block/blkdebug.c

   1 /*
   2  * Block protocol for I/O error injection
   3  *
   4  * Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu-common.h"
  26 #include "qemu/config-file.h"
  27 #include "block/block_int.h"
  28 #include "qemu/module.h"
  29 #include "qapi/qmp/qbool.h"
  30 #include "qapi/qmp/qdict.h"
  31 #include "qapi/qmp/qint.h"
  32 #include "qapi/qmp/qstring.h"
  33
  34 typedef struct BDRVBlkdebugState {
  35     int state;
  36     int new_state;
  37
  38     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
  39     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  40     QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
  41 } BDRVBlkdebugState;
  42
  43 typedef struct BlkdebugAIOCB {
  44     BlockAIOCB common;
  45     QEMUBH *bh;
  46     int ret;
  47 } BlkdebugAIOCB;
  48
  49 typedef struct BlkdebugSuspendedReq {
  50     Coroutine *co;
  51     char *tag;
  52     QLIST_ENTRY(BlkdebugSuspendedReq) next;
  53 } BlkdebugSuspendedReq;
  54
  55 static const AIOCBInfo blkdebug_aiocb_info = {
  56     .aiocb_size    = sizeof(BlkdebugAIOCB),
  57 };
  58
  59 enum {
  60     ACTION_INJECT_ERROR,
  61     ACTION_SET_STATE,
  62     ACTION_SUSPEND,
  63 };
  64
  65 typedef struct BlkdebugRule {
  66     BlkDebugEvent event;
  67     int action;
  68     int state;
  69     union {
  70         struct {
  71             int error;
  72             int immediately;
  73             int once;
  74             int64_t sector;
  75         } inject;
  76         struct {
  77             int new_state;
  78         } set_state;
  79         struct {
  80             char *tag;
  81         } suspend;
  82     } options;
  83     QLIST_ENTRY(BlkdebugRule) next;
  84     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
  85 } BlkdebugRule;
  86
  87 static QemuOptsList inject_error_opts = {
  88     .name = "inject-error",
  89     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
  90     .desc = {
  91         {
  92             .name = "event",
  93             .type = QEMU_OPT_STRING,
  94         },
  95         {
  96             .name = "state",
  97             .type = QEMU_OPT_NUMBER,
  98         },
  99         {
 100             .name = "errno",
 101             .type = QEMU_OPT_NUMBER,
 102         },
 103         {
 104             .name = "sector",
 105             .type = QEMU_OPT_NUMBER,
 106         },
 107         {
 108             .name = "once",
 109             .type = QEMU_OPT_BOOL,
 110         },
 111         {
 112             .name = "immediately",
 113             .type = QEMU_OPT_BOOL,
 114         },
 115         { /* end of list */ }
 116     },
 117 };
 118
 119 static QemuOptsList set_state_opts = {
 120     .name = "set-state",
 121     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 122     .desc = {
 123         {
 124             .name = "event",
 125             .type = QEMU_OPT_STRING,
 126         },
 127         {
 128             .name = "state",
 129             .type = QEMU_OPT_NUMBER,
 130         },
 131         {
 132             .name = "new_state",
 133             .type = QEMU_OPT_NUMBER,
 134         },
 135         { /* end of list */ }
 136     },
 137 };
 138
 139 static QemuOptsList *config_groups[] = {
 140     &inject_error_opts,
 141     &set_state_opts,
 142     NULL
 143 };
 144
 145 static const char *event_names[BLKDBG_EVENT_MAX] = {
 146     [BLKDBG_L1_UPDATE]                      = "l1_update",
 147     [BLKDBG_L1_GROW_ALLOC_TABLE]            = "l1_grow.alloc_table",
 148     [BLKDBG_L1_GROW_WRITE_TABLE]            = "l1_grow.write_table",
 149     [BLKDBG_L1_GROW_ACTIVATE_TABLE]         = "l1_grow.activate_table",
 150
 151     [BLKDBG_L2_LOAD]                        = "l2_load",
 152     [BLKDBG_L2_UPDATE]                      = "l2_update",
 153     [BLKDBG_L2_UPDATE_COMPRESSED]           = "l2_update_compressed",
 154     [BLKDBG_L2_ALLOC_COW_READ]              = "l2_alloc.cow_read",
 155     [BLKDBG_L2_ALLOC_WRITE]                 = "l2_alloc.write",
 156
 157     [BLKDBG_READ_AIO]                       = "read_aio",
 158     [BLKDBG_READ_BACKING_AIO]               = "read_backing_aio",
