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 "block_int.h"
  27 #include "module.h"
  28
  29 typedef struct BDRVBlkdebugState {
  30     int state;
  31     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
  32     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  33 } BDRVBlkdebugState;
  34
  35 typedef struct BlkdebugAIOCB {
  36     BlockDriverAIOCB common;
  37     QEMUBH *bh;
  38     int ret;
  39 } BlkdebugAIOCB;
  40
  41 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
  42
  43 static AIOPool blkdebug_aio_pool = {
  44     .aiocb_size = sizeof(BlkdebugAIOCB),
  45     .cancel     = blkdebug_aio_cancel,
  46 };
  47
  48 enum {
  49     ACTION_INJECT_ERROR,
  50     ACTION_SET_STATE,
  51 };
  52
  53 typedef struct BlkdebugRule {
  54     BlkDebugEvent event;
  55     int action;
  56     int state;
  57     union {
  58         struct {
  59             int error;
  60             int immediately;
  61             int once;
  62             int64_t sector;
  63         } inject;
  64         struct {
  65             int new_state;
  66         } set_state;
  67     } options;
  68     QLIST_ENTRY(BlkdebugRule) next;
  69     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
  70 } BlkdebugRule;
  71
  72 static QemuOptsList inject_error_opts = {
  73     .name = "inject-error",
  74     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
  75     .desc = {
  76         {
  77             .name = "event",
  78             .type = QEMU_OPT_STRING,
  79         },
  80         {
  81             .name = "state",
  82             .type = QEMU_OPT_NUMBER,
  83         },
  84         {
  85             .name = "errno",
  86             .type = QEMU_OPT_NUMBER,
  87         },
  88         {
  89             .name = "sector",
  90             .type = QEMU_OPT_NUMBER,
  91         },
  92         {
  93             .name = "once",
  94             .type = QEMU_OPT_BOOL,
  95         },
  96         {
  97             .name = "immediately",
  98             .type = QEMU_OPT_BOOL,
  99         },
 100         { /* end of list */ }
 101     },
 102 };
 103
 104 static QemuOptsList set_state_opts = {
 105     .name = "set-state",
 106     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 107     .desc = {
 108         {
 109             .name = "event",
 110             .type = QEMU_OPT_STRING,
 111         },
 112         {
 113             .name = "state",
 114             .type = QEMU_OPT_NUMBER,
 115         },
 116         {
 117             .name = "new_state",
 118             .type = QEMU_OPT_NUMBER,
 119         },
 120         { /* end of list */ }
 121     },
 122 };
 123
 124 static QemuOptsList *config_groups[] = {
 125     &inject_error_opts,
 126     &set_state_opts,
 127     NULL
 128 };
 129
 130 static const char *event_names[BLKDBG_EVENT_MAX] = {
 131     [BLKDBG_L1_UPDATE]                      = "l1_update",
 132     [BLKDBG_L1_GROW_ALLOC_TABLE]            = "l1_grow.alloc_table",
 133     [BLKDBG_L1_GROW_WRITE_TABLE]            = "l1_grow.write_table",
 134     [BLKDBG_L1_GROW_ACTIVATE_TABLE]         = "l1_grow.activate_table",
 135
 136     [BLKDBG_L2_LOAD]                        = "l2_load",
 137     [BLKDBG_L2_UPDATE]                      = "l2_update",
 138     [BLKDBG_L2_UPDATE_COMPRESSED]           = "l2_update_compressed",
 139     [BLKDBG_L2_ALLOC_COW_READ]              = "l2_alloc.cow_read",
 140     [BLKDBG_L2_ALLOC_WRITE]                 = "l2_alloc.write",
 141
 142     [BLKDBG_READ_AIO]                       = "read_aio",
 143     [BLKDBG_READ_BACKING_AIO]               = "read_backing_aio",
 144     [BLKDBG_READ_COMPRESSED]                = "read_compressed",
 145
 146     [BLKDBG_WRITE_AIO]                      = "write_aio",
 147     [BLKDBG_WRITE_COMPRESSED]               = "write_compressed",
 148
 149     [BLKDBG_VMSTATE_LOAD]                   = "vmstate_load",
 150     [BLKDBG_VMSTATE_SAVE]                   = "vmstate_save",
 151
 152     [BLKDBG_COW_READ]                       = "cow_read",
 153     [BLKDBG_COW_WRITE]                      = "cow_write",
 154
 155     [BLKDBG_REFTABLE_LOAD]                  = "reftable_load",
 156     [BLKDBG_REFTABLE_GROW]                  = "reftable_grow",
 157
 158     [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
 159     [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
 160     [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
 161     [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
 162     [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
 163     [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
