset = rule->options.inject.offset;
601

602
        if ((inject_offset == -1 ||
603
             (bytes && inject_offset >= offset &&
604
              inject_offset < offset + bytes)) &&
605
            (rule->options.inject.iotype_mask & (1ull << iotype)))
606
        {
607
            break;
608
        }
609
    }
610

611
    if (!rule || !rule->options.inject.error) {
612
        qemu_mutex_unlock(&s->lock);
613
        return 0;
614
    }
615

616
    immediately = rule->options.inject.immediately;
617
    error = rule->options.inject.error;
618

619
    if (rule->options.inject.once) {
620
        QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
621
        remove_rule(rule);
622
    }
623

624
    qemu_mutex_unlock(&s->lock);
625
    if (!immediately) {
626
        aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
627
        qemu_coroutine_yield();
628
    }
629

630
    return -error;
631
}
632

633
static int coroutine_fn GRAPH_RDLOCK
634
blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
635
                   QEMUIOVector *qiov, BdrvRequestFlags flags)
636
{
637
    int err;
638

639
    /* Sanity check block layer guarantees */
640
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
641
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
642
    if (bs->bl.max_transfer) {
643
        assert(bytes <= bs->bl.max_transfer);
644
    }
645

646
    err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_READ);
647
    if (err) {
648
        return err;
649
    }
650

651
    return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
652
}
653

654
static int coroutine_fn GRAPH_RDLOCK
655
blkdebug_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
656
                    QEMUIOVector *qiov, BdrvRequestFlags flags)
657
{
658
    int err;
659

660
    /* Sanity check block layer guarantees */
661
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
662
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
663
    if (bs->bl.max_transfer) {
664
        assert(bytes <= bs->bl.max_transfer);
665
    }
666

667
    err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE);
668
    if (err) {
669
        return err;
670
    }
671

672
    return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
673
}
674

675
static int GRAPH_RDLOCK coroutine_fn blkdebug_co_flush(BlockDriverState *bs)
676
{
677
    int err = rule_check(bs, 0, 0, BLKDEBUG_IO_TYPE_FLUSH);
678

679
    if (err) {
680
        return err;
681
    }
682

683
    return bdrv_co_flush(bs->file->bs);
684
}
685

686
static int coroutine_fn GRAPH_RDLOCK
687
blkdebug_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
688
                          BdrvRequestFlags flags)
689
{
690
    uint32_t align = MAX(bs->bl.request_alignment,
691
                         bs->bl.pwrite_zeroes_alignment);
692
    int err;
693

694
    /* Only pass through requests that are larger than requested
695
     * preferred alignment (so that we test the fallback to writes on
696
     * unaligned portions), and check that the block layer never hands
697
     * us anything unaligned that crosses an alignment boundary.  */
698
    if (bytes < align) {
699
        assert(QEMU_IS_ALIGNED(offset, align) ||
700
               QEMU_IS_ALIGNED(offset + bytes, align) ||
701
               DIV_ROUND_UP(offset, align) ==
702
               DIV_ROUND_UP(offset + bytes, align));
703
        return -ENOTSUP;
704
    }
705
    assert(QEMU_IS_ALIGNED(offset, align));
706
    assert(QEMU_IS_ALIGNED(bytes, align));
707
    if (bs->bl.max_pwrite_zeroes) {
708
        assert(bytes <= bs->bl.max_pwrite_zeroes);
709
    }
710

711
    err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE_ZEROES);
712
    if (err) {
713
        return err;
714
    }
715

716
    return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
717
}
718

719
static int coroutine_fn GRAPH_RDLOCK
720
blkdebug_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
721
{
722
    uint32_t align = bs->bl.pdiscard_alignment;
723
    int err;
724