 159     [BLKDBG_READ_COMPRESSED]                = "read_compressed",
 160
 161     [BLKDBG_WRITE_AIO]                      = "write_aio",
 162     [BLKDBG_WRITE_COMPRESSED]               = "write_compressed",
 163
 164     [BLKDBG_VMSTATE_LOAD]                   = "vmstate_load",
 165     [BLKDBG_VMSTATE_SAVE]                   = "vmstate_save",
 166
 167     [BLKDBG_COW_READ]                       = "cow_read",
 168     [BLKDBG_COW_WRITE]                      = "cow_write",
 169
 170     [BLKDBG_REFTABLE_LOAD]                  = "reftable_load",
 171     [BLKDBG_REFTABLE_GROW]                  = "reftable_grow",
 172     [BLKDBG_REFTABLE_UPDATE]                = "reftable_update",
 173
 174     [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
 175     [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
 176     [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
 177     [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
 178     [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
 179     [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
 180     [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
 181     [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
 182     [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
 183
 184     [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
 185     [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
 186     [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 187
 188     [BLKDBG_FLUSH_TO_OS]                    = "flush_to_os",
 189     [BLKDBG_FLUSH_TO_DISK]                  = "flush_to_disk",
 190
 191     [BLKDBG_PWRITEV_RMW_HEAD]               = "pwritev_rmw.head",
 192     [BLKDBG_PWRITEV_RMW_AFTER_HEAD]         = "pwritev_rmw.after_head",
 193     [BLKDBG_PWRITEV_RMW_TAIL]               = "pwritev_rmw.tail",
 194     [BLKDBG_PWRITEV_RMW_AFTER_TAIL]         = "pwritev_rmw.after_tail",
 195     [BLKDBG_PWRITEV]                        = "pwritev",
 196     [BLKDBG_PWRITEV_ZERO]                   = "pwritev_zero",
 197     [BLKDBG_PWRITEV_DONE]                   = "pwritev_done",
 198
 199     [BLKDBG_EMPTY_IMAGE_PREPARE]            = "empty_image_prepare",
 200 };
 201
 202 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 203 {
 204     int i;
 205
 206     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 207         if (!strcmp(event_names[i], name)) {
 208             *event = i;
 209             return 0;
 210         }
 211     }
 212
 213     return -1;
 214 }
 215
 216 struct add_rule_data {
 217     BDRVBlkdebugState *s;
 218     int action;
 219     Error **errp;
 220 };
 221
 222 static int add_rule(QemuOpts *opts, void *opaque)
 223 {
 224     struct add_rule_data *d = opaque;
 225     BDRVBlkdebugState *s = d->s;
 226     const char* event_name;
 227     BlkDebugEvent event;
 228     struct BlkdebugRule *rule;
 229
 230     /* Find the right event for the rule */
 231     event_name = qemu_opt_get(opts, "event");
 232     if (!event_name) {
 233         error_setg(d->errp, "Missing event name for rule");
 234         return -1;
 235     } else if (get_event_by_name(event_name, &event) < 0) {
 236         error_setg(d->errp, "Invalid event name \"%s\"", event_name);
 237         return -1;
 238     }
 239
 240     /* Set attributes common for all actions */
 241     rule = g_malloc0(sizeof(*rule));
 242     *rule = (struct BlkdebugRule) {
 243         .event  = event,
 244         .action = d->action,
 245         .state  = qemu_opt_get_number(opts, "state", 0),
 246     };
 247
 248     /* Parse action-specific options */
 249     switch (d->action) {
 250     case ACTION_INJECT_ERROR:
 251         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 252         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 253         rule->options.inject.immediately =
 254             qemu_opt_get_bool(opts, "immediately", 0);
 255         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 256         break;
 257
 258     case ACTION_SET_STATE:
 259         rule->options.set_state.new_state =
 260             qemu_opt_get_number(opts, "new_state", 0);
 261         break;
 262
 263     case ACTION_SUSPEND:
 264         rule->options.suspend.tag =