 164     [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
 165     [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
 166     [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
 167
 168     [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
 169     [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
 170     [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 171 };
 172
 173 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 174 {
 175     int i;
 176
 177     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 178         if (!strcmp(event_names[i], name)) {
 179             *event = i;
 180             return 0;
 181         }
 182     }
 183
 184     return -1;
 185 }
 186
 187 struct add_rule_data {
 188     BDRVBlkdebugState *s;
 189     int action;
 190 };
 191
 192 static int add_rule(QemuOpts *opts, void *opaque)
 193 {
 194     struct add_rule_data *d = opaque;
 195     BDRVBlkdebugState *s = d->s;
 196     const char* event_name;
 197     BlkDebugEvent event;
 198     struct BlkdebugRule *rule;
 199
 200     /* Find the right event for the rule */
 201     event_name = qemu_opt_get(opts, "event");
 202     if (!event_name || get_event_by_name(event_name, &event) < 0) {
 203         return -1;
 204     }
 205
 206     /* Set attributes common for all actions */
 207     rule = g_malloc0(sizeof(*rule));
 208     *rule = (struct BlkdebugRule) {
 209         .event  = event,
 210         .action = d->action,
 211         .state  = qemu_opt_get_number(opts, "state", 0),
 212     };
 213
 214     /* Parse action-specific options */
 215     switch (d->action) {
 216     case ACTION_INJECT_ERROR:
 217         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 218         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 219         rule->options.inject.immediately =
 220             qemu_opt_get_bool(opts, "immediately", 0);
 221         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 222         break;
 223
 224     case ACTION_SET_STATE:
 225         rule->options.set_state.new_state =
 226             qemu_opt_get_number(opts, "new_state", 0);
 227         break;
 228     };
 229
 230     /* Add the rule */
 231     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 232
 233     return 0;
 234 }
 235
 236 static int read_config(BDRVBlkdebugState *s, const char *filename)
 237 {
 238     FILE *f;
 239     int ret;
 240     struct add_rule_data d;
 241
 242     f = fopen(filename, "r");
 243     if (f == NULL) {
 244         return -errno;
 245     }
 246
 247     ret = qemu_config_parse(f, config_groups, filename);
 248     if (ret < 0) {
 249         goto fail;
 250     }
 251
 252     d.s = s;
 253     d.action = ACTION_INJECT_ERROR;
 254     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 255
 256     d.action = ACTION_SET_STATE;
 257     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 258
 259     ret = 0;
 260 fail:
 261     qemu_opts_reset(&inject_error_opts);
 262     qemu_opts_reset(&set_state_opts);
 263     fclose(f);
 264     return ret;
 265 }
 266
 267 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 268 static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
 269 {
 270     BDRVBlkdebugState *s = bs->opaque;
 271     int ret;
 272     char *config, *c;
 273
 274     /* Parse the blkdebug: prefix */
 275     if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
 276         return -EINVAL;
 277     }
 278     filename += strlen("blkdebug:");
 279
 280     /* Read rules from config file */
 281     c = strchr(filename, ':');
 282     if (c == NULL) {
 283         return -EINVAL;
 284     }
 285
 286     config = g_strdup(filename);
 287     config[c - filename] = '\0';
 288     ret = read_config(s, config);
 289     g_free(config);
 290     if (ret < 0) {
 291         return ret;
 292     }
 293     filename = c + 1;
 294
 295     /* Set initial state */
 296     s->state = 1;
 297
 298     /* Open the backing file */
 299     ret = bdrv_file_open(&bs->file, filename, flags);
 300     if (ret < 0) {
 301         return ret;
 302     }
 303
 304     return 0;
 305 }
 306
 307 static void error_callback_bh(void *opaque)
 308 {
 309     struct BlkdebugAIOCB *acb = opaque;
 310     qemu_bh_delete(acb->bh);
 311     acb->common.cb(acb->common.opaque, acb->ret);
 312     qemu_aio_release(acb);
 313 }
 314
 315 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 316 {
 317     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 318     qemu_aio_release(acb);
 319 }
 320
 321 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 322     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 323 {
