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
  30 typedef struct BDRVBlkdebugState {
  31     int state;
  32     int new_state;
  33
  34     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
  35     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  36     QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
  37 } BDRVBlkdebugState;
  38
  39 typedef struct BlkdebugAIOCB {
  40     BlockDriverAIOCB common;
  41     QEMUBH *bh;
  42     int ret;
  43 } BlkdebugAIOCB;
  44
  45 typedef struct BlkdebugSuspendedReq {
  46     Coroutine *co;
  47     char *tag;
  48     QLIST_ENTRY(BlkdebugSuspendedReq) next;
  49 } BlkdebugSuspendedReq;
  50
  51 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
  52
  53 static const AIOCBInfo blkdebug_aiocb_info = {
  54     .aiocb_size = sizeof(BlkdebugAIOCB),
  55     .cancel     = blkdebug_aio_cancel,
  56 };
  57
  58 enum {
  59     ACTION_INJECT_ERROR,
  60     ACTION_SET_STATE,
  61     ACTION_SUSPEND,
  62 };
  63
  64 typedef struct BlkdebugRule {
  65     BlkDebugEvent event;
  66     int action;
  67     int state;
  68     union {
  69         struct {
  70             int error;
  71             int immediately;
  72             int once;
  73             int64_t sector;
  74         } inject;
  75         struct {
  76             int new_state;
  77         } set_state;
  78         struct {
  79             char *tag;
  80         } suspend;
  81     } options;
  82     QLIST_ENTRY(BlkdebugRule) next;
  83     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
  84 } BlkdebugRule;
  85
  86 static QemuOptsList inject_error_opts = {
  87     .name = "inject-error",
  88     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
  89     .desc = {
  90         {
  91             .name = "event",
  92             .type = QEMU_OPT_STRING,
  93         },
  94         {
  95             .name = "state",
  96             .type = QEMU_OPT_NUMBER,
  97         },
  98         {
  99             .name = "errno",
 100             .type = QEMU_OPT_NUMBER,
 101         },
 102         {
 103             .name = "sector",
 104             .type = QEMU_OPT_NUMBER,
 105         },
 106         {
 107             .name = "once",
 108             .type = QEMU_OPT_BOOL,
 109         },
 110         {
 111             .name = "immediately",
 112             .type = QEMU_OPT_BOOL,
 113         },
 114         { /* end of list */ }
 115     },
 116 };
 117
 118 static QemuOptsList set_state_opts = {
 119     .name = "set-state",
 120     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 121     .desc = {
 122         {
 123             .name = "event",
 124             .type = QEMU_OPT_STRING,
 125         },
 126         {
 127             .name = "state",
 128             .type = QEMU_OPT_NUMBER,
 129         },
 130         {
 131             .name = "new_state",
 132             .type = QEMU_OPT_NUMBER,
 133         },
 134         { /* end of list */ }
 135     },
 136 };
 137
 138 static QemuOptsList *config_groups[] = {
 139     &inject_error_opts,
 140     &set_state_opts,
 141     NULL
 142 };
 143
 144 static const char *event_names[BLKDBG_EVENT_MAX] = {
 145     [BLKDBG_L1_UPDATE]                      = "l1_update",
 146     [BLKDBG_L1_GROW_ALLOC_TABLE]            = "l1_grow.alloc_table",
 147     [BLKDBG_L1_GROW_WRITE_TABLE]            = "l1_grow.write_table",
 148     [BLKDBG_L1_GROW_ACTIVATE_TABLE]         = "l1_grow.activate_table",
 149
 150     [BLKDBG_L2_LOAD]                        = "l2_load",
 151     [BLKDBG_L2_UPDATE]                      = "l2_update",
 152     [BLKDBG_L2_UPDATE_COMPRESSED]           = "l2_update_compressed",
 153     [BLKDBG_L2_ALLOC_COW_READ]              = "l2_alloc.cow_read",
 154     [BLKDBG_L2_ALLOC_WRITE]                 = "l2_alloc.write",
 155
 156     [BLKDBG_READ_AIO]                       = "read_aio",
 157     [BLKDBG_READ_BACKING_AIO]               = "read_backing_aio",
 158     [BLKDBG_READ_COMPRESSED]                = "read_compressed",
 159
 160     [BLKDBG_WRITE_AIO]                      = "write_aio",
 161     [BLKDBG_WRITE_COMPRESSED]               = "write_compressed",
 162
 163     [BLKDBG_VMSTATE_LOAD]                   = "vmstate_load",
 164     [BLKDBG_VMSTATE_SAVE]                   = "vmstate_save",
