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     [BLKDBG_FLUSH_TO_OS]                    = "flush_to_os",
 187     [BLKDBG_FLUSH_TO_DISK]                  = "flush_to_disk",
 188 };
 189
 190 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 191 {
 192     int i;
 193
 194     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 195         if (!strcmp(event_names[i], name)) {
 196             *event = i;
 197             return 0;
 198         }
 199     }
 200
 201     return -1;
 202 }
 203
 204 struct add_rule_data {
 205     BDRVBlkdebugState *s;
 206     int action;
 207 };
 208
 209 static int add_rule(QemuOpts *opts, void *opaque)
 210 {
 211     struct add_rule_data *d = opaque;
 212     BDRVBlkdebugState *s = d->s;
 213     const char* event_name;
 214     BlkDebugEvent event;
 215     struct BlkdebugRule *rule;
 216
 217     /* Find the right event for the rule */
 218     event_name = qemu_opt_get(opts, "event");
 219     if (!event_name || get_event_by_name(event_name, &event) < 0) {
 220         return -1;
 221     }
 222
 223     /* Set attributes common for all actions */
 224     rule = g_malloc0(sizeof(*rule));
 225     *rule = (struct BlkdebugRule) {
 226         .event  = event,
 227         .action = d->action,
 228         .state  = qemu_opt_get_number(opts, "state", 0),
 229     };
 230
 231     /* Parse action-specific options */
 232     switch (d->action) {
 233     case ACTION_INJECT_ERROR:
 234         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 235         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 236         rule->options.inject.immediately =
 237             qemu_opt_get_bool(opts, "immediately", 0);
 238         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 239         break;
 240
 241     case ACTION_SET_STATE:
 242         rule->options.set_state.new_state =
 243             qemu_opt_get_number(opts, "new_state", 0);
 244         break;
 245
 246     case ACTION_SUSPEND:
 247         rule->options.suspend.tag =
 248             g_strdup(qemu_opt_get(opts, "tag"));
 249         break;
 250     };
 251
 252     /* Add the rule */
 253     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 254
 255     return 0;
 256 }
 257
 258 static void remove_rule(BlkdebugRule *rule)
 259 {
 260     switch (rule->action) {
 261     case ACTION_INJECT_ERROR:
 262     case ACTION_SET_STATE:
 263         break;
 264     case ACTION_SUSPEND:
 265         g_free(rule->options.suspend.tag);
 266         break;
 267     }
 268
 269     QLIST_REMOVE(rule, next);
 270     g_free(rule);
 271 }
 272
 273 static int read_config(BDRVBlkdebugState *s, const char *filename)
 274 {
 275     FILE *f;
 276     int ret;
 277     struct add_rule_data d;
 278
 279     f = fopen(filename, "r");
 280     if (f == NULL) {
 281         return -errno;
 282     }
 283
 284     ret = qemu_config_parse(f, config_groups, filename);
 285     if (ret < 0) {
 286         goto fail;
 287     }
 288
 289     d.s = s;
 290     d.action = ACTION_INJECT_ERROR;
 291     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 292
 293     d.action = ACTION_SET_STATE;
 294     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 295
 296     ret = 0;
 297 fail:
 298     qemu_opts_reset(&inject_error_opts);
 299     qemu_opts_reset(&set_state_opts);
 300     fclose(f);
 301     return ret;
 302 }
 303
 304 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 305 static void blkdebug_parse_filename(const char *filename, QDict *options,
 306                                     Error **errp)
 307 {
 308     const char *c;
 309
 310     /* Parse the blkdebug: prefix */
 311     if (!strstart(filename, "blkdebug:", &filename)) {
 312         error_setg(errp, "File name string must start with 'blkdebug:'");
 313         return;
 314     }
 315
 316     /* Parse config file path */
 317     c = strchr(filename, ':');
 318     if (c == NULL) {
 319         error_setg(errp, "blkdebug requires both config file and image path");
 320         return;
 321     }
 322
 323     if (c != filename) {
 324         QString *config_path;
 325         config_path = qstring_from_substr(filename, 0, c - filename - 1);
 326         qdict_put(options, "config", config_path);
 327     }
 328
 329     /* TODO Allow multi-level nesting and set file.filename here */
 330     filename = c + 1;
 331     qdict_put(options, "x-image", qstring_from_str(filename));
 332 }
 333
 334 static QemuOptsList runtime_opts = {
 335     .name = "blkdebug",
 336     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 337     .desc = {
 338         {