725
    /* Only pass through requests that are larger than requested
726
     * minimum alignment, and ensure that unaligned requests do not
727
     * cross optimum discard boundaries. */
728
    if (bytes < bs->bl.request_alignment) {
729
        assert(QEMU_IS_ALIGNED(offset, align) ||
730
               QEMU_IS_ALIGNED(offset + bytes, align) ||
731
               DIV_ROUND_UP(offset, align) ==
732
               DIV_ROUND_UP(offset + bytes, align));
733
        return -ENOTSUP;
734
    }
735
    assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
736
    assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
737
    if (align && bytes >= align) {
738
        assert(QEMU_IS_ALIGNED(offset, align));
739
        assert(QEMU_IS_ALIGNED(bytes, align));
740
    }
741
    if (bs->bl.max_pdiscard) {
742
        assert(bytes <= bs->bl.max_pdiscard);
743
    }
744

745
    err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_DISCARD);
746
    if (err) {
747
        return err;
748
    }
749

750
    return bdrv_co_pdiscard(bs->file, offset, bytes);
751
}
752

753
static int coroutine_fn GRAPH_RDLOCK
754
blkdebug_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
755
                         int64_t bytes, int64_t *pnum, int64_t *map,
756
                         BlockDriverState **file)
757
{
758
    int err;
759

760
    assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
761

762
    err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_BLOCK_STATUS);
763
    if (err) {
764
        return err;
765
    }
766

767
    assert(bs->file && bs->file->bs);
768
    *pnum = bytes;
769
    *map = offset;
770
    *file = bs->file->bs;
771
    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
772
}
773

774
static void blkdebug_close(BlockDriverState *bs)
775
{
776
    BDRVBlkdebugState *s = bs->opaque;
777
    BlkdebugRule *rule, *next;
778
    int i;
779

780
    for (i = 0; i < BLKDBG__MAX; i++) {
781
        QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
782
            remove_rule(rule);
783
        }
784
    }
785

786
    g_free(s->config_file);
787
    qemu_mutex_destroy(&s->lock);
788
}
789

790
/* Called with lock held.  */
791
static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
792
{
793
    BDRVBlkdebugState *s = bs->opaque;
794
    BlkdebugSuspendedReq *r;
795

796
    r = g_new(BlkdebugSuspendedReq, 1);
797

798
    r->co         = qemu_coroutine_self();
799
    r->tag        = g_strdup(rule->options.suspend.tag);
800

801
    remove_rule(rule);
802
    QLIST_INSERT_HEAD(&s->suspended_reqs, r, next);
803

804
    if (!qtest_enabled()) {
805
        printf("blkdebug: Suspended request '%s'\n", r->tag);
806
    }
807
}
808

809
/* Called with lock held.  */
810
static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
811
                         int *action_count, int *new_state)
812
{
813
    BDRVBlkdebugState *s = bs->opaque;
814

815
    /* Only process rules for the current state */
816
    if (rule->state && rule->state != s->state) {
817
        return;
818
    }
819

820
    /* Take the action */
821
    action_count[rule->action]++;
822
    switch (rule->action) {
823
    case ACTION_INJECT_ERROR:
824
        if (action_count[ACTION_INJECT_ERROR] == 1) {
825
            QSIMPLEQ_INIT(&s->active_rules);
826
        }
827
        QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
828
        break;
829

830
    case ACTION_SET_STATE:
831
        *new_state = rule->options.set_state.new_state;
832
        break;
833

834
    case ACTION_SUSPEND:
835
        suspend_request(bs, rule);
836
        break;
837
    }
838
}
839

840
static void coroutine_fn
841
blkdebug_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
842
{
843
    BDRVBlkdebugState *s = bs->opaque;
844
    struct BlkdebugRule *rule, *next;
845
    int new_state;
846
    int actions_count[ACTION__MAX] = { 0 };
847

848
    assert((int)event >= 0 && event < BLKDBG__MAX);
849

850
    WITH_QEMU_LOCK_GUARD(&s->lock) {
851
        new_state = s->state;
852
        QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
853
            process_rule(bs, rule, actions_count, &new_state);
854
        }
855
        s->state = new_state;
856
    }
857

858
    while (actions_count[ACTION_SUSPEND] > 0) {
859
        qemu_coroutine_yield();
860
        actions_count[ACTION_SUSPEND]--;
861
    }
862
}
863

864
static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
865
                                     const char *tag)
866
{
867
    BDRVBlkdebugState *s = bs->opaque;
868
    struct BlkdebugRule *rule;
869
    int blkdebug_event;
870

