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 };
 220
 221 static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
 222 {
 223     struct add_rule_data *d = opaque;
 224     BDRVBlkdebugState *s = d->s;
 225     const char* event_name;
 226     BlkDebugEvent event;
 227     struct BlkdebugRule *rule;
 228
 229     /* Find the right event for the rule */
 230     event_name = qemu_opt_get(opts, "event");
 231     if (!event_name) {
 232         error_setg(errp, "Missing event name for rule");
 233         return -1;
 234     } else if (get_event_by_name(event_name, &event) < 0) {
 235         error_setg(errp, "Invalid event name \"%s\"", event_name);
 236         return -1;
 237     }
 238
 239     /* Set attributes common for all actions */
 240     rule = g_malloc0(sizeof(*rule));
 241     *rule = (struct BlkdebugRule) {
 242         .event  = event,
 243         .action = d->action,
 244         .state  = qemu_opt_get_number(opts, "state", 0),
 245     };
 246
 247     /* Parse action-specific options */
 248     switch (d->action) {
 249     case ACTION_INJECT_ERROR:
 250         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 251         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 252         rule->options.inject.immediately =
 253             qemu_opt_get_bool(opts, "immediately", 0);
 254         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 255         break;
 256
 257     case ACTION_SET_STATE:
 258         rule->options.set_state.new_state =
 259             qemu_opt_get_number(opts, "new_state", 0);
 260         break;
 261
 262     case ACTION_SUSPEND:
 263         rule->options.suspend.tag =
 264             g_strdup(qemu_opt_get(opts, "tag"));
 265         break;
 266     };
 267
 268     /* Add the rule */
 269     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 270
 271     return 0;
 272 }
 273
 274 static void remove_rule(BlkdebugRule *rule)
 275 {
 276     switch (rule->action) {
 277     case ACTION_INJECT_ERROR:
 278     case ACTION_SET_STATE:
 279         break;
 280     case ACTION_SUSPEND:
 281         g_free(rule->options.suspend.tag);
 282         break;
 283     }
 284
 285     QLIST_REMOVE(rule, next);
 286     g_free(rule);
 287 }
 288
 289 static int read_config(BDRVBlkdebugState *s, const char *filename,
 290                        QDict *options, Error **errp)
 291 {
 292     FILE *f = NULL;
 293     int ret;
 294     struct add_rule_data d;
 295     Error *local_err = NULL;
 296
 297     if (filename) {
 298         f = fopen(filename, "r");
 299         if (f == NULL) {
 300             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 301             return -errno;
 302         }
 303
 304         ret = qemu_config_parse(f, config_groups, filename);
 305         if (ret < 0) {
 306             error_setg(errp, "Could not parse blkdebug config file");
 307             ret = -EINVAL;
 308             goto fail;
 309         }
 310     }
 311
 312     qemu_config_parse_qdict(options, config_groups, &local_err);
 313     if (local_err) {
 314         error_propagate(errp, local_err);
 315         ret = -EINVAL;
 316         goto fail;
 317     }
 318
 319     d.s = s;
 320     d.action = ACTION_INJECT_ERROR;
 321     qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
 322     if (local_err) {
 323         error_propagate(errp, local_err);
 324         ret = -EINVAL;
 325         goto fail;
 326     }
 327
 328     d.action = ACTION_SET_STATE;
 329     qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
 330     if (local_err) {
 331         error_propagate(errp, local_err);
 332         ret = -EINVAL;
 333         goto fail;
 334     }
 335
 336     ret = 0;
 337 fail:
 338     qemu_opts_reset(&inject_error_opts);
 339     qemu_opts_reset(&set_state_opts);
 340     if (f) {
 341         fclose(f);
 342     }
 343     return ret;
 344 }
 345
 346 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 347 static void blkdebug_parse_filename(const char *filename, QDict *options,
 348                                     Error **errp)
 349 {
 350     const char *c;
 351
 352     /* Parse the blkdebug: prefix */
 353     if (!strstart(filename, "blkdebug:", &filename)) {
 354         /* There was no prefix; therefore, all options have to be already
 355            present in the QDict (except for the filename) */
 356         qdict_put(options, "x-image", qstring_from_str(filename));
 357         return;
