block/blkdebug.c

   1 /*
   2  * Block protocol for I/O error injection
   3  *
   4  * Copyright (c) 2010 Kevin Wolf <[email protected]>
   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, int flags)
 308 {
 309     BDRVBlkdebugState *s = bs->opaque;
 310     int ret;
 311     char *config, *c;
 312
 313     /* Parse the blkdebug: prefix */
 314     if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
 315         return -EINVAL;
 316     }
 317     filename += strlen("blkdebug:");
 318
 319     /* Read rules from config file */
 320     c = strchr(filename, ':');
 321     if (c == NULL) {
 322         return -EINVAL;
 323     }
 324
 325     config = g_strdup(filename);
 326     config[c - filename] = '\0';
 327     ret = read_config(s, config);
 328     g_free(config);
 329     if (ret < 0) {
 330         return ret;
 331     }
 332     filename = c + 1;
 333
 334     /* Set initial state */
 335     s->state = 1;
 336
 337     /* Open the backing file */
 338     ret = bdrv_file_open(&bs->file, filename, flags);
 339     if (ret < 0) {
 340         return ret;
 341     }
 342
 343     return 0;
 344 }
 345
 346 static void error_callback_bh(void *opaque)
 347 {
 348     struct BlkdebugAIOCB *acb = opaque;
 349     qemu_bh_delete(acb->bh);
 350     acb->common.cb(acb->common.opaque, acb->ret);
 351     qemu_aio_release(acb);
 352 }
 353
 354 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 355 {
 356     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 357     qemu_aio_release(acb);
 358 }
 359
 360 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 361     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 362 {
 363     BDRVBlkdebugState *s = bs->opaque;
 364     int error = rule->options.inject.error;
 365     struct BlkdebugAIOCB *acb;
 366     QEMUBH *bh;
 367
 368     if (rule->options.inject.once) {
 369         QSIMPLEQ_INIT(&s->active_rules);
 370     }
 371
 372     if (rule->options.inject.immediately) {
 373         return NULL;
 374     }
 375
 376     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 377     acb->ret = -error;
 378
 379     bh = qemu_bh_new(error_callback_bh, acb);
 380     acb->bh = bh;
 381     qemu_bh_schedule(bh);
 382
 383     return &acb->common;
 384 }
 385
 386 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 387     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 388     BlockDriverCompletionFunc *cb, void *opaque)
 389 {
 390     BDRVBlkdebugState *s = bs->opaque;
 391     BlkdebugRule *rule = NULL;
 392
 393     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 394         if (rule->options.inject.sector == -1 ||
 395             (rule->options.inject.sector >= sector_num &&
 396              rule->options.inject.sector < sector_num + nb_sectors)) {
 397             break;
 398         }
 399     }
 400
 401     if (rule && rule->options.inject.error) {
 402         return inject_error(bs, cb, opaque, rule);
 403     }
 404
 405     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 406 }
 407
 408 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 409     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 410     BlockDriverCompletionFunc *cb, void *opaque)
 411 {
 412     BDRVBlkdebugState *s = bs->opaque;
 413     BlkdebugRule *rule = NULL;
 414
 415     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 416         if (rule->options.inject.sector == -1 ||
 417             (rule->options.inject.sector >= sector_num &&
 418              rule->options.inject.sector < sector_num + nb_sectors)) {
 419             break;
 420         }
 421     }
 422
 423     if (rule && rule->options.inject.error) {
 424         return inject_error(bs, cb, opaque, rule);
 425     }
 426
 427     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 428 }
 429
 430
 431 static void blkdebug_close(BlockDriverState *bs)
 432 {
 433     BDRVBlkdebugState *s = bs->opaque;
 434     BlkdebugRule *rule, *next;
 435     int i;
 436
 437     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 438         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 439             remove_rule(rule);
 440         }
 441     }
 442 }
 443
 444 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 445 {
 446     BDRVBlkdebugState *s = bs->opaque;
