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 {
 276     FILE *f;
 277     int ret;
 278     struct add_rule_data d;
 279
 280     f = fopen(filename, "r");
 281     if (f == NULL) {
 282         return -errno;
 283     }
 284
 285     ret = qemu_config_parse(f, config_groups, filename);
 286     if (ret < 0) {
 287         goto fail;
 288     }
 289
 290     d.s = s;
 291     d.action = ACTION_INJECT_ERROR;
 292     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 293
 294     d.action = ACTION_SET_STATE;
 295     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 296
 297     ret = 0;
 298 fail:
 299     qemu_opts_reset(&inject_error_opts);
 300     qemu_opts_reset(&set_state_opts);
 301     fclose(f);
 302     return ret;
 303 }
 304
 305 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 306 static void blkdebug_parse_filename(const char *filename, QDict *options,
 307                                     Error **errp)
 308 {
 309     const char *c;
 310
 311     /* Parse the blkdebug: prefix */
 312     if (!strstart(filename, "blkdebug:", &filename)) {
 313         error_setg(errp, "File name string must start with 'blkdebug:'");
 314         return;
 315     }
 316
 317     /* Parse config file path */
 318     c = strchr(filename, ':');
 319     if (c == NULL) {
 320         error_setg(errp, "blkdebug requires both config file and image path");
 321         return;
 322     }
 323
 324     if (c != filename) {
 325         QString *config_path;
 326         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 327         qdict_put(options, "config", config_path);
 328     }
 329
 330     /* TODO Allow multi-level nesting and set file.filename here */
 331     filename = c + 1;
 332     qdict_put(options, "x-image", qstring_from_str(filename));
 333 }
 334
 335 static QemuOptsList runtime_opts = {
 336     .name = "blkdebug",
 337     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 338     .desc = {
 339         {
 340             .name = "config",
 341             .type = QEMU_OPT_STRING,
 342             .help = "Path to the configuration file",
 343         },
 344         {
 345             .name = "x-image",
 346             .type = QEMU_OPT_STRING,
 347             .help = "[internal use only, will be removed]",
 348         },
 349         { /* end of list */ }
 350     },
 351 };
 352
 353 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 354                          Error **errp)
 355 {
 356     BDRVBlkdebugState *s = bs->opaque;
 357     QemuOpts *opts;
 358     Error *local_err = NULL;
 359     const char *filename, *config;
 360     int ret;
 361
 362     opts = qemu_opts_create_nofail(&runtime_opts);
 363     qemu_opts_absorb_qdict(opts, options, &local_err);
 364     if (error_is_set(&local_err)) {
 365         error_propagate(errp, local_err);
 366         ret = -EINVAL;
 367         goto fail;
 368     }
 369
 370     /* Read rules from config file */
 371     config = qemu_opt_get(opts, "config");
 372     if (config) {
 373         ret = read_config(s, config);
 374         if (ret < 0) {
 375             error_setg_errno(errp, -ret, "Could not read blkdebug config file");
 376             goto fail;
 377         }
 378     }
 379
 380     /* Set initial state */
 381     s->state = 1;
 382
 383     /* Open the backing file */
 384     filename = qemu_opt_get(opts, "x-image");
 385     if (filename == NULL) {
 386         error_setg(errp, "Could not retrieve image file name");
 387         ret = -EINVAL;
 388         goto fail;
 389     }
 390
 391     ret = bdrv_file_open(&bs->file, filename, NULL, flags, &local_err);
 392     if (ret < 0) {
 393         error_propagate(errp, local_err);
 394         goto fail;
 395     }
 396
 397     ret = 0;
 398 fail:
 399     qemu_opts_del(opts);
 400     return ret;
 401 }
 402
 403 static void error_callback_bh(void *opaque)
 404 {
 405     struct BlkdebugAIOCB *acb = opaque;
 406     qemu_bh_delete(acb->bh);
 407     acb->common.cb(acb->common.opaque, acb->ret);
 408     qemu_aio_release(acb);
 409 }
 410
 411 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 412 {