 265             g_strdup(qemu_opt_get(opts, "tag"));
 266         break;
 267     };
 268
 269     /* Add the rule */
 270     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 271
 272     return 0;
 273 }
 274
 275 static void remove_rule(BlkdebugRule *rule)
 276 {
 277     switch (rule->action) {
 278     case ACTION_INJECT_ERROR:
 279     case ACTION_SET_STATE:
 280         break;
 281     case ACTION_SUSPEND:
 282         g_free(rule->options.suspend.tag);
 283         break;
 284     }
 285
 286     QLIST_REMOVE(rule, next);
 287     g_free(rule);
 288 }
 289
 290 static int read_config(BDRVBlkdebugState *s, const char *filename,
 291                        QDict *options, Error **errp)
 292 {
 293     FILE *f = NULL;
 294     int ret;
 295     struct add_rule_data d;
 296     Error *local_err = NULL;
 297
 298     if (filename) {
 299         f = fopen(filename, "r");
 300         if (f == NULL) {
 301             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 302             return -errno;
 303         }
 304
 305         ret = qemu_config_parse(f, config_groups, filename);
 306         if (ret < 0) {
 307             error_setg(errp, "Could not parse blkdebug config file");
 308             ret = -EINVAL;
 309             goto fail;
 310         }
 311     }
 312
 313     qemu_config_parse_qdict(options, config_groups, &local_err);
 314     if (local_err) {
 315         error_propagate(errp, local_err);
 316         ret = -EINVAL;
 317         goto fail;
 318     }
 319
 320     d.s = s;
 321     d.action = ACTION_INJECT_ERROR;
 322     d.errp = &local_err;
 323     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 1);
 324     if (local_err) {
 325         error_propagate(errp, local_err);
 326         ret = -EINVAL;
 327         goto fail;
 328     }
 329
 330     d.action = ACTION_SET_STATE;
 331     qemu_opts_foreach(&set_state_opts, add_rule, &d, 1);
 332     if (local_err) {
 333         error_propagate(errp, local_err);
 334         ret = -EINVAL;
 335         goto fail;
 336     }
 337
 338     ret = 0;
 339 fail:
 340     qemu_opts_reset(&inject_error_opts);
 341     qemu_opts_reset(&set_state_opts);
 342     if (f) {
 343         fclose(f);
 344     }
 345     return ret;
 346 }
 347
 348 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 349 static void blkdebug_parse_filename(const char *filename, QDict *options,
 350                                     Error **errp)
 351 {
 352     const char *c;
 353
 354     /* Parse the blkdebug: prefix */
 355     if (!strstart(filename, "blkdebug:", &filename)) {
 356         /* There was no prefix; therefore, all options have to be already
 357            present in the QDict (except for the filename) */
 358         qdict_put(options, "x-image", qstring_from_str(filename));
 359         return;
 360     }
 361
 362     /* Parse config file path */
 363     c = strchr(filename, ':');
 364     if (c == NULL) {
 365         error_setg(errp, "blkdebug requires both config file and image path");
 366         return;
 367     }
 368
 369     if (c != filename) {
 370         QString *config_path;
 371         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 372         qdict_put(options, "config", config_path);
 373     }
 374
 375     /* TODO Allow multi-level nesting and set file.filename here */
 376     filename = c + 1;
 377     qdict_put(options, "x-image", qstring_from_str(filename));
 378 }
 379
 380 static QemuOptsList runtime_opts = {
 381     .name = "blkdebug",
 382     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 383     .desc = {
 384         {
 385             .name = "config",
 386             .type = QEMU_OPT_STRING,
 387             .help = "Path to the configuration file",
 388         },
 389         {
 390             .name = "x-image",
 391             .type = QEMU_OPT_STRING,
 392             .help = "[internal use only, will be removed]",
 393         },
 394         {
 395             .name = "align",
 396             .type = QEMU_OPT_SIZE,
 397             .help = "Required alignment in bytes",
 398         },
 399         { /* end of list */ }
 400     },
 401 };
 402