871
    blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
872
    if (blkdebug_event < 0) {
873
        return -ENOENT;
874
    }
875

876
    rule = g_malloc(sizeof(*rule));
877
    *rule = (struct BlkdebugRule) {
878
        .event  = blkdebug_event,
879
        .action = ACTION_SUSPEND,
880
        .state  = 0,
881
        .options.suspend.tag = g_strdup(tag),
882
    };
883

884
    qemu_mutex_lock(&s->lock);
885
    QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
886
    qemu_mutex_unlock(&s->lock);
887

888
    return 0;
889
}
890

891
/* Called with lock held. May temporarily release lock. */
892
static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool all)
893
{
894
    BlkdebugSuspendedReq *r;
895

896
retry:
897
    /*
898
     * No need for _SAFE, since a different coroutine can remove another node
899
     * (not the current one) in this list, and when the current one is removed
900
     * the iteration starts back from beginning anyways.
901
     */
902
    QLIST_FOREACH(r, &s->suspended_reqs, next) {
903
        if (!strcmp(r->tag, tag)) {
904
            Coroutine *co = r->co;
905

906
            if (!qtest_enabled()) {
907
                printf("blkdebug: Resuming request '%s'\n", r->tag);
908
            }
909

910
            QLIST_REMOVE(r, next);
911
            g_free(r->tag);
912
            g_free(r);
913

914
            qemu_mutex_unlock(&s->lock);
915
            qemu_coroutine_enter(co);
916
            qemu_mutex_lock(&s->lock);
917

918
            if (all) {
919
                goto retry;
920
            }
921
            return 0;
922
        }
923
    }
924
    return -ENOENT;
925
}
926

927
static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
928
{
929
    BDRVBlkdebugState *s = bs->opaque;
930
    QEMU_LOCK_GUARD(&s->lock);
931
    return resume_req_by_tag(s, tag, false);
932
}
933

934
static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
935
                                            const char *tag)
936
{
937
    BDRVBlkdebugState *s = bs->opaque;
938
    BlkdebugRule *rule, *next;
939
    int i, ret = -ENOENT;
940

941
    QEMU_LOCK_GUARD(&s->lock);
942
    for (i = 0; i < BLKDBG__MAX; i++) {
943
        QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
944
            if (rule->action == ACTION_SUSPEND &&
945
                !strcmp(rule->options.suspend.tag, tag)) {
946
                remove_rule(rule);
947
                ret = 0;
948
            }
949
        }
950
    }
951
    if (resume_req_by_tag(s, tag, true) == 0) {
952
        ret = 0;
953
    }
954
    return ret;
955
}
956

957
static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
958
{
959
    BDRVBlkdebugState *s = bs->opaque;
960
    BlkdebugSuspendedReq *r;
961

962
    QEMU_LOCK_GUARD(&s->lock);
963
    QLIST_FOREACH(r, &s->suspended_reqs, next) {
964
        if (!strcmp(r->tag, tag)) {
965
            return true;
966
        }
967
    }
968
    return false;
969
}
970

971
static int64_t coroutine_fn GRAPH_RDLOCK
972
blkdebug_co_getlength(BlockDriverState *bs)
973
{
974
    return bdrv_co_getlength(bs->file->bs);
975
}
976

977
static void GRAPH_RDLOCK blkdebug_refresh_filename(BlockDriverState *bs)
978
{
979
    BDRVBlkdebugState *s = bs->opaque;
980
    const QDictEntry *e;
981
    int ret;
982

983
    if (!bs->file->bs->exact_filename[0]) {
984
        return;
985
    }
986

987
    for (e = qdict_first(bs->full_open_options); e;
988
         e = qdict_next(bs->full_open_options, e))
989
    {
990
        /* Real child options are under "image", but "x-image" may
991
         * contain a filename */
992
        if (strcmp(qdict_entry_key(e), "config") &&
993
            strcmp(qdict_entry_key(e), "image") &&
994
            strcmp(qdict_entry_key(e), "x-image") &&
995
            strcmp(qdict_entry_key(e), "driver"))
996
        {
997
            return;
998
        }
999
    }
1000