 358     }
 359
 360     /* Parse config file path */
 361     c = strchr(filename, ':');
 362     if (c == NULL) {
 363         error_setg(errp, "blkdebug requires both config file and image path");
 364         return;
 365     }
 366
 367     if (c != filename) {
 368         QString *config_path;
 369         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 370         qdict_put(options, "config", config_path);
 371     }
 372
 373     /* TODO Allow multi-level nesting and set file.filename here */
 374     filename = c + 1;
 375     qdict_put(options, "x-image", qstring_from_str(filename));
 376 }
 377
 378 static QemuOptsList runtime_opts = {
 379     .name = "blkdebug",
 380     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 381     .desc = {
 382         {
 383             .name = "config",
 384             .type = QEMU_OPT_STRING,
 385             .help = "Path to the configuration file",
 386         },
 387         {
 388             .name = "x-image",
 389             .type = QEMU_OPT_STRING,
 390             .help = "[internal use only, will be removed]",
 391         },
 392         {
 393             .name = "align",
 394             .type = QEMU_OPT_SIZE,
 395             .help = "Required alignment in bytes",
 396         },
 397         { /* end of list */ }
 398     },
 399 };
 400
 401 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 402                          Error **errp)
 403 {
 404     BDRVBlkdebugState *s = bs->opaque;
 405     QemuOpts *opts;
 406     Error *local_err = NULL;
 407     const char *config;
 408     uint64_t align;
 409     int ret;
 410
 411     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 412     qemu_opts_absorb_qdict(opts, options, &local_err);
 413     if (local_err) {
 414         error_propagate(errp, local_err);
 415         ret = -EINVAL;
 416         goto out;
 417     }
 418
 419     /* Read rules from config file or command line options */
 420     config = qemu_opt_get(opts, "config");
 421     ret = read_config(s, config, options, errp);
 422     if (ret) {
 423         goto out;
 424     }
 425
 426     /* Set initial state */
 427     s->state = 1;
 428
 429     /* Open the image file */
 430     bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image",
 431                                bs, &child_file, false, &local_err);
 432     if (local_err) {
 433         ret = -EINVAL;
 434         error_propagate(errp, local_err);
 435         goto out;
 436     }
 437
 438     /* Set request alignment */
 439     align = qemu_opt_get_size(opts, "align", bs->request_alignment);
 440     if (align > 0 && align < INT_MAX && !(align & (align - 1))) {
 441         bs->request_alignment = align;
 442     } else {
 443         error_setg(errp, "Invalid alignment");
 444         ret = -EINVAL;
 445         goto fail_unref;
 446     }
 447
 448     ret = 0;
 449     goto out;
 450
 451 fail_unref:
 452     bdrv_unref_child(bs, bs->file);
 453 out:
 454     qemu_opts_del(opts);
 455     return ret;
 456 }
 457
 458 static void error_callback_bh(void *opaque)
 459 {
 460     struct BlkdebugAIOCB *acb = opaque;
 461     qemu_bh_delete(acb->bh);
 462     acb->common.cb(acb->common.opaque, acb->ret);
 463     qemu_aio_unref(acb);
 464 }
 465
 466 static BlockAIOCB *inject_error(BlockDriverState *bs,
 467     BlockCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 468 {
 469     BDRVBlkdebugState *s = bs->opaque;
 470     int error = rule->options.inject.error;
 471     struct BlkdebugAIOCB *acb;
 472     QEMUBH *bh;
 473     bool immediately = rule->options.inject.immediately;
 474
 475     if (rule->options.inject.once) {
 476         QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
 477         remove_rule(rule);
 478     }
 479
 480     if (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->bs, sector_num, qiov, nb_sectors,
 514                           cb, opaque);
 515 }
 516
 517 static BlockAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 518     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 519     BlockCompletionFunc *cb, void *opaque)
 520 {
 521     BDRVBlkdebugState *s = bs->opaque;
 522     BlkdebugRule *rule = NULL;
 523
 524     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 525         if (rule->options.inject.sector == -1 ||
 526             (rule->options.inject.sector >= sector_num &&
 527              rule->options.inject.sector < sector_num + nb_sectors)) {