 403 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 404                          Error **errp)
 405 {
 406     BDRVBlkdebugState *s = bs->opaque;
 407     QemuOpts *opts;
 408     Error *local_err = NULL;
 409     const char *config;
 410     uint64_t align;
 411     int ret;
 412
 413     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 414     qemu_opts_absorb_qdict(opts, options, &local_err);
 415     if (local_err) {
 416         error_propagate(errp, local_err);
 417         ret = -EINVAL;
 418         goto out;
 419     }
 420
 421     /* Read rules from config file or command line options */
 422     config = qemu_opt_get(opts, "config");
 423     ret = read_config(s, config, options, errp);
 424     if (ret) {
 425         goto out;
 426     }
 427
 428     /* Set initial state */
 429     s->state = 1;
 430
 431     /* Open the backing file */
 432     assert(bs->file == NULL);
 433     ret = bdrv_open_image(&bs->file, qemu_opt_get(opts, "x-image"), options, "image",
 434                           flags | BDRV_O_PROTOCOL, false, &local_err);
 435     if (ret < 0) {
 436         error_propagate(errp, local_err);
 437         goto out;
 438     }
 439
 440     /* Set request alignment */
 441     align = qemu_opt_get_size(opts, "align", bs->request_alignment);
 442     if (align > 0 && align < INT_MAX && !(align & (align - 1))) {
 443         bs->request_alignment = align;
 444     } else {
 445         error_setg(errp, "Invalid alignment");
 446         ret = -EINVAL;
 447         goto fail_unref;
 448     }
 449
 450     ret = 0;
 451     goto out;
 452
 453 fail_unref:
 454     bdrv_unref(bs->file);
 455 out:
 456     qemu_opts_del(opts);
 457     return ret;
 458 }
 459
 460 static void error_callback_bh(void *opaque)
 461 {
 462     struct BlkdebugAIOCB *acb = opaque;
 463     qemu_bh_delete(acb->bh);
 464     acb->common.cb(acb->common.opaque, acb->ret);
 465     qemu_aio_unref(acb);
 466 }
 467
 468 static BlockAIOCB *inject_error(BlockDriverState *bs,
 469     BlockCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 470 {
 471     BDRVBlkdebugState *s = bs->opaque;
 472     int error = rule->options.inject.error;
 473     struct BlkdebugAIOCB *acb;
 474     QEMUBH *bh;
 475
 476     if (rule->options.inject.once) {
 477         QSIMPLEQ_INIT(&s->active_rules);
 478     }
 479
 480     if (rule->options.inject.immediately) {
 481         return NULL;
 482     }
 483
 484     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 485     acb->ret = -error;
 486
 487     bh = aio_bh_new(bdrv_get_aio_context(bs), error_callback_bh, acb);
 488     acb->bh = bh;
 489     qemu_bh_schedule(bh);
 490
 491     return &acb->common;
 492 }
 493
 494 static BlockAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 495     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 496     BlockCompletionFunc *cb, void *opaque)
 497 {
 498     BDRVBlkdebugState *s = bs->opaque;
 499     BlkdebugRule *rule = NULL;
 500
 501     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 502         if (rule->options.inject.sector == -1 ||
 503             (rule->options.inject.sector >= sector_num &&
 504              rule->options.inject.sector < sector_num + nb_sectors)) {
 505             break;
 506         }
 507     }
 508
 509     if (rule && rule->options.inject.error) {
 510         return inject_error(bs, cb, opaque, rule);
 511     }
 512
 513     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 514 }
 515
 516 static BlockAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 517     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 518     BlockCompletionFunc *cb, void *opaque)
 519 {
 520     BDRVBlkdebugState *s = bs->opaque;
 521     BlkdebugRule *rule = NULL;
 522
 523     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 524         if (rule->options.inject.sector == -1 ||
 525             (rule->options.inject.sector >= sector_num &&
 526              rule->options.inject.sector < sector_num + nb_sectors)) {
 527             break;
 528         }
 529     }
 530
 531     if (rule && rule->options.inject.error) {
 532         return inject_error(bs, cb, opaque, rule);
 533     }
 534
 535     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 536 }