 413     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 414     qemu_aio_release(acb);
 415 }
 416
 417 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 418     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 419 {
 420     BDRVBlkdebugState *s = bs->opaque;
 421     int error = rule->options.inject.error;
 422     struct BlkdebugAIOCB *acb;
 423     QEMUBH *bh;
 424
 425     if (rule->options.inject.once) {
 426         QSIMPLEQ_INIT(&s->active_rules);
 427     }
 428
 429     if (rule->options.inject.immediately) {
 430         return NULL;
 431     }
 432
 433     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 434     acb->ret = -error;
 435
 436     bh = qemu_bh_new(error_callback_bh, acb);
 437     acb->bh = bh;
 438     qemu_bh_schedule(bh);
 439
 440     return &acb->common;
 441 }
 442
 443 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 444     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 445     BlockDriverCompletionFunc *cb, void *opaque)
 446 {
 447     BDRVBlkdebugState *s = bs->opaque;
 448     BlkdebugRule *rule = NULL;
 449
 450     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 451         if (rule->options.inject.sector == -1 ||
 452             (rule->options.inject.sector >= sector_num &&
 453              rule->options.inject.sector < sector_num + nb_sectors)) {
 454             break;
 455         }
 456     }
 457
 458     if (rule && rule->options.inject.error) {
 459         return inject_error(bs, cb, opaque, rule);
 460     }
 461
 462     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 463 }
 464
 465 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 466     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 467     BlockDriverCompletionFunc *cb, void *opaque)
 468 {
 469     BDRVBlkdebugState *s = bs->opaque;
 470     BlkdebugRule *rule = NULL;
 471
 472     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 473         if (rule->options.inject.sector == -1 ||
 474             (rule->options.inject.sector >= sector_num &&
 475              rule->options.inject.sector < sector_num + nb_sectors)) {
 476             break;
 477         }
 478     }
 479
 480     if (rule && rule->options.inject.error) {
 481         return inject_error(bs, cb, opaque, rule);
 482     }
 483
 484     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 485 }
 486
 487
 488 static void blkdebug_close(BlockDriverState *bs)
 489 {
 490     BDRVBlkdebugState *s = bs->opaque;
 491     BlkdebugRule *rule, *next;
 492     int i;
 493
 494     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 495         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 496             remove_rule(rule);
 497         }
 498     }
 499 }
 500
 501 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 502 {
 503     BDRVBlkdebugState *s = bs->opaque;
 504     BlkdebugSuspendedReq r;
 505
 506     r = (BlkdebugSuspendedReq) {
 507         .co         = qemu_coroutine_self(),
 508         .tag        = g_strdup(rule->options.suspend.tag),
 509     };
 510
 511     remove_rule(rule);
 512     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 513
 514     printf("blkdebug: Suspended request '%s'\n", r.tag);
 515     qemu_coroutine_yield();
 516     printf("blkdebug: Resuming request '%s'\n", r.tag);
 517
 518     QLIST_REMOVE(&r, next);
 519     g_free(r.tag);
 520 }
 521
 522 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 523     bool injected)
 524 {
 525     BDRVBlkdebugState *s = bs->opaque;
 526
 527     /* Only process rules for the current state */
 528     if (rule->state && rule->state != s->state) {
 529         return injected;
 530     }
 531
 532     /* Take the action */
 533     switch (rule->action) {
 534     case ACTION_INJECT_ERROR:
 535         if (!injected) {
 536             QSIMPLEQ_INIT(&s->active_rules);
 537             injected = true;
 538         }
 539         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 540         break;
 541
 542     case ACTION_SET_STATE:
 543         s->new_state = rule->options.set_state.new_state;
 544         break;
 545
 546     case ACTION_SUSPEND:
