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     int new_state;
  32     QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
  33     QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
  34 } BDRVBlkdebugState;
  35
  36 typedef struct BlkdebugAIOCB {
  37     BlockDriverAIOCB common;
  38     QEMUBH *bh;
  39     int ret;
  40 } BlkdebugAIOCB;
  41
  42 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
  43
  44 static const AIOCBInfo blkdebug_aiocb_info = {
  45     .aiocb_size = sizeof(BlkdebugAIOCB),
  46     .cancel     = blkdebug_aio_cancel,
  47 };
  48
  49 enum {
  50     ACTION_INJECT_ERROR,
  51     ACTION_SET_STATE,
  52 };
  53
  54 typedef struct BlkdebugRule {
  55     BlkDebugEvent event;
  56     int action;
  57     int state;
  58     union {
  59         struct {
  60             int error;
  61             int immediately;
  62             int once;
  63             int64_t sector;
  64         } inject;
  65         struct {
  66             int new_state;
  67         } set_state;
  68     } options;
  69     QLIST_ENTRY(BlkdebugRule) next;
  70     QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
  71 } BlkdebugRule;
  72
  73 static QemuOptsList inject_error_opts = {
  74     .name = "inject-error",
  75     .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
  76     .desc = {
  77         {
  78             .name = "event",
  79             .type = QEMU_OPT_STRING,
  80         },
  81         {
  82             .name = "state",
  83             .type = QEMU_OPT_NUMBER,
  84         },
  85         {
  86             .name = "errno",
  87             .type = QEMU_OPT_NUMBER,
  88         },
  89         {
  90             .name = "sector",
  91             .type = QEMU_OPT_NUMBER,
  92         },
  93         {
  94             .name = "once",
  95             .type = QEMU_OPT_BOOL,
  96         },
  97         {
  98             .name = "immediately",
  99             .type = QEMU_OPT_BOOL,
 100         },
 101         { /* end of list */ }
 102     },
 103 };
 104
 105 static QemuOptsList set_state_opts = {
 106     .name = "set-state",
 107     .head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
 108     .desc = {
 109         {
 110             .name = "event",
 111             .type = QEMU_OPT_STRING,
 112         },
 113         {
 114             .name = "state",
 115             .type = QEMU_OPT_NUMBER,
 116         },
 117         {
 118             .name = "new_state",
 119             .type = QEMU_OPT_NUMBER,
 120         },
 121         { /* end of list */ }
 122     },
 123 };
 124
 125 static QemuOptsList *config_groups[] = {
 126     &inject_error_opts,
 127     &set_state_opts,
 128     NULL
 129 };
 130
 131 static const char *event_names[BLKDBG_EVENT_MAX] = {
 132     [BLKDBG_L1_UPDATE]                      = "l1_update",
 133     [BLKDBG_L1_GROW_ALLOC_TABLE]            = "l1_grow.alloc_table",
 134     [BLKDBG_L1_GROW_WRITE_TABLE]            = "l1_grow.write_table",
 135     [BLKDBG_L1_GROW_ACTIVATE_TABLE]         = "l1_grow.activate_table",
 136
 137     [BLKDBG_L2_LOAD]                        = "l2_load",
 138     [BLKDBG_L2_UPDATE]                      = "l2_update",
 139     [BLKDBG_L2_UPDATE_COMPRESSED]           = "l2_update_compressed",
 140     [BLKDBG_L2_ALLOC_COW_READ]              = "l2_alloc.cow_read",
 141     [BLKDBG_L2_ALLOC_WRITE]                 = "l2_alloc.write",
 142
 143     [BLKDBG_READ_AIO]                       = "read_aio",
 144     [BLKDBG_READ_BACKING_AIO]               = "read_backing_aio",
 145     [BLKDBG_READ_COMPRESSED]                = "read_compressed",
 146
 147     [BLKDBG_WRITE_AIO]                      = "write_aio",
 148     [BLKDBG_WRITE_COMPRESSED]               = "write_compressed",
 149
 150     [BLKDBG_VMSTATE_LOAD]                   = "vmstate_load",
 151     [BLKDBG_VMSTATE_SAVE]                   = "vmstate_save",
 152
 153     [BLKDBG_COW_READ]                       = "cow_read",
 154     [BLKDBG_COW_WRITE]                      = "cow_write",
 155
 156     [BLKDBG_REFTABLE_LOAD]                  = "reftable_load",
 157     [BLKDBG_REFTABLE_GROW]                  = "reftable_grow",
 158
 159     [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
 160     [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
 161     [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
 162     [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
 163     [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