 537
 538 static BlockAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
 539     BlockCompletionFunc *cb, void *opaque)
 540 {
 541     BDRVBlkdebugState *s = bs->opaque;
 542     BlkdebugRule *rule = NULL;
 543
 544     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 545         if (rule->options.inject.sector == -1) {
 546             break;
 547         }
 548     }
 549
 550     if (rule && rule->options.inject.error) {
 551         return inject_error(bs, cb, opaque, rule);
 552     }
 553
 554     return bdrv_aio_flush(bs->file, cb, opaque);
 555 }
 556
 557
 558 static void blkdebug_close(BlockDriverState *bs)
 559 {
 560     BDRVBlkdebugState *s = bs->opaque;
 561     BlkdebugRule *rule, *next;
 562     int i;
 563
 564     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 565         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 566             remove_rule(rule);
 567         }
 568     }
 569 }
 570
 571 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 572 {
 573     BDRVBlkdebugState *s = bs->opaque;
 574     BlkdebugSuspendedReq r;
 575
 576     r = (BlkdebugSuspendedReq) {
 577         .co         = qemu_coroutine_self(),
 578         .tag        = g_strdup(rule->options.suspend.tag),
 579     };
 580
 581     remove_rule(rule);
 582     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 583
 584     printf("blkdebug: Suspended request '%s'\n", r.tag);
 585     qemu_coroutine_yield();
 586     printf("blkdebug: Resuming request '%s'\n", r.tag);
 587
 588     QLIST_REMOVE(&r, next);
 589     g_free(r.tag);
 590 }
 591
 592 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 593     bool injected)
 594 {
 595     BDRVBlkdebugState *s = bs->opaque;
 596
 597     /* Only process rules for the current state */
 598     if (rule->state && rule->state != s->state) {
 599         return injected;
 600     }
 601
 602     /* Take the action */
 603     switch (rule->action) {
 604     case ACTION_INJECT_ERROR:
 605         if (!injected) {
 606             QSIMPLEQ_INIT(&s->active_rules);
 607             injected = true;
 608         }
 609         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 610         break;
 611
 612     case ACTION_SET_STATE:
 613         s->new_state = rule->options.set_state.new_state;
 614         break;
 615
 616     case ACTION_SUSPEND:
 617         suspend_request(bs, rule);
 618         break;
 619     }
 620     return injected;
 621 }
 622
 623 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 624 {
 625     BDRVBlkdebugState *s = bs->opaque;
 626     struct BlkdebugRule *rule, *next;
 627     bool injected;
 628
 629     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 630
 631     injected = false;
 632     s->new_state = s->state;
 633     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 634         injected = process_rule(bs, rule, injected);
 635     }
 636     s->state = s->new_state;
 637 }
 638
 639 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 640                                      const char *tag)
 641 {
 642     BDRVBlkdebugState *s = bs->opaque;
 643     struct BlkdebugRule *rule;
 644     BlkDebugEvent blkdebug_event;
 645
 646     if (get_event_by_name(event, &blkdebug_event) < 0) {
 647         return -ENOENT;
 648     }
 649
 650
 651     rule = g_malloc(sizeof(*rule));
 652     *rule = (struct BlkdebugRule) {
 653         .event  = blkdebug_event,
 654         .action = ACTION_SUSPEND,
 655         .state  = 0,
 656         .options.suspend.tag = g_strdup(tag),
 657     };
 658
 659     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 660
 661     return 0;
 662 }
 663
 664 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 665 {
 666     BDRVBlkdebugState *s = bs->opaque;
 667     BlkdebugSuspendedReq *r, *next;
 668
 669     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 670         if (!strcmp(r->tag, tag)) {
 671             qemu_coroutine_enter(r->co, NULL);
 672             return 0;
 673         }
 674     }
 675     return -ENOENT;
 676 }
 677
 678 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 679                                             const char *tag)
 680 {