 324     BDRVBlkdebugState *s = bs->opaque;
 325     int error = rule->options.inject.error;
 326     struct BlkdebugAIOCB *acb;
 327     QEMUBH *bh;
 328
 329     if (rule->options.inject.once) {
 330         QSIMPLEQ_INIT(&s->active_rules);
 331     }
 332
 333     if (rule->options.inject.immediately) {
 334         return NULL;
 335     }
 336
 337     acb = qemu_aio_get(&blkdebug_aio_pool, bs, cb, opaque);
 338     acb->ret = -error;
 339
 340     bh = qemu_bh_new(error_callback_bh, acb);
 341     acb->bh = bh;
 342     qemu_bh_schedule(bh);
 343
 344     return &acb->common;
 345 }
 346
 347 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 348     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 349     BlockDriverCompletionFunc *cb, void *opaque)
 350 {
 351     BDRVBlkdebugState *s = bs->opaque;
 352     BlkdebugRule *rule = NULL;
 353
 354     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 355         if (rule->options.inject.sector == -1 ||
 356             (rule->options.inject.sector >= sector_num &&
 357              rule->options.inject.sector < sector_num + nb_sectors)) {
 358             break;
 359         }
 360     }
 361
 362     if (rule && rule->options.inject.error) {
 363         return inject_error(bs, cb, opaque, rule);
 364     }
 365
 366     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 367 }
 368
 369 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 370     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 371     BlockDriverCompletionFunc *cb, void *opaque)
 372 {
 373     BDRVBlkdebugState *s = bs->opaque;
 374     BlkdebugRule *rule = NULL;
 375
 376     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 377         if (rule->options.inject.sector == -1 ||
 378             (rule->options.inject.sector >= sector_num &&
 379              rule->options.inject.sector < sector_num + nb_sectors)) {
 380             break;
 381         }
 382     }
 383
 384     if (rule && rule->options.inject.error) {
 385         return inject_error(bs, cb, opaque, rule);
 386     }
 387
 388     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 389 }
 390
 391 static void blkdebug_close(BlockDriverState *bs)
 392 {
 393     BDRVBlkdebugState *s = bs->opaque;
 394     BlkdebugRule *rule, *next;
 395     int i;
 396
 397     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 398         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 399             QLIST_REMOVE(rule, next);
 400             g_free(rule);
 401         }
 402     }
 403 }
 404
 405 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 406     int old_state, bool injected)
 407 {
 408     BDRVBlkdebugState *s = bs->opaque;
 409
 410     /* Only process rules for the current state */
 411     if (rule->state && rule->state != old_state) {
 412         return injected;
 413     }
 414
 415     /* Take the action */
 416     switch (rule->action) {
 417     case ACTION_INJECT_ERROR:
 418         if (!injected) {
 419             QSIMPLEQ_INIT(&s->active_rules);
 420             injected = true;
 421         }
 422         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 423         break;
 424
 425     case ACTION_SET_STATE:
 426         s->state = rule->options.set_state.new_state;
 427         break;
 428     }
 429     return injected;
 430 }
 431
 432 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 433 {
 434     BDRVBlkdebugState *s = bs->opaque;
 435     struct BlkdebugRule *rule;
 436     int old_state = s->state;
 437     bool injected;
 438
 439     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 440
 441     injected = false;
 442     QLIST_FOREACH(rule, &s->rules[event], next) {
 443         injected = process_rule(bs, rule, old_state, injected);
 444     }
 445 }
 446
 447 static int64_t blkdebug_getlength(BlockDriverState *bs)
 448 {
 449     return bdrv_getlength(bs->file);
 450 }
 451
 452 static BlockDriver bdrv_blkdebug = {
 453     .format_name        = "blkdebug",
 454     .protocol_name      = "blkdebug",
 455
 456     .instance_size      = sizeof(BDRVBlkdebugState),
 457
 458     .bdrv_file_open     = blkdebug_open,
 459     .bdrv_close         = blkdebug_close,
 460     .bdrv_getlength     = blkdebug_getlength,
 461
 462     .bdrv_aio_readv     = blkdebug_aio_readv,
 463     .bdrv_aio_writev    = blkdebug_aio_writev,
 464
 465     .bdrv_debug_event   = blkdebug_debug_event,
 466 };
 467
 468 static void bdrv_blkdebug_init(void)
 469 {
 470     bdrv_register(&bdrv_blkdebug);
 471 }
 472
 473 block_init(bdrv_blkdebug_init);