 528             break;
 529         }
 530     }
 531
 532     if (rule && rule->options.inject.error) {
 533         return inject_error(bs, cb, opaque, rule);
 534     }
 535
 536     return bdrv_aio_writev(bs->file->bs, sector_num, qiov, nb_sectors,
 537                            cb, opaque);
 538 }
 539
 540 static BlockAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
 541     BlockCompletionFunc *cb, void *opaque)
 542 {
 543     BDRVBlkdebugState *s = bs->opaque;
 544     BlkdebugRule *rule = NULL;
 545
 546     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 547         if (rule->options.inject.sector == -1) {
 548             break;
 549         }
 550     }
 551
 552     if (rule && rule->options.inject.error) {
 553         return inject_error(bs, cb, opaque, rule);
 554     }
 555
 556     return bdrv_aio_flush(bs->file->bs, cb, opaque);
 557 }
 558
 559
 560 static void blkdebug_close(BlockDriverState *bs)
 561 {
 562     BDRVBlkdebugState *s = bs->opaque;
 563     BlkdebugRule *rule, *next;
 564     int i;
 565
 566     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 567         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 568             remove_rule(rule);
 569         }
 570     }
 571 }
 572
 573 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 574 {
 575     BDRVBlkdebugState *s = bs->opaque;
 576     BlkdebugSuspendedReq r;
 577
 578     r = (BlkdebugSuspendedReq) {
 579         .co         = qemu_coroutine_self(),
 580         .tag        = g_strdup(rule->options.suspend.tag),
 581     };
 582
 583     remove_rule(rule);
 584     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 585
 586     printf("blkdebug: Suspended request '%s'\n", r.tag);
 587     qemu_coroutine_yield();
 588     printf("blkdebug: Resuming request '%s'\n", r.tag);
 589
 590     QLIST_REMOVE(&r, next);
 591     g_free(r.tag);
 592 }
 593
 594 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 595     bool injected)
 596 {
 597     BDRVBlkdebugState *s = bs->opaque;
 598
 599     /* Only process rules for the current state */
 600     if (rule->state && rule->state != s->state) {
 601         return injected;
 602     }
 603
 604     /* Take the action */
 605     switch (rule->action) {
 606     case ACTION_INJECT_ERROR:
 607         if (!injected) {
 608             QSIMPLEQ_INIT(&s->active_rules);
 609             injected = true;
 610         }
 611         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 612         break;
 613
 614     case ACTION_SET_STATE:
 615         s->new_state = rule->options.set_state.new_state;
 616         break;
 617
 618     case ACTION_SUSPEND:
 619         suspend_request(bs, rule);
 620         break;
 621     }
 622     return injected;
 623 }
 624
 625 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 626 {
 627     BDRVBlkdebugState *s = bs->opaque;
 628     struct BlkdebugRule *rule, *next;
 629     bool injected;
 630
 631     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 632
 633     injected = false;
 634     s->new_state = s->state;
 635     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 636         injected = process_rule(bs, rule, injected);
 637     }
 638     s->state = s->new_state;
 639 }
 640
 641 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 642                                      const char *tag)
 643 {
 644     BDRVBlkdebugState *s = bs->opaque;
 645     struct BlkdebugRule *rule;
 646     BlkDebugEvent blkdebug_event;
 647
 648     if (get_event_by_name(event, &blkdebug_event) < 0) {
 649         return -ENOENT;
 650     }
 651
 652
 653     rule = g_malloc(sizeof(*rule));
 654     *rule = (struct BlkdebugRule) {
 655         .event  = blkdebug_event,
 656         .action = ACTION_SUSPEND,
 657         .state  = 0,
 658         .options.suspend.tag = g_strdup(tag),
 659     };
 660
 661     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 662
 663     return 0;
 664 }
 665
 666 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 667 {
 668     BDRVBlkdebugState *s = bs->opaque;
 669     BlkdebugSuspendedReq *r, *next;
 670
 671     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 672         if (!strcmp(r->tag, tag)) {
 673             qemu_coroutine_enter(r->co, NULL);
 674             return 0;
 675         }
 676     }
 677     return -ENOENT;
 678 }
 679
 680 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 681                                             const char *tag)