 164     [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
 165     [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
 166     [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
 167     [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
 168
 169     [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
 170     [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
 171     [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 172 };
 173
 174 static int get_event_by_name(const char *name, BlkDebugEvent *event)
 175 {
 176     int i;
 177
 178     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 179         if (!strcmp(event_names[i], name)) {
 180             *event = i;
 181             return 0;
 182         }
 183     }
 184
 185     return -1;
 186 }
 187
 188 struct add_rule_data {
 189     BDRVBlkdebugState *s;
 190     int action;
 191 };
 192
 193 static int add_rule(QemuOpts *opts, void *opaque)
 194 {
 195     struct add_rule_data *d = opaque;
 196     BDRVBlkdebugState *s = d->s;
 197     const char* event_name;
 198     BlkDebugEvent event;
 199     struct BlkdebugRule *rule;
 200
 201     /* Find the right event for the rule */
 202     event_name = qemu_opt_get(opts, "event");
 203     if (!event_name || get_event_by_name(event_name, &event) < 0) {
 204         return -1;
 205     }
 206
 207     /* Set attributes common for all actions */
 208     rule = g_malloc0(sizeof(*rule));
 209     *rule = (struct BlkdebugRule) {
 210         .event  = event,
 211         .action = d->action,
 212         .state  = qemu_opt_get_number(opts, "state", 0),
 213     };
 214
 215     /* Parse action-specific options */
 216     switch (d->action) {
 217     case ACTION_INJECT_ERROR:
 218         rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
 219         rule->options.inject.once  = qemu_opt_get_bool(opts, "once", 0);
 220         rule->options.inject.immediately =
 221             qemu_opt_get_bool(opts, "immediately", 0);
 222         rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
 223         break;
 224
 225     case ACTION_SET_STATE:
 226         rule->options.set_state.new_state =
 227             qemu_opt_get_number(opts, "new_state", 0);
 228         break;
 229     };
 230
 231     /* Add the rule */
 232     QLIST_INSERT_HEAD(&s->rules[event], rule, next);
 233
 234     return 0;
 235 }
 236
 237 static void remove_rule(BlkdebugRule *rule)
 238 {
 239     switch (rule->action) {
 240     case ACTION_INJECT_ERROR:
 241     case ACTION_SET_STATE:
 242         break;
 243     }
 244
 245     QLIST_REMOVE(rule, next);
 246     g_free(rule);
 247 }
 248
 249 static int read_config(BDRVBlkdebugState *s, const char *filename)
 250 {
 251     FILE *f;
 252     int ret;
 253     struct add_rule_data d;
 254
 255     /* Allow usage without config file */
 256     if (!*filename) {
 257         return 0;
 258     }
 259
 260     f = fopen(filename, "r");
 261     if (f == NULL) {
 262         return -errno;
 263     }
 264
 265     ret = qemu_config_parse(f, config_groups, filename);
 266     if (ret < 0) {
 267         goto fail;
 268     }
 269
 270     d.s = s;
 271     d.action = ACTION_INJECT_ERROR;
 272     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 273
 274     d.action = ACTION_SET_STATE;
 275     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 276
 277     ret = 0;
 278 fail:
 279     qemu_opts_reset(&inject_error_opts);
 280     qemu_opts_reset(&set_state_opts);
 281     fclose(f);
 282     return ret;
 283 }
 284
 285 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 286 static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
 287 {
 288     BDRVBlkdebugState *s = bs->opaque;
 289     int ret;
 290     char *config, *c;
 291
 292     /* Parse the blkdebug: prefix */
 293     if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
 294         return -EINVAL;
 295     }
 296     filename += strlen("blkdebug:");
 297
 298     /* Read rules from config file */
 299     c = strchr(filename, ':');
 300     if (c == NULL) {
 301         return -EINVAL;
 302     }
 303
 304     config = g_strdup(filename);
 305     config[c - filename] = '\0';
 306     ret = read_config(s, config);
 307     g_free(config);
 308     if (ret < 0) {
 309         return ret;
 310     }
 311     filename = c + 1;
 312
 313     /* Set initial state */
 314     s->state = 1;
 315
 316     /* Open the backing file */
 317     ret = bdrv_file_open(&bs->file, filename, flags);
 318     if (ret < 0) {