1001
    ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
1002
                   "blkdebug:%s:%s",
1003
                   s->config_file ?: "", bs->file->bs->exact_filename);
1004
    if (ret >= sizeof(bs->exact_filename)) {
1005
        /* An overflow makes the filename unusable, so do not report any */
1006
        bs->exact_filename[0] = 0;
1007
    }
1008
}
1009

1010
static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
1011
{
1012
    BDRVBlkdebugState *s = bs->opaque;
1013

1014
    if (s->align) {
1015
        bs->bl.request_alignment = s->align;
1016
    }
1017
    if (s->max_transfer) {
1018
        bs->bl.max_transfer = s->max_transfer;
1019
    }
1020
    if (s->opt_write_zero) {
1021
        bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
1022
    }
1023
    if (s->max_write_zero) {
1024
        bs->bl.max_pwrite_zeroes = s->max_write_zero;
1025
    }
1026
    if (s->opt_discard) {
1027
        bs->bl.pdiscard_alignment = s->opt_discard;
1028
    }
1029
    if (s->max_discard) {
1030
        bs->bl.max_pdiscard = s->max_discard;
1031
    }
1032
}
1033

1034
static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
1035
                                   BlockReopenQueue *queue, Error **errp)
1036
{
1037
    return 0;
1038
}
1039

1040
static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c,
1041
                                BdrvChildRole role,
1042
                                BlockReopenQueue *reopen_queue,
1043
                                uint64_t perm, uint64_t shared,
1044
                                uint64_t *nperm, uint64_t *nshared)
1045
{
1046
    BDRVBlkdebugState *s = bs->opaque;
1047

1048
    bdrv_default_perms(bs, c, role, reopen_queue,
1049
                       perm, shared, nperm, nshared);
1050

1051
    *nperm |= s->take_child_perms;
1052
    *nshared &= ~s->unshare_child_perms;
1053
}
1054

1055
static const char *const blkdebug_strong_runtime_opts[] = {
1056
    "config",
1057
    "inject-error.",
1058
    "set-state.",
1059
    "align",
1060
    "max-transfer",
1061
    "opt-write-zero",
1062
    "max-write-zero",
1063
    "opt-discard",
1064
    "max-discard",
1065

1066
    NULL
1067
};
1068

1069
static BlockDriver bdrv_blkdebug = {
1070
    .format_name            = "blkdebug",
1071
    .protocol_name          = "blkdebug",
1072
    .instance_size          = sizeof(BDRVBlkdebugState),
1073
    .is_filter              = true,
1074

1075
    .bdrv_parse_filename    = blkdebug_parse_filename,
1076
    .bdrv_open              = blkdebug_open,
1077
    .bdrv_close             = blkdebug_close,
1078
    .bdrv_reopen_prepare    = blkdebug_reopen_prepare,
1079
    .bdrv_child_perm        = blkdebug_child_perm,
1080

1081
    .bdrv_co_getlength      = blkdebug_co_getlength,
1082
    .bdrv_refresh_filename  = blkdebug_refresh_filename,
1083
    .bdrv_refresh_limits    = blkdebug_refresh_limits,
1084

1085
    .bdrv_co_preadv         = blkdebug_co_preadv,
1086
    .bdrv_co_pwritev        = blkdebug_co_pwritev,
1087
    .bdrv_co_flush_to_disk  = blkdebug_co_flush,
1088
    .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
1089
    .bdrv_co_pdiscard       = blkdebug_co_pdiscard,
1090
    .bdrv_co_block_status   = blkdebug_co_block_status,
1091

1092
    .bdrv_co_debug_event        = blkdebug_co_debug_event,
1093
    .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
1094
    .bdrv_debug_remove_breakpoint
1095
                                = blkdebug_debug_remove_breakpoint,
1096
    .bdrv_debug_resume          = blkdebug_debug_resume,
1097
    .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
1098

1099
    .strong_runtime_opts        = blkdebug_strong_runtime_opts,
1100
};
1101

1102
static void bdrv_blkdebug_init(void)
1103
{
1104
    bdrv_register(&bdrv_blkdebug);
1105
}
1106

1107
block_init(bdrv_blkdebug_init);
1108