 547         suspend_request(bs, rule);
 548         break;
 549     }
 550     return injected;
 551 }
 552
 553 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 554 {
 555     BDRVBlkdebugState *s = bs->opaque;
 556     struct BlkdebugRule *rule, *next;
 557     bool injected;
 558
 559     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 560
 561     injected = false;
 562     s->new_state = s->state;
 563     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 564         injected = process_rule(bs, rule, injected);
 565     }
 566     s->state = s->new_state;
 567 }
 568
 569 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 570                                      const char *tag)
 571 {
 572     BDRVBlkdebugState *s = bs->opaque;
 573     struct BlkdebugRule *rule;
 574     BlkDebugEvent blkdebug_event;
 575
 576     if (get_event_by_name(event, &blkdebug_event) < 0) {
 577         return -ENOENT;
 578     }
 579
 580
 581     rule = g_malloc(sizeof(*rule));
 582     *rule = (struct BlkdebugRule) {
 583         .event  = blkdebug_event,
 584         .action = ACTION_SUSPEND,
 585         .state  = 0,
 586         .options.suspend.tag = g_strdup(tag),
 587     };
 588
 589     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 590
 591     return 0;
 592 }
 593
 594 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 595 {
 596     BDRVBlkdebugState *s = bs->opaque;
 597     BlkdebugSuspendedReq *r, *next;
 598
 599     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) {
 600         if (!strcmp(r->tag, tag)) {
 601             qemu_coroutine_enter(r->co, NULL);
 602             return 0;
 603         }
 604     }
 605     return -ENOENT;
 606 }
 607
 608 static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
 609                                             const char *tag)
 610 {
 611     BDRVBlkdebugState *s = bs->opaque;
 612     BlkdebugSuspendedReq *r, *r_next;
 613     BlkdebugRule *rule, *next;
 614     int i, ret = -ENOENT;
 615
 616     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 617         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 618             if (rule->action == ACTION_SUSPEND &&
 619                 !strcmp(rule->options.suspend.tag, tag)) {
 620                 remove_rule(rule);
 621                 ret = 0;
 622             }
 623         }
 624     }
 625     QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) {
 626         if (!strcmp(r->tag, tag)) {
 627             qemu_coroutine_enter(r->co, NULL);
 628             ret = 0;
 629         }
 630     }
 631     return ret;
 632 }
 633
 634 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 635 {
 636     BDRVBlkdebugState *s = bs->opaque;
 637     BlkdebugSuspendedReq *r;
 638
 639     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 640         if (!strcmp(r->tag, tag)) {
 641             return true;
 642         }
 643     }
 644     return false;
 645 }
 646
 647 static int64_t blkdebug_getlength(BlockDriverState *bs)
 648 {
 649     return bdrv_getlength(bs->file);
 650 }
 651
 652 static BlockDriver bdrv_blkdebug = {
 653     .format_name            = "blkdebug",
 654     .protocol_name          = "blkdebug",
 655     .instance_size          = sizeof(BDRVBlkdebugState),
 656
 657     .bdrv_parse_filename    = blkdebug_parse_filename,
 658     .bdrv_file_open         = blkdebug_open,
 659     .bdrv_close             = blkdebug_close,
 660     .bdrv_getlength         = blkdebug_getlength,
 661
 662     .bdrv_aio_readv         = blkdebug_aio_readv,
 663     .bdrv_aio_writev        = blkdebug_aio_writev,
 664
 665     .bdrv_debug_event           = blkdebug_debug_event,
 666     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 667     .bdrv_debug_remove_breakpoint
 668                                 = blkdebug_debug_remove_breakpoint,
 669     .bdrv_debug_resume          = blkdebug_debug_resume,
 670     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 671 };
 672
 673 static void bdrv_blkdebug_init(void)
 674 {
 675     bdrv_register(&bdrv_blkdebug);
 676 }
 677
 678 block_init(bdrv_blkdebug_init);