 165
 166     [BLKDBG_COW_READ]                       = "cow_read",
 167     [BLKDBG_COW_WRITE]                      = "cow_write",
 168
 169     [BLKDBG_REFTABLE_LOAD]                  = "reftable_load",
 170     [BLKDBG_REFTABLE_GROW]                  = "reftable_grow",
 171     [BLKDBG_REFTABLE_UPDATE]                = "reftable_update",
 172
 173     [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
 174     [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
 175     [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
 176     [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
 177     [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
 178     [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
 179     [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
 180     [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
 181     [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
 182
 183     [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
 184     [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
 185     [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 186
 187     [BLKDBG_FLUSH_TO_OS]                    = "flush_to_os",
 188     [BLKDBG_FLUSH_TO_DISK]                  = "flush_to_disk",
 189 };
 190
 191 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 192 {
 193     int i;
 194
 195     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 196         if (!strcmp(event_names[i], name)) {
 197             *event = i;
 198             return 0;
 199         }
 200     }
 201
 202     return -1;
 203 }
 204
 205 struct add_rule_data {
 206     BDRVBlkdebugState *s;
 207     int action;
 208 };
 209
 210 static int add_rule(QemuOpts *opts, void *opaque)
 211 {
 212     struct add_rule_data *d = opaque;
 213     BDRVBlkdebugState *s = d->s;
 214     const char* event_name;
 215     BlkDebugEvent event;
 216     struct BlkdebugRule *rule;
 217
 218     /* Find the right event for the rule */
 219     event_name = qemu_opt_get(opts, "event");
 220     if (!event_name || get_event_by_name(event_name, &event) < 0) {
 221         return -1;
 222     }
 223
 224     /* Set attributes common for all actions */
 225     rule = g_malloc0(sizeof(*rule));
 226     *rule = (struct BlkdebugRule) {
 227         .event  = event,
 228         .action = d->action,
 229         .state  = qemu_opt_get_number(opts, "state", 0),
 230     };
 231
 232     /* Parse action-specific options */
 233     switch (d->action) {
 234     case ACTION_INJECT_ERROR:
 235         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 236         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 237         rule->options.inject.immediately =
 238             qemu_opt_get_bool(opts, "immediately", 0);
 239         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 240         break;
 241
 242     case ACTION_SET_STATE:
 243         rule->options.set_state.new_state =
 244             qemu_opt_get_number(opts, "new_state", 0);
 245         break;
 246
 247     case ACTION_SUSPEND:
 248         rule->options.suspend.tag =
 249             g_strdup(qemu_opt_get(opts, "tag"));
 250         break;
 251     };
 252
 253     /* Add the rule */
 254     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 255
 256     return 0;
 257 }
 258
 259 static void remove_rule(BlkdebugRule *rule)
 260 {
 261     switch (rule->action) {
 262     case ACTION_INJECT_ERROR:
 263     case ACTION_SET_STATE:
 264         break;
 265     case ACTION_SUSPEND:
 266         g_free(rule->options.suspend.tag);
 267         break;
 268     }
 269
 270     QLIST_REMOVE(rule, next);
 271     g_free(rule);
 272 }
 273
 274 static int read_config(BDRVBlkdebugState *s, const char *filename,
 275                        QDict *options, Error **errp)
 276 {
 277     FILE *f = NULL;
 278     int ret;
 279     struct add_rule_data d;
 280     Error *local_err = NULL;
 281
 282     if (filename) {
 283         f = fopen(filename, "r");
 284         if (f == NULL) {
 285             error_setg_errno(errp, errno, "Could not read blkdebug config file");
 286             return -errno;
 287         }
 288
 289         ret = qemu_config_parse(f, config_groups, filename);
 290         if (ret < 0) {