 339             .name = "config",
 340             .type = QEMU_OPT_STRING,
 341             .help = "Path to the configuration file",
 342         },
 343         {
 344             .name = "x-image",
 345             .type = QEMU_OPT_STRING,
 346             .help = "[internal use only, will be removed]",
 347         },
 348         { /* end of list */ }
 349     },
 350 };
 351
 352 static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags)
 353 {
 354     BDRVBlkdebugState *s = bs->opaque;
 355     QemuOpts *opts;
 356     Error *local_err = NULL;
 357     const char *filename, *config;
 358     int ret;
 359
 360     opts = qemu_opts_create_nofail(&runtime_opts);
 361     qemu_opts_absorb_qdict(opts, options, &local_err);
 362     if (error_is_set(&local_err)) {
 363         qerror_report_err(local_err);
 364         error_free(local_err);
 365         ret = -EINVAL;
 366         goto fail;
 367     }
 368
 369     /* Read rules from config file */
 370     config = qemu_opt_get(opts, "config");
 371     if (config) {
 372         ret = read_config(s, config);
 373         if (ret < 0) {
 374             goto fail;
 375         }
 376     }
 377
 378     /* Set initial state */
 379     s->state = 1;
 380
 381     /* Open the backing file */
 382     filename = qemu_opt_get(opts, "x-image");
 383     if (filename == NULL) {
 384         ret = -EINVAL;
 385         goto fail;
 386     }
 387
 388     ret = bdrv_file_open(&bs->file, filename, NULL, flags);
 389     if (ret < 0) {
 390         goto fail;
 391     }
 392
 393     ret = 0;
 394 fail:
 395     qemu_opts_del(opts);
 396     return ret;
 397 }
 398
 399 static void error_callback_bh(void *opaque)
 400 {
 401     struct BlkdebugAIOCB *acb = opaque;
 402     qemu_bh_delete(acb->bh);
 403     acb->common.cb(acb->common.opaque, acb->ret);
 404     qemu_aio_release(acb);
 405 }
 406
 407 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 408 {
 409     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 410     qemu_aio_release(acb);
 411 }
 412
 413 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 414     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 415 {
 416     BDRVBlkdebugState *s = bs->opaque;
 417     int error = rule->options.inject.error;
 418     struct BlkdebugAIOCB *acb;
 419     QEMUBH *bh;
 420
 421     if (rule->options.inject.once) {
 422         QSIMPLEQ_INIT(&s->active_rules);
 423     }
 424
 425     if (rule->options.inject.immediately) {
 426         return NULL;
 427     }
 428
 429     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 430     acb->ret = -error;
 431
 432     bh = qemu_bh_new(error_callback_bh, acb);
 433     acb->bh = bh;
 434     qemu_bh_schedule(bh);
 435
 436     return &acb->common;
 437 }
 438
 439 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 440     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 441     BlockDriverCompletionFunc *cb, void *opaque)
 442 {
 443     BDRVBlkdebugState *s = bs->opaque;
 444     BlkdebugRule *rule = NULL;
 445
 446     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 447         if (rule->options.inject.sector == -1 ||
 448             (rule->options.inject.sector >= sector_num &&
 449              rule->options.inject.sector < sector_num + nb_sectors)) {
 450             break;
 451         }
 452     }
 453
 454     if (rule && rule->options.inject.error) {
 455         return inject_error(bs, cb, opaque, rule);
 456     }
 457
 458     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 459 }
 460
 461 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 462     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 463     BlockDriverCompletionFunc *cb, void *opaque)
 464 {
 465     BDRVBlkdebugState *s = bs->opaque;
 466     BlkdebugRule *rule = NULL;
 467
 468     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 469         if (rule->options.inject.sector == -1 ||
 470             (rule->options.inject.sector >= sector_num &&
 471              rule->options.inject.sector < sector_num + nb_sectors)) {
 472             break;
 473         }
 474     }
 475
 476     if (rule && rule->options.inject.error) {
 477         return inject_error(bs, cb, opaque, rule);
 478     }
 479
 480     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 481 }
 482
 483
 484 static void blkdebug_close(BlockDriverState *bs)
 485 {
 486     BDRVBlkdebugState *s = bs->opaque;
 487     BlkdebugRule *rule, *next;
 488     int i;
 489
 490     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 491         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 492             remove_rule(rule);