 682 {
 683     BDRVBlkdebugState *s = bs->opaque;
 684     BlkdebugSuspendedReq *r, *r_next;
 685     BlkdebugRule *rule, *next;
 686     int i, ret = -ENOENT;
 687
 688     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 689         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 690             if (rule->action == ACTION_SUSPEND &&
 691                 !strcmp(rule->options.suspend.tag, tag)) {
 692                 remove_rule(rule);
 693                 ret = 0;
 694             }
 695         }
 696     }
 697     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 698         if (!strcmp(r->tag, tag)) {
 699             qemu_coroutine_enter(r->co, NULL);
 700             ret = 0;
 701         }
 702     }
 703     return ret;
 704 }
 705
 706 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 707 {
 708     BDRVBlkdebugState *s = bs->opaque;
 709     BlkdebugSuspendedReq *r;
 710
 711     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 712         if (!strcmp(r->tag, tag)) {
 713             return true;
 714         }
 715     }
 716     return false;
 717 }
 718
 719 static int64_t blkdebug_getlength(BlockDriverState *bs)
 720 {
 721     return bdrv_getlength(bs->file->bs);
 722 }
 723
 724 static int blkdebug_truncate(BlockDriverState *bs, int64_t offset)
 725 {
 726     return bdrv_truncate(bs->file->bs, offset);
 727 }
 728
 729 static void blkdebug_refresh_filename(BlockDriverState *bs)
 730 {
 731     QDict *opts;
 732     const QDictEntry *e;
 733     bool force_json = false;
 734
 735     for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
 736         if (strcmp(qdict_entry_key(e), "config") &&
 737             strcmp(qdict_entry_key(e), "x-image") &&
 738             strcmp(qdict_entry_key(e), "image") &&
 739             strncmp(qdict_entry_key(e), "image.", strlen("image.")))
 740         {
 741             force_json = true;
 742             break;
 743         }
 744     }
 745
 746     if (force_json && !bs->file->bs->full_open_options) {
 747         /* The config file cannot be recreated, so creating a plain filename
 748          * is impossible */
 749         return;
 750     }
 751
 752     if (!force_json && bs->file->bs->exact_filename[0]) {
 753         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 754                  "blkdebug:%s:%s",
 755                  qdict_get_try_str(bs->options, "config") ?: "",
 756                  bs->file->bs->exact_filename);
 757     }
 758
 759     opts = qdict_new();
 760     qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("blkdebug")));
 761
 762     QINCREF(bs->file->bs->full_open_options);
 763     qdict_put_obj(opts, "image", QOBJECT(bs->file->bs->full_open_options));
 764
 765     for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
 766         if (strcmp(qdict_entry_key(e), "x-image") &&
 767             strcmp(qdict_entry_key(e), "image") &&
 768             strncmp(qdict_entry_key(e), "image.", strlen("image.")))
 769         {
 770             qobject_incref(qdict_entry_value(e));
 771             qdict_put_obj(opts, qdict_entry_key(e), qdict_entry_value(e));
 772         }
 773     }
 774
 775     bs->full_open_options = opts;
 776 }
 777
 778 static BlockDriver bdrv_blkdebug = {
 779     .format_name            = "blkdebug",
 780     .protocol_name          = "blkdebug",
 781     .instance_size          = sizeof(BDRVBlkdebugState),
 782
 783     .bdrv_parse_filename    = blkdebug_parse_filename,
 784     .bdrv_file_open         = blkdebug_open,
 785     .bdrv_close             = blkdebug_close,
 786     .bdrv_getlength         = blkdebug_getlength,
 787     .bdrv_truncate          = blkdebug_truncate,
 788     .bdrv_refresh_filename  = blkdebug_refresh_filename,
 789
 790     .bdrv_aio_readv         = blkdebug_aio_readv,
 791     .bdrv_aio_writev        = blkdebug_aio_writev,
 792     .bdrv_aio_flush         = blkdebug_aio_flush,
 793
 794     .bdrv_debug_event           = blkdebug_debug_event,
 795     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 796     .bdrv_debug_remove_breakpoint
 797                                 = blkdebug_debug_remove_breakpoint,
 798     .bdrv_debug_resume          = blkdebug_debug_resume,
 799     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 800 };
 801
 802 static void bdrv_blkdebug_init(void)
 803 {
 804     bdrv_register(&bdrv_blkdebug);
 805 }
 806
 807 block_init(bdrv_blkdebug_init);