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
 172     [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
 173     [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
 174     [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
 175     [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
 176     [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
 177     [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
 178     [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
 179     [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
 180     [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
 181
 182     [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
 183     [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
 184     [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 185 };
 186
 187 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 188 {
 189     int i;
 190
 191     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 192         if (!strcmp(event_names[i], name)) {
 193             *event = i;
 194             return 0;
 195         }
 196     }
 197
 198     return -1;
 199 }
 200
 201 struct add_rule_data {
 202     BDRVBlkdebugState *s;
 203     int action;
 204 };
 205
 206 static int add_rule(QemuOpts *opts, void *opaque)
 207 {
 208     struct add_rule_data *d = opaque;
 209     BDRVBlkdebugState *s = d->s;
 210     const char* event_name;
 211     BlkDebugEvent event;
 212     struct BlkdebugRule *rule;
 213
 214     /* Find the right event for the rule */
 215     event_name = qemu_opt_get(opts, "event");
 216     if (!event_name || get_event_by_name(event_name, &event) < 0) {
 217         return -1;
 218     }
 219
 220     /* Set attributes common for all actions */
 221     rule = g_malloc0(sizeof(*rule));
 222     *rule = (struct BlkdebugRule) {
 223         .event  = event,
 224         .action = d->action,
 225         .state  = qemu_opt_get_number(opts, "state", 0),
 226     };
 227
 228     /* Parse action-specific options */
 229     switch (d->action) {
 230     case ACTION_INJECT_ERROR:
 231         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 232         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 233         rule->options.inject.immediately =
 234             qemu_opt_get_bool(opts, "immediately", 0);
 235         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 236         break;
 237
 238     case ACTION_SET_STATE:
 239         rule->options.set_state.new_state =
 240             qemu_opt_get_number(opts, "new_state", 0);
 241         break;
 242
 243     case ACTION_SUSPEND:
 244         rule->options.suspend.tag =
 245             g_strdup(qemu_opt_get(opts, "tag"));
 246         break;
 247     };
 248
 249     /* Add the rule */
 250     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 251
 252     return 0;
 253 }
 254
 255 static void remove_rule(BlkdebugRule *rule)
 256 {
 257     switch (rule->action) {
 258     case ACTION_INJECT_ERROR:
 259     case ACTION_SET_STATE:
 260         break;
 261     case ACTION_SUSPEND:
 262         g_free(rule->options.suspend.tag);
 263         break;
 264     }
 265
 266     QLIST_REMOVE(rule, next);
 267     g_free(rule);
 268 }
 269
 270 static int read_config(BDRVBlkdebugState *s, const char *filename)
 271 {
 272     FILE *f;
 273     int ret;
 274     struct add_rule_data d;
 275
 276     /* Allow usage without config file */
 277     if (!*filename) {
 278         return 0;
 279     }
 280
 281     f = fopen(filename, "r");
 282     if (f == NULL) {
 283         return -errno;
 284     }
 285
 286     ret = qemu_config_parse(f, config_groups, filename);
 287     if (ret < 0) {
 288         goto fail;
 289     }
 290
 291     d.s = s;
 292     d.action = ACTION_INJECT_ERROR;
 293     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 294
 295     d.action = ACTION_SET_STATE;
 296     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 297
 298     ret = 0;
 299 fail:
 300     qemu_opts_reset(&inject_error_opts);
 301     qemu_opts_reset(&set_state_opts);
 302     fclose(f);
 303     return ret;
 304 }
 305
 306 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 307 static int blkdebug_open(BlockDriverState *bs, const char *filename,
 308                          QDict *options, int flags)
 309 {
 310     BDRVBlkdebugState *s = bs->opaque;
 311     int ret;
 312     char *config, *c;
 313
 314     /* Parse the blkdebug: prefix */
 315     if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
 316         return -EINVAL;
 317     }
 318     filename += strlen("blkdebug:");
 319
 320     /* Read rules from config file */
 321     c = strchr(filename, ':');
 322     if (c == NULL) {
 323         return -EINVAL;
 324     }
 325
 326     config = g_strdup(filename);
 327     config[c - filename] = '\0';
 328     ret = read_config(s, config);
 329     g_free(config);
 330     if (ret < 0) {
 331         return ret;
 332     }
 333     filename = c + 1;
 334
 335     /* Set initial state */
 336     s->state = 1;
 337
 338     /* Open the backing file */
 339     ret = bdrv_file_open(&bs->file, filename, NULL, flags);
 340     if (ret < 0) {
 341         return ret;
 342     }
 343
 344     return 0;
 345 }
 346
 347 static void error_callback_bh(void *opaque)
 348 {
 349     struct BlkdebugAIOCB *acb = opaque;
 350     qemu_bh_delete(acb->bh);
 351     acb->common.cb(acb->common.opaque, acb->ret);
 352     qemu_aio_release(acb);
 353 }
 354
 355 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 356 {
 357     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 358     qemu_aio_release(acb);
 359 }
 360
 361 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 362     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 363 {
 364     BDRVBlkdebugState *s = bs->opaque;
 365     int error = rule->options.inject.error;
 366     struct BlkdebugAIOCB *acb;
 367     QEMUBH *bh;
 368
 369     if (rule->options.inject.once) {
 370         QSIMPLEQ_INIT(&s->active_rules);
 371     }
 372
 373     if (rule->options.inject.immediately) {
 374         return NULL;
 375     }
 376
 377     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 378     acb->ret = -error;
 379
 380     bh = qemu_bh_new(error_callback_bh, acb);
 381     acb->bh = bh;
 382     qemu_bh_schedule(bh);
 383