 291             error_setg(errp, "Could not parse blkdebug config file");
 292             ret = -EINVAL;
 293             goto fail;
 294         }
 295     }
 296
 297     qemu_config_parse_qdict(options, config_groups, &local_err);
 298     if (error_is_set(&local_err)) {
 299         error_propagate(errp, local_err);
 300         ret = -EINVAL;
 301         goto fail;
 302     }
 303
 304     d.s = s;
 305     d.action = ACTION_INJECT_ERROR;
 306     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 307
 308     d.action = ACTION_SET_STATE;
 309     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 310
 311     ret = 0;
 312 fail:
 313     qemu_opts_reset(&inject_error_opts);
 314     qemu_opts_reset(&set_state_opts);
 315     if (f) {
 316         fclose(f);
 317     }
 318     return ret;
 319 }
 320
 321 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 322 static void blkdebug_parse_filename(const char *filename, QDict *options,
 323                                     Error **errp)
 324 {
 325     const char *c;
 326
 327     /* Parse the blkdebug: prefix */
 328     if (!strstart(filename, "blkdebug:", &filename)) {
 329         /* There was no prefix; therefore, all options have to be already
 330            present in the QDict (except for the filename) */
 331         qdict_put(options, "x-image", qstring_from_str(filename));
 332         return;
 333     }
 334
 335     /* Parse config file path */
 336     c = strchr(filename, ':');
 337     if (c == NULL) {
 338         error_setg(errp, "blkdebug requires both config file and image path");
 339         return;
 340     }
 341
 342     if (c != filename) {
 343         QString *config_path;
 344         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 345         qdict_put(options, "config", config_path);
 346     }
 347
 348     /* TODO Allow multi-level nesting and set file.filename here */
 349     filename = c + 1;
 350     qdict_put(options, "x-image", qstring_from_str(filename));
 351 }
 352
 353 static QemuOptsList runtime_opts = {
 354     .name = "blkdebug",
 355     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 356     .desc = {
 357         {
 358             .name = "config",
 359             .type = QEMU_OPT_STRING,
 360             .help = "Path to the configuration file",
 361         },
 362         {
 363             .name = "x-image",
 364             .type = QEMU_OPT_STRING,
 365             .help = "[internal use only, will be removed]",
 366         },
 367         {
 368             .name = "align",
 369             .type = QEMU_OPT_SIZE,
 370             .help = "Required alignment in bytes",
 371         },
 372         { /* end of list */ }
 373     },
 374 };
 375
 376 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 377                          Error **errp)
 378 {
 379     BDRVBlkdebugState *s = bs->opaque;
 380     QemuOpts *opts;
 381     Error *local_err = NULL;
 382     const char *config;
 383     uint64_t align;
 384     int ret;
 385
 386     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 387     qemu_opts_absorb_qdict(opts, options, &local_err);
 388     if (error_is_set(&local_err)) {
 389         error_propagate(errp, local_err);
 390         ret = -EINVAL;
 391         goto fail;
 392     }
 393
 394     /* Read rules from config file or command line options */
 395     config = qemu_opt_get(opts, "config");
 396     ret = read_config(s, config, options, errp);
 397     if (ret) {
 398         goto fail;
 399     }
 400
 401     /* Set initial state */
 402     s->state = 1;
 403
 404     /* Open the backing file */
 405     ret = bdrv_open_image(&bs->file, qemu_opt_get(opts, "x-image"), options, "image",
 406                           flags, true, false, &local_err);
 407     if (ret < 0) {
 408         error_propagate(errp, local_err);
 409         goto fail;
 410     }
 411
 412     /* Set request alignment */
 413     align = qemu_opt_get_size(opts, "align", bs->request_alignment);
 414     if (align > 0 && align < INT_MAX && !(align & (align - 1))) {
 415         bs->request_alignment = align;
 416     } else {
 417         error_setg(errp, "Invalid alignment");
 418         ret = -EINVAL;
 419         goto fail;
 420     }
 421
 422     ret = 0;
 423 fail:
 424     qemu_opts_del(opts);
