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 int read_config(BDRVBlkdebugState *s, const char *filename)
 238 {
 239     FILE *f;
 240     int ret;
 241     struct add_rule_data d;
 242
 243     f = fopen(filename, "r");
 244     if (f == NULL) {
 245         return -errno;
 246     }
 247
 248     ret = qemu_config_parse(f, config_groups, filename);
 249     if (ret < 0) {
 250         goto fail;
 251     }
 252
 253     d.s = s;
 254     d.action = ACTION_INJECT_ERROR;
 255     qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
 256
 257     d.action = ACTION_SET_STATE;
 258     qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
 259
 260     ret = 0;
 261 fail:
 262     qemu_opts_reset(&inject_error_opts);
 263     qemu_opts_reset(&set_state_opts);
 264     fclose(f);
 265     return ret;
 266 }
 267
 268 /* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
 269 static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
 270 {
 271     BDRVBlkdebugState *s = bs->opaque;
 272     int ret;
 273     char *config, *c;
 274
 275     /* Parse the blkdebug: prefix */
 276     if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
 277         return -EINVAL;
 278     }
 279     filename += strlen("blkdebug:");
 280
 281     /* Read rules from config file */
 282     c = strchr(filename, ':');
 283     if (c == NULL) {
 284         return -EINVAL;
 285     }
 286
 287     config = g_strdup(filename);
 288     config[c - filename] = '\0';
 289     ret = read_config(s, config);
 290     g_free(config);
 291     if (ret < 0) {
 292         return ret;
 293     }
 294     filename = c + 1;
 295
 296     /* Set initial state */
 297     s->state = 1;
 298
 299     /* Open the backing file */
 300     ret = bdrv_file_open(&bs->file, filename, flags);
 301     if (ret < 0) {
 302         return ret;
 303     }
 304
 305     return 0;
 306 }
 307
 308 static void error_callback_bh(void *opaque)
 309 {
 310     struct BlkdebugAIOCB *acb = opaque;
 311     qemu_bh_delete(acb->bh);
 312     acb->common.cb(acb->common.opaque, acb->ret);
 313     qemu_aio_release(acb);
 314 }
 315
 316 static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
 317 {
 318     BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
 319     qemu_aio_release(acb);
 320 }
 321
 322 static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
 323     BlockDriverCompletionFunc *cb, void *opaque, BlkdebugRule *rule)
 324 {
 325     BDRVBlkdebugState *s = bs->opaque;
 326     int error = rule->options.inject.error;
 327     struct BlkdebugAIOCB *acb;
 328     QEMUBH *bh;
 329
 330     if (rule->options.inject.once) {
 331         QSIMPLEQ_INIT(&s->active_rules);
 332     }
 333
 334     if (rule->options.inject.immediately) {
 335         return NULL;
 336     }
 337
 338     acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
 339     acb->ret = -error;
 340
 341     bh = qemu_bh_new(error_callback_bh, acb);
 342     acb->bh = bh;
 343     qemu_bh_schedule(bh);
 344
 345     return &acb->common;
 346 }
 347
 348 static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
 349     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 350     BlockDriverCompletionFunc *cb, void *opaque)
 351 {
 352     BDRVBlkdebugState *s = bs->opaque;
 353     BlkdebugRule *rule = NULL;
 354
 355     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 356         if (rule->options.inject.sector == -1 ||
 357             (rule->options.inject.sector >= sector_num &&
 358              rule->options.inject.sector < sector_num + nb_sectors)) {
 359             break;
 360         }
 361     }
 362
 363     if (rule && rule->options.inject.error) {
 364         return inject_error(bs, cb, opaque, rule);
 365     }
 366
 367     return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 368 }
 369
 370 static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
 371     int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 372     BlockDriverCompletionFunc *cb, void *opaque)
 373 {
 374     BDRVBlkdebugState *s = bs->opaque;
 375     BlkdebugRule *rule = NULL;
 376
 377     QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
 378         if (rule->options.inject.sector == -1 ||
 379             (rule->options.inject.sector >= sector_num &&
 380              rule->options.inject.sector < sector_num + nb_sectors)) {
 381             break;
 382         }
 383     }
 384
 385     if (rule && rule->options.inject.error) {
 386         return inject_error(bs, cb, opaque, rule);
 387     }
 388
 389     return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
 390 }
 391
 392 static void blkdebug_close(BlockDriverState *bs)
 393 {
 394     BDRVBlkdebugState *s = bs->opaque;
 395     BlkdebugRule *rule, *next;
 396     int i;
 397
 398     for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
 399         QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
 400             QLIST_REMOVE(rule, next);
 401             g_free(rule);
 402         }
 403     }
 404 }
 405
 406 static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
 407     bool injected)
 408 {
 409     BDRVBlkdebugState *s = bs->opaque;
 410
 411     /* Only process rules for the current state */
 412     if (rule->state && rule->state != s->state) {
 413         return injected;
 414     }
 415
 416     /* Take the action */
 417     switch (rule->action) {
 418     case ACTION_INJECT_ERROR:
 419         if (!injected) {
 420             QSIMPLEQ_INIT(&s->active_rules);
 421             injected = true;
 422         }
 423         QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
 424         break;
 425
 426     case ACTION_SET_STATE:
 427         s->new_state = rule->options.set_state.new_state;
 428         break;
 429     }
 430     return injected;
 431 }
 432
 433 static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
 434 {
 435     BDRVBlkdebugState *s = bs->opaque;
 436     struct BlkdebugRule *rule;
 437     bool injected;
 438
 439     assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
 440
 441     injected = false;
 442     s->new_state = s->state;
 443     QLIST_FOREACH(rule, &s->rules[event], next) {
 444         injected = process_rule(bs, rule, injected);
 445     }
 446     s->state = s->new_state;
 447 }
 448
 449 static int64_t blkdebug_getlength(BlockDriverState *bs)
 450 {
 451     return bdrv_getlength(bs->file);
 452 }
 453
 454 static BlockDriver bdrv_blkdebug = {
 455     .format_name        = "blkdebug",
 456     .protocol_name      = "blkdebug",
 457
 458     .instance_size      = sizeof(BDRVBlkdebugState),
 459
 460     .bdrv_file_open     = blkdebug_open,
 461     .bdrv_close         = blkdebug_close,
 462     .bdrv_getlength     = blkdebug_getlength,
 463
 464     .bdrv_aio_readv     = blkdebug_aio_readv,
 465     .bdrv_aio_writev    = blkdebug_aio_writev,
 466
 467     .bdrv_debug_event   = blkdebug_debug_event,
 468 };
 469
 470 static void bdrv_blkdebug_init(void)
 471 {
 472     bdrv_register(&bdrv_blkdebug);
 473 }
 474
 475 block_init(bdrv_blkdebug_init);