 384     return &acb->common;
 385 }
 386
 387 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 388     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 389     BlockDriverCompletionFunc *cb, void *opaque)
 390 {
 391     BDRVBlkdebugState *s = bs->opaque;
 392     BlkdebugRule *rule = NULL;
 393
 394     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 395         if (rule->options.inject.sector == -1 ||
 396             (rule->options.inject.sector >= sector_num &&
 397              rule->options.inject.sector < sector_num + nb_sectors)) {
 398             break;
 399         }
 400     }
 401
 402     if (rule && rule->options.inject.error) {
 403         return inject_error(bs, cb, opaque, rule);
 404     }
 405
 406     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 407 }
 408
 409 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 410     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 411     BlockDriverCompletionFunc *cb, void *opaque)
 412 {
 413     BDRVBlkdebugState *s = bs->opaque;
 414     BlkdebugRule *rule = NULL;
 415
 416     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 417         if (rule->options.inject.sector == -1 ||
 418             (rule->options.inject.sector >= sector_num &&
 419              rule->options.inject.sector < sector_num + nb_sectors)) {
 420             break;
 421         }
 422     }
 423
 424     if (rule && rule->options.inject.error) {
 425         return inject_error(bs, cb, opaque, rule);
 426     }
 427
 428     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 429 }
 430
 431
 432 static void blkdebug_close(BlockDriverState *bs)
 433 {
 434     BDRVBlkdebugState *s = bs->opaque;
 435     BlkdebugRule *rule, *next;
 436     int i;
 437
 438     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 439         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 440             remove_rule(rule);
 441         }
 442     }
 443 }
 444
 445 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 446 {
 447     BDRVBlkdebugState *s = bs->opaque;
 448     BlkdebugSuspendedReq r;
 449
 450     r = (BlkdebugSuspendedReq) {
 451         .co         = qemu_coroutine_self(),
 452         .tag        = g_strdup(rule->options.suspend.tag),
 453     };
 454
 455     remove_rule(rule);
 456     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 457
 458     printf("blkdebug: Suspended request '%s'\n", r.tag);
 459     qemu_coroutine_yield();
 460     printf("blkdebug: Resuming request '%s'\n", r.tag);
 461
 462     QLIST_REMOVE(&r, next);
 463     g_free(r.tag);
 464 }
 465
 466 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 467     bool injected)
 468 {
 469     BDRVBlkdebugState *s = bs->opaque;
 470
 471     /* Only process rules for the current state */
 472     if (rule->state && rule->state != s->state) {
 473         return injected;
 474     }
 475
 476     /* Take the action */
 477     switch (rule->action) {
 478     case ACTION_INJECT_ERROR:
 479         if (!injected) {
 480             QSIMPLEQ_INIT(&s->active_rules);
 481             injected = true;
 482         }
 483         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 484         break;
 485
 486     case ACTION_SET_STATE:
 487         s->new_state = rule->options.set_state.new_state;
 488         break;
 489
 490     case ACTION_SUSPEND:
 491         suspend_request(bs, rule);
 492         break;
 493     }
 494     return injected;
 495 }
 496
 497 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 498 {
 499     BDRVBlkdebugState *s = bs->opaque;
 500     struct BlkdebugRule *rule, *next;
 501     bool injected;
 502
 503     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 504
 505     injected = false;
 506     s->new_state = s->state;
 507     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 508         injected = process_rule(bs, rule, injected);
 509     }
 510     s->state = s->new_state;
 511 }
 512
 513 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 514                                      const char *tag)
 515 {
 516     BDRVBlkdebugState *s = bs->opaque;
 517     struct BlkdebugRule *rule;
 518     BlkDebugEvent blkdebug_event;
 519
 520     if (get_event_by_name(event, &blkdebug_event) < 0) {
 521         return -ENOENT;
 522     }
 523
 524
 525     rule = g_malloc(sizeof(*rule));
 526     *rule = (struct BlkdebugRule) {
 527         .event  = blkdebug_event,
 528         .action = ACTION_SUSPEND,
 529         .state  = 0,
 530         .options.suspend.tag = g_strdup(tag),
 531     };
 532
 533     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 534
 535     return 0;
 536 }
 537
 538 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 539 {
 540     BDRVBlkdebugState *s = bs->opaque;
 541     BlkdebugSuspendedReq *r;
 542
 543     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 544         if (!strcmp(r->tag, tag)) {
 545             qemu_coroutine_enter(r->co, NULL);
 546             return 0;
 547         }
 548     }
 549     return -ENOENT;
 550 }
 551
 552
 553 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 554 {
 555     BDRVBlkdebugState *s = bs->opaque;
 556     BlkdebugSuspendedReq *r;
 557
 558     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 559         if (!strcmp(r->tag, tag)) {
 560             return true;
 561         }
 562     }
 563     return false;
 564 }
 565
 566 static int64_t blkdebug_getlength(BlockDriverState *bs)
 567 {
 568     return bdrv_getlength(bs->file);
 569 }
 570
 571 static BlockDriver bdrv_blkdebug = {
 572     .format_name        = "blkdebug",
 573     .protocol_name      = "blkdebug",
 574
 575     .instance_size      = sizeof(BDRVBlkdebugState),
 576
 577     .bdrv_file_open     = blkdebug_open,
 578     .bdrv_close         = blkdebug_close,
 579     .bdrv_getlength     = blkdebug_getlength,
 580
 581     .bdrv_aio_readv     = blkdebug_aio_readv,
 582     .bdrv_aio_writev    = blkdebug_aio_writev,
 583
 584     .bdrv_debug_event           = blkdebug_debug_event,
 585     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 586     .bdrv_debug_resume          = blkdebug_debug_resume,
 587     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 588 };
 589
 590 static void bdrv_blkdebug_init(void)
 591 {
 592     bdrv_register(&bdrv_blkdebug);
 593 }
 594
 595 block_init(bdrv_blkdebug_init);