 425     return ret;
 426 }
 427
 428 static void error_callback_bh(void *opaque)
 429 {
 430     struct BlkdebugAIOCB *acb = opaque;
 431     qemu_bh_delete(acb->bh);
 432     acb->common.cb(acb->common.opaque, acb->ret);
 433     qemu_aio_release(acb);
 434 }
 435
 436 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 437 {
 438     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 439     qemu_aio_release(acb);
 440 }
 441
 442 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 443     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 444 {
 445     BDRVBlkdebugState *s = bs->opaque;
 446     int error = rule->options.inject.error;
 447     struct BlkdebugAIOCB *acb;
 448     QEMUBH *bh;
 449
 450     if (rule->options.inject.once) {
 451         QSIMPLEQ_INIT(&s->active_rules);
 452     }
 453
 454     if (rule->options.inject.immediately) {
 455         return NULL;
 456     }
 457
 458     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 459     acb->ret = -error;
 460
 461     bh = qemu_bh_new(error_callback_bh, acb);
 462     acb->bh = bh;
 463     qemu_bh_schedule(bh);
 464
 465     return &acb->common;
 466 }
 467
 468 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 469     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 470     BlockDriverCompletionFunc *cb, void *opaque)
 471 {
 472     BDRVBlkdebugState *s = bs->opaque;
 473     BlkdebugRule *rule = NULL;
 474
 475     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 476         if (rule->options.inject.sector == -1 ||
 477             (rule->options.inject.sector >= sector_num &&
 478              rule->options.inject.sector < sector_num + nb_sectors)) {
 479             break;
 480         }
 481     }
 482
 483     if (rule && rule->options.inject.error) {
 484         return inject_error(bs, cb, opaque, rule);
 485     }
 486
 487     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 488 }
 489
 490 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 491     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 492     BlockDriverCompletionFunc *cb, void *opaque)
 493 {
 494     BDRVBlkdebugState *s = bs->opaque;
 495     BlkdebugRule *rule = NULL;
 496
 497     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 498         if (rule->options.inject.sector == -1 ||
 499             (rule->options.inject.sector >= sector_num &&
 500              rule->options.inject.sector < sector_num + nb_sectors)) {
 501             break;
 502         }
 503     }
 504
 505     if (rule && rule->options.inject.error) {
 506         return inject_error(bs, cb, opaque, rule);
 507     }
 508
 509     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 510 }
 511
 512
 513 static void blkdebug_close(BlockDriverState *bs)
 514 {
 515     BDRVBlkdebugState *s = bs->opaque;
 516     BlkdebugRule *rule, *next;
 517     int i;
 518
 519     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 520         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 521             remove_rule(rule);
 522         }
 523     }
 524 }
 525
 526 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 527 {
 528     BDRVBlkdebugState *s = bs->opaque;
 529     BlkdebugSuspendedReq r;
 530
 531     r = (BlkdebugSuspendedReq) {
 532         .co         = qemu_coroutine_self(),
 533         .tag        = g_strdup(rule->options.suspend.tag),
 534     };
 535
 536     remove_rule(rule);
 537     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 538
 539     printf("blkdebug: Suspended request '%s'\n", r.tag);
 540     qemu_coroutine_yield();
 541     printf("blkdebug: Resuming request '%s'\n", r.tag);
 542
 543     QLIST_REMOVE(&r, next);
 544     g_free(r.tag);
 545 }
 546
 547 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 548     bool injected)
 549 {
 550     BDRVBlkdebugState *s = bs->opaque;
 551
 552     /* Only process rules for the current state */
 553     if (rule->state && rule->state != s->state) {
 554         return injected;
 555     }
 556
 557     /* Take the action */
 558     switch (rule->action) {
 559     case ACTION_INJECT_ERROR:
 560         if (!injected) {
 561             QSIMPLEQ_INIT(&s->active_rules);
 562             injected = true;
 563         }
 564         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 565         break;