 319         return ret;
 320     }
 321
 322     return 0;
 323 }
 324
 325 static void error_callback_bh(void *opaque)
 326 {
 327     struct BlkdebugAIOCB *acb = opaque;
 328     qemu_bh_delete(acb->bh);
 329     acb->common.cb(acb->common.opaque, acb->ret);
 330     qemu_aio_release(acb);
 331 }
 332
 333 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 334 {
 335     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 336     qemu_aio_release(acb);
 337 }
 338
 339 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 340     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 341 {
 342     BDRVBlkdebugState *s = bs->opaque;
 343     int error = rule->options.inject.error;
 344     struct BlkdebugAIOCB *acb;
 345     QEMUBH *bh;
 346
 347     if (rule->options.inject.once) {
 348         QSIMPLEQ_INIT(&s->active_rules);
 349     }
 350
 351     if (rule->options.inject.immediately) {
 352         return NULL;
 353     }
 354
 355     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 356     acb->ret = -error;
 357
 358     bh = qemu_bh_new(error_callback_bh, acb);
 359     acb->bh = bh;
 360     qemu_bh_schedule(bh);
 361
 362     return &acb->common;
 363 }
 364
 365 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 366     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 367     BlockDriverCompletionFunc *cb, void *opaque)
 368 {
 369     BDRVBlkdebugState *s = bs->opaque;
 370     BlkdebugRule *rule = NULL;
 371
 372     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 373         if (rule->options.inject.sector == -1 ||
 374             (rule->options.inject.sector >= sector_num &&
 375              rule->options.inject.sector < sector_num + nb_sectors)) {
 376             break;
 377         }
 378     }
 379
 380     if (rule && rule->options.inject.error) {
 381         return inject_error(bs, cb, opaque, rule);
 382     }
 383
 384     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 385 }
 386
 387 static BlockDriverAIOCB *blkdebug_aio_writev(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_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 407 }
 408
 409 static void blkdebug_close(BlockDriverState *bs)
 410 {
 411     BDRVBlkdebugState *s = bs->opaque;
 412     BlkdebugRule *rule, *next;
 413     int i;
 414
 415     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 416         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 417             remove_rule(rule);
 418         }
 419     }
 420 }
 421
 422 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 423     bool injected)
 424 {
 425     BDRVBlkdebugState *s = bs->opaque;
 426
 427     /* Only process rules for the current state */
 428     if (rule->state && rule->state != s->state) {
 429         return injected;
 430     }
 431
 432     /* Take the action */
 433     switch (rule->action) {
 434     case ACTION_INJECT_ERROR:
 435         if (!injected) {
 436             QSIMPLEQ_INIT(&s->active_rules);
 437             injected = true;
 438         }
 439         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 440         break;
 441
 442     case ACTION_SET_STATE:
 443         s->new_state = rule->options.set_state.new_state;
 444         break;
 445     }
 446     return injected;
 447 }
 448
 449 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 450 {
 451     BDRVBlkdebugState *s = bs->opaque;
 452     struct BlkdebugRule *rule;
 453     bool injected;
 454
 455     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 456
 457     injected = false;
 458     s->new_state = s->state;
 459     QLIST_FOREACH(rule, &s->rules[event], next) {
 460         injected = process_rule(bs, rule, injected);
 461     }
 462     s->state = s->new_state;
 463 }
 464
 465 static int64_t blkdebug_getlength(BlockDriverState *bs)
 466 {
 467     return bdrv_getlength(bs->file);
 468 }
 469
 470 static BlockDriver bdrv_blkdebug = {
 471     .format_name        = "blkdebug",
 472     .protocol_name      = "blkdebug",
 473
 474     .instance_size      = sizeof(BDRVBlkdebugState),
 475
 476     .bdrv_file_open     = blkdebug_open,
 477     .bdrv_close         = blkdebug_close,
 478     .bdrv_getlength     = blkdebug_getlength,
 479
 480     .bdrv_aio_readv     = blkdebug_aio_readv,
 481     .bdrv_aio_writev    = blkdebug_aio_writev,
 482
 483     .bdrv_debug_event   = blkdebug_debug_event,
 484 };
 485
 486 static void bdrv_blkdebug_init(void)
 487 {
 488     bdrv_register(&bdrv_blkdebug);
 489 }
 490
 491 block_init(bdrv_blkdebug_init);