 681     BDRVBlkdebugState *s = bs->opaque;
 682     BlkdebugSuspendedReq *r, *r_next;
 683     BlkdebugRule *rule, *next;
 684     int i, ret = -ENOENT;
 685
 686     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 687         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 688             if (rule->action == ACTION_SUSPEND &&
 689                 !strcmp(rule->options.suspend.tag, tag)) {
 690                 remove_rule(rule);
 691                 ret = 0;
 692             }
 693         }
 694     }
 695     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 696         if (!strcmp(r->tag, tag)) {
 697             qemu_coroutine_enter(r->co, NULL);
 698             ret = 0;
 699         }
 700     }
 701     return ret;
 702 }
 703
 704 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 705 {
 706     BDRVBlkdebugState *s = bs->opaque;
 707     BlkdebugSuspendedReq *r;
 708
 709     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 710         if (!strcmp(r->tag, tag)) {
 711             return true;
 712         }
 713     }
 714     return false;
 715 }
 716
 717 static int64_t blkdebug_getlength(BlockDriverState *bs)
 718 {
 719     return bdrv_getlength(bs->file);
 720 }
 721
 722 static void blkdebug_refresh_filename(BlockDriverState *bs)
 723 {
 724     QDict *opts;
 725     const QDictEntry *e;
 726     bool force_json = false;
 727
 728     for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
 729         if (strcmp(qdict_entry_key(e), "config") &&
 730             strcmp(qdict_entry_key(e), "x-image") &&
 731             strcmp(qdict_entry_key(e), "image") &&
 732             strncmp(qdict_entry_key(e), "image.", strlen("image.")))
 733         {
 734             force_json = true;
 735             break;
 736         }
 737     }
 738
 739     if (force_json && !bs->file->full_open_options) {
 740         /* The config file cannot be recreated, so creating a plain filename
 741          * is impossible */
 742         return;
 743     }
 744
 745     if (!force_json && bs->file->exact_filename[0]) {
 746         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 747                  "blkdebug:%s:%s",
 748                  qdict_get_try_str(bs->options, "config") ?: "",
 749                  bs->file->exact_filename);
 750     }
 751
 752     opts = qdict_new();
 753     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("blkdebug")));
 754
 755     QINCREF(bs->file->full_open_options);
 756     qdict_put_obj(opts, "image", QOBJECT(bs->file->full_open_options));
 757
 758     for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
 759         if (strcmp(qdict_entry_key(e), "x-image") &&
 760             strcmp(qdict_entry_key(e), "image") &&
 761             strncmp(qdict_entry_key(e), "image.", strlen("image.")))
 762         {
 763             qobject_incref(qdict_entry_value(e));
 764             qdict_put_obj(opts, qdict_entry_key(e), qdict_entry_value(e));
 765         }
 766     }
 767
 768     bs->full_open_options = opts;
 769 }
 770
 771 static BlockDriver bdrv_blkdebug = {
 772     .format_name            = "blkdebug",
 773     .protocol_name          = "blkdebug",
 774     .instance_size          = sizeof(BDRVBlkdebugState),
 775
 776     .bdrv_parse_filename    = blkdebug_parse_filename,
 777     .bdrv_file_open         = blkdebug_open,
 778     .bdrv_close             = blkdebug_close,
 779     .bdrv_getlength         = blkdebug_getlength,
 780     .bdrv_refresh_filename  = blkdebug_refresh_filename,
 781
 782     .bdrv_aio_readv         = blkdebug_aio_readv,
 783     .bdrv_aio_writev        = blkdebug_aio_writev,
 784     .bdrv_aio_flush         = blkdebug_aio_flush,
 785
 786     .bdrv_debug_event           = blkdebug_debug_event,
 787     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 788     .bdrv_debug_remove_breakpoint
 789                                 = blkdebug_debug_remove_breakpoint,
 790     .bdrv_debug_resume          = blkdebug_debug_resume,
 791     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 792 };
 793
 794 static void bdrv_blkdebug_init(void)
 795 {
 796     bdrv_register(&bdrv_blkdebug);
 797 }
 798
 799 block_init(bdrv_blkdebug_init);