 493         }
 494     }
 495 }
 496
 497 static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
 498 {
 499     BDRVBlkdebugState *s = bs->opaque;
 500     BlkdebugSuspendedReq r;
 501
 502     r = (BlkdebugSuspendedReq) {
 503         .co         = qemu_coroutine_self(),
 504         .tag        = g_strdup(rule->options.suspend.tag),
 505     };
 506
 507     remove_rule(rule);
 508     QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
 509
 510     printf("blkdebug: Suspended request '%s'\n", r.tag);
 511     qemu_coroutine_yield();
 512     printf("blkdebug: Resuming request '%s'\n", r.tag);
 513
 514     QLIST_REMOVE(&r, next);
 515     g_free(r.tag);
 516 }
 517
 518 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 519     bool injected)
 520 {
 521     BDRVBlkdebugState *s = bs->opaque;
 522
 523     /* Only process rules for the current state */
 524     if (rule->state && rule->state != s->state) {
 525         return injected;
 526     }
 527
 528     /* Take the action */
 529     switch (rule->action) {
 530     case ACTION_INJECT_ERROR:
 531         if (!injected) {
 532             QSIMPLEQ_INIT(&s->active_rules);
 533             injected = true;
 534         }
 535         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 536         break;
 537
 538     case ACTION_SET_STATE:
 539         s->new_state = rule->options.set_state.new_state;
 540         break;
 541
 542     case ACTION_SUSPEND:
 543         suspend_request(bs, rule);
 544         break;
 545     }
 546     return injected;
 547 }
 548
 549 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 550 {
 551     BDRVBlkdebugState *s = bs->opaque;
 552     struct BlkdebugRule *rule, *next;
 553     bool injected;
 554
 555     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 556
 557     injected = false;
 558     s->new_state = s->state;
 559     QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
 560         injected = process_rule(bs, rule, injected);
 561     }
 562     s->state = s->new_state;
 563 }
 564
 565 static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
 566                                      const char *tag)
 567 {
 568     BDRVBlkdebugState *s = bs->opaque;
 569     struct BlkdebugRule *rule;
 570     BlkDebugEvent blkdebug_event;
 571
 572     if (get_event_by_name(event, &blkdebug_event) < 0) {
 573         return -ENOENT;
 574     }
 575
 576
 577     rule = g_malloc(sizeof(*rule));
 578     *rule = (struct BlkdebugRule) {
 579         .event  = blkdebug_event,
 580         .action = ACTION_SUSPEND,
 581         .state  = 0,
 582         .options.suspend.tag = g_strdup(tag),
 583     };
 584
 585     QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
 586
 587     return 0;
 588 }
 589
 590 static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
 591 {
 592     BDRVBlkdebugState *s = bs->opaque;
 593     BlkdebugSuspendedReq *r;
 594
 595     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 596         if (!strcmp(r->tag, tag)) {
 597             qemu_coroutine_enter(r->co, NULL);
 598             return 0;
 599         }
 600     }
 601     return -ENOENT;
 602 }
 603
 604
 605 static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
 606 {
 607     BDRVBlkdebugState *s = bs->opaque;
 608     BlkdebugSuspendedReq *r;
 609
 610     QLIST_FOREACH(r, &s->suspended_reqs, next) {
 611         if (!strcmp(r->tag, tag)) {
 612             return true;
 613         }
 614     }
 615     return false;
 616 }
 617
 618 static int64_t blkdebug_getlength(BlockDriverState *bs)
 619 {
 620     return bdrv_getlength(bs->file);
 621 }
 622
 623 static BlockDriver bdrv_blkdebug = {
 624     .format_name            = "blkdebug",
 625     .protocol_name          = "blkdebug",
 626     .instance_size          = sizeof(BDRVBlkdebugState),
 627
 628     .bdrv_parse_filename    = blkdebug_parse_filename,
 629     .bdrv_file_open         = blkdebug_open,
 630     .bdrv_close             = blkdebug_close,
 631     .bdrv_getlength         = blkdebug_getlength,
 632
 633     .bdrv_aio_readv         = blkdebug_aio_readv,
 634     .bdrv_aio_writev        = blkdebug_aio_writev,
 635
 636     .bdrv_debug_event           = blkdebug_debug_event,
 637     .bdrv_debug_breakpoint      = blkdebug_debug_breakpoint,
 638     .bdrv_debug_resume          = blkdebug_debug_resume,
 639     .bdrv_debug_is_suspended    = blkdebug_debug_is_suspended,
 640 };
 641
 642 static void bdrv_blkdebug_init(void)
 643 {
 644     bdrv_register(&bdrv_blkdebug);
 645 }
 646
 647 block_init(bdrv_blkdebug_init);