 566
 567     case ACTION_SET_STATE:
 568         s->new_state = rule->options.set_state.new_state;
 569         break;
 570
 571     case ACTION_SUSPEND:
 572         suspend_request(bs, rule);
 573         break;
 574     }
 575     return injected;
 576 }
 577
 578 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 579 {
 580     BDRVBlkdebugState *s = bs->opaque;
 581     struct BlkdebugRule *rule, *next;
 582     bool injected;
 583
 584     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 585
 586     injected = false;
 587     s->new_state = s->state;
 588     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 589         injected = process_rule(bs, rule, injected);
 590     }
 591     s->state = s->new_state;
 592 }
 593
 594 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 595                                      const char *tag)
 596 {
 597     BDRVBlkdebugState *s = bs->opaque;
 598     struct BlkdebugRule *rule;
 599     BlkDebugEvent blkdebug_event;
 600
 601     if (get_event_by_name(event, &blkdebug_event) < 0) {
 602         return -ENOENT;
 603     }
 604
 605
 606     rule = g_malloc(sizeof(*rule));
 607     *rule = (struct BlkdebugRule) {
 608         .event  = blkdebug_event,
 609         .action = ACTION_SUSPEND,
 610         .state  = 0,
 611         .options.suspend.tag = g_strdup(tag),
 612     };
 613
 614     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 615
 616     return 0;
 617 }
 618
 619 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 620 {
 621     BDRVBlkdebugState *s = bs->opaque;
 622     BlkdebugSuspendedReq *r, *next;
 623
 624     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 625         if (!strcmp(r->tag, tag)) {
 626             qemu_coroutine_enter(r->co, NULL);
 627             return 0;
 628         }
 629     }
 630     return -ENOENT;
 631 }
 632
 633 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 634                                             const char *tag)
 635 {
 636     BDRVBlkdebugState *s = bs->opaque;
 637     BlkdebugSuspendedReq *r, *r_next;
 638     BlkdebugRule *rule, *next;
 639     int i, ret = -ENOENT;
 640
 641     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 642         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 643             if (rule->action == ACTION_SUSPEND &&
 644                 !strcmp(rule->options.suspend.tag, tag)) {
 645                 remove_rule(rule);
 646                 ret = 0;
 647             }
 648         }
 649     }
 650     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 651         if (!strcmp(r->tag, tag)) {
 652             qemu_coroutine_enter(r->co, NULL);
 653             ret = 0;
 654         }
 655     }
 656     return ret;
 657 }
 658
 659 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 660 {
 661     BDRVBlkdebugState *s = bs->opaque;
 662     BlkdebugSuspendedReq *r;
 663
 664     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 665         if (!strcmp(r->tag, tag)) {
 666             return true;
 667         }
 668     }
 669     return false;
 670 }
 671
 672 static int64_t blkdebug_getlength(BlockDriverState *bs)
 673 {
 674     return bdrv_getlength(bs->file);
 675 }
 676
 677 static BlockDriver bdrv_blkdebug = {
 678     .format_name            = "blkdebug",
 679     .protocol_name          = "blkdebug",
 680     .instance_size          = sizeof(BDRVBlkdebugState),
 681
 682     .bdrv_parse_filename    = blkdebug_parse_filename,
 683     .bdrv_file_open         = blkdebug_open,
 684     .bdrv_close             = blkdebug_close,
 685     .bdrv_getlength         = blkdebug_getlength,
 686
 687     .bdrv_aio_readv         = blkdebug_aio_readv,
 688     .bdrv_aio_writev        = blkdebug_aio_writev,
 689
 690     .bdrv_debug_event           = blkdebug_debug_event,
 691     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 692     .bdrv_debug_remove_breakpoint
 693                                 = blkdebug_debug_remove_breakpoint,
 694     .bdrv_debug_resume          = blkdebug_debug_resume,
 695     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 696 };
 697
 698 static void bdrv_blkdebug_init(void)
 699 {
 700     bdrv_register(&bdrv_blkdebug);
 701 }
 702
 703 block_init(bdrv_blkdebug_init);