 447     BlkdebugSuspendedReq r;
 448
 449     r = (BlkdebugSuspendedReq) {
 450         .co         = qemu_coroutine_self(),
 451         .tag        = g_strdup(rule->options.suspend.tag),
 452     };
 453
 454     remove_rule(rule);
 455     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 456
 457     printf("blkdebug: Suspended request '%s'\n", r.tag);
 458     qemu_coroutine_yield();
 459     printf("blkdebug: Resuming request '%s'\n", r.tag);
 460
 461     QLIST_REMOVE(&r, next);
 462     g_free(r.tag);
 463 }
 464
 465 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 466     bool injected)
 467 {
 468     BDRVBlkdebugState *s = bs->opaque;
 469
 470     /* Only process rules for the current state */
 471     if (rule->state && rule->state != s->state) {
 472         return injected;
 473     }
 474
 475     /* Take the action */
 476     switch (rule->action) {
 477     case ACTION_INJECT_ERROR:
 478         if (!injected) {
 479             QSIMPLEQ_INIT(&s->active_rules);
 480             injected = true;
 481         }
 482         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 483         break;
 484
 485     case ACTION_SET_STATE:
 486         s->new_state = rule->options.set_state.new_state;
 487         break;
 488
 489     case ACTION_SUSPEND:
 490         suspend_request(bs, rule);
 491         break;
 492     }
 493     return injected;
 494 }
 495
 496 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 497 {
 498     BDRVBlkdebugState *s = bs->opaque;
 499     struct BlkdebugRule *rule, *next;
 500     bool injected;
 501
 502     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 503
 504     injected = false;
 505     s->new_state = s->state;
 506     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 507         injected = process_rule(bs, rule, injected);
 508     }
 509     s->state = s->new_state;
 510 }
 511
 512 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 513                                      const char *tag)
 514 {
 515     BDRVBlkdebugState *s = bs->opaque;
 516     struct BlkdebugRule *rule;
 517     BlkDebugEvent blkdebug_event;
 518
 519     if (get_event_by_name(event, &blkdebug_event) < 0) {
 520         return -ENOENT;
 521     }
 522
 523
 524     rule = g_malloc(sizeof(*rule));
 525     *rule = (struct BlkdebugRule) {
 526         .event  = blkdebug_event,
 527         .action = ACTION_SUSPEND,
 528         .state  = 0,
 529         .options.suspend.tag = g_strdup(tag),
 530     };
 531
 532     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 533
 534     return 0;
 535 }
 536
 537 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 538 {
 539     BDRVBlkdebugState *s = bs->opaque;
 540     BlkdebugSuspendedReq *r;
 541
 542     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 543         if (!strcmp(r->tag, tag)) {
 544             qemu_coroutine_enter(r->co, NULL);
 545             return 0;
 546         }
 547     }
 548     return -ENOENT;
 549 }
 550
 551
 552 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 553 {
 554     BDRVBlkdebugState *s = bs->opaque;
 555     BlkdebugSuspendedReq *r;
 556
 557     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 558         if (!strcmp(r->tag, tag)) {
 559             return true;
 560         }
 561     }
 562     return false;
 563 }
 564
 565 static int64_t blkdebug_getlength(BlockDriverState *bs)
 566 {
 567     return bdrv_getlength(bs->file);
 568 }
 569
 570 static BlockDriver bdrv_blkdebug = {
 571     .format_name        = "blkdebug",
 572     .protocol_name      = "blkdebug",
 573
 574     .instance_size      = sizeof(BDRVBlkdebugState),
 575
 576     .bdrv_file_open     = blkdebug_open,
 577     .bdrv_close         = blkdebug_close,
 578     .bdrv_getlength     = blkdebug_getlength,
 579
 580     .bdrv_aio_readv     = blkdebug_aio_readv,
 581     .bdrv_aio_writev    = blkdebug_aio_writev,
 582
 583     .bdrv_debug_event           = blkdebug_debug_event,
 584     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 585     .bdrv_debug_resume          = blkdebug_debug_resume,
 586     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 587 };
 588
 589 static void bdrv_blkdebug_init(void)
 590 {
 591     bdrv_register(&bdrv_blkdebug);
 592 }
 593
 594 block_init(bdrv_blkdebug_init);